Search

BACKGROUND: The 'default network' consists of a number of brain regions that exhibit correlated low-frequency activity at rest and that have been suggested to be involved in the processing of self-relevant stimuli. Activity in many of these areas has also been shown to be altered in individuals with posttraumatic stress disorder (PTSD). We hypothesized that the posterior cingulate cortex (PCC)/precuneus, part of the default network, would exhibit altered connectivity at rest with other areas of the default network and regions associated with PTSD. METHODS: Seventeen medicated and unmedicated female patients with chronic posttraumatic stress disorder (PTSD) related to early-life trauma and 15 healthy female controls underwent a 5.5-minute functional magnetic resonance imaging scan with their eyes closed. We assessed areas of the brain whose activity positively and negatively correlated with that of the PCC/precuneus in both groups. RESULTS: At rest, spontaneous low-frequency activity in the PCC/precuneus was more strongly correlated with activity in other areas of the default network in healthy controls than in patients with PTSD. Direct comparison of the 2 groups showed that PCC/ precuneus connectivity was also greater in healthy controls than in patients with PTSD in a number of areas previously associated with PTSD, including the right amygdala and the hippocampus/parahippocampal gyrus. LIMITATIONS: Because our PTSD sample comprised only women with chronic early-life trauma exposure, our results may not be generalizeable to male patients, to a population with single trauma exposure or to those who were adults when the trauma occurred. In addition, our sample included patients taking medication and it is not yet clear how altered connectivity is affected by medication. CONCLUSION: Spontaneous activity in the default network during rest, as measured using PCC correlations, is altered in patients with PTSD. The potential effects of psychotropic medications on default network connectivity in the present sample remain unknown. In this patient population, the observed alterations may be associated with the disturbances in self-referential processing often observed in patients with chronic PTSD related to early-life trauma. [ABSTRACT FROM AUTHOR]

There is a general expectation that urban populations will be fragmented and the movement of individuals will be restricted leading to low effective population sizes, low genetic diversity, higher inbreeding, and higher differentiation than populations living in more continuous habitat. In this study, we compare the genetic diversity and differentiation of Texas horned lizards that are found in four small towns (Kenedy, Karnes City, Rockdale, and Smithville) in Texas and at Tinker Air Force Base, Oklahoma to populations that occur in 16 natural areas and to an introduced population in South Carolina. We also present more detailed spatial genetic data and home range data for several of the towns. Texas horned lizards ( Phrynosoma cornutum ) living in small towns have lower genetic diversity, higher differentiation, and smaller effective population sizes than populations located in more natural areas. There was evidence for human-mediated movement of lizards into town; however, it has not been enough to counteract the effects of drift. Home range size is smaller in town than in more natural areas. Genetic patterns suggest dispersal occurs over short distances and is inhibited across areas with a high percent of impervious surface and major roads. These data suggest that effective planning to maintain suitable habitat and corridors to facilitate movement is critical to maintaining small terrestrial species like the Texas horned lizard and must be integrated into the early stages of urban development., Competing Interests: The authors declare no conflicts of interest., (© 2024 The Author(s). Ecology and Evolution published by John Wiley & Sons Ltd.)

