Biomedical subjects

Z Lu

Publications and source records attributed to Z Lu.

At least 163 records · Page 9Linked to original sources

PubMed2000

Assessment of autonomic function in patients with acute myocardial infarction or diabetes mellitus by heart rate variability, ventricular late potential and QT dispersion.

To compare the efficacy and sensitivity of heart rate variability (HRV), QT dispersion (QTd) and ventricular late potential (VLP) examination in judging autonomic function. Thirty three patients with acute myocardial infarction (AMI) and 33 patients with diabetes mellitus (DM), all of whom were diagnosed with autonomic neuropathy determined by a standard test of cardiovascular autonomic function, were examined by HRV (timing domain methods), QTd and VLP. Thirty three normal individuals served as controls. The mean SD of the normal R-R interval (SDNN) in both the AMI and DM groups was significantly less than that in the control group (p< 0.01); and of course, the QTd of these groups was significantly greater than that of the controls (p< 0.01). The VLP positive rate of the AMI and DM groups were much higher than that of the control group (p< 0.001). SDNN was shown to be significantly negatively correlated to QTd (r= -0.45); and significantly negatively correlated to VLP (r= -0.47); QTd was shown to be positively, though not significantly, correlated to VLP (r=0.48). QTd could be looked as sieving index; HRV could be looked as routine examination of cardiovascular autonomic function, especially SDNN; the combination of HRV and VLP could improve the accuracy of diagnosis.

Adult↗

PubMed2000

Isolation and characterization of the chicken vitamin D receptor gene and its promoter.

The sequences from several independent cDNA clones encoding the chicken vitamin D receptor as well as primer extension assay have clearly delineated the 5' terminus and the transcriptional start site. Screening a chicken genomic library produced genomic clones containing vitamin D receptor (VDR) gene fragments. Restriction map of clone 8 showed that the 18.6-kb chicken VDR fragment has exons 1 and 2, intron 1, part of intron 2, and 7-kb 5' flanking region. Exons 1, 2, and 3 found in the chicken VDR gene shares low homology with its mammalian counterparts (i.e., E1A, E1B, and E1C in human). By contrast, the fourth exon and following exons for the coding region of VDR gene are highly conserved between avian and mammalian species. While the fourth exon bears the ATG sites for translation initiation in mammals, the third exon in birds has two extra ATG sites for leaky translation as determined previously. Thus, the avian VDR has more N-terminal sequence than the mammalian VDR and is found in two distinct forms. The 5' flanking region from genomic clone 8 shares considerable homology in several regions with the human and mouse VDR promoters. Moreover, the 5' flanking region of chicken VDR gene possesses promoter activity, as shown by its ability to drive the luciferase reporter gene in cell transfection assays. Like other steroid receptor promoters, the chicken VDR promoter contains no TATA box but possesses several GC boxes or SP1 sites. A series of deletional promoter constructs established that the proximal GC boxes are the major drivers of gene transcription, while the more upstream sequences have repressive elements.

Animals↗

PubMed2000

[The application of polymerase chain reaction-single strain conformation polymorphism in the pedigree analysis of familial hypercholerolemia patients].

OBJECTIVE: To discuss the value of polymerase chain reaction-single strand conformation polymorphism(PCR-SSCP) in the pedigree analysis of familial hypercholesterolemia(FH) patients. METHODS: For 4 patients with FH detected by PCR-SSCP and DNA sequence analysis (1 homozygote has point mutation in exon 7, 1 heterozygote in exon 14, and 2 heterozygotes in 3' part of exon 4 ), members of each pedigree, altogether 23 individuals, were analysed using PCR-SSCP. RESULTS: Every member of the 4 pedigrees was examined genetically. Besides the 4 probands, another 1 homozygote and 8 heterozygotes were found. CONCLUSION: The PCR-SSCP method can be used in the pedigree analysis of FH probands. The early diagnosis of siblings and relatives can help to provide genetic consultation and direction so as to pay attention to development of hypercholesterolemia.

Adolescent↗

PubMed2000

Immobilization of antibodies on ultraflat polystyrene surfaces.

