Analysis of selected anticonvulsants by high performance liquid chromatography-tandem mass spectrometry

A method for the analysis of the basic antiepileptic compounds felbamate, lamotrigine, carbamazepine, carbamazepine-10,11-epoxide, gabapentin, pregabalin, levetiracetam, and oxcarbazepine monohydroxy derivative (oxcarb MHD) in human plasma is described. This protocol incorporates a simplified sample preparation step followed by quantitative high performance chromatography-tandem mass spectrometry detection of commonly prescribed and monitored anticonvulsant drugs. Since polytherapy is common in epilepsy patients, use of a multiconstituent assay can improve laboratory efficiency and reduce required analytical time.

Caveolae compartmentalise β2-adrenoceptor signals by curtailing cAMP production and maintaining phosphatase activity in the sarcoplasmic reticulum of the adult ventricular myocyte

Inotropy and lusitropy in the ventricular myocyte can be efficiently induced by activation of β1-, but not β2-, adrenoceptors (ARs). Compartmentation of β2-AR-derived cAMP-dependent signalling underlies this functional discrepancy. Here we investigate the mechanism by which caveolae (specialised sarcolemmal invaginations rich in cholesterol and caveolin-3) contribute to compartmentation in the adult rat ventricular myocyte. Selective activation of β2-ARs (with zinterol/CGP20712A) produced little contractile response in control cells but pronounced inotropic and lusitropic responses in cells treated with the cholesterol-depleting agent methyl-β-cyclodextrin (MBCD). This was not linked to modulation of L-type Ca²⁺ current, but instead to a discrete PKA-mediated phosphorylation of phospholamban at Ser¹⁶. Application of a cell-permeable inhibitor of caveolin-3 scaffolding interactions mimicked the effect of MBCD on phosphorylated phospholamban (pPLB) during β2-AR stimulation, consistent with MBCD acting via caveolae. Biosensor experiments revealed β2-AR mobilisation of cAMP in PKA II signalling domains of intact cells only after MBCD treatment, providing a real-time demonstration of cAMP freed from caveolar constraint. Other proteins have roles in compartmentation, so the effects of phosphodiesterase (PDE), protein phosphatase (PP) and phosphoinositide-3-kinase (PI3K) inhibitors on pPLB and contraction were compared in control and MBCD treated cells. PP inhibition alone was conspicuous in showing robust de-compartmentation of β2-AR-derived signalling in control cells and a comparatively diminutive effect after cholesterol depletion. Collating all evidence, we promote the novel concept that caveolae limit β2-AR-cAMP signalling by providing a platform that not only attenuates production of cAMP but also prevents inhibitory modulation of PPs at the sarcoplasmic reticulum. This article is part of a Special Issue entitled “Local Signaling in Myocytes”.

Are patient characteristics associated with the accuracy of hysterosalpingography in diagnosing tubal pathology? An individual patient data meta-analysis

BACKGROUND

Conventional meta-analysis has estimated the sensitivity and specificity of hysterosalpingography (HSG) to be 65% and 83%. The impact of patient characteristics on the accuracy of HSG is unknown. The aim of this study was to assess by individual patient data meta-analysis whether the accuracy of HSG is associated with different patient characteristics.

METHODS

We approached authors of primary studies reporting on the accuracy of HSG using findings at laparoscopy as the reference. We assessed whether patient characteristics such as female age, duration of subfertility and a clinical history without risk factors for tubal pathology were associated with the accuracy of HSG, using a random intercept logistic regression model.

RESULTS

We acquired data of seven primary studies containing data of 4521 women. Pooled sensitivity and specificity of HSG were 53% and 87% for any tubal pathology and 46% and 95% for bilateral tubal pathology. In women without risk factors, the sensitivity of HSG was 38% for any tubal pathology, compared with 61% in women with risk factors (P = 0.005). For bilateral tubal pathology, these rates were 13% versus 47% (P = 0.01). For bilateral tubal pathology, the sensitivity of HSG decreased with age [factor 0.93 per year (P = 0.05)]. The specificity of HSG was very stable across all subgroups.

