Usefulness of the one-step technique in functional end-to-end anastomosis for colonic surgery: results of a prospective multicentre cohort study from the Japanese KYCC group.

BACKGROUND: Although functional end-to-end anastomosis (FEEA) using a stapler in the colorectal field has been recognised worldwide, the technique varies by surgeon, and the safety of anastomosis using different techniques is unknown. METHODS: This multicentre prospective observational cohort study was conducted by the KYCC Study Group in Yokohama, Japan, and included patients who underwent colonic resection at seven centres between April 2020 and March 2022. This study compared the incidence of surgery-related abdominal complications (SAC: anastomotic leakage [AL], anastomotic bleeding, intra-abdominal abscess, enteritis, ileus, surgical site infection, and other abdominal complications) between two different methods of FEEA (one-step [OS] method: simultaneous anastomosis and bowel resection; two-step [TS] method: anastomosis after bowel resection). Complications of Clavien-Dindo classification grade 2 or higher were assessed. RESULTS: Among 293 eligible cases, the OS and TS methods were used in 194 (66.2%) and 99 (33.8%) patients, respectively. The baseline characteristics were similar between the groups. The OS method used fewer staplers (three vs. four staplers, p < 0.00001). There were no significant differences in SAC rate between the OS (19.1%) and the TS (16.2%) groups (p = 0.44). The OS group had four cases (2.1%) of AL (two patients; grade 3, two patients; grade 2) while the TS group had one case (1.0%) of grade 2 AL (p = 0.67). Multivariate logistic regression analysis showed that male sex (odds ratio [OR] 3.95; p < 0.00001), an open surgical approach (OR 2.36; p = 0.03), and longer operative duration (OR,2.79; p = 0.002) were independent predictors of complications, whereas the OS method was not an independent predictor (OR 1.17; p = 0.66). CONCLUSIONS: The OS and the TS technique for stapled colonic anastomosis in a FEEA had a similar postoperative complication rate. TRIAL REGISTRATION NUMBER: UMIN000039902 (registration date 23 March 2020).

Quantification of inter-brain coupling: A review of current methods used in haemodynamic and electrophysiological hyperscanning studies.

Hyperscanning is a form of neuroimaging experiment where the brains of two or more participants are imaged simultaneously whilst they interact. Within the domain of social neuroscience, hyperscanning is increasingly used to measure inter-brain coupling (IBC) and explore how brain responses change in tandem during social interaction. In addition to cognitive research, some have suggested that quantification of the interplay between interacting participants can be used as a biomarker for a variety of cognitive mechanisms aswell as to investigate mental health and developmental conditions including schizophrenia, social anxiety and autism. However, many different methods have been used to quantify brain coupling and this can lead to questions about comparability across studies and reduce research reproducibility. Here, we review methods for quantifying IBC, and suggest some ways moving forward. Following the PRISMA guidelines, we reviewed 215 hyperscanning studies, across four different brain imaging modalities: functional near-infrared spectroscopy (fNIRS), functional magnetic resonance (fMRI), electroencephalography (EEG) and magnetoencephalography (MEG). Overall, the review identified a total of 27 different methods used to compute IBC. The most common hyperscanning modality is fNIRS, used by 119 studies, 89 of which adopted wavelet coherence. Based on the results of this literature survey, we first report summary statistics of the hyperscanning field, followed by a brief overview of each signal that is obtained from each neuroimaging modality used in hyperscanning. We then discuss the rationale, assumptions and suitability of each method to different modalities which can be used to investigate IBC. Finally, we discuss issues surrounding the interpretation of each method.

Clinical characteristics and outcomes of pheochromocytoma crisis: a literature review of 200 cases.

