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In this paper, the problem we investigate is that the inverse problem of identifying the initial value for fractional pseudo-parabolic equation. This problem is ill-posed, i.e. the solution (if exists) does not depend on the measurable data. We give the estimate of conditional stability under an a-priori bound assumption for exact solution. Two regularization methods are used to solve this problem, and under an a-priori and an a-posteriori selection rule for the regularization parameter, the error estimates for these methods are obtained. Finally, several numerical examples are given to prove the effectiveness of these regularization methods. [ABSTRACT FROM AUTHOR]

The lithology and genesis of a dark grey clastic interlayer first encountered within the deepest potassium-rich salt body in the Simao Basin, southwestern China, were analysed. Analyses of the petrography, mineralogy, and element geochemistry of the layer revealed that (1) the layer contains quartz crystals with gulf corrosion edges and explosion cracks and angular volcanic ash-sized glasses; (2) the main mineral components of the crystal fragments are chlorite, illite, biotite, quartz, anhydrite, gypsum, magnesite, pyrite, molybdenite, clinopyroxene, and zircon; (3) the rare earth element patterns, Zr/TiO2 and Nb/Y diagrams as well as boron content all indicate a volcanic origin for the layer. Based on these observations, the layer is suggested to be an altered tuff associated with various volcanic fragments dominated by chlorite and formed after alteration of a parent tuff in an alkaline, salty, and low-temperature water body. Discovery of the layer indicates that the potash-bearing salt rocks could have taken in volcanic materials during these volcanic activities and provides the possibility of reliable zircon U‒Pb dating to determine the absolute age of the host rock, which is fundamental in studying the genetic mechanism of this deeply buried salt body. [ABSTRACT FROM AUTHOR]

The presence of negative air ions (NAI) is suggested to be a beneficial factor in improving psychological status and used in treating depression as an alternative approach. However, more biological evidence from animal models is needed to ensure the effects of NAI on the mood regulation, through which can facilitate identification of possible underlying mechanisms. In this study, the chronic mild stress (CMS) protocol was used to induce depressive-like behaviors in mice, and the effects of NAI exposure on CMS-induced depression-like behaviors were examined. Thirty-day NAI exposure prevented the CMS-induced depression-like behaviors as shown by the restoration of sucrose preference and reduced immobility time in the tail suspension test. In addition, the elevation of serous corticosterone was present in CMS-treated mice but not existed in those with the NAI exposure. Furthermore, we observed altered ratios of some cytokines secreted by type 1 T helper (Th1) cells and Th2 cells in CMS-treated mice, but it could be restored after NAI exposure. In conclusion, NAI intervention is able to ameliorate CMS-induced depression-like behaviors in mice, and this effect is associated with the alteration of corticosterone and functional rebalance between Th1 and Th2 cells. [ABSTRACT FROM AUTHOR]

Background and aims: Rifaximin has been recommended as a prophylactic drug for hepatic encephalopathy (HE) and spontaneous bacterial peritonitis (SBP). This study aims to explore whether low-dose rifaximin can prevent overall complications and prolong survival in cirrhotic patients. Methods: In this multi-centre randomized open-labelled prospective study, 200 patients with decompensated cirrhosis were randomly assigned at a ratio of 1:1. Patients in rifaximin group were administered 400 mg rifaximin twice daily for 6 months, and all other therapeutic strategies were kept unchanged in both groups as long as possible. The primary efficacy endpoints were the incidence of overall complications and liver transplantation-free survival. The secondary endspoints were the incidence of each major cirrhosis-related complication, as well as the Child–Pugh score and class. Results: The major baseline characteristics were similar in the two groups except for HE. The cumulative incidence and frequency of overall complications were significantly lower in rifaximin group than in the control group (p < 0.001). Though liver transplantation-free survival was not significantly different between the two groups, subgroup analysis showed rifaximin markedly prolonged liver transplantation-free survival in patients with Child–Pugh score ≥ 9 (p = 0.007). Moreover, rifaximin markedly reduced the episodes of ascites exacerbation (p < 0.001), HE (p < 0.001) and gastric variceal bleeding (EGVB, p = 0.031). The incidence of adverse events was similar in the two groups. Conclusion: Low-dose rifaximin significantly decreases the occurrence of overall complications, leading to prolonged survival in patients with advanced stages of cirrhosis in this trail. Further study should be carried out to compare the effect of this low-dose rifaximin with normal dose (1200 mg/day) rifaximin in preventing cirrhosis-related complications. Clinical trial number: NCT02190357 [ABSTRACT FROM AUTHOR]

