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Y B Chen

Publications and source records attributed to Y B Chen.

At least 37 records · Page 2Linked to original sources
PubMed2001

[A study of genetic polymorphism of the STR locus D2S441 in Chinese Han population in Chengdu].

Using PCR and PAG, followed by silver staining, the tetrameric STR D2S441 locus was studied in 260 unrelated Chinese individuals living in Chengdu. 9 alleles and 26 genotypes were observed. The range of fragment size was 131 bp to 155 bp. The genotype distribution of D2S441 locus in Han population was in accordance with Hardy-Weinberg equilibrium. Family survey confirmed Mendelian inheritance of alleles. The discriminating power (Dp), observed heterozygosity (H), polymorphism information content (PIC) and power of exclusion (PE) were 0.9084, 0.7885, 0.7390 and 0.5778 respectively. The results demonstrated that this locus was highly polymorphic and could be used for forensic identification and paternity testing.

Alleles↗
PubMed2001

[Improvement of a method for separation and determination of amino acids].

A method for separation and determination of amino acids using pre-column derivatization with 6-aminoquinoline-N-hydroxysuccinimido-carbamate (AccQ. Tag) was improved. The technique developed for rapid separation and determination of amino acids by AccQ. Tag method is described. The 18 amino acids and taurine are rapidly separated and determined by AccQ. Tag special chromatographic column(3.9 mm i.d. x 150 mm) within 17.5 min(the analysis period is 22.5 min) by changing the flow rate from 1.0 mL/min to 2.0 mL/min. In place of the AccQ. Tag special chromatographic column, the Nova-Pak C18 column(3.9 mm i.d. x 150 mm), Nova-Pak C18 column(4.6 mm i.d. x 150 mm), Symmetry C18 column(3.9 mm i.d. x 150 mm) or Waters Xterra RP-18 column, can be used to separate and determine the amino acids rapidly in the same manner. But among them the Symmetry C18 column is the best substitute for AccQ. Tag column. The separation time is 14.5 min and the analysis period is 20.0 min only. The price is much cheaper than the AccQ. Tag column.

Amino Acids↗
PubMed1999

Human single-chain Fv immunoconjugates targeted to a melanoma-associated chondroitin sulfate proteoglycan mediate specific lysis of human melanoma cells by natural killer cells and complement.

Two antimelanoma immunoconjugates containing a human single-chain Fv (scFv) targeting domain conjugated to the Fc effector domain of human IgG1 were synthesized as secreted two-chain molecules in Chinese hamster ovary and Drosophila S2 cells, and purified by affinity chromatography on protein A. The scFv targeting domains originally were isolated as melanoma-specific clones from a scFv fusion-phage library, derived from the antibody repertoire of a vaccinated melanoma patient. The purified immunoconjugates showed similar binding specificity as did the fusion-phage clones. Binding occurred to human melanoma cells but not to human melanocytes or to several other types of normal cells and tumor cells. A 250-kDa melanoma protein was immunoprecipitated by the immunoconjugates and analyzed by mass spectrometry, using two independent procedures. A screen of protein sequence databases showed an exact match of several peptide masses between the immunoprecipitated protein and the core protein of a chondroitin sulfate proteoglycan, which is expressed on the surface of most human melanoma cells. The Fc effector domain of the immunoconjugates binds natural killer (NK) cells and also the C1q protein that initiates the complement cascade; both NK cells and complement can activate powerful cytolytic responses against the targeted tumor cells. An in vitro cytolysis assay was used to test for an immunoconjugate-dependent specific cytolytic response against cultured human melanoma cells by NK cells and complement. The melanoma cells, but not the human fibroblast cells used as the control, were efficiently lysed by both NK cells and complement in the presence of the immunoconjugates. The in vitro results suggest that the immunoconjugates also could activate a specific cytolytic immune response against melanoma tumors in vivo.

