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Biomedical subjects

Bo Tang

Publications and source records attributed to Bo Tang.

At least 19 recordsLinked to original sources

Proteomic analysis identifies pathways related to immune dysregulation in patients with hematologic malignancies after COVID-19 infection.

Patients with hematologic malignancies (HMs) are particularly vulnerable to coronavirus disease 2019 (COVID-19) because of underlying immune dysfunction and treatment-related immunosuppression. However, proteomic features associated with different clinical trajectories in this population remain insufficiently characterized. We performed serum proteomic analysis in 40 HM patients with COVID-19 and 15 healthy controls. Compared with controls, HM patients showed impaired immune-related responses during the acute phase of COVID-19. Acute-phase proteomic patterns differed across outcome groups; however, because outcome groups were closely intertwined with initial COVID-19 severity, ICU admission, and systemic illness, and because multivariable adjustment was not performed due to the limited sample size, these patterns should be interpreted as severity- and outcome-associated profiles rather than independent trajectory-specific markers. Fatal cases showed evidence of dysregulated immune activation, whereas patients later classified as having long COVID exhibited broader suppression of immune-related pathways. In addition to immune alterations, pathways related to platelet activation and cardiac-related dysfunction were associated with adverse clinical trajectories. Enzyme-linked immunosorbent assay validation supported the association of selected proteins with outcome groups during acute infection. These findings provide a proteomic overview of COVID-19 in HM patients and offer a basis for future mechanistic studies and larger external validation cohorts.IMPORTANCEPatients with hematologic malignancies are highly vulnerable to severe coronavirus disease 2019 (COVID-19), acute death, and long COVID due to preexisting immune dysfunction. However, the proteomic signatures linked to adverse clinical trajectories remain poorly understood. Our serum proteomic study identifies distinct acute-phase immune profiles associated with different outcomes: broad immune suppression characterizes long COVID, while dysregulated immune activation is associated with fatal cases. Platelet activation and cardiac-related pathways are also linked to poor outcomes. These findings provide key molecular insights for this high-risk population, supporting future biomarker development, risk stratification, and targeted clinical management.CLINICAL TRIALSThis study is registered with ClinicalTrials.gov as NCT05683353.

Humans↗

Colorectal Liver Metastasis Pathomics Model: Integrating Single-Cell and Spatial Transcriptome Analysis With Pathomics for Predicting Liver Metastasis in Colorectal Cancer.

The liver is the primary target organ for hematologic metastasis of colorectal cancer (CRC), and CRC liver metastasis (CRLM) often precludes radical resection, making it the leading cause of death in patients with CRC. To improve the identification and prediction of liver metastasis risk, we identified a cell type of liver metastasis--triggering malignant cells (LMTMCs) through integrating single-cell RNA sequencing and spatial transcriptome analysis. Multiomics cell communication analysis indicated that the interaction between fibroblasts and LMTMCs through the COL1A1-CD44/SDC4 and LAMA4-CD44 signaling axes could promote CRLM. By applying the one-class logistic regression algorithm, we developed a CRLM scoring system in the bulk RNA-sequencing data according to the abundance of LMTMCs in each individual. Using the grouping labels derived from the CRLM scoring system in the bulk data and the corresponding whole-slide images without any manual annotations at the region or pixel level, processed via slide-level weakly supervised learning, a deep-learning model based on the ResNet18 architecture, called Colorectal Liver Metastasis Pathomics Model, was developed to predict the risk of liver metastasis in patients with CRC. The Colorectal Liver Metastasis Pathomics Model achieved an area under the curve of 0.84 at the internal test set of The Cancer Genome Atlas-CRC histology images. In the external independent validation sets, namely the Affiliated Hospital of Southwest Medical University and the Affiliated Traditional Chinese Medicine Hospital of Southwest Medical University cohorts, the areas under the curve were 0.89 and 0.72, respectively, indicating effective classification performances. This study provided new insights and tools for the early identification of CRLM and demonstrated the potential of combining multiomics with deep learning-based pathomics in cancer research.

Humans↗

Design of a phosphinate-based fluorescent probe for superoxide detection in mouse peritoneal macrophages.

