Circulating cellular adhesion molecules and risk of diabetes: the Multi-Ethnic Study of Atherosclerosis (MESA)

AIMS

To test the hypothesis that soluble cellular adhesion molecules would be positively and independently associated with risk of diabetes.

METHODS

Soluble levels of six cellular adhesion molecules (ICAM-1, E-selectin, VCAM-1, E-cadherin, L-selectin and P-selectin) were measured in participants in the Multi-Ethnic Study of Atherosclerosis, a prospective cohort study. Participants were then followed for up to 10 years to ascertain incident diabetes.

RESULTS

Sample sizes ranged from 826 to 2185. After adjusting for age, sex, race/ethnicity, BMI and fasting glucose or HbA1c , four cellular adhesion molecules (ICAM-1, E-selectin, VCAM-1 and E-cadherin) were positively associated with incident diabetes and there was a statistically significant trend across quartiles. Comparing the incidence of diabetes in the highest and lowest quartiles of each cellular adhesion molecule, the magnitude of association was largest for E-selectin (hazard ratio 2.49; 95% CI 1.26-4.93) and ICAM-1 (hazard ratio 1.76; 95% CI 1.22-2.55) in fully adjusted models. Tests of effect modification by racial/ethnic group and sex were not statistically significant for any of the cellular adhesion molecules (P > 0.05).

CONCLUSIONS

The finding of significant associations between multiple cellular adhesion molecules and incident diabetes may lend further support to the hypothesis that microvascular endothelial dysfunction contributes to risk of diabetes.

The G-protein-coupled estrogen receptor agonist G-1 suppresses proliferation of ovarian cancer cells by blocking tubulin polymerization

The G-protein-coupled estrogen receptor 1 (GPER) has recently been reported to mediate the non-genomic action of estrogen in different types of cells and tissues. G-1 (1-[4-(6-bromobenzo[1,3] dioxol-5yl)-3a,4,5,9b-tetrahydro-3H-cyclopenta[c]quinolin-8-yl]-ethanone) was developed as a potent and selective agonist for GPER. G-1 has been shown to induce the expression of genes and activate pathways that facilitate cancer cell proliferation by activating GPER. Here we demonstrate that G-1 has an anticancer potential with a mechanism similar to vinca alkaloids, the commonly used chemotherapy drugs. We found that G-1 blocks tubulin polymerization and thereby interrupts microtubule assembly in ovarian cancer cells leading to the arrest of cell cycle in the prophase of mitosis and the suppression of ovarian cancer cell proliferation. G-1 treatment also induces apoptosis of ovarian cancer cells. The ability of G-1 to target microtubules to suppress ovarian cancer cell proliferation makes it a promising candidate drug for treatment of ovarian cancer.

Preliminary evidence of genetic determinants of adiponectin response to fenofibrate in the Genetics of Lipid Lowering Drugs and Diet Network

BACKGROUND AND AIMS

Adiponectin is an adipose-secreted protein that has been linked to changes in insulin sensitivity, high-density lipoprotein cholesterol levels, and inflammatory patterns. Although fenofibrate therapy can raise adiponectin levels, treatment response is heterogeneous and heritable, suggesting a role for genetic mediators. This is the first genome-wide association study of fenofibrate effects on circulating adiponectin.

METHODS AND RESULTS

Plasma adiponectin was measured in participants of the Genetics of Lipid Lowering Drugs and Diet Network (n = 793) before and after a 3-week daily treatment with 160 mg of fenofibrate. Associations between variants on the Affymetrix Genome-Wide Human SNP Array 6.0 and adiponectin were assessed using mixed linear models, adjusted for age, sex, site, and family. We observed a statistically significant (P = 5 × 10⁻⁸) association between rs2384207 in 12q24, a region previously linked to several metabolic traits, and the fenofibrate-induced change in circulating adiponectin. Additionally, our genome-wide analysis of baseline adiponectin levels replicated the previously reported association with CDH13 and suggested novel associations with markers near the PCK1, ZBP1, TMEM18, and SCUBE1 genes. The findings from the single marker tests were corroborated in gene-based analyses. Biological pathway analyses suggested a borderline significant association between the EGF receptor signaling pathway and baseline adiponectin levels.

CONCLUSIONS

We present preliminary evidence linking several biologically relevant genetic variants to adiponectin levels at baseline and in response to fenofibrate therapy. Our findings provide support for fine-mapping of the 12q24 region to investigate the shared biological mechanisms underlying levels of circulating adiponectin and susceptibility to metabolic disease.

Perilipin polymorphism interacts with saturated fat and carbohydrates to modulate insulin resistance

BACKGROUND AND AIMS

Macronutrient intakes and genetic variants have been shown to interact to alter insulin resistance, but replications of gene-nutrient interactions across independent populations are rare, despite their critical importance in establishing credibility. We aimed to investigate a previously demonstrated saturated fat and carbohydrate interaction for insulin resistance for perilipin (PLIN1), a regulator of adipocyte metabolism.

METHODS AND RESULTS

We investigated the previously shown interaction for PLIN1 11482G > A (rs894160) on insulin resistance in US men (n = 462) and women (n = 508) (mean ± SD, 49 ± 16 years). In multivariable linear regression models, we found an interaction (P < 0.05) between the ratio of saturated fat to carbohydrate intake as a continuous variable and PLIN1 11482G > A for HOMA-IR (homeostasis model assessment of insulin resistance) in women. For carriers of the minor allele but not for non-carriers, as the ratio of saturated fat to carbohydrate intake increased, predicted HOMA-IR increased (P = 0.002). By dichotomizing the ratio of saturated fat to carbohydrate intake into high and low, we found significant interaction terms for insulin and HOMA-IR (P < 0.05). When the ratio of saturated fat to carbohydrate was high, insulin and HOMA-IR were higher in minor allele carriers (P = 0.004 and P = 0.003, respectively), but did not differ when the ratio was low. Similar patterns or trends were observed when saturated fat and carbohydrate were dichotomized into high and low as individual macronutrients.

CONCLUSIONS

Replication of the previously reported interaction between macronutrient intakes and PLIN1 genotype for insulin resistance reinforces the potential usefulness of applying genotype information in the dietary management of insulin resistance.

Ethnicity, plasma phospholipid fatty acid composition and inflammatory/endothelial activation biomarkers in the Multi-Ethnic Study of Atherosclerosis (MESA)

BACKGROUND/OBJECTIVES

It has been recognized that certain long-chain polyunsaturated fatty acids (LC-PUFAs) are involved in inflammation and its resolution. It has also been shown that ethnicity may be a factor in affecting systemic inflammation, and limited evidence suggests it may influence plasma LC-PUFA composition. Given the links among these three factors, we aim to determine ethnicity-based differences in plasma LC-PUFA composition among White, Black, Hispanic and Chinese participants, and whether such differences contribute to variations in markers of inflammation and endothelial activation in a sub-cohort of the Multi-Ethnic Study of Atherosclerosis (MESA).

SUBJECTS/METHODS

Plasma phospholipid LC-PUFAs levels (%) were determined in 2848 MESA participants using gas chromatography-flame ionization detection. Enzyme immunoassays determined inflammatory markers levels for high-sensitivity C-reactive protein (n=2848), interleukin-6 (n=2796), soluble tumor necrosis factor-α receptor type 1 (n=998), and endothelial activation markers soluble intercellular adhesion molecule-1 (n=1192) and soluble E-selectin (n=998). The modifying influence of ethnicity was tested by linear regression analysis.

RESULTS

Chinese adults were found to have the highest mean levels of plasma eicosapentaenoic acid (EPA, 1.24%) and docosahexaenoic acid (DHA, 4.95%), and the lowest mean levels of γ-linolenic (0.10%), dihomo-γ-linolenic (DGLA, 2.96%) and arachidonic (10.72%) acids compared with the other ethnicities (all P ≤ 0.01). In contrast, Hispanics had the lowest mean levels of plasma EPA (0.70%) and DHA (3.49%), and the highest levels of DGLA (3.59%; all P ≤ 0.01). Significant differences in EPA and DHA among ethnicities were attenuated following adjustment for dietary non-fried fish and fish oil supplementation. Ethnicity did not modify the associations of LC-PUFAs with markers of inflammation or endothelial activation (all P (interaction)>0.05).

