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S Li

Publications and source records attributed to S Li.

At least 685 records · Page 38Linked to original sources

Differential involvement of adrenal and gonadal steroids in anterior and intermediate pituitary pro-opiomelanocortin mRNA expression induced by the endogenous benzodiazepine, octadecaneuropeptide, in adult male rats.

The involvement of the endogenous benzodiazepine, octadecaneuropeptide (ODN), in the regulation of proopiomelanocortin (POMC) mRNA expression at the pituitary level, and the influence of adrenal and gonadal steroids, have been studied using a quantitative in situ hybridization technique. I.c.v. injection of ODN (4 micrograms/kg) in sham-operated rats induced a 17 and 7% decrease in the POMC mRNA expression in anterior and intermediate pituitary lobes respectively. To determine the reciprocal involvement of adrenal and gonadal steroids in this regulation, animals were adrenalectomized and/or castrated. Adrenalectomy significantly increased POMC mRNA expression by 48% at the anterior pituitary level, but induced a 10% decrease of hybridization signal at the intermediate pituitary lobe (vs control sham-operated). Adrenal ablation reversed the effect induced by ODN and increased POMC mRNA expression at the anterior and intermediate pituitary levels by 60 and 10% respectively, compared with control sham-operated. By contrast, castration, which produced a decrease in POMC mRNA in the anterior pituitary and an increase in the intermediate lobe, did not modify the negative influence of ODN observed in sham-operated animals. When rats were adrenalectomized and castrated, the adrenalectomy influence was predominant at the anterior pituitary level, since ODN increased significantly the hybridization signal (+68% vs control sham-operated), while the castration influence was predominant at the intermediate pituitary level, since ODN induced an 11% decrease in POMC mRNA signal compared with control sham-operated. These studies indicate that, in vivo, the decrease in POMC mRNA expression in the anterior and intermediate pituitary induced by an endogenous benzodiazepine is differently modulated by adrenal and gonadal steroids, with a predominant influence of adrenal steroids at the anterior pituitary level and gonadal steroids at the intermediate pituitary level.

Adrenal Cortex Hormones↗

Social environment and year of birth influence type 1 diabetes risk for African-American and Latino children.

OBJECTIVE: Credible epidemiological data, primarily from European-origin populations, indicate that environmental factors play an important role in the incidence of type 1 diabetes. RESEARCH DESIGN AND METHODS: A population-based registry of incident cases of type 1 diabetes among African-American and Latino children in Chicago was used to explore the influence of individual and neighborhood characteristics on diabetes risk. New cases of insulin-treated diabetes in African-American and Latino Chicagoans aged 0-17 years for 1985-1990 (n = 400) were assigned to one of 77 community areas based on street address. Census tables provided denominators, median household income, percentage of adults > or = 25 years old who had completed high school and college, and a crowding variable for each community area individual-level data were birth cohort, sex, and ethnicity. Outcomes in Poisson regression were sex-, ethnic-, and birth cohort-specific incidence rates. RESULTS: Significant univariate associations between diabetes risk and ethnicity, birth cohort, crowding, and the percentage of adults in each community area who had completed high school and college were observed. African-Americans had a relative risk (RR) of 1.42 (95% CI, 1.14-1.76) compared with Latinos. Risk varied significantly by birth cohort in both ethnic groups. For every 10% increase in the proportion of adults who completed college, the RR for diabetes increased by 25% (RR, 1.25 [95% CI, 1.09-1.44]). Social class variables were significant determinants of risk for African Americans, but not for Latinos. CONCLUSIONS: The strong birth cohort and social class associations observed in this study implicate an infectious exposure linked with age.

Adolescent↗

Spurious elevation of automated platelet counts in secondary acute monocytic leukemia associated with tumor lysis syndrome.

