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Biomedical subjects

J Jin

Publications and source records attributed to J Jin.

At least 55 records · Page 3Linked to original sources
PubMed2001

[The effect of calponin and caldesmon in regulation of the gastrointestinal motility during pathophysiological adaptation].

OBJECTIVE: To investigate the expression of calponin (CaP) and caldesmon (CaD) in the gastrointestinal tract and their effect in regulating gastrointestinal motility during physiological and pathological adaptation. METHODS: Models of chronic gastrointestinal motility hyperfunction in mice were induced by intragastric administration of senna extraction and models of chronic gastrointestinal motility hypofunction in rats were established with carbon tetrachloride induced cirrhosis, CaP and CaD were detected in the gastrointestinal tract of different model groups using SDS-PAGE and Western blot. The color development of Western blots was scanned using densitometric scanning. The relative contents of gastrointestinal CaP and CaD were compared with control animals with different state of gastrointestinal motility. RESULTS: Animal models of abnormal gastrointestinal motility were established in mice and rats. Densitometric quantification of CaP and CaD blots by CP1 and C98 mAbs showed that normal animal colon contained higher amounts of h1-CaP and CaD. In normal mice and rats, the content of CaP and CaD was successively in this order :colon > stomach > small intestine. The content was reduced in mice of chronic gastrointestinal motility hyperfunction, but the expression of CaP and CaD was promoted in rats with cirrhosis and declined to normal level after treatment with L-NAME. CONCLUSION: There is close relation between expression of CaP and CaD and state of gastrointestinal motility. CaP and CaD may inhibit gastrointestinal motility. These suggest that CaP and CaD may play a role in the regulation of gastrointestinal motility during physiological and pathological adaptation.

Animals↗
PubMed2001

[The effects of the polysaccharides from Dermatocarpon miniatum on oxygen radicals and lipid peroxidation].

OBJECTIVE: To study the effects of Dermatocarpon miniatum (DEM) polysaccharides scavenging oxygen radicals and inhibiting lipid peroxidation. METHODS: .OH was produced by Fenton reaction and O2-. was produced by the oxidation of pyrogallol. The inhibition to LPO was determined by the colorimetry for testing the relative content of MDA. RESULTS: DEM polysaccharides could scavenge oxygen radical. The amounts of scavenging 50% (EC50) .OH was 1.72 mg/ml, the EC50 for O2-. was 2.12 mg/ml. DEM polysaccharides could also decrease the content of MDA. CONCLUSION: DEM polysaccharides has the effects of scavenging oxygen radicals and the inhibition to LPO. Its activities showed positive correlation with the amounts.

Antioxidants↗
PubMed2001

[Combination of mycophenolate mofetil with cyclosporine A and methotrexate as acute GVHD prophylaxis after unrelated donor allogeneic bone marrow transplantation].

OBJECTIVE: To evaluate the efficacy and safety of mycophenolate mofetil (MMF) in combination with cyclosporine A (CsA) and methotrexate (MTX) for prevention of acute graft versus host disease (GVHD) after unrelated donor allogeneic bone marrow transplantation (allo-BMT). METHOD: Twelve cases of unrelated donor allo-BMT were evaluated in a single center trial. The acute GVHD was prevented with 1 g MMF daily in addition to CsA 3 mg x kg(-1) x (-1) and MTX 10 - 15 mg at post BMT day1, day3, day6 and day11. RESULTS: Acute GVHD was found in one case (Grade IV) at the seventh day and two cases (Grade II) at the tenth day and seventeenth day after BMT. These patients were treated with a combination of MMF, methyprednisolone and CsA. The common adverse hematologic events of MMF was leukopenia. CONCLUSION: The preliminary study showed that MMF could be used effectively and safely for prevention of acute GVHD in unrelated donor allo-BMT.

Acute Disease↗
PubMed2001

[The combination of cyclosporin A and androgen in the treatment of chronic aplastic anemia].

