Bacterial populations colonizing and degrading rice straw in anoxic paddy soil

Rice straw is a major substrate for the production of methane, a greenhouse gas, in flooded rice fields. The bacterial community degrading rice straw under anoxic conditions was investigated with molecular methods. Rice straw was incubated in paddy soil anaerobically for 71 days. Denaturing gradient gel electrophoresis (DGGE) of the amplified bacterial 16S rRNA genes showed that the composition of the bacterial community changed during the first 15 days but then was stable until the end of incubation. Fifteen DGGE bands with different signal intensities were excised, cloned, and sequenced. In addition, DNA was extracted from straw incubated for 1 and 29 days and the bacterial 16S rRNA genes were amplified and cloned. From these clone libraries 16 clones with different electrophoretic mobilities on a DGGE gel were sequenced. From a total of 31 clones, 20 belonged to different phylogenetic clusters of the clostridia, i.e., clostridial clusters I (14 clones), III (1 clone), IV (1 clone), and XIVa (4 clones). One clone fell also within the clostridia but could not be affiliated to one of the clostridial clusters. Ten clones grouped closely with the genera Bacillus (3 clones), Nitrosospira (1 clone), Fluoribacter (1 clones), and Acidobacterium (2 clones) and with clone sequences previously obtained from rice field soil (3 clones). The relative abundances of various phylogenetic groups in the rice straw-colonizing community were determined by fluorescence in situ hybridization (FISH). Bacteria were detached from the incubated rice straw with an efficiency of about 80 to 90%, as determined by dot blot hybridization of 16S rRNA in extract and residue. The number of active (i.e., a sufficient number of ribosomes) Bacteria detected with a general eubacterial probe (Eub338) after 8 days of incubation was 61% of the total cell counts. This percentage decreased to 17% after 29 days of incubation. Most (55%) of the active cells on day 8 belonged to the genus Clostridium, mainly to clostridial clusters I (24%), III (6%), and XIVa (24%). An additional 5% belonged to the Cytophaga-Flavobacterium cluster of the Cytophaga-Flavobacterium-Bacteroides phylum, 4% belonged to the alpha, beta, and gamma Proteobacteria, and 1.3% belonged to the Bacillus subbranch of the gram-positive bacteria with a low G+C content. The results show that the bacterial community colonizing and decomposing rice straw developed during the first 15 days of incubation and was dominated by members of different clostridial clusters, especially clusters I, III, and XIVa.

Factor structure of the Reynolds Adolescent Depression Scale in a sample of school-based adolescents

Depression is a common health problem in the adolescent population. The Reynolds Adolescent Depression Scale (RADS) is used to measure depression in clinical and community adolescent samples. Although there is available evidence for the reliability and validity of the RADS, there is insufficient documentation of its factor structure. This study examined the factor structure of the RADS in adolescent boys and girls (m-144). Internal consistency reliability ranged from .91 to .94 based on grade level, and was .91 for boys and .93 for girls. Factor analysis resulted in a 5-factor solution. Interpretation of factors were as follows: (a) Factor I--generalized demoralization; (b) Factor II--despondency and worry; (c) Factor III--externalized somatocism; (d) Factor IV--anhedonia; and, (e) Factor V--self-worth.

Ultrasonic assessment of physiological echo-contrast agent distribution in brain parenchyma with transient response second harmonic imaging

OBJECTIVES

The present study was designed to provide normal data of transient response second harmonic imaging (TRSHI) examinations of cerebral echo contrast enhancement using different modes of electrocardiogram (ECG) gating and echo-contrast agent doses.

MATERIALS AND METHODS

Fifty-five patients were examined in an axial diencephalic plane of section using the transtemporal acoustic bone window. TRSHI examinations (ECG gating: systolic, frame-rate once every 2 cardiac cycles = "basical instrument setting") could be performed in 50 individuals with adequate insonation conditions after application of 4 g of a galactose-based microbubbles suspension in a concentration of 400 mg/ml. For comparison, diastolic ECG gating (20 patients), cardiac-cycle triggering frequency of once every 2 seconds (15 patients), or an echo contrast agent dose of 2 g Levovist (15 patients) were used. Analysis of peak intensities (PIs) and areas under the curve (AUCs) was done in posterior (region of interest [ROI]a) and anterior (ROIb) parts of the thalamus, in the lentiform nucleus (ROIc), and the white matter (ROId).

