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Biomedical subjects

K Jung

Publications and source records attributed to K Jung.

At least 37 records · Page 2Linked to original sources
PubMed2004

Surface acoustic waves for the characterization of BN-coated fibres observed by Brillouin light scattering.

The observation of acoustic phonons located at the surface of uncoated fibres or guided in thin films deposited on fibres by Brillouin light scattering spectroscopy (BLS) is reported. The BLS technique is non-destructive and non-intrusive and is well applicable to non-planar sample geometries. Investigations were carried out on bundles of commercially available carbon fibres, in which a single fibre was 5 microm in diameter. With regard to the detected surface acoustic excitations, each fibre can be considered as an infinite halfspace owing to the large ratio of fibre diameter to wavelength. The shear modulus, which is highly relevant for the intended technical application, was determined by measurement of the Rayleigh mode phase velocity of the uncoated fibres. These fibre bundles were coated with boron nitride (BN) in a continuously driven thermal chemical vapour deposition (CVD) process using trimethyl borate and ammonia as precursors. In comparison to carbon, BN is expected to improve the mechanical properties of fibre-reinforced composites such as fracture toughness at high temperatures. The measured velocity dispersion of the Rayleigh mode of this film-on-substrate system permitted the comparison of the shear stiffness of the carbon fibre and of the BN film material. The results evidence the desired effect of a distinct stiffness reduction of the coated fibre relative to the uncoated fibre in the near-surface region. Additional information can be obtained on the homogeneity of the deposition across the whole fibre bundle.

Journal Article↗
PubMed2004

Analysis of two-component signal transduction by mathematical modeling using the KdpD/KdpE system of Escherichia coli.

A mathematical model for the KdpD/KdpE two-component system is presented and its dynamical behavior is analyzed. KdpD and KdpE regulate expression of the kdpFABC operon encoding the high affinity K+ uptake system KdpFABC of Escherichia coli. The model is validated in a two step procedure: (i) the elements of the signal transduction part are reconstructed in vitro. Experiments with the purified sensor kinase and response regulator in presence or absence of DNA fragments comprising the response regulator binding-site are performed. (ii) The mRNA and molecule number of KdpFABC are determined in vivo at various extracellular K+ concentrations. Based on the identified parameters for the in vitro system it is shown, that different time hierarchies appear which are used for model reduction. Then the model is transformed in such a way that a singular perturbation problem is formulated. The analysis of the in vivo system shows that the model can be separated into two parts (submodels which are called functional units) that are connected only in a unidirectional way. Hereby one submodel represents signal transduction while the second submodel describes the gene expression.

Base Sequence↗
PubMed2004

In-situ hybridization for the detection of Haemophilus parasuis in naturally infected pigs.

Detection of Haemophilus parasuis in naturally infected pigs was studied by in-situ hybridization with a non-radioactive digoxigenin-labelled DNA probe. Twenty pigs were selected on the basis of bacterial isolation and histopathological lesions. An 821 base pair DNA probe from the 16S small subunit ribosomal RNA (rRNA) was generated by the polymerase chain reaction. Hybridization signals were detected in formalin-fixed, paraffin-wax-embedded tissues (lung, heart, spleen and liver). Identification of the cell types containing H. parasuis was occasionally difficult, but examination of adjacent sections stained with haematoxylin and eosin confirmed that positive cells resembled either macrophages (large oval nuclei and abundant cytoplasm) or neutrophils (bilobed nuclei). In-situ hybridization would appear to be a valuable tool for the diagnosis of H. parasuis infection.

Animals↗
PubMed2004

No apparent association between periocular and ocular microcolonization and the degree of inflammation in patients with atopic keratoconjunctivitis.

