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Biomedical subjects

L Han

Publications and source records attributed to L Han.

At least 109 records · Page 6Linked to original sources
PubMed1996

[Left single lung transplantation in treatment of idiopathic pulmonary fibrosis: a case report].

A single left lung transplantation was performed on a 48-year-old male with end-stage idiopathic pulmonary fibrosis in February 1995. The surgical technic used was similar to that mentioned in the literature. The donor lung was perfused by cold Euro-Collins solution with a cold ischemic time of 190 minutes. Cardiopulmonary bypass was not used. The patient weaned from ventilator on the next day of operation (22 hours). Immunosuppression included cyclosporine, azathioprine and corticosteroid using until now and antithymocytic globuline for five days. Three episodes of acute rejection occurred within three months after operation, and all cured by bolus methyl-prednisolone given intravenously. The patient remains well nine months after operation with significant improvement of lung function and enjoies normal life.

Graft Rejection↗
PubMed1995

Sodium depletion and Fos-immunoreactivity in lamina terminalis.

Rats were either depleted of sodium by treatment with a diuretic or were made hypovolemic by injection of polyethylene glycol (PEG) and their brains were subsequently examined for induction of Fos-like immunoreactivity (FLI). FLI was observed in the lamina terminalis (LT) after both treatments; FLI was observed in the magnocellular neurosecretory hypothalamic areas only after PEG. Implications of these data for brain substrates of sodium appetite are discussed.

Animals↗
PubMed1995

Chimeric envelope glycoproteins constructed between amphotropic and xenotropic murine leukemia retroviruses.

A set of chimeric envelope proteins between amphotropic and xenotropic murine leukemia retroviruses (MuLV), two closely related members in the MuLV family, were constructed. The purpose was to examine the regions that could be successfully exchanged between these two similar viral envelope proteins. The data indicate that fully active chimeras can be built when the junction is either at the EcoRI site (amino acid 169) 42 amino acids N-terminal to the polyproline hinge of gp70 (named CH4) or at the ScaI site (aa 593) in the membrane spanning portion of p15E (CH1). However, a chimera at the AflII site (aa 125, CH5) and two in the C-terminal end of gp70 (aa 418, CH2; aa 326, CH3) were inactive. These results, taken together with other data from our laboratory and others, suggest that the entire gp70/p15E structure is sensitive to alterations and that even envelope proteins that are very similar have only a limited ability to exchange sequences.

3T3 Cells↗
PubMed1995

Corticosterone secretion in response to serotonin and ACTH by perfused adrenal of normal and athymic nude mice.

Adrenocortical secretory responses to chemical mediators and ACTH in CD1 ICR nu/nu (athymic) mice were compared with those in CD1 ICR (normal) mice. The bilateral adrenals of normal or athymic mice were perfused in situ with artificial medium equilibrated by 95% O2 + 5% CO2. Infusion of serotonin induced the secretory response of corticosterone significantly at 10 nM and markedly at 100 nM and the response at 1000 or 10000 nM declined as compared with that at 100nM in normal mice. Total corticosterone secretion in response to 100 or 1000 nM serotonin in athymic mice was about one fourth that in normal mice, respectively. Corticosterone responses to ACTH at the range of 10 to 300 pg/ml in athymic mice were comparable to those in normal mice. Infusion of histamine, platelet activating factor(PAF), or compound 48/80 did not induce significant corticosterone response in both normal and athymic mice. The data suggest that the congenital defect of the thymus and/or hair causes the hyporesponsiveness of adrenocortical cells to serotonin although the adrenal cortex of athymic mice is able to perform its function in response to ACTH.

Adrenal Cortex↗
PubMed1995

Regulation of jadomycin B production in Streptomyces venezuelae ISP5230: involvement of a repressor gene, jadR2.

The nucleotide sequence of a region upstream of the type II polyketide synthase genes in the cluster for biosynthesis of the polyketide antibiotic jadomycin B in Streptomyces venezuelae contained an open reading frame encoding a sequence of 196 amino acids that resembeled sequences deduced for a group of repressor proteins. The strongest similarity was to EnvR of Escherichia coli, but the sequence also resembled MtrR, AcrR, TetC, and TcmR, all of which are involved in regulating resistance to antibiotics or toxic hydrophobic substances in the environment. Disruption of the nucleotide sequence of this putative S. venezuelae repressor gene (jadR2), by insertion of an apramycin resistance gene at an internal MluI site, and replacement of the chromosomal gene generated mutants that produced jadomycin B without the stress treatments (exposure to heat shock or to toxic concentrations of ethanol) required for jadomycin B production by the wild type. When cultures of the disruption mutants were ethanol stressed, they overproduced the antibiotic. From these results it was concluded that expression of the jadomycin B biosynthesis genes are negatively regulated by jadR2.