PURPOSE: Pheochromocytoma crisis is a life-threatening endocrine emergency that requires prompt diagnosis and treatment. Because of its rarity, sudden onset, and lack of internationally uniform and validated diagnostic criteria, pheochromocytoma crisis remains to be fully clarified. Therefore, we aimed to describe the clinical characteristics and outcomes of pheochromocytoma crisis through a literature review. METHODS: We performed a systematic literature search of PubMed/MEDLINE database, Igaku-Chuo-Zasshi (Japanese database), and Google Scholar to identify case reports of pheochromocytoma crisis published until February 5, 2021. Information was extracted and analyzed from the literature that reported adequate individual patient data of pheochromocytoma crisis in English or Japanese. Cases were also termed as pheochromocytoma multisystem crisis (PMC) if patients had signs of hyperthermia, multiple organ failure, encephalopathy, and labile blood pressure. RESULTS: In the 200 cases of pheochromocytoma crisis identified from 187 articles, the mean patient age was 43.8 ± 15.5 years. The most common symptom was headache (39.5%). The heart was the most commonly damaged organ resulting from a complication of a pheochromocytoma crisis (99.0%), followed by the lungs (44.0%) and the kidney (21.5%). PMC accounted for 19.0% of all pheochromocytoma crisis cases. After excluding 12 cases with unknown survival statuses, the mortality rate was 13.8% (26/188 cases). Multivariable logistic regression analysis revealed that nausea and vomiting were significantly associated with a higher mortality rate. CONCLUSION: Pheochromocytoma can present with different symptomatology, affecting different organ systems. Clinicians should be aware that patients with nausea or vomiting are at a higher risk of death because of pheochromocytoma crisis.

Learning Promotes Subfield-Specific Synaptic Diversity in Hippocampal CA1 Neurons.

The hippocampus is functionally heterogeneous between the dorsal and ventral subfields with left-right asymmetry. To determine the possible location of contextual memory, we performed an inhibitory avoidance task to analyze synaptic plasticity using slice patch-clamp technique. The training bilaterally increased the AMPA/NMDA ratio at dorsal CA3-CA1 synapses, whereas the training did not affect the ratio at ventral CA3-CA1 synapses regardless of the hemisphere. Moreover, sequential recording of miniature excitatory postsynaptic currents and miniature inhibitory postsynaptic currents from the same CA1 neuron clearly showed learning-induced synaptic plasticity. In dorsal CA1 neurons, the training dramatically strengthened both excitatory and inhibitory postsynaptic responses in both hemispheres, whereas the training did not promote the plasticity in either hemisphere in ventral CA1 neurons. Nonstationary fluctuation analysis further revealed that the training bilaterally increased the number of AMPA or GABAA receptor channels at dorsal CA1 synapses, but not at ventral CA1 synapses, suggesting functional heterogeneity of learning-induced receptor mobility. Finally, the performance clearly impaired by the bilateral microinjection of plasticity blockers in dorsal, but not ventral CA1 subfields, suggesting a crucial role for contextual learning. The quantification of synaptic diversity in specified CA1 subfields may help us to diagnose and evaluate cognitive disorders at the information level.

Air test as a simple method of screening for Hirschsprung's disease.

AIM: To present the technique and the diagnostic accuracy of the air test to diagnose Hirschsprung's disease (HD). MATERIALS AND METHODS: Children who attended hospital for chronic constipation (CC) between January 2012 and December 2016 for whom the air test was performed were enrolled. The test was conducted during contrast enema under fluoroscopic observation using 20-50 ml injections of air into the rectum through a 10 F Nelaton catheter. The demographics, results of the air test, and additional examinations, as well as the outcomes of subsequent treatments were analysed retrospectively. RESULTS: The air test was conducted in 179 patients (median: 3 years, range: 0-14 years), and was positive in 150 and negative in 29 cases. Of the 29 patients with negative results, four were diagnosed with HD by rectal suction biopsy (RSB). Of the remaining 25 patients, RSB was conducted in seven and HD was excluded in all cases. In all 150 patients with positive air test results, CC was adequately controlled with conservative treatment. The sensitivity and specificity of the air test were 100% (4/4) and 85.7% (150/175), respectively. CONCLUSIONS: The air test can be used as a new non-invasive screening method for HD, performed simultaneously with contrast enema.

Comparison of insulin degludec with insulin detemir in type 1 diabetes: a 1-year treat-to-target trial.

The long-term safety and tolerability of insulin degludec (IDeg) was compared with that of insulin detemir (IDet), as basal treatment in participants with type 1 diabetes mellitus (T1DM). In the present multinational, 26-week core + 26-week extension, controlled, open-label, parallel-group trial, adults with T1DM were randomized to IDeg or IDet as basal insulin treatment combined with meal-time bolus insulin aspart. IDeg was administered once daily, whilst IDet was administered once or twice daily depending on patients' glycaemic control. After 1 year, IDeg provided a 33% lower rate of nocturnal hypoglycaemia compared with IDet: estimated rate ratio (IDeg : IDet) 0.67 [95% confidence interval (CI) 0.51; 0.88]; p < 0.05. IDeg improved glycated haemoglobin after 1 year of treatment, similarly to IDet, but IDeg also provided a significantly greater reduction in fasting plasma glucose compared with IDet: estimated difference (IDeg - IDet) -1.11 (95% CI -1.83; -0.40) mmol/l; p < 0.05. The present study confirmed the long-term safety and tolerability profile of IDeg in patients with T1DM. IDeg provided a lower risk of nocturnal confirmed hypoglycaemia than IDet.

