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Biomedical subjects

Bin Yang

Publications and source records attributed to Bin Yang.

108 records · Page 6Linked to original sources
PubMed2003

[Subretinal transplantation of retinal cells by outer approach].

OBJECTIVE: To investigate the approaches and effect of pure retinal photoreceptor cells and mixed retinal cells subretinal transplantation on retinal degenerative diseases. METHODS: 16 Kunming mice were divided into two groups: group A and group B (n = 8). Through sclera and choroid, mixed retinal cells were injected into the subretinal space of mice eyes of group A and pure retinal photoreceptors were injected into the subretinal space of mice eyes of group B by using a specific micro-syringe under operative microscopy. 30, 90 and 180 d after transplantation, experimental eyes were enucleated, stained with HE and analyzed by light microscopy. RESULTS: Most transplants (13/15) were exactly in host subretinal space without the infiltration of inflammatory cells and interfere of retina. The infiltration of inflammatory cells and damage of retina were only found in few eyes (2/15). The transplanted retinal cells survived well at 180 days after transplantation. The mixed retinal cells all formed rosette, but the pure retinal photoreceptors formed an orderly layer of photoreceptors. CONCLUSIONS: This specific technique of subretinal microinjection is an easy, safe and optimal technique to meet the need of subretinal drug administration and retinal cells transplantation for retinal degenerative diseases. It is easier for the transplanted pure retinal photoreceptor cells to establish functional connection with host cells through subretinal microinjection.

Animals↗
PubMed2003

[Determining the quantity of hypericin in medicinal materials and asepsis seedings of Hypericum perforatum by HPLC].

OBJECTIVE: To establish the method of determining the quantity of hypericin in Hypericum perforatum and determine the quantity of the hypericin in defferent medicinal materials and asepsis seedings which grow in defferent environment. METHOD: The specimen is extracted with methanol--Pyridine (9:1) ultrasound extraction. Chromatographic assay is performed on a hypersily ODS2 (4.6 mm x 150 mm, 5 microm) column. The mobile phase is composed of methanol -1.56% dihydric natrium phosphate hydrogen natrium solution (shift solution's acidity to 2.1 with phosphoric acid)--ethyl acetate (4:1.9:1), velocity of flow is 1 mL x min(-1); column temperature is 35 degrees C; the detection wavelength is 590 nm. RESULT: A satisfactory seperaration between hypericin and impurity. The calibration curve is linear over the range of 0.0524-0.2620 microg for hypericin (r = 0.9998). The average recovery of hypericin is 97.50%. CONCLUSION: The quantity of hypericin in Hypericum perforatum has something to do with the genetic factor, environment factor, growing period and dry means. The method of determining the quantity of hypericin can be regarded as the method of controling the quantity of medicinal materials.

Anthracenes↗
PubMed2002

Potent suppression of viral infectivity by the peptides that inhibit multimerization of human immunodeficiency virus type 1 (HIV-1) Vif proteins.

Virion infectivity factor (Vif) is essential for the replication of human immunodeficiency virus type 1 (HIV-1) in vivo, but its function remains uncertain. Recently, we have shown that Vif proteins are able to form multimers, including dimers, trimers, or tetramers. Because the multimerization of Vif proteins is required for Vif function in the viral life cycle, we propose that it could be a novel target for anti-HIV-1 therapeutics. Through a phage peptide display method, we have identified a set of 12-mer peptides containing a PXP motif that binds to HIV-1 Vif protein. These proline-enriched peptides potently inhibited the Vif-Vif interaction in vitro. We have also screened a set of synthesized Vif peptides (15-mer), which covers all the amino acids of the HIV-1 Vif protein sequence, for their ability to inhibit the Vif-Vif interaction in vitro. We demonstrated that Vif-derived proline-enriched peptides that contain the (161)PPLP(164) domain are able to inhibit the Vif-Vif interaction. Conversely, the deletion of the (161)PPLP(164) domain of Vif protein will significantly impair the capability of Vif proteins to interact with each other, indicating that the (161)PPLP(164) domain plays a key role in Vif multimerization. All these results demonstrate that the proline-enriched peptides block the multimerization of Vif through interfering with the polyproline interfaces of Vif formed by (161)PPLP(164) domain. Moreover, these peptides which inhibit the Vif-Vif interaction in vitro potently inhibit HIV-1 replication in the "nonpermissive" T-cells. We propose that this study starts a novel strategy to develop structural diverse inhibitors of Vif such as peptidomimetics or small organic molecules.

