Biomedical subjects

Xiang Huang

Publications and source records attributed to Xiang Huang.

At least 19 recordsLinked to original sources

PubMed2026

MET Exon 14 Skipping Mutation in NSCLC: From Genomic Discovery to Biomarker-Guided Therapeutic Innovation.

INTRODUCTION: Non-small cell lung cancer (NSCLC) is the most common type of lung cancer, and the MET exon 14 skipping mutation is a key oncogenic driver, which promotes tumor progression and provides a new direction for precision therapy. METHODS: A systematic search of English-language literature and clinical trial data related to the MET exon 14 skipping mutation from 2020-2025 was performed to summarize the role of the mutation and therapeutic advances. RESULTS: DNA-based next-generation sequencing (NGS), RNA-based NGS, and RT-qPCR were employed as the main detection methods. Preclinical models confirmed that mutations promote tumor progression by activating the RAS/MAPK pathway. Clinical trials have reported objective remission rates (ORR) of 46-68% for first-line treatment with MET inhibitors in NSCLC patients harboring MET exon 14 skipping mutations. DISCUSSION: MET exon 14 skipping mutation as a therapeutic target for NSCLC has made significant progress, and MET inhibitors are more advantageous than chemotherapy and immunotherapy, and have been recommended by national and international guidelines as a first-line treatment option. Additionally, NGS technology has the potential to dynamically monitor tumor evolution and drugresistant mutations, thereby helping to realize precision medicine. CONCLUSION: The MET exon 14 skipping mutation is an important target for the precision treatment of NSCLC, and MET-TKIs have remarkable efficacy but a prominent problem with drug resistance. The construction of a precision medicine system encompassing diagnosis, treatment, and drug resistance management through multi-omics research, technological innovation, and international collaboration is a key direction for improving prognosis.

Humans↗

PubMed2006

[Study on small intestinal submucosa as repair materials in urethral reconstruction].

OBJECTIVE: To explore the possibility of small intestinal submucosa (SIS) for reconstruction of urethral defect. METHODS: Twenty-four male rabbits were divided into 4 groups: group A (the tubular SIS graft for urethral repair), group B (control group, urethral tubular defect), group C (the SIS patch graft for urethral repairs), group D (control group, urethral part defect). Then the regenerative segment was studied with histological technique by hematoxylin-eosin straining and immunohistological straining for alpha-actin after 6 and 12 weeks postoperatively. The retrograde urethrography and urodynamics were used to evaluate the function of the regenerative urethra at 12 weeks after operation. RESULTS: In groups A and C, at 6 weeks after operation, the luminal surface of matrix was completely covered by urothelium, minimal SIS graft was observed in the extracellular matrix, new smooth-muscle cells was confirmed; however, more inflammatory cells were observed in the host-matrix anastomosis in group A than in group C. At 12 weeks postoperatively, the regenerative tissue was equivalent to the normal urethral tissue and SIS disappeared in group C, but some minimal SIS grafts were observed in group A. In groups B and D, urethral strictures and fibrous connective tissue were observed except 3 cases. The urethrography showed wide smooth urethral in group A and C, meanwhile urodynamic evaluation didn't demonstrate significant difference (P > 0.05) in the bladder volume and the maximum urethral pressure between preoperation and postoperation in group A or group C. CONCLUSION: SIS can be a useful material for urethral repair in rabbits, the SIS patch graft is superior to the tubular SIS graft in urethra reconstruction.

Acrylic Resins↗

PubMed2005

Human telomerase reverse transcriptase expression and its clinical significance in laryngeal squamous cell carcinoma.