BACKGROUND: Functional antibody surfaces were prepared on ultraflat polystyrene surfaces by physical adsorption, and the uniform distribution of monoclonal antibodies against hepatitis B surface antigen (anti-HBs) on such surfaces and the presence of dense hepatitis B surface antigen (HBsAg) particles captured by immobilized antibodies were identified. METHODS: A model polystyrene film was spin-coated directly onto a silicon wafer surface. Atomic force microscopy was used to directly monitor the immobilization of anti-HBs antibodies and their specific molecular interaction with HBsAg. Enzyme immunoassay was also used to characterize functional antibody surfaces. RESULTS: A mean roughness of 2 A for areas of 25 microm(2) was produced. We found a uniform distribution of anti-HBs antibodies on ultraflat polystyrene surfaces and the presence of dense HBsAg particles bound to such anti-HBs surfaces after incubation with HBsAg. CONCLUSIONS: This study confirmed the potential of preparing dense, homogeneous, highly specific, and highly stable antibody surfaces by immobilizing antibodies on polystyrene surfaces with controlled roughness. It is expected that such biofunctional surfaces could be of interest for the development of new solid-phase immunoassay techniques and biosensor techniques.

Adsorption↗

PubMed2000

[Expression of ras oncogene p21 product and proliferating cell nuclear antigen in liver cirrhosis and the correlation with liver cell dysplasia].

OBJECTIVE: To probe the role of ras oncogene p21 product, proliferating cell nuclear antigen (PCNA) and hepatitis B virus infection in the development of cirrhotic nodules, liver cell dysplasia and hepatocellular carcinoma (HCC). METHODS: S-P immunohistochemical technique was used to analyze the expression of p21, PCNA and HBsAg was studied in 30 cases of cirrhosis with HCC and 60 cases without HCC and 27 HCC cases. RESULTS: The positive rates for p21 in cirrhosis with or without HCC, and HCC tissue were 90%, 68.33%, and 62.96%, respectively. The positive rates for p21, PCNA and HBsAg in cirrhotic nodules with LCD were 92.45%, 73.59% and 64.92%, respectively, significantly higher than those without LCD (P<0.05). The incidence of p21 expression in hepatocytes was significantly higher in HBsAg- and PCNA positive cases than in negative ones (P<0.01). CONCLUSION: (1)The overexpression of p21 may play an important role in the early stage of the development of HCC; (2)LCD are precancerous cells which have the ability to initiate neoplastic growth and present a high risk of development of HCC especially combining HBV infection and the overexpression of p21 and PCNA. (3)The expression level of p21 in liver cirrhosis is related to HBV infection and the expression level of PCNA.

Adolescent↗

PubMed2000

[The expression, secretion and regulation of membrane-soluble syndecan-1 in human multiple myeloma cells].

OBJECTIVE: To analyze the expression, secretion and regulation of membrane-soluble syndecan-1 in human multiple myeloma cells, and to explore the relationship between syndecan-1 and the development of human multiple myeloma. METHODS: Syndecan-1 expression on the surface of malignant plasma cells was analyzed by immuno-staining, the levels of soluble syndecan-1 in the supernatant of cultured tumor cells by ELISA. RESULTS: 1. Human multiple myeloma cells expressed high levels of syndecan-1. The density of syndecan-1 varied from 170,000 to 800,000 molecules per cell. The expression of syndecan-1 lost rapidly as the cells underwent apoptosis. 2. Most myeloma cells produced soluble syndecan-1, the rate of production did not correlate with the density of membrane syndecan-1. Moreover, the production of soluble syndecan-1 did not require serum. 3. The protein synthesis inhibitor cycloheximide inhibited the production of syndecan-1. The serine protease inhibitor antipain did not affect the secretion of syndecan-1. CONCLUSION: As a receptor of many growth factors, cytokines and heparin-like growth factors, syndecan-1 might play an important role in tumor cell growth and homing in multiple myeloma development.

Humans↗

PubMed2000

[The studies on protective effects of SM against myocardial hypoxia/reoxygenation injury].

AIM AND METHODS: To assess the myocardial effects of Salvia Miltiorrhiza (SM) injection against hypoxia-reoxygenation injury, 31P NMR was used to trace the time courses of high energy phosphates (HEP) content and intracellular pH (pHi) of the isolated perfused rat hearts under hypoxia (30 min) and subsequent reoxygenation (40 min). RESULTS: It was discovered that SM significantly preven-ted the decrease in the myocardial HEP content during hypoxia, enhanced the recovery of myocardial phosphocreatine (PCr), adenosine triphosphate (ATP) and the PCr/Pi (inorganic phosphate) ratios during reoxygenation, and lightened the decrease of the myocardial pHi value caused by hypoxia. CONCLUSION: SM improves the myocardial energy metabolism level during prolonged hypoxia and subsequent reoxygenation and protects myocardium against hypoxia/reoxygenation injury. SM significantly attenuates acidosis during hypoxia and prevents the appearance of very acidic areas of the myocardium after reoxygenation.

