Dynamic changes in RAS gene status in circulating tumour DNA: a phase II trial of first-line FOLFOXIRI plus bevacizumab for RAS-mutant metastatic colorectal cancer (JACCRO CC-11).

BACKGROUND: Few prospective studies have used liquid biopsy testing in RAS-mutant metastatic colorectal cancer (mCRC), and its clinical significance remains unknown. Therefore, this study aimed to carry out a biomarker analysis by liquid biopsy using updated data of the phase II trial of FOLFOXIRI plus bevacizumab as first-line chemotherapy for RAS-mutant mCRC. MATERIALS AND METHODS: A total of 64 patients who received modified FOLFOXIRI regimen (irinotecan 150 mg/m2, oxaliplatin 85 mg/m2, levofolinate 200 mg/m2, and fluorouracil 2400 mg/m2) plus bevacizumab biweekly were enrolled. The primary endpoint was the objective response rate (ORR). Plasma samples were collected at pre-treatment, 8 weeks after treatment, and progression in participants included in the biomarker study. The levels of circulating tumour DNA (ctDNA) and specific KRAS and NRAS variants were evaluated using real-time PCR assays. RESULTS: There were 62 patients (median age: 62.5 years, 92% performance status 0, 27% right side) who were assessable for efficacy and 51 for biomarker analysis. ORR was 75.8% (95% confidence interval 65.1% to 86.5%). The median progression-free survival was 12.1 months, and the median overall survival (OS) was 30.2 months. In 78% of patients, RAS mutations disappeared in the ctDNA at 8 weeks after treatment; these patients tended to have better outcomes than those with RAS mutations. Interestingly, RAS mutations remained undetectable during progression in 62% of patients. Survival analysis indicated that the median OS from progression was significantly longer in patients with RAS mutation clearance than in those with RAS mutation in the ctDNA at disease progression (15.1 versus 7.3 months, hazard ratio: 0.21, P = 0.0046). CONCLUSIONS: Our biomarker study demonstrated no RAS mutations in ctDNA at disease progression in 62% of patients with RAS-mutant mCRC. Both OS and post-progression survival were better in patients with clearance of RAS mutations in ctDNA after triplet-based chemotherapy.

Angularly-dispersed optical parametric amplification of optical pulses with one-octave bandwidth toward monocycle regime.

We demonstrated experimentally the generation of 65-microJ, 5.8-fs optical pulses with an ultrabroad bandwidth (540-1000 nm) by the use of a double-pass angularly-dispersed non-collinear optical parametric amplifier. We also confirmed up to the 95-microJ output from the amplifier when seed pulses were not pre-compensated for. Furthermore, we confirmed that the broadband pump pulses brought in the broader gain bandwidth (from 520 to 1080 nm) than numerical estimation based on CW-pump approximation. To the best of our knowledge, this is the system with the broadest gain bandwidth.

Frequency-resolved optical gating of isolated attosecond pulses in the extreme ultraviolet.

The pulse shape and phase of isolated attosecond extreme ultraviolet (XUV) pulses with a duration of 860 asec have been determined simultaneously by using frequency-resolved optical gating based on two-photon above-threshold ionization with 28-eV photons in He. From the detailed characterization, we succeeded in shaping isolated XUV pulses on an attosecond time scale by precise dispersion control with Ar gas density or by changing the driving pulse width. These results offer a novel way to excite and observe an electron motion in atoms and molecules.

Small intestinal metastasis from renal cell carcinoma exhibiting rare findings.

Small intestinal metastasis from renal cell carcinoma (RCC) has only rarely been described. We report two patients who developed small bowel metastases from RCC showing different clinicopathological characteristics. Both patients underwent hemilateral nephrectomy for RCC and developed lung metastases metachronously or simultaneously. One patient developed occlusive ileus caused by multiple polypoid tumours composed of sarcomatoid tissue in the jejunum shortly after nephrectomy. The other patient presented melaena due to bleeding from a Borrmann 2-like tumour in the jejunum six years after nephrectomy. Clinically, his disease was slow-growing. Sarcomatoid histology and Borrmann 2-like tumour in this report are rare findings in metastatic tumour of RCC in the small bowel.

Development of a new membrane-type heated humidifier for laparoscopic surgery.

