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Biomedical subjects

A Suarez

Publications and source records attributed to A Suarez.

At least 55 records · Page 3Linked to original sources
PubMed1993

Correlation of E-cadherin expression with differentiation grade and histological type in breast carcinoma.

Recently, a correlation has been suggested between a loss of E-cadherin (E-CD) and increased invasiveness of neoplastic cells. In this study, E-CD expression in breast cancer was investigated using an affinity-purified antibody (ECCD-2) in an immunoenzymatic (avidin-biotin-alkaline phosphatase) test. Intensity and extension of E-CD immunoreactivity were evaluated in 61 breast carcinomas and correlated with their histological type and grade, nodal involvement, and hormonal receptor status. Histological types were infiltrating ductal carcinoma of no special type (n = 54) and infiltrating lobular carcinoma (n = 7). All infiltrating ductal carcinomas of no special type except two grade 3 carcinomas showed positive immunoreactivity that was variable among different cases. Grade 1 breast carcinomas (n = 10) showed greater immunoreactivity than grade 2 (n = 25) and grade 3 (n = 19) carcinomas. E-CD immunoreactivity correlated positively with the degree of tubular formation and inversely with the mitoses number. None of the infiltrating lobular carcinomas expressed E-CD in their infiltrating cells, whereas they showed only weak immunostains in areas of atypical lobular hyperplasia and lobular carcinoma in situ. These results indicate that E-CD expression correlates with histological type and grade in breast carcinomas.

Breast Neoplasms↗
PubMed1992

Autoimmune insulin syndrome in a patient with progressive systemic sclerosis receiving penicillamine.

The case of a patient with progressive systemic sclerosis, who developed hypoglycaemia and insulin autoantibodies, is described. Repeated blood glucose measurements showed levels less than 2.8 mmol/l. High immunoreactive insulin levels, with undetectable free insulin, led to the discovery of anti-insulin antibodies in the patient's serum. He had no history of exogenous insulin use and was receiving penicillamine treatment. A double mechanism for the autoimmune insulin syndrome in this case is proposed: acting in a patient with increased humoral immunoresponsiveness, penicillamine might have induced the development of insulin autoantibodies.

Adult↗
PubMed1991

Development of a screening method for five sulfonamides in salmon muscle tissue using thin-layer chromatography.

A thin-layer chromatographic (TLC) method was developed for the analysis of five sulfonamides [sulfadiazine (SDZ), sulfamerazine (SMRZ), sulfamethazine (SMTZ), sulfadimethoxine (SDMX) and sulfapyridine (SP)] in salmon muscle tissue. "Matrix solid-phase dispersion" was employed whereby the tissue sample was ground with C18-derivatized silica gel. This material was packed into a column and washed with 10% toluene in hexane (discarded) followed by dichloromethane which was evaporated. The residue was chromatographed on a high-performance TLC plate using ethyl acetate-n-butanol-methanol-aqueous ammonia (35:45:15:2, v/v). Sulfonamides were detected after spraying the plate with a solution of fluorescamine. Method parameters were determined by analyzing spiked salmon muscle tissue samples. The method detection limits at the 99% confidence level were 0.11, 0.44, 0.07, 0.13 and 0.13 ppm for SDZ, SMRZ, SMTZ, SDMX and SP, respectively. The lowest-detectable levels were approximately 0.04 ppm for SDZ, SMTZ, SDMX and SP, and 0.10 ppm for SMRZ. The average recoveries of analyses were 61, 63, 60, 63 and 57% for SDZ, SMRZ, SMTZ, SDMX and SP, respectively, and were found to be analyst-dependent. The method was found to give linear detector responses for all analytes over spiking levels ranging from 0 to 2 ppm.

Animals↗
PubMed1991

Cognitive-behavioral treatment of chronically parasuicidal borderline patients.

A randomized clinical trial was conducted to evaluate the effectiveness of a cognitive-behavioral therapy, ie, dialectical behavior therapy, for the treatment of chronically parasuicidal women who met criteria for borderline personality disorder. The treatment lasted 1 year, with assessment every 4 months. The control condition was "treatment as usual" in the community. At most assessment points and during the entire year, the subjects who received dialectical behavior therapy had fewer incidences of parasuicide and less medically severe parasuicides, were more likely to stay in individual therapy, and had fewer inpatient psychiatric days. There were no between-group differences on measures of depression, hopelessness, suicide ideation, or reasons for living although scores on all four measures decreased throughout the year.