CONCLUSIONS: Upregulation of hTERT mRNA plays an important role during the occurrence and development of laryngeal squamous cell carcinoma. Most hTERT mRNA in plasma from patients with laryngeal squamous cell carcinoma is derived from tumour cells; moreover, the determination of plasma hTERT mRNA contributes to tumour diagnosis and the observation of curative effect. OBJECTIVES: To establish a real-time fluorescent reverse transcriptase polymerase chain reaction (RT-PCR) and to quantitate the level of human telomerase reverse transcriptase (hTERT) mRNA in carcinoma tissue and plasma from patients with laryngeal squamous cell carcinoma. We also wished to evaluate the role that hTERT mRNA expression plays during the occurrence and development of laryngeal squamous cell carcinoma, to probe the correlation between the expression level and the clinical and pathological parameters and to investigate the value of the determination of plasma hTERT mRNA in tumour diagnosis and the observation of curative effect. MATERIAL AND METHODS: A real-time fluorescent RT-PCR and a Lightcycler PCR system were used to quantitate the expression level of hTERT mRNA. RESULTS: The expression levels of hTERT mRNA (NhTERT) from laryngeal squamous cell carcinoma tissue and corresponding adjacent non-cancerous tissue were 62.6 +/- 21.7 and 3.5 +/- 1.9, respectively. NhTERT was significantly elevated in laryngeal squamous cell carcinoma tissue, rising to 17.9-fold on average, but there was no significant correlation between NhTERT and either tumour location, differentiation degree, T grade or N grade. For healthy examinees, NhTERT in plasma was 1.3 +/- 0.9, compared to 13.1 +/- 9.4 and 9.3 +/- 5.8 in patients with laryngeal squamous cell carcinoma examined before and 2 days after surgery, respectively. Compared to healthy examinees, NhTERT in plasma from patients with laryngeal squamous cell carcinoma was significantly elevated; moreover, 2 days after surgery, NhTERT in plasma had decreased significantly in these patients.

Adult↗

PubMed2005

[Alteration of the auditory function and auditory nerve pathology in Guinea pigs with peripheral nerve demyelination].

OBJECTIVE: To study the auditory function and auditory nerve pathological changes of the experimental allergic neuritis (EAN) animal model in Guinea pigs. METHOD: To establish the animal model of EAN, heterologous myelin basic protein (MBP) of peripheral nerve was used to the immunize Guinea pigs. Serum anti-MBP-IgG levels, sciatic nerve conduction velocity (NCV), hearing thresholds and wave latencies, and pathological changes in auditory nerve, sciatic nerve and cochlea were observed. The immune lesions in inner ear were examined with immunohistochemistry. Auditory brainstem response (ABR) and compound action potential (CAP) were assayed weekly before and after immunization for a period of seven weeks. In the control group, antigen was replaced by the 0.9% saline. RESULT: Serum anti-MBP-IgG levels increased significantly in experimental group comparing with the control group (P < 0.01). Seiatic nerve conduction velocity decreased after immunization, as comparing with the control group (P < 0.01). Sciatic nerve and auditory nerve showed the existence of demyelination. There was significant increase of ABR and CAP thresholds and the latencies of wave I, III, V and N1 in experimental group when compared to the controls (P < 0.01), but no significant changes in inter-peak latencies of I-III, III-V were found( P > 0.05). In addition, there were 4 Guinea pigs (8 ears) in which only appeared lengthened wave latencies with normal hearing thresholds. Immunohistochemistry indicated that antibodies to inner ear from the MBP-sensitized animals distributed in cochlear nerve, neurofiber of inner ear and spiral ganglion cells. Cochlear scanning electron microscopy showed the pathology of inner hair cell with stereociliary disorder and cytoplasmic protrusions. CONCLUSION: The results suggest that auditory nerve demyelination are involved in this experimental allergic neuritis animal model and sciatic nerve demyelination as well, and the auditory abnormalities are elicited. This animal model seems to be a promising one of auditory dysfunction due to demyelination disorders.

Action Potentials↗

PubMed2005

[Molecular epidemiology of human caliciviruses diarrhea among infants and young children in Lanzhou from December 2001 to June 2004].

OBJECTIVE: To investigate the characteristics of human caliciviruses (HuCV) diarrhea among infants and young children with acute diarrhea in Lanzhou, Gansu Province, China by using molecular epidemiologic techniques. METHODS: Stool specimens were collected from both outpatients and inpatients with acute diarrhea in Lanzhou. Enzyme-linked immunosorbant assay (ELISA) was used to detect rotavirus antigen (RVA). Reverse transcription-polymerase chain reactions (RT-PCR) were used to detect HuCV in stool specimens of RV ELISA (-). RESULTS: Of the stool specimens collected from 515 cases in Lanzhou from December 2001 to June 2004, 264 were RVA ELISA (+) and 251 were RVA ELISA (-). Among all cases who were RVA ELISA (-), 25 (9.96%) were found positive for HuCV. HuCV was detected in 12 of 133 cases (9.02%) from December 2001 to November 2002, no genotyping was performed for these cases. From July 2003 to June 2004 13 of 118 cases (11.02%) were found positive for HuCV, of whom 11 cases had Norwalk-like virus GII (NLV GII) infection and 2 cases had Sapporo-like virus infection (one case had combined infection with astrovirus) and no NLV GI was found. HuCV infection mainly occurred in children under 2 years of age and no seasonal cluster was found. CONCLUSION: HuCV is one of the major etiological agents of viral diarrhea among infants and young children in Lanzhou. NLV GII maybe the predominant genotype.

