Biomedical subjects
S Sun
Publications and source records attributed to S Sun.
Decreases in mesenteric blood flow associated with increases in sublingual PCO2 during hemorrhagic shock.
We investigated relationships between visceral blood flow, intestinal wall carbon dioxide tension (PCO2), and sublingual PCO2 during hemorrhagic shock. In five pigs, cardiac output declined 81% and superior mesenteric blood flow 77% during hemorrhage. Duodenal PCO2 increased from an average of 50 to 121 mmHg and sublingual PCO2 concurrently increased from an average of 46 to 101 mmHg. Within 60 min after reinfusion of shed blood, duodenal and sublingual PCO2 returned to baseline values. Decreases in mesenteric blood flow were correlated with increases in sublingual (r = 0.91; P < 0.001) and duodenal (r = 0.89; P < 0.001) tissue PCO2. In five randomized "sham hemorrhage" control animals, neither decreases in cardiac output or mesenteric blood flow nor increases in duodenal or sublingual PCO2 were observed. Decreases in mesenteric blood flow during hemorrhage were therefore associated with early and comparable increases in tissue PCO2 in both visceral and sublingual sites.
Airway epithelial cell wound repair mediated by alpha-dystroglycan.
Dystroglycans (DGs) bind laminin matrix proteins in skeletal and cardiac muscle and are expressed in other nonmuscle tissues. However, their expression in airway epithelial cells has not been demonstrated. We examined expression of DGs in the human airway epithelial cell line 1HAEo(-), and in human primary airway epithelial cells. Expression of the common gene for alpha- and beta-DG was demonstrated by reverse transcriptase/ polymerase chain reaction in 1HAEo(-) cells. Protein expression of beta-DG was demonstrated by both Western blot and flow cytometry in cultured cells. Localization of alpha-DG, using both a monoclonal antibody and the alpha-DG binding lectin wheat-germ agglutinin (WGA), was to the cell membrane and nucleus. We then examined the function of DGs in modulating wound repair over laminin matrix. Blocking alpha-DG binding to laminin in 1HAEo(-) monolayers using either glycosyaminoglycans or WGA attenuated cell migration and spreading after mechanical injury. alpha-DG was not expressed in epithelial cells at the wound edge immediately after wound creation, but localized to the cell membrane in these cells within 12 h of injury. These data demonstrate the presence of DGs in airway epithelium. alpha-DG is dynamically expressed and serves as a lectin to bind laminin during airway epithelial cell repair.
Initiation of apoptosis by actin cytoskeletal derangement in human airway epithelial cells.
Changes in epithelial cell shape can lead to cell death and detachment. Actin filaments are cleaved during apoptosis, but whether disruption in the actin cytoskeletal network, as one manifestation of cell shape change, can itself induce apoptosis is not known. We tested this hypothesis in the airway epithelial cell line 1HAEo(-) and in primary airway epithelial cells by preventing actin filament elongation with cytochalasin D or by aggregating actin filaments with jasplakinolide. Disruption of actin filament integrity promptly induced apoptosis in adherent epithelial cells within 5 h. Jasplakinolide-induced apoptosis did not disrupt focal adhesions, whereas cytochalasin D-induced apoptosis decreased focal adhesion protein expression and occurred despite ligation of the fibronectin receptor. Death induction was abrogated by the caspase inhibitors z-VAD-fmk and Ac-DEVD-cho but not by blocking the Fas (CD95) receptor. Whereas cytochalasin D--induced apoptosis was associated with cleavage of pro-caspase-8, jasplakinolide-induced apoptosis was not. Both agents induced formation of a death-inducing signaling complex. These data demonstrate that disruption of actin filament integrity with either cytochalasin D or jasplakinolide induces apoptosis in airway epithelial cells but by different mechanisms, and suggest that actin may be an early modulator of apoptotic commitment.