The intent of this article is to describe the effect of tumor lysis on automated platelet counts in therapy-related, secondary acute monocytic leukemia. The first patient was a 69-year-old man with large cell carcinoma of the lung who developed acute monocytic leukemia 1(1/2) years after initiation of radiation and chemotherapy for his carcinoma. The second patient was a 72-year-old female with peripheral T-cell lymphoma who developed acute monocytic leukemia 1 year after initiation of chemotherapy for her lymphoma. Platelet counts were determined by the automated Coulter (STKS) counter. Both patients had clinical and laboratory evidences of tumor lysis syndrome and disseminated intravascular coagulation. The peripheral blood smears revealed numerous fragments of leukemic cells and apoptotic cells with pyknotic nuclei. The Coulter machine enumerated these cellular fragments as platelets, resulting in falsely elevated platelet counts. Awareness of this laboratory artifact in secondary acute monocytic leukemia with tumor lysis syndrome is important so that potential life-threatening thrombocytopenia is not overlooked.

Aged↗

New methods for determining the enantiomeric purity of erythro -sphingosine.

The enantiomeric purity of erythro -sphingosine samples can be determined simply, reliably, and accurately from 1H or 19F nuclear magnetic resonance spectra of the alpha-methoxy-alpha-(trifluoromethyl)phenylacetate (MTPA) derivative. As little as 0.1% of the minor enantiomer could be observed in a 1-mg sample, and detection limits of 1% and 5% were estimated for samples of 100 microg and 10 microg. The two threo -sphingosine enantiomers and four dihydrosphingosine stereoisomers were also differentiated by this technique, which served as an effective method for assessing the purity of sphingosine and dihydrosphingosine samples. Enantiomeric and diastereomeric purities could also be determined by normal-phase high performance liquid chromatographic analysis of the MTPA derivatives.

Animals↗

Retinoid kinetics in eye tissues of VPP transgenic mice and their normal littermates.

PURPOSE: VPP mice, which possess a mutant transgene for opsin (V20G, P23H, P27L), exhibit a progressive rod degeneration that resembles one form of human autosomal dominant retinitis pigmentosa. In the present study the association of the development of VPP rod degeneration with abnormal operation of the retinoid visual cycle was examined. METHODS: Dark-adapted VPP mice and normal littermates were anesthetized and the pupils dilated. One eye of each animal was illuminated for 2 minutes; the other eye was shielded from the light and served as a control. Each animal was then dark adapted for a defined period (0-300 minutes) and killed. Retinoids contained in the retina, retinal pigment epithelium (RPE), and extracellular medium were recovered by means of formaldehyde-, isopropanol- and ethanol-based extractions and analyzed by high-performance liquid chromatography. RESULTS: Total amounts of retinoid recovered from unilluminated eyes of 2-month-old normal and VPP mice were 425 +/- 90 picomoles per eye and 115 +/- 33 picomoles per eye, respectively (mean +/- SD). Relative distributions of retinoids within normal and VPP eyes were similar. In normal and VPP animals, illumination for 2 minutes produced a similar immediate reduction in the molar percent of total retinoid represented by 11-cis retinal in the retina (average reduction of 34% and 28% in normal and VPP animals, respectively) and a similar transient increase of all-trans retinal in the retina. In both groups the decline of all-trans retinal was accompanied by an increase in total retinyl ester. In normal and VPP animals, a period of approximately 40 minutes or more preceded initiation of the recovery of 11-cis retinal in the retina, and the time course of this recovery was generally similar to that for the decline of retinyl ester. The overall dark-adaptation period required for half-completion of 11-cis retinal recovery was approximately 150 minutes. In neither group did illumination produce a substantial peak of all-trans retinol in the retina. CONCLUSIONS: The evident approximately fourfold reduction of total retinoid in the eyes of 2-month-old VPP mice is consistent with histologic and electroretinographic abnormalities determined in previous studies. Despite this marked abnormality in retinoid content, retinoid cycling in the VPP is remarkably similar to that in normal littermates. The data place constraints on the functional consequences of any abnormality in retinoid processing that may be present at this stage of the VPP rod degeneration.

