[A multicenter study of reference intervals for 15 laboratory parameters in Chinese children]

Objective: To establish comprehensive laboratory reference intervals for Chinese children. Methods: This was a cross-sectional multicenter study. From June 2013 to December 2014, eligible healthy children aged from 6-month to 17-year were enrolled from 20 medical centers with informed consent. They were assessed by physical examination, questionnaire survey and abdominal ultrasound for eligibility. Fasting blood samples were collected and delivered to central laboratory. Measurements of 15 clinical laboratory parameters were performed, including estradiol (E2), testosterone(T), luteinizing hormone(LH), follicle-stimulating hormone(FSH), alanine transaminase(ALT), serum creatinine(Scr), cystatin C, immunoglobulin A(IgA), immunoglobulin G(IgG), immunoglobulin M(IgM), complement (C3, C4), alkaline phosphatase(ALP), uric acid(UA) and creatine kinase(CK). Reference intervals were established according to central 95% confidence intervals for reference population, stratified by age and sex. Results: In total, 2 259 children were enrolled. Finally, 1 648 children were eligible for this study, including 830 boys and 818 girls, at a mean age of 7.4 years. Age- and sex- specific reference intervals have been established for the parameters. Reference intervals of sex hormones increased gradually with age. Concentrations of ALT, cystatin C, ALP and CK were higher in children under 2 years old. Serum levels of sex hormones, creatinine, immunoglobin, CK, ALP and urea increased rapidly in adolescence, with significant sex difference. In addition, reference intervals were variable depending on assay methods. Concentrations of ALT detected by reagents with pyridoxal 5'-phosphate(PLP) were higher than those detected by reagents without PLP. Compared with enzymatic method, Jaffe assay always got higher results of serum creatinine, especially in children younger than 9 years old. Conclusion: This study established age- and sex- specific reference intervals, for 15 clinical laboratory parameters based on defined healthy children.

Comparison of pregnancy outcomes between women with gestational diabetes and overt diabetes first diagnosed in pregnancy: a retrospective multi-institutional study in Japan

AIMS

To determine differences in pregnancy outcomes including diabetic complications, maternal and perinatal complications between gestational diabetes mellitus and overt diabetes in pregnancy in Japan.

METHODS

A multi-institutional retrospective study compared pregnancy outcomes between gestational diabetes mellitus and overt diabetes in pregnancy. We examined pregnant women who met the former criteria for gestational diabetes mellitus and received dietary intervention with self-monitoring of blood glucose with or without insulin. Overt diabetes in pregnancy was defined as ≥2 abnormal values on 75-g oral glucose tolerance test, fasting glucose ≥126 mg/dl (7.0 mmol/l) and 2-h postprandial glucose ≥200 mg/dl (11.1 mmol/l), or glycated hemoglobin levels ≥6.5% (48 mmol/mol).

RESULTS

Data were collected on 1267 women with gestational diabetes and 348 with overt diabetes in pregnancy. Pregestational body mass index was higher (26.2 ± 6.1 vs. 24.9 ± 5.7 kg, P<0.05) and gestational age at delivery was earlier (37.8 ± 2.5 weeks vs. 38.1 ± 2.1 weeks, P<0.05) in overt diabetes than in gestational diabetes. Glycated hemoglobin (6.8 ± 1.1% [51 mmol/mol] vs. 5.8 ± 0.5% [40 mmol/mol], P<0.05) and glucose on 75-g oral glucose tolerance test and prevalence of retinopathy (1.2% vs. 0%, P<0.05) and pregnancy-induced hypertension (10.1% vs. 6.1%, P<0.05) were higher in overt diabetes than in gestational diabetes. Pregnancy-induced hypertension was associated with pregestational body mass index, gestational weight gain, chronic hypertension, and nulliparity but not with 75-g oral glucose tolerance test.

CONCLUSIONS

Overt diabetes in pregnancy is significantly associated with maternal complications such as retinopathy and pregnancy-induced hypertension.

Simultaneous assay of activated platelet count and platelet-activating capacity by P-selectin detection using K2-EDTA-treated whole blood for antiplatelet agents

INTRODUCTION

It is well recognized that examinations of activated platelets (aPLTs) and platelet-activating capacity are very important to observe and prevent embolic diseases (events) such as ischemic stroke and myocardial infarction. Previously, we reported an appropriate measurement technique of aPLT for clinical assay. In this paper, we investigated stable conditions for measurement of activating capacity of platelets.

METHODS

Blood samples were taken from healthy volunteers using anticoagulants of 2K-EDTA, sodium citrate and heparin, and platelets were stimulated with adenosine diphosphate (ADP) or collagen. We demonstrated platelet-activating capacity by detection of scattering light, absorbance, microscopic observation, and P-selectin (CD62P) expression. We also performed basic experiments in seven healthy volunteers to test the clinical application of these assays with monitoring aspirin therapy.

RESULTS

We judged that samples of whole blood with 2K-EDTA were suitable for CD62P expression assay as functional assessments of platelet activity, because platelets treated with anticoagulants such as sodium citrate and heparin were extremely damaged after stimulation, and it was difficult to measure the CD62P expression by flow cytometry. For optimal results, samples should be tested within 1 h after the drawing of blood and stimulated with ADP or collagen for 10 min. The CD62P-positive platelet value of blood from volunteers who had taken aspirin was decreased, and platelet activation was inhibited as well.

CONCLUSION

The simultaneous assay of aPLT and platelet-activating capacity by CD62P detection using whole blood treated with the K2-EDTA anticoagulant was useful for the monitoring of antiplatelet drugs.

A new predictive indicator for development of pressure ulcers in bedridden patients based on common laboratory tests results

Background:

Various scales have been devised to predict development of pressure ulcers on the basis of clinical and laboratory data, such as the Braden Scale (Braden score), which is used to monitor activity and skin conditions of bedridden patients. However, none of these scales facilitates clinically reliable prediction.

Aims:

To develop a clinical laboratory data-based predictive equation for the development of pressure ulcers.

Methods:

Subjects were 149 hospitalised patients with respiratory disorders who were monitored for the development of pressure ulcers over a 3-month period. The proportional hazards model (Cox regression) was used to analyse the results of 12 basic laboratory tests on the day of hospitalisation in comparison with Braden score.

