Association of intracerebral bone fragments and epilepsy in missile head injuries

Twenty young adults sustained missile injuries in the Lebanese war. They underwent repeated clinical electroencephalographical (EEG), computerised tomography scanning (CT-scan) and polysomnographic (PSG) examinations during a 6-year period. All the patients were young adult males with an average age of 23, previously healthy according to their army profiles. Three of 20 developed between 3 to 14 months following injury generalised tonic-clonic convulsions. The unique common epileptogenic feature characterising the 3 epileptics was the presence of bone fragments in lacerated brain tissue. The possible causal relationship between the presence of the bone fragments and epileptogenesis is discussed.     

Electron microscopy of CO2-laser-induced effects in human fibrocartilage

Previous reports of effects of CO2 laser energy on human fibrocartilage suggest thermal injury extends to a depth of approximately 70 microns from the target surface with power settings of 35 W and exposure times of 0.5 seconds. The present study was undertaken to look for more subtle evidence of thermal alteration of human fibrocartilage treated with CO2 laser irradiation. Fifteen human menisci were irradiated at power settings of 10, 20, and 30 W with exposure times of 0.1 and 0.5 seconds. The specimens were immediately fixed and sectioned for electron microscopic examination. Loss of a normal cross banding, and marginal clarity of individual collagen fibers were observed in the extracellular matrix and were observed at distances up to 300 microns from the exposed tissue surface. In addition, cellular changes at similar tissue depth consisted of cell membrane invaginations, clumping of nuclear chromatin, breakdown of endoplasmic reticulum architecture, and loss of mitochondria and Golgi complexes from the cytoplasm were observed. This study demonstrates deeper penetration of a radiation that was previously appreciated by light microscopy in irradiated human fibrocartilage, although the implications with respect to contraside viability and healing potential of the tissue in vivo is not known.     

Critical review of the toxicity of methyl n-butyl ketone: risk from occupational exposure.

Methyl n-butyl ketone (MBK) was considered rather harmless until an outbreak of peripheral neuropathy occurred in 1973 among workers exposed to MBK. MBK easily penetrates the skin; pulmonary retention is approximately 80-85% in man. Distribution is widespread with highest levels in blood and liver; MBK also reaches the fetal tissues. MBK metabolism probably depends on the route of exposure, and is very similar to that of n-hexane. The critical organ is the nervous system. These effects find expression as peripheral neuropathy, with potential for serious effects of the central nervous system. From the viewpoint of neurotoxicity, 2,5-hexanedione is the most important metabolite. The neurotoxicity is potentiated by several compounds, while MBK itself potentiates the toxicity of other chemicals. From animal experiments, a no-adverse-effect level (NAEL) could not be established. Peripheral neuropathy may develop in workers exposed to only a few ppm of MBK. The difference in the Occupational Exposure Limits for MBK and n-hexane, as established by several organizations, is questioned in view of the neurotoxic effects of these substances.     

A Prospective Study on the Safety of Immunotherapy in Children with Severe Asthma

One hundred and six of 503 (21%) consecutive children with asthma, who from 1979 to 1983 commenced hyposensitization therapy, were prospectively studied on the safety of immunotherapy. More than 80% of the patients completed therapy without side effects. Thirteen patients were withdrawn from hyposensitization due to moderate and predictable, but intolerable, side effects such as asthma/rhinitis, urticaria and subcutaneous nodules and hypersensitivity to aluminium. However, more alarming was the outcome in six children, who after an uneventful course of immunotherapy and after several months on maintenance therapy, suddenly, 5 to 20 min (mean 10 min) following an earlier tolerable allergen injection, developed severe, anaphylactic reactions, in three of them nearly fatal. Mould extracts were responsible for the most frequent and serious side effects (Alternaria iridis/alternata, 3 patients, Cladosporium herbarum, 8 patients). Furthermore, serious, but not immediately life-threatening, anaphylactic reactions occurred in two children treated with Phleum pratense. On the other hand, hyposensitization with Dermatophagoides pteronyssinus was very well tolerated.     

Antiepileptic drug toxicity: Definition and mechanism of action

A detailed review of the adverse reactions of anticonvulsants is given, focusing on the definitions of drug toxicity, sources of information, patterns of durg utilization, pharmacokinetic variables and different mechanisms of action. The information available in the literature provides a wide spectrum of drug toxicity with no attempt at a practical definition of the reported events. This favors uncertainty among practising physicians, who are led to use the individual items with different attitudes. Suggestions are given for the evaluation, prevention and treatment of anticonvulsant drug toxicity.