CONCLUSIONS

The absence of a modifying effect of ethnicity indicates that the putative benefits of LC-PUFAs with respect to inflammation are pan-ethnic. Future longitudinal studies may elucidate the origin(s) of ethnicity-based differences in LC-PUFA composition and whether certain patterns, that is, high plasma levels of DGLA and low levels of EPA/DHA, contribute to inflammation-associated health outcomes.

Integration of CNS survival and differentiation by HIF2α

Hypoxia-inducible factor (HIF) 1α and HIF2α and the inhibitor of apoptosis survivin represent prominent markers of many human cancers. They are also widely expressed in various embryonic tissues, including the central nervous system; however, little is known about their functions in embryos. Here, we show that zebrafish HIF2α protects neural progenitor cells and neural differentiation processes by upregulating the survivin orthologues birc5a and birc5b during embryogenesis. Morpholino-mediated knockdown of hif2α reduced the transcription of birc5a and birc5b, induced p53-independent apoptosis and abrogated neural cell differentiation. Depletion of birc5a and birc5b recaptured the neural development defects that were observed in the hif2α morphants. The phenotypes induced by HIF2α depletion were largely rescued by ectopic birc5a and birc5b mRNAs, indicating that Birc5a and Birc5b act downstream of HIF2α. Chromatin immunoprecipitation assay revealed that HIF2α binds to birc5a and birc5b promoters directly to modulate their transcriptions. Knockdown of hif2α, birc5a or birc5b reduced the expression of the cdk inhibitors p27/cdkn1b and p57/cdkn1c and increased ccnd1/cyclin D1 transcription in the surviving neural progenitor cells. The reduction in elavl3/HuC expression and enhanced pcna, nestin, ascl1b and sox3 expression indicate that the surviving neural progenitor cells in hif2α morphants maintain a high proliferation rate without terminally differentiating. We propose that a subset of developmental defects attributed to HIF2α depletion is due in part to the loss of survivin activity.

ADAM17_i33708A>G polymorphism interacts with dietary n-6 polyunsaturated fatty acids to modulate obesity risk in the Genetics of Lipid Lowering Drugs and Diet Network study

BACKGROUND AND AIMS

The disintegrin and metalloproteinase ADAM17, also known as tumor necrosis factor alpha converting enzyme, is expressed in adipocytes. Importantly, elevated levels of ADAM17 expression have been linked to obesity and insulin resistance. Therefore, the aim of this study was to evaluate the association of six ADAM17 single nucleotide polymorphisms (SNPs) (m1254A>G, i14121C>A, i33708A>G, i48827A>C, i53440C>T, and i62781G>T) with insulin-resistance phenotypes and obesity risk, and their potential interactions with dietary polyunsaturated fatty acids (PUFA).

METHODS AND RESULTS

ADAM17 SNPs were genotyped in 936 subjects (448 men/488 women) who participated in the Genetics of Lipid Lowering Drugs and Diet Network (GOLDN) study. Anthropometrical and biochemical measurements were determined by standard procedures. PUFA intake was estimated using a validated questionnaire. G allele carriers at the ADAM17_m1254A>G polymorphism exhibited significantly higher risk of obesity (P=0.003), were shorter (P=0.017), had higher insulin (P=0.016), and lower HDL-C concentrations (P=0.027) than AA subjects. For the ADAM17_i33708A>G SNP, homozygotes for the A allele displayed higher risk of obesity (P=0.001), were heavier (P=0.011), had higher BMI (P=0.005), and higher waist measurements (P=0.023) than GG subjects. A significant gene-diet interaction was found (P=0.030), in which the deleterious association of the i33708A allele with obesity was observed in subjects with low intakes from (n-6) PUFA (P<0.001), whereas no differences in obesity risk were seen among subjects with high (n-6) PUFA intake (P>0.5)

CONCLUSION

These findings support that ADAM17 (m1254A>G and i33708A>G) SNPs may contribute to obesity risk. For the ADAM17_i33708A>G SNP, this risk may be further modulated by (n-6) PUFA intake.

The effect of a novel intergenic polymorphism (rs11774572) on HDL-cholesterol concentrations depends on TaqIB polymorphism in the cholesterol ester transfer protein gene

BACKGROUND AND AIMS

Several genes have been shown to individually affect plasma lipoprotein metabolism in humans. Studies on gene-gene interactions could offer more insight into how genes affect lipid metabolism and may be useful in predicting lipid concentrations. We tested for gene-gene interactions between TaqIB SNP in the cholesterol ester transfer protein (CETP) and three novel single nucleotide polymorphisms (SNPs), namely rs11774572, rs7819412 and rs6995374 for their effect on metabolic syndrome (MetS) components and related traits.

METHODS AND RESULTS

The aforementioned SNPs were genotyped in 1002 subjects who participated in the Genetics of Lipid Lowering Drugs and Diet Network (GOLDN) study. Lipids were measured by standard procedures and lipoprotein subfractions, by proton nuclear magnetic resonance spectroscopy. Polymorphism rs11774572 was significantly associated with MetS (P=0.020), mainly driven by the association of the C allele with lower HDL-C (P=0.043) and higher triglycerides (P=0.049) and insulin (P=0.040) concentrations than TT subjects. A significant interaction between SNPs rs11774572 and CETP-TaqIB SNPs was found for HDL-C concentrations (P=0.006) and for HDL (P=0.008) and LDL particle sizes (P=0.009), small LDL (P=0.004), and VLDL concentrations (P=0.021), in which TT homozygotes displayed higher HDL-C concentrations and for HDL and LDL particle sizes, and lower small LDL and VLDL concentrations than C carriers, if they were CETP B2 allele carriers (P values ranging from <0.001 to 0.001).

CONCLUSIONS

The rs11774572 polymorphism may play a role in the dyslipidemia that characterizes MetS. The interaction between rs11774572 and CETP-TaqIB SNPs on HDL-C concentrations provides some insights into the underlying mechanisms.

A Bayesian spatial multimarker genetic random-effect model for fine-scale mapping

Multiple markers in linkage disequilibrium (LD) are usually used to localize the disease gene location. These markers may contribute to the disease etiology simultaneously. In contrast to the single-locus tests, we propose a genetic random effects model that accounts for the dependence between loci via their spatial structures. In this model, the locus-specific random effects measure not only the genetic disease risk, but also the correlations between markers. In other words, the model incorporates this relation in both mean and covariance structures, and the variance components play important roles. We consider two different settings for the spatial relations. The first is our proposal, relative distance function (RDF), which is intuitive in the sense that markers nearby are likely to correlate with each other. The second setting is a common exponential decay function (EDF). Under each setting, the inference of the genetic parameters is fully Bayesian with Markov chain Monte Carlo (MCMC) sampling. We demonstrate the validity and the utility of the proposed approach with two real datasets and simulation studies. The analyses show that the proposed model with either one of two spatial correlations performs better as compared with the single locus analysis. In addition, under the RDF model, a more precise estimate for the disease locus can be obtained even when the candidate markers are fairly dense. In all simulations, the inference under the true model provides unbiased estimates of the genetic parameters, and the model with the spatial correlation structure does lead to greater confidence interval coverage probabilities.