CONCLUSIONS

The accuracy of HSG in detecting tubal pathology was similar in all subgroups, except for women without risk factors in whom sensitivity was lower, possibly due to false-positive results at laparoscopy. HSG is a useful tubal patency screening test for all infertile couples.

Harvestman (Opiliones) fauna associated with Maine lowbush blueberry fields in the major production areas of Washington and Hancock counties

Over a period of 19 yr, the harvestman (Opiliones) community associated with the lowbush blueberry agro-ecosystem in Maine was studied. Eight species representing five genera, four subfamilies, and two families of harvestmen belonging to the suborder Eupnoi were collected. The harvestman community was dominated by two introduced, synanthropic species: Phalangium opilio in all but 1 yr (that year dominated by Rilaena triangularis). Rilaena was recorded for the first time from eastern North America. Relative abundance of harvestman adults increases throughout the season and the temporal pattern of trap capture does not refute speculated life cycles of the harvestmen being univoltine with overwintering eggs. Some blueberry management practices were found to affect trap capture. We did find that on average (with opposite results 1 yr) trap captures are greater in pruned fields than in fruit-bearing fields. Organic fields were found to have higher relative abundance of harvestmen than conventionally managed fields. Conventionally managed fields with reduced-risk insecticides showed no difference in harvestmen relative abundance compared with those conventionally managed fields using the older more persistent organophosphate insecticides. Insecticide trials with common insecticides used in blueberry insect pest management showed that the organophosphate insecticide, phosmet, and the pyrethroid insecticide, esfenvalerate, were detrimental to P. opilio adults when exposed to leaf residues, whereas the reduced-risk insecticide, spinosad, showed no negative effects compared with nonsprayed foliage.

Unstable familial transmissions of Huntington disease alleles with 27-35 CAG repeats (intermediate alleles)

There are inconsistent reports regarding the likelihood of repeat instability for alleles with 27-35 CAG repeats in the Huntington disease (HD) gene. We have examined the intergenerational stability of such intermediate alleles in 51 families from the University of British Columbia's DNA and Tissue Bank for Huntington Disease Research (UBC-HD Databank). A total of 181 transmissions were identified, with 30% (n = 54/181) of the alleles being unstable upon transmission. The unstable transmissions included both expansions (n = 37) and contractions (n = 17) of CAG size. Of the expanded alleles, 68% (n = 25/37) expanded into the HD range (>36 CAG). Therefore, 14% (n = 25/181) of the 27-35 CAG allele transmissions examined expanded into the disease-associated range resulting in a new mutation for HD. Significantly, of these new mutations, 40% (n = 10/25) originated from an allele with 35 CAG repeats with CAG repeat expansions ranging from +1 CAG to +23 CAG. The proportion of new mutations in the UBC-HD Databank is consistent with the most recent new mutation rate for HD, estimated to be at least 10%. The observed difference in the stability of HD intermediate allele transmissions in this data set and in other studies may be a reflection of a small sample size. Alternately, these inconsistencies may indicate an underlying difference in genetic factors which influence repeat instability between the different populations examined. Additional studies determining the frequency and magnitude of repeat instability in this CAG repeat range and factors that influence instability are urgently needed. Until we understand the clinical implications of HD alleles with 27-35 CAG repeats and establish reliable risks of instability, we should exercise caution when translating these results to the clinic.

