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Biomedical subjects

J Yang

Publications and source records attributed to J Yang.

At least 343 records · Page 19Linked to original sources
PubMed2001

Biological features of mesenchymal stem cells from human bone marrow.

OBJECTIVE: To study the biological characteristics of mesenchymal stem cells (MSCs) from human bone marrow. METHODS: A culture of mesenchymal stem cells was initiated from bone marrow low-density mononuclear cells separated by Percoll Centrifugation and maintained in low-glucose Dulbecco's modified Eagle's medium (DMEM) with 10% selected fetal calf serum. Cell growth pattern and its responses to cytokines were evaluated by trypan blue exclusion and MTT test, respectively. Cell cycle and surface antigenic features were analyzed by flow cytometry technique. Cytochemistry characteristics of MSCs were determined. RESULTS: Easy-handling methods to isolate and culture expand MSCs were developed in this study. MSCs were unique in their phenotypes. They were positive for CD29, CD44, CD166, and negative for CD34, CD45, HLA-DR and Ulex europaeus. Cytochemistry evaluation showed that MSCs were homogeneously positive for acid alpha-naphthl acetate esterase (ANAE), glycogen (periodic acid Schiff reaction, PAS), and negative for acid phosphatase (ACP) and the Sudan black reaction (SB). Around 5% of them were positive for alkaline phosphatase (ALP). The cells had a population doubling time of 30 hours and cell cycle analysis showed that approximately 10% of them were in S phase. MSCs grew at significantly different rates when incubated in the presence of various recombinant human cytokines, of which interferon gamma, tumor necrosis factor alpha, stem cell factor and insulin-like growth factor promoted the proliferation of MSCs dramatically, while others tested had no effects on cell growth. CONCLUSIONS: MSCs are a homogenous population of cells that have unique growth, phenotypical and cytochemical characteristics. Furthermore, the diverse responses of MSCs to different cytokines provide a clue for the selection of optimal expansion and maintenance of MSCs.

Activated-Leukocyte Cell Adhesion Molecule↗
PubMed2001

Percutaneous balloon aortic valvuloplasty in the treatment of congenital valvular aortic stenosis in children.

OBJECTIVE: To assess the effect of the balloon valvuloplasty for for congenital valvular aortic stenosis (AS) in children. METHODS: A total of 27 (mean age 6.09 years) children with AS accepted the treatment of percutaneous balloon aortic valvuloplasty (PBAV). The ratios of balloon/valve were 0.95 +/- 0.08 for 19 cases of typical AS and 1.00 +/- 0.11 for 8 cases of hypoplastic AS. The patients were evaluated by the gradients across aortic valves in pre- and post-PBAV and by echocardiogram during the follow-up period. RESULTS: Fifteen of 19 (78.9%) cases of typical AS had a better outcome and the gradient of the remaining 4 cases (26.7%) had increased after follow-up (delta P > 50 mm Hg). Four of 8 (50.0%) cases of hypoplastic AS had satisfactory responses and the gradient of the remaining 3 cases (75.0%) rose. There was no moderate to severe aortic insufficiency (AI). CONCLUSION: The balloon aortic valvuloplasty provides safe and significant hemodynamic and clinical improvement in pediatric patients. The outcome of PBAV for typical AS is better than for hypoplastic AS.

Adolescent↗
PubMed2001

Percutaneous balloon angioplasty of coarctation of the aorta in children: 12-year follow-up results.

OBJECTIVE: To evaluate the efficiency of percutaneous balloon angioplasty of coarctation of the aorta in children and discuss its risk factors that can lead to poor long-term results. METHODS: From September 1987 to August 1999, 24 patients underwent 27 balloon angioplasty procedures for native or recurrent coarctation of the aorta at our institution. There were 19 patients with discrete (membranous) coarctation, 4 patients with long-segment and aortic arch hypoplasia, and 1 patient with postoperative recurrence. The balloon diameter was chosen not to exceed the diameter of the aorta proximal to the stenotic site (11.06 +/- 2.80 mm vs 11.78 +/- 3.18 mm), with the chosen diameter two to four times that of the stenotic segment (2.57 +/- 0.68 times). The patients have been followed up for half to twelve years (mean 6.2 +/- 2.8 years). Satisfactory result was defined as a reduction in the pressure gradient across the site of coarctation to < or = 20 mm Hg. RESULTS: The systolic pressure gradient across the coarctation site decreased from 48.17 +/- 14.68 mm Hg to 14.96 +/- 13.12 mm Hg (P < 0.01) and the diameter of the coarctation site increased from 4.66 +/- 2.43 mm to 8.80 +/- 3.32 mm (P < 0.01). Immediate satisfactory results were obtained in 19 patients (79%). Of the 5 patients with unsatisfactory results, 4 had aortic arch hypoplasia and 1 had membranous coarctation. Of the 19 patients with satisfactory results, 18 patients had membranous coarctation and 1 patient had recurrent postoperative coarctation. No aneurysm and other complications had occurred in any patients at the follow-ups. CONCLUSION: Percutaneous balloon angioplasty is an effective treatment alternative to surgery in most patients with recurrent postoperative or native membranous coarctation of the aorta. It should not be recommended for the coarctation of aortic arch hypoplasia.

