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Biomedical subjects

S Song

Publications and source records attributed to S Song.

At least 91 records · Page 5Linked to original sources
PubMed2000

Porcine von Willebrand factor and thrombin induce the activation of c-Jun amino-terminal kinase (JNK/SAPK) whereas only thrombin induces activation of extracellular signal-related kinase 2 (ERK2) in human platelets.

The interaction of platelets with subendothelial von Willebrand factor (VWF), especially under high shear stress, is considered to be the first activation step which primes platelets for subsequent haemostatic events. The signalling cascade which results from the interaction of VWF and its receptor GPIbIX has only been partially defined. Mitogen-activated protein kinases (MAPKs) are a family of downstream transmembrane signalling serine-threonine kinases and have been demonstrated to be present and functional in platelets; these include the extracellular signal-related kinases (ERKs), c-Jun amino-terminal kinases (JNKs) and p38 MAPK. Previously, we showed that p38 MAPK was not required in VWF-induced human platelet activation. It is not known whether VWF-dependent platelet activation involves the activation of the JNK and ERK family of signalling molecules. This report demonstrates that porcine von Willebrand factor (pVWF) induced a sustained and stable JNK activation measurable by 1 min after activation. Thrombin also induced JNK activation assessed at 1 min after activation. In contrast to thrombin, pVWF did not induce ERK2 activation at any time point tested. To ensure that ERK activation was unnecessary for pVWF-dependent platelet activation, we functionally inhibited ERK-dependent signalling with PD98059, a potent and selective inhibitor of the MAP kinase kinase (MEK-1), which is the upstream kinase of ERK1 and ERK2. Although PD98059 inhibited ERK2 activation in platelets, it had no effect on pVWF- or thrombin-induced platelet alpha or lysozomal granule release, modulation of membrane glycoprotein CD41, microparticle formation, platelet shape change or platelet agglutination. It is concluded that pVWF and thrombin induced JNK activation, but whereas thrombin induced ERK2 activation VWF did not; functional ERK2 activity was also not required for pVWF- or thrombin-dependent platelet activation.

Animals↗
PubMed2000

Magnetic resonance imaging features of subacute idiopathic brachial neuritis.

A 60-year-old man presented with sudden onset of left shoulder pain followed 2 weeks later by the development of left shoulder girdle weakness. A clinical and electrophysiological diagnosis of subacute idiopathic brachial neuritis was made. The MRI features of subacute muscular denervation in this patient are discussed and the relevant literature reviewed.

Brachial Plexus Neuritis↗
PubMed2000

Analysis of intracranial mass lesions using proton magnetic resonance spectroscopy at 1.0 T: pictorial essay.

Proton MR spectroscopy has been used to characterize the spectroscopic profiles of a wide variety of neurological disease processes. In particular, the spectroscopic characteristics of a range of focal intracranial mass lesions have been described. The use of proton MR spectroscopy has until recently been restricted to major research centres with high-field MR scanners. The spectroscopic findings in a number of illustrative cases imaged at Royal Perth Hospital using a 1-T scanner are described here. The cases illustrated in the present paper confirm the clinical utility of proton MR spectroscopy as a supplement to conventional MR in routine radiological practice.

Adult↗
PubMed2000

Influence of age and gender on thoracic vertebral body shape and disc degeneration: an MR investigation of 169 cases.

There are limited data detailing the pattern of age and gender-related changes to the thoracic vertebral bodies and intervertebral discs. A retrospective MR investigation, involving T1-weighted midsagittal images from 169 cases, was undertaken to examine age influences on the anterior wedge (anteroposterior height ratio or Ha/Hp), biconcavity (midposterior height ratio or Hm/Hp), and compression indices (posterior height/anteroposterior diameter or Hp/D) of the thoracic vertebral bodies. Disc degenerative changes in the annulus, nucleus, end-plate and disc margin were noted on T2-weighted sagittal images for the 169 cases, based on a 3-level grading system. A linear age-related decline in the Ha/Hp and Hm/Hp indices was noted. The Hp/D index increased during the first few decades of life, then decreased gradually thereafter. The prevalence of abnormal findings in the annuli, nuclei and disc margins increased with increasing age, particularly in the mid and lower thoracic discs. Greater disc degenerative changes were observed in males. These findings provide further insight into the nature of thoracic vertebral shape changes across the lifespan, and the typical patterns of degeneration of the thoracic intervertebral discs.

