Biomedical subjects

H Kluge

Publications and source records attributed to H Kluge.

At least 19 recordsLinked to original sources

PubMed2000

Observation of the continuous stern-gerlach effect on an electron bound in an atomic Ion

We report on the first observation of the continuous Stern-Gerlach effect on an electron bound in an atomic ion. The measurement was performed on a single hydrogenlike ion ( 12C5+) in a Penning trap. The measured g factor of the bound electron, g = 2.001 042(2), is in excellent agreement with the theoretical value, confirming the relativistic correction at a level of 0.1%. This proves the possibility of g-factor determinations on atomic ions to high precision by using the continuous Stern-Gerlach effect. The result demonstrates the feasibility of conducting experiments on single heavy highly charged ions to test quantum electrodynamics in the strong electric field of the nucleus.

Journal Article↗

PubMed2000

Altered renal function in growth-restricted newborn piglets.

The effect of intrauterine growth restriction (IUGR) on renal hemodynamics and excretory functions was studied in 76 newborn piglets 12-27 h old. The experiments were performed on anesthetized animals divided into normal-weight piglets and IUGR piglets according to their birth weight. The "normal-weight" category included animals with a birth weight >40th percentile (piglets heavier than 1,220 g); the IUGR category included animals with a birth weight >5th and <10th percentiles (piglets with a birth weight between 733 g and 853 g). Cardiac output and renal blood flow were measured by the colored microsphere technique. Urine was collected from catheters placed in the ureters. This animal model of naturally occurring growth retardation in swine gives asymmetric growth with an increase in the mean ratio of brain weight to liver weight from 1.02 to 1.85 (P<0.01). Thus there was only a small reduction in brain weight (11%). In contrast, the reduction in the weight of liver (50%) and kidney (46%) was proportional to that in body weight (46%). Heart rate, cardiac output, arterial blood gases, and pH were similar in normal-weight and IUGR piglets, but arterial blood pressure and arterial glucose content were significantly reduced in IUGR piglets (P<0.01). Moreover, IUGR piglets had higher plasma catecholamine levels (P<0.05). Renal blood flow and renal vascular resistance were similar in the normal-weight and in the IUGR groups. However, in IUGR animals, glomerular filtration rate was significantly less than in the controls (P<0.05). Normal-weight and IUGR newborn piglets reabsorbed sodium very efficiently, the fractional sodium excretion was less than 1% in both groups. We conclude that renal blood flow is maintained in relation to kidney and body weight in IUGR newborns, but that important renal excretory functions are compromised due to IUGR.

Animals↗

PubMed2000

Accelerated contractile function and improved fatigue resistance of calf muscles in newborn piglets with IUGR.

Asymmetrical intrauterine growth restriction is denoted by disproportional reduction of muscle mass compared with body weight reduction. However, effects on contractile function or tissue development of skeletal muscles were not studied until now. Therefore, isometric force output of serial-stimulated hindlimb plantar flexors was measured in thiopental-anesthetized normal weight (NW) and intrauterine growth-restricted (IUGR) 1-day-old piglets under conditions of normal, reduced (aortic cross clamping), and reestablished (clamp release) blood supply (measured by colored microspheres technique). Furthermore, muscle fiber type distribution was determined after histochemical staining, specific muscle force of the plantar flexors [quotient from absolute force divided by muscle mass (N/g)] was calculated, and glycogen content and morphometric data of the investigated muscles were estimated. Regional blood flow of hindlimb muscles was similar in NW (6 +/- 2 ml. min(-1). 100 g(-1)) and IUGR piglets (8 +/- 1 ml. min(-1). 100 g(-1)). Isometric muscle contractions induced a marked increase in regional blood flow of 4.1-fold in NW and 5-fold in stimulated hindlimb muscles of IUGR piglets (baseline blood flow). Specific force of NW piglet muscles (5.2 +/- 0.2 N/g) was significantly lower than IUGR piglet muscles (6.1 +/- 0.6 N/g; P < 0.05). Isometric muscle contractions (NW: 32.7 +/- 4.7 N; IUGR: 21.7 +/- 4.0 N) resulted in a higher rate of force decrease in the calf muscles of NW animals compared with IUGR piglets (8 +/- 2 vs. 3 +/- 1%; P < 0. 01). Functional restoration of contractile performance after hindlimb recirculation was nearly complete in IUGR piglets (98 +/- 1%), whereas in NW piglets a deficit of 9 +/- 3% was found (P < 0. 01). Muscle fiber type estimation revealed an increased proportion of type I fibers in flexor digitalis superficialis and gastrocnemius medialis in IUGR piglets (P < 0.05). These data clearly indicate that contractile function is accelerated in newborn IUGR piglets.

