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Biomedical subjects

G Leitner

Publications and source records attributed to G Leitner.

At least 55 records · Page 3Linked to original sources
PubMed1997

[Glycosylated hemoglobin and glycosylated proteins for metabolic control of diabetes mellitus].

The target of therapy in patients with diabetes mellitus is preventing the development of late complications due to nearly normal blood glucose values. For the diagnosis and control of therapy in routine management of diabetes mellitus, determination of glycated haemoglobin (HbA1c) and fructosamine in addition to blood glucose values are of equal importance. This report stresses the clinical use, standard-determination methods and interpretation of glycated protein values. The problems of haemoglobin variants detected in Austria interfering with determination of HbA1c using the high performance liquid chromatography method and the suggestions of the American Diabetes Association for using glycated haemoglobin and fructosamine are discussed as well.

Blood Glucose↗
PubMed1996

Genetic differences and heritability of antibody response to Escherichia coli vaccination in young broiler chicks.

Broiler chicken lines, selected divergently for high (HC) or low (LC) antibody titer to Escherichia coli vaccination at an early age, were evaluated for antibody response at the S5 and S9 generations of selection. The full-pedigreed populations consisted of about 300 and 400 chicks per line in S5 and S9, respectively. At S5, all chicks were vaccinated at 10 d of age (VA10) and antibody titer was determined twice for each chick, at 8 and 12 d postvaccination (dPV). At S9, each line was divided into two equal groups; in the HC line, one group was vaccinated at 8 d of age (VA8), and the other at 10 d of age (VA10), whereas in the LC line, one group was VA10 and the other was VA12. Antibody titers were determined twice for each chick, 8 and 10 dPV. The effects of line, age at vaccination (VA), and days for antibody development (dPV) were tested, and the heritability of antibody titer was estimated for each line-VA-dPV set of data. The HC and LC lines differed significantly in the maturation process of their immune systems. The percentage of chicks with detectable antibody at 18 d of age (VA10-8 dPV) among HC chicks was significantly higher than among LC chicks (85 vs 48% in S5 and 96 vs 63% in S9). In S9, 90% of the HC chicks had already responded at 16 d of age and 100% at 18 d of age, whereas among the LC chicks, only 62% were positive at 18 d of age, increasing to no more than 98% at 22 d of age. The results demonstrates that selection of antibody titer to E. coli vaccination at 20 d of age actually affects the earliest age of immune response, as the immune system of the HC chicks matures earlier than that of the LC chicks. The HC S9 chicks at 8 dPV exhibited a fourfold higher antibody titer than their LC 8 counterparts. This difference further increased at 10 dPV, indicating that the lines differed not only in the level of antibody at a specific age, but also in their rate of antibody titer development. The highest estimate of heritability was very similar in both lines (0.44 and 0.42 in HC and LC, respectively). However, in the HC line this heritability was exhibited at 18 d of age, and only at 22 d in the LC line. Thus, both lines have a similar amount of genetic variation for early immune response, but in the HC line this variation is fully expressed 4 d earlier than in the LC line. These results suggest that selection for high or low antibody response in young chicks results in early or late antibody production, respectively. To maximize the efficiency of selection for early immune response, one must determine the best vaccination age and timing of antibody evaluation in any given population, and these values must be revalidated and updated as selection proceeds.

Age Factors↗
PubMed1996

Effects of gonadal steroids and their antagonists on the humoral immune response of immune-selected broiler chicks.

