Influence of nonylphenol on the microbial community of lake sediments in microcosms

In this study the impact of nonylphenol, an estrogenic degradation product of alkylphenol polyethoxylates, on the microbial community structure in contaminated sediments of aquatic microcosms using in situ hybridization with fluorescently labeled oligonucleotides probes was investigated. A positive correlation between nonylphenol concentration and cell numbers of bacteria and microfungi as well as an increase in the numbers of active bacteria was found. However, the ratio between total microorganisms and active bacteria remained unchanged. A large fraction of the cells could be identified using group specific oligonucleotide probes. A slight change in the composition of the microbial community structure was observed, with Gram-positive bacteria with high DNA G + C-content becoming more abundant at higher concentrations of nonylphenol.

Kidney function and glomerulopathy over 8 years in young patients with Type I (insulin-dependent) diabetes mellitus and microalbuminuria

AIMS/HYPOTHESIS

We aimed to investigate prospectively the interrelation between kidney function and glomerular morphological changes over 8 years in young patients with Type I (insulin-dependent) diabetes mellitus and microalbuminuria.

METHODS

Kidney biopsies were taken at baseline and after 8 years in 18 subjects who were 20 years of age (19-29 mean and range), had duration of diabetes for 11 years (7-18), and who had an albumin excretion rate of 45 microg/min (15-194). The glomerular ultrastructural parameters were analysed using stereological methods.

RESULTS

At the end of the study three patients had an increased albumin excretion rate of more than 25 % a year, two of whom developed overt nephropathy. Glomerular filtration rate declined 2.3 ml/min x 1.73 m(-2) x yr(-1). Glomerular volume, volume fractions of matrix and mesangium, and basement membrane thickness showed an increase over the 8 years. Multiple regression analysis showed that mean 8-years HbA(1 c), matrix volume fraction(baseline) and basement membrane thickness BMT(baseline) accounted for 70 % of the variation in AER at the end of the study. Mesangial volume fraction(baseline,) glomerular filtration fraction(baseline,) and mean 8-year HbA(1 c) accounted for 73 % of the change in glomerular filtration rate from baseline. Smoking was strongly associated with the glomerular filtration rate at baseline ( r = 0.65). When glomerular filtration rate(baseline) was omitted from the equation, smoking was the only significant parameter linked to the change in glomerular filtration rate from the baseline.

CONCLUSION/INTERPRETATION

In patients who had diabetes for 20 years, long-term hyperglycaemia and glomerulopathy found 8 years prior to the study, and possibly smoking, affected renal function (i. e. albumin excretion rate and glomerular filtration rate).

FADD: A link between TNF family receptors and caspases in Parkinson's disease

Fas-associating protein with a death domain (FADD) is a proximal adaptor protein of the tumor necrosis factor (TNF) receptor family death pathway. This human postmortem study showed a significant decrease in the percentage of FADD-immunoreactive dopaminergic (DA) neurons in the substantia nigra pars compacta of patients with PD compared with controls (-24.8%). This decrease correlated with the known selective vulnerability of nigral DA neurons in PD, suggesting that this pathway contributes to the susceptibility of DA neurons in PD to TNF-mediated apoptosis.

Sustained improvement of renal graft function for two years in hypertensive renal transplant recipients treated with nifedipine as compared to lisinopril

BACKGROUND

Treatment of posttransplant hypertension is still a matter of debate. Calcium antagonists may ameliorate renal side effects of cyclosporin. Angiotensin converting enzyme- (ACE) inhibitors may be more effective in sustaining renal function in native chronic renal disease. We prospectively compared the effect of controlled release nifedipine and lisinopril on long-term renal function in hypertensive kidney transplant patients treated with cyclosporin.

METHODS

A total of 154 renal transplant patients presenting with hypertension (diastolic blood pressure >or=95 mmHg) during the first 3 weeks after transplantation were randomised to receive double-blind nifedipine 30 mg or lisinopril 10 mg once daily. A total of 123 patients completed 1 year of treatment (69 nifedipine, 54 lisinopril) and 64 patients completed 2 years of double-blind treatment (39 nifedipine, 25 lisinopril). Baseline glomerular filtration rate was measured as 99 mTc-diethylene-triaminepentaacetate clearance in a stable phase 2 to 5 weeks after inclusion and repeated at 1 and 2 years.

