Effects of atorvastatin on progression-regression of renal injury in hyperlipidemic chickens

Complex interrelationships exist between hyperlipidemia and the progression of renal injury. The aim of this study was to evaluate the impact of high plasma cholesterol and triglyceride levels on renal structure and the effects of atorvastatin on progression-regression of renal injury. One-hundred chickens were divided into five groups: Group A: Standard diet (SD) for 6 months; Group B: Hyperlipidemic diet (HD) for 6 months; Group C: HD for three months and SD during the next 3 months; Group D: HD for 3 months and SD during the next 3 months, when they received oral atorvastatin (3 mg/kg/d); Group E: HD for the whole 6 months, and atorvastatin (3 mg/kg/d) during the last 3 months. Increased alpha-actine immunostaining was found in glomeruli of groups B and C. An important decrease of immunostaining was observed in glomeruli of atorvastatin treated groups. Group D showed the lowest value for presence of lipids, and significant differences were found with respect to the rest of the groups. The glomeruli of group B presented the highest damage grades and those of group D showed the lowest grades and presented significant differences from the rest of the groups. The combination of atorvastatin therapy and proper diet proved to be effective in promoting renal disease regression. However, the study of several parameters indicates that neither only diet nor atorvastatin in the progression group resulted completely effective in decreasing the progression of the disease.

[The use of the International Affective Picture System for the study of affective dysregulation in mental disorders]

INTRODUCTION

The International Affective Picture System (IAPS) uses a series of emotional, normative and internationally accessible pictorial stimuli and is considered to be the most reliable and valid system in the experimental study of emotions. The IAPS has been used in research on mental disorders such as schizophrenia, major depression, anxiety or psychopathic personality traits. Furthermore, it is frequently used as independent variable in neuroimaging studies. Some of the approaches to borderline personality disorder consider that the fundamental psychopathological element in these subjects is affective dysregulation, from which the principal symptoms such as intolerance to frustration, reactivity or dysphoria are derived. This review paper has aimed to gather and analyze the information on the study of emotional regulation and the use of the IAPS in the different mental disorders.

METHODS

A review is made of the different data bases of the studies published in the general population and in the clinical populations as well as of the internal characteristics of the test.

RESULTS

In agreement with the results described in the studies reviewed, the IAPS seems capable of defining specific responses to stimuli in different mental disorders, including mood disorders and schizophrenia.

CONCLUSIONS

In conclusion, the use of the IAPS in the study of borderline personality disorder could be of interest for the understanding and treatment of borderline personality disorder in which emotional dysregulation is a principal factor.

Mortality attributable to passive smoking in Spain, 2002

OBJECTIVE

Exposure to environmental tobacco smoke (ETS) is associated with a variety of health effects, including lung cancer and ischaemic heart disease. The objective of this study was to estimate the number of deaths caused by exposure to ETS among non-smokers in Spain during the year 2002

METHODS

Prevalence of ETS exposure among never smokers was gathered from three region based health interview surveys. The relative risks of lung cancer and ischaemic heart diseases were selected from three meta-analyses. Population attributable risk (PAR) was computed using a range of prevalences (minimum-maximum). The number of deaths attributable to ETS was calculated by applying PARs to mortality not attributable to active smoking in 2002. The analyses were stratified by sex, age and source of exposure (home, workplace and both combined). In addition, a sensitivity analysis was performed for different scenarios.

RESULTS

Among men, deaths attributable to ETS ranged from 408 to 1703. From 247 to 1434 of these deaths would be caused by the exposure only at home, 136-196 by exposure only in the workplace and 25-73 by exposure at both home and the workplace. Among women, the number of attributable deaths ranged from 820 to 1534. Between 807 and 1477 of these deaths would be caused by exposure only at home, 9-32 by exposure only in the workplace and 4-25 by exposure both at home and in the workplace.

CONCLUSION

Exposure to ETS at home and at work in Spain could be responsible for 1228-3237 of deaths from lung cancer and ischaemic heart disease. These data confirm that passive smoking is an important public health problem in Spain that needs urgent attention.

[Long-acting injectable risperidone in treatment resistant borderline personality disorder. A small series report]

INTRODUCTION

Borderline personality disorder (BPD) is usually treated with a combination of antipsychotic and anticonvulsant drugs although only limited efficacy is obtained in many patients. A major problem in the treatment of BPD is the lack of compliance derived form the pathological impulsivity of BPD patients.

