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Biomedical subjects

B Yang

Publications and source records attributed to B Yang.

441 records · Page 25Linked to original sources
PubMedDate not supplied

Venous aneurysms: MR diagnosis with the "layered gadolinium" sign.

OBJECTIVE: Our goal was to present MR findings in venous aneurysms and introduce the "layered gadolinium" sign as an ancillary diagnostic finding. METHOD: Gadolinium-enhanced MR images of three patients with retroperitoneal venous aneurysms were retrospectively reviewed. Prior to MRI, venous aneurysm had been suspected clinically in only one patient. Surgical correlation was available in one patient. A phantom was constructed and imaged to investigate the cause of the layered gadolinium sign. RESULTS: A gradation of signal intensity, the layered gadolinium sign, was observed in three patients with venous aneurysms on postcontrast T1-weighted images. The anterior portion of the aneurysms demonstrated high signal intensity separated by a sharp interface from the low signal intensity posterior region. Unenhanced time-of-flight MR venography, color Doppler, and duplex sonography failed to demonstrate flow in the patient with surgical proof. CONCLUSION: The layered gadolinium sign may be helpful in the diagnosis of venous aneurysm and in differentiating these masses from solid neoplasms.

Aged↗
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Methylation status of the fragile histidine triad and E-cadherin genes in plasma of cervical cancer patients.

Recent evidence suggests that tumor cells may release DNA into the serum and plasma of afflicted cancer patients. However, no report existed regarding the methylation status of the fragile histidine triad (FHIT) and E-cadherin genes in plasma samples of cervical cancer patients. Methylation-specific PCR (MSP) was employed to examine CpG island methylation of the FHIT and E-cadherin genes in 151 pretreatment plasma samples and 30 tumor tissue samples from cervical cancer patients. MSP products were cloned and sequenced. CpG island methylation of the FHIT and E-cadherin genes was detected in 30.46% and 39.74% of plasma samples, respectively, and in 53.33% and 60.0% of tissue samples, respectively. The total concordance rate of methylation between plasma samples and tissue samples in FHIT gene was 80.00% and that in E-cadherin gene was 76.66%. At least one of the two methylated genes was detected in 56.29% of plasma samples and 76.7% of tissue samples. The presence of both methylated genes was detected in 13.9% of plasma samples and 36.67% of tissue samples. We found that the higher the clinical stage and histologic grade, the higher the rate of methylation in both genes in plasma samples. CpG island methylation of the FHIT and E-cadherin genes is present in plasma of cervical cancer patients. Using the two genes as markers simultaneously may allow clinicians to diagnose and evaluate the effect of treatment earlier and using fewer invasive procedures.

Acid Anhydride Hydrolases↗
PubMedDate not supplied

Role of apoptosis and Bcl-2/Bax in the development of tubulointerstitial fibrosis during experimental obstructive nephropathy.

BACKGROUND/AIMS: To examine the role of apoptosis in experimental unilateral ureteral obstruction (UUO). METHODS: Rat kidneys were examined 3, 7 and 11 days following UUO or sham operation (SO). Tissue was immunohistochemically stained for alpha-smooth muscle actin (alpha-SMA), proliferating cell nuclear antigen (PCNA), Bcl-2 and Bax proteins. Apoptotic analysis was carried out in kidney sections using in situ end labelling of endonuclease cleaved DNA. RESULTS: The relative volume (Vv) of cortical interstitium and interstitial alpha-SMA increased progressively following UUO. ED1-positive monocytes/macrophages peaked at day 7 and significantly decreased at day 11. PCNA-positive cells in tubulointerstitium were significantly increased on day 3. Staining returned to the level of the SO group by day 11, meanwhile those in the interstitium remained much higher than baseline. TUNEL-positive cells were persistently raised following UUO. Transient tubular cell proliferation seemed unable to counteract the apoptosis since tubular atrophy was apparently present by day 11 of UUO. However, interstitial cell proliferation was high enough to overwhelm apoptosis, particularly with respect ot myofibroblasts, since alpha-SMA immunostaining and Vv remained elevated. The ratio of the number of PCNA-positive cells to apoptotic cells formed a predictive pattern for the staining score of interstitial alpha-SMA (R(2) = 47.23%, p < 0.05) and Vv (R(2) = 49.93%, p < 0.05). Tubular Bcl-2 immunostaining peaked on day 3, and then gradually decreased to baseline by day 11. The expression of Bax protein was inhibited on day 3 when compared with that of the SO group, but increased with time following UUO. CONCLUSION: These findings suggest an important role for apoptosis and its regulatory proteins in the processes of tubular atrophy and fibrogenesis following UUO.

