Chronic stress attenuates glucocorticoid negative feedback: involvement of the prefrontal cortex and hippocampus

Disruption of the glucocorticoid negative feedback system is observed in approximate one half of human depressives, and a similar condition is induced in animals by chronic stress. This disruption is thought to involve down-regulation of glucocorticoid receptors (GRs) in the feedback sites of the brain. However, the responsible site of the brain has not been well elucidated. Here we examined the effects of chronic stress induced by water immersion and restraint (2 h/day) for 4 weeks followed by recovery for 10 days on the GR levels in the prefrontal cortex (PFC), hippocampus, and hypothalamus of rats using a Western immunoblot technique. In the PFC, the cytosolic GR levels were decreased, but the nuclear GR levels were not changed. In the hippocampus, the levels of cytosolic and nuclear GRs were increased. However, there were no marked changes in the GR levels in the hypothalamus. The changes in the cytosolic GR levels were confirmed at the mRNA level by an in situ hybridization technique. We next examined the suppressive effects of dexamethasone (DEX) infusions into these regions on the circulating corticosterone levels. When DEX was infused into the PFC or hippocampus of the chronically stressed rats, the suppressive response to DEX was abolished, but the response was normal in the hypothalamus. In addition, when DEX was injected systemically to the chronically stressed rats, the suppressive response to DEX was significantly attenuated. These results suggest that the abnormal changes in GRs in the higher centers of the hypothalamo-pituitary-adrenal axis are involved in the chronic stress-induced attenuation of the feedback. Since dysfunction of the PFC or hippocampus is implicated in the pathogenesis of depression, the present findings would help to understand the mechanisms underlying the disrupted feedback system and its relation to brain dysfunction in depression.     

Ia expression in chronic relapsing experimental allergic encephalomyelitis induced by long-term cultured T cell lines in mice

Chronic relapsing experimental allergic encephalomyelitis was induced in SJL mice by adoptive transfer of long-term cultured T cell lines. The T cells which were activated with myelin basic protein (MBP) derived from various species, all induced chronic relapsing experimental allergic encephalomyelitis with a similar high incidence. During the relapsing stage, lymphocytes obtained from the spleen responded well to MBP and were capable of transferring experimental allergic encephalomyelitis, whereas thymus lymphocytes did not respond to MBP. There was no difference in the proliferative response of splenocytes to MBP when splenocytes were isolated either from mice with clinical relapse or from mice that did not relapse. Pathological examination revealed a transient appearance of inflammatory cells during the acute stage. Similar cell infiltrates were also observed at the relapsing stage. The I-region associated (Ia) antigens appeared on vessels and astrocytes in the acute inflammatory lesions which coincided with the appearance of inflammatory cell infiltrates. Ia antigen expression diminished with the disappearance of inflammatory cells. During the relapsing stage, the Ia antigens were also expressed on the vessels and astrocytes in the fresh lesions. Our data indicate that MBP-reactive T cells persist at least in the spleen, for a long time. They may be reactivated by certain mechanisms probably in the central nervous system associated with the Ia-antigen expression, which facilitates the effector phase again. The initial event that triggers the Ia-expression is not known as yet.     

Identification of a Notch3 mutation in a Japanese CADASIL family. Cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy

Cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL) is a hereditary disease that is characterized by recurrent stroke episodes and focal neurologic deficits progressing to pseudobulbar palsy and dementia. The causative gene is the Notch3 gene on chromosome 19, and 22 missense mutations have been identified in Caucasian patients to date. To perform mutational analysis of the Notch3 gene, we identified its exon intron boundaries and prepared sets of primers for amplification of each exon. Using these primers, we determined the Notch3 gene in a Japanese family with CADASIL symptoms and found a missense mutation (Arg133Cys) in exon 4. The mutation was heterozygous and cosegregated with the disease. Thus, the Notch3 gene is responsible for CADASIL in patients across different ethnic groups.     

Is upper mediastinal lymphadenectomy necessary in squamous carcinoma of the lower thoracic oesophagus?

AIM: We examined the indication of upper mediastinal lymphadenectomy for a squamous cell carcinoma of the lower thoracic oesophagus. METHODS: 49 patients underwent a curative oesophagectomy with upper mediastinal lymphadenectomy for a squamous cell carcinoma of the lower thoracic oesophagus. Node status and clinicopathological characteristics of these patients were reviewed retrospectively. RESULTS: 16 (94.1%) of 17 patients with superficial tumours had no positive node in the upper mediastinum. Nine (29.0%) of 31 patients with transmural tumours had positive nodes in the upper mediastinum (P = 0.04). Ten (20.4%) of 49 patients had many positive nodes in the upper mediastinum. Of these 10 patients, 6 patients had 5 or more positive nodes in all. The 5-year survival rate for patients with 5 or more positive nodes was 7.7%, which was significantly poorer than patients with 4 or fewer positive nodes. CONCLUSIONS: Upper mediastinal lymphadenectomy is unnecessary in most of the superficial squamous carcinomas of the lower thoracic oesophagus.     

