POS0914 LATE SKIN FIBROSIS IN SYSTEMIC SCLEROSIS: A STUDY FROM THE EUSTAR COHORT

Background

Skin fibrosis is a cardinal feature of systemic sclerosis (SSc) and associated with significant disability. The early trajectory of skin fibrosis provides insights into the course of the disease including mortality; however, little is known about late skin fibrosis in SSc.

Objectives

The aims of our study were to ascertain the prevalence and characteristics of late skin fibrosis in SSc.

Methods

We developed and tested three conceptual scenarios of late (>5 years after 1st non-RP sign or symptom) skin fibrosis (Figure 1):

Figure 1.

Conceptual models/scenarios of late skin fibrosis in SSc. A: worsening and then improvement (>3 mRSS) during the first 5 years, and then worsened again after 5 years. B: worsening for the first time after 5 years. C: worsening in the first 5 years and stayed high after 5 years (i.e., failure to improve).

A. Worsening and then improvement (>3 mRSS) during the first 5 years, and then worsened again after 5 years.

B. Worsening for the first time after 5 years.

C. Worsening in the first 5 years and stayed high after 5 years (i.e., failure to improve).

We defined skin worsening as modified Rodnan skin score (mRSS) ≥ 5 units or ≥ 25%. Using strict inclusion criteria including complete mRSS, we identified 1,043 (out of 19,115) patients within the EUSTAR database for our analysis. We further restricted analysis within 887 (out of 1,043) patients who had limited (lcSSc) or diffuse cutaneous SSc (dcSSc) at baseline.

Results

One-fifth of patients among the whole cohort (n=208/1043, 19.9%) including in patients with lcSSc or dcSSc at baseline (n=193/887, 21.8%) developed late skin fibrosis. This was largely due to new skin worsening or failure to improve. Patients with lower baseline mRSS and lcSSc were more likely to develop late skin fibrosis. Anti-Scl-70 antibodies (Table 1) were associated with progression from baseline lcSSc to dcSSc, and anticentromere antibodies were protective.

Table 1.

Impact of autoantibody status on progression from baseline limited to diffuse cutaneous SSc (dcSSc).

Skin worsening after 5 years (Scenario B) (n=70)Skin worsening within 5 years and failed to improve after 5-year window (Scenario C) (n=61)Progressed to dcSSc (n=23)Not progressed to dcSSc(n=47)P-valueProgressed to dcSSc (n=37)Not progressed to dcSSc(n=24)P-valueAnticentromere+ve2/22 (9.1%)19/42 (45.2%)0.00346/34 (17.6%)14/21 (66.7%)0.0002-ve20/22 (90.9%)23/42 (54.8%)28/34 (82.4%)7/21 (33.3%)Anti-Scl-70+ve15/23 (65.2%)14/44 (31.8%)0.008822/36 (61.1%)8/23 (34.8%)0.0485-ve8/23 (34.8%)30/44 (68.2%)14/36 (38.9%)15/23 (65.2%)Anti-RNA-Polymerase-III+ve0/12 (0.0%)1/22 (4.5%)1.00000/6 (0.0%)0/14 (0.0%)---ve12/12 (100%)21/22 (95.5%)6/6 (100%)14/14 (100%)

Conclusion

Late skin fibrosis affects approximately 20% of SSc patients >5 years after onset of disease. We have identified different patterns relevant to clinical practice and trial design. Late skin fibrosis is usually due to new worsening or failure of skin to improve. Progression from baseline limited to diffuse cutaneous SSc was associated with anti-Scl-70 antibodies, and anticentromere antibodies were protective. Late skin fibrosis is a neglected manifestation of SSc and warrants further investigation including to determine clinical outcomes and optimal therapeutic strategy.

Acknowledgements

On behalf of EUSTAR collaborators.

Disclosure of Interests

Michael Hughes Speakers bureau: Speaking fees from Actelion pharmaceuticals, Eli Lilly, and Pfizer, outside of the submitted work, Suiyuan Huang: None declared, Juan Jose Alegre Sancho Speakers bureau: Speaking and/or investigational fees from Actelion pharmaceuticals, Eli Lilly, Pfizer, Boehringer Ingelheim, Roche, and GSK, outside of the submitted work, Grant/research support from: Speaking and/or investigational fees from Actelion pharmaceuticals, Eli Lilly, Pfizer, Boehringer Ingelheim, Roche, and GSK, outside of the submitted work, Patricia Carreira: None declared, Merete Engelhart: None declared, Eric Hachulla Speakers bureau: Received consulting fees/meeting fees from Johnson & Johnson, Boehringer Ingelheim, Bayer, GSK, Roche-Chugai, Sanofi-Genzyme; speaking fees from Johnson & Johnson, GSK, Roche-Chugai; and research funding from CSL Behring, GSK, Roche-Chugai and Johnson & Johnson., Consultant of: Received consulting fees/meeting fees from Johnson & Johnson, Boehringer Ingelheim, Bayer, GSK, Roche-Chugai, Sanofi-Genzyme; speaking fees from Johnson & Johnson, GSK, Roche-Chugai; and research funding from CSL Behring, GSK, Roche-Chugai and Johnson & Johnson., Jörg Henes Speakers bureau: Lectures for CHUGAI, Boehringer-Ingelheim, Eduardo Kerzberg: None declared, Maria Rosa Pozzi: None declared, Gabriela Riemekasten: None declared, Vanessa Smith: None declared, Gabriella Szucs: None declared, Marie Vanthuyne: None declared, Elisabetta Zanatta: None declared, Oliver Distler: None declared, Armando Gabrielli: None declared, Anna-Maria Hoffmann-Vold: None declared, Viginia Steen: None declared, Dinesh Khanna Shareholder of: DK has stock options in Eicos Sciences, Inc., Consultant of: Consultant for Acceleron, Amgen, Boehringer Ingelheim, CSL Behring, Chemomab, Genentech/Roche, Horizon, Mitsubishi Tanabe Pharma, Prometheus, Talaris., Grant/research support from: Has received grants from Bayer, BMS, Horizon and Pfizer (to University of Michigan).

Two in one: Neuregulin 1 improves cardiac diastolic and kindney funtcion in chronic kidney disease in rats

Introduction

The prevalence of chronic renal disease (CKD) is continuously increasing in developed countries. Uremic cardiomyopathy characterized by left ventricular hypertrophy (LVH) and diastolic dysfunction (DD) is a common cardiovascular complication of CKD. Cardiac microvascular low-grade inflammation and altered expression of endothelium derived Neuregulin-1 (NRG-1) are contributed to left ventricular DD. Our aim was to charachterize the effects of CKD on the expression of NRG-1 and 2) NRG-1 treatment on myocardial hypertrophy, diastolic dysfunction and renal function in the rat model of CKD.

