Tomography reconstruction of beams extracted from an ion source.

Commissioning of the CANREB (CANadian Rare isotope facility with Electron Beam ion source) system and its associated beamlines has recently begun at TRIUMF. At the head of this beamline is an ion source used to produce stable alkaline ions with energy up to 60 keV for the CANREB system. Throughout commissioning, it is essential to have a means of verifying beam quality and ensuring that the required beam parameters along the beamline are met. This is accomplished using tomography reconstruction, which consists of taking one-dimensional scans at different projections and reconstructing an image of the beam in two dimensions using the maximum entropy algorithm. Tomography enables the visualization of the shape of the beam as well as the investigation into the possible presence of aberrations. Initially, tomography reconstruction is performed by using simulated beam profiles at the measurement locations and is then performed by using measured beam profiles. Additionally, these measurements are benchmarked by fitting the initial beam parameters in our beam optics model, and the results are presented.

Neurons derived from patients with bipolar disorder divide into intrinsically different sub-populations of neurons, predicting the patients' responsiveness to lithium.

Bipolar disorder (BD) is a progressive psychiatric disorder with more than 3% prevalence worldwide. Affected individuals experience recurrent episodes of depression and mania, disrupting normal life and increasing the risk of suicide greatly. The complexity and genetic heterogeneity of psychiatric disorders have challenged the development of animal and cellular models. We recently reported that hippocampal dentate gyrus (DG) neurons differentiated from induced pluripotent stem cell (iPSC)-derived fibroblasts of BD patients are electrophysiologically hyperexcitable. Here we used iPSCs derived from Epstein-Barr virus-immortalized B-lymphocytes to verify that the hyperexcitability of DG-like neurons is reproduced in this different cohort of patients and cells. Lymphocytes are readily available for research with a large number of banked lines with associated patient clinical description. We used whole-cell patch-clamp recordings of over 460 neurons to characterize neurons derived from control individuals and BD patients. Extensive functional analysis showed that intrinsic cell parameters are very different between the two groups of BD neurons, those derived from lithium (Li)-responsive (LR) patients and those derived from Li-non-responsive (NR) patients, which led us to partition our BD neurons into two sub-populations of cells and suggested two different subdisorders. Training a Naïve Bayes classifier with the electrophysiological features of patients whose responses to Li are known allows for accurate classification with more than 92% success rate for a new patient whose response to Li is unknown. Despite their very different functional profiles, both populations of neurons share a large, fast after-hyperpolarization (AHP). We therefore suggest that the large, fast AHP is a key feature of BD and a main contributor to the fast, sustained spiking abilities of BD neurons. Confirming our previous report with fibroblast-derived DG neurons, chronic Li treatment reduced the hyperexcitability in the lymphoblast-derived LR group but not in the NR group, strengthening the validity and utility of this new human cellular model of BD.

Charge state breeding experiences and plans at TRIUMF.

At the Isotope Separation and ACceleration (ISAC) facility at TRIUMF, an electron cyclotron resonance ion source (ECRIS) has been set up for the charge state breeding of radioactive ions. In order to reduce background from stable ions generated in the ECRIS, several measures, including changing materials for the plasma chamber and the surrounding components, have been implemented. Further reduction has been achieved by using the post-accelerator chain as a mass filter. Since the implementation of those measures in 2013, physics experiments with accelerated radioactive isotopes of Rb, Sr, K, and Mg have been performed. In most cases, a charge breeding efficiency of several percent has been achieved. With the planned expansion of the isotope production capabilities at TRIUMF within the Advanced Rare IsotopE Laboratory project, two new target stations, one using photo-fission induced by a high-power electron beam at 50 MeV and the other one using 480 MeV protons as at ISAC, will be put into operation within the next 5 yr. Additionally, a new electron beam ion source (EBIS) based charge state breeding system will be installed. Background from such a source is expected to be much lower. The drawback is that for the efficient operation of such a system, pulsed beam operation is required, which makes the installation of an additional ion buncher in front of the EBIS necessary.

Generation of functional human serotonergic neurons from fibroblasts.

