Predicting natural attenuation of xylene in groundwater using a numerical model

The aquifer beneath an abandoned refinery in the Lower Rhine area, Germany, was contaminated with a number of different mineral oil products. Groundwater sampling in the area around the former xylene plant revealed that a xylene plume had developed in the underlying groundwater, and moreover, that there is strong evidence for in situ microbial xylene degradation with oxygen, nitrate, sulfate and ferric iron as electron acceptors. In order to prevent further xylene spreading, three pumping wells extracting contaminated water were installed downgradient of the spill zone. The numerical reactive transport code Transport Biochemisty Chemistry (TBC) was applied to this situation to quantify the relation of microbial degradation to xylene removal by the pumping wells. It could be shown that the unamended in situ degradation was an appreciable xylene removal process that contributed to about one-third to the total xylene removal (degradation plus extraction). A further objective of the model application was to predict xylene spreading under regional flow conditions, i.e. without operation of the three pumping wells, to consider the possible effects of natural xylene attenuation. To accomplish this, the model calibrated for the situation with operating wells was transferred to the hydraulic situation of regional flow while retaining the parameters of the biochemical model. It turned out that the xylene plume that is expected to develop downgradient of the source area will be limited to an extension of not more than 1000 m. An interesting feature of the simulations results was that xylene degradation under iron-reducing conditions, which was of minor importance for the situation with operating pumping wells, becomes the dominant degradation mechanism under regional flow conditions. Moreover, iron reduction will be the key process in controlling plume evolution. The model application illustrates that multi-species reactive transport models are needed to adequately transfer reactive processes from one hydraulic situation to another, while single species models are not suited for this predictive task.

The KEX2 gene of Candida glabrata is required for cell surface integrity

Candida glabrata has emerged as one of the most common causes of candidosis. In order to identify factors that are necessary for viability and pathogenicity of this fungal pathogen, we analysed the role of the KEX2 gene, which codes for a regulatory endoproteinase that is known to process certain virulence factors in Candida albicans. The KEX2 gene from C. glabrata was cloned and found to have 51% and 62% identity and high structural similarities to the homologous counterparts in C. albicans and Saccharomyces cerevisiae. KEX2 was expressed at all time points investigated during growth in complex medium. In order to investigate the role of this putative regulatory proteinase, Kex2-deficient mutants were produced. In addition to known kex2 phenotypes, such as pH and calcium hypersensitivity, the mutants grew in cellular aggregates and were found to be hypersensitive to several antifungal drugs that target the cell membrane, including azoles, amorolfine and amphotericin B. Ultrastructural investigation after exposure to low doses of itraconazole showed azole-specific alterations such as enlarged vacuoles and proliferation of the cytoplasmatic membrane in the kex2 mutants, but not in the control strains. In contrast, antifungals such as 5-flucytosine and hydroxypyridones inhibited growth of the kex2 mutants and the control strains to the same extent. In an in vitro model of oral candidosis, kex2 mutants showed reduced tissue damage in the presence of itraconazole compared with the control infections. These data suggest that Kex2 is involved in the processing of proteins that are essential for cell surface integrity of C. glabrata.

[Extracellular hydrolytic enzymes and their relevance during Candida albicans infections]

