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Biomedical subjects

J C Ward

Publications and source records attributed to J C Ward.

At least 37 records · Page 2Linked to original sources
PubMed1982

Hyperpipecolic acidemia. Occurrence in an infant with clinical findings of the cerebrohepatorenal (Zellweger) syndrome.

An infant with clinical presentation of the cerebrohepatorenal syndrome (CHRS) of Zellweger was found to have increased plasma and urinary concentrations of pipecolic acid. When given a loading dose of DL-pipecolic acid hydrochloride, she showed a reduced clearance rate for that acid. Piperidine, delta 6-piperidine-2-carboxylic acid, and alpha-aminoadipic acid were not detected in plasma or urine. Her response to a lysine load was comparable to that of controls. These data provide further evidence of the connection between hyperpipecolic acidemia and CHRS.

2-Aminoadipic Acid↗
PubMed1982

An assessment of three portable peak flow meters.

Peak flow has become widely used as in independent measure of lung function, particularly in asthma, because it can be quickly and easily determined by simple portable instrumentation. Three relatively inexpensive devices, the Armstrong mini-Wright peak flow meter, Vitalograph pulmonary monitor, and HealthScan peak flow meter, were tested for accuracy and reproducibility. Five units of each type were individually connected in series to a pneumotachograph, and 20 measurements (five in each of four flow ranges) were made on each unit at pulsatile flows ranging from 120 to 480 Lpm. The mean percentage of discrepancy (D%) for each instrument of a particular model was calculated at each flow range, and these subsequently averaged to give an inter-instrument percentage of discrepancy at each flow for each model. Intra-instrument variability was also assessed as the mean percentage of discrepancy for all flow rates for each individual instrument. While only the Armstrong mini-wright peak flow meter meets flow range criteria established by the American Thoracic Society and American College of Chest Physicians for flow devices, only the HealthScan-Organon peak flow meter meets the established criteria for accuracy and reproducibility.

Peak Expiratory Flow Rate↗
PubMed1981

Microbiology of wetwood: importance of pectin degradation and clostridium species in living trees.

Wetwood samples from standing trees of eastern cottonwood (Populus deltoides), black poplar (Populus nigra), and American elm (Ulmus americana) contained high numbers of aerobic and anaerobic pectin-degrading bacteria (10 to 10 cells per g of wood). High activity of polygalacturonate lyase (</=0.5 U/ml) was also detected in the fetid liquid that spurted from wetwood zones in the lower trunk when the trees were bored. A prevalent pectin-degrading obligately anaerobic bacterium isolated from these wetwoods was identified as Clostridium butyricum. Pectin decomposition by C. butyricum strain 4P1 was associated with an inducible polygalacturonate lyase and pectin methylesterase, the same types of pectinolytic activity expressed in the wetwood of these trees. The pH optimum of the extracellular polygalacturonate lyase was alkaline (near pH 8.5). In vitro tests with sapwood samples from a conifer (Douglas fir, Pseudotsuga menziesii) showed that tori in membranes of bordered pits are degraded by pure cultures of strain 4P1, polygalacturonate lyase enzyme preparations of strain 4P1, and mixed methanogenic cultures from the tree samples of wetwood. These results provide evidence that pectin in xylem tissue is actively degraded by C. butyricum strain 4P1 via polygalacturonate lyase activity. The importance of pectin degradation by bacteria, including Clostridium species, appears paramount in the formation and maintenance of the wetwood syndrome in certain living trees.

Journal Article↗
PubMed1976

An evaluation of the usefulness of amylase isozyme differentiation in patients with hyperamylasemia.

Amylase assays measure total activity without differentiating the relative contributions of pancreatic- and salivary-type amylase isozymes. Since polyacrylamide electrophoresis allows identification of salivary-and pancreatic-type isoxymes and their respective variants, serum and urine specimens from patients with the clinical diagnoses of mumps (4), pancreatitis (16), or undiagnosed hyperamylasemias (5) were compared with specimens from control subjects. Patients with mumps had elevations of salivary-type isozymes, while those with pancreatitis had elevations of pancreatic-type isozymes. Elevation of salivary-type isozymes was identified in the five patients who had undiagnosed hyperamylasemias; among these, the isozymes of two originated in neoplastic ovarian tissue and those of three, probably in the salivary glands. Amylase isozyme differentiation cannot unamibiguously identify the tissue source of hyperamylasemia. However, in patients whose hyperamylasemia is of unknown etiology or who respond atypically to therapy, amylase electrophoresis provides identification of the elevated isozyme type, thus providing the basis for the rational selection of further diagnostic procedures.

Aged↗