Biomedical subjects

M Probst

Publications and source records attributed to M Probst.

At least 19 recordsLinked to original sources

PubMed2006

Epstein-barr virus-associated posttransplant lymphoproliferative disorder of donor origin after simultaneous pancreas-kidney transplantation limited to pancreas allograft: A case report.

A 45-year-old man was admitted with fever and elevated pancreas enzymes 6 months after simultaneous pancreas-kidney transplantation (SPKT). Function of the allografts was normal. Bacterial and fungal infections were excluded, while Epstein-Barr virus (EBV)-polymerase chain reaction (PCR) was positive. However, screening for EBV-associated lymphoma was negative. EBV infection did not respond to antiviral therapy. After an 18F-Fluorodeoxyglucose positron emission tomography positive signal and an abnormal computed tomography scan of the pancreas transplant, a biopsy revealed a diffuse large monomorphic B-cell lymphoma, which was confined to the grafted organ. Its origin was assigned to the donor by microsatellite analysis. Reduction of immunosuppression and immunotherapy with rituximab was unsuccessful. After 10 weeks, the patient developed an acute hemolytic uremic syndrome which required explantation of the allografts. Subsequent to the intervention, fever disappeared, EBV DNA became undetectable and lymphoma screening remained negative. In posttransplant lymphoproliferative disorder of donor origin after SPKT, transplantectomy may be a curative therapy.

Adult↗

PubMed2006

Psychomotor performance and sequence planning in anorexia nervosa before and after weight restoration.

BACKGROUND: In the study of psychomotor performance in anorexia nervosa (AN), motor control has not been studied extensively. The present study explores sequence planning in a sample of AN patients. METHOD: A group of 26 female restricting AN inpatients, aged 14 to 25, was compared with 24 healthy women matched for age and educational level. During the performance of a simple copying task, in which movement planning, but not working capacity, was challenged, the ease with which generally favored graphic production rules could be applied was manipulated. Computerized recordings of the drawing movements allowed detailed analyses of reaction and movement times and of drawing sequences. Fifteen patients were retested after weight restoration, as were 15 controls. RESULTS: Copying patterns that normally elicit a conflict between preferred graphic production rules induced significantly less slowing in the reaction times of the anorexia nervosa patients than in the controls, both before and after weight restoration. There were no group differences as regards the consistency with which the implicit production rules were applied. DISCUSSION: AN patients seem to show a fast response style combined with good sequence planning capacity.

Adaptation, Psychological↗

PubMed2005

Bond selective dissociative electron attachment to thymine.

Free-electron attachment to thymine and partially deuterated thymine, where D replaces H at all carbon atoms, is studied in the electron energy range from about 0 to 15 eV. The formation of fragment anions that are formed by the loss of one or two H (D) atoms is analyzed as a function of the incident electron energy using a crossed electron/neutral beam apparatus in combination with a quadrupole mass spectrometer. By using partially deuterated thymine and quantum-chemical calculation a bond selectivity for the loss of one and two hydrogen atoms is observed that is determined only by the kinetic energy of the incident electron.

Anions↗

PubMed2005

Ionization energies of argon clusters: a combined experimental and theoretical study.

We have measured appearance energies of Ar(n)+, n<or=30, by electron impact of gas phase clusters. Quantum-chemical calculations have been performed to determine the adiabatic and vertical ionization energies of argon clusters up to n=4 and 6, respectively. The experimental appearance energy of the dimer ion approaches, under suitable cluster source conditions, the adiabatic ionization energy. The agreement with values obtained by photoionization and threshold photoelectron-photoion coincidence (TPEPICO) spectra demonstrates that autoionizing Rydberg states are accessible by electron impact. Appearance energies of larger clusters, though, exceed the TPEPICO values by about 0.5 eV.

Journal Article↗

PubMed2005

Imported leishmaniasis in Germany 2001-2004: data of the SIMPID surveillance network.

