Spray-induced gene silencing to identify powdery mildew gene targets and processes for powdery mildew control.

Spray-induced gene silencing (SIGS) is an emerging tool for crop pest protection. It utilizes exogenously applied double-stranded RNA to specifically reduce pest target gene expression using endogenous RNA interference machinery. In this study, SIGS methods were developed and optimized for powdery mildew fungi, which are widespread obligate biotrophic fungi that infect agricultural crops, using the known azole-fungicide target cytochrome P450 51 (CYP51) in the Golovinomyces orontii-Arabidopsis thaliana pathosystem. Additional screening resulted in the identification of conserved gene targets and processes important to powdery mildew proliferation: apoptosis-antagonizing transcription factor in essential cellular metabolism and stress response; lipid catabolism genes lipase a, lipase 1, and acetyl-CoA oxidase in energy production; and genes involved in manipulation of the plant host via abscisic acid metabolism (9-cis-epoxycarotenoid dioxygenase, xanthoxin dehydrogenase, and a putative abscisic acid G-protein coupled receptor) and secretion of the effector protein, effector candidate 2. Powdery mildew is the dominant disease impacting grapes and extensive powdery mildew resistance to applied fungicides has been reported. We therefore developed SIGS for the Erysiphe necator-Vitis vinifera system and tested six successful targets identified using the G. orontii-A. thaliana system. For all targets tested, a similar reduction in powdery mildew disease was observed between systems. This indicates screening of broadly conserved targets in the G. orontii-A. thaliana pathosystem identifies targets and processes for the successful control of other powdery mildew fungi. The efficacy of SIGS on powdery mildew fungi makes SIGS an exciting prospect for commercial powdery mildew control.

Comparisons between different elements of reported burden and common mental disorder in caregivers of ethnically diverse people with dementia in Trinidad.

OBJECTIVE: Culture plays a significant role in determining family responsibilities and possibly influences the caregiver burden associated with providing care for a relative with dementia. This study was carried out to determine the elements of caregiver burden in Trinidadians regarding which interventions will provide the most benefit. METHODS: Seventy-five caregivers of patients diagnosed with dementia participated in this investigation. Demographic data were recorded for each caregiver and patient. Caregiver burden was assessed using the Zarit Burden Interview (ZBI), and the General Health Questionnaire (GHQ) was used as a measure of psychiatric morbidity. Statistical analyses were performed using Stata and SPSS software. Associations between individual ZBI items and GHQ-28 scores in caregivers were analyzed in logistic regression models; the above-median GHQ-28 scores were used a binary dependent variable, and individual ZBI item scores were entered as 5-point ordinal independent variables. RESULTS: The caregiver sample was composed of 61 females and 14 males. Caregiver burden was significantly associated with the participant being male; there was heterogeneity by ethnic group, and a higher burden on female caregivers was detected at borderline levels of significance. Upon examining the associations between different ZBI items and the above-median GHQ-28 scores in caregivers, the strongest associations were found with domains reflecting the caregiver's health having suffered, the caregiver not having sufficient time for him/herself, the caregiver's social life suffering, and the caregiver admitting to feeling stressed due to caregiving and meeting other responsibilities. CONCLUSIONS: In this sample, with a majority of female caregivers, the factors of the person with dementia being male and belonging to a minority ethnic group were associated with a greater degree of caregiver burden. The information obtained through the association of individual ZBI items and above-median GHQ-28 scores is a helpful guide for profiling Trinidadian caregiver burden.

The novel cyst nematode effector protein 30D08 targets host nuclear functions to alter gene expression in feeding sites.

