Nuclear PTEN controls DNA repair and sensitivity to genotoxic stress

Loss of function of the phosphatase and tensin homolog deleted on chromosome 10 (PTEN) tumor suppressor gene is associated with many human cancers. In the cytoplasm, PTEN antagonizes the phosphatidylinositol 3-kinase (PI3K) signaling pathway. PTEN also accumulates in the nucleus, where its function remains poorly understood. We demonstrate that SUMOylation (SUMO, small ubiquitin-like modifier) of PTEN controls its nuclear localization. In cells exposed to genotoxic stress, SUMO-PTEN was rapidly excluded from the nucleus dependent on the protein kinase ataxia telangiectasia mutated (ATM). Cells lacking nuclear PTEN were hypersensitive to DNA damage, whereas PTEN-deficient cells were susceptible to killing by a combination of genotoxic stress and a small-molecule PI3K inhibitor both in vitro and in vivo. Our findings may have implications for individualized therapy for patients with PTEN-deficient tumors.

Nuclear PTEN controls DNA repair and sensitivity to genotoxic stress

Loss of function of the phosphatase and tensin homolog deleted on chromosome 10 (PTEN) tumor suppressor gene is associated with many human cancers. In the cytoplasm, PTEN antagonizes the phosphatidylinositol 3-kinase (PI3K) signaling pathway. PTEN also accumulates in the nucleus, where its function remains poorly understood. We demonstrate that SUMOylation (SUMO, small ubiquitin-like modifier) of PTEN controls its nuclear localization. In cells exposed to genotoxic stress, SUMO-PTEN was rapidly excluded from the nucleus dependent on the protein kinase ataxia telangiectasia mutated (ATM). Cells lacking nuclear PTEN were hypersensitive to DNA damage, whereas PTEN-deficient cells were susceptible to killing by a combination of genotoxic stress and a small-molecule PI3K inhibitor both in vitro and in vivo. Our findings may have implications for individualized therapy for patients with PTEN-deficient tumors.

Occupational exposure to raw meat: a newly-recognized risk factor for Staphylococcus aureus nasal colonization amongst food handlers

Staphylococcus aureus contaminating raw meat may increase nasal colonization risk for occupationally-exposed food handlers. Food handlers from six catering establishments were nasally sampled for S. aureus and completed a questionnaire on carriage risk factors. Isolates were characterized for antibiotic susceptibility, spa type and, for methicillin-resistant strains, SCCmec type. Of 434 food handlers, 99 (22.8%) were colonized with S. aureus. Five isolates were methicillin-resistant belonging to SCCmec IV (2) and V (3). Resistance to tetracycline (20%), and erythromycin (16%) was high, but <10% to other antibiotics. Spa typing revealed 17% of isolates as t189, with 8% each t127 and t1081. Food handlers ever handling raw meat had a significantly higher colonization risk (OR=2.7; 95% CI: 1.7-4.5), increasing to 3.7 (95% CI: 2.0-6.8) for those always exposed. This is the first report of increased colonization risk in food handlers exposed to raw meat. This occupational hazard may increase infection risk, so improved compliance with workplace hygiene may be required.

Colonization of butchers with livestock-associated methicillin-resistant Staphylococcus aureus

Reports have documented colonization of swine in Europe, North America and more recently in China with livestock-associated methicillin-resistant Staphylococcus aureus (LA-MRSA). Contamination of pig farmers, veterinarians and abattoir workers with these strains has been observed. However, although contamination levels of 10% of retail pork were reported from the Netherlands and Canada, there are limited data of contamination rates of workers handling raw meat. We investigated the rates of MRSA contamination of local butchers working in wet markets, where recently slaughtered pigs are cut up. Nasal swabs collected from 300 pork butchers at markets throughout Hong Kong were enriched in brain heart infusion broth with 5% salt and cultured on MRSASelect(®) . Isolates were confirmed as Staphylococcus aureus and susceptibility testing performed. The presence of mecA was confirmed, SCCmec and spa type determined and relatedness investigated by PFGE. Subjects completed a questionnaire on MRSA carriage risk factors. Seventeen samples (5.6%) yielded MRSA, 15 harbouring SCCmec IVb. Ten strains were t899 (CC9), previously reported from local pig carcasses. Five strains were healthcare associated: SCCmec type II, t701(CC6), colonizing two subjects at the same establishment, and single isolates of t008 (CC8), t002 (CC5) and t123 (CC45). The remaining isolates were t359 (CC97), previously reported from buffaloes, and t375 (CC5), reported from bovine milk. None of these butchers reported recent hospitalization or a healthcare worker in the family. Two had recently received antibiotics, one for a skin infection. Four reported wound infections within the last year. All were exposed to meat for >9 h per day. Carriage of MRSA was higher in butchers than in the general community. Although five strains were probably of healthcare origin, the high incidence of t899 (CC9) suggests that cross-contamination from pork occurs frequently. Washing of hands after touching raw pork is advised.

