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Biomedical subjects

J Pinto

Publications and source records attributed to J Pinto.

At least 19 recordsLinked to original sources
PubMed2005

Plasmodium species mixed infections in two areas of Manhiça district, Mozambique.

We compared the distribution patterns of individual Plasmodium species and mixed-species infections in two geographically close endemic areas, but showing environmental differences. Comparisons concerned circulating Plasmodium infections in both human and mosquito vector populations in the dry and wet seasons, at a micro-epidemiological level (households). Both areas revealed a very high overall prevalence of infection, all year-round and in all age groups. Plasmodium falciparum was the predominant species, being found in the vast majority of infected individuals regardless of the presence of other species. Plasmodium malariae and Plasmodium ovale occurred almost exclusively in mixed infections. Seasonal variation in P. malariae prevalence was observed in one area but not in the other. A decrease in P. malariae prevalence concurred with a marked increase of P. falciparum prevalence. However this was strongly dependent on age and when analysing infections at the individual level, a different pattern between co-infecting species was unveiled. Regarding transmission patterns, in both areas, P. falciparum gametocytes predominated in single infections regardless of age and P. malariae gametocyte carriage increased when its overall prevalence decreased.

Adolescent↗
PubMed2005

Entomological characteristics of malaria transmission in Manhiça, a rural area in southern Mozambique.

From October 1997 to September 1998, an entomological survey was carried out in Manhiça, Mozambique, to describe the anopheline population and intensity of malaria transmission. Ten different huts were randomly selected for entomological surveillance throughout the year. CDC light trap collections were conducted during three nights each month. Additional knockdown spraying catches were carried out in the morning, after the last catch. A total of 17,245 Culicinae and 1,251 Anophelinae were collected during the study. There was substantial house to house variation and seasonality in the distribution of Anophelinae population, with a peak in April towards the end of the warm and rainy season. Four species of genus Anopheles (Diptera: Culicidae) were described: Anopheles funestus Giles, Anopheles tenebrosus Dönitz, Anopheles arabiensis Patton, and Anopheles merus Dönitz. An. funestus constitutes 72.3% of the anopheline population. The estimated sporozoite rate was 1.2% and the average entomological inoculation rate for the area was 15 infective bites per person per year.

Animals↗
PubMed2004

Revisiting the role of introgression vs shared ancestral polymorphisms as key processes shaping genetic diversity in the recently separated sibling species of the Anopheles gambiae complex.

The role of interspecific hybridisation in the evolution of pest species is poorly understood. In mosquito disease vectors this is of particular importance due to the evolution of insecticide resistance and the proposed release of transgenic strains that are refractory to the malaria parasite. In this study, we apply population genetic methods in a novel manner to determine whether mitochondrial DNA sequences have introgressed between the closely related African malaria vectors Anopheles gambiae and A. arabiensis. Our results suggest that speciation was geologically recent and ancestral haplotypes at the ND5 locus are retained in both species. In addition, comparing haplotype frequencies in allopatric and sympatric populations, suggest locale specific unidirectional introgression of mitochondria from A. arabiensis into A. gambiae.

Africa↗
PubMed2003

An island within an island: genetic differentiation of Anopheles gambiae in São Tomé, West Africa, and its relevance to malaria vector control.

Islands are choice settings for experimental studies of vector control strategies based on transgenic insects. Before considering this approach, knowledge of the population structure of the vector is essential. Genetic variation at 12 microsatellite loci was therefore studied in samples of the malaria vector Anopheles gambiae s.s., collected from six localities of São Tomé island (West Africa). The objectives were (i) to assess the demographic stability and effective population size of A. gambiae from these sites, (ii) to determine population differentiation and (iii) to relate the observed patterns of population structure with geographic, ecological and historical aspects of the vector on the island. Significant population differentiation, revealed by FST and RST statistics, was found between the southernmost site, Porto Alegre, and northern localities. The observed patterns of population substructure are probably a result of restrictions to gene flow in the less inhabited, more densely forested and mountainous south. In all localities surveyed, A. gambiae appeared to be experiencing a demographic expansion, consistent with a relatively recent (ca. 500 years) founder effect. The results are discussed with respect to current and future prospects of malaria vector control.

Africa, Western↗
PubMed2003

Mating does not affect the biting behaviour of Anopheles gambiae from the islands of São Tomé and Príncipe, West Africa.

To determine if mating or gonotrophic age influenced the biting behaviour of Anopheles gambiae s.s., a series of all-night landing captures was performed on the islands of São Tomé and Príncipe in the Gulf of Guinea. On São Tomé 49% and on Príncipe 56% of the newly emerged An. gambiae taking their first bloodmeal were virgins. On each island, with the exception of recently mated insects on Príncipe, all age-groups had similar biting cycles. The biting cycle on Príncipe resembled that observed on continental Africa, with a peak in the latter part of the night. Peak biting on São Tomé, however, occurred before midnight. Estimated daily survival rates were 0.77 and 0.29 for São Tomé and Príncipe, respectively. Mating does not affect the biting behaviour of An. gambiae on these islands.

