Sooty Mould on Hibiscus rosa‐sinensis Caused by Leptoxyphium kurandae is Associated with Extrafloral Nectaries

In August 2013, sooty mould was observed on Chinese hibiscus (Hibiscus rosa‐sinensis) in a propagation nursery in Seoul, Korea. The sooty mould initially developed at the junction between the leaf blade and leaf petiole and then dispersed along the vein on the abaxial surface. The fungal growth pattern on the plants was quite different from general sooty moulds growing on honeydew secreted by insects on the plants. On the basis of the morphological characteristics and phylogenetic analysis using the internal transcribed spacer rDNA, this fungus was identified as Leptoxyphium kurandae. A pathogenicity test was carried out to fulfil Koch's postulates. Through field observation and a pathogenicity test, we found an association between the sooty mould and extrafloral nectaries. To our knowledge, this is the first report of sooty mould caused by L. kurandae on the extrafloral nectaries of H. rosa‐sinensis.     

Competition with filamentous fungi and its implication for a gregarious lifestyle in insects living on ephemeral resources

Abstract. 1. Recent studies have demonstrated the existence of positive density dependence in the survival and development of Drosophila (the so‐called Allee effect); however the underlying mechanisms of such Allee effects have remained elusive. Competition with filamentous fungi have often been suggested to be involved in causing high mortality at low larval density, but it has not yet been explicitly tested if the well known spatial aggregation of insect eggs yields a fitness benefit for the developing larvae in the presence of noxious moulds. 2. Using Drosophila melanogaster, the present study tested whether larval survival is greater in aggregations when confronted with various combinations of three representative mould species (Aspergillus, Alternaria, and Penicillium) and a head start for fungal development. 3. High rates of fungal‐dependent mortality and significant positive density‐dependent larval survival (i.e. Allee effects) were observed when larvae were confronted with food resources containing established colonies of Aspergillus or Alternaria. Neither the simultaneous transfer of Aspergillus or Alternaria spores with larvae to food patches nor food infections with Penicillium affected insect larval development. 4. Significant correlations between mould growth and larval survival could be identified, although the patterns that emerged were shown to be inconsistent when the effects were compared between fungal species and fungal priority. Because mould growth only partly explained larval survival, the influence of other fungal‐borne factors, e.g. mycotoxins, needs to be elucidated in order to understand the mechanistic basis of insect–mould interactions. 5. These results are the first to argue convincingly for moulds being involved in mediating Allee effects for insects on ephemeral resources; however they also demonstrate an unexpected diversity in insect–mould interactions. Considering this diversity may be important in understanding insect spatial ecology.     

Corticomotor correlates of somatosensory reaction time and variability in individuals with post concussion symptoms

Abstract

Persistent post concussion symptoms (PPCS) describe the condition when an individual experiences chronic symptoms, particularly fatigue, beyond the expected time of recovery. The aim of this study was to quantify the effect of fatigue and related ongoing symptoms on somatosensory and corticomotor pathways using reaction time (RT) testing, and single-pulse and paired-pulse transcranial magnetic stimulation (TMS). Eighty-three participants (nine female, mean age 37.9?±?11.5?years) were divided into two groups (persistent symptoms versus asymptomatic) following self-report based upon previously published clinical symptom scores. All participants completed somatosensory and visuomotor RT testing, as well as corticomotor excitability and inhibition measurements via TMS. Participants in the persistent symptom group (n?=?38) reported greater number of previous concussions (t?=?2.81, p?=?0.006) and significantly higher levels of fatigue and related symptoms in the asymptomatic group (n?=?45; t?=?11.32, p?<?0.006). Somatosensory RT showed significant slowing and increased variability in the persistent symptoms group (p?<?0.001), however no significant differences were observed between groups for visuomotor RTs. Transcranial magnetic stimulation revealed differences between groups for intracortical inhibition at all stimulus intensities and paired pulse measures. The results indicate that somatosensory and corticomotor systems reflect on-going fatigue. From a practical perspective, objective and simplistic measures such as somatosensory and corticomotor measures can be used in the assessment of PPCS and gauging the efficacy of post concussion rehabilitation programmes.     