Preparation of mouse-human chimeric antibody against pancreatic cancer-associated mucin

A murine monoclonal antibody, designated Nd2, was generated using a purified mucin from the human pancreatic cancer cell line SW1990 as the immunogen. Administration of Nd2 into the patients with pancreatic cancer has shown that Nd2 is of clinical use for in vivo diagnostics of pancreatic cancer. In this study, starting with a previously established hybridoma producing Nd2, we have established a transfected cell line expressing a recombinant chimeric Nd2 composed of mouse-derived antigen-binding variable regions and human-derived constant regions. The chimeric Nd2 was shown to bind purified mucin from SW1990 cells with the same dose-response curve as the original Nd2. Immunohistochemical experiments have shown that the reactivity of the chimeric Nd2 in normal and malignant pancreatic tissue is also the same as that of the original Nd2. Replacement of a substantial portion of the mouse protein makes this chimeric Nd2 more promising for clinical application than the original mouse-derived Nd2 because its antigenicity is expected to be reduced.

New radioimmunoassay for pancreatic cancer-associated antigen span-1 with reference to differential-diagnosis and monitoring in pancreatic-cancer

Sera from patients with various malignant benign disorders, as well as from a large number of healthy blood donors (2197). were analyzed with a newly developed SPan-1 coated bead radioimmunoassay. Only 0.9% of the healthy patients had SPan-1 levels above the cut-off value. SPan-1 antigen levels were elevated in 89.2% of sera from pancreatic cancer patients and in 75% of T1 and T2 cancers. High diagnostic accuracy was also recognized in differentiating benign pancreatic diseases from pancreatic cancers. SPan-I levels decreased after pancreatic resection and rose again at recurrence of disease. SPan-1 could be distinguished from other tumor markers such as DU-PAN-2 and OC-125 by competition radioimmunoassays and was elevated in individuals with malignant gastrointestinal diseases who had normal levels of either or both CEA and CA 19-9 antigens. This rapid. reproducible and sensitive assay for SPan-I appears to be a useful procedure for the detection and follow-up of pancreatic cancer.

Immune reconstitution inflammatory syndrome associated with disseminated Mycobacterium sherrisii infection

Mycobacterium sherrisii is a recently described mycobacterium closely related to Mycobacterium simiae. There have been only a few reports of this organism causing disease, predominantly in the setting of HIV with severe immunosuppression. We report the first case of disseminated M. sherrisii associated with immune reconstitution inflammatory syndrome.

Detection of clinical and subclinical tubulo-interstitial inflammation by the urinary CXCL10 chemokine in a real-life setting

Urinary CXCL10 is a promising noninvasive biomarker for tubulo-interstitial allograft inflammation, but its diagnostic characteristics have not been assessed in a real-life setting. We investigated urinary CXCL10 in 213 consecutive renal allograft recipients having 362 surveillance biopsies at 3/6 months and 80 indication biopsies within the first year posttransplant. Allograft histology results were classified as (i) acute Banff score zero, (ii) interstitial infiltrates only, (iii) tubulitis t1, (iv) tubulitis t2-3 and (v) isolated vascular compartment inflammation. For clinical and subclinical pathologies, urinary CXCL10 correlated well with the extent of tubulo-interstitial inflammation. To determine diagnostic characteristics of urinary CXCL10, histological groups were separated into two categories: no relevant inflammation (i.e. acute Banff score zero and interstitial infiltrates only) versus all other pathologies (i.e. tubulitis t1-3 and isolated vascular compartment inflammation). For subclinical pathologies, AUC was 0.69 (sensitivity 61%, specificity 72%); for clinical pathologies, AUC was 0.74 (sensitivity 63%, specificity 80%). A urinary CXCL10-guided biopsy strategy would have reduced performance of surveillance and indication biopsies by 61% and 64%, respectively. Missed (sub)clinical pathologies were mostly tubulitis t1 and isolated vascular compartment lesions. In real life, urinary CXCL10 had clinically useful diagnostic properties making it a candidate biomarker to guide allograft biopsies.

