This study aims to map the vulnerability of flood in Banjar district is based on variable rainfal... more This study aims to map the vulnerability of flood in Banjar district is based on variable rainfall, soil type, land cover, and slope. From the results of this study concluded that the level of vulnerability to flooding in South Kalimantan Banjar district can be categorized into five, namely; namely the vulnerability of flood-prone, flood potential is rather prone to flooding, flood-prone and highly prone to flooding. Areas of potential flooding are in part the District Aranio an area affected by potential flooding 12:15 Ha or 2.71%, District and Sub-district Martapura Aranio with an area of 85.36 hectares or 19.03% potential, River District Pinang, Mataraman, Astambul, Peat, partly Aranio and partly Pengaron. Areas affected by the floods is estimated an area of 18.72 ha, or the potential flooding of 4.17%. Sungai Pinang, Mataraman, Astambul, Peat, partly Aranio and partly Pengaron. Areas affected by the floods is estimated area of 227.65 hectares or 50.76% of the potential flooding. And districts Sungai Pinang, Mataraman, Astambul, Peat, partly Aranio and partly Pengaron. Areas affected by the floods is estimated area of 104.53 hectares or 23.31% of the potential flooding.
The Uses of Solar Energy Each House can Give More Opportunity of Supply Electricity More Houses in Bangladesh
DESCRIPTION The energy requirements of the world are increasing at an alarming rate and the deman... more DESCRIPTION The energy requirements of the world are increasing at an alarming rate and the demand of power has been running ahead of supply. It is now widely recognized that the fossil fuels (i.e., coal, petroleum and natural gas) and other conventional resources, presently being used for generation of electrical energy, may not be either sufficient or suitable to keep pace with ever increasing demand of the electricity of the world. Generation of electrical power by coal based steam power plant or nuclear power plants also causes pollution. This is likely to be more acute in future due to large generating capacity and greater awareness of the people in this respect. Recent severe energy crisis has forced the world to develop new and alternative methods of power generation, which could not be adopted so far due to various reasons. The magneto-hydro-dynamic (MHD) power generation is one of the examples of a new unique method of power generation. The other non-conventional methods of...
Electrochemical impedance spectroscopy measurements of pulsed laser deposited single crystal anat... more Electrochemical impedance spectroscopy measurements of pulsed laser deposited single crystal anatase TiO2 thin films with various concentrations of Ta substituting for Ti were carried out. The qualities of the films were characterized by X-ray diffraction and Rutherford back scattering-channeling measurements. UV-visible measurements show a systematic increase of the bandgap with Ta incorporation. Corresponding Mott-Schottky plot was applied to obtain a continuous shift of the flat band potential with increasing free charge carrier (provided by Ta) concentration. This was verified theoretically by ab initio calculation which shows that extra Ta d-electrons occupy Ti t2g orbital with increasing Ta concentration, thereby pushing up the Fermi level. The Mott-Schottky results were consistent when compared with Hall effect and temperature dependent resistivity measurements. From the measured deviation of carrier densities from Hall and Mott-Schottky measurements we have estimated the sta...
