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Biomedical subjects

Y Huang

Publications and source records attributed to Y Huang.

At least 415 records · Page 23Linked to original sources
PubMed2000

Effect of selenium on human myocardial glutathione peroxidase gene expression.

OBJECTIVE: To examine the role of selenium (Se) in the expression and activity of selenium-dependent cellular glutathione peroxidase (GPX-1). METHODS: 46 patients with atrial septal defect or ventricular septal defect were separated into two groups, a control group (23 cases) and a Se supplementation group (23 cases). The Se supplementation group received 400 micrograms selenium per day for 7 days before surgery. We used biochemical techniques, atomic absorption, RT-PCR and cDNA sequence testing methods to evaluate and compare the changes during ischemia/reperfussion (I/R) in myocardial melondialdehyde (MDA) level, GPX activity and gene expression level, GPX cDNA nucleotide sequence, selenium and calcium and magnesium concentration. RESULTS: Before ischemia, taking selenium for 7 days did not change the selenium concentration in either plasma or blood cells in either group. The GPX mean activity level in the selenium group was slightly lower than that in the control group, and the MDA level was equal in both. After 30 minutes of reperfusion, the Se level in plasma and blood cells remained constant, while the myocardial Se concentration and GPX gene expression in the Se group increased significantly. The MDA level in the Se group reduced 4.2%, compared to an 8.2% rise in the control group. The mean level of GPX activity in the Se group was slightly lower than that in the control group. Both pre- and post-myocardial reperfusion, the Se group had a higher rate of myocardial GPX gene expression, and the nucleotide sequence was normal. These results indicate that supplementing Se is not likely to enhance myocardial GPX activity, but it could increase the GPX gene expression level, and thereby enhance the Se patients' myocardial antioxidant level during I/R, allowing free radicals to be scavenged as soon as they are generated. CONCLUSION: Se supplementation could increase myocardial selenium content and improve GPX gene expression during I/R, and in this way defend against free radical peroxide damage to the myocardium.

Adolescent↗
PubMed2000

[Gluteal sciatic nerve injury and its treatment].

OBJECTIVE: To analysis the clinical characters of gluteal sciatic nerve injuries and investigate the treatment options. METHODS: From October 1962 to June 1997, 190 patients with gluteal sciatic nerve injuries were adopted in this retrospective study. In these cases, the sciatic nerve injuries were caused by injection in 164 patients(86.32%), stab injury in 14 patients, pelvic fracture and hip dislocation in 11 patients, and contusion injury in 1 patient. Among them, 15 cases were treated by conservative method and the other 175 cases were operated. According to the observation during the operations, the injuries were occurred at the region of gluteal muscle in 146 cases, at the region of piriform muscle in 26 cases, and at the region of pelvic cavity in 3 cases. Then neurolysis was performed in 160 cases, epineurial neurorrhaphy in 12 cases and nerve grafting in 2 cases, and nerve exploration but no repair in 1 case. Late stage functional reconstruction of the foot and ankle was carried out in 23 cases. RESULTS: One hundred and fifty-one patients were followed up 8.5 years in average. The occurrence of excellent and good nerve recovery was 56.95% and the occurrence of excellent and good functional reconstruction of late stage was 78.26%. CONCLUSION: The gluteal sciatic nerve injury has since been challenging because of the tremendous difficulty in treatment and the poor outcome. The injury situation at the different region was closely related to the regional anatomy. According to this study, it is advised that the surgical treatment should be carried out actively. Neurolysis should be performed as soon as possible in the cases of injection injury. Epineurial neurorrhaphy should be performed in the cases of nerve rupture. In case of the gluteal sciatic nerve injury which caused by pelvic fracture or hip dislocation, the reduction and decompression is suggested in the early stage, and exploration and nerve repair is indicated in the late stage. The functional reconstruction of foot and ankle should be carried out in the late stage for the improvement of the limb function.

Adolescent↗
PubMed2000

[The relationship between sensitivity to arsenic trioxide and antioxidative capacity of malignant hematopoietic cells].

