Biomedical subjects

L Zhang

Publications and source records attributed to L Zhang.

At least 523 records · Page 29Linked to original sources

PubMed2001

[Study on the distribution of lymphocyte subsets in the eutopic and ectopic endometrium of women with endometriosis].

OBJECTIVE: To investigate the abnormal distribution of lymphocytes in eutopic and ectopic endometrium of patients with endometriosis and its significance. METHODS: In 43 cases, biopsies of ectopic tissues were taken by laparoscopy and laparotomy from patients with endometriosis and eutopic endometrium by curettage at the same time. In 19 cases, eutopic endometrium was taken from hysterectomy for myomatous uterus. Immunohistochemical techniques were employed to demonstrate the difference in the number and ratio of the lymphocyte subsets between the patients with endometriosis and the controls. RESULTS: In the patients with endometriosis, in the proliferative phase, ectopic endometrium contained respectively CD3+ CD8+ T cells and CD68+ macrophages (67.2 +/- 13.5)/5 HP, (45.0 +/- 14.0)/5 HP and (37.2 +/- 10.6)/5 HP, significantly higher then that in the eutopic endometrium (52.4 +/- 11.3)/5 HP (P < 0.01), (32.5 +/- 10.0)/5 HP (P < 0.05), and (30.7 +/- 10.3)/5 HP, and also higher as compared with the control group (52.1 +/- 14.9)/5 HP (P < 0.05), (28.9 +/- 12.7)/5 HP (P < 0.01), (26.3 +/- 9.3)/5 HP (P < 0.05); in the secretory phade, CD8+/CD4+, and CD68+ content was respectively 3.5 +/- 1.2, (40.3 +/- 12.2)/5 HP, higher than that in the control group, 3.2 +/- 0.8 (P < 0.05), (28.6 +/- 10.6)/5 HP (P < 0.01). The number of macrophages was also significantly increased. No cyclic changes in the number of lymphocytes in each subpopulation in ectopic endometrium were found. CONCLUSIONS: In the patients with endometriosis, the changes in T lymphocytes and macrophages are mainly on the endometriotic sites. The infiltration of many lymphocytes and macrophages into the ectopic endometrium formed a chronic inflammatory process. The lymphocytes are not able to clear the ectopic endometrium in the late stages of endometrium, on the contrary, they stimulate the further growth of the endometrium.

Adult↗

PubMed2001

[The effect of human follicular fluid on mouse embryo culture].

OBJECTIVE: To evaluate the effect of human follicular fluid (HFF) on mouse embryo culture. METHODS: Compare the effects of HFF and serum as a protein supplement on the in vitro development of mouse embryos. Measure the concentration of the epidermal growth factor (EGF) in HFF and human serum. RESULTS: HFF significantly enhanced the developmental potential of mouse embryos in vitro, even in the presence of meiotic inhibitors. HFF significantly increased frequency of development from the 2-cell stage to the 8-cell stage (72.9%), blastocyst stage (50.9%) and hatching (26.3%), compared with human serum(48.0%, 24.5%, 6.9%, P < 0.05). There was higher concentration of EGF with an average of 0.50 microgram/L in HFF group compared with human serum (0.26 microgram/L, P < 0.05). CONCLUSION: Human follicular fluid is effective in increasing the developmental potential of mouse embryos in vitro.

Animals↗

PubMed2001

[Study of the pulmonary heart disease computer-aided diagnosis system based on combining neural network].

We have constructed an expert sub-system for diagnosing pulmonary heart disease with back-propagation (BP) model of typical artificial neural network and BP-Hamming. The system can obtain and represent clinical data, and it has solved the problems such as obtaining automatic knowledge, representation and self-learning. The results of testing demonstrate that the method of neural network can be regarded as an expert sub-system to make intelligent diagnosis of pulmonary heart disease.

Algorithms↗

PubMed2001

[Association of vascular endothelial growth factor expression with angiogenesis and tumor cell proliferation in human lung cancer].

