The effects of gabapentin in two animal models of co-morbid anxiety and visceral hypersensitivity

Visceral hypersensitivity and an increased response to stress are two of the main symptoms of irritable bowel syndrome. Thus efforts to develop animal models of irritable bowel syndrome have centred on both of these parameters. The anticonvulsant gabapentin, which is widely used as an analgesic agent, also reduces anxiety. No data exists to our knowledge of the effects of gabapentin in animal models of co-morbid exaggerated stress response and visceral pain. Our aim was to assess the effect of gabapentin on stress and visceral hypersensitivity in two different animal models of irritable bowel syndrome. The animal models employed were the genetically susceptible Wistar Kyoto rat and the neonatally stressed maternal separation model. These animals were subjected to the open field paradigm to assess stress-induced defecation rates and colorectal distension to assess the level of visceral sensitivity. Gabapentin (30 mg/kg) prevented the stress-induced increase in faecal pellet output in the maternally separated rat, but not the Wistar Kyoto animals. On the other hand gabapentin (30 mg/kg) reduced the number of pain behaviours in response to colorectal distension in both models. These results show that whilst both models have similar responses to gabapentin in terms of visceral pain they differ in terms of their physiological response to stress. This indicates that the origin of anxiety and perhaps then visceral hypersensitivity differs in these models. Overall, these data suggest that gabapentin may be a useful treatment in disorders of co-morbid pain and an overactive stress system such as irritable bowel syndrome.

Interhospital variation in the RATPAC trial (Randomised Assessment of Treatment using Panel Assay of Cardiac markers)

BACKGROUND

The RATPAC trial showed that using a point-of-care panel of CK-MB(mass), myoglobin and troponin at baseline and 90 min increased the proportion of patients successfully discharged home, leading to reduced median length of initial hospital stay. However, it did not change mean hospital stay and may have increased mean costs per patient. The aim of this study was to explore variation in outcome and costs between participating hospitals.

METHODS

RATPAC was a pragmatic multicentre randomised controlled trial (N=2243) and economic analysis comparing diagnostic assessment using the panel to standard care for patients with acute chest pain due to suspected myocardial infarction at six hospitals. The difference in the proportion of patients successfully discharged (primary outcome) and mean costs per patient between the participating hospitals was compared.

RESULTS

Point-of-care assessment led to a higher proportion of successful discharges in four hospitals, a lower proportion in one and was equivocal in another. The OR (95% CI) for the primary outcome varied from 0.12 (0.01 to 1.03) to 11.07 (6.23 to 19.66) with significant heterogeneity between the centres (p<0.001). The mean cost per patient for the intervention group ranged from being £214.49 less than the control group (-132.56 to 657.10) to £646.57 more expensive (73.12 to 1612.71), with weak evidence of heterogeneity between the centres (p=0.0803).

CONCLUSION

The effect of point-of-care panel assessment on successful discharge and costs per patient varied markedly between hospitals and may depend on local protocols, staff practices and available facilities.

Positron emission tomography (PET) and magnetic resonance imaging (MRI) for the assessment of axillary lymph node metastases in early breast cancer: systematic review and economic evaluation

BACKGROUND

Breast cancer is the most common type of cancer in women. Evaluation of axillary lymph node metastases is important for breast cancer staging and treatment planning.

OBJECTIVES

To evaluate the diagnostic accuracy, cost-effectiveness and effect on patient outcomes of positron emission tomography (PET), with or without computed tomography (CT), and magnetic resonance imaging (MRI) in the evaluation of axillary lymph node metastases in patients with newly diagnosed early-stage breast cancer.

DATA SOURCES

A systematic review of literature and an economic evaluation were carried out. Key databases (including MEDLINE, EMBASE and nine others) plus research registers and conference proceedings were searched for relevant studies up to April 2009. A decision-analytical model was developed to determine cost-effectiveness in the UK.

REVIEW METHODS

One reviewer assessed titles and abstracts of studies identified by the search strategy, obtained the full text of relevant papers and screened them against inclusion criteria. Data from included studies were extracted by one reviewer using a standardised data extraction form and checked by a second reviewer. Discrepancies were resolved by discussion. Quality of included studies was assessed using the quality assessment of diagnostic accuracy studies (QUADAS) checklist, applied by one reviewer and checked by a second.

