Postnatal Survival in Wistar Rats following Oral Dosage with Zidovudine on Gestation Day 10

Postnatal Survival in Wistar Rats following Oral Dosage withZidovudine on Gestation Day 10. GREENE, J. A., AYERS, K. M.,DE MIRANDA, P., AND TUCKER, W. E., JR. (1990). Fundam. Appl.Toxicol. 15, 201–206. Groups of 20 female Wistar ratsfrom Charles River Breeding Laboratories (Kingston, NY) weregiven three oral doses of 100 mg zidovudine/kg at 5-hr intervalson Gestation Day 10 (total dose = 300 mg/kg). Control rats receivedthree oral doses of the vehicle, distilled water. This designapproximated that of an earlier study that reported 38% postnatalmortality among the offspring of Wistar rats given zidovudine.In the study reported here, no adverse effects were noted onmaternal body weight, food consumption, reproductive capacity,or hematology. Similarly, no effects on growth or survival ofthe offspring were noted. Hematology and clinical chemistryvalues were comparable between offspring of treated and controldams, and no treatment-related gross or histopathologic lesionswere noted in the weanling rats. The mean concentration of zidovudinein embryonal homogenates, collected 30 min after administrationof the third dose to the dam on Gestation Day 10, was 21.1 µg/gtissue. This value is approximately one-third of the mean drugplasma concentration (62.6 µg/ml) measured in the thmsat the same time point. The dramatic difference in results inthe two studies may be related to differences in Wistar ratsfrom two different sources or to other unknown factors associatedwith the design and conduct of the studies. The results of thecurrent study were consistent with other preclinical studieson the reproductive toxicity of zidovudine in rats and rabbits.     

A new role for neuroscience nurses: the case manager.

Nurse case managers are becoming more visible within the nursing profession. Practice settings range from acute care to independent companies developed for the purpose of case management. In each area, the development of a more autonomous nurse is emphasized. Neuroscience nurses are particularly suited for the role of case manager since their patients often require extensive rehabilitation and nursing care. As patients face earlier discharges, neuroscience case managers will be the link to vital resources in what is now an often fragmented system of care.     

Deranged hydrophobic barrier of the rat gastroduodenal mucosa after parenteral nonsteroidal anti-inflammatory drugs

BACKGROUND & AIMS: Parenteral administration of nonsteroidal anti- inflammatory drugs (NSAIDs) may cause gastrointestinal mucosal lesions. The aim of this study was to investigate whether parenteral NSAIDs alter surface hydrophobicity of the gastroduodenal mucosa. METHODS: Conscious rats received indomethacin or diclofenac subcutaneously at different doses (0.5-10 mg/kg). Surface hydrophobicity of gastric and duodenal mucosa was determined by contact angle measurement at various time points; mucosal prostaglandin synthesis and mucus phospholipid content were measured. Also, the effects of NSAIDs were studied in bile duct-ligated rats. RESULTS: A single 1-2-mg/kg dose significantly decreased hydrophobicity in the stomach and duodenum. The decrease was associated with a reduction in mucus phosphatidylcholine. In the duodenum, mucosal prostaglandin synthesis was restored 24 hours after NSAID dosing, but hydrophobicity was still decreased. There was no adaptation to long-term treatment. In bile duct-ligated rats, NSAIDs did not decrease gastric or duodenal hydrophobicity. Moreover, oral administration of bile from rats pretreated with parenteral NSAIDs significantly decreased mucosal hydrophobicity in untreated rats. CONCLUSIONS: Low-dose NSAIDs by parenteral route impair the physicochemical barrier against luminal acidity and render the mucosa susceptible to injury. Excretion of NSAIDs in bile seems to play a key role in this effect. (Gastroenterology 1997 Jun;112(6):1931-9)     

New organosilicon maxillofacial prosthetic materials.

OBJECTIVES: The silicone elastomer A-2186 is a widely used maxillofacial prosthetic material. It is a pourable two-component silicone rubber cured by a platinum catalyst. Used as a prosthetic material, A-2186 has short working time and because of its hydrophobic nature, poor adhesion to non-silicone based adhesives. The purpose of this study is to evaluate the physical properties of new prosthetic materials based on methacryloxypropyl-terminated polydimethylsiloxane (MPDS-MF), and to compare the properties with those of A-2186. METHODS: Hardness, tensile strength, ultimate elongation, tear strength and adhesive bonding strength of MPDS-MF and A-2186 with and without additives were determined and compared. The bonding strengths of the extrinsic colorant carrier with the prosthetic materials were also determined. Statistical analyses were done using a two-way analysis of variance (ANOVA). For significant effects, post-hoc tests were done using the Bonferroni correction. RESULTS: The hardness of MPDS-MF is similar to A-2186. However, tensile strength, tear strength, ultimate elongation, and adhesive bonding strength of MPDS-MF are higher than those of A-2186. SIGNIFICANCE: MPDS-MF is cured by free radical thermal polymerization and crosslinking. The working time of MPDS-MF, unlike A-2186, is long. The presence of methacrylate groups in MPDS-MF enhances its adhesion to non-silicone based adhesive. Based on the present study, it appears that MPDS-MF is suitable for use in fabricating of clinical prostheses.     

Orbital cellulitis: review of 23 cases from Saudi Arabia.

We studied a total of 23 patients with orbital cellulitis and/or orbital abscess over a period of four years in Saudi Arabia. The study showed a high rate of abscess formation (12/23) and surgical intervention (17/23). Twelve out of 23 patients were 18 or more years of age. Furthermore, 12 of 23 (52%) patients had blind eyes on admission and remained blind after treatment, and one patient died of cavernous sinus thrombosis. Only 7/23 (30%) had a predisposing cause of primary sinus disease. This study of orbital cellulitis in a developing country presents a variation in disease pattern from previous reports and suggests that delay in the initiation of antibiotic therapy may lead to serious complications which may be life threatening. The course and outcome of orbital cellulitis may vary, depending on the predisposing factor, time of onset, associated systemic disease, or delay in initiation of treatment.