The brain's serotonergic system centrally regulates several physiological processes and its dysfunction has been implicated in the pathophysiology of several neuropsychiatric disorders. While in the past our understanding of serotonergic neurotransmission has come mainly from mouse models, the development of pluripotent stem cell and induced fibroblast-to-neuron (iN) transdifferentiation technologies has revolutionized our ability to generate human neurons in vitro. Utilizing these techniques and a novel lentiviral reporter for serotonergic neurons, we identified and overexpressed key transcription factors to successfully generate human serotonergic neurons. We found that overexpressing the transcription factors NKX2.2, FEV, GATA2 and LMX1B in combination with ASCL1 and NGN2 directly and efficiently generated serotonergic neurons from human fibroblasts. Induced serotonergic neurons (iSNs) showed increased expression of specific serotonergic genes that are known to be expressed in raphe nuclei. iSNs displayed spontaneous action potentials, released serotonin in vitro and functionally responded to selective serotonin reuptake inhibitors (SSRIs). Here, we demonstrate the efficient generation of functional human serotonergic neurons from human fibroblasts as a novel tool for studying human serotonergic neurotransmission in health and disease.

Creating Patient-Specific Neural Cells for the In Vitro Study of Brain Disorders.

As a group, we met to discuss the current challenges for creating meaningful patient-specific in vitro models to study brain disorders. Although the convergence of findings between laboratories and patient cohorts provided us confidence and optimism that hiPSC-based platforms will inform future drug discovery efforts, a number of critical technical challenges remain. This opinion piece outlines our collective views on the current state of hiPSC-based disease modeling and discusses what we see to be the critical objectives that must be addressed collectively as a field.

Modeling non-syndromic autism and the impact of TRPC6 disruption in human neurons.

An increasing number of genetic variants have been implicated in autism spectrum disorders (ASDs), and the functional study of such variants will be critical for the elucidation of autism pathophysiology. Here, we report a de novo balanced translocation disruption of TRPC6, a cation channel, in a non-syndromic autistic individual. Using multiple models, such as dental pulp cells, induced pluripotent stem cell (iPSC)-derived neuronal cells and mouse models, we demonstrate that TRPC6 reduction or haploinsufficiency leads to altered neuronal development, morphology and function. The observed neuronal phenotypes could then be rescued by TRPC6 complementation and by treatment with insulin-like growth factor-1 or hyperforin, a TRPC6-specific agonist, suggesting that ASD individuals with alterations in this pathway may benefit from these drugs. We also demonstrate that methyl CpG binding protein-2 (MeCP2) levels affect TRPC6 expression. Mutations in MeCP2 cause Rett syndrome, revealing common pathways among ASDs. Genetic sequencing of TRPC6 in 1041 ASD individuals and 2872 controls revealed significantly more nonsynonymous mutations in the ASD population, and identified loss-of-function mutations with incomplete penetrance in two patients. Taken together, these findings suggest that TRPC6 is a novel predisposing gene for ASD that may act in a multiple-hit model. This is the first study to use iPSC-derived human neurons to model non-syndromic ASD and illustrate the potential of modeling genetically complex sporadic diseases using such cells.

A multicharge ion source (Supernanogan) for the OLIS facility at ISAC/TRIUMF.

The Off-Line Ion Source (OLIS) [K. Jayamanna, D. Yuan, T. Kuo, M. MacDonald, P. Schmor, and G. Dutto, Rev. Sci. Instrum. 67, 1061 (1996); K. Jayamanna, Rev. Sci. Instrum. 79, 02711 (2008)] facility consists of a high voltage terminal containing a microwave cusp ion source, either a surface ion source or a hybrid surface-arc discharge ion source [K. Jayamanna and C. Vockenhuber, Rev. Sci. Instrum. 79, 02C712 (2008)], and an electrostatic switch that allows the selection of any one of the sources without mechanical intervention. These sources provide a variety of +1 beams up to mass 30 for Isotope Separator and ACcelerator (ISAC) [R. E. Laxdal, Nucl. Instrum. Methods Phys. Res. B 204, 400 (2003)] experiments, commissioning the accelerators, setting up the radioactive experiments, and for tuning the beam lines. The radio frequency quadrupole (RFQ) [M. Marchetto, Z. T. Ang, K. Jayamanna, R. E. Laxdal, A. Mitra, and V. Zvyagintsev, Eur. Phys. J. Spec. Top. 150, 241 (2005)] injector accelerator is a constant velocity machine designed to accept only 2 keV/u and the source extraction energy is limited to 60 kV. Further stripping is then needed downstream of the RFQ to inject the beam into the drift tube linac [M. Marchetto, Z. T. Ang, K. Jayamanna, R. E. Laxdal, A. Mitra, and V. Zvyagintsev, Eur. Phys. J. Spec. Top. 150, 241 (2005)] accelerator that requires A/q up to 6. Base on this constraints a multicharge ion source capable to deliver beams above mass 30 with A/q up to 6 was needed in order to reach full capability of the ISAC facility. A Supernanogan [C. Bieth et al., Nucleonika 48, S93 (2003)] multicharge ion source was then purchased from Pantechnik and was installed in the OLIS terminal. Commissioning and performance of the Supernanogan with some results such as emittance dependence of the charge states as well as charge state efficiencies are presented.

