Structural modification of WC-Co cutting tools by laser doping treatment.

We have previously shown that sharpening the cutting edge of a cemented carbide tool by chemical-mechanical polishing (CMP) improved the cutting speed by approximately 150% and reduced the wear on the flank surface by approximately 50% compared to a commercial tool when cutting a heat-resistant alloy. In addition, the cutting edges of carbide tools treated by laser doping (LD) using boron nitride as doping material achieved approximately 100 times longer cutting distance in glass machining than the edges of carbide tools treated with CMP grinding wheels. In this study, LD was conducted on a tool base material (WC-Co) to investigate and understand the crystal structure changes of the base material upon treatment. Electron backscatter diffraction and X-ray diffraction results show that the effect of LD was observed in the region 50 nm below the surface. LD improved the strength by approximately 11.7% without destroying the surface crystal structure. Thus, doping can be performed on tool tips while maintaining the WC structure to improve the performance of WC-Co cutting tools.

Association between the nutritional status and the severity of sarcopenia among community-dwelling elderly Japanese people.

AIM: To investigate the association between nutritional evaluation indices (body mass index, albumin, and weight loss) and sarcopenia severity among community-dwelling elderly people in Japan. METHODS: The subjects consisted of 758 community-dwelling elderly people ≥65 years of age, categorized into two groups by based on Operation of long life medical care system (medical care system for elderly in the latter stage of life), the cut-off value for age used was 75. The outcome measures were basic characteristics, anthropometric measures, physical function, and blood biochemistry (five assessments). The appendicular skeletal muscle mass was calculated via a bioelectrical impedance analysis. The subjects were categorized into three groups by the body mass index (BMI) [BMI 3 group]. The cut-off value for albumin used was 3.8 g/dL [A1b 2 group]. Weight loss was assessed using item 11 on the Kihon check list: "Have you experienced more than 2-3 kg weight loss over the past 6 months? Yes=1, No=0." [weight loss 2 group]. Sarcopenia was defined based on the European Working Group on Sarcopenia in Older People definition, using the Asian Working Group for Sarcopenia cut-off values. All subjects were then categorized into four groups based on their sarcopenia status: non-sarcopenic (non-), pre-sarcopenic (pre-), sarcopenic (sarco-), or severely sarcopenic (severe-) [sarco4 group]. RESULTS: The prevalence of sarcopenia and severe sarcopenia in men was 5.6% (n=18) and 1.2% (n=4), respectively, and in women was 7.8% (n=34) and 1.6% (n=7), respectively. The analysis showed that, among the people (>75 years of age) with normal BMI (18.5-25.0), 10.4%-15.6% were in the Sarco group. Further, among women over 75 years of age with BMI >25.0, 5.7% (n=2) were in the Sarco group. There was a significant association between weight loss and sarcopenia severity in older men. No significant association between albumin levels and sarcopenia severity was observed. 80.0% of weight-loss was presented in above BMI 18.5 kg/m2 and Alb 3.8 g/dL. CONCLUSION: Sarcopenia and severe sarcopenia were prevalent among those with normal BMI, and particularly among obese women over 75 years of age. Weight-loss was presented in above BMI 18.5 kg/m2 and Alb 3.8 g/dL. Our findings indicate that the nutritional evaluation indices, including BMI, albumin, and weight loss, were insufficient in screening for malnutrition and sarcopenia among the elderly.

[Perioperative Blood Pressure Changes in a Patient Undergoing One-stage Bilateral Nephrectomy for Treatment-resistant Hypertension].

We describe our experience with a 15-year-old girl receiving anesthesia during one-stage bilateral nephrectomy for treatment-resistant hypertension due to chronic renal failure. Approximately 10 minutes after removal of both kidneys, a reduction in blood pressure associated with decreased cardiac contractile force was observed and this necessitated catecholamine administration. However, blood pressure was sufficiently improved approximately 60 minutes later, and catecholamine administration was not necessary after she awoke from anesthesia. Although administration of an antihypertensive agent as required after surgery, as had been the case before surgery, the dose was gradually tapered and we were able to stop drug administration on postoperative day 31.

