Synthesis, characterization, spectroscopic studies and biological evaluation of Schiff bases derived from 1-hydroxy-2-acetonapthanone.

The four Schiff bases (I - IV) were synthesized by the condensation reaction of 1(1-hydroxynaphthalen-2-yl)ethanone, 1-(4-chloro-1hydroxynaphthalen-2-yl)ethanone and 1-(4-bromo-1-hydroxynaphthalen-2-yl)ethanone with propane-1,3-diamine and pentane-1,3-diamine. The structural analysis is done by UVvis., FT-IR, 1H NMR, 13C NMR, LCMS and elemental analyses. These compounds were assayed for antibacterial (Escherichia coli and Salmonella Typhi) activity and antioxidant (2,2-Diphenyl-1-Picryl Hydrazyl(DPPH) and Hydroxyl radical scavenging method) activity. The antibacterial and antioxidant activities of synthesized Schiff bases exhibited better degrees of inhibitory effects. Among these, Schiff base 2,2'-((propane-1,3-diylbis(azanylylidene))bis(ethan-1-yl-1-ylidene))bis(4-chloronaphthalen-1-ol) (II) exhibited excellent antibacterial activity with MICs of 0.12, 0.25, 0.5 and 1 mg/ml against E. coli and Salmonella Typhi. Furthermore, two Schiff bases such as, 2,2'-((propane-1,3-diylbis(azanylylidene))bis(ethan-1-yl-1-ylidene))bis(naphthalen-1-ol) (I) and 2,2'-((pentane-1,3-diylbis(azanylylidene))bis(ethan-1-yl-1-ylidene))bis(4-bromonaphthalen-1-ol) (IV) exhibited promising antioxidant activity.

Brain SPECT scans in students with specific learning disability: Preliminary results.

Background and Objectives: Brain single-photon emission computed tomography (SPECT) assesses brain function through measurement of regional cerebral blood flow. This study was conducted to assess whether students with newly diagnosed specific learning disability (SpLD) show any abnormalities in cerebral cortex perfusion. Settings and Design: Cross-sectional single-arm pilot study in two tertiary care hospitals. Subjects and Methods: Nine students with SpLD were enrolled. Brain SPECT scan was done twice in each student. For the first or "baseline" scan, the student was first made to sit with eyes open in a quiet, dimly lit room for a period of 30-40 min and then injected intravenously with 20 mCi of 99mTc-ECD. An hour later, "baseline scan" was conducted. After a minimum gap of 4 days, a second or "test scan" was conducted, wherein the student performed an age-appropriate curriculum-based test for a period of 30-40 min to activate the areas in central nervous system related to learning before being injected with 20 mCi of 99mTc-ECD. Statistical Analysis Used: Cerebral cortex perfusion at rest and after activation in each student was compared qualitatively by visual analysis and quantitatively using NeuroGam™ software. Results: Visual analysis showed reduction in regional blood flow in temporoparietal areas in both "baseline" and "test" scans. However, when normalization was attempted and comparison done by Talairach analysis using NeuroGam software, no statistically significant change in regional perfusion in temporoparietal areas was appreciated. Conclusion: Brain SPECT scan may serve as a robust tool to identify changes in regional brain perfusion in students with SpLD.

The NUMEN project: Heavy-Ion Double Charge Exchange reactions towards 0νββ NME determination / El proyecto NUMEN: reacciones de intercambio de cargas dobles de iones pesados hacia la determinación de 0νββ NME

Abstract NUMEN proposes cross sections measurements of Heavy-Ion double charge exchange reactions as an innovative tool to access the nuclear matrix elements, entering the expression of the life time of Neutrinoless double beta decay (0νββ). A key aspect of the projectis the use at INFN-Laboratori Nazionali del Sud (LNS) of the Superconducting Cyclotron (CS) for the acceleration of the required high resolution and low emittance heavy-ion beams and of MAGNEX large acceptance magnetic spectrometer for the detection of the ejectiles. The experimental measurements of double charge exchange reactions induced by heavy ions present a number of challenging aspects, since such reactions are characterized by very low cross sections. First experimental results give encouraging indication on the capability to access quantitative information towards the determination of the Nuclear Matrix Elements for 0νββ decay.

