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B Jiang

Publications and source records attributed to B Jiang.

At least 37 records · Page 2Linked to original sources
PubMed2003

Hydrogen peroxide-induced apoptosis in pc12 cells and the protective effect of puerarin.

In this study, the effect of puerarin on hydrogen peroxide-induced apoptosis in PC12 cells was studied. Exposure of cells to 0.5mM H(2)O(2)may cause significant viability loss and apoptotic rate increase. When c-Myc, Bcl-2 and Bax expression and caspase-3 activity were measured, using Ac-DEVD-AMC as a substrate, the changes in these apoptosis regulatory and effector proteins suggested that the elevation of c-Myc, decrease in Bcl-2:Bax protein ratio, and caspase-3 activation all play a key role in apoptosis. When cells were treated with puerarin prior to 0.5 mM H(2)O(2)treatment, a reduction in viability loss and apoptotic rate was seen. In addition, c-Myc expression decreased and Bcl-2:Bax ratio increased. Puerarin also reduced the H(2)O(2)-induced elevation of caspase-3 activation. These results suggest that puerarin can protect neurons against oxidative stress. It can block apoptosis in its early stages via the regulation of anti- and pro-apoptotic proteins, as well as by the attenuation of caspase-3 activation in H(2)O(2)-induced PC12 cells.

Animals↗
PubMed2003

Cytokines as mediators for or effectors against rotavirus disease in children.

Rotavirus is the most common cause of severe gastroenteritis in young children, but the pathogenesis and immunity of this disease are not completely understood. To examine the host response to acute infection, we collected paired serum specimens from 30 children with rotavirus diarrhea and measured the levels of nine cytokines (interleukin-1beta [IL-1beta], IL-2, IL-4, IL-6, IL-8, IL-10, IL-12, gamma interferon [IFN-gamma], and tumor necrosis factor alpha [TNF-alpha]) using a microsphere-based Luminex Flowmetrix system. Patients with acute rotavirus infection had elevated median levels of seven cytokines in serum, and of these, the levels of three (IL-6, IL-10, and IFN-gamma) were significantly (P < 0.05) higher than those in serum from control children without diarrhea. Patients with fever had significantly (P < 0.05) higher levels of IL-6 in serum than control children, and those with fever and more episodes of diarrhea had significantly (P < 0.05) higher levels of TNF-alpha than those without fever and with fewer episodes of diarrhea. We further demonstrated a negative association (P < 0.05) between the levels of IL-2 and the number of stools on the day on which the first blood sample was collected. Finally, patients with vomiting had significantly (P < 0.05) lower levels of IFN-gamma than those without vomiting. Our pilot study provides evidence that the types and magnitudes of cytokine responses to rotavirus infection in children influence or reflect the clinical outcome of disease. These findings suggest that certain cytokines may play an important role in the pathogenesis of and the protection against rotavirus disease in children and, consequently, may provide directions and insights that could prove critical to the prevention or treatment of this important disease.

Case-Control Studies↗
PubMed2003

A comparison of initial treatment with losartan/HCTZ versus losartan monotherapy in chinese patients with mild to moderate essential hypertension.

The antihypertensive efficacy and tolerability of losartan/hydrochlorothiazide (HCTZ) and losartan monotherapy as initial treatment were compared in a double-blind trial in Chinese patients with mild to moderate essential hypertension. Patients were randomised to initial treatment with either losartan/HCTZ (50 mg/12.5 mg) or losartan alone (50 mg). The doses were doubled after four weeks if diastolic blood pressure (SiDBP)was >90 mmHg. Both losartan/HCTZ and losartan alone significantly reduced SiDBP and SiSBP from baseline at the first measurement at 4 weeks (-10.1/-15.3 and -6.1/-6.9 mmHg, respectively; p<0.001) and at 8 weeks (-13.1/-18.5 and -8.7/-10.9 mmHg; p<0.001). The reductions with losartan/HCTZ were significantly greater than with losartan alone at weeks 4 and 8 (p<0.001). Both regimens were similarly well tolerated. In conclusion, initial therapy with losartan/HCTZ is effective and well tolerated in the treatment of Chinese patients with mild to moderate essential hypertension and produces a greater reduction in blood pressure than losartan alone.

Adolescent↗
PubMed2002

Comprehensive essential gene identification as a platform for novel anti-infective drug discovery.