Polycyclic aromatic hydrocarbon diol epoxides increase cytosolic Ca(2+) of airway epithelial cells.
Polycyclic aromatic hydrocarbons (PAHs) increase cytosolic Ca(2+) concentration ([Ca(2+)](i)) in lymphocytes and mammary epithelial cells, but little is known regarding their effects on [Ca(2+)](i) in airway epithelium. We hypothesized that benzo[a]pyrene (BP) and/or anti-7,8-dihydroxy-9,10-epoxy-7,8,9,10-tetrahydrobenzo[a]pyrene (BPDE), a carcinogenic BP metabolite, increases [Ca(2+)](i) in untransformed human small airway epithelial (SAE) cells and that their effects on [Ca(2+)](i) are directly proportional to carcinogenicity. SAE [Ca(2+)](i) was determined by a ratiometric digital Ca(2+) imaging system. BPDE increased SAE [Ca(2+)](i) within 20 s in media with high (1 mM) and low (10 nM) Ca(2+) at a threshold concentration of 0.2 nM. Elevation of [Ca(2+)](i) persisted longer with high Ca(2+). Neither BP nor solvent altered [Ca(2+)](i). Thapsigargin and inositol 1,4,5- phosphate receptor (InsP(3)R) antagonists inhibited this BPDE action with low Ca(2+). We conclude that BPDE but not BP increases [Ca(2+)](i) partly by mobilizing Ca(2+) from cytosolic stores through an InsP(3)R. The most potent carcinogenic PAH diol epoxide increased in SAE [Ca(2+)](i) at the lowest threshold concentration, suggesting that carcinogenicity is directly proportional to the action of PAHs on SAE [Ca(2+)](i). Short-term exposure to BPDE 36 to 48 h before the study rendered SAE cells less sensitive to BPDE, suggesting that BPDE may also induce persistent changes in Ca(2+) signaling pathways.
Electronic and resonance effects on the ionization of structural analogues of efavirenz.
The solubility of 4 analogues of efavirenz was studied as a function of pH. The study evaluated the ionization behavior and determined the relative contribution of electronegative substituents versus resonance effects on the pK(a) value of the cyclic carbamate. The most profound lowering effect on the pK(a) was due to the presence of multiple electronegative substituents and in particular the trifluoromethyl and acetylene groups. The presence of chlorine on the benzoxazinone ring was found to have a slight impact on the pK(a), although to a lesser extent. In the absence of any functional groups on the benzoxazinone ring system, the pKa shifted to a value of 13.2, which is 3 pH units above that of efavirenz and more closely correlates with typical literature values for cyclic carbamates.
Ethnic and environmental differences in various markers of dietary intake and blood pressure among Chinese Han and three other minority peoples of China: results from the WHO Cardiovascular Diseases and Alimentary Comparison (CARDIAC) Study.
Our aim was to examine differences in dietary intake and blood pressure (BP) and their associations in four different ethnic Chinese populations, the Han, the Uygur, the Kazak and Tibetan subjects. This study used a sub-database of the Chinese sample of the WHO-Cardiovascular Diseases and Alimentary Comparison (CARDIAC) Study. The WHO-CARDIAC Study was a multicenter cross-sectional study. In each center, 100 men and 100 women aged 48-56 years were selected at random from the local population. Various markers of dietary intake and their relation with BP were studied. The results of the present study indicated the following. 1) There were significant differences in mean BP and prevalence rates of hypertension, with both being higher in the Kazak and Tibetan subjects than in Han and Uygur subjects. 2) The highest mean body mass index (BMI) was observed in the Kazak subjects, while the highest 24-h urinary sodium (Na) and sodium to potassium (Na/K) ratio excretion were observed in the Tibetan subjects. There were also significant differences in other factors, such as magnesium, 3-methylhistidine (3MH) (a biological marker of animal protein intake) and taurine (a biological marker of seafood intake) excretion levels among the four ethnic peoples. 3) In general, BMI, Na and/or Na/K ratios were positively, and 3MH/creatinine and taurine/creatinine ratios were negatively associated with BP. 4) After adjustment for age, sex and potassium, subjects with obesity (BMI > or =26 kg/m2) had significantly higher relative risk of being hypertensive (HT) than those with BMI<26 kg/m2 in the Han, Uygur and Kazak populations; and subjects with elevated sodium excretion (Na > or =244 mmol/day) had significantly higher relative risk of being HT than those with Na<244 mmol/day in the Han, Uygur and Tibetan populations. In conclusion, mean BP and prevalence rates of hypertension were significantly different among the four ethnic groups. These differences are likely to be due, at least in part, to the differences in several diet-related factors, which in turn are associated with culture and environmental differences. Different health promotion strategies might thus be emphasized in different populations.
