Similar frontal and distinct posterior cortical regions mediate visual and auditory perceptual awareness

Activity in ventral visual cortex is a consistent neural correlate of visual consciousness. However, activity in this area seems insufficient to produce awareness without additional involvement of frontoparietal regions. To test the generality of the frontoparietal response, neural correlates of auditory awareness were investigated in a paradigm that previously has revealed frontoparietal activity during conscious visual perception. A within-experiment comparison showed that frontal regions were related to both visual and auditory awareness, whereas parietal activity was correlated with visual awareness and superior temporal activity with auditory awareness. These results indicate that frontal regions interact with specific posterior regions to produce awareness in different sensory modalities.     

Overtriage in trauma – what are the causes?

BACKGROUND: Different criteria are employed to activate trauma teams. Because of a growing concern about overtriage, the objective of this study was to investigate the performance of our trauma team's activation protocol. METHODS: Injured patients with trauma team activation (TTA), admission to an intensive care unit or surgical intermediate care unit with a trauma diagnosis, or trauma-related death in the emergency department were investigated retrospectively from 1 January 2004 to 31 December 2005. Different TTA criteria were analysed with respect to sensitivity, positive predictive value (PPV) and overtriage (1 - PPV). RESULTS: Eight hundred and nine patients were included, 185 (23%) of whom had an Injury Severity Score (ISS) of more than 15. The performance of our protocol showed a sensitivity of 87%, PPV of 22% and overtriage of 78%. The mechanism of injury as a TTA criterion had a sensitivity of 14%, PPV of 7% and overtriage of 93%. Physiological/anatomical criteria and interfacility transfer showed higher PPV and less overtriage. Undertriage (no TTA despite ISS > 15) was identified in 23 patients (13%), 18 of whom were hospital transfers. CONCLUSION: A TTA protocol based on physiological, anatomical and interfacility transfer criteria seems to yield a higher precision than, in particular, that based on mechanism of injury criteria. Because of substantial overtriage in our hospital, the TTA protocol needs to be re-evaluated.     

Effect of Surgery on the Outcome of Midgut Carcinoid Disease with Lymph Node and Liver Metastases

We have evaluated survival and tumor-related symptoms in the presence of mesenteric lymph node and liver metastases in relation to surgical procedures in 314 patients (148 women, mean age at diagnosis 61 years; 249 with liver metastases) treated for midgut carcinoid tumors. Of the operated patients, 46% presented with severe abdominal pain and intestinal obstruction and were operated on before the diagnosis. Medical treatment (somatostatin analogs, interferon-a) was initiated in 67% and 86%, respectively. Surgical attempts included small intestine or ileocecal/right-sided colon resection with excision of mesenteric lymph node metastases. Most of the patients (n = 286) had mesenteric lymph node metastases; 33% of them had unresectable mesenteric lymph node metastases and underwent surgery without mesenteric dissection. Patients who underwent resection for the primary tumor had a longer survival than those with no resection (median survival 7.4 vs. 4.0 years; p <0.01). Patients who underwent successful excision of mesenteric metastases had a significantly longer survival than those with remaining lymph node metastases. Patients operated on for a primary tumor but with remaining lymph nodes but no liver metastases and who subsequently received interferon and somatostatin analog treatment had a median survival of 7.4 years. Resection of the primary tumor and the mesenteric lymph node metastases led to a significant reduction in tumor-related symptoms. Surgery to remove the primary intestinal tumor including mesenteric lymph node metastases is supported by the present results, even in the presence of liver metastases. Liver metastases and significant preoperative weight loss are identified as major negative prognostic factors for survival.     

Ketorolac is not nephrotoxic in connection with sevoflurane anesthesia in patients undergoing breast surgery

