Stable isotope labeling as a promising tool for rapid drug susceptibility testing in Neisseria gonorrhoeae.

The world is heading towards an era of intractable and impending untreatable N. gonorrhoeae, thereby underlining the significance of rapid and accurate prediction of drug resistance as an indispensable need of the hour. In the present study, we optimized and evaluated a stable isotope labeling-based approach using the MALDI-TOF MS (Matrix-Assisted Laser Desorption/Ionization-Time of Flight Mass Spectrometry) for rapid and reliable detection of ciprofloxacin and azithromycin resistance in N. gonorrhoeae. All the isolates were cultured under three varied condition setups viz. medium supplemented with normal lysine, heavy lysine (isotope), and heavy lysine along with the antibiotics (ciprofloxacin/azithromycin), respectively. After incubation, spectra were acquired using the MALDI-TOF MS which were further screened for unique patterns (media-specific spectra) to differentiate drug-susceptible and resistant isolates. The results of the stable isotope labeling assay were comparable to the results of phenotypic methods used for susceptibility testing.

Biosynthesis and characterization of gold nanoparticles: Kinetics, in vitro and in vivo study.

This study reports a facile, cost effective, nontoxic and eco-friendly method for the synthesis of gold nanoparticles. In this paper, leaf extract of Mentha piperita was successfully used to reduce chloroauric acid, leading to synthesis of gold nanoparticles (AuNPs). The synthesized nanoparticles were further characterized by UV-visible spectroscopy, Fourier transform infrared spectroscopy, dynamic light scattering, transmission electron microscopy and field emission scanning electron microscopy. Kinetics studies like effect of volume of leaf extract, precursor, pH, temperature for the synthesis of AuNPs were studied spectrophotometrically. Synthesized AuNPs were found to possess hexagon structure where size of nanoparticles was ~78nm in diameter. These biologically synthesized AuNPs exhibited significant activity against cancerous cell lines MDA-MB-231 and A549 and was compared with the normal 3T3-L1 cell line. Anti-inflammatory and analgesic activities were studied on a Wistar rat model to gauge the impact of AuNPs for a probable role in these applications. AuNPs gave positive results for both these activities, although the potency was less as compared to the standard drugs. These results suggested that the leaves extract of Mentha piperita is a very good bioreductant for the synthesis of AuNPs and have potential for various biomedical and pharmaceutical applications.

Attenuation of the cyproterone acetate-induced testicular hypofunction by a novel nutraceutical lycopene: a genomic approach.

This study was designed to explore the cyproterone acetate (CPA)-induced andrological hypofunction and its correction by oral administration of lycopene. In this concern, spermatogenic, biochemical, histological and genomic profiles were studied. Cyproterone acetate administration for 1 month helped to develop infertile model rats. A significant recovery was noted in sperm motility, sperm count, sperm viability, hypo-osmotic swelling tail-coiled spermatozoa; activities of testicular ∆5 , 3ß-hydroxysteroid dehydrogenase (HSD), 17ß-HSD, catalase (CAT) and superoxide dismutase (SOD); and levels of conjugated diene (CD), malondialdehyde (MDA), testicular cholesterol and serum testosterone after the administration of lycopene at 1.5 mg/0.5 ml Tween-80/100 g body weight/day for last 1 month to infertile model rats. Simultaneously, qRT-PCR study of Bax, Bcl-2, caspase-3, ∆5 , 3ß-HSD and 17ß-HSD genes in testicular tissue showed a significant rectification towards the control in CPA-pre-treated cum CPA-lycopene-cotreated rats. Side-by-side histological and histometric studies showed a significant correction in qualitative analysis of spermatogenesis and seminiferous tubular diameter (STD) in CPA-pre-treated cum CPA-lycopene-cotreated rats. Lycopene showed outstanding efficacy in the management of CPA-induced testicular hypofunction with special reference to correction in oxidative stress-induced testicular apoptosis at genomic level.

Antiapoptotic efficacy of seed of Eugenia jambolana on testicular germ cell in experimental diabetic rat: a genomic study.