Photoluminescence of Si nanocrystallites and amorphous oxygen-containing si nanoparticles: the reversible effect of ambient atmosphere on luminescence

Si nanocrystallites of various sizes and oxygen-containing Si nanoparticles with different oxygen contents were prepared by vapor condensation. The Si nanocrystallites showed a visible light emission from 500 nm to 900 nm with the peak at 800 nm, and the intensity of photoluminescence increased with decreasing the particle size. This photoluminescence observed in vacuum could be quenched by air and hydrogen, and reappeared after the sample chamber was evacuated. The oxygen-containing Si nanoparticles consisting mainly of Si oxide were amorphous and had an average particle size of approximately 20 nm. Increasing the oxygen content of nanoparticles caused a blueshift of the absorption edge in the transmission spectra. A blue-green photoluminescence with two peaks at 500 nm and 800 nm was observed from these oxygen-containing Si nanoparticles. The luminescence intensity increased with the oxygen content of nanoparticles, and was very sensitive to the ambient atmosphere. Much lower intensity was observed in air, but higher intensity could be recovered in vacuum. Surface states and oxygen-induced luminescent centers were proposed to be responsible for the photoluminescence from the Si nanocrystallites and oxygen-containing Si nanoparticles, respectively. The reversible ambient effect in both cases could be explained by surface charge redistribution during the gas adsorption and desorption processes.

On the formation and photoluminescence of Si(1-x)Ge(x) nanoparticles

Si(1-x)Ge(x) nanoparticles were prepared from two annealed alloy ingots at the compositions of Si:Ge = 9.5:0.5 and 9:1 using a vapor condensation technique under Ar atmosphere. These nanoparticles are all spherical, and increasing the working pressure leads to an increased particle size and size dispersion. Comparing to the alloy ingots, the nanoparticles have a higher average content of Ge. In addition, increasing the working pressure also causes the Si(1-x)Ge(x) nanoparticles to become more Ge-rich. This can be ascribed to the lower melting point and higher kinetic energy of Ge than Si during the evaporation process. The photoluminescence of Si(1-x)Ge(x) nanoparticles ranges from visible light to infrared region, and the luminescence peak exhibits a red shift as the Ge content in the nanoparticles increases. This indicates that the incorporation of Ge into Si has a dominant effect in the radiative recombination process, in comparison with the constant luminescence peak position in the case of pure Si nanoparticles with similar size distribution.

Nonadditive interactions in protein folding: the zipper model of cytochrome C

Hydrogen exchange experiments (Krishna et al. in J. Mol. Biol. 359:1410, 2006) reveal that folding-unfolding of cytochrome c occurs along a defined pathway in a sequential, stepwise manner. The simplified zipper-like model involving nonadditive coupling is proposed to describe the classical "on pathway" folding-unfolding behavior of cytochrome c. Using free energy factors extracted from HX experiments, the model can predict and explain cytochrome c behavior in spectroscopy studies looking at folding equilibria and kinetics. The implications of the proposed model are discussed for such problems as classical pathway vs. energy landscape conceptions, structure and function of a native fold, and interplay of secondary and tertiary interactions.

Factor VII coagulant activity, factor VII -670A/C and -402G/A polymorphisms, and risk of venous thromboembolism

BACKGROUND

Most epidemiological studies have found no association between levels of factor (F) VII:C and venous thromboembolism (VTE). Our Longitudinal Investigation of Thromboembolism Etiology (LITE) had, in contrast, reported an independent, increased risk of VTE after 7.8 years of follow-up for those with high baseline levels of FVII:C.

OBJECTIVE

To confirm whether FVII:C is associated with VTE after 12.6 years of follow-up and to examine whether two FVII gene polymorphisms (-670A/C and -402G/A) are related to VTE occurrence.

METHODS

In 19 091 LITE participants with no prior history of VTE or cancer, we measured FVII:C at baseline and identified 404 new VTEs. We also performed a nested case-control study to relate the polymorphisms to VTE (n = 490 without exclusion for cancer or prior VTE).

RESULTS

FVII:C was not independently associated with VTE occurrence after extended follow-up. Multivariable-adjusted rate ratios for VTE were 1.00, 1.00, 0.94, 1.00, and 1.38 (P-trend = 0.48) for the <25th, 25th-49th, 50th-74th, 75th-94th, and >or=95th percentiles of FVII:C, respectively. The -670C and -402A alleles were in high linkage disequilibrium, and both were associated with greater FVII:C levels. However, neither polymorphism was associated with VTE occurrence.

CONCLUSION

After extended follow-up, LITE offers little evidence that a greater FVII level is a risk factor for VTE.

ABO blood group, other risk factors and incidence of venous thromboembolism: the Longitudinal Investigation of Thromboembolism Etiology (LITE)

BACKGROUND

Numerous case-control studies have reported higher prevalence of non-O blood type among venous thromboembolism (VTE) patients than controls, but potential mechanisms or effect modifiers for the association are not fully established.

PATIENTS/METHODS

Using a nested case-control design combining the Atherosclerosis Risk in Communities and the Cardiovascular Health Study cohort, ABO blood type and other VTE risk factors were measured on pre-event blood samples of 492 participants who subsequently developed VTE and 1008 participants who remained free of VTE.

RESULTS

A total of 64.4% of cases and 52.5% of controls had non-O blood type. Among controls, mean values of factor VIIIc (FVIIIc) and von Willebrand factor among the non-O blood type group were higher than among the O group. Compared with O blood type, the age-adjusted odds ratio (OR) of VTE for non-O blood type was 1.64 (95% CI, 1.32-2.05) and was similar for the two parent studies and race groups. Further adjustment for sex, race, body mass index, diabetes mellitus and FVIIIc reduced the OR: 1.31 (95% CI, 1.02-1.68). Factor V Leiden (FV Leiden) appeared to modify the non-O blood type association with VTE in a supra-additive fashion, with an age-, sex- and race-adjusted OR of 6.77 (95% CI, 3.65-12.6) for having both risk factors.

CONCLUSIONS

Non-O blood type was independently associated with risk of VTE, and added to the risk associated with FV Leiden.

Cloning and nucleotide sequencing of the second internal transcribed spacer of ribosomal DNA for three species of Eimeria from chickens in Taiwan

Coccidiosis of chickens caused by protozoan parasites of the genus Eimeria (Coccidia: Eimeriidae) is an enteric disease that results in great economic losses throughout the world, including Taiwan. Using polymerase chain reaction (PCR) with primers specific for the second internal transcribed spacer (ITS-2) of ribosomal DNA (rDNA), three species of Eimeria, E. tenella, E. maxima, and E. acervulina have been successfully characterised from chickens in Taiwan. The sizes of PCR products from various isolates representing these three species were between 370 and 580 base pairs (bp). After cloning and sequencing of the PCR products, high nucleotide sequence identity (96.8-100%) was observed within a species. In addition, ITS-2 nucleotide sequences for E. tenella had higher homology (98.5-99.3%) than E. maxima (81.6-96.5%) when compared with appropriate sequences deposited in GenBank. To our knowledge, this is the first report of a 412-bp ITS-2 sequence for E. acervulina from chickens.

Relation of C-reactive protein and other cardiovascular risk factors to penile vascular disease in men with erectile dysfunction

Erectile dysfunction (ED) may be an early sign or symptom of cardiovascular disease (CVD). We examined the relation of traditional and emerging risk factors for CVD to the severity of penile vascular disease in men with ED and without clinical coronary artery disease (CAD). In total, 137 men with ED were evaluated for penile vascular disease severity by penile Doppler ultrasound. These men were divided into the following groups based on ultrasound results: normal, cavernous venous occlusive disease, mild arterial insufficiency, and severe arterial insufficiency. Traditional (fasting lipid panel, fasting glucose, age, BMI, smoking, Framingham coronary artery disease risk score) and emerging (C-reactive protein, Lp(a), homocysteine) risk factors for CVD were correlated to severity of penile vascular disease in men with ED and without clinical CAD. Using univariate analysis, penile Doppler groups showed significant positive correlation to CRP (r=0.21; < or = 0.05) and age (r=0.30; < or = 0.01). For CRP, this correlation remained significant even when adjusted for age (< or = 0.05). Men displaying evidence of penile arterial disease (mild and severe arterial insufficiency) were characterized by elevated CRP levels (0.17 mg/dl) compared to men with no evidence of arterial abnormalities in the penis (0.04 mg/dl). CRP levels correlate significantly with increasing severity of penile vascular disease as measured by penile Doppler.

