Seasonal malaria transmission and variation of anopheline density in two distinct endemic areas in Brazilian Amazonia

Studies on seasonal anopheline fauna variation were performed in two distinct settlements in the State of Rond?nia, Brazil: one at the Madeira River banks (Portuchuelo) with stable native Amazonian population; the other at an inland lumber-extracting farm (Urupá) in dry land, in which adults are mostly migrants. During a 6-yr period (1994-2000), 8,638 adult anophelines were collected: 2,684 in Urupá and 5,954 in Portuchuelo. Anopheles darlingi represented >95% of total mosquitoes caught. Dissection of 4,424 A. darlingi females yielded a very low sporozoite infection index below 0.1%. Oocysts were found in both localities in approximately 0.1% of dissected mosquitoes. Determination of the hour biting rates disclosed seasonal variations in both localities. However, in Portuchuelo, mosquito density peaked at the acme of the rainy season, whereas at Urupá it peaked in the dry season. The increase in mosquito density and incidence of malaria cases were coincident. The high mosquito densities observed in the riverine settlement of Portochuelo sector B, which permits evaluation in > 10,000 mosquitoes' bites/person/year, could explain, in spite of the low mosquito's infection index, the previously described development of natural immunity in the local population that is not observed in the dry land agroindustrial settlement of Urupá.     

Vaccination of the Leishmania major susceptible BALB/c mouse. I. The precise selection of peptide determinant influences CD4+ T cell subset expression

BALB/c mice are susceptible to cutaneous lelshmanlasls uponinfection with Leishmania major while C57BL/6 are not. Thereis a major promastigote surface protease (PSP or gp63) whichis available in both native and recomblnant forms, and for whichthe primary amlno acid sequence is known. Immunization withPSP has been shown to offer some protection against challengewith the live organism. Therefore, we attempted to develop apeptide vaccine with PSP peptldes. In the first experiments,recall prollferatlve responses to PSP were measured using aset of 15mer peptldes spanning the entire PSP molecule whichallowed designation of major determinant regions in BALB/c,C57BL/6, and CBA mice. Several of these determinants were promiscuousand shared almost the identical core amlno acid residues inthe different strains. Immunization with major determinant peptldeswas recalled vigorously with L. major soluble antigen as wellas with PSP. The response to peptide was almost entirely T_h1as measured by a localized ELISA assay for single-cell productionof IFN-. A similar assay for IL-5, which overcomes problemsof sensitivity and inhibition by lymphoklnes produced by T_h1cells, Indicates very little production of T_h1 cells even byBALB/c. It was found that if a major responsive peak was examinedby recall with overlapping peptldes, the highest, central peptidegave a mainly Th1 response while the boundary, less efficientpeptldes gave more of a T_h2 response. Possible reasons for thiswere discussed. These results point to the importance of selectingthe exactly appropriate peptide in considering a vacclnogenthat might protect susceptible individuals. Even the choiceof a somewhat immunogenlc peptide within the determinant envelopemight actually exacerbate infection by steering the responsein a T_h2 direction.     

The three-dimensional scintillation dosimetry method: test for a 106Ru eye plaque applicator

The need for fast, accurate and high resolution dosimetric quality assurance in radiation therapy has been outpacing the development of new and improved 2D and 3D dosimetry techniques. This paper summarizes the efforts to create a novel and potentially very fast, 3D dosimetry method based on the observation of scintillation light from an irradiated liquid scintillator volume serving simultaneously as a phantom material and as a dose detector medium. The method, named three-dimensional scintillation dosimetry (3DSD), uses visible light images of the liquid scintillator volume at multiple angles and applies a tomographic algorithm to a series of these images to reconstruct the scintillation light emission density in each voxel of the volume. It is based on the hypothesis that with careful design and data processing, one can achieve acceptable proportionality between the local light emission density and the locally absorbed dose. The method is applied to a Ru-106 eye plaque immersed in a 16.4 cm3 liquid scintillator volume and the reconstructed 3D dose map is compared along selected profiles and planes with radiochromic film and diode measurements. The comparison indicates that the 3DSD method agrees, within 25% for most points or within approximately 2 mm distance to agreement, with the relative radiochromic film and diode dose distributions in a small (approximately 4.5 mm high and approximately 12 mm diameter) volume in the unobstructed, high gradient dose region outside the edge of the plaque. For a comparison, the reproducibility of the radiochromic film results for our measurements ranges from 10 to 15% within this volume. At present, the 3DSD method is not accurate close to the edge of the plaque, and further than approximately 10 mm (<10% central axis depth dose) from the plaque surface. Improvement strategies, considered important to provide a more accurate quick check of the dose profiles in 3D for brachytherapy applicators, are discussed.     