3',6'-Bis(diphenylphosphinyl)fluorescein (PF-1) was synthesized as a highly selective and sensitive fluorescent probe for imaging O(2) (.-) in living cells. The design strategy for the probe was based on the nucleophilic mechanism of O(2) (.-) to mediate deprotection of this probe to give fluorescein. Upon reaction with O(2) (.-), the probe exhibits a strong fluorescence response and high selectivity for O(2) (.-) over other reactive oxygen species and some biological compounds. The phosphinate-based probe, as a new fluorescent reagent, is cell-permeable and can detect micromolar changes of O(2) (.-) concentrations by using confocal microscopy in living cells. The unique combination of good selectivity, high sensitivity, good water solubility, and rapid reactivity establishes the potential value of the probe for facilitating investigations of the generation, metabolism, and mechanisms of superoxide-mediated cellular homeostasis and injury.

Animals↗

Determination of trace hydroxyl radicals by flow injection spectrofluorometry and its analytical application.

On the basis of the fluorescence increase of the reaction of ninhydrin with hydroxyl radicals, a new method for the determination of trace amounts of hydroxyl radicals by flow injection spectrofluorometry is presented. The introduction of flow injection analysis brought better reproducibility and avoided the effect of oxygen and other substances in the environment on the reaction of ninhydrin with hydroxyl radicals. Under optimum experimental conditions, the hydroxylated product of ninhydrin had excitation and emission maxima at 300 and 406 nm, respectively. The linear range was 2.60 x 10(-7) to 4.00 x 10(-5) M, and the limit of detection was 7.91 x 10(-8) M. A high analysis rate of 22 samples per hour was obtained. The proposed method has been applied successfully to the determination of scavenging effects of thiourea and vitamin C on hydroxyl radicals as well as to the evaluation of antioxidant capacities of some natural food.

Cobalt↗

[Laparoscopic-assisted radical gastrectomy: a report of 105 cases].

OBJECTIVE: To investigate the feasibility and safety of laparoscopic-assisted radical gastrectomy for gastric cancer. METHODS: One hundred and five patients with gastric cancer received laparoscopic-assisted radical gastrectomy, radical total gastrectomy were performed in 7 cases, proximal gastrectomy in 27 cases, proximal gastrectomy combined with splenectomy in 3 cases and distal gastrectomy in 68 cases. RESULTS: One hundred and five cases had laparoscopic-assisted radical gastrectomy successfully. The mean operation time was 381 +/- 91 (300 - 435) min for total gastrectomy, 279 +/- 73 (212 - 390) min for proximal gastrectomy, 312 +/- 64 (265 - 405) min for proximal gastrectomy combined with splenectomy, 281 +/- 69 (230 - 360) min for distal gastrectomy, respectively. The mean blood loss was 260 +/- 202 (20 - 900) ml in total gastrectomy, 200 +/- 153 (20 - 400) ml in proximal gastrectomy, 333 +/- 116 (200 - 400) ml in proximal gastrectomy combined with splenectomy, 140 +/- 82 (20 - 450) ml in distal gastrectomy, respectively. The mean number of harvested lymph nodes was 34.2 +/- 20.5 (8 - 83). The mean time for gastrointestinal function recovery was 3.5 +/- 1.4 (2 - 5) days, 3.0 +/- 1.6 (2 - 6) days for patients' taking normal activity, 4.9 +/- 1.7 (3 - 7) days for taking liquid food. The short-term efficiency was obvious. CONCLUSIONS: Laparoscopic-assisted radical gastrectomy is a feasible and safe surgical procedure combined with minimal trauma and fast recovery.

Adult↗

One-dimensional hierarchical layered KxMnO2 (x < 0.3) nanoarchitectures: synthesis, characterization, and their magnetic properties.

One-dimensional (1D) hierarchical nanostructures of ultralong layered K(x)MnO(2) (x < 0.3) bundles with diameters 50-100 nm and lengths up to 50-100 microm have been successfully prepared by a PEG-assisted hydrothermal method based on the reaction of KMnO(4) with 2-ethylhexanol. The obtained samples ascribe to the monoclinic phase and exhibit ferromagnetic behaviors below 32 K and paramagnetic behaviors above 32 K, which may make this system a promising base material for magnetic devices. A series of contrastive experiments have illustrated that 2-ethylhexanol, PEG 400, KOH, and reaction time play an important role in the synthesis of the nanobundles. A possible growth mechanism has been proposed.

