Inhibition of p21 and Akt potentiates SU6656-induced caspase-independent cell death in FRO anaplastic thyroid carcinoma cells

SU6656 is a small-molecule indolinone that selectively inhibits Src family kinase and induces death of cancer cells. The aim of the present study was to investigate the influence of SU6656 on cell survival and to assess the role of p21 and PI3K/Akt signaling in cell survival resulting from SU6656 treatment in anaplastic thyroid carcinoma (ATC) cells. When 8505C, CAL62, and FRO ATC cells were treated with SU6656, the viability of 8505C and CAL62 ATC cells decreased only after treatment with SU6656 at a dosage of 100 μM for 72 h, while the viability of FRO ATC cells decreased after treatment with SU6656 in a concentration- and time-dependent manner. Cell viability was not changed by pretreatment with the broad-spectrum caspase inhibitor z-VAD-fmk. Phospho-Src protein levels were reduced, and p21 protein levels were elevated. Phospho-ERK1/2 protein levels were multiplied without alteration of total ERK1/2, total Akt, and phospho-Akt protein levels. Regarding FRO ATC cells, the decrement of cell viability, the increment of cleaved PARP-1 protein levels, and the decrement of phospho-Src protein levels were shown in p21 siRNA- or LY294002-pretreated cells compared to SU6656-treated control cells. ERK1/2 siRNA transfection did not affect cell viability and protein levels of cleaved PARP-1, p21, and Akt. In conclusion, these results suggest that SU6656 induces caspase-independent death of FRO ATC cells by overcoming the resistance mechanism involving p21 and Akt. Suppression of p21 and Akt enhances the cytotoxic effect of SU6656 in FRO ATC cells.

A retrospective study of clinical outcomes of α-blocker or finasteride monotherapy followed by combination therapy: determination of the period of combination therapy of α-blocker and finasteride

AIMS

We investigated outcomes after discontinuing alpha-blockers or finasteride in patients who initially received combination therapy and compared differences by duration of combination therapy.

METHODS

Patients with international prostate symptom score ≥ 8, serum prostatic-specific antigen (PSA) < 4 ng/ml, prostate volume > 25 cm(3) and combination therapy of alpha-blockers and finasteride for more than 6 months were classified into three groups. Group 1 continued combination therapy; group 2, alpha-blockers monotherapy; and group 3, finasteride monotherapy. All parameters were evaluated before and after changing to monotherapy. Patients who received combination therapy for 6-9 months and those who received combination therapy for longer were comparatively analysed.

RESULTS

Mean age of the 106 patients was 66.9 ± 7.8 years. No significant differences in baseline symptom scores, PSA or prostate volume were found. Following combination therapy, symptom scores, and quality of life (QoL) decreased for all groups. Group 1 maintained decreased PSA and prostate volume, and improved uroflowmetric profiles. No differences in uroflowmetric parameters were found after 6 months. Group 2 maintained improved symptoms, QoL and uroflowmetric profiles, although PSA and prostate volume returned to baseline. Group 3 maintained lowered PSA and prostate volume, whereas Qmax returned to baseline. QoL scores showed no change. Patients who received combination therapy for ≥9 months improved more in symptoms and QoL than those who received shorter combination therapy.

CONCLUSIONS

Discontinuation of alpha-blockers or finasteride after combination therapy for ≥ 6 months maintained improvements in symptoms. The appropriate period of combination therapy was ≥ 9 months.

