Correction: Genetic risk for schizophrenia and psychosis in Alzheimer disease.

A number of collaborators were not acknowledged for their contribution to this published article. The acknowledgements that were missing in this published article can now be found in the associated correction.

Genetic risk for schizophrenia and psychosis in Alzheimer disease.

Psychotic symptoms, defined as the occurrence of delusions or hallucinations, are frequent in Alzheimer disease (AD), affecting ~40 to 60% of individuals with AD (AD with psychosis (AD+P)). In comparison with AD subjects without psychosis, AD+P subjects have more rapid cognitive decline and poor outcomes. Prior studies have estimated the heritability of psychosis in AD at 61%, but the underlying genetic sources of this risk are not known. We evaluated a Discovery Cohort of 2876 AD subjects with (N=1761) or without psychosis (N=1115). All subjects were genotyped using a custom genotyping array designed to evaluate single-nucleotide polymorphisms (SNPs) with evidence of genetic association with AD+P and include SNPs affecting or putatively affecting risk for schizophrenia and AD. Results were replicated in an independent cohort of 2194 AD subjects with (N=734) or without psychosis (N=1460). We found that AD+P is associated with polygenic risk for a set of novel loci and inversely associated with polygenic risk for schizophrenia. Among the biologic pathways identified by the associations of schizophrenia SNPs with AD+P are endosomal trafficking, autophagy and calcium channel signaling. To the best of our knowledge, these findings provide the first clear demonstration that AD+P is associated with common genetic variation. In addition, they provide an unbiased link between polygenic risk for schizophrenia and a lower risk of psychosis in AD. This provides an opportunity to leverage progress made in identifying the biologic effects of schizophrenia alleles to identify novel mechanisms protecting against more rapid cognitive decline and psychosis risk in AD.

Bayesian model selection: analysis of a survival model with a surviving fraction.

We describe a methodology for model comparison in a Bayesian framework as applied to survival with a surviving fraction. This is illustrated using a case study of a randomized and controlled clinical trial investigating time until recurrence of depression. Posterior distributions are simulated using Metropolis-within-Gibbs Markov chain methods. Models reflecting the effects of covariates on the log odds of being in the surviving fraction, the log of the hazard rate, as well as both and neither are compared. Bayes factors for comparing the models are obtained by using the bridge sampling method of calculating normalizing constants.

Transmission/disequilibrium test meets measured haplotype analysis: family-based association analysis guided by evolution of haplotypes.

Family data teamed with the transmission/disequilibrium test (TDT), which simultaneously evaluates linkage and association, is a powerful means of detecting disease-liability alleles. To increase the information provided by the test, various researchers have proposed TDT-based methods for haplotype transmission. Haplotypes indeed produce more-definitive transmissions than do the alleles comprising them, and this tends to increase power. However, the larger number of haplotypes, relative to alleles at individual loci, tends to decrease power, because of the additional degrees of freedom required for the test. An optimal strategy would focus the test on particular haplotypes or groups of haplotypes. In this report we develop such an approach by combining the theory of TDT with that of measured haplotype analysis (MHA). MHA uses the evolutionary relationships among haplotypes to produce a limited set of hypothesis tests and to increase the interpretability of these tests. The theory of our approach, called the "evolutionary tree" (ET)-TDT, is developed for two cases: when haplotype transmission is certain and when it is not. Simulations show the ET-TDT can be more powerful than other proposed methods under reasonable conditions. More importantly, our results show that, when multiple polymorphisms are found within the gene, the ET-TDT can be useful for determining which polymorphisms affect liability.

Transfer of cryopreserved-thawed pre-embryos in a cycle using exogenous steroids without prior gonadotrophin-releasing hormone agonist suppression yields favourable pregnancy results.

