Trehalose is a disaccharide present in a variety of anhydrobiotic organisms which have the abilit... more Trehalose is a disaccharide present in a variety of anhydrobiotic organisms which have the ability to promptly resume their metabolism after addition of water. It has been successfully used as a nontoxic cryoprotectant of enzymes, membranes, vaccines, animal and plant cells and organs for surgical transplants. It has been predicted that trehalose can also be used as an ingredient for dried and processed food. Therefore, the recent biotechnological applications of trehalose have imposed the standardization of methods for its production, as well as for its specific quantification.
Background: The purposes of this study were to determine the 1year functional outcome after first... more Background: The purposes of this study were to determine the 1year functional outcome after first-ever ischemic stroke and to identify the baseline predictors of post-stroke dependency. Patients and methods: We prospectively and consecutively collected data on 300 patients with first-ever acute ischemic stroke admitted to two main neurological institutions for cerebrovascular diseases in Belgrade, Serbia. The predictive value of different variables in 1-year functional dependence was assessed by univariate Cox proportional hazard regression model. Results: Data on functional outcome 1 year after stroke were available for 184 patients (109 died, 7 patients were lost to follow up). Among survivors 100 (54.3%) patients were functionally dependent at the end of the first year after stroke. The univariate predictive model revealed that National Institutes of Health Stroke Scale (NIHSS) score ≥11 (p = 0.019), modified Rankin scale (mRS) ≥ 3 (p = 0.001), Barthel index (BI) ≤ 40 (p = 0.001), diabetes mellitus (p = 0.034), glucose ≥ 7.3 mmol/L on admission (p = 0.035) and nursing-home residence (p = 0.019) were significant unfavorable predictors of dependence, while early physical therapy (p = 0.035) was significant favorable prognostic factor for 1-year functional outcome in our first-ever ischemic stroke patients. In the final multivariate analysis only diabetes mellitus (p = 0.020) and BI ≤ 40 (p = 0.002) remained significant independent predictors of 1-year functional dependency in our cohort. Conclusions: The findings support the need for optimal control of hyperglycemia, especially in patients with diabetes, and emphasize the importance of early implementation of physical therapy, in order to improve initial dependency and long-term functional outcome after an ischemic stroke.
Temporal lobe epilepsy (TLE) is the most common variety of focal epilepsy among adults. The neuro... more Temporal lobe epilepsy (TLE) is the most common variety of focal epilepsy among adults. The neuroinflammatory mechanisms of epilepsies may be involved in the genesis of seizures and refractory epilepsies, particularly in the case of progressive syndromes such as TLE associated with mesial hippocampal sclerosis (TLE-HS). The goal of the present study is investigate the genetic profile of susceptibility of individuals with TLE-HS by analyzing the possible association of TLE-HS with human leukocyte antigen (HLA) DRB1, DQA1 and DQB1 alleles. Methods: Peripheral blood samples were collected from 42 individuals with pharmacoresistant TLE-HS and 89 healthy controls. The typing of the HLA class II alleles from DRB1, DQB1, and DQA1 loci were analyzed using sequence-specific primer-polymerase chain reaction (SSP-PCR) and identified through sequencing. Statistical analysis of relative allele frequencies was performed using an Excel spreadsheet; p-value, relative risk (RR), and odds ratio (OR) were calculated using the software Epi Info 6.0. p-values <0.05 following Bonferroni's method correction were considered statistically significant. Results: HLA-DRB1*13:02 was the only allele with a statistically significant difference (p = 0.01) in frequency between patients and controls. However, the significance was lost following Bonferroni's method correction (p = 0.44). The remainder of the alleles in the HLA-DRB1, HLA-DQB1 and HLA-DQA1 regions did not exhibit any significant association. Conclusion: The allele HLA DRB1*13:02 has exhibited a tendency to behave as a susceptibility factor for TLE-HS.
Background/Aims: Our aim was to investigate a geographical cluster of Huntington's disease (H... more Background/Aims: Our aim was to investigate a geographical cluster of Huntington's disease (HD) in Ervalia, a Brazilian town of Minas Gerais state (MG). Therefore, we calculated the minimum prevalence of HD in Ervalia, known to have many HD affected families. We also determined the genetic profile of the polymorphic CAG region of the HTT gene in 32 subjects of these affected families. Methods: A descriptive cross-sectional study was performed, starting in January 2011 until June 2013. Individuals who participated in the survey were all from Ervalia town, MG. Results: The minimum prevalence rate found was 7.2/10,000 people, higher than the worldwide prevalence. Conclusion: The minimum prevalence of HD in Ervalia was at least 10.3- to 14.4-fold greater than that of the world population, although it does not represent the overall prevalence of the disease in Brazil. Certainly an expanded survey in the country will lead to a lower prevalence estimate than Ervalia's.
The objective of this study was to investigate the association between the HLA alleles at the DQA... more The objective of this study was to investigate the association between the HLA alleles at the DQA1, DQB1 and DRB1 loci, the CIITA genetic polymorphisms -168A/G and +1614G/C, and susceptibility to multiple sclerosis (MS) in a sample from Rio de Janeiro State, Brazil. Furthermore, we wished to determine whether any of these associations might be more significant in women compared with men. DNA samples from 52 relapsing-remitting MS (RRMS) patients and 126 healthy controls matched for sex and age were analyzed. We identified a significant HLA-DRB1*15:01-MS association that was female-specific (Odds Ratio (OR) = 4.78; p = 0.001). Furthermore, we observed that the +1614G/C mutation in combination with the HLA-DRB1*15:01 allele increased susceptibility to MS in females (OR = 4.55; p = 0.01). Together, these findings highlight the polygenic nature of MS.
