Endotoxin leucoencephalopathy in the telencephalon of the newborn kitten.

Prolonged exposure of the neonatal kitten to a lipopolysaccharide results in a telencephalic leucoencephalopathy characterized by astrogliosis and necrosis. The visceral organs of neonatal kittens and the telencephalon of mature cats are relatively resistent to the adverse effects of this lipopolysaccharide.

Vasculature to the germinal matrix in rabbit pups.

The authors report a study of the cerebral vasculature of premature rabbits pertaining to the germinal matrix (GM). A pigmented silicone material (Microfil) was injected into the carotid artery of anesthetized rabbits. Methyl methacrylate vascular casts of a similar group of premature rabbits were examined by scanning electron microscopy. The GM is supplied by arteries from both the basal and convexity surfaces of the brain. Vessels could be identified as arteries or veins by their typical patterns of branching and by the characteristic impressions made on the methyl methacrylate casts by endothelial nuclei. Specific evidence of structural weaknesses in the vasculature, which could be a site of predilection for GM bleeding, was not observed. The similarities in basal ganglia vasculature between premature rabbits and humans justifies using the rabbit model to study vascular aspects of the GM and intraventricular hemorrhage.

Life supporting first aid (LSFA) teaching to Brazilians by television spots.

Accidents in developing countries are frequent and have high mortality and morbidity rates. In Brazil, in 1995-1996, the year of this study, life supporting first aid (LSFA), which includes cardiopulmonary resuscitation (CPR) basic life support (BLS) was not taught in schools. With the population of 165 million, the only way to teach the adult population on a large scale would be by television (TV), that is widely viewed. This study compares two groups of factory employees - 86 controls without TV exposure to LSFA and 116 exposed to brief LSFA skill demonstrations on TV. Their ability to acquire eight LSFA skills was evaluated: external hemorrhage control; immobilization of a suspected forearm fracture; treatment of a skin burn by cold flush; body alignment after a fall; positioning for shock and coma; airway control by backward tilt of the head; and CPR (steps A-B-C). Simulated skill performance on the evaluating nurse or manikin was tested at 1 week, 1 month, and 13 months. In the control group, 1-31% performed individual skills correctly; as compared to 9-96% of the television group (P<0.001). There was excellent retention over 13 months. Over 50% of the television group performed correctly five of the eight skills, including positioning and hemorrhage control. Television viewing increased correct airway control performance from 5 to 25% of trainees, while it remained at 3% in the control group. CPR-ABC performance, however, was very poor in both groups. We conclude that a significant proportion of factory workers can acquire simple LSFA skills through television viewing alone, except for the skill acquisition of CPR steps B (mouth-to-mouth ventilation) and C (external chest compressions) which need coached manikin practice.

Mechanoreceptors in human cruciate ligaments. A histological study.

We obtained human cruciate ligaments at the time of total knee replacement and from autopsy and amputation specimens, and examined histological sections of the ligaments for the presence of mechanoreceptors using the Bodian, Bielschowsky, and Ranvier gold-chloride stains for axons and nerve-endings. The cruciate ligaments obtained at the time of total knee replacement were too distorted by disease processes to be of use. The autopsy and amputation specimens, however, contained fusiform mechanoreceptor structures measuring 200 by seventy-five micrometers, with a single axon exiting from the capsule of the receptor. One to three receptors were found at the surface of each ligament beneath the synovial membrane, and were absent from the joint capsules and menisci. Morphologically the receptors resembled Golgi tendon organs, and it seems likely that they provide proprioceptive information and contribute to reflexes inhibiting injurious movements of the knee. This is the first histological demonstration of mechanoreceptors in human cruciate ligaments.

Neonatal endotoxin encephalopathy.

Telencephalic white matter of the neonatal kitten frequently contained diffuse astrogliosis or focal necrosis (sometimes including the thalamus and the caudate) following a single intraperitoneal injection of Escherichia coli lipopolysaccharide. No evidence for a disseminated intravascular coagulopathy was found. Telencephalic lesions in neonatal monkey and rabbit were also hemorrhagic. Enhanced karyorrhexis of glial nuclei was presented in the telencephalic white matter of the neonatal rat. In the kitten, a delay in the generation of macrophages and hypertrophic astrocytes occurs following transient neonatal endotoxemia. Marked weight loss and temperature fluctuation are prominent systemic effects. Large hemispheric cavitary lesions are not accompanied by obvious neurological deficits in the kitten.

Caffeine induces cardiac and other malformations in the rat.

At various gestational periods, caffeine was injected intra-arterially or intraperitoneally into pregnant rats. The teratogenic effects of caffeine on the fetal heart were dose dependent and detectable at relatively low concentrations. The most susceptible stage was during septation of the heart. The most common cardiovascular malformation was ventricular septal defect. Extracardiovascular anomalies, such as decreased thymic weight and degeneration of the lens, were found in all fetuses; skeletal malformations were found in some fetuses.