Results:

Pressure ulcers developed in 38 patients within the study period. A Cox regression model consisting solely of Braden scale items showed that none of these items contributed to significantly predicting pressure ulcers. Rather, a combination of haemoglobin (Hb), C-reactive protein (CRP), albumin (Alb), age, and gender produced the best model for prediction. Using the set of explanatory variables, we created a new indicator based on a multiple logistic regression equation. The new indicator showed high sensitivity (0.73) and specificity (0.70), and its diagnostic power was higher than that of Alb, Hb, CRP, or the Braden score alone.

Conclusions:

The new indicator may become a more useful clinical tool for predicting presser ulcers than Braden score. The new indicator warrants verification studies to facilitate its clinical implementation in the future.

Common carotid intima-media thickness is predictive of all-cause and cardiovascular mortality in elderly community-dwelling people: Longitudinal Investigation for the Longevity and Aging in Hokkaido County (LILAC) study

Several cohort studies have examined the association of carotid intima-media thickness (IMT) with the risk of stroke or myocardial infarction in apparently healthy persons. We investigated the predictive value of IMT of cardiovascular mortality in elderly community-dwelling people, beyond the prediction provided by age and MMSE, assessed by means of a multivariate Cox model. Carotid IMT and plaque were evaluated bilaterally with ultrasonography in 298 people older than 75 years (120 men and 178 women, average age: 79.6 years). The LILAC study started on July 25, 2000. Consultations were repeated every year. The follow-up ended on November 30, 2004. During the mean follow-up span of 1152 days, 30 subjects (21 men and nine women) died. Nine deaths were attributable to cardiovascular causes (myocardial infarction: two men and three women; stroke: two men and two women). The age- and MMSE-adjusted relative risk (RR) and 95% confidence interval (95% CI) of developing all-cause mortality was assessed. A 0.3 mm increase in left IMT was associated with a RR of predicted 1.647 (1.075-2.524), and a similar increase in right IMT with a RR of 3.327 (1.429-7.746). For cardiovascular mortality, the corresponding RR values were 2.351 (1.029-5.372) and 2.890 (1.059-7.891), respectively. Carotid IMT assessed by ultrasonography is positively associated with an increased risk of all-cause and cardiovascular death in elderly community-dwelling people.

Effect of aging on blood pressure in Leh, Ladakh, a high-altitude (3524 m) community, by comparison with a Japanese town

The effect of aging on blood pressure (BP) and heart rate (HR) was investigated in a cross-sectional study in the high-altitude community of Leh, Ladakh (altitude: 3524 m) and a Japanese community in U town, Hokkaido (altitude: 25 m). BP and HR were obtained in a sitting position from 332 subjects 13-81 years of age in Ladakh, and from 216 Japanese citizens, 24-79 years of age. Measurements were taken after a 2-min rest, using a semi-automated BP device (UA-767 PC, A and D Co. LTD, Tokyo). High-altitude people showed higher diastolic BP and HR values than lowland people (83.2 vs. 76.9 mmHg and 78.6 vs. 69.2 bpm, P < 0.001), but no difference in systolic BP. Highland people also showed a steeper BP increase with age than the lowland people (systolic BP: 0.7476 vs. 0.3179 mmHg/year, P < 0.0005; diastolic BP: 0.3196 vs. 0.0750 mmHg/year, P < 0.001). This chronoecologic investigation in Ladakh examined the circulation as a physiological system at high-altitude. Our data indicate the need for a more comprehensive cardiovascular assessment for a better diagnosis and a more fruitful treatment. Longitudinal observations of effects of socio-ecologic factors on the cardiovascular system should help prevent strokes and other cardiovascular events, especially at high altitude.

Depressive mood is independently related to stroke and cardiovascular events in a community

By means of a multivariate Cox model, we investigated the predictive value of a depressive mood on vascular disease risk in middle-aged community-dwelling people. In 224 people (88 men and 136 women; mean age: 56.8 +/- 11.2 years) of U town, Hokkaido (latitude: 43.45 degrees N, longitude: 141.85 degrees E), a chronoecological health watch was started in April 2001. Consultations were repeated every 3 months. Results at the November 30, 2004 follow-up are presented herein. 7-day/24-h blood pressure (BP) and heart rate (HR) monitoring started on a Thursday, with readings taken at 30-min intervals between 07:00 h and 22:00 h and at 60-min intervals between 22:00 h and 07:00 h. Data stored in the memory of the monitor (TM-2430-15, A and D company, Japan) were retrieved and analyzed on a personal computer with a commercial software for this device. Subjects were asked to answer a self-administered questionnaire inquiring about 15 items of a depression scale, at the start of study and again after 1-2 years. Subjects with a score higher by at least two points at the second versus first screening were classified as having a depressive mood. The other subjects served as the control group. The mean follow-up time was 1064 days, during which four subjects suffered an adverse vascular outcome (myocardial infarction: one man and one woman; stroke: two men). Among the variables used in the Cox proportional hazard models, a depressive mood, assessed by the Geriatric Depression Scale (GDS), as well as the MESOR of diastolic (D) BP (DBP-MESOR) and the circadian amplitude of systolic (S) BP (SBP-Amplitude) showed a statistically significant association with the occurrence of adverse vascular outcomes. The GDS score during the second but not during the first session was statistically significantly associated with the adverse vascular outcome. In univariate analyses, the relative risk (RR) of developing outcomes was predicted by a three-point increase in the GDS scale (RR = 3.088, 95% CI: 1.375-6.935, P = 0.0063). Increases of 5 mmHg in DBP-MESOR and of 3 mmHg in SBP-Amplitude were associated with RRs of 2.143 (95% CI: 1.232-3.727, P = 0.0070) and 0.700 (95% CI: 0.495-0.989, P = 0.0430), respectively. In multivariate analyses, when both the second GDS score and the DBP-MESOR were used as continuous variables in the same model, GDS remained statistically significantly associated with the occurrence of cardiovascular death. After adjustment for DBP-MESOR, a three-point increase in GDS score was associated with a RR of 2.172 (95% CI: 1.123-4.200). Monday endpoints of the 7-day profile showed a statistically significant association with adverse vascular outcomes. A 5 mmHg increase in DBP on Monday was associated with a RR of 1.576 (95% CI: 1.011-2.457, P = 0.0446). The main result of the present study is that in middle-aged community-dwelling people, a depressive mood predicted the occurrence of vascular diseases beyond the prediction provided by age, gender, ABP, lifestyle and environmental conditions, as assessed by means of a multivariate Cox model. A depressive mood, especially enhanced for 1-2 years, was associated with adverse vascular outcomes. Results herein suggest the clinical importance of repetitive assessments of a depressive mood and the need to take sufficient care of depressed subjects. Another result herein is that circadian and circaseptan characteristics of BP variability measured 7-day/24-h predicted the occurrence of vascular disease beyond the prediction provided by age, gender, depressive mood and lifestyle, as assessed by means of a multivariate Cox model. Earlier, we showed that the morning surge in BP on Mondays was statistically significantly higher compared with other weekdays. Although a direct association between the Monday surge in BP and cardiovascular events could not be demonstrated herein, it is possible that the BP surge on Monday mornings may also trigger cardiovascular events. We have shown that depressive people exhibit a more prominent circaseptan variation in SBP, DBP and the double product (DP) compared to non-depressed subjects. In view of the strong relation between depression and adverse cardiac events, studies should be done to ascertain that depression is properly diagnosed and treated. Chronodiagnosis and chronotherapy can reduce an elevated blood pressure and improve the altered variability in BP and HR, thus reducing the incidence of adverse cardiac events. This recommendation stands at the basis of chronomics, focusing on prehabilitation in preference to rehabilitation, as a public service offered in several Japanese towns.