This study was designed to focus the genetic regulation of diabetes-induced testicular hypofunction and its amelioration by ethyl acetate fraction of seed of Eugenia jambolana. In this regard, we have assessed relevant biosensors such as biochemical, spermiological, histological and gene expression of antioxidant enzymes, germ cell apoptosis and androgenic key enzymes along with in situ end labelling and DNA fragmentation study. After 60 days administration of said fraction, significant recovery in the glycated haemoglobin, serum testosterone, sperm viability, hypo-osmotic swelling and nuclear chromatin decondensation were noted in fraction-treated diabetic group in comparison with diabetic control. Besides this, a significant recovery in the expression of Bax, Bcl-2, caspase-9, caspase-3, catalase, peroxidase, ∆(5) , 3ß-hydroxy steroid dehydrogenase and 17ß-hydroxy steroid dehydrogenase genes was noted towards the control in ethyl acetate fraction-treated group. Testicular histology focused a significant recovery in the number of different generation of germ cells at stage VII of spermatogenesis in fraction-treated group. In situ end labelling and DNA fragmentation study of testicular tissues also showed a significant recovery in fraction-treated group towards the control. These findings indicate that the ethyl acetate fraction showed outstanding antiapoptotic activity by neutralising oxidative stress as well as by the improvement in glycaemic sensors.

Dengue vaccines: challenges, development, current status and prospects.

Infection with dengue virus (DENV) is the most rapidly spreading mosquito-borne viral disease in the world. The clinical spectrum of dengue, caused by any of the four serotypes of DENV, ranges from mild self-limiting dengue fever to severe dengue, in the form dengue hemorrhagic fever (DHF) and dengue shock syndrome (DSS). Increased rates of hospitalization due to severe dengue, during outbreaks, result in massive economic losses and strained health services. In the absence of specific antiviral therapy, control of transmission of DENV by vector management is the sole method available for decreasing dengue-associated morbidity. Since vector control strategies alone have not been able to satisfactorily achieve reduction in viral transmission, the implementation of a safe, efficacious and cost-effective dengue vaccine as a supplementary measure is a high public health priority. However, the unique and complex immunopathology of dengue has complicated vaccine development. Dengue vaccines have also been challenged by critical issues like lack of animal models for the disease and absence of suitable markers of protective immunity. Although no licensed dengue vaccine is yet available, several vaccine candidates are under phases of development, including live attenuated virus vaccines, live chimeric virus vaccines, inactivated virus vaccines, subunit vaccines, DNA vaccines and viral-vectored vaccines. Although some vaccine candidates have progressed from animal trials to phase II and III in humans, a number of issues regarding implementation of dengue vaccine in countries like India still need to be addressed. Despite the current limitations, collaborative effects of regulatory bodies like World Health Organization with vaccine manufacturers and policy makers, to facilitate vaccine development and standardize field trials can make a safe and efficacious dengue vaccine a reality in near future.

Spontaneous breaking of time-reversal symmetry in strongly interacting two-dimensional electron layers in silicon and germanium.

We report experimental evidence of a remarkable spontaneous time-reversal symmetry breaking in two-dimensional electron systems formed by atomically confined doping of phosphorus (P) atoms inside bulk crystalline silicon (Si) and germanium (Ge). Weak localization corrections to the conductivity and the universal conductance fluctuations were both found to decrease rapidly with decreasing doping in the Si:P and Ge:P delta layers, suggesting an effect driven by Coulomb interactions. In-plane magnetotransport measurements indicate the presence of intrinsic local spin fluctuations at low doping, providing a microscopic mechanism for spontaneous lifting of the time-reversal symmetry. Our experiments suggest the emergence of a new many-body quantum state when two-dimensional electrons are confined to narrow half-filled impurity bands.

Corrective role of Eugenia jambolana on testicular impairment in streptozotocin-induced diabetic male albino rat: an approach through genomic and proteomic study.

