Preclinical identification of biomarkers of response to mTOR inhibitors and subsequent application in a phase II trial of sirolimus in pancreatic cancer patients refractory to gemcitabine

4612

Background: Treatment for advanced pancreatic cancer refractory to gemcitabine has not been defined. We conducted an efficacy study in pancreatic cancer xenografts to identify biomarkers of response to mTOR inhibition and attempted to translate the results by conducting a phase II trial of sirolimus in this patient population. Methods: 19 direct pancreatic xenografts were treated with temsirolimus (20mg/Kg IP daily) for 28 days. Tumors were profiled with array CGH and gene expression arrays at baseline. TGI were calculated at 28 days. Patients refractory to gemcitabine were included in the clinical trial. Sirolimus was administered at 5mg/day for 28 days. Primary endpoint was 6 month survival rate (6mSR). Secondary endpoints included: baseline evaluation of AKT pathway activation, pharmacodynamic assessment of p-S6K in PBMC, pharmacokinetics and toxicity analysis. Results: In the preclinical study, mTOR sensitive tumors showed upregulation of genes involved in the renal cell cancer pathway. CGH identified focal gains in N-Ras and K-Ras and homozygous deletions of FHIT in sensitive cases. Overall, these genetic changes induced AKT pathway activation, and led us to explore high baseline p-S6K expression as a predictor of outcome in the clinical phase. Patient characteristics: Median age: 64 (39–77). 11 patients had received ≥ 2 prior lines of chemotherapy. 6mSR was 20%. 6mSR in the subgroup of patients who received rapamycin as first line chemotherapy after progression to gemcitabine was 34%. Baseline tumor p-S6K was not predictive for survival. Early pharmacodynamic changes in p-S6K in PBMC 6 hours after treatment initiation were correlated with survival (R2= 0.65). Treatment was well tolerated. The most common grade 3 adverse event was hyperglycemia in 10% of the patients. 7 (23%) patients achieved stable disease. Conclusions: Rapamycin is well tolerated in this setting. Early pharmacodynamic changes in p-S6K in PBMC were correlated with survival. Preclinical findings leading to activation of the AKT pathway in all sensitive cases warrants further validation studies. Efficacy data is limited by the selection of a heavily pretreated and poor prognosis population (DFS≤47 days).

No significant financial relationships to disclose.

Efficacy comparison between intraportal and subcapsular islet transplants in a murine diabetic model

BACKGROUND

It is important to determine the efficacy of intraportal (IP) islet transplantation in comparison with other transplant sites. In this study, we sought to determine the optimal number of islets to achieve normoglycemia following transplantation into the liver versus the kidney using a mouse model.

METHODS

Streptozotocin-induced diabetic mice (Balb/C) were transplanted with syngeneic islets via the IP versus renal subcapsular (SC) routes. The transplanted islet numbers were 0 to 800 (n = 3-5). We assessed the correlation between parameters and islet numbers, comparing IP versus SC groups. The parameters were: (1) percentage of normoglycemia; (2) postoperative days to normoglycemia; (3) mean blood glucose levels at various points from pretransplantation to the end of the study (postoperative day 28); (4) mean serum insulin; and (5) area under the curve of blood glucose levels after glucose injection.

RESULTS

Two hundred islets yielded normoglycemia in renal subcapsular grafts, while 800 islets were the minimum required for normoglycemia with IP transplantation. The transplant efficacy in SC transplantation was 2 to 5 times greater than that of IP transplantation. The days to normoglycemia were significantly different between IP versus renal SC islets (13.25 +/- 4.38 days vs 4.50 +/- 0.81 days; P = .007).

CONCLUSION

The efficacy of islet transplantation in murine diabetic models was significantly greater under the kidney capsule. Clinical islet transplantation could benefit from trials of alternative transplant sites.

