Daniel Joyce - Academia.edu (original) (raw)

Papers by Daniel Joyce

Hepatology (Baltimore, Md.), Jan 22, 2015

Liver tolerance was initially recognized by the spontaneous acceptance of liver allograft in many... more Liver tolerance was initially recognized by the spontaneous acceptance of liver allograft in many species. The underlying mechanisms are not completely understood. We have been inspired by an unexpected phenomenon that the liver transplant tolerance absolutely requires interferon (IFN)-γ, a rejection-associated inflammatory cytokine. In this study, we investigate the rejection of liver allografts deficient in IFN-γ receptor and reveal that the liver graft is equipped with machineries capable of counterattacking the host immune response through a mesenchyme-mediated immune control (MMIC) mechanism. MMIC is triggered by T effectors (Tef) cell-derived IFN-γ to drive the expression of B7-H1 on graft mesenchymal cells leading to Tef cell apoptosis. We describe the negative feedback loop between graft mesenchymal and Tef cells that ultimately results in liver transplant tolerance. Comparable elevations of T regulatory cells and myeloid-derived suppressor cells are seen in both rejection a...

ACM SIGCSE Bulletin, 1996

World journal of gastroenterology : WJG, Jan 28, 2014

Pancreatic surgery is one of the most challenging and complex fields in general surgery. While mi... more Pancreatic surgery is one of the most challenging and complex fields in general surgery. While minimally invasive surgery has become the standard of care for many intra-abdominal pathologies the overwhelming majority of pancreatic surgery is performed in an open fashion. This is attributed to the retroperitoneal location of the pancreas, its intimate relationship to major vasculature and the complexity of reconstruction in the case of pancreatoduodenectomy. Herein, we describe the application of robotic technology to minimally invasive pancreatic surgery. The unique capabilities of the robotic platform have made the minimally invasive approach feasible and safe with equivalent if not better outcomes (e.g., decreased length of stay, less surgical site infections) to conventional open surgery. However, it is unclear whether the robotic approach is truly superior to traditional laparoscopy; this is a key point given the substantial costs associated with procuring and maintaining roboti...

JAMA Psychiatry, 2014

P sychosis has a prevalence of 1% in the population and is a devastating disease that strikes in ... more P sychosis has a prevalence of 1% in the population and is a devastating disease that strikes in early adulthood, with only 10% of those affected achieving complete remission. 1,2 Despite a significant investment in pharmacologic and psychosocial treatment during the last 40 years, 20% to 45% of patients experience significant positive symptoms despite optimal antipsychotic treatment. 3,4 The pathophysiologic mechanisms underlying these distressing symptoms remain unclear. Positive symptoms, such as auditory hallucinations and delusions of control, have been postulated to represent a misattribution of self-generated actions as externally generated as a consequence of a dysfunctional selfmonitoring mechanism. 5,6 Prediction is fundamental in the physiology of self-monitoring, permitting the sensory consequences of an action to be calculated and used to attenuate the perception related to this sensation. 7-10 The comparison of pre-dicted and actual sensation leads to the sense of agency, whereby concordance signifies that the movement is one's own, whereas discrepancy suggests the movement is externally generated.

Annual Joint Conference Integrating Technology into Computer Science Education, 2002

Hepatobiliary & Pancreatic Diseases International, 2014

Pancreatic lymphoepithelial cysts (LECs) are rare, benign lesions that are typically unexpected p... more Pancreatic lymphoepithelial cysts (LECs) are rare, benign lesions that are typically unexpected post-operative pathological findings. We aimed to review clinical, radiological and pathological features of LECs that may allow their preoperative diagnosis. Histopathology databases of two large pancreatic units were searched to identify LECs and notes reviewed to determine patient demographic details, mode of presentation, investigations, treatment and outcome. Five male and one female patients were identified. Their median age was 60 years. Lesions were identified on computed tomography performed for abdominal pain in two patients, and were incidentally observed in four patients. Five LECs were located in the tail and one in the body of the pancreas, with a median cyst size of 5 cm. Obtaining cyst fluid was difficult and a largely acellular aspirate was yielded. The pre-operative diagnosis was mucinous cystic neoplasm in all patients. This series of patients were treated distal pancreatectomy and splenectomy. A retrospective review of radiological examinations suggested that LECs have a relatively low signal on T2 imaging and a high signal intensity on T1 weighted images. LECs appear more common in elderly males, and are typically incidental, large, unilocular cysts. Close attention to signal intensity on MRI may allow preoperative diagnosis of these lesions.