An observer-based fault-tolerant control method is proposed for a linear system with sensor saturation constraint. Considering the linear system with simultaneous actuator faults and sensor faults, the sensor saturation would bring the output measurement error of the system, which would result in the estimation performance degradation. Firstly, the intermediate estimator is modified to estimate the system states and fault signals at the simultaneous time, and the fault-tolerant controller is designed based on the estimation to compensate the effect of actuator faults effectively. Through Lyapunov stability analysis, the sufficient conditions are obtained to ensure the states of closed-loop system to be uniformly ultimately bounded. The effect of sensor saturation error can be suppressed by adjusting some specified parameters directly without introducing any performance index. Finally, the effectiveness and superiority of the proposed method are verified by a simulation example. [ABSTRACT FROM AUTHOR]

Based on the production of a carbon nanotube (CNT) assembly, a new technique is developed for preparing CNT/epoxy (EP) composite films with high tensile strength and electrical conductivity. CNTs are synthesized by floating catalyst spray pyrolysis. After self-assembling into a hollow cylindrical assembly, CNTs are drawn and wound on a rotating drum to form a uniform CNT film. EP resin solutions of different concentrations are used to fill into the pores within the film under different pressures and form composite films after hot-press curing. The permeability of the EP resin and thus the interfacial bonding between the CNT and the EP resin are studied by varying the concentration of the EP resin solution and the pressure used for impregnation. Under optimal preparation conditions, the composite film contains CNTs of a high content of 59 wt.%, and shows a high tensile strength of 1.4 GPa and a high electrical conductivity of 1.4×105 S·m−1, 159% and 309% higher than those of the neat CNT film, respectively. [ABSTRACT FROM AUTHOR]

Introduction: Sunitinib is approved in China for treatment of gastrointestinal stromal tumors (GIST), after disease progression on, or intolerance to, imatinib. However, available data from prospective clinical trials on its efficacy and safety in Chinese patients is limited. Our objective is to determine the efficacy and safety of sunitinib in Chinese patients with imatinib-resistant/intolerant GIST. Methods: An open-label, single-arm, multicenter, phase IV study was performed in Chinese patients with imatinib-resistant/intolerant GIST. Sunitinib was administered orally in 6-week cycles of 4 weeks on-treatment (50 mg once daily) and 2 weeks off-treatment. The primary endpoint was progression-free survival (PFS). Tumors were assessed every 6 weeks for the first 24 weeks and every 12 weeks thereafter. Responses were evaluated according to Response Evaluation Criteria in Solid Tumors (RECIST) version 1.0. Results: A total of 60 patients were enrolled, of whom 59 were treated with sunitinib. All patients were Asian, and mean age was 55.1 years. Median PFS was 46.4 weeks (95% CI 33.6-53.1). An objective response (complete or partial) was observed in 11/58 (19%) patients. Median overall survival was 111.3 weeks (95% CI 75.4-167.1), median time to tumor progression was 47.3 weeks (95% CI 34.1-59.3), and median time to tumor response was 22.6 weeks (95% CI 10.4-57.3). The most common adverse events included leukopenia, fatigue, hand-foot syndrome, and neutropenia. No new safety concerns were identified. Conclusions: This study confirms that sunitinib is active and well tolerated in Chinese patients with imatinib-resistant/intolerant GIST. ClinicalTrials.gov identifier: NCT00793871. Funding: Pfizer Inc, USA. [ABSTRACT FROM AUTHOR]

