Biomedical subjects

Bin Luo

Publications and source records attributed to Bin Luo.

At least 19 recordsLinked to original sources

PubMed2026

Molecular epidemiology and antimicrobial resistance of human Streptococcus suis isolates in Guangxi, China, 2015-2021.

BACKGROUND: Streptococcus suis (S. suis) is an important zoonotic pathogen and a common colonizer of the upper respiratory tract of pigs. Human infections have been reported in several regions of China, including Guangxi, but genomic and antimicrobial resistance data from this region remain limited. This study investigated the molecular epidemiology, antimicrobial susceptibility, and genomic characteristics of human S. suis isolates collected in Baise City, Guangxi, from 2015 to 2021. METHODS: This retrospective study included 39 non-duplicate clinical isolates confirmed as S. suis by whole-genome analysis. Antimicrobial susceptibility testing was performed using a broth microdilution-based system and interpreted according to the Clinical and Laboratory Standards Institute guidelines. Serotypes were determined by agglutination using type-specific antisera. Whole-genome sequencing was used for species confirmation, multilocus sequence typing, detection of antimicrobial resistance and virulence-associated genes, and core-protein phylogenetic analysis. RESULTS: The median patient age was 55 years, and 36/39 (92.3%) patients were male. Meningitis was documented in 34/39 (87.2%) patients, and hearing impairment occurred in 21/39 (53.8%). Pig- or pork-related exposure was recorded in 15/39 (38.5%) patients. Resistance was highest to tetracycline (38/39, 97.4%), followed by erythromycin and clindamycin (26/39, 66.7% each). Four isolates (10.3%) showed intermediate susceptibility to penicillin, but none were resistant. All isolates remained susceptible to ampicillin, ceftriaxone, levofloxacin, linezolid, vancomycin, and meropenem. Serotype 2 predominated (32/39, 82.1%), followed by serotype 14 (7/39, 17.9%), while ST1 (29/39, 74.4%) and ST7 (7/39, 17.9%) were the two major sequence types. Resistance genes were mainly associated with tetracyclines, macrolides, lincosamides, and aminoglycosides. All ST1 isolates carried mrp and lacked tet(40), while all ST7 isolates showed the reverse pattern. CONCLUSION: Serotype 2 and ST1 predominated among the human S. suis isolates collected at this center. Resistance to tetracycline, erythromycin, and clindamycin was common, while susceptibility to the β-lactams tested was largely preserved. Differences in virulence- and resistance-associated gene profiles were also observed between the major lineages, indicating distinct genetic characteristics among the locally circulating isolates.

Streptococcus suis↗

PubMed2025

Cancer-testis antigen ACRBP: Cytotoxic response to its HLA-A2 restricted peptide and immune features in ovarian cancer.

While our prior study identified the HLA-A *0201-restricted ACRBP epitope peptide and demonstrated its capacity to generate cytotoxic T lymphocytes (CTLs) in vitro, the clinical relevance of the peptide-induced T cell reactivity in ovarian cancer (OC) patients and the in vivo anti-tumor efficacy of these CTLs remain unexplored. In this study, dendritic cells were sensitized with ACRBP peptide (ALLVLCYSI) and co-cultured with autologous CD8+T cells to induce the production of specific cytotoxic T lymphocytes (Pep-CTLs). The anti-tumor effects of Pep-CTLs were evaluated in SCID mice bearing human ovarian cancer (OC) OVCAR-3 cells. Concurrently, we co-cultured ALLVLCYSI peptide with peripheral blood mononuclear cells (PBMCs) from OC patients (HLA-A2+, ACRBP+) and assessed the number of specific T cells using ELISPOT assays. The immunological impact of the ACRBP peptide against human OC was validated through both in vitro and in vivo experiments. These findings establish a preclinical foundationfor developing ACRBP peptide-based vaccines in OC immunotherapy. To further elucidate ACRBP's role in OC treatment, the study analyzed single-cell RNA sequencing data from 8 OC patients and bulk RNA sequencing data from the Cancer Genome Atlas Project (TCGA) comprising 308 ovarian cancer cases. This analysis aimed to explore the heterogeneity among ACRBP-expressing tumor cell populations and to investigate the correlation between ACRBP expression and immune molecule expression (including MHC and chemokines) alongside chemotherapy response. These insights furnish a theoretical framework supporting the future application of ACRBP in tumor immunotherapy and strategies to prevent immune escape.

