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Biomedical subjects

J W Thomson

Publications and source records attributed to J W Thomson.

32 records · Page 2Linked to original sources
PubMed1976

Laboratory and field control of clinical mastitis in dairy cows around Bulawayo.

The organisms responsible for clinical mastitis in dairly herds around Bulawayo were identified and their antibiotic sensitivity was determined. Streptococci, staphylococci and coliforms were responsible for 37%, 28% and 29,5% of cases respectively. Antibiotic resistance increased over the 3 year period. The high incidence of coliform mastitis is discussed, as is the effect of dry cow therapy on peri-natal mastitis and the nature of the scheme of control. The laboratory is considered an essential adjunct to other control methods.

Animals↗
PubMed1974

The operative cholangiogram: its interpretation, accuracy and value in association with cholecystectomy.

The value and errors of one method of operative cholangiography were assessed prospectively with the aim of reducing further the incidence of unnecessary explorations of the common bile duct and the occurrence of residual stones. Operative cholangiograms were obtained using a cystic duct cannula in 174 cases, the technical failure rate being 2%. All cases were followed up using intravenous cholangiography where necessary. Of 129 judged normal by the operator, 2 were found to have common bile duct stones-false negative rate 1%. Of 45 judged abnormal by the operator, 10 had negative explorations- false positive rate 6%. Anomalies were discovered in 12% of patients. It is concluded that meticulous technique and accurate interpretation are essential for the best results. The high incidence of anatomical variations present is of interest and this alone emphasises the necessity of carrying out the investigation and the need of experienced interpretation.

Biliary Tract Diseases↗
PubMed1973

Substrate binding to an active creatine kinase with a thiol-bound mercurinitrophenol chromophoric probe.

A mol of creatine kinase (EC 2.7.3.2), an enzyme with two identical subunits can be titrated very rapidly and stoichiometrically with 2 mol of 2-chloromercuri-4-nitrophenol, an environmentally sensitive chromophoric probe specific for thiols. Chemical modification does not inactivate the enzyme nor can the reaction be prevented by a dead-end quaternary complex of enzyme, magnesium, ADP, and creatine with added nitrate. Creatine kinase modified with the chromophoric reagent can be further reacted with 200-fold molar excess of iodoacetamide, resulting in loss of enzymatic activity but without release of bound mercurinitrophenol. The tightly bound chromophore has spectral properties different from free unbound mercurinitrophenol. Only addition of MgADP, or MgATP and creatine, or nitrate, to the modified though active enzyme causes further changes in the visible spectrum of the bound nitrophenol. Addition of nitrate, Mg, ADP, and creatine to the enzyme with bound reporter group, in the order indicated, caused spectral changes; each addition gave a different spectrum.

Adenosine Triphosphate↗