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Biomedical subjects

M Kraus

Publications and source records attributed to M Kraus.

At least 109 records · Page 6Linked to original sources
PubMed1995

The value of complement activation products in the assessment of systemic lupus erythematosus flares.

Complement activation products (CAP) have been reported as sensitive markers of disease activity in systemic lupus erythematosus (SLE). We have measured seven parameters of the complement system (C3, C4, factor B, C3a, C4a, iC3b, and the terminal complement complex-TCC-) in 61 SLE patients to study their interrelationship and relative efficacy as diagnostic indicators of lupus activity. Disease activity was judged according to a clinical index (SLEDAI) to be active in 22 and inactive in 39 patients. Subjects with active SLE showed increased levels of C3a, C4a, and TCC compared with those of stable lupus and normal controls, and plasma concentrations of these CAP manifested a positive correlation with disease activity scores. However, values of factor B and iC3b did not correlate with lupus flares. Serum C3 levels were a better reflection of the degree of SLE activity than were C4 levels. The anaphylatoxins were extremely sensitive markers of disease activity but they lacked enough specificity, and iC3b was not at all informative for this purpose. On the whole, TCC concentration was the most useful parameter (77% sensitivity, 80% specificity) to monitor lupus activity, correlating the best with the activity scoring system, and thus offers a better laboratory marker of lupus severity than conventional measurements of complement.

Adolescent↗
PubMed1995

Water-soluble poly(acrylamide-allylamine) derivatives of saccharides for protein-saccharide binding studies.

Water-soluble poly(acrylamide-allylamine) copolymers containing covalently bound amino groups, prepared by copolymerization of acrylamide and allylamine, can be used as general carriers for coupling of different types of saccharides or saccharide derivatives. The water-soluble macromolecular carbohydrate derivatives can be easily labelled and used in various solid-phase techniques to study protein-saccharide interaction. Two types of coupling reaction were used to prepare polyacrylamide derivatives of saccharides: reductive amination was applied to couple the reducing disaccharides and a carbodiimide reaction was used to couple heparin via its carboxyl groups to the amino groups of the poly(acrylamide-allylamine) derivative. Peroxidase labelled or biotinylated derivatives were shown to be useful in studies on the binding properties of lectins and proteins from boar seminal plasma.

Acrylic Resins↗
PubMed1995

The dementia of Gerstmann-Sträussler-Scheinker syndrome: clinical variability demonstrated by two case reports.

Two cases of Gerstmann-Sträussler-Scheinker syndrome (GSS) are discussed in detail. These cases illustrate the variable clinical course and mostly cortical features of GSS-associated dementia. Given the availability of genetic tests that can now diagnose GSS, clinicians should consider these tests in cases where patients with dementia have extensive family histories or if the clinical course is atypical for Alzheimer's or vascular dementia.

Adult↗
PubMed1994

Complications in endoscopy of the lower gastrointestinal tract. Therapy and prognosis.

This is a report on 126 prospectively registered and controlled complications in 29,695 consecutive endoscopic procedures of the lower gastrointestinal tract. The overall complication rate is 0.4%. All endoscopic procedures were performed in our institution; no referrals "from other hospitals" are included. The therapy and prognosis of occurring complications are described. Especially after therapeutic endoscopy--above all, after polypectomy--the complication rate of 0.83% is not negligible. A serious aspect is the average interval of 30 h from endoscopically caused complication to the onset of symptoms. Bleeding could be managed conservatively in 76% of cases. Nevertheless perforation and transmural burn injuries required surgical intervention in 78% of cases. The authors conclude that in the case of transmural burn an attempt at "active conservative treatment" is justified if the patient is under close surgical control, if the symptoms improve, and if there is a possibility of immediate surgery.

Adult↗
PubMed1994

Ising model for cooperative processing of extracellular information by protein-tyrosine kinases and cell adhesion molecules.