Animals↗

PubMed2000

[Standardized documentation system for the complementary sector of psychiatric care. Development and trial in Saxony].

The necessity for a standardized documentation system for the complementary sector of psychiatric care is pointed out, and the goals and requirements to be met are debated. The test-version of such a documentation system (abbrev. BADO-K) is shown. It consists of modules for the assessment of client-centered data, and for the documentation of the treatment process in various facilities. Furthermore, a module of questionnaires and instruments for assessing outcome variables (e.g. quality of life) is integrated. The principles for using the paper-pencil-version and the EDP-version are outlined and discussed with regard to the legal regulations concerning the protection of personal data. Finally, possibilities and limitations of the presented documentation system are discussed. It is argued that the BADO-K is an useful instrument for evaluating the process and outcome of community psychiatric care.

Community Mental Health Services↗

PubMed1999

Effects of dietary fat type, pentosan level and xylanase supplementation on digestibility of nutrients and metabolizability of energy in male broilers.

A complete two by two by four factorial design was used to examine the main effects of dietary fat type (10% soya oil or 10% beef tallow), xylanase supplementation (with or without Avizyme 1300 at 1 g/kg diet) and pentosan level (7.7 g/kg, 11.0 g/kg, 14.3 g/kg and 17.6 g/kg soluble pentosans, respectively, by varying wheat/rye proportions) as well as their interactions on intestinal chyme conditions, nutrient digestibility and nutrient utilization in male broilers. Nutrient digestibilities for the total digestive tract and at various sites of small intestine were measured during the period from day 18 to 20 of age and at day 21 of age, respectively, using a marker technique. Jejunal and ileal supernatant viscosity increased in an exponential manner as dietary pentosan concentration was increased. This increase was more pronounced in tallow fed birds but was also found in enzyme treated groups albeit at a much lower level. Xylanase activity was still detectable in the ileum of birds fed enzyme supplemented diets but its activity was found to decrease as dietary pentosan content increased. Digestibility of crude protein and that of some amino acids at the terminal ileum was decreased as dietary pentosan content was increased and significantly improved by xylanase addition. No fat effect and no interactions were detected at this site. In contrast, measurements made over the whole gastrointestinal tract showed significantly lower protein and amino acid digestibility values for tallow fed birds, and significant higher enzyme effects especially in diets with higher pentosan concentrations. Nitrogen-corrected apparent metabolizable energy (AMEN) content and net protein utilization decreased with increasing dietary pentosan content and were significantly improved by xylanase addition and were lower in tallow fed birds. Again, xylanase effects were found to be more pronounced for tallow fed birds and at higher pentosan concentrations.

Amino Acids↗

PubMed1999

Inadequacy of the current WHO re-treatment regimen in a central Siberian prison: treatment failure and MDR-TB.

Multidrug-resistant tuberculosis (MDR-TB) threatens the progress of global control efforts. Prisons represent a high risk setting for development and transmission of MDR-TB. In a Siberian TB referral prison (Kemerovo region), the treatment failure rate is 35% (June 1996-March 1997), despite implementation of a strict DOTS program and use of the World Health Organization Category 2 re-treatment regimen for all new cases. Among 164 patients (December 1997-March 1998), initial resistance to isoniazid and rifampin is 22.6%. Such a rate is a warning call to reconsider prison control strategies, and importantly, to address the treatment regimens necessary to combat an institutional epidemic of MDR-TB.

Antitubercular Agents↗

PubMed1999

[Development of a standardized documentation system for outpatient non-hospital based psychiatric care].

An instrument documenting the care process in in-patient psychiatric services within the German mental health care system has been developed (BADO). This paper reports on the development of a documentation system for all non-hospital based mental health services (day centres, community mental health centres, supported accommodation, work rehabilitation services for general adult psychiatric patients and people with substance misuse). The development process and the instrument (PC and paper and pencil version) are described. The documentation system (BADO-K) could be an important prerequisite for quality assurance in non-hospital based mental health care, and its structure ensures compatibility with the corresponding hospital-based documentation system.

Adult↗

PubMed1998

Pain treatment of fibromyalgia by acupuncture.