Humans↗

PubMed2006

[Improved method of acute myocardial ischemic rat model].

OBJECTIVE: To improve the successful rate of operation and the livability in establishing acute myocardial ischemic rat model. METHODS: The successful rate of animal experiment is compared between traditional method and improved method. RESULTS: The successful rate of improved method was 90%, which was much higher than 30% in successful rate of traditional method. CONCLUSION: The improved method may reduce the difficulty of operation remarkably and cut down the experiment expenditure, which is superior to traditional method.

Acute Disease↗

PubMed2006

Sodium salicylate reduces inhibitory postsynaptic currents in neurons of rat auditory cortex.

Sodium salicylate (SS) is a medicine for anti-inflammation and for chronic pain relief with a side effect of tinnitus. To understand the cellular mechanisms of tinnitus induced by SS in the central auditory system, we examined effects of SS on evoked and miniature inhibitory postsynaptic currents (eIPSCs and mIPSCs) recorded from layer II/III pyramidal neurons of rat auditory cortex in a brain slice preparation with whole-cell patch-clamp techniques. Both eIPSCs and mIPSCs recorded from the auditory cortex could be completely blocked by bicuculline, a selective GABA(A) receptor antagonist. SS did not change the input resistance of neurons but was found to reversibly depress eIPSCs in a concentration-dependent manner. SS reduced eIPSCs to 82.3% of the control level at 0.5 mM (n=7) and to 60.9% at 1.4 mM (n=12). In addition, SS at 1.4 mM significantly reduced the amplitude of mIPSCs from 24.12+/-1.44 pA to 19.92+/-1.31 pA and reduced the frequency of mIPSCs from 1.34+/-0.23 Hz to 0.89+/-0.13 Hz (n=6). Our results demonstrate that SS attenuates inhibitory postsynaptic currents in the auditory cortex, suggesting that the alteration of inhibitory neural circuits may be one of the cellular mechanisms for tinnitus induced by SS in the central auditory region.

Animals↗

PubMed2006

Effects of unwanted feedback on synchronized chaotic optical communications.

The effects of unwanted external optical feedback on synchronized chaotic optical communication systems are studied numerically. We consider an open-loop configuration consisting of a transmitter laser with double external optical feedbacks and a receiver laser with optical injection from the transmitter laser. First, including the effects of unwanted optical feedback, the synchronization performances of both the complete synchronization and the generalized synchronization are examined. Then the encoding and decoding performances of the generalized synchronization and the effects of the introduced feedback are investigated, respectively. Finally, we study the control of the unwanted feedback on the dynamics of the transmitter laser and briefly discuss the system security when the transmitter laser is driven to operate in a steady state or periodic oscillation state by the additional feedback.

Journal Article↗

PubMed2006

Anxiolytic-like activity of oxytocin in male mice: behavioral and autonomic evidence, therapeutic implications.

RATIONALE: Oxytocin (OT) acts as a neuromodulator/neurotransmitter within the central nervous system (CNS) and regulates a diverse range of CNS functions. Notably, evidence from studies in females has revealed an important role for OT in regulating anxiety behavior. OBJECTIVES: The objective of this study was to examine the effects of OT on both behavioral and autonomic parameters of the anxiety response in male mice using three pharmacologically validated preclinical models of anxiety: the four-plate test (FPT), elevated zero maze (EZM), and stress-induced hyperthermia (SIH). RESULTS: In the FPT, both peripherally (3-30 mg/kg i.p.) and centrally (1-10 microg i.c.v.) administered OT produced dose-dependent increases in punished crossings, indicating an anxiolytic-like effect. The effects of centrally administered OT in the FPT were blocked with peripheral administration of a brain-penetrant OT receptor (OTR) antagonist WAY-162720 (30 mg/kg i.p.), and the effects of peripherally administered OT were blocked with central administration of a non-penetrant OTR antagonist L-371,257, suggesting OT acts centrally. In the EZM, centrally administered OT (0.1-1.0 microg, i.c.v.) produced significant increases in the percentage time spent in the open quadrants of the maze, comparable to alprazolam (0.5-1.0 microg, i.c.v.). In SIH, OT (1-10 mg/kg i.p.) dose-dependently attenuated stress-induced increases in core body temperature, comparable to the reference anxiolytic chlordiazepoxide (CDP) (10 mg/kg i.p.). CONCLUSIONS: These results provide specific behavioral and autonomic evidence of anxiolytic-like effects for oxytocin in males and, together with previously reported observations in females, suggest the potential utility of OTR agonism as a therapeutically relevant mechanism of action for novel anxiolytics in both sexes.

