Prehospital resuscitation and sudden cardiac death

Rates of survival horn pre-hospital cardiac arrest are often used to judge the quality of emergency medical systems. Despite many advances in technology and pharmacotherapy over the last two decades, overall survival rates in most systems remain disappointing. Objective analysis of different systems of care and associated outcomes has been hampered by a lack of uniform data reporting. Attempts to improve survival must focus on the key to resuscitation from sudden cardiac death, that is rapid response defibrillation.     

Solitary bronchioloalveolar carcinoma: CT criteria

The computed tomographic (CT) scans of 30 patients with solitary bronchioloalveolar carcinoma were reviewed. Common features at CT included the peripheral or subpleural location of a pulmonary mass (25 cases), pseudocavitation (18 cases), heterogeneous attenuation (17 cases), irregular margins forming a star pattern (22 cases), and pleural tags (21 cases). Using these CT criteria, four independent observers attempted to identify cases of bronchioloalveolar carcinoma from a larger sample of lung cancers and benign lesions by categorizing a series of test cases into four probability categories. Although the bronchioloalveolar carcinomas were correctly ranked in the two highest probability categories 75% of the time (in 45 of 60 cases), there was considerable overlap with other lung lesions, particularly with adenocarcinoma and large cell undifferentiated carcinoma. However, even though the typical features of bronchioloalveolar carcinoma are not invariable or highly specific, they are characteristic enough to suggest the diagnosis.     

Experimental Studies on Reproduction with the Lipid-Regulating Agent Gemfibrozil

Experimental Studies on Reproduction with the Lipid-RegulatingAgent Gemfibrozil. FITZGERALD, J. E., PETRERE, J. A., AND DELA IGLESIA, F. A. (1987). Fundam. Appl. Toxicol. 8, 454–464.Gemfibrozil, a new lipid-regulating agent, was evaluated inrats and rabbits for effects on various phases of the reproductionprocess. In teratology studies groups of pregnant rats and rabbitsreceived gemfibrozil at doses up to 200 mg/kg during organogenesis(rat, Days 6–15; rabbit, days 6–18). For peri- andpostnatal studies, groups of pregnant rats were given 92 or3 31 mg/kg from Day 15 of gestation through weaning. In fertilitystudies groups of sexually mature male rats were given 93 or326 mg/kg of gemfibrozil for 61 days and females were given94 or 318 mg/kg for 15 days prior to mating within treatmentgroups. Drug administration continued in females through gestationand weaning of the F₁ offspring. In subsequent fertility experiments,treated male rats were mated with untreated females and treatedfemales were cohabitated with untreated males. Gemfibrozil didnot elicit a teratogenic response in either rats or rabbitsup to doses that resulted in maternal toxicity. Reduced pupweights during the neonatal and weaning periods in the femalefertility study as well as in the perinatal–postnatalstudy were the only apparent drug effect. Treatment of femalerats prior to mating had no significant effects on general reproductiveparameters. Male rats given doses of about 300 mg/kg/day showedinconsistent and equivocal lower rates of fertility relativeto the concurrent controls. No adverse effects were seen inthe reproductive performance of offspring of gemfibrozil-treatedmale rats.     

Identification of a gene disrupted by a microdeletion in a patient with X-linked retinitis pigmentosa (XLRP)

The gene for the most frequent from of X-linked retinitis pigmentosa (XLRP), RP3, has been assigned by genetic and physical mapping to a segment of less than 1000 kbp, which is flanked by the marker DXS1110 and the ornithine transcarbamylase (OTC) gene. In search of microdeletions, we have screened the DNA of 30 unrelated patients with XLRP by employing a representative set of YAC-derived DNA fragments that were generated by restriction enzyme digestion and PCR amplification. In one of these patients, a 6.4 kbp microdeletion was detected which was not present in the DNA of 444 male controls. A cosmid contig spanning the deletion was constructed and used to isolate cDNAs from retina-specific libraries. Exons corresponding to these expressed sequences as well as other putative exons were identified by sequencing more than 30 kbp of the critical region. So far, no point mutations in these putative exon sequences have been identified.      

Positional cloning of the gene for X-linked retinitis pigmentosa 3: homology with the guanine-nucleotide-exchange factor RCC1

The gene for retinitis pigmentosa 3 (RP3), the most frequent form of X- linked RP (XLRP), has been mapped previously to a chromosome interval of less than 1000 kbp between the DXS1110 marker and the OTC locus at Xp21.1-p11.4. Employing a novel technique, YAC Representation Hybridization (YRH)', we have recently identified a small XLRP associated microdeletion in this interval, as well as several putative exons including the 3' end of a gene that was truncated by the deletion. cDNA library screening and sequencing of a cosmid centromeric to the deletion has now enabled us to identify numerous additional exons and to detect several point mutations in patients with XLRP. The predicted gene product shows homology to RCC1, the guanine-nucleotide- exchange factor (GEF) of the Ras-like GTPase Ran. Our findings suggest that we have cloned the long-sought RP3 gene, and that it may encode the GEF of a retina-specific GTP-binding protein.