Biomedical subjects
Publications and source records attributed to G Schmidt.
Between 1987 and 1991, we operated on 13 patients with 14 palmar space infections of the hand. Twelve of them were evaluated after a mean follow up of 33 months. Analysis points out the importance of early and sufficient surgical intervention. Seven out of ten cases showed a good or very good result, three ending with a fair result.
Differential screening of a murine RNA-based lambda gt10 cDNA library with cell cycle phase-specific probes released a cDNA clone (lambda GS1) to a mRNA (1.8 kb) which is prevalent in the S phase of the cell cycle. The nucleotide sequence of the cDNA predicts a protein (RNPS1, 41 x 10(3) M(r) with two nucleic acid-binding domains separated by a proline-rich spacer. The N-terminal nucleic acid binding domain, about 80 amino acid residues in length, meets the requirements of an RNA recognition motif (RRM) including a perfect 'RNP-1 octamer'. The C-terminal nucleic acid binding domain spanning over 26 amino acid residues is prominent because it comprises three copies of the RRRS peptide. Domains of the latter type are considered to be involved in RNA and DNA-binding because comprised in many RNA and DNA-binding proteins.
A 44-year-old man, apparently without heart disease, suddenly collapsed with loss of consciousness. Ventricular fibrillation was documented when an external defibrillator was connected. After cardiopulmonary resuscitation and intubation he quickly regained consciousness. Clinical examination together with echocardiography, coronary angiography and electrophysiological tests discovered no abnormalities. Biochemical tests were normal except for slightly abnormal liver functions. Several long-term ECG recordings documented asymptomatic S-T elevations. During one such episode there occurred a polymorphous ventricular tachycardia of brief duration. Because the S-T elevations persisted, despite the administration of gallopamil (50 mg twice daily for one week), a defibrillator was implanted. Gallopamil was then discontinued. Long-term ECG monitoring subsequently revealed four episodes of marked S-T elevations, three of which accompanied by ventricular arrhythmias. After resuming gallopamil, now at a dose of 50 mg three times daily, further ECG monitoring showed no abnormalities.
Twelve years after adnexectomy, performed for actinomycosis of the left ovary, a 32-year-old woman developed abdominal and back pain. A solid tumour was palpated in the left lower abdomen. Colon contrast examination revealed a subtotal stenosis in the sigmoid colon, while sonography showed a complete stenosis of the left ureter with left hydronephrosis. Relaparotomy demonstrated a stone-hard tumour at the rectosigmoid junction, which involved the right ovary and ureter, as well as having infiltrated the retroperitoneum, predominantly on the left. After resection of the sigmoid colon, uterus and right ovary, as well as of the ureteric stenosis with reanastomosis, the further course was without complication. Histological examination confirmed actinomycosis of the left ovary, sigmoid colon and pelvic mesocolon. Therapy with amoxycillin, 500 mg three times daily, was started. As the patient had worn an intrauterine pessary for several years, primary infection of the uterus with spread into the abdominal cavity via tube and ovaries is likely to have been the course of events. The recurrence was probably caused by reactivation of residual actinomycetes in the retroperitoneum and pelvic mesocolon.
Despite recent progress in improving diagnostic methods carpal bone lesions are still a major problem of primary diagnosis. Diagnostic imaging with digital luminescence radiography (DLR) allows the reliable presentation of traumatologically relevant carpal structures. In this study on 39 patients with suspected carpal bone injuries individually worked over DLR images were superior to "standard" DLR and conventional X-ray film/screen images. Though "standard" DLR images were inferior to film images edge-enhanced DLR images showed definite advantages in the demonstration of soft tissues. Fractures undetectable in conventional X-rays could not be recognized by digital imaging. In our experience bone-scanning remains the most reliable method for definite exclusion of carpal bone fractures after standard and digital X-ray methods are exhausted.