Prospective study of the A455V polymorphism in the thrombomodulin gene, plasma thrombomodulin, and incidence of venous thromboembolism: the LITE Study

Plasma thrombomodulin (soluble TM; sTM) is considered to be a marker of endothelial injury, but a recent report indicated that the relationship of sTM with thrombosis is complex. Venous thromboembolic events were identified in adults in two longitudinal cohort studies, the Atherosclerosis Risk in Communities Study and the Cardiovascular Health Study, totaling 21 690 participants. After 8 years of follow-up, sTM was measured in baseline plasma of 305 participants who developed venous thrombosis and 607 who did not. Thrombomodulin A455V genotype was determined in 302 cases and 626 controls. There was no difference in the prevalence of the three TM genotypes between cases and controls and no difference in age-adjusted mean values of sTM by genotype. There were no associations of age-adjusted sTM or TMA455V genotype with overall venous thromboembolism or with thrombosis in any subtype of venous thromboembolism.

Effect of retinoic acid on implantation and post-implantation development of mouse embryos in vitro

BACKGROUND

This study was designed to examine the embryotoxic potential of retinoic acid (RA) at the blastocyst stage and during early post-implantation development of mouse embryos in vitro.

METHODS AND RESULTS

All-trans retinoic acid (t-RA) was administered to ICR mice embryos at a dose level of 0, 0.001 micromol/l, 0.1 micromol/l and 10 micromol/l throughout in-vitro culture. A total of 404 embryos was randomly assigned to all different dose groups. The percentage of embryos in later stages of development changed depending upon the dose of RA used. Exposure to 10 micromol/l of t-RA at the blastocyst stage, implanted blastocyst stage or early oocyte stage was also found to cause different degrees of retardation of embryo development and embryo death. These findings demonstrate, for the first time, that RA exerts an adverse effect on embryo growth during the early post-implantation stages of development, in comparison with day 3 to day 8 of gestation in vivo.

CONCLUSIONS

Although isotretinoin (13-cis-retinoic acid) is effective for the therapy of cystic acne and other dermatological disorders, retinoid treatment should be avoided at the early post-implantation stage of gestation.

Cystatin C is an independent predictor of fasting and post-methionine load total homocysteine concentrations among stable renal transplant recipients

BACKGROUND

An increased prevalence of hyperhomocysteinemia with an increased incidence of cardiovascular disease events has been reported among stable renal transplant recipients (RTRs). Preliminary studies in a small number of these individuals have shown that serum creatinine and cystatin C, both markers of kidney function and glomerular filtration rate, are independent determinants of fasting tHcy concentrations; however, determinants of tHcy concentrations after a methionine load have not been studied.

METHODS

We determined the prevalence of both fasting and 4-h post-methionine load (PML) tHcy concentrations in 78 stable RTRs and compared the role of cystatin C with the role of serum creatinine as determinants of fasting and PML tHcy.

RESULTS

Of the 78 RTRs, 21 (26.9%) had fasting and PML tHcy within the respective reference intervals, and 57 (73.1%) had increased plasma tHcy. Of these 57 RTRs, 22 had fasting hyperhomocysteinemia, 9 had PML hyperhomocysteinemia, and 26 had combined hyperhomocysteinemia (both fasting and PML). Unadjusted Pearson correlations showed that fasting plasma tHcy correlated with both cystatin C (r = 0.564; P <0.001) and creatinine (r = 0.519; P <0.001) and that increases in PML tHcy modestly correlated with cystatin (r = 0.205; P = 0.072), but not creatinine (r = 0.057; P = 0.624). General linear regression modeling with stepwise analysis of covariance showed that both cystatin C (partial R = 0.554; P <0.001) and creatinine (partial R = 0.535; P <0.001) were independent predictors of fasting tHcy, but of the two, only cystatin C (partial R = 0.242; P = 0.035) was an independent predictor of increased PML tHcy.

CONCLUSIONS

Clinically stable RTRs have an excess prevalence of moderate hyperhomocysteinemia, and additional cases can be detected by methionine loading. Both creatinine and cystatin C are independent predictors of fasting tHcy in these individuals; however, only cystatin C is a determinant of tHcy concentration after a methionine load, probably because cystatin C is a more sensitive marker of glomerular filtration rate than serum creatinine.

Surface characterization and platelet adhesion studies of self-assembled monolayer with phosphonate ester and phosphonic acid functionalities

Because of its well-defined surface configuration and creative chemical structure, an alkanethiol self-assembled monolayer (SAM) on gold is a model surface for a blood compatibility investigation. In this study two laboratory-synthesized long-chain alkanethiols, HS(CH(2))(10)PO(3)-(C(2)H(5))(2) and HS(CH(2))(10)PO(3)H(2), were employed for the direct preparation of SAMs with nonionic and ionic functional groups. Various instrumental analyses confirmed the high purity of the phosphonate ester and phosphonic acid terminated alkanethiols. The surface characterization results showed the -PO(3)H(2) terminated SAM was more hydrophilic than the -PO(3)(C(2)H(5))(2) one. Higher hysteresis values for the -PO(3)(C(2)H(5))(2) and -PO(3)H(2) terminated SAMs were noted, which were possibly due to the steric hindrance of the bulky terminal groups. In addition, the O(2) plasma + EtOH-rinse pretreated Au sample was hydrophilic because of the residual gold oxide on the surface. This finding was supported by electron spectroscopy for chemical analysis (ESCA) as well. The ESCA analysis also indicated bulky and polar terminal groups [-PO(3)(C(2)H(5))(2) and -PO(3)H(2)] were situated in the outermost layer of its monolayer. The platelet reactivity on the SAM with the nonionic group -PO(3)(C(2)H(5))(2) was less than those of the ionic terminated SAMs -COOH and -PO(3)H(2). The O(2) plasma + EtOH-rinse pretreated gold substrate exhibited the least platelet-activating surface among the different pretreated Au substrates studied.

C677T and A1298C polymorphisms of the methylenetetrahydrofolate reductase gene: incidence and effect of combined genotypes on plasma fasting and post-methionine load homocysteine in vascular disease

BACKGROUND

Moderately increased plasma concentrations of total homocysteine (tHcy) have been shown to be an important risk factor for vascular diseases. Two common polymorphisms of the methylenetetrahydrofolate reductase (MTHFR) gene, the thermolabile C677T and a more recently reported A1298C polymorphism, may contribute to hyperhomocysteinemia.

METHODS

Using PCR and restriction fragment length polymorphism analysis, we studied the prevalence of the C677T and A1298C MTHFR genotypes and the combined effect of these polymorphisms on plasma tHcy concentrations, as measured by HPLC with fluorometric detection, both fasting and post-methionine load (PML), in 1238 individuals.

RESULTS

The prevalences of the C677T and A1298C genotypes did not differ significantly in 772 individuals with documented coronary artery disease (CAD), 137 individuals with deep-vein thrombosis (DVT), and 329 individuals without documented vascular disease. Individuals homozygous for the 677T allele had significantly increased fasting tHcy, particularly in the presence of low folate, compared with individuals homozygous for the wild-type allele. Neither the 1298AC nor the 1298CC genotype was associated with significantly increased fasting or PML tHcy concentrations irrespective of serum folate. Of the nine combined MTHFR genotypes, six were present in >10% of the population. Of these, the difference in mean fasting tHcy reached statistical significance (P<0.005) only in individuals with the 677TT/1298AA genotype compared with individuals with the wild-type 677CC/1298AA genotype. Differences in mean fasting tHcy did not reach statistical significance in individuals heterozygous for both MTHFR variants. We detected two 677CT/1298CC and three 677TT/1298AC individuals; only one, an 677TT/1298AC individual, had increased tHcy (both fasting and PML). No individuals had the 677TT/1298CC genotype.

CONCLUSIONS

The prevalences of the C677T and A1298C polymorphisms did not differ among individuals with CAD, DVT, or those without documented vascular disease. In contrast to the C677T polymorphism, the A1298C polymorphism is not associated with increased fasting tHcy. Although the two polymorphisms usually exist in trans configuration, crossover may occur rarely to form recombinant chromosomes.