Background: Endoscopic ultrasound-directed transgastric endoscopic retrograde cholangiopancreatography (ERCP; EDGE) is an alternative to enteroscopy- and laparoscopy-assisted ERCP in patients with Roux-en-Y gastric bypass anatomy. Although short-term results are promising, the long-term outcomes are not known. The aims of this study were: (1) to determine the rates of long-term adverse events after EDGE, with a focus on rates of persistent gastrogastric or jejunogastric fistula; (2) to identify predictors of persistent fistula; (3) to assess the outcomes of endoscopic closure when persistent fistula is encountered., Methods: This was a multicenter retrospective study involving 13 centers between February 2015 and March 2019. Adverse events were defined according to the ASGE lexicon. Persistent fistula was defined as an upper gastrointestinal series or esophagogastroduodenoscopy showing evidence of fistula., Results: 178 patients (mean age 58 years, 79 % women) underwent EDGE. Technical success was achieved in 98 % of cases (175/178), with a mean procedure time of 92 minutes. Periprocedural adverse events occurred in 28 patients (15.7 %; mild 10.1 %, moderate 3.4 %, severe 2.2 %). The four severe adverse events were managed laparoscopically. Persistent fistula was diagnosed in 10 % of those sent for objective testing (9/90). Following identification of a fistula, 5 /9 patients underwent endoscopic closure procedures, which were successful in all cases., Conclusions: The EDGE procedure is associated with high clinical success rates and an acceptable risk profile. Persistent fistulas after lumen-apposing stent removal are uncommon, but objective testing is recommended to identify their presence. When persistent fistulas are identified, endoscopic treatment is warranted, and should be successful in closing the fistula., Competing Interests: A.L. Chang has received consultancy fees and research support from Boston Scientific; T.E. Kowalski has received consultancy fees from Boston Scientific and Medtronic; T.H. Baron has received consultancy fees from Boston Scientific, Cook Endoscopy, W.L. Gore, Medtronic, and Olympus America, and speaker’s fees from Medtronic; J. Nieto has received consultancy fees from Boston Scientific and Olympus America, and speaker’s fees from AbbVie; J.Y. Nasr has received consultancy fees from Boston Scientific; H.S. Khara has received consultancy fees from Boston Scientific and speaker’s fees from Olympus America, Covidien, Gyrus ACMI, Inc., and US Endoscopy; S. Irani has received research support from Boston Scientific; R.J. Law has received consultancy fees from Boston Scientific, Olympus America, and ERBE, and research support from Cook Medical; D.E. Loren has received consultancy fees from Boston Scientific and Olympus America; D.L. Diehl has received consultancy fees from Boston Scientific, Cook Endoscopy, Olympus America, Pentax Medical, Lumendi, US Endoscopy, and C2 Therapeutics, and speaker’s fees from Boston Scientific and Olympus America; M.A. Al-Haddad has received consultancy fees and research support from Boston Scientific; D.K. Pleskow has received consultancy fees from Boston Scientific, Olympus, Fuji, Nine Point Medical, and Medtronic; M. Huggett has received consultancy fees from Boston Scientific and Cook Endoscopy, and speaker’s fees from Boston Scientific, Cook Endoscopy, and Olympus; A.J. Trindade has received consultancy fees from Olympus America, C2 Therapeutics, and Pentax Medical; V. Kumbhari has received consultancy fees from Apollo Endosurgery, Boston Scientific, Medtronic, Pentax Medical, and ReShape Lifescience, and research support from ERBE, C2 Therapeutics, and Ovesco; M.A. Khashab has received consultancy fees from and is on the advisory board of Boston Scientific and Olympus America, and has received consultancy fees from Medtronic. The remaining authors declare that they have no conflict of interest., (Thieme. All rights reserved.)

