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Biomedical subjects

J Yu

Publications and source records attributed to J Yu.

At least 397 records · Page 22Linked to original sources
PubMed1999

Drinking-driving and riding with drunk drivers among young adults: an analysis of reciprocal effects.

OBJECTIVE: This research attempts to test the hypothesis that a reciprocal relationship exists between drinking-driving (DD) and riding with drunk drivers (RWDD) among youth. METHOD: Analyses were performed on data from the 1996 New York State Youth Alcohol Survey. The sample is composed of 16- to 24-year-olds who used alcohol and drove automobiles (N = 993). LISREL software was employed to examine the hypothesized simultaneous system between drinking-driving and riding with drunk drivers. Alcohol use, driving patterns and perception of negative consequences of drinking-driving behavior were included as independent variables. RESULTS: The reciprocity between drinking-driving and riding with drunk drivers is composed of a relatively strong positive effect of DD on RWDD and a minimal effect of RWDD on DD. Alcohol use has a consistent effect on both drinking-driving and riding with drunk drivers. Frequency of weekend driving tends to increase the likelihood of drinking-driving, but not riding with drunk drivers. Youths' perceived likelihood of being arrested if caught drinking-driving appears to have a moderate negative association with drinking-driving and riding with drunk drivers for underage youths. CONCLUSIONS: The simultaneous system between drinking-driving and riding with drunk drivers tends to be dominated by the effect of the former on the latter. Involvement in drinking-driving among youths is likely to increase the chance of riding with drunk drivers, whereas involvement in RWDD may not necessarily increase the chance of DD. Possible explanations for this finding are discussed. Future research may focus on measurement errors of drinking-driving and riding with drunk drivers to further examine the relationship between these behaviors.

Adolescent↗
PubMed1999

Metabolism of antitumor hydroxymethylacylfulvene by rat liver cytosol.

Acylfulvenes are a potent class of antitumor agents derived from illudin S, a fungal sesquiterpene. Illudin S possesses antitumor activity but has a poor therapeutic index. Acylfulvene is 100-fold less toxic against human lung adenocarcinoma cells than illudin S, but inhibits tumor growth in human xenografts, opposite to illudin S. An analog of acylfulvene, MGI 114 (hydroxymethylacylfulvene), shows much greater efficacy, producing complete tumor regression in xenograft models. MGI 114 is currently in phase II clinical trials. Cytotoxicity of MGI 114, like that of illudin S, is believed to involve both chemical reaction and enzymatic reduction. Enzymatic reduction by a cytosolic NADPH-dependent enzyme (from rat liver) produced an aromatic metabolite similar to that formed from illudin S. However, the reaction occurred more slowly. In addition, four new metabolites were isolated, two hydroxylated derivatives and two in which the primary allylic hydroxyl was replaced by hydride. All retained the reactive centers of the parent MGI 114.

Animals↗
PubMed1999

Magnetic resonance imaging. Application to family practice.

OBJECTIVE: To review indications, contraindications, and risks of using magnetic resonance imaging (MRI) in order to help primary care physicians refer patients appropriately for MRI, screen for contraindications to using MRI, and educate patients about MRI. QUALITY OF EVIDENCE: Recommendations are based on classic textbooks, the policies of our MRI group, and a literature search using MEDLINE with the MeSH headings magnetic resonance imaging, brain, musculoskeletal, and spine. The search was limited to human, English-language, and review articles. Evidence in favour of using MRI for imaging the head, spine, and joints is well established. For cardiac, abdominal, and pelvic conditions, MRI has been shown useful for certain indications, usually to complement other modalities. MAIN MESSAGE: For demonstrating soft tissue conditions, MRI is better than computed tomography (CT), but CT shows bone and acute bleeding better. Therefore, patients with trauma or suspected intracranial bleeding should have CT. Tumours, congenital abnormalities, vascular structures, and the cervical or thoracic spine show better on MRI. Either modality can be used for lower back pain. Cardiac, abdominal, and pelvic abnormalities should be imaged with ultrasound or CT before MRI. Contraindications for MRI are mainly metallic implants or shrapnel, severe claustrophobia, or obesity. CONCLUSIONS: With the increasing availability of MRI scanners in Canada, better understanding of the indications, contraindications, and risks will be helpful for family physicians and their patients.

Adult↗
PubMed1999

Evidence for an inactive transposable mariner-like element in Anopheles albimanus.

