Serial observations of chronic rotavirus infection in an immunodeficient child.

Chronic rotavirus infection of an infant with severe combined immunodeficiency (SCID) was studied by virological examinations in association with long-term observation of his symptoms and immune status. During eleven months of hospitalization, the patient was suffering from incurable severe diarrhea with persisting excretion of rotaviruses detected by electron microscopy and the reversed-passive hemagglutination (R-PHA) test and had transient hepatitis symptom despite multiple administrations of human gammaglobulin and high calorie fluids. The detected viruses were morphologically recognized as rotavirus with double capsid structure. Polyacrylamide gel electrophoretic (PAGE) analysis of their genomic RNAs showed the long electropherotype of group A virus with abnormal migration profiles changing considerably from the early to the late phase of illness: (1) The 11th segment became undetectable; (2) the molecular weight of the 6th segment slightly increased; (3) seven to fourteen extra segments appeared; and (4) PAGE patterns of viral genomic RNAs changed every three or four months. These findings suggest that chronic infection with rotavirus accompanied the generation of extra viral genomic segments and their unusual assortments in an immunodeficient host.     

A Tanganyikan cichlid <Emphasis Type="Italic">Neolamprologus mustax</Emphasis> selectively exploits territories of another cichlid <Emphasis Type="Italic">Variabilichromis moorii</Emphasis> due to its inter-individual variation in aggression

Wetland restoration in highly modified landscapes involves balancing target ecosystem functions and values with constraints of landscape and stakeholder context. Often, a restored wetland complex cannot meet all target conditions simultaneously, and tradeoffs must be understood, evaluated, and quantified. We examined the tradeoff between providing migratory bird sanctuary and increasing public recreational opportunities within a restored floodplain wetland complex along the Illinois River. We surveyed the distribution and behavior of waterbirds in response to a gradient of spatial and temporal disturbances from waterbird hunting activities. Using ArcMap and spatial interpolation of waterbird densities as a novel approach to quantify sanctuary area, we estimated that approximately 42% of Emiquon Preserve functioned as sanctuary across disturbance intensities, hunter distribution, and time periods during autumn migration. Waterbird abundance did not increase with short-term temporal sanctuary or decreased hunting intensity. Disturbance distance around hunting locations was 752.1 m, overall, and increased 38.4 m for each additional hunting party. Exclusion distance around hunting locations was greater in areas with greater mean disturbance frequency. We question the effectiveness of short-term temporal sanctuary for waterbirds at the expense of recreational opportunities and advocate our analytical approach to quantify sanctuary area and disturbance buffers without experimentally causing disturbances.     

Functional expression of nitrogenase-like protochlorophyllide reductase from Rhodobacter capsulatus in Escherichia coli

Dark-operative protochlorophyllide oxidoreductase (DPOR) is a nitrogenase-like enzyme catalyzing D-ring reduction of protochlorophyllide in chlorophyll and bacteriochlorophyll biosynthesis. DPOR consists of two components, L-protein and NB-protein, which are structurally related to nitrogenase Fe-protein and MoFe-protein, respectively. Neither Fe-protein nor MoFe-protein is expressed as an active form in Escherichia coli due to the requirement of many Nif proteins for the assembly of the metallocenter and the maturation specific for diazotrophs. Here we report the functional expression of DPOR components from Rhodobacter capsulatus in Escherichia coli. Two overexpression plasmids for L-protein and NB-protein were constructed. L-protein and NB-protein purified from E. coli showed spectroscopic properties similar to those purified from R. capsulatus. L-protein and NB-protein activities were evaluated using a crude extract of E. coli overexpressing NB-protein and L-protein, respectively. Specific activities of the purified L-protein and NB-protein were 219+/-38 and 52.8+/-5.5 nmolChlorophyllide min(-1) mg(-1), respectively, which were even higher than those of L-protein and NB-protein purified from R. capsulatus. These E. coli strains provide a promising system for structural and kinetic analyses of the nitrogenase-like enzymes.     

