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Biomedical subjects

C Wagner

Publications and source records attributed to C Wagner.

At least 199 records · Page 11Linked to original sources
PubMed1994

Effects of combined inspiratory muscle and cycle ergometer training on exercise performance in patients with COPD.

Cycle ergometer training plays an important role in the rehabilitation of patients with chronic obstructive pulmonary disease (COPD), but the usefulness of specific inspiratory muscle training as part of pulmonary rehabilitation remains uncertain. To determine whether inspiratory muscle training could intensify the known beneficial effects of cycle ergometer training on exercise performance in these patients, we compared the effect of an 8 week inspiratory muscle training combined with cycle ergometer training with that of an 8 week cycle ergometer training alone on inspiratory muscle performance and general exercise capacity. Patients were randomly assigned to the two training groups; 21 patients received additional inspiratory muscle training (Group 1) and 21 did not (Group 2). Maximal sniff assessed oesophageal and transdiaphragmatic pressures served as parameters for global inspiratory muscle strength and diaphragmatic strength, respectively. The duration for which the patient could breathe against a constant inspiratory pressure load was used as an index of inspiratory muscle endurance. Exercise capacity was determined by an incremental symptom-limited cycle ergometer test. After the training period, inspiratory muscle performance improved significantly in the patients with inspiratory muscle training, but not in those without. Both training regimens increased maximal power output and oxygen uptake, but this improvement was significantly greater in the patients with inspiratory muscle training than in those without.(ABSTRACT TRUNCATED AT 250 WORDS)

Breathing Exercises↗
PubMed1994

[Clarification and treatment of teat stenosis using endoscopy].

In ten cows ten stenotic teats were endoscopically examined and treated. For this purpose two different methods were performed: Either the endoscopy was performed through the teat canal or through a small incision in the side of the teat. The endoscopy through the teat canal proved to be a simple and practical method. However, the results were not always clear-cut, and a controlled operation was not possible. Endoscopy through a side access is more expensive but has several advantages. It allows a good view on the Fürstenbergsche Rosette, one of the most frequent locations of stenosis. Additionally, controlled operations of the level of the Fürstenbergsche Rosette are possible once a suitable instrument has been introduced through the teat canal. The additional trauma caused by the access hole is a minor problem. All cows examined and treated by this method could be milked without any problems three days after the operation.

Animals↗
PubMed1994

[The control of Aujeszky's disease using surface vaccination. 2. Serologic studies of the occurrence of latent infection by Aujeszky's disease virus in fattening swine].

The aim of the study was to prove in a region in the North-West of Germany that there is the possibility to decrease the prevalence of latent Aujeszky's Disease infections by means of a systematic vaccination. For this, the most important precondition of the success in a high population immunity that is maintained also in the finishing pig until slaughter. Since it is known that maternal antibodies interfere with the active immunization in the prefattening period, procedures were to be found that guarantee a high immunity in spite of the colostral antibodies. The results of the study show that the existing recommendation for vaccinating fattening pigs are sufficient for the prevalence of latent infections. They also confirm the necessity to carry out a check- and slaughter policy at the end of the eradication program.

Animals↗
PubMed1994

[Assessment of current cardiovascular stress in healthy, young people].

Forty-three young healthy subjects' estimates of their own heart rate, systolic blood pressure, and myocardial oxygen consumption at various intensities of physical work load were investigated. Their estimates were assessed using an ipsative scale, while the physiological parameters were measured continuously and simultaneously. Subjects tended to underestimate their heart rate at every intensity level, men misinterpreting less than women. Blood pressure was underestimated only at moderate physical work loads; with increasing work load blood pressure was overestimated. Estimates of myocardial oxygen consumption were the least biased. This result indicates that parameters other than the heart rate influence cardiac interoception. It seems that estimation of cardiovascular parameters influences the self regulation of physical activities.

Adult↗
PubMed1994

Knowledge of and reported asthma management among South Australian general practitioners.

AIM: This study, carried out in 1989, set out to assess general practitioners' knowledge of asthma management and their reported management practices. METHOD: Of 153 randomly selected South Australian general practitioners 127 (83%) completed a questionnaire designed to explore issues relating to the management of asthma. RESULTS: The survey revealed substantial differences between general practitioners in their knowledge and management practices including the assessment of the severity of asthma, the need for objective monitoring, that is by the use of spirometry and peak flow meters, and the use of medication. Overall, the sampled general practitioners believed that patient-related factors were the main barriers to effective treatment of asthma. CONCLUSION: The findings of this study suggest that ideal asthma management was not being attained. More research is required to ascertain why such variability among practitioners exists and how best to remedy these differences.

Adult↗
PubMed1993

DNA methylation in folate deficiency: use of CpG methylase.

Folate deficiency produces a marked decrease in the ratio of S-adenosylmethionine to S-adenosylhomocysteine. This ratio regulates the activity of many cellular methylation reactions including that of DNA. We used bacterial CpG methylase to evaluate the effect of folate deficiency on methylation of DNA from livers of weanling rats fed an amino acid-defined folate deficient diet. After 4 weeks, liver DNA from deficient animals was undermethylated compared with DNA from pair-fed control animals.