Caliciviridae↗

PubMed2005

[Study on expression and relationship between proliferating cell nuclear antigen and p53 oncoprotein in nasopharyngeal carcinoma].

OBJECTIVE: To observe PCNA p53 gene expression and their relationship with clinicopathologic factors in primary nasopharyngeal carcinoma(NPC). METHOD: PCNA, p53 proteins were assayed with immunohistochemical technique. RESULT: The expression of p53 protein was 9.5% in chronic inflammation of nasopharyngeal epithelium(CINE), which was significantly lower than it in NPCs with 76.3% (P < 0.01). In NPCs. p53 gene expression was significantly correlated with cervical lymph node metastasis of NPCs (P < 0.01), The expression of p53 in stage II, III, lV (93.3%, 80.0% and 100% respectively) were significantly higher than that in stage I (40.0%) (P < 0.01), the expression of PCNA and p53 protein was highly correlated (P < 0.01). CONCLUSION: The expression of p53 is the useful factor in diagnosis of NPC, the overexpression of p53 is related with the stage and cervical lymph node metastasis of NPC. And PCNA PI may represent the proliferative state of NPC, all of them may play important roles in the pathogenesis of nasopharyngeal carcinoma.

Adolescent↗

PubMed2005

[The effect of gap blocker 1-heptanol on function and morphology of guinea pig cochlea].

OBJECTIVE: To investigate the role of gap junctions in hearing function of guinea pig in vivo. METHOD: Seven guinea pigs were inoculated with 1-heptanol into perilymphatic space after a small hole was drilled in the bony wall near tympanic scala of the base turn. Auditory brainstem response (ABR) was recorded before, 30 min, 60 min, 90 min 120 min after operation. Two hours after surgery, all the animals were killed and the ultrastructure of guinea cochlea was observed by making electron microscopy specimens. RESULT: The application of 1-heptanol into guinea pig cochlea resulted in large increase in ABR threshold, which showed 30 to 40 dB elevation in guinea pig. And 1-heptanol could destroy the gap conjunction structure between hair cells and Deiter's cells in guinea cochlea. CONCLUSION: The gap blocker 1-heptanol might significantly influence the guinea pig's hearing function, and the gap conjunction might play an important role in normal cochlear function and K+ recycle in inner ear of guinea pig.

Animals↗

PubMed2005

[Apoptosis and dynamic caspase-3 expression during the immune response of inner ear].

OBJECTIVE: To investigate whether apoptosis is involved in the pathogenesis of the immune response of inner ear, and relation between signal transportation of Caspase-3 and apoptosis. METHOD: Forty-five healthy, female white guinea pigs were employed in this study. Sensitized systematically with keyhole limpet hemocyanin (KLH), the KLH-immunized animals were inoculated with the same antigen, and the control animals were injected PBS through cochlea basal turn. All animals were sacrificed respectively at 1st, 3rd, 5th, 7th and 14th day after inner ear vaccination. The auditory brainstem response (ABR) was measured before the KLH injection to the inner ear and just before sacrificing the animal. Paraffin sections of cochleas from animals were stained using a TUNEL assay to identify inner ear cells undergoing apoptosis,and immunohistochemistry method was used to detect the expression of Caspase-3 in the inner ears. RESULT: After immunization, the ABR thresholds of the KLH-challenged ears were significantly elevated by comparing with the preimmunization (P < 0.05), but after injection, there was no significant difference in the ABR thresholds of the PBS-injected ears compared with preinjection. TUNEL-positive cells were found in the KLH immunized inner ears but no TUNEL-positive cells were observed in the control inner ears except for a few positive cells in the supporting cells, the stria vascularis cells and the spiral ganglion cells. The positive cells are the outer hair cells in Cortis organ, and the marginal cells in the stria vascularis and the neurons in the spiral ganglion. And, under morphological analysis by light microscope, these cells have the features characteristic of apoptosis. Apparent Caspase-3 immunoreactivity expression could be detected in Corti's organ, the lateral wall and the neurons of the spiral ganglion in the KLH-immunized inner ears from 5th day after inner ear vaccination, but no cells staining positive for Caspase-3 were found in the control inner ears. CONCLUSION: Apoptosis is induced by the immune response of inner ear; Caspase-3 cascade has important effect on the course of apoptosis.