Arterial stiffness independently predicts cardiovascular events in an elderly community — Longitudinal Investigation for the Longevity and Aging in Hokkaido County (LILAC) study

We investigated the predictive value of arterial stiffness to assess cardiovascular risk in elderly community-dwelling people by means of a multivariate Cox model. In 298 people older than 75 years (120 men and 178 women, average age: 79.6 years), brachial-ankle pulse wave velocity (baPWV) was measured between the right arm and ankle in a supine position. The LILAC study started on July 25, 2000, consultation was repeated yearly, and the last follow-up ended on November 30, 2004. During this follow-up span of 1227 days, there were nine cardiovascular deaths, the cause of death being myocardial infarction for two men and three women or stroke for two men and two women. In Cox proportional hazard models, baPWV as well as age, Mini-Mental State Examination (MMSE), Hasegawa Dementia Scale Revised (HDSR) and the low-frequency/high-frequency (LF/HF) ratio showed a statistically significant association with the occurrence of cardiovascular death. A two-point increase in MMSE and HDSR score significantly protected against cardiovascular death, the relative risk (RR) being 0.776 (P = 0.0369) and 0.753 (P = 0.0029), respectively. The LF/HF ratio also was significant (P = 0.025), but the other indices of HRV were not. After adjustment for age and HDSR, a 200 cm/s increase in baPWV was associated with a 30.2% increase in risk (RR = 1.302, 95% CI: 1.110-1.525), and a 500 cm/s increase in baPWV with a 93.3% increase in risk (RR = 1.933, 95% CI: 1.300-2.874, P = 0.0011), whereas the LF/HF ratio was no longer associated with a statistically significant increase in cardiovascular mortality. In elderly community-dwelling people, arterial stiffness measured by means of baPWV predicted the occurrence of cardiovascular death beyond the prediction provided by age, gender, blood pressure and cognitive functions. baPWV should be added to the cardiovascular assessment in various clinical settings, including field medical surveys and preventive screening. The early detection of risk by chronomics allows the timely institution of prophylactic measures, thereby shifting the focus from rehabilitation to prehabilitation medicine, as a public service to several Japanese towns.

Chronoecological health watch of arterial stiffness and neuro-cardio-pulmonary function in elderly community at high altitude (3524 m), compared with Japanese town

Effects of high altitude on arterial stiffness and neuro-cardio-pulmonary function were studied. Blood pressure (BP) and heart rate (HR) were measured in a sitting position on resting Ladakhis, living at an altitude of 3250-4647 m (Phey village, 3250 m: 17 men and 55 women; Chumathang village, 4193 m: 29 men and 47 women; Sumdo village, 4540 m: 38 men and 57 women; and Korzok village, 4647 m: 84 men and 70 women). The neuro-cardio-pulmonary function, including the Kohs block design test, the Up and Go, the Functional Reach and the Button tests, was examined in 40 elderly subjects (19 men and 21 women, mean age: 74.7 +/- 3.3 years) in Leh, Ladakh (altitude: 3524 m), for comparison with 324 elderly citizens (97 men and 227 women, mean age: 80.7 +/- 4.7 years) of Tosa, Japan (altitude: 250 m). Cardio-Ankle Vascular Index (CAVI) was measured as the heart-ankle pulse wave velocity (PWV) in these subjects using a VaSera CAVI instrument (Fukuda Denshi, Tokyo). SpO(2) decreased while Hb and diastolic BP increased with increasing altitude. At higher altitude, residents were younger and leaner. Women in Leh vs. Tosa had a poorer cognitive function, estimated by the Kohs block design test (3.7 +/- 3.6 vs. 16.4 +/- 9.6 points, P < 0.0001) and poorer ADL functions (Functional Reach: 13.7 +/- 7.0 cm vs. 25.3 +/- 8.7 cm, P < 0.0001; Button test: 22.5 +/- 4.8 vs. 14.8 +/- 5.7 s, P < 0.0001). Time estimation was shorter at high altitude (60-s estimation with counting: 41.1% shorter in men and 23.0% shorter in women). A higher voltage of the QRS complex was observed in the ECG of Leh residents, but two times measurement of CAVI showed no statistically significant differences between Leh and Tosa (two times of CAVI measures; 9.49 vs. 10.01 m/s and 9.41 vs. 10.05 m/s, respectively), suggesting that most residents succeed to adapt sufficiently to the high-altitude environment. However, correlation of CAVI with age shows several cases who show an extreme increase in CAVI. Thus, for the prevention of stroke and other adverse cardiovascular outcomes, including dementia, CAVI may be very useful, especially at high altitude. In conclusion, elderly people living at high altitude have a higher risk of cardiovascular disease than low-latitude peers. To determine how these indices are associated with maintained cognitive function deserves further study by the longitudinal follow-up of these communities in terms of longevity and aging in relation to their neuro-cardio-pulmonary function.

