Nongenetic Determinants of Human Serum Esterases

A panel of 1151 unselected individuals was screened by starch gel electrophoresis for serum esterase variants. Two types of variants were observed which were shown by family studies not to be genetically determined. No consistent disease process was correlated with the occurrence of these variants. Suggestive evidence has been obtained to support the hypothesis that these variant proteins were produced by the action of exogenous neuraminidase on the individuals' normal C, esterases. A third type of variant enzyme was observed in 1 patient. This enzyme was shown to be a substantially larger molecule than the C, esterase and it is suggested that this protein may be a polymer of the C, esterase.     

The endocannabinoid system in the physiology and pathophysiology of the gastrointestinal tract

Numerous investigations have recently demonstrated the important roles of the endocannabinoid system in the gastrointestinal (GI) tract under physiological and pathophysiological conditions. In the GI tract, cannabinoid type 1 (CB1) receptors are present in neurons of the enteric nervous system and in sensory terminals of vagal and spinal neurons, while cannabinoid type 2 receptors are located in immune cells. Activation of CB1 receptors was shown to modulate several functions in the GI tract, including gastric secretion, gastric emptying and intestinal motility. Under pathophysiological conditions induced experimentally in rodents, the endocannabinoid system conveys protection to the GI tract (e.g. from inflammation and abnormally high gastric and enteric secretions). Such protective activities are largely in agreement with anecdotal reports from folk medicine on the use of Cannabis sativa extracts by subjects suffering from various GI disorders. Thus, the endocannabinoid system may serve as a potentially promising therapeutic target against different GI disorders, including frankly inflammatory bowel diseases (e.g. Crohns disease), functional bowel diseases (e.g. irritable bowel syndrome) and secretion- and motility-related disorders. As stimulation of this modulatory system by CB1 receptor agonists can lead to unwanted psychotropic side effects, an alternative and promising avenue for therapeutic applications resides in the treatment with CB1 receptor agonists that are unable to cross the blood–brain barrier, or with compounds that inhibit the degradation of endogenous ligands (endocannabinoids) of CB1 receptors, hence prolonging the activity of the endocannabinoid system.     

Prolongation of small bowel allograft survival with a sequential therapy consisting of a synthetic MHC class II peptide and temporarily low-dose cyclosporine A

It has been extensively documented the role of the indirect pathway of allorecognition in allograft rejection. However, recent data demonstrate that the manipulation of this pathway could be also sufficient to promote prolongation of allograft survival. In the present study we evaluated the effect of preoperative immunization with the WF-specific MHC class II peptides RT1.D2 and RT1.B2 in combination with low-dose CsA from days 0 to 7 (5 mg/kg/day) and from days 8 to 30 (1 mg/kg/day) after WF small bowel transplantation. Seven days before and on the day of transplantation, LEW recipients were immunized with the two WF MHC class II peptides RT1.B2 and RT1.D2. The CsA monotherapy induced an allograft survival of 49.3 +/- 6.1 days. MHC class II peptide immunization had a limited effect on allograft survival for RT1.D2 (47.1 +/- 3.8 days) and induced prolongation of allograft survival for RT1.B2 (73.6 +/- 34.6 days). This effect seems to be based on the absence or silence of RT1.B2-reactive T cells and rejection seems to be correlated with the presence of RT1.B2-specific T cells in the late phase. Therefore, the combination of RT1.B2 with low-dose CsA shifts the immunological response and protects small bowel allograft rejection.     

Pathological findings in coronary arteries associated with sudden death in Austria

Summary 50 witnessed sudden cardiac deaths in the age group between 20–50 years have been studied at autopsy. The most remarkable findings were a high percentage of stenosis and arterioisclerosis of the descending branch of the left coronary artery and a large amount of three vessel disease. It is clear that severe stenosis and sclerosis of the coronary arteries are not essentially related to sudden cardiac death, but a high number of vessels with moderate stenoses and sclerosis has been found.The severity of vessel disease has been evaluated by a coronary score, which takes the haemodynamic effects of the injured coronary arteries on the myocardium into account. We also noted that patients below 35 years of age who died of sudden cardiac death showed a very low coronary score.     

Correction of EOG Artifacts in Event-Related Potentials of the EEG: Aspects of Reliability and Validity

Correction of EOG artifacts using a regression approach is evaluated in terms of reliability and validity. Transmission rates are estimated for eight EEG channels in 67 subjects. The trimmed group means of these rates are shown to provide reliable measures. Eye artifact correction based on these group means is superior to the conventional rejection in terms of reducing correlation between EOG and EEG.     

Sequencing of the alpha-synuclein gene in a large series of cases of familial Parkinson's disease fails to reveal any further mutations. The European Consortium on Genetic Susceptibility in Parkinson's Disease (GSPD)

A mutation in exon 4 of the human alpha-synuclein gene was reported recently in four families with autosomal dominant Parkinson's disease (PD). In order to examine whether mutations in this exon or elsewhere in the gene are common in familial PD, all seven exons of the alpha- synuclein gene were amplified by PCR from index cases of 30 European and American Caucasian kindreds affected with autosomal dominant PD. Each product was sequenced directly and examined for mutations in the open reading frame. No mutations were found in any of the samples examined. We conclude that the A53T change described in the alpha- synuclein gene is a rare cause of PD or may even be a rare variant. Mutations in the regulatory or intronic regions of the gene were not excluded by this study.      

