Embracing polygenicity: a review of methods and tools for psychiatric genetics research.

The availability of genome-wide genetic data on hundreds of thousands of people has led to an equally rapid growth in methodologies available to analyse these data. While the motivation for undertaking genome-wide association studies (GWAS) is identification of genetic markers associated with complex traits, once generated these data can be used for many other analyses. GWAS have demonstrated that complex traits exhibit a highly polygenic genetic architecture, often with shared genetic risk factors across traits. New methods to analyse data from GWAS are increasingly being used to address a diverse set of questions about the aetiology of complex traits and diseases, including psychiatric disorders. Here, we give an overview of some of these methods and present examples of how they have contributed to our understanding of psychiatric disorders. We consider: (i) estimation of the extent of genetic influence on traits, (ii) uncovering of shared genetic control between traits, (iii) predictions of genetic risk for individuals, (iv) uncovering of causal relationships between traits, (v) identifying causal single-nucleotide polymorphisms and genes or (vi) the detection of genetic heterogeneity. This classification helps organise the large number of recently developed methods, although some could be placed in more than one category. While some methods require GWAS data on individual people, others simply use GWAS summary statistics data, allowing novel well-powered analyses to be conducted at a low computational burden.

Major histocompatibility complex-linked social signalling affects female fertility.

Genes of the major histocompatibility complex (MHC) have been shown to influence social signalling and mate preferences in many species, including humans. First observations suggest that MHC signalling may also affect female fertility. To test this hypothesis, we exposed 191 female horses (Equus caballus) to either an MHC-similar or an MHC-dissimilar stimulus male around the time of ovulation and conception. A within-subject experimental design controlled for non-MHC-linked male characteristics, and instrumental insemination with semen of other males (n = 106) controlled for potential confounding effects of semen or embryo characteristics. We found that females were more likely to become pregnant if exposed to an MHC-dissimilar than to an MHC-similar male, while overall genetic distance to the stimulus males (based on microsatellite markers on 20 chromosomes) had no effect. Our results demonstrate that early pregnancy failures can be due to maternal life-history decisions (cryptic female choice) influenced by MHC-linked social signalling.

EigenGWAS: finding loci under selection through genome-wide association studies of eigenvectors in structured populations.

We develop a novel approach to identify regions of the genome underlying population genetic differentiation in any genetic data where the underlying population structure is unknown, or where the interest is assessing divergence along a gradient. By combining the statistical framework for genome-wide association studies (GWASs) with eigenvector decomposition (EigenGWAS), which is commonly used in population genetics to characterize the structure of genetic data, loci under selection can be identified without a requirement for discrete populations. We show through theory and simulation that our approach can identify regions under selection along gradients of ancestry, and in real data we confirm this by demonstrating LCT to be under selection between HapMap CEU-TSI cohorts, and we then validate this selection signal across European countries in the POPRES samples. HERC2 was also found to be differentiated between both the CEU-TSI cohort and within the POPRES sample, reflecting the likely anthropological differences in skin and hair colour between northern and southern European populations. Controlling for population stratification is of great importance in any quantitative genetic study and our approach also provides a simple, fast and accurate way of predicting principal components in independent samples. With ever increasing sample sizes across many fields, this approach is likely to be greatly utilized to gain individual-level eigenvectors avoiding the computational challenges associated with conducting singular value decomposition in large data sets. We have developed freely available software, Genetic Analysis Repository (GEAR), to facilitate the application of the methods.

Lateral gain is impaired in macular degeneration and can be targeted to restore vision in mice.

Macular degeneration is a leading cause of blindness. Treatments to rescue vision are currently limited. Here, we study how loss of central vision affects lateral feedback to spared areas of the human retina. We identify a cone-driven gain control mechanism that reduces visual function beyond the atrophic area in macular degeneration. This finding provides an insight into the negative effects of geographic atrophy on vision. Therefore, we develop a strategy to restore this feedback mechanism, through activation of laterally projecting cells. This results in improved vision in Cnga3-/- mice, which lack cone function, as well as a mouse model of geographic atrophy. Our work shows that a loss of lateral gain control contributes to the vision deficit in macular degeneration. Furthermore, in mouse models we show that lateral feedback can be harnessed to improve vision following retinal degeneration.

