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Biomedical subjects

James Robinson

Publications and source records attributed to James Robinson.

At least 37 records · Page 2Linked to original sources
PubMed2005

Sequential pharmacotherapy for children with comorbid attention-deficit/hyperactivity and anxiety disorders.

OBJECTIVE: Attention-deficit/hyperactivity disorder (ADHD) is often accompanied by clinically significant anxiety, but few empirical data guide treatment of children meeting full DSM-IV criteria for ADHD and anxiety disorders (ADHD/ANX). This study examined the efficacy of sequential pharmacotherapy for ADHD/ANX children. METHOD: Children, age 6 to 17 years, with ADHD/ANX were titrated to optimal methylphenidate dose and assessed along with children who entered the study on a previously optimized stimulant. Children with improved ADHD who remained anxious were randomly assigned to 8 weeks of double-blind stimulant + fluvoxamine (STIM/FLV) or stimulant + placebo (STIM/PL). Primary efficacy measures were the Swanson, Nolan, Atkins, and Pelham IV Parent and Teacher Rating Scale ADHD score and the Pediatric Anxiety Rating Scale total score. ADHD, ANX, and overall Clinical Global Impressions-Improvement scores were also obtained. RESULTS: Of the 32 medication-naive children openly treated with methylphenidate, 26 (81%) improved as to ADHD. Twenty-five children entered the randomized trial. Intent-to-treat analysis indicated no differences between the STIM/FLV (n = 15) and STIM/PL groups on the Pediatric Anxiety Rating Scale or Clinical Global Impressions-Improvement-defined responder rate. Medications in both arms were well tolerated. CONCLUSIONS: Children with ADHD/ANX have a response rate to stimulants for ADHD that is comparable with that of children with general ADHD. The benefit of adding FLV to stimulants for ANX remains unproven.

Adolescent↗
PubMed2005

A placebo-controlled screening trial of celecoxib for the treatment of cocaine dependence.

AIMS: To conduct a medication screening trial study on the efficacy of celecoxib versus placebo for the treatment of cocaine dependence. DESIGN: A modified blinded, parallel group study in an outpatient setting using the Cocaine Rapid Efficacy and Safety Trials (CREST) study design. SETTING: The study was performed at the New York Medications Development Research Unit (MDRU). PARTICIPANTS: All participants met Diagnostic and Statistical Manual version IV (DSM-IV) criteria for cocaine dependence and provided at least two urine samples positive for benzoylecgonine (BE) during the 2-week screening period. Twenty-three participants were enrolled in the treatment phase of the study. INTERVENTION: After a 2-week screening period, subjects were assigned randomly to receive either celebrex (200 mg/day) or placebo for an 8-week treatment period. All subjects also received individual cognitive behavioral counseling during treatment. MEASUREMENTS: Primary outcome measures included quantitative urine benzoylecgonine (BE) levels, self-report of drug use and global impression scores. Secondary outcomes included cocaine craving, study retention and related psychosocial measures. Safety measures included adverse event monitoring, vital signs and extrapyramidal side-effects tests. RESULTS: Study retention was similar across both treatment groups and safety measures indicated that celecoxib was moderately tolerated. Cocaine use, as measured by self-report and urine BE levels at end of treatment, indicated weaker improvement in the celecoxib group. Reductions in the intensity of cocaine craving were also weaker in the celecoxib group. Cocaine abstinence rates, global impression scores and all other related psychometric measures did not differ significantly between treatment groups. CONCLUSION: This study does not support the effectiveness of celecoxib for the treatment of cocaine dependence.

Adolescent↗
PubMed2005

A placebo-controlled screening trial of olanzapine, valproate, and coenzyme Q10/L-carnitine for the treatment of cocaine dependence.

