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Biomedical subjects

J M Carter

Publications and source records attributed to J M Carter.

At least 73 records · Page 4Linked to original sources
PubMed1993

Fryns syndrome.

We report on a premature female infant with Fryns syndrome who had several less commonly reported anomalies. She had bilateral posterior eventration of the hemidiaphragms instead of the usual diaphragmatic defects with visceral herniation into the chest cavity. She also had a unilateral cleft lip, camptodactyly, duodenal atresia, tracheomalacia, bronchomalacia, and Tetralogy of Fallot.

Abnormalities, Multiple↗
PubMed1993

Platelet volume: laboratory measurement and clinical application.

Modern cell analyzers routinely produce platelet indices, but many clinicians do not utilize them in clinical decision-making. In part this can be attributed to difficulties with their laboratory measurement. The mean platelet volume is dependent on a number of variables, including time of analysis after venepuncture, method of analysis, anticoagulant used and specimen storage temperature. The influence of these laboratory variables is significant and reproducible mean platelet volumes are dependent on standardized laboratory methodology. When pre-analysis factors are controlled, alterations in platelet volume can be demonstrated in a number of disease states and assessment of platelet volume can be useful in the monitoring and diagnosis of patients. An understanding of the pathophysiology of alterations in platelet volume and of the inverse relationship between platelet volume and count is a prerequisite for the successful clinical application of platelet volume measurements.

Anticoagulants↗
PubMed1992

Analysis of Escherichia coli colonization factor antigen I linear B-cell epitopes, as determined by primate responses, following protein sequence verification.

Colonization factor antigen I (CFA/I)-bearing strains of enterotoxigenic Escherichia coli (ETEC) are responsible for a significant percentage of ETEC diarrheal disease worldwide whether the disease presents as infant diarrhea with high mortality or as traveler's diarrhea. CFA/I pili (fimbriae) are virulence determinants that consist of repeating protein subunits (pilin), are found in several ETEC serogroups, and promote attachment to human intestinal mucosa. While CFA/I pili are highly immunogenic, the antigenic determinants of CFA/I have not been defined. We wished to identify the linear B-cell epitopes within the CFA/I molecule as determined by primate response to the immunizing protein. To do this, we (i) resolved the discrepancies in the literature on the complete amino acid sequence of CFA/I by N-terminal and internal protein sequencing of purified and selected proteolytic fragments of CFA/I, (ii) utilized this sequence to synthesize 140 overlapping octapeptides covalently attached to polyethylene pins which represented the entire CFA/I protein, (iii) immunized three rhesus monkeys with multiple intramuscular injections of purified CFA/I subunit in Freund's adjuvant, and (iv) tested serum from each monkey for its ability to recognize the octapeptides in a capture enzyme-linked immunosorbent assay. Eight linear B-cell epitopes were identified; the region containing an epitope at amino acids 11 to 21 was strongly recognized by all three individual rhesus monkeys, while the amino acid stretches 22 to 29, 66 to 74, 93 to 101, and 124 to 136 each contained an epitope that was recognized by two of the three rhesus monkeys. The three other regions containing epitopes were recognized by one of the three individuals. The monkey antiserum to pilus subunits recognized native intact pili by immunogold labeling of CFA/I pili present on whole H10407 cells. Therefore, immunization with pilus subunits induces antibody that clearly recognizes both synthetic linear epitopes and intact pili. We are currently studying the importance of these defined epitope-containing regions as vaccine candidates.

Amino Acid Sequence↗
PubMed1992

The 53kDa polypeptide component of the bovine fibre cell cytoskeleton is derived from the 115kDa beaded filament protein: evidence for a fibre cell specific intermediate filament protein.

The 115kDa protein found enriched in the PMCC (plasma membrane-cytoskeleton complex) fraction of the cortex in bovine lens fibre cells is proteolytically processed to a stable 53kDa product. The 115 kDa protein and the 53kDa polypeptide have been purified by a combination of ion exchange and hydroxyapatite chromatography. Tryptic peptide mapping using reverse phase HPLC and subsequent peptide sequencing confirmed that the 53kDa polypeptide is derived from the 115kDa protein. The 53kDa fragment is also a component of the PMCC as well as being a major component of the urea soluble fraction of lens plasma membranes which have been extracted with buffers containing 1M KC1. The 53kDa polypeptide has escaped identification as a breakdown product of the 115kDa protein because it is not recognised by a commonly used monoclonal antibody, R2D2, specific for the bovine 115kDa protein. This result suggests that proteolysis is important in determining the function(s) of the 115kDa protein, and that part of this function is satisfied by the 53kDa protein core. Both the purified 115kDa protein and the 53kDa polypeptide were unable to form either beaded or intermediate filaments on their own but they were able to form short 10nm rods indicative of an intermediate stage in intermediate filament assembly. Comparison ot the assembly properties of the 53 and 115kDa proteins indicate that there are sequences in the 115kDa protein which inhibit in vitro assembly. This is similar to the situation with neurofilament proteins. We suggest that the 115kDa protein is a lens-specific intermediate filament protein.