The present study was conducted to explore the effect of ethyl acetate fraction of hydro-methanolic (40 : 60) extract of seed of Eugenia jambolana on testicular impairment in diabetic rats. In this respect, biomarkers of oxidative stress, genomics and proteomics in testicular tissue were assessed. Side by side, glycated haemoglobin, serum testosterone, activities of glutamate oxaloacetate transaminase and glutamate pyruvate transaminase in serum, epididymal sperm count including reproductive organosomatic indices were evaluated. Results indicate that a significant recovery (P < 0.05) in the levels of these parameters in fraction-treated diabetic group in comparison with diabetic control. A significant recovery was noted (P < 0.05) in the expression of Bax and Bcl-2 gene towards the control after the treatment of said fraction. Histological study also focused a significant recovery (P < 0.05) in the number of different generation of germ cells at stage VII of spermatogenesis in fraction-treated diabetic group. The said fraction treatment to diabetic rat can recover the activities of serum glutamate oxaloacetate transaminase and glutamate pyruvate transaminase significantly towards the control (P < 0.05). Finally, it may be concluded that ethyl acetate fraction of seed of E. jambolana has a promiseable remedial effect on diabetes-induced testicular dysfunctions in male rat without inducing any metabolic toxicity.

A review on therapeutic potential of Lygodium flexuosum Linn.

From the centuries, herbal medicines are used to treat various diseases and now they had become an item of global importance, with both medicinal and economic implications. The demand of herbal medicine is being increasing day by day due to their safety and efficacy. Now herbals had taken over the allopathic system due to their less side effect and efficient working mechanism. Herbals are playing and pivotal role in increasing the economy of the country and had taken the nation on to the new path to achieve the goal of development. Lygodium flexuosum (Linn) Sw. is a fern found nearly throughout India up to an elevation of 1500 meter. It belongs to the family Lygodiaceae and widely used in treating various ailments like jaundice, dysmenorrhea, wound healing and eczema. It is the rich source of alkaloids, flavonoids, saponins and cumarin. The main constitute of the plant is lygodinolide which is mainly used in wound healing. In the present review an attempt had been made to explore different aspects of L. flexuosum.

Darbepoetin alfa for treatment of anaemia in a case of chronic renal failure during pregnancy--case report.

Oral haematinics are frequently, if not ubiquitously, used to supplement dietary iron in pregnancy. A 21-year-old patient attended the antennal clinic because she suffered from nephritic syndrome due to focal segmental glomerulosclerosis. Despite treatment with oral haematinics, her haemoglobin level continued to fall. After a blood transfusion, her renal function deteriorated. She was started on darbepoetin alfa, a long-acting erythropoietin, for treat the anaemia caused by renal failure.

Comparative study of oestrogenic properties of eight phytoestrogens in MCF7 human breast cancer cells.

Previous studies have compared the oestrogenic properties of phytoestrogens in a wide variety of disparate assays. Since not all phytoestrogens have been tested in each assay, this makes inter-study comparisons and ranking oestrogenic potency difficult. In this report, we have compared the oestrogen agonist and antagonist activity of eight phytoestrogens (genistein, daidzein, equol, miroestrol, deoxymiroestrol, 8-prenylnaringenin, coumestrol and resveratrol) in a range of assays all based within the same receptor and cellular context of the MCF7 human breast cancer cell line. The relative binding of each phytoestrogen to oestrogen receptor (ER) of MCF7 cytosol was calculated from the molar excess needed for 50% inhibition of 3H]oestradiol binding (IC50), and was in the order coumestrol (35x)/8-prenylnaringenin (45x)/deoxymiroestrol (50x)>miroestrol (260x)>genistein (1000x)>equol (4000x)>daidzein (not achieved: 40% inhibition at 10(4)-fold molar excess)>resveratrol (not achieved: 10% inhibition at 10(5)-fold molar excess). For cell-based assays, the rank order of potency (estimated in terms of the concentration needed to achieve a response equivalent to 50% of that found with 17beta-oestradiol (IC50)) remained very similar for all the assays whether measuring ligand ability to induce a stably transfected oestrogen-responsive ERE-CAT reporter gene, cell growth in terms of proliferation rate after 7 days or cell growth in terms of saturation density after 14 days. The IC50 values for these three assays in order were for 17beta-oestradiol (1 x 10(-11)M, 1 x 10(-11)M, 2 x 10(-11)M), and in rank order of potency for the phytoestrogens, deoxymiroestrol (1 x 10(-10)M, 3 x 10(-11)M, 2 x 10(-11)M)>miroestrol (3 x 10(-10)M, 2 x 10(-10)M, 8 x 10(-11)M)>8-prenylnaringenin (1 x 10(-9)M, 3 x 10(-10)M, 3 x 10(-10)M)>coumestrol (3 x 10(-8)M, 2 x 10(-8)M, 3 x 10(-8)M)>genistein (4 x 10(-8)M, 2 x 10(-8)M, 1 x 10(-8)M)/equol (1 x 10(-7)M, 3 x 10(-8)M, 2 x 10(-8)M)>daidzein (3 x 10(-7)M, 2 x 10(-7)M, 4 x 10(-8)M)>resveratrol (4 x 10(-6)M, not achieved, not achieved). Despite using the same receptor context of the MCF7 cells, this rank order differed from that determined from receptor binding. The most marked difference was for coumestrol and 8-prenylnaringenin which both displayed a relatively potent ability to displace [3H]oestradiol from cytosolic ER compared with their much lower activity in the cell-based assays. Albeit at varying concentrations, seven of the eight phytoestrogens (all except resveratrol) gave similar maximal responses to that given by 17beta-oestradiol in cell-based assays which makes them full oestrogen agonists. We found no evidence for any oestrogen antagonist action of any of these phytoestrogens at concentrations of up to 10(-6)M on either reporter gene induction or on stimulation of cell growth.

