Biomedical subjects

S Chen

Publications and source records attributed to S Chen.

At least 451 records · Page 25Linked to original sources

PubMed2000

A prospective randomized study of alpha-2b interferon plus hydroxyurea or cytarabine for patients with early chronic phase chronic myelogenous leukemia: the International Oncology Study Group CML1 study.

A prospective randomized international study of 143 patients showed no apparent early survival advantage conferred by combining cytarabine, rather than hydroxyurea, with INF as first-line CML therapy. Combinations of alpha-interferon (INF) and chemotherapeutic agents are currently first-line therapy for the majority of patients with chronic myeloid leukemia (CML). The International Oncology Study Group conducted a prospective randomized study comparing INF combined with hydroxyurea or cytarabine. The primary study aim was to compare the survival durations in these patient cohorts. Patients with early chronic phase CML were randomized to receive INF 5 million units (Mu) given five times per week subcutaneously plus hydroxyurea or cytarabine as required to achieve a complete hematologic response and to maintain a WBC count between 2x10(9)/L and 10x10(9)/L and a platelet count between 75x10(9)/L and 100x10(9)/L. Therapy continued as tolerated unless progressive or blast phase disease occurred. At 36 months, the actuarial survival rate was equivalent in both groups: HI group (79 patients) survival was 85% (95% CI, 68-100%), as compared to 95% (95% CI, 79-100%) in the CI group (64 patients). In conclusion if seems that there is no apparent early survival advantage conferred by combining cytarabine, rather than hydroxyurea, with INF as first-line CML therapy.

Adolescent↗

PubMed2000

PAR, a novel androgen regulated gene, ubiquitously expressed in normal and malignant cells.

During our work on the mechanism of hormone resistance of prostatic carcinomas, a novel gene that we called PAR (prostate androgen regulated) was isolated from an androgen resistant subline (LNCaP-OM) using a modified representational difference analysis. The complete sequence of the gene cDNA has 1029 nucleotides with a continuous reading frame of 438 bases encoding for 146 amino acids. Its deduced amino acid sequence has motifs for myristoylation and phosphorylation by protein kinase C. The PAR gene was overexpressed in all prostatic carcinoma cell lines studied (LNCaP, DU145, PC3 and LNCaP-OM) compared to the normal prostatic tissue. Furthermore, its expression was higher in androgen resistant prostate cancer lines DU145, PC3 and LNCaP-OM, in comparison to androgen sensitive LNCaP cells. The expression of this gene was down regulated by androgens in androgen sensitive prostate cells, but not in the hormone resistant cell lines. The PAR mRNA was detected in all 29 normal human tissues studied and overexpressed in most (67%) of their malignant counterparts. The PAR expression was higher in MCF7 and T47D breast cancer cell lines, as well as in all primary breast tumors studied compared to their normal tissue counterparts. The biological function of this gene is still unknown, but its ubiquitous expression in normal tissues and its overexpression in some malignancies suggest the PAR involvement in certain basic cellular processes and possibly, in malignant transformation.

Amino Acid Sequence↗

PubMed2000

Chinese herbal mixture PC SPES in treatment of prostate cancer (review).

The Chinese herbal preparation denoted PC SPES, a mixture consisting of extracts from eight herbs, is being used with increasing frequency by prostate cancer patients worldwide. Evidence has emerged that PC SPES is an effective modality that alleviates some symptoms in advanced prostate cancer in a significant proportion of patients including the cases that failed conventional therapy. This evidence as well as published data that show the effects of PC SPES in suppressing growth of prostate cancer in animal model studies, is reviewed together with the available data on the possible side effects of PC SPES. The review also covers in vitro studies that reveal the cell cycle specificity, induction of apoptosis, effects on androgen receptor and other molecular and metabolic changes induced by PC SPES that may explain its anticancer activity. Individual chemical components that are present in herbs of which PC SPES is composed, known to have anti-proliferative, antitumor, antimutagenic, analgesic and/or differentiation inducing activity, are listed and discussed. The effectiveness of PC SPES in prostate cancer is explained as due to its complex composition which may target many signal transduction and metabolic pathways simultaneously thereby eliminating the back-up or redundant mechanisms that otherwise promote cell survival when single-target agents are used.

Animals↗

PubMed2000

The mutation of insulin receptor substrate-1 gene in Chinese patients with non-insulin-dependent diabetes mellitus.

