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Biomedical subjects

Xu Yang

Publications and source records attributed to Xu Yang.

50 records · Page 3Linked to original sources
PubMed2004

[The clinical characteristic of electroglottography curves of pathological voice in adult].

OBJECTIVE: To discuss the clinical characteristic of Electroglottography (EGG) curves of pathological voice in adult. METHOD: Four hundred and fifty-three adults with pathological voices were examined by EGG and the abnormal EGG curves were analyzed. RESULT: (1) the EGG cycle was composed of contact phase (CP) and open phase (OP), the ratio of CP/OP was between 0.70 to 2.95, otherwise it was abnormal; (2) the CP was composed of closing-contact phase (CCP) and contact-opening phase (COP); the OP was composed of opening-open phase (OOP) and open-closing phase (OCP); (3) the abnormal formations of every phases in vibration cycle contained: smooth CCP, notches in CCP, flat in wave peak, steep COP, notches in COP, knurls in COP, knurls in OOP and in OCP; duplicate waves and irregular waves were fewer, but they reflected the special vibratory patterns of pathological voices; (5) Each abnormal formation fell as the follow: COP>OP>CCP. Each pathological voices presented different characteristics; (6) combined variance appeared in part pathological voices, such as single vocal polyps, double vocal polyps, Reinke edema and glottic laryngocarcinoma. COP combined with OOP was the most usual. CONCLUSION: The abnormal variance formations of EGG curves of pathological voices in adult are intricate and they have inherent relations with each other. The establishment of OP variance increases the pathological EGG and the OP abnormities is CP abnormities. There are different orientations and rules in different pathological voices.

Adult↗
PubMed2004

[Study on the formaldehyde-induced DNA damage with comet assay].

Formaldehyde is known as a genotoxic substance. Numerous studies have shown that formaldehyde could induce DNA-DNA and DNA-protein crosslinks. However, scholars have disagreed with each other on the formaldehyde-induced DNA strand breaks. We chose buccal cells as materials to evaluate the genotoxicity of formaldehyde with comet assay--especially for DNA strand breaks. The results showed that formaldehyde of low concentration induced DNA strand breaks, while formaldehyde of high concentration induced DNA-DNA and DNA-protein crosslinks. According to our experimental results, we proposed the concept of the "peak point of break" at which formaldehyde induced DNA strand breaks most.

Comet Assay↗
PubMed2004

[Treatment of delayed complex malhealed jaw fractures in 32 patients.].

PURPOSE: Three methods were used to manage delayed complex malhealed jaw fractures in 32 patients. The indication for each method and final result was evaluated. METHODS: Three methods included conservative therapy, internal fixation and orthognathic surgery. In conservative therapy, intermaxillary fixation was obtained with dental arch splints. In internal fixation, ordinary operation was performed including open exposure of the fractured segments, anatomical reposition and rigid fixation with steel wire or titanium miniplates. In some patients, orthognathic surgery was carried out with intermaxillary ligation for 2 to 3 weeks postoperatively. RESULTS: All the wounds healed primarily without significant complications. The postoperative occlusion and appearance were satisfactory or fair. CONCLUSIONS: The selection of treatment methods should be based on the location, time, severity of the fracture and the patients' age, in order to achieve maximal recovery of mastication and appearance.

Dental Occlusion↗
PubMed2003

Thalidomide blocking of particle-induced TNFalpha release in vitro.