RESULTS

In 41 patients with basical instrument setting, characteristic time intensity curve (TIC) could be detected in all ROIs. In ROIa (90%) and ROIb (82%), focal contrast enhancement was most difficult to visualize, and in ROIc and ROId, characteristic TICs were observable in more than 90% of the examinations. Background subtracted PIs and AUCs were significantly higher in ROIc (mean PI: 12.2 +/- 8 acoustic units [AUs]; mean AUC: 598.8 +/- 451.1 AU x Cardiac cycles), and ROId (11.8 +/- 6.9; 559.2 +/- 404) as compared to ROIa (8.3 +/- 5.2; 368.9 +/- 242.7) and ROIb (7.1 +/- 4.7; 298.2 +/- 199.1) (P < .0001). Values for corresponding examinations with a diastolic ECG gating and a cardiac cycle triggering frequency of once every 2 seconds were not different as compared to the basical instrument setting. A 4 g Levovist dose increased the portion of typical TIC in all ROIs. PI of 4 g examinations were significantly higher in ROId and ROIb as compared to the 2 g examination.

CONCLUSION

Our findings indicate that TRSHI allows noninvasive assessment of focal cerebral contrast enhancement in the majority of patients with adequate insonation conditions. This study provides data about normal quantitative and qualitative TRSHI values in patients without cerebrovascular diseases. A dose of 4 g Levovist is recommended in those individuals with inaccurate echo contrast enhancement using the 2 g dose.

Diagnosis and ablation of atrial flutter using a high resolution, noncontact mapping system

The ablation of atrial flutter can sometimes be time consuming and unsuccessful using conventional catheter techniques especially in patients with recurrences after previous ablation procedures. Simultaneous high resolution mapping from multiple sites may overcome some of the limitations. Therefore, a new high resolution noncontact mapping system was used for diagnosis and ablation of atrial flutter in 15 patients. The mapping system consists of a catheter-mounted multielectrode array, an amplifier, and a computer workstation. Far-field potentials recorded by the multielectrode catheter are amplified, digitized, and sampled at 1.2 kHz, and digitally filtered to construct high resolution activation maps during tachycardia. Ablation catheters can be steered to target sites without fluoroscopy. In 12 of the 15 patients the analysis of the activation sequence during tachycardia showed a counter-clockwise, and in 1 of 15 patients a clockwise, rotating wavefront using the isthmus as part of the reentrant circuit. In two patients no tachycardia could be induced. In 3 of the 15 patients with previous conventional ablation procedures the gap in the line of block in the isthmus region was identified and marked on the animation model. The isthmus in the right atrium was ablated and isthmus block verified by the mapping system in all patients. No complications were observed. No recurrences of atrial flutter occurred during follow-up of 4 +/- 1.7 months. The total procedure and fluoroscopy time was 171 +/- 50.0 minutes and 24 +/- 12.7 minutes, respectively. In conclusion, the use of the new high resolution noncontact mapping system in patients with right atrial flutter is safe and highly effective. In patients with previously failed conventional ablation procedures the use of a noncontact mapping system may facilitate the identification of the gap in the line of block in the isthmus region and reablation of atrial flutter.

Phytochemical investigation of Aglaia andamanica

Four new compounds, the limonoid 24-epi-melianodiol (8), the tirucallane aglaiodiol (9), and the two cyclopentatetrahydrobenzopyran derivatives pyramidaglain A (11) and B (12) were isolated from the leaves of Aglaia andamanica Hiern (Meliaceae), together with the eleven known constituents beta-sitosterol, beta-sitosterol glucoside, cycloart-23E-ene-3 beta,25-diol (1), three flavonoids 5-hydroxy-3,4',7-trimethoxyflavone (2), retusin (3) and pachypodol (4), the tirucallane 24-epi-piscidinol A (5), the lignan yangambin (6), the limonoid melianodiol (7), the bisamide pyramidatine (10) and the amino acid N-methyl-trans-4-hydroxy-L-proline (13). All structures were established by means of detailed spectroscopic analysis.

