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Biomedical subjects

A Maciel

Publications and source records attributed to A Maciel.

15 recordsLinked to original sources
PubMed2001

Experience with demucosalized ileum for bladder augmentation.

OBJECTIVE: To assess the use of demucosalized ileum for bladder augmentation, following the same principles previously used with the sigmoid colon. PATIENTS AND METHODS: Eleven patients with bladder exstrophy or a neurogenic bladder had their bladders augmented with demucosalized ileum instead of the sigmoid colon, but following the same technique. The use of a Foley catheter with an inflated balloon greatly facilitated the dissection of the mucosa from the muscle. A silicone model, inserted in the bladder, was used to avoid shrinkage of the patch. An animal model was also used for total bladder replacement following the same principle. RESULTS: The mean (range) follow-up was 15.4 (2-25) months. There was a significant increase in bladder compliance in all patients. A bladder of good shape and compliance was obtained in the animal model, with epithelial growth detected in all cases. CONCLUSIONS: Demucosalized ileum can be used safely for bladder augmentation in the same way as with the sigmoid colon. The distension of the isolated patch greatly facilitates dissection between the mucosa and muscle. The animal model supported this method of bladder replacement.

Adolescent↗
PubMed1998

Risk factors for the occurrence of bancroftian filariasis infection in children living in endemic areas of northeast of Brazil.

The objective of this study was to identify biological and social risk factors for the occurrence of microfilaraemia in a population of 1464 children of both sexes aged 5-14 years, living in two highly endemic areas of Recife a city in the northeast of Brazil. A survey was performed from December 1990 to July 1991 and the microfilaraemia was examined by the thick-drop technique using 45 microliters of peripheral blood. Information was obtained about use of bednet, length of time living in area and number of occupants per household. Risk was quantified by the crude and adjusted Odds Ratio. The 95 per cent confidence interval, Likelihood Ratio Statistics, and P value were used to test the statistical significance. An association was established between microfilaraemia in children and adolescents, and age, number of individuals per household, the presence of microfilaraemic adults in the household, length of time living in the area, and bednet use. Maternal microfilaraemia was not found to be a risk factor for the occurrence of microfilaraemia in offspring. These results allow the identification of children with a greater risk of microfilaraemia. In addition, these findings highlight the role of the household environment in the transmission process.

Adolescent↗
PubMed1997

Low-risk human papillomavirus types 6 and 11 associated with carcinomas of the genital and upper aero-digestive tract.

BACKGROUND: Human papillomavirus (HPVs) types 6 and 11, are frequently found in non-malignant anogenital condylomas and laryngeal papillomas. However, in an ongoing epidemiological study in Argentina in which 163 anogenital and aero-respiratory cancer biopsies were analyzed, several cases infected with low-risk HPVs could be detected. METHODS: Tumor samples were analyzed by Southern blot hybridization, using HPVs 6, 11, 16, 18, 30, 31, 33 and 35 as probes, and polymerase chain reaction (PCR) with type-specific primers and probes. RESULTS: Four invasive carcinomas containing HPV 6 or 11 could be detected (2.4%) by Southern blot technique. HPV 6 DNA was found in a penile carcinoma, a groin carcinoma, and in a tonsillar carcinoma. One cervical carcinoma harbored HPV 11 DNA. Using HPVs 6, 11, 16, 18 and 33 anticontamination primers and probes in PCR, no additional high-risk HPV types could be detected in these four cancers. CONCLUSION: This report shows the presence of low-risk HPVs (HPV 6 and 11) associated to malignant tumors in a frequency higher than usually observed. The data raise questions about which are the circumstances which may favor low-risk HPV related oncogenesis.

Blotting, Southern↗
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

[Integrated control of the filariasis vector with community participation in an urban area of Recife, Pernambuco, Brazil]

A pilot study for the control of Bancroftian filariasis transmission was developed in two areas of Recife, Brazil, where microfilaraemic prevalence was 10% in 1991. Mass treatment with diethylcarbamazine (DEC) using low and spaced doses was employed in both areas. In one such instance, DEC therapy was associated with vector control using physical measures and periodic treatment of Culex breeding sites with the entomopathogen Bacillus sphaericus. The vector population density, reaching 60 - 120 Culex/room /night before the intervention, was drastically reduced to 4 - 16 Culex/room/night, and maintained at this level for more than two years. Actions to engage the local school community in the vector control process were implemented, and as a consequence several classroom and extracurricular activities were put into practice, culminating with the effective participation of a team of students called the "Vector Vigilantes", in the application of control measures against the vector. The enthusiastic involvement of schoolteachers and students pointed to schools as a place amenable to programs such as this.

