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Biomedical subjects

J B Prince

Publications and source records attributed to J B Prince.

17 recordsLinked to original sources
PubMed2000

A controlled study of nortriptyline in children and adolescents with attention deficit hyperactivity disorder.

OBJECTIVES: To study the efficacy and tolerability of nortriptyline (NT) in the treatment of pediatric attention deficit hyperactivity disorder (ADHD). METHODOLOGY: Subjects were outpatient children and adolescents with ADHD ascertained from clinical referrals. Subjects were enrolled in a 6-week open study in which NT was titrated to 2 mg/kg/day as tolerated over 2 weeks. Using either a 30 % reduction in the ADHD rating scale or a score of 1 or 2 on the Clinical Global Impression (CGI) scale for ADHD improvement, responders to treatment were then randomized into a 3-week, controlled discontinuation phase. During this phase, subjects either continued on their current dose of NT or were tapered to placebo under double-blind conditions. Subjects were monitored for symptoms of ADHD, oppositionality, anxiety, and depression. RESULTS: Of the 35 subjects enrolled in the study, 32 completed the open phase and 23 completed the discontinuation phase. The mean dose of NT was 80 mg (1.8 mg/kg/day), resulting in a serum level of 81 ng/ml. At the conclusion of the open 6-week study, NT was related to a significant reduction in ADHD (p < 0.001) and oppositional symptoms (p < 0.001). At the conclusion of the discontinuation phase, the 12 subjects randomized to NT had significantly lower scores on the DSM-IV ADHD symptom checklist than those 11 subjects randomized to placebo (31 versus 21; t = 2.2; p < 0.04). No significant adverse events were observed, and children were noted to have weight gain during the trial. CONCLUSIONS: These data suggest that NT is effective in reducing symptoms not only of ADHD but also of oppositionality. This group of children and adolescents tolerated robust dosing of NT well, with few clinical or cardiovascular adverse events.

Adolescent↗
PubMed2000

Pemoline treatment of adolescents with attention deficit hyperactivity disorder: a short-term controlled trial.

BACKGROUND: Despite the increased recognition of attention deficit hyperactivity disorder (ADHD) in adolescents, few controlled studies have assessed treatments for this age group. Adolescent issues, such as embarrassment at receiving medication at school and experimentation with abusable substances, have accelerated efforts to find effective, well-tolerated treatments beyond traditional stimulants. Pemoline has been found effective for treating both children and adults with ADHD but has not been evaluated in adolescents with ADHD. METHODS: Twenty-one adolescents (mean age 14 years old) diagnosed with ADHD by structured and clinical interviews participated in a 10-week, double-blind crossover design study of pemoline. Dosing was optimized with robust doses up to 3 mg/kg/day in one to two doses. Clinical evaluations of ADHD, depression, anxiety, and oppositional defiant disorder (ODD) symptoms were assessed weekly. RESULTS: Adolescents with ADHD exhibited a marked response to pemoline treatment relative to placebo on the ADHD rating scale (p = 0.001), with an average reduction of 3.02 points per week of treatment. Sixty percent of adolescents responded to pemoline, compared to 11% treated with placebo. This response was independent of gender or lifetime psychiatric comorbidity. Pemoline was well tolerated, with patients averaging 2.88 mg/kg/day in two doses per day, with a mean dose at end of follow-up of 181.1 mg (SD 45.6, range 112.5-262.5 mg). Side effects were mild, and no adverse hepatic events occurred. CONCLUSIONS: These findings resemble those reported in children and adults with ADHD. This trial suggests pemoline is well tolerated and effective in adolescents and may be a particularly useful ADHD treatment for adolescents.

Adolescent↗
PubMed2000

Adjunctive donepezil in attention deficit hyperactivity disorder youth: case series.

Despite well-documented improvement in attention deficit hyperactivity disorder (ADHD) in youths with the available single and combined pharmacologic agents, a number of youths remain with residual symptomatology causing impairment in multiple domains. Recent work has suggested a potential cognitive-enhancing role of cholinergic agents in ADHD. We describe five cases of ADHD youths aged 8-17 years being treated for ADHD with the acetylcholinesterase inhibitor donepezil (Aricept), all of whom demonstrated improvement.

Adolescent↗
PubMed1996

Clonidine for sleep disturbances associated with attention-deficit hyperactivity disorder: a systematic chart review of 62 cases.