RESULTS

Baseline glomerular filtration rates were similar (46+/-16 ml/min with nifedipine, 43+/-14 ml/min with lisinopril). The changes in glomerular filtration rates from baseline were statistically significant between the groups after 1 year (9.6 ml/min mean treatment difference (95% confidence interval [CI]s 5.5-13.7 ml/min, P=0.0001) and remained statistically significant also after 2 years (10.3 ml/min mean difference (95% CIs 4.0-16.6], P=0.0017). After 1 year glomerular filtration rates averaged 56+/-19 ml/min in the nifedipine group and 44+/-14 ml/min in the lisinopril group.

CONCLUSIONS

Both nifedipine and lisinopril were safe and effective in treatment of hypertension in renal transplant patients treated with cyclosporin. Patients receiving nifedipine but not lisinopril improved kidney transplant function over a period of 2 years.

Mortality and causes of death after first ischemic stroke: the Northern Manhattan Stroke Study

OBJECTIVE

To analyze the early and long-term causes of death after first ischemic stroke in the multiethnic northern Manhattan community.

METHODS

In the prospective, population-based Northern Manhattan Stroke Study, 980 patients with first ischemic stroke (mean age 70 years; 56% women; 49% Caribbean Hispanic, 31% black, 20% white) were followed for a mean of 3 years. Causes of death were classified as vascular (incident stroke, recurrent stroke, cardiac) or nonvascular. Life table analyses were used to assess mortality risks among different race-ethnic groups. Early (< or =1 month) vs long-term (> 1 month to 5 years) causes of death were compared.

RESULTS

Among the 980 patients followed, 278 (28%) died; 47 (5%) died during the first month. Cumulative mortality risk was 5% at 1 month, 16% after 1 year, 29% after 3 years, and 41% after 5 years. The proportion of vascular deaths among all deaths was 75% at 1 month and 43% thereafter (p = 0.001). Stroke, either incident (53%) or recurrent (4%), caused early deaths in 57% and long-term deaths in 14% (p = 0.001). Overall mortality risks did not differ significantly among race-ethnic groups. However, the proportion of incident stroke-related early deaths was 85% in Caribbean Hispanic patients, 33% in white patients, and 25% in black patients (p = 0.002).

CONCLUSIONS

Among patients with first ischemic stroke, incident stroke is the leading cause of early deaths. A large proportion of long-term deaths are nonvascular in origin. Despite similar overall mortality rates in race-ethnic groups, our data suggest a higher incident stroke-related early mortality among Caribbean Hispanics.

Efficacy of nifedipine or lisinopril in the treatment of hypertension after renal transplantation: a double-blind randomised comparative trial

Calcium channel blockers and angiotensin converting enzyme-inhibitors are commonly used in the treatment of hypertensive renal transplant recipients. The purpose of this study was to investigate if the response rate to treatment differs with these drugs in this setting. A single centre, prospective, randomised, double-blinded, comparative study to address the efficacy of controlled release nifedipine or lisinopril in the treatment of hypertension (diastolic blood pressure > or =95 mmHg) in cyclosporin (CsA)-treated renal transplant recipients was performed. Recipients were randomised to receive either lisinopril (10 mg once daily) or controlled release nifedipine (30 mg once daily). The dose was doubled on indication. The number of responders (diastolic blood pressure <90 mmHg on monotherapy) were addressed during the early post-transplant phase (first 3 months) and during a late post-transplant phase (from 3 to 12 months after renal transplantation) in the same patient population. One hundred and fifty-four patients (nifedipine=78, lisinopril=76) with untreated hypertension (diastolic blood pressure> or =95 mmHg) were randomised within 3 wk after renal transplantation. One hundred and twenty-three patients (nifedipine=69, lisinopril=54) completed the study. Fourteen (20%) nifedipine-treated recipients responded during the early, and 26 (38%) during the late post-operative phase (months 4-12 after renal transplantation). Eleven (20%) lisinopril-treated recipients responded during the early, and 18 (33%) during the late post-transplant phase. Non-responders were, on average, 8.5+/-1.5 kg heavier both in the early phase and after 1 yr of treatment (p<0.01), and 6.1+/-0.9 yr older than responders (p<0.05). In conclusion, these results indicate that both controlled release nifedipine and lisinopril are equally efficient in the treatment of post-transplant hypertension. As monotherapy, both drugs show a "response rate" of 20-38%, depending on time interval after transplantation.