METHODS

Twelve severe BPD patients refractory to previous treatment with drug combinations for three months were treated with intramuscular long-acting risperidone for a six-month period. Clinical changes were rated with the Clinical Global Impression (CGI), the Brief Psychiatric Rating Scale, anxiety and aggression scales. Functional improvement was evaluated with the Global Assessment of Functioning (GAF).

RESULTS

Six-month treatment with IM risperidone was associated with significant improvement of CGI (t: 5.7 - 4.0; p<0.01) and of GAF (t: -4.5; gl: 10; p<0.01). Clinical improvement was robust after the first month of treatment. No relevant extrapiramidal side effects were reported with the exception of mild psychomotor slowing which requires dose adjustments in four patients.

CONCLUSIONS

Treatment with i.m. long acting risperidone during six months was associated with significant clinical and functional improvement and excellent tolerability in a group of BPD patients refractory to previous treatment. The results indicate that the effect of IM risperidone in BPD should be further investigated in large placebo-controlled trials.

Disposition kinetics and pharmacokinetics–pharmacodynamic integration of difloxacin against Staphylococcus aureus isolates from rabbits

The pharmacokinetics of difloxacin were studied following intravenous (IV), subcutaneous (SC) and oral administration of 5mg/kg to healthy white New Zealand rabbits (n = 6). Difloxacin concentrations were determined by HPLC assay with fluorescence detection. Minimal inhibitory concentrations (MICs) assay of difloxacin against different strains of S. aureus from different european countries was performed in order to compute the main pharmacodynamic surrogate markers. The plasma difloxacin clearance (Cl) for the IV route was (mean +/- SD) 0.41 +/- 0.05 L/h kg. The steady-state volume of distribution (V(ss)) was 1.95 +/- 0.17 L/kg. The terminal half-life [Formula: see text] was (mean+/-SD) 4.19+/-0.34 h, 7.53 +/- 1.32 h and 8.00 +/- 0.45 h after IV, IM and oral, respectively. From this data, it seems that a 5 mg/kg dose difloxacin would be effective by SC and oral routes in rabbits against bacterial isolates with MIC0.1 microg/mL.

Methodologies used to estimate tobacco-attributable mortality: a review

BACKGROUND

One of the most important measures for ascertaining the impact of tobacco on a population is the estimation of the mortality attributable to its use. To measure this, a number of indirect methods of quantification are available, yet there is no consensus as to which furnishes the best information. This study sought to provide a critical overview of the different methods of attribution of mortality due to tobacco consumption.

METHOD

A search was made in the Medline database until March 2005 in order to obtain papers that addressed the methodology employed for attributing mortality to tobacco use.

RESULTS

Of the total of 7 methods obtained, the most widely used were the prevalence methods, followed by the approach proposed by Peto et al, with the remainder being used in a minority of studies.

CONCLUSION

Different methodologies are used to estimate tobacco attributable mortality, but their methodological foundations are quite similar in all. Mainly, they are based on the calculation of proportional attributable fractions. All methods show limitations of one type or another, sometimes common to all methods and sometimes specific.

Nodavirus increases the expression of Mx and inflammatory cytokines in fish brain

Nodavirus has become a serious pathogen for a wide range of cultured marine fish species. In the present work, the expression of genes related to immune and inflammatory responses of sea bream (Sparus aurata L.), considered as non susceptible species, was studied both in vitro and in vivo. No replication of the virus was observed in head kidney macrophages and blood leukocytes. Moreover, the enhancement of expression of several immune genes (tumor necrosis factor alpha (TNFalpha), interleukin-1-beta (IL-1beta), interferon-induced Mx protein) was not detected in both head kidney macrophages and blood leucocytes in response to an in vitro infection with nodavirus. However, in vivo, nodavirus was detected 1 day post-infection (p.i.) by a reverse transcription-polymerase chain reaction (RT-PCR) in blood, liver, head kidney and brain of experimentally infected sea bream, while its presence clearly decreased in blood after 3 days p.i. Also, a transitory increment of the expression of TNFalpha and IL-1beta was detected in the brain of intramuscular (i.m.) infected sea bream 3 days p.i. In head kidney, the over expression of TNFalpha was only observed 1 day p.i. The expression of Mx, an interferon induced gene, was increased in brain and head kidney of infected sea bream, reaching values of 1300-fold compared to controls in brain three days post-infection. For comparative purposes, we analyzed the expression of the same genes on a susceptible species, such as sea bass (Dicentrarchus labrax) and, although the same pattern of expression was observed both in brain and kidney, the magnitude was different mainly in the case of brain, the key organ of the infection, where higher expression of TNFalpha and lower expression of Mx compared with control was observed.