Animals↗

PubMed2000

[Evaluation of performance and blood compatibility of polyethersulfone hollow fiber plasma separator].

In this study, we evaluated the performance and blood compatibility of polyethersulfone hollow fiber membrane plasma separator by animal experiment. Hemolysis did not occur under the usual conditions of plasma separation. The sieving coefficients of total protein, albumin and globulin were over 95%, and about 60% of total plasma were extracted from the whole blood. White blood cells, platelets, fibrinogen, and coagulation factors were decreased during the early stage of plasma separation and appeared to be within acceptable ranges for clinical use.

Animals↗

PubMed2000

[Effect of temperature and food on Spodoptera litura population].

The relationship between temperature and development of Spodoptera litura was simulated by the sine model V(T) = A + B sin(C0 + C1eC3T + C2e-C3T), and the threshold temperature and thermal requirement for its development at different stages were estimated by the direct optimum method. The model for the relationship between temperature and survival rate was fitted by the experimental data. The theoretical optimum temperature for the development of eggs, young instar larvae, old instar larvae and pupae was 26.7, 24.7, 24.9 and 25.8 degrees C, respectively. The life table parameters under different feed conditions (cabbage, lotus, sweet potato, soybean leaves) were estimated by the method of bisexual life table with age-structure. At temperature 25 degrees C, the intrinsic rates of increase under the four different feed conidtions were 0.1836, 0.1719, 0.1778 and 0.1206, respectively.

Animals↗

PubMed2000

[Tolerance of various geographic populations of brown planthopper to adverse environmental stresses].

The populations of brown planthopper(BPH), Nilaparvata lugens, were collected from Zhejiang, Guangxi and Yunnan provinces to study their tolerance to various adverse environmental stresses. The results indicated that all of these three populations could adapt to the rice variety IR26 bearing resistant gene 1 (Bph1), and Guangxi and Yunnan populations could successfully infest rice varieties ASD7 bearing bph2 and Rathu Heenati bearing Bph3, implying that these two populations had a higher adaptability to resistant rice varieties. The significantly negative relationship between female brachypterous rate and nymphal density in Zhejiang population showed a lower tolerance to high nymphal density of Zhejiang population than that of Guangxi and Yunnan populations. A higher resistance to high temperature and a lower tolerance to starvation were obviously found in Guangxi and Yunnan populations. The resistance to insecticide (Omethoate) of Zhejiang population was little higher than that of Guangxi population. It was suggested that the tolerance of different geographic populations of BPH to various adverse environmental stresses be closely related to their habitat characteristics.

Animals↗

PubMed2000

[Hunger tolerance of Microvelia horvathi hibernating generation].

The experimental results showed that the hunger tolerance (HT) of different wing forms Microvelia horvathi adults had significant difference at 14-32 degrees C, and decreased with increasing temperature, which was 32.10 and 29.58 days at 14 degrees C, and 9.46 and 7.82 days at 32 degrees C, respectively for apterous and pterygote adults. The HT of apterous adults was higher than that of pterygote ones, and females was higher than males with the same wing form. The lower the temperature, the bigger the difference. The HT of M. horvathi adults differed obviously with densities. 1 female 1 male per bottle had a higher HT than 5 females 5 males per bottle and 10 females 10 males per bottle, while no difference was found between two latter densities. The HT of the 1st instar nymphs of M. horvathi had an obvious difference at different temperatures, which was significantly higher at 14 and 20 degrees C than at 26 and 32 degrees C.

Animals↗

PubMed2000

Effect of Q-switched alexandrite laser irradiation on dermal melanocytes of nevus of Ota.

OBJECTIVE: To investigate the effect of Q-switched alexandrite laser irradiation on dermal melanocytes of nevus of Ota. METHODS: Multiple biopsies were carried out on 4 patients with nevus of Ota before and after laser irradiation. Altogether 11 samples were examined under light microscope and 14 under transmission electron microscope. RESULTS: Immediately after laser irradiation, the dermal melanocytes were destroyed, the melanosomes were degenerated with central vesicle formation within most of them, and intradermal round vacuoles appeared. The epidermis remained intact. Three months to 1 year after irradiation, the degenerated melanosomes and cell debris were scavenged mainly by macrophages. Dermal melanocytes gradually decreased. No fibrosis was found. CONCLUSION: Q-switched alexandrite laser can selectively destroy dermal melanocytes of nevus of Ota and treat the disease safely.

