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Biomedical subjects

B Yu

Publications and source records attributed to B Yu.

At least 91 records · Page 5Linked to original sources
PubMed1998

Indirect laser photoacoustic detection for trace samples on membranes.

An indirect laser photoacoustic technique is described. The basic principle, the experimental set-up and the influencing factors are discussed in detail. This method was used to quantify phenylamine, arginine and methylene blue on membranes. The linear ranges of the calibration curve are up to two orders of magnitude. With 1 microliter of sample solution, the detection limits are 0.25, 1.52 and 0.14 pmol for phenylamine, arginine and methylene blue, respectively.

Absorption↗
PubMed1998

Effect of different sources of dietary fibre on growth performance, intestinal morphology and caecal carbohydrases of domestic geese.

1. The aim of this study was to examine the effects of dietary fibre sources on growth and on the development of the gastro-intestinal tract in growing geese. 2. Six-week-old female White Roman geese were divided at random into 6 groups with 6 dietary treatments. Diets were isoenergetic and isonitrogenous and contained alfalfa meal, barley bran, rice hulls, cellulose, pectin or lignin as the major dietary source of fibre. 3. Food intake was significantly higher in the barley bran group than in the other groups. Both daily weight gain and food conversion of the pectin and alfalfa meal groups were lower than those of the other groups. 4. In the 9-week-old geese, the relative weight and the length of the small intestine did not significantly differ among treatment groups. However, the relative weight was significantly lightest and the caecal length was significantly shortest (P < 0.05) in the pectin group. 5. Activities of amylase and cellulose hydrolases of the caecal contents were also highest in the pectin group. 6. From SEM micrographs, no morphological damage of the villi was observable in the different intestinal segments of the geese in any of the treatments.

Amylases↗
PubMed1998

Capillary electrophoresis: new technology for DNA diagnostics.

New innovations in the diagnostic laboratory achieve their full potential when they can be automated. Increasingly molecular biology (DNA) techniques are being utilised in traditional pathology disciplines, as well as the more recent ones of cytogenetics and molecular genetics. Molecular biology was first exploited for diagnostic purposes when Southern blotting became established. However the time-consuming nature of the methodology, as well as the skills required, made it difficult for Southern blotting to be used routinely in the service laboratory. Subsequently the invention of PCR facilitated the approach to DNA diagnostics. Today PCR in commercial or home-made kits is used for a range of procedures. The steps required to amplify DNA with PCR can also be fully automated. However the analysis of PCR products, which frequently requires slab gel electrophoresis and toxic chemicals or radioisotopes for visualisation, remains difficult to automate. An alternative way for analysing PCR products is now available through capillary electrophoresis. With this technique, automation can be extended to sample loading, electrophoresis and data analysis. The use of toxic chemicals or radioisotopes can be avoided.

Chromosome Mapping↗
PubMed1998

An instrumented wheel for kinetic analysis of wheelchair propulsion.

An instrumented wheel system for three-dimensional kinetic analysis of upper extremity during wheelchair propulsion has been designed and validated. This system allows the direct measurements of three-dimensional dynamic forces and moments on the handrim during wheelchair propulsion in a laboratory setting as well as in the field. Static loading tests showed a high linearity and little drift (coefficient of determination, r2 > 0.999). Under dynamic loading, the instrumented wheel provided the well-matched measurement forces and moments with the predicted values from the inverse dynamic method using video-based kinematic data (correlation coefficient, p > 0.97). The three-dimensional handrim forces and moments during wheelchair propulsion by a non-disabled subject were demonstrated.

Biomechanical Phenomena↗
PubMed1998

Counselling issues in familial hypertrophic cardiomyopathy.

