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Biomedical subjects

E Levine

Publications and source records attributed to E Levine.

At least 73 records · Page 4Linked to original sources
PubMed1993

Left ventricular outflow tract obstruction following repair of pneumococcal mitral annular abscess.

An unusual case of a mitral annular abscess caused by Streptococcus pneumoniae was diagnosed by transesophageal echocardiography. The patient underwent surgical resection of the abscess and developed outflow tract obstruction. This is an unusual complication of the surgical procedure. The outflow tract obstruction may have been due to anterior displacement of the mitral valve by the abscess.

Abscess↗
PubMed1992

Past pregnancy is associated with axillary node involvement in women with breast cancer.

In 186 women with breast cancer, there was a progressive increase in the proportion of axillary nodal involvement as the number of pregnancies increased from zero to two or more (P = 0.026). Logistic regression analysis demonstrated that this effect was independent of the known relationship of age and tumor size to nodal involvement. Race and history of breast feeding had no influence on nodal involvement.

Axilla↗
PubMed1992

Renal cell carcinoma in uremic acquired renal cystic disease: incidence, detection, and management.

Patients with end-stage kidney disease, particularly those treated with dialysis, have an increased risk of renal cell carcinoma. Renal cell carcinoma may also develop in the native kidneys of renal transplant recipients with good graft function many years after transplantation. Recent studies suggest that the incidence of renal carcinoma among dialysis patients is 3-6 times greater than in the general population. However, annual imaging of the native kidneys of all dialysis patients is not justified because it has not been shown to have a significant effect on patient outcome. Screening may, however, be useful in selected patients with good general medical conditions and who have known risk factors for renal carcinoma.

Carcinoma, Renal Cell↗
PubMed1992

Lymphangioma presenting as a small renal mass during childhood.

Renal lymphangioma is a very rare lesion. A case of lymphangioma that presented as a small, hyperechoic renal mass on sonography in a child is reported. On CT, the lesion appeared as a low-density, enhancing renal mass. Despite its rarity, lymphangioma should be considered in the differential diagnosis of such a lesion. A suspected lymphangioma may be evaluated by percutaneous biopsy.

Acute Disease↗
PubMed1992

Familial pheochromocytomas with unusual associations.

Pheochromocytoma occurs in a familial pattern in approximately 10% of patients. Although most familial pheochromocytomas are an expression of the genetic abnormality of neuroectodermal dysplasia or the genetic syndrome of multiple endocrine neoplasia, some familial pheochromocytomas occur without associated disease. Two patients with familial pheochromocytoma are described. One had an extraadrenal tumor, producing severe renal artery stenosis and in whose family pheochromocytomas were found in three successive generations. A second had multiple pheochromocytomas associated with von Hippel-Lindau disease and a family member with multiple endocrine neoplasia type 2. The combinations and permutations of these genetic entities form discrete syndromes, with other peculiar interrelationships, pathologically related to an aberration in the migration, growth, and differentiation of the neural crest cells, and emphasizing their common neuroectodermal origin. The unique features that characterize the familial pheochromocytomas and cause diagnostic and therapeutic challenges are reviewed.

Adrenal Gland Neoplasms↗
PubMed1992

Renal infarction associated with an extraadrenal pheochromocytoma.

A patient with an abdominal extraadrenal pheochromocytoma showed computed tomography findings of renal infarction. Selective angiography of the affected kidney showed no evidence of arterial occlusion or emboli. We postulate that the renal infarcts were caused by reversible severe vasospasm associated with high systemic blood levels of norepinephrine and angiotensin II.

Angiography↗
PubMed1992

Mutational analysis of gap junction formation.