Leishmaniasis is a rare, non-notifiable disease in Germany. Epidemiological and clinical data, therefore, are scarce. Most infections seen in Germany are contracted outside the country. The German surveillance network for imported infectious diseases (Surveillance Importierter Infektionen in Deutschland, or SIPMID) recorded 42 cases of imported leishmaniasis (16 visceral, 23 cutaneous, and 3 mucocutaneous) from January 2001 to June 2004. Although most infections were acquired in European Mediterranean countries, the risk of infection was highest for travelers to Latin America. HIV coinfection was observed significantly more often in patients with visceral leishmaniasis than in patients with cutaneous/mucocutaneous leishmaniasis (31 vs. 4%, p=0.02). The median time to a definitive diagnosis was 85 days in cases of visceral leishmaniasis and 61 days in cases of cutaneous/mucocutaneous leishmaniasis, reflecting the unfamiliarity of German physicians with leishmanial infections. Visceral leishmaniasis was treated most frequently with amphotericin B, whereas cutaneous/mucocutaneous leishmaniasis was treated with a variety of local and systemic therapies. The findings presented here should serve to increase awareness as well as improve clinical management of leishmaniasis in Germany.

Adolescent↗

PubMed2004

Electron attachment to gas-phase uracil.

We present results about dissociative electron attachment (DEA) to gas-phase uracil (U) for incident electron energies between 0 and 14 eV using a crossed electron/molecule beam apparatus. The most abundant negative ion formed via DEA is (U-H)-, where the resonance with the highest intensity appears at 1.01 eV. The anion yield of (U-H)- shows a number of peaks, which can be explained in part as being due to the formation of different (U-H)- isomers. Our results are compared with high level ab initio calculations using the G2MP2 method. There was no measurable amount of a parent ion U-. We also report the occurrence of 12 other fragments produced by dissociative electron attachment to uracil but with lower cross sections than (U-H)-. In addition we observed a parasitic contaminating process for conditions where uracil was introduced simultaneously with calibrant gases SF6 and CCl4 that leads to a sharp peak in the (U-H)- cross section close to 0 eV. For (U-H)- and all other fragments we determined rough measures for the absolute partial cross section yielding in the case of (U-H)- a peak value of sigma (at 1.01 eV)=3 x 10(-20) m2.

Algorithms↗

PubMed2004

Epidemiology and clinical features of vivax malaria imported to Europe: sentinel surveillance data from TropNetEurop.

BACKGROUND: Plasmodium vivax is the second most common species among malaria patients diagnosed in Europe, but epidemiological and clinical data on imported P. vivax malaria are limited. The TropNetEurop surveillance network has monitored the importation of vivax malaria into Europe since 1999. OBJECTIVES: To present epidemiological and clinical data on imported P. vivax malaria collected at European level. MATERIAL AND METHODS: Data of primary cases of P. vivax malaria reported between January 1999 and September 2003 were analysed, focusing on disease frequency, patient characteristics, place of infection, course of disease, treatment and differences between network-member countries. RESULTS: Within the surveillance period 4,801 cases of imported malaria were reported. 618 (12.9%) were attributed to P. vivax. European travellers and immigrants were the largest patient groups, but their proportion varied among the reporting countries. The main regions of infection in descending order were the Indian subcontinent, Indonesia, South America and Western and Eastern Africa, as a group accounting for more than 60% of the cases. Regular use of malaria chemoprophylaxis was reported by 118 patients. With 86 (inter-quartile range 41-158) versus 31 days (inter-quartile range 4-133) the median symptom onset was significantly delayed in patients with chemoprophylaxis (p < 0.0001). Common complaints were fever, headache, fatigue, and musculo-skeletal symptoms. All patients survived and severe clinical complications were rare. Hospitalization was provided for 60% and primaquine treatment administered to 83.8% of the patients, but frequencies varied strongly among reporting countries. CONCLUSIONS: TropNetEurop data can contribute to the harmonization of European treatment policies.

Adult↗

PubMed2004

The predictive value of body mass index for the weight evolution in anorexia nervosa.

