Search PubMed⌕ Search

Biomedical subjects

W Baumgartner

Publications and source records attributed to W Baumgartner.

At least 73 records · Page 4Linked to original sources
PubMed1996

Detection and localization of individual antibody-antigen recognition events by atomic force microscopy.

A methodology has been developed for the study of molecular recognition at the level of single events and for the localization of sites on biosurfaces, in combining force microscopy with molecular recognition by specific ligands. For this goal, a sensor was designed by covalently linking an antibody (anti-human serum albumin, polyclonal) via a flexible spacer to the tip of a force microscope. This sensor permitted detection of single antibody-antigen recognition events by force signals of unique shape with an unbinding force of 244 +/- 22 pN. Analysis revealed that observed unbinding forces originate from the dissociation of individual Fab fragments from a human serum albumin molecule. The two Fab fragments of the antibody were found to bind independently and with equal probability. The flexible linkage provided the antibody with a 6-nm dynamical reach for binding, rendering binding probability high, 0.5 for encounter times of 60 ms. This permitted fast and reliable detection of antigenic sites during lateral scans with a positional accuracy of 1.5 nm. It is indicated that this methodology has promise for characterizing rate constants and kinetics of molecular recognition complexes and for molecular mapping of biosurfaces such as membranes.

Animals↗
PubMed1996

Imaging of single molecule diffusion.

In recent years observations at the level of individual atoms and molecules became possible by microscopy and spectroscopy. Imaging of single fluorescence molecules has been achieved but has so far been restricted to molecules in the immobile state. Here we provide methodology for visualization of the motion of individual fluorescent molecules. It is applied to imaging of the diffusional path of single molecules in a phospholipid membrane by using phospholipids carrying one rhodamine dye molecule. For this methodology, fluorescence microscopy was carried to a sensitivity so that single fluorescent molecules illuminated for only 5 ms were resolvable at a signal/noise ratio of 28. Repeated illuminations permitted direct observation of the diffusional motion of individual molecules with a positional accuracy of 30 nm. Such capability has fascinating potentials in bioscience--for example, to correlate biological functions of cell membranes with movements, spatial organization, and stoichiometries of individual components.

Fluorescent Dyes↗
PubMed1996

Auditory fractal random signals: experimental data and clinical application.

In the mammalian primary cochlear afferents, fractals in the postsynaptic bursting behaviour triggered by a constant perisynaptic release of glutamatergic transmitter agonists have been demonstrated. In order to test the validity of fractally coded auditory signal transmission in man, frequency, intensity and temporal resolution tests were performed in cochlear implanted patients. All patients clearly recognized the fractally coded signals transmitted to the cochlear implants. These first results demonstrate evidence for fractally coded auditory signal transmission in man.

Adult↗
PubMed1996

Histology of the skin and determination of blood and serum parameters during the recovery phase of sarcoptic manage in cattle after avermectin (Ivomec) treatment.

Calves experimentally infested with Sarcoptes bovis were treated 14 weeks post infectionem with an avermectin pour-on preparation (Ivomec). On day 0 before and 14, 28 and 56 days after treatment mite count, scabies lesion score, histological sections of the skin, blood- (number of erythrocytes, PCV, Haemoglobin, MCV, MCH, MCHC, number of leukocytes, differential blood picture) and serum parameter (GOT/AST, GGT, GLDH, glucose, calcium, magnesium, phosphate, sodium, potassium and chloride) and Sarcoptes specific immunoglobulin G and immunoglobulin M were determined. 14 days after treatment no mites could be found in skin scrapings and the mange lesions were in recovery stage. 28 days after treatment the skin mostly was macroscopically unchanged. On all examination days in skin biopsies hyperkeratosis, mostly accompanied by epidermal hyperplasia and perivascular infiltration with eosinophil granulocytes and mononuclear cells was observed. The dominance of eosinophil granulocytes in the tissue decreased after treatment, while mononuclear cells increased and dominated in most cases on day 28 over eosinophil granulocytes. The differential blood count in most cases showed elevated lymphocytes on all examination days, increase of neutrophil granulocytes and decrease of eosinophil granulocytes between day 0 and 14. Monocytes on day 28 showed a marked decrease, thereafter on day 56 a marked elevation. Slightly increased serum enzyme activities were seen with GLDH and GOT on day 0 before treatment and with GLDH on day 56 after treatment. The specific antibody titer against Sarcoptes antigen showed decreasing immunoglobulin G titre and increasing immunoglobulin M titre during the investigation.

