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Biomedical subjects

T Klein

Publications and source records attributed to T Klein.

At least 37 records · Page 2Linked to original sources
PubMed2005

Modulation and source of procalcitonin in reduced renal function and renal replacement therapy.

Serum procalcitonin (PCT), an accurate marker of severe infection, is moderately increased in chronic kidney disease (CKD), peritoneal dialysis (PD) and haemodialysis (HD). We studied the extent of PCT elevation and factors accounting for elevated PCT in CKD and dialysis, and whether peripheral blood mononuclear cells (PBMC) contribute to increased PCT. In 37 controls, 281 CKD, 31 PD, and 65 HD patients without infection, PCT was measured and correlated with CKD stage, PD, HD, C-reactive protein (CRP), cardiovascular disease (CVD) and other clinical parameters. PCT release by PBMC from controls, advanced CKD, PD and HD patients (12 subjects each) was measured. PCT increased in parallel to the deterioration of CKD. Oliguria, advanced CKD, PD, HD, CVD and elevated CRP were independently associated with PCT elevation. PCT release from PBMC significantly increased in advanced CKD, PD and HD. PCT release from PBMC correlated closely with the corresponding serum PCT values (r=0.76, P <0.001). In the absence of infection, PCT may increase due to reduced renal elimination and increased synthesis, as due to PBMC. Furthermore, serum PCT could serve as a marker of low-grade inflammation and CVD, which substantially increase mortality in CKD and dialysis.

C-Reactive Protein↗
PubMed2005

Extended family studies for the identification of allogeneic stem cell transplant donors in Jewish and Arabic patients in Israel.

HLA-identified donors are the best source of allogeneic hematopoietic stem cell transplants, and are available in approximately 40% of cases. If no HLA-identical core family member is found, an extended family search may be performed. The aim of the study was to summarize the 10-year (1990-1999) experience of our tertiary care center with extended family donor search. During this period, 356 patients and 2659 of their family members were tissue-typed; 239 patients were Jewish (67%) and 117 were Arabic (33%). An HLA-identical core-family donor was identified for 168 patients (47%): 95 Jewish (40%) and 73 Arabic (62%) (p < 0.0001); 49 patients (14%) had more than one potential donor. An extended family search (grandmother/grandfather, aunts, uncles, etc.) was performed in 38 of the remaining families, which were found to be consanguineous: five Jewish and 33 Arabic. One HLA match was found in the Jewish families (20%) and 21 in the Arabic families (64%). The odds ratio for an Arabic patient to find a donor in the extended family search was 8.75, as opposed to a Jewish patient. Overall, HLA-matched donors were found by core and extended family search for 53% of the patients. The rate for Arabic patients was 80% and for Jewish patients, 40% (p < 0.001). This difference may be explained by the greater number of siblings and higher rate of consanguinity in the Arabic population. In conclusion, an extended family search for potential HLA-matched donors is worthwhile, especially in distinct ethnic populations with high consanguinity, such as Israeli Arabs.

Arabs↗
PubMed2004

Dependence of the superconducting transition temperature on the doping level in single-crystalline diamond films.

Homoepitaxial diamond layers doped with boron in the 10(20)-10(21) cm(-3) range are shown to be type II superconductors with sharp transitions (approximately 0.2 K) at temperatures increasing from 0 to 2.1 K with boron contents. The critical concentration for the onset of superconductivity in those 001-oriented single-crystalline films is about 5-7 10(20) cm(-3). The H-T phase diagram has been obtained from transport and ac-susceptibility measurements down to 300 mK.

Journal Article↗
PubMed2004

[Clinical significance of stress reactivity for frequency of electric shock discharges in patients with implanted cardioverter-defibrillators].

