[Correlations between genetic variations of glutathione synthetase gene and the response to platinum-based chemotherapy and prognosis of small cell lung cancer patients].

Objective: To explore the associations between genetic variations of glutathione synthetase gene (GSS) and response to platinum-based chemotherapy of small cell lung cancer(SCLC), and to analyze the influencing factors on survival. Methods: Four haplotype-tagging single nucleotide polymorphisms (htSNPs) of GSS were genotyped by Sequenom MassARRAY methods in 903 SCLC patients who received platinum-based chemotherapy, and had different response and survival time. The associations between genotypes and platinum-based chemotherapy response were measured by odds ratios (OR) and 95% confidence intervals (CI), adjusted for sex, age, smoking, KPS, staging and chemotherapy regiments, by unconditional logistic regression model. The hazard ratios (HR) were estimated by Cox proportional hazards regression model. Results: Among the 903 patients, 462(51.2%) cases received cis-platinum and etoposide treatment while others were treated with carboplatin and etoposide. 656 patients were chemotherapy responders in the study with a response rate of 72.6%. Patients were followed up to get their survival information. The median survival time (MST) of these patients was 25.0 months.We found that rs725521 located in the 3' near gene region of GSS was significantly associated with chemotherapy response. Compared with the T allele, patients with C allele had a worse chemotherapy response and an increased risk of no-responders (P=0.027). Rs7265992 and rs725521 of GSS were associated with the overall survival (OS) of SCLC patients who received platinum-based chemotherapy (HR=1.16, 95% CI=1.02-1.33, P=0.027; HR=1.17, 95% CI=1.05-1.31, P=0.006, respectively). The patients carrying 1 or 2 risk alleles and the patients carrying 3 or 4 risk alleles had worse MST than the patients without the rs7265992A and rs725521C risk alleles (24.0 and 22.0 versus 30.0 months), with the HR for death being 1.26 (95% CI=1.04-1.54) and with the HR of 1.52 (95%CI=1.18-1.97, P=0.001). Rs2025096 and rs2273684 were not associated with the OS of SCLC patients who received platinum-based chemotherapy. Age ≤ 56, KPS> 80, limited-stage, chemotherapy response and radiation therapy had a remarkably prolonged OS (all P<0.05). Conclusions: These results suggest that GSS genetic polymorphism rs725521 plays an important role in the response to platinum-based chemotherapy, while rs7265992 and rs725521 have important effect on the prognosis of SCLC patients, which may be potential genetic biomarkers for personalized treatment of SCLC.

[Genetic variation in DNA repair gene RAD52 is associated with the response to platinum-based chemotherapy in SCLC patients].

OBJECTIVE: To explore the associations between genetic variations of DNA repair gene RAD52 and response to platinum-based chemotherapy of small cell lung cancer (SCLC), and to analyze the influencing factors on survival. METHODS: Nine haplotype-tagging single nucleotide polymorphisms (htSNPs) of RAD52 were genotyped by Sequenom Mass ARRAY technology in 939 SCLC patients who received platinum-based chemotherapy, and had different response and survival time. The associations between genotypes and platinum-based chemotherapy response were analyzed by odds ratios (ORs) and 95% confidence intervals (CIs), adjusted for sex, age, smoking, KPS, staging and chemotherapy regimens, by unconditional logistic regression model. The relative ratios (RRs) were estimated using Cox proportional hazards regression model. RESULTS: Among the 939 cases, 483 (51.4%) cases received cis-platinum and etoposide treatment while others treated with carboplatin and etoposide. Six hundred and eighty two patients were chemotherapy responders in the study with a response rate of 72.6%. Patients were followed up to get their survival information. The median survival time (MST) of these patients was 25 months. We found that rs10774474 SNP which located in the 5'-flanking region of RAD52 was significantly associated with chemotherapy response. Compared with the TT genotype, patients with TA and AA genotype had a worse chemotherapy response and increased risk of no-response (P=0.004). Correlation analysis showed that patients with KPS >80 had a better chemotherapy response than those with KPS≤80 (P=0.001). The patients with extensive-stage had a worse chemotherapy response than those with limited-stage (P<0.001). Cox proportional hazards regression model analysis showed that nine htSNPs of RAD52 were not associated with the overall survival (OS) of SCLC patients who received platinum-based chemotherapy. Age≤56, KPS>80, limited-stage, chemotherapy response and radiation therapy can remarkably prolong OS (allP<0.05). CONCLUSIONS: These results suggest that RAD52 genetic polymorphism rs10774474 plays an important role in the response to platinum-based chemotherapy, and may be a potential genetic biomarker for SCLC personalized treatment.

