The Na, K-ATPase alpha3-isoform specifically localizes in the Schmidt-Lanterman incisures of human nerve

INTRODUCTION

To our knowledge, there is little reference in literature with regards to alpha3-isoform of Na+,K+-ATPase in human peripheral nerves. The aim of this study was to determine the expression of the neuronal alpha3-isoform of Na+,K+-ATPase in human sural nerves from patients with a permanent medullary central nervous system injury.

MATERIALS AND METHODS

We studied the immunolocalization of alpha3-isoform of Na+,K+-ATPase using a polyclonal antibody against the amino sequence near the phosphorylation site of the alpha3-isoforms of Na+,K+-ATPase using immunohistochemistry and confocal laser scanning microscopy. An antibody specific for alpha2-isoform of Na+,K+-ATPase was used to label the Schwann cells.

RESULTS

Morphometric analysis of longitudinal section of human sural nerves showed that the alpha3-isoform of Na+,K+-ATPase was distributed along the length of axolemma. The myelin sheath of the Schwann cells showed clearly a distribution of alpha3- but not alpha2-isoforms of Na+,K+-ATPase at the level of Schmidt-Lanterman incisures.

CONCLUSION

The human sural nerve shows a specific localization of the Na+,K+-ATPase alpha3-isoform in the Schmidt-Lanterman incisures of Schwann cells in addition to its localization in axonal membranes.

Development and validation of a new Spanish instrument to measure health-related quality of life in patients with allergic rhinitis: the ESPRINT questionnaire

OBJECTIVES

To develop and validate an instrument to measure health-related quality of life (HRQOL) specific to patients with allergic rhinitis (AR) and primarily for use in Spanish and Spanish-speaking populations.

METHODS

An initial item pool was generated from literature review, focus groups with AR patients, and consultations with clinical experts. Item reduction was performed using clinimetric and psychometric approaches after administration of the item pool to 400 AR patients. The resulting instrument's internal consistency, test-retest (2-4 weeks) reliability, known groups and convergent validity, and sensitivity to change were tested in a longitudinal, observational, multicenter study in 210 AR patients who also completed the Rhinoconjunctivitis Quality of Life Questionnaire (RQLQ).

RESULTS

The new questionnaire took a mean (SD) of 7.1 (5.4) minutes to answer. Floor and ceiling effects were less than 15% on all dimensions. Cronbach's alpha values and intraclass correlation coefficient values for six of the sevendimensions and the overall score exceeded 0.70. Statistically significant differences (P < 0.01) were observed on all ESPRINT-28 dimensions and the overall score between patients with mild (mean overall score 1.97, SD 0.99), moderate (mean overall score 2.78, SD 0.88), and severe AR (mean overall score 3.89, SD 0.87). Patients with persistent AR had worse scores (P < 0.05) on all dimensions than patients with intermittent AR. Correlations between the ESPRINT-28 and the RQLQ were generally as expected. Effect sizes for score changes between the two study visits ranged from 0.96 to 1.76 for individual dimensions and the overall score.

CONCLUSIONS

This new, Spanish-developed instrument to measure HRQOL in AR patients has shown good reliability, validity, and sensitivity to change. It has also proved easy to use and administer.

Somatic hypermutation and mRNA expression levels of the BCL-6 gene in patients with hepatitis C virus-associated lymphoproliferative diseases

Chronic hepatitis C virus (HCV) infection leads to mixed cryoglobulinaemia (MC) and B-cell non-Hodgkin lymphoma (B-NHL). Aberrant somatic hypermutation and deregulation of the oncogene BCL-6 is associated with lymphomagenesis. Recently, HCV was shown to induce BCL-6 mutations in vitro. The BCL-6 gene (area B) was cloned and sequenced from peripheral blood mononuclear cells (PBMC) of 21 chronically HCV-infected patients with or without MC and B-NHL, and six healthy controls. Mutational frequencies, genetic complexity and diversity were calculated. BCL-6 mRNA from PBMC was quantified by real-time polymerase chain reaction, and additional sustained virologic responders to antiviral therapy and HBV patients served as controls. The overall/recurrent mutational frequencies tended to be lower in MC and B-NHL patients when compared with controls (P = 0.15 and 0.06, respectively). Genetic complexity was significantly lower in MC and B-NHL patients (P = 0.025). BCL-6 mRNA concentration was decreased in all HCV patients when compared with healthy controls, sustained virologic responder and HBV patients (P = 0.005). Although HCV can induce BCL-6 mutations in vitro, lower mutational frequencies and decreased BCL-6 mRNA expression in vivo suggest no major role of aberrant somatic hypermutation in HCV-associated MC and B-NHL.

