Attenuation of the efficacy of vasoconstrictive effects in rats after a 3-week suspension

Male Wistar rats were maintained suspended by the skin of posterior third of the back for three weeks. Constrictive reactions to norepinephrine and irritation of sympathetic nerves were studied with hindlimb vessels perfused with physiological solution at constant pressure. Perfusion pressure was stabilized at 40, 80, and 120 mmHg. During complete relaxation of the vascular smooth muscles the volumetric rate of perfusate flow in experimental animals was reduced comparing with their controls. This implies narrowing of the lumen in resistive vessels caused by suspension. Following suspension, reaction of rat's nerves to irritation was markedly lower than in the control at all levels of pressure. At 40 mmHg vessels of the suspended rats were more sensitive to norepinephrine; however, at 80 and 120 mmHg vascular sensitivity to the agent was reduced in the test group vs. the control. Suppression of the reactivity of hindlimb vessels to the constrictive agents may be one of the causes of failure of mechanisms of blood redistribution following prolonged gravitational deloading.     

Sexual function in patients with disseminated sclerosis. A 5-year follow-up study

Sexual dysfunction is known to occur in multiple sclerosis (MS). The purpose of the study is to describe the change in sexual function and symptoms in a five year follow-up study. Forty-nine patients (27 females, 22 males) with definite MS were interviewed and examined. The number of patients with sexual dysfunction increased significantly (p = 0.004) and involved females and males equally. Males usually had one or two symptoms, while females frequently had two or more symptoms. It is concluded that the risk of sexual dysfunction increases over time. Further studies concerning treatment possibilities are needed.     

Immunohistochemical localization of netrin-1 in the embryonic chick nervous system

Netrin-1 has profound in vitro effects on the growth properties of vertebrate embryonic axons. In addition, netrin-1 mRNA is found in the floor plate of the embryonic nervous system, an intermediate target of many axons, including commissural axons that are affected by netrin-1 in vitro. Moreover, genetic studies of netrin-1 homologs in Caenorhabditis elegans and Drosophila implicate these proteins in commissure formation. We raised polyclonal antisera that recognize chick netrin-1 in fixed tissue sections. The antisera were used to immunohistochemically map netrin-1 in the embryonic spinal cord, brain, and retina. The relationship between netrin-1 localization and the growth of pioneering axons suggests roles for netrin-1 in the regulation of circumferential, commissural, and longitudinal axon growth in the spinal cord and brain. The data also suggest that the primary or sole effect of netrin-1 on pioneering spinal cord commissural axons is haptotactic. Furthermore, the pattern of netrin-1 localization raises the possibility that this protein helps mediate neuronal migration in the spinal cord, brain, and retina.     

Improved identification of mycobacteria by using the microbial identification system in combination with additional trimethylsulfonium hydroxide pyrolysis

The MIDI automated Microbial Identification System (MIS) uses gas chromatography (GC) analysis of whole-cell fatty acid methyl esters (FAMEs) between 9 and 20 carbons in length to characterize a wide range of bacterial genera and species, including mycobacteria. Mycolic acid cleavage products (MACPs) with chain lengths of C22 to C26 are not released by MIDI sample preparation of mycobacteria. Therefore, the MIS library search report often matches several mycobacterial species without any significant difference in the similarity indices. The problem is solved by adding trimethylsulfonium hydroxide (TMSH) instead of sodium sulfate in the last step of sample preparation, thus allowing the identification of MACPs in addition to FAMEs. Only one GC run parameter has to be changed: the temperature program must be extended from 260 to 310 degrees C. The MIS library search report for the identification of bacteria is not disturbed by TMSH. The combination of conventional library search report with the information of typical MACP patterns yields significantly better discrimination of mycobacterial species than the MIDI method allows.     

Neonatal vitamin K administration and childhood cancer in the north of England: retrospective case-control study

OBJECTIVE: To explore the possible association between intramuscular vitamin K given to neonates and the subsequent development of childhood cancer. DESIGN: Retrospective case-control study on the basis of hospital records. SETTING: The former Northern Health region of England. SUBJECTS: 685 children who were born and lived in the region and who developed cancer before their 15th birthday, and 3442 controls also born between 1960 and 1991 and matched only for date and hospital of birth. The notes of a further 701 index cases were untraceable. MAIN EXPOSURE MEASURE: Administration of intramuscular vitamin K versus no exposure to vitamin K. RESULTS: There was no association between the administration of vitamin K and the development of all childhood cancers (unadjusted odds ratio 0.89; 95% confidence interval 0.69 to 1.15) or for all acute lymphoblastic leukaemia (1.20; 0.75 to 1.92), but there was a raised odds ratio for acute lymphoblastic leukaemia developing 1-6 years after birth (1.79; 1.02 to 3.15). No such association was seen in a separate cohort-based study not dependent on case note retrieval in which the rates of acute lymphoblastic leukaemia in children born in hospital units where all babies received vitamin K were compared with those born in units where less than a third received prophylaxis. CONCLUSIONS: It is not possible, on the basis of currently published evidence, to refute the suggestion that neonatal intramuscular vitamin K administration increases the risk of early childhood leukaemia. Any association may have been masked in earlier studies that did not use controls matched for time and locality by other unidentified factors affecting the spatiotemporal variations in incidence of leukaemia.     

Differential nuclear matrix protein expression in prostate cancers: correlation with pathologic stage

PURPOSE: Nuclear Matrix Proteins (NMP) have been shown to be tissue and cell-type specific. Several unique NMPs have been investigated in various cancerous tissues, including prostate, bladder and kidney, and some are presently utilized as tumor markers. This study was aimed at characterizing the differential NMP expression in the pathologically more aggressive prostate cancers. METHODS: High resolution two-dimensional gel electrophoresis and silver staining was used to elucidate the NMP distribution of fresh prostate cancer nuclei, obtained from 39 radical prostatectomy specimens, surgically removed from men with clinically localized prostate cancer. Based on the final pathological grading, specimens were grouped according to predicted prognosis: poor--with seminal vesicle (SV) or lymph node (LN) involvement or established capsular penetration (ECP) with gleason score >7; intermediate--organ confined (OC) or focal capsular penetration (FCP) with gleason score 7 or ECP with gleason score 6; and good--with OC or FCP and gleason score <7. RESULTS: A specific charged protein (YL-1) of molecular weight 76 kD and isoelectric range 6.0-6.6 was found to be consistently present in 19 of 19 aggressive cancers. It was present only in 1 of 10 in the group with good prognosis and weakly positive in 9 of 10 in the intermediate group. CONCLUSIONS: Within this preliminary study, the expression of YL-1 appears to be related to aggressive prostate cancer, suggesting a potential marker of poor prognosis for clinically localized prostate cancer. Further characterization of the identity and function of this NMP is needed to fully ascertain its clinical potential.     

Co60 gamma-ray sensitivity of a series of strains of Saccharomyces cerevisiae yeasts bearing different mutations. I. Radiosensitivity of haploid strains

Sensitivity to gamma-rays Co60 of haploid strains of Saccharomyces cerevisiae carrying ade1-6 mutations and dominant, semidoninant and recessive suppressors was investigated. It was shown that 3 out of 4 studied strains with ade1-6 mutation had reliable increased radioresistance. The increased radioresistance was observed also in strains carrying, beside ade1-6 mutation, dominant and semidominant suppressors. However the strain carrying a recessive suppressive mutation turned to be radiosensitive. A conclusion is drawn that rediosensitivity of yeast cells can be influenced by different mutations affecting the process of cell metabolism.