Magnetics↗

Facile route to alpha-FeOOH and alpha-Fe2O3 nanorods and magnetic property of alpha-Fe2O3 nanorods.

alpha-FeOOH nanorods with diameters of 15-25 nm and lengths up to 170-300 nm were synthesized in high yield via a facile and template-free hydrothermal method at low temperature. After calcining the as-synthesized alpha-FeOOH at 250 degrees C for 2 h, we could obtain alpha-Fe2O3 nanorods. Interestingly, the as-obtained alpha-Fe2O3 nanorods exhibited weakly ferromagnetic characteristics at low temperature and superparamagnetic property at room temperature, which is different from the behavior of the corresponding bulk material.

Journal Article↗

Synthesis of ethylenediamine linked beta-cyclodextrin dimer and its analytical application for tranilast determination by spectrofluorimetry.

A synthesis of beta-cyclodextrin (beta-CD) dimer, containing two beta-CD moieties that are linked through their sides by ethylenediamine, was presented. The dimer was characterized by means of IR, (1)H NMR, (13)C NMR, and elemental analysis. The inclusion complexation behavior of beta-cyclodextrin dimer with tranilast was studied in an aqueous KH(2)PO(4)-citric acid buffer solution of pH 2.00 at room temperature by spectrofluorimetry. Based on the significant enhancement of fluorescence intensity of tranilast, a spectrofluorimetric method with high sensitivity and selectivity was developed for the determination of tranilast in bulk aqueous solution in the presence of ethylenediamine beta-CD dimer. The apparent association constant of the complex was 8.39 x 10(3) L mol(-1), and the linear range was 10.8-1.40 x 10(4) ng mL(-1) with the detection limit 3.2 ng mL(-1). There was no interference from the excipients normally used in tablets and serum constituents. The proposed method was successfully applied to the determination of tranilast in serum.

Carbon Isotopes↗

Determination of trace platinum by supramolecular catalytic kinetic spectrofluorimetry of beta-cyclodextrin-platinum-KBrO3-salicylaldehyde furfuralhydrazone.

A supramolecular catalytic kinetic spectrofluorimetric method was developed for the determination of platinum(IV) and the possible mechanism of catalytic reaction was discussed. The method was based on the fluorescence-enhancing reaction of salicylaldehyde furfuralhydrazone (SAFH) with potassium bromate, which was catalysed by platinum(IV) in a water-ethanol medium. beta-Cyclodextrin (beta-CD) obviously sensitized the determination at pH 5.20 and 25 degrees C. Under optimum conditions, the beta-CD-platinum-KBrO3-SAFH supramolecular kinetic catalytic reaction system had excitation and emission maxima at 372 and 461 nm, respectively. The linear range of this method was 0.60-180 ng ml-1 with a relative standard deviation of 1.2%, and the detection limit was 0.18 ng ml-1. Investigation of the mechanism and the effects of interferences is presented. The proposed method was applied successfully to determine trace platinum(IV) in the chemotherapeutic drug cisplatin and serum from patients with satisfactory results.

Journal Article↗

Molecular characterization of an arthritogenic collagen peptide interacting with I-Ar.

Collagen-induced arthritis (CIA) is an autoimmune arthritis that can be elicited by the immunization of genetically susceptible strains of mice with type II collagen (CII). We have analysed the molecular interactions that occur between an arthritogenic T-cell determinant CII (442-457) and the murine class II susceptibility allele I-A(r). To determine which amino acid residues within the CII (442-457) sequence are responsible for binding to I-A(r), a soluble I-A(r):IgG2aFc fusion protein-peptide binding assay was developed. Various concentrations of analogue peptides were tested for their ability to compete with biotinylated CII (607-622) for binding to I-A(r), thereby establishing a relative comparison of the binding affinities among these analogues. Analogue peptides with substitutions at positions 447 (Ala --> Val), 448 (Gly --> Ala) and 451 (Gly --> Ala) bound poorly to the I-A(r) molecule. These data suggest that positions 447, 448 and 451 on CII are the major anchor points to I-A(r) molecules. In cytokine assays, only substitutions within positions 445-454 decreased the interferon-gamma production by T cells. These data narrow the core of the arthritogenic T-cell determinant to CII (445-454). Identification of the molecular interactions involved in T-cell recognition of CII should lead to antigen-specific means of inhibiting autoimmune arthritis.