OBJECTIVE: To evaluate the expression of vascular endothelial growth factor (VEGF) and the relation with angiogenesis and tumor cell proliferation in human lung cancer. METHODS: Expression of VEGF, angiogenesis, tumor cell proliferation in 63 cases of human lung cancer were examined immunohistochemically. Anti-VEGF(165)-Ab3 was used for VEGF expression, a monoclonal antibody directed against CD(34) to identify intratumoral microvessel density (iMVD) and the proliferating cell nuclear antigen (PCNA) as a marker of proliferating tumor cells. RESULTS: Positive staining for VEGF was obtained in 32 of the 63 cases (50.8%), iMVD varied from 4 to 138.7 (M = 36)/x 400 and the proportion of PCNA positive cells varied from 0 to 92% (M = 25.03%). iMVD in high-grade VEGF tumors was significantly higher than that in VEGF-negative tumors and low-grade VEGF tumors. PCNA labeling proliferation index in small cell lung cancer was higher than that in non-small cell lung cancer. iMVD significantly increased with increasing VEGF expression. CONCLUSION: There is VEGF expression in lung cancer. VEGF expression is significantly associated with iMVD, but there is no association between iMVD or VEGF expression and PCNA expression. There is no association between VEGF expression and histological classification and clinical stages.

Adult↗

PubMed2001

[Renal protective effects of vitamin E in diabetic rats].

OBJECTIVE: To investigate the renal protective effect of vitamin E on streptozotocin induced diabetic rats, as well as the possible mechanism involved in. METHODS: Vitamin E 20 mg x kg(-1) x d(-1) was given to diabetic rats for 8 weeks. Urinary albumin excretion (UAE) was measured by radioimmunoassay. The changes of creatinine clearance rate (Ccr), nitric oxide(NO), nitric oxide synthase (NOS) and endothelin(ET) in the plasma and renal cortical tissue, membrane protein kinase C(PKC) in the renal glomeruli were observed. RESULTS: At two weeks, diabetic rats had supernormal Ccr[(6.47 +/- 1.51) ml x min(-1) x kg(-1)], UAE[(15.60 +/- 1.64) microg/24h], NO[(37.30 +/- 3.77) micromol/L], NOS[(34.89 +/- 3.83) U/L] and PKC[(86.85 +/- 11.37) pmol x min(-1) x mg protein(-1)] of diabetic rats were increase but ET was decreased. At 8 weeks, PKC[(84.18 +/- 12.14 ) pmol x min(-1) x mg protein(-1)] and ET of diabetic rats was increased significantly, but NO[(22.75 +/- 2.89) micromol/L] and NOS[(21.34 +/- 1.92) U/L] of diabetic rats was lowered. After treated with vitamin E, Ccr[(4.46 +/- 0.49) ml x min(-1) x kg(-1)], UAE[(16.31 +/- 1.12) microg/24h], PKC[(65.19 +/- 8.83) pmol x min(-1) x mg protein(-1)] at 8 weeks were decreased significantly. Both NO[(33.13 +/- 3.77) micromol/L] and NOS[(30.16 +/- 2.89) U/L] in plasma and kidney tissue were lowered as compared with untreated diabetic group in two weeks. Vitamin E also delayed the NO and NOS lowering in 8 weeks. CONCLUSION: Vitamin E could ameliorate early diabetic renal hemodynamic abnormality via inhibiting PKC, in which inhibition of NO production might be involved. It is important to reduced the PKC activity so as to prevent or delay the development of diabetic nephropathy.

Animals↗

PubMed2001

[A study of survival motor neuron and neuronal apoptosis inhibitory protein gene in spinal muscular atrophy].

