Development of rostrocaudal dendritic bundles in rat thoracic spinal cord: analysis of cholinergic sympathetic preganglionic neurons.

Using monoclonal antibodies to choline acetyltransferase (ChAT) and glial fibrillary acidic protein (GFAP), we have analyzed the development of the dendritic bundles formed by cholinergic sympathetic preganglionic neurons (SPNs) in relationship to changes in the organization of glial fibers. In adult rat thoracic spinal cord, SPNs in the intermediolateral (IML) and central autonomic (CA) regions extend dendrites in both the mediolateral and rostrocaudal directions, forming a ladder-like pattern in horizontal sections of thoracic spinal cord. We report that, while the mediolateral dendrites form prenatally, the rostrocaudal dendritic bundles are not detected until at least a week later, during early postnatal life. The rostrocaudal dendrites develop rapidly during the first postnatal week, and achieve an adult-like pattern by postnatal day 14. The observed ontogenetic arrangements of dendritic bundles were correlated with the developing organization of astroglial processes with which they are intimately associated. While the appearance of mediolateral dendrites is consistent with the radial organization of glial in the embryonic spinal cord, the developmental time course of the rostrocaudal dendritic bundles coincides with the transformation of glial cells from this predominantly radial or transverse orientation to the randomly-oriented, stellate pattern of mature astrocytes. This temporal association suggests that ontogenetic changes in the organization of glial cells may contribute to the differential development of mediolateral and rostrocaudal dendritic patterns in the spinal cord.     

Cochlear ablation in deafness mutant mice: 2-deoxyglucose analysis suggests no spontaneous activity of cochlear origin

Deafness mutant mice show no stimulus-related cochlear potentials as well as abnormal electrically-evoked responses recorded from the inferior colliculus. Abnormal spontaneous activity in the auditory periphery could result in abnormal development and/or maintenance of the central auditory pathways. We therefore assessed spontaneous activity of cochlear origin in the central nuclei of the mutants by ablating one cochlea and subsequently using the 2-deoxyglucose (2DG) technique to study metabolic activity. Any asymmetries in labeling in a given nucleus should be due to spontaneous activity in the cochlear nerve on the unoperated side. In control animals (+/dn mice undergoing unilateral cochlea ablation), statistically significant decreased 2DG labeling was observed in the ipsilateral PVCN and AVCN, and contralateral MNTB and IC; all receive primary excitatory input from the ablated ear. No significant differences in labeling between right and left sides were observed in any of the nuclei studied in the mutant animals. These findings suggest that there is no spontaneous activity of cochlear origin in these mutants, even though many cochlear nerve fibers and spiral ganglion cells survive.     

Family history evaluation as a predictive screen for childhood hypercholesterolemia. Pediatric Practice Research Group

A study was conducted to evaluate the efficacy of family history factors as screening criteria for childhood hypercholesterolemia. When they were seen for routine care at one of eight office practices, 1005 prepubertal children underwent random serum cholesterol determinations. Parental and grandparental histories of cardiovascular risk factors and atherosclerotic complications prior to 55 years of age were also obtained. Of the initial group, 274 children had total cholesterol levels greater than or equal to 175 mg/dL, and 175 of these children returned for retesting after an overnight fast. A total of 88 children were found to have low-density lipoprotein-cholesterol (LDL-C) values greater than or equal to 90th percentile for age and sex. Maternal and paternal histories of hypercholesterolemia were significantly associated with elevated LDL-C (odds ratio = 7.3 and 2.9, respectively), but had extremely low sensitivities (0.09, 0.15) despite modest positive predictive values (0.42, 0.22). Grandparental histories of sudden death, peripheral vascular disease, and gout were associated with elevated LDL-C, but sensitivities and positive predictive values for all of these factors were less than 0.22. Family history factors most commonly recommended as criteria for cholesterol screening in children did not identify half of all the children with elevated LDL-C and did not selectively identify the most severely affected children. Adding information concerning the presence of childhood obesity did not result in appreciable improvement in LDL-C detection beyond that achieved by family history factors alone. It was concluded that if thorough identification of young children with elevated LDL-C is desired, inclusive population screening rather than a family history-based strategy would be the most effective approach.     

