Search PubMed⌕ Search

Biomedical subjects

Q Yu

Publications and source records attributed to Q Yu.

At least 235 records · Page 13Linked to original sources
PubMed1995

Epidemiological survey of primary angle-closure glaucoma in Doumen.

PURPOSE: To determine the prevalence of primary angle-closure glaucoma (PACG) in Doumen Countty, Guangdong province. METHODS: Four villages from eight districts in doumen were selected by stratified, cluster and random sampling. Of a total of 1055 people aged 45 years or over, 932 (88.62%) were examined. The examination and diagnostic criterion were similar to those of shunyi survey. RESULTS: The prevalence of PACG in subjects over 45 year of eye is 0.64%, in those over 50 years of age is 0.85% in Doumen, which is significantly lower than the corresponding figure of 1.99% in shunyi (P < 0.05). CONCLUSION: This study identifies the prevalence of PACG in Doumen is lower than in Shunyi.

Aged↗
PubMed1995

[Simultaneous staining with fluorescein diacetate-propidium iodide to determine isolated cochlear outer hair cell viability of guinea pig].

A simultaneous double-staining procedure using fluorescein diacetate (FDA) and propidium iodide (PI) is discribed for use in the determination of isolated cochlear outer hair cell viability. With exciter light, viable cells fluoresce bright green, while nonviable cells are bright red. In cell culture and cytotoxicity studies, double-staining with FDA-PI is a accurate method to discriminate between live and nonviable cells.

Animals↗
PubMed1995

[Effect of electrical stimulation of red nucleus on acupuncture analgesia].

The function of red nucleus (RN) was important in motor control. This work was to study whether the RN influenced the effect of EA and the somatosensory afferent system. C-responses of spinal dorsal horn neurons (SDHN) were recorded as nociceptive responses. Electrical stimulation of RN could intensify the inhibitory effect of EA and inhibit nociptive response of SDHN. Naloxone (NX) could completely block that inhibition of RN. The result inferred that the RN can modulate both of somatomotion and somatosense. The endogenous opiate system is involved in the somatosensory modulation of RN.

Acupuncture Analgesia↗
PubMed1995

[The study of grading standard photos of oblique flashlight test].

PURPOSE: We try to establish a convenient, fast, inexpensive and accurate screening test and to make a grading standard. METHODS: 1. In 120 eyes, we measured axial anterior chamber depth (AACD), peripheral anterior chamber depth (PACD), antrior chamber angle (ACA) and took iris pictures under slitlamp microscope imitating the oblique flashlight test. The clear photos from 107 eyes were measured by computerized image analysis to determin the ratio of the width of nasal iris and nasal iris light band (ILBR). Then the linear correlation of ILBR with AACD, PACD and ACA was analyzed statistically. The ILBR was graded according to the analytic results. RESULTS: 1. Relationship of ILBR with PACD, AACD and ACA: the linear correlation analysis showed a positive correlation relationship among ILBR, PACD and AACD (r = 0.9451, P = 0.0001 and r = 0.8725, P = 0.0001), and showed a negative correlation relationship between ILBR and ACA (r = -0.7582, P = 0.0001). 2. ILBR grading standards: grade 1. ILBR < or = 1/5, the gonioscopy usually demonstrates a dangerously narrowed angle (N3-4); grade 2, ILBR > 1/5- < or = 1/4, the gonioscopy will always show a capable of closure angle (N2-3); grade 3, ILBR > 1/4- < or = 1/3, that angle is incapable of closure (N1-2); grade 4, ILBR > 1/3- < or = 1/2, the most angles show wide (W-N1); grade 5, ILBR > 1/2, the gonioscopy shows all wide angle. The linear correlation analysis also showed correlation relationship among ILBR grades PACD, AACD and ACA. CONCLUSION: Through arational ILBR grades and a set of grading standard photos, it is found that the test is not only convenient, fast, and inexpensive, but also accurate as well. The test not only plays an important role in PACG screening, but also may be applied widely to estimate shallow AACD and narrow angle in the clinic.

Anterior Chamber↗
PubMed1995

[A role of oblique flashlight test in screening for primary angle closure glaucoma].