Animals↗
PubMed1993

Hepatic one-carbon metabolism in early folate deficiency in rats.

Glycine N-methyltransferase (GNMT) is inhibited by 5-methyltetrahydrofolate polyglutamate in vitro. It is believed to play a regulatory role in the synthesis de novo of methyl groups. We have used the amino-acid-defined diet of Walzem and Clifford [(1988) J. Nutr. 118, 1089-1096] to determine whether folate deficiency in vivo would affect GNMT activity, as predicted by the studies in vitro. Weanling male rats were fed on the folate-deficient diet or a folate-supplemented diet pair-fed to the deficient group. A third group was fed on the folate-supplemented diet ad libitum. Development of folate deficiency rapidly resulted in decreased levels of S-adenosylmethionine (SAM) and elevation of S-adenosylhomocysteine (SAH). The ratios of SAM to SAH were 1.8, 2.7 and 1.5 in the deficient group for weeks 2, 3 and 4 of the experiment, and the values were 9.7, 7.1 and 8.9 for the pair-fed control group and 10.3, 8.8 and 8.0 for the control group ad libitum fed. The activity of GNMT was significantly higher in the deficient group than in either of the two control groups at each time period. This was not due to increased amounts of GNMT protein, but reflected an increase in specific enzyme activity. Levels of folate in both the cytosol and mitochondria were severely lowered after only 2 weeks on the diet. The distribution of folate coenzymes was also affected by the deficiency, which resulted in a marked increase in the percentage of tetrahydrofolate polyglutamates in both cytosol and mitochondria and a very large decrease in cytosolic 5-methyltetrahydrofolate. The increased GNMT activity is therefore consistent with decreased folate levels and decreased inhibition of enzyme activity.

Animals↗
PubMed1993

Influence of blood sampling from venipunctures and catheter systems on serial determinations of prothrombin activation fragment 1 + 2 and thrombin-antithrombin III complex.

To evaluate the influence of different blood sampling techniques on test results of thrombin-antithrombin III complex (TAT) and prothrombin fragment 1 + 2 (F1 + 2) serial determinations were performed. In six groups of nonrandomized patients (ten patients each) the concentrations of the coagulation markers of blood samples from central catheters (internal jugular, caval, Shaldon, pulmonary artery) and peripheral cannulas (17G and 18G) were compared with those of blood samples obtained simultaneously from direct venipunctures of the contralateral arm. Medians and 25th-75th percentiles of TAT and F1 + 2 concentrations of plasmas obtained from central catheters were not different from those taken from venipunctures. When delta mean values (catheter - venipuncture) were calculated negative results were obtained, indicating lower concentrations measured from blood sampled through central catheters with the exception of blood that taken from Shaldon catheters. Only for TAT concentrations significantly were lower values measured in blood samples taken from internal jugular catheters when compared with blood samples obtained from direct venipunctures. Significantly higher TAT concentrations were determined in blood samples obtained from Shaldon catheters. For both coagulation markers correlations were found between concentrations in blood samples from central catheters and venipunctures. In blood samples taken from peripheral venous cannulas only F1 + 2 concentrations correlated with the concentrations found in samples from direct venipuncture. In contrast to F1 + 2, TAT concentrations measured from blood samples via peripheral cannulas were determined significantly higher than those taken from direct venipunctures.(ABSTRACT TRUNCATED AT 250 WORDS)

Antithrombin III↗
PubMed1993

Pancreatic one-carbon metabolism in early folate deficiency in rats.

An amino acid-defined, folate-deficient diet was used to investigate the regulation of pancreatic glycine N-methyltransferase in vivo. This enzyme modulates the ratio of S-adenosylmethionine to S-adenosylhomocysteine and is inhibited by bound folate in vitro. Rats were fed either a folate-deficient diet, a folate-supplemented diet (pair-fed to the deficient group), or a folate supplemented diet ad libitum and measurements were made after 2, 3, and 4 wk. Folate concentrations were greatly reduced in the folate-deficient pancreas after only 2 wk and pancreatic glycine N-methyltransferase activity was elevated but the amount of immunologically measured enzyme protein was the same. The ratio of S-adenosylmethionine to S-adenosylhomocysteine was rapidly reduced in the deficient pancreas. This ratio was also reduced with age in the ad libitum control rats. The pancreas of deficient rats had more immature secretory granules and the ducts were devoid of secreted material.

Analysis of Variance↗
PubMed1993

An algorithm establishing a defined ergometric cardiovascular load.

