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Biomedical subjects

Z Liao

Publications and source records attributed to Z Liao.

At least 19 recordsLinked to original sources
PubMed2006

Gender-based analysis of esophageal cancer patients undergoing preoperative chemoradiation: differences in presentation and therapy outcome.

The purpose of this study was to identify gender-dependent differences in presentation at baseline and therapy outcome in esophageal carcinoma patients treated with preoperative chemoradiotherapy (CTRT). We stratified patients according to gender and statistically compared pretreatment clinical stage, post-CTRT effect on carcinoma in the resected specimen, overall survival (OS), and patterns of failure. Of the 235 patients who underwent preoperative CTRT, 203 were men and 32 were women. Carcinomas in women correlated significantly with clinical stage II classification (78%vs. 55%) while cancers in men correlated significantly with clinical stage III classification (39%vs. 16%; P = 0.02). Carcinomas in women also correlated significantly with lower clinical N classification; more women had cN0 (52%) compared to men (28%; P = 0.01). Similarly, in the surgical specimens, more women had pN0 (78%) compared to men (64%; P = 0.06). At a median follow-up of 37 months, 10% more women than men remain alive (63%vs. 53%; P = 0.3). Distant metastases-free survival time was longer for women than men. Our results suggest that localized esophageal carcinoma is diagnosed in more advanced stages in men than in women. The reasons for these differences remain unclear and further expansion of these observations and study of biologic differences that might exist are warranted.

Chemotherapy, Adjuvant↗
PubMed2005

PAN-811 (3-aminopyridine-2-carboxaldehyde thiosemicarbazone), a novel neuroprotectant, elicits its function in primary neuronal cultures by up-regulating Bcl-2 expression.

Neurotoxicity in primary neurons was induced using hypoxia/hypoglycemia (H/H), veratridine (10microM), staurosporine (1microM) or glutamate (100microM), which resulted in 72%, 67%, 75% and 66% neuronal injury, respectively. 3-Aminopyridine-2-carboxaldehyde thiosemicarbazone (PAN-811; 10microM; Panacea Pharmaceuticals, Gaithersburg, MD) pretreatment for 24 h provided maximal neuroprotection of 89%, 42%, 47% and 89% against these toxicities, respectively. Glutamate or H/H treatment of cells increased cytosolic cytochrome c levels, which was blocked by pretreatment of cells with PAN-811. Pretreatment of neurons with PAN-811 produced a time-dependent increase in the protein level of Bcl-2, which was evident even after glutamate or H/H treatments. An up-regulation in the expression of the p53 and Bax genes was also observed following exposure to these neurotoxic insults; however, this increase was not suppressed by PAN-811 pretreatment. Functional inhibition of Bcl-2 by HA14-1 reduced the neuroprotective efficacy of PAN-811. PAN-811 treatment also abolished glutamate or H/H-mediated internucleosomal DNA fragmentation.

Animals↗
PubMed2005

Optimization of Suzhou Creek Rehabilitation Project Stage I.

Suzhou Creek is a seriously polluted tidal river in Shanghai, China. With the development of Shanghai, there is more and more concern over the "blackness and stink" phenomenon of Suzhou Creek. Suzhou Creek Rehabilitation Project was launched in 1998, and the planning investment of the Project Stage I was 8.65 billion yuan (about 1.05 billion US dollars). It is important to predict the effectiveness of the project and to optimize it. In this study, the USEPA's WASP model is employed to establish a water quality model of Suzhou Creek by using data from the Third Trial Low Flow Augmentation on Suzhou Creek in 1999 and other monitoring results. Based on this, Suzhou Creek Rehabilitation Project Stage I is optimized and adjusted, so the actual investment of the Project Stage I is reduced to 6.99 billion yuan. By implementing the Project Stage I, the targets of Stage I have been met, the "blackness and stink" phenomenon of the mainstream was eliminated by the end of 2000, and the ecological system was improved step by step.