Animals↗

Maternally derived recombinant human anti-hantavirus monoclonal antibodies are transferred to mouse offspring during lactation and neutralize virus in vitro.

Transgenic mice expressing a recombinant human monoclonal antibody (rHMAb) against hantavirus were generated. These mice could be used as models to explore the possibilities of producing rHMAbs for therapeutic purposes. The highest concentration of the rHMAb in the milk of the transgenic females was 6.6 mg/ml. The rHMAb was also detected in the sera of pups fed by the transgenic females. Both the rHMAbs in the milk of transgenic mice and those in the sera of suckling pups were found to be active against hantaviruses, although the light chain of the antibody absorbed by the pups was modified by N-linked glycosylation.

Animals↗

Analog peptides of type II collagen can suppress arthritis in HLA-DR4 (DRB1*0401) transgenic mice.

Rheumatoid arthritis (RA) is an autoimmune disease associated with the recognition of self proteins secluded in diarthrodial joints. We have previously established that mice transgenic for the human DR genes associated with RA are susceptible to collagen-induced arthritis (CIA) and we have identified a determinant of type II collagen (CII(263-270)) that triggers T-cell immune responses in these mice. We have also determined that an analog of CII(263-270) would suppress disease in DR1 transgenic mice. Because the immunodominant determinant is the same for both DR1 transgenic and DR4 transgenic mice, we attempted to determine whether the analog peptide that was suppressive in DR1 transgenic mice would also be effective in suppressing CIA in DR4 transgenic mice. We treated DR4 transgenic mice with two analog peptides of CII that contained substitutions in the core of the immunodominant determinant: CII(256-276) (F263N, E266D) and CII(256-270) (F263N, E266A). Mice were observed for CIA, and T-cell proliferative responses were determined. Either peptide administered at the time of immunization with CII significantly downregulated arthritis. Binding studies demonstrated that replacement of the phenylalanine residue in position 263 of the CII peptide with asparagine significantly decreased the affinity of the peptide for the DR4 molecule. In contrast, replacement of the glutamic acid residue in position 266 with aspartic acid or with alanine had differing results. Aspartic acid reduced the affinity (35-fold) whereas alanine did not. Both peptides were capable of suppressing CIA. With the use of either peptide, CII(256-276) (F263N, E266D) or CII(256-270) (F263N, E266A), the modulation of CIA was associated with an increase in T-cell secretion of IL-4 together with a decrease in IFN-gamma. We have identified two analog peptides that are potent suppressors of CIA in DR4 transgenic mice. These experiments represent the first description of an analog peptide of CII recognized by T cells in the context of HLA-DR4 that can suppress autoimmune arthritis.

Amino Acid Substitution↗

[Transcription regulation of 5-Aza-2'-deoxycytidine on maspin gene demethylation in RKO human colorectal cell line].

OBJECTIVE: To detect the methylation status of 5'CpG island in the core promotor of maspin gene in RKO human colorectal cell line,and to explore the transcription regulation of DNA 5'CpG island demethylation on maspin tumor suppressor gene and its effect on the growth of cancer cell. METHODS: The status of 5 'CpG island methylation of maspin gene in RKO human colorectal cell line was analyzed using methylation specific polymerase chain reaction (MSP). After treated with a specific demethylating agent, 5-Aza-2'-deoxycytidine, reverse transcription polymerase chain reaction (RT- PCR) was used to examine maspin gene expression. Cell proliferation was evaluated using MTT assay,distribution of cell cycle and rate of apoptosis were determined using flow cytometry. RESULTS: The 5'CpG island methylation in the core promotor of maspin gene was detected in RKO human colorectal cell line. After treatment with three different concentration of 5-aza-2'-deoxycytidine, the expression of maspin mRNA increased 10.89, 16.91, 23.97 times respectively. MTT array showed the proliferation activity of RKO cell line was obviously reduced after 5-aza-2'-deoxycytidine treatment. The cells were arrested in G(0)/G(1) phase,and the apoptosis rates were 5.17%, 8.71% and 11.23% respectively compared with control group. CONCLUSION: The 5'CpG island methylation is probably responsible for maspin expression silencing in RKO human colorectal cell line, 5-aza-2'-deoxycytidine may effectively cause demethylation and inhibit the growth of tumor cell by reactivating the gene transcription silenced by aberrant hypermethylation.