Visualization of N-acylhomoserine lactone-mediated cell-cell communication between bacteria colonizing the tomato rhizosphere

Given that a large proportion of the bacteria colonizing the roots of plants is capable of producing N-acyl-L-homoserine lactone (AHL) molecules, it appears likely that these bacterial pheromones may serve as signals for communication between cells of different species. In this study, we have developed and characterized novel Gfp-based monitor strains that allow in situ visualization of AHL-mediated communication between individual cells in the plant rhizosphere. For this purpose, three Gfp-based AHL sensor plasmids that respond to different spectra of AHL molecules were transferred into AHL-negative derivatives of Pseudomonas putida IsoF and Serratia liquefaciens MG1, two strains that are capable of colonizing tomato roots. These AHL monitor strains were used to visualize communication between defined bacterial populations in the rhizosphere of axenically grown tomato plants. Furthermore, we integrated into the chromosome of AHL-negative P. putida strain F117 an AHL sensor cassette that responds to the presence of long-chain AHLs with the expression of Gfp. This monitor strain was used to demonstrate that the indigenous bacterial community colonizing the roots of tomato plants growing in nonsterile soil produces AHL molecules. The results strongly support the view that AHL signal molecules serve as a universal language for communication between the different bacterial populations of the rhizosphere consortium.

Insulin resistance after renal transplantation: impact of immunosuppressive and antihypertensive therapy

OBJECTIVE

The purpose of the present study was to validate various surrogate estimates of insulin sensitivity (IS) in a renal transplant population and to assess the influence of immunosuppressive and antihypertensive therapy on insulin resistance (IR) after renal transplantation.

RESEARCH DESIGN AND METHODS

A total of 167 consecutive renal transplant recipients without previously known diabetes underwent a 75-g oral glucose tolerance test (OGTT) 3 months after renal transplantation. A total of 43 patients also underwent a euglycemic-hyperinsulinemic glucose clamp study. Six OGTT-derived IS indexes were validated against the euglycemic-hyperinsulinemic glucose clamp-derived IS index (ISI(CLAMP)).

RESULTS

The OGTT-derived ISI(TX) correlated closely with the ISI(CLAMP) (r = 0.58, P < 0.001). The other surrogate estimates of IS were also significantly but less well correlated with the ISI(CLAMP) (Spearman's correlation; r = -0.45 to 0.41, P = 0.003-0.050). In the univariate model, BMI, daily prednisolone dose, creatinine clearance, hypertension, number of antihypertensive agents, and use of diuretics or beta-blockers were negatively associated with ISI(TX) (P < 0.05). After multiple regression analysis, BMI (P < 0.001), daily prednisolone dose (P < 0.001), cytomegalovirus infection (P = 0.030), and triglycerides (P = 0.034) were shown to be independent predictors of posttransplant IR.

CONCLUSIONS

The OGTT-derived ISI(TX) may be a useful estimate of IS in Caucasian renal transplant recipients. Increasing daily prednisolone dose is an independent predictor of IR after renal transplantation. Hypertension and the use of beta-blockers and diuretics may also deteriorate IR in this group of patients.

Naftidrofuryl in the treatment of vascular dementia

The design of this study was based on the European guidelines for the treatment of Alzheimer's disease. After a placebo run-in period of 4 weeks, patients with a diagnosis of vascular dementia (VaD) were randomised to receive either 400 mg naftidrofuryl/day, 600 mg naftidrofuryl/day or placebo for 6 months. The patients were assessed using the ADAS-cog, the SCAG, the NOSGER and the CGI item 2 scale. The primary analysis was undertaken on the ITT population. At the end of the study, significantly more patients in the treatment groups showed no deterioration on both ADAS-cog and SCAG scales compared with placebo (400 mg p = 0.005, 600mg p = 0.015). There were also significant differences between the active and placebo groups for the individual scales. This study has demonstrated that treatment with naftidrofuryl can slow the rate of deterioration of patients with vascular dementia.