Mutations in the chloride channel gene, CLCNKB, leading to a mixed Bartter-Gitelman phenotype

Gitelman syndrome is an inherited renal disorder characterized by impaired NaCl reabsorption in the distal convoluted tubule and secondary hypokalemic alkalosis. In clinical practice, it is distinguished from other hypokalemic tubulopathies by the presence of both hypomagnesemia and normocalcemic hypocalciuria. To date, only mutations in a single gene encoding the thiazide-sensitive NaCl cotransporter have been found as the molecular basis of GS. We describe three unrelated patients presenting with the typical laboratory findings of GS. Mutational analysis in these patients revealed no abnormality in the SLC12A3 gene. Instead, all patients were found to carry previously described mutations in the CLCNKB gene, which encodes the kidney-specific chloride channel ClC-Kb, raising the possibility of genetic heterogeneity. Review of the medical histories revealed manifestation of the disease within the first year of life in all cases. Clinical presentation included episodes of dehydration, weakness, and failure to thrive, much more suggestive of classic Bartter syndrome than of GS. The coexistence of hypomagnesemia and hypocalciuria was not present from the beginning. In the follow-up, however, a drop of both parameters below normal range was a consistent finding reflecting a transition from cBS to GS phenotype. The phenotypic overlap may indicate a physiologic cooperation of the apical thiazide-sensitive NaCl cotransporter and the basolateral chloride channel for salt reabsorption in the distal convoluted tubule.

Atypical distal renal tubular acidosis confirmed by mutation analysis

In autosomal dominant distal renal tubular acidosis type I (dRTA) impaired hydrogen ion secretion is associated with metabolic acidosis, hyperchloremic hypokalemia, hypercalciuria, nephrocalcinosis, and/or nephrolithiasis. A retardation of growth is commonly observed. In this report we present a family with autosomal dominant dRTA with an atypical and discordant clinical picture. The father presented with severe nephrocalcinosis, nephrolithiasis, and isosthenuria but metabolic acidosis was absent. His 6-year-old daughter, however, suffered from metabolic acidosis, hypokalemia, and hypercalciuria. In addition, sonography revealed multiple bilateral renal cysts but no nephrocalcinosis. Mutation analysis of the AE1 gene coding for the renal Cl-/HCO3(-)-exchanger AE1 displayed a heterozygous Arg589Cys exchange in both patients but not in the healthy family members. This point mutation is frequently associated with autosomal dominant dRTA. Diagnosis of autosomal dominant dRTA is supported in this family by results of AE1 mutation analysis.

Ultrasonic evaluation of pathological brain perfusion in acute stroke using second harmonic imaging

OBJECTIVE

To evaluate the use of transient response second harmonic imaging (HI) by means of ultrasound to assess abnormalities of cerebral echo contrast agent enhancement in patients with acute stroke.

METHODS

The study comprised 25 patients with acute onset of hemispheric stroke (<24 h) with sufficient insonation conditions and 14 control subjects without cerebrovascular disease. All stroke patients had HI, extracranial and transcranial colour coded duplex examinations of the arteries supplying the brain, and clinical examinations (European stroke scale) performed in the acute phase, on day 2, and within 1 week. Acute CT was repeated within 1 week and facultatively accompanied by angiography. Examinations using HI were performed in an axial diencephalic plane of section using the transtemporal acoustic bone window. After bolus application of galactose based microbubbles, 61 ultrasound images with a cardiac cycling triggering frequency of once every 2 seconds were recorded and evaluated off line. Focal perfusion deficit was identified if no contrast enhancement was visualised in a circumscribed region of interest and insufficient temporal bone window was excluded. In cases of reappearance of contrast enhancement reperfusion was assessed.

RESULTS

Adequate cerebral contrast enhancement could be seen in 21 subjects. In seven, a large hemispheric deficit of contrast enhancement affecting the entire middle cerebral artery (MCA) territory was detectable; the lentiform nucleus was affected in three subjects. Assessment of cerebral contrast abnormalities was possible in two patients with superficial MCA infarctions but in none of the patients with lacunar ischaemias. None of the control persons had focal deficits of cerebral echo contrast enhancement. In all patients with complete MCA infarction and striatocapsular infarction, presumed ischaemic areas in HI examinations correlated with final CT findings. Overall sensitivity and specifity of HI examinations for predicting size and localisation of the infarction were 75 and 100%, respectively. During follow up, reappearance of contrast enhancement was determined in three patients, in two patients circulatory arrest due to malignant brain oedema with missing contrast enhancement in the entire cerebral hemisphere could be seen. Extent of contrast enhancement deficits significantly correlated with the clinical status on admission and after 1 week (p<0.01).

CONCLUSIONS

Second harmonic imaging is the first ultrasonic technique that enables visualisation of pathological cerebral echo contrast enhancement. Because this method identifies deficits of focal contrast enhancement in patients with acute stroke and allows estimation of the final infarct size and clinical prognosis, it may help to select and monitor patients for invasive therapies.

