Functional development of the neonatal rat retinotectal pathway

Electrophysiological activity in the neonatal rat superior colliculus was recorded to measure neuronal and synaptic activity, and, therefore, functional development. Neonatal rat pups were studied from five days to two weeks of age. The earliest activity in the superior colliculus were spontaneous discharges at a frequency of one unit per animal on postnatal day 6 (P6). Spontaneously discharging units were more numerous at P8, and the number peaked on P10. The first clear response to optic nerve stimulation was seen on P10, with relatively long and variable latencies. By P14, electrically evoked responses had much shorter latencies. The results are in line with the first response to light flash in the superior colliculus at P12/13. The evidence suggests that functional development of the rat retinotectal pathway begins at the end of the first week after birth, and that much of the functional maturation occurs mainly during the second week after birth.     

Abortion patients in 1994-1995: characteristics and contraceptive use

Results of a 1994-1995 national survey of 9,985 abortion patients reveal that women who live with a partner outside marriage or have no religious identification are 3.5-4.0 times as likely as women in the general population to have an abortion. Nonwhites, women aged 18-24, Hispanics, separated and never-married women, and those who have an annual income of less than +15,000 or who are enrolled in Medicaid are 1.6-2.2 times as likely to do so; residents of metropolitan counties have a slightly elevated likelihood of abortion. When age is controlled, women who have had a live birth are more likely to have an abortion than are those who have never had children. Catholics are as likely as women in the general population to have an abortion, while Protestants are only 69% as likely and Evangelical or born-again Christians are only 39% as likely. Since 1987, the proportion of abortions obtained by Hispanic women and the abortion rate among Hispanics relative to that for other ethnic groups have increased. The proportion of abortion patients who had been using a contraceptive during the month they became pregnant rose from 51% in 1987 to 58%. Nonuse is most common among women with low education and income, blacks, Hispanics, unemployed women and those who want more children. The proportion of abortion patients whose pregnancy is attributable to condom failure has increased from 15% to 32%, while the proportions reporting the failure of other barrier methods and spermicides have decreased.     

Long-term outcome of adult-onset minimal-change nephropathy

BACKGROUND: Adult-onset minimal-change nephropathy has been associated with a slower response to corticosteroids and a less benign prognosis when compared to children. However, there are few long-term outcome data reported. METHODS: We have reviewed retrospectively 51 idiopathic adult-onset minimal-change nephropathy patients investigated and treated at a single centre. RESULTS: Male to female ratio was 1:1.4, mean age at diagnosis was 37 years, and average length of follow-up was 14.1 years. Significant comorbidity was identified in 33%. A raised serum creatinine was found in 55% but returned to normal almost invariably upon remission. At presentation, hypertension was found in 47% of patients, microscopic haematuria in 33%, hypercholesterolaemia and hypertriglyceridaemia in 96%, and hyperuricaemia in 42%. Remission (complete or partial) was achieved by 46, 70 and 92% within 4, 8 and 21 weeks respectively, in patients treated with steroids; steroid resistance was encountered in 8%. The time to remission was positively correlated with age (P = 0.002) and initial albumin level (P = 0.005), and negatively correlated to the number of subsequent relapses (P = 0.029); 33% of patients had a spontaneous remission at some time during the disease course. Patients with multiple relapses were treated with cyclophosphamide and 63% of them had remained in remission after 5 years. Hypertension was present in 25% of patients after an average interval of 11 years. At the time of the final follow-up, only three patients had a raised creatinine and all but three patients were in complete remission. CONCLUSIONS: Adult-onset minimal-change nephropathy shares the same good long-term outcome as the childhood counterpart, with sustained remission and preserved renal function.     

Analysis of a three-unit redundant system with two types of repair and inspection

This paper deals with a redundant system with two types of spare units—a warm standby unit for instantaneous replacement of a failed operative unit and a cold standby which takes a random amount of time to become operative/warm. After each repair a unit is sent for inspection to decide whether the repaired unit is perfect or imperfect. If the repaired unit is found to be imperfect then it goes for post-repair. Using the regenerative point technique in the Markov renewal process several reliability characteristics of interest to system designers and operation managers are obtained.