Lignocaine–induced convulsion does not induce c–fos protein (c–Fos) in rat hippocampus

Recent studies have shown that proto–oncogene c–fos mRNA is induced in the central nervous system by a variety of stimuli including generalised convulsions. In this study, the expression of c–fos protein (c–Fos) following lignocaine–induced convulsions was examined and compared with that following convulsions induced by non–anesthetic convulsants, such as pentylenetetrazol, kainic acid and electroconvulsive shocks, in rat brain.
Administration of 120 mg kg^-1 lignocaine by the intraperitoneal route induced generalised convulsions in all rats examined within 10 min. C–Fos was markedly induced in the piriform cortex and amygdala, and slightly induced in the neocortex and thalamus, while no c–Fos expression was observed in the hippocampus. In contrast, c–Fos expression following generalised convulsions induced by non–anaesthetic convulsants was very marked in the hippocampal region, piriform cortex and amygdala, and extended to the thalamus and neocortex.
These results contradict those of previously reported local cerebral metabolic studies using 2–deoxyglucose as a metabolic marker, and suggest that lignocaine–induced convulsions, unlike those induced by non–anaesthetic convulsants, may not cause severe sequelae (plastic changes) in the hippocampus.     

Acute type a aortic dissection complicated with acute inferior myocardial infarction following aortic valve replacement

Acute aortic dissection complicated with acute myocardial infarction (AMI) is the most fatal situation. We experienced the successful treatment for acute type A aortic dissection complicated with inferior AMI following aortic valve replacement (AVR). A 60-year-old man had had AVR for aortic regurgitation. Sixteen months after the AVR, he had a sudden onset of severe chest pain with complete atrioventricular block. Immediately, temporary pacing and cardiac catheterization were conducted, showing the occlusion of the right coronary artery due to acute type A aortic dissection. On his way to our hospital, direct current shock was conducted 3 times for ventricular fibrillation. We replaced the ascending aorta combined with coronary artery bypass grafting and the postoperative course was uneventful. The key to treat acute aortic dissection complicated with AMI is early accurate diagnosis, prompt temporary pacing for bradycardia, defibrillation for lethal arrhythmia and insertion of a perfusion catheter if possible. These preoperative hemodynamic stabilization gives us the chance to save these patients.     

Variation analysis of β3-adrenergic receptor and melanocortin-4 receptor genes in childhood obesity

BACKGROUND: Decreased energy expenditure and increased food intake are principal causes for obesity. In the present study, genotypes of beta(3)-adrenergic receptor (beta(3)AR) and of melanocortin-4 receptor (MC4R), both of which are believed to have a close link to the cause of obesity, were analyzed and compared with phenotypes of childhood obesity. METHODS: Thirty-five obese children with moderate to severe obesity were enrolled. Direct sequencing of the MC4R coding region and pinpoint-polymerase chain reaction were used to detect genomic variation in the beta(3)AR gene using peripheral blood-derived DNA. RESULTS: Allele frequency of Trp64Arg variation in the beta(3)AR gene in the obese subjects was 0.16, which is comparable with that in the healthy general population in eastern Asia. Comparison of phenotypical characteristics did not show a significant difference between Trp/Trp and Trp/Arg subjects. It was notable that body height SD was significantly higher in the Trp/Trp than the Trp/Arg subjects (0.93 +/- 1.0 SD vs 0.07 +/- 1.3 SD, P= 0.03). Annual weight gains were far beyond a hypothetical fat gain in an Arg64 heterozygote with decreased energy consumption, suggesting increased food intake in childhood obesity. There was, however, no variation in the MC4R gene despite thorough sequencing of the entire coding region. CONCLUSIONS: The Trp64Arg variation in the beta(3)AR gene has no relationship to the degree or the incidence of childhood obesity. The majority of childhood obesity can be characterized as tall stature, more rapid weight gain than that expected by decreased energy expenditure. Further investigation is necessary in regard to the increased food intake as a major cause of childhood obesity.     

Video-assisted thoracoscopic wedge resection of solitary pulmonary metastasis from hepatocellular carcinoma

We report a metastatic pulmonary tumor resected by video-assisted thoracoscopic surgery. A 63-year-old female was found to have four nodules of hepatocellular carcinoma (HCC) in January 1991; after non-surgical treatment, the tumors had become necrotic. In June 1992, a new HCC nodule was found. After infusion chemotherapy, it became necrotic. In September 1993, a solitary lung tumor, 2.4 cm in diameter, appeared at the periphery of the right lung. Because the tumor was considered to be a metastatic HCC rather than a primary lung cancer, it was removed by thoracoscopic wedge resection. Although whether metastasectomy contributes to prolongation of survival is still controversial, thoracoscopic pulmonary resection may be indicated for solitary peripheral metastasis, if the primary HCC is well controlled by multidisciplinary treatment.     

