The effect of AmtR on growth and amino acids production in Corynebacterium glutamicum

AmtR, the master regulator of nitrogen control in Corynebacterium glutamicum, plays important roles in nitrogen metabolism. To investigate the influence of AmtR on amino acids production in C. glutamicum ATCC 13032, the amtR deletion strain C. glutamicum Q1 was constructed and cultured in modified CGXII minimal medium for 60 h. The ammonium consumption rates as well as amino acids production of both strains cultured in modified CGXII minimal medium were determined. The amtR deletion in C. glutamicum caused an obvious growth defect in the exponential growth phase, but both strains had the same biomass in the stationary phases. Maybe the less alpha-oxoglutarate was used for the tricarboxylic acid cycle to influence the growth of strains. During 12 h, the rate of ammonium consumption and the concentration of Glu, Pro, Arg and Ser were higher but Asp, Gly, Ile, Leu, Lys were lower in the mutation strain. During 48 h, the Q1 had higher levels of Asp, Lys, Pro, Ala and Val,and lower levels of Glu, Arg, Leu and Ile, compared to the wild. The more Glu was synthesized by the activated GS/GOGAT pathway in Q1, and then the accumulation of relative amino acids (Pro, Arg and Ser) were up-regulated within 12 h growth. After 48 h growth, the amtR deletion obviously influenced accumulation of Ala, Asp and Pro. The amtR deletion could influence the growth and amino acids production, which could be useful to the production of amino acids.

Association analysis of TIM-1 -232G > A and 5383_5397 insertion/deletion polymorphisms with childhood asthma and total serum immunoglobulin E levels in middle China

BACKGROUND

One of the members of the T cell immunoglobulin (Ig) domain and mucin domain (TIM) gene family, TIM-1, located in the chromosome 5q31-33 region, has been associated with the development of T helper (T(H)) 2-biased immune responses and may be selectively expressed in T(H)2 cells. Previous studies have also shown an association between polymorphisms in the TIM-1 gene and asthma or asthma-related phenotypes.

OBJECTIVE

The aim of the present study was to analyze the association between the TIM-1 polymorphisms -232G > A and 5383_5397 insertion/deletion (ins/del) and susceptibility to asthma in a group of patients from middle China.

METHODS

Polymerase chain reaction (PCR)-restriction fragment length polymorphism analysis and PCR-polyacrylamide gel electrophoresis were used to detect -232G > A and 5383_5397 ins/del genotypes in 302 asthmatic children and 206 controls. Serum total IgE was measured by chemiluminescence and specific IgE to common aeroallergens by immunoblot analysis.

RESULTS

We found no association between the -232G > A polymorphism and asthma or total serum IgE levels or statistically significant differences between asthma and control subjects in terms of genotype and allele frequency for the 5383_5397 ins/del polymorphism.We did, however, detect a difference in total serum IgE levels for 5383_5397 ins/ins genotypes in individuals with atopic asthma (P < .05) in that they had higher IgE levels than those with del/del and del/ins genotypes.

CONCLUSION

Our results suggest that the 5383_5397 ins/ins genotype in the TIM-1 gene is associated with elevated serum total IgE levels, particularly in individuals with atopic asthma. Further studies are needed to confirm such an association.

Adsorption of Pseudomonas putida on clay minerals and iron oxide

Adsorption of Pseudomonas putida on minerals including montmorillonite, kaolinite and goethite was studied. The adsorption isotherms of P. putida on the examined minerals conformed to the Langmuir equation. The amount of P. putida adsorbed followed the order: goethite > kaolinite > montmorillonite. A greater extent of P. putida adsorption on minerals was observed in the range of temperature from 15 to 35 degrees C. The adsorption of P. putida on minerals decreased with the increase of pH from 3.0 to 10.0. Magnesium ion was more efficient than sodium ion in promoting P. putida adsorption on minerals. The results suggest that electrostatic interactions play a vital role in P. putida adsorption by soil colloidal factions. The information obtained in this study is of fundamental significance for the understanding of the survival and transport of bacteria in soil systems.