China↗
PubMed2004

A modified equivalent annulus model for the hollow fiber hemodialyzer.

Experimental approaches to optimize hollow fiber hemodialyzer design are expensive and time-consuming. Computer modeling is an effective way to study mass transfer in the hemodialyzer because a substantial reduction in experimental time and cost can be achieved. This paper presents a two-dimensional modified "equivalent annulus" model, which employs Navier-Stokes (N-S) equations to describe blood and dialysate flow, and Kedem-Katchalsky (K-K) equations to calculate transmembrane flow. N-S equations and K-K equations must be coupled together in the process of computing. The corresponding experiments were designed to validate this model, and experimental results agreed well with numerical results. The distribution of velocity, pressure and solute concentration were investigated in detail, presenting a clear insight into dialyzer mass transfer. This model can be applied to help optimize hemodialyzer design.

Algorithms↗
PubMed2003

A high-rate secondary treatment based on a moving bed bioreactor and multimedia filters for small wastewater treatment plants.

For small wastewater treatment plants (WWPTs), high-rate secondary treatment systems with good treatment efficiency and easy, stable, and robust operation are called for. In this paper an experimental study on a high rate secondary treatment based on moving bed biofilm reactor (MBBR) and multimedia filters is presented. A high rate MBBR converts easily biodegradable SCOD in short HRT (0.5 h) directly after screening, then a Kaldnes-Filtralite-Sand (KFS) filter removes the particulate COD and detached biofilms at filtration rates of 10-20 m/h. The whole system gave effluent SS and COD less than 30 mg/L and 100 mg/L when total detention time is less than 1 h and small dosage of chemicals (iron and/or cationic polymer) is used. A new scenario of high rate secondary system with a primary Kaldnes coarse media filter in front of high rate MBBR and the KFS filter is proposed and discussed. This scenario with total HRT less than 2h is more suitable for high influent SS concentrations and may also be extended for nitrogen and phosphorous removal. Compared to conventional secondary treatment, the high rate secondary treatment will be using only 1/5-1/10 of the space, resulting in considerable savings for construction, energy and operation.

Biofilms↗
PubMed2003

Coarse media filtration--an alternative to settling in wastewater treatment.

In this paper coarse media filtration has been analysed as an alternative to the traditional settling in primary, secondary and tertiary treatment of wastewater. Various filter media configurations were evaluated for enhanced primary filtration. It was found that a dual media configuration based on Kaldnes biofilm media (1 and K2modified) were most suitable when taking both separation efficiency as well as filter run time into consideration. SS removal efficiencies of around 75% were achieved in the dual Kaldnes primary filter at around 20 m/h without any chemical addition and around 85% at low dosage (1-2 mg/l) of a high MW cationic polymer FO4440SH. In the latter case COD was removed by around 70%. Further experiments were carried out on a multi-media Kaldnes-Filtralite-Sand (KFS) filter for enhanced primary treatment as well as for secondary filtration directly downstream of a high-rate moving bed biofilm reactor, resulting in an extremely compact secondary treatment process. The secondary KFS-filter gave SS-removal efficiencies around 90% (effluent SS < 15 mg/l) and filter run times of around 24 hrs at filtration rates of 10 m/h (sludge loading rates of around 1 kg/m2h) when a small dose (2 mg/l) of polymer was used. It is also demonstrated that the primary filter may also be utilised as a pre-denitrification reactor. A denitrification rate of 1.5 kg NO3-N(equiv.)/m3d was achieved when the filter was operated at a filtration rate of 5 m/h.

Carbon↗
PubMed2002

Randomized phase III study of chemoradiation with or without amifostine for patients with favorable performance status inoperable stage II-III non-small cell lung cancer: preliminary results.