Adolescent↗
PubMed1991

Treatment of stage IV-S neuroblastoma: a study of 34 cases treated between 1982 and 1987.

Between January 1982 and December 1987, of 283 children with neuroblastoma treated in the Pediatric Department of Institut Gustave Roussy, 34 were stage IV-S. Two groups were distinguished according to the initial clinical presentation: 16/34 patients had life-threatening symptoms and needed immediate treatment, and 18/34 had no life-threatening symptoms. Hepatic irradiation was used in 12/16 patients of the first group with respiratory distress. Chemotherapy was used in three patients. Of these 16 patients, three patients died of progressive disease (one patient died of a reason not related to the tumor). Twelve are alive in first complete remission and one in second complete remission. Of the 18 patients of the second group, eight had spontaneous complete remission, and one of them relapsed thereafter and died despite treatment. Ten patients needed treatment, radiotherapy, and/or chemotherapy depending on the site of disease progression. Two of them died of the disease. The overall disease-free survival for these 34 patients is 75% at 90 months postdiagnosis. Using this therapeutic strategy, it was possible to avoid any treatment of metastases in 25% of the patients.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1991

Long-term follow-up of ifosfamide renal toxicity in children treated for malignant mesenchymal tumors: an International Society of Pediatric Oncology report.

The renal function of 74 children with malignant mesenchymal tumors in complete remission and who have received the same ifosfamide chemotherapy protocol (International Society of Pediatric Oncology Malignant Mesenchymal Tumor Study 84 [SIOP MMT 84]) were studied 1 year after the completion of treatment. Total cumulative doses were 36 or 60 g/m2 of ifosfamide (six or 10 cycles of ifosfamide, vincristine, and dactinomycin [IVA]). None of them had received cisplatin chemotherapy. Ages ranged from 4 months to 17 years; 58 patients were males and 42 females. The most common primary tumor site was the head and neck. Renal function was investigated by measuring plasma and urinary electrolytes, glucosuria, proteinuria, aminoaciduria, urinary pH, osmolarity, creatinine clearance, phosphate tubular reabsorption, beta 2 microglobulinuria, and lysozymuria. Fifty-eight patients (78%) had normal renal tests, whereas 16 patients (22%) had renal abnormalities. Two subsets of patients were identified from this latter group: the first included four patients (5% of the total population) who developed major toxicity resulting in Fanconi's syndrome (TDFS); and the second group included five patients with elevated beta 2 microglobulinuria and low phosphate reabsorption. The remaining seven patients had isolated beta 2 microglobulinuria. Severe toxicity was correlated with the higher cumulative dose of 60 g/m2 of ifosfamide, a younger age (less than 2 1/2 years old), and a predominance of vesicoprostatic tumor involvement. This low percentage (5%) of TDFS must be evaluated with respect to the efficacy of ifosfamide in the treatment of mesenchymal tumors in children.

Acute Kidney Injury↗
PubMed1990

Hydatidiform moles and teratomas confirm the human identity of the preimplantation embryo.

Results of recent research on hydatidiform moles and teratomas show that during pregnancy the embryo does not receive any message or information from the mother able to control the mechanisms of development or to produce the type of cellular differentiation necessary for building the tissues of the new human adult. Thus, the biological identity of the new human being does not depend on the sojourn in the uterus; the preimplantation embryo is the same individual of the human species as the adult, into whom the embryo can in principle develop.

Beginning of Human Life↗
PubMed1990

Amniotic fluid catecholamine metabolites in maternal smoking.