Amino Acid Sequence↗
PubMed2002

Studies on the transition behavior of physical adsorption from the sub- to the supercritical region: experiments on silica gel.

Adsorption equilibria of nitrogen and methane on a mesoporous silica gel were measured over a temperature range from the sub- to the supercritical region. Determination of the compressibility factor shows a significant effect on the experimentally measured isotherms under conditions rho(g)/rho(c)>0.3. The transition of adsorption mechanisms in passing over the critical temperature was proven by the transformation of isotherms from type II to type I. The characteristic feature of subcritical adsorption was still observed at a temperature 8 K higher than the critical and the critical depletion phenomenon was clearly shown on such an isotherm. The limit quantities defined in different ways for the supercritical adsorption are in reasonable agreement, indicating the existence of an upper limit state of the supercritical adsorbate.

Journal Article↗
PubMed2002

[Epidemiological survey on epilepsy among rural populations in five provinces in China].

OBJECTIVE: To investigate the prevalence of epilepsy and its treatment gap in rural areas of China. METHODS: A door-to-door epidemiological survey on epilepsy was conducted among 55616 rural residents in 5 counties, each in a province (Heilongjiang, Ningxia, Shanxi, Henan, and Jiangsu) selected by random cluster sampling. All people diagnosed or suspected as epileptic during the screening phase were rechecked by neurologists. RESULTS: A definite diagnosis of epilepsy was made among 387 people with a prevalence rate 7.0 per thousand (age-adjusted rate 6.8 per thousand). The prevalence of active epilepsy was 4.6 per thousand, and the incidence of epilepsy was 28.8/100 000. Of the people with epilepsy, 40.6% had not been treated, 35.4% were treated irregularly. The treatment gap of active epilepsy was 62.6%. CONCLUSION: The prevalence of epilepsy in the rural areas in China was much higher than it was reported previously. About two thirds of the patients with epilepsy has not received regular treatment. A rational intervention strategy should be developed as soon as possible.

Adolescent↗
PubMed2002

Fast and efficient alkaline peroxide treatment to enhance the enzymatic digestibility of steam-exploded softwood substrates.

The enzymatic digestibility of steam-exploded Douglas-fir wood chips (steam exploded at 195 degrees C, 4.5 min, and 4.5% (w/w) SO(2)) was significantly improved using an optimized alkaline peroxide treatment. Best hydrolysis yields were attained when the steam-exploded material was post-treated with 1% hydrogen peroxide at pH 11.5 and 80 degrees C for 45 min. This alkaline peroxide treatment was applied directly to the water-washed, steam-exploded material eliminating the need for independent alkali treatment with 0.4% NaOH, which has been traditionally used to post-treat wood samples to try to remove residual lignin. Approximately 90% of the lignin in the original wood was solubilized by this novel procedure, leaving a cellulose-rich residue that was completely hydrolyzed within 48 h, using an enzyme loading of 10 FPU/g cellulose. About 82% of the originally available polysaccharide components of the wood could be recovered. The 18% of the carbohydrate that was not recovered was lost primarily to sugar degradation during steam explosion.

Cellulose↗
PubMed2002

CD10 facilitates the diagnosis of metastatic renal cell carcinoma from primary adrenal cortical neoplasm in adrenal fine-needle aspiration.

