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Biomedical subjects

C Miranda

Publications and source records attributed to C Miranda.

At least 55 records · Page 3Linked to original sources
PubMed1996

Intraoral non-Hodgkin's lymphoma in seven patients with acquired immunodeficiency syndrome.

Since the appearance of AIDS, there has been a significant increase in the number of cases of oral non-Hodgkin's lymphoma. Rarely seen in the oral cavity before, non-Hodgkin's lymphoma is now seen with some frequency in HIV-positive patients. Oral HIV-related lymphomas exhibit an aggressive course and can mimic other oral tumors and infections, which makes early recognition and diagnosis important and difficult. We report on the clinical findings in seven homosexual men in whom the oral cavity was the first site in which non-Hodgkin's lymphoma appeared and the only site involved at the time of diagnosis. Treatment consisted of chemotherapy with or without radiation therapy. The relatively short survival in these patients averaged 8 months. All patients died of complications from their tumor.

Adult↗
PubMed1996

[Occurrence of American cutaneous leishmaniasis by remote sensing satellite imagery in an urban area of Southeastern Brazil].

The areas in which american cutaneous leishmaniasis was reported in 1993 and 1994 for the region around the town of Lagoinha, S. Paulo, Brazil (Lat 23 degrees 05' S; Long 45 degrees 11w) were plotted on a TM-LANDSAT image. The false color composition of bands 3, 4 and 5 made it possible to identify the relevant vegetation (shrubs and trees) within the boundaries of those areas and in their proximity, where they were found at a distance of not more than about 250 meters from the perimeter of each area. The use of means capable of presenting a larger view of a geographical area made the advantages of remote satellite sensing as a tool for the study of this endemic disease clear.

Brazil↗
PubMed1996

The effect of hyperglycemia on nerve conduction and structure is age dependent.

The nerve conduction velocity (NCV) of nondiabetic male Wistar rats continues to increase until approximately 26 weeks of age. Rats made hyperglycemic at 6 weeks of age manifest reduced NCV by 10 weeks of age and show morphological differences in the sciatic tibial nerve after 5 months of hyperglycemia when compared with age-matched controls. Fiber diameter, myelin width, and the number of large myelinated fibers were decreased in the tibial nerves of the hyperglycemic animals. Rats made hyperglycemic at 26 weeks of age had elevated glycosylated hemoglobin and sciatic nerve sorbitol levels but maintained normal NCVs and had little change in morphology after 7 months of hyperglycemia. Thus, animals with maturing peripheral nerve structure and function exposed to chronic hyperglycemia manifest greater pathological alterations than those that occur when more matured nerves are exposed to similarly elevated glucose concentrations for an even greater duration. We suggest that immature animal models commonly used to study diabetic peripheral neuropathy may not be appropriate for understanding a process that commonly develops in humans who become hyperglycemic after maturation of the peripheral nerves.

Age Factors↗
PubMed1996

Oral hairy leukoplakia in an HIV-negative patient with systemic lupus erythematosus.

Oral hairy leukoplakia (OHL) has been reported primarily in association with HIV infection. Recently, cases have been reported in HIV-negative immunosuppressed and in immunocompetent patients. This article reports the case of an occurrence of OHL in an HIV-negative immunosuppressed patient with systemic lupus erythematosus. The case presented illustrates the importance of a thorough examination of the oral tissues in patients who are undergoing immunosuppressive therapy.

Candidiasis, Oral↗
PubMed1995

RET activation by germline MEN2A and MEN2B mutations.

The RET proto-oncogene encodes a receptor tyrosine kinase (TK). It has been shown that distinct germline mutations in the RET proto-oncogene are associated with the dominantly inherited cancer syndromes multiple endocrine neoplasia type 2A and 2B (MEN 2A and MEN 2B) and familial medullary thyroid carcinoma (FMTC) as well as Hirschsprung disease (HSCR), a congenital disorder characterised by absent enteric innervation. In this study, we have transfected NIH3T3 and PC12 phaeochromocytoma cells with MEN2A (Cys634-> Arg) and MEN2B (Met918-> Thr) RET constructs. Both caused transformation of the NIH3T3 cells and differentiation of PC12 cells. The Ret (MEN2A) and Ret (MEN2B) proteins were constitutively phosphorylated on tyrosine, and their in vitro kinase activity was significantly higher than that of the wild type protein. The MTC cell line TT carries a CYs634-> Trp MEN2A mutation, and we have shown by immunoelectronmicroscopy that Ret is clustered on the cell surface in a manner reminiscent of ligand-induced aggregation of cell surface receptors. RET is activated, as RET/PTC oncogene, by somatic rearrangements which link the TK domain to a constitutive dimerization interface in papillary thyroid carcinomas. We have compared the biological and biochemical activity of the TK domains of the wild type and MEN 2B Ret in the context of the RET/PTC. The results show that the MEN 2B mutation significantly increases the TK domain enzymatic activity suggesting that dimerization may be still necessary for MEN 2B Ret to express its full activity.

