Modified direct agglutination test for simplified serologic diagnosis of leishmaniasis

Human leishmaniasis is a severe health problem in many countries around the world. Hence, a cheap, reliable, and accurate diagnostic test is required to fight this disease. Perhaps the direct agglutination test (DAT) meets these criteria, but antigen elaboration involves many difficulties. We have developed a new antigen elaboration method, the EasyDAT method, that avoids the problems associated with the DAT. In this study, we compared the traditional DAT antigen method with our EasyDAT antigen method by using canine sera. The sensitivities (100%) and specificities (98.7%) were the same for both methods; we therefore concluded that the EasyDAT Leishmania antigen method simplifies serologic diagnosis, making this method easier and cheaper to use.     

Combined typical carcinoid and acinic cell tumor of the lung: a heretofore unreported occurrence

We report a primary combined typical carcinoid and acinic tumor of the lung in a 70-year-old man. Although a similar case was reported previously, to the best of our knowledge this is the first case in which the diagnosis is supported by both immunohistochemical and ultrastructural findings. We review the literature and discuss the implications of this finding.     

CERR: a computational environment for radiotherapy research

A software environment is described, called the computational environment for radiotherapy research (CERR, pronounced "sir"). CERR partially addresses four broad needs in treatment planning research: (a) it provides a convenient and powerful software environment to develop and prototype treatment planning concepts, (b) it serves as a software integration environment to combine treatment planning software written in multiple languages (MATLAB, FORTRAN, C/C++, JAVA, etc.), together with treatment plan information (computed tomography scans, outlined structures, dose distributions, digital films, etc.), (c) it provides the ability to extract treatment plans from disparate planning systems using the widely available AAPM/RTOG archiving mechanism, and (d) it provides a convenient and powerful tool for sharing and reproducing treatment planning research results. The functional components currently being distributed, including source code, include: (1) an import program which converts the widely available AAPM/RTOG treatment planning format into a MATLAB cell-array data object, facilitating manipulation; (2) viewers which display axial, coronal, and sagittal computed tomography images, structure contours, digital films, and isodose lines or dose colorwash, (3) a suite of contouring tools to edit and/or create anatomical structures, (4) dose-volume and dose-surface histogram calculation and display tools, and (5) various predefined commands. CERR allows the user to retrieve any AAPM/RTOG key word information about the treatment plan archive. The code is relatively self-describing, because it relies on MATLAB structure field name definitions based on the AAPM/RTOG standard. New structure field names can be added dynamically or permanently. New components of arbitrary data type can be stored and accessed without disturbing system operation. CERR has been applied to aid research in dose-volume-outcome modeling, Monte Carlo dose calculation, and treatment planning optimization. In summary, CERR provides a powerful, convenient, and common framework which allows researchers to use common patient data sets, and compare and share research results.     

Bacteria in midguts of field-collected Anopheles albimanus block Plasmodium vivax sporogonic development

Bacterial infections were investigated in midguts of insectary and field-collected Anopheles albimanus Weidemann from southern Mexico. Serratia marcescens, Enterobacter cloacae and Enterobacter amnigenus 2, Enterobacter sp., and Serratia sp. were isolated in field samples obtained in 1998, but only Enterobacter sp. was recovered in field samples of 1997 and no bacteria were isolated from insectary specimens. These bacteria were offered along with Plasmodium vivax infected blood to aseptic insectary An. albimanus, and the number of infected mosquitoes as well as the oocyst densities assessed after 7d. Plasmodium vivax infections in mosquitoes co-infected with En. amnigenus 2, En. cloacae, and S. marcensces were 53, 17, and 210 times, respectively, lower than in control mosquitoes, and the mean oocyst density in mosquitoes co-infected with En. cloacae was 2.5 times lower than in controls. Mortality was 13 times higher in S. marcensces-infected mosquitoes compared with controls. The overall midgut bacterial infection in mosquito field populations may influence P. vivax transmission, and could contribute to explain the annual variations in malaria incidence observed in the area.     