Juvenile hormone regulation of male accessory gland activity in the red flour beetle, Tribolium castaneum

Male accessory gland proteins (Acps) act as key modulators of reproductive success in insects by influencing the female reproductive physiology and behavior. We used custom microarrays and identified 112 genes that were highly expressed in male accessory glands (MAG) in the red flour beetle, Tribolium castaneum. Out of these 112 identified genes, 59 of them contained sequences coding for signal peptide and cleavage site and the remaining 53 contained transmembrane domains. The expression of 14 of these genes in the MAG but not in other tissues of male or female was confirmed by quantitative real-time PCR. In virgin males, juvenile hormone (JH) levels increased from second day post adult emergence (PAE), remained high on third day PAE and declined on fourth day PAE. The ecdysteroid titers were high soon after adult emergence but declined to minimal levels from 1 to 5 days PAE. Feeding of juvenile hormone analog, hydroprene, but not the ecdysteroid analog, RH-2485, showed an increase in size of MAGs, as well as an increase in total RNA and protein content of MAG. Hydroprene treatment also increased the expression of Acp genes in the MAG. RNAi-mediated knock-down in the expression of JHAMT gene decreased the size of MAGs and expression of Acps. JH deficiency influenced male reproductive fitness as evidenced by a less vigor in mating behavior, poor sperm transfer, low egg and the progeny production by females mated with the JH deficient males. These data suggest a critical role for JH in the regulation of male reproduction especially through MAG secretions.

Neuroglycopenia and adrenergic responses to hypoglycaemia: insights from a local epidemic of serendipitous massive overdose of glibenclamide

AIMS

Recently, an unlicensed aphrodisiac formulation originating from China known as 'Power 1 Walnut' penetrated the illicit markets of South East Asia including Singapore. Subsequent toxicological analyses revealed that each 'Power 1 Walnut' pill was illegally adulterated with two prescription drugs--sildenafil 1 mg (a PDE5 inhibitor) and glibenclamide 93-98 mg (a long-acting sulphonylurea). As the drug was peddled to numerous people, a local 'hypoglycaemia epidemic' ensued, of which a small cluster presented to our hospital with severe hypoglycaemia. The aim is to characterize the demographics, clinical and labouratory aspects and postulate mechanisms for the relatively atypical presentation.

METHODS

A retrospective study of all the patients admitted between 13th January to 15th June 2008 with hypoglycaemia was done with acquisition of all relevant data after ethical approval from our DSRB.

RESULTS

15 patients (25-73 years old) presented with severe hypoglycaemia. All of them presented with neuroglycopenic symptoms (5-confusion, 6-drowsiness to loss of consciousness, 4-seizures and 1-coma) 12-36 h after ingestion of 'Power 1 Walnut'. Liquid chromatography-mass spectrometry (LC/MS) confirmed the presence of glibenclamide in the urine. None experienced a full-blown hypoglycaemia-associated autonomic response defined as sweating, sensation of warmth, anxiety, tremor, nausea, palpitations, tachycardia, and hunger. Only 4/16 patients had symptoms of a partial autonomic response, and 3/16 patients had tachycardia and/or hypertension.

CONCLUSIONS

The above suggests an inappropriate autonomic and catecholamine response to severe hypoglycaemia in these cases of serendipitous glibenclamide overdose. Possible reasons for the blunted autonomic responses and apparent autonomic failure are reviewed.

An automatic photometric method with high precision by gradually diluting a sample

An automatic photometric method to increase the precision of measurement is proposed, which is based on the injection of a very small volume of sample by rotary valve and the subsequent homogeneous mixing in a small reaction cell made of glass of the sample with a color-developing reagent gradually delivered by a syringe piston pump until the absorbance of the mixture approaches 0.434, where the lowest relative error in the concentration locates. This photometric method is characteristic of uniformly high precision, low sample and reagent consumption, and high sampling rate of 30 samples per h. The other advantages of this method include easy calibration with only one standard solution and no strict requirements on photometric components. While applied for the determination of cobalt ranging from 0.21 to 1.43 g 1(-1), the relative standard deviations are all below 0.4%.

Amebic cerebral abscess mimicking bacterial meningitis

We report a case of an amebic brain abscess in a 2-year-old girl, with symptoms mimicking bacterial meningitis with no evidence of disease elsewhere. Histological evaluation of the abscess revealed the organisms, and the abscess regressed in response to specific medical treatment. This article reviews the rarity of these abscesses and difficulty in the diagnosis.

Meta-analysis of holmium laser enucleation versus transurethral resection of the prostate for symptomatic prostatic obstruction

BACKGROUND

Holmium laser enucleation (HoLEP) is an alternative to transurethral resection (TURP) of the prostate for symptomatic prostatic obstruction.

