Biomedical subjects

C Braga

Publications and source records attributed to C Braga.

47 records · Page 3Linked to original sources

PubMed1996

Very late antigen-4/vascular cell adhesion molecule-1 (VLA-4/VCAM-1) pathway is involved in the transendothelial migration of lymphocytes in bancroftian filariasis.

The role of endothelial vascular cell adhesion molecule-1 (VCAM-1) in the trafficking of lymphocytes from the vascular circulation through endothelium and into sites of filarial inflammation was investigated in asymptomatic microfilaremic (MF; n = 16) and in patients with filaria-associated lymphatic pathology (LP; n = 23). When compared, by human umbilical vein endothelial cell ELISA, with PBMC supernatants generated from MF patients, filarial Ag (Brugia malayi adult Ag (BmA))-stimulated supernatants from LP patients stimulated over 50% more VCAM-1 (lymphatic pathology (LP) = 0.377 relative ELISA units vs MF = 0.246; p = 0.02). No difference was seen between patient groups with nonfilarial Ag (streptolysin O)-stimulated supernatant (LP = 0.160 relative ELISA units vs MF = 0.166). BmA-stimulated supernatants from LP patients stimulated significantly more T cell migration (percentage of relative migration LP = 79.9% vs MF = 25.8%; p = 0.01) through tightly confluent human umbilical vein endothelial cell monolayers cultured on collagen gels. Anti-VCAM-1 inhibited the increased T cell migration induced by BmA-stimulated supernatants by 97.7%, anti-VLA-4 by 74.7%, and blockade of NF-kappa B-dependent VCAM-1 transcription with 50 microM pyrrolidine dithiocarbamate resulted in 87.7% inhibition. Biopsies from 87.5% of the LP patients, but only 38.5% of the MF patients, demonstrated VCAM-1 on vascular endothelium. BmA-stimulated supernatants pretreated with anti-IL-1 alone resulted in VCAM-1 expression that was 23.7% of that with untreated supernatants while anti-IL-4, anti-IFN-gamma, or anti-TNF alone had essentially no effect on VCAM-1 expression.

Adolescent↗

PubMed1996

Fertility treatment and risk of breast cancer.

The relationship between fertility treatment and breast cancer was investigated in a multicentric case-control study conducted in Italy on 2569 women with incident, histologically confirmed breast cancer and 2588 control women admitted to hospitals for acute, non-neoplastic, non-hormonal or gynaecological conditions, unrelated to fertility problems. The odds ratio of breast cancer was 1.08 (95% confidence interval 0.8-1.5) in those reporting fertility treatment compared with those who did not receive fertility treatment. Similarly, the odds ratio was 0.60 for women with tubal occlusion, 0.99 for those reporting hormonal imbalances and 1.32 for other/unspecified reasons. There was no consistent pattern of risk according to age at treatment and time since treatment. Women reporting fertility treatment with drug use had an odds ratio of 1.43, while those who did not report drug therapy had an odds ratio of 0.85. None of these odds ratio estimates was significant. Likewise, there was no heterogeneity among strata of parity, menopausal status, education and family history of breast cancer. Thus, our study, while providing reassuring evidence on the relationship between fertility treatment and breast cancer risk, cannot exclude the possibility that the use of specific drugs may be related to breast carcinogenesis.

Adult↗

PubMed1996

Cigarette smoking and the risk of breast cancer.

The relation between cigarette smoking and breast cancer risk was investigated in a multicentric case-control study conducted in Italy on 2,569 women with incident, histologically confirmed breast cancer and 2,588 control women admitted to hospital for acute, non-neoplastic, non-hormonal, non-gynaecological or smoking-related conditions. Compared with women who had never smoked, current smokers had a multivariate odds ratio (OR) of 0.84 [95% confidence interval (CI) 0.7-1.0] and former smokers an OR of 1.14 (5% CI 0.9-1.4), while the OR for ever vs never smokers was 0.93 (95% CI 0.8-1.1). The ORs were 1.02 for < 5 cigarettes per day, 0.99 for 5-14 cigarettes per day, 0.78 for 15-24 cigarettes per day and 1.18 for > or = 25 cigarettes per day. No consistent pattern of risk was observed according to duration of smoking, age at starting and time since starting smoking. Compared with never smokers, former smokers had ORs of 1.45 for < 3 years since stopping smoking, 1.79 for 3-6 years, 1.16 for 7-15 years and 0.74 for > or = 16 years. No heterogeneity emerged across strata of selected covariates. Thus, this study, one of the largest conducted in Europe to date, does not support the presence of any association of practical importance between cigarette smoking and breast cancer risk.

