Search PubMed⌕ Search

Biomedical subjects

G Lin

Publications and source records attributed to G Lin.

At least 127 records · Page 7Linked to original sources
PubMed1997

[244 patients with hyperleukocytic acute leukemia. Shanghai Leukemia Cooperation Group].

To know the clinical characteristics and the prognostic factors of hyperleukocytic acute leukemia, we reviewed 244 patients with acute leukemia associated with hyperleukocytosis. Restrospective analysis and control study were used. Hyperleukocytosis occured in 8.5% of patients with acute leukemia. Hyperleukocytosis in ALL was more common than that in AML. Among AML with hyperleukocytosis, M5 subtype was the most. Hepatomegaly, splenomegaly, lymphadenopathy, DIC and CNSL were more frequent in hyperleukocytosis group. The complete remission rate was 41.4% for patients with hyperleukocytosis versus 54.2% for patients with non-hyperleukocytosis. The early mortality rate was significantly increased in hyperleukocytic patients (23.8%) as compared to the nonhyperleukocytic group (11.1%). Intracranial hemorrhage was the main cause of early death. The high risk factors of early death were: hemoglobin < or = 40 g/L, blood platelet < or = 30 x 10(9)/L, DIC, infection, CNSL at presentation. Acute leukemia with hyperleukocytosis has poor prognosis. Especially, acute myeloid leukemia with hyperleukocytosis must be taken seriously because of high early mortality rate.

Adolescent↗
PubMed1997

[Role of type IV collagene and type IV collagenase in the invasion and metastasis of salivary adenoid cystic carcinoma].

Using immunohistochemical ABC method, the authors studied the distribution of type IV collagen and type IV collagenase in 25 cases ACC. The result showed type IV collagen was found in vascular and epithelial basement membrance, and in partly cyst of sieve-like and tubular pattern, and in cytoplasm of tumor cell. Type IV collagenase was detected in membrance and cytoplasm of tumor cell. Expression of type IV collagen and type IV collagenase were correlated with pathologic type, TNM stage and metastasis. Much positive staining of type IV collagen was found in sieve-tubular pattern, early stage of TNM and without metastasis, but much positive staining of type IV collagenase was found in solid pattern, later stage of TNM and metastasis. The result suggested that the loss of type IV collagen and over-expression of type IV collagenase may be markers of malignance of ACC.

Biomarkers, Tumor↗
PubMed1997

[Study on red cell enzymes and isoenzymes in patients with leukemia and myelodysplastic syndromes].

OBJECTIVE: To define the prevalence of acquired red cell enzymopathy in leukemia and MDS patients and explore its clinical significance. METHODS: Red cell enzymes (G6PD, 6PGD, PK, ENOL, ADA, PNP,ALD) activities and PK,ADA isoenzymes were assayed by the methods recommended by ICSH and PAGE electrophoresis. RESULTS: The prevalence rate of G6PD deficiency was 43.1%, and of PK deficiency was 27.8%, in leukemia and MDS patients. The prevalence rates of PK, G6PD and PNP deficiency in MDS patients were 50%, 48% and 39.1%, respectively, while of ADA, ENOL and ALD over production in MDS patients were 69. 6%, 40% and 30. 4%, respectively. PK activity was increased in CML, while the PK isoenzyme pattern was normal. Administration of antitumor antibiotics to AL decreased G6PD and 6PGD activities (P < 0.05). ADA2 was expressed in MNC of AML (M4 and M5) and in RBC of CMML, but not expressed in ALL (P < 0.001). CONCLUSION: Determination of enzymes may be used as prognostic parameters in CML,a predictor of antitumor drug resistance in acute leukemia, and a differential parameter between MDS-RA and aplastic anemia and between CML and CMML.

Adolescent↗
PubMed1997

Production of recombinant goldfish growth hormone I in a baculovirus expression system.