The lack of objective parameters makes the measurement of pain and the efficacy of pain treatment in patients with chronic pain very difficult. We performed acupuncture therapy in fibromyalgia patients and established a combination of methods to objectify pain measurement before and after therapy. The parameters corresponded to patients' self-report. Twenty-nine fibromyalgia patients as defined by ACR-criteria (25 women, 4 men) with a mean age of 48.2 +/- 2.0 years and a mean disease duration of 6.1 +/- 1.0 years participated in the study. Pain levels and positive tender points were assessed using the visual analogue scale (VAS, i.e., range 0-100 mm) and dolorimetry. Serotonin and substance P levels in serum and the serotonin concentration in platelets were measured concomitantly. During acupuncture therapy no analgesic medication was allowed. The VAS scores decreased from 64.0 +/- 3.4 mm before therapy to 34.5 +/- 4.3 mm after therapy (P < 0.001). Dolorimetry revealed a decreased number of tender points after therapy from 16.0 +/- 0.6 to 11.8 +/- 1.0, P < 0.01. Serotonin levels decreased from 715.8 +/- 225.8 micrograms/10(12) platelets to 352.4 +/- 47.9 micrograms/10(12) platelets (P < 0.01), whereas the serum concentration increased from 134.0 +/- 14.3 ng/ml to 171.2 +/- 14.6 ng/ml (P < 0.01). Substance P levels in serum increased from 43.4 +/- 3.5 pg/ml to 66.9 +/- 8.8 pg/ml (P < 0.01). Acupuncture treatment of patients with fibromyalgia was associated with decreased pain levels and fewer positive tender points as measured by VAS and dolorimetry. This was accompanied by decreased serotonin concentration in platelets and an increase of serotonin and substance P levels in serum. These results suggest that acupuncture therapy is associated with changes in the concentrations of pain-modulating substances in serum. The preliminary results are objective parameters for acupuncture efficacy in patients with fibromyalgia.

Acupuncture Therapy↗

PubMed1998

Cardiovascular function and brain metabolites in normal weight and intrauterine growth restricted newborn piglets--effect of mild hypoxia.

In order to clarify the influence of intrauterine growth restriction on systemic hemodynamics, catecholamine response, and regional distribution of brain energy metabolites per se and during mild hypoxic episodes a study was performed in thirty newborns with a well-characterized state of intrauterine and intra-natal development. Thirty animals were divided into fifteen normal weight piglets (NW) and fifteen intrauterine growth restricted (IUGR) piglets according to their birth weight. Category "NW" covered animals with a birth weight of > 40th percentile; IUGR category covered animals with a birth weight of > 5th and < 10th percentiles. Animals were anesthetized with halothane in 70% nitrous oxide and 30% oxygen and after immobilization artificially ventilated. The acid-base balance and blood gas values at baseline conditions were similar within the different groups investigated and consistent with other data obtained from anesthetized and artificially ventilated newborn piglets. Mild hypoxic hypoxia which was induced by lowering the FiO2 from 0.35 to 0.15 resulted in reduced arterial pO2 (NW: from 115 +/- 37 mmHg to 39 +/- 7 mmHg; IUGR: from 117 +/- 23 mmHg to 39 +/- 3 mmHg; p < 0.05), but arterial pH and pCO2 remained unchanged. Under baseline conditions arterial blood pressure, cardiac output, and myocardial contractility, expressed as dp/dt(max) and plasma catecholamine values were similar in all groups studied. Heart rate was slightly increased in IUGR (p < 0.05). Mild hypoxia led to a strong increase of myocardial contractility in NW as well as IUGR piglets to 2.4 and 2.7 fold and remained increased during recovery (p < 0.05). Moreover, total peripheral resistance was enhanced at the end of recovery period in IUGR animals (p < 0.05). There was a significant increase of epinephrine (E) in NW animals in comparison to sham-operated animals (p < 0.05). Interestingly, during reoxygenation the further increase in E and norepinephrine (NE) levels were enhanced in the animals which suffered from mild hypoxia (p < 0.05). Regional distribution of brain tissue metabolites was partly affected by intrauterine growth restriction. In particular, brain tissue glucose content was strongly reduced by 65 to 72 per cent in all brain regions investigated. Mild hypoxia led to an increase of about 30 percent in NW animals (p < 0.05). In IUGR piglets the percentage increase of brain glucose content was on an average more pronounced but with considerably higher variance. Also, a strong increase of brain lactate content appeared here (p < 0.05). In contrast, brain tissue ATP was quite similar in all groups studied, but brain creatine phosphate was significantly reduced in some forebrain structures of IUGR piglets after mild hypoxia (figure 2, p < 0.05). In summary, this investigation provides information on cardiovascular functions and brain metabolites of normal weight and naturally occurring growth restricted newborn piglets. Mild hypoxemia was well-tolerated from both animal groups. It is suggested that lactate may play a significant role as a source for brain energy production in the newborn IUGR piglets.