BACKGROUND: Recently, several animal studies showed that the core body temperature falls during pneumoperitoneum, and this hypothermia could be prevented by using heated and humidified gas insufflation. However, there are no satisfactory heated humidifiers to meet this purpose. Therefore, we developed a new membrane-type heated humidifier. MATERIALS AND METHODS: The newly developed heated humidifier employs an ion-exchange membrane (Nafion: Du Pont Co. Ltd) tube that passes water selectively in molecular form and a gas compartment is completely separated from distilled water to prevent infection. This humidifier consists of a Nafion tube assembly and a case that includes the heater. A perforated protecting tube is located outside the Nafion tube to prevent direct contact with the Nafion tube when it is assembled. The Nafion tube assembly is inserted in the case, and dry gas flows inside of the Nafion tube. The space between the case and the Nafion tube assembly is filled with distilled water. A heater raises the temperature of the distilled water, and heat and water vapor are transferred to cold and dry gas through the Nafion membrane. Four different types of insufflators were involved in this performance comparison study: a Nafion-based heated and humidified insufflator, a conventional heated insufflator, a conventional heated and humidified insufflator, and a conventional cold and dry insufflator. Temperature and relative humidity were measured once each minute for 15 min, which was repeated four times. Each insufflator was operated at two rates of flow: 5 L/min and 10 L/min. RESULTS: Temperature and humidity of the conventional cold and dry insufflator, the Nafion membrane-type heated and humidified insufflator, the conventional heated insufflator, and the conventional heated and humidified insufflator measured at the distal end of circuit reached 22.0 +/- 0.2 degrees C and 0%, 36.7 +/- 1.1 degrees C and 100%, 29.0 +/- 0.4 degrees C and 0%, and 31.3 +/- 0.4 degrees C and 70.5 +/- 5.3% in 15 min at 5 L/min flow rates. At 10 L/min flow rates, temperature and humidity were almost the same as those at 5 L/min. The membrane-type heated humidifier demonstrated statistically significant improvement in both the temperature ( p < 0.0001) and relative humidity ( p < 0.0001) parameters in comparison to the conventional normal, heated, or heated and humidified insufflators at 5 L/min and 10 L/min continuous flow rate in statistics using repeated-measure ANOVA. CONCLUSION: This newly developed heated humidifier offers the great advantages of maintaining intraabdominal temperature and humidity in comparison to conventional insufflators for laparoscopic surgery.

Second-harmonic generation from a KBe(2) BO(3)F(2) crystal in the deep ultraviolet.

By use of KBe(2)BO(3)F(2) (KBBF) crystal with a size of 10 mmx10 mm x1.2 mm and a special prism-coupling technique (PCT), fourth-harmonic generation of Ti:sapphire laser systems from 200 to 179.4 nm has been achieved. Moreover, with a Ti:sapphire laser with a 50-fs pulse duration and a 1-kHz repetition rate, conversion efficiency as high as 13% from 400 to 200 nm without any surface-loss correction has also been obtained. The data show that with the PCT a KBBF crystal can produce deep-UV coherent light with measurable power output.

Generation and focusing of submilliwatt-average-power 50-nm pulses by the fifth harmonic of a KrF laser.

We demonstrate generation and focusing of 49.7-nm pulses with an average power of 0.1 mW at 200 Hz and with a pulse energy of >1 microJ at 10 Hz by the fifth harmonic of a femtosecond KrF laser. The fifth harmonic is selected and focused with a concave Sc/Si multilayer mirror to a diameter of 2microm, resulting in a peak intensity of 0.5 TW/cm(2), which will make extreme-ultraviolet nonlinear optics feasible. A novel single-shot linear in situ method of spot-size measurement by use of self-trapped exciton luminescence is also demonstrated.

Unique action determinants of double acting topoisomerase inhibitor, TAS-103.

O6-methylguanine-DNA methyltransferase (MGMT), gamma-glutamylcysteine synthetase (gamma-GCS), and glutathione (GSH) are found to participate in resistance to TAS-103, a topoisomerase I/II inhibitor. In 13 human cancer cell lines, MGMT expression correlated with IC50 for TAS-103, whereas gamma-GCS expression inversely correlated with the IC50 value, suggesting MGMT may work to decrease TAS-103 activity but gamma-GCS may increase it. A reduced gamma-GCS and GSH, and an increased MGMT were associated with the development of resistance in A549 and DLD cells, and gamma-GCS inhibition by buthionine sulphoximine increased the TAS-103 resistance, whereas MGMT inhibition by both O6-benzyl-guanine and MGMT-antisense transfection sensitized cells to TAS-103.

[Nontuberculous atypical mycobacterial infection with progressive pancytopenia in a patient with myelodysplastic syndrome].

We describe a patient with myelodysplastic syndrome (MDS) who developed disseminated infection due to nontuberculous mycobacteria (NTM). A 64-year-old man was admitted because of persistent fever that had been unresponsive to antibiotics. Bone marrow aspiration specimens showed myelodysplasia (RA), but the origin of the fever was unclear. Cytopenia worsened to a level that required transfusion of red blood cells and platelets. Repeated bone marrow examination revealed hypoplasia with hemophagocytosis. Several weeks later, photochromogenic NTM was isolated from bone marrow specimens, sputum and broncho-alveolar lavage (BAL) fluid which had been obtained on admission. Antituberculosis treatment with clarithromycin markedly improved the patient's general condition and hematological abnormalities. Three months after resolution of the NTM infection, the peripheral blood monocyte count increased, the fever recurred, and the patient suddenly died of myocardial infarction. Disseminated infection with NTM has gained attention as a frequent complication of AIDS, and NTM can also be one of the pathogens causing disseminated infection in patients with MDS. In the present case, infection with mycobacteria that normally would have been digested by macrophages and would not have caused disseminated infection in a healthy individual, was probably related to the clinical features including high fever, severe pancytopenia and hemophagocytosis.