Animals↗
PubMed1999

Expression of photosynthesis genes in relation to nitrogen fixation in the diazotrophic filamentous nonheterocystous cyanobacterium Trichodesmium sp. IMS 101.

The daily cycle of nitrogenase expression in the marine filamentous nonheterocystous cyanobacterium Trichodesmium spp. is controlled by a circadian rhythm. We evaluated the rhythm of two key photosynthesis genes, psbA of photosystem II and psaA of photosystem I, in Trichodesmium sp. IMS 101 using the 3 criteria for an endogenous rhythm. The transcript abundance of psbA and psaA transcripts oscillated with a period of ca. 24 h under a 12 h light/12 h dark regime. At 24 degrees C and 28 degrees C the cyclic pattern of transcript abundance was maintained for at least 58 h under constant light conditions, whereas the periods were about 24 h at 24 degrees C, and 26-30 h at the higher temperature. The cycles of psbA and psaA gene expression were entrained using light-dark cues. Transcription of nifHDK was initiated prior to the light period, followed by psbA and finally psaA. There was a 90 degrees (6 h) phase difference between the net accumulation of nifHDK and psbA transcripts, as well as between that of psbA and psaA transcripts. Results of inhibitor experiments indicated that psbA and psaA transcription was regulated differently by initiation and degradation during the light period. Short-term changes of light conditions resulted in significant effects on psbA transcription and nitrogenase activity, but had less of an effect on psaA and nifHDK transcription.

Bacterial Proteins↗
PubMed1999

Bakamjian island flap for patch esophagoplasty of the cervical esophagus.

Esophageal stricture may result from chemical injury, progressive ischemic fibrosis, constriction of a previous esophagocolonic anastomosis site, or vascular insufficiency of the transferred gut. The Bakamjian skin island flap was employed as a patch for esophagoplasty to relieve focal esophageal stricture in 12 patients. One of these patients developed postoperative leakage, which necessitated a secondary revision. The others had a smooth postoperative course and were able to resume oral intake with ease. It is concluded that the Bakamjian skin island flap is a reliable and convenient method for repairing short defects of the cervical esophagus in one stage.

Adult↗
PubMed1999

Partial failure of sternal fusion in an adolescent.

We describe the case of an adolescent girl who had an isolated cranial sternal cleft without any associated abnormalities; the cleft had been well tolerated since her birth. A review of the literature shows that such cases are uncommon. In such cases, surgery is only for cosmetic reasons.

Abnormalities, Multiple↗
PubMed1999

[Diagnostic imaging of tracheobronchial tuberculosis. Apropos of a case].

We report a new case of tracheo-bronchial tuberculosis. Diagnosis was suggested on CT examination first and then confirmed by endoscopy and bacteriological examinations. We discuss the possible mechanisms of stenosis. We present the radiological features of tracheo-bronchial tuberculosis, mainly helical CT features and we discuss and illustrate differential diagnosis. We emphasize the role of 3 D and multiplanar reconstructed CT images that may help visualizing the stenosis at different levels, its craniocaudal extent as well as the boundaries between the stenosis and surrounding tissues. Moreover helical CT appears superior to bronchofibroscopy in diagnosing peribronchial infiltration.

Adolescent↗
PubMed1999

Long-term survival of patients with mandibular osteosarcoma.

Osteosarcoma generally has a poor prognosis. Osteosarcoma of the mandible is rare and may have a less aggressive course. Three patients with osteosarcoma of the mandible were treated during the past 19 years at National Taiwan University Hospital. All were women, with an average age of 49 years. The patients were treated with radical excision of the tumor, with either pre- or postoperative radiotherapy. None of the patients received chemotherapy. Reconstruction with iliac osteocutaneous free flap, fibular osteoseptocutaneous free flap, or Leibinger reconstruction plate was performed to repair the facial defects resulting from tumor resection or radiation-induced necrosis. The three patients were alive and without evidence of recurrence at the time of writing, with follow-up periods ranging from 7 to 18 years. All had acceptable facial contour and satisfactory oromandibular function after reconstruction. These results support the effectiveness of wide resection with radiotherapy for treatment of mandibular osteosarcoma. With the availability of microsurgical reconstruction and biocompatible reconstruction plates, we advocate extensive ablation of this tumor. Long-term survival, good functional recovery, and acceptable facial contour can be expected.