The cDNA sequence encoding the growth hormone (GH) I gene of goldfish (gf GH-I) was cloned into the pSXIVVI+ X3 baculovirus transfer vector. This transfer vector, without the initiation codon (ATG) and using a SynXIV promoter to activate transcription, was constructed for a baculovirus expression system. The recombinant transfer vector with the gf GH-I insert was used to produce the recombinant baculovirus TnNPV-SX+ gf GH-I 21a. Both in vivo and in vitro approaches were used to test the expression of growth hormone I gene using TnNPV-SX+ gf GH-I 21a. For in vivo studies, larvae of Trichoplusia ni were infected with the recombinant baculovirus. Four days later, growth hormone-like immunoreactivity was detected in the hemolymph of these infected larvae. For in vitro studies, insect Spodoptera frugiperda 9(Sf9) cells were infected with TnNPV-SX+ gf GH-I 21a. After incubation for at least 24 hours, growth hormone-like immunoreactivity was detected in Sf9 insect cells as well as in the culture medium. Western blotting analysis of larval hemolymph and Sf9 cell contents after viral infection revealed a protein band of 22.5 kDa immunoreactive to goldfish growth hormone antiserum. This is consistent with the predicted molecular weight deduced from the cDNA of goldfish growth hormone I gene. These results, taken together, suggest that the baculovirus expression system can be used to produce the recombinant growth hormone of a fish species.

Animals↗
PubMed1997

[Infective factors of adult secretory otitis media].

There were histories of the upper expiratory tract infection in 49 out of 86 cases in adult secretory otitis media (SOM). Among them, thirty two cases were administrated antibiotics a week ago when the effusions were collected. The patient's Eustachian tubes in twenty nine cases were clinically ventilated. The endotoxins were positive in 39 out of 86 specimen tested with limulus assay, among these specimen, bacteria were cultured from 11 specimen. The data exibited that the appearance of the SOM is related to the existence of the infective factors in the middle ear cavity. The upper expiratory tract infection before the onset of the middle ear effusions is one of the important causes inducing the disease. The lower rate of bacteria culture than that of endotoxins is related with the administration of antibiotics before the onset of the disease. The administration of antibiotics in the treatment of the middle ear effusions will help to elimilate bacteria in the cavity of the middle ear effusions, improve the ventilating function of the Eustachian tube and make the effusions turn to disappearance.

Adolescent↗
PubMed1996

Effects of recombinant drug-specific single chain antibody Fv fragment on [3H]-desipramine distribution in rats.

Tricyclic antidepressant overdose can be reversed in rats by drug-specific antibody Fab fragments, but the required Fab dose may itself by toxic. We studied the potential use of a smaller, recombinant desipramine (DMI)-specific single chain Fv fragment (B9-sFv) for this purpose. Anesthetized rats received a tracer (subtoxic) dose of [3H]-DMI followed in 15 min by B9-IgG, B9-Fab, B9-sFv (0.1 mumol of binding sites) or BSA. Each of the active treatments produced a rapid and substantial increase in the serum radiolabel concentration, whereas BSA did not (P < 0.001). The increase in serum radiolabel concentration 1 min after treatment was 13.3-fold with B9-IgG, 10.0-fold with B9-Fab and 7.3-fold with B9-sFv. Serum antibody concentrations were also highest after B9-IgG and lower with B9-Fab or B9-sFv. The 24-hr urinary excretion of radiolabel did not differ among groups, but was extensive even in the BSA group and probably represented the excretion of DMI metabolites. B9-sFv concentrations in urine or buffer at 37 degrees declined by >90% over 24 hr, but this fragment was much more stable in serum, retaining 70% of its activity after 96 hr. These data demonstrate that B9-sFv can alter markedly the distribution of [3H]-DMI in vivo. The rapidity of this effect, and its magnitude in comparison with Fab fragment or IgG, suggest that further study of B9-sFv as a treatment of DMI overdose is warranted.

Analysis of Variance↗
PubMed1996

Is male gender a risk factor for conversion of laparoscopic into open cholecystectomy?