Washing of Animal Body Coat Effects on Salmonella Load on Hide and in Postslaughter Carcasses
Sylwan
ABSTRACT Present study was carried out to find reduction in the level of Salmonella contamination... more ABSTRACT Present study was carried out to find reduction in the level of Salmonella contamination in meat form public health point of view. Reduction in load of Salmonella on cattle body coats (hides) and in carcasses against the use of various washing treatments of the animals before slaughtering e.g. cleaning with; i. water, ii. Water plus soap iii. Water plus soap plus Dettol, iv. No washing (control). These treatments were applied on the cattle body coats of live cattle prior to slaughter, concurrently in following three groups i. fresh water, ii. 50 0C heated water and iii. 70 0C heated water. Samples were also collected after slaughtering from these groups which were treated against different treatments. In second part of the experiment, meat transporting vehicles were also washed to check the reduction in Salmonella prevalence. Total samples (n= 88) comprised of washed samples (n= 59) and unwashed (n=29). Data was transformed into log (LNTVC) for clearer understanding. All collected samples were positive for Salmonella contamination. A large number of colonies were observed and recorded as total viable count (TVC). Salmonella on the surface of unwashed (controlled) live animal coat (26.07± 0.03) was significantly (P <0.01) higher (24%) than Salmonella in carcasses (21.26± 0.04). Samples of treatment i.e. water plus soap plus Dettol showed highest 65% reduction in the level of Salmonella against group which used 70 0C heated water during washing of animal body coat respectively. Similarly level of Salmonella in carcasses reduced maximum in the group washed with 70 0C heated water. Mean Salmonella contamination on body coat decreased as samples moved controlled animals body coat (unwashed) to soap washed and soap plus Dettol wash 26.07± 0.03, 20.78±0.03, 13.37± 0.11 and 10.49±0.13 respectively. It is concluded that the washing with water, soap and Dettol at 70 0C Heat Water has significantly lesser load of salmonella. However the sanitizer application did not completely vanish the salmonella in the carcasses. This suggested that abattoir management at Peshawar should focus on the improvement of hygiene in all aspect of slaughterhouse.
Dairy products are colonized with three main classes of lactic acid bacteria (LAB): opportunistic... more Dairy products are colonized with three main classes of lactic acid bacteria (LAB): opportunistic bacteria, traditional starters, and industrial starters. Most of the population structure studies were previously performed with LAB species belonging to these three classes and give interesting knowledge about the population structure of LAB at the stage where they are already industrialized. However, these studies give little information about the population structure of LAB prior their use as an industrial starter. Carnobacterium maltaromaticum is a LAB colonizing diverse environments, including dairy products. Since this bacterium was discovered relatively recently, it is not yet commercialized as an industrial starter, which makes C. maltaromaticum an interesting model for the study of unindustrialized LAB population structure in dairy products. A multilocus sequence typing scheme based on an analysis of fragments of the genes dapE, ddlA, glpQ, ilvE, pyc, pyrE, and leuS was applied...
The observation of a high-mobility two-dimensional electron gas between two insulating complex ox... more The observation of a high-mobility two-dimensional electron gas between two insulating complex oxides, especially LaAlO 3 /SrTiO 3 , has enhanced the potential of oxides for electronics. The occurrence of this conductivity is believed to be driven by polarization discontinuity, leading to an electronic reconstruction. In this scenario, the crystal orientation has an important role and no conductivity would be expected, for example, for the interface between LaAlO 3 and (110)-oriented SrTiO 3 , which should not have a polarization discontinuity. Here we report the observation of unexpected conductivity at the LaAlO 3 / SrTiO 3 interface prepared on (110)-oriented SrTiO 3 , with a LaAlO 3 -layer thickness-dependent metal-insulator transition. Density functional theory calculation reveals that electronic reconstruction, and thus conductivity, is still possible at this (110) interface by considering the energetically favourable (110) interface structure, that is, buckled TiO 2 /LaO, in which the polarization discontinuity is still present. The conductivity was further found to be strongly anisotropic along the different crystallographic directions with potential for anisotropic superconductivity and magnetism, leading to possible new physics and applications.
Physical properties of Eu^3+ doped sodium magnesium alumino-silicate glasses studied by light scattering spectroscopy
Brillouin scattering and absorption measurements on various Al and Na concentrations of Europium ... more Brillouin scattering and absorption measurements on various Al and Na concentrations of Europium doped sodium magnesium alumino-silicate glasses (ESMAS) were performed to study the glass structures and optical properties of ESMAS. The linewidth, frequency shift, and intensity of Brillouin peaks were determined to calculate the phonon attenuation, elastic constants, photo-elastic coefficients, and the bond polarizability parameter. The parameters obtained from this study shows that the glass structures become more rigid and ionic with increasing Al content, while the glass structures show more ionic and less rigid with increasing Na concentration. The Judd-Ofelt intensity parameter, Omega_6, obtained from absorption measurements agrees with the Brillouin scattering results.
