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Biomedical subjects

Y Luo

Publications and source records attributed to Y Luo.

At least 361 records · Page 20Linked to original sources
PubMed1996

[Packing of the chromatin fibers and the distribution of RNP in BK chromosomes].

The packing of the chromatin fibers and the distribution of RNP in bovine kidney (BK) chromosomes were studied by the combination of transmission, scanning electronic microscopy (TEM, SEM) and cytochemical electronic microscopy (CCEM). The results showed that BK chromosomes reveal a multiple double strand helical structure. The central axial area of each chromatid is a low electronic density region or chromatin free compartment, in which there are lots of RNP. In the peripheral chromatin region the RNP is distributed among the chromatin fibers and continued with that of the central region. The density of the central RNP is more than that of the peripheral RNP, which indicates that RNP is not uniformly distributed in chromosome.

Animals↗
PubMed1996

[Correction of alveolar cleft by bone graft in the patients with cleft lip and palate].

Treatment of alveolar cleft using bone graft has been developed to the stage of team approach. We summarized the clinical material of 80 cases treated by bone grafting. This study revealed that bone grafting for cleft alveolar repair was an effective procedure valuable to be popularized. Properly forming the bed of bone grafting and perfectly closing the recipient site is the key to a successful operation. Patients should accept orthodontic treatment before and after the operation. We discuss the indications, technique, result evaluation and management before and after the operation.

Adolescent↗
PubMed1996

[A double column double pH solid phase extraction and capillary GC/FID method for rapid simultaneous determination of acidic and basic drugs in human plasma].

A capillary gas chromatographic method for the rapid simultaneous identification and quantitation of acidic and basic drugs in human plasma is presented. A special double column solid phase extraction device was designed, in which two X-5 resin columns can extract drugs at different pH. The detection limits for acidic and basic drugs can reach 0.5 microgram.ml-1, while the time needed is only half of that when using commercial solid phase extraction cartridges.

Anesthetics, Local↗
PubMed1996

[Measurement of maximal inspiratory flow and forced inspiratory capacity and its clinical application].

The methods of measuring the maximal inspiratory flow (V(imax)) and the forced inspiratory capacity (FIC) via forced inspiratory capacity-time curve (FIC-t curve) were investigated. Both V(imax) and FIC were measured in 35 normal subjects and 89 patients with chronic obstructive pulmonary disease (COPD). The maximal inspiratory pressure (MIP) was measured simultaneously at function residual capacity(FRC) level by modified Black Method. The results showed that there is a linear relationship between MIP and V(imax) or FIC in both normal subjects and patients with COPD. Normal subjects had a mean V(imax) and FIC much higher than those of patients with COPD. The values of V(imax) and FIC in patients were also, significantly correlated to the severity of COPD. So we suggest that both V(imax) and FIC be used as clinical indices to reflect inspiratory muscles strength.

Adult↗
PubMed1996

[Systematic analysis of basic drugs in plasma using X-5 solid-phase extraction GC-FID and GC-MS].

A systematic determination method for 34 basic drugs in human plasma is described. Drugs were extracted from plasma at pH 10 using X-5 resin as adsorbent, then identified and quantitated by capillary GC-FID and GC-MS. The detection limits for most drugs are in the range of 0.5-2.0 micrograms.ml-1. Precision and linearity of the method are satisfactory for clinical toxicological applications.

Analgesics, Opioid↗
PubMed1996

[Analysis of telomere restriction fragments in human astrocytomas and glioblastomas].

OBJECTIVES: To analyse the length of telomere restriction fragments (TRF) in different type of human astrocytomas as well as normal brain tissues and to evaluate the correlation of telomere status and tumor progression. METHODS: DNAs extracted from normal and tumor samples were studied with Southern blot analysis, using (TTAGGG)4 probe specific for human telomeric sequences. RESULTS: The lower portion of TRFs of astrocytoma type I, II and III was shortened gradually in comparison with that of normal brain tissues: both uper and lower portions of TRFs in 12 cases of glioblastoma multiformes studied were lost distinctively. However, no obvious length difference of TRFs could be detected between primary and recurrent glioblastomas. CONCLUSIONS: Telomere reduction is one of the important genetic events during transformation of astrocytomas. Telomere repair mechanism may be initiated in glioblastoma cells which may, therefore, maintain a relative stabitity of TRFs and permit a constitutive proliferation of those malignant cells.

