Muscle pathology in 31 patients with calpain 3 gene mutations

Background and purposeAt present, more than 20 different forms of limb-girdle muscular dystrophies (LGMDs) are known (at least 7 autosomal dominant and 14 autosomal recessive). Although these different forms show some typical phenotypic characteristics, the existing clinical overlap makes their differential diagnosis difficult. Limb-girdle muscular dystrophy type 2 (LGMD2A) is the most prevalent LGMD in many European as well as Brazilian communities and is caused by mutations in the gene CAPN3. Laboratory testing, such as calpain immunohistochemistry and Western-blot analysis, is not totally reliable, since up to 20% of molecularly confirmed LGMD2A show normal content of calpain 3 and a third of LGMD2A biopsies have normal calpain 3 proteolytic activity in the muscle. Thus, genetic testing is considered as the only reliable diagnostic criterion in LGMD2A.Material and methodsIn an attempt to find a correlation between genotype and muscle pathology in limb-girdle muscular dystrophy 2A we performed histopathological investigation of a group of 31 patients subdivided according to the type of pathologic CAPN3 gene mutation.ResultsIn all biopsies typical features of muscular dystrophy such as fiber necrosis and regeneration, variation in fiber size and fibrosis were noted. Lobulated fibers were often encountered in the muscle biopsies of LGMD2A patients. Such fibers were more frequent in patients with 550delA mutation.ConclusionsThese findings may be helpful in establishing diagnostic strategies in LGMD.     

Antigenic determinants of influenza virus hemagglutinin. XI. Conformational changes detected by monoclonal antibodies

At pH 5 influenza virus hemagglutinin undergoes an irreversible conformational change (J.J. Skehel, P. M. Bayley, E. B. Brown, S. R. Martin, M. D. Waterfield, J. M. White, I. A. Wilson, and D. C. Wiley (1982). Proc. Natl. Acad. Sci. USA 79, 968-972) which parallels the appearance of fusion activity of this molecule. This paper describes experiments which explore the conformational change using a panel of monoclonal antibodies which define four of the major antigenic sites of this protein. The results indicate that three of the major antigenic sites of hemagglutinin undergo changes when exposed to acid pH. These changes have little effect on the binding avidity of influenza virus to glycophorin, the major receptor present on the red blood cell surface. These findings have been used to postulate a mechanism where the molecule flexes around a central region resulting in rearrangement in space of its component domains on exposure to low pH.     

Antiphospholipid antibodies in high-risk pregnancy

Recently the connection of antiphospholipid antibodies (aPLs) presence with pregnancy loss and complications in pregnancy has been observed APLs related obstetric complications include: miscarriages after 10 weeks, IUGR, intrauterine foetal death, preeclampsia and severe preeclampsia. Our objective was to determine the aPLs prevalence in patients with recurrent pregnancy loss and/or complicated pregnancy. We examined 154 pregnant women aged 19-42 (average of 29.1) with recurrent pregnancy loss, current pregnancy complicated by preeclampsia and severe preeclampsia and/or IUGR, thrombotic episodes, thrombocytopenia or autoimmune disease. In all the patients anticardiolipin antibodies (aCL) were determined at least twice using ELISA and their coagulation system was tested including lupus anticoagulant (LA) test. In justified cases immunological examinations detecting connective tissue systemic diseases were conducted. Increased aCL titre was detected in 54 (34.4%) women. Statistically significant risk of increased aCL titre was observed in patients with autoimmunological diseases (RR = 4.3). Increased, but Statistically insignificant, risk of high aCL titre was observed in patients with venous thrombosis (RR = 2.45) as well as in patients with thrombocytopenia (RR = 2.45). LA prevailed significantly more often in patients with venous thrombosis episodes (RR = 6.33) and with autoimmunological diseases (RR = 17.4). Preterm deliveries were significantly more frequent in pregnant women with increased aCL titre and/or LA. Moreover, in this group foetal death and preterm stillbirth more often occurred. The above mentioned risks increased when aCL and LA coexisted. No relation between increased aPLs and miscarriage frequency was observed. CONCLUSIONS: 1) Increased aPLs titre prevail in multiparas with bad obstetrical anamnesis and with pathological course in present pregnancy, 2) increased aPLs titre prevail in patients with autoimmunological diseases, 3) increased aPLs titre are connected with pregnancy pathology manifested by frequent preterm deliveries and intrauterine foetal deaths.     

