Mitigation of Salinity Stress and Lead Toxicity in Maize by Exogenous Application of the Sorghum Water Extract

The increased concentration of lead (Pb) in soils is a serious threat to human beings and plants all over the world. Salinity stress is also a major issue across the globe, which limits crop productivity. The use of allelochemicals has become an effective strategy to mitigate the toxic effects of abiotic stresses. Sorghum is an important crop grown across the globe, and it also possesses an appreciably allelopathic potential. Therefore, this study was planned to determine the impacts of the sorghum water extract (SWE) on improving maize growth under Pb and salinity stress. The experiment included different treatments; control, SWE (3%), and different levels of Pb and salinity stress; T1: control, T2: 50 mM NaCl, T3: 100 mM NaCl, T4: 250 μM Pb, and T5: 500 μM Pb. Lead and salinity stress reduced the maize growth by the genesis of reactive oxygen species (ROS), as evidenced by higher production of malondialdehyde (MDA: 39.1 and 32.28%) and hydrogen peroxide (H2O2: 20.62 and 17.81%). Spraying plants with SWE improved the maize growth by increasing antioxidant activities (ascorbate peroxidase: APX, catalase: CAT, peroxidase: POD and superoxide dismutase: SOD), photosynthetic pigments, relative water contents (RWC), osmolyte accumulation (proline, total soluble proteins: TSP, free amino acids: FAA), potassium accumulation, and decreasing MDA, H2O2, sodium, chloride, and Pb accumulation. In conclusion, the application of SWE mitigates adverse impacts of Pb and salinity stresses by improving chlorophyll synthesis and osmolyte accumulation, activating the antioxidant defense system, and preventing the entry of toxic ions.

Si-enriched biochars improved soil properties, reduced Cd bioavailability while enhanced Cd translocation to grains of rice

Biochar and silicon (Si) have been widely considered to play an important role in mitigating cadmium (Cd) toxicity. In this study, wild-type rice (WT, high-Si) and Si-deficient mutant rice (lsi1, low-Si) were used as raw materials to prepare biochar at 500℃; the Si concentrations of high- and low-Si biochar were 15.9% and 5.3%, respectively. The impacts of different application rates (0%, 2%, 4%) of high- and low-Si biochars on soil chemical properties, Si and Cd fractions and availability, Cd absorption, and translocation were investigated. The results showed that both types of biochars increased soil pH, soil available nitrogen, and available phosphorus and potassium; and promoted Si uptake and plant growth of rice. Soil available Si, CaCl2-Si, acetic-Si, H2O2-Si, oxalate-Si, and Na2CO3-Si were also increased by biochar supply, especially for high-Si biochar treatments. In addition, both types of biochars had no effects on soil total Cd, but reduced soil available Cd by 2-17% in early season 2022, and reduced oxidizable Cd and residual Cd. Biochar application did not influence Cd concentrations in roots, stems, and leaves, but significantly increased Cd uptake and transport from stems and leaves to grains. The results suggested that Si-rich biochar could improve soil nutrients, change soil Si/Cd fractions and availability, promote rice growth but increase the risk of Cd toxicity in grains, indicating the complex of straw biochar in remediating Cd-contaminated paddy soil.

nirS and nosZII bacterial denitrifiers as well as fungal denitrifiers are coupled with N2O emissions in long-term fertilized soils