Orbital socket contracture: a complication of inflammatory orbital disease in patients with Wegener's granulomatosis.

AIM: To describe the clinical characteristics of orbital socket contracture in patients with Wegener's granulomatosis (WG). METHODS: A retrospective cohort study The medical records of 256 patients with WG examined at the National Institutes of Health from 1967 to 2004 were reviewed to identify patients with orbital socket contracture. Details of the orbital disease including Hertel exophthalmometry readings, radiological findings, and results of eye examinations were recorded. Orbital socket contracture was defined as orbital inflammation with proptosis followed by the development of enophthalmos and radiographic evidence of residual fibrotic changes in the orbit. To examine for risk factors in the development of a contracted orbit, patients with orbital socket contracture were compared to patients without contracture with respect to multiple variables including history of orbital surgery, orbital disease severity, and major organ system involvement. The main outcome measures were the clinical characteristics of orbital socket contracture associated with inflammatory orbital disease in patients with WG. RESULTS: Inflammatory orbital disease occurred in 34 of 256 (13%) patients and detailed clinical data on 18 patients were available and examined. Orbital socket contracture occurred during the clinical course in six patients; the features included restrictive ophthalmopathy (five), chronic orbital pain (three), and ischaemic optic nerve disease (two) resulting in blindness (no light perception) in one patient. The orbital socket contracture occurred within 3 months of treatment with immunosuppressive medications for inflammatory orbital disease in five patients and was not responsive to immunosuppressive medications. The median degree of enophthalmos in the contracted orbit compared with the fellow eye was 2.8 mm (range 1.5-3.5 mm) by Hertel exophthalmometry. There were no risk factors that predicted development of orbital socket contracture. CONCLUSIONS: In six patients with WG and active inflammatory orbital disease, orbital socket contracture occurred during the treatment course with systemic immunosuppressive medications. The orbital socket contracture, presumably caused by orbital fibrosis, led to enophthalmos, restrictive ophthalmopathy, chronic orbital pain, and optic nerve disease and was not responsive to immunosuppressive therapy. Orbital socket contracture has not been previously reported as a complication of inflammatory orbital disease associated with WG and was an important cause of visual morbidity in our cohort of patients.

The quality of life of patients with newly diagnosed M1 prostate cancer: experience with EORTC clinical trial 30853.

This study was undertaken to evaluate the quality of life (QoL) of previously untreated patients with M1 prostate cancer before and during androgen-suppressive treatment. Assessment of QoL was included as an optimal component of EORTC protocol 30853, a phase III trial comparing LH-RH (luteinising hormone-releasing hormone) analogue combined with a non-steroidal anti-androgen versus orchiectomy in patients with M1 prostate cancer. At pretreatment and during the follow-up period, patients were asked to complete a questionnaire assessing their physical and psychosocial functioning, and their symptom levels. Physicians rated the patients' performance status, pain, urological symptoms and erectile function. Due to its optional nature, only a minority of the patients in the trial were recruited for the QoL investigation. 63 patients completed a pretreatment questionnaire, of whom 49 completed a second questionnaire at least once during the initial 15 month follow-up period. While statistically significant correlations were observed between patients' and physicians' ratings of physical functioning and pain, these were of only a moderate magnitude (r = 0.43 and 0.30, respectively). No significant association was observed between physicians' and patients' ratings of micturation problems or of erectile function. Before treatment, fatigue, pain and decreased social role and sexual functioning were the problems most frequently reported by patients. With an average of approximately 1 year follow-up, statistically significant improvements were observed in patients' self-reported urological symptoms and metastatic pain. No significant changes were noted for the other QoL domains assessed. The results of this study confirm earlier findings that physicians' ratings may not reflect accurately the functional health and symptom experience of their patients. Patient-based QoL questionnaires offer the most direct means of evaluating the subjective morbidity associated with prostate cancer and its treatment. To increase participation and compliance rates in future studies, it is recommended that QoL assessment be made mandatory in those clinical trials in which QoL is considered to be an important study endpoint.

The protein composition of the ocular zonules.