Role of ERCC1, XRCC3, Aurora A and TGFBR1 single-nucleotide polymorphisms (SNP) and CHFR and 14–3-3σ methylation in a customized cisplatin (cis) trial based on ERCC1 mRNA levels in stage IV non-small cell lung cancer (NSCLC) patients (pts)

7687

Background: The primary aim of this trial was response. In both the control arm and in the genotypic arm with low tumor ERCC1 mRNA levels, pts received docetaxel (doc)/cis; in the genotypic arm with high tumor ERCC1 mRNA levels, pts received doc/gemcitabine. Response was significantly higher in the genotypic arms. We examined 324 pts for genetic markers that could influence response, including ERCC1 118 C/T, ERCC1 C8092A, XRCC3 241 (Thr to Met), Aurora A 91 T>A, Aurora A 169G>A, a SNP within intron 7 of the TGFBR1 gene (Int7G24A), and an in-frame germline deletion (TGFBR1*6A). Methylation of 14–3-3s and CHFR were also analyzed. Methods: DNA from peripheral lymphocytes was used for genotyping (Taqman assay) and methylation-specific PCR was used for 14–3- 3s and CHFR in pretreatment serum DNA. Results: There were no differences in clinical characteristics among the different SNP types, except that pts with Aurora A 91 AA had higher tumor ERCC1 mRNA levels (P=0.005). No relationship was found between ERCC1 SNPs and tumor ERCC1 mRNA levels. A strong correlation was found between the Int7G24A and XRCC3 241 SNPs (P=0.03). The Int7G24A GA type had a higher odds ratio (OR) of response (OR 2.32) than the AA type (OR 3.15) (P=0.02). XRCC3 241 MetMet had a lower probability of response (OR 0.23) (P=0.04). No other differences in response were observed according to any of the other SNPs or methylation. In the multivariate model, the best response was observed in pts with performance status (PS) 0, low ERCC1 levels, and XRCC3 241 SNP ( Table ). Conclusions: Further research is warranted to define the role of theTGFBR1 Int7G24A gene in customized treatments.

No significant financial relationships to disclose.

[Table: see text]

A prospective phase II trial of erlotinib in advanced non-small cell lung cancer (NSCLC) patients (p) with mutations in the tyrosine kinase (TK) domain of the epidermal growth factor receptor (EGFR)

7020

Background: The EGFR TK inhibitor erlotinib is a standard treatment in previously treated NSCLC p. Recently, EGFR gene mutations have been reported to be a predictor of efficacy of this and related compounds. This phase II trial evaluated the efficacy and safety of erlotinib in untreated p with advanced NSCLC and mutated EGFR. Methods: Eligibility criteria included stage IIIB-IV chemotherapy-naive p with confirmed NSCLC and mutated EGFR, PS 0–2, age ≥ 18 years, adequate organ functions, measurable disease and written informed consent. DNA was extracted by laser capture microdissection. Exon 19 deletions were examined by Genscan and the L858R and T790M mutations with a TaqMan assay. Mutations were confirmed by sequencing. Erlotinib was given orally at 150 mg per day. Results: From March to December 2005, 37 (12.5%) of 297 tumors screened were found to have mutations in the TK domain of the EGFR gene (25 deletions; 11 L858R; no T790M). Median age: 68 years; 12 males, 25 females; histology: 28 adenocarcinoma, 4 BAC, 4 large cell carcinoma; 9 smokers. Response has been evaluated in 21 p so far: complete response, 6 p; partial response, 13 p; progressive disease, 2 p; overall response rate, 90% (95% CI:70%-90%). Responses occurred in 100% of tumors with exon 19 deletions and in 75% of those with L858R. All responses are ongoing (up to ≥8 months) and all but one p are still alive. Toxicity profile was predictable (mild to moderate rash, diarrhea, asthenia and emesis). No drug related severe adverse events occurred. Conclusions: Single-agent erlotinib produces a high response rate in previously untreated p with advanced NSCLC and mutated EGFR. In-frame deletions in exon 19 seem particularly predictive for response in this setting.

