Search PubMed⌕ Search

Biomedical subjects

M Kraus

Publications and source records attributed to M Kraus.

At least 37 records · Page 2Linked to original sources
PubMed2001

Repair of traumatic inferior orbital wall defects with nasoseptal cartilage.

PURPOSE: This study evaluated the effectiveness of nasoseptal cartilage for repairing traumatic orbital floor defects. PATIENTS AND METHODS: Autogenous septal cartilage was used in 20 patients. They were evaluated for the presence or absence of diplopia, enophthalmus, infraorbital nerve paresthesia, and ocular motility disorders. Surgical indications for orbital exploration included entrapment of orbital tissues, large orbital defect (greater than 50% of the orbital floor or more than 8 mm), or orbital floor defects with involvement of other zygomaticofrontal complex fractures. RESULTS: All patients were successfully treated by restoration of the orbital wall continuity. Follow-up at 1 week to 6 months showed 1 patient with postoperative enophthalmos and 1 patient with lower lid edema. There were no donor site and graft infections or graft extrusion. CONCLUSIONS: Nasal septal cartilage is a readily accessible autogenous tissue that should be considered when an autogenous graft is needed for orbital floor defect reconstruction.

Adolescent↗
PubMed2001

Does high-frequency pseudo-random rotational chair testing increase the diagnostic yield of the eng caloric test in detecting bilateral vestibular loss in the dizzy patient?

OBJECTIVES: To assess the incremental diagnostic yield of testing vestibulo-ocular (VOR) gain with high-frequency pseudo-random rotational chair (PsRRC) over testing with bithermal electronystagmography caloric tests in the dizzy patient, particularly in detecting bilateral vestibular loss. PATIENTS AND METHODS: One hundred ninety-eight patients presenting with dizziness underwent PsRRC and caloric testing. The VOR gain on PsRRC was measured at 0.32 to 5.0 Hz, with gain categorized as normal or decreased. PsRRC results were compared with caloric responses, also categorized as normal, or into graded categories of unilateral or bilateral vestibular loss. RESULTS: Reduced PsRRC gain was found in 29 (15%) patients, and reduced caloric tests responses in 70 (35%), with 25 (13%) having bilateral loss. Of patients with reduced chair gain, 25 of 29 (86%) demonstrated bilateral caloric loss. PsRRC gain was normal in most patients with unilateral caloric weakness, but was decreased in all patients with bilateral caloric weakness. The probability of a patient with completely normal caloric responses having an abnormal rotation chair in this study group was under 1% (1 of 128). CONCLUSIONS: PsRRC testing does not offer much additional diagnostic benefit when caloric responses are normal. It is useful in specific conditions, such as unilateral caloric loss for which the patient is not compensating, borderline caloric loss when traditional water caloric tests cannot be used, or for monitoring progressive bilateral vestibular loss.

Adult↗
PubMed2001

Quantitative assessment of the ischemic brain by means of perfusion-related parameters derived from perfusion CT.

BACKGROUND AND PURPOSE: Besides the delineation of hypoperfused brain tissue, the characterization of ischemia with respect to severity is of major clinical relevance, because the degree of hypoperfusion is the most critical factor in determining whether an ischemic lesion becomes an infarct or represents viable brain tissue. CT perfusion imaging yields a set of perfusion related parameters which might be useful to describe the hemodynamic status of the ischemic brain. Our objective was to determine whether measurements of the relative cerebral blood flow (rCBF), relative cerebral blood volume (rCBV), and relative time to peak (rTP) can be used to differentiate areas undergoing infarction from reversible ischemic tissue. METHODS: In 34 patients with acute hemispheric ischemic stroke <6 hours after onset, perfusion CT was used to calculate rCBF, rCBV, and rTP values from areas of ischemic cortical and subcortical gray matter. Results were obtained separately from areas of infarction and noninfarction, according to the findings on follow-up imaging studies. The efficiency of each parameter to predict tissue outcome was tested. RESULTS: There was a significant difference between infarct and peri-infarct tissue for both rCBF and rCBV but not for rTP. Threshold values of 0.48 and 0.60 for rCBF and rCBV, respectively, were found to discriminate best between areas of infarction and noninfarction, with the efficiency of the rCBV being slightly superior to that of rCBF. The prediction of tissue outcome could not be increased by using a combination of various perfusion parameters. CONCLUSIONS: The assessment of cerebral ischemia by means of perfusion parameters derived from perfusion CT provides valuable information to predict tissue outcome. Quantitative analyses of the severity of ischemic lesions should be implemented into the diagnostic management of stroke patients.

