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Biomedical subjects

H Lin

Publications and source records attributed to H Lin.

At least 109 records · Page 6Linked to original sources
PubMed2001

The metabolic effects of endotoxin are differentially affected by the pattern of GH administration in the rat.

GH treatment can increase the mortality and morbidity of critically ill patients. The mechanisms of these harmful effects of GH are unknown but have been, in part, ascribed to interactions between GH and the immune system. Because GH has pattern-dependent actions we have now compared the dose-related effects of continuous and intermittent GH treatment given with or without an endotoxin (lipopolysaccharide; LPS) challenge. Male Wistar rats (n=6 per group) were treated for 5 days with recombinant human GH (0, 10, 100 or 1000 microg/kg per day) using either continuous s.c. infusion by osmotic minipump or intermittent twice daily s.c. injections. On day 4, endotoxin (5 mg/kg, i.p.) was injected and the animals monitored for a further 16 h. LPS administration alone led to neutrophilia and lymphopoenia, with increased plasma concentrations of urea, cholesterol, triglyceride, insulin and leptin, and decreased levels of IGF-I. High dose GH infusion (1000 microg/kg per day) followed by LPS caused greater increases in plasma urea, cholesterol, triglyceride, sodium and magnesium, but lower plasma glucose and insulin levels, than treatment with LPS alone. In contrast, twice daily injections of GH did not enhance these effects of endotoxin. In conclusion, the effects of endotoxin on plasma electrolytes, lipids, urea, glucose and insulin are differentially affected by the pattern of GH administration in the rat.

Animals↗
PubMed2001

Effect of benzene, toluene, xylene on the semen quality and the function of accessory gonad of exposed workers.

The effects on semen and the function of accessory gonad of workers after short and long term exposure to benzene, toluene, and xylene were examined. The semen and blood of 24 married workers exposed to benzene, toluene, and xylene were collected. Routine sperm characteristic, acrosin activity, and Lactate dehydrogenase C4 (LDH-C4) relative activity were detected. The results showed that benzene, toluene, and xylene were found in the blood and semen of some ex-workers at workplaces where the air concentration of benzene, toluene, and xylene exceeded the maximum allowable concentration (MAC). No such solvents were detected in the blood and semen of workers of the control group. The sperm vitality and sperm motility decreased in the exposed workers. The mean acrosin activity, gamma-GT activity and LDH-C4 relative activity in the exposed workers were lower, and fructose concentration was higher than those in the control. There were negative correlations between sperm vitality, sperm activity, acrosin activity, or LDH-C4 relative activity and working history. These results suggest that the mixture of these solvents could affect the sperm and the function of accessory gonad. This might be one reason of the abnormal pregnancy outcome among the wives of workers exposed to benzene, toluene, and xylene.

Acrosin↗
PubMed2001

Up-regulation of transcription of smooth muscle myosin alkali light chain by ethanol in human breast cancer cells.

Both epidemiological and experimental studies indicate that ethanol is a tumor promoter and that chronic ethanol exposure enhances metastasis of breast cancer cells, and with an in vitro model (T47D human breast cancer cells), we have previously demonstrated that ethanol exposure stimulated the migration of breast cancer cells. In the present study, differential display reverse transcription polymerase chain reaction was used to identify ethanol-responsive genes in T47D cells. Three differentially displayed, ethanol-responsive gene fragments were identified, and their expression was confirmed by Northern blot hybridization. Sequence analysis revealed that one cDNA fragment represented the myosin alkali light chain (MLC 1sm) of human smooth muscle. The expression of MLC 1sm was found to be significantly higher in breast cancer cells than in normal mammary epithelial cells. With T47D cells, ethanol induced an additional duration- and concentration-dependent up-regulation of MLC 1sm. At 400 mg/dl, an ethanol-mediated increase was evident at 6 h (55% increase), peaked at 24 h (2.7-fold increase) following exposure, and diminished thereafter. At pharmacologically relevant concentrations (e.g., 100 mg/dl), ethanol produced a significant increase of MLC 1sm expression, and progressively higher ethanol concentrations resulted in more up-regulation. The half-life of MLC 1sm mRNA was not altered, however, the transcription rate of MLC 1sm was significantly increased by ethanol. MLC is a structural component of the cytoskeleton of eukaryotic cells, and it plays critical roles in the regulation of cell shaping, movement, and growth. Thus, ethanol-mediated up-regulation of MLC may be an underlying molecular mechanism for its tumor promoting effect.

