Keiya Kojima

Time course of pain sensation in rat models of insulin resistance, type 2 diabetes, and exogenous hyperinsulinaemia

Small sensory fibre dysfunction has been recently recognized as a component of impaired glucose tolerance and insulin resistance (IR) syndrome. However, few studies have investigated whether small sensory fibre dysfunction develops in normoglycaemic or pre‐diabetic animal models of IR and/or hyperinsulinaemia. In addition, scant information is available on the metabolic features of IR in relation to small sensory fibre dysfunction due to the progressive failure of beta cells to compensate for IR during the development of frank diabetes.

The Asian project for collaborative derivation of reference intervals: (2) results of non-standardized analytes and transference of reference intervals to the participating laboratories on the basis of cross-comparison of test results

Abstract Background: The 2009 Asian multicenter study for derivation of reference intervals (RIs) featured: 1) centralized measurements to exclude reagent-dependent variations; 2) inclusion of non-standardized analytes (hormones, tumor makers, etc.) in the target; and 3) cross-check of test results between the central and local laboratories. Transferability of centrally derived RIs for non-standardized analytes based on the cross-check was examined. Methods: Forty non-standardized analytes were centrally measured in sera from 3541 reference individuals recruited by 63 laboratories. Forty-four laboratories collaborated in the cross-check study by locally measuring aliquots of sera from 9 to 73 volunteers (average 22.2). Linear relationships were obtained by the major-axis regression. Error in converting RIs using the regression line was expressed by the coefficient of variation of slope b [CV(b)]. CV(b) <10% was set as the cut-off value allowing the conversion. The significance of factors for partitioning RIs was determined similarly as in the first report. Results: Significant sex-, age-, and region-related changes in test results were observed in 17, 15, and 11 of the 40 analytes, respectively. In the cross-comparison study, test results were not harmonized in the majority of immunologically measured analytes, but their average CV(b)s were <10% except for total protein, cystatin C, CA19-9, free thyroxine, and triiodothyronine. After conversion, 74% of centrally derived RIs were transferred to each local laboratory. Conclusions: Our results point to the feasibility of: 1) harmonizing test results across different laboratories; and 2) sharing centrally derived RIs of non-standardized analytes by means of comparative measurement of a set of commutable specimens.

Flow Cytometric Analysis of Red Blood Cell Osmotic Fragility

This study investigated a new method of flow cytometry (FCM) for analysis of red blood cell (RBC) osmotic fragility. Venous peripheral blood collected in a sampling tube coated with EDTA 2Na was analyzed using FCM to determine RBC osmotic fragility. RBCs were represented as a double-peaked forward scatter (FSC) histogram in FCM. RBCs showed ballooning and spherical shape change in hypotonic solutions before hemolysis. The ballooning of RBCs was expressed as a disappearance of the minor peak and by narrowing and a shift to the right of the FSC histogram. The process of hemolysis was expressed as shrinking of the RBC cytogram in the right upper quadrant on the scatter plot of side scatter versus FSC and by emergence of a cell debris cytogram in the left lower quadrant. The ratio of intact RBCs in hypotonic solution was available as an indicator of osmotic fragility. Acidic solution made erythrocytes less tolerant to hypotonic solution by inducing spherical shape change. In conclusion, FCM can be used to assess RBC osmotic fragility.

Olmesartan ameliorates peripheral nerve dysfunction in Zucker diabetic fatty rats.

