The COX-2 G/C -765 polymorphism may modulate the occurrence of cerebrovascular ischemia.

In the atherosclerotic plaque, cyclooxygenase-2 (COX-2) catalyzes prostaglandin E formation, which acts as a pro-atherogenic factor. A polymorphism, G/C -765, within the COX-2 promoter region modulates gene expression and the risk of cerebrovascular disease. We have evaluated the relation between COX-2 G/C -765 genotypes and the occurrence of cerebrovascular ischemia. We evaluated the COX-2 G/C -765 polymorphism in 110 consecutive patients with a documented history of acute ischemic cerebrovascular disease, in 110 age-matched and sex-matched subjects without such history, and in a general population (n = 324) from the same ethnical background. The frequency of the COX-2 -765C allele in patients [0.21; 95% confidence interval (CI), 0.16-0.26] was similar to those found in controls (0.28; 95% CI, 0.22-0.34) and in the general population (0.26; 95% CI, 0.23-0.29). Carriers of the CC genotype differed between patients (0.02; 95% CI, 0.00-0.05) and controls [0.10 (95% CI, 0.04-0.16), P = 0.019; odds ratio, 0.17 (95% CI, 0.04-0.79)] or the general population [0.08 (95% CI, 0.05-0.11), P = 0.023; odds ratio, 0.22 (95% CI, 0.05-0.95)]. In a multiple logistic regression analysis adjusted for confounding variables, smoking status (P < 0.001), atrial fibrillation (P = 0.004) and COX-2 G/C-765 polymorphism (P = 0.016) independently contributed to cerebrovascular ischemia, with CC carriers exhibiting a lower risk (odds ratio, 0.07; 95% CI, 0.01-0.61). Our data show an association between the COX-2 G/C-765 gene polymorphism and cerebrovascular ischemia, suggesting that the COX-2 gene is a susceptibility locus for the risk of cerebrovascular ischemic disease.     

Methylation of O6-methylguanine DNA methyltransferase and loss of heterozygosity on 19q and/or 17p are overlapping features of secondary glioblastomas with prolonged survival.

PURPOSE: Recent data suggest that methylation of the DNA repair gene O(6)-methylguanine DNA methyltransferase (MGMT), by increasing the chemosensitivity of glioblastoma multiforme, is significantly associated with improved prognosis. Results in contradiction with these findings, however, are present in the literature and the clinical and genetic context framing MGMT methylation is poorly characterized. EXPERIMENTAL DESIGN: To address these issues, we have investigated the MGMT methylation status, clinical and magnetic resonance imaging characteristics, and relevant genetic features (loss of heterozygosity on 17p and 19q, EGFR amplification, and p53 mutations) in a retrospective study on 86 patients affected by glioblastoma multiforme: 72 patients had a clinical history indicating de novo insurgence of the tumor and the remaining 14 were secondary glioblastoma multiforme. RESULTS: MGMT methylation was detected by methylation-specific PCR in 41 of 86 cases (47.7%; Meth+). Progression-free survival and overall survival were significantly longer in Meth+ than in Meth- patients [10 versus 7 months (P=0.003, log-rank test) and 18 versus 14 months (P=0.0003, log-rank test), respectively]. Mixed-nodular enhancement at magnetic resonance imaging was significantly more frequent in Meth+ and secondary glioblastoma multiforme and ring enhancement in Meth- and primary glioblastoma multiforme (P<0.005). MGMT methylation was more present in secondary glioblastoma multiforme (P=0.006) and associated with loss of heterozygosity on 17p and/or 19q (P=0.005). CONCLUSIONS: These observations suggest that MGMT methylation is part of a genetic signature of glioblastomas that developed from lower-grade gliomas.     

