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Biomedical subjects

W Liu

Publications and source records attributed to W Liu.

At least 721 records · Page 40Linked to original sources
PubMed1997

[Study on red cell enzymes and isoenzymes in patients with leukemia and myelodysplastic syndromes].

OBJECTIVE: To define the prevalence of acquired red cell enzymopathy in leukemia and MDS patients and explore its clinical significance. METHODS: Red cell enzymes (G6PD, 6PGD, PK, ENOL, ADA, PNP,ALD) activities and PK,ADA isoenzymes were assayed by the methods recommended by ICSH and PAGE electrophoresis. RESULTS: The prevalence rate of G6PD deficiency was 43.1%, and of PK deficiency was 27.8%, in leukemia and MDS patients. The prevalence rates of PK, G6PD and PNP deficiency in MDS patients were 50%, 48% and 39.1%, respectively, while of ADA, ENOL and ALD over production in MDS patients were 69. 6%, 40% and 30. 4%, respectively. PK activity was increased in CML, while the PK isoenzyme pattern was normal. Administration of antitumor antibiotics to AL decreased G6PD and 6PGD activities (P < 0.05). ADA2 was expressed in MNC of AML (M4 and M5) and in RBC of CMML, but not expressed in ALL (P < 0.001). CONCLUSION: Determination of enzymes may be used as prognostic parameters in CML,a predictor of antitumor drug resistance in acute leukemia, and a differential parameter between MDS-RA and aplastic anemia and between CML and CMML.

Adolescent↗
PubMed1997

[Cellular immunity in childhood iron deficiency anemia with recurrent respiratory infections].

OBJECTIVE: To examine interleukin-2 (IL-2) activity,serum soluble IL-2 receptor (sIL-2R) level and T lymphocyte subsets in peripheral blood from 63 childhood iron deficiency anemia (IDA) patients with recurrent respiratory infections(RRI). METHODS: IL-2 activity, sIL-2R level and T lymphocyte subsets were assayed by MTT, ELISA and APAAP, respectively. RESULTS: IL-2 activity, percentages of CD3+ and CD4+ cells as well as the ratio of CD4+/ CD8+ cells in the patients were significantly lower ( P < 0.01),while sIL-2R levels were higher than that in normal controls (P < 0.01). No significant change was found in the percentage of CD8+ cells. CONCLUSION: Cellular immunity was impaired in childhood IDA with RRI.

Anemia, Iron-Deficiency↗
PubMed1997

[Dual wavelength multiplication subtractive spectrophotometric determination of sulfadiazinum and trimethoprimum in compound sulfadiazine tablets].

This paper described the simultaneous determination of sulfadiazine (SD) and trimethoprim (TMP) in tablets co-Trimediazini by dual wavelength spectrophotometry multriplication subtractive method. This method was based on the measurement of both absorbance of standard solution of SD (8-14) x 10(-6)g/mL, TMP (1-2) x 10(-6)g/mL and sample solution at wavelength 242.5 nm and 228.0nm. The average recovery and RSD of SD and TMP were 100.60%, 0.33% and 98.27%, 1.58%, respectively (n=20). The method was simple, quick and results satisfactory.

Drug Combinations↗
PubMed1997

[Determination of chromium, manganese and nickel in six biological agents].

The determination of chromium, manganese and nickel in biological agents has obtained by flame atomic absorption spectrometry. The results show that three trace elements of body necessary are the most rich in ant factor injection liquid. The chromium content is slightly lower in the brain cell activator injection liquid, the nickel content is slightly lower in the shift factor injection liquid and the manganese is the lowest in the marrow factor injection liquid. In this paper, we have studied three trace element contents in six biological agents. It provides, useful data for clinical treatment to some trace-element-lacking diseases.

Chromium↗
PubMed1997

[Determination of caffeine and sodium benzoate contents in caffeine and sodium benzoate injection by P-matrix method].

The contents of caffeine and sodium benzoate injection may be determined by P-matrix method without separation of its components. BSAIC language is used for programming. The average recovery of caffeine is 100.0% and that of sodium benzoate is 99.95%. The variation coefficient of caffeine is 0.40% and that of sodium benzoate is 0.65%. On the basis of recovery rate and data observed it is concluded that this method is accurate, reliable, simple and rapid as compared with the standard pharmacopoeia regulations.