Resumen NUMEN propone mediciones de secciones eficaces de reacciones de intercambio de carga doble de iones pesados como una herramienta innovadora para acceder a los elementos de la matriz nuclear, entrando en la expresión del tiempo de vida de la desintegración beta doble sin neutrino (0νββ). Un aspecto clave del proyecto es el uso en INFN-Laboratori Nazionali del Sud (LNS) del ciclotrón superconductor (CS) para la aceleración de los haces de iones pesados de alta resolución y baja emitancia requeridos y del espectrómetro magnético de gran aceptación MAGNEX para la detección de los residuos eyectados. Las mediciones experimentales de reacciones de intercambio de carga doble inducidas por iones pesados presentan una serie de aspectos desafiantes, ya que tales reacciones se caracterizan por secciones eficaces muy bajas. Los primeros resultados experimentales dan una indicación alentadora sobre la capacidad de acceder a información cuantitativa para la determinación de los Elementos de la Matriz Nuclear para la descomposición de 0νββ.

Genetic characterization of Bactrocera fruit flies (Diptera: Tephritidae) from Northeastern India based on DNA barcodes.

The Northeastern region of India, one of the mega biodiversity hot spots has enormous potential for the production of fruits and vegetables. Fruit flies of the genus Bactrocera Macquart are important pests of fruits and vegetables, and one of the limiting factors in successful production of these commodities. The relationship among some of the species is unclear due to their high molecular and morphological similarities. Moreover, due to the significant morphological resemblance between fruit fly species, reliable identification is very difficult task. We genetically characterized 10 fruit fly species of the genus Bactrocera by using standard DNA barcoding region of COI gene. The characterization and identification of eight species were straight forward. This study was unable to establish the molecular identity of Bactrocera sp. 2. Within the 547 bp region of partial COI gene, there were 157 variable sites of which 110 sites were parsimony informative, 153 were synonymous substitutions and 4 were non-synonymous substitutions. The estimate of genetic divergence among the ten species was in the range of 0-21.9% and the pairwise genetic distance of Bactrocera. (Bactrocera) dorsalis (Hendel) with B. (B.) carambolae was only 0.7%. Phylogenetic analysis formed separate clades for fruit and vegetable infesting fruit flies. B. (B.) aethriobasis Hardy, B. (B.) thailandica and B. (B.) tuberculata (Bezzi) have been reported for the first time from the Northeastern India. The information generated from this study would certainly have implications for pest management, taxonomy, quarantine and trade.

Bitter orange (Citrus aurantium L.) extract subchronic 90-day safety study in rats.

Bitter orange (Citrus aurantium L.) extracts are widely used in dietary supplements and bitter oranges are used in various juices and food products. p-Synephrine, the primary active constituent, comprises approximately 90% of total protoalkaloids. This study, performed per OECD 408 guidance, examined the 90-day subchronic safety/toxicity of an extract standardized to 50% p-synephrine at doses of 100, 300 and 1000 mg/kg/day to male and female rats. No adverse effects were observed with respect to any of the observed parameters of clinical signs, functional observations of sensory reactivity, grip strength and motor activity, ophthalmology, body weights, hematology, food consumption, urinalysis, organ weights, as well as gross and microscopic pathology at termination at any of the doses in either sex. Treatment at 1000 mg/kg body weight/day of the extract resulted in non-adverse effects including fully reversible signs of repetitive head burrowing in the bedding material and piloerection for short periods of time in both sexes immediately after administration, which gradually disappeared by treatment day-81. A slight and reversible elevation of BUN and urea levels in male rats, and slight to mild increase in the relative but not absolute heart weights of male and female rats was observed. Based on these results, the no-observed-effect-level (NOEL) for this bitter orange extract standardized to 50% p-synephrine was 300 mg/kg, while the no-observed-adverse-effect-level (NOAEL) was 1000 mg/kg. The results indicate a high degree of safety for this bitter orange extract.

Citrus aurantium (bitter orange) extract: Safety assessment by acute and 14-day oral toxicity studies in rats and the Ames Test for mutagenicity.