Methyl palmitate: inhibitor of phagocytosis in primary rat Kupffer cells

Kupffer cells are involved in phagocytosis and known to release biologically active mediators during early events of liver injury. Such functional properties of Kupffer cells can be modulated by methyl palmitate (MP). Therefore, efficacy of MP to modulate Kupffer cell function was evaluated in cultured primary Kupffer cells from rat liver. Phagocytic activity of Kupffer cells was measured by their capacity to phagocytize latex beads and the release of TNF-alpha, IL-10, IL-6, nitric oxide, and PGE2 was determined in cell culture medium after incubating the cells with various concentrations of MP for 24 h followed stimulation with lipopolysaccharide (LPS) for 6 h. To understand the mechanism of phagocytosis, we investigated the hydrolysis of MP, and determine ATP levels and activity of NF-kappaB in MP-inhibited Kupffer cells. A significant decrease was observed in phagocytosis. Phagocytosis evaluated at 0.5 mM MP was found to be time-dependent with a maximum decrease of 49% at 6 h. Exposure of Kupffer cells to MP followed by LPS stimulation showed a dose-dependent decrease in phagocytosis and reduced the release of TNF-alpha, IL-10, nitric oxide, and PGE2 but not of IL-6 levels in the supernatant as compared to the control. While ATP levels were unchanged, the nuclear factor NF-kappaB (p65) activity was inhibited in Kupffer cells treated with MP after LPS stimulation (35.6 RLU versus 49.6 RLU in control). Hydrolysis of MP was found to be time-dependent; maximum concentration of MP and palmitic acid (hydrolysis products) in the cell being at 3 and 6 h, respectively. In general, MP appears to reduce phagocytosis and levels of TNF-alpha, IL-10, nitric oxide, and PGE2 without affecting ATP levels and is probably mediated by NF-kappaB. This in vitro model is useful for detailed mechanistic studies of inhibition of phagocytosis by MP and other fatty acid esters.

Gamma Knife radiosurgery as a primary surgical treatment for hypersecreting pituitary adenomas

OBJECT

To estimate the efficacy of Gamma Knife radiosurgery (GKR) especially as a primary surgical treatment for hypersecreting pituitary adenomas.

METHODS

274 patients were treated with GKR. The mean tumor volume was 1.86 cm(3). The mean peripheral dose was 28.7 Gy.

RESULTS

223 patients were followed up for an average of 31.6 months. The dose related to the tumor growth control and endocrinological normalization was detailed and statistical analysis of the data was performed.

CONCLUSION

GKR as a primary surgical treatment for hypersecreting pituitary adenomas may be safe and effective.

Spectroscopic and theoretical studies on copper(II) complex of maleinitriledithiolate and 1,10-phenanthroline

A complete vibrational spectra analysis of the title complex is performed in this paper. The molecular geometry, binding, electron structure and spectroscopic properties for the title complex are studied in detail by PM3 or ZINDO/S method. It has been found that this complex has a planar structure belonging to the symmetry point group C2v and its ground state is the spin doublet state. By comparison with the observed results, it can be concluded that PM3 methods are reliable to calculate the vibrational spectra of this molecule. It is worth noting that the scientific method of assigning vibrational spectra for a complicated molecule containing metal is established herein for the first time by giving main fixed points and pivotal vibrational units. Besides the regular symbols, the new defined symbols eta and M play an important role in describing the vibrational modes accurately and vividly.

[The experimental study of intratemporal facial nerve regeneration in chitin chamber]

OBJECTIVE

To investigate the feasibility of intratemporal facial nerve regeneration in a chitin chamber.

METHODS

A left 6 mm intratemporal facial nerve gap was created in adult white rabbit, and a total of 48 animals were used. The proximal and distal stumps were bridged with chitin chamber (experimental group) and silicone chamber (control group). Regeneration of the nerve was assessed by gross observation, nerve electrophysiological test, histological examination and digital morphological analysis in both groups.