Caffeine↗
PubMed1997

Use of organotypic cultures of Corti's organ to study the protective effects of antioxidant molecules on cisplatin-induced damage of auditory hair cells.

HYPOTHESIS: Cisplatin causes the generation of reactive oxygen species (ROS), which interferes with the antioxidant defense system of Corti's organ and results in damage to the hair cells. BACKGROUND: Cisplatin is a widely used chemotherapeutic agent with the dose-limiting side effect of ototoxicity. Evidence is accumulating that cisplatin interferes with the antioxidant defense system of Corti's organ. METHODS: Organotypic explants of P-3 rat organ of Corti were the in vitro model system. Presence of intact auditory hair cells and stereocilia bundle integrity was assayed by phalloidin-FITC staining. Fluorescent dye probes detected H2O2 and intracellular thiol [e.g., glutathione (GSH)]. Spectrophotometric analysis determined antioxidant enzyme levels. RESULTS: There was a rapid dose-dependent cisplatin cytotoxicity in the explants after 48 h of exposure. An accumulation of H2O2 and a reduction of GSH levels were observed within cisplatin-exposed hair cells. L-buthionine sulfoximine, an inhibitor of GSH formation, enhanced cisplatin ototoxicity, whereas N6-(2-phenylisopropyl) adenosine, an adenosine agonist, elevated antioxidant enzyme levels and ameliorated cisplatin toxicity. The following molecules protected hair cells from cisplatin-induced damage: GSH; glutathione diethyl ester (GSHe); ebselen (EBS); 4-methylthiobenzoic acid (MTBA); and D-methionine (D-MET). EBS, MTBA, and D-MET in vitro protection correlates with in vivo protection in rats. CONCLUSIONS: Organotypic culture of Corti's organ has been validated as a model for studying cisplatin toxicity and for screening otoprotective molecules. Some of the events that contribute to cisplatin's ability to damage auditory hair cells are generation of ROS (e.g., H2O2), depletion of intracellular GSH, and interference with antioxidant enzymes within the cochlea. Agents that bolster the cochlea's antioxidant system can prevent cisplatin destruction of auditory hair cells. Identified protective agents may prove to be clinically useful in limiting or completely protecting from cisplatin ototoxicity.

Analysis of Variance↗
PubMed1997

Extremely low awareness of AIDS, sexually transmitted diseases and condoms among Dai ethnic villagers in Yunnan province, China.

OBJECTIVE: To assess the awareness of AIDS, other sexually transmitted diseases (STDs), condoms, sources of health information and HIV-related societal risks among Dai villagers in southern Yunnan Province, China. SUBJECTS AND METHODS: In November-December 1994, a cross-sectional descriptive study, comprising a questionnaire-based survey and focus group discussions, was conducted in three Dai villages in Mengla county; a total of 177 Dai villagers were interviewed in the survey and eight focus group discussions were held. Ethnographic observations provided a composite picture of HIV risks in the area. RESULTS: Only 18% of respondents had heard of AIDS, and only 25 and 28%, respectively, had heard of STDs or condoms. Furthermore, among these more aware groups, the level of knowledge was low and misconceptions were common. An ability to understand the official language (Mandarin) was the most important predictor of awareness of AIDS, other STDs or condoms. The sources of information in the three Dai villages sampled included TV, videos, radio and magazines, but only TV and videos had a large audience. Even so, these media were mostly in Mandarin and were not used in AIDS education. Travel outside of China was frequent; most villagers (77%) had traveled to Laos and 9% had traveled to Thailand. Societal risks of HIV transmission, such as an increasing incidence of STDs and an active sex industry, were observed in this area. CONCLUSIONS: Dai villagers in southern Yunnan Province had an extremely low awareness and knowledge of AIDS, other STDs and condoms. Given the high mobility of ethnic villagers to neighboring countries in Southeast Asia and the societal risks of HIV transmission in this area, there is an urgent need to provide accessible education about AIDS and other STDs. Suggestions regarding such health education and the implications of HIV policy-making are discussed.

