[25 hydroxyvitamin D levels and cardiovascular risk in a cohort of patients with advanced chronic kidney disease]

BACKGROUND

Decreased 25 hydroxyvitamin D serum levels have been related to an increase in cardiovascular morbility and mortality in both general population and chronic kidney disease patients. The aim of this study was to evaluate the relationship between 25 hydroxyvitamin D serum level, cardiovascular risk factors and previous established cardiovascular disease in a group of patients with advanced chronic kidney disease.

MATERIAL AND METHODS

We performed a cross-sectional observational study in a cohort of 171 stage 4 and 5 chronic kidney disease outpatients seen in our predialysis clinic, mean age 64.16 +/- 13 years, 59.6% were men, 64.3% had diabetes, 47.3% had obesity, 46.8% had previous cardiovascular disease. 25 hydroxyvitamin D and 1-25 dihydroxyvitamin D were measured, we also determined other routine biochemical parameters. All subjects underwent an echocardiogram and 24 hours ambulatory blood pressure monitoring was also performed.

RESULTS

Mean 25 hydroxyvitamin D levels were 22.1 +/- 13 ng/mL, only 18.7% of the patients had adequate levels, levels were insufficient in 58.5% of the patients and deficient in 22.8% of them. Low 25 hydroxyvitamin D levels were significantly related with age, diabetes, female gender, obesity, MDRD glomerular filtration rate and previous cardiovascular disease. Pulse pressure was the Ambulatory Blood Pressure Monitoring parameter that was better correlated with 25 hydroxyvitamin D levels. We could not find any association between vitamin D levels and other bone and mineral metabolism parameters. No relationship was seen between low vitamin D levels and left ventricular hypertrophy. On multivariate analysis lower levels of 25 hydroxyvitamin D were independently associated with female gender, previous cardiovascular disease, MDRD4-GFR and higher pulse pressure.

CONCLUSIONS

Our study confirm a high prevalence of 25 hydroxyvitamin D insufficiency and deficiency in advanced chronic kidney disease patients, this was associated with the presence of cardiovascular risk markers and previous established cardiovascular disease. However we could not see any relationship with left ventricular hypertrophy which is a known predictor of future cardiovascular events in this population.

Highly purified hMG versus recombinant FSH in ovarian hyperstimulation with GnRH antagonists--a randomized study

BACKGROUND

Highly purified hMG (hp-hMG) has recently shown better cycle outcome than the recombinant FSH (rFSH) when compared in GnRH agonist long protocol cycles. However, they have not yet been compared in GnRH antagonist cycles.

METHODS

A RCT comparing the ongoing pregnancy rate (primary end-point) in 280 patients undergoing IVF/ICSI after stimulation with hp-hMG or rFSH controlled with a GnRH antagonist.

RESULTS

No significant differences were observed between hp-hMG and rFSH in terms of the ongoing pregnancy rate per started cycle (35.0 versus 32.1%, respectively; P = 0.61); relative risk: 1.09 (95% confidence interval: 0.78-1.51; risk difference: 2.9%). No differences were observed for implantation, clinical pregnancy and pregnancy loss rates. More oocytes were obtained from patients receiving rFSH then hMG (14.4 +/- 8.1 versus 11.3 +/- 6.0, respectively; P = 0.001). Estradiol was higher at the end of stimulation in the hp-hMG group (P = 0.02), whereas progesterone was higher in patients stimulated with rFSH (P < 0.001).

CONCLUSIONS

A similar outcome was observed for hp-hMG and rFSH when used for stimulation in GnRH antagonist cycles. However, some differences were found in ovarian response in terms of oocyte yield and hormonal profile. Clinical Trials.gov

TRIAL REGISTRATION NUMBER

NCT00669786.

Cation-induced pi-stacking

The design and synthesis of a new dipyridyl ligand with appended phenanthryl moieties is described. On addition of increments of silver(I) trifluoromethanesulfonate to a solution of the ligand, the phenanthryl protons shift upfield in the (1)H NMR spectrum, suggesting that the phenanthrenes pi-stack on coordination of silver(I). In accord with this, the oxidation potential decreased from 1.74 to 1.55 V on complexation of silver(I). The pi-stacking was confirmed with the single-crystal X-ray structure of a palladium(II) coordination complex.

