Otx1 function overlaps with Otx2 in development of mouse forebrain and midbrain

Background: We previously reported that the homozygous mutation of Otx2 gene, a mouse cognate of the Drosophila head gap gene orthodenticle , causes failure in the development of the rostral head anterior to rhombomere 3, which may correspond to earlier Otx2 expression in cells destined for the anterior mesoendoderm. At the same time, the Otx2 heterozygous mutation displayed a phenotype characterized as otocephaly, probably related to expression in the anterior neuroectoderm at the subsequent pharyngula stage. Defects were characteristic in the most anterior and posterior regions of Otx2 expression where Otx1 , another mouse cognate of orthodenticle , is not or weakly expressed. They were not found in the region where Otx1 is expressed.
Results: In the present work, Otx1 null mutant mice were generated by gene targeting in embryonic stem cells. No defects were apparent in the regionalization of the early embryonic rostral brain. The newborn brain defects were subtle and most likely related to later Otx1 -unique expression. Otx1 and Otx2 double heterozygous mutant brains, however, exhibited marked defects throughout the fore- and midbrains, where defects were not apparent with a single mutation alone.
Conclusions: Otx1 and Otx2 play synergistic roles in the development of the forebrain and midbrain where both genes are expressed.     

Enhancement of gap junctional intercellular communication of normal human dermal fibroblasts cultured on polystyrene dishes grafted with poly-N-isopropylacrylamide

Technology developed to allow recovery of cells without enzyme treatment, involving a dish grafted with a thermoreactive polymer gel of poly-N-isopropylacrylamide (PIPAAm), was found to significantly enhance gap junctional intercellular communication (GJIC) in normal human dermal fibroblasts (NHDF cells). NHDF cells were cultured for 4 days on PIPAAm-grafted dishes irradiated with various doses of electron beams, and GJIC was assayed by the scrape-loading dye transfer method. The area of dye transfer was greater in the PIPAAm-grafted dishes than in the control culture dishes, indicating that the PIPAAm-grafted dishes enhanced the GJIC of NHDF cells. Connexin-43 (Cx43) expression was analyzed because Cx43 is considered to be a main component of the gap junctional channel. PIPAAm-grafted dishes irradiated with 100, 250, or 500 kGy of electron beams showed significantly enhanced expression of Cx43-NP, Cx43-P1, and especially Cx43-P2. Enhanced expression of Cx43-P2, a functional transmembrane protein, may be related to the promotion of GJIC. These results suggest that the PIPAAm-grafted dish not only enables the enzyme-free recovery of a cell monolayer for use in the construction of a three-dimensional artificial tissue, but also significantly contributes to the enhancement of GJIC, which may partly promote tissue strength on the surface of the PIPAAm-grafted dish.     

Hand-arm vibration syndrome and its prevalence in the present status of private forestry enterprises in Japan

Summary Currently there are no limitations on age of employment on private forestries in Japan. Hence, it was hypothesized that in these kind of enterprises, elderly chain saw operators, or those with long-term exposure, might be at higher risk of developing hand-arm vibration syndrome (HAVS). We consequently investigated the prevalence of HAVS in 447 chain saw workers on private forestries in Gifu Prefecture, Japan, with particular reference to age and exposure period. Of this population, 43 (9.6%) had signs and symptoms of vibration-induced white finger (VWF), and among these workers the severity of finger blanching was significantly correlated (P < 0.01) with the exposure period. Classification of all subjects by exposure period showed that workers with 30 years' exposure had higher prevalences of VWF (20.9%) and numbness of the hands (25.4%) compared to other groups. Significant differences (P < 0.01) were found between the functional capacities of workers with VWF and those of control subjects. We concluded that (a) the elderly chain saw operators and those with longer exposure should be moved to other jobs with a lower or no risk of exposure to vibration, and (b) the results of screening tests, even without cold water immersion (which we did not employ, in order to protect workers' hands), could be helpful for the identification of workers with VWF.     

Prognosis of the Lennox Syndrome—Long-Term Clinical and Electroencephalographic Follow-up Study, Especially with Special Reference to Relationship with the West Syndrome

The long-term clinical and electroencepha-lographic follow-up studies were carried out for more than three years, up to 14 years in the longest, on 116 cases with Lennox syndrome. And the results of systematic study on changing patterns and outcome have been reported. The follow-up examination was performed also on West syndrome which is closely related with Lennox syndrome; especially the relationship between both syndromes regarding prognosis has been clarified.

• 1 According to the long-term follow-up on 116 cases with Lennox syndrome, there were 98 cases (84.5%) having mental defect. The remaining of seizure was observed in 71 cases (61.2%) and persisted as Lennox syndrome except for one case.
• 2 Generally speaking, the cases with age of onset before two years old showed unfavorable outcome.
• 3 There were 42 cases (36.2%), which were converted from West syndrome and showed markedly unfavorable prognosis in regard to intelligence as well as the remaining of seizure. (31 cases, 77.5%)
• 4 On the other hand, in 23 idiopathic cases, which showed no developmental retardation before onset of seizure, had favorable outcome, and the remaining of seizure was observed in eight cases (34.8%). However, even in such cases, it was noticed that those displaying mental defect at the follow-up attained 14 cases (60.9%). That is to say, it was clarified that persistence of even minor seizures induced mental deterioration.
• 5 The cases with favorable prognosis showed usually a typical slow spike-and-wave pattern electroencephalographically, whereas those with poor prognosis showed mostly an asymmetric or disorganized slow spike-and-wave pattern.
• 6 In many cases displaying signs of brain atrophy with pneumoencephalogram and accompanying overt neurological signs at the initial examination, prognosis is obviously poor.
• 7 From the follow-up examination on 94 cases with West syndrome for three to 15 years, there were 51 cases (54.3%) which was transformed into Lennox syndrome. Among them, those cases with the remaining of seizure at the time of follow-up were 44 (46.8%) out of 94 cases, of which 37 cases (83.8%) had remaining seizure as Lennox syndrome.
• 8 From the above results, it is emphasized that Lennox and West syndromes show close relationship with each other and that a study should be done on the interrelation between their prognosis.

     

心电图同期CT脑血管造影诊断动脉瘤小泡样突起

目的了解心电图同期CT脑血管造影(CTA)技术对于未破裂动脉瘤的小泡样突起诊断的准确性。方法2004年间对15例患者进行了心电图同期CTA检查。结果其中10例患者在心电图同期CTA图像上发现有搏动部位存在,提示动脉瘤上有小泡样突起,手术中也有同样发现。切除的15例动脉瘤标本组织学检查均发现肌层和内弹力层部分或完全缺失,而有小泡的10例动脉瘤中发现胶原层减少,这与小泡样突起的存在相吻合。结论心电图同期CTA可用于未破裂动脉瘤的小泡样突起的诊断,其准确性可用标本的组织学检查加以证明。