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Biomedical subjects

D Wagner

Publications and source records attributed to D Wagner.

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

DNA measurements and ploidy determination of different stages in the life cycle of Sarcocystis muris.

The DNA contents of different stages within the life cycle of Sarcocystis muris were measured cytophotometrically using DNA-specific Feulgen staining. Stages of gamogony were obtained by the transfer of isolated cyst merozoites into cat kidney-cell cultures. For calculation of absolute DNA contents, the amounts of DNA in the parasites were compared with those in chicken erythrocytes, which are known. The measurements revealed that all investigated stages of S. muris contained haploid DNA except the early zygotes, which were diploid. The further development of the zygotes started with a nuclear division, resulting in two daughter nuclei that again revealed haploid DNA values. The results confirm the existence of zygotic meiosis; thus, a haplo-homophasic life cycle is proposed for the Sarcosporidia.

Animals↗
PubMed1990

Characterization of Listeria monocytogenes isolates by Southern blot hybridization.

A synthetic deoxyribonucleotide probe for virulent Listeria monocytogenes, designated ADO7, was evaluated for its ability to identify restriction fragments of L. monocytogenes with nucleic acid sequences homologous with the beta-hemolysin gene by Southern blot hybridization of clinical and food isolates. The synthetic probe hybridized with three restriction fragments (approximately 1.1, 0.86, and 0.76 kb) of the serotype 1/2A isolates. Southern blot hybridization of the serogroup 4B isolates indicated that the nucleic acid sequences homologous with the beta-hemolysin gene probe were limited to a single restriction fragment of approximately 1 kb.

Animals↗
PubMed1990

Androgen dependence and tissue specificity of renin messenger RNA expression in mice.

Testosterone, a steroid hormone which increases blood pressure by hitherto unknown mechanisms, is known to induce renin synthesis in the submandibular gland (SMG) of mice. Since renin as well as all other components of the renin-angiotensin system are present in organs important for cardiovascular control, e.g. the kidney, heart, adrenal gland and brain, it is of interest to study the effect of testosterone on renin gene expression in these organs. Renin messenger (m) RNA concentrations were measured by a solution hybridization assay using a 32P-labeled mouse SMG renin complementary (c) RNA as a radioactive probe (detection limit: 1 pg renin mRNA). Measurements were performed after 2 h and after 2, 7, 14 and 21 days of dihydrotestosterone (DHT) treatment in female NMRI mice. Renin mRNA concentration (values are expressed as pg renin mRNA/ micrograms total RNA) in the SMG was significantly increased after 7 days (108 +/- 22 in controls versus 630 +/- 101 in DHT-treated mice), after 14 days (83 +/- 15 in controls versus 743 +/- 83 in DHT-treated mice) and after 21 days (107 +/- 30 in controls versus 579 +/- 76 in DHT-treated mice), but did not reach levels found in untreated male NMRI mice (1021 +/- 84). In the kidney, a decrease was observed within 21 days, from 43 +/- 4 and 40 +/- 4 to 29 +/- 2 and 22 +/- 1.7 pg/micrograms in controls and DHT-treated groups, respectively.(ABSTRACT TRUNCATED AT 250 WORDS)

Adrenal Glands↗
PubMed1990

Energy expenditure and subsequent nutrient intakes in overfed young men.

We investigated the mechanisms of body weight regulation in young men of normal body weight leading unrestricted lives. Changes in total and resting energy expenditure, body composition, and subsequent voluntary nutrient intakes in response to overeating by 4,230 +/- 115 (SE) kJ/day (1,011 +/- 27 kcal/day) for 21 days were measured in seven subjects consuming a typical diet. On average, 85-90% of the excess energy intake was deposited (with 87% of this amount in fat and 13% in protein on average). There was no detectable difference between individuals in susceptibility to energy deposition. The resting metabolic rate, averaged for fasting and fed states, increased during overfeeding (mean +/- SE, 628 +/- 197 kJ/day, P less than 0.01), but at least some of this amount was obligatory expenditure associated with nutrient assimilation. No significant increase in energy expenditure for physical activity or thermoregulation resulted from overfeeding. Thus energy expenditure did not substantially adapt to increased energy intake. However, significant decreases in voluntary energy intake (1,991 +/- 824 kJ/day, P less than 0.05) and fat intake (48 +/- 11 g/day, P less than 0.01) followed overeating, indicating that adaptive changes in nutrient intakes can contribute significantly to body weight regulation after overeating.

Adult↗
PubMed1990

[Not Available].

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Germany↗
PubMed1989

The calcium requirement for stability and enzymatic activity of two isoforms of barley aleurone alpha-amylase.

alpha-Amylases (EC 3.2.1.1) secreted by the aleurone layer of barley grains are Ca2+-containing metalloenzymes. We studied the effect of Ca2+ on the activity and structure of the two major groups of aleurone alpha-amylase by incubating affinity purified enzyme in solutions containing Ca2+ from pCa 4 to 7. Both groups of isoforms required one atom of Ca2+/molecule of enzyme as determined by isotope exchange, but the two groups differed by more than 10-fold in their affinity for Ca2+. Both groups of alpha-amylase were irreversibly inactivated by incubation in low Ca2+ (pCa 7). This inactivation was not due to changes in primary structure, as measured by molecular weight, but appeared to be the result of changes in secondary and tertiary structure as indicated by circular dichroism spectra, serology, lability in the presence of protease, and fluorescence spectra. Analysis of the predicted secondary structure of barley aleurone alpha-amylase indicates that the Ca2+-binding region of barley amylases is structurally similar to that of mammalian alpha-amylases. Our data indicate that micromolar levels of Ca2+ are required to stabilize the structure of barley alpha-amylases in the endoplasmic reticulum of the aleurone layer where these enzymes are synthesized.