The influences of applied magnetic field on the corrosion behavior of Al-3.0 wt%Mg alloy in 3.5 wt% NaCl solution were investigated by electrochemical measurements, scanning electron microscopy (SEM) and energy-dispersive spectroscopy (EDS). Stochastic analysis was applied to investigate the influences of applied magnetic field. The results indicate that the application of horizontal magnetic field of 0.4 T would increase the pitting corrosion potential ( E ), decrease the corrosion current density ( i ), prolong the pit initiation time, slow down the pit generation rate and inhibit the growth of pitting of the tested alloys in 3.5 wt% NaCl solution. The applied magnetic field would also change the mechanism of pit initiation of Al-3.0 wt%Mg alloy from A model (without magnetic field) to A + A model (with magnetic field). The intermediate product Al is the paramagnetic ion that would be influenced by magnetic field sensitively. [ABSTRACT FROM AUTHOR]

Background and Aim: Previous studies have revealed significantly increased levels of plasma and mucosal homocysteine (Hcy) in patients with Crohn's disease (CD); however, whether Hcy is involved in intestinal fibrosis of CD remains unclear. This study aimed to investigate the effects of Hcy on intestinal fibrosis in TNBS/ethanol-induced colitis and to elucidate its potential mechanisms. Methods: Sprague-Dawley rats were divided into 4 groups: normal control, normal + Hcy injection, TNBS model and TNBS model + Hcy injection. Hyperhomocysteinemia was induced by subcutaneous injection of Hcy. DAI, CMDI and HI were calculated to evaluate the severity of colitis. Masson trichrome staining was performed to assess the severity of fibrosis. The plasma and mucosal levels of Hcy were measured by HPLC-FD. The levels of IL-1β, IL-6, TNF-α, TGF-β1, CTGF, MMP-2,9 and collagen I, III in the colon were determined by ELISA, and the mRNA expressions of TGF-β1, MMP-2,9 and TIMP-1 were detected by RT-PCR. Results: Hcy was found to increase the scores of DAI, CMDI and HI; levels of IL-1β, Il-6, TNF-α, TGF-β1, CTGF, MMP-2,9 and collagen I, III; and mRNA expressions of TGF-β1, MMP-2,9 and TIMP-1 in colonic tissue of rats with TNBS/ethanol-induced colitis. Conclusions: Hcy promotes intestinal fibrosis in rats with TNBS/ethanol-induced colitis, the underlying mechanisms of which may be attributed to its effects of increasing inflammatory damage, promoting the expression of profibrogenic cytokines and influencing MMPs/TIMPs balance. [ABSTRACT FROM AUTHOR]

We present an adaptive translation confidence estimation method to predict the human-targeted translation error rate for a document-specific machine translation model. We show the effectiveness of our method that uses features derived from the internal translation decoding process and from the source sentence analysis, in both classification and regression estimate of MT quality. By dynamically training the confidence model for the document-specific MT model, we are able to achieve consistency and prediction quality across multiple documents, demonstrated by the higher correlation coefficient and F scores in finding good sentences. Furthermore, the proposed method is applied to an English-Japanese MT post-editing field study. A strong correlation between our prediction and human selection is observed with a 10 % increase in the productivity of human translators. [ABSTRACT FROM AUTHOR]

