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Biomedical subjects

P Yang

Publications and source records attributed to P Yang.

At least 91 records · Page 5Linked to original sources
PubMed2001

Trochanteric rotational osteotomy for osteonecrosis of the femoral head.

The rate of success of transtrochanteric rotational osteotomy for osteonecrosis of the femoral head may be improved if patients are preselected using MRI. We have used three criteria for selection for osteotomy (i) minor collapse of the infarcted area, loss of congruity or the crescent sign, without narrowing of the joint space or acetabular involvement (ii) patients younger than 55 years and with a painful hip (iii) patients with an intact area constituting an arc of more than 120 degrees between the central vertical line of the femoral head and the posterior or anterior margin of the necrotic portion as seen on a midsagittal MRI. Seventeen patients were selected, with a follow-up of more than 42 months. A bone scan four weeks after operation showed adequate perfusion of the proximal segment in all hips. The hip score of Merle d'Aubigné et al improved from 13.5 points before operation to 17.2 points at the latest follow-up. Further collapse of the femoral head did not occur. The use of MRI instead of plain radiographs for the selection of patients has improved the success rate of transtrochanteric rotational osteotomy.

Adolescent↗
PubMed2001

Fermentation and costs of fuel ethanol from corn with Quick-Germ process.

The Quick-Germ process developed at the University of Illinois at Urbana-Champaign is a way to obtain corn oil, but with lower capital costs than the traditional wet-milling process. Quick-Germ has the potential to increase the coproduct credits and profitability of the existing dry-grind fuel ethanol process, but the fermentability of the corn remaining after oil recovery has not been tested. Therefore, a series of pilot scale (50 L) fermentations was carefully controlled and monitored with unique methods for standard inoculation and automatic sampling. It was found that the concentration of suspended solids was significantly reduced in the Quick-Germ fermentations. When compared at the same concentration of fermentable sugars, the fermentation rate and yield were not statistically different from controls. When Quick-Germ was integrated into a state-of-the-art dry-grind fuel ethanol process, computer simulation and cost models indicated savings of approx $0.01/L of ethanol ($0.04/gal) with the Quick-Germ process. Additional savings associated with the lower suspended solids could not be quantified and were not included. However, the savings are sensitive to the price of corn oil.

Biotechnology↗
PubMed2001

Induction of HLA-DR expression in human lamina cribrosa astrocytes by cytokines and simulated ischemia.

PURPOSE: Recent evidence strongly suggests that activated immunity occurs during the neurodegenerative process of glaucomatous optic neuropathy. Although activation of lamina cribrosa astrocytes has been identified in glaucomatous optic nerve head, their role on the activated immune responses seen in glaucoma patients is unknown. Here, the authors aimed to study the potential role of lamina cribrosa astrocytes as a component of activated immune responses seen in glaucoma patients. METHODS: Expression of HLA-DR in optic nerve head astrocytes was studied using immunohistochemistry in postmortem eyes of patients with glaucoma and normal donors. Serum cytokine levels of patients with glaucoma and control subjects were measured using enzyme-linked, immunosorbent assay. In addition, in vitro experiments were performed using astrocyte cultures derived from human optic nerve head or fetal human brain. The cultured astrocytes were incubated under selected stress conditions such as exposure to cytokines, IFN-gamma and IL-10, or simulated ischemia for up to 48 hours. The expression of HLA-DR was studied in these cells using flow cytometry and immunocytochemistry. RESULTS: Immunohistochemistry demonstrated an upregulation of the HLA-DR expression in the optic nerve head astrocytes in glaucoma. In addition, serum levels of IL-10 was higher in the patients with normal pressure glaucoma compared to age-matched control subjects (P: = 0.001). Regarding in vitro experiments, unlike brain astrocytes, the percentage of cells expressing HLA-DR was approximately 3 times higher in the cultures of optic nerve head astrocytes exposed to simulated ischemia compared to cultures incubated under normal conditions (P: = 0.09). Incubation with IFN-gamma induced HLA-DR expression in brain and lamina cribrosa astrocytes, up to 25-fold, (P < 0.001) either in the absence or presence of simulated ischemia. Induction of HLA-DR expression by IL-10 was approximately 6 times higher in lamina cribrosa astrocytes incubated under simulated ischemia compared to that incubated under normal condition (P: = 0.004) and was not prominent in brain astrocytes. CONCLUSIONS: These findings suggest that optic nerve head astrocytes function as antigen-presenting cells and that their immunogenic capacity is more sensitive to ischemia than brain astrocytes. Taken together, these findings provide novel evidence that regulation of immunogenic capacity of optic nerve head astrocytes by cytokines or ischemic stress may have a role during the neurodegeneration process in patients with glaucoma.

