Biomedical subjects

G Chen

Publications and source records attributed to G Chen.

At least 415 records · Page 23Linked to original sources

PubMed1999

[In vitro proliferation and differentiation of bone marrow stem cells of aplastic anemia patients].

OBJECTIVE: To investigate the quality of bone marrow stem cells from aplastic anemia patients and their in vitro responses to hemopoietic growth factors(HGF). METHODS: CD34 positive bone marrow cells from 10 chronic aplastic anemia(CAA), 5 severe aplastic anemia(SAA) patients and 5 healthy subjects were detected with immunoflurescence assay, enriched by Panning way, and then cultured in vitro for CFU-GM, BFU-E and CFU-E in the presence of recombinant HGFs. RESULTS: CD34 positive rates of the bone marrow mononuclear cells(MNC) of CAA, SAA and control groups were (1.05 +/- 0.51)%, (0.70 +/- 0.37)% and (1.27 +/- 0.45)%, respectively, and there was no difference among them (P > 0.05). After being enriched, CD34 positive cells in MNC of CAA, SAA and control groups increased to a similar level(P > 0.05). In the presence of G-CSF or GM-CSF, the enriched CD34 positive MNC of CAA and SAA patients formed similar CFU-GM number to those of normal controls. The numbers of BFU-E and CFU-E formed from the enriched CD34 positive MNC of CAA and SAA patients were also the same as that of normal control groups under the stimulation of erythropoietin and interleukin-3. Stem cell factor could cooperate with G-CSF, GM-CSF, and erythropoietin significantly increasing the numbers of CFU-GM, BFU-E and CFU-E of CAA, SAA and normal control's enriched CD34 positive MNC. CONCLUSION: The bone marrow CD34 positive cells from aplastic anemia patients appears to be normal in percentages and in in vitro proliferation/differentiation capacities.

Adolescent↗

PubMed1999

[Expression of c-kit receptor on the hemopoietic stem/precursor cells of aplastic anemia patients].

OBJECTIVE: To explore the expression of c-kit receptor(CD117) on the hemopoietic stem/precursor cells of aplastic anemia patients and its role in the genesis of aplastic hematopoiesis failure. METHODS: c-kit expression on the bone marrow mononuclear cells(MNC) and CD34 positive cells from 11 chronic aplastic anemia (CAA), 9 severe aplastic anemia(SAA), 10 non-aplastic anemia(NAA) patients (5 iron deficiency anemia and 5 autoimmune hemolytic anemia) and 5 healthy controls was measured with flow cytometric immunofluorescence assay and anti-CD117 monoclonal antibody. RESULTS: The CD117 positive rates of MNC in CAA, SAA, NAA and control groups were (2.08 +/- 1.96)%, (0.89 +/- 0.32)%, (0.67 +/- 0.39)% and (0.45 +/- 0.16)%, respectively, and the rates were significantly higher in CAA and SAA groups than in NAA and control groups(P < 0.05). The CD117 and CD34 double positive cells of MNC in CAA, SAA, NAA and control groups were (0.87 +/- 0.57)%, (0.65 +/- 0.41)%, (0.46 +/- 0.26)% and (0.41 +/- 0.15)%, respectively, and were significantly higher in CAA and SAA groups than in NAA and control groups (P < 0.05). The CD117 positive cells of CD34 positive cells were also higher in CAA[(71.6 +/- 12.4)%] and SAA[(88.9 +/- 23.5)%] groups than in NAA[(41.8 +/- 10.3)%] and control [(46.3 +/- 9.7)%] groups (P < 0.01). CONCLUSION: Hemopoietic stem/precursor cells of aplastic anemia patients expressed more c-kit receptors than those of NAA patients and healthy controls. The hematopoiesis failure occurred in aplastic anemia is not attributed to low expression of c-kit receptor on the hemopoietic stem/precursor cells.

Adolescent↗

PubMed1999

[Diagnosis and treatment of early gastric cancer: an experience from 61 cases].