Lipopolysaccharides (LPS) constitute the O-antigens and endotoxins of Gram-negative bacteria. Whereas both the polysaccharide and lipid portion of LPS contribute to the pathogenic potential of this class of bacteria, it is the lipid component (lipid A) which determines the endotoxic properties of LPS. The primary structure of lipid A of various bacterial origin has been elucidated and Escherichia coli lipid A has been chemically synthesized. The biological analysis of synthetic lipid A partial structures proved that the expression of endotoxic activity depends on a unique structural arrangement and conformation. Such analyses have furthermore provided insight into the determinants required for lipid A binding to and activation of human target cells. Present research efforts aim at the molecular characterization of the specificity, modulation and biomedical consequences of the interaction of lipid A with host cells.
The adhesion of Escherichia coli to host epithelial cells is the very first step of urinary tract infections followed by the internalization of some bacteria into these cells. These steps are influenced by several surface antigens or products of the pathogen, e.g. fimbriae or adhesins, K antigen, and hemolysin. The bacterial adherence and the internalization of several mutants of an E. coli O18:K5 strain differing in the expression of K5 antigen, hemolysin, and fimbriae were measured using a permanent line of porcine tubuloepithelial cells (LLC-PK1). Strains with K5 antigen were reduced in adherence and internalization in comparison to the K-negative strains. The expression of hemolysin by these strains lead to an increase of adherence and internalization. The internalization of bacteria is influenced mainly by their adherence to the epithelial cells. Thus, the internalization of attached bacteria is rather a kind of endocytosis than an invasion of the bacteria. To confirm this thesis, we investigated the influence of cytoskeletal inhibitors (cytochalasine B, cytochalasine D, colchicine, and chloroquine) on bacterial adherence and internalization. The cytoskeletal inhibitors lead to a significant inhibition of internalization of the bacteria tested. The receptor-mediated endocytosis of bacteria by tubuloepithelial cells may be of importance in the pathogenesis of recurrent urinary tract infection.
Chlamydiae possess a genus-specific epitope that is located on the lipopolysaccharide (LPS) and is composed of a 3-deoxy-D-manno-octulosonic acid (Kdo) trisaccharide of the sequence alpha Kdo-(2-->8)--alpha Kdo-(2-->4)-alpha Kdo. In Chlamydia trachomatis, this trisaccharide is biosynthetically generated through the action of a multi-functional Kdo-transferase encoded by the gene gseA. gseA of Chlamydia psittaci 6BC was cloned and expressed in a rough mutant (Re chemotype) of Escherichia coli (strain F515) that contains an LPS with only two alpha 2-->4-linked Kdo residues. Recombinant strains were able to add the immunodominant Kdo residue in alpha 2-->8-linkage to the parental LPS, as determined by SDS-PAGE and Western blot analysis using a monoclonal antibody against the genus-specific epitope. The DNA sequence of gseA was determined and aligned to that published recently for C. trachomatis serovar L2. Most surprisingly, the two deduced amino acid sequences shared only an overall homology of 67%. Thus, gseA exhibits species specificity at the DNA level, whereas its gene product results in the synthesis of a carbohydrate antigen with genus specificity.
1. When stimulating the local nerves in the bovine ovarian follicle wall preparation (4 Hz, 1 ms pulse duration and 7.5 V between the electrodes) vasoactive intestinal polypeptide reduced the neurogenic contraction and at the highest concentration tested (3 x 10(-7) M) almost abolished the response. Peptide histidine isoleucine only slightly reduced the contraction. 2. Strips from the follicle wall of bovine ovaries were incubated in Krebs-Ringer solution containing [3H]-noradrenaline for measurement of transmitter liberation during electrical field stimulation (5 Hz frequency, 1 ms pulse duration, 10 V between the electrodes). Vasoactive intestinal polypeptide had no effect on the electrically induced efflux of radioactivity. 3. Vasoactive intestinal polypeptide and its related peptide, peptide histidine isoleucine, relaxed precontracted follicle strips dose dependently with I(max) at 3 x 10(-7) M of 60% and 40% respectively. 4. Vasoactive intestinal polypeptide 10(-7) M did not alter the EC50 value of the noradrenaline-(10(-9)-10(-4) M) or carbachol-induced (10(-8)-3 x 10(-4) M) contraction in the follicle strips, but significantly reduced the E(max) value of the noradrenaline but not the carbochol-mediated contraction. 5. These results suggests that vasoactive intestinal polypeptide, and to some extent peptide histidine isoleucine, have a postjunctional role in ovarian follicle contractility and might further interfere with the ovulatory process.