Actins↗
PubMedDate not supplied

Comparison of laser in situ keratomileusis and photorefractive keratectomy to correct myopia from -1.25 to -6.00 diopters.

BACKGROUND: We evaluated the safety and efficacy of laser in situ keratomileusis (LASIK) for the correction of low to moderate amounts of myopia (-1.25 to -6.00 D). METHODS: Photorefractive keratectomy (PRK) was performed on 432 eyes and LASIK on 137 eyes with a Chiron Keracor 116 excimer laser. Uncorrected and corrected visual acuity, corneal sensitivity, contrast sensitivity, and corneal topography were examined before and after surgery. RESULTS: One-year follow-up of 307 eyes in the PRK group and 103 eyes in the LASIK group was achieved. At 1 year, 83% (85 of 103) of LASIK eyes and 72% (221 of 307) of PRK eyes had an uncorrected visual acuity of 1.0 or better. Eighty-nine percent (92 of 103) of LASIK eyes and 83% (255 of 307) of PRK eyes had a refractive error within +/- 1.00 D of emmetropia; 71% (73 of 103) of LASIK eyes and 61% (188 of 307) of PRK eyes were within +/- 0.50 D of emmetropia. Contrast sensitivity and corneal sensitivity were reduced in both groups at the early postoperative stage but gradually returned to preoperative values; their recovery took about 3 months in LASIK eyes and 6 to 12 months in PRK eyes. CONCLUSION: LASIK is safe and more predictable than PRK to correct low to moderate amounts of myopia. Recovery from LASIK is faster than after PRK.

Contrast Sensitivity↗
PubMedDate not supplied

Hair photoprotection by dyes.

We have found that hair dyes protect hair against photodamage. The efficacy of photoprotection of dye products has been measured by monitoring the tensile strength of hair fibers and the integrity of the disulfide bonds in the fibers. Although the hair dyed with permanent dye products are initially weakened due to oxidative chemical damage, they also show a slower rate of degradation upon photoirradiation, compared to the undyed hair. Thus, a less appreciated benefit of using hair colors is their ability to provide protection against sun damage.

Hair↗
PubMedDate not supplied

Chemical and photo-oxidative hair damage studied by dye diffusion and electrophoresis.

Microspectrophotometric and electrophoretic methods were used to characterize and quantify the effects of primary damage to hair from chemical and photochemical oxidative processes. The diffusion of molecules proceeding from the fiber surface to the center of untreated and modified (by chemical and photochemical oxidative processes) hair fibers was mapped by fluorescence microscopy and quantified by calculating diffusion coefficients of a fluorescent molecule. In addition, an electrophoretic separation technique, namely, SDS-PAGE (sodium dodecyl sulfate-polyacrylamide gel electrophoresis), was used not only to substantiate the results obtained in the microfluorometric study, but also to show how the main classes of proteins of unaltered hair are modified by cosmetic chemical treatments, light exposure, and combinations of these two processes. UV microspectrophotometry is an alternate analytical method to evaluate photo-oxidative damage in hair, and supports the results obtained by microfluorometry.

Diffusion↗
PubMedDate not supplied

Isolation and identification of chicken infectious anemia virus in China.

A chicken infectious anemia virus (CIAV) isolate was obtained from broiler flocks aged 25-40 days with anemia and poor performance and was designated SR43. The CIAV isolate was resistant to treatment with chloroform and induced thymus atrophy, bone marrow aplasia, and low hematocrit values when inoculated into 1-day-old, susceptible, specific-pathogen-free chicks. CIAV-specific antigens could be demonstrated in SR43-infected MDCC-MSB-1 cells, a cell line derived from a Marek's disease lymphoma, with the use of a monoclonal antibody specific for CIAV. CIAV DNA in infected MDCC-MSB-1 cell cultures was detected by using a polymerase chain reaction assay. These findings demonstrate that CIAV is present in China.

Animals↗