Methods

Male Wistar rats were used and randomized into 3 groups: 1) Sham-operated,2) CKD induced by 5/6 nephrectomy (CKD) and 3) NRG-1-treated CKD group (CKD+NRG-1). In this group, 2 weeks after the CKD induction, the rats were treated with recombinant human NRG-1 (rhNRG-1) at the dose of 10 μg/kg/d for consecutive 10 days with tail vein injection of NRG-1. Serum and urea creatinine levels were measured to verify the development of CKD and transthoracic echocardiography was performed to monitor cardiac morphology and function. Furthermore, total RNA was isolated and RT-qPCR was performed to evaluate the expression levels of inflammatory chemokine and cytokines (TNF-α, TGF-β). In addition, NRG-1 protein levels were assessed in both kidney and heart tissue by ELISA. To clarify the underling anti-fibrotic mechanism, human ventricular cardiac fibroblasts (HCF) were cultured and treated with the TGF-β (20 ng/ml), and TGF-β + hrNRG-1 for 24 h, respectively. Confocal microscopy was used to detect α-smooth muscle actin (α-SMA) expression, marker for fibroblast to myofibroblast transtion.

Results

10 weeks after the 5/6 nephrectomy, serum carbamide and creatinine levels were significantly increased and creatinine clearence was significantly decreased as compared to sham-operated animals proving the development of chronic kidney disease (CKD). This was accompanied by a significant decrease in NRG-1 protein expression levels in both cardiac and kidney tissue. Of note, NRG-1 treatment markedly reduced these changes, suggesting its renoprotective effects in CKD. In addition, In CKD animals, the significantly increased anterior, posterior and septal wall thicknesses with decreased end-diastolic and end-systolic diameters proved the development of concentric left ventricular hypertrophy. In CKD, the septal e' was significantly decreased and E/e' increased indicating the developemnt of diastolic dysfunction. These parameters were significantly improved by NRG-1 treatment. Mechanistically, NRG-1 treatment reduced the expression of inflammatory cytokines in compared to untreat group. Furthermore, TGF-β induced α-SMA and Col I upregulation was markedly reduced by hrNRG-1 treatment.

Conclusions

NRG-1 treatment improved both renal and cardiac funtion in CKD, via a mechansim including the anti-inflammatory and anti-fibrotic properties of NRG-1.

Funding Acknowledgement

Type of funding source: Foundation. Main funding source(s): Österreichischer Austauschdienst

[Management of malignant pericardial effusion with parasternal fenestration]

Numerous methods exist for the treatment of pericardial effusions. These methods, however, can be applied with limitations only for long-term eradication of malignant pericardial effusion. Lately, several new methods, including minimally invasive procedures, have been published, and the VATS technique has become fairly popular. This technique needs special instruments and single lung ventilation, which is relatively risky in case of contralateral malignancy. We apply a new and simple minimally invasive fenestration method using the well-known approach of the parasternal mediastinoscopy by Stemmer. No recurrence of pericardial effusions was noted in long-term follow-up. In the past 10 years 73 patients were treated for pericardial effusion in our department and 22 pericardium fenestrations have been performed with parasternal approach. This method is recommended for the definitive treatment of pericardial effusion with malignant origin.

Matrix metalloproteinase activity assays: Importance of zymography

INTRODUCTION

Matrix metalloproteinases (MMPs) are zinc-dependent endopeptidases capable of degrading extracellular matrix, including the basement membrane. MMPs are associated with various physiological processes such as morphogenesis, angiogenesis, and tissue repair. Moreover, due to the novel non-matrix related intra- and extracellular targets of MMPs, dysregulation of MMP activity has been implicated in a number of acute and chronic pathological processes, such as arthritis, acute myocardial infarction, chronic heart failure, chronic obstructive pulmonary disease, inflammation, and cancer metastasis. MMPs are considered as viable drug targets in the therapy of the above diseases.

METHODS

For the development of selective MMP inhibitor molecules, reliable methods are necessary for target validation and lead development. Here, we discuss the major methods used for MMP assays, focusing on substrate zymography. We highlight some problems frequently encountered during sample preparations, electrophoresis, and data analysis of zymograms.

RESULTS AND DISCUSSION

Zymography is a widely used technique to study extracellular matrix-degrading enzymes, such as MMPs, from tissue extracts, cell cultures, serum or urine. This simple and sensitive technique identifies MMPs by the degradation of their substrate and by their molecular weight and therefore helps to understand the widespread role of MMPs in different pathologies and cellular pathways.

Active management of post-renal transplantation BK virus nephropathy: preliminary report

OBJECTIVE

To assess the efficacy of leflunomide, intravenous immunoglobulins, and ciprofloxacin as active treatment of postrenal transplant BK virus nephropathy (BKVN) in graft outcome at 1 year.

PATIENTS AND METHODS

Renal transplant recipients with positive results of 2 BK virus polymerase chain reaction tests of urine and blood underwent graft biopsy to confirm BKVN. If BKVN was diagnosed, antimetabolite therapy (mycophenolate mofetil or azathioprine) was changed to leflunomide therapy accompanied by a course of immunoglobulin and oral ciproflxacin.

RESULTS

Of 18 patients evaluated, 72% were men. Nine patients received cadaveric organs, with a mean of 3.6 HLA mismatches. All patients received induction thereapy (61% thymoglobulin), and 61% received antirejection therapy before BKVN was diagnosed. Maintenance immunosuppression therapy was primarily with prednisolone (94%); mycophenolate mofetil, 2 g/d (94%); and tacrolimus (61%). At baseline, mean (SD) creatinine clearance was 35.6 (11.5) mL/min/1.73(2), which decreased to 29.3 (17.3) mL/min/1.73(2) at 1 year (P = .01). Patients were divided into 2 groups of 9 each according to creatinine clearance values. In group 1, baseline value was 44.5 (6.6) mL/min/1.73(2), compared with 25.36 (7.8) mL/min/1.73(2) in group 2, which decreased to 42.66 (12.8) mL/min/1.73(2) (P = .23) and 16.76 (9.0) mL/min/1.73(2) (P = .009), respectively, at 1 year. Three grafts (16.7%) were lost by the end of the study, all in group 2 (P = .03).

CONCLUSION

Late diagnosis and intensive immunosuppression predispose to BKVN. Early active treatment of BKVN may improve graft outcome at 1 year posttransplantation.

Targets, receptors and effects of muscarinic neuromodulation on giant neurones of the rat dorsal cochlear nucleus

Although cholinergic modulation of the cochlear nucleus (CN) is functionally important, neither its cellular consequences nor the types of receptors conveying it are precisely known. The aim of this work was to characterise the cholinergic effects on giant cells of the CN, using electrophysiology and quantitative polymerase chain reaction. Application of the cholinergic agonist carbachol increased the spontaneous activity of the giant cells; which was partly the consequence of the reduction in a K(+) conductance. This effect was mediated via M4 and M3 receptors. Cholinergic modulation also affected the synaptic transmission targeting the giant cells. Excitatory synaptic currents evoked by the stimulation of the superficial and deep regions of the CN were sensitive to cholinergic modulation: the amplitude of the first postsynaptic current was reduced, and the short-term depression was also altered. These changes were mediated via M3 receptors alone and via the combination of M4, M2 and M3 receptors, when the superficial and deep layers, respectively, were activated. Inhibitory synaptic currents evoked from the superficial layer showed short-term depression, but they were unaffected by carbachol. In contrast, inhibitory currents triggered by the activation of the deep parts exhibited no significant short-term depression, but they were highly sensitive to cholinergic activation, which was mediated via M3 receptors. Our results indicate that pre- and postsynaptic muscarinic receptors mediate cholinergic modulation on giant cells. The present findings shed light on the cellular mechanisms of a tonic cholinergic modulation in the CN, which may become particularly important in evoking contralateral excitatory responses under certain pathological conditions.