Adolescent↗
PubMed2000

MRI evaluation of lumbar spine flexion and extension in asymptomatic individuals.

Flexion and extension movements or positions have been advocated in the treatment of various forms of low back dysfunction due to the potential pain relieving effects attributed to displacements of the intervertebral disc (IVD). Objective in vivo determination of the segmental behaviour of the disc to contrasting positions has until recently been difficult. Magnetic resonance imaging (MRI) was used in this study to evaluate the influence of sagittal plane positions on lumbar IVD height and nucleus displacement in a small asymptomatic population.T2-weighted sagittal plane images from L1 to S1 were obtained from 10 subjects (mean age: 30+/-5 years) positioned supine in lumbar flexion, followed by extension. Changes in disc height and localization of nucleus position (determined by peak MRI signal intensity) between the two positions were calculated. Discs were classified for degenerative changes using a semi-quantitative grading scale. The mean range of lumbar sagittal movement achieved in the MRI was 44 degrees (range: 22-77 degrees ). Between flexion and extension, a significant increase in measured anterior disc height of 1.1 mm (P<0.0001) and anterior displacement of the nucleus of 6.7% (P<0.0001) was observed. Despite the anterior displacement of the nucleus in extension observed in the pooled analysis, 30% of discs did not follow this trend. Nucleus degeneration was observed in at least one disc in nine subjects and in 26% of all discs examined. Lumbar spine position was found to be associated with small measured changes in anterior disc height and nucleus position, however, this response was variable within and between individuals. The theoretical concept of a stereotypical effect of spinal position on the lumbar IVD is challenged by these initial data. Since the health of the disc is often unknown in clinical practice, manual therapy treatment for lumbar spine pain should be based on the symptomatic response to movement and position rather than biomechanical theory.

Adult↗
PubMed2000

Can the glyoxylate pathway contribute to fat-induced hepatic insulin resistance?

Recent studies have shown that increased hepatic gluconeogenesis is the predominant contributor to fasting hyperglycemia - the hallmark of type 2 diabetes. Although it has been known for a long time that over-supply of fat is able to stimulate gluconeogenesis both in-vitro and in-vivo, neither the leading substrate nor the mechanism responsible for this phenomenon have been fully identified. Recent observations that the glyoxylate pathway may exist in animals has shed light on this question. The glyoxylate pathway is able to convert fatty acid into glucose but has been thought to be absent in animals. Although further evidence is needed, current available data does suggest a possible mechanism which, by integrating both glucose and lipid metabolism together rather than interpreting them separately, may explain the role of fatty acids in hepatic insulin resistance. This hypothesis is based on current understanding of insulin resistance and supported by many laboratory observations.

Animals↗
PubMed2000

Chronic fatigue syndrome: occupation, medical utilization, and subtypes in a community-based sample.

Most studies of chronic fatigue syndrome (CFS) have been based on patients recruited from primary or tertiary care settings. Patients from such settings might not be typical of patients in the general population. The present investigation involved examining individuals with CFS from a community-based study. A random sample of 18,675 respondents in Chicago was first interviewed by telephone. A group of individuals with chronic fatigue accompanied by at least four minor symptoms associated with CFS were given medical and psychiatric examinations. From this sample, a physician review group diagnosed individuals with CFS. Those diagnosed with CFS were subclassified based on a variety of categories, including duration of illness, mode of illness onset, and presence or absence of a stressful life event directly preceding onset. In addition, we examined medical utilization among those diagnosed with CFS, as well as whether individuals with CFS were disproportionately represented in health care professions. Important differences emerged on measures of sociodemographics, symptoms, and functional disability. The implications of these findings and others are discussed.

Adult↗
PubMed2000

Detection and identification of mycobacteria by amplification of the internal transcribed spacer regions with genus- and species-specific PCR primers.