Genetic variation in healthy oldest-old

Individuals who live to 85 and beyond without developing major age-related diseases may achieve this, in part, by lacking disease susceptibility factors, or by possessing resistance factors that enhance their ability to avoid disease and prolong lifespan. Healthy aging is a complex phenotype likely to be affected by both genetic and environmental factors. We sequenced 24 candidate healthy aging genes in DNA samples from 47 healthy individuals aged eighty-five years or older (the 'oldest-old'), to characterize genetic variation that is present in this exceptional group. These healthy seniors were never diagnosed with cancer, cardiovascular disease, pulmonary disease, diabetes, or Alzheimer disease. We re-sequenced all exons, intron-exon boundaries and selected conserved non-coding sequences of candidate genes involved in aging-related processes, including dietary restriction (PPARG, PPARGC1A, SIRT1, SIRT3, UCP2, UCP3), metabolism (IGF1R, APOB, SCD), autophagy (BECN1, FRAP1), stem cell activation (NOTCH1, DLL1), tumor suppression (TP53, CDKN2A, ING1), DNA methylation (TRDMT1, DNMT3A, DNMT3B) Progeria syndromes (LMNA, ZMPSTE24, KL) and stress response (CRYAB, HSPB2). We detected 935 variants, including 848 single nucleotide polymorphisms (SNPs) and 87 insertion or deletions; 41% (385) were not recorded in dbSNP. This study is the first to present a comprehensive analysis of genetic variation in aging-related candidate genes in healthy oldest-old. These variants and especially our novel polymorphisms are valuable resources to test for genetic association in models of disease susceptibility or resistance. In addition, we propose an innovative tagSNP selection strategy that combines variants identified through gene re-sequencing- and HapMap-derived SNPs.

CAG expansion in the Huntington disease gene is associated with a specific and targetable predisposing haplogroup

Huntington disease (HD) is an autosomal-dominant disorder that results from >or=36 CAG repeats in the HD gene (HTT). Approximately 10% of patients inherit a chromosome that underwent CAG expansion from an unaffected parent with <36 CAG repeats. This study is a comprehensive analysis of genetic diversity in HTT and reveals that HD patients of European origin (n = 65) have a significant enrichment (95%) of a specific set of 22 tagging single nucleotide polymorphisms (SNPs) that constitute a single haplogroup. The disease association of many SNPs is much stronger than any previously reported polymorphism and was confirmed in a replication cohort (n = 203). Importantly, the same haplogroup is also significantly enriched (83%) in individuals with 27-35 CAG repeats (intermediate alleles, n = 66), who are unaffected by the disease, but have increased CAG tract sizes relative to the general population (n = 116). These data support a stepwise model for CAG expansion into the affected range (>or=36 CAG) and identifies specific haplogroup variants in the general population associated with this instability. The specific variants at risk for CAG expansion are not present in the general population in China, Japan, and Nigeria where the prevalence of HD is much lower. The current data argue that cis-elements have a major predisposing influence on CAG instability in HTT. The strong association between specific SNP alleles and CAG expansion also provides an opportunity of personalized therapeutics in HD where the clinical development of only a small number of allele-specific targets may be sufficient to treat up to 88% of the HD patient population.

What is the most valid comparison treatment in trials of intrauterine insemination, timed or uninfluenced intercourse? A systematic review and meta-analysis of indirect evidence

BACKGROUND

Timed intercourse (TI), which is the usual control treatment in trials of intrauterine insemination (IUI), is not a typical coital activity and could impair fertility. This review summarizes the trials of IUI of male partner's prepared semen among subfertile couples according to whether the control group had TI or expectant management.

METHODS

A search of relevant databases and bibliographies until February 2008 yielded 150 citations of which 31 were potentially relevant and 11 met all criteria. The total estimates of the differences in pregnancy rates per couple were calculated with weights equal to the inverse variance. The primary analysis was a categorical meta-analysis by the type of control treatment (TI or expectant management).

RESULTS

In 11 trials with 13 comparisons of IUI and intercourse among 1329 couples with subfertility, the average difference in pregnancy rate between IUI and controls was 6.1% in trials with TI and 3.9% in trials with expectant management, as the control. The adjusted indirect estimate of the difference between the types of control groups was 2.8% (95% CI -6.3, 10.7). The difference by type of control treatment was not significant, neither in the 11 most relevant trials (P = 0.82), nor in a broader group of 19 trials and 2512 patients (P = 0.20).

