Sources of GABAergic input to the inferior colliculus of the rat

We have studied the GABAergic projections to the inferior colliculus (IC) of the rat by combining the retrograde transport of horseradish peroxidase (HRP) and immunohistochemistry for gamma-amino butyric acid (GABA). Medium-sized (0.06-0.14 microliter) HRP injections were made in the ventral part of the central nucleus (CNIC), in the dorsal part of the CNIC, in the dorsal cortex (DCIC), and in the external cortex (ECIC) of the IC. Single HRP-labeled and double (HRP-GABA)-labeled neurons were systematically counted in all brainstem auditory nuclei. Our results revealed that the IC receives GABAergic afferent connections from ipsi- and contralateral brainstem auditory nuclei. Most of the contralateral GABAergic input originates in the IC and the dorsal nucleus of the lateral lemniscus (DNLL). The dorsal region of the IC (DCIC and dorsal part of the CNIC) receives connections mostly from its homonimous contralateral region, and the ventral region from the contralateral DNLL. The commissural GABAergic projections originate in a morphologically heterogeneous neuronal population that includes small to medium-sized round and fusiform neurons as well as large and giant neurons. Quantitatively, the ipsilateral ventral nucleus of the lateral lemniscus is the most important source of GABAergic input to the CNIC. In the superior olivary complex, a smaller number of neurons, which lie mainly in the periolivary nuclei, display double labeling. In the contralateral cochlear nuclei, only a few of the retrogradely labeled neurons were GABA immunoreactive. These findings give us more information about the role of GABA in the auditory system, indicating that inhibitory inputs from different ipsi- and contralateral, mono- and binaural auditory brainstem centers converge in the IC.     

Detection of antibiotic resistance in Enterococcus sp. Comparison of GPS-TA (BioMérieux-Vitek), Uniscept MIC-3 (bioMérieux-Vitek) and conventional methods

BACKGROUND: The treatment of severe enterococcus infections requires synergism of a beta-lactamic or glycopeptide and a aminoglycoside, but when resistance to first one or high-level resistance to aminoglycosides are present, synergism would be lost. We compared the adequacy of two commercially available systems to detect antibiotic resistance. METHODS: We studied 158 isolates of Enterococcus sp., with high-level resistance to gentamicin (40 isolates) and streptomycin (89 isolates), resistance to ciprofloxacin (34 isolates), resistance to ampicillin (7 isolates) and with intermediate susceptibility to vancomycin (3 isolates). No one was beta-lactamase producer by Cefinase disk method. We use disk diffusion as reference technique to detect high-level streptomycin resistance. The susceptibility to the remainder antibiotics was studied by agar dilution method, according to NCCLS. We studied the accuracy of GPS-TA cards and Uniscept MIC-3 in relation to the degree of agreement with conventional means, following FDA criteria. RESULTS: Essential agreement for MIC was less than 90 with MIC-3 for ampicillin (81.5%) and ciprofloxacin (71.3%). Categorical agreement rate was less than 90% (76.4%) and major error rate was higher than 3% (10.9%) with the use of MIC-3 for ciprofloxacin. Very major errors for ampicillin, vancomycin and ciprofloxacin were not produced by any system. The very major error rates for high level resistance to gentamicin and streptomycin with GPS-TA card were 5 and 15.7%, respectively. CONCLUSIONS: We do not recommend the use of the Uniscept MIC-3 panel with visual reading to detect susceptibility to ciprofloxacin. Detection of high levels of aminoglucoside resistance by GPS-TA card should be supplemented with conventional techniques because of the high rate of major error. Due to the low number of strains that have been studied, we can not assure the suitability of these systems to detect ampicillin or vancomycin resistance.     

Dyslipemia in a population with a high rate of cardiovascular mortality

The activity of N-acetyltransferase (NAT) and catalase was measured in the tissues of placenta, full venous blood and full umbilical cord blood in 141 complicated pregnancies. The control group consisted of 34 physiological pregnancies. The enzymes activity was marked by use of biochemical methods. It has been shown that NAT and catalase is the most active in the group of physiological pregnancies. The decrease of NAT and catalase in venous and umbilical cord blood is correlated with the decrease of the activity these enzymes in placenta.     

Nedocromil sodium in treatment of bronchial asthma

Clinical study on efficiency of the nedocromil sodium (Tilade, Fisons) was performed in 20 patients with atopic and nonatopic bronchial asthma. The drug was administrated in dose of 8 mg per day for 2 months which allowed to renounce regular using of Beclocort forte after 7 days of the treatment. In both types of bronchial asthma the positive effect of nedocromil sodium was confirmed, causing increase of pulmonary ventilation and decrease of bronchial hyperactivity. Especially profitably effect was noticed in atopic bronchial asthma in which statistically important increase of peak expiratory flow (PEF) was obtained and decrease of bronchial hyperreactivity by PC20 for histamine was observed (p < 0.05). Mentioned above spirometric parameters did not differ in statistically important pattern in patients with nonatopic bronchial asthma, when Beclocort forte group with Tilade group compared. Neither important differences in general number of cells nor percentage composition of cell smears were observed in bronchoalveolar lavage fluid.     

叠轧薄板轧机轧辊轴承的改进

本文针对安阳钢铁公司薄板厂叠轧薄板轧机轧辊轴承轴瓦容易损坏、沥清润滑油冒烟起火这一问题，通过实验方法，找出了原因，并对大铜瓦进行了改进，取得了良好效果。     

淀积条件对GDa—SiNx薄膜电学特性的影响

本文讨论了用辉光放电法制备氮化硅薄膜时衬底温度、射频功率和气体流量比对薄膜的电导率、介电常数和击穿强度的影响。通过优化生长条件，制备了优质非晶氮化硅薄膜，其介电常数为７．５、击穿强度为５．５ＭＶ／ｃｍ、电导率为１０－１３（Ωｃｍ）－１。     

Use of Explosives on The Moon

The utilization of explosives for excavation on the lunar surface is under serious consideration as a part of the design for construction of temporary and permanent bases. An excavation research program has shown that small‐scale explosives blasting in a lunar‐soil simulant will greatly reduce the digging forces required for scoop and dragline excavators. Some crater‐blasting parameters were determined for the lunar soil simulant at one Earth gravity and at 10 Earth gravities using a centrifuge. The size of the craters produced at 10 Earth gs matched those formed at one earth g by scaling according to the weight of the explosive. These data can be applied to explosive‐excavation problems such as habitat construction, burial of nuclear power sources, and the rapid construction of shelters remote from the main base to shield against solar‐flare activity.     

钨铜合金药型罩及其性能

钨铜合金药型罩的应用可以提高射流对均质钢靶的侵彻能力.这一提高得益于射流密度的提高以及断裂时间的延长. 本文对钨铜合金射流及其断裂形态通过X光照像进行了研究.它的旋转效应及其炸高特性也进行了实验研究. 钨铜合金药型罩的威力实验在φ30 mm的破甲弹上进行.在相同装药条件下与紫铜罩相比,威力提高20～30%.