Metoclopramide pharmacokinetics in pregnant and nonpregnant sheep

The pharmacokinetics of metoclopramide was studied in chronically instrumented pregnant and nonpregnant sheep. Metoclopramide was administered to the ewe by intravenous bolus injections (on a crossover basis) of 10, 20, and 40 mg, with an additional 80-mg dose to the nonpregnant animals. Transfer of the drug to the fetus was rapid with significant concentrations in fetal plasma 1 min after maternal dosing. The ratio of fetal-to-maternal area under the plasma concentration-time curves averaged 0.74, indicating significant fetal exposure to the drug. Maternal metoclopramide administration resulted in minimal fetal effects, with no change in arterial pressure, heart rate, or arterial pH or PCO2, and only a small (approximately 1.8 mmHg) transient decline in PO2. Plasma concentrations in maternal and fetal plasma in most animals were best described by a biexponential equation with rapid distribution and elimination phases. The terminal elimination half-lives in maternal and fetal plasma averaged 71.3 and 86.8 min, respectively, with fetal half-life being significantly longer. The number of fetuses present had no consistent effects on either maternal or fetal pharmacokinetic parameters. Total body clearance and volume of distribution averaged 3.5 L/h/kg and 5.8 L/kg, respectively, in the pregnant ewe, and 4.5 L/h/kg and 6.9 L/kg, respectively, in the nonpregnant animals. The terminal elimination half-life in the nonpregnant ewes averaged 67.5 min. Pharmacokinetic parameters were compared in the pregnant and nonpregnant ewes at the 10-, 20-, and 40-mg doses, and no significant differences were observed in the distribution or elimination rate constants, elimination half-life, or volume of distribution.(ABSTRACT TRUNCATED AT 250 WORDS)     

In vitro effects of leukotriene B4 (LTB4) on canine PMN effector function(s)

The canine has become an accepted research model for the examination of a number of human clinical conditions. Despite it's status as a research model, little is known regarding the peripheral effects of inflammatory mediator substances. Products of arachidonic acid metabolism (leukotrienes) are reported capable of altering leukocyte functions. Because of the emerging importance of the canine research model and leukotrienes we examined the effects of leukotriene B₄ (LTB₄) on severalin vitro functions of isolated canine peripheral polymorphonuclear leukocytes (PMN). Changes in forward angle light scatter properties of the cells were used as one measure of PMN activation. Other functional changes examined following LTB₄ pretreatment included chemotactic capability, the electrophysiological state of the cell plasma membrane, and the metabolic oxidative response (i. e. H₂O₂ production). Random cellular movement of PMNs increased by 120% and 72% following preincubation with 10^?7 and 10^?9 M LTB₄, respectively. LTB₄ between 10^?7 and 10^?13 M did not significantly alter cellular resting membrane potential. Between 10^?7 and 10^?9 M LTB₄ elicited significant levels of cellular H₂O₂ production. Although significant, H₂O₂ production was <40% that induced by phorbol myristate acetate (PMA). In numerous respects, caninein vitro PMN responses parallel previous reports of human cell function(s) in the presence of inflammatory mediators and may represent an attractive alternative for investigation of PMN dysfunctions.     

Cumarin derivatives related to calophyllolid (author's transl)

Cumarin Derivatives Related to Calophyllolid Calophyllolid ( 1 ) has been reported to be a strong oral anticoagulant. Ten cumarins related to 1 have now been synthesized. None of them showed anticoagulant activity.     

Impact of viral E2-gene status on outcome after radiotherapy for patients with human papillomavirus 16-positive cancer of the uterine cervix

PURPOSE: Integration of high-risk papillomavirus DNA has been considered an important step in oncogenic progression to cervical carcinoma. Disruption of the human papillomavirus (HPV) genome within the E2 gene is frequently a consequence. This study investigated the influence of episomal viral DNA on outcome in patients with advanced cervical cancer treated with primary radiotherapy. METHODS AND MATERIALS: Paraffin-embedded biopsies of 82 women with locally advanced cervical cancer could be analyzed for HPV infection by multiplex polymerase chain reaction (PCR) by use of SPF1/2 primers. E2-gene intactness of HPV-16-positive samples was analyzed in 3 separate amplification reactions by use of the E2A, E2B, E2C primers. Statistical analyses (Kaplan-Meier method; log-rank test) were performed for overall survival (OS), disease-free survival (DFS), local progression-free survival (LPFS), and distant metastases-free survival (DMFS). RESULTS: Sixty-one (75%) of 82 carcinomas were HPV positive, 44 of them for HPV-16 (72%). Seventeen of the 44 HPV-16-positive tumors (39%) had an intact E2 gene. Patients with a HPV-16-positive tumor and an intact E2 gene showed a trend for a better DFS (58% vs. 38%, p = 0.06) compared with those with a disrupted E2 gene. A nonsignificant difference occurred regarding OS (87% vs. 66%, p = 0.16) and DMFS (57% vs. 48%, p = 0.15). CONCLUSION: E2-gene status may be a promising new target, but more studies are required to elucidate the effect of the viral E2 gene on outcome after radiotherapy in HPV-positive tumors.     