In experiments on anesthetized rabbits the kinetics of capillary plasma filling in the heart during normoxemia and hypoxemia were studied. Three gamma globulins originating from three different species were infused into the left atrium for various periods of time. The hearts were shock frozen, and the respective globulins were immunohistochemically identified in parallel sections. The anatomic capillary density was determined by staining the capillary basement membrane. During normoxemia 69 and 66% (subepicardium and subendocardium, respectively) of the capillaries were labeled within 2 s, 84 and 78% within 5 s, and 96 and 92% within 10 s. Labeling was complete after 20 s. Hypoxemia (arterial PO2 27 mmHg, 5 min) led to a significant acceleration of capillary filling kinetics: 93 and 95% within 2 s, 98 and 99% within 5 s, 100 and 99% within 10 s. During hypoxemic conditions the entire left coronary flow was found increased by a factor of 2.3. The data may best be explained by the fact that hypoxemia does not lead to mobilization of previously nonperfused capillaries but induces either an amplification of capillary flow velocities or an increased frequency of periods with high capillary blood flow.
During to the nature of its anatomical locations the median nerve is the nerve most often and most severely affected in compartment syndromes. In our controlled prospective study of 59 patients with distal fractures of the radius, critically high pressure was recorded in the carpal tunnel even in sites of moderate soft tissue swelling. The increase in pressure is directly related to the extent of fracture hematoma, the interval between injury and treatment, and the amount of manipulation during reduction. The average pressure within the carpal tunnel of a normal wrist joint held in the neutral position is 5 mm Hg. In contrast, the average carpal tunnel pressure in the distal radius fracture group in this study was increased to 24 mmHg. During reduction average pressures increase to 44 mmHg, subsequently decrease for a brief period, and finally increase to 34 mmHg 4 h later. At 12 h after reduction average values are still 26 mm Hg. Patients developing Sudeck's dystrophy during treatment (n = 4) exhibit above-average carpal tunnel pressure.
This study is focused on the academic and clinical career of Max Neuburger (1868-1955), who founded the Institute for the History of Medicine at the University of Vienna in 1914. Yet unpublished documents are used to illustrate this development.
Prevention of recurrences of atrial fibrillation, slowing the ventricular rate during atrial fibrillation, and the acute management of atrioventricular junctional reentrant supraventricular tachycardia (paroxysmal supraventricular tachycardia) often require treatment with antiarrhythmic drugs. These drugs comprise a pharmacodynamically and pharmacokinetically heterogeneous group of agents whose individual properties determine correct use, contraindications and side effects. Stabilisation of sinus rhythm can be achieved with class IA and class IC sodium channel blocking drugs as well as with the class III agents amiodarone or sotalol. Verapamil, diltiazem, cardioselective beta-adrenoceptor-blocking drugs or cardiac glycosides can be used to slow the ventricular rate during atrial fibrillation. Rapid termination of paroxysmal supraventricular tachycardia is achieved with i.v. administration of adenosine, verapamil, ajmaline, diltiazem, propafenone, or flecainide. If atrial flutter complicates the preexcitation syndrome, this type of supraventricular tachycardia must not be treated with calcium antagonists, cardiac glycosides or lidocaine, since these agents decrease refractoriness of the accessory pathway which may precipitate fatal ventricular fibrillation.
