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Biomedical subjects

Q Yu

Publications and source records attributed to Q Yu.

At least 181 records · Page 10Linked to original sources
PubMed1998

Immunohistochemical study of Fas antigen expression in synovial tissues from patients with rheumatoid arthritis.

OBJECTIVE: To investigate the location and expression of Fas (Apo-1, CD-95) antigen in synovial tissue from rheumatoid arthritis (RA). METHODS: Immunohistochemical technique was used to identify the location and expression of Fas antigen in synovial tissues from 27 RA, 11 osteoarthritis (OA), 7 ankloysing spondylitis (AS), 3 pigmented villo-hyperplastic synovitis, 1 juvenile rheumatoid (JRA) patients and 5 "normal" control subjects. RESULTS: Fas was strongly expressed by synoviocytes and infiltrated lymphocytes in approximately two-thirds of RA patients (16/27). However, only weak expression occurred on lymphocytes in 3 of 11 OA, 1 of 7 AS patients and 1 of 5 "normal" subjects. The stain-positive substance in the forms of rings, granules, or dust was deposited on the cell membrane and in cytoplasm. CONCLUSION: The expression of Fas may be involved in the mechanism of synovium proliferation and abnormal activation of local lymphocytes in RA.

Adult↗
PubMed1998

[Effect of ischemia/reperfusion in cardiac surgery with cardiopulmonary bypass on nitric oxide levels of peripheral blood in patients].

To examine the effect of ischemia/reperfusion in cardiac surgery with cardiopulmonary bypass (CPB) on nitric oxide (NO) levels of peripheral blood, venous levels of NO2- and NO3- were measured at multiple time-points before, during, and after CPB by means of high-pressure liquid chromatograph to reflect NO concentration indirectly in 20 patients. The results showed there was a linear regression between the decreased trend of NO release at the period of peri-CPB is related to the endothelial cell activation caused by ischemia/reperfusion at the same time. Therefore it is necessary to explore the regulation and action of NO release during systemic inflammatory response procedure in CPB.

Adult↗
PubMed1998

[A computerized information system for gynecological patients].

OBJECTIVE: Clinical experiences in the fields of general gynecology, gynecological oncology and reproductive endocrinology had been accumulated over a long period of time. All of the recorded information was written on various kinds of sheets that could easily be damaged and lost with frequent reading. Statistical works were done manually. This is the situation may encountered by all of the hospitals in China, so a computerized information system for gynecological patients is eagerly needed. METHODS: The program was designed on the basis of Foxpro 2.6 for Windows. RESULTS: The interfaces were specially designed for every of 72 databases to be like the style of patient's records which can be easily operated with mouse pressing buttons. Some of the databases such as basal body temperature, metastasis of lymph nodes and classification of endometriosis were carefully designed. Because the program will be used in China, the interfaces were all in Chinese. A dictionary was used to simplify the importing of the data. When import, one can easily press the line with the appropriate meaning in the dictionary. A strong statistical function was attached to the program. With its friendly interface, statistical work can be done with ease. This system is capable of further development and fit into needs of various hospitals and departments. CONCLUSION: This program is very useful for clinical doctors as well as scientific research personnel. With the help of this program, efficacy of our medical work can be raised, clinical experiences can be summarized in time and the clinical level can thus be improved.

Female↗
PubMed1998

[Diagnostic value of p53 protein examination in lung cancer through preoperative fibro-optic bronchoscope brushing and biospy].

OBJECTIVE: To study the expression of p53 protein in lung cancer and benign pulmonary diseases through preoperative fibro-optic bronchoscope brushing and biospy as an approach to early diagnosis of lung cancer and to explore correlation between the expression of the gene product and metastatic involvement of hilar or mediastial lymph nodes. METHODS: Using a monoclonal antibody against p53, the expression of p53 protein was determined by immunocyto-histochemical techniques. RESULTS: Positive staining of p53 protein of cells obtained form bronchoscopic brushing and biospy was 33.3% (12/36) and 47.2% (17/36) respectively in lung cancer patients. There was 61.1% (22/36) positive staining of cells harvested by brushing plus biospy in lung cancer. No correlation between p53 protein expression and cell differentiation, histologic type or pTNM staging. No p53 expression was observed in benign pulmonary diseases. CONCLUSION: p53 protein expression in cells collected from bronchoscopic brushing and biopsy may be useful in the diagnosis of lung cancer.