Evolution and clinical pathologic correlations of de novo donor-specific HLA antibody post kidney transplant

The natural history for patients with de novo donor-specific antibodies (dnDSA) and the risk factors for its development have not been well defined. Furthermore, clinical and histologic correlation with serologic data is limited. We studied 315 consecutive renal transplants without pretransplant DSA, with a mean follow-up of 6.2 ± 2.9 years. Protocol (n = 215) and for cause (n = 163) biopsies were analyzed. Solid phase assays were used to screen for dnDSA posttransplant. A total of 47 out of 315 (15%) patients developed dnDSA at a mean of 4.6 ± 3.0 years posttransplant. Independent predictors of dnDSA were HLA-DRβ1 MM > 0 (OR 5.66, p < 0.006); and nonadherence (OR 8.75, p < 0.001); with a strong trend toward clinical rejection episodes preceding dnDSA (OR 1.57 per rejection episode, p = 0.061). The median 10-year graft survival for those with dnDSA was lower than the No dnDSA group (57% vs. 96%, p < 0.0001). Pathology consistent with antibody-mediated injury can occur and progress in patients with dnDSA in the absence of graft dysfunction and furthermore, nonadherence and cellular rejection contribute to dnDSA development and progression to graft loss.

P1-12-25: Evaluation of PTEN, EGFR and Ki67 Expression as Predictors of Response to a Trastuzumab-Containing Neoadjuvant Chemotherapy Regimen in a HER-2 Over-Expressing Locally Advanced Breast Cancer (LABC) Trial

Background: In patients with HER-2 over-expressing breast cancer, predictors of trastuzumab response and resistance remain unclear and unvalidated. In an exploratory analysis within a phase II trial, we evaluated various biologic markers as predictors of response or resistance to a trastuzumab containing neoadjuvant chemotherapy regimen.

Methods: A tissue microarray (TMA) was constructed from formalin-fixed paraffin-embedded tumor tissue samples obtained prior to neoadjuvant chemotherapy in 21 (from a total of 30) HER-2 positive stage II-III patients. Protocol treatment consisted of 4 cycles of 5-Fluorouracil, Epirubicin and Cyclophosphamide (FEC100) followed by 4 cycles of Docetaxel, Carboplatin (AUC 6) and Trastuzumab (TCH). Immunohistochemical (IHC) analyses of estrogen receptor (ER), progesterone receptor (PR), HER-2, Ki67, EGFR and PTEN were performed utilizing previously published protocols and cut-offs. HER-2 equivocal (2+) by IHC cases was confirmed by prior FISH analysis. Fisher's exact test was used for statistical analysis.

Results: 21 patients had sufficient tumour for analysis. Median age at diagnosis was 49 years old, 67% were pre-menopausal, and biomarker expression was as follows: 43% ER positive, 29% PR positive, and 100% HER-2 positive. 14 patients (67%) had pathologic complete response (pCR) following the completion of neoadjuvant chemotherapy and trastuzumab. In general, tumour samples showed high Ki67 (&gt;14%) staining (62%), low EGFR positivity (14%), and high PTEN expression (71%). Neither high Ki67 expression (p=0.65), any EGFR expression (p=0.26), nor PTEN loss (p=0.60) was associated with higher or lower rates of pCR respectively.

Conclusion: In our small cohort of locally advanced HER-2 over-expressing tumours, baseline expression of Ki67, EGFR and PTEN were not associated with pCR to a neoadjuvant sequential anthracycline and taxane/trastuzumab combination regimen. Additional biomarkers for an activated PI3K pathway and for p95 will be attempted.

Citation Information: Cancer Res 2011;71(24 Suppl):Abstract nr P1-12-25.

Effects of buried insulator-sensor interface on the lateral conduction of high fill factor aSi:H imagers

The pixel cross-talk is investigated in two-dimensional amorphous silicon (a-Si:H) imager arrays based on the new high fill factor design. In this configuration a continuous a-Si:H sensor extends over the whole surface of the imager, and a buried insulator material with low dielectric constant is used to separate the sensor from the underlying active matrix readout circuit. We find that the lateral conduction between neighboring pixels is mainly determined by the quality of the buried insulator-sensor interface, rather than the specific buried material itself. Minimum cross-talk values below 1% are obtained for different insulator materials including silicon oxynitride and thicker polymer based resins. The quality of this interface also affects trapping and recombination of the photogenerated carriers, influencing important imager properties such as sensitivity and image lag.

