Biomedical subjects

S Lin

Publications and source records attributed to S Lin.

At least 217 records · Page 12Linked to original sources

PubMed1999

Abortifacient effects of a unique class of vasoactive lipids from Pinus ponderosa needles.

Pinus ponderosa needle (PN) ingestion by late pregnant cows results in decreased uterine blood flow, premature parturition, and retained placentae. Further, plasma from PN-fed cows increases caruncular arterial tone (i.e., induces prolonged contraction) in an isolated perfused bovine placentome. A novel class of vasoactive lipids was isolated and identified using a bovine placentome assay-guided fractionation of CH2Cl2 extracts of PN. Placentome perfusion tests indicated that 1-12-dodecanedioyl-dimyristate (14-12-14) was the most potent of the PN lipids for increasing caruncular arterial tone. Late pregnant guinea pigs (GP) were used to evaluate the abortifacient activity of these vasoactive lipids. In Study 1, on d 50 of gestation, part of the control diet was replaced with chopped PN (Diet A) or chopped PN subjected to sequential extraction with diethyl ether (Et2O; Diet B); Et2O and CH2Cl2 (Diet C); and Et2O, CH2Cl2, and methanol (Diet D). The GP on Diets A and B exhibited shorter (P<.01) gestation lengths and reduced (P<.01) pig birth weights than GP on the control diet or Diets C and D. Further, only GP on Diets A and B exhibited retained placentae. In Study 2, on d 50 of gestation, part of the control diet was replaced with chopped PN that had been subjected to exhaustive CH2Cl2 extraction and then infiltrated with either CH2Cl2 alone (Diet E), CH2Cl2 containing 14-12-14 (Diet F), or CH2Cl2 containing isocupressic acid (Diet G); then solvents were evaporated. The GP consuming Diet F had shorter (P<.05) gestation lengths and reduced (P<.05) pig birth weights than did GP consuming Diets E or G. The GP consuming Diet F also exhibited a high incidence of retained placentae. These data provide evidence that a unique class of vasoactive lipids in PN exhibit abortifacient activity in guinea pigs.

Abortifacient Agents↗

PubMed1999

Asthma hospitalization rates and socioeconomic status in New York State (1987-1993).

This study examined the geographic distribution of asthma hospitalizations in New York State (NYS) and its association with socioeconomic status. Statewide asthma hospitalization data (1987-1993) were merged with 1990 census data by residential zip code. The asthma hospitalization rate increased in NYS from 1987 (2.54 per 1000) through 1993 (2.87 per 1000) and the increase is largely attributable to increases for children 4 years old and younger. The risk factors for asthma admission varied in different areas. However, rates of hospitalization because of asthma were generally higher in the zip codes areas with higher proportions of poverty, unemployment, poorly educated residents, African-Americans, and Hispanics.

Adolescent↗

PubMed1999

[The relation between alpha1-antichymotrypsin gene polymorphism and epsilon4 allele of apolipoprotein E gene in Alzheimer disease in Chinese].

OBJECTIVE: To detect the relation between alpha1-antichymotrpsin(AACT)gene polymorphism and epsilon4 allele of apolipoprotein E (ApoE) gene in Alzheimer disease (AD) in Chinese. METHODS: The gene polymorphisms of ApoE and AACT were genotyped in 125 AD cases and 140 controls with PCR methods and RFLP typing. Then the association between AACT polymorphism and ApoE epsilon4 was analysed. RESULTS: There was no association between AD and any allele or genotype of AACT polymorphism; AACT polymorphism was not associated with AD ApoE epsilon4 or without ApoE epsilon4. In AACT*AT and AACT*TT genotypes, ApoE epsilon4 allele was associated with AD, but no association was observed in AACT*AA genotype. CONCLUSION: AACT may not be associated with AD in Chinese, and this effect can not be influenced by ApoE epsilon4, but AACT gene polymorphism may affect the association between ApoE epsilon4 allele and AD.

Adult↗

PubMed1999

An approach for high sensitivity detection of prostate cancer by analysis of changes in structuredness of the cytoplasmic matrix of lymphocytes specifically induced by PSA-ACT.