Peripheral hemodialysis shunt with intracranial venous congestion

BACKGROUND

Intracranial venous congestion is often caused by local venous thrombosis or brain arteriovenous fistulas. Hemodialysis shunts are known to cause venous enlargement in the arm or chest but have not been related to intracranial vascular pathology. Case Description- A 59-year-old woman who presented with increasing headache, gait instability, and memory loss was a renal transplant recipient who still carried a left upper arm shunt. Cranial CT scan showed enlarged veins in the posterior fossa with incipient hydrocephalus. Extracranial duplex sonography revealed reversed flow in the left internal jugular vein, which normalized on cuff inflation around the shunt-carrying arm. The reversed flow, intracranial venous congestion, and neurological status improved after surgical shunt ligation.

CONCLUSIONS

To our knowledge, this is the first case description of an intracranial venous outflow obstruction caused by a peripheral arteriovenous shunt.

Bilateral pharmacokinetic interaction between cyclosporine A and atorvastatin in renal transplant recipients

Atorvastatin is increasingly used as a cholesterol-lowering agent in solid organ transplant recipients receiving cyclosporine A (CsA). However, the potential bilateral pharmacokinetic interaction between atorvastatin and CsA in renal transplant recipients has not previously been examined. Baseline 12-h CsA pharmacokinetic investigation was performed in 21 renal transplant recipients and repeated after 4 weeks of atorvastatin treatment (10 mg/ d). At week 4, 24-h pharmacokinetics of atorvastatin was also performed. All patients received basiliximab induction followed by CsA and prednisolone immunosuppression. Compared with historic controls, CsA-treated patients showed, on average, sixfold higher plasma HMG-CoA reductase inhibitory activity after 4 weeks of atorvastatin treatment (p < 0.05). Atorvastatin had a moderate effect on the pharmacokinetics of CsA and reduced the AUC0-12 (area under curve, 0-12h) by 9.5 +/- 18% (p = 0.013) and Cmax (maximal concentration) by 13.5 +/- 24% (p =0.009), while C12 (trough level) was unchanged (p =0.42). Total and LDL cholesterol decreased by 26.8 +/- 8.4% (p < 0.0001) and 41.5 +/- 11.0% (p < 0.0001), respectively. Bilateral pharmacokinetic interaction between atorvastatin and CsA resulted in sixfold higher plasma HMG-CoA reductase inhibitory activity, but only a moderate decrease in systemic exposure of CsA.

Influence of cytotoxicity and compound precipitation on test results in the alkaline comet assay

We use the comet assay as part of our genotoxicity screening battery for newly synthesized drug candidates. A dataset of more than 250 tests carried out with 75 drug candidates of various chemical classes was analyzed to elucidate the influence of cytotoxicity and compound precipitation on DNA migration in the comet assay. Using a V79 Chinese hamster cell line, 38 of the compounds were negative and 37 were positive in the comet assay. The reproducibility of test results between repeat experiments was 85%. Data on 72 tests with a negative call in which the compounds were tested up to highly cytotoxic concentrations demonstrated that cytotoxicity, as determined by Trypan blue dye exclusion and occurrence of cells with completely fragmented chromatin, did not lead to false positive test results. The majority (64.2%) of compounds with a positive call induced elevated DNA migration in the absence of excessive cytotoxicity. Compound precipitation was observed in 84 tests. In 88.1% of these cases, the test result at the precipitating concentration did not differ from that found at the highest soluble concentration. Half of the remaining 11.9% of contrary results (most of them weak effects) were not reproducible in the respective repeat experiment, indicating no or only a negligible influence of precipitation on test results. The data indicate that using V79 cells, the comet assay specifically detects genotoxic effects and is not confounded by cytotoxicity or compound precipitation under the conditions used.

Noradrenaline provides long-term protection to dopaminergic neurons by reducing oxidative stress

To better understand the neurotrophic function of the neurotransmitter noradrenaline, we have developed a model of mesencephalic cultures in which we find low concentrations (0.3-10 microM) of noradrenaline to be remarkably effective in promoting long-term survival and function of dopaminergic neurons. This protective action reproduced the effect of caspase inhibition. It was atypical in that it occurred independently of adrenoceptor activation and was mimicked by some antioxidants, redox metal chelators and the hydroxyl radical detoxifying enzyme catalase. Interestingly, intracellular reactive oxygen species (ROS) were drastically reduced by treatment with noradrenaline, indicating that the neurotransmitter itself acted as an antioxidant. Prevention of oxidative stress was, however, independent of the glutathione antioxidant defense system. Chemical analogues of noradrenaline bearing two free hydroxyl groups in the ortho position of the aromatic ring (o-catechols), as well as o-catechol itself, mimicked the survival promoting effects of the neurotransmitter, suggesting that this diphenolic structure was critical for both neuroprotection and reduction of ROS production. Paradoxically, the autoxidation of noradrenaline and the ensuing production of quinone metabolites may be required for both effects, as the neurotransmitter was spontaneously and rapidly degraded over time in the culture medium. These results support the concept that central noradrenergic mechanisms have a neuroprotective role, perhaps in part by reducing oxidative stress.