Gli2 protein expression level is a feasible marker of ligand-dependent hedgehog activation in pancreatic neoplasms.

The hedgehog pathway is known to promote proliferation of pancreatic ductal adenocarcinoma (PDA) and has been shown to restrain tumor progression. To understand how hedgehog causes these effects, we sought to carefully examine protein expression of hedgehog signaling components during different tumor stages. Genetically engineered mice, Pdx1-Cre;LSL-KrasG12D and Pdx1-Cre;LSL-KrasG12D;p53lox/+, were utilized to model distinct phases of tumorigenesis, pancreatic intraepithelial neoplasm (PanIN) and PDA. Human pancreatic specimens of intraductal papillary mucinous neoplasm (IPMN) and PDA were also employed. PanIN and IPMN lesions highly express Sonic Hedgehog, at a level that is slightly higher than that observed in PDA. GLI2 protein is also expressed in both PanIN/IPMN and PDA. Although there was no difference in the nuclear staining, the cytoplasmic GLI2 level in PDA was modest in comparison to that in PanIN/IPMN. Hedgehog interacting protein was strongly expressed in the precursors, whereas the level in PDA was significantly attenuated. There were no differences in expression of Patched1 at early and late stages. Finally, a strong correlation between Sonic Hedgehog and GLI2 staining was found in both human and murine pancreatic tumors. The results indicate that the GLI2 protein level could serve as a feasible marker of ligand-dependent hedgehog activation in pancreatic neoplasms.

Sinistral portal hypertension after pancreaticoduodenectomy with splenic vein ligation.

BACKGROUND: Splenic vein ligation may result in sinistral (left-sided) portal hypertension and gastrointestinal haemorrhage. The aim of this study was to analyse the pathogenesis of sinistral portal hypertension following splenic vein ligation in pancreaticoduodenectomy. METHODS: Patients who underwent pancreaticoduodenectomy for pancreatic cancer between January 2005 and December 2012 were included in this retrospective study. The venous flow pattern from the spleen and splenic hypertrophy were examined after surgery. RESULTS: Of 103 patients who underwent pancreaticoduodenectomy with portal vein resection, 43 had splenic vein ligation. There were two predominant venous flow patterns from the spleen. In the varicose route (27 patients), flow from the spleen passed to colonic varices and/or other varicose veins. In the non-varicose route, flow from the spleen passed through a splenocolonic collateral (14 patients) or a spontaneous splenorenal shunt (2 patients). The varicose route was associated with significantly greater splenic hypertrophy than the non-varicose route (median splenic hypertrophy ratio 1·52 versus 0·94; P < 0·001). All patients with the varicose route had colonic varices, and none had a right colic marginal vein at the hepatic flexure. CONCLUSION: Pancreaticoduodenectomy with splenic vein ligation may lead to sinistral portal hypertension. To avoid the development of varices, it is important to preserve the right colic marginal vein. Reconstruction of the splenic vein should be considered if the right colic marginal vein is divided.

Electron and Ion Heating Characteristics during Magnetic Reconnection in the MAST Spherical Tokamak.

Electron and ion heating characteristics during merging reconnection start-up on the MAST spherical tokamak have been revealed in detail using a 130 channel yttrium aluminum garnet (YAG) and a 300 channel Ruby-Thomson scattering system and a new 32 chord ion Doppler tomography diagnostic. Detailed 2D profile measurements of electron and ion temperature together with electron density have been achieved for the first time and it is found that electron temperature forms a highly localized hot spot at the X point and ion temperature globally increases downstream. For the push merging experiment when the guide field is more than 3 times the reconnecting field, a thick layer of a closed flux surface form by the reconnected field sustains the temperature profile for longer than the electron and ion energy relaxation time ~4-10 ms, both characteristic profiles finally forming a triple peak structure at the X point and downstream. An increase in the toroidal guide field results in a more peaked electron temperature profile at the X point, and also produces higher ion temperatures at this point, but the ion temperature profile in the downstream region is unaffected.

Cost-Effectiveness Analysis of the Diagnosis and Treatment of Primary Aldosteronism in Japan.

