Search PubMed⌕ Search

Biomedical subjects

J D King

Publications and source records attributed to J D King.

At least 37 records · Page 2Linked to original sources
PubMed1980

Sensitivity to carbenicillin and ticarcillin, and the beta-lactamases of Pseudomonas aeruginosa in the UK in 1978-79.

A total of 438 strains of Pseudomonas aeruginosa supplied by 10 hospitals in the UK reporting an increase in resistance to carbenicillin was tested for sensitivity to carbenicillin and ticarcillin. It was found that 85% of the strains were inhibited by 125 microgram carbenicillin/ml and 87% by 50 microgram ticarcillin/ml, and that ticarcillin was from two- to four-fold more active than carbenicillin against the majority of these strains. Strains with a high level of resistance to carbenicillin (MIC greater than 1000 microgram/ml) possessed constitutive beta-lactamases, and five different types of enzyme were identified. There was good correlation between minimum inhibitory concentrations and the results of disc sensitivity tests in this study, 82% with the 100 microgram carbenicillin disc and 90( with the 75 microgram ticarcillin disc, but results reported in the hospital laboratory tests with the carbenicillin disc were less satisfactory (64% correlation). From a comparison with data reported in 1967 there does not appear to have been a significant increase in the incidence of carbenicillin-resistant strains of Ps aeruginosa in the UK.

Carbenicillin↗
PubMed1979

Poly-beta-Hydroxybutyrate Accumulation as a Measure of Unbalanced Growth of the Estuarine Detrital Microbiota.

The procaryotic endogenous storage material poly-beta-hydroxybutyrate (PHB) can be induced to accumulate in the estuarine detrital microbiota under conditions which suggest unbalanced growth, such as limitation of a critical factor(s) in the presence of carbon and energy sources. Changes in PHB-to-lipid phosphate ratios detected in field samples can be mimicked in the laboratory with common estuarine stresses. Acute anoxia or low pH induces conditions of no growth with depression of both the synthesis and catabolism of PHB without change in the lipid phosphate. Balanced growth induced by nutrients increases the lipid phosphate, depresses PHB synthesis, and stimulates PHB catabolism, resulting in a low ratio of PHB to lipid phosphate. Unbalanced growth induced to a small extent by high salinity or much more readily by dark upland runoff water results in rapid accumulation of PHB and slowing of PHB catabolism with little change in lipid phospate. Unbalanced growth conditions result in high PHB-to-lipid phosphate ratios in the detrital microbiota.

Journal Article↗
PubMed1978

Recovery of Poly-beta-Hydroxybutyrate from Estuarine Microflora.

Poly-beta-hydroxybutyrate (PHB) is a uniquely procaryotic endogenous storage polymer whose metabolism has been shown to reflect environmental perturbations in laboratory monocultures. When hydrolyzed for 45 min in 5% sodium hypochlorite, PHB can be isolated from estuarine detrital microflora in high yield and purified free from non-PHB microbial components. Lyophilization of frozen estuarine samples shortens the exposure time to NaOCl necessary for maximal recovery. Lyophilized samples of hardwood leaves, Vallisneria, and the aerobic upper millimeter of estuarine muds yielded PHB. The efficiency of incorporation of sodium [1-C]acetate into PHB is very high and is stimulated by aeration. PHB was not recovered from the anaerobic portions of sediments unless they were aerated for a short time. Levels of PHB in the detrital microbial community do not correlate with the microbial biomass as measured by the extractible lipid phosphate, suggesting that PHB-like eucaryotic endogenous storage materials may more accurately reflect the metabolic status of the population than its biomass.

Journal Article↗
PubMed1977

Muramic acid as a measure of microbial biomass in estuarine and marine samples.

Muramic acid, a component of the muramyl peptide found only in the cell walls of bacteria and blue-green algae, furnishes a measure of detrital or sedimentary procaryotic biomass. A reproducible assay involving acid hydrolysis, preparative thin-layer chromatographic purification, and colorimetric analysis of lactate released from muramic acid by alkaline hydrolysis is described. Comparison of semitropical estuarine detritus, estuarine muds, and sediments from anaerobic Black Sea cores showed muramic acid levels of 100 to 700 microng/g (dry weight), 34 microng/g, and 1.5 to 14.9 microng/g, respectively. Enzymatic assays of lactate from muramic acid gave results 10- to 20-fold higher. Radioactive pulse-labeling studies showed that [14C]acetate is rapidly incorporated into muramic acid by the detrital microflora. Subsequent loss of 14C, accompanied by nearly constant levels of total muramic acid, indicated active metabolism in procaryotic cell walls.

Acetates↗
PubMed1977

Use of lipid composition and metabolism to examine structure and activity of estuarine detrital microflora.