High incidence of sudden death with conduction system and myocardial disease due to lamins A and C gene mutation

We studied 54 living relatives from a large French kindred, among which 17 members presented with a cardiomyopathy transmitted on an autosomal dominant mode. Five of these individuals had clinical manifestations of muscle disease phenotypically consistent with Emery-Dreifuss muscular dystrophy. Genetic analysis of this kindred had demonstrated a nonsense mutation in the LMNA gene located on chromosome 1q11-q23. This gene encodes lamins A and C, proteins of the nuclear lamina located on the inner face of the nuclear envelope. We retrospectively determined the cause of death of 15 deceased family members, 8 of whom had died suddenly, 2 as a first and single manifestation of the disease. The six other cases had histories of arrhythmias and left ventricular dysfunction before dying suddenly, and three of them died despite the prior implantation of a permanent pacemaker. The mean age of onset of cardiac symptoms among affected living family members was 33 years (range 15-47 years), and the first symptoms were due to marked atrioventricular conduction defects or sinus dysfunction, requiring the implantation of permanent pacemakers in seven cases. Myocardial dysfunction accompanied by ventricular arrhythmias developed rapidly in the course of the disease and resulted in severe dilated cardiomyopathy requiring cardiac transplantation in three cases. In conclusion, in patients presenting a life-threatening familial or sporadic cardiac restricted phenotype similar to that described here, mutations in the lamins A and C gene should be looked for. In the genotypically affected individuals, cardiological and electrophysiological follow-up should be performed to prevent sudden death that could occur rapidly in the evolution of such disease.

A proposed aquatic plant community biotic index for wisconsin lakes

The Aquatic Macrophyte Community Index (AMCI) is a multipurpose tool developed to assess the biological quality of aquatic plant communities in lakes. It can be used to specifically analyze aquatic plant communities or as part of a multimetric system to assess overall lake quality for regulatory, planning, management, educational, or research purposes. The components of the index are maximum depth of plant growth; percentage of the littoral zone vegetated; Simpson's diversity index; the relative frequencies of submersed, sensitive, and exotic species; and taxa number. Each parameter was scaled based on data distributions from a statewide database, and scaled values were totaled for the AMCI value. AMCI values were grouped and tested by ecoregion and lake type (natural lakes and impoundments) to define quality on a regional basis. This analysis suggested that aquatic plant communities are divided into four groups: (1) Northern Lakes and Forests lakes and impoundments, (2) North-Central Hardwood Forests lakes and impoundments, (3) Southeastern Wisconsin Till Plains lakes, and (4) Southeastern Wisconsin Till Plains impoundments, Driftless Area Lakes, and Mississippi River Backwater lakes. AMCI values decline from group 1 to group 4 and reflect general water quality and human use trends in Wisconsin. The upper quartile of AMCI values in any region are the highest quality or benchmark plant communities. The interquartile range consists of normally impacted communities for the region and the lower quartile contains severely impacted or degraded plant communities. When AMCI values were applied to case studies, the values reflected known impacts to the lakes. However, quality criteria cannot be used uncritically, especially in lakes that initially have low nutrient levels.

Cultured porcine urinary bladder epithelial cells as a screening model for genotoxic effects of aromatic amines: characterisation and application of the cell culture model

Isolated epithelial cells from porcine urinary bladders were maintained in dividing long-term monolayer cultures, and were used as a model system for the urinary bladder in toxicological studies in vitro. To examine the state of differentiation during the culture period, the culture system was characterised morphologically by light and transmission electron microscopy and by immune fluorescence labelling with antibodies against cytokeratins 7,13 and pan. The cultured cells were identified as urothelial epithelium by their polarised structure, and by their expression of several uroepithelial specific morphological features, such as fusiform vesicles, tight junctions and an asymmetric apical cell membrane. Additionally, the cells were labelled with anti-cytokeratin 7,13 and pan antibodies, and negatively with anti-vimentin antibodies. The maintenance of suitable culture conditions was shown by the stable enzyme activities of (gamma-glutamyltranspeptidase, alkaline phosphatase and acid phosphatase over a culture period of 4 weeks. A good viability of the cultured cells under the chosen culture conditions was shown by the presence of low amounts of lactate dehydrogenase (< of = 5%) in the culture medium. The activities of the chosen marker enzymes for cell differentiation (gamma-glutamyltranspeptidase), lysosomes (acid phosphatase) and luminal membranes (alkaline phosphatase) were relatively stable over the observed culture period. Enzyme activities involved in metabolism of xenobiotics were determined, to define the ability for metabolism in cultured cells compared with bladder tissue in situ. Several constitutive phase I and II enzyme activities were found to be stable during the culture period, indicating that the cultured cells should be able to metabolise xenobiotics in a comparable manner to the urothelium in vivo. The cytotoxic effects of xenobiotics were investigated and IC50 values were determined by means of lactate dehydrogenase leakage and inhibition of neutral red uptake. The induction of sister chromatid exchanges was used as a parameter for the genotoxic effects of several xenobiotics. This cell culture system was found to be a very good screening system for the testing of substances that affect the bladder, especially aromatic amines.