For the first time bovine trichomoniasis has been diagnosed in Bangladesh. A cow failed to concei... more For the first time bovine trichomoniasis has been diagnosed in Bangladesh. A cow failed to conceive following two consecutive heat periods and while it was being examined per rectum during the third heat period some vaginal mucous exuded which was offensive in odour, cloudy in colour and contained some flecks of pus. The mucous was subjected to microscopical examination using the technique described by Kendrick (1963). On the third slide two motile trichomonas organisms were detected. The vagina was douched with I : 30 dilution of Lugol's iodine and an injection of oxytetracycline (3 mg/lb body weight) was prescribed for the next 4 days. The cow was served by artificial insemination on the second heat period following the treatment and was found to be pregnant 45 days later on rectal examination. A survey was yet to be made on the identity of the various infectious diseases of cattle in Bangladesh. However, this is a first report on the presence of bovine trichomoniasis in this country. Accepted for publication November 1973
The effects of UV-photodegraded -carotene (C) and lycopene (Lyc) on immune function parameters ... more The effects of UV-photodegraded -carotene (C) and lycopene (Lyc) on immune function parameters of human peripheral blood mononuclear cells (PBMC) was investigated. C (8.6 -10.0 g/ml) inhibited 3 H-thymidine incorporation by PBMC an average of 81%, 64% and 66%, when stimulated with Concanavalin A (Con A), phytohemagglutinin (PHA) and lipopolysaccharide (LPS), respectively, without affecting cell viability. C and Lyc inhibited Con A and LPS-stimulated proliferation similarly, indicating activity due to nonretinoid products. C inhibited IL-2 synthesis by stimulated PBMC, and rIL-2 addition partially reversed inhibition. C exposure only during the initial 6 hrs inhibited proliferation, and inhibition was maximal even if C addition occurred 8 hrs after mitogen addition. C treatment resulted in arrest of cells in G 0 ϩ G 1 . Antiproliferative activity was associated with a fraction soluble in ethanol but not water. These results suggest that inhibition of proliferation by C occurs downstream of mitogen binding. -carotene and lycopene undergo photodegradation in human skin in vivo, and these findings suggest that phenomenon may influence aspects of immune function.
Smokers have lower levels of serum carotenoids and have higher incidence of lung cancer. As a par... more Smokers have lower levels of serum carotenoids and have higher incidence of lung cancer. As a part of our interest in the role of smoke-degraded carotenoids in lung cancer, we investigated the extent of -carotene degradation by gaseous phase of cigarette smoke, and the kinetics of its degradation in vitro at 20°C. We also determined the preliminary spectral characteristics of smokedegraded -carotene. On average, 78% of -carotene solution in hexane (7.0 M) was degraded by 12 puffs of smoke (equivalent to two cigarettes) over an exposure period of four hours. Degradation followed first-order kinetics with a 40.7% decrease in -carotene concentration for each log unit of cigarette smoke exposure (r 2 ϭ 0.986). The degradation products absorb maximally at much lower wavelengths compared to intact -carotene, and give a diffused absorbance band between 320 -410 nm. Further work is needed to determine the extent of carotenoids degradation by cigarette smoke in vivo, to identify the degradation products and to elucidate the role of such products in lung carcinogenesis.
Carotenoids are degraded in humans upon UV exposure, although the effects of their photodegradati... more Carotenoids are degraded in humans upon UV exposure, although the effects of their photodegradation products are largely unknown. We studied the effects of photodegraded -carotene (C) and lycopene (Lyc) on proliferation of murine T-cell (LBRM-33 and CTLL-2) and B-cell (BCL-1) cells. In LBRM-33 cells, C (3.5-4.0 g/ml) inhibited 3 H-thymidine incorporation by 44 and 37 percent in non-stimulated and Con A-treated cells, respectively, without affecting cell viability. In IL-2 dependent CTLL-2 cells, C (0.2-2.1 g/ml) exhibited stimulatory or inhibitory effects depending on IL-2 concentration. At 3.5 g/ml, C caused 50, 91 and 98 percent inhibition of proliferation in CTLL-2 cultures containing 5, 10, and 20 units rIL-2/ml respectively, without affecting viability. In BCL-1 cells, 2.1-3.5 g/ml C decreased proliferation of cells by 42 and 37 percent in non-stimulated and LPS-stimulated cells, respectively. Lyc produced effects similar to C, indicating that provitamin A activity was not required for the effect. These results are consistent with previous findings that C and Lyc inhibit mitogen-induced proliferation of human peripheral mononuclear cells.