Animals↗
PubMed1996

Effects of iron and vitamin E administration on some immunological parameters in pigs.

The effects of intramuscular administration of iron and vitamin E on phagocytic functions of leucocytes and on T-lymphocyte percentages were studied. Twelve pigs with an average body weight (BW) of 40 kg were divided into four treatment groups: +E (20 mg tocopheryl acetate per kg BW); +Fe (10 mg iron dextran per kg BW); +E/+Fe (20 mg tocopheryl acetate + 10 mg iron dextran per kg BW), C (control). Blood samples were collected from the sinus ophthalmicus prior to administration the preparations, and then at 12, 24, 48, 72 hours, and 7 days after administration. The iron injection led to a significant increase (p < 0,05) in plasma iron concentrations in both groups given Ferridextran. An evaluation of the immunological parameters showed the greatest rise in T-lymphocyte percentages as well as in metabolic activity of phagocytes (tetrazolium reduction) in vitamin E treated groups (+E, +E/+Fe) within 24 hours after injection. No interactive effects between vitamin E and iron on the immunological parameters studied were found.

Animals↗
PubMed1996

[Comparative determination of creatine kinase activity in the cerebrospinal fluid and in the blood of health cattle].

Cerebrospinal fluid (CSF) was obtained by puncture of the canalis vertebralis at the lumbosacral foramen. The activities of creatine kinase (CK) in CSF and plasma samples of 68 healthy cattle of different age and breeds were analysed. No significant correlation between CK activities of CSF and plasma was found. The obtained CSF were classified macroscopically into groups of clear-colourless, flaky-colourless, and bloody-flaky samples. The CK activities of clear-colourless CSF showed a normal distribution and were used for further analysis. The range of standard values of CK activities in CSF (0.2-18.7 U/I) was defined after identification of runaways and narrowing of random sample to 95%.

Aging↗
PubMed1995

Basal dephosphorylation controls slow gating of L-type Ca2+ channels in human vascular smooth muscle.

The role of cellular phosphatase activity in regulation of smooth muscle L-type Ca2+ channels was investigated using tautomycin, a potent and specific inhibitor of serin/threonin phosphatases type 1 and 2A. Tautomycin (1-100 nM) inhibited Ca2+ channel activity in smooth muscle cells isolated from human umbilical vein. Tautomycin-induced inhibition of Ca2+ channel activity was due to a reduction of channel availability which originated mainly from prolongation of the lifetime of unavailable states of the channel. Pretreatment of smooth muscle cells with the protein kinase inhibitor H-7 (10 microM) prevented the inhibitory effect of tautomycin. Our results suggest modulation of slow gating between available and unavailable states as a mechanism of phosphorylation-dependent down-regulation of Ca2+ channels in vascular smooth muscle.

Antifungal Agents↗
PubMed1995

Trypsin increases availability and open probability of cardiac L-type Ca2+ channels without affecting inactivation induced by Ca2+.