CCAAT/Enhancer-binding protein-homologous protein sensitizes to SU5416 by modulating p21 and PI3K/Akt signal pathway in FRO anaplastic thyroid carcinoma cells

SU5416, vascular endothelial cell growth factor receptor inhibitor, suppresses hypoxia-induced angiogenesis, growth, proliferation, and metastasis in cancer cells. CCAAT/enhancer-binding protein-homologous protein (CHOP) has pivotal roles in regulation of growth and survival. In the present study, we evaluated the effects of SU5416 on cell survival, p21, and PI3K/Akt signal pathway in FRO anaplastic thyroid carcinoma (ATC) cells. Moreover, we investigated the roles of CHOP in cell survival under condition of SU5416 treatment in FRO ATC cells. After SU5416 treatment, cell viability, PARP-1, and caspase-3 protein levels were not changed. p53 and p27 protein levels decreased while p21 protein levels increased. Phospho-Akt protein levels were not altered. In SU5416-treated situation, cell viability was not different before and after administration of either p21 siRNA or LY294002 whereas it was lessened after co-administration of p21 siRNA and LY294002. Compared to SU5416 treatment alone, cell viability was reduced with CHOP plasmid but it was unchanged with CHOP siRNA. PARP-1 and caspase-3 protein levels with CHOP plasmid were elevated whereas the protein levels with CHOP siRNA were similar. While CHOP plasmid transfection diminished p21 and phospho-Akt protein levels, CHOP siRNA transfection did not alter the protein levels. In conclusion, these results suggest that CHOP may sensitize FRO ATC cells to SU5416 thereby inhibiting cell survival by modulating p21 and PI3K/Akt signal pathway. Furthermore, these findings imply that CHOP may be a possible candidate as the chemosensitizing factor for induction of cytotoxicity in ATC cells exposed to SU5416.

Diagnostic efficacy of gadoxetic acid-enhanced MRI for the detection and characterisation of liver metastases: comparison with multidetector-row CT

OBJECTIVES

We compared the diagnostic performance of gadoxetic acid-enhanced MRI and 16-slice multidetector CT (MDCT) with respect to their abilities to detect hepatic metastases and differentiate hepatic metastases from hepatic cysts and haemangiomas.

METHODS

67 patients with 110 liver metastases (size 0.3-2.5 cm), 33 haemangiomas (size 0.5-1.5 cm) and 17 cysts (size 0.3-1.0 cm) underwent 4-phase MDCT and gadoxetic acid-enhanced MRI, including early dynamic phases, post-contrast T(2) weighted turbo spin echo sequences and 20 min hepatocyte-selective phases. Two observers independently analysed each image in random order. Sensitivity and diagnostic accuracy for lesion detection and differentiation for MDCT and gadoxetic acid-enhanced MRI were calculated using receiver operating characteristic analysis.

RESULTS

For both observers, the Az values of gadoxetic acid-enhanced MRI (mean, 0.982 and 0.981) were significantly higher than the Az values of MDCT (mean, 0.839 and 0.892) (p<0.05) for the detection of metastases and for the differentiation of metastases from haemangiomas and cysts. Sensitivities of gadoxetic acid-enhanced MRI with regard to the detection and characterisation of liver metastases (mean, 96.9% and 96.0%) were significantly higher than those of MDCT (mean, 78.7% and 75.0%) (p<0.05).

CONCLUSION

Gadoxetic acid-enhanced MRI showed higher diagnostic accuracy and sensitivity than did MDCT for the detection of hepatic metastases and for the differentiation between hepatic metastases and hepatic haemangiomas or cysts.

Effects of pregabalin on the activity of glutamate transporter type 3

BACKGROUND

Pregabalin, (S)-3-aminomethyl-5-methyl hexanoic acid, is a ligand for the α2δ subunit (a component of voltage-gated calcium channels) and has analgesic and anticonvulsant properties. Glutamate uptake by glutamate transporters may be a mechanism for these properties. We investigated the effects of pregabalin on the activity of the neuronal glutamate transporter type 3 (EAAT3).

METHODS

EAAT3 was expressed in Xenopus laevis oocytes. Two-electrode voltage clamping was used to record membrane currents before, during, and after applying l-glutamate (30 μM) in the presence or absence of pregabalin. Currents were also measured in oocytes pretreated with a protein kinase C (PKC) activator (phorbol-12-myristate-13-acetate, PMA), PKC inhibitors (chelerythrine or staurosporine), or a phosphatidylinositol-3-kinase (PI3K) inhibitor wortmannin.

