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Biomedical subjects

Bo Zhang

Publications and source records attributed to Bo Zhang.

At least 55 records · Page 3Linked to original sources
PubMed2006

Effects of atorvastatin and apoA-I/phosphatidylcholine discs on triglyceride-rich lipoprotein subfractions as characterized by capillary isotachophoresis.

BACKGROUND: The present study examined the effects of atorvastatin and the in vitro effect of apolipoprotein (apo) A-I/phosphatidylcholine (POPC) discs on charge-based triglyceride-rich lipoprotein (TRL) subfractions in a patient with type III hyperlipoproteinemia (HLP) and the apoE2/2 phenotype. METHODS: Charge-based lipoprotein subfractions were characterized by capillary isotachophoresis (cITP). cITP analysis was performed using plasma that had been prestained with a lipophilic dye on a Beckman P/ACE MDQ system. RESULTS: Treatment with atorvastatin for 4 weeks markedly decreased the slow (s)-migrating TRL subfraction and both fast- and slow-migrating low-density lipoprotein (LDL) subfractions, but did not affect the fast (f)-migrating TRL subfraction in this patient. ApoA-I/POPC discs consisted of two major charge-based subfractions that had the mobility of cITP fTRL and sTRL. Incubation of plasma from this patient in the presence of apoA-I/POPC discs caused not only a reduction in cITP fast- and intermediate-migrating HDL and an increase in cITP sHDL but also a reduction in fTRL and sTRL and an increase in sLDL. CONCLUSION: Atorvastatin and apoA-I/POPC discs decreased cITP TRL subfractions in a complementary manner, suggesting that the combination of apoA-I/POPC discs and atorvastatin could be a promising therapeutic approach for hypertriglyceridemia.

Adult↗
PubMed2006

Electron exchange between Fe(II)-horse spleen ferritin and Co(III)/Mn(III) reconstituted horse spleen and Azotobacter vinelandii ferritins.

Azotobacter vinelandii bacterioferritin (AvBF) containing 800-1500 Co or Mn atoms as Co(III) and Mn(III) oxyhydroxide cores (Co-AvBF, Mn-AvBF) was synthesized by the same procedure used previously for horse spleen ferritin (HoSF). The kinetics of reduction of Co-AvBF and Mn-AvBF by ascorbic acid are first-order in each reactant. The rate constant for the reduction of Mn-AvBF (8.52 M(-1) min(-1)) is approximately 12 times larger than that for Co-AvBF (0.72 M(-1) min(-1)), which is consistent with a previous observation that Mn-HoSF is reduced approximately 10-fold faster than Co-HoSF [Zhang, B. et al. (2005) Inorg. Chem. 44, 3738-3745]. The rates of reduction of M-AvBF (M = Co and Mn) are more than twice that for the reduction of the corresponding M-HoSF. HoSF containing reduced Fe(II) cores (Fe(II)-HoSF), prepared by methyl viologen and CO, also reduces M-HoSF and M-AvBF species, with both cores remaining within ferritin, suggesting that electrons transfer through the ferritin shell. Electron transfer from Fe(II)-HoSF to Co-AvBF occurs at a rate approximately 3 times faster than that to Co-HoSF, indicating that the Co cores in AvBF are more accessible to reduction than the Co cores in HoSF. The presence of nonconductive (SiO2) or conductive (gold) surfaces known to bind ferritins enhances the rate of electron transfer. A more than approximately 4-fold increase in the apparent reaction rate is observed in the presence of gold. Although both surfaces (SiO2 and gold) enhance reaction by providing binding sites for molecular interaction, results show that ferritins with different mineral cores bound to a gold surface transfer electrons through the gold substrate so that direct contact of the reacting molecules is not required.

Animals↗
PubMed2006

[Current infection of Mycoplasma pneumoniae in adults: clinical analysis of 13 hospitalized patients].