PURPOSE: An alternative procedure for detection of prostate cancer was examined based on the observation that cells reexposed in vitro to antigenic or mitogenic stimulation will change their intracellular structuredness as measured by polarization of fluorescent light emitted by labeled cells (SCM test). MATERIALS AND METHODS: Lymphocytes derived from patients bearing a nonmalignant prostate tumor and healthy individuals were exposed to PSA-ACT, PHA, and MUC-1. RESULTS: Of sixty-five patients with prostate carcinoma (CaP), sixty-two were correctly diagnosed by the test. Of the eighty males in the control group, five were incorrectly diagnosed as having the disease and seventy-five were correctly diagnosed as healthy subjects. The sensitivity of the test was 96.8%. The specificity was 91.1%. The BPH (Benign Prostatic Hyperplasia) control group exhibited a sensitivity of 9.38%, but the specificity was 91.1%. Similar percentages for specificity and sensitivity were observed in the NRT (Non-Relevant Tumor) control group. CONCLUSIONS: The results shown here indicate the possibility of a different use of PSA-ACT for detection of prostate cancer with high specificity and sensitivity.

Adult↗

PubMed1999

Recent advances in the medicinal chemistry of taxoids with novel beta-amino acid side chains.

Beta-Amino acids have been recognized as an important class of compounds in the design and synthesis of potential pharmaceutical drugs and also for the study of enzymatic reaction mechanisms. Among the beta-amino acid family, isoserines (alpha-hydroxy-beta-amino acids) are probably the most important members because many of them are potent enzyme inhibitors and they also serve as essential building blocks for biologically and medicinally important molecules such as Taxol. Taxol (paclitaxel) and Taxotère (docetaxel) are currently considered to be the most important drugs in cancer chemotherapy. This review describes recent advances in the chemistry of isoserines and taxoid anticancer agents at the biomedical interface including (i) the development of highly efficient method for the synthesis of isoserine side chains of taxoids and (ii) the synthesis and structure-activity relationship (SAR) study of taxoids featuring discovery and development of the "second generation" taxoid anticancer agents that possess exceptional activities against drug-resistant cancer cells.

Alkaloids↗

PubMed1999

[The profile of low bone mass in amenorrhea with elevated follicle stimulating hormone].

OBJECTIVE: To observe the characteristics of low bone mass in amenorrhea with elevated follicle stimulating hormone(FSH). METHODS: Amenorrhea patients with elevated FSH: primary amenorrhea (PA) 18 cases, secondary amenorrhea (SA), 171 cases and age matched control with normal menstruation (Nor) 180 cases. The descriptive parameters were: estradiol (E2), alkaline phosphatase (ALP), urinary excretion of calcium to creatinine ratio (Ca/Cr), the cortical bone mineral density (CBMD) at right radius measured by single photon absorptimetry (SPA) and the trabecular bone mineral density (TBMD) at lumbar vertebra body measured by quantitative computerized tomography (QCT). RESULTS: The experiment had shown the average E2 level in amenorrhea patients to be < 150 pmol/L. Significantly higher ALP and Ca/Cr values than the Nor group. In the SA group, the CBMD value was (655 +/- 69) mg/cm2, which was significantly lower than the Nor group's value of (677 +/- 56) mg/cm2 (3.2% lower, P < 0.01). The TBMD value is (145 +/- 26) mg/cm3, which is significantly lower than the Nor group's value of (192 +/- 28) mg/cm3 (24.5%, P < 0.001). The disparity with the Nor group was even greater in the PA group (11.1% and 35.7% lower, respectively). The BMD of the amenorrhea patients were negatively linearly correlated with their amenorrhea age. CONCLUSIONS: The serum estradiol level in amenorrhea patients with high FSH was so low that their bone turnover was increased which led to the insufficient bone accumulation and dramatically dropping of TBMD. Its extent was related to the initial age and the duration of ovarian failure.

Absorptiometry, Photon↗

PubMed1999

[Bilirubin induced apoptosis of cerebellar granule neurons].