Effect of hydroxyeicosatetraenoic acids on furosemide-sensitive chloride secretion in rat distal colon

Arachidonic acid metabolites such as prostaglandins, thromboxanes, and leukotrienes are well known modulators of intestinal vascular perfusion, motility, and electrogenic ion transport. We investigated the effect of different hydroxyeicosatetraenoic acids (HETEs) from cytochrome P450- and lipoxygenase-dependent arachidonate metabolism on electrogenic chloride secretion in rat distal colon. Using conventional Ussing techniques, basolateral 12-HETE significantly decreased basal short-circuit current (I(sc)) and inhibited furosemide-sensitive Cl(-) secretion stimulated by either dibutyryl cAMP, prostaglandin E(2), or theophylline in a concentration-dependent manner (IC(50) = 1.5 nM). These data were underlined by significant inhibition of J(net)(Cl) in unidirectional (36)Cl flux measurements. Direct regulation of the basolateral Na(+)-K(+)-2Cl(-) cotransporter or the Na-K-ATPase could be excluded because 12-HETE had no effect on furosemide-sensitive K(+) secretion induced by epinephrine, or ouabain-sensitive Na(+) reabsorption stimulated by aldosterone. Inhibitors of Ca(2+)-activated and voltage-gated K(+) channels such as apamin, charybdotoxin, and dendrotoxin did not affect secretagogue-dependent I(sc) and its regulation by 12-HETE. In contrast, glibenclamide significantly attenuated the effect of 12-HETE on secretagogue-induced I(sc), whereas chromanol 293B, an inhibitor of cAMP-dependent K(+) conductance, had an additive effect. We speculate that 12-HETE, like glibenclamide, affects intestinal Cl(-) secretion by inhibiting basolateral K(+)(ATP) channels. In contrast to these findings, neither 5-HETE nor 20-HETE had any effect on basal I(sc) or cAMP-dependent Cl(-) secretion.

Primary cell cultures of bovine colon epithelium: isolation and cell culture of colonocytes

Epithelial cells from bovine colon were isolated by mechanical preparation combined with an enzymatic digestion from colon specimens derived from freshly slaughtered animals. After digestion with collagenase I, the isolated tissue was centrifuged on a 2% D-sorbitol gradient to separate epithelial crypts which were seeded in collagen I-coated culture flasks. By using colon crypts and omitting the seeding of single cells a contamination by fibroblasts was prevented. The cells proliferated under the chosen culture conditions and formed monolayer cultures which were maintained for several weeks, including subcultivation steps. A population doubling time of about 21 hr was estimated in the log phase of the corresponding growth curve. During the culture period the cells were characterized morphologically and enzymatically. By using antibodies against cytokeratine 7 and 13 the isolated cells were identified as cells of epithelial origin. Antibodies against vimentin served as negative control. Morphological features such as microvilli, desmosomes and tight junctions, which demonstrated the ability of the cultured cells to restore an epithelial like monolayer, were shown by ultrastructural investigations. The preservation of the secretory function of the cultured cells was demonstrated by mucine cytochemistry with alcian blue staining. A stable expression of enzyme activities over a period of 6 days in culture occurred for gamma-glutamyltranspeptidase, acid phosphatase and NADH-dehydrogenase activity under the chosen culture conditions. Activity of alkaline phosphatase decreased to about 50% of basal value after 6 days in culture. Preliminary estimations of the metabolic competence of these cells revealed cytochrome P450 1A1-associated EROD activity in freshly isolated cells which was stable over 5 days in cultured cells. Then activity decreased completely. This culture system with primary epithelial cells from the colon will be used further as a model for the colon epithelium in toxicological studies in vitro.

[Efficacy of and tolerance to prolonged release prazosin in patients with hypertension and non-insulin dependent diabetes]

The treatment of hypertension represents one of the major elements of the cardiovascular prognosis in type II diabetes. Among antihypertensive drugs, alpha blockers may be interesting because of the absence of unfavourable effects on plasma glucose and lipid levels.