Bovine and human zonules were found to be composed of noncollagenous acidic glycoprotein with a high cysteine content, double that previously reported. In reduced zonular fractions the most prominent peptide had a molecular weight (MW) of approximately 70,000. Lesser quantities of 170,000, 50,000, and 35,000 dalton peptides were also present and a variable number of lower MW bands, depending upon the degree of reduction and denaturation. A fraction of bovine zonules soluble in low ionic strength buffers contained primarily a peptide of approximately 50,000 daltons, often present as a doublet. Amino acid and hexosamine content of these two fractions was consistent with the presence of at least two different glycoconjugates, one a proteoglycan. Carbohydrate analysis of whole zonules suggested that these glycoconjugates include a sialofucose-containing glycoprotein and a lesser quantity of xylose-containing proteoglycan. The amino acid profile and peptide content of the zonules resembled that of elastic tissue microfibrils, increasing further the possibility of a close relationship between these two fibrils.

Effects of tamoxifen on the binding and metabolism of testosterone by human prostatic tissue and plasma in vitro.

The in-vitro metabolism of testosterone in benign and malignant prostatic tissue was examined and distinct quantitative differences between the two types of specimens were observed. The major metabolite of testosterone in the hyperplastic prostate was 5 alpha-dihydrotestosterone and a high 3 alpha(beta)-hydroxysteroid dehydrogenase activity was also detected. In the malignant tissue, 5 alpha-reductase activity was considerably reduced and there was little or no androstanediol formed; the 17 beta-dehydrogenase activity was, however, higher than in the benign tissue. The decrease in 5 alpha-reductase was always followed by a compensatory change in the 3 alpha(beta)-hydroxysteroid dehydrogenase of the malignant prostate. The present study revealed that the ratio of the mean activities of 5 alpha-reductase to 3 alpha(beta)-hydroxysteroid dehydrogenase in the two types of specimen always remained a constant. Although the antioestrogen, tamoxifen, induced an inhibitory effect on the activities of 5 alpha-reductase and 17 beta-hydroxysteroid dehydrogenase in the gland, the present investigation also suggested that tamoxifen stimulated the activity of 3 alpha(3 beta)-hydroxysteroid dehydrogenase. In blood, the action of tamoxifen appeared to be confined to the displacement of androgens from the binding sites on the sex hormone binding globulin.

Topical corticosteroid therapy for cicatricial conjunctivitis associated with chronic graft-versus-host disease.

A retrospective chart review was performed on seven patients treated with topical ocular corticosteroid therapy for progressive cicatricial conjunctivitis associated with chronic graft-versus-host disease (GVHD) following hematopoietic stem cell transplantation. A clinical grading criteria for conjunctival GVHD based on the degree of cicatrization was developed and patients graded prior to therapy. During the treatment course, the dose and frequency of topical corticosteroids and clinical outcomes were recorded. A complete response was defined as a complete resolution of the conjunctival hyperemia with either total resolution of the conjunctival fibrovascularization or presence of inactive conjunctival scarring. Prednisolone acetate 1% eye drops were used in a total of eight courses of therapy in seven patients. A complete response was documented in all seven patients with a total treatment duration of 7 weeks (median, range: 3-16 weeks). Additional studies are required to determine the long-term safety and efficacy of topical corticosteroids for cicatricial conjunctivitis associated with ocular GVHD in the context of a randomized, prospective clinical trial.

Energy dispersive x-ray analysis of the cornea. Application to paraffin sections of normal and diseased corneas.

The distribution of chemical elements in the normal human cornea was studied by energy dispersive x-ray analysis and scanning electron microscopy of routinely prepared paraffin sections. Calcium, phosphorus, and sulfur were consistently present in quantities above background and varied in concentration regionally. Analysis of fresh-frozen tissue, an approximation of the in vivo state, gave a similar elemental profile to paraffin sections, except for the loss of diffusable electrolytes in the latter. After fixation, S was the most abundant element and was highest in Descemet's membrane. Corneas with granular, lattice, macular, and Fuchs' endothelial dystrophies, band keratopathy, and spheroidal degeneration were also examined. Characteristic patterns of abnormal S and Ca distribution were found in each of the dystrophies. The relative proportions of Ca, P, and S gave diagnostic profiles for distinguishing band keratopathy and spheroidal degeneration.

Lens capsule abnormalities in Alport's syndrome.