OBJECTIVE: To investigate the mechanism of bilirubin-induced neurotoxicity from cellular and molecular level. METHODS: Bilirubin was exposed to primary cultured rat cerebellar granule and cortical neurons and its neurotoxicity was observed DNA staining and agars gel electrophores were used to identify the biochemical and morphological features of bilirubin-induced neurotoxicity in cultured cerebellar granule and cortical neurons. RESULTS: Bilirubin selectively induced death of cerebellar granule neurons in a concentration- and time-dependent manner. Neuronal death displayed biochemical and morphological features of apoptotic nuclei: condensation of nuclear chromatin and DNA fragmentation. RNA and protein synthesis inhibitors blocked the neurotoxicity induced by bilirubin. However, the cortical neurons displayed a relative insensitivity to bilirubin. CONCLUSIONS: Bilirubin induced neuron death is an active process, requiring de novo synthesis of RNA and protein. Bilirubin may selectively induce apoptosis of cerebellar granule neurons.

Animals↗

PubMed1999

[Gene expression of beta-adrenoceptor signal transmitters in heart failure].

OBJECTIVE: To investigate the alteration in steady-state levels of messenger RNA(mRNA) of beta-adrenoceptor signal transmitters in heart failure. METHODS: The reverse transcription polymerase chain reaction (RT-PCR) was used to assess gene expression in small quantity of circulatory lymphocytes. With selected oligonucleotide primers, we used quantitative RT-PCR to amplify mRNAs encoding beta 2-adrenergic receptor(beta 2-AR), adenylate cyclase (AC), beta 2-adrenergic receptor kinase(beta-ARK), and beta-arrestin and cAMP response element binding protein (CREB) in 16 healthy subjects and 30 heart-failing patients. RESULTS: The alteration of gene expression in heart failure appeared to be selective, the steady-state levels of mRNA increased significantly involving AC and the transcription factor, CREB; decreased significantly involving membrane receptor, beta 2-AR; unchanged significantly involving phosphorylating factors of beta-AR uncoupling, beta-ARK and beta-arrestin. CONCLUSION: The aberrant gene expression of beta-adrenergic receptor might play an important role in the pathogenesis of heart failure.

Adenylyl Cyclases↗

PubMed1999

[The association between microsatellite polymorphism of alpha 1-antichymotrypsin gene and Alzheimer's disease].

OBJECTIVES: To examine the relation between the microsatellite polymorphism of alpha 1-antichymotrypsin (AACT) gene and Alzheimer's disease (AD) in Han population of Shanghai area, and to detect the influences of apolipoprotein E (ApoE) gene epsilon 4 allele on this relation. METHODS: The polymorphism of AACT and ApoE gene were genotyped in 63 AD cases, 62 controls with amplified fragment length polymorphism typing (Amp-FLP). RESULTS: The frequencies of A6 and A10 alleles of the microsatellite polymorphism of AACT gene polymorphism were decreased markedly (ZA6 = 2.2357, ZA10 = 1.9668, P < 0.05), but only A6 allele was negatively associated with AD (RR = 0.4, chi 2 = 4.683, P < 0.05). When the data were split into ApoE * epsilon 4-positive and ApoE * epsilon 4-negative groups, the drop of AACT * A6 allele frequency was only associated with AD with non-ApoE epsilon 4 (RR = 0.29, chi 2 = 3.197, P < 0.05). CONCLUSION: AACT * A6 allele may be associated with AD negatively in Shanghai area, and this effect only exists in non-ApoE * epsilon 4 AD.

Aged↗

PubMed1999

[Genetic association between mood disorder and monoamine oxidase gene].

OBJECTIVE: To ascertain whether the mood disorder (bipolar and unipolar) is genetically associated with genes polymorphisms of MAOA type and MAOB type in the Chinese. METHODS: One hundred and thirty-two cases of Chinese with mood disorder were genotyped for the MAOA(CA)n, MAOB(GT)n and MAOB(TG)n locus using Amp-FLP. RESULTS: Among 132 cases with mood disorder, 8 alleles (size: 112-126 bp) of MAOA(CA)n, 12 alleles (size: 168-198 bp) of MOAB(GT)n and 9 alleles (size: 195-213 bp) of MAOB(TG)n locus were observed. Comparison of the polymorphisms of all alleles in the three locus showed that no significant difference (P > 0.05) was seen in the frequency distribution between cases with mood disorder (bipolar and unipolar) and controls, but the frequency of 180 bp allele for MAOB(GT)n and 250 bp allele for MAOB(TG)n was significantly different (P < 0.05) between the two groups. CONCLUSION: MAO gene (type A and B) is not associated with mood disorder in the Chinese.