Acquired Immunodeficiency Syndrome↗
PubMed1997

Some results on step-up tests for comparing treatments with a control in unbalanced one-way layouts.

The basic problem is to compare several treatments with a control in the standard unbalanced one-way layouts. Step-up tests were considered by Dunnett and Tamhane (1995, Biometrics 51, 217-227). In this paper, a method of calculating the critical values of step-up tests is proposed so that the Type I family wise error (FWE) is controlled at a prespecified level alpha. It is also pointed out that the equivalence of a step-up test and the test based on the correspondingly adjusted p-values requires implicitly a monotone property. A practical example is used for illustration.

Animals↗
PubMed1997

Predictive value of several signs of infection as surrogate markers for mortality in a neutropenic guinea pig model of Pseudomonas aeruginosa sepsis.

Infected, neutropenic animals are used as experimental models to evaluate the relative efficacies of antimicrobial agents and host-pathogen-antibiotic interactions. In the past, these models used death as the study end point. Because of the concern about use of death as an end point, we evaluated the accuracy with which various signs of infection predicted mortality in a neutropenic guinea pig model of treated and untreated Pseudomonas aeruginosa sepsis. The potential surrogate markers studied included ruffled fur, respiratory distress, diarrhea, hunched posture, lethargy, abnormal neurologic movements (twitching, paralysis of a limb), inappetence for > 48 h, the inability to ambulate, and the inability of a supine animal to stand. In addition, we evaluated whether percentage of weight loss or change in daily food and water consumption were predictive of mortality. Animals were inspected for these signs at least every 4 h during the day and every 8 h in the evening. In treated and untreated animals, 100% of subjects that were unable to ambulate or to rise from the supine position died (positive predictive value for death was 100% for either sign). Guinea pigs that could not rise from a supine position expired between 1 and 8 h after this sign was observed. Those that could not ambulate died between 4 and 40 h after that sign was observed. In treated and untreated animals, none of the survivors manifested either sign of disease (100% specificity for each sign). However, 59% of untreated and 69% of treated animals that were ambulatory were found dead at the next observation period, underscoring the rapidity with which this infection progresses to death when it enters its final stage. No other signs of infection distinguished animals that survived or died. Thus, the inability of neutropenic, infected guinea pigs to rise from a supine position and the inability to ambulate were the only signs that accurately predicted death and, therefore, are the only signs that can be used as surrogates for death in this experimental model of P. aeruginosa sepsis.

Animals↗
PubMed1997

Functional morphology of the spinal canal after endplate, wedge, and burst fractures.

Changes in the canal diameter during physiological motions are important considerations in the treatment of patients who have a burst fracture with the presence of bony fragments, but without neurologic deficit. In this in vitro study, the changes in the soft-canal diameter of the thoracolumbar region, when intact and after different fractures, was investigated under several different loading conditions. The soft-canal diameter was clearly identified on the lateral radiographs by attaching a series of steel balls to the posterior longitudinal ligament and ligamentum flavum in the midsagittal plane. Endplate, wedge, and burst fractures were produced incrementally in 19 three-vertebrae human cadaveric spine specimens by high-speed impacts. After each injury, a series of functional lateral radiographs were taken. The minimal canal diameter (MCD) was obtained by digitizing the images of the steel balls on radiographs using a custom-designed computer program. In the intact specimens, the MCD at the disc level changed significantly in flexion, extension, and compression, when compared with the MCD in the unloaded neutral position. However, the changes were small. The MCD after endplate and wedge fractures changed in a similar way. However, after the burst fracture, the MCD at the bone fragment level increased remarkably by a distraction force. It also significantly improved by an anterior shear force in comparison to the corresponding MCD in the neutral position. However, this change was smaller than the change due to the distraction force.

Biomechanical Phenomena↗
PubMed1997

Evolutionary regularity of acetabular dysplasia after reduction of developmental dislocation of the hip.