A prospective randomized study was conducted to determine whether amifostine (Ethyol) reduces the rate of severe esophagitis and hematologic and pulmonary toxicity associated with chemoradiation or improves control of non-small cell lung cancer (NSCLC). Sixty patients with inoperable stage II or III NSCLC were treated with concurrent chemoradiotherapy. Both groups received thoracic radiation therapy (TRT) with 1.2 Gy/fraction, 2 fraction per day, 5 days per week for a total dose 69.6 Gy. All patients received oral etoposide (VP-16), 50 mg Bid, 30 minutes before TRT beginning day 1 for 10 days, repeated on day 29, and cisplatin 50 mg/m(2) intravenously on days 1, 8, 29, and 36. Patients in the study group received amifostine, 500 mg intravenously, twice weekly before chemoradiation (arm 1); patients in the control group received chemoradiation without amifostine (arm 2). Patient and tumor characteristics were distributed equally in both groups. Of the 60 patients enrolled, 53 were evaluable (27 in arm 1, 26 in arm 2) with a median follow-up of 6 months. Median survival times were 26 months for arm 1 and 15 months for arm 2, not statistically significantly different. Morphine intake to reduce severe esophagitis was significantly lower in arm 1 (2 of 27, 7.4%) than arm 2 (8 of 26, 31%; P =.03). Acute pneumonitis was significantly lower in arm 1 (1 of 27, 3.7%) than in arm 2 (6 of 26, 23%; P =.037). Hypotension (20 mm Hg decrease from baseline blood pressure) was significantly more frequent in arm 1 (19 of 27, 70%) than arm 2 (1 of 26, 3.8%; P =.0001). Only 1 patient discontinued treatment because of hypotension. These preliminary results showed that amifostine significantly reduced acute severe esophagitis and pneumonitis. Further observation is required to assess long-term efficacy.

Adult↗
PubMed2002

Coarse media filtration for enhanced primary treatment of municipal wastewater.

In these experimental studies enhanced primary treatment in coarse media filters has been evaluated. The coarse media used in the filters have been plastic carriers normally used for moving bed bioreactors, a Kaldnes carrier K1 with density < 1 g/cm3 (K1L) and a bigger carrier K2, that was used both in a lighter, floating (K2L) version and a heavier, sinking one (K2H). The results demonstrated that media characteristics significantly influenced filter performance. The dosing of a high MW and high charge cationic polymer was, however, found to have an even greater effect on treatment efficiency and especially on head loss development. Both filters were found to be feasible for enhanced primary treatment at high filtration rates (20-30 m/h) especially when dosing low dosages (1-3 mg/l) of polymer. The combination of two media into a dual media filter might take the advantages of both. Further experiments were carried out on a dual media filter consisting of lighter K1L media and heavier K2H media. It was indeed found that the K1L+K2H up-flow filter resulted in better performances in terms of water production when an optimised backwash procedure was taken into account.

Bioreactors↗
PubMed2001

Respiratory-driven lung tumor motion is independent of tumor size, tumor location, and pulmonary function.

PURPOSE: To determine whether superior-inferior lung tumor motion is predictable by tumor size or location, or pulmonary function test results. METHODS AND MATERIALS: Superior-inferior tumor motion was measured on orthogonal radiographs taken during simulation of 22 patients with inoperable lung cancer diagnosed by orthogonal radiographs. RESULTS: The tumor size averaged 5.5 +/- 3.1 cm (range 1.5-12 cm). Seven of 11 central tumors demonstrated some motion compared with 5 of 11 peripheral tumors. Four of 5 upper lobe tumors moved compared with 8 of 17 tumors that were either middle or lower lobe lesions. The mean fourth rib motion was 7.3 +/- 3.2 mm (range 2-15). The mean FeV(1) was 1.8 +/- 1.2 (range 0.55-5.33. The mean diffusing capacity of the lung for carbon monoxide was 14.0 +/- 6.5 (range 7.8-21.9). The mean total lung capacity was 6.5 +/- 1.2 (range 3.3-8.4). None of these parameters correlated with tumor motion. Although lateral tumor motion could not be consistently determined, 1 tumor moved 10 mm anterior-posteriorly. CONCLUSIONS: Lung tumors often move significantly during respiration. Tumor motion is not predictable by tumor size or location, or pulmonary function test results. Therefore, tumor motion must be measured in all patients. Measurement in three dimensions will likely be necessary to maximize the irradiated lung volumes or choose beam arrangements parallel to the major axis of motion.