The effects of gonadal hormones, testosterone (Te) and estrogen (E2) as factors in the development of the immune system in two lines, high response (HC) and low response (LC), of broiler chickens divergently selected for early or late immune maturation were studied. For this purpose, plasma Te and E2 levels were tested and correlated with immune response. Also, the effects of exogenous administration of gonadal steroids testosterone propionate (TP), dihydrotestosterone (DHT), and estradiol 3-benzoate (EB), and the nonsteroidal androgen antagonist flutomide (Flu) and anti-estrogen tamoxifen (Tam) on the immune system were studied. Male chicks of the LC line had a higher level of endogenous Te during first 30 d posthatch. The administration of TP or DHT had no noticeable effect on the humoral immune response, whereas DHT suppressed growth of the bursa of Fabricius of both sexes of HC line. No differences in the endogenous E2 level were observed between sexes in either line. Administration of EB inhibited comb and testicle growth and enhanced significantly the humoral immune response to Escherichia coli and sheep erythrocytes (SRBC). The anti-androgen Flu and anti-estrogen Tam strongly inhibited humoral immune response to E. coli and SRBC antigen, whereas no effects on comb and testicle growth were observed. The experimental results suggest that gonadal hormones have similar principal posthatch effects in avian as in mammals; however, the gonadal steroids prehatch effects and the genetic-physiological-environmental effects require further study.

Analysis of Variance↗
PubMed1995

Temporary increase of plasma epinephrine affects stress responses 24 h later.

The impact of temporary (24 h) implantation of epinephrine tables on catecholamine responses to handling and immobilization 24 h later was investigated in rats. Free plasma epinephrine responded with an increase to both types of stress (77% and 326%, respectively) while controls showed a weaker response to immobilization. The basal level of free plasma norepinephrine was reduced (46% vs. controls) after epinephrine pretreatment, but neither handling nor immobilization had a specific effect on this parameter. In contrast, the basal level of free plasma dopamine was increased after epinephrine pretreatment (183%); however, as with free norepinephrine, there was no specific effect of handling or immobilization. Conjugated plasma epinephrine was significantly lowered after epinephrine pretreatment (44% vs. controls). It did not respond specifically to handling or immobilization except for a stronger response after 20 min of immobilization. Conjugated norepinephrine showed no specific response, but increased nonspecifically after extended immobilization. Conjugated dopamine was lowered (30%-48%) in the E-treated group and did not respond to stress at any time. Thus, a temporary elevation of free plasma epinephrine affected, differentially, basal levels and stress responses of free and conjugated catecholamines 24 h later.

Adrenergic Agonists↗
PubMed1995

[Nutrition and osteoporosis: a nutritional analysis of women in postmenopause].

In a cross-sectional study the effects of several nutritional factors on the manifestations of osteoporosis were investigated in 23 postmenopausal women aged 50 to 70 years. Twelve women (group 1) with osteoporosis and eleven healthy control subjects (group 2) were instructed to keep a seven-day nutritional record. Body mass index (BMI) was recorded, and radiological and bone mineral density investigations were undertaken. The daily total energy, protein, fat, carbohydrate, fiber, oxalic acid, calcium, magnesium, phosphorus, sodium, fluoride, zinc, copper, manganese, vitamin C, D, and K intake were analysed within the framework of a nutritional science program. No intergroup differences were observed with regard to total energy intake, nutritional components and BMI; however, age and years since the menopause differed significantly (p < 0.05). The results suggest that the manifestation of osteoporosis in women is influenced to a greater extent by age and years since the menopause than by the distribution of nutritional factors in a normal mixed diet. However, further studies are essential to evaluate the role of dietary composition on the manifestations of osteoporosis.

Age Factors↗
PubMed1995

[Infections caused by Campylobacter jejuni in the pediatric department of the Leoben district hospital 1983-1993].

Over the period 1983-1993 10,344 stool cultures were undertaken in children with gastrointestinal symptoms at the pediatric department of the Landeskrankenhaus Leoben. Campylobacter jejuni was diagnosed as pathogen in 238 cultures taken from 196 patients aged one month to 16 years. Thus, Campylobacter jejuni infections (2.3% of all stool cultures) were second in frequency to various forms of salmonella (6.1% of all stool cultures; 332 patients). Apart from diarrhea (92% of cases), the most frequent clinical features were fever exceeding 38 degrees C (61%), abdominal pain (58%), blood in the stools (48%) and vomiting (34%). Treatment was based on appropriate diet. Fluid replacement with glucose-electrolyte infusions was required in 24% of the patients and erythromycin was administered orally in 30% of cases.

Adolescent↗
PubMed1995

Improved glucose tolerance by acute vanadate but not by selenate exposure in genetically obese rats (fa/fa).