Blotting, Northern↗
PubMed2001

[Studies on inhibiting activities of five antitumour drugs to human cancer cell in vitro with MTT assay].

The inhibiting activities of five antitumour drugs including "An ke su" to human cancer cell lines coming from 19 patients were measured in vitro with MTT assay, which can provide proper antitumor agents for clinical chemotherapy. The evaluation rate of medicine sensitivity is 89.47%, which is same as the result of clinical therapy. This method indicates the response of tumour cells to "An Ke Su" and other agents. Being simple, sensitive and rapid, it proves to be valuable in clinical therapy.

Antineoplastic Agents↗
PubMed2001

Aortic and mitral valve replacement with retrograde perfusion in the beating heart.

OBJECTIVE: To estimate the value of aortic valves and combined mitral valve replacement with retrograde perfusion in beating hearts. METHODS: Continuous retrograde coronary sinus perfusion with beating hearts was used in 83 patients undergoing aortic valve or aortic valve combined with mitral valve replacement, without application of cardioplegia. After aortic valve replacement, the retrograde perfusion was changed to antegrade perfusion for mitral valve replacement or correction of the other deformities (group A). Cold blood cardioplegia solution (15 degrees C) was infused at intervals in 20 cases (group B). The following parameters were tested: lactate, ET, CTn-T and MDA in blood; myocardial ultra-structure; and cardiac rhythm and cardiac output (CO). RESULTS: All biochemical values increased after cardiopulmonary bypass (P < 0.05-0.01). Empty and beating heart sinus rhythm was maintained in group A. Myocardial ultrastructure did not change significantly. The pump was stopped smoothly as the surgical procedure finished. No postoperative low cardiac output syndrome or arrhythmia was observed. Eight-one patients recovered smoothly, two died from renal failure or infective shock. When the pump stopped, all patients in group B were supported by 5-10 micrograms.kg-1.min-1 dopamine. Transient pacing was used in 9 patients. One patient died from low cardiac output syndrome. CONCLUSION: This method is a good myocardial protection which simulates physiologic status. It is applicable to aortic valve and combined mitral valve replacement of patients with large heart or heart failure and long time aortic cross-clamping. Ideal clinical effect can be achieved.

Adolescent↗
PubMed2001

[A multianalysis study on clinicopathologic factors related to lymph node metastasis in gastric cancer].

OBJECTIVE: To study the function of CD44v6, MMP-9, TIMP-1 and cNOS in the invasion and metastasis of gastric cancer and their value in estimating early lymph node metastasis. METHODS: Logistic stepwise regression model was used to analyze the influence of ten clinicopathological factors on the lymph node metastasis in 119 cases of gastric cancer. RESULTS: Using the established equation to estimate lymph node metastasis, the stronger the CD44v6 expression, the higher the frequency of lymph node metastasis; the frequency of lymph node metastasis was the highest in patients with positive MMP-9 and negative TIMP-1 expression. However, the frequency was the lowest in those with negative MMP-9 and positive TIMP-1 expression and that of positive expression in hemangio-lymphangio-endothelial cells of gastric cancer was relatively high. CONCLUSIONS: The intensity of CD44v6 expression, the imbalance between MMP-9 and TIMP-1 expressions and cNOS mRNA expression in the endothelial cells were highly useful for the preoperative diagnosis of lymph node metastasis in gastric cancer patients.

Adult↗
PubMed2001

[Effect of environmental factors on gonadal maturation as well as its ovulation and spawning in teleosts].

This paper reviewed the environmental factors affecting gonadal maturation as well as its ovulation and spawning in teleosts which include water temperature, sun-light, rainfall, current, chemical composition of waters, aquatic organisms, water pollution and so on. The impact of environmental pollution on the reproduction of teleosts was emphasized, aimed to approach strategies protecting fish germplasm resource from the standpoint of ecology.