Paternal and maternal lineages in the Balkans show a homogeneous landscape over linguistic barriers, except for the isolated Aromuns

The Balkan Peninsula is a complex cultural mosaic comprising populations speaking languages from several branches of the Indo-European family and Altaic, as well as culturally-defined minorities such as the Aromuns who speak a Romance language. The current cultural and linguistic landscape is a palimpsest in which different peoples have contributed their cultures in a historical succession. We have sought to find any evidence of genetic stratification related to those cultural layers by typing both mtDNA and Y chromosomes, in Albanians, Romanians, Macedonians, Greeks, and five Aromun populations. We have paid special attention to the Aromuns, and sought to test genetically various hypotheses on their origins. MtDNA and Y-chromosome haplogroup frequencies in the Balkans were found to be similar to those elsewhere in Europe. MtDNA sequences and Y-chromosome STR haplotypes revealed decreased variation in some Aromun populations. Variation within Aromun populations was the primary source of genetic differentiation. Y-chromosome haplotypes tended to be shared across Aromuns, but not across non-Aromun populations. These results point to a possible common origin of the Aromuns, with drift acting to differentiate the separate Aromun communities. The homogeneity of Balkan populations prevented testing for the origin of the Aromuns, although a significant Roman contribution can be ruled out.

The significance of premature luteinization in an oocyte-donation programme

BACKGROUND

Several evidences indicate that premature luteinization (PL) may affect IVF outcome. The primary end-point of the present study was to verify the effect of PL on the pregnancy rate (PR) of our oocyte-donation programme.

METHODS

PL was defined as serum progesterone > or = 1.2 ng/ml on the day of HCG. We analysed retrospectively 240 oocyte-donation cycles in which 120 women donated twice, with PL in the first donation cycle and no PL in the following one, acting as its own control. Recipients (n = 240) were divided in two groups according to the presence of PL (n = 120) or not (n = 120). Both groups were compared regarding donor cycle parameters and recipient cycle outcome.

RESULTS

There was no difference in PR between the groups (55.7 versus 54.4%, respectively). The number of total oocytes (18.2 +/- 0.6 versus 20.8 +/- 0.6; P = 0.003) and the number of mature oocytes retrieved (16.9 +/- 0.6 versus 19.4 +/- 0.6; P = 0.005) were different among donors with progesterone < 1.2 ng/ml and PL, respectively. There were no differences between the oocyte recipients in fertilization, cleavage, embryo division on day 3, blastocyst development or fragmentation rates. The number of embryos transferred, number of embryos cryopreserved, and implantation and miscarriage rates were similar between the groups.

CONCLUSION

PL does not appear to have a negative impact on ongoing PR in our oocyte-donation programme.

Diabetes mellitus and impaired glucose regulation in the Canary Islands (Spain): prevalence and associated factors in the adult population of Telde, Gran Canaria

AIMS

To estimate the prevalence and the determinants of diabetes mellitus and impaired glucose regulation (IGR) in an adult Canarian population.

METHODS

Cross-sectional study. One thousand and thirty subjects aged 30-82 years were randomly selected. Participants completed a survey questionnaire and underwent blood pressure measurements, anthropometry, blood samples, and a 75-g standardized oral glucose tolerance test.

RESULTS

The age-standardized prevalence of diabetes was 15.8% (95% confidence interval: 11.8-19.8) in men and 10.6% (7.1-14.1) in women. Total prevalence was 13.2% (11.1-15.2). Among individuals with diabetes, 55.4% of men and 38.2% of women were not previously diagnosed. The age-standardized prevalences of impaired glucose tolerance and impaired fasting glycaemia were 11.4% (9.5-13.4) and 2.8% (1.8-3.8), respectively. In multivariate analyses, age, waist circumference, serum triglycerides, and familial history of diabetes were independently associated with diabetes in both sexes, while a value of C-reactive protein (CRP) >/= 1 mg/l showed an association with diabetes, but only in men. Age and triglycerides were related to impaired glucose regulation (IGR) in both sexes, waist circumference was related to IGR exclusively in men, and familial diabetes exclusively in women. Statistically significant interactions between gender and both CRP and triglycerides were found with respect to diabetes, and between gender and both waist circumference and triglycerides for IGR.