Changes of cerebral blood flow following dexamethasone treatment in brain tumour patients. A Xe/CT study

BACKGROUND

It is not exactly known how dexamethasone improves the function of brain that is affected by tumour. Whether and in what sense dexamethasone influences cerebral blood flow has rarely been addressed and previous investigations have yielded inconsistent results.

METHOD

Stable xenon-enhanced computed tomography (Xe/CT) was used to assess the regional cerebral blood flow (rCBF) in 67 patients with supratentorial primary and secondary brain tumours. rCBF studies were done at least once prior to resection or stereotactic biopsy of the tumours. In nine patients repeated studies before surgery and in 15 patients additional studies after resective surgery were obtained. Dexamethasone was administered according to the clinical needs before surgery and systematically after surgery. Of the preoperative studies 30 were obtained before and 47 during dexamethasone treatment. The rCBF data were analysed upon correlations with daily dose, cumulative dose, and duration of dexamethasone treatment. Moreover, individual courses before and after surgery were examined.

FINDINGS

Mainly inverse correlations were found between the treatment parameters, particularly the daily dose of dexamethasone, and rCBF. Only in the subgroup of glioblastoma patients, a positive correlation was found of both duration and cumulative dose of dexamethasone with rCBF in oedema. Serial observations of individual patients confirmed the above findings, yet with possible exceptions. After tumour resection a clear improvement of rCBF was regularly observed.

INTERPRETATION

The beneficial effect of dexamethasone is not attributed to an increase of cerebral blood flow, because rather decreases of rCBF are mostly observed.

Effects of fluvastatin on cardiac events in renal transplant patients: ALERT (Assessment of Lescol in Renal Transplantation) study design and baseline data

BACKGROUND

Recent clinical trials of primary and secondary prevention of cardiovascular disease have demonstrated that lowering plasma cholesterol with 3-hydroxy-3-methylglutaryl coenzyme A (HMG CoA) reductase inhibitors ('statins') reduces morbidity and mortality from coronary heart disease in diverse patient populations.

STUDY AIMS

The aim of the present ALERT (Assessment of Lescol in Renal Transplantation) study is to determine whether renal transplant recipients would also benefit from statin therapy. ALERT is a multicentre, randomized, double-blind, placebo-controlled trial to assess the effect of fluvastatin in renal transplant recipients with mild-to-moderate hypercholesterolaemia. The primary objective is to investigate the effects of fluvastatin on major adverse cardiac events (MACE). In addition, the effects on cardiovascular and all-cause mortality, as well as renal function, will be addressed.

STUDY POPULATION

The study population contains patients with functioning renal allografts of more than 6 months' duration, recruited from 75 centres in Northern Europe and Canada. Patients of both sexes, aged 30-75 years, with a total cholesterol level of 4.0-9.0 mmol/l (155-348 mg/dl) were included, except for those with a history of myocardial infarction, where the upper limit for inclusion was 7.0 mmol/l (270 mg/dl).

STUDY DESIGN

A total of 2100 patients were recruited by the end of October 1997 and will be followed for up to 6 years. This report presents the design features of the study (recruitment, follow-up, sample size, data analysis and study organization), along with baseline results. ALERT is the first large-scale prospective, randomized, double-blind study to address the prevention of cardiovascular mortality in renal transplant patients receiving an HMGCoA reductase inhibitor.

Familial and sporadic renal oncocytomas--a comparative molecular-genetic analysis

OBJECTIVES

Genetic causes of sporadic and familial renal oncocytomas are not known. We analyzed these tumors genetically in order to detect tumor-specific chromosome alterations.

