Biomedical subjects

R Zhang

Publications and source records attributed to R Zhang.

At least 289 records · Page 16Linked to original sources

PubMed1998

[The study on in vitro antibody secretion of B lymphocyte in patient with pregnancy induced hypertension].

OBJECTIVE: To study the immunologic etiopathology of pregnancy induced hypertention (PIH) in some extent by analyzing the antibody secretion of B lymphocytes of PIH patients. METHODS: The subjects were divided into two groups: PIH group (n = 15) and normotensive control group (n = 15). Peripheral lymphocytes of the subjucts were separated by Ficoll-Hypaque density centrifugation. The lymphocytes were cultured in RPMI-1640 medium with or without pokeweed mitogen (PWM) for ten days. Then the supernatant was collected and the IgG and IgM were measured by enzyme linked immunosorbent assay (ELISA). The results of the two groups were analyzed by using student test. RESULTS: Both IgG and IgM secretion of B lymphocytes between PIH group and normtensive control group showed no difference in the absence of PWM (per 1 x 10(6) lymphocytes, for IgG, 120 +/- 68 ng vs 154 +/- 89 ng, P > 0.05; for IgM, 337 +/- 119 ng vs 371 +/- 135 ng, P > 0.05. Whereas the level of the two antibodies in PIH group was significantly decreased than that of the normotensive group in presence of PWM (for IgG, 947 +/- 518 ng vs 1,367 +/- 598 ng, P < 0.05; for IgM, 2,023 +/- 879 ng vs 2,840 +/- 1,057 ng, P < 0.05). CONCLUSION: B lymphocyte of PIH patient has a decreased capacity of antibodies secreting in response to stimulation of PWM, which suggests that B lymphocyte of PIH patient may have functional deficiency.

Adult↗

PubMed1998

[The effect of enzyme-linked immunosorbant assay and polymerase chain reaction on the detection of maternal and fetal human cytomegalovirus infection].

OBJECTIVE: To evaluate polymerase chain reaction (PCR) and enzyme-linked immunosorbant assay (ELISA) on detection human cytomegalovirus (HCMV) infection in preghnant women and fetuses. METHODS: ELISA was used to screen for serum HCMV-IgM in 1881 pregnant women. Blood HCMV DNA was examined by PCR in 656 of them simultaneously. 99 fetuses or newborns of HCMV infected mothers and 47 of uninfected ones were detected by both methods. RESULTS: The positive rate of serum HCMV-IgM in pregnant women was 2.4%, and that of HCMV DNA was 12.0%, 17.2% of fetuses or newborns from infected mothers had either positive HCMV-IgM or positive HCMV DNA or both of them. The intrauterine transmission rate of HCMV in mothers with positive HCMV-IgM or positive HCMV DNA or both of them was 18.5%, 14.8% and 27.3% respectively. Simultaneous detection with ELISA and PCR in 656 pregnant women and 146 fetuses showed fine correlations and significant differences between two methods. PCR had significantly higher detection rates than that of ELISA. CONCLUSIONS: ELISA combined with PCR may raise the detection rate and diagnostic efficacy of HCMV infection in both pregnant women and fetuses.

Adolescent↗

PubMed1998

[Surgical treatment results for carcinoma of the gastric cardia in 1832 cases].

OBJECTIVE: To evaluate the results of surgical treatment for carcinoma of the gastric cardia and the prognostic factors. METHODS: The prognostic factors were assessed with 5-year survival rates which was estimated using life table method in 1832 cases. The difference between groups was assessed by the log rank test. RESULTS: The overall resection rate was 76.3% and the radical resection rate 53.4%. The overall 5-year survival rate was 23.5% while in patients treated with curative resection it was 29.9%. The 5-year survival rate was 29.4% in patients received preoperative radiation and 21.5% in patients treated with surgery alone (P > 0.05). Patients whose upper margin of resection was longer than 5 cm away from the tumor had higher 5-year survival rate (25.8%) than those with margin of resection less than 5 cm (18.4%). The difference was statistically significant (P < 0.05). CONCLUSION: Preoperative radiation can increase the survival rate, but it was not statistically significant. Increasing the margin of resection to > 5 cm can improve survival.

Adenocarcinoma↗

PubMed1998

[Treatment of malignant germ cell tumors of the ovary: a clinical analysis of 233 cases].