Fractal analysis of heart rate variability and mortality in elderly community-dwelling people — Longitudinal Investigation for the Longevity and Aging in Hokkaido County (LILAC) study

AIM

Fractal analysis of heart rate (HR) variability (HRV) has been used as a new approach to evaluate the risk of mortality in various patient groups. Aim of this study is to examine the prognostic power of detrended fluctuation analysis (DFA) and traditional time- and frequency-domain analyses of HR dynamics as predictors of mortality among elderly people in a community.

METHODS

We examined 298 people older than 75 years (average age: 79.6 years) and 1-h ambulatory ECG was monitored. During the last 10 min, deep respiration (6-s expiration and 4-s inspiration) was repeated six times in a supine position. Time-domain and frequency-domain measures were determined by the maximum entropy method. Scaling exponents of short-term (<11 beats, alpha 1) and longer-term (>11 beats, alpha 2) were determined by the DFA method. Six estimates, obtained from 10-min segments, were averaged to derive mean values for the entire recording span. These average values were denoted Alpha 1 and Alpha 2, estimates obtained during the first 10-min segment Alpha 1 S and Alpha 2 S, and those during the last 10-min segment Alpha 1E and Alpha 2E, respectively. The LILAC study started on July 25, 2000 and ended on November 30, 2004. We used Cox regression analysis to calculate relative risk (RR) and 95% confidence interval (CI) for all-cause mortality. Significance was considered at a value of P < 0.05.

RESULTS

Gender, age and Alpha 2E showed a statistically significant association with all-cause mortality. In univariate analyses, gender was significantly associated with all-cause mortality, being associated with a RR of 3.59 (P = 0.00136). Age also significantly predicted all-cause mortality and a 5-year increase in age was associated with a RR of 1.49 (P = 0.01809). The RR of developing all-cause mortality predicted by a 0.2-unit increase in Alpha 2E was 0.58 (P = 0.00390). Other indices of fractal analysis of HRV did not have predictive value. In multivariate analyses, when both Alpha 2E and gender were used as continuous variables in the same model, Alpha 2E remained significantly associated with the occurrence of all-cause mortality (P = 0.02999). After adjustment for both gender and age, a 0.2-unit increase in Alpha 2E was associated with a RR of 0.61 (95% CI: 0.42-0.90, p = 0.01151).

CONCLUSION

An intermediate-term fractal-like scaling exponent of RR intervals was a better predictor of death than the traditional measures of HR variability in elderly community-dwelling people. It is noteworthy that the longer-term (alpha 2) rather than the short-term fractal component (alpha 1) showed predictive value for all-cause mortality, which suggests that an increase in the randomness of intermediate-term HR behavior may be a specific marker of neurohumoral and sympathetic activation and therefore may also be associated with an increased risk of mortality.

Tolerance to nitroglycerin induced by isosorbide-5-mononitrate infusion in vivo

We examined the development of tolerance to nitroglycerin (glyceryl trinitrate; GTN) in the rat when isosorbide-5-mononitrate (ISMN) or GTN was continuously infused. Under pentobarbital anesthesia (60 mg/kg, i.p.), mean arterial blood pressure was measured via the left common carotid artery. Bolus injection of ISMN (0.25-250 mg/kg) and GTN (0.25 microg/kg-2.5 mg/kg) was made into the right external jugular vein. ISMN (2.5 mg/h/rat for 7 d), GTN (1.3 microg/h/rat for 7 d), or GTN (0.2 mg/h/rat for 3 d) was infused continuously using an osmotic pump embedded subcutaneously. Bolus injection of ISMN and GTN decreased arterial blood pressure in a dose-dependent manner. The hypotensive effect of ISMN was 2000 times less potent than that of GTN. The GTN-induced hypotensive effect was not affected after continuous infusion of ISMN, whereas it was attenuated after continuous infusion of GTN at either dose. Chronic treatment with ISMN does not induce GTN tolerance as easily as treatment with GTN.

Evidence-based laboratory interpretation system built on a large collection of case records with well-defined diagnoses

A computer-based system for laboratory diagnosis was created to promote evidence-based practice of laboratory medicine. It runs on a database consisting of 1992 well-defined untreated cases from 38 common diagnostic categories. Clinical symptoms, signs, and severity were recorded together with laboratory test results both general and specific to the clinical diagnosis. The system has two modes in which to view the database: either single or multiple diagnostic categories at a time. In the single mode, it allows flexible filtering and quick subgrouping of cases within the diagnostic category by specifying parameters of interest. It is also capable of computing a similarity index of a case at hand to those in the database. The index is defined as a weighted sum of log-likelihood calculated dynamically from parameters chosen for the query. In the multi-mode, only the parameters commonly recorded in selected categories are retrieved from the database. The system offers a between-category comparison view of any parameter. The similarity indices can be also computed among categories to see how well a set of parameters differentiates a reference category from the others.

Standardization of immunoassay for CRM-related proteins in Japan: from evaluating CRM 470 to setting reference intervals

The Japan National Institute of Health (JNIH), in close collaboration with academic societies, commercial companies, and the Japan Society of Medical Technologists, has led in the attempt to standardize plasma protein assays since the mid 1980s. Under a framework of global standardization, they used WHO primary reference materials to reduce discrepancies in values reported for proteins assayed using different systems, thus laying the foundations for a protein immunoassay standardization system in Japan. With the introduction of CRM 470 in 1993, the Japanese Committee for Clinical Laboratory Standards (JCCLS) has taken the initiative in promoting the use of the new material and bringing about the re-evaluation of all systems of quality assurance in clinical laboratories. This eventually led to the establishment of reference intervals in Japanese populations of children and adults after preparation of assigned calibrators from CRM 470 for each assay system. Here we review the history of a series of projects carried out in Japan and describe several remaining problems, through which we will attempt to evaluate the potential value of protein immunoassay standardization.