RESULTS

The exposure of the oocytes injected with EAAT3 mRNA to serial concentrations of pregabalin (0.06-60 μM) significantly increased their responses to 30 μM l-glutamate. A kinetic study showed that pregabalin significantly increased V(max) without changing K(m). Treatment of oocytes with PMA, pregabalin, or pregabalin plus PMA significantly increased transporter currents vs controls, but treatment with PMA plus pregabalin did not increase the responses further vs PMA or pregabalin alone. In addition, pretreatment of oocytes with two PKC inhibitors (chelerythrine or staurosporine), or inhibitor wortmannin, significantly reduced basal and pregabalin-enhanced EAAT3 activity.

CONCLUSIONS

Pregabalin increased EAAT3 activity and PKC and PI3K were involved. This may explain the analgesic effect of pregabalin in neuropathic pain.

Combination of propofol and remifentanil target-controlled infusion for laryngeal mask airway insertion in children

BACKGROUND

The addition of remifentanil to propofol administration can improve the conditions for insertion of laryngeal mask airways (LMAs). However, the extent to which remifentanil reduces propofol requirements when both drugs are administered concomitantly via target-controlled infusion (TCI) in pediatric patients has not been adequately demonstrated. The purpose of this study was to determine the target concentration of propofol that is required for LMA insertion at three different remifentanil target concentrations (0, 2.5, and 5 ng kg(-1) min(-1)) during TCI in children.

METHODS

A total of 67 children, aged 2 to 12 years, were included, and anesthesia was conducted with TCI of propofol and remifentanil using the STELPUMP program. The children were assigned to three groups in a randomized, double-blind manner: propofol with saline (control group), propofol with 2.5 ng mL(-1) of remifentanil (low-remifentanil group), and propofol with 5.0 ng ml(-1) of remifentanil (high-remifentanil group). The EC(50) of propofol for LMA insertion at each target-concentration of remifentanil was determined using Dixon's up-and-down method, and the EC(50) of propofol in each group was compared using the Kruskal-Wallis ANOVA by rank test.

RESULTS

The EC(50) for propofol was 5.18 mcg mL(-1) in the control group, 4.81 mcg ml(-1) in the low-remifentanil group, and 4.36 mcg mL(-1) in the high-remifentanil group, which was significantly different between the control group and the high-remifentanil group only (P<0.001).

CONCLUSION

A higher target concentration of remifentanil significantly reduced the propofol target concentration for LMA insertion during TCI of both drugs in children, but low concentrations of remifentanil failed to reduce the propofol requirement.

Alpha-lipoic acid inhibits endoplasmic reticulum stress-induced cell death through PI3K/Akt signaling pathway in FRTL5 thyroid cells

Alpha-lipoic acid (ALA) has been shown to modulate cell death via PI3K/Akt signal pathway in various cells. In the present study, the effects of ALA on cell death and PI3K/Akt signal pathway linked to cell death-related proteins during endoplasmic reticulum (ER) stress in FRTL5 thyroid cells were evaluated. In FRTL5 thyroid cells, cell viability increased by ALA pretreatment in tunicamycin (TN)-treated cells. When TN was treated, CCAAT/enhancer-binding protein-homologous protein (CHOP) and Bax protein levels were elevated while Bcl-2 protein levels were reduced. ALA diminished CHOP and Bax protein levels, and augmented Bcl-2 protein levels in TN-treated cells. After exposure to TN, phospho-Akt protein levels were repressed whereas total Akt protein levels were not changed. ALA increased phospho-Akt protein levels but not total Akt protein levels in both non-TN-treated and TN-treated cells. After LY294002 administration in non-TN-treated cells, cell viability was reduced, and CHOP and Bax protein levels were elevated, and Bcl-2 protein levels were reduced. The CHOP, Bcl-2 and Bax protein levels were not different after LY294002 administration in TN-treated cells. LY294002 and wortmannin decreased cell viability, and increased CHOP and Bax protein levels, and decreased Bcl-2 protein levels in ALA-pretreated and TN-treated cells. In conclusion, these results suggest that ER stress may induce cell death by modulating PI3K/Akt signal pathway linked to cell death-related proteins in FRTL5 thyroid cells. Moreover, these findings imply that ALA may ameliorate ER stress-induced cell death by activating PI3K/Akt signal pathway and attenuating changes of cell death-related proteins in FRTL5 thyroid cells.

