Phase II study of gefitinib for non-small cell lung cancer (NSCLC) patients with epidermal growth factor receptor (EGFR) gene mutations detected by PNA-LNA PCR clamp

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Background: The responsiveness to gefitinib has been reported to closely link to the presence of EGFR gene mutations. We developed a method, PNA-LNA PCR clamp, capable of detecting EGFR mutations in the presence of 100-fold background of wild type EGFR from normal cells (Can Res. 2005;65:7276). This study was prospectively designed to evaluate 1) the sensitivity and the specificity of the PNA-LNA PCR clamp (sample size > 100 pts) and 2) a phase II study of gefitinib for NSCLC patients (pts) with EGFR gene mutations (sample size > 25 pts to show the lower limit of 95% CI > 50%). Methods: Clinical samples (sputum, pleural effusion, bronchial fluid and paraffin tissue) were obtained from consecutive NSCLC pts with informed consent in our institution, and were tested by the PNA-LNA PCR clamp. After the second informed consent, for PS 0–2, inoperable stage III and IV pts with EGFR mutations, gefitinib (250mg P.O. daily) was given as the second treatment after docetaxel containing chemotherapy. In case of poor PS pts, the first line chemotherapy was omitted. Results: From Sept. ’04 to Oct. ’05, samples from 100 of a total of 107 pts were informative of EGFR mutation status. PNA-LNA PCR clamp detected EGFR mutations in 38 pts (38%) (15 males/23 females; median age:62; adenoca.:33 pts). Exon 19 deletions, L858R and L861Q were found in 25 (66%), 12 (32%) and 1 (2%) patients, respectively. But 62 pts (51 males/11 females; median age:66; Ad:43 pts) were judged to have wild type EGFR. Between positive and negative pts in EGFR mutation, there was significant difference in the distinction of sex (p = 0.00001). Gefitinib was given to 26 pts with EGFR mutations as the first line (4 pts) or the second line treatment (22 pts). One patient and 20 patients showed CR and PRs, respectively, and the response rate was 81% (95% CI: 61–94%). For patients with wild EGFR genes, gefitinib was given to 5 patients and one patient (20%) showed PR. The response rate was significantly different between wild and mutant EGFR genes detected by the PNA-LNA PCR clamp (p = 0.017). Conclusions: PNA-LNA PCR clamp could reliably detect EGFR mutations, indicating the method is useful to detect EGFR mutations in clinical specimens. Updated data will be presented at the meeting.

No significant financial relationships to disclose.

Significant correlations between the flow volume of patent ductus venosus and early neonatal liver function: possible involvement of patent ductus venosus in postnatal liver function

BACKGROUND

The biochemical features of portosystemic venous shunt with high flow volume are hypergalactosaemia, hyperammonaemia, prolonged blood coagulation time, and raised serum bile acid concentration. The ductus venosus remains open with shunt flow in most neonates for a certain period after birth. However, the effects of blood flow through the ductus venosus on neonatal liver function remain unclear.

OBJECTIVE

To elucidate the effect of patency of the ductus venosus on liver function in early neonates.

METHODS

Subjects were divided into three groups by gestational age (group I, 29-32 weeks; group II, 33-36 weeks; group III, 37-41 weeks). The shunt flow volume through the ductus venosus was examined serially using ultrasonography, and correlations between flow volume and liver function in the respective groups were calculated during the first week after birth.

RESULTS

Group I had a higher flow volume and later functional closure than the other two groups. Plasma ammonia and serum total bile acid concentrations correlated with flow volume in groups I and II, and blood galactose and galactose 1-phosphate concentrations correlated significantly with flow volume in group III. Percentage hepaplastin also correlated significantly with flow volume in all groups, but plasma vitamin K concentration did not in any group.

CONCLUSIONS

Patent ductus venosus has a considerable effect on crucial liver functions such as ammonia detoxification, blood coagulation, and regulation of serum total bile acid concentration in early neonates.