CONCLUSIONS

Compared with the rest of Spain, the prevalence of diabetes is moderately increased in this area of the Canary Islands. Along with other well-established risk factors, CRP was independently associated with diabetes, but only in the male population.

Considerations on the modelling and optimisation of resolution of ionisable compounds in extended pH-range columns

The problems associated to the modelling and optimisation of the chromatographic resolution of mixtures involving ionisable solutes at varying pH and acetonitrile content are discussed. Several retention models that separate the contributions of solute, column and stationary phase, were used. The retention was predicted with low errors in large pH domains (2-12), which was an essential requirement to face the optimisation of resolution. The selected mixture was particularly problematic under the viewpoint of resolution, owing to the excessively diverse acid-base behaviour of solutes. This variety led to sudden drops in retention at different pH for each solute, yielding numerous peak crossing, which made finding shared regions of high resolution especially difficult. Conventional resolution diagrams for these situations are scarcely informative, since both the overall and the worst elementary resolutions drop to zero if at least two compounds remain overlapped, even when all the others are baseline resolved. A new chromatographic objective function is proposed to address this drawback. This function, called "limiting peak count", is based on the limiting peak purity concept, and measures the success in the resolution focusing on the resolved solutes, in contrast to conventional resolution assessments that attend mainly to the least resolved solutes. Limiting peak count yields the same result as conventional assessments when full resolution is possible, but it is also able to discriminate the maximal resolving power in low-resolution situations. It offers a different perspective to that given by the complementary mobile phases approach, and the computation is far simpler.

Similar endometrial development in oocyte donors treated with either high- or standard-dose GnRH antagonist compared to treatment with a GnRH agonist or in natural cycles

BACKGROUND

This descriptive study evaluates the impact on endometrial development of standard and high doses of a GnRH antagonist in stimulated cycles compared with GnRH agonist and natural cycles.

METHODS

Thirty-one oocyte donors were treated with a combination of rFSH and 0.25 mg/day ganirelix (standard dose), 2 mg/day ganirelix (high dose) or 0.6 mg/day buserelin (long protocol). Vaginal progesterone (200 mg/day) was administered in the luteal phase. Endometrial biopsies were performed 2 and 7 days after HCG administration. Additional biopsies were carried out in a subset of 12 subjects, 2 and 7 days following the LH peak of their previous natural cycle. Biopsies were evaluated histologically and by scanning electron microscopy. Gene expression profiles were also studied.

RESULTS

At HCG +2, all the parameters studied were similar in all the groups and comparable to those observed in the natural cycle. At HCG +7, endometrial dating, steroid receptors and the presence of pinopodes were comparable in both GnRH antagonist groups and in the natural cycle. In buserelin group, endometrial dating and pinopode expression suggested an arrested endometrial development. For window of implantation genes, expression patterns were closer to those in the natural cycle following standard- or high-dose ganirelix than after buserelin administration.

CONCLUSION

No relevant alteration was observed in the endometrial development in the early and mid-luteal phases in women undergoing controlled ovarian stimulation for oocyte donation following daily treatment with a standard- or high-dose GnRH antagonist. In addition, the endometrial development after GnRH antagonist mimics the natural endometrium more closely than after GnRH agonist.

