La lutte contre l'escargot géant d'Afrique dans l'île de Bugsuk, Philippines, par l'introduction de Platydemus manokwari

Entre 1979 et 1982, la population d'escargots géants d'Afrique (Achatina fulica) a augmenté et a détruit la plante de couverture de 1 600 ha de cocoteraies de l'île de Bugsuk. Les méthodes de contrôle chimiques et mécaniques disponibles se sont révélées inefficaces. L'introduction de la planaire Platydemus manokwari, fin 1981 - début 1982, a permis de réduire en 20 mois de façon significative la population d'escargot

Mangiferin from Salacia chinensis prevents oxidative stress and protects pancreatic β-cells in streptozotocin-induced diabetic rats

Oxidative stress in diabetic tissues is a consequence of free radical accumulation with concurrently impaired natural antioxidants status and results in oxidative tissue damage. The present study investigated the protective effects of mangiferin against pancreatic β-cell damage and on the antioxidant defense systems in streptozotocin (STZ)-induced diabetic rats. Diabetes was experimentally induced by a single intraperitoneal injection of STZ. Oxidative stress biomarkers such as tissue malondialdehyde, hydroperoxides, reduced glutathione (GSH) content, and nonenzymatic antioxidants were measured. Biochemical observations were further substantiated with histological examination and ultrastructural studies in the pancreas of diabetic, glibenclamide and mangiferin-treated diabetic rats (dosage of 40 mg/kg body weight daily for 30 days). Oral administration of mangiferin and glibenclamide to diabetic rats significantly decreased the level of blood glucose and increased levels of insulin. Additionally, mangiferin treatment significantly modulated the pancreatic nonenzymatic antioxidants status (vitamin C, vitamin E, ceruloplasmin, and reduced GSH content) and other oxidative stress biomarkers. The histoarchitecture of diabetic rats showed degenerated pancreas with lower β-cell counts, but mangiferin treatment effectively regenerated insulin secreting islet cells. The electron microscopic study revealed damaged nuclear envelope and mitochondria and fewer secretory granules in pancreas of diabetic rats; however, mangiferin treatment nearly normalized pancreatic architecture. The present findings suggest that mangiferin treatment exerts a therapeutic protective nature in diabetes by decreasing oxidative stress and protecting against pancreatic β-cell damage, which may be attributable to its antioxidative properties

Strong enhancement of two-photon absorption properties in synergic 'semi-disconnected' multiporphyrin assemblies designed for combined imaging and photodynamic therapy.

International audienceThe synthesis and photophysical properties of new multiporphyrin assemblies are described. Their design, based on a smooth electronic disconnection between two-photon absorbing (2PA) octupolar or quadrupolar cores and the peripheral porphyrins, leads to a major increase in (non-resonant) 2PA responses in the NIR, while fully retaining the fluorescence and photosensitization properties of isolated porphyrins. This approach, which involves electronic coupling of semi-disconnected moieties in the higher excited states of the synergic systems, is of interest to fully benefit from the advantages of selective 2PA for application in combined two-photon high resolution imaging and photodynamic therapy

Synthesis, structure and physicochemical properties of a saddle-distorted porphyrin with a peripheral carboxyl group

A saddle-distorted porphyrin bearing a carboxyl group as a hydrogen-bonding site on a meso-phenyl group was synthesized and characterized. A supramolecular structure with intermolecular hydrogen bonding was revealed by X-ray diffraction analysis. The effects of the peripheral carboxyl group on the physicochemical properties of the porphyrin as well as on self-assembly were investigated by spectroscopic measurements in solutions. The redox properties of the porphyrin and its Zn(II) complex were also studied by electrochemical measurements and their application to dye-sensitized solar cells was examined

Porphyrin nanochannels reinforced by hydrogen bonding

Carboxyl groups were introduced at the peripheral positions of dodecaphenylporphyrin to link nanochannel structures with intermolecular hydrogen bonds to make the supramolecular structures robust

Investigation and prediction of urban-sprawl and land-use changes for Chennai city using geo-spatial technologies

1443-1451Monitoring urban sprawl is a vital component to assess landscape changes as it directly affects the quality of life. Multi date land-use and land-cover thematic layers were generated using multi-date high resolution remote-sensing data and Survey of India topo-sheet and spatial changes in urban land-use and urban-sprawl were studied using GIS. The residential and commercial urban area of city increased from 14,865.8 and 2,121.27 hectares in 1991 to 35,564 and 3,527.34 hectares in 2014. This study revealed that 51% of agricultural land and 2% of water bodies have been transformed as other urban land use features, in the form of built-ups. Based on current landscape trends, a 29-year forward simulation for the years 1991 to 2020 was performed using GIS land use change modeller analysis tool. The results show that by 2020 the residential and commercial urban of Chennai would increase to 51,059 and 4,246.7 hectares, respectively

EFFECT OF TRIGONELLA FOENUM GRAECUM ON ΑLPHA-GLUCOSIDASE AND DIPEPTIDYL PEPTIDASE-IV INHIBITORY ACTIVITY - AN IN VITRO STUDY