PURPOSE: To study the effect of oblique flashlight test in screening for primary angle closure glaucoma. METHOD: Two hundred adults over 50 years old were sampled randomly at Doumen county of Guangdong province in 1995. 390 eyes were measured by oblique flashlight test according to grading standard photos of oblique flashlight test. Other ocular examinations consisted of intraocular-pressure measurement with Schiotz tonometer, gonioscopy, and optic disc appearance. RESULTS: The result showed 25.2% of the examined eyes had the oblique flashlight grade < or = 2, and tended to be increasing with age (x2 = 8.597, P < 0.05) and in females (x2 = 14.89, P < 0.01). Based on temporal anterior chamber angle < or = 2 (Shaffer's grade), the obligue flashlight grade < or = 2 found that occludable angle sensitivity was 91.7%, specificity was 91.5%, and 8.16% of the eyes had primary closure angle glaucoma. No patient was found in oblique flashlight grades > or = 3. CONCLUSION: This study shows that oblique flashlight test conforms to screening test needs, and plays an important role in screening for primary closure angle glaucoma. We suggest that oblique flashlight grades < or = 2 as cutoff point of screening for occludable angle.

Aged↗
PubMed1994

Evidence from CD spectra that d(purine).r(pyrimidine) and r(purine).d(pyrimidine) hybrids are in different structural classes.

CD spectra and difference CD spectra of four d(oligopurine).r(oligopyrimidine) and four r(oligopurine).d(oligopyrimidine) hybrid duplexes containing mixed A.T(U) and G.C base pairs were compared with the spectra of four DNA.DNA and four RNA.RNA oligomer duplexes of similar repeating sequences. The 16 duplexes were formed by mixing oligomers that were 24 nucleotides long. The buffer was 0.05 M Na+ (phosphate), pH 7.0. DNA.DNA and RNA.RNA oligomer duplexes were used as reference B-form and A-form structures. We found that the CD spectra of d(purine).r(pyrimidine) and r(purine).d(pyrimidine) hybrid duplexes were different from the CD spectra of either DNA.DNA or RNA.RNA duplexes. The data suggested that these hybrids have intermediate structures between A-form RNA and B-form DNA structures. The CD spectra of d(purine).r(pyrimidine) and r(purine).d(pyrimidine) hybrid duplexes were different from each other, but the hybrids in each class had consistent CD spectra as indicated by nearest-neighbor comparisons. Thus, it appeared that the two types of hybrids belonged to different structural classes. The negative 210 nm band found in difference CD spectra was correlated with the presence of an r(purine) strand in the hybrid duplexes. The melting temperatures (Tm values) of these hybrids were compared with the Tm values of the DNA.DNA and RNA.RNA duplexes. The order of the thermal stability was: RNA.RNA duplex > r(purine).d(pyrimidine) hybrid > DNA.DNA duplex > d(purine).r(pyrimidine) hybrid, when comparing analogous sequences.

Base Composition↗
PubMed1994

On-line buffer removal and fraction selection in gradient capillary high-performance liquid chromatography prior to electrospray mass spectrometry of peptides and proteins.

The technique for on-line removal of buffers and for fraction selection to eliminate source clogging and suppression of electrospray ionization by unwanted constituents consisted of: (i) selecting the initial mobile phase composition to retain analytes on top of a capillary high-performance liquid chromatography (HPLC) column; (ii) washing the buffer isocratically to waste, using a two-way micro dump valve; (iii) starting the gradient and switching the dump valve to introduce analytes into the source. Peptide and protein mixtures were prepared in 0.05-0.5 M phosphate and 0.55 mM tris-based buffers, and water. After buffer removal, chromatograms and electrospray spectra were indistinguishable from those of aqueous controls, down to 1 pmol (acidic fibroblast growth factor) consumed, and up to 78 kDa (bovine transferrin) molecular weight. Aided by the dump valve, 100 fmol of angiotensin could be fractionated and identified on the slope of a 10 x 10(6) fmol of leucine enkephalin HPLC peak. On-line buffer removal and fraction selection eliminate the need for additional preparation steps than can lead to excessive sample losses.