Fecal fungal flora of pediatric healthy volunteers and immunosuppressed patients

Most hematogenous candidiasis originates from endogeneous host flora. Fungal flora of gastrointestinal system are important source of infection especially in immunosupressed patients. The purpose of this study was to investigate the fecal fungal flora of pediatric patients with hematologic malignancy or disorders and to compare the results with healthy volunteers. For this purpose, fungal etiological agents were investigated retrospectively in stool samples of 80 patients followed in Bone marrow transplantation and Hematology–Oncology units. The diagnosis of patients were as follows: 26 acute myelogeneous leukemia, 19 acute lymphocytic leukemia, 5 lymphoma, 3 chronic myelogeneous leukemia, 2 solid tumor, 4 neuroblastoma and 21 hematologic disorders. In patients, totally 102 fungal growth was detected and 42 (41.2%) C. albicans and 51 (50%) non-albicans Candida species and 9 (8.8%) yeast other than Candida and mould was isolated. The results were compared prospectively with growth in stool samples of 61 healthy children. C. albicans was detected in 16 (43.2%) and non-albicans Candida species in 15 (40.5%) and yeasts other than Candida and mould in 6 (16.2%) of 37 fungal growth in controls. Non-albicans Candida species growth was found significantly higher and C. glabrata was more prevelant in patients than in controls (p < 0.001).     

Chronotype and its relationship with sleep disorders in children with attention deficit hyperactivity disorder

Chronotype can be classified as morningness types, people who prefer morning hours for their physical and mental activities; eveningness types, people who prefer the afternoon or evening hours; and intermediate types, those who show characteristics of both morningness and eveningness types. Attention deficit hyperactivity disorder (ADHD) has been linked with disturbances in chronotype, particularly increased eveningness. Despite the possibility of an association between chronotypes, sleep disturbances and ADHD symptoms, there is little evidence of this association considering the child population. The purpose of this study was to examine chronotype preferences in children aged between 7 and 12 years who were diagnosed as having ADHD in the context of sleep disturbances. The Schedule for Affective Disorders and Schizophrenia for School Age Children-Present and Lifetime Version, Conner’s Rating Scales, Children’s Sleep Habit Questionnaire and Children’s Chronotype Questionnaire were used for the evaluation of children with ADHD and healthy controls. The ADHD group was 73% combined-type, and the eveningness scores of the ADHD group (n = 52) were significantly higher than the control group (n = 52) (p < 0.01). There was a positive correlation between the higher scores of eveningness and total scores on resistance to sleep time (p < 0.09), respiratory problems during sleep and daytime sleepiness in the ADHD group. CSHQ total score was found to be a predictive factor for eveningness among children with ADHD (p < 0.01). These findings highlight possible reciprocal links between ADHD symptoms, sleep disturbances and chronotype in children aged 7–12 years, which might lead to individualized treatment options.     

Use of fungal metabolites to protect wood-based panels against mould infection

Wood-based composites such as oriented strand board (OSB) are principle framing elements in building construction in North America. However, these materials are often affected by moulds in wet or humid environmental conditions. A common control method for prevention of mould growth on panels is preservative treatment of panels with various pesticides or chemicals. In recent years, environmentally friendly pest control methods are required because of environmental issue. This research aimed to develop a biological technology to protect OSB against mould infection by post-treatment of panels with natural extracts from fungal antagonists. In this study, the culture metabolites of a fungal antagonist, Phaeotheca dimorphospora DesRochers & Ouellette, were extracted, and the antibiotic activity of the extracts was tested in Petri plates against various moulds and decay fungi. The OSB panels were then dip-treated with the extracts and exposed to a humid environment for mould growth testing in a period of 8 weeks. The results showed that the mycelia growth of all fungi tested (moulds, white-rot and brown-rot fungi) was inhibited by the extracts of P. dimorphospora on agar plates. Panel samples dipped with the fungal extracts in acetone got little mould growth on them, whereas untreated control panels and those samples treated with acetone alone were seriously affected by various moulds.     

