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Biomedical subjects

R M Wilson

Publications and source records attributed to R M Wilson.

At least 73 records · Page 4Linked to original sources
PubMed1985

Insulin dependence: problems with the classification of 100 consecutive patients.

We have evaluated the clinical and immunogenetic features of 100 consecutive patients presenting to an adult diabetic clinic who were judged clinically to need insulin therapy but were not sufficiently ill to be admitted to hospital. Over this same period 15 newly diagnosed patients (aged 13-70 years) were started on insulin as in-patients of whom ten were in ketoacidosis. The 100 out-patients, aged 11-75 years at the time of starting insulin, were followed for at least a year. Fifty-six had islet cell antibodies and/or were heterozygous for HLA DR3 and DR4 (Group A) whereas 44 had neither of these markers (Group B). Islet cell antibodies and/or DR3, DR4 heterozygosity were most common in the 70 patients diagnosed below the age of 40 years but were also found in older patients. Patients in Group A were significantly younger at diagnosis (29 vs. 43 years), had a shorter duration of symptoms (17 vs. 61 weeks), were more likely to have ketonuria, and had a lower random C-peptide level at diagnosis (0.2 vs. 0.31 nmol/l). The two groups could not be distinguished by weight, haemogloblin A1 or blood glucose at diagnosis or by diabetic control or insulin dose after one year. The National Diabetes Data Group (NDDG) definition of insulin dependence stresses the importance of HLA types and islet cell antibodies although we found their prevalence to be low in the 30 patients diagnosed over 40 years who clinically were indistinguishable from the younger patients.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1984

Factors governing the human immune response to injected insulin.

Seventy-nine patients were observed prospectively during their initial period of treatment with conventional bovine insulins. Insulin antibody levels 6 months after starting insulin therapy did not correlate with age, gender or beta cell function at onset of treatment. Patients who required soluble insulin in addition to isophane insulin developed higher levels of insulin antibody. Patients bearing the HLA-B8, DR3 and C4AQO alleles had lower levels of insulin antibody, whereas those bearing DR7 produced significantly higher levels. Other alleles at the C4A, C4B, C2, factor B or Gm loci did not appear to have a significant effect on insulin antibody production. The hyporesponsiveness of B8/DR3/ C4AQO -positive individuals probably reflects a non-specific abnormality of immunity whereas the enhanced responsiveness of those positive for DR7 suggests the presence of a specific immune response gene for insulin.

Adolescent↗
PubMed1983

Hemadsorption and virulence are separable properties of Mycoplasma pneumoniae.

A selective enrichment technique was used to isolate a hemadsorption-positive revertant of a hemadsorption-negative mutant strain of Mycoplasma pneumoniae. This hemadsorption-positive revertant was shown to have simultaneously regained both the ability to attach to neuraminidase-sensitive receptors on the tracheal ring respiratory epithelium in vitro and the ability to synthesize three virulent-strain-specific proteins which were not synthesized by the hemadsorption-negative mutant. Despite the persistence of the revertant in hamster lung tissue for 9 to 12 weeks postinfection, no cytopathology was observed. Intranasal inoculation of the revertant provided limited protection against a challenge dose of virulent M. pneumoniae.

Adhesiveness↗
PubMed1982

Oxygen wash-in method for monitoring functional residual capacity.

Atelectasis, pulmonary edema, fibrosis, pneumothorax, and mucous plug airway obstruction all result in reduced lung volume. The oxygen (O2) wash-in method provides a way to monitor routinely the functional residual capacity (FRC) in the ICU without disconnecting the patient from the ventilator and without additional personnel or instrumentation. This method is a modification of an open-circuit nitrogen (N2) wash-out procedure and requires a computer-based respiratory monitoring system with a fast response O2 analyzer and respiratory flowmeter. FRC is computed after a 20% or greater change in the ventilator FIO2 setting. The accuracy and reproducibility of the method were evaluated using artificial lungs, normal subjects, and postcardiac surgery patients. FRC estimates by O2 wash-in and helium dilution were highly correlated, with r = 0.97 and a regression slope and zero intercept of 1.06 and -0.13, respectively. The FRC difference between 23 repeated trials in 18 postcardiac surgery patients was 70 +/- 160 ml (mean +/- SD).

