Can geometry control the coordination behaviour of 2-hydroxy-1-naphthaldehyde-N(4)-phenylthiosemicarbazone? A study towards its origin

2-Hydroxy-1-naphthaldehyde-N(4)-phenylthiosemicarbazone [H₂-Nap-ptsc] (H₂L) was reacted with square planar complexes of the type [MCl₂(EPh₃)₂] (where M = Ni or Pd; E = P or As) and octahedral [RuHCl(CO)(PPh₃)₃]. Square planar complexes ([Ni(Nap-ptsc)PPh₃)]; [Pd(Nap-ptsc)PPh₃)]; [Pd(Nap-ptsc)AsPh₃)]) gave products with only ONS tri coordinated thiosemicarbazone whereas octahedral ruthenium complex gave two products, one with NS and the other with ONS coordination. It is interesting to note that NS bi coordination leads to the formation of more strained four member ring. All the new complexes have been characterised by analytical, spectral, crystallographic and electrochemical methods.     

Effect of corn-steep liquor on growth and mosquito larvicidal activity of Bacillus thuringiensis var israelensis de Barjac 1978 and B. sphaericus Neide 1904.

Influence of corn steep liquor on the cell yield and toxicity of three strains of B. thuringiensis var israelensis and two strains of B. sphaericus was studied and compared with peptone-yeast extract using a laboratory fermentor. Large increase in the cell yield of all the three strains of B. thuringiensis var israelensis was observed when cornsteep liquor was used as the sole nitrogen source. Significant increase in toxicity was also observed in B. thuringiensis var israelensis strains B17 and B113. Among the two B. sphaericus strains tested, the strain 1593 showed no significant change in cell yield and toxicity, whereas the strain VCRC B42 showed increased cell yield and toxicity in this medium. The results indicate that cornsteep liquor can effectively replace both peptone and yeast extract in the media presently used for large scale multiplication of the two larvicidal bacilli.     

Sediment Heavy Metal Contents,Ostracod Toxicity and Risk Assessment in Tropical Freshwater Lakes,Tamil Nadu,India

ABSTRACT

Coimbatore is one of the industrial cities in Tamil Nadu, India, which has been experiencing rapid urbanization and population growth. Coimbatore is also known for its unique freshwater lakes environment and serves as a rich ecosystem. However, the assessment of heavy metal levels in aquatic environments is limited. This study was aimed to investigate physicochemical parameters, heavy metals level and sources, and ecotoxicity in sediments collected from five different lakes in Coimbatore. The concentrations of heavy metals (Cr, Cu, Zn, As, Cd, and Pb) in sediments were determined by Inductive Coupled Plasma-Mass Spectroscopy (ICP-MS). Hg level was measured using Advanced Mercury Analyzer (AMA). The determined heavy metal concentrations in sediments varied significantly according to the lake location and consistent with local human linked anthropogenic activities. The metal concentrations in urban lakes were exceeding both the Sediment Quality Guidelines (SQGs) and the probable effect levels” (PELs) mostly; e.g., in sediments from the Lake Ukkadam, the values of 5.08 and 203.32 mg kg-1 dry weight were observed for Hg and Cu, respectively. The ecotoxicity test with ostracods exposed to the sediment samples revealed that mortality ranged between 6 and 23% for countryside lakes and 28 and 88% for the lakes within urban Zone. We used Spearman rank-order correlation and Principal components analysis (PCA) to assess the sources of pollutants and if they related to anthropogenic pressure and eutrophication of lakes. The main sources of heavy metals from studied lakes differed significantly. Urban and industrial effluents were dominant sources in urban lakes. Agricultural runoff, domestic wastes, and natural weathering were responsible for the metal sources in country lakes. This study provides baseline information on the heavy metal pollution status of sediments in the freshwater lakes in Coimbatore, which will be useful for pollution control measures to prevent possible metal sources on these lakes and impose appropriate management practices and continuous monitoring by relevant authorities.     