CONCLUSIONS

The additional benefit accruing to IUI, where TI is the control, is not significant, but it is consistent with the possibility that pregnancy may be less likely in TI controls than in expectant management controls.

Mechanism of mRNA destabilization by the glmS ribozyme

An array of highly structured domains that function as metabolite-responsive genetic switches has been found to reside within noncoding regions of certain bacterial mRNAs. In response to intracellular fluctuations of their target metabolite ligands, these RNA elements exert control over transcription termination or translation initiation. However, for a particular RNA class within the 5' untranslated region (UTR) of the glmS gene, binding of glucosamine-6-phosphate stimulates autocatalytic site-specific cleavage near the 5' of the transcript in vitro, resulting in products with 2'-3' cyclic phosphate and 5' hydroxyl termini. The sequence corresponding to this unique natural ribozyme has been subjected to biochemical and structural scrutiny; however, the mechanism by which self-cleavage imparts control over gene expression has yet to be examined. We demonstrate herein that metabolite-induced self-cleavage specifically targets the downstream transcript for intracellular degradation. This degradation pathway relies on action of RNase J1, a widespread ribonuclease that has been proposed to be a functional homolog to the well-studied Escherichia coli RNase E protein. Whereas RNase E only poorly degrades RNA transcripts containing a 5' hydroxyl group, RNase J1 specifically degrades such transcripts in vivo. These findings elucidate key features of the mechanism for genetic control by a natural ribozyme and suggest that there may be fundamental biochemical differences in RNA degradation machinery between E. coli and other bacteria.

The contribution of HIV fitness to the evolution pattern of reverse transcriptase inhibitor resistance

All currently recommended anti-retroviral therapy protocols employ reverse transcriptase inhibitors (RTIs). However, mutations within the reverse transcriptase (RT) domain can lead to resistance to these agents and treatment failure. The contribution of the fitness of drug-resistant species to the evolution of RTI resistance has not been elucidated despite its potential implications for therapeutic strategies. In this study we utilized a competitive fitness assay to assess the relative fitness of 13 drug-resistant HIV-1 mutants in the presence and absence of inhibitor. Among these mutants were thymidine analog mutations (TAMs) such as 41L/210W/215Y and 67N/70R/219Q, as well as single mutants such as 103N and 181C that confer high-level resistance to non-nucleoside reverse transcriptase inhibitors (NNRTIs) such as nevirapine. These studies revealed that 67N/70R and 67N/70R/219Q were fitter than the 70R progenitor species, and the acquisition of 41L by 215Y substantially increased its fitness in the absence of drug. We also observed that 215Y was more fit than 70R and 67N/70R, and that 41L/215Y and 41L/210W/215Y were the most-fit species in the presence of zidovudine. Moreover, 103N was fitter than 181C without nevirapine but less fit with nevirapine. From these studies we conclude that viral fitness contributes substantially to the evolutionary pattern of TAMs suggesting that, as for protease inhibitor resistance, mutations can act in primary (increasing resistance) and secondary (increasing fitness) capacities. We also surmise that drug resistance and fitness are competing forces underlying the emergence of nevirapine resistant mutants 103N and 181C.

Karyotypic analysis of adult pluripotent stem cells

Three categories of precursor cells have been identified in postnatal mammals: tissue-committed progenitor cells, germ layer lineage-committed stem cells and lineage-uncommitted pluripotent stem cells. Progenitor cells are the immediate precursors of differentiated tissues. Germ layer lineage stem cells can be induced to form multiple cell types belonging to their respective ectodermal, mesodermal, and endodermal embryological lineages. Pluripotent stem cells will form somatic cell types from all three primary germ layer lineages. Progenitor cells demonstrate a finite life span before replicative senescence and cell death occur. Both germ layer lineage stem cells and pluripotent stem cells are telomerase positive and display extensive capabilities for self-renewal. Stem cells which undergo such extensive replication have the potential for undergoing mutations that may subsequently alter cellular functions. Gross mutations in the genome may be visualized as chromosomal aneuploidy and/or chromosomes that appear aberrant. This study was designed to determine whether any gross genomic mutations occurred within the adult pluripotent stem cells. Karyotypic analysis was performed using pluripotent stem cells purified from adult male rats using established procedures. Giemsa Banding was used in conjunction with light microscopy to visualize metaphase chromosome spreads. To date over 800 metaphase spreads have been analyzed. We found that the metaphase spreads averaged 42 chromosomes and concluded that these pluripotent stem cells isolated from adult rats have a normal karyotype.