A comparative analysis of immunorestoration and recovery with conventional and immunotherapeutic protocols in canine generalized demodicosis: a newer insight of immunotherapeutic efficacy of T11TS.

Demodex canis is a natural inhabiting mite of canine skin. Immunological disorder or genetic disorder induces the Demodex population to proliferate vigorously resulting in generalized demodicosis with consequent chronic immunosuppression. Signs of generalized demodicosis include alopecia, crysting, erythema, secondary pyoderma etc. Amitraz, an acaricide, is used conventionally for the treatment of generalized demodicosis. In many instances, the disease relapses due to the residual immunosuppression. The need of an immunorestorative therapy has been urged in generalized demodicosis. Two immunorestorative drugs, namely, Immuplus, a herbal drug, and T11TS, a sheep erythrocyte surface glycoprotein, has been used in two separate groups of dogs having generalized demodicosis and receiving Amitraz treatment. It was observed that though Amitraz treated group responded to the therapy showing increased E-rosettes and nonspecific cytotoxic efficacy of T-lymphocytes and decrease in phagocytic potential of macrophages, the groups treated with the immunotherapeutics like Immuplus and T11TS, responded better. However, the group treated with T11TS showed best recovery. These results emphasize the need for an immunorestorative therapy in generalized demodicosis and provide data in favor of T11TS as a better immunomodulator in comparison to Immuplus.

Antitussive activity of Abies webbiana Lindl. leaf extract against sulphur dioxide-induced cough reflex in mice.

The methanol extract of A. webbiana Lindl was evaluated for its effect on a cough model induced by sulphur dioxide gas in mice. When administered orally it exhibited significant antitussive activity compared with the control in a dose dependent manner. The antitussive activity of the extract was compared with that of codeine phosphate, a prototype antitussive agent. The A. webbiana leaf extract (400 and 600 mg/kg) showed maximum inhibition of cough frequency by 71.69% and 78.67%, respectively, when compared with the control group and was comparable in effect to codeine phosphate.

Change in distribution & antifungal susceptibility of Candida species isolated from candidaemia cases in a tertiary care centre during 1996-2000.

