Search PubMed⌕ Search

Biomedical subjects

H Yan

Publications and source records attributed to H Yan.

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

Histopathologic analysis in 46 patients with pseudomyxoma peritonei syndrome: failure versus success with a second-look operation.

Pseudomyxoma peritonei syndrome is a disease characterized by mucinous ascites and mucinous tumor disseminated on peritoneal surfaces; the disease almost always originates from a perforated appendiceal epithelial tumor. Histopathologic assessment of aggressive versus noninvasive character of the mucinous tumor has been shown to have an impact on survival in patients treated with cytoreductive surgery and intraperitoneal chemotherapy. Out of a database of 312 patients having a complete cytoreduction for pseudomyxoma peritonei syndrome, 46 patients (24 male and 22 female) had at least one second-look surgery. Before this review, all 46 of these patients were clinically uniformly categorized with a diagnosis of pseudomyxoma peritonei. Using the criteria described by Ronnett and colleagues, all specimens from the multiple surgical procedures performed on these patients were reviewed and reclassified as disseminated peritoneal adenomucinosis (adenomucinosis), adenomucinosis/mucinous adenocarcinoma (hybrid), or mucinous adenocarcinoma. The review was performed in a blinded fashion by a single pathologist (HY). To facilitate a critical evaluation of these histopathologic assessments, the patients were separated into two groups: (1) 19 patients who had a second-look surgery that was unsuccessful in that they went on to die of their disease or in that they currently have disease progression and a limited survival and (2) 27 patients who had a successful second look and currently continue disease free with a minimum 3-year follow-up period. As a result of this review, 11 of 19 patients with an unsuccessful second look and originally designated pseudomyxoma peritonei were reclassified as hybrid-type malignancy (four patients) or mucinous adenocarcinoma (seven patients). Only two patients were reclassified in the successful second-look group (P =.0005). Transitions from a less aggressive to a more invasive histology from one cytoreduction to the next occurred on 13 occasions in patients whose second-look surgery failed and in one patient with a successful second-look surgery (P <.0001). Seven patients retained a histologic classification of disseminated peritoneal adenomucinosis but went on to die of an aggressive disease process. Clinical assessments suggested that failure of second-look surgery for pseudomyxoma peritonei was associated with a biologically more aggressive disease. Unsuccessful second-look surgery for patients with a clinical diagnosis of pseudomyxoma peritonei tumor was often related to an inaccurate initial histologic classification of appendiceal mucinous tumor. Also, a transition from less to more aggressive histology was frequently seen in patients dying of this disease. Assessment of tumor histology can predict the outcome if a uniform surgical treatment is used in patients with peritoneal dissemination of mucinous epithelial tumors of the appendix.

Adenocarcinoma, Mucinous↗
PubMed2001

Studies on the clinical efficacy and pharmacokinetics of low-dose arsenic trioxide in the treatment of relapsed acute promyelocytic leukemia: a comparison with conventional dosage.

Twenty cases of patients with relapsed acute promyelocytic leukemia (APL) were entered into this study for evaluating the clinical efficacy and pharmacokinetics of low-dose arsenic trioxide (As2O3). As2O3 was given at a daily dose of 0.08 mg/kg intravenously for 28 days. Pharmacokinetic study was carried out in eight patients. 16/20 (80%) patients achieved CR. The occurrence of some toxic events including gastrointestinal disturbance, facial edema and cardiac toxicity seemed reduced in the low-dose group than those in the standard-dose group. Differentiation changes were observed in peripheral blood, as well as in bone marrow (BM). Pharmacokinetic study showed that the plasma concentration increased soon after administration of As2O3 with the peak values of 1.535-3.424 micromol/l. After infusion, the plasma concentration was around 0.1-0.5 micromol/l. The arsenic concentration of the plasma of BM aspirates 24 h after administration in five patients was close to the level needed for differentiation-inducing effect. The estimated 2-year OS and RFS were 61.55+/-15.79% and 49.11+/-15.09% respectively, with no difference as compared with those in patients treated with conventional dose (P = 0.2865 and 0.7146, respectively). In conclusion, we demonstrated that low-dose As2O3 had the same effect as the conventional dosage and the mechanism of low-dose arsenic seemed to primarily induce differentiation of APL cells.

Adolescent↗
PubMed2001

Molecular cytogenetic characterization and clinical relevance of additional, complex and/or variant chromosome abnormalities in acute promyelocytic leukemia.

