Report of an NIAID workshop on dengue animal models

Dengue is a mosquito-borne viral disease of humans that has re-emerged in many parts of the world and has become an important international public health threat. Dengue incidence and geographical spread has dramatically increased in the last few decades and is now affecting most tropical and sub-tropical regions of the world. Despite extensive research efforts for several decades, no vaccines or therapeutics are currently available to prevent and treat dengue infections. One of the main obstacles to the development of countermeasures has been the lack of good animal models that recapitulate dengue pathogenesis in humans and reliably predict the safety and efficacy of countermeasures against dengue. In September 2008, the National Institute of Allergy and Infectious Diseases (NIAID) held a workshop to consider the current state-of-the-art developments in animal models for dengue and discuss strategies to accelerate progress in this field. This report summarizes the main discussions and recommendations that resulted from the meeting.

Description of a new species of Culex (Lophoceraomyia) from Orissa, India

Female and male adults, male genitalia, pupae, and larvae of Culex (Lophoceraomyia) singhbhumensis, a new mosquito species, are described from Orissa, India.

Studies on the extraction of uranium by N-octanoyl-N-phenylhydroxamic acid

N-octanoyl-N-phenylhydroxamic acid (OHA) has been prepared by partial reduction of nitrobenzene with Zn dust/NH4Cl, followed by acylation with n-octanoyl chloride. Structure of OHA was confirmed by 1H NMR, IR spectra and CHNS microanalysis. The extraction of uranium by OHA has been studied as a function of pH, temperature and concentration of OHA. The extraction of uranium was found to increase with increase in pH. Uranium forms a 1:2 complex with OHA. IR Spectra & NMR Spectra of the uranium-OHA complex and slope analysis obtained from extraction studies indicated that the extraction of uranium was due to the formation of a chelate. The enthalpy change accompanied by the extraction of uranium by OHA has been obtained by temperature variation method. The extraction process was found to be endothermic at pH 2 and exothermic at pH 6.

Vitamin B6 status in patients with cancer of the uterine cervix

The activities of aspartate aminotransferase and alanine aminotransferase in erythrocytes with and without the addition of pyridoxal phosphate were determined in healthy controls and in Indian women with cancer of the uterine cervix. The percent stimulation of the erythrocyte transferases as a result of the addition of pyridoxal phosphate was negligible in the case of normal subjects (less than 5% stimulation). In the patients with cervical cancer, a 23-35% stimulation was observed, indicating a deficiency of vitamin B6. It is not yet known whether the deficiency is the cause of the disease or due to the tumor.

White-out from a Wii: traumatic haemothorax sustained playing Nintendo Wii

A case is reported of a patient who sustained a significant haemothorax while playing with a Nintendo Wii console.

Mosquitoes of the mangrove forests of India: part 7--an overview

Parts 1 to 6 of this series on the mosquitoes of the mangrove forests of India dealt with the mosquito species recorded in the mangroves of Bhitarkanika, Sundarbans, Andaman and Nicobar islands, Coringa, Chorao and Vikhroli, and Kundapur and Kannur. This concluding part provides an overview of the distribution of the mosquito species in different mangrove forests, including the mangroves of Muthupet in Tamilnadu and the mangroves of Gulf of Kutch and Gulf of Kambhat in Gujarat, species collected as larvae, species in relation to the salinity of the larval habitats, species landing on humans for feeding in the mangroves, and the impact of habitat degradation on species diversity.

Thermal decomposition of expanded polystyrene in a pebble bed reactor to get higher liquid fraction yield at low temperatures

Expanded polystyrene is one of the polymers produced in large quantities due to its versatile application in different fields. This polymer is one of the most intractable components in municipal solid waste. Disposal of polymeric material by pyrolysis or catalytic cracking yields valuable hydrocarbon fuels or monomers. Literature reports different types of reactors and arrangements that have uniform temperatures during pyrolysis and catalytic cracking. The present study focuses on reducing the temperature to maximize the quantity of styrene monomer in the liquid product. A bench scale reactor has been developed to recover the styrene monomer and other valuable chemicals. Experiments were carried under partial oxidation and vacuum conditions in the temperature range of 300-500 degrees C. In the pyrolysis optimization studies, the best atmospheric condition was determined to be vacuum, the pyrolysis temperature should be 500 degrees C, yield of liquid product obtained was 91.7% and yield of styrene obtained was 85.5%. In the characterization studies, distillation and IR spectroscopy experiments were carried out. The remaining of the liquid product comprises of benzene, ethyl benzene, and styrene dimers and trimers.

