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Biomedical subjects

A Hofmann

Publications and source records attributed to A Hofmann.

At least 19 recordsLinked to original sources
PubMed2007

[Epidemiology of chlamydial infections].

Genital chlamydia infections are the most frequently diagnosed bacterial sexually transmitted infection (STI) worldwide. Infections with chlamydia trachomatis are not notifiable in Germany. Since 2002, a STI sentinel surveillance including 243 sentinel sites has been set up in Germany. Between January 2003 and June 2006, 6.7% of 46,168 chlamydia tests were positive. Of the 1547 positive patients, 64.3% were women and the median age was 26 years. In this group, 60.4% of women and 29.3% of men were of non-German origin. Heterosexual contacts were stated as the possible source of infection for 42.9% of men and 26.4% of women. A total of 16.1% men and 38.6% women reportedly "always" used condoms with others than their permanent partner. The awareness of chlamydia infections needs to be improved among physicians, patients and the general population.

Chlamydia Infections↗
PubMed2006

Inhibition of porcine endogenous retroviruses (PERVs) in primary porcine cells by RNA interference using lentiviral vectors.

A potential risk in pig-to-human xenotransplantation is the transmission of PERVs to human recipients. Here we show for the first time the inhibition of PERV expression in primary porcine cells by RNA interference using lentiviral vectors. Cells were transduced with lentiviral vectors coding for short hairpin (sh) RNAs directed against PERV. In all primary porcine cells studied and in the porcine kidney cell line PK-15, expression of PERV-mRNA was significantly reduced as measured by real-time PCR. Most importantly, expression of PERV proteins was almost completely suppressed, as shown by Western blot analysis. Thus, lentiviral shRNA vectors could be used to knockdown PERV expression and create transgenic pigs with a reduced risk of PERV transmission during xenotransplantation.

Animals↗
PubMed2006

Molecular and immunological characterization of encoding gene and 14-3-3 protein 1 in Fasciola gigantica.

A cDNA encoding Fg14-3-3 protein 1 was cloned by immunoscreening of an adult-stage Fasciola gigantica cDNA library using a rabbit antiserum against tegumental antigens of the parasite. The protein has a deduced amino acid sequence of 252 residues and a calculated molecular weight of 28.7 kDa. It shows sequence identity values between 57.6 and 58.1% to the human 14-3-3 beta, zeta, theta, and eta proteins and is in a phylogenetic cluster with the 14-3-3 protein 1 of Schistosoma spp. Nucleic acid analyses indicate that the Fg14-3-3 protein 1 is encoded by a single copy gene and that this gene is expressed as a transcript of 1250 nucleotides. In adult and 4-week-old parasites the gene's transcriptional and translational products were localized in the gut epithelium, parenchyma, tegument cells, and in the reproductive organs. An antiserum against recombinant Fg14-3-3 protein 1 detected a slightly smaller 14-3-3 protein in the parasite's excretion/secretion material and showed cross-reactivity with 14-3-3 proteins in extracts of other trematodes and mouse. Antibodies against Fg14-3-3 protein were detected in the sera of rabbits as early as 2 weeks after infection with metacercariae of F. gigantica and the antibody titre increased continuously over a 10-week observation period.

14-3-3 Proteins↗
PubMed2006

Interaction of SO3 with c-ZrO2(111) films on Pt(111).

Single-crystalline sulfated c-ZrO2(111) films of the cubic (c) type have been prepared by reactive deposition of Zr onto Pt(111) in an O2 atmosphere and subsequent exposition to a SO3 atmosphere. The morphology, atomic structure, and composition have been examined by scanning tunneling microscopy, low-energy electron diffraction (LEED), Auger electron spectroscopy, and density functional theory (DFT) calculations. The clean c-ZrO2(111) films display a (2x2) surface structure. During SO3 exposure at room temperature, a clear (radical3xradical3)R30 degrees structure develops. At about 700 K, the SO3-induced (radical3xradical3)R30 degrees structure disappears and the bright (2x2) LEED pattern of the clean ZrO2 films reappears. The energies of plausible c-ZrO2(111)/SO3 structures have been examined by DFT. The (radical3xradical3)R30 degrees structure found in the experiments turned out to be the most stable one for temperatures below 700 K. At temperatures around 700 K, a disordered low coverage structure may exist, which can not be observed by conventional LEED. A comparison of cubic zirconia surfaces with the alternative tetragonal system yields similar results for the SO3 adsorption in the DFT calculations and shows that c-ZrO2 surfaces are good models for the industrial used tetragonal ZrO2 supports.

Journal Article↗
PubMed2006

[The cloverleaf plate for osteosythesis of humeral head fractures. Definition of the current position].

