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Biomedical subjects

Z Chen

Publications and source records attributed to Z Chen.

At least 847 records · Page 47Linked to original sources
PubMed1998

[Multiple-layer composite rhytidectomy].

OBJECTIVE: The multiple-layer composite rhytidectomy is presented in this paper for correction of the facial aging. METHODS: The operative procedures include multiple-layer dissection, suspension reconstruction of the zygomatic ligament, and thinning of the zygoma. RESULTS: The method has produced a good result in 28 patients since 1993. CONCLUSION: Study of clinical cases and cadaver dissections had led to better understanding of the aging face. With advancing age, all tissues of the face lose their balanced relationship. These changes occur in their volume shape, position, and consistency. With the multiple-layer dissection and suspension, the soft tissues of the check, forehead, nasolabial fold, lateral canthus and eyebrow can be lifted to reestablish their previously youthful relationship with the underlying skeleton.

Aged↗
PubMed1998

[Correction of nasal septal deformities of the unilateral cleft lip].

OBJECTIVE: Septal deformities are very common in patients with unilateral cleft lip nose. The deformities are influential on the morphology of the external nose and respiratory function. The study was conducted to correct the septal deformities. METHOD: The operation procedure includes correction and replacement of the deviated septum to the middle position; correction of the displaced alar cartilage with the suspension method and correction of soft tissue deformities of the nose and lip. Twelve patients were treated with this method from 1994 to 1995. RESULT: Postoperative follow-up of 3-12 months demonstrated satisfactory results. CONCLUSION: Correction of septal deformities plays a very important role in the operation for the unilateral cleft lip nose.

Abnormalities, Multiple↗
PubMed1998

[Expression of telomerase in acute leukemia].

To understand the expression patterns of telomerase activity in different types of acute leukemia(AL) and during remission state, the mono-nuclear cells of different bone marrow samples were isolated by desity gradient centrifugation. Telomerase activity of the samples was assayed by telomeric repeat amplification protocol(TRAP) with the cell extracts and the TRAP products were resolved in PAGE. The results showed that the telomerase activity was at higher levels in the acute leukemia compared with the normal controls. Of the acute nonlymphocytic leukemia(ANLL), the telomerase activity presented as M2a > M5b > M1 > M3b. Of the acute lymphocytic leukemia(ALL), the activity presented as L1 > L2. The activity assayed in M2a and L2 remission was as high as that in the normal group. It indicated that the expression of telomerase was enhanced differently among the subtypes of ANLL and ALL, and was down-regulated during the AL remission. It implicates that the expression patterns of telomerase activity in AL is associated with the different proliferation states and differentiation properties of the AL cells.

Adolescent↗
PubMed1998

[Study on the effects of hyaluronic acid-streptomycin perfusion through the round window on the function and morphology in guinea pig inner ears].

To investigate the effects of the hyaluronic acid-streptomycin (HA-SM) perfusion through round window on the function and morphology of the inner ear in guinea pig, membrous labyrinth mapping, temporal bone section after celloidin embedding, transmission electron microscopy, electrocochlegraphy (ECochG) and electronystagmography (ENG) were examined. The nystagmus duration induced by caloric test was obviously reduced in comparison with that of the preoperation (P< 0.01), while the action potential(AP) by ECochG was not obviously changed. The sensory cells of estibular organs were severely damaged, while the morphology of corti's organs were significantly damaged after HA-SM perfusion. The results suggest that the HA-SM perfusion through the round window may selectively destroy the vestibular function, whereas the auditory function is not obviously damaged.

Animals↗
PubMed1998

[Study of a new type of material substituted for human hard tissues-hydroxyl poly calcium sodium phosphate: histologic report implants in mandible of animals].

This study was aimed to evaluate the histocompatibility of hydroxyl poly calcium sodium phosphate (HPPA) preliminarily. HPPA and hydroxylapatite were implanted in the mandibular defect in dogs. The implant-bone interface was observed by using stereomicroscope and decalcified histologic sections. The result demonstrates that HPPA has well-osseous integrated property after being implanted into bone tissues. This suggests that HPPA might be a new material of future excellence in substitution for human hard tissues.

Animals↗
PubMed1998

[Simultaneous assay of Ca(2+)-ATPase and Na+, K(+)-ATPase activities of osteoblast rat by malachite green colorimetic method].

