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Biomedical subjects

S Yu

Publications and source records attributed to S Yu.

At least 253 records · Page 14Linked to original sources
PubMed1998

[Localization and quantitative analysis of insulin-like growth factor-I in placenta of extreme fetus].

OBJECTIVE: To investigate the immunohistochemical localization of insulin-like growth factor-I (IGF-I) in human placenta and to evaluate the role of IGF-I in fetal growth and placental growth. METHODS: In 72 tested samples, The cellular distribution of IGF-I in human placenta was determined by using immunohistochemistry. The relative area and mean absorbance were determined by using image analysis technique. Student's t-test was used to compare mean values between groups. RESULTS: IGF-I immunostaining was found in syncytiotrophoblast, cytotrophoblast and Hoffbauer's cells of chorionic villi and chorion of fetal membranes. The strongest immunoreactivity was observed in the syncytiotrophoblast and cytotrophoblast. The relative area and absorbance in placenta of SGA group were significantly lower than those of AGA group respectively (t = 4.65, P < 0.001; t = 2.15, P < 0.05). But the relative arca and absorbance of LGA were significantly higher than those of AGA (t = 8.72, P < 0.001; t = 7.82, P < 0.001). CONCLUSION: These results suggested that IGF-I in human placenta was principally synthsized and secreted by syncytiotrophoblast, cytotrophoblast, hoffbauer's cells of chorionic villi and chorion of fetal membranes. IGF-I is an improtant regulator of fetal and placental growth and development. It has the key role for macrosomia and IUGR forming.

Adult↗
PubMed1998

[Clinical analysis of 19 patients with pleural mesothelioma].

OBJECTIVE: To summarize the experience in the diagnosis of pleural mesothelioma. METHODS: Analysing the clinical data of 19 patients with pleural mesothelioma, including age, history of exposure to asbestos, clinical manifestations, imaging and laboratory examinations and metastases. RESULTS: None of the 19 patients had history of exposure to asbestos. Eight cases(42.1%) had no obvious thoracodynia, 9 cases(47.4%) had pleural effusion limited to the right chest, and in 2 cases(10.5%) the brachialis plexus was involved, and in 1 case (5.3%) malignant mesothelial cells were detected in the pleural effusion. Pleural thickening or nodules were found in 13 cases on CT and in 9 cases by B ultrasonographic examination. CONCLUSION: Exposure to asbestos is not the only cause of pleural mesothelioma. Chest pain is not always associated with pleural mesothelioma. CT and B ultrasonography are of good help in the diagnosis of pleural mesothelioma.

Adult↗
PubMed1998

The purification and identification of heme oxygenase isoforms from spleen tissue of rat and the expression of heme oxygenase-1 cDNA in COS-1 cells.

OBJECTIVE: To demonstrate that heme oxygenase (HO) isoforms exist in rat spleen treated with hematin and phenylhydrazine and to confirm that the isolated cDNA actually encodes HO-1 by expressing cDNA in monkey kidney cells (COS-1 cells) in order to prepare HO-1 mutant for inhibiting the natural enzyme. METHODS: The rat spleen microsomal fractions were first purified by diethylaminoethyl (DEAE)-Sephacel and hydroxylapatite. The activity of two isoforms (HO-1 and HO-2) of enzyme and their apparent molecular weight on sodium dodecyl sulfate (SDS)-polyacrylamide gel electrophoresis (SDS-PAGE) were measured. Secondly, using the isolated HO-1 cDNA clone, the expression plasmid pcDNA3HO1 was constructed and transfected into cultured COS-1 cells. The transfected cells were collected and disrupted by sonication, and the microsomes were prepared by ultracentrifugation. The activity of HO-1 was measured. RESULTS: Two isoforms were purified and identified in treated rat spleen and HO-1 was the predominant form. The ratio of HO-1 to HO-2 was 3.2:1. The apparent molecular weights of HO-1 and HO-2 were about 30 kD and 36 kD under reducing conditions, respectively. The HO-1 was highly expressed in endoplasmic reticulum of transfected cells. The specific band was located in molecular weight of 30 kD. The specific activity was five times higher than that of the control. CONCLUSION: The activity of expressed HO-1 in COS-1 cells is higher than that of purified enzyme from rat spleen tissue. It is suggested that this clone having an insert of 1030 base-pairs encodes HO-1 and that we can prepare HO-1 mutant by site-directed mutagenesis of HO-1 cDNA to prevent and treat hyperbilirubinemia.

Animals↗
PubMed1998

[Genetic diagnosis of alpha and beta thalassemia dual heterozygote].