Renal cell carcinoma (RCC) frequently metastasizes or invades the adrenal gland. Metastatic RCC is often difficult to differentiate from primary adrenal cortical neoplasm (ACN) in an adrenal fine-needle aspiration (FNA). Recently, CD10 immunoreactivity was observed in more than 90% of RCC, but none in primary ACN. To facilitate the accurate diagnosis of metastatic RCC in adrenal FNA, we retrospectively studied the cytomorphology and CD10 immunohistochemistry in 20 cases of FNA specimens, including 10 cases of adrenal FNA (six cases of metastatic RCC and four cases of primary ACN) and 10 cases of primary RCC. Cytomorphologically, several overlapping features were observed between primary ACN and metastatic RCC, including: abundant clear cytoplasm, often with microvesicles, large nuclei with prominent nucleoli, bare nuclei, and prominent vascularity. Immunostaining for CD10 was positive in 9/10 cases of primary RCC, 5/6 cases of metastatic RCC in the adrenal gland, and 0/4 cases of primary ACN. Our study indicates that: 1) an accurate diagnosis of ACN in FNA specimens can often be difficult due to overlapping cytomorphologic features with RCC, and 2) CD10 immunostaining is helpful in separating metastatic RCC from a primary ACN and can reliably be performed on a cytologic sample.

Adenocarcinoma, Clear Cell↗
PubMed2002

A shift in the Bax/Bcl-2 balance may activate caspase-3 and modulate apoptosis in experimental glomerulonephritis.

BACKGROUND: Although apoptosis has been linked to the renal cell deletion and ensuing renal fibrosis, its regulating mechanisms remain obscure. Of the known regulators of apoptosis, the best characterized is the Bax to Bcl-2 ratio. However, its importance in controlling apoptosis in glomerulonephritis is unclear. Here, using the nephrotoxic nephritis (NTN) model, we evaluated Bax/Bcl-2 in relation to changes in the apoptosis co-ordination enzyme, caspase-3. METHODS: Kidneys were harvested at days 7, 15, 30 and 45 post-injection of anti-glomerular basement membrane antibody into Wistar Kyoto rats. These were analyzed for apoptosis (in situ end labeling of fragmented DNA, light and electron microscopy), Bax/Bcl-2 protein (Western blotting), mRNA (Northern blotting) and distribution (immunohistochemistry), as well as caspase-3 activity (substrate cleavage assay), inflammation (ED1 staining), proliferation (proliferating cell nuclear antigen staining) and fibrosis (Masson's Trichrome staining). RESULTS: Bax mRNA was significantly increased while that of Bcl-2 was decreased throughout the time course (+265% and -62% by day 45). Increased Bax and decreased Bcl-2 protein were noted, significantly so on day 7 (+177% and -21%) and day 45 (+363% and -17%). Bax protein was observed in dilated and atrophic tubules, sclerotic glomeruli and inflamed interstitium, while Bcl-2 was only visible in atrophic tubules. The ratios of Bax to Bcl-2 mRNA and protein were significantly increased at all time points. These correlated (P < 0.05) with up-regulated caspase-3 activity (r = 0.742 and 0.531), apoptosis (r = 0.712 and 0.540), proliferation (r = 0.611, mRNA only), inflammation (ED1+, r = 0.474 and 0.419) and fibrosis (r = 0.474 and 0.729). CONCLUSIONS: Our findings suggest that the changes in the ratio of Bax to Bcl-2 may contribute to the caspase-3 activation and the modulation of renal apoptosis associated with renal inflammation, tubular atrophy and renal fibrosis in experimental glomerulonephritis.

Animals↗
PubMed2002

Primary cutaneous diffuse large B-cell lymphoma: a clinicopathologic study of 15 cases.

Primary cutaneous diffuse large B-cell lymphoma (DLBCL) is an uncommon lymphoma. Some authors have suggested that large B-cell lymphoma can be segregated based on anatomic site, with tumors of the lower extremity being unique. We report 15 cases of primary cutaneous DLBCL. Each case was analyzed immunohistochemically using antibodies specific for CD3, CD5, CD10, CD20, bcl-2, bcl-6, and p53. Polymerase chain reaction analysis for t(14;18)(q32;q21) also was performed. There were 13 men and 2 women (median age, 64 years). Thirteen tumors were composed predominantly of centroblasts, and 2 were immunoblastic. There was a median follow-up of 72 months. Of the 4 patients with primary cutaneous DLBCL of the lower extremity (thigh, knee, leg), 2 (50%) experienced a recurrence and 1 patient died of disease. In the non-lower extremity cases, 18% (2/11) recurred and no patients died of disease. We conclude that primary cutaneous DLBCL usually occurs in elderly patients with a male predominance. Recurrences are common, but death of disease is rare.