Objectives: Acute pancreatitis is one of the most common complications of endoscopic retrograde cholangiopancreatography (ERCP). Numerous studies have shown that administered nonsteroidal anti-inflammatory drugs (NSAIDs) may reduce the incidence of acute pancreatitis after ERCP. Little is known, however, about the mechanism of NSAIDs in preventing pancreatitis (PEP). Methods: In this study, we assigned patients to receive a single dose of intramuscular diclofenac 75 mg immediately after ERCP (diclofenac group) or without (control group). The primary outcome measure was the occurrence of PEP. The serum amylase levels were measured before ERCP and at 3 and 24 h post-procedure in all patients. The Lipoxin A4 (LXA4), Resolvin D1 (Rvd1), and Resolvin E1 (RvE1) levels were measured before ERCP, and 3 and 24 h after the procedure in 30 patients from the diclofenac group and 30 patients from the control group. Results: A total of 120 patients were enrolled and completed the follow-up. The overall incidence of PEP was 13.3 % (16/120). It occurred in four of 60 patients (6.67 %) in the diclofenac group and in 12 of 60 patients (20.00 %) in the control group ( p = 0.032). The LxA4, RvD1, and RvE1 levels in the diclofenac group at 3 h after ERCP were significantly increased compared with before ERCP ( p < 0.05). Compared with the control group, the LxA4, RvD1, and RvE1 levels in the diclofenac group at 3 and 24 h after ERCP were significantly increased ( p < 0.05). Conclusions: Intramuscular diclofenac after ERCP can reduce the incidence of PEP. This may be related to the fact that diclofenac can increase the levels of LxA4, RvD1, and RvE1. [ABSTRACT FROM AUTHOR]

Purpose: This study aimed to investigate the effect of initial soil pH and organic anion-to-acid ratio on changes in soil pH. Materials and methods: Two soils (Podosol and Tenosol) along with two carboxylic acids (malic and citric acid) and their anions (sodium malate and citrate), commonly found in plant residues, were used in this study. Stock solutions of either malic acid and disodium malate or citric acid and trisodium citrate were added to pre-incubated soils at anion-to-acid ratios of 0:100, 10:90, 25:75, 50:50, 75:25, 90:10, 100:0 and at 0.25 g C kg soil. Soils were adjusted to 80 % field capacity and mixed thoroughly, and three replicates of 50 g of each soil were transferred into individual plastic cores and incubated at 25 °C in the dark for 30 days. Soil pH, respiration, NH, and NO were determined. Results and discussion: Soil pH increased linearly with increasing organic anion-to-acid ratio. The addition of organic anions to soil resulted in net alkalinisation. However, the addition of organic acids immediately decreased soil pH. During subsequent incubation, soil pH increased when the organic anions were decomposed. Alkalinity generation was lower in the Podosol (initial pH 4.5) than in the Tenosol (initial pH 6.2), and was proportional to anion-to-acid ratio across all the treatments. Cumulative CO-C release was approximately three times lower in the Podosol than the Tenosol at day 2 due to lower microbial activity in the low-pH Podosol. Conclusions: Increasing anion-to-acid ratio of organic compounds increased soil pH. Increases in soil pH were mainly attributed to direct chemical reactions and decomposition of organic anions. Low pH decreased the amount of alkalinity generated by addition of organic compounds due to incomplete decomposition of the added compounds. This study implies that organic anion-to-acid ratio in plant residues plays an important role in soil pH change. [ABSTRACT FROM AUTHOR]

Poor prognosis is associated with patients with metastatic colorectal cancer. To seek effective methods, we examine the efficacy and safety of bevacizumab plus FOLFIRI as a second-line chemotherapy in Chinese patients with metastatic colorectal cancer (mCRC). A total of 55 patients with previous failure of oxaliplatin-based chemotherapy were included in this study, from October 2010 to February 2012. All patients received bevacizumab (5 mg/kg) plus FOLFIRI every other week until disease progression or intolerable toxicity occurred. The response rate was 31 %, and the disease-controlled rate was 76.4 %. The median progression-free survival was 6 months, and the median overall survival was 17 months. Adverse events (AEs) related to chemotherapy were mild to moderate. Only the incidence of grade 3–4 neutropenia reached to 25.5 %. The incidence of AEs related to bevacizumab was low. These AEs included grade 3–4 toxicities of hypertension and proteinuria 5.4 and 3.6 %, respectively. Bevacizumab plus FOLFIRI is an effective and safe regimen as a second-line treatment for patients with mCRC in China. [ABSTRACT FROM AUTHOR]

