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Biomedical subjects

J Zheng

Publications and source records attributed to J Zheng.

At least 343 records · Page 19Linked to original sources
PubMed1997

[The inhibitory effect of antisense interleukin-6 on the growth of human lung carcinoma cells in vivo].

OBJECTIVE: Interleukin-6 (IL-6) has previously been implicated as a potential positive autocrine regulator of a human lung carcinoma cell lince PG. The purpose of the present study is to further evaluate the role of IL-6 in PG cells in vivo. METHODS: An antisense expression vector for IL-6 was constructed and introduced into PG cells. Antisense mRNA of IL-6 was detected by RNA-RNA dot blotting analysis. The production of bioactive IL-6 was measured by bioassay method. To determine the effect of antisense IL-6 cDNA on tumorigenicity, PG cells were inoculated subcutaneously into nude mice. RESULTS: Four transfectants, PGTAS1, PGTAS6, PGTAS8, PGTAS9, could express IL-6 antisense mRNA and secret decreased bioactive IL-6. The growth rate of 4 transfectants revealed was reduced in vitro. Comparing with the mice injected with the control PGTneo cells, the latent period of the mice inoculated with PGTAS6, PGTAS8, PGTAS9 cells was significantly increased, and the growth rate of the tumors was obviously decreased. The tumor size was markedly smaller. There was a negative correlation between the growth-inhibiting effect of IL-6 antisense gene and the amount of IL-6 secretion. CONCLUSION: These results indicate that IL-6 can function as an autocrine stimulator for PG cells in vivo as well as in vitro.

Animals↗
PubMed1997

[Effect of aerobic training on cardiac autonomic regulation revealed by heart rate variability analysis].

The aim of the present work is to elucidate the effect of aerobiac training on cardic autonomic function and to clarify whether there is any association between the changes in cardiac regulation and the heart rate dynamics and orthostatic tolerance during LBNP testing. To achieve this, the heart rate variability (HRV) signals obtained from a group of eight students before and after a 6-mon aerobic training, as well as from six athletes (medium- and long distance runners) were analyzed by conventional spectral, dynamic spectral and non-linear analysis. Our results showed that the conventional AR spectral analysis could not provide data with significance, owing to its greater variance and inherent limitation in being able to reflect only the average statistical characters over a certain period. While from the data obtained by use of the time-varying AR spectral analysis we could follow the time course of cardiac vagal withdrawl and sympathetic excitation during LBNP exposure. Regarding the non linear methods used, beta estimates didn't provide any significant result, but the ApEn analysis of the HRV signal could detect subtle changes in heart rate dynamics associated with aerobic training. Moreover, after aerobic training, the increments delta ApEn and delta DNP during LB NP testing were closely correlated. Our results would have important implications for further work in elucidating the effect of aerobic training on heart rate dynamics and improving the work on HRV signal analysis.

Adult↗
PubMed1997

[Diagnosis and management of piriform sinus fistulae in children].

In 12 patients with piriform sinus fistula, aged from 1.5 to 10 years all but one patient presented themslves with inflammatory swelling in the region of the left lobe of the thyroid gland. During acute infection, the involvement of the left thyroid lobe was verified by ultrasonography and scintigraphy. Barium swallow examination was the diagnostic finding that all the 11 patients had a left-sided fistula. One patient presented with a painless cyst in the left thyroid lobe. Six patients operated on 4 underwent fistulectomy. In patient the fistula was not found. In the patient who had a cyst in the thyroid lobe, fistulectomy and cystectomy were done. All these patients did well postoperatively without recurrence. Six other patients were followed up without operation with in 1-6 years. Five patients remained asymptomatic. One patient had 3 recurrences during a 2 years follow-up period. Piriform sinus fistula is the most common underlying abnormality in the patients with acute suppurative thyroiditis. A better understanding about this rare branchial anomaly is of clinical importance.

Branchial Region↗
PubMed1997

[Study on the effect of ofloxacin and tanshinone II A on human leukocyte chemotactic migration in vitro].

