Caspases: intracellular signaling by proteolysis

The standard working assumption of careful CRT imaging is that each pixel is imaged independently, through a point nonlinearity (the monitor's gamma function, relating screen luminance to input voltage), and then blurred by the point-spread function of the beam spot on the phosphor. Unfortunately most monitors have inadequate video bandwidth, DC restoration, and high-voltage regulation to live up to this ideal model. Two tests are recommended for assessing a CRT's deviation from the pixel-independence model.     

Centralization in obstetrics: pros and cons

Possible advantages and disadvantages of a general centralization of German obstetric facilities are analysed in the study. The need for centralization of risk cases, especially premature births (regionalization) is pointed out. Centralization appears appropriate, since every fifth maternity unit in Germany (19.78%) has 300 or fewer deliveries per year. This one fifth of perinatal clinics accounts for 6.3% of all deliveries (N = 49450). There are appreciable differences between the old and new federal states (Bundesl?nder): in the recently acceded federal states, 48.7% of all perinatal clinics have deliveries of 300 and less per year. This group of perinatal clinics accounts for 29% of all deliveries in the new federal states. We have carried out a survey of the mother's attitude to centralization: out of 416 patients in the Detmold women's hospital whose mean age was 29.0 +/- 4.2 years, 90.4% were not in favor of general centralization of obstetrics. 43% were also against a centralization of risk cases (regionalization). 75% of the women surveyed objected to centralized obstetrics because of the 'possible absence of the family', the 'possible absence of students and trainees' (44.9%), the 'unfamiliarity with staff and premises' (41.8%) and 'fear of anonymity' (44.5%). The majority of all women (84.1%) did not want to have a drive more than 20 km to an obstetrics center. Fear of 'delivery in a taxi'(78.6%), the 'fear that the husband will come too late to the delivery' (65.4%) and that the 'overall course of the delivery might not be adequate for reasons of time'. The presence of a pediatrics department in conjunction with the perinatal clinic was rated very positively (93%). It is concluded from the data and further juridical considerations that centralization of risk cases (regionalization) is indispensable in the near future and that somewhat more further into the future decentralization should be carried out by closing obstetrics departments with substantially less than 350 deliveries per year. Attention is drawn to some consequences of such a structural reform which will probably have to be initiated by the German Association of Gynecologists and Obstetricians.     

Intraoperative discovery of neuroblastoma in an infant with pulmonary atresia

There have been 28 previously reported cases of neuroblastoma associated with congenital heart disease. Because many of these have been defects of the conotruncal region, it has been proposed that abnormal neural crest cell migration or maturation may be a factor that links these normally disparate pathologic conditions. Most neuroblastomas in these cases have been detected at autopsy or by radiologic studies conducted in the evaluation of the cardiac anomalies. Recently, we discovered an occult posterior mediastinal neuroblastoma in a patient undergoing a unifocalization procedure for tetralogy of Fallot with pulmonary atresia and major aortopulmonary collaterals. The tumor was resected, and the patient has demonstrated no evidence of residual or metastatic neuroblastoma.     

MR imaging of pediatric musculoskeletal inflammatory and infectious disorders

Inflammatory and infectious disorders of the skeletally immature extraspinal musculoskeletal system affect the bones, contiguous soft tissues, muscles, and joints. MR imaging of osteomyelitis, soft tissue infection, inflammatory muscle disease, and acute and chronic joint disease are discussed in the context of underlying pathophysiology. Discussion includes imaging optimization, contribution of MR imaging to overall patient management, and differential diagnostic considerations for the pediatric patient.     

Detection of M. leprae by gene amplification; combined ethidium-bromide staining and probe hybridization

Human and animal studies have clearly demonstrated the advantageous effects of sensorially enriched rearing environments. Nevertheless, little work has been done concerning the long-lasting persistence of all these behavioral modifications. To undertake this question, a very early enrichment animal model was used. From days 10 to 24 after birth, 28 male albino rats were exposed to a multisensory stimulated environment, while other 28 littermates constituted the control group. At 3 and 6 months old two cognitive abilities were analyzed; the spatial working memory (short term memory) and the latent learning capacity (long term memory). The results evidenced an improved working memory in both 3 and 6 months old rats exposed to the early enriched environment. Moreover, the adult early stimulated group performed as well as younger subjects both on error scores and speed to solve this test. Only in the adult group of rats a superior latent learning capacity of stimulated subjects was evidenced. To conclude, the early enriched environment induced: a) persistent cognitive benefits in the adult rat and b) a more relevant influence on the subsequent behavior of older rather than younger subjects.     

Effects of oral exposure to mining waste on in vivo dopamine release from rat striatum

Several single components of mining waste (arsenic, manganese, lead, cadmium) to which humans are exposed at the mining area of Villa de la Paz, Mexico, are known to provoke alterations of striatal dopaminergic parameters. In this study we used an animal model to examine neurochemical changes resulting from exposure to a metal mixture. We used microdialysis to compare in vivo dopamine release from adult rats subchronically exposed to a mining waste by oral route with those from a control group and from a sodium arsenite group (25 mg/kg/day). We found that arsenic and manganese do accumulate in rat brain after 2 weeks of oral exposure. The mining waste group showed significantly decreased basal levels of dihydroxyphenylacetic acid (DOPAC; 66.7 +/- 7.53 pg/ microl) when compared to a control group (113.7 +/- 14.3 pg/ microl). Although basal dopamine release rates were comparable among groups, when the system was challenged with a long-standing depolarization through high-potassium perfusion, animals exposed to mining waste were not able to sustain an increased dopamine release in response to depolarization (mining waste group 5.5 +/- 0.5 pg/ microl versus control group 21.7 +/- 5.8 pg/ microl). Also, DOPAC and homovanillic acid levels were significantly lower in exposed animals than in controls during stimulation with high potassium. The arsenite group showed a similar tendency to that from the mining waste group. In vivo microdialysis provides relevant data about the effects of a chemical mixture. Our results indicate that this mining waste may represent a health risk for the exposed population.