Biomedical subjects
Publications and source records attributed to Hao Tang.
Aureobasidium pullulans Y2311-1 is a yeast-like fungus that can produce poly(β-L-malic acid). Here, we report the draft whole-genome sequence of the A. pullulans Y2311-1 strain, which includes 14 scaffolds (ranging in size from 0.02 to 3.52 Mb, 25.41 Mb total, 50.09% GC).
Programmable gene knock-in holds substantial promise for treating genetic diseases and advancing cell therapies. However, achieving precise and efficient kilobase-scale DNA fragment integration remains challenging1,2. Here we report CRISPR kilobase-scale nickase-targeting (KNIT) editing for efficient, precise and programmable kilobase-scale DNA insertion without double-strand DNA cleavage, which is enabled through the coupling of a Cas9 nickase with a DNA donor recruiting system. KNIT editing facilitates programmable integration of DNA fragments from 0.7 kb to more than 10 kb and is effective across genomic loci and cell types. It achieves up to 89% efficiency and markedly reduces unintended insertion-deletion mutation (indels) rates, translocations and off-target editing. The system supports repeated insertion editing and multiloci gene knock-in with minimal translocations. Its enhanced version, KNIT editor 2, further improves efficiency via a single transfection. Moreover, in mutant cells with a pathological mutation, KNIT editing restores normal gene expression by inserting a therapeutic gene into a safe harbour locus or its native locus. Notably, KNIT editing enables non-viral and programmable chimeric antigen receptor T cell (CAR-T cell) engineering without double-strand breaks and with clinically relevant efficiencies. Moreover, the engineered CAR-T cells exhibit effective antitumour activity in vitro and in mouse models. Therefore, by achieving programmable and site-specific kilobase-scale DNA insertions without double-strand breaks while reducing unintended outcomes, KNIT editing provides a versatile platform for advancing personalized medicine.
Aging is the main determinant of chronic diseases and mortality, yet organ-specific aging trajectories vary, and the molecular basis underlying this heterogeneity remains unclear. To elucidate this, we integrated genomic, epigenomic, transcriptomic, proteomic, and metabolomic data, employing post-genome-wide association study methodologies to systematically investigate the molecular mechanisms of nine organ-specific aging clocks and four blood-based epigenetic clocks. We uncovered genetic correlations and specific phenotypic clusters among these aging-related traits, identified prioritized genetic drug targets for heterogeneous aging, and elucidated downstream proteomic and metabolomic effects mediated by heterogeneous aging. We constructed a cross-layer molecular interaction network of heterogeneous aging across multiple organ systems and characterized detectable biomarkers of this heterogeneity. Integrating these findings, we developed an R/Shiny-based framework that provides a comprehensive multi-omic molecular landscape of heterogeneous aging, thereby advancing the understanding of aging heterogeneity and informing precision medicine strategies to delay organ-specific aging and prevent or treat its associated chronic diseases.
PURPOSE: Therapeutic efficacy, suitable dose, and administration times of 131I-CAb1 F(ab')2, a new monoclonal antibody therapeutics specifically directed against a cell surface-associated glycoprotein of colon cancer, were investigated in this article. METHODS AND MATERIALS: In human colon cancer xenografts, 131I-CAb1 F(ab')2 at the dose of 125 muCi, 375 muCi, and 1125 muCi were administrated intraperitoneally on Days 6 and 18 after implantation of HR8348 cells with CAb1 high reactivity. Survival time and tumor growth inhibition rate were used to evaluate the efficacy and safety of 131I-CAb1 F(ab')2 in treatment of colon cancer xenografts. RESULTS: Treatment of 125, 375, and 1125 muCi 131I-CAb1 F(ab')2 did not significantly decrease the mean survival time of nude mice when compared with nontreated groups (p = 0.276, 0.865, 0.582, respectively). Moreover, the mean survival times of nude mice receiving 375 muCi and 1125 muCi 131I-CAb1 F(ab')2 were significantly longer than that of 5-FU-treated groups (p = 0.018 and 0.042). Tumor growth inhibition rates of the first therapy were 35.67% and 41.37%, with corresponding 131I-labeled antibody dosage of 375 muCi and 1125 muCi. After single attack dosage, second reinforcement therapy may rise efficacy significantly. Tumor growth inhibition rates of 125 muCi, 375 muCi, and 1125 muCi 131I-labeled antibody on Day 20 posttherapy were 42.65%, 56.56%, and 84.41%, respectively. Histopathology examination revealed that tissue necrosis of various degrees was found in 131I-CAb1 F(ab')2-treated groups. CONCLUSION: 131I-CAb1 F(ab')2 is safe and effective for colon cancer. It may be a novel and potentially adjuvant therapeutics for colon cancer.