Adult↗
PubMed2001

Cardiotrophin-1 can protect cardiac myocytes from injury when added both prior to simulated ischaemia and at reoxygenation.

OBJECTIVE: The cytokine cardiotrophin-1 (CT-1) has previously been shown to protect cultured cardiocytes from cell death induced by serum removal or hypoxia when administered prior to the damaging stimulus. We wished to test whether a similar protective effect could be observed if CT-1 was added after the ischaemic period and to investigate the signalling pathways involved in the protective effect when CT-1 is given prior to or after ischaemia. METHODS: We therefore examined the protective effect of CT-1 in cultured rat cardiocytes exposed to simulated ischaemia followed by reoxygenation when CT-1 was administered either prior to simulated ischaemia or at reoxygenation. RESULTS: We show that CT-1 can exert a protective effect against the damaging effects of simulated ischaemia/reoxygenation both when added after the simulated ischaemia at reoxygenation (P<0.05 in trypan blue, TUNEL and annexin V assays) or when added prior to the simulated ischaemia (P<0.05). In both cases, these protective effects are blocked by an inhibitor of the p42/p44 MAPK pathway (P<0.05 in all assays). CONCLUSION: CT-1 can protect cardiac cells when added either prior to simulated ischaemia or at the time of reoxygenation following simulated ischaemia and these effects are dependent upon its ability to activate the p42/p44 MAPK pathway. Hence CT-1 may have therapeutic potential when added at the time of reperfusion following ischaemic damage.

Animals↗
PubMed2001

Lipid rafts and HIV pathogenesis: host membrane cholesterol is required for infection by HIV type 1.

In a previous study we showed that budding of HIV-1 particles occurs at highly specialized membrane microdomains known as lipid rafts. These microdomains are characterized by a distinct lipid composition that includes high concentrations of cholesterol, sphingolipids, and glycolipids. Since cholesterol is known to play a key role in the entry of some other viruses, our observation of HIV budding from lipid rafts led us to investigate the role in HIV-1 entry of cholesterol and lipid rafts in the plasma membrane of susceptible cells. We have used 2-OH-propyl-beta-cyclodextrin (beta-cyclodextrin) to deplete cellular cholesterol and disperse lipid rafts. Our results show that removal of cellular cholesterol rendered primary cells and cell lines highly resistant to HIV-1-mediated syncytium formation and to infection by both CXCR4- and CCR5-specific viruses. beta-Cyclodextrin treatment of cells partially reduced HIV-1 binding, while rendering chemokine receptors highly sensitive to antibody-mediated internalization. There was no effect on CD4 expression. All of the above-described effects were readily reversed by incubating cholesterol-depleted cells with low concentrations of cholesterol-loaded beta-cyclodextrin to restore cholesterol levels. Cholesterol depletion made cells resistant to SDF-1-induced binding to ICAM-1 through LFA-1. Since LFA-1 contributes significantly to cell binding by HIV-1, this latter effect may have contributed to the observed reduction in HIV-1 binding to cells after treatment with beta-cyclodextrin. Our results indicate that cholesterol may be critical to the HIV-1 coreceptor function of chemokine receptors and is required for infection of cells by HIV-1.

Cell Line↗
PubMed2001

Mantle irradiation alone for pathologic stage I and II Hodgkin's disease: long-term follow-up and patterns of failure.