OBJECTIVE: To detect the relationship between sensitivity of malignant hematopoietic cells to arsenic trioxide (As2O3) and cellular capacity against oxidation. METHODS: Nine cell lines derived from hematopoietic malignancies were treated with As2O3 in vitro. Apoptosis was assessed by cellular viability, cytomorphology and flow cytometry. The As2O3-treated cells were examined for glutathione (GSH) level and activity of catalase (CAT), superoxide dismutase (SOD), glutathione S-transferase (GST) and glutathione peroxidase (GPX). RESULTS: Of the 9 cell lines examined, the acute promyelocytic leukemia cell line NB4 and its retinoic acid-resistant subclones R2 and MR2, the Burkitt lymphoma cell line Namalwa and multiple myeloma cell line RPMI 8226 were sensitive to As2O3-induced apoptosis while the acute T cell leukemia cell line (Jurkat) and 3 cell lines (HL-60, U937, K562) of myelogenous leukemia origin were not. In comparison with the sensitive cell lines, higher activity of CAT was found in HL-60 and U937, higher level of GSH in Jurkat, and both in K562. However, activity of GPX, GST and SOD did not significantly correlate with their resistance to As2O3-induced apoptosis. CONCLUSION: Intracellular GSH level and/or catalase activity are important factors to determine sensitivity of malignant hematopoietic cells to As2O3-induced apoptosis.

Apoptosis↗
PubMed2000

[Clinical observation on treatment of thyrotoxic exophthalmos with jiayanxiao plus tapazole].

OBJECTIVE: To study the therapeutic effect of Jiayanxiao (JYX) on thyrotoxic exophthalmos. METHODS: Forty-three patients were divided randomly into two groups, the 31 Patients in the treated group were treated with JYX plus tapazole, and the 12 patients in the control group were treated with prednisone plus tapazole. The therapeutic course of both groups was 3 months. The symptoms, eye signs, thyroxin level, and other routine laboratory parameters as well as the adverse effect of the therapy were observed and compared between two groups. RESULTS: The total effective rate in the treated group was 80.6%, which was obviously higher than that in the control group (50.0%, P < 0.05). Effect of the treated group in lowering degree of exophthalmos was superior to that of the control group. Effects in elevating vision, decreasing palpebral fissure altitude and lowering serum T3, T4 contents in the two groups were similar (P > 0.05). Moreover, the treated group showed better efficacy in improving clinical symptoms with less adverse effect. CONCLUSION: The therapeutic effect of JYX in treating thyrotoxic exophthalmos is ensured.

Adolescent↗
PubMed2000

[Telomerase activity of peripheral blood mononuclear cells in patients with acquired immune dysfunction].

OBJECTIVE: To investigate telomerase activity of peripheral blood mononuclear cells (PBMC) in patients with acquired immune dysfunction. METHODS: Telomerase activity of peripheral PBMC isolated from 4 groups including healthy subjects (17), chronic hepatitis B patients (14), diabetic patients (8) and chronic renal failure patients (8) was assayed with PCR-ELISA. RESULTS: (1) Telomerase activity was detectable at low levels in resting PBMC of all the 4 groups. It increased obviously after in vitro phytohemagglutinin (PHA) stimulation; (2) Telomerase activity of the resting PBMC in chronic hepatitis B patients was significantly lower than that in normal subjects, and was upregulated to the same level in the both groups after PHA stimulation; (3) No effect of recombinant human interleukin-12 on telomerase activity of activated T lymphocytes was found. CONCLUSIONS: PBMC may express telomerase activity and the decreased telomerase activity of PBMC in patients with chronic hepatitis B may partially be responsible for immune dysfunction in these patients.

Adolescent↗
PubMed2000

Surgical treatment of portal hypertension: 45 year experience.