BACKGROUND: Based on a clinical observation that the conversion rate of laparoscopic cholecystectomy (LC) to open cholecystectomy (OC) is higher in males, we decided to review our records and to verify whether a significant difference in conversion rates exists between sexes. METHODS: A retrospective study on conversion rates of elective laparoscopic cholecystectomy (LC) into open cholecystectomy (LC) in relation to gender was carried out in 329 patients: 267 females and 62 males. RESULTS: Our data revealed that the probability of conversion is fivefold greater in males than females, 21% vs 4.5%, respectively (p = 0.0001). We attribute this striking difference to significantly more adhesions p = 0.0002) and anatomical difficulties (p = 0.003) in males during LC, leading to conversion. CONCLUSIONS: We conclude that conversion of LC to OC is more prevalent among males and is probably attributable to a greater incidence of anatomical difficulties.

Cholecystectomy↗
PubMed1996

Identification of lactams as in vitro metabolites of piperidine-type phenothiazine antipsychotic drugs.

The metabolism of the piperidine-type phenothiazine antipsychotic agents thioridazine, mesoridazine and sulforidazine was studied in vitro with 10,000 g liver supernatants obtained from rats and dogs. After incubations at 37 degrees C for different time intervals, the incubates were extracted with dichloromethane and the isolated compounds analyzed by HPLC, direct probe MS and on-line HPLC-MS. Five lactam metabolites of these three drugs were unequivocally identified in the rat in vitro system, but none was found in dog preparations; at least one lactam metabolite was identified for each drug in the rat. The lactams of thioridazine and thioridazine ring sulfoxide were characterized as metabolites of thioridazine for the first time in any system. The other three lactam metabolites, namely the lactams of mesoridazine, sulforidazine and mesoridazine ring sulfoxide, were found in vitro for the first time, although they have been previously reported as in vivo metabolites of these drugs. The results indicate that rat would be a more suitable animal model than dog for further studies on the formation of lactam metabolites of these drugs.

Animals↗
PubMed1996

Characterization of metabolites of clozapine N-oxide in the rat by micro-column high performance liquid chromatography/mass spectrometry with electrospray interface.

The metabolism of clozapine N-oxide was investigated in the rat (n = 6) after a single oral dose of 20 mg kg-1. The organic extracts of rat urine were separated by conventional high performance liquid chromatography (HPLC) and individual collected fractions were analyzed by micro-column electrospray HPLC/mass spectroscopy. The compounds identified in rat urine were clozapine N-oxide, clozapine, N-desmethylclozapine, 8-deschloro-8-hydroxyclozapine, 8-deschloro-8-thiomethylclozapine, N-desmethylclozapine, 8-deschloro-8-hydroxyclozapine, 8-deschloro-8-thiomethylclozapine, N-desmethyl-8-deschloro-8-thiomethylclozapine and 8-deschloro-8-methylsulfinylclozapine. With the exception of the unchanged clozapine N-oxide, no other metabolite containing a N-oxide functional group could be found, the concentrations of clozapine N-oxide, clozapine and N-desmethylclozapine excreted from rat urine were determined utilizing a conventional HPLC procedure with UV detection. The recoveries of these three analytes reported as the percentage of the dosage from the 0.24 h urine are 0.93 +/- 0.54%, 0.06 +/- 0.03% and 0.01 +/- 0.006% respectively.

Animals↗
PubMed1996

How does infected bile affect the postoperative course of patients undergoing laparoscopic cholecystectomy?

OBJECTIVES: To assess the rate of infected bile in patients undergoing laparoscopic cholecystectomy (LC) and to study the influence on the postoperative infective complications in this group of patients. METHODS: Bile samples of 247 patients undergoing LC were collected and cultured for aerobic and anaerobic bacteria. All patients were given prophylactic antibiotics. RESULTS: The overall rate of infected bile was 12.8% (56 positive cultures); of these, 54 were aerobic and 2 anaerobic bacteria. Only 2 patients developed infection at the umbilical site, and in both, the bile was sterile. None of the patients with positive bile cultures developed any signs of infection during a mean follow-up period of 26 months. CONCLUSION: The overall rate of septic complications following LC is extremely low, and at least in our study no correlation was found between infected bile and septic complications.

Adolescent↗
PubMed1996

Inflammatory cytokines in animal health and disease.