Approximately 10% of cases of hypertension in Japan are caused by primary aldosteronism (PA), amounting to about 4 million patients in total. Primary aldosteronism due to unilateral aldosterone hypersecretion is potentially curable by adrenalectomy. The clinical benefits of identifying and treating PA have been reported internationally, but its cost-effectiveness is unclear. We examined whether diagnosing and treating hidden PA in hypertensive population was cost-effective compared with suboptimal treatment. Our hypothetical patient was a 50-year-old man diagnosed with stage I-III hypertension. We established a Markov decision model based on plausible clinical pathways and prognoses of PA. We applied cost-effectiveness analysis comparing a comprehensive diagnostic strategy for PA (measurement of plasma aldosterone/renin ratio, 2 loading tests, imaging, and selective adrenal venous sampling) with a suboptimal strategy to manage hypertension by medication unless the typical signs of PA or other complication were manifest. Outcome measures were expected costs, expected effectiveness, and incremental cost-effectiveness ratio. The robustness of the findings was established by one-way and scenario sensitivity analyses. The comprehensive PA diagnostic strategy increased the expected costs by 64 004 JPY and expected life-years by 0.013 compared with standard treatment. The incremental cost-effectiveness ratio for the diagnosis of PA was 4 923 385 JPY per year. Our findings were sensitive to the outcomes of screening and treatment, and the costs of continuous or periodic medication for hypertension and the treatment of stroke and its complications.

Characterization of Spontaneous Mammary Tumors in Domestic Djungarian Hamsters (Phodopus sungorus).

Mammary tumors that spontaneously occurred in domestic Djungarian hamsters (Phodopus sungorus) were histologically examined. Forty-five mammary tumors included 14 adenomas, 18 adenocarcinomas, 1 lipid-rich carcinoma, 2 adenoacanthomas, 2 malignant adenomyoepitheliomas, 1 benign mixed tumor, and 7 "balloon cell" carcinosarcomas. The latter 4 types were newly recognized neoplasms in Djungarian hamsters. The relatively high incidence of spontaneous mammary carcinosarcomas in domestic Djungarian hamsters is intriguing. Carcinosarcomas exhibited anomalous histological features made up of a mixture of glandular cells, polygonal cells (including "balloon cells"), and sarcomatous spindle cells in varying proportions. Transitional features from glandular cells to polygonal cells and subsequently to sarcomatous spindle cells were observed. Using immunohistochemistry, we observed that glandular cells exhibited an epithelial phenotype (cytokeratin(+)/vimentin(-)), spindle cells exhibited a mesenchymal phenotype (cytokeratin(-)/vimentin(+)), and polygonal cells exhibited an intermediate phenotype (cytokeratin(+)/vimentin(+)). Reduction or loss of ß-catenin expression and gain of S100A4 expression were observed in polygonal and spindle cells. The polygonal cell population included a varying number of characteristic cells that were expanded by large intracytoplasmic vacuoles. Electron microscopy revealed that these "balloon cells" had large cytoplasmic lumens lined by microvilli. These observations suggest that epithelial-mesenchymal transition may account for the pathogenesis of mammary carcinosarcomas in Djungarian hamsters.

Improvement of skin condition by oral supplementation with sphingomyelin-containing milk phospholipids in a double-blind, placebo-controlled, randomized trial.

Sphingomyelin (SM), an essential phospholipid for the skin, is contained largely in the milk fat globule membrane surrounding milk fat, concentrated fractions of which are also generated concurrently during the manufacture of dairy products. Such an SM-containing milk phospholipid concentrate (SM-MPC) is useful for investigating the benefits of dietary SM. Here, we examined the effect of consuming SM-MPC on the condition of skin in a double-blind, placebo-controlled, randomized trial. Ninety-six healthy subjects aged 20 to 39 yr with low skin hydration were randomly assigned to 3 groups: a high-SM group supplemented with SM-MPC at a dose equivalent to 10 mg/d of SM, a low-SM group supplemented with SM-MPC equivalent to 5 mg/d of SM, and a placebo group fed a vehicle composed of olive oil and beeswax. During daily supplementation for 12 wk, parameters related to the condition of skin were evaluated at baseline and every 3 wk. Skin hydration at the heel was significantly increased at wk 9 and 12 in the low-SM group compared with the placebo group. Skin elasticity in the region below the eye was significantly increased at wk 9 in the high-SM group versus placebo. Questionnaire-based subjective perceptions of skin conditions were significantly improved for facial skin moisture at wk 3 and 12, and in the wrinkle around the eyes at wk 9 and 12 in the high-SM group versus placebo. Our results indicate that constant and long-term supplementation with SM-MPC is capable of improving the general condition of skin.