Effects of all-trans retinoic acid on sodium/iodide symporter and CCAAT/enhancer-binding protein-homologous protein under condition of endoplasmic reticulum stress in FRTL5 thyroid cells

In thyroid cells, the effects of all- TRANS retinoic acid (ATRA) on sodium/iodide symporter (NIS) and CCAAT/enhancer-binding protein-homologous protein (CHOP) under condition of endoplasmic reticulum (ER) stress have not been evaluated. In the present study, the relationships between NIS, CHOP, and p38 MAPK, and the effects of ATRA on NIS and CHOP expression as well as on p38 MAPK activation under condition of ER stress in thyroid cells were investigated. In FRTL5 thyroid cells, NIS mRNA and protein levels decreased following tunicamycin (TN) treatment, while CHOP mRNA and protein levels increased. In addition, while CHOP mRNA levels decreased after administration of tauro-UDCA and siCHOP, NIS mRNA levels were not altered. After pretreatment with SB203580, NIS mRNA levels decreased in non-TN-treated cells but increased in TN-treated cells. In contrast, CHOP mRNA levels decreased in both non-TN-treated and TN-treated cells. Exposure to ATRA decreased NIS mRNA levels in non-TN-treated cells but increased NIS mRNA levels in TN-treated cells. ATRA decreased CHOP mRNA levels in both non-TN-treated and TN-treated cells although the response was significant only in TN-treated cells. Phospho-p38 MAPK protein levels but not total p38 MAPK protein levels increased in TN-treated cells. ATRA attenuated this increase in phopho-p38 MAPK protein levels. In conclusion, our results demonstrate that ER stress may induce reciprocal changes in NIS and CHOP expression via p38 MAPK in FRTL5 thyroid cells, and that ATRA may attenuate ER stress-induced alterations in NIS and CHOP expression by modulating the phosphorylation of p38 MAPK in FRTL5 thyroid cells.

A room-temperature semiconductor spaser operating near 1.5 μm

Room temperature spasing of surface plasmon polaritons at 1.46 μm wavelength has been demonstrated by sandwiching a gold-film plasmonic waveguide between optically pumped InGaAs quantum-well gain media. The spaser exhibits gain narrowing, the expected transverse-magnetic polarization, and mirror feedback provided by cleaved facets in a 1-mm long cavity fabricated with a flip-chip approach. The 1.06-μm pump-threshold of ~60 kW/cm2 is in good agreement with calculations. The architecture is readily adaptable to all-electrical operation on an integrated microchip.

Effect of remifentanil on arterial oxygenation during one-lung ventilation

This study was designed to assess the dose-related effects of remifentanil on arterial oxygenation during one-lung ventilation (OLV) under total intravenous anaesthesia with propofol. A total of 104 patients scheduled for elective lung resection surgery requiring OLV were randomly assigned to one of four groups with a target effect-site concentration (Ce) of remifentanil of 0.5, 1, 2 or 4 ng/ml. Patients were anaesthetized with propofol and remifentanil in 100% oxygen. Arterial blood gas analysis was performed after 15 min of two-lung ventilation (TLV15, baseline) and after 15 and 30 min of OLV (OLV15 and OLV30). Mean arterial oxygen tension (PaO2) decreased significantly at OLV15 and OLV30 compared with baseline in all groups, but was comparable in the four groups at each time point, suggesting that remifentanil infusion with a Ce < or =4 ng/ml can be successfully used for anaesthesia with propofol during OLV in lung surgery without any significant changes in PaO2.

