Papers by michael rodriguez
The Journal of organic chemistry, Jan 8, 1996
A unique semisynthetic pathway has been used as a route to novel R106 derivatives. R106-sarcosine... more A unique semisynthetic pathway has been used as a route to novel R106 derivatives. R106-sarcosine, 2, was discovered to be a key intermediate to obtain these derivatives using classical aldol alkylation conditions. Surprisingly, the site of alkylation on 2 was found to be conformationally hindered which yielded both the D and L isomers of R106-1 (aureobasidin A), 1, and other new R106 derivatives. The scope of the alkylation was found to be highly dependent upon the reactivity potential of the electrophile. Semiempirical calculations on R106-1 and 8-(N-methylthrenonine)aureobasidin A, 7, were performed to investigate the thermodynamic stabilities of the D and L isomers. By contrast to stable conformations observed by two X-ray crystal structures of aureobasidins, the calculations indicated that the D isomers were significantly more stable. Furthermore, model semiempirical calculations to probe facial selecitivty were consistent with results obtained experimentally.
Certain derivatives of the glycopeptide antibiotic LY264826 with N-alkyl-linked substitutions on ... more Certain derivatives of the glycopeptide antibiotic LY264826 with N-alkyl-linked substitutions on the epi- vancosaminesugarareactiveagainstglycopeptide-resistantenterococci.Sixcompoundsrepresentingourmost active series were evaluated for activity against antibiotic-resistant, gram-positive pathogens. ForEnterococcus faecium and E. faecalis resistant to both vancomycin and teicoplanin, the MICs of the six semisynthetic compoundsfor90%ofthestrainstestedwere1to4 mg/ml,comparedwith2,048 mg/mlforvancomycinand256 mg/ml for LY264826. ForE. faeciumandE. faecalisresistant to vancomycin but not teicoplanin, the MICs were 0.016 to
Bioorganic & Medicinal Chemistry Letters, 2000
A series of aliphatic side-chain analogues of pseudomycin was synthesized and evaluated during th... more A series of aliphatic side-chain analogues of pseudomycin was synthesized and evaluated during the course of our side-chain SAR effort. We found that several of the pseudomycin side-chain analogues (e.g., 10) exhibited good in vitro activity against all three major fungi responsible for systemic fungal infections.
Journal of Medicinal Chemistry, 1995
Echinocandin B (ECB) is a lipopeptide composed of a complex cyclic peptide acylated at the N-term... more Echinocandin B (ECB) is a lipopeptide composed of a complex cyclic peptide acylated at the N-terminus by linoleic acid. Enzymatic deacylation of ECB provided the peptide "nucleus" as a biologically inactive substrate from which novel ECB analogs were generated by chemical reacylation at the N-terminus. Varying the acyl group revealed that the structure and physical properties of the side chain, particularly its geometry and lipophilicity, played a pivotal role in determining the antifungal potency properties of the analog. Using CLOGP values to describe and compare the lipophilicities of the side chain fragments, it was shown that values of > 3.5 were required for expression of antifungal activity. Secondly, a linearly rigid geometry of the side chain was the most effective shape in enhancing the antifungal potency. Using these parameters as a guide, a variety of novel ECB analogs were synthesized which included arylacyl groups that incorporated biphenyl, terphenyl, tetraphenyl, and arylethynyl groups. Generally the glucan synthase inhibition by these analogs correlated well with in vitro and in vivo activities and was likewise influenced by the structure of the side chain. These structural variations resulted in enhancement of antifungal activity in both in vitro and in vivo assays. Some of these analogs, including LY303366 (14a), were effective by the oral route of administration.
Journal of Medicinal Chemistry, 2001
With the aim of increasing therapeutic indexes of novel cyclic depsinonapeptide pseudomycins, we ... more With the aim of increasing therapeutic indexes of novel cyclic depsinonapeptide pseudomycins, we synthesized and evaluated a series of mono-, di-, and trioxodioxolenylmethyl carbamate prodrugs (2 and 4) of pseudomycin B 1 and pseudomycin C' 3. It is rather encouraging to note that several members of the newly synthesized prodrugs described herein (e.g., 2a, 2e, and 4e) exhibited comparable in vivo efficacy to that achieved by the parent compounds, yet free of tail vein irritation and histamine induced toxicity in vivo.
