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Biomedical subjects

H Yu

Publications and source records attributed to H Yu.

At least 325 records · Page 18Linked to original sources
PubMed1999

Insulin-like growth factors (IGF-I, free IGF-I and IGF-II) and insulin-like growth factor binding proteins (IGFBP-2, IGFBP-3, IGFBP-6, and ALS) in blood circulation.

Insulin-like growth factors (IGFs) and IGF binding proteins (IGFBPs) play an important role in cell growth and differentiation. Clinical and epidemiological studies have indicated that measuring IGFs and IGFBPs in blood has potential implications in assessing growth-related abnormalities and risks of certain types of cancer. To facilitate the application, we reported a large collection of reference ranges of IGFs and IGFBPs in normal population and evaluations of these molecules in serum and plasma as well as the impact of freeze-thaw cycles on the measurement. IGF-I, IGFBP-3 andALS showed a similar pattern of change associated with age. Levels of these molecules were low at birth and increased with age through puberty. After puberty the levels declined slowly with age. Overall, IGF-I, IGFBP-3 and ALS were slightly higher in females than in males. Free IGF-I accounted for about 1% of the total IGF-I and its variation with age was similar to total IGF-I. IGF-II levels were also increased with age from birth to puberty, but became stable after puberty. There was little difference in IGF-II levels between genders. IGFBP-2 levels declined with age from birth to puberty. Levels of IGFBP-6 in contrast were increased with age. These IGF binding proteins were higher in males than in females. IGFs, IGFBP-3 and ALS were 5-10% higher in serum than in plasma. IGFBP-2 and IGFBP-6 differed substantially between serum and plasma. Freeze-thaw treatment up to five cycles had little impact on plasma levels of IGFs and IGFBP-3. Our observations suggest that levels of IGFs and their binding proteins are varied with age, gender, and types of specimen and that these variations need to be taken into consideration when IGFs and their binding proteins are utilized in clinic and research.

Adult↗
PubMed1999

[Rapid detection of trisomy 21 by quantitative polymerase chain reaction].

OBJECTIVE: Studying gene diagnosis of trisomy 21 by means of quantitative polymerase chain reaction(PCR). METHODS: Polymorphic short tandem repeat(STR) at D21S11 served as the gene marker, and a pair of primers was synthesized. The samples from 11 normal subjects and 28 cases of trisomy 21 were analyzed by quantitative PCR. RESULTS: 10 normal subjects showed two bands with a ratio of 1:1, and a subject showed one band. Of 28 cases of trisomy 21, 24 cases showed two bands with a ratio of 2:1, 3 cases showed three bands with a ratio of 1:1:1, and 1 case showed one band. CONCLUSION: Polymorphic STR at D21S11 is a valuable gene marker for diagnosis of trisomy 21. Trisomy 21 can be diagnosed rapidly and accurately within 24 hours by quantitative PCR.

Down Syndrome↗
PubMed1999

A feasibility study of gene gun mediated immunotherapy for renal cell carcinoma.

PURPOSE: Gene modified autologous tumor cell vaccines have demonstrated a protective and therapeutic effect in murine tumor model systems. The majority of trials to date have used viral methods of gene transfer for vaccine construction. An alternative approach to transfer genes into tumor cells is to use the gene gun, which is a physical method of gene transfection that produces high levels of gene expression without viral agents. We establish the feasibility of generating cytokine secreting autologous renal tumor cell vaccines for use in gene therapy for metastatic renal cell carcinoma. MATERIALS AND METHODS: We obtained 1 cm3 tumor tissue from 12 patients undergoing resection of primary or metastatic renal cell carcinoma. The tumor was disaggregated and placed in culture. The phenotype of the primary renal cell lines was established by microscopy and immunohistochemistry. The 1x10(7) lethally irradiated tumor cells were transfected with plasmid deoxyribonucleic acid containing the human (h) granulocyte-macrophage colony-stimulating factor (GM-CSF) gene under control of a cytomegalovirus promoter using the gene gun. The hGM-CSF production was assayed by enzyme-linked immunosorbent assay in the cell culture media 24 hours after transfection. RESULTS: Of 12 tumor samples 8 grew rapidly to produce a mean of 1.8x10(8) cells after 4 to 5 passages in culture, which was sufficient to produce between 24 and 32 vaccines. Immunocytochemistry confirmed that all cultures were almost exclusively renal tumor cells. Gene gun mediated transfection of lethally irradiated tumor cells resulted in high levels of hGM-CSF production (mean 330 ng./10(6) cells per 24 hours). CONCLUSIONS: We have demonstrated the feasibility of producing cytokine secreting tumor cell vaccines from primary and metastatic human renal tumors, and plan to use this approach in phase I clinical trials of gene therapy for metastatic renal cell carcinoma.