OBJECTIVE: To evaluate the treatment methods of malignant germ cell tumors of the ovary. METHODS: Two hundred thirty three patients with malignant germ cell tumors of the ovary treated during 1958 through 1993 were retrospectively analyzed. The number of patients in different stage of the disease was as follows: stage I, 94; stage II-IV, 43; recurrence or metastasis, 96. Unilateral salpingo-oophorectomy was performed in 78 patients, or total abdominal hysterectomy and bilateral salpingo-oophorectomy with or without omentectomy and appendectomy was performed in 151 cases, and biopsy in 4 cases. Operation alone was done in 17 cases, operation plus radiotherapy with or without chemotherapy in 65, operation plus chemotherapy in 151 cases. RESULTS: Of the 233 patients 127 were disease-free. The number of survivors in stage I patients was 78, in stage II-IV was 17. There were 32 cases with recurrence and metastasis. The overall 5-year survival rate was 55.6%. The 5-year survival rate differed between dysgerminoma and nondysgerminomatous tumurs being 84.2% for the former and 44.6% for the latter. In patients with nondysgerminomatous tumors, chemotherapy with PVB and BEP regimens gave a 5-year survival rate of 66.0% and 73.3%, respectively. CONCLUSION: Malignant germ cell tumors of the ovary is very sensitive to chemotherapy. The PVB and BEP regimens result in excellent response in these patients. Complete remission and preservation of fertility can be obtained in patients with early tumors. Preoperative chemotherapy and postoperative adjuvant chemotherapy can improve survival in patients with advanced tumors.

Adolescent↗

PubMed1998

[Primary esophageal adenocarcinoma].

OBJECTIVE: To study the clinical biocharacteristics of primary esophageal adenocarcinoma (PEAC) and factors influencing patients' prognosis and to find reasonable surgical indications and combined therapy. METHODS: To analyse the clinical materials of 106 patients with PEAC undergone operation compared with those of patients with esophageal squamous-cell carcinoma (ESCC). RESULTS: The overall resectability, morbidity and 30-day mortality rate of PEAC was 92.5%, 23.5% and 2.8% respectively, similar to those of ESCC. The TNM staging, lymph node metastasis, extraesophageal invasion and types of operation were the major determinants influencing long-term prognosis. The 5-year survival rate of PEAC was 21.0%, which was lower than that of ESCC(P < 0.01). Metastasis or recurrence remained to be the cause of death in 82.4% of patients who lived longer than 5 years, which was higher than that of ESCC(P < 0.01). Adjuvant radiation did not influence survival of the patients with lymph node metastasis, but appeared helpful to the patients with no lymph node metastasis. CONCLUSION: Compared with ESCC, PEAC is a malignent disease with poor prognosis. Surgical resection is the first and chief choice of treatment. Surgical indications include patients in stage 0, I, II and some in stage III and even in stage IV of PEAC. Early diagnosis and early treatment as well as curative operation could improve prognosis. Adjuvant radiation therapy appeares helpful only to the patients without lymph node metastasis.

Adenocarcinoma↗

PubMed1998

[Extent and mode of metastatic spread to lymph nodes in patients with adenocarcinoma of the gastric cardia: a multivariate analysis using COX proportion hazard model].

OBJECTIVE: To investigate lymph node metastases (LNM) and assess LNM level accurately after standard resection. METHODS: An analysis was done in 736 patients with resected gastric cardia cancer whose postoperative survival time was longer than three months, through comparison of prognosis, frequency of LNM and ratio of the number of invaded to removed lymph nodes (I/R), using COX multivariate analysis model. RESULTS: (1) The most important prognostic variables were I/R, left gastric artery LNM, lesser curvature LNM, and paracardia LNM. (2) The patients without LNM had better survival (P < 0.001). (3) There were a relatively regular way of LNM and significant difference between LNM of single site and that of multiple sites on the frequency of LNM and I/R, respectively (P < 0.05). (4) There was significantly different I/R among group 1 (single paracardia LNM and single lesser curvature LNM), group 2 (single left gastric artery LNM and paracardia plus lesser curvature LNM) and group 3 (multiple sites in association with left gastric artery LNM) (P < 0.05). CONCLUSION: The dissemination of LNM seems to be as follows: from paracardia lymph nodes to distant lymph nodes, and from a single lymph node of one site to multiple sites with many lymph notes involved. It is suggested that group 1 LNM belongs to station 1, group 2 LNM to station 2 and group 3 LNM to station 3 according to their I/R.

