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Biomedical subjects

J C Li

Publications and source records attributed to J C Li.

At least 37 records · Page 2Linked to original sources
PubMed2001

[Study of Chinese herbal medicine in treating ascites and their mechanism in regulating lymphatic stomata].

OBJECTIVE: To study the therapeutic effect of Chinese herbal medicines (CHM) in treating ascites to elucidate its mechanism in regulating the lymphatic stomata and promoting the absorption of ascites from the peritoneal cavity. METHODS: Using scanning electron microscope (SEM) and computerized image processing and quantitative analysis assays, the CHM extract consisting of Atractylodes macrocephala, Salvia miltiorrhiza, Codonopsis pilosula, Alismatis orientale and Leonurus heterophyllus were studied. RESULTS: Intraperitoneal injection of nitric oxide (NO) supplier or CHM administration could cause the average area of lymphatic stomata obviously enlarged (P < 0.05), and the open numbers significantly increased (P < 0.01) in normal healthy mice. When L-notroarginine, a NO synthetase suppressor, was injected after CHM administration, it was found that the regulating effect of CHM on lymphatic stomata was inverted obviously, i.e. the average area and the density of lymphatic stomata were markedly reduced (P < 0.01). CONCLUSION: CHM might treat ascites through increasing the endogenous NO concentration to open the lymphatic stomata and in turn to conduct the peritoneal water through lymphatic path.

Animals↗
PubMed2001

[Application of tissue engineering in medicine].

Tissue engineering is a new field, which is based on engineering and life biology. It studies the structure of creatures and shows a wide prospect of treating the functional obstacle of tissues' and organs' wane. Lots of success has been achieved during the passed years and most of them were used on clinical. According to the origin of germinal layer during embryo development, the applying progress of tissue engineering in medicine is discussed.

Bioartificial Organs↗
PubMed2000

[Levels of plasma TF and TFPI activities in patients with acute leukemia].

OBJECTIVE: To investigate the changes of plasma tissue factor(TF) and tissue factor pathway inhibitor(TFPI) activities in the patients with acute leukemia. METHODS: TF and TFPI activities were measured by using chromogenic assays. RESULTS: Plasma TF activity in the patients with acute leukemia was higher and TFPI activity was lower than those in normal(P < 0.01). In 7 patients who underwent the first chemotherapy, the plasma TF activity was decreased after chemotherapy(P < 0.01), while TFPI activity increased(P < 0.05). CONCLUSION: The unbalance between plasma TF and TFPI activities contributes to the coagulant disorders in acute leukemia.

Adolescent↗
PubMed2000

[Effects of Buyang huanwu decoction on the release of vWF and the expression of tissue factor induced by tumor necrosis factor alpha in cultured bovine aortic endothelial cells].

OBJECTIVE: To study the effects of Buyang huanwu decoction (BHD) on the release of von Willebrand factor(vWF) and the expression of tissue factor(TF) activity induced by tumor necrosis factor alpha (TNF alpha) in cultured bovine aortic endothelial cells (BAECs). METHODS: BAECs from neonatal cox were cultured and 4-8 passages were used. Cells were incubated for 8 hours after addition of different treatments. The supernatant was used to measure vWF and BAECs lysate to determine TF activity. RESULTS: 1. Compared with the control, TNF alpha enhanced the expression of TF activity(12.79 +/- 2.59 vs. 4.69 +/- 0.83, P < 0.01) and the effects were in dose-dependent manner(r = 0.9712, P < 0.01); BHD inhibited the effects of TNF alpha(P < 0.01). 2. Compared with the control, TNF alpha promoted the release of vWF from endothelial cells (13.28 +/- 4.76 vs. 6.42 +/- 2.84, P < 0.01) and BHD inhibited the effect of TNF alpha(P < 0.01). CONCLUSION: BHD can inhibit the expression of TF and the release of vWF induced by TNF alpha.

Animals↗
PubMed2000

["Bu-yang huanwu tang" inhibited the pathogentic process of atherosclerosis induced by cholesterol-rich diet in rabbits].