Biolistics↗
PubMed1999

Inflammatory markers in men with angiographically documented coronary heart disease.

BACKGROUND: Recent evidence suggests that atherosclerosis is a chronic inflammatory process. In this study, we examined several markers of inflammation in men with coronary heart disease (CHD) and appropriate controls. METHODS: The concentrations of C-reactive protein (CRP), serum amyloid A (SAA), interleukin-6 (IL-6), and soluble intracellular adhesion molecule (sICAM-1) were examined in 100 men with angiographically documented CHD and 100 age-, gender-, and smoking-matched controls with no history of CHD. We assessed the association of these markers with severity of disease as indicated by >50% obstruction in one vessel (n = 30), two vessels (n = 39), or three vessels (n = 31). RESULTS: Significant increases were noted in serum CRP (median for cases vs controls, 3.4 vs 1.5 mg/L; P <0.0001), SAA (5.9 vs 3.7 mg/L; P <0.005), and IL-6 (2.3 vs 1.7 ng/L; P <0. 013) in patients with CHD compared with controls. These differences remained significant after correction for age, smoking, hypertension, diabetes, and lipid and homocysteine concentrations. Plasma sICAM-1 was not significantly different between the two groups (335 vs 339 microg/L). No significant correlation was seen between these markers and the severity of coronary disease. CONCLUSIONS: Concentrations of CRP, SAA, and IL-6 were increased in patients with CHD but failed to correlate with severity of coronary disease. These markers might reflect the diffuse atherosclerotic process in the vascular system rather than the degree of localized obstruction from coronary lesions.

Adult↗
PubMed1999

Representing genomic knowledge in the UMLS semantic network.

Genomics research has a significant impact on the understanding and treatment of human hereditary diseases, and biomedical literature concerning the genome project is becoming more and more important for clinicians. The Unified Medical Language System (UMLS) is designed to facilitate the retrieval and integration of information from multiple-readable biomedical information resources. This paper describes our efforts to integrate concepts important to genomics research with the UMLS semantic network. We found that the UMLS contains over 30 semantic types and most of the semantic relations that are essential for representing the underlying genomic knowledge. In addition, we observed that the organization of the network was appropriate for representing the hierarchical organization of the concepts. Because some of the concepts critical to the genomic domain were found to be missing, we propose to extend the network by adding six new semantic types and sixteen new semantic relations.

Genome, Human↗
PubMed1999

Signal Transducers and Activators of Transcription: Novel Targets for Anticancer Therapeutics.

BACKGROUND: Through specific activation of gene expression, the family of proteins known as signal transducers and activators of transcription (STATs) converts extracellular stimuli into diverse biological responses. Beyond the normal signaling functions of STATs, recent evidence indicates that aberrant activation of STATs contributes to neoplastic transformation. METHODS: Current literature pertaining to the role of STAT proteins in oncogenesis is presented. Also, the rationale for developing novel approaches to disrupt STAT signaling is discussed, and the potential of STATs as anticancer targets in treating human cancer is reviewed. RESULTS: The discovery that certain oncoproteins constitutively activate specific STATs, coupled with observations that elevated STAT activity occurs frequently in a spectrum of human tumors, establishes a direct link between STAT activation and neoplastic transformation. Significantly, abrogation of STAT signaling blocks oncogenesis in model in vitro and in vivo systems. These results make STATs attractive targets for rational design of small molecule inhibitors and gene therapy approaches to disrupt STAT signaling. CONCLUSIONS: As a result of genetic, biochemical, and crystallographic analyses, the functional domains of STAT proteins have been well characterized. Based on these data, selective inhibitors of STAT function can be designed. Because disrupting STAT signaling has proven effective in blocking neoplastic transformation, it is proposed that STAT proteins represent promising targets for development of novel molecular therapeutics to treat human cancer.

