Degradation of aromatic compounds and degradative pathway of 4-nitrocatechol by Ochrobactrum sp. B2

The potential capacity of a soil methyl parathion-degrading bacterium strain, Ochrobactrum sp. B2, for degrading various aromatic compounds were investigated. The results showed B2 was capable of degrading diverse aromatic compounds, but amino-substituted benzene compounds, at a concentration up to 100 mg L(-1) in 4 days. B2 could use 4-nitrocatechol (4-NC) as a sole carbon and energy source with release of nitrite ion. The pathway for 4-NC degradation via 1,2,4-benzenetriol (BT) and hydroquinone (HQ) formation in B2 was proposed based on the identification and quantification of intermediates by gas chromatography-mass spectrometry (GC-MS), and high performance liquid chromatography (HPLC). Degradation studies carried out on a plasmid-cured derivative showed that the genes for 4-NC degradative pathway was plasmid-borne in B2, suggesting that B2 degrades both p-nitrophenol and 4-NC by enzymes encoded by genes on the same plasmid.

Antiviral activity of arbidol against influenza A virus, respiratory syncytial virus, rhinovirus, coxsackie virus and adenovirus in vitro and in vivo

Arbidol, ethyl-6-bromo-4-[(dimethylamino)-methyl]-5-hydroxy-1-methyl-2-[(phenylthio)methyl]-in dole-3-carboxylate hydrochloride monohydrate, is an antiviral chemical agent. In this report, we studied the antiviral activity of arbidol against a panel of human respiratory viruses, namely influenza A virus (FLU-A, A/PR/8/34 H1N1), respiratory syncytial virus (RSV), human rhinovirus type 14 (HRV 14), coxsackie virus B3 (CVB3) and adenovirus type 7 (AdV-7) in vitro in cell culture. Arbidol was found to present potent inhibitory activity against enveloped and non-enveloped RNA viruses, including FLU-A, RSV, HRV 14 and CVB3 when added before, during, or after viral infection, with 50% inhibitory concentration (IC50) ranging from 2.7 to 13.8 microg/ml. However, arbidol showed selective antiviral activity against AdV-7, a DNA virus, only when added after infection (therapeutic index (TI) = 5.5). Orally administered arbidol at 50 or 100 mg/kg/day beginning 24 h pre-virus exposure for 6 days significantly reduced mean pulmonary virus yields and the rate of mortality in mice infected with FLU-A (A/PR/8/34 H1N1). Our results suggest that arbidol has the ability to elicit protective broad-spectrum antiviral activity against a number of human pathogenic respiratory viruses.

Vibrational and rotational dynamics of cyanoferrates in solution

Ultrafast infrared spectroscopy has been used to measure vibrational energy relaxation (VER) and reorientation (Tr) times for the high frequency vibrational bands of potassium ferrocyanide and ferricyanide (CN stretches), and sodium nitroprusside (SNP, CN, and NO stretches) in water and several other solvents. Relatively short VER times (4-43 ps) are determined for the hexacyano species and for the NO band of SNP, but the CN band of SNP relaxes much more slowly (55-365 ps). The solvent dependence of the VER times is similar for all the solutes and resembles what has been previously observed for triatomic molecular ions [Li et al., J. Chem. Phys. 98, 5499 (1993)]. Anisotropy decay times are also measured from the polarization dependence of the transient absorptions. The Tr times determined for SNP are different for the different vibrational bands; for the nondegenerate NO mode of nitroprusside (SNP) they are much longer (>15 ps), correlate with solvent viscosity, and are attributed to overall molecular rotation. The short Tr (<10 ps) times for the CN band in SNP and for the hexacyanoferrates are due to dipole orientational relaxation in which the transition moment rapidly redistributes among the degenerate modes. There is no evidence of intramolecular vibrational relaxation (IVR) to other high frequency modes. VER times measured for hexacarbonyls and SNP in methanol are similar, which suggests that the generally faster VER for the latter is in part because they are soluble in more strongly interacting polar solvents. The results are compared to those for small ions and metal carbonyls and are discussed in terms of the importance of solute charge and symmetry on VER.