The concentration of dopamine (DA), norepinephrine (NE), and its metabolites 3-methoxy-4-hydroxy-phenylethylene glycol (MHPG) and vanillyl mandelic acid (VMA), and prostaglandins E2, and F2a in amniotic fluid were measured at labor (1-3 cm of cervical dilatation), in uncomplicated and complicated pregnancies. The amniotic fluid concentration (mean +/- SD) of MHPG in maternal smoking (S) (30.6 +/- 11.9 nmol.mg creatinine-1) and intrauterine growth retardation (IUGR) (36.7 +/- 15.2 nmol.mg creatinine-1) groups is significantly higher than in uncomplicated pregnancies (C) (22.9 +/- 8.8 nmol.mg creatinine-1), or diabetes mellitus groups (D) (26.1 +/- 10.9 nmol.mg creatinine-1) groups; VMA presents similar differences between groups S (145.8 +/- 84.4 nmol.mg creatinine-1) and IUGR (173.0 +/- 135.4 nmol.mg creatinine-1) higher than C (58.3 +/- 26.1 nmol.mg creatinine-1) and D (76.8 +/- 49.0 nmol.mg creatinine-1) groups. NE levels differ between groups in a similar way, but DA does not present significant differences between groups. Prostaglandin levels are higher in the S than in the C group. Nicotine action and/or hypoxia are proposed as a possible cause of NE, MHPG, and VMA rise in amniotic fluid of S, and IUGR versus C or D groups.

Amniotic Fluid↗
PubMed1990

RETROCELL HIV-1 passive hemagglutination assay for HIV-1 antibody screening.

A passive hemagglutination assay (PHA) for serum human immunodeficiency virus type 1 (HIV-1) antibody screening was developed using aldehyde-stabilized human erythrocytes coated with purified HIV-1 antigens. The assay is simple to perform, and the components are inexpensive. In preliminary testing of a panel of 490 confirmed HIV-1 seropositive specimens, all tested positive by the HIV-1 PHA assay. By testing seroconversion specimens and dilution panels, the assay demonstrated a sensitivity equivalent to a recombinant protein-based HIV-1 enzyme immunoassay (EIA). In-house evaluation of 2,557 HIV-1 prescreened specimens from South African blood bank donors revealed initial and repeat reactive rates of 0.2 and 0.04%, respectively. Field testing of the HIV-1 antibody PHA at two sites gave performance of 100% sensitivity (400 seroconfirmed samples) and 0.55% initial/0.28% repeat reactive rates in the testing of 3,983 negative samples. The performance, low cost, and ease of use make the HIV-1 antibody PHA test a prime candidate for HIV-1 antibody screening in regions of the world where more sophisticated technology is inappropriate.

Blotting, Western↗
PubMed1989

Agonist binding to M1 muscarinic receptors is sensitive to guanine nucleotides.

Putative M1 (high-affinity pirenzepine) muscarinic receptors in rabbit hippocampal membranes, treated with 0.1 mM N-ethylmaleimide (NEM), were selectively labeled with [3H]pirenzepine. A single class of binding sites was labeled with a Kd of 3.4 nM, consistent with the pharmacologically-defined M1 subtype of muscarinic receptors. While full muscarinic agonists bound to high- and low-affinity states of [3H]pirenzepine-labeled M1 sites with a KL/KH ratio of approximately 100, the ratio for partial muscarinic agonists was approximately 10. The high-affinity binding of all agonists tested required divalent cations, and was interconverted to low-affinity binding in the presence of the non-hydrolyzable GTP analogue, guanylyl imidodiphosphate (GppNHp). Direct labeling of the high-affinity agonist state of M1 receptors was achieved with 5 nM [3H]oxotremorine-M by selectively uncoupling the high-affinity agonist state of M2 (low-affinity pirenzepine) receptors with NEM. The rate of dissociation of [3H]Pxotremorine-M from M1 receptors was accelerated 6-fold by GppNHp. These results provide further evidence which suggests that putative M1 muscarinic receptors activate second messenger systems by coupling to NEM-insensitive guanine nucleotide-binding proteins.

Animals↗
PubMed1989

Increased synthesis and production of prostaglandin E2 by monocytes from drug addicts with AIDS.