Inflammatory cytokines, including tumor necrosis factor (TNF), interleukin-1 (IL-1), IL-6 and IL-8, are rapidly induced early in a disease or injury process. They mediate and modulate myriad healing processes but, if overexpressed, may exacerbate the severity of a disease condition. In order to test this concept and to establish a foundation for the role of inflammatory cytokines in the pathogenesis of gram-negative bacterial infections in the respiratory tract of animals, the patterns of inflammatory cytokine expression were determined in experimental porcine pleuropneumonia. We observed that IL-1 and IL-6, but not TNF, were rapidly and dramatically elevated in the lavage fluid of the lung within 24 h of infection. The increased levels of IL-1 might contribute to increased severity of disease, but elevated IL-6 levels were consistent with a protective acute phase response. Additional studies were performed to examine the hypothesis that IL-4 expression later in infection might be involved in turning off the inflammatory response and promoting an antigen-specific humoral immune response. Interleukin-4 efficiently suppressed inflammatory cytokine production in alveolar macrophages. Its expression was induced in peripheral blood mononuclear cells by TNF, IL-4, and by reexposure to a specific antigen. To obtain the maximum amount of information on the role of inflammatory cytokines in animals of veterinary significance it will be useful to perform studies in species such that evolutionary relatedness will allow widespread application of the findings. Furthermore, the variety of molecules involved in inflammatory cytokine regulation will require much more extensive investigations of the relevant enzymes, inhibitors and receptors in veterinary species. Finally, the complexity and redundancy of immune defenses in animals mean that attempts to modulate health status through manipulation of inflammatory cytokines must be performed with caution and that a multiplicity of processes will be affected.

Animal Diseases↗
PubMed1996

Bacterial expression and characterization of an anti-desipramine single-chain antibody fragment.

Tricyclic antidepressant toxicity is a leading cause of death from intentional drug overdose. Monoclonal antibody Fab' fragments specific for the tricyclic antidepressant, desipramine, reverse acute drug toxicity but may themselves have adverse effects at therapeutic doses. To evaluate the characteristics of smaller antibody fragments, we cloned, expressed and characterized a 26 kD single chain Fv fragment (G5-sFv). A DNA sequence encoding VH-linker-V1 was constructed from hybridoma mRNA encoding a high affinity monoclonal desipramine specific IgG1 and expressed in E. coli. G5-sFv was produced at high levels as insoluble inclusion bodies. Single chain Fv was solubilized, folded in a redox buffer and affinity purified on desipramine-Sepharose. The affinity of G5-sFv for desipramine was similar to that of the corresponding monoclonal Fab' as measured by surface plasmon resonance (Fab' 5.5 +/- 0.5 x 10(8) M-1, sFv 2.3 +/- 0.5 x 10(8) M-1). G5-sFv administered to rats after a tracer dose of 3H-desipramine produced rapid and marked redistribution of drug from tissues into serum. G5-sFv was stable at 4 C for greater than 6 months but lost activity at higher temperatures. We conclude that desipramine-specific-single chain Fv expressed in E. coli retains the affinity of the parent antibody for desipramine. The pharmacokinetic effect of G5-sFv on desipramine distribution suggests that it may be useful as an antidote for desipramine overdose.

Amino Acid Sequence↗
PubMed1996

Prederivatization and high-performance liquid chromatographic analysis of alkaloids of bulbs of Fritillaria.

A method of prederivatization and HPLC with UV detection was developed for the simultaneous analysis of five major steroidal alkaloids of the Fritillaria species: verticine, verticinone, isoverticine, ebeiedine, and ebeiedinone. Derivatization was carried out by esterification of the hydroxyl-containing Fritillaria alkaloids to the corresponding naphthoates with 1-naphthoyl chloride. Reaction conditions were optimized and the yields of the derivatization were between 94 and 100% for all test alkaloids. Derivatized alkaloids were characterized by mass spectrometry and HPLC-MS. The validated HPLC-UV method demonstrated linear UV response at the sampling ranges used, and a test limit of 1 microgram/mL was determined for all analytes. This analytical method is simple, convenient, and readily reproducible. The developed method was applied to the analysis of the major pharmacologically active alkaloids in three medicinally used Fritillaria species: F. cirrhosa, F. thunbergii, and F. hupehensis. Five major Fritillaria alkaloids were simultaneously analyzed qualitatively and quantitatively from crude extracts of each of these herbs.

