Space-time database for standardization of adult magnetocardiogram-making standard MCG parameters

Background: The magnetocardiogram (MCG) is a promising medical tool for detecting and visualizing abnormal cardiac electrical activation in heart-disease patients. However, there is no large-scale MCG database of healthy subjects, and there is little knowledge of gender- and age-related influences on MCG data.
Methods and Results: We obtained MCG data from 869 subjects (554 men, 315 women) using a conventional 64-channel MCG system, which covers the whole heart. Electrocardiogram (ECG) data were also obtained; 464 people (268 men, 196 women) were identified as a normal group using ECG data. Time intervals (PQ, QRS, QT, and QTc), current distributions (maximum current vector (MCV), and the total current vector (TCV)) of MCG data of the 464 normal subjects were analyzed to obtain basic MCG parameters.
Although mean values of PQ and QRS intervals of the male subjects were slightly longer than those of the female subjects, no intervals were correlated with gender or age. The correlation between PQ intervals of ECG and those of MCG was better than the correlation between QRS and QT intervals of ECG and those of MCG. Both MCV and TCV angles were much smaller than the electrical-axis angle in ECG. Although TCVs of the QRS and T waves were stable, the women's mean T-wave-TCV angles significantly increased with age. The maximum amplitude of the P wave was about 1.7 pT, and the value of the QRS complex was about 20–25 pT. Moreover, the T-wave amplitude decreases with age.
Conclusion: The MCG standard space-time parameters determined here provide a normal range for MCG parameters.     

Association of objective measures of trauma exposure from motor vehicle accidents and posttraumatic stress symptoms

Associations of objective measures of trauma exposure with psychological sequelae following motor vehicle accidents (MVA) were examined in a Japanese population. Impact and injury severity of 93 MVA victims was assessed using on-the-scene in-depth investigations measured by the Injury Severity Score (ISS), barrier equivalent speed (BES), and change in velocity during the impact (Delta-v). Results showed that ISS, BES, and Delta-v were not related to posttraumatic stress symptoms (PTSS) or psychiatric symptoms at 5 and 14 months after the MVA. Subjective measures (e.g., perceived life risk, persistent medical problems) were significantly related to psychological sequelae. These findings suggest that the objective measures of trauma exposure are not associated directly with PTSS or psychiatric symptoms after an MVA.     

Tumor Diameter as a Prognostic Factor in Patients with Gastric Cancer

Background  The aim of this study was to evaluate the prognostic value of tumor diameter in gastric cancer. Methods  The study group comprised a series of 1215 patients who underwent curative gastrectomy. The appropriate tumor diameter cutoff value was determined. Prognostic factors were evaluated by univariate and multivariate analyses. Results  The tumor diameter cutoff value was 100 mm. Multivariate analysis showed that tumor site, macroscopic appearance, tumor diameter, depth of invasion, and presence of lymph node metastasis independently affected prognosis in all patients. Multivariate analysis of patients with larger tumors identified depth of invasion as an independent prognostic factor. A comparison between patients with smaller and larger tumors showed marked differences in the survival of those with stage II, IIIA, and IIIB tumors. A comparison of clinicopathological factors between stage II and III patients revealed that tumors occupying the entire stomach, ill-defined, undifferentiated, and serosa-penetrating tumors, and peritoneal metastases were far more frequent in patients with larger tumors. Conclusions  Tumor diameter in gastric cancer is a reliable prognostic factor that might be a candidate for use in the staging system. To improve outcomes for patients with tumors ≥100 mm in diameter, it is necessary to establish therapeutic strategies for peritoneal metastasis, particularly in stage II and III tumors.     

The evaluation of oxidative DNA damage in children with brain damage using 8-hydroxydeoxyguanosine levels

Urinary and cerebrospinal fluid (CSF) levels of 8-hydroxydeoxyguanosine (8-OHdG) were examined to estimate the relevance of oxidative stress in children with brain damage. Urinary 8-OHdG levels were measured in 51 children with various forms of central nervous system (CNS) disorders (status epilepticus [SE], hypoxic-ischemic encephalopathy [HIE], CNS infections and chronic epilepsy) and these levels were compared with those in 51 healthy children. CSF 8-OHdG levels were measured in 25 children with brain damage and in 19 control subjects. In addition, urinary and CSF levels of 8-OHdG were compared between the children with brain damage and healthy children. Finally, the relationship between urinary and CSF levels of 8-OHdG was determined in 12 children that provided both urinary and CSF samples. Our results showed that urinary 8-OHdG levels in children with HIE and CNS infections were higher than those of controls (Steel test; p < 0.05 and p < 0.05, respectively) and that CSF 8-OHdG levels were higher in children with SE, HIE, and CNS infections than in control subjects (Steel test; p < 0.01, 0.05 and 0.05, respectively). In addition, a positive correlation between the levels of urinary and CSF 8-OHdG was noted in the 12 children that provided both CSF and urinary samples (Spearman's rank correlation; rho = 0.82, p < 0.01). Further, we observed changes in the urinary 8-OHdG in a patient with HHV-6 encephalopathy, and found that the changes correlated well with the patient's clinical condition. These results suggest that oxidative stress is strongly related to acute brain damage in children, and that 8-OHdG is a useful marker of brain damage. Therefore, repeated measurements of urinary 8-OHdG may be helpful in estimating the extent of brain damage.     

Augmented brain 5-HT crosses the blood-brain barrier through the 5-HT transporter in rat

The present study re-evaluated an existing notion that serotonin (5-hydroxytryptamine; 5-HT) could not cross the brain to the circulating blood via the blood-brain barrier (BBB). To elevate brain 5-HT alone, 5-hydroxytryptophan (5-HTP; 30-75 mg/kg) was administrated intravenously to anaesthetized rats that had undergone gastrointestinal and kidney resections along with liver inactivation (organs contributing to increasing blood 5-HT after 5-HTP administration). A microdialysis method and HPLC system were used to determine the brain 5-HT levels in samples collected from the frontal cortex. Blood 5-HT levels were determined from whole blood, not platelet-poor plasma, collected from the central vein. We found that blood 5-HT levels showed a significant augmentation whenever brain 5-HT levels were significantly elevated after the administration of 5-HTP in those rats with the abdominal surgical procedures. This elevation was abolished after pretreatment with a selective serotonin reuptake inhibitor (fluoxetine; 10 mg/kg i.v.), although brain 5-HT levels remained augmented. These results indicate that augmented brain 5-HT can cross the BBB through the 5-HT transporter from the brain to the circulating blood.