We have analysed the use of a programmed cycle of administration of exogenous steroids without prior suppression with a gonadotrophin-releasing hormone agonist (GnRHa) for the transfer of cryopreserved-thawed pre-embryos. From July 1992 to June 1994, 199 cycles (162 patients) were studied. Pre-embryos had been previously cryopreserved at the pronuclear stage using 1.5 M 1,2-propanediol as a cryoprotectant. Preparation of the endometrium was achieved in a step-up regime with transdermal oestradiol patches (0.1 to 0.4 mg). Progesterone in oil (50 mg i.m.) was started on cycle day 13. Pre-embryos were thawed on day 14 and transferred on day 15 after evidence of survival and cleavage. The mean (+/- SD) age of patients undergoing transfer was 35.4 +/- 4.3 years. The mean number of pre-embryos thawed was 4.7 +/- 1.8 with a mean of 3.3 +/- 1.4 pre-embryos being transferred. Eight of the cycles demonstrated follicular development >16 mm prior to thaw and transfer; however, these patients did not demonstrate a luteinizing hormone surge. Mean endometrial thickness on day 13 was 10.8 +/- 2.1 mm. Overall pregnancy rate was 29.2% (57/195). The ongoing or delivery rate was 16.1% (32/195). The rate of preclinical losses per transfer was 6.2% (12/195). Overall, the implantation rate was 6.2% (47/757). Thus, the use of a programmed cycle for cryopreserved embryo transfer yields favourable pregnancy outcome and offers practical advantages to patients. Prior suppression with a GnRHa is not necessary for endometrial preparation.

ACTH, beta-endorphin, substance P, and corticotrophin releasing hormone in plasma and follicular fluid in hormonally stimulated menstrual cycles for in-vitro fertilization in the human.

Changes in plasma concentrations of ACTH, beta-endorphin (beta-EP) and cortisol have been found to be associated during the human menstrual cycle. Changes in hypothalamic levels of gonadotrophin releasing hormone (GnRH), beta-EP and substance P (SP) have also been associated with the oestrous cycle in the rat. Therefore, an attempt was made to measure the activity of the corticotrophic axis and SP by measuring blood and follicular fluid concentrations of ACTH, beta-EP, SP and corticotrophin releasing hormone (CRH) during the hormonal ovarian stimulation phase for in-vitro fertilization (IVF), in a series of 19 patients. At the plasma level, there was no significant change over treatment days in ACTH (P = 0.1550), beta-EP (P = 0.1137), or SP concentrations (P = 0.5625). CRH was not detectable over treatment days. In addition, there was no significant change in neuropeptide over treatment days between those women who became pregnant and those who did not (P = 0.17 for all). In the follicular fluid, ACTH was not detectable, beta-EP concentration was three times higher than in the plasma, CRH was detectable, and SP concentration was similar to that of plasma. There was no apparent correlation, however, between beta-EP or SP concentrations in the plasma and follicular fluid from a given patient. In conclusion, the absence of changes in the activity of the corticotrophic axis during the hormonal ovarian stimulation suggests that there was no major stress component associated with the stimulation phase of IVF or the occurrence of a pregnancy.

Superior analytic characteristics of an immunometric assay for gonadotropins also provides useful clinical prediction of in vitro fertilization outcomes.

OBJECTIVE: To determine whether an analytically superior gonadotropin assay, the monoclonal, two-site immunometric assay, also provided superior prediction of clinical outcomes when compared with conventional RIA methodology. DESIGN: Methods comparison study. SETTING: Tertiary academic center. PATIENTS: One hundred fifty-seven consecutive IVF patients. INTERVENTION: Comparisons of FSH and LH levels on cycle day 3 were made using paired RIA and immunometric assay procedures. The ability of day 3 LH, FSH, and their ratio in predicting IVF performance was determined using regression analyses. RESULTS: The predictive ability of FSH as assayed by immunometric assay at least equaled that obtained by RIA for both peak E2 levels and the number of mature oocytes retrieved. CONCLUSION: Results from this study indicate that gonadotropin levels as measured by immunometric assay represent an effective clinical tool in predicting IVF outcomes that may prove superior to RIA.

Increase in androgen:estrogen ratio specifically during low-dose follicle-stimulating hormone therapy for polycystic ovary syndrome.

