Theta phase locking across the neocortex reflects cortico-hippocampal recursive communication during goal conflict resolution

EEG theta coherence, EEG theta power and subjective levels of response were examined in a continuous monitoring target detection task where periodic goal conflicts were introduced as 34 participants progressed through a stimulus sequence leading to response. EEG theta coherence revealed increases in phase locking between cortical areas at specific task stages involving goal conflict. Theta power also increased at points of goal conflict. The temporal characteristics of subjective response (measured continuously throughout the task) indicated a delay between participants actually experiencing goal conflict and overt indications of conflict. The starting point for the study was based on a specific aspect of Gray and McNaughton's [Gray, J.A., McNaughton, N., 2000. The Neuropsychology of Anxiety: An Enquiry into the Functions of the Septo-Hippocampal System, 2nd ed. Oxford University Press, Oxford] behavioural inhibition system model—namely, septo-hippocampal system involvement in the resolution of goal conflicts. We drew on Gray and McNaughton's [Gray, J.A., McNaughton, N., 2000. The Neuropsychology of Anxiety: An Enquiry into the Functions of the Septo-Hippocampal system, 2nd ed. Oxford University Press, Oxford] suggestion that septo-hippocampal involvement in this process is reflected by EEG theta. While their theory explains many of our findings, we also drew upon Given's [Givens, B., 1996. Stimulus-evoked reseting of the dentate theta rhythm: relation to working memory. Neuroreport 8 (1), 159–163] proposal that the dentate theta rhythm is reset by behaviourally relevant stimuli. We made further proposals based on Makeig et al.'s [Makeig, S., Westerfield, M., Jung, T.-P., Enghoff, S., Townsend, J., Courchesne, E., Sejnowski, T.J., 2002. Dynamic brain sources of visual evoked responses. Science 295, 690–694] view that specific stimulus events invoke concurrent phase resetting and transient frequency domain coherence across different areas of neocortex. Relations with Go/NoGo event related potentials (P300 and N2; e.g., [Bokura, H., Yamaguchi, S., Kobayashi, S., 2001. Electrophysiological correlates of response inhibition in a Go/NoGo task. Clin. Neurophysiol. 112 (12), 2224–2232]) were also discussed, as well as parallels between our data and interpretation, and other theoretical models of theta (e.g., [Kahana, M.J., Selig, D., Madsen, J.R., 2001. Theta returns. Curr. Opin. Neurobiol. 11, 739–744]). Suggestions for further research were made.     

Electrophysiological Signs of Neurocognitive Deficits in Long-Term Leukemia Survivors

The long-term effects of disease and treatment on electrophysiologicalmeasures of neurocognitive function were studied in childrenwho had survived acute lymphoblastic leukemia (ALL) for at least4 years and were currently in remission. We report here changesin cognitive processing time as shown by the latency of theP3 wave of the auditory event-related EEG potential (ERP). P3latency was significantly prolonged in long-term ALL surivors,as well as in patients successfully trreated for solid tumors(ST)outside the CNS who received similar chemotherapy but did notreceive prophylactic treatment to the CNS. P3 latencies werestrongly correlated with measures of school performance andIQ in these individuals. The similarity in P3 latency betweenthe ALL and ST groups suggests that the treatments used on thesepateints produce changes in electrophysiological responses thatare associated with mild, but significant, cognitive deficits.     

Base deficit stratifies mortality and determines therapy.

OBJECTIVE: To determine the association of base deficit with mortality and other factors affecting mortality. DESIGN: Retrospective review. SETTING: Tertiary care center. PARTICIPANTS: Consecutive samples of 3791 trauma patients admitted with an arterial blood gas sample taken in the first 24 hours. MAIN OUTCOME MEASURES: Age, injury mechanism, head injury, shock (systolic blood pressure less than 90 mm Hg), Revised Trauma Score, TRISS probability of survival Ps, and mortality. RESULTS: Most (3038) patients (80.1%) exhibited a base deficit. Base deficit, age, injury mechanism, and head injury were associated with mortality using logistic regression. Age less than 55 years, no head injury, and a base deficit of -15 mmol/L were associated with 25% mortality. Age greater than or equal to 55 years with no head injury or age less than 55 years with a head injury and a base deficit of -8 mmol/L were associated with a 25% mortality. When shock was added to the model, all factors remained significant, and base deficit was supplemental to blood pressure. Base deficit also added significantly to the Revised Trauma Score and TRISS measurements. CONCLUSIONS: The base deficit is an expedient and sensitive measure of both the degree and the duration of inadequate perfusion. It is useful as a clinical tool and enhances the predictive ability of both the Revised Trauma Score and TRISS.     