OBJECTIVE: Children and adolescents with attention-deficit hyperactivity disorder (ADHD), with or without psychostimulant treatment, frequently suffer from sleep disturbances. This report evaluates the use of clonidine in the treatment of sleep disturbances associated with ADHD. METHOD: A systematic search of a computerized database in an outpatient pediatric psychopharmacology unit of patients treated with clonidine for ADHD-associated sleep disturbances (N = 62; 42 children and 20 adolescents) was performed. Patients were rated retrospectively about the type and severity of sleep disturbances at baseline and after treatment with clonidine. RESULTS: A majority of patients (85%) treated with clonidine for ADHD-associated sleep disturbances were considered to be much to very much improved by the National Institute of Mental Health global assessment of improvement (sleep). Nighttime clonidine doses ranged from 50 to 800 micrograms (mean +/- SEM; 157 +/- 14 micrograms), and subjects received clonidine for 35.5 +/- 3.5 months. There was no association between response and age group, gender, comorbidity, or concurrent pharmacotherapy. Children and adolescents with ADHD with baseline, medicine-induced, or medicine-exacerbated sleep disturbances responded equally well to clonidine treatment. Mild adverse effects were reported in 19 subjects (31%). CONCLUSIONS: These findings suggest that clonidine may be an effective agent for sleep disturbances associated with ADHD, or its treatment, and warrant further controlled investigations.

Adolescent↗
PubMed1992

Expression, characterization, and serologic reactivity of recombinant surface antigen P22 of Toxoplasma gondii.

The utility of recombinant Toxoplasma gondii surface antigen P22 for the detection of specific T. gondii antibodies in human sera was evaluated. Polymerase chain reaction was used to produce a 438-bp fragment of the P22 gene; the fragment corresponded to the amino acids predicted to be in the processed, native antigen. The fragment was subcloned into pGEX-2T and was expressed in Escherichia coli as a glutathione-S-transferase (GST) fusion protein. The fusion protein was purified in a soluble form and was found to be recognized by sera from infected individuals in immunoblots and an enzyme-linked immunosorbent assay. Immunoglobulin G antibodies in sera from 31 acutely infected patients in general reacted more strongly to the fusion protein than did those in sera from 31 patients with the chronic infection. None of the sera from a panel of 26 seronegative controls reacted with the fusion protein was separated from the GST partner by cleavage with thrombin, it retained its immunoreactivity and its electrophoretic mobility in polyacrylamide gels was found to be similar to that of native P22. By a modification of the published method for purification of the foreign polypeptide from the GST carrier, the recombinant P22 was readily purified to homogeneity by thrombin cleavage of the fusion protein while it was adsorbed to glutathione agarose.

Animals↗
PubMed1990

Cloning, expression, and cDNA sequence of surface antigen P22 from Toxoplasma gondii.

Immunoblot, immunofluorescence, and complement-mediated cytolytic assays revealed that two new monoclonal antibodies raised against a membrane-enriched fraction of Toxoplasma gondii tachyzoites recognize protein P22 on the surface of the parasite. Using these monoclonal antibodies to screen a cDNA expression library in lambda gt11, several clones expressing recombinant fusion proteins were isolated. Subsequent screening of the library with a synthetic oligonucleotide derived from the 5' end of one of these cDNAs permitted the isolation of additional nonexpressing clones containing the entire translated sequence. Blots of parasite RNA and DNA suggested that the corresponding gene occurs as a single copy in the tachyzoite genome. The amino acid sequence deduced from the composite cDNA indicates a primary translation product with a theoretical molecular weight of 18,959. As expected for surface protein P22, the putative polypeptide contains a predicted N-terminal signal sequence and a C-terminal hydrophobic region characteristic of proteins attached to the membrane by a glycophospholipid anchor. Recombinant fusion proteins produced by the expressing clones were recognized on immunoblots by IgG antibodies in the sera of humans with acute and chronic T. gondii infection. Antibodies selected by the fusion protein reacted predominantly with a 22-kDa antigen on immunoblots of parasite lysate.

Amino Acid Sequence↗
PubMed1989

Cloning of cDNAs encoding a 28 kilodalton antigen of Toxoplasma gondii.

By screening cDNA libraries in lambda gt11 with antibodies raised against the previously described protective F3G3 antigen of Toxoplasma gondii, and subsequently screening with nucleic acid probes, we have isolated cDNA clones that encode a 28 kDa antigen of T. gondii that is likely one of the two antigenic components of the F3G3 antigen. The gene apparently exists as a single copy in the tachyzoite haploid genome of the three strains of T. gondii examined. Northern blot analyses revealed that the cDNAs hybridize with a major T. gondii RNA species of 1.1 kb. Together the cDNAs encompass 1051 bp of cDNA sequence containing an open reading frame with the capacity to encode a 28 kDa protein. Antibodies that were affinity purified using recombinant fusion proteins produced by two of the clones reacted on protein blots of whole T. gondii lysate with a single antigen having an apparent molecular mass of 28 kDa. Both recombinant fusion proteins reacted with IgG antibodies in sera of mice and humans infected with T. gondii and therefore might be useful for the development of diagnostic assays for T. gondii infection.