BACKGROUND AND OBJECTIVE: Recent research indicates that discharges of implanted cardioverter-defibrillators (ICD) are triggered by psychosocial stress. This study examined the presence of patterns of psychophysiological stress reactivity in ICD-patients. Further more potential relationship between factors of stress reactivity and the frequency of implantable cardioverter-defibrillators discharges was investigated. PATIENTS AND METHODS: In 46 consecutive patients (38 male, 8 female; age: 26-80 years) with implantable cardioverter-defibrillators the following parameters of physiological reactivity were measured in a standardised experimental stress test: Heart rate, skin conductance, muscle tension and respiratory activity. In a standardised interview anxiety sensitivity, depression, desire for control, stress load, and attitude towards the defibrillator were evaluated and quantified. The relationship between the mentioned parameters were examined with factor analysis to reveal patterns of psychophysiological reactivity. Potential relationship between psychophysiological factors and frequency of shock delivery was verified with linear regression analysis. RESULTS: Factor analysis revealed four independent psychophysiological traits. The factors were named "Play Dead Reflex", "Heart Phobia", "Negativism" and "Irritability". Linear regression model showed significant correlation between "Play Dead Reflex" and discharge frequency. CONCLUSIONS: Results confirm the presence of specific psychophysiological stress reaction patterns in ICD-patients. The stress reaction pattern "Play Dead Reflex" could be discussed as a potential risk factor in developing life-threatening tachyarrhythmias leading to an increase in defibrillator discharges in patients with ICD. This hypothesis should be considered in prospective studies and psychosomatic treatment of concerned patients.

Adult↗
PubMed2004

Anisotropies of the lower and upper critical fields in MgB2 single crystals.

The temperature dependence of the upper (H(c2)) and lower (H(c1)) critical fields has been deduced from Hall probe magnetization measurements of high quality MgB2 single crystals along the two main crystallographic directions. We show that Gamma(H(c2))=H(c2 axially ab)/H(c2 axially c) and Gamma(H(c1))=H(c1 axially c)/H(c1 axially ab) differ significantly at low temperature (being approximately 5 and approximately 1, respectively) and have opposite temperature dependencies. We suggest that MgB2 can be described by a single field dependent anisotropy parameter gamma(H) (=lambda(c)/lambda(ab)=xi(ab)/xi(c)) that increases from Gamma(H(c1)) at low field to Gamma(H(c2)) at high field.

Journal Article↗
PubMed2004

Direct transition from Bose glass to normal state in the (K,Ba)BiO3 superconductor.

The introduction of columnar defects in (K,Ba )Bi O3 single crystals shifts both the irreversibility and thermodynamic transition lines, respectively, deduced from ac susceptibility (and/or transport) and specific heat measurements, upwards. This shift can be attributed to the defect-induced decrease of the difference (Delta F) between the free energies in the superconducting and the normal states, assuming that the position of the superconducting transition is given by the condition absolute value Delta F approximately k(B )T/xi(3 ). This criterion also perfectly reproduces the influence of the angle between the tracks and the external field. This result suggests that no vortex liquid phase exists in this system.

Journal Article↗
PubMed2004

Role of circulating soluble CD40 as an apoptotic marker in liver disease.

OBJECTIVES: To measure levels of soluble CD40, a laboratory marker of apoptosis in patients with liver disease, determine its origin, and correlate the findings with disease activity and histology. DESIGN: Laboratory research study with comparison group. SETTING: Liver Institute, Laboratory of HLA Typing and Histopathology Department, Rabin Medical Center, Israel. SUBJECTS: One hundred ten patients with liver disease and 20 healthy controls. METHODS: Serum samples were collected from all patients; in addition, paired hepatic and portal vein samples were collected from 23 patients, and bile samples from 5 patients. Soluble CD40 was measured with an enzyme-linked immunosorbent assay. Apoptotic cells in liver tissue were identified by morphological criteria and quantified with the TUNEL assay. RESULTS: Soluble CD40 concentration was significantly higher in patients with liver disease than controls (mean 112.9 +/- 197.2 pg/ml vs. 24.2 +/- 9.1 pg/ml, p = 0.0001), with highest levels in the chronic viral hepatitis group (mean 131.7 +/- 137.5 pg/ml, p = 0.0001). Levels of sCD40 were correlated with serum creatinine, alkaline phosphatase, alpha-feto protein, and the apoptotic index. In the 23 paired samples, CD40 level was higher in the hepatic vein (mean 74.9 +/- 114.5 pg/ml) than the portal vein (mean 51.6 +/- 67.9 pg/ml); it was highly detectable in bile (mean 115.6 +/- 119.6 pg/ml, p = 0.0123). Untreated patients with chronic viral hepatitis (B and C) had higher levels (mean 106.2 +/- 76.5 pg/ml) than treated patients (mean 59.3 +/- 68.6 pg/ml, p = 0.049). CONCLUSIONS: Levels of soluble CD40 increase in different types of liver disease. It probably derives from the liver and is secreted into the bile. Levels correlate with the apoptotic index and are affected by antiviral treatment. Soluble CD40 may serve as a serum marker of apoptosis in liver disease.

Apoptosis↗
PubMed2004

Delayed therapy with curative intent in a contemporary prostate cancer watchful-waiting cohort.