RESULTS

1. Three months after implantation, the proximal transected neural stump was connected with the distal stump in the chitin chamber. Five months after operation, the regenerated nerve exhibited a more nature fascicular organization and the chitin tubes were completely absorbed. 2. Nerve evoked potentials showed better conduction ability in the chitin chamber. There were no significant difference in electrophysiological indices between the two chamber groups. 3. Most of the regenerated nerve fibers were myelinated nerve fibers, and axons and myelins had similar histograms between the experimental and control groups. 4. Five months after operation, the mean percentage of recovery of the regenerated nerve fiber area, axonal area and axonal number were more than 71% in the experimental group. There was no significant difference between the control and experimental groups.

CONCLUSION

These results suggested that intratemporal facial nerve could regenerate effectively within the chitin chamber in rabbits and such kind of chamber may be clinically useful.

Kinase-inducible domain-like region of HTLV type 1 tax is important for NF-kappaB activation

Partial proteolysis of HTLV-1 Tax protein has revealed the region surrounding amino acid residues (88)KVL(90) to be highly exposed. The protein sequence surrounding this region ((81)QRTSKTLKVLTPPIT(95)) bears resemblance to the kinase-inducible domain (KID, (129)SRRPSYRKILNE(140)) of CREB and is involved in recruiting transcriptional coactivators, p300 and CBP, for trans-activating the viral long terminal repeat (LTR). Data have also revealed the KID-like region to be important for Tax binding to DNA. Here we report that single (K88A, V89A, L90A) and double alanine substitutions (V89A-L90A) in the (88)KVL(90) motif attenuate the ability of Tax to activate NF-kappaB. Deletions near or spanning this motif also had the same effect. The alanine substitutions affect HTLV-1 LTR activation and NF-kappaB activation differently, with K88A and V89A mutants showing much reduced activities for HTLV LTR activation while retaining attenuated but significant NF-kappaB-activating function. In contrast, although the L90A mutant is similarly attenuated for NF-kappaB activation, it showed significant activity in LTR trans-activation. Incorporation of both V89A and L90A substitutions in a V89A-L90A double mutant further reduced NF-kappaB activation and completely abrogated LTR trans-activation. In aggregate, these results demonstrate the importance of the KID-like domain of Tax and implicate its interaction with cellular factors other than p300/CBP in NF-kappaB activation.

8-methyl-pyridoxatin: A novel N-hydroxy pyridone from fungus OS-F61800 that induces erythropoietin in human cells

In the course of screening for small-molecule modulators of erythropoietin gene expression, a novel N-hydroxy pyridone was isolated from a culture of OS-F61800. Its structure was elucidated by extensive 1H and 13C NMR spectroscopic and chemical studies. This compound induced erythropoietin gene expression fivefold at a concentration of 0.3 microM, which is about threefold greater potency than our previously identified erythropoietin inducers.

Division of C8 nerve root for treatment of spastic cerebral palsy in the upper limbs: a preliminary report

OBJECTIVE

To investigate the effect of C8 nerve root division on the treatment of spastic cerebral palsy in the upper limbs.

METHODS

Two patients were treated with division of the C8 never root. Supraclavicular incision was made to expose the C5-T1 nerve roots. The intraoperative electromyographic recording technique was used to monitor the responses from the flexor digitorum and flexor carpi ulnaris muscle groups simultaneously. The C5-T1 nerve roots were stimulated and the evoked muscle amplitude potentials (EMAP) were recorded from the muscle groups. The EMAP of the muscle groups obtained during electrical stimulation of the C8 nerve root was the largest, which was used as the basis for C8 nerve root division.

RESULTS

Division of the C8 nerve root slightly affected the function of the upper limb, and reduced the muscle tone of the flexor wrist and digitorum.

CONCLUSION

Division of the C8 nerve root can reduce the muscle tone of the flexor wrist and digitorum in a short time. The long-term effects need to be followed up further.

Anodal block in F-wave studies

OBJECTIVE

To determine whether F-wave results differ with the anode proximal or distal to the cathode, ie, if clinical anodal block exists.

DESIGN

Prospective study of 30 healthy volunteers undergoing nerve conduction and F-wave studies in one median nerve. A needle cathode electrode was used with a surface anode placed alternately proximal and distal to the cathode. The same electromyographer performed all studies with a Dantec Counterpoint machine.