A new strategy based on recombinant viruses as a tool for assessing drug susceptibility of human immunodeficiency virus type 1

The emergence of drug-resistant variants during antiretroviral therapy is a serious obstacle to sustained suppression of the human immunodeficiency virus type 1 (HIV-1). For that reason, resistance assays are essential to guide clinicians in the selection of optimal treatment regimens. Genotypic assays are less expensive and results are available faster than phenotypic assays. However, in heavily experienced patients with multiple treatment failures interpretation of complex mutation patterns remains difficult, and in these cases phenotypic assays are recommended. This report describes a novel recombinant virus assay where protease (PR) and reverse transcriptase (RT) sequences derived from the plasma isolated from patients are introduced into the back-bone of an HIV molecular clone that expresses Renilla luciferase protein in the place of nef gene. All drug resistance profiles analyzed correlate with previously reported data and showed high reproducibility. This assay, in addition to a fast (completed in 10 days), precise, reproducible and automated method, presents several advantages as compared to other phenotypic assays. The system described below allows the generation of recombinant viruses with multiples cycles of replication carrying a reporter gene in their genomes. These features increase the sensitivity of the test, an important aspect to be considered in the evaluation of less fit viral isolates. In conclusion, the assay permits the quantitation of the level of resistance of clinical HIV-1 isolates to PR and RT inhibitors.

An inversion inv(4)(p12-p15.3) in autistic siblings implicates the 4p GABA receptor gene cluster

INTRODUCTION

We describe the case of two brothers diagnosed with autism who both carry a paracentic inversion of the short arm of chromosome 4 (46,XY, inv(4)(p12-p15.3)). We have determined that this inversion is inherited from an apparently unaffected mother and unaffected maternal grandfather. Methods/

RESULTS

Using fluorescence in situ hybridisation analysis and Southern blot hybridisation we identified the breakpoints. The proximal breakpoint (4p12) maps to a region containing a cluster of gamma-aminobutyric acid A (GABA(A)) receptor genes, and directly interrupts the GABRG1 gene, the distal-most gene of the cluster. We also identified an insertion/deletion polymorphism for a approximately 2 kb LINE1 (L1) element that occurs within intron 7 of GABRG1. Our genotype analysis amongst autism families indicated that the L1 deletion allele did not show increased transmission to affected individuals. No linkage disequilibrium was evident between the L1 and single nucleotide polymorphisms in adjacent GABA(A) receptor genes on 4p, where a recent study has identified significant association with autism.

DISCUSSION

Despite this, the identification of an inversion breakpoint disrupting GABRG1 provides solid support for the genetic involvement of the short arm of chromosome 4 in the genetic aetiology of autism, and for the hypothesis of disrupted GABA neurotransmission in autism.

Discrete time piecewise affine models of genetic regulatory networks

We introduce simple models of genetic regulatory networks and we proceed to the mathematical analysis of their dynamics. The models are discrete time dynamical systems generated by piecewise affine contracting mappings whose variables represent gene expression levels. These models reduce to boolean networks in one limiting case of a parameter, and their asymptotic dynamics approaches that of a differential equation in another limiting case of this parameter. For intermediate values, the model present an original phenomenology which is argued to be due to delay effects. This phenomenology is not limited to piecewise affine model but extends to smooth nonlinear discrete time models of regulatory networks. In a first step, our analysis concerns general properties of networks on arbitrary graphs (characterisation of the attractor, symbolic dynamics, Lyapunov stability, structural stability, symmetries, etc). In a second step, focus is made on simple circuits for which the attractor and its changes with parameters are described. In the negative circuit of 2 genes, a thorough study is presented which concern stable (quasi-)periodic oscillations governed by rotations on the unit circle - with a rotation number depending continuously and monotonically on threshold parameters. These regular oscillations exist in negative circuits with arbitrary number of genes where they are most likely to be observed in genetic systems with non-negligible delay effects.

Étude ultrastructurale des membranes épirétiniennes idiopathiques colorées au bleu trypan

INTRODUCTION

Idiopathic epiretinal membrane results from detachment of the posterior hyaloid and is believed to be related to naturally occurring defects in the internal limiting membrane (ILM) of the retina. Vitrectomy and peeling are the treatment of choice. Trypan blue 0.15% (TB) stains epiretinal membrane and internal limiting membrane. It allows selective and complete removal, facilitating surgery, with less retinal damage. An ultrastructural study was conducted showing ultrastructural features of idiopathic epiretinal membranes (ERM) and those of the internal limiting membrane and its connections with the retinal side.