OBJECTIVE: To review the experience in surgery for 912 patients with portal hypertension. METHODS: The 912 patients were divided into three groups: before 1978 (group A), 1978 - 1989 (group B), and 1990 - 1998 (group C). The results were reviewed of portosystemic shunt (PSS), disconnection and disconnection plus PSS for emergency and elective operation at different periods. RESULTS: In the 912 patients of groups A, B, C, the number of PSS, disconnection, and PSS plus disconnection was 345, 13, 0; 84, 209, 0; 63, 204, 63, respectively. The number of emergency operation was 45, 13 and 4 in each group. The operative mortality of shunt in the groups A, B, C was 7.82%, 7.14% and 0, respectively; that of disconnection in the groups A, B, C 15.38%, 6.28% and 4.94%; and that of PSS plus disconnection in group C 3.51%. Encephalopathy occurred in 14.37% of the PSS group, in 5.68% of the disconnection group, and in 5.77% of the disconnection plus PSS group. Rebleeding occurred in 10.78% of the PSS group, in 18.95% of the disconnection group, and in 7.69% of the disconnection plus PSS group. CONCLUSIONS: Operative indications for the cirrhotic patients with portal hypertension depend on their liver function. For those patients with poor liver function, surgery is considered when their liver function is improved. We suggest prophylactic operation is valuable. Other indices from barium meal, color ultrasound, and endoscopy are also considered. The number of emergency operation has been decreasing. Since the 1980s, disconnection operation has been adopted increasingly. In our hospital, the number of patients receiving disconnection has been increasing from the early 1980s and the operation has almost replaced shunt operation in the 1990s. Disconnection combined with splenorenal shunt can lower the portal pressure and maintain the portal flow. Disconnection combined with splenorenal shunt seems to be a better procedure of choice.

Adolescent↗
PubMed2000

[Complications of massive allografts after segmental resection of malignant bone tumors].

OBJECTIVE: To analyze the postoperative complications of bone and joint allografting for the reconstruction of massive bone defect after the resection of malignant bone tumors and its management. METHODS: Bone-joint allografting for the reconstruction of massive bone defect after the resection of malignant bone tumors with different internal fixations was performed in 106 patients with complete follow-up data. Bone healing time, complication rate, and final results in different allografts were compared. Operation indications, complications and internal fixation were also analyzed. The final results were determined according to the Mankin's standard. RESULTS: Allografts Alcohol immersed were more susceptible to infection, non-union, etc. Allografts and combined prosthesis were superior to semi-articular transplantation. Complications included deep infection (10%), skin necrosis (12.2%), local recurrence (14.4%), and delayed union or non-union (15.6%). Dynamic interlocked intramedullary nailing was superior to conventional intramedullar nailing and compression plates. CONCLUSIONS: Allografting is acceptable for the reconstruction of massive bone defect after tumor resection. Its results are encouraging after proper management of complications caused by surgical technique, internal fixation and soft tissue repair.

Adolescent↗
PubMed2000

[A case-control study on the relationship between abnormal homocysteine metabolism and essential hypertension].

OBJECTIVE: To examine the relationship between abnormal homocysteine metabolism and essential hypertension in a Chinese population, a community-based case-control study was conducted. METHODS: 127 essential hypertensive patients aged 35 to 75 were randomly selected from a community. Another 170 control subjects with blood pressure < 140/90 mmHg were selected from the same community. Serum homocysteine was determined using HPLC. Folate and vitamin B(12) were measured by radioimmunoassay. MTHFR genotypes were identified by PCR and restriction fragment length polymorphism analysis with Hinf I digestion. RESULTS: After adjusting for age and sex, the mean homocysteine level was 10.56 micromol/L for hypertensive patients and 10.34 micromol/L for controls (F = 0.234, P = 0.63). No association between either SBP or DBP and Hcy concentration was found in subjects without anti-hypertensive medications. The prevalence of homozygousity for thermolabile MTHFR variant for this population was 13.1%, and the mutant allele frequency was 38.7%. There was no significant difference on genotype distributions and the mutant allele frequency for the two studied groups. However, the concentrations of folate and B(12) for the hypertensive subjects were generally higher than the controls. CONCLUSIONS: The present study did not discover that the elevation of Hcy levels or MTHFR mutation were independent risk factors for essential hypertension. The higher folate and B(12) in the hypertensive subjects might contribute to a lower risk.

