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H Yan

Publications and source records attributed to H Yan.

At least 55 records · Page 3Linked to original sources
PubMed2001

Development and applications of a complete set of rice telotrisomics.

We previously isolated a complete set of primary trisomics along with many other aneuploids from triploid plants derived from an indica rice variety "Zhongxian 3037." About 30,000 progeny from these trisomic and aneuploid plants were grown each year from 1994 to 1999. The variants that differed morphologically from both the diploids and the original primary trisomics were collected for cytological identification. From these variants, a complete set of telotrisomics covering all 24 rice chromosome arms was obtained. The identities of the extra chromosomes were further confirmed by dosage analysis of the RFLP markers on extra chromosome arms. The telocentric nature of the extra chromosomes in these stocks was verified by fluorescence in situ hybridization (FISH) using a rice centromeric BAC clone as a marker probe. In general, the shorter the extra chromosome arm of a telotrisomic, the stronger the resemblance it bears to the diploid; the longer the extra chromosome arm, the stronger the resemblance to the corresponding primary trisomic. We demonstrated that DNA clones can be rapidly assigned to specific chromosome arms by dosage analysis with the telotrisomics. We also showed that telotrisomics are valuable tools for chromosome microdissection and for developing chromosome-specific DNA markers.

Chromosomes↗
PubMed2001

Molecular genetic analysis of appendiceal mucinous adenomas in identical twins, including one with pseudomyxoma peritonei.

Pseudomyxoma peritonei (PMP) is a clinical syndrome characterized by mucinous ascites and peritoneal lesions composed of histologically bland to low-grade adenomatous mucinous epithelium within pools of extracellular mucin, often with an associated mucinous adenoma of the appendix. There is evidence that the peritoneal lesions in PMP are clonally derived from the associated appendiceal adenoma. Little is known about the molecular genetic alterations or hereditary factors involved in the development of appendiceal mucinous tumors and PMP. We report the only known example of appendiceal mucinous adenomas in identical twin brothers, one of whom developed PMP. We analyzed the status of the K-RAS and APC genes in these tumors using digital polymerase chain reaction and digital single nucleotide polymorphism (SNP) assay. Identical K-RAS mutations were detected in the appendiceal adenoma and peritoneal tumor from the twin with PMP, whereas the adenoma from the other twin harbored a different mutation. Digital SNP analysis demonstrated loss of heterozygosity of APC only in the adenoma from the twin without PMP but not from the appendiceal or peritoneal tumors of the twin with PMP. The adjacent normal tissue in each case retained both APC alleles. The K-RAS mutational analysis supports the view that PMP is clonally derived from the associated appendiceal mucinous adenoma. The lack of loss of heterozygosity of APC in the adenoma and peritoneal tumor from the twin with PMP suggests that loss of heterozygosity of APC is not necessarily involved in the development of all appendiceal adenomas or PMP. The different types of mutations in K-RAS and the different allelic status of the APC locus in the tumors from both twins suggest that mutation in K-RAS and loss of heterozygosity of APC occurs somatically in adenomas and is independent of the identical genetic background of the twins.

Adult↗
PubMed2001

Characterization of euploid backcross progenies derived from interspecific hybrids between Oryza sativa and O. eichingeri by restriction fragment length polymorphism (RFLP) analysis and genomic in situ hybridization (GISH).

Restriction fragment length polymorphism (RFLP) analysis and GISH (genomic in situ hybridization) were performed on euploid plants derived from crosses between Oryza sativa (2n = 24, AA) and two brown planthopper-resistant accessions of O. eichingeri (2n = 24, CC). After screening with 164 RFLP markers, 60 of the 67 euploid plants were identified as introgression lines, each carrying 1-6 small O. eichingeri segments integrated on chromosomes 1, 2, 6, or 10. In the somatic chromosome preparations of F1 hybrid, O. eichingeri chromosomes, fluorescing greenish-yellow in the sequential GISH, appeared to be longer and to contain more heterochromatin than O. sativa ones, and this karyotypic polymorphism can be used to detect some introgressed O. eichingeri segments in euploid plants. In addition, GISH identification presented direct evidence for the transfer of small segments from O. eichingeri to O. sativa chromosome(s) which were subsequently recognized according to their condensation pattern, arm ratio, and chromosome length. The present results would contribute to the molecular mapping and selection of O. eichingeri--derived brown planthopper-resistant gene and positive yield QTLs.