The primary active constituent in bitter orange extract (BOE) is p-synephrine. This study assessed the safety of a BOE standardized to 50% p-synephrine following short-term exposure to rats and by the Ames Test. Following 5000 mg/kg of the extract orally to female rats all animals survived. Administration at 2000 mg/kg to female rats for four days yielded no signs of toxicity. Five male and five female rats were administered the BOE at 0, 250, 500, 1000 and 2000 mg/kg/day for 14 days. No significant effects were observed at any dose with respect to body weights, food intake, absolute and relative organ weights, hematology, clinical chemistry, and pathology. Two male rats died after 2000 mg/kg with gastrointestinal impaction at necropsy. During week two of 1000 mg/kg and 2000 mg/kg/day, rats exhibited transient signs of repetitive burrowing of heads in the bedding material (hypoactivity) for about 15 and 45 min, respectively. The no-observed-effect-level (NOEL) was 500 mg/kg/day. The mutagenic potential was assessed at and up to the limit dose of 5000 µg/plate in a Salmonella typhimurium reverse mutation (Ames) test, performed in duplicate as a pre-incubation assay in the presence and absence of metabolic activation (S9). The BOE did not induce an increase in the frequency of revertant colonies at any dose in the five tester strains, and was therefore non-mutagenic.

Initial characterization of the Pf-Int recombinase from the malaria parasite Plasmodium falciparum.

BACKGROUND: Genetic variation is an essential means of evolution and adaptation in many organisms in response to environmental change. Certain DNA alterations can be carried out by site-specific recombinases (SSRs) that fall into two families: the serine and the tyrosine recombinases. SSRs are seldom found in eukaryotes. A gene homologous to a tyrosine site-specific recombinase has been identified in the genome of Plasmodium falciparum. The sequence is highly conserved among five other members of Plasmodia. METHODOLOGY/PRINCIPAL FINDINGS: The predicted open reading frame encodes for a ∼57 kDa protein containing a C-terminal domain including the putative tyrosine recombinase conserved active site residues R-H-R-(H/W)-Y. The N-terminus has the typical alpha-helical bundle and potentially a mixed alpha-beta domain resembling that of λ-Int. Pf-Int mRNA is expressed differentially during the P. falciparum erythrocytic life stages, peaking in the schizont stage. Recombinant Pf-Int and affinity chromatography of DNA from genomic or synthetic origin were used to identify potential DNA targets after sequencing or micro-array hybridization. Interestingly, the sequences captured also included highly variable subtelomeric genes such as var, rif, and stevor sequences. Electrophoretic mobility shift assays with DNA were carried out to verify Pf-Int/DNA binding. Finally, Pf-Int knock-out parasites were created in order to investigate the biological role of Pf-Int. CONCLUSIONS/SIGNIFICANCE: Our data identify for the first time a malaria parasite gene with structural and functional features of recombinases. Pf-Int may bind to and alter DNA, either in a sequence specific or in a non-specific fashion, and may contribute to programmed or random DNA rearrangements. Pf-Int is the first molecular player identified with a potential role in genome plasticity in this pathogen. Finally, Pf-Int knock-out parasite is viable showing no detectable impact on blood stage development, which is compatible with such function.

Identification of DNA binding motifs of the Mycobacterium tuberculosis PhoP/PhoR two-component signal transduction system.

BACKGROUND: The Mycobacterium tuberculosis PhoP/PhoR two-component signal transduction system controls the expression of about 2% of the genome and plays a major role in pathogenicity. However, its regulon has not been well characterized. METHODOLOGY/PRINCIPAL FINDINGS: The binding site of PhoP transcription regulator was identified in the upstream regions of msl3, pks2, lipF and fadD21 genes, by using gene fusions, electrophoretic mobility shift assays and DNase I footprinting experiments. A consensus sequence for PhoP binding was deduced. It consists of two direct repeats, DR1/DR2, associated with a third repeat, DR3, important in some cases for PhoP binding to DR1/DR2 but located at a variable distance from these direct repeats. DR1/DR2 and DR3 consensus sequences were used to screen the whole-genome sequence for other putative binding sites potentially corresponding to genes directly regulated by PhoP. The identified 87 genes, encoding transcription regulators, and proteins involved in secondary metabolites biosynthesis, transport and catabolism are proposed to belong to the PhoP regulon. CONCLUSIONS/SIGNIFICANCE: A consensus sequence derived from the analysis of PhoP binding to four gene promoter regions is proposed. We show for the first time the involvement of a third direct repeat motif in this binding reaction. The consensus sequence was instrumented to study the global regulation mediated by PhoP in M. tuberculosis. This analysis leads to the identification of several genes that are potentially regulated by this key player.

Suitability of PSA-detected localised prostate cancers for focal therapy: experience from the ProtecT study.