OBJECTIVE: To explore the therapeutic effectiveness of combination of cyclosporin A (CsA) and androgen in the treatment of chronic aplastic anemia (CAA). METHOD: Androgen alone or combined with CsA for the treatment of CAA was compared by a randomized controlled clinical trial. RESULT: The efficacy of androgen combined with CsA (87.9%) was higher than that of androgen alone (57.1%). Therapeutic effectiveness of the combination treatment between the patients with positive and negative peripheral blood mononuclear cells (PBMNCs) inhibiting normal colony formation unit-granulocyte and macrophage (CFU-GM) test showed a significant difference (P < 0.005). CONCLUSION: Androgen combined with CsA had a much better efficacy than that of androgen alone in the treatment of CAA. The patients' PBMNCs inhibiting normal CFU-GM growth test can be used as an index of the treatment outcome. The side effects of the combination therapy are low and tolerable.

Adolescent↗
PubMed2001

Studies on the development of DNA vaccine against Cysticercus cellulosae infection and its efficacy.

DNA vaccine against Cysticercus cellulosae infection was developed and its efficacy was tested. A pair of primers specific to antigen B gene of C. cellulosae was designed which amplified the gene successfully with RT-PCR. The gene was ligated to PV93 vector, and the recombinant of antigen B gene and PV93 was transformed to JM83 cells. The transformed JM83 cells were cultured in a large scale and the plasmid purified. Based on the recombinant plasmid. a DNA vaccine was developed and used to vaccinate two groups of experimental pigs. In each group, there was a routine vaccine, an enhanced vaccine and a control group. Groups 1 and 2 were challenged at 4 months and at 14 days post vaccination respectively with eggs of Taenia solium. The antibody response was also tested with ELISA. The results suggested that all animals vaccinated AgB gene DNA vaccine, no matter by routine or enhanced vaccine, their antibodies reached maximum peak 23 days post vaccination and decreased gradually. When the animals were challenged 4 months after vaccination, they had strong immunity and the parasites decrease rates were 91.2% and 93.1% respectively. When pigs vaccinated with AgB gene DNA vaccine were challenged 14 days post vaccination with 18,000 eggs/pig. The animals showed strong immunity and the parasite decrease rates were 99.5% and 84.9% respectively. However at that time, the antibodies did not reach the peak. While in the control group, the number of C. cellulosae was as many as 2,500. It was concluded that the pigs vaccinated with DNA vaccine had strong immunity against infection of eggs of T. solium.

Animals↗
PubMed2001

Three-dimensional correction of scoliosis using TSRH instrumentation.

OBJECTIVE: To evaluate the results of TSRH instrumentation in the correction of coronal, sagittal and rotational deformity of scoliosis. METHODS: From January 1998 to December 1999, thirty-two consecutive patients (6 males, 26 females)with scoliosis underwent anterior or posterior spinal instrumentation and fusion using TSRH instrumentation. Of these cases, 21 were idiopathic scoliosis and 11 were congenital scoliosis. The average age at surgery was 16.4 years (range, 11 approximately 45 years). The mean Cobb angle at surgery was 71.2 degrees range, 44 degrees approximately 125 degrees) in the coronal plane, and 49. degrees range, 16 degrees aprroximately 67degrees in the sagittal plane. Rotational deformity (Nash-Moe) ranged from I to III degree. Preoperative apical translation averaged 4.8 cm (range, 3 approximately 9 cm). RESULTS: The average follow-up duration was 13.3 months (range, 10 approximately 24 months). At the final follow-up, the mean Cobb angle in the coronal plane was 26.6 (range, 10 degrees approximately 73 degrees), with a 63.8% of improvement. Sagittal alignment was well maintained with a mean Cobb angle of 28 degrees (range, 10 degrees approximatelky 45 degrees). The average correction of rotation of the apical vertebra was I degree. The average apical translation was 1.6 cm (range, 0.5 approximately 5.0 cm) representing a correction rate of 66, 7%. Complication was noted in two cases with an incidence of 3.1%, one case had superficial infection and the other one had lower hook dislocation. There was no neurologic deficit and pseudoarthrodesis in this series. CONCLUSION: TSRH instrumentation is an effective and convenient three-dimensional correction system with a lower rate of complication, which can not only correct the coronal and rotational deformity, but maintain the sagittal alignment as well.

Adolescent↗
PubMed2001

[Synthesis and electrochemical behavior of new symmetrical porphyrin and cobalt(II) complex].

