Comparison of post-hepatectomy long-term survival outcome between non-colorectal non-neuroendocrine and colorectal liver metastases: A population-based propensity-score matching analysis

BACKGROUND

Hepatectomy is an established treatment for colorectal liver metastasis (CLM) or neuroendocrine liver metastasis. However, its role in non-colorectal non-neuroendocrine liver metastasis (NCNNLM) is controversial. This study aims to compare long-term survival outcomes after hepatectomy between NCNNLM and CLM in a population-based cohort.

METHODS

From 2009 to 2018, curative hepatectomy were performed in 964 patients with NCNNLM (n ​= ​133) or CLM (n ​= ​831). Propensity score (PS) matching was performed. Short-term and long-term outcomes were compared between PS-matched groups. Univariate and multivariate analyses were performed to identify prognostic factors affecting survival.

RESULTS

There were 133 patients in the NCNNLM group and 266 patients in the CLM group. The mortality (1.5 ​% vs 1.5 ​%) and morbidity (19.5 ​% vs 20.3 ​%) rates were comparable between the two groups. There was no statistically significant difference in 5-year overall (48.9 ​% vs 39.8 ​%) and recurrence-free (25.1 ​% vs 23.4 ​%) survival rates between NCNNLM and CLM groups. A high pre-operative serum bilirubin level, severe postoperative complications and multiple tumors were independent prognostic factors for poor survival.

CONCLUSION

Hepatectomy for selected patients with NCNNLM can achieve similar long-term oncological outcomes as those with CLM. High serum bilirubin, severe postoperative complication and multiple tumors are poor prognostic factors for survival.

Comparison of clinical outcome between laparoscopic and open hepatectomy of high difficulty score for hepatocellular carcinoma: a propensity score analysis

BACKGROUND

Laparoscopic liver resection (LLR) of high difficulty score is technically challenging. There is a lack of clinical evidence to support its applicability in terms of the long-term survival benefits. This study aims to compare clinical outcomes between LLR and the open liver resection of high difficulty score for hepatocellular carcinoma (HCC).

MATERIALS AND METHODS

From 2010 to 2020, using Iwate criteria, 424 patients underwent liver resection of high difficulty score by the laparoscopic (n = 65) or open (n = 359) approach. Propensity score (PS) matching was performed between the two groups. Short-term and long-term outcomes were compared between PS-matched groups. Univariate and multivariate analyses were performed to identify prognostic factors affecting survival.

RESULTS

The laparoscopic group had significantly fewer severe complications (3% vs. 10.8%), and shorter median hospital stays (6 days vs. 8 days) than the open group. Meanwhile, the long-term oncological outcomes were comparable between the two groups, in terms of the tumor recurrence rate (40% vs. 46.1%), the 5-year overall survival rate (75.4% vs. 76.2%), and the 5-year recurrence-free survival rate (50.3% vs. 53.5%). The high preoperative serum alpha-fetoprotein level, multiple tumors, and severe postoperative complications were the independent poor prognostic factors associated with worse overall survival. The surgical approach (Laparoscopic vs. Open) did not influence the survival.

CONCLUSION

LLR of high difficulty score for selected patients with HCC has better short-term outcomes than the open approach. More importantly, it can achieve similar long-term survival outcomes as the open approach.

Laparoscopic vs open liver re-resection for cirrhotic patients with post-hepatectomy hepatocellular carcinoma recurrence: A comparative study

BACKGROUND

Repeated liver resection is an effective treatment for recurrent hepatocellular carcinoma (HCC). However, few studies have compared the outcome of laparoscopic repeat hepatectomy (LRH) and open repeat hepatectomy (ORH) for recurrent HCC, and few of those have included cirrhotic patients.

AIM

To compare short-term and long-term outcomes of cirrhotic patients with LRH and ORH for recurrent HCC.

METHODS

We retrospectively analysed the clinical records retrieved from a prospectively collected database of all patients who underwent hepatectomy for post-hepatectomy recurrent HCC at our institute between May 2006 and June 2021. Cases of recurrent HCCs larger than 7 cm were excluded. Patient demographics, operative details, perioperative outcomes, pathologic details, disease-free survival (DFS), and overall survival (OS) data of LRH and ORH were compared.

RESULTS

Data from 29 patients with LRH and 22 with ORH were compared. The LRH group showed significantly better outcomes for blood loss (median 300 mL vs 750 mL, P = 0.013) and length of hospital stay (median 5 d vs 7 d, P = 0.003). The 1-, 3- and 5-year OS rates in the LRH group were 100.0%, 60.0% and 30.0%, respectively; the corresponding rates in the ORH group were 81.8%, 36.4% and 18.2% (P = 0.336). The 1-, 3- and 5-year DFS rates in the LRH group were 68.2%, 27.3% and 4.5%, respectively; the corresponding rates in the ORH group were 31.3%, 6.3% and 6.3% (P = 0.055). There were no significant differences in overall and DFS between the two groups.

CONCLUSION

Laparoscopic re-resection should be considered for patients presenting with recurrent HCC less than or equal to 7 cm after previous hepatectomy.

Prognostic factors of survival and a new scoring system for liver resection of colorectal liver metastasis

BACKGROUND

Hepatic resection has become the preferred treatment of choice for colorectal liver metastasis (CLM) patients.

AIM

To identify the prognostic factors and to formulate a new scoring system for management of CLM.

METHODS

Clinicopathologic and long-term survival data were analyzed to identify the significant predictors of survival by univariate and multivariate analyses with the Cox model. A clinical score was constructed based on the analysis results.

RESULTS

Three factors of worse overall survival were identified in the multivariate analysis. They were number of liver metastases ≥ 5, size of the largest liver lesion ≥ 4 cm, and the presence of nodal metastasis from the primary tumor. These three factors were chosen as criteria for a clinical risk score for overall survival. The clinical score highly correlated with median overall survival and 5-year survival (P = 0.002).

CONCLUSION

Priority over surgical resection should be given to the lowest score groups, and alternative oncological treatment should be considered in patients with the highest score.