Objective: The objective of this study is to find the effect of seed extract of Trigonella foenum graecum on the inhibition of α-glucosidase and dipeptidyl peptidase-4 (DPP-4) enzyme activity by in vitro method.Methods: Methanolic seed extract of T. foenum graecum seed was prepared and supplied by Sami Labs, Bengaluru, on request. For alpha-glucosidase inhibition assay, the following concentrations (0, 20, 40, 60, 80, and 100 μg/ml) of extracts and for DPP-4 inhibition assay (0, 5, 10, 20, 40, 80, 160, and 320d μg/ml) concentrations were used. The absorbance was measured at 540 and 405 nm using multiplate reader, and the percentage of α-glucosidase and DPP-4 enzyme inhibitory activity of extract fractions was calculated. Acarbose for alpha-glucosidase inhibition and vildagliptin for DDP-4 inhibition were used as standard drugs. The IC50 value for alpha-glucosidase inhibition and DPP-4 inhibition was determined.Results: The maximum alpha-glucosidase inhibitory activity of T. foenum graecum extract at 100 μg/ml was 68% (p<0.05) with IC50 value of 57.25 when compared to the acarbose (STD) of 94% with IC50 values of 42.78. The maximum percentage of DPP-4 inhibition of T. foenum graecum extract at 320 μg/ml is 77.84% (p<0.01) with IC50 value of 52.26 when compared to the vildagliptin (STD) it is 80.15% with IC50 value of 22.98.Conclusion: The results of the in vitro studies show that T. foenum graecum seed extract has significant alpha-glucosidase and DPP-4 inhibition. Further in vivo and clinical studies are necessary to establish the antihyperglycemic and antidiabetic potential of T. foenum graecum seed extract for the treatment of Type 2 diabetes mellitus

Induction of insulin secretion in engineered liver cells by nitric oxide

BACKGROUND: Type 1 Diabetes Mellitus results from an autoimmune destruction of the pancreatic beta cells, which produce insulin. The lack of insulin leads to chronic hyperglycemia and secondary complications, such as cardiovascular disease. The currently approved clinical treatments for diabetes mellitus often fail to achieve sustained and optimal glycemic control. Therefore, there is a great interest in the development of surrogate beta cells as a treatment for type 1 diabetes. Normally, pancreatic beta cells produce and secrete insulin only in response to increased blood glucose levels. However in many cases, insulin secretion from non-beta cells engineered to produce insulin occurs in a glucose-independent manner. In the present study we engineered liver cells to produce and secrete insulin and insulin secretion can be stimulated via the nitric oxide pathway. RESULTS: Expression of either human insulin or the beta cell specific transcription factors PDX-1, NeuroD1 and MafA in the Hepa1-6 cell line or primary liver cells via adenoviral gene transfer, results in production and secretion of insulin. Although, the secretion of insulin is not significantly increased in response to high glucose, treatment of these engineered liver cells with L-arginine stimulates insulin secretion up to three-fold. This L-arginine-mediated insulin release is dependent on the production of nitric oxide. CONCLUSION: Liver cells can be engineered to produce insulin and insulin secretion can be induced by treatment with L-arginine via the production of nitric oxide

A Rare Cause of Acute Abdomen in Adults: Adult Intussusception

Adult intussusception is rare, less common and differs from childhood intussusception in its presentation, aetiology and treatment. It is common in paediatrics of less than three years of age.1,2 Unlike in paediatric population, most adult cases presented to emergency department with intestinal obstruction, and rarely, the actual diagnosis of intussusception is made during clinical setting. Top causes of adult intussusception include malignant or benign lesions, post-operative complications such as adhesions, Meckel diverticulum and bowel inflammatory disease.  8-20% of cases are idiopathic with no lead point lesion.3 Preliminary radiograph may show signs of intestinal obstruction, but computed tomography (CT) is the gold standard imaging for intussusception. This is a case report of an adult intussusception in Hospital Tengku Ampuan Afzan, Kuantan which was not detected during clinical examination, but diagnosed by CT imaging.

Feed the Future IPM Innovation Lab: A Critical Role in Global Food Security

The World Food Summit of 1966 defined ”food security” as existing “when all people at all times have access to sufficient, safe, and nutritious food to maintain a healthy and active life.” Food insecurity is part of a continuum that includes hunger (food deprivation), malnutrition (deficiencies, imbalances, or excess of nutrients), and famine. The world faces three major challenges: (1) to match the rapidly changing demand for food, (2) to do so in ways that are environmentally and socially acceptable, and (3) to ensure that the world’s poorest people are no longer hungry. World population is expected to reach 9 billion in 2050. To feed this population, there must be a 60–70% increase in food production. The effects of climate change must also be dealt with. The area under cultivation is not expected to expand to meet the gap, and we have yet to meet it by increasing yield per unit area and reducing losses in field and post-harvest handling. A concerted effort to reduce losses without jeopardizing environmental and public health concerns by adopting Integrated Pest Management (IPM) could reduce the loss by 50%, leading to a needed increase in food production of only 30%. Over several decades, the IPM Collaborative Research Program (CRSP) consortium developed IPM packages for tomatoes, other tropical vegetables, fruit, and grain crops and disseminated in host countries through research and extension arms. In addition, several national, regional, and international workshops have been conducted. The IPM Innovation Lab (new name for CRSP in 2013) is playing a vital role in the struggle for global food security. This will continue through the new Feed the Future IPM Innovation Lab which has expanded beyond a limited number of vegetables to include more vegetables, rice, fruit, maize, chickpea, climate change, and invasive species