The ultrastructure of the glomerular basement membrane in Alport's syndrome is well known and characteristic of this disease, but the anterior lenticonus that frequently occurs in this syndrome has not been similarly studied. An anterior lens capsule from a 30-year-old patient with lenticonus who had Alport's syndrome was obtained at capsulectomy and found to be one third the normal thickness centrally and to be more fibrillar than usual. There were large numbers of partial capsular dehiscences containing fibrillar material and vacuoles. Cellular debris and more recent ruptures of lens epithelial cell membranes underlaid the breaks. The anterior capsule is clearly fragile in this disease, forming the basis for the progressive lenticonus and anterior polar cataract. These abnormalities correlate well with a defect in the type IV collagen molecule, as has been recently reported in Alport's syndrome.

Pharmacokinetics and toxicity of intravitreal chemotherapy for primary intraocular lymphoma.

OBJECTIVE: To investigate the pharmacokinetics and toxicity of intravitreal chemotherapeutic agents in the rabbit eye for the potential treatment of primary intraocular lymphoma and other intraocular malignancies. METHODS: The ocular pharmacokinetics of intravitreal methotrexate sodium (400 microg) was studied in 10 New Zealand white rabbits, and a single-compartment, first-order elimination model was used to calculate the drug half-life. With the use of these data, a treatment schedule using serial injections of intravitreal methotrexate and single injections of fluorouracil and dexamethasone sodium phosphate was developed. This schedule was studied in 4 New Zealand white rabbits to explore the combined toxicity of these agents. RESULTS: Methotrexate vitreous levels, following a 400-microg intravitreal injection, remained therapeutic (>0.5 microM) in the rabbit eye for 48 to 72 hours. Intravitreal methotrexate, combined with fluorouracil and dexamethasone, showed no evidence of drug toxicity as determined by electroretinography and histopathologic examination. CONCLUSIONS: A treatment schedule for primary intraocular lymphoma consisting of methotrexate intravitreal injections every 48 to 72 hours provides therapeutic drug concentrations in the vitreous and, in combination with fluorouracil and dexamethasone, appears to be safe in the rabbit eye. CLINICAL RELEVANCE: Although responsive to conventional chemotherapy or radiotherapy, recurrence of ocular involvement with primary central nervous system lymphoma occurs in more than 50% of treated cases. Anecdotal reports of the use of intravitreal chemotherapy for primary intraocular lymphoma have been encouraging. However, animal data on the pharmacokinetics and toxicity of combined intravitreal agents for the treatment of this disease are lacking.

Frosted branch angiitis in a child with HIV infection.

PURPOSE: In adults with human immunodeficiency virus (HIV) infection, frosted branch angiitis is commonly associated with cytomegalovirus retinitis and responds to anti-cytomegalovirus therapy. We describe the first pediatric case of HIV-associated frosted branch angiitis. METHODS: Case report. RESULTS: A 7-year-old HIV-infected male with frosted branch angiitis was refractory to induction doses of intravenous ganciclovir and foscarnet over a 2-month period. Although cytomegalovirus antigenemia resolved, the angiitis only improved after subsequent treatment with systemic corticosteroids. CONCLUSION: Frosted branch angiitis in this patient was not attributed to cytomegalovirus. The pathogenesis of HIV-associated frosted branch angiitis may differ between children and adults.

High-dose intravitreal ganciclovir and foscarnet for cytomegalovirus retinitis.

PURPOSE: To describe the chronic use of high doses of intravitreal ganciclovir, in combination with foscarnet, for the treatment of cytomegalovirus retinitis. METHODS: A 31-year-old man with human immunodeficiency virus (HIV) infection and unilateral active cytomegalovirus retinitis was treated with escalating intravitreal injections of ganciclovir (up to 3.0 mg twice a week) in combination with foscarnet (up to 2.4 mg twice a week) over the course of approximately 1 year. RESULTS: Complete regression of the retinitis was obtained with high doses of intravitreal ganciclovir and foscarnet. Visual acuity in the affected eye remained 20/20 throughout the course of therapy. No ganciclovir retinal toxicity was identified. CONCLUSION: High doses of intravitreal ganciclovir in combination with foscarnet can be well tolerated and may be required to successfully control cytomegalovirus retinitis in some patients.

Immune-recovery uveitis in patients with cytomegalovirus retinitis taking highly active antiretroviral therapy.