Cyst nematodes deliver effector proteins into host cells to manipulate cellular processes and establish a metabolically hyperactive feeding site. The novel 30D08 effector protein is produced in the dorsal gland of parasitic juveniles, but its function has remained unknown. We demonstrate that expression of 30D08 contributes to nematode parasitism, the protein is packaged into secretory granules and it is targeted to the plant nucleus where it interacts with SMU2 (homolog of suppressor of mec-8 and unc-52 2), an auxiliary spliceosomal protein. We show that SMU2 is expressed in feeding sites and an smu2 mutant is less susceptible to nematode infection. In Arabidopsis expressing 30D08 under the SMU2 promoter, several genes were found to be alternatively spliced and the most abundant functional classes represented among differentially expressed genes were involved in RNA processing, transcription and binding, as well as in development, and hormone and secondary metabolism, representing key cellular processes known to be important for feeding site formation. In conclusion, we demonstrated that the 30D08 effector is secreted from the nematode and targeted to the plant nucleus where its interaction with a host auxiliary spliceosomal protein may alter the pre-mRNA splicing and expression of a subset of genes important for feeding site formation.

Adapted Biotroph Manipulation of Plant Cell Ploidy.

Diverse plant biotrophs that establish a sustained site of nutrient acquisition induce localized host endoreduplication. Endoreduplication is a process by which cells successively replicate their genomes without mitosis, resulting in an increase in nuclear DNA ploidy. Elevated ploidy is associated with enhanced cell size, metabolic capacity, and the capacity to differentiate. Localized host endoreduplication induced by adapted plant biotrophs promotes biotroph colonization, development, and/or proliferation. When induced host endoreduplication is limited, biotroph growth and/or development are compromised. Herein, we examine a diverse set of plant-biotroph interactions to identify (a) common host components manipulated to promote induced host endoreduplication and (b) biotroph effectors that facilitate this induced host process. Shared mechanisms to promote host endoreduplication and development of nutrient exchange/feeding sites include manipulation centered on endocycle entry at the G2-M transition as well as yet undefined roles for differentiation regulators (e.g., CLE peptides) and pectin/cell wall modification.

Trinidad and Tobago: A decade of dementia research / Trinidad e Tobago: uma década de pesquisa dementia

In 2003, academic staff members at The University of the West Indies Faculty of Medical Sciences St Augustine Trinidad and Tobago combined their expertise to make strides in Alzheimers and Dementia research in Trinidad and Tobago. Dr. Nelleen Baboolal, Dr. Gershwin Davis and Professor Amanda McRae began developing a project that has produced significant results by examining not only the epidemiology of dementia, but the associated risk factors; caregiver burden and ultimately establishing biomarkers for the disease. This review is an account of our results from a decade of dementia research and how they are contributing toward mitigating the dementia tsunami in Trinidad and Tobago.

Em 2003, os membros da equipe acadêmica da Faculdade de Ciências Médicas St Augustine, da Universidade de West Indies, Trinidad e Tobago, combinaram seus conhecimentos para promover avanços nas pesquisas sobre doença de Alzheimer e demência em Trinidad e Tobago. Dr. Nelleen Baboolal, Dr. Gershwin Davis e Professora Amanda McRae começaram a desenvolver um projeto que tem produzido resultados significativos através da análise não só da epidemiologia da demência, mas também dos fatores de risco associados, sobrecarga do cuidador e, ultimamente, estabelecendo biomarcadores para a doença. Esta avaliação representa um relato de nossos resultados de uma década de pesquisa demência e como eles estão contribuindo para mitigar o tsunami de demência em Trinidad e Tobago.

Trinidad and Tobago: A decade of dementia research.

In 2003, academic staff members at The University of the West Indies Faculty of Medical Sciences St Augustine Trinidad and Tobago combined their expertise to make strides in Alzheimer's and Dementia research in Trinidad and Tobago. Dr. Nelleen Baboolal, Dr. Gershwin Davis and Professor Amanda McRae began developing a project that has produced significant results by examining not only the epidemiology of dementia, but the associated risk factors; caregiver burden and ultimately establishing biomarkers for the disease. This review is an account of our results from a decade of dementia research and how they are contributing toward mitigating the dementia tsunami in Trinidad and Tobago.

