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Biomedical subjects

J Yu

Publications and source records attributed to J Yu.

At least 415 records · Page 23Linked to original sources
PubMed1999

[Study on stable unified disinfectant capable of releasing chlorine dioxide].

Chlorine dioxide is a new type of forceful disinfectant, but it cannot be stored and transported as a gas and is very toxic. In this paper, a stable unified disinfectant capable of releasing chlorine dioxoide was introduced. This disinfectant was stable in dry state and could produce chlorine dioxide when it contacted with water. Its solution containing 3.3 mg.L-1 chlorine dioxide could kill 100% of B. subtilis var. niger spores after exposure for 5 minutes. Its solution containing 434 mg.L-1 chlorine dioxide could destroy 100% of HBsAg after exposure for 30 minutes. The content of chlorine dioxide in this disinfectant powder decreased by about 12% following storage at 56 degrees C for 14 days. It was essentially non-corrosive to stainless steel and moderately corrosive to carbon steel.

Animals↗
PubMed1999

[Effects of tea polyphenols on microcirculation and antioxidation in aircrew].

OBJECTIVE: To study the effects of tea polyphenols (TP) on bulbi conjunctiva microcirculation (BCM) and antioxidation in aircrew and find out the proper antioxidant for the health protection of aircrew. METHOD: Fourty healthy aircrew were divided into TP group (TP 600 mg/d.po) and control group (placebo) randomly. The effects of TP on microcirculation and antioxidation in aircrew were tested after 20 days. RESULT: Red blood cell (RBC) superoxide dismutase (SOD) activity and GSH-PX (Whole blood glutathione peroxidase)/MDA (serum malondialdehyde) ratio in TP group were significantly higher than those in control (P<0.01), and serum MDA level was significantly decreased after TP administration (P<0.05). The numbers of capillaries and blood flow in micrangium were significantly increased, RBC aggregation, ischemia area and A (arteriole)/V (venule) ratio were remarkably decreased in TP group (P<0.01). The total integral value of microcirculation in TP group was significantly reduced in comparison with that in the control group. CONCLUSION: TP can significantly increase the antioxidative ability of aircrew, decrease the BCM disturbance and improve the microcirculatory function.

Adult↗
PubMed1999

[Studies on chemical constituents of seeds of Desmos chinensis Lour].

OBJECTIVE: To investigate the chemical constituents of Desmos chinensis. METHOD: Various column chromatographic techniques were employed for the isolation and purification of constituents from the ethanol extract. The structures were elucidated by spectral analysis. RESULT: Eleven compounds were isolated and identified as lawinal(1), desmosal(2), desmethoxymatteucinol(3), unonal(4), isounonal(5), desmosflavone(6), allantoic acid(7), succinic acid(8), daucosterol(9), beta-sitosterol(10) and stearic acid(11). The structures of compounds 1 and 2 were reconfirmed by NOEDS technique. CONCLUSION: Compound 2 is a new natural product and 7, 8 and 9 were found from this plant for the first time.

Annonaceae↗
PubMed1999

[Flavonoids from Beijing propolis].

OBJECTIVE: To separate and identify the active flavonoids from Beijing Propolis. METHOD: The flavonoids were isolated by column chromatography with silica gel and polyamide, purified with Sephadex LH-20, and elucidated on the basis of NMR, MS, UV, IR and CD spectra. RESULT: Six kinds of flavonoids were obtained and elucidated as I: pinostrobin, 5-hydroxy-7-methoxy-flavanone; II: pinocembrin, 5, 7-dihydroxy-flavanone; III: tectochrysin, 5-hydroxy-7-methoxy-flavone; IV: chrysin, 5, 7-dihydroxy-flavone; V: izalpinin, 5-hydroxy-7-methoxy-flavonol and VI: galangin, 5, 7-dihydroxy-flavonol. CONCLUSION: Compounds I, II, III and V were found for the first time from Beijing Propolis.

Flavanones↗
PubMed1999

[Quantitative determination of vanillic acid in rhizoma Picrorhizae by TLC-scanning].

OBJECTIVE: To establish a method to determine the content of vanillic acid in Rhizoma Picrorhizae. METHOD: The content was determined by dual wavelength TLC-scanning. RESULT: The peak area of vanillic acid is reproducible in 4 hours; recovery 96.5%; RSD-3%; RSD of duplicate experiment-5%. CONCLUSION: A thin-layer chromatographic scanning method has been developed for determining the content of vanillic acid. The method is reproducible, workable and reliable.

Chromatography, Thin Layer↗
PubMed1999

[Evaluation of N staging of cervical lymph nodes with positive palpation in laryngeal carcinoma].

