Abstract 106: Transintestinal Cholesterol Excretion and Macrophage Reverse Cholesterol Transport are not Stimulated in Hepatic ABCG8 Knockdown Mice Treated with an LXR Agonist

Transintestinal cholesterol excretion (TICE) is a recently discovered pathway by which cholesterol travels from plasma to the small intestine for direct excretion into the feces. Hallmarks of animal models with TICE include severely diminished biliary cholesterol secretion but near normal levels of hepatic cholesterol and fecal neutral sterol excretion. Using an ATP binding cassette transporter G8 (ABCG8) antisense oligonucleotide (ASO) to knock down ABCG8 specifically in liver (G8 HKD ), we created a novel mouse model with significantly decreased biliary cholesterol excretion but a 658% increase in hepatic cholesterol accumulation and a 78% reduction in fecal neutral sterol excretion, indicating a dysfunction in the TICE pathway. LXR agonists have previously been shown to stimulate the TICE pathway. In order to more definitively prove the TICE pathway was disfunctional in G8 HKD mice, we treated wild type (WT) and G8 HKD mice with the LXR agonist T0901317 and measured markers of TICE stimulation. As expected, in WT mice, T0901317 doubled biliary cholesterol concentrations. A similar effect was seen in G8 HKD mice treated with T0901317, but biliary cholesterol concentrations remained significantly less than their WT counterparts. These levels of biliary cholesterol closely mirrored hepatic ABCG8 mRNA expression. T0901317 stimulated fecal neutral sterol excretion by >1000% in wild type mice but only by 190% in G8 HKD mice. These data indicate that TICE is disfunctional in G8 HDK mice since the pathway was not stimulated to the same extent in WT and G8 HKD mice by an LXR agonist. Some controversy remains over whether the TICE pathway transports macrophage derived cholesterol. In order to address this issue, we performed a macrophage RCT assay on WT and TICE disfunctional G8 HKD mice. T0901317 stimulated macrophage RCT (fecal neutral sterol 3H dpm) by >2300% in wild type mice but only by 370% in G8 HKD mice. T0901317 increased fecal acidic sterol 3H count by 65-75% in both wild type and G8 HKD mice. These results indicate that macrophage RCT is impaired when the TICE pathway is decreased. In sum, our data shows that hepatic ABCG8 plays a key role in the TICE pathway and that impairing the TICE pathway through hepatic ABCG8 knockdown causes decreased macrophage RCT.

Abstract 396: Acute Hepatic ACAT2 Knockdown Transiently Increases Plasma and Hepatic Free Cholesterol and Fecal Neutral Sterol Excretion

In spite of the advent of statins, atherosclerotic coronary vascular disease (ASCVD) remains the number one killer of Americans. A way to reduce LDL cholesterol, the primary risk factor of ASCVD, is to increase cholesterol excretion from the body. Our group and others have recently found that cholesterol excretion can be facilitated by both biliary and non-biliary pathways. The lipoprotein that delivers cholesterol from the liver through the plasma to the small intestine for transintestinal cholesterol excretion (TICE) is not yet known. We have previously shown that chronic knockdown in mice of hepatic acyl-CoA cholesterol acyltransferase 2 (ACAT2), a cellular enzyme that converts free cholesterol (FC) into cholesteryl ester (CE), appeared to cause the formation of hepatic apoB-containing lipoproteins that preferentially trafficked cholesterol to the small intestine for TICE. We tested the hypothesis that the plasma concentration of TICE-competent, apoB-containing lipoproteins, could be increased by preloading the liver with cholesterol and then acutely depleting the cholesterol by knocking down hepatic ACAT2 with antisense oligonucleotides (ASO). After feeding a high cholesterol (0.2% wt/wt) diet for six weeks, C57BL/6 mice were treated with control non-targeting ASO or ACAT2 ASO for one or two weeks. After only one week of ACAT2 knockdown (ACAT2KD) hepatic ACAT2 protein expression was decreased nearly 80%. This translated into a 50% decrease in hepatic CE concentration in conjunction with a rarely seen 2-fold increase in hepatic FC concentration. Acute hepatic ACAT2KD increased plasma FC levels by 25%, which subsided after two weeks of treatment. The increased plasma FC was primarily associated with large and small LDL. After one week of hepatic ACAT2KD mice had a minor, non-significant increase in biliary cholesterol levels but had a 2-fold increase in fecal neutral sterol (FNS) excretion. In summary our data show that when CE is rapidly cleared from the liver, FNS levels dramatically increase with a transient increase in hepatic and plasma FC levels. We believe that in the ACAT2KD mice the increased plasma FC associated with LDL is feeding into TICE thus resulting in increased FNS.