Age Factors↗
PubMed2002

Male size does not affect mating success (of Anopheles gambiae in São Tomé).

For malaria control, the utility of transgenic vector Anopheles mosquitoes (Diptera: Culicidae) refractory to Plasmodium transmission, will depend on their interbreeding with the wild vector population. In many species, larger males are more successful in obtaining mates. In São Tomé island, we determined that size did not affect mating success of male Anopheles gambiae Giles sensu stricto, the main malaria vector in tropical Africa. Also we showed that larval intraspecific competition is probably insignificant in this population of An. gambiae. Thus, the potential success of transgenic An. gambiae is unlikely to be affected by size selection under field conditions.

Animals↗
PubMed2002

Genetic structure of Anopheles gambiae (Diptera: Culicidae) in São Tomé and Príncipe (West Africa): implications for malaria control.

The impact of a vector eradication programme, conducted in the 1980s, on Anopheles gambiae populations from the islands of São Tomé and Príncipe, was evaluated by microsatellite DNA analysis. Significant genetic differentiation was observed within and between the two islands and between the islands and a population from Gabon, suggesting a degree of isolation between them. Large estimates of long-term N(e) suggested that the control programme did not affect the effective population size of the vector. Heterozygosity tests were also not consistent with a recent bottleneck.

Africa, Western↗
PubMed2002

The swarming and mating behaviour of Anopheles gambiae s.s. (Diptera: Culicidae) from São Tomé Island.

The swarming and mating behaviours of the forest cytoform of Anopheles gambiae s.s. were investigated on 194 evenings and 14 mornings between April 1997 and November 1999 in a peri-urban area of the island of São Tomé, West Africa. Males swarmed 2-3 m above markers of horizontal contrast such as those formed between grass areas and footpaths, or bushes. Evening swarms started 2 min before sunset in sheltered sites and a minute or two later in exposed ones. It took approximately 5 mins from the arrival of the first male for the swarm to reach estimated maximum numbers. Mating pairs were first seen 7 min after the start of swarming. Maximum numbers of pairs in copula were observed 8 min later. Up to 270 pairings were seen in the 20 min period before darkness. Removal of males had no effect on the number of females arriving at the swarm. Males were attracted to sounds that approximated the female flight tone but not to filter paper samples of squashed virgin females swung through the swarm. A much-reduced amount of swarming and a single mating were recorded at dawn. The same locations for swarming were used at different times and at different heights by ants, Culicoides sp. and Culex quinquefasciatus.

Africa, Western↗
PubMed2001

The impact of indoor residual spraying with malathion on malaria in refugee camps in eastern Sudan.

An exploratory trial of the efficacy of indoor spraying with malathion on morbidity and mortality in refugee camps in eastern Sudan was conducted during the rainy season of 1997. The interior walls of houses from a randomly selected group of five camps were sprayed with malathion in mid-September and morbidity and mortality rates in the camps for the months October to December compared with rates in five controls. Pyrethrum spray collection and human landing catches were performed in two collection rounds. An exophagic but endophilic population of Anopheles arabiensis was the most common mosquito collected. The mean human blood index of 242 mosquitoes from eight camps was 0.51. Only two of 1040 mosquitoes examined harboured sporozoites. Blood samples of 83 putative malaria patients were examined for parasites by PCR. Mortality rates in the 3 months following spraying were significantly lower in sprayed camps although differences in clinical malaria incidence between sprayed and non-sprayed camps were not significant.

Animals↗
PubMed2001

A cavernous haemangioma of breast in male: radiological-pathological correlation.

Vascular tumours of the breast are especially rare in men, and a majority of them are angiosarcomas. In fact, we found only four cases of haemangioma in males in the literature. We present a case of cavernous haemangioma in a male aged 48 years, and which commenced as a palpable mass. We performed differential diagnosis and radiological-pathological correlation. We established the correct classification of this case histologically, and decided on the definitive therapeutic approach.

Biopsy, Needle↗
PubMed2001

Papillary adenoma of the kidney with mucinous secretion.

