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P Yang

Publications and source records attributed to P Yang.

At least 289 records · Page 16Linked to original sources

Prognostic implication of the p53 protein and Ki-67 antigen immunohistochemistry in malignant fibrous histiocytoma.

BACKGROUND: Mounting evidence indicates that p53 regulates cell growth and abnormal p53 immunophenotypic expression is associated with an unfavorable prognosis for patients with some types of carcinoma. The prognostic significance of p53 overexpression in malignant fibrous histiocytomas (MFHs) of soft tissue has not yet been elucidated. METHODS: Expressions of p53 protein and Ki-67 antigen in 54 primary MFHs of soft tissue were investigated immunohistochemically and indexed quantitatively by counting the number of immunoreactive nuclei versus the total neoplastic nuclei in the representative fields of each tumor to evaluate their prognostic implications and interrelations with other clinicopathologic parameters. RESULTS: The percentages (labeling indices [LIs]) of p53 and Ki-67-immunoreactive nuclei versus the total neoplastic nuclei were 0.1-93.2% (mean +/- standard deviation [SD], 40.6% +/- 21.8%) and 5.3-90.8% (mean +/- SD, 42.7% +/- 29.4%), respectively. The Ki-67 LI correlated with histologic grade (P = 0.01498), primary tumor size (P = 0.04985), disease free interval (reverse correlation, P = 0.00776), and recurrence and metastasis (P = 0.00360). The p53 LI correlated with primary tumor size (P = 0.00431) but did not show any significant correlation with histologic grade, Ki-67 LI, primary tumor size, disease free interval, or recurrence and metastasis. Other significant correlations included histologic grade and disease free interval (P = 0.00010), primary tumor size and disease free interval (reverse correlation, P = 0.00869), histologic grade and recurrence (P = 0.02714), and primary tumor size and primary tumor location (P = 0.00028). In the grouped survival analysis, patients with recurrence or metastasis or with tumors of larger size (> or = 7 cm), high histologic grade, or higher Ki-67 LI (> or = 25%) had a significantly reduced survival (P < 0.05). The different p53 immunohistochemical expression and the different histologic types did not reflect different cumulative survival (P > 0.05). Regression analysis revealed that the primary tumor size and histologic grade, but not Ki-67 or p53 LIs, were independent statistical variables for prognostication. CONCLUSIONS: These results indicate that (1) primary tumor size and histologic grade are two important prognostic factors, (2) Ki-67 LI should be used in adjunct with other main prognostic factors for patients with MFHs, and (3) nuclear p53 overexpression in MFHs of soft tissue is a comparatively common event that has no prognostic implication.

Adult↗

Retroflexion of the sigmoidoscope for the detection of rectal cancer.

Flexible sigmoidoscopy is a procedure that is commonly used by primary care physicians for the evaluation of rectal disorders and for colorectal screening. Retroflexion of the endoscope improves views of the anorectum and rectal vault, which increases the diagnostic yield of sigmoidoscopy. We report three cases of rectal lesions that were not detected when flexible sigmoidoscopy was performed without retroflexion. The lesions were all malignant or premalignant. The illustrative cases demonstrate the value of retroflexion in flexible sigmoidoscopy for the detection of rectal lesions.

Adenocarcinoma↗

Association of childhood rhabdomyosarcoma with neurofibromatosis type I and birth defects.

Rhabdomyosarcoma (RMS) is an uncommon malignant soft tissue sarcoma whose cause is largely unknown. Reported risk factors include genetic alterations (e.g., p53 mutations, a defective gene at 11p15.5, or specific chromosomal translocation of t(2:13)), and parents' use of drugs around the time of conception. We present results from a national, case-control study of 249 RMS cases (170 males and 79 females) and 302 controls (196 males and 106 females). The cases, aged 0-20 years at diagnosis, were identified via the Intergroup RMS Study-III during 1982-1988. Controls were selected by random digit telephone dialing. As a supplement to the original study, information on genetic diseases and birth defects (BD) was collected from the subjects' parents by telephone interview. Fifty-six (22.5%) cases and 55 (18.2%) controls were reported to have genetic diseases or BD (odds ratio [OR] = 1.30,95% confidence interval [CI] = 0.85-2.02, P = .21). The case group had a significantly higher frequency of neurofibromatosis type I (NF1) than did the control group, i.e., five cases (2.0%) had NF1 vs. zero controls (P = .02). The case group also had a higher frequency of major BDs than did the control group (6.0% vs. 2.6%, OR = 2.36, 95% CI = 0.92-6.52, P = .05). However, this excess was only observed in males (7.6% vs. 2.6%, OR = 3.16, 95% CI = 1.02-10.41, P = .02). Among the 15 cases having both RMS and major BDs, six (40.0%) had both conditions in the same regional anatomic site: Two (13.3%) had both in the extremities, two (13.3%) in the genitourinary system, and two in the head and neck. These findings suggest that common genetic mechanisms or in utero exposures may be involved in the development of many childhood tumors and congenital abnormalities.