Aged↗
PubMed2001

[Comparison between porous polymer carrier and activated carbon carrier used for treating organic wastewater in anaerobic fluidized-bed reactor].

A comparative performance between porous polymer carriers (HP) and granular activated carbon carriers (GAC) in anaerobic fluidied-bed reactors was undertaken to evaluate their characters. The results showed that the COD removal and the biogas volume yield rate were 84% and 16.5 m3/(m3.d) respectively when HP was used as carrier to treat synthetic wastewater, at the top COD organic load rate of 65.5 kg/(m3.d), however those were 74.2% and 14.5% respectively for GAC carrier at the top load rate of 63.25 kg/(m3.d). The COD removal and biogas volume yield rate were 64.7%-54.5% and 1.89-2.7 m3/(m3.d) respectively when HP was used as carriers to treat straw pulping wastewater, at the load rate of 14.5-36.15 kg/(m3.d), and those were 61.0%-52.1% and 0.73-2.0 m3/(m3.d) respectively for GAC carriers at the load rate 9.16-19.06 kg/(m3.d). The study revealed that the HP carriers reactor is more efficient than the GAC carriers reactor in microbial immobilization and the wastewater treatment.

Anaerobiosis↗
PubMed2001

[Effects of fruits of Hovenia dulcis Thunb on acute alcohol toxicity in mice].

OBJECT: To study the effects of fruits of Hovenia dulcis (FHD) on acute alcohol toxicity in mice. METHOD: Acute alcohol toxicity in mice was used to observe the effects of FHD on sleep time and alcohol concentration in blood. RESULTS: FHD could shorten sleep time distinctly and reduce alcohol concentration in blood of acute alcohol toxicity mice. CONCLUSION: FHD has an obvious effect on acute alcohol toxicity.

Alcoholic Intoxication↗
PubMed2001

[Structure and function of pancreatic microcirculation].

To gain an insight into the relationship between structure and function in pancreatic microcirculation, observations were carried out in 9 corpse, 30 monkeys, 24 dogs, 62 Wistar rats and 24 rabbits by the use of scanning electron microscopy and light microscopy with the technique of retaining microcirculatory dynamic and tissular information in the static specimens, and/or by intravital fluorescence microscopy with FITC-labeled erythrocytes. The results showed: there were two capillary beds destined for the endocrine and exocrine parts of pancreas between the intralobular arteriole and venule; the blood of pancreatic portal circulation flowed from the endocrine to the exocrine part; each pancreatic lobule was supplied by a single centrally located intralobular artery and there was no anastomosis between the intralobular arterioles or any of their branches, so they were end arteries; the physiological blood flow was about 1.18 +/- 0.05 nl/min per capillary with stable capillary perfusion pattern; a profound decreased functional capillary density and capillary perfusion was observed in the early phase of acute pancreatitis. These results suggest that pancreatic lobule is a structured and functional basic unit of pancreatic microcirculation, insulo-acinar portal circulation represents the basic feature of the pancreatic microcirculation, and the intralobular arteriole, being an end artery, forms the anatomical basis of the pancreatic microcirculatory disturbance during acute pancreatitis.

Adult↗
PubMed2001

[Quality of aquatic environment at Haihe River and the pollutant fluxes flowing into sea].

On the basis of the data of water quality monitored from 1993 to 1997, the pollution indexes of each pollutant was computed. The results showed that the pollution at Haihe river was severe. The rank of water quality at all monitoring site were between IV and V grade. The main pollution factors were NH3-N, NO2-N and organic contaminants. During the 5 years, water quality of Haihe River was improved, however, the pollutant fluxes flowing into Bohai Bay, especially CODMn, BOD, NH3-N, NO3-N and NO2-N, were increased, they were increased from 1555, 655, 337, 156 and 25 t.a-1 in 1993 to 8710, 4317, 2516, 1528 and 188 t.a-1 in 1996, and sharply decreased to 1331, 973, 572, 355 and 31 t.a-1 in 1997, respectively. It may be mainly due to the change of runoff at Haihe River.

