Effect of short-term scrotal hyperthermia on spermatological parameters, testicular blood flow and gonadal tissue in dogs

The objective was to assess the effect of a short-term scrotal hyperthermia in dogs on quantitative and qualitative ejaculate parameters, testicular blood flow and testicular and epididymal histology. After a control period, the scrotum of seven normospermic adult beagle dogs was insulated with a self-made suspensory for 48 h. Nine weeks later, two animals were castrated, while in five animals, scrotal hyperthermia was repeated. Dogs were castrated either 10 or 40 days thereafter. In each phase of scrotal insulation, average scrotal surface temperature increased by 3.0°C. Semen was collected twice weekly throughout the experiment. Total sperm count did not change after the first hyperthermia, but it slightly decreased after the second (p < 0.05). Profiles of sperm morphology and velocity parameters (CASA) rather indicated subtle physiological variations in sperm quality than effects of a local heat stress. Chromatin stability of ejaculated spermatozoa as indicated by SCSA remained constant throughout the experiment. Perfusion characteristics of the gonads, that is, systolic peak velocity, pulsatility and resistance index at the marginal location of the testicular artery, did not change due to hyperthermia (p > 0.05). Histological examination of excised testes and epididymides for apoptotic (TUNEL and activated caspase-3) and proliferating cells (Ki-67 antigen) indicated only marginal effects of scrotal insulation on tissue morphology. In conclusion, a mild short-term scrotal hyperthermia in dogs does not cause substantial changes in sperm quantity and quality. In contrast to other species, canine testes and epididymides may have a higher competence to compensate such thermal stress.

Analyzing effects of photodynamic therapy with 5-aminolevulinic acid (ALA) induced protoporphyrin IX (PPIX) in urothelial cells using reverse phase protein arrays

Photodynamic therapy (PDT) using 5-aminolevulinic acid (ALA)-induced protoporphyrin IX (PPIX) is clinically established approach for a number of defined applications. However, in order to optimize the therapeutic benefits of PDT, the specific mode of cell destruction should be better defined. Apoptosis is favored over necrosis for clinical practice as the latter causes more side-effects. In the present study, we analyse PDT-induced cell death and its correlation to various PDT parameters (different doses applied, time after PDT treatment) in vitro using reverse phase protein arrays. Human urothelial cell lines with varying degrees of differentiation (UROtsa, RT4, RT112, J82) were subjected to in vitro-PDT using increasing doses of irradiation. In addition, positive controls for apoptosis, necrosis and un-/specific cellular damage were included. Cells were harvested over a specified time course, lysed and arrayed onto nitrocellulose-covered glass slides. The arrays were analyzed for expression of apoptosis-related proteins by immunohistochemistry. Analysis of caspase-3 and -9 expression, the activation of HIF-1alpha, Bcl2, Cox2 and the phosphorylation of AKT reveals signal activation due to a PDT-stimulus in correlation with the positive controls. Data were analyzed by unsupervised hierarchical clustering and depicted as a heat map revealing cell-specific patterns of pathway stimulation. Higher differentiated phenotypes showed a more distinct signal response in general and a higher apoptotic response in detail. Lower differentiated cell lines lost pathway regulation capabilities according to their state of dedifferentiation. Reverse phase protein arrays are a promising technique for signal pathway profiling: they exceed the range of traditional western blots by sensitivity, high-throughput capability, minimal sample consumption and easy quantification of results obtained.

