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Biomedical subjects

Z Pan

Publications and source records attributed to Z Pan.

At least 91 records · Page 5Linked to original sources
PubMed1998

DNase I hypersensitive sites in the chromatin of the chicken Msx2 gene differ in anterior and posterior limb mesenchyme, calvarial osteoblasts and embryonic fibroblasts.

To identify candidate cis-acting regulatory regions involved in regulation of the Msx2 gene in anterior limb mesenchyme and calvarial osteoblasts, DNase I hypersensitive sites (DHSs) from -6.1 kb to +8.4 kb relative to the translation start site of the chicken Msx2 gene were identified in anterior and posterior limb mesenchyme, calvarial osteoblasts, and embryonic fibroblasts. A total of 12 DHSs were detected. Except for the DHS in the basal promoter region, none of the other DHSs were present in all four tissues, suggesting that the chromatin structure in the Msx2 gene locus is differently organized in these four cell types. One DHS was unique to Msx2 expressing cells and a second site to nonexpressing cells. Anterior and posterior limb mesenchyme had similar patterns of DHSs that were much more complex than observed in calvarial osteoblasts possibly reflecting differences in the complexity of Msx2 regulation in these two tissues.

Animals↗
PubMed1998

Effects of different subtypes of histamine receptors on proliferation and differentiation of murine colony forming unit granulocyte-macrophage and colony forming unit megakaryocyte.

OBJECTIVE: To investigate the function and characteristics of histamine receptors on the hemopoietic progenitor cells. METHODS: BDF1 mice (both male and female), inbred at our university, aged 8-12 weeks, weighing 20-24 g, were used in this study. Bone marrow cells were incubated for 1 hour at 37 degrees C with 2-AT (H1 receptor agonist) or impromidine (H2 receptor agonist) alone, or in combination with the antagonists pyrilamine or cimetidine respectively. Control experiment was performed in Dulbecco's modified Eagle's Medium (DMEM) alone. Cells treated with different drugs were performed by colony forming unit-granulocyte-macrophage (CFU-GM) and colony forming unit-megakaryocyte (CFU-Meg) assay. RESULTS: When bone marrow cells were treated with 10(-8) mol/L to 10(-5) mol/L of 2-thiazolylethylamine (2-AT) which had no influence on CFU-GM and CFU-Meg proliferation, 10(-8) mol/L to 10(-5) mol/L of impromidine could increase the number of CFU-GM and CFU-Meg colonies. The effects of H2 receptor agonists on CFU-GM, CFU-Meg could be antagonized by H1 receptor agonist. CONCLUSIONS: Our findings suggest the existence of histamine H1 and H2 receptors on the hemopoietic progenitor cells and the antagonism between two different histamine receptor subtypes on the proliferation of CFU-GM and CFU-Meg.

Animals↗
PubMed1998

[Histopathological study of local invasiveness of transglottic cancer].

OBJECTIVE: To explore the characteristics and relevant factors of transglottic cancer invading paraglottic space (PGS) and pre-epiglottic space (PES). METHODS: Whole-organ serial sections of 50 transglottic cancer specimens were studied histopathologically. RESULTS: Transglottic cancer invading PGS was observed in 39 of the 50 (78.0%) specimens. In 32 of the 39 specimens, the invasion outstripped PGS, involving elastic cone in 26(81.3%), thyroid cartilage in 24(75.0%) and cricothyroid membrane in 20(62.5%). Transglottic cancer invading PES was seen in 23 of the 50 specimens (46.0%). With the increase in tumor staging and tumor size, PGS and PES became increasingly invaded. There were two possible routes of invasion to PES: a) extending anteriorly and upward via PGS; b) extending upward via anterior commissure to destroy the stem of epiglottic cartilage. CONCLUSION: PGS is easily invaded by transglottic cancer. Partial laryngectomy is recommended in patients with T3, T4 transglottic cancer larger than 20 mm in diameter.