Journal Article↗
PubMed1999

Relationship between diabetes mellitus, impaired glucose tolerance and age, menopause, pregnancy: a survey of 5153 women in Shenzhen.

OBJECTIVE: To investigate the relationship between diabetes mellitus (DM) including impaired glucose tolerance (IGT) and the factors of age, menopause, and pregnancy. METHODS: A systemic epidemiological survey was conducted in 5153 women, aged 20 years and above. RESULTS: The prevalence of DM was 4.58%, and IGT 12.83%. In those subjects with DM less than 59 years old and those with IGT less than the age of 49, the prevalence was parallel to the increase of age. Ten years might lead the IGT subjects into DM. Moreover, the prevalence of DM and IGT after menopause were significantly high. It was found that the prevalence of DM and IGT in mothers who had conceived giant baby was significantly higher than that of the others. CONCLUSIONS: Therapeutic emphasis should be laid on the population of women in the age between 50 and 59, while the management of IGT women is equally important. The early intervention of IGT subjects in the age between 40 and 49 is essential in decreasing the prevalence of DM. Disorders of the endocrine system during climacteric might play an important role in the development of DM and IGT. Moreover, the mothers who have conceived giant babies are at great risk for DM, and thus, this population should be closely monitored.

Adult↗
PubMed1999

Cross-sectional survey of intralymphocytic and serum elements in hypertensive patients.

OBJECTIVE: To investigate the distribution characteristics of some common and trace elements in both serum and lymphocyte in patients with essential hypertension and to analyse their possible role in the pathogenesis of hypertension. METHODS: A cross-sectional study was carried out in 102 hypertensive patients matched with equal number of normotensive subjects by sex, age, and hypertensive family history; all of them were randomly selected from the same community. Both intralymphocytic and serum concentrations of some relevant elements including Na+, K+, Ca2+, Mg2+, Zn2+, Cu2+ and P were measured for all studied subjects, using the inductively coupled plasma spectrometry (ICPS). RESULTS: 1. Both intralymphocytic and serum concentrations of Na+ (P = 0.009, 0.004 respectively), and Ca2+ (P = 0.001, 0.049 respectively) in hypertensive group were significantly higher than those in the normotensives. 2. Stepwise regression analysis disclosed that systolic and diastolic blood pressure had significant correlation with age, serum Na+/K+ ratio and intralymphocytic Ca2+, Mg2+ concentrations (P < 0.001 for both). 3. According to hypertensive family history, the method of multiple variance analysis had been employed for 4 subgroups and the results revealed that the concentrations of serum Ca2+ and lymphocytic Na+ were significantly higher in hypertensives with or without family history than in normotensives without family history. Furthermore, intralymphocytic Na+ concentration was significantly higher in normotensives with positive family history than that in normotensives without family history. CONCLUSION: The serum and intralymphocytic distribution characteristics of elements in hypertensive patients compared with normotensive controls suggested that there might exist certain defects of the ion-transporting system on cell membrane which might be genetically linked.

Adult↗
PubMed1999

[The study of oxygen-conserving nasal cannula and evaluation of it's oxygen saving ratio in treatment].

