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Biomedical subjects

G Rocha

Publications and source records attributed to G Rocha.

At least 37 records · Page 2Linked to original sources
PubMed1996

Analysis of gene expression during experimental uveitis in the rabbit.

OBJECTIVE: To analyse the pattern of gene expression at the messenger RNA level during ocular inflammation in the rabbit. DESIGN: A gene screen assay was used to quantify specific binding over background (expression index) of various activation markers and cytokines in rabbit iris-ciliary body obtained during active experimental uveitis induced by injection of porcine lens protein (two animals) and in a control group (two animals). OUTCOME MEASURES: Expression indices corresponding to the activation markers and cytokines assayed. RESULTS: Compared with the control eyes, analysis of triplicate samples from the inflamed eyes showed a significantly higher expression index corresponding to the proto-oncogenes c-fos, c-jun and Ha-ras, interleukin-2 and heat shock protein Hsp27 and a significantly lower index corresponding to transforming growth factor-beta (TGF-beta) (p < 0.05). CONCLUSIONS: Active experimental lens-induced uveitis is associated with a significant rise in the gene expression of cellular activation factors and a decrease in an immunoprotective factor (TGF-beta) in the iris and ciliary body of the rabbit.

Animals↗
PubMed1995

Relationship between Legionella spp. and antibody titres at a therapeutic thermal spa in Portugal.

The presence of Legionella spp. in the water of a Portuguese spa was ascertained during the spa season, between May and November. Simultaneously the prevalence of anti-legionella antibodies in people attending the spa was also investigated. The antibody titres of 172 randomly selected patients and 42 therapists were determined, and compared with a control group of 503 blood donors. Legionellae were present in the spa water at low concentrations, generally lower than 10(3) c.f.u./l. A total of 92 strains representing eight different species or serogroups were isolated; the predominant isolates belonged to Legionella pneumophila serogroup 6 and to L. londiniensis. During the study, no clinical cases of Legionnaires' disease were observed, and the antibody titres were generally low in the groups studied. However, the antibody titres of the patients increased slightly during their stay at the spa, approaching the values for the therapists. Mean antibody titres in the groups related with the spa were significantly higher than those in the blood donors against five of the seven legionella antigens tested. The largest number of elevated antibody titres in the exposed groups were to the L. pneumophila sg 5 and sg 6 antigens.

Adult↗
PubMed1995

DNA index and S phase fraction in uveal malignant melanomas.

AIMS: To predict 5 year survival in patients with uveal malignant melanomas DNA indices were studied. METHODS: Using 45 paraffin embedded uveal malignant melanomas, the DNA index and S phase fraction of each tumour were the predictor variables recorded. RESULTS: Using the Cox proportional hazards model, aneuploid tumours and tumours which had an S phase fraction greater than 4% were significant predictors of early death. In order to demonstrate a biological gradient between a larger DNA index and shorter survival time, linear regression and transformed linear regression models were used. However, no such gradient could be demonstrated. CONCLUSION: Although this study shows promise for the use of DNA studies in the prognosis of uveal malignant melanoma, the exact role of these techniques remains to be determined.

Adult↗
PubMed1995

Severe toxic keratopathy secondary to topical anesthetic abuse.

OBJECTIVE: To describe the clinical findings in three cases of abuse of topically administered ophthalmic anesthetics and to review the clinical signs, diagnosis and treatment. DESIGN: Case series. SETTING: Two university-affiliated hospitals in Montreal. PATIENTS: Three patients with toxic keratopathy due to abuse of topically applied anesthetics. RESULTS: The three patients presented with a nonhealing epithelial defect, marked stromal edema, folds in Descemet's membrane and a typical stromal ring infiltrate. All three required a conjunctival flap, and two underwent penetrating keratoplasty. The drugs (0.5% tetracaine and 0.5% proparacaine) were easily obtained, at the workplace in two cases and by stealing from the ophthalmologist's examining room in the third case. CONCLUSIONS: The unrestricted availability of topically applied ophthalmic anesthetics as over-the-counter medications in Canada must be reevaluated.

Administration, Topical↗
PubMed1992

[Insulin secretion and sensitivity in patients with secondary failure to oral hypoglycemic drugs].