Identification and characterization of androgen receptor associated coregulators in prostate cancer cells

The androgen receptor (AR) is a member of the nuclear receptor (NR) superfamily that mediates the effects of androgens on target tissues. Over the last decade, it has become apparent that NRs require accessory factors for optimal activation of target gene expression. Numerous NR coregulators have been identified, with diverse structures and potential mechanisms of coregulation, creating an increasingly complicated picture of NR action. Due to the expanding complexity of the coregulator field, this review will focus on the AR ligand-binding domain (LBD) and N-terminal interacting proteins identified by our lab. The LBD-interacting proteins ARA70, ARA55 and ARA54 were first characterized and ARA70 was found to have a relatively higher specificity for the AR in human prostate cancer DU145 cells. Characterization of the functional relationship between the AR and these coregulators indicated that ARA70 and ARA55 could enhance the androgenic effects of 17beta-estradiol (E2) and hydroxyflutamide (HF), an antiandrogen commonly used in the treatment of prostate cancer. ARA160, an AR N-terminal interacting protein also known as TATA element modulatory factor (TMF), was subsequently shown to cooperate with ARA70 in enhancing AR activity. Another AR N-terminal interacting protein, ARA24, interacted with the poly-Q tract, a region within the N-terminus of the AR linked to Kennedy's disease (X-linked spinal and bulbar muscular atrophy). More recently, our lab has identified ARA267, a SET domain containing protein, and supervillin, an F-actin binding protein, as AR coregulators. Collectively, the data from these studies indicate that these coregulators are necessary for optimal AR transactivation. Interruption of the interaction between AR and these proteins may serve as a new therapeutic target in the treatment of prostate cancer.

A prospective study of coronary heart disease and the hemochromatosis gene (HFE) C282Y mutation: the Atherosclerosis Risk in Communities (ARIC) study

Increased iron stores may play a role in the development of coronary heart disease (CHD) by increasing lipoprotein oxidation. Recently, mutations have been discovered in the gene (HFE) for hereditary hemochromatosis, an autosomal recessive condition of disordered iron metabolism, absorption, and storage. It is possible that people who carry HFE mutations have increased risk of CHD. We used a prospective case-cohort design (243 CHD cases and 535 non-cases) to determine whether the HFE C282Y mutation was associated with incident CHD in a population-based sample of middle-aged men and women. The frequencies of homozygosity and heterozygosity for the C282Y mutation in the ARIC study population were 0.2% (one homozygous person) and 6%, respectively. The C282Y mutation was associated with nonsignificantly increased risk of CHD (relative risk=1.60, 95% CI 0.9-2.9). After adjusting for other confounding risk factors (age, race, gender, ARIC community, smoking status, diabetes status, hypertension status, LDL cholesterol, HDL cholesterol, and triglycerides), the association became stronger (relative risk=2.70, 95% CI 1.2-6.1). However, a sensitivity analysis showed that this estimate of relative risk was somewhat unstable due to few subjects in some strata. Our prospective findings suggest that individuals carrying the HFE C282Y mutation may be at increased risk of CHD.

Short-term variability in the measurement of plasma homocysteine, fasting and post-methionine loading

OBJECTIVES

Hyperhomocysteinemia is associated with premature cerebral, peripheral and coronary vascular disease. Evaluation of the significance of changes in plasma total homocysteine (tHcy) results obtained by analysis of serial specimens may be accomplished only by taking into account biologic (between-person and within-person) as well as analytical variation. Since the repeatability of a measurement significantly determines our ability to associate tHcy level with the presence of disease, this study was performed to evaluate various components of variation in tHcy values.

DESIGN AND METHODS

We report the within-person, between-person, and methodological variability of tHcy, both fasting and postmethionine load (PML) values, in 20 healthy volunteers from whom samples were drawn weekly for 4 weeks.

RESULTS

The short-term reliability coefficient (R) was 0.72 for fasting tHcy and 0.83 for PML tHcy.

CONCLUSIONS

The current study demonstrates for the first time that the short-term reliability coefficient for PML tHcy is relatively high (0.83), suggesting that an individual's PML tHcy, like fasting tHcy, is relatively constant over at least one month, and that a single measurement should provide a reasonable characterization of an individual's PML tHcy concentration.

Determination of the efficiency of controlled ovarian hyperstimulation in the gonadotropin-releasing hormone agonist-suppression cycle using the initial follicle count during gonadotropin stimulation

PURPOSE

Our purpose was to evaluate the relationship between the initial follicle count during gonadotropin stimulation after gonadotropin-releasing hormone (GnRH) agonist suppression and the efficiency of controlled ovarian hyperstimulation (COH) in patients receiving treatment with assisted reproductive technologies (ARTs).

METHODS

A total of 338 COH procedures in 291 couples was performed with cycles that reached the stage of oocyte retrieval. The ovarian antral follicle number was measured using transvaginal ultrasonography at the folliculometry during gonadotropin stimulation by GnRH agonist suppression in patients undergoing ARTs. Controlled ovarian hyperstimulation was accomplished using GnRH agonist down-regulation combined with FSH and menotropin stimulation. The characteristics of oocytes after retrieval and embryos after in vitro culture and the pregnancy rates were assessed.

RESULTS

The procedures performed included 195 ET cycles, 129 TET cycles, and 14 incomplete cycles. The treatment cycles were divided into four categories according to the antral follicle number (i.e., < or = 5, 6-10, 11-15, and > or = 16) at the first folliculometry to evaluate the influence of various factors. The antral follicle count correlated significantly with the patient age, dosage of gonadotropins, serum estradiol concentration, number of antral follicles (> or = 13 mm) while receiving hCG injections, number of oocytes retrieved, and, later, number of embryos transferred. There was a trend toward an increasing number of pregnancies per cycle as the number of antral follicles increased (14.7, 26.5, 44, and 45%, respectively).

CONCLUSIONS

We were able to predict the efficiency of COH and outcome of ARTs based on the follicle count during the first folliculometry during gonadotropin stimulation after GnRH agonist suppression. The results of the folliculometry significantly predicted the ovarian response to COH and the outcome of ARTs in the current treatment cycle.

Variable number tandem repeat in exon/intron border of the cystathionine beta-synthase gene: a single nucleotide substitution in the second repeat prevents multiple alternate splicing

We studied a large number of individuals with respect to the 31-bp variable number tandem repeat (VNTR) in the cystathionine beta-synthase (CBS) gene. The number of repeats varies from 15-20, with 17 repeats the most common allele. Significantly, we found that the first repeat of the 31-bp VNTR originates 12 bp from the 5' end of exon 13 and extends 19 bp into intron 13. Since this VNTR spans across the exon-intron border, it can theoretically create multiple alternate splice sites. However, a substitution of g-->a at the exon-intron border is uniquely present in the second repeat, preventing alternate splicing at that site. While the g-->a substitution is absent from all subsequent 31-bp repeats, alternate splicing probably does not occur at those distal sites due to the lack of exon 13 sequences not contained in the repeats but needed for the binding of spliceosomes. Investigation of five individuals with normal plasma total homocysteine (tHcy) and five individuals with mild hyper-homocysteinemia shows that all have the g-->a substitution in the second repeat. Nonetheless, we speculate that the absence of this substitution may be found in rare individuals with normal CBS cDNA and unexplained hyperhomocysteinemia. Gene scanning and direct nucleotide sequencing were used to characterize the VNTR in 398 patients with premature coronary artery disease and 137 controls. Five alleles and 10 genotypes were found; 17/17 is the most prevalent genotype in our study population. The two other prevalent genotypes, 16/17 and 17/18, are associated with significantly decreased tHcy levels as compared to the 17/ 17 genotype, suggesting that the 16 and 18 repeats haplotype may be in linkage disequilibrium with regulatory elements which upregulate CBS gene transcription.