Quality of functional haematopoietic stem/progenitor cells from cryopreserved human umbilical cord blood.

BACKGROUND AND OBJECTIVES: Transplantation of cryopreserved umbilical cord blood (UCB) can be used to treat a multitude of haematologic and immunological diseases. In this study, we examined the quality of UCB cryopreserved for 2 (group I), 4 (group II) and 6 (group III) years. METHODS: The following parameters and procedures were used to test individual units of cryopreserved UCB: the number of total nucleated cells (TNC), cell viability, CFU-GM assay, T-cell activation in vitro and haematopoietic stem cell engraftment in NOD/SCID mice in vivo. RESULTS: The TNC recovery rates for groups I, II and III were 106·2 ± 6·17%, 96·69 ± 6·39% and 100·38 ± 5·27%, respectively, and the mean percentages of viable cells after thawing were 86·88%, 86·38% and 87·43%. When TNC were plated at 5 × 10(3), the number of CFU-GM was 13·6 (group I), 13·8 (group II), 14·2 (group III) and 14·7 (fresh UCB). We confirmed that the huCD4(+) and huCD8(+) T cells within cryopreserved UCB are functionally responsive by assessment of activated huCD25(+) cells. Moreover, the percentage of huCD45(+) cells in the bone marrow was 4·32 ± 1·29% (group I), 4·48 ± 1·11% (group II), 4·40% ± 1·12% (group III) and 4·50% ± 0·66% (fresh UCB), and that in the peripheral blood was 14·69 ± 3·08% (group I), 15·24 ± 4·05% (group II), 15·74 ± 3·43% (group III) and 17·48 ± 3·74% (fresh UCB) in NOD/SCID mice infused with isolated huCD34(+) cells. CONCLUSION: These results indicated that cryopreserved UCB units efficiently retrieve in functionally competent form and are suitable for transplantation.

Effect of food coadministration on 5-aminosalicylic acid oral suspension bioavailability.

Single doses of 1 gm 5-aminosalicylic acid (5-ASA) suspension was administered to 24 healthy volunteers during both fasting and fed conditions. For subjects in a fasting state, plasma 5-ASA and acetyl 5-ASA concentrations peaked rapidly 1 hour after dosing to 14.72 micrograms/ml and 11.4 micrograms/ml, respectively. The elimination half-life of 5-ASA was 51.9 minutes, whereas the acetyl 5-ASA half-life could not be determined. A mean of 78.3% of the dose was excreted in the urine, with 5-ASA accounting for 21.2% of the dose and acetyl 5-ASA accounting for the balance. Only 11.3% of the dose was eliminated in the feces, consisting mostly of acetyl 5-ASA. Food coadministration reduced 5-ASA and acetyl 5-ASA systemic relative bioavailability to 44% and 76%, respectively, compared with the fasting treatment. Urinary excretion of the salicylates was reduced to 46.8%, and fecal salicylate elimination increased almost 100%--to 24.2% of the total dose.

The contribution of P-glycoprotein to pharmacokinetic drug-drug interactions.

P-glycoprotein (PGP) is well known because of its contribution to multiple-drug resistance during anticancer treatment. More recent work indicates that PGP mediates the transcellular transport of many drugs in addition to anticancer compounds. Because of this reason, its potential role in clinically significant drug-drug interactions has just begun to be realized. This article provides an overview of published in vitro, in situ, and in vivo drug-drug interaction results that are related to PGP transport so that the awareness of the scientific community can be heightened. In addition, several recommendations are made to take full advantage of the recently published data.

Selection of doses for phase II clinical trials based on pharmacokinetic variability consideration.