OBJECTIVE

The aim of this study was to evaluate the effectiveness and the safety of prazosin osmotic tablet treatment in non-insulin-dependent diabetic patients with mild to moderate arterial hypertension.

METHODS

After an initial 4-week-single-blind placebo period, 81 hypertensive subjects (162 +/- 11/96 +/- 5 mmHg) with type II diabetes were included in the study to receive prazosin osmotic tablet (o.t) open-label therapy at the dose of 2.5 mg/day for 12 weeks. After 4 weeks of treatment the dosage of prazosin o.t was increased to 5 mg/day if the diastolic blood pressure remained > or = 90 mmHg.

RESULTS

Both supine and standing systolic and diastolic blood pressures were significantly decreased (P < 0.001) with prazosin therapy from 162 +/- 10/96 +/- 5 mmHg in supine and 160 +/- 12/95 +/- 6 mmHg in the upright position, to 149 +/- 15/86 +/- 9 mmHg and 148 +/- 16/86 +/- 9 mmHg respectively at the end of the 12-week-treatment period. There were no significant changes in the glycemic parameters (glycemia, haemoglobin A1c) during the prazosin therapy compared with baseline values. A significant decrease of triglycerides (P = 0.005), total cholesterol (P < 0.001) and LDL cholesterol (P = 0.03) levels was observed during prazosin therapy compared with the baseline measurements, whereas HDL cholesterol remained stable. Only 6% of the patients reported adverse events in relation with the study drug during the active treatment period.

CONCLUSION

This study showed a significant decrease of the blood pressure in hypertensive subjects with type II diabetes after prazosin o.t treatment, without any change of glycemic parameters. Moreover, there was a favourable evolution of the lipidic parameters during the study characterised by a significant decrease of triglycerides and total and LDL cholesterol.

DIAS I: duplex-sonographic assessment of the cerebrovascular status in acute stroke. A useful tool for future stroke trials

BACKGROUND AND PURPOSE

A number of controlled trials have evaluated the benefit of intravenous thrombolysis in acute stroke with inconsistent results. None of these studies assessed the initial vascular status or provided information regarding the recanalization rate after therapy. Further trials need to clarify whether certain subgroups might possibly benefit more than others from intravenous thrombolysis. Therefore, a fast and valid method for assessment of cerebrovascular status is needed. In this multicenter study, we evaluated the potentials and limitations of color-coded duplex sonography (TCCS) for cerebrovascular status assessment in acute stroke patients before and after therapy. Furthermore, we compared the recanalization rate for patients referred to thrombolytic and conservative medical therapy.

METHODS

Fifty-eight patients suffering from hemispheric stroke were enrolled consecutively in 8 centers. Duplex sonography was performed on admission, 2 hours after start of therapy, and 24 hours after onset of symptoms. Therapy was started within 6 hours.

RESULTS

Intravenous thrombolysis was performed in 18 patients, conservative medical therapy in 39 patients, and early thromboendarterectomy in 1 patient. The middle cerebral artery (MCA) mainstem was patent in 29 patients (53.7%), occluded in 25 (46.3%), and was not assessable in 4 patients. Recanalization of the occluded MCA after 2 and 24 hours was diagnosed in 50% and 78% of the patients treated with rtPA and in 0% and 8% in the conservatively treated patients.

CONCLUSIONS

Intravenous thrombolysis is highly effective in restoring blood flow after MCA occlusion. TCCS is suitable for assessment of the cerebrovascular status in acute stroke and therefore might define therapeutically relevant subgroups of patients in future stroke trials on the basis of their vascular pathology.

Topical acetyl salicylate and dipyrone attenuate neurogenic protein extravasation in rat skin in vivo

The effect of topically applied acetyl salicylic acid (ASA) and dipyrone on capsaicin-evoked protein extravasation was investigated by dermal microdialysis in rat. After a baseline of 75 min, capsaicin (1%) was applied epicutaneously under occlusion for 75 min above the capillaries. Topical capsaicin stimulation induced neurogenic protein extravasation with a mean increase of protein concentration in the perfusate of 165+/-27% (mean+/-SEM; n=15), whereas in sham-stimulated sites protein concentration decreased to 73+/-7% of the prestimulation value (n=6). ASA (2-200 mg/ml) and dipyrone (3-300 mg/ml) dose-dependently reduced the capsaicin induced protein extravasation to 118+/-23% (ASA, 200 mg/ml; n=8) and 72+/-9% (dipyrone, 300 mg/ml; n=8) of the prestimulation value. ASA and dipyrone antagonized the excitatory effects of capsaicin on skin nociceptors and thus suppressed the neurogenic protein extravasation.