OBJECTIVE: To investigate the clinical characteristics of Mycoplasma pneumoniae (MP) current infection in adults. METHODS: The clinical data of 13 patients in Beijing, 7 males and 6 females, aged 21.9 (17 - 34), hospitalized from April 2003 to April 2004, were reviewed retrospectively. RESULTS: Seven of the 13 patients were the schoolmates of the same military school, 3 being in the same class but not living in the same dormitory, 3 being hospitalized with an interval of 5 days and 2 with an interval of 2 days. A 4-fold or higher titer rise was found 16 - 17 days after the onset of symptoms. Six cases showed antibody negative at the first visit (2 - 8 days after the onset). The most common symptoms included fever (13/13), cough (11/13), mild headache (5/13), and sore throat (5/13). No symptoms of sneeze, nasal obstruction, skin rash, and ear pain were found. There was no leukocytosis. Ten patients had pneumonia confirmed by X-ray examination. Appropriate macrolide plus quinolones were effective in the treatment. However, there was no significant difference between the curative effect of erythromycin and that of azithromycin. CONCLUSION: MP mainly attacks young people and mainly causes pneumonia. Extrapulmonary complication is rare. It is not advisable to use a single high antibody titer as the criterion for diagnosis of MP current infection.

Adolescent↗
PubMed2006

Relation between charge-based apolipoprotein B-containing lipoprotein subfractions and remnant-like particle cholesterol levels.

OBJECTIVE: Both mildly modified LDL subfraction that carries a more-negative electric charge and remnant-like particles (RLP) are closely related to triglyceride (TG) levels. We examined the relation between the RLP-cholesterol (C) level and charge-based apolipoprotein (apo) B-containing lipoprotein subfractions as determined by capillary isotachophoresis (cITP) in patients with hypercholesterolemia. METHODS AND RESULTS: cITP apo B lipoprotein subfractions were identified by analyzing plasma depleted of the related lipoproteins. While fast-migrating triglyceride-rich lipoprotein (fTRL) subfraction contained both chylomicrons and VLDL fraction, slow TRL (sTRL) only contained VLDL. cITP fLDL also contained VLDL fraction, i.e., beta-VLDL. Levels of cITP fTRL and sTRL were significantly correlated with serum levels of TG, RLP-C, apo C-II, and C-III. Levels of cITP sTRL were also correlated with apo E. Levels of cITP fLDL were positively correlated with not only LDL-C levels but also levels of TG, RLP-C, apo C-II, C-III, and E. CONCLUSION: cITP fast LDL correlated with RLP-C levels and modified the relation between RLP-C and TG levels.

Adult↗
PubMed2006

[Amplification and specific expression of T-bet gene in nasal NK/T cell lymphoma].

OBJECTIVE: To investigate the specific genetic alterations in nasal NK/T cell lymphoma (N-NK/T-L) and the significance thereof. METHODS: Restriction landmark genomic scanning (RLGS) was performed on the specimen of a case of N-NK/T-L and the peripheral blood leukocytes of the same case. The RLGS image was analyzed with the Virtual genome scan (VGS) software so as to discover abnormality of T-bet gene. The discovered abnormal gene underwent cloning and preparation of probes. Southern blotting and dot blotting were performed on 3 cases of fresh N-NK/T-L tumor tissues and the genome of the case of peripheral blood lymphocytes. The expression of the T-bet (T-box expressed in T cell) gene in the tissue sections of 20 cases of N-NK/T-L, 17 cases of B cell lymphoma (BCL), 3 cases of normal spleen, and 5 cases of chronic nasopharyngitis was detected by in situ hybridization. RESULTS: RLGS combined with VGS revealed a genomic alteration in the T-bet gene and consequent Southern and dot blotting confirmed this genomic alteration in the N-NK/T-L cells. In situ hybridization showed that the T-bet mRNA expression rate of the N-NK/T-L cells was 90.0% (18/20), significantly higher than that of the BCL (11.8%, 2/17, P < 0.01). T-bet mRNA expression was not detected in the normal spleen and chronic nasopharyngitis tissues. CONCLUSION: The amplification and over-expression of the T-bet gene may play a role in the development of N-NK/T-L. The potential value of over-expression of T-bet gene in diagnosis of N-NK/T-L is worth further investigating.