OBJECTIVE: To study the absence of survival motor neuron(SMN) gene exon 7,8 and neuronal apoptosis inhibitory protein(NAIP) gene exon 5,6 in Chinese patients with type I - IV spinal muscular atrophy (SMA) and to confirm the relationship between the deletions of SMN, NAIP and SMA phenotype. METHODS: PCR and PCR-enzyme methods were used to detect the deletions of NAIP gene exon 5,6 and SMN gene exon 7,8 in 45 SMA (I - IV) patients and 30 healthy relatives of the patients and 30 normal controls. RESULTS: Deletions of exon 7 and 8 of the telomeric SMN gene were 4/4, 2/3, 1/8 and 0/30 in type I, II, III and IV SMA patients, respectively. One patient with type II lacked the exon 7 but retained exon 8. No deletions was found in the relatives and controls(0/60). No deletions of exon 5 and 6 of the NAIP gene was detected in all the patients, healthy relatives and controls. CONCLUSIONS: Deletions of SMN gene exon 7 and 8 exa mined by PCR-enzyme digestion could be recommended as an accurate gene diagnostic method for SMA with type I and II. However, the method was not as useful in type III as in I and II for making a diagnosis of SMA. Type IV SMA, a heterogeneous disease with phenotypical similarities to type I - III SMA, may be caused by deletion of other genes. The frequency of NAIP deletion was lower in Chinese SMA patients.

Child↗

PubMed2001

[Autoantibodies against the myocardium beta 1-adrenergic and M2-muscarinic receptors in patients with heart failure].

OBJECTIVE: To determine whether the autoantibodies against beta(1)-adrenergic and M(2)-muscarinic receptors are related to congestive heart failure (CHF) patients with different cardiac diseases. METHODS: Both synthetic peptides corresponding to amino acids sequence of the second extracellular loops of the beta(1) and M(2) receptors were used as the antigens to screen the serum from CHF patients with ischemic cardiomyopathy (ICD, n = 42), idiopathic dilated cardiomyopathy (IDCM, n = 52) and hypertensive heart disease (HHD, n = 44). Meanwhile healthy donors were tested as normal controls (NC, n = 40). RESULTS: The positive rates of serum for beta(1)-adrenergic-receptor were 45.7% (86/188) and 10.4% (8/77) in CHF patients and controls respectively (P < 0.01); the positive rates of serum for M(2)-muscarinic receptor were 52.7% (99/188) and 11.7% (9/77) in CHF patients and controls (P < 0.01). The frequencies of the both receptor autoantibodies in patients with cardiac function of class II approximately III were significantly higher than those with cardiac function of class VI. CONCLUSIONS: Our finding indicates indicates that autoantibodies against beta(1)-adrenergic-receptor and M(2)-muscarinic receptor can be detected not only in the serum of CHF patients with IDCM, but also in CHF patients with ICM and HHD. It is suspected that autoantibodies against beta(1) and M(2) receptors may be related to the myocardial remodeling and/or CHF.

Adult↗

PubMed2001

[Effect of Cu and As and their combination pollution on Glycine max].

Experiments are carried out with hoagland cultivation to study the effects of Cu and As and their interactions on the germination and seedling growth of Glycine max. The results show that Cu or As pollution reduced proteinase activities, inhibited the seedling growth and the respiration rate of germinating seed of soybean. The inhibition increased as Cu and As concentration increased, POD activities increased with increasing Cu and As concentration. Cu pollution has an antagonistic effect against the pollution of As, and vise versa.

Arsenic↗

PubMed2001

[Photosynthetic characteristics of two plagiomnium mosses in summer and winter].