Effect of oesophagectomy on monocyte-induced apoptosis of peripheral blood T lymphocytes.

BACKGROUND: Surgical stress has been reported to induce immunosuppression. The mechanisms giving rise to T-cell dysfunction following surgery are still unclear. The cellular mechanisms behind T-cell dysfunction following surgery were investigated, based on the induction of T-cell apoptosis and downregulation of T-cell signalling molecules. METHODS: Peripheral blood T cells were collected and separated before and after surgery in patients who had oesophagectomy, gastrectomy or cholecystectomy, and studied for their ability to produce cytokines, the induction of T-cell apoptosis with terminal deoxynucleotidyl transferase-mediated dUPT-biotin nick end labelling methods, and the expression of T-cell signalling zeta (TCR zeta) molecules with intracellular staining. RESULTS: The increased degree of T-cell apoptosis, downregulation of TCR zeta molecules and impaired cytokine production of T cells were significant on days 1 and 3 after operation in patients who had oesophagectomy, but not after gastrectomy or cholecystectomy. A higher level of T-cell apoptosis was observed in the co-culture with postoperative monocytes than with preoperative monocytes. CONCLUSION: Peripheral blood T cells obtained after oesophagectomy underwent apoptosis that correlated with the downregulation of TCR zeta molecules. Postoperative monocytes induced by surgical stress were able to mediate the T-cell apoptosis.

Interposed colon between remnants of the small intestine exhibits small bowel features in a patient with short bowel syndrome.

We describe herein the case of a 48-year-old man who underwent emergency massive resection of the small intestine due to a strangulated ileus, which led to short bowel syndrome (SBS), as he was left with only 7 cm of jejunum and 8 cm of ileum with ileocecal valve. He then received interposition of a colon segment between the jejunum and ileum remnants isoperistaltically. For 24 months after the operation, he has been able to tolerate oral intake, but still requires partial home parenteral nutritional support during the night on a bimonthly basis. Biochemical and nutritional parameters, including the analysis of minerals and trace elements, indicated that the patient was in relatively good health. Histological examination revealed that the mucosa of the interposed colon showed hypertrophy and hyperplasia of the crypt glands, and cells resembling Paneth cells which are usually seen in the small intestine, suggesting that the colon segment exhibits adaptive changes to the small intestine. Colon interposition may be a useful technique in patients with SBS when the small bowel is too short for the other surgical considerations.

Gastric cancer with Virchow's and multiple lung metastases showing a remarkable response to preoperative chemotherapy: report of a case.

We report herein a rare case with advanced gastric cancer combined with group 4 lymph node and lung metastases that responded remarkably to neoadjuvant chemotherapy. A 65-year-old man was found to have a well-differentiated type 3 gastric cancer that invaded the duodenum locally and was accompanied with Virchow's, para-aortic lymph nodes, and multiple lung metastases based on physical, endoscopic, and radiological examinations. In addition, his carbohydrate antigen (CA) 19-9 was elevated to 3965U/ml, and CA72-4 to 46U/ml. Prior to surgery, he was treated with 5-fluorouracil (5-FU; 500mg/body per day) and low-dose cisplatinum (CDDP; 10mg/body per day) as neoadjuvant chemotherapy for 6 weeks. As a result, a partial response was obtained in all lesions, and CA19-9 and CA72-4 decreased to 463U/ml and 9.4U/ml, respectively. Four weeks after the completion of neoadjuvant chemotherapy, a distal gastrectomy was performed, and a histopathological examination of the resected specimen showed a grade 2 response to chemotherapy. Immunohistochemically, the thymidylate synthase expression level was very low in the tumor tissues, which might account for the good response to the combination chemotherapy with 5-FU and CDDP observed in the present case.

Beneficial effects of nitric oxide synthase inhibition on the recovery of neurological function after spinal cord injury in rats.