Efficacy and safety of insulin degludec given as part of basal-bolus treatment with mealtime insulin aspart in type 1 diabetes: a 26-week randomized, open-label, treat-to-target non-inferiority trial.

AIMS: The efficacy and safety of insulin degludec (IDeg) was compared with insulin detemir (IDet), both administered once daily (OD) as basal treatment in participants with type 1 diabetes mellitus (T1DM). The primary outcome was non-inferiority of IDeg to IDet in glycated haemoglobin (HbA1c) reduction after 26 weeks. METHODS: This multinational, 26-week, controlled, open-label, parallel-group trial randomized adults with T1DM to IDeg or IDet as OD basal insulin treatment combined with mealtime bolus insulin aspart (IAsp). Participants with T1DM treated with any basal-bolus insulin regimen for ≥ 12 months prior to the trial, a mean HbA1c ≤ 10.0% (85.8 mmol/mol) and body mass index (BMI) ≤ 35.0 kg/m(2) at screening participated in the trial (IDeg: N = 302; IDet: N = 153). RESULTS: After 26 weeks, HbA1c decreased 0.73% (8.0 mmol/mol) (IDeg) and 0.65% (7.1 mmol/mol) (IDet) [estimated treatment difference (ETD) IDeg-IDet: -0.09% (-0.23; 0.05)95% CI (-10.0 mmol/mol [-2.6; 0.6]95% CI ); confirming non-inferiority]. Mean fasting plasma glucose improved in both groups, and was lower with IDeg than IDet [ETD IDeg-IDet: -1.66 mmol/l (-2.37; -0.95)95% CI , p < 0.0001]. The rate of confirmed hypoglycaemia was similar with IDeg and IDet [45.83 vs. 45.69 episodes per patient-year of exposure (PYE); estimated rate ratio (RR) IDeg/IDet: 0.98 (0.80; 1.20)95% CI , p = 0.86]. The rate of nocturnal confirmed hypoglycaemia was lower with IDeg than IDet [4.14 vs. 5.93 episodes per PYE; RR IDeg/IDet: 0.66 (0.49; 0.88)95% CI , p = 0.0049]. Adverse event profiles were similar between groups. CONCLUSION: IDeg administered OD in basal-bolus therapy effectively improved long-term glycaemic control in participants with T1DM with a lower risk of nocturnal confirmed hypoglycaemia than IDet.

Evaluation of the non-functional tooth contact in patients with temporomandibular disorders by using newly developed electronic system.

The aims of this study were to introduce a novel electronic system for reliable evaluation of the non-functional tooth contact in patients with temporomandibular disorders (TMDs) and investigate the possible associations between the non-functional tooth contact and some characteristics of the patients with TMD. We designed and installed a software program to send emails regarding the non-functional tooth contact to the subjects' preregistered cellular phones at intervals of 20 ± 9 min daily for 10 consecutive days. Twelve patients with TMD and 12 gender- and age-matched healthy subjects responded via emails to one of 3 choices: no tooth contact, tooth contact during oral functions or tooth contact not associated with oral functions. The influence of subjective stress, anxiety, depression, personality and daily activities on tooth contact was then assessed. The frequency of the non-functional tooth contact was significantly higher in the patients with TMD than in the healthy subjects (35·0% vs. 9·6%, P < 0·001), while no significant group difference was found for the frequency of functional tooth contact, the stress, anxiety, depression and personality.

Limit on neutrinoless ßß decay of 136Xe from the first phase of KamLAND-Zen and comparison with the positive claim in 76Ge.

We present results from the first phase of the KamLAND-Zen double-beta decay experiment, corresponding to an exposure of 89.5 kg yr of (136)Xe. We obtain a lower limit for the neutrinoless double-beta decay half-life of T(1/2)(0ν)>1.9×10(25) yr at 90% C.L. The combined results from KamLAND-Zen and EXO-200 give T(1/2)(0ν)>3.4×10(25) yr at 90% C.L., which corresponds to a Majorana neutrino mass limit of <(120-250) meV based on a representative range of available matrix element calculations. Using those calculations, this result excludes the Majorana neutrino mass range expected from the neutrinoless double-beta decay detection claim in (76)Ge, reported by a part of the Heidelberg-Moscow Collaboration, at more than 97.5% C.L.