[Table: see text]

Randomized phase III study of high-dose sequential chemotherapy (CT) supported by peripheral blood progenitor cells (PBPC) for the treatment of small cell lung cancer (SCLC): Results of the EBMT Random-ICE trial

7064

Background: EBMT has defined in a phase II trial (JCO 1999, 3531) feasibility and activity of high-dose sequential CT for SCLC increasing 3 fold the dose-intensity and significantly the peak-dose and the total dose of CT. Methods: Randomized prospective study aiming to improve the 3-year survival from 12% in the standard (S) to 24% in the high-dose (H) arm, for a total accrual of 340 patients. Limited or extensive ≤ 2 metastatic sites, age ≤ 65 y.o., PS 0–1. Arm S/Arm H: ifosfamide 5 g/m2 d1/2.5 g/m2/d × 4; carboplatin 300 mg/m2 d1/AUC = 5/d × 4; etoposide 180 mg/m2/d. × 2/300 mg/m2/d × 4, every 28 days, for 6 cycles in Arm S. Three cycles were given in Arm H supported by PBPC collected after 2 courses of epirubicin 150 mg/m2/paclitaxel 175 mg/m2. Due to low accrual, a formal stopping rule was introduced with boundaries for early stopping in favour of a difference (O’Brien-Fleming) or of lack thereof (Pocock). The present analysis has been done with 110 deaths. Results: Since June 1997, 145 patients have been accrued (evaluable =140, S = 71, H = 69), median age 53, prognostic factors balanced. Mobilization toxicity ≥ 3: neutropenia 61%, thrombopenia 11%, anemia 7%, infection 6%, mucositis 9% and 2 toxic deaths. Toxicity ≥ 3 among 353 cycles of S and 152 of H respectively: neutropenia 26%/100%, thrombopenia 12%/100%, anemia 8%/69%, infection 1%/15%, fever 11%/72%, toxic death 1/8. Response rate of S and H: 67% (CR 32%)/77% (CR 37%) (p = 0.188). Median follow-up 4.9 years. Progression free survival 8.8 and 12 months (p = 0.737, unadjusted) and median overall survival 15 and 19.1 months (p = 0.659, unadjusted) for S and H respectively. At 3 years, 19% of the patients were alive in both arms. Conclusions: Random-ICE was designed with strong statistical power and shows no evidence that the treatment of SCLC can be improved by increasing the dose-intensity, the peak-dose or the total dose of ICE and that such intensification strategy should probably be abandoned.

No significant financial relationships to disclose.

Phase I clinical and pharmacological trial of trabectedin (T) in 3 hour infusion every 3 weeks (3h/q3w) in patients with advanced cancer and hepatic function disorder

2080

Background: Trabectedin (ET-743) is a marine-derived DNA and transcription interacting agent with activity in pretreated soft tissue sarcoma, breast, prostate and ovarian cancer. T is associated with 2 types of liver function alterations: a frequent acute and reversible elevation of ALT and AST and a less frequent cholestasis, usually reflected by low grade increases in alkaline phosphatase (AP) and bilirubin (B). The main predictors of dose limiting toxicity (DLT) or T-related serious adverse events appear to include elevated baseline or intercycle peaks of AP, B and ALT > 5 × ULN (Gomez J, ASCO 2000). The objectives of this trial are to determine the maximum tolerated dose (MTD) and pharmacokinetics (PK) of T 3h/q3w in patients (pts) with advanced cancer and baseline liver dysfunction. Methods: All pts are stratified according to basal liver function as follows: STRATUM (S) I: ULN < AP ≤ 1.5 × ULN S II: 1.5 × ULN < AP ≤ 2.5 × ULN S III: AP > 2.5 × ULN All pts had to have AST and ALT ≤ 2.5 × ULN, albumin > 2.5 g/dl and B < 2.5 mg/dl. T concentrations in plasma are determined using a validated LC-MS/MS method. PK parameters were calculated by non-compartmental methods. Results: 32 pts were recruited.Median age: 54 years (26–76); PS≤1:28 pts; prior chemotherapy (CT): 31 pts (97%); median number of prior CT: 2 (1–6); B > ULN: 0 pts. In S I, T was administered at 1.1 mg/m2 (3 pts) and 1.3 mg/m2 (13 pts). Two DLTs were reported at 1.3 mg/m2: neutropenia G4 > 5 days with febrile neutropenia and G3 ALT not recovered by day +28. In S II no DLT occurred in 4 pts at T 0.9 mg/m2 nor 3 pts at T 1.1 mg/m2, 1 out of 4 pts at 1.3 mg/m2 suffered DLT: G3 AST not recovered by day +24. In S III one out of 2 pts at 0.9 mg/m2 had DLT: AP increase. Initial PK evaluation from S I and II (8 from each) showed a long half life (geometric mean (GM) S I: 124.6 h, S II: 118.8 h) and wide distribution (GM Vss S I: 2366 l/m2, S II: 3830 l/m2). GM clearance: 18.3 l/(hr*m2) in S I; 26.3 l/(hr*m2) in S II. Clearance is somewhat lower than in normal liver function population (GM under equal dexamethasone treatment 33.8 l/hr*m2) in study ET-B-010. Conclusions: The recommended dose (RD) of T for pts with mild AP elevations (< 1.5 ULN) and B levels < ULN is 1.3 mg/m2 3h/q3w. The study is ongoing to define the RD for S II and III