Over activation of hippocampal serine/threonine protein phosphatases PP1 and PP2A is involved in lead-induced deficits in learning and memory in young rats
NeuroToxicology, 2012
Serine/threonine protein phosphatases regulate several key cellular events in the brain, includin... more Serine/threonine protein phosphatases regulate several key cellular events in the brain, including learning and memory. These enzymes, when over-activated, are known to function as a constraint on learning and memory. We investigated whether these phosphatases are implicated in lead (Pb)-induced deficits in learning and memory. Wistar rat pups were exposed to 0.2% Pb-acetate via their dams' drinking water from postnatal day (PND) 1-21 and directly in drinking water until PND 30. Pb levels in blood, brain and hippocampus were measured and expression of PP1, PP2A, PP2B and PP5 in hippocampus was analyzed. Total phosphatase activity, and PP1 and PP2A activities were determined. Tau phosphorylation at various epitopes was determined by Western blot. Spatial learning and memory was determined by Morris water maze test. Pb exposure significantly increased levels of Pb in blood, brain and hippocampus, reduced the number of synapses in hippocampus and impaired learning and long-term memory (LTM). Short-term memory (STM) was only affected in rats at PND21. Pb exposure increased the expression and activity of PP1 and decreased phosphorylation of tau at threonine-231 in hippocampus at both PND21 and PND30. Pb-induced phosphorylation of tau at serine-199/202 (AT8) paralleled with PP2A activity; at PND21 PP2A activity increased and AT8 phosphorylation decreased; at PND30 PP2A activity decreased and AT8 phosphorylation increased. Increased PP1 activity in hippocampus by Pb is associated with learning and LTM impairment, whereas, increased PP2A activity is associated with STM impairment. These findings suggest the overactivation of PP1 and PP2A, together with changes in tau phosphorylation, as a potential mechanism of lead-induced deficits in learning and memory.
Phosphothreonine-212 of Alzheimer Abnormally Hyperphosphorylated Tau is a Preferred Substrate of Protein Phosphatase-1
Neurochemical Research, 2005
We isolated and characterized several phosphoseryl/phosphothreonyl phosphatase activities (P1–P11... more We isolated and characterized several phosphoseryl/phosphothreonyl phosphatase activities (P1–P11) from frontal lobe of six autopsied human brains. Of these, PP1 (P3) was a major tau phosphatase. The enzyme required metal ions and was maximally activated by Mn2+. Western blots with antibodies to known protein phosphatases showed PP1 and PP2B immunoreactivity. However, the removal of PP2B by immunoabsorption or its inhibition
Lab-on-a-chip technology: impacting non-invasive prenatal diagnostics (NIPD) through miniaturisation
Lab on a Chip, 2014
This paper aims to provide a concise review of non-invasive prenatal diagnostics (NIPD) to the la... more This paper aims to provide a concise review of non-invasive prenatal diagnostics (NIPD) to the lab-on-a-chip and microfluidics community. Having a market of over one billion dollars to explore and a plethora of applications, NIPD requires greater attention from microfluidics researchers. In this review, a complete overview of conventional diagnostic procedures including invasive as well as non-invasive (fetal cells and cell-free fetal DNA) types are discussed. Special focus is given to reviewing the recent and past microfluidic approaches to NIPD, as well as various commercial entities in NIPD. This review concludes with future challenges and ethical considerations of the field.