BACKGROUND AND OBJECTIVE: "Bu-yang huanwu tang", a decoction of Chinese herbs widely used in the treatment for cardio- and cerebro-vascular diseases, has been demonstrated to be able to inhibit platelet adhesion and aggregation, to lower blood lipids, to regulate vascular tone from animal experiments. The aim of this study is to determine whether this decoction inhibits the pathogentic process of atherosclerosis induced by cholesterol-rich diet in rabbits. METHODS: Three groups of rabbits received the following different diets for 9 weeks: 1. standard diet; 2. atherogenic diet(standard diet plus 1% cholesterol and 3.3% fat); 3. atherogenic diet plus this decoction(5 g.kg-1.d-1). Plasma lipids, 6-keto-PGF1 alpha, endothelin levels were detected and the histological atherosclerotic changes were evaluated. RESULTS: This decoction inhibited the progression of aortic and abdominal aortic intimal plaques and reduced aortic intimal thickening. CONCLUSION: The anti-atherogenic mechanism might be related to the decrease of plasma cholesterol and triglycerides and the increase of PGI2. The facts suggest that "Bu-yang huanwu tang" has antiatherogenic and antithrombotic effects.

Animals↗
PubMed2000

High levels of fetal erythroblasts and fetal extracellular DNA in the peripheral blood of a pregnant woman with idiopathic polyhydramnios: case report.

Abnormal amniotic fluid volume can be associated with increased maternal risk as well as perinatal morbidity and mortality. Polyhydramnios is often indicative of fetal, placental or maternal problems. In a large proportion of patients the aetiology of the disorder is unclear. Here we report on a case in which numerous fetal erythroblasts and large quantities of extracellular fetal DNA were found in the peripheral blood of a pregnant woman with idiopathic polyhydramnios bearing a male fetus. Following enrichment of erythroblasts by magnetic separation (MACS) and anti-CD71 antibodies, approximately 45-fold more erythroblasts were determined per ml peripheral maternal blood than in matched controls (231 versus 5). Single cell multiplex polymerase chain reaction (PCR) of individually micromanipulated erythroblasts showed that approximately 122 of these were of fetal origin. The concentration of extracellular fetal circulatory DNA in maternal plasma was determined by real-time quantitative PCR and shown to be almost double that of the control group (749.2 versus 404 fetal genome equivalents per ml maternal plasma). It can be speculated that the increased intrauterine pressure in polyhydramnios leads to an enhanced influx of fetal cells and free extracellular fetal DNA into the maternal circulation. This hypothesis will have to be tested with further cases.

Adult↗
PubMed2000

Rat testicular myotubularin, a protein tyrosine phosphatase expressed by Sertoli and germ cells, is a potential marker for studying cell-cell interactions in the rat testis.

The full-length cDNA encoding the entire open reading frame (ORF) of rat myotubularin (rMTM) was isolated from a rat testis expression library by PCR. Among the three approximately 2.9-kb cDNAs that were sequenced, one clone was different from the other two clones. It contained seven extra amino acids of FVVLNLQ; this short stretch of extra sequence was found between Gln(421) and Phe(422) within the SET (Suvar3-9, Enhancer-of-zeste, Trithorax) interacting domain (SID) of rMTM. The rMTM ORF had 1,713 bp encoding for a 571 amino acid polypeptide and a calculated molecular weight of 65.8 kDa. A comparison between its deduced amino acid sequence and the GenBank database using BLAST revealed a 53.1% identity with human myotubularin protein (hMTM1), which is a member of the protein tyrosine phosphatase (PTP) family associated with X-linked myotubular myopathy. A 22 amino acid peptide NH(2)-TKVNERYELCDTYPALLAVPAN was synthesized based on the deduced amino acid sequence of rMTM and used for antibody production. By using immunoblot analysis, a 66-kDa protein was indeed detected in both Sertoli and germ-cell cytosols. rMTM mRNA was found in various tissues but was predominantly expressed in the testis, ovary, and skeletal muscle. Sertoli cell rMTM expression was stimulated by germ cells and enhanced when inter-Sertoli junctions were being assembled in vitro. A drastic reduction in testicular rMTM steady-state mRNA level correlated with the depletion of germ cells from the testis in vivo following either glycerol or lonidamine treatment. These results indicate that rMTM is a rat homologue of hMTM1 that may be a useful marker in monitoring the events of cell-cell interactions in the testis.