BACKGROUND: The cause of the chronic inflammation in atopic keratoconjunctivitis (AKC), the ocular manifestation of atopic eczema/dermatitis syndrome, is largely unknown. OBJECTIVE: To investigate the possibility that microorganisms may be important in the inflammatory activity in AKC. METHODS: Fifteen patients with AKC participated in the study. The presence of aerobic bacteria and fungi was related to the severity of clinical signs, the numbers of inflammatory cells in tears and conjunctival biopsies, and the concentration of various cytokines in tears. In addition, serological evidence for IgE sensitization to Staphylococcus aureus B antigen and Malassezia sympodialis antigen was investigated. Twelve healthy subjects were included for control purposes. RESULTS: The patients exhibited moderate clinical signs of AKC. No relation was found between the severity of AKC and the presence of microorganisms, despite the fact that S. aureus was frequently isolated. AKC patients showed significantly higher levels of IFN-gamma, TNF-alpha (tumour necrosis factor-alpha), IL-2, IL-4, IL-5 and IL-10 than controls. An association was found between conjunctival signs and the levels of all cytokines except IL-5. CONCLUSION: We found no evidence to suggest that periocular and ocular microcolonization are related to inflammatory parameters in AKC. However, confirmation of the present results in a longitudinal study with repeated clinical examinations and samplings in the same individual is required before the contribution of S. aureus to on-going inflammation in AKC can be dismissed.

Adult↗
PubMed2004

Antiviral effect of Saccharomyces cerevisiae beta-glucan to swine influenza virus by increased production of interferon-gamma and nitric oxide.

The aim of these experiments was to investigate the potential antiviral effect of Saccharomyces cerevisiae beta-glucan on the pneumonia induced by swine influenza virus (SIV). Forty colostrum-deprived 5-day-old piglets were randomly divided into four groups of 10. The 20 pigs in groups 1 and 2 were administered Saccharomyces cerevisiae beta-glucan orally (50 mg/day/pig; En-Bio Technology Co., Ltd) for 3 days before SIV infection and those in groups 3 and 4 were given culture medium/diluent alone. Groups 1 and 3 were inoculated intranasally with 3 ml of tissue culture fluid containing 2 x 10(6) tissue culture infective doses 50% (TCID(50))/ml of SIV and those in groups 2 and 4 were exposed in the same manner to uninfected cell culture supernatant. The microscopic lung lesions induced by SIV infection (group 1 pigs) were significantly more severe than those induced by infection in animals pre-administered beta-glucan (group 3) (P < 0.05). Significantly more SIV nucleic acid was detected in the lungs of pigs experimentally infected with SIV only (group 1) at 5, 7 and 10 days post-inoculation (dpi) compared with lungs from pigs pre-administered beta-glucan and infected with SIV (group 3) (P < 0.05). The concentrations of interferon-gamma (IFN-gamma) and nitric oxide (NO) in bronchoalveolar lavage fluid from pigs pre-administered beta-glucan and infected with SIV (group 3) were significantly higher than for any other group at 7 and 10 dpi for IFN-gamma, and at 5, 7 and 10 dpi for NO (P < 0.05). Saccharomyces cerevisiae beta-glucan reduced the pulmonary lesion score and viral replication rate in SIV-infected pigs. These findings support the potential application of beta-glucan as prophylactic/treatment agent in influenza virus infection.

Administration, Oral↗
PubMed2004

Genotypic prevalence of the adhesin involved in diffuse adherence in Escherichia coli isolates in pre-weaned pigs with diarrhoea in Korea.

A total of 1002 Escherichia coli strains isolated from pre-weaned pigs with diarrhoea on 1114 swine farms were screened for the presence of the adhesin involved in diffuse adherence (AIDA) gene by polymerase chain reaction (PCR). Escherichia coli isolates that carried AIDA genes were also tested by PCR for the detection of five fimbriae (F4, F5, F6, F18 and F41), heat-stable (STa, STb) and heat-labile (LT) enterotoxin, enteroaggregative E. coli heat-stable enterotoxin 1 (EAST1), and Shiga toxin 2 oedema disease (Stx2e) genes. Twenty-three (2.3%) of the 1002 E. coli isolates carried the gene for AIDA. Among 23 isolates shown to carry genes for AIDA, three carried the AIDA gene as the only shown virulence factor. Other isolates carried other virulence factor genes in addition to AIDA. Four isolates carried genes for at least one of the fimbrial adhesins and enterotoxins. Sixteen isolates carried genes for enterotoxins only. The AIDA may represent an additional virulence determinant in pre-weaned pigs with diarrhoea.

Adhesins, Escherichia coli↗
PubMed2003

Tumor type M2 pyruvate kinase expression in metastatic renal cell carcinoma.

