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Biomedical subjects

A Gröger

Publications and source records attributed to A Gröger.

17 recordsLinked to original sources

[Varicella associated necrotizing fasciitis in a child].

We present a rare case of necrotizing fasciitis in an 5-year-old infant with preexisting varicella infection. Initially, the patient showed acute pain and swelling of the left thorax with high inflammatory parameters and varicella-specific skin affections. MRT presented diffuse soft tissue swelling of the left chest consistent with necrotizing fasciitis. After aggressive surgical debridement of necrotic tissue and extirpation of axillary lymph nodes, the clinical course improved under appropriate parenteral antimicrobial therapy using penicillin and clindamycin. In conclusion, necrotizing fasciitis should be suspected in any child with a history of varicella infection and increasing complaints of pain and swelling in an extremity or other body area associated with increasing fever, erythema, lethargy, and irritability. Shock, multiorgan failure, and death will ensue if the diagnosis is not promptly recognized.

Chickenpox↗

Ring-shaped vortex domain in type-II superconductors.

We present results of experiments in superconducting niobium and numerical simulations showing the creation of a metastable ring-shaped vortex domain by heating. Such vortex rings, if pinned by structural defects, can exist forever.

Journal Article↗

[A rare case of cannabis arteritis].

A 24-year old woman, heavy cannabis smoker with progressive Raynauld's phenomenon and digital necrosis is presented. Systemic sclerosis and other connective tissue disorders as well as arteriosclerosis and arterial emboli were excluded with appropriate laboratory examinations. Arteriography revealed multiple forearm, palmar and digital occlusions with corkscrew-shaped vessels. Based on these characteristic arteriography and clinical findings, the diagnosis of cannabis-arteritis was finally retained. With careful necrectomy, conservative wound dressings and secondary prostacyclin therapy a complete healing of digital necrosis was observed. There was no recurrence during the 6 month-follow-up. This observation demonstrates that cannabis may represent a possible cofactor in the pathogenesis of arteritis in young smokers. Early recognition is important to avoid irreversible complications such as loss of digits.

Adult↗

[Experimental pathobiochemistry research of the knee joint fluid of ice hockey players and alpine skiers after sport injuries].

26 knee joint fluids, conditioned by injuries, of ice hockey players and alpine skiers had been analysed. The examination of the joint fluids were followed by 17 biochemical parameters, which were fixed before. The analysis of synovial fluid allows a differentiation between an inflamed and non-inflamed process. As a measure for the inflamed enzymatic potence appears the increase of the PMN-Elastase-Concentration with a relative lack of alpha1-Antitrypsin. The proteolytic potence of the PMN-Elastase is additional intensified by the parallel increase of the LDH-Activity and therewith linked to the oxidative tissue damage. Consequently, the altered synovial fluid of traumatised knee joints is an important factor of posttraumatic damage of cartilage. The biochemical analysis of traumatised knee joint fluids heads to identify these enzymes and therewith linked to the chance of treatment with appropriate enzyme inhibitiors. This leads to a reduction or even partly to a prevention of traumatised damage of cartilages.

Adolescent↗

Ten years of ice hockey-related-injuries in the German Ice Hockey Federation - A Ten Year Prospective Study/523 International Games -.

Since January 1986 all injuries in players of the German national hockey teams (juniors A/B and seniors A/B), which have occurred during international competitions, have been registrated and evaluated by using a strict definition of injury, standardized reporting strategies and diagnosis by the team physician. Patterns of injury have been identified and correlations between position, zone and cause of injury could be analysed and, as a consequence, measures were taken to prevent them. A total of 147 injuries forcing a consecutive absence from the game during 523 international games of the German national teams were reported. During the 10 year period there was a marked decrease of the total number and incidence of injuries. In addition, injury rate and average absence from game time improved. There were more frequent concussions of the brain but the total number of facial injuries dropped after the introduction of a visor and the full face mask especially in junior hockey. The forward was the position most at risk to be injured and most injuries were caused by players contact.

Arm Injuries↗

[Anthropometry and muscle force measurement of German male national junior hockey players].