Trehalase is the enzyme which hydrolyzes the disaccharide trehalose into two-D-glucose molecules.... more Trehalase is the enzyme which hydrolyzes the disaccharide trehalose into two-D-glucose molecules. In this article, we present the immobilization of trehalase on aminopropyl glass particles. The enzyme was extracted from Escherichia coli Mph2, a strain harboring the pTRE11 plasmid, which contains the trehalase gene. The partially purified enzyme had a specific activity of 356 U/mg and could be used for quantifying trehalose in the presence of sucrose, maltose, lactose, starch, and glycogen. Partially purified trehalase was immobilized by covalent coupling with retention of its catalytic activity. The support chosen for the majority of the experiments reported was aminopropyl glass, although spherisorb-5NH 2 and chitin were also tested. The immobilized enzyme was assayed continuously for 40 h, at pH 6.0 and 30°C, and no release of enzyme molecules was detected during this procedure. The best condition found for storing the enzyme–support complex was at 4°C in the presence of 25 mM sodium maleate, containing 7 mM-mer-captoethanol, 1 mM ethylenediaminetetraacetic acid (EDTA), and 50% glycerol. The enzyme under these conditions was stable, retaining approximately 100% of its initial activity for at least 28 days. The immobilized enzyme can be employed to detect trehalose molecules in micromolar concentration. The optimum pH value found was 4.5 and the K m app. 4.9 × 10 −3 M trehalose at pH 4.6 and 30°C, with V max of 5.88 µmol glucose min. −1 , as calculated by a Lineweaver–Burk plot.
We studied the allelic profile of CAG and CCG repeats in 61 Brazilian individuals in 21 independe... more We studied the allelic profile of CAG and CCG repeats in 61 Brazilian individuals in 21 independent families affected by Huntington's disease (HD). Thirteen individuals had two normal alleles for HD, two had one mutable normal allele and no HD phenotype, and forty-six patients carried at least one expanded CAG repeat allele. Forty-five of these individuals had one expanded allele and one individual had one mutable normal allele (27 CAG repeats) and one expanded allele (48 CAG repeats). Eleven of these forty-five subjects had a mutant allele with reduced penetrance, and thirty-four patients had a mutant allele with complete penetrance. Inter-and intragenerational investigations of CAG repeats were also performed. We found a negative correlation between the number of CAG repeats and the age of disease onset (r ¼ À0.84; Po0.001) and no correlation between the number of CCG repeats and the age of disease onset (r ¼ 0.06). We found 40 different haplotypes and the analysis showed that (CCG) 10 was linked to a CAG normal allele in 19 haplotypes and to expanded alleles in two haplotypes. We found that (CCG) 7 was linked to expanded CAG repeats in 40 haplotypes (95.24%) and (CCG) 10 was linked to expanded CAG repeats in only two haplotypes (4.76%). Therefore, (CCG) 7 was the most common allele in HD chromosomes in this Brazilian sample. It was also observed that there was a significant association of (CCG) 7 with the expanded CAG alleles (v 2 ¼ 6.97, P ¼ 0.0084). Worldwide, the most common CCG alleles have 7 or 10 repeats. In Western Europe, (CCG) 7 is the most frequent allele, similarly to our findings.
Huntington's disease (HD) is a rare progressive and fatal neurogenetic degenerative disease, char... more Huntington's disease (HD) is a rare progressive and fatal neurogenetic degenerative disease, characterized by movement and personality disorders and by progressive dementia. Its prevalence varies by ethnic origin and different genetic profiles predisposing individuals to HD in each population. The prevalence of HD is 5-10 per 100,000 individuals in Caucasian populations of North America and Western Europe. It is an autosomal dominant disease associated with the expansion of CAG-type repetitive DNA sequences in the HTT gene. and the USA, with a focus on genetic profiles and intergenerational expansions or contractions of expanded alleles responsible for causing HD. We discuss the genetic characteristics of HD in different
Objective: To describe familial forms of demyelinating diseases from an MS referral center in Río... more Objective: To describe familial forms of demyelinating diseases from an MS referral center in Río de Janeiro State, Brazil. Methods: A descriptive, cross-sectional study was done to identify familial IIDD cases in Hospital da Lagoa, a public hospital where 75% of patients with IIDD who live in Rio de Janeiro state, located in the Southeast region of Brazil, are referred. The diagnoses of all consecutive patients followed in 2011 were reviewed to apply new diagnostic criteria (Wingerchuk et al., 2008). The diagnosis of IIDD was confirmed based on clinical history, neurological examination, MRI of the skull and spinal cord, CSF analysis and investigation of IgG NMO antibodies. The cases that had at least one other relative with IIDD were selected for the study. Results: Familial forms were found only in the multiple sclerosis (MS) and neuromyelitis optica syndrome (NMOSD) categories. 23 MS families were identified, 60.86% with first degree kinship. It has a Caucasian preponderance, 90% of whom were white. The frequency of early onset was 15% and 20% of the MSf cases have progressive primary course. Conclusion: The frequency of familial cases of IIDD was 6.12% among MS patients and 2.8% in NMO spectrum syndromes.