Blotting, Southern↗
PubMed2006

Electrochemistry of nanopore electrodes in low ionic strength solutions.

The steady-state voltammetric behavior of truncated conical nanopore electrodes (20-200 nm orifice radii) has been investigated in low ionic strength solutions. Voltammetric currents at the nanopore electrode reflect both diffusive and migrational fluxes of the redox molecule and, thus, are strongly dependent on the charge of the redox molecule and the relative concentrations of the supporting electrolyte and redox molecule. In acetonitrile solutions, the limiting current for the oxidation of the positively charged ferrocenylmethyltrimethylammonium ion is suppressed at low supporting electrolyte concentrations, while the limiting current for the oxidation of the neutral species ferrocene is unaffected by the ionic strength. The dependence of the limiting current on the relative concentrations of the supporting electrolyte and redox molecule is accurately predicted by theory previously developed for microdisk electrodes. Anomalous values of the voltammetric half-wave potential observed at very small nanopore electrodes (<50 nm radius orifice radii) are ascribed to a boundary potential between the pore interior and bulk solution (i.e., a Donnan-type potential).

Electrochemistry↗
PubMed2006

Making the cut: protease-mediated regulation of angiogenesis.

Angiogenesis is an integral element of normal physiologic development as well as of wound healing and a variety of pathologic conditions. Since the earliest studies of the cellular processes required for the formation of new capillaries from preexisting vessels, proteolysis has been recognized as one of the earliest and most sustained activities involved in these events. Several proteases including matrix metalloproteases (MMPs), and the closely related ADAM (a disintegrin and metalloprotease domain) and ADAMTS (a disintegrin and metalloprotease domain with thrombospondin motifs) families, as well as cysteine and serine proteases, have been implicated in this regulation. The current review addresses the contribution of these proteases in the positive and negative regulation of angiogenesis as mediated by degradation of the endothelial basement membrane and extracellular matrix proteins, release of angiogenic factors, processing of cytokines, growth factors and growth factor receptors, and the production of endogenous inhibitors.

Animals↗
PubMed2006

Steady-state voltammetric response of the nanopore electrode.

The steady-state voltammetric response of the truncated conical-shaped glass nanopore electrode is presented. Analytical theory, finite-element simulations, and experimental measurement of the diffusive flux of a redox molecule through the pore orifice demonstrate that the steady-state current decreases rapidly as the pore depth increases and then asymptotically approaches a constant value when the pore depth is approximately 50x larger than the pore orifice. The asymptotic limit of the steady-state current is only a function of the pore orifice radius and the cone angle of the pore and has a finite value for all cone angles greater than zero. Experimental confirmation of the predicted dependence on pore depth is obtained using nanopore electrodes with 100-1000 nm orifice radii, by measuring the steady-state voltammetric current corresponding to the oxidation of ferrocene in acetonitrile solutions containing an excess of supporting electrolyte.

Computer Security↗
PubMed2006

Substance P immunoreactive fibers of synovial tissue in patients with anterior cruciate ligament injury.

Substance P, a neuropeptide, exerts proinflammatory effects and transmits the sensation of pain. Substance P immunoreactive fibers of the synovial tissue were examined to investigate the significance of Substance P in the traumatic joint. Biopsy specimens from 15 patients (eight female and seven male) with anterior cruciate ligament (ACL) injury were examined immunohistochemically with semi-quantitative counting to correlate Substance P positive fibers of the synovial tissue with clinical data, pain intensity on a visual analog scale, and serous inflammatory indicators. The total (sum of the three compartments) expression of Substance P in females of 571.9+/-255.1 cm(-2) was significantly greater than that of males of 241.2+/-126.6 cm(-2). In the female group, the total number of Substance P immunoreactive fibers was significantly correlated with pain intensity (r=0.804); in the male group, there was no significant correlation with pain intensity. The expression of Substance P in the female infrapatellar fat pad was statistically significantly correlated with pre- and postoperative erythrocyte sedimentation rate as inflammation indicators. In the male group, there was no such correlation. Substance P was well- correlated with pain and inflammatory reaction in the female joint. Neural inflammation and neural pain occur more strongly in female joints.