Effects of surface functional groups on the formation of nanoparticle-protein corona

Herein, we examined the dependence of protein adsorption on the nanoparticle surface in the presence of functional groups. Our UV-visible spectrophotometry, transmission electron microscopy, infrared spectroscopy, and dynamic light scattering measurements evidently suggested that the functional groups play an important role in the formation of nanoparticle-protein corona. We found that uncoated and surfactant-free silver nanoparticles derived from a laser ablation process promoted a maximum protein (bovine serum albumin) coating due to increased changes in entropy. On the other hand, bovine serum albumin displayed a relatively lower affinity for electrostatically stabilized nanoparticles due to the constrained entropy changes.

Development of a method for analyzing three-dimensional scapula kinematics

BACKGROUND

Scapula mobility complicates upper extremity kinematics assessment. Existing methods are diverse, providing inconsistent results. The current gold standard (bone pins) is prohibitively invasive. The purposes of the current study are to describe a virtual projection alternative to surface markers for video motion capture (VMC) of the scapula and to compare the results of the projection and surface marker methods to the results of similar existing methods.

METHODS

Ten participants were evaluated using VMC. Surface markers were applied to the trunk and arm in accordance with existing guidelines. Three markers were affixed to plastic base on the skin over the acromion process. Other scapular landmarks were digitized in a neutral position. These landmarks' locations were defined in reference to the acromion cluster and used to generate the projection. Humerothoracic, glenohumeral, and scapulothoracic kinematics were evaluated during shoulder abduction, flexion, and scaption. Joint angles produced by the surface markers and the projection were compared by Bonferroni-adjusted t tests. The results were compared to prior findings in the literature.

RESULTS

The projection resulted in greater scapulothoracic upward rotation, internal rotation, and anterior-posterior tilt and less glenohumeral elevation (p < .0055) than did surface markers. The virtual scapula produced greater estimates of scapular mobility than did surface markers, corresponding to pre-existing results from similar methodologies.

CONCLUSIONS

The result is a noninvasive measurement tool that produces different and superior results than do scapula surface markers. Measuring scapula kinematics via VMC without bone pins will facilitate future investigations into interactions between upper extremity injury, kinematics, and activity performance.

Long-term follow-up of the Medical Research Council CLASICC trial of conventional versus laparoscopically assisted resection in colorectal cancer

BACKGROUND

Laparoscopic resection is used widely in the management of colorectal cancer; however, the data on long-term outcomes, particularly those related to rectal cancer, are limited. The results of long-term follow-up of the UK Medical Research Council trial of laparoscopically assisted versus open surgery for colorectal cancer are presented.

METHODS

A total of 794 patients from 27 UK centres were randomized to laparoscopic or open surgery in a 2:1 ratio between 1996 and 2002. Long-term follow-up data were analysed to determine differences in survival outcomes and recurrences for intention-to-treat and actual treatment groups.

RESULTS

Median follow-up of all patients was 62·9 (interquartile range 22·9 - 92·8) months. There were no statistically significant differences between open and laparoscopic groups in overall survival (78·3 (95 per cent confidence interval (c.i.) 65·8 to 106·6) versus 82·7 (69·1 to 94·8) months respectively; P = 0·780) and disease-free survival (DFS) (89·5 (67·1 to 121·7) versus 77·0 (63·3 to 94·0) months; P = 0·589). In colonic cancer intraoperative conversions to open surgery were associated with worse overall survival (hazard ratio (HR) 2·28, 95 per cent c.i. 1·47 to 3·53; P < 0·001) and DFS (HR 2·20, 1·31 to 3·67; P = 0·007). In terms of recurrence, no significant differences were observed by randomized procedure. However, at 10 years, right colonic cancers showed an increased propensity for local recurrence compared with left colonic cancers: 14·7 versus 5·2 per cent (difference 9·5 (95 per cent c.i. 2·3 to 16·6) per cent; P = 0·019).