Simvastatin and atorvastatin enhance hypotensive effect of diltiazem in rats

Effects of the 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase inhibitors, simvastatin and atorvastatin, on diltiazem-induced hypotension were examined in anaesthetized rats and compared to that of pravastatin. Vehicle, 2 mg/kg/day simvastatin, 2 mg/kg/day atorvastatin, or 4 mg/kg/day pravastatin was administered orally for 4 days. Diltiazem at 3 mg/kg was given orally 2 hours after the final administration of the inhibitors. Arterial blood pressure was measured via a cannula introduced into the left carotid artery, and heart rate was counted from the pulse pressure. In all groups, diltiazem significantly decreased the mean arterial blood pressure without any changes in heart rate. Pretreatment with simvastatin and atorvastatin significantly enhanced the hypotensive effect of diltiazem, while that with pravastatin did not. Heart rate was not modified by pretreatment with the inhibitors. The results indicate that concomitant use of diltiazem with simvastatin or atorvastatin enhances diltiazem-induced hypotension, probably by competitive inhibition of diltiazem metabolism with simvastatin and atorvastatin metabolisms.

Site-directed mutagenesis of the putative distal helix of peroxygenase cytochrome P450

CYP152A1 is an unusual, peroxygenase enzyme that catalyzes the beta- or alpha-hydroxylation of fatty acids by efficiently introducing an oxygen atom from H2O2 to the fatty acid. To clarify the mechanistic roles of amino acid residues in this enzyme, we have used site-directed mutagenesis of residues in the putative distal helix and measured the spectroscopic and enzymatic properties of the mutant proteins. Initially, we carried out Lys-scanning mutagenesis of amino acids in this region to determine residues of CYP152A1 that might have a mechanistic role. Among the Lys mutants, only P243K gave an absorption spectrum characteristic of a nitrogenous ligand-bound form of a ferric P450. Further investigation of the Pro243 site revealed that a P243H mutant also exhibited a nitrogen-bound form, but that the mutants P243A or P243S did not. On the hydroxylation of myristic acid by the Lys mutants, we observed a large decrease in activity for R242K and A246K. We therefore examined other mutants at amino acid positions 242 and 246. At position 246, an A246K mutant showed a roughly 19-fold lower affinity for myristic acid than the wild type. Replacing Ala246 with Ser decreased the catalytic activity, but did not affect affinity for the substrate. An A246V mutant showed slightly reduced activity and moderately reduced affinity. At position 242, an R242A showed about a fivefold lower affinity than the wild type for myristic acid. The Km values for H2O2 increased and Vmax values decreased in the order of wild type, R242K, and R242A when H2O2 was used; furthermore, Vmax/Km was greatly reduced in R242A compared with the wild type. If cumene hydroperoxide was used instead of H2O2, however, the Km values were not affected much by these substitutions. Together, our results suggest that in CYP152A1 the side chain of Pro243 is located close to the iron at the distal side of a heme molecule; the fatty acid substrate may be positioned near to Ala246 in the catalytic pocket, although Ala246 does not participate in hydrophobic interactions with the substrate; and that Arg242 is a critical residue for substrate binding and H2O2-specific catalysis.

Visualization of the stop of microtubule depolymerization that occurs at the high-density region of microtubule-associated protein 2 (MAP2)

Individual microtubules (MTs) repeat alternating phases of polymerization and depolymerization, a process known as dynamic instability. Microtubule-associated proteins (MAPs) regulate the dynamic instability by increasing the rescue frequency. To explore the influence of MAP2 on in vitro MT dynamics, we correlated the distribution of MAP2 on individual MTs with the dynamic phase changes of the same MTs. MAP2 was modified selectively on its projection region by X-rhodamine iodoacetamide without altering the MT-binding activity. When the labeled MAP2 was added to MTs, the fluorescence was distributed along almost the entire length of individual MTs. However, the inhomogeneity of the distribution gradually became obvious due to the fluorescence bleaching, and the MTs appeared to consist of rapidly bleached portions (RBPs) and slowly bleached portions (SBPs), which were distributed randomly along the MT. By measuring the duration of fluorescence bleaching, the density of MAP2 in SBP was estimated to be approximately 2.5 times higher than the RBP. The average tubulin:MAP2 ratio in SBP was calculated to be 16. When the MT dynamics were observed by dark-field microscopy after determining the MAP2 distribution, rescues were always found to occur only at the SBPs. MTs also displayed intermittent shortening by repeated depolymerization phases separated by pause phases. In these cases, depolymerization phases stopped only at the SBPs. Not every SBP stopped depolymerization, but depolymerization always stopped at an SBP. Taken together, we suggest that there is a minimum density of MAP2 that is necessary to stop depolymerization.

[Standardization of statistical procedures and evaluation scheme in external quality-control survey]

Numerous external quality assessment surveys are being conducted by variety of organizations throughout Japan, but the statistical processing and evaluation scheme are not compatible. Standardization of the procedures is essential to make comparison of results among surveys possible. A coding system is available only for names of analytes and analytical equipments. Systematic coding for analytical principles, manufacturers and standard materials is necessary. Regarding computation of peer-group statistics, the mean and SD are often biased when there are many, or wildly, outlying values. Therefore it is recommended to use an iterative method. The methodology removes a relatively large proportion of the population in the tails of the distribution and re-inflates the SD to compensate for the trimming, thus reaching an unbiased mean and SD by iteration. It is also useful to compute between-method CV and within method-CV by one-way analysis of variance. They represent overall levels of standardization and reproducibility of the analyte, respectively. The evaluation of results is usually based on the peer-group mean and SD. The scheme is unfair for those belonging to a peer-group with a narrow SD. It is recommended to use so-called "common CV evaluation scheme", which is based on a within-method CV computed from overall test results after excluding those peer-groups with large CVs. The common CV is applied to the unbiased peer-group mean to get the evaluation SD. For standardized data processing and statistical analysis, it is crucial to develop a unified, generalized soft ware. We developed its prototype named SurveyMaster I & II and herein introduce their potentials.