OBJECTIVE: To evaluate N staging of cervical lymph nodes with positive palpation objectively. METHOD: Serial sections of lymph nodes of neck dissections with transparent methods were observed under light microscope. RESULT: 81 lymph nodes with pathological metastases were verified in 100 patients with 114 palpation positive lymph nodes. The correspondent rate was 71.1%. The correspondent rate of clinical N via pathological N staging was N1 35.6%, N2a 25.0%, N2b 58.3%, N2c 75.0%, N3 100.0% respectively. CONCLUSION: N staging judged only by palpation is not sufficient in clinic. It should be combined with other examinations.

Carcinoma, Squamous Cell↗
PubMed1999

[A study on distribution modeling of the electrical stimulation under surface nerve stimulation electrodes for somatosensory evoked potential].

The detection of somatosensory evoked potential (SEP) has been an important approach to determining the function of spinal cord and peripheral nerve. Transepidermal Electrical Neuromuscular Stimulation (TENS) on the posterior tibial nerve for SEP is one of the applications and can improve the effectiveness. This paper theoretically studies the distribution of potential field and current density field for human tissue under TENS. A mirror method is used and the analytical solution of the potential distribution is obtained.

Algorithms↗
PubMed1999

[Evaluation of intraoperative ultrasonography for hepatic neoplasm in surgery].

OBJECTIVE: The purpose of this study was to evaluate the impact of intraoperative ultrasound (IOUS) on the management of patients with neoplasms of the liver. METHODS: Forty-nine patients received operations for liver tumors were examined intraoperatively with 5.0 MHz special ultrasound transducers during surgical exploration of the abdomen. Preoperative imaging studies including percutaneous ultrasound (n = 49), magnetic resonance imaging (n = 11), and computed tomography (n = 34) were taken to compare with intraoperative ultrasonography for the evaluation. RESULTS: Sensitivity for detection of hepatic neoplasms showed in intraoperative ultrasound, percutaneous ultrasound, magnetic resonance imaging and computed tomography as 100%(23/23), 74%(17/23), 74%(14/19), and 75%(6/8) respectively. Specificity showed 100%(26/26), 100%(26/26), 93%(14/15), and 67(2/3) respectively. CONCLUSIONS: Intraoperative ultrasound was the most sensitive and specific method for detection and surgery of liver neoplasms, especially the occult neoplasms and small size lesion (< 2 cm).

Aged↗
PubMed1999

[Pathologic feature of occult lymphatic metastasis in supraglottic carcinoma].

OBJECTIVE: To study the pathologic features of occult lymphatic metastasis in patients with supraglottic carcinoma and its implication in treatment. METHODS: Serial sections of 153 neck dissection specimens in 100 patients with supraglottic carcinoma were studied under microscope. RESULTS: Clinically negative nodes had been proved histologically positive in 58 specimens (38%) and 51 occult nodes, size ranged from 0.5 cm to 2.6 cm with average of 1.1 cm. The distribution of metastastic lymph nodes was 1 in level I (2%), 37 in level II (73%), 12 in level III(23%) and 1 in level IV(2%). Among the 51 nodes, 21(41%) were in early stage, 18 (35%) in growth stage, 7(14%) in full stage, 5(10%) were extracapsular. CONCLUSION: Occult metastasis rate of supraglottic carcinoma is as high as 38%, selective neck dissection is recommended for the surgical treatment of this disease.

Adult↗
PubMed1999

Intraoperative ultrasound for hepatic neoplasm during surgery.

OBJECTIVE: The purpose of this study was to determine the impact of intraoperative ultrasound (IOUS) on the management of patients with neoplasms of the liver. METHODS: Forty-nine patients operated on for liver or other pathologic processes were examined intraoperatively with 5.0 MHz special ultrasound transducers during surgical exploration of the abdomen. Subjects were evaluated because of known or suspected disease of the liver. Preoperative imaging studies included percutaneous ultrasound (n = 49), magnetic resonance imaging (n = 11), and computed tomography (n = 34). Intraoperative evaluation on all patients included inspection, bimanual palpation, and ultrasonography. Comparison between preoperative imagings and IOUS were analysed. RESULTS: Sensitivity for detection of hepatic neoplasms showed in intraoperative ultrasound, percutaneous ultrasound, magnetic resonance imaging and computed tomography as 100% (23/23), 74% (17/23), 74% (14/19) and 75% (6/8). Specificity showed 100% (26/26), 100% (26/26), 93% (14/15) and 67 (2/3). In seven patients (14%), the neoplasms were not found by inspection, bimanual palpation, and identified only by IOUS. CONCLUSIONS: Intraoperative ultrasound is the most sensitive and specific method for detection and surgery of liver neoplasms, especially the occult neoplasms and small size lesion (< 2 cm).

Carcinoma, Hepatocellular↗
PubMed1999

[The investigation for lysozyme conformation changes in deuteromethanol solution by FT-Raman spectrometer].