PURPOSE: We performed a retrospective study to determine the long-term outcome, patterns of failure, and prognostic factors for patients with pathologic Stage I or II Hodgkin's disease (HD) who were treated with mantle irradiation alone. METHODS AND MATERIALS: The medical records of 145 patients with pathologic Stage I or II supradiaphragmatic Hodgkin's disease treated with mantle irradiation alone between June 1967 and June 1991 were reviewed. Patterns of failure, overall survival (OS) rate, and progression-free survival (PFS) rate were determined. Univariate and multivariate analyses were performed to identify adverse prognostic factors for OS and PFS. The number of adverse prognostic factors per patient was counted, and a prognostic score was assigned to each patient. The log-rank test was used to compare the OS or PFS rates among patients with prognostic scores 0, 1, and 2. RESULTS: The median patient age was 27 years (range 10-66), with almost even male to female distribution. Every patient had splenectomy and negative laparotomy (LAP). Fifty-one patients had Stage I disease (IA-49, IB-2) and 94 Stage II (IIA-89, IIB-5). The histologic subtypes were nodular sclerosing in 110, mixed cellularity in 28, lymphocyte predominance in 5, lymphocyte depleted in 1, and unclassified in 1. Twelve patients with Stage II disease had >/= 3 sites of nodal involvement. Fifty-four patients had a prognostic score of 0, 70 of 1, and 21 of 2. The median follow-up time for the 109 surviving patients was 146 months (range 25-381). The 10- and 20-year actuarial OS rates for the whole group were 87.6% and 65.3%, respectively. The corresponding actuarial PFS rates were 75.3% and 74.2%, respectively. Thirty-six patients (9 Stage I, 27 Stage II) had relapses in a total of 41 sites. Failures by histology were 29 patients with nodular sclerosing, 6 with mixed cellularity, and 1 with lymphocyte predominance. Failures by sites were: trans-diaphragmatic, 22 (para-aortic nodes, 15; as the only site of progression in 12; visceral, 7; as the only site of progression in 5); within radiation field, 8; marginal miss, 8 (as the only site of failure in 2); and unknown, 3. The majority of the failures occurred within 5 years of diagnosis. Long-term side effects of radiation included cardiac complications in 30 patients, with 10- and 20-year actuarial cardiac complication rates of 12.6% and 35.1%, respectively; secondary solid tumors in 14, with 10- and 20-year actuarial rates of 2.3% and 25.7%, respectively; leukemia in 4; non- Hodgkin's lymphoma in 4, with the 10- and 20-year actuarial rates for leukemia and non-Hodgkin's lymphoma of 4.0% and 13.9%; and hypothyroidism in 38. Four adverse prognostic factors were identified for PFS: age > or = 40 years, > or = 3 sites of involvement, male sex, and constitutional symptoms. The prognostic score correlated with patients' outcome as indicated by PFS and OS rates. Patients with a prognostic score of 0 did significantly better than those with a score of 1 or 2. CONCLUSION: In this select group of patients with pathologic Stage I and II Hodgkin's disease treated with mantle irradiation alone, the OS and PFS rates at 10 and 20 years were comparable to those reported in the literature. The major pattern of disease progression was relapse below the diaphragm, therefore close surveillance of the abdomen is warranted. The prognostic score used in our series may predict the patient's outcome, and might be worth testing in a prospective trial. In our series, patients with a prognostic score of 0 had excellent long-term survival, indicating adequate treatment with mantle irradiation alone. Late complications of the treatment pose a significant threat for the patient's survival with long-term follow-up.

Adolescent↗
PubMed2001

Functional gamma-secretase inhibitors reduce beta-amyloid peptide levels in brain.

Converging lines of evidence implicate the beta-amyloid peptide (Ass) as causative in Alzheimer's disease. We describe a novel class of compounds that reduce A beta production by functionally inhibiting gamma-secretase, the activity responsible for the carboxy-terminal cleavage required for A beta production. These molecules are active in both 293 HEK cells and neuronal cultures, and exert their effect upon A beta production without affecting protein secretion, most notably in the secreted forms of the amyloid precursor protein (APP). Oral administration of one of these compounds, N-[N-(3,5-difluorophenacetyl)-L-alanyl]-S-phenylglycine t-butyl ester, to mice transgenic for human APP(V717F) reduces brain levels of Ass in a dose-dependent manner within 3 h. These studies represent the first demonstration of a reduction of brain A beta in vivo. Development of such novel functional gamma-secretase inhibitors will enable a clinical examination of the A beta hypothesis that Ass peptide drives the neuropathology observed in Alzheimer's disease.