Autonomic changes in preoperative uncomplicated diabetic patients with postural changes

Diabetic autonomic neuropathy is a critical complication frequently encountered in anaesthetic and surgical practice. Power spectral analysis is a noninvasive tool for monitoring frequency analysis of heart rate variability (HRV) and autonomic control of the heart. This study examined HRV changes in preoperative diabetic patients without overt signs of autonomic dysfunction and in matched controls (n=18 per group). HRV values at -15 degrees, 0 degrees, 15 degrees, 45 degrees and sitting positions were compared between groups and for each position. HRV in diabetic patients was lower than in controls at all positions (absolute units). Low-frequency power (normalized units) and the low-frequency/high-frequency ratio increased significantly at 45 degrees and in sitting positions in controls but not in diabetic patients. Pre-existing autonomic derangements in diabetic patients without overt clinical symptoms can be aggravated by high-degree tilting or sitting positions. Consequently, great care should be taken during the intra- and perioperative management of these patients.

A short period of inhalation induction with sevoflurane prevents rocuronium-induced withdrawal in children

BACKGROUND

the aim of this study was to determine whether or not inhalation induction with sevoflurane can prevent the withdrawal movement associated with the injection of rocuronium.

METHODS

a total of 75 pediatric patients were randomly allocated to five groups (S 1.5, 2.0, 2.5, 3.0, and the control group). In the control group (n=15), 2.5% thiopental 5 mg/kg was injected intravenously. Rocuronium 0.4 mg/kg was injected immediately after loss of consciousness. In the S 1.5, 2.0, 2.5, or 3.0 group, rocuronium 0.4 mg/kg was injected at 1.5, 2, 2.5, or 3 min after inhalation induction, respectively, and the withdrawal response was recorded. End-tidal sevoflurane concentrations were recorded at the time of the rocuronium injection. The inhalation time of sevoflurane before rocuronium injection required to provide no withdrawal response in 50% and 95% of patients (IT(50) and IT(95) ) was calculated.

RESULTS

the incidence of withdrawal was 80% (12/15), 71.4% (10/14), 21% (3/14), 0% (0/14), and 0% (0/15) in group C, group S 1.5, group S 2.0, group S 2.5, and group S 3.0, respectively. IT(50) of the rocuronium injection time was 1.7 min (95% CI: 1.5-1.9) and IT(95) was 2.3 min (95% CI: 2.0- 2.9).

CONCLUSIONS

this study demonstrated that inhalation induction with sevoflurane can prevent the withdrawal movement induced by rocuronium in children, and IT(50) and IT(95) for the prevention of movement was 1.7 and 2.3 min, respectively.

Estimation of relative defect densities in InGaN laser diodes by induced absorption of photoexcited carriers

Defects are one of the most important factors influencing the optical properties of groups III-V nitride semiconductor materials and thereby their applicability to light-emitting diodes. In this paper, we demonstrate that it is possible to estimate the presence of defects in InGaN laser diodes by performing pump-probe measurements and observing the induced absorptions. We have confirmed that the induced absorption originates from defects by performing experiments in which the pump intensity is varied. We believe that our method provides a powerful tool for evaluating the optical quality of InGaN materials before processing them into device fabrications.

Assessment of radiation dose for surrounding organs and persons approaching implanted patients upon brachytherapy of prostate cancer with Iridium-192

To assess a proper dose for radiation therapy fitting the typical physical characteristics of male Korean bodies, a mathematical phantom was prepared based on standard Korean male measurements. Upon brachytherapy of prostate cancer by implanting 192Ir into the prostate gland (the source organ), the absorbed dose of the prostate gland and surrounding organs and the expected dose of people within the vicinity were assessed. 192Ir, which has been the radionuclide of choice for prostate cancer brachytherapy, was selected for the simulation. It was assumed that 1 Ci of initial radioactivity would be administered. As a result, 1.28E-02 Gy/Ci was exhibited in the prostate gland of the source organ, and the dose to which persons within the vicinity were exposed was exhibited to be 9.19E-06 Sv at a distance of 30 cm from the front.