Fertilizer application plays a critical role in soil fertility and crop yield and has been reported to significantly affect soil denitrification. However, the mechanisms by which denitrifying bacteria (nirK, nirS, nosZI, and nosZII) and fungi (nirK and p450nor) affect soil denitrification are poorly understood. Therefore, in this study, we investigated the effect of different fertilization treatments on the abundance, community structure, and function of soil denitrifying microorganisms in an agricultural ecosystem with long-term fertilization using mineral fertilizer or manure and their combination. The results showed that the application of organic fertilizer significantly increased the abundance of nirK-, nirS-, nosZI-, and nosZII-type denitrifying bacteria as the soil pH and phosphorus content increased. However, only the community structure of nirS- and nosZII-type denitrifying bacteria was influenced by the application of organic fertilizer, which led to a higher contribution of bacteria to nitrous oxide (N2O) emissions than that observed after inorganic fertilizer application. The increase in soil pH reduced the abundance of nirK-type denitrifying fungi, which may have presented a competitive disadvantage relative to bacteria, resulting in a lower contribution of fungi to N2O emissions than that observed after inorganic fertilizer application. The results demonstrated that organic fertilization had a significant impact on the community structure and activity of soil denitrifying bacteria and fungi. Our results also highlighted that after organic fertilizer application, nirS- and nosZII-denitrifying bacteria communities represent likely hot spots of bacterial soil N2O emissions while nirK-type denitrifying fungi represent hot spots for fungal soil N2O emissions.

Enhancing Sugarcane Yield and Sugar Quality through Optimal Application of Polymer-Coated Single Super Phosphate and Irrigation Management

The judicious use of crop input is of prime importance for achieving a considerable output with a low-cost input. A two-year field experimentation was executed to assess the effect of varying polymer-coated single super phosphate (SSP) regimes on the yield and quality of sugarcane under differential water regimes. A two-factor study was executed under a randomized complete block design with a split-plot arrangement. The CPF-249 sugarcane variety was planted during the 2019-2020 period and the 2020-2021 period. The experiment consisted of four levels of polymer-coated SSP, i.e., control, 90, 110, and 130 kg ha-1, and three water regimes, which consisted of a number of irrigations, i.e., 18 irrigations, 15 irrigations, and 12 irrigations. Moreover, the water regimes were kept in the main plot, whereas the polymer-coated supplement was allocated in a subplot and replicated thrice. The data on the yield components and sugar-related traits were recorded during both years of study, and the treatment means were differentiated using an LSD test at a 95% confidence interval. Summating the findings of this study, a significant variation was revealed under the subject levels of both factors. Statistically, a 110 kg ha-1 polymer-coated SSP dose, along with 18 irrigations, declared the highest millable canes, stripped cane yield, and unstripped cane yield, followed by the 130 kg ha-1 treatment. Additionally, the highest pol% and cane sugar recovery % were recorded under 12 irrigations along with 130 kg ha-1 during both years. Similarly, the °Brix value was also significantly affected by 12 irrigations when 110 kg ha-1 of polymer-coated SSP was used. The unstripped cane yield had a strong positive correlation with the stripped cane yield, millable canes, and the number of internodes. Moreover, the commercial cane sugar % resulted in a strong positive correlation with the pol%, whereas the cane sugar recovery % revealed a strong positive correlation with the pol% and commercial cane sugar %.

Soil acidification and salinity: the importance of biochar application to agricultural soils

Soil acidity is a serious problem in agricultural lands as it directly affects the soil, crop production, and human health. Soil acidification in agricultural lands occurs due to the release of protons (H+) from the transforming reactions of various carbon, nitrogen, and sulfur-containing compounds. The use of biochar (BC) has emerged as an excellent tool to manage soil acidity owing to its alkaline nature and its appreciable ability to improve the soil's physical, chemical, and biological properties. The application of BC to acidic soils improves soil pH, soil organic matter (SOM), cation exchange capacity (CEC), nutrient uptake, microbial activity and diversity, and enzyme activities which mitigate the adverse impacts of acidity on plants. Further, BC application also reduce the concentration of H+ and Al3+ ions and other toxic metals which mitigate the soil acidity and supports plant growth. Similarly, soil salinity (SS) is also a serious concern across the globe and it has a direct impact on global production and food security. Due to its appreciable liming potential BC is also an important amendment to mitigate the adverse impacts of SS. The addition of BC to saline soils improves nutrient homeostasis, nutrient uptake, SOM, CEC, soil microbial activity, enzymatic activity, and water uptake and reduces the accumulation of toxic ions sodium (Na+ and chloride (Cl-). All these BC-mediated changes support plant growth by improving antioxidant activity, photosynthesis efficiency, stomata working, and decrease oxidative damage in plants. Thus, in the present review, we discussed the various mechanisms through which BC improves the soil properties and microbial and enzymatic activities to counter acidity and salinity problems. The present review will increase the existing knowledge about the role of BC to mitigate soil acidity and salinity problems. This will also provide new suggestions to readers on how this knowledge can be used to ameliorate acidic and saline soils.