CONCLUSION

Long-term results continue to support the use of laparoscopic surgery for both colonic and rectal cancer.

Evidences For Charge Transfer-Induced Conformational Changes In Carbon Nanostructure-Protein Corona

The binding of proteins to a nanostructure often alters protein secondary and tertiary structures. However, the main physical mechanisms that elicit protein conformational changes in the presence of the nanostructure have not yet been fully established. Here we performed a comprehensive spectroscopic study to probe the interactions between bovine serum albumin (BSA) and carbon-based nanostructures of graphene and single-walled carbon nanotubes (SWNTs). Our results showed that the BSA "corona" acted as a weak acceptor to facilitate charge transfer from the carbon nanostructures. Notably, we observed that charge transfer occurred only in the case of SWNTs but not in graphene, resulting from the sharp and discrete electronic density of states of the former. Furthermore, the relaxation of external α-helices in BSA secondary structure increased concomitantly with the charge transfer. These results may help guide controlled nanostructure-biomolecular interactions and prove beneficial for developing novel drug delivery systems, biomedical devices and engineering of safe nanomaterials.

Space-time resolved simulation of femtosecond nonlinear light-matter interactions using a holistic quantum atomic model: application to near-threshold harmonics

We introduce a new computational approach for femtosecond pulse propagation in the transparency region of gases that permits full resolution in three space dimensions plus time while fully incorporating quantum coherent effects such as high-harmonic generation and strong-field ionization in a holistic fashion. This is achieved by utilizing a one-dimensional model atom with a delta-function potential which allows for a closed-form solution for the nonlinear optical response due to ground-state to continuum transitions. It side-steps evaluation of the wave function, and offers more than one hundred-fold reduction in computation time in comparison to direct solution of the atomic Schrödinger equation. To illustrate the capability of our new computational approach, we apply it to the example of near-threshold harmonic generation in Xenon, and we also present a qualitative comparison between our model and results from an in-house experiment on extreme ultraviolet generation in a femtosecond enhancement cavity.

On the relative roles of higher-order nonlinearity and ionization in ultrafast light-matter interactions

Far off-resonant ultrafast and nonlinear light-matter interactions are studied using a one-dimensional atomic model. Results from a pump-probe diagnostic reveal that any higher-order nonlinear refraction is masked by ionization-induced defocusing before it becomes significant. On the other hand, we show that signatures of a higher-order nonlinearity may still be manifest via low-order harmonics of the pump center frequency. Implications for filamentation of femtosecond pulses are pointed out.

Description of viral assemblages associated with the Gorgonia ventalina holobiont

The diversity and function of viruses in coral holobionts has only recently received attention. The non-reef building gorgonian octocoral, Gorgonia ventalina, is a major constituent of Caribbean reefs. We investigated viral communities associated with G. ventalina tissues to understand their role in gorgonian ecology. Pyrosequencing was used to prepare a total of 514,632 sequence reads of DNA- and RNA-based mixed-community viral genomes (metaviromes). RNA viral assemblages were comprised of primarily unidentifiable reads, with most matching host transcripts and other RNA metaviromes. DNA metaviromes were similar between healthy and diseased tissues and comprised of contiguous sequences (contigs) that matched primarily metazoan and bacterial proteins. Only ~5% of contigs matched viral proteins that were primarily cyanophage and viruses of Chlorella and Ostreococcus. Our results confirm that DNA and RNA viruses comprise a component of the gorgonian holobiont, suggesting that they may play a role in the ecology of G. ventalina.

New test of local Lorentz invariance using a 21Ne-Rb-K comagnetometer

We develop a new comagnetometer using (21)Ne atoms with nuclear spin I=3/2 and Rb atoms polarized by spin exchange with K atoms to search for tensor interactions that violate local Lorentz invariance. We frequently reverse the orientation of the experiment and search for signals at the first and second harmonics of the sidereal frequency. We constrain 4 of the 5 spatial Lorentz-violating coefficients c(jk)(n) that parametrize anisotropy of the maximum attainable velocity of a neutron at a level of 10(-29), improving previous limits by 2 to 4 orders of magnitude and placing the most stringent constraint on deviations from local Lorentz invariance.