Two new prediction rules for spontaneous pregnancy leading to live birth among subfertile couples, based on the synthesis of three previous models

BACKGROUND

Several models have been published for the prediction of spontaneous pregnancy among subfertile patients. The aim of this study was to broaden the empirical basis for these predictions by making a synthesis of three previously published models.

METHODS

We used the original data from the studies of Eimers et al. (1994), Collins et al. (1995) and Snick et al. (1997) on couples consulting for various forms of subfertility. We developed a so-called three-sample synthesis model for predicting spontaneous conception leading to live birth within 1 year after intake based on the three data sets. The predictors used are duration of subfertility, women's age, primary or secondary infertility, percentage of motile sperm, and whether the couple was referred by a general practitioner or by a gynaecologist (referral status). The performance of this model was assessed according to a 'jack-knife' analysis. Because the post-coital test (PCT) was not assessed in one of the samples, a synthesis model including the PCT was based on two samples only.

RESULTS

The ability of the synthesis models to distinguish between women who became pregnant and those who did not was comparable to the ability of the one-sample models when applied in the other samples. The reliability of the predictions by the three-sample synthesis model was somewhat better. Predictions improved considerably by including the PCT.

CONCLUSIONS

The synthesis models performed better and had a broader empirical basis than the original models. They are therefore better suitable for application in other centres.

A comparison of ovulation suppression and ovulation stimulation in the treatment of endometriosis-associated infertility

This study compares ovulation stimulation or suppression with the pregnancy rate among infertile couples with endometriosis. The design is a nonrandomized, prospective, multicentered cohort analytic study. Two hundred and ninety-seven couples with laparoscopy-proven endometriosis were analyzed: 68 received no therapy, 42 received clomiphene and 74 received danazol. Forty patients (22%) conceived and pregnancy rates were similar in each treatment group. The relative likelihood of pregnancy associated with clomiphene was 2.9 (95% confidence limits 1.2-7.1); the relative likelihood of pregnancy with danazol was 1.02 (95% confidence limits 0.5-2.3). This study suggests that pregnancy rates during clomiphene treatment could be superior to expectant therapy, while pregnancy rate after danazol is similar to no treatment.

Unexplained infertility: a review of diagnosis, prognosis, treatment efficacy and management

The dilemma of unexplained infertility posed by Southam in 1960 remains today: despite advances in the diagnostic assessment of infertility, many couples still have no explanation for their infertility. Even the most sophisticated evaluation of semen, ovulation and genital tract competence cannot reveal all of the possible defects in the complex process leading to conception. Because it arises from these shortcomings in our knowledge of fertilization and from our inability to utilize all of the current knowledge, unexplained infertility is a challenge for both biological and clinical research. This paper attempts to summarize some clinical issues in the management of unexplained infertility: the prevalence of the disorder, problems in the definition and possible explanations for the existence of this diagnostic category. It reviews outcome-based clinical publications as a guide to decision-making on what diagnostic tests to use, provides a summary of the untreated prognosis and evaluates study results that may serve as a basis for treatment decisions in this puzzling diagnostic category of infertility.