Long-term survival outcome of laparoscopic liver resection for hepatocellular carcinoma

Long-term survival is the most important outcome measurement of a curative oncological treatment. For hepatocellular carcinoma (HCC), the long-term disease-free and overall survival of laparoscopic liver resection (LLR) is shown to be non-inferior to the current standard of open liver resection (OLR). Some studies have reported a superior long-term oncological outcome in LLR when compared to OLR. It has been argued that improvement of visualization and instrumentation and reduced operative blood loss and perioperative blood transfusion may contribute to reduced risk of postoperative tumor recurrence. On the other hand, since most of the comparative studies of the oncological outcomes of LLR and OLR for HCC are non-randomized, it remained inconclusive as to whether LLR confers additional survival benefit compared to OLR. Despite the paucity of level 1 evidence, the practice of LLR for HCC has gained wide-spread acceptance due to the reproducible improvements in the perioperative outcomes and non-inferior oncological outcomes demonstrated by large-scaled, matched comparative studies. Meta-analyses of the outcomes of these studies by multiple systematic reviews have also returned noncontradictory conclusions. On the basis of a theoretical advantage of LLR over OLR in preventing tumor recurrence, the current review aims to dissect from the current meta-analyses and comparative studies any evidence of such superiority.

Laparoscopic hepatectomy versus open hepatectomy for hepatocellular carcinoma: A propensity case-matched analysis of the long-term survival

Backgrounds/Aims

Despite the widespread popularity of laparoscopic surgery, laparoscopic liver resection (LLR) remains in evolution. This study aimed to compare the long-term outcomes for patients undergoing laparoscopic versus open hepatectomy for hepatocellular carcinoma (HCC) ≤7 cm.

Methods

Patients diagnosed with HCC treated by hepatectomy from October 2000 to May 2019 were included. Excluding tumors larger than 7 cm, 1:2 propensity score matching was performed between laparoscopic and open hepatectomies. The perioperative outcomes, 5-year overall survival (OS) and disease-free survival (DFS) of the two groups were compared.

Results

Forty-five patients who underwent LLR were matched to 90 open hepatectomy (OH) during the same period. LLR group had shorter median hospital stay (5 days vs. 9 days, p=0.00) but required longer operative time (326.0 minutes vs. 272.5 minutes, p=0.018) than the OH group. The 5-year overall survival was better in the LLR group (84.9% vs. 61.1%; p=0.036), though there was no significant difference in the 5-year disease free survival (20.0% vs. 22.2%, p=0.613). The rate of R0 resection was comparable between the 2 groups with a slightly better margin distance in the LLR (5 mm vs. 3 mm, p=0.043).

Conclusions

Laparoscopic liver resection is safe and feasible for cirrhotic patients with HCC size up to 7 cm. It has better short-term outcomes and comparable perioperative blood loss and complication rates. The resection margin is not jeopardized and the 5-year overall and disease-free survivals are comparable with the open group.

Pure laparoscopic liver resection versus percutaneous radiofrequency ablation for small hepatocellular carcinoma: a propensity score and multivariate analysis

Background

Methods

Results

Conclusions

Emergency attendances and hospitalisations for complications after transrectal ultrasound-guided prostate biopsies: a five-year retrospective multicentre study

INTRODUCTION

Transrectal ultrasound-guided (TRUS) prostate biopsy is an established procedure for diagnosis of prostate cancer. Complications after TRUS biopsy are not well reported in Hong Kong. This study evaluated the 5-year incidences of TRUS biopsy complications and potential risk factors for those complications.

METHODS

This was a retrospective review of biopsies performed from 2013 to 2017 in two local hospitals, using data retrieved from electronic medical records. The primary outcome was the occurrence of complications requiring either emergency attendances or hospitalisations within 30 days after biopsy. Potential risk factors were examined using multiple logistic regression analysis.

RESULTS

In total, 1699 men were included (mean age ± standard deviation: 67 ± 7 years; median prostate-specific antigen level: 7.9 μg/L [interquartile range, 5.5-12.6 μg/L]); 4.3% had pre-biopsy bacteriuria. Overall, 5.7% and 3.8% of post-biopsy complications required emergency attendances and hospitalisations, respectively. Gross haematuria and rectal bleeding requiring emergency attendances developed in 2.1% and 0.4% of men; 0.8% and 0.4% required hospitalisations. Furthermore, 1.5% of men developed acute urinary retention requiring hospitalisations; 1.9% and 1.2% had post-biopsy infections requiring emergency attendances and hospitalisations, respectively, and 0.9% had urosepsis requiring hospitalisations. Prostate volume >48 cc was associated with an increased risk of post-biopsy retention (odds ratio 2.75, 95% confidence interval: 1.23-4.17).

CONCLUSIONS

The rate of overall complications after TRUS biopsy was low. The most common complications requiring emergency attendances and hospitalisations were gross haematuria and acute urinary retention, respectively. Prostate volume >48 cc increased the risk of post-biopsy urinary retention.

Initial results of selective renal parenchymal clamping with an adjustable kidney clamp in nephron-sparing surgery: an easy way to minimise renal ischaemia

INTRODUCTION

A renal parenchymal clamp has been used at our centre since March 2012. It is used in position over the kidney to achieve optimal vascular control of a tumour while minimising parenchymal ischaemia. This study aimed to report the feasibility, surgical outcome, and oncological control of a kidney clamp in partial nephrectomy.

METHODS

This study was conducted at a teaching hospital in Hong Kong. Partial nephrectomies performed from January 2009 to March 2015 were reviewed. The tumour characteristics and surgical outcomes of kidney clamp were studied and compared with traditional hilar clamping.

RESULTS

A total of 92 patients were identified during the study period. Kidney clamps were used in 20 patients and hilar clamping in 72, with a mean follow-up of 27 and 37 months, respectively. For patients in whom a kidney clamp was applied, all tumours were exophytic to a different extent and the majority (90%) were located at the polar region. The PADUA (preoperative aspects and dimensions used for an anatomical) classification nephrometry score was also lower than those in whom hilar clamping was used (7.07 vs 8.34; P=0.002). The clamp was used in open, laparoscopic, and robot-assisted surgery. Operating time was shorter (207 ± 72 mins vs 306 ± 80 mins; P<0.001) and estimated blood loss was lower (205 ± 191 mL vs 331 ± 275 mL; P=0.045) with kidney clamp. No acute kidney injury occurred. Postoperative renal function was comparable between the two groups.