OBJECTIVE: To describe the impact of acute vanadate and selenate exposure on glucose tolerance of obese Zucker rats (fa/fa). DESIGN: Intravenous glucose tolerance tests (2.4 mmol/kg, continuously from 0 to 30 min) were performed in conscious Zucker rats exposed to a bolus-continuous infusion of sodium vanadate (2.45 mumol/h) or sodium selenate (0.90 and 2.45 mumol/h) and were compared to intraindividual control experiments with saline infusion. RESULTS: Vanadate infusion improved glucose tolerance and decreased insulin release, as shown by total areas under the curves (0-120 min: Glucose, min.mmol/l: control, 983 +/- 59 vs vanadate, 915 +/- 54, P < 0.02; Insulin min.nmol/l: control, 117.5 +/- 19.9 vs vanadate, 88.5 +/- 26.2, P < 0.01). In contrast, infusion of selenate increased glucose induced insulin release during the first phase of the IVGTT (0-60 min, incremental area under the insulin curve: by 57% and 110% for low and high selenate infusion rate, respectively) and transiently improved glucose tolerance (0-60 min, decrease of incremental area under the glucose curve: 31% and 28%, respectively). That effect of selenate was lost with progression of the experiment during the second hour of the IVGTT, when plasma glucose continued to decline slowly in control experiments, but increased in selenate exposed rats without any adequate insulin secretory response to hyperglycemia. CONCLUSION: The results demonstrate improved glucose tolerance and decreased plasma insulin concentration during acute vanadate exposure. Only a transient insulinotropic effect with improved glucose tolerance is induced during acute selenate exposure, and is followed by progressive development of hyperglycemia indicating selenate toxicity.

Animals↗
PubMed1994

Impact of stress and triiodothyronine on plasma magnesium fractions.

The differential regulation of free and bound plasma magnesium was studied in healthy volunteers exposed to various forms of stress, and patients screened for thyroid disorder. Both ergometric (7 min) and psychological (45 min) stress had no effect on free plasma magnesium, but increased the bound fraction. Before combined physical and psychological stress (45 min aerobatics) there was no correlation between the plasma fractions of magnesium; thereafter, there was a strong negative correlation between increased free and decreased bound magnesium. Three days of training in ground combat increased significantly the plasma levels of both magnesium fractions. Patients screened for thyroid disorder had a significant, positive correlation between both plasma fractions of magnesium, and a highly significant negative correlation between plasma T3 and the two magnesium fractions. No clear correlation between plasma catecholamines and magnesium levels was seen under any of the above conditions. Overall, the data show that the evaluation of the functions of circulating magnesium requires the specific measurement of the free and bound fractions.

Austria↗
PubMed1994

Parental effect on the humoral immune response to Escherichia coli and Newcastle disease virus in young broiler chicks.

Genetic and environmental variables influence animal resistance to disease infection. In addition, maternal effects were also found in studies with egg-type chicken lines. In our laboratory, meat-type chicken lines were divergently selected for either early or late maturation of the immune system, based on family and individual antibody responsiveness at 10 d of age. The high-antibody (HC) and low-antibody (LC) lines differed significantly in the early immune response to Escherichia coli, to Newcastle disease virus (NDV) vaccination, and to several other immune functions. Reciprocal crosses between the HC and LC lines were performed over 2 yr at three different locations. Immune responses to E. coli and NDV vaccination provided separate estimates of maternal and paternal effects. Dam effect on immune response to E. coli vaccine was significantly larger than sire effect; the antibody titer in both reciprocal crosses was intermediate between the parental lines, but the mean titer of the HC x LC cross was significantly lower than that of the LC x HC cross. Similar, but not significant, ranking of crosses was observed for the response to NDV. Evidently, the level of the offspring humoral immune response was more a dam than a sire effect.

Animals↗
PubMed1993

Release of conjugated catecholamines by the adrenal medulla equivalent of the American eel, Anguilla rostrata.