Purkinje-like cells of the rat cochlear nucleus: a combined functional and morphological study

Purkinje-like cells (PLCs) of the cochlear nucleus (CN) are strongly calbindin positive neurones with unknown function. In the present work functional and morphological methods have been employed to provide data about PLCs in general, and about their possible involvement in the synaptic organisation of the CN in particular. PLCs had slightly elongated soma, from which a complex dendritic arborisation extended with highly variable dimensions. On the basis of their morphology, three classes of PLCs were identified. Positively identified PLCs fired a train of action potentials on sustained depolarization. When hyperpolarizing stimuli were applied, the presence of a slowly activating, ZD7288-sensitive inward current was noted that corresponded to the h-current. PLCs received both excitatory and inhibitory synaptic inputs. Functional experiments revealed that 76% and 14% of the spontaneous inhibitory postsynaptic currents recorded from the cell bodies of the PLCs were mediated via glycinergic and GABAergic synapses, respectively. PLCs presented strong cerebellin1-like immunoreactivity, but its distribution differed from that seen in cerebellar Purkinje cells. Our results indicate that PLCs are parts of the synaptic circuitry of the CN, thus they may be actively involved in the processing and analysis of auditory information.

Cytoplasmic Ca(2+) concentration changes evoked by cholinergic stimulation in primary astrocyte cultures prepared from the rat cochlear nucleus

The involvement of astrocytes in the cholinergic modulation of the cochlear nucleus has been studied using primary astrocyte cultures prepared from this nucleus. The cells were loaded with the membrane permeable form of the fluorescent Ca(2+) indicator Fluo-4, and carbachol-induced Ca(2+) concentration increases were monitored using an imaging system. In the presence of cholinergic stimulation 36.3% of the cells produced Ca(2+) transients. The time course of the transients was variable; 45.0% of the responding cells showed only a rapid Ca(2+) concentration increase, while in 50.5% of the astrocytes the fast component was followed by a slow plateau phase. Using muscarine as well as general and more specific cholinergic antagonists (atropine, pirenzepine, 4-DAMP and hexamethonium), the role of the M3 and (to a smaller extent) M1 muscarinic acetylcholine receptors could be demonstrated in the genesis of the carbachol-induced Ca(2+) transients. The presence of these two subtypes of muscarinic receptors has been confirmed at both mRNA (Q-PCR) and protein (immunocytochemistry) levels. Our data demonstrate the responsiveness of the cochlear astrocytes towards cholinergic stimulation, suggesting that they may have roles in mediating the effects of cholinergic modulation in the rat cochlear nucleus.

Adenovirus gastroenteritis in Hungary, 2003-2006

The incidence and type distribution of enteric human adenoviruses (HAds) among diarrheic children in south-western Hungary was investigated from 2003 through 2006. Laboratory studies were conducted using commercial antigen detection tests (latex agglutination or immunochromatography), polymerase chain reaction (PCR) amplification, single-strand conformation polymorphism, and sequencing and phylogenetic analysis of a conservative region of the HAd hexon gene. The overall rate of HAd infection in childhood gastroenteritis cases during the 4-year study was 8.1%, with a gradual decrease in detection rates from 11.7% in 2003 to 5.7% in 2006. Molecular studies of a subset of HAd-positive samples found that enteric HAd type 40 strains were identified only in 2003 and 2004, while HAd type 41 strains were identified throughout the 4-year study. Higher detection rates of non-enteric HAds was documented during the first half of the study period when latex agglutination was used in our laboratory for detection. Our study suggests that the choice of diagnostic method may profoundly influence the epidemiologic picture and disease burden attributed to enteric HAd infections.

Spiral ganglion neurones: an overview of morphology, firing behaviour, ionic channels and function

The spiral ganglion cells provide the afferent innervation of the hair cells of the organ of Corti. Ninety-five percent of these cells (termed type I spiral ganglion neurones) are in synaptic contact with the inner hair cells, whereas about 5% of them are type II cells, which are responsible for the sensory innervation of the outer hair cells. To understand the function of the spiral ganglion neurones, it is important to explore their membrane properties, understand their activity patterns and describe the variety of ionic channels determining their behaviour. In this review, a brief description is given of the various experimental methods that allow the investigation of the spiral ganglion cells, followed by the discussion of their action potential firing patterns and ionic conductances. The presence, distribution and significance of the K(+) currents of the spiral ganglion cells are specifically addressed, along with the introduction of the putative subunit compositions of the relevant voltage-gated K(+) channels.

Voltage-gated K+ channel (Kv) subunit expression of the guinea pig spiral ganglion cells studied in a newly developed cochlear free-floating preparation

The spiral ganglion accommodates the cell bodies of the acoustic nerve fibres connecting the hair cells to the central nervous system. As the ionic channels containing various voltage-gated K+ channel (Kv) subunits play pivotal roles in determining the functional properties and firing behaviour of the spiral ganglion cells (SGCs), every piece of information concerning the Kv expression of the SGCs is valuable. In the present work a comprehensive immunohistochemical analysis was performed to describe the expression of 9 Kv subunits in the guinea pig cochlea on traditional wax-embedded sections as well as employing a newly developed preparation that allowed confocal analysis, reconstruction of the three-dimensional appearance and precise morphological characterisation of the SGCs. Besides determining their Kv expression patterns, differences between type I and type II SGCs were sought. SGCs showed positivity for 8 out of the 9 Kv subunit-specific antibodies with varying intensity and proportion of the immunopositive cells; whereas no obvious Kv3.2 positivity could be noted. Type I and type II cells demonstrated similar expression patterns for all subunits tested, with the exception of Kv1.2, whose presence was confirmed in only 50% of the type II cells. Although the present findings suggest that type I and type II cells do not differ fundamentally in the Kv subunits they possess; they also imply that SGCs may not form a homogeneous cell population, and might provide explanation of the previously noted heterogeneity of the membrane properties of the SGCs.

Voltage-gated potassium channel (Kv) subunits expressed in the rat cochlear nucleus

Because the neuronal membrane properties and firing characteristics are crucially affected by the depolarization-activated K(+) channel (Kv) subunits, data about the Kv distribution may provide useful information regarding the functionality of the neurons situated in the cochlear nucleus (CN). Using immunohistochemistry in free-floating slices, the distribution of seven Kv subunits was described in the rat CN. Positive labeling was observed for Kv1.1, 1.2, 1.6, 3.1, 3.4, 4.2, and 4.3 subunits. Giant and octopus neurons showed particularly strong immunopositivity for Kv3.1; octopus neurons showed intense Kv1.1- and 1.2-specific reactions also. In the latter case, an age-dependent change of the expression pattern was also documented; although both young and older animals produced definite labeling for Kv1.2, the intensity of the reaction increased in older animals and was accompanied with the translocation of the Kv1.2 subunits to the cell surface membrane. The granule cell layer exhibited strong Kv4.2-specific immunopositivity, and markedly Kv4.2-positive glomerular synapses were also seen. It was found that neither giant nor pyramidal cells were uniform in terms of their Kv expression patterns. Our data provide new information about the Kv expression of the CN and also suggest potential functional heterogeneity of the giant and pyramidal cells.