OBJECTIVES: To compare changes in serum androgens in women with polycystic ovary syndrome (PCOS) during ovulation induction with low-dose versus conventional urofollitropin. DESIGN: Prospective case-control study. SETTING: Tertiary-care reproductive medicine center. SUBJECTS: Thirty-three women with PCOS who failed to conceive with clomiphene citrate therapy. INTERVENTIONS: Urofollitropin (low-dose, 75 IU; conventional dose, 150 IU) was administered IM daily. Therapy was monitored by serum E2 and vaginal sonography. Hormone determinations were performed by immunoassay. MAIN OUTCOME MEASURES: Serum E2, androstenedione (A), T, and LH levels. RESULTS: On the day of hCG administration, patients treated with low-dose therapy exhibited significantly higher ratios of A to E2 (3.5 +/- 0.5 versus 2.2 +/- 0.3 [mean +/- SEM]) and T to E2 (1.5 +/- 0.3 versus 1.0 +/- 0.1) compared with conventional urofollitropin therapy. The number of follicles > or = 16 mm in diameter was significantly lower with low-dose therapy (2.7 +/- 0.6 versus 5.4 +/- 0.4). CONCLUSIONS: Although low-dose therapy was associated with a reduction in the number of recruited follicles, the increase in androgen to E2 associated with this therapy may adversely affect oocyte quality and may explain the relatively high miscarriage rate reported in PCOS patients with this therapy.

Activation of the hypothalamo-anterior pituitary corticotropin-releasing hormone, adrenocorticotropin hormone and beta-endorphin systems during the estradiol 17 beta-induced plasma LH surge in the ovariectomized monkey.

The present work describes time-dependent changes in the content of corticotropin-releasing hormone (CRH), adrenocorticotropin (ACTH), and beta-endorphin (beta-EP) in the hypothalamus (HT) and anterior pituitary (AP) and in the concentration of ACTH and beta-EP in the plasma during the 17 beta estradiol (E2) benzoate (E2B)-induced luteinizing hormone (LH) surge in ovariectomized cynomolgus monkeys. Monkeys were euthanized at 0, 30, 48, 72, and 96 hr post-E2B. HT and AP were rapidly dissected, extracted in 2 N acetic acid containing 1 mM phenylmethane sulfonyl fluoride at 4 degrees C, and centrifuged at 18,000g for 30 min. Peptide concentrations were measured in the supernatant by specific radioimmunoassays (RIAs). In the HT, there were significant (P < 0.05) decreases in ACTH and beta-EP content by 30 hr post-E2B and a significant (P < 0.05) decrease in HT CRH content 48 hr post-E2B. Thereafter, CRH, ACTH, and beta-EP content increased up to 72 hr post-E2B. In the AP, there was an almost linear decrease in the CRH content through 48 hr post-E2B followed by a marked 20-fold (P < 0.01) increase in the AP CRH content at 72 hr post-E2B, which corresponds to the time of the descending arm of the LH surge. The patterns of ACTH and beta-EP content were very similar in the AP, while that of CRH differed markedly. In contrast, in the HT CRH, ACTH, and beta-EP profiles were very similar. Significant (P < 0.05) increases in circulating levels of ACTH, beta-EP, and cortisol were evident at 30 hr (all 3 hormones), 48 hr (beta-EP and cortisol), and 72 hr (cortisol) post-E2B, which corresponds with the time of decreased hypothalamic content of CRH, ACTH, and beta-EP. These results suggest that there maybe a marked activation of the hypothalamo-anterior pituitary-adrenal axis during the negative and positive feedback phases of the E2B-induced LH surge in the ovariectomized monkey.

Impact of immunoglobulin isotype and sperm surface location of antisperm antibodies on fertilization in vitro in the human.

OBJECTIVE: To investigate the impact of immunoglobulin (Ig) isotypes and their location on the human sperm surface on fertilization in vitro. DESIGN: Restrospective review and analysis. SETTING: Reproductive endocrine division of a level 3 academic center. PATIENTS: Forty-eight couples (80 IVF cycles) with males showing positive antisperm antibodies on the sperm surface by immunobead test, treated by IVF at the Norfolk Program. MAIN OUTCOME MEASURE: Evaluation of total fertilization rate of preovulatory oocytes (metaphase II-metaphase I). RESULTS: Immunoglobulin G and IgA antibody levels have no significant correlation with total fertilization rate of preovulatory oocytes by logistic regression. Immunoglobulin M, present in 44% of the couples, had a strong correlation with fertilization. When IgA showed very high levels of binding (> 68%) and IgM binding was > 40%, the fertilization rate dropped significantly. A strong correlation between presence of antibodies and fertilization rate was seen when IgM was directed to the head or tail tip of the sperm. Immunoglobulin A induced a statistically significant reduction of fertilization only when it was present on the head. CONCLUSION: Two male antisperm Ig isotypes significantly impaired fertilization rates. Immunoglobulin A exerted its impact only when high level of binding was detected on the head. Immunoglobulin M, present in 44% of the males, was the Ig isotype that most significantly affected fertilization rates when localized both at the head and at the tail tip level.