Backgrounds: Endoscopic ultrasound (EUS)-guided placement of lumen-apposing metal stents (LAMSs) has gained popularity for the treatment of pancreatic walled-off necrosis (WON). We compared the 20-mm and 15-mm LAMSs for the treatment of symptomatic WON in terms of clinical success and adverse events., Methods: We conducted a retrospective, case-matched study of 306 adults at 22 tertiary centers from 04/2014 to 10/2018. A total of 102 patients with symptomatic WON who underwent drainage with 20-mm LAMS (cases) and 204 patients who underwent drainage with 15-mm LAMS (controls) were matched by age, sex, and drainage approach. Conditional logistic regression analysis was performed to compare clinical success (resolution of WON on follow-up imaging without reintervention) and adverse events (according to American Society for Gastrointestinal Endoscopy criteria)., Results: Clinical success was achieved in 92.2 % of patients with 20-mm LAMS and 91.7 % of patients with 15-mm LAMS (odds ratio 0.92; P  = 0.91). Patients with 20-mm LAMS underwent fewer direct endoscopic necrosectomy (DEN) sessions (mean 1.3 vs. 2.1; P  < 0.001), despite having larger WON collections (transverse axis 118.2 vs. 101.9 mm, P  = 0.003; anteroposterior axis 95.9 vs. 80.1 mm, P  = 0.01). There was no difference in overall adverse events (21.6 % vs. 15.2 %; P  = 0.72) and bleeding events (4.9 % vs. 3.4 %; P  = 0.54) between the 20-mm and 15-mm LAMS groups, respectively., Conclusions: The 20-mm LAMS showed comparable clinical success and safety profile to the 15-mm LAMS, with the need for fewer DEN sessions for WON resolution., Competing Interests: Drs. Arlt, Ellrichmann, Aparicio, Sejpal, Irani, Pawa, Ahmed, Sedarat, Hampe, Sharaiha, Berzin, Stevens, Willingham, Kushnir, Ngamruengphong, Hugget, Baron, Repici, Adler, Nasr, Kowalski, Kumbhari, and Khashab are consultants for Boston Scientific. Dr. Trindade is a consultant for Pentax Medical and CSA Medical. Dr. Benias is a consultant for Fujifilm, Medtronic, and Apollo. Dr. Sejpal is also a consultant for Olympus America. Dr. Ahmed is also a consultant for Cook Medical. Dr. Hampe is also a consultant for Cook Medical, Olympus America, and B. Braun. Dr. Sharaiha is also a consultant for Olympus America and Apollo. Dr. Chahal is a consultant for Medtronic. Dr. Willingham is also a consultant for RedPath, Cook Medical, Xlumena, Oncolys Biopharma, and has received research funding to the university from Cancer Prevention Pharmaceuticals. Dr. Hugget is also a consultant for Cook Medical. Dr. Repici has also received research funding from Boston Scientific. Dr. Kumbhari is also a consultant for Medtronic, Reshape Lifesciences, and Apollo Endosurgery, and has received research support from ERBE and Apollo Endosurgery. Dr. Singh is a consultant for Abbvie and Novo Nordisk, and is a member of an advisory board for Akcea. Dr. Khashab is also a consultant for Olympus America and Medtronic. All other authors have no conflict of interest to disclose., (© Georg Thieme Verlag KG Stuttgart · New York.)

The present study sought to elucidate the functional contributions of sub-regions of the swallowing neural network in swallowing preparation and swallowing motor execution. Seven healthy volunteers participated in a delayed-response, go, no-go functional magnetic resonance imaging study involving four semi-randomly ordered activation tasks: (i) "prepare to swallow," (ii) "voluntary saliva swallow," (iii) "do not prepare to swallow," and (iv) "do not swallow." Results indicated that brain activation was significantly greater during swallowing preparation, than during swallowing execution, within the rostral and intermediate anterior cingulate cortex bilaterally, premotor cortex (left > right hemisphere), pericentral cortex (left > right hemisphere), and within several subcortical nuclei including the bilateral thalamus, caudate, and putamen. In contrast, activation within the bilateral insula and the left dorsolateral pericentral cortex was significantly greater in relation to swallowing execution, compared with swallowing preparation. Still other regions, including a more inferior ventrolateral pericentral area, and adjoining Brodmann area 43 bilaterally, and the supplementary motor area, were activated in relation to both swallowing preparation and execution. These findings support the view that the preparation, and subsequent execution, of swallowing are mediated by a cascading pattern of activity within the sub-regions of the bilateral swallowing neural network.

OBJECTIVE The goal of this study was to compare the recovery of neuronal metabolism and functional reorganization in the primary motor cortex (M1) between mild and moderate cervical spondylotic myelopathy (CSM) following surgical intervention. METHODS Twenty-eight patients with CSM underwent 3-T MRI scans that included spectroscopy and functional MRI, before surgery and 6 months postsurgery. The classification of severity was based on the modified Japanese Orthopaedic Association questionnaire. Mild and moderate myelopathy were defined by modified Japanese Orthopaedic Association scores > 12 of 18 (n = 15) and 9-12 (n = 13), respectively. Ten healthy control subjects underwent 2 MRI scans 6 months apart. Metabolite levels were measured in the M1 contralateral to the greater deficit side in patients with CSM and on both sides in the controls. Motor function was assessed using a right finger-tapping paradigm and analyzed with BrainVoyager QX. RESULTS Patients with mild CSM had a lower preoperative N-acetylaspartate to creatine (NAA/Cr) ratio compared with moderate CSM, suggesting mitochondrial dysfunction. Postsurgery, NAA/Cr in moderate CSM decreased to the levels observed in mild CSM. Preoperatively, patients with mild CSM had a larger volume of activation (VOA) in the M1 than those with moderate CSM. Postoperatively, the VOAs were comparable between the mild and moderate CSM groups and had shifted toward the primary sensory cortex. CONCLUSIONS The NAA/Cr ratio and VOA size in the M1 can be used to discriminate between mild and moderate CSM. Postsurgery, the metabolite profile of the M1 did not recover in either group, despite significant clinical improvement. The authors proposed that metabolic impairment in the M1 may trigger the recruitment of adjacent healthy cortex to achieve functional recovery.

