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Biomedical subjects

W H Coleman

Publications and source records attributed to W H Coleman.

16 recordsLinked to original sources
PubMed1993

Inhibition of beta-adrenergic binding by fungal metabolites.

Strains of Aspergillus flavus, Fusarium sp., Rhizopus sp. and Candida albicans all produced inhibitors of beta-adrenergic receptor binding; strains of Saccharomyces sp. and Schizosaccharomyces sp. did not. In tests with glutamic acid as the sole nutrient source, a Fusarium sp. produced four-fold larger amounts of inhibitor than the other fungi. The inhibitor from the Fusarium sp. was further purified by lyophilisation and sequential solvent extraction in chloroform, ethyl acetate and butanol; 60% of the original activity was recovered. The inhibitor had an estimated molecular size of 650 Da, and did not absorb light in the visible or ultraviolet range. When compared with a similar inhibitor from Escherichia coli, the Fusarium sp. inhibitor appeared to be a more potent inhibitor of beta-adrenergic and dopaminergic binding to mammalian cells.

Adrenergic beta-Antagonists↗
PubMed1993

Esophagogastroduodenoscopy by family physicians phase II: a national multisite study of 2,500 procedures.

We have prospectively studied 1,783 upper gastrointestinal tract endoscopy procedures as performed by family physicians from thirteen separate office practices. Phase I of the study previously reported on 717 procedures in which patient management was enhanced, diagnostic yields were high, and biopsies were performed where appropriate. In Phase II, the data totaled 2,500 procedures representing 51.1 years of cumulative practice experience by the entire group. All cases were gathered prospectively and biopsies were confirmed by a pathologist's independent tissue analysis. In this series, family physicians were asked to record all complications, and to specify the exact manner in which performance of the procedure enhanced patient management. There have been biopsies in 1,230 (69% biopsy rate) Phase II cases with biopsy reports available in 1,194 (97% reporting rate) cases. There is pathological confirmation of the family physicians' visual diagnosis in 1,104 of 1,194 (93%) available biopsy reports for a 92% accuracy rate. There have been no complications, and the complication rate for the total series (1/2, 500) is now 0.0004.

Biopsy↗
PubMed1988

Gastroscopy: a primary diagnostic procedure.

EGD, using 1986 models of either the fiberoptic gastroscope or the videoscope, is a safe and accurate procedure that can be performed by any physician trained in the technique of endoscope passage. It may be performed at large medical centers or small rural hospitals, outpatient clinics, or even private offices. Patients themselves have indicated preference for endoscopic evaluation over the double-contrast barium meal after they have experienced both procedures. The short time of procedure, its accuracy, safety, and its relative lack of discomfort to the patient lend it readily to being an initial component in the primary evaluation of symptoms of abdominal distress, gastrointestinal bleeding, dysphagia, esophageal reflux, persistent vomiting, and odynophagia. It is essential in the evaluation of complications of esophageal reflux and the evaluation of abnormal radiological findings in the upper gastrointestinal tract. It should never be overlooked in evaluating the patient with iron deficiency anemia of unknown etiology. Economic pressures have already moved EGD from the surgery wards to endoscopy labs and to the outpatient setting. These same forces will project more physicians into the role of the diagnostic endoscopist and the patient will benefit by decreased medical costs, quicker diagnosis and treatment, and enhanced continuity of care.

Gastroscopes↗
PubMed1982

Inhibitors of animal cell-free protein synthesis from grains.

We described earlier the purification and properties of a protein (tritin) from wheat that enzymatically inhibits translation in cell-free systems from animals but not plants. In this report, we have examined 11 additional grains (Family Gramineae) and three other seeds for the presence of tritin-like proteins. In addition to wheat species, barley, oats, rye, triticale and corn were found to be sources of inhibitor; no inhibitor could be detected in rice, millet, sesame, alfalfa, mung bean or common bean seeds. The inhibitors from barley and rye were purified and found to differ from tritin with respect to heat inactivation, although they are similar to tritin with respect to molecular weight, behavior during purification and specific activity. The inhibitor from corn was purified and found to differ from tritin with respect to heat inactivation and molecular weight, although it is similar to tritin in behavior during purification and specific activity. These inhibitors constitute 2-17% of the total extractable protein in these grains. Thus, wheat, barley, rye and corn can serve as convenient sources of a family of closely related inhibitors of protein synthesis which, when conjugated with lectins, antibodies, or hormones, could prove useful as chimeric toxins.

Animals↗
PubMed1981

Factor requirements for the tritin inactivation of animal cell ribosomes.

Wheat germ contains (tritin) that efficiently inhibits protein synthesis in cell-free extracts from animal cells but not from wheat germ. Tritin has been purified to apparent homogeneity and shown to block enzymatically polypeptide chain elongation. We have extended these studies to examine more closely then mechanism of tritin inactivation of animal cell ribosomes. Here we provide evidence suggesting that ATP and tRNA, previously though to be tritin co-factors, function in the inhibition by altering the conformation of the ribosome to a form susceptible to tritin attack. Tritin treatment does not inhibit the binding of aminoacyl-tRNA to ribosomes, but it does partially reduce the ribosome binding of elongation factor 2. Tritin inhibition appears to affect the core ribosome and not ribosome-associated factors. However, the core ribosome itself is not a suitable substrate for tritin attack; a factor(s) is removed from ribosomes by high salt washing which is required for the tritin-induced inhibition. The ability to be inhibited is restored when ascites cell core ribosomes are supplemented with factors from either ascites cells or wheat germ. In contrast, neither ascites cell factors nor wheat germ factors will promote a significant tritin-induced inhibition of core ribosomes from wheat germ. This indicates that the specificity of tritin inhibition resides primarily at the level of eukaryotic core ribosome.