Secretion and peripheral sensitivity to insulin was investigated in diabetic patients with secondary failure to oral hypoglycemic drugs. 8 patients with secondary failure (non responders), 7 non insulin dependent diabetic patients with good response to oral drugs (responders) and 8 control subjects were studied. Insulin secretion was determined with peptide C in urine obtained 4h after a 500 Cal breakfast; in vivo insulin sensitivity was studied by the euglycemic hyperinsulinemic clamp technique. All groups were comparable in age, nutritional status and duration of diabetes. Non responders had higher fasting blood sugar levels compared to responders (228 +/- 70 vs 136 +/- 21 mg/dl, p < 0.05). Controls had lower blood sugar levels than the other 2 groups (93 +/- 8, p < 0.05). Insulin levels were similar in non responders and responders (24 +/- 12 and 16 +/- 9 uU/ml, respectively) and higher than in controls (10 +/- 3, p < 0.05). Peptide C was lower in non responders than in responders (3.8 +/- 1 vs 5.3 +/- 1.4 nm/4h, respectively, p < 0.04), but similar to controls (4.4 +/- 1.2). No difference in secretion of insulin was noted between non responders and responders. Insulin sensitivity index was 3.67 +/- 1.41 ((mg/kg.min)/(uU/ml)). 100 in non responders and 4.20 +/- 1.14 in responders; the index for controls was 7.92 +/- 1.70 (p < 0.05). These results show that non responders have normal insulin levels, although inappropriate for the level of hyperglycemia. Insulin sensitivity in non responders is similar to responders but lower than controls.(ABSTRACT TRUNCATED AT 250 WORDS)

Administration, Oral↗
PubMed1992

The immunology of the eye and its systemic interactions.

Advances in immunology have provided us with new insights about the ocular inflammatory response. Still, the etiology and pathophysiology of many uveitides remain unclear. Factors such as the blood-ocular barrier, sequestration of retinal antigens, local immunomodulators in the aqueous humor, and anterior chamber-associated immune deviation (ACAID) interact and render the eye an immunologically "privileged" site. On the other hand, human leukocyte antigen complex (HLA) interactions, the immunopathology of hypersensitivity reactions, T-cell mediated disease, and autoimmunity are associated pathogenic mechanisms of immune-related ocular disease. In this paper, we review some of the immunologic characteristics of the eye and their relationship to intraocular inflammation. Clinocopathologic correlations are presented. Also, perspectives of current and future research, as well as diagnostic and treatment strategies, are discussed.

Animals↗
PubMed1991

[Insulin sensitivity in vivo: evaluation of non insulin dependent diabetes mellitus patients and healthy subjects by euglycemic hyperinsulinemic clamp].

Insulin resistance is commonly found in non insulin dependent diabetic patients. We used the euglycemic hyperinsulinemic clamp method to measure in vivo sensitivity to insulin in 7 non insulin dependent patients responding to oral hypoglycemic agents (Diabetics) and in 8 healthy subjects (Control). Fasting blood sugar was 136 +/- 21 vs 93 +/- 8 mg/dl respectively (p < 0.0002). Basal insulin levels were 16 +/- 9 vs 10 +/- 3 uU/ml, respectively (NS). Sensitivity to insulin was higher in diabetics (4.2 +/- 1.14 (mg/kg/min)/(uU/ml) x 100)) than in controls (7.92 +/- 1.7, p < 0.01). Efficiency in the use of insulin was lower in diabetics (3.20 +/- 0.64 vs 6.50 +/- 1.42 ml/kg/min, p < 0.002). Thus, non insulin dependent diabetics exhibit resistance to insulin. Effective treatment with oral hypoglycemic agents does not normalize insulin sensitivity.

Blood Glucose↗
PubMed1987

Clinical experience with stentless pericardial aortic monopatch for aortic valve replacement.

A stentless pericardial aortic monopatch was used in 60 consecutive patients undergoing aortic valve replacement. The monopatch is constructed of a sheet of glutaraldehyde-treated bovine pericardium, tailored and shaped to fit the aortic anulus, and is sutured in place without a stent or sewing ring. The valve area is effectively preserved by this method. Results indicate that this technique is simple, inexpensive, and applicable to all cases of aortic valve disease. It does not require anticoagulation and may allow for annular growth when used in children. This technique is particularly suitable for patients with infective endocarditis because the amount of foreign material is minimized.

Adolescent↗