Root of the superior mesenteric artery in pancreatitis and pancreatic carcinoma: evaluation with CT

To determine if changes involving the root of the superior mesenteric artery are specific for neoplasm, the authors retrospectively reviewed 173 computed tomographic (CT) examinations of patients with proved pancreatitis (103 examinations) and pancreatic ductal adenocarcinoma (70 examinations). Streaky infiltration of the fat surrounding the root was seen in 27 of 56 examinations of acute pancreatitis, in four of 24 examinations of chronic pancreatitis, in 12 of 23 examinations of pancreatitis complicated by abscess, and in 25 of 70 examinations of pancreatic carcinoma. Periarterial lymph nodes were visible in 14 with acute pancreatitis, in three with chronic pancreatitis, in six with pancreatic abscess, and in 11 with pancreatic carcinoma. A focal mass extended to within 1 cm of the root in 10 with acute pancreatitis, in two with chronic pancreatitis, in four with pancreatic abscess, and in 24 with pancreatic carcinoma; the mass obliterated the periarterial fat in seven with acute pancreatitis, in one with pancreatic abscess, and in 18 with pancreatic carcinoma. Circumferential encasement occurred in one with chronic pancreatitis, in four with pancreatic abscess, in 14 with pancreatic carcinoma, and in none with acute pancreatitis; nearly all cases of encasement revealed loss of periarterial fat. Thus, these indicators are not specific for neoplasm.     

Non-crosslinked porcine-derived acellular dermal matrix for the management of complex ventral abdominal wall hernias: a report of 45 cases

Purpose

Ventral abdominal wall hernias are common and repair is frequently associated with complications and recurrence. Although non-crosslinked intact porcine-derived acellular dermal matrix (PADM) has been used successfully in the repair of complex ventral hernias, there is currently no consensus regarding the type of mesh and surgical techniques to use in these patients. This report provides added support for PADM use in complex ventral hernias.

Methods

In a consecutive series of adult patients (2008–2011), complex ventral abdominal wall hernias (primary and incisional) were repaired with PADM by a single surgeon. Patient comorbidities, repair procedures, and postoperative recovery, recurrence, and complications were noted.

Results

Forty-four patients (mean age, 57.5 years) underwent 45 single-stage ventral abdominal wall hernia repairs (3 primary; 42 incisional). Previously placed synthetic mesh was removed in 17 cases. In 40 cases, primary fascial closure was achieved; in 5 cases, PADM was used as a bridge. Vacuum-assisted closure (VAC) was used for 38/45 cases: 19 closed incisions, 16 cases using the “French fry” technique, and 3 cases with open incisions. Mean hospital stay was 8.2 days (range, 3–32) and mean follow-up was 17 months (range, 1–48). There were 4 (8.9 %) hernia recurrences, 3 requiring additional repair and 1 requiring PADM explantation. There were 3 (6.7 %) skin dehiscences, 4 (8.9 %) deep wound infections requiring drainage, and 5 (11.1 %) seromas (4 self-limited, 1 requiring drainage).

Conclusions

Non-crosslinked intact PADM yielded favorable early outcomes when used to repair complex ventral abdominal wall hernias in high-risk patients.     

Learning to multitask: effects of video game practice on electrophysiological indices of attention and resource allocation

Changes in attention allocation with complex task learning reflect processing automatization and more efficient control. We studied these changes using ERP and EEG spectral analyses in subjects playing Space Fortress, a complex video game comprising standard cognitive task components. We hypothesized that training would free up attentional resources for a secondary auditory oddball task. Both P3 and delta EEG showed a processing trade-off between game and oddball tasks, but only some game events showed reduced attention requirements with practice. Training magnified a transient increase in alpha power following both primary and secondary task events. This contrasted with alpha suppression observed when the oddball task was performed alone, suggesting that alpha may be related to attention switching. Hence, P3 and EEG spectral data are differentially sensitive to changes in attentional processing occurring with complex task training.     

