Search PubMed⌕ Search

Biomedical subjects

C Price

Publications and source records attributed to C Price.

At least 145 records · Page 8Linked to original sources
PubMed1990

Cross-correlation of cyclosporine concentrations and biochemical measures of kidney and liver function in heart and heart-lung transplant recipients.

Cross-correlation of cyclosporine concentrations with results of biochemical tests of renal and liver function, measured during the first three months post-operatively, was carried out retrospectively in 24 heart and eight heart-lung transplant recipients to assess the temporal relationship between cyclosporine treatment and the development of possible toxic side-effects. We found a statistically significant negative correlation (95% confidence interval of the mean correlation coefficient did not overlap zero) between the five-day mean concentration of cyclosporine in whole blood (but not plasma) as measured with nonselective (NSRIA) and selective radioimmunoassays (SRIA) and the mean reciprocal creatinine concentration measured in the subsequent five days. In 15 of 32 (47%) patients the negative correlation coefficient exceeded 0.7 (high susceptibility), whereas in 11 of 32 (34%) it was between 0.5 and 0.7 (medium susceptibility), and in only six of 32 (19%) was it less than 0.3 (low susceptibility). We found no consistent correlations between cyclosporine measurements and results of other renal-function tests or liver-function tests. This suggests that therapeutic doses of the drug are not hepatotoxic in most patients. There was, however, a significantly correlated decrease in the NSRIA/SRIA ratio and in serum bilirubin concentration with time post-operatively, reflecting improvement in hepatic function and clearance of the cyclosporine metabolites that are detected by NSRIA. Assays of cyclosporine in whole blood, but not in plasma, are of value in anticipating changes in renal function after heart and heart-lung transplantation.

Biomarkers↗
PubMed1989

Basis for changes in DNA recognition by the EcoR124 and EcoR124/3 type I DNA restriction and modification enzymes.

EcoR124 and EcoR124/3 are type I DNA restriction and modification systems. The EcoR124/3 system arose from the EcoR124 system some 15 years ago and at the electron microscopic DNA heteroduplex level the genes for both systems are still apparently identical. We have shown that the DNA sequences recognized by the two systems are GAA(N6)RTCG for EcoR124 and GAA(N7)RTCG for EcoR124/3. The sequences thus differ only in the length of the non-specific spacer. This difference nevertheless places the two specific domains of the EcoR124/3 recognition sequence 0.34 nm further apart and rotates them 36 degrees with respect to those of EcoR124, which implies major structural differences in the proteins recognizing these sequences. We have now determined the nucleotide sequences of the hsdS and hsdM genes of both systems and of the hsdR gene of EcoR124/3. The hsdS gene products provide DNA sequence specificity in both restriction and modification, the hsdM gene products are necessary for modification and all three hsd gene products are required for restriction. The only difference that we have detected between the two systems is that a 12 base-pair sequence towards the middle of the hsdS gene is repeated twice in the EcoR124 gene and three times in the EcoR124/3 gene. We have deleted one of the repeats in the EcoR124/3 gene and shown that this changes the specificity to that of EcoR124. Thus, the extra four amino acids in the middle of the EcoR124/3 hsdS gene product, which in an alpha-helical configuration would extend 0.6 nm, are sufficient to explain the differences in sequence recognition. We suggest that the EcoR124/3 system was generated by an unequal crossing over and argue that this kind of specificity change should not be rare in Nature.

Amino Acid Sequence↗
PubMed1989

Emulsion clearing characteristics in the processing of dental radiographic films.

Recent problems in the fixation of dental X-ray films during processing have led to a study of the clearing of dental emulsions. A method has been devised to compare the behaviour of different emulsions and fixing chemistry under varying conditions of time and temperature. The ease with which emulsions clear has been shown to relate to the fixer chemistry, temperature and time of fixation and, for D-speed films, to the speed of the emulsion. The density of the residual silver halide is approximately inversely proportional to the time and temperature for the ranges explored. E-speed emulsion was less affected than D-speed by fixer chemistry, time and temperature. Fixation is relatively less influenced by temperature changes than development. A suspected relationship between clearing ability and emulsion thickness has not been demonstrated reliably in this investigation. The evaluation of these variables is of relevance to those concerned with the manufacture of films, processors, and processing chemistry as well as to those who process X-ray films.

Radiography, Dental↗
PubMed1988

A community-based support group for HIV positive i.v. drug abusers: the HERO program.

The I.V. drug abuser who has a history of non-compliance is perhaps the most difficult to reach among those at risk for contracting AIDS. This article details one approach being attempted at HERO, that of a community-based support group run by an indeginous worker where the emphasis is on support, education, and outreach to others. HERO's program is also highlighted.

Acquired Immunodeficiency Syndrome↗
PubMed1988

Thrombolytic therapy in acute arterial thrombosis.

The courses of 17 patients who underwent 20 separate attempts at thrombolysis for acute arterial thrombosis are reviewed to clarify the safety and efficacy of this therapy. Seventeen of 20 thrombolyses were angiographically successful. Patients who had correctable lesions identified and reconstructive procedures performed tended to do better than those who did not, and patients who had successful thrombolysis tended to have fewer and less radical amputations. Complications can be reduced by careful, close monitoring of patients undergoing therapy.

Acute Disease↗