Adolescent↗

PubMed2000

Embolic events in 93 elderly Chinese patients with atrial fibrillation.

OBJECTIVES: To evaluate the prevalence of embolic events and relevant factors in elderly Chinese patients with atrial fibrillation(AF), and to provide evidence on ways to prevent embolic events. METHODS: Autopsy data from ninety-three continous elderly Chinese patients with AF were analysed. The incidence of embolic events and its relationship to underlying disease, pathologic changes in the heart, and other clinical characteristics were examined. RESULTS: Embolism were observed in 27 of 93 cases, with an incidence of 29.03%. The incidence of embolic events was higher in elderly patients with rheumatic heart disease than those with coronary artery disease, hypertensive myocardiopathy and heart diseases. Patients with chronic AF, with a course of AF > or = 3 years, and those with heart failure or diabetes had a higher incidence of embolic events than those without these complications. There was significant difference in incidence between paroxysmal and chronic AF. Patients with left atrial or ventricular enlargement, mural thrombosis in cardiac chambers, valvular calcification and valvular vegetation also had a higher incidence of embolic events. Oral dipyridamole (75-150 mg/d) or aspirin (50-150 mg/d) showed no definite effects in preventing embolism in some patients. CONCLUSIONS: There was a high incidence of embolic events in elderly Chinese patients with AF. Anticoagulation therapy should be provided to the elderly patients with AF, especially to the patients with risk factors for embolism.

Aged↗

PubMed2000

Relationship between serum or tissue ouabain and blood pressure in 1k1c hypertensive rats.

OBJECTIVE: To evaluate the role of endogenous ouabain (EO) in the development of hypertension and the characteristics of EO secretion in 1k1c (one kidney, one clipped) hypertensive rats. METHODS: EO content of serum and tissues in 1k1c hypertensive rats and normal control Sprague-Dawley (SD) rats was detected by the method of enzyme linked immunosorbent assay (ELISA). The relationship between serum or tissue ouabain and blood pressure was analyzed in 1k1c hypertensive rats. RESULTS: The ouabain content of serum, heart, kidney, adrenal gland, pituitary and hypothalamus was significantly higher in 1k1c hypertensive rats than that in normal control SD rats (2.25, 2.63, 3.35, 40.37, 3.34, 15.7 micrograms/kg tissue in 1k1c hypertensive rats vs 1.12, 1.79, 1.73, 27.54, 1.83, 10.10 micrograms/kg tissue in control SD rats, respectively. P < 0.05 for all of these comparisons). The ouabain content of the adrenal gland and the hypothalamus was higher than that of other tissues or serum, both in 1k1c rats and in control SD rats. The EO content of serum, kidney and hypothalamus was significantly correlated with blood pressure in 1k1c hypertensive rats (r = 0.59, 0.63, 0.52, respectively. P < 0.05). The ouabain content of heart, liver, adrenal gland and pituitary was not correlated with blood pressure. CONCLUSIONS: EO might play an important role in the development of hypertension in 1k1c hypertensive rats. The adrenal gland may be a major source of EO and the hypothalamus-pituitary-adrenal axis may be involved in the regulation of EO secretion.

Animals↗

PubMed2000

Detection of hepatitis B virus polymerase variations resistant to lamivudine therapy.

OBJECTIVE: To investigate variations in hepatitis B virus (HBV) polymerase gene in chronic HBV infected patients resistant to lamivudine therapy. METHODS: Specimens were obtained from nine patients with chronic HBV infection, who were resistant to lamivudine therapy. Partial segments of the HBV DNA polymerase gene were amplified by polymerase chain reaction (PCR). Nucleotide sequence was performed using an applied 373 automated sequencer. Titre of HBV DNA was measured by branched-DNA assay (Chiron). RESULTS: Of nine patients with HBV DNA positive after 64 weeks of treatment, five (56%) had variations in the highly conserved YMDD motif in domain C of the HBV polymerase, three of those were substitutions of isoleucine for methionine (M), and two were substitutions of valine(V) for methionine. Additionally, in two patients with variations characterized by substitutions of V for M, one had a simultaneous amino acid change from the first aspartic acid to glycine and this pattern of variation was not reported in other literatures. With respect to virernia, in two subjects with low titre of HBV DNA (< 100 MEq/ml), no variation was found in the YMDD motif, whereas in seven patients with high titre of HBV DBA (> 300 MEq/ml), five (71%) had variations in the YMDD motif. CONCLUSIONS: Lamivudine is a potent anti-viral agent for treatment of chronic HBV infection. Resistance to lamivudine is likely caused by the variations in the YMDD motif of the HBV polymerase gene.