OBJECTIVE: To perform genetic diagnosis of alpha and beta thalassemia dual heterozygotes. METHODS: PCR and beta-thalassemia allele specific oligonucleotide probe/reverse dot blot(ASO/RDB) techniques were used. RESULTS: Six cases of suspected alpha-thalassemia-1 and beta-thalassemia dual heterozygotes were found in genetic counseling and prenatal diagnosis. On genetic diagnosis, they were all Southeast Asia(SEA) type of alpha-thalassemia-1 and beta-thalassemia (--SEA/alpha alpha, beta T/beta A) dual heterozygotes. Out of them, 3 cases were alpha-thalassemia-1 and beta 41-42 (-TCTT), 2 were alpha-thalassemia-1 and beta-28(A-->T) and 1 was alpha-thalassemia-1 and beta IVS-II-654(C-->T) double heterozygotes. CONCLUSION: The detection of thalassemia dual heterozygotes facilitates the prenatal diagnosis with more precision.

Adult↗
PubMed1998

[A study of gene expression of PDGFBB and PDGFR as well as level of PDGFR activity in human glioma cells].

OBJECTIVE: To investigate the effect of PDGFBB autocrine loop on the development and progression of human gliomas. METHODS: 73 human glioma specimens of different stages were studied using in situ hybridization and immunohistochemical techniques. RESULTS: 62 (84.9%) of 73 cases expressed PDGFB mRNA. The positive rate and the amount of PDGFB mRNA increased correspondingly with the degree of malignancy. All of 73 gliomas expressed PDGFR alpha, PDGFR beta and phosphotyrosine protein (P-Tyr). The positive cell densities of PDGFR alpha, PDGFR beta and P-Tyr correlated positively with one another and increased with the malignancy as well as the expression level of PDGFB mRNA in the gliomas. However, there was no significant difference between positive cell densities of PDGFR alpha and PDGFR beta in any glioma group with different grading. CONCLUSIONS: PDGFBB autocrine loop existed generally in the glioma cells, the expression levels of PDGFBB and PDGFRs were well correlated with the tumor grading and the positive cell density of P-Tyr which could objectively reflect the activity of PDGFRs and the signal pathways. It's suggested that abnormally increased activity of PDGFBB autocrine loop might play an important role in the development and progression of gliomas.

Adolescent↗
PubMed1998

[A study on the relationship among activity of PDGFBB autocrine loop, cell proliferation and apoptosis in human glioma cells].

OBJECTIVE: To investigate the relationship between activity of autocrine loop of platelet-derived growth factor BB (PDGFBB), cell proliferation and apoptosis in gliomas. METHODS: 73 human gliomas with different degrees of malignancy were studied using in situ hybridization, in situ cell death detection (TUNEL method) and immunohistochemistry. RESULTS: The activity of PDGFBB autocrine loop and cell proliferation in gliomas correlated positively with each other and increased with the degree of tumor malignancy. Apoptosis decreased with the increase of malignancy and correlated negatively with the activity of PDGFBB autocrine loop as well as proliferation in glioma cells. CONCLUSION: These results suggest that all the above parameters have referential value in the evaluation of biological behavior of gliomas. Abnormal increase of activity of PDGFBB autocrine loop in glioma cells may be an important factor which stimulates cell proliferation and inhibits cell apoptosis and plays an important role in the development and progression of gliomas.

Adolescent↗
PubMed1998

[Nervous system damage in patients with sarcoidosis].

OBJECTIVE: For the purpose to evaluate the clinical characteristics of nervous involvement in sarcoidosis patients, and to improve the diagnostic skills. METHOD: 92 cases with sarcoidosis were reviewed, and 5 of them with damages to nervous system were retrospectively analyzed. RESULT: One of the 92 cases was proved to be brain sarcoidosis by autopsy, and 4 presented damages to meninges, cranial, spinal and peripheral nerves. The clinical manifestations of the above 5 cases included epilepsy, intracranial hypertension, motor weakness, facial paralysis and dysopia. CONCLUSION: Clinical manifestations of patients with sarcoidosis of the nervous system are varied. Sarcoidosis may be one of the potential causes of some unproven abnormalities in brain, spinal cord, cranial and peripheral nerves.

Adult↗
PubMed1998

[Preparation and characterization of monoclonal antibodies against Cryptosporidium parvum].