LR-90 prevents dyslipidaemia and diabetic nephropathy in the Zucker diabetic fatty rat

AIMS/HYPOTHESIS

Previous studies have shown that LR-90, a new inhibitor of AGE formation, prevented the development of experimental type 1 diabetic nephropathy. In this study, we examined the effects of LR-90 in the Zucker diabetic fatty (ZDF) rat, a model of type 2 diabetes and metabolic syndrome, and investigated the mechanisms by which it may protect against renal injury.

METHODS

Male ZDF rats were treated without or with LR-90 from age 13 to 40 weeks. Metabolic and kidney functions and renal histology were evaluated. AGE accumulation and the production of the receptor for AGE (AGER) were measured. Profibrotic growth factors, extracellular matrix proteins and intracellular signalling pathways associated with glomerular and tubular damage were also analysed.

RESULTS

LR-90 dramatically reduced plasma lipids in ZDF rats, with only modest effects on hyperglycaemia. Renal AGE, AGER and lipid peroxidation were all attenuated by LR-90. LR-90 significantly retarded the increase in albuminuria and proteinuria. This was associated with reduction in glomerulosclerosis and tubulointerstitial fibrosis, concomitant with marked inhibition of renal overproduction of TGF-beta1, connective tissue growth factor, fibronectin and collagen IV. Additionally, LR-90 downregulated the activation of key mitogen-activated protein kinases (MAPKs) and nuclear factor kappa B (NF-kappaB) in the renal cortex.

CONCLUSIONS/INTERPRETATION

These results support our earlier studies on the renoprotective effects of LR-90 on type 1 diabetic nephropathy and provide further evidence that LR-90, an AGE inhibitor with pleiotrophic effects, may also be beneficial for the prevention of type 2 diabetic nephropathy, where multiple risk factors, such as hyperglycaemia, dyslipidaemia, obesity, insulin resistance and hypertension, contribute to renal injury.

Mosquitoes of the mangrove forests of India: part 5--Chorao, Goa, and Vikhroli, Maharashtra

Mosquitoes of 14 species belonging to 9 subgenera and 9 genera were recorded in Chorao mangroves of Goa, and 12 species belonging to 9 subgenera and 7 genera in the mangroves of Vikhroli, Maharashtra, in India. Genera recorded were Aedes, Anopheles, Armigeres, Culex, Mansonia, Ochlerotatus, Orthopodomyia, Toxorhynchites, Uranotaenia, and Verrallina. Species common to both the mangroves were Ae. albopictus, Ae. novalbopictus, An. subpictus, Cx. sitiens, Oc. wardi, Ur. atra, and Ve. lugubris. Tree holes, crab holes, and swamp pools were the common larval habitats in Chorao, but tree holes were absent in Vikhroli. Adults of Ae. albopictus, Ae. novalbopictus, Ar. subalbatus, Cx. gelidus Cx. sitiens, Ma. indiana, Ur. atra, and Ve. lugubris were found landing on humans. Aedes novalbopictus, Oc. wardi, and Or. anopheloides are new records for the state of Goa.