In order to verify the possible anti-inflammatory activity and their potency of ofloxacin and Tanshinone II a, the effects of different concentrations of ofloxacin, Tanshinone II a and hydrocortisone on human leukocyte migration in vitro were investigated employing agarose migration technique in which f-Met-Lea-Phe was served as chemotactic factor. The results showed that all the three agents could inhibit migration of leukocytes remarkably. The effects were concentration-dependent with excellent linear relationship. The IC50 were: Tanshinone II a 0.46 microgram/ml, ofloxacin 0.63 microgram/ml, and hydrocortisone 46.52 micrograms/ml respectively. The results indicated that Tanshinone II a was the most potent agent for inhibiting migration of human leukocytes in vitro and the hydrocortisone was relatively less potent.

Abietanes↗
PubMed1997

[Video image analysis of AgNORs distribution in the testicular tumor].

For the purpose of exploring the relationship between AgNORs and the biological behaviour of the testicular tumor, the value of enumeration and image analysis of AgNORs has been investigated in 10 normal testicular tissues and 49 cases of testicular tumors. The major findings were: AgNORs value for number, area, mean area, large partical number (LPN) and roundness in normal, benign and malignant tumors had significant difference (P < 0.01). The former four parameters turned larger when the tumor became more malignant, and they were significantly higher in the good prognosis group than in the bad one. LPN was higher in stage III than in stage I and II (P < 0.05), no difference was found between stage I and II. Other parameters had no significant difference in each stage. These results indicate that AgNORs is helpfull in differentiating the benign and malignant testicular tumors, in determining the degree of malignancy and offering an additional prognostic indicator in testicular tumors. Partical numbers, area and LPN were more helpfull. It had no important value in differenciating each stage.

Endodermal Sinus Tumor↗
PubMed1997

[Antioxidative effect of constituents of herba Epimedii (ESPS)].

Herba Epimedii is a traditional Yang invigorating Chinese herb widely used in clinic. The experimental results have shown that ESPS obviously increases superoxide dismutase(SOD) activity of red cells and liver in aged mice and rats, and increases glutathione peroxidase(GSH-Px) activity of red cells in aged mice. On the other hand, ESPS obviously helps to reduce the content of serum and liver lipoperoxide(LPO) in aged mice and rats, as well as the content of lipofuscin(LF) in cardiac muscle of aged mice. The results suggest that being helpful in increasing SOD and GSH-Px activities and inhibiting the formation of LPO and LF, ESPS may be a good antiageing agent.

Aging↗
PubMed1997

[Interleukin-6 functions as an autocrine growth stimulator for a human lung adenocarcinoma cell line PAa].

OBJECTIVE: To study the effect of interleukin-6(IL-6) on the growth of a human lung adenocarcinoma cell line PAa in vitro. METHODS: IL-6 receptor (IL-6R) mRNA level was detected by means of reverse transcription polymerase chain reaction (RT-PCR) and IL-6 mRNA was analyzed using Northern blotting hybridization. The production of IL-6 was detected by bioassay. The biological effect of IL-6 released by PAa cells was assessed with anti-IL-6 neutralizing antibodies. RESULTS: PAa cells expressed IL-6R mRNA. Recombinant human IL-6 stimulated the proliferation of PAa cells. PAa cells also expressed IL-6 mRNA and produced bioactive IL-6. Treatment of PAa cells with anti-IL-6 antibodies resulted in decreased growth of PAa cells. CONCLUSION: These results demonstrate that IL-6 acts as an autocrine growth stimulator for PAa cells in vitro.

Adenocarcinoma↗
PubMed1997

[Genistein suppresses growth stimulatory effect of growth factors in HCE 16/3 cells].