Influence of 699C-->T and 1080C-->T polymorphisms of the cystathionine beta-synthase gene on plasma homocysteine levels

The association of moderately elevated total homocysteine (tHcy) levels with coronary artery disease is increasingly being recognized. However, the role of genetic influence on plasma tHcy levels is not completely understood. We studied 1,055 individuals with respect to the effect of two silent polymorphisms, the 699C--> T and the 1080C-->T, of the cystathionine beta-synthase (CBS) gene on plasma tHcy levels. Individuals who were heterozygous or homozygous for the T699 allele had lower post-methionine load (PML) tHcy levels when compared to individuals with the C/C genotype. This association was statistically significant (p = 0.005) for the T/T genotype compared to the C/C genotype and became even more significant (p = 0.000002) when individuals carrying the 68-bp insertion (844ins68) and the T1080 allele were excluded from the analysis. With regard to the 1080C-->T polymorphism, the T1080 allele was associated with significantly lower PML tHcy levels only when individuals carrying the 844ins68 and T699 allele were excluded from the study (p = 0.01 for 1080T/T genotype compared to 1080C/C genotype). We speculate that the 699C-->T and 1080C-->T polymorphisms may be in linkage disequilibrium with regulatory elements that upregulate CBS gene transcription.

Codon-54 polymorphism of the fatty acid-binding protein 2 gene is associated with elevation of fasting and postprandial triglyceride in type 2 diabetes

Patients with type 2 diabetes are frequently dyslipidemic or hypertriglyceridemic. To assess whether increased intestinal triglyceride input leads to elevated fasting and postprandial triglycerides in type 2 diabetes, we used the codon 54 polymorphism of the fatty acid-binding protein 2 gene, which results in the substitution of threonine (Thr) for alanine and is associated with increased intestinal input of triglyceride. Of the 287 diabetic patients screened, 108 (37.6%) were heterozygous and 31 (10.8%) were homozygous for the Thr-54 allele. Mean (+/-SEM) fasting plasma triglyceride levels in patients with the wild-type (n = 80), those heterozygous for the Thr-54 allele (n = 57), and those homozygous for it (n = 18) were 2.0 +/- 0.09, 2.7 +/- 0.20, and 3.8 +/- 0.43 mmol/L, respectively. A linear relationship of mean fasting plasma triglyceride levels (r2 = 0.97) between the 3 groups was found. After fat ingestion, the postprandial area under the curve of plasma triglyceride (P = 0.025) and chylomicrons (Sf > 400, P = 0.013) was higher in the Thr-54/Thr-54 (n = 6) than in the wild-type (n = 9). Our results are consistent with the hypothesis that, in type 2 diabetes, increased intestinal input of triglyceride can lead to elevated fasting and postprandial plasma triglycerides.

Effects of induction anesthetic agents on outcome of assisted reproductive technology: a comparison of propofol and thiopental sodium

BACKGROUND

The use of propofol, as compared to barbiturates (e.g. thiopental), for short surgical procedures has been associated with more rapid recovery from the procedure. Propofol, an intravenous anesthetic drug, is frequently used as an adjunct to transvaginal oocyte retrieval but little is known about its effects upon fertilization, embryo development, and pregnancy rate when used drug the for induction of general anesthesia. This study was conducted to compare the outcome of assisted reproductive technology (ART) with the use of propofol versus thiopental sodium for the induction of general anesthesia during oocyte retrieval.

METHODS

In this retrospective study, 92 cases of infertile patients who underwent oocyte retrieval under the induction of general anesthesia with, respectively, either propofol (Group I, 72 cases) or thiopental sodium (Group II, 20 cases) were compared for fertilization rate, cleavage rate, and pregnancy rate.

RESULTS

The fertilization rate was 68.9% for Group I and 66.7% for group II (p = 0.614). The cleavage rate was 96.5% for Group I and 94.8% for Group II (p = 0.294). The rate of good embryo grading and poor embryo grading was, respectively, 85.1% and 14.9% for Group I, versus 85.7% and 14.3% for Group II (p = 0.887). The pregnancy rate was 30.5% for Group I and 20.0% for Group II (p = 0.354). The implantation rate and abortion rate was, respectively, 9.1% and 18.2% for Group I versus 7.2% and 25.0% for Group II (implantation rate, p = 0.590; abortion rate, p = 0.600).

CONCLUSION

There were no significant differences between these two groups for fertilization rate, cleavage rate, pregnancy rate, implantation rate and abortion rate. We suggest cautious use of propofol for the procedure of oocyte retrieval despite its associated more rapid post-operative recovery including less nausea/vomiting.

Plasma homocysteine and its association with carotid intimal-medial wall thickness and prevalent coronary heart disease: NHLBI Family Heart Study

Mildly elevated plasma total homocysteine (tHcy) levels have been associated with increased risk of coronary heart disease (CHD). Carotid artery intimal-medial wall thickening is a predictor of cardiovascular disease and has been previously shown to be positively associated with plasma tHcy in studies of asymptomatic subjects. In the current study we examined 1467 subjects with regard to their fasting plasma tHcy levels and intimal-medial wall thickness as measured by B-mode ultrasound and early onset CHD. The results showed that there is a significant positive association between plasma tHcy levels and carotid-artery wall thickness in participants 55 years or older even after the tHcy levels are adjusted for age, smoking and anti-hypertensive medication. The direction and magnitude of the relationship is similar although the result was not statistically significant in younger participants ( < 55 years). Early onset CHD at any age was not significantly different across the tHcy quintiles. The lack of an association of tHcy and CHD in the presence of a positive association with intimal-medial wall thickening may be a reflection of increased statistical power of quantitative versus qualitative traits. We conclude that the present finding of a positive association between tHcy and intimal-medial wall thickness strengthens the in vitro finding of the stimulating effect of homocysteine on vascular smooth muscle cell growth. Vascular smooth muscle cell proliferation may be an important mechanism through which mildly elevated plasma tHcy promotes atherosclerosis.

Effect of hypothermic pulmonary artery flushing on capillary filtration coefficient

BACKGROUND

We previously demonstrated that surfactant dilution and inhibition occur immediately after pulmonary artery flushing with hypothermic modified Euro-Collins solution. Consequently, we speculated that increased capillary permeability contributed to these surfactant changes. To test this hypothesis, we evaluated the effects of hypothermic pulmonary artery flushing on the pulmonary capillary filtration coefficient (Kfc), and additionally performed a biochemical analysis of surfactant.

METHODS

We used a murine isolated, perfused lung model to measure the pulmonary capillary filtration coefficient and hemodynamic parameters, to determine the wet to dry weight ratio, and to evaluate surfactant by biochemical analysis of lung lavage fluid. We defined three study groups. In group I (controls), we harvested lungs without hypothermic pulmonary artery flushing, and measured Kfc immediately. In group II (in situ flush), we harvested lungs after hypothermic pulmonary artery flushing with modified Euro-Collins solution, and then measured Kfc. Experiments in groups I and II were designed to evaluate persistent changes in Kfc after pulmonary artery flushing. In group III (ex vivo flush), we flushed lungs ex vivo to evaluate transient changes in Kfc during hypothermic pulmonary artery flushing.

RESULTS

Groups I and II did not differ significantly in capillary filtration coefficient and hemodynamics. Group II showed significant alterations on biochemical surfactant analysis and a significant increase in wet-to-dry weight ratio, when compared with group I. In group III, we observed a significant transient increase in capillary filtration coefficient during pulmonary artery flushing.

CONCLUSIONS

Hypothermic pulmonary artery flushing transiently increases the capillary filtration coefficient, leads to an increase in the wet to dry weight ratio, and induces biochemical surfactant changes. These findings could be explained by the effects of hypothermic modified Euro-Collins solution on pulmonary capillary permeability.

Cystathionine beta-synthase mutations in homocystinuria

The major cause of homocystinuria is mutation of the gene encoding the enzyme cystathionine beta-synthase (CBS). Deficiency of CBS activity results in elevated levels of homocysteine as well as methionine in plasma and urine and decreased levels of cystathionine and cysteine. Ninety-two different disease-associated mutations have been identified in the CBS gene in 310 examined homocystinuric alleles in more than a dozen laboratories around the world. Most of these mutations are missense, and the vast majority of these are private mutations. The two most frequently encountered of these mutations are the pyridoxine-responsive I278T and the pyridoxine-nonresponsive G307S. Mutations due to deaminations of methylcytosines represent 53% of all point substitutions in the coding region of the CBS gene.