Limitation of heart growth in neonatal piglets by simvastatin and atorvastatin: comparison with pravastatin

The pig heart grows rapidly in the first few days after birth. We examined the effects of simvastatin, atorvastatin, and pravastatin on heart growth in piglets. After vehicle, 2 mg · kg−1 · day−1simvastatin, 2 mg · kg−1 · day−1atorvastatin, or 4 mg · kg−1 · day−1 pravastatin were administered orally for 6 days, the thoracic cavity was opened, and the heart was removed under pentobarbital sodium (30 mg/kg ip) anesthesia. The heart was perfused to remove residual blood. After the heart was blotted dry, the right and left ventricular free walls were dissected. Each free wall was weighed and used for determination of DNA, RNA, and protein concentrations and mitogen-activated protein (MAP) kinase activity. Simvastatin and atorvastatin resulted in smaller increases with age in the weight, concentrations of RNA and protein, and activity of MAP kinase in the left ventricular free wall, whereas pravastatin did not. The parameters of heart growth in the right ventricular free wall were not appreciably affected by either drug. The blood pressure and heart rate were not changed by the treatments. These results suggest that simvastatin and atorvastatin interfere with heart growth in neonatal piglets after birth, especially in the left ventricular free wall.

3-Hydroxy-3-methylglutaryl-CoA reductase inhibitors block calcium-dependent tyrosine kinase Pyk2 activation by angiotensin II in vascular endothelial cells. involvement of geranylgeranylation of small G protein Rap1

We recently reported the calcium-dependent activation of tyrosine kinase Pyk2 by angiotensin II (Ang II) in pulmonary vein endothelial cells (PVEC). Since Pyk2 has no calcium binding domain, and neither Ca(2+) nor Ca(2+)/calmodulin directly activates Pyk2, it is not clear how Ca(2+) transduces the signal to activate Pyk2, a key tyrosine kinase, in the early events of Ang II signaling. In the present study, we investigated the mechanism of the calcium-dependent activation of Pyk2 in response to Ang II by using 3-hydroxy-3-methylglutaryl-CoA reductase inhibitors and isoprenoid intermediates in PVEC. We have obtained substantial evidence indicating that Ang II activates Pyk2 through calcium-mediated activation of the geranylgeranylated small G protein Rap1 and the Rap1 association with Pyk2. Thus, the small G protein Rap1 is an intermediary signaling molecule linking Ang II-induced calcium signal to Pyk2 activation in PVEC. In addition, our results indicate that 3-hydroxy-3-methylglutaryl-CoA reductase inhibitors, a class of cholesterol-lowering drugs, could interrupt Ang II signaling independent of cholesterol lowering in endothelial cells.

Phencyclidine impairs latent learning in mice: interaction between glutamatergic systems and sigma(1) receptors

The effect of phencyclidine (PCP) on latent learning was investigated using a one-trial water-finding task in mice. Mice without water deprivation were given PCP or saline before a training trial, which consisted of exposure to a novel open-field environment with an alcove containing a water tube. Twenty to twenty-four hours after water deprivation, animals were placed in the same apparatus and the time required to find the water tube measured (test trial). Saline-treated trained mice showed a significantly shorter time to find the water tube during the test trial (finding latency) than naive mice that had not been trained. When PCP (1mg/kg i.p.) was administered before the training trial, the finding latency was significantly prolonged in comparison with that in the saline-treated mice, indicating that PCP induced impairment of latent learning. 1-(3,4-Dimethoxy-phenethyl)-4-(3-phenylpropyl)piperazine dihydrochloride (SA4503: 0.3 mg/kg s.c.) and (+)-pentazocine (1 mg/kg s.c.), selective sigma(1) receptor agonists, or D-cycloserine (10 and 30mg/kg, s.c.), a glycine binding site agonist, significantly counteracted the PCP-induced impairment of latent learning, whereas (+)-SKF-10,047 (0.1-3 mg/kg s.c.), a putative sigma(1) receptor agonist, did not. The ameliorating effects of SA4503 and (+)-pentazocine were antagonized by N,N-dipropyl-2-(4-methoxy-3-(2-phenylethoxy) phenyl) ethylamine (NE-100: 1 mg/kg i.p.), a selective sigma(1) receptor antagonist. SA4503 also ameliorated the impairment of latent learning induced by dizocilpine, a non-competitive N-methyl-D-aspartate receptor antagonist, the effect being antagonized by NE-100. These results suggest that PCP induces an impairment of latent learning, this effect being mediated via glutamatergic systems, and that activation of sigma(1) receptors ameliorates impairment of latent learning induced by PCP.

Gray matter of the bovine cervical spinal cord is mechanically more rigid and fragile than the white matter

The gray matter of the cervical spinal cord has been thought to be equally or less rigid than the white matter. Based on this assumption, various studies have been conducted on the changes of stress distributions within the spinal cord under mechanical compression, although the mechanical properties of the white and gray matters had not been fully elucidated. The present study measured the mechanical properties of the white and gray matter of bovine spinal cords. For both the white and gray matter, the stress-strain curves had a nonlinear region, followed by a linear region, and then a region where the stresses plateaued before failure. In the nonlinear region, stress was not significantly different between the gray and white matter samples (strain approximately 0-10%), while stress and Young's modulus in the gray matter was significantly higher than the white matter in the linear part of the curve. The gray matter ruptured at lower strains than the white matter. These findings demonstrated the gray matter is more rigid and fragile than the white matter, and the conventional assumption (i.e., the white matter is more rigid than the gray matter) is not correct. We then applied our data to computer simulations using the finite element method, and confirmed that simulations agreed with actual magnetic resonance imaging findings of the spinal cord under compression. In future computer simulations, including finite element method using our data, changes in stress and strain within the cervical spinal cord under compression would be clarified in more detail, and our findings would also help to elucidate the area which can easily receive histologic damage or which could have hemodynamic disorders under mechanical compression, as well as severity and location of biochemical and molecular biological changes.