OBJECTIVE: The role of genistein in the effect of growth factors (KGF and EGF) on the growth of HPV 16 DNA-immortalized human cervical epithelial cells (HCE 16/3 cells) was studied. METHODS: Genistein affected the modulation effect of the growth factors on the growth of HCE 16/3 cells using [3H]-thymidine incorporation, immunocapture assay of uPA and tyrosine kinase assay. RESULTS: The growth factors stimulated growth of HCE 16/3 cells in serum-free medium. However, genistein suppressed the growth stimulatory effect of growth factors on HCE 16/3 cells and also reduced KGF-enhanced uPA secretion in this cell line. The inhibitory effects might be associated with its attenuation of activity of tyrosine kinases of growth factors. CONCLUSION: The results suggest that genistein have potential value in the prevention and treatment of some tumors in vivo.

Antineoplastic Agents↗
PubMed1997

[Measurement of minimal cross-sectional area of the nasal cavity and distance of minimal cross-section area from the nostril in healthy Chinese by acoustic rhinometry].

1,355 healthy Chinese, 3-86 years old, were measured with acoustic rhinometry. The range of normal value of minimal cross-sectional area (MCA) of the nasal cavity and distance of minimal cross-section area from the nostril (DCA) were obtained and the association of MCA and DCA with age in children and juvenile were discussed. The results showed that the range of MCA of unilateral nasal cavity was 0.192-0.915 cm2, DCA was 0.300-2.554 cm. The changes of MCA and DCA were highly associated with age in children and juvenile (P < 0.01). In adults, there was significant difference of MCA and DCA between different sexes in the different groups. It was demonstrated that these data could provide available information for the study of nasal physiology and pathophysiology, as well as for the diagnosis and judgement of therapeutic effectiveness of nasal diseases.

Acoustics↗
PubMed1997

[Possible significance of novel DNA fragments frequently deleted from tumor cell lines of human esophageal cancer].

OBJECTIVE: To disclose the genetic susceptibility and carcinogenesis mechanism of esophageal cancer (EC) through finding out tumor suppressor genes. METHODS: Twenty EC tissues paired with adjacent normal mucosa and three high-risk EC families were analysed by PCR and Southern blot with DNA probes (12H2, 33B2, and 33B3) frequently deleted from EC cell lines. RESULTS: In surgical samples, the deletion frequency of the fragment 12H2 was highest, i.e. 61% in EC tissues and 22% in adjacent mucosa. The rate of tumor metastasis to lymph nodes was 45%. For the fragment 33B2, they were 30%, 10% and 50%, respectively. But only 20%, 10% and 25% were of the fragment 33B3. No genetic changes were found in the three high-risk EC families for 12H2 and 33B3. The deletion of 33B2 was seen in the proband of one family. CONCLUSION: The fragments 12H2, 33B2 and 33B3 may be candidates of tumor suppressor genes correlative with progression and metastasis of esophageal cancer.

Adult↗
PubMed1997

[Laboratory study on pharmacology of Chinese medication qizhi weitong powder].

The Chinese medication Qizhi Weitong Powder has been proved very helpful in depressing gastric evacuation and small intestinal propel reducing gastric secretion, lowering acidity of gastric liquid and activity of pepsin as well as enhancing peristalsis of domestic rabbits. Other effects such as distinct protection to ligated ulcer of pylorus and painkilling have also been confirmed.

Animals↗
PubMed1997

[Purification and properties of inulinase from Kluyveromyces sp. Y-85].

The crude endocellular inulinase from Kluyveromyces sp. Y-85 was purified to two components, designated as EI and EII, using PEG6000-phosphate buffer extraction, (NH4)2SO4 fractionation, DEAE chromatography and gel filtration (Protein-PAK); The crude exocellular inulinase from this strain was purified to Eexo by means of PEG6000-phosphate buffer extraction, double DEAE-Sephace chromatography, Sephadex G-150 gel filtration. EI, EII and Eexo were demonstrated to be homogeneous by Waters 650E protein purification system. Their molecular weights are 42 kD, 65 kD and 57 kD, respectively. All the inulinases were glycoproteins containing a saccharide (from 25% to 35%) and belonged to the endo-inulinase. In addition, EI, EII, Eexo were optimally reactive at pH4.6, 4.5, 4.6 and at 52 degrees C, 52 degrees C, 55 degrees C, respectively. Ag+, Hg2+ and PCMB inhibited these enzymes' activity strongly. The products of raw inulin extracted from Helianthus tuberosus hydrolyzed by these three enzymes were fructose (86.5%) and glycose (13.5%).