METHODS

DNA from 26 sporadic and 31 familial renal oncocytomas were screened by comparative genomic hybridization according to standard protocols including degenerate oligonucleotide-primed PCR.

RESULTS

Chromosome alterations were detected in 19/26 sporadic (73%) and in 4/31 familial renal oncocytomas (13%). Partial or complete losses of chromosome 1 were most frequently found in both sporadic (15/26) and familial tumors (2/4). Less frequently, loss of chromosome 14 (3/26) was detected in sporadic renal oncocytomas as well as losses of 2p, 2q, 4q, 10 and 18 and gains of 1q and 17q in individual sporadic tumors. Inter-tumor variation of chromosome aberrations was prominent in 1 patient, where 1 tumor showed gains of chromosomes 5, 6q, 7, 10p, 12 and 13q, whereas the second tumor exhibited gains of chromosomes 5 and 7 and loss of 10q. In contrast to sporadic renal oncocytomas, most familial tumors (87%) were devoid of chromosome instabilities.

CONCLUSION

Our results demonstrate that partial or complete loss of chromosome 1 is the most common alteration in renal oncocytomas, sporadic and familial. However, chromosome changes are much rarer in familial than in sporadic renal oncocytomas.

A new type of exocrine gland and its function in mass recruitment in the ant Cylindromyrmex whymperi (Formicidae, Cerapachyinae)

Workers of the ant Cylindromyrmex whymperi display mass trail recruitment. Bioassays show that the trail pheromone originates from a unique gland between abdominal sternites 6 and 7. The gland has a hitherto unknown structural organization. Upon leaving the secretory cell, the duct cell widens to form a sclerotized pear-shaped reservoir chamber, lined with multiple duct cells. Each duct thus forms a miniature reservoir for the secretions of each single secretory cells, a novel structural arrangement in exocrine glands of social Hymenoptera.

Atorvastatin improves endothelial function in renal-transplant recipients

BACKGROUND

Hyperlipidaemia and endothelial dysfunction are common features in cyclosporin A (CsA)-treated renal transplant recipients. Endothelial dysfunction may contribute to the risk of premature atherosclerosis and cardiovascular death in these patients. A beneficial effect of statin therapy beyond cholesterol lowering may be an improvement of endothelial function. The present study was designed to assess the effect of atorvastatin on serum lipids and endothelial function in CsA treated renal transplant recipients.

METHODS

This pilot study was an open trial of 4 weeks atorvastatin (10 mg per day) treatment in renal transplant recipients (n=22). All patients received a CsA- and prednisolone-based immunosuppressive regimen. Endothelial function was assessed in the forearm skin microvasculature by acetylcholine stimulation and laser Doppler flowmetry, before and after atorvastatin treatment. Serum lipids, plasma endothelin-1 (ET-1), nitric oxide (NO), and von Willebrand factor (vWF) were also measured.

RESULTS

Both total and LDL cholesterol were significantly reduced by 26.8 +/- 8.4 and 41.5 +/- 11.0% respectively, after 4 weeks of treatment. Endothelial function was significantly improved during atorvastatin treatment, area under the flux versus time curve (AUC)(ACh) was 538 +/- 362 AU x min before and 682 +/- 276 AU x min after treatment (P=0.042). Plasma NO levels also showed a borderline significant increase from 49 +/- 30 to 57 +/- 37 micromol/l during the treatment period (P=0.051), though plasma ET-1 (0.37+/-0.08 vs 0.37+/-0.12 fmol/ml) and vW (196+/-57 vs 197+/-37%) were unchanged.

CONCLUSION

Atorvastatin lowered serum cholesterol significantly and improved endothelial function in renal transplant recipients after 4 weeks of treatment. Plasma NO levels were increased during atorvastatin treatment, indicating a possible endothelial protective effect through an "endothelial-NO pathway".