Purpose: Temporal lobe epilepsy (TLE) is the most common variety of focal epilepsy among adults. ... more Purpose: Temporal lobe epilepsy (TLE) is the most common variety of focal epilepsy among adults. The neuroinflammatory mechanisms of epilepsies may be involved in the genesis of seizures and refractory epilepsies, particularly in the case of progressive syndromes such as TLE associated with mesial hippocampal sclerosis (TLE-HS). The goal of the present study is investigate the genetic profile of susceptibility of individuals with TLE-HS by analyzing the possible association of TLE-HS with human leukocyte antigen (HLA) DRB1, DQA1 and DQB1 alleles. Methods: Peripheral blood samples were collected from 42 individuals with pharmacoresistant TLE-HS and 89 healthy controls. The typing of the HLA class II alleles from DRB1, DQB1, and DQA1 loci were analyzed using sequence-specific primer-polymerase chain reaction (SSP-PCR) and identified through sequencing. Statistical analysis of relative allele frequencies was performed using an Excel spreadsheet; p-value, relative risk (RR), and odds ratio (OR) were calculated using the software Epi Info 6.0. p-values <0.05 following Bonferroni's method correction were considered statistically significant. Results: HLA-DRB1*13:02 was the only allele with a statistically significant difference (p = 0.01) in frequency between patients and controls. However, the significance was lost following Bonferroni's method correction (p = 0.44). The remainder of the alleles in the HLA-DRB1, HLA-DQB1 and HLA-DQA1 regions did not exhibit any significant association. Conclusion: The allele HLA DRB1*13:02 has exhibited a tendency to behave as a susceptibility factor for TLE-HS.
Background/Aims: Our aim was to investigate a geographical cluster of Huntington's disease (HD) i... more Background/Aims: Our aim was to investigate a geographical cluster of Huntington's disease (HD) in Ervalia, a Brazilian town of Minas Gerais state (MG). Therefore, we calculated the minimum prevalence of HD in Ervalia, known to have many HD affected families. We also determined the genetic profile of the polymorphic CAG region of the HTT gene in 32 subjects of these affected families. Methods: A descriptive cross-sectional study was performed, starting in January 2011 until June 2013. Individuals who participated in the survey were all from Ervalia town, MG. Results: The minimum prevalence rate found was 7.2/10,000 people, higher than the worldwide prevalence. Conclusion: The minimum prevalence of HD in Ervalia was at least 10.3-to 14.4-fold greater than that of the world population, although it does not represent the overall prevalence of the disease in Brazil. Certainly an expanded survey in the country will lead to a lower prevalence estimate than Ervalia's.
The major clinical features of monosomy 1p36 deletion are developmental delay and hypotonia assoc... more The major clinical features of monosomy 1p36 deletion are developmental delay and hypotonia associated with short stature and craniofacial dysmorphisms. The objective of this study was to review the cases of 1p36 deletion that was reported between 1999 and 2014, in order to identify a possible correlation between the size of the 1p36-deleted segment and the clinical phenotype of the disease. Scientific articles published in the (National Center for Biotechnology Information; NCBI http://www.ncbi.nlm. nih.gov/pubmed) and Scientific Electronic Library Online (www.scielo.com. br) databases were searched using key word combinations, such as " 1p36 deletion " , " monosomy 1p36 deletion " , and " 1p36 deletion syndrome ". Articles in English or Spanish reporting the correlation between deletion sizes and the respective clinical phenotypes were retrieved, while letters, reviews, guidelines, and studies with mouse models were excluded. Among the 746 retrieved articles, only 17 (12 case reports and 5 series of cases), comprising
Trehalase is the enzyme which hydrolyzes the disaccharide trehalose into two-D-glucose molecules.... more Trehalase is the enzyme which hydrolyzes the disaccharide trehalose into two-D-glucose molecules. In this article, we present the immobilization of trehalase on aminopropyl glass particles. The enzyme was extracted from Escherichia coli Mph2, a strain harboring the pTRE11 plasmid, which contains the trehalase gene. The partially purified enzyme had a specific activity of 356 U/mg and could be used for quantifying trehalose in the presence of sucrose, maltose, lactose, starch, and glycogen. Partially purified trehalase was immobilized by covalent coupling with retention of its catalytic activity. The support chosen for the majority of the experiments reported was aminopropyl glass, although spherisorb-5NH 2 and chitin were also tested. The immobilized enzyme was assayed continuously for 40 h, at pH 6.0 and 30°C, and no release of enzyme molecules was detected during this procedure. The best condition found for storing the enzyme–support complex was at 4°C in the presence of 25 mM sodium maleate, containing 7 mM-mer-captoethanol, 1 mM ethylenediaminetetraacetic acid (EDTA), and 50% glycerol. The enzyme under these conditions was stable, retaining approximately 100% of its initial activity for at least 28 days. The immobilized enzyme can be employed to detect trehalose molecules in micromolar concentration. The optimum pH value found was 4.5 and the K m app. 4.9 × 10 −3 M trehalose at pH 4.6 and 30°C, with V max of 5.88 µmol glucose min. −1 , as calculated by a Lineweaver–Burk plot.