Acute promyelocytic leukemia (APL) is characterized by typical morphological manifestation, t(15;17) translocation and active response to all-trans retinoic acid (ATRA) in the great majority of patients. However, a subset of APL cases may present atypical phenotypic, cytogenetic or molecular features at different stages of the disease. The biological and clinical significance of these features sometimes remains obscure. In this study, 284 APL patients were cytogenetically analyzed and precise diagnosis was performed according to the molecular cytogenetic results. Twenty-six APL patients were identified as having additional, complex and/or variant chromosomal abnormalities at diagnosis or at relapse, 16 of them being further analyzed using fluorescence in situ hybridization (FISH) or chromosome painting (CP). Interestingly, some of these chromosomal aberrations were found to be associated with atypical morphology and/or drug response, indicating a genotype-phenotype correlation. Analysis of the complex karyotype may also allow a better understanding of the levels of cellular origin of the leukemogenesis. Examination of the remission induction and survival data showed that the presence of the additional/complex chromosome abnormalities was related to the prognosis in both primarily diagnosed and relapsed patients in this series.

Adolescent↗
PubMed2001

Feasibility and clinical significance of real-time quantitative RT-PCR assay of PML-RARalpha fusion transcript in patients with acute promyelocytic leukemia.

INTRODUCTION: To study the relationship between the expression level of the PML-RARalpha fusion transcripts and the clinical status and efficiency of the therapy in acute promyelocytic leukemia (APL) patients, we applied a very sensitive and specific real-time Reverse Transcription Polymerase Chain Reaction (RT-PCR) system to quantify the dose of PML-RARalpha fusion transcripts in a series of APL patients at distinct disease stages. MATERIALS AND METHODS: A total of 31 APL patients (19 males and 12 females; aged from 8 to 74 years) from eight hospitals in Shanghai were analysed. Real-time Quantitative RT-PCR was used to measure the normalized dose (DoseN) of PML-RARalpha fusion transcripts. RESULTS: A wide range of PML-RARalpha DoseN above 1 x 10(3) was noted in 25 newly diagnosed patients. PML-RARalpha DoseN was significantly decreased after remission induction with ATRA, ATRA/chemotherapy or As2O3 and further reduced after consolidation. The fact that all patients with long disease free survival had a constantly low PML-RARalpha DoseN below 2 x 10(2) and a higher level predicted impending relapse suggests that this value could serve as a 'threshold' for molecular remission. PML-RARalpha DoseN was also of prognostic value in a group of relapsed patients, since good response to As2O3 reinduction was accompanied by a remarkable reduction of fusion transcript level, whereas patients with high PML-RARalpha Dose(N) after the second CR tended to relapse again rapidly. CONCLUSION: These results confirm that real-time RT-PCR assay for PML-RARalpha transcripts in APL patients is useful in reflecting leukemic burden, assessing response to treatment and indicating the ultimate clinical outcome or curability of disease.

Adolescent↗
PubMed2001

Pedunculated peritoneal surface polyps in pseudomyxoma peritonei syndrome.

AIMS: Pseudomyxoma peritonei syndrome is a rare disease that originates from an adenomatous lesion of the appendix that, from pressure, perforates to gain access to the free peritoneal cavity. The relative sparing of the small bowel surfaces allows for complete cytoreduction even though many kilograms of mucinous tumour exist at other sites within the abdomen and pelvis. The purpose of this study was to examine the mechanism whereby the small bowel remains free of gross tumour and peritoneal surface polyps form. METHODS AND RESULTS: Peritoneal surface polyps were harvested and examined grossly and histologically. A hypothesis for their formation on small bowel and small bowel mesentery was proposed. Polyps are known to be associated with repeated motion of enteric contents moving past adenomatous tissue so that, over time, an elongated stalk is created. We have repeatedly observed pedunculated polyps on the peritoneal surface of the small bowel in patients with pseudomyxoma peritonei syndrome. No other site within the peritoneal cavity has had a pseudomyxoma polyp located upon its surface. CONCLUSIONS: The peristaltic motion of the small bowel causes adherent adenomatous tissue to develop a stalk on the peritoneal surface. Motion not only creates polypoid lesions but also repeatedly clears mucinous tumour cells from the small bowel surface. With pseudomyxoma peritonei and with other types of cancerous dissemination, prevention of adherence by motion may interfere with the implantation of malignant cells.

Biomarkers↗
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↗