Adult↗

PubMed1995

Abnormal lymphatic function in presymptomatic bancroftian filariasis.

Despite the common association of filarial infection with elephantiasis, the great majority of those infected are in fact clinically asymptomatic microfilariae carriers. The assumption has been that infection but not disease exists in these presymptomatic persons. In an area Brazil where Wuchereria bancrofti is endemic, flow studies done with dynamic radionuclide lymphoscintigraphy were used to compare 30 limbs from asymptomatic microfilaremic subjects with 16 control limbs. Geometric mean values for T1/2 (19.8 vs. 37.7 min; P < .001), appearance time (7.9 vs. 27.9 min; P < .001), percent uptake at the region of interest (0.67% vs. 0.14%; P < .001), and peak activity (62.6 vs. 2.6 cps; P < .001) each indicated an enhanced pattern of rapid, increased lymph flow in asymptomatic microfilaremic subjects. The abnormal lymphatic function in these subjects indicates that current passive intervention strategies may need to change if the debilitating sequelae of this parasitic infection are to be avoided.

Adolescent↗

PubMed1995

Nitrosamine intake and gastric cancer risk.

The association between intake of N-nitrosodimethylamine (NDMA), the most commonly occurring of the volatile nitrosamines derived from foods, and gastric cancer risk has been investigated using data from a case-control study conducted in Northern Italy between 1985 and 1993, including 746 incident cases of gastric cancer and 2,053 controls admitted to hospital for acute, non-neoplastic and non-digestive tract diseases, not related to long-term modifications of diet. Information was collected on frequency of consumption of 29 food items, including selected sources of NDMA. Compared with subjects in the lowest tertile of NDMA intake, the odds ratios (ORs) were 1.1 in the intermediate and 1.6 in the highest tertile of intake. These estimates were not appreciably modified after allowance for total energy intake, other major dietary and non-dietary correlates of gastric cancer, and estimated intake of nitrite and nitrate: the multivariate OR for the highest NDMA intake tertile was 1.4 (95% CI 1.1-1.7). The association was consistent across strata of sex and age, but somewhat stronger in males and in subjects below age 60 (OR in the highest tertile, 1.8). Limitations of exposure assessment and absence of information on other N-nitrosamines preclude, however, any definite assessment of the possible role of exogenous N-nitrosamines in gastric carcinogenesis.

Adult↗

PubMed1995

Lymphoscintigraphic assessment of the effect of diethylcarbamazine treatment on lymphatic damage in human bancroftian filariasis.

Despite many millions of doses administered over the past 40 years, basic and crucial issues regarding the use, mode of action, and effectiveness of diethylcarbamazine (DEC) in many clinical situations remain unresolved. To directly investigate whether the well-known microfilaricidal and macrofilaricidal actions of DEC actually result in subsequent improvement in existing damage to lymphatic vessels or lymph nodes, 29 study subjects in Recife, Brazil were stratified into three groups according to the severity of clinical manifestations of lymphatic insufficiency. After baseline radionuclide lymphoscintigraphy was performed, subjects were treated with two courses of DEC separated by at least a six-month interval and then rescanned one year after the baseline scan. A side-by-side comparison of images obtained at baseline with those obtained at follow-up in 13 asymptomatic microfilaremic individuals, six individuals with filarial fever, and in 10 individuals with chronic pathology demonstrated essentially unchanged lymphatic morphology in all but one individual whose disease actually progressed in the face of therapy. We conclude that two 12-day treatment courses of DEC did not have a demonstrable direct or indirect effect on existing structural damage to the lymphatic system even in those individuals with preclinical disease.

Acute Disease↗

PubMed1995

Predominant CD8+ infiltrate in limb biopsies of individuals with filarial lymphedema and elephantiasis.

In 34 individuals with a spectrum of clinical manifestations of Bancroftian filariasis, we investigated whether immunoperoxidase-stained, random, superficial dermal biopsies could further elucidate the nature of the diffuse damage to superficial lymphatics that had been recently demonstrated by radionuclide lymphoscintigraphy. A total of 78% and 68% of limbs from patients with clinical disease and asymptomatic microfilaremia, respectively, contained EN4+PAL-E- lymphatic vessels that were abnormally dilated. The majority of subjects, regardless of clinical classification, had a CD3+ perivascular but not a perilymphatic infiltrate in tissues and no parasites were present. In contrast to those individuals with asymptomatic infection, a striking predominance of CD8+ T cells was found in the tissue of individuals with clinical disease. Tissue pathology consistent with cutaneous bacterial infection was not observed. The prominent perivenular and pericapillary mononuclear infiltrates likely indicate, in light of current understanding of lymphocyte recirculation, the extravasation of lymphocytes from the vascular circulation into the inflamed filarial tissue.