A simple and sensitive label-free electrochemical immunoassay electrode for detection of carcinoembryonic antigen (CEA) has been developed. CEA antibody (CEAAb) was covalently attached on glutathione (GSH) monolayer-modified gold nanoparticle (AuNP) and the resulting CEAAb-AuNP bioconjugates were immobilized on Au electrode by electro-copolymerization with o-aminophenol (OAP). Electrochemical impedance spectroscopy and cyclic voltammetry studies demonstrate that the formation of CEA antibody-antigen complexes increases the electron transfer resistance of [Fe(CN)(6)](3-/4-) redox pair at the poly-OAP/CEAAb-AuNP/Au electrode. The use of CEA antibody-AuNP bioconjugates and poly-OAP film could enhance the sensitivity and anti-nonspecific binding of the resulting immunoassay electrode. The preliminary application of poly-OAP/CEAAb-AuNP/Au electrode for detection of CEA was also evaluated.
OBJECTIVE: To study apoptosis of peripheral blood mononuclear cells (PBMCs) in patients with multiple organ dysfunction syndrome (MODS) and its associated gene Bcl-2 and p53 expression. METHODS: Twenty-five patients with MODS and 18 healthy volunteers were enrolled for the study. Flow cytometry assay, electron microscopy, acridine orange-ethidium bromide staining and fluorescence microscopy, DNA agarose gel electrophoresis were used to identify and quantify apoptosis of PBMCs. Reverse transcription-polymerase chain reaction (RT-PCR) was used to quantify Bcl-2 mRNA and p53 mRNA expression. RESULTS: Typical morphological features of apoptotic PBMCs were observed in the patients. The apoptosis rate in MODS group was (25.4+/-9.2)%, and it was higher than that of control group (15.9+/-6.8)% (P<0.01). The number of apoptotic cells was (1.040+/-0.096)/high power field in MODS group, and it was higher than that in control group (0.235+/-0.028)/high power field (P<0.05). Bcl-2 mRNA expression of PBMCs in patients was significantly lower than that of healthy volunteers (0.11+/-0.09 vs. 0.19+/-0.06, P<0.05), while p53 mRNA expression was higher in patients than that of healthy volunteers (0.45+/-0.09 vs. 0.25+/-0.12, P<0.05). CONCLUSION: PBMCs apoptosis in patients with MODS is increased abnormally. The expression of Bcl-2 mRNA in patients is decreased while p53 mRNA expression is increased. The results suggest that abnormal apoptosis of monocytes as well as abnormal expression of apoptosis associated genes occur in patients with MODS.
OBJECTIVE: To investigate the association of surgical skills, anhepatic time and preoperative hepatic function grading with bacteria infection after the liver transplantation and identify the common bacterial flora involved for effective prevention and treatment of the posttransplant bacterial infection. METHODS;The clinical records of 31 cases of liver transplantation from August 2004 to August 2005 were reviewed and the collected data were analyzed statistically. RESULTS; Among the 31 cases, posttransplant bacterial infection occurred in 16 cases accounting for a total incidence of 51.61%, with the incidence of multi-system (or multi-organ) infection of 22.58%. The earlier cases had longer average surgery time and anhepatic period than the later cases, with also higher incidence of infection. Among the 19 patients with hepatic function class A before surgery, 7 acquired bacterial infection involving one system or organ, 2 had infections compromising multiple system or organ. In the 8 patients of hepatic function class B before surgery, 2 had single-system or -organ infection and 1 multi-system or -organ infection. Four out of the 5 patients with hepatic function class C before surgery acquired posttransplant bacterial infections, all involving multiple systems or organs. Pseudomonas aeruginosa was the most common bacteria responsible for the infections in these cases. CONCLUSION: Improvement of surgical skills can obviously reduce the incidence of bacterial infection after liver transplantation. No evidences suggest the correlation between the incidence of infections (including severe ones) and hepatic function class A or B before the operation, whereas patients with preoperative hepatic function class C seems to be at higher risk for infection involving multiple systems or organs. The anhepatic time does not significantly impact on the incidence or severity of the posttransplant infections, and Pseudomonas aeruginosa is the most common bacteria causing the infections.