Release of kinesin from vesicles by hsc70 and regulation of fast axonal transport

The nature of kinesin interactions with membrane-bound organelles and mechanisms for regulation of kinesin-based motility have both been surprisingly difficult to define. Most kinesin is recovered in supernatants with standard protocols for purification of motor proteins, but kinesin recovered on membrane-bound organelles is tightly bound. Partitioning of kinesin between vesicle and cytosolic fractions is highly sensitive to buffer composition. Addition of either N-ethylmaleimide or EDTA to homogenization buffers significantly increased the fraction of kinesin bound to organelles. Given that an antibody against kinesin light chain tandem repeats also releases kinesin from vesicles, these observations indicated that specific cytoplasmic factors may regulate kinesin release from membranes. Kinesin light tandem repeats contain DnaJ-like motifs, so the effects of hsp70 chaperones were evaluated. Hsc70 released kinesin from vesicles in an MgATP-dependent and N-ethylmaleimide-sensitive manner. Recombinant kinesin light chains inhibited kinesin release by hsc70 and stimulated the hsc70 ATPase. Hsc70 actions may provide a mechanism to regulate kinesin function by releasing kinesin from cargo in specific subcellular domains, thereby effecting delivery of axonally transported materials.

Comparable clinical outcomes of tubal embryo transfer for oligoastheno-teratozoospermia treated with intracytoplasmic sperm injection and for female infertility treated with in vitro fertilization

BACKGROUND

Female and male indications may each have their negative impacts on the success of assisted reproductive technologies. Reports regarding the outcomes of in vitro fertilization (IVF) vs. intracytoplasmic sperm injection (ICSI) are controversial. This study was conducted to investigate whether the clinical outcome of tubal embryo transfer (TET) for oligoastheno teratozoospermia treated with ICSI is different from that of tubal embryo transfer for female infertility treated with IVF.

METHODS

From January 1997 to December 1998, results of tubal embryo transfers of 54 IVF (IVF-TET) cycles for female infertility were retrospectively compared with those of 49 ICSI (ICSI-TET) cycles for oligoastheno-teratozoospermia.

RESULTS

The fertilization rates were 78.1% +/- 21.8%, and 78.0% +/- 21.9% for treatments with IVF-TET and ICSI-TET, respectively. The implantation rates were 13.8% and 21.2%, respectively. The pregnancy rates per transfer were 46.2% and 48.9%, and the abortion rates were 14.8% and 12.2% for treatments with IVF-TET and ICSI-TET, respectively. The above rates for the IVF-TET and ICSI-TET groups were comparable.

CONCLUSION

Male infertility due to oligoastheno teratozoospermia treated with ICSI-TET appears to have a comparable outcome to female infertility treated with IVF-TET.

Two different timings of intrauterine insemination for non-male infertility

PURPOSE

Our purpose was to assess the simplicity and convenience of treatment scheduled not on weekends, by comparing two different timings of intrauterine insemination (IUI) protocol.

METHODS

A prospective observational study of two different protocols of intrauterine insemination was designed. Two hundred and ten infertile couples with normal spermiograms were included in this study. Fifty-eight couples were treated with IUI 26 to 28 h after human chorionic gonadotropin (hCG) injection plus timed intercourse within a 12- to 18-hr period and 147 couples had IUI 36 to 38 hr after hCG injection and timed intercourse within a 12- to 18-hour period. Pregnancy rates were compared with two different protocols of IUI.

RESULTS

The mean age, duration, and causes of infertility and the cycle characteristics following follicular stimulation were similar between the two groups. The cycle characteristics of follicular stimulation in the two treatment groups were not different. There also were no significant differences between the groups in the type of sperm concentration, sperm motility, and the percentage of sperm with normal morphology per insemination. The number of follicles greater than 17 mm per patient was not significantly different between the two groups. The pregnancy rate per cycle also was similar between the two groups in men with lower motile sperm numbers (< 40 x 10(6)) (23.6% vs. 23.4%) and in men with higher sperm numbers (> or = 40 x 10(6)) (25% vs. 24.4%).

CONCLUSIONS

The different timing but similar efficacy of these two IUI protocols provides a practical choice to clinicians. The availability of both protocols may avoid unnecessary scheduling of clinical and laboratory work on weekends and holidays in women participating in controlled ovarian hyperstimulation and IUI programs for treatment of non-male infertility.

Clinical implications of intracytoplasmic sperm injection using cryopreserved testicular spermatozoa from men with azoospermia

OBJECTIVE

To investigate whether sperm obtained by testicular sperm extraction (TESE) and cryopreserved well before intracytoplasmic sperm injection (ICSI) can serve as an effective sperm source.

STUDY DESIGN

The role of cryopreserved testicular spermatozoa was evaluated in a retrospective analysis of consecutive ICSI cycles using fresh or cryopreserved sperm; they were followed by prospective, planned treatment using cryopreserved sperm with a modified ICSI procedure. Sixteen men (22 cycles) with obstructive or nonobstructive azoospermia were included in the retrospective analysis. Another 25 men (29 cycles) were in the planned treatment group. Following these series, the pregnancy outcomes were compared between ICSI cycles with fresh or cryopreserved testicular sperm.

RESULTS

In the retrospective phase, 14 ICSI cycles were performed using fresh sperm, with 8 using cryopreserved sperm. There were no statistically significant differences between the two groups in any outcome measure. Planned treatment with cryopreserved sperm resulted in a fertilization rate of 84% and an embryo transfer rate of 89%. Thirteen couples (44%) achieved pregnancy (five ongoing, six delivered). These rates were similar to those in the retrospective phase of the study. All couples in the planned cryopreservation group had multiple aliquots (6.5 +/- 2.1) of sperm remaining after the first cycle.

CONCLUSION

Cryopreserved sperm obtained by TESE can be used as an effective sperm source in ICSI cycles. Planned cryopreservation allows multiple aliquots to be stored for use in subsequent cycles and thus avoids the need for repeat biopsies.

The expression of DAZL1 in the ovary of the human female fetus

OBJECTIVE

To determine whether DAZL1 is expressed in human fetal ovarian tissue.

DESIGN

The presence of DAZL1 expression was determined by reverse transcriptase polymerase chain reaction (RT-PCR).

SETTING

Academic tertiary care medical center and research unit of university.

PATIENT(S)

Five female abortuses between the 19th and 22nd week of gestational age.

INTERVENTION(S)

Fetal ovarian tissues were collected immediately after the cessation of the heart beat.

MAIN OUTCOME MEASURE(S)

The product of RT-PCR.

RESULT(S)

DAZL1 expression was detected in all five samples.

CONCLUSION(S)

DAZL1 is not only expressed in human testes but also in ovaries. It may play a role in germ cell survival and gonad development in both sexes.

Polygenic influence on plasma homocysteine: association of two prevalent mutations, the 844ins68 of cystathionine beta-synthase and A(2756)G of methionine synthase, with lowered plasma homocysteine levels

A moderately elevated plasma total homocysteine (tHcy), whether measured during fasting or post-methionine load (PML), is increasingly being recognized as a risk factor for coronary artery diseases (CAD). However, etiologies for moderately elevated plasma tHcy, particularly with regard to the role of genetic influence on plasma tHcy levels, are still not well understood. In the current investigation, we studied 1025 individuals with respect to the effect of the 68-bp insertion (844ins68 variant) of the cystathionine beta-synthase (CBS) gene, the A(2756)G transition of the B(12)-dependent methionine synthase (MS) gene and the C(677)T transition of the methylenetetrahydrofolate reductase (MTHFR) gene on fasting and 4 h PML tHcy. Of these individuals, 153 (14.9%) were heterozygous for the 68-bp insertion, 329 (32.1%) were heterozygous for the G(2756) allele and 122 (11.9%) were homozygous for the C(677)T transition. Individuals heterozygous for the insertion had significantly lower PML increase in tHcy concentrations, while individuals homozygous for the A(2756)G transition had significantly lower fasting tHcy levels. A 2-way ANOVA showed that there was no interaction between the 844ins68 and the A(2756)G transition for either fasting tHcy or PML increase in tHcy, confirming the fact that the effect of these two genotypes on plasma tHcy levels are additive. The effects are opposite but additive with the C(677)50% of all individuals in this study carried polymorphic traits, which predisposed them to either higher or lower plasma tHcy concentrations, thus providing new evidence of the importance of genetic influences as determinants of tHcy levels.