HLA-inferred extended haplotype disparity level is more relevant than the level of HLA mismatch alone for the patients survival and GvHD in T cell-replate hematopoietic stem cell transplantation from unrelated donor

Serious risks in unrelated hematopoietic stem cell transplantation (HSCT) including graft versus host disease (GvHD) and mortality are associated with HLA disparity between donor and recipient. The increased risks might be dependent on disparity in not-routinely-tested multiple polymorphisms in genetically dense MHC region, being organized in combinations of two extended MHC haplotypes (Ehp). We assessed the clinical role of donor-recipient Ehp disparity levels in N?=?889 patients by the population-based detection of HLA allele phase mismatch. We found increased GvHD incidences and mortality rates with increasing Ehp mismatch level even with the same HLA mismatch level. In multivariate analysis HLA mismatch levels were excluded from models and Ehp disparity level remained independent prognostic factor for high grade acute GvHD (p?=?0.000037, HR?=?10.68, 95%CI 5.50–32.5) and extended chronic GvHD (p?<?0.000001, HR?=?15.51, CI95% 5.36–44.8). In group with single HLA mismatch, patients with double Ehp disparity had worse 5-year overall survival (45% vs. 56%, p?=?0.00065, HR?=?4.05, CI95% 1.69–9.71) and non-relapse mortality (40% vs. 31%, p?=?0.00037, HR?=?5.63, CI95% 2.04–15.5) than patients with single Ehp disparity. We conclude that Ehp-linked factors contribute to the high morbidity and mortality in recipients given HLA-mismatched unrelated transplant and Ehp matching should be considered in clinical HSCT.     

Cerebrospinal fluid and blood propofol concentration during total intravenous anaesthesia for neurosurgery

Background. The aim of this paper is to compare the propofolconcentration in blood and cerebrospinal fluid (CSF) in patientsscheduled for different neurosurgical procedures and anaesthetizedusing propofol as part of a total intravenous anaesthesia technique. Methods. Thirty-nine patients (ASA I–III) scheduled forelective intracranial procedures, were studied. Propofol wasinfused initially at 12 mg kg^–1 h^–1 and thenreduced in steps to 9 and 6 mg kg^–1 h^–1. Duringanaesthesia, bolus doses of fentanyl and cis-atracurium wereadministered as necessary. After tracheal intubation the lungswere ventilated to achieve normocapnia with an oxygen-air mixture(FI_O2=0.33). Arterial blood and CSF samples for propofol examinationwere obtained simultaneously directly after intracranial drainageinsertion and measured using high-performance liquid chromatography.The patients were divided into two groups depending on the typeof neurosurgery. The Aneurysm group consisted of 13 patientswho were surgically treated for ruptured intracranial aneurysm.The Tumour group was composed of 26 patients who were undergoingelective posterior fossa extra-axial tumour removal. Results. Blood propofol concentrations in both groups did notdiffer significantly (P>0.05). The propofol concentrationin CSF was 86.62 (SD 37.99) ng ml^–1 in the Aneurysm groupand 50.81 (26.10) ng ml^–1 in the Tumour group (P<0.005). Conclusions. Intracranial pathology may influence CSF propofolconcentration. However, the observed discrepancies may alsoresult from quantitative differences in CSF composition andfrom restricted diffusion of the drug in the CSF. Br J Anaesth 2003; 90: 84–6     

Hyperinsulinism: molecular aetiology of focal disease

Persistent hypoglycaemia in infancy is most commonly caused by hyperinsulinism. A case is reported of the somatic loss of the maternal 11p in an insulin secreting focal adenoma in association with a germline SUR-1 mutation on the paternal allele in a baby boy with hyperinsulinism diagnosed at 49 days old. A reduction to homozygosity of an SUR-1 mutation is proposed as a critical part of the cause of focal hyperinsulinism.     

Progeria caused by a rare LMNA mutation p.S143F associated with mild myopathy and atrial fibrillation.

We present a 6-year-old girl with premature aging associated with mild myopathy, displaying muscle weakness, joint contractures and hyporeflexia. Genetic analysis revealed rare heterozygous point mutation in lamin A/C gene, g.428C>T. Cardiological evaluation showed atrial fibrillation, but we did not find signs of coronary heart disease, which is life-threatening cardiovascular complication in progeria. Electron microscopy of the muscle revealed abnormalities in nuclear architecture, i.e. blebbing, thick lamina and peripheral distribution of heterochromatin. As some diagnostic criteria characteristic for classic progeria are not fulfilled, this case could be regarded as atypical progeria associated with myopathy and atrial fibrillation. To our knowledge, this is the second case of such association described in the literature.