Enhancing the photocatalytic performance of surface - Treated SnO2 hierarchical nanorods against methylene blue dye under solar irradiation and biological degradation.

Surfactant -treated tin oxide (SnO2) hierarchical nanorods were successfully synthesized through hydrothermal technique. The X-ray diffraction analysis showed the prepared SnO2 possesses tetragonal rutile structure having appreciable crystallinity with crystallite sizes in the range of 110 nm-120 nm. UV-visible diffuse reflectance absorption spectra confirm that the better visible light absorption band of SnO2 hierarchical nanorods have red shift compared to the pure SnO2. Fourier transform infrared spectroscopy (FTIR) study evident that the as-prepared SnO2 nanorods encompass the characteristic bands of SnO2 nanostructures. The morphological analyses of prepared materials were performed by FESEM, which shows that hierarchal nanorods and complex nanostructures. EDX analyses disclose all the samples are composed of Sn and O elements. The photocatalytic performance of the prepared surfactant treated SnO2 hierarchical nanorods was evaluated using methylene blue (MB) dye removal under direct natural sunlight. Recycling experiment results of CTAB - SnO2 nanorods and photocatalytic reaction mechanism also discussed in detail.

In vitro antioxidant and, α-glucosidase inhibitory activities and comprehensive metabolite profiling of methanol extract and its fractions from Clinacanthus nutans.

BACKGROUND: This study was aimed to evaluate antioxidant and α-glucosidase inhibitory activity, with a subsequent analysis of total phenolic and total flavonoid content of methanol extract and its derived fractions from Clinacanthus nutans accompanied by comprehensive phytochemical profiling. METHODS: Liquid-liquid partition chromatography was used to separate methanolic extract to get hexane, ethyl acetate, butanol and residual aqueous fractions. The total antioxidant activity was determined by 2,2-diphenyl-1-picrylhydrazy (DPPH) radical scavenging and ferric reducing antioxidant power assay (FRAP). The antidiabetic activity of methanol extract and its consequent fractions were examined by α-glucosidase inhibitory bioassay. The chemical profiling was carried out by gas chromatography coupled with quadrupole time-of-flight mass spectrometry (GC Q-TOF MS). RESULTS: The total yield for methanol extraction was (12.63 ± 0.98) % (w/w) and highest fractionated value found for residual aqueous (52.25 ± 1.01) % (w/w) as compared to the other fractions. Significant DPPH free radical scavenging activity was found for methanolic extract (63.07 ± 0.11) % and (79.98 ± 0.31) % for ethyl acetate fraction among all the fractions evaluated. Methanol extract was the most prominent in case of FRAP (141.89 ± 0.87 µg AAE/g) whereas most effective reducing power observed in ethyl acetate fraction (133.6 ± 0.2987 µg AAE/g). The results also indicated a substantial α-glucosidase inhibitory activity for butanol fraction (72.16 ± 1.0) % and ethyl acetate fraction (70.76 ± 0.49) %. The statistical analysis revealed that total phenolic and total flavonoid content of the samples had the significant (p < 0.05) impact on DPPH free radical scavenging and α-glucosidase inhibitory activity. CONCLUSION: Current results proposed the therapeutic potential of Clinacanthus nutans, especially ethyl acetate and butanol fraction as chemotherapeutic agent against oxidative related cellular damages and control the postprandial hyperglycemia. The phytochemical investigation showed the existence of active constituents in Clinacanthus nutans extract and fractions.

Genomic and enzymatic evidence for acetogenesis among multiple lineages of the archaeal phylum Bathyarchaeota widespread in marine sediments.