Competition and Coexistence In a Multi-partner Mutualism: Interactions Between two Fungal Symbionts of the Mountain Pine Beetle In Beetle-attacked Trees

Despite overlap in niches, two fungal symbionts of the mountain pine beetle (Dendroctonus ponderosae), Grosmannia clavigera and Ophiostoma montium, appear to coexist with one another and their bark beetle host in the phloem of trees. We sampled the percent of phloem colonized by fungi four times over 1 year to investigate the nature of the interaction between these two fungi and to determine how changing conditions in the tree (e.g., moisture) affect the interaction. Both fungi colonized phloem at similar rates; however, G. clavigera colonized a disproportionately larger amount of phloem than O. montium considering their relative prevalence in the beetle population. High phloem moisture appeared to inhibit fungal growth shortly after beetle attack; however, by 1 year, low phloem moisture likely inhibited fungal growth and survival. There was no inverse relationship between the percent of phloem colonized by G. clavigera only and O. montium only, which would indicate competition between the species. However, the percent of phloem colonized by G. clavigera and O. montium together decreased after 1 year, while the percent of phloem from which no fungi were isolated increased. A reduction in living fungi in the phloem at this time may have significant impacts on both beetles and fungi. These results indicate that exploitation competition occurred after a year when the two fungi colonized the phloem together, but we found no evidence of strong interference competition. Each species also maintained an exclusive area, which may promote coexistence of species with similar resource use.     

Obesity and impairment in psychosocial functioning in women: the mediating role of eating disorder features

Objective: The objective was to test the hypothesis that, in women, the association between obesity and impairment in psychosocial functioning is mediated by levels of weight and shape concerns and/or binge‐eating frequency. Research Methods and Procedures: Self‐report measures of eating disorder psychopathology, mental health functioning, subjective quality of life in the psychological and social domains, and days “out‐of‐role” associated with any (physical or mental) health problem, were completed by a community sample of women classified as obese (BMI ≥30 kg/m², n = 639) or non‐obese (BMI <30 kg/m², n = 4253). For each of the dependent measures, regression models were used to test the hypothesis of mediation by comparing the strength of the relationship between independent and dependent variables with and without inclusion of the putative mediator in the regression model. Results: On each measure, the conditions for perfect mediation were satisfied when weight or shape concerns acted as the putative mediator, indicating that there was no association between obesity and functional impairment after controlling for weight or shape concerns. In contrast, associations between obesity and impairment in psychosocial functioning remained highly significant when binge‐eating frequency was the putative mediator. Discussion: The findings suggest that in women, weight and shape concerns are an important mediator of the relationship between obesity and impairment in psychosocial functioning, whereas binge eating may not be of primary importance. A greater focus on body acceptance in obesity treatment may be indicated.     

Effect of essential oils on postharvest decay and quality factors of tomato in vitro and in vivo conditions

For increasing the shelf life and control of devastating fungal pathogen grey mould (Botrytis cinerea), tomato fruits during storage were applied different concentrations of ammi (Carum copticum) and anise (Pimpinella anisum) essential oils. First, antifungal activities of essential oils were tested on artificial growth media. The growth of grey mould was completely inhibited by ammi and anise essential oils at relatively higher concentrations. In second stage, fruits were infected artificially by grey mould spore and then treated with different concentrations of these essential oils. The results of in vivo conditions showed that ammi and anise essential oils applied at all concentrations were increasing the shelf life and inhibited the grey mould growth on tomato fruits completely in comparison to control. Fruits treated with these essential oils had significantly higher total soluble solids (TSS), ascorbic acid, β-carotene and lycopene content compared to control fruits.     

Host-induced gene silencing of BcTOR in Botrytis cinerea enhances plant resistance to grey mould

Botrytis cinerea is the causal agent of grey mould for more than 200 plant species, including economically important vegetables, fruits and crops, which leads to economic losses worldwide. Target of rapamycin (TOR) acts a master regulator to control cell growth and proliferation by integrating nutrient, energy and growth factors in eukaryotic species, but little is known about whether TOR can function as a practicable target in the control of plant fungal pathogens. Here, we characterize TOR signalling of B. cinerea in the regulation of growth and pathogenicity as well as its potential value in genetic engineering for crop protection by bioinformatics analysis, pharmacological assays, biochemistry and genetics approaches. The results show that conserved TOR signalling occurs, and a functional FK506-binding protein 12 kD (FKBP12) mediates the interaction between rapamycin and B. cinerea TOR (BcTOR). RNA sequencing (RNA-Seq) analysis revealed that BcTOR displayed conserved functions, particularly in controlling growth and metabolism. Furthermore, pathogenicity assay showed that BcTOR inhibition efficiently reduces the infection of B. cinerea in plant leaves of Arabidopsis and potato or tomato fruits. Additionally, transgenic plants expressing double-stranded RNA of BcTOR through the host-induced gene silencing method could produce abundant small RNAs targeting BcTOR, and significantly block the occurrence of grey mould in potato and tomato. Taken together, our results suggest that BcTOR is an efficient target for genetic engineering in control of grey mould, and also a potential and promising target applied in the biocontrol of plant fungal pathogens.     