English Abstract↗
PubMed1997

[Human lens epithelial cells culture in vitro].

PURPOSE: To provide a simple and rapid procedure to culture human len epithelial cells in vitro. METHODS: Specimens of capsule lentils were isolated from lens by microscissors. They were cut into small segments and then directly implanted into basks(culture bottles). The tissue pieces were cultured in a incubation at 37 degrees C with PR1640 until attached cells reached confluence. The len epithelium were passaged by tropism. RESULTS: Len epithelial cells usually appeared after 4 days in incubation. The cells growed rapidly in a way of attachments. CONCLUSION: Len epithelial cells were easily cultured with our method. The procedure is simple, rapid and highly successful.

Cell Culture Techniques↗
PubMed1997

[Approximate entropy analysis of changes in heart rate dynamics associated with aerobic training].

To elucidate the effects of aerobic training on heart rate dynamics, heart rate variability (HRV) of eight students before and after a six-month aerobic training and HRV of six athletes, were analyzed with conventional time and frequency domain methods as well as with the approximate entropy(ApEn). The results showed that after a six-month aerobic training, heart rate ApEn significantly decreased (P < 0.01, P < 0.05) during both supine control and -6.67 kPa/30 min lower body negative pressure (LBNP). The heart rate ApEn of the athletes during supine control and early stage of LBNP testing was significantly lower (P < 0.01, P < 0.05) than that of the students before training. It was found that the values of ApEn were negatively correlated with the duration of LBNP in the student group (P < 0.01). However, both the time and frequency domain analyses were unable to detect the aforementioned changes. The results suggest that aerobic training can decrease the complexity of heart rate dynamics, and the synchronization in heart rate control during LBNP is probably a sustained process.

Aerospace Medicine↗
PubMed1997

[Time-variant AR spectral method for non-stationary heart rate variability signal under gravitational stress].

In order to study the nonstationary heart rate variability (HRV) signals under gravitational stress, a time-variant autoregressive spectral estimation method has been implemented, which made it possible to study dynamically the process of cardiac autonomic regulation during various gravitational stresses. The HRV signals obtained from 8 subjects during seated-LBNP testing before and after a six-month aerobic training were analyzed by the implemented algorithm. The obtained time-variant spectra might clearly reveal the time course of changes of decrease in HFn and increase in LF/HF, reflecting the time course of cardiac vagal withdrawal and indices with time during seated-LBNP were increased in most of the subjects. In brief, our work shows that the method of time-variant AR spectrum analysis for non-stationary HRV signals makes it possible to elucidate the dynamics of cardiac autonomic regulatory activity under gravitational stress and to detect the subtle changes in HRV after aerobic training.

Arrhythmias, Cardiac↗
PubMed1997

Change in heart rate dynamics after aerobic training detected by approximate entropy and its association with orthostasis.

Findings from the 1973 Skylab mission and early studies led to the conclusion that high level of aerobic capacity might be detrimental to the orthostatic tolerance of returning astronauts. Numerous studies have addressed the problem with conflicting results, further work is needed to establish the relationship between aerobic capacity and orthostasis. During the last two decades, the technique for heart rate variability (HRV) signal analysis developed and have provided a non-invasive probe to examine quantitatively changes in cardiac autonomic balance. In the past, spectral analysis has been used in these studies. During the early 90's, a new mathematical approach and formula termed approximate entropy(ApEn) has been introduced as quantification of regularity and complexity. More recently, ApEn has been used to quantitate the loss of normal nonlinear heart rate variability in a variety of pathological conditions, aging, as well as bed rest deconditioning. The present study was undertaken to assess the effect aerobic training on orthostatic tolerance and HRV analyzed by both conventional AR spectral and ApEn analysis.

Adult↗