Transposable elements may eventually be used as transformation vectors of anti-Plasmodium genes in natural populations of Anopheles mosquitoes. The mariner transposable element is widespread in most animal phyla and we wished to test for its presence in the important Latin American malaria vector, Anopheles albimanus. Degenerate primers were designed from the consensus of insect mariner elements and used in a polymerase chain reaction to amplify a fragment of the predicted size from An. albimanus. The fragment was cloned, sequenced, and determined to be a mariner-like element through multiple alignment with known insect mariner elements. Dot blot and Southern blot analyses showed only one or a few elements per haploid genome. The cloned fragment was used as a probe to isolate similar sequences from an An. albimanus genomic DNA library. A 659-base-pair clone was 57% similar at the DNA level with mariner elements from Anopheles gambiae, Chrysoperla ptorapunda, and Haematobia irritans. This low sequence similarity is comparable to that found among mariner-like elements in all insects. However, conserved amino acid motifs were not discovered nor was a single open reading frame found. These aspects suggest that the An. albimanus mariner-like element may represent an ancient transposition event but that the element is no longer active, the typical open reading frame having been disrupted through nucleotide insertions and deletions.

Animals↗
PubMed1999

[Study on endothlin and its gene expression in splanchnic vessels in cirrhotic rats].

OBJECTIVE: To investigate the role of endothelin(ET) in the pathogenesis of portal hypertension, ET-1 level and its gene expression in splanchnic vessels from cirrhotic rats were observed. METHODS: ET levels of both plasma and vascular tissues were determined by radioimmunoassay. ET mRNA in vascular tissues was probed with RT-PCR technique expressed as optical density(OD) value from image analysis. RESULTS: ET peptide and mRNA in PV and SMA vessels were all significantly higher in cirrhotic rats than those in normal rats, while in cirrhotic rats, ET and its gene expression of PV was dramatically higher than that of SMA(P < 0.05). In addition, the positive correlation was observed in difference between PV and SMA in ET concentration with portal pressure(r = 0.737, P < 0.01). CONCLUSION: ET may be involved in the mechanisms of the formation of portal hypertension mainly due to constructing portal vein, increasing portal flow resistance.

Animals↗
PubMed1999

[Inhibited effect of phosphorylated insulin-like growth factor binding protein-1 on hepatoma cells in vitro].

OBJECTIVE: To elucidate the inhibited effect and regulated mechanism of IGFBp-1 on the carcinoma cells. METHODS: The recombinant human IGF II (rhIGF II), phosphorylated and nonphosphorylated binding protein-1(pBp-1 and npBp-1) that were purified from pregnant woman's amnoitic fluid were used to cultivate cancer cells from 15 cases with hepatocellular carcinoma and ascites. The cell counting and MTT methods were used for determining the dynamics change of proliferation on HCC, and the in situ or dot hybridization with Digoxin label used for the expression of IGF II mRNA qualitatively and quantitatively at different times. RESULTS: The cells grew more slowly, in pBp-1 group, than in control group at the same time, which began to decrease at two days(P < 0.05) by MTT. In situ hybridization showed that there are hybridization signal of IGF II mRNA in all groups during the culture, and scanning dot hybridization showed the OPTMD of IGF II mRNA in pBp-1 group was statistically different from control and other groups (P < 0.01), while in npBp-1 group there was no significant effect compared with other groups (P > 0.05). CONCLUSION: The pBp-1 can inhibit the growth of hepatoma cells and the expression of IGF II mRNA, which may be regulated and inhibited by pBp-1.

Aged↗
PubMed1999

Influence of FL on ex vivo expansion of hematopoietic cells from cord blood in long-term liquid cultures.

The use of umbilical cord blood for stem cell transplantation has numerous advantages, but a major deficiency is the rather low cell number available. Therefore, ex vivo expansion were proposed to overcome this limitation. In this paper the effects of flt-3 ligand (FL), stem cell factor (SCF), interleukin(IL)-3, IL-6, granulocyte colony-stimulating factor (G-CSF) and granulocyte- monocyte colony-stimulating factor (GM-CSF) on long-term ex vivo expansion and differentiation of cord blood hematopoietic cells were investigated. In the culture containing FL + SCF + G-CSF + GM-CSF, the total cell expansion ratio reached the maximum (385.30 +/- 163.51-fold) at 28 days, whereas in the culture with FL + SCF + IL-3 + IL-6, CFU-GMs expansion ratio reached a plateau (409.52 +/- 189.50-fold) at 28 days. FL synergized with SCF and other cytokines. In all the conditions investigated, cultures with FL obtained an increase of fold expansion in both total cells and CFU-GMs. The combination of FL + SCF does not benefit the proliferation of the total cells, however, the expansion of CFU-GM was kept at a high level. Apparently, both cytokines maintained the activities of stem/progenitor cells and hampered differentiation. In the presence of G-CSF and GM-CSF, total cells enhanced quickly, and had the most expansion of total cells in comparison with other combinations. However, CFU-GM output peaked at 18 days and subsequently dropped to 0 promptly, suggesting that G-CSF and GM-CSF inspired differentiation.

