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Biomedical subjects

S Katz

Publications and source records attributed to S Katz.

At least 451 records · Page 25Linked to original sources
PubMed1978

A new treatment of ischemic bowel disease: steroid delivery via retrograde venous route.

The present therapeutic approach to occlusive mesenteric disease is unable to alter its high mortality and morbidity. We attempted to stabilize the intestinal lysosomal population with steroid prior to revascularization and thus reduce the lysosomal effluent. Steroid delivery during the occlusive period was accomplished via retrograde venous flow in the portal system. During revascularization steroid was further infused via the superior mesenteric artery. Our experimental model compared systemic venous delivery with retrograde portal venous delivery of steroid. Analysis of tissue acid phosphatase levels suggested steroid delivery via retrograde portal venous flow is the most efficient method of lysosomal stabilization.

Animals↗
PubMed1978

The effects of low spinal injury on somatosensory evoked potentials from forelimb stimulation.

Spinal cord transection below C6 in anesthetized cats results in an alteration in the configuration of the SEP following direct or percutaneous stimulation of the median or radial nerves. The most significant alterations were in components occurring at latencies from 40 to 60 msec. The results of these experiments support the general conclusion that the spinal cord and supraspinal structures act as a functional unit and that the SEP is not solely determined by input over segmental pathways In addition, the alteration in the SEP produced by median nerve stimulation following spinal cord injury below C6 may serve clinically as a monitor of events at the site of injury in cases where an SEP from lower limb stimulation is no longer obtainable.

Animals↗
PubMed1978

The effects of interaction between large and small diameter fiber systems on the somatosensory evoked potential.

The effect of interaction between large and small diameter fiber systems on the somatosensory evoked potential (SEP) was studied in anesthetized cats. Activation of large diameter fibers of the peroneal or radial nerves eliminates the late components of the SEP produced by stimulation of all fibers in the contralateral median or radial nerves. The inhibitory effects of a selective conditioning stimulus to the large diameter fibers of the peroneal nerve on the radial nerve evoked SEP was eliminated by bilateral transection of the dorsal column and spino-cervical tracts. However, interaction could still be obtained following transection when both large and small diameter fibers in the peroneal nerve were stimulated. The results of this study support the hypothesis that a correlation exists between activity in different fiber groups in afferent nerves, their conduction pathways through the cord, and the components of the cortical evoked potential.

Afferent Pathways↗
PubMed1978

Computed tomography of solitary pulmonary nodules: experience with scanning times longer than breath-holding.

Thirty-one patients with solitary pulmonary nodules--18 benign and 13 malignant--proven by either tissue diagnosis or prolonged follow-up were evaluated by computed tomography (CT). A device (ACTA scanner 0100) with scanning times greater than breath-holding was used with full understanding of its related limitations. A retrospective study of the CT features of these nodules led us to establish several criteria for benign nodules. CT evidence of calcium is felt to be the most important feature of benignancy. In the absence of calcium, irregular nodule margins, perinodular fibrosis, satellite nodules, and pleural thickening opposite a peripherally situated nodule are helpful to suggest its benign nature.

Humans↗
PubMed1978

Calcium and sodium transport processes in patients with cystic fibrosis. I. A specific decrease in Mg2+-dependent, Ca2+-adenosine triphosphatase activity in erythrocyte membranes from cystic fibrosis patients.

Calcium-ATPase activity (Mg2+-dependent Ca2+-ATPase, ATP phosphohydrolase, EC 3.6.1.3) in erythrocyte membrane preparations from cystic fibrosis (CF) patients was greatly reduced compared to erythrocyte membranes from control subjects. The Km for calcium was found to be similar in the two groups; however, the Vmax, the maximal rate of activation of the Ca2+-ATPase, is reduced by 50% in the erythrocyte membrane preparations of the CF patients (P less than 0.001). In contrast, the Mg2+-ATPase activity of erythrocyte membranes from CF patients was unchanged compared to the control subjects. No difference in the Na+,K+-ATPase activity in erythrocyte membranes from CF patients compared to control patients could be observed. This indicates that the Ca2+-ATPase activity noted in CF erythrocytes is not part of a generalized membrane or membrane-bound enzyme alteration. It remains to be determined whether this alteration in Ca2+-ATPase activity is directly related to a defect in calcium transport in these cells and is a generalized phenomenon in CF present in cell types more directly involved in secretion.

Adolescent↗
PubMed1978

Calcium and sodium transport processes in patients with cystic fibrosis 2. Mg2+- dependent, Ca2+ ATPase activity in fibroblast membrane preparations from cystic fibrosis patients and controls.

Mg2+-dependent Ca2+-ATPase activity was determined in membrane preparations of fibroblasts grown from skin biopsies of cystic fibrosis patients and age-matched controls. This enzyme was stimulated by increasing free calcium concentrations with an apparent Kdiss for calcium of approximately 45 micron. Although there was a great deal of variation in Ca2+-ATPase activity observed between individual strains, there was a significant decrease in the maximal activation of the Ca2+-ATPase in membrane preparations of fibroblasts obtained from cystic fibrosis patients compared to the controls (P less than 0.05). This observation indicates that decreased Ca2+-ATPase activity is a generalized phenomenon in cystic fibrosis found in more than one cell-type. This decrease in Ca2+-ATPase activity may have a number of implications that may explain some of the manifestations of the disease.

Adenosine Triphosphatases↗
PubMed1978

The relationship between physical disability, social perception and psychological stress.

It was hypothesized that the prevailing attitudes towards the disabled would affect their self-concept and thus the impact of the disability as a stress stimulus. This hypothesis was examined in two separate studies. The first study evaluated the impact of disability context on the evaluations of disabled individuals by the non-disabled. It was found that disabled veterans were evaluated significantly higher than individuals disabled in traffic, work accidents, or as a result of polio. In the second study, the self-concept of disabled veterans was compared to the self-concept of work accident disabled. The disabled veterans had significantly higher self-concept than those of the people disabled in work accidents. The results would appear to demonstrate the relationship between the variables presented in the hypothesis.

Adaptation, Psychological↗