Animals↗

Self-administered joint counts and standard joint counts in the assessment of rheumatoid arthritis. MIRA Trial Group. Minocycline in RA.

OBJECTIVE: To determine the comparability of a text to a mannequin format for the assessment of joint counts (JC) among patients with rheumatoid arthritis (RA) participating in a randomized clinical trial (RCT). METHODS: A subgroup of patients participating in the MIRA (Minocycline in RA) RCT completed self-administered JC and joint scores (JS), which were compared to those of a trained assessor. RESULTS: JC and JS data were consistently higher for the patient than for the assessor. Higher correlations were obtained for JC than for JS. CONCLUSION: Our data suggest JC can be used in the context of clinical trials or in the clinical setting, but are not interchangeable with trained assessor JC.

Anti-Bacterial Agents↗

Examining the obstructed ureter with intraluminal sonography.

PURPOSE: Intraluminal sonography was used to define, differentiate and direct better treatment of obstructing ureteral lesions. MATERIALS AND METHODS: A total of 63 patients with a history of ureteral obstruction and suspected stricture were accrued for evaluation. All patients underwent retrograde contrast imaging, ureteroscopy and intraluminal sonography as part of a diagnostic algorithm. Specific sonographic criteria to differentiate lesions and stricture types were developed. Associated complicating variables defined on sonography included foreign bodies, submucosal stone fragments, ureteral wall fibrosis, mass lesions and adjacent vasculature. Endoscopic treatment was then performed with ultrasound guidance if technically feasible. RESULTS: A total of 63 ureters were evaluated with the preoperative diagnosis of ureteral stricture disease. All ureters were narrowed on contrast imaging in the segment where a stricture was suspected. On sonography 24 ureters (36%) had wall fibrosis with normal periureteral tissues. In general these strictures did well with endoscopic incision. Of the 67 ureters 13 (19%) were thickened or had edematous walls with normal architecture and without fibrosis. These patients all did well with expectant therapy. In contrast, 7 ureters (10%) were obstructed by segmental retroperitoneal fibrosis which did not respond to minimally invasive therapies. In addition, 8 ureters (12%) were obstructed by ureteral wall scarring and periureteral fibrosis, and required open surgical intervention. Ten ureteral strictures had adjacent vasculature, and endoscopic incisions under ultrasound guidance were directed safely away from these structures without associated morbidity. Calculi, stone fragments and foreign bodies embedded in the ureteral wall with associated inflammation were defined with sonography and responded to endoscopic therapies. The intraluminal sonographic diagnosis of ureteral endometriosis was made in 6 patients with a range of lesions from bright, hyperechoic blood filled cysts to an inhomogeneous fluid filled scar involving the wall and periureteral tissues. Primary ureteral carcinoma was also demonstrated in 2 patients after other diagnostic techniques failed. In 1 of these patients intraluminal sonography directed biopsies diagnosed submucosal tumor. Finally, 1 patient had a small periureteral urinoma on intraluminal sonography which was missed on other imaging studies. CONCLUSIONS: Intraluminal sonography is useful in patients with ureteral obstruction of unclear etiology as well as for selecting patients who may benefit from minimally invasive therapies and safely directing these treatments.

Adolescent↗

[Analysis of fusion points in hybrid genes and gene deletion for congenital red-green color vision defects].

OBJECTIVE: To investigate gene deletion and the fusion points of hybrid genes in congenital red-green color vision defects. METHODS: Genomic DNA was collected from 11 protans, 19 deutans and 5 normal controls. Promoter and exons 2-5 of the red and green pigment genes in these subjects were analyzed by using PCR-Heteroduplex-SSCP analysis. The origin and component of each individual gene were determined by comparison with the patterns of known sequence of the red and green visual pigment genes. RESULTS: Fourteen out of the 30 patients with red-green color vision defects were found to have hybrid gene. The fusion points of the hybrid gene were located in exon 1-intron 1(4 cases), introns 2-3(5 cases) and intron 4 (5 cases). CONCLUSION: The fusion point of a hybrid gene may occur in exon 1-intron 1 and intron 4 as well as in introns 2-3(including exon 3).