Adenocarcinoma↗
PubMed1998

[Proximal bronchial invasion of lung cancer: a clinicopathological study].

OBJECTIVE: To investigate the characteristics of proximal bronchial invasion of lung cancer of different types. METHODS: Proximal bronchus of 151 operatively resected specimens of hilar type lung cancer was selected for cross-sectional pathological study. Forty one specimens were obtained from total pulmonectomy, and 110 from pulmonary lobectomy. RESULTS: Evidence showed that the direct invasion of tumour cells through the submucosal layer or multiple layers was the major form of lung cancer spread; 96.6% of the cancerous invasion occurred at the proximal bronchial wall less than 1.5 cm apart from the margin of the cancer. The extension of invasion was correlated with the histopathologic type of cancer, mode of invasion and TNM classification(pT, pN). Besides, the invasion in the bronchial wall by metastatic lymph nodes was also an important way for the cancer spread. CONCLUSION: In order to achieve radical removal of tumor, it is imperative to keep a distance of 1.5 cm or more between the excision margin of the bronchus and the tumor, and to completely resect the hilar and mediastinal lymph nodes.

Adenocarcinoma↗
PubMed1998

[Effects of heat, noise, and their combination on plasma atrial natriuretic peptides, cardiodilatin, endogenous digitalis like substance, angiotensin II and endothelin in rats].

Plasma contents of atrial natriuretic peptides (ANP), cardiodilatin (CDD), endogenous digitalis like substance (EDLS), angiotensin II (A II) and endothelin (ET) were determined in rats following exposure to high temperature, noise and a combination of the two. It was found that plasma content of ANP after heat exposure decreased significantly, CDD and A II content after heat or noise exposure increased obviously, ET content decreased significantly after exposure to combined factors. ANP and CDD have the same physiological function and changes. ANP, CDD and A II observed in the present study were considered to be compensatory responses. It is harmful if exposure to high temperature or noise lasts for a long time.

Angiotensin II↗
PubMed1998

[The effect of local growth in long bones following two different epiphyseal-stimulating procedures: an experimental study].

OBJECTIVE: To study the effect of local growth in long bones of the rabbits following two different epiphyseal-stimulating procedures. METHODS: These were osteotomy in the metaphysis near the proximal tibial epiphyseal plate and hemicirecumferential periosteal excision on the proximal tibial epiphysis. Tibia roentgenography, tetracycline labelling, histological method and electron microscopy were used. RESULTS: The local stimulating effect following hemi-circumferential periosteal excision was more evident than following osteotomy. CONCLUSION: The procedure of periosteal excision could be good for the treatment of children knee' deformity.

Animals↗
PubMed1998

[Initial evaluation of mass lesions in the head and neck with enhanced (Gd-DTPA) MR imaging].

OBJECTIVE: To evaluate mass lesions of the head and neck with enhanced (Gd-DTPA) MR imaging. METHODS: Twenty-five of patients (13 males and 12 females; mean: 46.9 years) suffered from mass lesions of the head and neck inspected with Gd-DTPA MR imaging, 17 cases were certificated histopathologically and followed up. The examinations of all patients were carried out with plain T1-weighted spin-echo sequences (TR/TE = 500-600/30), and Gd-DTPA enhanced T1-weighted spin-echo sequences (TR/TE = 300-500/30). RESULTS: Comparing with plain MR imaging, 23 mass lesions were stained on SE T1-weighted images (23/25) after intravenous administration of Gd-DTPA. The enhanced patterns of these lesions might be divided into homogeneous (10/23) and inhomogeneous (13/23). Gd-DTPA was helpful in delineating extent of 16 mass lesions. CONCLUSION: The various morphologic manifestations of enhanced lesions have close relations with their own intimate structures. The enhanced MR imaging is superior to plain MR imaging on displaying the inner structure and extent of diseases and estimating the recurrent lesions.

Adolescent↗
PubMed1998

[Six year follow-up of suspects of primary angle-closure glaucoma].