The patch-clamp technique was employed to investigate the response of single L-type Ca2+ channels to the protease trypsin applied to the intracellular face of excised membrane patches from guinea pig ventricular myocytes. Calpastatin and ATP were used to prevent run-down of Ca2+ channel activity monitored with 96 mM Ba2+ as charge carrier in the presence of 2.5 microM (-)-BAYK 8644. Upon application of trypsin (100 micrograms/ml) channel activity was enhanced fourfold and remained elevated upon removal of trypsin, as expected of a proteolytic, irreversible modification. The trypsin effect was not mediated by a proteolytic activation of protein kinases, as evidenced by the insensitivity of this effect to protein kinase inhibitors. Trypsin-modified Ca2+ channels exhibited the usual run-down phanomenon upon removal of calpastatin and ATP. In ensemble average currents trypsin-induced changes of channel function are apparent as a threefold increase in peak current and a reduction in current inactivation. At the single channel level these effects were based on about a twofold increase in both Ca2+ channels' availability and open probability. Neither the actual number of channels in the patch nor their unitary conductance as well as reversal potential was changed by trypsin. The Ca(2+)-induced inactivation was not impaired, as judged by a comparable sensitivity of trypsin-modified Ca2+ channels to intracellular Ca2+. Similarly, trypsin treatment did not affect the sensitivity of Ca2+ channels to phenylalkylmine inhibition. The observed alterations in channel function are discussed in terms of possible structural correlates.

Adenosine Triphosphate↗
PubMed1995

[Clinical chemical investigation of selected laboratory parameters of cerebrospinal fluid and blood of health cattle].

Selected Parameters in cerebrospinal fluid of adult, healthy cattle of different breeds were analyzed. Group size amounted to 68. Liquor samples were taken by lumbosacral punction. At the same time blood was taken from the Vena jugularis for analysis of the same parameters as in cerebrospinal fluid. Classification into 3 groups based on the macroscopic aspect of the cerebrospinal fluid: clear-colourless, flaky-colourless, bloody-flaky. In the first group all parameters were analyzed in order to fix standard distribution. A range of standard values of every parameter in cerebrospinal fluid was defined after finding of runaways and narrowing of random sample to 95%. Standard values for the parameters were: TP 0.83-1.40 g/l, GLU 1.18-3.20 mmol/l, LAC 1.4-1.9 mmol/l, CK 0.2-18.7 U/l, GLDH 0.7-3.7 U/l, AST 3.2-12.8 U/l. Possibilities to integrate results from the other two groups into these standard values were shown. A linear correlation between cerebrospinal fluid and blood serum values was found to exist for GLU (r = 0.91), LAC (r = 0.55) and GLDH (r = 0.48).

Animals↗
PubMed1995

[Effect of the duration of temporary drying off of one udder quarter in cows and milk yield and quality].

In this study the influence of temporary drying off of one udder quarter regarding milk production and milk quality of lactating and udder healthy cows was examined. The milk yield and milk composition (fat, protein, lactose and somatic cells) produced by each quarter was determined at day 1 until day 7 by use of a special designed milking machine to measure the milk yield of each quarter (control period). From day 8 to 17, the right front = rf (group 1, 6 cows) and left hind = Ih (group 2, 6 cows) quarters respectively were dried off without using any antibiotics for a period of 10 days. The rf (group 3, 5 cows) and Ih (group 4, 6 cows) quarter were dried off without using any antibiotics from day 8 to 10, day 12 to 14 and day 16 to 18. The lactating quarters were milked daily and the examination of the milk was carried out as during the control period. By the end of the experiment (day 41) the milk yield of the dried off udder quarters was only 60-80% of the levels examined during the control period. Therefore no difference concerning the milk yield between all animal tested was observed. The remaining parameters checked approached the levels in the mean range within 10 days after drying off. Bacteriologically the milk samples of udder quarters of group 1 and 2 remained sterile and in milk samples of quarters of group 3 and 4 gram-positive cocci could be isolated.

Animals↗
PubMed1993

Clinical and neurohumoral response of patients with severe congestive heart failure treated with two different captopril dosages.