Em 2003, os membros da equipe acadêmica da Faculdade de Ciências Médicas St Augustine, da Universidade de West Indies, Trinidad e Tobago, combinaram seus conhecimentos para promover avanços nas pesquisas sobre doença de Alzheimer e demência em Trinidad e Tobago. Dr. Nelleen Baboolal, Dr. Gershwin Davis e Professora Amanda McRae começaram a desenvolver um projeto que tem produzido resultados significativos através da análise não só da epidemiologia da demência, mas também dos fatores de risco associados, sobrecarga do cuidador e, ultimamente, estabelecendo biomarcadores para a doença. Esta avaliação representa um relato de nossos resultados de uma década de pesquisa demência e como eles estão contribuindo para mitigar o tsunami de demência em Trinidad e Tobago.

Assessment of treatment goals attained by patients according to guidelines for diabetes management in primary care centres in North Trinidad.

BACKGROUND: the scientific literature is deficient in studies looking at the achievement of primary care diabetes treatment targets as stipulated by best practice guidelines in the Caribbean. AIMS: assessment of treatment goals attained by patients according to the Caribbean Health Research Council (CHRC)/Pan-American Health Organization (PAHO) guidelines for diabetes management in primary care centres in North Trinidad. The primary interest of this study was the extent to which stated intermediate outcome measures were achieved. Secondarily, process measures and adherence to specific recommendations on pharmacotherapy were evaluated. METHODS: this was a cross-sectional study where 225 patients with diabetes from five primary care centres were interviewed in October and November 2007. Data collected included age, sex, ethnicity, religious background, educational level and duration, diabetes type and duration since diagnosis, the presence of hypertension, current blood pressure, level of physical activity and current medications. Last documented serum cholesterol and HbA1c within the past year were obtained from patient records. Anthropometric measurements recorded were weight, height and waist and hip circumferences. RESULTS: of patients with available values, 49.3% achieved the target total cholesterol of less than 200 mg/dL while 56.6% had an HbA1C level of less than 6.5%. Only 47.7% attained a blood pressure target of less than or equal to 130/80 mmHg. 25.2% had a Body Mass Index (BMI) of less than 25 kg/m(2). For waist circumference measurements, 40.8% of males and 2.1% of females were within recommended limits. Only 13.5% had 20 minutes or more of at least moderate exercise daily. No patient met all recommended target values for these six parameters. CONCLUSIONS: there is poor achievement of treatment goals as set by best practice diabetes management guidelines. Results from this study may serve to inform primary care strategy revisions aimed at more widespread achievement of control targets which would ultimately abate the burden of illness in this population.

Sialic acid, homocysteine and CRP: potential markers for dementia.

To investigate whether sialic acid could discriminate between healthy age matched controls and patients with dementias of the Alzheimer's type (AD), and pure vascular dementia (VaD). 27 patients and 51 controls were administered the Mini-Mental State Examination (MMSE) and had blood analyzed for levels of total sialic acid, total homocysteine (tHcy), and C-reactive protein (CRP). Significant differences were found between the mean MMSE scores for patients with dementia compared with controls. Sialic acid levels were significantly higher in patients with AD compared with controls and homocysteine levels were higher in VaD. Sialic acid levels discriminated between patients with dementia of the Alzheimer's type and healthy controls only. The MMSE could discriminate between controls and patients with dementia but not between the subtypes and homocysteine was significant for patients with VaD.

Adult-onset calorie restriction attenuates kainic acid excitotoxicity in the rat hippocampal slice.