S-100beta and MIA in advanced melanoma in relation to prognostic factors

We compared the sensitivity and specificity of S-100 and MIA in advanced melanoma, in 96 patients with no evidence of disease (NED) and 86 patients with metastatic melanoma. Abnormal S100 (>0.2 microg/l) and MIA (>14 ng/ml) results were found in 1.1% and 3.2% of NED patients and in 59.3% and 54.6% of the patients with active melanoma (p<0.001). Using both tumor markers simultaneously, the sensitivity increased up to 69.8% with the same specificity 96.8%. S100 serum levels were not related to growth patterns. By contrast, MIA levels seemed to be related to the growth pattern, with higher levels in nodular melanoma (60.6+/-87.1 ng/ml) compared with acral-lentigous melanoma (11.9+/-5.4 ng/ml) (p=0.02). Likewise, S100 was related to the metastases site with significantly higher sensitivity and mean concentrations in patients with brain metastases (p=0.01) with the lowest in those with lung MI. MIA was related to the same metastases locations but without statistical significance. In summary, both S100 and ML4 are useful markers related to prognostic factors, being more effective when used in combination.

Anion Control of the Self-Assembly of 2,3-Diarylpyrazines with Silver(I) Salts

The synthesis and characterization of three one-dimensional coordination polymers formed on self-assembly of 2,3-diarylpyrazines with silver(I) salts are presented. A linear double-stranded coordination polymer was formed on self-assembly of 2,3-bis(3'5'-dimethylphenyl)pyrazine with silver(I) tetrafluoroborate. An essentially linear double-strand coordination polymer was formed on self-assembly of 2,3-bis(3'5'-dimethylphenyl)pyrazine with silver(I) trifluoromethanesulfonate. In contrast a helical silver-pyrazine coordination polymer with extensive intrastrand pi-stacking was formed on self-assembly of 2,3-diphenylpyrazine with silver(I) trifluoroacetate.

Silver(I) coordination chemistry of 2,6-diarylpyrazines. Pi-stacking, anion coordination, and steric control

The silver(I) coordination chemistry of 2,6-diarylpyrazines is reported. Discrete coordination complexes and two-dimensional coordination networks were characterized. The substitution pattern on the pendant aryl groups controlled the type of coordination chemistry involved. Thus, o-methyl-substituted aryl groups held the aryl groups orthogonal to the central pyrazine ring, opening the "hindered" nitrogen atoms to complexation, and polymeric networks were characterized. In the absence of the o-methyl groups, discrete coordination complexes were characterized. Thus, a dimeric 2:1 ligand-silver(I) complex was isolated and characterized on reaction of 2,6-bis(3',5'-dimethylphenyl)pyrazine with silver(I) trifluoroacetate in acetonitrile solvent, while a 2:2 complex was isolated from dichloromethane solvent. Two trifluoroacetate ligands bridge two silver cations in both complexes. Reaction of the same pyrazine ligand with silver(I) tetrafluoroborate yielded a discrete 2:1 complex. A 2:1 complex was isolated on reaction of 2,6-diphenylpyrazine with silver(I) nitrate. These complexes were interlinked by weakly coordinating nitrate anions to form interwoven one-dimensional ribbons. Two-dimensional networks were obtained on reaction of silver(I) trifluoroacetate with either 2,6-bis(2',6'-dimethylphenyl)pyrazine or 2-(2',6'-dimethylphenyl)-6-(3',5'-dimethylphenyl)pyrazine. The networks comprised pyrazine-silver(I) strands cross-linked with complex bridged silver(I) trifluoroacetates.

One- and two-dimensional silver-coordination networks containing pi-sandwiched silver-silver interactions

The self-assembly of coordination networks from reaction of 2,4,6-trimesityl-1,3,5-triazine and silver(I) trifluoroacetate is described. A one-dimensional linear polymer is formed from solutions deficient in silver while a two-dimensional, graphite-like sheet is formed from solutions containing 3 equiv of silver per triazine. The structurally similar networks both contain triazine rings separated by two trifluoroacetate-bridged silver atoms. The two silver atoms are effectively sandwiched between two mesityl rings with intermediate arene-silver interactions. The silver-silver bond lengths are 2.9731(4) and 2.9246(5) A in the one-dimensional network and 2.8842(4) A in the two-dimensional network.