Antigens, CD↗
PubMed2002

Cellulase adsorption and an evaluation of enzyme recycle during hydrolysis of steam-exploded softwood residues.

The sugar yield and enzyme adsorption profile obtained during the hydrolysis of SO2-catalyzed steam-exploded Douglas-fir and posttreated steam-exploded Douglas-fir substrates were determined. After hot alkali peroxide posttreatment, the rates and yield of hydrolysis attained from the posttreated Douglas-fir were significantly higher, even at lower enzyme loadings, than those obtained with the corresponding steam-exploded Douglas-fir. The enzymatic adsorption profiles observed during hydrolysis of the two substrates were significantly different. Ultrafiltration was employed to recover enzyme in solution (supernatant) and reused in subsequent hydrolysis reactions with added, fresh substrate. These recycle findings suggested that the enzyme remained relatively active for three rounds of recycle. It is likely that enzyme recovery and reuse during the hydrolysis of posttreated softwood substrates could lead to reductions in the need for the addition of fresh enzyme during softwood-based bioconversion processes.

Adsorption↗
PubMed2002

[The early changes of tear film after laser in situ keratomileusis].

OBJECTIVE: To investigate the early changes of tear film after laser in situ keratomileusis (LASIK). METHODS: One hundred and forty-eight myopic eyes that underwent LASIK were randomly chosen. The eyes were observed for subjective complaints of dry eye, fluorescein staining (Fl), rose bengal staining (Rb), tear break-up time (BUT), Schirmer's I test preoperatively and 1 day, 1 week, 1 month, 3 months postoperatively. RESULTS: The subjective complaints of dry eye were more severe after the operation. There were obvious decreases in BUT at 1 day, 1 week, 1 month and 3 months postoperatively relative to the preoperative level (P < 0.05). The Schirmer's I test result was higher at 1 day but without statistical significance (P > 0.05), but lower at 1 week, 3 months (P < 0.05) after LASIK. No changes were observed in Schirmer's I test between preoperative and 1 month postoperative value (P > 0.05). Rb and Fl staining dots were more concentrated at 1 day and 1 week postoperatively (P < 0.0127). No significant changes were found in Rb staining at 1 month and 3 months postoperatively. CONCLUSION: LASIK does have some effects on tear film.

Adolescent↗
PubMed2002

[One-stage repair of hypospadias using a scrotal septal skin flap based on peri-meatus dartos fascia].

OBJECTIVE: To explore the feasibility of one-stage repair of hypospadias using scrotal septal skin flap based on peri-meatus dartos fascia. METHODS: Nine patients were repaired by this method. RESULTS: All patients achieved good results without urethral fistula or stricture. The angle of the penis to the scrotum is normal. CONCLUSION: The flap has reliable blood supply and the flap creation is easy. It is a simple, convenient and effective method for one-stage repair of hypospadias.

Adolescent↗
PubMed2002

[Study on relationship between Arg778Leu/Gln gene mutation spot in ATP7B and TCM syndrome type in Chinese patients with Wilson disease].

OBJECTIVE: To investigate the relationship between Arg778Leu/Gln gene mutation spot in ATP7B and TCM Syndrome type in Chinese patients with Wilson disease (WD). METHODS: Exon 8 of ATP7B of 90 WD patients and 30 healthy controls were amplified by PCR and analysed by restriction enzyme Msp I, the TCM Syndrome type of the patients was differentiated at the same time. RESULTS: In the 90 WD patients, 34 with Arg778Leu/Gln of exon 8 were detected, among them 20 cases belonged to the TCM Syndrome type of endogenous Liver-Wind agitation. CONCLUSION: Onset age of WD patients with Arg778Leu/Gln mutation is later than that without this mutation. Arg778Leu/Gln mutation might be related to the TCM Syndrome type of endogenous Liver-Wind agitation.

Adenosine Triphosphatases↗
PubMed2001

Determination of the Adsorbed Phase Volume and Its Application in Isotherm Modeling for the Adsorption of Supercritical Nitrogen on Activated Carbon.