Pharmacokinetic variability is an important component of the total variability in drug response, but Phase II dose-response trials frequently are designed without considering this important factor. Mixed-effects model simulation was performed to examine overlap of patient area under the concentration-time curve (AUC) values between doses for drugs with differing inter- and intrapatient pharmacokinetic variability. Based on the results of this simulation, a dose increment of at least threefold is needed to ensure that drug exposure does not overlap in at least 50% of the patient population for a drug that exhibits greater than 25% variability. In contrast, an increment factor of 2 is normally sufficient to produce the same degree of resolution when the variability is less than 25%. These results suggest that a more aggressive choice of administration increments could lead to a better separation in systemic drug exposure between doses. This needs to be balanced against the therapeutic window of an individual drug product.

Pharmacokinetics of propylene glycol in humans during multiple dosing regimens.

The pharmacokinetics of propylene glycol has been examined during multiple oral-dosing regimens. The glycol is rapidly absorbed, with Cpmax observed within 1 h following administration. The terminal elimination half-life is approximately 4 h. After a minimum of 10 half-lives of maintenance dosing on a fixed regimen, the accumulation of propylene glycol differed significantly among individuals because of variability in apparent clearance. The average apparent total body clearance is approximately 0.1 L/kg X h and may be concentration dependent. The apparent volume of distribution is approximately 0.5 L/kg, approximating total body water.

Pharmacokinetics of dothiepin in humans: a single dose dose-proportionality study.

Dothiepin hydrochloride (N,N-dimethyldibenzo[b,e]thiepin-delta 11(6 H), gamma-propylamine hydrochloride) is a tricyclic antidepressant which is structurally similar to amitriptyline. Twenty-seven healthy men received three single oral doses of 50-, 100-, and 150-mg dothiepin hydrochloride capsules in a three-way randomized, crossover dose-proportionality study. Plasma concentration-time profiles of dothiepin (1) were described by both one- and two-compartment models with first-order absorption. The total intrinsic clearance of dothiepin decreased from 165.5 to 121.1 L/h as the dose was increased from 50 to 150 mg, but there was no significant effect on the terminal half-life (approximately 20 h). Plasma concentration-time profiles of the three major metabolites of dothiepin, the S-oxide derivative of dothiepin, N,N-dimethyl[b,e]thiepin-delta 11(6 H), gamma-propylamine 5-oxide (2), the demethyl derivative, N-methyldibenzo[b,e]thiepin-delta 11(6 H), gamma-propylamine (3) and the demethyl S-oxide derivative N-methyldibenzo[b,e]thiepin-delta 11(6 H), gamma-propylamine 5-oxide (4), were described by a one-compartment model with apparent first-order formation. The AUC infinity values of the S-oxide 2 and the demethyl S-oxide 4 increased proportionally with dose. The dose proportionality of the demethyl metabolite 3 may not be ascertained from the data in this study. The corresponding half-lives of the three metabolites, which are dose independent, were approximately 24, 28, and 40 h, respectively.

Smoking cessation among Hong Kong Chinese smokers attending hospital as outpatients: impact of doctors' advice, successful quitting and intention to quit.

To identify factors affecting current smokers' intention to quit smoking and factors associated with successful quitting among ex-smokers in Hong Kong. A cross-sectional survey of Chinese patients attending medical and surgical Specialist Outpatient Clinics (SOPCs) of public hospitals in Hong Kong, using a structured questionnaire. Results of the 642 respondents, 21% were current smokers, 9% were ex-smokers and 69% were non-smokers. 74% of the smokers reportedly received quitting advice from doctors. Among the current smokers, past quitting attempts, receiving information from sources other than doctors, believing that doctor's advice was useful, believing that all smokers should quit smoking and a positive attitude towards quitting were associated with intention to quit. Among those who had attempted to quit, being older (aged 50 or above), being retired/unemployed and consuming more than 10 cigarettes per day were associated with successful quitting. We found that advice from doctors on quitting smoking did not have any impact on Chinese smokers quitting or future intention to quit and reflect the inadequacy of advice given by Hong Kong doctors. The predictors of intention to quit and successful quitting identified in the study could be used to design future smoking cessation services.

Usefulness of the Hospital Anxiety and Depression Scale for screening for psychiatric morbidity in Chinese patients with Graves' ophthalmopathy.