Adult↗
PubMed2000

[Effects of thrombin peptides on wound healing and proliferation and migration of normal human epidermal keratinocyte (NHEK)].

OBJECTIVE: To define the effects of thrombin peptides on wound healing and NHEK proliferation and migration. METHODS: A wound model was made with four 1.5 cm circular full thickness dermal excisions on the back of each Sprague-Dawley rat. 0.1 microgram (40 microliter) TP508 was applied to each circular excisional wound in 9 rats, the other 9 received saline only. Wound area was calculated with JAVA Jandel and IMAGE PRO software. NHEK945 proliferation was assessed by MTT assay and direct cell count with a Coulter Counter. Cell migration was determined by 48-well Boyden Chamber. Cells migrated onto the lower surface of the filter were assessed by a Chemi Imager 4000 Image Analyzer and expressed as spot density. RESULTS: Wound area in rats treated with TP508 was 73.7% and 45.4% of saline control on day 7 and 14, respectively. NHEK945 proliferation was accelerated after adding thrombin and TP508. The spot density of migrated cells was 76.7 plus minus 13.8 in medium alone. After adding 1 microgram/ml of thrombin and 10 microgram/ml of TP508, the spot density was 104.4 plus minus 12.2 and 109.4 plus minus 14.6, respectively. CONCLUSION: Results of this study suggest that both thrombin and TP508 have significant actions on wound healing and NHEK proliferation and migration, which is important in wound repair.

Animals↗
PubMed2000

[The effects of rapid fluid replacement on the hemodynamics of scalded shock dogs with delayed resuscitation].

OBJECTIVE: To investigate the effects of rapid fluid replacement on the hemodynamics of scalded shock dogs with delayed resuscitation and to explore the protocol for the correction of postburn shock in case of delayed resuscitation. METHODS: Mongrel dogs inflicted with 40% TBSA III degree scalding were employed in the study. Twenty -- four dogs were randomly divided into 3 groups, i.e. thermal injury control group (C), delayed even fluid infusion group (E) and delayed rapid fluid infusion group (R). The femoral arterial pressure (FAP), pulmonary arterial pressure (PAP), pulmonary vascular resistance (PVP) and systemic vascular resistance (SVR) were monitored before and 2, 6, 8, 12, 24, 36 and 48 hours after injury. RESULTS: (1)All The dogs in C group died within 36 postburn hours (PBHs), while those in E and R groups survived more than 48 PBHs. (2) FAP and CO in all the dogs decreased obviously postburn while SVR increased evidently. After fluid infusion, FAP and CO bounced back while SVR decreased, especially in R group. (3) PAP, PAWP, CVP and PVR recovered rapidly but within normal range in R group. CONCLUSION: Rapid fluid resuscitation was beneficial and feasible for the correction of burn shock due to delayed resuscitation.

Animals↗
PubMed2000

[The postburn "shock heart"].

OBJECTIVE: To investigate the pathogenesis of postburn "shock heart". METHODS: A combined serial studies in both animal experiments and prospective clinical investigation were carried out with the determination of indices reflecting myocardial injury, such as cardiac function, myocardial injury parameters, cytoplasmic and cytoskeletal structure injury, myocardial biomechanics and pathomorphological changes. The pathogenesis was also explored by the evaluation of myocardial nutritional blood flow (NBF), cardiac myocytic oxygen consumption, energy metabolism and cytokines released from cardiac myocytes. RESULTS: Cardiac function, myocardial biomechanics, NBF, the oxygen consumption, energy metabolism and the viscoelastic properties of cardiac myocytes decreased significantly postburn, and myocyte cytoplasm and cytoskeleton were damaged after burn. Furthermore, focal dissolution and fragmentation of myocardiac fibers were observed. In the meantime the plasma levels of CM -- LC, TnT and myocardial tissue cytokines increased markedly. CONCLUSION: These results suggest that organic damage of cardiac myocytes occurred during postburn shock stage. The principle pathogenesis might be related to ischemic -- reperfusion injury, inability of oxygen utility and energy metabolism in cardiac myocytes, as well as myocardial edema and uncontrolled inflammatory response.

