Early life stress interrupts brain development through the disturbance of various neurotransmitter and neurotrophic factor activities, but the details remain unclear. In the current study, we focused on the serotonergic system, which plays a critical role in brain development, and examined the time-dependent influence of prolonged maternal separation on male Sprague-Dawley rats. The rats were separated from their dams for 3h twice-daily during postnatal days (PDs) 2-20. The influence of prolonged maternal separation was analyzed on PDs 7, 14, 21, and 28 using HPLC to assess concentrations of serotonin and 5-hydroxyindoleacetic acid and using real-time RT-PCR to measure mRNA expression of the serotonin 1A and 2A receptors in various brain regions. HPLC revealed imbalance between serotonin and 5-hydroxyindoleacetic acid in midbrain raphe nuclei, the amygdala, the hippocampus, and the medial prefrontal cortex (mPFC) on PDs 7 and 14. Furthermore, real-time RT-PCR showed attenuation of mRNA expression of the serotonin 1A receptor in the hippocampus and the mPFC and of the serotonin 2A receptor only in the mPFC on PDs 7 and 14. The observed alterations returned to control levels after maternal separation ended. These findings suggest that the early life stress of prolonged maternal separation disturbs the serotonergic system during a crucial period of brain development, which might in part be responsible for emotional abnormalities later in life.
The PNB classification, which was advocated by Evans and Bernadis, separates the injuries into their effects on 3 components of the fingertip: pulp, nail, and bone. Because each component is subdivided into 7 or 8 items, this can describe fingertip injuries more precisely. Between 1997 and 2003, we treated 381 fingertip injuries (279 males, 102 females; average age, 41.2 years) in our facilities. A 3-digit number was provided for each of the 381 cases in accordance with the PNB classification. We extracted patients in whom amputated tissues did not exist, and predicted the boundary between conservative treatment and surgical treatment by individually comparing the curative results of the same type of injuries. In conclusion, PNB 355-366 and PNB 455-466 were most suitable for surgical treatment, and the boundaries between surgical treatment and conservative treatment were PNB 386 and 666 and 700. The results, which are the criteria for surgical treatment, are summarized as follows; 1) More than two thirds of the distal phalanx remains. 2)The nail bed defect ranges from one third to half. If the defect is more or less than the criteria, the surgical treatment is less significant. Recognition of the boundary and prevention from unnecessary surgical treatment leads to minimum invasive surgery for fingertip injuries.
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