Terminal deletion 6p23: a case report

We report on a girl with cleft lip and cleft palate, antimongoloid slant of the palpebral fissures, umbilical hernia, skeletal anomalies, partial syndactyly, hypertonia with increased deep tendon reflexes, psychomotor and growth retardation, and other congenital anomalies. Cytogenetic studies demonstrated a 46,XX,del(6)(qter----p23:) chromosome constitution.     

Intracellular lectin-binding sites in symbiont-bearingCrithidia species

Crithidia oncopelti, C. deanei, andC. desouzai are flagellates of the Trypanosomatidae family that present bacterium-like endosymbionts in their cytoplasm. Direct and indirect lectin-gold labeling techniques were used at the electron microscopic level in Lowicryl K4M-embedded cells to demonstrate the presence of intracellular lectin-binding sites. We used the lectinsUlex europaeus I, Griffonia simplicifolia II, Ricinus communis I, Arachis hypogaea, G. simplicifolia I, Wistaria floribunda, Limulus polyphemus, andCanavalia ensiformis, which recognize -l-fucose, - and -N-acetylglucosamine, -galactose and -N-acetylgalactosamine, -galactose, -galactose, -N-acetylgalactosamine, sialic acid and -d-mannose, and -d-glucose residues, respectively. The nucleus was the cellular structure most frequently labeled by the lectins. The Golgi complex was seldom labeled, whereas the endoplasmic reticulum and the flagellar pocket presented a large number of binding sites. Symbionts had their two unit membranes weakly labeled by the different lectins but displayed no labeling of the space between the membranes.     

Effect of dietary supplementation with vitamin E and stocking density on macrophage recruitment and giant cell formation in the teleost fish, Piaractus mesopotamicus

The effect of dietary supplementation with 0, 100 and 450 mg of vitamin E (DL-alpha tocopheryl acetate)/kg of a dry diet on the kinetics of macrophage recruitment and giant cell formation in the pacu, maintained at different stocking densities (5 kg/m(3) and 20 kg/m(3)), was investigated by insertion of round glass coverslips into the subcutaneous connective tissue. After a feeding period of 18 weeks, the coverslips were implanted and later removed for examination at 2, 7 and 15 days post-implantation. Fish fed diets supplemented with 450 mg of vitamin E showed an increase (P<0.05) in the accumulation of macrophages, foreign body giant cells and Langhans type cells. The kinetics of macrophage recruitment and giant cell formation on the glass coverslips appeared to be strongly influenced by vitamin E supplementation, since fish fed a basal diet and held at high stocking densities showed low numbers of adhering cells on the coverslips, and high concentrations of plasma corticosteroids. On the other hand, fish given a diet supplemented with 450 mg of vitamin E did not show a similar difference in plasma cortisol concentrations related to stocking density. The effect of cortisol concentrations on carbohydrate metabolism, analysed by assessment of plasma glycaemia, was not clear. Blood glucose concentrations did not vary substantially with the different treatments examined. These results suggest that vitamin E may contribute to the efficiency of the fish's inflammatory response by increasing macrophage recruitment and giant cell formation in the foreign body granulomatous reaction. Vitamin E appeared to act on the stress response of pacus by preventing a stress-related immunosuppression.     

Calculation of beta-ray dose distributions from ophthalmic applicators and comparison with measurements in a model eye

Dose distributions throughout the eye, from three types of beta-ray ophthalmic applicators, were calculated using the EGS4, ACCEPT 3.0, and other Monte Carlo codes. The applicators were those for which doses were measured in a recent international intercomparison [Med. Phys. 28, 1373 (2001)], planar applicators of 106Ru-106Rh and 90Sr-90Y and a concave 106Ru-106Rh applicator. The main purpose was to compare the results of the various codes with average experimental values. For the planar applicators, calculated and measured doses on the source axis agreed within the experimental errors (<10%) to a depth of 7 mm for 106Ru-106Rh and 5 mm for 90Sr-90Y. At greater distances the measured values are larger than those calculated. For the concave 106Ru-106Rh applicator, there was poor agreement among available calculations and only those calculated by ACCEPT 3.0 agreed with measured values. In the past, attempts have been made to derive such dose distributions simply, by integrating the appropriate point-source dose function over the source. Here, we investigated the accuracy of this procedure for encapsulated sources, by comparing such results with values calculated by Monte Carlo. An attempt was made to allow for the effects of the silver source window but no corrections were made for scattering from the source backing. In these circumstances, at 6 mm depth, the difference in the results of the two calculations was 14%-18% for a planar 106Ru-l06Rh applicator and up to 30% for the concave applicator. It becomes worse at greater depths. These errors are probably caused mainly by differences between the spectrum of beta particles transmitted by the silver window and those transmitted by a thickness of water having the same attenuation properties.     