Candida albicans cannot only infect skin and mucosa, but can also cause life threatening systemic candidosis. While natural barriers and the immune system of healthy individuals normally prevent such infections, virulence factors exist that enable C. albicans to survive on surfaces and the permit the fungus to invade tissues and organs in immunocompromised patients. Adhesions factors, morphological flexibility and hydrolytic enzymes belong to this group of virulence factors.C.albicans appears to be able to use these specific virulence attributes at distinct stages of an infection or in different types of candidosis. For example, distinct adhension factors are important for the persistence of C. albicans on mucosal epithelial cells, while other factors are necessary for the adhesion to endothelial tissue. The differential expression of specific virulence factors at different stages of an infection could be the reason why C. albicans not only has single genes for extracellular hydrolytic enzymes, but gene families. Both secreted aspartate proteinases (Saps) and secreted lipases (Lips) from C. albicans are encoded by at least 10 different genes. This high number of similar genes might empower C. albicans with the ability to secrete a specific and appropriate enzymatic response at distinct stages of an infection. For both gene families differential expression has been shown in vitro and in vivo, which would be reasonable for such an adaptation. Expression studies revealed that distinct SAP and LIP genes were expressed under conditions when potential subtrates ( proteins or lipids) were not present in the growth medium. Such expression patterns would imply that these genes may have functions other than simply providing nutrients for the fungus. The specific transcription of single SAP genes during the course of an infection suggests that these genes may have specific functions during different stages of an infection. In fact, inhibition studies and the use of mutants with targeted gene disruptions showed that distinct SAP genes (SAP1-3) are important durning infections of skin and mucosa, while others (SAP4-6) are most relevant for systemic infections.

Cloning and expression analysis of NhL1, a gene encoding an extracellular lipase from the fungal pea pathogen Nectria haematococca MP VI (Fusarium solani f. sp. pisi) that is expressed in planta

The filamentous fungus Nectria haematococca (anamorph Fusarium solani f. sp. pisi) resides in soil, and attacks pea seedlings in the area of the underground epicotyl and upper tap root, causing foot rot disease. We detected lipase activity during in vitro growth of N. haematococca. Subsequently, a lipase gene was cloned and functionally characterised by heterologous expression in Saccharomyces cerevisiae. The full-length cDNA of 1152 bp was cloned using a 3' RACE-PCR approach coupled with cDNA library screening. The genomic clone, comprising an ORF of 999 bp interrupted by two introns of 56 and 64 bp, was isolated from a newly constructed lambda phage library. Analysis of the deduced protein sequence revealed the presence of a typical signal peptide at the N-terminus, and of the three conserved amino acids forming the active site of lipases. The lipase of N. haematococca has a low degree of similarity to the lipases from Humicola lanuginosa (37.2%), Rhizomucor miehei (21.6%), Rhizopus delemar (23.1%), Rhizopus niveus (25.9%), and to mono- and diacylglycerol lipase from Penicillium camembertii (30.8%), and very high similarity (94.6%) to a lipase from Fusarium heterosporum. The lipase from N. haematococca shows maximal activity at 37 degrees C and pH 8.0. Based on Southern analysis, the lipase clone represents a single-copy gene in N. haematococca. Expression analysis was performed by RT-PCR. In vitro, the lipase gene shows a low basal expression, but is highly inducible by lipase substrates, and repressed by glucose. During plant infection, transcripts of this fungal lipase gene were detected 4, 8, and 10 days after infection.

Optimizing ventilation-perfusion lung scintigraphy: parting with planar imaging

AIM

Of the study was to introduce and verify a ventilation-perfusion (V/Q) acquisition protocol that incorporates new developments in scintigraphy in order to allow for a more balanced comparison with other diagnostic procedures.

METHODS

In 103 patients suspect of having pulmonary embolism, V/Q scans were acquired exclusively with SPECT technique. Ventilation was done with ultrafine aerosol. Planar images in eight directions were reconstructed through addition of three consecutive SPECT projections. Three referees examined the scans in regard to type, localization, and extent of V/Q defects.

RESULTS

Using this protocol, significantly more defects, especially of subsegmental size, were detected (p < 0.01). Sensitivity, and diagnostic accuracy were also significantly improved (p < 0.01) to 0.96, and 0.99, respectively. Furthermore, kappa values were increased up to 0.82--a relevant enhancement in the ability to precisely localize V/Q defects.

CONCLUSION

In conclusion this protocol provides high-resolution tomographic scans as well as high-quality planar images within a short acquisition time. Due to the significant increase in lesion detection, sensitivity, diagnostic accuracy, and anatomical localization of defects, it is a substantial improvement in the diagnosis of pulmonary embolism that will put V/Q scintigraphy on a par with other tomographic methods.