BACKGROUND: Contemporary screening for prostate cancer frequently identifies small volume, low-grade lesions. Some clinicians have advocated focal prostatic ablation as an alternative to more aggressive interventions to manage these lesions. To identify which patients might benefit from focal ablative techniques, we analysed the surgical specimens of a large sample of population-detected men undergoing radical prostatectomy as part of a randomised clinical trial. METHODS: Surgical specimens from 525 men who underwent prostatectomy within the ProtecT study were analysed to determine tumour volume, location and grade. These findings were compared with information available in the biopsy specimen to examine whether focal therapy could be provided appropriately. RESULTS: Solitary cancers were found in prostatectomy specimens from 19% (100 out of 525) of men. In addition, 73 out of 425 (17%) men had multiple cancers with a solitary significant tumour focus. Thus, 173 out of 525 (33%) men had tumours potentially suitable for focal therapy. The majority of these were small, well-differentiated lesions that appeared to be pathologically insignificant (38-66%). Criteria used to select patients for focal prostatic ablation underestimated the cancer's significance in 26% (34 out of 130) of men and resulted in overtreatment in more than half. Only 18% (24 out of 130) of men presumed eligible for focal therapy, actually had significant solitary lesions. CONCLUSION: Focal therapy appears inappropriate for the majority of men presenting with prostate-specific antigen-detected localised prostate cancer. Unifocal prostate cancers suitable for focal ablation are difficult to identify pre-operatively using biopsy alone. Most lesions meeting criteria for focal ablation were either more aggressive than expected or posed little threat of progression.

The relaxed requirements of the integron cleavage site allow predictable changes in integron target specificity.

Integrons are able to incorporate exogenous genes embedded in mobile cassettes, by a site-specific recombination mechanism. Gene cassettes are collected at the attI site, via an integrase mediated recombination between the cassette recombination site, attC, and the attI site. Interestingly, only three nucleotides are conserved between attC and attI. Here, we have determined the requirements of these in recombination, using the recombination machinery from the paradigmatic class 1 integron. We found that, strikingly, the only requirement is to have identical first nucleotide in the two partner sites, but not the nature of this nucleotide. Furthermore, we showed that the reaction is close to wild-type efficiency when one of the nucleotides in the second or third position is mutated in either the attC or the attI1 site, while identical mutations can have drastic effects when both sites are mutated, resulting in a dramatic decrease of recombination frequency compared to that of the wild-type sites. Finally, we tested the functional role of the amino acids predicted from structural data to interact with the cleavage site. We found that, if the recombination site triplets are tolerant to mutation, the amino acids interacting with them are extremely constrained.

Safety of an oxygen-coordinated niacin-bound chromium(III) complex (NBC): II. Developmental toxicity study in rats.

The objective of the present study was to evaluate the teratogenic potential of a novel oxygen-coordinated niacin-bound chromium complex (NBC) in Sprague-Dawley rats. Due to its potential to affect fat synthesis and reduce food intake, processes which are often crucial in normal fetal development, this teratology study was undertaken as part of a multi-generation reproductive investigation. The animals in this study were selected randomly after weaning from each F(2b) litter of the F1 generation from the two-generation reproductive toxicity study. To start the teratology study, Sprague-Dawley rat pups ( approximately 30/sex/group) from the F(2b) generation were allowed to grow up to 10-12 weeks of age before mating. The rats in treatment group were exposed directly to NBC through feed. The dietary exposure levels were the same as those employed for the two-generation reproductive toxicity study, viz. 4, 15, or 60 ppm. Following mating at maturity, the pregnant rats were observed daily for clinical signs of adverse effects, and body weight and feed consumption were recorded. On the day 20th of the gestation, animals were subjected to a necropsy and caesarean section to examine the uterus, ovaries and fetuses for assessment of different parameters of pregnancy and embryo-fetal defects. In this study, no indications of maternal toxicity, adverse effects on the parameters evaluated for the gravid uteri, external abnormalities in the fetuses, soft tissue abnormalities in the fetuses, or skeletal abnormalities in the fetuses were noted. Based on the results of this developmental toxicity study, NBC was found to benon-teratogenic in Sprague-Dawley rat, at the dietary exposure levels of 4, 15, and 60 ppm, equivalent to the dose levels of 0.50, 2.0, or 8.0mg/kg/day, respectively.