Adenosine Triphosphate↗
PubMed1977

The Cajuns of Southern Alabama: morphology and serology.

A survey was conducted of 324 members of the Cajun isolate of Southern Alabama. Tradition and appearance suggest that this population of about 3,000 are not entirely White, Black, or Indian but constitute a triracial community somewhat reproductively isolated and inbred. The earliest American settlement in the area, along the banks of the Mobile and Tombigbee Rivers, lay between Spaniards to the South and Indian tribes on the other sides: Creek, Choctaw, and Cherokee. Physical measurements are reported for 71 adults, plus color of skin, eyes, and hair. X-rays were taken of wrist and ankle bones of some 253 children. Red blood samples were typed on adults and children, and haptoglobin, Gm, and Gc types were determined from serum. History and physical examinations were also made. Physical measurements and observations suggest predominantly White ancestry, and D2 analysis confirms this, with least similarity to Indians. Analysis of serological traits implies almost 70% White, almost 30% Black, and very little Indians genes. Few defects of clear genetic etiology were discovered. Growth patterns judged from X-rays appeared normal. All genetic loci testable were in Hardy-Weinberg equilibrium except Gc. While history and some common surnames suggest endogamy in the past, the medical and serological findings, plus some additional surnames, indicate that the isolate has already been largely diluted or dissolved.

Adolescent↗
PubMed1977

Partial purification and some properties of delta1-pyrroline-5-carboxylate reductase from Escherichia coli.

delta1-Pyrroline-5-carboxylate (PCA) reductase [L-proline:NAD(P)+5-oxidoreductase, EC 1.5.1.2] has been purified over 200-fold from Escherichia coli K-12. It has a molecular weight of approximately 320,000. PCA reductase mediates the pyridine nucleotide-linked reduction of PCA to proline but not the reverse reaction (even at high substrate concentrations). The partially purified preparation is free of competing pyridine nucleotide oxidase, PCA dehydrogenase, and proline oxidase activities. The Michaelis constant (Km) values for the substrate, PCA, with reduced nicotinamide adenine dinucleotide phosphate (NADPH) or NADH as cofactor are 0.15 and 0.14 mM, respectively. The Km values determined for NADPH and NADH are 0.03 and 0.23 mM, respectively. Although either NADPH or NADH can function as cofactor, the activity observed with NADPH is severalfold greater. PCA reductase is not repressed by growth in the presence of proline, but it is inhibited by the reaction end products, proline and NADP.

Chloromercuribenzoates↗
PubMed1977

Formation and properties of lactate dehydrogenase inhibitors in NADH.

We describe some characteristics of the mode of formation of inhibitors of lactate dehydrogenase from commercial NADH. Inhibitor formation is time- and concentration-dependent and also varies with the commercial source of NADH. At least two inhibitory components can form in concentrated NADH solutions. One of these can be separated from NADH by chromatography on either diethylaminoethyl-celluose or diethylaminoethyl-Sephadex; the second cannot. The NADH-associated inhibitor appeared to be present in each of the three commercial NADH preparations studied. The 260 nm/340 nm absorbance ratio was of no help in locating this inhibitor during chromatography.

Chromatography, Ion Exchange↗
PubMed1968

Cholera toxins: purification and preliminary characterization of ileal loop reactive type 2 toxin.

Details for the preparation and partial purification of culture supernatant fluids of Vibrio cholerae (V. comma) 569B which retain rabbit ileal loop fluid-accumulating activity are presented. These preparations were fractionated on Sephadex G-200 and on diethylaminoethyl-Sephadex. On the latter, two fractions were obtained by elution with a linear sodium chloride gradient. The fraction designated "fraction I" retains the toxic activity as demonstrated in the rabbit ileal loop model. Chemical and immunological properties of this active fraction are described.

Amino Acids↗
PubMedDate not supplied

Esophagogastroduodenoscopy by family physicians: a national multisite study of 717 procedures.

This is the first multisite report of esophagogastroduodenoscopies (EGDs) performed by family physicians. The first 717 EGDs performed by family physicians from 8 separate office practices provide a practical and safe rationale for selected cognitive and psychomotor aspects of continuing medical education after residency training. Although primarily in private practice, these physicians were affiliated with 6 academic institutions. This group of family physicians received training in short courses. The average amount of hands-on training before independent EGD was 8 supervised cases. Cumulatively, these data represent 227 months (18.9 years) of office practice. All cases were collected sequentially from the beginning of each physician's experience, and 454 cases were collected prospectively. Physicians reported excellent patient tolerance. Diagnostic yields were high, and biopsies were performed where appropriate. Pathologists reviewed biopsy specimens from 213 sites. The family physician endoscopic diagnosis agreed with the tissue diagnosis in 188 cases (88 percent). Physicians believed that EGD enhanced management or changed the diagnosis in more than 89 percent of cases. One bleeding complication requiring overnight hospitalization was noted. This complication rate 0.0014 (1/717) compares favorably with published subspecialty complication rates 0.0013 (1.3/1000). These data confirm the ability of some family physicians to perform EGD and suggest that continuation is safe. Biopsy analysis indicates diagnostic accuracy is high. Further study on the cognitive aspects and the defragmentation of care is needed.

Adolescent↗