Animals↗

PubMed2004

Apatite formation on the surface of wollastonite/tricalcium phosphate composite immersed in simulated body fluid.

Wollastonite/tricalcium phosphate composites were prepared and immersed in SBF for various periods to investigate the apatite-formation mechanism on their surfaces. Surface morphologies and composition before and after immersion were analyzed by SEM and EDS technologies. The concentration changes of calcium, silicon, and phosphorus in SBF due to the immersion of the samples were measured with inductively coupled plasma atomic emission spectroscopy, and the corresponding pH values in SBF were recorded. XRD and IR were used to examine the changes in crystalline phases and functional groups. It was found that, after immersion for 1 day, the samples were covered by pom-pom-like apatite granules, resulting from the dissolution of wollastonite and the simultaneous transformation of TCP. This quickly led to the subsequent precipitation of another apatite layer, which covered the earlier-formed surface completely. These results indicate that the wollastonite/tricalcium phosphate composite is a potential biomaterial candidate because of its high bioactivity and in situ porous structure.

Apatites↗

PubMed2004

[Distribution of calcitonin gene-related peptide in guinea pig cochlea].

OBJECTIVE: To observe the distribution of CGRP in guinea pig cochlea. METHOD: CGRP was labeled by immunostaning technique. Distribution of CGRP immunoreactivity was observed with light microscopy. RESULT: CGRP immunoreactivity was located in SGN, nerve fibers at osseous spiral lamina, stria vascularis, IHC, adjacent area of OHC and Deiters' cells. CONCLUSION: CGRP distributes extensively in guinea pig cochlea. CGRP may play an important role as neurotransmitter and/or neuromodulator to hearing function by modulating HC, supporting cells, SGN and other neurons along the process of auditory nerve. It may have effect on on cochlear blood flow, too.

Animals↗

PubMed2004

[Effect of urokinase plasminogen activator on injured facial nerve of rats].

OBJECTIVE: To observe the effect of uPA on nerve regeneration and the expression of fibronectin and laminin after the facial nerve were transected and anastomosed, and to explore the mechanism of uPA in the microenvironment of nerve regeneration. METHOD: Twenty four SD rats were randomly divided into two groups: uPA group and control group. Every rat's extracranial facial were transected and anastomosed. Then uPA were injected at the belly of rat subcutaneously for five days in uPA group, three times one day, 5000 U/kg one time. Equal volume saline were injected in control models at the same site and the same time. At 1, 7, 21, 42, 84 day of post-operation, the diameter, perimeter, myelin sheath area of fibers and the expression of fibronectin and laminin in early phase of post-operation were measured by using morphometry, immunochemistry and the image analysis. RESULT: After operation, myelin sheath area at 21, 42 day and diameter of new regenerated fiber at 42 day in uPA group were better than those in control group (P<0.05). The expression of fibronectin elevated gradually after operation, and it expressed more than that of control group at 14 and 21 day (P<0.05). The expression of laminin decreased after operation, then elevated with the progress of nerve regeneration and showed no significant difference between two groups. CONCLUSION: The uPA can promote the fibrin degradation and upregulate the fibronectin expression when applicating in rat model, which benefit to improve the microenvironment and enhance facial nerve regeneration.

Animals↗

PubMed2004

[Apoptosis in the immune response of inner ear].

