Tetrasomy 21 in megakaryoblastic leukemia

The precise localization of a membrane-bound, arginine-specific mono-ADP-ribosyltransferase (mADP-RT) was assessed in rabbit skeletal muscle by studying membrane fractions isolated by successive sucrose density gradient centrifugations. mADP-RT activity was 10-fold enriched in sarcolemmal and T-tubular membranes. The catalytic activity, determined in preparations with mainly right-side-out vesicles, was found to be on the cytoplasmic face. As revealed by SDS-PAGE and autoradiography endogenous mADP-RT activity labeled several proteins in the range between 15 kDa and 250 kDa. T-tubules contained the highest number of [32P]ADP-ribose-labeled proteins.     

Increased oxidant resistance of alveolar macrophages isolated from rats repeatedly exposed to cadmium aerosols

This study investigated potential mechanisms of oxidant resistance in alveolar macrophages (AM) isolated from Lewis rats exposed repeatedly to cadmium aerosols. Macrophages from Cd-adapted animals significantly greater resistance to oxidant-induced cytotoxicity than control cells when challenged with hydrogen peroxide in vitro. Elevations in glutathione peroxidase and glutathione reductase activities were associated with increased oxidant tolerance but catalase activity was unchanged. Metallothionein (MT) expression (protein and mRNA) was dramatically up-regulated in response to in vivo Cd exposure. A study using immunocytochemistry and in situ hybridization techniques revealed significantly heterogeneity in the expression of metallothionein by AMs. The percentage of AMs positive for MT (protein and mRNA) and the degree of MT expression within individual cells increased in response to additional Cd exposures. A putative state of activation was suggested by differences in size and number of inclusion bodies in macrophages from Cd-adapted animals and by secretion of a cytokine with interleukin-1-like characteristics. In summary, AMs from Cd-adapted animals are distinguished from control cells with respect to: (1) increased oxidant resistance, (2) secretion of cytokines, (3) elevations in enzymes associated with glutathione metabolism, and (4) up-regulation in metallothionein expression.     

Assessment information for predicting upcoming change in language production

Initial language assessments are used not only to determine the presence of a language problem and establish eligibility for intervention, but also to provide information about a child's readiness for immediate change in language growth. This study explored static assessment profiling (specific variables and discrepancies in performance) and dynamic assessment results to determine their relative effectiveness for predicting immediate change. Correlation data were used to examine how well each assessment measure predicted upcoming language production changes for children with specific expressive language impairment. Results indicated that dynamic assessment outcomes were most highly correlated with immediate language growth, followed by discrepancy in receptive and expressive language age. Findings are discussed in terms of their clinical and theoretical importance.     

Effects of prenatal androgenization, melengestrol acetate, and Synovex-H on feedlot performance, carcass, and sensory traits of once-calved heifers

Three studies were designed using a 2 x 2 factorial arrangement of treatments within each experiment to evaluate the effects of various management techniques on growth and carcass traits of once-calved heifers. In Exp. 1, 33 yearling (16 control [C] and 17 prenatally androgenized [PA]) and 39 once-calved (20 C and 19 PA) nonpregnant heifers were used to evaluate the effects of age and PA. Once-calved heifers were approximately 31 kg heavier (P < .03) on-test, initially consumed 11% more (P < .01) DM, and gained 11% faster (P < .08), but had similar (P = .44) gain to feed ratios (.138 vs. .131) as yearlings. Growth performance was not affected by PA. The yearling and once-calved heifers were then slaughtered at approximately 707 and 1,080 d of age, respectively. Despite maturity differences (P < .01), marbling scores (P = .26) and percentage of choice carcasses (P = .27) were similar. However, on the basis of newly accepted grading changes, percentage of once-calved heifer carcasses grading choice decreased from 57.3 to 34.4%. Organoleptic properties did not differ. Experiments 2 and 3 were then conducted to evaluate effects of commercially available products (melengestrol acetate [MGA] and Synovex-H) on feedlot characteristics of heifers following weaning of their first calf. In Exp. 2, 48 once-calved Simmental-based heifers were fed during the summer to a constant compositional fat thickness of .8 cm. Experiment 3 was conducted in the late fall and early winter, during which 52 moderately sized heifers were fed for 116 d postweaning and slaughtered. Performance of heifers in Exp. 2 was not affected by MGA. However, heifers fed MGA in Exp. 3 gained 9% faster (P < .05) than controls. In Exp. 2, Synovex-H tended to improve ADG (P < .09) and feed efficiency (P < .07), but did not affect performance in Exp. 3. Most carcass traits were not affected by either treatment. Nonpregnant, once-calved heifers seem to have a large capacity for efficient weight gain as compared with yearling heifers. However, hormonal compounds, such as testosterone propionate provided pre- or postnatally (Synovex-H), and MGA do not appear to provide the consistent, positive responses often seen with younger, more typical feedlot heifers.     