Effect of long-term exposure to fluoride in drinking water on risks of bone fractures.
Findings on the risk of bone fractures associated with long-term fluoride exposure from drinking water have been contradictory. The purpose of this study was to determine the prevalence of bone fracture, including hip fracture, in six Chinese populations with water fluoride concentrations ranging from 0.25 to 7.97 parts per million (ppm). A total of 8266 male and female subjects > or =50 years of age were enrolled. Parameters evaluated included fluoride exposure, prevalence of bone fractures, demographics, medical history, physical activity, cigarette smoking, and alcohol consumption. The results confirmed that drinking water was the only major source of fluoride exposure in the study populations. A U-shaped pattern was detected for the relationship between the prevalence of bone fracture and water fluoride level. The prevalence of overall bone fracture was lowest in the population of 1.00-1.06 ppm fluoride in drinking water, which was significantly lower (p < 0.05) than that of the groups exposed to water fluoride levels > or =4.32 and < or =0.34 ppm. The prevalence of hip fractures was highest in the group with the highest water fluoride (4.32-7.97 ppm). The value is significantly higher than the population with 1.00-1.06 ppm water fluoride, which had the lowest prevalence rate. It is concluded that long-term fluoride exposure from drinking water containing > or =4.32 ppm increases the risk of overall fractures as well as hip fractures. Water fluoride levels at 1.00-1.06 ppm decrease the risk of overall fractures relative to negligible fluoride in water; however, there does not appear to be similar protective benefits for the risk of hip fractures.
A comparison of biphasic and monophasic waveform defibrillation after prolonged ventricular fibrillation.
STUDY OBJECTIVE: To compare the effects of biphasic defibrillation waveforms and conventional monophasic defibrillation waveforms on the success of initial defibrillation, postresuscitation myocardial function, and duration of survival after prolonged duration of untreated ventricular fibrillation (VF), including the effects of epinephrine. DESIGN: Prospective, randomized, animal study. SETTING: Animal laboratory and university-affiliated research and educational institute. PARTICIPANTS: Domestic pigs. INTERVENTIONS: VF was induced in 20 anesthetized domestic pigs receiving mechanical ventilation. After 10 min of untreated VF, the animals were randomized. Defibrillation was attempted with up to three 150-J biphasic waveform shocks or a conventional sequence of 200-J, 300-J, and 360-J monophasic waveform shocks. When reversal of VF was unsuccessful, precordial compression was performed for 1 min, with or without administration of epinephrine. The protocol was repeated until spontaneous circulation was restored or for a maximum of 15 min. MEASUREMENTS AND RESULTS: No significant differences in the success of initial resuscitation or in the duration of survival were observed. However, significantly less impairment of myocardial function followed biphasic shocks. Administration of epinephrine reduced the total electrical energy required for successful resuscitation with both biphasic and monophasic waveform shocks. CONCLUSIONS: Lower-energy biphasic waveform shocks were as effective as conventional higher-energy monophasic waveform shocks for restoration of spontaneous circulation after 10 min of untreated VF. Significantly better postresuscitation myocardial function was observed after biphasic waveform defibrillation. Administration of epinephrine after prolonged cardiac arrest decreased the total energy required for successful resuscitation.