Control of gene expression by a natural metabolite-responsive ribozyme

Most biological catalysts are made of protein; however, eight classes of natural ribozymes have been discovered that catalyse fundamental biochemical reactions. The central functions of ribozymes in modern organisms support the hypothesis that life passed through an 'RNA world' before the emergence of proteins and DNA. We have identified a new class of ribozymes that cleaves the messenger RNA of the glmS gene in Gram-positive bacteria. The ribozyme is activated by glucosamine-6-phosphate (GlcN6P), which is the metabolic product of the GlmS enzyme. Additional data indicate that the ribozyme serves as a metabolite-responsive genetic switch that represses the glmS gene in response to rising GlcN6P concentrations. These findings demonstrate that ribozyme switches may have functioned as metabolite sensors in primitive organisms, and further suggest that modern cells retain some of these ancient genetic control systems.

Competitive fitness of nevirapine-resistant human immunodeficiency virus type 1 mutants

Determining the fitness of drug-resistant human immunodeficiency virus type 1 (HIV-1) strains is necessary for the development of population-based studies of resistance patterns. For this purpose, we have developed a reproducible, systematic assay to determine the competitive fitness of HIV-1 drug-resistant mutants. To demonstrate the applicability of this assay, we tested the fitness of the five most common nevirapine-resistant mutants (103N, 106A, 181C, 188C, and 190A), with mutations in HIV-1 reverse transcriptase (RT), singly and in combination (for a total of 31 variants) in a defined HIV-1 background. For these experiments, the 27 RT variants that produced viable virus were cocultured with wild-type virus without nevirapine. The ratios of the viral species were determined over time by utilization of a quantitative real-time RT-PCR-based assay. These experiments revealed that all of the viable variants were less fit than the wild type and demonstrated that the order of relative fitness of the single mutants tested was as follows: 103N > 181C > 190A > 188C > 106A. This order correlated with the commonality of these mutants as a result of nevirapine monotherapy. These investigations also revealed that, on average, the double mutants were less fit than the single mutants and the triple mutants were less fit than the double mutants. However, the fitness of the single and double mutants was often not predictive of the fitness of the derivative triple mutants, suggesting the presence of complex interactions between the closely aligned residues that confer nevirapine resistance. This complexity was also evident from the observation that all three of the replication-competent quadruple mutants were fitter than most of the triple mutants, and in some cases, even the double mutants. Our data suggest that, in many cases, viral fitness is the determining factor in the evolution of nevirapine-resistant mutants in vivo, that interactions between the residues that confer nevirapine resistance are complex, and that these interactions substantially affect reverse transcriptase structure and/or function.

Surgery or embolisation for varicocele in subfertile men

BACKGROUND

A varicocele is a meshwork of distended blood vessels in the scrotum, usually left-sided, due to dilatation of the spermatic vein. Although the concept that varicocele causes, and varicocelectomy cures, male subfertility has been around for almost fifty years, the mechanisms by which varicocele would affect fertility have not yet been satisfactorily explained, and neither have the mechanisms by which varicocelectomy would restore fertility. Furthermore, it has been questioned whether a causal relation exists at all between the distension of the pampiniform plexus and impairment of fertility.

OBJECTIVES

To evaluate the effect of varicocele treatment on pregnancy rate in subfertile couples.

SEARCH STRATEGY

We searched the Cochrane Menstrual Disorders and Subfertility Group trials register (searched 12 Sept 2003), the Cochrane Central Register of Controlled Trials (The Cochrane Library Issue 1, 2004), MEDLINE (January 1966 to May 2004), EMBASE (January 1985 to May 2004) and reference lists of articles. In addition, we hand searched 22 specialist journals in the field from their first issue until 2004. We also checked cross references, references from review articles, and contacted researchers in the field.

SELECTION CRITERIA

RCTs were included if they were relevant to the clinical question posed, if they reported pregnancy rates as an outcome measure, and if they reported data in treated (surgical ligation or radiological embolization of the internal spermatic vein) and untreated groups.

