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Biomedical subjects

A Rode

Publications and source records attributed to A Rode.

At least 55 records · Page 3Linked to original sources
PubMed1991

Right-branch bundle block in circumpolar Inuit.

The prevalence of right-branch bundle block (RBBB) has been examined in the Inuit residents of Igloolik (69 degrees 40'N, Canadian N.W.T.) over a twenty-year period. Original reports of a very high prevalence of RBBB probably reflected a selective testing of patients with chronic respiratory disease by visiting physicians. Cases of RBBB are certainly seen somewhat more frequently than in a southern community, but the majority of subjects show no more than a slight notching of the R wave of the electrocardiogram, with no appreciable broadening of the QRS complex. While a few of the more marked cases of RBBB may be attributable to chronic respiratory disease, the majority are associated with high normal values for both lung function and predicted maximal oxygen intake. The probable cause is thus a ventricular hypertrophy due to the vigorous physical activity demanded by life in a northern community rather than chronic respiratory disease. The physical demands of life in Igloolik have diminished over the past two decades, and an apparent increase in the prevalence of RBBB over this period is probably due mainly to a great awareness+ of the condition by those reading the electrocardiograms.

Adolescent↗
PubMed1986

Small tandemly repeated DNA sequences of higher plants likely originate from a tRNA gene ancestor.

Several monomers (177 bp) of a tandemly arranged repetitive nuclear DNA sequence of Brassica oleracea have been cloned and sequenced. They share up to 95% homology between one another and up to 80% with other satellite DNA sequences of Cruciferae, suggesting a common ancestor. Both strands of these monomers show more than 50% homology with many tRNA genes; the best homologies have been obtained with Lys and His yeast mitochondrial tRNA genes (respectively 64% and 60%). These results suggest that small tandemly repeated DNA sequences of plants may have evolved from a tRNA gene ancestor. These tandem repeats have probably arisen via a process involving reverse transcription of polymerase III RNA intermediates, as is the case for interspersed DNA sequences of mammalians. A model is proposed to explain the formation of such small tandemly repeated DNA sequences.

Base Sequence↗
PubMed1986

Accuracy of an electronic spirometer--a field trial.

Biological calibration of the Hewlett-Packard electronic spirometer against a Stead-Wells 13.5-litre spirometer shows a good concordance for forced vital capacity (FVC; systematic error 0% in women, 1% in men, probable error 4% in both sexes). However, the electronic device underestimates both 1-second forced expiratory volume (FEV1.0) and maximum mid-expiratory flow rate (MMEF) by 8-10%. This bias is unlikely to reflect technical problems of calibration, voltage drift, condensation of moisture or an inappropriate BTPS calibration; possible causes are a non-linearity in the pneumotachograph response characteristics, a lower resistance to expiration in the electronic device, and greater feedback to the subject and observer with the traditional spirometer. Given reports that similar discrepancies arise with other electronic spirometers, care should be taken in overinterpreting data obtained by such devices.

Adult↗
PubMed1985

Gene conversion as a mechanism for divergence of a chloroplast tRNA gene inserted in the mitochondrial genome of Brassica oleracea.

We have characterized a 1.7 kb sequence, containing a tRNA Leu2 gene shared by the ct and mt genomes of Brassica oleracea. The two sequences are completely homologous except in two short regions where two distinct gene conversion events have occurred between two sets of direct repeats leading to the insertion of 5 bp in the T loop of the mt copy of the ct gene. This is the first evidence that gene conversion represents the initial evolutionary step in inactivation of transferred ct genes in the mt genome. We also indicate that organelle DNA transfer by organelle fusion is an ongoing process which could be useful in genetic engineering.

Brassica↗
PubMed1985

Possible effect of the cell synchronization method on the pattern of 5-bromodeoxyuridine incorporation into early synthesized DNA.

Synchronously and asynchronously growing chick embryo fibroblasts have been used to study the pattern of 5-bromodeoxyuridine (BrdU) incorporation into DNA. In the synchronous cell system, the density of unifilarly substituted DNA is about 0.010 g/ml higher during first half of S phase than during second half of S phase. The density of unifilarly substituted DNA isolated from asynchronously growing cells is similar to that of DNA synthesized during the second half of S phase of synchronously growing cells for a given concentration of analogue in culture medium. Reassociation kinetics experiments have shown the oversubstitution to occur at the level of early synthesized repeated and/or intermediate DNA sequences. It is then assumed that the oversubstitution is due to some metabolic changes caused by the synchronization procedure itself. As BrdU incorporation into early replicating DNA is known to induce alterations of the cell metabolism, the implication of this phenomenon is discussed at the level of the inhibition of transformation which takes place when chick embryo fibroblasts are infected with Rous sarcoma virus during G1 and subsequently treated with BrdU during early S phase.

Animals↗
PubMed1984

Lung function in Canadian Inuit: a follow-up study.