Although infrequently, mucin secretion has previously been reported in papillary renal cell carcinoma. We here investigate the presence of mucin in a series of 93 renal papillary adenomas in 58 patients. Acid mucin was present in four cases (4.3% of the tumors; 6.9% of the patients), in which basophilic mucin secretion was evident with hematoxylin-eosin. To the best of our knowledge mucin secretion has not been reported in renal papillary adenoma. We describe two different types of mucin secretion: intracytoplasmic and luminal. The secretion was intracellular in numerous scattered tumor cells in two cases, focal luminal in one case, and mixed intracellular and luminal in another case. Mucin production, despite its low frequency, can be considered as an additional feature of renal papillary adenoma. Mucin production suggests that renal papillary adenoma and papillary renal cell carcinoma are actually not two independent biological processes, but a continuum of one biological process.

Adenoma↗
PubMed2001

Dogs as a favored host choice of Anopheles gambiae sensu stricto (Diptera: Culicidae) of São Tomé West Africa.

The host source and human blood index (HBI) of an exophilic population of the "forest" cytoform of Anopheles gambiae Giles sensu stricto, from a peri-urban area of the island of São Tomé were assessed. Blood meals of 434 An. gambiae females from all-night indoor light-trap collections, 193 from indoor and 422 from outdoor resting collections, were determined by ELISA. Significant differences were found in the HBI estimates from insects collected indoors (0.93) and outdoors (0.27). Blood-fed insects collected resting outdoors provided the most representative sample for host determination. Dogs were the predominant hosts, followed by humans and pigs. Of all human feeds, it was estimated that 81.5% were taken inside houses. The low HBI of 0.27 for the An. gambiae population explains the low sporozoite rate and the meso-endemicity of malaria in the island.

Africa, Western↗
PubMed2001

Pagetoid dyskeratosis is a frequent incidental finding in hemorrhoidal disease.

BACKGROUND: Pagetoid dyskeratosis is considered a selective keratinocytic response in which a small part of the normal population of keratinocytes is induced to proliferate. Pagetoid dyskeratosis has been found incidentally in the squamous epithelium of the skin in various locations and in the ectocervix in uterine prolapse. In cases in which these pale cells are conspicuous, there is a hazard of overdiagnosis. It has been suggested that friction is the most probable inductor of the lesion. To the best of our knowledge, pagetoid cells have not been reported in surgically resected hemorrhoids. OBJECTIVE AND DESIGN: We here describe the location of pagetoid dyskeratosis in the squamous epithelium of hemorrhoids and the incidence of this lesion in a group of 100 unselected patients surgically treated for hemorrhoidal disease. In addition to the conventional histologic method, special staining procedures and an immunohistochemical study of cytokeratins were performed in selected cases. RESULTS: Pagetoid dyskeratosis was found in 68 cases (68%) and was a prominent finding in 22 cases (22%). The cells of pagetoid dyskeratosis were strongly positive for high-molecular weight cytokeratin. These cells showed an immunohistochemical profile that was different from that of the surrounding squamous cells and indicative of premature keratinization. CONCLUSIONS: In hemorrhoidal disease, the cushions are susceptible to trauma as a result of prolapse. In this setting, friction may be the stimulus for the appearance of pagetoid dyskeratotic cells. These cells must be distinguished from the artifactual clear cells of the squamous epithelium, glycogen-rich cells, and koilocytes. The lesion must also be distinguished from extramammary Paget disease, pagetoid spread of carcinoma cells, pagetoid Bowen disease, and pagetoid melanoma. Pathologists should be familiar with the histologic features of pagetoid dyskeratosis in hemorrhoidectomy specimens to avoid misdiagnosis. Routine histologic study is usually adequate for recognizing this lesion.

Adult↗
PubMed2001

Modified Active Surveillance System (MASS); a novel clinicopathological evaluation of PB leprosy patients after RFT, in Mangalore, India.

The current recommendations for leprosy control programmes include stopping active surveillance in view of the very low relapse rates and a phased integration of leprosy services with the general health services. Passive surveillance may not be adequate, more so because of the introduction of newer, shorter drug regimens. This study is an effort to evolve a modified active surveillance, which is cost-effective, simple and also a novel substitute for the increased workload caused by the dwindling number of PMWS. One thousand one hundred RFT-PB leprosy patients were recalled for a review under the Modified Active Surveillance System (MASS), carried out over two phases. Patients were divided into groups as per the mode of response to the mailed postcards; Responders (patients who reported to the OPD in person), Untraceables (patients whose postcards returned back) and non-responders (patients who did not report of the OPD after receiving the mail). At the end of phase I, we had 120 Responders, 480 Untraceables and 500 Non-responders. In phase II, which began 2 months later, the 500 non-responders were dispatched reminders. In this phase, there were 31 responders, 60 untraceables and 409 non-responders. Thus, at the completion of phases I and II, there were 151 responders, 540 untraceables and 409 non-responders. Of the 151 patients examined, 71 had no complaints (category 1), 41 had fresh leprosy-related complaints (category IIA), 14 had fresh leprosy-unrelated complaints (category IIB) and 25 had persistence of old complaints (category III). Cumulative PYR of the 151 patients was 1155.42. Forty-one patients had fresh leprosy-related complaints. Skin biopsy was done in the 17 patients with fresh skin patches, of whom four showed histopathological evidence of relapse. Relapse rate in our study was 0.35/100 PYR. Mean duration after RFT at relapse was 4.9 years. Our scepticism towards passive surveillance systems is justified by these 41 patients with fresh leprosy-related complaints, who voluntarily reported only after receiving the postcards. We recommend the introduction of a phase III, wherein the services of PMWs may be used to contact the 409 patients who remained unresponsive at the completion of phases I and II. We also recommend the introduction of a universal format for recording addresses of all new patients, which would be of immense help in patient retrieval in all such surveillance systems in the future.