CONCLUSIONS

Partial nephrectomy using parenchymal clamping is safe and feasible in selected cases. The postoperative renal function and oncological control were satisfactory.

Whole-Organism Cellular Pathology: A Systems Approach to Phenomics

Phenotype is defined as the state of an organism resulting from interactions between genes, environment, disease, molecular mechanisms, and chance. The purpose of the emerging field of phenomics is to systematically determine and measure phenotypes across biology for the sake of understanding. Phenotypes can affect more than one cell type and life stage, so ideal phenotyping would include the state of every cell type within the context of both tissue architecture and the whole organism at each life stage. In medicine, high-resolution anatomic assessment of phenotype is obtained from histology. Histology's interpretative power, codified by Virchow as cellular pathology, is derived from its ability to discern diagnostic and characteristic cellular changes in diseased tissues. Cellular pathology is observed in every major human disease and relies on the ability of histology to detect cellular change in any cell type due to unbiased pan-cellular staining, even in optically opaque tissues. Our laboratory has shown that histology is far more sensitive than stereomicroscopy for detecting phenotypes in zebrafish mutants. Those studies have also shown that more complete sampling, greater consistency in sample orientation, and the inclusion of phenotypes extending over longer length scales would provide greater coverage of common phenotypes. We are developing technical approaches to achieve an ideal detection of cellular pathology using an improved form of X-ray microtomography that retains the strengths and addresses the weaknesses of histology as a screening tool. We are using zebrafish as a vertebrate model based on the overlaps between zebrafish and mammalian tissue architecture, and a body size small enough to allow whole-organism, volumetric imaging at cellular resolution. Automation of whole-organism phenotyping would greatly increase the value of phenomics. Potential societal benefits would include reduction in the cost of drug development, a reduction in the incidence of unexpected severe drug and environmental toxicity, and more rapid elucidation of the contributions of genes and the environment to phenotypes, including the validation of candidate disease alleles identified in population and personal genetics.

Effects of Laser Annealing Parameters on Optical and Electrical Properties of ITO/Metallic Glass Alloy Bi-layer Films

AgAlMg (AAM) films with three different atomic percentage compositions are prepared, namely, Ag12Al62Mg26 (denoted as A1AM), Ag22Al46Mg32 (denoted as A2AM), and Ag36Al25Mg39 (denoted as A3AM). In addition, the AAM films are deposited with four different thicknesses, i.e., 3, 6, 9, and 12 nm. The indium-tin oxide thickness is assigned a constant value of 30 nm in every case. The results show that the optical transmittance of the AAM/IAAM films improves (i.e., increases) with a reducing AAM film thickness, while the electrical resistivity improves (i.e., reduces) with an increasing film thickness. It is shown that the IA2AM film with an AMM thickness of 9 nm yields the optimal compromise between the optical transmittance and the electrical resistivity. The as-deposited IAAM films are found to have optical transmittance and electric resistivity values of 65 % and 90 Ω/□, respectively. The IA2AM films are annealed using a near-infrared laser at different pulse energies with a wavelength of 1064 nm and repetition rates ranging from 100 ~ 400 kHz. For both films, the optical and electrical properties are enhanced as the pulse energy increases to a certain critical value due to a transition from an amorphous microstructure to a crystalline structure. Given a repetition rate of 400 kHz and a pulse energy of 1.03 μJ, the optical transmittance and sheet resistance of the IAAM film are found to be 80 % and 15 Ω/□, respectively. The corresponding value of the Haacke figure of merit changed from 0.15 × 10(-3) to 7.16 × 10(-3) Ω(-1) due to the optimal laser annealing conditions.

Laparoscopic liver resection: lessons learnt after 100 cases

OBJECTIVE

To share our institutional experience in laparoscopic liver resection and our learning curve after the first 100 cases of laparoscopic liver resection.

DESIGN

Case series with internal comparison.

SETTING

A regional hospital in Hong Kong.

PATIENTS

Our institution started performing laparoscopic liver resection since 2006. All patients who underwent laparoscopic liver resections from March 2006 to October 2012 were identified in a prospectively collected database. The demographic data and operative outcomes of these patients were extracted, and results of the early (from March 2006 to May 2010) and late (from June 2010 to October 2012) study periods were compared.

RESULTS

Between March 2006 and October 2012, 100 laparoscopic liver resections were performed for 98 patients in the Department of Surgery, Kwong Wah Hospital, Hong Kong. They were 69 (70%) males and 29 (30%) females, and the median age was 65 years. The final histological diagnoses were as follows: hepatocellular carcinoma (n=72), colorectal liver metastases (n=14), intrahepatic cholangiocarcinoma (n=4), and benign disease (n=10). There were more anatomical resections, major hepatectomies as well as resections of more anatomically challenging right-sided and posterosuperior lesions in the late versus the early period; however, operative outcomes remained comparable in both periods.

CONCLUSION

Laparoscopic hepatectomies are feasible with growing experience. Bearing in mind the diversity in the level of operative techniques with various types of laparoscopic liver resections, more experience is needed to overcome the learning curve.

Multimedia manuscript: laparoscopic resection of hepatocellular carcinoma at segment 7: the posterior approach to anatomic resection

BACKGROUND

Open anatomical liver resections remain one of the most effective treatments of hepatocellular carcinoma (HCC) and results in better recurrence-free and overall survival compared to nonanatomical resections [1]. On the other hand, laparoscopic hepatectomies for HCC have recently emerged with the benefits of reduced blood loss, shorter hospital stay, and less severe wound pain [2, 3]. Classically, liver lesions considered suitable for laparoscopic resection were those small tumors (<4 cm) located over the anterior and left lateral segments [3]. However, we would like to expand the current indications and here we present our techniques of laparoscopic anatomical resection for a HCC that was located at right posteriosuperior segment 7.

METHODS

Our patient was a 60-year-old gentleman who had Child's A hepatitis B cirrhosis and was on entecavir. During a follow-up CT scan, a 2.6-cm segment 7 lesion with early arterial enhancement and contrast washout was noted and was subsequently confirmed with arteriogram. α-Fetoprotein was 3 ng/ml (normal < 20 ng/ml). The video demonstrates a posterior approach to laparoscopic resection of segment 7.