AIM: To develop and characterize the monoclonal antibodies(McAbs) against Cryptosporidium parvum (C. parvum). METHODS: BALB/c mice were immunized with purified oocyst antigens of C. parvum from human isolates and McAbs against C. parvum were prepared by using hybridoma technique. The characterization of McAbs was studied by means of indirect immunofluorescent assay (IFA) and Western blot analysis. RESULTS: Four clones of hybridoma cell lines secreting McAbs against oocyst antigens of C. parvum were obtained. The immunoglobulin subclasses of these four McAbs were identified as IgM (Z4C8,Z3D7) and IgG1(Z2B6,Z3D2) and their light chains were kappa chain. IFA results showed that three McAb (Z4C8, Z3D7 and Z3D2) conjugates produced a diffuse fluorescence in the Cryptosporidium sporozoites (CSP) and one (Z2B6) produced local fluorescence in the oocyst wall of C. parvum. Four McAbs could recognize 4 of 42 polypeptide antigen bands of CSP with molecular weights of 20.5 kDa, 33 kDa, 60.5 kDa and 95 kDa, among which both Z4C8 and Z3D7 could recognize 20.5 kDa band that was defined as a principal antigenic protein of CSP. CONCLUSION: These four McAbs possess their own characteristics of recognizing antigenic epitopes on CSP, but react specifically against antigens of C. parvum.

Animals↗
PubMed1998

[Facial soft tissue features analysis of normal Han race adults in Guangdong Province using computer-assisted-photogrammetric-system].

Facial soft tissue profile features of 150 normal native adults of Guangdong Province were analysed using computer-assisted-photogrammetric-system, which contained parameters written by polar coordinate. The results indicated that normal native adults of Guangdong Han race showed sex and region difference in features of facial profile soft tissue, and those parameters written by polar coordinate were helpful in the further study and clinical therapy.

Adult↗
PubMed1998

[Relationship between root rot on Panax notoginseng Burk. F. H. Chen and its environmental conditions].

OBJECTIVE: To probe into the relationship between root rot on Panax notoginseng and its environmental conditions for integrate control of the disease. METHOD: Field observation and analysis on the planting plots were conducted regularly. RESULTS: Root rot on P. notoginseng occurs extensively in Wenshan Prefecture, with two peaks of incidence per year. The first peak appears in March-April; and the second July-August. Air temperatures around 20 degrees C and relative humidities of higher than 95% are favorable for the disease to occur and spread. The root rot is severe when the light transmitting rate in the shade shed is too high(> 30%). The disease is severer in land of continuous cropping than in land of rotational cropping and land of new cropping. The severity of the rot increases with the years of continuous cropping. The art of field management also influences the occurring and spreading of the disease. CONCLUSION: The occurring and spreading of P. notoginseng root rot are closely related to its environmental conditions.

Drugs, Chinese Herbal↗
PubMed1998

[Studies on control of root rot on Panax notoginseng].

Chemical Control tests of pot, plot and field for Panax notoginseng root rot were conducted during 1995-1996. The results indicated that the chemical control is a effect measure to control rapidly occurring and spreading of Panax notoginseng root rot. It was the best treatment to coordinate use of bactericide and fungicide, obviously better than alone or mixed use of fungicide and also better than alone use of bactericide. In the pot and plot tests, the best coordinate treatment was the treatment of 10% phenazine plus 70% dexon plus 50% bavistin and plus water (1:1:500), the control effect was 70%; in the field test, the control effect of over 70% was also get with the treatment of 10% phenazine plus 70% dexon and plus small soil (1 Kg:1 Kg:150 Kg) per mu.

Benzenesulfonates↗
PubMed1998

Indefinite survival of peripheral nerve allografts after temporary Cyclosporine A immunosuppression.

It is hypothesized that unlike solid organ transplants immunosuppression of peripheral nerve allografts is needed only for the finite time period required for regeneration of proximal host nerve axons through the allograft and subsequent re-establishment of host end-organ connections. The aim of this study was to explore the consequences of temporary and continuous systemic Cyclosporine A (CsA) immunosuppression upon peripheral nerve allograft survival. Buffalo rats received Lewis nerve allografts under CsA immunosuppression (5 mg/kg/day) either continuously for 20 weeks, or for only 10 weeks followed by abrupt withdrawal. At 20 weeks, the nerve segments from both groups were regrafted into naïve Buffalo or Lewis recipients without further immunosuppression. These grafts were compared with isografts, unimmunosuppressed allografts and allografts immunosuppressed for 10 weeks in situ. By eight weeks following regrafting, the secondary Lewis recipients had rejected the temporarily immunosuppressed allografts and accepted the continuously immunosuppressed allograft, while the secondary Buffalo recipients accepted both the temporarily and continuously immunosuppressed allografts as assessed by histology and morphometry. Functional recovery was earlier in secondary recipient strain animals that received temporarily immunosuppressed allografts in comparison to those that received continuously immunosuppressed allografts. Analysis of secondary recipients of temporarily immunosuppressed allografts demonstrated greater in vitro MLR and LDA reactivity than did those receiving continuously immunosuppressed allografts. These findings support the hypothesis that donor alloantigens are lost or replaced by the recipient after immunosuppression withdrawal. Moreover, the change to recipient antigenicity in the nerve allograft is retarded and incomplete under continuous CsA immunosuppression, resulting in acceptance by both secondary donor and recipient strains upon regraftment.

