[Evaluation of the latex turbidimetric immunoassay for CK-MB protein]

CK-MB protein is an important marker for the diagnosis of acute coronary syndromes. In the present study, we evaluated the basal performance of recently developed CK-MB mass kit "L-type wako CK-MB mass". Within-run and between-day precision were obtained with 1.4-4.7% and 2.7-5.2%, respectively. Diluted linearity and lower limit of detection were obtained with 180.0 ng/mL and 2.1 ng/mL, respectively. Zone phenomenon was able to detect until 25,600.0 ng/mL. Analysis of interferent showed that only CK-BB positively influenced the assay results. CK-MB protein levels decreased to 82% at 72 hours in the room temperature, but it was stable at 4 degrees C and -20 degrees C. The correlation coefficient(r) between this assay and conventional assay was 0.999. However, discrepancy of the two cases was observed in the comparison between the two methods. In the case 1, CK isoenzyme analysis using electrophoresis indicated that CK-MB was not present and absorption test showed a 68% absorption effect of CK-MB protein values not by anti human IgG, anti human IgA, and animal serums, but anti human IgM. In the case 2, CK isoenzyme analysis indicated that there is not only CK-MB but CK-BB. CK-MB protein values between the two methods were fitted after decreasing CK-BB. Thus, Value discrepancy for CK-MB protein was resulting from IgM and CK-BB. We have to pay attention to such phenomenon when detecting an unlikely higher levels that could not be explained by clinical information.

Development of insulin allergy after bone marrow transplantation

BACKGROUND

Insulin allergy is a not uncommon condition even though human insulin and insulin analogues are widely used. However, the development of insulin allergy after bone marrow transplantation has not been reported.

CASE REPORT

A 44-year-old Japanese woman had aplastic anaemia and secondary haemochromatosis. She was diagnosed with having diabetes at age 32 years and had been treated with human insulin. At age 34 years, bone marrow transplantation was performed. One year later, a rash and urticaria appeared immediately after insulin injections. Intracutaneous tests were positive for both human insulins and analogues, whereas the test for protamine was negative. Furthermore, an IgE-radioallergosorbent test against insulin was positive. Thus, we diagnosed the patient with having an IgE-mediated type I allergy against insulin. Insulin therapy with insulin aspart, which showed the least skin reaction, was continued and the insulin allergy disappeared in 7 years.

CONCLUSIONS

This is the first description of insulin allergy after bone marrow transplantation. Our case underscores the effects of bone marrow cells on IgE-mediated type I allergy for insulin.

Local structure of LiCoO2 nanoparticles studied by Co K-edge x-ray absorption spectroscopy

We have studied the local structure of LiCoO(2) nanoparticles by Co K-edge x-ray absorption spectroscopy as a function of particle size. Extended x-ray absorption fine structure data reveal substantial changes in the near neighbor distances and the associated mean square relative displacements with decreasing particle size. X-ray absorption near edge structure spectra show clear local geometrical changes with decreasing particle size, similar to those that appear in the charging (delithiation) process. The results suggest that the LiCoO(2) nanoparticles are characterized by a large atomic disorder confined to the Co-O octahedra, similar to the distortions generated during the delithiation, and this disorder should be the primary limiting factor for a reversible diffusion of Li ions when nanoparticles of LiCoO(2) are used as cathode material in rechargeable Li ion batteries.

Enhancive effects of D-glucose and its analogs on expression of d-glucose-unrelated transgenes in mammalian cells

We studied the effects of d-glucose on transgene expression in mammalian cells by a reporter gene assay using CV-1 cells and a CMV promoter-controlled EGFP gene. Treatment of CV-1 cells with 5% D-glucose unchanged the number of fluorescent cells in fluorescence microscopic observation but significantly intensified fluorescence in the fluorometric assay. Furthermore, EGFP itself and mRNA became more abundant in Western blot and quantitative RT-PCR analyses of 5% D-glucose-treated cells, respectively. These results indicate that elevated D-glucose can activate transgene expression via transcriptional stimulation, at least in part. The same concentrations of L-glucose led to only negligible increases in transgene expression, indicating that D-glucose's effect is different from its osmotic effect. The D-glucose-induced augmentation of fluorescence was observed not only in the experiment using the CMV promoter-controlled EGFP gene but also in experiments using the SV40 and RSV promoter-controlled ones, suggesting that elevated D-glucose can enhance transgene expression regulated by various promoters commonly used in transgene expression. The assessment of D-glucose analogs for their enhancive effects on transgene expression revealed that 1,6-anhydro-D-glucose and β-methyl-D-glucoside had stronger effects than D-glucose. From this result, we can expect to find more effective carbohydrates to enhance transgene expression. The α- and β-M-D-glucosides, which are slightly different from each other in three-dimensional structure, exerted largely distinct stimulative effects on transgene expression, suggesting that fundamental rules determine the enhancive effects of saccharides and that the modification of the saccharide by applying such rules will enable us to develop more powerful substances for transgene expression.