MDPE- g-MAH copolymers were prepared with MDPE (medium density polyethylene) and MAH (maleic anhydride) under different irradiation doses of high-energy electron accelerator, and FTIR spectra confirmed their structure. The effect of the different contents of MDPE- g-MAH copolymers on properties of MDPE/CaCO system is studied intensively. By adding 4 Phr (parts per hundred of resin) MDPE- g-MAH in MDPE/CaCO system under irradiation dose of 0.7 MGy, the tensile strength increases from 16.3 MPa to 19.9 MPa, and elongation at break increases from 437% to 518%. SEM images show the domain size of CaCO in MDPE- g-MAH systems becomes small. Definitely, MDPE- g-MAH copolymer could improve the compatibility of MDPE/CaCO system effectively. [ABSTRACT FROM AUTHOR]

Purpose: The combined contamination of Pb, Zn, Cu, Cd, and As in the soils near lead/zinc mine waste posed a potential threat to the surrounding environment. Mitigation methods are needed to reduce the environmental risk. The aims of this paper were to evaluate the feasibility and efficiency of different forms of phosphates in remediating combined contamination caused by multi-metals and arsenic near the lead/zinc mining tailings. Materials and methods: The tested soil was taken from a clayey illitic thermic typic epiaquepts soil (depth of 0-20 cm) near a lead and zinc mine tailing, located in Shaoxing, Zhejiang Province, China. Four pure chemical reagents, KHPO, Ca(HPO).2HO, Ca(PO), and Ca(PO)OH, were added to the soil in solution form as the trace metal stabilizing additives at a P application rate equivalent to 2,283 mg P/kg-soil and P/Pb molar ratio of 1. Shifts in trace metal speciation were determined using sequential extraction procedures and relative toxicities were evaluated using the standard EPA toxicity characteristic leaching procedure (TCLP). Results and discussion: The addition of KHPO, Ca(PO), Ca(PO)OH, and Ca(HPO).2HO in the contaminated soil at the phosphorus application rate 2,283 mg P/kg-soil reduced Pb concentrations in TCLP extraction solution from 90.47 to 56.05, 83.80, 67.78, and 86.32 mg/kg (38.0, 7.36, 25.1, and 4.59% reduction), respectively. Sequential extraction analysis showed that phosphate treatments caused the transformation of easily available trace metal species to more stable forms. However, TCLP As in the soil increased from its initial value of 0.23 to 2.1, 0.70, 0.67, and 0.77 mg/kg, respectively, for the four treatments. The TCLP leachable As concentration of the KHPO-treated soil was about nine times of that from the untreated soil. Conclusions: The addition of KHPO, Ca(PO), Ca(PO)OH, and Ca(HPO).2HO were effective in reducing water soluble and exchangeable Pb, Zn, Cu, and Cd, and minimizing TCLP-extractable Pb, Zn, and Cu. The sequential extraction test and the TCLP indicate that Ca(PO)OH treatment has a higher potential in immobilizing Pb, Zn, Cu, and Cd, though a slight enhancement of As mobility, comparing with other phosphate treatments. [ABSTRACT FROM AUTHOR]

Background and Aims: Collagen type IV and hyaluronic acid (HA) are the major components of basement membrane and extracellular matrix, respectively. Cathepsin D is an aspartyl lysosomal protease involved in the degradation of the basement membrane and extracellular matrix. The aim of this study is to investigate the clinical significance of collagen type IV and hyaluronic acid in gastric juice and serum in diagnosis of gastric cancer and the degrading effect of cathepsin D on collagen type IV and HA.Methods: Fifty gastric cancer patients were enrolled in our study compared with 41 patients with precancerous lesion and 30 control subjects. Collagen type IV and HA in gastric juice and serum were analyzed by radioimmunoassay. Expression of cathepsin D and collagen type IV in tissue were analyzed by immunohistochemical staining with monoclonal antibodies.Results: The contents of collagen type IV and HA in gastric juice and HA in serum were significantly higher in patients with gastric cancer than those in patients with precancerous lesion and control group (p < 0.05, p < 0.0001). Gastric cancer patients with lymph node metastasis had a higher level of collagen type IV and HA in gastric juice than those in patients without metastasis (p = 0.049, p = 0.043). The expression of cathepsin D had significantly increased in patients with gastric cancer compared to the control group (p < 0.0001). The continuous expression of collagen type IV in basement membrane in gastric cancer group was lower than that in the precancerous lesion group and control group (p < 0.0001).Conclusions: The analysis of collagen type IV and HA in gastric juice and serum may provide a simple aid in diagnosing gastric cancer and evaluating whether metastasis is occurring or not. [ABSTRACT FROM AUTHOR]