Comparison of Plasma Metabolite Concentrations and Enzyme Activities in Beef Cattle Raised by Different Feeding Systems in Korea,Japan and New Zealand

Concentrations of metabolites and immunoreactive insulin (IRI) and activities of enzymes related to energy metabolism were measured in plasma of Korean and Japanese beef cattle, which were raised by the indoor feeding system programmed to feed larger amount of roughage in their growing periods and larger amount of concentrate diet in their finishing periods (Japanese feeding system), and grazing New Zealand beef cattle. By the Japanese beef grading system, Korean and Japanese beef cattle showed high beef quality score, average grade 3.3 and 3.6, respectively. The plasma free fatty acid and lactate concentrations and lactate dehydrogenase (LDH), malate dehydrogenase (MDH) and aspartate aminotransferase (AST) activities in Korean beef cattle were significantly higher than those in Japanese beef cattle. The plasma lactate concentration in Korean beef cattle was 8.40 mmol/l, which was similar to the values observed in lactic acidosis. The higher activities of plasma LDH, MDH and AST may indicate slight liver damage by slightly acidotic conditions in Korean beef cattle. New Zealand beef cattle fed on pasture which they harvest by grazing showed significantly lower plasma glucose, cholesterol, lactate and IRI concentrations and enzyme activities than those in Korean and Japanese beef cattle fed on larger amount of concentrate diets. Plasma metabolite concentrations and energy metabolism‐related enzyme activities may be good indicators for evaluating metabolic conditions of beef cattle raised by different feeding systems.     

Interaction of epidermal growth factor, Ca2+, and matrix metalloproteinase-9 in primary keratinocyte migration

Elevations of epidermal growth factor (EGF) and Ca²⁺ concentrations in the wound site are associated with reepithelialization during wound healing. In addition, Ca²⁺ and EGF can both induce increases in matrix metalloproteinase‐9 (MMP‐9) synthesis. However, little is known about the interplay of these events in regulating the migration properties of primary keratinocytes on collagen I, the most abundant extracellular matrix component in the skin. We found that EGF stimulated both chemokinetic and chemotactic migration of primary keratinocytes on collagen I; however, MMP‐9 was required for EGF‐stimulated chemotaxis but not EGF‐stimulated chemokinesis. Calcium at 0.5 mM stimulated chemokinetic migration of keratinocytes. Together, Ca²⁺ and EGF stimulated higher levels of chemokinesis than either stimulus alone. Furthermore, Ca²⁺ could restore the ability of keratinocytes from MMP‐9 null mice to undergo EGF‐stimulated chemotaxis. The phosphatidylinositol‐3 kinase inhibitor LY294002 inhibited both EGF‐ and Ca²⁺‐stimulated chemokinetic migration. In contrast, the MEK inhibitor PD98059 blocked Ca²⁺‐ but not EGF‐stimulated chemokinetic migration of keratinocytes. A combination of PD98059 and LY294002 was required to inhibit Ca²⁺ enhancement of EGF‐stimulated migration completely. Calcium‐stimulated chemokinesis was completely blocked by either the protein kinase C‐α inhibitor Gö6976 or the src/fyn inhibitor PP2. Using primary keratinocytes, our results showed how the combined action of Ca²⁺, EGF, and MMP‐9 regulated the contributions of extracellular‐regulated kinase and phosphatidylinositol‐3 kinase toward chemokinetic and chemotactic migration of keratinocytes.     

Congenital disorder of glycosylation type 1a: three siblings with a mild neurological phenotype.

We report 3 siblings (1 male and 2 female) recently diagnosed with congenital disorder of glycosylation type Ia (CDG-Ia) in their mid-20s. They experience mild mental retardation but manage to function independently in society. Their professions are library assistant, professional artistic painter and secretarial work. All three siblings have cerebellar hypoplasia and ataxia, but are able to ambulate easily. Two of the siblings have required strabismus surgical repairs. All have antithrombin III deficiency, osteoporosis, and mild dysmorphic features. Hypergonadotrophic hypogonadism was a feature of the two female siblings. A type 1 sialotransferrin pattern and phosphomannomutase (PMM) deficiency have been demonstrated. They are compound heterozygotes for R141H and L32R mutations in the PMM2 gene. While there is clinical heterogeneity in CDG-Ia, we believe that our patients are among the mildest of intellectually affected CDG-Ia patients reported to date.