Exogenous Gamma-Aminobutyric Acid Application Induced Modulations in the Performance of Aromatic Rice Under Lead Toxicity

Gamma-aminobutyric acid (GABA) is a non-protein amino acid and has a multi-functional role in abiotic stress tolerance. A pot experiment was conducted to assess the role of exogenous gamma-aminobutyric acid (GABA) application to modulate the growth, yield, and related physio-biochemical mechanisms in two aromatic rice cultivars, that is, Guixiangzhan (GXZ) and Nongxiang 18 (NX-18), under Pb toxic and normal conditions. The experimental treatments were comprised of Ck: without Pb and GABA (control), GABA: 1 mM GABA is applied under normal conditions (without Pb), Pb + GABA: 1 mM GABA is applied under Pb toxicity (800 mg kg^-1 of soil), and Pb= only Pb (800 mg kg^-1 of soil) is applied (no GABA). The required concentrations of GABA were applied as a foliar spray. Results revealed that Pb stress induced oxidative damage in terms of enhanced malondialdehyde (MDA), electrolyte leakage (EL), and H₂O₂ contents, while exogenous GABA application improved leaf chlorophyll, proline, protein and GABA contents, photosynthesis and gas exchange, and antioxidant defense under Pb toxicity in both rice cultivars. Moreover, glutamine synthetase (GS) and nitrate reductase (NR) activities were variably affected due to GABA application under Pb stress. The yield and related traits, that is, productive tillers/pot, grains/panicle, filled grain %, 1,000-grain weight, and grain yield were 13.64 and 10.29, 0.37% and 2.26%, 3.89 and 19.06%, 7.35 and 12.84%, and 17.92 and 40.56 lower under Pb treatment than Pb + GABA for GXZ and NX-18, respectively. Furthermore, exogenous GABA application in rice reduced Pb contents in shoot, leaves, panicle, and grains compared with Pb-exposed plants without GABA. Overall, GXZ performed better than NX-18 under Pb toxic conditions.

Conformance of sowing dates for maximizing heat use efficiency and seed cotton yield in arid to semi-arid cotton zone of Pakistan

Pakistan is placed among the most vulnerable countries with relation to climate change and its impacts on agricultural productivity. Cotton is staged as the cash crop of the country and the main source of raw material for textile, oil, and feed industry. Varying environmental attributes have significant effects on the duration of vegetative and reproductive stages of cotton crop. To evaluate the potential impacts of varied temperatures regimes in different sowing times, field experiments were carried out throughout the cotton growing areas of Pakistan from Faisalabad in Central Punjab to RYK in Southern Punjab and Sakrand in Sindh to Dera Ismail Khan in Khyber Pakhtunkhwa (KPK) Province. Crop was sown on six different sowing dates starting from 1st March towards 15th May with 2-week intervals for two crop seasons (2016 and 2017). The timing of phenological events like emergence, squaring, flowering, and boll opening was recorded on calendar days and cumulative heat units (GDDs) were calculated for flowering and boll opening stages. Heat use efficiency for these sowing times was estimated. Data regarding yield-related parameters like opened bolls per plant, average boll weight, and seed cotton yield were also recorded during the study. Results revealed that duration of the growth stages was significantly affected by variation in mean thermal kinetics in varied sowing times in all four different environments. Seed cotton yield and heat use efficiency were also varied among the locations and sowing dates. The maximum seed cotton yield was recorded in Sakrand location at 15th April sowing date. The dependence of the phenological advancement on temperature and negative impacts of higher thermal stress on cotton productivity were also confirmed throughout the cotton growing zone of Pakistan.