Animals↗
PubMed2001

[Quantitative measurement on degradation degree of ecosystem in hilly region of western Liaoning Province].

Exactly measuring the degradation degree of ecosystems is the basis and precondition of restoring ecosystems. At present, degradation degree is usually analyzed qualitatively. In this paper, quantitative classification method was used to study the degradation degree of ecosystem in hilly region of western Liaoning, which was measured by the degradation degree of habitat. The result shows that the habitat in the northern slope of mountains has been degraded to certain stage between shrubbery and pioneer tree forest, which provides theoretical basis for vegetation restoration practice. Moreover, the result is beneficial for studying the degradation degree of ecosystems in other regions or of other types.

China↗
PubMed2001

[A case-control study on the risk factors of esophageal cancer in Jieyang City of Guangdong in China].

OBJECTIVE: To study the risk factors of esophageal cancer in Jieyang city of Guangdong province. METHODS: Two hundred and fourteen cases with pathological diagnosis of esophageal cancer were recruited at Jieyang Municipal People's Hospital in 1999. Two hundred and fourteen controls were selected from healthy residents matched with sex, age and residential places (town) of the cases. All cases and controls had resided in Jieyang city for over 20 years and were studied through a uniformed questionnaire. Non-conditional logistic regression was used for multivariate analysis. RESULTS: The important risk factors were over-hot tea drinking habit (OR:1.39-3.74), fast eating (OR:1.54-4.10), animal oil (OR:3.57-42.03) and meat consumption (OR:1.36-5.05) while the protective factors were tap water (OR:0.13-0.51) drinking habil for over 20 years. Histories of smoking and family esophageal cancer were not significantly correlated with esophageal cancer. CONCLUSION: The risk factors revealed in this study were commonly exposed to the residents of Jieyang city. Most of the factors were in agreement to the results from other similar studies, but the factors of animal oil and meat were unique in this study, which called for further studies.

Case-Control Studies↗
PubMed2001

Isolated craniosynostosis: prenatal ultrasound of scaphocephaly with polyhydramnios.

Craniosynostosis is an abnormal shape or dimension of the skull caused by premature closure of one or more skull sutures. It includes scaphocephaly, brachycephaly, oxycephaly, plagiocephaly, trigonocephaly, turricephaly, and a cloverleaf-shaped head. The only cases of craniosynostosis that have been reported concern fetuses with complex and marked craniosynostosis syndromes such as acrocraniofacial dysostosis, Apert's syndrome, Beare-Stevenson cutis gyratum syndrome, Calabro's syndrome, etc. Isolated or simple craniosynostosis, however, is a developmental anomaly rarely found on routine ultrasound examination. We present a case that was diagnosed as scaphocephaly with moderate polyhydramnios by prenatal ultrasound. No other structural anomaly was detected, and the karyotyping was normal. So isolated sagittal craniosynostosis was diagnosed prenatally and was confirmed by postnatal skull radiography as well as 3-dimensional computed tomography. The infant underwent bilateral parietal craniectomy at the age of 3 months. He obtained a good result with no mental problems 4 years after the operation. To our knowledge, this is the second report on the prenatal detection of an isolated form of craniosynostosis.

Adult↗
PubMed2001

[Sequence analysis of RAN4 of a severe isolate of rice stripe virus in China].