Central tegmental tract involvement in an infant with 6-pyruvoyltetrahydropterin synthetase deficiency

We report the case of an asymptomatic 2-month-old infant with 6-pyruvoyltetrahydropterin synthetase deficiency detected through a neonatal phenylketonuria screening program. MR imaging revealed symmetrical lesions in the central tegmental tract with reduced diffusion, which resolved after treatment. A possible explanation for these lesions is intramyelinic edema resulting from brain insults in utero.

Can modulating corticotropin releasing hormone receptors alter visceral sensitivity?

Activation of corticotropin releasing hormone (CRH) receptor 2 (CRH-R2) reduces visceral sensitivity induced by colorectal distension in conscious rats. This finding is relevant to the increased interest in the potential use of therapeutic agents that act on CRH receptors in the treatment of irritable bowel syndrome.

Classical conditioned response of rectosigmoid motility and regional cerebral activity in humans

The relationship between the central processes of classical conditioning and conditioned responses of the gastrointestinal function is incompletely understood in humans. We tested the hypothesis that the rectosigmoid motility becomes conditioned with anticipatory painful somatosensory stimulus and that characteristic brain areas become activated during anticipation. In nine right-handed healthy male subjects, a loud buzzer (CS, conditional stimulus) was paired with painful transcutaneus electrical nerve stimulation to the right hand (unconditional stimulus). Rectosigmoid muscle tone measured by the barostat as the intrabag volume, phasic contractions of the bowel measured as the number of phasic volume events (PVEs), and regional cerebral blood flow assessed by positron emission tomography (PET), were measured before and after conditioning. Following conditional trials, the bag volume after CS alone did not show significant changes between before and after the stimulus, but the number of PVEs after 2-minute interval of the CS alone was significantly greater than that before the stimulus (P < 0.05). The PET data showed the conditioning elicited significant cerebral activation of the prefrontal, anterior cingulate, parietal and insula cortices (P < or = 0.001, uncorrected). Rectosigmoid motility can be conditioned with increase in phasic contractions in humans.

The LET spectra at different penetration depths along secondary9C and11C beams

Owing to the potentially therapeutic enhancement of delayed particles in treating malignant diseases by radioactive 9C-ion beam, LET spectra at different penetration depths for a 9C beam with 5% momentum spread, produced in the secondary beam line (SBL) at HIMAC, were measured with a multi-wire parallel-plate proportional counter. To compare these LET spectra with those of a therapeutic 12C beam under similar conditions, the 12C beam was replaced with an 11C beam, yielded in the SBL as well and having almost the same range as that of the 9C beam. The LET spectra of the 9C beam and its counterpart, i.e. the 11C beam, at various depths were compared, especially around the Bragg peak regions. The results show that nearby the Bragg peak lower LET components decreased in the LET spectra of the 9C beam while extra components between the LET peak caused by the primary beam and the lower components due to the fragments could be observed. These additional contributions in the LET spectra could be attributed to parts of the emitted particles from the radioactive 9C ions with suitable conditions regarding the LET counter. Integrating these LET spectra in different manners, depth-dose and dose-averaged LET distributions were obtained for the 9C and 11C beams, forming the basic data sets for further studies. In general, the depth-dose distributions of the 9C and 11C beams are comparative, i.e. almost the same peak-to-plateau ratio. The ratio for the 9C beam, however, has room to increase due to the geometric structure limitation of the present detector. The dose-averaged LETs along the beam penetration are always lower for the 9C beam than for the 11C beam except at the falloff region beyond the Bragg peak. Applying the present depth-dose and dose-averaged LET data sets as well as the essential radiobiological parameters obtained with 12C beams previously for HSG cells, an estimate concerning the HSG cell surviving effects along the penetration of the 9C and 11C beams shows that lower survival fractions for the 9C beam at the distal part of the Bragg peak, corresponding to the stopping region of the incoming 9C ions, can be expected when the same entrance dose is given. It is still hard to appreciate the potential of 9C beams in cancer therapy based on the present LET spectrum measurement, but it provides a substantial basis for upcoming radiobiological experiments.