MATERIAL AND METHODS

After pars plana vitrectomy and induction of posterior vitreous detachment, 0.2 ml TB 0.15% was injected over the ERM in an air-filled eye. The stained tissue was peeled with intraocular forceps. Specimens were at once collected in 4% glutaraldehyde for a transmission electron microscopy study.

RESULTS

TB may allow complete and easier ERM and ILM peeling. The staining does not present toxic effects. The major cellular contingent is represented by glial cells, participating actively in neocollagen synthesis. Their presence supports the hypothesis of a migratory movement of retinal cells toward the vitreoretinal side.

CONCLUSION

The presence of an intact internal limiting membrane, the absence of optical fibers belonging to the under retina, and the absence of any sign of apoptosis make TB a useful staining agent for ERM and ILM peeling.

Intranuclear arrangement of human chromosome 12 is reflected in metaphase chromosomes as non-random bending

We have found a high correlation of non-random bending of human metaphase chromosome 12 with the intranuclear arrangement deduced by Nogami et al. (Chromosoma 108 (2000) 514), providing further evidence of the relation of non-random bending and the interphase organization of the nucleus.

EVALUATION OF FUNCTIONAL IMPROVEMENT IN OLDER PATIENTS WITH COGNITIVE IMPAIRMENT, DEPRESSION AND/OR DELIRIUM ADMITTED TO A GERIATRIC CONVALESCENCE HOSPITALIZATION UNIT

Cognitive impairment, depression and delirium are problems of high prevalence in older patients. The geriatric convalescence unit (GCU) is a hospitalization facility offering an interdisciplinary geriatric intervention program that may be more appropriate for these patients. This study intended to analyze the functional improvement (FI) in older patients with cognitive impairment, depression and/or delirium admitted to a GCU. A group of 107 patients received specific nurse care, habitually performed in GCU and they also were included in a rehabilitation program. Cognitive impairment, depression and delirium were diagnosed according to standardized protocols. The analyzed variables were: age, functional status (Barthel index) before admission (BBA), at admission (BA) and at discharge(BD), diagnostic categories, cognitive function (mini mental state examination: MMSE) and post-discharge destination. The corrected Heinemann index (CHI) was used to evaluate FI obtained during GCU-stay, where CHI = 100 x (BD-BA)/(BBA-BA), and the efficiency index(El) was used to analyze the relationship between FI and the length of stay in the GCU,where El = (BD-BA)/(days in GCU). According to CHI, patients were divided in three groups. Group I: CHI = 0 or negative (patients who lost functional capacity during hospitalization,those who died or were transferred to hospital owing to acute deterioration. Group II: CHI < 35 % (high FI). Mean age was 77.6 +/- 9.1 years, the diagnostic categories were: fractures/orthopedics 49 (45.7 %), neurological 27(25.2 %), pulmonary/cardiologic 6 (5.6 %) and other cases 25 (23.3 %). Mean MMSE and BA scores were 16.9 +/- 9.4 and 29.6 +/- 18.9, respectively. Post-discharge destinations were:63 patients (58.8 %) returned home, 28 (26.1 %) were definitively institutionalized, 11 (10.2%) died and finally 5 (4.6 %) were transferred to acute care hospital. In-Group I, there were 35 patients (32.7 %) with a mean value of the El = 0.12 +/-1.1; in Group II, 13 (12.1 %) and 0.26 +/- 0.38; in Group III, 59 (55.1 %) and 0.94 +/- 0.97, respectively. In spite of the presence of cognitive impairment, depression and/or delirium, a high proportion of patients (67.2 %)obtained a significant improvement in their functional capacity.35 % (moderate FI). Group III: CHI >/=

[Botulinum toxin and traumatic brain injury]

Botulinum toxin is a successful focal spasticity therapy. The aim of this article is to study the data of the literature concerning its utilisation in traumatic brain injured patients, whom motor and tonus disturbances are polymorphic, in their clinical presentation as well as in their evolution. Although there are few studies concerning its utilisation in such patients, none of them being controlled, its use seems interesting in focal spasticity treatment. It can contribute to improve functional abilities and comfort for these patients.