In large part, antimicrobial drug discovery is driven by the breadth and quality of both potential drug targets and available chemical libraries to screen. Traditionally, targets have been few in number and have been limited to those with known function, from which biochemical assays could be implemented into drug screens. Iterations of this same basic approach, applied to a few biochemically-defined targets have identified a limited set of novel antibiotics and even fewer antifungal agents. Indeed, in the last 50 years less than 30 antimicrobial targets have been exploited commercially. Within infectious disease, the industry was driven largely by chemistry-based approaches, simply making new analogs to existing drugs to overcome the growing problem of drug resistance. Elitra Pharmaceutical s approach has been to enable true functional genomics on a genome-wide scale. Elitra s vision has been to identify all of the essential genes directly in the key pathogenic organisms. Having moved rapidly towards the completion of this goal, we are now faced with the enviable challenge of prioritizing enormous target sets and developing novel sensitive screens for those best suited as definitive drug targets. These highly sensitive, cell-based screening paradigms enable re-screening of even well screened chemical libraries to reveal new chemical entities displaying novel modes of action against new targets. In parallel, we have also begun to shift the paradigm from screening targets singly, towards genome-wide approaches to drug screening.

Anti-Infective Agents↗
PubMed2002

Start-up of a thermophilic methanol-fed UASB reactor: change in sludge characteristics.

Experiments were performed to study the change in sludge characteristics and sludge granulation during the start-up of a thermophilic methanol-fed upflow anaerobic sludge bed (UASB) reactor. The laboratory scale reactor, was inoculated with thermophilic granular sludge and operated at 55 degrees C over 130 days at organic loading rates (OLR) varying from 2.7 to 47 gCOD.L(-1).d(-1). Physical characterisation was performed for both the seed and the cultivated sludge. Results demonstrated that a good quality, well settleable granular sludge was cultivated and retained in the reactor, allowing an OLR of 47 gCOD.L.d(-1) with 93% of methanol removal, where 79% was converted into methane. Using a community analysis of the cultivated consortia, high numbers of rod-shaped hydrogenotrophic methanogens were enumerated. Biomass washout coincided with a high specific gas load, but was not detrimental to the system in the conditions tested.

Bacteria, Anaerobic↗
PubMed2001

Orbital ordering in LaMnO3: estimates of structure factors and comparison of measurement methods.

This paper shows that the phenomenon of orbital ordering should be detectable by energy-filtered quantitative convergent-beam electron diffraction (QCBED). The structure factors of LaMnO(3) crystals are calculated using a non-spherical atomic scattering model of the Mn(3+) ion. Several low-order electron structure factors showed pronounced change with orbital ordering, in which the e(g)(1) electron orders in the 3d(3z(2) - r(2)) orbital leaving the 3d(x(2) - y(2)) unoccupied. In contrast, the X-ray structure factors showed very small change. Orbital order is important in transition-metal oxides, including colossal magnetoresistive manganite oxides. The calculations show that by using QCBED it is possible to measure the subtle changes in electron structure factors due to orbital ordering of the e(g)(1) electron of the Mn(3+) ion in an LaMnO(3) crystal. A comparison of methods for structure-factor measurement is given, including Bragg X-ray and gamma-ray diffraction, X-ray Pendellösung and critical-voltage methods. New measurements by QCBED of structure factors in rutile are compared with the Bragg X-ray values. These show that QCEBD can provide an accurate extinction-free measurement of low-order structure factors, which is extremely difficult or perhaps impossible when using other methods applied to real crystals.

Journal Article↗
PubMed2001

Identification of a Candida albicans ferrichrome transporter and its characterization by expression in Saccharomyces cerevisiae.

Saccharomyces cerevisiae can accumulate iron through the uptake of siderophore-iron. Siderophore-iron uptake can occur through the reduction of the complex and the subsequent uptake of iron by the high affinity iron transporter Fet3p/Ftr1p. Alternatively, specific siderophore transporters can take up the siderophore-iron complex. The pathogenic fungus Candida albicans can also take up siderophore-iron. Here we identify a C. albicans siderophore transporter, CaArn1p, and characterize its activity. CaARN1 is transcriptionally regulated in response to iron. Through expression studies in S. cerevisiae strains lacking endogenous siderophore transporters, we demonstrate that CaArn1p specifically mediates the uptake of ferrichrome-iron. Iron-ferrichrome and gallium-ferrichrome, but not desferri-ferrichrome, could competitively inhibit the uptake of iron from ferrichrome. Uptake of siderophore-iron resulting from expression of CaARN1 under the control of the MET25-promoter in S. cerevisiae was independent of the iron status of the cells and of Aft1p, the iron-sensing transcription factor. These studies demonstrate that the expression of CaArn1p is both necessary and sufficient for the nonreductive uptake of ferrichrome-iron and suggests that the transporter may be the only required component of the siderophore uptake system that is regulated by iron and Aft1p.

Amino Acid Sequence↗
PubMed2001

[Alterations of glial fibrillary acidic protein in rat brain after gamma knife irradiation].