METHODS

Randomized controlled trials comparing HoLEP and TURP were identified systematically using Medline, Embase and The Cochrane Library. Primary outcomes were peak urinary flow rate (Qmax), postvoid residual volume, symptom score and quality of life. Secondary outcomes were duration of operation, hospital stay, blood loss, catheterization time and adverse events.

RESULTS

There was no statistically significant difference between HoLEP and TURP in terms of Qmax at 6 and 12 months' follow-up. HoLEP was associated with significantly less blood loss, a shorter catheterization time and a shorter hospital stay. TURP was associated with reduced operating time. The techniques were similar in terms of urethral stricture, stress incontinence, transfusion requirement and rate of reintervention.

CONCLUSION

HoLEP and TURP provide a similar improvement in Qmax. HoLEP, however, has several advantages over TURP, despite requiring more operating time. It is at least as safe as TURP in terms of adverse events.

Transcription factor broad suppresses precocious development of adult structures during larval-pupal metamorphosis in the red flour beetle, Tribolium castaneum

Broad (br), a transcription factor containing the Broad-Tramtrack-Bric-a-brac (BTB) and zinc finger domains was shown to mediate 20-hydroxyecdysone (20E) action and pupal development in Drosophila melanogaster and Manduca sexta. We determined the key roles of br during larval-pupal metamorphosis using RNA interference (RNAi) in a coleopteran insect, Tribolium castaneum. Two major peaks of T. castaneum broad (Tcbr) mRNA, one peak at the end of feeding stage prior to the larvae entering the quiescent stage and another peak during the quiescent stage were detected in the whole body and midgut tissue dissected from staged insects. Expression of br during the final instar larval stage is essential for successful larval-pupal metamorphosis, because, RNAi-mediated knock-down of Tcbr during this stage derailed larval-pupal metamorphosis and produced insects that showed larval, pupal and adult structures. Tcbr dsRNA injected into the final instar larvae caused reduction in the mRNA levels of genes known to be involved in 20E action (EcRA, E74 and E75B). Tcbr dsRNA injected into the final instar larvae also caused an increase in the mRNA levels of JH-response genes (JHE and Kr-h1b). Knock-down of Tcbr expression also affected 20E-mediated remodeling of midgut during larval-pupal metamorphosis. These data suggest that the expression of Tcbr during the final instar larval stage promotes pupal program while suppressing the larval and adult programs ensuring a transitory pupal stage in holometabolous insects.

The Year of the Salmonella Seekers-1977

In 1977 two major outbreaks of salmonella infection originated in Victoria. The first of these, involving Salmonella Bredeney, continued over some seven months and was traced to contamination of powdered milk-based infant formulae during manufacture. This caused cases of gastroenteritis among young children throughout Australia. Another incident led to the discovery that salmonella serovars were colonising not one, but a number of dairy factories through the State. The second outbreak was of typhoid, stemming from a carrier working in a sandwich bar, and occurred during the course of the first, almost overwhelming public health resources and delaying investigation of the first outbreak. The background, recognition, course, investigation and resolution of these, previously unpublished, outbreaks are described, drawing upon the experiences of authors involved at the clinical, public health and laboratory levels, and preserved, contemporary records. Taken together, these outbreaks directly stimulated radical improvements in the construction and management of dairy factories in the State; initiated the adoption of risk management concepts in food factories; caused the launch of regional regulations compelling notification of salmonellas found in food manufacture; and led to the setting-up of an enhanced national, laboratory-based system for the collection, analysis and dissemination of information on enteric pathogens.

Performance comparison of 40 Gb/s ULH transmissions using CSRZ-ASK or CSRZ-DPSK modulation formats on UltraWave fiber (TM) fiber

In this work we present extensive comparisons between numerical modelling and experimental measurements of the transmission performance of either CSRZ-ASK or CSRZ-DPSK modulation formats for 40-Gb/s WDM ULH systems on UltraWave(TM) fiber spans with all-Raman amplification. We numerically optimised the amplification and the signal format parameters for both CSRZ-DPSK and CSRZ-ASK formats. Numerical and experimental results show that, in a properly optimized transmission link, the DPSK format permits to double the transmission distance (for a given BER level) with respect to the ASK format, while keeping a substantial OSNR margin (on ASK modulation) after the propagation in the fiber line. Our comparison between numerical and experimental results permits to identify what is the most suitable BER estimator in assessing the transmission performance when using the DPSK format.