Stochastic resonance in two-dimensional arrays of coupled nonlinear oscillators

In this Brief Report we report the results of computer simulations on the periodic and noise driving of two-dimensional square arrays of coupled nonlinear oscillators. We find significant improvement in the output of these arrays over their one-dimensional counterparts (quantified by signal-to-noise ratio in the power spectrum at the frequency of the periodic driving). We also find that, within the limited resolution of our simulations, the one-dimensional scaling laws proposed by Lindner et al. [Phys. Rev. E 53, 2081 (1996)] seem to hold quite well for two-dimensional arrays.

[Cardiac side effects of anti-HIV agents]

Both nature and prognosis of cardiac complications occurring in patients infected by the Human Immunodeficiency Virus-1 (HIV-1) have changed considerably since the introduction of highly acive and anti-retroviral triple therapy ("HART"). Opportunist cardiac infections have thus been displaced and side effects of drugs now occupy the primary aetiological role. Torsades de pointe may be exceptionally triggered by anti-infectious agents such as pentacarinat or trimethoprime-sulfamethoxazole, as are those induced by the association of ketoconazole and terfenadine or cisapride, the dangers of which are well known and the prevention more effective, especially with the association with HIV antiproteases which inhibit the cytochrome P450. The diagnosis of iatrogenic myocardial dysfunction is more difficult, except when it occurs acutely as with phosphonoformate (Foscarnet), or interleukine-2. Progressive cardiomyopathy caused by -interferon and dideoxynucleosides (zidovudine, didanosine and zalcitabine), reversible on withdrawal of the drug responsible in half the cases, should be distinguished from those due to the HIV itself (therapeutic relay) or to another associated cause (alcohol, coronary artery disease). The coronary complications of diseases treated by antiproteases usually occur in smokers whose cholesterol and triglyceride levels are rapidly increased with HAART. In a series of 9 patients (amongst 700 treated with the antiproteases), after the acute phase of myocardial infarction during which the interventional approach is often preferred, the medium-term prognosis is relatively good, on condition that the patients correct the hyperlipidaemia and give up smoking.

Sleep apnea and quality of life

OBJECTIVE

To investigate the effects of sleep apnea (SA) on the quality of life (QOL).

DESIGN

A prospective study of QOL in patients with and without SA as defined by an apnea-hypopnea index (AHI) >5.

SETTING

University-based outpatient clinics.

PATIENTS

Primary care patients followed in a general internal medicine clinic as well as those referred to a sleep disorders clinic at the University of Wisconsin Hospital and Clinics were consecutively recruited and classified into 3 groups of subjects: (1) patients without SA (AHI<5) (n=46), (2) patients with mild SA (AHI 5-15) (n=16), and (3) patients with moderate to severe SA (AHI>15) (n=21).

INTERVENTIONS

NA.

MEASUREMENTS

QOL was assessed with the Medical Outcomes Study SF-36 Health Survey. Health history and demographic data were obtained via structured interview and medical record review. All subjects underwent overnight polysomnography for diagnosis of SA.

RESULTS

After controlling for age, gender, body mass index, and number of comorbid conditions, the association between sleep apnea and QOL was significant in the domains of physical functioning and role limitation due to physical health problems (p<0.05) and was borderline in vitality (p<0.1). Patients with both mild and moderately severe SA scored significantly lower (worse) than did patients without SA in physical functioning and in role limitations due to physical-health (82 and 83 vs. 92, respectively). Moderate to severe SA subjects scored significantly lower in vitality than did subjects without SA (51 vs. 64, p<0.05). Subscales analysis revealed that subjects with moderate to severe SA had significantly lower scores that did those without SA in positive affect (69 vs. 79), current health perceptions (71 vs. 80) and vitality (50 vs. 70), p<0.05 for all comparisons. A large percentage of patients without SA had perfect scores of 100 (ceiling effect) on the physical, social, and role functioning scales.

CONCLUSIONS

SA has an independent impact on several QOL domains after adjusting for differences in age, gender, body mass index, and comorbidity. QOL outcomes were likely attenuated by ceiling effects. Disentangling the scales that measure multidimensional QOL (positive and negative aspects) enhanced the ability of the SF-36 to detect important consequences of sleep apnea on QOL.