Amino Acid Sequence↗
PubMed1988

Toxoplasma peritonitis in a patient with acquired immunodeficiency syndrome.

Toxoplasma gondii was identified in a stained slide preparation of, and isolated from, peritoneal fluid specimens obtained from a patient with the acquired immunodeficiency syndrome (AIDS). At the time of admission to the hospital, the patient's serologic tests were positive for Toxoplasma. Toxoplasma was isolated from samples of the patient's blood by mouse inoculation. Findings of newly developed methods for diagnosis of the presence of T gondii in body fluids by assay for Toxoplasma-specific antigen and by use of a DNA probe were positive.

Acquired Immunodeficiency Syndrome↗
PubMed1985

Cell free synthesis of Toxoplasma gondii antigens.

Functionally active poly(A)-containing mRNA was isolated from tachyzoites of the RH strain of Toxoplasma gondii. The T. gondii mRNA was capable of directing the synthesis of proteins in a wheat germ in vitro translation system, but not in a cell free system derived from rabbit reticulocyte lysate. Efficient translation in the wheat germ system required spermine and exogenous tRNA. Amino acid incorporation was maximal at 110 mM K+ and 1.8 mM Mg2+. Tachyzoite antigens synthesized in vitro were immunoprecipitated with T. gondii antibodies from rabbits, mice and humans. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis of immunoprecipitated polypeptides yielded patterns that differed according to antibody source, but all T. gondii antibody preparations reacted with a translation product with an apparent molecular weight of 24 000.

Animals↗
PubMed1985

Evidence for functional interaction between domains II and V of 23S ribosomal RNA from an erythromycin-resistant mutant.

A mutation affording low levels of erythromycin resistance has been obtained by in vitro hydroxylamine mutagenesis of a cloned ribosomal RNA operon from Escherichia coli. The site of the mutational event responsible for antibiotic resistance was localized to the gene region encoding domain II of 23S rRNA by replacement of restriction fragments in the wild-type plasmid by corresponding fragments from the mutant plasmid. DNA sequencing showed that positions 1219-1230 of the 23S rRNA gene are deleted in the mutant. Since all previously characterized rRNA mutations conferring resistance to erythromycin show changes exclusively in domain V, our present findings provide direct evidence for functional interaction between domains II and V of 23S rRNA.

Ampicillin↗
PubMed1982

Covalent crosslinking of tRNA1Val to 16S RNA at the ribosomal P site: identification of crosslinked residues.

N-Acetylvalyl-tRNA1Val (AcVal-tRNA1Val) was bound to the P site of uniformly 32P-labeled 70S ribosomes from Escherichia coli and crosslinked to 16S RNA in the 30S ribosomal subunit by irradiation with light of 300-400 nm. To identify the crosslinked nucleotide in 16S RNA. AcVal-tRNA1Val-16S [32P]RNA was digested completely with RNase T1 and the band containing the covalently attached oligonucleotides from tRNA and rRNA was isolated by polyacrylamide gel electrophoresis. The crosslinked oligonucleotide, and the 32P-labeled rRNA moiety released from it by photoreversal of the crosslink at 254 nm, were then analyzed by secondary hydrolysis with pancreatic RNase A and RNase U2. The oligonucleotide derived from 16S RNA was found to be the evolutionarily conserved sequence, U-A-C-A-C-A-C-C-G1401, and the nucleotide crosslinked to tRNA1Val, C1400. The identity of the covalently attached residue in the tRNA was established by using AcVal-tRNA1Val-16S RNA prepared from unlabeled ribosomes. This complex was digested to completion with RNase T1 and the resulting RNA fragments were labeled at the 3' end with [5'-32P]pCp. The crosslinked T1 oligonucleotide isolated from the mixture yielded one major end-labeled component upon photoreversal. Chemical sequence analysis demonstrated that this product was derived from the anticodon-containing pentadecanucleotide of tRNA1Val, C-A-C-C-U-C-C-C-U-cmo5U-A-C-m6A-A-G39(cmo5U, 5-carboxymethoxyuridine). A similar study of the crosslinked oligonucleotide revealed that the residue covalently bound to 16S was cmo5U34, the 5' or wobble base of the anticodon. The adduct is believed to result from formation of a cyclobutane dimer between cmo5U34 of tRNA1Val and C1400 of the 16S RNA.

Base Sequence↗