[Epidural blood patch for postdural puncture headache in a five-year-old child].

A case was presented of a 5-year-old girl who suffered an accidental dural puncture during placement of an epidural catheter under general anesthesia for orthopedic surgery. She complained of headache 4 days after the operation, which was relieved on supine position but became worse on sitting position. Her symptoms failed to respond to conservative management. An epidural blood patch was performed under general anesthesia and completely resolved her symptoms. The reported incidence of epidural blood patch for post dural puncture headache following accidental dural puncture in children is low. We outline this case and the consideration for management for epidural blood patch in pediatric patients.

Anxiolytic effect of a herbal medicine, yokukansan, in aged rats: involvement of serotonergic and dopaminergic transmissions in the prefrontal cortex.

AIM OF THE STUDY: Aging is thought to affect emotions including anxiety, and a herbal medicine, yokukansan (YKS), is used to treat emotional disturbances associated with age-related neurodegenerative disorders such as Alzheimer's disease, but its pharmacological properties have not been fully understood. The present study was designed to examine whether YKS improves age-related anxiety using F344/N aged rats. Moreover, the effects of YKS on liver function were examined. MATERIALS AND METHODS: YKS was administered to 21-month-old aged rats for 3 months. Locomotor activity of young control (4 months old), aged control (24 months old), and YKS-treated aged rats was examined, and the anxiety-related responses of these animals were evaluated by counting the number of excrements during locomotor activity measurement and in the elevated plus-maze test. The extracellular concentrations of serotonin and dopamine in the prefrontal cortex (PFC) were also measured using a microdialysis technique. Moreover, concentrations of aspartate aminotransferase (AST), alanine aminotransferase (ALT), and ammonia (NH(3)) in plasma were measured. RESULTS: Although locomotor activity did not change among any experimental groups, the number of excrements was significantly increased in aged rats compared to young rats, and this increase was significantly improved by YKS treatment. Aged rats also showed significant decreases in time and frequency in the open arm of the elevated plus-maze, and these decreases were significantly improved by YKS treatment. Extracellular concentrations of serotonin and dopamine in the aged PFC were significantly decreased; serotonin was increased over the level of young rats and dopamine was partially improved by YKS treatment, respectively. In addition, YKS improved age-related increase in NH(3) concentration, but did not affect AST and ALT. CONCLUSIONS: YKS has improving activity for age-related increased anxiety and enhances serotonergic and dopaminergic transmissions in the aged PFC. These mechanisms provide information important for the treatment of anxiety in the elderly. Furthermore, the present data confirm partially the Kampo concept "liver disease".

Saikokaryukotsuboreito, a herbal medicine, prevents chronic stress-induced anxiety in rats: comparison with diazepam.

Anxiety is frequently observed in several neuropsychiatric disorders, and stress is thought to precipitate or exacerbate anxiety. In this study, the anxiolytic action of a herbal medicine, saikokaryukotsuboreito, (SRBT) was examined in normal healthy rats using the elevated plus-maze test. Moreover, the improving effect of SRBT on chronic stress-induced anxiety was also examined. Single administration of SRBT did not have anxiolytic action in normal rats. Repeated administration of SRBT significantly improved chronic stress-induced anxiety. On the other hand, single administration of a typical anxiolytic, diazepam, had anxiolytic action in normal rats but repeated administration did not improve chronic stress-induced anxiety. These results suggest that SRBT does not have anxiolytic activity equivalent to that of diazepam but has potency for improving stress-related anxiety. This finding provides information important for the treatment of anxiety.

Persistent depressive state after chronic stress in rats is accompanied by HPA axis dysregulation and reduced prefrontal dopaminergic neurotransmission.