We evaluated the usefulness of PCR assays that target the internal transcribed spacer (ITS) region for identifying mycobacteria at the species level. The conservative and species-specific ITS sequences of 33 species of mycobacteria were analyzed in a multialignment analysis. One pair of panmycobacterial primers and seven pairs of mycobacterial species-specific primers were designed. All PCRs were performed under the same conditions. The specificities of the primers were tested with type strains of 20 mycobacterial species from the American Type Culture Collection; 205 clinical isolates of mycobacteria, including 118 Mycobacterium tuberculosis isolates and 87 isolates of nontuberculous mycobacteria from 10 species; and 76 clinical isolates of 28 nonmycobacterial pathogenic bacterial species. PCR with the panmycobacterial primers amplified fragments of approximately 270 to 400 bp in all mycobacteria. PCR with the M. tuberculosis complex-specific primers amplified an approximately 120-bp fragment only for the M. tuberculosis complex. Multiplex PCR with the panmycobacterial primers and the M. tuberculosis complex-specific primers amplified two fragments that were specific for all mycobacteria and the M. tuberculosis complex, respectively. PCR with M. avium complex-, M. fortuitum-, M. chelonae-, M. gordonae-, M. scrofulaceum-, and M. szulgai-specific primers amplified specific fragments only for the respective target organisms. These novel primers can be used to detect and identify mycobacteria simultaneously under the same PCR conditions. Furthermore, this protocol facilitates early and accurate diagnosis of mycobacteriosis.

Base Sequence↗
PubMed2000

Essential function of the polo box of Cdc5 in subcellular localization and induction of cytokinetic structures.

Members of the polo subfamily of protein kinases play pivotal roles in cell proliferation. In addition to the kinase domain, polo kinases have a strikingly conserved sequence in the noncatalytic C-terminal domain, termed the polo box. Here we show that the budding-yeast polo kinase Cdc5, when fused to green fluorescent protein and expressed under its endogenous promoter, localizes at spindle poles and the mother bud neck. Overexpression of Cdc5 can induce a class of cells with abnormally elongated buds in a polo box- and kinase activity-dependent manner. In addition to localizing at the spindle poles and cytokinetic neck filaments, Cdc5 induces and localizes to additional septin ring structures within the elongated buds. Without impairing kinase activity, conservative mutations in the polo box abolish the ability of Cdc5 to functionally complement the defect associated with a cdc5-1 temperature-sensitive mutation, to localize to the spindle poles and cytokinetic neck filaments, and to induce elongated cells with ectopic septin ring structures. Consistent with the polo box-dependent subcellular localization, the C-terminal domain of Cdc5, but not its polo box mutant, is sufficient for subcellular localization, and its overexpression appears to inhibit cytokinesis. These data provide evidence that the polo box is required to direct Cdc5 to specific subcellular locations and induce or organize cytokinetic structures.

Amino Acid Sequence↗
PubMed2000

Chronic fatigue syndrome: sociodemographic subtypes in a community-based sample.

Most chronic fatigue syndrome (CFS) studies are based on information about patients from primary or tertiary care settings. These patients might not be typical of patients in the general population. This investigation involved examinations of individuals with CFS from a community-based study. A random sample of 18,675 in Chicago was interviewed by telephone. Individuals with chronic fatigue and at least four minor symptoms associated with CFS were given medical and psychiatric examinations. A group of physicians then diagnosed individuals with CFS, who were then subclassified based on three sociodemographic categories--gender, ethnicity, and work status. Sociodemographic subgroups were analyzed in terms of symptom severity, functional disability, coping, optimism, perceived stress, and psychiatric comorbidity. Women, minorities, and nonworking individuals with CFS reported greater levels of functional disability, symptom severity, and poorer psychosocial functioning than men, Caucasians, and working individuals, suggesting sociodemographic characteristics may be associated with poorer outcomes in urban, community-based samples of CFS individuals.

Adolescent↗
PubMed2000

[Comparison on effects between concentrated-dose and non-concentrated-dose pralidoxime chloride on respiratory muscle paralysis in acute organophosphorus pesticide poisoning].