RESULTS

F-wave latencies were essentially unaffected by distal versus proximal positioning. Minimum, maximum, and mean F-wave latencies correlated extremely highly (r=.973 to .988). For both F-wave and M-response latencies and amplitudes, differences between mean values obtained using the two methods were extremely small and were neither clinically nor statistically significant. The frequency of elicitation of F-waves may (p < .05) have been slightly (3.5%) lower when the anode was in the distal position.

CONCLUSION

Anodal block is not seen in F-wave studies when using needle electrode stimulations. Reversing the stimulator does not seem to be required. Further study with surface stimulating electrodes is underway to confirm results.

Application of zeeman modulation faraday spectroscopy to the measurement of a magnetic field

We report what is to our knowledge the first possibility of a NO(2) molecular magnetometer based on the Zeeman modulation magnetic rotation spectroscopic (ZM MRS) technique and the magneto-optic activity of NO(2). The linear dependence of the ZM MRS signal intensity on the modulating magnetic field is theoretically analyzed and experimentally measured. The design concept of the magnetometer and its main features are discussed.

Epolones: novel sesquiterpene-tropolones from fungus OS-F69284 that induce erythropoietin in human cells

In the course of our screening for small molecule modulators of erythropoietin gene expression, two novel sesquiterpene tropolones and pycnidone were isolated from a culture of OS-F69284 (ATCC 74390). Their structures were elucidated by extensive 1H and 13C NMR spectroscopic studies and chemical reactions. These compounds induced erythropoietin gene expression 5-fold at a concentration of 1-1.6 microM.

Isolation and characterization of the fungal metabolite 3-O-methylviridicatin as an inhibitor of tumour necrosis factor alpha-induced human immunodeficiency virus replication

The cytokine tumour necrosis factor alpha (TNF-alpha) has been shown to play a role in human immunodeficiency virus (HIV) replication by activating transcription of the provirus in both T cells and macrophages. Therefore, agents that block TNF-alpha-induced HIV expression could have therapeutic value in the treatment of AIDS. We have sought to identify antiviral agents that block TNF-alpha induction of HIV LTR-directed transcription, using a cell-based, virus-free assay system in automated high-throughput screening. HeLa cells were transfected with an HIV LTR-luciferase reporter plasmid and a stable line was isolated in which TNF-alpha increased luciferase production by two- to threefold. This cell line was used to screen approximately 15,000 fungal extracts. An inhibitory activity specific for TNF-alpha-induced HIV LTR transcription was observed in culture OS-F67406. The active component was isolated and identified as a known metabolite, 3-O-methylviridicatin, by NMR and mass spectrometry. No biological activity has been associated with this compound previously. This compound blocks TNF-alpha activation of the HIV LTR in the HeLa-based system, with an IC50 of 5 microM, and inhibited virus production in the OM-10.1 cell line, a model of chronic infection responsive to induction by TNF-alpha, with an IC50 of 2.5 microM.

Destruxin-A4 chlorohydrin, a novel destruxin from fungus OS-F68576: isolation, structure determination, and biological activity as an inducer of erythropoietin

In the course of screening for small-molecule modulators of erythropoietin gene expression, five destruxins were isolated from the fungal culture of OS-F68576. The structures were elucidated by extensive 1H and 13C NMR spectroscopy and by hydrolytic modification. One compound (destruxin-A4 chlorohydrin, 1) is a novel destruxin. All these compounds induced erythropoietin gene expression 5-fold at concentration of 0.2-2 microM.

[Determination of ampelopsin and myricetin in Ampelopsis cantoniensis]

Ampelopsis cantoniensis (Hook. et Arn.) Planch. is a Chinese herbal medicine rich in flavonoids. A method to determine flavonoids in the herbal was studied. After the herbal was extracted in hot water, Ampelopsin and myricetin in the extract were separated by polyamide column with eluent of ethanol-water and measured by spectrophotometry. As results, 100 g of the dry herbal contains 25.2 g of ampelopsin (RSD = 1.7%, recovery = 97.0%) and 1.77 g of myricetin (RSD = 3.3%, recovery = 103%).