Amino Acid Sequence↗
PubMed2000

Cost-effective management of benign positional vertigo using canalith repositioning.

OBJECTIVE: The misdiagnosis and inappropriate treatment of benign positional vertigo have resulted in significant costs to the medical system. In the current medical-economic climate, there is an increased emphasis on cost control. Recent studies have shown that the canalith repositioning procedure (CRP) is effective; the next step is to show the impact of CRP in cost-effective management of benign positional vertigo. METHODS: Forty-six of 100 patients who underwent CRP for benign positional vertigo responded to a survey regarding the financial impact of their disease. They were asked to subjectively estimate the sum of all disease-related expenses. Objective substantiation of this number was estimated by tabulating physician data, laboratory data, and failed treatment costs. RESULTS: The subjective figure totaled $2684.74 per individual. Summation of the tangible objective figures yielded $2009.63 per patient, corroborating the subjective figure. CONCLUSIONS: Because CRP is a relatively simple procedure that can obviate many wasted expenses in most patients, we believe that it is very cost-effective and should be incorporated into routine practice.

Cost of Illness↗
PubMed2000

Sertoli cell prostaglandin D2 synthetase is a multifunctional molecule: its expression and regulation.

PGD2 synthetase (PGD-S; PGH2 D-isomerase; EC 5.3.99.2) is a bifunctional protein first identified in the mammalian brain. It acts as a PGD2-producing enzyme and a retinoid transporter. PGD-S is present in the testis, where its protein and messenger RNA levels are similar to those in the brain. In view of its diversified regulatory functions, we investigated its regulation using primary cultures of Sertoli cells in vitro to assess its role in the testis. When Sertoli cells were cultured in serum-free medium to allow the formation of specialized junctions, it was found that PGD-S expression increased steadily with time, coinciding with the formation of inter-Sertoli junctions in vitro. However, neither germ cells (using a Sertoli/germ cell ratio between 1:1 and 1:30 when Sertoli cells were cultured at a density of 5x10(4) cells/cm2) nor germ cell-conditioned medium affected the expression of Sertoli cell PGD-S in vitro. These results thus unequivocally demonstrated that germ cells do not play a role in regulating testicular PGD-S expression. Although FSH, dihydrotestosterone, and testosterone had no apparent effect on Sertoli cell PGD-S expression, the addition of progesterone(1x10(-11) to 1x10(-9) M) and T3 (1x10(-11) to 1x10(-9) M) to Sertoli cell cultures elicited a significant increase in PGD-S expression by as much as 4.5- and 2.5 fold, respectively. As PGD-S is a known retinoid transporter, the effects of all-trans-retinoic acid and all-trans-retinal on Sertoli cell PGD-S expression were also assessed. Both compounds were found to induce Sertoli cell PGD-S expression. In summary, PGD-S is a putative Sertoli cell product whose expression is regulated by progesterone, metabolites of vitamin A, and T3. In view of its dual biological properties, a study of its regulation and physiology will yield new insights into understanding its role in the testis.

Aging↗
PubMed2000

Benzophenone C-glucosides from Polygala telephioides.

Three novel benzophenone C-glucosides, 3'-C-beta-D-glucopyranosyl-2',4',6',3-tetrahydroxy-4-methoxybenzophen one, 3'-C-beta-D-glucopyranosyl-2',4',6'-trihydroxy-3,4-dimethoxybenzophen one and 4'-C-beta-D-glucopyranosyl-2',3',5',6',3-pentahydroxybenzophenone, named telephenones A, B, and C were isolated from the whole plant of Polygala telephioides WILLD and their structures determined by analysis of spectroscopic data.

Glucosides↗
PubMed2000

[A study of transgenic IFV cattle integrated with human serum albumin gene].

