RNA electropherotypes of human rotaviruses from North and South America.

Between April 1979 and December 1982, viral agents were found in 231 of 695 children admitted to the Texas Children's Hospital with gastroenteritis. Electron microscopic analysis showed that rotaviruses were the most common viral agents, and a seasonal pattern of rotavirus disease was observed. The migration patterns of the RNA segments of these rotaviruses on electrophoresis in polyacrylamide gels were compared with those of rotaviruses collected from other areas of the United States of America and from Argentina, Colombia and Mexico.

Ultrastructural localization of rotavirus antigens using colloidal gold.

Colloidal gold was used to localize six of the ten known proteins of the simian rotavirus SA11 within infected cells by ultrastructural immunocytochemistry. Monospecific or monoclonal antibodies to selected structural and nonstructural proteins were the primary antisera. The major outer capsid glycoprotein, VP7, was associated with nonenveloped particles, with particles de-enveloped by Triton X-100 and with both nuclear and cytoplasmic inclusions.

Double-blind comparison of bismuth subsalicylate and placebo in the prevention and treatment of enterotoxigenic Escherichia coli-induced diarrhea in volunteers.

Enterotoxigenic Escherichia coli cause most traveler's diarrhea in Third World countries. We tested bismuth subsalicylate as prophylactic therapy and as treatment for enterotoxigenic E. coli-induced diarrhea.

Detection of antigenically distinct rotaviruses from infants.

Antigenically distinct rotaviruses, i.e., viruses morphologically identical to conventional rotaviruses by electron microscopy, yet lacking the common group antigen(s) detected by an enzyme-linked immunosorbent assay, were found in 2 of 51 fecal samples from Bulgarian infants with rotavirus gastroenteritis.

DNA hybridization studies of the association of Pseudomonas maltophilia with inflammatory bowel diseases.

An infectious etiology has been suggested for the inflammatory bowel diseases, Crohn's disease and ulcerative colitis, and an association of cell wall-defective variants of Pseudomonas maltophilia and Pseudomonas-like group Va bacteria with Crohn's disease has been reported by Parent and Mitchell. Seven of the Parent-Mitchell isolates were compared by using DNA hybridization and six were identical and similar, but not identical, to a type strain of P. maltophilia.

Two types of glycoprotein precursors are produced by the simian rotavirus SA11.

The rotavirus genome codes for two glycoproteins: an outer capsid structural glycoprotein (VP7, apparent molecular weight 38,000 (38K)) and a nonstructural glycoprotein (NS28K). The synthesis of these glycoproteins was analyzed in infected cells and in a cell-free system derived from rabbit reticulocyte lysates supplemented with dog pancreatic microsomes. The data showed a 37K product synthesized in the cell-free system is the precursor to the 38K glycoprotein and that the 37K polypeptide contains a cleavable signal sequence (apparent molecular weight 1.

Biochemical mapping of the simian rotavirus SA11 genome.

Biochemical mapping experiments of the simian rotavirus SA11 genome were performed to determine which double-stranded RNA segment coded for each of the viral polypeptides. Viral RNA transcripts were synthesized in vitro by using the endogenous viral RNA polymerase and fractionated by electrophoresis in acid-urea agarose gels. The fractionated transcripts were translated in two cell-free systems: micrococcal nuclease-treated reticulocyte lysates and wheat germ extracts.

Effects of tunicamycin on rotavirus morphogenesis and infectivity.

The functions of the two rotavirus glycoproteins were investigated by using tunicamycin and a variant of SA11 rotavirus having nonglycosylated VP7. Results showed that glycosylation of VP7 is not required for normal viral morphogenesis and infectivity and suggested that the nonstructural glycoprotein is involved in assembly of the outer capsid.

Rotaviruses code for two types of glycoprotein precursors.

Rotaviruses are nonenveloped viruses that code for two glycoproteins: a structural glycoprotein (VP7) and a nonstructural glycoprotein (NS29). The precursor to VP7 (37K) was shown to contain a 1.5K cleavable signal sequence.

Localization of rotavirus antigens in infected cells by ultrastructural immunocytochemistry.