Animals↗
PubMed2000

[The effects of escharectomy en masse during shock stage on the secretion of cytokines from macrophage in scalded rats].

OBJECTIVE: To explore the effects of the plasma from rats undergoing escharectomy en masse during shock stage on the secretion of TNFalpha, IL-6 and IL-8 by macrophage. METHODS: Rats inflicted by 30% III degree scald were employed as the model. Sixty-three rats were randomly divided into escharectomy (E) and scald (C) groups. The plasma contents of TNFalpha, IL-6 and IL-8 in rats in two groups were determined. The plasma from rats in two groups was respectively co-cultured with rat peritoneal macrophages for 6 hours and the TNFalpha, IL-6 and IL-8 in the supernatants of the culture were assayed. RESULTS: Plasma contents of TNFalpha, IL-6 and IL-8 were evidently increased in both E and C groups. But the contents of these cytokines in E group decrease and were much lower than those in C group at 12 postburn hour. The sera from two groups of rats could all stimulate the secretion of TNFalpha, IL-6 and IL -- 8 from peritoneal macrophages, but the serum from C group possessed stronger stimulating ability than that from E group. CONCLUSION: Escharectomy en masse during shock stage could weaken the ability of burn sera to induce the secretion of TNFalpha, IL-6 and IL-8 by macrophages. It was therefore beneficial to the prevention of postburn development of systemic inflammatory response syndrome.

Animals↗
PubMed2000

[Exercise ECG test as a method for non-invasive detection of myocardial ischemia].

OBJECTIVE: To improve the exercise ECG analysis for non-invasively detection of myocardial ischemia. METHOD: The newly developed measuring system of exercise ECG defines ST segment area and STA/HR slope as the new characteristic parameters, thus can sensitively detect myocardial ischemia. Some methods were proposed to reduce noise and artifacts for effective sampling of exercise ECG. RESULT: 14 exercise ECG records were sampled and analyzed in clinical exercise test. It was found that the new parameters are very effective and sensitive to myocardial ischemia. The results show that the method is reliable and stable. CONCLUSION: The method improves one of the evaluating indexes of exercise ECG analysis. It is quite promising for clinical application in future.

Aerospace Medicine↗
PubMed2000

[Material selection and structural design of simulated space module for field].

OBJECTIVE: To select the suitable material for the structure of simulated space cabin to meet the special requirements which the unitary metallic material cannot do. METHOD: The structural material was selected through comparison between the mechanical properties of fiber reinforced plastics (FRP) and a few conventional metallic materials. The content and arrangement of the fibers in the composite material were suitably designed according to load condition and structural shape of the cabin. RESULT: High strength and high stiffness, light weight, anti-fatigue and shock proof were achieved for the whole module structure. It meets the medical and hygienic standard for hazardous gases. CONCLUSION: The structural design of fiber glass reinforced plastics composite module was proved to be successful. It reduced the weight of the module body, and increased the strength and toughness of the whole module.

Compressive Strength↗
PubMed2000

[In vitro studies about the effects of implant materials on calmodulin, introcellular calcium of rat osteoblasts].