Off-line ion source terminal for ISAC at TRIUMF.

The off-line ion source (OLIS) terminal consists of a microwave cusp ion source, either a surface ion source or a hybrid surface-arc discharge ion source and an electrostatic switch that allows selecting any one of the sources without mechanical intervention. These sources provide variety of beams to ISAC experiments, for commissioning the accelerators, for setting up the radioactive experiments, and for tuning the beam lines. The microwave ion source has been operational since 1995 and provides singly and doubly charged beams from various stable isotopes for many ISAC experiments at high and low energy areas. Originally its prime goal was to provide beams from gaseous elements, but later two ovens and a sputtering system were added in order to provide beams from liquids and from solids. The surface ion source installed in 2002 can provide low energy spread beams from alkali and semialkali elements. It also has three separate ovens and an ionizer. Therefore, it can provide three different temperature regions simultaneously to provide different beams to ISAC. It is mainly used for laser spectroscopy experiments and other experiments, which require a finite beam quality. A hybrid surface-arc discharge ion source was also developed and installed in order to meet specific demands from experiments. This source terminal is now automated for start up and for mass selection. It is capable of providing stable beams for months without maintenance and it is also capable of providing negative ion beams if required. To date, over 40 different isotopes including many rear isotopes were delivered to various experiments from the OLIS source terminal. Performances of the ion sources and some of the results are discussed.

Repetitive skin-cutting: parental bonding, personality and gender.

OBJECTIVES: This study examines (a) the extent to which repetitive skin-cutting is most prevalent among women and those with a history of trauma; and (b) among those skin-cutters without a history of trauma, the extent to which borderline personality disorder (BPD) features as a primary diagnosis and whether disturbed parental bonding might be associated with this form of self-harm. METHOD: Details of gender and reported experiences of trauma were recorded for a large, consecutive sample of skin-cutters (N=517) who attended a general hospital. Psychiatric diagnoses and parental bonding instrument (PBI) scores were obtained for a subsample of skin-cutters (N=81) and comparison group participants without experiences of trauma. RESULTS: No gender differences were observed among skin-cutters, most of whom reported experiences of trauma. BPD was recorded for a minority of those skin-cutters without a history of trauma. PBI scores discriminated between non-BPD skin cutters and non-BPD comparison participants without a history of trauma. CONCLUSIONS: Although these results provide further confirmation of a potential association between prior trauma and repetitive skin-cutting, they rigorously challenge the validity of reported gender differences for this behaviour. Further, this study has identified that repetitive skin-cutting can arise independently of BPD and prior trauma. Clinical implications of these results and suggested directions for future research are discussed.

An adenovirus vector containing the suicide gene thymidine kinase for a broad application in cancer gene therapy.

Treatment of cancer using gene therapy is based on adding a property to the cell leading to its elimination. One possibility is the use of suicide genes that code for enzymes that transform a pro-drug into a cytotoxic product. The most extensively used is the herpes simplex virus thymidine kinase (TK) gene, followed by administration of the antiviral drug ganciclovir (GCV). The choice of the promoter to drive the transcription of a transgene is one of the determinants of a given transfer vector usefulness, as different promoters show different efficiencies depending on the target cell type. In the experiments presented here, we report the construction of a recombinant adenovirus carrying TK gene (Ad-TK) driven by three strong promoters (P CMV IE, SV40 and EN1) and its effectiveness in two cell types. Human HeLa and mouse CCR2 tumor cells were transduced with Ad-TK and efficiently killed after addition of GCV. We could detect two sizes of transcripts of TK gene, one derived from the close together P CMV IE/SV40 promoters and the other from the 1.5 Kb downstream EN1 promoter. The relative amounts of these transcripts were different in each cell type thus indicating a higher flexibility of this system.