Animals↗

PubMed1994

Lymphoscintigraphic analysis of lymphatic abnormalities in symptomatic and asymptomatic human filariasis.

To obtain high-resolution radionuclide lymphoscintigraphic images of affected limbs in persons with both symptomatic and asymptomatic filarial infection, 36 volunteers were recruited from a Wuchereria bancrofti-endemic area of Recife, Brazil, for a prospective, controlled analysis. Subjects were stratified after determination of serologic and clinical determinants of filarial infection status. Widespread lymphatic abnormalities were found in clinically asymptomatic microfilaremic persons, who had been assumed to have infection but not disease. All patients with clinical manifestations of lymphatic pathology and marked abnormalities. No correlation was found between clinical findings and actual lymphatic function as demonstrated by lymphoscintigraphy. The initial diagnosis of lymphatic filariasis, whether asymptomatic or symptomatic, is based on nonimaging laboratory criteria. After diagnosis, lymphoscintigraphy is a valuable tool for initial assessment of any lymphatic damage. Changes in strategies for therapeutic interventions in asymptomatic microfilaremic persons, who are not usually aggressively treated, may be warranted.

Adolescent↗

PubMed1984

Computed tomography of gestational trophoblastic disease.

Twenty-two patients with gestational trophoblastic neoplasia (GTN) were examined by CT of the abdomen and pelvis to assess the usefulness of CT in the detection and staging of GTN. The most common manifestations of GTN by CT were an enlarged uterus in 16 of 20 patients (80%) with bilateral adnexal cysts in 12 of 22 patients (54%). Contrast enhancement of the uterus was inhomogeneous and the cysts were usually unilocular, ranging in size from 1.0 to 6.0 cm. Metastases were found in 13 of 22 cases (59%). Local extension into the broad ligament was present in 5 of 22 cases (23%). Pelvic or periaortic adenopathy or both was not present. Only one patient had liver metastases. We conclude that CT is a valuable tool in the evaluation of patients with GTN.

Adnexal Diseases↗

PubMedDate not supplied

[Evaluation of a social and environmental indicator used in the identification of lymphatic filariasis transmission in urban centers].

The concept of a "socially organized space" supported by new analytical techniques and mapping of health events has guided innovative methodological developments in public health interventions. This study aimed to evaluate a social/environmental indicator constructed with a scoring methodology to stratify areas in the city of Olinda by different levels of risk for Bancroftian filariasis transmission. The study mapped areas and the location of sample households and identified all residents ages 5 to 65 years as part of the parasitological survey. Among the 3,232 individuals who had blood samples taken, 42 were microfilaremic (1.3% prevalence). Global statistical analysis of filarial case distribution has suggested spatial clustering. Some 85.7% of positive individuals resided in the two strata with the highest transmission risk. The high sensitivity of the proposed indicator for predicting the places where the vast majority of filariasis cases occurred justifies its use in planning and implementing interventions.

Adolescent↗

PubMedDate not supplied

[Epidemiological pattern of lymphatic filariasis in children living in endemic areas].

OBJECTIVE: Lymphatic filariasis still represents a major public health problem in the city of Recife. In spite of the fact that previous surveys had already shown high frequency of microfilaraemia in pediatric population, the prevalence of filarial disease and the microfilaraemic pattern of this group were unknown. This paper describes the clinical-epidemiological pattern of filariasis in children and adolescents living in two highly endemic areas of Recife. METHODS: The parasitological survey was done through a census carried out between December 1990 and July 1991. Thick drop technique (45 micro l) was performed on a total of 1,464 children and adolescents between the ages of 5 and 14, of whom 967 were submitted to clinical examination. Positive cases had their blood recollected (60 micro l) to measure the microfilaraemic density. RESULTS: The microfilaraemia prevalence was 6.4 %. In the age groups of 5 to 9 and 10 to 14 a microfilaraemia prevalence of respectively 4.6% and 8.3% was observed. The microfilaraemic density varied from 3 to 864 microfilariae per 60 microl of blood, there having been no statistically significant difference between the sexes and age groups (p<0.05). 6 cases (0.6 %) of acute filarial disease and 11 of chronic filarial disease (1.1%) were identified, hydrocele being the principal manifestation found. Lymphadenopathy was found in 22% of the children, statistical association with microfilaraemia being observed (p<0.001). CONCLUSIONS: The results of the parasitological survey show the strong presence of children in the contingent of microfilaraemic individuals, indicating an early and intense exposure to filariasis in the population studied.

English Abstract↗