Three dimensional structure-activity relationships (3D-QSAR) for insect repellency of diastereoisomeric compounds: a hierarchical molecular overlay approach

2-(2-Hydroxyethyl)-1-piperidinecarboxylic acid 1-methylpropyl ester (Picaridin), and 1-(cyclohex-3-ene-1-ylcarbonyl)-2-methylpiperidine (AI3-37220; 220) are alternatives to DEET (N,N-diethyl-3-methylbenzamide), the most popular mosquito repellent. Picaridin and AI3-37220 exhibit polychiral diastereoisomerism and each has four diastereoisomers due to the presence of two asymmetric centers in their molecules. The diastereoisomers of these compounds have differing degrees of mosquito-repellent activity according to quantitative behavioral assays conducted at the United States Department of Agriculture. An insight into the stereochemical requirements for repellency is of great importance in the development of better repellents. Molecular overlay of the optimized geometries of the diastereoisomers was considered as a novel tool for Stereochemical Structure-Activity Relationship (SSAR) modeling. An earlier study using molecular mechanics (MM2) optimized geometries showed good promise. In continuation of this effort and to overcome certain defects in using MM2 geometries, a hierarchical overlay approach was developed. In this method geometry of the low energy conformer of each diastereoisomer was optimized using: the following quantum chemical methods in a graduated manner: (a) semiempirical AM1, (b) Hartree Fock (STO3G, 3-21G, 6-31G, and 6-311G), and (c) Density Functional Theory (B3LYP/6-31G, B3LYP/6-311G). The optimized geometries of different diastereoisomers were overlaid in various user defined combinations to calculate the root mean square distances (RMSD) of the overlaid structures. The RMSD with respect to the most active diastereoisomer (220SS) were found to have a strong relationship with biological potency. Common motifs in shapes and molecular surfaces that are probably critical for effective repellent activity were identified. The hierarchical approach gave valuable information on the quantum chemical level (basis set) at which optimization must be carried out to get the correct order of repellency of the diastereoisomers of Picaridin and 220.

DNA barcodes can distinguish species of Indian mosquitoes (Diptera: Culicidae)

Species identification of mosquitoes (Diptera: Culicidae) based on morphological characteristics remains often difficult in field-collected mosquito specimens in vector-borne disease surveillance programs. The use of DNA barcodes has been proposed recently as a tool for identification of the species in many diverse groups of animals. However, the efficacy of this tool for mosquitoes remains unexplored. Hence, a study was undertaken to construct DNA barcodes for several species of mosquitoes prevalent in India, which included major vector species. In total, 111 specimens of mosquitoes belonging to 15 genera, morphologically identified to be 63 species, were used. This number also included multiple specimens for 22 species. DNA barcode approach based on DNA sequences of mitochondrial cytochrome oxidase gene sequences could identify 62 species among these, in confirmation with the conventional taxonomy. However, two closely related species, Ochlerotatus portonovoensis (Tiwari & Hiriyan) and Ochlerotatus wardi (Reinert) could not be identified as separate species based on DNA barcode approach, their lineages indicating negligible genetic divergence (Kimura two-parameter genetic distance = 0.0043).

DNA barcodes can distinguish species of Indian mosquitoes (Diptera: Culicidae)

Species identification of mosquitoes (Diptera: Culicidae) based on morphological characteristics remains often difficult in field-collected mosquito specimens in vector-borne disease surveillance programs. The use of DNA barcodes has been proposed recently as a tool for identification of the species in many diverse groups of animals. However, the efficacy of this tool for mosquitoes remains unexplored. Hence, a study was undertaken to construct DNA barcodes for several species of mosquitoes prevalent in India, which included major vector species. In total, 111 specimens of mosquitoes belonging to 15 genera, morphologically identified to be 63 species, were used. This number also included multiple specimens for 22 species. DNA barcode approach based on DNA sequences of mitochondrial cytochrome oxidase gene sequences could identify 62 species among these, in confirmation with the conventional taxonomy. However, two closely related species, Ochlerotatus portonovoensis (Tiwari & Hiriyan) and Ochlerotatus wardi (Reinert) could not be identified as separate species based on DNA barcode approach, their lineages indicating negligible genetic divergence (Kimura two-parameter genetic distance = 0.0043).