Glucuronoxylomannan, a microbial compound, regulates expression of costimulatory molecules and production of cytokines in macrophages

Glucuronoxylomannan (GXM) is a microbial compound that can modulate the immune response. We investigated (1) the receptors involved in uptake of GXM on monocyte-derived macrophages (MDMs) from healthy donors, (2) the effects of GXM on expression of specific receptors, (3) the effects of GXM mediated by pattern-recognition receptors, and (4) GXM modulation of MDM accessory and secretory functions. Cellular receptors involved in uptake of GXM included Fc gamma RII, CD18, Toll-like receptor (TLR) 4, and CD14. Some biological functions of MDMs were profoundly affected by treatment with GXM, resulting in (1) increased expression of CD40 and CD86 via perturbation of TLR4, (2) decreased expression of major histocompatibility complex class II, (3) induction of interleukin-10 but not of tumor necrosis factor-alpha, and (4) decreased lipopolysaccharide (LPS)-induced production of cytokines. GXM represents an attractive compound to limit inflammatory processes and induce an LPS-tolerant state.     

Biosynthesis of a D-amino acid in peptide linkage by an enzyme from frog skin secretions

d-amino acids are present in some peptides from amphibian skin. These residues are derived from the corresponding L-amino acids present in the respective precursors. From skin secretions of Bombinae, we have isolated an enzyme that catalyzes the isomerization of an L-Ile in position 2 of a model peptide to D-allo-Ile. In the course of this reaction, which proceeds without the addition of a cofactor, radioactivity from tritiated water is incorporated into the second position of the product. The amino acid sequence of this isomerase could be deduced from cloned cDNA and genomic DNA. After expression of this cDNA in oocytes of Xenopus laevis, isomerase activity could be detected. Polypeptides related to the frog skin enzyme are present in several vertebrate species, including humans.     

Evaluation of two doses of recombinant luteinizing hormone supplementation in an unselected group of women undergoing follicular stimulation for in vitro fertilization

OBJECTIVE: To evaluate the efficacy of two doses of recombinant (r)LH, 75 IU (recommended) or 37.5 IU, for follicular stimulation and outcomes in a randomized cohort of IVF patients. DESIGN: Randomized, prospective analysis. SETTING: Private hospital incorporating an established IVF center. PATIENT(S): Women undergoing IVF who had a body mass index >18 or <35 and no abnormal karyotype, anovulation, oligomenorrhea, or any known endocrinopathy/illness. INTERVENTION(S): Pituitary desensitization was achieved with triptorelin (0.1 mg SC), and gonadotropin stimulation was performed with either rFSH alone (group A) or in combination with rLH in one of two doses: 37.5 IU (group B) or 75 IU (group C), daily. MAIN OUTCOME MEASURE(S): A range of endocrinologic, embryologic, clinical, and outcome parameters were evaluated. RESULT(S): With rLH supplementation there was a significant increase in the incidence of implantation (9% for rFSH only [group A] vs. 11% and 16% with 37.5 IU rLH and 75.0 IU rLH [groups B and C], respectively) and clinical pregnancy (19% vs. 23% and 31%) (P<.01 and P<.04, respectively), whereas there was no difference in the multiple pregnancy rates. There was a significant (P<.001) increase in the total units of rFSH used in proportion to the amount of rLH supplementation (2,645 U vs. 3,475 U and 3,681 U) and in the level of peripheral E(2) on the day of hCG administration (1,049 pg/mL vs. 1,640 pg/mL and 1,226 pg/mL) (P<.001). There was no significant between difference in mean age, numbers of oocytes recovered, basal and downregulation hormone levels, or the incidence of fertilization in the absence or presence of rLH supplementation, but a higher incidence of grade 1 to 2 embryos was observed when rLH was supplemented. CONCLUSION(S): After pituitary desensitization, there was an increase in the incidence of implantation, clinical pregnancy, and delivery rates in patients stimulated with rFSH supplemented with rLH.     