[Identification of microbial subtypes from antibiotic susceptibility data in clinical laboratory for nosocomial infection surveillance]

We developed an algorism to identify microbial subtypes automatically from daily antibiotic susceptibility data in clinical microbiology laboratory. The susceptibility pattern was expressed as a string of digits, each consisting of 0(resistant), 1(intermediate) or 2(susceptible) to respective antibiotics. Any two patterns were regarded identical and combined if the difference at each digit never exceeds 1. The combined pattern was expressed as an array of digit-by-digit weighted averages of the two. The second combination was based on a degree of similarity among the numerical patterns using a formula, which was designed to emphasize differences in highly variable elements. This subgrouping procedure was done every three months. Identity of the detected subtypes between the intervals was determined using the same algorism as for the second combination. The algorism was applied to data of clinical isolates of MRSA, Pseudomonas aeruginosa (PA), Klebsiella pneumoniae (KP), Enterococcus faecalis (EF), Streptococcus pneumoniae (SP), Escherichia coli (EC) that were obtained over a period of 4 years. Three major subtypes of MRSA, KP and EF were consistently detected with shifting mutual frequencies. Most of EC isolates belonged to two consistent subtypes. Although PA and SP had one or two consistent subtypes, there were multiple minor subtypes of varying frequencies. This analysis is regarded as an "infotyping", in contrast to serotype or genotype, of clinical microbial isolates, which is useful for nosocomial infection surveillance.

The prognostic value of quality-of-life scores: preliminary results of an analysis of patients with breast cancer

This study was conducted to elucidate the prognostic value of patient-assessed quality-of-life (QL) scores in cancer patients. QL was assessed in 47 consecutive patients with advanced or end-stage breast cancer using the Quality of Life Questionnaire for Cancer Patients Treated with Anticancer Drugs (QOL-ACD). The data collected from 19 of the 47 patients, who completed QL questionnaires more than twice before dying of cancer, were analyzed. The relationships between the QL scores and subsequent survival were examined at two assessment points, being the first and last assessment points of each of the 19 patients; corresponding respectively to median survival times of 14 and 4 months. The prognostic significance of the changes in QL scores that occurred over 3 months before the last assessment point was also examined. At the last assessment point, the scores of the physical aspects of QL were significantly related to survival. The change in scores of both overall QL and the physical aspects of QL were also significant predictors of survival. On the other hand, neither the scores nor the change in scores of the psychological and social aspects of QL was significant. This study indicates that both QL scores and changes in QL scores are promising prognostic predictors.

Antioxidative effect of fluvastatin, an inhibitor of 3-hydroxy-3-methylglutaryl coenzyme A reductase, on peroxidation of phospholipid liposomes

The antioxidative effect of fluvastatin sodium (fluvastatin), a 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitor, on lipid peroxidation of phosphatidylcholine (PC) liposomes was investigated in various peroxidizing systems. Fluvastatin markedly inhibited the formation of thiobarbituric acid reactive substances in iron (II)-supported peroxidation of liposomes (IC50 = 1.2 x 10(-5) M). The order of magnitude of inhibition of each drug on the peroxidation was: butylated hydroxytoluene > fluvastatin > or = probucol >> pravastatin. Moreover, concentrations of fluvastatin ranging from 1 x 10(-6) to 1 x 10(-4) M inhibited peroxyl radical-mediated peroxidation of liposomes induced by water-soluble and lipid-soluble radical generators, 2,2'-azobis (2-amidinopropane) dihydro-chloride and 2,2'-azobis (2,4-dimethylvaleronitrile), respectively. However, pravastatin showed no effect against peroxyl radical-mediated peroxidation. These results indicate that fluvastatin acted non-enzymatically as an effective inhibitor against lipid peroxidation of PC liposomes and that the antioxidative effects of fluvastatin may be due to the scavenging action of fluvastatin on liposomal lipid peroxidation induced by peroxyl radicals generated in the aqueous and lipid phases.

[Establishment of a reference interval for highly sensitive CRP by exclusion of individuals with abnormal values in related laboratory tests]

In November, 1999, U.S. Food and Drug Administration approved a highly sensitive CRP(hs-CRP) assay that could assist medical doctors to predict the risk of cardiovascular accidents. Many doctors are now interested in the assay and trying to elucidate the relationship between serum CRP levels and cardiovascular diseases. In the past, it was difficult to establish a valid reference interval of serum CRP because of the poor analytical sensitivity and difficulty in sampling reference individuals. We have established a reference interval of serum CRP for the hs-CRP assay(Dade Behring). The study population consisted of 7,224 individuals(21-81 years old) who received a regular medical check-up. Potentially abnormal samples were excluded, depending on the results of other laboratory tests related to serum CRP variation. The upper limit of the reference interval was 0.15 mg/dl. The serum CRP was higher in smokers than in non-smokers, especially in men.

[A case of central nervous system anomalies (agenesis of corpus callosum, colpocephaly, hydrocephalus, congenital dermal sinus) associated with congenital heart disease(double-outlet right ventricle, complete endocardial cushion defect, atrial septal defect, pulmonary arterial stenosis, patent ductus arteriosus)]

A case of central nervous system anomalies(agenesis of corpus callosum, colpocephaly, hydrocephalus, congenital dermal sinus) associated with congenital heart disease(double-outlet right ventricle, complete endocardial cushion defect, atrial septal defect, pulmonary arterial stenosis, patent ductus arteriosus) is reported. Female patient had been already diagnosed as hydrocephalus during pregnancy and ventricular drainage was performed soon after the delivery. Prostaglandin E 1 was also applied for heart disease, but saturation of O2 decreased to 80% on arterial blood gas analysis. Blalock-Taussig operation and ligation of ductus arteriosus was done 41 days after the delivery and ventricle-peritoneal shunt was also made for the progressive hydrocephalus on the same day. Chromosome analysis showed no abnormality. The genesis of this complicated brain and heart anomaly is discussed from the viewpoint of neural crest cell abnormality.

[Nosocomial infection monitoring system featuring detection of local clustering]

We have developed a nosocomial infection surveillance system making use of data from laboratory information system. The system makes cross-reference table of detected bacteria according to either the site of occurrence(hospital wards) or antibiotic sensitivity. It is capable of listing all the patients or serial changes in frequency for any specified bacterium. Furthermore, we have developed an algorism to detect local clustering. For each ward, the system calculates all combinations of distance between beds of patients with specified bacteria. We named the statistics as DC(degree of cluster) and its significance was judged by a confidence interval of DC obtained by a bootstrap method by randomly assigning the same number of patients to the beds in the same wards. Retrospective analysis of the distribution of 4 major bacteria in the wards proved that DC is a sensitive indicator of local clustering.

