The interaction of GABA-A receptors with the serotoninergic system of the brain in regulating the testosterone level by the negative feedback mechanism

A unilateral hemicastration decreased the serotonin and 5-hydroxyindolacetic acid levels in the Wistar rat mediobasal hypothalamus, but not in the midbrain. These neurotransmitters were shown to interact in the process of androgen restoration after the hemicastration. The maximal contribution of GABAergic mechanisms in the testosterone feedback regulation involves the GABA effect via the central GABA-A receptors of the mediobasal hypothalamus' serotoninergic neurons, thus activating the hormone level restoration. The GABA seems to induce a serotonin-independent inhibition of the testosterone level stabilising after hemicastration.     

The response of peripheral blood lymphocytes from lung cancer patients to in-vitro treatment with recombinant interleukin-2

The cytotoxic activity of peripheral blood lymphocytes of 135 lung cancer patients was studied. A wide range of cytotoxicity values was shown--from 0 to 88%. During the randomized investigation of these patients no strong correlation was found between the levels of cytotoxicity and the cancer stages. A certain tendency of increasing the number of patients with weak cytotoxic activity upon progressing disease was followed. The lymphocytes with a strong natural killer activity did not react on the in vitro incubation with interleukin-2. The lymphocytes with a strong was obtained when the lymphocytes with the lowest cytotoxicity levels were incubated with this immunomodulator.     

Effect of arachidonic acid on intracellular calcium stores in human lymphocytes

OBJECTIVE: To assess the risk of probe contamination following transvaginal ultrasonography. DESIGN: Prospective cohort study. SETTING: University Infertility Center. PATIENT(S): Women undergoing transvaginal ultrasonography. INTERVENTION(S): One physician obtained 840 consecutive transvaginal ultrasonograms over nine months. Latex condoms were used to cover the probe. Following examination, the condoms were removed and the probe was wiped with a germicidal disposable cloth and left to air dry for 5 minutes. Condoms were filled with water and examined for leaks. MAIN OUTCOME MEASURE(S): Number of perforations and distance from condom tip. RESULT(S): Seventeen (2%) of 840 condoms leaked. The mean distance from the tip to the point of leakage was 10.6 cm +/- 2.8 (mean +/- SD; range, 7-14). Sixty-five percent of the leaks were < or = 10 cm from the tip. In several instances, two leaking condoms were found within a few examinations of each other. No visual contamination of the probe was noted. CONCLUSION(S): Although only 2% of condoms leaked, 65% were at distances that could have led to probe soiling intravaginally. While no body fluids were grossly visible, microscopic contamination was still possible. Since perforations were noted in close, and even consecutive scans, this study underscores the need for routine probe disinfection between examinations.     

13C and 15N-chemical shift anisotropy of ampicillin and penicillin-V studied by 2D-PASS and CP/MAS NMR

The principal values of the chemical shift tensors of all 13C and 15N sites in two antibiotics, ampicillin and penicillin-V, were determined by 2-dimensional phase adjusted spinning sideband (2D-PASS) and conventional CP/MAS experiments. The 13C and 15N chemical shift anisotropies (CSA), and their confidence limits, were evaluated using a Mathematica program. The CSA values suggest a revised assignment of the 2-methyl 13C sites in the case of ampicillin. We speculate on a relationship between the chemical shift principal values of many of the 13C and 15N sites and the beta-lactam ring conformation.     

Molecular biology of colorectal cancer and clinical consequences for colorectal cancer syndromes

Because of the accomplishments in biotechnical research in the past few decades our knowledge about the molecular mechanisms of carcinogenesis has grown rapidly. Colorectal cancer has been one of the most intensively investigated tumor entities, and it seems to be well established that colorectal tumor growth is associated with an accumulation of acquired somatic mutational events in tumor suppressor genes and oncogenes. Recent progress in our understanding of the molecular basis of the most prevalent colorectal cancer syndromes, such as hereditary nonpolyposis colorectal cancer (HNPCC) and familial adenomatous polyposis (FAP), is reflected by modifications in diagnosis and therapy. Identification and characterization of the causative genes for these colorectal cancer syndromes have enabled precise presymptomatic detection of mutations in individuals who bear an a priori risk of about 50% of developing colorectal cancer. Genotype-phenotype correlations might further increase the clinical management of hereditary colorectal cancer. Even though developments in cancer research are restricted to the minority of individuals with hereditary cancer syndromes, growing knowledge about the effect of low penetrance variations in tumor suppressor genes may affect the diagnosis and therapy of sporadic colorectal cancer.     

配合智能手机等便携应用要求及技术趋势的电源管理方案

本文探讨了安森美半导体针对便携应用提供的各种高性能、高能效电源管理方案,并提供了选择适合的元器件方案。     

智能LED街灯与楼宇照明通信、控制及保护方案

安森美半导体的先进通信、传感器、KNX收发器及保护解决方案,为构建联网的LED街灯智能控制系统或是智能楼宇控制系统提供了有力的条件。本文对这些方案给予介绍。     

应用于智能电表各功能模块的安森美半导体方案概览

本文介绍了应用于智能电表的安森美半导电源管理、通信、存储器、时钟、接口、保护/滤波等各种功能模块的方案。