Activation of receptor tyrosine kinases by multiple growth (GFs) is a major process through which mitogenic information is transmitted into cells. Cell cycle progression additionally requires the coordinated interaction of cellular adhesion receptors with extracellular matrix (ECM) molecules. Recent data from several groups, which demonstrated that integrin-ECM contacts promote multiple phosphorylations of intracellular components although the integrin cytoplasmic domains do not have intrinsic protein kinase activity, support the theory that some adhesion receptor families transduce extracellular signals cooperatively with protein-tyrosine kinases (PTKs). Based on the well-established hypothesis that adhesion receptors induce an aggregation of PTKs through a rearrangement of the cytoskeleton, a mathematical minimal model for the regulation of PTKs is presented which accounts for the synergism between different environmental signals mediated by growth factors and cell adhesion molecules (CAM) or cell adhesion associated substances like carcinoembyronic antigen (CEA). The model, which is closely related to a two-dimensional Ising model describing order-disorder transitions in ferromagnetic crystals, provides evidence that a cell-type-specific pattern of cell adhesion molecules may function as a molecular amplifier which promotes the metastatic activity of malignant tumor cells through the indirect induction of intracellular PTK activity.

Animals↗
PubMed1994

Autoantibodies to annexins: a diagnostic marker for cutaneous disorders?

Annexins/lipocortins are a group of structurally related calcium and lipid binding proteins which have been implicated as mediators of the anti-inflammatory action of corticosteroids. Autoantibodies against annexin-1 have been reported in association with autoimmune diseases such as systemic lupus erythematosus and rheumatoid arthritis and their presence has been hypothesized as the reason for the steroid resistance phenomenon. In this study we investigated IgG- and IgM-autoantibodies against annexin-1,-2,-3,-4,-5 and -6 in sera of 221 patients with skin disorders and 114 healthy blood donors with newly established ELISAs. Patients were clustered into 5 groups according to their diagnosis: autoimmune diseases, psoriasis, leg ulcer, malignant melanoma, and miscellaneous diseases. Autoantibodies directed against each annexin were detectable in all investigated groups, in the control group as well as in the disease groups, without displaying any significant correlation to any of the disease states. The homogenous distribution of annexin-autoantibodies throughout the control group and all the disease groups studied, do not support the implication of annexin-autoantibodies in pathophysiological states and make them an unlikely candidate for use as a diagnostic marker.

Adult↗
PubMed1994

Ulcerative colitis and Crohn's disease: factor XIII, inflammation and haemostasis.

An important role has been ascribed to plasma factor XIII (FXIII) in inflammation and wound healing. FXIII is necessary for fibrin stabilization and interacts with connective tissue and adhesive proteins and cells. In a prospective study, FXIII activity and parameters of coagulation, fibrinolysis and inflammation, were determined in patients with ulcerative colitis (UC; 13 active, 22 moderate) and Crohn's disease (CD; 36 active, 45 moderate). FXIII levels were lower in active than in moderate UC and CD, and were < 70% of normal values in 7/13 patients with active UC, and in 7/36 patients with active CD, although the median values did not fall below the normal range. FXIII was somewhat higher in active UC patients responding to therapy. The FXIII levels were widely scattered, and low values appear to be due to greatly enhanced turnover. A correlation between FXIII and the systemic levels of markers of activation of haemostasis and inflammation was lacking, but there was a correlation with the extent of bowel involvement. FXIII levels were lower in the patients with involvement beyond the sigmoid colon in CU (p = 0.0045), and both small and large bowel segments in CD (p = 0.0223) patients. This points to local consumption and/or loss of FXIII within the inflamed tissue, and provides an argument for FXIII substitution in the treatment of acute episodes of inflammatory bowel diseases.

Adolescent↗
PubMed1993

Systems analysis in cell biology: from the phenomenological description towards a computer model of the intracellular signal transduction network.

In this paper we introduce a systematic approach for the modelling of complex biological systems which is especially useful for the analysis of signal transduction mechanisms in cell biology. It is shown that systems analysis in form of top-down levelled dataflow diagrams provides a powerful tool for the mathematical modelling of the system in terms of a stochastic formulation. Due to the exact formulation, the consistency of the model with the experimental results can be tested by means of a computer simulation. The method termed Structured Biological Modelling (SBM) is illustrated by modelling some aspects of the second messenger network which regulates cell proliferation. As an example for the straightforward development of a mathematical description a stochastic computer model for intracellular Ca2+ oscillations is presented.

Animals↗
PubMed1993

[Intracranial complications of otorhinologic infections].

