Nicotine applied by transdermal patch induced HSV-1 reactivation and ocular shedding in latently infected rabbits.

The identification of factors involved in herpes virus latency and reactivation is critical to a better understanding of the mechanisms essential to viral neuroinvasiveness and neurovirulence. Recurrent episodes of ocular herpes infections cause irreversible corneal scarring and are the primary cause of loss of vision due to an infectious agent in industrialized countries. In this study, we examined the ability of nicotine, a compound known to be involved in stress-associated immunomodulation and recognized as one of the most frequently used addictive agents, to induce ocular shedding in rabbits latently infected with herpes simplex virus type 1 (HSV-1) strain McKrae. New Zealand white rabbits latently infected with HSV-1 at 3-4 weeks post-inoculation were randomly divided into two groups. The corneas of all rabbits were free of lesions as verified by slit lamp biomicroscopy. One group received nicotine by transdermal patch (21 mg/day) for 20 days and the other group served as the control. Reactivation data were obtained by detection of virus in tear film collected by ocular swabbing performed concurrently with the administration of nicotine. Compilation of data from three separate experiments demonstrated that 16.5% (258/1560) of the swabs taken from rabbits treated with nicotine were positive for virus, compared with 8.3% (53/639) of swabs taken from controls. Rabbits receiving nicotine exhibited a significantly (P < 0.0001) higher rate of ocular shedding than controls. The concentration of nicotine in the serum was determined at various times (0-24 hrs) after new patch replacement. Peak (average) serum level of nicotine was obtained 8 hours after patch replacement and exhibited a broad range of values (0.233 microg/mL-6.21 microg/mL). These results suggest that an initial systemic exposure to nicotine significantly increases HSV-1 reactivation. Further studies are needed to reveal any effects of nicotine dependency and nicotine withdrawal on herpesvirus reactivation.

Relationship of phencyclidine and pregnancy outcome.

OBJECTIVE: To analyze the relationship of phencyclidine (PCP) and pregnancy outcome, as judged by low birth weight (< 2,500 g). STUDY DESIGN: A retrospective, case-control study of PCP use was conducted among pregnant women who delivered at a large hospital in New Orleans. PCP use was ascertained by urine screening at the time of obstetric admission. Three control patients were selected for each case, matched for age, parity and month of delivery. The study intended to address the prevalence of low birth weight. RESULTS: Between January 1990 and June 1996, 13,653 patients delivered. Of these, 23 were identified as PCP users. PCP users had smaller infants (2,698 vs. 3,011 g, P < .05); that may have been accounted for by a reduction in gestational age (37.3 vs. 38.3 weeks, P = NS). The users were more likely to give histories of using tobacco, alcohol or marijuana but not cocaine. Syphilis and diabetes mellitus were found more often in the study group. Multisubstance use was also common in the study group. The prevalence of low birth weight was not statistically different for the study and control groups. CONCLUSION: PCP use was not associated with an increase in low birth weight. When identified, patients using PCP require comprehensive evaluation.

Attenuation of alcohol-induced hypothermia by cyclo (His-Pro) and its analogs.

Acute administration of cyclo (His-Pro) to rats cause a dose-dependent decrease in ethanol-induced hypothermia. Bromination of the imidazole moiety of histidine in cyclo (His-Pro) resulted in a significant increase in its potency to attenuate ethanol hypothermia. In contrast, benzylation of the imidazole moiety of histidine or the substitution of one or both of the amino acids in cyclo(His-Pro) led to a total loss of its thermomodulatory activity. In conclusion, it appears from these preliminary data that it may be possible to design analogs of CHP that may be effective antagonists for ethanol hypothermia.

Cranioplasty using gentamicin-loaded acrylic cement: a test of neurotoxicity.

Cranioplasty represents a formidable challenge for neuro-surgeons, with a significant morbidity from both early and late wound infections. Polymethylmethacrylate (PMMA) is one of the most widely used materials in this setting. Despite the advantages of this material, such as ease of handling and inert biochemical properties, it is still a foreign body that is prone to infection. We present an animal model using a gentamicin-impregnated PMMA patch to assess the neurotoxicity as well as the efficacy of using this as an alternative material to lessen the infectious morbidity in this clinical setting. In part two of our experiment, we used a PMMA patch of similar weight and surface area in a physiological saline solution to determine the rate of gentamicin elution from the patch. The results obtained appear promising with no evidence of neurotoxicity and warrant further study to assess the clinical efficacy of PMMA in this setting.

