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R K Williams

Publications and source records attributed to R K Williams.

35 records · Page 2Linked to original sources
PubMed1990

MHV-resistant SJL/J mice express a non-functional homolog to the MHV receptor glycoprotein.

MHV-A59 recognizes a 100-110 K glycoprotein receptor on intestinal and liver plasma membranes. The receptor protein was affinity purified using an anti-receptor monoclonal antibody. Purified receptor was sequenced from the 1st to the 15th amino acids. Antiserum raised against a synthetic peptide having this sequence bound to the 110 K receptor from BALB/c intestine and a 58 K fragment of the receptor. SJL/J mice are resistant to MHV-A59 and their plasma membranes were previously shown to lack binding to MHV. However, anti-peptide antibody bound to a 105 K protein and a 53 K protein fragment from SJL/J plasma membranes. These SJL/J proteins did not bind MHV or to the blocking monoclonal anti-receptor antibody. Genetic resistance of SJL/J mice to MHV-A59 appears to be due to mutation of the receptor glycoprotein resulting in a molecule that does not bind MHV.

Animals↗
PubMed1990

Purification of the 110-kilodalton glycoprotein receptor for mouse hepatitis virus (MHV)-A59 from mouse liver and identification of a nonfunctional, homologous protein in MHV-resistant SJL/J mice.

The receptor for mouse hepatitis virus strain A59 (MHV-A59) is a 110- to 120-kilodalton (kDa) glycoprotein which is expressed in MHV-susceptible mouse strains on the membranes of hepatocytes, intestinal epithelial cells, and macrophages. SJL/J mice, which are highly resistant to MHV-A59, were previously shown to lack detectable levels of receptor by using either solid-phase virus receptor assays or binding of a monoclonal anti-receptor antibody (MAb) which blocks infection of MHV-susceptible mouse cells. This MAb was used for affinity purification of the receptor glycoprotein from livers of MHV-susceptible Swiss Webster mice. The MHV receptor and an antigenically related protein of 48 to 58 kDa were copurified and then separated by preparative sodium dodecyl sulfate-polyacrylamide gel electrophoresis. The first 15 amino acids of the receptor were sequenced, and a synthetic peptide of this amino acid sequence was prepared. Rabbit antiserum made against this peptide bound to the MHV receptor glycoprotein and the 48- to 58-kDa protein from livers of MHV-susceptible BALB/c mice and Swiss Webster mice and from the intestinal brush border of BALB/c mice. In immunoblots of intestinal brush border and hepatocyte membranes of MHV-resistant SJL/J mice, the antibody against the amino terminus of the receptor identified proteins that are 5 to 10 kDa smaller than the MHV receptor and the 48- to 58-kDa related protein from Swiss Webster or BALB/c mice. Thus, SJL/J mice express a protein which shares some sequence homology with the MHV receptor but which lacks virus-binding activity and is not recognized by the blocking anti-receptor MAb. These results suggest that resistance of SJL/J mice to MHV-A59 may be due to absence or mutation of the virus-binding domain in the nonfunctional receptor homolog in SJL/J mice.

Amino Acid Sequence↗
PubMed1988

Successful treatment of ciguatera fish poisoning with intravenous mannitol.

Twenty-four patients with acute ciguatera fish poisoning were treated with intravenous mannitol, and each patient's condition improved dramatically. All exhibited marked lessening of neurologic and muscular dysfunction within minutes of the administration of mannitol. Gastrointestinal symptoms disappeared more slowly. Two patients in coma and one in shock responded within minutes, with full recovery after infusion. Although these observations were empiric and uncontrolled and the mechanism of action of mannitol in this disease is unclear, mannitol should be considered for initial use in patients with significant illness and morbidity from ciguatera fish poisoning.

Adolescent↗
PubMed1985

Cell-surface antigens of developing rat cerebellar neurons: identification with monoclonal antibodies.

Three monoclonal antibodies (Mab's), named 3C5.59, 3G5.34, and 3G6.41, that recognize cell-surface antigens found on embryonic and postnatal neurons were selected for study from among a group generated against adult rat synaptic plasma membranes (SPM's). Immunofluorescence staining with these 3 antibodies showed strong reactivity of the processes and much weaker staining of the cell bodies of the small neurons cultured from early postnatal rat cerebella. Mab 3G6.41 also reacted with flat astrocyte-like cells cultured from cerebellum. In contrast Mab's 3C5.59 and 3G5.34 appeared to specifically recognize only the neurons in these cultures. In situ staining of cryostat sections with 3G5.34 and 3G6.41 demonstrated immunoreactivity that was predominantly localized to the molecular layer of the cerebellum in the early postnatal through adult stages, in agreement with the strong staining of neurites seen in primary neuronal cultures. Quantitative analysis of Mab binding to particulate protein preparations from various tissues of the adult rat indicated that each of the antigens is restricted to the nervous system in the adult. Binding studies also indicated that each antigen was enriched approximately 1.5-fold in the SPM fractions compared to total particulate fractions from cerebellum. All 3 Mab's recognize membrane-bound molecules that can be solubilized by non-ionic detergent. Mab 3G6.41 immunoprecipitated two polypeptides of 140,000 and 185,000 apparent molecular weight from detergent-solubilized cerebellar cells that were surface-iodinated in culture. These antibodies should prove useful in the further analysis of the expression and function of individual cell surface antigens during the differentiation of cerebellar granule cells.