Recurrent familial intrahepatic cholestasis in the Faeroe Islands. Phenotypic heterogeneity but genetic homogeneity

Recurrent familial intrahepatic cholestasis is an autosomal recessive disorder characterized by episodes of severe pruritus and jaundice lasting for weeks to months without extrahepatic bile duct obstruction. Symptom-free intervals may last for months to years, and chronic liver damage does not develop. We recently studied four of the five patients from the Faeroe Islands described by us 30 years ago (one had recently died) and an additional five patients that were identified after the initial report. The episodes of cholestasis were more frequent and severe in patients with early onset, but tended to reduce in frequency with age. The youngest patient, aged 25 years, who had had 16 episodes each lasting about 6 months, had a liver transplant after which no further episodes were recorded (1 year after surgery). Signs of chronic liver disease were absent in all patients. The FIC1 gene was investigated for mutations in the surviving patients. A single mutation (I661T) was found on both chromosomes in all nine patients, indicating that they are genetically identical for the disease-causing defect. Nevertheless, considerable differences among patients were observed clinically.     

负温混凝土早期结构损伤程度研究

本文研究了-5℃、-10℃、-15℃及两种自然变负温( 1℃～-6℃、-5℃～-15℃)养护条件下及转正温标准养护后混凝土的动弹性模量与抗压强度的变化规律。试验结果表明：与标准养护的混凝土的动弹模增长规律相比较。可以利用动弹性模量随时间变化规律确定不同负温下混凝土的损伤程度;与不同负温养护温度下混凝土的强度增长规律相比较。二者的发展规律一致。但对一次冻结模式与多次冻结模式的负温混凝土。二者发展规律存在一定差异。     

L-ornithine vs. L-ornithine-L-aspartate as a treatment for hyperammonemia-induced encephalopathy in rats

BACKGROUND/AIMS: The effect of L-ornithine (ORN) and L-ornithine-L-aspartate (OA) therapy on "extracerebral" nitrogen metabolism, brain metabolism and neurotransmission has been investigated in portacaval shunted rats with hyperammonemia-induced encephalopathy. METHODS: One day before ammonium-acetate infusion, a portacaval shunt was performed in three experimental groups: 1-control rats, 2-ORN-treated rats and 3-OA-treated rats. Ammonium-acetate was given as an intravenous bolus injection (0.4 mmol.kg bw-1) followed by a constant infusion (1.9 mmol.kg bw-1.h-1) so that steady-state blood ammonia concentrations (500-800 microM) were obtained in the course of 5 h. After 1 h, ammonium-acetate infusion, either L-ornithine or L-ornithine-L-aspartate, was infused for the next 4 h (3.0 mmol.kg bw-1.h-1) in the treated groups. The following parameters were measured: clinical grade of encephalopathy, EEG activity (n = 10 - 20/group), amino acids in plasma (n = 10 - 20/group) and brain dialysate (n = 5 - 9/group), and brain metabolites obtained by in vivo cerebral 1H-MRS (n = 4 - 6/group). RESULTS: ORN and OA treatment resulted in significantly lower blood (34% and 39%) and brain (42% and 22%) ammonia concentrations, significantly higher urea production (39% and 86%) and significantly smaller increases in brain glutamine and lactate concentrations than in controls. These changes were associated with a significantly smaller increase in clinical grade of encephalopathy in ORN- and OA-treated rats, and a significant improvement in EEG activity in ORN-treated rats. OA-treated rats showed a significant increase in aspartate and glutamate concentrations in brain dialysate. CONCLUSIONS: The beneficial effects of both treatments on the manifestations of hyperammonemia-induced encephalopathy can be explained by a reduction in blood and brain ammonia concentrations. It is suggested that when OA is administered, the effect of ornithine is partly counteracted by aspartate, inducing high brain extracellular concentrations of the two excitatory amino acids glutamate and aspartate, and perhaps causing overstimulation of NMDA receptors.