In this prospective study we evaluated the functional and radiological results obtained in 62 patients who had been treated for fracture of the humeral head by internal fixation with a cloverleaf plate. They were examined postoperatively, after 14 weeks and after an average follow-up of 75 weeks. Nine patients (14.5%) had dislocated 2-part fractures, 36 had 3-part fractures (58%; additional dislocations of the greater or lesser tubercle), 13 patients (21%) had 4-part fractures and 4 (5.6%) had luxation fractures of the humeral head. Early functional physiotherapy was started on the third day after surgery. The complications observed were: subcutaneous infection (2 cases; 3.2%), haematoma (2 cases; 3.2%), temporal paraesthesia of the axillary nerve (1 case; 1.6%). Only 4 (6.5%) patients suffered from necrosis of the humeral head (partial in 3, total in 1); in 2 cases (3.2%) we switched to a different procedure; in both these patients a humeral head prosthesis was implanted; in both these cases the clinical result was poor because of progressive varus dislocation. To improve mobility we performed arthrolysis in 8 cases (12.9%) and acromioplasty in 10 (16.1%), in addition to removing the plates after fracture consolidation confirmed by X-ray examination. In the present study those of our patients who had been treated with open reduction and internal fixation with a cloverleaf plate achieved average Neer scores of 77+/-13 and average Constant scores of 72.4+/-18, and the rates of complications or revisions were low. "Good" or "very good" results were obtained according to the Constant score in 59% of the treated patients. Even patients with complex 4-part fractures had average Constant scores of 72.7 points ("good"). The accuracy of the refixation of the greater tubercle, sufficiently low fixation of the cloverleaf plate and avoidance of varus position when the humeral head was repositioned were significant parameters influencing the functional outcome in our patients.

Adult↗
PubMed2006

[Ankyloglossia in an Anatolian Shepherd dog].

Ankyloglossia, commonknown as tongue-tie, is a rare congenital oral anomaly in dogs. A complete attachment of the lingual frenulum to the floor of the oral cavity leads to limited mobility of the tongue including problems during eating and swallowing. In humans ankyloglossia is a common anomaly in newborn infants. In our report a 5-month old Anatolian Shepherd dog was surgically treated and full function of the tongue could be achieved with a horizontal-to-vertical frenuloplasty.

Animals↗
PubMed2005

The influence of bone allograft processing on osteoblast attachment and function.

In order to assess the influence of eight different sterilisation and disinfection methods for bone allografts on adhesion, proliferation, and differentiation of human bone marrow stromal cells (BMSC), cells were grown in culture and then plated onto pieces of human bone allografts. Following processing methods were tested: autoclavation (AUT), low-temperature-plasma sterilisation of demineralised allografts (D-LTP), ethylene oxide sterilisation (EtO), fresh frozen bone (FFB), 80 degrees C-thermodisinfection (80 degrees C), gamma-irradiation (Gamma), chemical solvent disinfection (CSD), and Barrycidal-disinfection (BAR). The seeding efficiency was determined after one hour to detect the number of attached cells before mitosis started. The cell viability was determined after 3, 7, and 21 days. Tests to confirm the osteoblastic differentiation included histochemical alkaline phosphatase staining and RT-PCR for osteocalcin. Human BMSC showed greatest attachment affinities for D-LTP-, 80 degrees C-, and CSD-allografts, whereas less cells were found attached to AUT-, EtO-, FFB-, Gamma-, and BAR-probes. Cell viability assays at day 3 revealed highest proliferation rates within the FFB- and 80 degrees C-groups, whereas after 21 days most viable cells were found in D-LTP-, 80 degrees C-, CSD-, and Gamma-groups. BAR-treatment showed a considerably toxic effect and therefore was excluded from all further experiments. Highest AP-activity and gene expression of osteocalcin were detected in the D-LTP-group in comparison with all other groups. In summary, our results demonstrate that cell adhesion, final population, and function of BMSC are influenced by different disinfection and sterilisation methods. Therefore, processing-related alterations of BMSC-function may be important for the success of bone grafting. The experimental setup used in the present work may be useful for further optimisation of bone allograft processing.

Alkaline Phosphatase↗
PubMed2005

[Internal fixation of proximal humerus fractures].

BACKGROUND: Intramedullary nails and angle-fixed plates have recently been used in proximal humerus fractures. Rigid implants might be associated with an increased risk of failure in osteoporotic conditions. METHODS: Unstable fractures of the surgical neck were created in 24 pairs of human humeri. The biomechanical properties of four implants were analysed. These were a nail with conventional interlocking (PHN-K), a nail with spiral blade interlocking (PHN-S), the T-plate, and an internal fixator with elastic screw properties (reference). The specimens were subjected to axial loading and torque. Stiffness, plastic deformity, and load to failure were assessed. RESULTS: The PHN-S was stiffer than the internal fixator. The PHN-K and T-plate were stiffer only during torque. Less subsidence was observed for the PHN-S. This implant failed at higher loads than the other implants. CONCLUSIONS: The PHN-S offers biomechanical advantages in unstable fractures of the surgical neck of the humerus. Elastic implant properties, however, are disadvantageous.