Objectives: Total pancreatectomy with islet autotransplantation (TPIAT) is increasingly performed with remote islet cell processing and preparation, i.e., with islet cell isolation performed remotely from the primary surgical site at an appropriately equipped islet isolation facility. We aimed to determine whether TPIAT using remote islet isolation results in comparable long-term glycemic outcomes compared with TPIAT performed with standard local isolation., Methods: We performed a retrospective cohort study of adult patients who underwent TPIAT at three tertiary care centers from 2010 to 2013. Two centers performed remote isolation and one performed local isolation. Explanted pancreata in the remote cohort were transported ∼130 miles to and from islet isolation facilities. The primary outcome was insulin independence 1 year following transplant., Results: Baseline characteristics were similar between groups except the remote cohort had higher preoperative hemoglobin A1c (HbA1c; 5.43 vs. 5.25, P=0.02) and there were more females in the local cohort (58% vs. 76%, P=0.049). At 1 year, 27% of remote and 32% of local patients were insulin independent (P=0.48). Remote patients experienced a greater drop in fasting c-peptide (-1.66 vs. -0.64, P=0.006) and a greater rise in HbA1c (1.65 vs. 0.99, P=0.014) at 1-year follow-up. A preoperative c-peptide >2.7 (odds ratio (OR) 4.4, 95% confidence interval (CI) 1.6-14.3) and >3,000 islet equivalents/kg (OR 11.0, 95% CI 3.2-37.3) were associated with one-year insulin independence in the local group., Conclusions: At 1 year after TPIAT, patients undergoing remote surgery have equivalent rates of long-term insulin independence compared with patients undergoing TPIAT locally, but metabolic control is superior with local isolation.

Purpose To characterize longitudinal metabolite alterations in the motor cortex of patients with cervical spondylotic myelopathy (CSM) by using proton magnetic resonance (MR) spectroscopy and to evaluate white matter integrity with diffusion-tensor imaging in patients who are recovering neurologic function after decompression surgery. Materials and Methods Informed written consent was obtained for all procedures and the study was approved by Western University's Health Sciences Research Ethics Board. Twenty-eight patients with CSM and 10 healthy control subjects were prospectively recruited and underwent two separate 3-T MR imaging examinations 6 months apart. Patients with CSM underwent surgery after the first examination. N-acetylaspartate (NAA), an indicator of neuronal mitochondrial function, normalized to creatine (Cr) levels were measured from the motor cortex contralateral to the greater functional deficit side in the patient group and on both sides in the control group. Fractional anisotropy and mean diffusivity were measured by means of diffusion-tensor imaging in the white matter adjacent to the motor and sensory cortices of the hand and the entire cerebral white matter. Clinical data were analyzed by using Student t tests. Results In patients with CSM, NAA normalized to Cr (NAA/Cr) levels were significantly lower 6 months after surgery (1.48 ± 0.08; P < .03) compared with preoperative levels (1.73 ± 0.09), despite significant improvement in clinical questionnaire scores. Fractional anisotropy and mean diffusivity were the same (P > .05) between the patient and control groups in all measured regions at all time points. Conclusion NAA/Cr levels decreased in the motor cortex in patients with CSM 6 months after successful surgery. Intact white matter integrity with decreased NAA/Cr levels suggests that mitochondrial metabolic dysfunction persists after surgery. © RSNA, 2016 Online supplemental material is available for this article.