Adolescent↗
PubMed2001

[Adult polyglucosan body disease: report of one case].

Adult polyglucosan body disease is a recently established clinicopathological entity, with few cases reported in the literature. In this paper we describe a case of a 46-year-old man who had died to a pancreatic cancer whose neuropathological study revealed a massive accumulation of polyglucosan bodies in the cerebral white matter, brainstem, cerebellum and spinal cord consistent with the adult polyglucosan body disease. We also discuss the pathological criteria used to differentiate this disease from others in which polyglucosan bodies may accumulate in the nervous system.

Central Nervous System Diseases↗
PubMed2000

Malaria in São Tomé and Príncipe: parasite prevalences and vector densities.

A cross-sectional survey was carried out in 16 localities on the island of São Tomé and three on the island of Príncipe, at the end of the rainy season of 1997, to determine malaria prevalence and vector densities. Blood samples from 664 inhabitants of all ages were examined by optical microscopy (OM) and PCR. Mosquito collections were made by outdoor landing captures from 21:00-23:00 h. Great differences were found between OM and PCR readings. OM had a sensitivity of 66%, a specificity of 79% and failed to reveal any mixed-infections. Overall prevalence, determined by PCR, was higher in São Tomé (53%) than in Príncipe (35%). It was highest in children below 16 years-old. All four human Plasmodium species occurred in São Tomé but P. ovale was not detected in Príncipe. The human population was largely asymptomatic. Bednet users had lower prevalence than did non-users. The FOREST form of Anopheles gambiae s.s., identified by PCR and cytogenetics, was the only vector on the islands. The sporozoite rate in São Tomé, assessed by ELISA, was 0.5%. Parasite prevalence and vector densities were positively correlated in São Tomé, where malaria transmission must occur predominantly in the more populated coastal areas.

Adolescent↗
PubMed2000

Ca(2+) transients and Ca(2+) waves in purkinje cells : role in action potential initiation.

Purkinje cells contain sarcoplasmic reticulum (SR) directly under the surface membrane, are devoid of t-tubuli, and are packed with myofibrils surrounded by central SR. Several studies have reported that electrical excitation induces a biphasic Ca(2+) transient in Purkinje fiber bundles. We determined the nature of the biphasic Ca(2+) transient in aggregates of Purkinje cells. Aggregates (n=12) were dispersed from the subendocardial Purkinje fiber network of normal canine left ventricle, loaded with Fluo-3/AM, and studied in normal Tyrode's solution (24 degrees C). Membrane action potentials were recorded with fine-tipped microelectrodes, and spatial and temporal changes in [Ca(2+)](i) were obtained from fluorescent images with an epifluorescent microscope (x20; Nikon). Electrical stimulation elicited an action potential as well as a sudden increase in fluorescence (L(0)) compared with resting levels. This was followed by a further increase in fluorescence (L(1)) along the edges of the cells. Fluorescence then progressed toward the Purkinje cell core (velocity of propagation 180 to 313 microm/s). In 62% of the aggregates, initial fluorescent changes of L(0) were followed by focally arising Ca(2+) waves (L(2)), which propagated at 158+/-14 microm/s (n=13). Spontaneous Ca(2+) waves (L(2)*) propagated like L(2) (164+/-10 microm/s) occurred between stimuli and caused slow membrane depolarization; 28% of L(2)* elicited action potentials. Both spontaneous Ca(2+) wave propagation and resulting membrane depolarization were thapsigargin sensitive. Early afterdepolarizations were not accompanied by Ca(2+) waves. Action potentials in Purkinje aggregates induced a rapid rise of Ca(2+) through I(CaL) and release from a subsarcolemmal compartment (L(0)). Ca(2+) release during L(0) either induced further Ca(2+) release, which propagated toward the cell core (L(1)), or initiated Ca(2+) release from small regions and caused L(2) Ca(2+) waves, which propagated throughout the aggregate. Spontaneous Ca(2+) waves (L(2)*) induce action potentials.

Action Potentials↗