Overexpression of cyclin D1 moderately increases ploidy in megakaryocytes.
BACKGROUND AND OBJECTIVES: Megakaryocytes undergo a unique cell cycle by which they replicate their complete genome many times in the absence of cytokinesis. In the search for regulators of the endomitotic cell cycle, we previously produced mice transgenic for cyclin D3 to identify this cyclin as able to enhance ploidy and to increase the number of differentiated cells in the megakaryocytic lineage. Of the D-type cyclins, cyclin D3 and to a much lesser extent cyclin D1, are present in megakaryocytes undergoing endomitosis and these cyclins are, respectively, markedly and moderately upregulated following exposure to the ploidy-promoting factor, Mpl-ligand. Our objective was to explore whether cyclin D1 can mimic the effect of cyclin D3 on ploidy in megakaryocytes. DESIGN AND METHODS: We generated transgenic mice overexpressing cyclin D1 in megakaryocytes and analyzed megakaryocyte ploidy, number and platelet levels in these mice and control mice. RESULTS: We show that transgenic mice in which cyclin D1 is overexpressed in megakaryocytes display higher ploidy level than the control mice, with no change in the number of differentiated cells of the megakaryocytic series, or in platelet level. INTERPRETATION AND CONCLUSIONS: Our models support a key role for D-type cyclins in the endomitotic cell cycle, and also indicate that although cyclin D3, from among the D cyclins, is unique in its high levels of expression in megakaryocytes, it is not unique in its ability to promote polyploidization.
Clinical study on treatment of chronic renal failure with shenshuailing.
The therapeutic effects of Shenshuailing Kou Fu Ye (SKFY [symbol: see text], the Oral Liquid for Renal Failure) and Shenshuailing Guan Chang Ye (SGCY [symbol: see text], the Enema for Renal Failure) were evaluated in treatment of chronic renal failure, with coateg aldehyde oxystarch as the controls. The changes in the clinical symptoms, serum creatinine, blood urea nitrogen and creatinine clearance rate were observed. The total effective rate in the former was 90.46%, and the latter 60.43%.
Systematic analysis of bulk blue ballpoint pen ink by FTIR spectrometry.
A classifying method on bulk blue ballpoint pen ink has been studied by Fourier transform infrared (FTIR) spectroscopy. By using this method, a total of 108 blue ink samples have been divided into two groups depending on their main component. Spectral characteristics of these inks such as frequency and absorbance are described by way of artificial intelligence of pattern recognition, and 35 subgroups from the 108 inks are distinguished by their correlation coefficient (lambda). Under heat or exposure to ultraviolet light a mode of change in the age of the inks has been obtained. This approach has provided a reliable and nondestructive method for the characterization of bulk ballpoint writing ink, and more importantly, it might be a basis for dating of the blue ballpoint pen ink.
Pseudo-cerebrospinal fluid rhinorrhea following traumatic cerebrospinal fluid rhinorrhea surgery: a case report.
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Epidemiological investigation of Histoplasma capsulatum infection in China.