Calcimycin↗
PubMed1989

Local recurrence after curative resection of rectal cancer: a comparison of low anterior resection and abdominoperineal resection.

Local recurrence rates after either low anterior resection or abdominoperineal resection were compared in 109 patients undergoing curative surgery for adenocarcinoma of the rectum between 1979 and 1984. Follow-up information was available for 99 patients (91%). The overall recurrence rate was 19%; ten recurrences (26.3%) for low anterior resections and nine (14.7%) for abdominoperineal resections. (P less than .08). Recurrences were confirmed by biopsy or at reoperation. No significant difference in size of the lesion was evident at initial resection (average largest dimension 4.8 cm for low anterior and 5.5 cm for abdominoperineal resection). The average time to recurrence after resection was 18 months (16.5 months in the low anterior group vs. 19 months in the abdominoperineal group). Mean survival after recurrence was shorter for the abdominoperineal (3.4 months) as compared to the low anterior group (9.5 months) (P = .10). The overall median survival was 21 months (range 0-75 months) in both groups, and 38 patients were alive. Risk factors for recurrence were Dukes C lesions in patients who had a low anterior resection (8/18 or 44% recurrence) and poor histologic differentiation in patients who had either operation (3/6 or 50% recurrence).

Adenocarcinoma↗
PubMed1989

Does hyperketonemia affect protein or glucose kinetics in postabsorptive or traumatized man?

Leucine and glucose turnover were measured using simultaneous infusions of [13C]leucine and [2H]glucose before and during an infusion of Na DL-hydroxybutyrate (Na DL-HB) in overnight-fasted patients the day before and 3 days after total hip replacement. The ketone body infusion before surgery resulted in a significant increase in plasma leucine concentration and leucine turnover, while glucose concentration and turnover decreased. Surgery increased leucine turnover. Ketone body infusion after surgery caused a further increased leucine turnover while turnover fell as before surgery. We suggest that exogenous ketone bodies decrease hepatic glucose production and probably stimulate a rise in protein synthesis above breakdown leading to a decreased nitrogen excretion as observed by other investigators. Despite the metabolic adaptation to trauma, this response was not affected by surgery.

Aged↗
PubMed1989

Nonlinear distribution of atenolol between plasma and cerebrospinal fluid.

Long Evans rats were given atenolol doses ranging from 0.27 to 5.4 mg/kg by intraperitoneal injection Animals were dosed once every 2 hr for a total of five doses. Atenolol concentrations 1 hr after the last dose were measured from simultaneously obtained plasma and cerebrospinal fluid (CSF) samples CSF concentrations of atenolol were not proportional to plasma concentrations. The ratio of CSF/plasma concentrations was higher (0.33) at lower plasma atenolol levels (less than 100 ng/ml) than at the higher atenolol plasma levels (0.05) (P less than 0.001). The relationship between plasma and cerebrospinal fluid atenolol concentrations was best described by the sum of a Michaelis-Menten and linear function. Animals were also given atenolol doses and then subjected to global cerebral ischemia. The relationship of atenolol concentrations from plasma and CSF in these animals was linear, with a constant partition ratio of 0.02. Together these data show that atenolol partitioning between plasma and CSF is nonlinear and possibly an energy-dependent process.

Animals↗
PubMed1989

Impaired cognition in the critically ill elderly patient: clinical implications.

Cognitive impairment is a significant health problem for the critically ill aged and warrants further investigation. Despite the lack of knowledge of all aspects of cognitive impairment, much can be undertaken to improve the care of impaired patients. Nurses must routinely, systematically, and comprehensively assess the cognitive state of each elderly patient at the time of admission and daily throughout hospitalization. On the basis of these assessments, nurses must accurately differentiate among confusion, depression, and dementia in the cognitively impaired patient. To carry out such assessments, modification of existing tools, such as the MMSE, may be necessary. Only through such assessment, however, is it possible to detect, prevent, or treat changes in cognition, and thereby prevent its sequelae.

Aged↗
PubMed1989

Difference in rural and urban mortality: implications for health education and promotion.

Rural health care delivery is often inferior to that of urban areas. Although health services do not have to be identical in the two settings, quality services appropriate for the needs of rural communities are imperative. Moreover, health education and promotion should be seen as an immediate and viable strategy for (a) reducing risk factors and health care needs, and (b) increasing the cost effectiveness of existing services. The appropriateness and prioritization of health care services and health education/promotion can only be realized if health professionals are aware of rural versus urban needs. To facilitate our knowledge of such differences, the mortality rates of the 10 leading causes of death were compared for each county in Ohio and differences between rural and urban mortality were analyzed. Counties were categorized according to "density" (persons per square mile) and "percent urban" (percent of county area classified as urban). The analysis demonstrated that there were no significant differences between rural and urban counties in mortality due to cancer, pulmonary disease, diabetes mellitus, atherosclerosis, and suicide. Mortality related to cardiovascular disease, cerebrovascular disease, accidents, and influenza/pneumonia was significantly higher in rural counties, while deaths due to chronic liver disease were significantly greater in urban counties.

Demography↗
PubMed1989

[Not Available].

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Education, Medical↗