OBJECTIVE: To examine the usefulness of the Hospital Anxiety and Depression Scale (HADS) for screening psychiatric morbidity in Chinese patients with Graves' ophthalmopathy. METHODS: A cross-sectional study was conducted from 1 January 2010 to 31 December 2010 at the specialist eye outpatient clinic at Pamela Youde Nethersole Eastern Hospital. All euthyroid patients diagnosed with Graves' ophthalmopathy were recruited. They were interviewed with the Chinese version of the HADS and the Structured Clinical Interview for the Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition Axis I. Demographic data and clinical background information were collected from the patients and their hospital records were reviewed. RESULTS: In all, 124 patients were recruited into the study. Current prevalence of psychiatric disorders was 32%, of which 19% were current depressive disorders and 19% were current anxiety disorders. The HADS provided the best discriminating power for screening for psychiatric morbidity at a cut-off threshold of 10/11. For screening of depressive and anxiety disorders, the cut-off thresholds were 4/5 and 6/7 respectively. CONCLUSION: Depression and anxiety disorders were common in the local population of patients with Graves' ophthalmopathy. Recognising the predictors for psychiatric morbidity could assist clinicians to identify those patients with a predisposition to developing psychiatric complications, and refer them for appropriate treatment. The HADS can be considered as a screening tool for psychiatric morbidity in patients with Graves' ophthalmopathy.

Downregulation of G3BPs inhibits the growth, migration and invasion of human lung carcinoma H1299 cells by suppressing the Src/FAK-associated signaling pathway.

G3BP is a RasGAP binding protein that is overexpressed in many human cancers. We previously reported that downregulation of G3BP suppressed cell growth and induced apoptosis in HCT116 cells. Here we report that both transient and stable knockdown of G3BP suppressed the growth, migration and invasion capability of human lung carcinoma H1299 cells. Moreover, downregulation of G3BP significantly inhibited the phosphorylation of Src, FAK and ERK, and the levels of NF-κB were also markedly decreased in H1299 cells. Knockdown of G3BP also decreased the expression of matrix metalloproteinase-2 (MMP-2), MMP-9 and plasminogen activator (uPA), and in vivo data demonstrated that downregulation of G3BP markedly inhibited the growth of H1299 tumor xenografts. Together, these data revealed that knockdown of G3BP inhibited the migration and invasion of human lung carcinoma cells through the inhibition of Src, FAK, ERK and NF-κB and decreased levels of MMP-2, MMP-9 and uPA.

Pharmacokinetics of propylene glycol in the rabbit.

Propylene glycol (PG) is widely used as a drug solvent in the pharmaceutical industry. However, it has produced central nervous system toxicity during chronic administration. The current study was undertaken to describe the pharmacokinetics of propylene glycol during acute and constant-rate intravenous dosing, using the rabbit as an animal model. In the acute dosing experiment, metabolism of PG was the dominant disposition pathway, characterized by concentration-dependent metabolic clearance. Renal excretion of PG accounted for only 2.4 to 14.2% of the total dose following acute administration due to significant reabsorption in the rabbit kidney. An ascending-convex relationship exists between renal clearance and urine flow. During constant-rate intravenous infusion studies, there was a disproportionate relationship between infusion rate and steady-state concentration, providing further evidence for capacity-limited disposition kinetics. The ascending-convex relationship between renal clearance and urine flow was also apparent in the long-term infusion studies.

Gas-liquid chromatographic determination of propylene glycol in plasma and urine.

We describe a gas-chromatographic assay for propylene glycol in human plasma and urine. The method is sensitive enough to allow quantification of the compound at concentrations observed clinically. It requires no derivative preparation and takes only 13 min of chromatographic time.

Public perception of safety and metal detectors in an urban emergency department.

Violence within the emergency department (ED) is an area of concern for both the staff and public. Emergency physicians and nurses express a great deal of concern for their personal safety. The use of weapons in events occurring in the ED has prompted a call for the widespread use of metal detectors. The use of these devices can meet with resistance regarding concerns over the creation of a bad image. This study examined the opinion of the public as to personal safety in an urban ED and sought public opinion regarding the use of a metal detector. Although the majority of the 303 persons surveyed felt safe (75%) in the ED and were satisfied with the level of security (68%), two thirds reported they would feel better if a metal detector was in use. Women were more likely than men to prefer the use of a metal detector. A small percentage (11%) of the public reported a fear of being physically harmed in the ED. Concerns about the potential for a negative image caused by use of a metal detector do not appear warranted in this urban ED.