Accelerated growth signals and low tumor-infiltrating lymphocyte levels predict poor outcome in T4 esophageal squamous cell carcinoma

BACKGROUND: Little is known about the biological nature of T4 esophageal carcinoma growth signals and host defenses. METHODS: Paraffin-embedded sections from 78 patients with T2 to T4 esophageal squamous cell carcinoma who underwent operation were analyzed with immunohistochemistry. RESULTS: Positive cyclin A showed a significantly greater increase in T4 tumors than in those of other stages, and negative p27 showed a significantly greater decrease in T4 tumors than in large T3 stage tumors (tumor size > or = 4.0 cm). Patients with low-grade tumor-infiltrating lymphocyte (TIL) density showed a significantly greater decrease in T4 than in T2. The combination of p27 and cyclin A was a significant independent prognostic factor among T and N factors in multivariate analysis. TIL density was an independent prognostic factor among immunonutritional variables such as serum albumin concentration and the number of total blood lymphocytes. CONCLUSIONS: T4 esophageal squamous cell carcinoma has a poor prognosis, which is associated with increased p27-negative and cyclin A-positive growth signals in the tumor and with low TIL density in the host.     

Alzheimer's disease-associated presenilin 2 interacts with DRAL, an LIM-domain protein

Using the yeast two-hybrid system, we screened for proteins interacting with presenilin 2 (PS2) and cloned DRAL. DRAL is an LIM-only protein containing four LIM domains and an N-terminal half LIM domain. Previously DRAL has been cloned as a co-activator of the androgen receptor and as a protein interacting with a DNA replication regulatory protein, hCDC47. Our yeast two-hybrid assay showed that DRAL interacted with a hydrophilic loop region (amino acids 269-298) in the endoproteolytic N-terminal fragment of PS2, but not that of PS1, although the region 269-298 of PS2 and the corresponding PS1 sequence differ by only three amino acids. Each point mutation within this region, R275A, T280A, Q282A, R284A, N285A, P287T, I288L, F289A and S296A, in PS2 abolished the binding. This suggests that DRAL recognizes the PS2 structure specifically. The in vitro interaction was confirmed by affinity column assay and the physiological interactions between endogenous PS2 and DRAL by co-immunoprecipitation from human lung fibroblast MRC5 cells. Furthermore, in PS2-overexpressing HEK293 cells, we found an increase in the amount of DRAL in the membrane fraction and an increase in the amount of DRAL that was co-immunoprecipitated with PS2. The potential role of DRAL in the cellular signaling suggests that DRAL functions as an adaptor protein that links PS2 to an intracellular signaling.     

Predicting initial recurrence pattern of esophageal cancer after neoadjuvant chemotherapy

BACKGROUND/AIMS: No report has reviewed which clinicopathological factors including 3-field dissection and the response to neoadjuvant chemotherapy can predict the recurrence pattern of an esophageal carcinoma. The aim of this study was to reveal clinicopathological predictors for the initial recurrence pattern of a thoracic esophageal carcinoma. METHODOLOGY: Sixteen parameters derived from 98 patients who underwent a curative esophagectomy with neoadjuvant chemotherapy for a squamous cell carcinoma of the thoracic esophagus were examined using univariate and multivariate logistic regression analyses. RESULTS: Thirty-seven (37.8%) of the 98 patients had recurrences (hematogenous; 16, lymphatic; 13, others; 8). Univariate analyses revealed that the completion of 3-field dissection was the only factor for suppressing the lymphatic recurrence (P = 0.009; odds ratio: 0.2). Multivariate analyses showed that the number of positive nodes was a significant predictor for recurrence including all modalities (P = 0.02; odds ratio: 1.2) and both the number of positive nodes (P = 0.04; odds ratio: 1.1) and the poor response to neoadjuvant chemotherapy (P = 0.02; odds ratio: 6.9) were significant predictors for the hematogenous recurrence. CONCLUSIONS: The number of positive nodes and the response to neoadjuvant chemotherapy could predict the hematogenous recurrence of esophageal carcinoma.     

The effect of repeated cryopreservation and thawing using cryotip on the clinical outcomes of embryos

PurposeTo compare the clinical outcomes of embryo transfers that were cryopreserved and thawed two or three times with those cryopreserved and thawed once by CryoTip.MethodsData for 388 single cryopreserved‐thawed blastocyst transfer cycles, performed from April 2012 to March 2014, were assessed. The blastocysts were classified into three groups: blastocysts (A) cryopreserved once, (B) cryopreserved twice, and (C) cryopreserved three times.ResultsThe pregnancy rate was 43.8% (134/306) in group A and 46.3% (38/82) in group B, while the miscarriage rate was 29.1% (39/134) in group A and 23.7% (9/38) in group B. The rate of improvement/maintenance of blastocyst grade was 84.0% (257/306) in group A and 80.5% (66/82) in group B. The pregnancy and miscarriage rates of the blastocysts that showed improvement/maintenance in the grade were 45.9% (118/257) and 29.7% (35/118) in group A and 48.5% (32/66) and 21.9% (7/32) in group B, respectively. The pregnancy rate was 33.3% (2/6), while the miscarriage rate was 0.0% (0/2) in group C.ConclusionsPregnancy rates achieved with re‐cryopreserved and rethawed blastocyst transfer were comparable to those achieved with single cryopreserved‐thawed blastocyst transfer.     

Activation of effector cells of experimental allergic encephalomyelitis in Lewis rats: comparison of T-cell lines with primary cultured lymph node cells

We studied the mechanism of activation of effector cells in experimental allergic encephalomyelitis (EAE) by using T-cell lines (EAE/TL) reactive against guinea pig myelin basic protein generated from in vivo primed lymph node cells (LNC) of Lewis rats. EAE-effector cells are activated in the presence of a specific antigen and antigen-presenting cells (APC) with a compatible Ia antigen. The antigen presentation occurs during the first 18 h. EAE-effector cells cannot be activated by allogeneic stimulator cells, but a nonspecific T-cell mitogen, concanavalin A, can activate the effector cells in the presence of syngeneic as well as allogeneic APC.