RESULTS

Forty-five citations relating to 35 studies were included in the clinical effectiveness review: 26 studies of PET and nine studies of MRI. Two studies were included in the cost-effectiveness review: one of PET and one of MRI. Of the seven studies evaluating PET/CT (n = 862), the mean sensitivity was 56% [95% confidence interval (CI) 44% to 67%] and mean specificity 96% (95% CI 90% to 99%). Of the 19 studies evaluating PET only (n = 1729), the mean sensitivity was 66% (95% CI 50% to 79%) and mean specificity 93% (95% CI 89% to 96%). PET performed less well for small metastases; the mean sensitivity was 11% (95% CI 5% to 22%) for micrometastases (≤ 2 mm; five studies; n = 63), and 57% (95% CI 47% to 66%) for macrometastases (> 2 mm; four studies; n = 111). The smallest metastatic nodes detected by PET measured 3 mm, while PET failed to detect some nodes measuring > 15 mm. Studies in which all patients were clinically node negative showed a trend towards lower sensitivity of PET compared with studies with a mixed population. Across five studies evaluating ultrasmall super-paramagnetic iron oxide (USPIO)-enhanced MRI (n = 93), the mean sensitivity was 98% (95% CI 61% to 100%) and mean specificity 96% (95% CI 72% to 100%). Across three studies of gadolinium-enhanced MRI (n = 187), the mean sensitivity was 88% (95% CI 78% to 94%) and mean specificity 73% (95% CI 63% to 81%). In the single study of in vivo proton magnetic resonance spectroscopy (n = 27), the sensitivity was 65% (95% CI 38% to 86%) and specificity 100% (95% CI 69% to 100%). USPIO-enhanced MRI showed a trend towards higher sensitivity and specificity than gadolinium-enhanced MRI. Results of the decision modelling suggest that the MRI replacement strategy is the most cost-effective strategy and dominates the baseline 4-node sampling (4-NS) and sentinel lymph node biopsy (SLNB) strategies in most sensitivity analyses undertaken. The PET replacement strategy is not as robust as the MRI replacement strategy, as its cost-effectiveness is significantly affected by the utility decrement for lymphoedema and the probability of relapse for false-negative (FN) patients.

LIMITATIONS

No included studies directly compared PET and MRI.

CONCLUSIONS

Studies demonstrated that PET and MRI have lower sensitivity and specificity than SLNB and 4-NS but are associated with fewer adverse events. Included studies indicated a significantly higher mean sensitivity for MRI than for PET, with USPIO-enhanced MRI providing the highest sensitivity. However, sensitivity and specificity of PET and MRI varied widely between studies, and MRI studies were relatively small and varied in their methods; therefore, results should be interpreted with caution. Decision modelling based on these results suggests that the most cost-effective strategy may be MRI rather than SLNB or 4-NS. This strategy reduces costs and increases quality-adjusted life-years (QALYs) because there are fewer adverse events for the majority of patients. However, this strategy leads to more FN cases at higher risk of cancer recurrence and more false- positive (FP) cases who would undergo unnecessary axillary lymph node dissection. Adding MRI prior to SLNB or 4-NS has little effect on QALYs, though this analysis is limited by lack of available data. Future research should include large, well-conducted studies of MRI, particularly using USPIO; data on the long-term impacts of lymphoedema on cost and patient utility; studies of the comparative effectiveness and cost-effectiveness of SLNB and 4-NS; and more robust UK cost data for 4-NS and SLNB as well as the cost of MRI and PET techniques.

FUNDING

This study was funded by the Health Technology Assessment programme of the National Institute of Health Research.

Positron emission tomography (PET) and magnetic resonance imaging (MRI) for the assessment of axillary lymph node metastases in early breast cancer: systematic review and economic evaluation

BACKGROUND

Breast cancer is the most common type of cancer in women. Evaluation of axillary lymph node metastases is important for breast cancer staging and treatment planning.

OBJECTIVES

To evaluate the diagnostic accuracy, cost-effectiveness and effect on patient outcomes of positron emission tomography (PET), with or without computed tomography (CT), and magnetic resonance imaging (MRI) in the evaluation of axillary lymph node metastases in patients with newly diagnosed early-stage breast cancer.