Artificial intelligence and bladder cancer arrays

Non-muscle invasive bladder cancer is a heterogenous disease whose management is dependent upon the risk of progression to muscle invasion. Although the recurrence rate is high, the majority of tumors are indolent and can be managed by endoscopic means alone. The prognosis of muscle invasion is poor and radical treatment is required if cure is to be obtained. Progression risk in non-invasive tumors is hard to determine at tumor diagnosis using current clinicopathological means. To improve the accuracy of progression prediction various biomarkers have been evaluated. To discover novel biomarkers several authors have used gene expression microarrays. Various statistical methods have been described to interpret array data, but to date no biomarkers have entered clinical practice. Here, we describe a new method of microarray analysis using neurofuzzy modeling (NFM), a form of artificial intelligence, and integrate it with artificial neural networks (ANN) to investigate non-muscle invasive bladder cancer array data (n=66 tumors). We develop a predictive panel of 11 genes, from 2800 expressed genes, that can significantly identify tumor progression (average Logrank p = 0.0288) in the analyzed cancers. In comparison, this panel appears superior to those genes chosen using traditional analyses (average Logrank p = 0.3455) and tumor grade (Logrank, p = 0.2475) in this non-muscle invasive cohort. We then analyze panel members in a new non-muscle invasive bladder cancer cohort (n=199) using immunohistochemistry with six commercially available antibodies. The combination of 6 genes (LIG3, TNFRSF6, KRT18, ICAM1, DSG2 and BRCA2) significantly stratifies tumor progression (Logrank p = 0.0096) in the new cohort. We discuss the benefits of the transparent NFM approach with respect to other reported methods.

[Prognostic and predictive impact of protein expression profiling in high risk breast cancer patients treated with high-dose chemotherapy]

The prognostic and predictive impact of protein expression profiles was analyzed in high-risk breast cancer patients who had previously been shown to benefit from high-dose chemotherapy (HDCT) in comparison to dose-dense chemotherapy (DDCT). Using tissue microarrays, the expression of 34 protein markers was evaluated in 236 patients who had received either HDCT or DDCT (in the WSG AM01 trial). 1) 24 protein markers of the initial panel of 34 markers were sufficient to identify five profile clusters by K-means clustering: luminal A (27%), luminal B (12%), HER-2 (21%), basal-like (13%) cluster and a so called 'multiple marker negative'=MMN cluster (27%) characterized by the absence of specifying markers. 2) After DDCT, HER-2 and basal-like groups had significantly worse event-free survival (EFS) (HR 3.6 (95% CI, 1.65-8.18; p = 0.001) and HR 3.7 (95% CI, 1.68-8.48); p < 0.0001), respectively) when compared to both luminal groups. 3) After HDCT, the hazard ratio was 1.5 (95% CI, 0.76-3.05) for EFS in the HER-2 subgroups and 1.1 (95% CI, 0.37-3.32) in the basal-like subgroups which indicates a better outcome for patients in the HER-2 and basal-like subgroups who received HDCT. Protein expression profiling in high-risk breast cancers identified 5 subtypes, which differed with respect to survival and response to chemotherapy: In contrast to luminal A and B subtypes, HER-2 and basal-like subgroups had a significant predictive benefit from HDCT when compared to DDCT.

Assessment of uncertainty in Great Barrier Reef catchment models

This paper addresses uncertainty in socio-economic and sediment-nutrient models that are being developed for the assessment of change in the Great Barrier Reef (GBR) area. The catchments draining into the GBR lagoon are sources of pollutants. The Reef Water Quality Management Plan of the Queensland Government identified sediments and nutrients transported to the GBR lagoon as the major long-term threats to the reef and inshore ecosystems and the wellbeing of the human communities. The plan clearly indicates that changes in land management are required by 2013 to reduce pollutant inputs and, at the same time, maintain or enhance the benefits from using the inland waters. Science that provides decision tools for natural resource management and improves socio-economic and biophysical understanding is required to enable managers to make better decisions. A major research activity (the Water for a Healthy Country Flagship) aims to address social, economic and biophysical outcomes of land management change in the GBR. It contains research activities that provide information for integrated model development. Currently, however, these models lack the ability to estimate the uncertainty associated with prediction. This project aims to provide statistical methods for assessing uncertainty in models of sediment transportation to the GBR. Furthermore, it provides a link between the models and the decision-making process that allows assessment of uncertainty, a step pertinent to the risk analysis of policy options. This paper describes current and ongoing approaches for assessing uncertainty using a sediment modelling example and provides a way forward for the integration of applied socio-economic and biophysical models used in the decision-making process.