Virus structural antigens were localized within a line of monkey kidney (MA104) cells infected with the simian rotavirus SA11 using electron microscopic immunoperoxidase techniques. When hyperimmune guinea-pig anti-SA11 serum was used, virus particles, membranes of virus-associated endoplasmic reticulum, and viroplasmic inclusions were most heavily labelled. A general cytoplasmic reaction (ribosomes, intracytoplasmic membranes, etc.

The effect of bran on bowel function in constipation.

Bran is widely used to treat a variety of gastrointestinal disorders. With few exceptions, investigative work has focused on the effect of bran in normal subjects. Despite its widespread use, there have been no systematic studies of bran in constipation.

Identification, synthesis, and modifications of simian rotavirus SA11 polypeptides in infected cells.

The synthesis and processing of simian rotavirus SA11 polypeptides was investigated after infection of MA104 cells. [35S]methionine- or 3H-amino acid-labeled cell extracts were analyzed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Viral protein synthesis was maximal 3 to 5 h postinfection, and 12 major viral polypeptides were detected.

Anterior spinal artery syndrome with chronic traumatic aortic aneurysm.

Shortly after severe blunt chest trauma, a young man experienced neurological symptoms suggestive of a spinal cord lesion at the lower thoracic level. The symptoms resolved at first, but then recurred 3 years later and progressed slowly. Neurological workup failed to define the cause until a thoracic aortogram showed an aneurysm in the middle portion of the descending aorta in close proximity to a vessel supplying the anterior spinal artery.

Proteolytic enhancement of rotavirus infectivity: molecular mechanisms.

The polypeptide compositions of single-shelled and double-shelled simian rotavirus particles were modified by exposure to proteolytic enzymes. Specifically, a major outer capsid polypeptide (VP3) having a molecular weight of 88,000 in double-shelled particles was cleaved by trypsin to yield two polypeptides, VP5* and VP8* (molecular weights, 60,000 and 28,000, respectively). The cleavage of VP3 by enzymes that enhanced infectivity (trypsin, elastase, and pancreatin) yielded different products compared to those detected when VP3 was cleaved by chymotrypsin, which did not enhance infectivity.

Identification of rotavirus particle types.

Negative-contrast electron microscopy of purified rotavirus particles reveals two particle types: single-shelled and double-shelled particles. The relationship of these particle types, seen by negative staining, to the enveloped and various types of nonenveloped particles seen in thin sections of virus-infected cells was determined. Thin-section and negative-contrast electron microscopic analyses were performed on cell lysates from simian rotavirus.

Intracranial hemorrhage with amphetamine abuse.

Intracranial hemorrhage (ICH) occurred in a drug abuser soon after self-administration of amphetamine. Other reported cases indicate a consistent clinical picture, sometimes fatal or causing permanent neurologic disability.

In vitro transcription and translation of simian rotavirus SA11 gene products.

Rotavirus gene products were examined, with the simian rotavirus SA11 as a model. The endogenous viral RNA-dependent RNA polymerase associated with single-shelled virus particles or with activated double-shelled particles was used to synthesize viral RNA transcripts. Sedimentation velocity sucrose gradient analysis of the RNA transcripts revealed four peaks at 9S, 12S, 14S, and 18S, whereas agarose gel electrophoresis under partially denaturing conditions revealed eight groups of RNA species ranging in molecular weight from 2 x 10(5) to 1.

Establishment of rotavirus persistent infection in cell culture. Brief report.

Inoculation of the rabbit kidney cell line (RK13) with simian rotavirus SA11 resulted in persistently infected (carrier) cultures. A small percentage of these cells produced infectious virus (> 25 passages) and trypsin treatment enhanced virus production.

Identification of rotaviruses of different origins by the plaque-reduction test.

The plaque assay for the simian rotavirus SA11 was shown to be applicable to the economically important calf and porcine rotaviruses. In addition, neutralization of viral infectivity with specific antiserum before assay (plaque-reduction test) was found to be a useful test to identify the species of origin of rotaviruses.

Ultrastructural study of rotavirus replication in cultured cells.

A systematic ultrastructural analysis of the replication cycle of the simian rotavirus SA11 in permissive MA104 cells was performed under reproducible conditions. At 8 h p.i.