Experimental excess adsorption isotherms of nitrogen on activated carbon were measured in the range of 103-298 K and pressures up to 10 MPa. A method for determining the volume of the adsorbed phase from the experimental data for the supercritical temperatures was proposed. Such a volume with a new isotherm equation was used in modeling experimental excess isotherms, and a satisfactory fit was achieved. Copyright 2001 Academic Press.

Journal Article↗
PubMed2001

Expression of apoptosis-related genes and proteins in experimental chronic renal scarring.

Apoptosis has been proposed to play an important role in the progression of renal scarring. The mechanisms that determine whether a cell enters the apoptotic program are complex. Bax and Bcl-2 are recognized modulators of this event; their relative levels determine the fate of cells. A role for apoptosis in the progression of renal scarring in the remnant kidneys of rats submitted to subtotal nephrectomy (SNx) has been described. This study investigated the expression (protein and mRNA) of Bax and Bcl-2 in remnant kidneys between day 7 and day 120 post-SNx. Northern blot analysis showed that bax mRNA was increased in remnant kidneys from day 7 (150% of control; P: < 0.05), whereas bcl-2 mRNA was decreased from day 15 (23% of control; P: < 0.05) resulting in a 14-fold increase in the ratio of bax to bcl-2 mRNA by day 120. Western blot analysis showed similar changes in Bax and Bcl-2 protein in remnant kidneys, resulting in a 147-fold increase in the ratio of Bax to Bcl-2 on day 120. Immunohistochemistry showed increases in Bax to be located predominantly in tubules in SNx kidneys. Interestingly, Bcl-2 immunostaining increased in some epithelial cells within atrophic tubules despite the overall decrease in Bcl-2 protein and mRNA. The overall renal apoptotic cells correlated closely with the ratio of bax to bcl-2 at both the mRNA and protein levels (r = 0.594 and 0.308, respectively; P: < 0.05). Furthermore, tubular apoptosis correlated positively with the mRNA level of bax (r = 0.471; P: < 0.01) and negatively with the mRNA and protein levels of bcl-2 (r = -0.443 and -0.607, respectively; P: < 0.01). The increase in the ratio of the death inducer (Bax) to the death repressor (Bcl-2) at the mRNA and protein levels may control the apoptosis associated with the progression of tubular atrophy and chronic renal fibrosis within remnant rat kidneys. These observations may have prognostic and therapeutic implications in chronic renal failure.

Animals↗
PubMed2001

Apoptosis and caspase-3 in experimental anti-glomerular basement membrane nephritis.

The caspase family is central to the proteolytic events of apoptosis. In particular, caspase-3 plays a key role in the execution of apoptosis. However, the importance of caspase-3 in renal cell apoptosis during kidney scarring has not been established. Here, nephrotoxic nephritis (NTN) was induced in Wistar Kyoto rats by a single intravenous injection of rabbit anti-rat glomerular basement membrane serum, with analysis at days 7, 15, 30, and 45 after injection. Cell apoptosis (in situ end labeling of DNA, light and electron microscopy), proliferation (proliferating cell nuclear antigen-positive cells), and inflammation (ED1-positive cells) all increased in NTN kidneys, peaking early (day 7) in the glomeruli and later (days 30 to 45) in the tubules and interstititum. The expression of caspase-3 mRNA (Northern blotting) was increased in NTN kidneys on days 7, 30, and 45 (173.3%, 228%, and 241.7%, respectively; P< 0.05). Western blotting showed that a 24-kD protein band (caspase-3 active subunit) increased with time in NTN kidneys (P < 0.01) and reached a maximum on day 45 (6.08-fold increase). A 32 kD band (caspase-3 precursor) was also increased on day 45 (3.92-fold; P<0.01). Elevated caspase-3 activity (two- to threefold) was observed in NTN kidneys at all time points (P< 0.01). Upregulated expression of caspase-3 at all levels positively correlated with apoptosis, whereas both correlated closely with inflammation, proliferation, and subsequent fibrosis in glomeruli, tubules, and interstitium (P< 0.05). Inhibition of caspase-3 during the course of experimental nephritis may offer a new therapeutic approach for the prevention of renal apoptosis and the associated renal tubular atrophy and fibrosis.

Animals↗