Artificial Gene Fusion↗

In vitro and in vivo studies of the effect of a Chinese herb medicine on osteoclastic bone resorption.

OBJECTIVE: To study the effect of a Chinese herb on osteoclastic bone resorption and osteoporosis. MATERIALS AND METHODS: Osteoclasts were isolated and cultured for in vitro study of the effect of the Chinese herb Guizhou epimedium (Epimedium Leptorrhizum Stearn). The in vivo effect of this Chinese herb was also investigated in rats in whom osteoporosis was induced by ovariectomy; these results were then compared with the effects of estradiol in the same group of rats. RESULTS: The in vitro study showed that the epimedium inhibited the osteoclastic resorption of bone. The in vivo investigation demonstrated that both the epimedium and estradiol were able to increase mineral content and promote bone formation. CONCLUSION: The Chinese herb Guizhou epimedium is of potential use in the treatment of osteoporosis.

Animals↗

Superoxide generation in v-Ha-ras-transduced human keratinocyte HaCaT cells.

The oncogenic ras protein controls signal-transduction pathways that are critical for cell proliferation and tumorigenesis. Here, we demonstrate that v-Ha-ras-transduced human keratinocyte HaCaT cells produced significantly larger amounts of superoxide than did control cell lines. The superoxide generation was mediated by the transduced ras protein, because superoxide generation was modified by an inhibitor, lovastatin, that inhibits ras farnesylation during ras protein maturation. Superoxide generation was also inhibited by diphenylene iodonium, an inhibitor of flavoproteins, including NADPH oxidase, but not by rotenone, an inhibitor of the respiratory chain of the mitochondria. Those observations suggested that a phagocytic-like NADPH oxidase exists in keratinocytes that could be activated by the dominant activated v-Ha-ras and produce superoxide. Overexpression of manganese-containing superoxide dismutase and copper and zinc-containing superoxide dismutase cDNA via adenovirus infection also attenuated superoxide generation. Previous work has demonstrated that extracellular superoxide dismutase (SOD) can lower superoxide generation; this is the first report that intracellular SOD could also modify the amount of superoxide production from the cells. This report implies that superoxide radical may act as a second messenger molecule of oncogenic ras.

Cell Line, Transformed↗

[Taurine inhibits deposition of extracellular matrix in experimental liver fibrosis in rats].

OBJECTIVE: To study the effect of taurine on liver fibrosis and its mechanism. METHODS: Fibrosis was induced by the administration of carbon tertrachloride(CCl4) in rats. Some of the animals were treated with taurine. The rats were killed after 12 weeks of CCl4 treatment. Depositions of type I, III and IV collages, laminin and hyaluronic acid were studied in liver sections by immunohistochemical technique using specific antibody. The hepatic contents of type I, III procollage and tissue inhibitor of metalloproteinase-1(TIMP-1) mRNA were determined by Northern blot hybridization. RESULTS: A significant elevations of hepatic collagen I, III, IV, laminin and hyaluronic acid were observed after 12 weeks of liver injury in animals without taurine treatment, and a definite increase in the amounts of hepatic type I, III procollagen and TIMP-1 mRNA was noted. Taurine prevented increases in type I, III procollagen mRNA expression as well as the accumulation of the collagens, laminin and hyaluronic acid in the liver. CONCLUSION: The data indicate that taurine has a protective effect in CCl4-induced hepatic fibrosis. The results suggest taurine might be of potential value in clinical practice.

Animals↗

New buccinator myomucosal island flap: anatomic study and clinical application.