Chromosome Mapping↗
PubMed2001

Facilitating haplotype analysis by fully automated analysis of all chromosomes in human-mouse hybrid cell lines.

Recent evidence suggests that haplotype analysis is essential in recognizing genetic factors involved in the tendency toward a particular disease or pharmacogenetic phenotype, as well as to identify genes involved in multigenic disorders. Because of the increasing need for efficient haplotype tests, a new hybrid system, called conversion technology, was developed. Conversion technology aims at converting the diploid chromosome content into a haploid state so that hybrids contain a single copy of any desired chromosome. A number of mutations can now be identified easily, as they are no longer obscured by the normal sequence present on the other copy of the chromosome. However, the efficient use of this hybrid system depends on a complete analysis of both human and mouse chromosome complements in order to assess the stability of the hybrid cells and to accurately determine their human chromosome content. We describe a new multicolor FISH-based method capable of analyzing both genomes simultaneously in a single hybridization. This new technique should become an instrumental part of inexpensive, reliable haplotype tests.

Animals↗
PubMed2001

Redundant function of Runt Domain binding partners, Big brother and Brother, during Drosophila development.

The Core Binding Factor is a heterodimeric transcription factor complex in vertebrates that is composed of a DNA binding alpha-subunit and a non-DNA binding beta-subunit. The alpha-subunit is encoded by members of the Runt Domain family of proteins and the beta-subunit is encoded by the CBF beta gene. In Drosophila, two genes encoding alpha-subunits, runt and lozenge, and two genes encoding beta-subunits, Big brother and Brother, have been previously identified. Here, a sensitized genetic screen was used to isolate mutant alleles of the Big brother gene. Expression studies show that Big brother is a nuclear protein that co-localizes with both Lozenge and Runt in the eye imaginal disc. The nuclear localization and stability of Big brother protein is mediated through the formation of heterodimeric complexes between Big brother and either Lozenge or Runt. Big brother functions with Lozenge during cell fate specification in the eye, and is also required for the development of the embryonic PNS. ds-RNA-mediated genetic interference experiments show that Brother and Big brother are redundant and function together with Runt during segmentation of the embryo. These studies highlight a mechanism for transcriptional control by a Runt Domain protein and a redundant pair of partners in the specification of cell fate during development.

Animals↗
PubMed2001

Distribution of nitric oxide synthase in stomach myenteric plexus of rats.

AIM: To study the distribution of nitric oxide synthase (NOS) in rat stomach myenteric plexus. METHODS: The distribution of NOS in gastric wall was studied in quantity and location by the NADPH-diaphorase (NDP) histochemical staining method and whole mount preparation technique. RESULTS: NOS was distributed in whole stomach wall, most of them were located in myenteric plexus, and distributed in submucosal plexus.The shape of NOS positive neurons was basically similar, most of them being round and oval in shape. But their density, size and staining intensity varied greatly in the different parts of stomach. The density was 62+/-38 cells mm(2) (antrum), 43+/-32 cells/mm(2) (body), and 32+/-28 cells mm(2) (fundus), respectively. The size and staining intensity of NOS positive neurons in the fundus were basically the same, the neurons being large and dark stained, while they were obviously different in antrum. In the body of the stomach, the NOS positive neurons were in an intermediate state from fundus to antrum. There were some beadlike structures which were strung together by NOS positive varicosities in nerve fibers, some were closely adherent to the outer walls of blood vessels. CONCLUSION: Nitric oxide might be involved in the modulation of motility, secretion and blood circulation of the stomach, and the significant difference of NOS positive neurons in different parts of stomach myenteric plexus may be related to the physiologic function of stomach.