In 1996 89 German male national junior hockey players were examined in respect to weight, height, age and body mass of the lower extremities. The average age was 16,8 +/- 1,4 years with an average height of 179,6 +/- 6,3 cm and weight of 73,9 +/- 8,9 kg. The Rohrer-index was 1,27 +/- 0,1. In a biomechanic test set up characteristic values of strength were determined. By position, defence man were as tall as forwards but heavier. Players in the age of 15 to 17 years had a higher mean relative maximum force in leg-extension than players in the age of 18 to 19 years. Forwards had better relative explosive force in leg-extension but a higher force deficit in knee flexion and extension. At the World Championship 1995/96 in Alberta German national junior players, seventh ranked, had the lowest mean Rohrer-index and were the tallest one, but had the mean lowest weight of all teams.

Adolescent↗

[What information do we need to treat the injured shoulder of a hockey player?].

Successful patient care of the injured shoulder of a hockey player involves interdisciplinary cupertino. Images allow an interpretation of a static dimension but may not be sufficient enough to develop a surgical treatment strategy, since all injuries to the shoulder have its origin in a dynamic pathology with some kind of external impact. This article classifies various traumatic shoulder problems and the mechanism of injury, it outlines clinical tests and stresses key facts an imaging report should include in order to plan conservative or surgical treatment. Basic treatment options as performed in our institution for the injured shoulder of a hockey player are summarised briefly.

Acromioclavicular Joint↗

31P-CP-MAS NMR studies on TPP+ bound to the ion-coupled multidrug transport protein EmrE.

The binding of tetraphenylphosphonium (TPP+) to EmrE, a membrane-bound, 110 residue Escherichia coli multidrug transport protein, has been observed by 31P cross-polarisation-magic-angle spinning nuclear magnetic resonance spectroscopy (CP-MAS NMR). EmrE has been reconstituted into dimyristoyl phosphatidylcholine bilayers. CP-MAS could selectively distinguish binding of TPP+ to EmrE in the fluid membrane. A population of bound ligand appears shifted 4 ppm to lower frequency compared to free ligand in solution, which suggests a rather direct and specific type of interaction of the ligand with the protein. This is also supported by the observed restricted motion of the bound ligand. The observation of another weakly bound substrate population arises from ligand binding to negatively charged residues in the protein loop regions.

Amino Acid Sequence↗

[Protection of autogenous cartilage transplants from resorption using membrane encapsulation].

In reconstruction of cartilage defects, autogenous transplantation is known as a reliable and experienced method. Although a clinical application has not been reported until now, tissue engineering permits in vitro production of autogenous cartilage transplants. Nevertheless, in both methods the cartilage is exposed to individually varying resorptive mechanisms. Among other methods for in vivo tissue protection, the encapsulation with a semipermeable polyelectrolytecomplex membrane could guarantee sufficient protection against resorptive influences. Human septal cartilage was encapsulated (group 1) with polyelectrolytecomplex membranes and subcutaneously implanted on the back of thymusaplastic nude mice. Cartilage implants without encapsulation (group 2) were used as control. Scanning electron microscopy and histochemical investigations were performed 1, 4, 8, 12 and 16 weeks after implantation. Group 1 showed no signs of resorption and chronic inflammation at all. In contrast, group 2 presented, correlating to the time of implanta-tion, increasing signs of cell death and fibrotic transformation, representing an increased activity of resorption. In conclusion, tissue encapsulation with a polyelectrolytecomplex membrane could ensure a sufficient protection of human cartilage transplants from resorptive influences. For the plastic-reconstructive surgeon the desired result becomes more calculable.

Animals↗

Macroencapsulation of human cartilage implants: pilot study with polyelectrolyte complex membrane encapsulation.