Adenocarcinoma↗

PubMed1998

[An improved method of cholesterol determination in egg yolk by high performance liquid chromatography].

An improved method for cholesterol determination in egg yolk is reported in this paper. Egg yolk was first diluted. Cholesterol was then extracted with ethyl ether and petroleum ether, and quantified by reversed phase liquid chromatography on a Zorbax ODS column (0.46 mm x 15 cm, 5-6 microns) using a mobile phase of acetonitrile and 2-propanol (4:1) with a flow rate of 0.6 mL/min. A linear correlation was observed between 0.05-0.40 g/L of cholesterol. The determination limit was 0.02 g/L. This proposed method of HPLC determination of egg yolk without saponification is superior to colorimetric determination on the sample with saponification, and comparable to HPLC determination with saponification of the egg yolk sample in terms of reliability. No difference in final results was observed between egg yolk sample with saponification and the same sample without saponification. Rapid and reproducible quantification of cholesterol in egg yolk can be completed with this new method. Omission of saponification has made this proposed method more convenient than those ever reported, and can be used in yolk cholesterol study with greater ease.

Cholesterol↗

PubMed1998

[E2-induced prolactin-secreting tumor of heteroplasty pituitary in renal capsule of the rats].

OBJECTIVE: A prolactin-producing tumor induced by 17-beta-estradiol (E2) in isotransplanted pituitaries under renal capsules of SD rats were studied. METHODS: Male SD rats (30 days old) were transplanted with an isologaus pituitary under renal capsule and treated with subcutaneous implantation of an empty or E2-laden silastic capsule. RESULTS: After treated with E2 for 60 days and 120 days, both the eutopic and ectopic pituitaries were more than three times heavier than those from control rats, accompanied by hyperprolactinemia, and the body weight of rats decreased significantly. The effects of E2 on the weight of eutopic pituitary and the concentration of plasma PRL were time-dependent. In situ hybridization was employed to measure the levels of PRL mRNA expression in cells from the eutopic and ectopic pituitaries 120 days after treatment of E2. The PRL mRNA contents in both the eutopic and ectopic pituitary cells were much greater than those in untreated pituitary cells. But PRL mRNA levels showed no significant difference between the eutopic and ectopic pituitary cells. CONCLUSIONS: Our previous data has shown that prolactinomas can be induced by chronic treatment of E2 in eutopic pituitaries of SD rats. In present study it appeared that E2 exerted similar effect on the ectopic pituitaries which were distant from the hypothalamus. Our results also demonstrated that E2 could promote the PRL gene expression in both the eutopic and ectopic pituitary cells, and there was no significant difference between them. Our data suggested the possibility of PRL-producing pituitary tumors could originate from anterior pituitary.

Animals↗

PubMed1998

[Assessment of responsiveness of spontaneous baroreceptor-heart rate reflex under gravitational stress].

Beat by beat arterial blood pressure was measured using Finapres 2300 monitor. Sequences of 3 or more beats with systolic pressure and next beat interval changed in the same direction were identified as baroreflex sequences from 6-min data segments. A linear regression was applied to each sequence and the slope (correlation coefficient > or = 0.85) was taken as a measure of the baroreflex response slope (BRS). The changes in mean BRS during + 65 degrees head-up tilt (HUT), -6.67 kPa lower body negative pressure (LBNP) and 16 days -6 degrees head-down tilt (HDT) bed rest were observed. The results showed that there was a significant decrease in the mean BRS during LBNP or HUT as compared with that of the supine control, though the blood pressure responses differed. The mean BRS was also significantly decreased during bed rest. It suggests that the responsiveness of spontaneous baroreceptor-heart rate reflex can be evaluated in humans under gravitational stress.

Adaptation, Physiological↗

PubMed1998

[Possibility of adopting hypoxic environment in the cabin for manned space flight].