Adult↗

PubMed1999

Messenger RNA expressions of vasopressin system and aquaporin-2 in adriamycin-induced nephrotic rats and effects of astragalus membranaceus.

OBJECTIVE: To investigate the expressions of hypothalamic arginine vasopressin (AVP) mRNA, renal AVP V2 receptor mRNA, and AVP-dependent aquaporin-2 (AQP2) mRNA in rats with adriamycin-induced nephrotic syndrome. Effects of Chinese herb Astragalus membranaceus (AM) were also tested. METHODS: Sprague-Dawley rats with four weeks of adriamycin-induced nephrotic syndrome (NS) were used in this study. Another group NS + AM was set to testify the effects of AM given 0.5 g/kg daily on NS. Hypothalamic AVP mRNA expression was examined by dot blot method. Reverse transcription polymerase chain reaction was applied for detection of renal cortical and medullary V2 receptor and AQP2 mRNA. The results were normalized by mRNA of glyceraldehyde-3-phosphate dehydrogenase from the same sample. RESULTS: All rats receiving adriamycin presented typical nephrosis. No obvious difference in plasma osmolality was detected among NS, NS + AM, and normal control (NC) rats. Hypothalamic AVP mRNA expression was higher in NS rats than NC (53.59 +/- 5.49 vs 25.72 +/- 1.96, P < 0.01). AM completely reversed this up-regulated expression (21.88 +/- 1.25). In both cortex and medulla of the kidney, nephrotic rat had increased AVP V2 expressions by 169% and 55%, respectively, compared with normal control rat. The increment of expression of AQP2 mRNA was consistent with that of V2 receptor in NS rat. AM could partially however significantly correct these up-regulations of V2 and AQP2 mRNA expressions (P < 0.01). CONCLUSION: The up-regulated mRNA expressions of hypothalamic AVP, renal V2 receptor and AQP2 might play a role in edema formation in adriamycin-induced nephrotic rats. AM exerts its therapeutical effects on nephrosis partially through this mechanism.

Animals↗

PubMed1999

[Clinical study on therapeutic mechanism of Sini Decoction in treating post-percutaneous transluminal coronary angioplasty ischemia-reperfusion injury in terms of syndrome typing of TCM].

OBJECTIVE: To study the mechanism of Sini Decoction (SND) in prevention and treatment of post-percutaneous transluminal coronary angioplasty (PTCA) ischemia-reperfusion injury with different Syndrome typing of TCM. METHODS: Forty patients received PTCA were randomly divided equally into the SND group and the control group, in each group, there were 10 of Excess Syndrome (ES) and 10 of Deficiency Syndrome (DS). Twenty-five ml of SND was given daily to the SND group from 3 days before operation to the third day after operation. The blood superoxide dismutase (SOD) activity, malondialdehyde (MDA) and nitric oxide (NO) content of patients were determined before PTCA, and 1 hrs, 12 hrs, 24 hrs, 48 hrs and 72 hrs after PTCA. RESULTS: Before PTCA, the cases of DS were characterized by low SOD activity and high MDA content, as compared with the patients of ES, P < 0.05. SND could relieve the post-PTCA deprivation of SOD activity and NO content and the elevation of MDA level of both ES and DS patients, the amplitude of elevation of SOD activity in DS patients was higher than that in ES patients (P < 0.05). CONCLUSION: SND has antagonisting effect on post-PTCA ischemia-reperfusion injury, which is more effective in treating patients with DS.

Angioplasty, Balloon, Coronary↗

PubMed1999

[Expression of type I transforming growth factor beta receptor in renal cortex in streptozotocin-induced diabetic rats and the regulation of benazepril].