Adenocarcinomas of the nasal cavity and paranasal sinuses: a clinicopathological and immunohistochemical study of 14 cases

Aims : To evaluate the clinicopathological profile of 14 cases of nasal and paranasal sinusal adenocarcinoma, and to assess the usefulness of immunohistochemistry in the differential diagnosis of primary and metastatic intestinal-type adenocarcinoma.
Methods and results : Fourteen cases of nasal and paranasal adenocarcinoma, treated at IPOFG, Lisbon, between 1976 and 2002, were studied. Clinical records were reviewed and expression of cytokeratin (CK)7 and CK20 and of neuroendocrine markers was evaluated. The male : female ratio was 3 : 1, and the mean age of the patients was 65.3 years. Ten cases occurred in the paranasal sinuses. There was a history of professional exposure to dust in three patients. Twelve cases were high-grade intestinal type adenocarcinomas (ITAC) and two were low-grade. CK7 was present in 2/9 ITAC cases and CK20 in 8/9 ITAC and in cases of mixed and mucinous histology. All high-grade cases showed neuroendocrine differentiation. Seven of the 12 patients with high-grade adenocarcinoma died of the disease, with a mean follow-up of 47.4 months.
Conclusions : Nasal and paranasal adenocarcinoma mostly occurs in men in the 7th decade. ITAC is the most frequent histological type. The pattern of CK7/CK20 was not useful in the distinction between primary and metastatic intestinal adenocarcinoma. However, in the former, neuroendocrine differentiation proved to be a valuable tool in that distinction.     

Patterns of exochorion ornaments on eggs of seven South American species of Lutzomyia sand flies (Diptera: Psychodidae)

The patterns of exochorion ornaments on eggs of seven South American Lutzomyia sand fly species were analyzed by scanning electron microscopy (SEM): Lutzomyia (Lutzomyia) cruzi (Mangabeira 1938), Lutzomyia (Micropygomyia) evandroi (Costa Lima and Antunes 1936), L. (Nyssomyia) intermedia (Lutz and Neiva 1912), L. longipalpis (Lutz and Neiva 1912), L. migonei (Franca 1920), L. (Nyssomyia) neivai (Pinto 1926), and L. renei (Martins, Falcao, and Silva 1957). Different patterns were observed, which showed the distinction between some species. Egg ornaments in L. cruzi and L. longipalpis appear as single, parallel, unconnected ridges, whereas eggs of L. migonei appear as single, parallel, connected ridges. Eggs of L. (Nyssomyia) intermedia and L. (N.) neivai present a new variation of the single, unconnected, parallel ridges pattern: small tubercles are present, distributed between the ridges. Eggs of L. renei present an elliptical pattern, with most structures connected by straight ridges. Eggs of L. (M.) evandroi present a polygonal pattern, with alternate rows of small and large hexagons. Our data emphasize the advantages of the SEM approach in the study of the exochorion patterns of Lutzomyia eggs and in the distinction of the sand fly species.     

Dosimetry characterization of 32P catheter-based vascular brachytherapy source wire

Dosimetry measurements and Monte Carlo simulations for a catheter-based 32P endovascular brachytherapy source wire are described. The measured dose rates were obtained using both radiochromic dye film and an automated plastic scintillator. The investigated source has dimensions of 27 mm in length and 0.24 mm in diameter, and is encapsulated in NiTi. For the radiochromic film measurements, calibrated radiochromic dye film was irradiated at distances between 1 and 5 mm from the source axis in A-150 plastic, and read out with a high-resolution scanning densitometer. The depth-dose curve measured in A-150 is then converted to that in water using correction factors obtained from Monte Carlo calculations. For the scintillator system, direct measurements in water were acquired at distances between 1 and 6 mm from the center of the source, along the perpendicular bisector of the source axis. The scintillator was calibrated in terms of absorbed-dose rate in a reference beta-particle field at multiple depths. The measured dose rates obtained from the film and scintillator measurements were then normalized to the measured source activity, i.e., to convert the measured data to units of cGy/s/mCi. Theoretical dosimetry calculations of the catheter-based 32P wire geometry were also obtained from Monte Carlo simulations using the Electron Gamma Shower code (EGS4), the Monte Carlo N-particle transport code (MCNP4B), and CYLTRAN from the Integrated Tiger Series codes (ITS v.3) and found to be in good agreement. The results of both measurements and calculations are expressed as absorbed-dose rate in water per unit of contained activity (cGy/s/mCi). Comparisons indicate that the measured and calculated dosimetry are in good agreement (<10%) within the relevant treatment distances (1-5 mm). This work fully characterizes the radiation field around a novel 32P beta brachytherapy source in water. The depth-dose curve can be used to calculate the dose to the vessel wall from a 27 mm 32P source wire centered within the vessel lumen.