Human astroviruses in raw sewage samples in Hungary

AIMS

Routine procedures for monitoring viruses in water samples have not been drawn up for the water-microbiology screening panel. Enteric viruses, including astroviruses, are able to persist under environmental conditions and may cause public health problems by contaminating natural and drinking water resources. The aim of this study was to detect human astroviruses (HAstVs) from raw wastewater samples.

METHODS AND RESULTS

To obtain data on whether human astroviruses are shed in the environment, 35 raw sewage samples from 22 sewage plants in different regions of Baranya County, Hungary were tested for astrovirus using a polyethylene glycol method for concentration and a guanidinium thiocyanate-silica procedure for extraction of viral RNA. Reverse transcription-polymerase chain reaction (RT-PCR) with HAstV-specific primer pairs was used for amplification and the specificity of amplicons was confirmed by nucleotide sequencing and phylogenetic analysis. Among the 35 raw sewage samples, 15 (43%) contained HAstV and by sequence analysis, 10 genotype HAstV-1 and one genotype HAstV-2 were identified.

CONCLUSIONS

The high detection rate of astroviruses we encountered in this study provide convincing evidence that HAstVs circulate at a relatively high frequency in the Hungarian population. No correlation between the standard indicators of faecal pollution and the presence of HAstVs was found.

SIGNIFICANCE AND IMPACT OF THE STUDY

Our study is the first report on detection of HAstV in sewage in Hungary and suggests that HAstV might be potent indicators of viral pollution in environmental specimens.

[Changes in the treatment strategy of primary gastric lymphoma]

Nowadays the management strategy for primary gastric lymphoma is undergoing change due to the effectiveness of chemotherapy and immunotherapy. While earlier surgical resection was the primary treatment and chemotherapy was only a follow-on procedure, at the present time this arrangement seems to have been reversed. Early stage low-grade MALT lymphoma can be treated with Helicobacter pylori eradication. Total or subtotal gastrectomy with D2 lymphadenectomy and with adjuvant chemotherapy in R1 situation is proposed up to stage II.1. The strategy is similar in the case of high-grade gastric lymphoma, but resection is useful only in those cases when one can be assured the result will be an R0 situation. With the exception of these cases, the only indication for resection is chemo-resistance. There is no reason for operating in advanced stages of the disease. The only purpose can be to manage complications. Unfortunately, the exact diagnosis is difficult. The diagnosis of lymphoma can often only be made after the operation. In the 6-year period between 1st January 2000 and 31st December 2005 we treated 38 patients for primary gastric lymphoma. Altogether 9 patients were operated on. Resection was performed in 6 cases. The diagnosis of lymphoma was known preoperatively only in one case. Nowadays surgery seems to be only secondary to chemotherapy and immuno-chemotherapy in the treatment of primary gastric MALT lymphoma. Our own cases also mirror this change.

Survival and causes of death in 366 Hungarian patients with systemic sclerosis

OBJECTIVE

Survival analysis of a series of 366 consecutive patients with systemic sclerosis (SSc).

METHODS

Clinical and laboratory data were evaluated from 1983 until 2005 using a standard protocol. The female/male ratio was 315/51. The mean (SD) age of the patients was 56.8 (12.2) years. The duration of disease was 12 (5-19) years with a median follow-up of 6 (3-12) years.

RESULTS

Kaplan-Meier univariate analysis showed that renal, cardiac involvement, pigmentation disturbances, malabsorption, a forced vital capacity <50%, diffuse scleroderma, presence of early malignancy, anaemia, and increased erythrocyte sedimentation rate (ESR) were signs of unfavourable prognosis, whereas anti-centromere antibodies were indicators of a good survival. In the multivariate Cox proportional hazards model the presence of diffuse scleroderma, renal involvement, coexistence of a malignant disease, and increased ESR were poor independent prognostic signs. Elderly age at the onset of disease also caused an unfavourable outcome. A total of 86 SSc-related deaths were recorded during the follow-up. Of them, 65% were attributed to cardiorespiratory manifestation of disease. Tumour associated early death was found in 12 cases (14%).

CONCLUSIONS

In addition to the well-known factors influencing the outcome (diffuse subset, internal organ involvements, and inflammatory signs), the coexistence of scleroderma with a malignancy also causes a poor outcome.

Endothelial dysfunction precedes atherosclerosis in systemic sclerosis--relevance for prevention of vascular complications

OBJECTIVES

The pathogenesis of systemic sclerosis (SSc) includes vasculopathy with endothelial dysfunction. The aim of this study was to investigate endothelium-dependent, flow-mediated dilatation (FMD), as well as endothelium-independent, nitroglycerin-mediated dilatation (NMD) of the brachial artery and to assess common carotid intimal-medial thickness (ccIMT) in SSc patients compared with healthy controls.

METHODS

FMD and NMD of the brachial artery were determined using high-resolution ultrasound imaging and the values were expressed as percentage change from baseline in 29 SSc patients and 29 healthy controls. The two groups were very similar regarding sex, age and traditional cardiovascular risk factors. In addition, common carotid arteries were assessed by duplex colour ultrasound, ccIMT determined using high resolution ultrasound and expressed in mm thickness in the same patients and controls. Correlations between FMD, NMD, ccIMT, age and the SSc subtype (diffuse or limited form) were analysed.

RESULTS

In the 29 SSc patients (mean age: 51.8 yrs), the FMD was significantly lower (4.82 +/- 3.76%) in comparison with the controls (8.86 +/- 3.56%) (P < 0.001). No difference was found in NMD between patients (19.13 +/- 17.68%) and controls (13.13 +/- 10.40%) (P > 0.1). There was a tendency of increased ccIMT in SSc patients (0.67 +/- 0.26 mm) compared with healthy subjects (0.57 +/- 0.09), but this difference was not significant (P = 0.067). A significant, positive correlation between ccIMT and age in SSc (r = 0.470, P = 0.013) was detected, as well as in healthy controls (r = 0.61, P = 0.003), but no correlation was found between FMD and age. In addition, ccIMT, but not FMD and NMD, displayed significant correlation with disease duration (r = 0.472, P = 0.011). NMD displayed significant inverse correlation with the age in SSc patients (r = -0.492, P = 0.012), but not in controls. We did not find any correlation between FMD, NMD, ccIMT and SSc subtype.

CONCLUSIONS

There is an impairment of endothelium-dependent vasodilatation indicated by low FMD in SSc. At the same time, the endothelium-independent dilatation assessed by NMD is still preserved giving an opportunity of nitroglycerine therapy. Carotid atherosclerosis indicated by ccIMT may occur at higher ages and after longer disease duration. Thus, the assessment of FMD in the pre-atherosclerotic stage may have a beneficial diagnostic, prognostic and therapeutic relevance.