Objectives: Total pancreatectomy with islet autotransplantation is increasingly being performed remotely, that is, removing the pancreas in 1 location, isolating the islet cells in another location, then returning the islets to the original location for reimplantation into the patient. We determined the influence of extended cold ischemia time on key clinical outcomes in remote islet autotransplantation., Methods: We evaluated patients who underwent remote islet autotransplantation at 2 centers from 2011 to 2014. Patients were divided into 2 groups: those with and those without a decrease in C-peptide greater than 50% from baseline. The primary clinical outcome was the quantity of isolated islet equivalents per kilogram body weight (IEQs/kg)., Results: Twenty-five patients met inclusion criteria; 15 had a decrease in C-peptide greater than 50% from baseline and had lower corresponding IEQs/kg compared with those without a decrease greater than 50% (4045 vs 6654 IEQs/kg, P = 0.01). There was no difference in cold ischemia time between the 2 groups (664 vs 600 minutes, P = 0.25). Daily insulin use at 1 year nearly met statistical significance (25.3 vs 8 U, P = 0.06), as did glycated hemoglobin (8.07 vs 6.69 mmol/L, P = 0.06)., Conclusions: Cold ischemia time does not influence islet yield in patients undergoing pancreatectomy with remote isolation.

OBJECTIVE Cervical spondylotic myelopathy (CSM) is the most common cause of reversible spinal cord dysfunction in people over the age of 55 years. Following surgery for symptomatic CSM, patients demonstrate motor improvement early in the postoperative course, whereas sensory improvement can lag behind. The authors of the present study hypothesized that changes in the concentration of N-acetylaspartate (NAA) in the motor and sensory cortices in the brain would emulate the time course of neurological recovery following decompression surgery for CSM. Their aim was to compare and contrast how metabolite levels in the motor and sensory cortices change after surgery to reverse downstream spinal cord compression. METHODS Twenty-four patients with CSM and 8 control subjects were studied using proton MR spectroscopy ( 1 H-MRS) images acquired on a 3.0-T Siemens MRI unit. The 1 H-MRS data (TE 135 msec, TR 2000 msec) were acquired to measure absolute levels of NAA from the motor and sensory cortices in the cerebral hemisphere contralateral to the side of greater deficit at baseline in each subject. Data were also acquired at 6 weeks and 6 months following surgery. Control subjects were also evaluated at 6 weeks and 6 months following baseline data acquisition. Neurological function was measured in each subject at all time points using the Neck Disability Index (NDI), modified Japanese Orthopaedic Association (mJOA) questionnaire, and the American Spinal Injury Association (ASIA) neurological classification. RESULTS In the motor cortex of patients, NAA levels decreased significantly (p < 0.05) at 6 weeks and 6 months postsurgery compared with baseline levels. In the sensory cortex of patients, NAA levels decreased significantly (p < 0.05) only at 6 months after surgery compared with baseline and 6-week levels. No significant changes in NAA were found in control subjects. Clinical scores demonstrated significant (p < 0.05) motor recovery by 6 weeks, whereas sensory improvements (p < 0.05) appeared at only 6 months. CONCLUSIONS Findings suggest that metabolite changes in both the motor and sensory cortices mimic the time course of functional motor and sensory recovery in patients with CSM. The temporal course of neurological recovery may be influenced by metabolic changes in respective cortical regions.