Amino Acid Sequence↗
PubMed1995

A human protein selected for interference with Ras function interacts directly with Ras and competes with Raf1.

The overexpression of some human proteins can cause interference with the Ras signal transduction pathway in the yeast Saccharomyces cerevisiae. The functional block is located at the level of the effector itself, since these proteins do not suppress activating mutations further downstream in the same pathway. We now demonstrate, with in vivo and in vitro experiments, that the protein encoded by one human cDNA (clone 99) can interact directly with yeast Ras2p and with human H-Ras protein, and we have named this gene rin1 (Ras interaction/interference). The interaction between Ras and Rin1 is enhanced when Ras is bound to GTP. Rin1 is not able to interact with either an effector mutant or a dominant negative mutant of H-Ras. Thus, Rin1 displays a human H-Ras interaction profile that is the same as that seen for Raf1 and yeast adenylyl cyclase, two known effectors of Ras. Moreover, Raf1 directly competes with Rin1 for binding to H-Ras in vitro. Unlike Raf1, however, the Rin1 protein resides primarily at the plasma membrane, where H-Ras is localized. These data are consistent with Rin1 functioning in mammalian cells as an effector or regulator of H-Ras.

Amino Acid Sequence↗
PubMed1995

[The changes and clinical significance of interleukin 1 beta in pleural effusion].

An enzyme linked immunosorbent assay was set up by using anti-recombinant human interleukin 1 beta monoclonal antibodies. The interleukin 1 beta, anti-interleukin 1 beta autoantibody and interleukin 1 beta containing immune complex were detected in pleural effusion of 28 patients with bacterial infection cases pleurisy and 13 with lung cancer. The results showed that free interleukin 1 beta could be detectable in the early stage of pleurisy, and then transformed to the immune complex. The interleukin 1 beta containing immune complex were detectable in the pleeural effusions of all the 28 patients with pleurisy, but only two patients with lung cancer. The results suggested that this cytokine behaves differently in these two different kinds of diseases.

Antibodies, Monoclonal↗
PubMed1995

[Surgical treatment of multiple myxomas occurred in chambers of the heart].

From 1980 to 1994, 11 cases of multiple intracavitary myxomas were treated. Among them, 8 cases were in two chambers of the heart, and 3 in three chambes. 31 cardiac myxomas were removed in consecutive cases. The postoperative early results were good, but late results were unsatisfactory. 5 cases relapsed. Three cases died of cerebral embolism, and 2 were operated in postoperative relapse. Others survived over 10 years after surgery. The main points discussed are as follows: clinical characteristic for multiple intracavitary myxomas; echocardiographic diagnosis; selection of incision; postoperative relapse.

Adult↗
PubMed1995

[Effect of RII on the biological properties of human nasopharyngeal carcinoma cell lines].

N(4-hydroxycarbophenyl) retinamide (RII) is a new synthetic analog of retinoids with low toxicity. Its effect on the biological properties associated with tumor malignant behavior of human nasopharyngeal carcinoma cell lines (HNCs), including CNE-2Z parent cell lines and their variants L2, H2, L4 was studied. RII (10(-5) mol/L) caused detectable morphologic differentiation of HNCs. It inhibited growth of HNCs in vitro and decreased ability of these cells to penetrate matrigel-coated filters by using a reconstituted basement membrane invasion assay. These results suggested that RII might be a kind of useful anticancer drug.

Antineoplastic Agents↗
PubMed1994

Cloning and characterization of polyketide synthase genes for jadomycin B biosynthesis in Streptomyces venezuelae ISP5230.