Members of the archaeal phylum Bathyarchaeota are widespread and abundant in the energy-deficient marine subsurface sediments. However, their life strategies have remained largely elusive. Here, we provide genetic evidence that some lineages of Bathyarchaeota are acetogens, being capable of homoacetogenesis, a metabolism so far restricted to the domain Bacteria. Metabolic reconstruction based on genomic bins assembled from the metagenome of deep-sea subsurface sediments shows that the metabolism of some lineages of Bathyarchaeota is similar to that of bona fide bacterial homoacetogens, by having pathways for acetogenesis and for the fermentative utilization of a variety of organic substrates. Heterologous expression and activity assay of the acetate kinase gene ack from Bathyarchaeota, demonstrate further the capability of these Bathyarchaeota to grow as acetogens. The presence and expression of bathyarchaeotal genes indicative of active acetogenesis was also confirmed in Peru Margin subsurface sediments where Bathyarchaeota are abundant. The analyses reveal that this ubiquitous and abundant subsurface archaeal group has adopted a versatile life strategy to make a living under energy-limiting conditions. These findings further expand the metabolic potential of Archaea and argue for a revision of the role of Archaea in the carbon cycle of marine sediments.

Metabolic alteration in obese diabetes rats upon treatment with Centella asiatica extract.

ETHNOPHARMACOLOGICAL RELEVANCE: 'Pegaga' is a traditional Malay remedy for a wide range of complaints. Among the 'pegaga', Centella asiatica has been used as a remedy for diabetes mellitus. Thus, we decided to validate this claim by evaluating the in vivo antidiabetic property of C. asiatica (CA) on T2DM rat model using the holistic (1)H NMR-based metabolomics approach. METHOD: In this study, an obese diabetic (mimic of T2DM condition) animal model was developed using Sprague-Dawley rats fed with a high-fat diet and induced into diabetic condition by the treatment of a low dose of streptozotocin (STZ). The effect of C. asiatica extract on the experimental animals was followed based on the changes observed in the urinary and serum metabolites, measured by (1)H NMR of urine and blood samples collected over the test period. RESULTS: A long-term treatment of obese diabetic rats with CA extract could reverse the glucose and lipid levels, as well as the tricarboxylic acid cycle and amino acid metabolic disorders, back towards normal states. Biochemical analysis also showed an increase of insulin production in diabetic rats upon treatment of CA extract. CONCLUSION: This study has provided evidence that clearly supported the traditional use of CA as a remedy for diabetes. NMR-based metabolomics was successfully applied to show that CA produced both anti-hyperglycemic and anti-hyperlipidemic effects on a rat model. In addition to increasing the insulin secretion, the CA extract also ameliorates the metabolic pathways affected in the induced diabetic rats. This study further revealed the potential usage of CA extract in managing diabetes mellitus and the results of this work may contribute towards the further understanding of the underlying molecular mechanism of this herbal remedy.

Fetal renal anomaly: factors that predict survival.

OBJECTIVE: To find out the relative prevalence of renal anomalies detected in the antenatal period, and to look at factors that predict the postnatal outcome. METHODS: In this prospective study, all antenatal-detected renal anomalies booked at the tertiary health centre were evaluated and counselled. Aspects such as type of renal anomaly, oligohydramnios and presence of additional anomalies were noted. Stillborn babies underwent autopsy; all live born babies were followed for one year. Appropriate statistical analyses were performed to compare the antenatal factors with outcomes. RESULTS: Renal anomalies were detected in 136 out of 587 cases with major fetal anomalies. Most of the women were primiparous (65.4%). The mean gestation at presentation was 30 weeks; in 12 cases, diagnosis was possible before 20 weeks (8.8%). Antenatal hydronephrosis was the most commonly seen anomaly, with 61 cases; this was followed by bilateral cystic kidney in 50 cases. Out of the 136 cases, 12 (8.8%) underwent termination of pregnancy and 60 (44.1%) babies were stillborn. Autopsy was performed in 58 out of 72 (80.6%) cases after consent. Karyotyping was performed in 49 cases and abnormalities were detected in two (4.1%) of them. A total of 64 (47.1%) babies were live born; after one year, 49 (36.0%) of them were alive. Postnatal survival was highest in unilateral disease (85.7%). In cases with oligohydramnios, there was only 3.4% survival after one year; none of the cases with cystic kidney and oligohydramnios survived. The period of gestation at presentation of non-survivors was 25.9 weeks compared to 32.5 weeks with survivors. Among the cases with extra renal anomaly, 7.0% survived; none of the cases with associated cranio-vertebral defect or polydactyly survived after a year. CONCLUSION: Out of the different renal pathologies that were diagnosed, survival was highest in the unilateral group. The factors associated with poor prognosis included bilateral disease, absence of amniotic fluid and presence of associated malformation.

