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T Unger

Publications and source records attributed to T Unger.

At least 19 recordsLinked to original sources
PubMed2006

Implementation of semi-automated cloning and prokaryotic expression screening: the impact of SPINE.

The implementation of high-throughput (HTP) cloning and expression screening in Escherichia coli by 14 laboratories in the Structural Proteomics In Europe (SPINE) consortium is described. Cloning efficiencies of greater than 80% have been achieved for the three non-ligation-based cloning techniques used, namely Gateway, ligation-indendent cloning of PCR products (LIC-PCR) and In-Fusion, with LIC-PCR emerging as the most cost-effective. On average, two constructs have been made for each of the approximately 1700 protein targets selected by SPINE for protein production. Overall, HTP expression screening in E. coli has yielded 32% soluble constructs, with at least one for 70% of the targets. In addition to the implementation of HTP cloning and expression screening, the development of two novel technologies is described, namely library-based screening for soluble constructs and parallel small-scale high-density fermentation.

Amino Acid Sequence↗
PubMed2006

SPINE bioinformatics and data-management aspects of high-throughput structural biology.

SPINE (Structural Proteomics In Europe) was established in 2002 as an integrated research project to develop new methods and technologies for high-throughput structural biology. Development areas were broken down into workpackages and this article gives an overview of ongoing activity in the bioinformatics workpackage. Developments cover target selection, target registration, wet and dry laboratory data management and structure annotation as they pertain to high-throughput studies. Some individual projects and developments are discussed in detail, while those that are covered elsewhere in this issue are treated more briefly. In particular, this overview focuses on the infrastructure of the software that allows the experimentalist to move projects through different areas that are crucial to high-throughput studies, leading to the collation of large data sets which are managed and eventually archived and/or deposited.

Computational Biology↗
PubMed2006

Specificity and timing of neocortical transcriptome changes in response to BDNF gene ablation during embryogenesis or adulthood.

Brain-derived neurotrophic factor (BDNF) has been reported to be critical for the development of cortical inhibitory neurons. However, the effect of BDNF on the expression of transcripts whose protein products are involved in gamma amino butric acid (GABA) neurotransmission has not been assessed. In this study, gene expression profiling using oligonucleotide microarrays was performed in prefrontal cortical tissue from mice with inducible deletions of BDNF. Both embryonic and adulthood ablation of BDNF gave rise to many shared transcriptome changes. BDNF appeared to be required to maintain gene expression in the SST-NPY-TAC1 subclass of GABA neurons, although the absence of BDNF did not alter their general phenotype as inhibitory neurons. Furthermore, we observed expression alterations in genes encoding early-immediate genes (ARC, EGR1, EGR2, FOS, DUSP1, DUSP6) and critical cellular signaling systems (CDKN1c, CCND2, CAMK1g, RGS4). These BDNF-dependent gene expression changes may illuminate the biological basis for transcriptome changes observed in certain human brain disorders.

Animals↗
PubMed2006

High-protein nutrition during pregnancy and lactation programs blood pressure, food efficiency, and body weight of the offspring in a sex-dependent manner.

Maternal low-protein diet during pregnancy is a risk factor for cardiovascular disease of the offspring in later life. The impact of high-protein diet during pregnancy on the cardiovascular phenotype of the offspring, however, is still unknown. We examined the influence of a high-protein diet during pregnancy and lactation on the renal, hemodynamic, and metabolic phenotype of the F1 generation. Female Wistar rats were either fed a normal protein diet (20% protein: NP) or an isocaloric high-protein diet (40% protein: HP) throughout pregnancy and lactation. At weaning, the offspring were fed with standard diet, and they were allocated according to sex and maternal diet to four groups: normal-protein male (NPm, n = 25), normal-protein female (NPf, n = 19), high-protein male (HPm, n = 24), high-protein female (HPf, n = 29). During the experiment (22 wk), the animals were characterized by repeated measurement of body weight, food intake, blood pressure, glucose tolerance, energy expenditure, and kidney function. At the end of the study period histomorphological analyses of the kidneys and weight measurement of reproductive fat pads were conducted. There were no differences in birth weight between the study groups. No influence of maternal diet on energy expenditure, glucose tolerance, and plasma lipid levels was detected. Blood pressure and glomerulosclerosis were elevated in male offspring only, whereas female offspring were characterized by an increased food efficiency, higher body weight, and increased fat pads. Our study demonstrates that a high-protein diet during pregnancy and lactation in rats programs blood pressure, food efficiency, and body weight of the offspring in a sex-dependent manner.