Animals↗

PubMed2006

Increasing donor chimerism and inducing tolerance to islet allografts by post-transplant donor lymphocyte infusion.

Inducing donor chimerism is the most consistently successful approach to achieve transplant tolerance. We found that a low level of donor chimerism, which was induced by a relatively non-toxic approach, induced donor-specific tolerance to islet allografts in chemically induced diabetic mice. However, a similar level of donor chimerism could not protect donor islet allografts in non-obese diabetic (NOD) mice that spontaneously developed autoimmune diabetes. Rejection of donor islet allografts in diabetic NOD mice with a low level of donor chimerism was mediated by recurrent autoimmunity. We used post-transplant donor lymphocyte infusion (DLI) to increase donor chimerism and to induce tolerance to islet allografts. DLI significantly increased donor chimerism and promoted donor-specific tolerance to islet allografts in diabetic NOD mice. Self-tolerance to islet autoantigens was restored and restoring self-tolerance is mediated by immunoregulation. Thus, our data showed that adoptive immunotherapy with post-transplant DLI after establishing a low level of donor chimerism as a platform enhances donor chimerism, induces donor-specific tolerance to islet allografts and restores self-tolerance in the setting of autoimmune diabetes. Our data also showed that central tolerance is not sufficient to induce tolerance and peripheral tolerance through immunoregulation for restoring self-tolerance is required in the setting of autoimmune diabetes.

Adoptive Transfer↗

PubMed2006

Costimulation blockade of both inducible costimulator and CD40 ligand induces dominant tolerance to islet allografts and prevents spontaneous autoimmune diabetes in the NOD mouse.

Costimulation blockade is a promising strategy for preventing allograft rejection and inducing tolerance. Using a fully allogeneic mouse model, we tested the effectiveness of the combined blockade of the CD40 ligand and the inducible costimulator (ICOS) on islet allograft survival and in the prevention of autoimmune diabetes in the NOD mouse. Recipients treated with blocking monoclonal antibodies (mAbs) to ICOS and the CD40 ligand had significant prolongation of graft survival, with 26 of 28 functioning for >200 days. Long-term engrafted mice maintained antidonor proliferative and cytotoxic responses, but donor-specific immunization did not induce graft rejection, and challenge with second, same donor but not third-party grafts resulted in long-term acceptance. The immunohistology of tolerant grafts demonstrated the presence of CD4(+)CD25(+) T-cells expressing Foxp3, and islet/kidney composite grafts from tolerant mice, but not from mice lacking lymphocytes, were accepted indefinitely when transplanted into naïve B6 mice, suggesting that recipient T-cells were necessary to generate dominant tolerance. Combined anti-ICOS and anti-CD40 ligand mAb therapy also prevented diabetes in NOD mice, with only 11% of treated recipients developing diabetes compared with 75% of controls. These data demonstrate that the blockade of CD40 ligand and ICOS signaling induces islet allograft tolerance involving a dominant mechanism associated with intragraft regulatory cells and prevents autoimmune diabetes in NOD mice.

Animals↗

PubMed2006

[Pathologic changes of the cardiac conduction system in 12 patients with abnormal ECG].