OBJECTIVE: To identify the relationship between mutation in the insulin receptor substrate-1 (IRS-1) gene and the incidence of non-insulin-dependent diabetes mellitus (NIDDM) in the Chinese population. METHODS: Samples were obtained from 68 Chinese patients with NIDDM and 68 control subjects. The +1700-(+)4437 bp fragment of the IRS-1 gene was screened by polymerase chain reaction (PCR)-single strand conformation polymorphism (SSCP) analysis. All SSCP variations were submitted to DNA sequence analysis. RESULTS: Two amino acid variations [GGG-->AGG (G971 R) and CCT-->TCT (P1079 S)] and 3 silent mutations [GAT-->GAC(D422D), CCA-->CCC(P737 P) and GCA-->GCG (A804 A)] were identified, among which the CCA-->CCC(P737 P) and CCT-->TCT(P1079S) have not been previously reported. All five variations were found in Chinese patients with NIDDM, while GCA-->GCG(A804A) was the only one found in control subjects. The overall incidence of the five variations in Chinese patients with NIDDM were much higher than that in control subjects (38.2% vs 7.4%, chi 2 = 18.42, P < 0.01). The most common polymorphism in the Chinese population was GCA-->GCG (A804A), and its frequency was significantly higher in Chinese patients with NIDDM than in controls (26.5% vs 7.4%, chi 2 = 8.84, P < 0.01). The homozygotes of the variation in patients with NIDDM and control subjects were 8.8% and 1.5%, respectively (chi 2 = 2.41, P > 0.05). CONCLUSION: These results indicate that there may be a relation between these nucleotide variations of IRS-1 gene and Chinese patients with NIDDM.

Adult↗

PubMed2000

[Bone marrow transplantation for beta-thalassemia major].

OBJECTIVE: To examine the feasibility of bone marrow hematopoietic stem cell transplantation for thalassemia major. METHODS: Bone marrow transplantation was performed on a 4-year-old patient with beta-thalassemia major, whose gene mutation was CD41-42/654. The donor was his brother. In the 850ml bone marrow, the nucleated cells were 5.6x10(8)/kg, CD(+)(34) cells 7.8 x 10(6)/kg, and colony-forming-unit-granulocyte-macrophages(CFU-GM) 5.7x10(5)/kg. HLA was one site mismatched, while RBC type matched. Pre-transplant conditions included Busulfan 16mg/kg, cyclophosphamide 200mg/kg and lymphoglobuline 88mg/kg. Cyclosporine and methotrexate were used for prevention of graft-versus-host disease(GVHD). RESULTS: After transplantation, the patient had grade II acute GVHD and cytomegalovirus(CMV) interstitial pneumonia; he was cured. White blood cells(WBC) and neutrophil granulocytes recovered to 1.1 x 10(9)/L and 0.4 x10(9)/L respectively on day 14 post transplantation. WBC was 4.5 x 10(9)/L on day 18, and descended for a time during treating interstitial pneumonia with Ganciclovir. Platelet(Plt) exceeded 50 x 10(9)/L on day 86 and recovered to normal 5 mothers and a half post transplantation. Hb reached 106g/L on day 128. The patient received the last blood transfusion on day 103. Before transplantation, the patient had to receive 200ml blood infusion per month for maintaining Hb 60-90g/L; after transplantation, his Hb kept up >110g/L for 6 months without blood transfusion. The gene type had changed to donor's CD41-42/N heterozygen. CONCLUSION: This is the first report on successful transplantation of bone marrow stem cell for thalassemia major in China, suggesting a new way to treat the disease and to expand the use of BMT. For treatment of CMV interstitial pneumonia post-transplantation, Ganciclovir should be dose enough and be used for at least 2 months.

Child, Preschool↗

PubMed2000

A survey on knowledge and skills in the early diagnosis of leprosy in general health services at different levels in Shandong Province, The People's Republic of China.

In the late phase of a leprosy control programme, problems arise with regard to the early detection and treatment of a small number of new incident cases. We describe a study in the province of Shandong, People's Republic of China, on the knowledge and skills regarding leprosy of general health service staff, including rural doctors, paramedical doctors at township level, doctors from county general and provincial hospitals and dermatologists. The results showed that there is a continuing need for suitable training programmes for medical staff in the general health services. Most dermatologists had good levels of knowledge and skills and more than 80% of new cases have been diagnosed in skin clinics in this province since 1990. Their participation in early diagnosis and training of staff should be strengthened.