Abdominal Subcutaneous and Visceral Adipose Tissue and Insulin Resistance in the Framingham Heart Study

Insulin resistance is associated with central obesity and an increased risk of cardiovascular disease. Our objective is to examine the association between abdominal subcutaneous (SAT) and visceral adipose tissue (VAT) and insulin resistance, to determine which fat depot is a stronger correlate of insulin resistance, and to assess whether there was an interaction between SAT, VAT, and age, sex, or BMI. Participants without diabetes from the Framingham Heart Study (FHS), who underwent multidetector computed tomography to assess SAT and VAT (n = 3,093; 48% women; mean age 50.4 years; mean BMI 27.6 kg/m²), were evaluated. Insulin resistance was measured using the homeostasis model and defined as HOMA_IR ≥75th percentile. Logistic regression models, adjusted for age, sex, smoking, alcohol, menopausal status, and hormone replacement therapy use, were used to assess the association between fat measures and insulin resistance. The odds ratio (OR) for insulin resistance per standard deviation increase in SAT was 2.5 (95% confidence interval (CI): 2.2–2.7; P < 0.0001), whereas the OR for insulin resistance per standard deviation increase in VAT was 3.5 (95% CI: 3.1–3.9; P < 0.0001). Overall, VAT was a stronger correlate of insulin resistance than SAT (P < 0.0001 for SAT vs. VAT comparison). After adjustment for BMI, the OR of insulin resistance for VAT was 2.2 (95% CI: 1.9–2.5; P < 0.0001). We observed an interaction between VAT and BMI for insulin (P interaction = 0.0004), proinsulin (P interaction = 0.003), and HOMA_IR (P interaction = 0.003), where VAT had a stronger association in obese individuals. In conclusion, SAT and VAT are both correlates of insulin resistance; however, VAT is a stronger correlate of insulin resistance than SAT.     

Prevalence of Sleep Apnea and Electrocardiographic Disturbances in Morbidly Obese Patients

Objective: To determine the prevalence of sleep apnea in morbidly obese patients and its relationship with cardiac arrhythmias. Research Methods and Procedures: Fifty‐two consecutive morbidly obese (body mass index ≥ 40 kg/m²) outpatients from the Obesity Clinic of the National Institute of Nutrition Salvador Zubirán underwent two nights of polysomnography with standard laboratory techniques. Electrocardiographic polysomnography signals (Lead II) were evaluated by two experienced cardiologists, and sleep complaints were measured with a standard sleep questionnaire (Sleep Disorders Questionnaire). In order to make comparisons between groups with different severities of sleep‐disordered breathing, we classified the patients in four groups using the apnea‐hypopnea index (AHI): Group 1, AHI 5 < 15 (n = 10); Group 2, AHI 15 < 30 (n = 10); Group 3, AHI 30 < 65 (n = 14); Group 4, AHI ≥ 65 (n = 17). Results: A wide range of sleep‐disordered breathing, ranging from AHI of 2.5 to 128.9 was found. Ninety‐eight percent of the sample (n = 51) had an AHI ≥ 5 (mean = 51 ± 37), and 33% had severe sleep apnea with AHI ≥ 65 with a mean nocturnal desaturation time of <65% over 135 minutes. Electrocardiographic abnormalities were present in 31% of the patients. Cardiac rhythm alterations showed an association with the level of sleep‐disordered breathing and oxygen desaturation. Discussion: We conclude that there is a high prevalence of sleep apnea in morbidly obese patients and that the risk for cardiac arrhythmias increases in this population in the presence of a severe sleep apnea (AHI ≥ 65) with severe oxygen desaturation (Sao ₂ ≤ 65%).     