Mosquitoes of the mangrove forests of India: part four--Coringa, Andhra Pradesh

Mosquitoes of 12 species belonging to 5 subgenera and 9 genera--Aedes, Anopheles, Culex, Diceromyia, Lorrainea, Rhinoskusea, Stegomyia, Toxorhynchites, and Verrallina--were recorded in the Coringa mangrove forest in Andhra Pradesh, India. Tree holes, crab holes, and swamp pools constituted the larval habitats with Lo. fumida being predominant in tree holes. Adults were found resting in tree holes, tree trunks, root bases, and in crab holes. Species involved in daytime feeding on humans were Ae. cancricomes, Cx. sitiens, Lo. fumida, Rh. wardi, and Ve. lugubris.

Mosquitoes of the mangrove forests of India: part six--Kundapur, Karnataka and Kannur, Kerala

Mosquitoes of 26 species belonging to 16 subgenera and 11 genera were recorded in the Kundapur mangroves of Karnataka, and 17 species belonging to 11 subgenera and 7 genera were recorded in the mangroves of Kannur, Kerala along the west coast of India. Genera recorded were Aedes, Anopheles, Armigeres, Culex, Heizmannia, Lutzia, Mansonia, Ochlerotatus, Tripteroides, Uranotaenia, and Verrallina. Species common to both mangrove forests were Ae. albopictus, Ae. vittatus, An. jamesi, Ar. subalbatus, Cx. gelidus, Cx. infantulus, Cx. pseudovishnui, Cx. sitiens, Cx. tritaeniorhynchus, Oc. wardi, Ur. atra, and Ve. luguhris. Tree holes and swamp pools were the common larval habitats, with more species occurring in tree holes in Kundapur than in Kannur. Adults of Ae. albopictus, Ae. vittatus, Ar. aureolineatus, Ar. subalbatus, Cx. bitaeniorhynchus, Cx. sitiens, Ma. uniformis, and Ve. lugubris bloodfed on humans.

Mosquitoes of the mangrove forests of India: Part 3--Andaman and Nicobar Islands, including an update on the mosquito fauna of the islands

ABSTRACT. Fifty-three mosquito species belonging to 20 subgenera and 18 genera--Aedes, Anopheles, Armigeres, Culex, Downsiomyia, Finlaya, Heizmannia, Kenknightia, Lorrainea, Lutzia, Ochlerotatus, Orthopodomyia, Rhinoskusea, Stegomyia, Toxorhynchites, Tripteroides, Uranotaenia, and Verrallina--were recorded in the mangroves of Andaman and Nicobar Islands, India, in collections made during May and June 2001. Larvae of 43 species were collected from different mangrove habitats. Together with collections made in nonmangrove areas, 83 species in 22 subgenera and 20 genera in total were recorded of which 33 species are new records for the Andaman and Nicobar Islands. Rhinoskusea wardi, Fl. flavipennis, and Ve. consonensis are 3 new country records for India. Collections included topotype specimens of St. seampi. Together with species known from earlier records, the mosquito fauna of Andaman and Nicobar Islands is updated to 107 species in 23 subgenera and 24 genera.

Relationship between 12/15-lipoxygenase and COX-2 in mesangial cells: potential role in diabetic nephropathy

The 12/15-lipoxygenase (12/15-LO) and cyclooxygenase-2 (COX-2) pathways of arachidonate metabolism have been implicated in the pathogenesis of diabetic nephropathy (DN). In this study, we evaluated whether there is an interplay between 12/15-LO and COX-2 pathways in mesangial cells (MC). We utilized MC, microdissected glomeruli and renal cortical tissues. Transfections with cDNAs or short hairpin RNAs (shRNAs) were performed to overexpress or knockdown 12/15-LO and COX-2, respectively. Reverse transcription-polymerase chain reactions and Western blotting were used for evaluating mRNA and protein expression, respectively. We observed that the expression of both 12/15-LO and COX-2 were increased in high glucose stimulated rat MC relative to normal glucose, and also in cortical tissues from diabetic db/db and streptozotocin-injected mice relative to corresponding control mice. Treatment of rat MC with the 12/15-LO product, 12(S)-hydroxyeicosatetraenoic acid (12(S)-HETE), significantly increased COX-2 expression as well as levels of the COX-2 product, prostaglandin E(2) (PGE(2)). Interestingly, treatment of rat MC with PGE(2) led to a reciprocal increase in 12/15-LO expression as well as levels of 12(S)-HETE. The 12/15-LO shRNA could significantly attenuate COX-2 protein expression and vice versa. Furthermore, COX-2 expression levels were lower in MC and glomeruli from 12/15-LO knockout mice relative to control. Conversely, mouse MC stably overexpressing 12/15-LO had greater levels of COX-2 expression relative to mock-transfected cells. These new results indicate for the first time that 12/15-LO and COX-2 pathways can cross-talk and activate each other in MC. These novel interactions may amplify their effects on the progression of DN.