Astrocytoma↗
PubMed1996

[Gene expression of HGF and its receptor in experimental hepatomas].

OBJECTIVE: To understand the regularity of changes of gene expression about HGF and its receptor (HGFR) in experimental hepatomas model of Wistar rats and the relationship between this change and tumor biological behaviour. METHODS: The gene expression of HGF and HGFR in the canceration course of rats was determined by using experimental hepatomas model of Wistar rats established by diethylnitrosamine (DENA), with digoxigenin-labled probe. RESULTS: The positive expression of HGF and HGFR was found in rats liver tissues, but it was different in distinct stages. The positive expression of HGF was the highest in precirrhosis stage, and next in the cirrhosis stage. The canceration stage was the same as in the normal group. The positive expression of HGFR was gradually increased following the canceration course and the canceration stage was the highest, but we didn't find the expression of HGFR in normal liver tissues. CONCLUSIONS: There are close relations between the gene expression of HGF and HGFR and evolution course during the canceration of rats liver. HGF and HGFR systems play an important role in regulating tumor growth and metastasis.

Animals↗
PubMed1996

[A study of loss of heterozygosity and mRNA expression at DCC locus in gastric cancers].

To evaluate the role of DCC gene alteration in the development and progression of gastric cancer, loss of heterozygosity (LOH) and mRNA expression of DCC gene was examined in surgically resected gastric cancer specimens using PCR-RFLP and RT-PCR analyses. LOH was detected in 18 (35.3%) of 51 informative cancers specimens. The frequency of LOH in stages III and IV (50.0%) was significantly higher than that in stages I and II (14.3%, P < 0.05%), but LOH was not correlated to histological types, tumor size, invasion depth and lymph node metastases. Expression of DCC mRNA in 26/51 cases was examined and the DCC expression was lost in 8/26 (30.7%) cancer, and no significant correlation was found between loss of DCC expression or LOH and clinico-pathologic parameters. LOH and loss of expression at DCC gene occur frequently in gastric cancers, LOH at DCC locus is a late event.

Gene Deletion↗
PubMed1996

[Cetirizine improves the resistance of airway and pulmonary function in patients with asthma].

The objective of this study was to investigate the possible anti-asthma role of Cetirizine. Forty asthmatics were randomly divided into two groups. The experimental group had 30 patients. Among them were 10 patients with simple asthma, 5 patients complicated by mild emphysema, 6 patients complicated by moderate emphysema and 9 patients complicated by severe emphysema. Vit-C (control) group had 10 cases, including 2 cases of simple asthma, 6 cases complicated by mild emphysema and 2 cases complicated by moderate emphysema. All patients had a single oral dose of 5 mg Cetirizine or 0.1 g Vit-C blindly. Before and 0.5, 1 hour after their medicines, the resistance of airway (Raw), sGaw and MEFV were examined in all patients on 6200 Plethysmograph. The measured values showed a significant improvement of Raw and sGaw after administration of Cetirizine. In half an hour after Cetirizine, the Raw decreased by 20.408%, and sGaw increased by 28.249%. In one hour after Cetirizine, Raw further decreased by 24.34% and sGaw increased by 41.153% (P < 0.001). The FVC in MEFV increased by 4.96% (P < 0.02) in one hour after Cetirizine, but other parameters in MEFV curve (PEF, FEV1, MMEF) had no significant changes. All parameters in control group had no significant changes (P > 0.05). The results indicate that Cetirizine could decrease Raw in asthmatics, improve their lung ventilatory function. Cetirizine is a new H-receptor antagonist usually used as anti-inflammatory and allergy suppression medication. It is shown that Cetirizine is a promising anti-asthma agent in treating bronchial asthma.