Aim:This study investigated the effect of intragastrically administered melatonin on intestinal mucosal permeability induced by diclofenac in mice.Methods:Intestinal mucosal permeability was induced in mice by intragastric administration of diclofenac (2.5 mg/kg). Melatonin was given intragastrically (10 mg/kg) once per day for 3 d after diclofenac administration. The small intestine was examined macroscopically and microscopically for pathologic injury to the intestinal mucosa. Intestinal mucosal permeability was evaluated by Evans blue and FITC-dextran methods. Mitochondrial functional parameters, including mitochondrial membrane potential, mitochondrial ATPase and succinate dehydrogenase (SDH) activity, were assessed. The malondialdehyde (MDA) and myeloperoxidase (MPO) levels were determined from small intestinal mucosal homogenates.Results:As compared with control mice, the permeability, pathologic score, MDA and MPO levels and ulceration of the intestinal mucosa were increased significantly by diclofenac treatment, and a broadened junctional complex and enlarged intercellular space were observed by transmission electron microscopy (TEM). Melatonin treatment significantly reduced the intestinal mucosal permeability, pathologic score, MDA, and MPO levels and ulceration of the intestinal mucosa. By TEM, the small intestine villus morphology and intercellular spaces were nearly normal in melatonin-treated mice. At the level of the mitochondria, melatonin treatment significantly restored the activities of ATPase and SDH.Conclusion:The intestinal damage and increased intestinal permeability induced by diclofenac in mice was limited by melatonin; moreover, melatonin preserved several aspects of mitochondrial function. [ABSTRACT FROM AUTHOR]

Obesity is a medical condition in which excess body fat has accumulated to an extent and may have an adverse effect on health, leading to reduced life expectancy, impaired energy homeostasis and increased health problems. The p160 steroid receptor coactivator (SRC) gene family members have been suggested to be involved in energy homeostasis, but the impact of SRC-3 ablation on white and brown adipose tissue needs to be elucidated. In the current study, we collected in vivo data and carried out morphological studies on the effect of SRC-3 deficiency on white adipose tissue (WAT) and brown adipose tissue (BAT). Primary cells were cultured to investigate the differentiation ability of both adipocytes. Western blot was applied to detect the expression of master genes governing adipogenesis and thermogenesis. We observed that SRC-3−/− mice were lean, with reduced WAT and decreased serum leptin levels, mainly due to the smaller white adipocyte size caused by impaired adipogenesis, presented by decreased peroxisome proliferator activated receptor γ (PPARγ) expression. In the BAT, the lipid droplets decreased significantly in SRC-3−/− mice as demonstrated by histological analysis and electron microscopic observation, which could be explained by enhanced thermogenesis. The expression of thermogenic marker gene PPARγ coactivator 1α and uncoupling protein-1 increased in BAT of SRC-3−/− mice, which proved our observations. Collectively, these results demonstrate that SRC-3 plays a key role in adipogenesis and energy expenditure. [ABSTRACT FROM AUTHOR]