Antiviral Agents↗

PubMed2000

[Local chemotherapy by fibrobronchoscopy for advanced bronchogenic carcinoma].

OBJECTIVE: To observe the effectiveness of treatment in the patients with advanced bronchogenic carcinoma of local chemotherapy with fibrobronchoscopy, combined with systematic chemotherapy. METHODS: 40 patients with advanced bronchogenic carcinoma were divided into the tested group (20 patients) and the control group (20 patients) randomly. By fibrobronchoscopy with its matched injecting needle, carboplatin 300 mg were injected into the centre of the tumor and the surroundings, combined with the routine carboplatin and etoposide (CE) regimen. While the control group was treated only by intravenous chemotherapy with the routine CE regimen. RESULTS: In the 20 patients with local chemotherapy by fibrobronchoscopy combined with intravenous chemotherapy, 7 cases (35%) were completely cured and 11 cases (55%) showed partial recovery, other 2 cases without change. The 90% effective rate was significantly higher than 55% of the control group (P < 0.05). CONCLUSIONS: The local chemotherapy by fibrobronchoscopy can remarkably reduce the size of tumor, and relieve symptom of dyspnea. Intravenous chemotherapy alleviated the obstruction caused by tracheal or bronchial neoplasms. The combined therapies led to much better therapeutic effect and symptomatic relief than those by the routine CE regimen.

Aged↗

PubMed2000

[Study on blood coagulant/fibrinolytic activity at plasma and monocytic levels in coronary heart disease patients with Blood-Stasis Syndrome of traditional Chinese medicine].

OBJECTIVE: To explore and compare the changes of coagulant/fibrinolytic activity in coronary heart disease (CHD) patients with Blood Stasis Syndrome of TCM and evaluate the roles of these changes. METHODS: Eighty patients of CHD were divided into two groups by Syndrome Differentiation of TCM, the Blood-Stasis (BS) group (30 cases) and the non-Blood-Stasis (NBS) group (50 cases, including 27 cases of Phlegm-Dampness Syndrome and 23 cases of Qi-Stagnation Syndrome); and 20 healthy persons were enrolled as normal control group. Tissue type plasminogen activator (t-PA) and its inhibitor (PAI-1) in plasma and in human peripheral blood monocyte cell (PBMC), as well as the procoagulant activity (PCA) in PBMC were measured by chromogenic substrate method. RESULTS: The plasma PAI-1 activity and PCA of PBMC in the BS group were significantly higher than those in the NBS group and the normal control group (P < 0.01). PAI-1 activity of PBMC in the two groups of CHD patients was higher than those in the normal control group significantly (P < 0.01), but no significant difference was found between the BS group and the NBS group (P > 0.05). The difference of plasma t-PA activity between the two groups of CHD was insignificant. The PBMC t-PA activity in the BS group was lower than that in the NBS and normal control groups (P < 0.01). CONCLUSION: In the CHD patients with BS, the PBMC PCA was increased and the fibrinolytic activity at both plasma and monocyte levels lowered significantly, these changes in coagulant/fibrinolytic activity may be the important pathologic factors in forming BS which suggests that CHD patients with BS were in the prothrombotic state.

Adult↗

PubMed2000

[Seeking behavior of patients with mental disorders and interfering factors].

OBJECTIVE: To approach different help-seeking behavior and its effects on patients with mental illness. METHODS: We investigated the patients first seeking help in psychiatry department, by applying the scale of help-seeking behavior of mental illness. RESULTS: There were significant differences among different mental disorders. 50% patients with mania, 66% with schizophrenia, and about 90% with depression or neurosis first went to general hospital when their illness began. About 80% patients considered their symptoms as normal, temperament, and mood problems. The course of one-third patients was one year, and most patients were treated with traditional herbs, west drugs and tests. Nearly 10% patients with depression, neurosis and schizophrenia spent more then 10 000 yuan before seeking the doctor in psychiatry. CONCLUSION: Now then it is still a main problem for patients with mental disorders in seeking behavior. We suggest that the propaganda of the knowledge of mental health should be paid more attention, especially for the people in community and doctors in general hospital.

Bipolar Disorder↗