This study aims to map the vulnerability of flood in Banjar district is based on variable rainfal... more This study aims to map the vulnerability of flood in Banjar district is based on variable rainfall, soil type, land cover, and slope. From the results of this study concluded that the level of vulnerability to flooding in South Kalimantan Banjar district can be categorized into five, namely; namely the vulnerability of flood-prone, flood potential is rather prone to flooding, flood-prone and highly prone to flooding. Areas of potential flooding are in part the District Aranio an area affected by potential flooding 12:15 Ha or 2.71%, District and Sub-district Martapura Aranio with an area of 85.36 hectares or 19.03% potential, River District Pinang, Mataraman, Astambul, Peat, partly Aranio and partly Pengaron. Areas affected by the floods is estimated an area of 18.72 ha, or the potential flooding of 4.17%. Sungai Pinang, Mataraman, Astambul, Peat, partly Aranio and partly Pengaron. Areas affected by the floods is estimated area of 227.65 hectares or 50.76% of the potential flooding. And districts Sungai Pinang, Mataraman, Astambul, Peat, partly Aranio and partly Pengaron. Areas affected by the floods is estimated area of 104.53 hectares or 23.31% of the potential flooding.
The Uses of Solar Energy Each House can Give More Opportunity of Supply Electricity More Houses in Bangladesh
DESCRIPTION The energy requirements of the world are increasing at an alarming rate and the deman... more DESCRIPTION The energy requirements of the world are increasing at an alarming rate and the demand of power has been running ahead of supply. It is now widely recognized that the fossil fuels (i.e., coal, petroleum and natural gas) and other conventional resources, presently being used for generation of electrical energy, may not be either sufficient or suitable to keep pace with ever increasing demand of the electricity of the world. Generation of electrical power by coal based steam power plant or nuclear power plants also causes pollution. This is likely to be more acute in future due to large generating capacity and greater awareness of the people in this respect. Recent severe energy crisis has forced the world to develop new and alternative methods of power generation, which could not be adopted so far due to various reasons. The magneto-hydro-dynamic (MHD) power generation is one of the examples of a new unique method of power generation. The other non-conventional methods of...
Electrochemical impedance spectroscopy measurements of pulsed laser deposited single crystal anat... more Electrochemical impedance spectroscopy measurements of pulsed laser deposited single crystal anatase TiO2 thin films with various concentrations of Ta substituting for Ti were carried out. The qualities of the films were characterized by X-ray diffraction and Rutherford back scattering-channeling measurements. UV-visible measurements show a systematic increase of the bandgap with Ta incorporation. Corresponding Mott-Schottky plot was applied to obtain a continuous shift of the flat band potential with increasing free charge carrier (provided by Ta) concentration. This was verified theoretically by ab initio calculation which shows that extra Ta d-electrons occupy Ti t2g orbital with increasing Ta concentration, thereby pushing up the Fermi level. The Mott-Schottky results were consistent when compared with Hall effect and temperature dependent resistivity measurements. From the measured deviation of carrier densities from Hall and Mott-Schottky measurements we have estimated the sta...