Jet-printed Fabrication of a-Si:H Thin-film Transistors and Arrays

Phase-change wax-based printed masks were used to fabricate a-Si:H thin-film transistors (TFTs) in place of conventional lithography. Wax-mask features with a minimum feature size of ∼20 [.proportional]m was achieved using an acoustic-ink-printing process. Bottom-gate TFTs with source-drain contacts overlapping the channel were created using a four-mask process. The TFTs have I-V characteristics comparable to photolithographically patterned devices, with mobility of 0.6-1 cm2/V·s, threshold voltage of 2-3 V, and on/off ratios exceeding 107, for devices with channel lengths below 50[.proportional]m.

Mixed affective states; a study within a community mental health team with treatment recommendations

Introduction

Agitated Unipolar Depression and Bipolar mixed states combine depressive and manic symptoms, reflecting severe forms of affective disorders with an increased suicide risk. These states have not been defined with adequate consensus and hence present a diagnostic and therapeutic challenge.

Method

We searched the records of patients with Affective Mixed States in a community Mental Health Team to identify patients with affective mixed states.

We assessed the treatments prescribed and the time it took to treat the Mixed states so that they then suffered from depression or were euthymic.

Results

Ten out of 17 patients were suicidal when experiencing a mixed state. Of the 6 patients that were agitated, 5 were suicidal. Best results were achieved with a combination of -Reducing antidepressant -Increasing mood stabilisers (Depakote, Lithium) -Increasing/adding atypical antipsychotics. With such treatment, the average duration to resolution was 2.5 weeks. The worse results were achieved by adding antidepressants to a patient experiencing low mood with a mixed state such treatment led to resolution in 10 weeks

Discussion

Agitation is a strong predictor of suicide risk. Reducing antidepressants is important thus Increasing/adding antipsychotics and mood stabilisers without changing antidepressants led to an 8.5 weeks duration of treatment.

Conclusion

Patients with mixed states should be reviewed regularly and risk-assessed -We suggest weekly due to increased suicide risk. With very high-risk patients, referral should be made to the Crisis Team. Care coordinators should be involved for regular contact with services.

Evaluation of the association of matrix metalloproteinase-1 (MMP-1) and matrix metalloproteinase-2 (MMP-2) expression with KRAS and BRAF mutational status or survival outcomes in colorectal cancer (CRC) patients

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Background: MMP-1 and MMP-2 proteins are felt to be involved in tumor growth, invasion and metastasis and may be regulated by the KRAS pathway.

Methods: A tissue microarray was constructed from archival formalin-fixed paraffin-embedded primary tumor tissue samples of 96 patients with metastatic CRC. MMP-1 and MMP-2 expression was measured semiquantitatively by immunohistochemistry and graded 0 to 2. Mutation analysis was done for KRAS in codons 12 and 13, and patients without KRAS mutations were tested for BRAF V600E mutation. Chi-squared test, Fisher's exact test and Cox-proportionate hazard ratios were used for statistical analysis.

Results: 96 patients had samples available for analysis (median age at diagnosis 60, 57% male, 46% stage IV at diagnosis, 33/93 (35%) KRAS mutated, 7/51 (14%) BRAF mutated, 22% received anti-EGFR therapy). No significant association was identified between MMP-1 and KRAS (p=0.88) or BRAF (p=0.54), or between MMP-2 and KRAS (p=0.08) or BRAF (p=0.41). Neither overall survival nor survival from diagnosis of metastatic disease were affected by MMP-1 or MMP-2 expression.

Conclusions: MMP-1 and MMP-2 expression is not associated with KRAS or BRAF mutational status and is not a prognostic factor in our cohort of CRC patients.

No significant financial relationships to disclose.

Use of the XRCC1 single nucleotide polymorphism to predict pathologic complete response to neoadjuvant chemoradiation in stage II/III rectal cancer

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Background: The X-ray repair cross-complementing protein 1 (XRCC1) gene plays an important role in DNA damage repair; and the R194W and R399Q single nucleotide polymorphisms (SNPs) are associated with attenuated DNA repair activity. Our objective was to determine whether XRCC1 SNPs were associated with response to neoadjuvant chemoradiation therapy (CRT) in rectal cancer patients.