Context: Total pancreatectomy (TP) with islet cell autotransplantation (IAT) can reduce or prevent diabetes by preserving beta cell function and is normally performed with on-site isolation laboratory facilities., Objective: We examined factors associated with islet yield and metabolic outcomes in patients with chronic pancreatitis undergoing TP-IAT. We report our experience of TP-IAT with an off-site islet isolation laboratory., Patients and Methods: Data (August 2008 to February 2014) were obtained from a TP-IAT database which included information from medical records, clinic visits, questionnaires, and follow-up telephone calls. Each patient was assessed with pre- and postoperative 5-hour mixed-meal tolerance tests for metabolic measurements and with serial glycosylated hemoglobin (HbA1c) determinations., Results: Thirty-six patients with a mean age of 38 years (range, 16-72 y) underwent TP-IAT for different etiologies. At a median follow-up time of 28 months (range, 3-66 mo), 12 patients were insulin independent and 24 patients were on at least one insulin injection a day. Postoperatively, C-peptide levels ≥0.3 ng/mL were present in 23/33 (70%) of the patients, with a median fasting C-peptide value of 0.8 ng/mL (range, <0.2-1.5 ng/mL). Those who were insulin independent were more likely to be female (P = .012), have normal morphology on pre-operative pancreatic imaging (P = .011), and have significantly higher median islet yield (6845 islet equivalent numbers [IEQ]/kg, n = 12 vs 3333 IEQ/kg, n = 24; P < .001)., Conclusions: IAT after TP performed in our facility with an off-site islet isolation laboratory shows islet yield and rates of insulin independence that are comparable to other large centers with on-site laboratories.

A new type of contrast agent for Xe NMR based on surfactant-stabilized perfluorocarbon-in-water nanoemulsions has been produced. The contrast agent uses dissolved hyperpolarized xenon gas as a nonperturbing reporting medium, as xenon freely exchanges between aqueous solution and the perfluorocarbon interior of the droplets, which are spectroscopically distinguishable and allow for chemical exchange saturation transfer (CEST) detection of the agent. Nanoemulsions with droplet diameters between 160 and 310 nm were produced and characterized using hyperpolarized (129)Xe combined with CEST detection. Saturation parameters were varied and data were modeled numerically to determine the xenon exchange dynamics of the system. Nanoemulsion droplets were detected at concentrations as low as 100 fM, corresponding to <1 μL of perfluorocarbon per liter of solution. The straightforward, inexpensive production of these agents will facilitate future development toward molecular imaging and chemical sensing applications.

A hyperpolarized 129Xe contrast agent composed of many cryptophane-A molecular cages assembled on an M13 bacteriophage has been demonstrated. Saturation of xenon bound in the large number of cryptophane cages is transferred to the pool of aqueous-solvated xenon via chemical exchange, resulting in efficient generation of hyperCEST contrast. No significant loss of contrast per cryptophane cage was observed for the multivalent phage when compared with unscaffolded cryptophane. Detection of this phage-based hyperCEST agent is reported at concentrations as low as 230 fM, representing the current lower limit for NMR/MRI-based contrast agents., (Copyright © 2012 Wiley Periodicals, Inc.)

The Tm(3+) chelate of DOTAM [1,4,7,10-tetrakis(carbamoylmethyl)-1,4,7,10-tetraazacyclododecane] possessing sterically demanding t-butyl amide substitution favors TSAP geometry. This chelate displayed a paraCEST signal associated with the highly shifted amide proton signal at approximately -100 ppm that was beyond the frequency of macromolecule magnetization transfer. This signal also displayed high temperature dependence (0.57 ppm °C(-1)) in the range of 35-42 °C and at neutral pH., (Copyright © 2013 John Wiley & Sons, Ltd.)

Objective: To explore the functional neural correlates of emotional numbing symptoms in individuals with posttraumatic stress disorder (PTSD)., Method: The study was conducted between September 2006 and June 2008 at the University of Western Ontario. Women with (n = 14) and without (n = 16) PTSD (based on DSM-IV criteria) completed a standardized emotional imagery task while undergoing functional magnetic resonance imaging, in addition to an assessment for emotional numbing symptoms. The study design was correlational, with primary outcome measures being blood oxygenation level-dependent (BOLD) response to emotional imagery task and self-reported severity of emotional numbing symptoms. Women without PTSD were not trauma exposed., Results: In women with PTSD, emotional numbing symptoms predicted less positive affect in response to positive-valence scripts (P < .05) and less BOLD response within the dorsomedial prefrontal cortex during imagery of positive and negative scripts that were explicitly socially relevant (P < .001). In contrast, in women without PTSD, emotional numbing symptoms, while unrelated to subjective emotional responses, predicted greater response within the ventromedial prefrontal cortex during positive and negative scripts, in addition to scripts that elicited fear anxiety by nonsocial means (all P values < .001). The findings could not be attributed to dysphoria., Conclusions: These findings are consistent with previous research regarding emotional numbing and emotional awareness. Less response within the medial prefrontal cortex during emotional imagery in individuals with high emotional numbing may indicate deficient conscious and reflective emotional processing. Further study is required to elucidate associations between state and trait emotional numbing and the neural correlates of psychological treatments specific to emotional numbing., (© Copyright 2012 Physicians Postgraduate Press, Inc.)