Epigenetic regulation of the secreted frizzled-related protein family in human glioblastoma multiforme.

Glioblastoma multiforme (GBM) are intracranial tumors of the central nervous system and the most lethal among solid tumors. Current therapy is palliative and is limited to surgical resection followed by radiation therapy and temozolomide treatment. Aberrant WNT pathway activation mediates not only cancer cell proliferation but also promotes radiation and chemotherapeutic resistance. WNT antagonists such as the secreted frizzled-related protein (sFRP) family have an ability to sensitize glioma cells to chemotherapeutics, decrease proliferation rate and induce apoptosis. During tumor development, sFRP genes (1-5) are frequently hypermethylated, causing transcriptional silencing. We investigated a possible involvement of methylation-mediated silencing of the sFRP gene family in human GBM using four human glioblastoma cell lines (U87, U138, A172 and LN18). To induce demethylation of the DNA, we inhibited DNA methyltransferases through treatment with 5-azacytidine. Genomic DNA, RNA and total protein were isolated from GBM cells before and after treatment. We utilized bisulfite modification of genomic DNA to examine the methylation status of the respective sFRP promoter regions. Pharmacological demethylation of the GBM cell lines demonstrated a loss of methylation in sFRP promoter regions, as well as an increase in sFRP gene-specific mRNA abundance. Western blot analysis demonstrated an increased protein expression of sFRP-4 and increased levels of phosphorylated-ß-catenin. These data indicate an important role of methylation-induced gene silencing of the sFRP gene family in human GBM.

Investigating a new approach to film casting for enhanced drug content uniformity in polymeric films.

Films prepared by conventional casting onto trays such as teflon-coated perspex trays (TCPTs) suffer from poor drug content uniformity. The aim of this study was to prepare a silicone-molded tray (SMT) with individual wells for film casting and to evaluate it in terms of enhancing drug content uniformity. Films were prepared by solvent evaporation or emulsification and cast onto TCPT and SMT. Preparation of films by the SMT method was superior in terms of meeting drug content uniformity requirements. As compared with the TCPT method, the SMT casting method also reduced the variability in mucoadhesivity, drug release, and film thickness. Reproducibility of the SMT method was demonstrated in terms of drug content, mucoadhesion, and drug release.

Formulation of monolayered films with drug and polymers of opposing solubilities.

The aim of this study was to prepare and characterise monolayered multipolymeric films (MMFs) comprising of a hydrophilic drug (Propranolol HCl) (PHCl) and polymers of opposing solubilities. Films were prepared by emulsification and casted by a new approach using a silicone-molded tray with individual wells. MMFs comprising of PHCl with Eudragit 100 (EUD100) and Chitosan (CHT), i.e. films with drug and polymers of opposing solubilities were successfully prepared (PHCl:EUD100:CHT; 1:10:0.5) and demonstrated uniform and reproducible drug content (100.71+/-2.66%), thickness (0.442+/-0.030 mm), mucoadhesivity (401.40+/-30.73 mN) and a controlled drug release profile. Drug release followed Higuchi's square-root model. Maximum swelling of the films occurred after 1h and 28.26% of the films eroded during the 8-h test period. Mechanical testing revealed that the MMFs displayed a greater abrasion resistance, were more elastic and also required more energy to break, rendering them tougher and more suitable for buccal delivery than the monopolymeric PHCl:EUD100 film. The inclusion of CHT to the film led to a more porous surface morphology. The surface pH of the films remained constant at neutral pH. This study confirmed the potential of the above MMFs as a promising candidate for buccal delivery of PHCl.

Perturbations in eosinophil homeostasis following treatment of lymphatic filariasis.