Blue mould decay of stored onion bulbs caused by Penicillium polonicum,P. glabrum and P. expansum

Onion bulbs (Allium cepa L.) can be stored for up to 12 months to ensure their availability all year, but one of the limiting factors is decay caused by blue mould fungi. Postharvest development of blue mould is not only economically important, but also poses a health hazard due to mycotoxin contamination. Onion bulbs of different yellow and red cultivars with blue mould symptoms were collected from three storage facilities in Serbia. Pathogenic isolates were identified and characterized based on their molecular (partial β‐tubulin gene), morphological (micro‐ and macromorphology, and colony growth) and biochemical properties (analyses of indole metabolites via Ehrlich test). Three Penicillium species were identified: P. polonicum, P. glabrum and P. expansum. Virulence on inoculated onion bulbs varied significantly within isolates of P. glabrum, but the most virulent isolate of P. polonicum and P. glabrum did not differ, nor did they differ from an isolate of P. expansum. Variability in virulence of individual P. glabrum isolates corresponded to differences in their molecular and macromorphological characters. P. glabrum and P. expansum were identified for the first time as causal agents of onion bulb decay in Serbia. Data from this investigation provide insight into diversity of economically important and possibly toxigenic blue mould fungi which brings attention to their presence in storage facilities and therefore the necessity of the application of prevention measures.     

Isolates of Microdochium nivale and M. majus Differentiated by Pathogenicity on Perennial Ryegrass (Lolium perenne L.) and in vitro Growth at Low Temperature

Pink snow mould is a serious disease on grasses and winter cereals in cold and temperate zones during winter. To better understand the basis for the variation in pathogenicity between different isolates of Microdochium nivale and M. majus and to simplify selection of highly pathogenic isolates to use when screening for resistance to pink snow mould in perennial ryegrass, we sought traits correlated with pathogenicity. Isolates of M. nivale were more pathogenic on perennial ryegrass than isolates of M. majus, as measured by survival and regrowth of perennial ryegrass after infection and incubation under simulated snow cover. Pathogenicity as measured by relative regrowth was highly correlated with fungal growth rate on potato dextrose agar (PDA) at 2°C. Measuring fungal growth on PDA therefore seems to be a relatively simple method of screening for potentially highly pathogenic isolates. In a study of a limited number of isolates, highly pathogenic isolates showed an earlier increase and a higher total specific activity of β‐glucosidase, a cell wall‐degrading enzyme, compared with less pathogenic isolates. None of the M. majus isolates was highly pathogenic on perennial ryegrass. Our results indicate biological differences between M. nivale and M. majus and thus strengthen the recently published sequence‐based evidence for the elevation of these former varieties to species status.     

Genotypic variation for drought tolerance in cotton (Gossypium hirsutum L.): Leaf gas exchange and productivity

Although water-limited environments are detrimental to cotton growth and productivity worldwide, identification of cotton (Gossypium hirsutum L.) genotypes that are less sensitive to drought may improve productivity in drought prone areas. The objective of the study was to assess genotypic variation for drought tolerance in cotton varieties using physiological attributes as selection criteria, and to determine the relationship of physiological attributes with productivity traits. The association of target physiological traits for drought tolerance (photosynthetic rate (P_n), stomatal conductance (g_s), and transpiration rate (E)) with productivity traits under well-watered (W₁) and water-limited (W₂) regimes was analyzed using 32 public cotton cultivars/bred lines in two field experiments conducted during the normal cotton growing seasons 2003 and 2004. Seed cotton yield (SCY) and biological yield (BY) were markedly affected under W₂ regime in all cultivars except the outstanding performance of CIM-1100 and RH-510 proving their superiority to other cultivars in drought tolerance. Conversely, FH-901, FH-634, and FH-2000 were high yielding under W₁ regime; however, exhibited a sharp decline in yield under W₂ regime. A positive correlation between SCY and BY under water stress (r=0.44 in 2003; r=0.69 in 2004) indicates that BY is also a primary determinant of SCY under water stress and genetic improvement of BY under water-limited environment may also improve SCY. P_n, g_s, and E were significantly reduced by water stress. Substantial genotypic variation for gas exchange attributes existed among the cotton cultivars. A positive association (P<0.01) was observed between g_s and E under both regimes in both years indicating the prevalence of stomatal control of transpiration. The positive association (P<0.01) between P_n and g_s in both years in W₂ regime indicates also a major role of stomatal effects in regulating leaf photosynthesis under water-limited conditions. P_n was significantly correlated with SCY (P<0.01) and BY (P<0.05 in 2003; P<0.01 in 2004) in W₂ regime; however, the level of these associations was not significant in W₁ regime. These findings demonstrate that association of P_n with productivity is effective under water-limited environment and may be useful as a selection criterion in breeding programs with the objective of improving drought tolerance and SCY under water-limited environments. Moreover, association between SCY and BY under water stress suggests that genetic improvement of BY under water stress may also improve SCY.     