Retrospective analysis of WSG AM01 tandem high dose chemotherapy trial in high risk primary breast cancer: A hypothesis generating study

665

Background: The WSG AM 01 trial is the first one to report superiority of HDC in terms of DFS and OS in patients with >9 positive axillary lymph nodes. Retrospectively we tried to identify patient subgroups with maximum benefit from HDC. Methods: 403 patients were randomized to tandem HDC or to dose-dense conventional chemotherapy (DD). 236 tumors were available for central pathologic review (117/119). A panel of 34 markers were determined by IHC in TMA. Kaplan-Meier, Log rank and Cox proportional hazard models were used for uni- and multivariate analysis. We choose K-means clustering with K=5 and using Manhattan distance as similarity measure. Results: Pts: n=236 (HDC/DD): mean age 47.3/47.4 yrs, mean tumor sizes 3.5/3.4cm, mean positive lymph nodes 17.2/17.0, HR+ 55%/53%, G3 44%/35%. HDC was superior to DD (p=0.02). Multivariate analysis demonstrated a significant correlation for grading, tumor size, PR+. HR > 2 were reported for the following markers: Her2neu+, p53+, bcl2−, Ck 5/6 and 17+, Ck8−, c-kit+, vimentin+, ETR 1/2, BCRP+. Triple negative tumors (TN) (31%) had a large benefit from HDC (HR DD vs. HD: 3.06, 95%CI:1.41–6.06). Groups identified by K-means clustering could be attributed to luminal-A-(31%), luminal-B-(27%), her2-(11%), basal like-(11%) type and a so far undefined proliferative group (20%) characterized mainly by the absence of specifying markers. Interestingly, the proportion of the above mentioned molecular subtypes within of high risk populations very similar to those reported for less selected populations. Her2, basal-like and the undefined proliferative group had significantly worse outcome when compared to luminal tumors (p<0.01). Very poor prognosis if treated by conventional CT was observed in basal like (HR DD vs HD=2.66 95%CI: 0.9–7.9) und the undefined group (HR=1,72, 95%CI:0.92–3.21), where most of the TN tumors were found. Conclusions: Tandem HDC is superior to DD conventional CT for treatment of HRBC. The largest benefit from high dose chemotherapy was reported for younger patients with TN poor differentiated tumors, >2cm. Negative hormone receptor status, p53+, bcl2−, MIB/p16+ and BCRP+ predicted benefit from dose intensification. Subgroups are small and may help to generate further hypothesises.

No significant financial relationships to disclose.

Biological characteristics in triple negative high risk breast cancer and their clinical implications

20032

Background: Hormone receptor and Her2neu negative breast cancer (triple negative, TN) presents an aggressive biological subtype with decreased survival. Basal-like BC identified by gene expression arrays (Perou CM, et al. Nature 2000) may be associated with TN breast cancer. Several studies defined the origin of TN or BBC breast cancer in a progenitor epithelial cell that is undifferentiated. Other studies investigated the association of TN with EGFR expression or BRCA1 mutations. The aim of our study was to analyze the expression of stem cell or basal markers in TN high risk breast cancer. Methods: We examined 236 patients from central tumour bank from high risk breast cancer patients (>9 positive LN), who were randomized to the WSG AM-01 trial (phase III tandem HDC versus DD CT). The following markers were profiled by IHC in TMA for all patients: ER, PR, Her2neu, MIB-1, EGFR, p53, Ck 5/6, CK17, c-kit, p63, Vimentin, ABCA3, and BCRP. Their correlation with survival was studied. Results: 65 patients (30%) of 218 patients assessable for hormone receptor and Her2neu staining, were identified as TN, surprisingly not indicating any higher incidence of TN tumors in this selected high risk collective, when compared to other more heterogeneous populations. This phenotype was significantly more frequent in premenopausal women, and was significantly associated with G3, MIB1 and EGFR, CK5/6 and 17, c-kit, vimentin, p53 and BCRP expression. No association with p63 and ABCA3 was found. Poor grading, MIB1+, CK5/6 and 17, c-kit, vimentin and BCRP+ strongly correlated with relapse. Patients with TN tumors had significantly worse overall survival (p = 0.002) in comparison to the remaining group. Conclusions: The triple negative BC-type is frequent in patients with multiple positive lymph nodes and has a poor prognosis. Its association with age and basal and progenitor cell molecular markers suggests correlation with BRCA1 mutations as a potential marker for resistance to alkylating agents (Sorlie, PNAS 2003). Modern experimental (chemo)-therapy designs in this subgroup should take into account the higher incidence of EGFR and basal stem cell marker expression, p53 mutations, the poor differentiation, the expression of chemoresistance markers and the high proliferative activity.