Differential responses of antioxidative system to chilling and drought in four rice cultivars differing in sensitivity

Responses of antioxidative defense systems to chilling and drought stresses were comparatively studied in four cultivars of rice (Oryza sativa L.) differing in sensitivity, two of them (Xiangnuo no. 1 and Zimanuo) are tolerant to chilling but sensitive to drought and the other two (Xiangzhongxian no. 2 and IR50) are tolerant to drought but sensitive to chilling. The seedlings of rice were transferred into growth chamber for 5 d at 8 degrees C as chilling treatment, or at 28 degrees C as control, or at 28 degrees C but cultured in 23% PEG-6000 solution as drought stress treatment. Under drought stress the elevated levels of electrolyte leakage, contents of H(2)O(2) and total thiobarbituric acid-reacting substances (TBARS) in Xiangzhongxian no. 2 and IR50 are lower than those in Xiangnuo no. 1 and Zimanuo. On the contrary, Xiangnuo no. 1 and Zimanuo have much lower level of electrolyte leakage, H(2)O(2) and TBARS than Xiangzhongxian no. 2 and IR50 under chilling stress. Activities of antioxidant enzymes (superoxide dismutase (SOD), catalase, and ascorbate-peroxidase (APX)) and contents of antioxidants (ascorbaic acid and reduced glutathione) were measured during the stress treatments. All of them were enhanced greatly until 3 d after drought stress in the two drought-tolerant cultivars, or after chilling stress in the two chilling-tolerant cultivars. They all were decreased at 5 d after stress treatments. On the other hand, activities of antioxidant enzymes and contents of antioxidants were decreased greatly in the drought-sensitive cultivars after drought stress, or in the chilling-sensitive cultivars after chilling stress. The results indicated that tolerance to drought or chilling in rice is well associated with the enhanced capacity of antioxidative system under drought or chilling condition, and that the sensitivity of rice to drought or chilling is linear correlated to the decreased capacity of antioxidative system.

Retrovirus molecular conjugates: a versatile and efficient gene transfer vector system for primitive human hematopoietic progenitor cells

In principle, transient nongenetic modification of a noninfectious gene transfer virus enabling a one time infection and transduction of human cells could eliminate the risk of formation of replication competent virus. Formation of a molecular conjugate vector by conjugation of noninfective ecotropic murine Moloney leukemia virus to polylysine (eMMLV-PL) enabled high-efficiency transduction of human HPC using in vitro and in vivo assays. Xenotransplanted NOD-SCID mice durably expressed the transgene in human leukocytes and human progenitor cells with eMMLV-PL achieving three-fold increased transduction efficiency when directly compared to optimized amphotropic MMLV (aMMLV) transduction. Both aMMLV and eMMLV assembled conjugate vectors showed similar transduction efficiency indicating predominant polylysine-mediated uptake. Integration of retroviral sequences was determined from individual human HPC recovered from eMMLV-PL-xenotransplanted animals. This simple and versatile concept of conjugate gene transfer vectors has the potential to enhance transduction efficiency as well as to improve certain safety aspects of human gene therapy. Moreover, because it permits effective cellular internalization of particles, this concept of molecular conjugates can be used as research tool to investigate the interactions of otherwise noninfectious viruses or modified viral particles at the genomic level.

Deficiency in mitochondrial anionic phospholipid synthesis impairs cell wall biogenesis

Cardiolipin (CL) is the signature lipid of the mitochondrial membrane and plays a key role in mitochondrial physiology and cell viability. The importance of CL is underscored by the finding that the severe genetic disorder Barth syndrome results from defective CL composition and acylation. Disruption of PGS1, which encodes the enzyme that catalyses the committed step of CL synthesis, results in loss of the mitochondrial anionic phospholipids phosphatidylglycerol and CL. The pgs1Delta mutant exhibits severe growth defects at 37 degrees C. To understand the essential functions of mitochondrial anionic lipids at elevated temperatures, we isolated suppressors of pgs1Delta that grew at 37 degrees C. The present review summarizes our analysis of suppression of pgs1Delta growth defects by a mutant that has a loss-of-function mutation in KRE5, a gene involved in cell wall biogenesis.