Superior glycaemic control with once-daily insulin degludec/insulin aspart versus insulin glargine in Japanese adults with type 2 diabetes inadequately controlled with oral drugs: a randomized, controlled phase 3 trial.

AIMS: This phase 3, 26-week, open-label, treat-to-target trial investigated the efficacy and safety of insulin degludec/insulin aspart (IDegAsp) in insulin-naïve Japanese adults with type 2 diabetes. METHODS: Subjects were randomized to once-daily injections of IDegAsp (n = 147) or insulin glargine (IGlar) (n = 149), both ±≤2 oral antidiabetic treatments. IDegAsp was given before the largest meal at the discretion of each subject (and maintained throughout the trial); IGlar was dosed according to label. Both insulins were titrated to a target prebreakfast self-measured plasma glucose of 3.9 to <5.0 mmol/l. RESULTS: After 26 weeks, mean HbA1c was 7% with IDegAsp and 7.3% with IGlar; superiority of IDegAsp to IGlar was shown (estimated treatment difference, ETD; IDegAsp-IGlar: -0.28% points [-0.46; -0.10](95% CI), p < 0.01). At end-of-trial, mean fasting plasma glucose (FPG) was similar for IDegAsp and IGlar (5.7 vs. 5.6 mmol/l; ETD IDegAsp-IGlar: 0.15 mmol/l [-0.29; 0.60](95% CI), p = NS). IDegAsp was associated with numerically lower rates of overall confirmed (27%) and nocturnal confirmed hypoglycaemia (25%) versus IGlar (estimated rate ratio IDegAsp/IGlar: 0.73 [0.50; 1.08](95% CI), p = NS, and 0.75 [0.34; 1.64](95% CI), p = NS, respectively). Mean daily insulin doses were similar between groups at end-of-trial (both: 0.41 U/kg) as were the increases in body weight from baseline (both: 0.7 kg). Adverse event profiles were similar between groups. CONCLUSIONS: IDegAsp provided superior long-term glycaemic control compared to IGlar, with similar FPG and doses and numerically lower rates of overall and nocturnal hypoglycaemia (p = NS).

Analysis of a questionnaire on adverse reactions to blood donation in Japan.

In 2007, the Japanese Red Cross Blood Center performed a large-scale questionnaire study of post-donation adverse reactions. The questionnaire was distributed to 98,389 donors, and the answers were returned by 55,231 (56.1%). In total, 2,877 (5.2%) complained of an adverse reaction. Assuming that there were no adverse reactions for the 46,150 donors who did not reply, the rate of adverse reaction can be speculated to be 2.8%. Our study strongly suggests that blood centers have long underestimated the risks of vaso-vagal reactions. Taking at least 6h of careful rest after donation would be a helpful counter measure.

Donor-based single electron pumps with tunable donor binding energy.

We report on single electron pumping via a tunable number of individual donors. We use a device that essentially consists of a silicon nanowire with local arsenic implantation between a set of fine gates. A temperature-dependent characterization of the pumped current allows us to extract the ionization energy of a single arsenic donor. We observe the ionization energy to be tunable by the gate electric field over a large range of energies.

The relationship between suicide and five climate issues in a large-scale and long-term study in Japan.

OBJECTIVE: Suicide rates in Japan were high in 1998 and have remained high since then. Many researchers have discussed the current state of suicide in Japan and the world; however, there are various opinions about the relationship between suicide and climate. SUBJECTS AND METHOD: In the present study, we report on long-term data of suicide and examine five climatic issues in Japan as a whole and in 10 selected prefectures: the five with the highest suicide rates in 2006 (Akita, Iwate, Shimane, Yamagata and Miyazaki Prefectures) and the five with the lowest (Nara, Tokushima, Okayama, Kanagawa and Kyoto Prefectures). RESULTS: Annual age-adjusted suicide rates were found to have a significant inverse correlation with annual mean air temperature in the five prefectures with the highest suicide rates and in the three prefectures with the lowest suicide rates among women. Annual age-adjusted suicide rates were significantly correlated with annual mean relative humidity in the three prefectures with the highest suicide rates among women and with the annual total sunshine duration in the three prefectures with the highest suicide rates among women. CONCLUSION: It is important that these associations between suicide and climatic factors be discussed further from various viewpoints, including those of many researchers and relevant organizations.