No significant financial relationships to disclose.

C-kit expression in high-risk breast cancer subgroup treated with high-dose or conventional dose-dense chemotherapy

The proto-oncogene c-kit is known to be expressed in poorly differentiated breast cancer. In this study, we retrospectively evaluated the prognostic and predictive impact of c-kit in a high risk subgroup of breast cancer patients (>9 axillary node metastases) who received high-dose (HDCT) or dose-dense (DDCT) conventional chemotherapy and correlated these findings with the expression of the basal-type markers CK5 and CK 17, estrogen (ER) and progesterone (PR) receptor, Her-2/neu and MIB 1. C-kit, CK5, CK17, ER, PR, Her-2/neu and MIBI expression was evaluated immunohistochemically using tissue microarrays containing breast cancer samples from 236 patients who were randomized to the WSG AM01 trial (median follow-up of 60 months). There was a significant overall survival (OS) benefit for patients receiving HDCT compared to DDCT (p = 0.027). C-KIT expression was found in 12 % of all breast cancers and correlated with a poorer OS in multivariate analysis (p = 0.051). Furthermore, c-kit correlated with high grade (p = 0.019), CK5- and CK17-positivity (p <0.0001 and p = 0.001, respectively) and ER- and PR-negativity (p = 0.04 and p = 0.008, respectively). In contrast to CK5 and CK17, patients with c-kit positive breast cancers revealed no benefit from high-dose chemotherapy. These findings underline that c-kit expression represents an independent negative prognostic marker in high-risk breast cancer. Correlation with CK5 +/CK17+ and ER-/PR-suggests that c-kit positive carcinomas are at least partly of basal-type.

Prolonged Stability of Stored Vancomycin, Gentamicin, and Heparin for Use in the Antibiotic-Lock Technique

The antibiotic-lock technique has been effective in salvaging tunneled catheters in hemodialysis patients with bacteremia. However, a practical concern exists with respect to the stability of the antibiotics and heparin in normal saline, when stored for a prolonged period. Vancomycin, gentamicin, and heparin were diluted in normal saline to a final concentration of 100 microg/ml of each antibiotic and 5000 units/ml heparin. Fresh samples, and samples refrigerated at 4 degrees C for 48 hours, 1 week, 2 weeks, 3 weeks, and 4 weeks, were assayed (in triplicate) for gentamicin and vancomycin concentration and bactericidal activity (Schlichter test) using methicillin-resistant Staphylococcus aureus and Pseudomonas aeruginosa. An anti-Xa activity assay was used for monitoring heparin anticoagulant activity of the fresh samples and samples refrigerated for 2 and 4 weeks. Mean (+/- SD) anti-Xa activity for heparin/vancomycin solution was 7900 +/- 173 u/ml, and for heparin/gentamicin solution was 7467 +/- 751u/ml; both were stable over a 4-week storage period. Mean bactericidal titer for vancomycin was 1:121 +/- 11, and for gentamicin was 1:242 +/- 22; both were stable over a 4-week storage period. Mean vancomycin concentration was 97 +/- 4 microg/ml, and gentamicin concentration was 86 +/- 3 microg/ml; both were stable over a 4-week storage period. Vancomycin and gentamicin in a heparin/saline solution can be stored at 4 degrees C for up to 4 weeks without adversely affecting antibiotic concentration, bactericidal activity, or heparin anticoagulant activity.