A comparative study on the photosynthetic characteristics of Plagiomnium acuium(Lindb.) T. Kop. and P. maximoviozii(Lindb.) T. Kp., two overwintering host mosses for Chinese gall aphid(Schlechtendalia chinensis), was conducted by using CI-301PS in Summer and Winter. The results showed that the photosynthetic capacity of these two mosses species was 125.67 and 94.63 mumol CO2.kg-1DW.s-1 in Summer, and 58.1 and 62.1 mumol CO2.kg-1DW.s-1 in Winter, respectively. The dark respiration rates of these two species in Summer significantly exceeded those in Winter. The light complementary point of these two mosses species was in the range from 20 to 40 mumol.m-2.s-1, and light saturated point was from 200 to 400 mumol.m-2.s-1, with higher value in Summer and lower value in Winter. Their apparent quantum yields were 1.535 and 1.559 in Summer, but only 0.456 and 0.459 in Winter. The optimum temperature for photosynthesis of these two mosses species was 20 to 35 degrees C, also higher in Summer and lower in Winter. No matter which species and growing season, the temperature coefficients(Q10) measured in the range of 0-20 degrees C were similar, ranging from 1.15 to 1.23. These two moss species could maintain a certain net photosynthesis for 10-30 minutes under temperature stress from -15 to -10 degrees C and from 40 to 45 degrees C.

Animals↗

PubMed2001

[Changes of crop yields and soil fertility under long-term application of fertilizer and recycled nutrients in manure on a black soil].

The results from a field experiment over thirteen years on a black soil in Northeast China indicated that nitrogen fertilizer increased crop yields by 724 kg.hm-2 per year on average, with an increase rate of 27.5% and about 9.4 kg increased yield from 1 kg applied N. In the early stage, the crop yields almost gave no response to phosphorus fertilizer, owing to the high level of soil available phosphorus at the beginning of the experiment. The average increase of crop yields by phosphorus in thirteen years was only 241 kg.hm-2 per year, with an increase rate of 7%, about 12.7 kg increased yield from 1 kg applied P. Annual application of recycled pig manure made by 80% of harvested grain fed to pigs and the stolks as bedding materials could increase crop yields by 268, 258 and 255 kg.hm-2 per year with an increase rate of 9.8%, 7.6% and 7.0%, based on no fertilizer, with N and with P and N, respectively. There was a trend that the effect of recycled manure on crop yield was gradually increased during the period of experiment, implying the existence of accumulative residual effect from the manure.

Agriculture↗

PubMed2001

[Determination of ferulic acid absorbed into human serum from oral decoction of rhizoma chuanxiong and pharmacokinetic study of ferulic acid].

OBJECTIVE: To improve the HPLC method for determining ferulic acid(FA) in the human serum and to research FA clinical pharmacokinetics. METHOD: Serum concentrations of FA were determined by HPLC using methanol-water-acetic acid (40:59.7:0.3, v/v) as the mobile phase and the column packed with ODS (150 mm x 4.6 mm, 5 microns) as a fixed phase and the flow rate was 1.0 ml/min. FA was detected at 320 nm wave length. The internal standard was coumarin. The serum samples were treated by the water-boiling method. Peak of FA in serum was recognized by photodiode-array detection. RESULT: FA and internal standard were separated completely under the condition described as above. FA was linear in the range of (40.16-8032 ng/ml) (r = 0.9975). The CV was less than 10%, the average recovery was 100.3%, and the limit concentration in serum was 25.1 ng/ml. PK was in accordance with open bicameral model. CONCLUSION: This method can be applied to clinical pharmacokinetic study of FA.

Adult↗

PubMed2001

Observation of wounding characteristics in dogs wounded by super velocity projectile.