Fresh Water↗
PubMed2001

Application of inferior major bone flap craniotomy decompression in brain injury.

OBJECTIVE: To summarize the application of inferior major bone flap craniotomy decompression in brain injury operation. METHODS: A retrospective analysis was done in 218 cases with brain injuries who were admitted to our department from January 1995 to December 1999 and treated with the inferior major bone flap craniotomy decompression. RESULTS: Of 218 cases, 121 cases (55.50%) were cured according to GOS, 39 (18.30%) were with good recovery or moderate disability, 13 (5.60) with severe deformity, 3 (1.40%) vegetative life, the rest 42 (19.20%) died after operation; no encephalocele or incarceration were found. CONCLUSIONS: The inferior major bone flap craniotomy decompression can remove hematoma timely and completely, is better than general craniotomy decompression and has a positive effect on brain injuries especially when bone flap is small.

Brain Injuries↗
PubMed2001

[Clinical study of a new expander with an agent delivery system and the effect of a chemical agent on tissue expansion].

OBJECTIVE: To search for a method to enhance tissue expansion. METHOD: A new type of expander with an agent delivery system was used to expand soft tissue in 15 patients. During expansion Papaverine was delivered through the delivery system into the tissue around the expanders. RESULTS: It took 26 days to expand to the anticipated volume in the new expansion method group (NEM) and 51 days in the general expansion method group (GEM) (P < 0.01). Before operation the NEM group was over-expanded by 92.4% while the GEM group was over-expanded by 27.12%. At full expansion the blood flow of the expanded area of the two groups was 1.27 (NEM) and 0.64 (GEM). The immediate skin retraction of the two groups was 20.17% (NEM) and 38.26% (GEM). CONCLUSION: The new expansion method can accelerate expansion speed and improve the quality of expanded skin and flap.

Drug Delivery Systems↗
PubMed2001

[The blood drainage of Langerhans islets with special reference to the functional and clinical significance of pancreatic exocrine part].

OBJECTIVE: This study sought to gain an insight into the blood drainage of Langerhans islets with special reference to the functional and clinical significance of pancreatic exocrine part. METHODS: Observations were carried out in 11 human dead bodies, 40 monkeys, 24 dogs, 62 rats and 24 rabbits by scanning electron microscopy and light microscopy with the technique of retaining microcirculatory dynamic and tissular information in the static specimens, microvascular serial reconstruction, and/or by intravital fluorecence microscopy with FITC-labeled erythrocytes. RESULTS: Three patterns of islet drainage channels drained into different acinar regions with different features and insulo-insular drainage channels observed in the primates were found in this study. The authors suggest that these patterns might be termed as follows: 1. Continuous drainage vessels. All islets possessed these capillary-sized portal vessels which ran a short distance, and then drained into the peri-islet acinar region. 2. Convergent drainage vessels. Some islets possessed one or two, occasionally more, of these portal vessels, which were relatively long and/or thick and drained into the acinar region far away from the islet in the lobule. 3. Translobular drainage vessels. These portal vessels crossed the interlobular septum into an adjacent lobule where sometimes no islet existed, and then drained into the exocrine acinar region 4. Insulo-insular drainage vessels. Some islets in the monkey and human, possessed these vessels which drained into an adjacent small islet through the insulo-insular drainage vessels. CONCLUSION: Langerhans islets possessed the consummate drainage system which drained into different exocrine acinar regions, suggesting that the release of islet hormones is in some way necessary for the exocrine secreting function, and that the reduction of local insular hormone levels in insuloacinar portal circulation and the impairment of insular drainage vessels would be the morphological basis of the pancreatic exocrine pathologic lesion in human diabetes.

Adult↗
PubMed2001

[The expression of growth factors in filtering area following sclerectomy and the interaction between growth factors and interferon].