Evidence for oligoclonality and tumor spread by intraluminal seeding in multifocal urothelial carcinomas of the upper and lower urinary tract

Multifocality and recurrence of urothelial carcinoma may result from either the field effect of carcinogens leading to oligoclonal tumors or monoclonal tumor spread. Previous molecular studies, favoring the monoclonality hypothesis, are mostly limited to the urinary bladder. We investigated genetic alterations in a total of 94 synchronous or metachronous multifocal tumors from 19 patients with at least one tumor both in the upper and lower urinary tract. Loss of heterozygosity (LOH) was determined using eight markers on chromosome 9 and one marker on 17p13 (p53). Microsatellite instability was investigated at six loci and protein expression of MSH2 and MLH1 was evaluated by immunohistochemistry. In addition, exons 5-9 of the p53 gene were sequenced. Deletions at chromosome 9 were found in 73% of tumors and at 17p13 in 18% of tumors. There was no significant difference in the frequency of LOH in the upper and lower urinary tract. Deletions at 9p21 were significantly correlated with invasive tumor growth. The pattern of deletion revealed monoclonality of all tumors in nine patients. In five patients there were at least two tumor clones with different genetic alterations. In four of these patients the different clones occurred in the bladder and subsequently in the ureter and renal pelvis. All four patients with p53 mutations revealed identical mutations in all tumors. Thus, multifocal urothelial carcinomas are frequently monoclonal, whereas others show oligoclonality, providing molecular evidence for field cancerization. Intraluminal tumor cell seeding appears to be an important mechanism of multifocal occurrence and recurrence of urothelial carcinomas.

Use of the alkaline comet assay for industrial genotoxicity screening: comparative investigation with the micronucleus test

We evaluated the suitability of the alkaline comet assay as a screening test in industrial routine testing of new chemicals. Thirty-six pharmaceutical compounds with unknown genotoxic potential were tested comparatively in the comet assay and micronucleus test (MNT) using V79 Chinese hamster cells. The comparison of results is generally based on at least two independent experiments, each with two replicate cultures at a minimum of three concentrations. We found a high degree of concordance between results of the comet assay and MNT. All compounds with negative MNT results were also negative in the comet assay. All positive compounds in the comet assay were also positive in the MNT. However, 16 of 38 positive MNT results were negative in the comet assay. Some of the contrary findings may be due to aneugenic effects, which are detected in the MNT but not in the comet assay. However, the majority of the contrary results may be a consequence of cytotoxicity, which can induce elevated micronucleus frequencies but may not lead to positive effects in the comet assay. Additional data of 39 compounds tested in the Ames test and the comet assay were compared. Four of these compounds that were Ames positive were also positive in the comet assay. However, the comet assay also detected 16 compounds that were negative in the Ames test. We believe that the comet assay in vitro is a useful, fast screening system in mammalian cells that can be used in a test battery during drug development.

[Prerequisites, indications and contraindications of IV-lysis of ischemic stroke with rt-PA]

BACKGROUND AND PURPOSE

To evaluate prerequisites, safety, and efficacy of i.v.-thrombolysis of ischemic stroke with rtPA in an academic medical center.

METHODS

Over a period of 2 years and 10 months all patients admitted with a diagnosis of stroke were recruited. Inclusion and exclusion criteria for i.v.-thrombolysis were combined from large scale randomized controlled trials, the time window, however, could be extended up to 4 hours in subjects with a negative CT-scan. Prespecified outcome parameters were the modified Rankin Scale (mRS) and the Barthel Index (BI) at 3 months, and symptomatic hemorrhagic complications. Additionally, time parameters, such as onset-admission-time, door-Ct-time, door-needle time, and onset-needle time were recorded.

RESULTS

During the reported period 103 patients underwent i.v.-thrombolysis, corresponding to 14.9% of all patients with ischemic stroke, and 47% of patients with ischemic stroke arriving in < 3 hours after symptom onset. The mean baseline NIHSS was 14, the mean mRS 13 (3-34), the mean age 70 (+/- 12) years. The following time intervals were observed: Onset-admission-time 64 min., door-CT-time 27 min., admission-needle-time 80 min., and onset-needle-time 142 min. There were 4 symptomatic intracerebral hemorrhagic transformations, including 3 parenchymal hemorrhages, 2 of them lethal, and one with almost full recovery. According to the mRS, 39% of patients had a good (mRS 0-1), 72% a good to moderate recovery (mRS 0-2). The corresponding figures for the BI were 60% BI 95-100 and 72% BI > 90. The mortality was 15%.

CONCLUSION

The i.v.-thrombolysis of ischemic stroke with rt-PA demands appropriate organisation of the pre- and in-hospital phase and can be performed safely and efficaciously in daily clinical routine if inclusion and exclusion criteria as well as all safety measures during the critical phase after therapy are strictly obeyed.