Safety of a novel oxygen-coordinated niacin-bound chromium(III) complex (NBC): I. Two-generation reproduction toxicity study.

The objective of this study was to evaluate the effects of a novel oxygen-coordinated niacin-bound chromium(III) complex (NBC) on the reproductive systems of male and female rats, the postnatal maturation and reproductive capacity of their offspring, and possible cumulative effects through multiple generations. Sprague-Dawley rats were maintained on feed containing NBC at dose levels of 0, 4, 15, or 60ppm for 10weeks prior to mating, during mating, and, for females through gestation and lactation, across two generations. For the parents (F(0) and F(1)) and the offspring (F(1) and F(2a)), reproductive parameters such as fertility and mating, gestation, parturition, litters, lactation, sexual maturity and development of offspring were assessed. Results from the current study indicated that dietary exposure of NBC to parental male and female rats of both (F(0) and F(1)) the generations during the premating and mating periods, for both sexes, and during gestation and lactation in case of female rats, did not cause any significant incidence of mortality or abnormal clinical signs. Compared to respective controls, NBC exposure did not affect reproductive performance as evaluated by sexual maturity, fertility and mating, gestation, parturition, litter properties, lactation and development of the offspring. Based on the findings of this study, the parental as well as the offspring no-observed-adverse-effect level for NBC was determined to be greater than 60ppm in diet or equivalent to 7.80 and 8.31mg/kg body weight/day in male and female rats, respectively.

Upflow anaerobic filter for the degradation of adsorbable organic halides (AOX) from bleach composite wastewater of pulp and paper industry.

The removal of AOX from bleach plant effluent of pulp and paper industry was studied using upflow anaerobic filter. In this paper biodegradation of AOX at different concentrations and effect of electron donors like acetate and glucose thereon in an upflow anaerobic filter at 20 d HRT is described. Results showed significant improvement in AOX degradation when electron donors such as acetate and glucose were supplemented to the influent. AOX degradation was 88% at 28 mg AOX L(-1) and 28% at 42 mg AOX L(-1). The percent degradation efficiency was enhanced to 90.7, 90.2, and 93.0 at 28 mg AOX L(-1) when the influent was supplemented with glucose, acetate and both glucose and acetate, respectively. Similarly, the efficiency was 57, 56.6 and 79.6 at 42 mg AOX L(-1) when the influent was supplemented with glucose, acetate and both glucose and acetate, respectively. The GC-MS analysis data indicated that supplementation of the influent with electron donor increased the biodegradability of number of chlorinated organic compounds.

Cutaneous manifestations of chikungunya fever: observations made during a recent outbreak in south India.

UNLABELLED: BACKGROUND; Chikungunya fever is an Aedes mosquito-borne Arbo viral illness with significant morbidity. METHODS: In a recent outbreak of the disease in south India, the dermatologic manifestations of 145 patients attending a tertiary care hospital were recorded. RESULTS: All age groups were affected, including newborns. Some of the cutaneous features were observed during the acute stage of the illness, and others during convalescence or thereafter. Pigmentary changes were found to be the most common cutaneous finding (42%), followed by maculopapular eruption (33%) and intertriginous aphthous-like ulcers (21.37%). Lesions with significant morbidity were generalized vesiculobullous eruptions (2.75%), found only in infants, lymphedema, and intertriginous aphthous-like ulcers. Exacerbation of existing dermatoses, such as psoriasis, and unmasking of undiagnosed Hansen's disease were observed. A perivascular lymphocytic infiltrate was a consistent histopathologic finding in all types of skin lesions. All patients responded well to symptomatic, conservative treatment. CONCLUSIONS: The cutaneous findings hitherto not reported may be the result of the African genotype of the virus detected during this outbreak in India.

Safety of a Novel Calcium/Potassium Salt of Hydroxycitric Acid (HCA-SX): I. Two-Generation Reproduction Toxicity Study.