A multi-criteria approach to Great Barrier Reef catchment (Queensland, Australia) diffuse-source pollution problem

This paper presents a multi-criteria based tool for assessing the relative impact of diffuse-source pollution to the Great Barrier Reef (GBR) from the river basins draining into the GBR lagoon. The assessment integrates biophysical and ecological data of water quality and pollutant concentrations with socio-economic information pertaining to non-point source pollution and (potential) pollutant impact. The tool generates scores for each river basin against four criteria, thus profiling the basins and enabling prioritization of management alternatives between and within basins. The results support policy development for pollution control through community participation, scientific data integration and expert knowledge contributed by people from across the catchment. The results specifically provided support for the Reef Water Quality Protection Plan, released in October 2003. The aim of the plan is to provide a framework for reducing discharge of sediment, nutrient and other diffuse-source loads and (potential) impact of that discharge and for prioritising management actions both between and within river basins.

Capgras syndrome--out of sight, out of mind?

OBJECTIVE

Recent theoretical approaches emphasize a disorder of face processing in the pathogenesis of the Capgras syndrome. We report a patient with the Capgras syndrome developing in the physical absence of the person who is believed to be replaced and thus a limited role for a disorder of face processing.

METHOD

The clinical phenomenology of a case of the Capgras syndrome is explored.

RESULTS

A disorder of face processing might not be a sufficient explanation of the course of the disorder in this patient.

CONCLUSION

Face processing accounts, of the Capgras delusion, have to be supplemented by additional assumptions.

[A thirty-year old bodybuilder with septic shock and ARDS from abuse of anabolic steroids]

Wir berichten über einen 30-jährigen Bodybuilder, der auf dem Boden regelmäßiger intramuskulärer Selbstinjektionen anabol-androgener Steroide einen glutealen Spritzenabszess ausbildete. Nach Abszessspaltung in Allgemeinanästhesie entwickelte er einen septischen Schock und ein fulminantes “acute respiratory distress syndrome” (ARDS). Anhand der Kasuistik sollen neben Aspekten zur Pathogenese, Differenzialdiag-nose und Therapie insbesondere mögliche immunmodulatorische Mechanismen anaboler Substanzen diskutiert werden, die in diesem Fall den Krankheitsverlauf beeinflusst haben könnten.

Clinical phase II study and pharmacological evaluation of rubitecan in non-pretreated patients with metastatic colorectal cancer-significant effect of food intake on the bioavailability of the oral camptothecin analogue

A randomised, open label phase II study was performed in patients with advanced colorectal cancer to evaluate the safety, toxicity and antineoplastic activity of the topoisomerase I-inhibitor rubitecan. A cross-over design was chosen to determine the intrapatient variation of the bioavailability and pharmacokinetics of the anticancer agent depending on the timing of food intake in relation to the oral drug administration. Patients with previously untreated metastatic disease received two single oral doses of rubitecan 1.5 mg/m2 for assessment of the pharmacokinetics. They were randomised to have the first administration either after an overnight fasting period or immediately after a high calorie breakfast, and crossed over to the alternative schedule after a one-week washout period. After completion of the pharmacokinetic sampling, treatment continued with rubitecan given orally at a dose of 1.5 mg/m2/day, to be increased up to 2.0 mg/m2/day, under fasting conditions for 5 consecutive days per week until disease progression. 19 patients entered the trial after informed consent was obtained. A total number of 35 treatment cycles (median 2, range 1-4) were administered. All patients were evaluable for safety. The toxicity profile of rubitecan was generally mild to moderate, with sporadic cases of grade 4 toxicities (Common Toxicity Criteria (CTC) version 2.0) diarrhoea, leucopenia and neutropenia. None of 15 evaluable patients achieved an objective response. The majority had early disease progression. 14 patients were evaluable for pharmacokinetic analysis. The bioavailability of rubitecan was found to be strongly dependent on the timing of food intake with a fasted-to-fed ratio for C(max) of 1.98 (two-tailed P<0.001; ANOVA), T(max) 0.49 (P<0.001), AUC(0-8 h) 2.52 (P<0.001) and AUC(0-24 h) 1.64 (P=0.003). Rubitecan is well tolerated, but clinically inactive in colorectal cancer at the currently recommended dose and schedule. The bioavailability is strongly dependent on the timing of food intake in relation to the oral administration of the drug. The topoisomerase I-inhibitor should be administered under fasting conditions to achieve adequate drug exposure in future prospective trials in other tumour types.