Adolescent↗
PubMed2001

Molecular cloning and characterization of NAG-7: a novel gene downregulated in human nasopharyngeal carcinoma.

OBJECTIVE: To identify novel tumor suppressor genes at chromosome 3p24-26 in human nasopharyngeal carcinoma (NPC). METHODS: Twenty epithelial-derived expressed sequence tags (EST) were selected from chromosome 3p24-26. RT-PCR and Northern blot were used to detect the expression of the ESTs in NPC cell line, HNE-1, and primary cultures of normal nasopharyngeal epithelial cells. One EST, which was substantially downregulated in the HNE-1 cell line, was detected in 19 NPC biopsy samples. cDNA library screening was used to get its full sequence and the sequence of this novel gene was analyzed. RESULTS: A novel gene located at chromosome 3p25.3 was obtained and named NAG-7. It was downregulated in 26.3% (5/19) of NPC biopsy samples. Its 1677 bp full length cDNA had a potential open reading frame predicting a 94 amino acid protein with a molecular weight of 11,023.87 Dalton. Analysis of the NAG-7 gene showed that it was a transmembrane protein containing a protein kinase C phosphorylation site and a myristyl site. It has no significant homology to any reported genes in the database of GenBank. CONCLUSION: NAG-7 is a novel gene downregulated in NPC, suggesting that it may be involved in the development of NPC.

Amino Acid Sequence↗
PubMed2001

Implantation of dual chamber pacemaker defibrillator and placement of endocardial leads via the axillary vein.

OBJECTIVES: To assess the preliminary clinical results of implantation of dual chamber pacemaker defibrillator and to evaluate the safety and effectiveness of placement of endocardial leads in the axillary vein. METHODS: Seven patients with ventricular tachycardia and/or ventricular fibrillation (VT/VF), associated with bradyanhythmia received implantation of a dual chamber pacemaker defibrillator, including 5 patients with coronary artery disease and 2 patients with dilated cardiomyopathy. The atrial and ventricular leads were introduced via the axillary vein under venographic guidance. RESULTS: Dual chamber pacemaker defibrillators were successfully implanted in the left chest subcutaneous pocket in 5 patients and the left pectoral muscular pocket in 2 patients. All the VT/VF occurring either inducibly during the procedure or spontaneuously during follow-up were detected promptly and treated successfully. Both the pacing and sensing functions were satisfactory. The endocardial leads required were successfully introduced via the axillary vein without major complications. CONCLUSIONS: Dual chamber pacemaker defibrillators can provide reliable therapy for VT/VF and the dual chamber pacing function. Placement of endocardial leads via the axillary vein under venographic guidance is safe and effective.

Aged↗
PubMed2001

[Clinical analysis of idiopathic thrombocytopenic purpura with pregnancy].

OBJECTIVE: To study the optimal management of pregnant women with idiopathic thrombocytopenic purpura (ITP). METHODS: The outcomes of 37 pregnancies with ITP about 10 years from (1990 to 1999) were analysed. RESULTS: Among the 37 cases, vaginal delivery and cesarean section were done in 16 and 21 cases respectively. Neonatal thrombocytopenia was diagnosed in 3 newborns. None of them had intracranial hemorrhage. The incidences of postpartum hemorrhage and infection were 8.1% and 2.7%, respectively. No maternal mortality was noted. CONCLUSIONS: In view of very low morbidity in babies of ITP mothers, we suggest that they be delivered vaginally if there is no obstetrical complications. Selected cesarean delivery should be performed in severely thrombocytopenic cases when there are sufficient fresh blood and platelet. The invasive interventions should not be used to avoid newborn thrombocytopenia.