The mammary gland expression vector (pcDNA 3.1-GCALBm) containing the full-length sequence of human serum albumin (hALB) cDNA and intron 1 as well as the goat beta-casien gene promoter and 5' up-stream regulatory sequence was constructed. The vector was micro-injected into bovine IVF eggs. The embryos were in vitro cultured to the late stage of morulae, and then few embryo cells were aspirated for the implantation detection of target gene integration and SRY DNA sequence using nested-PCR. Afterwards, ten integrated embryos were selected to transfer into eight recipients and three were pregnant. The pregnant rate was 37.5%(3/8). However, two were miscarried in mid-trimester but one was pregnant at term to deliver a male transgenic cattle integrated with hALB mini-gene. The transgenic efficiency was 12.5% (1/8).

Animals↗
PubMed2000

[Repairing of inguinal scar contracture deformity in children with transpositional fasciocutaneous flap].

OBJECTIVE: To investigate the repairing method of inguinal scar contracture deformity in children with transpositional fasciocutaneous flap of anterior-medial side of thigh. METHODS: From August 1989 to August 1999, 33 cases with inguinal scar contracture deformity were adopted in this study. Among them, there were 26 males and 7 females, aged from 3 to 11 years old. The transpositional fasciocutaneous flap consisted of a huge tongue-shape flap with a pedicled triangular flap between the edge of skin defect and the above tongue-shape flap. The maximal size of the transpositional fasciocutaneous flap was 18 cm x 10 cm and the minimal size was 13 cm x 8 cm, the transpositional angle was 60 degrees to 80 degrees. During operation, the tongue-shape flap was used to repair the inguinal region and the triangular flap was used to repair the donor site in one stage. RESULTS: All the flaps survived. The function and appearance of perineum were satisfactory. CONCLUSION: The transpositional fasciocutaneous flap is suitable for repairing the inguinal scar contracture deformity in children, and skin graft is unnecessary.

Burns↗
PubMed2000

[Laboratory diagnosis of Acanthamoeba keratitis].

OBJECTIVE: To find a rapid method for diagnosing Acanthamoeba keratitis and identifying Acanthamoeba. METHODS: 10% potassium hydroxide (KOH) wet-mount preparations, Acanthamoeba culture, inverted phase contrast microscopy, and pathological examination using H. E. staining and PAS staining. RESULTS: Using corneal scrapings and corneal materials obtained from surgery, 7 cases and 5 cases of Acanthamoeba keratitis were diagnosed by 10% KOH wet-mount preparations. 6 strains of Acanthamoeba were isolated in corneal materials of 6 cases by protozoa culture method. The cysts, trophozoites and pseudopods on the trophozoites of Acanthamoeba were directly observed under the inverted phase contrast microscope. The cysts and trophozoites of Acanthamoeba were seen by H. E. staining and PAS staining with 20 h. CONCLUSION: Acanthamoeba keratitis could be rapidly diagnosed by 10% KOH wet-mount preparations and inverted phase contrast microscopy. Acanthamoeba organisms could be directly observed and identified under inverted phase contrast microscope.

Acanthamoeba↗
PubMed1999

Optimal proliferation of a hematopoietic progenitor cell line requires either costimulation with stem cell factor or increase of receptor expression that can be replaced by overexpression of Bcl-2.

In vitro proliferation of hematopoietic stem cells requires costimulation by multiple regulatory factors whereas expansion of lineage-committed progenitor cells generated by stem cells usually requires only a single factor. The distinct requirement of factors for proliferation coincides with the differential temporal expression of the subunits of cytokine receptors during early stem cell differentiation. In this study, we explored the underlying mechanism of the requirement of costimulation in a hematopoietic progenitor cell line TF-1. We found that granulocyte-macrophage colony-stimulating factor (GM-CSF) optimally activated proliferation of TF-1 cells regardless of the presence or absence of stem cell factor (SCF). However, interleukin-5 (IL-5) alone sustained survival of TF-1 cells and required costimulation of SCF for optimal proliferation. The synergistic effect of SCF was partly due to its anti-apoptosis activity. Overexpression of the IL-5 receptor alpha subunit (IL5Ralpha) in TF-1 cells by genetic selection or retroviral infection also resumed optimal proliferation due to correction of the defect in apoptosis suppression. Exogenous expression of an oncogenic anti-apoptosis protein, Bcl-2, conferred on TF-1 cells an IL-5-dependent phenotype. In summary, our data suggested SCF costimulation is only necessary when the expression level of IL5Ralpha is low and apoptosis suppression is defective in the signal transduction of IL-5. Expression of Bcl-2 proteins released the growth restriction of the progenitor cells and may be implicated in leukemia formation.