Lifelong calorie restriction is the only known intervention that has been shown to consistently increase life span and reduce the effects of aging on the brain. Given the difficulties of replicating lifelong calorie restriction within human populations, we have sought to assess the effects of short-term adult-onset calorie restriction upon acute excitotoxic insults in the rat hippocampus. Adult animals (approximately 6 months of age) underwent calorie restriction (alternate day feeding) for 7-10 weeks. Utilizing both electrophysiological and immunocytochemical techniques, we report that calorie restriction had no effect upon long-term potentiation (LTP), a measure of neuronal function. In control animals, application of kainic acid (20 microM) resulted in only 35% recovery of CA1 population spikes post-insult. However calorie-restricted animals showed significantly improved recovery after kainic acid treatment (64%). This data was supported by immunocytochemical studies which noted widespread loss of microtubule-associated protein (MAP 2) immunoreactivity in control slices following treatment with kainic acid; however MAP 2 staining was preserved in the CA1 and CA3 regions of calorie-restricted animals. Interestingly there was no significant difference in the recovery of population spikes between groups when slices were treated with N-methyl-d-aspartate (15 microM). We conclude that short-term adult-onset calorie restriction does not alter normal neuronal function and serves to protect the hippocampus from acute kainic acid excitotoxicity.

Potential biomarkers for dementia in Trinidad and Tobago.

Biomarkers that could possibly discriminate between healthy controls and patients with dementias of the Alzheimer's type (AD) and vascular dementia (VaD) were investigated. The Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition TR (DSM IV TR) was used to diagnose for dementia in Trinidad. Healthy seniors greater than 60 years old were controls. All participants were administered the Mini-Mental State Examination (MMSE) and had blood analyzed for levels of C-reactive protein (CRP), total homocysteine (tHcy) and microglial antibodies (MgAb). Plasma tHcy was determined on the Abbot AxSym, serum CRP concentrations were measured using the Tina-Quant sCRP (Latex) high sensitive immunoturbidimetric assay and serum MgAb were examined on frozen rat brain sections. The study was carried out on 29 patients that fulfilled the inclusion criteria and 46 controls. Of the patients 65.5% had AD and 34.5% had VaD. Significant differences were found between the mean MMSE scores of the different types of dementias and controls. MgAb presence as well as tHcy were able to distinguish between controls and dementia of the AD and VaD type, respectively. The MMSE is a good discriminative tool for dementias. Serum MgAbs are a possible biomarker for Alzheimer disease pathology and tHcy is elevated in patients with vascular dementia.

Cerebrospinal fluid antimicroglial antibodies in Alzheimer disease: a putative marker of an ongoing inflammatory process.

Immunocompetent microglia play an important role in the pathogenesis of Alzheimer's disease (AD). Antimicroglial antibodies in the cerebrospinal fluid (CSF) in clinically diagnosed AD patients have been previously recorded. Here, we report the results of the analysis of the CSF from 38 autopsy cases: 7 with definite AD; 14 with mild and 10 with moderate Alzheimer's type pathology; and 7 controls. Antimicroglial antibodies were identified in 70% of patients with definite AD, in 80% of patients with moderate and in 28% of patients with mild Alzheimer's type pathology. CSF antimicroglial antibodies were not observed in any of the control cases. The results show that CSF antimicroglial antibodies are present in the majority of patients with definite AD and also in cases with moderate Alzheimer's type changes. They may also indicate dysregulation of microglial function. Together with previous observations, these findings indicate that compromised immune defense mechanisms play an important role in the pathogenesis of AD.

Gestational stage sensitivity to ultrasound effect on postnatal growth and development of mice.