Influence of polyvinylpyrrolidone on the outcome of intracytoplasmic sperm injection

OBJECTIVE

To assess the effectiveness of a procedure for intracytoplasmic sperm injection (ICSI) modified so as not to use polyvinylpyrrolidone (PVP) and to examine clinical outcome.

STUDY DESIGN

Seventy-seven cycles of ICSI were performed over a one-year period. PVP was used for sperm immobilization in 39 of these cycles and was eliminated from the other 38 cycles. Difference in fertilization rate, cleavage rate, parthenogenetic activity, clinical pregnancy rate, ongoing pregnancy rate and grading of preembryos between the two groups was compared.

RESULTS

The non-PVP group had a higher fertilization rate (57.63% vs. 84.43%, P < .001) and better preembryo quality (chi 2 = 6.80, P = .009) than the PVP group. There was no significant difference in cleavage rate, parthenogenetic activity, clinical pregnancy rate and ongoing pregnancy rate between the two groups.

CONCLUSION

Performing ICSI without PVP may improve the fertilization rate and preembryo grading. However, further study with a larger cohort is necessary to determine whether the modified procedure can increase the pregnancy rate.

Relationship of the human cumulus-free oocyte maturational profile with in vitro outcome parameters after intracytoplasmic sperm injection

PURPOSE

We investigated whether the human oocyte maturational profile at the removal of cumulus/corona cells affects the fertilization rate and subsequent embryo quality after intracytoplasmic sperm injection.

METHODS

A total of 1011 oocytes from 150 cycles was included in this retrospective analysis. Cumulus-free oocytes that were in prophase or metaphase I of meiosis at the removal of cumulus/corona cells were incubated in vitro until they reached metaphase II (in vitro-matured oocytes) and were then immediately injected with a single spermatozoa. Oocytes that were in metaphase II at the removal of cumulus/corona cells (MII oocytes) received sperm injection after 3-4 hr of preinjection incubation.

RESULTS

The fertilization rate of the MII oocytes was significantly higher than that of in vitro-matured oocytes (81 vs 62%; P < 0.001). The cleavage rates were similar in the two groups (MII oocytes, 94%; in vitro-matured oocytes, 91%). However, MII oocytes had significantly higher percentages of good-quality embryos (grade 1-3 embryos, 87 vs 58%, P < 0.001) and embryos with high cumulative embryo scores (score 10-32 embryos, 62 vs 33%, P < 0.001). The mean cumulative embryo score of MII oocytes after fertilization was also higher than that of in vitro-matured oocytes (12.1 +/- 3.8 vs 8.8 +/- 3.4; P = 0.014).

CONCLUSIONS

MII oocytes that extruded the first polar body at the removal of cumulus/corona cells had better fertilization rates and embryo morphology than in vitro-matured oocytes that extruded the first polar body following the removal of cumulus/corona cells and in vitro culture.

Relation between plasma homocysteine concentration, the 844ins68 variant of the cystathionine beta-synthase gene, and pyridoxal-5'-phosphate concentration

A moderately elevated plasma total homocysteine (tHcy), whether measured during fasting or post-methionine load (PML), is recognized as a risk factor for coronary artery diseases (CAD). Cystathionine beta-synthase (CBS), a key enzyme in the transsulfuration pathway, is important for the metabolism of homocysteine. In recent years, a relatively prevalent mutation, the 844ins68 (68-bp insertion), was found to be carried by about 12% of the general population. In the current investigation, we studied 741 individuals with respect to the effect of the 68-bp insertion of the CBS gene on fasting and PML tHcy, and also determined the level of pyridoxal-5'-phosphate (vitamin B(6)), a cofactor of the CBS enzyme. Our results showed that the mean fasting and PML increase in tHcy levels were lower in individuals carrying the 844ins68 variant compared to those without the insertion; although only the difference in PML increase in tHcy reached statistical significance (P = 0.02). When these individuals were divided into two groups based on vitamin B(6) concentration, the PML increase in tHcy was significantly lower in individuals heterozygous for the insertion compared to those without the insertion only in the group of individuals whose vitamin B(6) concentrations were below the sample median (38.0 nmol/L). We speculate that the 68-bp insertion is associated with somewhat higher levels of CBS enzyme activity, and that the effect of this becomes more pronounced in the presence of relatively low concentrations of pyridoxal-5'-phosphate, a cofactor of the CBS enzyme.

Detection of azoospermic factor genes in Chinese men with azoospermia or severe oligozoospermia

PURPOSE

We investigated the prevalence of deletions in the azoospermic factor (AZF) region of chromosome Yq11 in Chinese men with infertility due to idiopathic azoospermia or severe oligozoospermia. The DAZ gene cluster was also examined for mutations.

METHODS

Sixty-eight men with azoospermia or severe oligozoospermia taking part in an intracytoplasmic sperm injection program were recruited. Four loci specific for AZFa, AZFb, and AZFc were amplified from genomic DNA via polymerase chain reaction to determine whether deletions were present in the AZF region. Direct DNA sequencing of amplified products was also performed to look for mutations or polymorphism from exon 2 to exon 6 of the DAZ gene cluster.

RESULTS

Six (9%) of the 68 patients had AZF deletions. None had mutations in exons 2 to 6 of DAZ.

CONCLUSIONS

The prevalence of AZF deletions in our study was similar to those in Western reports, as was the lack of DAZ mutations.

Genetic causes of mild hyperhomocysteinemia in patients with premature occlusive coronary artery diseases

Elevated plasma homocysteine is increasingly being recognized as a risk factor for coronary artery disease (CAD). Although there is general agreement on the importance of micronutrients and genetic predisposition to elevated plasma homocysteine, the exact influence of the known prevalent mutations in genes which regulate homocysteine metabolism is not clear. We studied 376 cases of individuals with premature CAD with respect to their fasting and post-methionine load (PML) total homocysteine (tHcy) concentrations. We also determined the presence or absence of the T833C and G919A mutations of the cystathionine-beta-synthase (CBS) gene, the C677T mutation of the methylene tetrahydrofolate reductase (MTHFR) gene, and the A2756G transition of the B12 dependent methionine synthase (MS) gene. Our objectives were therefore both to confirm the relationship of plasma homocysteine with premature CAD and to examine the importance of genetic influence on both fasting and PML homocysteine. Approximately 32% of the CAD patients had fasting hyperhomocysteinemia and 16% had PML hyperhomocysteinemia. Of these, 8.5% had both forms of hyperhomocysteinemia (combined hyperhomocysteinemia). The T133C mutation in the CBS gene and the thermolabile C677T mutation in the MTHFR gene seem to play an important role in the subset of individuals with combined hyperhomocysteinemia. The A2756G transition in the MS gene is not associated with elevated plasma tHcy. Many cases (47%) of hyperhomocysteinemia are not associated with micronutrient deficiencies, impaired renal function, and/or currently known genetic mutations. Further work is needed to study whether unknown mutations, particularly those residing in the intronic sequences of the genes involved in homocysteine metabolism, other environmental factors, or interaction of gene, nutrient, and environmental factors may be the cause of currently unexplained cases of mild hyperhomocysteinemia.

Characterization of mutations in the cystathionine beta-synthase gene in Irish patients with homocystinuria

We used single-strand conformational polymorphism and nucleotide sequencing to characterize defective cystathionine beta-synthase gene alleles in 18 independent Irish patients with homocystinuria. Six mutations were detected, three of which have been reported previously and three of which were novel. The novel mutations include T302C (L101P), C684G (N228K), and G1063C (A354P). Of the three, only T302C (L101P) was somewhat prevalent, being found in 3 of 37 independent alleles.