The Drosophila Geminin homolog: roles for Geminin in limiting DNA replication, in anaphase and in neurogenesis

We have identified a Drosophila homolog of the DNA replication initiation inhibitor Geminin (Dm geminin) and show that it has all of the properties of Xenopus and human Geminin. During Drosophila development, Dm Geminin is present in cycling cells; protein accumulates during S phase and is degraded at the metaphase to anaphase transition. Overexpression of Dm geminin in embryos inhibits DNA replication, but cells enter mitosis arresting in metaphase, as in dup (cdt1) mutants, and undergo apoptosis. Overexpression of Dm Geminin also induces ectopic neural differentiation. Dm geminin mutant embryos exhibit anaphase defects at cycle 16 and increased numbers of S phase cells later in embryogenesis. In a partially female-sterile Dm geminin mutant, excessive DNA amplification in the ovarian follicle cells is observed. Our data suggest roles for Dm Geminin in limiting DNA replication, in anaphase and in neural differentiation.

Etomidate and thiopental inhibit platelet function in patients undergoing infrainguinal vascular surgery

BACKGROUND

Postoperative platelet hyperaggregability following general anesthesia has been reported in patients undergoing major vascular surgery. In contrast, since anesthetic agents inhibited platelet function both in vitro and in vivo, an increased risk for postoperative bleedings due to prolonged platelet dysfunction has been discussed. Nevertheless, data describing platelet-affecting properties of induction agents such as etomidate and thiopental in patients undergoing major vascular surgery are lacking.

METHODS

Platelet function was determined at 0, 2, 20, and 200 microg/ml thiopental and at 0, 0.2, 2, 20 microg/ml etomidate in vitro in blood samples drawn from 16 patients suffering from severe occlusive arterial disease. In addition, 30 patients undergoing vascular surgery were investigated before (PRE) and after anesthesia induction (T0) either with etomidate (ETO group, n=16) or thiopental (THIO group, n=14), and 2 h after the beginning of surgery (T2). Platelet function was determined according to platelet aggregation, in vitro bleeding time, and flow cytometric measurements.

RESULTS

In vitro, P-selectin expression was inhibited by etomidate at 2 and 20 microg/ml (-28% and -38%, respectively) and also by thiopental at 200 microg/ml (-27%). In patients undergoing vascular surgery, anesthesia induction in the ETO group resulted in a 31% prolongation of the in vitro bleeding time and an inhibition of ADP- and collagen-induced platelet aggregation (-30% and -17%, respectively) and of P-selectin expression (-25%) at T0. In the THIO group, only ADP-induced platelet aggregation was affected (-16%). At T2, all parameters had reached PRE level again in both groups. Furthermore, in comparison with the THIO group, operation time was significantly prolonged and transfusion volume was significantly increased in the ETO group. In addition, platelet count and hematocrit significantly decreased at T2, whereas levels of tPA, PAI-1, fibrinogen and antithrombin III and partial thromboplastin time remained unchanged in both groups during the study period.

CONCLUSIONS

In the present study, etomidate and, to a minor extent, thiopental offered significant platelet inhibitory properties. Anesthetic-induced platelet inhibition may lead to higher transfusion rates and prolonged operation times. Therefore, anesthetic-related platelet inhibitory properties should be considered when searching for the anesthetic agent of choice, especially in patients with compromised hemostasis and co-existing bleeding disorders.

Disruption of the helix-u-turn-helix motif of MutS protein: loss of subunit dimerization, mismatch binding and ATP hydrolysis

The DNA mismatch repair protein, MutS, is a dimeric protein that recognizes mismatched bases and has an intrinsic ATPase activity. Here, a series of Taq MutS proteins having C-terminal truncations in the vicinity of a highly conserved helix-u-turn-helix (HuH) motif are assessed for subunit oligomerization, ATPase activity and DNA mismatch binding. Those proteins containing an intact HuH region are dimers; those without the HuH region are predominantly monomers in solution. Steady-state kinetics of truncated but dimeric MutS proteins reveals only modest decreases in their ATPase activity compared to full-length protein. In contrast, disruption of the HuH region results in a greatly attenuated ATPase activity. In addition, only dimeric MutS proteins are proficient for mismatch binding. Finally, an analysis of the mismatch repair competency of truncated Escherichia coli MutS proteins in a rifampicin mutator assay confirms that the HuH region is critical for in vivo function. These findings indicate that dimerization is critical for both the ATPase and DNA mismatch binding activities of MutS, and corroborate several key features of the MutS structure recently deduced from X-ray crystallographic studies.

