Biomedical subjects

S Schmidt

Publications and source records attributed to S Schmidt.

At least 55 records · Page 3Linked to original sources

PubMed2005

[Anesthesiological management of the EXIT procedure. Case report and literature review].

The ex-utero intra-partum (EXIT) procedure enables the surgeon to perform invasive procedures in an infant during cesarean section before clamping the umbilical cord. Specific anesthesiological concepts are necessary for ensuring sufficient umbilical perfusion. We report the case of a 33-year-old female undergoing cesarean section in the 36th week of pregnancy because of a large fetal cervical tumor. The EXIT procedure was performed in order to secure the infant's airway during delivery. The anesthesiological management and interdisciplinary tasks are discussed in the literature review.

Adult↗

PubMed2005

[User acceptance of health telematics applications].

The user acceptance of health telematics in medical care plays a critical role in mediating the success of its implementation. Model assumptions evolving from different fields such as industry, health care and medical psychology are presented, and various perspectives for patients and providers involved in these models are highlighted. The impact of health telematics on health care results from four components: (a) the improvement of work characteristics and communication processes, (b) the enhancement of diagnostic and treatment quality via telematics, (c) technical and economic advantages and (d) communication tools for patient. The evidence concerning clinical, economic and psychosocial criteria within these domains is reviewed according to the published literature. Despite the fact that a considerable benefit of health telematics has been shown in individual studies, the evidence concerning the improvement of health care, the improvement of work and communication processes as well as concerning its clinical and cost effectiveness is still scarce. It is recommended to further integrate health telematics and health service research.

Attitude of Health Personnel↗

PubMed2005

[Cyclosporine monitoring in patients with chronic uveitis].

BACKGROUND: Cyclosporine (CsA) is a widely used drug in the treatment of posterior uveitis. Whereas treatment with CsA has considerably improved the visual prognosis of uveitis patients, the therapeutic benefits of CsA are partially outweighed by its adverse effects, most notably nephrotoxicity and hypertension. Recently, monitoring the CsA 2-h postdose level (C(2)) has been recommended as the most sensitive assay and predictor of clinical outcome in transplantation. PATIENTS AND METHODS: This prospective clinical trial included 15 patients with posterior uveitis who received oral CsA (5 mg/kg BW b.i.d.). The relationship of C(2) to C0 blood levels was analyzed and correlated with clinical safety and efficacy. RESULTS: A high intrapatient and interpatient variability was observed regarding the C0 values depending on several factors including comedication and intestinal resorption. C(2) values corresponded to control measurements of intraocular inflammation. CONCLUSIONS: C(2) monitoring offers a simple and accurate alternative for clinical monitoring of CsA. It allows the dose of CsA to be individualized effectively for each patient.

Adolescent↗

PubMed2005

Combined determination of selected radiological and morphological variables relevant for dental age estimation of young adults.

The mineralisation of third molars is one of the main criteria for dental age estimation of living subjects in criminal proceedings. Since the mineralisation of third molars is usually completed by the age of 19 or 20 years, this feature cannot be used to ascertain whether a person has attained the forensically relevant age of 21 years. This study examined whether determination based on an orthopantomogram of a combination of features relevant to dental age estimation of adults, supplies forensically useful information for ascertaining whether a person has attained 21 years of age. The features considered include the DMFT index of all permanent teeth, the DMFT index of all permanent teeth excluding third molars, the DFT index of third molars projecting beyond the occlusal plane, the eruption of third molars and the periodontal recession of second molars. A total of 650 conventional orthopantomograms of German subjects aged 18-30 years were evaluated. The statistical evaluation of our results was based on a discriminant analysis. It was carried out with two classes defined by two age groups: < or = 21 years and > 21 years. The probability of correct classification was 69.7% for males and 71.4% for females. It can be concluded that an evaluation of the variables reviewed in this paper does not by itself yield sufficient data to determine with the accuracy required in criminal proceedings whether a person has attained 21 years of age. The additional radiographic examination of the medial clavicular epiphyseal cartilage is recommended.

Adolescent↗

PubMed2005

[Combination therapy for fetal supraventricular tachycardia with flecainide and digoxin].