Animals↗
PubMed2001

[Significance of detection of transfusion transmitted virus in extrahepatic tissues].

OBJECTIVE: To investigate the location and distribution of transfusion transmitted virus (TTV) in the liver and extrahepatic tissues. METHODS: TTV DNA was detected in paraffin-embedded autopsy liver and extrahepatic tissues, including liver, pancreas, kidney, spleen, testicle, and heart from 13 patients with non A-G hepatitis by nested-PCR and in situ hybridization (ISH) techniques. RESULTS: Positive hybridization signals of TTV nucleus acid were observed in 5 liver, 3 kidney, 2 pancreas and spleen tissues, respectively. TTV DNA was detected in one from each two samples of testicle and heart. Positive signal was mainly located in nucleoli of the liver and extrahepatic parenchymal cells. There was not obvious pathological damage in those extrahepatic tissues. The positive rate of PCR approximately corresponded to ISH. CONCLUSIONS: TTV can infect hepatic and extrahepatic tissues and its infection in extrahepatic tissues might be responsible for a state of reinfection and higher prevalence in different population.

Adult↗
PubMed2001

[Toxic effects of Cu, Zn and Mn on the inhibition of Chlorella pyrenoidosa's growth].

A standard method of algal bioassay for evaluating the toxicity of toxic chemicals was applied in the study. It was found that safety concentrations of Cu, Zn and Mn for Chlorella pyrenoidosa's growth were 31.8 micrograms/L, 65.0 micrograms/L and 5.5 mg/L, and 96 h-EC50 were 67.3 micrograms/L, 473.0 micrograms/L and 17.0 mg/L, respectively. According to both safety concentration and 96 h-EC50, the toxic sequences of these metals from high to low on the inhibition of C. pyrenoidosa's growth were Cu, Zn and Mn. The different affinities between different metal ions and algal cells are mainly responsible for the different inhibitions of C. pyrenoidosa's growth.

Chlorella↗
PubMed2001

[The growth hormone and insulin-like growth factors axis in liver failure patients].

OBJECTIVE: To measure circulating concentration of growth hormone (GH), insulin-like growth factors 1 (IGF-1), and it's binding protein 1 (IGFBP1) and binding protein 3 (IGFBP3) in patients with sever hepatitis, and to survey the clinical significance of GH-IGFS axis. METHODS: The study population consisted of 18 patients with liver failure caused by serious virous hepatitis, and of 20 normal volunteers. Serum concentration of GH, IGF-1, IGFBP1 and IGFBP3 was determined by ELISA. Liver biochemistric functions were measured by routine methods. RESULTS: Serum concentrations of IGF-1 and IGFBP3 were equally reduced (5.5microgram/ml +/- 6.2 microgram/ml vs 17.6 microgram/ml +/-7.0 microgram/ml, and 2.4 microgram/ml +/-1.3 microgram/ml vs 9.4 microgram/ml +/- 1.7microgram/ml, P<0.001, respectively); increased serum GH and IGFBP1 were observed (9.1ng/ml +/-12.4ng/ml vs 1.6ng/ml +/-2.4ng/ml, P<0.05; 67.9ng/ml+/-50.2ng/ml vs 45.8ng/ml+/-33.1ng/ml, P<0.01) in liver failure patients as compared with the controls. The positive relationship between IGF-1 and IGFBP3 (r=0.91, P<0.001) was observed. The closed relation between the serum IGF-1 and the prognosis of patients was also obtained. IGF-1<10 microgram/ml was in accord with 90% accurate rate of predicted death. CONCLUSIONS: The GH-IGFs axis is significantly abnormal in liver failure patients, suggesting the existence of GH resistance in these patients. Serum IGF-1 may act as a predictor for their prognosis.

Adult↗
PubMed2001

[Sequencing-based typing of HLA-DPB1 and DQB1 exon 2 in patients with type 1 diabetes mellitus].

