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Biomedical subjects

S Halter

Publications and source records attributed to S Halter.

33 records · Page 2Linked to original sources
PubMed1984

Comparison of histochemical and biochemical assays for estrogen receptor in human breast cancer cell lines.

Two human breast cancer lines, MCF-7 and T47D cells, were investigated for the presence of estrogen receptor (ER) by biochemical and histochemical techniques. Using the dextran-coated charcoal technique and isoelectric focusing, MCF-7 cells were ER positive, and T47D cells were ER negative. Fluorescein conjugates to 17 beta-estradiol by the sixth carbon (17 beta-estradiol-6-carboxymethyloxime:bovine serum albumin: fluorescein isothiocyanate and 17 beta-estradiol-6-iminooxyacetylfluoresceinamine) and by the 17th carbon [N-fluoresceino-N'-[17 beta-(estradiol hemisuccinamide)ethyl]thiourea, 17-FE] were prepared for cytochemical evaluation of the ER status of the two cell lines. The binding affinity of the estradiol conjugates for ER varied, the 17-FE conjugate having the highest affinity of 0.08 relative to 17 beta-estradiol. Following incubation with 10 nM 17-FE, both MCF-7 and T47D cells displayed cytoplasmic and nuclear fluorescent staining. Isoelectric focusing of MCF-7 cytosol incubated in the presence of 10 nM 17-FE revealed binding of the fluorescein conjugate to a protein species which did not bind 17 beta-[3H]-estradiol. Isoelectric focusing of T47D cytosol revealed binding of 17-FE to two protein components, neither one of which showed specific binding of 17 beta-[3H]estradiol. The results suggest different protein binding species for fluoresceinated estradiol conjugates and [3H]estradiol and help to explain reported differences in histochemical and biochemical ER analyses.

Breast Neoplasms↗
PubMedDate not supplied

Noncirrhotic portal hypertension in congenital cytomegalovirus infection.

The majority of infants with cytomegalovirus hepatitis have resolution of the disease with little evidence of fibrosis; there are only rare instances of cirrhosis. We report an infant with cytomegalovirus hepatitis who developed portal hypertension and hematemesis at 3 months of age. Liver biopsy showed resolution of the hepatitis but the presence of noncirrhotic sinusoidal fibrosis. Because of recurrent hematemesis in spite of sclerosing therapy on two occasions, the beta antagonist propranolol was begun. Hepatic wedge pressures before and after treatment with propranolol were 13 and 7 mm Hg, respectively. The findings emphasize: (i) that cytomegalovirus hepatitis may result in noncirrhotic sinusoidal fibrosis and (ii) that propranolol may be beneficial in the management of portal hypertension secondary to noncirrhotic sinusoidal fibrosis.

Cytomegalovirus Infections↗
PubMedDate not supplied

Changes in intestinal electrical activity during ischaemia correlate to pathology.

The gastrointestinal tract possesses an omnipresent electrical slow wave called the basic electrical rhythm (BER). It has been shown that the frequency of the BER falls during intestinal ischaemia. The correlation between changes in the BER and pathology that occur during acute ischaemia are not completely understood. To study this, the electrical activity of the ileum in 14 adult male rabbits was recorded during ischaemia. At baseline, 60, 120 and 210 minutes of ischaemia, segments of bowel were resected for histopathologic evaluation. The BER frequency was determined using the Fast Fourier Transformation (FFT) spectral analysis. The BER amplitude and FFT spectral power were also determined. The results showed significant decrease (p<0.05, Student's T-test) in the BER frequency, amplitude, and spectral power at all time points. Between 60 and 120 minutes, while there was a decrease in BER activity the pathologic grade remained the same (focal loss of surface epithelium). By 210 minutes of ischaemia when the BER could not be recorded, there was diffuse mucosal infarction. The results indicate that changes in the electrical activity of the bowel during acute mesenteric ischaemia occurred prior to the pathologic changes. The presence of electrical activity indicates that there was viable bowel. Thus it should be possible to use recordings of electrical activity to evaluate bowel viability during acute ischaemia.

Animals↗
PubMedDate not supplied

Histopathologic changes during mesenteric ischaemia and reperfusion.

The basic electrical rhythm (BER) of the intestine is known to decrease during mesenteric ischaemia. Some studies have reported the relationship between the BER and the pathologic changes that occur in the bowel during vascular injury. However, these changes have not been completely elucidated. This study describes the histopathologic pattern when the rabbit small intestine was subjected to ischaemia of varying time lengths (30-150 minutes) and subsequent reperfusion for six hours. Intestinal biopsies were taken at baseline, at the end of ischaemia, and at hourly intervals during reperfusion. Microscopic examination of the biopsies revealed evidence of progressive infarction of the mucosa during ischaemia. There was an acute worsening of the pathology during reperfusion, the severity being greater when reperfusion was preceded by longer periods of ischaemia. These changes were statistically significant. The observed pattern in this study shows clearly that reperfusion injury is reflected in the histopathologic response and that this is worse in severity than the response to ischaemia. Studies of longer duration should further clarify the picture during recovery in ischaemia/reperfusion injuries of the bowel.

Animals↗