Animals↗
PubMed1985

Individual neural cell types express immunologically distinct N-CAM forms.

The neural cell adhesion molecules, or N-CAMs, are a group of structurally and immunologically related glycoproteins found in vertebrate neural tissues. Adult brain N-CAMs have apparent molecular weights of 180,000, 140,000, and 120,000. In this article we identify, using monoclonal antibody (Mab) 3G6.41, an immunologically distinct adult rat N-CAM form and show that this form is selectively expressed by some clonal neural cell lines. Consecutive immunoprecipitation experiments indicate that rabbit anti-N-CAM can remove from solubilized cerebellar neuron primary cultures all 180,000- and 140,000-mol-wt N-CAM molecules that react with Mab 3G6.41. However Mab 3G6.41 cannot remove all N-CAM molecules that react with rabbit anti-N-CAM. Rabbit anti-N-CAM binds to and immunoprecipitates N-CAM forms from the rat neuronal cell lines B35, B65, and B104, the glial lines B12 and C6, and L6 myoblasts. Mab 3G6.41 does not bind to or immunoprecipitate N-CAM from the B12 and B65 lines but does react with the other four lines by both criteria. Many cells in primary cultures of postnatal rat that express glial fibrillary acidic protein also bind Mab 3G6.41. Thus a unique form of rat N-CAM recognized by Mab 3G6.41 is found on some but not all neuronal, glial, and muscle cells.

Animals↗
PubMed1985

Epidemiology of diarrhoea caused by enterotoxigenic Clostridium perfringens.

Enterotoxigenic strains of Clostridium perfringens have recently been implicated in some cases of antibiotic-associated diarrhoea. We present here the results of an epidemiological study of this disease. Five cases of diarrhoea caused by C. perfringens serotype 41 occurred during a 9-week period, and then during a 6-week period there were three cases due to serotype 27 and two due to serotype 24; in all but one case two geriatric wards were involved. In total there were 16 cases in 22 months. All cases were identified by the detection of C. perfringens enterotoxin in the faeces. The mean number of C. perfringens in these cases was 10(8.8) cfu/g of faeces. Of 37 patients who had negative test results for C. perfringens enterotoxin, 18 had positive cultures for C. perfringens, with mean faecal counts of 10(5.3) cfu/g, and nine of these patients had diarrhoea. Thirteen different serotypes were isolated from these 18 patients, including type 41 from seven patients and type 27 from one. Hand carriage of the offending serotype was demonstrated in three of four infected patients, none of four controls and two of 14 ward staff. C. perfringens of serotypes causing disease was isolated from 59% of environmental areas where there was active disease, 27% of areas where there had been disease which had since resolved and 9% of areas where there was no history of disease. The findings imply that cross infection may occur.

Aged↗
PubMed1984

Postcoronary pain and the postmyocardial infarction syndrome.

Since non-specific chest pain, which is a common feature after myocardial infarction, may be due to a mild form of Dressler's (postmyocardial infarction) syndrome 80 patients were studied after confirmed myocardial infarction. Two patients had clinical features of classical Dressler's syndrome with high erythrocyte sedimentation rates and strongly positive results for antimyocardial antibodies. Twenty three patients had non-specific chest pain; none had clinical features of Dressler's syndrome. There was no difference in the erythrocyte sedimentation rate between this group and the remainder who had no pain. Equal numbers in each group had weakly positive test results for antimyocardial antibodies; none had a strongly positive result. Thus there appears to be no evidence for a mild form of Dressler's syndrome, and the erythrocyte sedimentation rate and weakly positive results for antimyocardial antibodies are of no diagnostic value in Dressler's syndrome.

Antibodies↗
PubMed1982

Acute and chronic hepatic involvement of brucellosis.

Two patients with brucellosis are presented; one with acute hepatitis and the other with a chronic draining sinus at the right costal margin which originated from an abscess of the liver. Brucella abortus infection may be manifest by nonspecific hepatic inflammation or, occasionally, by granulomatous hepatitis. Rarely, cirrhosis may result if untreated. Chronic hepatic and splenic involvement, which is characterized by tissue calcification, can be seen in Brucella suis infection. Suppurative complications may develop after many years of dormancy. This variable response to Brucella infection seems related to species differences and perhaps differing immune response in the host. Because Brucella suis has been more commonly recovered in recent years, more patients with chronic hepatic and splenic involvement may be seen in the future.

Adult↗
PubMed1978

Pressure-induced changes in the nuclear magnetic resonance spectra of a biopolymer in aqueous solution.

High resolution proton nuclear magnetic resonance spectra of the poly(amino acid)poly[N5-(3-hydroxypropyl)-L-glutamine], of degrees of polymerization 685 and 137, were measured in a mixed D2O and H2O solvent, at pressures from 1.03 to 1968.5 kg/cm2, and at temperatures of 2 and 10 degrees C. Increasing the pressure appeared to cause an increased mobility of the side chain hydrocarbon residues, and also of the alpha-hydrocarbon residue of the polymer chain. This is interpreted to imply the occurrence of a volume decrease on unfolding of the polymer from a helix to a random coli, with subsequent exposure of hydrophobic groups to the solvent.

Glutamine↗