Animals↗

PubMed1997

Changed systemic and cerebral hemodynamics and oxygen supply due to gradual hemorrhagic hypotension induced by an external PID-controller in newborn swine.

An experimental design including an external closed-loop PID-(proportional-integral-differential-)controller is presented which enables the induction of gradual hemorrhagic hypotension at different stages of blood flow reduction up to stages of critically disturbed systemic and regional hemodynamics and oxygen supply. For this purpose nine newborn piglets (12-26 hours old, body weight 1626+/-160 g) were anesthetized and artificially ventilated. Gradual hemorrhagic hypotension was induced at four different steady state stages (stage 1 = 60 mmHg; stage 2 = 50 mmHg; stage 3 = 40 mmHg; stage 4 = 35 mmHg) every 30 minutes by gradual blood withdrawal using external PID controller equipment. Cardiac output and brain regional blood flows were measured by the colored microsphere technique. Systemic and brain regional hemodynamics and O2 supply, metabolic parameters and blood catecholamine concentrations were obtained under baseline conditions and at every 25th minute of the four different steady state stages. About 35 percent of the calculated total blood volume (cTBV) was withdrawn in order to reach the first stage of hemorrhagic hypotension. Further blood withdrawal of about 10 percent of the cTBV, about 5 percent of the cTBV, and about 3 percent of the cTBV were necessary to reach the other respective hypotensive stages. Gradual hemorrhagic hypotension led to an increasing reduction of the cardiac output at every hypotensive stage up to about 20 percent of the baseline value (p<0.05). This was accompanied by a concomitant increase of the total peripheral resistance to about 2.5 fold (p<0.05) and a huge increase in the blood catecholamine concentrations (epinephrine: about 64 fold; norepinephrine: about 35 fold). The induced redistribution of the circulating blood volume was shunted to the vital organs. Therefore, brain cortical blood flow was slightly increased at stage 1 and stage 2. A significant reduction of rCBF did not occur until stage 4 (p<0.05). Regional cerebrovascular resistance was concomitantly reduced at stage 1 and stage 2 (p<0.05) and thereafter again slightly elevated. Brain cortical oxygen consumption was maintained up to stage 2, reduced by about 20% at the next stage of hemorrhagic hypotension (p<0.05) and reached the lowest level of about 50% from baseline at stage 4 (p<0.05). Excellent accuracy and stability was shown at each stage for the external PID controller equipment, so that each given setpoint of the instantaneous mean arterial blood pressure was reached and stabilized even at the lowest hypotensive stage (stage 1: 59.53+/-0.23; stage 2: 50.03+/-0.56; stage 3: 39.18+/-1.75; stage 4: 35.28+/-0.45 mmHg (mean+/-SD)). We conclude that the experimental design presented, with an external PID controller to induce gradual hemorrhagic hypotension in newborn piglets is sufficient for producing functional states with changed systemic and cerebral features with high stability and accuracy, enabling a systematic study of disturbed regional hemodynamics and energy metabolism under steady state conditions even under critically changed states of the systemic cardiovascular regulation.

Animals↗

PubMed1997

An investigation into the variability of extract viscosity of wheat-relationship with the content of non-starch-polysaccharide fractions and metabolisable energy for broiler chickens.

The in vitro extract-viscosity and the content of non-starch-polysaccharides were investigated in 34 defined wheat varieties grown at 5 locations each. Both, wheat genotype as well as growing location clearly influenced the viscosity of soluble extract from wheat. Furthermore, the content of non-starch-polysaccharides (soluble/total) and pentosans (soluble/total) were determined in 13 wheat varieties each grown at two locations. Soluble pentosan contents were highly positively correlated with extract viscosity of wheat at the locations Hayn (r = 0.86) and Biendorf (r = 0.90). The classical apparent metabolisable energy of 5 wheat samples having different extract viscosities was assessed. The AMEN values ranged from 14.0 to 14.6 MJ/kg DM and were significant negatively correlated to content of soluble arabinoxylans (r = 0.67) and to the extract viscosity (r = 0.83). Furthermore, the viscosity of jejunal (4.0 to 22.8 mPas) and ileal (13.1 to 78.0 mPas) digesta exhibited a clear relationship with soluble pentosan contents and extract viscosity. Under the conditions applied in this study the technique of extract viscosity measurement can predict the AME.

Analysis of Variance↗

PubMed1996

Proton dosimetry intercomparison.