OBJECTIVE: To provide reliable information concerning the presence or the absence of Histoplasma capsulatum (H. capsulatum) infection in China, and data concerning this respect. METHODS: Three hundred normal people and 435 hospitalized patients, who lived in Hunan and Jiangsu provinces, and the Xinjiang Autonomous Region, were tested with yeast-phase histoplasmin (ALK/Berkerley Biologicals Laboratories, USA) and human pure protein derivative of tuberculin (PPD) on the volar surface of the forearm. Any reaction to the antigens over 5.0 mm in diameter of induration at 48-72 hours was considered positive. RESULTS: A total of 138 subjects (18.8%) in 735 patients reacted to histoplasmin with 5.0-45.0 (9.1 +/- 4.3) mm indurations. Significant differences of positive skin reaction rates in normal subjects were found in Hunan, Jiangsu and Xinjiang (8.9% vs 15.1% vs 2.1%). The overall positive rate of patients was 25.5%. Patients with tuberculosis [31.7% (78/246)] had a significantly higher positive skin reaction rate in comparison with those suffering from pneumonia [17.7% (11/62)], lung cancer [20.9% (9/43)], chronic obstructive pulmonary disease [17.3% (9/52)] and other diseases [12.5% (4/32)] (P < 0.01). Of 562 cases, 292 cases (52.0%) reacted to PPD with indurations of 5-50 (13.7 +/- 4.9) mm in diameter, 63 cases (11.2%) reacted to both histoplasmin and PPD, while 38 cases (6.9%) reacted to histoplasmin but not to PPD. CONCLUSIONS: The data suggest that there is H. capsulatum herd infection in China. The infection rate in Southeast China is higher than that in the Northwest, and the infection rate of patients with pulmonary tuberculosis is higher than that of normal persons and other pneumonopathy patients.
[Identification of Cortex Cinnamomi and its confused species "yin xiang" by FT-Raman spectroscopy].
OBJECTIVE: To identify Cortex Cinnamomi and its confused species "Yin Xiang". METHOD: FT-Raman spectroscopy was used. RESULTS: Both Cortex Cinnamoni and its confused species had spectral features, and they could be easily identified. CONCLLUSION: The method is rapid, accurate, simple and non-destructive.
[Determination of ferulic acid absorbed into human serum from oral decoction of rhizoma chuanxiong and pharmacokinetic study of ferulic acid].
OBJECTIVE: To improve the HPLC method for determining ferulic acid(FA) in the human serum and to research FA clinical pharmacokinetics. METHOD: Serum concentrations of FA were determined by HPLC using methanol-water-acetic acid (40:59.7:0.3, v/v) as the mobile phase and the column packed with ODS (150 mm x 4.6 mm, 5 microns) as a fixed phase and the flow rate was 1.0 ml/min. FA was detected at 320 nm wave length. The internal standard was coumarin. The serum samples were treated by the water-boiling method. Peak of FA in serum was recognized by photodiode-array detection. RESULT: FA and internal standard were separated completely under the condition described as above. FA was linear in the range of (40.16-8032 ng/ml) (r = 0.9975). The CV was less than 10%, the average recovery was 100.3%, and the limit concentration in serum was 25.1 ng/ml. PK was in accordance with open bicameral model. CONCLUSION: This method can be applied to clinical pharmacokinetic study of FA.
[Intraoperative complications of endoscopic sinus surgery].
OBJECTIVE: To analyze the complications occurring in endoscopic sinus surgery (ESS). METHODS: The complications occurred in 25 cases from 307 patients who accepted ESS, performed by author, were reviewed. RESULTS: The complications were periorbital injury (n = 16), medial rectus injury (n = 2), optic nerve injury (n = 1), retrobulbar haematoma (n = 1), inferior turbinate feared partially (n = 2) and severe hemorrhage(n = 3). CONCLUSION: The causes of complications occurring in ESS were following: lack of experience, hemorrhage, blind operation, unsuitable instrument and reckless in manipulation. In addition, the complications, even serious complications, occurred in the hands of experienced surgeon.
[Direct determination of rhizoma cimicifuga by FTIR spectroscopy].
Fifteen samples of original plants of Rhizoma Cimicifuga were determined quickly and directly with the method of FTIR and comparing software. The results showed that the spectra of these samples were characteristic relying on the difference of chemical components and their content of related components. The difference of spectra among samples belonging to different families was distinct, and in different species with same genus too. To the same species, between two samples with different producing areas, or with same producing area but different collection date, the spectra were not obvious. This approach provide a quickly and accurately determination method of crude drug without extraction and separation.