Objective Angiotensin (ANG) II type 1 receptor (AT1R) blockers have neuroprotective effects against neuronal lesions. The present study examines whether the AT1R blocker olmesartan improves peripheral nerve dysfunction in rats with type 2 diabetes. Methods Fourteen-week-old male type 2 diabetic Zucker diabetic fatty (ZDF) rats were orally administered with olmesartan (6 mg/kg per day; n = 7) or not treated (n = 7) and then followed up for nine weeks. Age-matched and sex-matched nondiabetic lean rats served as controls (n = 7). Results Olmesartan for 9 weeks did not influence blood glucose and A1c levels that were higher in untreated ZDF (U-ZDF) rats than in control rats. In U-ZDF rats, myelinated fiber density and myelin areas of myelinated fibers in peroneal nerves significantly increased and decreased, respectively, and the intraepidermal nerve fiber density (IENFD) of footpad skin tended to decrease. The U-ZDF rats developed mechanical hyperalgesia, thermal hypoalgesia and slower sensory and motor nerve conduction in the sciatic–tibial nerves. Olmesartan increased myelin areas and IENFD and ameliorated sensory nerve conduction deficits. These beneficial effects of olmesartan were associated with ANG II and insulin receptor upregulation in sensory neurons as well as deactivation of Erk1/2 in sciatic nerves. Conclusion Olmesartan appears to improve the structure and function of small and large nerves and upregulate ANG II and insulin receptors in sensory neurons of rats with type 2 diabetes.

Possible involvement of reusable towels in the high rate of Bacillus species-positive blood cultures in Japanese hospitals.

BACKGROUND A number of outbreaks caused by Bacillus species have been reported to date. Outbreaks reported in the last decade have predominantly arisen in Japanese hospitals. AIM To elucidate factors contributing to these real or pseudo outbreaks by Bacillus species, and to evaluate the rate of Bacillus species-positive blood culture samples in Japan. METHODS A systematic review of the literature was performed. Reports including data on outbreaks caused by Bacillus species were searched for in PubMed, Google Scholar and Evidence-based Medicine BMJ from inception through 10 Aug 2014. Japanese nationwide data on bacteriological tests were collected from Japan Nosocomial Infections Surveillance. Regional bacteriological data for Akita prefecture were collected using the Akita Regional Network for Infection Monitoring/Control System. FINDINGS Contamination of reusable towels was suspected as a cause for the high rate of Bacillus-positive blood cultures in Japan. The rate of Bacillus species in blood cultures was much higher in Japan than in reports from other countries. CONCLUSIONS The high contamination rate of blood culture samples by Bacillus species in Japan is a matter of concern for infection control and medical treatment. Bacteriological investigation of reusable towels should be considered in hospitals with a high frequency of Bacillus-positive blood cultures.

Spurious Thrombocytosis Caused by Tumor Cell Lysis in a Patient with Acute Monocytic Leukemia

BACKGROUND Tumor lysis syndrome can occur after treatment of fast-growing cancers. Early detection of tumor lysis is crucial to minimize the toxic effects on organs and potentially life-threatening complications. METHODS A patient with acute monocytic leukemia presented with spurious thrombocytosis. A peripheral blood smear was stained with alpha-naphthyl butyrate esterase to discriminate tumor cell fragments from platelets. RESULTS Peripheral blood smears showed widespread leukemic cell fragmentation. Tumor lysis syndrome (TLS) after treatment for acute monocytic leukemia was diagnosed. The patient underwent chemo- and radiotherapy followed by umbilical cord blood transplantation and remains symptom-free two years after transplantation. CONCLUSIONS For patients with thrombocytosis accompanied by bizarre scatter-grams on automatic hematologic analyzers, further diagnostic procedures should be performed to determine the exact cause of thrombocytosis.

An Angled Stick Colonic Irrigation Device for the Bowel ManagementPrograms in Patients with Impaired Bowel Function

Objective: Retrograde colonic irrigation is a treatment of choice for severe defecation disorders accompanied by congenital disorders such as anal malformations and spina bifida; however, it requires skills, effort and enough space. With the aim of making retrograde colonic irrigation easier and comfortable, we made a self-help colonic irrigation device applicable for these patients. Methods: An angled stick colonic irrigation device was made for comfortable retrograde colonic irrigation. Angulated handle colonic irrigation system was trialled by seven preschool and school age patients including four patients with spina bifida and three patients with congenital ano-rectal anomaly. Results: Four out of seven patients operated the angulated handle colonic irrigator well. The colonic irrigation device enabled the patients with severe defecation disorders to hold the cone tip securely in place and prevented backflow and contamination. Conclusion: The angulated handle colonic irrigator may help retrograde colonic irrigation more comfortable and easier in selected patients with spina bifida or ano-rectal malformations.