Transfer of cryopreserved-thawed pre-embryos in a natural cycle or a programmed cycle with exogenous hormonal replacement yields similar pregnancy results.

OBJECTIVE: To examine the results of 7 years of thawed ET during natural or controlled cycles using exogenous steroids. DESIGN: Retrospective evaluation to compare implantation and pregnancy rates with two protocols for transfer of cryopreserved-thawed pre-embryos. SETTING: Tertiary care academic center. PATIENTS: From January 1987 to December 1993, 521 patients who were < 40 years of age underwent 628 thawed embryo transfers. MAIN OUTCOME MEASURE: Pregnancy and implantation rates per thawed embryo transfer cycle. RESULTS: A total 1,987 pre-embryos survived the thawing process and were used in 628 thaw-transfer cycles. Transfer was performed in a natural cycle 2 days after the LH peak or on day 17 of a programmed cycle using a GnRH-agonist and hormone replacement therapy protocol; 182 pregnancies were established (182/628; 29%). Similar pregnancy rates were seen in the natural cycle (112/398; 28%) and the programmed cycle (70/230; 30%). The implantation rates were similar in the two methods of transfer cycles (11.9% versus 10.3%, natural versus programmed cycle). There were no significant differences in clinical or ongoing pregnancy rates in a natural or programmed cycle, correcting for the number of cryopreserved-thawed pre-embryos transferred. Patient's age at the time of freezing and the number of cryopreserved-thawed pre-embryos transferred are more important determinants of pregnancy than the type of cycle in which transfer occurs. CONCLUSION: Transferring cryopreserved-thawed pre-embryos in a natural or programmed cycle yields similar pregnancy results.

Sperm morphology as diagnosed by strict criteria: probing the impact of teratozoospermia on fertilization rate and pregnancy outcome in a large in vitro fertilization population.

OBJECTIVE: To investigate the predictive value of sperm morphology assessed by strict criteria on IVF outcome. DESIGN: Retrospective analysis of all IVF cycles (January 1987 to December 1992). MAIN OUTCOME MEASURES: All patients were assigned to one of three groups based on sperm morphology: P-pattern (< 4% normal forms), G-pattern (4% to 14% normal forms), and N-pattern (> 14% normal forms). Morphology pattern was related to other semen characteristics and IVF outcome. RESULTS: Despite corrective measures at oocyte insemination, the fertilization rate was significantly different among the three morphology groups, P < G < N. N-pattern sperm produced a mean fertilization rate over 85% regardless of low motility or concentration. In a cohort study, P-pattern cycles produced a lower implantation rate and lower ongoing pregnancy rate, independent of the lower fertilization rate. CONCLUSIONS: Strict morphology is an excellent biomarker of sperm fertilizing capacity, independent of motility and concentration. P-pattern sperm may denote a poorer prognosis for establishing a pregnancy, even after a satisfactory fertilization rate is achieved.

The reduction of postoperative adhesions by two different barrier methods versus control in cynomolgus monkeys: a prospective, randomized, crossover study.