Tumor necrosis factor-alpha (TNFalpha) and interleukin-6 (IL-6), pleiotropic cytokines with osteotropic activities, are produced by multiple cells in the skeletal tissue, including macrophages and osteoblasts. They are thought to be pivotally involved in pathological bone resorption, such as that seen with aseptic loosening. Thalidomide is reported to have antiinflammatory, immunomodulatory effects in a number of inflammatory diseases. We investigated the effect of thalidomide on titanium (Ti) particle-induced TNFalpha and IL-6 production by both human macrophage U937 and osteoblast MG-63 cell lines. They were stimulated with 1 x 10(7) Ti particles/ml and treated simultaneously with or without various concentrations of thalidomide (from 2.5 ng/ml to 25 microg/ml) for 24, 48, or 72 h. Cell viability and proliferation were measured. TNFalpha and IL-6 in the supernatant of the culture media were also analyzed with an enzyme-linked immunosorbent assay. We found that with a concentration of thalidomide of less than 2.5 microg/ml the viability of the two cell lines did not differ significantly from that of controls treated simultaneously with 1 x 10(7) Ti particles/ml. Cell proliferation was inhibited to some extent when they were treated with thalidomide 2.5 microg/ml co-cultured with 1 x 10(7) Ti particles/ml. Thalidomide treatment was found to inhibit TNFalpha production in a dose-dependent manner in human macrophages exposed to Ti particles. At the clinically achievable drug dose of 2.5 microg/ml, 34.4% TNFalpha inhibition occurs. Thalidomide had no effect on IL-6 secretion in these cultures. These data support the idea that thalidomide may have potential for treating prosthetic loosening in humans.

Cell Line↗
PubMed2003

A novel stop codon mutation in HBsAg gene identified in a hepatitis B virus strain associated with cryptogenic cirrhosis.

AIM: HBsAg is the most important serological marker for acute or chronic hepatitis B. Nevertheless, there were reports of HBsAg-negative infection caused by hepatitis B virus in recent years. We had a patient with crytogenic cirrhosis who was negative for HBsAg, positive for anti-HBs and HBeAg. This paper was to explore the pathogenic and molecular basis of the unusual serological pattern. METHODS: HBV serologic markers were qualitatively and quantitatively determined. HBV DNA in serum was qualitatively tested using routine Polymerase chain reaction(PCR), and the viral level was determined with real-time fluorescence quantitative PCR. HBsAg gene was amplified and cloned. Four clones were sequenced. The new genomic sequences were compared with GenBank on the DNA level as well as the protein level. RESULTS: The qualitative results of serological markers were HBsAg(-), anti-HBs(+), HBeAg(+), anti-HBe(-) and anti-HBc(+). The quantitative results of serological marker were HBsAg (S/N): 0.77 (cut off of S/N: >=2.00), HBeAg (S/N): 56.43 (cut off S/N: >=2.10), anti-HBc (S/C(0)): 2.03 (cut off of S/C(0): <=1.00). The viral level was as high as 1.54 x 10(9) copies/ml. Sequencing of the HBsAg gene clones revealed a unique point mutation at nucleotide 336 (C to A), which resulted in a novel stop codon at aa 61. The novel HBsAg gene stop mutation had not been described. CONCLUSION: The lack of detection of HBsAg in the presence of high viral levels of replication may be caused by the existence of viral genomes harboring point mutations which resulted in stop codon upstream of the "a" determinant in HBsAg gene.

Amino Acid Sequence↗
PubMed2003

Clinical and experimental study on therapeutic effect of umbilical cord blood transplantation on severe viral hepatitis.

AIM: To investigate the therapeutic effect of umbilical cord blood transplantation (UCBT) on patients with severe viral hepatitis and on liver lesions in rats. METHODS: One hundred and fifty three patients with severe viral hepatitis were included in the study between April 1990 and July 2002. The patients were treated with adult plasma transfusion (control), UCBT, plasma exchange (PE) and UCBT combined with PE (UCBT+PE) respectively. The therapeutic effectiveness was evaluated by serial determinations of liver function, lipids and immune function in all patients before and after the treatment. The model of experimental hepatic failure was constructed in SD rats by injecting carbon tetrachloride. Then, the rats were given normal saline, adult plasma or neonate cord blood intraperitoneally. After detection of liver function, the rats were killed and morphological changes of the liver were microscopically observed. RESULTS: UCBT group and UCBT+PE group had much better improvement in liver and immune functions than control group and PE group. The patients in UCBT+PE group had the best clinical efficacy. UCBT was safe and had no side effects. The animal experiment showed significant improvements in liver function and survival rate in neonate cord blood group as compared with adult plasma group. The histopathology of rat's liver indicated that neonate cord blood application could decrease the liver injury and increase hepatocellular regeneration. CONCLUSION: UCBT demonstrated a good therapeutic effect on severe viral hepatitis and no obvious side effects. Umbilical cord blood can attenuate the liver lesions and reproduce hepatocyte. The treatment of UCBT combined with PE was much better than that of single plasma exchange, thus UCBT can enhance the therapeutic effect of plasma exchange on severe viral hepatitis.