Methods: We conducted a prospective multicenter phase II trial to investigate the effect of additional chemotherapy with a longer CRT-to-surgery interval on treatment response in patients with rectal cancer. Paired normal and rectal cancer tissues were prospectively collected from enrolled patients (n=110). DNA was extracted from normal rectal mucosa and analyzed for XRCC1 R194W and R399Q by polymerase chain reaction and sequencing. Each SNP was compared to response to CRT. Response to CRT was determined by a central pathologist.

Results: Of the 110 patients, 25% (n=27) achieved a pathologic complete response (pCR). We examined the XRCC1 R194W SNP and observed that the allelic frequency of patients with the R/R genotype was 84% (n=92), the R/W genotype was 14% (n=16), the W/W genotype was 1% (n=2). By Fisher's Exact test, patients harboring either the R/W or W/W genotype, had a significantly higher rate of pCR compared to patients with the R/R genotype (44% vs. 21%, respectively; p=0.04). We then examined the R399Q SNP and observed that the allelic frequency of patients with the R/R genotype was 34% (n=37), the R/Q genotype was 49% (n=54), and the Q/Q genotype was 17% (n=19). In contrast, the detection of XRCC1 R399Q SNPs was not associated with pCR.

Conclusions: We demonstrate that XRCC1 R194W SNP is associated with increased rate of pCR in our prospective multi-center trial. Although the detection of XRCC1 R399Q SNP is not associated with pCR, the detection of XRCC1 SNPs that predict treatment response may help identify patients who are unlikely to respond to CRT and therefore may potentially avoid treatment-associated morbidities.

No significant financial relationships to disclose.

Laparoscopic distal gastrectomy for gastric cancer: Institutional experience with 38 consecutive patients and oncologic outcomes

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Background: The application of laparoscopy in the surgical treatment of gastric cancer has become more popular in recent years. Most of the published series are from Asia and few report on survival. Our objective was to elucidate the safety, efficacy, and oncologic outcomes of laparoscopic distal gastrectomy in patients with gastric cancer.

Methods: The medical records of all patients who underwent laparoscopic distal gastrectomy at City of Hope National Medical Center between 6/2005 and 8/2010 were retrospectively reviewed. Relevant data analyzed included patient demographics, operative parameters, complications, recurrence, and survival.

Results: A total of 38 consecutive patients were identified. Thirty-four of the 38 patients had a diagnosis of gastric adenocarcinoma. Median age was 70 years (35-96). Median operative time was 379 min (228-583). Median EBL was 200 ml (10-900). Seventeen of the 38 laparoscopic distal gastrectomy cases employed robotic assistance in lymph node dissection. The median number of lymph node retrieval was 23.5. Twenty-two cases included D2 lymph node dissections, 14 cases were D1 dissections, and 2 cases involved D0 dissections. All intended D2 dissections had greater than 15 nodes retrieved. Median hospital stay was 6 days (3-39). Morbidity and mortality rates were 11% and 0%, respectively. Of the 34 patients with gastric adenocarcinoma, histological staging revealed 1 patient had stage 0 disease, 25 had stage I, 7 had stage II, and 2 had stage III. Median follow-up was 12 months (0.5 to 58). Cancer recurrence occurred in 2 patients (6%). The 3 year overall survival is 69% and disease specific survival is 90%. The median survival has not been reached.

Conclusions: Laparoscopic distal gastrectomy is feasible and safe and can be performed in patients with gastric cancer with excellent surgical and oncologic outcomes.

No significant financial relationships to disclose.

Use of genetic variations to predict toxicity associated with neoadjuvant chemoradiation for AJCC stage II/III rectal cancer

411

Background: Genetic polymorphisms have been associated with toxicity from chemotherapeutic agents for colon cancer, but none has been identified for rectal cancer. We examined the association between polymorphisms in genes for DNA repair, cell cycle progression, angiogenesis, and drug metabolism with toxicity from neoadjuvant chemoradiation treatment (CRT) for rectal cancer.

Methods: Patients with AJCC stage II/III rectal adenocarcinoma were enrolled in a phase II multicenter trial examining timing of rectal cancer response to neoadjuvant CRT. There were two treatment arms: (I) radiation (XRT) and 5-FU followed by surgery and (II) XRT/5-FU and FOLFOX followed by surgery. Treatment toxicity, classified by the NCI Common Terminology Criteria guidelines as grade 3 and above, was recorded. DNA was extracted from normal rectal mucosa and analyzed for 22 polymorphisms in 17 genes.