[Table: see text]

Erlotinib in patients with advanced squamous cell carcinoma of the lung

7174

Background: Erlotinib is a potent HER1/EGFR TKI that is approved for the treatment as a single agent in 2nd and 3rd line NSCLC. Several phase II studies have shown that adenocarcinoma histology together with female gender, Asian origin, and never having smoked are associated with responsiveness of NSCLC to erlotinib. The purpose of the analyisis we present here was to describe the outcome in a group of patients with squamous carcinoma of the lung treated with erlotinib. Methods: Eligilibility criteria included stage IIIB-IV chemotherapy-naive patients with confirmed NSCLC, PS 0–2, age ≥ 18 years, adequate organ functions, measurable disease and written informed consent. Patients with diagnosis of squamous cell lung cancer that received erlotinib 150 mgr/day p.o until disease progression or withdrawal were the subject of this analysis. Results: From June 2004 to March 2005, 121 patients with histological diagnosis of squamous cell lung cacer from more than 100 different Spanish hospitals were included in the TARGET study. Median age was 66 yrs. All patients in our analysis were Caucasian. 111 patients were male (92%) and 113 (93%) were current smokers or have smoke sometime in their life. 88% of them have stage IV carcinoma and 74% have received previous treatment for metastatic disease. PS 0/1/≥2 18 (15%)/68 (56%)/32 (29%). In the evaluable population for response (69 pts) 5 PR and 0 CR were observed for an overall RR of 7.25%. Clinical benefit defined as CR+PR+SD was 54%. In the ITT populations median TTP was 3.6 months [95% CI 2.7–5.3]. Median OS was 5,7 m [95% CI 4.0–6.7]. Erlotinib was well tolerated.No unexpected toxicities were observed. Conclusions: This subgroup analysis confirms that erlotinib is active and well tolerated in patients with advanced or metastatic squamous cell carcinoma of the lung. Responses were seen in both genders and in patients with or without smoking history. At this moment histology should not be used as the only selection criteria for treatment of patients with NSCLC after failure to chemotherapy.

[Table: see text]

Mitotic checkpoint gene CHFR methylation in pretreatment serum DNA of docetaxel (doc)/cisplatin (cis)-treated stage IV non-small cell lung cancer (NSCLC) patients (p)