Cardiac Surgical Procedures↗
PubMed1982

Identification of Mycoplasma pneumoniae proteins associated with hemadsorption and virulence.

Twenty-two mutants of Mycoplasma pneumoniae spontaneously deficient in hemadsorption were isolated. Examination of mutant protein profiles by one- and two-dimensional polyacrylamide gel electrophoresis permitted the grouping of these mutants into four classes. The largest class of mutants was deficient in four high-molecular-weight proteins (215,000, 210,000, 190,000, and 140,000). A second class of mutants lacked three proteins previously designated A, B, and C (72,000, 85,000, and 37,000, respectively). A single mutant, in addition to lacking proteins A, B, and C, was missing a fourth protein of 165,000 molecular weight. The remaining mutants exhibited protein profiles apparently identical to that of the wild-type strain. All mutant strains attached to the respiratory epithelium of hamster tracheal rings in vitro at reduced levels; however, mutants lacking proteins A, B, and C recognized only neuraminidase-insensitive receptors. None of the mutants tested produced detectable pneumonia in intranasally inoculated hamsters, although one mutant class demonstrated low-level survival in vivo.

Adhesiveness↗
PubMed1982

Risk-benefit analysis of warfarin therapy in Hancock mitral valve replacement.

The purpose of this investigation was to analyze the thromboembolic and/or major bleeding complications of 124 consecutive but nonrandomized patients who had only mitral valve replacement with the Hancock porcine xenograft between September, 1974 and June, 1979. These patients were treated either with or without anticoagulants. Four basic study groups were created: Group 1, warfarin; Group 2, aspirin; Group 3, no anticoagulants; and Group 4, warfarin and aspirin. Group 5 combined Groups 1 and 4 (warfarin and warfarin plus aspirin) and Group 6 combined Groups 2 and 3 (aspirin and no anticoagulants). The cardiac rhythm, history of embolism, and intraoperative findings of a thrombus in the left atrium were examined as risk factors for later thromboembolism . Follow-up time was 3.03 years (range 2.0 to 4.2 years). The embolic rate was not significantly different in any group (n = NS). In Groups 5 and 6 the embolic rate was 2.97 and 3.25 embolisms per 100 patient-years, respectively. Warfarin therapy resulted in significant major bleeding episodes, including two deaths (p less than 0.05). The number of patients with a history of a previous embolism, the finding of an intraoperative left atrial thrombus, or abnormal cardiac rhythm was insufficient to test embolic risk in the four treatment groups. We conclude that long-term warfarin therapy increases the risk of bleeding complications but may not significantly influence the incidence of thromboembolism arising from the Hancock porcine xenograft mitral valve. Other and larger studies are needed to confirm this last point.

Adult↗
PubMed1981

Characterization of hemadsorption-negative mutants of Mycoplasma pneumoniae.

Previously isolated mutants of Mycoplasma pneumoniae incapable of hemadsorption were characterized with respect to specific protein content, tracheal ring attachment capability, and virulence for both in vitro and in vivo model systems. Two-dimensional gel electrophoresis revealed both quantitative and qualitative differences between the protein complements of two different mutant strains and that of the virulent parent strain. Studies of mycoplasma attachment to hamster tracheal rings in vitro demonstrated that only one of these mutant strains still possessed the ability to attach to the respiratory epithelium via neuraminidase-sensitive receptors. Measurement of [3H]orotic acid uptake in mycoplasma-infected tracheal rings indicated that infection with the hemadsorption-negative mutants resulted in only slight reductions of ribonucleic acid synthesis, similar to levels observed for tracheal rings infected with an avirulent strain of M. pneumoniae. The virulence potential of the two mutant strains was further investigated by utilizing the hamster model system. Both mutant strains were rapidly cleared from the lungs of infected animals and produced little or no microscopic pneumonia.

Animals↗
PubMed1980

Factors related to a communication style among medical house staff.

This study reports on some factors related to scores on a recently developed pencil-and paper measure of communication style among physicians in training. High scores on this measure (the Facilitating Response Index) indicate a greater preference by the responded to explore or clarify the thoughts or feelings of the patient in a nondirective, open-ended fashion. Higher scores were attained by physicians who had been exposed to interpersonal skills training, who were evaluated by their teachers as being more clinically competent, who planned to enter private practice sometime to the future and whose patients were less likely to fail to show up for follow-up appointments without first calling to cancel.