Journal Article↗
PubMed1998

Association of active myofascial trigger points and cervical disc lesions.

We investigated the occurrence of active myofascial trigger points in specific muscle groups in relation to the existence of cervical disc bulging at various levels. One hundred and five patients (48 men, 57 women; mean age, 45.8 +/- 12.1 yr) who had active trigger points in the neck or upper back after trauma were divided into two groups on the basis of magnetic resonance imaging (MRI) evidence of bulging disc(s). The discN group consisted of 46 patients who had normal MRI findings in the cervical spine. The other 59 patients, with mild cervical disc bulging, were assigned to the disc' group. The correlations between specific muscles with active trigger points (clinical finding) and cervical disc lesions at specific levels (MRI finding) were analyzed. There were significant associations between the level of disc lesion and the muscles with trigger points, namely C3-4 lesions with levator scapulae and latissimus dorsi trigger points; C4-5 lesions with splenius capitis, levator scapulae, and rhomboid minor trigger points; C5-6 lesions with splenius capitis, deltoid, levator scapulae, rhomboid minor, and latissimus dorsi trigger points; and C6-7 lesions with latissimus dorsi and rhomboid minor trigger points. For each disc level, the average pain intensity (assessed using a numerical analog scale) of trigger points in certain correlated muscles (as indicated above) in the disc group was significantly higher than that in the discN group (p < 0.05 for all disc levels). We conclude that active trigger points are more likely to occur in certain muscles in the presence of cervical disc lesions at specific levels.

Adult↗
PubMed1998

Induction of donor-specific tolerance to rat nerve allografts with portal venous donor alloantigen and anti-ICAM-1/LFA-1 monoclonal antibodies.

BACKGROUND: Expendable autologous nerve available for repair of nerve injuries is limited. Cadaveric allografts could provide adequate nerve for grafting but are susceptible to rejection and currently require chronic systemic immunosuppression. METHODS: Age-matched Buffalo (RT1B) rats randomly assigned to 7 experimental groups received either a Lewis (RT1L) rat posterior tibial-sciatic nerve allograft or a Buffalo (RT1B) syngeneic isograft. Recipients were treated with anti-intercellular adhesion molecule-1 (anti-ICAM-1) and anti-leukocyte function-associated antigen-1 (anti-LFA-1) monoclonal antibodies (mAbs), intraportally administered ultraviolet B (UVB)-irradiated donor splenocytes, a combination of mAbs and UVB-irradiated donor splenocytes, or no immunosuppression. RESULTS: Histologic, electrophysiologic, and functional evaluation of nerve allografts 8 weeks after transplantation revealed a synergistic improvement in nerve allograft regeneration when monoclonal antibodies were combined with UVB-irradiated donor splenocytes. In vitro immunologic assessment correlated with the in vivo allograft function by demonstrating a donor-specific suppression of the recipient's response in mixed lymphocyte culture (MLC), cytotoxic T lymphocyte assay (CTL), and reduced T cell interleukin-2 production in both the group receiving UVB-irradiated alloantigen alone and the group receiving a combination of UVB antigen and mAbs. CONCLUSIONS: The combined use of mAbs directed against ICAM-1 and LFA-1 adhesion molecules with intraportally administered UVB modified donor antigen prevents nerve allograft rejection and synergistically improves nerve regeneration.

Animals↗
PubMed1997

In vitro analysis of gadolinium chloride abrogation of the systemic tolerance induced by portal venous administration of ultraviolet B-irradiated donor cells.