Autogenous cartilage transplantation is a generally accepted method in reconstructive surgery. A promising alternative to this established method could be represented by in vitro engineering of cartilage tissue. In both methods of autogenous transplantation, host response induces reduction of transplant size and transplant instability to an unforeseeable extent. To investigate if polyelectrolyte complex (PEC) membranes were able to avoid host-induced effects on implanted tissues without neglecting the tissue metabolism, human septal cartilage was encapsulated with polyelectrolyte complex membranes and subcutaneously implanted on the back of nude mice. Septal cartilage implants, without encapsulation served as control group. Histochemical and electron microscopic investigations were performed 1, 4, 8 and 16 weeks after implantation. In the case of an intact PEC-membrane no interactions between the host and the implant could be observed. In some implants, the capsule was torn in several areas and signs of chronic inflammation with the cartilage having been affected mildly could be observed. Implanted cartilage protected with PEC-encapsulation showed no signs of degeneration and significantly lower level of after effects of chronic inflammation than implanted cartilage without PEC-encapsulation. Therefore, it could be expected, that PEC membrane encapsulation offers a novel approach to protect cartilage implants from host response after autogenous transplantation.

Animals↗

The solution structure of VAT-N reveals a 'missing link' in the evolution of complex enzymes from a simple betaalphabetabeta element.

BACKGROUND: The VAT protein of the archaebacterium Thermoplasma acidophilum, like all other members of the Cdc48/p97 family of AAA ATPases, has two ATPase domains and a 185-residue amino-terminal substrate-recognition domain, VAT-N. VAT shows activity in protein folding and unfolding and thus shares the common function of these ATPases in disassembly and/or degradation of protein complexes. RESULTS: Using nuclear magnetic resonance (NMR) spectroscopy, we found that VAT-N is composed of two equally sized subdomains. The amino-terminal subdomain VAT-Nn (comprising residues Met1-Thr92) forms a double-psi beta-barrel whose pseudo-twofold symmetry is mirrored by an internal sequence repeat of 42 residues. The carboxy-terminal subdomain VAT-Nc (comprising residues Glu93-Gly185) forms a novel six-stranded beta-clam fold. Together, VAT-Nn and VAT-Nc form a kidney-shaped structure, in close agreement with results from electron microscopy. Sequence and structure analyses showed that VAT-Nn is related to numerous proteins including prokaryotic transcription factors, metabolic enzymes, the protease cofactors UFD1 and PrlF, and aspartic proteinases. These proteins map out an evolutionary path from simple homodimeric transcription factors containing a single copy of the VAT-Nn repeat to complex enzymes containing four copies. CONCLUSIONS: Our results suggest that VAT-N is a precursor of the aspartic proteinases that has acquired peptide-binding activity while remaining proteolytically incompetent. We propose that the binding site of the protein is similar to that of aspartic proteinases, in that it lies between the psi-loops of the amino-terminal beta-barrel and that it coincides with a crescent-shaped band of positive charge extending across the upper face of the molecule.

Adenosine Triphosphatases↗

[Surgical embolectomy after reanimation in central pulmonary embolism].

Central pulmonary embolism represents one of the most threatening complications in surgical patients. In most cases deep vein thrombosis of the lower extremities is the source of emboli. Despite the introduction of hypocoagulative drugs in standard surgical concepts the incidence of deep vein thrombosis remains about 10% in trauma patients. Estimated numbers of unknown cases of pulmonary embolism are supposed to be rather high too. In haemodynamically symptomatic pulmonary embolism events and especially when the patient has to be reanimated, mortality rates of up to 93% are reported in literature. After introduction of the heart- and lung-machine in the surgical concept of therapy, survival rates have increased significantly. We report on three cases of successful surgical embolectomy after CPR. In a review of literature current concepts of treatment in central pulmonary embolism are discussed.

Acetabulum↗

NMR investigation of the multidrug transporter EmrE, an integral membrane protein.