DATA SOURCES

A systematic review of literature and an economic evaluation were carried out. Key databases (including MEDLINE, EMBASE and nine others) plus research registers and conference proceedings were searched for relevant studies up to April 2009. A decision-analytical model was developed to determine cost-effectiveness in the UK.

REVIEW METHODS

One reviewer assessed titles and abstracts of studies identified by the search strategy, obtained the full text of relevant papers and screened them against inclusion criteria. Data from included studies were extracted by one reviewer using a standardised data extraction form and checked by a second reviewer. Discrepancies were resolved by discussion. Quality of included studies was assessed using the quality assessment of diagnostic accuracy studies (QUADAS) checklist, applied by one reviewer and checked by a second.

RESULTS

Forty-five citations relating to 35 studies were included in the clinical effectiveness review: 26 studies of PET and nine studies of MRI. Two studies were included in the cost-effectiveness review: one of PET and one of MRI. Of the seven studies evaluating PET/CT (n = 862), the mean sensitivity was 56% [95% confidence interval (CI) 44% to 67%] and mean specificity 96% (95% CI 90% to 99%). Of the 19 studies evaluating PET only (n = 1729), the mean sensitivity was 66% (95% CI 50% to 79%) and mean specificity 93% (95% CI 89% to 96%). PET performed less well for small metastases; the mean sensitivity was 11% (95% CI 5% to 22%) for micrometastases (≤ 2 mm; five studies; n = 63), and 57% (95% CI 47% to 66%) for macrometastases (> 2 mm; four studies; n = 111). The smallest metastatic nodes detected by PET measured 3 mm, while PET failed to detect some nodes measuring > 15 mm. Studies in which all patients were clinically node negative showed a trend towards lower sensitivity of PET compared with studies with a mixed population. Across five studies evaluating ultrasmall super-paramagnetic iron oxide (USPIO)-enhanced MRI (n = 93), the mean sensitivity was 98% (95% CI 61% to 100%) and mean specificity 96% (95% CI 72% to 100%). Across three studies of gadolinium-enhanced MRI (n = 187), the mean sensitivity was 88% (95% CI 78% to 94%) and mean specificity 73% (95% CI 63% to 81%). In the single study of in vivo proton magnetic resonance spectroscopy (n = 27), the sensitivity was 65% (95% CI 38% to 86%) and specificity 100% (95% CI 69% to 100%). USPIO-enhanced MRI showed a trend towards higher sensitivity and specificity than gadolinium-enhanced MRI. Results of the decision modelling suggest that the MRI replacement strategy is the most cost-effective strategy and dominates the baseline 4-node sampling (4-NS) and sentinel lymph node biopsy (SLNB) strategies in most sensitivity analyses undertaken. The PET replacement strategy is not as robust as the MRI replacement strategy, as its cost-effectiveness is significantly affected by the utility decrement for lymphoedema and the probability of relapse for false-negative (FN) patients.

LIMITATIONS

No included studies directly compared PET and MRI.

CONCLUSIONS

Studies demonstrated that PET and MRI have lower sensitivity and specificity than SLNB and 4-NS but are associated with fewer adverse events. Included studies indicated a significantly higher mean sensitivity for MRI than for PET, with USPIO-enhanced MRI providing the highest sensitivity. However, sensitivity and specificity of PET and MRI varied widely between studies, and MRI studies were relatively small and varied in their methods; therefore, results should be interpreted with caution. Decision modelling based on these results suggests that the most cost-effective strategy may be MRI rather than SLNB or 4-NS. This strategy reduces costs and increases quality-adjusted life-years (QALYs) because there are fewer adverse events for the majority of patients. However, this strategy leads to more FN cases at higher risk of cancer recurrence and more false- positive (FP) cases who would undergo unnecessary axillary lymph node dissection. Adding MRI prior to SLNB or 4-NS has little effect on QALYs, though this analysis is limited by lack of available data. Future research should include large, well-conducted studies of MRI, particularly using USPIO; data on the long-term impacts of lymphoedema on cost and patient utility; studies of the comparative effectiveness and cost-effectiveness of SLNB and 4-NS; and more robust UK cost data for 4-NS and SLNB as well as the cost of MRI and PET techniques.

FUNDING

This study was funded by the Health Technology Assessment programme of the National Institute of Health Research.