Levetiracetam for the treatment of hot flashes: A pilot study

9116

Background: Hot flashes affect 75 % to 90 % of women transitioning to menopause and are a major cause of morbidity among breast cancer survivors. Levetiracetam, a popular anticonvulsant, is a centrally active agent that anecdotally appeared to reduce hot flashes in clinical practice. This phase II trial sought to evaluate the efficacy of levetiracetam in reducing hot flashes among women with a history of breast cancer or women who did not wish to take estrogen therapy for fear of an increased risk of breast cancer. Methods: Women who were experiencing bothersome hot flashes (≥ 14 times per week, for ≥ 1 month) were eligible. A single arm pilot study design based on previous work was used with a planned sample size of 30 patients. The patients did not receive any study medication during the first week (baseline week). At the beginning of the second week, patients were started on levetiracetam (500 mg), and were to increase the dose by 500 mg each week to a goal of 1,000 mg twice daily. Hot flash diaries were completed daily. The primary endpoint was hot flash score (frequency times average severity). The change from week 1 (baseline) to week 5, the last treatment week, was analyzed by paired t-test and related Wilcoxon procedures. Results: A total of 30 women were enrolled onto this study in eight months. All patients were eligible. 19 women completed all 4 weeks of the study treatment and provided complete data. After treatment with levetiracetam for 4 weeks, mean hot flash scores were reduced by 57% (95% CI 39%-75%), while mean hot flash frequencies were reduced by 53% (95% CI 38%-68%), reductions being greater than what would be expected with a placebo. There were significant improvements, compared to baseline week data, in sweating, hot flash distress, and satisfaction with hot flash control. Eight subjects stopped the study drug due to treatment related adverse events (grade I/II), with the most frequently reported being somnolence, fatigue and dizziness. Conclusions: While levetiracetam appears to be a promising therapy for the treatment of hot flashes, further study is needed to better substantiate the toxicity and efficacy of this drug before it can be more definitively recommended for use in clinical practice.

No significant financial relationships to disclose.

Phase I clinical and pharmacokinetic (PK) trial of the kinesin spindle protein (KSP) inhibitor MK-0731 in patients with solid tumors

2548

Background: KSP is essential for the separation of spindle poles during mitosis and inhibition results in mitotic arrest. MK- 0731 is a potent inhibitor of KSP, with an IC50 of 2.2 nM, and >20,000 fold selectivity against other kinesins. MK-0731 causes mitotic arrest with an EC50 in several tumor cell lines of 3–5 nM. Methods: Phase I study to determine the safety and tolerability, MTD, and PK of MK-0731 administered IV over 24 hrs every 21 days. In part 1, dosing started at 6 mg/m2/24 hr and was escalated until the MTD was reached. In part 2, pts with measurable taxane-resistant cancer were treated at the MTD established in Part 1 (target accrual =22 pts in part 2). Interim Results: 35 pts with solid tumors (M/F 23/12), median age 63 yrs (23 - 79), were treated at doses of 6 to 48 mg/ m2/24hrs (median cycles 3, range 1–10, total cycles=128). Frequent tumor types included prostate (8), ovarian (4), colon (3), bladder (2), neuroendocrine (2), lung (2), breast (2). Prolonged (>5 days) grade 4 neutropenia was observed in 2 pts at 48 mg/m2/24hrs (11 days duration) and 2 pts at 24 mg/m2/24hrs (7 days duration) leading to expansion of cohorts at lower dose levels. At the MTD of 17 mg/ m2/24, there were no DLTs. 14 patients have been enrolled at the MTD in part 2 of the study. Drug related grade 3/4 toxicities were anemia (1), AST (1), hyperglycemia (1), nausea/vomiting (1), neutropenia (7), syncope (1). PK results from the first 20 patients suggest that MK- 0731 concentrations appear to decline monoexponentially or biexponentially following the infusion with terminal t1/2 from ∼4 to 22 hrs. In some patients, steady-state concentrations may not be achieved by the end of the 24 hr infusion. Mean values at the 17 mg/m2/24hrs dose level were Cmax=599 nM, AUC8=14.56 μM·hr, and CL=119 mL/min. AUC, exposures, and end of infusion concentrations appear to increase proportionally with dose. Stable disease for = 4 cycles (range 4- 10) was seen in 16 patients. Conclusion: Treatment with MK-0731 at the MTD of 17 mg/m2/day every 21 days in patients with advanced solid tumors was well tolerated with consistent dose limiting toxicity of myelosuppression.

