A novel study of association between Neisseria gonorrhoeae and the human carbohydrate blood groups.

Previous studies of association of ABO blood groups with gonorrhea have shown contradictory results. Despite the interdependencies of ABO, Lewis, and secretor systems, none of the previous studies examined the combined effect of these systems on their proposed association with gonorrhea. This study attempted to redress that and used genotyping in addition to RBC phenotyping to determine correct tissue phenotypes. Samples from 131 gonorrhea-positive individuals and from 175 gonorrhea-negative individuals were typed for ABO and Lewis using routine antisera. Secretor and Lewis genotyping was performed to ensure accurate determination of ABO and Lewis phenotypes. Chi-square and probability values were used to examine whether there is an association of ABO, Lewis, and secretor systems with gonorrhea infection. Neither single nor combined statistical analysis of data sets yielded a significant association of ABO, Lewis, and secretor phenotypes with Neisseria gonorrhoeae. Nevertheless, this study is an example of the approach that should be taken when examining microbial associations with ABO antigens, in turn influenced by coexpression and modification by the interdependent systems of Lewis and secretor, in mucosal tissues.

Pediatric poisonings from household products: hydrofluoric acid and methacrylic acid.

Household products continue to be a cause of poisoning morbibidity and mortality. Young children frequently are exposed to cleaning products and cosmetics in the course of exploring their environment. Most of these exposures are insignificant, but some result in death or permanent disability. This review discusses two products that have been responsible for serious injury and death in children: hydrofluoric acid and methacrylic acid. It also discusses federal initiatives designed to protect children from these and other household hazards.

Baclofen overdose: drug experimentation in a group of adolescents.

BACKGROUND: Baclofen, a lipophilic analog of gamma-aminobutyric acid, is clinically used to control spasticity. We report a mass exposure to baclofen in adolescents seeking intoxication; toxicokinetic data are included. CASE SERIES: A group of adolescents became symptomatic after ingesting 3 to 30 20-mg tablets of baclofen during a party at a suburban Boys' Club. Several children were noted to be very lethargic by chaperones, ingestion was suspected, and paramedics were called. Some white tablets were found in a couch at the site of the party. The Massachusetts Poison Control Center was called, and the tablets were identified as baclofen (20 mg). Fourteen patients were taken to local hospitals; 9 required intubation. Eight adolescents were transferred to our institution. In these 8 patients, symptoms were noted within 1 to 2 hours after overdose. The most common clinical findings included coma (7), hypothermia (6), bradycardia (5), hypertension (4), and hyporeflexia (8). Mean length of mechanical ventilation was 40 hours. Three patients had unifocal premature ventricular contractions. Two patients had tonic-clonic seizures. A single dose of activated charcoal was given to all patients. Drugs administered included nifedipine (1), flumazenil (1), naloxone (1), lorazepam (2), and phosphenytion (2). All patients recovered and were discharged home within 5 days of ingestion. Serial serum baclofen levels were obtained in all intubated patients (range, 0.049 to 6.0; normal, 0.08 to .40 microgram/mL). Levels obtained 14 hours after ingestion showed a linear correlation with length of mechanical ventilation (R2 = 0.9863). Persistent symptoms were noted in some patients, despite nondetectable baclofen levels. Toxicologic screening for drugs of abuse was negative except in 2 patients with ethanol levels, both < 5 mg/dL. CONCLUSION: Baclofen overdose may result in coma, apnea, autonomic disturbances, cardiac conduction abnormalities, and seizures. Levels obtained shortly after overdose correlate with length of mechanical ventilation.

Efficacy of oral versus intravenous N-acetylcysteine in acetaminophen overdose: results of an open-label, clinical trial.

We compared the clinical course of pediatric patients (n = 25) with acetaminophen poisoning treated with an investigational intravenous preparation of N-acetylcysteine (IV-NAC) with that of historical control subjects (n = 29) treated with conventional oral NAC (O-NAC) therapy. Patients received IV-NAC for 52 hours; historical control subjects received O-NAC (72 hours). There were no significant intergroup differences between treatment groups in age (15.5 vs 15.9 years), gender (88% vs 90% female) or distribution of risk categories (probable risk, 12 vs 15; high risk; 13 vs 14). The peak prothrombin time was significantly higher in the IV-NAC group (14.2 vs 13.6 seconds; p = 0.048). Mean treatment delay was significantly longer in the IV-NAC group (14.4 vs 10.4 hours; p = 0.001). Hepatoxicity was noted in two (8.0%) patients in the IV-NAC treatment group and two (6.9%) patients in the O-NAC group. All patients recovered. Our results indicate that 52 hours of intravenous NAC is as effective as 72 hours of oral NAC.