Persistent fetal supraventricular tachycardia (SVT) with more than 210 bpm frequently leads to congestive heart failure. We report on a case with SVT and congestive heart failure that converted into sinus rhythm within 19 days of therapy with flecainide and beta-acetyldigoxin. A 32-year-old II gravida I para (25 + 1 weeks of gestation) presented with fetal SVT of 267 bpm. A non-immunologic hydrops fetalis was diagnosed by ultrasound showing ascites, pleural and pericardial effusion and tricuspid regurgitation. Within 19 days of combination therapy with flecainide and digoxin, cardioversion was achieved. After 36 days of therapy no more signs of cardiac failure could be detected. A healthy boy was born at 38 + 6 weeks of gestation. Although cardioversion is expected after 72 h of therapy according to the literature, this fetus converted into sinus rhythm on day 19 of therapy. This indicates that patients should not be considered resistant to treatment within the first 3 - 4 days.

Adult↗

PubMed2005

[Interferon alpha-associated retinopathy in patients with chronic hepatitis C].

BACKGROUND: Interferons are a complex group of glycoproteins with antiviral, antiproliferative and immunomodulatory activity. They are used to treat different types of human neoplasms and chronic hepatitis C. Several case reports have described interferon-induced ocular side effects since the first case in 1990. PATIENT AND METHODS: We report about a 61-year-old female undergoing interferon 2alpha treatment who developed bilateral retinopathy during systemic therapy and provide a summary about ocular side effects and their consequences. CONCLUSIONS: Patients should be monitored by ophthalmologists before, during and after interferon therapy in order to avoid side effects like retinal neovascularisation and to prevent potential serious side effects.

Female↗

PubMed2005

[Ureteroiliac artery fistula -- a rare cause of macroscopic haematuria].

INTRODUCTION: Since its first description in 1939 not more than approximately 80 cases of ureteroiliac artery fistulas have been reported. The incidence seems to increase with the number of endo-vascular and endo-urological interventions. Risk factors include pelvic vascular surgery and surgery for malignancy, irradiation and ureteral stenting. Due to the intermittent symptomatology, the preoperative diagnosis and planning of the therapeutic approach are often difficult. CASE REPORT: We report the case of an ureteroiliac artery fistula caused by an iliac artery aneurysm following vascular surgery, and review the literature. CONCLUSIONS: In case of preoperative diagnosis it is of great importance to coordinate the cooperation of urologists, vascular surgeons and radiologists in order to achieve the best treatment for the patient.

Aged↗

PubMed2005

Impaired glutathione-conjugating capacity by cryopreserved human and rat hepatocytes.

The activity of glutathione transferase was measured in sonicates of fresh rat hepatocytes and of cryopreserved rat, human and dog hepatocytes in the presence of added glutathione and by using 1-chloro-2,4-dinitrobenzene (CDNB) as non-selective substrate. The glutathione-conjugating capacity was also investigated in the presence of CDNB alone (without glutathione) with intact fresh rat hepatocytes and cryopreserved rat and human hepatocytes. Finally, the intracellular level of glutathione was measured in these hepatocytes. The specific activity of glutathione transferase in sonicates of fresh rat hepatocytes (in the presence of added GSH and CDNB) was about 415 nmol/min/10(6) cells. The corresponding activities in cryopreserved rat, human and dog hepatocytes were approximately 320, 440 and 540 nmol/min/10(6) cells, respectively. In contrast, glutathione conjugation by the intact cryopreserved human and rat hepatocytes in the presence of CDNB alone was less than 10% of the corresponding conjugation by fresh rat hepatocytes, indicating that glutathione was depleted in these cryopreserved hepatocytes. Glutathione depletion was confirmed after analytical measurement of the glutathione levels in fresh and cryopreserved hepatocytes. In fresh rat hepatocytes the level of glutathione was 44 nmol/10(6) cells, whereas it was 2.5 and 4.4 nmol/10(6) cells in cryopreserved rat and human hepatocytes, respectively. In summary, glutathione transferase was active in these cryopreserved hepatocytes but the cryopreservation procedure likely causes depletion in the intracellular level of glutathione, resulting in an overall reduced glutathione conjugating capacity.

Animals↗

PubMed2005

Chemokine-receptor expression on T cells in lung compartments of challenged asthmatic patients.