Evaluation for Madigan's prostatectomy in patients with benign prostatic hyperplasia

AIM

To comparatively evaluate the efficacy and post-operative complications of the Madigan's prostatectomy (MPC) and suprapubic prostatectomy (SPPC).

METHODS

A total of 43 patients with benign prostatic hyperplasia were divided into two groups: 21 underwent MPC and 22, SPPC. In all the patients, the international prostate symptom score (IPSS) and urinary pressure-flow studies were assessed before and 6 months after operation. The International Continence Society (ICS) nomogram, Abrams-Griffiths (AG) number and linear passive urethral resistance relation analysis (L-PURR) were used to diagnose and grade bladder outlet obstruction (BOO). The IPSS and the urodynamic parameters before and after operation, as well as the advantages and post-operative complications were recorded and compared.

RESULTS

Patients of both the MPC and SPPC groups had a significant improvement in IPSS and urodynamic parameters. Obstruction was relieved in 81.0% of MPC and 86.4% of SPPC patients. MPC has the advantages of the absence of postoperative hematuria and post-catheter stricture, a shorter period of hospitalization, and lower incidence of retrograde ejaculation and erectile dysfunction.

CONCLUSION

Both MPC and SPPC can effectively relieve BOO. MPC has certain advantages and a lower incidence of complications as compared with SPPC.

PTK1, a mitogen-activated-protein kinase gene, is required for conidiation, appressorium formation, and pathogenicity of Pyrenophora teres on barley

Mitogen-activated protein kinases (MAPKs) are a group of protein kinases that execute a wide variety of roles in cellular signal transduction pathways such as osmoregulation, cell wall biosynthesis, growth, and differentiation. A polymerase chain reaction (PCR) with degenerate primers based on conserved regions of known MAPKs was used to clone the MAPK gene PTK1 from the leaf pathogen Pyrenophora teres (anamorph Drechslera teres), the causal agent of net blotch of barley (Hordeum vulgare L.). The predicted amino acid sequence shows high homology with MAPKs from other phytopathogenic fungi. The gene is present in the genome as a single copy. PTK1 is expressed during in vitro growth on complete medium, under conidiation-inducing conditions and during infection of barley leaves, as shown by reverse transcription-PCR studies. In order to assess the role of PTK1 in the life cycle of P. teres, targeted gene disruption was conducted. Mutants carrying an interrupted copy of the gene were deficient in conidiation, did not form appressoria on glass surfaces or on barley leaves, lost their ability to infect barley leaves, and could not colonize host tissues following artificial wounding.

[Characterization of therapy failures in radioiodine therapy of Graves' disease without simultaneous antithyroid agents]

Aim of this study was a characterization of radioiodine therapy (RIT) failures in Graves' disease without simultaneous carbimazole.

METHOD

226 patients with a confirmed diagnosis of Graves' disease received 686.8 +/- 376.4 MBq of iodine-131 orally for thyroid ablation. Target dose was 250 Gy. All patients were followed up for 6 months. Therapy failures were compared with successes regarding possible influencing variables initial thyroid volume, thyroid function, immune activity (TRAb), I-131 uptake, effective half-life, absorbed energy dose, age and gender.

RESULTS

212 of 226 patients (93.8%) were treated successfully, 14 (6.2%) showed a hyperthyroidism relapse within 6 months which required a second radioiodine therapy. A success rate of 92.5% (62/67) could also be achieved with 67 patients who were hyperthyroid at the time of RIT. Compared to the therapy successes, the 14 failures achieved significantly lower absorbed doses (223.8 +/- 76.6 Gy vs. 285.2 +/- 82.1 Gy, p < 0.005), but with no significant differences regarding age, thyroid volume, function or TRAb (all p > 0.2). Of the 14 failures, n = 8 reached an absorbed dose < 200 Gy and n = 1 a dose < 250 Gy, although 5 of the failures reached an absorbed dose of > 250 Gy. Stepwise logistic regression revealed only absorbed energy dose as a variable significantly influencing therapy success (p < 0.005), but no influence of initial thyroid volume, function, TRAb value, age (all p > 0.2) or gender (p = 0.13). Two-tailed Fisher's exact test showed no significant influence of gender on success rates (failures/successes: male 1/36, female 13/176, p = 0.48).