Cell Culture Techniques↗
PubMed1999

[Effect of tiangui recipe on serum leptin and pituitary gonadotropin in androgen-sterilized rats].

OBJECTIVE: To explore the effect of Tiangui Recipe (TGR) on obesity and reproductive function in androgen-sterilized rats (ASR). METHODS: ASR model was established by subcutaneous injection of testosterone propionate to SD female rats of 9 days age. Change of serum leptin, follicle-stimulating hormone (FSH) and luteinizing hormone (LH) in model rats of 115 days old before and after feeding TGR was measured by radioimmunoassay (RIA). Meanwhile, criteria of energy state, including diurnal food intake, retroperitoneal fat depot weight and body weight, were measured and evaluated. RESULTS: ASR had the characteristics of high metabolic rate, energy imbalance and obesity. Serum level of leptin increased and FSH, LH decreased significantly (P < 0.01) in model rats as compared with the normal rats. Significant positive correlation between leptin level and body weight (r = 0.8977, P < 0.001) was observed, and negative correlation was seen between FSH, LH and leptin (r = -0.7517, P < 0.001; r = -0.8444, P < 0.001, respectively). The endocrinous changes of ASR all returned to normal range after the TGR treatment. CONCLUSION: Obesity and concerned hypogonadotropic hypogonadal anovulation were expressed in ASR. TGR may play an important role in reducing weight and inducing ovulation.

Androgens↗
PubMed1999

[Clinical and experimental study on treatment of retention enema for chronic non-specific ulcerative colitis with quick-acting kuijie powder].

OBJECTIVE: To study the clinical effect and mechanism of retention enema with quick-acting Kuijie powder (QAKJP) in treating chronic non-specific ulcerative colitis (CUC). METHODS: A treatment group of 156 patients treated with QAKJP and a control group of 78 patients treated with sulfasalazine orally were established randomly and their scores of main symptoms and signs were measured and compared before and after treatment. Animal experiments were conducted at the same time. RESULTS: The total effective rate in the treatment and the control group was 98.7% and 70.5% respectively, the clinical cure rate was 78.2% and 6.4% and the recurrence rate was 5.3% and 20.0% respectively. The effect of the treatment group was markedly superior to that of the control group, P < 0.01. Experimental study showed QAKJP could rapidly alleviate the congestion and edema of intestinal mucosa, promote the healing of ulcer, inhibit spasm of colon and had significant antidiarrheal action and antagonist effect against allergic mediator histamine. CONCLUSION: Retention enema with QAKJP has good effect on CUC, low recurrence rate and no toxic and side effect.

Administration, Rectal↗
PubMed1999

[Light puncture combined with longhu xingnao granules in treating acute traumatic intracranial hematoma].

OBJECTIVE: To confirm the clinical therapeutic effectiveness of Longhu Xingnao Granule (LHXNG) medicated after light puncture in treating acute traumatic intracranial hematoma. METHODS: Patients were randomly divided into two groups, 30 patients of the tested group were treated with LHXNG after light puncture and 20 patients of the control group treated with western medicine alone. RESULTS: The effect of the tested group was evidently superior to the control group (P < 0.05) and with a markedly shortened resuscitation time (P < 0.05). CONCLUSION: LHXNG has the function of promoting blood circulation and arresting bleeding, and improving resuscitation. In coordination with light puncture, it could improve the living quality of patients, shorten the resuscitation and treatment time, so as to reduce the maim and death rate.

Adult↗
PubMed1999

[Clinical and experimental study on treatment of chronic pyogenic tympanitis with shenlian ear-drops].