Adaptation, Physiological↗
PubMed2005

Vascular protection in diabetes: a pharmacological view of angiotensin II type 1 receptor blockers.

Vascular protection is key to reducing the morbidity associated with diabetes. Angiotensin II is known to exert a variety of deleterious effects on the vasculature, and this is likely to be a major explanation of the protective benefits observed with blockade of the renin-angiotensin-aldosterone system (RAAS). Intriguingly, RAAS blockade also appears to reduce the onset of new diabetes, which points to a fundamental effect on metabolism. Recent developments have thrown new light onto the mechanism of these effects. The importance of unopposed stimulation of the angiotensin II type 2 (AT(2)) receptor in vascular protection is recognised, and recent studies have revealed that some angiotensin II type 1 (AT(1)) receptor blockers (ARBs) show partial peroxisome proliferator-activated receptor-gamma (PPARgamma) agonistic activity in vitro, an effect that is at least partly due to direct interaction with PPARgamma itself. There is a clear order of potency among the ARBs, with telmisartan the most potent and the only ARB to show an effect at physiologically achievable plasma concentrations. Adiponectin, an adipokine closely involved with glucose sensitisation, is also modulated by the relative activation of AT(1) and AT(2) receptors. Such effects would suggest that important benefits may result from the use of ARBs in clinical practice, although confirmation of the clinical relevance will depend upon the results of numerous ongoing studies.

Angiotensin II Type 1 Receptor Blockers↗
PubMed2005

Differential expression of angiotensin receptors in human cutaneous wound healing.

BACKGROUND: Angiotensin AT1 and AT2 receptors are expressed in human skin. Furthermore, AT2 receptors have been reported to be upregulated during tissue repair and remodelling in various noncutaneous human tissues. OBJECTIVES: Detection of alterations in angiotensin II receptor expression during wound healing in human skin. METHODS: Three models were employed. (i) Primary human keratinocytes were razor scraped in culture flasks and alterations in the expression of angiotensin receptor mRNA determined by semiquantitative reverse transcription-polymerase chain reaction for 1-12 h thereafter. (ii) Early wound healing (48 h after cutting) was studied in punch biopsies from human skin ex vivo by means of immunohistochemical staining using polyclonal antibodies against the AT1 or AT2 receptor. (iii) In vivo wound healing was studied in sections of human cutaneous scars by immunohistochemistry to determine receptor expression early (2 days) and late (2 weeks-3 months) after surgery. RESULTS: In all experimental settings, an upregulation of both receptor subtypes was noticed after wounding. Immunohistochemically stained skin sections showed a stronger expression of AT2 than of AT1 receptors within the area of scarring. Enhanced receptor expression was detectable as early as 24 h after injury and lasted for up to 3 months. CONCLUSIONS: From these data, we conclude that angiotensin AT1 and AT2 receptors are upregulated in human cutaneous wounds, giving further support to the concept that angiotensin II plays a role even at an early stage during cutaneous wound healing.

Biopsy↗
PubMed2004

Shear band formation in granular media as a variational problem.

Strain in sheared dense granular material is often localized in a narrow region called the shear band. Recent experiments in a modified Couette cell provided localized shear flow in the bulk away from the confining walls. The nontrivial shape of the shear band was measured as the function of the cell geometry. First, we present a geometric argument for narrow shear bands that connects the function of their surface position with the shape in the bulk. Assuming a simple dissipation mechanism, we show that the principle of minimum dissipation of energy provides a good description of the shape function. Furthermore, we discuss the possibility and behavior of shear bands that are detached from the free surface and are entirely covered in the bulk.

Journal Article↗
PubMed2004

Patterns of antihypertensive drug utilization in primary care.