New perspectives on tooth development and the dental stem cell niche

Adult stem cells have the capacity to self-renew and differentiate along multiple lineages in addition to contributing to ongoing tissue maintenance and regeneration after injury. They reside in specific locations called stem cell niches. In biology of the tooth, the discovery of dental epithelial stem cells in continuously growing teeth has been a recent breakthrough. The niche for the adult stem cells of these teeth is formed at the region of the apical end in tooth development. The region possesses a commonly specialized histological structure for the maintenance of adult stem cells and the production of various progenitor cells producing dental tissues. The molecular signals regulating the maintenance and cell fate decision of adult stem cells, such as Notch1, Lunatic fringe, fibroblast growth factor (FGF)-10, are expressed in the epithelial structure and the surrounding mesenchyme. Based on histological and molecular biological studies, we propose a new concept that the eternal tooth buds producing various dental progeny are formed at the apical end in the development of continuously growing teeth, and coin a new term of "apical bud" for indicating this specialized epithelial structure. Furthermore, the relationship between signaling centers and the expression of FGF-10 mRNA as the determinant of morphogenesis is discussed with an emphasis on tooth and limb development, taking note that the expression pattern of FGF-10 is an important key for understanding the mechanisms for the diversity of cusp patterns and between continuous and limited growth.     

Establishment of dental epithelial cell line (HAT-7) and the cell differentiation dependent on Notch signaling pathway

Rat incisors grow continuously throughout life. Producing a variety of dental epithelial cells is performed by stem cells located in the cervical loop of the incisor apex. To study the mechanisms for cell differentiation, we established a dental epithelial cell line (HAT-7) originating from a cervical loop epithelium of a rat incisor. Immunochemical studies showed that HAT-7 produced the cells expressing amelogenin, ameloblastin, or alkaline phosphatase (ALP). To illustrate a role of Notch signaling in the determinant of the cell fate, we examined expression patterns of Notch1 and Jagged1 in HAT-7 density dependently. At lower cell density, Notch1- or Jagged1-expressing cells were not seen. However, when they were fully confluent, cells began to express Notch1 or Jagged1 strongly. Some ALP-positive cells were almost consistent with Notch1-expressing cells but not Jagged1-expressing cells. These results suggested that the determinant of direction of differentiation was associated with Notch signaling pathway.     

IL-6-STAT3 controls intracellular MHC class II alphabeta dimer level through cathepsin S activity in dendritic cells

We found IL-6-STAT3 pathway suppresses MHC class II (MHCII) expression on dendritic cells (DCs) and attenuates T cell activation. Here, we showed that IL-6-STAT3 signaling reduced intracellular MHCII alphabeta dimmer, Ii, and H2-DM levels in DCs. IL-6-mediated STAT3 activation decreased cystatin C level, an endogenous inhibitor of cathepsins, and enhanced cathepsin activities. Importantly, cathepsin S inhibitors blocked reduction of MHCII alphabeta dimer, Ii, and H2-DM in the IL-6-treated DCs. Overexpression of cystatin C suppressed IL-6-STAT3-mediated increase of cathepsin S activity and reduction of MHCII alphabeta dimer, Ii, and H2-DM levels in DCs. Cathepsin S overexpression in DCs decreased intracellular MHCII alphabeta dimer, Ii, and H2-DM levels, LPS-mediated surface expression of MHCII and suppressed CD4(+) T cell activation. IL-6-gp130-STAT3 signaling in vivo decreased cystatin C expression and MHCII alphabeta dimer level in DCs. Thus, IL-6-STAT3-mediated increase of cathepsin S activity reduces the MHCII alphabeta dimer, Ii, and H2-DM levels in DCs, and suppresses CD4(+) T cell-mediated immune responses.     

Intravenous glycerol therapy should not be used in patients with unrecognized fructose-1,6-bisphosphatase deficiency

BACKGROUND: In Asian countries, glycerol solution that contains fructose (5%) is often used for management of brain edema. However, glycerol and fructose may cause severe hypoglycemia and metabolic acidosis in patients with fructose-1,6-bisphosphatase (FBPase) deficiency, even under stable conditions. The aim of the present study was to determine whether glycerol solution was used for brain edema during acute metabolic decompensation of hypoglycemia and metabolic acidosis in patients with unrecognized FBPase deficiency in Japan and to examine a long-term prognosis of the patients who had this kind of severe metabolic decompensation with or without glycerol therapy. METHODS: A retrospective study of 20 children with FBPase deficiency was conducted, based on their medical records. RESULTS: Six of the 20 children were given glycerol solution for the presence or possibility of brain edema during acute metabolic decompensation of hypoglycemia and metabolic acidosis; two of the six patients administered with glycerol were given dialysis. In four patients treated with glycerol alone without dialysis, two had no brain edema before glycerol administration but it developed later after the administration. These four patients treated with glycerol alone died or developed severe neurological complications. Fourteen patients who were not treated with glycerol solution had no brain edema and showed good prognosis. CONCLUSIONS: Glycerol solution, which contains fructose in Asian countries including Japan, should not be used as an osmotic agent for treatment of brain edema in patients who have hypoglycemia and retention-type metabolic acidosis, until FBPase deficiency is ruled out by measuring blood concentration of lactate.