OBJECTIVE: To study the expression of type I transforming growth factor beta receptor (TGFbetaRI) in renal cortex in streptozotocin-induced diabetic rats and the regulation of benazepril. METHODS: The rats were randomized to following groups: uninephrectomized rats (group C), streptozotocin diabetic rats (group D) and diabetic rats treated with benazepril (group DB). Blood glucose, serum creatinine, body weight, kidney weight and renal protein content as well as angiotensin-convertion enzyme (ACE) activity of plasma, and renal cortex and medulla were observed after 4 weeks of treatment. The expressions of TGFbetaR I mRNA, 1alpha (IV) precollagen, fibronectin (FN) mRNA and TGFbetaR I protein were measured by reverse transcription-polymerase chain reaction (RT-PCR), Northern blot and Western blot, respectively. RESULTS: Group DB had hyperglycemia, body weight loss, kidney hypertrophy and increased ACE activity in renal cortex despite a decrease in plasma ACE activity. These changes were associated with 1.12, 4.25, 1.50 and 1.10 fold increase in TGFbetaR I, 1alpha (IV) collagen, FN mRNA and TGFbetaR I protein expressions during a 4 week time course; Administration of benazepril could attenuate hyperglycemia, body weight loss and kidney hypertrophy, ACE activity in plasma and cortex was decreased by 92.00% and 88.77%, respectively, It also could reduce TGFbetaR I, 1alpha (IV) collagen, FN mRNA and TGFbetaR I protein by 63.89%, 61.90%, 45.83%, 52.13%, respectively. CONCLUSION: It is suggested that there is an interaction between TGFbetaR I and the pathogenesis of diabetic nephropathy. Benazepril can supress the expression of TGFbetaR I in renal cortex.

Angiotensin-Converting Enzyme Inhibitors↗

PubMed1999

[Renal protective effect of valsartan in diabetic rats].

OBJECTIVE: To investigate the mechanism of valsartan in protecting the renal lesion of diabetic rats. METHODS: The following groups of rats were studied: normal control rats, streptozotocin diabetic rats and diabetic rats treated with valsartan (8 mg x kg(-1) x d(-1)). Mean arterial pressure, plasma glucose, serum insulin, serum creatinine, urinary albumin, ACE activity and Ang II concentration of kidney as well as profile of kidney hypertrophy were observed after 2, 4, 8 weeks of treatment, while TGF beta(1) mRNA expression of kidney cortex was assessed by Northern blot analysis, TGF beta(1), fibronectin and collagen IV expression were measured by immunohistochemistry. RESULTS: Serum creatinine level (P < 0.05), urinary albumin excretion and kidney hypertrophy index (P < 0.01) of valsartan treated group were significantly lower than those of diabetic untreated group. There was a significant increase in mRNA expression of TGF beta(1) and protein expression of of TGF beta(1) fibronectin and collagen IV in diabetic rats (P < 0.01). The expression of TGF beta(1) mRNA and protein (P < 0.01) as well as the protein expression of fibronectin and collagen IV (P < 0.05) in the valsartan group were much lower than that in the diabetic group. CONCLUSION: The results suggested that valsartan has some renal protective effect on diabetes in rats, partly through down-regulating TGF beta(1) expression and reducing deposition of glomerular ECM.

Animals↗

PubMed1999

[Early use of Chinese drug rhodiola compound for patients with post-trauma and inflammation in prevention of ALI/ARDS].

OBJECTIVE: To evaluate the effects of the Chinese drug rhodiola on the preventive treatment of acute lung injury (ALI) caused by post-traumatic/inflammatory and thoracic-cardiovascular operations. METHODS: 104 patients who coincide with their diagnosis and standard scale were divided randomly in to single number groups A(1), B(1), C(1) and D(1) (early preventive treatment group EG) and double number groups A(2), B(2), C(2) and D(2) (control group CG). The treatment of primary disease both in EG and CG was similar, but in EG four grams of rhodiola compound (RCO) were used every day for a period of 3-15 days since admission and 5-7 days after operation. The indicators related to ALI in each groups were measured. RESULTS: PaO(2), AaDO(2) and hemorheology were significant in EG than in CG (P < 0.05) or (P < 0.01). The complication rate of ARDS was decreased about of 50.0% in EG than in CG. CONCLUSIONS: Early use of RCO may protect against major risk factors of ALI/ARDS caused by massive trauma/infection and thoracic-cardio-operations.