The authors studied the vascular anatomy of the buccinator muscle by dissecting fresh cadavers. The anatomy of the buccal branches of the facial artery consistently confirmed the existence of a posterior buccal branch, a few inferior buccal branches, and anterior buccal branches to the posterior, inferior, and anterior portions of the buccinator. The buccal artery and posterior buccal branch anastomose to each other and ramify over the muscle. Several veins originate from the lateral aspect of the muscle, converge into the buccal venous plexus, and drain into the facial vein (from two to four tributaries) or into the pterygoid plexus and the internal maxillary vein (from the buccal vein). These vessels and nerves enter the posterior half of the buccinator posterolaterally. The facial artery and vein are located at variable distances from each other around the oral commissure and the nasal base. Two patterns of buccinator musculomucosal island flaps supplied by these buccal arterial branches are proposed in this article. The buccal musculomucosal neurovascular island flap (posteriorly based), supplied by the buccal artery, its posterior buccal branch, and the long buccal nerve, can be passed through a tunnel under the pterygomandibular ligament for closure of mucosal defects in the palate, pharyngeal sites, the alveolus, and the floor of the mouth. The buccal musculomucosal reversed-flow arterial island flap (superiorly based), supplied by the distal portion of the facial artery through the anterior buccal branches, can be used to close mucosal defects in the anterior hard palate, alveolus, maxillary antrum, nasal floor and septum, lip, and orbit. The authors have used the flaps in 12 patients. There has been no flap necrosis, and results have been satisfactory, both aesthetically and functionally.

Adult↗

[Case-control studies on risk factors for pulmonary tuberculosis in servicemen of China].

OBJECTIVE: To study the risk factors for pulmonary tuberculosis (PTB) in the servicemen of armed forces and lay a basis for its prevention and control. METHODS: A 1:2 matched case-control study was carried cut in the servicemen, with 86 cases and 153 controls. Data were analyzed with conditional logistic regression with EGRET software. Odds ratios (ORs) were calculated for the relevant factors. RESULTS: Single-variable analysis showed that schooling, history of exposure to PTB, history of Bacille Calmette-Guérin (BCG) vaccination and BCG vaccination scar all associated with the incidence of PTB, with ORs of 2.19, 2.03, 0.38 and 0.54, respectively, and P < 0.05. Multiple logistic regression analysis showed that BCG vaccination scar, history of exposure to PTB and schooling all entered the final regression model, with ORs of 0.36, 1.94 and 2.33, respectively. CONCLUSION: It suggested that BCG vaccination could play a role in the prevention of TB in the servicemen, and history of exposure to PTB was a potential risk factor for TB as well.

Adult↗

Urinary isoflavonoid and lignan excretion on a Western diet: relation to soy, vegetable, and fruit intake.

Dietary isoflavone and lignan phytoestrogens are potential chemopreventive agents. This has led to a need to monitor exposure to these compounds in human populations and to determine which components of a mixed diet contribute to the exposure. Typically, urinary isoflavonoid excretion is associated with soy consumption and that of lignans is associated with whole grains. However, other plant foods are known to contain phytoestrogen precursors. The purpose of this study was to examine the association between urinary isoflavonoid and lignan excretion and intakes of vegetables and fruits (V&F). Isoflavonoids (genistein, daidzein, O-desmethylangolensin, and equol) and lignans (enterolactone, enterodiol, and matairesinol) were measured in urine collected for 3 days from 49 male and 49 female volunteers (age, 18-37 years) reporting a wide range of habitual V&F intakes. Dietary intakes were assessed using 5-day diet records and a food frequency questionnaire. V&F groupings (total V&F, total V, total F, soyfoods, and V&F grouped by botanical families) were used to assess the relationship between V&F intake and urinary isoflavonoid and lignan excretion. Pearson correlations were performed. Intake of soyfoods was correlated significantly with urinary genistein (r = 0.40; P = 0.0001), O-desmethylangolensin (r = 0.37; P = 0.0002), daidzein (r = 034; P = 0.0007), and the sum of isoflavonoids (r = 0.39; P = 0.0001). There was no association between equol excretion and soy intake or between the isoflavonoids and any other V&F groupings. In addition, isoflavonoid excretion was correlated positively with intake of high-fat and processed meats, particularly among men who did not consume soy. This suggests that, even in the United States, on a Western diet, soyfoods are the primary contributors to isoflavone intake; however, additional "hidden sources" of soy may also contribute to exposure. In contrast, a variety of fiber-containing foods contributed to lignan excretion; the sum of the urinary lignans, enterodiol, enterolactone, and matairesinol, was associated with intake of total F (r = 0.27; P = 0.008), total V&F (r = 0.25; P = 0.01), soyfoods (r = 0.28; P = 0.006), and dietary fiber (r = 0.36; P = 0.0003). Overall, urinary phytoestrogens (isoflavonoids + lignans) were significantly higher in "high" compared with "low" V&F consumers. Compared with the "low" V&F group, the "high" group consumed diets that were, on average, higher in fiber and carbohydrate and soyfoods and lower in fat; thus, the urinary phytoestrogens may also be a useful marker of healthier dietary patterns.