Adult↗
PubMed1996

[Diagnostic value of exercise diffusion capacity test on diffuse pulmonary fibrosis].

Diffusion capacity for carbon monoxide of the lung (DLCO) before-and-after exercise test and 5 routine pulmonary function tests were conducted in 16 patients with diffuse pulmonary fibrosis (DPF), 19 patients with interstitial pneumonia (IP), 17 patients with COPD, and 22 normal subjects. The data showed: in normal subjects the DLCO after exercise increased significantly compared with before (P < 0.001). But in DPF group the DLCO before exercise was below the normal range, and it went down further after exercise, the decreasing rate being 17.95% (P < 0.001). The DLCO in IP and COPD groups did not significantly change before and after the exercise. Two cases of interstitial pneumonia, who had a reduced DLCO after exercise, were followed up for 0.5-1.0 year, and both patients developed into DPF by that time. The results suggest that the DLCO measure before and after exercise test may have important value for DPF diagnosis, and a reduced DLCO after exercise test in IP patients may warn the development from IP into DPF.

Adult↗
PubMed1996

[Value of measuring resistance of airway for diagnosis of asthma].

Resistance of airway (Raw), sGaw and Maximal expiratory flowvolume curve (MEFV) were measured in 35 normal subject, 43 patients with remission asthma and 100 patients with remission chronic bronchitis (some complicated by obstructive emphysema). The measured values showed that in simple asthma Raw was significantly higher than that in normal subject and in patients with chronic obstructive bronchitis (COB), but MEFV was in normal range. In chronic bronchitis the value of Raw was higher than that in normal subject, but lower than that in asthma (0.05 > P > 0.02); however the FEV1, MMEF, V75 in the curve of MEFV were significantly decreased at the stage of COB, with the most remarkable decrease in MMEF. The results suggest that Raw is a sentitive test for diagnosis of simple asthma, in addition to MEFV measurement; it may be helpful for differential diagnosis of simple asthma and COB and may has potential value for clinical practice.

Adult↗
PubMed1996

[Alveolar reconstruction in patients with cleft palate].

Repair of the alveolar cleft is one important procedure in team approach of cleft palate. The present paper reports 110 cases repaired by bone grafting. Indications, technique, results evaluation and management before and after operation are discussed. The study proves that bone grafting is effective to repair alveolar cleft and should be popularised. Properly forming the bed of bone grafting and perfectly closing the receipt site are the keys of success. Patients should be treated orthodontically before and after operation. In selection of donor site, the patient's age, tooth age, width of cleft and quantity of bone to be grafted should be considered.

Adolescent↗
PubMed1995

A specialized pathway affecting virulence glycoconjugates of Leishmania.

For virulence and transmission, the protozoan parasite Leishmania must assemble a complex glycolipid on the cell surface, the lipophosphoglycan (LPG). Functional complementation identified the gene LPG2, which encodes an integral Golgi membrane protein implicated in intracellular compartmentalization of LPG biosynthesis. Ipg2- mutants lack only characteristic disaccharide-phosphate repeats, normally present on both LPG and other surface or secreted molecules considered critical for infectivity. In contrast, a related yeast gene, VAN2/VRG4, is essential and required for general Golgi function. These results suggest that LPG2 participates in a specialized virulence pathway, which may offer an attractive target for chemotherapy.

Amino Acid Sequence↗
PubMed1995

Detection of creatinine by a designed receptor.

An artificial receptor has been designed to bind creatinine with a color change (chromogenic response) caused by proton transfer from one end of the receptor to the other. The receptor was synthesized and found to extract creatinine from water into chlorocarbon solvents. The color change in the organic layer is specific for creatinine relative to other organic solutes, and it is selective for creatinine relative to sodium, potassium, and ammonium ions. The chromogenic mechanism is revealed by x-ray crystal structures of creatinine, the free receptor, and the complex, showing "induced fit" binding resulting from electronic complementarity between host and guest.

Acridines↗