OBJECTIVES: To determine the effectiveness of two different surgical membranes in preventing postoperative adhesions as compared with control and to evaluate the benefit as compared with "second-look" adhesiolysis. DESIGN: A randomized, prospective, crossover study. SETTING: A colony of individually caged non-human primates, Department of Obstetrics and Gynecology, Eastern Virginia Medical School Norfolk, Virginia. INTERVENTIONS: Hysterotomy or adhesiolysis at the time of exploratory laparotomy, with subsequent scoring of adhesions based on area, vascularity, tenacity, and adhesion score. RESULTS: The combined crossover data reveal that both surgical barriers are superior in adhesion prevention to microsurgical technique alone. Expanded polytetrafluoroethylene (Gore-Tex Surgical Membrane; WL Gore and Associates, Flagstaff, AZ) was better than oxidized regenerated cellulose (Interceed; Johnson and Johnson Medical, Inc., Arlington, TX) with respect to adhesion area, tenacity, and vascularity, with a significant improvement in the total adhesion score. Second-look adhesiolysis resulted in significant adhesion reduction in the control group, making second-look adhesiolysis statistically similar to the use of either barrier alone (without subsequent adhesiolysis). Gore-Tex removal does not result in adhesion formation as determined by third-look surgery. CONCLUSIONS: Both Interceed and Gore-Tex show a reduction in the prevention of postsurgical adhesions after hysterotomy incisions, as compared with microsurgical technique alone. Second-look adhesiolysis is as effective as either barrier in the reduction of permanent pelvic adhesions.

Early follicular rise of serum progesterone concentration in response to a flare-up effect of gonadotrophin-releasing hormone agonist impairs follicular recruitment for in-vitro fertilization.

A retrospective study of 150 cycles of in-vitro fertilization (IVF) was undertaken to determine the impact of elevated serum progesterone in the early follicular phase of IVF cycles utilizing gonadotrophin-releasing hormone agonist (GnRHa) initiated in the follicular phase. A total of 127 patients identified as being at risk for poor response to stimulation were treated with a flare-up protocol of GnRHa combined with high dose follicle stimulating hormone (FSH). Patients were excluded for severe male factor requiring micromanipulation. Patients were stimulated with GnRHa beginning on cycle day 2, and high dose FSH beginning on cycle day 3. Some 85% of the cycles exhibited a rise of serum progesterone to a peak concentration of > 1.0 ng/ml (range, 1.2-4.2 ng/ml) during cycle days 2-6. When compared to cycles with no demonstrable progesterone rise, cycles with a rise were associated with a significantly decreased ovarian response: more ampoules of gonadotrophin were required (mean 26.8 versus 22.6, P < 0.05), lower peak oestradiol concentration was reached (mean 774 pg/ml versus 1030; P < 0.05), and fewer mature oocytes were harvested (mean 4.6 versus 7.5; P < 0.01). Among the different pregnancy outcomes (clinical pregnancy, no pregnancy, ongoing pregnancy, and miscarriage), there were no significant differences detected in the early follicular progesterone concentrations as measured by peak progesterone, progesterone area under the curve (days 2-6), and day of peak progesterone. The follicular phase initiation of GnRHa can result in significant elevations of serum progesterone in the early follicular phase, which may impair follicular recruitment and overall ovarian response.

Hypothalamo-anterior pituitary gonadotropin-releasing hormone and substance-P systems during the 17 beta-estradiol-induced plasma luteinizing hormone surge in the ovariectomized female monkey.

The present study examined the effects of 17 beta-estradiol benzoate (E2B) on the hypothalamic (HT) and anterior pituitary (AP) content of GnRH precursor (pro-GnRH-GAP), GnRH, GnRH-associated peptide (GAP), and substance-P (SP) during the various phases of the E2B-induced LH surge in cynomolgus monkeys. Changes in GnRH and GnRH-associated peptide (GAP) at both hypothalamic and AP levels were closely related at all times after E2B treatment. However, the pattern of change in the AP was very different from that in the HT. In the HT, pro-GnRH-GAP levels did not change significantly throughout the experimental period. In the AP, the pro-GnRH-GAP increased 48 h post-E2B treatment, the time of initiation of the LH surge. An 8-fold increase in AP GnRH occurred 30 h post-E2B treatment. There were no significant changes in the HT content of SP at any time after E2B treatment. However, there was a depletion of AP content by 48 h post-E2B, the time of the LH surge. These results demonstrate that E2 activates and deactivates in a coordinated manner the GnRH and SP systems of the HT-AP complex during initiation of the E2-induced LH surge. The observation that more significant changes occur in the AP than in the HT suggests that an important component of the E2 effect in inducing the LH surge may be directly at the AP level. This action involves changes in the contents of GnRH and SP in the AP.

Progesterone levels on the day of human chorionic gonadotropin administration in cycles with gonadotropin-releasing hormone agonist suppression are not predictive of pregnancy outcome.