RESULTS

Operative time was 510 min. Blood loss was 800 ml and no perioperative transfusion was required. Postoperative recovery was uneventful and only simple oral analgesics were required for pain control. He was discharged on postoperative day 6. Histology showed a moderately differentiated hepatocellular carcinoma and all resection margins were clear. Subsequent follow-up CT scan 6 months after the operation showed no evidence of recurrence and α-fetoprotein level was normal.

CONCLUSIONS

Laparoscopic hepatectomy for HCC over the right posterior segment of the liver is feasible in selected patients with favorable results in terms of wound size, postoperative recovery, and hospital stay. Maximal liver conservation was achieved in performing oncologic anatomical resection of segment 7 instead of a posterior sectionectomy. On the other hand, a posterior approach was recommended because it allowed early intrahepatic control of pedicles and identification of the right hepatic vein to guide parenchymal transection along the intersegmental plane.

Methylprednisolone reduces the rates of postextubation stridor and reintubation associated with attenuated cytokine responses in critically ill patients

BACKGROUND

Treatment with corticosteroids can reduce the incidence of postextubation stridor (PES) and reintubation in critically ill adult patients, but the mechanisms remain unknown.

METHODS

A randomized, controlled clinical trial was conducted in an adult medical and surgical Intensive Care Unit (ICU) of a teaching hospital. Seventy-one patients who had a cuff leak percentage <24% of tidal volume received either a bolus injection of methylprednisolone at 40 mg (treated group, n=38) or normal saline (placebo group, n=33) 4 h prior to a planned extubation. The cuff leak percentage was re-assessed 1 h and 4 h post-injection. Eighty patients who had a cuff leak percentage ≥ 24% served as a control group. Plasma concentrations of multiple cytokines and C-reactive protein (CRP) were measured at baseline, 4 h and 24 h after the intervention.

RESULTS

The incidences of PES (15.8% vs. 39.4%, P<0.05) and reintubation rate (7.9% vs. 30.3%, P<0.05) were lower in the treated group compared to the placebo group. The plasma concentrations of IL-4 and IL-10 increased while the levels of IL-6 and IL-8 decreased at 24 h in the treated group compared to the placebo group. No difference in CRP levels was observed between the treated and placebo groups.

CONCLUSION

A single injection of methylprednisolone at the dose used 4 h prior to planned extubation effectively reduced the incidence of PES and the reintubation rate. These beneficial effects were associated with the up-regulation of IL-4 and IL-10 and the down-regulation of IL-6 and IL-8 in the critically ill adult patients.

Evolution of the haemagglutinin gene of the influenza A(H1N1)2009 virus isolated in Hong Kong, 2009–2011

Phylogenetic analysis of the haemagglutinin (HA) gene shows that the influenza A(H1N1)2009 viruses collected in Hong Kong clustered in two main branches characterised by the E391E and E391K amino acids. The main branch E391K evolved in two sub-branches with N142D and S202T mutations that first appeared in March and July 2010, respectively, with the latter becoming the predominant strain. These genetic variants that emerged display similar antigenic characteristics. Concurrent with genetic surveillance, laboratories should continue monitoring the circulating viruses antigenically.

Evolution of the haemagglutinin gene of the influenza A(H1N1)2009 virus isolated in Hong Kong, 2009-2011

Phylogenetic analysis of the haemagglutinin (HA) gene shows that the influenza A(H1N1)2009 viruses collected in Hong Kong clustered in two main branches characterised by the E391E and E391K amino acids. The main branch E391K evolved in two sub-branches with N142D and S202T mutations that first appeared in March and July 2010, respectively, with the latter becoming the predominant strain. These genetic variants that emerged display similar antigenic characteristics.Concurrent with genetic surveillance, laboratories should continue monitoring the circulating viruses antigenically.

Use of intrinsic clearance for prediction of human hepatic clearance

IMPORTANCE OF THE FIELD

The use of intrinsic metabolic stability/clearance and other in vitro pharmacokinetic data for the selection of drug candidates for clinical evaluation during discovery lead optimization has become one of the primary focuses of research organizations involved in new drug discovery. Using intrinsic clearance determined from human liver microsomal preparations and/or hepatocyte to predict human clearance has become more acceptable.

AREAS COVERED IN THIS REVIEW

This review focuses on the current methods for determining intrinsic clearance and scaling to predict human hepatic clearance, and novel physiologically-based models for improvement of human hepatic clearance prediction. Published microsomal metabolic stability data and in-house hepatocyte clearance data were compared with published in vivo human hepatic clearance data. Various scaling models and the effect of protein binding were examined.

WHAT THE READER WILL GAIN

Use of a novel microfluidic model and other physiologically-based models are presented. Microsomal metabolic clearance requires correction for protein binding and in vitro microsomal binding in order to better predict in vivo hepatic clearance of compounds that are mainly eliminated by hepatic metabolism.

TAKE HOME MESSAGE

Metabolic clearance obtained using hepatocytes may work well in combination with the well-stirred model. Novel models incorporating flow and protein binding in the system may be the most complete models for prediction of human in vivo metabolism.

Increase of plasma insulin by racecadotril, an inhibitor of enkephalinase, in Wistar rats

Racecadotril is known as an inhibitor of enkephalinase. Increase of plasma insulin by racecadotril has been observed in rats while the mechanism of the action remains obscure. In the present study, intravenous injection of male Wistar rats with racecadotril significantly decreased blood glucose levels. However, this effect of racecadotril was not modified by naloxone at the dose sufficient to block opioid receptors. Thus, the blood glucose-lowering action of racecadotril might be through an endogenous opioid independent mechanism. Otherwise, we found that C-peptide content was also raised by racecadotril in parallel with the increase of insulin in Wistar rats. Thus, the blood glucose-lowering action of racecadotril was related to insulin secretion, but not through the inhibition of plasma insulin degradation. In addition, racecadotril showed no direct effect on insulin secretion in isolated islets or cultured HIT-T15 beta cells. The increase of plasma insulin and blood glucose-lowering action induced by racecadotril were reduced by pretreatment with atropine and enhanced by physotigmine. Direct inhibition of cholinesterase was not observed in brain homogenates treated with racecadotril. Moreover, actions of racecadotril were significantly reduced in rats receiving hemicholinium-3 at a sufficient dose to decrease endogenous acetylcholine. Activation of cholinergic tone is possibly involved in the blood glucose-lowering effect of racecadotril. Our results suggested that racecadotril increased insulin secretion to lower blood glucose mainly via regulation of parasympathetic tone in Wistar rats.