3T3 Cells↗
PubMed1995

Loss of function effect of RET mutations causing Hirschsprung disease.

We have introduced three Hirschsprung (HSCR) mutations localized in the tyrosine kinase domain of RET into the RET/PTC2 chimaeric oncogene which is capable of transforming NIH3T3 mouse fibroblasts and of differentiating pC12 rat pheochromocytoma cells. The three HSCR mutations abolished the biological activity of RET/PTC2 in both cell types and significantly decreased its tyrosine phosphorylation. By contrast, a rare polymorphism in exon 18 does not alter the transforming capability of RET/PTC2 or its tyrosine phosphorylation. These data suggest a loss of function effect of HSCR mutations which might act through a dominant negative mechanism. Our model system is therefore capable of discriminating between causative HSCR mutations and rare polymorphisms in the tyrosine kinase domain of RET.

3T3 Cells↗
PubMed1995

The use of focus group interview in the evaluation of patients with ankylosing spondylitis.

The purpose of this study was to develop some of the focus group discussion (FGD) potentialities in order to provide information on patients' understanding of the origin and management of their medical condition. Fifteen ankylosing spondylitis (AS) patients (mean age = 32.6 yr and mean disease duration = 13.4 yr) were selected from the Rheumatic Disease Unit (RDU) out-patient clinic at Escola Paulista de Medicina, São Paulo, Brazil, to take part in this study. The FGD constituted two sessions, with eight patients in the first and seven in the second. The moderator raised specific questions about the patients' understanding of the pathology, the treatment and how the illness affected their quality of life. It was observed through the FGD that patients believed that their illness onset was due to some physical trauma. Clinicians should inquire about this tissue to be sure that their individual patients do not have this false belief. Also, it is necessary to improve the methods for early diagnosis and to develop further studies to determine and assess the parameters of disease activity. And finally, FGD may be of use in establishing a self-help group for individuals with chronic diseases, such as AS. In conclusion the FGD is an available technique that should be used more frequently in medicine to gather global qualitative data.

Adult↗
PubMed1995

The DNA rearrangement that generates the TRK-T3 oncogene involves a novel gene on chromosome 3 whose product has a potential coiled-coil domain.

Oncogenic rearrangements of the NTRK1 gene (also designated TRKA), encoding one of the receptors for the nerve growth factor, are frequently detected in thyroid carcinomas. Such rearrangements fuse the NTRK1 tyrosine kinase domain to 5'-end sequences belonging to different genes. In previously reported studies we have demonstrated that NTRK1 oncogenic activation involves two genes, TPM3 and TPR, both localized similarly to the receptor tyrosine kinase, on the q arm of chromosome 1. Here we report the characterization of a novel NTRK1-derived thyroid oncogene, named TRK-T3. A cDNA clone, capable of transforming activity, was isolated from a transformant cell line. Sequence analysis revealed that TRK-T3 contains 1,412 nucleotides of NTRK1 preceded by 598 nucleotides belonging to a novel gene that we have named TFG (TRK-fused gene). The TRK-T3 amino acid sequence displays, within the TFG region, a coiled-coil motif that could endow the oncoprotein with the capability to form complexes. The TRK-T3 oncogene encodes a 68-kDa cytoplasmic protein reacting with NTRK1-specific antibodies. By sedimentation gradient experiments the TRK-T3 oncoprotein was shown to form, in vivo, multimeric complexes, most likely trimers or tetramers. The TFG gene is ubiquitously expressed and is located on chromosome 3. The breakpoint producing the TRK-T3 oncogene occurs within exons of both the TFG gene and the NTRK1 gene and produces a chimeric exon that undergoes alternative splicing. Molecular analysis of the NTRK1 rearranged fragments indicated that the chromosomal rearrangement is reciprocal and balanced and involves loss of a few nucleotides of germ line sequences.