Adolescent↗
PubMed2006

The impact of tobacco tax cuts on smoking initiation among Canadian young adults.

BACKGROUND: Although the majority of smokers initiate smoking during their teenage years, significant rates of initiation occur among young adults. Adolescents are more price sensitive than adults, but little is known about the impact of tobacco taxation on smoking initiation among young adults. Using a longitudinal design, this study examined the impact of decreased cigarette price, resulting from tobacco tax cuts, on smoking initiation among Canadian young adults aged 20 to 24 years. METHODS: Using Statistics Canada's National Population Health Survey longitudinal file, this study examined young adults who did not smoke at baseline in 1994-1995 (n=636, representing over 1 million young adults) and who were reassessed at follow-up (1996-1997). Multivariable logistic regression analysis using bootstrap weights was conducted to estimate the impact of decreased cigarette price on smoking initiation. The analysis controlled for the potential confounding effect of sociodemographic and tobacco control variables. Sensitivity analyses were conducted. Price elasticity was estimated. Analyses were conducted in 2003 and 2004. RESULTS: Approximately 10% of young adults had initiated smoking at follow-up. Decreased cigarette price was significantly associated with higher smoking initiation (adjusted odds ratio per $1 decrease for a carton of cigarettes=1.15, 95% confidence interval [CI]=1.01-1.32, p=0.042). Sensitivity analyses showed similar results. Price elasticity was 3.36 (95% CI=0.07-6.75). CONCLUSIONS: Young adults are sensitive to cigarette prices. Reductions in cigarette prices will lead to increased smoking initiation among this group. Tobacco taxation should be an effective strategy to reduce smoking initiation among young adults.

Adult↗
PubMed2006

Immunohistochemical and genetic analysis of Chinese nasal natural killer/T-cell lymphomas.

Nasal natural killer/T-cell lymphoma (N-NK/T-L) is prevalent in China. To further characterize this neoplasm, 36 cases of N-NK/T-L from 304 cases of malignant lymphomas in the north China area were investigated by histopathology, immunophenotyping, and genomic analysis of c-kit, in comparison with 11 cases of B-cell lymphoma (BCL) at the same region and 5 cases of nodal peripheral T-cell lymphoma (PTCL) (unspecified). Histopathologically, N-NK/T-L was characterized by coagulative necrosis, inflammatory background, and angiodestructive growth pattern. In 36 cases of N-NK/T-L, 27 cases (75.0%) were stained for CD45RO and 25 (72.2%) for CD3epsilon. Thirty cases (83.3%) were positive for T-cell intracellular antigen-1, 22 (61.1%) for granzyme B, 18 (50.0%) for CD56, and 11 (30.6%) for CD30, whereas none was positive for CD117. All 5 cases of PTCL displayed positive staining for CD45RO and T-cell intracellular antigen-1, 3 cases for CD3epsilon, but only 1 case for granzyme B. All 11 BCLs presented positive staining for CD20 and CD79a but negative for other antibodies. A significant relationship was observed between neoplastic cells pleomorphism and granzyme B expression (P < .05). Despite the fact that all cases were negative for CD117 staining, genomic sequences of c-kit 11 and exon 17 sequencing showed that 8 (26%) of 31 cases N-NK/T-L proved to contain genomic mutations, including 4 cases in exon 11 and 4 in exon 17. For the control group, only 1 (9%) of 11 BCLs and 1 (20%) of 5 cases of PTCL were detected to harbor mutations in exon 11. All mutations detected in 3 groups were missense by base substitution, and codes 571, 572, and 821 were hot spots. The results suggested that, in addition to histological features and routine immunophenotyping, granzyme B expression should be a more reliable marker in correct diagnosis of N-NK/T-L, and genetic analysis of c-kit mutation should be helpful in the diagnosis of this tumor.

Adolescent↗
PubMed2006

Prevention of ischemic neuronal death by intravenous infusion of a ginseng saponin, ginsenoside Rb(1), that upregulates Bcl-x(L) expression.