OBJECTIVE: To review the clinical signs of diagnostic significance and treatment of early gastric cancer. METHODS: Sixty-one gastric cancer patients were collected for this study. They were surgically treated and pathologically confirmed to be in the early stage of disease. The x-ray and gastroscopic findings of these patients were reviewed. RESULTS: Double-contrast barium meal examination was performed in 46 cases and 27 of them were diagnosed as gastric cancer with a detection rate of 58.7%. Superficial type of tumor was easily misdiagnosed as superficial gastritis and concave type of tumor misdiagnosed as benign gastric ulcer under x-ray imaging. All the patients were gastroscopically examined. With examiner's naked eyes, diagnosis of cancer was made in 27 cases (44.3%). Visual diagnosis was difficult when the tumor was small. Attention should be focused on the gastric incisura angularis, antrum and lesser curvature to perform site-directed biopsy. Final diagnosis depended on the pathological diagnosis of the biopsied materials. Pathologic diagnosis would be correct provided the biopsy material was taken from the proper site. It was correct in 58 of the 61 cases (95.1). Surgical treatment consisted of radical gastrectomy and D2 lymph node dissection. All but 2 were tumor free after surgical treatment. Prognosis was good in this series of early gastric cancer patients, 38 of them were alive over 5 years and 12 patients survived over 10 years. CONCLUSION: Careful x-ray and gastroscopic examinations of patients with epigastric symptoms are indicated not to miss any early case of gastric cancer.

Adult↗

PubMed1999

[Glutathione synthesis inhibitor enhances arsenic trioxide-induced apoptosis].

OBJECTIVE: To illustrate the possible role of thiols (SH-groups) in arsenic trioxide (As2O3)-induced apoptosis. METHODS: Leukemia (NB4, HL60, U937) and lymphoma (Jurkat and Namalwa) cell lines were treated with As2O3 together with buthionine sulfoximine (BSO), a selective inhibitor of gamma-glutamylcysteine synthetase. The mitochondrial transmembrane potentials (delta psi m) and the percentage of cells in apoptosis were measured by means of flow cytometry. RESULTS: One mmol/L BSO significantly enhanced As2O3-induced delta psi m collapse and apoptosis in NB4 cells. One mumol/L As2O3 did not induce the delta psi m collapse and apoptosis in Namalwa, HL60, U937 and Jurkat cells, while these effects were induced significantly by the co-treatment of 1 mumol/L As2O3 and 1 mmol/L BSO. CONCLUSION: Thiols are important chemosensors of As2O3-induced delta psi m collapse and apoptosis.

Apoptosis↗

PubMed1999

[Local resection of carcinoma of ampulla of Vater: an analysis of 52 cases].

OBJECTIVE: To study the therapeutic results of patients with carcinoma of ampulla Vater treated by local tumor resection. METHODS: Four cases of carcinoma of ampulla of Vater treated in our hospital by local tumor resection and 48 cases reported in Chinese medical literature in 1992-1997 were analyzed. RESULTS: A total of 52 cases was collected who received local resection of carcinoma of ampulla of Vater. The operative mortality was 3.8% and the morbidity was 9.6%. Recurreuce occurred in 12 cases, of whom 3 had poorly differentiated adenocarcinoma, 7 had their tumor incompletely resected with tumor left at the cutting edge and one had local invasion. In 8 month to 4 years, 19 cases died. Thirty two cases survived for 7 months to 8 years after operation. CONCLUSION: The prognosis of local resection is related not only to tumor size, extent of invasion, metastasis to lymph node, but also to pathologic types and differentiation. It is a treatment of choice for early carcinoma of ampulla of Vater in patients who are at high-risk due to old age, poor general condition or severe concurrent diseases.

Adult↗

PubMed1999

[Clinical and experimental studies on huodan tablet in treating pediatric viral myocarditis].

OBJECTIVE: To study the effect of Huodan Tablet in treating pediatric viral myocarditis. METHODS: Clinical manifestations and physical signs as well as laboratory examinations have been observed. RESULTS: The markedly effective rate was 68%, the total effective rate was 91.67% in therapeutic group, while in control group, the markedly effective rate was 30.83% and the total effective rate 70.84%. According to Ridit analysis, significant difference was shown between the two groups. r-therapeutic group = 0.5000, r-control group = 0.295 + 2 x 0.025, respectively. CONCLUSION: Huodan Tablet has no toxic and side-effect and can be taken safely and conveniently, it complies with the demands of WHO on new drug for prevention and cure of myocarditis.

Adolescent↗

PubMed1999

[Effect of baicalin and tetramethylpyrazine on intracranial hypertension of infectious brain edema in rabbits].