AIMS: To conduct a medication screening trial on the efficacy of olanzapine, valproate or coenzyme Q10/L-carnitine combination versus placebo for the treatment of cocaine dependence. DESIGN: A four-arm, modified blinded, parallel group study in an out-patient setting using the Cocaine Rapid Efficacy and Safety Trials (CREST) study design. SETTING: The study was performed at the New York Medications Development Research Unit (MDRU). PARTICIPANTS: All participants met Diagnostic and Statistical Manual version IV (DSM-IV) criteria for cocaine dependence and provided at least two urine samples positive for benzoylecgonine (BE) during the 2-week screening period. Sixty-eight participants were enrolled with 39 completing the study. INTERVENTION: After a 2-week screening period, 68 subjects were assigned randomly to receive either olanzapine (10 mg/day), valproate (1500 mg/day), coenzyme Q10 (200 mg/day) and L-carnitine (500 mg/day) combination or placebo for an 8-week treatment period. All subjects also received individual cognitive behavioral counseling during treatment. MEASUREMENTS: Primary outcome measures included quantitative urine benzoylecgonine (BE) levels, self-report of drug use, and global impression scores. Secondary outcomes included cocaine craving, study retention and related psychosocial measures. Safety measures included adverse event monitoring, vital signs, and extrapyramidal side-effects tests. RESULTS: Study retention was similar across all treatment groups, and all groups showed improvement across most measures of treatment efficacy over the duration of the study. None of the study medications, however, were superior to placebo on any of the primary or secondary outcome measures. Cocaine use, as measured by urine BE levels and self-report, was not significantly lower than placebo in any of the drug treatment groups. All study medications were equally well tolerated, and few medication side effects were observed. CONCLUSION: This pilot study does not support the effectiveness of olanzapine, valproate or coenzyme Q10/L-carnitine combination for the treatment of cocaine dependence.

Adolescent↗
PubMed2005

Functional mimicry of a human immunodeficiency virus type 1 coreceptor by a neutralizing monoclonal antibody.

Interaction of the human immunodeficiency virus type 1 (HIV-1) gp120 envelope glycoprotein with the primary receptor, CD4, promotes binding to a chemokine receptor, either CCR5 or CXCR4. The chemokine receptor-binding site on gp120 elicits CD4-induced (CD4i) antibodies in some HIV-1-infected individuals. Like CCR5 itself, the CD4i antibody 412d exhibits a preference for CCR5-using HIV-1 strains and utilizes sulfated tyrosines to achieve binding to gp120. Here, we show that 412d binding requires the gp120 beta19 strand and the base of the V3 loop, elements that are important for the binding of the CCR5 N terminus. Two gp120 residues in the V3 loop base determined 412d preference for CCR5-using HIV-1 strains. A chimeric molecule in which the 412d heavy-chain third complementarity-determining loop sequence replaces the CCR5 N terminus functioned as an efficient second receptor, selectively supporting the entry of CCR5-using HIV-1 strains. Sulfation of N-terminal tyrosines contributed to the function of this chimeric receptor. These results emphasize the close mimicry of the CCR5 N terminus by the gp120-interactive region of a naturally elicited CD4i antibody.

Amino Acid Sequence↗
PubMed2005

A placebo controlled, double-blind study of mecamylamine treatment for cocaine dependence in patients enrolled in an opiate replacement program.

A placebo controlled, double-blind trial of mecamylamine treatment of cocaine dependence was performed in methadone or LAAM maintained subjects who met DSM-IV criteria for cocaine dependence. After an eight-week placebo run-in screening period, 35 subjects were randomly assigned to receive either mecamylamine (6 mg/day) or placebo transdermal patches for a 16-week treatment period. Outcome measures included quantitative urine benzoylecognine (BE) levels, self-report of cocaine use, cocaine craving, global impression scores, mood, retention, and safety. Mecamylamine was well tolerated, and study retention did not differ by treatment group. Evidence for cocaine use, based on urine BE levels and cocaine abstinence rates, did not differ by treatment group. Self reported cocaine use, cocaine craving, and global impression scores showed moderate improvement in both groups, with a significantly greater reduction in cocaine craving (p < 0.05) and self-rated severity of cocaine dependence (p < 0.05) in the placebo group. This pilot study does not support the effectiveness of mecamylamine for the treatment of cocaine dependence in methadone or LAAM maintained patients.

Administration, Cutaneous↗
PubMed2005

Characterizing anti-HIV monoclonal antibodies and immune sera by defining the mechanism of neutralization.