CONCLUSIONS

Except for the absorbed energy dose, no other significant variable influencing the outcome of radioiodine therapy in Graves' disease without simultaneous carbimazole could be found. It should be noted, though, that 5 therapy failures (2.2%) reached an absorbed energy dose of > 250 Gy.

Scoring the short form ICSmaleSF questionnaire. International Continence Society

PURPOSE

The International Continence Society (ICS) ICSmale questionnaire was devised to provide a thorough evaluation of the occurrence and bothersomeness of lower urinary tract symptoms and their impact on the lives of men with benign prostatic disease. This report completes the developmental work on the questionnaire, producing the concise short form instrument, ICSmaleSF, with a valid, reliable and scientifically justified scoring system.

MATERIALS AND METHODS

Two data sets were used. The short form version of the questionnaire was devised and initially evaluated using data on men with uncomplicated lower urinary tract symptoms who were involved in the CLasP randomized controlled trial comparing laser therapy with transurethral prostatic resection and conservative management or monitoring without active intervention. External validation of the scoring system was undertaken using data from phase II of the ICS benign prostatic hyperplasia (BPH) study, an observational study of outcome in men with lower urinary tract symptoms related to benign prostatic enlargement. All patients completed the developmental version of the ICSmale questionnaire. Parallel analysis on the CLasP data set identified items that were responsive to change or highly problematic, allowing other redundant and overlapping items to be eliminated. Factor analysis and Cronbach's alpha coefficients were used to examine the clustering of items. Regression models were used to investigate the validity of followup scores within and across treatment groups in the CLasP and ICS/BPH studies.

RESULTS

The questionnaire, which originally comprised 22 items, was shortened to 11 items in the 2 distinct factors of voiding (ICSmaleVS) and incontinence (ICSmaleIS) symptoms. Cronbach's alpha coefficients were high at 0.76 for ICSmaleVS and 0.78 for ICSmaleIS. A simple additive score was calculated by adding the 5 items in ICSmaleVS and 6 in ICSmaleIS. ICSmaleVS and ICSmaleIS detected expected improvement in the laser therapy and transurethral prostatic resection groups, and stability in the conservative management group within CLasP. Similarly each subscore but particularly ICSmaleVS was sensitive to differences in the outcome of the range of treatments in the ICS/BPH study. While frequency and nocturia were highly problematic and sensitive to change individually, they did not load into the other main factors or correlate with each other. It is suggested that these symptoms should be evaluated separately with the additional inclusion of a single item measure of the impact of lower urinary tract symptoms on daily life.

CONCLUSIONS

The ICSmaleSF represents a comprehensive, concise, valid and reliable instrument for evaluating men with lower urinary tract symptoms. Unlike other questionnaires in the field it contains subscores for the domains of voiding and incontinent symptoms as well as the separate consideration of frequency, nocturia and impact on daily life. We hope that it will become the tool of choice for the comprehensive evaluation of treatment of men with lower urinary tract symptoms associated with benign prostatic disease.

From coherently excited highly correlated states to incoherent relaxation processes in semiconductors

Recent theories of highly excited semiconductors are based on two formalisms, referring to complementary experimental conditions, the real-time nonequilibrium Green's function techniques and the coherently controlled truncation of the many-particle problem. We present a novel many-particle theory containing both of these methods as limiting cases. As a first example of its application, we investigate four-particle correlations in a strong magnetic field including dephasing resulting from the growth of incoherent one-particle distribution functions. Our results are the first rigorous solution concerning formation and decay of four-particle correlations in semiconductors. They are in excellent agreement with experimental data.