Buffers↗
PubMed1994

Characterization of two density populations of feline calicivirus particles.

Feline calicivirus (FCV) F9 strain was propagated in Crandall-Reese feline kidney cells. Two density populations of viral particles were observed after equilibrium centrifugation in an isopyknic CsCl gradient. The buoyant density of the heavy particle (PH) is 1.33 g/ml. The light particle (PL), a previously undescribed form of feline calicivirus, has a buoyant density of 1.22 g/ml. The PH and PL presented a similar morphology by electron microscopy. Western blot showed that both PH and PL contained a major polypeptide of the typical FCV capsid protein with a molecular weight of 62,000. Infectivity assay and RNA isolation demonstrated that PH is the intact infectious virion while PL is FCV empty capsid.

Animals↗
PubMed1994

Circadian variation in fibrinolytic activity in patients with variant angina.

BACKGROUND: Coronary artery spasm induces activation of the coagulation system. Turnover and maintenance of thrombus depend not only on formation but also on lysis. The relation between coronary spasm and fibrinolytic system has not been elucidated. OBJECTIVE: To examine whether there is impairment of or a circadian variation in fibrinolytic activity in patients with variant angina. METHODS: Plasminogen activator inhibitor (PAI) activity and concentrations of tissue plasminogen activator (t-PA) antigen were measured in venous plasma samples taken at 2200, 0600, and 1400 and 24 h Holter tapes were recorded in 15 patients with variant angina, 12 patients with stable exertional angina, and 12 controls. RESULTS: There were significant circadian variations in PAI activity and t-PA antigen with peak values at 0600 in all three groups. Mean (SEM) PAI activity (IU/ml) at 2200, 0600, and 1400 was 6.1 (1.1), 11.0 (1.3), and 4.4 (0.6) in the variant angina group; 1.8 (0.7), 5.6 (1.1), and 1.2 (0.3) in the stable exertional angina group; and 1.1 (0.5), 4.5 (0.8), and 0.7 (0.3) in the control group. Furthermore, both plasma PAI activity and t-PA antigen concentrations were significantly higher in the variant angina group than in the stable exertional angina group and the control group at each sampling time. CONCLUSIONS: In patients with variant angina there was a circadian variation in fibrinolytic activity, which was lowest in the early morning, and impaired fibrinolytic activity particularly in the early morning, when attacks of angina occur most frequently.

Aged↗
PubMed1994

[Cytokine production by MTSC 4 cells, an established mouse thymic dendritic cell line].

The cytokine production by MTSC 4 cells, a murine thymic dendritic cell line established in our laboratory, has been investigated. Without exogenous stimulation, the MTSC 4 cells constitutively produce multiple types of cytokines, including IL-1, IL-6, IL-7, CSF, IFN and Chemotactic factor (CF). Of which, IL-6 and IFN were abundant: IL-1 and Chemokine, moderate: IL-7 and CSF at low level. MTSC4 cells could not produce detectable either IL-3 of TNF alpha. The establishment of MTSC 4 may be useful in the analysis of the mechanism of thymus selection, and in the study of the network regulation of autocrined cytokines.

Animals↗
PubMed1994

Airway provocation test with ragweed pollen extract in Chinese asthmatics.

As ragweed becomes widespread over China, ragweed pollenosis tends to be more frequent. Incidence of ragweed pollenosis is about 1.04% in Qingdao district. To elucidate ragweed as an allergen in the development of bronchial asthma, ragweed pollen extract inhalation airway provocation tests (APT) were studied in 55 patients with ragweed pollenosis. A single dosage of 9,000 PNU ragweed pollen extract was applied and positive response was defined as more than 35% fall in SGrs at the dose of PT35-Grs. Among 55 patients, positive APTs were found in 27 cases (49%), dual late-phase responses in 11 patients, single late-phase responses in 2 patients in the complicated asthma group. Late-phase responses were related to the increased specific IgE and strong positive skin test response (wheal > 11 mm). The results suggested ragweed pollen was one of the important allergens causing bronchial asthma. There was airway hyperresponsiveness to ragweed pollen in some patients (20%) with ragweed pollenosis without asthmatic symptoms.

Adolescent↗
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↗