Adult↗
PubMed2001

Gene polymorphism in IL-1 receptor antagonist affects its production by monocytes in IgA nephropathy and Henoch-Schonlein nephritis.

OBJECTIVE: To define the functional significance of IL-1 receptor antagonist (IL-1ra) gene polymorphism and to investigate, the production of IL-1ra by monocytes from individuals with different genotypes of IL-1. METHODS: The genotype of IL-1ra was detected by polymerase chain reaction (PCR). Peripheral monocytes obtained from patients with immunoglobin A nephropathy (IgAN), Henoch-Schonlein purpura nephritis (HSPN) and normal subjects were matched in sex and age between the IL1RN-2 allele carriers and non-carriers. The secretion of IL-1ra, IL-1 alpha and IL-1 beta in the supernatant of GM-CSF (10 ng/ml) treated and untreated monocytes were measured by ELISA. RESULTS: The secretion of IL-1ra by monocytes stimulated with GM-CSF was significantly higher in the IL1RN-2 allele non-carriers than those of carriers both in IgAN (21.55 +/- 3.08 vs 13.85 +/- 2.24 ng/ml, P < 0.001) and HSPN (23.72 +/- 6.68 vs 12.67 +/- 2.24 ng/ml, P < 0.01) as well as in normal controls (20.29 +/- 1.45 vs 10.51 +/- 2.3 ng/ml, P < 0.001). All showed no significant differences in monocyte secretion of IL-1 alpha and IL-1 beta by GM-CSF stimulation between the IL1RN-2 allele carriers and non-carriers. CONCLUSIONS: These results indicate that a functional correlation of the IL1RN-2 allele and IL-1ra production is present in patients with IgAN and HSPN. This gene polymorphism control of IL-1ra production may contribute to the variety of clinical responses to inflammatory stimulation in individuals with different genotype of IL-1ra.

DNA↗
PubMed2001

[The impact of early diagnosis and thrombolytic-anticoagulant therapies on outcome of pulmonary embolism].

OBJECTIVE: To investigate the effect of early diagnosis and thrombolytic followed by anticoagulant therapy in pulmonary embolism (PE). METHODS: 46 patients diagnosed as PE were retrospectively analyzed. All the patients were treated with thrombolytic followed by anticoagulant therapy. Therapeutic effect was compared between two groups of patients with symptoms more or less than two weeks before establishment of diagnosis. RESULT: 36 patients were documented as PE by lung scan, 13 of 46 patients (28.3%) were misdiagnosed as other heart or lung diseases. All the patients had accompanying diseases, including leg deep vein thrombosis (DVT) (33/46, 71.7%) heart or lung diseases other than PE(23/46, 50%), and history of surgery (6/46, 3%). 93.1% of the patients with clinical history less than 2 weeks showed improvement, whereas only 52.9% of those with clinical history exceeding 2 weeks improved. There was significant difference between them. CONCLUSION: In order to diagnose PE early, we should pay more attention to the risk factors of PE, especially DVT. The success of thrombolysis appears to depend on the interval between the onset of symptoms and start of thrombolytic therapy. Patients with clinical symptoms less than 2 weeks show better improvement.

Adult↗
PubMed2001

[Pulmonary hyalinizing granuloma: a case report and a review of the literature].

OBJECTIVE: To highlight the characteristics of pulmonary hyalinizing granuloma (PHG). METHOD: One patient with PHG confirmed by pathological assessment was presented and relevant literatures were reviewed. RESULTS: PHG is a rare disease characterized by multiple bilateral pulmonary nodules. Symptoms include cough, dyspnea, chest pain, hemoptysis, fever and fatigue. Histologically, the nodules consist of haphazard or whorled arrays of lamellar, keloid - like collagen. Evidence suggests that the nodules are the result of a chronic exaggerated immune response. CONCLUSIONS: PHG should be considered in patients showing multiple bilateral pulmonary nodules. The clinical course of PHG in most patients is benign. At present, there is no effective therapy.

Fatal Outcome↗
PubMed2001

Pressure changes in spinal canal and evaluation of spinal cord injuries in spinal section subjected to impact.