7056

Background: CHFR (checkpoint with forkhead-associated and ring finger) regulates a prophase delay in cells exposed to agents that disrupt microtubules. Epigenetic inactivation of CHFR is a frequent event in human tumors, leading to impaired checkpoint function and enhanced sensitivity to docetaxel. We hypothesized that serum DNA methylation of CHFR could be a predictor of longer survival in p treated with doc/cis. Methods: Sodium bisulfite modified serum DNAwas used as the template for methylation-specific PCR assay. DNA was obtained from 600 doc/cis-treated stage IV NSCLC p. Results: Preliminary data on 301 p is available. The frequency of CHFR hypermethylation was 32.6%. There was no association between methylation and performance status (PS), age, gender, histology, response, 14–3-3σ serum DNA methylation, polymorphisms in lymphocyte DNA (ERCC1 118 C/T, ERCC1 C8092A, XRCC3 241 ThrMet), or tumor ERCC1 mRNA levels. Overall, there was a tendency to better median survival (MS) for p with methylated CHFR. In p with PS 0, MS was 33 months (m) for 41 p with methylated CHFR and 12 m for 64 p with unmethylated CHFR (P = 0.23). In p >66 years (y), MS was not reached for 31 p with methylated CHFR and 9.6 m for 80 p with unmethylated CHFR (P = 0.01), while in p <66 y, MS was 9.4 m for 67 p with methylated CHFR and 10 m for 123 p with unmethylated CHFR (P = 0.62). p with both 14–3-3σ and CHFR methylation showed a tendency to longer survival. Final data on 600 p will be presented. Conclusions: Early findings indicate that CHFR methylation in elderly p predicts a significant survival benefit in doc/cis-treated NSCLC.

No significant financial relationships to disclose.

Erlotinib as single agent in patients (p) with advanced or metastatic NSCLC: A multivariate analysis in a prospective study

7180

Background: Erlotinib is the first orally available selective EGFR tyrosine-kinase inhibitor that improves survival in 2nd and 3rd line therapy for NSCLC. This non-randomised, phase II trial evaluated the efficacy and safety of erlotinib in patients with advanced or metastatic NSCLC. Methods: Patients with previously treated advanced or metastatic NSCLC or patients that were not suitable for first line conventional chemotherapy, stage IIIB/IV, PS 0–2 were enrolled to receive erlotinib 150 mg/day until disease progression or withdrawal. The primary endpoint of the study was time to progression (TTP) in the intent to treat (ITT) population. A multivariate analysis (Cox-model) was performed. Results: 416 patients were enrolled from June 04 to March 05. Demographics: M 78%/F 22%; median age 64 y [range 28–100]; stage IV 91.6%; PS 0/1/≥2: 65 (16%)/227 (55%)/105 (25%); adeno histology 178p (43%), SCC 121p (29%), BAC 3p (0.7%), LLC 2p (20%), other 29p (7%); smoking status: yes 349 p (84%) no 62 p (15%). 1st line: 60p (14.4%); 2nd line 181p (43.5%) and ≥ 3rd line 175p (42%). 230 patients had measurable disease and were evaluable for response: 1CR, 30 PR (ORR: 13.4%), 98 SD, and 101 PD. Toxicity was predictable (mainly rash, and diarrhoea). In the ITT population the median TTP was 3.2 m [95% CI 2.8–3.6]. For evaluable population median TTP was 4.6 m in 1st line, 3.23 m in 2nd line, and 2.8 m in 3rd line. Exploratory analysis showed that ORR was associated with gender, smoking history, previous treatment and histology. The multivariate analysis for TTP showed that no smoking history (p < 0.005), adeno histology (p < 0.0001), and erlotinib as 1st line treatment (p < 0.02) correlated with better TTP. Conclusions: Erlotinib is an active and very well tolerated treatment in patients with advanced NSCLC untreated or that have previously failed to conventional chemotherapy. Our data suggest that non smoking history, adeno histology and erlotinib as 1st line treatment are associated with better TTP. The study is ongoing.

[Table: see text]

Treatment of malignant superior vena cava syndrome by endovascular stent insertion. Experience on 52 patients with lung cancer

BACKGROUND

Superior vena cava syndrome (SVCS) is a frequent presentation of malignancies involving the mediastinum and can seriously compromise treatment options and prognosis. Stenting of superior vena cava is a well-known but not so commonly used technique to alleviate this syndrome.

PATIENTS AND METHODS

Between August 1993 and December 2000 we performed 52 stenting procedures in patients affected by non-small cell lung cancer (NSCLC).

RESULTS

Phlebographic resolution of the obstruction was achieved in 100% of cases with symptomatic and subjective improvement in more than 80%. One major complication was observed due to bleeding during anticoagulation. Re-obstruction of the stent occurred in only 17% of the cases, the majority due to disease progression. Improvement of the syndrome allowed hydration necessary for full dose platinum treatment when indicated in patients affected by lung cancer.