The aim of this study was to find a method to measure simultaneously the activities of Ca(2+)-ATPase and Na+, K(+)-ATPase of rat osteoblast membrane. In this test, Ca(2+)-ATPase and Na+, K(+)-ATPase released inorganic phosphate (Pi) from ATP, and Pi was determined by colorimetric method using malachite green dye to show ATPase activities. Ca2+ concentration and osteoblast culture generation were important factors affecting ATPase activities. Ca2+ could elevate membrane ATPase activity. When Ca2+ concentration reached 40 mumol/L, ATPase activities were improved. Ca(2+)-ATPase activity decreased with the increase of osteoblast culture generation. Ca(2+)-ATPase activity was lower than Na+, K(+)-ATPase activity in osteoblast membrane. This method is simple, sensitive and reliable.

Animals↗
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 source of endogenous digitalis-like substance in normal pregnancy].

OBJECTIVE: To study the source of endogenous digitialis-like substance (EDLS) which increases in maternal vein plasma during normal pregnancy. METHODS: The EDLS concentrations in following samples: (1) villi in the 1st trimester (2) placenta, amnion and umbilical jelly of Wharton in the 3rd trimester, (3) plasma of normal non-pregnant women (4) maternal plasma in three trimesters, 24-48 hours post partum, (5) maternal plasma and umbilical blood in labour, were determined by radioimmunoassay. RESULTS: The concentration of EDLS in villi, placenta, amnion and jelly of Wharton was about 37, 33, 29 and 24 times higher respectively than the concentration of maternal blood. There was a significant positive correlation between the concentrations of EDLS in placenta or amnion and that in jelly of Wharton. Plasma EDLS levels in pregnant women of 1st and 2nd trimesters were similar to that in non-pregnant women, while in the 3rd trimester of pregnany they were significantly increased, and then significantly decreased in 24 to 48 hours post partum. There was a significant positive correlation between the plasma EDLS level and mean arterial pressure in the 3rd trimester. The EDLS concentration in plasma of umbilical vein and artery was about 3.1 and 2.9 times higher respectively than that in the maternal plasma. There were significant positive correlations between plasma EDLS levels of umbilical vein, artery or maternal vein and the weight of placenta or newborn. CONCLUSION: The fetal-placenta unit is the source of EDLS which increases in maternal vein plasma during normal pregnancy.

Adult↗
PubMed1998

[Chemosensitivity test for 170 human breast carcinoma samples].

We tested the in vitro sensitivity of 170 primary breast carcinoma samples to the anti-cancer drugs conventionally used in clinical chemotherapy. It was found that: 1. The high sensitivity rate (HSR) of breast carcinoma cells to 5-fluorouracil (5-Fu), mitomycin (MMC), cisplatin (DDP), adriamycin(ADM), methotrexate(MTX), vincristin(VCR), vepesid(VP-16), taxol, and vindesine(VDS) were 57.1%, 49.4%, 48.3%, 35.8%, 21.8%, 21.2%, 10%, 18.2% and 20.9%, respectively. The increase of HSR of cancer cells to 5-Fu, MMC, DDP, taxol was more significant than that of the other drugs tested (P < 0.05). 2. No correlation was shown between drug sensitivity and factors, i.e. pathological type, clinical type, expression of estrogen receptor (ER) and epithelium growth factor receptor(EGFR) for breast carcinoma (P > 0.05). 3. Cyclosporin A can increase part of the sensitivity of ADM-resistant breast carcinoma cells to ADM.

Adenocarcinoma↗
PubMed1998

[Immunoradiometric assay of tumor marker CA15-3 and its clinical application].

OBJECTIVE: To develop a new tumor marker immunoradiometric assay and to evaluate its preliminary clinical application. METHODS: With monoclonal antibodies Ma552 and Ma695 from Sweden, a sandwich immunoradiometric assay was developed with Ma552 as catching antibody and Ma695 as tracer. The Ma552 was coated on polystyrene beads, and Ma695 was labeled with 125-I. The reaction was one step at room temperature. RESULTS: Bmax/B0 of the standard curve was 82. The sensitivity of this assay was 0.3 u/ml, CV within assay and CV between assays were 8% and 10%, respectively. Serum level of CA 15-3 in 50 normal women was 11.3 +/- 3.9 u/ml with a false positive rate of 0% based on the cut-off value of 30 U/ml. In 40 patients with benign breast diseases the serum level was 9.6 +/- 5.8 u/ml with a false positive rate of 0%. In 65 cases of breast cancers in different stages it was 88.4 +/- 159.6 u/ml before treatments with a total positive detection rate of 50.8%. Metastases, especially, bone metastases caused significant serum CA15-3 elevation, with 100% positive rate(n = 9). The positive rate of recurrences of beast cancers was 80% (n = 5). CONCLUSION: The newly established immunoradiometric assay of CA15-3 is highly useful in the diagnosis, differential diagnosis, and monitoring of metastases and recurrences of breast cancer, and is superior to CEA.