In 70 patients with initial otorhinological infections there were 87 different central nervous system (CNS) complications. 40 (57%) were children (from 1 month to 15 years). 15 (21%) had more than 1 complication. Mortality was 14% (10/70). Leptomeningitis was the most common CNS complication (43%) and it occurred mainly in the pediatric age group. Lateral sinus thrombosis (LST) was accompanied by other intracranial infections in 80% of the patients. The highest mortality was found in patients with brain abscess (38%) as the initial or concomitant complication. Despite liberal use of antibiotics, CNS complications of otorhinologic infections are still encountered with considerable mortality rates. Modern imaging techniques are of great value in localizing the intracranial disease, but a complete initial otorhinologic examination is needed to rule out an extracranial focus of infection, sometimes with an insidious course.

Adolescent↗
PubMed1993

[Importance of cell self-organization for tumor biology].

A cell is a complex system working far from thermodynamic equilibrium. The prediction of cellular functions based exclusively on the molecular basis is yet impossible because of the many degrees of freedom of the microsystem cell. In contrast, the system cell displays only a surprisingly small spectrum of macroscopic observable degrees of freedom, the number of which changes during the cell cycle and neoplastic growth. Illustrated by image analytical and cell biological data we attempt to describe these phenomena of cellular self-organization.

Animals↗
PubMed1993

The effect of Leboyer delivery on blood viscosity and other hemorheologic parameters in term neonates.

OBJECTIVE: This study was done to compare postnatal alterations in blood viscosity, hematocrit value, plasma viscosity, red blood cell aggregation, and red blood cell deformability in term neonates undergoing both early umbilical cord clamping and delivery according to the Leboyer method. STUDY DESIGN: The umbilical cords of 15 healthy, term infants were clamped within 10 seconds of birth (early cord clamping), and 15 infants delivered according to the Leboyer method were placed on the mother's abdomen, and the umbilical cords were clamped 3 minutes after birth. Hemorheologic parameters were studied in umbilical cord blood at 2 hours, 24 hours, and 5 days from the time of delivery. RESULTS: The residual fetal placental blood volume decreased from 45 +/- 8 ml/kg (x +/- SD) after early cord clamping to 25 +/- 5 ml/kg after delivery by the Leboyer method. After Leboyer-method delivery, the hematocrit value rose from 48% +/- 5% at birth to 58% +/- 6% 2 hours after delivery, 56% +/- 7% at 24 hours, and 54% +/- 8% after 5 days. Blood viscosity in the Leboyer-method group increased by 32% within the first 2 hours but did not change significantly during the following 5 days. Plasma viscosity, red blood cell aggregation, and red blood cell deformability were not affected by the mode of cord clamping. CONCLUSIONS: Delivery by the Leboyer method leads to a significant increase in blood viscosity as a result of increasing hematocrit value, whereas other hemorheologic parameters are similar to those of infants with early cord clamping.

Blood Viscosity↗
PubMed1993

Activation of coagulation and fibrinolysis in patients with lung cancer: relation to tumour stage and prognosis.

Activation of coagulation and fibrinolysis within tumour tissues is thought to be associated with tumour growth, angiogenesis, and metastasis. The plasma levels of markers of thrombin and plasmin generation are sensitive tools for monitoring activation of coagulation and fibrinolysis. We studied 47 patients with histologically confirmed lung cancer, 15 with small cell (SCLC) and 32 with non-small cell lung cancer (NSCLC). The plasma levels of the following markers were assessed:thrombin-antithrombin III complex (TAT), prothrombin activation fragment F1 + 2, plasmin-alpha 2-antiplasmin complex (PAP) and the split product from cross-linked fibrin, D-dimer. The first sample was obtained before receiving any specific antineoplastic treatment. The patients were followed thereafter until treatment was terminated. There was no difference in activation markers between patients with SCLC and NSCLC. Comparing patients with limited disease to those with extensive disease, there were significant differences in TAT (median 3.0 (1.9-9.8) vs 5.3 (1.8-35.6) micrograms/l,P = 0.021) and D-dimer (569 (135-1948) vs 1288 (120-2221) micrograms/l, P = 0.014). According to the response to subsequent treatment, those who achieved complete or partial tumour remission had significantly lower baseline levels samples than non-responders (TAT 2.9 (1.9-4.0) vs 4.7 (1.8-35.6) micrograms/l,P = 0.0047;D-dimer 527 (135-1149) vs 1242 (120-2221) micrograms/l, P = 0.0013). Thus, the increase of TAT and D-dimer appears to be related to tumour spread. The results suggest that high levels of these markers might be a sign of unfavourable prognosis in patients with lung cancer.(ABSTRACT TRUNCATED AT 250 WORDS)

Adenocarcinoma↗