Molybdenum improves 2-acetyl-1-pyrroline, grain quality traits and yield attributes in fragrant rice through efficient nitrogen assimilation under cadmium toxicity

Cadmium (Cd) toxicity causes severe perturbations in nitrogen (N) uptake and assimilation, and thereby interrupts normal plant growth. Molybdenum (Mo), a necessary trace element, plays important roles in N metabolism through regulating N assimilatory enzymes activities and expressions in higher plants. Taking this into account, a pot experiment was performed to explore the role of Mo in alleviating Cd-induced inhibitory effects on physio-biochemical processes, N metabolism, yield attributes and grain quality characters of two fragrant rice cultivars; Guixiangzhan and Meixiangzhan-2. Both the fragrant rice cultivars were treated with two levels of each Cd concentrations (0 and 100 mg/kg) and Mo treatments (0 and 0.15 mg/kg). The results revealed that Cd toxicity significantly reduced (p < 0.05) plant dry biomass, gaseous exchange attributes, chlorophyll contents, N utilizing and assimilatory enzymes activities, 2-acetyl-1-pyrroline (2AP) contents and grain yield in both cultivars; however, more severe inhibitions were observed in Meixiangzhan-2 than Guixiangzhan. Nevertheless, Mo application alleviated Cd stress and enhanced 2AP content and grain yield by 75.05% and 67.94% in Guixiangzhan and 87.71% and 83.51% in Meixiangzhan-2, respectively compared with no Mo application. Moreover, Mo application improved photosynthesis, chloroplast configuration, soluble protein and proline contents and also strengthened the N assimilatory pathway through efficient NO₃^- utilization, higher nitrate reductase, nitrite reductase, glutamine synthetase and glutamate synthase activities and transcript levels under Cd stress. Collectively, our results imply that Mo-induced enhancement in N utilization and assimilation improved yield and grain quality characters of fragrant rice cultivars under Cd stress.

Climate change impacts and adaptations for fine, coarse, and hybrid rice using CERES-Rice

Climate change has become a threatening issue for major field crops of Pakistan, especially rice. A 2 years' (2014 and 2015) field trial was conducted on fine, coarse, and hybrid rice at Research Area, Department of Agronomy, University of Agriculture, Faisalabad following the split-plot design. Data of growth, yield, and yield components were collected to calibrate and evaluate the CERES-Rice model under Decision Support System for Agro-technology Transfer (DSSAT). Two cultivars of each type of fine, coarse, and hybrid rice were transplanted with interval of fortnight from May to September during 2014 and 2015. The model was calibrated with non-stressed sowing data during the year 2014 and evaluated with the data of 2015. Climate change scenarios were generated for mid-century (2040-2069) under representative concentration pathway (RCP8.5) using different general circulation models (GCMs) (baseline, cool dry, hot dry, cool wet, hot wet, and middle) were using different General Circulation Models (GCMs). CERES-Rice calibration and evaluation results were quite good to simulate impacts of climate change and to formulate adaptations during 2040-2069 (mid-century). Simulations of all GCMs showed an average increase of 3 °C in average temperature as compared to baseline (1980-2010). Likewise, there would be an average increase of 107.6 mm in rainfall than baseline. The future rise in temperature will reduced the paddy yield by 10.33% in fine, 18-54% in coarse and 24-64% in hybrid rice for mid-century under RCP8.5. To nullified deleterious effects of climate change, some agronomic and genetics adaptation strategies were evaluated with CERES-rice during mid-century. Paddy yield of fine rice was increased by 15% in cool dry and 5% in hot dry GCM. Paddy yield of coarse rice was improved by 15% and 9% under cool dry and hot dry climatic conditions, respectively, with adaptations. For hybrid rice, paddy yield was enhanced by 15% and 0.3% with cool wet and hot dry climatic conditions, respectively. Hot dry climatic conditions were the most threatening for rice crop in rice producing areas of Punjab, Pakistan.