CONCLUSIONS

Stenting of the superior vena cava syndrome is a safe and effective procedure achieving a rapid alleviation of symptoms in almost all patients, and allowing for full dose treatment in lung cancer patients. This procedure could change the traditional poorer prognosis attributed to non-small cell lung cancer patients presenting with this syndrome.

Simple method to determine the size of the laryngeal mask airway in children

BACKGROUND AND OBJECTIVE

The size of the laryngeal mask airway in children is determined by the patient's weight. However, in some instances an alternative method may be wanted. The aim was to search for a new method that would be easy to perform at the bedside.

METHODS

The size of the laryngeal mask airway was determined in 183 children by choosing the laryngeal mask that best matched the combined widths of the patient's index, middle and ring fingers. The results were compared with the standard method recommended by the manufacturer's weight-related guidelines. The patients were classified in different groups depending on the laryngeal mask airway sizes determined by both methods. A kappa coefficient evaluated the agreement between both techniques.

RESULTS

The kappa coefficient was 0.81, showing an 'excellent agreement' between both methods. The size was the same for both methods in 142 children (78%). The disagreement between both techniques was only of one size in the remaining 41 patients (22%). In such patients, the weight was a borderline value that would indicate a change in the size of the laryngeal mask airway using the classic method.

CONCLUSIONS

This new approach is of valid and practical use in children, particularly as an alternative in those situations where the patient's weight is unknown, such as in emergency situations or in those borderline instances where an alternative measurement would be useful.

Cholesterol cell content modulates GTPase activity of G proteins in GH4C1 cell membranes

Previous results from our laboratory showed that GH(4)C(1) cells with low-cholesterol cell content had increased adenylyl cyclase (AC) activity with a parallel increase in G protein alpha subunits associated to the plasma membrane. This effect was directly related to mevalonate availability. In the present report, we characterized the high-affinity GTPase activity present in GH(4)C(1) cell membranes and studied its regulation by cholesterol cell content. The high-affinity GTPase activity, measured as the [gamma32P]GTP hydrolysis rate, was both time-dependent and protein concentration-dependent. Cultured cells with lipoprotein-deficient serum (LPDS) showed decreased cholesterol cell content and decreased GTPase activity. The kinetic analysis, as interpreted by Lineweaver-Burk plots, indicated that low-cholesterol cell content had no effect on the apparent affinity for GTP, but resulted in a 47% decrease in the maximal velocity of the reaction. Addition of 25-hydroxycholesterol (25-HC), an inhibitor of the expression of 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase and synthetase to cells in LPDS, further decreased GTPase activity in a dose-dependent manner. This effect was reverted by exogenous cholesterol, but not by mevalonate. Studies with bacterial toxins revealed that neither cholera toxin (CTX) nor pertussis toxins (PTX) were able to revert the inhibition produced by low-cholesterol cell content. These results allowed us to postulate that cholesterol modulates GTPase activity in both Gs and Gi protein families. To analyse further the mechanism of modulation of GTPase activity by cholesterol cell content, [35S]GTPgammaS binding in membranes of GH(4)C(1) cells was studied. Changes in cholesterol cell content did not have any effect on GTP binding. Data demonstrated that high-affinity GTPase activity in plasma membrane of GH(4)C(1) cells is direct stimulated by cholesterol cell content and not by mevalonate availability. This example provides a mechanism by which cholesterol cell content can modulate signal transduction mediating by G proteins.

Effects of haemolysis, lipaemia, bilirubinaemia and fibrinogen on protein electropherogram of canine samples analysed by capillary zone electrophoresis

The possible interference of haemolysis, lipaemia, bilirubinaemia and fibrinogen on capillary zone electrophoresis of canine samples were studied. Solutions of haemoglobin, lipid and bilirubin were prepared and mixed with serum aliquots to make up samples containing different concentrations of the putative interferent substance. In addition, samples of serum and plasma were assayed to assess the influence of fibrinogen. Haemolysis and lipids produced a change in electropherogram morphology giving an interference peak located in the beta-2 region when haemoglobin was increased, and in the alpha-2 region when lipids were increased. A rise in concentration of these interferents caused an increase in the beta and alpha-2 fractions respectively, and a decrease in the other fractions. Bilirubin did not alter morphology but gave an increase in the albumin and alpha-1 and a decrease in the alpha-2 and beta-2 fractions. No differences were found between serum and plasma samples, and fibrinogen did not produce any additional peak.