Emotion theory emphasizes the distinction between social vs non-social emotional-processing (E-P) although few functional neuroimaging studies have examined whether the neural systems that mediate social vs non-social E-P are similar or distinct. The present fMRI study of script-driven imagery in 20 women demonstrates that social E-P, independent of valence, more strongly recruits brain regions involved in social- and self-referential processing, specifically the dorsomedial prefrontal cortex, posterior cingulate/precuneus, bilateral temporal poles, bilateral temporoparietal junction and right amygdala. Functional response within brain regions involved in E-P was also significantly more pronounced during negatively relative to positively valenced E-P. Finally, the effect for social E-P was increased for positive relative to negative stimuli in many of these same regions. Future research directions for social and affective neuroscience are discussed.

Individuals with posttraumatic stress disorder (PTSD) often exhibit deficits in emotional experience and expression, which suggests that certain individuals with PTSD may be alexithymic. In this study, in a sample of 105 individuals with PTSD, clinical correlates of alexithymia included reexperiencing, hyperarousal, numbing, dissociative symptoms, and retrospectively reported experiences of childhood emotional neglect. In a subsample of 26 individuals with PTSD related to a motor vehicle accident, functional neural responses to trauma-script imagery were associated with severity of alexithymia, including increased right posterior-insula and ventral posterior-cingulate activation and decreased bilateral ventral anterior-cingulate, ventromedial prefrontal, anterior-insula, and right inferior frontal cortex activation. Clinical and theoretical implications and future research directions are discussed., ((c) 2008 APA, all rights reserved)

The goal of this study was to compare neural activation patterns in patients with PTSD with and without current comorbid major depression. Traumatized subjects with PTSD (n=11), PTSD+major depression (MDD, n=15), and subjects (n=16) who met criterion A for PTSD but never developed the disorder were studied using the script-driven symptom-provocation paradigm adapted to functional magnetic resonance imaging (fMRI) at a 4-Tesla field strength. Both the PTSD+MDD and PTSD-MDD groups revealed decreased brain activation in the anterior cingulate gyrus (BA 24) and the right ventrolateral prefrontal cortex (BA 47). After covariation for differences in PTSD severity between these groups, the left insula (BA 13) remained more significantly activated in the PTSD-MDD group than in the PTSD+MDD group. In contrast, the PTSD+MDD group showed greater activation than the PTSD-MDD group in the bilateral anterior cingulate gyrus (BA 24) and posterior cingulate cortices (BA 23, 31). These results suggest different patterns of brain activation related to comorbid major depression occurring in the context of PTSD.

Purpose: To design and apply a method to quantitatively evaluate the MR compatibility of electroencephalographic (EEG) scalp electrodes based on pulse sequence-independent metrics., Materials and Methods: Three types of electrodes (constructed primarily of brass, silver, and conductive plastic, respectively) were tested. B0 field distortions, B1 shielding, and heat induction was measured in adjacent agarose and oil phantoms at 4 T. B0 field maps were corrected for distortions caused by the measurement apparatus and passive shim heating, and projections perpendicular to the surfaces of the electrodes were fit, generating cubic coefficients representing the electrode distortion severity. Signal loss in T2-weighted images was used to determine B1 shielding by the electrodes. Temperature measurements were recorded during the application of a high-power pulse sequence., Results: Significantly different B0 distortions were observed in the three types of electrodes. The B1 shielding detected in all three electrodes is minimal for most human MRI, and no significant heating was detected in the electrodes or adjacent phantom., Conclusion: The three types of electrodes were successfully differentiated in terms of MR compatibility based on pulse sequence-independent B0 field distortions., (Copyright (c) 2007 Wiley-Liss, Inc.)