We analysed the production of prostaglandin E2 (PGE2) by monocytes in 11 drug addicts with AIDS and opportunistic infections and in 13 controls. In three patients and six controls we isolated the PGE2 fraction from culture supernatants of purified monocytes (greater than 95%) incubated in medium containing (3H) arachidonic acid, using silicic acid columns. In two of three patients PGE2-fraction values (21.9 and 21.6 pmol/g protein) were significantly higher than controls (10 +/- 4). In eight AIDS patients and seven controls, PGE2 levels were determined by high-performance liquid chromatography and radioimmunoassay (HPLC and RIA). In three out of eight patients PGE2 levels were markedly higher (736, 419 and 208 pg/ml) than the mean + 2 s.d. values from controls (73 +/- 51). We tested the effect of PGE2 on the production of interleukin-2 by normal phytohemagglutinin-stimulated peripheral blood lymphocytes (PBL). There was a significant suppression of interleukin-2 production by PGE2 released from AIDS monocytes. PGE2 may be one of the factors involved in the severe immune dysfunction associated with AIDS.

Acquired Immunodeficiency Syndrome↗
PubMed1989

Clindamycin and tetracycline as immunomodulating agents: an in vivo study.

The present study was undertaken to determine the effects of clindamycin and tetracycline, both intravenously administered, on antibody response to thymus-dependent antigen (PC-KLH) in BALB/c mice. The immunological parameters evaluated were: DPFC/spleen (direct plaque forming-cells), antibody secretion median rate (PC50), heterogeneity index (Hi), number of total splenic lymphocytes and cellular viability. The results showed that clindamycin (i.v.) increased the humoral response; 28 mg/kg was the dose that showed the greatest enhancement (+73%). The PC50 was not affected by clindamycin but Hi decreased at 28 mg/kg and increased at 2.8 mg/kg doses, although neither result was statistically significant. When tetracycline was given i.v., a slight decrease in the anti-PC DPFC number was observed. Although the PC50 was greater at 10 mg/kg (p less than 0.05), Hi was smaller at the 1 mg/kg dose (p less than 0.05).

Adjuvants, Immunologic↗
PubMed1989

Comparative effects of three beta-lactam antibiotics on anti-PC direct plaque-forming cells.

Penicillin G, cefotaxime and clavulanic acid administered intravenously were studied for their immunomodulating properties. BALBC/c mice were immunized using PC-KLH as thymus-dependent antigen at the same time as the antibiotic was injected. The effect on antibody response was evaluated 5 days after immunization. Critical immunological parameters such as direct antibody-producing cells, Ab-secretion median rate, secretion rate heterogeneity and cellular viability, were studied. The most stimulatory effects were with penicillin G at the 4 x 10(6) IU/kg dose (+73%), cefotaxime at the 366 mg/kg dose (+80%) and clavulanic acid at 1 mg/kg (+218%). The experiments using inhibition of plaque formation with free hapten demonstrate that all the drugs studied decreased the antibody secretion rate and this parameter appeared more heterogeneous when cefotaxime and clavulanic acid were given; however, with penicillin this parameter was more heterogeneous at 2 x 10(5) mg/kg and 1 x 10(3) IU/kg respectively. When clavulanic acid was injected, the number of lymphocytes per spleen, size and friability of the spleen were increased versus the control mice. The present data show that all of the drugs studied present immunostimulating effects on humoral response, against thymus-dependent antigen, but have differently pronounced enhancements.

Animals↗
PubMed1988

Somatostatin in the management of gastrointestinal hemorrhage: bleeding ulcers.

Stress ulcers are characterized by difficult management and poor prognosis. They currently represent a complication in the clinical course of other conditions, mainly shock states. The pathogenesis of stress ulcers is not well understood although the role of hypovolemia leading to energetic deprivation and insaturation of anaerobic cellular metabolism have been carefully studied. Somatostatin has been found to reduce the incidence of experimental stress ulcers. In the clinic, patients with duodenal ulcers were found to exhibit a low number of antral D cells and a significant decrease in tissue somatostatin. In a multicenter trial, patients with bleeding peptic or stress ulcers were treated with somatostatin or cimetidine plus pirenzepine. Results were favorable to the former substance on account of the time required to stop the hemorrhage and the demands for blood replacement. Thus, medical management of bleeding ulcers with somatostatin may represent an alternative to more radical surgical intervention.

Animals↗
PubMed1987

Gastric mucosal somatostatin-like immunoreactivity in peptic ulcer.