To illustrate the variable clinical presentations and rates of progression in familial hypertrophic cardiomyopathy (FHC), phenotypes and genotypes were compared in three FHC families with different genetic defects. In the first family, the FHC abnormality was a protein truncating mutation (Gln969X) in the cardiac myosin binding protein C gene. The second family had a missense change (Asn755Lys) in the same gene. A missense mutation (Arg453Cys) in the cardiac beta myosin heavy chain gene was present in the third family. Penetrance associated with the Gln969X defect was 27% in the age range 0 to 40 years. This was considerably less than the 93% penetrance (0 to 40 years) observed in the two families with missense mutations. The variable penetrance in FHC, as well as the unpredictability of sudden cardiac death, complicates clinical diagnosis and management, including genetic counselling. Although a genetic disease with a predominantly adult onset, there are counselling issues in FHC which set it aside from other adult onset disorders.

Adolescent↗
PubMed1998

Molecular pathology of familial hypertrophic cardiomyopathy caused by mutations in the cardiac myosin binding protein C gene.

DNA studies in familial hypertrophic cardiomyopathy (FHC) have shown that it is caused by mutations in genes coding for proteins which make up the muscle sarcomere. The majority of mutations in the FHC genes result from missense changes, although one of the most recent genes to be identified (cardiac myosin binding protein C gene, MYBPC3) has predominantly DNA mutations which produce truncated proteins. Both dominant negative and haploinsufficiency models have been proposed to explain the molecular changes in FHC. This study describes two Australian families with FHC caused by different mutations in MYBPC3. The first produces a de novo Asn755Lys change in a cardiac specific domain of MYBPC3. The second is a Gln969X nonsense mutation which results in a truncated protein. Neither mutation has previously been found in the MYBPC3 gene. The consequences of DNA changes on the function of cardiac myosin binding protein C are discussed in relation to current molecular models for this disorder.

Amino Acid Sequence↗
PubMed1998

The effect of different fibre components on growth rate, nutrient digestibility, rate of digesta passage and hindgut fermentation in domesticated rabbits.

Trials were conducted to study the effect of dietary fibre on performance and nutrient digestibility in growing rabbits. The basal diet was supplemented with 12% cellulose, pectin, lignin, or alfalfa, in four different treatments. Twenty-four 4-week-old California male rabbits were randomly allocated into four groups and placed in individual cages. The lignin supplement severely affected both feed intake and performance, pectin second, with dietary cellulose having the least effect. Dietary lignin significantly decreased the digestibility of crude protein, gross energy and dry matter content (P < 0.05). Rabbits on the pectin supplemented diet digested dry matter, crude fibre and neutral detergent fibre (NDF) better (P < 0.05) than other treatment groups. On the other hand, rabbits in the lignin group digested crude fibre, acid detergent fibre (ADF) and NDF significantly less well than rabbits in other groups (P < 0.05). Dietary lignin also significantly decreased the caecal concentration of volatile fatty acids (VFA, P < 0.05) but did not significantly affect the molar ratios of the VFAs among treatment groups. The turnover rate of the marker, chromic oxide, in the gastrointestinal (GI) tract of rabbits was 64.94, 51.81, 44.05 and 29.59 h in the pectin, alfalfa, lignin and cellulose treatment groups, respectively. The rate of turnover in the digestive tract significantly influenced digestibility of fibre components but did not significantly influence caecal fermentation.

Animal Feed↗
PubMed1998

Modulation of age-related alterations of iron, ferritin, and lipid peroxidation in rat brain synaptosomes.

Oxidative stress, as indicated by increases in lipid peroxidation, is generally found to increase with age. Also found in various tissues of aged organisms, including the brain, is the accumulation of iron, a pro-oxidant transition metal. In this study, iron content and ferritin levels were measured in the synaptosomes isolated from the frontal cortices of aged male Fischer 344 rats. Age-related changes in lipid peroxide and the peroxidizability of synaptosomal fatty acids were also studied in addition to the anti-aging effect of dietary restriction (DR) (60% food intake of ad libitum (AL) fed animals) on the modulation of age-related iron status and lipid peroxidation. When comparing the two dietary groups for the age-related production of reactive oxygen species (ROS), DR was shown to effectively suppress the amount of age-related ROS in the brain synaptosomes of these rats. Increases in lipid peroxide and accumulations of total iron and ferritin in brain synaptosomes of DR rats were also shown to be significantly lower than those of AL rats. Increased lipid peroxide and accumulated iron overload were effectively attenuated by DR, and the modulation of synaptosomal iron status was consistent with previous findings on the anti-aging action of DR.