Brain-imaging studies have shown that visually-cued, voluntary swallowing activates a distributed network of cortical regions including the precentral and postcentral gyri, anterior cingulate cortex (ACC), insula, frontoparietal operculum, cuneus and precuneus. To elucidate the functional contributions of these discrete activation foci for swallowing, a "Go, No-Go" functional magnetic resonance imaging (fMRI) paradigm was designed. Brain activation associated with visually-cued swallowing was compared with brain activation evoked by a comparable visual cue instructing the subject not to swallow. Region-of-interest analyses performed on data from eight healthy subjects showed a significantly greater number of activated voxels within the precentral gyrus, postcentral gyrus, and ACC during the "Go" condition compared to the "No-Go" condition. This finding suggests that the precentral gyrus, postcentral gyrus, and ACC contribute primarily to the act of swallowing. In contrast, the numbers of activated voxels within the cuneus and precuneus were not significantly different for the "Go" and "No-Go" conditions, suggesting that these regions mediate processing of the cue to swallow. Together these findings support the view that the discrete cortical foci previously implicated in swallowing mediate functionally distinct components of the swallowing act.

Although multiple regions of the cerebral cortex have been implicated in swallowing, the functional contributions of each brain area remain unclear. The present study sought to clarify the roles of these cortical foci in swallowing by comparing brain activation associated with voluntary saliva swallowing and voluntary tongue elevation. Fourteen healthy right-handed subjects were examined with single-event-related functional magnetic resonance imaging (fMRI) while laryngeal movements associated with swallowing and tongue movement were simultaneously recorded. Both swallowing and tongue elevation activated 1) the left lateral pericentral and anterior parietal cortex, and 2) the anterior cingulate cortex (ACC) and adjacent supplementary motor area (SMA), suggesting that these brain regions mediate processes shared by swallowing and tongue movement. Tongue elevation activated a larger total volume of cortex than swallowing, with significantly greater activation within the ACC, SMA, right precentral and postcentral gyri, premotor cortex, right putamen, and thalamus. Although a contrast analysis failed to identify activation foci specific to swallowing, superimposed activation maps suggested that the most lateral extent of the left pericentral and anterior parietal cortex, rostral ACC, precuneus, and right parietal operculum/insula were preferentially activated by swallowing. This finding suggests that these brain areas may mediate processes specific to swallowing. Approximately 60% of the subjects showed a strong functional lateralization of the postcentral gyrus toward the left hemisphere for swallowing, whereas 40% showed a similar activation bias for the tongue elevation task. This finding supports the view that the oral sensorimotor cortices within the left and right hemispheres are functionally nonequivalent.

It is important for primary care physicians to take fecal incontinence seriously and not dismiss it as a normal part of aging. Elderly patients may be reluctant to admit fecal incontinence, so clinicians need to ask about it. Two of the most common causes are fecal impaction (especially in nursing home patients) and rectosphincter dysfunction in people with diabetes.

Germline transformation of the major African malaria vector, Anopheles gambiae, was achieved using the piggyBac transposable element marked with the enhanced green fluorescent protein (EGFP) injected into mosquito embryos. Two G1 generation male mosquitoes expressing EGFP were identified among 34 143 larvae screened. Genomic Southern data and sequencing of the piggyBac insertion boundaries showed that these two males arose from one piggyBac insertion event in the injected G0 embryos. Genetic cross data suggest that the insertion site of the element either resulted in, or is tightly linked to, a recessive lethal. This was demonstrated by a deficiency in the number of EGFP-expressing offspring from inbred crosses but expected ratios in outcrosses to non-transformed individuals and failure to establish a pure-breeding line. The insertion was weakly linked to the collarless locus on chromosome 2 and was shown by in situ hybridization to be located in division 28D of that chromosome. Particularly high levels of expression were observed uniformly in salivary glands and, in most individuals, in the anterior stomach. An improvement in the injection technique at the end of the studies resulted in increased G0 hatching, transient expression and EGFP-expression rates among G1 progeny.