Almost all agents that exhibit neuroprotection when administered into the cerebral ventricles are ineffective or much less effective in rescuing damaged neurons when infused into the blood stream. Search for an intravenously infusible drug with a potent neuroprotective action is essential for the treatment of millions of patients suffering from acute brain diseases. Here, we report that postischemic intravenous infusion of a ginseng saponin, ginsenoside Rb(1) (gRb(1)) (C(54)H(92)O(23), molecular weight 1109.46) to stroke-prone spontaneously hypertensive rats with permanent occlusion of the middle cerebral artery distal to the striate branches significantly ameliorated ischemia-induced place navigation disability and caused an approximately 50% decrease in the volume of the cortical infarct lesion in comparison with vehicle-infused ischemic controls. In subsequent studies that focused on gRb(1)-induced expression of gene products responsible for neuronal death or survival, we showed that gRb(1) stimulated the expression of the mitochondrion-associated antiapoptotic factor Bcl-x(L) in vitro and in vivo. Moreover, we revealed that a Stat5 responsive element in the bcl-x promoter became active in response to gRb(1) treatment. Ginsenoside Rb(1) appears to be a promising agent not only for the treatment of cerebral stroke, but also for the treatment of other diseases involving activation of mitochondrial cell death signaling.

Animals↗
PubMed2006

The spleen as a target in severe acute respiratory syndrome.

It has been proposed that immune injury is the central mechanism of pathogenesis of the infectious disease, severe acute respiratory syndrome (SARS). To gain a better understanding of immune injury in the spleen, we investigated the number and distribution of various immune cell types in the spleens of SARS patients. We performed autopsies on six confirmed SARS cases, with six normal subjects as controls; spleen samples from these autopsies were examined with hematoxylin and eosin (H&E) sections, in situ hybridization for SARS virus genomic sequences, and immunohistochemistry with seven monoclonal antibodies to five cell types. The number and distribution of these cells were measured and analyzed using an image analysis system. SARS genomic sequences were detected in all SARS spleens. The SARS spleens all had severe damage to the white pulp and showed an alteration of the normal distribution of various cell types. Immunocytes in the red pulp were decreased by 68.0-90.7% except for CD68+ macrophages and human leukocyte antigen (HLA)-DR positive antigen-presenting cells (APC), which were decreased to a lesser degree. On average, CD68+ macrophages were increased in size by 2.21-fold. We hypothesize that the collapse of the splenic immune system plays a key role in the clinical outcome of these patients.

Adult↗
PubMed2006

A Na+/H+ antiporter gene of the moderately halophilic bacterium Halobacillus dabanensis D-8T: cloning and molecular characterization.

A gene encoding a Na(+)/H(+) antiporter was cloned from a chromosomal DNA of Halobacillus dabanensis strain D-8(T) by functional complementation. Its presence enabled the antiporter-deficient Escherichia coli strain KNabc to survive in the presence of 0.2 M NaCl or 5 mM LiCl. The gene was sequenced and designated as nhaH. The deduced amino-acid sequence of NhaH consists of 403 residues with a calculated molecular mass of 43,481 Da, which was 54% identical and 76% similar to the NhaG Na(+)/H(+) antiporter of Bacillus subtilis. The hydropathy profile was characteristic of a membrane protein with 12 putative transmembrane domains. Everted membrane vesicles prepared from E. coli cells carrying nhaH exhibited Na(+)/H(+) as well as Li(+)/H(+) antiporter activity, which was pH-dependent with highest activities at pH 8.5-9.0 and at pH 8.5, respectively. Moreover, nhaH confers upon E. coli KNabc cells the ability to grow under alkaline conditions.

Amino Acid Sequence↗
PubMed2006

The pha2 gene cluster involved in Na+ resistance and adaption to alkaline pH in Sinorhizobium fredii RT19 encodes a monovalent cation/proton antiporter.