Hybridizing fragments in the genomic DNA of Streptomyces venezuelae ISP5230, which produces the jadomycin group of angucycline antibiotics, were detected by probing with actI DNA from Streptomyces coelicolor A3(2). The hybridizing regions were isolated from a 16.5 kb insert of S. venezuelae DNA recovered from a genomic library cloned in a lambda replacement vector. Subcloning and sequencing of a 4.8 kb segment of the insert, containing regions hybridizing to actIII as well as actI, identified five open reading frames (ORFs). The deduced polypeptide products of the ORFs closely resemble in sequence the components of streptomycete type-II polyketide synthases (PKSs): the ORF1 product corresponds to the ketoacyl synthase, and the ORF2 product to a polypeptide closely related to the ketoacyl synthase and involved in determining chain length; the ORF3 product matches the acyl carrier protein; ORF4 encodes a bifunctional cyclase/dehydrase; and ORF5 encodes a ketoreductase. Integration into the chromosomal DNA of a plasmid containing a segment of the ORF2-ORF4 region severely depressed jadomycin B biosynthesis; since the integrant showed no change in growth or spore pigmentation, the cloned PKS genes are presumed to encode enzymes in the pathway for jadomycin biosynthesis.

Amino Acid Sequence↗
PubMed1994

Tannins of theaceous plants. V. Camelliatannins F, G and H, three new tannins from Camellia japonica L.

Two new complex tannins, camelliatannins F (3) and G (4), were isolated from the leaves of Camellia japonica L. (Theaceae), and their structures, each consisting of an epicatechin unit and a C-glucosidic ellagitannin moiety, were elucidated. A new dimeric hydrolyzable tannin, named camelliatannin H (5), was isolated from the fruits of this plant. Camelliins A (6) and B (7), and camelliatannin A (1) and 3 were also isolated from the fruits.

Carbohydrate Sequence↗
PubMed1994

[Surgical treatment and diagnosis of adult bronchogenic cysts].

Between 1974 and 1993, 22 adults with bronchogenic cysts were operated in our hospital: 14 men and 8 women, ranging from 11 to 62 years old. The location was mediastinal in 13 (59.1%) and intrapulmonary in 9 (40.9%). Cysts were symptomatic (chest pain and recurrent bronchiolitis) in 20 patients (91%). The perioperative complications include infection in lungs and in the cysts and dysphagia due to esophageal compression. Chest pain was the main symptom in mediastinal cyst and recurrent infection of lungs in intrapulmonary cysts. Plain chest radiographs showed round shadows. Occasional air-fluid levels, peripheral calcification may be found. Operation is the best method for treating cysts. All cysts were completely excised. No perioperative, late complication or recurrence developed in our patients. Operation was recommended in most instances to confirm the diagnosis, to relieve symptoms, and to prevent complications.

Adolescent↗
PubMed1994

Selenium supplement in the prevention of pregnancy induced hypertension.

The effect of selenium (Se) supplement on pregnancy was studied in 52 pregnant women with high risk factors of pregnancy induced hypertension (PIH). They were given natural Se dietetic liquid (100 micrograms/d) for 6-8 weeks during late pregnancy, and 48 controls were given placebo. They received similar routine prenatal care. The results revealed that Se supplement on the pregnant women prevented and decreased the incidence of PIH and gestational edema, and elevated the mother's blood Se level by 0.1008 +/- 0.091 ppm in the treated group while decreased by 0.0402 +/- 0.046 ppm in the control group (P < 0.01). The umbilical blood Se level was 0.2756 +/- 0.100 ppm in the treated group and 0.1544 +/- 0.051 ppm in the control (P < 0.01). The differences of the neonatal birth weight and the amount of postpartum hemorrhage between the two groups were not significant.

Adult↗
PubMed1993

Pyruvate enhances recovery of rat hearts after ischemia and reperfusion by preventing free radical generation.

Pyruvate protects myocardium from ischemic and anoxic injury, effects that have been attributed to beneficial metabolic alterations. Pyruvate also reacts with hydrogen peroxide in vitro, and pyruvate prevents free radical injury in other organs. Hearts supplied with 2 mM of pyruvate with glucose during reperfusion recovered significantly more mechanical function (81%) than those provided with 2 mM of acetate (which does not react with free radicals) and glucose (49%) or glucose alone (27%). Pyruvate significantly reduced free radical generation during reperfusion as measured with electron spin resonance using the spin-trap 5,5-dimethyl-1-pyrroline-1-oxide. In a model of direct oxidant stress, hearts were perfused with 0.28 mM of hydrogen peroxide. In this model, loss of function was almost entirely prevented by addition of 2 mM of pyruvate. From these results we conclude an important mechanism of protection when pyruvate is supplied during reperfusion is limitation of oxygen-derived free radical damage.

Animals↗