The M2 isoenzyme of pyruvate kinase (M2-PK) is specifically expressed in tumor cells (TuM2-PK) and has been detected in the peripheral blood of patients with renal cell carcinoma (RCC). TuM2-PK is not useful as a biological marker in localized RCC. We analysed TuM2-PK in 68 patients with metastatic RCC after initial surgery and prior to or during chemoimmunotherapy of metastases. In 50 patients, the levels of TuM2-PK were measured during chemoimmunotherapy with interleukin-2, interferon-alpha2a and 5-fluorouracil for up to 8 months and were correlated to response as assessed by radiological imaging techniques. TuM2-PK was quantified with a commercially available enzyme linked immunosorbent assay kit using a cut off of 15 kU/l. In 48 of 68 patients (71%), TuM2-PK was elevated above the cut-off. TuM2-PK was significantly higher in G3 tumors than in G2 tumors. In 34 of 50 patients (68%) undergoing chemoimmunotherapy, a positive correlation between TuM2-PK values and response to treatment was observed. Based on these data, we would not recommend the routine clinical use of TuM2-PK in metastatic RCC at this point.

Adult↗
PubMed2003

Aquatic hyphomycetes in polluted groundwater habitats of central Germany.

Polluted groundwater wells located in a former copper shale mining district (11 sites; Mansfelder Land, Central Germany) and in meadows of the Mulde and Elbe rivers (2 sites) were assessed for occurrence and species richness of aquatic hyphomycetes. Water temperatures at all sites were relatively low and fluctuated less than in surface waters. Oxygen concentrations were always below saturation, whereas sulfate, nitrate, and phosphate levels reached extremely high values in several of the wells. Relatively high levels of Pb, Mn, and Fe were found in some of the wells, but overall few concentrations of individual metals and metalloids exceeded European guidelines for drinking water. Pollen tube growth inhibition, used to assess cytotoxicity of the water, ranged between 4 and 50%. Between 1 and 10 distinct species of aquatic hyphomycetes colonized sterile Alnus glutinosa leaves exposed at the Mansfelder Land sites; for the meadow sites, 8-20 species were found. Heliscus lugdunensis and Anguillospora sp. were the two most widespread species. Fungal colonization occurred much more slowly than in surface water, as demonstrated by scanning electron microscopy and the release of conidia from recovered leaves. The conidial output from exposed alder leaves ranged from 0.2 to 95 conidia mg (-1) dry mass, corresponding to 10% of the values for contaminated surface waters in the same region. Overall, groundwater appears to be a marginal habitat for aquatic hyphomycetes, but may nevertheless play a vital role as long-term reservoir facilitating rapid recolonization following a collapse in fungal communities in surface waters.

Copper↗
PubMed2003

Tracking variations in airway caliber by using total respiratory vs. airway resistance in healthy and asthmatic subjects.

An index of airway caliber can be tracked in near-real time by measuring airway resistance (Raw) as indicated by lung resistance at 8 Hz. These measurements require the placing of an esophageal balloon. The objective of this study was to establish whether total respiratory system resistance (Rrs) could be used rather than Raw to track airway caliber, thereby not requiring an esophageal balloon. Rrs includes the resistance of the chest wall (Rcw). We used a recursive least squares approach to track Raw and Rrs at 8 Hz in seven healthy and seven asthmatic subjects during tidal breathing and a deep inspiration (DI). In both subject groups, Rrs was significantly higher than Raw during tidal breathing at baseline and postchallenge. However, at total lung capacity, Raw and Rrs became equivalent. Measured with this approach, Rcw appears volume dependent, having a magnitude of 0.5-1.0 cmH2O. l-1. s during tidal breathing and decreasing to zero at total lung capacity. When resistances are converted to an effective diameter, Rrs data overestimate the increase in diameter during a DI. Simulation studies suggest that the decrease in apparent Rcw during a DI is a consequence of airway opening flow underestimating chest wall flow at increased lung volume. We conclude that the volume dependence of Rcw can bias the presumed net change in airway caliber during tidal breathing and a DI but would not distort assessment of maximum airway dilation.

Adult↗
PubMed2003

Quantitative analysis of macrophage inhibitory cytokine-1 (MIC-1) gene expression in human prostatic tissues.