The paired oocyte cell-cell channel assay was used to investigate the mechanisms involved in the process of formation of gap junction channels. Single oocytes, injected with connexin-specific mRNAs, accumulate a pool of precursors from which cell-cell channels can form rapidly upon pairing. Several lines of evidence, including immunohistochemistry and surface labeling, indicate that part of this precursor pool is located in the cell membrane, probably in the form of closed hemichannels. The homophilic binding of hemichannels to each other can be mimicked by synthetic peptides representing the extracellular loop sequences of connexin32. The peptides specifically suppress channel formation. A crucial role is established for the six cysteines in the extracellular domains that are conserved in all vertebrate gap junction proteins. Change of any of these cysteines into serines results in absolute loss of function of the mutant connexin. The effects of thiol-specific reagents on channel formation suggest that docking and/or opening of channels involves disulfide exchange. Several of the variable amino acids in the extracellular loop sequences were found to determine specificity of connexin-connexin interactions.

Amino Acid Sequence↗
PubMed1992

Calcified renal stones and cyst calcifications in autosomal dominant polycystic kidney disease: clinical and CT study in 84 patients.

Although renal calculi and cyst calcifications occur commonly in patients with autosomal dominant polycystic kidney disease (ADPKD), their true frequency is unknown because it is difficult to distinguish between the two with excretory urography and sonography. A detailed analysis of renal calcifications in ADPKD based on CT findings has not been performed. Accordingly, we retrospectively evaluated clinical and CT findings in 84 patients with ADPKD to determine the frequency of calculi and cyst calcifications, the relationship of these abnormalities to symptoms, and possible factors in their pathogenesis. Of the 84 patients, 53 had both IV contrast-enhanced and unenhanced CT scans and 31 had unenhanced scans only. We examined unenhanced CT scans of all 84 patients for renal calcifications. However, we classified renal calcifications into stones and cyst calcifications in only the 53 patients, because it is often difficult to distinguish between the two when only unenhanced scans are available. Of 84 patients, 18 (21%) had passed renal calculi or had stones treated surgically and 42 (50%) had renal calcifications on CT. Of the 53 patients who had both enhanced and unenhanced CT scans, 19 (36%) had renal calculi on CT. Patients with stones had significantly higher frequencies of previous flank pain (68% vs 35%) and of urinary tract infections (63% vs 18%) than did those without calculi. Cyst calcifications occurred in 13 (25%) of 53 patients and were probably a consequence of cyst hemorrhage. Cyst calcifications were found significantly more often in older patients with larger kidneys and worse renal function. We conclude that renal stones have a high rate of occurrence among patients with ADPKD and are a significant cause of morbidity in this disorder. Cyst calcification is also common in patients with ADPKD, particularly those with more advanced cystic disease.

Adolescent↗
PubMed1992

Diminished ratio of estrogen receptors to progesterone receptors in breast carcinomas of women who have had multiple miscarriages.

We examined the relationship of a history of miscarriage to the ratio of tumor estrogen receptors to progesterone receptors in 74 women with breast carcinoma evaluated between 1988 and 1990. Only women who had been pregnant and whose tumor contained both estrogen and progesterone receptors were included. Women with breast carcinoma and a history of two to four miscarriages had significantly lower ratios (less than 1) of tumor estrogen receptors to progesterone receptors than women with a history of zero or one miscarriage (greater than 1). This finding may be the result of a genetic anomaly in breast cancer patients that also affects the uterine environment during the reproductive years.

Abortion, Habitual↗
PubMed1991

Cell/cell channel formation involves disulfide exchange.

The oocyte cell/cell-channel assay was used to identify amino acids involved in the process of cell/cell-channel formation. The expression of the rat liver gap-junction protein, connexin 32, in single oocytes, results in the accumulation of a pool of channel precursors. Upon pairing of such oocytes, cell/cell channels form rapidly from this pool. The rate of formation is affected by thiol-specific reagents and the pH. This suggests the involvement of extracellular cysteine residues in the channel formation process. Two connexin-32 mutants were generated by site-directed mutagenesis in which cysteine residues were replaced by serine. Both mutant connexins were unable to form cell/cell channels. Thus, the cysteine residues appear to play an important role in the channel formation process.