DATA COLLECTION AND ANALYSIS

Nine studies met the inclusion criteria for this review. One was an extension of a previously published study (Nieschlag 1995/1998), which left eight studies for analysis (Nilsson 1979; Breznik 1993; Madgar 1995; Yamamoto 1996; Nieschlag 1995/1998; Grasso 2000; Unal 2001; Krause 2002). All eight only included men from couples with subfertility problems, one (Madgar 1995) excluded men with sperm counts <5 mill/mL, one (Krause 2002) men with sperm counts <2 mill/mL and/or progressive motility <10%, two trials involving clinical varicoceles included some men with normal semen analysis (Nilsson 1979; Breznik 1993). Three studies (Yamamoto 1996; Grasso 2000; Unal 2001) specifically addressed only men with subclinical varicoceles. Two authors independently screened potentially relevant trials. Any differences of opinion were resolved by consensus (none occurred for this review). Studies were excluded from meta-analysis if they made comparisons other than those specified above.

MAIN RESULTS

The combined Peto odds ratio (OR) of the eight studies is 1.10 (95%CI 0.73 to 1.68), indicating no benefit of varicocele treatment over expectant management in subfertility couples in whom varicocele in the man is the only abnormal finding.

REVIEWERS' CONCLUSIONS

There is no evidence that treatment of varicocele in men from couples with otherwise unexplained subfertility improves the couple's chance of conception.

Current perspectives on oral contraceptive use

Oral contraceptives are one of the most highly effective forms of contraception and provide many short- and long-term noncontraceptive health benefits. They control menstrual cycle irregularities, such as breakthrough bleeding and amenorrhea, and are effective in treating dysfunctional uterine bleeding. In addition, for decades after oral contraceptive use is discontinued they are associated with substantial decreases in the risk of ovarian cancer (up to 80%) and of endometrial cancer (40%-50%), and nearly eliminate benign functional ovarian cysts. Long-term oral contraceptive use confers protection against benign breast disease and colorectal cancer, may help prevent rheumatoid arthritis, decreases ectopic pregnancy and hospitalizations for pelvic inflammatory disease, and helps preserve bone mineral density to reduce risk of fractures. Large bodies of evidence from extensive research have clarified the perceived association of oral contraceptive use with cardiovascular disease and with breast cancer. Findings indicate that there is no increased risk of myocardial infarction or stroke associated with oral contraceptive use in healthy, nonsmoking, normotensive women. Although there is a 3- to 4-fold increased risk of venous thromboembolism with current oral contraceptive use, the absolute risk is very small and is half that associated with pregnancy. Women of all reproductive ages, including perimenopausal women, can realize many health benefits through oral contraceptive use, including improved health status later in life.

Current perspectives on benefits and risks of hormone replacement therapy

Hormone replacement therapy with estrogen alone or with added progestin relieves menopausal symptoms and physical changes associated with depleted endogenous estrogen levels. Estrogen replacement has also demonstrated a clear benefit in the prevention of osteoporosis. Hormone replacement therapy with added progestin maintains spinal bone density, protects against postmenopausal hip fractures, and provides these benefits even when therapy is started after age 60. More recently, additional benefits have emerged. Current estrogen and hormone replacement therapy users have a 34% reduction in the risk of colorectal cancer and a 20% to 60% reduction in the risk of Alzheimer's disease. Until recently, the body of evidence indicated that hormone replacement therapy with estrogen only reduced cardiovascular disease risk by 40% to 50% in healthy patients; whether the findings of 3 ongoing trials will change this conclusion is pending availability of the final results. The many benefits of estrogen and hormone replacement therapy must be weighed against a slight increase in the risk of breast cancer diagnosis with use for 5 or more years, but which disappears following cessation of therapy. Overall, estrogen and hormone replacement therapy improves the quality of life and increases life expectancy for most menopausal women.

Cost-effectiveness of hysterosalpingography, laparoscopy, and Chlamydia antibody testing in subfertile couples

OBJECTIVE

To evaluate the cost-effectiveness analysis of hysterosalpingography (HSG), laparoscopy, and Chlamydia antibody testing (CAT) in subfertile couples.

DESIGN

Cost-effectiveness analysis.

SETTING

Decision analytic framework.

PATIENT(S)

Data of >2,000 subfertile couples in the Canadian Infertility Treatment Evaluation Study. Results of CA-125 measurement and CAT were simulated from baseline characteristics.