High-rate dissolved air flotation for water treatment.

This paper presents the results of an experimental investigation about the performance of a horizontal flow high-rate pilot scale Dissolved Air Flotation (HRDAF) unit containing inclined parallel plates for treating a coloured and low turbidity raw water. Experiments were performed with the DAF unit in order to verify the influence on flotation of: (i) the water velocity (Vh) between the plates, in the range 18 to 96.5 cm.min-1 with corresponding Reynolds numbers between 240 and 1060; (ii) the supplied air (S*) value ranging from 2.2 to 8.5 g of air/m3 of water; (iii) the angle of the plates (60 degrees or 70 degrees). The best pilot plant operational condition was obtained applying only 4.0 g/m3 (S*) with Vh around 18 cm.min-1 for treatment of water coagulated with a Al2(SO4)3 dosage of 40 mg.l-1. In these conditions, the unit presented very good removal efficiencies of colour (90%, residual of 10 uC), turbidity (88%, residual of 0.8 NTU) and TSS (94%, residual of 1.8 mg.l-1). Furthermore, the unit could operate at higher Vh values up to 76 cm.min-1 and still present good results. The DAF unit thus behaved as a high rate unit presenting good performance with low air requirement.

Daily gastric pH in controls and in duodenal ulcer patients: basal condition and response to treatment.

Gastric pH was monitored, by means of a computerized system, in healthy controls (C) and in patients with active duodenal ulcer (ADU) and inactive duodenal ulcer (IDU). The test was performed before treatment and during administration of a single dose of ranitidine 150 mg, cimetidine 400 mg, and pirenzepine 50 mg, in random sequence at 12-h intervals, (10 am, 10 pm). Under basal conditions, progressively lower median pH values were detected in ADU and IDU patients, compared with controls. A significant difference was found between C and ADU during daytime (1.38 vs. 0.85), nighttime (1.29 vs. 0.81), and 24 h (1.35 vs. 0.81) and between C and IDU during 24 h (1.35 vs. 1.11). However, no statistical difference was observed between patients with active and inactive ulcer disease. Administration of ranitidine and cimetidine significantly increased gastric pH during nighttime but not during daytime. Ranitidine, at the doses studied, proved to be more potent than cimetidine in suppressing gastric acidity. Gastric pH was unaffected by pirenzepine in most cases.

Ultrasonic monitoring of Wirsung duct following secretin in controls and in chronic pancreatitis patients.

Ultrasonic monitoring of the pancreas following secretin stimulation has shown to cause a marked dilatation of Wirsung duct; whether this phenomenon is due to the stimulation of pancreatic secretion and/or to the effect of secretin on the sphincter of Oddi (SO) motility is unknown. In the present study pancreatic scan after secretin was performed in 11 patients with nonpancreatic diseases after premedication with glucagon (inhibition of both pancreatic secretion and SO motility) or tyropramide (inhibition of SO motor function) and in patients with different degrees of pancreatic insufficiency. Serum immunoreactive trypsinogen (IRT) levels were measured in all the subjects during the test. Premedication with glucagon completely abolished both Wirsung enlargement and serum IRT increase, while tyropramide significantly reduced, but did not abolish, the response to secretin. These results suggest that both stimulation of pancreatic secretion and the increase of SO pressure are prerequisites for a full-blown occurrence of the secretin-induced modifications of Wirsung. Within chronic pancreatitis patients, the response to secretin was exaggerated in those with a still preserved pancreatic function and it was lacking in those with severe pancreatic insufficiency.

Comparison of ranitidine and sucralfate in the long-term treatment of duodenal ulcer.