A comparison of population and standard two-stage pharmacokinetic analyses of vigabatrin data.

Vigabatrin (VGB), an irreversible inhibitor of GABA, is being developed as an add-on therapy for uncontrolled complex partial seizure. A single-dose study was conducted in three groups of subjects with normal, mild-to-moderate, and moderate-to-severe renal impairment to examine the effect of renal function on the pharmacokinetics of VGB. Serial blood samples were collected up to 60 h following a single 750 mg oral dose of VGB for the quantitation of drug concentrations. The plasma VGB concentration-time data were analyzed by mixed-effects modeling to estimate population pharmacokinetic parameters and to identify any significant demographic covariates. The parameters of VGB were also calculated by standard two-stage techniques and then compared to the results obtained using the mixed-effects analysis. Population VGB plasma concentration-time profiles were best described by a two-compartment model with zero-order absorption. Creatinine clearance was observed to significantly affect the oral clearance of VGB (p < 0.05), i.e. a linear increasing relationship existed between the two variables. Other demographic factors had no influence on VGB pharmacokinetics. There were agreements in the oral clearance, apparent volume of distribution during elimination, and half-life estimates calculated by both methods. In addition, the conventional technique identified a linear relationship between oral and creatinine clearances. In summary, mixed-effects modeling of serial vigabatrin data validated results determined by the standard two-stage technique.

A limited sampling method for the estimation of vigabatrin maximum plasma concentration and area under the curve.

A limited sampling model (LSM) was developed to estimate the area under the curve (AUC) and maximum plasma concentration (Cmax) for a 1-g oral dose of vigabatrin. The model was developed using the data from 10 healthy subjects and one time point. The following equations describe the model for AUC and Cmax: AUC(predicted) = 5.4 x C3h + 70 and Cmax(predicted) = 0.18 x AUC(0-infinity) + 9.4. The model was validated in 49 subjects who orally received 1-g vigabatrin. This LSM was also used to predict AUC and Cmax volunteers who received 2- and 4-g vigabatrin doses and in renal failure patients who were given a 0.75-g dose. The model provided good estimates of both AUC and Cmax in all groups of subjects except renal dysfunction patients. The method described here may be used to estimate AUC and Cmax of vigabatrin without detailed pharmacokinetic studies.

Pharmacokinetics of nitroglycerin and metabolites in humans following oral dosing.

Single dose oral nitroglycerin (GTN) was administered to six healthy subjects as 6.5, 9.0, and 13.0 mg aqueous solutions in sequential study phases to characterize the oral pharmacokinetics of GTN and the dinitrate metabolites. Blood samples were collected periodically up to 10 h. Plasma concentrations of GTN were measurable in some subjects up to 1/2 and 1 h, respectively, after the 9.0 and 13.0 mg dose. The mean GTN Cmax values of the three solution doses were 0.28, 0.78, and 0.42 ng ml-1 in ascending dosage. The erratic nature of GTN plasma profiles prevented meaningful pharmacokinetic analysis, although tmax was consistently 5 min. In all three treatments, both GTN metabolites (1,2- and 1,3-glyceryldinitrates, GDNs) peaked at about 20 min, followed by a distributive phase and a log-linear decline in concentrations. Terminal half-lives for both GDNs were approximately 50 min in all three doses. The plasma concentrations of the metabolites were higher than nitroglycerin with 1,2-GDN exhibiting the highest overall profile.

[The design and application of ML-2 ECG lead converter/selector].

AIM: Because no ECG lead cable and lead selector is equipped, SYD-4228 Physiology Experiment System can not be used to record and observe ECG. This paper introduces an ECG lead converter/selector designed and implemented by us. METHODS: With resistor network and lead input cable, an ECG lead converter/selector was produced. RESULTS: As an independent and assistant part of SYD-4228 system, this ECG lead converter/selector can be used to record ECG waveform in animal experiment. CONCLUSION: Capable of matching both SYD-4228 system and other ECG recording systems, this ECG lead converter/selector can record ECG waveforms with different lead systems simultaneously. Real-time observation and comparison of waveforms recorded by different lead systems can be available.