Genotypic characterization of rotaviruses and prevalence of serotype-specific serum antibodies in children in Kuwait

There are no data on the serotypes of rotaviruses prevalent in Kuwait, which has a large expatriate population and hence a focal point for transmission of pathogens. The serotype information will contribute to the fund of knowledge on the world epidemiology of rotavirus serotypes and will predict the outcome of vaccination in Kuwait. Of the 75 rotavirus-positive samples from 172 children (aged <5 years) with severe diarrhoea, 69 were genotyped. The distribution of genotypes was G1 (63.8%) followed by G9 (10.2%), G2 (7.3%), G4 (7.3%) and G3 (4.4%). Among the P types, P[8] was the most common type found across all G types. By fluorescent focus neutralization test, serum antibodies to genotypes G1 (94%), G4 (68%) and G9 (46%) were found in 120 other children. These results show that G1 is the predominant serotype in Kuwait and that a vaccine that contains G1 will be most effective.

Enteric caliciviruses in domestic pigs in Hungary

Caliciviruses closely related to human norovirus and sapovirus were recently detected in domestic pigs, causing discussions about the animal reservoir and the potential for zoonotic transmission to humans. To detect porcine caliciviruses, 17 fecal samples collected on two swine farms in southwestern Hungary were tested by reverse transcription-polymerase chain reaction. Three (17.6%) samples were positive for caliciviruses. This study confirms the presence of caliciviruses, both porcine sapovirus (genus Sapovirus) and porcine norovirus (genus Norovirus), in domestic pigs in Hungary and provides additional information on the viral genetic diversity and relationship to viruses referred to as human caliciviruses.

Increase in norovirus circulation in Hungary in October-November 2006

From January to November 2006, 223 norovirus outbreaks were reported in Hungary. For 128 out of 223 outbreaks (57%) the norovirus agent was laboratory confirmed

Rhodamine backfilling and confocal microscopy as a tool for the unambiguous identification of neuronal cell types: a study of the neurones of the rat cochlear nucleus

Adequate interpretation of the functional data characterising the projection neurones of the cochlear nucleus (CN) is impossible without the unequivocal classification of these cell types at the end of the experiments. In this study, morphological criteria applicable for unambiguous identification of CN neurones have been sought. The neurones were labelled with rhodamine from incisions severing the projection pathways of the individual cell types, allowing their selective labelling and morphological characterisation. Confocal microscopy was employed for the investigation of the rhodamine-filled cells whose morphology was assessed after reconstructing the three-dimensional images of the cell bodies and proximal processes. The diameters of the somata and the number of processes originating from the cell bodies were also determined. In most of the cases, unambiguous identification of the bushy, octopus and Purkinje-like cells was relatively straightforward. On the other hand, precise classification of the pyramidal cells was often difficult, especially because giant cells could easily possess morphological features resembling pyramidal neurones. Occasionally, giant cells also mimicked the appearance of octopus neurones, which may be another important source of identification error, especially as these two cell types are often situated close to each other in the CN. It is concluded that morphological criteria defined in the present work may be effectively applied for the unambiguous identification of the projection neurones of the CN, even following functional measurements, when the correct cell classification is essential for the interpretation of the experimental data. Moreover, the present study also confirmed that Purkinje-like cells project to the cerebellum.

Prevalence and molecular characterization of human group C rotaviruses in Hungary

BACKGROUND

Group C rotaviruses are recognized enteric pathogens of humans and animals. Human group C rotaviruses have been associated with sporadic episodes and large outbreaks of gastroenteritis in children and adults but their epidemiology and ecology are still unexplored.

OBJECTIVES

To collect epidemiological data on group C rotavirus infections among children with gastroenteritis in Hungary and perform molecular characterization on the identified strains.

STUDY DESIGN

Fecal samples were collected during the 2003 surveillance in Baranya County, Hungary. The presence of group C rotavirus RNA was investigated by polyacrylamide gel electrophoresis and by reverse transcription-nested polymerase chain reaction for the VP6 gene. The identified strains were further characterized by sequencing and phylogenetic analysis of the VP7, VP6, VP4, and NSP4 genes.

RESULTS

Three of 472 samples (0.6%) tested positive for group C rotavirus. Two samples were selected for molecular analysis. Strains BaC 6104/03 and BaC 11549/03 displayed an overall identity of >99.8% and 99.3% at the nucleotide and amino acid level, respectively. The VP7 of the strain BaC 6104/03 was most closely related (99.5% aa) to the Nigerian strain Jajeri, while the VP4s of strains BaC 6104/03 and BaC 11549/03 were more similar (98.1% aa) to strains Belem and 208, detected in Brazil and China, respectively.

CONCLUSIONS

Based on this 1-year study, we conclude that group C rotaviruses are not of epidemiological relevance in the etiology of childhood acute gastroenteritis in Hungary. The low sequence divergence between the Hungarian strains suggested that a single group C rotavirus strain circulated in this period in the study area.

Melanoma cells exhibit strong intracellular TASK-3-specific immunopositivity in both tissue sections and cell culture

Amplification of the kcnk9 gene and overexpression of the encoded channel protein (TASK-3) seems to be involved in carcinogenesis. In the present work, TASK-3 expression of melanoma cells has been studied. For the investigation of TASK-3-specific immunolabelling, a monoclonal antibody has been developed and applied along with two, commercially available polyclonal antibodies targeting different epitopes of the channel protein. Both primary and metastatic melanoma cells proved to be TASK-3 positive, showing prominent intracellular TASK-3-specific labelling; mostly concentrating around or in the proximity of the nuclei. The immunoreaction was associated with the nuclear envelope, and with the processes of the cells and it was also present in the cell surface membrane. Specificity of the immunolabelling was confirmed by Western blot and transfection experiments. As TASK-3 immunopositivity of benign melanocytes could also be demonstrated, the presence or absence of TASK-3 channels cannot differentiate between malignant and non-malignant melanocytic tumours.

The antifungal protein AFP secreted by Aspergillus giganteus does not cause detrimental effects on certain mammalian cells

The antifungal protein AFP is a small, cystein-rich protein secreted by the imperfect ascomycete Aspergillus giganteus. The protein efficiently inhibits the growth of filamentous fungi, including a variety of serious human and plant pathogens mainly of the genera Aspergillus and Fusarium, whereas AFP does not affect the growth of yeast and bacteria. This restricted susceptibility range makes it very attractive for medical or biotechnological use to combat fungal infection and contamination. We, therefore, analyzed whether AFP affects the growth or function of a number of mammalian cells. Here we show that the protein neither provokes any cytotoxic effects on human endothelial cells isolated from the umbilical vein nor activates the immune system. Moreover, potassium currents of neurons and astrocytes do not change in the presence of AFP and neither excitatory processes nor the intracellular calcium homeostasis of cultured skeletal muscle myotubes are affected by AFP. Our data, therefore, suggest that AFP is indeed a promising candidate for the therapeutic or biotechnological use as a potential antifungal agent.

BK virus nephropathy in renal transplant recipients in Kuwait: a preliminary report

INTRODUCTION

BK virus nephropathy (BKVN) is a significant cause of graft loss among renal transplant recipients. The treatment outcomes of BKVN have been variably reported in the literature.