Brazil, §Graduate Program in Human Movement Science—Universidade Castelo Branco, Rio de Janeiro, ... more Brazil, §Graduate Program in Human Movement Science—Universidade Castelo Branco, Rio de Janeiro, RJ, Brazil, and }Institute of Genetics and Biochemistry—Universidade Federal de Uberlâ ndia, Uberlâ ndia, MG, Brazil This article presents our experience on teaching biochemical sciences through an innovative approach that integrates concepts of molecular cell biology and protein chemistry. This original laboratory exercise is based on the preparation of an affinity chromatography column containing F-actin molecules immobilized on chitin particles for purifying skeletal myosin II. It favors the active learning of protein extraction and purification, the learning of concepts such as muscle contraction, cytoskeleton structure, and its importance for the living cell. This laboratory exercise also promotes learning biotechnological applications of chitin and the applications of protein immobilization in different industrial fields. Furthermore , the activities target the development of laboratorial abilities, problem-solving skills, and the ability to write a scientific report, following the model of a scientific article. The trials are mainly proposed for either an undergraduate project for advanced students in the life sciences or a postgraduate practical training course. In both the cases, the students must have had biochemistry as part of their regular curriculum. Alternatively, the affinity chromatography method can fit in any regular biochemistry course if active chitin, F-actin, and a myosin II extract are provided. It is very important to mention that this laboratory exercise can be used even in places where a facility such as ultracentrifugation is lacking. For that, the steps of actin purification are skipped, and actin is commercially obtained. Therefore, it is an adequate approach for the active learning of biochemical and molecular cell biology principles and techniques even in poor countries.
The aim of this article was to conduct a retrospective observational study on reported deaths due... more The aim of this article was to conduct a retrospective observational study on reported deaths due to Huntington's disease (HD) in Brazil in the past 25 years (from 1984 to 2008). Data were obtained from the Brazilian Mortality Information System (SIM/ DATASUS), the official system of Brazilian Mortality Database. The data obtained included information regarding the gender of the deceased and the number of death notifications, which we stratified by demographic regions and states. HD mortality per 100,000 was calculated and plotted in a graph. Linear regression was calculated using ordinary least square technique. We observed that the mortality due to HD recorded by SIM/DATASUS from 1984 to 2008 had increased at much higher rates than the population in the same period. Also, some Brazilian regions still show very low rates of HD mortality compared to the national average of deaths due to HD. These findings suggest that
Huntington&amp;amp;#39;s disease (HD) is a rare progressive and fatal neurogenetic degenerati... more Huntington&amp;amp;#39;s disease (HD) is a rare progressive and fatal neurogenetic degenerative disease, characterized by movement and personality disorders and by progressive dementia. Its prevalence varies by ethnic origin and different genetic profiles predisposing individuals to HD in each population. The prevalence of HD is 5-10 per 100,000 individuals in Caucasian populations of North America and Western Europe. It is an autosomal dominant disease associated with the expansion of CAG-type repetitive DNA sequences in the HTT gene. This gene, located on the short arm of chromosome 4, encodes the protein huntingtin. In this study, we reviewed 17 articles about HD that report data from 2400 affected individuals from various countries around the world, including Venezuela, China, Croatia, Turkey, Germany, Italy, Brazil, Spain, Taiwan, India, the Netherlands, Russia, and the USA, with a focus on genetic profiles and intergenerational expansions or contractions of expanded alleles responsible for causing HD. We discuss the genetic characteristics of HD in different populations and any atypical cases reported in these studies.
Trehalose is a disaccharide present in a variety of anhydrobiotic organisms which have the abilit... more Trehalose is a disaccharide present in a variety of anhydrobiotic organisms which have the ability to promptly resume their metabolism after addition of water. It has been successfully used as a nontoxic cryoprotectant of enzymes, membranes, vaccines, animal and plant cells and organs for surgical transplants. It has been predicted that trehalose can also be used as an ingredient for dried and processed food. Therefore, the recent biotechnological applications of trehalose have imposed the standardization of methods for its production, as well as for its specific quantification. Biochemistry and biotechnology were born out of studies with yeast cells. In fact biotechnology preceded the basic science. Early Egyptians already prepared their dough, a simple mixture of flour and water and kept it warm until bubbles began to form. They also delighted in drinking the fermented fruit juices accepting them as a gift from the Gods. Throughout the first half of the 19th century those few scientists who had grasped the truth about yeast had difficulties in imposing their views: fermentation was considered to be a purely chemical reaction in which life was not involved. Only when Pasteur in 1850 turned his attention to fermentation and brewing was it shown that yeast cells were capable of transforming sugar in alcohol. Biochemistry was born soon after, when Edward Buchner in 1896, ground yeast cells with sand and pressed them to obtain an extract for pharmaceutical purposes. In order to preserve it he added sugar. To his surprise, even though the yeast integrity had been destroyed, the fluid was still able to ferment. The enzymes had remained active. The biochemical process involved was identified for both fermentation and raising of dough. Yeast are racing with bacteria for the lead position in biotechnology. They share with animal cells many of the molecules and processes that are subject of intensive study in molecular biology. Moreover, unlike bacterial cells, which must be broken to retrieve a produced heterologous protein, yeast cells are able to secrete the product beyond their cell wall. Furthermore, there is another advantage to the use of yeast cells in biotechnology, it is a psychological advantage. While people tend to associate bacteria with diseases, yeast has been associated, over millennia, with the good things of life, i.e., bread and wine.