Targeting SDF-1/CXCR4 to inhibit tumour vasculature for treatment of glioblastomas

Local recurrence of glioblastomas is a major cause of patient mortality after definitive treatment. This review discusses the roles of the chemokine stromal cell-derived factor-1 and its receptor CXC chemokine receptor 4 (CXCR4) in affecting the sensitivity of glioblastomas to irradiation. Blocking these molecules prevents or delays tumour recurrence after irradiation by inhibiting the recruitment of CD11b+ monocytes/macrophages that participate in revascularising the tumour. We review the literature pertaining to the mechanism by which revascularisation occurs following tumour irradiation using experimental models. Areas of interest and debate in the literature include the process by which endothelial cells die after irradiation and the identity/origin of the cells that reconstitute the tumour blood vessels after injury. Understanding the processes that mediate tumour revascularisation will guide the improvement of clinical strategies for preventing recurrence of glioblastoma after irradiation.

Association between bovine digital dermatitis treponemes and a range of 'non-healing' bovine hoof disorders

This study describes the association between bovine digital dermatitis (BDD) treponemes and three 'non-healing' bovine hoof horn lesions, namely, 'toe necrosis' (TN), 'non-healing white line disease' (nhWLD) and 'non-healing sole ulcer' (nhSU), which are disorders that involve penetration through the horn capsule to involve the corium. In this study, these non-healing disorders (n=44) were identified as foot lesions that exhibited a topical granular appearance, exuded a typical pungent smell, were severely painful to the animal involved, and typically originated from farms where BDD is endemic. Given the similarities between these 'non-healing' lesions and BDD, the authors subjected samples of diseased tissue to PCR assays to detect the presence of DNA of BDD treponemes. All the three characterised BDD treponeme groups were identified as present together in 84.2, 81.3 and 55.6 per cent of samples of TN (n=19), nhWLD (n=16) and nhSU (n=9), respectively. In contrast, healthy control horn samples from similar sites (n=16) were PCR-negative for the BDD treponemes. Hence, these non-healing hoof lesions were strongly associated with BDD treponemes. Samples from typical heel horn erosions (n=9) were also subjected to BDD treponeme PCR assays and no association could be identified between the BDD treponemes and this horn manifestation.

Comparison of treatment and outcome information between a clinical trial and the National Cancer Data Repository

BACKGROUND

Clinical trials are important but many factors limit their success, including the costs of long-term follow-up and participants often not being representative of the general population. The National Cancer Data Repository (NCDR) contains data about patients with cancer in England that may help overcome some of these problems. This study compared treatment and outcome information between the Medical Research Council Conventional versus Laparoscopic-Assisted Surgery in Colorectal Cancer (CLASICC) trial and the NCDR.

METHODS

Participants in the CLASICC trial were identified in the NCDR, and management and outcome data were compared. Data on all surgically treated English patients with colorectal cancer were extracted from the NCDR and compared with those of CLASICC participants.

RESULTS

Survival and treatment data for those in the CLASICC trial were available in the NCDR for 98·9 and 95·8 per cent of patients respectively. There was agreement in operation type for 86·1 per cent of patients but surgical approach coding was poor, with only 58·4 per cent of laparoscopic procedures coded in the NCDR. There was no significant difference in survival calculated from either data set. Surgical information was available in the NCDR for 19 of 20 trial participants with missing data. The trial population was younger (P < 0·001), of better socioeconomic status (P = 0·001) and with earlier disease (P < 0·001) than the general surgically treated colorectal cancer population. Rectal cancer survival was similar, but 5-year survival after treatment of colonic cancer was significantly better in the trial than in the national data: 57·1 (95 per cent confidence interval 51·5 to 62·3) versus 49·8 (49·3 to 50·2) per cent respectively.

CONCLUSION

The National Cancer Data Repository demonstrates potential for informing clinical trials, but limitations prevent full intention-to-treat analyses.