The synthesis and characterization of mercapto-porphyrin and its cobalt(II) complex are reported. A new method was used to synthesize the porphyrin. These compounds have not been reported previously. Their structural assignment of the porphyrin and its cobalt(II) complex were based on the elemental analysis, UV-Vis, IR and 1H NMR spectra. The elemental analysis data for C44H30N4H4 was C, 69.32(69, 44) H, 4.30(4.24) N, 7.35(7.36). The data of UV-Vis spectra indicated that soret and Q bands of the TMTBP displayed a red-shift in comparison with TPP. The IR spectra of TMTBP showed that the peak of delta (N-H) disappeared, when the cobalt(II) complex was formed. The 1H NMR spectra proved that a new mercapto-porphyrin has been synthesized. This paper also reported electrochemical behavior of new compounds in DMSO by cyclic voltammetry and differential pulse voltammetry.

Chemical Phenomena↗
PubMed2000

Distribution of leukotriene B4 receptors in human hematopoietic cells.

Leukotriene B4 (LTB4), a product of arachidonic acid metabolism, plays an important role in inflammatory responses. We have cloned from human erythroleukemia cells, a G protein-coupled receptor, designated P2Y(7), which was later identified as the receptor for LTB4 (B-LTR). We have investigated the distribution of LTB4 receptors in various hematopoietic cells. Northern blotting and reverse transcription-coupled polymerase chain reaction (RT-PCR) analyses using radiolabeled LTB4 receptor cDNA as a probe indicated the presence of LTB4 receptor mRNA in peripheral blood leukocytes but not in platelets. Flow cytometry analysis of peripheral blood cells using specific LTB4 receptor antibodies revealed that monocytes, granulocytes, and lymphocytes, but not platelets, express LTB4 receptors. RT-PCR-Southern hybridization analysis revealed that peripheral blood leukocytes and human umbilical vein endothelial cells express the LTB4 receptor. Of the hematopoietic cell lines tested, promonocytic U937 cells, promyelocytic HL-60 cells, K562 cells, and human erythroleukemia cells express the LTB4 receptor. These results suggest a physiological role for the LTB4 receptor in the stimulation of monocytes, neutrophils, and endothelial cells.

Amino Acid Sequence↗
PubMed2000

Stromal cell-derived factor-1 and macrophage-derived chemokine: 2 chemokines that activate platelets.

Platelets play roles in both thrombosis and inflammation, and chemokines that are released at sites of inflammation could potentially activate platelets. Among the chemokine receptors expressed on platelets, the CXCR4 is the receptor for chemokine stromal cell-derived factor-1 (SDF-1), and the CCR4 is the receptor for macrophage-derived chemokine (MDC). Of the chemokines tested, SDF-1 and MDC were the only 2 that activated platelets. Both are weak agonists, but they enhanced response to low-dose adenosine 5'-diphosphate (ADP), epinephrine, or serotonin. When SDF-1 and MDC were added together, full and brisk platelet aggregation occurred. Platelet activation by these 2 chemokines appears to involve distinct pathways: SDF-1 inhibited an increase in cyclic adenosine monophosphate (cAMP) following prostaglandin (PG) I(2), while MDC had no effect. In contrast, MDC, but not SDF-1, lead to Ca(++) mobilization by platelets. Further, second-wave aggregation induced by MDC in platelet-rich plasma was inhibited by aspirin, ADP scavenger creatine phosphate/creative phosphokinase (CP/CPK), and ARL-66096, an antagonist of the ADP P2T(AC) receptor involved in adenylyl cyclase inhibition. But the aggregation was not affected by A3P5PS, an inhibitor of the ADP P2Y receptor. SDF-1-induced aggregation was inhibited by aspirin, but it was only slightly affected by CP/CPK, ARL-66096, or A3P5PS. Finally, the presence of chemokines in platelets was determined. Reverse transcriptase-polymerase chain reaction studies with platelet RNA did not detect the presence of SDF-1 or MDC. In summary, SDF-1 and MDC are platelet agonists that activate distinct intracellular pathways. Their importance in the development of thrombosis at sites of inflammation needs to be further evaluated.

Actins↗
PubMed2000

First chelated chiral N-heterocyclic bis-carbene complexes

[formula: see text] First chiral bidentate bis-carbene complex of Pd(II) prepared from a bis-imidazolium salt derived from (S)-2,2'-bromomethyl-1,1'-binaphthyl exists in both cis- and trans-square planar geometry. These and the corresponding trans-Ni(II) complexes are remarkably resistant to high temperature, air, water, and silica gel chromatography. The Pd complexes catalyze Heck reactions.

