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Biomedical subjects

Q Yu

Publications and source records attributed to Q Yu.

At least 253 records · Page 14Linked to original sources
PubMed1994

[An epidemiologic survey of blindness and low vision in persons over 45 years old in Doumen County].

An epidemiologic survey of blindness and low vision in persons over 45 years old in Doumen County, Guangdong Province was carried out in 1991. The sample size was 932 subjects. We found that the impairment of vision < 0.3 accounted for 10.94%. The prevalences of bilateral blindness and low vision were 1.61% and 3.22%, respectively. Both the prevalences of blindness and low vision were increased with age. The leading cause of blindness was cataract (45.20%) and the second, corneal opacity (16.70%).

Aged↗
PubMed1994

[An epidemiologic survey on lens opacities in Doumen County].

Age-related lens opacity is the main cause of vision disability in elderly all over the world. A longitudinal study was designed to investigate the prevalence of lens opacity. 1,817 eyes of 932 adults over 45 year-old were sampled randomly. The lens opacities were graded according to a standardized photo of the Lens Opacities Classification System II (LOCS-II). The prevalence of lens opacities in nuclear color, nuclear opacity, cortical opacity and subcapsular opacity was 16.1%, 28.6%, 30.3% and 8.7% respectively. The frequency of all four types of opacities increased with age. The prevalence of lens opacities in four types were higher in female than that in male. The color of nuclear was related to the degree of myopia, the deeper the higher. These results are important information in eye care project.

Age Factors↗
PubMed1994

[The diagnostic value of computed coronal tomography in maxillofacial tumors].

CT images in both transverse axial and coronal planes of 52 cases of maxillofacial tumors were analyzed. The authors emphasized that coronal technique should not be neglected, especially when the tumor was near the base of the skull, the sphenoid sinus and the hard palate. Transverse axial scan alone could not demonstrate the exact extent of invasion and the adjacent relationship. Coronal scan affords exceptional visualization. In such conditions, the combination of scans in two planes is the most helpful in delineating such lesions. It provides important information for determining surgical or radiotherapeutic approaches.

Adolescent↗
PubMed1994

[Taxonomy of 1043 strain producing actinospectacin].

Streptomyces strain 1043 was isolated from a soil sample collected in Hangzhou. The strain may produce two antibiotics--Actinospectacin and Streptovaricin. Its aerial mycelia are apricot orange to carnelian red on most media. An outstanding characteristic of 1043 strain is the development of pigment granules in both vegetative and aerial mycelia. Its culture and physiological characteristicus were found to resemble those of Streptomyces spectabilis. Streptomyces strain 1043 was named Streptomyces spectabilis 1043.

China↗
PubMed1993

Neutral axis location in bending and Young's modulus of different layers of arterial wall.

With few exceptions, experimental results on the blood vessel elasticity have been analyzed with the blood vessel wall treated as a homogeneous material, probably because the experiments have been limited to inflation and stretching. To advance the subject, we must evaluate the force-deformation relationship of different layers of the vessel. A key strategy to do this is to study nonaxisymmetric deformation of the vessel wall so that the different layers of the vessel may deform in different amounts at different places. One of the most effective nonaxisymmetric deformations that can be imposed on the vessel wall is bending. The first important question to ask about bending is, Where is the neutral axis? In this study, a method to determine the neutral axis is presented. We found that the neutral axis of the aorta of the pig lies in the medial layer about one-third of the wall thickness from the endothelium. We measured the strain distribution in the vessel wall by optical methods. Using the load-deflection relationship, we evaluated the Young's modulus of the intima-media layer and that of the adventitia. They differ by an order of magnitude. Our results show that the Young's modulus of the intima-media layer of the pig thoracic aorta is 43.2 +/- 15.8 kPa, whereas the Young's modulus of the adventitial layer is 4.70 +/- 1.72 kPa, in a linear range of the stress-strain relationship including the zero-stress state and the no-load state.

Animals↗
PubMed1993

Cloning into M13.

Explore the source record for details and available documents.

Bacteriophage M13↗
PubMed1993

[Radiologic similarity and dissimilarity of Histiocytosis X in the mandible between non adult and adult]

28 cases of Histiocytosis X in the mandible were divided into two groups:the non adult group (19 cases,21 foci).and the adult group(9 cases,12 foci).their similarity and dissimilarity in radiological appearances were contrasted individually.The authors consider there were different roentgenographic manifestations between the two groups according to the diversity of physilological and morphological configuration in the mandible.The former group which had its characteristic roentgenologic feature displayed a radiolucent region with an irregular margin mostly accompanied with a periosteal reaction at the inferior and lateral surfaces of the mandible.Owing to lacking above mentioned demonstration,it was difficult to distinguish the lesions of later group from other disease in the mandible.

Journal Article↗
PubMed1993

[Initial investigation of the value of CT in pulmonary metastases originating from head and neck malignant tumors]

CT image and its diagnostic value were analyzed and compared with plain chest film on 12 cases of pulmonary metastases originating from malignant tumors of head and neck,all cases were pathologically verified.CT scan performed on each cases who had definite or suspicious lesion on plain chest film.The result presents that CT can:(1)confirm the suspiciousness of metastatic lesion.(2)confirm the number of metastatic lesion.(3)early detection on pulmonary metastasis. 4.identification on occult pulmonary metastasis. 5.Find out costal bone and pleural metastasing accuracy of pulmonary metastasis,but also provide information for clinical selecting treatment.

