The influence of pharmaceutical compounds on male fertility

1. Steroid hormones can affect spermatogenesis and thereby fertility directly and/or indirectly. All antigonadotropically active steroids inhibit spermatogenesis via inhibition of gonadotropin secretion, mainly that of H. Androgens and steroids occurring in the biosynthetic chain of testosterone synthesis have a direct promoting effect on spermatogenesis if applied in high doses. It has not been possible as yet to make clinical use of this positive effect since it is obviously not possible to achieve the necessary intratesticular androgen concentrations. 2. As concerns the different androgens and the steroids in the androgen biosynthetic chain, and also all synthetic anabolics, there is no parallelism between the direct spermatogenic activity, the androgenic activity and the antigonadotropic activity. 3. Estrogens and synthetic gestagens do not inhibit spermatogenesis directly at the testicular level. All effects of estrogens can be abolished experimentally by adequate substitution with gonadotropins or androgens, or a combination of androgens and gonadotropins. 4. Only those antiandrogens inhibit spermatogenesis with additional antigonadotropic properties (e.g. cyproterone acetate). Pure antiandrogens, like flutamide or cyproterone, have a slight and transient influence on spermatogenesis at the most. If at all, they merely cause transient subfertility. 5. Beside steroids and several centrally active pharmaceutics (e.g. psychotropic drugs and several antihypertensive compounds), only siloxanes and methallibur seem to affect spermatogenesis via inhibition of gonadotropin secretion. Other antispermatogenic agents act by inhibition of mitosis (Colchicine, alkylating agents) or presumably via damage of the Sertoli cells. 6. Based on present knowledge, contraception in men could be principally managed by administration of a) androgens alone, b) gestagen/androgen combinations, c) estrogen/androgen combinations, d) certain antiandrogens. 7. The difficulties of contraception in men by steroid hormones or steroid hormone combinations have been pointed out. As regards the usefulness of antiandrogens for contraception, no definite conclusions can be drawn at the moment. All non-steroidal inhibitors of spermatogenesis which have been found up to the present are not suitable because of toxic effects.

Early detection of premalignant conditions in the colon by fluorescence endoscopy using local sensitization with hexaminolevulinate

BACKGROUND AND STUDY AIMS

We aimed to determine the feasibility of obtaining selective fluorescence of precancerous/cancerous lesions in the colon with a new fluorescence video endoscope system in combination with the selective photosensitizer precursor hexaminolevulinate (HAL), and to carry out a dose-finding study with evaluation of the optimal dose and application time.

PATIENTS AND METHODS

12 patients with colorectal lesions underwent sensitization with locally applied HAL enemas in two concentrations (0.8 mmol and 1.6 mmol). The examination was conducted either 30 or 60 minutes after rectal administration of the sensitizer, using a special light source capable of delivering either white or blue excitation light. Red fluorescence induced by illumination with blue light was detected via a prototype fluorescence video colonoscope. Biopsies were taken from suspicious areas found with white or blue light. Corresponding endoscopic, fluorescence, and microscopic findings were compared.

RESULTS

Using histological findings as the gold standard, 52/53 of the premalignant/malignant lesions showed red fluorescence under the photodynamic diagnosis (PDD) examination; 38/53 were detected with white-light endoscopy. The PDD mode showed 28 % more polyps than did white-light endoscopic imaging. The greatest fluorescence intensity in precancerous lesions was found with retention for 60 minutes of 500 ml of 1.6 mmol HAL.

CONCLUSIONS

Administration of HAL enema induces selective lesion fluorescence and increases the lesion detection rate in patients with colorectal adenoma and early carcinoma.

Donor myocardial HIF-1alpha is an independent predictor of cardiac allograft dysfunction: a 7-year prospective, exploratory study

Knowledge on interplay between the cardiac molecular response to transplantation-induced stress and primary graft dysfunction (PGD) is limited. A cDNA array identified HIF-1, EGR-1, NAB-2, VEGF-A and uPA as mediators of cardiac tissue response to transplantation-induced stress. mRNA expression of these molecules was measured in left ventricular biopsies from 200 donors before and after aortic cross-clamping and at 10-, 30- and 60-min reperfusion by real-time RT-PCR. HIF-1alpha expression at two time points was significantly associated with PGD, as shown by univariate analysis, receiver operating characteristic curve and multivariate logistic regression. At a cut-off level of 200 arbitrary units, HIF-1alpha after aortic cross-clamping in donors (78% sensitivity, 83% specificity) and at 10-min reperfusion (85% sensitivity, 83% specificity) identified PGD. HIF-1alpha demonstrates the potential to be a predictive marker for PGD; however, as multiple factors were tested at different time points, prospective evaluation is clearly necessary to confirm this observation.