Results: We evaluated 110 patients (group I, n = 52; group II, n = 58). A total of 19 patients experienced grade 3+ adverse events (AE) [group I, n = 10 (19%); group II, n = 9 (16%)]. Gastrointestinal symptoms were the most common AE [group I, n = 5 (10%); group II, n = 4 (7%)]. The detection of lys allele (lys/lys or lys/gln genotypes) at codon 751 of the Xeroderma pigmentosum group D (XPD) gene was associated with increased toxicity in group II (p = 0.03), whereas homozygosity for the arg allele (i.e., arg/arg genotype) at codon 399 of the X-ray cross-complementing protein 1 (XRCC1) gene was associated with a significant increase in toxicity in both treatment groups (p = 0.009).

Conclusions: Genetic polymorphisms in DNA damage repair genes XPD and XRCC1 are associated with toxicity in rectal cancer patients receiving CRT. The identification of gene polymorphisms that predict adverse events may help to optimize patient therapy while minimizing morbidities.

No significant financial relationships to disclose.

Monoclonal B cells detected in autologous PBSC grafts from patients with classical Hodgkin lymphoma: impact on relapse and survival following transplantation

Autologous peripheral blood stem cell transplantation (PBSCT) for Hodgkin lymphoma (HL) is curative for many patients with relapsed or refractory disease. Relapsing disease, however, remains a major problem. Neoplastic transformation of B-lymphocytes probably underlies the development of classical HL. Whether clonal B cells are critical for disease evolution and response to therapy in HL remains uncertain. We investigated the impact of clonal B cells detected in peripheral blood stem cell (PBSC) collections on the outcome of patients with HL undergoing transplant. Qualitative semi-nested PCR was carried out on genomic DNA from mononuclear cells from PBSCs to determine the presence of clonal immunoglobulin heavy chain (IgH) complementary-determining region 3 (CDR3) gene rearrangements. Clinical factors were assessed for their association with relapse, overall survival (OS) and progression-free survival (PFS). Among 39 patients undergoing PBSCT, 12 grafts (31%) were PCR positive for clonal IgH rearrangements. OS was better in the PCR-negative group (logrank test, P=0.041). The OS at 5 years was 81% in PCR-negative versus 39% in PCR-positive patients; hazard ratio was 3.23 (95% confidence interval: 0.98-10.63). There was a trend towards better PFS (logrank test, P=0.12), estimated as 71% at 5 years in PCR-negative versus 41% in PCR-positive patients. Clonal B-lymphocytes in PBSC collections of patients with HL identify patients at risk of poor outcome. Larger series are needed to confirm our observations. Insight regarding the role of monoclonal B cells may lead to improved therapies.

High-Density Transcranial Direct Current Stimulation (HD-tDCS): Skin Safety and Comfort

Transcranial Direct Current Stimulation (tDCS) is a non-invasive procedure where a weak electrical current (260 μA to 2 mA) is applied across the scalp to modulate brain function. tDCS has been applied for therapeutic purposes (e.g. addiction, depression, mood and sleep disorders) as well as cognitive performance enhancement (e.g. memory consolidation, motor learning and language recall). Despite safety and cost advantages, the developments of tDCS therapies have been restricted by spatial targeting concerns using existing two-channel systems. We have developed novel technology for High-Density tDCS (HD-tDCS) that improves spatial focality. Integral to the system are specialized HD-tDCS electrodes (<12 mm diameter) which allow safe and comfortable passage of current across the scalp. Here we evaluate a range of HD-tDCS electrode designs for comfort as well as test electrode over-potential, pH, and temperature. Passing 2 mA current for 22 minutes, both anodal and cathodal stimulations were evaluated independently. Subjective sensation during forearm stimulation was evaluated in 8 subjects. The benefits of skin electrical or chemical pre-conditioning were tested. Conductive Rubber, Ag, AgCl, pellet electrodes and AgCl ring electrodes were evaluated in combination with salty gels (Signa and CCNY4) and nominally electrolyte free gel (Lectron). The use of AgCl ring electrodes in combination with CCNY4 gel resulted in no significant pH, temperature, or over-potential changes under either polarity stimulation and was well tolerated by subjects. HD-tDCS may thus be applied with 2 mA per electrode for up to 22 minutes without skin irritation. Moreover, skin pre-conditioning can eliminate sensation such that HD-tDCS can be applied in a blinded fashion and under a broad range of therapeutic and performance enhancement applications. Our HD-tDCS system allows non-invasive, safe, and targeted modulation of selected cortical structures for electrotherapies that are individualized as well as optimized for a range of therapeutic applications.