Optimization of conditions for the simultaneous separation of ten tryptophan metabolites using reversed-phase high-performance liquid chromatography.

A reversed-phase high-performance liquid chromatographic (RP-HPLC) method for the separation of tryptophan and ten metabolites of tryptophan pyrrolase pathway has been developed by sequential optimization of mobile phase, by adjusting the pH, the concentration of triethylamine and the gradient elution. The baseline resolution of the compounds, by this optimized procedure, is obtained with an analysis time, including the re-equilibration period, of less than 30 min. We believe this is the first RP-HPLC method that can separate tryptophan and ten of its metabolites in a single chromatographic run.

Isolation of cyclo(His-Pro)-like immunoreactivity from human urine and demonstration of its immunologic, pharmacologic, and physico-chemical identity with the synthetic peptide.

Measurements of cyclo(His-Pro) levels in human urine were carried out by specific radioimmunoassay. Cyclo(His-Pro)-like immunoreactivity in Human urine was found to be immunologically, pharmacologically, and physico-chemically identical to that of synthetic cyclo(His-Pro). The concentration of urinary cyclo(His-Pro) in 24-h collection was 1133.8 +/- 122.5 nmol/L, with a range of 606 to 1865 nmol/L. The daily excretion rate of cyclo(His-Pro) was 1812 +/- 248 nmol cyclo(His-Pro)/g creatinine, or 1814 +/- 199 nmol cyclo(His-Pro/day.

Tobramycin dosing in the puerperal patient.

Serum levels of tobramycin were determined with an enzyme immunoassay technique in 20 puerperal women with postcesarean endometritis who were being treated with metronidazole-tobramycin. Ideal dosing was then calculated to attempt to provide peak serum levels between 5 and 8 micrograms/mL and trough serum levels less than 2 micrograms/mL. In eight patients, therapeutic serum levels could not be attained even at doses greater than the package-insert recommendation of 3 mg/kg/d. Therapeutic levels were achieved in five patients with doses between 3 and 5 mg/kg/d and in seven patients only at doses above the maximum recommended daily dose of 5 mg/kg. The puerperal patient appears to usually require much higher dosages of tobramycin than usual, and serum levels must be monitored for therapeutic reasons rather than for toxicity.

PCP abuse in New Orleans: a six-year study.

Methods for determination of PCP in body fluids are presented and a rapid screening method is suggested. The demographics, psychiatric profiles, forensic aspects, and diagnostic problems of PCP abuse are discussed.

Extended EMIT-DAU phencyclidine screen.

In a public hospital emergency room, 580 urines were screened for phencyclidine (PCP) with the routine EMIT-DAU PCP screen, the extended EMIT-DAU PCP screen, and a gas chromatograph/mass spectrometer/computer (GC/MS/COMP) in selected ion mode, which was chosen as the reference method. The extended method produced a 38.5% increase in positives detected over the routine EMIT-DAU PCP screen and allowed 66.4% of the specimens to be signed out as negative without confirmation by GC/MS/COMP. This ability to provide a rapid, relatively inexpensive screen for PCP in urine and, in particular, to eliminate those patients whose specimens are negative, is important in a psychiatric population that contains many acutely psychotic individuals with grossly abnormal behavior.

Ethylene glycol poisoning. The value of glycolic acid determinations for diagnosis and treatment.

Glycolic acid is the ethylene glycol (EG) metabolite that accumulates in the highest concentrations in the blood and may be the major contributing factor to the acute toxicity of EG. Serum and urine levels of glycolic acid have been found to correlate directly with clinical symptoms and mortality in poisoning cases, making it a valuable diagnostic tool. A high pressure liquid chromatographic (HPLC) method for quantitation of glycolic acid in serum was used in several cases of EG ingestion presented to the Louisiana Regional Poison Control Center. The data collected in this study support the value of glycolic acid determination for diagnosis and evaluation of patients poisoned by EG.

4-Bromo-2,5-dimethoxyphenethylamine: identification of a new street drug.

The identification of 4-bromo-2,5-dimethoxyphenethylamine as a street drug is described. NMR, UV, and mass spectral data used in the identification of the compound are presented.

Ethanol ingestion in children. A five-year review.

A five-year review at ethanol ingestions in children at Charity Hospital of Louisiana at New Orleans, revealed nine cases with blood ethanol levels in excess of 21.7 mmole/L (100 mg/dL); none resulted in death. We describe four patients in whom the blood ethanol levels were potentially life-threatening. In one case, we were able to follow the affected child's blood ethanol level serially; the rate of decrease was about twice that reported for an adult.