OBJECTIVE: To understand the natural history and the risk factors of primary angleclosure glaucoma and obtain experiences that might help screening for the disease. METHODS: Four hundred and eighty-five suspects were screened from 6 548 population aged over 40 years. The suspects were then followed up within six years. The following examinations were performed: visual acuity, axial anterior chamber depth, peripheral anterior chamber depth, intraocular pressure and cup/disc ratio of optic nerve papilla. The suspects with high risk were further examined. RESULTS: During the follow-up period, twenty patients (4.1%) in the suspects developed angle-closure glaucoma, 14 cases had natural attack (Acute onset developed in 6 cases and 8 cases were in chronic stage) and 6 cases were found at early stage. The anterior chamber depth shallowed progressively in 28% of suspects. CONCLUSION: Anterior chamber depth is an important index for screening of primary angle-closure glaucoma, and the regular follow-up is of significance for the suspects.

Anterior Chamber↗
PubMed1998

[The survey of anterior chamber angle in a population of middle and old age].

OBJECTIVE: To determine the condition of anterior chamber angle in a population of middle and old age, and afford data for screening of angle closure glaucoma. METHODS: Two hundred people aged 50 years or older were selected by random sampling in four districts of Doumen county. The anterior chamber angle of all people was evaluated by Goldmann one-mirror gonioscope, and the angle was graded according to the Spaeth and Shaffer's grading system. RESULTS: Three hundred ninety eyes were examined, 12% (inferior angle) to 30% (superior angle) were Shaffer's grade <or= 2. 11.3% (inferior) to 26.4% (superior) were anterior bowing of the peripheral portion of the iris, 27.7% (inferior) to 42.6% (superior) were iris insertion into seleral spur. The three aspects of the angle had significant differences in sex and age. CONCLUSION: The survey shows that the percentage of people with occludable angles increases significantly with age, and women with occludable angles are more than men. This result is important for us to make screening strategy of primary angle-closure glaucoma.

Adult↗
PubMed1998

[Studies on QSAR of the antibacterial agents quinolones: changing the parent nucleus influenced the activity].

By the method of AM1, quantum chemistry indexes of 16 compounds of quinoline, 1,8-naphthyridine and pyrido(2,3-C)pyridazine analogues were calculated and 4 QSAR equations were obtained. The results showed that the net charge of 4-carbonyl oxygen is highly correlated with the antibacterial activity in vitro, the correlation coefficient of the regressions are high(R > or = 0.96). The antibacterial activity in vitro is strongly influenced by the coplanarity of 3-carboxylic acid and the parent nucleus. In light of this study, a new parent nucleus of isothiazoleannexed quinolizine was proposed, which is expected to have much higher activity.

Bacteria↗
PubMed1997

Induction of apoptosis of metastatic mammary carcinoma cells in vivo by disruption of tumor cell surface CD44 function.

To understand how the hyaluronan receptor CD44 regulates tumor metastasis, the murine mammary carcinoma TA3/St, which constitutively expresses cell surface CD44, was transfected with cDNAs encoding soluble isoforms of CD44 and the transfectants (TA3sCD44) were compared with parental cells (transfected with expression vector only) for growth in vivo and in vitro. Local release of soluble CD44 by the transfectants inhibited the ability of endogenous cell surface CD44 to bind and internalize hyaluronan and to mediate TA3 cell invasion of hyaluronan-producing cell monolayers. Mice intravenously injected with parental TA3/St cells developed massive pulmonary metastases within 21-28 d, whereas animals injected with TA3sCD44 cells developed few or no tumors. Tracing of labeled parental and transfectant tumor cells revealed that both cell types initially adhered to pulmonary endothelium and penetrated the interstitial stroma. However, although parental cells were dividing and forming clusters within lung tissue 48 h following injection, >80% of TA3sCD44 cells underwent apoptosis. Although sCD44 transfectants displayed a marked reduction in their ability to internalize and degrade hyaluronan, they elicited abundant local hyaluronan production within invaded lung tissue, comparable to that induced by parental cells. These observations provide direct evidence that cell surface CD44 function promotes tumor cell survival in invaded tissue and that its suppression can induce apoptosis of the invading tumor cells, possibly as a result of impairing their ability to penetrate the host tissue hyaluronan barrier.