BACKGROUND: Normally, a Buffalo (BUF) recipient (RT1b) rejects a heterotopically transplanted Lewis (LEW) heart (RT1l) drained into the portal vein (PV) within 14 days. However, the addition of PV administration of 25x10(6) ultraviolet B (UVB)-treated LEW spleen cells (SC) to BUF recipients 7 days before cardiac transplantation results in 70% long-term allograft survival. METHODS: In this study, we used gadolinium chloride (GdCl3) (7 mg/kg/day) to selectively block the phagocytosis of recipient hepatic Kupffer cells before PV injection of UVB-treated donor SC to examine the mechanism of tolerance induction, as measured by in vitro analysis of mixed lymphocyte culture (MLC), T cell cytotoxicity, T helper cell precursors (pTH), and cytotoxic T cell precursors (pCTL) by limiting dilution analysis. RESULTS: A BUF recipient that received untreated or gamma-irradiated LEW SC intraportally reacted to in vitro stimulation by LEW alloantigen with increased MLC proliferation, T cell cytotoxicity, pTH and pCTL frequencies, and interleukin-2 production. In contrast, SC from BUF that received UVB-treated LEW SC were hyporesponsive on MLC stimulation by donor LEW alloantigen and exhibited markedly reduced cytotoxicity, pTH and pCTL frequency, and interleukin-2 production. However, normal in vitro responsiveness resulted with stimulation by third-party Brown-Norway (RT1n) SC, thus indicating that the systemic hyporesponsiveness was specific for the UVB donor alloantigen given PV. On the other hand, GdCl3 given by intravenous injection daily for 3 days before PV alloantigen blocked the induction of in vitro hyporesponsiveness. CONCLUSION: Therefore, prevention of alloantigen sequestration by GdCl3 inhibition of hepatic Kupffer cell phagocytosis was pivotal in preventing the development of portal venous tolerance.

Animals↗
PubMed1997

Evidence for the presence of CB2-like cannabinoid receptors on peripheral nerve terminals.

We have investigated whether there are cannabinoid CB2 receptors that can mediate cannabinoid-induced inhibition of electrically evoked contractions in the mouse vas deferens or guinea-pig myenteric plexus-longitudinal muscle preparation. Our results showed that mouse vas deferens and guinea-pig whole gut contain cannabinoid CB1 and CB2-like mRNA whereas the myenteric plexus preparation seemed to contain only cannabinoid CB1 mRNA. JWH-015 (1-propyl-2-methyl-3-( -naphthoyl)indole) and JWH-051 (1-deoxy-11-hydroxy-delta8-tetrahydrocannabinol-dimethylheptyl+ ++), which have higher affinities for CB2 than CB1 cannabinoid binding sites, inhibited electrically evoked contractions of both tissues in a concentration related manner. This inhibition was attenuated by 31.62 nM of the cannabinoid CB1 receptor selective antagonist SR141716A [N-(piperidin-1-yl)-5-(4-chlorophenyl)-1-(2,4-dichlorophenyl)-4-me thyl-1H-pyrazole-3-carboxamide hydrochloride] only in the myenteric plexus preparation. Vasa deferentia from delta9-tetrahydrocannabinol-pretreated mice (20 mg/kg i.p. once daily for two days) showed reduced sensitivity to JWH-015 and JWH-051. The results suggest that these compounds exert their inhibitory effects through cannabinoid CB1 receptors in the myenteric plexus preparation, but mainly through CB2-like cannabinoid receptors in the vas deferens.

Amino Acid Sequence↗
PubMed1997

RPE65, the major retinal pigment epithelium microsomal membrane protein, associates with phospholipid liposomes.

The retinal pigment epithelium (RPE)-specific protein RPE65 is the major protein of the RPE microsomal membrane fraction. Though RPE65 lacks transmembrane domains or signal peptide, detergents are required for its maximally effective solubilization in isotonic buffers. However, in 0.75-1.0 M KCl, RPE65 is as soluble without detergent, indicating a peripheral membrane association. We wished to understand why this non-membrane-inserted protein was so closely associated with RPE microsomal membranes. To explore the possible involvement of interactions with phospholipids, an isotonic salt-soluble extract of RPE was incubated with phosphatidylcholine (PC)/phosphatidylserine (PS)/phosphatidylinositol liposomes and centrifuged to sediment the liposomes. RPE65 cosedimented with the liposome pellet. RPE65 also cosedimented with synthetic dipalmitoyl-, 1-palmitoyl, 2-docosahexaenoyl-PC or dipalmitoyl-PS liposomes. Incubation with 1 mM Ca2+ or 1 mM EGTA had no effect, indicating a Ca2+-independent association. A spectrophotometric assay showed that this interaction of RPE65 with phospholipid vesicles resulted in increased light scattering, consistent with phospholipid vesicle aggregation. Resonance energy transfer experiments showed that any putative aggregation occurred without subsequent vesicle fusion. This PC affinity was further confirmed by incubation of RPE extract with dimyristoyl-PC-immobilized artificial membrane (IAM.PC) matrix. The RPE65 selectively bound and was elutable with 2% detergent. This RPE65-phospholipid liposome association may explain the solubilization characteristics of RPE65 and may be related to the function of RPE65 and to its physical association with the RPE smooth endoplasmic reticulum.

Animals↗