Mitigation of cocaine-mediated mitochondrial damage,defective mitophagy and microglial activation by superoxide dismutase mimetics

ABSTRACT

Although cocaine exposure has been shown to potentiate neuroinflammation by upregulating glial activation in the brain, the role of mitophagy in this process remains an enigma. In the present study, we sought to examine the role of impaired mitophagy in cocaine-mediated activation of microglia and to determine the ameliorative potential of superoxide dismutase mimetics in this context. Our findings demonstrated that exposure of mouse primary microglial cells (mPMs) to cocaine resulted in decreased mitochondrial membrane potential, that was accompanied by increased expression of mitophagy markers, PINK1 and PRKN. Exposure of microglia to cocaine also resulted in increased expression of DNM1L and OPTN with a concomitant decrease in the rate of mitochondrial oxygen consumption as well as impaired mitochondrial functioning. Additionally, in the presence of cocaine, microglia also exhibited upregulated expression of autophagosome markers, BECN1, MAP1LC3B-II, and SQSTM1. Taken together, these findings suggested diminished mitophagy flux and accumulation of mitophagosomes in the presence of cocaine. These findings were further confirmed by imaging techniques such as transmission electron microscopy and confocal microscopy. Cocaine-mediated activation of microglia was further monitored by assessing the expression of the microglial marker (ITGAM) and the inflammatory cytokine (Tnf, Il1b, and Il6) mRNAs. Pharmacological, as well as gene-silencing approaches aimed at blocking both the autophagy/mitophagy and SIGMAR1 expression, underscored the role of impaired mitophagy in cocaine-mediated activation of microglia. Furthermore, superoxide dismutase mimetics such as TEMPOL and MitoTEMPO were shown to alleviate cocaine-mediated impaired mitophagy as well as microglial activation.

Abbreviations: 3-MA: 3-methyladenine; Δψm: mitochondrial membrane potential; ACTB: actin, beta; AIF1: allograft inflammatory factor 1; ATP: adenosine triphosphate; BAF: bafilomycin A₁; BECN1: beclin 1, autophagy related; CNS: central nervous system; DNM1L: dynamin 1 like; DMEM: Dulbecco modified Eagle medium; DAPI: 4,6-Diamidino-2-phenylindole; DRD2: dopamine receptor D2; ECAR: extracellular acidification rate; FBS: fetal bovine serum; FCCP: Trifluoromethoxy carbonylcyanide phenylhydrazone; GAPDH: glyceraldehyde-3-phosphate dehydrogenase; IL1B: interleukin 1, beta; IL6: interleukin 6; ITGAM: integrin subunit alpha M; MAP1LC3B: microtubule-associated protein 1 light chain 3 beta; mPMs: mouse primary microglial cells; MRC: maximal respiratory capacity; NFKB: nuclear factor kappa B; NLRP3: NLR family pyrin domain containing 3; NTRK2: neurotrophic receptor tyrosine kinase 2; OCR: oxygen consumption rate; OPTN: optineurin; PBS: phosphate buffered saline; PINK1: PTEN induced putative kinase 1; PRKN: parkin RBR E3 ubiquitin protein ligase; ROS: reactive oxygen species; siRNA: small interfering RNA; SQSTM1: sequestosome 1; TNF: tumor necrosis factor     

An enzyme linked immunosorbent assay for monitoring Bacillus sphaericus toxin.

Larvicidal proteins of B. sphaericus H5a5b (strain VCRC B42), purified by ion-exchange chromatography were used to raise antibodies in rabbits. The antibodies were specific in reacting to alkali-solubilized fractions from whole cells of toxic strains only. Ouchterlony immunodiffusion showed homology in toxin structure between strains of different serotype. A sandwich ELISA using avidin-biotin amplification was standardized. The lowest detectable limit was 6.25 ng/ml. Near linear quantitative binding of the antigen was found in the range 25-200 ng/ml. The growth, toxin level and LC50 values during various stages of fermentation of B. sphaericus strains 1593 and B42 were compared. There was significant correlation between LC50 values and toxin levels as measured by ELISA.