No significant financial relationships to disclose.

Phase I study of the safety and pharmacokinetics (PK) of paclitaxel or paclitaxel with carboplatin administered in combination with pazopanib (GW786034)

14118

Background: Pazopanib is a potent and selective multi-targeted receptor tyrosine kinase inhibitor of VEGFR-1, VEGFR-2, VEGFR-3, PDGFR-a/β, and c-kit. Pazopanib also is a moderate inhibitor of CYP2C8 and CYP3A4 in vitro. Paclitaxel (T), a substrate for CYP2C8 and CYP3A4, administered alone and in combination with carboplatin (Cb) is highly active in breast, NSCLC, and ovarian cancers. The additive benefit of the anti-VEGF agent bevacizumab with T or T-Cb in breast and NSCLC provides strong rationale for use of a multi-targeted TKI with T or T-Cb. Methods: Pts with advanced cancer (ECOG PS 0–1) were eligible. Dose escalation was split into Part 1 [T (15–80 mg/m2) days 1, 8, 15 q 28 days plus pazopanib (400–800 mg) QD starting on day 2 of cycle 1] and Part 2 [T (80- 225 mg/m2) plus Cb AUC 6 q 21 days plus pazopanib 800 mg QD starting on day 2 of cycle 1]. Safety, PK, and clinical response were evaluated. Dose escalation occurred in cohorts of 3–6 pts based on dose-limiting toxicities (DLTs) and PK. Results: 12 pts in Part 1 received the following pazopanib/T doses (n = pts): 400 mg/15 mg/m2 (3), 800 mg/15 mg/m2 (3), 800mg /50 mg/m2 (3), 800mg /80 mg/m2 (3). Preliminary data were available from 9 pts in Part 1. Selected mean PK results for T are shown. 4 pts in Part 2 received 800mg /175 mg/m2/AUC 6 of pazopanib/T/Cb (data not yet available). Most common AEs (>20%) in Part 1 were Gr 1/2 and consisted of fatigue, diarrhea, anorexia, nausea, vomiting, dysgeusia, AST elevation, rash, hypertension, and cough; Gr 3 diarrhea was reported in 1 pt. The 800mg pazopanib/80 mg/m2 T cohort in Part 1 is being expanded to 6 pts due to a DLT (dose delay of > 2 wks due to an abscess). Best response (n=6 pts) in Part 1 was SD (83%) (range 1–5 cycles). Conclusions: Concomitant administration of pazopanib increased paclitaxel mean Cmax and AUC(0–8) approximately 20–35%. Determination of the MTR in Parts 1 and 2 is ongoing. These findings warrant further studies at therapeutic doses of pazopanib, paclitaxel, and carboplatin. [Table: see text]

No significant financial relationships to disclose.

A phase I study of R547, a novel, selective inhibitor of cell cycle and transcriptional cyclin dependent kinases (CDKs)