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Sommario La presente è una revisione critica dei diversi aspetti della tossicità dei farmaci antiepilettici. L'analisi della letteratura è condotta con particolare riferimento alle diverse fonti di informazione, ai pattern di utilizzo dei singoli principi attivi, ai dati farmacocinetici ed ai meccanismi di azione farmacologica sottostanti. L'ampio panorama che ne deriva non consente una definizione pratica degli effetti indesiderati degli anticonvulsivanti. Ciò determina incertezza e confusione nella pratica medica, con conseguente diversità di comportamenti. La rassegna si conclude con la presentazione di alcuni suggerimenti pratici per la valutazione, la prevenzione ed il trattamento della tossicità da anticonvulsivanti.

     

Response of the Human Gastrointestinal Tract to Erythromycin

Erythromycin has been shown to increase gastrointestinal motility in dogs when given in large doses, whereas small doses of the antibiotic elicit a premature migrating motor complex (MMC) in both dogs and humans. To study the effects of therapeutic doses of erythromycin in humans, erythromycin was given to 14 human volunteers either intravenously, 7 mg (kg · 30 min), or orally (500 mg) and pressure recordings were made from perfused or solid state catheters. Migrating motor complexes were counted before and after erythromycin administration. Intravenously administered erythromycin caused a large increase in the amplitude, duration, and frequency of gastric contractions whereas the small bowel appeared to be inhibited. No MMC was observed after the onset of the intravenous infusion. After oral administration of erythromycin the number of MMC increased significantly. Erythromycin caused side effects in 71% of subjects. In conclusion, at therapeutic doses erythromycin causes a disturbance of human upper gastrointestinal motility and can prove a useful tool in motility studies.     

防治衰老和促智药物的研究

本文综述了防治衰老和促智药物的研究进展。着重介绍作者实验室研究结果:利用荧光指示剂Fnra—2/AM,对平滑肌细胞和神经细胞内的游离钙浓度进行了测定,表明SA具有很强的钙拮抗作用;采用主动和被动回避性反应方法及多种化学性记忆障碍模型,观察到小鼠、大鼠在以尼莫地平0.05至0.1mg/kg灌胃时,主动和被动回避性条件反应有显著改善,并可拮抗樟柳碱和戊巴比妥钠引起的记忆巩固障碍;对一叶秋碱和土的宁影响小鼠记忆过程的作用进行了研究比较,表明一叶秋碱通过拮抗中枢GABA而对记忆过程起到促进作用,未观察到土的宁对学习记忆的易化作用;采用一次性训练的被动回避性条件反应和水迷宫法,观察到人参和三七均可提高小鼠学习效应和改善记忆力,但人参明显优于三七。     

The use of restricted spectral range red lenses for the diagnosis and relief of dazzlement of a rod monochromat

An infant rod monochromat was diagnosed and was then treated with the Younger PLS 550 lens. The comparison in use of PLS 550 and a neutral density lens confirmed the presence of cone dysfunction. The use of this lens takes advantage of the spectral shift in luminosity between rods and cones. Younger PLS 550 and PLS 530 tints are used for the relief of photophobia according to prevailing brightness. This paper discusses patient management with the use of these lenses and some characteristics of the vision of a rod monochromat.     

Some acute and long-term effects of exposure in welding and thermal-cutting operations in Nigeria

Summary The analysis of welding fumes has shown that toxic gases are present that are irritating to the respiratory system; these gases include nitrogen dioxide and ozone, as well as the oxides of cobalt and chromium. The acute and long-term effects of exposure are assessed in the context of a welding and metal plant in Nigeria. Evidence of long-term respiratory impairment and potential lung cancer was found.     

Persistence of anti-HBs and protective efficacy after administration of hepatitis B vaccine

To evaluate the effect of hepatitis B vaccine on the persistence of anti-HBs and its efficacy in preventing hepatitis type B, anti-HBs and anti-HBc levels were studied over a period of 5.5 years. Plasma-derived hepatitis B vaccine, containing 20 micrograms of HBsAg protein, was injected subcutaneously in 122 healthy medical staff members, followed by two identical injections 1 and 6 months later. Anti-HBs and anti-HBc levels were then measured by radio-immunoassay. The anti-HBs titres were expressed as the sample/negative (S/N) ratios, and an S/N ratio of more than 2.1 was considered positive. The mean (and s.d.) anti-HBs titre peaked 7 months after the first vaccination with an S/N ratio of 153.6 +/- 149.8, after which it decreased with time. The mean anti-HBs titre dropped to an S/N ratio of 8.0 +/- 5.1 5.5 years after the first vaccination. The percentage of vaccinees who were anti-HBs positive also gradually decreased with time after a peak of 84.2% at 7 months following the first vaccination. The percentage of vaccinees who were anti-HBs positive was 38.9% 5.5 years after the first vaccination. The anti-HBc level was not positive in all subjects during the observation period. Five vaccinated volunteers who had developed anti-HBs after the basic vaccination, but whose acquired antibody level became negative within 4.5 years following the first vaccination, were administered a booster dose of 20 micrograms of HBsAg 4.5 years after the first vaccination. Only one of these subjects did not respond to the booster vaccination.(ABSTRACT TRUNCATED AT 250 WORDS)