Familial hypomagnesaemia with hypercalciuria and nephrocalcinosis maps to chromosome 3q27 and is associated with mutations in the PCLN-1 gene

Familial hypomagnesaemia with hypercalciuria and nephrocalcinosis (FHHNC, MIM 248250) is a complex renal tubular disorder characterised by hypomagnesaemia, hypercalciuria, advanced nephrocalcinosis, hyposthenuria and progressive renal failure. The mode of inheritance is autosomal recessive. A primary defect in the reabsorption of magnesium in the medullary thick ascending limb of the loop of Henle (mTAL) has been proposed to be essential in FHHNC pathophysiology. To identify the underlying genetic defect we performed linkage analysis in eight families, including three with consanguineous marriages. We found linkage to microsatellite markers on chromosome 3q27 with a maximum two-point lod score (Zmax) of 5.208 for D3S3530 without evidence for genetic heterogeneity. Haplotype analysis revealed crucial recombination events reducing the critical interval to 6.6cM. Recently, mutations in the gene PCLN-1, mapping to 3q27 and coding for paracellin-1, were identified by Simon et al (1999) as the underlying genetic defect in FHHNC. Paracellin-1 represents a renal tight junction protein predominantly expressed in the TAL. Mutational analysis in our patient cohort revealed eight different mutations in the PCLN-1 gene, within six novel mutations. In seven of 13 mutant alleles we detected a Leu151 substitution without evidence for a founder effect. Leu151 is a residue of the first extracellular loop of paracellin-1, the part of the protein expected to bridge the intercellular space and to be important for paracellular conductance. This study confirms the implication of paracellin-1 defects in FHHNC and points to a predominant role of this protein in the paracellular reabsorption of divalent cations in the TAL.

Mycophenolate mofetil decreases endothelial prostaglandin E2 in response to allogeneic T cells or cytokines

BACKGROUND

Prostaglandin E2 (PGE2) is a powerful endogenous immune suppressant and interferes with various T-cell functions. However, it is not known in detail whether immunosuppressive drugs influence the PGE2-driven immune response in transplant patients. Therefore, we investigated the effect of several immunosuppressive compounds, in particular the novel drug mycophenolate mofetil (MMF), on endothelial PGE2 release.

METHODS

Endothelial cells (HUVEC) were activated by either allogeneic CD4+ or CD8+ T cells, or by the cytokines interleukin-1 or gamma-interferon. Using an enzyme-linked immunosorbent assay, we analyzed PGE2 release of the activated HWEC in the presence of MMF, cyclosporine, or tacrolimus. As verapamil and mibefradil also possess immunosuppressive properties, they were included in the study as well.

RESULTS

Activation of HUVEC with interleukin-1 or T cells resulted in a drastic accumulation of PGE2 in the supernatant. Cyclosporine or tacrolimus had no effect on PGE2 release. However, Ca2+ channel blockers, when applied at higher dosages, caused a significant increase in PGE2. Interestingly, MMF strongly diminished the PGE2 level in the cell culture supernatant in a concentration-dependent manner.

CONCLUSION

The results demonstrate an inhibitory effect of MMF on PGE2 production, which may lower the benefits of the PGE2-triggered immune response after organ transplantation.

Prostaglandin deficiency promotes sensitization of adenylyl cyclase

Inhibition of prostaglandin synthesis by the drug indomethacin suppresses the synthesis of the cyclic AMP antagonist, prostaglandylinositol cyclic phosphate (cyclic PIP), and leads to a metabolic state comparable to type II diabetes. It was of interest whether prostaglandin-deficiency likewise causes sensitization of adenylyl cyclase, as this has been reported for the diabetic state. In liver plasma membranes of indomethacin-treated male rats, basal and forskolin-stimulated cyclic AMP synthesis remained unchanged when compared to untreated control rats. In control rats, stimulation of cyclic AMP synthesis by fluoride (2.2-fold) or glucagon (3.5-fold) was much lower than stimulation by forskolin (6.6-fold). In contrast, in indomethacin-treated rats, stimulation of cAMP synthesis by fluoride (4.6-fold) or glucagon (5.2-fold) nearly matched the stimulation by forskolin (6.4-fold). The level of alpha1-adrenergic receptors was slightly reduced, from 450 to 320 fmol/mg protein, by the indomethacin treatment. Independent of the treatment by indomethacin, stimulation of cyclic AMP synthesis by adrenaline failed, in agreement with the low density of adrenergic beta-receptors. In conclusion, PGE deficiency sensitizes adenylyl cyclase in rat liver for G protein-coupled receptors (glucagon) and also for fluoride.