OBJECTIVE: To ascertain whether mouse c-Kit(+)Lin- bone marrow cells have the potential of hepatic stem cells. METHODS: c-Kit(+)lin- bone marrow cells were isolated and purified by magnetic-activated cell sorting (MACS) from BALB/C male donor mice, and immediately transplanted into age-matched BALB/C syngeneic female mice with 35-Gy total liver irradiation. The recipients were sacrificed 1 month after the transplantation for pathological observation of the liver morphology. The presence of Y-chromosome was examined in the liver cells of the recipient by in situ hybridization (ISH), and alpha-fetoprotein (AFP) and albumin in the cells were detected by immunohistochemistry. RESULTS: The hepatocytes positive for Sry gene on Y-chromosome were identified 1 month after transplantation, and immunohistochemistry for AFP and albumin confirmed that the donor mice-derived cells were hepatocytes. CONCLUSION: c-Kit(+)lin- bone marrow cells have the potential of hepatic stem cells, which can reside and differentiate into hepatocytes in the liver after transplantation. c-Kit(+)lin- bone marrow cells can be used as the source cells of cell transplantation for liver disease.
OBJECTIVE: To study the role of cyclooxygenase (COX) and platelet-activating factor (PAF) in pathophysiologic mechanisms of patients with systemic inflammatory response syndrome (SIRS) and multiple organ dysfunction syndrome (MODS). METHODS: Twenty-eight adult patients whose diagnosis met American college of chest physicians/society of critical care medicine (ACCP/SCCM) criteria for SIRS and MODS were enrolled for study including 13 cases for SIRS group and 15 cases for MODS group. The normal control group consisted of 11 healthy volunteers who matched with study subjects for age and gender. Enzyme linked immunoadsorbent assay (ELISA) was used to measure the content of COX-2 and the activity of platelet-activating factor acetylhydrolase (PAF-AH) of peripheral blood mononuclear cells (PBMCs). Reverse transcription polymerase chain reaction (RT-PCR) was used to measure the COX-2 mRNA and PAF-AH mRNA expression of PBMCs. RESULTS: The content of COX-2 and the activity of PAF-AH of PBMCs and the expression of their mRNA in MODS group were higher than those in SIRS group and control group (all P<0.05). There was no significant difference between SIRS group and control group. The content of COX-2 and the activity of PAF-AH and the expression of their mRNA of PBMCs in non-survivors were higher than those in survived patients (all P<0.05). In 3 groups, positive correlation was found between the COX-2 content and PAF-AH activity (r=0.329, P<0.05). The leukocyte count, lymphocyte count, and PaO(2)/FiO(2) of peripheral blood in non-survivors showed no significant difference with those of survived patients (all P>0.05). The blood glucose and creatinine of non-survivors were higher than those of survived patients (P<0.05 and P<0.01). The total CO(2) content (TCO(2)) and pH value of non-survivors were lower than those of survived patients (both P<0.01). CONCLUSION: This study shows that COX-2 and PAF-AH play a role in the occurrence of MODS and they can be used as indexes to judge the prognosis of SIRS and MODS. Blood glucose, creatinine, TCO(2) and pH value of blood can be used as other indexes for judging the state and the prognosis of the illness.
A simple spirobifluorene molecule with pseudotetrahedral structure was investigated for its supposed conformational resilience upon adsorption. Through deposition at room temperature of this molecule on a Cu(111) surface and subsequent observation at 5 K with an ultrahigh vacuum scanning tunneling microscope, this "rigidity" upon physisorption is confirmed. However, an unexpected chemisorbed state was also found with the molecules arranged in trimers. The unique coexistence of physisorbed and chemisorbed states on the same substrate is thus demonstrated at the early stage of self-assembly.
The authors documented California's tobacco control initiatives for Asian Americans and the current tobacco use status among Asian subgroups and provide a discussion of the challenges ahead. The California Tobacco Control Program has employed a comprehensive approach to decrease tobacco use in Asian Americans, including ethnic-specific media campaigns, culturally competent interventions, and technical assistance and training networks. Surveillance of tobacco use among Asian Americans and the interpretation of the results have always been a challenge. Data from the 2001 The California Health Interview Survey (CHIS) were analyzed to provide smoking prevalence estimates for all Asian Americans and Asian-American subgroups, including Korean, Filipino, Japanese, South Asian, Chinese, and Vietnamese. Current smoking prevalence was analyzed by gender and by English proficiency level. Cigarette smoking prevalence among Asian males in general was almost three times of that among Asian females. Korean and Vietnamese males had higher cigarette smoking prevalence rates than males in other subgroups. Although Asian females in general had low smoking prevalence rates, significant differences were found among Asian subgroups, from 1.1% (Vietnamese) to 12.7% (Japanese). Asian men who had high English proficiency were less likely to be smokers than men with lower English proficiency. Asian women with high English proficiency were more likely to be smokers than women with lower English proficiency. Smoking prevalence rates among Asian Americans in California differed significantly on the basis of ethnicity, gender, and English proficiency. English proficiency seemed to have the effect of reducing smoking prevalence rates among Asian males but had just the opposite effect among Asian females.