Adult↗
PubMed1998

[Transglottic carcinoma and transglottic invasion of laryngeal carcinoma].

OBJECTIVE: To explore the definition of transglottic carcinoma and its pathological characteristics of local invasion, and to determine the distinction between transglottic carcinoma and transglottic invasion of laryngeal carcinoma. METHODS: Fifty total laryngectomy specimens of transglottic carcinoma were subject to whole-organ serial section, HE staining and microscopic observation. RESULTS: The ventricles of 50 cases were all invaded, the main lesion of carcinoma was in the ventricle, or the ventricle was the center of the lesion. The rate of invasion to paraglottic space(PGS) was 82%(41/50). Submucosal invasion was seen in 52%(26/50) and that with superficial mucosal invasion was seen in 38%(19/50). Superficial mucosal invasion rate was 10%(5/50). Deep submucosal invasion was the major way of tumor spread in transglottic carcinoma which equally involved the supraglottic and glottic regions. CONCLUSION: Transglottic carcinoma originates from the center of ventricle where it spreads to transglottic region. Submucosal extension is characteristic of local invasion. There are fundamental differences between transglottic carcinoma and transglottic invasion of laryngeal carcinoma in the late stage of the lesion.

Adult↗
PubMed1998

[TGF beta subtypes in hepatocellular carcinoma].

OBJECTIVE: To detect the expression of three TGF beta isoforms and its clinicopathologic significance in hepatocellular carcinoma(HCC). METHODS: Surgical specimens of 52 patients with small HCC resection during 1992-1995 were used to determine the immunoreactivity of TGF beta protein by ABC immunohistochemistry. These specimens were divided into recurrence group(G1) and recurrence group(G2) according to whether HCC recurred two years after resection. The relations with recurrence of HCC were analyzed. RESULTS: The positive rates in G1 and G2 were 85% (17/20) versus 47% (15/32) for TGF beta 1, 90% (18/20) vs. 78% (25/32) for TGF beta 2, and 45% (9/20) vs. 63% (20/32) for TGF beta 3. Significant difference was found in TGF beta 1 and TGF beta 2, but not in TGF beta 3. CONCLUSION: The high immunoreactivity to TGF beta 1 or TGF beta 2 is positively related to the recurrence of HCC.

Adult↗
PubMed1998

[Investigation of the clinicopathologic features, immunophenotype and Epstein-Barr virus infection of the upper respiratory tract lymphomas in patients].

OBJECTIVE: To study the clinicopathologic features, immunophenotype and Epstein-Barr virus (EBV) infection of the upper respiratory tract lymphomas in patients from north China. METHODS: 112 cases of upper respiratory tract lymphomas in patients from north China were investigated. HE stain for histologic features. Immunohistochemistry studies were performed using monoclonal antibodies, UCHL-1 for T-lymphocyte, L26 and 4KB5 for B lymphocyte, CS1-4 for latent membrane protein-1 (LMP-1). In situ hybridization for EBV encoded small nuclear RNA (EBER 1/2, Y017, DAKO). RESULTS: 77/112 cases (68.75%) were T-cell lymphomas, 35 cases (31.25%) were B cell lymphomas. EBV-EBER 1/2 in situ hybridization positive in 54/101 (53.46%) cases, including 48 T-cell lymphoma cases and 6 B-cell lymphoma cases. CONCLUSION: Most upper respiratory tract lymphoma cases in patients from north China are T-cell lymphomas and are strongly associated with EBV.

Adolescent↗
PubMed1998

Glycophorin variants and contents of sialic acid and total sulfhydryl groups on erythrocyte membranes of residents in a malaria hyperendemic area.