OBJECTIVE: To investigate the correlation between type 1 diabetes mellitus susceptibility and HLA-DPB1 and DQB1 genes in Shandong Han population. METHODS: HLA-DPB1 and DQB1 genes analysis were performed by sequencing-based typing in 52 type 1 diabetes mellitus patients and 38 normal controls. RESULTS: The frequency of DPB1*2201 in diabetics was significantly higher than that in controls(26.92% vs 5.26%, P<0.01), but the frequency of DPB1*0402 in diabetics was significantly lower than that in controls(11.54% vs 34.21%, P<0.01). The frequencies of DQB1*0201, *0303 and *0604 in diabetics were higher than those in controls (24.04% vs 10.53%, P< 0.01; 22.12% vs 6.58%, P<0.05; 19.23% vs 7.89%, P<0.05), while the frequency of DQB1*0301 in diabetics was significantly lower than that in controls (4.81% vs 25.00%, P<0.01). CONCLUSION: DPB1*2201, DQB1*0201, *0303 and *0604 may be susceptible alleles, and DPB1*0402 and DQB1*0301 may be protective alleles in patients with type 1 diabetes mellitus.

Adolescent↗
PubMed2001

[Hypercoagulation aggravates renal dysfunction in patient with diabetic nephropathy].

OBJECTIVE: To investigate the relationship of hypercoagulation and renal dysfunction in patients with diabetic nephropathy(DN). METHODS: Forty six diabetes type II patients with nephrotic syndrome were divided into 3 groups according to 24 hr creatinine clearance (Ccr) as high, middle and low groups. Fourteen of the 46 patients received warfarin therapy. The parameters of coagulation and fibrolysis as well as renal function were examined. RESULTS: Patients with moderate and major renal dysfunction (M group and L group) displayed higher activities of coagulation than those with mild renal dysfunction (H group) did. Warfarin could obviously improve the status of coagulation and fibrolysis in patients with DN and delay the progress of renal dysfunction. CONCLUSION: Hypercoa-gulation was one of the causes of renal dysfunction in patients with DN.

Creatinine↗
PubMed2001

[Pathogenecity and replication of transfusion transmitted virus in liver tissue by in situ hybridization].

OBJECTIVE: To study its pathogenecity based on infection status and replication of transfusion transmitted virus (TTV) in the liver tissues. METHODS: Using recombinant plasmid as template and symmetrical and asymmetrical polymerase chain reaction (PCR), double-strand and single-strand TTV probes were labeled with digoxigenin. Fifty-six cases of liver biopsy specimens were detected by in situ hybridization, and six positive cases of them were tested further with single-strand probes. RESULTS: TTV DNA was found in 14 of 51 patients with non A and non G hepatitis (27.5%), and five cases in the control group were negative. TTV DNA was mainly observed in the nuclei of hepatocytes and pathologic changes and necrosis in the infected liver cells were not so apparent, but they could be seen in the liver tissues of acute, chronic and severe hepatitis, as well as of liver cirrhosis. TTV genome strand hybridization detected by single-strand probe was consistent with that by double-strand probe. Both TTV genome strand and its complementary strand were present in the two cases of liver specimens, but hybridizational signals were weaker in the latter than those in the former. CONCLUSION: TTV could cause injury and replicate itself in the liver, but no obvious and direct injury to hepatocytes.

DNA, Viral↗
PubMed2001

[HCV-PCR-Hybrid.ELISA for the detection of HCV RNA in serum samples from hepatitis patients].