BACKGROUND & OBJECTIVES: As a marked increase in the number of patients with candidaemia was reported in the first half (1991-1995) of the last decade at the Postgraduate Institute of Medical Education & Research, Chandigarh, India, the present study was aimed at determining further change if any, in the incidence and distribution of Candida species and their antifungal resistance pattern during the second half (1996-2000) of the same decade. METHODS: The patients with candidaemia were studied to determine the frequency of candidaemia and Candida species isolated during 1996-2000. One hundred Candida strains other than Pichia anomala (C. pelliculosa) were randomly selected from those isolates to evaluate antifungal susceptibility pattern against amphotericin B, 5-fluorocytosine, ketoconazole, fluconazole and itraconazole. The results were compared with our previous study. RESULTS: An increase in the number of patients with candidaemia was observed during 1996 (538) and 1997 (421) compared to 1998-2000 due to P. anomala outbreak. With the control of the outbreak, a substantial decrease in the incidence of candidaemia was observed from 1998 (251 in 1998, 122 in 1999 and 165 in 2000). A higher isolation of non-C. albicans Candida species (89.8%) was observed, with C. tropicalis being the most common (541, 36.1%) agent. No major change in the isolation rate of other non-C. albicans Candida species (C. guilliermondii, C. krusei, C. glabrata and C. parapsilosis) was observed. An emergence of resistance to amphotericin B in 15.4 per cent C. albicans, 8.1 per cent C. tropicalis and 33.3 per cent C. krusei strains was observed. An increase in resistance to ketoconazole (from 0% to 13%) and 5-fluorocytosine (from 1% to 8%) and a decrease to fluconazole (from 13% to 6%) were observed. Resistance to itraconazole was observed in 17 per cent of Candida strains by broth macro-dilution method. INTERPRETATION & CONCLUSION: A change in the isolation of Candida species was observed i.e. in the incidence and isolation of non-C. albicans Candida species. Emergence of resistance to amphotericin B and increase of resistance to most other antifungals are cause for concern.

Growth behaviour and bioproduction of indole acetic acid by a Rhizobium sp. isolated from root nodules of a leguminous tree Dalbergia lanceolaria.

The Rhizobium sp. isolated from healthy and mature root nodules of a leguminous tree, Dalbergia lanceolaria Linn. f., preferred mannitol and KNO3 for growth as carbon and nitrogen sources, respectively. The bacterium produced a high amount (22.3 microg/ml) of indole acetic acid (IAA) from L-tryptophan supplemented basal medium. Growth and IAA production started simultaneously. IAA production was maximum at 20 hr when the bacteria reached the stationary phase of growth. Cultural requirements were optimized for maximum growth and IAA production. The IAA production by the Rhizobium sp. was increased by 270.8% over control when the medium was supplemented with mannitol (1%,w/v), SDS (1 microg/ml), L-asparagine (0.02%,w/v) and biotin (1 microg/ml) in addition to L-tryptophan (2.5 mg/ml). The possible role of IAA production in the symbiosis is discussed.

Advances in cancer therapy with plant based natural products.

Natural Products have long been a fertile source of cure for cancer, which is projected to become the major causes of death in this century. However, there is a continuing need for development of new anticancer drugs, drug combinations and chemotherapy strategies, by methodical and scientific exploration of enormous pool of synthetic, biological and natural products. There are at least 250,000 species of plants out of which more than one thousand plants have been found to possess significant anticancer properties. While many molecules obtained from nature have shown wonders, there are a huge number of molecules that still either remains to be trapped or studied in details by the medicinal chemists. The article reviews many such structures and their related chemistry along with the recent advances in understanding mechanism of action and structure-function relationships of nature derived anti-cancer agents at the molecular, cellular and physiological levels. Taxol, one of the most outstanding agents, has been found beneficial in treatment of refractory ovarian, breast and other cancers. Another prominent molecule includes Podophyllotoxin. Synthetic modification of this molecule led to the development of Etoposide, known to be effective for small cell cancers of the lungs and testes. Camptothecin isolated from Camptotheca acuminata also have been extensively studied. Other important molecules discussed include Vincristine, Vinblastine, Colchicine, Ellipticine and Lepachol along with Flavopiridol, a semi-synthetic analogue of the chromone alkaloid Rohitukine from India, a pyridoindole alkaloid from leaves of Ochrosia species and many more. The review also deals with the lesser-known plants of sub-Himalayan region.

Immunization with A2 protein results in a mixed Th1/Th2 and a humoral response which protects mice against Leishmania donovani infections.