OBJECTIVE: To study the expression of beta-Fibroblastic Growth Factor (bFGF) and Transforming Growth Factor beta 1 (TGF beta 1) in filtering area following sclerectomy and the interaction between growth factors and interferon alpha-2b (IFN alpha-2b). METHODS: Immunohistochemical technique were applied to test the expression bFGF and TGF beta 1 in frozen sections of filtration area following sclerectomy on postoperative day three, five, seven and 14 in white rabbits, respectively. 16 eyes of eight rabbits in all were randomly and equally divided into two groups. The experimental eyes had subconjunctivally been administered IFN alpha-2b 5 x 10(5) IU 0.2 ml each time at filtering bleb following operation whereas the control eyes hadn't taken. RESULTS: In control group, positive cell and substance expressing bFGF and TGF beta 1 on postoperative day three were revealed in the filtration area, on postoperative day five and seven, they were gradually increased. On the postoperative day 14, all significant cells and substance markly decreased. In experimental group only small amount of positive cell and bFGF or TGF beta 1-expressing substance were sparely distributed in the filtration area. CONCLUSION: The filtration area after glaucoma filtering surgery was "bathed" in growth factors such as bFGF and TGF beta 1 which well-known play an important role in stimulating wound healing response, IFN alpha-2b had an inhibitory effect on bFGF or TGF beta 1 expression in wound environment.

Animals↗
PubMed2001

[Spectroscopic studies on the binding of effective component of Chinese herbs with human serum albumin].

Tanshione II A and Cryptotanshinone are the main effective components of the traditional Chinese medicine Salvia miltiorrhiza bung. They both have many kinds of physiologic activities. When a medicine enters the body, it always goes to the acceptor site and has pharmacodynamic action by way of storage and carriage of plasma. Serum albumin is the major serum protein, which can combine with many inner and outer source compounds. In this paper, we have studied the interaction of Tanshinone with the human serum albumin(HSA) in beta-CD buffer system by spectroscopic method. The results show that the absorption maximum of Tanshinone exhibit red shift upon binding to HSA and the absorbance enhance. Tanshinone have stronger fluorescence quenching effect on HSA and the dissociation constants of Tanshinone bound to HSA are calculated. The distance of protein Trp-214 to the first binding site is also calculated on the basis of energy transfer between HSA and bound Tanshinone.

Abietanes↗
PubMed2000

Valproate prevents the induction of sensitization to methylphenidate (ritalin) in rats.

Repetitive exposure to methylphenidate (MPD) elicits sensitization to its locomotor effects. Drugs that affect the GABA system may modify adaptations to drug exposure. Therefore, we have examined the effect of sodium valproate, which enhances GABA function, on the development of sensitization to MPD using an automated, computerized animal activity monitoring system to record each rat's motor activities for 15 consecutive days. Rats were recorded before and after saline injection (Days 1-2) to provide baseline activity. Animals were then randomly assigned to the following three groups that received: (1) 2.5 mg/kg MPD (s.c.) for six consecutive days (Days 3-8), (2) a single dose of valproate (50 mg/kg; i.p.) 1 h prior to the first (Day 3) of six daily doses of MPD (2.5 mg/kg; s.c. ), or (3) five daily doses of valproate (50 mg/kg, i.p.) 1 h prior to MPD (2.5 mg/kg, s.c.) on Days 4-8. There was no drug treatment during the next 5 days (Days 9-13). All rats were then re-challenged with MPD (2.5 mg/kg, s.c.) on Day 14. Group 2 rats were also re-challenged with 50 mg/kg valproate followed by 2.5 mg/kg MPD 1 h later on Day 15. Administration of MPD alone produced a sensitized response. Multiple valproate injections prevented the induction of MPD-elicited sensitization in all four motor indices, while a single valproate injection prevented the induction of MPD-elicited sensitization in two of four motor indices studied. In conclusion, a single injection 50 mg/kg valproate given prior to any MPD treatment partially blocked the induction of MPD sensitization while repeated injections of valproate co-administered with MPD treatment completely prevented this effect.

Animals↗
PubMed2000

15-Lipoxygenase-1 mediates nonsteroidal anti-inflammatory drug-induced apoptosis independently of cyclooxygenase-2 in colon cancer cells.