ABSTRACT (-)-Hydroxycitric acid (HCA), a natural plant extract from the dried fruit rind of Garcinia cambogia, has been reported to inhibit fat synthesis and reduce food intake. The objective of this study was to evaluate the effects of a novel calcium/potassium salt of (-)-hydroxycitric acid (HCA-SX) on the reproductive systems of male and female rats, the postnatal maturation and reproductive capacity of their offspring, and possible cumulative effects through multiple generations. Sprague-Dawley rats (30/sex/group) were maintained on feed containing HCA-SX at dose levels of 0, 1000, 3000, or 10,000 ppm for 10 weeks prior to mating, during mating, and, for females, through gestation and lactation, across two generations. During the period of study, animals were examined daily for signs of clinical toxicity and their body weight and feed consumption were recorded twice a week. For the parents (F(0) and F(1)) and the offspring (F(1) and F(2a)), reproductive parameters such as fertility and mating, gestation, parturition, litters, lactation, sexual maturity, and development of offspring were assessed. At termination, necropsy and histopathological examinations were performed on all animals. Dietary exposure of HCA-SX to parental male and female rats of both (F(0) and F(1)) the generations during the premating and mating periods, for both sexes, and during gestation and lactation in case of female rats, did not reveal any remarkable incidence of mortality or abnormal clinical signs. Compared to respective controls, HCA-SX exposure did not affect feed consumption or body weight at any of the exposure levels. HCA-SX exposure did not affect reproductive performance as evaluated by sexual maturity, fertility and mating, gestation, parturition, litter properties, lactation, and development of the offspring. Based on the results of this study, the parental as well as the offspring no-observed-adverse-effect level for HCA-SX was determined to be greater than 10,000 ppm in diet or equivalent to 1018 and 1524 mg/kg body weight/day in male and female rats, respectively.

Safety of a Novel Calcium/Potassium Saltof (-)-Hydroxycitric Acid (HCA-SX): II.Developmental Toxicity Study in Rats.

ABSTRACT (-)-Hydroxycitric acid (HCA), active constituent (10%-30%) of the dried fruit rind of Garcinia cambogia, is commonly used as a dietary supplement for weight management. The objective of the present study was to evaluate the teratogenic potential of a novel calcium/potassium salt of HCA (HCA-SX) in Sprague-Dawley rats. Due to its potential to affect fat synthesis and reduce food intake, processes that are often crucial in normal fetal development, this teratology study was undertaken as part of a multigeneration reproductive investigation. The animals in this study were selected randomly after weaning from each F(2b) litter of the F(1) generation from the two-generation reproductive toxicity study. To start the teratology study, Sprague-Dawley rat pups ( approximately 30/sex/group) from the F(2b) generation were allowed to grow up to 10 to 12 weeks of age before mating. The rats in the treatment group were exposed directly to HCA-SX through feed, while prior to their weaning, they had indirect exposure to the test material during lactation. The dietary exposure levels were the same as those employed for the two-generation reproductive toxicity study, viz. 1000, 3000, or 10,000 ppm. Following mating at maturity, the pregnant rats were observed daily for clinical signs of adverse effects, and body weight and feed consumption were recorded. On day 20 of gestation, animals were subjected to a necropsy and cesarean section to examine the uterus, ovaries, and fetuses for assessment of different parameters of pregnancy and embryo-fetal defects. Despite a slight (13%) lowering of maternal body weight gain during gestation period in the group receiving 10,000 ppm HCA-SX, no evidence of maternal toxicity, adverse effects on the parameters evaluated for the gravid uteri, external abnormalities in the fetuses, soft tissue abnormalities in the fetuses, or skeletal abnormalities in the fetuses were noted. Based on the results of this developmental toxicity study, conducted in continuation of a two-generation reproductive toxicity study, HCA-SX was not found to be teratogenic in the Sprague-Dawley rat at the dietary exposure levels of 1000, 3000, and 10,000 ppm, equivalent to the dose levels of 103, 352, or 1240 mg/kg/day, respectively.

Formulation and targeting efficiency of Cisplatin engineered solid lipid nanoparticles.

The present study is aimed at the overall improvement in the efficacy, reduced toxicity and enhancement of therapeutic index of cisplatin. Solid lipid nanoparticulate delivery system of cisplatin has been developed by microemulsification method by using stearic acid, soy lecithin 95% and sodium glycolate. The formulations were then characterized with respect to size and its surface morphology, zeta potential, entrapment efficiency, in vitro drug release profile, in vivo drug targeting studies and its stability under specific conditions. The formulated solid lipid nanoparticles were oval with a diameter ranging from 250 nm to 500 nm. The lowest entrapment efficiency was found to be 47.59% and highest was found to be 74.53%. The zeta potential was in the range of -9.8 to -11.2 mv. In vitro release study was analyzed using various mathematical models. Highest cumulative percent drug release was observed with F-1 (97.22 %) and lowest with F-4 (78.43%) in 16 h. The in vivo result of formulated solid lipid nanoparticles of cisplatin reveals that the drug is preferentially targeting to liver followed by brain and lungs.

