Biomedical subjects

W M Hill

Publications and source records attributed to W M Hill.

5 recordsLinked to original sources

PubMed1996

Are echoviruses still orphans?

A review of some of the outbreaks of disease caused by echoviruses demonstrates their ability to cause significant morbidity and mortality world-wide. There are now 30 recognised echovirus serotypes; several of the original serotypes have been re-classified. More recently, echovirus 22 has been shown to have significant molecular differences from other types and unusual epidemiological features. Echovirus types 7, 11, 19 and 30 have been associated with significant outbreaks in neonatal units and echovirus types 9, 16 and 25 are more frequently associated with exanthem. Echovirus type 3, although relatively uncommon in the UK, was associated with large outbreaks in China. Since the decline in poliomyelitis, the increase in reports of non-polio enteroviruses has revealed a corresponding increase in associated cases of myalgic encephalomyelitis and post-viral fatigue syndrome.

Disease Outbreaks↗

PubMed1995

Routine detection of Trichomonas vaginalis in genital specimens using culture in microtitre trays.

The culture of genital specimens for the detection of Trichomonas vaginalis is generally regarded as the most sensitive technique available for routine use. However, the technique is relatively expensive and time-consuming, involving the preparation of one or more wet mounts from the culture to observe motile trichomonads. Considerable savings in cost and time can be achieved by using culture in microtitre trays and visualisation with an inverted microscope.

Animals↗

PubMed1980

Thermal injury of Yersinia enterocolitica.

Procedures were developed to evaluate thermal injury to three strains of Yersinia enterocolitica (serotypes 0:3, 0:8, and 0:17). Serotype 0:17 (atypical strain) was more sensitive to bile salts no. 3 (BS) and to sublethal heat treatment than the typical strains, 0:3 and 0:8. When the 0:3, 0:8, and 0:17 serotypes were thermally stressed in 0.1 M PO4 buffer, pH 7.0, at 47 degrees C for 70, 60, and 12 min, respectively, greater than 99% of the total viable cell population was injured. Injury was determined by the ability of cells to form colonies on brain heart infusion (BHI) agar, but not on Trypticase soy agar (TSA) plus 0.6% BS for serotypes 0:3 and 0:8 and TSA plus 0.16% BS for 0:17. Heat injury of serotype 0:17 cells for 15 min in 0.1 M PO4 buffer caused an approximate 1,000-fold reduction in cell numbers on selective media as compared with cells heated in pork infusion (PI), BHI broth, and 10% nonfat dry milk (NFDM). The extended lag and resuscitation period in BHI broth was 2.5 times greater for 0:17 cells injured in 0.1 M PO4 than for cells injured in BHI or PI. The rate and extent of repair of Y. enterocolitica 0:17 cells in three recovery media were directly related to the heating menstruum used for injury. The use of metabolic inhibitors demonstrated that ribonucleic acid synthesis was required for repair, whereas deoxyribonucleic, cell wall, and protein synthesis were not necessary for recovery of 0:17 cells injured in 0.1 M PO4 buffer, BHI, or PI. Inhibition of respiration by 2,4-dinitrophenol slowed repair only for 0:17 cells injured in 0.1 M PO4 buffer, not for cells injured in PI or BHI.

Bacterial Proteins↗

PubMed1977

Effects of varying concentrations of novobiocin incorporated into two salmonella plating media on the recovery of four enterobacteriaceae.

Hydrogen sulfide-producing strains of salmonellae, Escherichia coli, Citrobacter freundii, and Proteus mirabilis were isolated from fresh pork sausage. All the strains produced black-centered colonies on Hektoen enteric agar (HE). On xylose lysine deoxycholate agar (XLD), C. freundii produced yellow colonies, and the strains of the other three genera formed black-centered colonies. The selectivity of HE and XLD for salmonellae was improved by the addition of novobiocin to both media. With increasing concentrations of novobiocin, the degree of growth inhibition for the four genera was less on HE than on XLD. Novobiocin concentrations of 80 mug/ml in HE and 5 mug/ml in XLD did not affect the growth or colonial morphology of salmonellae. When 80 mug of novobiocin per ml was incorporated into HE, P. mirabilis strains were not recovered, 40% of C. freundii strains failed to form black-centered colonies, and growth of E. coli strains was not affected but colonies were altered without eliminating the black centers. When novobiocin at 5 mug/ml was incorporated into XLD, colonies of P. mirabilis strains were not recovered, C. freundii formed yellow colonies, and the colonies of the H(2)S-producing E. coli strains were unaffected.

Journal Article↗

PubMed1967

Pathways of glucose metabolism by rough and smooth variants of Bacillus stearothermophilus.

The radiorespirometric method was used to study the pathways of glucose metabolism in the rough and smooth variants of Bacillus stearothermophilus NCA 1518. The Embden-Meyerhof (EM) pathway was more active in the smooth variant than in the rough variant. The participation of the hexose monophosphate shunt (HMP) and EM pathways in the smooth variant was calculated as 4.2 and 95.8%, respectively. The rough variant utilized glucose via the EM pathway exclusively or in combination with a pathway other than the HMP pathway. The estimated efficiency of the tricarboxylic acid system in the rough and smooth variants was 81.3 and 4.9%, respectively.

Bacillus↗