California↗
PubMed1979

Two-dimensional gel electrophoretic comparison of proteins from virulent and avirulent strains of Mycoplasma pneumoniae.

The protein composition of the virulent M129 strain of Mycoplasma pneumoniae was compared to that of its homologous avirulent strain by the use of standard one-dimensional sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Forty-nine individual M. pneumoniae cell proteins were resolved by this method, and the virulent strain was shown to possess a single high-molecular-weight protein not present in avirulent cells. Variability in the resolution of this particular protein in one-dimensional gels prompted the application of two-dimensional gel electrophoresis to the analysis of M. pneumoniae cell proteins. The sequential use of isoelectric focusing in the first dimension and sodium dodecyl sulfate-polyacrylamide gel electrophoresis in the second dimension permitted the resolution of a least 142 individual M. pneumoniae cell proteins. Application of nonequilibrium pH gradient electrophoresis in the first dimension achieved the resolution of at least 20 additional basic proteins. Three proteins which are synthesized only by cells of the virulent strain, and not by the homologous avirulent strain, were identified by these two-dimensional gel electrophoresis techniques.

Bacterial Proteins↗
PubMed1978

Effects of a protein meal, intraduodenal HCl, and oleic acid on portal and peripheral venous secretin and on pancreatic bicarbonate secretion.

We have studied the effect of a protein meal on secretin (IRS) concentration in dogs and humans using a radioimmunoassay of improved sensitivity (8 pg/ml). After a meal, pancreatic bicarbonate secretion (PBS) increased markedly and proximal duodenal pH decreased from 6.2 to 4.3. Portal and peripheral IRS concentrations, however, remained unchanged in eight dogs and five patients with cirrhosis of the liver. Similarly, an alkaline solution of sodium oleate (pH 9.2) stimulated PBS but not IRS. Intraduodenal administration of various amounts of HCl in dogs demonstrated that acid-stimulated PBS was invariably accompanied by rises in peripheral venous IRS concentration. We conclude that the postprandial stimulation of PBS involves mechanisms more complex than acid-stimulated secretin release.

Adult↗
PubMed1978

Anaphylaxis to alcuronium.

Five cases of severe anaphylactic reactions to alcuronium are described. Investigation suggested that these are probably true anaphylaxis to the drug. The cases illustrate the value of intradermal testing in detecting the drug involved and the necessity of using colloidal solutions and adrenaline in the management of hypotension due to anaphylaxis.

Adolescent↗
PubMed1978

Pancreatic polypeptide responses to a meal and to intraduodenal amino acids and sodium oleate.

Serum concentrations of immunoreactive pancreatic polypeptide (IR-PP) were measured in dogs in response to a meal and to intraduodenal infusions of amino acids, Na oleate, and HCl. In addition, the effects of somatostatin on meal-stimulated IR-PP concentrations were studied. In response to a meal, IR-PP rose from 151 +/- 19 pg/ml to 296 +/- 35 pg/ml (P less than 0.01) at 15 min, reached a plateau of 367 +/- 56 pg/ml at 45 min, and remained elevated for 4 h. In response to intraduodenal amino acids, IR-PP rose from 196 +/- 22 pg/ml to 342 +/- 19 pg/ml (P less than 0.01), and serum alanine rose from 251 +/- 18 mM to 361 +/- 30 mM. Peak concentrations of IR-PP, however, were reached before alanine rose above baseline. During administration of intraduodenal Na oleate, IR-PP rose from 181 +/- 21 pg/ml to 348 +/- 17 pg/ml (P less than 0.01). Intraduodenal HCl had no effect on IR-PP. Intravenous somatostatin (100 microgram/h) suppressed meal-stimulated IR-PP from 450 +/- 68 pg/ml to 133 +/- 23 pg/ml (P less than 0.01). The data indicate 1) IR-PP is increased after a meal and intraduodenal administration of amino acids and Na oleate; 2) the increases in serum IR-PP precede increases in serum levels of absorbed alanine; and 3) somatostatin suppresses the meal-stimulated increase in serum IR-PP.

Amino Acids↗