Ketorolac, which may cause renal vasoconstriction by cyclooxygenase inhibition, is often administered to patients anesthetized with sevoflurane that is metabolized to inorganic fluoride (F(-)), another potential nephrotoxin. We assessed this possible interaction using urine N-acetyl-beta-D-glucosaminidase indexed to urinary creatinine (U-NAG/crea) as a marker of proximal tubular, beta2-microglobulin as a tubular, urine oxygen tension (P(u)O(2)) as a medullary, and erythropoietin as a marker of tubulointerstitial damage. Thirty women (ASA physical status I-II) undergoing breast surgery were included in our double-blinded study. They were allocated into two groups receiving either ketorolac 30 mg IM (Group K) or saline (Group C) at the time of premedication, at the end of, and 6 h after anesthesia maintained with sevoflurane. Urine output, U-NAG/crea, P(u)O(2,) serum creatinine, urea, and F(-) were assessed. Blood loss was larger in Group K (465 +/- 286 mL vs 240 +/- 149 mL, mean +/- SD, P < 0.05). The MAC-doses of sevoflurane were similar. U-NAG/crea increased during the first 2 h of anesthesia and serum F(-) peaked 2 h after the anesthesia without differences between the groups. There were no statistically significant changes in P(u)O(2), erythropoietin, beta2-microglobulin, serum creatinine, urea, or urine output during anesthesia or the recovery period in either group. Our results indicate that the kidneys are not affected by ketorolac administered in connection with sevoflurane anesthesia. IMPLICATIONS: The different kinetics of N-acetyl-beta-D-glucosaminidase indexed to urinary creatinine and serum inorganic fluoride during and after sevoflurane anesthesia suggest that the observed mild renal tubular function deterioration is not caused by inorganic fluoride. Administration of ketorolac IM is therefore considered safe in adequately hydrated healthy adult patients given sevoflurane anesthesia.     

CCN2 is transiently expressed by keratinocytes during re-epithelialization and regulates keratinocyte migration in vitro by the ras-MEK-ERK signaling pathway

Background

CCN2 (previously known as connective tissue growth factor) is a multifunctional matricellular protein that has numerous effects on cell life and cell interactions with the connective tissue. Although the importance of CCN2 for the fibrotic process in wound healing has been well studied, the involvement of CCN2 in keratinocyte function has not yet been explored. Therefore, the aim of the present study was to investigate the role of CCN2 in the epidermis during wound healing.

Materials and methods

Immunohistochemistry was done on sections from full-thickness porcine wounds. The effect of CCN2 on the migration of cultured human keratinocytes exposed to scratch wounds, the effect on phosphorylation of extracellular signal-related kinases (ERK), and the effect of adding inhibitors to the ERK/mitogen-activated protein kinase pathway to human keratinocytes were studied.

Results

The CCN2 protein was transiently expressed in vivo at the leading keratinocyte edge during re-epithelialization of full-thickness porcine wounds. In vitro, exogenous addition of CCN2 to human keratinocyte cultures regulated keratinocyte migration and resulted in phosphorylation of ERK. The addition of inhibitors of ERK/mitogen-activated protein kinase counteracted the effect of CCN2 on migration.

Conclusions

CCN2 was transiently expressed at the leading keratinocyte edge in vivo. The biologic importance of this was supported in vitro, because CCN2 regulated human keratinocyte migration through activation of the Ras-mitogen-activated protein kinase kinase-ERK signal transduction pathway.     

Distinct Pharmacologic Properties of Neuromuscular Blocking Agents on Human Neuronal Nicotinic Acetylcholine Receptors: A Possible Explanation for the Train-of-four Fade

Background: Nondepolarizing neuromuscular blocking agents (NMBAs) are extensively used in the practice of anesthesia and intensive care medicine. Their primary site of action is at the postsynaptic nicotinic acetylcholine receptor (nAChR) in the neuromuscular junction, but their action on neuronal nAChRs have not been fully evaluated. Furthermore, observed adverse effects of nondepolarizing NMBAs might originate from an interaction with neuronal nAChRs. The aim of this study was to examine the effect of clinically used nondepolarizing NMBAs on muscle and neuronal nAChR subtypes.

Methods: Xenopus laevis oocytes were injected with messenger RNA encoding for the subunits included in the human [alpha]1[beta]1[varepsilon][delta], [alpha]3[beta]2, [alpha]3[beta]4, [alpha]4[beta]2, and [alpha]7 nAChR subtypes. The interactions between each of these nAChR subtypes and atracurium, cisatracurium, d-tubocurarine, mivacurium, pancuronium, rocuronium, and vecuronium were studied using an eight-channel two-electrode voltage clamp setup. Responses were measured as peak current and net charge.

Results: All nondepolarizing NMBAs inhibited both muscle and neuronal nAChRs. The neuronal nAChRs were reversibly and concentration-dependently inhibited in the low micromolar range. The mechanism (i.e., competitive vs. noncompetitive) of the block at the neuronal nAChRs was dependent both on subtype and the NMBA tested. The authors did not observe activation of the nAChR subtypes by any of the NMBAs tested.