A microfluidic hepatic coculture platform for cell-based drug metabolism studies

Within the global pharmaceutical and biotech industries, there is significant interest in identifying in vitro screening systems that are more human-relevant-i.e., that offer greater utility in predicting subcellular and cellular physiological responses in humans in vivo-and that thereby allow investigators to reduce the incidence of costly late-stage failures during pharmaceutical clinical trials, as well as to reduce the use of animals in drug testing. Currently incumbent in vitro screening methods, such as culturing human hepatocytes in suspension, while useful, are limited by a lack of long term cellular function. In order to address this limitation, we have established an integrated, microfluidic, in vitro platform that combines the patented HmuREL((R)) microdevice with a hepatic coculture system. In the present report, we use this platform to study clearance and metabolite generation of a battery of molecular entities. The results show that the flow-based coculture system is capable of clearing, with improved resolution and predictive value, compounds with high, medium, and low clearance values. In addition, when coculture is coupled with flow, higher metabolite production rates are obtained than in static systems.

Surveillance and outcome of liver metastasis in patients with colorectal cancer who had undergone curative-intent operation

OBJECTIVE

To assess the outcome of patients diagnosed to have liver metastasis by ultrasonography, following curative-intent resection of colorectal adenocarcinoma.

DESIGN

Prospective study.

SETTING

Regional hospital, Hong Kong.

PATIENTS

A total of 650 patients who underwent curative-intent resection of colorectal adenocarcinoma between January 2000 and December 2006.

MAIN OUTCOME MEASURES

Pattern of liver recurrence, treatment and outcome after recurrence, and overall patient survival.

RESULTS

Of the 650 patients, 553 (85%) were followed up per protocol. Of 104 patients who developed systemic recurrence, 45 (43%) had liver-only metastases. The resection rate for liver metastases was 38% (17/45). The median survival of such patients was significantly longer than those who did not undergo liver metastasectomy (50 vs 26 months, P=0.017).

CONCLUSION

Our ultrasonography-based surveillance protocol was low-cost, simple, and effective in detecting asymptomatic liver metastases, so that curative-intent metastasectomy could be performed. Further prospective studies are required to determine the optimal frequency and imaging mode for surveillance, so as to improve the resectability of liver-only colorectal metastases as well as overall patient survival.

Effect of transgenes on global gene expression in soybean is within the natural range of variation of conventional cultivars

Current safety assessment for novel crops, including transgenic crops, uses a targeted approach, which relies on compositional analysis. The possibility that transgene expression could lead to unintended effects remains a debated issue. This study used transcriptome profiling as a nontargeted approach to evaluate overall molecular changes in transgenic soybean cultivars. Global gene expression was measured in the first trifoliate leaves of two transgenic and three conventional soybean cultivars using the soybean Affymetrix GeneChip. It was found that gene expression differs more between the two conventional cultivars than between the transgenics and their closest conventional cultivar investigated and that the magnitudes of differences measured in gene expression and genotype (determined by SSR analysis) do not necessarily correlate. A MySQL database coupled with a CGI Web interface was developed to store and present the results ( http://soyxpress.agrenv.mcgill.ca/). By integrating the microarray data with gene annotations and other soybean data, a comprehensive view of differences in gene expression is explored between cultivars.

Inhibition of N-acetyltransferase activity and gene expression in human colon cancer cell lines by diallyl sulfide

Diallyl sulfide (DAS) is one of the major components of garlic (Allium sativum) and is widely used in the world for food. In this study, DAS was selected for testing the inhibition of arylamine N-acetyltransferase (NAT) activity (N-acetylation of 2-aminofluorene) and gene expression (mRNA NAT) in human colon cancer cell lines (colo 205, colo 320 DM and colo 320 HSR). The NAT activity was examined by high performance liquid chromatography and indicated that a 24 h DAS treatment decreases N-acetylation of 2-aminofluorene in three colon (colo 205, 320 DM and colo 320 HSR) cancer cell lines. The NAT enzymes (protein) were analyzed by western blotting and flow cytometry and it indicated that DAS decreased the levels of NAT in three colon (colo 205, 320 DM and colo 320 HSR) cancer cell lines. The gene expression of NAT (mRNAT NAT) was determined by polymerase chain reaction (PCR), it was shown that DAS affect mRNA NAT expression in examined human colon cancer cell lines. This report is the first to demonstrate that DAS does inhibit human colon cancer cell NAT activity and gene expression.

Patient effective dose from sentinel lymph node lymphoscintigraphy in breast cancer: a study using a female humanoid phantom and thermoluminescent dosemeters

The aim of this study was to measure the dose delivered to patients undergoing sentinel lymph node lymphoscintigraphy by taking into account both the transmission scan dose using a (57)Co flood source and the (99)Tc(m) internal emission dose. An adult female humanoid phantom and a set of thermoluminescent dosimeters were used in the measurements. The choice of measurement organs in the humanoid was guided by the recommendations described in the International Commission on Radiological Protection report number 60. A (57)Co flood source was used in external transmission to irradiate the humanoid at posterior, left lateral, left posterior oblique, right lateral and right posterior oblique positions. Four (99)Tc(m) deposits as internal emission sources were used to simulate patient peritumoural injection. The individual effective doses for external transmission and internal emission, normalized to the cumulated activity and expressed in micro Sv(MBq x h)(-1) were then calculated. The effective dose for a transmission scan was on average 0.061 micro Sv(MBq x h)(-1) for each (57)Co flood source position and for internal emission 0.312 micro Sv(MBq x h)(-1) and 0.291 micro Sv(MBq x h)(-1) for left and right breast injection, respectively. Using these results, the effective dose from both transmission and emission sources can be calculated according to the nuclear medicine scanning protocol and surgical procedure of the individual institution. For our protocols, the patient receives a maximum effective dose of 52 micro Sv for the 1 day protocol (18 MBq injection) and 204 micro Sv for the 2 day protocol (74 MBq injection) if only the sentinel lymph node is excised. If other tissues containing radioactivity are removed, the patient effective dose will be reduced by about 50% and 6%, respectively, for the 1 day protocol and 2 day protocol. Although the doses are low compared with other radiological examinations, the results are informative for patients concerned about radiation exposure for this new imaging technique.