Secreted lipases of Candida albicans: cloning, characterisation and expression analysis of a new gene family with at least ten members

Extracellular lipolytic activity enabled the human pathogen Candida albicans to grow on lipids as the sole source of carbon. Nine new members of a lipase gene family (LIP2-LIP10) with high similarities to the recently cloned lipase gene LIP1 were cloned and characterised. The ORFs of all ten lipase genes are between 1281 and 1416 bp long and encode highly similar proteins with up to 80% identical amino acid sequences. Each deduced lipase sequence has conserved lipase motifs, four conserved cysteine residues, conserved putative N-glycosylation sites and similar hydrophobicity profiles. All LIP genes, except LIP7, also encode an N-terminal signal sequence. LIP3-LIP6 were expressed in all media and at all time points of growth tested as shown by Northern blot and RT-PCR analyses. LIP1, LIP3, LIP4, LIP5, LIP6 and LIP8 were expressed in medium with Tween 40 as a sole source of carbon. However, the same genes were also expressed in media without lipids. Two other genes, LIP2 and LIP9, were only expressed in media lacking lipids. Transcripts of most lipase genes were detected during the yeast-to-hyphal transition. Furthermore, LIP5, LIP6, LIP8 and LIP9 were found to be expressed during experimental infection of mice. These data indicate lipid-independent, highly flexible in vitro and in vivo expression of a large number of LIP genes, possibly reflecting broad lipolytic activity, which may contribute to the persistence and virulence of C. albicans in human tissue.

The N-terminal fragment of human parathyroid hormone receptor 1 constitutes a hormone binding domain and reveals a distinct disulfide pattern

The N-terminal extracellular parts of human G-protein coupled receptor class B, for example, receptors for secretin, glucagon, or parathyroid hormone, are involved in ligand binding. To obtain structural and functional information on the N-terminal receptor fragment of human parathyroid hormone receptor 1 (PTHR1), the truncated receptor was expressed in the cytosol of Escherichia coli in the form of inclusion bodies. Oxidative refolding of inclusion body material resulted in stable, soluble, monomeric protein. Ligand binding was proved by surface plasmon resonance spectroscopy and isothermal titration calorimetry. Refolded receptor fragment was able to bind parathyroid hormone with an apparent dissociation constant of 3-5 microM. Far-UV circular dichroism spectra showed that the refolded polypeptide contained approximately 25% alpha-helical and 23% beta-sheet secondary structures. Analysis of the disulfide bond pattern of the refolded receptor fragment revealed disulfide bonds between Cys170 and Cys131, Cys148 and Cys108, and Cys117 and Cys48. These results demonstrate that the extracellular N-terminal domain of the parathyroid hormone receptor (PTHR1) possesses a well-defined, stable conformation, which shows a significant ligand binding activity.

Repeated pressure-flow studies in the evaluation of bladder outlet obstruction due to benign prostatic enlargement. Finasteride Urodynamics Study Group