Hypopigmented macular amyloidosis with or without hyperpigmentation

Primary cutaneous amyloidosis (PCA) is a chronic pruritic skin disorder with characteristic amyloid deposits in the papillary dermis. We report three cases of PCA, which shared common features of hypopigmentation as a predominant feature with or without reticular hyperpigmentation, no itching, adult onset and dermal papillary amyloid deposition. These cases did not conform to the usual features of PCA.

High-Density Transcranial Direct Current Stimulation (HD-tDCS): Skin Safety and Comfort

Transcranial Direct Current Stimulation (tDCS) is a non-invasive procedure where a weak electrical current (260 μA to 2 mA) is applied across the scalp to modulate brain function. tDCS has been applied for therapeutic purposes (e.g., addiction, depression, mood and sleep disorders) as well as cognitive performance enhancement (e.g., memory consolidation, motor learning and language recall). Despite safety and cost advantages, the developments of tDCS therapies have been restricted by spatial targeting concerns using existing two-channel systems. We have developed novel technology for High-Density tDCS (HD-tDCS) that improves spatial focality. Integral to the system are specialized HD-tDCS electrodes (<12 mm diameter) which allow safe and comfortable passage of current across the scalp. Here we evaluate a range of HD-tDCS electrode designs for comfort as well as test electrode over-potential, pH, and temperature. Passing 2 mA current for 22 minutes, both anodal and cathodal stimulations were evaluated independently. Subjective sensation during forearm stimulation was evaluated in 8 subjects. The benefits of skin electrical or chemical pre-conditioning were tested. Conductive Rubber, Ag, AgCl, pellet electrodes and AgCl ring electrodes were evaluated in combination with salty gels (Signa and CCNY4) and nominally electrolyte free gel (Lectron). The use of AgCl ring electrodes in combination with CCNY4 gel resulted in no significant pH, temperature, or over-potential changes under either polarity stimulation and was well tolerated by subjects. HD-tDCS may thus be applied with 2 mA per electrode for up to 22 minutes without skin irritation. Moreover, skin pre-conditioning can eliminate sensation such that HD-tDCS can be applied in a blinded fashion and under a broad range of therapeutic and performance enhancement applications. Our HD-tDCS system allows non-invasive, safe, and targeted modulation of selected cortical structures for electrotherapies that are individualized as well as optimized for a range of therapeutic applications.

Extramural vascular invasion is an adverse prognostic indicator of survival in patients with colorectal cancer

BACKGROUND/AIMS

Extramural vascular invasion (EVI) in colorectal cancer is reported to be a stage-independent adverse prognostic factor, and is a core item in the Royal College of Pathologists minimum data set for colorectal cancer histopathology reporting. The detection of EVI is also highly variable amongst pathologists. Our aims were to analyse both the frequency of EVI in colorectal cancer resections, and the effect of EVI on survival, in patients operated on over a 5-year period.

METHOD

A retrospective analysis of patients having potentially curative surgery for colorectal cancer between January 1999 and December 2004.

RESULTS

Over 5 years, 378 patients underwent a potentially curative resection. One-hundred seven (28.3%) cancers exhibited EVI, of which 104 (97%) were T3 and T4 tumours. Survival curves with and without EVI, unadjusted for nodal status and T stage, were significantly different (P = 0.0001) with 5-year survivals of 52% and 73% respectively. Survival curves for T3 and T4 tumours stratified with and without EVI also showed significantly different survival distributions (P = 0.007). A significant difference in frequency of EVI year on year was seen (P < 0.001), ranging from 8.5% to 46.7%, whereas the number of T3 and T4 tumours in each year was not significantly different (P = 0.677).

CONCLUSIONS

EVI is an adverse prognostic indicator for survival in patients undergoing potentially curative resection of colorectal cancer, and the routine requirement of EVI in colorectal cancer histopathology reporting is justified. Optimal specimen preparation, meticulous histopathological analysis and regular auditing of EVI detection rates are essential for the accurate staging of colorectal cancer.