Understanding the nature of neutralization may provide information for crafting improvements in HIV vaccines. Using JR-FL as a prototype primary pseudovirus, we first investigated anti-HIV monoclonal antibodies (mAbs) in several neutralization formats designed to elucidate the timing of neutralization. MAb b12 was most effective before receptor binding, 2G12 neutralized effectively even after CD4 binding, and X5 and a V3 loop mAb (LE311) were inactive in a standard format but were induced by sCD4. Consistent with this latter finding, native PAGE indicated that X5 and V3 mAb binding to Envelope trimers was dependent on sCD4 binding. In contrast, 2F5 and 4E10 were active even post-CD4/CCR5 engagement. We next analyzed the neutralization mechanism of a panel of HIV+ donor plasmas of various potencies. All mediated high levels of post-CD4 neutralization that was not associated with activity in the standard format. None, however, neutralized effectively in the post-CD4/CCR5 format, suggesting that 2F5/4E10-like Abs were absent or at low concentrations. Finally, we analyzed a non-neutralizing plasma spiked with mAbs b12, 2G12 or 2F5, which resulted in increases in neutralization titers consistent with the activities of the mAbs. We conclude that these methods, together with other mapping approaches, may provide a better understanding of neutralization that could be useful in vaccine research.

AIDS Vaccines↗
PubMed2004

Seroprevalence of simian immunodeficiency virus in wild and captive born Sykes' monkeys (Cercopithecus mitis) in Kenya.

BACKGROUND: The Sykes' monkey and related forms (Cercopithecus mitis) make up an abundant, widespread and morphologically diverse species complex in eastern Africa that naturally harbors a distinct simian immunodeficiency virus (SIVsyk). We carried out a retrospective serological survey of SIV infection from both wild and captive Sykes' monkeys from Kenya. We compared two commercially available, cross-reactive ELISA tests using HIV antigens with a novel SIVsyk antigen-specific Western blot assay and analyzed the data by origin, subspecies, age and sex. RESULTS: The SIVsyk antigen-specific Western blot assay detected more serum samples as positive than either of the cross-reactive ELISA assays. Using this assay, we found that seroprevalence is higher than previously reported, but extremely variable in wild populations (from 0.0 to 90.9%). Females were infected more often than males in both wild and captive populations. Seropositive infants were common. However, no seropositive juveniles were identified. CONCLUSION: We have developed a specific and sensitive Western blot assay for anti-SIVsyk antibody detection. Sykes' monkeys are commonly infected with SIVsyk, but with extremely variable prevalence in the wild. Higher infection prevalence in females suggests predominantly sexual transmission. High infection prevalence in infants, but none in juveniles, suggests maternal antibodies, but little or no vertical transmission.

Animals↗
PubMed2004

Structural basis of tyrosine sulfation and VH-gene usage in antibodies that recognize the HIV type 1 coreceptor-binding site on gp120.

The conserved surface of the HIV-1 gp120 envelope glycoprotein that binds to the HIV-1 coreceptor is protected from humoral recognition by multiple layers of camouflage. Here we present sequence and genomic analyses for 12 antibodies that pierce these defenses and determine the crystal structures of 5. The data reveal mechanisms and atomic-level details for three unusual immune features: posttranslational mimicry of coreceptor by tyrosine sulfation of antibody, an alternative molecular mechanism controlling such sulfation, and highly selective V(H)-gene usage. When confronted by extraordinary viral defenses, the immune system unveils novel adaptive capabilities, with tyrosine sulfation enhancing the vocabulary of antigen recognition.

Acquired Immunodeficiency Syndrome↗
PubMed2004

An inducible HIV type 1 gp41 HR-2 peptide-binding site on HIV type 1 envelope gp120.