Curcumin inhibited the arylamines N-acetyltransferase activity, gene expression and DNA adduct formation in human lung cancer cells (A549)

It is well known that N-acetyltransferase (NAT) plays an important role in the arylamine metabolism. We analysed the response of A549 human lung cancer cells for N-acetylation of 2-aminofluorene (AF) to curcumin. After curcumin treatment, the NAT activity was examined by HPLC, AF-DNA adduct formation was examined by HPLC, and NAT gene expression by polymerase chain reaction were detected. The NAT activity in the human A549 cells and cytosols was suppressed by curcumin in a dose-dependent manner. The results also demonstrated that gene expression (NAT1 mRNA) in human lung A549 tumor cells was inhibited and decreased by curcumin. After the incubation of human lung A549 tumor cells with AF with or without curcumin co-treatment, the cells were recovered and DNA was prepared and hydrolyzed to nucleotides. The adducted nucleotides were extracted into butanol and analyzation of AF-DNA adducts was done by HPLC. The results also demonstrated that curcumin decreases AF-DNA adduct formation in the human lung A549 tumor cells.

The repertoire of Na,K-ATPase alpha and beta subunit genes expressed in the zebrafish, Danio rerio

We have identified a cohort of zebrafish expressed sequence tags encoding eight Na,K-ATPase alpha subunits and five beta subunits. Sequence comparisons and phylogenetic analysis indicate that five of the zebrafish alpha subunit genes comprise an alpha1-like gene subfamily and two are orthologs of the mammalian alpha3 subunit gene. The remaining alpha subunit clone is most similar to the mammalian alpha2 subunit. Among the five beta subunit genes, two are orthologs of the mammalian beta1 isoform, one represents a beta2 ortholog, and two are orthologous to the mammalian beta3 subunit. Using zebrafish radiation hybrid and meiotic mapping panels, we determined linkage assignments for each alpha and beta subunit gene. Na,K-ATPase genes are dispersed in the zebrafish genome with the exception of four of the alpha1-like genes, which are tightly clustered on linkage group 1. Comparative mapping studies indicate that most of the zebrafish Na,K-ATPase genes localize to regions of conserved synteny between zebrafish and humans. The expression patterns of Na,K-ATPase alpha and beta subunit genes in zebrafish are quite distinctive. No two alpha or beta subunit genes exhibit the same expression profile. Together, our data imply a very high degree of Na,K-ATPase isoenzyme heterogeneity in zebrafish, with the potential for 40 structurally distinct alpha/beta subunit combinations. Differences in expression patterns of alpha and beta subunits suggest that many of the isoenzymes are also likely to exhibit differences in functional properties within specific cell and tissue types. Our studies form a framework for analyzing structure function relationships for sodium pump isoforms using reverse genetic approaches.

Oral administration of collagen conjugated with cholera toxin induces tolerance to type II collagen and suppresses chondritis in an animal model of autoimmune ear disease

B10.RIII (H-2r) mice were orally administered cyanogen bromide peptide 11 (CB11) or cholera toxin B (CTB)-conjugated CB11 to induce tolerance in collagen-induced autoimmune ear disease. Oral administration of a high dosage of CB11 provided partial protection from chondritis. However, administration of a tiny amount of CTB-CB11 conjugate effectively suppressed chondritis. Oral administration of CTB-CB11 conjugate did not alter the stimulation of T cells in vitro or the fine specificities of B cells. The oral administration of CTB-CB11 caused a higher level of type II collagen-specific IgG and its subclass. Interestingly, increases of TH1 cytokine (interferon-gamma) in Peyer's patches and of TH1/TH2 cytokines (interleukin-2 and interleukin-4) in lymph nodes were detected in mice that had been fed CTB-CB11. An increase of CD8+ T cells in the Peyer's patches with a decrease of CD8+ T cells in lymph nodes was seen in mice that had been fed CTB-CB11. These results suggest that protection from chondritis by oral administration of minute amounts of CTB-CB11 conjugate can be achieved by a mechanism distinct from that of conventional oral tolerance induction.

Proto-oncogene Raf-1 as an autoantigen in Meniere's disease

The 28 kd protein extracted from the guinea pig inner ear membranous fraction, which reacted with sera from patients with Meniere's disease, has been subjected to microsequencing. Nineteen amino acids were obtained (IVQQFGFQRRASDDGKLTQ). A protein data bank search showed that this sequence corresponded to residues 41 to 60 of human Raf-1 protein. Sera from 16 of 27 patients with Meniere's disease showed reactivity to the recombinant purified glutathione-S-transferase-Raf-1 protein. These results support the hypothesis that a subgroup of patients who suffer from Meniere's disease, as well as some other kinds of autoimmune inner ear diseases, have an autoantibody against Raf-1 protein.

Centromere-linked microsatellite markers for linkage groups 3, 4, 6, 7, 13, and 20 of zebrafish (Danio rerio)

A large number of interesting mutations affecting development and organogenesis have been identified through genetic screens in zebrafish. Mapping of these mutations to a chromosomal region can be rapidly accomplished using half-tetrad analysis. However, knowledge of centromere-linked markers on every chromosome is essential to this mapping method. Centromeres on all 25 linkage groups have been mapped on the RAPD zebrafish genetic map. However, species specificity and the lack of codominance make RAPD markers less practical for mapping than microsatellite-based markers. On the microsatellite-based genetic map, centromere-linked markers have been identified for 19 linkage groups. No direct evidence has been published linking microsatellite markers to the centromeres of linkage groups 3, 4, 6, 7, 13, and 20. Therefore, we compared the microsatellite-based genetic map with the RAPD map to identify markers most likely linked to the centromeres of these 6 linkage groups. These candidate markers were tested for potential centromere linkage using four panels of half-tetrad embryos derived by early-pressure treatment of eggs from four different female zebrafish. We have identified microsatellite markers for linkage groups 3, 4, 6, 7, 13, and 20 to within 1.7 cM of their centromeres. These markers will greatly facilitate the rapid mapping of mutations in zebrafish by half-tetrad analysis.