ACM SIGCSE Bulletin

This panel is directed to members of the SIGCSE community who would like to learn more about the ... more This panel is directed to members of the SIGCSE community who would like to learn more about the places to publish in computing education and how to get published there. This panel brings together conference, journal, and bookseries editors to share their insights as "gatekeepers" of their respective publication venues.

PLoS ONE, 2014

Dysregulation of mesolimbic dopamine transmission is implicated in a number of psychiatric illnes... more Dysregulation of mesolimbic dopamine transmission is implicated in a number of psychiatric illnesses characterised by disruption of reward processing and goal-directed behaviour, including schizophrenia, drug addiction and impulse control disorders associated with chronic use of dopamine agonists. Amphetamine sensitization (AS) has been proposed to model the development of this aberrant dopamine signalling and the subsequent dysregulation of incentive motivational processes. However, in humans the effects of AS on the dopamine-sensitive neural circuitry associated with reward processing remains unclear. Here we describe the effects of acute amphetamine administration, following a sensitising dosage regime, on blood oxygen level dependent (BOLD) signal in dopaminoceptive brain regions during a rewarded gambling task performed by healthy volunteers. Using a randomised, double-blind, parallel-groups design, we found clear evidence for sensitization to the subjective effects of the drug, while rewarded reaction times were unchanged. Repeated amphetamine exposure was associated with reduced dorsal striatal BOLD signal during decision making, but enhanced ventromedial caudate activity during reward anticipation. The amygdala BOLD response to reward outcomes was blunted following repeated amphetamine exposure. Positive correlations between subjective sensitization and changes in anticipation-and outcome-related BOLD signal were seen for the caudate nucleus and amygdala, respectively. These data show for the first time in humans that AS changes the functional impact of acute stimulant exposure on the processing of reward-related information within dopaminoceptive regions. Our findings accord with pathophysiological models which implicate aberrant dopaminergic modulation of striatal and amygdala activity in psychosis and drug-related compulsive disorders.

Journal of Psychopharmacology, 2014

Amphetamine sensitisation (AS) is an established animal model of the hypersensitivity to psychost... more Amphetamine sensitisation (AS) is an established animal model of the hypersensitivity to psychostimulants seen in patients with schizophrenia. AS also models the dysregulation of mesolimbic dopamine signalling which has been implicated in the development of psychotic symptoms. Recent data suggest that the enhanced excitability of mesolimbic dopamine neurons in AS is driven by a hyperactivity of hippocampal (subiculum) neurons, consistent with a strong association between hippocampal dysfunction and schizophrenia. While AS can be modelled in human volunteers, its functional consequences on dopaminoceptive brain regions (i.e. striatum and hippocampus) remains unclear. Here we describe the effects of a sensitising dosage pattern of dextroamphetamine on the neural correlates of motor sequence learning in healthy volunteers, within a randomised, double-blind, parallel-groups design. Behaviourally, sensitisation was characterised by enhanced subjective responses to amphetamine but did not change performance (i.e. learning rate) during an explicit sequence learning task. In contrast, functional magnetic resonance imaging (fMRI) measurements showed that repeated intermittent amphetamine exposure was associated with increased blood-oxygen-level dependent (BOLD) signal within the medial temporal lobe (MTL) (subiculum/entorhinal cortex) and midbrain, in the vicinity of the substantia nigra/ventral tegmental area (SN/VTA) during sequence encoding. Importantly, MTL hyperactivity correlated with the sensitisation of amphetamine-induced attentiveness. The MTL-midbrain hyperactivity reported here mirrors observations in sensitised rodents and is consistent with contemporary models of schizophrenia and behavioural sensitisation. These findings of meso-hippocampal hyperactivity during AS thus link pathophysiological concepts of dopamine dysregulation to cognitive models of psychosis.

HPB, 2012

Background: Data have indicated that the lymph node ratio (LNR) may be a better prognostic indica... more Background: Data have indicated that the lymph node ratio (LNR) may be a better prognostic indicator than lymph node status in pancreatic cancer.

ACM SIGCUE Outlook, 1997

We focus on the practical issue of designing laboratory activities, concentrating on identifying ... more We focus on the practical issue of designing laboratory activities, concentrating on identifying key components necessary to insure quality and usefulness in the on-line SIGCSE Computing Laboratory Repository. We summarize the current capabilities and future extensions of the Repository, characterize a variety of qualities necessary and recommended for successful laboratory activities, identify a standard cover page for all lab activity submissions, and specify some guidelines for referees of submitted materials. Finally, we have designed four sample laboratory projects. Their contents are summarized in this paper and the completed projects will be available from the Repository after student testing in the Fall of 1997, if not sooner.