Test-retest reliability of repeated voids in pressure-flow studies and the influence on maximum flow rate (Q(max)pQ), detrusor pressure at maximum flow rate (p(det)Qmax), voided volume, and residual urine were studied. Also the agreement in interpretation of pressure-flow tracings between investigators and a single blinded central reader acting as a quality control center (QCC) were assessed. In addition, correlations between p(det)Qmax and patient age, International Prostate Symptom Score (IPSS), free maximum flow rate (Qmax), and prostate volume were calculated. Using suprapubic pressure recording, 216 men with lower urinary tract symptoms (LUTS) due to benign prostatic enlargement (BPE) were investigated in 11 centers. In each pressure-flow study, three sequential voids were performed, and quality controlled recordings were analyzed for Q(max)pQ and p(det)Qmax by the QCC. Trans rectal ultrasound was used to measure the prostate volume. Mean Q(max)pQ did not change, but p(det)Qmax decreased significantly in the second and third sequential voids. Using the Abrams-Griffiths nomogram definition of obstruction, 125 patients (67%) were classified as obstructed from the first void, but only 111 patients (59%) from the third void. The agreement between the investigator assessment and that of a single blinded reader was good. There was no significant correlation between p(det)Qmax and patient age, IPSS, and Qmax, whereas a modest correlation was found between p(det)Qmax and prostate volume. In summary, there was no significant change in Q(max)pQ, but p(det)Qmax decreased for the three consecutive voids, which can be explained by a decrease in outlet resistance. The agreement between the investigator and QCC interpretations shows the value of a standardized technique, supporting the feasibility of multicenter urodynamic studies. There is a modest, but statistically significant, correlation between detrusor pressure and prostate size, supporting the hypothesis that prostate size is a contributing factor in symptomatic BPH.

Relationships between lower urinary tract symptoms and bladder outlet obstruction: results from the ICS-"BPH" study

Despite the lack of evidence in the literature for close relationships between lower urinary tract symptoms and bladder outlet obstruction, the majority of urologists rely on symptomatology when selecting patients for prostatic surgery. We investigated the relationships between a wide range of lower urinary tract symptoms from the ICSmale questionnaire and the results of urodynamic pressure and flow studies. We evaluated 933 patients with lower urinary tract symptoms suggestive for bladder outlet obstruction from 12 countries who participated in the ICS-"BPH" study with the ICSmale questionnaire and urodynamic pressure and flow studies. Spearman rank correlation coefficients were obtained between symptoms and measures of bladder outlet obstruction. There was little or no correlation between a wide range of symptoms and the results of free uroflowmetry and pressure and flow studies. From symptoms alone, it is not possible to diagnose bladder outlet obstruction. Pressure and flow studies and symptom profiles measure different aspects of the clinical condition that should be viewed separately in the evaluation and treatment decision of the patient presenting with lower urinary tract symptoms.

Cloning and targeted disruption of two polygalacturonase genes in Penicillium olsonii

The filamentous fungus Penicillium olsonii secretes several polygalacturonases (PGs) with molecular masses of about 47 kDa. These enzymes consist of several basic and acidic isoforms, with dominant activities at pI 4.5 and pI 7.9. Two polygalacturonase genes, pg1 and pg2, have been cloned. The corresponding enzymes, PG1 and PG2, consist of 370 and 380 amino acids, respectively, and show significant similarities to endo-polygalacturonases from other filamentous fungi. Targeted disruption of pg1 resulted in the elimination of all basic PG isoforms. In contrast, disruption of pg2 reduced, but did not eliminate the acidic PG activities. The PGs of P. olsonii must therefore be encoded by a gene family of at least three genes. Induction studies with various carbon sources revealed that the acidic and basic isoforms are differentially regulated. Pectin is the best inducer of the acidic PG isoforms. The basic isoforms, however, are best induced by monosaccharides like glucose, alpha-L-rhamnose and alpha-L-arabinose.

Expression-level dependent activation of recombinant human parathyroid hormone/parathyroid hormone-related peptide receptor: effect of human parathyroid hormone (1-34), (1-31), and (28-48)

A stable recombinant chinese hamster ovary (CHO) cell model system expressing the human type-1 receptor for parathyroid hormone and parathyroid hormone-related peptide (hPTH-R) was established for the analysis of human PTH (hPTH) variants. The cell lines showed receptor expression in the range from 10(5) to I.9 x 10(6) receptors per cell. The affinity of the receptors for hPTH-(1-34) was independent of the receptor number per cell (Kd approximately = 8 nmol/1). The induction of cAMP by hPTH-(1-34) is maximal in clones expressing >2x10(5) receptors per cell and Ca++ signals were maximal in cell lines expressing >1.4x10(6) receptors per cell. Second messenger specific inhibitors demonstrated that PTH-induced increases in intracellular cAMP and Ca++ are independent and Ca++ ions are derived from intracellular stores. The cAMP-specific receptor activator hPTH-(1-31) showed also an increase in intracellular Ca++. Even in cell lines expressing more than 10(6) receptors per cell the Ca++/PKC specific activator hPTH-(28-48) did not activate hPTH-Rs. Based on these results, synthesis of further derivatives of PTH is required to identify pathway-specific ligands for the type-1 hPTH-R.