Journal Article↗
PubMed2000

Fluorescence Excitation Spectrum of a (2)Pi(3/2)-(2)Pi(3/2) Transition of NiF.

In this study, a supersonic beam of NiF was produced by the reaction of SF(6) with a dc discharge-sputtering source of nickel atoms. The laser-induced fluorescence excitation spectrum of a (2)Pi(3/2)-(2)Pi(3/2) transition has been recorded in the range of 500-520 nm and rotational structure of 506.5-nm band analyzed under the 30 K rotational temperature. Our data are consistent with a (2)Pi(3/2) ground state for NiF. The lifetime of this band is measured. Copyright 2000 Academic Press.

Journal Article↗
PubMed2000

Induction of Ro/SSA antigen expression on keratinocyte cell membrane by heat shock and phorbol 12-myristate 13-acetate as well as estradiol and ultraviolet B.

Skin is one of the main target organs in lupus erythematosus and in some circumstances, skin lesions precede systemic manifestations. Previous studies have demonstrated that Ro/SSA antigen antibody might be involved in the pathogenesis of lupus erythematosus. The present study was performed to investigate the factors regulating expression of Ro/SSA antigens on the cell surface of keratinocytes. Cultured normal human keratinocytes were treated with 50-200 mJ/cm(2) of ultraviolet B (UVB) irradiation, 10(-9) to 10(-5) mol/l of 17beta-estradiol, 5-10 microg/l of phorbol 12-myristate 13-acetate (PMA), and 42 and 45 degrees C heat shock, respectively. The Ro/SSA antigen expressions were determined by indirect immunofluorescence. The results showed that keratinocytes receiving UVB irradiation expressed Ro/SSA antigen on cell membranes in a dose-dependent fashion. 17beta-estradiol treatment also induced Ro/SSA antigen expression dose-dependently. Keratinocyte expression of Ro/SSA antigens was also induced by heat shock stimulation. The 45 degrees C heat shock showed a stronger effect than 42 degrees C heat shock. Keratinocytes incubated for 24 h after heat shock had more antigen-expressing cells than those incubated for 6 h after heat shock. PMA at 5 and 10 microg/l also strongly induced Ro/SSA antigen expression. These results suggest that Ro/SSA antigen expression can be regulated by many factors and that protein kinase C signal transduction pathway might be involved in this process.

Autoantigens↗
PubMed2000

Measurement of nitric oxide released in the rat heart with an amperometric microsensor.

Nitric oxide (NO) plays an important role in various physiological processes, acting either as an intra- and intercellular messenger or as a toxic agent. The detection and quantification of NO have been accomplished by a variety of methodologies. In the present study, real-time production of NO in the rat heart was continuously measured by using a novel copper-platinum microparticle-modified NO electrochemical microsensor. The linearity range of the microsensor is between 8.0 x 10(-8) and 4.8 x 10(-6) mol L-1 and the detection limit is 3.0 x 10(-8) mol L-1. NO release from the rat heart stimulated by the agonists L-arginine and acetylcholine was observed, and the responses were decreased by the NO synthase inhibitor L-N omega-nitroarginine. In addition, the effect of sodium nitroprusside (SNP), a NO donor, was also studied. SNP increases the concentration of NO in the rat heart. The experiments showed that electrochemical detection is suitable for detecting and quantifying NO in biological systems.

Acetylcholine↗
PubMed2000

The P2Y1 receptor mediates ADP-induced p38 kinase-activating factor generation in human platelets.

U46619, a thromboxane A2 mimetic, but not ADP, caused activation of p38 mitogen activated protein (MAP) kinase in aspirin-treated platelets. In nonaspirinated human platelets ADP activated p38 MAP kinase in both a time-and concentration-dependent manner, suggesting that ADP-induced p38 MAP kinase activation requires generation of thromboxane A2. However, neither a thromboxane A2/prostaglandin H2 receptor antagonist SQ29548 and a thromboxane synthase inhibitor, furegrelate, either alone or together, nor indomethacin blocked ADP-induced p38 kinase activation in nonaspirinated platelets. Other cycloxygenase products, PGE2, PGD2, and PGF2alpha, failed to activate p38 kinase in aspirin-treated platelets. Hence, ADP must be generating an agonist, other than thromboxane A2, via an aspirin-sensitive pathway, which is capable of activating p38 kinase. AR-C66096, a P2TAC (platelet ADP receptor coupled to inhibition of adenylate cyclase) antagonist, did not inhibit ADP-induced p38 MAP kinase activation. The P2X receptor selective agonist, alpha, beta-methylene ATP, failed to activate p38 MAP kinase. On the other hand, the P2Y1 receptor selective antagonist, adenosine-2'-phosphate-5'-phosphate inhibited ADP-induced p38 kinase activation in a concentration-dependent manner, indicating that the P2Y1 receptor alone mediates ADP-induced generation of the p38 kinase-activating factor. These results demonstrate that ADP causes the generation of a factor in human platelets, which can activate p38 kinase, and that this response is mediated by the P2Y1 receptor. Neither the P2TAC receptor nor the P2X1 receptor has any significant role in this response.