Azacitidine↗

[The synergistic inhibitory effect of 5-aza-2-deoxycytidine and Tamoxifen on estrogen receptor alpha negative breast cancer cell lines in vitro].

OBJECTIVE: To observe if ER alpha gene can be induced by 5-aza-CdR in ER alpha negative human breast cancer cell lines (MDA-MB-231 and MDA-MB-435) and the synergistic inhibitory effects of 5-aza-CdR and Tamoxifen on these two cell lines in vitro. METHODS: The status of 5'CpG island methylation of ER alpha gene in ER alpha negative (MDA-MB-231 and MDA-MB-435) human breast cancer cell lines and 20 cases of breast cancer tissue was studied by MSP, the expression of ER alpha mRNA was inspected by using RT-PCR after these two cell lines were treated with 5-aza-CdR. Cell proliferation was evaluated by MTT assay, distribution of cell cycle and rate of apoptosis were determined by flow cytometry after these two cell lines were treated with 5-aza-CdR or TAM alone, or in combination in vitro. RESULTS: The 5'CpG island is methylated in the core promotor of ER alpha gene in ER alpha negative (MDA-MB-231 and MDA-MB-435) human breast cancer cell lines and the methylating rate is 25.0%, 66.7%, 83.3%, 100% in 20 cases of breast cancer tissue of stage I, II, III, IV, respectively. The expression of ER alpha mRNA was induced in these two cell lines after treated with 5-aza-CdR, MTT array showed the proliferation activity of these two cell lines was obviously reduced in 5-aza-CdR group and the inhibitory effect on proliferation was enhanced when 5-aza-CdR combined with TAM compared with control group, the induction of apoptosis was 11.20% and 8.71% respectively by 5-aza-CdR, while the rate of apoptosis is 48.8% and 53.1% when these two cells were treated with 5-aza-CdR combined with TAM. CONCLUSIONS: 5-aza-CdR can re-express ER alpha by demethylating and sensitive ER alpha negative human breast cancer cell lines to TAM, 5-aza-CdR and TAM synergistically inhibit proliferation and induce apoptosis in ER alpha negative human breast cancer cell lines, thus offer a new way for the treatment of ER alpha negative breast cancer.

Adult↗

Study on the supramolecular interaction of thiabendazole and beta-cyclodextrin by spectrophotometry and its analytical application.

The beta-cyclodextrin-thiabendazole (beta-CD-TBZ) inclusion complex was synthesized and its structure characterized by (1)H NMR and IR. The mechanism of the supramolecular interaction of TBZ and beta-CD has been studied and discussed by spectrophotometry. The results showed that the phenyl ring of TBZ was included in the beta-CD cavity to form a 1:1 host-guest complex with an apparent formation constant of 1.60 x 10(3) mol(-1).L. On the basis of the enhancement of the absorbance of TBZ produced through complex formation, a spectrophotometric method for the determination of TBZ in bulk aqueous solution in the presence of beta-CD was developed. The linear relationship between the absorbance and TBZ concentration was obtained in the range of 8.86 x 10(-7)-1.45 x 10(-5) mol/L. The detection limit was 2.71 x 10(-7)mol/L, and the relative standard deviation was 0.86%. The interference of 48 coexisting substances was slight. The proposed method has been successfully applied to the determination of TBZ in fruits with recoveries of 96-103%.

Buffers↗

Studies on the oxidation reaction of tyrosine (Tyr) with H2O2 catalyzed by horseradish peroxidase (HRP) in alcohol-water medium by spectrofluorimetry and differential spectrophotometry.

An oxidation reaction of tyrosine (Tyr) with H(2)O(2) catalyzed by horseradish peroxidase (HRP) was studied by spectrofluorimetry and differential spectrophotometry in the alcohol(methanol, ethanol, 1-propanol and isopropanol)-water mutual solubility system. Compared with the enzymatic-catalyzed reaction in the water medium, the fluorescence intensities of the product weakened, even extinguished. Because the addition of alcohols made the conformation of HRP change, the catalytic reaction shifted to the side of polymerization and the polymer (A(n)H(2), n>or=3) exhibited no fluorescence. The four alcohols cannot deactivate HRP. Moreover isopropanol activated HRP remarkably.

Alcohols↗