Comparison of techniques for sex determination of American martens

Accurate determination of sex in harvested species is critical for understanding demography and developing population models for management. We used genetic-based sex identification to assess accuracy of external carcass and pelt examination at registration and maximum canine root area (MRA) to determine sex of American martens (Martes americana) trapped in the Upper Peninsula of Michigan, 2000–2004. Overall percent similarity between MRA and genetic-based sex determination was 98.4% (n = 188). In contrast, only 84.6% (n = 421) of martens were similarly classified using external examination. For external examination, percent similarity to genetic-based sex determination for juveniles (<1-yr old) and adults (≥1-yr old; Wald χ²₁ = 2.168, P = 0.141), as well as for males and females (Wald χ²₁ = 0.005, P = 0.946), was similar. We recommend MRA as a suitable technique for sex determination of martens; thus, marten sex and age (using cementum annuli counts) can be obtained from one lower canine tooth. We do not recommend use of external examination at registration to identify sex of martens without implementing additional quality assurance measures. © 2010 The Wildlife Society.     

Indoor airborne fungi as risk factors in IgE-mediated respiratory allergy

The purpose of this epidemiological study was to assess respiratory allergy in relation to the presence of indoor airborne fungi. The relationship between IgE-mediated respiratory allergy (skin test positivity) and the presence of fungi (CFU/m³) in the indoor environments of 104 subjects was assessed in a cross-sectional study by controlling for extraneous variables (age, gender, predisposition, asthma, rhinitis, skin positivity to ragweed and mite, and smoking). The qualitative and quantitative measurements of airborne seasonal fungi (Alternaria spp. andCladosporium spp.) and non-seasonal airborne fungi (Penicillium spp. andAspergillus spp.) were taken in the subjects’ indoor environments twice in a 2-year period by volumetric methods (Burkard Personal Sampler). There was a significant association between skin test positivity to seasonal fungi and to ragweed (Adj. OR=3.42, CI=1.76–6.66). There was no association between skin test positivity to seasonal fungi and asthma (Adj. OR=0.52, CI=0.28–0.98), but a significant association was found between skin test positivity to seasonal fungi and rhinitis (Adj. OR=5, CI=2.03–12.32). In a logistic regression analysis (maximum likelihood estimates—model A), no statistical association was found indoors between skin prick test positivity to seasonal fungi (Alternaria and/orCladosporium) and airborneAlternaria and/orCladosporium concentrations (Adj. OR=1.18, CI=0.66–2.07). There was a significant association between skin prick test positivity to seasonal fungi and to non-seasonal fungi (Adj. OR=12.81, CI=1.67–98.34). There was no association between asthma and airbornePenicillium concentrations (Adj. OR=1.86, CI=0.47–7.33) nor between rhinitis and airbornePenicillium concentrations (Adj. OR=0.18, CI=0.03–1.19). In another logistic regression analysis (maximum likelihood estimates — model B) using non-seasonal fungi (Aspergillus andPenicillium), no statistical association was found indoors between skin prick test positivity to non-seasonal fungi and airbornePenicillium concentrations (Adj. OR=0.33, CI=0.07–1.69). These findings suggest an association between rhinitis and seasonal fungi. In the rhinitis stratum, subjects who had skin test positivity to ragweed had a higher risk of being sensitive to seasonal airborne fungal allergens. Subjects with non-seasonal fungal allergy had a high relative risk if they were also allergic to seasonal fungi. There was no association between asthma and airborne fungi, as the epidemiological study (cross-sectional design), by definition, does not allow an etiological evaluation of chronic disease. This would require a longitudinal study, i.e. the measurement of repeated exposure as an independent variable (allergen) and repeated measurement as a function of the disease as outcome in humans as a dependent variable.     