BACKGROUND: Low body weight is considered to be an important risk factor for poor outcome in anorexia nervosa (AN). OBJECTIVES: To study the relationship between body mass index (BMI) at the beginning of treatment and at follow-up. A BMI of 13 kg/m2 at admission was hypothesized as cut-off point for better versus worse evolution of weight after treatment. METHOD: The BMI of 232 female AN inpatients was calculated at admission and after 6 months and 1 year. RESULTS: An overall low correlation between BMI at admission and at 6 months (r = 0.27) and 1 year (r = 0.26) follow-up was found. A BMI value of 15 kg/m2 at admission was revealed as the best cut-off point for making predictions. CONCLUSIONS: Patients with an admission BMI below 15 kg/m2 have a significantly greater chance to develop a lower BMI value at follow-up than those with a higher BMI.

Adult↗

PubMed2003

Assessing the additional impact of fitness training in depressed psychiatric patients receiving multifaceted treatment: a replicated single-subject design.

PURPOSE: Exercise has been put forward as a therapeutic means for the treatment of clinical depression. METHODS: In this study, 29 patients, all with diagnosed with mood disorder, completed daily measurements of depression and physical well-being during periods ranging from 77 to 436 days (M = 146.5). Fitness training was added to the treatment after a period and changes before (A-phase) and after (B-phase) the implementation of this training were the subject of investigation. Data were analysed by means of randomization tests with an AB-design and time-series analysis. Replication of the findings was investigated using Fisher's multiplicative method. RESULTS: Adding fitness training to the treatment of clinical depression does not systematically lead to changes in self-reported feelings of depression on top of benefits that may be due to other treatments. CONCLUSIONS: Since the present findings are not in agreement with previous studies, the absence of statistically significant changes in self-reported feelings of depression is discussed within the complexity of the 'exercise - depression' relationship in inpatient populations. These included the severity of their depression, the potential ceiling effect of a multifaceted treatment programme and the initial increase in depression due to the confrontational nature of the intervention.

Adult↗

PubMed2003

Probing electronic states of Ne2+ and Ar2+ by measuring kinetic-energy-release distributions.

Dissociative decay of metastable, electronically excited neon and argon dimer ions produces fragment ions with strikingly dissimilar kinetic-energy-release distributions. The distributions have been modeled based on ab initio calculations of potential energy curves. The unusual bimodal distribution observed for dissociation of Ne2+ arises from competition between radiative and nonradiative decay of the long-lived II(1/2)(u) state. For Ar2+, however, electronic predissociation is insignificant.

Journal Article↗

PubMed2003

Electron attachment to uracil: effective destruction at subexcitation energies.

We demonstrate that electrons at energies below the threshold for electronic excitation (<3 eV) effectively decompose gas phase uracil generating a mobile hydrogen radical and the corresponding closed shell uracil fragment anion (U-H)(-). The reaction is energetically driven by the large electron affinity of the (U-H) radical. This observation has significant consequences for the molecular picture of radiation damage, i.e., genotoxic effects or damage of living cells due to the secondary component of high energy radiation.

DNA Damage↗

PubMed2003

Robotic-assisted laparoscopic radical cystectomy and intra-abdominal formation of an orthotopic ileal neobladder.

PURPOSE: To describe our technique of robotic-assisted laparoscopic radical cystectomy and intra-abdominal formation of an orthotopic neobladder (Hautmann) for treatment of transitional cell carcinoma of the bladder. METHODS: We describe our surgical technique in the worldwide first attempt to perform a robotic-assisted laparoscopic radical cystectomy and completely intra-abdominal formation of an orthotopic neobladder. The DaVinci System (Intuitive Surgical, Mountain View, CA, USA) was utilized to perform the procedure. RESULTS: Utilizing the DaVinci System the operation could be performed without any complications. Operating time was 8.5 hours, blood loss was 200 ml. The oncologic as well as the functional result of the reservoir were excellent. DISCUSSION: We here demonstrated that sophisticated laparoscopic procedures like the intra-abdominal formation of an orthotopic neobladder are accomplishable with robotic assistance.

