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Biomedical subjects

R Valenzuela

Publications and source records attributed to R Valenzuela.

At least 109 records · Page 6Linked to original sources
PubMed1979

Expression of monocytic--histiocytic cytochemical markers in epithelial neoplasia.

The diagnosis of malignant histiocytosis is usually based upon typical light microscopic features of the neoplasm. Supplementary cytochemical and immunologic features have been suggested as typical of malignant histiocytosis. The present study was prompted by an unusual erythropagocytic hepatocellular carcinoma having immunologic and cytochemical markers suggesting mononuclear phagocytic origin. Twenty-four neoplasms of unquestionable epithelial origin were prospectively evaluated for activity of alpha-naphthyl acetate esterase, a cytochemical marker useful in distinguishing between the non-Hodgkin's lymphomas and malignant histiocytosis. The epithelial tumors represented a broad spectrum of tissue origins and consistently demonstrated alpha-naphthyl acetate esterase activity. Thus, erythrophagocytosis and alpha-naphthyl acetate esterase positivity may be misleading in the unusual instance in which the histopathologic differential diagnosis includes malignant histiocytosis and epithelial neoplasia. Ultrastructural assessment is useful in the exclusion of poorly differentiated carcinoma.

Carboxylic Ester Hydrolases↗
PubMed1979

Gold nephropathy.

Explore the source record for details and available documents.

Glomerulonephritis↗
PubMed1978

Ruptured human renal allograft. Pathogenesis and management.

From January, 1963, to January, 1977, 4 cases of acute allograft rupture occurred in 474 renal transplants performed at the Cleveland Clinic, an incidence of 0.8 per cent. Rupture developed between the fifth and sixteenth day after transplantation during a period when the patients required dialysis because of poor allograft function. All patients had surgical exploration and successful repair of the laceration. Biopsies in each case at the site of laceration revealed findings consistent with acute allograft rejection. The rejections were mild in 2 cases, moderate in one, and severe in another. Two kidneys failed to sustain function, and the patients were returned to chronic hemodialysis two to five months later. None required a nephrectomy. The other two kidneys are functioning well, with serum creatinine values of 1.3 and 1.5 mg./100 ml. one year after allograft rupture. Since rupture of a renal allograft does not appear to increase the intensity of rejection nor does it represent a severe type of rejection, transplant nephrectomy can be avoided unless hemorrhage is uncontrollable from the site of laceration.

Adult↗
PubMed1978

Granular dense deposit disease.

During a retrospective study of dense deposit disease, we observed in three patients, unusual granular electron-dense deposits in the glomerular basement membrane in a laminar pattern. However, the distribution of these electron-dense deposits was similar to the distribution of the homogeneous, extremely electron-dense deposits of dense deposit disease. By light microscopy a membranoproliferative glomerulonephritis was demonstrated in two patients. The other patient had multiple myeloma with glomerulopathy and intratubular protein casts with histiocytic giant cell reaction. By immunofluorescence microscopy the presence of granular deposits in the glomerular basement membrane and mesangium was revealed in only one patient, with anti-human IgM and complement (C3). By electron microscopy was demonstrated the thickening of the glomerular basement membrane by densely packed small granular aggregates of varying sizes, ranging from 100 to 800 A in diameter. Similar electron-dense deposits in a laminar pattern were present in the Bowman's capsule and renal tubular basement membrane of two patients. The specific nature of these small electron-dense deposits is unknown.

Basement Membrane↗
PubMed1977

The renal pathology of Chediak-Higashi disease: usefulness of the urinary sediment as a confirmatory diagnostic test.

The presence of large cytoplasmic inclusions, thought to be abnormal lysosomes, seems to be the cytological hallmark of Chediak-Higashi disease in both humans and animals. This cell anomaly, originally reported in the leukocytes, is also present in various tissue cells, including kidneys. In the patient described, the abnormal inclusions were identified in renal cells of the urinary sediment. Thus, urine could provide a convenient source of diagnostic material in patients with Chediak-Higashi disease. In addition, the ultrastructure of these inclusions is described for the first time in human renal tissue.

