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Biomedical subjects

A Franklin

Publications and source records attributed to A Franklin.

At least 109 records · Page 6Linked to original sources
PubMed1980

Antibiotic resistance patterns of coliform bacteria isolated from food.

308 strains of coliform bacteria isolated from food of various origin were identified and their resistance patterns were studied. The strains belonged to 10 different species and Escherichia coli was the most common. Coliforms isolated from samples incubated at 44 degrees C were more often identified as E. coli than coliforms isolated from samples incubated at 37 degrees C. Klebsiella and Enterobacter spp. taken together were, on the contrary, mor often isolated at 37 degrees C than at 44 degrees C. E. coli was most frequently isolated from raw meat and egg products. Klebsiella dn Enterobacter spp. more often in other types of products. 54% of the strains were resistant to at least one of the 9 antibiotics tested. Resistance to nitrofurantoin and sulphaisodimidine was most frequent (30 and 25% respectively). No strain resistant to streptomycin, neomycin or trimethoprim/sulphamethoxazole was registered. 40% of the resistant strains were multiresistant. The lowest number of resistant strains was recorded from custards and desserts and from raw meat products (42 and 46% respectively) and the highest from ice-cream (89%). Multiresistant strains were recorded most frequently from pasteurized milk products, custards and desserts. None of the 66 multiresistant strains tested could transfer the resistance to E. coli in vitro. The results do not indicate that food of animal origin in Sweden represents a source for bacteria with transferable resistance determinants.

Anti-Bacterial Agents↗
PubMed1978

The influence of acute alterations in coronary blood flow on left ventricular diastolic compliance and wall thickness.

The extent to which alterations in the coronary blood flow influence left ventricular (LV) diastolic compliance and wall thickness was studied in isolated, isovolumic (balloon in LV), blood perfused dog hearts. Studies were performed at a ventricular volume which was associated with an LV systolic pressure of 100 mm Hg and changes in LV diastolic pressure (at this constant volume) were taken as changes in LV diastolic complicance. When coronary perfusion pressure was reduced to zero (5 min of global ischemia), LV diastolic wall thickness fell from 9.9 +/- 0.9 mm to 9.2 +/- 0.7 mm (P less than 0.01) and LV diastolic pressure fell only 1.3 mm Hg (from 5.5 +/- 1.0 mm Hg to 4.2 +/- 1.1 mm Hg P less than 0.01). In contrast to these findings in 'near normal' ventricles, global ischemia in severely injured hearts (with unphysiologically high diastolic pressures) resulted in marked reductions in diastolic pressure. Thus, moment to moment changes in coronary blood flow can result in alterations in the diastolic properties of the LV. However, these are extreme interventions, and in the clinical setting, changes in coronary dynamics are unlikely to cause significant changes in LV diastolic pressure.

Animals↗
PubMed1977

A quantitative histological assessment of cellular death, in relation to mitosis, in rat thymus during growth and age involution.

The rates of cellular proliferation and cellular death were investigated in the rat thymus during growth and involution. It was found that the percentage of dead cells gradually increased with age, whilst the rate of cell proliferation declined, indicating that a substantial proportion of lymphocytes that divide in the thymus also die there. It was also found that there exists a density-dependent distribution pattern of mitotic and dead cells and that this distribution pattern changed with age. It is suggested that this mechanism of density-dependent control of the thymus may be an important factor in the age involution of the thymus.

Aging↗
PubMed1977

R-factor-mediated antibiotic resistance in E. coli strains isolated from piglets in Sweden.

E. coli strains, isolated from piglets over the periods 1964-1968 and 1974-1975, were investigated and compared with respect to antibiotic resistance. The frequency of monoresistant strains decreased from 50% in 1964-68 to 27% in 1974-75, while that of strains showing double or multiple resistance increased from 13% to 22%. The proportions of the different resistance determinants were as follows (figures for 1964-68 within parentheses): Tetracycline 23% (49%), sulphaisodimidine 38% (24%), streptomycin 9% (3%), ampicillin 6% (1%), chloramphenicol 6% (0.5%) and neomycin 4% (0%). All the strains were sensitive to trimethoprim. In 1974-75 the resistance determinants were R factor-carried to the percentage numbers as follows: Tetracycline 53%, sulphaisodimidine 64%, streptomycin 77%, neomycin 65%, ampicillin 95% and chloramphenicol 90%. These determinants were with the exception of tetracycline and sulphaisodimidine predominantly present in multiply resistant strains.

Ampicillin↗
PubMed1976

Effect of dehydration and cardiac tamponade on superior mesenteric artery flow: role of vasoactive substances.

The role of serotonin, catecholamines, and angiotensin in the pathogenesis of mesenteric low flow states was investigated in anesthetized dogs by measurement of blood flows with electromagnetic flow meters. During dehydration or cardiac tamponade, a disproportionate decrease in superior mesenteric artery flow was demonstrated, compared with aortic flow, but renal artery flow was relatively better maintained. Depletion of serotonin and catecholamines by pretreatment with reserpine or blocking serotonin's action with methysergide did not alter the disproportionate reduction in mesenteric flow. Disproportionate superior mesenteric artery flow during dehydration and tamponade was associated with increased levels of circulating angiotensin and virtually was abolished by bilateral nephrectomy, by inhibition of enzymatic conversion of angiotensin I to II by Bothrops nonapeptide, and by competitive inhibition of angiotensin II with 1-sar, 8-ala angiotensin II. Exogenous angiotensin administered intravenously to dogs not protected by drug treatment disproportionately decreased superior mesenteric artery flow with less effect on renal artery flow. These results are compatible with the hypothesis that increased circulating levels of angiotensin during dehydration and tamponade contribute to the disproportionate reduction in superior mesenteric artery flow in the anesthetized dog.

Angiotensin II↗
PubMed1975

[The development of drug resistance in Salmonella strains isolated from animals in Sweden 1955-65 and 1973-4(author's transl)].

134 salmonella strains, isolated from animals in 1955-65 were compared to 133 salmonella strains isolated in 1973-74, with regard to their drug resistance and the frequentcy of R-factors. No significant changes were observed during the reference period. Salmonella typhi-murium in comparison with other serotypes harboured a significantly larger number of resistant strains. Of the recently isolated resistant strains that were searched for R-factors, about half the number were carriers. All strains were sensitive to chloramphenicole and neomycin.

Ampicillin↗