Diagnosis and management of opioid- and benzodiazepine-induced comatose overdose in children.

Opioids and benzodiazepines are two of the most common exposures that cause depressed mental status in children. Establishing a diagnosis of these intoxications may be difficult and is complicated by drugs from these two classes that are not detectable by routine toxicologic screening techniques. Naloxone and flumazenil can be used as diagnostic as well as therapeutic medications in these ingestions. We present a brief review of the mechanism of action, administration recommendations, and adverse effects of naloxone and flumazenil. Although the empiric use of naloxone and flumazenil in the comatose adult patient who presents to the emergency department is being reexamined, many of the concerns do not apply to children. There is still an important role for empiric administration of both naloxone and flumazenil.

Hemolysis after acetaminophen overdose in a patient with glucose-6-phosphate dehydrogenase deficiency.

CASE REPORT: A sixteen year-old-male with a history of glucose-6-phosphate dehydrogenase deficiency ingested an unknown amount of acetaminophen and presented to an emergency department 7.5 h later. He was afebrile. His serum acetaminophen level was 184 micrograms/mL, and his urine toxicologic screen was otherwise negative. Vomiting led to enrollment in a experimental protocol of intravenous N-acetylcysteine. He developed no evidence of subsequent chemical hepatitis but did develop a significant Coomb's negative hemolytic anemia. Hemoglobin on presentation was 14 g/dL and reached a nadir of 9.4 g/dL on admission day 4. CONCLUSION: Patients with glucose-6-phosphate dehydrogenase deficiency who overdose with acetaminophen should be monitored for the possible development of subsequent drug-induced hemolysis.

Determination of nifedipine and its three principal metabolites in plasma and urine by automated electron-capture capillary gas chromatography.

A sensitive, efficient, linear and reproducible capillary gas chromatographic method with electron-capture detection was developed for the quantitation of nifedipine and its primary metabolite M-I in plasma together with the urinary and principal metabolites M-II and M-III. On-column, rather than split-splitless, injection was employed to obviate oxidative degradation of nifedipine to M-I. The photosensitivity of nifedipine was re-examined under laboratory conditions and nifedipine was found to have a half-life in excess of two days when amber glassware and darkroom manipulations under red light were used. The method can determine nifedipine and its metabolites in plasma and urine after a single oral dose of 5 mg and can be applied to measure M-I production by human liver microsomes.

A rapid increase in acetylcholinesterase mRNA during ascidian embryogenesis as demonstrated by microinjection into Xenopus laevis oocytes.

Poly(A+)RNA was prepared from Ciona intestinalis embryos isolated from six different developmental stages. Using Xenopus laevis oocytes as a translation assay, we find that functional acetylcholinesterase (AChE) mRNA is not present in Ciona embryos until shortly before the neural plate stage. These studies show that ascidian AChE mRNA is translated in Xenopus oocytes which should prove useful as an aid for cloning this gene. The interest in this enzyme stems from the possible correlation between cytoplasmic determinants, hypothesized to exist in the muscle lineage cells of these embryos, and the exclusive localization of AChE to larval tail muscle.

Altered activity in the hippocampus is more detrimental to classical conditioning than removing the structure.

Hippocampal ablation has no effect on the acquisition of the rabbit's classically conditioned nictitating membrane response. Systemic administration of scopolamine, which alters hippocampal neuronal activity, severely retards acquisition of the conditioned response in normal animals and those with cortical ablations. In animals with hippocampal ablations, however, scopolamine has no effect on conditioning. These findings suggest that altered neuronal activity in the hippocampus is more detrimental to conditioning than removing the structure.

A monoclonal antibody which binds to the surface of chick brain cells and myotubes: cell selectivity and properties of the antigen.

A monoclonal antibody has been obtained which binds to the cell surface of cultured chick myotubes and retinal and tectal neurons but not fibroblasts, myoblasts and embryonic liver cells. Indirect immunocytochemistry reveals that antigen is present in all layers of the chick neural retina. The antibody therefore recognizes an antigen common to most, if not all, chick neurons. The antigen has been identified by staining SDS gels with [125I]monoclonal antibody and appears to be a polydisperse collection of polypeptides with molecular weights centered about 250 kdalton.