Although angiotensin converting enzyme inhibitor therapy is an established approach in the treatment of chronic heart failure, the required dosage remains unclear. This open 6 month study investigated the influence of different captopril dosages on the clinical course and neurohumoral activity of patients with severe heart failure (left ventricular ejection fraction < or = 20%). Eighty-five patients in New York Heart Association class II-IV despite treatment with digitalis, diuretics, and captopril (mean dose +/- SEM 28 +/- 2 mg.day-1 at baseline) for > or = 3 months received either 'low dose' captopril (< 75 mg.day-1, mean 32 +/- 2 mg.day-1; n = 46) or 'high dose' captopril (> or = 75 mg.day-1, mean 99 +/- 4 mg.day-1; n = 39) during the follow-up period. Both groups were comparable in clinical, haemodynamic and neurohumoral parameters at baseline. Functional state improved significantly only in the high dose group (P < 0.0001). Of 31 low dose and 20 high dose patients considered as heart transplantation candidates at baseline, 21 low dose and only six high dose patients remained on the waiting list (P < 0.0001). In patients in the low dose group, eight deaths were observed (P < 0.001). Seven patients remained on low dose captopril due to adverse effects. The initially elevated plasma levels of aldosterone and atrial natriuretic peptide decreased significantly only in high dose patients (P < 0.01). Renin increased significantly in both groups. These observations underline the necessity of suppressing neurohumoral overactivation with adequate doses of captopril reflected by sequential humoral plasma determination.

Aldosterone↗
PubMed1993

[Causes of losses in a pig fattening facility].

Losses of fatteners in a pig-husbandry were monitored over a one year period. All fatteners which perished or were slaughtered prematurely were taken into consideration. Out of 10,485 fatteners six hundred (5.7%) pigs were lost prematurely. Of these animals, 360 (60.0%) were slaughtered, and 240 (40.0%) died. Diseases of the respiratory system were the most frequent drop-out reason (32.3%). Pneumonia (mostly pleuropneumonia) was diagnosed in 90.7% of these animals. Thirty one percent of the lost fatteners had diseases of the locomotor system. Of these disorders, 73.1% affected the skeleton and joints, and in 26.9% PSE-syndrome was found. Other disorders were: diseases of the cardiovascular system (13.7%), intestinal tract (10.0%), urogenital tract (1.2%), skin (1.5%), and diseases of other specific organs (5.7%). Cannibalism was found in 2.3% of the lost fatteners, unthriftiness in 1.0%, and in 1.3% the cause of the loss could not be identified. The greatest numbers of fatteners were removed during the cold season, particularly in September. Most of the lost pigs (53.3%) had a body mass between 31 and 60 kg. The highest drop-out rates were found during weeks 2 to 6 and 9 to 12 of the fattening period.

Animals↗
PubMed1993

[Causes of mortality in a swine breeding establishment].

Preweaning losses: During the period from September 1991 to August 1992, from 18021 piglets born alive 3417 died until weaning. Major causes of death were crushing by the sow, low birth weight, starvation, splay-leg disease and enteritis. Of these animals 51.6% died during the first three days of life. Mortality decreased during the preweaning period. Litters with more than 11 pigs had elevated death rates of piglets. Mortality was higher during the cold season (except January). Postweaning losses: During the postweaning period 6.4% of the weaned piglets were lost. Of these piglets 4.1% died and the remaining 2.3% were sold due to umbilical hernia. Diseases of the gastrointestinal tract were the main cause of death. Losses of gilts: During the one-year surveillance period 373 gilts were lost. Most of 18 deceased animals died from bleeding due to gastric ulcers and from purulent bronchopneumonia. 314 (91.1%) of the remaining 355 gilts were sold, the residual 9.9% of the animals were slaughtered mainly because of diseases of the musculoskeletal system. Losses of sows: In the breeding herd of 950 to 1035 animals, 35 sows died and 492 were culled in the course of one year. Most deaths resulted from cardiac failure and splenic torsion. Urogenital and locomotor diseases were the main reason for culling. The sows removed from the herd had produced an average of 3.6 litters, but 52.8% had produced no more than 3 litters. Losses of boars: During the survey 10 boars were slaughtered.

