Genetic basis of the difference in alcohol dehydrogenase expression between Drosophila melanogaster and Drosophila simulans.

Drosophila melanogaster and its sibling species, Drosophila simulans, differ in expression of the enzyme alcohol dehydrogenase (ADH). Adult melanogaster flies that are homozygous for the Slow allozyme have approximately twice the level of ADH activity and crossreacting material as simulans adults. There is no corresponding difference in ADH mRNA, however, so this difference in ADH protein level is evidently due to a difference in the rate of translation of the two RNAs and/or to a difference in protein stability. Here we report an interspecific gene-transfer experiment, using P-element transformation, to determine whether this expression difference is due to genetic background differences between the species (trans-acting modifiers) or to cis-acting factors within the Adh gene. When the Adh genes from D. melanogaster and D. simulans are put into the same genetic background, there is no detectable difference in their level of expression. The level is relatively high in the melanogaster background and relatively low in the simulans background. Therefore, the interspecific difference in Adh expression is due entirely to trans-acting modifiers, in spite of the many sequence differences between the Adh genes of the two species, which include two amino acid substitutions.     

Models of stress and meanings of unemployment: reactions to job loss among technical professionals

The same potentially stressful event may have different meanings to different individuals. Such variation may be explained by reference to different models of stress. Two such models, one based on the concept of person-environment 'transactions' and the other on that of a 'psychosocial transition,' are applied to studies of reactions to job loss among technical professionals.     

Rhodopsin topography and rod-mediated function in cats with the retinal degeneration of taurine deficiency

Cats on a taurine-deficient diet were studied with imaging fundus reflectometry and full-field electroretinography. The pattern of rhodopsin loss and the natural history of the disease were determined from maps of the rhodopsin distribution in the central and nasal retina of cats with different degrees of severity of the retinopathy. Rhodopsin loss is first detectable in a focal region of the central retina. Subsequently, there are decreases in rhodopsin in the paracentral and nasal midperipheral retina. The horizontal streak of high rhodopsin levels is preferentially reduced in this retinopathy. The b-wave amplitude of the rod-dominated ERG is markedly reduced in cats with only mildly decreased levels of rhodopsin in the peripheral retina. In an affected cat with moderate rhodopsin loss in the central retina but minimal loss nasally, a light-microscopic study of the retina showed that there was disorganization and shortening of rod outer segments and loss of rod photoreceptor cells in the areas of reduced rhodopsin levels.     

Bericht über Verhandlungen in der „Berliner medicinischen Gesellschaft“, betreffend die operative Eröffnung des Warzenfortsatzes und die Perlgeschwulst im Schläfenbein

Ohne Zusammenfassung     

Selenium deficiency in low birth weight neonates: an unrecognized problem

To determine whether selenium deficiency is common among low birth weight infants in our neonatal intensive care unit, we surveyed blood samples from healthy full-term and preterm infants born in our hospital over a 3-month period. Selenium was measured by electrothermal atomic absorption spectrometry. Glutathione peroxidase was measured in plasma by an automated method. Baseline (less than 72 hours postnatal) selenium concentration and glutathione peroxidase activity were significantly lower in low birth weight infants than in full-term babies. Sequential selenium analyses were obtained in 16 sick low birth weight neonates who remained in the intensive care nursery for up to 6 weeks because of lung disease. All were fed parenterally without supplemental selenium, with or without oral intake, for periods varying from 3 to 60 days. All had a marked decrease from baseline selenium levels, and values below the detection limit of our assay were found in seven infants. Selenium deficiency is much more common in small infants than is generally realized, but the clinical significance in neonates is poorly understood.     

Do Drug Treatment Facilities Increase Clients’ Exposure to Potential Neighborhood-Level Triggers for Relapse? A Small-Area Assessment of a Large,Public Treatment System

Research on drug treatment facility locations has focused narrowly on the issue of geographic proximity to clients. We argue that neighborhood conditions should also enter into the facility location decision and illustrate a formal assessment of neighborhood conditions at facilities in a large, metropolitan area, taking into account conditions clients already face at home. We discuss choice and construction of small-area measures relevant to the drug treatment context, including drug activity, disadvantage, and violence as well as statistical comparisons of clients' home and treatment locations with respect to these measures. Analysis of 22,707 clients discharged from 494 community-based outpatient and residential treatment facilities that received public funds during 1998-2000 in Los Angeles County revealed no significant mean differences between home and treatment neighborhoods. However, up to 20% of clients are exposed to markedly higher levels of disadvantage, violence, or drug activity where they attend treatment than where they live, suggesting that it is not uncommon for treatment locations to increase clients' exposure to potential environmental triggers for relapse. Whereas on average both home and treatment locations exhibit higher levels of these measures than the household locations of the general population, substantial variability in public treatment clients' home neighborhoods calls into question the notion that they hail exclusively from poor, high drug activity areas. Shortcomings of measures available for neighborhood assessment of treatment locations and implications of the findings for other areas of treatment research are also discussed.     

Children with blindness due to retinopathy of prematurity: a population-based study. Perinatal data, neurological and ophthalmological outcome

A population-based group of 27 children with total blindness due to retinopathy of prematurity (ROP), born in Sweden from 1980 to 1990, was examined. They constituted all but two of the total of 29 children with total blindness due to ROP known to the nationai register of visually impaired children when reviewed from 1980 to 1 January 1995. All children had a gestational age of less than 31 weeks and most had had a complicated perinatal period. The retinal disease was discovered late, most often after it had already progressed to bilateral retinal detachment. Repeated vitreoretinal surgery had been performed in most children, but postoperative visual function did not improve. Three-quarters of the group had major neurological impairment (mental retardation, cerebral palsy, or epilepsy) at age 4 to 14 years. There was an impression that extensive ophthalmological efforts delayed nenrodevelopmental assessments and examinations as well as adequate habilitation.     

Metaphit-Induced Audiogenic Seizures in Mice: I. Pharmacologic Characterization

Summary: Metaphit [an analogue of phencyclidine (PCP) with an acylating isothiocyanate group] induced audiogenie clonic to clonic-tonic seizures in mice exposed to audio stimulation 24 h after metaphit administration. The incidence of seizures was reduced by treatment 30 min before audio stimulation with specific PCP-like compounds [5-methyl-10, ll-dihydro-5H-dibenzo(a, d)cyclohepten-5,10-imine maleate (MK-801), and PCP itself], competitive N-methyl-d -aspartate antagonists 2-amino-5- phosphonopentanoic acid (AP-5 and NPC-12626), antiepileptic drugs [phenobarbital (PB), phenytoin (PHT)], and γ-aminobutyric acid (GABA) agonists (muscimol and diazepam). In contrast, when given in conjunction with metaphit, most of these drugs were ineffective in protecting animals from audiogenic seizures 24 h later. Only compounds with long half-lives (t½) such as MK-801, PB, and PHT had a protective effect. High-performance liquid chromatography (HPLC) determination of [³H]MK-801 showed its long-term presence in the brain after intraperitoneal (i.p.) administration of [³H]MK-801. Audiogenic seizures observed 24 h after metaphit administration were potentiated by administration of the GABA antagonist picrotoxin 15 min before audio stimulation, and picrotoxin-induced spontaneous seizures were enhanced by pretreatment (24 h earlier) with a dose of metaphit that in itself did not produce spontaneous seizures at the time of the picrotoxin test. Similar observations were made with N-methyl d -aspartic acid (NMDA) instead of picrotoxin. Thus, an interplay exists between excitatory glutaminergic and inhibitory GABAergic circuitries in the metaphit seizure model.