Washing of Animal Body Coat Effects on Salmonella Load on Hide and in Postslaughter Carcasses
Sylwan
ABSTRACT Present study was carried out to find reduction in the level of Salmonella contamination... more ABSTRACT Present study was carried out to find reduction in the level of Salmonella contamination in meat form public health point of view. Reduction in load of Salmonella on cattle body coats (hides) and in carcasses against the use of various washing treatments of the animals before slaughtering e.g. cleaning with; i. water, ii. Water plus soap iii. Water plus soap plus Dettol, iv. No washing (control). These treatments were applied on the cattle body coats of live cattle prior to slaughter, concurrently in following three groups i. fresh water, ii. 50 0C heated water and iii. 70 0C heated water. Samples were also collected after slaughtering from these groups which were treated against different treatments. In second part of the experiment, meat transporting vehicles were also washed to check the reduction in Salmonella prevalence. Total samples (n= 88) comprised of washed samples (n= 59) and unwashed (n=29). Data was transformed into log (LNTVC) for clearer understanding. All collected samples were positive for Salmonella contamination. A large number of colonies were observed and recorded as total viable count (TVC). Salmonella on the surface of unwashed (controlled) live animal coat (26.07± 0.03) was significantly (P <0.01) higher (24%) than Salmonella in carcasses (21.26± 0.04). Samples of treatment i.e. water plus soap plus Dettol showed highest 65% reduction in the level of Salmonella against group which used 70 0C heated water during washing of animal body coat respectively. Similarly level of Salmonella in carcasses reduced maximum in the group washed with 70 0C heated water. Mean Salmonella contamination on body coat decreased as samples moved controlled animals body coat (unwashed) to soap washed and soap plus Dettol wash 26.07± 0.03, 20.78±0.03, 13.37± 0.11 and 10.49±0.13 respectively. It is concluded that the washing with water, soap and Dettol at 70 0C Heat Water has significantly lesser load of salmonella. However the sanitizer application did not completely vanish the salmonella in the carcasses. This suggested that abattoir management at Peshawar should focus on the improvement of hygiene in all aspect of slaughterhouse.
Dairy products are colonized with three main classes of lactic acid bacteria (LAB): opportunistic... more Dairy products are colonized with three main classes of lactic acid bacteria (LAB): opportunistic bacteria, traditional starters, and industrial starters. Most of the population structure studies were previously performed with LAB species belonging to these three classes and give interesting knowledge about the population structure of LAB at the stage where they are already industrialized. However, these studies give little information about the population structure of LAB prior their use as an industrial starter. Carnobacterium maltaromaticum is a LAB colonizing diverse environments, including dairy products. Since this bacterium was discovered relatively recently, it is not yet commercialized as an industrial starter, which makes C. maltaromaticum an interesting model for the study of unindustrialized LAB population structure in dairy products. A multilocus sequence typing scheme based on an analysis of fragments of the genes dapE, ddlA, glpQ, ilvE, pyc, pyrE, and leuS was applied...
The observation of a high-mobility two-dimensional electron gas between two insulating complex ox... more The observation of a high-mobility two-dimensional electron gas between two insulating complex oxides, especially LaAlO 3 /SrTiO 3 , has enhanced the potential of oxides for electronics. The occurrence of this conductivity is believed to be driven by polarization discontinuity, leading to an electronic reconstruction. In this scenario, the crystal orientation has an important role and no conductivity would be expected, for example, for the interface between LaAlO 3 and (110)-oriented SrTiO 3 , which should not have a polarization discontinuity. Here we report the observation of unexpected conductivity at the LaAlO 3 / SrTiO 3 interface prepared on (110)-oriented SrTiO 3 , with a LaAlO 3 -layer thickness-dependent metal-insulator transition. Density functional theory calculation reveals that electronic reconstruction, and thus conductivity, is still possible at this (110) interface by considering the energetically favourable (110) interface structure, that is, buckled TiO 2 /LaO, in which the polarization discontinuity is still present. The conductivity was further found to be strongly anisotropic along the different crystallographic directions with potential for anisotropic superconductivity and magnetism, leading to possible new physics and applications.
Physical properties of Eu^3+ doped sodium magnesium alumino-silicate glasses studied by light scattering spectroscopy
Brillouin scattering and absorption measurements on various Al and Na concentrations of Europium ... more Brillouin scattering and absorption measurements on various Al and Na concentrations of Europium doped sodium magnesium alumino-silicate glasses (ESMAS) were performed to study the glass structures and optical properties of ESMAS. The linewidth, frequency shift, and intensity of Brillouin peaks were determined to calculate the phonon attenuation, elastic constants, photo-elastic coefficients, and the bond polarizability parameter. The parameters obtained from this study shows that the glass structures become more rigid and ionic with increasing Al content, while the glass structures show more ionic and less rigid with increasing Na concentration. The Judd-Ofelt intensity parameter, Omega_6, obtained from absorption measurements agrees with the Brillouin scattering results.