BACKGROUND: The interaction of chemokines with their receptors strongly influences the migration of leucocytes. OBJECTIVE: In order to assess the contribution of these molecules to the local recruitment of T cells in bronchial asthma, we analysed the expression of 14 chemokine receptors on lung-derived T cells. METHODS: Chemokine-receptor expression by T cells derived from the peripheral blood, the bronchoalveolar lavage fluid and the bronchial mucosa was analysed by flow cytometry and immunohistochemistry. Expression profiles in healthy and mildly asthmatic individuals were compared, the latter prior and after segmental allergen provocation. RESULTS: Compared with peripheral blood, alveolar T cells expressed significantly more CCR2, CCR5, CCR6, CXCR3 and CCR4. However, no differences were observed between healthy controls and unchallenged asthmatics. In patients developing significant inflammatory responses following specific allergen challenge, a marked increase in the percentage of CCR4+ and CCR7+, and reduced numbers of CXCR3-bearing alveolar T cells were detected. Following specific allergen challenge, chemokine-receptor expression profiles of T cells from the alveolar space and the mucosa or the submucosa were similar, excluding a particular subcompartmentalization of the chemokine/chemokine-receptor system. CONCLUSION: The expression of certain chemokine receptors by lung T cells suggests a contribution to the physiological recruitment of T cells to the lungs, both in healthy controls and unchallenged mild asthmatics. However, strong allergen-induced airway responses were associated with a specific chemokine-receptor profile, suggesting the involvement of certain chemokine receptors in the pathogenesis of allergic bronchial inflammation.

Adult↗

PubMed2005

Integration of genomic data in Electronic Health Records--opportunities and dilemmas.

OBJECTIVES: In this paper we give an overview about the challenge the postgenomic era poses on biomedical informaticists. The occurrence of new (genomic) data types necessitates new data models, new viewing metaphors and methods to deal with the disclosure of genomic data. We discuss integration issues when inferring phenotype and genotype data. Another challenge is to find the right phenotype to genotype data in order to get appropriate case numbers for sound clinical genotype-phenotype inference studies. METHODS: Genomic data could be integrated in an Electronic Health Record (EHR) in several ways. We describe patient-centered and pointer-based integration strategies and the corresponding data types and data models. The inference mechanisms for the interpretation of row data contain different agents. We describe vertical, horizontal and temporal agents. RESULTS: We have to deal with several new data types, not being standardized for EHR integration. Genomic data tends to be more structured than phenotype data. Beyond the development of new data models, vertical, horizontal and temporal agents have to be developed in order to link genotype and phenotype. As the genomic EHR will contain very sensitive data, confidentiality and privacy concerns have to be addressed. CONCLUSIONS: Given the necessity to capture both environment and genomic state of a patient and their interaction, clinical information systems have to be redesigned. While genotyping seems to be automatable easily, this is not the case for clinical information. More integration work on terminologies and ontologies has to be done.

Computational Biology↗

PubMed2004

The experience of the support person involved in a lung transplant programme: results of a pilot study.

UNLABELLED: In contrast to the high priority most transplant programmes give to the recipient's support system there is a paucity of studies referring to the experience of the respective support persons. This study sought to focus on the subjective burden of support persons and their unmet needs. METHOD: A questionnaire was designed for a cross-sectional study using numerical rating scales and fill-in-the-gap-items concerning subjective burden, stress symptoms, unmet needs, suggestions to improve the support person's situation. Participants were 39 relatives of adult transplant patients (22 cystic fibrosis transplant recipients, 17 recipients with other aetiologies) who had transplants 5 years ago (mean). RESULTS: The acute illness stage was rated as extremely stressful by most of the respondents. However, even during the rehabilitation period, one third described themselves as very stressed. Stress related symptoms at or post transplant were reported by 82% of respondents (more mothers than partners). Symptoms mostly referred to depressive and anxiety states. Most support persons had to tackle organizational difficulties in order to stay with the recipient and faced financial burdens not refunded by agencies. Support persons made suggestions to improve the recipient's situation and those of other support persons. Regarding the recipient their advice referred to enhanced information giving, aspects of communication and better access to psychosocial professionals. Regarding another support person they suggested to be well-informed beforehand and to remain optimistic. CONCLUSIONS: Mothers in this study seemed to be particularly vulnerable as support persons and thus deserve special attention. Few resources may be needed to achieve considerable benefit for the support person, such as arranging accommodation or identifying a team member to relate to.