OBJECTIVE: To investigate the relationship between abnormal ECG and pathologic changes in the cardiac conduction system (CCS). METHOD: Pathological changes of the CCS in 12 cases with abnormal ECG out of 16 pre-death ECG were observed. RESULTS: (1) Among 7 cases of sudden cardiac death, ECG monitoring recorded bradyarrhythmia in 6 cases, tachyarrhythmia 6 cases, bradycardia-tachycardia syndrome 2 cases, conduction block 6 cases, atrial premature beats 6 cases, ventricular premature beats 6 cases, and ST-T changes 4 cases. (2) The histopathological findings in the CCS were noted in all cases. Of these 12 cases, three had signs of fatty infiltration, and/or fibrous 4 cases, three of amyloidosis, one of chronic inflammatory changes, two of acute inflammatory changes, two of developmental anomalies, two of hemorrhages and one of LAD stenosis. (3) Acute inflammation changes in the CCS corresponded to tachyarrhythmia and multiple ventricular premature beats, whereas chronic inflammation and degenerative changes in the CCS were often related to bradyarrhythmia, bradycardia-tachycardia syndrome and conduction block. (4) The CCS changes alone could lead to ST-T changes in ECG. CONCLUSION: The pathological changes in the CCS are related to ECG changes, and attributed to the pathological bases of arrhythmia.

Adolescent↗

PubMed2005

Robust tolerance to fully allogeneic islet transplants achieved by chimerism with minimal conditioning.

BACKGROUND: Whether mixed chimeras induced by nonmyeloablative conditioning are tolerant to challenge with donor allogeneic islet grafts is unknown. Here we investigate whether our nonmyeloablative, costimulation blockade-free and sirolimus (SRL)-based protocol could facilitate mixed chimerism via bone marrow transplantation (BMT) and induce islet allograft tolerance. METHODS: After low dose (1-3 Gy) total body irradiation (TBI, day -1), with or without prior lymphocyte depletion, C57BL/6 mice were transfused with 40 x 10(6) BALB/c bone marrow cells (day 0) and received SRL (3 mg/kg/day) for 4 weeks. Chimerism was monitored by flow cytometry and the recipients were rendered diabetic chemically and challenged with donor islets. RESULTS: Mixed chimerism was achieved in mice treated with TBI 3 Gy/SRL but it declined over time in 60% (9/15) of them. Long-term stable chimerism was established in 100% of recipients over 50 weeks with either antilymphocyte serum (ALS, 9/9), anti-CD4 (4/4), or anti-CD4 plus anti-CD8 (5/5) prior to BMT. TBI conditioning could be reduced to 1 Gy, with 90% (9/10) maintaining chimerism in the long-term. When TBI was substituted with cyclophosphamide (CTX) or busulfan (BUS), all mice remained chimeric in the long-term. The chimeras showed no proliferative response to donor antigen and accepted both first and second donor-specific islet grafts indefinitely while rejecting third-party grafts. CONCLUSIONS: This data provides the first evidence that stable fully allogeneic chimeras induced with BMT after nonmyeloablative conditioning with SRL and lymphocyte-depleting antibodies exhibit robust donor-specific tolerance to islet grafts.

Animals↗

PubMed2005

Pattern vectors from algebraic graph theory.

Graph structures have proven computationally cumbersome for pattern analysis. The reason for this is that, before graphs can be converted to pattern vectors, correspondences must be established between the nodes of structures which are potentially of different size. To overcome this problem, in this paper, we turn to the spectral decomposition of the Laplacian matrix. We show how the elements of the spectral matrix for the Laplacian can be used to construct symmetric polynomials that are permutation invariants. The coefficients of these polynomials can be used as graph features which can be encoded in a vectorial manner. We extend this representation to graphs in which there are unary attributes on the nodes and binary attributes on the edges by using the spectral decomposition of a Hermitian property matrix that can be viewed as a complex analogue of the Laplacian. To embed the graphs in a pattern space, we explore whether the vectors of invariants can be embedded in a low-dimensional space using a number of alternative strategies, including principal components analysis (PCA), multidimensional scaling (MDS), and locality preserving projection (LPP). Experimentally, we demonstrate that the embeddings result in well-defined graph clusters. Our experiments with the spectral representation involve both synthetic and real-world data. The experiments with synthetic data demonstrate that the distances between spectral feature vectors can be used to discriminate between graphs on the basis of their structure. The real-world experiments show that the method can be used to locate clusters of graphs.