Aged↗
PubMed2001

D-fructose-binding proteins in bull seminal plasma: isolation and characterization.

The heparin-binding activity of bull seminal plasma proteins was inhibited by D-fructose, D-glucose, inulin and glycogen; D-galactose, dextran and mannan had no effect. While the ejaculated sperm-heparin interaction was not influenced by the presence of saccharides, the heparin-binding activity of epididymal sperm was inhibited by D-fructose. The results of the binding studies were confirmed by affinity chromatography on immobilized heparin followed by elution with monosaccharides. Proteins adsorbed to a heparin-polyacrylamide column and eluted with D-fructose were analyzed by RP HPLC, SDS electrophoresis and by determination of the N-terminal amino-acid sequence. RNAase dimer, PDC-109 and metalloproteinase inhibitor (TIMP-2) were identified.

Amino Acid Sequence↗
PubMed2001

[Breed and sex differences in the temperament of calves in a cow-calf operation].

Behavioural traits related to temperament were studied in German Angus (Aberdeen Angus x German dual purpose breeds) and German Simmental cattle. Temperament was defined as the animal's behavioural response to handling. 498 calves (279 German Angus, 219 German Simmental) were tested with two different restrain tests. The animals were tested three times individually during a fixation procedure (days of live: 5, 19, 33) or weighting (days of live: 62, 138, 193). LSQ-means were calculated with a model including breed, year and sex as fixed effects and the sire as a random. Furthermore a regression on the age of the calf was included. Behaviour of the animals were recorded. Significant differences in the recorded parameters were found between the breeds on day 19 and 33 for one test and day 62 for another test. German Angus and male calves were less difficult to handle regarding the different parameters. Both tests could be used to show differences between the breeds.

Age Factors↗
PubMed2000

[Generalized intestinal CMV infection with protein-losing syndrome in ulcerative colitis].

Infection by cytomegalovirus (CMV) in immunocompetent patients is rare, and if it occurs it is most often associated with ulcerative colitis. This case illustrates a CMV infection in a patient with an ulcerative colitis combined with CMV-induced protein losing enteropathy, a condition reported in immunocompetent individuals in only a very few cases worldwide. It demonstrates the importance of differentiating between a flare-up of ulcerative colitis and CMV colitis. The indication for antiviral therapy is discussed. A 76-years-old patient with a 23-year history of leftsided ulcerative colitis presented with acute pancolitis sparing the rectum. He showed no evidence of impaired host defence, nor has he ever had taken immunosuppressive drugs. Disseminated primary CMV infection involving of the colon, the oesophagus and the small intestine with protein losing enteropathy was diagnosed on the basis of histology, culture and serology. In view of the long duration of the illness and the highly active infection, antiviral therapy with ganciclovir was given and led to a dramatical improvement of all disease manifestations. The patient subsequently remained in remission from ulcerative colitis for three years.

Aged↗
PubMed2000

Sperm surface proteins in mammalian fertilization.

Boar seminal plasma was separated into five protein fractions (I-V) (> 100, 55, 45, 30, 5-15 kDa) by gel chromatography on Sephadex G-75 SF at pH 7.2. RP-HPLC of protein fractions I-V and N-terminal sequencing of their individual components revealed that the high-molecular-weight aggregates consisted mainly of DQH sperm surface protein and AQN, AWN, PSP II spermadhesins, whereas fraction IV consisted of heterodimers of PSP spermadhesins only. Spermadhesins as monomers were present in seminal plasma in a very low amount. Aggregates containing the DQH protein and AWN spermadhesins as well as HPLC-separated monomeric proteins interacted strongly with acidic polysaccharides. The strongest interaction was observed between biotinylated glycoproteins of porcine zona pellucida and AWN 1-containing aggregates and separated proteins. PSP II interacted with some acidic polysaccharides, whereas the fraction IV corresponding to heterodimer PSP I/PSP II did not show any binding to acidic polysaccharides and zona pellucida. Aggregates containing AWN, AQN, DQH, PSP II proteins, and their separated monomeric forms (fractions I-III) interacted with phosphorylcholine. Fractions I-III showed affinity to cholesterol. Biotinylated aggregates containing AWN, AQN, DQH, and PSP proteins (fractions I-IV) bound stronger to boar epididymal spermatozoa than to ejaculated spermatozoa. These results suggest that under physiological conditions, the aggregates of seminal plasma proteins (DQH, AQN, AWN, PSP II) rather than the individual proteins might take part in coating the sperm surface, in sperm capacitation, and in primary binding of spermatozoa to zona pellucida of the ovum.