OBJECTIVE: To evaluate the effects of mannitol (MN), baicalin (BC) and tetramethylpyrazine (TMPZ) on intracranial hypertension (ICH) of infectious brain edema induced by Pertussis bacilli (PB) in rabbits. METHODS: Forty-five rabbits were divided randomly into five groups: the normal saline group (A); the pertussis bacilli group (B); the MN treated group (C); the TMPZ treated group (D) and the BC treated group (E). PB was injected into the left internal carotid artery of rabbits to establish the infectious brain edema model, their intracranial pressure (ICP) was monitored continuously by fiberoptic ICP monitor. Treatments were given intravenously 1 hour after injecting PB, and changes of ICP, brain water content (WC), Evans blue (EB), Na+, K+ and morphology were observed within 4 hours after PB or NS injection. RESULTS: MN, TMPZ and BC all could reduce the brain edema and ICH in rabbits induced by PB, the effect of MN was the most rapid and obvious one, but it lasted for rather shorter time, while the effect of TMPZ and BC was initiated later but lasted for a longer time. The ICP of Group C in 2nd to 4th hour was higher than that of Group D and Group E, but lower than that of Group B. The ICP of Group E in 3rd to 4th hour was lower than that of group D. At the same time of lowering ICP, brain WC, EB, Na+ contents and pathologic morphologic change were also alleviated. CONCLUSION: Both BC and TMPZ could reduce ICP in infectious brain edema, the effect of BC was better than that of TMPZ.

Animals↗

PubMed1999

[Clinical analysis of 12 cases of Chinese patients with adult T-cell leukemia/lymphoma].

OBJECTIVE: To define the clinical characteristics and differential diagnosis in Chinese patients with adult T-cell leukemia/lymphoma (ATLL) and its relation to human T lymphotropic virus type-1 (HTLV-1) infection. METHODS: Lymphocyte morphology in peripheral blood was examined in smears by Cytospin II. Lymphocyte immunophenotyping was carried out by indirect immunofluorescence method. HTLV-1 antibody was detected by indirect immunofluorescence method, proviral DNA detected by PCR method and PCR products demonstrated by Southern Blot analysis. RESULTS: The clinical manifestations in these 12 patients were fever (10/12), lymphadenopathy (8/12), skin changes (7/12), spleen and liver enlargement (7/12), jaundice (3/12), pleural effusion (1/12) and lung invasion (1/12). Patul-like cells were not easily found in routine blood smears, but easily found with Cytospin II (10/10). There was increase in lactic dehydrogenase (8/9) and soluble interleukin 2 receptor (9/9). Anemia (7/12), thrombocytopenia (6/12), pancytopenia (2/12), myelodysplasia (4/12) and eosinophilia (8/12) can be found, but no hypercalcemia. HTLV-1 antibody and proviral DNA were positive in 6/10 cases and 9/12 cases respectively. Nine cases were classified as acute type and three as lymphoma type. All patients were misdiagnosed as other diseases at the beginning. The initial presentations were skin changes (4/12), lymphadenopathy (3/12), myelodysplasia (3/12), progressive liver enlargement (1/12) and refractory pleural effusion (1/12). The complications were infections by undetermined pathogens (6/12), Streptococcal infection (1/12), gastrointestinal bleeding (3/12), acute renal failure (3/12), acute respiratory failure (2/12) and cerebral hemorrhage (1/12). Seven patients died, three still survive, and two are out of contact. CONCLUSION: ATLL may not be very rare in China. It is necessary to deepen the recognition of ATLL in Chinese.

Adult↗

PubMed1999

[The alteration of microsatellite DNA in lung cancer].

OBJECTIVE: To study the alteration of microsatellite DNA in primary lung cancer and its value of diagnosis for lung cancer. METHODS: Five microsatellite markers on chromosome 3P13-26 have been examined in 50 primary lung cancer tissues and their normal lung tissues. RESULTS: In fifty lung cancer, the incidence of microsatellite instability (MSI) was 52% (26/50) and the loss of heterozygosity (LOH) 38% (19/50). The positive rate of MSI in poorly differentiated lung cancer (13/17, 77%) was significantly higher than that in well, moderately differentiated (10/28, 36%). The sensitivity in the diagnosis of lung cancer was 72% by combining MSI and LOH. CONCLUSIONS: MSI and LOH may play a certain role in the carcinogenesis and progression of lung cancer and they may be valuable molecular markers in diagnosis of lung cancer.