Clinical decision rules for children with minor head injury: a systematic review

INTRODUCTION

Clinical decision rules aid clinicians with the management of head injured patients. This study aimed to identify clinical decision rules for children with minor head injury and compare their diagnostic accuracy for detection of intracranial injury (ICI) and injury requiring neurosurgical intervention (NSI).

METHODS

Relevant studies were identified by an electronic search of key databases. Papers in English were included with a cohort of at least 20 children suffering minor head injury (GCS 13-15). Studies of a decision rule derived to identify patients at risk of ICI or NSI had to include a proportion of the cohort undergoing imaging. Study quality was assessed using the QUADAS checklist.

RESULTS

16 publications, representing 14 cohorts, with 79 740 patients were included. Only four rules were tested in more than one cohort. Of the validated rules the paediatric emergency care applied research network (PECARN) rule was most consistent (sensitivity 98%; specificity 58%). For neurosurgical injury all had high sensitivity (98-100%) but the children's head injury algorithm for the prediction of important clinical events (CHALICE) rule had the highest specificity (86%) in its derivation cohort.

CONCLUSION

Of the current decision rules for minor head injury the PECARN rule appears the best for children and infants, with the largest cohort, highest sensitivity and acceptable specificity for clinically significant ICI. Application of this rule in the UK would probably result in an unacceptably high rate of CT scans per injury, and continued use of the CHALICE-based NICE guidelines represents an appropriate alternative.

Cost-effectiveness of point-of-care biomarker assessment for suspected myocardial infarction: the randomized assessment of treatment using panel Assay of cardiac markers (RATPAC) trial

OBJECTIVES

Chest pain due to suspected myocardial infarction (MI) is responsible for many hospital admissions and consumes substantial health care resources. The Randomized Assessment of Treatment using Panel Assay of Cardiac markers (RATPAC) trial showed that diagnostic assessment using a point-of-care (POC) cardiac biomarker panel consisting of CK-MB, myoglobin, and troponin increased the proportion of patients successfully discharged after emergency department (ED) assessment. In this economic analysis, the authors aimed to determine whether POC biomarker panel assessment reduced health care costs and was likely to be cost-effective.

METHODS

The RATPAC trial was a multicenter individual patient randomized controlled trial comparing diagnostic assessment using a POC biomarker panel (CK-MB, myoglobin, and troponin, measured at baseline and 90 minutes) to standard care without the POC panel in patients attending six EDs with acute chest pain due to suspected MI (n = 2,243). Individual patient resource use data were collected from all participants up to 3 months after hospital attendance using self-completed questionnaires at 1 and 3 months and case note review. ED staff and POC testing costs were estimated through a microcosting study of 246 participants. Resource use was valued using national unit costs. Health utility was measured using the EQ-5D self-completed questionnaire, mailed at 1 and 3 months. Quality-adjusted life-years (QALYs) were calculated by the trapezium rule using the EQ-5D tariff values at all follow-up points. Mean costs per patient were compared between the two treatment groups. Cost-effectiveness was estimated in terms of probability of dominance and incremental cost per QALY.

RESULTS

Point-of-care panel assessment was associated with higher ED costs, coronary care costs, and cardiac intervention costs, but lower general inpatient costs. Mean costs per patient were £1217.14 (standard deviation [SD] ± 3164.93), or $1,987.14 (SD ±$4,939.25), with POC versus £1005.91 (SD ±£1907.55), or $1,568.64 (SD ±$2,975.78), with standard care (p = 0.056). Mean QALYs were 0.158 (SD ± 0.052) versus 0.161 (SD ± 0.056; p = 0.250). The probability of standard care being dominant (i.e., cheaper and more effective) was 0.888, while the probability of the POC panel being dominant was 0.004. These probabilities were not markedly altered by sensitivity analysis varying the costs of the POC panel and excluding intensive care costs.

CONCLUSIONS

Point-of-care panel assessment does not reduce costs despite reducing admissions and may even increase costs. It is unlikely to be considered a cost-effective use of health care resources.

