Ab initio study of the mechanism of the reaction ClO + O --> Cl + O2

Abstract. Ab initio investigation on the reaction mechanism of ClO + O --> Cl + O2 reaction has been performed using correlation consistent triple zeta basis set. The geometry and frequency of the reactants, products, minimum energy geometries and transition states are obtained using MP2 method and energetics are obtained at the QCISD(T)//MP2 level of theory. Primarily, a possible reaction mechanism is obtained on the basis on IRC calculations using MP2 level of theory. To obtain true picture of the reaction path, we performed IRC calculations using CASSCF method with a minimal basis set 6-31G**. Some new equilibrium geometries and transition states have been identified at the CASSCF level. Energetics are also obtained at the QCISD(T)//CASSCF method. Possible reaction paths have been discussed, which are new in literature. Heat of reaction is found to be consistent with the experimental data. Bond dissociation energies to various dissociation paths are also reported.

Effect of testicular tissue lysate on developmental competence of porcine oocytes matured and fertilized in vitro

The objective of the present study was to investigate the effect of testicular tissue lysate (TTL) on developmental competence of germinal vesicle (GV) stage porcine oocytes. Two types of TTL were prepared through repeated freeze-thaw in liquid nitrogen, one from whole testicular tissue (wTTL) and other from either of four different sections of testes, namely just beneath the tunica albuginea (TA), from the transitional area between the seminiferous cord/tubules and the mediastinum testis (TR) and from the intermediate area (parenchymal tissue origin) and CE (cauda epididymis origin). The whole or section-wise TTL treatments were given for 44 hr during in vitro maturation (IVM). Oocyte maturation was done in either of the two media, namely defined (high-performance basic medium for porcine oocyte maturation, commercially available) and serum containing (TCM199). After maturation, oocytes were co-incubated with fresh spermatozoa for 6 hr and then transferred to embryo culture media. Treatment of GV stage oocytes with wTTL (1 mg/ml) increased the cleavage and morula percentage rate (69.23 ± 6.23 and 48.15 ± 6.77, respectively) than that of their control (58.33 ± 8.08 and 32.54 ± 5.53, respectively) in defined media, and in serum-containing media, cleavage and morula percentage rate were almost equal in both treatment (54.56 ± 7.79 and 34.70 ± 6.78, respectively) and control (59.52 ± 8.21 and 38.52 ± 6.54, respectively). However, effect of wTTL was not significant. In case of section-wise TTL supplements, TR section significantly (p < .01) improved cleavage and morula rate (58.43 ± 7.98 and 36.14 ± 6.89, respectively) followed by TA. In conclusion, present study indicates that IVM, in vitro fertilization and in vitro culture of embryo are improved in the presence of TTL, particularly its TR section. Further study is expected to reveal the principal components of TTL which may prove useful for IVM.

Isolation, culture optimization and physico-chemical characterization of laccase enzyme from Pleurotus fossulatus

Pleurotus fossulatus (Cooke) Sace is member of oyster mushroom can produced extracellular laccase (benzenediol: oxygen oxidoreductase; EC 1.10.3.2) in submerged fermentation. To analyze the optimum production for laccase P. fossulatus was cultured both in stationary and shaking condition in different media. Partial purification of laccase was done after 0-80% ammonium sulphate precipitation, followed by DEAE (Diethylaminoethyl) Sephadex (A-50) anion exchange chromatography. Potato-sucrose peptone (PSP) medium and Potato-dextrose (PD) medium showed highest laccase production in shaking and stationary conditions, respectively. Though the time required for optimum laccase production in stationary condition was much more than the shaking condition but the amount of laccase was about 2.75t greater in former condition. The laccase produced in stationary condition was more stable than the enzyme produced in shaking condition. The partially purified enzyme showed highest affinity towards o-dianisidine than guaiacol and ABTS (2,2'-Azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) as evidenced by their K(m). The physico-chemical properties of the laccase suggested the significance of this enzyme in industrial applications.

Role of α-crystallin B as a regulatory switch in modulating cardiomyocyte apoptosis by mitochondria or endoplasmic reticulum during cardiac hypertrophy and myocardial infarction

Cardiac hypertrophy and myocardial infarction (MI) are two major causes of heart failure with different etiologies. However, the molecular mechanisms associated with these two diseases are not yet fully understood. So, this study was designed to decipher the process of cardiomyocyte apoptosis during cardiac hypertrophy and MI in vivo. Our study revealed that mitochondrial outer membrane channel protein voltage-dependent anion channel-1 (VDAC1) was upregulated exclusively during cardiac hypertrophy, whereas 78 kDa glucose-regulated protein (GRP78) was exclusively upregulated during MI, which is an important upstream regulator of the endoplasmic reticulum (ER) stress pathway. Further downstream analysis revealed that mitochondrial pathway of apoptosis is instrumental in case of hypertrophy, whereas ER stress-induced apoptosis is predominant during MI, which was confirmed by treatment with either siRNA against VDAC1 or ER stress inhibitor tauroursodeoxycholic acid (TUDCA). Very interestingly, our data also showed that the expression and interaction of small heat-shock protein α-crystallin B (CRYAB) with VDAC1 was much more pronounced during MI compared with either hypertrophy or control. The study demonstrated for the first time that two different organelles—mitochondria and ER have predominant roles in mediating cardiomyocyte death signaling during hypertrophy and MI, respectively, and activation of CRYAB acts as a molecular switch in bypassing mitochondrial pathway of apoptosis during MI.

Sarcoptic mange infestation in pigs in a hilly region of Meghalaya

Skin lesions were collected from 15 adult crossbred pigs maintained at the pig farm of ICAR Research Complex for the North-Eastern Hill Region, Umiam, a hilly region of the state of Meghalaya, India. Skin scrapings of these 15 animals were examined by KOH digestion method. Presence of mites were detected in five animals which were indistinguishable from Sarcoptes scabiei var. suis. Infected pigs were treated with a single dose of Ivermectin at 200 ug/kg body weight, subcutaneously. No mites were recovered from treated pigs after a period of 10 days of post-treatment. The presence of S. scabiei var. suis in pigs from this part of the country has never been reported. This infestation has great significance because it affects the growth rate and feed conversion significantly, specially to the grower and weaned pigs. It can be concluded that S. scabiei var. suis infestation is prevalent in hilly region of Meghalaya. The pig producers are generally unaware about the severity of the problem of mite infestation, so precaution should be taken to prevent their valuable pigs from S. scabiei var. suis infestation.