OBJECTIVE: To conduct a screening survey of glycophorin (GP) variants and observe the content changes of sialic acid (SA) and total sulfhydryl (SH) groups on the erythrocyte membranes among residents in a tertian malaria hyperendemic area of Guizhou Province. METHODS: GP variants were detected in the erythrocyte hemolysates of 173 local residents at two villages of Libo County by SDS-PAGE on 10% to 15% gradients gel and Western immunoblotting. Their SA and total SH group contents were estimated in erythrocyte membranes by spectrophotometric methods. 114 healthy subjects in Changsha and 49 individuals at a neighbouring village of the above area showing low morbidity of malaria served as normal and endemic controls respectively. RESULTS: Three distinct types of GP variants were found among 19 propositi in this hyperendemic area. The incidence of GP variants was 7.9% (8/101) at Yaolu Village whose population was mainly composed of Yao ethnic group; while that of Buyi ethnic group at Maolan Village was higher (15.3%; 11/72). The erythrocyte membrane contents of SA in residents at both villages exhibited a very significant tendency of decline (P < 0.01), whereas those of total SH groups increased prominently in residents of Yaolu Village only (P < 0.05). CONCLUSIONS: The frequency of GP variants in this hyperendemic area does not depend upon the severity of malarial prevalence. The evident reduction of SA contents in the residents may be related to the breaking down of the SA residues on membrane GPs by the invasion of Plasmodium vivax.

Adolescent↗
PubMed1998

[Cerebrospinal aporrhinosis of nasal sinus operation].

OBJECTIVE: To study the treatment of cerebrospinal aporrhinosis after nasal sinus operation, especially frontal, ethmoid tumor resection. METHODS: Fourteen cases of cerebrospinal aporrhinosis after nasal sinus operations were reported. RESULTS: Seven cases of cerebrospinal apporrhinosis were found during the operation. Two cases were repaired with tensor facia latae, 3 with mucosoperichondrium of nasal septum and EC otocerebral glue and 1 with TJ bone cement. Seven cases cerebrospinal aporrhinosis were found after the operations when intranasal packing was removed. They were cured by cerebral decompression and antibiotics, none complicated with intracranial infection. CONCLUSION: Careful examination should be taken daring the operation. If aporrhinosis was found, it should be repaired immediately.

Adolescent↗
PubMed1998

[Quality control for huoxiang-zhengqi liquid].

The Rhizoma Atractylodis, Cortex Magnoliae Officinalis and Pericarpium Citri Reticulatae in Huoxiang-zhengqi Liquid were identified by TLC. The total contents of magnolol and honokiol were determined by HPLC to be no less than 1.9 mg/ml, with an average recovery of 104.4% and 103.3%, RSD 1.23% and 0.91% respectively.

Asteraceae↗
PubMed1998

[Laryngeal reconstruction after near-total laryngectomy].

OBJECTIVE: To reduce the rate of near-total laryngectomy and reconstruct laryngeal function. METHOD: A retrospective review was made on 19 patients treated by near-total laryngectomy and laryngeal reconstruction from 1991 to 1996. Eight patients were male and 11 were female. The age range was from 40 to 74 years, with a mean age of 57.6. Two cases were in stage II, 9 cases stage III, 8 cases stage IV. The characteristic of this operation is to remove hyoid bone and reduce aspiration. RESULTS: Speech function in all patients was good. Deglutition in most patients was good. Five patients breathed through the larynx after decannulation. Fourteen patients respired through tracheostoma because of stenosis of laryngeal cavity. Among them, 10 cases did not need cannula for their wide tracheostomas, 4 cases needed cannula. Three-year survival rate was 78.6%(11/14), 5-year survival rate was 75%(3/4). CONCLUSION: Laryngeal reconstruction near-total laryngectomy is helpful to restore laryngeal function and decrease the rate of total laryngectomy.

Adult↗
PubMed1998

[Establishment of hybridoma secreting anti-mycobacteria monoclonal antibody by using electrofusion technique].