Adolescent↗

PubMed1999

[Protection against synergistic hepatocarcinogenesis of hepatitis B virus expression and aflatoxin B1 by antioxidant 2(3)-tert-4 -hydroxyanisole (BHA) in HBV large envelope transgenic mice].

OBJECTIVE: To investigate the effects of 2(3)-tert-4-hydroxyanisole (BHA) on protection against synergistic hepatocarcinogenesis of aflatoxin B(1) (AFB(1)) and hepatitis B virus (HBV) expression in HBV large envelope transgenic mice. METHODS: Protective effects of dietary antioxidant BHA on life span was observed in 49 cases of HBV transgenic mice and 48 cases of non-transgenic mice by determinations of enzyme activities and liver MDA, and by direct detection of liver oxidative free radicals (OFR) using electron spin resonance (ESR). RESULTS: In the HBV transgenic mice which exposed to AFB1, the incidence of hepatocellular adenoma was 17% (2/12), but no carcinoma was found in BHA group. In the regular diet group, that was greater with 67% (6/9) of adenoma and 22% (2/9) of carcinoma. BHA could decrease significantly the concentrations of liver MDA and OFR, compared with those with regular diet. The activities of quinone reductase and glutathione S-transferase in liver cytosols increased by 3 - 7 times, as in the controls, in response to BHA. CONCLUSIONS: Addition of BHA to the diet resulted in significantly elevation of phase II enzyme activities in liver. BHA could directly eliminate liver OFR and inhibit growth of hepatocellular altered foci. These actions may effectively put off hepatocellular carcinogenesis in mice.

Aflatoxin B1↗

PubMed1999

[Induction of quinone reductase and glutathion-s-transferase by dimethyl fumarate in rats].

OBJECTIVE: To assess induction of quinone reductase (QR) and glutathion-s-transferases (GSTs) by dimethyl fumarate (DMF) in major viscera of rats. METHODS: Fodder fed to male Wistar rats was supplemented with 2.0% DMF, and blood specimens were collected form the rats 6 h, 24 h, 72 h, 1 week and 2 weeks after feeding, respectively, and then animals were killed. QR and GSTs activities were determined in rats' gland stomach, liver, lung, kidney and heart, and also QR, LDH and GPT activities in their sera were measured with enzyme dynamic methods. RESULTS: Administration of DMF for 24 h, 72 h, 1 week and 2 weeks in rats can significantly increase activities of QR and GSTs in their gland stomach, liver, lung and kidney, as compared with those in controls (P < 0.0001, or P < 0.01), and their serum QR also significantly increased (P < 0.0001, or P < 0.01). But, DMF had no effect on activities of serum GPT and LDH (P > 0.05). CONCLUSION: DMF is a potent induction agent for QR and GSTs in the gland stomach, liver, lung and kidney of rats, which suggests it will hopefully be a protective and antidotic agent against human antioxidant injury.

Animals↗

PubMed1999

[Efficacy of native carvedilol in patients with essential hypertension].

To compare the efficacy of native carvedilol(Cv) with native atenolol(At), we treated 80 cases of essential hypertension(stage I-II) for 4 weeks, using both open-test and double blind randomized imitative methods. The daily dose of carvedilol was 10 mg to 40 mg, and that of atenolol was 50 mg to 100 mg. Both drugs were given once daily. Out of 30 cases of Cv group, carvedilol showed significant efficiency in 20 cases, and was effective in 6 cases. The total therapeutic efficiency was 86.2% (26/30). In the double blind groups(25 patients in each group), those treated with carvedilol(Group A) had 21 effective cases(84.0%) while those treated with atenolol(Group B) had 18 effective cases(72.0%). A lower incidence of adverse effects was observed in carvedilol group. Dizziness occurred similarly in both drugs, but it lasted only a short time and could be tolerated. The recommended dose of 10-30 mg once daily would be appropriate. After treatment there was a significant reduction in blood pressure in both groups(P < 0.01). It suggests that native carvedilol is a safe and effective anti-hypertensive agent.

Adolescent↗