INTERVENTION(S)

Expectant management was considered to be the reference strategy (strategy 1). In strategy 2 and 3, IVF was offered either immediately or after 2.5 years. In strategy 4, the decision to offer or delay treatment was based on the couple's chance of spontaneous conception. Nine strategies incorporated combinations of CAT, CA-125 measurement, HSG, and laparoscopy.

MAIN OUTCOME MEASURE(S)

Expected live birth rates, expected number of IVF cycles, and expected total costs.

RESULT(S)

The strategy starting with CAT was the most cost-effective in couples whose 3-year chance of conception was >14%, whereas the strategy starting with HSG was the most cost-effective in couples with worse fertility prospects.

CONCLUSION(S)

The diagnostic work-up to detect tubal pathology in subfertile couples should start with CAT in couples with relatively good fertility prospects and immediate HSG in couples with relatively poor fertility prospects.

Surgery or embolisation for varicocele in subfertile men

BACKGROUND

A varicocele is an, almost exclusively left-sided, varicosity of the pampiniform plexus of the spermatic cord, forming a tangle of distended blood vessels in the scrotum. Although the concept that varicocele causes male subfertility and therefore varicocelectomy cures male subfertility has been around for almost fifty years now, the mechanisms by which varicocele would affect fertility have not yet been satisfactorily explained, and neither have the mechanisms by which varicocelectomy would resolve subfertility. Furthermore, it has been questioned whether a causal relation exists at all between the distension of the pampiniform plexus and impairment of fertility.

OBJECTIVES

To evaluate the effect of varicocele treatment on pregnancy rate in subfertile couples.

SEARCH STRATEGY

Relevant trials were identified in the Cochrane Menstrual Disorders and Subfertility Group's specialised register of controlled trials. A MEDLINE search, using the group's search strategy, was performed for the period 1966-2000. Also, hand searching was performed of 22 specialist journals in the field from their first issue till 2000. Cross references and references from review articles were checked.

SELECTION CRITERIA

RCTs were included if they were relevant to the clinical question posed, if they reported pregnancy rates as an outcome measure, and if they reported data in treated (surgical ligation or radiological embolization of the internal spermatic vein) and untreated groups.

DATA COLLECTION AND ANALYSIS

Six studies met the inclusion criteria for this review. One (Nieschlag 1995/1998) was an extension of a previously published study (Nieschlag 1995/1998), which left five studies for analysis (Nilsson 1979; Breznik 1993; Madgar 1995; Yamamoto 1996; Nieschlag 1995/1998). The results of a WHO megatrial are awaited but as yet are unavailable. The WHO data will be added if and when they will have become available. All five only included men from couples with subfertility problems, one (Madgar 1995) excluded men with sperm counts <5 mill/mL, three (Nilsson 1979; Breznik 1993; Yamamoto 1996) also included men with normal semen analysis. One study (Yamamoto 1996) specifically addressed only men with subclinical varicoceles as diagnosed by thermography. Potentially relevant trials were screened independently by two authors (JE and JC). Any differences of opinion were resolved by consensus meeting (none occurred for this review). Studies were excluded from meta-analysis if they made comparisons other than those specified above.

MAIN RESULTS

One trial (Madgar 1995) reported a statistically significant improvement in pregnancy rate following high ligation of the left spermatic vein. None of the other four studies showed individually a significant effect on pregnancy rates of varicocele treatment over no-treatment (Nilsson 1979; Breznik 1993; Yamamoto 1996), or over counseling only (Nieschlag 1995/1998). The combined RR (Relative Risk; random effects method) of the five studies is 1.06 (95%CI 0.57-1.94), the Peto OR (Odds Ratio) is 1.15 (95%CI 0.73-1.83).

REVIEWER'S CONCLUSIONS

Insufficient evidence exists that treatment of varicocele in men from couples with otherwise unexplained subfertility does improve the couple's spontaneous pregnancy chances.