By using the electrofusion technique, the fusion of NS1 myeloma cells with spleen cells of BALB/c mouse immunized with five species of mycobacteria was carried out. With the optimal electrofusion conditions, we obtained a high fusion efficiency of 1.75 hybrid cell clones per 10(5) spleen cells. ELISA was used for screening secreting antimycobacteria McAb hybrid cells. After cloning, 22 stable hybrid cells lines were selected, and 8 of them had been studied.

Animals↗
PubMed1997

Identification of two nervous system-specific members of the erg potassium channel gene family.

Two new potassium channel genes, erg2 and erg3, that are expressed in the nervous system of the rat were identified. These two genes form a small gene family with the previously described erg1 (HERG) gene. The erg2 and erg3 genes are expressed exclusively in the nervous system, in marked contrast to erg1, which is expressed in both neural and non-neural tissues. All three genes are expressed in peripheral sympathetic ganglia. The erg3 channel produces a current that has a large transient component at positive potentials, whereas the other two channels are slowly activating delayed rectifiers. Expression of the erg1 gene in the sympathetic nervous system has potential implications for the etiology of the LQT2 form of the human genetic disease long QT syndrome.

Animals↗
PubMed1997

Intermittent on/off prostaglandin E2 and risedronate are equally anabolic as daily PGE2 alone treatment in cortical bone of ovariectomized rats.

In this study, we evaluated the rat cortical bone changes after a two-cycle, 60-day each (ON/OFF/ON/OFF) treatment with either prostaglandin E2 (OVX/c-PGE2) alone or in combination with risedronate (OVX/c-PGE2+Ris), in comparison with daily treatment with PGE2 for 240 days (OVX/PGE2-240d) in ovariectomized (OVX) rats. At the end of the study, we found that: (1) the overall effectiveness of the treatment on bone mass in the tibial shaft indicates the following ranking: OVX/PGE2-240d = OVX/c-PGE2+Ris > OVX/c-PGE2 > OVX/c-Ris > or = OVX = aging; (2) the same bone mass and architecture were produced in the OVX/PGE2-240d and the OVX/c-PGE2+Ris groups, but the histomorphometric profiles differed in that the former exhibited a higher bone turnover and index of resorption; (3) OVX/c-PGE2+Ris treatment prevented endocortical bone loss and minimized trabecular bone loss during the OFF periods; and (4) the OVX/c-PGE2 alone treatment resulted in the accumulation of less total bone than OVX/PGE2-240d and OVX/c-PGE2+Ris because it could not maintain most of the new subendocortical and marrow trabecular bone generated earlier. In summary, both continuous daily PGE2 and two cycles ON/OFF combined PGE2 and Ris treatments result in more bone mass than two cycles ON/OFF PGE2 alone and Ris alone in estrogen-deficient rats. This study showed that the anabolic effects of PGE2 can be induced and maintained either by continuous administration or by cyclical PGE2+Ris.

Animals↗
PubMed1997

The role of the T-lymphocyte in estrogen deficiency osteopenia.