Adult↗

PubMed2000

A method for expression cloning of transporter genes by screening yeast for uptake of radiolabelled substrate.

A method has been developed for the cloning of plasma membrane transporters by screening yeast transformed with a cDNA library for the accumulation of radiolabelled substrate. The applicability of the method is demonstrated by cloning the amino acid permease AAP1. A yeast mutant defective in proline uptake was transformed with an Arabidopsis thaliana cDNA library and plated on medium supplemented with L-[U-(14)C]proline. Yeast colonies accumulating radiolabelled proline were identified by autoradiography. The plasmids of these colonies were reintroduced into the yeast mutant and restoration of proline uptake was confirmed by L-[U-(14)C]proline uptake measurements. Whereas cloning of transporters by functional complementation requires that the substrate taken up is metabolized by yeast to promote growth, the method described here can be used to isolate transporters of substrates which are not metabolized. The method has great potential for the isolation of transporters of various substrates such as secondary plant products.

Arabidopsis↗

PubMed2000

Clinical observation on treatment of non-parvicellular carcinoma of the lung with jin fu kang oral liquid.

Jin Fu Kang Oral Liquid ([symbol: see text]), made of traditional Chinese drugs for supplementing qi and nourishing yin, was developed according to the common symptoms in lung carcinoma with deficiency of both qi and yin. Of the 96 cases in the Jin Fu Kang group, 1 case got complete remission (CR) after treatment, 8 cases partial remission (PR), 52 cases no change (NC), PR + NC covering 63.5%. Of the 52 cases in the group of Jin Fu Kang plus chemotherapy, 11 cases got PR after treatment, 26 cases NC, PR + NC covering 71.2%. Of the 25 cases in the chemotherapy group, 4 cases got PR after treatment, 11 cases NC, PR + NC covering 60.0%. The results show that the therapeutic effectiveness in the Jin Fu Kang group and the group of Jin Fu Kang plus chemotherapy was better than that in the chemotherapy group. The one-year survival rate and the two-year survival rate after treatment in the Jin Fu Kang group were 67.3% and 67.3% respectively; 66.7% and 66.7% in the group of Jin Fu Kang plus chemotherapy; and 40.3% and 0.0% in the chemotherapy group. The improvement of clinical symptoms, increase of body weight and improvement of health situation (KPS marks) after treatment in both the Jin Fu Kang group and the group of Jin Fu Kang plus chemotherapy were better than that in the chemotherapy group. Some indicators of immunology and hemogram after treatment were greatly improved in the Jin Fu Kang group, worse in the chemotherapy group, but no obvious improvement in the group of Jin Fu Kang plus chemotherapy.

Adenocarcinoma↗

PubMed2000

[Prognostic evaluation of heart-liver ratio of (99m)Tc-MIBI on liver cirrhosis].

OBJECTIVE: To evaluate heart-liver ratio (H/L) of (99m)Tc-MIBI on the prognosis of cirrhotic patients. METHODS: Retrospective cohort study was used to analyze the survival rate among the patients who had received H/L detection, and the H/L value was classified by Child-Pugh class. RESULTS: All the patients were followed up for 0.1 to 63 months. H/L ratio was significantly different among Child-Pugh A, B, C groups (0.85 +/- 0.15, 0.99 +/- 0.19, 1.15 +/- 0.27, F=5.09, P<0.01); 6-month, 1-year, and 2-year survival rates in H/L<1.0 group were significantly higher than those in H/L>1.0 group (85.9%, 57.4%, 57. 4% vs 50.0%, 39.4%, 19.7%, P<0.01 ). Among patients with Child-Pugh degree C, 6-month, 1-year, and 2-year survival rates in H/L<1.0 group were significantly higher than those in H/L>1.0 group (71.4%, 42.9%, 42.9% vs 27.3%, 18.2%, 0). CONCLUSION: H/L is an effective index for evaluating prognosis of cirrhotic patients, and it could be complemented by Child-Pugh classification.

Adult↗

PubMed2000

Gene therapy for murine liver cancer by adenovirus-mediated cytosine deaminase gene.