Bone marrow stromal cells inhibit mast cell function via a COX2-dependent mechanism

BACKGROUND

Mast cells (MCs) have a central role in the induction of allergic inflammation, such as seen in asthma, and contribute to the severity of certain autoimmune diseases, such as rheumatoid arthritis. The MC thus represents an important inflammatory cell, and one which has resisted therapeutic attempts to alter its role in disease.

OBJECTIVE

Because bone marrow-derived stromal cells (BMSC, also known as mesenchymal stem cells or MSCs) have been reported to alter allergic inflammation in vivo, we chose to study the interaction between mouse BMSC and mouse bone marrow-derived MCs.

METHODS

MC degranulation, cytokine production and chemotaxis were evaluated in vitro following co-culture with BMSCs either in cell contact or a transwell. In addition, MC degranulation was assessed in vivo following administration of BMSCs in a model of passive cutaneous anaphylaxis and a peritoneal degranulation assay. Mechanisms of MC suppression by BMSCs were determined through use of inhibitors or antibodies to COX1, COX2, nitric oxide, indoleamine 2, 3-dioxygenase, EP1-4 receptors, TGF-β and IL-10. Lastly, we utilized either BMSCs or MCs deficient in COX1, COX2 or EP1-4 receptors to confirm the mechanisms of inhibition of MC function by BMSCs.

RESULTS

We discovered that BMSCs will effectively suppress specific MC functions in vitro as well as in vivo. When MCs are cocultured with BMSCs to allow cell-to-cell contact, BMSCs suppressed MC degranulation, pro-inflammatory cytokine production, chemokinesis and chemotaxis. Similarly, MC degranulation within mouse skin or the peritoneal cavity was suppressed following in vivo administration of BMSCs. Further, we found that these inhibitory effects were dependent on up-regulation of COX2 in BMSCs; and were facilitated through the activation of EP4 receptors on MCs.

CONCLUSION AND CLINICAL RELEVANCE

These observations support the concept that BMSCs have the ability to suppress MC activation and therefore could be the basis for a novel cell based therapeutic approach in the treatment of MC driven inflammatory diseases.

Bone marrow stromal cells inhibit mast cell function via a COX2-dependent mechanism

BACKGROUND

Mast cells (MCs) have a central role in the induction of allergic inflammation, such as seen in asthma, and contribute to the severity of certain autoimmune diseases, such as rheumatoid arthritis. The MC thus represents an important inflammatory cell, and one which has resisted therapeutic attempts to alter its role in disease.

OBJECTIVE

Because bone marrow-derived stromal cells (BMSC, also known as mesenchymal stem cells or MSCs) have been reported to alter allergic inflammation in vivo, we chose to study the interaction between mouse BMSC and mouse bone marrow-derived MCs.

METHODS

MC degranulation, cytokine production and chemotaxis were evaluated in vitro following co-culture with BMSCs either in cell contact or a transwell. In addition, MC degranulation was assessed in vivo following administration of BMSCs in a model of passive cutaneous anaphylaxis and a peritoneal degranulation assay. Mechanisms of MC suppression by BMSCs were determined through use of inhibitors or antibodies to COX1, COX2, nitric oxide, indoleamine 2, 3-dioxygenase, EP1-4 receptors, TGF-β and IL-10. Lastly, we utilized either BMSCs or MCs deficient in COX1, COX2 or EP1-4 receptors to confirm the mechanisms of inhibition of MC function by BMSCs.

RESULTS

We discovered that BMSCs will effectively suppress specific MC functions in vitro as well as in vivo. When MCs are cocultured with BMSCs to allow cell-to-cell contact, BMSCs suppressed MC degranulation, pro-inflammatory cytokine production, chemokinesis and chemotaxis. Similarly, MC degranulation within mouse skin or the peritoneal cavity was suppressed following in vivo administration of BMSCs. Further, we found that these inhibitory effects were dependent on up-regulation of COX2 in BMSCs; and were facilitated through the activation of EP4 receptors on MCs.

CONCLUSION AND CLINICAL RELEVANCE

These observations support the concept that BMSCs have the ability to suppress MC activation and therefore could be the basis for a novel cell based therapeutic approach in the treatment of MC driven inflammatory diseases.