PATIENTS AND METHODS

We prospectively investigated BKV infection and BKVN among a population of renal transplant recipients with suspected BKV infection. The 42 subjects who all had acute allograft dysfunction, were categorized in three groups: those with clinical, laboratory, and histological findings that did not suggest acute rejection, drug toxicity, or obstruction (group 1, n = 24); those with findings that suggested probable acute cellular rejection but did not respond to antirejection treatment (group 2, n = 10); and those whose renal histology suggested BKVN (group 3, n = 8). Polymerase chain reaction analysis was done to detect BKV DNA in urine and blood samples from each subject. BKV DNA was detected in 19 (45%) urine samples with 11 of these subjects (26.1% of total) having BK viremia as well.

RESULTS

No evidence of BKVN was detected histologically in seven subjects with isolated BK viruria, while the others proved to be JC virus infections. Among the 11 subjects with BK viremia, eight had BKVN based on renal histology at the time of diagnosis with BKV infection, while the other three subsequently developed histological features of BKVN. BKVN developed after 5.3 +/- 2.5 (2 to 44) months after transplantation. The serum creatinine at time of BKVN diagnosis was 158.9 +/- 58 (87 to 285) micromol/L. All subjects were initially treated with a 50% reduction in immunosuppressive drug doses. Further decreases in immunosuppression were performed in all patients with close monitoring of renal function. All subjects were followed up for a of 18.2 +/- 5 (12 to 26) months. Two grafts were lost not due to BKVN, and one patient was lost to follow-up during this period. The latest serum creatinine in eight recipients is 113 + 20 (81 to 138) micromol/L, which is better than the renal function at diagnosis.

CONCLUSION

The prevalence of BKVN in suspected BKV infection was 26%. Although the study period was short (30 months), BK viremia strongly correlated with BKVN, which seemed to be successfully treated with reduction in immunosuppression.

Presence and distribution of three calcium binding proteins in projection neurons of the adult rat cochlear nucleus

The presence and distribution of three cytoplasmic calcium binding proteins, calbindin, calretinin, and parvalbumin, have been investigated in the projection neurons of the cochlear nucleus complex in adult rats by using immunohistochemistry in free-floating slices. Identification of the individual cell types was carried out on the basis of their intranuclear localization, morphological characteristics, and (in the cases of pyramidal and bushy neurons) by retrograde labeling with rhodamine-dextran. The most important findings were confirmed by using confocal microscopy. The data obtained in these experiments are the first to demonstrate the presence of parvalbumin in pyramidal neurons and globular and spherical bushy cells of rat cochlear nucleus, whereas octopus and giant cells did not show positivity for parvalbumin. Calretinin was not present in either Purkinje-like cells or giant neurons. According to the double immunolabeling co-localization experiments, the pyramidal neurons, Purkinje-like cells, globular bushy cells, and octopus cells express two different calcium binding proteins in their cytoplasm (although in different combinations) whereas giant cells and spherical bushy cells contain solely calbindin and parvalbumin, respectively. The presence of calretinin in globular bushy cells provides a tool for distinguishing them from spherical bushy cells. The immunolabeling of the fibers and axonal endings of the acoustic nerve in the ventral part of the cochlear nucleus indicated that these structures are also parvalbumin positive. It is concluded that the heterogenous cell composition of the cochlear nucleus is accompanied by a rather complex expression pattern of the cytoplasmic calcium binding proteins.

TASK-3 immunoreactivity shows differential distribution in the human gastrointestinal tract

The presence and distribution of TASK-3 immunopositivity (a channel with potential oncogenic significance) was investigated in the human gastrointestinal system. The immunohistochemical reactions were performed with two commercially available polyclonal antibodies, targeting different epitopes of the channel protein. Experiments conducted on frozen and formalin-fixed samples indicated that the application of a suitable antigen retrieval (AR) technique was essential to produce consistent, strong and reproducible TASK-3-specific immunolabelling of the formalin-fixed tissue. The lack of or inappropriate selection of the AR resulted in false-negative reactions. As for the distribution of the TASK-3 channels, strong immunolabelling was observed in the gastric and large intestinal mucosa, with particularly prominent immunoreactivity of the epithelial cells. In contrast, the smooth-muscle layers demonstrated weak TASK-3 positivity. Intense TASK-3 expression was noted in both the exocrine and endocrine pancreas, but the islets of Langerhans exhibited more powerful reactions. The ductal apparatus of the submandibular gland and lymphocytes situated in pericolonic lymph nodes were also TASK-3 positive. Strong TASK-3 positivity could also be observed in malignant gastrointestinal tumours, with intense nuclear-perinuclear labelling of some of the tumour cells. The present findings suggest that TASK-3 channels may have roles in the gastrointestinal functions, including insular hormone secretion.

The Penicillium chrysogenum-derived antifungal peptide shows no toxic effects on mammalian cells in the intended therapeutic concentration

Certain filamentous fungi, such as the penicillin-producing strain Penicillium chrysogenum, secrete small, highly basic and cysteine-rich proteins with antifungal effects. Affected fungi include a number of important zoopathogens, including those infecting humans. Recent studies, however, have pointed to a membrane-perturbing effect of these antifungal compounds, apparent as a potassium efflux from affected fungal cells. If present on mammalian cells, this would severely hinder the potential therapeutic use of these molecules. Here we studied the effects of the P. chrysogenum-derived antifungal peptide (PAF) on a number of mammalian cells to establish whether the protein has any cytotoxic effects, alters transmembrane currents on excitable cells or activates the immune system. PAF, in a concentration range of 2-100 mug/ml, did not cause any cytotoxicity on human endothelial cells from the umbilical vein. Applied at 10 mug/ml, it also failed to modify voltage-gated potassium channels of neurones, skeletal muscle fibers, and astrocytes. PAF also left the hyperpolarization-activated non-specific cationic current (I(h)) and the L-type calcium current unaffected. Finally, up to 2 mug/ml, PAF did not induce the production of pro-inflammatory cytokines such as IL-6, IL-8, and TNF-alpha. These results suggest that PAF should have only minor, if any, effects on mammalian cells in the intended therapeutic concentration range.

Survey of rotavirus infection in a Hungarian paediatric hospital. A short communication

In anticipation of a future vaccination program against rotavirus disease, a longitudinal survey has been set up to evaluate the epidemiologic features of rotavirus infections. In this report hospitalisation data and serotyping results are compiled from an epidemiologic survey conducted in Baranya County, Hungary. It was found that rotavirus-associated hospitalisation constituted a major part of infectious gastroenteritis cases (range, 14.9% to 28.5%). A higher proportion of rotavirus-positive cases was recorded when the serotype of predominant strains changed from G1 (1996-1999) to G4 (1999-2000), however, due to the short time period it was not possible to demonstrate a firm association between serotype prevalence and rotavirus-associated hospitalisation rate. In the future, such studies might help to understand if serotype-specific immunity against rotavirus infection plays an important role at the population level and if (re-)emerging rotavirus strains make an impact on the annual disease burden.