Controlled-fed perfusion, a new operation mode, which combines the advantages of fed-batch and perfusion, has been reported to enhance monoclonal antibody productivity. The aim of the present study was to further enrich this mode by an "oxygen uptake rate-amino acids (OUR-AA)" strategy in which the feeding of amino acids was controlled according to the variation of OUR during perfusion. And the effects of this strategy on bioreactor productivity and product quality were evaluated. Experimental results indicated that by using this "OUR-AA" approach in controlled-fed perfusion mode a high viable cell density of more than 1.9 x 10(7)cells/ml was achieved and the productivity of mAb reached 325 mg/l/d, which was significantly increased by nearly twofold over those of the perfusion and fed-batch process. The residual concentrations of selected amino acids were controlled at a relative steady level by OUR during the culture. The immunoreactivity and the purity of the antibody were well preserved as the culture process was evolving from flask to the controlled-fed perfusion mode. The primary application of "OUR-AA" approach in controlled-fed perfusion mode may present a novel control strategy to enhance the culture performance and to display the potential of this approach in automatic control field.
To examine the significance of heat shock protein 70 mRNA in ototoxicity resulted from gentamicin (GM), twenty healthy albino guinea pigs (200-250 g) of either sex with a positive Prier reflex were divided into two groups randomly. In GM group the animals received 100 mg/kg GM daily by intraperitoneal injection for 10 d. In saline control group the animals received 2.5 ml/kg saline daily by intraperitoneal injection for 10 d. Auditory brainstem response (ABR) thresholds were recorded in each animal before and 1 d after GM or saline administration. After the second ABR measurement, the expression of HSP70 mRNA in guinea pig cochlea was observed with in situ hybridization and image quantitative analysis system. The results showed that the threshold of ABR in the GM group was significantly higher than that of the saline control (P< 0.001). The expression of HSP70 mRNA was more intensive in stria vascularis, spiral ligament and spiral ganglion cells in the GM group than that of the saline control group. These results suggest that administration of gentamicin can induce the expression of HSP 70 mRNA in guinea pig cochlea, and that this effect may protect hearing function from ototoxicity.
BACKGROUND: During infection and inflammation, circulating blood monocytes migrate from the intravascular compartments to the extravascular compartments, where they mature into tissue macrophages. The maturation process prepares the cells to actively participate in the inflammatory and immune responses, and many factors have been reported to be involved in the process. We found in our study that CD147 played a very important role in this process. RESULTS: By using PMA-differentiated human monocyte cells line THP-1, we found that CD147 mediated matrix metalloproteinases (MMPs) expression of the leukemic THP-1 cells and thus enhanced the invasiveness of THP-1 cells. After 24 hours of PMA-induced monocyte differentiation, the mean fluorescence intensity of CD147 in differentiated THP-1 cells (289.61 +/- 31.63) was higher than that of the undifferentiated THP-1 cells (205.1 +/- 19.25). There was a significant increase of the levels of proMMP-2, proMMP-9 and their activated forms in the differentiated THP-1 cells. Invasion assays using reconstituted basement membrane showed a good correlation between the invasiveness of THP-1 cells and the production of MMP-2 and MMP-9. The difference in the MMPs expression and the invasive ability was significantly blocked by HAb18G/CD147 antagonistic peptide AP-9. The inhibitory rate of the secretion of proMMP-9 in the undifferentiated THP-1 cells was 45.07%. The inhibitory rate of the secretion of proMMP-9, the activated MMP-9 and proMMP-2 in the differentiated THP-1 cells was 52.90%, 53.79% and 47.80%, respectively. The inhibitory rate of invasive potential in the undifferentiated cells and the differentiated THP-1 cells was 41.82 % and 25.15%, respectively. CONCLUSION: The results suggest that the expression of CD147 is upregulated during the differentiation of monocyte THP-1 cells to macrophage cells, and CD147 induces the secretion and activation of MMP-2 and MMP-9 and enhances the invasive ability of THP-1 cells. The matured monocytes / macrophages, via their high expression of CD147, may play an important role in promoting the tissue repair or tissue damage during their inflammatory response.