The A2 genes of Leishmania donovani encode amastigote-specific A2 proteins, which are considered to be virulence factors required for the survival of this protozoan parasite in the mammalian host. The A2 genes are present within a multigene family and corresponding A2 proteins are composed predominantly of multiple copies of a 10 amino acid repeat sequences. A2-specific antibodies have been detected in the sera of patients suffering from visceral leishmaniasis (VL) and it has been shown that generation of A2 deficient L. donovani resulted in an avirulent phenotype. In this report, we show that immunization of mice with recombinant A2 protein conferred significant protection against challenge infection with L. donovani. The protection correlated with in vitro splenocyte proliferation, production of IFN-gamma in response to A2 protein and the presence of A2-specific antibodies in the sera of immunized mice. These data demonstrate that A2 represents a potential antigen for protection against infection with L. donovani and VL.

Extracellular polysaccharide production by Azorhizobium caulinodans from stem nodules of leguminous emergent hydrophyte Aeschynomene aspera.

The Azorhizobium caulinodans isolated from the stem nodules of a leguminous emergent hydrophyte, Aeschynomene aspera, produced a large amount of extracellular polysaccharides (EPS) in yeast extract basal medium. Maximum EPS production was at the stationary phase of growth. EPS production was increased by 919% over control when the medium was supplemented with sucrose (1.5%), D-biotin (1 microgram/ml) and casamino acid (0.1%). EPS contained rhamnose and arabinose. Possible role of the azorhizobial EPS production in the stem nodule symbiosis is discussed.

Neurotrophins: new roles for a seasoned cast.

Recent studies suggest that endogenous neurotrophins play a central role in the patterning of cortical connections and in cortical synaptic physiology. Do these effects of neurotrophids reflect independent cellular events, or are they manifestations of a single cellular mechanism central to developmental plasticity?

Species selectivity of new siderophore-drug conjugates that use specific iron uptake for entry into bacteria.

Siderophores selectively bind ferric iron and are involved in receptor-specific iron transport into bacteria. Several types of siderophores were synthesized, and growth-promoting or inhibitory activities when they were conjugated to carbacephalosporin, erythromycylamine, or nalidixic acid were investigated. Overall, 11 types of siderophores and 21 drug conjugates were tested against seven different bacterial species: Escherichia coli, Bordetella bronchiseptica, Pasteurella multocida, Pasteurella haemolytica, Streptococcus suis, Staphylococcus aureus, and Staphylococcus epidermidis. In some species, the inhibitory activities of the drug conjugates were associated with the ability of the bacteria to use the siderophore portion of the molecules for growth promotion in disc diffusion tests (0.04 mumol of conjugate or siderophore per disc). E. coli used catechol-based siderophore portions as well as hydroxamate-based tri-delta-OH-N-OH-delta-N-acetyl-L-ornithine ferric iron ligands for growth under iron-restricted conditions achieved by supplemental ethylenediamine di (O-hydroxyphenylacetic acid) (100 micrograms/ml) and was sensitive to carbacephalosporin conjugated to these siderophore types (up to a 34-mm-diameter inhibition zone). B. bronchiseptica used desferrioxamine B and an isocyanurate-based or trihydroxamate in addition to catechol-based siderophore portions for promotion but was not inhibited by beta-lactam conjugates partly because of the presence of beta-lactamase. P. multocida and P. haemolytica did not use any of the synthetic siderophores for growth promotion, and the inhibitory activities of some conjugates seemed partly linked to their ability to withhold iron from these bacteria, since individual siderophore portions showed some antibacterial effects. Individual siderophores did not promote S. suis growth in restrictive conditions, but the type of ferric iron ligands attached to beta-lactams affected inhibitory activities. The antibacterial activities of the intracellular-acting agents erythromycylamine and nalidixic acid were reduced or lost, even against S. aureus and S. epidermidis, when the agents were conjugated to siderophores. Conjugate-resistant E. coli mutants showed the absence of some iron-regulated outer membrane proteins in gel electrophoresis profiles and in specific phage or colicin sensitivity tests, implying that the drugs used outer membrane receptors of ferric complexes to get into cells.

Cortical development: with an eye on neurotrophins.

Recent observations suggest that neurotrophins are involved in activity-dependent plasticity of the developing cerebral cortex. What molecular mechanisms underlie activity-dependent competition between axons for trophic factors?