OBJECTIVE: To observe the developmental changes of the acetabulum after reduction of developmental dislocation of the hip and require evolutionary regularity of acetabular dysplasia. METHODS: A follow-up in an average of 7.4 years was carried out in 117 patients (161 hips) with developmental dislocation of the hip after reduction. By the series of X-ray films, acetabular index, acetabular-head index, Sharp's angle, ACM angle (Idelberger's angle) and anteversion were observed. At the same time, centre-head distance discrepancy was measured. RESULTS: Acetabular index returned to normal gradually as the time went by and significantly within one year after the reduction of developmental dislocation of the hip. The process of recovery was nearly stable three years later. Acetabular index in the dysplasia group was above 39 degrees before reduction and decreased slowly after the reduction. However, it was still up to 30 degrees after 3 years observation. The value of centre-head distance discrepancy decreased gradually as the years went by after reduction. CONCLUSIONS: If acetabular index before reduction is above 39 degrees and is still up to 30 degrees three years after reduction, acetabular dysplasia can be diagnosed.

Acetabulum↗
PubMed1997

[Experimental study on direct volume reconstruction].

Application of DVR is investigated with the X-ray equipment under single circle imaging geometry. A real volume model that consists of aluminum bar, lucite and air bar is designed. A prototype imaging system that includes X-ray cone-beams ource, rotating system, fluorescent screen, image intensifier, TV camera, image acquisitor and microcomputer is constructed. The experimental results show that DVR with the current simple X-ray equipment is of interests and values.

Image Processing, Computer-Assisted↗
PubMed1997

[Molecular diagnosis of beta-thalassemia intermedia].

OBJECTIVES: To analyze the molecular abnormalities of beta-thalassemia intermedia and contribute to the knowledge of the molecular diagnosis and prenatal diagnosis of this disorder. METHODS: In 14 patients with beta-thalassemia intermedia, we analyzed the hematologies, alpha, beta and gamma globin gene organization and structure as well as globin gene biosynthesis by Southern blot hybridization, multiplex allale specific PCR (MAS-PCR), DNA sequencing and micro-globin chain biosynthetic assay. Moreover, alpha globin gene organization was studied in 250 cord blood specimens. RESULTS: Of the 14 patients, 4 were found to be beta-thalassemia heterozygotes combined with rightward cross-over or/and leftward cross-over triplicated haplotype of alpha-globin gene loci (alpha alpha alpha anti3.7 or/and alpha alpha alpha anti4.2), 3 were compound heterozygotes for beta-thalassemia combined with alpha-thalassemia 1 or 2, one was identified to be a compound heterozygote for beta-thalassemia combined with G gamma promotor-158 (C-->T) mutation. The data of the alpha globin gene organization in 250 cord blood specimens showed that 8 of the 500 tested chromosomes (1.6%) were abnormal: 3 were alpha alpha alpha anti3.7, 4 were alpha -3.7, and one was --SEA. CONCLUSION: In addition to beta-thalassemia homozygote or compound heterozygotes with alpha thalassemia, the conjunctive abnormalities of beta-thalassemia heterozygote with alpha-globin gene triplication was another major cause of beta-thalassemia intermedia.

Adolescent↗
PubMed1997

[Serotyping of hemorrhagic fever with renal syndrome in Hubei province].

Ninety-two serum specimens, positive for antibodies against hemorrhagic fever with renal syndrome (HFRS) virus in initial screening with immunofluorescence assay technic (IFAT), were serotyped with micro cell pathogenic effects neutralization test based on preliminary epidemiological classification of epidemic foci of HFRS throughout the province to find out serological evidence of HFRS typing in Hubei Province. It was found that 48 of the specimens were belonged to Type I (HTN) accounting for 52.18 percent, 29 Type II (SEO) for 31.52 percent, and 15 undefined for 16.30 percent. Hubei Province was classified serologically as a mixed prevalent area with Type I as its major component, but all serotypes in different sub-areas have their own features and those in the old epidemic foci were more complex. It indicated that it was better to use a bivalent HFRS virus vaccine, or a single-valent vaccine consistent with local serotype. Serotyping of local HFRS conformed basically to that of epidemiological classification. Local HFRS should be serotyped periodically due to continuous changes in types of foci. Attention to reactions of vaccine immunization should be paid during observation of the effectiveness of the vaccine.

China↗