Synthetic peptides of sequences within the HIV-1 gp41 heptad repeat-regions (HR-1 and HR-2) can effectively inhibit cell fusion and viral entry. DP178 (T-20), an HR-2 peptide, acts by inhibiting the association between HR-1 and HR-2, thereby interfering with HIV-1 fusion and viral entry. HR-2 peptide binding is predicted to be an important indicator of the presence of Env gp41 fusion intermediate conformation. A stabilized HR-2/Env conjugate might be an HIV-1 vaccine candidate and have the potential for inducing antibodies against transiently exposed epitopes on HIV-1 Env. To explore the possibility of design of HR-2 stabilized-HIV-1 immunogens, we studied the ability of HIV-1 Env to bind to HR-2 peptides. Using surface plasmon resonance (SPR)-binding assays and precipitation of soluble Env gp120 proteins with HR-2 peptide DP178, we have found that there is an HR-2 peptide-binding site on soluble HIV-1 recombinant gp120. Binding of DP178 was induced by sCD4 and by the anti-gp120 human mAb A32. The induction of DP178 binding was inhibited > 80% by the HIV-1 coreceptor-binding site mAb 17b. Binding of DP178 to gp120 was also inhibited by gp120 C4 peptides with sequences that are centrally located within the HIV-1 coreceptor-binding site. Thus, in addition to interactions with the gp41 HR-1 region, the fusion inhibitor peptide DP178 binds to triggered soluble HIV-1 recombinant gp120 following its interaction with sCD4 or CD4 mimic mAb A32. This may prove to be an important consideration when designing an HIV vaccine that utilizes constrained HIV Env proteins.

CD4 Antigens↗
PubMed2004

Immunogenicity of constrained monoclonal antibody A32-human immunodeficiency virus (HIV) Env gp120 complexes compared to that of recombinant HIV type 1 gp120 envelope glycoproteins.

One strategy for the generation of broadly reactive neutralizing antibodies (NA) against human immunodeficiency virus type 1 (HIV-1) primary isolates is to use immunogens that have constrained HIV-1 envelope gp120 conformations reflective of triggered envelope on the surface of virions. A major change in gp120 following binding to CD4 is the enhanced exposure of the CCR5 binding site. One inducer of CCR5 binding site epitopes on gp120 is the human anti-gp120 monoclonal antibody, A32. We have made cross-linked A32-rgp120(89.6) and A32-rgp120(BaL) complexes and have compared their immunogenicities to those of uncomplexed recombinant gp120(BaL) (rgp120(BaL)) and rgp120(89.6). A32-rgp120(89.6) and A32-rgp120(BaL) complexes had stable induced CCR5 binding site expression compared to that of uncomplexed rgp120s. However, the A32-rgp120 complexes had similar capacities in guinea pigs for induction of NA against HIV-1 primary isolates versus that of rgp120 alone. A32-rgp120(89.6) induced antibodies that neutralized 6 out of 11 HIV-1 isolates, while rgp120(89.6) alone induced antibodies that neutralized 4 out of 11 HIV-1 isolates. A32-rgp120(BaL) complexes induced antibodies that neutralized 4 out of 14 HIV-1 isolates while, surprisingly, non-cross-linked rgp120(BaL) induced antibodies that neutralized 9 out of 14 (64%) HIV-1 isolates. Thus, stable enhanced expression of the coreceptor binding site on constrained gp120 is not sufficient for inducing broadly neutralizing anti-HIV-1 NA. Moreover, the ability of HIV-1 rgp120(BaL) to induce antibodies that neutralized approximately 60% of subtype B HIV-1 isolates warrants consideration of using HIV-1 BaL as a starting point for immunogen design for subtype B HIV-1 experimental immunogens.

Animals↗
PubMed2004

Relationship between antipsychotic medication treatment and new cases of diabetes among psychiatric inpatients.

OBJECTIVE: This study examined data on patients with serious and persistent mental illness in a large state hospital system to determine whether patients who took second-generation antipsychotics were more likely to develop diabetes mellitus than patients who took first-generation antipsychotics. METHODS: A case-control study design was used. A new prescription of an antidiabetic medication was used to identify new cases of diabetes mellitus. Odds ratios were calculated for exposure to second-generation antipsychotics (clozapine, risperidone, olanzapine, quetiapine, and multiple second-generation antipsychotics) compared with exposure to first-generation antipsychotics. Cases and controls were identified by using a database that contained drug prescription information from the inpatient facilities that were operated by the New York State Office of Mental Health. Data from January 1, 2000, to December 31, 2002, were examined. Among 13,611 unique patients who received antipsychotics, 8,461 met entry criteria of being hospitalized for at least 60 days and not having an antidiabetic medication prescribed in the past. A total of 181 of these inpatients received prescriptions for an antidiabetic medication at least 30 days after their admission. Eight controls (N=1,448) for each case (N=181) were matched by calendar year, length of observation period, race, age group, and diagnosis, giving a total sample of 1,629 patients. RESULTS: Statistically significant elevations in risk were seen among patients who received more than one second-generation antipsychotic or clozapine or quetiapine, compared with patients who received first-generation antipsychotics alone. Although not statistically significant, odds ratios for olanzapine and risperidone were also elevated. Conditional logistic regression adjusting for gender and age did not change the results. CONCLUSIONS: Exposure to multiple second-generation antipsychotics or clozapine or quetiapine significantly increased the risk of treatment-emergent diabetes mellitus.