Influence of melanoma inhibitory activity on transforming growth factor-beta signaling in malignant melanoma

Melanoma cells escape transforming growth factor-beta (TGFbeta)-mediated growth inhibition by expressing the Smad (mothers against decapentaplegic homolog, Drosophila) inhibitors Ski and Sno. Here, we demonstrate that melanoma inhibitory activity (MIA) influences the expression of these inhibitors. A Smad responsive reporter construct was activated after TGFbeta1 treatment in the MIA-deficient cell clones but not in the parental cell line. According to this finding, the TGFbeta target genes JunB and Id-1 showed a strong induction of expression. Additional analyses revealed that Ski and Sno, repressors of TGFbeta/SMAD signaling, are not expressed in the MIA-deficient cells but in the parental cell line HMB2 and the mock control. Further investigation showed that Ski and Sno expression might be regulated via the mitogen-activated protein kinase (MAPK)/extracellular signal-regulated kinase (ERK) signaling cascade. Treatment of HMB2 cells with a MEK inhibitor revealed a reduction of Ski and Sno expression, which leads to the conclusion that, in our melanoma cell model, Ski and Sno expression is regulated via MAPK/ERK signaling.     

BRAF and NRAS mutations in melanoma and melanocytic nevi

In this report, we investigated BRAF/NRAS mutations in samples from a case-control study of melanoma and a series of benign melanocytic nevi. We evaluated potential associations between BRAF mutations and histopathologic and pigmentary characteristics of melanoma. Mutations in BRAF and NRAS were detected by sequencing microdissected/laser-captured DNA from 18 in-situ melanomas, 64 primary melanomas, and 51 nevi. Nevi showed the highest frequency of BRAF mutations (82%). BRAF mutations were identified in 29% of invasive melanomas and in only 5.6% of in-situ melanomas. Mutations in NRAS were found in 5.2% of primary melanomas, 5.9% of nevi and no NRAS mutations were seen in in-situ melanomas. A majority of the BRAF mutations observed in primary invasive melanoma were seen in superficial spreading melanoma (15/17), and melanomas with BRAF mutations were also more likely to be found on a body site that was likely to be exposed to intermittent sun exposure compared with chronic or no sun exposure (P=0.02). Tumors with BRAF mutations were also significantly more likely to occur in association with a contiguous nevus (odds ratio 3.49, 95% confidence interval 1.06-11.46), although a contiguous nevus was not found in all melanomas with a BRAF mutation. Our data support the evidence that the mitogen-activated protein kinase pathway is upregulated in a large percentage of melanocytic lesions, but these mutations are not sufficient for malignant transformation. We suggest that BRAF mutations contribute to benign melanocytic hyperplasia, but are likely to contribute to invasive melanoma only in conjunction with other mutations.     

The prevalence of CDKN2A germ-line mutations and relative risk for cutaneous malignant melanoma: an international population-based study.

Germ-line mutations of CDKN2A have been identified as strong risk factors for melanoma in studies of multiple-case families. However, an assessment of their relative risk for melanoma in the general population has been difficult because they occur infrequently. We addressed this issue using a novel population-based case-control study design in which "cases" have incident second- or higher-order melanomas [multiple primary melanoma (MPM)] and "controls" have incident first primary melanoma [single primary melanoma (SPM)]. Participants were ascertained from nine geographic regions in Australia, Canada, Italy, and United States. In the 1,189 MPM cases and 2,424 SPM controls who were eligible and available for analysis, the relative risk of a subsequent melanoma among patients with functional mutations who have an existing diagnosis of melanoma, after adjustments for age, sex, center, and known phenotypic risk factors, is estimated to be 4.3 (95% confidence interval, 2.3-7.7). The odds ratio varied significantly depending on the type of mutation involved. The results suggest that the relative risk of mutation carriers in the population may be lower than currently believed and that different mutations on the CDKN2A gene may confer substantially different risks of melanoma.