OBJECTIVE: To study glial fibrillary acidic protein (GFAP) immunoreactivity in different time and water content of the rat brain treated with gamma knife radiotherapy and to understand the alteration course of the brain lesion after a single high dose radiosurgical treatment. METHODS: In the brains of the normal rats were irradiated by gamma knife with 160 Gy-high dose. The irradiated rats were then killed on the 1st day, 7th day, 14th day, and 28th day after radiotherapy, respectively. The positive cells of GFAP in brain tissue were detected by immunostaining; the water content of the brain tissue was measured by microgravimetry. The histological study of the irradiated brain tissue was performed with H.E. and examined under light microscope. RESULTS: The numbers of GFAP-positive astrocytes began to increase on the 1st day after gamma knife irradiation. It was enlarged markedly in the number and size of GFAP-stained astrocytes over the irradiated areas. Up to the 28th day, circumscribed necrosis foci (4 mm in diameter) was seen in the central area of the target. In the brain tissue around the necrosis, GFAP-positive astrocytes significantly increased (P < 0.01, compared with the control group). The swelling of cells in irradiated region was observed on the 1st day; after irradiation endothelial cells degenerated and red blood cells escaped from blood vessel on the 7th day; leakage of Evans blue dye was observed in the target region on the 14th day. There was a significant decrease of specific gravity in the irradiated brain tissue the 14th and 28th day after irradiation. CONCLUSION: The results suggest that GFAP can be used as a marker for the radiation-induced brain injury. The brain edema and disruption of brain-blood barrier can be occurred during the acute stage after irradiation.

Animals↗
PubMed2001

Mechanism for muscarinic inhibition of I(Ca(L)) is determined by the path for elevating cyclic AMP in cardiac myocytes.

OBJECTIVE: Does carbachol (CCh) require NO/cGMP for inhibition of L-type calcium current (I(Ca(L))) when either adenylyl cyclase activation or phosphodiesterase suppression is used to raise cAMP? METHODS: The effects of the NO donor SIN-1 (3-morpholino-sydnonimine), CCh and atrial natriuretic peptide (ANP) were evaluated when I(Ca(L)) had been stimulated by isoproterenol (ISO) or 3-isobutyl-1-methylxanthine (IBMX) in guinea pig isolated ventricular myocytes (35 degrees C). RESULTS: Carbachol, SIN-1 or ANP did not affect basal I(Ca(L)); each inhibited IBMX-stimulated I(Ca(L)). Dialyzed (30-100 microM) ODQ (1H-(1,2,4)oxadiazolo(4,3-a)quinoxalin-1-one), a soluble guanylyl cyclase (sGC) inactivator, blocked inhibition of IBMX-stimulated I(Ca(L)) by SIN-1 (10 microM) but not by CCh (1-100 microM) or ANP (100 nM). Dialysis with 3 microM LY83583 (6-anilino-5,8-quinolinedione), a particulate (pGC) and sGC inactivator, opposed muscarinic-, ANP- and SIN-1-induced inhibition of IBMX-stimulated I(Ca(L)). Thus CCh can increase cGMP synthesis via pGC. Even with 100 microM [LY83583](pip), CCh inhibited ISO-stimulated I(Ca(L)), an effect referable to suppression of adenylyl cyclase activity. However, 3 microM [LY83583](pip) prevented inhibition of ISO-stimulated I(Ca(L)) by ANP. [LY83583](pip) did not affect inhibition by 8 bromo-cGMP (100 microM) of ISO- or IBMX-stimulated I(Ca(L)). The observations indicate that: (1) myocytes have ODQ-sensitive sGC activated by NO and LY8353-sensitive pGC activated by ANP, (2) CCh does not inhibit I(Ca(L)) via NO, (3) the mechanism for muscarinic inhibition depends upon the cAMP-elevating agent and (4) LY83583 distinguishes between two pathways for muscarinic inhibition. CONCLUSION: The nature of the stimulant pathway that increases cAMP determines intracellular transduction of muscarinic inhibition. This hypothesis accords with distinct cyclic nucleotide compartments for the differential expression of muscarinic inhibition of I(Ca(L)).

1-Methyl-3-isobutylxanthine↗
PubMed2001

Enantioselective synthesis for the (-)-antipode of the pyrazinone marine alkaloid, hamacanthin A.

A short enantioselective total synthesis for the (-)-antipode of the antifungal marine alkaloid, hamacanthin A, (6R)-3,6-bis(6-bromoindol-3-yl)-5,6-dihydro-2(1H)-pyrazinone, is described. This synthesis proceeds through the coupling of 3-indolyl-alpha-oxoacetyl chloride and 3-indolyl azidoethylamine, followed by intramolecular aza-Wittig type cyclization. A concise and useful approach for the synthesis of (1R)-1-(indol-3-yl)-2-azidoethylamine using the Sharpless asymmetric dihydroxylation reaction followed by stereospecific azidation is also presented.

Alkaloids↗
PubMed2001

Synthesis and antitumor evaluation of novel monoindolyl-4-trifluoromethylpyridines and bisindolyl-4-trifluoromethylpyridines.