Adult↗
PubMed1998

Circadian rhythm of nitrogenase gene expression in the diazotrophic filamentous nonheterocystous cyanobacterium Trichodesmium sp. strain IMS 101.

Recent studies suggested that the daily cycle of nitrogen fixation activity in the marine filamentous nonheterocystous cyanobacterium Trichodesmium sp. is controlled by a circadian rhythm. In this study, we evaluated the rhythm of nitrogen fixation in Trichodesmium sp. strain IMS 101 by using the three criteria for an endogenous rhythm. Nitrogenase transcript abundance oscillated with a period of approximately 24 h, and the cycle was maintained even under constant light conditions. The cyclic pattern of transcript abundance was maintained when the culture was grown at 24 and 28.5 degrees C, although the period was slightly longer (26 h) at the higher temperature. The cycle of gene expression could be entrained with light-dark cues. Results of inhibitor experiments indicated that transcript abundance was regulated primarily by transcription initiation, rather than by degradation. The circadian rhythm, the first conclusively demonstrated endogenous rhythm in a filamentous cyanobacterium, was also reflected in nitrogenase MoFe protein abundance and patterns of Fe protein posttranslational modification-demodification.

Bacterial Proteins↗
PubMed1998

[Endobronchial lipoma: apropos of a case with dual localization].

Endobronchial lipoma is an uncommon benign tumor. It is composed of fat tissue and is visible on CT scanner. We report an unusual case of a patient who developed two endobronchial lipomas. The first lipoma was removed 10 years earlier. We emphasize the contribution of computed tomography in the diagnosis of endobronchial lipoma. Cases of multiple lipomas are very scarce in the literature.

Bronchial Neoplasms↗
PubMed1997

[Yield and cytotoxicity of tumor-infiltrating lymphocyte(TIL) following immunochemotherapy]

Tumor-infiltrating lymphocyte (TIL) in the primary site of oral SCC treated with S-PVP of PVP therapy was collected respectively and its yield,that is calculating the amount of TIL per tumor tissue.The cytotoxicity of TIL against the target,Tca8113 was detected.The results showed that the yield of TIL in S-PVP group was three times over that in PVP group.At the ratio of 5 to 1 (effector to target) the cytotoxicity was 38% in S-PVP group and 32% in PVP group.There was no significant difference in its cytotoxicity between two groups.The results revealed that immunochemotherapy of S-PVP regimen for treating oral SCC had neither direct damage to tumor cell from the agents nor antitumor immune reactivity with BRM stimulating an increasing in numbers of TIL.

Journal Article↗
PubMed1997

Management of fulminant hepatic failure at Queen Mary Hospital.

OBJECTIVE: To evaluate the strategy of the management of patients with fulminant hepatic failure at Queen Mary Hospital. METHODS: In the period 1994 through 1996, 30 patients with fulminant hepatic failure were managed by active supportive treatment in the Intensive Care Unit in preparation for liver transplantation. Liver transplantation was performed in 14 patients (aged 17-47), 3 of whom received liver grafts from brain-stem dead donors and 11 received live-related grafts from family members. The median duration from admission to liver transplantation was 3 days (range: 1-6 days). RESULTS: Thirteen patients (93%) survived the liver transplantation and are well after a median period of follow-up of 7 months. The only mortality was in a patient with pre-exiting renal transplantation and hepatitis B infection, who died from intra-abdominal candidiasis. CONCLUSION: The strategy of active supportive treatment and early liver transplantation using live-related liver graft is probably the key to the success of the management of fulminant hepatic failure in our series.