Sinorhizobium fredii RT19 can tolerate up to 0.6 M NaCl, whereas all its pha2-disrupted mutants, constructed by Tn5 mutagenesis, failed to grow in even the presence of 0.1 M NaCl. No growth difference was detected in pha2 mutants at a pH<7.5 in the presence or absence of K+, but growth reduction was observed in the presence of K+ when pH>7.5. The pha2 gene cluster was able to completely restore the growth of the pha2 mutants of S. fredii RT19 in 0.6 M NaCl. Measurement of monovalent cation intracellular content suggested that pha2 was involved in both Na+ (Li+) and K+ efflux. The pha2 mutants exhibited K+/H+, but no apparent Na+(Li+)/H+ antiporter activity in everted membrane vesicles. Taken together, these results indicated that the pha2 cluster of S. fredii RT19 encodes a monovalent cation/proton antiporter involved in resistance to Na+ and adaption to pH, which was very different from the pha1 cluster of Sinorhizobium meliloti, which encodes a K+/H+ antiporter.

Cation Transport Proteins↗
PubMed2006

Bullying and smoking: Examining the relationships in Ontario adolescents.

Using data from the 2003 Ontario Student Drug Use Survey (Centre for Addiction and Mental Health, Toronto), the relationships between bullying and smoking in adolescents were examined. A representative sample of 3314 grade 7-12 students was included in the analysis. Models were adjusted for confounders identified in the current literature. Multinomial logistic regression showed that current smokers were more likely to be bullies than nonsmokers (relative risk ratio = 2.3, p < .001); being a current smoker was not associated with being a victim or a bully/victim (one who is both a bully and a victim). Moreover, gender was found to modify the effect of smoking on bullying status. Female smokers were more likely to be bullies and bully/victims than nonsmokers while there were no statistically significant differences for males. The associations between bullying status and smoking are consistent with those found in a multinational World Health Organization survey of adolescent health. Findings of the study suggested that girls were at much higher risk for involvement in bullying if they smoked, although girls were less frequently involved in bullying.

Adaptation, Psychological↗
PubMed2006

Serum bactericidal activities of high-dose daptomycin with and without coadministration of gentamicin against isolates of Staphylococcus aureus and Enterococcus species.

The purpose of this experiment was to evaluate the pharmacokinetics and serum bactericidal titers (SBTs) of daptomycin alone and in combination with gentamicin against strains of Staphylococcus aureus and enterococci to determine if there might be any benefit to the addition of the aminoglycoside. A multiple-dose, randomized crossover study was performed in 11 healthy volunteers to evaluate the steady-state pharmacokinetic profile of 6 mg/kg of body weight daptomycin once daily with or without 1 mg/kg gentamicin every 8 h. SBTs were determined against clinical isolates of nosocomial (MRSA 494) and community-acquired (CA-MRSA 44) methicillin-resistant S. aureus, vancomycin-susceptible Enterococcus faecalis (VSEF 49452), vancomycin-resistant Enterococcus faecium (VREF 80), and quality control strains of methicillin-susceptible S. aureus (ATCC 29213) and vancomycin-susceptible E. faecalis (ATCC 29212). Enhancement of bactericidal activity was evaluated by calculating and comparing the areas under the bactericidal curve (AUBC) for each dosing regimen against each isolate. The area under the concentration-time curve from 0 to 24 h and clearance for daptomycin alone were 645 +/- 91 microg.h/ml and 9.47 +/- 1.4 mg/h/kg, respectively, compared with 642 +/- 69 microg.h/ml and 9.45 +/- 1.0 mg/h/kg for daptomycin plus gentamicin. Daptomycin alone displayed sustained bactericidal activity against five of the six isolates over the entire 24-h dosing interval; bactericidal activity was maintained for 8 h against VREF 80. Mean AUBCs for daptomycin alone ranged from 935 to 1,263 and 36 to 238 against staphylococcal and enterococcal isolates, respectively, compared with 902 to 972 and 34 to 213 against staphylococci and enterococci when coadministered with gentamicin. The results of this study suggest that the addition of gentamicin does not alter the pharmacokinetic profile or enhance the bactericidal activity of daptomycin against staphylococcal or enterococcal isolates.

Adolescent↗