Cell Differentiation↗
PubMed1999

[Expression of tissue factor of astrocytes and its signal transductional pathways].

The aim of this study was to observe the expression of tissue factor (TF) of astrocytes in basic culture medium and under the condition stimulated by thrombin and to explore the relevant signal transduction pathways. The results showed that 4-bromo calcium ionophore (A23187) and phorbol 12-myristate 13-acetate (PMA) enhanced significantly the TF expression of astrocytes, but the expression was decreased markedly by trifluoperazine (TFP) and 1-(5-isoquinolinyl sulfonyl)-3-methyl-piperazine (H7) in the basic medium. Thrombin increased significantly the TF expression of astrocytes, which was obviously inhibited by TFP and H7. The results above indicate that astrocytes can express TF activity in the basic medium, which is promoted by thrombin, probably through some pathways involving Ca2+/CaM and protein kinase C (PKC).

Animals↗
PubMed1998

Quantification of prostaglandin D synthetase in cerebrospinal fluid: a potential marker for brain tumor.

Prostaglandin D synthetase (PGD-S; prostaglandin-H2 D-isomerase, EC 5,3,99,2), a 30 kDa glycoprotein also known as beta-trace protein that catalyzes the formation of prostaglandin D2 (PGD2) from PGH2, was purified to apparent homogeneity from human cerebrospinal fluid (CSF) using a two-step procedure involving HPLC on a Vydac C8 reversed-phase column and high performance electrophoresis chromatography (HPEC) using a 10% T SDS-polyacrylamide gel. The purity of PGD-S isolated from CSF was confirmed by silver stained SDS-polyacrylamide gel and direct protein microsequencing (NH2-APEAQVSVQPNFQ). A highly specific polyclonal antibody was prepared against this protein for immunoassay development. Using an ELISA, it was found that the concentration of PGD-S in CSF did not alter significantly in different pathological conditions of the central nervous system (CNS). These include dementia (n = 9), hydrocephalus (n = 4), neuropathy (n = 11), optic neuritis (n = 4), multiple sclerosis (n = 11), and demyelinating syndrome (n = 11), when compared to normal individuals (n = 12); however, the level of PGD-S in the CSF obtained from patients with brain tumor (n = 11), was reduced by as much as 2-fold when compared to control samples (n = 12) illustrating PGD-S is a potentially useful marker for brain tumor.

Amino Acid Sequence↗
PubMed1998

mcl-1 is an immediate-early gene activated by the granulocyte-macrophage colony-stimulating factor (GM-CSF) signaling pathway and is one component of the GM-CSF viability response.

mcl-1, a bcl-2 family member, was originally identified as an early gene induced during differentiation of ML-1 myeloid leukemia cells. In the present study, we demonstrate that Mcl-1 is tightly regulated by the granulocyte-macrophage colony-stimulating factor (GM-CSF) signaling pathway. Upon deprivation of survival factor from TF-1 myeloid progenitor cells, Mcl-1 levels quickly dropped prior to visible detection of apoptosis of these cells. Upon restimulation of these deprived cells with GM-CSF, the mcl-1 mRNA was immediately induced and its protein product was accordingly resynthesized. Analysis with Ba/F3 cells expressing various truncation mutants of the GM-CSF receptor revealed that the membrane distal region between amino acids 573 and 755 of the receptor beta chain was required for mcl-1 induction. Transient-transfection assays with luciferase reporter genes driven by various regions of the mcl-1 promoter demonstrated that the upstream sequence between -197 and -69 is responsible for cytokine activation of the mcl-1 gene. Overexpression of mcl-1 delayed but did not completely prevent apoptosis of cells triggered by cytokine withdrawal. Its down regulation by antisense constructs overcame, at least partially, the survival activity of GM-CSF and induced the apoptosis of TF-1 cells. Taken together, these results suggest that mcl-1 is an immediate-early gene activated by the cytokine receptor signaling pathway and is one component of the GM-CSF viability response.

Amino Acid Sequence↗