The favourable and the unfavourable factors of normal baric hypoxia (1.0 atm, oxygen concentration below 21%) and hypobartic hypoxia (cabin pressure below 1.0 atm, 21% O2) in the cabin for manned space flight were discussed. Author considered that proper hypobaric hypoxia in the cabin (0.8-0.9 atm, 21% O2) would be benifit no matter for long or short term space flight. For long term space flight, the microclimate control model in the cabin should be considered again, it controlled in a narrow comfortable zone would unfavourable to human adaptability to changing environment. All these problems proposed in this paper need to be further studied.

Air Conditioning↗

PubMed1998

[Primary ileocecal lymphoma: report of 30 cases].

OBJECTIVE: To investigate the best therapeutic method for primary ileocecal non-Hodgkin's lymphoma. METHOD: Clinicopathologic features of 30 patients who had been treated from June 1964 to September 1993 were analyzed retrospectively. RESULT: Twenty-eight patients (93%) underwent resection of their disease. Eleven patients had the resection followed by chemotherapy. Eleven patients had the resection followed by chemotherapy and radiotherapy. All had pathologic evidence. Twenty-nine patients were categorized as B-cell type NHL. One had T-cell lesion. Eleven patients had stage I disease, 11 stage II, 4 stage III, and 4 stage IV. The 5-year survival rate was 36.67%. CONCLUSION: The prognostic factors are stage of the disease and treatment modality. Adequate initial surgery combined with radiotherapy and chemotherapy may provide optimum therapy for patients with primary ileocecal lymphoma.

Adolescent↗

PubMed1998

[A new saikosaponin from Bupleurum Chinese DC].

Bupleurum chinese DC. is a well-known and very important traditional Chinese drug. It is often used to treat common cold with fever, alternating chill and fever, the feeling of fullness and oppression in the chest. A new saikosaponin was isolated from Bupleurum chinese DC. and its structure was identified as 3 beta, 16 beta, 28-trihydroxy-11-alpha-methoxy-olean-12-ene-3-O-beta-D-glucosyl-(1-->3)-beta D-fucoside on the basis of chemical and spectral evidence. In addition, six known saikosaponins were isolated and characterized as saikosaponin a, saikosaponin d, saikosaponin c, saikosaponin f, saikosaponin b3 and saikosaponin b2. All these compounds were isolated from Bupleurum chinese DC. for the first time.

Bupleurum↗

PubMed1998

[A new saikosaponin from Bupleurum chinense DC].

Bupleurum chinense DC. is a well-known and very important traditional Chinese drug. It is often used to treat common cold with fever, alternating chill and fever, feeling of fullness and oppression in the chest. A new saikosaponin was isolated from Bupleurum chinense DC. and its structure was identified as 3-O-[beta-D-glucopyranosyl (1-->3)-beta-D-fucopyranosyl]-3 beta, 16 alpha, 23, 28-tetrahydroxy-olean-11, 13 (18)-dien-30-oic acid 30-O-[xylityl(1-->1)]-beta-D-glucopyranosyl-6-ester on the basis of chemical and spectral evidence. In addition, three known saikosaponins were isolated and characterized as saikosaponin 1, 2"-O-acetyl-saikosaponin b2 and 2"-O-acetyl-saikosaponin a. All the compounds were isolated from Bupleurum chinense DC. for the first time.

Bupleurum↗

PubMed1998

[Research and development of the surface EMG detection and analysis system].

To meet the requirement of developing myoelectric controller for a man-machine systems, a surface electromyography (EMG) detection and analysis system is discussed in this paper. This system consists of two parts--data acquisition hardware and signal processing software. In the surface EMG acquisition system both wire and wireless TELEMG are available. In the surface EMG processing system various methods are integrated such as the methods in time domain, the methods for frequency analysis, and also including some newly developed methods, e.g., wavelet transform and fractal analysis. This system provides a useful platform for research and development of the myoelectric controller that is widely used in rehabilitation engineering products.

Electromyography↗

PubMed1998

[Determination of levofloxacin in plasma and cerebrospinal fluid with HPLC and its pharmacokinetics in patients undergoing neurosurgical operations].