Adolescent↗

Structural and functional characterization of two wheat histone H2B promoters.

Two wheat histone H2B genes (TH123 and TH153) were isolated. Nucleotide sequence analysis revealed that some characteristic sequence motifs were conserved in both the 5'- and 3'-flanking regions. A canonical TATA box and several CCAAT sequences were present in the presumed promoter regions. Motifs similar or identical to the hexamer (ACGTCA) and octamer (CGCGGATC) motifs that are positive cis-acting elements of the wheat H3 (TH012) promoter were also observed in both the H2B promoters. A gel mobility shift assay indicated that the hexamer and hexamer-like motifs bound the wheat bZIP proteins HBP-1a and/or HBP-1b in vitro. A novel sequence motif, (A/T)(G/A)AAAT(A/G), was found downstream of a translational stop codon as observed in several plant histone H2B cDNAs. Promoter activity was analyzed with H2B promoter-GUS fusion genes in the transient system using tobacco protoplasts. Studies of the promoter function in transgenic tobacco plants showed that the H2B promoters were preferentially active in meristematic tissues. Taken together, our data indicate that the H2B genes are regulated, in part, by the same mechanism as found in H3 and H4 gene transcription.

Amino Acid Sequence↗

Differentiation and proliferative activity in benign and malignant cartilage tumors of bone.

To assess the histological grade in benign and malignant cartilage tumors of bone by more objective methods, we examined the differentiation and proliferative activity of tumor cells in six enchondromas, five chondroblastomas, and 13 chondrosarcomas immunohistochemically. A variable number of cells in all tumors showed S-100 protein and vimentin immunoreactivity. In fully differentiated cartilage of enchondromas and low grade chondrosarcomas, tenascin, which is an extracellular matrix glycoprotein, was present in small amounts or absent but was increased at the periphery of tumor lobules and even in the matrix throughout the high grade chondrosarcomas. Higher rate and intensity of proliferating cell nuclear antigen (PCNA) reactivity were found in chondrosarcomas, especially in spindle-shaped cells of high grade tumors, than in enchondromas. The distribution of PCNA-positive cells almost corresponded to the regions with tenascin reactivity. One tumor of high grade chondrosarcoma showed p53 protein immunoreactivity. Aberrant expression of cytokeratin was observed in four chondroblastomas. The expression of desmin was identified in relatively large proportions of enchondromas and chondrosarcomas, regardless of their benign or malignant nature and histological grade. Smooth muscle or muscle-specific actins also were present in a smaller number of tumors. Based on these findings, it is concluded that unusual staining characteristics were present, in addition to those of a chondroblastic nature, in the cartilage tumors of bone. Tenascin and PCNA positivity of various degrees in all chondroblastomas may suggest that they are chondrogenic tumors having a relatively high proliferative activity, albeit their benign clinical course. Proliferative activity of tumor cells in enchondromas and chondrosarcomas correlated well with their histological grade. Tenascin may play a role in promoting tumor cell proliferation of cartilagenous neoplasms and, on the other hand, the alterations of extracellular matrix involving tenascin synthesis seem to be a result of tumor development.

Adolescent↗

Synthesis, characterization and antibacterial activity of novel Fe(III), Co(II), and Zn(II) complexes with norfloxacin.

Three novel complexes of norfloxacin (abbreviated as NFL), [M(NFL)2(H2O)2]Cl3.6H2O, (M = Fe, Co), and [Zn(NFL)2]Cl2.7H2O, have been prepared. The compounds were characterized by IR, UV-Vis, NMR spectra, molar conductivity, and elemental analyses. In all of the complexes, the ligand NFL was coordinated through two carboxyl oxygen atoms. Octahedral and tetrahegon geometries have been proposed for Fe(III)-, Co(II)-complexes and Zn(II)-complex, respectively. In vitro test of susceptibility of Fe(III)- and Zn(II)-complexes showed stronger activity than that of norfloxacin against G(-) E.Coli and Bacillus dysenteriae bacteria.

Anti-Infective Agents↗

Defective expression of hematopoietic cell protein tyrosine phosphatase (HCP) in lymphoid cells blocks Fas-mediated apoptosis.