RNA4 segment of a severe isolate of Rice stripe virus, isolated from Liaoning province and designated as PJ isolate, was amplified, cloned and sequenced. RNA4 of PJ isolate had 2157 nucleotide in length. When compared with RNA4 of T and M isolates of Japan and CX isolate of Yunnan province of China that had been previously reported, we found that these four isolates could be divided into two groups. PJ, T and M isolates shared 97.0% and 97.0%-97.5% identities in vORF4 and vcOFR4 at the nucleotide level, respectively and formed one group. The sequences in 5' and 3' terminal non-encoding region were completely identical among these three isolates. In this group, PJ isolate was more closely related to T isolate than to M isolate. The length of intergenic region(IR4) of PJ isolate was as same as that of T isolate, and had 93.0% sequence identity. However, PJ IR4 had an insertion of 19 bp in length compared with isolate M and had only 85.0% sequence identity. CX isolate belonged to another group, which shared only 94.0% and 92.5%-93.5% sequences identities in vORF4 and vcORF4 at the nucleotide level, respectively, even though there were not significant difference between these two group at the amino acid level. There was an insertion of 84 bp in length in the IR4 of CX isolate compared with PJ isolate and the sequence identity between two group reached to 72.0%-75.0%. Even though no base variation occurred in 5' terminal non-coding region, there was two bases substitution in 3' terminal non-coding region. These results showed that the isolates were grouped according to their geographical location. Additionally, highly consensus in 5' and 3' non-encoding region suggested that these regions played an very important role in transcription and replication of viral genome. Finally, the molecular epidemiology and gene functions of Rice stripe virus were discussed in this paper.

Amino Acid Sequence↗
PubMed2001

[Studies on the synthesis and bioactivity of alpha-alkylaminobenzyl-phosphonic acids].

AIM: To search for some substituted benzyl phosphonic acids as leading compounds with inhibiting effect on osteoclast formation. METHODS: Target compounds were prepared from aromatic aldehydes, primary amine and phosphorous acid using tetramethylenesulfone as solvent via Arbuzov type reaction. The effect on inhibiting the formation of osteoclast-like cells (OLC) of related compounds was studied by incubating the extract of rat femur marrow. RESULTS: Ten compounds of alpha-alkylaminobenzyl phosphonic acids have been synthesized and identified by MS or 1HNMR analysis. Three (2, 8 and 9) of them were found to have notable effect on the inhibition of OLC formation (P < 0.01). CONCLUSION: Among the present substituted benzyl phosphonic acids, the increased aromaticity and hydrophobicity (such as compound 9) can remarkably enhance the ability to inhibit OLC formation.

Animals↗
PubMed2001

[Spectrum studies on titania photocatalysts].

The nano-sized TiO2 photocatalysts were prepared by sol-gel method and characterized by FTIR spectroscopy, FT-Raman spectroscopy and diffuse reflectance spectroscopy(DRS). Photocatalytic degradation of oleic acid over the TiO2 catalysts was investigated. The result showed that calcination temperature has strong effect on crystal structure, energy band structure, optical adsorption and photocatalytic activity of the TiO2 catalysts. It was found that the TiO2 photocatalyst calcined at 400 degrees C has the best apparent optical adsorption, the biggest band edge position and the highest photoactivity. The effect of calcination temperature on photocatalytic activity of TiO2 catalysts has been ascribed to the changes in structure and optical property of catalyst such as crystal size, content of rutile, residual NO3-, and band-edge position of light adsorption.

Adsorption↗
PubMed2000

Truncation of the extracellular region abrogrates cell contact but retains the growth-suppressive activity of E-cadherin.

E-cadherin has been demonstrated to induce growth suppression and decrease the invasiveness of cancer cells and thus has been proposed to be a tumor suppressor gene. The ability of E-cadherin to mediate cell-cell contact and contact inhibition presumably accounts for its antitumor effects, which are attributed to the extracellular domain of the protein. Here we report that blocking the ability of E-cadherin to mediate contact inhibition by either antagonistic antibodies or expression of a mutant form of E-cadherin with the extracellular region deleted does not abrogate growth suppression. Transfection of the E-cadherin gene into the human prostate cancer cell line TSU.Pr-1 induced cell-cell contact formation, growth suppression, and redistribution of beta-catenin to the cell membrane. Treatment of the E-cadherin transfectant (CAD) with blocking antibodies disrupted cell-cell contact formation but did not influence the growth rate, suggesting that cell-cell interaction is not required for E-cadherin-mediated growth suppression. Similarly, transfection of an E-cadherin construct in which the NH2-terminal (extracellular) region was deleted did not allow cell-cell contact formation but induced growth suppression. In contrast, transfection of an E-cadherin construct in which the COOH-terminal (cytoplasmic) region was deleted did not induce suppression but promoted cell contact formation. In cells expressing E-cadherin lacking the cytoplasmic region, beta-catenin was evenly distributed in the cytoplasm. By contrast, in cells expressing E-cadherin lacking the extracellular region, beta-catenin was cell membrane associated. Growth suppression was always associated with the localization of beta-catenin to the cell membrane. The redistribution of beta-catenin from the cytoplasm to the cell membrane initially suggested the involvement of the Wnt signaling pathway in regulating cell growth. However, only small differences in beta-catenin/T-cell factor signaling were detected in control and E-cadherin-expressing cells, suggesting that the Wnt pathway is not involved. Taken together, these findings suggest that E-cadherin-induced growth inhibition may not be solely attributed to contact inhibition but may involve the redistribution of beta-catenin from the cytoplasm to the cell membrane, and this redistribution may affect growth pathways independent of T-cell factor.