Animals↗
PubMed2000

Characterization of intermolecular beta-sheet peptides by mass spectrometry and hydrogen isotope exchange.

The self-assembly of beta-sheet peptide domains resulting in the formation of fibrillar aggregates (amyloids) is a feature of various neurodegenerative disorders. In order to evaluate mass spectrometric methods for the characterization of intermolecular beta-sheet structures the hydrogen/deuterium exchange behaviour of model peptides DPKGDPKG-(VT)(n)-GKGDPKPD-amide (n = 3,4,5,6,7,8), (VT)(n)-peptides, composed of a central beta-sheet-forming domain and N- and C-terminal nonstructured octapeptide sequences, was measured by electrospray ionization mass spectrometry (ESI-MS) and matrix-assisted laser desorption/ionization mass spectrometry (MALDI-MS). The kinetic analysis of the hydrogen/deuterium exchange (HX) shows that intermolecular beta-sheet structures contain slowly exchanging protons (k </=0.001 1/min). Localization of beta-sheet domains was achieved by monitoring the hydrogen exchange of peptide fragments generated via collision-induced dissociation (CID) or post source decay (PSD). The hydrogen exchange kinetics and the beta-sheet domains determined by ESI- and MALDI-MS were found to correlate with the length and stability of the beta-structure domain of the (VT)(n)-peptides.

Algorithms↗
PubMed2000

Mucosal humoral immune response to CagA shows a high prevalence in patients with gastric MALT-type lymphoma.

In the pathogenesis of gastric mucosa-associated lymphoid tissue (MALT)-type lymphoma, CagA-positive Helicobacter pylori strains have been suspected of making a significant contribution. To investigate this hypothesis in more detail, the mucosal humoral immune response of 15 patients with gastric MALT-type lymphoma was examined in the tumor and in the tumor-free gastritis of the same patient. Mononuclear cells from different sites (antrum, corpus, lymphoma) were cultured. Culture supernatant and serum of the same patient were used for immunodetection of CagA. All patients displayed an immune response to CagA in the tissue-culture supernatants. Although the humoral immune response in the tumor was restricted to a very few H. pylori antigens, antibodies directed against CagA protein were found in most patients. The immune response to CagA in nearly all lymphoma patients--not only in the serum, but also in the mucosa, including the tumor site--support the hypothesis that CagA is involved in the pathogenesis of gastric MALT-type lymphoma.

Antibody Formation↗
PubMed2000

[Cooperative procedures between endoscopy, laparoscopy. intervention and laparotomy in palliation].

Within the framework of interdisciplinary palliative treatment strategies for gastrointestinal neoplasms, surgical therapeutic options are of essential importance. They are dominated by the reconstruction of the gastrointestinal passage, ensuring drainage of secretion and the alleviation of pain. Conventional, minimal-invasive and endoscopic procedures are employed individually or in a combined way, integrating all conservative therapies. In many cases, an unnecessary laparotomy with its high morbidity, mortality and prolonged hospitalisation can thus be avoided. This paper describes and discusses current surgical and endoscopic techniques for the palliative treatment of patients suffering from advanced gastrointestinal malignant tumours.

Gastrointestinal Neoplasms↗
PubMed2000

The basal ganglia in haemochromatosis.

Haemochromatosis is characterised by deposition of iron-containing pigment in various organs, but little is known about possible deposition in the brain and its clinical impact. We therefore investigated 14 patients with hereditary haemochromatosis with MRI, CT and transcranial ultrasound (TCS) and examined them neurologically. In six of the patients dense lesions were found within the lentiform nucleus on CT, all of whom displayed hyperechogenic lesions in the same area on TCS, as did one other patient. In these patients the relative signal intensities of the lentiform nucleus measured by MRI relaxometry were higher. No patient had clinical signs of basal ganglia disorders.

