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Biomedical subjects

J E Dowd

Publications and source records attributed to J E Dowd.

24 records · Page 2Linked to original sources
PubMed1975

Effect of repetitive health examinations on blood sugar levels: the Zagreb preliminary study.

In this study recruitment rates of subjects with borderline glucose tolerance were investigated (using the specific procedure described below) and were shown to be 1.8% of the population approached and 2.5% of the population screened. 75 g glucose load yielded higher numbers of subjects with borderline glucose tolerance levels at screening than a 50 g glucose load. However, the numbers of the people finally recruited into the cohort by confirmatory screening were the same when only the 50 g load was used at confirmatory screenings. Subjects recruited in this way remained in the study for 24 months. Repeated health checks had an effect of lowering concentrations of blood glucose after an oral load in treated and control groups, and in those with borderline and those with normal blood glucose values at the initial screening. It is concluded that the process of screening and observation itself has an effect upon glucose tolerance, independent of formal 'treatment'.

Attitude to Health↗
PubMed1973

Repetitive health examinations as an intervention measure.

A cohort of 107 men aged 51-53 years with borderline levels of blood pressure, serum cholesterol, or glucose tolerance was recruited from a general population in central Zagreb, Yugoslavia, and randomized into two groups; one was treated with drugs and the other observed in a similar fashion but not treated. Ninety-five men appeared regularly for the check-ups over a 2-year period. Levels of systolic blood pressure, cholesterol, and glucose showed a substantial decrease over a period of 2 years in both treated and control groups. The possible effect of repeated check-ups and their implications are discussed.

Blood Glucose↗
PubMedDate not supplied

Increased t-PA yields using ultrafiltration of an inhibitory product from CHO fed-batch culture.

Fed-batch operation for the production of t-PA using Chinese Hamster Ovary (CHO) cells was optimized using serial and parallel experimentation. The feed, an isotonic concentrate, was improved to obtain 2- to 2.5-fold increases in integrated viable cell days versus batch. With a low glucose inoculum train, the viability index was further increased up to 4.5-fold. Hydrolysates were substituted for the amino acid portion of the concentrate with no significant change in fed-batch results. The concentrate addition rate was based on a constant 4 pmol/cell.day glucose uptake rate that maintained a relatively constant glucose concentration (approximately 3 mM). Increased viable cell indices did not lead to concomitant increases in t-PA concentrations compared to batch. The fed-batch concentrate and feeding strategy were shown to be effective in hybridoma culture, where a 4-fold increase in viable cell index yielded a 4-fold increase in antibody concentration. The half-life of t-PA decreased from 43 to 15 days with decreasing cell viability (from 92% to 71%), but this was not sufficient to explain the apparent t-PA threshold. Instead, the CHO results were explained by a reduction in t-PA production at higher extracellular t-PA concentrations that limited the fed-batch maximum at 35 mg/L for the cell line investigated. Analysis of both the total and t-PA mRNA levels revealed no response to increasing extracellular t-PA concentrations upon exogenous additions. Instead, intracellular t-PA levels were increased, revealing a possible secretory pathway limitation. A new reactor configuration was developed using an acoustic filter to retain the cells in the reactor while an ultrafiltration module stripped t-PA from the clarified medium before the permeate was returned to the reactor. By adding this harvesting step, the t-PA fed-batch production was increased over 2-fold, up to a yield of 80 mg/L.

Animals↗