Trehalose is a disaccharide present in a variety of anhydrobiotic organisms which have the abilit... more Trehalose is a disaccharide present in a variety of anhydrobiotic organisms which have the ability to promptly resume their metabolism after addition of water. It has been successfully used as a nontoxic cryoprotectant of enzymes, membranes, vaccines, animal and plant cells and organs for surgical transplants. It has been predicted that trehalose can also be used as an ingredient for dried and processed food. Therefore, the recent biotechnological applications of trehalose have imposed the standardization of methods for its production, as well as for its specific quantification.
Background: The purposes of this study were to determine the 1year functional outcome after first... more Background: The purposes of this study were to determine the 1year functional outcome after first-ever ischemic stroke and to identify the baseline predictors of post-stroke dependency. Patients and methods: We prospectively and consecutively collected data on 300 patients with first-ever acute ischemic stroke admitted to two main neurological institutions for cerebrovascular diseases in Belgrade, Serbia. The predictive value of different variables in 1-year functional dependence was assessed by univariate Cox proportional hazard regression model. Results: Data on functional outcome 1 year after stroke were available for 184 patients (109 died, 7 patients were lost to follow up). Among survivors 100 (54.3%) patients were functionally dependent at the end of the first year after stroke. The univariate predictive model revealed that National Institutes of Health Stroke Scale (NIHSS) score ≥11 (p = 0.019), modified Rankin scale (mRS) ≥ 3 (p = 0.001), Barthel index (BI) ≤ 40 (p = 0.001), diabetes mellitus (p = 0.034), glucose ≥ 7.3 mmol/L on admission (p = 0.035) and nursing-home residence (p = 0.019) were significant unfavorable predictors of dependence, while early physical therapy (p = 0.035) was significant favorable prognostic factor for 1-year functional outcome in our first-ever ischemic stroke patients. In the final multivariate analysis only diabetes mellitus (p = 0.020) and BI ≤ 40 (p = 0.002) remained significant independent predictors of 1-year functional dependency in our cohort. Conclusions: The findings support the need for optimal control of hyperglycemia, especially in patients with diabetes, and emphasize the importance of early implementation of physical therapy, in order to improve initial dependency and long-term functional outcome after an ischemic stroke.
Temporal lobe epilepsy (TLE) is the most common variety of focal epilepsy among adults. The neuro... more Temporal lobe epilepsy (TLE) is the most common variety of focal epilepsy among adults. The neuroinflammatory mechanisms of epilepsies may be involved in the genesis of seizures and refractory epilepsies, particularly in the case of progressive syndromes such as TLE associated with mesial hippocampal sclerosis (TLE-HS). The goal of the present study is investigate the genetic profile of susceptibility of individuals with TLE-HS by analyzing the possible association of TLE-HS with human leukocyte antigen (HLA) DRB1, DQA1 and DQB1 alleles. Methods: Peripheral blood samples were collected from 42 individuals with pharmacoresistant TLE-HS and 89 healthy controls. The typing of the HLA class II alleles from DRB1, DQB1, and DQA1 loci were analyzed using sequence-specific primer-polymerase chain reaction (SSP-PCR) and identified through sequencing. Statistical analysis of relative allele frequencies was performed using an Excel spreadsheet; p-value, relative risk (RR), and odds ratio (OR) were calculated using the software Epi Info 6.0. p-values <0.05 following Bonferroni's method correction were considered statistically significant. Results: HLA-DRB1*13:02 was the only allele with a statistically significant difference (p = 0.01) in frequency between patients and controls. However, the significance was lost following Bonferroni's method correction (p = 0.44). The remainder of the alleles in the HLA-DRB1, HLA-DQB1 and HLA-DQA1 regions did not exhibit any significant association. Conclusion: The allele HLA DRB1*13:02 has exhibited a tendency to behave as a susceptibility factor for TLE-HS.
Background/Aims: Our aim was to investigate a geographical cluster of Huntington's disease (H... more Background/Aims: Our aim was to investigate a geographical cluster of Huntington's disease (HD) in Ervalia, a Brazilian town of Minas Gerais state (MG). Therefore, we calculated the minimum prevalence of HD in Ervalia, known to have many HD affected families. We also determined the genetic profile of the polymorphic CAG region of the HTT gene in 32 subjects of these affected families. Methods: A descriptive cross-sectional study was performed, starting in January 2011 until June 2013. Individuals who participated in the survey were all from Ervalia town, MG. Results: The minimum prevalence rate found was 7.2/10,000 people, higher than the worldwide prevalence. Conclusion: The minimum prevalence of HD in Ervalia was at least 10.3- to 14.4-fold greater than that of the world population, although it does not represent the overall prevalence of the disease in Brazil. Certainly an expanded survey in the country will lead to a lower prevalence estimate than Ervalia's.
The objective of this study was to investigate the association between the HLA alleles at the DQA... more The objective of this study was to investigate the association between the HLA alleles at the DQA1, DQB1 and DRB1 loci, the CIITA genetic polymorphisms -168A/G and +1614G/C, and susceptibility to multiple sclerosis (MS) in a sample from Rio de Janeiro State, Brazil. Furthermore, we wished to determine whether any of these associations might be more significant in women compared with men. DNA samples from 52 relapsing-remitting MS (RRMS) patients and 126 healthy controls matched for sex and age were analyzed. We identified a significant HLA-DRB1*15:01-MS association that was female-specific (Odds Ratio (OR) = 4.78; p = 0.001). Furthermore, we observed that the +1614G/C mutation in combination with the HLA-DRB1*15:01 allele increased susceptibility to MS in females (OR = 4.55; p = 0.01). Together, these findings highlight the polygenic nature of MS.