The spectrum of aldolase B (ALDOB) mutations and the prevalence of hereditary fructose intolerance in Central Europe

We investigated the molecular basis of hereditary fructose intolerance (HFI) in 80 patients from 72 families by means of a PCR-based mutation screening strategy, consisting of heteroduplex analysis, restriction enzyme digest, DNA single strand electrophoresis, and direct sequencing. For a subset of patients mutation screening with DHPLC was established which turned out to be as fast and as sensitive as the more conventional methods. Fifteen different mutations of the aldolase B (ALDOB) gene were identified in HFI patients. As in smaller previous studies, p.A150P (65%), p.A175D (11%) and p.N335K (8%) were the most common mutated alleles, followed by c.360_363delCAAA, p.R60X, p.Y204X, and c.865delC. Eight novel mutations were identified in eight families with HFI: a small indel mutation (c.1044_1049delTTCTGGinsACACT), two small deletions (c.345_372del28; c.841_842delAC), two splice site mutations (c.113-1G>A, c.799+2T>A), one nonsense mutation (c.612T>G (p.Y204X)), and two missense mutations (c.532T>C (p.C178R), c.851T>C (p.L284P)). By mutation screening for the three most common ALDOB mutations by DHPLC in 2,000 randomly selected newborns we detected 21 heterozygotes. Based on these data and after correction for less common and private ALDOB mutations, HFI prevalence in central Europe is estimated to be 1:26,100 (95% confidence interval 1: 12,600-79,000).     

5′-Cytosine DNA-methyltransferase mRNA levels in hereditary colon carcinoma

 DNA methylation plays an important part in the regulation of gene expression. Alterations in DNA methylation in tumours have been reported and have been used to generate hypotheses about mutagenesis and silencing of tumour suppressor genes. However, the underlying mechanism is still poorly understood, and conflicting data on the levels of overexpression of 5′-cytosine DNA methyltransferase in sporadic colon carcinoma have been published. We used a competitive RT-PCR assay for quantification of mRNA of 5′-cytosine DNA methyltransferase in colon biopsies obtained from patients with hereditary colon carcinoma syndromes and compared the results with those obtained in a control group. No significant difference was found between the flat mucosa of FAP patients and the mucosa of the control group. In FAP and HNPCC patients, the 5′-cytosine DNA methyltransferase mRNA levels of adenomas were significantly higher (P<0.05) than of flat mucosa in the same group, but both showed great variability from patient to patient. Our findings suggest that the mRNA levels of methyltransferase cannot be used as predictive marker for screening in families affected by hereditary colon carcinoma. Received: 20 July 1998 / Accepted: 21 September 1998     

Two-dimensional NMR spectroscopy of urinary glycosaminoglycans from patients with different mucopolysaccharidoses

Patients with different types of mucopolysaccharidoses (MPS) lack specific lysosomal enzymes, which leads to tissue accumulation and urinary excretion of glycosaminoglycans (GAGs). Since little is known about the molecular composition of the excreted GAG fragments, we used two-dimensional [1H,13C]-correlation nuclear magnetic resonance (NMR) spectroscopy for a detailed analysis of the urinary GAGs of patients with MPS types I, II, IIIA, IVA and VI. The method revealed that the molecular structures of the excreted GAGs, i.e. heparan sulfate (HS), dermatan sulfate (DS), chondroitin sulfate (CS), and keratan sulfate (KS) are clearly distinct for the different MPS types. The chain terminal residues that are the normal substrates for the defective enzymes constitute characteristic sets of signals for each MPS type. The GAG chains show variations in carbohydrate composition and sulfation patterns that can be related to the different MPS types and clinical features. For example, two patients with MPS IIIA (M. Sanfilippo) with signs of CNS degeneration but only mild somatic features excrete a highly sulfated variant of HS, resembling HS in porcine brain, whereas a patient with MPS I (M. Scheie) and two patients with MPS II (M. Hunter), who present primarily with coarse facial features, joint contractures and skeletal deformities excrete a different type of HS with lower sulfation. In another case study, a patient with MPS IVA (M. Morquio), who presented mainly with skeletal dysplasia, excreted not only excessive amounts of KS but also a highly sulfated CS variant, resembling CS in articular cartilage. The high-resolution NMR analysis of urinary GAGs presented here for the first time provides a solid basis for future studies with a larger number of patients to further explore pathogenesis and course of the MPS diseases.     

Morphomechanics of the humero-ulnar joint: II. Concave incongruity determines the distribution of load and subchondral mineralization

Background: A deeper joint socket (concave incongruity) is found at most angles of flexion of the humero-ulnar joint and maintained over a wide range of physiological loading. It is, however, unclear how far this incongruity affects the distribution of load and subchondral mineralization of this joint as compared with a congruous configuration. Methods: Two nonlinear, axisymmetrical finite element models with two cartilage layers were constructed, one congruous and one incongruous, with a joint space of realistic magnitude. The distribution of subchondral mineralization was determined by computed tomography osteoabsorptiometry in the same six specimens that were investigated in the first part of the study, and compared with the biomechanical data obtained there and the predictions of the models. Results: In the congruous case, the center of the socket is highly loaded, whereas the periphery does not experience mechanical stimulation. A central bone density maximum is predicted. With concave incongruity the position of the contact areas shifts from the joint margin towards the center as the load increases, and the peak stresses are considerably lower. A bicentric ventro-dorsal distribution pattern of subchondral mineralization is predicted, and this is actually found in the six specimens. Conclusions: Concave incongruity is shown to determine load transmission and subchondral mineralization of the humero-ulnar joint. It is suggested that this shape leads to a more even distribution of stress, provides intermittent stimulation of the cartilaginous tissue, and has beneficial effects on the metabolism, nutrition, and lubrication of the articular cartilage during cyclic loading. © 1995 Wiley-Liss, Inc.