Catalytic activity of the caspase-8-FLIP(L) complex inhibits RIPK3-dependent necrosis

Caspase-8 has two opposing biological functions--it promotes cell death by triggering the extrinsic pathway of apoptosis, but also has a survival activity, as it is required for embryonic development, T-lymphocyte activation, and resistance to necrosis induced by tumour necrosis factor-α (TNF-α) and related family ligands. Here we show that development of caspase-8-deficient mice is completely rescued by ablation of receptor interacting protein kinase-3 (RIPK3). Adult animals lacking both caspase-8 and RIPK3 display a progressive lymphoaccumulative disease resembling that seen with defects in CD95 or CD95-ligand (also known as FAS and FASLG, respectively), and resist the lethal effects of CD95 ligation in vivo. We have found that caspase-8 prevents RIPK3-dependent necrosis without inducing apoptosis by functioning in a proteolytically active complex with FLICE-like inhibitory protein long (FLIP(L), also known as CFLAR), and this complex is required for the protective function.

The probiotic Bifidobacterium infantis 35624 displays visceral antinociceptive effects in the rat

BACKGROUND

Irritable bowel syndrome (IBS) is characterized by recurrent abdominal pain and altering bowel habit with a high percentage of patients displaying comorbid anxiety. Growing clinical and preclinical evidence suggests that probiotic agents may restore the altered brain-gut communication in IBS. In this study, we evaluated the efficacy of repeated treatment with three different probiotics in reducing visceral pain in visceral normosensitive (Sprague-Dawley [SD]) and visceral hypersensitive (Wistar-Kyoto [WKY]) rat strains.

METHODS

Following 14 days oral gavage of Lactobacillus salivarius UCC118, Bifidobacterium infantis 35624, or Bifidobacterium breve UCC2003 both SD and WKY rats were exposed to a novel stress, the open field arena and their behavior was recorded. Subsequently, the effects of probiotics on visceral nociceptive responses were analyzed by recording pain behaviors during colorectal distension (CRD).

KEY RESULTS

It was found that there was a difference in the open field behavior between strains but none of the probiotic treatment altered behavior within each strain. Interestingly, the probiotic B. infantis 35624 but not others tested significantly reduced CRD-induced visceral pain behaviors in both rat strains. It significantly increased the threshold pressure of the first pain behavior and also reduced the total number pain behaviors during CRD.

CONCLUSIONS & INFERENCES

These data confirm that probiotics such as B. infantis 35624 are effective in reducing visceral pain and may be effective in treating certain symptoms of IBS.

Locoregional therapies for hepatocellular carcinoma: which patients are most likely to gain a survival advantage?

BACKGROUND AND AIM

Locoregional therapies for hepatocellular carcinoma (HCC) are considered to confer a survival advantage, however, the patient group that should be targeted is not clearly defined. This study aimed to determine the impact on survival of locoregional therapies compared with supportive care, within prognostic categories as stratified by the Cancer of the Liver Italian Program (CLIP) scoring system.

METHODS

A prospective database was used to identify those patients who were treated with either locoregional therapy (n = 128) or supportive care (n = 92). Survival analysis was performed for groups matched by CLIP score at presentation. Comparison of important prognostic factors was undertaken and univariate and multivariate analysis was performed to assess determinants of survival.

RESULTS

Use of locoregional therapies was only associated with a survival benefit in patients with a CLIP score of 1 or 2. In this group, the median survival in patients who received locoregional therapies was 25.0 months (95% confidence interval 22.7-27.4) compared with 8.9 months (95% confidence interval 7.3-10.5) for supportive care (P = 0.001). For patients with CLIP scores of 3 or greater, no survival benefit of locoregional therapies was observed. Multivariate analysis revealed locoregional intervention, CLIP score, tumor symptoms, alpha-fetoprotein level, bilirubin and alkaline phosphatase level as independent prognostic indicators.

CONCLUSION

Locoregional therapies should be targeted specifically to patients with non-advanced hepatocellular carcinoma as assessed by validated scoring systems. Use of these therapies in patients with advanced disease does not appear to be associated with a survival benefit and may expose patients to unnecessary harm.

5-HT(2B) receptors modulate visceral hypersensitivity in a stress-sensitive animal model of brain-gut axis dysfunction

BACKGROUND

Irritable bowel syndrome (IBS) is associated with an enhanced perception to visceral stimuli and exaggerated stress response. The serotonergic neurotransmitter system has been strongly implicated as a key player in the manifestation of IBS symptomatology including visceral hypersensitivity. However the role of 5-HT(2B) receptors in visceral pain, although speculated, is currently unclear. Thus we assessed the impact of a selective 5-HT(2B) receptor antagonist, RS-127445, on visceral hypersensitivity in a model of brain gut axis dysfunction the Wistar Kyoto (WKY) rat.