A RP-HPLC method was developed to determine the concentrations of levofloxacin in plasma and cerebrospinal fluid and its pharmacokinetics were studied in patients undergoing neurosurgical operations. C18H37 column was eluted with the mobile phase consisting of 10 mmol.L-1 KH2PO4-10 mmol.L-1(C4H9)4Br-CH3CN(45:45:10, pH 3.0) and the utraviolet absorbance was monitored at 295 nm. Ciprofloxacin was used as internal standard. The mean recoveries were 74.76% in plasma and 82.43% in cerebrospinal fluid, with the lowest detectable limits of 10 micrograms.L-1 and 6 micrograms.L-1, respectively. The RSD for the intra-day and inter-day were all less than 5%. A single oral administration of 300 mg levofloxacin tablet was given to 10 patients undergoing neurosurgical operations. The pharmacokinetic parameters in blood and in cerebrospinal fluid could be described by one compartment open model. The pharmacokinetic parameters were: blood Ke 0.12 +/- 0.04 h-1, T1/2 6.05 +/- 1.68 h, Tmax 1.05 +/- 0.29 h, Cmax 3.67 +/- 0.42 mg.L-1, AUC 33.43 +/- 7.32 mg.h.L-1, CLs 9.46 +/- 2.53 L.h-1, Vd 77.49 +/- 7.39 L; cerebrospinal fluid Ke 0.11 +/- 0.04 h-1, T1/2 6.95 +/- 1.88 h, Tmax 3.56 +/- 1.24 h, Cmax 1.68 +/- 0.25 mg.L-1, AUC 23.70 +/- 5.62 mg.h.L-1, CLs 13.70 +/- 5.11 L.h-1, Vd 126.61 +/- 13.20 L.

Adult↗

PubMed1998

[The role of village doctors and their influence factors in malaria control].

AIM: To consolidate the acquired achievements of malaria control and to work out an effective programme for training the village doctors in Yibin District. METHODS: A stratified sampling was done at random with sampling 27 village medical stations and 67 village doctors from 9 townships of 3 counties. A questionnaire concerning malaria control knowledge of the village doctors and the quality of their carrying out antimalaria measures was used in this study. RESULTS: The accuracy rate of answering the questionnaire among the village doctors was 79.3%, being higher in the village doctors receiving antimalaria training than in those not receiving antimalaria training. 82.5% of the doctors could correctly complete the tasks of controlling malaria. In addition, the quality of malaria control implementing in areas where the doctors and their stations had timely got investment funds, preferential policy, system of reward and subsidy from local governments, was superior to those areas where the doctors and their stations had not received those on time. 91.9% of the trained doctors completed the tasks of controlling malaria better than untrained ones. CONCLUSION: Greater efforts should be made to give a systematic training to village doctors on the knowledge and technique of malaria control, and to strengthen management and support in order to help these doctors accomplishing the tasks of malaria control better.

Community Health Workers↗

PubMed1998

[Construction and identification of recombinant fowlpox virus for expressing haemagglutinin-neuraminidase glycoprotein of Newcastle disease virus strain F48E8].

For the construction of transfer vector pFGHN1175-1, the gene encoding haemagglutinin-neuraminidase(HN) glycoprotein of newcastle disease virus(NDV) strain F48E8 was removed from plasmid pGEMHN, and inserted into the HindIII site of insertion vector pFG1175-1, downstream of P7.5 promotor. Chicken embryo fibroblast (CEF) cell cultures which had been infected with fowlpox virus (FPV) Chinese vaccine strain 282E4 for 3-4 hours were transfected with pFGHN1175-1 plasmid DNA by liposomal transfection. Recombinant FPV with blue plaques were selected and purified 3 times in CEF cell cultures overlaid agarose containing X-gal. PCR analysis and DNA dot-blotting hybridization assay indicated that the HN gene had inserted into the FPV genomic DNA. The expression of the NDV HN gene in recombinant FPV was confirmed by indirect immunofluorescence assay with specific monoclonal antibody.

Animals↗

PubMed1998

[Design and experimental study of an opening type implantable artificial pancreas equipped with a pulse pump and a micropore slow delivery pump].

According to physiologic character of insulin secretion of normal body, one new design has been advanced. It can provide insulin with both pulsed and slow-released ways, and imitate separately two completely different forms of insulin secretion. Through extracorpored experiment, one parallel model has been set up. One function is similar to post-cibum largely and quickly pulsed insulin secretion, other one is continuous and stable micro-secretion in 24 hours. The theoretical base for researching furtherly the open implanted artificial pancreas (pump) depends on the result of this article.

Equipment Design↗