Biochar mitigates the N2O emissions from acidic soil by increasing the nosZ and nirK gene abundance and soil pH

Nitrous oxide (N₂O) is a pervasive greenhouse gas, and soil management practices greatly affect its release into the atmosphere. Soil pH management (particularly increasing the pH) using biochar can seriously affect soil N₂O emissions. The current incubation experiment was conducted to explore the response of N₂O emissions from acidic soils using various doses of biochar. Soil with a pH of 5.48 was treated with rice straw biochar at different doses (0%, 1% and 2%) and incubated with 60% water-filled pore spaces (WFPS). The experiment was conducted in a completely randomized design (CRD) with three replications. The soil N₂O emissions, pH, NH₄⁺-N, NO₃^--N, microbial biomass carbon (MBC), and nosZ and nirK gene abundance were determined at various intervals throughout the study. The biochar application (2%) increased the soil pH (from 5.48 to 6.11), triggered the transformation of nitrogen, and augmented the abundance of nosZ and nirK genes. Higher magnitudes of cumulative soil N₂O emissions (48.60 μg kg^-1) were noted in the control (no biochar) compared to 1% (28.10 μg kg^-1) and 2% (14.50 μg kg^-1) biochar application. The 2% biochar application more effectively decreased the soil N₂O emissions, mainly because of the increased nosZ and nirK gene abundance at higher soil pH levels. The findings suggest that the amelioration of acidic soil with rice straw biochar can considerably control soil N₂O emissions by elevating the soil pH and the abundance of nosZ and nirK genes.

Molybdenum-Induced Effects on Nitrogen Metabolism Enzymes and Elemental Profile of Winter Wheat (Triticum aestivum L.) Under Different Nitrogen Sources

Different nitrogen (N) sources have been reported to significantly affect the activities and expressions of N metabolism enzymes and mineral elements concentrations in crop plants. However, molybdenum-induced effects in winter wheat cultivars have still not been investigated under different N sources. Here, a hydroponic study was carried out to investigate these effects on two winter wheat cultivars (‘97003’ and ‘97014’) as Mo-efficient and Mo-inefficient, respectively, under different N sources (NO₃⁻, NH₄NO₃, and NH₄⁺). The results revealed that the activities of nitrate reductase (NR) and nitrite reductase (NiR) followed the order of NH₄NO₃ > NO₃⁻ > NH₄⁺ sources, while glutamine synthetase (GS) and glutamate synthase (GOGAT) followed the order of NH₄⁺ > NH₄NO₃ > NO₃⁻ in both the wheat cultivars. However, Mo-induced effects in the activities and expressions of N metabolism enzymes under different N sources followed the order of NH₄NO₃ > NO₃⁻ > NH₄⁺ sources, indicating that Mo has more complementary effects towards nitrate nutrition than the sole ammonium source in winter wheat. Interestingly, under −Mo-deprived conditions, cultivar ‘97003’ recorded more pronounced alterations in Mo-dependent parameters than ‘97014’ cultivar. Moreover, Mo application increased the proteins, amino acids, ammonium, and nitrite contents while concomitantly decreasing the nitrate contents in the same order of NH₄NO₃ > NO₃⁻ > NH₄⁺ sources that coincides with the Mo-induced N enzymes activities and expressions. The findings of the present study indicated that Mo plays a key role in regulating the N metabolism enzymes and assimilatory products under all the three N sources; however, the extent of complementation exists in the order of NH₄NO₃ > NO₃⁻ > NH₄⁺ sources in winter wheat. In addition, it was revealed that mineral elements profiles were mainly affected by different N sources, while Mo application generally had no significant effects on the mineral elements contents in the winter wheat leaves under different N sources.

P115 Subarachnoid haemorrhage with negative initial vascular imaging: a single unit experience

Objectives

To investigate the incidence of vascular abnormality and clinical outcomes in a group of patients presenting with spontaneous subarachnoid haemorrhage (SAH) and negative initial vascular investigation.

Design

Single centre prospective cohort study.

Subjects

All adult patients with SAH admitted to our unit over a 12 month period.

