Search PubMed⌕ Search

Biomedical subjects

J Guevara

Publications and source records attributed to J Guevara.

At least 55 records · Page 3Linked to original sources
PubMed1988

Intrasellar cysticercosis.

Eight patients with cysticerci located inside the sella turcica are presented, and the clinical and radiological features of this rare form of neurocysticercosis are discussed. Clinical features included nonspecific ophthalmological and endocrinological disturbances similar to those produced by other sellar lesions. Computerized tomography (CT) usually showed a hypodense mass that simulated either a cystic tumor or an arachnoid cyst. Cerebrospinal fluid (CSF) findings were also nonspecific, as immunological reactions to cysticercosis were most often negative when inflammation was limited to suprasellar and intrasellar regions. An incorrect diagnosis of tumor was frequent in these cases. In contrast, when intrasellar cysticercosis was associated with other forms of neurocysticercosis, proper integration of CT and CSF data permitted an accurate diagnosis. Cysticercosis should be suspected in patients with hypodense juxtasellar lesions living in geographical areas where this disease is endemic. Prompt surgical resection of cysticerci will avoid irreversible damage to visual function.

Adult↗
PubMed1986

Distinctive protein pattern in two-dimensional electrophoretograms of cancerous prostatic tissues.

In this report, we describe methods used to analyze the protein composition of sectioned frozen prostatic tissues by two-dimensional gel electrophoresis. Our results show a high degree of homology in two-dimensional electrophoretograms of proteins extracted from frozen sections of malignant prostate glands. Such homology was not apparent in protein patterns of benign hypertrophic prostatic tissue sections. Typically, 600 discrete proteins were resolved on two-dimensional electrophoretograms and 9 proteins were present in all patterns of prostate adenocarcinomatous tissues. These nine proteins were not observed in any of the protein electrophoretograms developed from nonmalignant prostate tissue. Three proteins were found common to nonmalignant prostate glands but were not present in prostatic adenocarcinoma.

Aged↗
PubMed1985

Plasma proteins as indices of response to nutritional therapy in cancer patients.

The use of plasma albumin (ALB), transferrin (TFN), prealbumin (TBPA), retinol-binding protein (RBP), triceps skin fold (TSF), and midarm muscle circumference (MAMC) as determinants of response to nutritional therapy (TPN) was investigated in 40 cancer patients during preoperative TPN. Thirty-one patients received 90% or more of their anabolic caloric requirement (Harris-Benedict equation) by means of TPN. During this study period (average 11.1 +/- 4.7 days) nutritional assessments were completed before TPN and on the last day of TPN before surgery. Average weight loss based on usual body wt (UBW) and ideal body wt (IBW) was 19 +/- 11% and 9 +/- 15%, respectively (not significant, NS). Weight loss (UBW) correlated with ALB (P less than 0.001), TBPA (P less than 0.005) and RBP (P less than 0.02) but did not correlate with TFN (P less than 0.06), TSF, and MAMC. Weight loss (IBW) correlated with TSF (P less than 0.01) and MAMC (P less than 0.03) but did not correlate with plasma protein (PP). During TPN the average percent increases for PP were 0.1% (ALB, NS), 20% (TFN, NS), 60% (TBPA, P less than 0.02), and 116% (RBP, P less than 0.005). These results suggest that plasma TBPA and RBP are significant parameters of response to short-term nutritional therapy in cancer patients.

Adult↗
PubMed1985

Two-dimensional electrophoretic analysis of human prostatic fluid proteins.

The heterogeneous mixture of proteins present in expressed prostatic fluid from forty-nine men over 25 years old was analyzed on two-dimensional electrophoretic gels stained with silver. Samples were collected from men diagnosed with chronic prostatitis, urinary tract infection, benign prostatic hypertrophy (BPH), and prostatic carcinoma. Reference patterns were developed for all proteins observed in electrophoretograms. Over 1000 distinct proteins are contained in the comprehensive proteins pattern of prostatic fluid; however, only 18 proteins were common to all samples. No proteins unique to fluids from men with BPH or prostatic cancer were observed. Some proteins in the common proteins reference pattern of BPH patients were not seen in samples from men with prostatic cancer. Our preliminary results indicate that a series of proteins tentatively identified as variants of prostatic acid phosphatase appeared elevated in all BPH fluids but was absent or below limits of detection in samples from men with prostatic carcinoma. Our studies indicate that proteins secreted in prostatic fluid reflect physiological changes in the prostate, and certain changes may be useful indicators of malignant transformation.

Adult↗
PubMed1984

Induction of proteins in human lymphoblastoid cells by recombinant alpha interferon.