OBJECTIVE: To compare the effects between concentrated-dose and non-concentrated-dose pralidoxime chloride on respiratory muscle paralysis(RMP) in acute organophosphorus pesticide poisoning(AOPP). METHODS: 76 cases of RMP due to AOPP were involved in a retrospective study. All the patients were poisoned through ingestion. According to the administered dose of pralidoxime chloride within the first three days after the onset, the patients were divided into two groups: Group A consisted 30 patients; they were given pralidoxime chloride 10.0-25.8 grams (with an average of 11.4 grams) everyday in the first three days after the onset. Group B included 46 patients; the dose of pralidoxime chloride used daily in the first three days ranged from 3.3 to 8.6 grams (average 6.3). RESULTS: The curative rate and the death rate in group A were 73.3% and 26.7% respectively, while those in group B were 21.7% and 78.3% respectively. The curative rate in group A was significantly higher than that in group B (chi 2 = 19.83, P < 0.005). CONCLUSION: Concentrated-dose pralidoxime chloride was more effective than non-concentrated-dose for patients with RMP due to AOPP and this kind of administration could remarkably improve the prognosis in such patients.

Adolescent↗
PubMed2000

[Numerical simulation on maize growth in a regular windbreak system in Huanghuaihai Plain].

The modified production ecological model SUCROS was used to simulate the growth process of summer corn with the protection of windbreaks in Huanghuaihai Plain, and the simulated result was compared with the field monitoring data. The effects of various physiological and ecological factors that affect the growth of the summer corn were analyzed. The modified SUCROS could simulate the growth process successfully. The leaf area index and organ biomass simulated by the model could be fairly consistent with the monitoring data when the effects of insect and disease pests and weeds were considered simultaneously. As compared with the simulated data in the monoculture field, the corn yield in the windbreak system was about 6.8% higher due to the improved microclimate. Based on the simulation of the relationships between sowing density, sowing date and seed production, the density standard for high yield in the region was 6.75-7.50 plants.m-2, even high as 9.00 plants.m-2 in the fields with sufficient soil nutrients and water supply. It is suggested that the optimal sowing period is from May 21 to June 5. Through simulating the influence of "cool summer" on the growth of summer corn in southern Huanghuaihai Plain, it was found that the growth period of corn would extend 3 to 4 days if the average air temperature during the growing period lowered by one degree. The "less radiation" and correspondent "lower temperature" were the direct reasons of yield reduction in "cool summer".

Biomass↗
PubMed2000

[Diagnosis and treatment of primary retroperitoneal teratoma].

OBJECTIVE: To study the diagnosis and treatment of primary retroperitoneal teratoma in adults. METHODS: The clinical data of 36 adult patients with primary retroperitoneal teratoma were reviewed. RESULTS: Nine patients were male and 27 female. Twenty-four patients (66.7%) aged (30.4 +/- 8.0) years were benign, and 12 patients (36.3%) aged (39.6 +/- 10.5) years were malignant. Four (21.1%) cases of presacral tumors and 8 (47.1%) of 17 cases of epigastric tumors were malignant. Clinical features included abdominal or presacral masses and compression symptoms with or without tumor markers. All patients, except one with liver metastasis, underwent radical resection. Patients without malignant metastasis survived, but 5 patients with malignant metastasis survived more than 2 years after operation. CONCLUSIONS: Malignant metastasis of retroperitoneal teratoma is closely related to the age of adults. Early radical resection is the optimal treatment. Adjuvant chemotherapy can induce a short-time remission in those with germ cell elements.

Adolescent↗
PubMed1999

The polo-box-dependent induction of ectopic septal structures by a mammalian polo kinase, plk, in Saccharomyces cerevisiae.

Members of the polo subfamily of protein kinases play pivotal roles in cell-cycle control and proliferation. In addition to a high degree of sequence similarity in the kinase domain, polo kinases contain a strikingly conserved motif termed "polo-box" in the noncatalytic C-terminal domain. We have previously shown that the mammalian polo-like kinase Plk is a functional homolog of Saccharomyces cerevisiae Cdc5. Here, we show that, in a polo-box- and kinase activity-dependent manner, ectopic expression of Plk in budding yeast can induce a class of cells with abnormally elongated buds. In addition to localization at spindle poles and cytokinetic neck filaments, Plk induces and localizes to ectopic septin ring structures within the elongated buds. In contrast, mutations in the polo-box abolish both localization to, and induction of, septal structures. Consistent with the polo-box-dependent subcellular localization, the C-terminal domain of Plk, but not its polo-box mutant, is sufficient for subcellular localization. Our data suggest that Plk may contribute a signal to initiate or promote cytokinetic event(s) and that an intact polo-box is required for regulation of these cellular processes.

Actins↗
PubMed1999

Comparative gene expression profiling in response to p53 in a human lung cancer cell line.