Adolescent↗
PubMed1995

[Effect of bushenhuoxue tablet on serum lipid peroxide, blood lipid and blood sugar in type II diabetics].

Sixty-eight patients suffering from diabetes mellitus (DM) type II with Kidney Deficiency and blood stasis were enrolled and divided randomly into treatment group (34 cases) and placebo group (34 healthy subjects). The amount of serum lipid peroxide (LPO), blood lipid and blood sugar was determined. The results showed that the serum LPO in treatment group was higher than that in placebo group. The serum LPO increased significantly in DM patients with vascular disease or with uncontrolled blood sugar. The serum LPO was positively correlated with triglyceride (TG). After using Bushenhuoxue Tablet (BSHX) serum LPO lowered, blood sugar decreased and high density lipoprotein-cholesterol (HDL-C)increased in treatment group, but in placebo group these three parameters were not changed significantly. These results indicated that LPO reaction in type II DM patients increased. The higher the blood sugar and TG or complicated with vascular disease, the LPO reaction enhanced markedly. BSHX tablets have the function of reducing the serum LPO and blood sugar, clearing cholesterol. Therefore, this tablet will have a good prospect in the prevention and treatment for DM patients complicated with vascular disease.

Adult↗
PubMed1994

Major mandibular reconstruction with vascularized bone grafts: indications and selection of donor tissue.

Free vascularized bones have been shown by many specialists to exhibit specific capabilities of reconstructing a major mandibular defect and can solve problems that may be insoluble by other methods. Nevertheless, absolute indications for using vascularized bone for major mandibular reconstructions have not been sufficiently well delineated to convince people of always considering vascularized bone for major mandibular reconstructions as a first option. Based on our experience with 55 major mandibular reconstructions, we might delineate the absolute indications for using free vascularized bone for major mandibular reconstructions explicitly: 1) osteoradionecrosis of mandible or on irradiated tissue bed; 2) hemimandibular reconstruction with a free end facing the glenoid fossa; 3) long segment mandibular defect, especially across the symphysis; 4) inadequate skin or mucosal lining; 5) defects demanding sandwich reconstruction; 6) inability to obtain secure immobilization on the reconstructed unit; 7) failure of reconstruction by other methods; 8) near total mandibular reconstruction. Selection of donor tissue should be according to 1) the amount of tissue deficiencies, 2) composition of the defect, 3) design and placement of the flap, 4) irradiation on the recipient site or not, 5) which vessels to be used, 6) which flap has the appropriate vessel length 7) skin color and texture of the donor tissue, 8) how many osteotomies required to stimulate the curvature of the resected mandible 9) speed of bony union, 10) feasibility of future osseointegration. We have used three kinds of vascularized bones (iliac bone, fibula, scapula). Iliac bone was most frequently used, and has always been our first choice, since it can carry good quality bone, a large skin flap, and ample soft tissue. The fibula has the merit of being less bulky and good for simultaneous intraoral lining, but the contour is more rigid and the bony height is insufficient. The scapula bone is rarely used at present because of its relative inconvenience.

Adult↗
PubMed1994

A high-precision ultrasonic system for vertical movement counts in rats.

A microcomputer-aided ultrasonic system was used to measure vertical displacement of rats in response to drug injection. The system utilizes an inexpensive PC/AT microcomputer for data collection and can distinguish between number of vertical movements of small (i.e., greater than 5 mm, but less than 15 mm), and large (i.e., greater than 15 mm) displacements. In addition, rest time denotes the time elapsed for the vertical motion of less than 5-mm displacements. As little as 0.32 mg/kg of d-amphetamine increased the average amount of both small and large activity (i.e., number of movements), but decreased the average amount of rest time in rats. On the contrary, as little as 2.5 mg/kg of chlorpromazine decreased the average amount of both small and large activity, but increased the rest time in rats. When the animal activity was measured with an infrared light system, the activity responses to drugs were not detectable. Thus, it appears that the ultrasonic method provides a high-precision system for measuring animal behaviors.

Animals↗