Adolescent↗

Tentative association of the serotonin transporter with schizophrenia and unipolar depression but not with bipolar disorder in Han Chinese.

The serotonin transporter gene (SERT) plays an important role in the serotonin uptake into neurons. Recently, several polymorphisms including a variable-number-tandem-repeat (VNTR) in the second intron and an insertion/deletion polymorphism (5-HTT linked polymorphic region, 5-HTTLPR) were identified and reported to be associated with a variety of mental illnesses, including major depression, bipolar disorder, anxiety-related traits, and autism. In our study, we performed an association study between the SERT VNTR polymorphism and schizophrenia (n = 260), bipolar disorder (n = 137), and unipolar depression (n = 33) in the Han Chinese. A large group of ethnically matched control individuals (n = 362) were also genotyped. Allele 12 of the VNTR polymorphism was associated with schizophrenia (P = 0.007) and unipolar depression (P = 0.011). Bipolar disorder was not associated with the VNTR (P = 0.93). Thus, we conclude that the SERT VNTR polymorphism may be a risk factor for both schizophrenia and unipolar depression, but not for bipolar disorder, in the Han Chinese.

Alleles↗

A double blind observation for therapeutic effects of the tong luo kai bi tablets on rheumatoid arthritis.

The therapeutic effects of the Tong Luo Kai Bi Tablets [symbol: see text] in 120 patients with rheumatoid arthritis were observed in this clinical trial by the randomized double blind method. Both the observed group and the control group each had 60 patients. In the observed group treated with the Tong Luo Kai Bi Tablets, 1 case (1.7%) was cured clinically, 27 cases (45.0%) improved markedly, 26 cases (43.3%) improved, with a total effective rate of 90.0%. In the control group treated with Rheumatic Semen Strychni Tablets [symbol: see text], no case was cured, 16 cases (26.7%) improved markedly, 33 cases (55.0%) improved, with a total effective rate of 81.7%. Statistical data showed the Tong Luo Kai Bi Tablets had much better therapeutic effectiveness clinically than the Rheumatic Semen Strychni Tablets (P < 0.05).

Adult↗

[Expression of endothelin-1 and endothelin-1 mRNA in placental villus of pregnancy induced hypertension and the changes of plasma endothelin-1].

OBJECTIVE: To investigate the role of endothelin (ET-1) in the pathogenesis of pregnancy induced hypertension (PIH). METHODS: In 70 cases of PIH the plasma concentration of ET-1 was measured by RIA, and the expressions of ET-1 and its mRNA in placental villus were determined by immunohistochemistry and in situ hybridization respectively. 30 normal pregnant women (NP) served as control group. RESULTS: (1) The Plasma concentration of ET-1 was significantly higher in PIH than that in NP. There was a positive correlation between the plasma ET-1 level and mean arterial pressure in PIH. (2) The expressions of ET-1 and ET-1 mRNA were found in syncytiotrophoblast of placental villus and in the endothelium of fetal vessels. These positive signals were higher in PIH than in NP. CONCLUSION: The injury of endothelium of fetal and placental blood vessels was one of the causes of PIH. The placenta may play an important role in the pathogenesis of PIH.

Adult↗