Adult↗

PubMed1999

[Clinical protocols for the treatment of severe acute pancreatitis].

OBJECTIVE: To set up principles for the treatment of severe acute pancreatitis (SAP). METHODS: The therapeutic principles and results of SAP in three periods were analyzed. Period I (1980 - 1990) was characterized by early surgical intervention supplemented with integrated traditional and western medical therapy, period II (1991 - 1993) by integrated traditional and western medical therapy supplemented with surgery for early complications, and period III (1994 - 1997) by integrated traditional and western medical therapy supplemented with surgery for local infectious complications only. RESULTS: Because of the improvement of intensive care, the operation rates kept declining in the three periods. They were 77.59%, 54.55% and 29.55% with a mortality rate of 40.52%, 17.17% and 11.36%, respectively. CONCLUSIONS: Integrated traditional and western medicine has been effective in most SAP patients, and surgery is indicated only for late complications such as necrotizing infection. Early surgery should be restricted.

Adolescent↗

PubMed1999

[Plasminogen activator inhibitor-1 mRNA expression by the iris and lens epithelial cells of rabbit eye with intraocular lens implantation].

OBJECTIVE: To investigate the change of plasminogen activator inhibitor-1 (PAI-1) synthesized by the iris and the lens epithelial cells (LECs) after extracapsular cataract extraction (ECCE) with intraocular lens (IOL) implantation and the role of PAI-1 in the occurrence of fibrin reaction and the formation of posterior capsular opacification. METHODS: Eight adult rabbits were studied. In each rabbit, one eye underwent ECCE with IOL implantation and the other eye was normal without any surgical intervention. The iris tissue and the lens capsule of each two normal eyes and each two surgical eyes were excised on the postoperative 1, 7, 15 and 30 days respectively. The amount of PAI-1 mRNA expression in the specimens was detected by using reverse transcription-polymerase chain reaction (RT-PCR). The data were analyzed statistically. RESULTS: The amount of PAI-1 mRNA expresson in the iris tissue and the LECs of the surgical eyes displayed a significant increase on the first day after operation. The high expression of PAI-1 mRNA by the iris might last 15 days (P < 0.001), but it declined to the normal range on the postoperative 30 days (P = 0.87). The high level of PAI-1 mRNA expresson by the LECs in the surgical eyes had significant difference when compared with that of the normal eyes at 1, 7, 15 and 30 days postoperatively (P < 0.001). CONCLUSION: It is indicated that PAI-1 enzyme is a major cause for fibrin reaction after ECCE with IOL implantation, and may play critical roles in the development of posterior capsular opacification.

Animals↗

PubMed1999

[The significance of pattern electroretinogram in detecting retinal function in primary open angle glaucoma].

OBJECTIVE: To evaluate the clinical significance of pattern electroretinogram (PERG) in primary open angle glaucoma (POAG). METHOD: Thirty-six patients (59 eyes) with POAG and 32 persons (59 eyes) as age-matched normal controls were tested by PERG. RESULTS: The changes of PERG in POAG included reduction of amplitudes of P(1), N(2), P(1) + N(2) and N(2)/P(1). Using the criteria of AN(2) + AP(1) < 2.7 and AN(2)/AP(1) < 0.7 (A = amplitude), the positive rate was 90% in 59 eyes with POAG, and no eye from the normal control group was considered as abnormal. The amplitudes of PERG had already been abnormal before the early visual field loss occurred in POAG eyes. The amplitudes of P(1) and N(2) waves decreased with the enlargement of visual field defect, were positively correlated to the patient's visual acuity and negatively correlated to the cup/disc ratio of optic nerve papilla, and linear regression equations between them were respectively established. CONCLUSION: PERG is an useful method in detecting the retinal functions in POAG.

Adult↗

PubMed1999

[Establishment of a heterologous graft model for human breast infiltrating duct carcinoma in nude mice].

A heterologous graft model for human breast infiltrating duct carcinoma is reported in this paper. The grafts derived from an infiltration duct carcinoma of a patient's right breast and her metastatic lymphnode mass were transplanted into the breast pads of nude mice in 1996, and the carcinoma masses were found in breast pads 31 days later. By now, the grafts of carcinoma have been transplanted into nude mice for 15 passages with a full success in 59 mice and with the biological characteristics of the original breast carcinoma. This heterologous graft model was established for the first time in China and the results suggest it be a good model for further research of breast carcinoma.