Animals↗
PubMed1997

Avoiding interferences from Good's buffers: A contiguous series of noncomplexing tertiary amine buffers covering the entire range of pH 3-11.

Of the 20 well-known buffers proposed by Good, all but 3 form metal ion complexes which can result in serious interferences, particularly in protein analyses. The structural features responsible for such complex formation have been identified. Based on a mechanistic analysis of the metal complexation process, it is proposed that tertiary amine compounds, having N-substituents which are ethyl or larger, are sterically inaccessible for initial bond formation with solvated metal ions in aqueous solution. Thus, in the absence of donor atoms on the alpha-, beta-, or gamma-carbons, metal complexation cannot proceed. The proposed noncomplexing compounds include Good's 3 noncomplexing buffers (Mes, Mops, Pipes) plus six related species. Mixed-mode acid dissociation constants (hydrogen ion in terms of activity, conjugate acid-base species in molar concentrations) have been determined for all compounds in their protonated form at 25 degrees C, mu = 0.10 M (NaNO3). The values for four compounds in this series are reported here for the first time: viz., N,N'-diethylpiperazine for which log Ka1m = 4.67 +/- 0. 03 and log Ka2m = 8.83 +/- 0.02; N,N,N',N'-tetraethylmethylenediamine for which log Ka1m < 1 and log Ka2m = 11.01 +/- 0.03; N,N'-diethyl-N,N'-bis(3-sulfopropyl)ethylenediamine for which log Ka1m = 5.75 +/- 0.03 and log Ka2m = 9.37 +/- 0.02; and piperazine-N,N'-bis(2-ethanesulfonic acid) (Pipes) for which log Ka1m = 2.81 +/- 0.01 (the value of log Ka2m having been previously reported).

Amines↗
PubMed1997

Two COOH-terminal truncated cytoplasmic forms of topoisomerase II alpha in a VP-16-selected lung cancer cell line result from partial gene deletion and alternative splicing.

Topoisomerase II alpha is a nuclear enzyme involved in chromosome segregation and other essential cellular processes. It is also the target of several clinically important antineoplastic agents such as the epipodophyllotoxin, VP-16 (etoposide). We have previously described a VP-16-selected lung cancer cell line, H209/V6, that expresses reduced levels of two species of topoisomerase II alpha-related mRNAs and a catalytically active, predominantly cytoplasmic topoisomerase II alpha-related protein that is 10 kDa smaller than the wild-type protein [Mirski, S. E. L., et al. (1993) Cancer Res. 53, 4866-4873; Feldhoff, P. W. et al. (1994) Cancer Res. 54, 756-762]. The smaller H209/V6 4.8 kb mRNA is missing 988 nucleotides of contiguous coding and non-coding sequence at its 3' end resulting in an mRNA predicted to encode a truncated polypeptide missing three previously unrecognized potential COOH-proximal bipartite nuclear localization signals [Mirski, S. E. L., & Cole, S. P. C. (1995) Cancer Res. 55, 2129-2134]. We have now determined the structure of the larger 6.2 kb topoisomerase II alpha-related mRNA and show that it is missing 684 nucleotides of contiguous 3' coding and non-coding sequence between nucleotide positions 4267 and 4951. This sequence is replaced by 847 nucleotides of new sequence, containing an in-frame stop codon after 41 nucleotides. The translation product of the 6.2 kb mRNA is predicted to contain 13 new amino acids replacing the COOH-terminal 109 residues of wild-type topoisomerase II alpha, producing a truncated polypeptide of approximately 160 kDa. Immunoblot analyses using antisera against the unique COOH-terminal 13 and 34 amino acids encoded by H209/V6 6.2 kb and 4.8 kb mRNAs, respectively, confirmed that both mRNAs are translated. Restriction enzyme analysis and sequencing of the 3'-proximal region of the TOP2A gene in the H209 and H209/V6 DNA revealed that a partial deletion has occurred in H209/V6 and the novel sequence identified in the H209/V6 6.2 kb mRNA is derived from the adjacent 3' intron as a consequence of read-through at a concensus splice donor site. These observations suggest a mechanism for the generation of the two mutant topoisomerase II alpha mRNAs in H209/V6 cells and provide the first reported example of a drug resistant cell line containing two different cytoplasmic forms of topoisomerase II alpha.