Intracranial pressure and cerebral blood flow velocity in preterm infants with posthaemorrhagic ventricular dilatation

AIM: To determine the volume of cerebrospinal fluid (CSF) that should be tapped in preterm infants with posthaemorrhagic ventricular dilatation as guided by intracranial pressure (ICP) and cerebral blood flow velocity (CBFV). METHODS: The total number of measurements was 106 in 22 infants. Birth weights ranged from 630 to 2050 g, gestational age from 24.5 to 30.3 weeks, and age at insertion from 12 to 67 days. A subcutaneous ventricular catheter reservoir for repetitive CSF drainage was placed when the diameter of a ventricle was > 4 mm above the 97th centile. A volume of 5 ml/kg body weight was removed twice daily. ICP and CBFV were determined before and after CSF tapping. RESULTS: If the ICP after tapping exceeded 7 cm H(2)O, tapping did not result in a significant improvement in CBFV. If the ICP before tapping was less than 6 cm H(2)O, tapping also had no effect on CBFV. Longitudinal studies in individual infants showed a slight correlation between ICP and CBFV. CONCLUSION: Volume of repetitive CSF drainage in preterm infants with posthaemorrhagic ventricular dilatation guided by ICP and CBFV may be a useful technique. An ICP of about 6 cm H(2)O is the cut off point for CSF drainage.     

Effects of chronic hypoxia and protein malnutrition on growth in the developing chick

OBJECTIVE: The purpose of this study was to determine how chronic hypoxia and/or protein malnutrition in ovo affect growth in developing chicks. STUDY DESIGN: Chicken eggs were incubated under normoxic (21% oxygen; n = 30 eggs) or hypoxic (14% oxygen; n = 80 eggs) conditions. Hypoxia was imposed from day 0 (n = 38 eggs), day 10 (n = 22 eggs), or from day 0 to 10 (n = 20 eggs). Protein malnutrition alone (n = 20 eggs) or in combination with hypoxia (n = 24 eggs) was induced by removal of 10% of the estimated total albumin content of the egg. Embryos/chicks were killed and weighed at day 10, 15, or immediately after hatch; organs were removed and weighed. RESULTS: Embryos to which hypoxia was imposed from day 0 weighed less than control embryos at day 10, which stayed the same until hatch (64.67% +/- 3.56% egg mass vs 69.36% +/- 3.90% [mean +/- SD]; P <.05). Malnourished chicks at day 15 and at hatch (63.42% +/- 4.28%; P <.05) weighed less than control chicks, as did malnourished plus hypoxia chicks (59.74% +/- 3.41%; P <.001). Malnourished plus hypoxia chicks weighed less than malnourished chicks alone (P <.05). Embryos that were hypoxic from day 0 to 10 weighed less than control embryos at day 15 (P <.05), but not at hatch. At hatch, neither hypoxia nor malnutrition decreased crown-rump length. Brain and heart weights were increased in both malnourished groups, but not chicks that were hypoxic from day 0. CONCLUSION: Chick embryos exposed to malnutrition show asymmetric growth restriction with relative sparing of the brain and heart. Early growth restriction that was induced by hypoxia from the beginning of incubation is reversed by the restoration of normoxia at mid incubation.     

Texture analysis of optical coherence tomography images: feasibility for tissue classification

Optical coherence tomography (OCT) acquires cross-sectional images of tissue by measuring back-reflected light. Images from in vivo OCT systems typically have a resolution of 10 to 15 mm, and are thus best suited for visualizing structures in the range of tens to hundreds of microns, such as tissue layers or glands. Many normal and abnormal tissues lack visible structures in this size range, so it may appear that OCT is unsuitable for identification of these tissues. However, examination of structure-poor OCT images reveals that they frequently display a characteristic texture that is due to speckle. We evaluated the application of statistical and spectral texture analysis techniques for differentiating tissue types based on the structural and speckle content in OCT images. Excellent correct classification rates were obtained when images had slight visual differences (mouse skin and fat, correct classification rates of 98.5 and 97.3%, respectively), and reasonable rates were obtained with nearly identical-appearing images (normal versus abnormal mouse lung, correct classification rates of 64.0 and 88.6%, respectively). This study shows that texture analysis of OCT images may be capable of differentiating tissue types without reliance on visible structures.