Macrophage inhibitory cytokine-1 (MIC-1) gene is a member of transforming growth factor-beta superfamily and was reported to be highly overexpressed in human prostate cancer using microarray technology. The aim of this study was to evaluate the quantitative expression of MIC-1 in malignant and benign prostate tissues and to associate expression levels with clinicopathological parameters of prostate cancer. Matched (paired) prostatic tissue samples from the cancerous and noncancerous parts of the same prostates were obtained from 66 patients who underwent radical prostatectomy. Quantitative RT-PCR was performed using SYBR Green I on the Roche LightCycler system. Macrophage inhibitory cytokine-1 gene overexpression in cancerous tissues was observed in 88% of cases, compared to noncancerous tissues (P<0.001). The expression level of MIC-1 in cancerous tissues was significantly higher than in noncancerous tissue (P<0.001). Higher expression of MIC-1 gene was significantly associated with higher Gleason score (P=0.004). The expression of the MIC-1 gene in prostate cancer is significantly higher than in noncancerous tissues, especially in more aggressive forms of the disease (Gleason score>5). This is in contrast to prostate-specific antigen that is downregulated in higher-grade tumours. The upregulation of MIC-1 in prostate cancer and in advanced and more aggressive prostatic tumours suggests that MIC-1 protein should be evaluated as a potential diagnostic and prognostic biomarker.

Aged↗
PubMed2003

[An artificial neural network as a tool in risk evaluation of prostate cancer. Indication for biopsy with the PSA range of 2-20 microg/l].

In this prospective study covering 5.5 years we evaluated the diagnostic power of an artificial neural network (ANN) based on PSA, %fPSA, and clinical data in the PSA range 2-20 microg/l as prostate biopsy indicator. A total of 944 patients with prostate cancer or benign hyperplasia (BPH) were analyzed. The calculation of the individual patient's risk before prostate biopsy was performed at the 90% and 95% specificity and sensitivity levels within the PSA ranges 2-4, 4.1-10, and 10.1-20 microg/l. For the low PSA range 2-4 microg/l, we recommend a first time biopsy at an ANN specificity level of 95%. For PSA range 4.1-10 microg/l, we recommend a first time biopsy at an ANN sensitivity level of 95%. A rebiopsy at the PSA range 10.1-20 micro g/l should be performed based on a 95% sensitivity level. The use of an ANN at PSA 2-20 microg/l enhances the specificity and sensitivity of %fPSA by 9-39%. The application of an ANN based on %fPSA and clinical data improves the diagnostic performance compared to %fPSA only.

Adult↗
PubMed2003

[Health-related quality of life after heart transplantation].

BACKGROUND: Quality of life late after heart transplantation is reported to be comparable with that of the general population. However, peak exercise capacity remained approximately 60% of what was normal between 1 and 10 years after transplantation. The gap between patients' good quality of life and their impaired exercise tolerance is not yet explained. The purpose of our study was to examine the relation between quality of life and exercise- related variables in heart transplant recipients (HTR). Then, the results of these examinations were compared with those of patients having congestive heart failure (CHF), with the use of controls (C), respectively. METHODS: (Mean values+/-SD) 29 HTR 4.4 +/- 2.1 years after transplantation, 29 CHF (NYHA II n = 22, III n = 7) and 29 C (age 54 +/- 9, 61 +/- 10, 56 +/- 10 years, body mass index 28 +/- 3, 29 +/- 5, 28 +/- 4 kg x m(-2), body fat 25 +/- 4, 27 +/- 6, 26 +/- 5%, respectively) performed cardiopulmonary exercise testing and were interviewed with the standardized German "Quality of life profile for chronic diseases" questionnaire. RESULTS: Peak oxygen consumption was impaired in HTR and in CHF compared with C (19.0 +/- 4.5, 18.6 +/- 4.3, and 30.2 +/- 6.6 ml x min x kg(-1), respectively; p < 0.01 vs. C each). HTR and CHF patients' quality of life in the physical scores were both impaired (p < 0.05 or p < 0.01 vs. C, respectively), but HTRs have reported better scores than CHF (p < 0.05). In the psychological role, CHF was impaired against C (p < 0.05), and HTR scores were comparable with C. In social functioning HTR and CHF patients both showed reduced quality of life dimensions. The Pearson correlation analysis showed that quality of life in physical functioning was related to peak oxygen consumption (p < 0.001) and percentage of predicted workload (p < 0.001). Quality of life in the social and psychological domains showed no association to exercise-related values. CONCLUSIONS: In HTR and in CHF, exercise testing variables were dominant predictors among the physical scales in quality of life, but not among social or psychological scales. Therefore, even late after heart transplantation, improving physical capacity should be a therapeutic goal with the intention of further increasing the quality of life.

Aged↗
PubMed2003

[Phase III rehabilitation after heart transplantation].