OBJECTIVE: To study the effect and mechanism of Shenlian Ear-Drops (SLED), a composite preparation of Chinese herbal medicine, in treating chronic pyogenic tympanitis (CPT). METHODS: The 201 patients of CPT enrolled were divided randomly into two groups. The treated group were treated with SLED, three times per day, and the control group treated with ofloxacin ear-drop, three times per day. The changes in symptoms, signs and bacterial culture after treatment were observed. Experimental studies on anti-inflammatory, detumescent effect and skin mucosa irritation test, and bacteriostasic activity of SLED were also conducted. RESULTS: The curative effect in the treated group was higher than that in the control group with shorter time of medication. The improvement of symptoms and signs in the former was also better than that in the latter (P < 0.05 or P < 0.01). Experimental study showed SLED had obvious anti-inflammatory and detumescent effect, apparent bacteriostasic activity against often encountered pathogens of CPT, and with no side-effect such as irritation on skin, mucosa of external acoustic meatus or tympanic cavity, and was non-ototoxic. CONCLUSION: SLED has good curative effect in treating CPT.

Administration, Topical↗
PubMed1999

[Effect of TCM on plasma beta-endorphin and placental endocrine in threatened abortion].

OBJECTIVE: To explore the effect of TCM on plasma beta-endorphin (beta-EP) and placental endocrine function in patients of threatened abortions (TA). METHODS: Changes of plasma beta-EP, gonadotrophin releasing hormone (GnRH), human chorionic gonadotrophin (HCG), progesterone (P4) levels were measured with RIA in 40 cases of TA with a history of recurrent spontaneous abortion treated with Chinese herbal medicine for reinforcing Kidney and Qi, hemostasis and antiabortion. And the results were compared with those of normal early pregnant women and patients with incomplete abortion as control. RESULTS: The plasma beta-EP level in TA was significantly higher than that in normal pregnant women, P < 0.01. On the contrary, plasma GnRH, HCG and P4 were obviously lower in TA as compared with those of the normal cases, P < 0.01. After treatment, 36 of the 40 patients succeeded in the continuity of pregnancy, their symptoms of TA disappeared, and the above-mentioned four criteria measured at 10-12th week of gestation were similar to those of normal cases, P > 0.05. CONCLUSION: TCM treatment can regulate plasma beta-EP and placental endocrine function in threatened abortion.

Abortion, Threatened↗
PubMed1999

[Acute rupture of anterior cruciate ligament: diagnosis and treatment by early arthroscopy].

OBJECTIVE: To early diagnose and treat acute rupture of anterior cruciate ligament (ACL). METHODS: 23 patients with acute rupture of ACL were examined and treated by early arthroscopy. RESULTS: The preoperative diagnosis of ACL rupture was similar to that of in 18 patients. Three patients were confirmed by early arthroscopy and 2 patients were found to have ACL rupture, 16 patients were combined with meniscus injuries and 6 patients with cartilaginous injuries. Patholanatomical type of ACL were rupture of parenchymal part (21 patients) and avulsion rupture of attachment point (2 patients). In 6 patients ACL was reconstructed under arthroscope. CONCLUSIONS: Early arthroscopy in the treatment of acute ACL rupture has advantages of minor injury, correct diagnosis, visible location of injury or combined injury and timely treatment. Early arthroscopy for acute ACL rupture is an important measure for diagnosis, treatment, and stabilization of the knee joint.

Acute Disease↗
PubMed1999

[Establishment of a stochastic model for variation in fecal Schistosoma japonicum egg count and estimation of its parameters].

OBJECTIVE: To establish a stochastic model suitable for interpreting the variation in fecal Schistosoma japonicum egg count, and to estimate its parameters and to describe it. METHODS: Total variation in fecal egg count with a stochastic model can be divided into two kinds of sources, (1) inter-individual variation, and (2) intra-individual variation. Parameters in the model were estimated with the data collected in actual fecal egg count. RESULTS: Parameters M and r differed and k kept nearly the same in various age groups. The best cut-off point of r and M for age-splitting was at eight and 12 years, respectively. Parameter k was assumed the same in different age groups in the model E, and r differed in the groups of 2 - 7 years and 8 years of age, and M differed in the groups of 2 - 11 years and 12 years of age, with a minimum value of Akaike information criterion (AIC). CONCLUSION: Age may be an important factor contributing to the estimations of parameters M and r, and the model E was the best one.

Adolescent↗
PubMed1999

[A clinico-pathological study of neuroendocrine tumors in stomach].