Age Factors↗
PubMed1998

[A clinical analysis of 64 cases of pemphigus].

OBJECTIVE: Reasonable therapeutic dosage regimen for pemphigus are analyzed to find the factors related to prognosis. METHODS: A retrospective study is made on 64 cases of pemphigus who were admitted to our hospital between 1986-1996. RESULTS: Sixty-two of 64 cases with pemphigus were treated with systemic administration of corticosteroids. The average dosage of prednisone for controlling the diseases were 0.958 mg.kg-1.d-1 for mild-type of pemphigus (12 cases) and 1.145 mg.kg-1.d-1 for severe-type (50 cases) respectively. Furthermore, 26 of 62 cases were treated with corticosteroids only, and the average dosage of prednisone for controlling the diseases was 1.072 mg.kg-1.d-1 while in 36 cases treated with corticosteroids combined with immunosuppressors, the average dosage of prednisone was 1.178 mg.kg-1.d-1. The rate of side-effects and complications were 15.4% in patients with corticosteroids alone and 36.1% in patients with combined therapy. Six of eight patients who died were diagnosed pemphigus vulgaris and seven with a course of disease less than 3 years. CONCLUSIONS: We recommend a moderate to high dosage of corticosteroids be the first choice to control pemphigus. Those who were effective with steroids are not recommended to use additional immunosuppressors. Patients with pemphigus vulgaris usually have a poor prognosis while those who could survived more than 4 years usually have a better outcome.

Adolescent↗
PubMed1998

[Clinical study on effect of concentrated xuefu zhuyu pill on restenosis of 43 cases coronary heart disease after intracoronary stenting].

OBJECTIVE: To explore the clinical effectiveness of concentrated Xuefu Zhuyu Pill (CXZP) on restenosis (RS) of coronary heart disease (CHD) after intracoronary stenting. METHODS: Eighty-four successful intracoronary stenting patients were randomly divided into conventional treatment group (control group, 41 cases) and conventional treatment plus CXZP group (treated group, 43 cases). The follow-up underwent for 6 months. Clinical symptom, change of blood stasis were observed. And occurrence of restenosis was estimated by ECG exercise treadmill testing, emission computed tomography (ECT) and coronary angiography (CAG). RESULTS: The symptoms of blood stasis of treated group improved in the follow-up significantly (P < 0.01), and the integral of blood stasis were decreased significantly in the treated group vs the conventional treatment group (P < 0.01). The recurrent angina pectoris rate of the treated group was lower than the conventional treatment group (P < 0.01). The 61.9% of 84 patients reexamined the CAG in the follow up, and the lower restenosis rate (25.8%) in the treated group than in the conventional treatment group (32.1%, P = 0.59). CONCLUSION: There is the trend that CXZP could prevent restenosis. Therefore, it is necessary to increase the cases for further study of CXZP on preventing restenosis.

Adult↗
PubMed1998

[The role of glucocorticosteroid and theophylline in asthmatic inflammation of murine model and the inhibition in NO production in lung].