INTRODUCTION: Longterm treatment after heart transplantation (HTX) improves survival, although the quality of life and exercise tolerance decreased continuously between one and ten years after transplantation. The role of physical exercise and psychological support in longterm treatment after HTX has not been determined. We analyzed the effects of a one year outpatient rehabilitation program in combination with a home based, computer assisted training program on exercise capacity, coronary risk factors and quality of life. METHODS: 20 heart transplant recipients in an intervention group and 12 patients after HTX in a control group participated in the study (IG (CG); 5.1+/-2.2 (4.5+/-2.3) years after HTX; age: 55+/-7 (54+/-8) years; body mass index: 28.3+/-1.0 (28.7+/-0.9) kg.m(-2)). Before and after the intervention, maximum and constant load exercise capacity, and self-reported quality of life were evaluated. The 12 month intervention period included 10 days of exercise testing as well as medical and psychological support. Furthermore, the IG group performed a computer-assisted and controlled home ergometer training every second day. RESULTS: After one year with 114+/-18 exercise training sessions, maximum oxygen consumption increased in the IG from 18.8+/-4.2 to 20.1+/-4.2 ml.min(-1).kg(-1) (p<0.05; CG 19.3+/- 4.5 to 18.5+/-2.8 ml.min(- 1).kg(-1); p<0.01 IG vs CG). In the IG, lower back pain, body fat, and blood pressure were all reduced, while the self-reported quality of life, endurance exercise capacity and HDL cholesterol were increased. No significant changes occurred in the control group. CONCLUSIONS: When initiated years after heart transplantation, longterm rehabilitation reduced coronary risk factors and significantly improved both the subjects' quality of life, as well as a near to normal capacity for physical work.

Ambulatory Care↗
PubMed2003

Sample preparation techniques for the determination of natural 15N/14N variations in amino acids by gas chromatography-combustion-isotope ratio mass spectrometry (GC-C-IRMS).

In order to identify natural nitrogen isotope variations of biologically important amino acids four derivatization reactions (t-butylmethylsilylation, esterification with subsequent trifluoroacetylation, acetylation and pivaloylation) were tested with standard mixtures of 17 proteinogenic amino acids and plant (moss) samples using GC-C-IRMS. The possible fractionation of the nitrogen isotopes, caused for instance by the formation of multiple reaction products, was investigated. For biological samples, the esterification of the amino acids with subsequent trifluoroacetylation is recommended for nitrogen isotope ratio analysis. A sample preparation technique is described for the isotope ratio mass spectrometric analysis of amino acids from the non-protein (NPN) fraction of terrestrial moss. 14N/15N ratios from moss (Scleropodium spec.) samples from different anthropogenically polluted areas were studied with respect to ecotoxicologal bioindication.

Amino Acids↗
PubMed2002

SURF_ER--surface electron spin resonance (ESR) of the surface domain of large objects.

SURF_ER is a method for spectral and spatial electron spin resonance measurements on the surface of large objects which extension is only restricted by the width of the pole gap of the magnet and the homogeneity of the magnetic field and not by the cavity dimensions. The application of several techniques like SURF_ER for spectroscopic measurements, SURF_ERM for spatial scanning and SURF_ERI for spatial measurements of the depth of the surface region are discussed and represented for the skin of a human being as an example.

Animals↗
PubMed2002

The novel synthetic inhibitor of matrix metalloproteinases Ro 28-2653 induces apoptosis in Dunning tumor cells.

The effect of synthetic inhibitors of matrix metalloproteinases (MMP) has been shown against a variety of tumors in preclinical models. Ro 28-2653, a novel synthetic MMP inhibitor, is able to reduce tumor growth in orthotopic prostatic cancer in rats (R3327 Dunning tumor). However, at present this inhibitory mechanism in tumor inhibition in vivo can only be partly explained by the inhibition of the catalytic activity of MMPs overexpressed in cancereous tissue. Using the flow cytometric method, we have investigated the effect of various concentrations of Ro 28-2653 on the Dunning tumor cells with regard to the staining of F-actin and DNA as markers of apoptosis. In combination with fluorescence microscopy we detected the loss of F-actin and the degradation of internucleosomal DNA. This effect of Ro 28-2653 on apoptosis was dose- and time-dependent increasing with concentration between 10 and 100 microg/ml as well as with time of treatment between 24 and 48 h.

Actins↗