We have demonstrated recently that treatment with N(G)-monomethyl-L-arginine (L-NMMA) accelerates electrophysiological recovery after transient spinal cord ischaemia in anaesthetized cats. To determine whether nitric oxide synthase (NOS) inhibition in the acute phase of spinal cord injury results in better functional recovery in the chronic phase, we evaluated the influence of L-NMMA on the time course of changes of neurological function and the histopathological changes after spinal cord compression in rats. Experimental spinal cord injury was produced in anaesthetized rats by short-term (5 min) compression with a thread placed around the spinal cord at T13. The recovery of motor function was assessed by a treadmill test 10, 20 and 30 days after spinal cord compression. The latency of potentials evoked by hindlimb stimulation was measured at the funiculus posterior at C1 10 days after the spinal cord injury in anaesthetized rats. Histological examinations were also performed at the same time. The compression-induced spinal cord injury resulted in motor dysfunction of hindlimbs, an increase in the latency of the evoked potentials and neuronal degeneration in funiculus posterior at T13. Repeated administration of L-NMMA for 1 day significantly accelerated the recovery of the motor function, shortened the latency of the evoked potentials and attenuated the myelin vacuolization in the spinal cord. These beneficial effects of L-NMMA on neurological function and histopathological changes were abolished by coadministration of L- but not D-arginine. These results suggest that NOS inhibition during the early stage of spinal cord injury has beneficial effects on the recovery of neurological function and the histopathological changes in the chronic stage.

50-W average-power, 480-fs KrF excimer laser with gated gain amplification.

We have developed a 50-W average-power KrF excimer laser with a pulse width of 480 fs by using the method of gated gain amplification at a 200-Hz repetition rate.

Generation of milliwatt narrow-bandwidth vacuum ultraviolet radiation by an all-solid-state tunable high-average-power laser system.

Generation of milliwatt narrow-bandwidth vacuum ultraviolet radiation by two-photon resonant four-wave mixing in Xe at 153 nm is demonstrated. The output of extreme ultraviolet radiation was at the microwatt level at 85 nm. For this demonstration, we developed an all-solid-state tunable 5-kHz Ti:sapphire laser system that produces 0.6-ns 0.7-GHz-bandwidth pulses at an average power of 32 W at the fundamental, 12 W at the second harmonic, and 6.3 W at the third harmonic.

High frequency of c-Met expression in gastric cancers producing alpha- fetoprotein.

Gastric cancers producing alpha-fetoprotein (AFP) have a poor prognosis and a high incidence of liver metastasis. Hepatocyte growth factor (HGF) and its receptor, c-Met, are known to induce mitosis and cell movement and to promote tumor progression. In the present study, c-Met and HGF expression in AFP-producing gastric cancer was compared with those gastric cancers that do not produce AFP. Twenty-six patients with AFP-producing gastric cancers [AFP(+)] and 26 patients stage-matched gastric cancers without AFP production [AFP(-)] were evaluated for c-Met and HGF expression and proliferating cell nuclear antigen-labelling index using immunohistochemical analysis. A higher frequency of c-Met expression was observed in the AFP(+) group than in the AFP(-) group (p < 0.01). A higher expression of c-Met might be one explanation for the poorer prognosis of AFP-producing gastric cancers.

Serum level of HER-2/neu in patients with gastric cancer: correlation with HER-2/neu overexpression in gastric carcinoma tissue.

Serum HER-2/neu (c-erbB-2) levels in patients with gastric cancer were evaluated by an enzyme-linked immunosorbent assay and tissue levels of HER-2/neu in the same cohort were determined by immunohistochemistry. Nine (16%) of 57 gastric carcinomas had an overexpression of HER-2/neu detected immunohistochemically. Of these 9 patients, 6 had elevated serum HER-2/neu levels, while 45 of 48 tissue samples with negative staining exhibited normal serum HER-2/neu levels. These results indicated that overall accuracy, positive predictive value, and negative predictive values of their serum measurements were 89, 67 and 94%, respectively. Serum levels of HER-2/neu were correlated with tissue overexpression of HER-2/neu in patients with gastric cancer.

Caldesmon isoform associated with phenotypic modulation of mesangial cells.

Caldesmon (CaD) is a major calmodulin- and actin-binding protein distributed in smooth muscle cells (SMC) and nonmuscle cells. There are at least two high-molecular-weight CaD (h-CaD) isoforms and four low-molecular-weight CaD (l-CaD) isoforms produced by alternative splicing. Isoformal interconversion is associated with phenotypic modulations of vascular SMC. We investigated the CaD isoform in human and rat glomerular mesangial cells (MC) to characterize the phenotypic changes of MC involved in glomerular diseases. A Western blot analysis and reverse-transcription analysis using exon-specific primers revealed that one l-CaD isoform lacking exons 1, 3b and 4 was predominantly expressed in human cultured MC. The expression of this isoform was markedly enhanced in anti-Thy1.1 nephritis rats and streptozotocin-induced diabetic rats, while little expression was observed in the normal glomerulus. Isoformal interconversion did not occur during the phenotypic changes of MC. These data suggested that the activated MC resembled dedifferentiated SMC in terms of the CaD expression pattern, and that CaD is a useful marker of the phenotypic modulations of MC.