Administration, Oral↗
PubMed2001

[The dynamic changes of serum TNFalpha level in scalded rats after the administration of rhGH during the early postburn stage].

OBJECTIVE: To examine the dynamic change of serum TNFalpha level in scalded rats after the administration of rhGH during the early postburn stage. METHODS: Forty-two male sanitary Sprague-Dawley rats were randomly divided into three groups, i.e. normal control (N), burn with early administration of rhGH (BA) and burn without rhGH (BN) groups. The rats were inflicted with 25% similar 30% TBSA deep partial thickness scalding on the back. rhGH in dose of 6 U/kg was administered subcutaneously via abdominal skin starting from the 1st postburn day (PBD). Rat serum TNFalpha levels were determined by ELISA in BA and BN groups at 3, 6 and 10 PBDs. RESULTS: The rat serum TNFalpha level in BA was lower than that in BN groups on 3 PBD. Whilst the TNFalpha levels in BA were much higher than those in BN groups on 6 and 10 PBDs. CONCLUSION: Administration of rhGH at early postburn stage might abate the early systemic postburn reaction.

Animals↗
PubMed2001

[Study on determination of trace cadmium in Chinese medicine loulu by graphite furnace atomic absorption spectrometry].

A method for the determination of trace cadmium in chinese medicine Loulu by graphite furnace atomic absorption spectrometry (GFAAS) has been described. The matrix modifier and its proper concentration, the influence factors including ashing and atomization temperature, atomization time and coexisting ions were investigated. Under the optimum experimental conditions, the detection limit and the relative standard deviation of the method were 0.06 ng.mL-1 and 2.43% (n = 11), respectively. The recovery was between 97% and 105%. The method is simple, rapid and accurate, and can eliminate the matrix effect. It has been applied to the direct determination of trace cadmium in chinese medicine Loulu with satisfactory results.

Cadmium↗
PubMed2001

[The effect of perindopril in treatment of early diabetic nephropathy with normal blood pressure and microalbuminuria].

OBJECTIVE: To study the effect of perindopril in decreasing the urinary albumin excretion rate (AER) and protecting the renal function in normotensive early diabetic nephropathy. METHODS: 52 diabetic patients with AER between 20 to 200 microg/min, were treated with dietary regimen, oral antihyperglycemic agents or/ and insulin till their fasting blood glucose (FBG) was < 7.0 mmol/L and postprandial blood glucose (PBG) < 10.0 mmol/L. They were then divided randomly into two groups. Group A was a control group (25 cases), the patients were administered with placebo, group B was a treatment group (27 cases), the patients were administered with perindopril (4 mg/day) FBG, PBG, glycosylated haemoglobin A1c (HbA1c), AER, blood pressure (MAP) and blood creatinine (Cr) were examined immediately and 3, 6, 12 and 18 months after the treatment. RESULTS: In group A, AER was significantly increased after 12 and 18 months than at beginning, they were (52.3 +/- 8.6) microg/min and (60.4 +/- 9.0) microg/min vs (44.2 +/- 6.8) microg/min (P < 0.05). In group B, after being treated with perindopril, AER estimated 3, 6, 12 and 18 months later were (20.3 +/- 5.6) microg/min, (22.1 +/- 6.1) microg/min, (21.3 +/- 5.9) microg/min and (20.8 +/- 5.7) microg/min respectively, all were significantly lower those that of group A in the same period (P < 0.05) and also significantly lower than those at the beginning (P < 0.05). CONCLUSION: Perindopril has good effects in decreasing AER in normotensive early diabetic nephropathy and in protecting the renal function.

Adult↗