Carcinoma, Transitional Cell↗

PubMed2002

[Robot-assisted laparoscopy in urology. Radical prostatectomy and reconstructive retroperitoneal interventions].

Complex reconstructive laparoscopic procedures in the field of urology such as radical prostatectomy and pyeloplasty have attracted increased attention in the past 2 years. However, extensive laparoscopic experience is required to master these procedures. Therefore, it remains questionable whether these techniques, which have been shown to be of profit to the patient in the hands of a specialist, will achieve widespread distribution. We have employed computer technology to bridge the gap between open surgery and laparoscopic access and used the daVinci Surgical System to establish laparoscopic radical prostatectomy as well as pyeloplasty and other retroperitoneal procedures at our institution. With experience of more than 70 procedures, we find that with the assistance of the daVinci Surgical System both radical prostatectomy and retroperiteoneal procedures can be easily translated from open to minimally invasive procedures with a considerably shorter learning curve and without compromising patient safety. We expect that large incisions will be soon a thing of the past in urologic surgery. Computer technology, together with mechanical engineering, will play a major role in enabling us to achieve better results despite minimal invasiveness.

Female↗

PubMed2001

Homogeneous assay based on 52 primer sets to scan for mutations of the ABCA1 gene and its application in genetic analysis of a new patient with familial high-density lipoprotein deficiency syndrome.

Familial high-density lipoprotein (HDL)-deficiency syndromes are caused by mutations of the ABCA1 gene, coding for the ATP-binding cassette transporter 1. We have developed a homogeneous assay based on 52 primer sets to amplify all 50 ABCA1 exons and approximately 1 kb of its promoter. The assay allows for convenient amplification of the gene from genomic DNA and easy mutational analysis through automatic sequencing. It obviates the need to use mRNA preparations, which were difficult to handle and posed a risk to miss splice junction or promoter mutations. The application of the test to the molecular analysis of a new patient with familial HDL-deficiency (Tangier disease) led to a discovery of two novel ABCA1 mutations: C2665del and C4457T.

ATP Binding Cassette Transporter 1↗

PubMed2001

Common variants in the gene encoding ATP-binding cassette transporter 1 in men with low HDL cholesterol levels and coronary heart disease.

HDL cholesterol (HDL-C) deficiency is the most common lipid abnormality observed in patients with premature coronary heart disease (CHD). Recently, our laboratory and others demonstrated that mutations in the ATP-binding cassette transporter 1 (ABCA1) gene are responsible for Tangier disease, a rare genetic disorder characterized by severely diminished plasma HDL-C concentrations and a predisposition for CHD. To address the question of whether common variants within the coding sequence of ABCA1 may affect plasma HDL-C levels and CHD risk in the general population, we determined the frequencies of three common ABCA1 variants (G596A, A2589G and G3456C) in men participating in the Veterans Affairs Cooperative HDL Cholesterol Intervention Trial (VA-HIT), a study designed to examine the benefits of HDL raising in men having low HDL-C (< or =40 mg/dl) and established CHD, as well as in CHD-free men from the Framingham Offspring Study (FOS). Allele frequencies (%) in VA-HIT were 31, 16, and 4 for the G596A, A2589G, and G3456C variants, respectively, versus 27, 12, and 2 in FOS (P<0.03). None of the variants were significantly associated with plasma HDL-C concentrations in either population; however, in VA-HIT, the G3456C variant was associated with a significantly increased risk for CHD end points, suggesting a role for this variant in the premature CHD observed in this population.

ATP Binding Cassette Transporter 1↗

PubMed2001

Body composition of anorexia nervosa patients assessed by underwater weighing and skinfold-thickness measurements before and after weight gain.

