Malfeasance of KRAS mutations in carcinogenesis

Clinical and Experimental Medicine - Activating mutations in the KRAS gene (Kirsten rat sarcoma 2 viral oncogene homolog gene) are commonly seen across the various solid organ and hematolymphoid...     

The place of Riedel's procedure in contemporary sinus surgery

Many operative procedures have been described to treat frontal sinus disease with varying results. Obliteration of the frontal sinus is attempted when drainage procedures fail. Most large series of patients undergoing sinus obliteration have reported recurrent disease yet the management of these patients is rarely discussed. We believe Riedel's procedure has an important role in the management of these patients. Riedel's procedure can help eradicate frontal sinus disease and symptoms when drainage and obliteration have failed and where there is persistent disease involving the anterior wall of the frontal sinus or the sinus itself. Whilst cranialization has a role in the removal of the mucosa or contents of the frontal sinus in craniofacial resection, the morbidity associated with it make Riedel's procedure preferable for dealing with chronic infection or locally invasive disease. Riedel's procedure also maintains a barrier in the form of the posterior wall of the frontal sinus and the intracranial contents. Post-operative disfigurement, the main criticism of this procedure, can be reduced to some extent by chamfering the margins of the frontal sinus along with the supraorbital rims and reconstructing the anterior wall at a later date if necessary. The authors are aware that any report about frontal sinus surgery should be judged after several years follow-up, and whilst not all these cases have been asymptomatic for a decade, several have been reviewed for many years.     

Synthesis and structure-activity relationships of 6-substituted 2',3'-dideoxypurine nucleosides as potential anti-human immunodeficiency virus agents

In order to study the structure-activity relationships of 2',3'-dideoxypurine nucleosides as potential anti-HIV agents, various 6-substituted purine analogues have been synthesized and examined in virus-infected and uninfected human peripheral blood mononuclear cells. N6-methyl-2',3'-dideoxyadenosine (D2MeA, 7a) was initially synthesized from adenosine via 2',3'-O-bisxanthate 3. As extension of this reaction to other N6-substituted compounds failed, a total synthetic method utilizing 2',3'-dideoxyribose derivative 9 was used for the synthesis of other purine nucleosides. An acid-stable derivative of N6-methyl-2',3'-dideoxyadenosine, 2'-fluoroarabinofuranosyl analogue 32 (D2MeFA), has been synthesized from the appropriate carbohydrate 24 by condensation with N6-methyladenine 23. Among these compounds, N6-methyl derivative (D2MeA) 7a proved to be one of the most potent antiviral agents. The order of potency for the 6-substituted compounds was NHMe greater than NH2 greater than Cl approximately N(Me)2 greater than SMe greater than OH approximately NHEt greater than SH greater than NHBn approximately H. The results suggest that a bulk tolerance effect at the 6-position of the 2',3'-dideoxypurine nucleoside may dictate the antiviral activity of these compounds. Acid-stable analogue 32 (D2MeFA) was found to be 20-fold less potent than the parent compound. Both D2MeA and D2MeFA were resistant to calf intestine adenosine deaminase. The presence of a fluorine atom in the carbohydrate moiety greatly increased stability to acid, making D2MeFA a potential orally active antiviral agent that could be useful for the treatment of retroviral infections in humans.     

Tigers and their prey: Predicting carnivore densities from prey abundance

The goal of ecology is to understand interactions that determine the distribution and abundance of organisms. In principle, ecologists should be able to identify a small number of limiting resources for a species of interest, estimate densities of these resources at different locations across the landscape, and then use these estimates to predict the density of the focal species at these locations. In practice, however, development of functional relationships between abundances of species and their resources has proven extremely difficult, and examples of such predictive ability are very rare. Ecological studies of prey requirements of tigers Panthera tigris led us to develop a simple mechanistic model for predicting tiger density as a function of prey density. We tested our model using data from a landscape-scale long-term (1995-2003) field study that estimated tiger and prey densities in 11 ecologically diverse sites across India. We used field techniques and analytical methods that specifically addressed sampling and detectability, two issues that frequently present problems in macroecological studies of animal populations. Estimated densities of ungulate prey ranged between 5.3 and 63.8 animals per km2. Estimated tiger densities (3.2-16.8 tigers per 100 km2) were reasonably consistent with model predictions. The results provide evidence of a functional relationship between abundances of large carnivores and their prey under a wide range of ecological conditions. In addition to generating important insights into carnivore ecology and conservation, the study provides a potentially useful model for the rigorous conduct of macroecological science.     