Journal of Chromatography B, 2004
A review is presented on the CE analysis of colloidal/nano particles. Topics discussed include th... more A review is presented on the CE analysis of colloidal/nano particles. Topics discussed include the CE separation of polymeric, inorganic, microbial (i.e. viruses, bacteria, fungi, and whole cells), and sub-cellular particles (i.e. mitochondria and nuclei). Several of the encountered difficulties in analysis are presented as well as the methods employed to overcome them.
Analytical Chemistry, 2006
There has been growing interest in separations-based techniques for the identification and charac... more There has been growing interest in separations-based techniques for the identification and characterization of microorganisms because of the versatility, selectivity, sensitivity, and short analysis times of these methods. A related area of analysis that is scientifically and commercially important is the determination of the presence or complete absence of microbes (in essence, a test for sample sterility). In such a test, it is not of immediate importance to identify a particular microorganism, but rather, to know with a high degree of certainty whether any organism(s) is (are) present. Current regulations require culture-based tests that can take up to 2 weeks to complete. As a rapid alternative, capillary electrophoresis-based methods are examined. Experimental formats are developed that promote the consolidation of all cell types into a single zone (peak) which is separated from the electroosmotic flow front and any other interfering molecular constituents. This process can be accomplished using a segment of dilute cetyltrimethylammonium bromide, which serves to temporarily reverse the migration direction of the cells, and another segment of solution containing a "blocking agent", which serves to stop the cell migration and focus them into a narrow zone. Relatively wide-bore capillaries can be used to increase sample size. This approach appears to be effective for a broad spectrum of bacteria, and analyses times are less than 10 min.
The Medical journal of Australia
The virtual mentor : VM, 2003
... The case of Dr. Mike Ricardo and Mrs. Ashley Wills highlights the fact that practicing clinic... more ... The case of Dr. Mike Ricardo and Mrs. Ashley Wills highlights the fact that practicing clinicians continue to have difficulty integrating this standard into their everyday practice, and many IPV survivors do not readily disclose abuse, even when asked [1-2]. ...
Ear, nose, & throat journal, 2006
Forensic science, medicine, and pathology, 2012
The differential diagnosis of known entities associated with sudden unexpected death in infancy i... more The differential diagnosis of known entities associated with sudden unexpected death in infancy is ever expanding. Here we report the case of a 10-month-old infant boy whose clinical presentation mimicked that of the sudden infant death syndrome (SIDS). This presentation included the typical features of SIDS: sleep-related death; prone position upon discovery; and minor illness within 2 days of death. Nevertheless, neuropathologic examination revealed striking hippocampal asymmetry and microdysgenesis similar to that reported previously by us in toddlers with sleep-related sudden death. Hippocampal maldevelopment in the setting of sudden death in infants and toddlers is analogous to sudden unexpected death in epilepsy associated with temporal lobe pathology, and suggests a possible role for seizures in the terminal events leading to sudden death. This report serves to alert pediatric and forensic pathologists to hippocampal asymmetry and microdysgenesis in the differential diagnosis...
Pediatrics, 2014
Our understanding of the influence of maternal race/ethnicity and nativity and childhood autistic... more Our understanding of the influence of maternal race/ethnicity and nativity and childhood autistic disorder (AD) in African Americans/blacks, Asians, and Hispanics in the United States is limited. Phenotypic differences in the presentation of childhood AD in minority groups may indicate etiologic heterogeneity or different thresholds for diagnosis. We investigated whether the risk of developing AD and AD phenotypes differed according to maternal race/ethnicity and nativity. Children born in Los Angeles County with a primary AD diagnosis at ages 3 to 5 years during 1998-2009 were identified and linked to 1995-2006 California birth certificates (7540 children with AD from a cohort of 1,626,354 births). We identified a subgroup of children with AD and a secondary diagnosis of mental retardation and investigated heterogeneity in language and behavior. We found increased risks of being diagnosed with AD overall and specifically with comorbid mental retardation in children of foreign-born ...
Methods: Post-CABG patients who underwent a thera- peutic thoracentesis for a symptomatic pleural... more Methods: Post-CABG patients who underwent a thera- peutic thoracentesis for a symptomatic pleural effusion were included unless another explanation for the pleu- ral effusion was present. Results: During the study, 71 patients (mean age, 61 years) were identified; 49 were men and 22 were women. All patients underwent internal mammary artery graft- ing. Early effusions (,30 days after CABG) occurred
Gynecologic Oncology, 2003
ObjectiveThe goal of this study was to evaluate the tolerance and effectiveness of carboplatin re... more ObjectiveThe goal of this study was to evaluate the tolerance and effectiveness of carboplatin rechallenge using a prolonged desensitizing carboplatin infusion regimen in patients with clinically documented moderate-severe carboplatin hypersensitivity.