Five-year follow-up of the Medical Research Council CLASICC trial of laparoscopically assisted versus open surgery for colorectal cancer

INTRODUCTION

The UK Medical Research Council CLASICC trial assessed the safety and efficacy of laparoscopically assisted surgery in comparison with open surgery for colorectal cancer. The results of the 5-year follow-up analysis are presented.

METHODS

Five-year outcomes were analysed and included overall and disease-free survival, and local, distant and wound/port-site recurrences. Two exploratory analyses were performed to evaluate the effect of age (70 years or less, or more than 70 years) on overall survival between the two groups, and the effect of the learning curve.

RESULTS

No differences were found between laparoscopically assisted and open surgery in terms of overall survival, disease-free survival, and local and distant recurrence. Wound/port-site recurrence rates in the laparoscopic arm remained stable at 2.4 per cent. Conversion to open operation was associated with significantly worse overall but not disease-free survival, which was most marked in the early follow-up period. The effect of surgery did not differ between the age groups, and surgical experience did not impact on the 5-year results.

CONCLUSION

The 5-year analyses confirm the oncological safety of laparoscopic surgery for both colonic and rectal cancer. The use of laparoscopic surgery to maximize short-term outcomes does not compromise the long-term oncological results.

REGISTRATION NUMBER

ISRCTN74883561 (http://www.controlled-trials.com).

New limit on Lorentz- and CPT-violating neutron spin interactions

We performed a search for neutron spin coupling to a Lorentz- and CPT-violating background field using a magnetometer with overlapping ensembles of K and ³He atoms. The comagnetometer is mounted on a rotary platform for frequent reversal of its orientation. We measure sidereal oscillations in the signal to search for anomalous spin coupling of extra-solar origin. We determine the equatorial components of the background field interacting with the neutron spin to be b˜Xn=(0.1 ± 1.6) × 10⁻³³ GeV and b˜Yn=(2.5 ± 1.6) × 10⁻³³ GeV, improving on the previous limit by a factor of 30. This measurement represents the highest energy resolution of any spin anisotropy experiment.

How well are graduates prepared for practice when measured against the latest GMC recommendations?

This article investigates the perspectives of University of Liverpool graduate foundation doctors and their consultants on their preparedness for professional practice.

Adhesions and incisional hernias following laparoscopic versus open surgery for colorectal cancer in the CLASICC trial

BACKGROUND

This study investigated adhesive intestinal obstruction (AIO) and incisional hernia (IH) in patients undergoing laparoscopically assisted and open surgery for colorectal cancer.

METHODS

In a case-note review of patients randomized to the Medical Research Council's Conventional versus Laparoscopic-Assisted Surgery In Colorectal Cancer (CLASICC) trial, primary and key secondary endpoints were AIO and IH admission rates respectively.

RESULTS

Of 411 patients, 11 were admitted for AIO: four (3.1 per cent) of 131 patients in the open arm of the trial versus seven (2.5 per cent) of 280 in the laparoscopic arm (difference 0.6 (95 per cent confidence interval (c.i.) - 2.9 to 4.0) per cent). Thirty-six patients developed IH: 12 (9.2 per cent) after open versus 24 (8.6 per cent) after laparoscopic surgery (difference 0.6 (95 per cent c.i. - 5.3 to 6.5) per cent). Results by actual procedure showed higher AIO and IH rates in the 24.5 per cent of patients who converted from laparoscopic to open surgery (AIO: 2.3, 2.0 and 6 per cent; IH: 8.6, 7.4 and 11 per cent-for open, laparoscopic and converted operations respectively).

CONCLUSION

Although this study has not confirmed that laparoscopic surgery reduces rates of AIO and IH after colorectal cancer surgery, trends suggest that a reduction in conversion to open surgery and elimination of port-site hernias may produce such an effect. Registration number for CLASICC trial: ISRCTN74883561 (http://www.controlled-trials.com).

Limits on new long range nuclear spin-dependent forces set with a K-3He comagnetometer

A magnetometer using spin-polarized K and 3He atoms occupying the same volume is used to search for anomalous nuclear spin-dependent forces generated by a separate 3He spin source. We measure changes in the 3He spin precession frequency with a resolution of 18 pHz and constrain anomalous spin forces between neutrons to be less than 2x10(-8) of their magnetic or less than 2x10(-3) of their gravitational interactions on a length scale of 50 cm. We present new limits on neutron coupling to light pseudoscalar and vector particles, including torsion, and constraints on recently proposed models involving unparticles and spontaneous breaking of Lorentz symmetry.