Ethylnitrosourea induces neoplasia in zebrafish (Danio rerio)

The zebrafish (Danio rerio) has been successfully used to discover hundreds of genes involved in development and organogenesis. To address the potential of zebrafish as a cancer model, it is important to determine the susceptibility of zebrafish to tumors. Germ line mutations are most commonly induced for zebrafish mutant screens by exposing adult male zebrafish to the alkylating agent, ethylnitrosourea (ENU). To determine whether ENU induces tumors, we compared the incidence of tumors in ENU-treated fish with untreated controls. Interestingly, 18 of 18 (100%) fish mutagenized with either 2.5 or 3.0 mM ENU developed epidermal papillomas, which numbered 1 to 22 per fish, within 1 year of treatment. The induced epidermal lesions included epidermal hyperplasia, flat papillomas (0.2 to 1.2 mm), and pedunculated papillomas (1.2 to 8 mm in greatest dimension), but no skin cancers. Angiogenesis was evident in papillomas larger than approximately 1 mm. All but two papillomas contained the three cell types (keratinocytes, club, and mucous cells) of normal zebrafish epidermis; histologic variants lacked either club cells or mucous cells. Two cavernous hemangiomas and a single malignant peripheral nerve sheath tumor were also found in the treated fish. None of five untreated controls developed tumors. These studies establish the feasibility of the zebrafish as an experimental model for the study of skin tumors.

Murine model of autoimmune hearing loss induced by myelin protein P0

Myelin protein P0 has been identified as an autoantigen in inner ear diseases. In order to study autoimmune hearing loss, we performed brain stem auditory-evoked potential (BAEP) studies on P0-sensitized mice. Two P0-sensitized mice showed hunched posture, poor coat, loss of body weight, and abnormal walking with a waddling gait. About 25% of the P0-sensitized mice developed hearing loss. In the BAEP study, peak latencies of waves I, III, and V and the interpeak latency I-III were prolonged in the P0-sensitized hearing loss group of mice. Hearing thresholds were elevated in this group of mice in comparison with the control mice. Inflammatory cell infiltration was observed in the cochlear nerve region, and a reduced number of spiral ganglion cells was also detected. These results suggest that P0-sensitized mice are a useful model for studying autoimmune inflammation of the peripheral portion of the auditory system.

Alternation of one-lung and two-lung ventilations with the same single-lumen endobronchial tube during thoracoscopic surgery--a case report

One-lung ventilation is sometimes necessary for procedures performed through thoracotomy. Single lumen endobronchial tube has been used purposefully for one lung ventilation since 1931. However, there are no reports on intra-operative alternation of one-lung and two-lung ventilations through the same single lumen endobronchial tube as it can only provide unilateral lung ventilation. We present a case in whom a tube exchanger was used to readjust tube position so as to provide alternation of one-lung and two-lung ventilations in a thoracoscopic procedure.

Successful prevention of retrocochlear hearing loss in murine experimental allergic encephalomyelitis with T cell receptor Vbeta8-specific antibody

Experimental allergic encephalomyelitis is an animal model of a T cell-mediated autoimmune disease -- for example, multiple sclerosis. We demonstrated that mice with experimental allergic encephalomyelitis developed retrocochlear hearing loss, and that the lesion of the auditory pathway might be related to T cell receptor Vbeta8-expressing T cells. To investigate whether anti-Vbeta8 antibody could prevent hearing loss, we carried out brain stem auditory evoked potential testing, histologic examinations, and flow cytometry in antibody-treated and control myelin basic protein-immunized B10.PL mice. The antibody was administered just before immunization of myelin basic protein. The disease incidence and severity were significantly reduced in the mice injected with the antibody. The results of brain stem auditory evoked potential testing, histologic examinations, and flow cytometry indicated that the depletion of Vbeta8-expressing T cells brings the prevention of hearing loss, as well as prevention of other neurologic deficits. The development of T cell receptor-specific antibody therapy might help treat retrocochlear hearing loss in multiple sclerosis.

Agarose-embedded tissue arrays for histologic and genetic analysis

To facilitate the histologic analysis of large numbers of 7-day-old zebrafish (Danio rerio), a method has been developed to process them in agarose-embedded arrays. Using thin tissue sections, the morphology of cells and tissues can be examined microscopically to investigate a variety of biologic processes. Because of their small size, precise arrangement of the larvae is necessary to section them simultaneously. A technique was designed to embed groups of zebrafish larvae in a single plane in agarose before sectioning. Stained tissue sections of thousands of larvae can be examined efficiently using this embedding method. In addition to histologic analysis, PCR-based genotypic analysis of DNA from individual larval sections is also possible. This technique can be modified to accommodate any study that requires the histologic examination of many pieces of tissue.

Clonal expansion of T-cell receptor beta gene segment in the retrocochlear lesions of EAE mice

It has been reported that the T cell receptor V beta 8.2 (TcrbV8.2) gene segment is predominantly expressed in encephalomyelitic T cells responding to myelin basic protein (MBP) in experimental allergic encephalomyelitis (EAE) mice. We have demonstrated retrocochlear hearing loss in EAE mice in previous studies. Administration of a monoclonal antibody specific to the T cell receptor V beta 8 (TcrbV8) subfamily prevented both this type of hearing loss and the central nerve disease. In this study, we examined the role of the TcrbV8.2 gene segment in the retrocochlear lesions of EAE mice. A clonal expression of T cell receptor beta chain gene segment (TcrbV8.2-TcrbD2-TcrbJ2.7) was identified in the retrocochlear lesions. The TcrbV8.2 gene segment appears to recombine only with TcrbJ2.1 (32.1%) and TcrbJ2.7 (67.9%) gene segments. The TcrbJ2.7 gene segment has also been previously identified as the dominant TcrbJ gene in the lymph nodes of EAE mice. Only TcrbD2, with a length of 4 amino acids, was observed recombining with these TcrbV8.2 sequences. G and C nucleotides are predominantly expressed at the N regions between the V-D and D-J junctions. This dominant TcrbV gene segment (TcrbV8.2-TcrbD2-TcrbJ2.7) observed in the retrocochlear lesions has been identified in the MBP-specific T cells from the lymph nodes of EAE mice. These results suggest that a small subset of antigen-specific T cells migrate to, and expand at, the retrocochlear lesions, which leads to hearing loss.