Algorithms↗

PubMed2004

A direct quantitative analysis method for monitoring biogenic volatile organic compounds released from leaves of Pelargonium hortorum in situ.

A direct quantitative method is presented that is based upon the use of multiple headspace solid phase microextraction (HS-SPME) to monitor biogenic volatile organic compounds (BVOCs) released from a living leaf of Pelargonium hortorum in situ. Seventeen BVOCs were detected by GC-MS after a single SPME extraction using a CAR/DVB/PDMS fibre. An internal standard was employed to determine the absolute amounts of seven terpenoid compounds released from a P. hortorum leaf. The quantitative analysis was performed over two days, with extraction preformed for 20 min every 3 h. The amount of volatiles extracted varied with the time of day, with two maxima recorded at 14:00 (day 1) and 17:00 (day 2), corresponding to 236 and 277 ng of the seven terpenoids recorded, respectively. These results indicate that multiple HS-SPME in combination with an internal standard is a simple, quick, and quantitative technique for analysising BVOC emissions from a live plant sample.

Calibration↗

PubMed2004

Control of plant trichome development by a cotton fiber MYB gene.

Cotton (Gossypium spp) plants produce seed trichomes (cotton fibers) that are an important commodity worldwide; however, genes controlling cotton fiber development have not been characterized. In Arabidopsis thaliana the MYB gene GLABRA1 (GL1) is a central regulator of trichome development. Here, we show that promoter of a cotton fiber gene, RD22-like1 (RDL1), contains a homeodomain binding L1 box and a MYB binding motif that confer trichome-specific expression in Arabidopsis. A cotton MYB protein GaMYB2/Fiber Factor 1 transactivated the RDL1 promoter both in yeast and in planta. Real-time PCR and in situ analysis showed that GaMYB2 is predominantly expressed early in developing cotton fibers. After transferring into Arabidopsis, GL1::GaMYB2 rescued trichome formation of a gl1 mutant, and interestingly, 35S::GaMYB2 induced seed-trichome production. We further demonstrate that the first intron of both GL1 and GaMYB2 plays a role in patterning trichomes: it acts as an enhancer in trichome and a repressor in nontrichome cells, generating a trichome-specific pattern of MYB gene expression. Disruption of a MYB motif conserved in intron 1 of GL1, WEREWOLF, and GaMYB2 genes affected trichome production. These results suggest that cotton and Arabidopsis use similar transcription factors for regulating trichomes and that GaMYB2 may be a key regulator of cotton fiber development.

Amino Acid Motifs↗

PubMed2004

Ex planta phytoremediation of trichlorophenol and phenolic allelochemicals via an engineered secretory laccase.

Plant roots release a range of enzymes capable of degrading chemical compounds in their immediate vicinity. We present a system of phytoremediation ex planta based on the overexpression of one such enzyme, a secretory laccase. Laccases catalyze the oxidation of a broad range of phenolic compounds, including polychlorinated phenols such as 2,4,6-trichlorophenol (TCP), that are among the most hazardous and recalcitrant pollutants in the environment. We isolated a secretory laccase cDNA of LAC1, which is specifically expressed in the roots of Gossypium arboreum (cotton). Transgenic Arabidopsis thaliana plants overexpressing LAC1 exhibited enhanced resistance to several phenolic allelochemicals and TCP. The secretory laccase activity in these plants was responsible for the conversion of sinapic acid into a mono-lactone type dimer and for the transformation of TCP.

Arabidopsis↗

PubMed2004

Multiple combination therapies involving blockade of ICOS/B7RP-1 costimulation facilitate long-term islet allograft survival.