OBJECTIVE: To investigate the role of glucocorticosteroid and theophylline in treatment of asthmatic inflammation and their effects in production of nitric oxide (NO) and the expression of inducible nitric oxide synthase (iNOS). METHOD: A murine model was set up (A group: asthma model, N group: control mice), then the number of WBC, eosinophils% (EOS), total protein level and the NO level in brochoalveolar lavage fluid (BALF) were measured after treatment with glucocorticosteroid (C1 group: dexamethason inhalation; C2 group: dexamethason peritoneal injection and C3 group: budisonide inhalation) and aminophylline(T group). The expression of iNOS was studied by histochemistry and immunohistochemistry. RESULT: There was a significant increase in number of WBC [(10.64 +/- 0.75) x 10(7)/L vs (3.15 +/- 0.92) x 10(7)/L, P < 0.001), EOS% (12.55% +/- 7.64% vs 0.02% +/- 0.04%, P < 0.001), total protein level (0.124 +/- 0.080 g/L vs 0.008 +/- 0.004 g/L, P < 0.001) and concentration of NO (5.00 +/- 1.87 mumol/L vs 1.30 +/- 0.67 mumol/L, P < 0.001) in BALF after antigen challenge, and the expression of iNOS was increased in airway epithelial cells and alveolar macrophages. After administration of steroids and theophylline, the number of WBC[C1: (5.05 +/- 1.14) x 10(7)/L, C2: (5.47 +/- 0.59) x 10(7)/L, C3: (6.53 +/- 0.47) x 10(7)/L, T: (3.65% +/- 1.04) x 10(7)/L, P < 0.001], EOS% (C1: 0.10% +/- 0.06%, C2: 0.10% +/- 0.08%, C3: 0.24% +/- 0.33%, T: 2.84% +/- 1.90%, P < 0.001-0.005), total protein level (C1: 0.016 +/- 0.011 g/L, C2: 0.010 +/- 0.008 g/L, C3: 0.020 +/- 0.012 g/L, T: 0.012 +/- 0.008 g/L, P < 0.001-0.05) were significantly decreased. There was a significant reduction of NO level (C1: 1.20 +/- 0.97 mumol/L, P < 0.001) and iNOS expression after treated with steroids, but no significant change after management with theophylline. CONCLUSION: EOS is main inflammatory cell in asthma. NO may play an important role in aggravating asthma. Steroids and theophylline both can inhibit cell infiltration and serum protein leakage in asthma. Steroids can also inhibit the production of NO and iNOS expression. But theophylline has no significant effect in NO.

Animals↗
PubMed1998

[Regularities of carbon monoxide outgassing from two nonmetallic materials at different temperatures].

To investigate the regularity of carbon monoxide outgassing from nonmetallic materials in air tight cabin, two nonmetallic materials was observed. 30-9304 foam plastics and aluminum-plated polyester adhesive film were sealed in airtight glass ampules, and outgassed for 70 days at four different temperatures. The outgassing CO was determined continuously with transform/gas chromatography. Curve fitting and regression were used in data analysis. The results showed that: (1) when temperature was kept constant, the relation between the outgassed CO and outgassing time appeared to be a "s" shaped or exponented curve; (2) at a fixed time the amount of outgassed CO increased with temperature exponentially; (3) the amount of CO outgassed in 12 h at 100 degrees C from the two materials corresponds those for 45 d at 50 degrees C, there is an iso-effect principle for CO outgassing.

Air Pollutants↗
PubMed1998

[Analysis and toxicological evaluation of hazardous gases in sealed cabin].

82 volatile organic compounds (VOCs) of eight organic sorts and 3 target inorganic compounds in a sealed cabin that simulating the flying spaceship were identified and quantified for 5 d, the law of hazardous gas concentration variation was discussed, and the atmosphere toxicology was evaluated preliminarily. It provides a basis for detecting gas compounds and evaluating the atmosphere toxicology in the spaceship.

Air Pollutants↗
PubMed1998

[The effects of Chinese medicine herb mixture on cell-mediated immune functions and four kinds of acute-phase reaction proteins in burn patients].

OBJECTIVE: To search for immunomodulators to improve postburn immune function disorder. METHOD: We studied the Chinese medicinal herbs. On the basis of previous data, we prepared a kind of Chinese medicinal herbal mixture and studied its effects in vivo and in vitro. RESULT: The mixture could restore the cell-mediated immune response such as the production of interleukin 2 and the T cell proliferative ability, and could also adjust the levels of serum acute-phase reaction proteins, i.e, haptoglobin, prealbumin, transferrin and alpha 1-acid glycoprotein. CONCLUSION: The Chinese herbal mixture showed immune regulatory effects on body defence imbalance and also on acute phase reaction proteins in burn patients.