EmrE is an Escherichia coli multidrug transport protein that confers resistance to a wide range of toxicants by active transport across the bacterial cell membrane. The highly hydrophobic polytopic integral membrane protein has been purified and studied in its full-length form by high-resolution NMR spectroscopy in a mixture of chloroform/methanol/water (6:6:1, by vol.). Full activity is maintained after reconstitution of the protein into proteoliposomes from this solvent mixture. A series of heteronuclear (1H-15N) two- and three-dimensional experiments, as well as triple resonance experiments, were applied to the 110-residue protein and led to the assignment of the 1H, 15N and a large part of the 13C backbone resonances as well as many of the sidechain resonances. A preliminary analysis of the secondary structure, based on sequential NOE connectivities, deviation of chemical shifts from random coil values and 3J(NH-H alpha) coupling constants supports a model where the protein forms four alpha-helices between residues 4-26 (TM1), 32-53 (TM2), 58-76 (TM3) and 85-106 (TM4). For the residues of helices TM2 and TM3 a significant line broadening occurs due to slow conformational processes.

Amino Acid Sequence↗

cDNA sequence and expression pattern of the putative pheromone carrier aphrodisin.

The cDNA sequence for aphrodisin, a lipocalin from hamster vaginal discharge which is involved in pheromonal activity, has been determined. Corresponding genomic clones were isolated and the promoter region was identified. Primer extension analysis revealed an adenosine residue as the main transcription initiation site, located 50 bp upstream of the translation start codon ATG, which is surrounded by a typical Kozak sequence. However, data from polymerase chain reaction analysis suggest the existence of at least one alternative transcription initiation site. The aphrodisin cDNA is 732 bp long and codes for the mature 151-aa aphrodisin and an additional N-terminal 16-aa secretory signal peptide. The 3' nontranslated region is 228 bp long. Among the known sequences, the aphrodisin cDNA shares the highest homology with the rat odorant-binding protein cDNA (45%), which verifies the protein data. Vaginal tissue and Bartholin's glands are the main aphrodisin gene-expressing tissues of the female hamster genital tract, as demonstrated by Northern blot analysis. Under less stringent hybridization conditions, RNA isolated from rat Bartholin's glands also showed a signal, indicating the occurrence of aphrodisin-related mRNA in this species.

Amino Acid Sequence↗

Interspecies comparative pathology of colorectal neoplasms: relevance for treatment.

Comparative pathology may serve as a practical tool for therapy by comparison of normal and abnormal structures of the digestive tract in animals and men. A better understanding of colon cancer as the most common solid neoplasm after lung cancer in the industrialized world is sought. In the so-called developed nations and in animals colon cancer is less frequent. The pathogenesis of colon cancer involves environmental and genetic factors. Several types of colorectal cancer can be discerned and the species distribution ranges from invertebrates to man. Colorectal neoplastic progression is species-specific. An intraspecies-specific comparison of large bowel cancer is also valuable. Alteration of signal transduction pathways and somatic mutations of oncogenes are described, as well as the occurrence, research and current treatment. Metastasis of neoplasms of the colon and of the rectum can be studied by intraspecies-specific comparison. Sections of this review deal with vitamin D and cancer and close with present therapies for colorectal cancer.

Animals↗

Role of PCNA in differentiating between malignant mesothelioma and mesothelial hyperplasia: prognostic considerations.

We investigated the PCNA immunoreactivity in 35 specimens of malignant mesothelioma and 20 specimens of mesothelial hyperplasia in order to evaluate the usefulness of this parameter in differentiating between these two mesothelial proliferations, and to determine whether PCNA has any prognostic significance in mesotheliomas. Eleven of the 35 investigated malignant mesotheliomas displayed up to 25% of positive cells for PCNA expression. The remaining 24 specimens showed high percentages of positive cells ranging from 26% to 95%. All specimens of reactive hyperplasia had less than 25% of PCNA positive cells. The difference between malignant mesothelioma and mesothelial hyperplasia for PCNA immunoreactivity was statistically significant (p < 0.01). A positive relationship was also found between PCNA expression level and the overall survival of those affected by malignant mesothelioma (p = 0.0032). Our results suggest on important role for PCNA in differentiating diagnosis of mesothelial proliferations. It remains unclear whether PCNA expression truly correlates with the proliferation rate of the malignant mesotheliomas and with the overall survival of patients affected by this neoplasm.

Adult↗