Journal Article↗
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

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↗
PubMed1989

Implications for evolution of nuclear structures of animals, plants, fungi and protoctists.

The evolutionary variations of nuclear structure of animals, plants, fungi and protoctists were studied with electron microscopy by using techniques preferentially staining ribonucleoprotein (RNP) particles and chromatin. A remarkable similarity in the general morphological features of the RNP particles and chromatin arrangement is found in animals, plants and fungi. Important variations of these features were found in protoctists. These observations suggest that major evolutionary changes in the nuclear structure predate the acquisition of plastids by the ancestors of green plants. Once evolved, the nuclear structural pattern is conserved in plants and animals. Among protoctists studied, Kinetoplastida, Cryptomonadida and Volvocida have RNP particles and chromatin arrangement resembling those of plants and animals. These similarities may indicate a common ancestor. Important differences in the nuclear structure among Euglenida, Amebida, Cryptomonadida, Volvocida and Kinetoplastida support the view that Sarcomastigophora is a polyphyletic taxon. For the same reason Kinetoplastida and Euglenida must not be grouped in a monophyletic taxon. We propose that the variations of RNP particles may be related to the initial evolution of post-transcriptional processing.

Animals↗
PubMedDate not supplied

Efficacy of Bacillus sphaericus in control of the filariasis vector Culex quinquefasciatus in an urban area of Olinda, Brazil.

The efficacy of Bacillus sphaericus 2362 against Culex quinquefasciatus was tested in 1991-94 in a major Brazilian endemic zone for bancroftian filariasis. Continuous selection pressure against the mosquito population was sustained for 18 months through treatment of 2500 potential breeding sites occurring within a 5.7-km2 urban area in the Metropolitan Region of Recife. The impact of this control intervention was evaluated by comparing entomological indices with those from an untreated area. Application of the larvicide kept the Cx. quinquefasciatus population density significantly lower when compared to the untreated area, despite some operational difficulties. Adult densities remained lower for at least 5 months after spraying ceased. Pre-trial microfilaria rates from the untreated and operational area were 13.1% and 7.2%, respectively. A 60% reduction in human exposure to infective bites was recorded as a consequence of this vector population control.

Animals↗
PubMedDate not supplied

Epidemiological study of bancroftian filariasis in Recife, northeastern Brazil.

Wuchereria bancrofti in Pernambuco was first documented in 1952 (Azevedo & Dobbin 1952), and since then it has been reported in surveys carried out in selected areas of Recife. Several surveys were carried out from 1981 to 1991 by SUCAM. In the 1985 SUCAM's report the disease is considered under control. The CPqAM Filariasis Research Program was established in 1985 and a filarial survey was carried out in the town of Olinda, Greater Recife. In order to verify the real epidemiological situation, a study was conducted in the city of Recife. 21/36 of the Special Zones of Social Interest (ZEIS), were randomly selected for the present study. From 10,664 persons screened, 683 were positive and the prevalence rate for microfilaraemia (mf) varied from 0.6% to 14.9%. A mean mf prevalence of 6.5%, showed that the infection occurs in a wide geographic distribution in Greater Recife and that the intensity of transmission is a real and potential threat to public health in affected communities. Mf rate among males and females differed significantly. Due to the rapid increase in population, unplanned urban settlements, poor sanitary facilities and the favorable geographical conditions to the development of the vector, filariasis may actually be increasing in Recife.

Adolescent↗
PubMedDate not supplied

[Views on the municipalization of lymphatic filariasis control in greater metropolitan Recife].

Lymphatic filariasis is caused by the nematodes Brugia malayi, Brugia timori, and Wuchereria bancrofti. The disease occurs in developing countries and is more frequent in urban areas. An estimated 4 billion people live in at-risk areas. In Brazil the endemic is caused by W. bancrofti and was first documented in 1878. It was first detected in Recife in 1952. Currently, Recife and Belém are the only cities in Brazil where the endemic is considered a public health problem. The objectives of this study are to discuss the epidemiology and control of lymphatic filariasis and review its control since it was reported by Rachou in 1952. We analyze the "campanhista" or campaign-oriented model employed by the Sucam/FNS institutional program, as well as several proposed innovative methods. We present available strategies for control of filariasis through primary health care services, decentralization to the local level (or "municipalization"), and community-based health programs.

Animals↗
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↗