In in vitro fertilization (IVF) cycles using gonadotropin-releasing hormone agonist (GnRH-a) suppression, we investigated whether an elevated progesterone (P) level on the day of human chorionic gonadotropin (hCG) administration indicates premature luteinization and is associated with a lower pregnancy rate. We retrospectively studied 101 patients treated with the GnRH-a leuprolide acetate, begun in the luteal phase of the prior menstrual cycle and continued until the day of hCG administration. On the day of hCG, 72 patients had P less than 0.9 ng/mL and 29 had less than or equal to 0.9 ng/mL. Patients in the high P group had a significantly greater estradiol level on the day of hCG. No significant difference in clinical pregnancy rates or ongoing pregnancy rates occurred between the low P and high P groups. We conclude that in IVF cycles pretreated with GnRH-a, P levels on the day of hCG are not predictive of conceiving in that cycle.

Abbott's fluorescence polarization immunoassay for cyclosporine and metabolites compared with the Sandoz "Sandimmune" RIA.

A new procedure for measuring cyclosporine in plasma has been introduced by Abbott Laboratories, involving their TDx instrumentation and fluorescence polarization immunoassay. Radioimmunoassay (RIA) and high-performance liquid chromatography are currently the conventional methods for measuring cyclosporine in plasma and whole blood. In an effort to find a method that will decrease the radioactive hazard, the reagent and supply cost, and the labor requirements associated with RIA procedures, we used specimens from transplantation patients to compare the Abbott assay with the Sandoz Sandimmune assay. We believe that the Abbott assay offers some advantages over the Sandimmune RIA procedure, providing a reliable but simpler and less hazardous technology.

Biopharmaceutical aspects of FK-506.

FK is a potent immunosuppressive agent. FK can be analyzed in biologic fluids by EIA. The oral absorption of FK is rapid but variable in dogs. After intramuscular administration, FK is slowly and continuously absorbed. FK is primarily eliminated by metabolism. Less than 1% of the administered dose is excreted in the bile or the urine. After chronic intramuscular administration FK inhibits drug metabolism. Monitoring of FK levels in plasma is essential for the proper interpretation of efficacy and toxicity studies.

Cyclosporine metabolism and pharmacokinetics following intravenous and oral administration in the dog.

The influence of assay method on single dose cyclosporine (CsA) pharmacokinetics was studied in nine dogs receiving either i.v. or oral CsA. Samples were drawn from hepatic, portal, and systemic veins at various times after the dose and CsA levels were determined by radioimmunoassay (RIA) and high-performance liquid chromatography (HPLC). Blood concentration-time data were analyzed by nonlinear least-squares regression, using two-compartment models. RIA/HPLC ratios for all samples were greater than one, and did not change significantly over time. The mean RIA/HPLC ratios for samples drawn from all three veins were higher after oral than i.v. doses of the drug (P less than 0.05). Area under the concentration-time curve (AUC) was higher and systemic clearance (CIs) lower than calculated on the basis of RIA results, regardless of the route of administration. AUC calculated for CsA metabolites (RIA-HPLC) was highest in the portal vein after an oral dose of CsA. Bioavailability was 20.4% and 27.0% when estimated using HPLC and RIA data, respectively. The mean CsA metabolite index (CMI), when calculated for hepatic, portal, or systemic vein, was greater when the drug was administered orally. The mean hepatic extraction ratio (HER) of the parent drug and for CsA metabolites was approximately 23% in i.v. and p.o. studies. These results suggest that the gastrointestinal tract may play a role in the metabolism of CsA when the drug is administered orally. In addition, if CsA metabolites not measured by HPLC have either toxic or immunosuppressive properties, the RIA assay may be more useful for monitoring patients.

Cyclosporine measurement in transplantation.

Use of cyclosporine is a major breakthrough in immunosuppressive therapy for organ transplantation. Critical to its success, however, is the availability of regular and frequent measurements of the blood levels of the drug. Radioimmunoassay and/or high-pressure liquid chromatography may be employed for this analysis. Radioimmunoassay measures the parent molecule together with its metabolites, whereas high-pressure liquid chromatography measures only the parent drug, which indicates that clinical and laboratory experience, as well as an understanding of methodology, are necessary for the interpretation of cyclosporine levels.