[Clinical significance of apolipoprotein B-48 (apoB-48) in chronic kidney disease patients]

OBJECTIVES

Apolipoprotein B-48 (apoB-48) is a constituent of chylomicrons and their remnants, and high levels of serum apoB-48 are thought to be one of the risk factors for atherosclerosis. In the current study we examined whether serum apoB-48 level is associated with renal dysfunction.

METHODS AND RESULTS

Patients were separated by eGFR into each stage of chronic kidney disease (CKD). Serum apoB-48 levels were measured by chemiluminescence enzyme immunoassay (CLEIA), and serum lipid levels were compared between each stage of CKD. Serum triglyceride (TG) levels were high at stage 4 and stage 5. Serum total cholesterol, HDL-cholesterol (HDL-C), and LDL-cholesterol (LDL-C) levels were not significantly different. Serum apoB-48 level was significantly higher at stage 4 (Median: 8.3 microg/ml) and stage 5 (9.7 microg/ml) than at stage 1(4.2 microg/ml). Serum apoB-48 levels (10.7 microg/ml) in patients undergoing hemodialysis were not significantly higher than CKD patient of nondialysis (6.9 microg/ml).

CONCLUSION

Serum apoB-48 level was strongly associated with renal dysfunction. Therefore, increased serum apoB-48 concentrations may contribute to the increased risk of atherosclerosis and coronary artery disease in the CKD patients.

Association of human leukocyte antigen and T cell message with human papillomavirus 16–positive cervical neoplasia in Japanese women

To investigate whether an association exists between human leukocyte antigen (HLA) haplotype and cervical neoplasia within the Japanese population, we analyzed the human papillomavirus (HPV) genotypes, the HLA class I specificities and class II alleles, and the T-cell responses in the lesions of patients with cervical neoplasia. Eighty-one patients, consisting of 62 cervical intraepithelial neoplasia (CIN) lesions and 19 invasive cervical cancers (ICC), were examined. The frequencies of HPV infection in the CIN I/II and CIN III/ICC groups were 68.0% (17/25) and 80.4% (45/56), respectively. All patients and 138 local Japanese controls were analyzed for HLA-A, HLA-B, HLA-DRB1, and HLA-DQB1. For major histocompatibility complex (MHC) class II HLA-DRB1 alleles, the frequency of DRB1*0901 was significantly elevated in HPV 16–positive CIN III/ICC patients compared with controls (59.3% versus 29.7%, P= 0.0031, OR = 3.44). Similarly for the HLA-DQB1 alleles, a significant increase in the DQB1*03032 frequency was observed in HPV 16–positive CIN III/ICC patients compared with controls (59.3% versus 28.3%, P= 0.0018, OR = 3.69). In the analysis of the T-cell responses in the lesions, Fas ligand was detected at a decreased frequency in HPV 16–positive CIN III/ICC patients with the HLA-DRB1*0901–DQB1*03032 haplotype. The presence of helper T cell–specific messenger RNAs in the cervical lesions supports an association among MHC class II, helper T cells, the immune response to HPV, and the development of cervical carcinoma. Accordingly, a specific MHC class II haplotype, DRB1*0901–DQB1*03032, may be a risk factor for cervical carcinoma in the Japanese population.

Enhancement of the Curie Temperature by Isomerization of Diarylethene (DAE) for an Organic−Inorganic Hybrid System: Co4(OH)7(DAE)0.5·3H2O