3T3 Cells↗
PubMed1995

Treatment of human chronic fascioliasis with triclabendazole: drug efficacy and serologic response.

Between November 1990 and March 1992, 24 asymptomatic individuals in Chile with chronic hepatic fascioliasis confirmed by the presence of Fasciola hepatica eggs in feces were treated with a single oral dose of triclabendazole (10 mg/kg of body weight) after an overnight fast. Nineteen (79.2%) of 24 patients were egg-negative two months after treatment. Three of five cases with F. hepatica in feces after the first treatment were retreated and parasitologic cure was achieved. Tolerance to the drug was excellent; none of the patients had either secondary symptoms or important alterations in levels of aspartate and amino transferases, alkaline phosphatase, or bilirubin during or after treatment. Mild eosinophilia, present in 70% of the cases, persisted at least until 60 days after treatment. An enzyme-linked immunosorbent assay (ELISA) was highly effective in diagnosis and post-treatment monitoring. Before treatment, 20 (83.3%) of 24 confirmed cases had positive test results. The test results became negative by the second month of treatment in 40% of the cured cases. This percentage increased progressively, reaching 91.3% at 12 months after therapy. In the five cases in which treatment failed, the ELISA results remained positive until the end of the follow-up period (six months). In three of these cases who accepted a second round of therapy with triclabendazole six months after the first treatment, the ELISA results became negative in all three six months after parasitologic cure and remained negative until the end of the period. Due to its efficacy, excellent tolerance, and ease of administration (a single oral dose), triclabendazole appears to be the drug of choice for chronic human fascioliasis.

Administration, Oral↗
PubMed1995

[Spontaneous intracerebral hemorrhage: case histories].

Spontaneous intracerebral hemorrhage is a significant cause of morbidity and mortality. The disease primarily affects men between the age of 45 to 75 years. Arterial hypertension is the most frequent etiologic factor. Here is presented a case-record of 148 intracerebral hemorrhages observed during a five years period. Several clinical and radiological features have been correlated and analyzed from a statistical point of view. The most important prognostic factor is the state of consciousness. Either deep coma and a normal state of consciousness do not represent surgical indications.

Adult↗
PubMed1995

[Family counseling in infertility couples].

For couples who want to have children, infertility is an undesirable situation. Certain emotions both obvious and hidden can emerge which could complicate the clinical picture and the couple's relationship. Fifteen infertile women between the ages of twenty five and forty were interviewed and invited to form workshops to identify the emotions evoked by infertility. The spontaneous expressed emotions were; fear, anxiety, frustration loneliness and sadness. The non expressed emotions were; rage and guilt. Women held themselves more responsible for the couple's infertility and generally protected their partners even when male factors were the evident cause. Men showed scant interest iin joining infertility workshops. Family orientated advice is vital in the management of the infertile couple both in the diagnosis and treatment.

Adult↗
PubMed1994

[Assessing the functional ability of a group of elderly people using COOP-WONCA charts].

OBJECTIVE: To describe the functional ability of elderly people and analyse its relationship to the use of services. DESIGN: A crossover study. SETTING: An urban population within the metropolitan area of the Community of Madrid. PARTICIPANTS: A random sample of 300 people over 70, taken from the municipal census. MEASUREMENTS AND MAIN RESULTS: Functional ability was measured with COOP-WONCA sheets. 25% of the individuals chosen were excluded due to mistakes in the census. Almost half of the elderly people stated that their health was mediocre or poor; half that their physical ability was limited in some important way; and 37% that their frame of mind caused them some or considerable discomfort. Women perceived their health status as poorer than men did. The number of stated chronic health problems and frame of mind were the most important factors for forecasting use of services. CONCLUSIONS: The prevalence of disturbances in functional ability is high in elderly people. Among the different dimensions of functional ability, frame of mind is that which best forecasts use of primary care clinics.

Aged↗
PubMed1994

Diagnostic and prognostic accuracy of the exercise electrocardiogram in patients with preexisting right bundle branch block.