METHODS

Colorectal distension (CRD) was used to assess the visceral sensitivity of the WKY rat compared to normosensitive Sprague Dawley (SD) rats. Once we verified the visceral sensitivity of the WKY rat we assessed the efficacy of RS-127445 in pain signalling from the colorectum. We administered the compound peripherally (i.p.) and centrally (i.c.v.) in order to ascertain the site of action of RS 127445. Behavioural responses to colorectal distention were then monitored.

KEY RESULTS

The WKY rats were more viscerally hypersensitive than the SD as previously shown. RS-127445 (5 mg kg(-1), i.p.) significantly reversed visceral hypersensitivity in WKY animals. Moreover, when administered intracerebroventricularly RS-127445 (100 nM) also decreased the number of pain behaviours during noxious CRD in the WKY animals.

CONCLUSIONS & INFERENCES

Taken together, blockade of 5-HT(2B) receptors offers an exciting novel therapeutic target for pain relief in stress-related gastrointestinal disorders such as IBS.

Cell death and tissue remodeling in planarian regeneration

Many long-lived organisms, including humans, can regenerate some adult tissues lost to physical injury or disease. Much of the previous research on mechanisms of regeneration has focused on adult stem cells, which give rise to new tissue necessary for the replacement of missing body parts. Here we report that apoptosis of differentiated cells complements stem cell division during regeneration in the planarian Schmidtea mediterranea. Specifically, we developed a whole-mount TUNEL assay that allowed us to document two dramatic increases in the rate of apoptosis following amputation-an initial localized response near the wound site and a subsequent systemic response that varies in magnitude depending on the type of fragment examined. The latter cell death response can be induced in uninjured organs, occurs in the absence of planarian stem cells, and can also be triggered by prolonged starvation. Taken together, our results implicate apoptosis in the restoration of proper anatomical scale and proportion through remodeling of existing tissues. We also report results from initial mechanistic studies of apoptosis in planarians, which revealed that a S. mediterranea homolog of the antiapoptotic gene BCL2 is required for cell survival in adult animals. We propose that apoptosis is a central mechanism working in concert with stem cell division to restore anatomical form and function during metazoan regeneration.

So-called "malignant blue nevus": a clinicopathologic study of 23 patients

BACKGROUND

Melanomas that arise in association with or that resemble blue nevi are extremely rare and have been termed "malignant blue nevi." The authors report on a single-institutional clinicopathologic study of "blue nevus-like melanomas" (BNLMs).

METHODS

Twenty-six patients were identified with a "malignant blue nevus" over 29 years at the Sydney Melanoma Unit. Twenty-three patients were included in the current study after pathologic review. Clinical outcomes of those patients were compared with the outcomes in a matched control group of patients with melanoma (matched for age, sex, Breslow thickness, Clark level, ulceration, and anatomic site).

RESULTS

The median patient age was 44 years, and men comprised 65% of the patients. The tumors were distributed evenly among skin sites, and their median Breslow thickness was 5.5 mm. After a median follow-up of 36.5 months, there was no difference in survival (P = .702) between patients with BNLM and patients in the control group.

CONCLUSIONS

BNLMs tended to present at a more advanced stage, with thicker primary tumors, but had a metastatic pattern comparable to and was not more aggressive in behavior than other types of melanoma. The authors concluded that BNLMs should be treated in the same way as any other melanoma variants based on clinical staging and pathologic prognostic indices.

Desmoplastic neurotropic melanoma: a clinicopathologic analysis of 128 cases

BACKGROUND

Several studies have suggested that desmoplastic neurotropic melanoma (DNM) is associated with higher local recurrence rates than other types of melanoma. The authors investigated the local recurrence rates for patients with DNM after surgery alone or surgery followed by radiotherapy (RT).

METHODS

One hundred twenty-eight patients with DNM were treated at the Sydney Melanoma Unit and the Sydney Cancer Center from 1996 to 2007. All patients underwent local excision, 27 patients also received RT. For both groups, clinical and pathologic features, treatment details, and local recurrence data were analyzed.