Amino Acid Sequence↗
PubMed1997

Common pattern of CD44 isoforms is expressed in morphogenetically active epithelia.

CD44 is a widely distributed cell surface glycoprotein that is expressed as many isoforms arising from a single gene by alternative splicing. An important ligand for the widespread CD44 isoform, CD44s (standard form of CD44), is hyaluronan but ligands for the numerous variant isoforms are not as well characterized. Although it has been documented that CD44 is present at critical sites and stages of morphogenesis of several organs, the nature of the isoforms expressed and their precise localization have not been described. In this study we have determined the identity and distribution of CD44 isoforms expressed during development of several embryonic mouse organs by a combination of immunohistochemistry, in situ hybridization, reverse transcription-polymerase chain reaction, and DNA sequencing. As expected from previous studies, numerous CD44 variants are expressed by actively proliferating and invaginating epithelia at sites of epithelial-mesenchymal interaction, e.g., in the developing tooth, nose and hair follicle. Our results show that most prominent amongst these variants at these sites are CD44(v3-v10), CD44(v4-v10), and CD44(v6-v10), as was also found previously in the apical ectodermal ridge of the developing limb (Yu et al. [1996]). The common pattern of expression of these three particular variants in active epithelia implies that they play an important role in morphogenesis. Also very prominent in morphogenetically active epithelia is CD44s; hyaluronan is uniformly absent from these epithelia and often also from associated mesenchyme with which they interact, supporting the previously documented role of CD44s in endocytic removal of hyaluronan.

Animals↗
PubMed1997

Internal lethal concentrations of halobenzenes with fish (Gambusia affinis).

The internal lethal concentrations is a potential measure of toxicity which could be usefully applied in environmental toxicology and risk assessment. Using halobenzenes, which are common environmental contaminants, and represented test compounds, experiments were conducted in aquaria with the mosquitofish (Gambusia affinis). The average internal lethal concentration (ILC50) for four representative halohydrocarbons, 1,4-diBB, 1,2,3-triCB, 1,2,4-triBB, and pentaCB, were consistent with those previously observed, i.e., 2.3-8.3 mmol kg-1 fish over exposure time periods of 10.4 to 633 hr. However, the ILC50 for all the compounds is not constant but decreases with increasing exposure time period with a mean first-order rate constant of (4.21 +/- 0.70) x 10-3 hr-1. The time dependency of the ILC50 is inconsistent with the critical internal concentration hypothesis which requires the ILC50 to reach a constant critical value when lethality occurs. The life expectancy of the fish from the beginning of chemical exposure could possibly be related to the ILC50-exposure time relationship.

Animals↗
PubMed1997

Modulation and detection of IDDM by membrane associated antigens from the islet beta cell line NIT-1.

We have utilized the NOD islet beta-cell line NIT-1 to monitor beta-cell specific autoantibodies and to investigate the modulation of IDDM in NOD mice by NIT-1 membrane associated antigens. The sera from diabetic but not from pre-diabetic or protected NOD mice strongly stained NIT-1 cells in FACS analysis. The cell surface antigens on NIT-1 cells were trypsin-sensitive. NIT-1 cells could not be stained by anti-mouse GAD67 antibody; however, we could demonstrate the presence of GAD65 and GAD67 mRNA by RT-PCR. Longitudinal analysis of anti-NIT-1 antibodies showed that these antibodies were present in the neonates but disappeared after weaning. Sonicated NIT-1 cell membrane preparations protected NOD mice from diabetes when injected intravenously in 5 week old mice. The protection was associated with reduced cytotoxic activity and elevated Th2-like responses as indicated by IgG1 antibodies against the NIT-1 cells. Subcutaneous injection of sonicated NIT-1 membranes or the injection of control red blood cell membranes failed to induce protection. We conclude that NIT-1 cell membranes do not express GAD but contain other antigens that are important in the development and prevention of IDDM. These antigens could be useful for the diagnosis of diabetes by monitoring autoantibody levels and for the modulation of IDDM by immunotherapy.

Animals↗