[Lung biopsy using mediastinoscope in the time of VATS]

Patients with diffuse lung disease need lung biopsy for accurate diagnosis and treatment. Both traditional open lung biopsy through a thoracotomy and video assisted thoracoscopic lung biopsy are effective methods for obtaining parenchymal samples. The authors present their surgical method and experience. Thirty patients were operated on for lung biopsy using mediastinoscope between 1999-2003. Lung parenchymal samples were eligible for histological examination. No serious postoperative complications developed. The method is simple, safe and low-cost.

[The role of bronchoscopy in examination and treatment of esophageal tumours]

The role of bronchoscopy in examination and treatment of esophageal tumours. The esophageal tumours are diagnosed in many cases in inoperable stage, and if a surgical resolution is possible, it's a heroic, great operation with high mortality rates and poor results. The involvement of great airways should be explored preoperatively by imaging methods, but bronchoscopy is also mandatory. The authors report their one year's experience of 121 bronchoscopic examinations in esophageal cancer patients. The finding was negative in 40.5% of all examinations, and 29.7% was concerned the cancer propagation to bronchial system. 29.8% of all examinations resulted a suspicion of propagation. The opinion of bronchologist can be decisive postoperatively if a fistula is suspected, or after an esophageal stent implantation airway symptoms occur. Bronchoscopy is a standard method for removal of airway excretion. The author's overview is comparing their fifteen years experience with international literature.

[Surgical complications of esophageal resections: our experience with 168 operations]

We performed 346 operations for oesophageal cancer between 1 June 1991 and 31 May 2001. 168 of them were resections. The resection rate was 48.5 percent. The most frequently performed operation was subtotal resection of the oesophagus with the removal of paraesophageal lymph nodes. Reconstruction was usually performed with gastric tube pulled up retrosternally according to Akiyama with cervical oesophago-gastrostomy (135/168). In 24 patients intrathoracic oesophago-gastrostomy and in 9 patients other type of reconstruction was performed. Considerable co-morbidity was present in 88 percent of our patients (148/168). Alcohol dependency was noted in 88 patients however we suspect there were patients who did not admit alcohol abuse. Extended resection i.e. other organs' resection together with the oesophagus was performed in 59 patients. Postoperative recovery was uneventful in 49.4 percent (83/168) of our patients. Surgical complications occurred in 28.6 percent. Anastomotic leak was observed in 21 cases (12.5 percent). The most severe complication was necrosis of an organ used in reconstruction (7 patients, 4.2 percent). 23 patients (13.7 percent) died in the postoperative period, 7 of them (4.2 percent) because of surgical complication. Statistical analysis proved that the R status and the extension of resection had no influence on the frequency of complications and mortality rate except for when the removal of the entire stomach or gastric stump was performed in one sitting with the oesophageal resection. The frequency of anastomotic leakage is grossly affected by the anastomosis technique and whether it was in cervical or in thoracic position.

Glutamate-induced cytoplasmic Ca2+ transients in neurones isolated from the rat dorsal cochlear nucleus

Extracellular application of glutamate elicited cytoplasmic Ca2+ transients in freshly dissociated rat neurones of the dorsal cochlear nucleus (DCN) (identified as pyramidal cells) with half-maximal concentration of 513 micromol/l while saturating doses (5 mmol/l) of this neurotransmitter caused transients of 46.1 +/- 3.0 nmol/l on an average. The genesis of these glutamate-evoked Ca2+ transients required extracellular Ca2+. When [Mg2+]o was 1 mmol/l, the NMDA receptor antagonist AP5 (100 micromol/l) had no effects while 100 micromol/l CNQX and 10 micromol/l NBQX, inhibitors of the AMPA receptors, greatly decreased the glutamate-induced Ca2+ transients (a decrease of 92 and 57%, respectively). When facilitating the activation of the NMDA receptors (50 micromol/l glycine, 20 micromol/l [Mg2+]o) in the presence of 100 micromol/l CNQX, Ca2+ transients of 55.4 +/- 13.1 nmol/l could be produced. Block of the voltage-gated Ca2+ channels (200 micromol/l Cd2+) decreased the Ca2+ transients to approx. 50%. The data indicate that under our control experimental circumstances the glutamate-induced Ca2+ transients of the isolated DCN neurones are produced mainly by Ca2+ entry through voltage-gated Ca2+ channels and AMPA receptors. However, when the activation of the NMDA receptors may take place, these receptors also contribute significantly to the genesis of the glutamate-evoked cytoplasmic [Ca2+] elevations.

Operation technique and healing process of telescopic ileocolostomy in dogs

The healing process of telescopic anastomoses was found in an animal experiment with 12 mongrel dogs. After the division of vessels an ileal segment of different length was invaginated into the lumen of the colon using single-layer interrupted sutures. The following four groups were used: Group A (n = 3): end-to-side ileocolostomy, single-layer interrupted suture (invagination length: 0 mm), survival time: 21 days. Group B (n = 3): invagination length: 20 mm, survival time: 7 days. Group C (n = 3): invagination length: 10 mm, survival time: 21 days. Group D (n = 3): invagination length: 20 mm, survival time: 21 days. At the end of the above survival times the anastomosis area was removed. The bursting pressure was measured and morphological as well as histological examinations were performed. In each case the 0-day look-alikes of anastomoses were performed using the remnant bowels, and bursting pressure measurements were done on these models as well. Anastomosis leakage did not occur. The serosal layer of the intracolonic part of the ileum disappeared during the healing process. The free surface of the intracolonic ileal segment became covered by the sliding mucosa of the colon and the prolapsing mucosa of the ileum. The following could be concluded after the experiments: The inner pressure tolerance of a telescopic ileocolostomy promptly after preparation is better than in case of another single-layer anastomosis. This fact results in increased safety against leakage on the first postoperative days. The inner pressure tolerance of the telescopic ileocolostomy increases during the healing process and it does not depend on the length of the invaginated part (0 day-20 mm: 56 mmHg +/- 6, Group A: 252 +/- 39, Group B: 154 +/- 19, Group C: 249 +/- 20, Group D: 298 +/- 2). There is no difference in pressure tolerance between the telescopic and the end-to-side single-layer interrupted anastomoses after the healing process. The invaginated section within the lumen of the large intestine does not suffer ischaemic or any other kind of damage. This inexpensive and simple anastomosis technique could be useful in the veterinary surgical practice as well.

HCN channels contribute to the intrinsic activity of cochlear pyramidal cells

A hyperpolarization-activated current recorded from the pyramidal cells of the dorsal cochlear nucleus was investigated in the present study by using 150- to 200-microm-thick brain slices prepared from 6- to 14-day-old Wistar rats. The pyramidal neurones exhibited a slowly activating inward current on hyperpolarization. The reversal potential of this component was -32 +/- 3 mV (mean +/- SE, n = 6), while its half-activation voltage was -99 +/- 1 mV with a slope factor of 10.9 +/- 0.4 mV (n = 27). This current was highly sensitive to the extracellular application of both 1 mM Cs+ and 10 microM ZD7288. The electrophysiological properties and the pharmacological sensitivity of this current indicated that it corresponded to a hyperpolarization-activated non-specific cationic current (Ih). Our experiments showed that there was a correlation between the availability of the h-current and the spontaneous activity of the pyramidal cells, suggesting that this conductance acts as a pacemaker current in these neurones. Immunocytochemical experiments were also conducted on freshly isolated pyramidal cells to demonstrate the possible subunit composition of the channels responsible for the genesis of the pyramidal h-current. These investigations indicated the presence of HCN1, HCN2 and HCN4 subunits in the pyramidal cells.