Amino Acid Sequence↗
PubMed1992

Radiofrequency gas plasma (glow discharge) disinfection of dental operative instruments, including handpieces.

The radiofrequency-stimulated argon gas plasma (glow discharge) technique, already well-known for surface cleaning and activation of adhesion, was investigated for determination of its separate potential for rapid disinfection of dental operative instruments. Disinfection effectiveness was judged from diminished post-treatment recovery of viable organisms from the instruments agitated in saline. Streptococcus salivarius, Bacillus stearothermophilus, and Escherichia coli were used as primary contaminant organisms, dried from gelatin-thickened laboratory cultures onto the instruments and not subjected to any preliminary cleaning steps. Significant disinfection was obtained, with no sensible temperature increases, in under 10 minutes in laboratory apparatus consuming fewer than 5 Watts of power per cycle. Also, clinically used and deliberately-saliva-contaminated high-speed handpieces were gas-discharge-treated, with their resultant rapid disinfection noted by complete suppression of the viability of any transferred natural contaminant organisms within two minutes. With regard to preservation of instrument quality, it was also shown that this low-temperature gas-discharge method provides the noted substantial disinfection without deterioration of sharp edges. Work now in progress suggests that the method can provide cool, rapid, and complete sterilization when hydrogen peroxide vapors are present in the gas plasma used for treatment of instruments first given the normally recommended thorough pre-cleaning.

Argon↗
PubMed1991

Bonding of plastic teeth to denture base resins.

This study evaluated the bond strengths of some new and traditional resin denture teeth and denture base resins. It included regular monolithic acrylic resin teeth (Bioform), monolithic acrylic resin-IPN teeth (Bioform IPN), and multilithic acrylic resin-composite resin teeth (Vivosit), with relatively new light-activated resin (Triad), conventional heat-cured resin (Lucitone 199), and autopolymerizing resin (Hygenic) denture base materials. The results of four-point flexure testing showed that the traditional materials gave the highest bond strength values. The autopolymerizing resin systems demonstrated interfacial failure with all resin denture teeth, showing that the common practice of treating teeth with the respective autopolymerizing monomer failed to produce adequate bond strength. Combinations of acrylic resin, IPN, and multilithic denture teeth with light-activated resins gave results calling for improvements in basic bonding system design, since interface debonding was prevalent. No failures occurred between the lap-ridge region of the multilithic tooth system and conventional heat-cured denture base resin.

Acrylic Resins↗
PubMed1991

Effect of ethanol perfusion on creatinine removal in a Roux-Y intestinal segment.

Five rats and 2 goats had a bypass operation to allow infusion of sorbents through an inlet ostomy. The sorbents passed through one limb of intestine isolated from food contact to join a food limb which included 30-40% of the original length of small intestine. In goats, serum creatinine levels were elevated by infusion of sterile creatinine solutions intravenously. Twenty-four hour urines were collected before, during and after periods of infusion of sorbents into the inlet ostomy. Infusion of charcoal into the ostomy had little effect on the total daily urinary creatinine excretion (TDUC). However infusion of 4.3 g/kg/day ethanol decreased the TDUC significantly, in both species. In rats, 8.6 g/kg/day ethanol infusion had an even greater effect on TDUC. Studies of intraluminal creatinine concentration in the distal part of the sorbent segment indicated that especially when serum concentration of creatinine is over 2 mg%, ethanol greatly increases the intraluminal creatinine concentration in the intestine. It is concluded that ethanol, in combination with intestinal sorbents or alone, could allow intestinal dialysis to remove considerably more creatinine, and possibly aid transport of other organic substances.

Anastomosis, Roux-en-Y↗
PubMed1991

Platelet indices: intra-individual variation in pre- and post-menopausal females.

Blood platelet counts and mean platelet volumes were determined at weekly intervals for eight weeks in 13 pre-menopausal and 11 post-menopausal females. Samples were analysed exactly two hours after blood collection on a Coulter S plus VTM particle counter. Pre-menopausal platelet counts were slightly higher than post-menopausal counts at each week, but the count was not affected by the menstrual cycle, intra-individual variation showing mean coefficients of variation (CV) of 7.4% and 5.2% respectively. The mean platelet volume was similar in pre- and post-menopausal groups at each week and showed little variability over time (mean CV 2.7% and 3.3%, respectively). Platelet parameters show little variability over time in either group and with no cyclical effects of menstruation apparent.

Blood Platelets↗