Treatment of patients with patent Wuchereria bancrofti infection results in an acute clinical reaction and peripheral eosinophilia. To investigate the dynamics of the eosinophil response, changes in eosinophil activation and degranulation and plasma levels of eosinophil-active chemokines and cytokines were studied in 15 microfilaremic individuals in south India by sequential blood sampling before and after administration of 300 mg of diethylcarbamazine (DEC). Clinical symptoms occurred within 24 h. Plasma interleukin-5 (IL-5) and RANTES levels peaked 1 to 2 days posttreatment, preceding a peak peripheral eosinophil count at day 4. Major basic protein secretion from eosinophils paralleled IL-5 secretion, while levels of eosinophil-derived neurotoxin peaked at day 13 after treatment. Expression of the activation markers HLA-DR and CD25 on eosinophils rose markedly immediately after treatment, while expression of VLA-4 and alpha4beta7 showed an early peak within 24 h and a second peak at day 13. Thus, the posttreatment reactions seen in filarial infections can be divided into an early phase with killing of microfilariae, clinical symptomatology, increases in plasma IL-5 and RANTES levels, and eosinophil activation and degranulation and a later phase with expression of surface integrins on eosinophils, recruitment of eosinophils from the bone marrow to tissues, and clearance of parasite antigen.

Effect of rufloxacin on in-vitro proliferation and differentiation of human mononuclear cells.

We investigated the effects of rufloxacin, a new, long acting fluoroquinolone, on the growth and differentiation of human peripheral blood mononuclear cells (MNC) stimulated with T- and B-cell mitogenic agents. Rufloxacin inhibited 3H-thymidine incorporation into MNC stimulated with phytohaemagglutinin (PHA) and pokeweed mitogen (PWM) in a dose-dependent manner. The concentrations of rufloxacin required to inhibit 1/2 maximal proliferation of T- and B-cells were 62 and 33.5 mg/L respectively. Rufloxacin, at clinically achievable serum levels (less than 10 mg/L), was found not to inhibit PHA-induced T-cell differentiation as assessed by IL-2 production, IL-2 receptor expression and the expression of cell differentiation markers (CD4 and CD8). However, higher concentrations of rufloxacin (10 and 50 mg/L) markedly inhibited B-cell differentiation in-vitro as determined by the measurement of immunoglobulin production by MNC stimulated with PWM. The clinical relevance of our in-vitro findings remains to be elucidated.

Evaluation of temafloxacin in a rat model of intra-abdominal abscess.

The in-vitro activity of temafloxacin, a new fluoroquinolone, was evaluated in an experimental model of intra-abdominal abscess in rats. Mixed aerobic-anaerobic infection was induced by intraperitoneal implantation of gelatin capsules containing Bacteroides fragilis, Escherichia coli, and sterile rat faeces. Temafloxacin was highly active with a 90.9% cure rate in comparison with no treatment (no cures; P less than 0.0001), and as active as a combination of clindamycin and gentamicin (100% cure rate; P greater than 0.05). Temafloxacin (12 mg/dose) gave rise to serum concentrations that exceeded the MIC values of both microorganisms for at least 8 h.

Association of increased mycobacterium growth inhibitory factor with antituberculous immunity.

Cell-mediated immune mechanisms (CMI) were studied in 51 patients of pulmonary tuberculosis to evaluate the role of mycobacterium growth inhibitory factor in prognosis of the infection, before and after the administration of anti-tubercular drugs. Twenty five Mantoux negative individuals who were subsequently bacille Calmette-Guérin (BCG) vaccinated and 25 Mantoux positive, non-tuberculous controls were included in the study. Their clinical assessment was compared with skin sensitivity (Mantoux); lymphocyte transformation (LT) after stimulation with phytohaemagglutinin (PHA) and purified protein derivative (PPD); macrophage migration inhibitory factor (MIF), mycobacteria growth inhibitory factor (Myco IF) and listerial growth inhibitory factor (List IF). The tests were carried out at the beginning of the treatment and at intervals of three months, extending to one year. In the case of Mantoux positive controls, tests were carried out only once. It was found that Mantoux reaction had no correlation with LT, MIF, Myco IF and List IF. Both MIF and Myco IF, were significantly elevated in improving patients, whereas increase in List IF was not significant. An important finding was that Myco IF was at a higher level in improving patients whereas in those not responding to chemotherapy it was low.