OBJECTIVE: To identify predictors of delayed therapy with curative intent, an increasingly common option in contemporary patients with prostate cancer who initially choose watchful waiting. PATIENTS AND METHODS: The characteristics of all patients at one institution and diagnosed with T1-4NXM0 prostate cancer between 1993 and 2000 were prospectively recorded. Factors recorded included: age, tumour stage, histological type, Gleason score, serum prostate specific antigen (PSA) level, prostate volume, PSA density (PSAD), percentage of positive biopsy cores, and the initial treatment selection. Outcomes, including all cancer-directed interventions, all serum PSA values, and initial outcomes of all interventions with curative intent, were determined by review of all medical records and cancer registry data. RESULTS: Of 187 patients on watchful waiting, 175 had stage T1 or T2 cancer and were analysed primarily. Thirty-eight (22%) of these patients received delayed intervention with curative intent (15 radical prostatectomy, 17 external beam radiotherapy, six brachytherapy). Age (P < 0.001) and percentage of positive biopsy cores (P = 0.042) were significant independent predictors of intervention with curative intent. When the PSA doubling time was added to the model it became a significant predictor (P = 0.018), with percentage positive biopsy cores (P = 0.022) and age (P < 0.001). CONCLUSIONS: Therapy with curative intent is common in contemporary patients with prostate cancer who initially choose watchful waiting. Age and percentage positive biopsy cores are independent predictors of such intervention, with PSA doubling time also an independent predictor.

Adenocarcinoma↗
PubMed2004

[Effect of triester glycerol type of plasticizers on release of albumin from biodegradable polymer matrices].

Bovine serum albumin was heterogeneously dispersed in the terpolymer of DL-lactic acid, glycolic acid, and mannitol. The terpolymeric carrier was plasticized by triacetin, tributyrin, or a mixture of triacetin with tricaprylin. Matrices were prepared by mixing a melt of the carrier with the plasticizer and albumin. Liberation was tested in 1/15 mol.l-1 phosphate buffer pH 7.4 and took place in two stages--the burst and the stage of the continual process. The burst represented 30% to 90% of liberated albumin. The second, continual stage began on day 4 of liberation and within ten days maximally 10% of the total amount of albumin was released. The course of liberation was most markedly influenced by the parameters of the oligoester carrier, its molecular weight, and the degree of branching. The total extent of albumin liberation was influenced partly by its irreversible adsorption on the carrier, partly by its polymerization. The extent of adsorption and polymerization of albumin was increased with the molecular weight of the carrier and decreased with the increasing degree of its branching. Albumin liberation was positively influenced by the presence of plasticizers in matrices, triacetin being demonstrated as the best one.

Biodegradation, Environmental↗
PubMed2004

[Liberation of folic acids from composite chitosan films].

Thin films were prepared by the method of evaporation of aqueous solutions of chitosan or its mixtures with poloxamer 407, gelatin, or polyvinyl alcohol. Films of varying thickness were cross-linked with phosphate ions. They contained micronized folic acid in a concentration of 9.1% or 3.2%. Prolonged several hours' liberation of folic acid into isotonic phosphate buffer at pH 5.5, 6.0, and 6.5 was examined. In the initial stage, the mechanism of liberation was governed by diffusion of the dissolved fraction, at higher pH values a higher rate of dissolution of the substance played its role. In some composites, sorption of folic acid to chitosan in an extent dependent on the composition of composites and current acidity of the medium was demonstrated.

Biocompatible Materials↗
PubMed2003

Anisotropic enhancement of superconductivity in heavy-ion irradiated (K, Ba)BiO3.

We have measured the specific heat, resistivity, and ac susceptibility of (K,Ba)BiO3 single crystals before and after introduction of either point or columnar defects by electron (EI) or heavy-ion irradiation (HII). While the magnetic field dependence of these properties remains mainly unaffected by EI, the irreversibility line and the location of the specific heat anomaly are both shifted up in temperature after HII. The shift is apparent only if the magnetic field is applied parallel to the ion tracks. For perpendicularly applied fields, both lines lie at the same field as in the pristine sample. These experiments call the nature of the vortex liquid state into question.

Journal Article↗
PubMed2003

Use of in vitro release of interferon-gamma in the diagnosis of contact allergy to potassium dichromate - a controlled study.