We previously found (I. Shureiqi et al., Carcinogenesis (Lond.), 20: 1985-1995, 1999; I. Shureiqi et al, J. Natl. Cancer Inst., 92: 1136-1142, 2000) that (a) 15-lipoxygenase-1 (15-LOX-1) protein and its product 13-S-hydroxyoctadecadienoic acid (13-S-HODE) are decreased; and (b) nonsteroidal anti-inflammatory drug (NSAID)-induced 15-LOX-1 expression is critical to NSAID-induced apoptosis in colorectal cancer cells expressing cyclooxygenase-2 (COX-2). We used the NSAIDs sulindac sulfone (COX-2-independent) and NS-398 (a COX-2 inhibitor) to assess NSAID upregulation of 15-LOX-1 in relation to COX-2 inhibition during NSAID-induced apoptosis in the DLD-1 (COX-2-negative) colon cancer cell line. We found that: (a) NSAIDs up-regulated 15-LOX-1, which preceded apoptosis; and (b) 15-LOX-1 inhibition blocked NSAID-induced apoptosis, which was restored by 13-S-HODE but not by its parent, linoleic acid. NSAIDs can induce apoptosis in colon cancer cells via up-regulation of 15-LOX-1 in the absence of COX-2.

Anti-Inflammatory Agents, Non-Steroidal↗
PubMed2000

A simple copper(II)-L-histidine system for efficient hydrolytic cleavage of DNA.

Copper(II)-L-histidine complexes effectively promote the cleavage of plasmid DNA and dideoxynucleotide dApdA at physiological pH and temperature. Studies of the mechanism of plasmid DNA cleavage by added radical scavengers, using rigorously anaerobic experiments, analyses for malondialdehyde-like products, religation assays, and HPLC analyses, indicate that DNA cleavage mediated by Cu(L-His) occurs via a hydrolytic path. The hydrolytic cleavage rate constants at 37 degrees C are estimated to be 0.76 h-1 for the decrease of form I and 0.25 h-1 for the increase of form III. The phosphoimager picture reveals that Cu(L-His) cleaves DNA with a certain sequence specificity (preferentially at 5'-GT-3'). The dinucleotide hydrolysis shows, with [Cu(L-His)] = 0.8 mM, rate enhancement factors of > 10(8). Interestingly, histidine-metal ion interactions (with Cu(II), Ni(II), Zn(II), etc.) have been used for various applications, e.g., protein purification, cross-linking, and targeting proteins to lipid bilayers. Our findings may provide the basis for developing new applications and new ways to design more effective and useful catalysts for DNA cleavage. Cu(L-His) is one of only a few well-defined metal complexes demonstrated to hydrolytically cleave dideoxynucleotides and DNA.

Animals↗
PubMed2000

Adeno-associated virus production of soluble tumor necrosis factor receptor neutralizes tumor necrosis factor alpha and reduces arthritis.

The major limitation of adenovirus is its association with induction of an inflammatory response and relatively short-term production of the gene therapy transgene product. Adeno-associated virus (AAV) is a 4.68-kb single-strand DNA virus that contains ITRs for viral replication and a packaging signal, and also has been engineered to contain therapeutic genes up to 5 kb in length. Transduction of recombinant AAV (rAAV) results in low inflammatory response and long-term expression. We have cloned a low-immunogenic form of human sTNFRI (sTNFRI2.6D) into AAV (rAAVsTNFRI). This vector was analyzed for its ability to transfect and neutralize the effect of TNF-alpha on primary rheumatoid arthritis synovial fibroblast (RASFs). The rAAVsTNFRI was transduced into the cells at 1.8 x 10(1), 1.8 x 10(2), and 1.8 x 10(3) viral particles per cell. There was greater than 90% neutralization of TNF-alpha at 1.8 x 10(3) viral particles/cell. There was a significant decrease in the synovial cell hyperplasia and cartilage and bone destruction in human TNF-alpha transgenic mice treated intraarticularly with rAAVsTNFRI. These results indicate that the low-immunogenic and long-term expressing vector, rAAVsTNFRI, can be used to deliver the soluble TNF-alpha in vitro and in vivo and effectively reduce the severity of arthritis.

Animals↗