OBJECTIVE: To study the pathological classification of gastric neuroendocrine tumors and its clinico-pathological significance. METHODS: Paraffin sections of totally 52 gastric neuroendocrine tumors including 42 carcinoid tumors were studied with immunohistochemical technique, which involved 9 endocrine markers of hormones antibodies and electronic microscopy for investigating the endocrine cells and the contiguous gastric mucosa of the neuroendocrine tumors. RESULTS: The 52 gastric neuroendocrine tumors were divided into three types: Type I, carcinoid, associated with atrophic gastritis, altogether 26 cases. Tumor extension was limited in the mucosa or submucosa, accompanying with hypergastrinemia and G cell hyperplasia. This type is consistently preceded by and associated with generalized proliferation of endocrine cells in the mucosa at fundus. Type II, carcinoid of sporadic type, totally 16 cases, not associating with hypergastrinemia, was more aggressive. Type III, Neuroendocrine carcinomas (10 cases), were highly aggressive tumors. CONCLUSION: A correct identification of different types of gastric endocrine tumors is important and implicit for the treatment and prognosis of neuroendocrine tumors.

Adult↗
PubMed1999

[A clinicopathologic study on eight cases of cystic and solid tumors of pancreas].

OBJECTIVE: To study the clinicopathologic characteristics, differentiation patterns and histogenesis of cystic and solid tumors of the pancreas (CSTP). METHODS: 8 cases of CSTP were studied using histologic (HE and PAS), immunohistochemical (S-P method) and electron microscopic techniques. RESULTS: All the patients were adolescent and young adult females, 14-33 years in age (mean 25.3 years) without recurrence after tumor resection. The mean diameter of tumors was 9.6 cm, all encapsulated. Histological examination showed presence of solid sheets, pseudopapillary, in all of the cases. Hemorrhage, foam cells, and cholesterol crystals were often found. Immunohistochemically, 8 cases were positive for alpha(1)-AT and lysozyme; 6 cases expressed vimentin, 2 cases expressed actin, and CgA-positive cells found in the tumor cell nests in one case. All of the cases showed PR, and 4 cases showed ER positive immunoreactivity in the majority of tumor cells, but negative for CK AE1, CK AE3, EMA, Synaptophysin, ACTH, gastrin, somatostatin, insulin, and glucogan in all the cases. Electron microscopy of 3 cases showed evidences of polymorphism in differentiation of the tumor cells, including the transitional appearance into ducts, acinus, and endocrine cells. Weibel-Palade body found in tumor cells in one out of 8 cases. CONCLUSIONS: (1) CSTP is a distinct clinicopathologic entity in young female patients with a benign clinical course. (2) CSTP develops from primitive pancreatic cells, with the potentiality of developing into ducts, acinus, and endocrine cells.

Actins↗
PubMed1999

[Effect of human inhibin alpha-fragment 1-32-Tyr(P33) on apoptosis of cultured rat corpus luteal cells].

Recently, increasing evidence suggests that alpha inhibin or related proteins may be a functional regulator in the ovary, which is independent of hetero-dimer inhibin. In our previous study, it was demonstrated that human inhibin alpha-N-terminal fragment Tyr-1-32 (P(33)) significantly inhibited progesterone production by rat corpus luteal cells in vitro, and stimulated luteal functional regression and apoptosis in vivo. In the present work, the action of P(33) on apoptosis was further studied in vitro in cultured rat CL cells. Gel electrophoretic analysis for detection of oligonucleosomal DNA fragmentation, AO-EB or PI assays and flow cytometry were used to observe the action of P(33) on the occurrence of spontaneous apoptosis by collagenase-DNase dispersed CL cells, obtained from PMSG-hCG induced pseudopregnant rats. The results showed that P(33) (1 microg/ml) stimulated spontaneous apoptosis of CL cells. The inhibitor of tyrosine protein kinase, genistein (50 microg/ml),inhibited P(33) enhanced spontaneous apoptosis. RNA and protein synthesis inhibitors cycloheximide (Cyx,50 microg/ml) and actinomycin D(Act D,50 microg/ml) did not protect the cells from apoptosis stimulated by P(33). The results suggest that P(33) stimulates spontaneous apoptosis in cultured rat CL cells with the involvement of tyrosine specific protein kinase system. This work provides further evidence for the hypothesis that alpha inhibin or related protein might be a functional regulator in the ovary.

Animals↗