Trehalase is the enzyme which hydrolyzes the disaccharide trehalose into two-D-glucose molecules.... more Trehalase is the enzyme which hydrolyzes the disaccharide trehalose into two-D-glucose molecules. In this article, we present the immobilization of trehalase on aminopropyl glass particles. The enzyme was extracted from Escherichia coli Mph2, a strain harboring the pTRE11 plasmid, which contains the trehalase gene. The partially purified enzyme had a specific activity of 356 U/mg and could be used for quantifying trehalose in the presence of sucrose, maltose, lactose, starch, and glycogen. Partially purified trehalase was immobilized by covalent coupling with retention of its catalytic activity. The support chosen for the majority of the experiments reported was aminopropyl glass, although spherisorb-5NH 2 and chitin were also tested. The immobilized enzyme was assayed continuously for 40 h, at pH 6.0 and 30°C, and no release of enzyme molecules was detected during this procedure. The best condition found for storing the enzyme–support complex was at 4°C in the presence of 25 mM sodium maleate, containing 7 mM-mer-captoethanol, 1 mM ethylenediaminetetraacetic acid (EDTA), and 50% glycerol. The enzyme under these conditions was stable, retaining approximately 100% of its initial activity for at least 28 days. The immobilized enzyme can be employed to detect trehalose molecules in micromolar concentration. The optimum pH value found was 4.5 and the K m app. 4.9 × 10 −3 M trehalose at pH 4.6 and 30°C, with V max of 5.88 µmol glucose min. −1 , as calculated by a Lineweaver–Burk plot.
We studied the allelic profile of CAG and CCG repeats in 61 Brazilian individuals in 21 independe... more We studied the allelic profile of CAG and CCG repeats in 61 Brazilian individuals in 21 independent families affected by Huntington's disease (HD). Thirteen individuals had two normal alleles for HD, two had one mutable normal allele and no HD phenotype, and forty-six patients carried at least one expanded CAG repeat allele. Forty-five of these individuals had one expanded allele and one individual had one mutable normal allele (27 CAG repeats) and one expanded allele (48 CAG repeats). Eleven of these forty-five subjects had a mutant allele with reduced penetrance, and thirty-four patients had a mutant allele with complete penetrance. Inter-and intragenerational investigations of CAG repeats were also performed. We found a negative correlation between the number of CAG repeats and the age of disease onset (r ¼ À0.84; Po0.001) and no correlation between the number of CCG repeats and the age of disease onset (r ¼ 0.06). We found 40 different haplotypes and the analysis showed that (CCG) 10 was linked to a CAG normal allele in 19 haplotypes and to expanded alleles in two haplotypes. We found that (CCG) 7 was linked to expanded CAG repeats in 40 haplotypes (95.24%) and (CCG) 10 was linked to expanded CAG repeats in only two haplotypes (4.76%). Therefore, (CCG) 7 was the most common allele in HD chromosomes in this Brazilian sample. It was also observed that there was a significant association of (CCG) 7 with the expanded CAG alleles (v 2 ¼ 6.97, P ¼ 0.0084). Worldwide, the most common CCG alleles have 7 or 10 repeats. In Western Europe, (CCG) 7 is the most frequent allele, similarly to our findings.
Huntington's disease (HD) is a rare progressive and fatal neurogenetic degenerative disease, char... more Huntington's disease (HD) is a rare progressive and fatal neurogenetic degenerative disease, characterized by movement and personality disorders and by progressive dementia. Its prevalence varies by ethnic origin and different genetic profiles predisposing individuals to HD in each population. The prevalence of HD is 5-10 per 100,000 individuals in Caucasian populations of North America and Western Europe. It is an autosomal dominant disease associated with the expansion of CAG-type repetitive DNA sequences in the HTT gene. and the USA, with a focus on genetic profiles and intergenerational expansions or contractions of expanded alleles responsible for causing HD. We discuss the genetic characteristics of HD in different
Objective: To describe familial forms of demyelinating diseases from an MS referral center in Río... more Objective: To describe familial forms of demyelinating diseases from an MS referral center in Río de Janeiro State, Brazil. Methods: A descriptive, cross-sectional study was done to identify familial IIDD cases in Hospital da Lagoa, a public hospital where 75% of patients with IIDD who live in Rio de Janeiro state, located in the Southeast region of Brazil, are referred. The diagnoses of all consecutive patients followed in 2011 were reviewed to apply new diagnostic criteria (Wingerchuk et al., 2008). The diagnosis of IIDD was confirmed based on clinical history, neurological examination, MRI of the skull and spinal cord, CSF analysis and investigation of IgG NMO antibodies. The cases that had at least one other relative with IIDD were selected for the study. Results: Familial forms were found only in the multiple sclerosis (MS) and neuromyelitis optica syndrome (NMOSD) categories. 23 MS families were identified, 60.86% with first degree kinship. It has a Caucasian preponderance, 90% of whom were white. The frequency of early onset was 15% and 20% of the MSf cases have progressive primary course. Conclusion: The frequency of familial cases of IIDD was 6.12% among MS patients and 2.8% in NMO spectrum syndromes.