Pyoderma gangrenosum and related disorders

Pyoderma gangrenosum (PG) is an uncommon ulcerative cutaneous condition with distinctive clinical characteristics and a frequent association with systemic diseases. Most frequently among the associated disease list are: inflammatory bowel disease, arthritis, and a variety of hematologic disorders. There is no specific treatment of PG; however, the effective treatment of an accompanying systemic disease, local therapy, and/or the use of topical or systemic agents known to be useful in neutrophil disorders, have been beneficial in most patients.     

Epidemic measles in an isolated unvaccinated population, India

Between June and September, 1986, an outbreak of measles occurred in Pilkhi Primary Health Centre area (population 56,000) in Tehri Garhwal district, Uttar Pradesh, India. Overall, 1092 cases were identified and 62 died; case-fatality ratio was 5.7%. Illness was restricted primarily to children below 15 years of age; 38% cases were in children under 5 and 58% between 5-14 years of age. To better characterize the outbreak, a survey was conducted in 13 affected villages. The age of the cases ranged from 5 months to 19 years (median = 7.0 years). The age-specific attack rates were 22.4%, 54.5%, 46.2% and 35.3% for children under 1, 1-4, 5-9, 10-14 years of age respectively. In as many as four villages, the attack rate in children below ten was 80% or more. Secondary attack rate among family members was 70%. Overall, 82% of children with measles developed complications which consisted mainly of pneumonia, diarrhoea and dysentery. The age-specific case-fatality ratios in infants and children 1-4 years of age were 23.1% and 11.5% respectively; thereafter the rates tended to decline with increasing age and was higher in females than in males (less than 0.05). Pneumonia which was a complication in 39% of measles cases contributed to 56% of deaths. Traditional beliefs and customs in the area were strong and did not encourage treatment of measles cases. Although a measles vaccination programme has been launched in India since 1985, only 30 districts could be covered during the first year and another 90 during 1986.(ABSTRACT TRUNCATED AT 250 WORDS)     

The relationships of anhedonia and the process-reactive dimension to season of birth and infectious disease incidence in schizophrenia

This project was designed to test two hypotheses drawn from a new formulation explaining the exaggerated winter birthrate among hospitalized schizophrenics. The first is that the supposed exaggerated winter birthrate among process schizophrenics actually represents a reduction in spring-fall births caused by prenatal exposure to infectious diseases during the preceding winter--i.e., a high prenatal death rate in process preschizophrenic fetuses. The second is that the level of negative symptoms in survivors at risk for schizophrenia who were born after winters with high infectious disease rates is exaggerated. The findings provided some tentative support for this formulation. Compared with counterparts born after low-disease winters, schizophrenics born after winters with high disease incidences tended to show lower (more reactive) scores on a measure of the process-reaction dimension but higher anhedonia scores.     

Smoking patterns in the coloured population of the Cape Peninsula (CRISIC study)

A cross-sectional study of tobacco-smoking habits in a random sample of 976 coloured subjects aged 15-64 years revealed that smoking was common, 57% of men and 41% of women being current smokers and 10.4% of men and 9.6% of women having stopped smoking. Heavy smoking prevailed, indicating by mean daily consumption of 14.2 and 13.1 cigarettes among male and female smokers respectively; only 33.5% of male and 39.6% of female smokers used less than 10 cigarettes per day. Coloured smokers smoked more heavily during the weekend. Both men and women smoked mostly filter cigarettes. Forty-four per cent of male and 49.5% of female smokers stated that they had attempted to stop smoking, mainly for health reasons. More than one-third of the participants had a positive attitude to combating smoking, particularly those with an educational level higher than Standard 7. Former smokers and heavy smokers had a significantly higher prevalence of ischaemic heart disease than the other participants. Smoking was associated with a low body mass index, low high-density lipoprotein cholesterol levels, low socio-economic standing, high alcohol consumption and type A coronary-prone behaviour in men. In 1982 the economically active coloured population of the Cape Peninsula spent an estimated R36.2 million on cigarettes.     

Dietary calcium intake and bone loss from the spine in healthy postmenopausal women

Controversy exists over the relationship between calcium intake and axial bone loss. We measured bone density of the spine (L2-4) by dual photon absorptiometry (DPA) two times, 7 mo apart, in 76 healthy postmenopausal women aged 40-70 y. Ca intake was assessed by food-frequency questionnaire. Women with a Ca intake less than 405 mg/d lost spine density at a rate that was significantly greater than that of women with an intake greater than 777 mg/d, p = 0.026. There appears to be a threshold of Ca intake below which increased Ca in the diet is likely to be beneficial in reducing spine mineral loss.