Selected RD1 peptides for active tuberculosis diagnosis: comparison of a gamma interferon whole-blood enzyme-linked immunosorbent assay and an enzyme-linked immunospot assay

We recently set up a gamma interferon (IFN-gamma) enzyme-linked immunospot assay (ELISPOT), using selected early secreted antigenic target 6 (ESAT-6) peptides, that appears specific for active tuberculosis (A-TB). However, ELISPOT is difficult to automate. Thus, the objective of this study was to determine if the same selected peptides may be used in a technique more suitable for routine work in clinical laboratories, such as whole-blood enzyme-linked immunosorbent assay (WBE). For this purpose, 27 patients with A-TB and 41 control patients were enrolled. Our WBE, using the already described selected peptides from ESAT-6 plus three new ones from culture filtrate protein 10, was performed, and data were compared with those obtained by ELISPOT. Using our selected peptides, IFN-gamma production, evaluated by both WBE and ELISPOT, was significantly higher in patients with A-TB than in controls (P < 0.0001). Statistical analysis showed a good correlation between the results obtained by WBE and ELISPOT (r = 0.80, P < 0.001). To substantiate our data, we compared our WBE results with those obtained by QuantiFERON-TB Gold, a whole-blood assay based on region of difference 1 (RD1) overlapping peptides approved for TB infection diagnosis. We observed a slightly higher sensitivity with QuantiFERON-TB Gold than with our WBE (89% versus 81%); however, our test provided a better specificity result (90% versus 68%). In conclusion, results obtained by WBE based on selected RD1 peptides significantly correlate with those generated by ELISPOT. Moreover, our assay appears more specific for A-TB diagnosis than QuantiFERON-TB Gold, and thus it may represent a complementary tool for A-TB diagnosis for routine use in clinical laboratories.     

Establishment of oocyte population in the fetal ovary: primordial germ cell proliferation and oocyte programmed cell death

Strict control of cell proliferation and cell loss is essential for the coordinated functions of different cell populations in complex multicellular organisms. Oogenesis is characterized by a first phase occurring during embryo-fetal life and in common with spermatogenesis, during which mitotic proliferation of the germline stem cells, the primordial germ cells (PGC), prevails over germ cell death. The result is the formation of a relatively high number of germ cells depending on the species, ready to enter sex specific differentiation. In the female, PGC enter into meiosis and become oocytes, thereby ending their stem cell potential. After entering into meiosis in the fetal ovary, oocytes pass through leptotene, zygotene and pachytene stages before arresting in the last stage of meiotic prophase I, the diplotene or dictyate stage at about the time of birth. The most part of oocytes die during the fetal period or shortly after birth. It is widely accepted that in mammals a female is born with a fixed number of oocytes within the ovaries, which over the years progressively decreases without possibility for renewal. Once the oocyte reserve has been exhausted, ovarian senescence, driving what is referred to as the menopause in women, rapidly ensues. The fertile lifespan of a female depends by the size of the oocyte pool at birth and the rapidity of the oocyte pool depletion. Which mechanisms control PGC proliferation? Why do most of the oocytes die during fetal life and what are the mechanisms of such massive degeneration? Is it possible to prolong the lifespan of a female by reducing oocyte lost during the fetal life? This review reports some of the most recent results obtained in an attempt to answer these questions.     

GnRH antagonist in IVF poor-responder patients: results of a randomized trial

The aim of this prospective study was to evaluate the efficacy of gonadotrophin-releasing hormone antagonist (GnRH) in comparison with the standard long protocol in poor-responder patients. Sixty patients with poor ovarian response in previous treatment cycles were randomized into two groups: group A (n = 30) was stimulated with a standard long protocol, and group B (n = 30) received GnRH antagonist. Vaginal ultrasound was performed to evaluate ovarian response. There was a significantly reduced duration of ovarian stimulation (9.8 +/- 0.8 versus 14.6 +/- 1.2, P = 0.001) in group B in comparison with group A, and a reduced number of ampoules was used in group B (49.3 +/- 4.3 versus 72.6 +/- 6.8, P = 0.0001). In group B, the number of oocytes retrieved was significantly higher than in group A (5.6 +/- 1.6 versus 4.3 +/- 2.2, P = 0.02) and there was an increased number of follicles with a diameter >15 mm at human chorionic gonadotrophin administration in group B (P = 0.0001). Fewer cycles were cancelled with the use of an antagonist protocol. Five pregnancies (17% for embryo transfer) were obtained with GnRH antagonist protocol and two (7% for embryo transfer) with GnRH agonist protocol.