Chediak-Higashi Syndrome↗
PubMed1976

Chediak-Higashi syndrome in a black infant. A light and electron microscopic study with special emphasis on erythrophagocytosis.

Clinicopathologic observations in the case of a black infant with Chediak-Higashi syndrome are reported. Light and electron microscopic examination of spleen, liver and lymph nodes revealed abnormal large lysosomes as well as marked erythrophagocytosis without hemosiderosis in infiltrating histiocytes and Kupffer cells. In addition, there were abnormal ocular findings. It is suggested that the erythrophagocytosis without hemosiderosis might also be a specific anatomic expression of this disease due to defective lysosomal digestion of phagocytosed erythrocytes.

Black People↗
PubMedDate not supplied

E-2078, a potent, selective and stable dynorphin analog with preferential activity for the kappa-opioid receptor subtype on the mouse vas deferens neuroeffector junction.

The profile of opioid activity of E-2078, a synthetic stable dynorphin analog, was examined in the mouse vas deferens bioassay and compared to that of methionine enkephalin and nonpeptide kappa agonists in the absence and in the presence of selective antagonists for the mu-, kappa- and delta-opioid receptor subtypes. The inhibitory action of E-2078 and related kappa agonists was specifically and potently antagonized only by norbinaltorphimine, revealing the presence of kappa receptors in this tissue and the predominant kappa activity of E-2078.

Animals↗
PubMedDate not supplied

Serum beta 2-microglobulin and interferon in homosexual males: relationship to clinical findings and serologic status to the human T lymphotropic virus (HTLV-III).

The identification of the human T cell lymphotropic virus (HTLV-III) as the presumed etiologic agent for AIDS has stimulated a re-examination and allowed better understanding of many of the immunologic abnormalities described in high risk individuals with and without clinical disease. Currently needed are useful predictors of clinical progression which will allow better counselling, earlier diagnosis and effective treatment of high risk individuals. We have examined the principles of test selection including sensitivity, specificity, predictive value and overall test efficiency for serum beta 2 microglobulin (beta 2M), serum interferon (IFN) and antibody to HTLV-III (HTLV-III Ab) in a group of 113 homosexual men and 62 controls. The presence of HTLV-III Ab and elevated serum beta 2M appear to be the most sensitive markers of immune dysregulation in the study group but also proved to be the least specific. Rising levels of serum beta 2M correlated with clinical severity where HTLV-III Ab positivity did not. The detection of elevated levels of acid labile serum IFN alpha was most specific for full-blown AIDS and was overall the most efficient test when compared with HTLV-III Ab, serum beta 2M and lymphocyte subpopulations. We believe that further examinations of the principles of test selection for immunologic abnormalities in AIDS may lead to potential applications for these tests in patient management.

Acquired Immunodeficiency Syndrome↗
PubMedDate not supplied

Localization, purification, and biological activity of a new aldosterone-stimulating factor.

An aldosterone-stimulating factor (ASF) has been isolated from normal human urine and found to be a glycoprotein with a molecular weight of 26,000 daltons. ASF stimulated aldosterone production both in vivo and in vitro. ASF was found to be different from other known aldosterone secretogogues by the use of high performance liquid chromatography (HPLC). The retention time of ASF was different (17.0 minutes) from ACTH (retention time, 28.4 minutes), beta-lipotropin (retention time, 20.5 minutes), and angiotensin II. Proteolytic enzyme digestion and purification of ASF by HPLC yielded a smaller molecule (retention time, 22.0 minutes) with a molecular weight of 4000 daltons. This smaller molecule also stimulated aldosterone production in vitro. This showed that the structural requirement for steroidogenesis may be residing in a smaller molecule. ASF failed to produce hypertension in adrenalectomized rats. By immunofluorescence (using fluorescein conjugated antibodies), ASF was found to be localized in the anterior lobe of the pituitary gland. Data suggest that ASF, a new aldosterone-stimulating hormone that has not been described before, is secreted by the pituitary gland, and the adrenal gland appears to be the target organ for the biological activities.

Adrenalectomy↗