OBJECTIVE: To observe pressure changes in the spinal canal of the vertebrarium subjected to impact. From the point of view of impact, pressure changes and spinal cord injuries, the relationship between the type of spinal fracture and the severity of spinal cord injuries were analyzed and some experimental data were provided for early evaluation of severity of spinal cord injuries. METHODS: An experimental model of spinal burst fracture was made with Type BIM-I bio-impact machine and techniques of high velocity vertical loading in static pattern and stress shielding were adopted. Vertebral sections T10-L4 taken from fresh cadavers were impacted and pressure changes in the spinal canal were observed. The types and severity of spinal fracture were studied with gross and radiography examination. RESULTS: Great positive pressure wave (wave A) in the spinal canal of the 4 vertebral specimens with burst fracture was recorded. The peak value of pressure was correlated with the severity of posterior column injuries. Generally, the peak value of pressure was low in the samples with posterior column injuries, but high in the samples without injuries. The predominant features of fractures were burst fractures of vertebral body and severe destruction of the skeletal and fiber structure of the spinal canal. Positive and negative pressure waves (wave B) were recorded in 2 vertebral samples in which no significant abnormal changes were found by radiography examination, however, a little liquid effusion in the vertebral body was found by gross examination. CONCLUSIONS: The type of pressure wave in the spinal canal is related to the deformation or the destruction of the spinal canal structure. The peak value of the pressure is non-linearly related to the obstruction in the spinal canal, but related to posterior column injuries.

Biomechanical Phenomena↗
PubMed2001

[Evaluation of p53, p21waf1, and PCNA in the diagnosis on lung cancer].

OBJECTIVE: To evaluate the diagnostic value of p53, p21waf1 and PCNA on diagnosis of lung cancer. METHODS: One hundred and fourteen lung cancer patients and 89 cases with benign pulmonary diseases were studied on the expression of p53, p21waf1 and PCNA by immunohistochemical staining. The differences of p53, p21waf1 and PCNA expression status between these two groups were compared and the diagnostic value of these three markers was evaluated. RESULTS: (1) The positive rates of p53, p21waf1 and PCNA expression in lung cancer were 47.37%, 75.44% and 80.70%, all significantly higher than that in benign pulmonary diseases (P < 0.001), with odds ratio 39.15, 5.75, 6.76 respectively. (2) The positive likelihood ratio of p53 was 21.08, higher than that of p21waf1 and PCNA. Specificity and Youden index were also higher than those of p21waf1 and PCNA, but the sensitivity of p53 was low. (3) The sensitivity and specificity of p53 and PCNA parallel test were 89.47% and 60.67% respectively. CONCLUSIONS: (1) The expression of p53, p21waf1 and PCNA in lung cancer cases were all upregulated. These three markers all seemed to have strong links with lung cancer. (2) p53 was shown a good marker for lung cancer diagnosis. (3) The diagnostic value of p53 and PCNA parallel test was rather high.

Biomarkers, Tumor↗
PubMed2001

[Prevalence survey on pterygium in two counties of Hainan Province].

OBJECTIVE: To explore the relationship between pterygium and environmental condition, such as area and weather, and human factors, such as sex and race, through the prevalence survey of pterygium in Hainan Province. METHODS: As a sample, all villagers in 14 villages were chosen by random sampling from all the rural villages of Dongfang and Changjiang Counties, the pterygium was examined and their pterygia were recorded and graded according to the shape and the location of the head of pterygium. RESULTS: In 7 990 villagers examined, there were 628 cases with pterygium, prevalence being 7.86% and including 439 cases (8.28%) in 5 303 Han people and 189 cases (7.03%) in 2 687 Li people. The difference of the prevalence between Han and Li nationality was significant (chi(2) = 3.897, P = 0.048). There were 266 male cases (6.43%) and 362 female cases (9.40%). The prevalence in male was less than that in female (chi(2) = 19.852, P = 0.001). The distribution of the pterygium in eyes was symmetrical. CONCLUSION: The prevalence of pterygium in Hainan is higher than that in other provinces of China. It may be related to the geographic location and weather condition. In Hainan Province, the prevalence of pterygium in Han nationality is higher than that in Li nationality and in female higher than that in male. The increase of the prevalence of pterygium may be related to the increase of age.

Adolescent↗
PubMed2001

[Bioactivity and test grafting of acellular dermal matrix containing fibroblasts].