Induction of cyclooxygenase expression and enhancement of malignant cell transformation by 2,3,7,8-tetrachlorodibenzo-p-dioxin

The potential role of arachidonic acid metabolism in the enhancement (promotion) of malignant transformation of C3H/M2 mouse fibroblasts by the tumor promoter 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) was investigated using inhibitors of cyclooxygenase and lipoxygenase activities. The promoting effects of TCDD (1.5 pM) and of the reference tumor promoter 12-O-tetradecanoylphorbol-13-acetate (TPA; 0.4 mM) on carcinogen (N-methyl-N'-nitro-N-nitrosoguanidine or 3-methylcholanthrene)-pre-treated fibroblasts was abolished by cotreatment with indomethacin, hydrocortisone, caffeic acid or nordihydroguaiaretic acid. A differential inhibition was found with N-(2-cyclohexyloxy-4-nitrophenyl)methanesulfonamide, a selective inhibitor of the cyclooxygenase isoenzyme COX-2: the promoting effect of TPA, but not that of TCDD, was abolished. Therefore, the role of the cyclooxygenase isoenzymes COX-1 and COX-2 during chronic exposure to TCDD was studied in more detail. Long-term treatment with TCDD (4-7 weeks) induced the expression of COX-1 and COX-2 mRNA in C3H/M2 fibroblasts (up to 2-fold). The enhanced expression of COX-2 protein in TCDD-treated fibroblasts was confirmed by western blot analysis. Concomitantly, the accumulation of the prostaglandins (PGs) PGE(2) and 6-keto-PGF(1alpha), which were identified as major metabolites of arachidonic acid in C3H/M2 cell cultures, was enhanced ( approximately 2-fold) following long-term treatment with TCDD (0.15 and 1.5 pM). The results suggest that the stimulation of arachidonic acid metabolism caused by a sustained cyclooxygenase induction is a critical event in the promoting action of TCDD in mouse fibroblasts in vitro. However, in contrast to TPA, the TCDD-mediated enhancement of malignant cell transformation may not specifically depend on the induction of COX-2 but, additionally, the induction of COX-1 activity may be necessary.

Secreted aspartic proteinase (Sap) activity contributes to tissue damage in a model of human oral candidosis

Secreted aspartic proteinases (Saps) are important virulence factors during Candida albicans mucosal or disseminated infections. A differential expression of individual SAP genes has been shown previously in a model of oral candidosis based on reconstituted human epithelium (RHE), and in the oral cavity of patients. In this study, the ultrastructural localization of distinct groups of Sap isoenzymes expressed during RHE infection was shown by immunoelectron microscopy using specific polyclonal antibodies directed against the gene products of SAP1-3 and SAP4-6. Large amounts of Sap1-3 antigen were found within C. albicans yeast and hyphal cell walls, often predominantly in close contact with epithelial cells, whereas lower quantities of Sap4-6 were detected in hyphal cells. To elucidate the relevance of the expressed Saps during oral infections, we examined the effect of the aspartic proteinase inhibitor, pepstatin A, during infection of the RHE. The extent of lesions caused by the strain SC5314 was found to be strongly reduced by the inhibitor, indicating that proteinase activity contributes to tissue damage in this model. To clarify which of the SAP genes are important for tissue necrosis, the histology of RHE infection with Deltasap1, Deltasap2, Deltasap3, Deltasap4-6 and three Deltasap1/3 double mutants were examined. Although tissue damage was not blocked completely with these mutants, an attenuated phenotype was observed for each of the single sap null mutants, and was more strongly attenuated in the Deltasap1/3 double null mutants. In contrast, the lesions caused by the Deltasap4-6 triple mutant were at least as severe as those caused by SC5314. During infection with the mutants, we observed that the SAP gene expression pattern of the Deltasap1 and the Deltasap1/3 mutants was altered in comparison with the wild-type strain. Expression of SAP5 was observed only during infection with the Deltasap1/3 mutant, whereas upregulation of SAP2 and SAP8 transcripts was observed in the Deltasap1 and the Deltasap1/3 mutants. These results suggest that Sap1-3, but not Sap4-6, contribute to tissue damage in this model. Furthermore, C. albicans may compensate for the deletion of certain SAP genes by upregulation of alternative SAP genes.