Purpose: Temporal lobe epilepsy (TLE) is the most common variety of focal epilepsy among adults. ... more Purpose: Temporal lobe epilepsy (TLE) is the most common variety of focal epilepsy among adults. The neuroinflammatory mechanisms of epilepsies may be involved in the genesis of seizures and refractory epilepsies, particularly in the case of progressive syndromes such as TLE associated with mesial hippocampal sclerosis (TLE-HS). The goal of the present study is investigate the genetic profile of susceptibility of individuals with TLE-HS by analyzing the possible association of TLE-HS with human leukocyte antigen (HLA) DRB1, DQA1 and DQB1 alleles. Methods: Peripheral blood samples were collected from 42 individuals with pharmacoresistant TLE-HS and 89 healthy controls. The typing of the HLA class II alleles from DRB1, DQB1, and DQA1 loci were analyzed using sequence-specific primer-polymerase chain reaction (SSP-PCR) and identified through sequencing. Statistical analysis of relative allele frequencies was performed using an Excel spreadsheet; p-value, relative risk (RR), and odds ratio (OR) were calculated using the software Epi Info 6.0. p-values <0.05 following Bonferroni's method correction were considered statistically significant. Results: HLA-DRB1*13:02 was the only allele with a statistically significant difference (p = 0.01) in frequency between patients and controls. However, the significance was lost following Bonferroni's method correction (p = 0.44). The remainder of the alleles in the HLA-DRB1, HLA-DQB1 and HLA-DQA1 regions did not exhibit any significant association. Conclusion: The allele HLA DRB1*13:02 has exhibited a tendency to behave as a susceptibility factor for TLE-HS.
Background/Aims: Our aim was to investigate a geographical cluster of Huntington's disease (HD) i... more Background/Aims: Our aim was to investigate a geographical cluster of Huntington's disease (HD) in Ervalia, a Brazilian town of Minas Gerais state (MG). Therefore, we calculated the minimum prevalence of HD in Ervalia, known to have many HD affected families. We also determined the genetic profile of the polymorphic CAG region of the HTT gene in 32 subjects of these affected families. Methods: A descriptive cross-sectional study was performed, starting in January 2011 until June 2013. Individuals who participated in the survey were all from Ervalia town, MG. Results: The minimum prevalence rate found was 7.2/10,000 people, higher than the worldwide prevalence. Conclusion: The minimum prevalence of HD in Ervalia was at least 10.3-to 14.4-fold greater than that of the world population, although it does not represent the overall prevalence of the disease in Brazil. Certainly an expanded survey in the country will lead to a lower prevalence estimate than Ervalia's.
The major clinical features of monosomy 1p36 deletion are developmental delay and hypotonia assoc... more The major clinical features of monosomy 1p36 deletion are developmental delay and hypotonia associated with short stature and craniofacial dysmorphisms. The objective of this study was to review the cases of 1p36 deletion that was reported between 1999 and 2014, in order to identify a possible correlation between the size of the 1p36-deleted segment and the clinical phenotype of the disease. Scientific articles published in the (National Center for Biotechnology Information; NCBI http://www.ncbi.nlm. nih.gov/pubmed) and Scientific Electronic Library Online (www.scielo.com. br) databases were searched using key word combinations, such as " 1p36 deletion " , " monosomy 1p36 deletion " , and " 1p36 deletion syndrome ". Articles in English or Spanish reporting the correlation between deletion sizes and the respective clinical phenotypes were retrieved, while letters, reviews, guidelines, and studies with mouse models were excluded. Among the 746 retrieved articles, only 17 (12 case reports and 5 series of cases), comprising
Trehalase is the enzyme which hydrolyzes the disaccharide trehalose into two-D-glucose molecules.... more Trehalase is the enzyme which hydrolyzes the disaccharide trehalose into two-D-glucose molecules. In this article, we present the immobilization of trehalase on aminopropyl glass particles. The enzyme was extracted from Escherichia coli Mph2, a strain harboring the pTRE11 plasmid, which contains the trehalase gene. The partially purified enzyme had a specific activity of 356 U/mg and could be used for quantifying trehalose in the presence of sucrose, maltose, lactose, starch, and glycogen. Partially purified trehalase was immobilized by covalent coupling with retention of its catalytic activity. The support chosen for the majority of the experiments reported was aminopropyl glass, although spherisorb-5NH 2 and chitin were also tested. The immobilized enzyme was assayed continuously for 40 h, at pH 6.0 and 30°C, and no release of enzyme molecules was detected during this procedure. The best condition found for storing the enzyme–support complex was at 4°C in the presence of 25 mM sodium maleate, containing 7 mM-mer-captoethanol, 1 mM ethylenediaminetetraacetic acid (EDTA), and 50% glycerol. The enzyme under these conditions was stable, retaining approximately 100% of its initial activity for at least 28 days. The immobilized enzyme can be employed to detect trehalose molecules in micromolar concentration. The optimum pH value found was 4.5 and the K m app. 4.9 × 10 −3 M trehalose at pH 4.6 and 30°C, with V max of 5.88 µmol glucose min. −1 , as calculated by a Lineweaver–Burk plot.