To assess the impact of acculturation on lung function, the forced vital capacity (FVC) and the 1-second forced expiratory volume (FEV1) of 341 Inuit at Igloolik, NWT were measured. The same observers had used the same equipment to test 196 subjects in 1970-71. Cross-sectional analysis suggested that, relative to the previous decade, younger subjects had larger lung volumes (with gains of about 10% in FVC and 5% in FEV1), while the elderly had smaller volumes (with losses of about 22% in FVC and 25% in FEV1). Longitudinal analysis confirmed an accelerating loss of lung function in the older subjects: from age 25 to 35 years men and women had a loss in FVC of 13 and 11 mL/yr respectively, whereas from age 45 to 55 years the corresponding figures were 70 and 38 mL/yr. Cigarette smoking had increased substantially among the Inuit over the decade: the proportion of males and females smoking rose from 64% to 81% and from 85% to 93% respectively. Daily cigarette consumption per smoker increased from 11.8 to 20.2 and from 7.4 to 12.0 among men and women respectively. Nevertheless, the main explanation for the shape of the ageing curve is the survival of a small cohort of elderly Inuit with advanced tuberculosis. With control of this disease future cohorts of the elderly will have better lung function.

Adolescent↗
PubMed1984

Failure to correlate urinary MHPG with clinical response to amitriptyline.

On the basis of studies carried out in a group of 44 patients with endogenous depressive illness, the authors conclude that MHPG in urine is not a good predictor of response to amitriptyline treatment. There are no correlations between MHPG level and clinical improvement after 2 weeks' treatment and with final results of the therapy.

Amitriptyline↗
PubMed1984

Ten years of "civilization": fitness of Canadian Inuit.

Data on the cardiorespiratory fitness of the Canadian Inuit has been obtained before and after 10 yr exposure to "white civilization." The population tested comprises 201 males (aged 9-76 yr) and 143 females (aged 10-69 yr), about 70% of the eligible population of Igloolik (69 degrees 40'N). During direct maximum tests to exhaustion, a higher maximum heart rate was attained in 1980-81 (194.4 beats X min-1) than in 1970-71 (184.5 beats X min-1); this probably reflects a closer approach to a centrally limited maximum as the Inuit have become familiar with white investigators. The Astrand nomogram currently underestimates the directly measured maximum O2 intake (VO2max) by some 3% in subjects making a good maximum effort. Comparing the 1980-81 data with results for 1970-71, there has been a 15% decrease of predicted VO2max, accompanied by a 2- to 4-kg increase of body mass, accumulation of subcutaneous fat, and a decrease of leg extension strength, these changes affecting all subjects except boys aged 9-15 yr. It is suggested that the loss of personal fitness is related to adoption of a more sedentary lifestyle, particularly the use of tracked vehicles in place of walking through deep snow.

Adolescent↗
PubMed1983

Studies on biogenic amine metabolizing enzymes (DBH, COMT, MAO) and pathogenesis of affective illness. I. Plasma dopamine-beta-hydroxylase activity in endogenous depression.

On the basis of studies carried out with a group of 47 patients with endogenous depressive illness, lower plasma activity of dopamine-beta-hydroxylase (DBH) was found as compared with a control group (31 healthy persons). Lower DBH activity particularly characterized bipolar patients. Lowest DBH activity was found in patients with a family history of psychiatric disorders, in particular, affective illness (in comparison with the control group the difference was statistically significant, P less than 0.05). It was noticed, that in a period of remission or significant improvement the enzymatic activity increases, although in some cases the level of activity is still lower than in the control group. There was a correlation between activity of the enzyme and clinical course of the illness and susceptibility to antidepressive drugs. Most of the observed phenomena are related to male patients. On the basis of these studies and data supplied by corresponding literature, concerning in particular the effects of DBH inhibitors (fusaric acid, disulfiram), the authors consider that changes in DBH activity may play a role in the pathogenesis of depression and that DBH deserves further studies, also of genetic nature.

Adult↗
PubMed1982

[Changes, during a synchronous cell cycle, of the level of incorporation of 5-bromodeoxyuridine into DNA of chick embryo fibroblasts].

The determination of the buoyant density of synchronously dividing Chick embryo fibroblast DNA, substituted at various times during the cell cycle by 5-bromodeoxyuridine (BrdU), has been carried out by means of analytical neutral CsCl banding. It has been shown that the buoyant density of BrdU-substituted DNA, duplicated during the first half of S phase, was 0.010 g/ml higher than that of BrdU-substituted DNA duplicated during the second half of S phase. That may reflect a preferential incorporation of the analogue at the beginning of S phase. This peculiar pattern of incorporation would be responsible for the observed inhibition of cell transformation occurring when fibroblasts, infected by Rous sarcoma virus, are grown in the presence of the analogue.

Animals↗