OBJECTIVE: To study the oxygen-conserving nasal cannula(CNC), and to evaluate it's oxygen saving benefit ratio in COPD patients. METHODS: (1) CNC was designed as a device which conserved oxygen during exhalation and given oxygen during inhalation; (2) Evaluation of the effect of oxygen therapy: blood analysis was measured at different flows of oxygen (0.5, 1.0, 1.5, 2.0 L/min) before and after oxygen therapy. The test is randomized; Oxygen saturation(SPO2) was measured at 1, 2, 3, 5, 10, 15, 30, 60, 120 minutes by pulse oximeter; (3) Evaluation of the oxygen saving benefit ratio: SPO2 was measured at 0.5, 1.0, 1.5, 2.0, 2.5, 3.0 L/min using CNC, the standard nasal cannula (SCN) and the new CNC. RESULTS: (1) During two hours of oxygen therapy, the values of PaO2 and SaO2 in the CNC group were always higher than those in the SNC group (P < 0.05); (2) When the supply flow to CNC was set at 0.5 L/min, 1.0 L/min, 1.5 L/min, 2.0 L/min seperately, the oxygen saving benefit ratio of CNC to SNC was 2.6:1, 1.8:1, 1.8:1 and 1.5:1 respectively. (3) The oxygen saving benefit ratio was comparable between CNC made in China and that made in foreign country. CONCLUSIONS: It was confirmed that CNC saved oxygen at different flows of oxygen, and the oxygen saving benefit ratio was higher at lower flows than that at higher flows.

Adult↗
PubMed1999

[Cleaning cavity operation in treating relapse bacillary cavitary pulmonary tuberculosis].

OBJECTIVE: To study the effective surgical way for serious relapse multidrug resistant bacillary cavitary pulmonary tuberculosis. METHODS: 104 cases of serious relapse multidrug resistant bacillary cavitary pulmonary tuberculosis were cured by cleaning cavity operation from 1981 to 1998. The operation contained resecting the back rib covering the cavity, separating the intercostal tissue, cutting the external wall of the cavity, cleaning the cavity thoroughly, scraping the cavity till exposing the fresh tissue, killing the tuberculosis germs with organic acid, filling the cavity with the intercostal muscle, fixing and suturing the muscles. RESULTS: Among the 104 cases, 103 cases (99.0%) were cured, 101 cases (98.1%) were cured after the first operation, one case (1.0%) became better. Among the 98 cases followed up, the rate of returning to work were 96%, no one died or relapsed. CONCLUSIONS: The design of cleaning cavity operation is reasonable and it is the effective method to treat the relapse bacillary cavitary pulmonary tuberculosis, the rate of cure and sputum conversion are promising.

Adult↗
PubMed1999

[Differential diagnosis in patients with tuberculous meningitis and cryptococcal meningitis].

OBJECTIVE: To search for the main differential points in clinical and CSF changes between patients with tuberculous meningitis (TBM) and cryptococcal meningitis (CCM). METHODS: Fifty three cases of TBM and 55 cases of CCM who admitted to hospital from February 1983 to December 1997 were investigated retrospectively. Main symptoms, signs and CSF changes before administration of specific antibiotics were compared. RESULTS: 9%(5/53) TBM and 49% (27/55) CCM patients had headache without fever at the onset. The incidences of symptoms of failing eyesight, hearing loss and paralysis of extremities were 13% (7/53) and 36%(20/55), 2% (1/53) and 16% (9/55), and 19% (10/53) and 0 in TBM and CCM patients respectively. The rate and the degrees of optic papilla edema in CCM patients (66%, 16/36 slight, 13/36 moderate, and 7/36 serious) were significantly higher and more serious than that in TBM (15%, 8/8 slight). The patients with initial CSF pressure over 400 mm H2O were 11% and 90% in TBM and CCM. All but 20 CCM patients had elevation of CSF protein content, and 45% (24/53) TBM and 9%(5/55) CCM were > 2 g/L. CONCLUSIONS: This study shows that the most important differences between TBM and CCM are: headache not accompanied by fever at the onset, failing eyesight, striking elevation of initial CSF pressure, moderately and serious degree of optic papilla edema, normal CSF protein content occurs usually in CCM more than those in TBM patients. On the other hand, striking elevation of CSF protein content (> 2 g/L) occurs usually in TBM patients.