PURPOSE: To investigate the clinical features associated with immune recovery in human immunodeficiency virus (HIV)-infected patients with cytomegalovirus retinitis who are taking highly active antiretroviral therapy. METHODS: Sixteen patients were evaluated prospectively at the National Eye Institute, Bethesda, Maryland. Evaluation included a medical history and a complete ophthalmologic examination. The examination included best-corrected visual acuity score measured by means of logarithmic charts, slit-lamp biomicroscopy, dilated retinal examination, retinal photography, and fluorescein angiography. Immune-recovery uveitis was defined as the ocular inflammation associated with clinical immune recovery in patients taking potent antiretroviral regimens. The ophthalmic characteristics of immune-recovery uveitis were identified, and their effect on visual acuity was statistically analyzed. RESULTS: The mean CD4+ T-lymphocyte count for the 16 patients taking highly active antiretroviral therapy at the time of evaluation was 393 cells/microl (range, 97-1,338 cells/microl). Immune-recovery uveitis was characterized by vitreitis and optic disk and macular edema. Clinically important complications of immune-recovery uveitis included cataract and epiretinal membrane formation. The visual acuity scores were significantly worse in the 23 eyes with cytomegalovirus retinitis (mean, 67.2 letters, 20/50) than in the nine eyes without cytomegalovirus retinitis (mean, 89.8 letters, 20/16) (P <.001). Regression analysis showed that a lower visual acuity score was associated with the presence of moderate to severe macular edema on fluorescein angiography and vitreous haze (P < or =. 001). CONCLUSIONS: Immune-recovery uveitis is an important cause of visual morbidity in HIV-infected patients with cytomegalovirus retinitis in the era of highly active antiretroviral therapy. Although immune recovery associated with highly active antiretroviral therapy has allowed some patients to discontinue specific anticytomegalovirus therapy, the rejuvenated immune response can be associated with sight-threatening inflammation.

Keratitis caused by Candida glabrata in a patient with chronic granulomatous disease.

PURPOSE: To report an unusual ocular presentation of Candida glabrata in a patient with chronic granulomatous disease. METHODS: Interventional case report. A 15-year-old boy with chronic granulomatous disease presented with bilateral limbal infiltrates. He had been receiving broad-spectrum systemic antibiotics for recurrent liver abscesses. The keratitis did not respond to antibiotics and did not resolve after a course of topical steroids. RESULTS: Corneal cultures revealed Candida glabrata. The same species was simultaneously isolated from the surgical drainage of the liver abscesses. The ocular and hepatic findings resolved on intravenous amphotericin B. CONCLUSION: Candida glabrata has recently emerged as an important nosocomial pathogen. It may present as a limbal keratitis in the setting of systemic infection.

The evaluation of a new enzyme immunoassay for the measurement of prostatic acid phosphatase.

An enzyme immunoassay for prostatic acid phosphatase (PAP) has been assessed. An upper limit normal is set at 1.8 microgram/1. There is a very low incidence of raised levels in chronic diseases or cancers other than those of the prostate. Patients with well-controlled prostatic cancer have levels less than 1.8 microgram/1 and show little variation about their own mean. PAP can rise exponentially with a doubling time of 1-5 months. This assay is unlikely to increase the detection of asymptomatic prostatic cancer as 66% of T0-2NXM0 cases had PAP less than 1.8 microgram/1. The main advantages over routine enzyme assays are its sensitivity and accuracy in the lower range.

Anterior uveitis associated with intravenous cidofovir use in patients with cytomegalovirus retinitis.