BACKGROUND: In the treatment of hypertension, physicians' attitudes and practice patterns are receiving increased attention as contributors to poor blood pressure (BP) control. Thus, current use of antihypertensive drugs in primary care was analyzed and the association with selected physician and patient characteristics was assessed. METHODS: The Hypertension and Diabetes Risk Screening and Awareness (HYDRA) study is a cross-sectional point prevalence study of 45,125 primary care attendees recruited from a representative nationwide sample of 1912 primary care practices in Germany. Prescription frequencies of the various antihypertensive drugs in the individual patients were recorded by the physicians using standardized questionnaires. We assessed the association of patient variables [age, gender; co-morbidities such as diabetes, nephropathy or coronary heart disease (CHD)] and physician variables (general practitioner vs internist, guideline adherence, etc.) with drug treatment intensity and prescription patterns. RESULTS: Of all 43,549 patients for whom a physician diagnosis on hypertension or diabetes was available, 17,485 (40.1%) had hypertension. Of these hypertensive patients, 1647 (9.4%) received no treatment at all, 1191 (6.8%) received non-pharmacological measures only, and 14,647 (83.8%) were given one or more antihypertensive drugs. Drug treatment rates were lower in young patients (16-40 years: 57.4%). BP control was poor: 70.6% of all patients were not normalized, i.e., had BP >/=140/90 mmHg. Antihypertensive treatment was generally intensified with increasing age, or if complications or comorbidities were present. The use of the different drug classes was rather uniform across the various patient subgroups (e.g., by age and gender). Individualized treatment with regard to co-morbidities as recommended in guidelines was not the rule. Adherence to guidelines as self-reported by physicians as well as other physician characteristics (region, training etc.) did not result in more differentiated prescription pattern. CONCLUSIONS: Despite the broad armamentarium of drug treatment options, physicians in primary care did not treat hypertension aggressively enough. Treatment was only intensified at a late stage, after complications had occurred. Treatment should be more differentiated in terms of coexisting morbidities such as diabetes, nephropathy, or CHD.

Adolescent↗
PubMed2004

Lessons from ALLHAT. Are low budget diuretics first line therapy in hypertension?

Diuretics are well-established and nowadays also cheap cardiovascular agents. In contrast to the most recent American hypertension guidelines (JNC 7) which ascribe a singular place to diuretics in the first-line treatment of hypertension following a one-sided interpretation of the ALLHAT results, in the balanced guidelines of the European Society of Hypertension (ESH) published in 2003, they are placed alongside beta-blockers, ACE inhibitors, sartans and calcium antagonists as the drugs of first choice, but not given preference. Previous scientific evidence and clinical experience is to a certain extent in line with this classification of diuretics. On the basis of the indisputable dose-dependent potential for side-effects such as hypokalaemia, diabetogenicity and stimulation of neurohumoural systems, I personally consider diuretics to be inferior to the more recent substance groups, particularly the RAS inhibitors. I would therefore welcome it if diuretics in the future were removed from the monotherapy of hypertension and offered from the outset as low-dosed combination partners for RAS inhibitors, beta-blockers and also calcium antagonists. In this role they could only do good and not cause any damage.

Antihypertensive Agents↗
PubMed2004

Recognition and management of overweight and obesity in primary care in Germany.

BACKGROUND: In contrast to the well-documented high prevalence of overweight and obesity in the general population, the prevalence, recognition rates and management by primary care physicians--as the core gatekeeper in the health care system--remains poorly studied. PURPOSE OF THE STUDY: To examine (1) the point prevalence of overweight (BMI 25.0-29.9 kg/m(2)) and obesity (BMI> or =30 kg/m(2)) in primary care patients, (2) prevalence patterns in patients with high-risk constellations (diabetes, hypertension, cardiovascular disease, etc.), (3) doctors' recognition and interventions, as well as patients' use and perceived effectiveness of weight-loss interventions and (4) factors associated with non-treatment. METHODS: Cross-sectional point prevalence study of 45 125 unselected consecutive primary care attendees recruited from a representative nationwide sample of 1912 primary care practices. MEASURES: (1) standardized clinical appraisal of each patient by the physician (diagnostic status and recognition, severity, comorbidity, current and past interventions). (2) Patient self-report questionnaire: height and weight, illness history, past and current treatments and their perceived effectiveness, health attitudes and behaviors. RESULTS: (1) In all, 37.9% of all primary care attendees were overweight, 19.4% obese. (2) Rates for overweight and obesity were highest in patients with diabetes (43.6 and 36.7%) and hypertension (46.1 and 31.3%), followed by patients with cardiovascular disorders. Rates of overweight/obesity increased steadily by the number of comorbid conditions. (3) Doctors' recognition of overweight (20-30%) and obesity (50-65%) was low, patients' actual use of weight control interventions even lower (past 12 months: 8-11%, lifetime: 32-39%). Patient success rates were quite limited. (4) Co- and multimorbidity in particular as well as other patient and illness variables were identified as predictors for recognition, but prediction of patients' actual use of weight loss interventions was limited. CONCLUSIONS: Primary care management of overweight and obesity is largely deficient, predominantly due to four interrelated factors: doctors' poor recognition of patients' weight status, doctors' inefficient efforts at intervention, patients' poor acceptance of such interventions and dissatisfaction with existing life-style modification strategies.

Age Distribution↗
PubMed2003

[Aim, design and methods of the "Hypertension and diabetes screening and awareness" -- (HYDRA) study].