Adolescent↗
PubMed1999

[The value of "occult blood bead" in detection of upper digestive tract disorders with bleeding].

OBJECTIVE: To evaluate the usefulness of "occult blood bead" (OBB) test in the screening of gastric and esophageal cancers. METHODS: In the study, subjects with upper gastro-intestinal (GI) symptoms received gastric OBB test before gastroscopic examination. OBB test was scored as +(-)+++ according to the intensity of reactions. The sensitivity, specificity, and likelihood ratio of OBB test were evaluated according to results of gastroscopic and/or pathological examination. RESULTS: Among 5,217 subjects, 2,403 showed positive OBB test (46.1%). In this series, 202 cases of malignant disorders were detected (gastric cancer in 155 and esophageal cancer in 47). There were 69 cancer cases among 1847 subjects presenting "+" OBB test, with a cancer detection rate of 3.7%. In 393 subjects presenting "++" OBB test, 28 were cancer (7.1%); while in 163 subjects presenting "+++" OBB test, 34 were diagnosed as gastric or esophageal cancer with a detection rate of 20.9%. The sensitivity of OBB test in detection of gastric and esophageal cancer was 0.65, the specificity was 0.55, likelihood ratio was 1.43 and the Youden Index was 0.2. CONCLUSION: OBB test provides a new, simple and non-invasive method for detection of upper digestive tract bleeding. For detection of upper GI carcinomas it presents a reasonable sensitivity and specificity in a group of subjects with upper GI symptoms. OBB test can be used as a prelimnary screening tool for gastric and esophageal cancer in asymptomatic general population.

Adolescent↗
PubMed1999

[P-selectin and tachykinins in bronchial hyperresponsiveness of asthma].

OBJECTIVE: The characteristic feature of asthma is bronchial hyperresponsiveness (BHR). It is due predominately to inflammation of airways. Pathologically, there are inflammatory infiltration, epithelial sloughing and mucosal edema in the bronchi. The objective of this study is to investigate the relationship between BHR and airway inflammation. METHODS: 57 cases of asthma and 22 normal subjects were tested with bronchial reactivity examination and P-selectin, substance P (SP) and vasoactive intestinal peptide (VIP) in plasma. RESULTS: It was found that the bronchial reactivity to inhaled methacholine was positive in 53 of the 57 asthmatic patients (92.98%), while the remaining four were negative (7.02%). Twenty-two normal subjects were all negative with the test of bronchial reactivity. The levels of P-selectin and SP in asthmatics with corticosteroids treatment (n = 27) were higher than those in the control group (P < 0.05), but lower than those in asthmatics treated with aminophylline and salbutamol sulfate (n = 30), (P < 0.01). The concentration of VIP in asthmatics with corticosteroids treatment was significantly higher than that of asthmatics with out corticosteroids treatment (P < 0.01) but lower than that in the control group (P < 0.01). There was positive relationship between bronchial reactivity and P-selectin (r = 0.328, P < 0.05), as well as SP (r = 0.529, P < 0.01) in asthmatics, but negative relationship between bronchial reactivity and VIP (r = -0.419, P < 0.05). CONCLUSION: The increase of P-selectin and SP and decrease of VIP can induce BHR, corticosteroids can reduce levels of P-selectin, SP and enhance the level of VIP, therefore it can improve the reactivity of airway and relieve symptoms.

Adult↗
PubMed1999

[The effects of inhaled bronchodilators on central inspiratory drive in patients with COPD].