Antigens, Neoplasm↗
PubMed1998

[Efficient gene transfer mediated by retrovirus vector in leukemic cells].

OBJECTIVE: To establish an efficient and safe gene transfer system mediated by retrovirus for providing an experimental basis of gene therapy in human leukemia. METHODS: The retrovirus vector pLXSN, carrying the NeoR, was transferred into amphotropic packaging cell line GP + envAm12 by liposome method or by transduction. Retrovirus with higher titer was used to infect human leukemic cell lines NB4, U937 and THP-1. The efficiency of gene transduction was tesed on colonies formed by K562 cells after gene transduction. RESULTS: The titer of DOSPER liposome transfected GP + envAm12 pool on NIH3T3 cells was 8.0 x 10(5) CFU/ml while that of producer pool infected with mouse retrovirus was 1.6 x 10(7) CFU/ml. Integration of NeoR into human leukemic cells was confirmed by PCR. By both nested PCR and NeoR rescue assay, no helper virus was found. NeoR gene transfer with the efficiency as high as 93.3 to 100% in K562 cells was verified by semi-nested PCR on the colonies after seven days' culture. CONCLUSION: The efficiency and safety of the gene transfer system may provide an optimal experimental system in gene therapy for human leukemia.

Animals↗
PubMed1998

[Expression of signal-regulatory protein alpha (SIRP alpha) in hepatocellular carcinoma].

OBJECTIVE: To investigate the association between signal-regulatory protein alpha (SIRP alpha) and hepatocellular carcinoma (HCC). METHODS: Thirty-six pairs of HCC and the surrounding noncancerous hepatic tissues, one normal liver cell line and 4 HCC cell lines were used to extract the total RNA and then to prepare the mRNA. The expression of SIRP alpha was determined by Northern blot analysis. The results were analyzed in association with the pathologic characteristics of each sample. RESULTS: SIRP alpha expressed at low level in 20 of 36 HCC samples and 2 of 4 HCC cell lines. Of the two major hybridization signals, a 3.9 kb transcript in HCC samples was 2-4 times lower than that in the surrounding noncancerous hepatic tissues, whereas a 2.5 kb transcript was 4-6 times as low. Furthermore, a hybridization signal slightly longer than 3.9 kb, being absent in the surrounding noncancerous hepatic tissue, appeared in 9 of the 20 HCC samples. Low level expression of SIRP alpha was observed in all of the 5 HCC samples that had intrahepatic or portal metastasis. CONCLUSION: The expression of SIRP alpha, especially 2.5 kb transcript, was down-regulated in HCC, and an unknown mumber or a variant of SIRP family existed in some tumor tissues. SIRP alpha protein may play an important role in hepatic oncogenesis and metastasis of HCC.

Antigens, Differentiation↗
PubMed1998

[Expression and significance of interleukin 6, interleukin 8 and their receptors in acute promyelocytic leukemia during all-trans retinoic acid induction treatment].

OBJECTIVE: To evaluate the expression and clinical significance of interleukin 6, soluble glycoprotein 130 (sgp 130), interleukin 8 and type A interleukin 8 receptor (IL-8RA) in acute promyelocytic leukemia (APL) patients during all-trans retinoic acid (ATRA) treatment. METHODS: Serum and bone marrow mononuclear cell (MNC) culture supernatant IL-6, sgp 130, IL-8 concentrations of 18 cases APL patients were measured (ELISA). Bone marrow MNC IL-8RA was measured by flow cytometry after cultured with ATRA (10(-6) mmol/L). RESULTS: Serum IL-6, sgp130, IL-8 levels were higher than normal (P < 0.05), IL-6, sgp130 levels correlated with white blood cell (WBC) counts (P < 0.05) while IL-8 level correlated with body temperature (P < 0.05) at initial diagnosis after 72-hour incubation with ATRA, concentration of IL-6 of bone marrow MNC culture supenatant did not change, that of sgp130 mildly decreased, and IL-8 significantly decreased while the positive rate of IL-8RA on bone marrow MNC increased. During ATRA treatment, serum IL-6 changes were correlated with WBC changes. Peak level of IL-6 and WBC was lower in patients received intermittent therapy than continuous therapy. Serum IL-6 and IL-8 increased when complicated with infection and increase in IL-8 seemed more sensitive. CONCLUSION: Serum levels of IL-6, sgp130, IL-8 may reflect patient's responsiveness to ATRA treatment, predict hyperleukocytosis and intercurrent infection. ATRA induces APL cell differentiation possibly via gp130 signal transduction.