Nosocomial infections after transurethral prostatectomy

In spite of new techniques transurethral prostatic resection (TURP) remains the gold standard in operative therapy of benign prostatic hyperplasia. There are some suggested risk factors for TURP which could affect the rate of postoperative complications. In this prospective study we investigated whether the suggested risk factors have any relevance for the occurrence of nosocomial urinary tract infections (UTIs) after TURP and what kind of influence these infections may have on the clinical course. In general we found no statistically significant influence on the analyzed risk factors for the incidence of nosocomial UTIs. On the other hand in the group of patients with nosocomial UTIs both the rate of other nosocomial infections (i.e. septicemia) and the rate of inflammatory complications were significantly higher compared to the group without postoperative UTIs (p < 0.001). We conclude that all patients undergoing TURP should receive perioperative antimicrobial prophylaxis.

Continued improvement in pressure-flow parameters in men receiving finasteride for 2 years. Finasteride Urodynamics Study Group

OBJECTIVES

To assess the long-term effects of finasteride on pressure-flow parameters in men with urodynamically documented bladder outflow obstruction (BOO).

METHODS

One hundred twenty-one men with benign prostatic enlargement (BPE) and lower urinary tract symptoms (LUTS) underwent a pressure-flow study (PFS) at 1 of 11 clinical centers. The PFS technique was standardized, and all tracings were read by a single reader unaware of the treatment group. Patients who were obstructed according to a modified Abrams-Griffiths nomogram were randomized to 5 mg finasteride (n = 81) or placebo (n = 40) for 12 months; all patients continuing into an open extension received finasteride during the second 12 months of therapy. Results of the initial 12-month study demonstrated the benefit of finasteride treatment on PFS parameters. To examine the continuing effects over time, an analysis of the data from 54 patients who completed 24 months of treatment with finasteride is provided.

RESULTS

Detrusor pressure at maximum flow (PdetQmax) continued to decrease during the second 12 months of therapy (decreases of 5.3 and 11.7 cm H2O at months 12 and 24, respectively). The percentage of patients obstructed by Abrams-Griffiths classification decreased from 76.2% at baseline to 66.7% at month 12 and 59.6% at month 24. An intention-to-treat analysis yielded similar results.

CONCLUSIONS

Finasteride improves urodynamic measures of obstruction in men with BPE and LUTS, with continued improvement during the second 12 months of therapy.

Mutagenesis via insertional- or restriction enzyme-mediated-integration (REMI) as a tool to tag pathogenicity related genes in plant pathogenic fungi

Random insertional mutagenesis is a powerful tool to investigate the molecular basis of most genetically determined processes, for example in pathogenic fungi. An improved version of this method is the insertional mutagenesis via restriction enzyme mediated integration (REMI). Transformation efficiency and mode of vector integration are species dependent and further influenced by vector conformation, restriction enzyme activity, and transformation protocol. An overview is given, covering the mutants and already identified genes obtained after REMI mutagenesis. An outlook describes the future developments in the field.