Brain activity during distention of the descending colon in humans

Brain-gut interaction is considered to be a major factor in the pathophysiology of irritable bowel syndrome. However, only limited information has been provided on the influence of gastrointestinal tract stimulation on the brain. Our aim in this study was to determine the specific regions of the brain that are responsible for visceral perception and emotion provoked by distention of the descending colon in humans. Fifteen healthy males aged 22 +/- 1 participated in this study. Using a colonoscope, a balloon was inserted into the descending colon of each subject. After sham stimulation, the colon was randomly stimulated with bag pressures of 20 and 40 mmHg, and regional cerebral blood flow was measured by [(15)O] positron emission tomography. The subjects were asked to report visceral perception and emotion using an ordinate scale of 0-10. Colonic distention pressure dependently induced visceral perception and emotion, which significantly correlated with activation of specific regions of the brain including the prefrontal, anterior cingulate, parietal cortices, insula, pons, and the cerebellum. In conclusion, distention of the descending colon induces visceral perception and emotion. These changes significantly correlate with activation of specific regions in the brain including the limbic system and the association cortex, especially the prefrontal cortex.

[Pharmacological and pharmacokinetic features and clinical effects of pitavastatin (Livalo Tablet)]

Today 3-hydroxy-3-methylglutaryl-coenzyme A (HMG-CoA) reductase inhibitors (statins) are the most often prescribed drugs among the therapeutics for hypercholesterolemia. Pitavastatin is a novel statin that has been developed entirely in Japan from the biological screening to clinical studies persuing more efficatious statin than hitherto known. Preclinical studies on drug metabolism revealed that pitavastatin is distributed selectively to the liver, excreted into bile without metabolic modification, and efficiently re-circulates to the liver to show a prolonged plasma half-life. In guinea pigs, pitavastatin enhanced hepatic LDL receptor activity and reduced VLDL secretion in a liver perfusion study, and it lowered plasma total cholesterol (TC) levels at 0.3 mg/kg and triglyceride (TG) levels at 1 mg/kg, respectively, and more. From these results, pitavastatin is assumed to lower LDL cholesterol (LDL-C) by promoting LDL receptor expression and further potentiate the cholesterol-lowering effect and exert TG-lowering effect by reducing VLDL secretion. (14)C-Pitavastatin is metabolized with CYP2C9 to 8-hydroxy derivative, but its Vmax /Km was about 2 micro l/min/mg, about 1/8 to 1/100 in comparison to the reported values of other statins, indicating that pitavastatin is hardly metabolized. Also, other human P450 species were not inhibited by pitavastatin. Therefore, pitavastatin is considered to have little interaction with drugs through P450. In the summarized clinical results with 862 patients, pitavastatin lowered TC and LDL-C by 28% and 40%, respectively. There was no difference in the frequency of side effects and no serious adverse effect was observed for pitavastatin. Pitavastatin possesses superior plasma lipid-improving effects, induces little drug interaction, and is expected to make a good contribution to the medication of hypercholesterolemia.

Flow cytometric detection of cell-associated interleukin-8 in alveolar macrophages in vivo from patients with hypersensitivity pneumonitis and sarcoidosis

In comparison with neutrophil-mediated lung diseases, such as acute respiratory distress syndrome, the involvement of IL-8 in lymphocyte-mediated lung diseases has not been fully investigated. Several reports have shown a slight increase in bronchoalveolar lavage fluid (BALF) IL-8 in patients with hypersensitivity pneumonitis (HP) and sarcoidosis (SAR), but the source of the IL-8 has not been clarified. In the present study, the in vivo production of IL-8 by alveolar macrophages (AMs) is examined in these patients by analyzing the cell-associated IL-8, using the flow cytometric method adopted previously. The IL-8 levels in the epithelial lining fluid (ELF) were also assessed. Initially, slight, but significant, increased levels of ELF IL-8 in HP and SAR were confirmed. Using flow cytometric analysis, a significant increase was found in the cell-associated IL-8 of the freshly isolated AMs in HP, but not in SAR, indicating in vivo production of IL-8 by AMs in HP. The cell-associated IL-8 of the AMs cultured with or without lipopolysaccharide was also analyzed. However, in contrast to previous findings in patients with idiopathic pulmonary fibrosis, no differences were found between SAR and HP patients and control subjects. Based on these findings, it is speculated that ELF IL-8 levels are slightly increased in HP and SAR, and they may contribute to the accumulation of neutrophils and possibly lymphocytes. However, the source of IL-8 may be different and AMs are the candidate source of IL-8 in HP, but not in SAR. The flow cytometric method may be useful in assessing cytokines production by AMs.