Lysozyme conformation in deuteromethanol-deuteroxide solution has been studied by FT-Raman spectrometer. By using amide I mode in the Raman spectra and curve fitting method, information of Lysozyme's secondary structure is easily detected in details, and tertiary structure changes can be suggested by relative intensity changes of some bands. It is concluded that lysozyme conformation may be changed to loose structure with incrasing deuteromethanol concentration, and it seems like that increasing loose beta-sheet content lead to the gel's appearing in the solution.

Methanol↗
PubMed1999

[A quantitative study on secondary structure of proteins by FT-Raman spectroscopy].

In this work, proteins have been scanned by FT-Raman spectrometer. Deconvolved spectra, second derivative or fourth derivative spectra were employed to determine positions of individual components. Curve-fitting procedures were carried out to amide I band of original spectra. The broad band was resolved into several components. The resolved band components were assigned to specific protein conformations. The areas of individual components are used to estimate the percentage of the relative secondary structure. Results are in reasonable agreement with data obtained by other methods.

Animals↗
PubMed1998

Characterization and chromosomal mapping of the human gene for SFT, a stimulator of Fe transport.

Hemochromatosis is the most common genetic disorder known in man and results in progressive tissue deposition of iron leading to cirrhosis of the liver, hepatic carcinoma, congestive heart failure, endocrinopathies, and premature death. SFT (stimulator of Fe transport) is a newly discovered transport protein that facilitates uptake of iron. Recent studies have demonstrated that although SFT expression is reciprocally regulated in response to cellular iron levels, it is aberrantly upregulated in the liver of hemochromatosis patients, indicating that enhanced SFT expression contributes to the etiology of this disease. Here we report the molecular cloning and characterization of the human gene for SFT. FISH analysis maps the SFT gene to human chromosome 10q21. PCR analysis indicates 1000 nucleotides of intervening intron sequence near the 3' end of the coding region for SFT. Based on DNA sequence analysis of the additional 5' untranslated region obtained from the genomic clone, SFT lacks known metal-regulated transcriptional or translational control elements. These studies provide the basis for future elucidation of the mechanisms that control SFT expression in order to discover how this regulation is lost in hemochromatosis.

Base Sequence↗
PubMed1998

Expression of SFT (stimulator of Fe transport) is enhanced by iron chelation in HeLa cells and by hemochromatosis in liver.

SFT (stimulator of Fe transport) is a novel transport protein that has been found to facilitate uptake of iron presented to cells as either Fe(II) or Fe(III). When HeLa cells are exposed to the iron chelator desferrioxamine, levels of SFT mRNA increase in an actinomycin D-sensitive manner. In contrast, cells exposed to high levels of iron down-regulate SFT expression in a time-dependent and reversible fashion. Thus, homeostatic regulation of SFT expression not only ensures that sufficient levels of iron are maintained but also limits excessive assimilation to prevent potentially harmful effects of this toxic metal. The unexpected observation that SFT transcript levels are up-regulated in hemochromatosis patients therefore suggests that enhanced SFT expression contributes to the etiology of this iron overload disorder.

Biological Transport↗
PubMed1998

Regular physical exercise corrects endothelial dysfunction and improves exercise capacity in patients with chronic heart failure.

BACKGROUND: The purpose of this study was to determine the effects of systemic exercise training on endothelium-mediated arteriolar vasodilation of the lower limb and its relation to exercise capacity in chronic heart failure (CHF). Endothelial dysfunction is a key feature of CHF, contributing to increased peripheral vasoconstriction and impaired exercise capacity. Local handgrip exercise has previously been shown to enhance endothelium-dependent vasodilation in conduit and resistance vessels in CHF. METHODS AND RESULTS: Twenty patients were prospectively randomized to a training group (n=10, left ventricular ejection fraction [LVEF] 24+/-4%) or a control group (n=10, LVEF 23+/-3%). At baseline and after 6 months, peak flow velocity was measured in the left femoral artery using a Doppler wire; vessel diameter was determined by quantitative angiography. Peripheral blood flow was calculated from average peak velocity (APV) and arterial cross-sectional area. After exercise training, nitroglycerin-induced endothelium-independent vasodilation remained unaltered (271% versus 281%, P=NS). Peripheral blood flow improved significantly in response to 90 microg/min acetylcholine by 203% (from 152+/-79 to 461+/-104 mL/min, P<0.05 versus control group) and the inhibiting effect of L-NMMA increased by 174% (from -46+/-25 to -126+/-19 mL/min, P<0.05 versus control group). Peak oxygen uptake increased by 26% (P<0.01 versus control group). The increase in peak oxygen uptake was correlated with the endothelium-dependent change in peripheral blood flow (r=0.64, P<0. 005). CONCLUSIONS: Regular physical exercise improves both basal endothelial nitric oxide (NO) formation and agonist-mediated endothelium-dependent vasodilation of the skeletal muscle vasculature in patients with CHF. The correction of endothelium dysfunction is associated with a significant increase in exercise capacity.

Blood Flow Velocity↗