Journal Article↗
PubMed1993

[Observation of clinical effect of bioactive glass titanium alloy core implant]

A novel kind of implant made of titanium alloy spray coated with a suitable bioactive glass was investigated.49 implantation were done in clinical patients from Oct 1988 to 1992.42 implantation functioned well up to the time.7 implantation failed. The success rate is 85.71%.The authors have also discussed the indications,method of implantation and other related things on the paper.

Journal Article↗
PubMed1993

[The correlation between postsynaptic inhibition and GABA, opioid peptides, SP in electroacupuncture].

Identified tract cells in lumbar enlargement were recorded from intact anaesthetized rats. The prolongation of the latency of antidromic action potential was a measure of postsynaptic inhibition. Both ST 36 and SP 6 were stimulated electrically. In EA group (N = 12) EA prolonged the latency for 0.111 +/- 0.022 ms (P < 0.001). In bicuculline group (N = 12) the prolongation of the latency for 0.010 +/- 0.004 ms (P < 0.05) by EA was less than that of EA group with statistical significance. In naloxone group (N = 12) and SP antiserum group (N = 12) EA did not induce a significant prolongation of the latency. It suggested that GABA, opioides and SP might be involved in postsynaptic inhibition induced by EA.

Acupuncture Analgesia↗
PubMed1993

Protective effect of Salmonella typhimurium Re-LPS antiserum.

There is increasing evidence that antiserum to LPS can reduce the morbidity and mortality of Gram-negative bacterial infections. We report that antiserum to S. typhimurium SL 1102 (Re mutant strain) has excellent cross-protective activity. Antisera to these bacteria and to their Re-LPS were prepared in rabbits immunized with heat-killed bacterial cells and with Re-LPS preparations. Re-LPS antibody titers were tested by immune hemagglutination (IHA) and by ELISA. These antisera were found to be capable of protecting ICR mice against lethal challenge with S-type S. typhimurium 50014 (100 LD50), E. coli 0111:B4 (32 LD50), Pseudomonas aeruginosa (8 LD50) and Klebsiella pneumonia (16 LD50). We used gastric mucin (5%) as a virulence enhancing agent for the bacterial challenges. The IHA titer of antibody to the homologous strain proved to be much higher than that of other strains. Protection by the sera was 75-100%, 25% and 0% when injected 24, 48 or 72 h before the challenge, respectively. The survival rate was more than 50% when the antiserum was injected 5-7 h after challenge with a ten-fold or higher lethal dose. No protection was observed against such high challenge when the serum was injected later. According to these results, Re-LPS antiserum provides better protection than S-type specific antisera.

Animals↗
PubMed1993

[The relationship between vaccinia virus DNA replication and intermediate filaments].

Various DNA components which were extracted with gentle cell fractionation from the HeLa cells after 4 h vaccinia virus infection were detected by dot hybridization technique. The virus DNA mainly exist in intermediate filament-lamina-nuclear matrix complex. With DGD embedment free technique and electron microscopic autoradiography, the newly synthesized virus DNA is found to be associated with intermediate filaments. The results of southwestern hybridization demonstrate that vaccinia virus DNA has specific affinity to intermediate filaments and some nuclear matrix proteins.

Blotting, Southern↗
PubMed1992

The role of hyaluronan-binding protein in assembly of pericellular matrices.

Hyaluronan-dependent pericellular matrices or "coats" are expressed by a variety of cell types in culture and modulation of their expression may be important in regulation of cell interactions in vivo during development. Monoclonal antibody IVd4, which recognizes hyaluronan-binding protein with the properties of a hyaluronan receptor, was shown to block formation of these coats by a variety of cells. Using rat fibrosarcoma cells, it was found that the antibody not only blocked initial formation of the coats but also caused their loss when added subsequent to formation. The loss of preformed coats in the presence of antibody occurred at 4 degrees and 37 degrees, implying that the function of hyaluronan-binding protein in coat formation is not in mediating metabolic processes. The antibody also had no significant effect on hyaluronan production by the fibrosarcoma cells. In addition, hyaluronan hexasaccharide, a competitive inhibitor of the interaction between polymeric hyaluronan and its cell surface receptor, was found to inhibit coat formation. Thus it is concluded that a hyaluronan-binding protein with the properties of a hyaluronan receptor is required for pericellular matrix formation.

Animals↗
PubMed1992

Molecular analysis of neurofibromatosis type 1 mutations.

We have examined a panel of 115 unrelated NF1 individuals for mutation in the 3' region of the NF1 gene, using Southern blotting and polymerase chain reaction amplification of exons followed by single-strand conformation polymorphism (SSCP) analysis. We found only 2 unequivocal mutations: a 571 bp deletion which removed exon 6 and resulted in a frameshift in exon 7, and a 2 bp deletion in exon 1. A third sequence variation detected by SSCP was predicted to cause a lysine-arginine substitution in exon 6. This is a conservative change, and since the affected individual is a new mutation whose parents are not available, we cannot be sure of its biological significance. We detected mutations in at most 3% of individuals, from an analysis which covered 17% of the coding sequence by SSCP and a larger region by Southern blotting. This relative failure to detect mutations accords with the experience of others. Even allowing for the incomplete sensitivity of the methods used, the results suggest that the majority of NF1 mutations lie elsewhere in the coding sequence or outside it.

Base Sequence↗