Cellular regulatory mechanisms influencing the activity of the cochlear nucleus: a review

The cochlear nucleus is the site in the auditory pathway where the primary sensory information carried by the fibres of the acoustic nerve is transmitted to the second-order neurones. According to the generally accepted view this transmission is not a simple relay process but is considered as the first stage where the decoding of the auditory information begins. This notion is based on the diverse neurone composition and highly ordered structure of the nucleus, on the complex electrophysiological properties and activity patterns of the neurones, on the activity of local and descending modulatory mechanisms and on the presence of a highly sophisticated intracellular Ca2+ homeostasis. This review puts emphasis on introducing the experimental findings supporting the above statements and on the questions which should be answered in order to gain a better understanding of the function of the cochlear nucleus.

Detection of human rotavirus serotype G6 in Hungary

During an ongoing survey of human rotavirus serotypes, we demonstrated for the first time the circulation of serotype G6 in two regions of Hungary. Of five rotavirus seasons surveyed to date (1994-9), serotype G6 was found in all seasons except 1994-5 at an overall prevalence of 1.4% (17 of 1252) and ranging from 0.6 to 4.5%. Children infected with G6 strains were older (mean age, 3.3 years) than children infected with the four (G1-G4) globally common serotypes (mean age, 2.1 years; unpaired Student's t test, P<0.001). Our data indicate that rotavirus serotype G6 may be an epidemiologically important G serotype in Hungary.

Antiprothrombin and antiannexin V antibodies imply risk of thrombosis in patients with systemic autoimmune diseases

OBJECTIVE

To investigate the relationship between antiprothrombin (aPT) and antiannexin V (aANX) autoantibodies of IgG isotype and thrombosis in patients with systemic autoimmune diseases. To compare the clinical relevance of these antibodies to that of anticardiolipin (aCL), anti-beta2-glycoprotein I antibodies (anti-beta2-GPI), and lupus anticoagulant (LAC).

METHODS

Serum IgG aPT, aANX, aCL, and anti-beta2-GPI levels were measured by solid phase enzyme immunoassay in the sera of 70 patients with systemic autoimmune diseases, 35 with antiphospholipid syndrome (APS) and 35 without APS. Medical records were analyzed, and associations of the antibodies with clinical features of APS were assessed.

RESULTS

Patients with APS had higher frequency of aPT (p = 0.001) and aANX (p = 0.002) compared to patients without APS. Thrombotic events occurred more frequently in those with aPT or aANX than those without (p = 0.005, p = 0.006, respectively). The presence of aPT and aANX was found to be highly specific for APS.

CONCLUSION

Measurement of aPT and aANX antibodies may be of value in confirming the diagnosis of APS, and in evaluating risk of venous and arterial thrombosis in patients with systemic autoimmune diseases.

Differential effects of tetracaine on charge movements and Ca2+ signals in frog skeletal muscle

The effects of tetracaine on charge movements and on antipyrylazo III signals monitoring intracellular delta [Ca2+] were compared in cut frog semitendinosus muscle fibers in a single vaseline gap-voltage clamp. Low tetracaine concentrations (25-40 microM) markedly reduced delta [Ca2+] signals and shifted the rheobase. However, they neither influenced charge movement nor that peak delta [Ca2+] value associated with the contractile threshold. Higher tetracaine concentrations (100-200 microM) partly inhibited charge movements in cut fibers. They separated a steeply voltage-sensitive charge, some of whose features resembled 'q gamma' reported in intact fibers, and whose movement preceded delta [Ca2+] signals at threshold. These findings: (a) directly confirm an earlier suggestion that tetracaine acts on steps in excitation-contraction coupling rather than myofilament activation; (b) show that tetracaine at low concentrations can directly interfere with sarcoplasmic reticular calcium release without modifying charge movement; (c) show that the tetracaine-sensitive charge, first found in intact fibers, also exists in cut fibers; and (d) make it unlikely that tetracaine-sensitive charge transfer is a consequence of Ca2+ release as suggested on earlier occasions.

Simultaneous recording of calcium transients in skeletal muscle using high- and low-affinity calcium indicators

To monitor cytosolic [Ca2+] over a wide range of concentrations in functioning skeletal muscle cells, we have used simultaneously the rapid but relatively low affinity calcium indicator antipyrylazo III (AP III) and the slower but higher affinity indicator fura-2 in single frog twitch fibers cut at both ends and voltage clamped with a double vaseline gap system. When both dyes were added to the end pool solution the cytosolic fura-2 concentration reached a steady level equal to the end pool concentration within approximately 2.5 h, a time when the AP III concentration was still increasing. For depolarizing pulses of increasing amplitude, the fura-2 fluorescence signal approached saturation when the simultaneously recorded AP III absorbance change was far from saturation. Comparison of simultaneously recorded fura-2 and AP III signals indicated that the mean values of the on and off rate constants for calcium binding to fura-2 in 18 muscle fibers were 1.49 x 10(8) M-1 s-1 and 11.9 s-1, respectively (mean KD = 89 nM), if all AP III in the fiber is assumed to behave as in calibrating solution and to be in instantaneous equilibrium with [Ca2+]. [Ca2+] transients calculated from the fura-2 signals using these rate constants were consistent with the [Ca2+] transients calculated from the AP III signals. Resting [Ca2+] or small changes in [Ca2+] which could not be reliably monitored with AP III could be monitored with fura-2 with little or no interference from changes in [Mg2+] or from intrinsic signals. The fura-2 signal was also less sensitive to movement artifacts than the AP III signal. After a [Ca2+] transient the fura-2 signal demonstrated a relatively small elevation of [Ca2+] that was maintained for many seconds.

A simple assay based on HIV infection preventing the reclustering of MT-4 cells

This report confirms and extends the recent work of Pauwels et al. on a "reclustering" assay (a simple microtitration plate method) for the determination of human immuno-deficiency virus (HIV) infection of MT-4 cells. MT-4 cells, which are highly susceptible to and permissive for HIV, typically grow in clusters. In the absence of virus these cell aggregates, after dissociation by pipetting, reform into clusters within 2 to 3 hours. Growth of HIV results in an inhibition of reclustering, with an end-point some 4-5 days after initiation of infection. In cultures inoculated with 5 to 8 TCID(50) of HIV, only 2-4% of the cells remain viable after 4 days. Correspondingly, HIV antigens can be detected by immunofluorescence in more than 90% of the cells remaining in the culture. The sensitivity of the "reclustering" assay is only slightly less than that of the immunofluorescence test. A colorimetric assay is also described that employs a tetrazolium salt (designated as MTT) to measure the cytolytic effect of various dilutions of HIV; comparable virus titres were obtained. This reclustering assay now appears to offer the simplest method for titration of prototype HIV in virus stocks and when used in drug evaluation tests and for measurement of HIV neutralizing antibodies.