Somatostatin (SS) has been reported to exert potent inhibitory effects on gastric acid, pepsin and gastrin secretion. Although still controversial, the results of several studies have shown a possible influence of a local decrease in gastric somatostatin in the physiopathologic characteristics of peptic ulcer disease. In the present study, immunoreactive SS content (SLI) of antral (SLI-a), corpal (SLI-c) and fundic (SLI-f) mucosal extracts was measured by radioimmunoassay (RIA) in control patients (C) and in those patients with duodenal ulcer (DU) or gastric ulcer (GU) to further study a possible role of SS in peptic ulcer disease. Fifty-five patients (C = 20, DU = 21 and GU = 14) were included in the study. Gastric mucosal samples were obtained either by endoscopic biopsy (4.6 +/- 0.2 milligrams of weight) or operation (52.3 +/- 3.8 milligrams of weight). RIA was performed after a modified Arimura's method and results were expressed as nanograms per milligram of tissue plus or minus standard error of the mean. Chromatographic analysis of gastric mucosal extracts was performed on a Sephadex G-25 fine column. A great interindividual variation in SLI levels was observed (a range of 0.02 to 5.30 nanograms per milligram of weight). The mean SLI concentrations were: C (SLI-a, 2.55 +/- 0.45, SLI-c, 0.99 +/- 0.46 and SLI-f, 1.03 +/- 0.21); DU (SLI-a, 0.48 +/- 0.16, SLI-c, 0.43 +/- 0.13, and SLI-f, 0.58 +/- 0.12), and GU (SLI-a, 1.10 +/- 0.25, SLI-c, 0.40 +/- 0.10, and SLI-f, 0.81 +/- 0.24). Significantly greater amounts of SLI contents were found in the antrum of control patients as compared with those found in the corpus or fundus (p less than 0.05 and p less than 0.01, respectively). SLI-a levels were lower in peptic ulcer patients (DU, p less than 0.001 and GU, p less than 0.05) than in control patients. There was also a significant difference between SLI-a levels in DU versus GU patients (p less than 0.05). No significant differences were found in SLI-c and SLI-f contents in all three groups studied. In conclusion, these results suggest that decreased SS levels in antral gastric mucosa could be the alteration underlying the various physiopathologic mechanisms involved in the development of peptic ulcer disease.

Adult↗
PubMed1986

Antral gastrin-producing G-cells and somatostatin-producing D-cells in peptic ulcer.

The number of G cells and D cells per area unit and the G cell/D cell ratio was studied in control subjects and patients with duodenal or gastric ulcer. A great inter-individual variation in the population density of both types of cells was observed in the three groups studied. G cell density was significantly decreased in both duodenal and gastric ulcer patients, when compared with controls; whereas no difference in G cell density was seen between duodenal ulcer patients and gastric ulcer patients. However, D cell density was significantly decreased in duodenal ulcer patients when compared with control subjects and gastric ulcer patients. In this latter group, D cell density was also lower than in control subjects. A significant positive linear correlation between G cell number and D cell number was found in the three groups studied. The G cell/D cell ratio was significantly increased in duodenal and gastric ulcer patients when compared with controls. This was mainly due to a decrease in D cell numbers. It is concluded that a local deficit in antral D cells in patients with peptic ulcer may favor the pathogenesis of ulcer disease.

Adult↗
PubMed1986

Female urinary incontinence: preoperative selection, surgical complications and results.

A total of 98 women with stress urinary incontinence underwent surgical repair via 3 different techniques: 38 patients underwent a Burch colposuspension (group 1), 25 underwent a Stamey procedure (group 2) and 35 had a modified Pereyra operation (group 3). The main indication for an operation was clinically unacceptable incontinence, and urodynamic studies were done on all patients with associated stress and urge incontinence or who underwent reoperation. Subtracted bladder pressure recording was an important preoperative screening tool, since patients with high pressure instability did worse surgically than those with a stable bladder or low pressure instability. In patients with detrusor stability similar results were achieved for initial surgery and reoperations. Among the patients with a stable bladder with and without a previous anti-incontinence operation the over-all results were better in groups 1 and 3 than in group 2. Complications were of lesser magnitude in groups 2 and 3 than in group 1.

Adult↗