Selective homogenous and heterogeneous catalysis

Catalysis of organic reactions by micellar aggregates in aqueous solution lacks synthetic utility in its present state, largely for two reasons: first, the selectivity attainable in a loose unstructured micelle is low, with little possibility of attaining the degree of substrate differentiation possible in enzymes, and, second, the scale of reaction is limited, since surfactant must be in large excess over reactant to avoid swamping of the catalytic effect. The discussion will cover initial attempts to overcome these drawbacks. Increased selectivity is apparent in the promotion of ester hydrolysis by micelles of asymmetric chain-functionalized surfactants. In the most favourable circumstances 3:1 discrimination in the rate of reaction of ester enantiomers may be observed. Increased scale of reaction is obtainable when polymer-linked cationic surfactants are used as insoluble catalysts, and these hold promise for various anionactivation reas are used as insoluble catalysts, and these hold promise for varous anion-activation reactions. Specific attention is given to mechanistic aspects of homogenous and heterogeneous catalysis.

Antigliadin antibodies in Cuban patients with spinocerebellar ataxia type 2

OBJECTIVE

To evaluate the significance of antigliadin antibodies (AGA) levels for spinocerebellar ataxia type 2.

METHODS

We determined AGA levels in 64 patients with spinocerebellar ataxia type 2 and in 65 healthy matched controls. The clinical assessment was carried out using the International Cooperative Ataxia Rating Scale and CAG repeat number was assessed by PCR.

RESULTS

Antibodies were positive in 23.4% of the ataxia patients and 9.09% of the controls. Statistical comparison using chi2 test with Yates's correction reveals significant differences between these two groups (chi2 = 3.94; p = 0.047). The same was obtained for strongly positive AGA (chi2 = 4.62; p = 0.032). There were no significant differences between AGA positive and AGA negative patients in age at onset, disease duration, ataxia score or CAG repeat number, neither in the prevalence of gastrointestinal symptoms, prevalence of wheat intolerance or body weight.

CONCLUSIONS

These results demonstrate an association between antigliadin antibodies serum levels and SCA2. However, more work has to be done to clarify the clinical consequences of such an association.

Patient factors influencing conversion from laparoscopically assisted to open surgery for colorectal cancer

BACKGROUND

Intraoperative conversion from laparoscopically assisted to open surgery for colorectal cancer is thought to be influenced by several patient factors. Analysis of the Conventional versus Laparoscopic-Assisted Surgery In Colorectal Cancer (CLASICC) Trial data aimed to identify these risk factors.

METHODS

Of 488 laparoscopically assisted procedures attempted, 143 (29.3 per cent) were converted to open operation. Patient factors considered in multivariable analyses were age, sex, previous abdominal incisions, body mass index (BMI), tumour site, tumour diameter, pathological tumour (pT) and pathological node (pN) stage, extent of tumour spread from the muscularis propria, liver and peritoneal metastases, and American Society of Anesthesiologists (ASA) grade. As BMI was missing for 30.7 per cent of patients, two approaches were employed: one considered BMI as a possible risk factor and one did not.

RESULTS

When BMI was taken into consideration, male sex (odds ratio (OR) 2.07; P = 0.020), BMI (OR 1.10; P = 0.006) and extent of tumour spread from the muscularis propria (OR 1.08; P < 0.001) were independent predictors of conversion. When BMI was not considered, extent of tumour spread (OR 1.07; P < 0.001) and male sex (OR 2.05; P = 0.004) were again identified, as were tumour site (OR 2.11; P = 0.005) and ASA grade (II versus I, OR 0.92; III versus I, OR 2.74; P = 0.012).

CONCLUSION

Intraoperative conversion is more likely with larger BMI, in men, patients with rectal cancer, those graded ASA III or when there is greater local tumour spread.