Adolescent↗
PubMed2002

[Short-term effect evaluation of health education on the prevention of AIDS among university students in Changsha].

OBJECTIVE: To survey the sexual sense and AIDS knowledge and to evaluate the instant effect of health education for university students in Changsha. METHODS: According to the KABP survey, 235 students in 2 universities in Changsha were investigated by anonymous questionnaires before and after the health education. The health education on sex and AIDS knowledge was carried out by a professor from an AIDS laboratory. Three hundred and eighty-eight pre- or post-educational questionnaires were analyzed and compared. RESULTS: Some of the students accepted such behaviors as unmarriage sexual act, multipartners, homosexuality, and commercial sexual act. These sexual senses were not instantly corrected by the health education. Most of the students investigated had some AIDS knowledge and the knowledge was improved instantly by the health education. CONCLUSION: There may be some high risk factors for AIDS transmission and venereal disease which may not be corrected by instant education among some university students in Changsha, whereas sexual hygiene and AIDS knowledge of most of the students investigated can be improved by a short-term education, which can be considered as a major form of health education.

Acquired Immunodeficiency Syndrome↗
PubMed2002

[A novel stop codon mutation in S gene: the molecular basis of a patient with cryptogenic cirrhosis].

OBJECTIVE: To explore the pathogen and molecular basis of cryptogenic cirrhosis in a patient. METHODS: Serum was collected from a patient, male, aged 56, with cryptogenic cirrhosis. HBV serologic markers were qualitatively tested, and HBsAg, HBeAg, and anti-HBc were quantitatively determined again. HBV DNA in serum was qualitatively tested using PCR, and quantified using fluorescence quantitative PCR. S gene was amplified, cloned, and sequenced. RESULTS: HbsAg and anti-Hbe were negative, and anti-HBs, HBeAg, anti-HBc, and HBV DNA were all positive. HBsAg (S/N) was 0.77 (cutoff of S/N: >/= 2.00), HbeAg (S/N) was 56.43 (cutoff of S/N: >/= 2.10), anti-HBc (S/C(O)) was 0.03 (cutoff of S/C(O): </= 1.00); HBV DNA was 1.54 x 10(9) copies/ml. An uncommon point mutation at nucleotide 336 (C to A) in S gene was found, resulting in the change of the 61st codon into a novel stop codon and failure of synthesis of HbsAg. CONCLUSION: HBV proves the pathogen of this case. This special mutation well explains the patient's unusual serologic pattern. Moreover, this finding possesses important clinical and theoretical significance.

Base Sequence↗
PubMed2002

Sclerosing extramedullary hematopoietic tumor.

A 73-year-old woman presented with abdominal pain, weakness, and weight loss. Pertinent medical history included myelofibrosis, severe anemia, and lumpectomy for breast cancer. Computed tomography showed marked splenomegaly and numerous soft tissue masses in the mesentery. Excisional biopsy of the mass showed an encapsulated tumor with yellow-tan nodular growth pattern. Microscopically, the tumor was characterized by the presence of bizarre giant cells in background of prominent dense fibrous stroma. The atypical giant cells were positive for FVIII antibody staining. Many other cells were positive for CD43 antibody staining, indicating that the tumor was hematopoietic in nature, so-called sclerosing extramedullary hematopoietic tumor. Extramedullary hematopoiesis is a common phenomenon associated with severe anemia of any cause. When associated with myelofibrosis, however, it has different morphology from extramedullary hematopoiesis of the other causes. The significance of recognizing sclerosing extramedullary hematopoietic tumor is that it is often mistaken for sarcomas and other malignant neoplasms, especially when the clinical history is unknown.

Aged↗
PubMed2002

Epithelioid angiomyolipoma of the ovary: a case report and literature review.