Animals↗
PubMed2000

Apoptosis of Mo7e leukemia cells is associated with the cleavage of Bcl-2 into a shortened fragment that is not functional for heterodimerization with Bcl-2 and Bax.

Bcl-2 is an integral intracellular membrane protein that can protect cells from apoptosis induced by multiple insults in a variety of cell types. During apoptosis, Bcl-2 was cleaved into a shortened fragment (Bcl-2/Delta34) by a caspase-3-like protease in human Mo7e megakaryocytic leukemia cells deprived of exogenous rhGM-CSF. Results from cell fractionation and immunoblot analyses indicated that both Bcl-2 and Bcl-2/Delta34 were located exclusively on the mitochondria of Mo7e cells. Treatment of isolated mitochondria with recombinant caspase-3 induced the same cleavage of Bcl-2 in vitro and caused the release of cytochrome c from the mitochondria into the supernatant. The antiapoptotic effect of Bcl-2/Delta34 was investigated using an in vitro protein translation approach. Both Bcl-2/Delta34 and Bax proteins generated in wheat germ extract were readily relocated to the mitochondria isolated from control Mo7e cells. Insertion of Bax, but not Bcl-2/Delta34, into mitochondria triggered a rapid release of cytochrome c from the mitochondria. Coimmunoprecipitation studies showed that, unlike Bcl-2, the cleaved Bcl-2 fragment was no longer functional for dimerization with either Bcl-2 or Bax. Taken together, these findings showed that the integrity of Bcl-2 is necessary for its function of heterodimerization with Bax, which appears to be one of the mechanisms of antiapoptotic effect of Bcl-2.

Apoptosis↗
PubMed2000

A frequent deletion polymorphism on chromosome 22q13 identified by representational difference analysis of ovarian cancer.

Sizable homozygous deletions (>100 bp) of genomic DNA in cancer cells are typically interpreted as an indication of the location of a tumor suppressor gene. In an effort to identify novel ovarian growth-suppressing genes, we performed representational difference analysis (RDA) of ovarian cancer cells. One of the RDA probes identified a 276-bp region of chromosome 22q deleted in 47% of the ovarian cancer cell lines examined. This small deletion was also found in the genomic DNA of 25% of colon cancer cell lines examined and, surprisingly, in 18% of the blood DNA samples from healthy controls. The deleted allele, which was named u22q, has a frequency of approximately 50% in the population and is in Hardy-Weinberg equilibrium with the intact allele. The deleted DNA sequence is flanked by direct repeats and likely originated through a slipped mispairing mechanism. The deletion did not encompass known transcripts or expressed sequence tags. It therefore appears likely that u22q represents a common polymorphism, often hemizygous in ovarian cancer because of a high rate of LOH of chromosome 22q. These findings provide an example of a sizable homozygous deletion that does not appear to be associated with disease. Such a finding provides a cautionary tale for positional cloning projects initiated exclusively on the basis of the identification of homozygous deletions. The possibility that the deletions in question may be constitutive should always be considered since it is probable that the genome contains a large number deletions/insertions of various sizes.

Base Sequence↗