Intercalation of an organic photochromic molecule into layered magnetic systems may provide multifunctional properties such as photomagnetism. To build up a photosensitive multifunctional magnet, an organic-inorganic hybrid system coupled with a photochromic diarylethene anion, 2,2'-dimethyl-3,3'-(perfluorocyclopentene-1,2-diyl)bis(benzo[b]thiophene-6-sulfonate) (DAE), and cobalt LDHs (layered double hydroxides), Co4(OH)7(DAE)0.5.3H2O, was synthesized by the anion exchange reaction between Co2(OH)3(CH3COO).H2O and DAE. In the dark and under UV-irradiated (313 nm) conditions, Co4(OH)7(DAE)0.5.3H2O with open and closed forms of DAE were obtained, respectively. The magnetic susceptibility measurements elucidated ferromagnetic intra- and interlayer interactions and Curie temperatures of TC = 9 and 20 K for cobalt LDHs with the open and closed forms of DAE, respectively. The enhancement of the Curie temperature from 9 to 20 K by substitution of the open form of DAE with the closed form of DAE as an intercalated molecule is attributed to the delocalization of the pi-electrons in the closed form of DAE, which enhances the interlayer magnetic interaction. The enhancement of the interlayer magnetic interaction induced by the delocalization of pi-electrons in intercalated molecules is strongly supported by the fact that the Curie temperature (26.0 K) of cobalt LDHs with (E,E)-2,4-hexadienedioate having a conjugated pi-electron system is enormously higher than that (7.0 K) of the cobalt LDHs with hexanedioate. By UV irradiation at 313 nm, Co4(OH)7(DAE)0.5.3H2O shows the photoisomerization of DAE from the open form to the closed one in the solid state, which leads to the enhancement of Curie temperature.

Neuropeptide Y Inhibits β-Adrenergic Agonist- and Vasoactive Intestinal Peptide-Induced Cyclic AMP Accumulation in Rat Pinealocytes Through Pertussis Toxin-Sensitive G Protein

The effects of neuropeptide Y (NPY) on pineal gland cyclic AMP (cAMP) accumulation were investigated using dispersed pinealocytes from rats. NPY inhibited the intracellular cAMP accumulation stimulated by isoproterenol and norepinephrine in a dose-dependent manner during a 10-min incubation of pinealocytes. NPY (1 x 10(-7) M) also inhibited vasoactive intestinal peptide (VIP)- and cholera toxin-induced cAMP accumulation. The inhibitory effect of NPY on isoproterenol-induced cAMP accumulation was completely abolished by a 5-h pretreatment of pinealocytes with 1 microgram/ml of pertussis toxin (PT). These results suggest that NPY participates in modulation of cAMP production in the rat pineal gland through PT-sensitive G protein. Yohimbine, an alpha 2-adrenergic antagonist, blocked NPY inhibition of isoproterenol-stimulated cAMP accumulation. On the other hand, the alpha 2-adrenergic agonist clonidine by itself did not affect cAMP accumulation stimulated by isoproterenol but significantly potentiated NPY action. The present study demonstrates that NPY inhibits beta-adrenergic or VIPergic stimulation of the pineal gland cAMP accumulation. The inhibitory effect of NPY is mediated through PT-sensitive G protein. Our results also suggest that NPY exerts its action to affect alpha 2-adrenoceptor function.

Association of the antagonism of von Willebrand factor but not fibrinogen by platelet alphaIIbbeta3 antagonists with prolongation of bleeding time

BACKGROUND

The alphaIIbbeta3 antagonists inhibit platelet aggregation and are used as antithrombotic agents for cardiothrombotic disease. The present study investigates the correlation of inhibition of fibrinogen and von Willebrand factor (VWF) binding by alphaIIbbeta3 antagonists with the inhibition of platelet aggregation and prolongation of bleeding time (BT).

METHODS

Inhibition of fibrinogen and VWF binding were assessed in a purified alphaIIbbeta3-binding assay. As an in vitro cell-based assay, platelet aggregation and VWF-mediated adhesion studies were performed using human platelets. In vivo effects on BT were measured using a template device in dogs at the same time as an ex vivo aggregation study was performed.

RESULTS

In vitro studies demonstrated that the antiaggregatory effects of alphaIIbbeta3 antagonists correlate with their inhibition of fibrinogen binding, but not VWF. Interestingly, the effects of alphaIIbbeta3 antagonists on BT could be differentiated from the inhibition of platelet aggregation. Furthermore, this differentiation was strongly correlated with the different inhibitory potencies between fibrinogen and VWF binding, as well as that between VWF-mediated adhesion and aggregation.

CONCLUSIONS

Our study provides novel evidence showing that the inhibitory effect of alphaIIbbeta3 antagonists on VWF, but not fibrinogen binding, correlates with their ability to prolong BT.