The in vivo perfusate of the cardiovascular system of the American eel (Anguilla rostrata) contains both free and conjugated fractions of dopamine, norepinephrine, and epinephrine. In vitro perifusion revealed that conjugated catecholamines are released from the adrenal medulla equivalent. Together with similar reports on mammals, this suggests that conjugated catecholamines are phylogenetically wide-spread components of the secretory cocktail of chromaffin cells. The present findings are compatible with an "active" role of the catecholamine conjugates.

Adrenal Medulla↗
PubMed1993

Cytological and biochemical studies on chromaffin cells in the head kidney of Gasterosteus aculeatus (Teleostei, Gasterosteidae).

Adrenal chromaffin cells in the head kidney of the stickleback Gasterosteus aculeatus were examined by ultrastructural analysis and determination, by HPLC, of the catecholamine content (adrenaline, noradrenaline, and dopamine). Chromaffin cells are characterized by the presence of membrane-bound vesicles and two cell types were identified: (i) those with vesicles containing a strongly electron-dense core; and (ii) those with vesicles that are completely electron lucent or containing smaller and less-dense granules. HPLC analysis revealed the presence of adrenaline and noradrenaline in both right and left head kidneys. Dopamine was not detected. Cytological and biochemical data suggest that the cells with electron-dense granules contain noradrenaline and those with electron-lucent vesicles contain adrenaline.

Animals↗
PubMed1993

Response of plasma cortisol to environmental cadmium in the eel, Anguilla rostrata LeSueur.

1. Long-term exposure (16 weeks) of the American eel, Anguilla rostrata, to an environmentally realistic concentration of cadmium (150 micrograms/l) causes a chronic elevation of plasma cortisol. During this time span, the eels retain the ability to respond to a weak additional stress (CO2 bubbles for 1 min) with a further increase in plasma cortisol. 2. Plasma glucose levels are significantly lowered after two weeks of exposure to cadmium (75 and 150 micrograms/l). However, subsequently they return close to control levels. 3. It is concluded that (a) a moderate cadmium pollution of the eel's habitat suffices to cause chronic stimulation of the eel's adrenocortical axis, and (b) the resulting continued hypercortisolemia must seriously affect the eel's metabolism, immunosystem, gonadal maturation, and ability to migrate to its spawning grounds.

Analysis of Variance↗
PubMed1993

Major histocompatibility complex class IV restriction fragment length polymorphism markers in replicated meat-type chicken lines divergently selected for high or low early immune response.

Information on MHC may improve the efficiency of selection for immunological traits via the application of marker assisted selection or by selecting directly for a specific restriction fragment length polymorphism (RFLP) band or MHC haplotype. An experimental procedure is presented here for identifying MHC genes that are related to early immune response. A Class IV cDNA clone was used to probe Southern blots of erythrocyte genomic DNA from chickens. Chickens were taken from the second (S2) and third (S3) generations of replicated lines divergently selected for high antibody response (HC1, HC2) or low antibody response (LC1, LC2) to Escherichia coli vaccination at 10 days of age. These selection criteria have been found to be associated with other immunological parameters. The hypothesis that these selected lines differ in their MHC loci was evaluated by comparing the frequencies of MHC RFLP markers (single RFLP bands) and haplotypes (patterns of RFLP bands). The significant differences between LC and HC in the frequency of many MHC RFLP bands and of five MHC haplotypes indicate that early antibody production is influenced by MHC genes. The reliability of the association between the selection and frequency differences was tested and proven in most cases by analysis of the replicated lines. These differences in RFLP markers represent a change in allelic frequencies in MHC genes, probably due to selection. The results imply a connection between the Class IV genes and early antibody production, and they show the potential of prospective breeding not only by immunological phenotype but also by genotype (i.e., using RFLP markers of the MHC).

Animals↗
PubMed1992

Immunological parameters in meat-type chicken lines divergently selected by antibody response to Escherichia coli vaccination.