Protein tyrosine dephosphorylation after Fas cross-linking occurred in Fas apoptosis-sensitive CEM-6 cells but not in Fas apoptosis-resistant MOLT-4 cells, and apoptosis in the CEM-6 cells could be inhibited by the protein tyrosine phosphatase inhibitor, pervanadate. The time course and level of dephosphorylation were correlated with increased hematopoietic cell protein tyrosine phosphatase (HCP) activity, but not with the activity of two other tyrosine phosphatases. The level of expression of HCP was correlated with Fas apoptosis function in eleven human and murine Fas-positive lymphoid cell lines. Expression of recombinant HCP in the MOLT-4 cell line converted this Fas apoptosis-resistant cell line to Fas apoptosis sensitive. HCP-mutant mev/mev mice exhibited increased expression of Fas but decreased Fas-mediated apoptosis function in lymphoid organs after anti-mouse Fas antibody treatment in vivo. Thus, HCP-mediated protein dephosphorylation is involved in the delivery of the Fas apoptosis signal in lymphoid cells.

Animals↗

Aneurysmal fibrous histiocytoma of the skin. A histological, immunohistochemical, and ultrastructural study.

We present two cases of aneurysmal fibrous histiocytoma of the skin on the lower extremities of a 41-year-old man and a 23-year-old woman. Both the tumors appeared clinically as cutaneous nodules with a recent history of rapid growth and showed microscopically a unique formation of blood-filled tissue spaces and a storiform proliferation of histiocyte-like and fibroblast-like cells in a capillary-rich stroma. Such clinical and histologic features fit the original description of this entity. Immunohistochemically the tumor cells of both cases were immunoreactive for factor XIIIa, Mac 387, and vimentin and gave negative results for factor VIII-related antigen, desmin, actin, and S-100 protein. Ultrastructurally the tumors were composed mainly of siderosome-containing histiocyte-like cells, fibroblast-like cells, and intermediate cells and lacked prominent proliferation of endothelial cells. Thus, the ultrastructural findings agreed with the immunophenotypes expressed by the tumor cells, supporting the fibrohistiocytic origin of this lesion. In view of the recent rapid growth, the presence of hemorrhagic pseudocysts, the extravasation of erythrocytes, and the high vascularity of the present tumors, we emphasize the importance of distinguishing this lesion from angiomatoid fibrous histiocytoma and cutaneous malignancies of mesenchymal origin.

Actins↗

P-ANCA in monozygotic twins with inflammatory bowel disease.

Perinuclear antineutrophil cytoplasmic antibodies (P-ANCA) have been demonstrated in patients with ulcerative colitis and in a higher frequency than expected in their first degree relatives. A hypothesis was proposed that P-ANCA is genetically determined and may represent a subclinical marker of genetic susceptibility to ulcerative colitis. This study analysed P-ANCA in monozygotic twins with inflammatory bowel disease to evaluate this hypothesis further. P-ANCA was analysed with indirect immunofluorescence technique in 12 monozygotic twin pairs with ulcerative colitis and 14 twin pairs with Crohn's disease. Furthermore, the study included 21 non-twin patients with ulcerative colitis, 18 non-twin patients with Crohn's disease, and 52 healthy controls matched for sex and age. In ulcerative colitis P-ANCA occurred in nine of 14 (64.3%) monozygotic twins and in 13 of 21 (61.9%) non-twin cases, which was significantly different compared with healthy controls who were positive in three of 52 (5.8%) cases (p < 0.0001). P-ANCA was found in two of 10 (20%) healthy twin siblings to twins with ulcerative colitis, which was not significantly different from healthy controls (p = 0.18). The results in Crohn's disease did not differ from healthy controls. Previous findings of P-ANCA occurring in ulcerative colitis but not in Crohn's disease are supported. This study does not support the hypothesis that P-ANCA is a subclinical marker of genetic susceptibility to ulcerative colitis.

Adolescent↗

[Sensitivity of Plasmodium falciparum to seven antimalarials in China-Laos border].

The sensitivity of P. falciparum to chloroquine (CHL), piperaquine (PIP), artesunate (ATS), dihydroartemisinine (DAT), artemether (ATM), arteether (ATE) and pyronaridine (PRN) were assayed by in vitro microtechnique in China-Laos border in 1992. The resistance rates of isolates from the south of Yunnan of China in the border were 97.0%, 96.4%, 12.5%, 16.0%, 6.3% and 34.5%, respectively; ID50 were 119.0, 320.0, 7.2, 5.4, 295.0, 74.4 and 31.9 nmol/L, ID95 were 625.0, 2426.0, 42.2, 36.6, 767.0, 371.1 and 325.2 nmol/L. The resistance rates of isolates from the north border of Laos were in order 9/10, 8/10, 1/5 to CHL, PIP, PRN, ID50 were 114.0, 166.9, 16.4 nmol/L, ID95 were 570.0, 631.1 and 107.7 nmol/L. All the isolates from Laos were sensitive to ATS, DAT, ATM and ATE. ID50 were 5.0, 4.4, 91.6 and 56.7 nmol/L, ID95 were 23.4, 11.1, 3276.1 and 223.9 nmol/L, respectively. The results indicate that P. falciparum in the border was highly resistant to CHL and PIP, while most of the isolates were susceptible to the other 5 of the above-mentioned drugs. A comparison between the isolates from China and Laos showed that there was no significant difference in resistance degree to CHL but the sensitivity of isolates from China to other 6 drugs was lower than those from Laos.