Adult↗
PubMed2003

IMGT/HLA and IMGT/MHC: sequence databases for the study of the major histocompatibility complex.

The IMGT/HLA database (http://www.ebi.ac.uk/imgt/hla) has provided a centralized repository for the sequences of the alleles named by the WHO Nomenclature Committee for Factors of the HLA System for the past four years. Since its initial release the database has grown and is the primary source of information for the study of sequences of the human major histocompatibilty complex. The initial release of the database contained a limited number of tools. As a result of feedback from our users and developments in HLA we have been able to provide new tools and facilities. The HLA sequences have also been extended to include intron sequences and the 3' and 5' untranslated regions in the alignments and also the inclusion of new genes such as MICA. The IMGT/MHC database (http://www.ebi.ac.uk/imgt/mhc) was released in March 2002 to provide a similar resource for other species. The first release of IMGT/MHC contains the sequences of non-human primates (apes, new and old world monkeys), canines and feline sequences. Further species will be added shortly and the database aims to become the primary source of MHC data for non-human sequences.

Alleles↗
PubMed2003

Molecular effects of volume expansion on the renal sodium phosphate cotransporter.

BACKGROUND: Volume Expansion (VE) results in both natriuresis and a phosphaturia. In previous studies, Sprague-Dawley rats were infused with a modified saline solution. The expansion procedure resulted in a 70% increase in the phosphorylation of a 72 kDa proximal tubular brush border membrane (BBM) protein. In recent experiments, Sprague-Dawley rats were subjected to the same short term VE. For both control and VE animals, brush border membrane vesicles (BBMV) were obtained. METHODS AND RESULTS: Mass spectrometry of 3 proteins in the size range of our phosphoprotein resulted in the identification of ezrin/villin2, moesin, and PDZ domain-containing 1 (PDZ-dc1). Diphor-1 (currently renamed PDZ-dc1) is involved in regulation of the type II Na/Pi cotransporter. Ezrin and moesin are membrane-cytoskeletal linking proteins that are involved in the regulation of the sodium-hydrogen exchanger (NHE3) via interactions with another PDZ protein identified as sodium-hydrogen exchanger regulatory factor (EBP50, NHERF). Ezrin, moesin, and PDZ-dc1 protein levels were not increased following short term VE. Two-dimensional electrophoresis of our phosphorylated BBM proteins, followed by MALDI/MS analysis resulted in the identification of a protein mixture containing ezrin/moesin, alkaline phosphatase, and an unknown protein. Based on Western and immunoprecipitation data for ezrin, moesin, and PDZ-dc1 we believe that it is unlikely that our phosphoprotein is any of these 3 proteins. Parallels between NHE3 regulation (through EBP50/ERM proteins) and Na/Pi cotransporter regulation (through PDZ-dc1/ERM proteins) may be drawn. CONCLUSION: These changes in proximal Na/Pi cotransport may involve a signal transduction cascade including PDZ-dc1, ezrin, moesin, our phosphoprotein, and possibly other proteins.

Amino Acid Sequence↗
PubMed2003

Searching for moderators and mediators of pharmacological treatment effects in children and adolescents with anxiety disorders.