AIM: Intravenous cidofovir is used to treat cytomegalovirus (CMV) retinitis, and has been reported to cause anterior uveitis. Relations were sought between this complication and patient characteristics that might help predict its occurrence. METHODS: 17 patients with AIDS and CMV retinitis who were treated with intravenous cidofovir were identified, and the following data collected in a retrospective chart review: demographic characteristics, duration of CMV retinitis, retinal lesion characteristics, dose and duration of cidofovir therapy, tests of renal function, CD4+ T lymphocyte counts, visual acuity, intraocular pressure, iris colour, history of diabetes mellitus, and use of concomitant medications. Case-control analyses were performed to determine risk factors for developing cidofovir associated uveitis. RESULTS: Anterior uveitis characterised by pain, ciliary injection, and decreased visual acuity occurred in 10 patients (59%). Median interval to development of uveitis was 11 doses of cidofovir. Symptoms developed 4.4 (SD 2.5) days (median 3.5) after an infusion of cidofovir. Patients who developed uveitis had a significantly greater rise in CD4+ T lymphocyte count while receiving cidofovir (68.4 (75.7) x10(6)/l versus 5.0 (0.6) x10(6)/l, (p = 0.04)). By stepwise linear regression, this factor accounted for 33% (p = 0.03) of the effect of developing uveitis. Mean follow up time, intraocular pressure decline during cidofovir therapy, serum creatinine and urine protein concentrations, and rates of protease inhibitor use were not significantly different between patients who developed uveitis and those who did not. Uveitis responded to topical corticosteroids and cycloplegia. CONCLUSION: Anterior uveitis in patients receiving intravenous cidofovir therapy may be related to improving immune function. The uveitis responds to treatment and may not preclude continuation of cidofovir.

An LH-RH analogue (Zoladex) in the management of carcinoma of the prostate: a preliminary report comparing daily subcutaneous injections with monthly depot injections.

The luteinizing hormone releasing hormone, Zoladex, has been used in three centres, Pontefract, Antwerp and Mistelbach, to treat carcinoma of the prostate. An initial protocol using a soluble daily injection has been followed by a second study employing a monthly administered depot preparation. After an initial stimulation it has been shown that both daily and monthly injections reduce plasma testosterone to castrate levels. Circulating luteinizing hormone levels are also initially stimulated and then suppressed. Treatment toxicity has been minimal and in these short term studies reduction of acid phosphatase and subjective and objective tumour responses have been similar to those expected from effective hormonal therapy of prostatic cancer.

Choroidal neovascular membrane inhibition in a laser treated rat model with intraocular sustained release triamcinolone acetonide microimplants.

AIM: To determine if intravitreal microimplants containing triamcinolone acetonide (TAAC) inhibit experimental fibrovascular proliferation (FVP) induced by laser trauma in a rat as a model of choroidal neovascular membranes (CNVMs). METHODS: 20 anaesthetised male Brown Norway rats received a series of eight krypton red laser lesions per eye (647 nm, 0.05 s, 50 micro m, 150 mW). Three types of sterilised TAAC microimplant designs were evaluated: implant A consisting of 8.62% TAAC/20% polyvinyl alcohol (PVA) matrix (by dry weight); implant B consisting of 3.62% TAAC/20% PVA matrix; and implant C consisting of a dual 8.62% TAAC/20% PVA matrix design combined with a central core (0.5 mm) of compressed TAAC to extend the implant release time. For each animal studied, one eye received one of the three aforementioned TAAC implant designs, while the fellow eye received a control implant consisting of PVA but without TAAC. The animals were sacrificed at day 35 and ocular tissues were processed for histological analysis. Serial histological specimens were methodically assessed in a masked fashion to analyse each laser lesion for the presence or absence of FVP; maximum FVP thickness for each lesion was measured from the choriocapillaris. RESULTS: All three types of TAAC implants inhibited FVP relative to controls in a statistically significant fashion. In the eyes that received implant A (n = 8), the mean thickness of the recovered lesions (n = 36) measured 32 (SD 22) micro m, compared to 52 (30) micro m (p <0.005) for the recovered lesions (n = 40) from the fellow control eyes. In the eyes that received implant B (n = 6), the mean thickness of the recovered lesions (n = 31) measured 28 (15) micro m, compared to 50 (29) micro m (p <0.001) for the lesions (n = 19) recovered from the fellow control eyes. In the eyes that received implant C (n = 6), the mean thickness of the recovered lesions (n = 21) measured 39 (24) micro m, compared to 65 (30) micro m (p <0.001) for the lesions (n = 39) recovered from the fellow control eyes. CONCLUSIONS: All three of the tested TAAC microimplant designs produced potent inhibition of FVP in a rat model of CNVMs. There were no differences in inhibition of FVP between the three different types of implants evaluated. This study provides evidence that: (1) corroborates previous investigations that propose TAAC as a potential treatment for CNVMs in humans, and (2) demonstrates TAAC can be effectively delivered via long acting sustained release intraocular microimplants. It should be noted, however, that the FVP observed in this rat laser trauma may not reflect the CNVM observed in human with exudative age related macular degeneration (AMD).