OBJECTIVE: To investigate whether apoptosis is one of the mechanism in the immune response of inner ear,and to detect the expression of Fas, FasL, Bcl-2 and Bax in the inner ears. METHODS: Sixteen healthy, female guinea pigs were employed in the experiment. Sensitized systematically with keyhole limpet hemocyanin (KLH), the KLH-immunized animals were inoculated with the same antigen, and the control animals were injected PBS through cochlea basal turn. The animals were sacrificed at 7 day after inner ear vaccination. Transmission electron microscopy was used to detect inner ear apoptotic cells, and paraffin sections of cochlea from animals were stained using a terminal-deoxynucleotidyl transferase mediated dUTP nick end labeling (TUNEL) assay to identify inner ear cells undergoing apoptosis. Immunohistochemistry method was used to detect the expression of Fas, FasL, Bcl-2 and Bax in the inner ears. RESULTS: The observation of electron microscopy had shown the features characteristic of apoptotic cells in the KLH-immunized inner ears but not in the control inner ears. TUNEL-positive cells were found in the KLH-immunized inner ears but not in the control inner ears. The positive cells were the hair cells in Corti's organ, and the marginal cells in the stria vascularis and the neurons in the spiral ganglion. Moreover under morphological analysis by light microscope, these cells had the features characteristic of apoptosis. High expression of Fas and FasL could be detected in Corti's organ, the stria vascularis, the spiral ligament and the neurons of the spiral ganglion in the KLH-immunized inner ears. A low expression of Fas could be detected in the stria vascularis and the neurons of the spiral ganglion in the control inner ears, but no cells staining positive for FasL were found in the control inner ears. No cells staining positive for Bcl-2 were found in the KLH-immunized animals but moderate expression of Bcl-2 could be detected in Corti's organ, the lateral wall and the neurons of the spiral ganglion in the control inner ears. High expression of Bax could be detected in Corti's organ, the lateral wall and the neurons of the spiral ganglion in the KLH-immunized inner ears. A low expression of Bax could be detected in the neurons of the spiral ganglion and no cells staining positive for Bax were found in Corti's organ, the lateral wall in the control inner ears. CONCLUSIONS: These findings suggest apoptosis is involved in the pathogenesis of the immune response of inner ear and Fas- FasL pathway is one of important signal transportation of the course and Bcl-2 and Bax have a critical role in the regulation of apoptotic cell death induced by the immune response of inner ear.

Animals↗

PubMed2003

Circadian telomerase activity and DNA synthesis for timing peptide administration.

DNA synthesis and telomerase activity were assessed in nude mice transplanted with hepatic carcinoma. Hepatic cancer cells (SMMC-7721) were implanted into both flanks of each of 14 BALB/C mice synchronized in 12 h of light alternating with 12 h of darkness (LD12:12) for 4 weeks. At 7 timepoints, tumor samples were collected for measurement of cellular DNA content by flow cytometry and telomerase activity by PCR-ELISA assay. Cosinor analyses determine a 24-h rhythm for all variables, showing a similar timing for the DNA-synthesis phase and telomerase activity. These results provide a model for exploring optimal timing of chronotherapy with peptides, especially for treatment with telomerase inhibitors.

Animals↗

PubMed2003

Cell proliferation in the endolymphatic sac in situ after the rat Waldeyer ring equivalent immunostimulation.

OBJECTIVES/HYPOTHESIS: It has been recognized that immunological mechanisms could be involved in the pathogenesis of different inner ear disorders, such as progressive sensorineural hearing loss, Meniere's disease, and even sudden deafness. The endolymphatic sac acts as an immune control organ for the inner ear and has been considered as an effector site of the mucosa-associated lymphoid tissue. The purpose of the study was to determine the potentially immunological relationship between endolymphatic sac and Waldeyer ring equivalent, one of the most important affector organs in mucosa-associated lymphoid tissue. STUDY DESIGN: Animal model. METHODS: Thirty-six rats were employed. Two animals were killed for histological observation of Waldeyer ring equivalent, and another 34 animals were randomly divided into experimental and control groups and received bilateral intranasal immunizations with keyhole limpet hemocyanin or Freund adjuvant, respectively. The ears of immunized animals and control animals were examined for keyhole limpet hemocyanin-positive memory cells and immunoglobulin G-positive plasma cells with the technique of immunohistochemical analysis. The histopathological changes and cell proliferation in those ears were also assessed. RESULTS: There were paired and organized lymphoid tissues in the lateral wall of the first choana in the rat. Keyhole limpet hemocyanin-positive lymphocytes appeared within the endolymphatic sac at 3 days after the first anti-genetic stimulus of the Waldeyer ring equivalent. Endolymphatic hydrops in the cochlea, elevated amounts of immunocompetent cells, and increased activity of cell proliferation within the endolymphatic sac were also considered after four intranasal injections of keyhole limpet hemocyanin. CONCLUSION: Presumably, endolymphatic sac is supplied with immunocompetent cells from Waldeyer ring equivalent and has an ability of co-reaction with Waldeyer ring equivalent.