OBJECTIVE: To understand wounding characteristics in dogs wounded by super velocity projectile with a purpose of providing a basis for prevention and treatment of such wounds. METHODS: A specially-made explosive gun was used to shoot aluminium bullet weighing 3.0 g and 1.4 g to injure both legs of dogs at velocities of 2330 m/s, 3200 m/s and 4250 m/s, respectively, and the soap specially made was also shot. At the same time, steel ball of 1.03 g was shot with a Type 53 smooth chamber gun at a speed of 1280 m/s. Within 30 min after wounding, debridement and pathological anatomy were performed and specimens were taken for light microscope observation. RESULTS: When the dogs were wounded by the 3 g bullet at speed of 2330 m/s, the entrance of the left leg was penetrated explosively with a defect area of 225 cm(2), and the femur trunk was also injured and the residual femur had comminution fracture. The exit of the right leg was blindly wounded with a defect area of 63 cm(2), but only the skin was not penetrated. Both testes and part pelvis were injured too. Under light microscope, degenerative myofibers and bleeding of the spatium between the myofibers could be found at the place 4 cm away from the wounding track. Furthermore, serious bleeding of the bladder and blood vessels of the brain could be observed. The lungs showed changes of blast injury. Vacuolar change was presented in the cytoplasm of hepatocytes. Injuries of the animals in other two experimental groups were similar to those described above, but the defect area of the wounded track was 124 cm(2) in the group of 4250 m/s. Injuries caused by the steel ball were milder than caused by the explosive gun. The volume of the residual cavity in the soap was 5000 ml. CONCLUSIONS: The super-velocity projectile causes destructive damage to the local tissues and multi-organ injuries. Therefore, the practical medical care needs not only amputation but also management of multi-organ injuries.

Animals↗

PubMed2001

[cDNA expression array in the differential expression profiles of p53 regulated genes in nasopharyngeal carcinoma and the human normal nasopharynx].

OBJECTIVE: To compare the gene expression map of nasopharyngeal carcinoma (NPC) tissue with that of the control tissue by cDNA array and to discuss possible reasons of TP53 accumulation in NPC tissue. METHODS: After the hybridization of Atlas human cancer cDNA expression array 7742-1, analysis of Atlas arrays by means of AtlasImage 1.01a was carried out. Then, the results of array were verified by reverse transcription-polymerase chain reaction (RT-PCR). Gene expression alteration on the protein level was verified by immunohistochemistry. RESULTS: 134 of 588 tumor-related genes were upregulated and 88 downregulated. Thirteen of 32 p53-regulated genes showed differential expression with 11 upregulated and 2 downregulated. CONCLUSION: (1) p53 dysfunction exists in NPC tissues, (2) MDM2, p21 and Bax may be involved in the regulation of nasopharyngeal carcinoma cell growth.

DNA, Complementary↗

PubMed2001

[Analyses on the risk factors of Measles in Anhui province during 1998 and 1999].

OBJECTIVE: To evaluate the measures targeting measles control. METHODS: Measles cases were studied serologically under AFP surveillance system. RESULTS: The incidence was 1.36/100 000 in 1999. The incidence of children under 5 was 3.65/100 000, with 84.00% and 87.49% reduction, as compared with the incidence in 1991 and 1997 before intensified vaccination campaigns in children aged 1 - 6. The indicators of surveillance showed an improvement in 1999 than that in 1998. CONCLUSION: Training for health staff at county, township, vallage levels played an important role in improving the sensibility and timeliness of measles surveillance system. Routine immunization is a key element in curbing measles outbreaks and reducing measles incidence.

Adolescent↗

PubMed2001

[Fine mapping of the loss of heterozygosity for chromosome 1pter-p36.11 in nasopharyngeal carcinoma].

OBJECTIVE: To construct a detailed mapping of the Chromosome 1pter-p36.11 deleted region (63.4 cM) in nasopharyngeal carcinoma (NPC) by polymerase chain reaction-loss of heterozygosity (PCR-LOH) analysis for the further research of NPC-related gene(s). METHODS: Biopsies from 47 cases of NPC patients were studied. DNA extracted from separated cancer cells and their corresponding non-cancer lymphocytes were amplified with PCR, followed by the analysis of LOH and microsatellite instability (MI) for 20 loci spanning Chromosome 1pter-p36.11 region with an average interval of 3.0 cM. RESULTS: 82.2% of NPC cases (37/47) showed at least one loci of LOH. The highest frequency of LOH was found at loci D1S234 on 1p36.13 (50.0%), with the LOH at loci D1S2644 on 1p36.22 slightly less (37.5%). The occurrence of LOH at D1S234 showed no significant difference for the cases at early stage and at advanced stage [60% (9/15) vs 50.0% (8/16) respectively, P > 0.05]. High frequencies of MI were detected at D1S243 on 1p36.33 (37.5%) and D1S199 on 1p36.21 (30.2%). CONCLUSIONS: There are two common deletion regions: one localized at 1p36.13 (D1S234, 2.0 cM) and the other at 1p36.22 (D1S436-D1S2644, 6.3 cM), with a MI loci at D1S199 between them. This suggests that one or more putative tumor suppressor gene(s) related to the early stage of NPC tumorigenesis may be encompassed in this zone.

