Environmental information systems in malaria risk mapping and epidemic forecasting

Every year between one and two million African children under five die of malaria. If one adds to this the contribution of malaria to all-cause infant mortality then clearly the burden of the disease is catastrophic--a disaster quietly happening each and every year. New tools are needed urgently to support those currently available for control of the disease. An effective vaccine remains elusive. This article outlines the potential contribution to malaria control services of satellite information, which is being used by resource managers in other sectors. In particular, it highlights the lessons which can be learned from early warning systems in other areas, especially those designed to respond to famine. An appendix provides a brief introduction to satellite data and their interpretation.     

Cloning and functional characterisation of two novel nicotinic acetylcholine receptor alpha subunits from the insect pest Myzus persicae

Nicotinic acetylcholine receptors play a major role in excitatory neurotransmission in insect CNSs and constitute an important target for insecticides. Here, we report the isolation and functional characterisation of two cDNAs encoding nicotinic acetylcholine receptor alpha subunits from a major insect pest, the peach-potato aphid Myzus persicae. These two subunits, termed Mp alpha1 and Mp alpha2, are respective structural homologues of the Drosophila D alpha2/Schistocerca gregaria alphaL1 alpha-subunit pair and the Drosophila ALS alpha subunit. Xenopus oocyte expression confirmed that each Myzus subunit can form functional acetylcholine- or nicotine-gated channels. However, some electrophysiological and pharmacological properties of the Myzus subunits were distinct from those encoded by the corresponding Drosophila subunits. Coexpression of the Myzus subunits with the chick beta2 subunit revealed other differences from the Drosophila system, as only very limited potentiation of agonist-induced currents was observed with Mp alpha2 and none with Mp alpha1. Available data therefore indicate that structurally homologous insect nicotinic acetylcholine receptor alpha subunits from different species can exhibit distinctive physiological and pharmacological characteristics.     

Quality of life and productivity in nurses reporting migraine

Calcium phosphate bone cements (CPBCs) are osteotransductive, i.e. after implantation in bone they are transformed into new bone tissue. Furthermore, due to the fact that they are mouldable, their osteointegration is immediate. Their chemistry has been established previously. Some CPBCs contain amorphous calcium phosphate (ACP) and set by a sol-gel transition. The others are crystalline and can give as the reaction product dicalcium phosphate dihydrate (DCPD), calcium-deficient hydroxyapatite (CDHA), carbonated apatite (CA) or hydroxyapatite (HA). Mixed-type gypsum-DCPD cements are also described. In vivo rates of osteotransduction vary as follows: gypsum-DCPD > DCPD > CDHA approximately CA > HA. The osteotransduction of CDHA-type cements may be increased by adding dicalcium phosphate anhydrous (DCP) and/or CaCO3 to the cement powder. CPBCs can be used for healing of bone defects, bone augmentation and bone reconstruction. Incorporation of drugs like antibiotics and bone morphogenetic protein is envisaged. Load-bearing applications are allowed for CHDA-type, CA-type and HA-type CPBCs as they have a higher compressive strength than human trabecular bone (10 MPa).     

Relations of cigarette smoking and dietary antioxidants with placental calcification

The purpose of this study was to evaluate the diagnostic efficacy of the double inversion recovery fast spin echo (DIR-FSE) sequence for brain imaging compared to the fluid-attenuated inversion recovery (FLAIR) sequence. DIR-FSE and FLAIR-FSE sequences were obtained and compared side by side. Image assessment criteria included lesion conspicuity, contrast between different types of normal tissue, image quality, and artifacts. In addition, contrast ratios and contrast-to-noise ratios were determined. Scan time of DIR-FSE was 33% longer than scan time of FLAIR-FSE. Overall lesion conspicuity was equal on DIR-FSE and FLAIR-FSE; however, DIR-FSE showed particular advantages for infratentorial lesions and lesions with only poor contrast on T2-weighted images, whereas FLAIR was slightly superior for small superficial cerebral abnormalities. Gray-white differentiation was better with DIR-FSE. Cerebrospinal fluid suppression was equal on both sequences; cerebrospinal fluid pulsation artifacts were more pronounced on DIR-FSE but did not cause diagnostic difficulties on these images. We conclude that DIR-FSE might be obtained if infratentorial lesions and abnormalities with only slightly prolonged T2 relaxation times are suspected. Otherwise, FLAIR-FSE seems preferable.     

Effects of gastric mucosal blood flow (GMBF) on the role of adaptive cytoprotection of rat gastric mucosa

It has been reported that ingestion of an ammonium-containing diet produces hyperammonemia without encephalopathy, thus permitting the study of the specific effects of ammonia toxicity. The present study investigated the rat cerebral somatostatinergic system using this experimental model of hyperammonemia. Wistar rats were fed a high ammonia diet prepared by mixing a standard diet with ammonium acetate (20% w/w); in addition, 5 mM of ammonium acetate was added to their water supply. Control rats were fed with a standard diet. The animals were sacrificed at 3, 7 and 15 days of ammonia ingestion. Ammonia levels in blood had increased approximately 3-fold at 7 days of ammonia ingestion. These changes were associated with a significant decrease in the specific binding of somatostatin (SS) to putative receptors sites in the frontoparietal cortex and hippocampus at 7 and 15 days after starting the high ammonia diet. Scatchard analysis shows that the decrease in SS binding resulted from a decrease in the number of available SS receptors rather than a change in receptor affinity. No changes in the somatostatin-like immunoreactivity content (SSLI) were detected in either brain area at the three study times. These results suggest that hyperammonemia alone can affect the rat brain somatostatinergic system. However, the animal model of hyperammonemia used here is insufficient to produce encephalopathy despite the significant increase in serum ammonia.     

The ribonucleotide reductase inhibitor (E)-2''-fluoromethylene-2''-deoxycytidine (MDL 101,731): a potential topical therapy for herpes simplex virus infection

Recent advances in diagnosis, treatment, and tumor biology of the lymphoid blastic malignancies have challenged historical concepts and created a need for revised classification of these diseases. The authors review this material and present a classification relevant to current therapeutic protocols and available biological data. Further advances in understanding of these diseases can be anticipated, with possible further evolution of classification. The exact clinical role of sensitive studies to monitor residual disease during and after treatment remains to be established. These diseases may present difficult differential diagnostic problems. The importance of accurate diagnosis cannot be overemphasized, as highly successful but divergent treatments have evolved for these various hematopoietic diseases. Diagnostic problems are usually resolved with systematic analysis including careful morphology, cytochemistry, immunologic analysis, and addition of EM and other studies in selected circumstances.