RESULTS

The median age at diagnosis was 65.5 years. The ratio of men to women was 2.7:1. The head and neck was the most common location (51%). The median Breslow thickness was 4 mm, and 99% of patients had Clark Level IV or V primary tumors. Patients who received adjuvant RT had thicker tumors (P = .003), deeper Clark level invasion (P < .001), and narrower excision margins (P < .001). There were 8 local recurrences, including 6 (6%) in the surgery only group and 2 (7%) in the adjuvant RT group. A positive margin (P < .001) and head and neck location (P = .03) were significant predictors of local recurrence.

CONCLUSIONS

The local recurrence rate in this series was lower than the rates reported in historic control groups and in the authors' previous temporal cohort. The results indicated that clear surgical margins are of paramount importance in minimizing local recurrence; when margins are compromised, the addition of RT may reduce local recurrence rates compared with historic controls. A prospective randomized trial is needed to quantify the risk reduction with adjuvant RT.

Tryptophan catabolism in females with irritable bowel syndrome: relationship to interferon-gamma, severity of symptoms and psychiatric co-morbidity

Irritable bowel syndrome (IBS) has been linked with abnormal serotonin functioning and immune activation. Tryptophan forms the substrate for serotonin biosynthesis, but it can alternatively be catabolized to kynurenine (Kyn) by the enzyme indoleamine 2,3-dioxygenase (IDO), the main inducer of which is interferon-gamma. The primary aim of this study was to test the hypothesis that IBS is associated with increased tryptophan (Trp) catabolism along the Kyn pathway due to increased IFN-gamma levels. Plasma Kyn, Trp and IFN-gamma levels were measured in 41 female IBS subjects and 33 controls. Indoleamine 2,3-dioxygenase activity was assessed using the Kyn to Trp ratio. Psychiatric co-morbidity was assessed using the Patient Health Questionnaire, and severity of IBS assessed using self-report ordinal scales. Irritable bowel syndrome subjects had increased Kyn concentrations compared with controls (P = 0.039) and there was a trend for Kyn:Trp to be increased in the IBS group (P = 0.09). There was a positive correlation between IBS severity and Kyn:Trp (r = 0.57, P < 0.001). Those with severe IBS symptoms had increased Kyn:Trp (P < 0.005) compared to those with less severe symptoms and controls, and were over twice as likely to have depression or anxiety compared to those with less severe IBS (RR = 2.2, 95% CI 1.2-3.9). No difference in IFN-gamma levels was observed between groups; however, IFN-gamma was positively correlated with Kyn:Trp in IBS (r = 0.58, P = 0.005) but not controls (r = 0.12, P = 0.5). Females with IBS have abnormal Trp catabolism. The Kyn:Trp is related to symptom severity, and those with severe IBS symptoms have increased shunting of Trp along the Kyn pathway which contributes to the abnormal serotonergic functioning in this syndrome.

Neurology referrals to a liaison psychiatry service

The objective of the present study was to assess the activity of the Liaison Psychiatry service of Cork University Hospital in relation to all in-patient neurology referrals over a 12-month period. Of 1685 neurology admissions, 106 (6%) were referred to liaison psychiatry for assessment. 91 referrals (86%) met criteria for a psychiatric disorder according to DSM-IV, the commonest being major depression (24%) and somatoform disorder (23%). Patients with multiple sclerosis or epilepsy comprised nearly half of all referrals (48 cases; 45%). Approximately 20% of M.S. in-patients (21 cases) were referred for psychiatric assessment, with the corresponding figure in epilepsy being 25% (18 cases). Although only 106 (6%) neurology in-patients were referred to liaison psychiatry, psychiatric diagnoses were documented in 327 (20%) discharge forms, presumably reflecting previous diagnosis. The above findings indicate that psychiatric illness is common among neurology inpatients screened by liaison psychiatry yet referral rates are relatively low in terms of the overall number of neurology in-patients. Psychiatric disorders were diagnosed in 86% of referrals indicating high concordance between neurologists and liaison psychiatry regarding the presence of a psychiatric disorder.

History of illness prior to a diagnosis of bipolar disorder or schizoaffective disorder

BACKGROUND

There are obstacles to early identification of bipolar disorder. Identifying and treating illness early in its time course may be associated with a better prognosis.