A screen for modifiers of cyclin E function in Drosophila melanogaster identifies Cdk2 mutations, revealing the insignificance of putative phosphorylation sites in Cdk2

In higher eukaryotes, cyclin E is thought to control the progression from G1 into S phase of the cell cycle by associating as a regulatory subunit with cdk2. To identify genes interacting with cyclin E, we have screened in Drosophila melanogaster for mutations that act as dominant modifiers of an eye phenotype caused by a Sevenless-CycE transgene that directs ectopic Cyclin E expression in postmitotic cells of eye imaginal disc and causes a rough eye phenotype in adult flies. The majority of the EMS-induced mutations that we have identified fall into four complementation groups corresponding to the genes split ends, dacapo, dE2F1, and Cdk2(Cdc2c). The Cdk2 mutations in combination with mutant Cdk2 transgenes have allowed us to address the regulatory significance of potential phosphorylation sites in Cdk2 (Thr 18 and Tyr 19). The corresponding sites in the closely related Cdk1 (Thr 14 and Tyr 15) are of crucial importance for regulation of the G2/M transition by myt1 and wee1 kinases and cdc25 phosphatases. In contrast, our results demonstrate that the equivalent sites in Cdk2 play no essential role.

Randomized, placebo-controlled, blinded and cross-matched study on the antiplatelet effect of inhaled nitric oxide in healthy volunteers

The platelet inhibitory effect of 0-40 ppm inhaled nitric oxide (NO) was investigated in healthy men and women. In both groups, ADP-and collagen-induced platelet aggregation was significantly inhibited 20 (T20) and 40 min (T40) after the beginning of inhalation of 5, 10, and 40 ppm. Moreover, in both men and women, the in vitro bleeding time was significantly prolonged at T20 and T40 during inhalation of 40 ppm. Inhalation of NO also inhibited P-selectin expression at 5, 10, and 40 ppm and fibrinogen binding to the GPIIb/IIIa-receptor at 40 ppm. In conclusion, in healthy volunteers, the platelet inhibitory effect of inhaled NO was not dose-related, since it was significant at 5 and 10 ppm but did not increase during the administration of higher NO concentrations. In addition, gender-related differences were only observed in ADP-induced platelet aggregation at 10 ppm and in bleeding time prolongation at 40 ppm.

Management of failing prosthetic bypass grafts with metallic stent placement

PURPOSE

To evaluate the role of metallic stents in treating stenoses involving prosthetic arterial bypass grafts.

METHODS

Patients undergoing stent placement within a failing prosthetic bypass graft, during a 41-month period, were reviewed for treatment outcome and complications. The indications for stent placement in 15 patients included severe claudication (n = 3), rest pain (n = 9), and minor or major tissue loss (n = 3). Lesions were at the proximal anastomosis (n = 6), the distal anastomosis (n = 3), or within the graft (n = 6).

RESULTS

Treatment with metallic stents was successful in all patients. There was one acute stent thrombosis, successfully treated with thrombolytic therapy. Follow-up data are available for a mean duration of 12.3 months. The mean duration of primary patency was 9.4 months with 6- and 12-month primary patency rates of 51.9% and 37.0%, respectively. The mean duration of secondary patency was 12.1 months with 6- and 12-month secondary patency rates of 80.0% and 72.7%, respectively. Two patients with discontinuous runoff and preexisting gangrene required a below-knee amputation. Six patients were revised surgically after stent placement (at a mean of 10.8 months). Three late deaths occurred during follow-up.

CONCLUSION

Given the mortality risks of surgical revision and the reduced life expectancy of this patient population, metallic stent placement represents a viable, short-term treatment option for stenoses within or at the anastomoses of prosthetic grafts. Further evaluation is warranted to compare intragraft stent placement with surgical graft revision.