Animals↗
PubMed1993

[Brush biopsy as a new examination method of the upper respiratory tract in cattle and swine].

Several techniques of cytobrush sampling were developed for morphological examination of upper respiratory tract epithelium in cattle and swine. These techniques were evaluated in 30 cattle and swine each, with an age of two weeks to nine years and three weeks to four years respectively. Optimal anatomical locations for sampling were determined. Three cytobrushes of different shapes were constructed to optimize sampling in animals of different ages. Two out of four cytobrush sampling techniques developed provided sufficient cellular material and worked well under field conditions. Rinsing with 0.9% saline largely eliminated mucus and other interfering substances.

Animals↗
PubMed1993

[The hematologic parameters, concentrations of minerals and metabolic products and activities of enzymes in sheep].

In the period of March 1988-March 1989, in 20 Lower Austrian sheep breeding farms blood samples were taken in two-month intervals from sheep of the following breeds: 130 Tyrolean Mountain sheep, 59 German Improved Land breed, 59 East Friesian and 57 German Blackheaded Mutton breed sheep. The following standards for sheep were evaluated: Erythrocytes 7,2-11,9 T/L, haematocrit 0,25-0,41 1/L, haemoglobin 82-147 g/L, lymphocytes 34-80%, segmented neutrophils 10-53%, band neutrophils 1-3%, eosinophilic granulocytes 0-24%, basophilic granulocytes 0-1%, monocytes 0-1%, calcium 1,8-2,8 mmol/L, phosphorus 1,0-2,6 mmol/L, magnesium 0,6-1,3 mmol/L, total protein 53-81 g/L, albumin 22-41 g/L, aspartate aminotransferase 27-81 U/L, alanine aminotransferase 3-25 U/L, gamma glutamic transaminase 24-59 U/L, alkaline phosphatase 44-355 U/L, creatine kinase 3-130 U/L, glutamic dehydrogenase 2,0-36,5 U/L, total bilirubin 0,7-5,1 mumol/L, cholesterol 1,1-3,2 mmol/l, urea nitrogen 1,3-12,7 mmol/l, creatinine 50-112 mumol/L. Apart from that, additional standards for the mentioned breeds of sheep were evaluated, revealing significant differences. Also the age and the time of the year proved to have an influence upon the ascertained blood values.

Age Factors↗
PubMed1992

Seroprevalence survey for Anaplasma marginale-infection of Austrian cattle.

A serologic survey study of 5,076 Austrian cattle farming herds was carried out in the period of December 1988 till March 1990. One animal was randomly selected from each herd and the antibody titer against Anaplasma marginale in blood serum samples was evaluated by means of the complement fixation test. The number of these tested blood samples was 3.6% of 140,081 cattle herd farms of Austria. 109 (2.1%) of the tested animals showed positive titers (1:10) against Anaplasma marginale, in relation to the 140,081 cattle herds 0.08%, 4,786 (94.3%) blood serum samples were sero-negative, 188 (3.8%) reacted anticomplementary. The highest number of antibody-positive animals of 8 tested Austrian districts could be found in Carinthia (46 = 5.7%). In Burgenland all tested sera turned out to be negative. Concerning the distribution of sero-positive animals in Austria it can be stated that a decrease of positive reactors from southern to northern region is evident. A connection between the occurrence of anaplasmosis in Italy, Yugoslavia, Switzerland and Hungary, is postulated as a result of the different systems of keeping cattle in the provinces and the regional increase of tick invasion. Possibly an intensive animal transportation is of importance due to the introduction of the disease mentioned before. The results obtained show that anaplasmosis does occur in different areas of Austria. For control of this disease in Austria it is proposed that all imported cattle should be tested serologically for antibodies against Anaplasma marginale. Other diseases in connection with anemia should be excluded by clinical, serological, blood-, as well as pathological examinations.

Anaplasma↗