OBJECTIVE: To investigate the bioactivity of acellular dermal matrix with fibroblasts and its role as dermal skeleton. METHODS: Human fibroblasts (HFs) were planted onto the surface of acellular dermal matrix (ADM) to form living dermal substitute. The IL -- 6, IL -- 8 and TGF contents in the supernatant of the culture of HF -- ADM were determined with ELISA method, and the secretion of hyaluronic acid and laminin from extracellular matrix was measured with RIA method. The speed of vascularization and the wound contracture rate were observed after the dermal substitute was grafted on the full skin loss wound of Balb/c-nu mice (nude mice). RESULTS: HFs grew very well after being planted onto ADM so as to form a single layer of cellular membrane. Many kinds of cytokines and extra cellular matrix components were secreted. Compared with simple acellular dermal grafting, the vascularization was accelerated, and the wound contracture rate decreased, after the living dermal substitute being grafted on the wound. CONCLUSION: The ADM seeded with HFs exhibited excellent bioactivity and might be an optimal dermal substitute.

Animals↗
PubMed2001

[Expression of leukemia inhibitory factor in the decidua of normal early pregnancy, threatened abortion and inevitable abortion].

OBJECTIVE: To investigate the expression of leukemia inhibitory factor (LIF) in the decidua of normal early pregnancy, threatened abortion and inevitable abortion. METHOD: We examined LIF gene expression in the above-mentioned decidua by a quantitative reverse transcription-polymerase chain reaction (RT-PCR) method, and also examined the serum pregesterone, human chorionic gonadotrapin (hCG) by radioimmunoassay in all cases. RESULTS: (1) Serum levels of pregesterone and hCG are: (91.5 +/- 27.2) nmol/L, (69.9 +/- 14.9) kU/L in normal early pregnancy; (88.4 +/- 24.7) nmol/L, (57.6 +/- 11.2) kU/L in threatened abortion respectively. There was no difference in the levels of pregesterone and hCG between the two groups (P > 0.05). While serum pregesterone, hCG levels in inevitable group were (33.1 +/- 19.6) nmol/L, (10.3 +/- 3.2) kU/L respectively. Compared with normal early pregnancy and threatened abortion group, the levels of serum pregesterone and hCG reduced significantly (P < 0.05). (2) The expression of LIF in three groups: There was no statistically significant difference in the levels of LIF expression between the normal early pregnancy group (2.10 +/- 0.32) and threatened abortion (1.92 +/- 0.20) groups, while the levels of LIF expression in inevitable abortion group (0.7 +/- 0.06) was lower than those in normal early pregnancy group and threatened abortion group (P < 0.05, respectively). CONCLUSION: The reduction of LIFmRNA expression in the decidua of early pregnancy may decrease the serum pregesterone and hCG levels and cause inevitable abortion.

Abortion, Spontaneous↗
PubMed2001

Effect of batroxobin on expression of neural cell adhesion molecule in temporal infarction rats and spatial learning and memory disorder.

The effect of Batroxobin expression of neural cell adhesion molecule (NCAM) in left temporal ischemic rats with spatial memory disorder was investigated by means of Morri's water maze and immunohistochemical methods. The results showed that the mean reaction time and distance of temporal ischemic rats for searching a goal were significantly longer than those of sham-operated rats and at the same time NCAM expression of left temporal ischemic region was significantly increased. However, the mean reaction time and distance of Batroxobin-treated rats were shorter and they used normal strategies more often and earlier than those of ischemic rats. The number of NCAM immune reactive cells of Batroxobin-treated rats was more than that of ischemic group. In conclusion, Batroxobin can improve spatial memory disorder of temporal ischemic rats and the regulation of the expression of NCAM is probably related to the neuroprotective mechanism.

Animals↗
PubMed2001

[GC-MS analysis of essential oils from rhizomes of Atractylodes lancea (Thunb.) DC. and A. chinensis (DC.) Koidz].

OBJECTIVE: To analyze the constituents from the rhizomes of Atractylodes lancea and A. chinensis in essential oils. METHOD: GC-MS method was used. RESULT: 32 and 29 compounds were identified respectively. CONCLUSION: The main constituents in the essential oils from the rhizome of A. chinensis are beta-eudesmol or a mixture of beta-eudesmol and atractylone, whereas from that of A. lancea are hinesol, a mixture of beta-eudesmol and atractylone, and atractylone.

Atractylodes↗