Anatomy of the lumbar spine

The macroscopic courses of the posterior primary rami in the lumbar spine are described and illustrated from fresh cadaver dissections.     

Relationship between plasma phospholipid transfer protein activity and HDL subclasses among patients with low HDL and cardiovascular disease

NK lysin is a 9-kDa polypeptide that was originally isolated from porcine intestinal tissue based on its antibacterial activity. It is produced by cytolytic lymphocytes and is cytolytic against a number of different types of tumor cells. Here we report the binding of NK lysin to lipopolysaccharide (LPS) and its anti-LPS activity. NK lysin binds to matrix-coated LPS from Escherichia coli, Pseudomonas aeruginosa, and different strains of Salmonella enterica. Lipid A and polymyxin B inhibited the binding, demonstrating a preferential interaction of NK lysin with the lipid part of LPS. Chromium-labeled lymphoma cells were lysed by NK lysin, and LPS dose-dependently inhibited the cytolysis at equimolar amounts. In the same manner, NK lysin inhibited certain LPS-stimulated effects on mouse bone marrow cells as well as LPS binding to mouse granulocytes. These results suggest that NK lysin may be a another natural LPS-binding protein from lymphocytes that may participate in the endogenous defense response associated with elevated concentrations of LPS.     

Light-dependent changes in outer segment free-Ca2+ concentration in salamander cone photoreceptors

Simultaneous measurements of photocurrent and outer segment Ca2+ were made from isolated salamander cone photoreceptors. While recording the photocurrent from the inner segment, which was drawn into a suction pipette, a laser spot confocal technique was employed to evoke fluorescence from the outer segment of a cone loaded with the Ca2+ indicator fluo-3. When a dark-adapted cone was exposed to the intense illumination of the laser, the circulating current was completely suppressed and fluo-3 fluorescence rapidly declined. In the more numerous red-sensitive cones this light-induced decay in fluo-3 fluorescence was best fitted as the sum of two decaying exponentials with time constants of 43 +/- 2.4 and 640 +/- 55 ms (mean +/- SEM, n = 25) and unequal amplitudes: the faster component was 1.7-fold larger than the slower. In blue-sensitive cones, the decay in fluorescence was slower, with time constants of 140 +/- 30 and 1,400 +/- 300 ms, and nearly equal amplitudes. Calibration of fluo-3 fluorescence in situ from red-sensitive cones allowed the calculation of the free-Ca2+ concentration, yielding values of 410 +/- 37 nM in the dark-adapted outer segment and 5.5 +/- 2.4 nM after saturating illumination (mean +/- SEM, n = 8). Photopigment bleaching by the laser resulted in a considerable reduction in light sensitivity and a maintained decrease in outer segment Ca2+ concentration. When the photopigment was regenerated by applying exogenous 11-cis-retinal, both the light sensitivity and fluo-3 fluorescence recovered rapidly to near dark-adapted levels. Regeneration of the photopigment allowed repeated measurements of fluo-3 fluorescence to be made from a single red-sensitive cone during adaptation to steady light over a range of intensities. These measurements demonstrated that the outer segment Ca2+ concentration declines in a graded manner during adaptation to background light, varying linearly with the magnitude of the circulating current.     

Primary aortic mural thrombus: presentation and treatment

Schizophrenic patients are extremely heavy tobacco smokers. However, a lower incidence of lung cancer in schizophrenic patients has been observed in comparison to other heavy smokers. Nicotine increases the proliferation of pulmonary neuroendocrine tissue, causing the release of a bombesin-like peptide. Thus, bombesin-like peptide levels in urine may be an indicator of precancerous, cigarette-induced lung damage. Bombesin-like peptide levels of 10 schizophrenic smokers and 11 schizophrenic nonsmokers were compared to those of nonschizophrenic subjects matched for age and pack-years of smoking. The nonschizophrenic smokers showed the expected increase in urinary bombesin-like peptide levels, as compared to nonschizophrenic nonsmokers. Schizophrenic patients had lower bombesin-like peptide levels independent of smoking effects. The mechanism of the difference in bombesin-like peptide levels between schizophrenic patients and nonschizophrenic subjects is unknown, but one possibility involves alteration in the alpha 7-nicotinic acetylcholine receptor, which mediates the growth of some neuroendocrine cell lines in vitro.     

Suppression of tumorigenicity of rat liver epithelial tumor cell lines by a putative human 11p11.2-p12 liver tumor suppressor locus

We have previously identified and mapped a locus within human chromosome 11p11.2-p12 that suppresses the tumorigenic potential of a rat liver tumor cell line (termed GN6TF) which contains well defined chromosomal aberrations involving rat chromosomes 1, 4, 7, and 10. In the present study, we investigated the potential of this human 11p11.2-p12 liver tumor suppressor locus to suppress the tumorigenic potential of two other rat liver tumor cell lines (GN3TG and GP10TA) following microcell-mediated introduction of human chromosome 11. These tumor cell lines are aneuploid and contain chromosomal abnormalities that are similar to the GN6TF tumor line. The tumorigenic potential and other phenotypic characteristics of GN3TG-11neo and GP10TA-11neo microcell hybrid (MCH) cell lines were variable, and dependent upon the status of the introduced human chromosome 11. MCH cell lines that retained the region of 11p11. 2-p12 delineated by microsatellite markers D11S1385 and D11S903 exhibited suppression of tumorigenicity in vivo (decrease in tumorigenicity and/or elongation of latency), whereas, the tumorigenic potential of one MCH line that lacked markers in this region of human 11p11.2-p12, but retained flanking markers, was not changed from that of the parental tumor cell line. The chromosomal interval between microsatellite markers D11S1385 and D11S903 encompasses the previously localized minimal liver tumor suppressor region, suggesting that a common locus is responsible for tumor suppression among the rat liver tumor cell lines examined. The results of the present study have verified the presence of a liver tumor suppressor locus within human 11p11.2-p12, and have identified a substantial number of microsatellite markers that are closely linked to this tumor suppressor region. These chromosomal markers will facilitate positional cloning of candidate genes from this region, and may prove useful for determining the involvement of this locus in the pathogenesis of human liver cancer.