Escherichia coli in household drinking water and diarrheal disease risk: evidence from Cambodia

Escherichia coli counts in household drinking water may or may not reliably indicate the presence of diarrheogenic pathogens originating in feces. The extent to which a bacterial indicator like E. coli predicts risks from all classes of pathogens (viruses and parasites as well as bacteria), especially in tropical waters, is uncertain. To investigate the association between E. coli in household drinking water and diarrheal diseases in Cambodia, we conducted a 22 week cohort study in a rural village in Kandal Province. Episodes of diarrhea (all) and bloody diarrhea (dysentery), water quality, water sources, and other covariates were monitored biweekly in 180 households. Households used a variety of water treatment, storage, and handling practices.Results suggest a weak but positive association between E. coli counts in household drinking water and diarrhea and for diarrhea with blood (dysentery), after adjusting for clustering within households and within individuals over time. Compared to households with <1 E. coli/100 ml in drinking water, there was no observed increased risk for having 1-10 E. coli/100 ml (LPR = 0.98, 95% CI 0.81-1.2 for diarrheal disease; LPR = 0.75, 95% CI 0.36-1.6 for dysentery). Households with measured E. coli of 11-100/100 ml did report increased diarrhea (LPR = 1.2, 95% CI 1.1-1.3 for diarrheal disease; LPR = 1.4, 95% CI 1.0-1.8 for dysentery), as did those with 101-1,000 E. coli/100 ml (LPR = 1.2, 95% CI 1.2-1.3 for diarrheal disease; LPR = 1.2, 95% CI 1.0-1.4 for dysentery) and those with >1,000 E. coli per 100 ml sample (LPR = 1.2, 95% CI 1.1-1.2 for diarrheal disease; LPR = 1.2, 95% CI 1.0-1.3 for dysentery). Unlike the results of some previous studies, diarrheal disease risks did not increase progressively in magnitude with increasing concentration of E. coli in drinking water.

Timing of breast cancer surgery in relation to menstrual cycle phase: no effect on 3-year prognosis: the ITS Study

The effect of breast cancer surgery timing during the menstrual cycle on prognosis remains controversial. We conducted a multicentre prospective study to establish whether timing of interventions influences prognosis. We report 3-year overall and disease-free survival (OS/DFS) results for ‘primary analysis’ patients (regular cycles, no oral contraceptives within previous 6 months). Data were collected regarding timing of interventions in relation to patients’ last menstrual period (LMP) and first menstrual period after surgery (FMP). Hormone profiles were also measured. Cox's proportional hazards model incorporated LMP in continuous form. Exploratory analyses used menstrual cycle categorisations of Senie, Badwe and Hrushesky. Hormone profiles with LMP and FMP data were also used to define menstrual cycle phase. Four hundred and twelve ‘primary analysis’ patients were recruited. Three-year OS from first surgery was 90.7, 95% confidence interval (CI) [87.9, 93.6%]. Menstrual cycle according to LMP was not statistically significant (OS: hazard ratio (HR)=1.02, 95%CI [0.995,1.042], P=0.14; DFS: HR=1.00, 95%CI [0.980,1.022], P=0.92). Timing of surgery in relation to menstrual cycle phase had no significant impact on 3-year survival. This may be due to 97% of patients receiving some form of adjuvant therapy. Survival curves to 10 years indicate results may remain true for longer-term survival.

The mast cell and allergic diseases: role in pathogenesis and implications for therapy

Mast cells have long been recognized for their role in the genesis of allergic inflammation; and more recently for their participation in innate and acquired immune responses. Mast cells reside within tissues including the skin and mucosal membranes, which interface with the external environment; as well as being found within vascularized tissues next to nerves, blood vessels and glandular structures. Mast cells have the capability of reacting both within minutes and over hours to specific stimuli, with local and systemic effects. Mast cells express the high affinity IgE receptor (FcepsilonRI) and upon aggregation of FcepsilonRI by allergen-specific IgE, mast cells release and generate biologically active preformed and newly synthesized mediators which are involved in many aspects of allergic inflammation. While mast cells have been well documented to be essential for acute allergic reactions, more recently the importance of mast cells in reacting through pattern recognition receptors in innate immune responses has become recognized. Moreover, as our molecular understanding of the mast cell has evolved, novel targets for modulation have been identified with promising therapeutic potential.