Adult↗

PubMed2004

A second-generation genomic screen for multiple sclerosis.

Multiple sclerosis (MS) is a debilitating neuroimmunological and neurodegenerative disorder. Despite substantial evidence for polygenic inheritance of the disease, the major histocompatibility complex is the only region that clearly and consistently demonstrates linkage and association in MS studies. The goal of this study was to identify additional chromosomal regions that harbor susceptibility genes for MS. With a panel of 390 microsatellite markers genotyped in 245 U.S. and French multiplex families (456 affected relative pairs), this is the largest genomic screen for MS conducted to date. Four regions met both of our primary criteria for further interest (heterogeneity LOD [HLOD] and Z scores >2.0): 1q (HLOD=2.17; Z=3.38), 6p (HLOD=4.21; Z=2.26), 9q (HLOD; Z=2.71), and 16p (HLOD=2.64; Z=2.05). Two additional regions met only the Z score criterion: 3q (Z=2.39) and 5q (Z=2.17). Further examination of the data by country (United States vs. France) identified one additional region demonstrating suggestive linkage in the U.S. subset (18p [HLOD=2.39]) and two additional regions generating suggestive linkage in the French subset (1p [HLOD=2.08] and 22q [HLOD=2.06]). Examination of the data by human leukocyte antigen (HLA)-DR2 stratification identified four additional regions demonstrating suggestive linkage: 2q (HLOD=3.09 in the U.S. DR2- families), 6q (HLOD=3.10 in the French DR2- families), 13q (HLOD=2.32 in all DR2+ families and HLOD=2.17 in the U.S. DR2+ families), and 16q (HLOD=2.32 in all DR2+ families and HLOD=2.13 in the U.S. DR2+ families). These data suggest several regions that warrant further investigation in the search for MS susceptibility genes.

Chromosome Mapping↗

PubMed2004

Reentrant phenomenon in the quantum phase transitions of a gas of bosons trapped in an optical lattice.

We calculate the location of the quantum phase transitions of a Bose gas trapped in an optical lattice as a function of effective scattering length a(eff) and temperature T. Knowledge of recent high-loop results on the shift of the critical temperature at weak couplings is used to locate a nose in the phase diagram above the free Bose-Einstein critical temperature T((0))(c), thus predicting the existence of a reentrant transition above T((0))(c), where a condensate should form when increasing a(eff). At zero temperature, the transition to the normal phase produces the experimentally observed Mott insulator.

Journal Article↗

PubMed2004

Evaluation of the development of lung hypoplasia in the premature lamb.

BACKGROUND: The death rate from human diaphragmatic hernia (CDH) ranges from 50 to 80%, mainly due to the associated lung hypoplasia. To prevent these irreversible pathological and physical defects, the question of intrauterine surgical intervention arises. The histological changes of the lung tissue after inducement of a diaphragmatic hernia were examined. Of special interest was the time elapsing until the development of lung hypoplasia. METHODS: A model of intrauterine inducement of diaphragmatic hernia was established using five fetal lambs to study consecutive pulmonary hypoplasia. Inducement of a diaphragmatic hernia was undertaken between 105 and 108 days' gestation. Lung tissue was examined histologically on postoperative days 8, 17, 21, 22, and 25 after inducement of the defect. RESULTS: On postoperative days 8, 17, and 21, no signs of pulmonary hypoplasia were found on histological examination. A pulmonary hypoplasia was found in two fetuses (on the 22nd and 25th postoperative day). The pathological and anatomical examination of a unilateral pulmonary hypoplasia after a short period of time shows that the artificially created diaphragmatic defect is a good model for producing a congenital diaphragmatic hernia. DISCUSSION: The severity of the pulmonary hypoplasia is related to the duration of lung compression by the herniated organs. The time elapsing until the development of lung hypoplasia is shorter than expected. Tracheal occlusion seems to be an effective strategy for treatment of the defect CDH, but the best technique for achieving occlusion, and particularly the ideal point in time to carry out "Fetendo," are unknown. Further research into this congenital illness is required in order to treat it.

Animals↗

PubMed2004

Watching the growth of bulk grains during recrystallization of deformed metals.