Animals↗

PubMed1999

[A dynamic study of influences of TMJOA on TMJ disc].

OBJECTIVE: To learn the changes of TMJ disc positions under the influences of TMJ Osteoarthrosis(TMJOA). METHODS: The TMJOA experimental animal model was established by 12 goats. The TMJ disc positions were observed and recorded at different intervals, (1 month, 2 months, 3 months, 4 months and 6 months) then the pathological changes of TMJ specimens were also studied. RESULTS: Significant anteromedial shift of TMJ disc position was observed in some certain TMJOA phases and became more obviously along with the disease progress. CONCLUSION: The shift of TMJ disc may be the secondary change of TMJOA.

Animals↗

PubMed1999

[Three-dimensional finite element analysis of stress in supporting bone of mandibular posterior fixed bridge. I. Stress analysis of the surface of alveolar bone around bridge abutments].

OBJECTIVE: Stress levels of the surface of alveolar bone around bridge abutment of posterior fixed bridge were studied. METHODS: The three-dimensional finite element model was developed on the basis of a try adult mandible. 6 vertical and 1 horizontal loadings were applied respectively, and the Maximum stress(epsilon max) and the Minimum stress(epsilon min) of the surface of alveolar bone around bridge abutment were calculated. RESULTS: The stress concentration exhibited at the apical and cervical regions. The stress of the bicuspid was about 2.1 times as high as that of the molar. When transverse loading was applied, the stress level was about 3.5 times as high as that when vertical loading was applied. CONCLUSION: The results were greatly valuable to design of posterior fixed bridge.

Alveolar Process↗

PubMed1999

[Three-dimensional finite element analysis of stress in supporting bone of mandibular posterior fixed bridge. II. Stress distribution of the cortical bone beneath pontic of fixed bridge].

OBJECTIVE: Stress distribution of the cortical bone beneath the pontic of the fixed bridge was observed. METHODS: The three-dimensional finite element model was developed. 6 loadings were applied respectively and the Maximum Stress (epsilon max) and the Minimum Stress(epsilon min) of the cortical bone beneath the pontic of the fixed bridge were calculated. RESULTS: The stress values were very small before the bridge was inserted. After the bridge was inserted the stress increased, but the stress level in the cortical bone was much lower than that in the alveolar bone. The stress values of the cortical bone were only 9.5% (vertical loading) and 2.2% (horizontal loading) of the alveolar bone's. CONCLUSION: The stress value of the cortical bone beneath the pontic was very small. The load was born mainly by supporting tissue around the bridge abutment.

Alveolar Process↗

PubMed1999

[The investigation on nitric oxide levels in saliva and their relationship with the severity of periodontitis].

OBJECTIVE: To study nitric oxide levels in saliva of patients with periodontitis and the relationship between nitric oxide levels and the severity of periodontitis. METHODS: Samples of saliva from 23 adult subjects with periodontitis and 27 healthy control subjects were collected at their first appointment. Data of gingival bleeding index (GBI), pocket depth (PD) and attachment level (AL) were recorded. Salivary nitrite was detected with Greiss method, which stood for the content of nitric oxide (NO). RESULTS: It was found that NO in saliva of patients with periodontitis were significantly higher than that in saliva of healthy individuals (P < 0.01). The levels of NO were 55.361 +/- 13.319 mumol/L and 28.806 +/- 6.604 microns/L in saliva with periodontitis and control respectively. Significant relationship was found between AL and salivary NO level (P < 0.02) and between PD and salivary NO level (P < 0.05). CONCLUSION: The change of salivary NO level is related with periodontitis.

Adult↗

PubMed1999

[A comparative study of three-dimensional movements of lumbar spine in the old and the young people].

This article is aimed at the differences in lumbar vertebral three-dimensional movement and in stability between the old and the young people, and at the reasons which lead to the differences. Fifteen fresh adult male cadavers were divided into two groups: the young group, 20-30 years old, comprising 7 cases; the old group, 60-70 years old, 8 caes. Lumbar spine(L1-S1) was cut down. Three-dimensional movements under a loading system were measured by a compute system. The result showed that the range of the motion of the old group was lower than that of the young group. It suggests that the lumbar spine of the old people is more stable than that of the young people. This may be associated with the degeneration of the lumbar vertebra, which arouses biocompensatory changes, so the lumbar spine becomes re-stable.

Adult↗