Our laboratory has previously demonstrated that the T-lymphocyte is critical in the development of cyclosporin A-induced osteopenia in the rat model. A similar state of osteopenia is induced by estrogen depletion in the ovariectomized (OVX) rat, which is the animal model of postmenopausal bone loss. However, the role of the immune system, and particularly the T-lymphocyte, in estrogen deplete osteopenia has not been elucidated. We used the Rowett athymic nude rat as our model of T-lymphocyte deficiency. In this study, the experimental rats were divided into four groups as follows: (1) sham-operated Rowett heterozygous (rnu/+) euthymic rats (control group); (2) OVX Rowett heterozygous (rnu/+) euthymic rats; (3) sham-operated Rowett homozygous (rnu/rnu) athymic nude rats, which are T-lymphocyte deficient; and (4) ovariectomized Rowett homozygous (rnu/rnu) rats. Rats were weighed, and venous blood was taken in weeks 2, 4, and 6 for determination of serum osteocalcin. Serum 1,25-dihydroxyvitamin D (1,25(OH)2D) was determined on the day of sacrifice. Following sacrifice, histomorphometry was performed on double-labeled proximal tibial metaphyses. Flow cytometric analysis of splenic mononu-clear cell isolates stained for OX19-positive (CD5) T-lymphocytes was performed. T-lymphocyte analysis revealed significant reductions in both athymic nude groups, while OVX euthymic rats demonstrated a diminished number of T-cells relative to their sham-operated counterparts. Histomorphometric data indicated that both OVX groups exhibited a significant loss of trabecular volume, with associated increases in indices for bone formation and resorption, with resorption likely outstripping formation, resulting in osteopenia. Serum osteocalcin was significantly elevated in the ovariectomized euthymic group throughout the experimental period compared with the control group (p < 0.01); it was elevated in the ovariectomized athymic group on week 4 only (p < 0.01 vs. control). It appears that the T-lymphocyte may not be an essential component in the pathogenesis of estrogen deficiency osteopenia. The contribution of circulating T-lymphocytes as well as other T-lymphocyte-rich organs needs to be explored further.

Animals↗
PubMed1997

[Improvements of laryngectomy cricopharyngeal anastomosis laryngeal reconstruction (report of 27 cases)].

To alleviate the deglutition and increase decannulation rate in Arslan's operation, 27 patients who had undergone laryngectomy cricopharyngeal anastomosis reconstruction from 1989 to 1995 in our hospital were reported. There were T1bN0 8 cases, T2N0 17 cases, T3N0 2 cases according to UICC staging in 1987. All lesions located in vocale cords bilaterally. On the side of the mild lesion, over half of the vocale cord was invaded. The main points of surgical procedure were that the epiglottic and cricoid cartilage were restored. Hyoid bone and arytenoid cartilages were resected and cricoid cartilage anastomosis with the base of the tongue and submental muscles. Phonation was restored in all postoperative patients. Deglutition was alleviated significantly. Decannulation rate was 92.6% (25/27). The follow-up period of 14 cases was over 3 years. Of the 14 cases, 1 died. The 3 years survival rate was 92.86% (13/14). The follow-up period of 6 cases was over 5 years. Of the 6 cases, 1 was lost, the 5 years survival rate was 83.33% (5/6). The operation has great effects on alleviating deglutition and increasing decannulation rate.

Adult↗
PubMed1997

[Histopathological study of local invasion and cervical lymph node metastasis in transglottic carcinoma].

To study the histopathological characteristics of local invasion and cervical lymph node metastasis in transglottic carcinoma and provide theoretical guide to clinical practice, 30 laryngectomy and 35 neck dissection specimens were studied by serial section, HE staining and observation under light microscope. The results showed that transglottic carcinomas originated from the ventricle invaded supraglottic and glottic areas equally. The metastatic rate of cervical lymph nodes was 43.3%; the latent metastatic rate was 30%. The metastatic and extracapsular perforation rates as well as the number of the aggregated fusion lymphnodes increased with the increase in the size of the lymphonodes. It was concluded that the transglottic carcinoma should be defined as one with the main lesion locates in the ventricle, or the ventricle being the center with transglottic spread. Since the barrier of ventricle was weak, partial laryngectomy should be performed with care, and ipsilateral neck dissection shoud be included during operation.

Adult↗
PubMed1997

[A report of 50 cases of transglottic carcinoma].

50 cases of transglottic carcinoma were chosen and the collodion-embedded specimens of whole-organ serial section were observed. We found that: 1. Transglottic carcinoma was of laryngeal ventricle origin; 2. There were 1 case in T1 and 2 cases in T2 category; 3. Deep infiltration was the main local growth pattern (90%, 45/50), and paraglottic space and thyroid cartilage were easily involved (82%, 41/50 and 65%, 32/50 respectively), clinical stage was not parallel to pathological stage (48%, 24/50).

Adult↗