Acute-Phase Proteins↗
PubMed1998

[Investigation on resources and commodities of Chinese medicinal herbs of Jili].

OBJECTIVE: To make clear the current situation of application of the Chinese medicinal herbs of Jili. METHOD: The medicinal resources and commodities of the berbs in some provinces and cities in China were investigated. RESULT: The species Tribulus terrestris included in is widely distributed in China. The fruit of T. terrestris which is widely used in China as a traditional medicine is commonly called Yingjili. Being only the fruit of Atriplex entralasiatica Ruanjili is produced mainly in Shandong Province and customarily used as Fructus Tribuli in some areas of Shandong and Hebei Provinces. CONCLUSION: The current situation of medicinal application of Jili basically conforms to the requirements of . The main variety is Yingjili.

China↗
PubMed1998

Corticotropin-releasing factor increases dihydropyridine- and neurotoxin-resistant calcium currents in neurons of the central amygdala.

Corticotropin-releasing factor (CRF) is an important mediator of stress responses in the brain, and CRF receptors and CRF-containing neurons and terminals are located within the central nucleus of the amygdala (CeA). CeA neurons possess multiple types of Ca++ channels, including L, N and Q types and a current resistant to saturating concentrations of dihydropyridine and neurotoxin antagonists. In this study, we used whole-cell patch-clamp techniques to study the effects of CRF on whole-cell Ca++ current (ICa) in acutely dissociated CeA neurons and determine components of the current affected. CRF (1-400 nM) increased the peak of the ICa in approximately 50% of the CeA neurons recorded. In the remaining neurons, CRF had little effect. The CRF-induced increase in the ICa was concentration dependent and the estimated EC50 value was 14.9 nM. CRF (50 nM) increased the peak ICa by 25 +/- 5% (n = 9). CRF produced an increase in both the transient and the steady state current but did not shift the peak of the current-voltage relationship. CRF did not affect the voltage dependence of activation and inactivation, and the CRF effect on ICas was not significantly different when the neuron was held at -80 or -40 mV. The competitive CRF receptor antagonist (alpha-helical CRF9-41, 3 microM) blocked the CRF-induced increase in ICa, suggesting that the effect of CRF is receptor mediated. CRF (50 nM) enhanced the ICa (20 +/- 3%) in the presence of saturating concentrations of the L-type blocker nimodipine and neurotoxin N- and Q-type blockers omega-conotoxin GVIA and omega-conotoxin MVIIC. We conclude that CRF increased, through a receptor mechanism, dihydropyridine- and neurotoxin-resistant current(s) in CeA neurons.

Amygdala↗
PubMed1998

Prenatal diagnosis for thalassaemia in a multicultural society.

The provision of a prenatal diagnosis service for thalassaemia is becoming more demanding. In an ethnically-diverse community, the number of mutations has increased. Requests for prenatal testing continue to come at advanced stage in pregnancy, often without the underlying mutation having been identified. Although controls are included in PCR assays, errors can still occur. The alternative to DNA testing, i.e., an alpha/beta globin chain synthesis ratio on a fetal blood sample, is now less readily available. In the circumstances described, the laboratory must adopt a more efficient and reliable approach to DNA mutation analysis. With currently available technology, this improvement is more likely to come through increased automation. To achieve this aim, we have moved to capillary electrophoresis. With capillary electrophoresis we are able to use a PCR-based screening strategy which can detect up to 11 beta thalassaemia mutations. The actual prenatal test is undertaken using two independent PCRs thereby reducing the potential for error. Despite the advantages of PCR, approximately 12 per cent of beta thalassaemia and about nine per cent of alpha thalassaemia cases require further study in our experience. In this situation, capillary electrophoresis has again proven helpful since a DNA scanning approach, such as single strand conformation polymorphism, can be automated to identify the region of DNA to be sequenced.

Asia, Southeastern↗