The p53 tumor suppressor gene functions through the p53-mediated transcriptional activation and regulation of critical downstream target genes. The mechanism behind such regulation, however, remains unclear. In this study, we compared the expression of 30 genes that are involved in cell cycle checkpoint control and/or apoptosis in a human lung cancer cell line, which contains endogenous wild-type p53, in response to ectopic p53 expression. Of the 30 genes studied, 22 genes have shown an increase in expression. The increase in gene expression of 2 genes-Gadd45 and PIG2-was more than 10-fold. These results suggest that the genes with the highest expression level in a p53-dependent pathway may play a dominant role in determining the pathway that the cell follows: cell cycle arrest or apoptosis. Our screen illustrates the development of a simple and inexpensive p53-specific cDNA array to begin to analyze downstream events in the p53 pathway under physiological, pathological, and stress-induced states.

Apoptosis↗
PubMed1999

Induction of CD40 on human endothelial cells by Alzheimer's beta-amyloid peptides.

Growing evidence suggests that beta-amyloid (Abeta) peptides play a central role in mediating vascular endothelium dysfunction, but the extent to which immune mechanisms are involved in this process remains unclear. To explore such mechanisms, we incubated cultured human aortic endothelial cells (HAEC) with freshly solublized Abeta and examined expression of a central immunoregulatory molecule, CD40, in these cells using reverse transcriptase-polymerase chain reaction, Western immunoblotting, and Flow cytometry. Our results show that treatment of endothelial cells with Abeta1-40, Abeta1-42 or gamma interferon (IFN-gamma) results in a dose-dependent induction of endothelial CD40 expression. Furthermore, ligation of endothelial CD40 and simultaneous treatment of human endothelial cells with IFN-gamma or Abeta peptides leads to a significant release of interleukin-1beta (IL-1beta), a marker for endothelial cell activation. Since IL-1beta is an important inflammatory response mediator, these findings suggest that the functional role of Abeta-induced endothelial CD40 may be promotion of the inflammatory cascade in vascular endothelial cells.

Alzheimer Disease↗
PubMed1999

[Observation on effect of chongcao shenkang capsules in preventing and treating acute renal failure in cases of hemorrhagic fever with renal syndrome].

OBJECTIVE: To observe the effect of Chongcao shenkang capsules in preventing and treating acute renal failure in cases of hemorrhagic fever with renal syndrome (HFRS). METHODS: 150 cases of HFRS were randomly divided into two groups: the treatment group and the control group. The former contained 76 cases and the latter the 74 cases. All cases in both groups were given a combined therapy mainly composed of balanced salt solution and ribavirin, cases in treatment group additionally accepted Chongcao shenkang capsules 2.7 grams tid, till the end of polyuric phase. RESULTS: The results showed that in the treatment group the occurrence rate of cases with oliguric phase was 13.0% (4/46) and the oliguric and polyuric periods were 2.7 +/- 1.6 days and 6.8 +/- 2.9 days respectively while those in the control group were 31.1% (4/45), 4.3 +/- 2.1 dnys and 8.2 +/- 3.4 days respectively (P < 0.01 or P < 0.05). The urinary protein of the treatment group disappeared within 5.1 +/- 2.3 days and their serum creatinine restored within 10.9 +/- 6.2 days, but the urinary protein disappearing and the serum creatinine restoring periods of the control group were 6.8 +/- 2.7 days and 13.7 +/- 7.4 days respectively (P < 0.01 or P < 0.05). The serum and urine beta 2-microglobulin levels of the treatment group were remarkably lower than those of the control group on the fifth and tenth days after treatment (P < 0.01 or P < 0.05). Compared with those of the control group of 33.8% (25/74) and 87.8% (65/74), the occurrence rate of severe complications and curative rate of the treatment group were 18.4% (14/76) and 94.7% (72/76) respectively (the former P < 0.05, but the latter P > 0.05). CONCLUSION: It was concluded that Chongcao shenkang capsules is capable of reducing the occurrence rate of acute renal failure in HFRS patients, shortening the duration of acute renal failure, decreasing their needs for dialysis, lessening their complications and increasing their curative rate. Its administration is safe and convenient and therefore it is worthy to be popularized.

Acute Kidney Injury↗