A computer-aided procedure is presented to regulate the workload on an ergometric bicycle to an individually fixed level of heart rate as the criterion, applying an integral controller algorithm. The workload is incremented in a few variable steps asymptotically to the target heart rate. A free parameter of the algorithm has been fixed empirically. In the empirical evaluation of the quality of this procedure, a strictly linear relationship of individual Watt increment and rise in heart rate was found in 27 subjects, with a median correlation of 0.95. The procedure is recommended for specific ergometric workload regulation in which an upper limit of rise in heart rate should not be surpassed, e.g. in cardiac rehabilitation. The procedure can also be generalized to comparable regulation tasks, e.g. in the management of blood pressure to avoid an hypertensive crisis.

Adult↗
PubMed1993

[An epidemiological survey to discover the probable places of infection with sleeping sickness in the Central African Republic].

The sleeping sickness focus at Nola-Bilolo in the forest region was the subject of a survey of 142 patients in order to discover their probable places of infection. Seventy of these patients had been detected by active case-finding during a survey conducted in January-February 1991; the other 12 had been discovered by passive case-finding during 1990. The sample of actively detected patients is significantly younger (average 22 +/- 3 years) than the sample detected passively (30 +/- 3 years). This survey highlights the geographical heterogeneity of transmission in the focus. The places where infection is highest are M'Poyo, which with 18% of cases forms the epicentre of the focus and the main reservoir of infecting flies, followed by Bilolo (9%), Mékara (8%), Modigui-Kouna, Ziendi and Domissili (7%). The patients, 95% of whom belong to the M'Bimou tribe, all engage in agriculture; the main activities are coffee-growing for men and the steeping of casava in the river for women. These two activities determine the main places and times of human-tsetse contact. The information obtained by listing the cases detected passively from medical registers is inadequate for locating the places of transmission. The information gathered during active case-finding campaigns by the mobile teams offers a better approach. The method used here, which is recommended, consists of matching the replies given by the patients about their points of contact with the tsetse flies, not just with their places of residence but also with their successive movements and their places of work. The rigour demanded by this kind of approach can only be ensured by a specific survey. This survey also made it possible to demonstrate substantial movements from village to village, which appear to be characteristic of this focus. The results indicate that poorly targeted vector control is likely to be doomed to failure. The study makes it possible to specify priority areas for vector control by trapping and to avoid a "blind" control strategy whereby the whole focus is swamped with traps. The latter strategy is not financially feasible for many countries of tropical Africa.

Adolescent↗
PubMed1993

A pattern of decline in general practice obstetric care in Adelaide.

Some educational, training and politico-economic reasons for the decline in GP obstetrics in Adelaide, South Australia, are described. It is recommended that similar studies be done in other centres in Australia to evaluate the general nature of the findings.

Clinical Competence↗
PubMed1993

[Allergic rhinitis, respiratory obstruction and bronchial asthma in the Vienna population].

In the present study the incidence of bronchial asthma, airway complaints, and allergic rhinitis was investigated in a randomized population section including 3000 male and female inhabitants of Vienna (sex ratio 1:1), aged 20-44. Data on complaints in the respiratory tract were obtained from a total of 71% of the study population. Our results suggest that 14.7% of the entire population was suffering from allergic rhinitis (16.4% male versus 13.0% female; p < 0.05). Airway complaints such as wheezing, whistling, and feeling of tightness in the chest, awakening because of shortness of breath or cough were frequently reported, with no major differences between male and female subjects. The overall percentage of study subjects stating that they had suffered from airway complaints in the year before, i.e., the percentage of those giving affirmative answers to one of the questions, was 29%. Bronchial asthma was calculated to be present in 5.1% of the entire population (5.9 male versus 4.4 female). Attacks of asthma were reported by only 2.2% of the subjects, which gives an indication of the discrepancy between identified and unidentified bronchial asthma. Allergic rhinitis is correlated to, and constitutes a risk factor for the occurrence of complaints in the respiratory tract; public health policy should therefore be aimed at the prevention or early treatment of allergic rhinitis, and at reducing the proportion of cases suffering from unidentified bronchial asthma.

Adult↗
PubMed1992

Purification and properties of pancreatic glycine N-methyltransferase.

Glycine N-methyltransferase (GNMT) regulates the ratio of S-adenosylmethionine to S-adenosylhomocysteine. It is very abundant in liver cytosol and earlier studies have shown it to be present in high concentrations in the pancreas. We have previously reported that liver GNMT is allosterically inhibited by 5-methyltetrahydrofolate pentaglutamate (5-CH3-H4PteGlu5), and proposed that this represents a metabolic control mechanism which links the de novo synthesis of methyl groups to the methylating ability of the liver. We now report that pancreatic GNMT also contains bound folate in vivo. Purified pancreatic GNMT is inhibited by reduced folate polyglutamates in vitro. The KI for the synthetic (R,S)5-CH3-H4PteGlu5 is 2.4 x 10(-7) M. The natural (S) form of 5-CH3-H4PteGlu5 is tightly bound and has a Kd of 1.3 x 10(-7) M. One mole is bound per enzyme tetramer. These studies suggest that GNMT is important in the regulation of methyl group metabolism in the pancreas as well as in the liver.

Animals↗