BACKGROUND AND PURPOSE: Methods for determining absorbed dose in clinical proton beams are based on dosimetry protocols provided by the AAPM and the ECHED. Both groups recommend the use of air-filled ionization chambers calibrated in terms of exposure or air kerma in a 60Co beam when a calorimeter or Faraday cup dosimeter is not available. The set of input data used in the AAPM and the ECHED protocols, especially proton stopping powers and w-value is different. In order to verify inter-institutional uniformity of proton beam calibration, the AAPM and the ECHED recommend periodic dosimetry intercomparisons. In this paper we report the results of an international proton dosimetry intercomparison which was held at Loma Linda University Medical Center. The goal of the intercomparison was two-fold: first, to estimate the consistency of absorbed dose delivered to patients among the participating facilities, and second, to evaluate the differences in absorbed dose determination due to differences in 60Co-based ionization chamber calibration protocols. MATERIALS AND METHODS: Thirteen institutions participated in an international proton dosimetry intercomparison. The measurements were performed in a 15-cm square field at a depth of 10 cm in both an unmodulated beam (nominal accelerator energy of 250 MeV) and a 6-cm modulated beam (nominal accelerator energy of 155 MeV), and also in a circular field of diameter 2.6 cm at a depth of 1.14 cm in a beam with 2.4 cm modulation (nominal accelerator energy of 100 MeV). RESULTS: The results of the intercomparison have shown that using ionization chambers with 60Co calibration factors traceable to standard laboratories, and institution-specific conversion factors and dose protocols, the absorbed dose specified to the patient would fall within 3% of the mean value. A single measurement using an ionization chamber with a proton chamber factor determined with a Faraday cup calibration differed from the mean by 8%. CONCLUSION: The adoption of a single ionization chamber dosimetry protocol and uniform conversion factors will establish agreement on proton absorbed dose to approximately 1.5%, consistent with that which has been observed in high-energy photon and electron dosimetry.

Calibration↗

PubMed1996

Colored microsphere technique as a new method for quantitative-multiple estimation of regional hepatic and portal blood flow.

A new method for multiple, quantitative estimation of regional splanchnic blood flow is presented which overcomes all the limitations of the radionuclide microsphere technique. By direct comparison of two methods, i.e., simultaneous blood flow measurement with radionuclide-labeled and colored microspheres, it was shown that the quality of flow measure was quite similar. Simultaneous measurement using paired radionuclide-labeled microspheres yielded an excellent correlation between both values of r = 0.997, a variability of 4.58 +/- 3.84% and a SEE-value of 0.167 ml/g/min. The colored microsphere technique produced corresponding values with r = 0.998, a variability of 5.94 +/- 7.80% and a SEE-value of 0.212 ml/g/min (n.s.). This is also shown for five different abdominal organs and tissues with quite different flow rates under normal physiological conditions. Thus, the colored microsphere technique is a suitable experimental method for making multiple and quantitative measures of the nutritive blood flow through splanchnic organs and tissues and yields values of arterial blood inflow into the liver and into the circulatory bed which is drained by the portal vein.

Animals↗

PubMed1995

Brain peroxidative and glutathione status after moderate hypoxia in normal weight and intra-uterine growth-restricted newborn piglets.

In order to investigate the pathogenetic factors causing the relatively frequent occurrence of brain injury in intrauterine growth-restricted newborns, lipid peroxidation products (TBAR), glutathione (GSH, GSSG) and in vitro production of reactive oxygen species (chemiluminescence, stimulated lipid peroxidation, H2O2 formation) were studied in the brain of normal weight (NW) and intra-uterine growth-restricted newborn piglets (IUGR) after 1 hour of hypoxia (FiO2 11%) and 90 min reoxygenation. Cardiocirculatory parameters and catecholamine release into the blood were also measured. In the cerebellum, higher GSH content, but also higher in vitro production of lucigenin amplified chemiluminescence were found in comparison to other brain regions, independent of growth restriction and hypoxia. Moderate hypoxia without acidosis and hypercapnia resulted in GSH depletion especially in the brain of IUGR, but no changes in GSSG concentrations were measured. Though TBAR decreased after hypoxia/reoxygenation, in some brain areas of IUGR higher TBAR values were found in comparison to NW. H2O2 formation, stimulated lipid peroxidation and lucigenin and luminol amplified chemiluminescence in the 9000 x/g supernatant of brain tissue did not reveal special response of IUGR to hypoxia/reoxygenation. Hypoxia-induced circulatory centralisation due to increased release of catecholamines into the plasma prevented oxygen deficiency also in the brain of IUGR. The role of brain monoamine metabolism in the production of reactive oxygen species, followed by greater GSH depletion and higher in vivo formation of lipid peroxides in IUGR is discussed.

Animals↗

PubMed1993