Animals↗

PubMed2003

[The expression of proliferating cell nuclear antigen and Bcl-2 oncoprotein in nasopharyngeal carcinoma].

OBJECTIVE: To observe PCNA, Bcl-2 gene expression and their relationship with clinicopathologic factors in primary nasopharyngeal carcinoma(NPC). METHOD: PCNA, Bcl-2 proteins were assayed with immunohistochemical technique. RESULT: The expression of Bcl-2 protein was 9.5% in chronic inflammation of nasopharyngeal epithelium(CINE), which was significantly lower than it in NPCs with 83.1% (P < 0.01). In NPCs, we could find PCNA and Bcl-2 expression were significantly negatively correlated with each other(rs = -0.41, P < 0.01). In our study, there was some correlation in the grade of PCNA proliferating index(PI) with the clinical stages or cervical lymph node metastasis of NPCs. CONCLUSION: PCNA PI may represent the proliferative state of NPC, Bcl-2 protein may be a better tumor marker of NPC, all of them may play important roles in the pathogenesis of nasopharyngeal carcinoma.

Adolescent↗

PubMed2003

[The dosage of SDS when extracting membranous labyrinth proteins].

OBJECTIVE: To determine the appropriate dosage of SDS when extracting membranous labyrinth proteins. METHOD: The yield of proteins extracted with various amounts of SDS were determined by BCA method, and the components of the extracted proteins were analyzed by SDS-PAGE. RESULT: The amount of proteins extracted with 0.1% SDS is less than that with 0.23%, 1% or 2% SDS, meanwhile it shows less bands than the other and the corresponding bands are stained weaker. 0.23% SDS is less efficiently than 1% and 2% SDS in solubilizing proteins. There is no significant difference between 2% and 1% SDS in yield of proteins, while 2% SDS accompanies a higher ratio of detergent to protein. CONCLUSION: 1% SDS is solutions is relatively suitable for extracting membranous labyrinth proteins extensively while the ratio of detergent to protein is from 5 to 6.

Animals↗

PubMed2003

[Effect of human telomerase reverse transcriptase mRNA introduction on the growth of human umbilicus vein endothelial cell].

OBJECTIVE: To elongate the proliferation life-span of human umbilicus vein endothelial cell (HUVEC). METHODS: We synthesized the human telomerase reverse transcriptase mRNA (hTERT mRNA) by in vitro transcription, then transferred the hTERT mRNA into HUVEC in quicent stage by lipofect introduction. RESULTS: Telomerase expressed transiently in HUVEC, and the cell life-span was elongated for 7 population doublings. CONCLUSION: Telomerase can be reconstructed controllably and transiently in HUVEC by hTERT mRNA introduction, this method has the potential to be used to elongate the lifespan of cells cultured in vitro.

Cell Division↗

PubMed2003

[Detection of collagenase activity and tissue inhibitor of metalloproteinase-1 expression level in the urethral scar tissue].

OBJECTIVE: To find the difference between the collagenase activity and tissue inhibitor of metalloproteinase-1 (TIMP-1) expression level in normal urethral tissue and in urethral scar tissue, and to study the effect of collagenase activity and TIMP-1 expression level on the degradation of urethral scar. METHODS: The urethral tissues were derived from 10 human surgical specimens of urethral stricture scar and 10 human normal urethral specimens from patients with brain death. The collagenase activity was detected by ELISA assay, and the TIMP-1 mRNA level by RTPCR. RESULTS: The collagenase activity of urethral scar tissue was (15.32 +/- 2.29) U and lower than that of normal urethral tissue (24.67 +/- 6.78) U, there was significant difference between them (P < 0.01). The TIMP-1 expression level of urethral scar tissue was higher than that of normal urethral tissue, there was significant difference between them (P < 0.05). CONCLUSION: The high level of TIMP-1 expression and the low collagenase activity in urethral scar tissue may inhibit the degradation of urethral scar, and may be one of important causes of the scar tissue hyperplasia.

Adult↗