Two-dimensional gel electrophoresis, using either silver staining or pulse labeling with 35S-L-methionine and autoradiography, was employed to determine changes in the synthesis of proteins that may be involved in the antiproliferative effects of recombinant alpha interferon (IFNrA) on Burkitt's lymphoma Daudi cells. IFNrA initiated and/or augmented the synthesis of at least 13 proteins that were distinct in molecular weights and isoelectric properties. Synthesis of several of these IFN-enhanced proteins was inhibited by actinomycin-D, an inhibitor of mRNA synthesis. Although IFN-induced antiproliferative effects were observed at 48 h, an increase in the synthesis of several proteins was observed as early as 3 h. The levels of these IFN-enhanced proteins in treated cells continued to increase through 24 h. At least two proteins of approximately 17 kD were observed to be synthesized in IFN-treated cells but not in control cells. Neither inhibition of synthesis of any particular protein nor post-synthetic modification of proteins in response to IFNrA was observed with these methods. The results of this study are compared and contrasted to those of several other laboratories.

Burkitt Lymphoma↗
PubMed1982

Isolation, purification, and partial characterization of type V-A hemagglutinin from Escherichia coli GV-12, O1:H-.

A hemagglutinin which specifically agglutinates human type A erythrocytes (mannose resistant) was isolated from the growth medium of cultures of Escherichia coli GV-12, serotype O1:H-, and purified by chromatography on Bio-Gel A-1.5 and DEAE-Sephadex A-25. The purity of the hemagglutinin was established by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and immunoelectrophoresis. N-terminus analysis indicated that only asparagine resides on the amino terminus. The native hemagglutinin is an aggregate exhibiting a sedimentation coefficient of 9.25, which corresponds to a molecular weight of approximately 200,000. The monomeric molecular weight was found to be approximately 16,300. Amino acid analysis indicated that the hemagglutinin consists of 131 residues, corresponding to a molecular weight of 13,400.

Amino Acids↗
PubMed1982

Proteins of human urine. II. Identification by two-dimensional electrophoresis of a new candidate marker for prostatic cancer.

A protein series common to the urine and prostatic tissue of 16 of 17 patients with prostatic adenocarcinoma has been identified by high-resolution two-dimensional gel electrophoresis. These proteins, designated PCA-1, have a relative molecular mass in sodium dodecyl sulfate of about 40000. Analyses of urines from eight age-matched controls, seven patients with other ty pes of urogenital malignancies, two patients with benign prostatic hyperplasia, and five patients with malignancies not associated with the urogenital system failed to show PCA-1 in the patterns. These preliminary findings suggest that this protein should be systematically investigated as a candidate marker for prostatic adenocarcinoma in man.

Adenocarcinoma↗
PubMed1982

A simple method of eluting proteins from two-dimensional gels.

Apo A-I lipoprotein was extracted from the appropriate pieces of two-dimensional gel patterns, by electrophoresis onto hydroxylapatite overlaying a slab of polyacrylamide sodium dodecyl sulfate gel. The extracted protein was then eluted from the hydroxylapatite by washing with increasing concentrations of phosphate buffer. The recovered protein was electrophoretically homogeneous. We believe that this method can be generally useful in the purification, for study, of proteins identified on two-dimensional gels as putative markers of disease.

Apolipoproteins↗
PubMed1978

Effect of propranolol on sympathetic nervous activity in hydrallazine-treated hypertensive patients.

1 The effect of propranolol was examined on a) blood pressure and heart rate responses due to i.v. hydrallazine b) modification of these cardiovascular parameters during cold pressor test c) urinary catecholamine excretion rate. 2 Intravenous hydrallazine reduced significantly mean blood pressure by 15.2 mm Hg and increased heart rate by 24.9 beats/min. Propranolol reduced significantly mean blood pressure by 19.0 mm Hg and heart rate by 14.1 beats/min. Hydrallazine plus propranolol caused a significant reduction of mean blood pressure (by 37.7 mm Hg) but this was not accompanied by a significant fall in heart rate (by 3.3 beats/min). 3 During the control period, cold pressor test increased mean blood pressure by 16.0 mm Hg. Heart rate was increased by 12.5 beats/min in four patients. However, there was a reduction in heart rate (5.5 beats/min) in two other patients. During the propranolol period, cold pressor test-induced increase of mean blood pressure was not reduced but propranolol blocked the increase of heart rate. 4 Urinary catecholamine excretion rate was increased during hydrallazine administration. This excretion was not modified by propranolol.

Adult↗
PubMed1976

A sliding intravenous dose schedule for clonidine in hypertensive patients.

Cumulative doses of clonidine were administered intravenously to 8 hypertensive patients to a maximal dose of 100 mug or a blood pressure fall to normal. There was a reduction in mean arterial pressure of 35.6 mm Hg (p less than 0.001), accompanied by a decrease in heart rate of 11.8 bpm (p less than 0.001). There was also a significant linear relationship between the reduction in blood pressure and the intravenous log dose of clonidine with 6.5-fold difference in delta MAP/dose potency. There was no correlation between the baseline blood pressure and the slopes of dose-blood pressure response curves or the reduction in mean arterial pressure; the rate of the decline of the hypotensive effect of clonidine varied widely between patients and was not related to baseline blood pressure.

Adult↗