Washout measurement of radioisotope implanted by radioactive beams in the rabbit

Washout of 10C and 11C implanted by radioactive beams in brain and thigh muscle of rabbits was studied. The biological washout effect in a living body is important in the range verification system or three-dimensional volume imaging in heavy ion therapy. Positron emitter beams were implanted in the rabbit and the annihilation gamma-rays were measured by an in situ positron camera which consisted of a pair of scintillation cameras set on either side of the target. The ROI (region of interest) was set as a two-dimensional position distribution and the time-activity curve of the ROI was measured. Experiments were done under two conditions: live and dead. By comparing the two sets of measurement data, it was deduced that there are at least three components in the washout process. Time-activity curves of both brain and thigh muscle were clearly explained by the three-component model analysis. The three components ratios (and washout half-lives) were 35% (2.0 s), 30% (140 s) and 35% (10 191 s) for brain and 30% (10 s), 19% (195 s) and 52% (3175 s) for thigh muscle. The washout effect must be taken into account for the verification of treatment plans by means of positron camera measurements.

Washout studies of 11C in rabbit thigh muscle implanted by secondary beams of HIMAC

Heavy ion therapy has two definite advantages: good dose localization and higher biological effect. Range calculation of the heavy ions is an important factor in treatment planning. X-ray CT numbers are used to estimate the heavy ion range by looking up values in a conversion table which relates empirically photon attenuation in tissues to particle stopping power; this is one source of uncertainty in the treatment planning. Use of positron emitting radioactive beams along with a positron emission tomograph or a positron camera gives range information and may be used as a means of checking in heavy ion treatment planning. However, the metabolism of the implanted positron emitters in a living object is unpredictable because the chemical forms of these emitters are unknown and the metabolism is dependent on the organ species and may be influenced by many factors such as blood flow rate and fluid components present. In this paper, the washout rate of 11C activity implanted by injecting energetic 11C beams into thigh muscle of a rear leg of a rabbit is presented. The washout was found to consist of two components, the shorter one was about 4.2 +/- 1.1 min and the longer one ranged from 91 to 124 min. About one third of the implanted beta+ activity can be used for imaging and the rest was washed out of the target area.

The effect of head posture on the pharyngeal airway space (PAS)

The purpose of this study was to investigate the relationship between cranio-cervical inclination and pharyngeal airway space (PAS) by measuring these parameters at different head postures in the same subjects and to obtain a regression equation to correct the values measured. Fifty lateral cephalometric radiographs taken at five different head postures per individual were obtained from ten adults (seven males and three females) aged from 25 to 30 years with nose breathers and Class I occlusion. The changes in cranio-cervical inclination produced by head extension were correlated with changes in the variables describing the PAS. The OPT/NSL (cranio-cervical inclination in the second vertebrae) and C3-Me (distance between the third vertebrae and the Menton) correlated strongly with PAS-TP (the most proximal distance measured between the posterior pharyngeal wall and the tongue base) in the pharyngeal airway space (r = 0.807 and 0.854 respectively). The regression equations were Y = - 27.177+0.39X (Y = PAS-TP, X = OPT/NSL), and Y = -21.105+0.402X (Y = PAS-TP, X = C3-Me), respectively. From these equations we could conclude that an increase of 10 degrees in OPT/NSL or 10 mm in C3-Me increased the pharyngeal airway space (PAS-TP) by about 4 mm.