Mutations in human PRPF31 gene have been identified in patients with autosomal dominant retinitis pigmentosa (adRP). To begin to understand mechanisms by which defects in this general splicing factor cause retinal degeneration, we examined the relationship between PRPF31 and pre-mRNA splicing of photoreceptor-specific genes. We used a specific anti-PRPF31 antibody to immunoprecipitate splicing complexes from retinal cells and identified the transcript of rhodopsin gene (RHO) among RNA species associated with PRPF31-containing complexes. Mutant PRPF31 proteins significantly inhibited pre-mRNA splicing of intron 3 in RHO gene. In primary retinal cell cultures, expression of the mutant PRPF31 proteins reduced rhodopsin expression and caused apoptosis of rhodopsin-positive retinal cells. This primary retinal culture assay provides an in vitro model to study photoreceptor cell death caused by PRPF31 mutations. Our results demonstrate that mutations in PRPF31 gene affect RHO pre-mRNA splicing and reveal a link between PRPF31 and RHO, two major adRP genes.
BACKGROUND: Minimally invasive saphenous vein harvest (MIVH) techniques have been evaluated and reported with heterogeneous results. The aim of this study was to evaluate the efficacy of MIVH on the outcomes of postoperative leg wound healing and pain using the SaphLITE retractor system. METHODS: Two hundred twenty-five patients undergoing elective coronary artery bypass grafting surgery were randomized to receive either SaphLITE vein harvest (SVH) or conventional open vein harvest (OVH). RESULTS: There were no significant differences between the two groups in demographics, postoperative mortalities and major complications. For SVH group and OVH group, total leg wound length was 18.33 +/- 7.93 cm vs 46.10 +/- 15.63 cm (p < 0.001), and vein harvest time was 50.70 +/- 16.55 minutes vs 40.35 +/- 16.43 minutes (p < 0.001). In-hospital leg wound healing disturbance (LWHD) rate was 4.7% for SVH group and 1.7% for OVH group (p = 0.190). Delayed LWHD rate was 16.0% for SVH group and 39.5% for OVH group (p < 0.001). Combined, LWHD rate was 20.8% for SVH group and 41.2% for OVH group (p = 0.001). There was no significant difference in the worst postoperative leg wound pain or length of hospital stay between the 2 groups. Double-blinded histologic examinations revealed normal vascular structure in the harvested veins from both groups. CONCLUSIONS: Our study demonstrated that harvesting saphenous vein with SaphLITE retractor system is a good technique which is associated with reduced rate of delayed LWHD, preserved venous structural integrity, and acceptable harvest speed.
The metabolism of HAb18 hybridoma cells was shifted to decrease metabolite accumulation and to improve culture efficiency by integrated metabolic control of glucose and glutamine at low levels. When glucose and glutamine levels were decreased to 0.5 and 0.3 mM respectively, lactate and ammonia production were reduced by 62.6 and 74% respectively, glucose-to-cell yield was increased from 0.23x10(9) to 0.66x10(9) cells.mmol-1, and glutamine-to-cell yield from 0.18x10(9) to 1.95x10(9) cells.mmol-1. Compared with high-level glucose and glutamine fed-batch cultures, low-level glucose and glutamine led to higher cell density (1.0x10(7) versus 0.3x10(7) cells.ml-1), longer culture span (14 as opposed to 8 days) and higher antibody yield (250 as against 150 mg.l-1). These results indicate that hybridoma culture efficiency would be increased by the integrated control of glucose and glutamine at 0.5 and 0.3 mM respectively. In contrast with previously reported glucose-and/or-glutamine-level-controlled fed-batch cultures, we demonstrated an efficient strategy of nutrient level selection and amino acid feeding. More importantly, our accurately and well-distributed Equable Feeding Control System opens a new avenue for reducing metabolites to low levels by controlling nutrients at low levels.
OBJECTIVE: To investigate the pathogenesis of multiorgan injury and the protective of p38 mitogen activated protein kinase(p38MAPK) inhibitor on organs in sepsis. METHODS: Cecal ligation and puncture was adopted to reproduce sepsis model. The levels of serum biochemical parameters [including alanine aminotransferase (ALT), blood urea nitrogen(BUN), creatinine(Cr), MB isoenzyme of creatine phosphokinase (CPK-MB), tumor necrosis factor-alpha(TNF-alpha) and interleukin-1beta(IL-1beta) were determined at different time points. RESULTS: The levels of ALT, BUN, Cr, CPK-MB, TNF-alpha and IL-beta rose progressively after the cecal ligation operation. The levels of TNF-alpha and IL-1beta showed a significant correlation with levels of ALT, BUN, Cr, CPK-MB. After the administration of p38MAPK inhibitor, SB203580, the level of TNF-alpha and IL-1beta were found to decrease evidently, and the injury to multiple organs was alleviated. CONCLUSION: Excessive secretion of TNF-alpha and IL-beta may be the main cause of multiorgan injury in sepsis. Modulation of the p38MAPK pathway may protect multiorgan injury in sepsis.