Diversity of Dicotyledenous-Infecting Geminiviruses and Their Associated DNA Molecules in Southern Africa,Including the South-West Indian Ocean Islands

The family Geminiviridae comprises a group of plant-infecting circular ssDNA viruses that severely constrain agricultural production throughout the temperate regions of the world, and are a particularly serious threat to food security in sub-Saharan Africa. While geminiviruses exhibit considerable diversity in terms of their nucleotide sequences, genome structures, host ranges and insect vectors, the best characterised and economically most important of these viruses are those in the genus Begomovirus. Whereas begomoviruses are generally considered to be either monopartite (one ssDNA component) or bipartite (two circular ssDNA components called DNA-A and DNA-B), many apparently monopartite begomoviruses are associated with additional subviral ssDNA satellite components, called alpha- (DNA-αs) or betasatellites (DNA-βs). Additionally, subgenomic molecules, also known as defective interfering (DIs) DNAs that are usually derived from the parent helper virus through deletions of parts of its genome, are also associated with bipartite and monopartite begomoviruses. The past three decades have witnessed the emergence and diversification of various new begomoviral species and associated DI DNAs, in southern Africa, East Africa, and proximal Indian Ocean islands, which today threaten important vegetable and commercial crops such as, tobacco, cassava, tomato, sweet potato, and beans. This review aims to describe what is known about these viruses and their impacts on sustainable production in this sensitive region of the world.     

The association of type D personality with quality of life in patients with Parkinson's disease

Objectives: Personality traits appear as determinants of quality of life (QoL) in most chronic diseases. Type D personality is characterized by ineffective coping strategies that reduce QoL in patients with coronary heart disease. The aim of this study was to evaluate whether Type D personality also predicts QoL in patients with Parkinson's disease (PD). In addition, gender differences in Type D personalities are explored.

Methods: The sample consisted of 153 PD patients (51.4% males; mean age 67.9 ± 9.3 years). DS-14 was used to measure Type D personality, negative affectivity (NA) and social inhibition (SI). The Parkinson's Disease Quality of Life Questionnaire (PDQ-39) was used to assess QoL, and the Unified Parkinson's Disease Rating Scale (UPDRS) was used to assess functional status. The regression model consisted of disease severity, disease duration, age and DS-14 and its two scales (NA and SI).

Results: Type D is negatively associated with overall QoL in PD patients and most subscales of the PDQ-39. Type D explained emotional well-being in both genders but was significant in the models for stigma, cognition, and communication only in men. NA and SI played a less important role in women in comparison with men.

Conclusion: Type D personality is an important part of the QoL model in PD patients of both genders, especially in the NA scale. The gender differences suggest that male and female PD patients require different coping strategies.     

Broadening the scope on health problems among the chronically neurologically ill with the International Classification of Functioning (ICF)

PURPOSE: The aim of this study was to determine ICF items indicating health problems for patients with a chronic neurological disorder such as multiple sclerosis, Parkinson's disease and neuromuscular disease. METHOD: A Delphi study using three disease-specific panels composed of patients and proxies, medical and non-medical health professionals (N = 98). Panels were asked to select items from the International Classification of Functioning, Disability and Health (ICF) reflecting relevant disease-specific health problems. Items appraised as relevant by the panel members were compared with items in established measures namely: the Minimal Record of Disability (MRD) and the Disability and Impact Profile (DIP). RESULTS: Sixty-eight ICF items were considered to be the most relevant, and belonged to four ICF domains. No significant differences were found between the appraisal of items by patients/proxies and health professionals. Agreement across the disease panels appeared to be (very) strong. Differences between the three disease-specific panels were found for the 'Body Functions and Structures' domain: consensus was reached by extension of the inclusion criteria. The ICF-item selection covers almost all items of the established measures. The largest contrast was shown in the item selection for the 'participation' and 'environmental factors' domains. CONCLUSIONS: Selected items indicate a broader scope in studying health problems compared with widely used health status measures in neurology, especially for the ICF domains 'Participation' and 'Environmental Factors'.     

Phosphatidylinositol 4,5-bisphosphate hydrolysis in turkey erythrocytes is regulated by P2y purinoceptors