Diagnostic efficacy of gadoxetic acid-enhanced MRI in the detection of hepatocellular carcinomas: comparison with gadopentetate dimeglumine

This study compared the efficacy of gadoxetic acid-enhanced MRI and gadopentetate dimeglumine-enhanced MRI in the detection of small hepatocellular carcinoma (HCC). Both MRI techniques were performed on 43 patients with a total of 59 HCCs (size range, 0.5-2.0 cm), with a mean interval between the two MRI studies of 3 days (range, 2-7 days). Two observers reviewed both data sets in consensus. Diagnostic accuracy and sensitivity were evaluated using the alternative-free response receiver operator characteristic (ROC) method. The gadoxetic acid set showed a trend toward increased area under the ROC curve (Az value = 0.958) compared with the gadopentetate dimeglumine set (Az value = 0.927), but the difference was not significant (p = 0.362). The sensitivity of the gadoxetic acid set (n = 51, 86.4%) was significantly higher than that of the gadopentetate dimeglumine set (n = 38, 64.4%) (p = 0.0001). Gadoxetic acid-enhanced MRI is a more sensitive diagnostic tool for detection of HCC than gadopentetate dimeglumine-enhanced MRI.

An integrated surface-plasmon source

A compact and versatile source of coherent surface-plasmon polaritions (SPPs) is demonstrated by end-coupling a laser diode operating at 1.46 microm to a plasmonic waveguide integrated on the same microchip. With an optimized overlap between the spatial-modes of the laser and a planar-stripe waveguide, a high coupling efficiency of approximately 36% is achieved, that computations show could approach approximately 60% with smaller, readily achievable gaps between laser and waveguide. This integrated and electrically-activated source, with an available SPP power limited only by the laser diode, appears ideally suited for directly driving plasmonic circuitry or surface-enhanced sensors.

CPAP of 10 cmH2O during cardiopulmonary bypass followed by an alveolar recruitment manoeuvre does not improve post-bypass oxygenation compared to a recruitment manoeuvre alone in children

This randomised controlled study assessed whether continuous positive airway pressure (CPAP) of 10 cmH2O during cardiopulmonary bypass improves post-bypass oxygenation in children compared with no CPAP during bypass. We studied children with a ventricular septal defect. CPAP of 10 cmH2O was applied during bypass in the CPAP group (n=24), whereas the lungs were left deflated in the control group (n=20). In both groups, an alveolar recruitment maneuver was performed by applying positive pressure of 30 to 40 cmH2O for five seconds before weaning from bypass. Postoperative ventilation had the peak inflation pressure set to produce an expired tidal volume of 8 ml/kg with positive end expiratory pressure of 5 cmH2O. Arterial blood gas and haemodynamic measurements were performed at skin incision, five minutes after weaning from bypass, five minutes after chest closure and four hours after arrival in the intensive care unit. In four children CPAP was discontinued because it adversely affected the operating field. There was no difference in demographic characteristics, haemodynamic data, bypass time and operation time. No difference was observed between the groups with respect to pH, PaO2, P(A-a) DO2, PaCO2, and ETCO2 at each time. Variability in the data was greater than expected, leading to a decrease in the expected power of the study. CPAP at 10 cmH2O during bypass was not found to improve the post-bypass oxygenation as compared with leaving the lung deflated during bypass in children undergoing ventricular septal defect repair who had an alveolar recruitment maneuver at the end of bypass.

Comparison of desaturation and resaturation response times between transmission and reflectance pulse oximeters

BACKGROUND

In general, there is a response time between actual arterial hypoxemia and its detection by pulse oximeters. We compared the desaturation and resaturation response times between two types of pulse oximeters, transmission and reflectance pulse oximeters, to find out which oximeter has a more rapid response time.