Methods

Prospective collection of data on secure electronic database. Information pertaining to gender, age, mode of initial and subsequent vascular investigations was acquired. Details regarding clinical outcomes at 30 days and complications were documented.

Results

118 consecutive patients with SAH were admitted to our unit over the 12 month study period. 37 patients had negative initial vascular imaging (37/118=31.4%). M:F=19:18, age range 26–76 years. 32 patients underwent a high quality CT angiogram as initial vascular investigation, 5 patients underwent catheter cerebral angiogram (DSA). The most common modality of further vascular imaging was DSA. 5 vascular abnormalities were detected on subsequent vascular imaging (5/37=13.5%). Hydrocephalus and vasospasm were the commonest complications. Clinical outcomes were very good; all patients had a GOS of 5 at 30 days.

Conclusions

Patients with SAH and negative initial vascular investigation are an important subset of patients with SAH. There is no uniformity in the type of subsequent vascular investigations selected. Our experience is consistent with previously published studies.

Sociodemographic Factors, Smoking and Common Mental Disorder in the Renfrew and Paisley (MIDSPAN) Study

The relationships between common mental disorder measured by the General Health Questionnaire and sociodemographic variables and cigarette smoking were examined from baseline data in a community study of 15,406 men and women, aged between 45 and 64 years from two towns close to Glasgow. Between 1972 and 1976 all those respondents from Renfrew and Paisley between the ages of 45 and 64 years who met the residency criteria were invited to attend community clinics, where a clinical examination was carried out and the General Health Questionnaire was completed by 3783 (53.6 percent) men, and 4683 (56.1 percent) women. Women had a higher risk of disorder than men did. More women (20.3 percent) than men (15.4 percent) were possible cases of common mental disorder. Women showed a decrease in disorder with age but no apparent trend in men was observed. Marital status was significantly associated with disorder, with the widowed and separated showing especially high rates of psychiatric disorder. Married men, in contrast to married women, had relatively low levels of psychiatric disorder. Both social class and level of deprivation of the area were associated with psychiatric disorder. For both men and women there was a trend in disorder associated with social class; men in social class V had twice the level of psychiatric disorder compared to those in social class II. For women there was a shallow gradient showing higher levels of disorder with lower social class. Smoking habits were also related to psychiatric disorder; never- and exsmokers had relatively low rates of psychiatric disorder whereas, among current smokers, risk of psychiatric disorder, increased with the number of cigarettes smoked, though only for women.

Correlation studies on nitrogen for sunflower crop across the agroclimatic variability

Nitrogen (N) fertilizer is an important yield limiting factor for sunflower production. The correlation between yield components and growth parameters of three sunflower hybrids (Hysun-33, Hysun-38, Pioneer-64A93) were studied with five N rates (0, 60, 120, 180, 240 kg ha(-1)) at three different experimental sites during the two consecutive growing seasons 2008 and 2009. The results revealed that total dry matter (TDM) production and grain yield were positively and linearly associated with leaf area index (LAI), leaf area duration (LAD), and crop growth rate (CGR) at all three sites of the experiments. The significant association of yield with growth components indicated that the humid climate was most suitable for sunflower production. Furthermore, the association of these components can be successfully used to predict the grain yield under diverse climatic conditions. The application of N at increased rate of 180 kg ha(-1) resulted in maximum yield as compared to standard rate (120 kg ha(-1)) at all the experimental sites. In this way, N application rate was significantly correlated with growth and development of sunflower under a variety of climatic conditions. Keeping in view such relationship, the N dose can be optimized for sunflower crop in a particular region to maximize the productivity. Multilocation trails help to predict the input rates precisely while taking climatic variations into account also. In the long run, results of this study provides basis for sustainable sunflower production under changing climate.

Roles of plant growth regulators on yield, grain qualities and antioxidant enzyme activities in super hybrid rice (Oryza sativa L.)