BACKGROUND: To detect HCV RNA in serum samples from hepatitis patients by using the methods of HCV-Reverse transcription polymerase chain reaction and hybrid ELISA. METHODS: HCV RNA in serum samples was amplified by RT-PCR with one of the primer labeled with biotin. PCR amplified products were detected with microtiter plate hybridization with HCV specific probe, then determined with steptavidin-HRP assay. Anti-HCV in these samples was also detected with ELISA simultaneously. RESULTS: The positive rates of HCV RNA were 81.8% (72/88) in anti-HCV positive group and 57.9% (88/152) in the whole patients group. Serum HCV RNA and anti-HCV positive rates were compared and the consistent rate was 78.9% (120/152, P>0.05). The positive rate of HCV RNA was higher in H.ELISA (57.9%, 88/152) than that in electrophoresis (35.5%, 54/152)(P<0.01). CONCLUSIONS: The HCV-PCR-H.ELISA was a sensitive, specific, stable, semi-quantitative and easy to operate method. This HCV RNA detection was especially beneficial to early diagnosis during viramia period and was helpful for the evaluation of anti-HCV therapy.

Adolescent↗
PubMed2001

[Detection of TTV DNA in liver tissues of patients with non A-G hepatitis by in situ hybridization].

OBJECTIVE: To demonstrate the existence of TT virus(transfusion-transmitted virus, TTV) in liver tissues of patients with unknown etiology. METHODS: Paraffin-embedded liver tissues from 51 cases who were non A-E hepatitis serologically and immunohistochemically negative for HBsAg, HCV NS3 antigen and HGV NS5 antigen were tested by in situ hybridization with Dig TTV DNA probe. RESULTS: The total positive rate of TTV DNA was 27.5% (14/51). Among the different pathological types, the positive rates were 30.8% (4/13) in acute mild hepatitis, 12.5% (1/8) in acute fulminante hepatitis, 42.9% (3/7) in subacute fulminante hepatitis, 33.3% (2/6) in chronic hepatitis, 22.2% (2/9) in active liver cirrhosis, 25% (1/4) in chronic fulminante hepatitis and 25% (1/4) in primary liver carcinoma respectively. Hybridization signals were detected within the nuclei or cytoplasm of the hepatocyte and most of them in nuclei. The positive cells were diffusely scattered in the intralobular areas in acute hepatitis and aggregated in periportal areas in chronic hepatitis or in the form of clustering in pseudolobules in active liver cirrhosis. CONCLUSION: Our results suggest that the TTV detected from liver tissues or sera from patients with unknown etiology is a novel virus, which belongs to hepadnavirus.

Adolescent↗
PubMed2001

Change of visual acuity and related factors in idiopathic optic neuritis.

PURPOSE: To study the change of visual acuity and related factors in idiopathic optic neuritis. METHODS: Retrospectively studying 136 cases (210 eyes) of idiopathic optic neuritis hospitalized in our department during last 5 years. The data was analyzed with the methods of multivariate stepwise regression analysis by SPSS statistic package. RESULTS: The final visual acuity was very strongly related positively to the initial visual acuity at the time point of starting treatment and negatively to the time span beginning the treatment to the time showing improvement, age of patient and the duration from onset of the disorder to the time point of treatment beginning. CONCLUSIONS: Promptly right treatment can significantly change the natural course and the final vision of optic neuritis. Severe visual loss, old age, longer time without right therapy and slow improvement after the treatment may indicate an unfavorable final visual recovery. The different dosages of steroid applied in this study was not significant in view of the final visual acuity.

Adolescent↗
PubMed2001

[Character of alpha-crystallin molecular chaperone activity in selenite cataract].

PURPOSE: To evaluate the character of alpha-crystallin molecular chaperone activity in selenite cataract. METHODS: alpha-Crystallin from lenses of normal young rats and lenses with selenite cataract were separated and purified by gel filtration chromatography. The chaperone activity of alpha-crystallin was assayed by mearsuring heat-induced aggregation and scattering of catalase. RESULTS: alpha-Crystallin in both normal and cataractous lenses specifically prevented catalase against thermal aggregation compared with control proteins. The preventive ability in alpha H-crystallin was less than in alpha L-crystallin. Chaperone activity was diminished in selenite cataract. There was statistically significant difference in chaperone activity between normal and cataractous lenses in both alpha H-crystallin and alpha L-crystallin respectively. CONCLUSION: The reduction of alpha-crystallin chaperone activity in selenite cataract by preventing thermal aggregation of catalase is an important process in cataract formation.

Animals↗