Background. Clinical trials of gefitinib (Iressa, ZD1839) in combination with cytotoxic agents have been carried out or are ongoing in several varieties of tumor. To provide a rationale for future clinical trials, the effects of combining gefitinib with oxaliplatin in different sequences of administration and different dose ratios in two colon cancer cell lines were evaluated. Materials and methods. The colon cancer cell lines HT-29 and LoVo were used. The methods consisted of median effect and combination index analysis, Western blot, mass spectrometry, and a cell death ELISA. Results. In vitro analysis demonstrated that the combination effects of the two agents were sequence-dependent. Changing the sequence of administration from gefitinib first to gefitinib last changed the combination effect from antagonism to synergy. The dose ratio between the two agents affected the combination effects. When equiactive doses of the two agents were used with the sequence gefitinib following oxaliplatin, the greatest level of synergism was obtained (CI=0.6±0.2, P=0.032). Further evaluation revealed that gefitinib significantly inhibited removal of Pt-DNA adducts (P<0.05), providing a potential explanation for the sequence-dependent synergy observed with gefitinib following oxaliplatin. However, this effect was not dose-dependent. Additional studies demonstrated that gefitinib enhanced the effects of oxaliplatin by maintaining oxaliplatin-induced apoptosis, and equiactive dose of gefitinib following oxaliplatin induced prominent enhancement of apoptosis. Conclusions. Oxaliplatin followed by an equiactive relative dose of gefitinib is an appropriate combination for evaluation in colon cancer. [ABSTRACT FROM AUTHOR]

In order to investigate the predictive value of in vitro MTT assay for directing chemotherapy of breast cancer patients, from 1992 to 1995, 156 advanced breast cancer patients who had evaluable lesions were recruited for a prospective study. Of them 83 had MTT assay before chemotherapthe 73 patients in the MTT sensitive group received chemotherapy according to the result of the MTT assay. The other 10 patients in the MTT resistant group and 73 patients in the control group were given chemotherapy according to clinicians' discretion. The response rate in the MTT sensitive group was 76.7% (56/73). There was statistically significant difference as compared with 0 (0/10) in the MTT resistant group and 43.8% (32/73) in the control group. Between in vitro and in vivo, the overall coincident rate was 79.5%[(56+10)/83]. In the MTT sensitive group, the response rate of the subgroups of lesions and the chemotherapy regiments tended to be higher than that in the control group. Patients in the MTT sensitive group had longer response and survival than those in the control group. However, there was no statistical difference in the median response duration and the median survival between the two groups. Further exploration of in vitro chemosensitivity testing by MTT assay for patients with advanced breast cancer is warranted. [ABSTRACT FROM AUTHOR]

Practical criteria were developed in this paper for the purpose of evaluating chemosensitivity of fresh human breast cancer by the MTT assay. The survival rates at maximum inhibition (Imax %) and the concentrations of drugs which caused fifty percent reduction in absorbance compared to baseline values (IC50) of 175 samples of 10 anti-tumor drugs were evaluated by logistic analyses of the dose-response curves. Distributions of Imax% appeared as normal curves, while those of the IC50 significantly deviated from normal distribution (p < 0.0001). We assessed the in vitro chemosensitivity by comparing the Imax % of each drug on individual samples with the mean Imax % + SD which was obtained from the Imax% of 175 samples. If the individual Imax % > mean Imax % + SD, we thought the tumor sample was resistant to this drug. If the Imax % ≤ mean Imax % + SD, we would compare its IC50 with Q50 which was used as a cutoff point for in vitro chemosensitivity of anti-tumor drugs. The in vitro chemosensitivity could be graded as sensitive (Q1–Q25), intermediate (Q26–Q75), and resistant (Q76–Q100) by means of percentile method. If the individual IC50 ≥ Q76, the tumor sample would be defined as resistant. If the individual IC50 ≤ Q25, it would be defined as sensitive. In the range of Q26–Q75, we used Q50 as a cutoff point between relative sensitivity and relative resistance. Preliminary results showed that the in vitro chemosensitivity to different anti-tumor drugs determined by these criteria were consistent with the clinical response in 83 advanced breast cancer patients. [ABSTRACT FROM AUTHOR]