Animals↗

[Induction of endogenous anti-IgE antibody of nasal mucosa and its inhibitive effects on IgE level].

The animals were immunized with IgEFc epsilon fraction which conjugated with keyhole limpet hemocyanin locally and systemically. The levels of anti-IgE, IgE and other four kinds of immunoglobulins were tested from the specimen of nasal mucosa, blood and spleen. The results showed that there were enhanced anti-IgE levels and depressed IgE levels, and there were no significant changes in the other four kinds of immunoglobulins after being immunized with IgEFc epsilon fractions. These effects continued until 14 weeks after immunization. These data demonstrate that there are possibilities to induce anti-IgE antibody in nasal mucosa locally and inhibit IgE antibody without significant side effects on the body.

Animals↗

[Reduction mammaplasty using glandular pedicle].

A new technique for reduction mammaplasty with a glandular pedicle was designed based on the anatomical study of the vascular supply to the breast. The features of the procedure include using a pyramidal glandular pedicle that is reliably vascularized and definitely placed, maintaining a thin layer of parenchyme attached to the flap and the modified invert "T" closure. Clinical applications provided aesthetic and safe results of reliable nipple-areola survival, simplicity in breast mound creature and preservation of nipple sensitivity and the possibility of nursing function as well as less complications.

Adult↗

[Immunocomplexes in tuberculous lesions].

The immunohistochemical staining was used to detect the BCG antigen, IgG, IgM, IgA and the complement C3 in the tuberculous lesions. The results showed that the III type of allergic reaction induced by immunocomplexes (IC) was one of the pathogenesis of tuberculosis. Detection of specific IC in tuberculous lesions was helpful for pathologic diagnosis of tuberculoions.

Antigen-Antibody Complex↗

[Dynamic obstruction of the left ventricular outflow tract by prosthesis dysfunction].

We report on a case of dynamic left ventricular (LV) outflow tract obstruction combined with a prosthetic valve dysfunction 13 years following mitral valve replacement with a Hancock bioprosthesis in a 46-year-old patient. Previously, repeated echocardiographic controls had been performed at regular intervals and the prosthesis had been found to be oversized and seated in abnormal position, with projection of the struts into the LV outflow tract. Moreover, a mild chronic LV outflow tract obstruction had been diagnosed upon intermittent findings of relatively high velocity in the outflow tract. Clinically, however, the patient had been stable and the function of the prosthesis had been good. With the onset of the mitral regurgitation due to prosthesis failure, a dynamic obstruction to LV outflow occurred, with severe narrowing of the LV outflow tract by a strut of the bioprosthesis during systole. Subsequently, a low cardiac output syndrome developed. The patient was referred for a mitral valve reoperation. The valve was replaced with a Sorin Bileaflet Carbon prosthesis. On the setting of a mild chronic LV outflow obstruction due to the oversized prosthesis and its abnormal position, hypercontractile cardiac function as a result of mitral regurgitation may have caused the dynamic and symptomatic LV outflow tract obstruction.

Bioprosthesis↗

[Chemical constituents of Hemsleya pengxianensis W.J. Chang].

Six compounds were isolated from the tubers of Hemsleya pengxianensis and identified as chikuset-susaponin IV a, hemslosides Ma1, G1, H1, dihydrocucurbitacin F-25-O-acetate and dihydrocucurbitacin F on the basis of chemical and physical properties and spectral data. They were all isolated from this plant for the first time.

Drugs, Chinese Herbal↗

[Anaesthesia for esophageal reconstruction with abdominal viscera in non-thoracotomy].

Radical resection of carcinoma of the hyopharynx and cervical esophagus usually involves pharyngolaryngo-esophagectomy and esophaged reconstruction with stomach or colonic replacement. From 1983 to 1994, 139 patients underwent the operations in our hospital. Although no thoracotomy, the extensive involvement of the neck, thorax and abdomen in the operation made the anesthesia difficult. There were 66 patients whose blood pressure dropped more than 3 kPa in the course of trans-mediastinum extraction of esophagus and gastric pull-up. There were injury of posterior wall of trachea in 2 patients and spleen rupture in 3. However, no anesthetic complications occurred during the operation.

Adult↗