When intact [3H]inositol-loaded turkey erythrocytes were stimulated with the purinergic agonist ADP, there was a rapid increase (2.5-fold after 30 sec) in the intracellular content of [3H]inositol 1,4,5-trisphosphate, followed by increases in the levels of [3H]inositol bisphosphate and [3H]inositol 1,3,4,5-tetrakisphosphate (4-fold and 5-fold, respectively, after 3 min). [3H]inositol monophosphate levels did not rise in the first 3 min of ADP stimulation but increased slowly thereafter, demonstrating that the primary response of turkey erythrocytes to purinergic stimulation is hydrolysis of phosphatidylinositol 4,5-bisphosphate. Inositol phosphate accumulation was evoked by a P2y purinoceptor, as indicated by the rank order of potencies of a variety of purinergic agonists. 2-Methylthioadenosine 5'-triphosphate was the most potent agonist tested, with an EC50 value of 0.36 microM. High performance liquid chromatography analysis demonstrated the presence of three distinct inositol tetrakisphosphate isomers in [3H]inositol-loaded turkey erythrocytes, inositol 1,3,4,6-tetrakisphosphate [Ins(1,3,4,5)P4], inositol 1,3,4,6-tetrakisphosphate [Ins(1,3,4,6)P4], and inositol 3,4,5,6-tetrakisphosphate. Prolonged stimulation with adenosine 5'-O-(2-thiodiphosphate), a nonhydrolyzable analogue of ADP, resulted in a 60-fold increase in the level of [3H]Ins(1,3,4,5)P4, whereas a substantial rise in the [3H]Ins(1,3,4,6)P4 fraction was also seen. These results indicate that turkey erythrocytes represent a valuable model system for studies of purinoceptor function as well as fundamental aspects of cell surface receptor-regulated phosphoinositide metabolism.     

Factors affecting seropositivity to human T cell lymphotropic virus type III (HTLV-III) or lymphadenopathy associated virus (LAV) and progression of disease in sexual partners of patients with AIDS.

Fifty four sexual partners of homosexual men with the acquired immune deficiency syndrome (AIDS) were studied, of whom 32 were seropositive and 22 seronegative for human T cell lymphotropic virus type III or lymphadenopathy virus (HTLV-III/LAV) antibody, which showed that repeated exposure by anal intercourse does not necessarily lead to seroconversion. Seropositivity to HTLV-III/LAV was not associated with the absolute number of sexual partners, receptive anal intercourse, or the use of recreational drugs, but was associated with a history of other sexually transmitted diseases (STDs), particularly in the year preceding the patient's initial examination. Acquisition of an STD after the date of last sexual contact with a person with AIDS was strongly associated (p less than 0.001) with the development of persistent generalised lymphadenopathy (PGL). Concurrent or recent STDs would seem to be an important cofactor in developing antibody to HTLV-III/LAV and in the progression of infection from a person being asymptomatic to having PGL.     

GDE1/MIR16 is a glycerophosphoinositol phosphodiesterase regulated by stimulation of G protein-coupled receptors

Previously we identified MIR16 (membrane interacting protein of RGS16) as an integral membrane glycoprotein that interacts with regulator of G protein signaling proteins and shares significant sequence homology with bacterial glycerophosphodiester phosphodiesterases (GDEs), suggesting that it is a putative mammalian GDE. Here we show that MIR16 belongs to a large, evolutionarily conserved family of GDEs with a characteristic putative catalytic domain that shares a common motif (amino acids 92-116) with the catalytic domains of mammalian phosphoinositide phospholipases C. Expression of wild-type MIR16 (renamed GDE1), but not two catalytic domain mutants (E97A/D99A and H112A), leads to a dramatic increase in glycerophosphoinositol phosphodiesterase (GPI-PDE) activity in HEK 293T cells. Analysis of substrate specificity shows that GDE1/MIR16 selectively hydrolyzes GPI over glycerophosphocholine. The GPI-PDE activity of GDE1/MIR16 expressed in HEK 293T cells can be regulated by stimulation of G protein-coupled, alpha/beta-adrenergic, and lysophospholipid receptors. Membrane topology studies suggest a model in which the catalytic GDE domain faces the lumenextracellular space and the C terminus faces the cytoplasm. Our results suggest that by serving as a PDE for GPI with its activity regulated by G protein signaling, GDE1/MIR16 provides a link between phosphoinositide metabolism and G protein signal transduction.     

Broadening the scope on health problems among the chronically neurologically ill with the International Classification of Functioning (ICF)

Purpose. The aim of this study was to determine ICF items indicating health problems for patients with a chronic neurological disorder such as multiple sclerosis, Parkinson's disease and neuromuscular disease.

Method. A Delphi study using three disease-specific panels composed of patients and proxies, medical and non-medical health professionals (N = 98). Panels were asked to select items from the International Classification of Functioning, Disability and Health (ICF) reflecting relevant disease-specific health problems. Items appraised as relevant by the panel members were compared with items in established measures namely: the Minimal Record of Disability (MRD) and the Disability and Impact Profile (DIP).

Results. Sixty-eight ICF items were considered to be the most relevant, and belonged to four ICF domains. No significant differences were found between the appraisal of items by patients/proxies and health professionals. Agreement across the disease panels appeared to be (very) strong. Differences between the three disease-specific panels were found for the ‘Body Functions and Structures’ domain: consensus was reached by extension of the inclusion criteria. The ICF-item selection covers almost all items of the established measures. The largest contrast was shown in the item selection for the ‘participation’ and ‘environmental factors’ domains.

Conclusions. Selected items indicate a broader scope in studying health problems compared with widely used health status measures in neurology, especially for the ICF domains ‘Participation’ and ‘Environmental Factors’.