BACKGROUND: An experiment was conducted to find out whether ultrasound exposure leads to changes in postnatal growth and development in the mouse. METHODS: A total of 15 pregnant Swiss albino mice were exposed to diagnostic levels of ultrasound (3.5 MHz, 65 mW/cm2, I(SPTP) = 1 mW/cm2 Intensity(Spatial Peak-Temporal Peak), I(SATA) = 240 mW/cm2 Intensity(Spatial Average-Temporal Average)) for 30 min for a single day between days 10 and 18 of gestation (GD 10-18). Virgin female mice were placed with same age group males for mating in the ratio 2 females : 1 male and examined the next morning for the presence of vaginal plug, a sign of successful copulation. The females with vaginal plugs were separated and labeled as 0-day pregnant. Maternal vaginal temperature was also measured. A sham exposed control group of 15 pregnant mice was maintained for comparison. All exposed as well as control animals were left to complete gestation and parturition. Their offspring were used in our further studies. They were monitored during early postnatal life for standard developmental markers, postnatal mortality, body weight, body length, head length, and head width, and growth restriction was recorded up to 6 weeks of age. RESULTS: An exposure to ultrasound induced nonsignificant deviations in the maternal vaginal temperature or developmental markers. Significant low birth weight was observed in the present study, after exposure at GD 11, 12, 14, and 16. However, 14 and 16 days postcoitus during the fetal period appears to be the most sensitive to the ultrasound effect, in view of the number of different effects as well as severity of most of the observed effects when exposed on these gestation days. CONCLUSIONS: The results indicate that diagnostic ultrasound can induce harmful effects on mouse growth and development when given at certain critical periods of gestation.

Cerebrospinal fluid and serum antimicroglial antibodies: prospects for early diagnosis of Alzheimer's disease.

The acceptance that chronic inflammation plays a role in the pathogenesis of Alzheimer's disease has widen the window of opportunity for novel therapeutics. The need to establish markers to detect early and preclinical symptoms of Alzheimer's disease is critical as this could allow early intervention. Activated microglia, now considered as the immune cell of the CNS, have gained recognition as participating in the cascade of early events leading to Alzheimer's disease pathology. The serendipitous findings of microglia antibodies in the serum and cerebrospinal fluid of Alzheimer's disease patients could be a means to distinguish Alzheimer's disease patients from other dementias. Further investigations revealing the presence of these particular antibodies in patients at earlier stages suggested that they may be a source to monitor the progression of the disorder. Combining the detection of these antibodies with clinical trials could provide essential feedback about the efficacy of the therapies to interfere with the disease process.

Nerve growth factor levels in Parkinson disease and experimental parkinsonian rats.

Nerve growth factor (NGF) is well established for its ability to promote growth and survival for specific neuronal populations. However, its participation in the pathogenesis of human nervous system disorders such as Parkinson's disease (PD) remains to be resolved. This study examined NGF levels in the serum of healthy persons, in patients with PD and in parkinsonian rats using a double site immune-enzymatic assay (EIA) with the murine 27/21 anti-beta-NGF monoclonal antibody. PD patients were divided in two groups according to the stages of the disease (Grade: I-II and Grade: III-IV of Hoenh and Yahr scale). NGF levels in parkinsonian rats showed significant (P<0.01) reductions when compared with serum from normal animals. The NGF levels in early states of the disease (Grade I-II) showed greater reductions (P<0.01) in comparison to those with advanced stages (Grade III-IV). We consider that alterations in NGF levels may reflect ongoing neurodegenerative processes in PD.

A molecular form of memory protects the brain from the effects of acute hypoxia [abstract]

Long-term potentiation (LTP) is a molecular engram of memory. Previous work has demonstrated that LTP decreases the sensitivity of glutamate receptors in the rat hippocampus. Glutamate has beem implicated in the pathogenesis of hypoxic/ischaemic damage. We therefore tested the hypothesis that LTP could reduce the effects of LTP on hypoxia in the rat hippocampus. The effects of LTP on hypoxia were measured by the changes in the extracellular potentials recorded from the hippocampal slice. Hypoxia was induced by perfusing the slice with artificial cerebrospinal fluid that contained varying concentrations of oxygen. Each slice was initially exposed to the hypoxic medium for 1.5-3.0 minutes. This led to a decrease in the potentials, which recovered to control levels within 5 minutes. Repeat exposure to the same hypoxic medium for the same duration as the first, also caused a reduction in the potentials. There was no significant difference between the degree of reduction caused by the first or second exposure for all types of hypoxic media tested (p >0.05; paired t test). In some slices, LTP was induced after the first hypoxic exposure. LTP brought about an inhibition of the reduction in potentials caused by the second hypoxic insult; the differences in reducation in potentials were highly significant for all the hypoxic media used (p <0.01; paired t test). The neuroprotective effects of LTP were not prevented by cyclothiazide (an inhibitor of AMPA receptor desensitization) or NOS inhibitors (antagonists of intracellular nitric oxide production). These compounds have been shown to be effective in blocking the effects of LTP on the actions of exogenously applied AMPA and NMDA, respectively. The neuroprotective effects of LTP were similar to that of propentofylline, a known neuroprotective compound. We conclude that LTP causes an appreciable protection of the hippocampus slices to in-vitro models of acute hypoxia. There have been reports that there is a possible inverse relationship between educational attainment and the development of dementia and the results of our study may have a role to play in this relationship. (AU)