Hispanic Journal of Behavioral Sciences, 2004
A focus on youth development is the strongest means of prevention of problems faced by Latino you... more A focus on youth development is the strongest means of prevention of problems faced by Latino youths. Latino youths are the fastest growing segment of the U.S. population and have high rates of developmental deficits. However, youth development researchers have not attended to the inclusion and reporting of results for Latino youths. This study presents a challenge to youth development
Educational Measurement: Issues and Practice, 2005
Multiple-choice items are a mainstay of achievement testing. The need to adequately cover the con... more Multiple-choice items are a mainstay of achievement testing. The need to adequately cover the content domain to certify achievement proficiency by producing meaningful precise scores requires many high-quality items. More 3-option items can be administered than 4-or 5-option items per testing time while improving content coverage, without detrimental effects on psychometric quality of test scores. Researchers have endorsed 3-option items for over 80 years with empirical evidence-the results of which have been synthesized in an effort to unify this endorsement and encourage its adoption.
Applied Measurement in Education, 2002
Page 1. A Review of Multiple-Choice Item-Writing Guidelines for Classroom Assessment Thomas M. Ha... more Page 1. A Review of Multiple-Choice Item-Writing Guidelines for Classroom Assessment Thomas M. Haladyna College of Education Arizona State University West Steven M. Downing Department of Medical Education College of Medicine University of Illinois at Chicago ...
The Laryngoscope, 2009
Objectives/Hypothesis: To evaluate the surgical complications, auditory performance, and hearing ... more Objectives/Hypothesis: To evaluate the surgical complications, auditory performance, and hearing handicap following cochlear implantation in patients greater than 79 years of age.
Evaluating access to and delivery of mental health services for young children was a primary obje... more Evaluating access to and delivery of mental health services for young children was a primary objective of the national research demonstration program Starting Early Starting Smart (SESS). To present preliminary findings on family mental health and use of services in a community Head Start population at time of entry into a longitudinal study as part of the SESS program. Children enrolled for Head Start entry in 1998 and 1999 (N = 290; mean age, 4.3 years). Of these children, 52% were boys. Data on demographic factors, child and parent mental health, and service use were collected from the sample at baseline. Information was gathered from primary caregivers and teachers using standardized questionnaires and structured interviews. There was low concordance between parent and teacher ratings of child behavior. Factors predicting behavior problems in young children varied according to whether the parent or teacher rated the child as having behavior problems. Sex (male) and home environment were associated with teachers rating the child as having a behavior problem. Parent mental health problems and problems in the parent-child relationship were associated with parent ratings. Only home environment was associated with child-focused service utilization (services that help parents manage children's behavior). Demographic risk factors were not associated with child behavior problems or use of mental health services in this group of Head Start children. Findings suggest that children with behavioral problems have unmet mental health service needs. Interventions designed to address both parent mental health needs and sensitivity to the developmental needs of children may increase child-focused mental health service utilization.
Brain : a journal of neurology, 2015
Spinal muscular atrophy is a disorder of lower motor neurons, most commonly caused by recessive m... more Spinal muscular atrophy is a disorder of lower motor neurons, most commonly caused by recessive mutations in SMN1 on chromosome 5q. Cases without SMN1 mutations are subclassified according to phenotype. Spinal muscular atrophy, lower extremity-predominant, is characterized by lower limb muscle weakness and wasting, associated with reduced numbers of lumbar motor neurons and is caused by mutations in DYNC1H1, which encodes a microtubule motor protein in the dynein-dynactin complex and one of its cargo adaptors, BICD2. We have now identified 32 patients with BICD2 mutations from nine different families, providing detailed insights into the clinical phenotype and natural history of BICD2 disease. BICD2 spinal muscular atrophy, lower extremity predominant most commonly presents with delayed motor milestones and ankle contractures. Additional features at presentation include arthrogryposis and congenital dislocation of the hips. In all affected individuals, weakness and wasting is lower-...
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Papers by michael rodriguez