METHODS

Thirty-three ASA 1 or 2 patients were enrolled in this study. A transmission pulse oximeter was placed on the index finger and a reflectance pulse oximeter was placed on the forehead and monitored simultaneously. After the induction of general anesthesia without pre-oxygenation, we waited until the oxygen saturation value of any of two pulse oximeters declined to 90%, and then mask ventilation was started with 100% oxygen. Oxygen saturation was recorded at an interval of 2 s during this time.

RESULTS

The desaturation response time of SpO(2) to 95% after apnea was 82.0 s (interquartile range: 67.0-98.5 s) vs. 94.0 s (interquartile range: 84.0-106.5 s) (P<0.001) and SpO(2) to 90% was 94.0 s (interquartile range: 75.5-109.5 s) vs. 100.0 s (interquartile range: 84.5-114.5 s) (P<0.001) in the reflectance and transmission oximeters, respectively. The resaturation response time from mask ventilation to 100% SpO(2) was 23.2+/-5.6 vs. 28.9+/-7.6 s (P<0.001) in the reflectance and transmission oximeters, respectively.

CONCLUSION

In clinical situations in which rapid changes in oxygen saturation are expected, we recommend the forehead reflectance pulse oximeter because it responds more quickly in detecting oxygen desaturation and resaturation compared with the transmission pulse oximeter.

Managing invasive species in the presence of endogenous technological change with uncertainty

This research incorporates the development and adoption of an induced technology under uncertainty into a conceptual dynamic model to more broadly examine efficient policies for mitigating invasive species infestations. We find that under optimal policy, marginal costs of adopting conventional control measures are equal to the sum of the marginal benefits from development and adoption of new technology, as well as the use of conventional control measures. This result implies that a resource allocation designed for controlling invasive species is not adequate when an induced technology is not considered. Our results also reveal that the shadow values associated with the probabilities of developing and then adopting an induced technology increase as the shadow values associated with the stock of an invasive species population increase.

Optimization of trichloroethylene degradation using soluble methane monooxygenase of Methylosinus trichosporium OB3b expressed in recombinant bacteria

By complementing cell-free extracts of Pseudomonas putida F1/pSMMO20 with purified soluble methane monooxygenase (sMMO) components of Methylosinus trichosporium OB3b, the low cloned-gene sMMO activity in the recombinant strain was found to be due to incomplete activity of the hydroxylase component. To address this incomplete activity, additional sMMO-expressing strains were formed by transferring mmo-containing pSMMO20 and pSMMO50 into various bacterial species including pseudomonads and alpha-2 subdivision strains such as methanotrophs, methylotrophs, Agrobacterium tumefaciens A114, and Rhizobium meliloti 102F34 (11 new strains screened); sMMO activity was detected in the last two strains. To increase plasmid segregational stability, the hok/sok locus originally from Escherichia coli plasmid R1 was inserted downstream of the mmo locus of pSMMO20 (resulting in pSMMO40) and found to enhance plasmid stability in P. putida F1 and R. meliloti 102F34 (first report of hok/sok in Rhizobium). To further increase sMMO activity, a modified Whittenbury minimal medium was selected from various minimal and complex media based on trichloroethylene (TCE) degradation and growth rates and was improved by removing the sMMO-inhibiting metal ions [Cu(II), Ni(II), and Zn(II)] and chloramphenicol from the medium and by supplementing with an iron source (3.6 microM of ferrous ammonium sulfate). Using chemostat-grown P. putida F1/pSMMO40, it was found that sMMO activity was higher for cells grown at higher dilution rates. These optimization efforts resulted in a twofold increase in the extent of TCE degradation and more consistent sMMO activity.

Practical anatomic landmarks for determining the insertion depth of central venous catheter in paediatric patients

BACKGROUND

Various methods have been recommended to decide a proper insertion depth of central venous catheter (CVC). The carina is recommended as a useful target level for the CVC tip position. We evaluated the sternal head of a right clavicle and the nipples as anatomic landmarks for determining the optimal depth of CVC in paediatric patients.