Adolescent↗
PubMed1998

[Radioimmunoimaging of hepatocellular carcinoma with 131I labeled antihepatoma monoclonal antibody Fab fragment].

OBJECTIVE: To study the effects of radioimmunoimaging (R11) of hepatocellular carcinoma with 131I labeled antihepatoma monoclonal antibody (HAb18) Fab fragment. METHODS: HAb18Fab was prepared by papain digesting HAb18, and it was radioiodinated with iodine-131 using high efficiency iodination method. The experiment consisted of two parts: ten nud mice bearing human hepatocellular carcinoma xenograft were injected intravenously with 131I-HAb18Fab 3,700 kBq/mouse, and six patients with hepatocellular carcinoma were injected intravenously with 131I-HAb18Fab 111-166.5 mBq/body. RESULTS: Ten nud mice bearing hepatocellular carcinoma, showed positive image. The optimum imaging time was 4.5-12 h after injection, and was 21.07 +/- 0.05 for tumor/liver higher than 5.83 +/- 0.05 of intact HAb18, and the reported 3.03. No tumor image was found in the control group of mice. Six patients with hepatocellular carcinoma, after injecting 131I-HAb18Fab 16 h, showed positive image. The optimum imaging time was 16-24 h earlier than 96 h of the reported 131I. CONCLUSION: R11 with 131I-HAb18Fab possesses the advantages of the location, qualitative analysis and earlier diagnosis. It is prospective in clinical application.

Animals↗
PubMed1998

[Insulin receptor substrate-1 and glucose transporter gene polymorphisms in noninsulin-dependent diabetes mellitus].

OBJECTIVE: To evaluate the role of insulin receptor substrate-1 (IRS-1) and glucose transporter-1 (GLUT1) gene polymorphisms in Chinese patients with noninsulin-dependent diabetes mellitus (NIDDM) and diabetic neophropathy (DN). METHODS: Aminoacid polymorphism in codon 972 of IRS-1 gene and the polymorphic Xba I site of GLUT1 gene were analyzed by PCR-RFLP in 131 patients with NIDDM and 124 normal subjects. DN was defined as persistent albuminuria and/or impaired renal function, without known cause of renal diseases other than diabetes. Insulin sensitivity index (ISI) and body mass index (BMI) were also calculated. RESULTS: The distribution of IRS-1 gene polymorphism showed no difference between patients with NIDDM and normal controls. The frequencies of Xba I (+/-) genotype (59% vs. 33%, P < 0.01) and Xba I (-) allele (37% vs. 21%, P < 0.01) were significantly higher in NIDDM patients than in normal subjects. To further explore the linkage of GLUT1 gene polymorphism with DN, we examined the GLUT1 genotype of NIDDM patients with or without renal damage. The frequency of Xba I (+/-) genotype (75% vs. 44%, P < 0.01) and Xba I (-) allele (44% vs. 29%, P < 0.05) was significantly higher in NIDDM patients with diabetic nephropathy than either those without nephropathy or normal subjects. However, there were no significant differences of GLUT1 genotype and allele frequency in NIDDM patients without nephropathy and normal controls. The presence of Xba I (-) allele appeared to have a strong association with the development of diabetic nephropathy. The odds ratio was 1.915, and the 95% confidence interval was 1.044-3.514. The association of Xba I (-) allele of GLUT1 gene with NIDDM partly reflected their close association with DN. Although there was no correlation between the gene polymorphism of GLUT1 and BMI, patients carrying the Xba I (-) allele showed a lower ISI. CONCLUSION: No association was found between the gene polymorphism of IRS-1 and NIDDM. THe Xba I (-) allele of GLUT1 gene might be taken as a genetic marker of NIDDM with diabetic nephropathy and this genetic susceptibility appears to be associated with the insulin resistance in patients with NIDDM.

Adult↗