METHODS

A questionnaire was administered at interview, when the participant was euthymic, to participants (n=240) enrolled in the Bipolar Comprehensive Outcomes Study (BCOS). Information was collected about the sequential timeline of specific symptoms of mental illness up to when they first received a diagnosis of Bipolar Disorder or Schizoaffective Disorder.

RESULTS

Any symptoms of mental illness were first experienced at 17.5 years (median; Inter Quartile Range (IQR) 13.8-24.3; n=216) and mood swings at 18.0 years (IQR 14-25; n=197). Symptoms of depression were experienced at 18.0 years (IQR 14-25; n=197), a full episode of depression at 21.2 years (IQR 17-28.5; n=200), symptoms of mania at 21.0 years (IQR 16.8-29.5; n=212) and a full episode of mania at 24.1 years (IQR 19-30.5; n=205). Medical treatment was sought at 24.0 years (IQR 19-31.5; n=217). Participants received a diagnosis of Bipolar Disorder or Schizoaffective Disorder at 30.0 years (IQR 23-37.3; n=215). Having had a previous diagnosis other than Bipolar Disorder or Schizoaffective Disorder was reported by 120 of 216 participants who answered this question, most commonly unipolar depression (26.6%). Diagnostic delay was greater in individuals with early onset disorder.

CONCLUSIONS

Participants typically experience a long sequential course of symptoms, episodes, treatments and diagnosis. The polarity of onset is most commonly depressive, and subthreshold symptoms tend to precede threshold symptoms of both polarities.

LIMITATIONS

Data were collected retrospectively.

49. Effect of a resident-as-teacher training programme on surgical resident clinical teaching skills

This study was designed to assess the benefits of a resident-as-teacher training programme on surgical residents within a surgical clinical teaching unit. A randomized controlled trial was conducted at McMaster University between July 2005 and June 2006. Twenty-eight (28) General Surgery Residents and one 134 Medical Students participated in the study. Residents were randomly assigned to participate in a two-day training course on clinical teaching skills at the 3 or 12-month interval. Medical Students completed teaching evaluations on residents whom they had significant exposure. Resident scores on teaching evaluations as well as medical student performance on rotation examinations were assessed. The intervention (n=14) and control (n=14) groups were at similar levels of training. Only 5 intervention and 9 control residents had both pre and post intervention evaluations. Evaluations were measured on a 1 to 5 Likert scale. Data was analyzed by intention-to-treat. The mean evaluation score in both control and intervention groups were higher than pre-intervention (8% and 14%, p=0.03). However, the magnitude of change between the 2 groups was not statistically significant. Medical student performance by those exposed to more intervention residents was not significantly different from those exposed to more control residents. There is a significant improvement in resident teaching over an academic year, as determined by medical student evaluations of the resident-teachers. Although there was a trend of improved teaching with the teaching- skills intervention, the difference was not statistically significant, and did not affect medical student performance on the end-of rotation examinations. Blue AV, et al. Surgical Teaching Quality Makes a Difference. American Journal of Surgery 1999; 177:86-9. Dunnington GL, DaRosa D. A prospective Randomized Trial of Residents-as-teachers Training Program. Academic Medicine 1998; 73: 696-700. Griffith CH, et al. Relationship of How Well Attending Physicians Teach to Their Students’ Performances and Residency Choices. Academic Medicine 1997; 72:S118-120.

GAPDH and autophagy preserve survival after apoptotic cytochrome c release in the absence of caspase activation

In cells undergoing apoptosis, mitochondrial outer-membrane permeabilization (MOMP) is followed by caspase activation promoted by released cytochrome c. Although caspases mediate the apoptotic phenotype, caspase inhibition is generally not sufficient for survival following MOMP; instead cells undergo a "caspase-independent cell death" (CICD). Thus, MOMP may represent a point of commitment to cell death. Here, we identify glyceraldehyde-3-phosphate dehydrogenase (GAPDH) as a critical regulator of CICD. GAPDH-expressing cells preserved their clonogenic potential following MOMP, provided that caspase activation was blocked. GAPDH-mediated protection of cells from CICD involved an elevation in glycolysis and a nuclear function that correlated with and was replaced by an increase in Atg12 expression. Consistent with this, protection from CICD reflected an increase in and a dependence upon autophagy, associated with a transient decrease in mitochondrial mass. Therefore, GAPDH mediates an elevation in glycolysis and enhanced autophagy that cooperate to protect cells from CICD.