For the first time bovine trichomoniasis has been diagnosed in Bangladesh. A cow failed to concei... more For the first time bovine trichomoniasis has been diagnosed in Bangladesh. A cow failed to conceive following two consecutive heat periods and while it was being examined per rectum during the third heat period some vaginal mucous exuded which was offensive in odour, cloudy in colour and contained some flecks of pus. The mucous was subjected to microscopical examination using the technique described by Kendrick (1963). On the third slide two motile trichomonas organisms were detected. The vagina was douched with I : 30 dilution of Lugol's iodine and an injection of oxytetracycline (3 mg/lb body weight) was prescribed for the next 4 days. The cow was served by artificial insemination on the second heat period following the treatment and was found to be pregnant 45 days later on rectal examination. A survey was yet to be made on the identity of the various infectious diseases of cattle in Bangladesh. However, this is a first report on the presence of bovine trichomoniasis in this country. Accepted for publication November 1973
The effects of UV-photodegraded -carotene (C) and lycopene (Lyc) on immune function parameters ... more The effects of UV-photodegraded -carotene (C) and lycopene (Lyc) on immune function parameters of human peripheral blood mononuclear cells (PBMC) was investigated. C (8.6 -10.0 g/ml) inhibited 3 H-thymidine incorporation by PBMC an average of 81%, 64% and 66%, when stimulated with Concanavalin A (Con A), phytohemagglutinin (PHA) and lipopolysaccharide (LPS), respectively, without affecting cell viability. C and Lyc inhibited Con A and LPS-stimulated proliferation similarly, indicating activity due to nonretinoid products. C inhibited IL-2 synthesis by stimulated PBMC, and rIL-2 addition partially reversed inhibition. C exposure only during the initial 6 hrs inhibited proliferation, and inhibition was maximal even if C addition occurred 8 hrs after mitogen addition. C treatment resulted in arrest of cells in G 0 ϩ G 1 . Antiproliferative activity was associated with a fraction soluble in ethanol but not water. These results suggest that inhibition of proliferation by C occurs downstream of mitogen binding. -carotene and lycopene undergo photodegradation in human skin in vivo, and these findings suggest that phenomenon may influence aspects of immune function.
Smokers have lower levels of serum carotenoids and have higher incidence of lung cancer. As a par... more Smokers have lower levels of serum carotenoids and have higher incidence of lung cancer. As a part of our interest in the role of smoke-degraded carotenoids in lung cancer, we investigated the extent of -carotene degradation by gaseous phase of cigarette smoke, and the kinetics of its degradation in vitro at 20°C. We also determined the preliminary spectral characteristics of smokedegraded -carotene. On average, 78% of -carotene solution in hexane (7.0 M) was degraded by 12 puffs of smoke (equivalent to two cigarettes) over an exposure period of four hours. Degradation followed first-order kinetics with a 40.7% decrease in -carotene concentration for each log unit of cigarette smoke exposure (r 2 ϭ 0.986). The degradation products absorb maximally at much lower wavelengths compared to intact -carotene, and give a diffused absorbance band between 320 -410 nm. Further work is needed to determine the extent of carotenoids degradation by cigarette smoke in vivo, to identify the degradation products and to elucidate the role of such products in lung carcinogenesis.
Carotenoids are degraded in humans upon UV exposure, although the effects of their photodegradati... more Carotenoids are degraded in humans upon UV exposure, although the effects of their photodegradation products are largely unknown. We studied the effects of photodegraded -carotene (C) and lycopene (Lyc) on proliferation of murine T-cell (LBRM-33 and CTLL-2) and B-cell (BCL-1) cells. In LBRM-33 cells, C (3.5-4.0 g/ml) inhibited 3 H-thymidine incorporation by 44 and 37 percent in non-stimulated and Con A-treated cells, respectively, without affecting cell viability. In IL-2 dependent CTLL-2 cells, C (0.2-2.1 g/ml) exhibited stimulatory or inhibitory effects depending on IL-2 concentration. At 3.5 g/ml, C caused 50, 91 and 98 percent inhibition of proliferation in CTLL-2 cultures containing 5, 10, and 20 units rIL-2/ml respectively, without affecting viability. In BCL-1 cells, 2.1-3.5 g/ml C decreased proliferation of cells by 42 and 37 percent in non-stimulated and LPS-stimulated cells, respectively. Lyc produced effects similar to C, indicating that provitamin A activity was not required for the effect. These results are consistent with previous findings that C and Lyc inhibit mitogen-induced proliferation of human peripheral mononuclear cells.