Gestational stage sensitivity to ultrasound effect on postnatal growth and development of mouse [abstract]

Pregnant Swiss albino mice were exposed to diagnostic ultrasound (3.5 MHz, 65 m W, Isptp= 1 W/cm2, 1sata=240 W/ccm2) for 30 min on any one day from day 10 to 18 gestation. A sham exposed control group was maintained for comparison. A minimum of 15 pregnant mice were exposed in each group. Exposed as well as control animals were left to complete gestation and parturition. Then offspring were observed during early postnatal development for any changes in physiological reflexes like pina detachment, eye opening, fur development, postnatal mortality, body weight, body length, head length and head width up to 6 weeks of age. Ultrasound exposure at any of the gestational age did not have any effect on the timing of onset of the physiological reflexes. But there was a significant change in the postnatal mortality, body weight, body length after exposure to ultrasound on the 14th and 16th day post coitus. Head length and head width also significantly decreased in all the exposed groups when compared to the control. The present study demonstrates that ultrasound can induce harmful effects on mouse growth and development when given at certain critical periods of gestation. (AU)

Local synthesis of IgG subclasses in patients with Alzheimerïs disease

Immunological studies have shown abnormalities of the immune response in several Alzheimerïs disease patients such as the increase of seric IgG3 Eleven Alzheimerïs disease patients were studied. Serum and cerebrospinal fluid were obtained simultaneously. Albumin and IgG subclasses were measured in both biological fluids by simple radial immunodiffusion IgG subclases intrathecal synthesis was were calculated by the improved hyperbolic function and CSF/serum quotient diagram of Reiber. Local IgG subclass synthesis in a varied number of patients were produced. IgG1 was synthesized in 6 patients and IgG2 in 4 patients. Seven patients showed local synthesized IgG3 and 10 patients made IgG4 in central nervous system. No significant alterations were found in the age-related blood brain barrier function. These results support the hypothesis about that an immune-dysregulation and / or autoimmunity mechanism may play an important role in the pathogenesis of the Alzheimerïs disease (AU)

T activation markers from cerebrospinal fluid of Alzheimer's disease patients

It is well known that various markers of the cholinergic synapse are altered in Alzheimer's disease. Nevertheless, the etiology of the neuronal degeneration is unclear. A neuroimmune dysfunction has been considered in some studies indicating the presence of cells related with the IS in affected brain tissue, activation microglial cells and changes in cytokine production. To assess the probable role of activated T cells in the mediation of neuronal damage and neurodegeneration in Alzheimer's disease, we examined the cerebrospinal fluid and peripheral blood of 19 patients diagnosed as "probable AD" and 20 age controls subjects in order to investigate the presence of HLA DR+ and CD 25+ T cells. A significant increase of activated T lymphocyte (p<0,05) was observed in CSF of AD group compared to controls. No association was found between the percentage of activated T cells from both fluids. Our results would enables to omit a hypothesis about an indirect immunological mechanism in CNS of AD which may act to perpetuate the sequence of events involvement in amyloid neurotoxicity and progressive neurodegeneration in this disorder(AU)