A comparison between Japanese-Americans living in Hawaii and Los Angeles and native Japanese: the impact of lifestyle westernization on diabetes mellitus

We have been conducting the Hawaii-Los Angeles-Hiroshima Study since 1970, mainly to determine the effects of environmental changes on various diseases by comparing Japanese-Americans with native Japanese subjects. Japanese-Americans living in Hawaii and Los Angeles are originated mainly from Hiroshima, Japan and are genetically identical with native Japanese. Through this study, we made several clear observations about Japanese-Americans. First, Japanese-Americans were highly exposed to a westernized lifestyle ; in other words, a relatively high fat and simple carbohydrate diet with low physical activity as compared to native Japanese. Second, the prevalence of type 2 diabetes among Japanese-Americans and death from ischemic heart disease among Japanese-American diabetic patients were higher. Third, the serum fasting insulin level as well as the insulin level after a glucose load, was higher among Japanese-Americans, even when the serum glucose levels were not statistically different as compared to native Japanese. Accordingly, Japanese-Americans were thought to have a high insulin resistance status. However, the initial insulin response after a glucose load was low, which was more similar to Japanese people than to Caucasians. Fourth, the total cholesterol and triglyceride levels were higher among Japanese-Americans. These results are supposed to be derived from the insulin resistant status by the westernization of lifestyle, as well as from the weakness of pancreatic beta cell function that is supposed to be genetically regulated among Japanese. In conclusion, it appears that for genetically Japanese people, environmental factors are important for the development of metabolic diseases such as diabetes mellitus and cardiovascular disease.

Post-challenge hyperglycaemia is an independent risk factor for arterial stiffness in Japanese men

AIMS

Arterial stiffness is an independent predictor of cardiovascular disease, but the impact of post-challenge hyperglycaemia on arterial stiffness is unknown. To investigate the association between arterial stiffness and post-challenge hyperglycaemia, we measured the second derivative of photoplethysmogram as an indicator of arterial stiffness.

METHODS

This study was done in 159 asymptomatic Japanese men aged 50.7 +/- 13.0 years. All subjects underwent a 75-g oral glucose tolerance test and measurement of the second derivative of photoplethysmogram.

RESULTS

According to the World Health Organization criteria (1998), 110 subjects had normal glucose tolerance, 10 had impaired fasting glucose, 30 had impaired glucose tolerance, and nine had diabetes. The b/a ratio (an index of arterial stiffness) showed a significant relationship with age (r = 0.58, P < 0.0001), height (r = -0.33, P < 0.0001), 2-h post-challenge glucose (r = 0.32, P < 0.0001), systolic blood pressure (r = 0.22, P = 0.006), and diastolic blood pressure (r = 0.21, P = 0.009). After adjustment for age and height, there were significant correlations between the b/a ratio and diastolic blood pressure (r = 0.18, P = 0.02), fasting glucose (r = 0.16, P = 0.049), and 2-h post-challenge glucose (r = 0.21, P = 0.009). Stepwise multiple regression analysis showed that only age (beta= 0.006, SE = 0.0007, P < 0.001) and 2-h post-challenge glucose (beta = 0.0005, SE = 0.0002, P < 0.05) contributed significantly to the b/a ratio (adjusted R(2) = 0.38).

CONCLUSIONS

These results indicate that post-challenge hyperglycaemia is an independent risk factor for arterial stiffness.

Erectile dysfunction is strongly linked with decreased libido in diabetic men

Erectile dysfunction frequently occurs with diabetes mellitus. A survey of diabetic men was conducted by anonymous questionnaire to investigate the associations of erectile dysfunction with various predictive factors. A total of 112 diabetic males without an obvious history of erectile dysfunction were available for analyses. The mean age and duration of diabetes were 53.7 +/- 12.2 years and 10.2 +/- 8.6 years (mean +/- standard deviation), respectively. The questionnaire included questions on the presence or absence of smoking, hypertension, libido and subjective symptoms of diabetic neuropathy that may be associated with erectile dysfunction. Analysis of the answers to the questionnaire revealed that 40% of the patients complained of erectile dysfunction (erection 'always insufficient'). Erectile dysfunction was significantly correlated with age (p = 0.005), but not with duration of diabetes (p = 0.25), adjusted for age. Erectile dysfunction was also associated with sensory neuropathy and reduced libido, independently of age. The logistic regression analysis revealed that erectile dysfunction was positively associated with reduced libido and age. The odds ratio of erectile dysfunction for reduced compared to unreduced libido was 18.21, suggesting that psychogenic factors have a marked influence on erectile dysfunction. It is concluded that the presence of erectile dysfunction should be considered when symptoms related to diabetic neuropathy are observed; psychological approaches, such as sexual counseling, could be applied for the treatment of erectile dysfunction.