Animals↗
PubMed1991

Gating properties of connexin32 cell-cell channels and their mutants expressed in Xenopus oocytes.

Carboxyl-terminal deletion mutants of the gap junction protein connexin32 were tested in the oocyte cell-cell channel assay. Oocytes expressing a mutant lacking 58 carboxyl terminal amino acids were found to exhibit junctional conductances of the same magnitude as oocytes expressing wild-type connexin32. The gating properties of the channels formed by this mutant of connexin32 with respect to transjunctional voltage and cytoplasmic acidification are indistinguishable from those found with wild-type connexin32 channels. This includes a novel pH-dependent voltage gate. In another mutant, two carboxyl terminal serine residues, Ser233 and Ser240, were replaced by Asn residues. This double mutant has properties indistinguishable from wild-type connexin32, suggesting that phosphorylation of either of these serines is not required for channel opening.

Animals↗
PubMed1991

CT evaluation of active adrenal histoplasmosis.

We describe three patients with puzzling systemic illnesses in whom computed tomography (CT) led to the diagnosis of active adrenal histoplasmosis. CT was performed in two patients because of gastrointestinal symptoms and weight loss and in the third because of fever developing 2 years after an apparent cure of histoplasmosis. All three patients had adrenal enlargement on CT with features of granulomatous adrenal disease in two. Hormone assays performed after CT supported the diagnosis of adrenal insufficiency and fine-needle adrenal aspiration biopsy with special stains of the aspirates showed histoplasma organisms in all three patients. The combination of adrenal enlargement on CT and laboratory findings of adrenal insufficiency should suggest the diagnosis of histoplasmosis, especially in endemic areas.

Adrenal Gland Diseases↗
PubMed1991

Chocolate craving and liking.

Liking and craving for chocolate and related substances were surveyed in a sample of University of Pennsylvania undergraduates (n = 249) and their parents (n = 319). Chocolate was highly liked in all groups, with a stronger liking by females. Chocolate is the most craved food among females, and is craved by almost half of the female sample (in both age groups). Although this craving is related to a sweet craving, it cannot be accounted for as a craving for sweets. About half of the female cravers show a very well defined craving peak for chocolate in the perimenstrual period, beginning from a few days before the onset of menses and extending into the first few days of menses. There is not a significant relation in chocolate craving or liking between parents and their children. The current motivation for chocolate preference seems to be primarily, if not entirely, sensory. Liking for chocolate correlates significantly with liking for sweets and white chocolate. The liking for the sensory properties could originate in innate or acquired liking based on the sweetness, texture and aroma of chocolate, or it could be based in part on interactions between the postingestional effects of chocolate and a person's state (e.g., mood, hormone levels). Based on correlational data, we find little evidence for a relation between addiction to chocolate or the pharmacological (e.g., xanthine-based) effects of chocolate and the liking for chocolate.

Adolescent↗
PubMed1991

Extracellular matrix gene expression by human endothelial and smooth muscle cells.

In this study, the expression of extracellular matrix genes by vascular cells from human iliac blood vessels was characterized on the mRNA steady-state level by slot blot and Northern transfer analyses, as well as by in situ hybridization. Endothelial cells were isolated from adult human iliac arteries and veins, as well as from umbilical veins; smooth muscle cells were isolated from adult human iliac arteries and inferior vena cava. The results show that confluent umbilical vein endothelial cells expressed the genes that encode types I, III, IV and VI collagens, as well as fibronectin and laminin. In contrast, the iliac endothelial cells expressed the genes for types IV and V collagens, fibronectin and laminin; mRNA transcripts for types I, III and VI collagens were not detectable. The smooth muscle cells from iliac arteries or inferior vena cava displayed gene expression for types I, III, IV, V and VI collagens, fibronectin and laminin. The results indicate major differences in gene expression for the various types of collagens by human iliac endothelial and smooth muscle cells. Furthermore, the fetal-derived umbilical endothelial cells displayed differential collagen gene expression from that of adult iliac endothelial cells.

Adolescent↗