Our group has established two lines of meat-type chickens divergently selected for early (HC line) and late (LC line) antibody responsiveness at 10 days of age to immunization with inactivated pathogenic Escherichia coli bacteria. The question addressed in the study presented here is whether this selection has changed other immunological responses, increasing the overall 'early' immunocompetence. Broilers of the third and fourth generations (S3 and S4) of the selected lines (HC and LC) and a control, unselected line (CT) were vaccinated at 10 days of age with E. coli vaccine, Newcastle virus vaccine (NDV), sheep erythrocytes (SRBC) or bovine serum albumin (BSA). Line-HC chicks exhibited higher antibody titers to E. coli, NDV and SRBC than CT or LC chicks. At 20 days of age HC chicks demonstrated a higher total protein and a higher beta- and gamma-globulin levels in their serum. At 21 days of age, HC chicks cleared carbon particles faster than LC chicks. Peripheral blood lymphocytes (PBL) from HC chicks vaccinated with E. coli vaccine, proliferated in vitro more actively in the presence of the stimulating antigen than the PBL of LC chicks. Peripheral blood lymphocytes (PBL) obtained from HC-line chicks exhibited a higher proliferative response to concanavalin A (Con A)-, phytohemagglutinin (PHA)- or pokeweed mitogen (PWM)-stimulation than LC PBL. These results demonstrate that the selection for high or low antibody response to E. coli at a young age resulted also in a significant change in the response of other parameters of the immune system. The high response to E. coli was found to be associated with a high antibody response to other antigens (NDV and SRBC), increased phagocytic activity and increased proliferative response to antigen or mitogens. The selection most probably affected early immunocompetence.

Aging↗
PubMed1992

Replicated divergent selection of broiler chickens for high or low early antibody response to Escherichia coli vaccination.

Four sublines of broiler chickens were selected from a base population for three generations for high or low antibody response to vaccination with Escherichia coli at 10 days of age. Two sublines were selected for a high response (HC) and two for a low response (LC). Realized heritability estimates over three generations of selection for each pair of replicated lines averaged .23 in HC lines and .32 in LC lines. No correlated response in the important production trait, body weight at marketing age, was observed. The ability to survive pathogenic E. coli challenge with or without prevaccination showed no differences between the lines in the unvaccinated chicks, although following vaccination there was higher mortality and morbidity in the LC lines. These data suggest that the use of antibody response in young chicks to E. coli vaccine may be a useful genetic indication of more general disease resistance.

Animals↗
PubMed1992

[A malignant mesothelioma of the peritoneum following radiotherapy. A case report].

A 49-year-old woman developed ascites 31 years after radiation therapy for ovarian cancer and was admitted to hospital 1 year later. Diffuse infiltration of both sheets of the peritoneum was found by CT, which on histological investigation turned out to be an advanced malignant peritoneal carcinoma. When there is a history of radiation exposure, malignant peritoneal mesothelioma should be considered as the cause of ascites.

Female↗
PubMed1991

Decreased resistance and immune response to Escherichia coli infection in chicks with low or high intakes of vitamin A.

The effects of vitamin A excess of insufficiency on resistance to Escherichia coli infection and subsequent anti-E. coli immune response were examined in chicks. Chicks receiving depleted (0 microgram/kg), sufficient (0.85 mg/kg) or excess (1000 mg/kg) levels of vitamin A in their feed were inoculated by a subcutaneous injection of pathogenic E. coli (1 x 10(9) and 2 x 10(9) cfu per chick). Susceptibility to E. coli was determined by mortality, morbidity and immune responses (antibody production and T lymphocyte proliferation). Excess of insufficient vitamin A led to increased susceptibility of chicks of E. coli infection; this was accompanied by depressed immune responses. Chicks receiving excess vitamin A were more sensitive to E. coli than vitamin A-depleted chicks. This was reflected in higher mortality and morbidity rates and in severely depressed immune responses. In contrast to chicks receiving excess vitamin A, T lymphocyte responses (though not antibody responses) of vitamin A-depleted chicks achieved levels similar to those of vitamin A-sufficient birds with a lag period of 6 to 10 d. Therefore, reduction in resistance to E. coli infection, resulting from vitamin A excess or deficiency, probably was compounded by a delayed immune response.

Animals↗