OBJECTIVE: To investigate anti-tumor effects of AdCD/5FC system on mice bearing MM45T.Li liver cancer. METHODS: IC(50), bystander effect and cell apoptosis were observed in vitro. After treatment of the tumor with AdCD in situ and injection of 5FC peritoneally into the mice, the anti-tumor effects were observed. RESULTS: When MOI=100, AdCD infected MM45T.Li was sensitive to 5FC, and the IC(50) was less than 50 micromol/L. When 10% MM45T.Li cells were infected with AdCD, 72% cells died after 5FC treatment, which showed significant bystander effect. Through TUNEL test and Hoechst 33258 staining, it was demonstrated that there was cell apoptosis after AdCD/5FC treatment of the MM45T.Li cell 21 day after treatment of the mice bearing tumor. The tumor volume was reduced significantly (F=20.33, P<0.05), and the median survival time was prolonged from 41-43 day to 49 day. CONCLUSION: AdCD/5FC system shows significant anti-tumor effects.

Adenoviridae↗

PubMed2000

New potential photodynamic therapeutic anti-cancer agents: synthesis and characterization of demethoxy amino-substituted hypocrellins.

A novel method was used to obtain demethoxy amino-substituted hypocrellin derivatives. The reaction condition was mild and amino substitution occurred at position 2 or 11 of hypocrellins with high yield. The photophysical and photochemical properties of the amino-substituted hypocrellins derivatives were investigated, and their significantly enhanced red absorptivities and strong active oxygen-generating functions qualified them as promising photodynamic therapeutic anti-cancer agents.

Antineoplastic Agents↗

PubMed2000

[A system of microcomputer analysis for biological oxygen consumption and its application].

This paper introduces a microcomputer system of data analysis and methods of measuring oxygen consumption for biological materials. The system overcame some disadvantages of operating inconvenience and difficulties of collective and analytic data by traditional means. The system possesses functions of automatic enactment, collection, save/take and analysis for many experimental data. It can be used to measure oxygen consumption of tissues, cells and mitochondria.

Animals↗

PubMed2000

[Effect of hypoxic hypercapnia on expression of endothelin-1 mRNA of pulmonary arterioles in rats].

OBJECTIVE: To investigate the effects of chronic hypoxic hypercapnia and ligustrazine on expression of endothelin-1 (ET-1) mRNA and the ultrastructure of pulmonary arterioles in rats. METHODS: Thirty rats were randomly divided into three groups: control group (A), hypoxic hypercapnic group (B), hypoxic hypercapnia + ligustrazine (lig.) group (C). ET-1 mRNA was observed in arterioles from rats by the technique of in situ hybridization. The average value of integral light density (LD) of ET-1 mRNA in pulmonary arterioles was detected by an image analysor and the relative content of ET-1 mRNA was calculated. RESULTS: (1) mPAP was significantly higher in rats of B group than that of A group (P < 0.01) and it was much lower in rats of C group than that of B group (P < 0.01). Differences of mCAP were not significant in three groups (P > 0.05); plasma ET-1 concentration was significantly higher in rats of B group than that of A group (P < 0.01), plasma ET-1 concentration was significantly lower in rats of C group than that of B group (P < 0.01); (2) Light microscopy showed that WA/TA (vessel wall area/total area) and SMC (the density of medial smooth muscle cells) were significantly higher in rats of B group than those of A group (P < 0.01). WA/TA and SMC were significantly lower in rats of C group than those of B group (P < 0.01). Electron microscopy showed proliferation of medial smooth muscle cells and collageous fibers of pulmonary arterioles in rats of B group, and ligustrazine could reverse the changes mentioned above; (3) Hybridization in situ showed that LD of ET-1 mRNA in pulmonary arterioles was significantly higher in rats of B group than that of A group (P < 0.01); LD of ET-1 mRNA in pulmonary arterioles was significantly lower in rats of C group than that of B group (P < 0.01). CONCLUSIONS: Increase of expression of ET-1 mRNA in pulmonary arterioles contributes to the development of pulmonary hypertension and structural remodeling of pulmonary arteries in chronic hypoxic hypercapnic rats. Ligustrazine can inhibit pulmonary hypertension by decreasing the expression of ET-1 mRNA in pulmonary arterioles.

Animals↗

PubMed2000

[Anatomical study and clinical applications of the tensor fascia lata myocutaneous flap].