The use of in vitro release of interferon-gamma (IFN-gamma) in the diagnosis of contact allergy to potassium dichromate was studied in 20 patients who had positive patch tests to chromate and in 30 control subjects (10 patients with contact dermatitis, allergic to other allergens, 10 patients with other dermatologic diseases and 10 healthy subjects). The release of IFN-gamma in the supernatants of the peripheral blood lymphocytes was significantly higher in the patients with proven allergy to chromate (P = 0.001). Further studies are needed to determine if IFN-gamma release may serve as an additional diagnostic tool in contact dermatitis.

Adolescent↗
PubMed2003

Circulating soluble cytochrome c in liver disease as a marker of apoptosis.

OBJECTIVES: To measure levels of soluble cytochrome c, a clinical marker of apoptosis in patients with liver disease; determine whether soluble cytochrome c is derived from the liver; and correlate soluble cytochrome c level with histology and disease activity. DESIGN: Laboratory research study with comparison group. SETTING: Liver Institute, at the Rabin Medical Center, Israel, and In Vitro Toxicology Laboratory, Canada. SUBJECTS: A total of 108 patients with liver disease and 30 healthy controls. INTERVENTIONS: Paired hepatic and portal vein samples were taken via the transjugular vein in patients after liver biopsy and transjugular intrahepatic portacaval shunt, and bile from patients with external biliary drainage. Soluble cytochrome c was measured with an enzyme-linked immunosorbent assay in peripheral blood. Apoptotic cells in liver tissue were identified by morphological criteria and quantitated with the dUTP nick-end-labelling (TUNEL) assay. MAIN OUTCOME MEASURES: Soluble cytochrome c level by type of liver disease by clinical and histological findings. RESULTS: Soluble cytochrome c concentration (mean 187.1 +/- 219.5 ng x mL(-1)) was significantly higher in patients with liver disease than in controls (39.8 +/- 35.1 ng x mL(-1); P = 0.0001), with highest levels in the primary sclerosing cholangitis group (mean 1041.0 +/- 2844.8 ng x mL(-1); P = 0.001). Cytochrome c levels were correlated with serum bilirubin, alkaline phosphatase, creatinine levels, necroinflammatory score and apoptotic index, but not with serum alanine aminotransferase and synthetic liver function tests. In the 16 paired samples, soluble cytochrome c level was higher in the hepatic (mean 267.9 +/- 297.0 ng x mL(-1)) than the portal vein (mean 169.2 +/- 143.3 ng x mL(-1)), and it was highly detectable in bile (mean 2288.0 +/-4596.0 ng x mL(-1)) (P = 0.001). Untreated patients with chronic viral hepatitis (B and C) had significantly higher levels (mean 282.8 +/-304.3 ng x mL(-1)) than treated patients (77.9 +/- 35.8 ng x mL(-1); P = 0.001). CONCLUSIONS: Soluble cytochrome c levels are increased in different types of liver disease. Soluble cytochrome c is probably derived from the liver and secreted into the bile. Levels correlate with the apoptotic index and are affected by antiviral treatment. Soluble cytochrome c may serve as a serum marker of apoptosis.

Adult↗
PubMed2002

Anomalous magnetic field dependence of the thermodynamic transition line in the isotropic superconductor (K,Ba)BiO3.

Thermodynamic (specific heat, reversible magnetization, tunneling spectroscopy) and transport measurements have been performed on high quality (K,Ba)BiO3 single crystals. The temperature dependence of the magnetic field H(C(p)) corresponding to the onset of the specific heat anomaly presents a clear positive curvature. H(C(p)) is significantly smaller than the field H(Delta) for which the superconducting gap vanishes but is closely related to the irreversibility line deduced from transport data. Moreover, the temperature dependence of the reversible magnetization presents a strong deviation from the Ginzburg-Landau theory emphasizing the peculiar nature of the superconducting transition in this material.

Journal Article↗
PubMed2002

[Family biography and mortality in East and West Germany].

Since more than 200 years, it has been well known that a marriage prolongs one's life. Current research distinguishes between protective and selective processes. However, it has been missed that today's marital biographies are not characterized by one marital status but through a sequence of different events and transitions. It is the aim of the present study to try to determine the effect of marital biographies and mortality. An East-West German comparison tests, if and how historical events influence this connection. The analysis is based on data from the German Socio-Economic Panel. It can be shown that the protective effect of being married cumulates over years. Furthermore, each change in marital status increases the risk of mortality. However, persons recover from negative events (divorce, widowhood) over time. In East Germany, despite of historical change in 1989/90, the impact of the marital biography is at least as significant as in West Germany.

Adult↗