The effects of exposure time, drug concentration, and temperature on the activity of ethambutol versus Mycobacterium tuberculosis.

In a series of dynamic in vitro studies designed to assess the activity of ethambutol (EMB) against Mycobacterium tuberculosis, we made the following observations. Ethambutol showed bactericidal action with 10 micrograms/ml concentration when in constant contact with M. tuberculosis. At a lower concentration, bactericidal action was evident up to 6 days; after that time, this effect was lost owing to the development of drug-resistant mutants. The bactericidal action of ethambutol in this model was similar to that of rifampin and isoniazid. Pulsed exposure for 96 h caused a four-log reduction in cfu counts, but the growth resumed rapidly. The bactericidal action of ethambutol was maximal at 37 degrees C and less at low temperatures. Ethambutol showed little activity against cultures growing at 8 degrees C continuously that were incubated for only 1 h at 37 degrees C. Against cultures growing at 8 degrees C that were brought to 37 degrees C for 6 h, its action was similar to that of rifampin. Ethambutol combined with other drugs showed bactericidal action, although the activity was less than that of the combination isoniazid-streptomycin.

The beige mouse model for Mycobacterium avium complex (MAC) disease: optimal conditions for the host and parasite.

We extended our earlier studies to establish the beige (C57B1/6/bgJ/bgJ) mouse model for experimental acute infections with Mycobacterium avium complex (MAC). Optimal conditions of the host and the parasites have been determined. Mice bred at our center showed similar responses to those obtained from Jackson Laboratories, the original supplier. Both male and female mice showed similar responses, but older mice in both sexes showed less susceptibility than younger mice. Strain 101 of MAC showed remarkable consistency in its pathogenicity to beige mice, as evidenced by the distribution of colony forming unit (CFU) counts at various time points after intravenous challenge, in several experiments. CFU counts showed an association with the dose of challenge, and histopathological observations.

Virulence of Mycobacterium avium complex strains from acquired immune deficiency syndrome patients: relationship with characteristics of the parasite and host.

The virulence of 24 strains of Mycobacterium avium complex (MAC) isolated from patients with acquired immune deficiency syndrome (AIDS) was assessed using the beige mouse model. Most changes in colony forming unit (cfu) counts in spleen and lungs, and spleen weights occurred between days 1 and 14, with comparatively smaller changes 14-28 days postinfection. The virulence was assessed by a score formulated from the four most useful parameters: mortality, spleen cfu, lung cfu and spleen weights at 28 days. The scores of the 24 strains showed a normal distribution; four strains falling above one standard deviation from the mean were classified as high virulent, those four falling below one standard deviation as low virulent, and the remaining 16 as of intermediate virulence. Virulence was associated with the total number of plasmids and the occurrence of large plasmids (greater than 100 MDa) in the MAC strains. There was an inverse correlation between virulence and the organism's capacity to trigger the release of oxygen metabolites from peritoneal macrophages. Macrophages from mice infected with the MAC strains of different degrees of virulence released superoxide anion (O2-) with a peak at two weeks, the peak levels bearing an inverse correlation to virulence. No association was seen between virulence and source of specimens, biochemical characteristics, drug susceptibility, serotypes or phage types.

Susceptibility of beige mice to Mycobacterium avium complex infections by different routes of challenge.

We have studied the susceptibility of beige (C57Bl/6/bgJ/bgJ) mice to a virulent strain of Mycobacterium avium complex (MAC) (101) by intravenous, intraperitoneal, intranasal, oral, and intrarectal routes. Consistent with our earlier findings, intravenous challenge resulted in high mortality and colony-forming unit (CFU) counts of recoverable organisms from spleens, lungs, livers, and lymph nodes, plus high levels of mortality. Intraperitoneal challenge resulted in high organ CFU counts but no mortality. Of relevance to the sexual practice of certain homosexual patients with AIDS is the intrarectal route of inoculation, which resulted in extensive involvement of the visceral organs with MAC disease. Multiple challenges by intravenous, oral, or rectal routes resulted in higher CFU counts than did single exposures.

