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Biomedical subjects

L Strauss

Publications and source records attributed to L Strauss.

88 records · Page 5Linked to original sources
PubMed1967

Ultrastructure of molar trophoblast. Observations on hydatidiform mole and chorioadenoma destruens.

The ultrastructure of molar trophoblast is described in hydatidiform mole and chorioadenoma destruens. Villous molar trophoblast exhibits only minor deviations from normal early villous trophoblast. Invasive trophoblast of chorioadenoma destruens shows features of more-active cell growth, multiplication, differentiation, and degradation. Evidence for evolution of highly differentiated syncytial trophoblast via intermediate stages from primitive undifferentiated cytotrophoblast is confirmed. Cytoplasmic inclusions resembling virus-like particles, observed in chorioadenoma destruens, have not been hitherto described in normal or pathologic trophoblast.

Chorionic Villi↗
PubMedDate not supplied

Benign pleomorphic adenoma of the larynx. A case report.

Minor salivary gland tumors of the larynx are relatively rare. Morphologically the majority of them are adenoid cystic carcinomas and the overwhelming location is the subglottic larynx. Benign pleomorphic adenomas are rare minor salivary gland tumors of the larynx which usually occur at the glottic and subglottic levels. We present only the sixth case of a supraglottic benign pleomorphic adenoma that we could find in the literature. A preoperative laryngogram localized the tumor to the supraglottic larynx and the intact mucosa suggested a specific differential diagnosis. The tumor was removed by a lateral pharyngotomy with retention of good laryngeal function. The relatively asymptomatic presentation of our case is a somewhat unusual finding which, however, was previously noted in similar case reports.

Adenoma, Pleomorphic↗
PubMedDate not supplied

Attenuation changes of the normal and ischemic canine kidney. Dynamic CT scanning after intravenous contrast medium bolus.

The potential of CT scanning to explore total and regional renal blood flow was evaluated in a dog model with unilateral renal artery stenosis (n = 7, reduction of renal blood flow: 32-75% of base line flow). Attenuation versus time curves were generated for the renal cortex and medulla, as well as for the aorta and renal vein. A fast CT scanner was used which allowed for up to 24 scans/minute at the same level (slice thickness: 10 mm). A total of 10 ml contrast medium was injected into a peripheral vein for each scan series taken. During baseline conditions, the curve of the renal cortex and medulla demonstrated 2 peaks. The first peak was mainly related to early vascular enhancement, whereas the second peak corresponded mainly to the appearance of contrast medium in the distal convolutes and collecting ducts. Ischemia of the kidney resulted in a reduction of the first peak and a flattening of the leading edge slope. Transport of contrast medium through the extravascular compartments of the kidney was delayed during ischemia. Relative renal blood flow was obtained from the CT data by dividing peak enhancement by rise-time as assessed from the cortical curve. All measurements were related to baseline flow and validated by flow measurements using radioactive labeled microspheres (n = 5). Correlation was found to be r = 0.97.

Animals↗
PubMedDate not supplied

Phytoestrogens: potential endocrine disruptors in males.

Exposure to diethylstilbestrol (DES) induces persistent structural and functional alterations in the developing reproductive tract of males. It is possible that xenoestrogens other than DES alter sexual differentiation in males and account for the increasing incidence of developmental disorders of the reproductive tract in men and wild animals. Phytoestrogens (coumestans, isoflavonoids, flavonoids, and lignans) present in numerous edible plants are quantitatively the most important environmental estrogens when their hormonal potency is assessed in vitro. They exert their estrogenic activity by interacting with estrogen receptors (ERs) in vitro. They may also act as antiestrogens by competing for the binding sites of estrogen receptors or the active site of the estrogen biosynthesizing and metabolizing enzymes, such as aromatase and estrogen-specific 17 beta-hydroxysteroid oxidoreductase (type 1). In theory, phytoestrogens and structurally related compounds could harm the reproductive health of males also by acting as antiestrogens. There are very little data on effects of phytoestrogens in males. Estrogenic effects in wildlife have been described but the evidence for the role of phytoestrogens is indirect and seen under conditions of excessive exposure. In doses comparable to the daily intake from soybased feed, isoflavonoids such as genistein were estrogen agonists in the prostate of adult laboratory rodents. When given neonatally, no persistent effects were observed. In contrast, the central nervous system (CNS)-gonadal axis and the male sexual behavior of the rat appear to be sensitive to phytoestrogens during development. The changes were similar but not identical to those seen after neonatal treatment with DES, but higher doses of phytoestrogens were needed.

Animals↗
PubMedDate not supplied

Constant expression of cyclooxygenase-2 gene in prostate and the lower urinary tract of estrogen-treated male rats.

Expression of cyclooxygenase-2 (E. C. 1.14.99.1) in prostate and the lower urinary tract (LUT) of the neonatally estrogenized male rat has been studied by using a COX-2's PCR fragment of 724 nt spanning 3 introns and a 478nt internal standard for quantitative RT-PCR. The same fragment of 724 nt was used for RNA probe in Northern hybridization. Neonatal estrogenization (10 microg/day of diethylstilbestrol on days 1-5) had no effect on COX-2 expression in prostatic urethra, prostatic lobes, or bladder. Acute estrogen treatment of castrated animals did not induce COX-2 expression, either. In addition the differential expression of basal level of COX-2 in the different lobes of prostate in normal rat was demonstrated. Our results suggest a constant expression of COX-2 gene in prostate and the lower urinary tract of the neonatally estrogenized (neoDES) rats. The present study indicates that the increased expression of COX-2 is probably not essential for the estrogen-driven development of stromal inflammation or hyperplastic and dysplastic alterations in the prostate of neoDES rats.

Animals↗
PubMedDate not supplied

Ultrastructural histochemistry of infantile digital fibromatosis.

A case of infantile digital fibromatosis was studied by light and electron microscopy histochemistry. Using two different acidic solutions of phosphotungstic acid at varying pHs, the round inclusions characteristic of this tumor were shown to have a high protein content with little or no carbohydrates. The histochemical reactivity of the inclusions was similar to that of the cytoplasmic microfibrils in the tumors cells and consistent with the idea that both the inclusions and the microfibrils represent actin. There is, however, no definite proof that the tumor cells are myofibroblasts. At the present time, this tumor should be viewed as a peculiar expression of deranged assembly or metabolism of filamentous proteins or both.

Actins↗