Glucose and diabetes: effects on podocyte and glomerular p38MAPK, heat shock protein 25, and actin cytoskeleton

Phosphorylated p38 (pp38) mitogen-activated protein kinase (MAPK) regulates heat shock protein 25 (HSP25), stabilizing fibrillar actin (FA) and preventing cleavage to G-actin (GA). Cultured podocytes (Pods) were exposed to glucose (5.5-50 mM)+/-p38MAPK inhibitor SB202190 (SB) or control SB202474 to assess the effects on FA/GA and Pod structure. The relationship of p38MAPK with in vivo Pod structure and albuminuria (Ualb) was assessed in rats with streptozotocin (SZ)-induced diabetes (DM) for 1 week, 1 month, and 4 months. High glucose induced concentration-dependent increases in pp38MAPK and phosphorylated HSP25 (pHSP25) maintained actin cytoskeleton. Inhibition by SB diminished pp38MAPK and pHSP25, decreased FA/GA, and altered FA and GA immunohistochemical appearance. In SZ-DM, glomerular pp38MAPK and biphosphorylated HSP25 were increased after 1 week, declining at 1 month, and at or below C values at 4 months. Glomerular FA/GA in DM was normal at 1 week, declining at 1 month, and low at 4 months. Ualb/creatinine was similar in DM vs C at 1 week, and increased at 1 and 4 months. Morphometry demonstrated progressively diminishing slit pore density in DM over time, denoting evolving effacement. There were strong correlations between slit membrane density and both glomerular biphosphorylated HSP25 and ln Ualb/cr ratio. The data suggest that increased pp38MAPK and pHSP25 comprise an acute adaptation to glycemic stress. Later depletion of DM may contribute to Pod structural alterations and Ualb.

A mosquito-specific protein family includes candidate receptors for malaria sporozoite invasion of salivary glands

We describe a previously unrecognized protein family from Aedes and Anopheles mosquitoes, here named SGS proteins. There are no SGS homologues in Drosophila or other eukaryotes, but SGS presence in two mosquito genera suggests that the protein family is widespread among mosquitoes. Ae. aegypti aaSGS1 mRNA and protein are salivary gland specific, and protein is localized in the basal lamina covering the anatomical regions that are preferentially invaded by malaria sporozoites. Anti-aaSGS1 antibodies inhibited sporozoite invasion into the salivary glands in vivo, confirming aaSGS1 as a candidate sporozoite receptor. By homology to aaSGS1 we identified the complete complement of four SGS genes in An. gambiae, which were not recognized in the genome annotation. Two An. gambiae SGS genes display salivary gland specific expression like aaSGS1. Bioinformatic analysis predicts that SGS proteins possess heparin-binding domains, and have among the highest density of tyrosine sulphation sites of all An. gambiae proteins. The major sporozoite surface proteins (CS and TRAP) also bind heparin, and interact with sulphoconjugates during liver cell invasion. Thus, we speculate that sporozoite invasion of mosquito salivary glands and subsequently the vertebrate liver may share similar mechanisms based on sulphation. Phylogenomic analysis suggests that an SGS ancestor was involved in a lateral gene transfer.