A series of novel monoindolyl-4-trifluoromethylpyridines and bisindolyl-4-trifluoromethylpyridines was designed and synthesized as potential antitumor agents. They were evaluated for preliminary cytotoxic activity against P388 and A-549 cells with IC50 values. 4-Trifluoromethyl-2,6-bis[3'-(N-tosyl-6'-methoxyl-indolyl)] pyridine was identified as the most potent in this series.

Animals↗
PubMed2001

Gastroenteritis viruses: an overview.

Acute gastroenteritis is among the most common illnesses of humankind, and its associated morbidity and mortality are greatest among those at the extremes of age, children and the elderly. In developing countries, gastroenteritis is a common cause of death in children < 5 years that can be linked to a wide variety of pathogens. In developed countries, while deaths from diarrhoea are less common, much illness leads to hospitalization or doctor visits. Much of the gastroenteritis in children is caused by viruses belonging to four distinct families--rotaviruses, caliciviruses, astroviruses and adenoviruses. Other viruses, such as the toroviruses, picobirnaviruses, picornavirus (the Aichi virus), and enterovirus 22, may play a role as well. Viral gastroenteritis occurs with two epidemiologic patterns, diarrhoea that is endemic in children and outbreaks that affect people of all ages. Viral diarrhoea in children is caused by group A rotaviruses, enteric adenoviruses, astroviruses and the caliciviruses; the illness affects all children worldwide in the first few years of life regardless of their level of hygiene, quality of water, food or sanitation, or type of behaviour. For all but perhaps the caliciviruses, these infections provide immunity from severe disease upon reinfection. Epidemic viral diarrhoea is caused primarily by the Norwalk-like virus genus of the caliciviruses. These viruses affect people of all ages, are often transmitted by faecally contaminated food or water, and are therefore subject to control by public health measures. The tremendous antigenic diversity of caliciviruses and short-lived immunity to infection permit repeated episodes throughout life. In the past decade, the molecular characterization of many of these gastroenteritis viruses has led to advances both in our understanding of the pathogens themselves and in development of a new generation of diagnostics. Application of these more sensitive methods to detect and characterize individual agents is just beginning, but has already opened up new avenues to reassess their disease burden, examine their molecular epidemiology, and consider new directions for their prevention and control through vaccination, improvements in food and water quality and sanitary practices.

Adenoviruses, Human↗
PubMed2001

Cytotoxic 7,20-epoxy ent-kauranoids from Isodon xerophilus.

Four 7,20-epoxy ent-kaurane diterpenoids, xerophilusins G (1) and I-K (2-4), were isolated from the leaves of Isodon xerophilus, along with four known ones, enanderianin C (5), rosthorin A (6), longikaurin B (7), and rabdoternin D (8). Their structures were determined primarily using NMR spectroscopic techniques. The structure and stereochemistry of 3 were confirmed by X-ray crystallography. Compounds 4 and 7 exhibited broad cytotoxicity against four kinds of human tumor cells (K562, HL-60, HCT, and MKN-28 cells) in the range of 2.23-15.35 and 0.30-8.61 microg/ml, respectively.

Antineoplastic Agents, Phytogenic↗
PubMed2001

Synthesis and cytotoxicity evaluation of novel indolylpyrimidines and indolylpyrazines as potential antitumor agents.

Novel indolylpyrimidines and indolylpyrazines have been synthesized as potential antitumor agents. They were screened in a panel of 60 human tumor cell lines in vitro. Compounds 7, 9, 10, 15, 21 exhibited efficiently cytotoxic activities with GI(50) values in the low micromolar range against a variety of human cancer cell lines. 2,4-Bis(3'-indolyl)pyrimidine 8 displayed selective cytotoxic activity against IGROV1 tumor cell line with the GI(50) value below 0.01 microM.

Antineoplastic Agents↗
PubMed2001

Synthesis of novel analogues of marine indole alkaloids: mono(indolyl)-4-trifluoromethylpyridines and bis(indolyl)-4-trifluoromethylpyridines as potential anticancer agents.

Mono(indolyl)-4-trifluoromethylpyridines and bis(indolyl)-4-trifluoromethylpyridines were synthesized using Suzuki cross-coupling reaction between 2-chloro-4-trifluoromethylpyridine 9, 2,6-dichloro-4-trifluoromethylpyridine 6 or 2,6-dichloro-3-cyano-4-trifluoromethylpyridine 23 and N-tosyl-3-indolylboronic acid 10. They were evaluated for cytotoxic activity against P388 and A-549 cells with IC(50) values. 4-Trifluoromethyl-2,6-bis[3'-(N-tosyl-6'-methoxylindolyl)]pyridine 18 was identified as the most potent in this series.

Alkaloids↗