OBJECTIVE: To evaluate the effects of inhaled bronchodilators on the central inspiratory drive in patients with COPD. METHODS: 91 patients with COPD were divided into three groups (A, B, C) randomly. Lung functions and P(0.1) were measured at baseline and 20 min and 60 min after inhalation (A: albuterol; B: iprotropium; C: albuterol + iprotropium). RESULTS: P(0.1) decreased after inhalation in all three groups (P < 0.05 approximately 0.001). A positive correlation between DeltaP(0.1) and DeltaFRC was found in the three groups (r = 0.4325 - 0.5230, P < 0.05 approximately 0.01). V(E)/P(0.1) increased in the three groups after inhalation (P < 0.05 approximately 0.005). There was significant improvement of V(E)/P(0.1) in group B and C as compared with that of group A (P < 0.05, P < 0.001); There was a different correlative factor with V(E)/P(0.1) in group B and C. CONCLUSIONS: (1) P(0.1) decreased after inhalation, It may be caused by decreased FRC. (2) V(E)/P(0.1) became appropriate after inhalation in all groups; The improvement in group B and C was superior to that of group A. There may be different mechanisms to improve V(E)/P(0.1) by different inhalators.

Administration, Inhalation↗
PubMed1999

[Piezoelectric, electrohydraulic and electromagnetic shock wave lithotripsy for lower ureteral stone].

OBJECTIVE: To treat patients with lower ureteral stones by extracorporeal shock wave lithotripsy (ESWL) using piezoelectric, electrohydraulic and electromagnetic second lithotriptors. METHODS: Six hundred and three patients were divided into 3 groups according to the modes of lithotriptors. There were 179 patients in EDAP LTO1 piezoelectric group, 294 in JDPN IV electrohydraulic group and 130 in Dornier Compact S electromagnetic group. Every group was further divided into 3 subgroups with 10 mm, 10 - 15 mm and 15 mm in diameters of stones. RESULTS: The stone-free rate in single session of ESWL was higher in the electromagnetic group than in the other two groups. The efficiency quotient was lower in piezoelectric group than in the electrohydraulic and electromagnetic groups. The stone-free rate in single session was achieved in more than 70% of stones less than 15 mm in diameter for electromagnetic and electrohydraulic ESWL. CONCLUSIONS: The overall results of electromagnetic and electrohydraulic ESWL on lower ureteral stones are better than those of piezoelectric ESWL, and ESWL is suitable for stone less than 15 mm in diameter.

Adolescent↗
PubMed1999

[Extracorporeal shock wave lithotripsy in situ for middle ureteral stones].

OBJECTIVE: To report the experience with in situ ESWL for patients with middle ureteral stones. METHODS: 52 patients suffering from stones with an average 11 mm (range 5 - 20 mm) in dimension were treated using modified Puigvert technique in prone position via the entry route of lateral abdomen. The patients received 3,000 - 5,000 shocks per session at the power setting ranged from 2 to 7. RESULTS: The stone free rate at 3 months was achieved in 96% patients retreatment was performed in 30% patients. The therapeutic results were calculated as efficiency quotient being 74%. No severe complications occurred in all patients. CONCLUSIONS: In situ ESWL for middle ureteral stone is safe and effective and may serve as the first line therapy.

Adult↗
PubMed1999

[Allograft-prosthesis combination in limb salvage surgery].

OBJECTIVE: To study allograft-prosthesis combination in limb salvage and the rational of composite prosthesis. METHODS: Of 16 patients with bone tumors age from 19 to 60 years, 6 women 12 men, osteosarcoma was found in 4 patients, chondrosarcoma in 2, malignant giant cell tumor in 3, fibrosarcoma in 3, and other malignant bone tumor in 4. Allograft-prosthesis combination in included allograft proximal femurs with total hip arthroplasty (3 patients), allografts bipolar femoral head replacement (8), allografts with total knee arthroplasty prosthetic replacements (7). All patients received adjuvant therapy for tumor control. RESULTS: The length of follow-up ranged from 18 months to 5 years during which time 1 patients died, 3 survived as tumor-carriers, and 12 were disease free. All patients obtained better functional result in their extremities and had good quality of life. CONCLUSIONS: Both prosthetic replacement and allograft advantages, the use of large bone allografts with metallic prosthesis for the treatment of bone tumors near or involving joints can be applied with good results in selected patients having limb salvage surgery.

Adult↗