Adult↗
PubMed2000

Non-invasive measurement of cell membrane associated proton gradients by ion-sensitive field effect transistor arrays for microphysiological and bioelectronical applications.

The pH in the cellular microenvironment (pH(M)) is an important regulator of cell-to-cell and cell-to-host interactions. Additionally the extracellular acidification rate of a cell culture is an important indicator of global cellular metabolism. In a new approach a biocompatible ion-sensitive field effect transistor (ISFET)-array was developed to measure the pH(M) close to a surface and the global extracellular acidification rate at the same time. This ISFET-array is part of a new multiparametric microsensor chip. The paper highlights some basic applications of this method for in-vitro measurements. Using a fluid perfusion system for cell culture media, it is possible to measure the pH(M) of few (five to ten) adherent tumor cells in a distance of 10-100 nm from the cell plasma membrane. Experiments showed a pH(M)-value of 6.68 +/- 0.06 pH. Further experiments suggest that both the low pH, and the extracellular acidification rate of the examined tumor cell line are mainly built up by glycolysis.

Biosensing Techniques↗
PubMed2000

CXC chemokines Gro(alpha)/IL-8 and IP-10/MIG in Helicobacter pylori gastritis.

Infection with Helicobacter pylori causes chronic active gastritis, which is characterized by neutrophils infiltrating the gastric epithelial layer and the underlying lamina propria as well as by T, B lymphocytes and macrophages accumulating in the lamina propria. In this study, the chemokine profile responsible for the recruitment of these inflammatory cells is investigated. Using both RNA/RNA in situ hybridization and immunohistochemistry, the expression of the neutrophil and/or lymphocyte-attractant CXC chemokines growth-related oncogene alpha (Gro(alpha)), IL-8, interferon-gamma (IFN-gamma)-inducible protein-10 (IP-10), monokine induced by IFN-gamma (MIG) and the CC chemokines macrophage inflammatory protein-1alpha (MIP-1alpha), -1beta, regulated on activation normal T cell expressed and secreted (RANTES) and monocyte chemoattractant protein-1 (MCP-1) is studied and microanatomically localized in the gastric mucosa. Macrophages in the lamina propria at sites with neutrophil infiltration and gastric epithelium infiltrated by neutrophils highly expressed the neutrophil-attractant chemokines Gro(alpha) and IL-8. Additionally, Gro(alpha) and IL-8 were expressed by neutrophils themselves localized within gastric epithelium, in the foveolar lumen and in the cellular debris overlying mucosal erosion. IP-10 and to a lower extent MIG, both selectively chemotactic for inflammatory T cells, were expressed by endothelial cells of gastric mucosal vessels and by mononuclear cells at sites with T cell infiltration. Expression of all other CC chemokines tested was significantly lower. These in vivo data indicate that a set of predominantly CXC chemokines modulates the inflammation in H. pylori gastritis. Gro(alpha) and IL-8 may play an important role in neutrophil trafficking from the mucosal vessel into the gastric epithelium, whereas IP-10 and MIG contribute to the recruitment of inflammatory T cells into the mucosa.

Chemokine CCL2↗
PubMed2000

Authors' reply.

Explore the source record for details and available documents.

Journal Article↗
PubMed2000

[CT perfusion imaging in acute ischemic cerebral infarct: comparison of cerebral perfusion maps and conventional CT findings].