Exposure to stress is thought to play an important role in the etiology of depression. Dysregulation of the hypothalamo-pituitary-adrenal (HPA) axis characterized by glucocorticoid negative feedback resistance is frequently observed in human depressives. Additionally, dysfunctions of the dopaminergic and serotonergic systems in the prefrontal cortex (PFC) are thought to be involved in the development of a depressive state. In rats, chronic stress induces a behaviorally depressive state, concomitant with dysregulation of the HPA axis and reductions in dopaminergic and serotonergic transmissions in the PFC. Considering that dysregulation of the HPA axis is associated with relapse and persistency of depression, it is possible that the chronic stress-induced depressive state persists during long-term rest after its exposure. In the present study, we examined this possibility in rats and found that the behaviorally depressive state in the rotarod test, negative feedback resistance in the dexamethasone suppression test, and a decrease in the extracellular concentration of dopamine but not serotonin in the PFC persisted for 3 months following a 4-week stress session. These results suggest that dysregulation of the HPA system and reduced dopaminergic transmission in the PFC underlies persistent behavioral depression following chronic stress.

Suppression of glucocorticoid secretion enhances cholinergic transmission in rat hippocampus.

We previously demonstrated that suppression of glucocorticoid secretion by adrenalectomy (ADX) impaired prefrontal cortex-sensitive working memory, but not reference memory. Since the cholinergic system in the hippocampus is also involved in these memories, we examined the effects of glucocorticoid suppression on cholinergic transmission in the rat hippocampus. A microdialysis study revealed that ADX did not affect the basal acetylcholine release, but enhanced the KCl-evoked response. This enhanced response was reversed by the corticosterone replacement treatment. The extracellular choline concentrations increased under both basal and KCl-stimulated conditions in the ADX rats, and these increases were also reversed by the corticosterone replacement. These results indicate that suppression of glucocorticoid secretion enhances cholinergic transmission in the hippocampus in response to stimuli. It is possible that this enhanced cholinergic transmission may not contribute to the ADX-induced working memory impairment, but it may be involved in maintenance of reference memory.

Suppression of glucocorticoid secretion induces a behaviorally depressive state in rotarod performance in rat.

Glucocorticoid hormones are important in the maintenance of many brain functions, and their receptors distribute abundantly throughout the brain. In patients with several neuropsychiatric disorders such as depression, dysregulation of the glucocorticoid negative feedback system is the consistent observations, which is thought to be caused by reduced glucocorticoid response at the several feedback sites including the brain. In the present study, we examined whether reduced glucocorticoid actions via suppression of circulating glucocorticoids by adrenalectomy (ADX) induced a behavioral depressive state using the rotarod test. We found that ADX impaired the rotarod performance while it did not affect the traction performance and locomotor activity. Moreover, this impairment was significantly reversed by corticosterone replacement treatment and was ameliorated by the infusion of D1 receptor agonist SKF 81297 into the prefrontal cortex (PFC) in a dose-dependent manner. Considering the previous findings that ADX reduces dopaminergic transmission in the PFC, the present results suggest that suppression of circulating glucocorticoids induces a behaviorally depressive state that is caused by a D1 receptor-mediated hypodopaminergic mechanism in the PFC. This finding would help to understand the involvement of the dysregulated feedback system in the pathogenesis of depression.

[A systematic review of working hours and mental health burden].