Transient bone marrow oedema: a variant pattern of sacral insufficiency fractures

A 71-year-old woman presenting with severe low back pain was found to have a large oval area of increased sacral uptake on Tc-99m MDP scan, with corresponding T1-hypointense and T2-hyperintense areas on magnetic resonance (MR) images, highly suggestive of malignancy. Open biopsies showed only callus formation. The patient responded clinically to conservative measures, with twice-repeated follow-up Tc-99m MDP and MR scans documenting resolution of transient bone marrow oedema. We suggest that this form of marrow oedema represents a variant pattern of sacral insufficiency fractures.

Genetic dissection of vertebrate processes in the zebrafish: a comparison of uniparental and two-generation screens

Genetic dissection is used to identify important genes in biological processes and is accomplished through the generation and study of mutations in model organisms. In diploid organisms, recessive mutations must be rendered hemizygous or homozygous for the mutant phenotype to be detected. In zebrafish (Danio rerio), this can be accomplished in two ways: (i) crosses between siblings who are potential carriers (in two-generation screens) and (ii) the generation of uniparental progeny. Two-generation screens have been the most productive to date but require substantial resources. However, uniparental screens involving haploids and half-tetrads (products of meiosis I) have also been productive, and require more modest resources. In genetic screens, the fraction of an average genome that is heterozygous (heterozygosity index) is inversely proportional to the likelihood that separate recessive mutations will be homozygous at the same time. Heterozygosity indices for haploid, half-tetrad, and two-generation screens are 0, 66, and 87.5%, respectively. Family sizes required to minimize bias in half-tetrad screens are also calculated. We conclude that gynogenetic half-tetrad screens are genetically robust and technically accessible to the independent researcher. The increasingly powerful genetic and experimental tools available for work with zebrafish can be used to address a broad range of questions in vertebrate biology.

House dust mite-induced sensitivity in mice

Sensitivity induced by house dust mite (HDM) extract in mice was investigated in this study. Sensitized B10.RIII mice (H-2r background) had T-cell proliferative responses to HDM extract in vitro and an HDM-specific IgE response. When mice were immunized by injection and intranasal inhalation with HDM extract, a histologic study showed eosinophils and mononuclear cell infiltration in the lung tissue and bronchial wall. Tcr alphabeta-positive cells were also found in the cell infiltration area of the lung lesions. In the control mice that were immunized by injection or intranasal inhalation (but not both), we did not observe cell accumulation in the lung tissue or in the bronchial wall. Epitope studies suggest that T cells recognize multiple epitopes. Molecular analysis of these HDM-specific T-cell hybridoma clones suggest that T-cell receptor use is restricted to members of the V alpha 8 and Vbeta 6 subfamilies.

TCRV and TCRJ gene usage in MBP responding T cells from (B10.PL x PL/J)F1 mice is biased towards that of B10.PL mice

We analyzed myelin basic protein (MBP) specific T cell hybridoma clones from (B10.PL x PL/J)F1 mice. MBP-reacting T cell hybridomas from F1 mice preferentially expressed B10.PL TcraV2.3 (53%) and B10.PL TcraV4.2 (13%) with minor expression of TcraV4.4 (13%) gene segments. A dominant expression of TcrbV8.2 (73%) accompanying with TcrbV8.1 (20%) and TcrbV13 (7%) gene segments have been identified in these MBP-reacting T cell hybridomas from F1 mice. There was less restrictive but non-random usage of the TcraJ and TcrbJ gene segments. Overall, the MBP-reacting T cell hybridomas from (B10.PL x PL/J)F1 mice were dominated by the MBP-reacting T cell pattern seen in B10.PL mice.

Patient-ventilator flow dyssynchrony: flow-limited versus pressure-limited breaths

OBJECTIVES

Patient-ventilator flow dyssynchrony occurs when ventilator flow delivery is insufficient to meet patient demands. If sufficiently severe, flow dyssynchrony can produce significant imposed loads on ventilatory muscles. Flow dyssynchrony can be improved by increasing ventilator flow delivery. We hypothesized that the variable flow pressure-limited breath would be a better approach for matching patient flow demands than adjusting a set flow on a conventional volume-cycled breath.

DESIGN

Clinical interventional study.

SETTING

Medical intensive care unit.

PATIENTS

Sixteen stable, mechanically ventilated patients receiving volume-cycled assist-control ventilation.

INTERVENTIONS

Flow dyssynchrony was produced by reducing the set flow by 50%. Dyssynchrony was quantified by measuring the esophageal pressure time product during the assisted breath. Two strategies were then employed in an attempt to reduce the dyssynchrony. One strategy was to increase flow back to the initial set flow and then further increase flow by an additional 25% (VI strategy). The other strategy was to use a pressure-limited breath feature coupled to a volume assist breath (the P strategy). With the P strategy, the pressure limit was set at 75% and 100% of the static elastic recoil pressure at end-inspiration.

MEASUREMENTS AND MAIN RESULTS

Pressure time product, intrinsic positive end-expiratory pressure, and the ventilatory pattern were measured with each strategy and were analyzed by analysis of variance. Induced baseline flow dyssynchrony, as measured by the pressure time product, was > 5 cm H2O/sec in ten of 16 patients. This dyssynchrony was significantly reduced by both the VI strategy and the P strategy, although the P strategy appeared to be more effective in those patients with the greatest baseline dyssynchrony. Baseline inspiratory time was also shortened by both the VI strategy and the P strategy; the VI strategy shortened baseline inspiratory time more than the P strategy. Baseline tidal volume, frequency, and intrinsic positive end-expiratory pressure were only minimally affected by either strategy.

CONCLUSION

The pressure-limited, variable-flow approach to ventilator gas delivery appears to be more responsive to a vigorous patient effort than a fixed-flow approach.