In recent years a series of novel costimulatory molecules have been identified, including inducible costimulator (ICOS). In a fully major histocompatibility complex (MHC)-mismatched mouse model of islet transplantation, we demonstrate that while monotherapy with CTLA4-Ig, CD40 ligand monoclonal antibody (CD40L mAb) or rapamycin each improves islet allograft survival, graft rejection eventually develops. Immunohistologic analysis of rejected grafts revealed increased ICOS expression, suggesting a role for this costimulatory molecule as an alternate pathway for T-cell activation. The combination of a blocking anti-ICOS mAb with each of the above therapies resulted in significantly improved islet allograft survival, confirming the importance of ICOS signaling in islet allograft rejection. Mechanistic studies conducted in mice treated with anti-ICOS mAb and rapamycin demonstrated a lack of donor-specific immunological tolerance and an absence of regulatory T-cell activity. However, a dramatic effect was seen on acute anti-donor responses whereby anti-ICOS mAb and rapamycin significantly reduced the initial expansion and function of alloreactive T cells. These data demonstrate that blockade of the ICOS/B7RP-1 pathway has potential therapeutic benefit given its role in enhancing islet allograft survival and regulating acute alloresponses in vivo.

Animals↗

PubMed2004

[Non-invasive detection of the boundary of early breast tumor using DSF-DOT].

Traditional biomedical imaging technology has a difficulty in detecting the boundary of a breast tumor at its early stage since the difference in the sound resistance or density between the early breast tumor and normal tissue is small. In this paper, the boundary of an early breast tumor is detected successfully by using a new method called DSF-DOT (delta sound field diffusion optical tomography), which is based on a sound field and the light diffusion theory. At the same time, the influence of the size of the acting area of the sound field on the reconstruction of the tumor boundary is investigated in details. The work is useful for further research on the diagnosis of early breast cancers.

Breast Neoplasms↗

PubMed2003

[Efficacy of gamma knife radiosurgery in treatment of growth hormone-secreting pituitary adenoma].

OBJECTIVE: To evaluate the efficacy of gamma knife radiosurgery (GKS) in treatment of growth hormone (GH)-secreting pituitary adenoma. METHODS: 149 patients with GH-secreting pituitary adenoma, 97 males and 52 females, aged 42.8 (12-72 years), with a course of 6-240 months (72.5 months) and with the mean volume of tumor of 2.36 cm(3) (0.11-12.7 cm(3)) were treated by GKS. The mean dose to tumor margin was 20.87 Gy (10-30 Gy). 124 of them were followed up for 30 months (6-72 months). RESULTS: The serum GH returned normal in 74 patients (64.9%) and declined in comparison with the level before radiosurgery in 23 patients (18.5%). The tumor volume was reduced in 84 patients (67.7%) and remained unchanged in 124 patients (32.4%). Ambiopia appeared in one patient. No other complication was found during the follow-up. CONCLUSION: GKS is safe and effective on the treatment of GH-secreting pituitary adenoma.

Adenoma↗

PubMed2003

An ATP-binding cassette transporter GhWBC1 from elongating cotton fibers.

We have isolated a cDNA (GhWBC1) from cotton (Gossypium hirsutum) that encodes an ATP-binding cassette transporter of the WBC (white/brown complex) subfamily. Members of this subfamily are half-sized transporters and are reported to mediate lipid and drug excretion in human (Homo sapiens). GhWBC1 is highly expressed in developing fiber cells, but transcripts were also detectable in other tissues except roots. The transcript level peaked in rapidly expanding fibers from 5 to 9 DPA and then decreased. The GhWBC1 expression was weak in fiber cells of an li (ligon-lintless) mutant, which is defective in fiber cell elongation. These data indicate that GhWBC1 gene expression correlates with cotton fiber elongation. Transient expression of enhanced green fluorescence protein-GhWBC1 fusion protein in onion (Allium cepa) epidermal cells revealed plasma membrane localization. The GhWBC1 cDNA driven by a constitutive 35S promoter was introduced into Arabidopsis. About 13% of the transformants produced short siliques (SSs), whereas others had normal siliques (long siliques [LSs]). In siliques of SS lines, most embryos were severely shriveled, and only several seeds per silique could be found at maturity. The transgene expression level was higher in SS lines than in LS lines. Expression of AtWBC11, the closest homolog of GhWBC1 in Arabidopsis, was not altered in either SS or LS transgenic plants examined. These data suggest that GhWBC1 interferes with substance translocation that is required for Arabidopsis seed and silique development. Characterization of Arabidopsis WBC members, particularly AtWBC11, will help to dissect the role of GhWBC1 in cotton fiber development and elongation.

ATP-Binding Cassette Transporters↗