Earlier studies have shown that the activity of the estuarine detrital microflora measured by various enzyme activities, muramic acid and adenosine 5'-triphosphate (ATP) content, heterotrophic potentials, and respiratory activities correlates with the incorporation of C and P into the microbial lipids. In this study, these lipids were reproducibly fractionated into neutral lipid, glycolipid, and phospholipid classes. Distinct differences between the active microflora of oak leaves, sweet gum leaves, and pine needles were evidenced both in the rate of lipid synthesis and in the proportions of neutral lipids, glycolipids, and phospholipids. Successional changes in the microflora of leaves incubated in a semitropical estuary, previously suggested by ATP-to-muramic acid ratios and scanning electron micrography, were reflected in changes in the proportions of C in major lipid classes when analyzed from the same type of detritus. Short incubation times with C gave lipid compositions rich in phospholipids that are typical for the faster-growing bacterial populations; longer incubation with C gave lipid compositions richer in neutral and glycolipids, more characteristic of slower-growing eukaryotes or morphologically more complex prokaryotes. The metabolism of the lipids of the estuarine detrital microflora was examined by a pulse-chase experiment with C. Glycolipids lost C at a rate equal to the loss of C of the slow component of muramic acid. Individual phospholipids lost C from their backbone glycerol esters at different rates.

Journal Article↗
PubMed1977

Benign hemangiomyoma of the uterus.

A benign cavernous hemangiomyoma of the uterus in a 52-year-old woman is described. The tumor consisted of large venous channels within a stroma composed chiefly of smooth muscle and was confined to the corpus, without involvement of the endometrium or cervix. Considerable thrombosis had occurred within the vascular spaces. Hemangiomas of the uterus are very uncommon and the great majority are benign. A classification of uterine hemangiomas is presented, together with a discussion of their histogenesis and their relation to malformations.

Female↗
PubMed1975

A clinical evaluation of a sodium fluoride dentifrice.

A double-blind study to determine the anticaries efficacy of a neutral pH dentifrice containing sodium fluoride and a high Beta-phase calcium pyrophosphate was conducted among elementary school children in Kansas City, Missouri. A sample of 567 children ages 8-13 were recruited and randomly assigned to test and control groups: the test group received a sodium fluoride high Beta-phase calcium pyrophosphate dentifrice, and the control group received a calcium pyrophosphate dentifrice without the active ingredient. The sodium fluoride dentifrice contained fluoride at the level of 1000 ppm. Caried examinations were conducted at initiation, after 12 months, and again after 24 months at the study's termination. All examinations (clinical and radiographic) were performed by the same investigator. At 12 months the sodium fluoride dentifrice demonstrated a caries reduction of 24.1% (DMFS). At 24 months the reduction demonstrated was 30.1% (DMFS); this reduction is significant at alpha = 0.05.

Adolescent↗
PubMedDate not supplied

Congenital pseudarthrosis of the clavicle: a review of the literature and surgical results of six cases.

This article is a retrospective review of six symptomatic patients who, when treated surgically, all healed with excision of pseudarthrosis, bone grafting, and plating. We discuss congenital pseudarthrosis of the clavicle with emphasis on etiologies, clinical presentation, differential diagnosis, and method of treatment. Our patients' chief complaints were cosmesis, pain, or shoulder deformity.

Adolescent↗
PubMedDate not supplied

Method for the clinical evaluation of enamel polish.

Enamel polish of 600 children was scored. The method used is simple and comprises a visual comparison of the facial surfaces of incisors with a polish standard prepared by selectively polishing extracted teeth. Examiners with little experience can distinguish degrees of enamel polish. A high-polish dentifrice produced significantly greater enamel polish during the 27-month study. A "polish" with flour of pumice at the beginning of the study did not influence this enamel polish.

Adolescent↗
PubMedDate not supplied

Metabolism of a new HIV-1 reverse transcriptase inhibitor, 3-[2-(benzoxazol-2-yl)ethyl]-5-ethyl-6-methylpyridin-2(1H)-one (L-696,229), in rat and liver slices.

L-696,229 is a potent and specific inhibitor of human immunodeficiency virus type 1 (HIV-1) reverse transcriptase and is currently undergoing clinical evaluation. In vivo metabolism in rats was investigated using an intravenous bolus dose of 5 mg/kg [3H]L-696,229. The amount of radioactivity eliminated in bile and urine over a period of 6 hr was 60 and 22%, respectively. Radiochromatographic analysis of the bile and urine showed that L-696,229 was metabolized rapidly and completely to several common metabolites. Sequential oxidation at the alpha-position of the 5-ethyl group to an acetyl moiety, aromatic hydroxylation of the benzoxazole group (position C4', C6', or C7'), and subsequent sulfate conjugation were the major metabolic pathways as determined by the application of enzymatic hydrolysis, FAB-MS, and 1H- and 13C-NMR spectroscopies. The in vitro metabolism of this 2-pyridinone derivative with rat liver slices resulted primarily in hydroxylation at the 6-methyl and 5-ethyl groups. The 6-hydroxymethyl- and 5-alpha-hydroxyethyl analogs were also inhibitors of HIV-1 reverse transcriptase.

Animals↗