Over activation of hippocampal serine/threonine protein phosphatases PP1 and PP2A is involved in lead-induced deficits in learning and memory in young rats
NeuroToxicology, 2012
Serine/threonine protein phosphatases regulate several key cellular events in the brain, includin... more Serine/threonine protein phosphatases regulate several key cellular events in the brain, including learning and memory. These enzymes, when over-activated, are known to function as a constraint on learning and memory. We investigated whether these phosphatases are implicated in lead (Pb)-induced deficits in learning and memory. Wistar rat pups were exposed to 0.2% Pb-acetate via their dams' drinking water from postnatal day (PND) 1-21 and directly in drinking water until PND 30. Pb levels in blood, brain and hippocampus were measured and expression of PP1, PP2A, PP2B and PP5 in hippocampus was analyzed. Total phosphatase activity, and PP1 and PP2A activities were determined. Tau phosphorylation at various epitopes was determined by Western blot. Spatial learning and memory was determined by Morris water maze test. Pb exposure significantly increased levels of Pb in blood, brain and hippocampus, reduced the number of synapses in hippocampus and impaired learning and long-term memory (LTM). Short-term memory (STM) was only affected in rats at PND21. Pb exposure increased the expression and activity of PP1 and decreased phosphorylation of tau at threonine-231 in hippocampus at both PND21 and PND30. Pb-induced phosphorylation of tau at serine-199/202 (AT8) paralleled with PP2A activity; at PND21 PP2A activity increased and AT8 phosphorylation decreased; at PND30 PP2A activity decreased and AT8 phosphorylation increased. Increased PP1 activity in hippocampus by Pb is associated with learning and LTM impairment, whereas, increased PP2A activity is associated with STM impairment. These findings suggest the overactivation of PP1 and PP2A, together with changes in tau phosphorylation, as a potential mechanism of lead-induced deficits in learning and memory.
Phosphothreonine-212 of Alzheimer Abnormally Hyperphosphorylated Tau is a Preferred Substrate of Protein Phosphatase-1
Neurochemical Research, 2005
We isolated and characterized several phosphoseryl/phosphothreonyl phosphatase activities (P1–P11... more We isolated and characterized several phosphoseryl/phosphothreonyl phosphatase activities (P1–P11) from frontal lobe of six autopsied human brains. Of these, PP1 (P3) was a major tau phosphatase. The enzyme required metal ions and was maximally activated by Mn2+. Western blots with antibodies to known protein phosphatases showed PP1 and PP2B immunoreactivity. However, the removal of PP2B by immunoabsorption or its inhibition
Lab-on-a-chip technology: impacting non-invasive prenatal diagnostics (NIPD) through miniaturisation
Lab on a Chip, 2014
This paper aims to provide a concise review of non-invasive prenatal diagnostics (NIPD) to the la... more This paper aims to provide a concise review of non-invasive prenatal diagnostics (NIPD) to the lab-on-a-chip and microfluidics community. Having a market of over one billion dollars to explore and a plethora of applications, NIPD requires greater attention from microfluidics researchers. In this review, a complete overview of conventional diagnostic procedures including invasive as well as non-invasive (fetal cells and cell-free fetal DNA) types are discussed. Special focus is given to reviewing the recent and past microfluidic approaches to NIPD, as well as various commercial entities in NIPD. This review concludes with future challenges and ethical considerations of the field.
Uploads
Papers by Abdur Rahman