BACKGROUND: Weight restoration is a crucial element in the treatment of patients with anorexia nervosa. Therefore, the validity of different methods for measuring body composition is important. OBJECTIVE: We tested the concurrent validity of hydrodensitometry (underwater weighing) and anthropometry (12 skinfold thicknesses) and assessed body composition and subcutaneous fat before and after a refeeding program and a multifaceted program of therapy in a specialized inpatient unit for eating disorders. DESIGN: The body composition of a large sample of anorexia nervosa patients (97 restricting type, 33 binging-purging type) was studied by using 2 methods both before and after weight gain. We applied a behavioral contract for weight restoration with a minimum weekly gain of 700 g and a maximum of 3 kg. Bland-Altman analysis of agreement, Pearson correlation analysis, t tests, and analysis of covariance were used. RESULTS: There was good agreement between the results obtained by underwater weighing and by skinfold-thickness measurement (r = 0.76, P < 0.001); the results produced by the 2 methods did not differ significantly. On average, a significant weight gain (11.9 kg) was observed, composed of 6.6 kg fat and 5.3 kg fat-free mass. CONCLUSIONS: Body fat estimation by skinfold-thickness equation appeared to be as accurate as underwater weighing. The refeeding program led to a significant increase in body weight, of which 55.5% was body fat. The mean ratio of fat-free mass to fat mass at the end of the treatment was 3.4:1.

Adipose Tissue↗

PubMed2001

Novel diode laser-compatible fluorophores and their application to single molecule detection, protein labeling and fluorescence resonance energy transfer immunoassay.

We describe a series of new long-wave absorbing and fluorescing cyanine dyes and labels (based on a general logic for the design of such dyes), their spectra, covalent and noncovalent linkage to proteins, their use in single molecule detection (SMD) and as donors and acceptors, respectively, in fluorescence resonance energy transfer studies. The new labels represent water-soluble and reactive fluorophores whose quantum yields increase substantially if noncovalently or covalently bound to proteins. Due to their strong absorptions between 550 and 700 nm they are excitable by light-emitting diodes or diode lasers. Their high absorbances (epsilon around 100,000) and adequate fluorescence quantum yields (phi up to 0.68 if bound to proteins) along with their availability as reactive NHS esters make them viable labels for proteins and oligomers, e.g. in context with SMD or fluorescence energy transfer immunoassay which is demonstrated for the system HSA/anti-HSA.

Fluorescent Dyes↗

PubMed2001

Rapid quantification of human ABCA1 mRNA in various cell types and tissues by real-time reverse transcription-PCR.

BACKGROUND: The ABCA1 gene encodes for a member of subfamily A of the ATP-binding cassette transporters that plays an important role in cellular export of cholesterol and phospholipids; therefore, quantification of the ABCA1 mRNA is critical in many studies related to its expression and regulation by metabolic factors, nutritional status, and new antiatherogenic drug candidates. We developed a rapid, sensitive, specific, and reproducible real-time reverse transcription-PCR (RT-PCR) method for detection and quantification of ABCA1 transcripts in total RNA isolated from cultured human cells and tissues. METHODS: To quantify ABCA1 mRNA, we generated a calibration curve from serial dilutions of in vitro-transcribed RNA corresponding to an amplified ABCA1 cDNA 205-bp fragment (homologous calibrator). Two pairs of fluorescent hybridization probes were used to detect the ABCA1 and porphobilinogen deaminase (PBGD) mRNAs; the latter served as an internal control. PCR was performed as real-time amplification of ABCA1 mRNA in 100 ng of total RNA isolated from various human tissues, and cultured cells were calculated from the calibration curve. In addition, normalized values of target (ABCA1/PBGD ratio) were calculated. RESULTS: Using this method, we quantified ABCA1 transcripts in various human tissue samples as well as in monocytes, THP-1 cells, fibroblasts, and adipocytes. We demonstrated ABCA1 mRNA up-regulation during human adipocyte and monocyte differentiation. In addition, we examined the effect of cholesterol loading and deloading on ABCA1 expression in monocytes, THP-1 cells, and fibroblasts. CONCLUSIONS: Our RT-PCR assay allows the specific and highly reproducible detection and quantification of minute amounts of human ABCA1 mRNA. This new method is more accurate, more informative, and less laborious than the classic RT-PCR methods and Northern blot; it therefore could simplify all studies on ABCA1 mRNA expression.

ATP Binding Cassette Transporter 1↗