Changes in mitotic rate and GFAP expression in the primary olfactory axis of streptozotocin-induced diabetic rats

Many diabetic individuals develop anosmia but the mechanism(s) causing the dysfunction in the olfactory system is (are) unknown. Glial fibrillary acidic protein expression is reduced in diabetic retinopathy and is also reduced, with unknown consequences, in other brain regions of diabetic rats. We used immunohistochemistry and immunoblotting from untreated control and streptozotocin-induced type 1 (insulin dependent) diabetic rats to investigate main olfactory epithelial mitotic rate and glial fibrillary acidic protein expression in the lamina propria of the sensory epithelium and in the olfactory bulb. Numbers of bromodeoxyuridine-positive cells were significantly lower in the diabetic sensory epithelium compared to non-diabetic controls. Immunohistochemical observations suggested a qualitative difference in glial fibrillary acidic protein expression in both regions examined especially in the olfactory bulb external plexiform layer and the lamina propria. Immunoblot analysis confirmed that the diabetic olfactory bulb and lamina propria expressed less glial fibrillary acidic protein compared to the non-diabetic control group. The lower expression levels in the olfactory bulb external plexiform layer suggested by immunohistochemistry do not reflect a change in the number of astrocytes since the numbers of S100B(+) cells were not different between the two groups.

Transition probabilities in 134Pr: a test for chirality in nuclear systems

Exited states in 134Pr were populated in the fusion-evaporation reaction 119Sn(19F,4n)134Pr. Recoil distance Doppler-shift and Doppler-shift attenuation measurements using the Euroball spectrometer, in conjunction with the inner Bismuth Germanate ball and the Cologne plunger, were performed at beam energies of 87 MeV and 83 MeV, respectively. Reduced transition probabilities in 134Pr are compared to the predictions of the two quasiparticle + triaxial rotor and interacting boson fermion-fermion models. The experimental results do not support the presence of static chirality in 134Pr underlying the importance of shape fluctuations. Only within a dynamical context the presence of intrinsic chirality in 134Pr can be supported.

Kinetics of rennet casein gelation at different cooling rates

A mathematical model was developed to quantitatively analyze the rheological data of rennet casein gelation at different cooling rates. Kinetic parameters were estimated and correlated with the microstructure development of the protein network. The kinetic model identified structure development upon cooling to be first order, and the network forming energies were estimated for four protein concentrations cooled at four rates. A lower energy for network formation was observed for a slower cooling rate and a higher protein concentration. This observation resulted from the availability of more flocs at a slower cooling rate and a higher casein concentration, simplifying floc cross-linking. By analyzing the kinetics during the aging process of casein gels, no difference in the reaction mechanism was observed. This study illustrated that structure formation resulted from the addition of flocs into the protein network: not all flocs were part of the network at a defined gel point. The incubation period following cooling integrated idle flocs into the network, thereby strengthening the gel. By understanding the gelation mechanism during cooling of rennet casein gels, the structure and thus quality of dairy products, such as processed cheese, may be better controlled.

Retrovirus molecular conjugates

Retrovirus-derived vectors are currently the preferred vectors used for human gene therapy protocols. Serious safety concerns persist, however, which are specifically related to the formation of a replication-competent virus, and no synthesis method currently employed precludes its formation with certainty. For many cell types, a low transduction efficiency results in insufficient therapeutic benefit. We describe the development of a molecular conjugate system, which permits transient chemical modification of a retrovirus with polylysine. This modification not only introduces additional safety features over standard unmodified retrovirus vectors, but also provides enhanced transduction efficiency.