Human chorionic gonadotropin rise in normal and vanishing twin pregnancies

OBJECTIVE: The purpose of the study was to describe and to compare the rate of rise of human chorionic gonadotropin (hCG) in vanishing twin and normally progressing twin pregnancies during the first trimester. DESIGN: All patients with twin pregnancies between 1985 and 1989 were prospectively studied. Human chorionic gonadotropin was measured one to three times per week between days 12 and 52 after luteinizing hormone (LH) surge or day of hCG administration (day 0). Pelvic ultrasound (US) was performed weekly beginning on day 24. SETTING: The study was performed at Rush-Presbyterian-St. Luke's Medical Center in an academic private practice setting of the Section of Reproductive Endocrinology and Infertility, Department of Obstetrics and Gynecology. PATIENTS: Forty patients who conceived after treatment of infertility and who had two gestational sacs on US examination were included in the study after the following criteria were met: (1) both sacs progressed to exhibit a fetal pole and (2) day of LH surge and/or day of hCG administration was known. MAIN OUTCOME MEASURE: The rate of rise of hCG was slower in vanishing twin pregnancies than in normally progressing twin gestations for the entire time period studied (P less than 0.05). RESULTS: A vanishing twin occurred in one third of the twin pregnancies. Forty-six percent of these losses occurred after fetal heart activity had been established. CONCLUSIONS: Vanishing twin phenomenon occurred in a large proportion of twin pregnancies in this infertility population. Fetal heart activity was not a reliable predictor of continuing fetal viability in early twin gestations. Vanishing twin conceptions were characterized by a slower rate of rise of hCG than normally progressing twin pregnancies.     

Synthesis and biological evaluation of thiol-based inhibitors of glutamate carboxypeptidase II: discovery of an orally active GCP II inhibitor

A series of 2-(thioalkyl)pentanedioic acids were synthesized and evaluated as inhibitors of glutamate carboxypeptidase II (GCP II, EC 3.4.17.21). The inhibitory potency of these thiol-based compounds against GCP II was found to be dependent on the number of methylene units between the thiol group and pentanedioic acid. A comparison of the SAR of the thiol-based inhibitors to that of the phosphonate-based inhibitors provides insight into the role of each of the two zinc-binding groups in GCP II inhibition. The most potent thiol-based inhibitor, 2-(3-mercaptopropyl)pentanedioic acid (IC(50) = 90 nM), was found to be orally bioavailable in rats and exhibited efficacy in an animal model of neuropathic pain following oral administration.     

Examining cortical dynamics and connectivity with simultaneous single-pulse transcranial magnetic stimulation and fast optical imaging

Transcranial magnetic stimulation (TMS) is a widely used experimental and clinical technique that directly induces activity in human cortex using magnetic fields. However, the neural mechanisms of TMS-induced activity are not well understood. Here, we introduce a novel method of imaging TMS-evoked activity using a non-invasive fast optical imaging tool, the event-related optical signal (EROS). EROS measures changes in the scattering of near-infrared light that occur synchronously with electrical activity in cortical tissue. EROS has good temporal and spatial resolution, allowing the dynamics and spatial spread of a TMS pulse to be measured. We used EROS to monitor activity induced in primary motor cortex (M1) by a TMS pulse. Left- and right-hand representations were mapped using standard TMS procedures. Optical sources and detectors mounted on thin rubber patches were then centered on M1 hand representations. EROS was recorded bilaterally from motor cortex while unilateral TMS was simultaneously delivered. Robust ipsilateral EROS activations were apparent within 16 ms of a pulse for TMS delivered to both left and right hemispheres. Clear motor evoked potentials (MEPs) were also elicited by these TMS pulses. Movement artifacts could be excluded as a source of EROS, as no activation was present on short-distance optical channels. For left hemisphere TMS subsequent (40 ms) contralateral activity was also present, presumably due to trans-synaptic propagation of TMS-evoked activity. Results demonstrate that concurrent TMS/EROS is a viable and potentially powerful method for studying TMS-induced activity in the human brain. With further development, this technique may be applied more broadly in the study of the dynamics of causal cortico-cortical connectivity.