BACKGROUND

Plant growth regulators play important roles in plant growth and development, but little is known about roles of plant growth regulators in yield, grain qualities and antioxidant enzyme activities in super hybrid rice. In this study, gibberellic acid(GA3), paclobutrazol (PBZ), 6-Benzylaminopurine(6-BA) treatments and distilled water (control) were sprayed to two hybrid rice cultivars (Peizataifeng and Huayou 86) at the heading stage in the field experiments in both early and late season in 2007. Treatments were arranged in a split-plot design with four replications. Cultivars treatments with two newly developed super hybrid rice Peizataifeng and Huayou86 were the main plots and plant growth regulators treatments were the subplots. Subplot treatments included (1) plots sprayed with distilled water(CK), (2) plots sprayed with 20 mg L-1 GA3 prepared using 95% ethanol as surfactant(GA3), (3) plots sprayed with 50 mg L-1 PBZ(PBZ), (4) plots sprayed with 30 mg L-1 6-BA(6-BA).

RESULTS

Spraying PBZ with 50 mg L-1 or 6-BA with 30 mg L-1 at the heading stage could increase the number of spikelets per panicle, seed setting rate and grain yields in Peizataifeng and Huayou86 in both seasons. PBZ treatment also significantly improved head rice rate and amylose content in Peizataifeng and Huayou86 in early season. Furthermore, it was observed that spraying PBZ or 6-BA could increase super oxide dismutase (SOD) and peroxidase (POD) activities, decrease accumulation of malendialdehyde (MDA) in flag leaves at the late growth stage.

CONCLUSIONS

Application of PBZ or 6-BA partially alleviated the detrimental effects of rice senescence by modulating the activity of enzymatic antioxidants, and improving antioxidant system, which helped in sustaining plant growth. Therefore, spraying PBZ with 50 mg L-1 or 6-BA with 30 mg L-1 at the heading stage could increase grain yields and improve grain qualities in the two super hybrid rice.

Reduced risk of hospitalisation with risperidone long-acting injectable. Results of the french cohort for the general study of schizophrenia (CGS)

Introduction

Medication non-adherence is a significant risk factor for rehospitalisation in schizophrenia patients. Delayed release formulations like R-LAI may reduce rehospitalisation.

Objectives

To examine the association between R-LAI use and hospitalisation in schizophrenia patients.

Aims

To assess the effect of R-LAI, compared to non-use and use of other antipsychotic drugs, on the risk of hospitalization in real-life settings.

Method

The CGS study recruited schizophrenia patients from 177 public and private wards of psychiatric hospitals across France. Inclusion criteria were schizophrenia (DSM-IV), age 15–65 years, ambulatory/hospitalised for < 93 days at entry. Patients were followed up to 12 months for antipsychotic use and hospitalisation. The recruitment was stratified for long-acting second generation antipsychotic use. Multivariate Poisson regression adjusted for confounding with propensity scores and allowing for autocorrelation was used to estimate relative rates of hospitalisation.

Results

Of 2092 eligible patients, 1859 were included. Their mean age was 38.1 ± 11.1 years, 68.6% were male and 37.8% were hospitalised for < 93 days at entry. A total of 1659 patients (89.2%) were followed up for 12 months, accumulating 933 hospital stays (53.0 per 100 person-years). Compared to other schizophrenia patients, patients on R-LAI were younger, had more often a history of previous hospitalisation for equivalent severity, living conditions and other characteristics. The adjusted relative rate of hospitalisation for R-LAI use against non-use was 0.66 [95% CI 0.46–0.96], and 0.53 [95% CI 0.32–0.88] against long-acting first generation antipsychotics.

Conclusions

Use of R-LAI was associated with lower rates of hospitalization compared to non-use of R-LAI.

Psychological distress, physical illness and risk of myocardial infarction in the Caerphilly study

BACKGROUND

Studies have found associations between psychological distress (PD) and increased risk of myocardial infarction (MI). However, it is not clear whether the relationship reflects the subtle influence of pre-existing illness on both PD and MI. This study examines the association between PD and MI in a prospective epidemiological study of 1864 middle-aged men to examine if the association is explained by existing illness.