Predictive, pre-natal and diagnostic genetic testing for Huntington's disease: the experience in Canada from 1987 to 2000

Predictive and pre-natal testing for Huntington's Disease (HD) has been available since 1987. Initially this was offered by linkage analysis, which was surpassed by the advent of the direct mutation test for HD in 1993. Direct mutation analysis provided an accurate test that not only enhanced predictive and pre-natal testing, but also permitted the diagnostic testing of symptomatic individuals. The objective of this study was to investigate the uptake, utilization, and outcome of predictive, pre-natal and diagnostic testing in Canada from 1987 to April 1, 2000. A retrospective design was used; all Canadian medical genetics centres and their affiliated laboratories offering genetic testing for HD were invited to participate. A total of 15 of 22 centres (68.2%), currently offering or ever having offered genetic testing for HD, responded, providing data on test results, demographics, and clinical history. A total of 1061 predictive tests, 15 pre-natal tests, and 626 diagnostic tests were performed. The uptake for predictive testing was approximately 18% of the estimated at-risk Canadian population, ranging from 12.5% in the Maritimes to 20.7% in British Columbia. There appears to have been a decline in the rate of testing in recent years. Of the predictive tests, 45.0% of individuals were found to have an increased risk, and a preponderance of females (60.2%) sought testing. A greater proportion of those at < or = 25% risk sought predictive testing once direct CAG mutation analysis had become available (10.9% after mutation analysis vs 4.7% before mutation analysis, p = 0.0077). Very few pre-natal tests were requested. Of the 15 pre-natal tests, 12 had an increased risk, resulting in termination of pregnancy in all but one. Diagnostic testing identified 68.5% of individuals to be positive by mutation analysis, while 31.5% of those with HD-like symptoms were not found to have the HD mutation. The positive diagnostic tests included 24.5% of individuals with no known prior family history of HD.

Receptor-independent role of the urokinase-type plasminogen activator during arteriogenesis

To define the role of the plasminogen activators (PAs) urokinase PA (uPA) and tissue PA (tPA) as well as the uPA receptor (uPAR) in arteriogenesis, we investigated their impact in a rabbit and mouse model of adaptive collateral artery growth. Collateral artery growth was induced by occlusion of the femoral artery in rabbit and wild-type (WT) mice and in mice with targeted inactivation of uPA (uPA-/-), tPA (tPA-/-), or uPAR (uPAR-/-). Northern blot results revealed a significant up-regulation of uPA but not uPAR or tPA in the early phase of arteriogenesis in rabbit and WT mice. This up-regulation on RNA level was followed by an increased protein level and enzymatic activity. Impaired perfusion recovery upon femoral artery ligation was observed by laser Doppler analysis in vivo in uPA-deficient mice but not in uPAR or tPA deficiency compared with WT mice. Immunohistochemical studies revealed an association of leukocyte infiltration with arteriogenesis in WT mice that was strongly reduced in uPA-/- but not in uPAR- or tPA-deficient mice. We conclude that arteriogenesis is promoted by an uPA-mediated infiltration of leukocytes that is not dependent on uPAR.

Changes in Glial Fibrillary Acidic Protein Immunoreactivity in Response to Experimental Hepatic Encephalopathy in the Rat Hippocampus

The response of astroglial cells in the hippocampus to long-term portacaval anastomosis (PCA), an experimental model of hepatic encephalopathy, was studied in adult male rats and compared with controls. Six months after PCA, the rat hippocampi were processed for glial fibrillary acidic protein (GFAP). GFAP-immunopositive astroglial profiles were observed in all hippocampal layers in PCA rats, but GFAP distribution differed in PCA rats and controls. In PCA rats, cell bodies and cell processes immunostained with GFAP were observed mainly in the CA1-CA3 layers in relation to pyramidal neurons, whereas the number and length of the astroglial processes decreased in the rest of the hippocampal regions. In addition, decreased GFAP immunoreactivity in the perivascular processes was observed in PCA rats compared with controls. These results show that long-term PCA elicited different responses in GFAP expression in different hippocampal regions, which might suggest a regional variation in glial sensitivity.

Cadmium-containing granules in kidney tissue of the Atlantic white-sided dolphin (Lagenorhyncus acutus) off the Faroe Islands

Top predators from the northern sub-polar and polar areas exhibit high cadmium concentrations in their tissues. In the aim to reveal possible adverse effects, samples of five Atlantic white-sided dolphins Lagenorhyncus acutus have been collected on the occasion of the drive fishery in the Faroe Islands, for ultrastructural investigations and energy dispersive X-ray microanalyses. Cadmium concentrations were less than the limit of detection in both immature individuals and ranged from 22.7 to 31.1 microg x g(-1) wet weight in the mature individuals. Two individuals with the highest cadmium concentrations exhibited electron dense mineral concretions in the basal membranes of the proximal tubules. They are spherocrystals made up of numerous strata mineral deposit of calcium and phosphorus together with cadmium. Cadmium has been detected with a molar ratio of Ca:Cd of 10:1 in the middle of these concretions. To our knowledge, this is the first report of such granules in a wild vertebrate. The role of these granules in the detoxification of the metal and the possible pathological effects are considered.