PURPOSE: To evaluate the findings of acute brain ischemia on different functional maps of cerebral perfusion CT in stroke patients and to compare the results with early ischemic changes on conventional CT. METHODS: The baseline CT scans of 45 acute stroke patients were retrospectively evaluated with respect to early CT findings. For each patient the extent of cerebral ischemia as shown on the maps of cerebral blood flow (CBF), cerebral blood volume (CBV), and "time to peak" (TP) was compared and the severity of ischemia was assigned to one of three levels based on the findings of the CBF image. RESULTS: In 75% of all patients conventional CT was performed within 2 hours from symptom onset. 29 of 45 patients showed early signs of ischemia on conventional CT, whereas perfusion CT revealed cerebral ischemia in all patients. Severe ischemia was found in approximately the same rate of incidence in patients with early CT changes (55.2%) and in those with normal findings (43.8%). If the perfusion impairment was judged as mild or moderate the extent of the hypoperfused area was significantly larger on the CBF and TP images than on the CBV map. This was significantly different in patients with severe hypoperfusion where a complete correspondence of the affected area between the three functional maps was found. DISCUSSION: The use of conventional CT for the assessment of stroke in the hyperacute phase is limited. Perfusion CT yields excellent information regarding the severity and extent of ischemia. The use of various perfusion maps helps to differentiate the core of infarction from the ischemic penumbra zone.

Acute Disease↗
PubMed2000

High incidence of posttransplant lymphoproliferative disease in pediatric patients with cystic fibrosis.

A major cause of morbidity and mortality following lung transplantation is posttransplant lymphoproliferative disease (PTLD). In a retrospective cohort analysis of pediatric patients, we evaluated the risk factors associated with PTLD in 128 first-time lung transplant recipients from 1990 to 1997. The greatest risk factor for PTLD was a diagnosis of cystic fibrosis (CF). Of the 16 patients in our analysis who had PTLD, 13 had a diagnosis of CF (odds ratio [OR]: 5.8; confidence interval 95% [CI]: 1.6 to 21.4). Because of the high frequency of PTLD in patients with CF (13 of 61; 23%), we performed a retrospective cohort analysis in which patients with CF and PTLD were designated as cases and patients with CF and without PTLD served as controls. In patients with CF, the only risk factor associated with PTLD was two or more episodes of acute rejection within 3 mo after transplantation (OR: 11.0; 95% CI: 2.7 to 55.7). Age, recipient Epstein-Barr virus or cytomegalovirus status, induction with antilymphocyte globulin or antithymocyte globulin (ATG), or use of ATG or OKT3 for acute rejection episodes were not risk factors for PTLD. The high frequency of PTLD in the subgroup of patients with two or more episodes of graft rejection within 2 mo after lung transplantation was unexpected, and warrants further investigation in prospective clinical studies and basic laboratories.

Adolescent↗
PubMed2000

Characteristics and prognosis of myocardial infarction in patients with normal coronary arteries.

STUDY OBJECTIVES: Myocardial infarction with angiographically normal coronary arteries (MINC) is a life-threatening event with many open questions for physicians and patients. There are little data concerning the prognosis for patients with MINC. DESIGN: Retrospective follow-up study. SETTING: Tertiary referral center. PATIENTS: Patients with MINC were investigated and compared to age- and sex-matched control subjects with myocardial infarction due to coronary artery disease (CAD). The patients were examined clinically using stress exercise and hyperventilation tests. Migraine and Raynaud's symptoms were determined by means of a standardized questionnaire. Serum lipoproteins; the seroprevalence of cytomegalovirus, Helicobacter pylori, and Chlamydia pneumoniae infections; and the most frequent causes of thrombophilia were assessed. MEASUREMENTS AND RESULTS: From > 4,300 angiographies that were performed between 1989 and 1996, 21 patients with MINC were identified. The mean +/- SD patient age at the time of myocardial infarction was 42 +/- 7.5 years. When compared to control subjects (n = 21), patients with MINC had fewer risk factors for CAD. In contrast, MINC patients had more frequent febrile reactions prior to myocardial infarction (six patients vs zero patients; p < 0.05), and the migraine score was significantly higher (7.1 +/- 6.3 vs 2.2 +/- 4.1; p < 0.01). The seroprevalence of antibodies against cytomegalovirus, C pneumoniae, and H pylori tended to be higher in patients with MINC and CAD as compared to matched healthy control subjects. Three patients with MINC vs none with CAD had coagulopathy. During follow-up (53 +/- 37 months), no major cardiac event occurred in the MINC group; no patients with MINC vs nine with CAD (p = 0.0001) underwent repeated angiography. CONCLUSION: High migraine score and prior febrile infection together with a lower cardiovascular risk profile are compatible with an inflammatory and a vasomotor component in the pathophysiology of the acute coronary event in MINC patients. The prognosis for these patients is excellent.

Adult↗