We evaluated long-term treatment with either ranitidine (R) or sucralfate (S) in the prevention of duodenal ulcer recurrences. Fifty-nine patients with healed ulcers were randomly allocated to maintenance treatment with 150 mg R nightly or 2 g/day S. By using a life table analysis, the calculated probable remission rates at 4, 8, and 12 months were 90, 85, and 53% with R, respectively, and 62, 62, and 53% with S, respectively. These differences were not significant at any interval. In both groups ulcer relapse was independent of sex, smoking habit, and alcohol and coffee consumption, whereas a history longer than 5 years was significantly related to a higher probability of recurrence. No relevant clinical or biochemical side effects were encountered with either drug, but compliance rate was higher in the R group. R and S are equally effective in preventing duodenal ulcer relapse over a 1-year period of maintenance treatment, although R proved to be more effective in preventing early relapse.

Evocative test of serum pancreatic enzymes to bombesin in chronic pancreatitis.

The levels of serum immunoreactive trypsinogen and P-isoamylase in response to Bombesin intravenous infusion were evaluated in 25 controls, 18 patients with documented chronic pancreatitis, and nine subjects with nonpancreatic gastroenterological diseases. Mean immunoreactive trypsinogen peak values were significantly higher in controls and gastroenterological diseases than in chronic pancreatitis, but there was marked overlap in individual values between the three groups. As for P-isoamylase, a statistical difference was detected only between mean peak concentrations of control versus chronic pancreatitis. Integrated responses for both enzymes did not result in a better discrimination between controls, chronic pancreatitis, and gastroenterological diseases. This study confirms that evocative tests are of limited value in the diagnosis of pancreatic disease.

A computer-assisted technique for long-term gastric pH monitoring.

A computer-assisted technique for prolonged gastric pH monitoring has been developed using a personal computer. Segments of signal from several studies performed in controls and on patients with duodenal ulcers were chosen for comparison between manual and digital pH readings; no significant difference was detected. In clinical practice this system might provide an additional tool in the diagnostic and therapeutic treatment of peptic ulcer disease.

Diagnostic accuracy of serum cationic trypsinogen estimation for pancreatic diseases.

Serum immunoreactive trypsinogen (IT) levels were measured in 479 normal controls and in 604 patients (510 with nonpancreatic diseases and 94 with pancreatic diseases) in order to evaluate the distribution of IT values in the control population and the accuracy of the assay in the diagnosis of pancreatic diseases. It concentrations were normally distributed in the healthy population; children showed mean IT values significantly lower than adults. The sensitivity, specificity, and predictive value of a positive and negative result in diagnosing acute or chronic pancreatitis were evaluated vs normals and vs normals plus all patients. With an IT value higher than 80 ng/ml, the likelihood that a patient is not affected by acute pancreatitis is less than 5%. An IT value lower than 9 ng/ml detected 44% of chronic pancreatitis and was related to a 52% probability of such a condition. The 48% false positive results also include patients with pancreatic tumor (31% of cases), so that the chance of finding reduced IT levels in subjects without pancreatic damage drops to 17%. In view of the low prevalence of pancreatic diseases, IT assay should not be taken into consideration as a diagnostic screening test in the general population and its use should be limited to a hospitalized population.

Trypsin-like immunoreactivity in the diagnosis of acute pancreatitis.

Elevated serum and urine amylase and serum lipase values are not always diagnostic of an acute pancreatitis, on the account of the extrapancreatic production of these enzymes. A diagnostic improvement can be made by using the CAm/CCr ratio, but this index too is abnormal in some non pancreatic diseases. Since trypsin measurement seems to be more specific in the evaluation of pancreatic condition, serum trypsin-like immunoreactivity has been measured in 28 patients with acute pancreatitis, 95 patients with a wide spectrum of gastroenterological diseases and in 30 patients with severe chronic renal failure. 85 normal subjects were used as controls. Abnormally high serum trypsin-like immunoreactivity (TLI) values were detected in 100% of patients with acute pancreatitis, without any overlap with normal controls. TLI values above the upper normal limit were also found in 70% of patients with severe renal damage, while none of the patients with liver disease, biliary disease, peptic ulcer an inflammatory bowel disease had elevated TLI levels. In 29 patients with hyperamylasemia due to extra-pancreatic diseases serum trypsin-like immunoreactivity was always within the normal range. It is concluded that the determination of serum TLI is a sensitive and reliable tool in the diagnosis of an acute pancreatic inflammation, providing that a severe renal failure is excluded.