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Biomedical subjects

W Morrow

Publications and source records attributed to W Morrow.

10 recordsLinked to original sources

A new technique for hard tissues.

Fossil tissues generally require specialized processing. Most thin sectioning techniques yield unstained sections or require unwieldy methods to produce stained sections. I outline here two simple techniques for producing stained, ground, thin sections using readily available Romanowsky-type cytology stains and a urine sediment stain. Results are comparable to hematoxylin and eosin stained specimens.

Animals↗

Breast Cancer Screening Project in Northeast Florida.

The American Cancer Society--Duval Unit, in June, 1987, helped organize a community demonstration screening project involving all hospitals and institutions with mammography units in the area. A Northeast Florida Cooperative Breast Cancer Screening Group was formed comprised of physicians and administrators from each institution. A total of 1,200 women agreed to participate in the project and each underwent complete screening including education, instruction in self-examination, physical examination by a physician and mammography as indicated according to ACS guidelines. Of the study group, 1,032 women were eligible for mammography at a participating center, and 628 (61%) underwent a mammogram at no cost to them as instructed. Twenty four (4%) had definite abnormalities which led to biopsy and seven (1%) of them had malignant lesions. The medical community organized to provide breast cancer screening and follow-up with low-cost mammography.

Adult↗

Localization of terminal complement components S-protein and SP-40,40 in renal biopsies.

The terminal complement complex has been implicated in the development of glomerular injury in both experimental and, indirectly, in human glomerulonephritis. Recent data suggests that the terminal complement complex in human glomerulonephritis may be in the cytolytically inactive SC5b-9 form which also contains S-protein and a recently identified protein, SP-40,40. In this study renal biopsies were examined by immunofluorescence to determine the incidence and inter-relation of deposition of the SC5b-9 components C6, C9, S-protein and SP-40,40. All components of SC5b-9 were found in arteries and arterioles, along the tubular basement membrane and in areas of glomerulosclerosis in all biopsies. This deposition was sometimes associated with C3 but never immunoglobulin deposition and correlated with the degree of renal injury. In addition, in biopsies with glomerular deposition of immunoglobulin and C3, the SC5b-9, components co-localized with the immune deposits. Glomeruli without immune deposits or glomerulosclerosis contained none of the SC5b-9 components. The incidence and pattern of distribution of SP-40,40 was similar to that of S-protein, C6 and C9 in all of cases. These data confirm that the terminal complement complex in the kidney is, at least partly, in the SC5b-9 form both in the specific immune glomerular deposition and in the "non-specific" deposition in areas of renal injury. SP-40,40 is also found in the SC5b-9 complex in all forms of renal disease.

Biopsy↗

Toxaphene inhibition of calmodulin-dependent calcium ATPase activity in rat brain synaptosomes.

Effect of toxaphene on Ca2+-ATPase activity in rat brain synaptosomes was studied in vitro and in vivo. Ca2+-ATPase in calmodulin-depleted synaptosomes was inhibited in vitro to a maximum of about 50% at 150 microM toxaphene. Substrate activation kinetics of Ca2+-ATPase in synaptosomes revealed that toxaphene inhibited the enzyme activity noncompetitively by decreasing Vmax values, without affecting the enzyme-substrate affinity. Toxaphene inhibited the calmodulin activated Ca2+-ATPase activity in a concentration-dependent manner with an IC50 of 10 microM, a concentration at which no significant effect was observed on basal enzyme activity. Nuclear and P2 fraction (synaptosomes) calmodulin levels were reduced significantly in toxaphene-treated rats. The synaptosomal Ca2+-ATPase was also reduced to about 45% in toxaphene-treated rats and the activity was restored to normal levels by the exogenously added calmodulin. These results suggest that toxaphene may cause synaptic dysfunction by interfering with calmodulin and its regulation of neuronal calcium.

Animals↗

In vitro effects of toxaphene on mitochondrial calcium ATPase and calcium uptake in selected rat tissues.

In vitro effects of toxaphene on Ca2+-ATPase activity and 45Ca2+-uptake were studied in mitochondrial fractions of heart, kidney and liver tissues of rat. Mitochondrial fractions were prepared by the conventional centrifugation method. Ca2+-ATPase activity was determined by measuring the inorganic phosphate liberated during ATP hydrolysis. Toxaphene inhibited Ca2+-ATPase in a concentration dependent manner in all the three tissues. Substrate activation kinetics, with heart, kidney and liver tissue fractions, revealed that toxaphene inhibited Ca2+-ATPase activity non-competitively by decreasing the maximum velocity of the enzyme without affecting the enzyme-substrate affinity. Toxaphene also inhibited mitochondrial 45Ca2+-uptake in the three selected tissues in a concentration dependent manner. These results indicate that toxaphene is an inhibitor of mitochondrial Ca2+-ATPase and calcium transport in heart, kidney and liver tissues of rat.

Animals↗