METHOD

This study was a prospective cohort study modelling the association between PD, measured using the 30-item General Health Questionnaire (GHQ) and non-fatal myocardial infarction (NFMI) and fatal/non-fatal myocardial infarction (FNFMI). The relationship was modelled in a series of logistic regression models adjusted for age, then cigarette smoking, then social position, and finally for all sociodemographic characteristics, coronary heart disease (CHD) risk factors, and baseline CHD.

RESULTS

PD was associated with a 70% and 68% increased risk of NFMI and FNFMI in fully adjusted analysis. However, PD was not associated with an increased risk of NFMI and FNFMI in analyses excluding those with baseline CHD. Further, being psychologically distressed and physically ill was associated with a greater than twofold risk of NFMI and FNFMI, 2.37 (95% CI 1.33-4.20) and 2.33 (95% CI 1.32-4.12) respectively.

CONCLUSIONS

This study suggests that PD is a moderator of the increased risk of MI associated with existing physical illness. PD in men who are physically ill is a marker of an underlying chronic physical illness. The prospective association of PD with MI is not independent of baseline physical illness.

Psychological distress, physical illness, and risk of coronary heart disease

STUDY OBJECTIVE

The aims of this study are to confirm the association between psychological distress and coronary heart disease (CHD) using an epidemiological community study with hospital admissions data and to examine if any association is explained by existing illness.

DESIGN

Prospective cohort study modelling the association between psychological distress, measured using the 30 item general health questionnaire (GHQ), and hospital admissions data for CHD (ICD 410-414), using proportional hazards modelling adjusted for sociodemographic, CHD risk factors, and angina, bronchitis, diabetes, ischaemia, and stroke.

SETTING

Two suburbs of Glasgow, Renfrew and Paisley, in Scotland.

PARTICIPANTS

6575 men and women aged 45-64 years from Paisley.

MAIN RESULTS

Five year CHD risk in distressed men compared with non-distressed men was 1.78 (95% confidence intervals (CI), 1.15 to 2.75) in age adjusted analysis, 1.78 (95% CI, 1.14 to 2.79) with sociodemographic and CHD risk factor adjustment, and 1.61 (95% CI 1.02 to 2.55) with additional adjustment for existing illness. Psychological distress was unrelated to five year CHD risk in women. In further analysis, compared with healthy, non-distressed men, distressed physically ill men had a greater risk of CHD than non-distressed physically ill men, a relative risk of 4.01 (95% CI 2.42 to 6.66) compared with 2.12 (95% CI 1.35 to 3.32).

CONCLUSION

The association of psychological distress with an increased risk of five year CHD risk in men could be a function of baseline physical illness but an effect independent of physical illness cannot be ruled out. Its presence among physically ill men greatly increases CHD risk.

Gender differences in self-reported minor mental disorder and its association with suicide. A 20-year follow-up of the Renfrew and Paisley cohort

BACKGROUND

Suicide rates are around three times higher in men than women; in contrast women have a higher prevalence of community-diagnosed depression. To investigate this paradox we examined the association of General Health Questionnaire (GHQ)-caseness (score > or = 4), a measure of possible minor mental disorder, with suicide risk in a general population cohort.

METHODS

Data were derived from a cohort study based on the 8,466 men and women in the Renfrew and Paisley cohort who completed a 30-item GHQ in the period from 1972 to 1976 and who were followed up to 1995 for all-cause and suicide mortality.

RESULTS

The long-term suicide risk associated with possible minor mental disorder was higher in men [hazard ratio 6.78 (1.36-33.71)] than women [hazard ratio 1.66 (0.43-6.45)]; test for interaction between gender and GHQ with respect to suicide risk: p = 0.09.

CONCLUSION

These findings indicate either that the long-term risk of suicide in the context of a past episode of minor mental disorder is higher in males than females or that there are sex differences in the validity of responses to mental health screening questionnaires. Further research is required to replicate our finding in larger studies and, if confirmed, clarify which explanation underlies it.