OBJECTIVE: To examine whether age, gender, ethnicity, type of anxiety disorder, severity of illness, comorbidity, intellectual level, family income, or parental education may function as moderators and whether treatment adherence, medication dose, adverse events, or blinded rater's guess of treatment assignment may function as mediators of pharmacological treatment effect in children and adolescents with anxiety disorders. METHOD: The database of a recently reported double-blind placebo-controlled trial of fluvoxamine in 128 youths was analyzed. With a mixed-model random-effects regression analysis of the Pediatric Anxiety Rating Scale total score, moderators and mediators were searched by testing for a three-way interaction (strata by treatment by time). A two-way interaction (strata by time) identified predictors of treatment outcome. RESULTS: No significant moderators of efficacy were identified, except for lower baseline depression scores, based on parent's (but not child's) report, being associated with greater improvement (p < .001). Patients with social phobia (p < .05) and greater severity of illness (p < .001) were less likely to improve, independently of treatment assignment. Blinded rater's guess of treatment assignment acted as a possible mediator (p < .001), but improvement was attributed to fluvoxamine, regardless of actual treatment assignment. Treatment adherence tended to be associated (p = .05) with improvement. CONCLUSIONS: In this exploratory study, patient demographics, illness characteristics, family income, and parental education did not function as moderators of treatment effect. Social phobia and severity of illness predicted less favorable outcome. Attribution analyses indicated that study blindness remained intact. The presence of concomitant depressive symptoms deserves attention in future treatment studies of anxious children.

Adolescent↗
PubMed2003

How can we improve the assessment of safety in child and adolescent psychopharmacology?

OBJECTIVE: To identify approaches to improving methods for assessing tolerability and safety of psychotropic medications in children and adolescents. METHOD: Strengths and limitations of current methodology were reviewed and possible alternatives examined. RESULTS: Research on the validity of safety evaluation has been extremely limited. No evidence-based "gold standard" exists. Clinical trials remain the best design to establish causality, but sample size limitations prevent the detection of infrequent, though serious, adverse events. Other designs, such as cohort and case-control studies, and approaches, such as mining of large databases, must be considered. CONCLUSION: The current lack of methodological standardization across studies prevents generalizations and meta-analyses. Because the issues relevant to drug safety are diverse, a variety of methodological approaches and instruments are needed. It is, however, possible to adopt standard basic definitions of adverse events, degree of severity, ascertainment methods, and recording procedures, as a common "core," to which more specific assessment instruments can be added. Systematic empirical testing and validation of safety methodology is needed.

Adolescent↗
PubMed2003

Review of safety assessment methods used in pediatric psychopharmacology.

OBJECTIVE: Elicitation is an essential and critical step in ascertaining adverse events (AEs). This report reviews elicitation methods used in published clinical trials of psychopharmacological agents in children. METHOD: Pediatric psychopharmacology reports were reviewed for safety methods in the Medline database. Studies were included if they were published 1980 or later, provided data on AEs, and described the ascertainment methodology used for determining them. RESULTS: A review of 196 pediatric psychopharmacology articles depicting safety assessments in clinical studies over the past 22 years revealed that there was no common method used for eliciting or reporting AE data. CONCLUSION: The current inconsistency in safety data ascertainment is a major limitation that likely impairs the ability to promptly and accurately identify drug-induced AEs. Research on how best to standardize safety methods should be considered a priority in pediatric psychopharmacology.

Adolescent↗
PubMed2003

Developing methodologies for monitoring long-term safety of psychotropic medications in children: report on the NIMH conference, September 25, 2000.

OBJECTIVE: To improve the methods for long-term assessment of drug-associated side effects and advance knowledge of the safety profile of psychotropic medications in children and adolescents. METHOD: A multidisciplinary, interactive workshop was hosted by the National Institute of Mental Health (NIMH) and the Research Units on Pediatric Psychopharmacology network. Participants were experts in child and adolescent psychiatry, psychopharmacology, pharmacoepidemiology, and statistics from academia, the pharmaceutical industry, the Food and Drug Administration (FDA), and the NIMH. Evaluation of drug safety was examined from five perspectives: research design and methods, industry, regulatory requirements, bioethics, and practice settings. For each of these areas, special emphasis was placed on identifying barriers and generating solutions. RESULTS: A major obstacle is the lack of standardization of the methods used for collecting safety data. The limitations of both randomized clinical trials and passive postmarketing surveillance in assessing long-term safety were recognized. The need to consider alternative approaches, such as registries and trend analysis of population-based databases, was highlighted. Recommendations were proposed together with possible approaches to implementation. CONCLUSIONS: A concerted effort by academic researchers, industry, FDA, practitioners, and NIMH is needed to standardize methods and lay the foundations for systematic research on the long-term safety of psychotropic medications in children.

Adolescent↗