3528

Background: R547, a potent inhibitor of CDKs 1, 2, 4, 7, and 9, has shown broad antitumor activity in preclinical models. This phase Ia study assessed safety, pharmacokinetic (PK), and pharmacodynamic (PD) endpoints. Methods: R547 given as a 90 or 180 min infusion D1, D8 (21 day cycle). Key inclusion criteria: ECOG 0–2, adequate hematologic, hepatic, and renal function. Exclusion: brain metastases, NYHA III/IV CHF, CVA, current antihypertensive therapy. Blood samples on cycle 1, D1, D8 for PK and PD. PD endpoint is inhibition of retinoblastoma phosphorylation (pRB) in PBMCs. Results: 41 pts received R547 over dose range 8.6 - 195 mg/m2; 31 pts on 90 min and 10 pts on 180 min schedule. Mean age 53.4 yrs (20–81), 25F:16M. Mean R547 cycles 3.1(<1- 8) for 18 evaluable pts receiving doses ≥ 155 mg/m2. Toxicities: principal related events were nausea (54%), fatigue (34%), emesis (34%), headache (34%), and hypotension (32%). All of these limited to gr 1/ 2, except 4 gr 3 fatigue (1 in cycle 1) and 1 gr 3 nausea. DLTs: 90 min- gr 3 somnolence, gr 3 confusion, gr 3 fatigue, 1 pt each, all at 195 mg/m2; 180 min- 1 DLT of prolonged gr 3 pruritis at 195 mg/m2. PK: Mean AUC for 20 pts with PK receiving ≥ 155 mg/m2 R547 exceeds exposures efficacious in xenograft studies. At equivalent doses, the 180 min schedule produces equivalent AUC but 30% reduction of Cmax. PD: for pts with available data (n=21), an exposure-dependent decrease in pRB/total RB ratio was observed 1.5 to 24 hrs post R547. Activity: tumor regression in 1 pt with metastatic squamous ca skin; 8 additional pts received ≥ 4 cycles. Conclusions: Treatment with R547 is tolerable at a dose of 155 mg/m2 on D1, D8 (21 day cycle) for both 90 and 180 min schedules. Nausea, emesis, headache, and transient hypotension are manageable with anti-emetic, analgesic, and iv fluid support. The DLTs observed in the 90 min schedule have not occurred in pts receiving 180 min infusions, a schedule which maintains R547 exposure but reduces Cmax. Exposures predictive of preclinical efficacy have been achieved. Inhibition of a relevant PD marker (pRB) and antitumor activity have each been confirmed in the clinic. Phase II trials in advanced solid tumors and hematologic malignancies are planned.

No significant financial relationships to disclose.

Medication safety in cancer clinical trials: An analysis of medication error reports at a comprehensive cancer center

6547

Background: Although medication errors comprise 10–25% of all medical errors, little is known concerning the occurrence or types of medication errors occurring while treating patients on a clinical trial. Therefore, we retrospectively reviewed the medication errors reported in patients enrolled on clinical trials at our center. Methods: As part of a multidisciplinary continuous quality improvement project, from January 2003 through December 2006, we collected voluntary reports of medication errors in adult and pediatric patients on clinical trials involving both oral and intravenous chemotherapy. All reports were classified prospectively regarding clinical trial involvement, severity category (A to I) per the National Coordination Council on Medical Error Reporting and Prevention, type, cause, and where in the medication use process the error occurred. Results: There were 163 reports involving patients treated on clinical trials. The most common errors were those corrected prior to reaching the patient in 68% of events (Category A&B), while 31% reached the patient but did not result in harm (Category C&D), with 1% resulting in temporary patient harm (Category E&F). The most common type of errors were prescribing (66%), improper dose (42%), and omission errors (9%). Not following an institutional procedure or the protocol was the primary cause for these errors (39%), followed by the written order (30%), and poor communication involving both the healthcare team and the patient (26%). The processes where the errors initiated were in prescribing 47%, administration 10%, dispensing 6%, and monitoring 5%. Conclusion: Medication errors do occur in clinical trials, however the majority of these are corrected prior to reaching the patient or do not result in harm. Not following an institutional procedure or the protocol was the most common cause of error. This is most likely due to the protocol procedures differing from existing standards of care. Protocol-specific education through the Centralized Education and Training Service, a shared resource within our cancer center, addresses this issue enhancing the quality and safety of clinical trials through the education and training of healthcare professionals.

No significant financial relationships to disclose.

New insights into image processing of cortical blood flow monitors using laser speckle imaging

Laser speckle imaging has increasingly become a viable technique for real-time medical imaging. However, the computational intricacies and the viewing experience involved limit its usefulness for real-time monitors such as those intended for neurosurgical applications. In this paper, we propose a new technique, tLASCA, which processes statistics primarily in the temporal direction using the laser speckle contrast analysis (LASCA) equation, proposed by Briers and Webster. This technique is thoroughly compared with the existing techniques for signal processing of laser speckle images, including, the spatial-based sLASCA and the temporal-based modified laser speckle imaging (mLSI) techniques. sLASCA is an improvement of the basic LASCA technique. In sLASCA, the derived contrasts are further averaged over a predetermined number of raw speckle images. mLSI, on the other hand, is the technique in which temporal statistics are processed using the equation described by Ohtsubo and Asakura. tLASCA preserves the original image resolution similar to mLSI. tLASCA outperforms sLASCA (window size M = 5) with faster convergence of K values (5.32 versus 20.56 s), shorter per-frame processing time (0.34 versus 2.51 s), and better subjective and objective quality evaluations of contrast images. tLASCA also outperforms mLSI with faster convergence of K values (5.32 s) compared to N values (10.44 s), shorter per-frame processing time (0.34 versus 0.91 s), smaller intensity fluctuations among frames (8%-10% versus 15%-35%), and better subjective and objective quality evaluations of contrast images. As laser speckle imaging becomes an important tool for real-time monitoring of blood flows and vascular perfusion, tLASCA is proven to be the technique of choice.