Phenotypic characterization and bulk segregant analysis of anther culture response in two backcross families of diploid potato

Two diploid (2n=2x=24) backcross potato populations (PBCp, and CBC) were characterized for anther culture response (ACR). PBCp (Solanum phureja Juz. & Buk. genotype 1-3 × CP2) and CBC (CP2 × S. chacoense Bitt. genotype 80-1) resulted from a cross between CP2 (intermediate ACR) and its parents, S. chacoense 80-1(low ACR) and S. phureja 1-3 (high ACR). Three components of ACR were initially investigated: embryos per anther (EPA), embryo regeneration rate and percent monoploids (2n=1x=12) among regenerants. EPA was selected for further characterization because of its relative stability. In a series of studies of EPA on a total of 44 genotypes within CBC, nine high (mean EPA=2.5) and ten low (mean EPA=0.02) selections were made. In PBCp, ten high (mean EPA= 4.7) and ten low (mean EPA= 0.05) selections were made from 67 genotypes. High and low selections were used for bulk segregant analysis to screen 214 RAPD primers as candidate markers linked to EPA. Bands amplified by OPQ-10 and OPZ-4 were associated in coupling and repulsion, respectively, to ACR in PBCp. A band amplified by OPW-14 primer was associated in coupling to ACR in CBC. One-way ANOVAs using presence/absence of each candidate band to classify additional genotypes in each population verified association of the markers with EPA.     

Body mass index and depressive symptoms: instrumental‐variables regression with genetic risk score

The causal role of obesity in the development of depression remains uncertain. We applied instrumental‐variables regression (Mendelian randomization) to examine the association of adolescent and adult body mass index (BMI) with adult depressive symptoms. Participants were from the Young Finns prospective cohort study (n = 1731 persons, 2844 person‐observations), with repeated measurements of BMI and depressive symptoms (modified Beck's Depression Inventory). Genetic risk score of 31 single nucleotide polymorphisms previously identified as robust genetic markers of body weight was used as a proxy for variation in BMI. In standard linear regression analysis, higher adult depressive symptoms were predicted by higher adolescent BMI (B = 0.33, CI = 0.06–0.60, P = 0.017) and adult BMI (B = 0.47, CI = 0.32–0.63, P < 0.001). These associations were replicated in instrumental‐variables analysis with genetic risk score as instrument (B = 1.96, CI = 0.03–3.90, P = 0.047 for adolescent BMI; B = 1.08, CI = 0.11–2.04, P = 0.030 for adult BMI). The association for adolescent BMI was significantly stronger in the instrumented analysis compared to standard regression (P = 0.04). These findings provide additional evidence to support a causal role for high BMI in increasing symptoms of depression. However, the present analysis also demonstrates potential limitations of applying Mendelian randomization when using complex phenotypes.     

Mifepristone Reduces Weight Gain and Improves Metabolic Abnormalities Associated With Risperidone Treatment in Normal Men

Antipsychotic medications are associated with significant weight gain, type 2 diabetes mellitus, dyslipidemia, and increased cardiovascular risk. The objective of this study was to determine whether mifepristone, a glucocorticoid receptor antagonist, could prevent risperidone‐induced weight gain. Using a 2:2:1 randomization scheme, 76 lean, healthy men (BMI 18–23 kg/m²) age 18–40 years were randomized to risperidone (n = 30), risperidone plus mifepristone (n = 30) or mifepristone (n = 16) daily for 28 days in an institutional setting. Subjects were provided food ad libitum. Body weight was measured daily. Metabolic measures were taken at study onset, midpoint, and end. Analyses of covariance indicated that the group receiving risperidone plus placebo gained significantly more weight (P < 0.001) and exhibited a significantly greater increase in waist circumference (P < 0.05) than the group receiving risperidone plus mifepristone. Significant differences were also observed for metabolic measures including fasting insulin (P < 0.001) and triglyceride levels (P < 0.05). Mifepristone attenuated increases in weight and reduced the metabolic changes induced by risperidone use, replicating results from a prior study of olanzapine‐induced weight gain. These findings suggest mechanistic involvement of the hypothalamic‐pituitary‐adrenal axis in the weight and cardiometabolic side effects of antipsychotic medications. Future research should continue to test the potential of glucocorticoid antagonists to alleviate the deleterious side effects associated with use of antipsychotic medications.