Angiomyolipoma (AML) is a benign mesenchymal neoplasm that mainly occurs in the kidney either sporadically or in patients with tuberous sclerosis complex (TSC). Extrarenal AML is uncommon. We describe a 39-year-old female with a history of TSC and bilateral multicentric renal AML who presented with a persistent cystic ovarian mass that fluctuated in size during 2 years of ultrasonographic observation before its removal by salpingo-oophorectomy. The 4.5-cm mass was solid and cystic and tan-yellow. Microscopic examination showed an admixture of epithelioid cells, smooth muscle bundles, large thick-walled blood vessels, and mature adipose tissue. The epithelioid cells had abundant eosinophilic cytoplasm and many had bizarre atypical nuclei including multinucleated forms. Mitoses were rare. Typical smooth muscle cells and the epithelioid cells were strongly immunoreactive for HMB-45. To our knowledge, this represents the first report of an AML arising in the ovary. The differential with other oxyphilic tumors of the ovary is discussed.

Adult↗
PubMed2002

[Relationship between the quantities of virus and the models of serologic markers in patients infected with HBV].

OBJECTIVE: To explore the relationship between the quantities of HBV and the models of serologic markers. METHODS: Real-time fluorescent quantitative PCR was used to measure the HBV DNA and ELISA was used to detect the antigen/antibody of HBV. RESULTS: The patients whose HBV copies were more than 10(3)/ml accounted for 87.3%, whose copies were more than 10(7)/ml accounted for 66.7% among the HBsAg and HBeAg -positive patients. The patients whose HBV copies were less than 10(3)/ml accounted for 74.5%, whose HBV copies were more than 10(7)/ml accounted for 8.3% among the HBeAg-negative patients. The HBV copies of HBeAg-positive patients were significantly more than HBeAg-negative patients (P<0.01). The HBV copies of anti-HBe-negative patients were significantly more than anti-HBe-positive patients (P<0.01). The HBV DNA was detected in some HBsAg-negative patients. One patient's HBV copies were as high as 1.59 10(9)/ml. CONCLUSIONS: The HBV copies of HBeAg-positive patients are significantly more than HBeAg-negative patients, The HBV copies of anti-HBe-negative patients are significantly more than the anti-HBe-positive patients. However, some HBeAg-positive patient's HBV copies are very low, and some HBeAg-negative patient's HBV copies are very high. HBV DNA even could be detected in some HBsAg-negative patients. It is difficult to judge accurately the quantities of HBV and infectivity according to the serologic markers for a specific patient.

Adolescent↗
PubMed2002

[Effect of recombinant prothymosin alpha on secretion of IFN-gamma, IFN-alpha and TNF-alpha in vitro].

AIM: To study the effect of prothymosin alpha (Pro T alpha) as a fusion protein on secretion of IFN-gamma, IFN-alpha and TNF-alpha in vitro. METHODS: The in vitro study was carried out on the culture of splenocytes, splenic and peritoneal macrophages isolated from Balb/c mice. Splenocytes were incubated with various concentrations of Pro T alpha (1 x 10(-7)-1 x 10(-10) mol.L-1) with or without Con A (5 micrograms.mL-1) for 72 h. Splenic and peritoneal macrophages were respectively treated with Pro T alpha (1 x 10(-7)-1 x 10(-10) mol.L-1) in the presence of LPS (10 micrograms.mL-1) for 24 h. Then IFN-gamma, IFN-alpha and TNF-alpha levels in the supernatant were detected by ELISA. RESULTS: Pro T alpha (1 x 10(-7) mol.L-1) was found to obviously increase IFN-gamma level (P < 0.05) in the supernatant of splenocytes compared with the control group. Moreover, Pro T alpha (1 x 10(-7) mol.L-1) significantly induced the secretion of IFN-alpha (P < 0.01) and TNF-alpha (P < 0.01) in splenic and peritoneal macrophages. CONCLUSION: In vitro, Pro T alpha could increase the secretion of IFN-gamma, IFN-alpha and TNF-alpha.

Adjuvants, Immunologic↗