Brazil, §Graduate Program in Human Movement Science—Universidade Castelo Branco, Rio de Janeiro, ... more Brazil, §Graduate Program in Human Movement Science—Universidade Castelo Branco, Rio de Janeiro, RJ, Brazil, and }Institute of Genetics and Biochemistry—Universidade Federal de Uberlâ ndia, Uberlâ ndia, MG, Brazil This article presents our experience on teaching biochemical sciences through an innovative approach that integrates concepts of molecular cell biology and protein chemistry. This original laboratory exercise is based on the preparation of an affinity chromatography column containing F-actin molecules immobilized on chitin particles for purifying skeletal myosin II. It favors the active learning of protein extraction and purification, the learning of concepts such as muscle contraction, cytoskeleton structure, and its importance for the living cell. This laboratory exercise also promotes learning biotechnological applications of chitin and the applications of protein immobilization in different industrial fields. Furthermore , the activities target the development of laboratorial abilities, problem-solving skills, and the ability to write a scientific report, following the model of a scientific article. The trials are mainly proposed for either an undergraduate project for advanced students in the life sciences or a postgraduate practical training course. In both the cases, the students must have had biochemistry as part of their regular curriculum. Alternatively, the affinity chromatography method can fit in any regular biochemistry course if active chitin, F-actin, and a myosin II extract are provided. It is very important to mention that this laboratory exercise can be used even in places where a facility such as ultracentrifugation is lacking. For that, the steps of actin purification are skipped, and actin is commercially obtained. Therefore, it is an adequate approach for the active learning of biochemical and molecular cell biology principles and techniques even in poor countries.
The aim of this article was to conduct a retrospective observational study on reported deaths due... more The aim of this article was to conduct a retrospective observational study on reported deaths due to Huntington's disease (HD) in Brazil in the past 25 years (from 1984 to 2008). Data were obtained from the Brazilian Mortality Information System (SIM/ DATASUS), the official system of Brazilian Mortality Database. The data obtained included information regarding the gender of the deceased and the number of death notifications, which we stratified by demographic regions and states. HD mortality per 100,000 was calculated and plotted in a graph. Linear regression was calculated using ordinary least square technique. We observed that the mortality due to HD recorded by SIM/DATASUS from 1984 to 2008 had increased at much higher rates than the population in the same period. Also, some Brazilian regions still show very low rates of HD mortality compared to the national average of deaths due to HD. These findings suggest that
Huntington&amp;amp;#39;s disease (HD) is a rare progressive and fatal neurogenetic degenerati... more Huntington&amp;amp;#39;s disease (HD) is a rare progressive and fatal neurogenetic degenerative disease, characterized by movement and personality disorders and by progressive dementia. Its prevalence varies by ethnic origin and different genetic profiles predisposing individuals to HD in each population. The prevalence of HD is 5-10 per 100,000 individuals in Caucasian populations of North America and Western Europe. It is an autosomal dominant disease associated with the expansion of CAG-type repetitive DNA sequences in the HTT gene. This gene, located on the short arm of chromosome 4, encodes the protein huntingtin. In this study, we reviewed 17 articles about HD that report data from 2400 affected individuals from various countries around the world, including Venezuela, China, Croatia, Turkey, Germany, Italy, Brazil, Spain, Taiwan, India, the Netherlands, Russia, and the USA, with a focus on genetic profiles and intergenerational expansions or contractions of expanded alleles responsible for causing HD. We discuss the genetic characteristics of HD in different populations and any atypical cases reported in these studies.
Trehalose is a disaccharide present in a variety of anhydrobiotic organisms which have the abilit... more Trehalose is a disaccharide present in a variety of anhydrobiotic organisms which have the ability to promptly resume their metabolism after addition of water. It has been successfully used as a nontoxic cryoprotectant of enzymes, membranes, vaccines, animal and plant cells and organs for surgical transplants. It has been predicted that trehalose can also be used as an ingredient for dried and processed food. Therefore, the recent biotechnological applications of trehalose have imposed the standardization of methods for its production, as well as for its specific quantification. Biochemistry and biotechnology were born out of studies with yeast cells. In fact biotechnology preceded the basic science. Early Egyptians already prepared their dough, a simple mixture of flour and water and kept it warm until bubbles began to form. They also delighted in drinking the fermented fruit juices accepting them as a gift from the Gods. Throughout the first half of the 19th century those few scientists who had grasped the truth about yeast had difficulties in imposing their views: fermentation was considered to be a purely chemical reaction in which life was not involved. Only when Pasteur in 1850 turned his attention to fermentation and brewing was it shown that yeast cells were capable of transforming sugar in alcohol. Biochemistry was born soon after, when Edward Buchner in 1896, ground yeast cells with sand and pressed them to obtain an extract for pharmaceutical purposes. In order to preserve it he added sugar. To his surprise, even though the yeast integrity had been destroyed, the fluid was still able to ferment. The enzymes had remained active. The biochemical process involved was identified for both fermentation and raising of dough. Yeast are racing with bacteria for the lead position in biotechnology. They share with animal cells many of the molecules and processes that are subject of intensive study in molecular biology. Moreover, unlike bacterial cells, which must be broken to retrieve a produced heterologous protein, yeast cells are able to secrete the product beyond their cell wall. Furthermore, there is another advantage to the use of yeast cells in biotechnology, it is a psychological advantage. While people tend to associate bacteria with diseases, yeast has been associated, over millennia, with the good things of life, i.e., bread and wine.
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