15-Hydroxy-11 alpha,9 alpha-(epoxymethano)prosta-5↗
PubMed2000

Role of Q190 of MuLV RT in ddNTP resistance and fidelity of DNA synthesis: a molecular model of interactions with substrates.

Gln190 of MuLV reverse transcriptase (RT) plays an important role in the catalytic mechanism of MuLV RT for its conservative and non-conservative mutant derivatives exhibit low catalytic activity. We now report that both Q190N and Q190A MuLV RTs are more efficient in their activity to incorporate ddNTPs and exhibit higher fidelity than the wild-type (WT) enzyme of DNA synthesis in both RNA- and DNA-directed reactions. To obtain some insight into the structural basis for the differential utilization of dNTP and ddNTP by the mutant enzymes, we modeled the binary and the ternary complexes of MuLV RT using corresponding HIV-1 RT structures and available structure of the fragment of MuLV RT. Q190 of MuLV RT appears to be essential for the interaction with 3'OH of dNTP. The lack of a 3'OH moiety in ddNTP does not permit the binding of ddNTPs to WT MuLV RT. However, the shorter side chain of Q190N (or A) mutant MuLV RT and the absence of 3'OH in ddNTP result in the rearrangement of hydrophobic interactions favoring the binding and limited incorporation of ddNTPs. In addition, while modeling the binary and ternary complexes of MuLV RT, we noted that in the formation of the ternary complex, an interaction of Q190 with dNTP substrate requires a shift from its interaction with the template base. This may be achieved by a small conformational change or motion of the loop between beta9 and alphaH containing Q190, which may correspond to the conformational change step requiring participation of Q190 during the catalytic reaction as reported in an earlier biochemical investigation.

Base Sequence↗
PubMed2000

Color Doppler flow imaging of the facial artery and vein.

The purpose of this study was to provide some guidelines with respect to the location of the facial vessels, display the potential inverted blood flow of the facial artery, and reemphasize the value of color Doppler ultrasound studies in flap planning. An anatomic study of the facial artery and vein was done using color Doppler ultrasonography in 12 adults. The artery and the vein were located together at the lower border of the mandible. Around the oral commissure and under the nasal ala, they were located apart from each other with variable distances. This divergence of the facial vein from the artery is important information in the planning of axial pattern flaps. Furthermore, the reverse flow was observed in 12 patients after the blood flow of the facial artery was stopped by applying pressure manually at the lower border of the mandible. Observation of the reversed flow confirms the possibility of safe elevation of a retrograde flow-arterialized flap based on the distal portion of the facial artery.

Adolescent↗
PubMed2000

3'-end formation of baculovirus late RNAs.

Baculovirus late RNAs are transcribed by a four-subunit RNA polymerase that is virus encoded. The late viral mRNAs are capped and polyadenylated, and we have previously shown that capping is mediated by the LEF-4 subunit of baculovirus RNA polymerase. Here we report studies undertaken to determine the mechanism of 3'-end formation. A globin cleavage/polyadenylation signal, which was previously shown to direct 3'-end formation of viral RNAs in vivo, was cloned into a baculovirus transcription template. In vitro assays with purified baculovirus RNA polymerase revealed that 3' ends were formed not by a cleavage mechanism but rather by termination after transcription of a T-rich region of the globin sequence. Terminated RNAs were released from ternary complexes and were subsequently polyadenylated. Mutational analyses indicated that the T-rich sequence was essential for termination and polyadenylation, but the poly(A) signal and the GT-rich region of the globin polyadenylation/cleavage signal were not required. Termination was not dependent on ATP hydrolysis, indicating a slippage mechanism.

3' Untranslated Regions↗