We observed the in situ growth of a grain during recrystallization in the bulk of a deformed sample. We used the three-dimensional x-ray diffraction microscope located at the European Synchrotron Radiation Facility in Grenoble, France. The results showed a very heterogeneous growth pattern, contradicting the classical assumption of smooth and spherical growth of new grains during recrystallization. This type of in situ bulk measurement opens up the possibility of obtaining experimental data on scientific topics that before could only be analyzed theoretically on the basis of the statistical characterization of microstructures. For recrystallization, the in situ method includes direct measurements of nucleation and boundary migration through a deformed matrix.

Journal Article↗

PubMed2004

Silica, silicosis and lung-cancer: results from a cohort study in the stone and quarry industry.

BACKGROUND: Workers compensated for silicosis outside the mining industry are at an increased risk of developing lung cancer. In the meta-analyses no data from Germany are involved. Furthermore, exposure data are necessary if a threshold value is to be assessed in order to reduce the risk for silicosis and also for lung cancer. METHOD: A cohort study among workers compensated for silicosis between 1988 and 2000 from the stone and quarry industry in Germany has been initiated. The cohort was followed up until the end of 2001. From all workers a detailed description of their jobs was assessed. RESULTS: Four hundred and forty workers were enrolled in the study. During the follow-up 144 workers died, compared with 74.35 expected cases based on the mortality rates of the general population from Germany, leading to a standard mortality ratio (SMR) of 1.94 (95% CI 1.63-2.28). Lung cancer was the cause of death in 16 cases (SMR 2.40; 95% CI 1.37-3.90). All workers had a peak exposure above 0.15 mg/m3, the current threshold value. The cumulative exposure was above 2 mg/m3.years and the average exposure was 0.10 mg/m3 or larger. No association between the exposure and the risk of developing lung cancer could be observed. CONCLUSIONS: Workers from the stone and quarry industry compensated for silicosis are at an increased risk of developing lung cancer. In order to reduce that risk, the exposure has to be lowered, with a peak exposure below 0.15 mg/m3 and an average exposure below 0.10 mg/m3.

Adult↗

PubMed2004

The methionine synthase polymorphism D919G alters susceptibility to primary central nervous system lymphoma.

Primary central nervous system lymphomas (PCNSL) frequently reveal genomic instability. We analysed different functional genetic variants affecting the folate and homocysteine metabolism important for DNA integrity in 31 PCNSL patients and 142 controls. We found significantly less carriers of the methionine synthase c.2756A>G (D919G) missense polymorphism among the patients (0.16 vs 0.42; odds ratio 0.26, CI(95%): 0.09-0.74; P=0.005), suggesting a protective function of the G allele. These data stimulate further epidemiological and functional studies focusing on the role of homocysteine and folate metabolism in lymphoma tumorigenesis.

5-Methyltetrahydrofolate-Homocysteine S-Methyltran↗

PubMed2004

SolEmuls-novel technology for the formulation of i.v. emulsions with poorly soluble drugs.

Intravenously injectable o/w emulsions of drugs being poorly soluble in water and simultaneously in oils need to be produced by locating the drug in the interfacial lecithin layer, e.g. amphotericin B. For achieving this, up to now organic solvents were required. The objective was to develop a solvent-free production method for such emulsions. Drug and the pre-formed parenteral emulsion Lipofundin were mixed and subjected to high pressure homogenisation. Drug powder and emulsions were characterised regarding size and physical stability by photon correlation spectroscopy (PCS), laser diffractometry (LD) and zeta potential measurements. Drug incorporation was studied using light microscopy, electron microscopy (EM) and a centrifugation test to separate non-dissolved drug. Amphotericin B and carbamazepine were used as model drugs. The high streaming velocities lead to accelerated drug dissolution and partitioning into the interfacial layer (so-called "solubilisation by emulsification", SolEmuls Technology). The interfacial layer could incorporate (solubilise) a certain amount of drug, revealed by EM pictures. Exceeding this concentration, hybrid dispersions were formed consisting of drug-loaded oil droplets and drug nanocrystals of similar size (approximately 200 nm). Both dispersion types are i.v. injectable opening the opportunity to deliver the drug in a concentrated form at desired low injection volume, e.g. 10 mg/ml.

Amphotericin B↗