Incorporation of somatic BRAF mutation testing into an algorithm for the investigation of hereditary non-polyposis colorectal cancer

Patients suspected on clinical grounds to have hereditary non-polyposis colorectal cancer (HNPCC) may be offered laboratory testing in order to confirm the diagnosis and to facilitate screening of pre-symptomatic family members. Tumours from an affected family member are usually pre-screened for microsatellite instability (MSI) and/or loss of immunohistochemical expression of mismatch repair (MMR) genes prior to germline MMR gene mutation testing. The efficiency of this triage process is compromised by the more frequent occurrence of sporadic colorectal cancer (CRC) showing high levels of MSI (MSI-H) due to epigenetic loss of MLH1 expression. Somatic BRAF mutations, most frequently V600E, have been described in a significant proportion of sporadic MSI-H CRC but not in HNPCC-associated cancers. BRAF mutation testing has therefore been proposed as a means to more definitively identify and exclude sporadic MSI-H CRC cases from germline MMR gene testing. However, the clinical validity and utility of this approach have not been previously evaluated in a familial cancer clinic setting. Testing for the V600E mutation was performed on MSI-H CRC samples from 68 individuals referred for laboratory investigation of suspected HNPCC. The V600E mutation was identified in 17 of 40 (42%) tumours showing loss of MLH1 protein expression by immunohistochemistry but in none of the 28 tumours that exhibited loss of MSH2 expression (P < 0.001). The assay was negative in all patients with an identified germline MMR gene mutation. Although biased by the fact that germline testing was not pursued beyond direct sequencing in many cases lacking a high clinical index of suspicion of HNPCC, BRAF V600E detection was therefore considered to be 100% specific and 48% sensitive in detecting sporadic MSI-H CRC amongst those cases showing loss of MLH1 protein expression, in a population of patients with MSI-H CRC and clinical features suggestive of HNPCC. Accordingly, we recommend the incorporation of BRAF V600E mutation testing into the laboratory algorithm for pre-screening patients with suspected HNPCC, whose CRCs show loss of expression of MLH1. In such tumours, the presence of a BRAF V600E mutation indicates the tumour is not related to HNPCC and that germline testing of MLH1 in that individual is not warranted. We also recommend that in families where the clinical suspicion of HNPCC is high, germline testing should not be performed on an individual whose CRC harbours a somatic BRAF mutation, as this may compromise identification of the familial mutation.

Molecular features of astrovirus associated with a gastroenteritis outbreak in an aged-care centre

The study presented here was conducted in order to gain a better understanding of the role of astroviruses (AsVs) in outbreaks of gastroenteritis among the elderly. This report is the first to provide detailed information on the molecular characteristics of an AsV causing an outbreak in an aged-care centre and is the first to clearly establish that individuals infected in such an outbreak were, in fact, elderly. The outbreak under investigation took place in Victoria, Australia, in October 2005. Twelve individuals (mean age +/- standard deviation [SD] 85.5 +/- 12.3 years) became ill during the outbreak from a total population of 86 susceptible residents. The mean duration (+/-SD) of illness was 2.3 +/- 1.6 days; symptoms included diarrhoea, abdominal pain, nausea and headache. No bacterial pathogens were detected. AsV was identified in five faecal specimens using electron microscopy and reverse transcription-polymerase chain reaction methodologies; no other gastroenteritis virus was detected. Nucleotide sequence analysis indicated the AsV identified could be assigned to the 1d lineage of AsV serotype 1 and that the AsV was not a recombinant form. The findings, taken together with previous work, indicate the AsV serotype most commonly associated with gastroenteritis outbreaks among the elderly is serotype 1 AsV.