The value of exercise testing in patients with right bundle branch block (RBBB) is uncertain. A retrospective review of 3609 patients who underwent exercise testing identified 163 (4.5%) with preexisting RBBB. After excluding those with coronary artery bypass graft(s), 133 patients remained and 48 (36%) had a prior myocardial infarction. Angiograms were available for 30 (23%) patients. After a mean follow-up of 33 +/- 23 months, seven patients had a fatal or nonfatal myocardial infarction. Twenty five (19%) patients had > or = 1 mm of non-upsloping ST depression in leads V5 or V6. With angiographic disease or previous myocardial infarction used as endpoints of coronary artery disease, the exercise test had a sensitivity of 27% (15/56), a specificity of 87% (67/77), and a predictive accuracy of 62% (82/133), (chi 2 = 4.04, p = 0.04). There were 24 deaths, a 10% annual mortality rate. Univariate analysis of clinical, exercise, and angiographic data revealed that nonsurvivors had a lower peak systolic blood pressure, a lower exercise capacity in METS, and a higher prevalence of coronary artery disease (p = 0.0001, p = 0.02, p = 0.03, respectively). Left ventricular ejection fraction and the amount of additional ST depression during exercise did not differ significantly (p = NS). Receiver operating characteristic curve analysis revealed that systolic blood pressure (area = 0.741, z = 5.22, p < 0.001) and exercise capacity (area = 0.66, z = 3.12, p = 0.009) were predictive of mortality, whereas additional ST depression during exercise (area = 0.588, z = 0.70, p = 0.24) was not.(ABSTRACT TRUNCATED AT 250 WORDS)

Bundle-Branch Block↗
PubMed1994

Double-blind clinical trial of 0.05% clobetasol propionate (corrected from proprionate) ointment in orabase and 0.05% fluocinonide ointment in orabase in the treatment of patients with oral vesiculoerosive diseases.

Because of their chronic nature treatment of oral vesiculoerosive diseases remains a challenge to the oral medicine specialist. Even though oral vesiculoerosive diseases respond well to systemic steroids, adverse side effects sometimes limit their use. Potent topical steroids are becoming increasingly useful to treat these chronic conditions with good control. The purpose of this double-blind clinical trial was to compare clobetasol propionate and fluocinonide ointment in orabase as treatments for controlling oral vesiculoerosive diseases. Sixty patients were asked to participate (43 women and 17 men). Data are reported for 55 patients. Each patient was seen at baseline and at days 7, 14, 21, and 28. Variables evaluated were pain, erythema, atrophy, and size of lesion. Overall, both medications had a beneficial effect in the control of symptoms and signs of oral vesiculoerosive diseases with minimal side effects. Clobetasol propionate was better than fluocinonide as measured by more rapid control of pain (within 7 days). Candidiasis was observed in 13 patients at the end of treatment (most of them carriers of Candida). Therefore normal carriers should be identified and treatment with antifungal therapy instituted before the patient begins using topical steroids.

Aged↗
PubMed1994

Characterization of gap junctions between pairs of Leydig cells from mouse testis.

Leydig cells are coupled in vivo by numerous gap junctions. In vivo and in vitro cells were immunolabeled by connexin 43 (Cx43) but not by Cx26 or Cx32 antibodies; immunoblotting confirmed specificity of Cx43 labeling. Pairs of Leydig cells dissociated from mouse testis were studied by dual whole cell voltage clamp, and a high incidence of dye (n = 20) and electrical coupling (n = 60; > 90%) was found. Coupling coefficients were near 1 and junctional conductance (gj) averaged 7.2 +/- 1.2 nS (SE, n = 40). Large transjunctional voltage (Vj) decreased gj; currents decayed exponentially with time constants of seconds that decreased at greater Vj. The residual conductance at large Vj was at least approximately 40% of the initial conductance. Exposure of cell pairs to saline solutions saturated with CO2 (n = 15) or containing 2 mM halothane (n = 15) or 3.5 mM heptanol (n = 15) rapidly and reversibly reduced gj. In eight cell pairs, gating of single junctional channels was observed during halothane-induced reduction in gj. Most gating events at Vj < 40 mV were fit by a Gaussian distribution with a mean of approximately 100 pS. With Vj > 40 mV, smaller transitions of approximately 30 pS were also recorded, and the frequency and duration of the approximately 100-pS transitions decreased. Also, approximately 70-pS transitions between 30- and 100-pS conductances were observed in the absence of 70-pS transitions to or from the baseline, indicating that the 30-pS conductance was a substate induced by large Vj.

Alcohols↗