METHODS

Ninety children, <5 yr, undergoing catheterization through the right internal jugular vein were enrolled. The insertion depth was determined as follows. The insertion point was designated as 'Point I'. The sternal head of the right clavicle was called 'Point A' and the midpoint of the perpendicular line drawn from Point A to the line connecting both nipples was called 'Point B'. The insertion depth of CVC was determined by adding the two distances (from I to A and from A to B) and subtracting 0.5 cm from this. A chest radiography was taken and the distance of the CVC tip from the carina level was measured by the Picture Archiving and Communicating System.

RESULTS

The mean distance of the CVC tip from the carina level was 0.1 (1.0) (P=0.293) cm above the carina (95% CI 0.1 cm below the carina-0.3 cm above the carina). There was no specific relationship between the distance of the CVC tip from the carina level and the patients' age, height, and weight.

CONCLUSIONS

The CVC tip could be placed near the carina by using the external landmarks without any formulae, images, and devices in children in our study.

Detection of small hepatocellular carcinoma: comparison of conventional gadolinium-enhanced MRI with gadolinium-enhanced MRI after the administration of ferucarbotran

We compared the diagnostic efficacy of gadolinium (Gd)-enhanced MRI with that of Gd-enhanced MRI after administration of ferucarbotran for revealing small hypervascular hepatocellular carcinomas (HCCs). 24 patients with 34 HCCs (ranging in size from 0.6-2.0 cm) underwent Gd-enhanced three-dimensional dynamic MRI followed, after an interval of 5-11 days (mean, 7 days), by Gd-enhanced three-dimensional dynamic MRI after administration of ferucarbotran. The two Gd-enhanced arterial-phase MRI scans were compared quantitatively by measuring the tumour-liver contrast-to-noise ratio (CNR) and qualitatively by evaluating the tumour-liver contrast using matched-pairs analysis. The tumour-liver CNR with Gd-enhanced arterial-phase imaging after ferucarbotran (250.3 +/- 103.7) was higher than that with Gd-enhanced arterial-phase imaging (221.1 +/- 96.1) (p < 0.001). Matched-pairs analysis indicated that, for three lesions, the relative tumour-liver contrast was slightly better with Gd-enhanced arterial-phase imaging after ferucarbotran than with conventional Gd-enhanced arterial-phase imaging; however, in the case of the remaining 31 lesions, the two images were equivalent. We concluded that, although Gd-enhanced arterial-phase imaging after ferucarbotran results in better tumour-liver CNR than Gd-enhanced arterial-phase imaging, the ability of the two techniques to reveal small hypervascular HCCs is the same.

GlideScope video laryngoscope: a randomized clinical trial in 203 paediatric patients

BACKGROUND

The GlideScope intubating device has been reported to provide a comparable or superior laryngoscopic view compared with direct laryngoscopy in adults. This study compared the use of the GlideScope with direct laryngoscopy for the laryngoscopic view and intubation time in children.

METHODS

The laryngoscopic view in 203 children was scored using both the Macintosh laryngoscope and the GlideScope using Cormack and Lehane (C&L) grades. After scoring each laryngoscopic view with and without BURP, the patients were randomly allocated to two groups. The trachea was intubated using direct laryngoscopy (Group DL, n=100) or the GlideScope (Group GS, n=103). We compared C&L grades for the two views in the same patient, and also the time to intubate for each group.

RESULTS

The GlideScope improved the view without BURP in the patients with C&L grade 2 (16/26, P<0.01) and with C&L grades 3 and 4 (7/11, P<0.05). The view with BURP was also improved by the GlideScope in C&L grade 2 (4/9, P<0.05) and with C&L grades 3 and 4 (4/5, P=0.059). The mean time for tracheal intubation was 36.0 (17.9) s in the GS group and 23.8 (13.9) s in the DL group (P<0.001).

CONCLUSIONS

In children, the GlideScope provided a laryngoscopic view equal to or better than that of direct laryngoscopy but required a longer time for intubation.