Molecular signature of CD34+ hematopoietic stem and progenitor cells of patients with CML in chronic phase

In this study, we provide a molecular signature of highly enriched CD34+ cells from bone marrow of untreated patients with chronic myelogenous leukemia (CML) in chronic phase in comparison with normal CD34+ cells using microarrays covering 8746 genes. Expression data reflected several BCR-ABL-induced effects in primary CML progenitors, such as transcriptional activation of the classical mitogen-activated protein kinase pathway and the phosphoinositide-3 kinase/AKT pathway as well as downregulation of the proapoptotic gene IRF8. Moreover, novel transcriptional changes in comparison with normal CD34+ cells were identified. These include upregulation of genes involved in the transforming growth factorbeta pathway, fetal hemoglobin genes, leptin receptor, sorcin, tissue inhibitor of metalloproteinase 1, the neuroepithelial cell transforming gene 1 and downregulation of selenoprotein P. Additionally, genes associated with early hematopoietic stem cells (HSC) and leukemogenesis such as HoxA9 and MEIS1 were transcriptionally activated. Differential expression of differentiation-associated genes suggested an altered composition of the CD34+ cell population in CML. This was confirmed by subset analyses of chronic phase CML CD34+ cells showing an increase of the proportion of megakaryocyte-erythroid progenitors, whereas the proportion of HSC and granulocyte-macrophage progenitors was decreased in CML. In conclusion, our results give novel insights into the biology of CML and could provide the basis for identification of new therapeutic targets.

Saccharomyces cerevisiae as delivery vehicle for a NY-ESO-1 protein vaccine

2578

Background: Vaccine strategies that target or activate dendritic cells in order to elicit potent cellular immunity are currently the subject of intense research. Here we report that genetically engineered yeast expressing the full-length tumor associated antigen NY-ESO-1 are a versatile host for protein production eliciting MHC class I and II T-cell responses. Methods: The pYD1 yeast display vector was chosen for full length NY-Eso-1 protein (pNY-ESO-1) expression. NY-ESO-1 and SSX-2 (as control) protein were affinity purified on. IFN-g ELISPOT assays were performed in triplicates on nitrocellulose-lined 96-well plates. MHC class I cross-presentation of peptide epitopes was demonstrated by blocking T-cell responses against DCs. For this purpose, antigen or peptide pulsed DCs were labeled with different doses (100, 10, 1 μg/ml) of antibodies specific for HLA-A2/peptide complexes (HLA-A2/ NY-Eso-1157–165; 3M4E5) or an irrelevant antibody (specific for HLA-A2/IMP58–66) as control. Results: Highest level of NY-ESO-1 expression was detected on the cell wall of wt EBY100 strain with lower expression levels on PMT deficient strains PMT-2 and PMT-4. After protein feeding of immature DCs, NY-ESO-1 157–165 peptide cross-presentation was detected by 3M4E5 and an antigen-specific CD8+ T cell clone. There was a strong positive correlation between the amount of Aga2p-NY-ESO-1 protein (0–15μg/ml) and peptide presentation. Specific T-cell recognition of NY-Eso-1 157–165/HLA-A2 complexes was validated by blocking experiments with Fab 3M4E5. Pre-incubation of protein fed DCs with the antibody at different concentrations (0–100 μg/ml) resulted in a significant reduction (p< 0.05) of spot numbers. Efficient presentation and T-cell recognition of epitope 157–165 was only adequately detectable when protein produced by EBY100 wt yeast strain was used (p < 0.05). MHC class II presentation was studied in an autologous setting using a T-cell line recognising the NY-ESO-1 157–170 in HLA-DP4 context revealing that NY-ESO-1 protein produced in yeast was efficiently taken up and presented. Conclusions: Together, these data add further evidence that yeast expressing recombinant proteins can be used for vaccine purposes and that antigen uptake in APC depends on glycoslation of yeast expressed antigens.

No significant financial relationships to disclose.

Successful transplantation of peripheral blood stem cells mobilized by chemotherapy and a single dose of pegylated G-CSF in patients with multiple myeloma

Following induction therapy and 4 g/m(2) cyclophosphamide, a single dose of 12 mg polyethyleneglycol-conjugated G-CSF (pegfilgrastim; n=12) or daily doses of unconjugated G-CSF (8.5 mug/kg/day) (n=12) were administered to myeloma patients. Pegfilgrastim was associated with an earlier leukocyte recovery (12 vs 14 days) and peripheral blood CD34+ cell peak (12 vs 15 days). The peripheral blood CD34+ cell peak was lower in the pegfilgrastim group (78 vs 111/mul). Following high-dose melphalan (200 mg/m(2)) and autografting, leukocyte and platelet reconstitution was similar in both groups and stable blood counts were observed 100 days post transplant. In summary, a single dose of pegfilgrastim after chemotherapy is capable of mobilizing a sufficient number of CD34+ cells for successful autografting with early engraftment and sustained hematological reconstitution in patients with myeloma. These data provide the basis for randomized studies evaluating the optimal dose and time of pegfilgrastim as well as long-term outcome in larger cohorts of patients.