Aged↗
PubMed2005

Building a sentinel surveillance system for sexually transmitted infections in Germany, 2003.

BACKGROUND/OBJECTIVES: Increases in STIs have been reported from the United States and Europe. Since 2001, only syphilis and HIV are notifiable in Germany. A sentinel surveillance system has been set up to assess the occurrence and trends of STIs and identify risk groups. METHODS: Through the sentinel system data are collected from local health offices (LHO), hospital based STI clinics and private practitioners (dermato-venerology, urology, gynaecology, or HIV). For every newly diagnosed laboratory confirmed infection of HIV, gonorrhoea, chlamydia, syphilis, or trichomoniasis physicians complete a standardised questionnaire regarding diagnosis, source of infection, and demographic information. Patients complete a questionnaire about sexual risk behaviour. The patient form is matched with the diagnosis form using a unique identifier number. Characteristics of sentinel patients were compared with those reported through the HIV and syphilis national notification system. RESULTS: 58 LHO, 14 hospital based STI clinics, and 160 private practitioners (53.1% dermato-venerologists) from all federal states participated in the study. 176 (75.9%) sentinel sites are located in cities of >100 000 inhabitants. From 1 March 2003-29 February 2004, a total of 1833 STIs have been reported, among them 452 chlamydia, 321 syphilis (10.9% of notified syphilis), 343 gonorrhoea, 269 HIV (15.7% of notified HIV). 925 (50.5%) of the patients were male, the median age was 31 years. Female patients were more often of foreign origin (chi(2) test; 70.0% v 26.3%; p<0.001). CONCLUSIONS: Our sentinel system will provide a base for detection of STI trends in Germany. In addition, information about sexual risk behaviour will enable us to target prevention at those most at risk for STIs.

Adolescent↗
PubMed2004

[Intramedullary osteosynthesis of the ulna in revision surgery].

The exact and adequate management of diaphyesal fractures of the forearm is necessary to ensure forearm motion. Unsatisfactory treatment can lead to loss of function and disability of forearm and hand movement, resulting in severe patient morbidity. Since the rotational and angulatory stresses at the fracture site are the superior factors which influence the outcome of the forearm fracture healing after surgical treatment, the implants must fulfill some general prerequisites including high biomechanical stability, less invasive surgical approach and adequate biological features. However, less clinical studies are known for cases of complicated ulnar fractures when additional revision surgery is necessary to restore form and function. Thus, the choice of implant in such difficult situations requires a profound knowledge and experience. In a series of seven clinical cases we report about the successful use of the ForeSight-nail in revision surgery of complicated ulnar fractures. The series include cases with refractures after plate removal, in-situ plate brokerage and a critical size bone non-union which were treated with interlocking intramedullary osteosynthesis technique.

Adult↗
PubMed2004

[Are angle-fixed implants with elastic properties advantageous for the internal fixation of proximal humerus fractures?].

There is a recent interest for the use of angle-fixed plates in the management of proximal humerus fractures. Rigid implants might be associated with an increased risk of cutting-out. In order to analyse the potential beneficial effects of the implant elasticity on fracture fixation, the biomechanical properties of a rigid and an elastic angle-fixed plating system were assessed in an experimental study. An unstable fracture of the surgical neck was created in 8 pairs of human humeri. Specimens were subjected to axial loading and torque. Stiffness, subsidence and load to failure were assessed. The implant with elastic properties was characterized by a lower torsional stiffness and a higher subsidence during axial loading and torque. This implant failed at lower loads than the rigid implant did. Elastic implant properties of angle-fixed plates have shown not to be advantageous for the management of fractures of the proximal humerus.

Bone Plates↗
PubMed2003

Role of chelate substituents and cis sigma-effect on the rate of ligand substitution at Pt(N-N-N) and Pt(N-N-C) centres.

Four complexes of the type [Pt(N-N-X)Cl](X = N or C) were tailor synthesized for mechanistic studies in methanol. The terdentate ligands included terpy, 4'-Ph-terpy, 4'-(2"-CF(3)-Ph)-terpy, and 4'-(2"'-CF(3)-Ph)-6-Ph-2,2'-bipy. The rate of substitution of the chloro ligand by thiourea, N,N'-dimethylthiourea, and N,N,N',N'-tetramethylthiourea was studied as a function of nucleophile concentration, temperature and pressure by using a stopped-flow technique. The observed pseudo-first-order rate constants for the substitution reactions obeyed the simple rate law k(obs) = k(2)[Nu]. Second-order kinetics and negative activation entropies and volumes support an associative substitution mechanism. At 298 K, the values of the second-order rate constant show a slight dependence on the nature of the moiety attached to the terpy ligand. Changing from a nitrogen sigma-donor to a carbon sigma-donor in the cis position, results in a deceleration of the substitution rate. The results suggest that the Pt-C bond in the cis position activates the metal centre in a different way than in the trans position.