Adult↗

PubMed2001

[A study on the direct binding of LPS to endothelium and the characteristics of endothelial injury].

OBJECTIVE: To explore the characteristics of the combination of LPS to the endothelium and endothelial injury. METHODS: Myocardial microvascular endothelial cells (MMECs) were isolated and cultured to adhering state. Flow cytometry, laser confocal scanning microscope (LCSM) and image analysis were employed to evaluate the effects of different concentrations of LPS and different culturing time with the same concentration of LPS on the adhered MMECs RESULTS: (1) The OD values of MMECs increased progressively along with the prolongation of culturing time of MMECs with LPS and reached top level at 30 min. In addition, the increase of OD values was dependent on time. (2) The number of positive MMECs and the OD values increased after MMECs was cultured for 2 hours with LPS at concentrations ranging from 0.03125 similar 2.0000 g/L. The OD value reached peak level when LPS concentration was 0.2500 g/L, which implied that this concentration of LPS (0.25 g/L) was the optimal one for the combination of LPS with MMECs, and there was concentration saturation. (3) LPS could enter into the cytoplasm and nucleus of MMECs. (4) LPS could induce nucleic translocation and denucleation. CONCLUSION: (1) LPS could combine MMECs and enter into the nucleus without the presence of serum. (2) LPS could directly damage MMECs.

Animals↗

PubMed2001

[Frequency-specific responses of human brain to peripheral transcutaneous electric nerve stimulation: a functional magnetic resonance imaging study].

The purpose of the present investigation was to determine the responses of human brain to transcutaneous electric nerve stimulation (TENS) at different frequencies by functional magnetic resonance imaging (fMRI) examinations covering the whole brain of eleven healthy volunteers. Each subject received TENS at acupoints ST36 and SP6 of the left leg at the frequencies of 2 and 100 Hz. Frequency-specific responses were found in motor-related areas, thalamus, limbic system and associated cortex to stimulation of the two frequencies, while the primary somatosensory areas were activated by both. Therefore, it appears that 2 and 100 Hz TENS act through different neuro-pathways in the central nervous system.

Acupuncture↗

PubMed2001

[Clinical study on women with amenorrhea after levonorgestrel intrauterine system].

OBJECTIVE: To study the 5 years contraceptive efficacy of levonorgestrel intrauterine system (LNG-IUS) and the ovarian functions in amenorrhea women. METHODS: LNG-IUS and TCu 380A IUD were randomly inserted in 2 groups of women, 50 each. Women were followed annually for 5 years. Serum follicle stimulating hormone (FSH), luteinizing hormone (LH), prolactin (PRL), estradiol (E2), and T levels in 14 women with amenorrhea, and endometrial biopsies were obtained in 9 cases. RESULTS: By the end of 5 years, there were 2 pregnancies in TCu 380A group, but none in LNG-IUS group; and 24 amenorrhea cases in LNG-IUS. The 5 year cumulative continuation rates were 24% for LNG-IUS and 78% for TCu 380A (P < 0.001). In the 14 women with amenorrhea, the average serum concentrations were not significantly different from that of the normal controls. Histological study showed endometrial atrophy or a few secretory glands. CONCLUSIONS: LNG-IUS is a highly effective and safe contraceptive measure. Oligomenorrhea and amenorrhea caused by the local effects of LNG were reversible and did no harm to women's health. However, comprehensive consultation provided to women before insertion is of utmost importance for continuation use.

Adult↗