There is growing concern over the possible increase in mental health problems among Japanese workers. This trend is generally regarded as a reflection of Japan's prolonged economic depression and changes in working environment. In fact, claims for compensation for industrial accidents related to mental health diseases have been rapidly increasing in recent years. Working hours, personal-relationships, support from supervisors/co-workers, job demand, job control, and payment are known to affect workers mental health. In 2004, the Government announced a guideline to combat overwork and mental health problems at work places. This guideline articulates that long overtime working is a major indicator, and workers who work over 100 h overtime in a month should be encouraged to see an occupational physician. This guideline takes into account the practicalities of occupational health at work places and the empiric knowledge that long working hours might associate with workers mental health status. It may be reasonable to assume that long working hours affect workers health status both psychologically and physiologically, interacting with a variety of occupational factors, particularly job stress. However, the association between working hours and workers mental health status has not been fully clarified. The present article aimed to provide a systematic review of the association between working hours and mental health problems. The authors conducted a systematic review of the published literature on the association between working hours and mental health problems using PubMed. Of 131 abstracts and citations reviewed, 17 studies met the predefined criteria. Ten of these are longitudinal studies, and the others are cross-sectional studies. Seven of the 17 studies report statistically significant associations between working hours and mental health problems, while the others report no association. In addition, comparison among these studies is difficult because a variety of measurements of working hours were used. The present review found inconsistent results in the association between working hours and mental health burden.

[Long working hours and cardiovascular diseases: a systematic review].

Three years have passed since the countermeasures against the adverse health effects of overwork started in Japan, and fruitful outcomes have been expected. In the current study, a systematic review of articles was performed regarding the association of long working hours (LWH) with cardiovascular diseases (CVD) to obtain recent evidence of their association. An electronic database search was conducted using PubMed among English-written original articles published until December, 2004. A total of twelve articles were found conforming to the study's inclusion criteria, but evidence supporting the association of LWH and CVD was not detected. However, some distinctive studies related to the prevention of CVD were found relating to the concept of sensitive psychosocial factors such as vital exhaustion, and to the statistical modeling of occupational factors and biological indicators with the interaction term of psychosocial factors. Further studies will be needed to clarify the association of LWH and CVD.

Late S phase-specific recruitment of Mre11 complex triggers hierarchical assembly of telomere replication proteins in Saccharomyces cerevisiae.

In Saccharomyces cerevisiae, telomere replication occurs in late S phase and is accompanied by dynamic remodeling of its protein components. Here, we show that MRX (Mre11-Rad50-Xrs2), an evolutionarily conserved protein complex involved in DNA double-strand break (DSB) repair, is recruited to the telomeres in late S phase. MRX is required for the late S phase-specific recruitment of ATR-like kinase Mec1 to the telomeres. Mec1, in turn, contributes to the assembly of the telomerase regulators Cdc13 and Est1 at the telomere ends. Our results provide a model for the hierarchical assembly of telomere-replication proteins in late S phase; this involves triggering by the loading of MRX onto the chromosome termini. The recruitment of DNA repair-related proteins to the telomeres at particular times in the cell cycle suggests that the normal terminus of a chromosome is recognized as a DSB during the course of replication.

46,XY phenotypic male with focal segmental glomerulosclerosis caused by the WT1 splice site mutation.

OBJECTIVE: Frasier syndrome is characterized by progressive glomerulopathy due to nonspecific focal and segmental glomerulosclerosis (FSGS), 46,XY sex reversal and the development of gonadoblastoma from dysgenetic gonads. Donor splice site heterozygous mutations in intron 9 of the Wilms' tumor gene (WT1) cause this disease. We investigated whether WT1 mutations showed clinical heterogeneity. PATIENTS AND METHODS: A 6-year-old phenotypic boy was diagnosed as having FSGS. His karyotype was 46,XY. Gonadotropin-releasing hormone and human chorionic gonadotropin stimulation tests revealed normal luteinizing hormone, follicle-stimulating hormone and testosterone responses. The other patient was a 7-year-old 46,XY female with FSGS. Prophylactic gonadectomy was performed and gonadoblastoma was found. By polymerase chain reaction and direct sequencing, WT1 was analyzed in these patients. RESULTS AND CONCLUSION: Both patients had IVS9 + 5G-->A in intron 9 of the WT1. Our study indicates a normal 46,XY phenotypic male patient with FSGS. The phenotypic variations of the WT1 splice site mutations are further expanded.