We studied retrospectively the clinical records of 291 hospital patients with liver cirrhosis, 95% of which was alcohol related. Within this group, 114 patients presented 155 episodes of infection in 144 separate hospital admissions. In a previous communication, we pointed out that although infection was the fourth cause of admission, it was the main cause of death in this group. The main incidence of infection was among the female group. The most common infections episodes were respiratory and bacterial spontaneous peritonitis (BSP). On admission, 57% of the patients were diagnosed as belonging to the C Child group; 38% presented sepsis and 22% were hospitalary infections. The most frequent infections were respiratory and BSP. We obtained bacteriologic documentation in 55% of the episodes with prevalence of Gram negative bacilli (E. coli), with high relative frequency of neumoccocus. The most frequent complications were related to hepatic insufficiency. Global death rate was 27.1%, while nosocomial death rates were 42.1% and 40.9% for patients with Child C. We observed the highest incidence of mortality in patients with SBP and non localized bacteriemia. Survival rates were 42% for 2 years and 18% for 5 years. In summary, we stress the relevancy of checking the presence of infection systematically in every cirrhotic patient with encephalopathy and/or renal insufficiency without justifiable cause.
Gram-negative bacteria carry on their surface endotoxins, which are essential for bacterial growth and survival. If released from the bacterial cell, endotoxins induce in higher organisms a great variety of pathophysiological effects. Chemically, endotoxins constitute lipopolysaccharides (LPS), the lipid component (termed lipid A) of which is responsible for the induction of endotoxin effects. The structural and conformational parameters, endowing lipid A with its potent bioactivity, have been well characterized. The toxic effects of endotoxins are initiated by the specific interaction of lipid A with macrophages/monocytes resulting in the production of peptide or lipid mediators. This interaction is governed by a unique (toxic) conformation of lipid A on the one hand, and by specific cellular receptors on the other. The interaction and subsequent mediator production can be specifically and antagonistically inhibited by lipid A partial structures. A recently developed monoclonal anti-LPS-antibody cross-reacts with endotoxins of various bacterial origin, and it cross-protects against harmful endotoxin effects such as pyrogenicity and lethality.
The light-harvesting pigment-protein complex B-phycoerythrin from the red alga Porphyridium sordidum has been isolated and crystallized. B-Phycoerythrin consists of three different subunits forming an (alpha beta)6 gamma aggregate. The three-dimensional structure of the (alpha beta)6 hexamer was solved by Patterson search techniques using the molecular model of C-phycocyanin from Fremyella diplosiphon. The asymmetric unit of the crystal cell (space group P3, with a = b = 111.2 A, c = 59.9 A, alpha = beta = 90 degrees, gamma = 120 degrees) contains two (alpha beta) monomers related by a local dyad. Three asymmetric units are arranged around the crystallographic 3-fold axis building an (alpha beta)6 hexamer, as in C-phycocyanin. The crystal structure has been refined by energy-restrained crystallographic refinement and model building. The conventional R-factor of the final model was 18.9% with data to 2.2 A resolution. The molecular structures of the alpha and beta-subunits resemble those of C-phycocyanin. Major changes in comparison to phycocyanin are caused by deletion or insertion of segments involved in protein-chromophore interactions. The singly linked phycoerythrobilin chromophores alpha-84, alpha-140a, beta-84 and beta-155 are each covalently bound to a cysteine by ring A. The doubly linked chromophore beta-50/beta-61 is attached at cysteine beta-50 through ring A and at cysteine beta-61 through ring D. B-Phycoerythrin contains additionally a 30 kDa gamma-subunit, which is presumably located in the central cavity of the hexamer. It is disordered, as a consequence of crystal and local symmetry averaging.
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Four bacteriophages recognizing the Escherichia coli capsular antigens K3, K7, K12, and K13, respectively, were isolated from pooled sewage samples. The nucleic acid of these phages was identified as double-stranded DNA of different size (phi K3, 71.3; phi K7, 32.8; phi K12, 42.9; phi K13, 43.4 kbp). Three of these phages belonged to Bradley's morphology group C and were specific for K3, K7, and K12 antigens, respectively. The phage phi K13 (Bradley's group A) attacked not only E. coli K13 strains but also E. coli producing the closely related K20 and K23 antigens. It is suggested that the common basic repeating units occurring in these capsular polysaccharides are the primary receptor of phi K13. It could be demonstrated that the four phages were able to depolymerize enzymatically the capsular polysaccharides isolated from the respective host strains.