In vivo activity of amikacin alone or in combination with clofazimine or rifabutin or both against acute experimental Mycobacterium avium complex infections in beige mice.

The in vivo activity of amikacin, used alone or in combination with rifabutin or clofazimine or both, was assessed in the treatment of early and established Mycobacterium avium complex infections in beige mice. Amikacin given alone at a dose of 50 mg/kg, in one, two, or three divided doses, showed remarkable activity. Addition of clofazimine increased the activity significantly, but addition of the third drug, rifabutin, did not further improve the results. Amikacin-containing regimens are worthy of consideration for investigations in patients with M. avium complex infections.

Enhanced effect of liposome-encapsulated amikacin on Mycobacterium avium-M. intracellulare complex infection in beige mice.

We examined the therapeutic effects of free and liposome-encapsulated amikacin on Mycobacterium avium-M. intracellulare complex infection by using the beige-mouse model of the disease. In the first series of studies, intravenous administration of four weekly doses of 5 mg of amikacin per kg encapsulated in large (approximately 0.4-micron diameter), unilamellar liposomes arrested the growth of M. avium-M. intracellulare complex organisms in the liver, as measured by CFU counts. M. avium-M. intracellulare complex levels in untreated animals and in those treated with the same dose of free amikacin increased by several orders of magnitude over 8 weeks. Liposome-encapsulated amikacin was also effective against M. avium-M. intracellulare complex organisms in the spleen and kidneys, reducing the CFU counts by about 1,000-fold compared with those of both untreated controls and free-drug-treated mice. In the lungs, a slight reduction in CFU was observed in the liposome-encapsulated-amikacin-treated group, but only at the 8-week point. Neither free nor liposome-encapsulated amikacin reduced the colony counts in the lymph nodes compared with those of control animals. Reductions in CFU in all organs greater than those caused by the liposome preparation could be achieved by intramuscular administration of free amikacin, but only at a 10-fold-higher dose given 6 days a week for 8 weeks. In the second series of studies, we investigated the effects of (i) doubling the dose of liposome-encapsulated amikacin and (ii) increasing the size of the liposomes and prolonging the treatment to five injections. Administration of 10 mg of amikacin per kg in liposomes 2 to 3 micrometer in diameter was more effective in the liver than 5 or 10 mg of amikacin per kg in liposomes 0.2 micrometer in diameter. A slight reduction in the CFU levels in the lungs was observed with the higher dose, irrespective of liposome size. Our results indicate that liposome-based delivery of amikacin enhances its anti-M. intracellulare complex activity, particularly in the liver, spleen, and kidney, and may therefore improve the therapy of this disease.

Activity of amikacin against Mycobacterium avium complex under simulated in vivo conditions.

We studied the activity of amikacin against Mycobacterium avium complex strain 101 by using continuous-level, changing concentrations which simulated levels in serum in a patient, and pulsed exposures. Amikacin at a concentration of 5 or 15 micrograms/ml showed rapid bactericidal action following constant exposure of the organisms. With the in vitro model, using a peak concentration of 10 or 20 micrograms/ml, complete sterilization was obtained by day 7. In pulsed-exposure studies, a minimum period of contact of 72 or 96 h at a concentration of 10 micrograms/ml was needed for complete sterilization.

Association of plasmids and virulence of Mycobacterium avium complex.

Mycobacterium avium complex strain LR25, which carries 3 plasmids, was shown to be of high virulence in beige mice as judged by high mortality and a progressive increase in organisms in the spleen and lungs determined by counting the number of colony-forming units. Strain LR163, a "cured" derivative of LR25 that lacks all 3 plasmids, was of low virulence as judged by these criteria. The relative virulence of the strains was confirmed by studies of oxygen metabolite (superoxide anion and hydrogen peroxide) release from resident and BCG-activated mouse peritoneal macrophages. In contrast to loss of virulence, no significant change was seen in drug susceptibility.