Synthesis and antitumor studies on novel Co(II), Ni(II) and Cu(II) metal complexes of bis(3-acetylcoumarin)thiocarbohydrazone

The synthesis, structure, physico-chemical investigation and biological studies of some metal complexes of thiocarbohydrazone ligands are described. The ligand is obtained by condensation of N,N'-thiocarbohydrazide with 3-acetylcoumarin. The metal complexes of Co(II), Ni(II) and Cu(II) with bis(3-acetylcoumarin)thiocarbohydrazone were synthesized and isolated as solid products and characterized by analytical means as well as by spectral techniques such as FT-IR, (1)H NMR and EPR and UV spectrometry. The ligand acts as bidentate, through NO or NN, neutral in coordinating the M(II) ions. The bonding sites are the azomethine nitrogen, lactone carbonyl oxygen and respective anion counterparts. The metal complexes exhibit either octahedral or distorted octahedral structures. The complexes are found to be soluble in dimethylformamide and dimethylsulphoxide. Molar conductance values in dimethylsulphoxide indicate the non-electrolytic nature of the complexes. The compounds tested in present study have shown promising cytotoxic activity when screened using the in vitro method and at the same time were shown to have good activity when tested using the Ehrlich Ascites Carcinoma model. Preliminary antimicrobial screening shows the promising results against both bacterial and fungal strains.     

Immunogenicity and safety study of Indirab: A Vero cell based chromatographically purified human rabies vaccine

A chromatographically purified Vero cell rabies vaccine, Indirab manufactured by Bharat Biotech International Limited, Hyderabad, India was subjected to safety and immunogenicity studies by both intramuscular and intradermal routes of administration in parallel with a reference vaccine, Verorab. A Pre-exposure study was undertaken in 239 subjects by intramuscular (IM) route (Study I), Post-exposure study in 188 patients by intramuscular route (Study II) and Simulated post-exposure study in 134 subjects by intradermal (ID) route (Study III). All subjects in these studies were administered with either the test or the reference vaccine as per WHO approved intramuscular and intradermal regimens. The blood samples were collected on days 0, 14 and 35 in case of Study 1, and days 0, 14, 28 and 90 in case of studies II and III. In all studies both vaccine groups had adequate antibody titers (>0.5 IU/mL) on all days tested post-vaccination and there was no significant difference in the titers observed (p > 0.05). Some side effects like pain, induration, itching and fever were noted in both vaccine groups in all studies. Both vaccines were well tolerated. Hence it can be concluded that Indirab is as safe and immunogenic as Verorab when administered by both intramuscular and intradermal routes.     

Scientific evidence for traditional claim of anti-obesity activity of Tecomella undulata bark

Ethnopharmacological relevance

The bark of Tecomella undulata is traditionally claimed in the treatment of various disease ailments including obesity and cancer. Till now there are no studies about anti-obesity activity of Tecomella undulata bark.

Aim of the study

The present study was aimed to establish a scientific evidence for anti-obesity efficiency of ethyl acetate extract of Tecomella undulata bark (EATUB). Further to standardize the active fractions of EATUB using different biomarkers.

Materials and methods

We investigated activity of EATUB fractions (F1–F7) using 3T3-L1 fibroblasts. Further, F1-mediated effects were characterized by determining mRNA and protein levels of SIRT1, one of the key targets for the treatment of obesity, using semi-quantitative RT-PCR (sqRT-PCR) and western blot analysis. The consequences of modulation of SIRT1 on mRNA and protein levels of various adipogenesis mediators like PPARγ, C/EBPα, E2F1, leptin, adiponectin and LPL were also studied. In vivo studies were performed using High Fat Diet (HFD) obese mice.

Results

Our data showed that compared to controls, preadipocytes and adipocytes incubated with F1 exhibited a significant decrease in adipogenesis and lipogenesis. In addition, sqRT-PCR and western blot analysis showed significant increase in SIRT1 and adiponectin levels and decrease in PPARγ, C/EBPα, E2F1, leptin and LPL levels in preadipocytes and adipocytes. In vivo studies of F1 in HFD induced obese mice showed significant improvement in lipid profile and glucose levels. The bioactive fraction (F1) was determined to possess 4.95% of ferulic acid.

Conclusion

Thus, our findings signified the beneficial effects of Tecomella undulata bark in pharmacologic interventions related to obesity and metabolic disorders. Ferulic acid and rutin are being reported and quantified for the first time from the bark of Tecomella undulata.