Role of ischemia and of hypoxia-inducible genes in arteriogenesis after femoral artery occlusion in the rabbit

Vascular endothelial growth factor (VEGF) is known to play an important role in angiogenesis. Its place in collateral artery growth (arteriogenesis), however, is still debated. In the present study, we analyzed the expression of VEGF and its receptors (Flk-1 and Flt-1) in a rabbit model of collateral artery growth after femoral artery occlusion. Hypoxia presents the most important stimulus for VEGF expression. We therefore also investigated the expression level of distinct hypoxia-inducible genes (HIF-1alpha, LDH A) and determined metabolic intermediates indicative for ischemia (ATP, creatine phosphate, and their catabolites). We found that arteriogenesis was not associated with an increased expression of VEGF or the mentioned hypoxia-inducible genes. Furthermore, the high-energy phosphates and their catabolites were entirely within normal limits. Despite the absence of an increased expression of VEGF and its receptors, collateral vessels increased their diameter by a factor of 10. The speed of collateral development could be increased by infusion of the chemoattractant monocyte chemotactic protein-1 but not by infusion of a 30 times higher concentration of VEGF. From these data, we conclude that under nonischemic conditions, arteriogenesis is neither associated with nor inducible by increased levels of VEGF and that VEGF is not a natural agent to induce arteriogenesis in vivo.

Non-syndromic progressive hearing loss DFNA38 is caused by heterozygous missense mutation in the Wolfram syndrome gene WFS1

Dominantly inherited progressive hearing loss DFNA38 is caused by heterozygosity for a novel mutation in WFS1, the gene for recessively inherited Wolfram syndrome. Wolfram syndrome is defined by juvenile diabetes mellitus and optic atrophy and may include progressive hearing loss and other neurological symptoms. Heterozygotes for other Wolfram syndrome mutations generally have normal hearing. Dominant deafness defined by DFNA38 is more severe than deafness of Wolfram syndrome patients and lacks any syndromic features. In a six-generation kindred from Newfoundland, Canada, WFS1 Ala716Thr (2146 G-->A) was shared by all deaf members of the family and was specific to deaf individuals. The causal relationship between this missense mutation and deafness was supported by two observations based on haplotype and mutation analysis of the kindred. First, a relative homozygous for the mutation was diagnosed at age 3 years with insulin-dependent diabetes mellitus, the central feature of Wolfram syndrome. Second, two relatives with normal hearing had an identical haplotype to that defining DFNA38, with the exception of the base pair at position 2146. Other rare variants of WFS1 co-inherited with deafness in the family could be excluded as disease-causing mutations on the basis of this hearing-associated haplotype. The possibility that 'mild' mutations in WFS1 might be a cause of non-syndromic deafness in the general population should be explored.

Relief of sleep apnea after intravascular stenting for superior vena cava syndrome

A rarely reported association of sleep apnea and superior vena cava stenosis from mediastinal fibrosis is described. A case is presented where substantial improvement in the sleep parameters and the symptoms of sleep apnea occurred subsequent to superior vena cava thrombolysis and stent angioplasty.

Ultrastructural study of rat hippocampus after chronic administration of aluminum L-glutamate: an acceleration of the aging process

An ultrastructural study of rat hippocampus was performed on young (group 1) and old (group 4) rats receiving daily subcutaneous injections of aluminum L-glutamate and on old untreated rats (group 5). Young controls were treated with sodium L-glutamate (group 2) and physiological saline (group 3). Group 1 showed vacuolated astrocytes with numerous lipofuscin deposits, mitochondrial swelling, a thinning of the myelin sheath, and many multivesicular bodies invading the cytoplasm. Cellular structure did not appear to be affected in groups 2 and 3. Group 4 showed swollen mitochondria, a demyelination process in axonal regions, sizable perivascular oedema with vessel retraction and gliofilament bundles. In this group, lipofuscin deposits in astrocytes were associated with multivesicular bodies that thinned the myelin sheath to the breaking point; however, no excitotoxic glutamate-induced effects were observed. In group 5, extreme cytoplasmic vacuolation was observed, with massive mitochondrial swelling, considerable thinning of the myelin sheath (at times to the breaking point), sizable vacuolar degeneration and gliofilament bundles. These results indicate that ultrastructural alterations in the hippocampus, such as cell vacuolization, massive mitochondrial swelling and the demyelination process, occur with aging and independently of aluminum intoxication. Similar alterations were observed in aluminum L-glutamate-intoxicated young rats, but not in controls. These results are consistent with aluminum-induced acceleration of the aging process.