Alkaloids↗
PubMed1996

Is gamma-actin a regulator of amino acid transport?

A mutated yeast cell line incapable of growth in minimal medium with proline as the sole nitrogen source was restored to normal growth by transfection with a cDNA from mouse Ehrlich cells. The cloned cDNA (E51) was found to be 90% homologous to gamma-actin. Immediately after transfection with E51 cDNA, both alpha-aminoisobutyric acid (AIB) and proline uptake in the mutated yeast were increased, particularly at pH 5. The expression of the same E51 cDNA also enhanced amino acid uptake in Xenopus laevis oocytes after injection into the Xenopus nuclei. A mutated mammalian lymphocyte cell line (GF-17), deficient in system A transport, also showed increased Na(+)-dependent transport after transfection with E51 cDNA. Whereas the mock transfected GF-17 cells failed to grow in the selection medium, the transfectants with E51 cDNA grew better than the untransfected cells. The data are consistent with the conclusion that expression of E51 cDNA can modify inactive, endogenous amino acid transporters, permitting substantial amino acid uptake in cells deficient in amino acid transporter(s) and permitting rapid cell growth. The data suggest that the gamma-actin-like protein coded for by E51 cDNA may play a significant regulatory role in amino acid transport.

Actins↗
PubMed1996

Urinary metabolic profile in rat of 1-(2-methoxyphenyl)-2-methyl-2-(3-pyridyl)-1-propanone: a potential radioligand for functional diagnosis of adrenal pathology.

1. The metabolism of 1-(2-methoxyphenyl)-2-methyl-2-(3-pyridyl)-1-propanone (2-MPMP) was studied in the male Sprague-Dawley rat after 50 mg/kg, i.v. dose. 2. Organic solvent extracts of urine samples were directly analysed by reversed-phase gradient hplc. The identified metabolites were also isolated by preparative tlc, and analyzed by direct probe mass spectrometry. In the case of conjugated metabolites, the urine samples were deconjugated by enzyme hydrolysis prior to extraction. The structures of metabolites were confirmed by comparison of their chromatographic behaviours, UV spectra, and mass spectra with those of authentic standards. 3. The metabolites identified in the 0-24-h urine samples were 2-hydroxyphenyl-metyrapone (2-OHPMP) and 2-hydroyphenylmetyrapone N-oxide (2-OHPMP-NO), which were present predominantly as their glucuronide and/or sulphate conjugates. 4. 2-MPMP and four of its metabolites present in the 0-24-h urine samples were quantified by a reversed-phase hplc method. The mean total urinary excretion was 75.4% of the administered dose. The major metabolites present in the urine were conjugates of 2-OHPMP-NO (54.4%) and of 2-OHPMP (18.6%). The excretion of the unchanged drug, unconjugated 2-OHPMP and 2-OHPMP-NO accounted for 1.1, 1.1 and 0.2% of the dose respectively.

Adrenal Gland Diseases↗
PubMed1996

[Altered cytokeratin expression of the epidermoid formation in the tympanic cavity of human fetuses].

The epidermoid formation (EF) in the developing human fetal middle ear is believed to have relationship with congenital cholesteatoma. Sixteen EFs were included in this study, of which 15 were simple EFs and one was hyperplastic EF. Four cytokeratin antibodies PK, CK13, CK18, and CK19 were used in an ABC immunohistochemical technique to compare the expression of the cytokeratin in the EFs, middle ear mucosa and external acoustic meatus skin. The results showed that the simple EFs had the same staining pattern of middle ear mucosa for all four antibodies and were different from external acoustic meatus skin. It was suggested that the simple EFs do not have the properties of an epidermis. The hyperplastic EF had an altered cytokeratin expression comparing to that of the middle ear mucosa. The expression of CK19 disappeared in the structure while the normal middle ear mucosa nearby had a positive staining for this antibody. PK staining pattern, characterized by the more intensive in the surface layer of the EF, was similar to that of external acoustic meatus skin. It is suggested that hyperplastic EF may acquire certain properties of epidermis, and may develop into congenital cholesteatoma.

Antibodies, Monoclonal↗