Data Deposition and Annotation at the Worldwide Protein Data Bank

The Protein Data Bank (PDB) is the repository for three-dimensional structures of biological macromolecules, determined by experimental methods. The data in the archive is free and easily available via the Internet from any of the worldwide centers managing this global archive. These data are used by scientists, researchers, bioinformatics specialists, educators, students, and general audiences to understand biological phenomenon at a molecular level. Analysis of this structural data also inspires and facilitates new discoveries in science. This chapter describes the tools and methods currently used for deposition, processing, and release of data in the PDB. References to future enhancements are also included. Shuchismita Dutta, Kyle Burkhardt, and Ganesh J. Swaminathan have contributed equally to this work.     

Effects of neonicotinoid seed treatments on wild bee populations in soybean and corn fields in eastern Ontario

1. Neonicotinoid-coated corn and soybean seeds are a common crop in Canada and the US. A growing body of research is demonstrating that, through various exposure routes, neonicotinoids can impact a suite of nontarget organisms including beneficial insects such as bees. However, to date, only a few studies have examined the effects of neonicotinoids in field settings.
2. We assessed the relationship between agricultural crop soil neonicotinoid levels and wild bee abundance and diversity at 16 agricultural sites representing different soil neonicotinoid levels. We detected clothianidin at 11 sites, thiamethoxam at three sites; imidacloprid was not detected.
3. Hedgerow and crop soils were consistent in terms of where clothianidin was detected; thiamethoxan was not detected in hedgerow soils. Based on model outcomes, fields with higher levels of soil neonicotinoids exhibited significantly lower wild bee abundance and diversity than those with low or no neonicotinoids detected.
4. Crop soil neonicotinoid level, hedgerow floral resource abundance and crop type were consistent predictors of bee abundance across models; only neonicotinoid level and crop type were significant predictors of diversity.
5. Our results are consistent with recent findings in the midwestern US, and underscore the potential risk of soil neonicotinoids to wild bee populations across regions and crop systems.

     

Hepatic stellate cells (vitamin A-storing cells) change their cytoskeleton structure by extracellular matrix components through a signal transduction system

 When cultured on a polystyrene surface or aminoalkylsilane-coated cover glasses, rat and human hepatic stellate cells exhibit a flattened, fibroblast-like shape with well-developed stress fibers. However, culturing the cells on type I collagen gel results in the elongation of long, multipolar cellular processes, whereas cells cultured on Matrigel maintain their round shapes. Dual fluorescence staining of microtubules and fibrillar actin indicated that the processes extend together with collagen fibers and contained microtubules as the core, whereas the periphery contained fibrillar actin. Immunofluorescence staining of vinculin showed that the focal adhesions were distributed mainly in lamellipodia when cultured on aminoalkylsilane-coated cover glasses, whereas in the cells cultured on type I collagen gel they were localized to the tips of the processes and along their bottom surface contacting collagen fibers. Wortmannin, as well as staurosporin and herbimycin A, inhibited the elongation process and induced the retraction of elongated processes. The wortmannin treatment also resulted in an alteration in focal adhesion distribution from the processes to cell bodies. These results indicate that the cell surface integrin binding to interstitial collagen fibers induces the elongation of processes through signaling events and the subsequent cytoskeleton assembly in hepatic stellate cells. Accepted: 12 February 1998     

Pattern of shedding of small, round-structured virus particles in stools of patients of outbreaks of food-poisoning from raw oysters

The pattern of shedding of the small, round-structured virus (SRSV) particles in the stools of patients who suffered from food-poisoning due to raw oysters was investigated. The duration and concentration of fecal shedding of the SRSV particles were studied by electron microscopic examinations of stool specimens obtained during the course of illness to see a relation of viral shedding to day of illness. It was found that the fecal shedding of the SRSV particles occurred within five days of illness; thereafter, the concentration of the SRSV particles in feces rapidly decreased within a few days during the course of illness.