OBJECTIVE: 1. To evaluate the effects of the four implant materials, hydroxyl poly calcium sodium phosphate (HPA), hydroxyapatite (HA), bioglass ceramics (BGC) and titanium (Ti) on the calmodulin (CaM) content of osteoblasts, the concentration of intracellular free calcium and the ATPases activity of cell membrane of rat osteoblasts cultured in vitro; 2. To reveal the biological compatibility of the four implant materials and the index to estimate the biological compatibility condition. METHODS: The powders of HPA, HA, BGC and Ti were sterilized and made into extracted solutions with 199 culture medium. The isolated osteoblasts, which were taken from three-day-old sparague Dawley rats' calvaria, were incubated in 199 culture medium also. Then the osteoblasts were mixed and incubated into the four kinds of extracted solutions of the implant materials. After three days of co-incubation, the cells were taken out, and the cellular calmodulin content were measured with radiobiological analysis. The concentration of intracellular free calcium were under fluorescent analysis, and the ATPases activities of cell membrane were estimated with colorimetric analysis. RESULTS: 1. Calmodulin content of the osteoblasts co-incubated with all the implant materials decreased, and moreover, only that of the Ti group decreased more obviously than that of the Ti and HPA group (P < 0.05). 2. The concentration of intracellular free calcium of all the co-incubated osteoblasts were as normal as that of the control group. 3. Ca(2+)-ATPases activities of osteoblasts co-incubated with HPA, HA, BGC increased (P < 0.05), and Na+/K(+)-ATPases activities of the cells co-incubated with HPA, HA were strenghtened (P < 0.05). CONCLUSION: The indexes of cellular calmodulin content, concentration of intracellular free calcium and ATPases activity of cell membrane can reflect the biological compatibility of implant materials, and they may be used as indexes of estimating biological compatibility condition.

Animals↗
PubMed2000

[In vitro studies about the effects of implanted materials on osteocalcin and alkaline phosphatase of rat osteoblasts].

OBJECTIVE: To evaluate the effects of the four implant materials, hydroxyl poly calcium sodium phosphate (HPA), hydroxyapatite (HA), bioglass ceramics (BGC) and titanium (Ti) on osteocalcin secreting amount and alkaline phosphatase activity of rat osteoblasts cultured in vitro, and expose the biological compatibility conditions of the implant materials as well as the index to estimate cytocompatibility. METHODS: The powders of HPA, HA, BGC and Ti were sterilized and made into extracted solutions with 199 culture medium, and the isolated osteoblasts which were taken from three-day-old Sprague-Dawley rats' calvaria, were incubated in 199 culture medium too. Then the osteoblasts were mixed and incubated into the four kinds of extracted solutions of the implant materials. After eight days of co-incubation, the cells were taken out to measure alkaline phosphatase activity with velocity analysis, and the extracellular liquid was used to estimate osteocalcin secreting amount with radioisotope analysis. RESULTS: 1. Osteocalcin secreting amount of the osteoblasts co-incubated with HPA, HA, BGC were as normal as the control, while that of other cells co-incubated with titanium was reduced (P < 0.05). 2. Alkaline phosphatase activities of all the co-incubated osteoblasts were as normal as the control. CONCLUSION: The osteocalcin secreting amount and alkaline phosphatase activity can reflect the biological compatibility of implant materials, and they may be used as indexes to evaluate biological compatibility condition of implant materials.

Alkaline Phosphatase↗
PubMed2000

[Study on the determination of trace ions in the presence of high concentration of matrix by simplified column-switching ion chromatography].

A simplified column-switching technique for the determination of trace ions in the presence of high concentration of matrix is established. A binary eluent mechanism is developed to study the effect of matrix on the shift of the analyte retention time. According to this mechanism, eluent of high concentration is preferred to suppress the peak shift of trace analyte caused by large amount of matrix. Since the peak shift has been effectively suppressed, the procedures for determining the column-switching time windows were greatly simplified. According to the different samples, different strategies should be employed in this technique. In this work, three typical samples were analyzed by this technique and the strategies for these three samples were studied to show the principles of choosing the proper separation conditions. Results showed that by this simplified technique analysis for trace analytes in the presence of complicated matrix was accurate and precise. The successful use of this method to the determination of trace bromate in drinking water, and nitrate, ammonium and iodide in sea water indicates that the application of this versatile technique to quantify analytes of low concentration in a wide range of sample matrices is promising.

Bromates↗