OBJECTIVE: To explore the causes of blood circulation problems in 3 of 6 cases of pedicled tensor fascia lata myocutaneous flap transferring. METHODS: Anatomical study was performed on 16 cadavers (32 sides) after red emulsion injection. RESULTS: On 22 sides of 12 cadavers, the nutrient arteries lie in the muscle; on 2 sides of 2 cadavers, intramuscular nutrient arteries coexist with the big branches anterior to the muscle; on 4 sides of 3 cadavers, intramuscular nutrient arteries coexist with the big branches in the loose connective tissue deep to the muscle; on 4 sides of 3 cadavers, the nutrient arteries locate in the subcutaneous layer. According to the anatomical observations, much attention were paid to protect the vessels deep, superficial and anterior to the muscle during surgery, which resulted in successful clinical applications in 8 cases. CONCLUSIONS: The supplying arteries of the tensor fascia lata myocutaneous flap may exit not only intramuscularly, but also deep, superficial and anterior to the muscle. Special attention should be paid to them during operation.

Adolescent↗

PubMed2000

[Effect of Sophora flavescens Ait on cultured beating myocardial cells of coxsackie B3 virus infected newborn rat].

OBJECTIVE: Coxsackie B viruses (CVB3) are considered to be the most common etiologic agents of viral myocarditis. There are not any special anti-CVB3 drugs yet. From previous studies, the anti-CVB3 affect of sophora flavescens ait (SFA) had been discovered. Our experiment was to study the anti-CVB3 ability of SFA to cultured heating myocardial cells of CVB3 infected newborn rat. METHODS: The myocardial cells were divided into four groups: 1. infected group (n = 8), infected only with CVB3, not adding SFA; 2. treated group (n =8), infected with CVB3, adding SFA (100 microg/ml); 3. drug group (n=6), adding SFA (100 microg/ml) only; 4. control group (n = 6), not infected with CVB3, not adding SFA. RESULTS: The myocardial cells of the infected group had cell pathogenic effect (CPE) on the second day after virus inoculation, the CPE progressed rapidly from + to ++++. In contrast, no CPE in the other three groups was found. The LDH and SGOT of the infected group were higher than that in the other three groups, showing a significant difference (P <0.05). The virus titer of the infected group was higher than that of the treated group. There was no influence on normal myocardial cells if the concentration of SFA was lower than 300 microg/ml. When the concentration of SFA was 6.25 microg/ml 200 microg/ml, it showed protective effect on infected myocardial cells. CONCLUSIONS: The results of the experiment suggest that SFA might inhibit CVB3 replication in myocardial cells.

Animals↗

PubMed2000

[Reconstruction of anus in low rectum cancer operation].

OBJECTIVE: While low rectum cancer being resected with Mile's operation, the anus was reconstructed in situ simultaneously. METHODS: Thirty cases of artificial anus were perfectly reconstructed in situ with transferring of the gracilis and invaginating of the end of the sigmoid for the outer and inner sphincter of the anus. The artificial rectum valve was used for the rectum angle. RESULTS: The rate of excellent and good operative results reached 90.63%. CONCLUSION: The results show that this method is suitable for radical operation of low rectum cancer and functional incapacitation of the anus from other diseases as well.

Adenocarcinoma, Mucinous↗

PubMed2000

[Maintenance of foot sensory function by end-to-side neurorrhaphy].

OBJECTIVE: The purpose of this paper is to introduce the experience in maintaining or reconstructing foot sensory function after harvesting skin flap from the leg. METHODS: After dissecting the fasciacutaneous flap in the medial leg, the end-to-side neurorrhaphy was performed between the distal saphenous nerve and the sural nerve. When the retrograde-flow neurocutaneous island flap was raised, the end-to-side neurorrhaphy was carried out between the sural nerve carried by the flap and the cutaneous nerve of the foot dorsum. Also a less important cutaneous nerve branch can be harvested and implanted into the denervated flap in the foot with the other end of the nerve sutured to the lateral side of the cutaneous nerve of the foot dorsum. RESULTS: This operation was performed on three patients. Postoperative follow-up of 9 to 36 months revealed good results. CONCLUSION: This technique is simple and effective.

Adult↗

PubMed2000

[CO2 release from typical Stipa grandis grassland soil].

Determinations on the soil respiration in a typical Stipa grandis grassland of Inner Mongolica by the method of static chamber/alkaline absorbing show that there existed great spatial and temporal variances of soil respiration, and the factors controlling these variances were different. The seasonal variance of soil respiration had a close relationship with the aboveground biomass of S. grandis and the status of soil moisture. The total amount of annual CO2 release in 1995, 1997 and 1998 was estimated as 180, 45.8 and 225 gC.m-2.yr-1, respectively. Overgrazing greatly decreased the biomass of the community, and also, decreased the CO2 release from the soil. The possibility of establishing a dynamic model of soil respiration in grassland with precipitation as a driven factor was discussed.

Biomass↗