Aim of the study is a comprehensive clinical-epidemiological description of the prevalence of arterial hypertension and diabetes among primary care patients along with an assessment of doctor's recognition rates and prescription behaviour. The paper describes methods and design of the study and provides background information on the sampling process, instruments used as well as characteristics of doctors and patients. The study is based on a nationally representative sample of 1,912 primary care doctors and 45,000 patients that attended the doctors' office on the target days. The patients were also characterized by laboratory tests. The first stage of study consisted of a comprehensive description of the doctors' characteristics in terms of psychosocial, qualification- and provider aspects as well as attitudes towards hypertension and diabetes and their management. In the second stage all patients completed a questionnaire to describe their health behaviour and attitudes as well as the treatment history and therapy. In the third stage all patients were characterized by their doctors in terms of their diagnostic status and their past and current interventions.

Adolescent↗
PubMed2003

[Management of diabetes and hypertension: how do primary care physicians judge their performance?].

With regard to the management of hypertension and diabetes, HYDRA reveals that doctors report multiple problems in their everyday practice. Being confronted with an average of 73 patients a day, with almost every second having either diabetes or hypertension, frequently associated with multiple comorbid conditions, the core obstacle is the time factor. Doctors do not have sufficient time to perform diagnostic tests and especially no time for non-drug interventions of any type. Further available treatment guidelines are only used in 1 out of 2 doctors. Further they seem not to affect doctors performance significantly.

Adult↗
PubMed2003

[Hypertension, diabetes mellitus and comorbidity in primary care].

Almost every second patient seeing a primary care doctor suffers from arterial hypertension and about every fifth has diabetes mellitus. These diseases often occur at the same time. They are associated in more than 80% of the cases with other severe concomitant and subsequent diseases (heart attack, stroke, renal failure, neuropathy etc.). The magnitude especially of subsequent and concomitant diseases, the dimension of the personal suffering and the immense diagnostic and therapeutic challenges for the doctors have been massively underestimated so far. The article informs about the prevalence of the above disease, and structure of the problem. Before the background of an extremely high patient load seen by German General Physicians, the mainstay challenge is highlighted how to achieve further improvements of the quality of care on the basis of scientific guidelines alone, without a concomitant change in the system structure.

Adolescent↗
PubMed2002

Elastic behavior in contact dynamics of rigid particles.

The systematic errors due to the practical implementation of the contact dynamics method for simulation of dense granular media are examined. It is shown that, using the usual iterative solver to simulate a chain of rigid particles, effective elasticity and sound propagation with a finite velocity occur. The characteristics of these phenomena are investigated analytically and numerically in order to assess the limits of applicability of this simulation method and to compare it with soft particle molecular dynamics.

Journal Article↗
PubMed2002

Peripherally applied candesartan inhibits central responses to angiotensin II in conscious rats.

In the brain, angiotensin II (Ang II) induces various effects such as blood pressure increase, the release of arginine vasopressin (AVP) and drinking behaviour. In the present study, we investigated the ability of the angiotensin II type-I (AT(1)) receptor antagonist, candesartan, administered peripherally, to block the central effects of Ang II. Experiments were performed in conscious rats instrumented with an intracerebroventricular (i.c.v.) cannula or a guide cannula into the paraventricular nucleus (PVN) and arterial and femoral catheters. Candesartan was administered intravenously (i.v.) at doses of 0.01, 0.1, 1 or 10 mg/kg. Controls received vehicle (0.05 N Na(2)CO(3)). The drinking response ( n=10-11 per group), the pressor response ( n=7-8) and the release of AVP into the circulation ( n=10-11) following i.c.v. Ang II (100 ng) were measured 0.5, 2, 4 and 24 h following i.v. drug application. Candesartan inhibited the central responses to i.c.v. injected Ang II dose- and time-dependently. At the highest dose (10 mg/kg), the drinking and pressor responses and the release of AVP in response to i.c.v. Ang II were completely blocked at 4 h and still markedly inhibited 24 h after the antagonist application (by 85%, 48% and 86%, respectively). The lowest dose of the antagonist was without effect. In a further experiment, the release of AVP induced by microinjection of Ang II (100 ng) into the PVN was determined before and 4 h after administration of vehicle or candesartan (1 mg/kg, i.v.). Candesartan completely blocked the AVP release into the circulation induced by Ang II microinjection into the PVN. Our results demonstrate that candesartan administered peripherally effectively inhibits responses mediated by AT(1) receptors localised in periventricular brain regions as well as inside the blood-brain-barrier.

Angiotensin II↗