A point mutation in the two-component regulator PhoP-PhoR accounts for the absence of polyketide-derived acyltrehaloses but not that of phthiocerol dimycocerosates in Mycobacterium tuberculosis H37Ra.

Similarities between Mycobacterium tuberculosis phoP-phoR mutants and the attenuated laboratory strain M. tuberculosis H37Ra in terms of morphological and cytochemical properties, lipid content, gene expression and virulence attenuation prompted us to analyze the functionality of this two-component regulator in the latter strain. Sequence analysis revealed a base substitution resulting in a one-amino-acid change in the likely DNA-binding region of PhoP in H37Ra relative to H37Rv. Using gel-shift assays, we show that this mutation abrogates the ability of the H37Ra PhoP protein to bind to a 40-bp segment of its own promoter. Consistent with this result, the phoP gene from H37Rv but not that from H37Ra was able to restore the synthesis of sulfolipids, diacyltrehaloses and polyacyltrehaloses in an isogenic phoP-phoR knock-out mutant of M. tuberculosis Moreover, complementation of H37Ra with phoP from H37Rv fully restored sulfolipid, diacyltrehalose and polyacyltrehalose synthesis, clearly indicating that the lack of production of these lipids in H37Ra is solely due to the point mutation in phoP. Using a pks2-3/4 knock-out mutant of M. tuberculosis H37Rv, evidence is further provided that the above-mentioned polyketide-derived acyltrehaloses do not significantly contribute to the virulence of the tubercle bacillus in a mouse model of infection. Reasons for the attenuation of H37Ra thus most likely stand in other virulence factors, many of which are expected to belong to the PhoP regulon and another of which, unrelated to PhoP, appears to be the lack of production of phthiocerol dimycocerosates in this strain.

Identification of key structural determinants of the IntI1 integron integrase that influence attC x attI1 recombination efficiency.

The integron platform codes for an integrase (IntI) from the tyrosine family of recombinases that mediates recombination between a proximal double-strand recombination site, attI and a single-strand target recombination site, attC. The attI site is only recognized by its cognate integrase, while the various tested attCs sites are recombined by several different IntI integrases. We have developed a genetic system to enrich and select mutants of IntI1 that provide a higher yield of recombination in order to identify key protein structural elements important for attC x attI1 recombination. We isolated mutants with higher activity on wild type and mutant attC sites. Interestingly, three out of four characterized IntI1 mutants selected on different substrates are mutants of the conserved aspartic acid in position 161. The IntI1 model we made based on the VchIntIA 3D structure suggests that substitution at this position, which plays a central role in multimer assembly, can increase or decrease the stability of the complex and accordingly influence the rate of attI x attC recombination versus attC x attC. These results suggest that there is a balance between the specificity of the protein and the protein/protein interactions in the recombination synapse.

Safety evaluation of a standardized phytochemical composition extracted from Bacopa monnieri in Sprague--Dawley rats.

BacoMind is an enriched phytochemical composition derived from Bacopa monnieri, a common medicinal plant having multiple uses in the traditional system of medicine and particularly used as a memory enhancing agent for centuries. The plant and its extracts have been evaluated for anti-inflammatory, cardio tonic, sedative and neuro-muscular blocking activities. In view of the extensive use of this plant, BacoMind , standardized to bioactive compounds was evaluated in a series of toxicity studies, to confirm the safety of its usage. BacoMind , on single oral administration had a median lethal dose of 2,400 mg/kg in Sprague-Dawley rats. In a 14 day repeated dose oral toxicity study in rats, except for mild lowering in body weight gain in male rats, it was found to be tolerated well up to the dose of 500 mg/kg. A subchronic oral toxicity study for 90 days in rats at the dose levels of 85, 210 and 500 mg/kg did not reveal any evidence of toxicity with respect to clinical signs, neurological examination, food consumption, body weight gain, haematological and blood biochemistry parameters. The absolute and relative organ weight of vital organs did not differ significantly from that of the control. Necropsy and histopathological examination, did not reveal any remarkable and treatment related changes. A no-observed adverse effect level of 500 mg/kg body weight was established in rats.