Journal Article↗
PubMed2003

[Psychotherapeutic treatment of traumatic stress with the EMDR (Eye Movement Desensitization and Reprocessing) method].

EMDR (Eye Movement Desensitization and Reprocessing) is a method, developed at the end of the nineteen-eighties, for the treatment of the post-traumatic stress disorder (PTSD). The patient is asked to concentrate on certain aspect of the traumatic memory while keeping his eyes fixed on the movements of the therapist's finger. Apparently, this triggers information processing that results in appreciable relief for the patient. The method has proven to be equally as effective as behavioral-therapeutic techniques, and, has in the meantime, been included in national and international guidelines for the treatment of PTSD. The indications for EMDR treatment include not only PTSD, but, increasingly, also other, sometimes more severely chronic, it trauma sequelae. Within the framework of basic care, EMDR must be embedded within a treatment plan and should, where applicable, be combined with other methods.

Adolescent↗
PubMed2003

Bioengineered human bone tissue using autogenous osteoblasts cultured on different biomatrices.

Surgical treatment of critical-size posttraumatic bone defects is still a challenging problem, even in modern bone and joint surgery. Progress in cellular and molecular biology during the last decade now permits novel approaches in bone engineering. Recent conceptual and technical advances have enabled the use of mitotically expanded, bone-derived cells as a therapeutic approach for tissue repair. Using three different tissue carrier systems, we successfully cultivated human osteoblasts in a newly developed perfusion chamber. We studied cell proliferation and the expression of osteocalcin, osteopontin, bone morphogenetic protein-2A, alkaline phosphatase, and vascular endothelial growth factor as parameters for osteoblast function and viability. Adherence of highly enriched human osteoblasts had already started after 1 h and resulted in completely overgrown human bone pieces after 10 days. Expression analysis of bone-specific alkaline phosphatase indicated differentiating osteoblasts, whereas the high mRNA expression of osteocalcin and osteopontin revealed terminally differentiated osteoblasts and the process of mineralization. Additionally, gene expression was significantly higher when demineralized bone was used as biomatrix, compared to autoclaved bone and hydroxyapatite ceramics. We conclude that with our newly developed perfusion culture system, vital autogenous bone implants of clinically applicable size can be generated within 17 days in order to manage critical-size bone defects.

Animals↗
PubMed2003

[Uremic patients--late referral, early death].

BACKGROUND AND OBJECTIVE: A number of reports from various countries document that patients with renal failure who are referred late to renal units, have more complications e. g. lack of vascular access when dialysis has to be started as well as longer hospitalisation and have also a higher risk of early death. No data on these points are available from Germany. PATIENTS AND METHODS: In a retrospective analysis the timing of referral to the nephrologists was studied in two Departments of Medicine, e. g. Heidelberg and Vienna, for all patients who started renal replacement therapy. For patients in Heidelberg the relation between timing of referral and survival on dialysis was analysed using the Kaplan-Maier-technique. RESULTS: In Heidelberg 280 patients were analysed, 174 men, 106 women, age 61.8 +/- 14.5 years; 136 diabetic patients (9 type 1). They had been referred from GPs (n = 131), specialists (diabetologists, cardiologists; n = 20), emergency departments (n = 33), other hospitals (n = 90) or other institutions (n = 16). The measured median creatinine clearance at the time of referral was 14 ml/min (5-34). The median interval between referral and start of dialysis was 17 weeks. 137 patients had been referred < 17 weeks and 143 patients > or = 17 weeks prior to the start of dialysis. 97 of the 111 patients referred < or = 4 weeks prior to dialysis and 59 of the 169 patients referred > 4 weeks had to be dialysed with a central catheter. There were clear differences in patient survival. In patients referred < 17 weeks before the start of dialysis, the actuarial risk of death during the first 12 month was 34.2 % compared to 5.5 % (p < 0.0001) in patients referred > or = 17 weeks. Even the mortality in the interval between 12 and 24 months after the start of dialysis was clearly higher (15.3 %) in patients with late compared to early referral (11.4 %). CONCLUSION: Late referral of patients with impaired renal function to renal units causes more frequent problems of vascular access, longer hospitalisation, more medical complications, higher costs and higher mortality. Early referral of patients with renal failure is indispensable to improve dialysis outcomes.

Adult↗