Radical scavenging properties of novel benzopyran derivatives, TA248 and TA276, and effects of the compounds on ischemic/reperfused myocardium in dogs

Characteristics of novel benzopyran derivatives, TA248 and TA276, and their effects on myocardial contraction in ischemic/reperfused hearts in dogs were examined. TA248 and TA276 inhibited NADPH-dependent lipid peroxidation induced by Fe(3+) in the rat brain homogenate. Both compounds reduced *O(2-) produced by xanthine-xanthine oxidase system in a dose-dependent manner. TA276 scavenged.OH generated by Fenton reaction in a dose-dependent manner. TA248 also inhibited the.OH production, but the effect was neither complete nor dose dependent. Myocardial contraction was assessed as segment shortening of the left ventricular wall in pentobarbital-anesthetized open-chest dogs. The segment shortening was decreased by the left anterior descending coronary artery ligation (ischemia) and returned by release of the ligated artery (reperfusion). The segment shortening did not recover fully during reperfusion. Either TA248 or TA276 injected 10 min before ischemia improved the recovery of myocardial contraction during reperfusion. Both compounds preserved the level of ATP in the 60-min reperfused myocardium. However, the level of lipid peroxides was not changed by TA248 and TA276. TA248 and TA276 may protect myocardium against ischemic/reperfusion insult, partly because of their free radical scavenging activity, but no significant change in myocardial lipid peroxide level was observed.

Unique heme environment at the putative distal region of hydrogen peroxide-dependent fatty acid alpha-hydroxylase from Sphingomonas paucimobilis (peroxygenase P450(SPalpha)

Fatty acid alpha-hydroxylase from Sphingomonas paucimobilis is a hydrogen peroxide-dependent cytochrome P450 (P450) enzyme (P450(SPalpha)). In this study, heme-ligand exchange reactions of P450(SPalpha) were investigated using the optical spectroscopic method and compared with those of various P450s. Alkylamines (C >/= 5) induced changes in the spectrum of ferric P450(SPalpha) to one typical of a nitrogenous ligand-bound low-spin form of ferric P450, although their affinities were lower than those for other P450s, and a substrate, laurate, did not interfere with the binding in contrast with in the cases of other P450s. Other compounds having a nitrogen donor atom to the heme iron of P450, including pyridine or 1-methylimidazole, induced no change in the spectrum of P450(SPalpha) in either the ferric or ferrous state. Practically no spectral change was observed on the addition of alkyl isocyanides to ferric P450s. On the other hand, cyanide induced a change in the spectrum of ferric P450(SPalpha) to one characteristic of cyanide-bound form of ferric P450. The affinity of cyanide increased when the substrate was added, in contrast with in the cases of other P450s. Ferrous P450(SPalpha) combined with CO and alkyl isocyanides, and the affinity for CO was of the same order of magnitude as in the cases of other P450s. These findings suggest a unique heme environment of P450(SPalpha), in which most compounds usually acting as external ligands of ferric P450s are prevented from gaining access to the heme iron of P450(SPalpha). The unique properties of the hydroxylase reaction catalyzed by P450(SPalpha), where an oxygen atom of hydrogen peroxide but not of molecular oxygen is utilized and incorporated into a fatty acid at its alpha position, is possibly related with such a specific heme environment of this P450. A possible mechanism for the peroxygenase reaction of P450(SPalpha) is proposed.

[Exploratory analysis of elevated C-reactive protein without leukocytosis from the clinical laboratory database]

We studied the characteristics of admitted patients who showed discrepancy between C-reactive protein(CRP) and white blood cell count(WBC). We extracted those patients from our laboratory information system by two criteria: WBC is less than 9500/microliter and either(1) CRP is more than 5.0 mg/dl, or(2) the pair of CRP and WBC is out of 95% confidence ellipse. We found 346 and 90 cases by the two criteria, respectively. They consisted of a variety of diseases, prevalent were such as pneumonia, rheumatoid arthritis, malignant lymphoma, post-operative state and so on by either criterion. There was predominance of elderly patients as a whole. The analysis of individual time courses revealed that WBC did not change in parallel with CRP in patients with rheumatoid arthritis and malignant lymphoma, while they paralleled in those with infectious diseases and post-operation states. The elevation of WBC in some patients might have been overlooked since WBC was not always to be ordered together with CRP. We need a prospective study to closely analyze serial relationship between CRP and WBC for factors leading to the discovery.

Fatty acid-specific, regiospecific, and stereospecific hydroxylation by cytochrome P450 (CYP152B1) from Sphingomonas paucimobilis: substrate structure required for alpha-hydroxylation

Fatty acid alpha-hydroxylase from Sphingomonas paucimobilis is an unusual cytochrome P450 enzyme that hydroxylates the alpha-carbon of fatty acids in the presence of H2O2. Herein, we describe our investigation concerning the utilization of various substrates and the optical configuration of the alpha-hydroxyl product using a recombinant form of this enzyme. This enzyme can metabolize saturated fatty acids with carbon chain lengths of more than 10. The Km value for pentadecanoic acid (C15) was the smallest among the saturated fatty acids tested (C10-C18) and that for myristic acid (C14) showed similar enzyme kinetics to those seen for C15. As shorter or longer carbon chain lengths were used, Km values increased. The turnover numbers for fatty acids with carbon chain lengths of more than 11 were of the same order of magnitude (10(3) min(-1)), but the turnover number for undecanoic acid (C11) was less. Dicarboxylic fatty acids and methyl myristate were not metabolized, but monomethyl hexadecanedioate and omega-hydroxypalmitic acid were metabolized, though with lower turnover values. Arachidonic acid was a good substrate, comparable to C14 or C15. The metabolite of arachidonic acid was only alpha-hydroxyarachidonic acid. Alkanes, fatty alcohols, and fatty aldehydes were not utilized as substrates. Analysis of the optical configurations of the alpha-hydroxylated products demonstrated that the products were S-enantiomers (more than 98% enantiomerically pure). These results suggested that this P450 enzyme is strictly responsible for fatty acids and catalyzes highly stereo- and regioselective hydroxylation, where structure of omega-carbon and carboxyl carbon as well as carbon chain length of fatty acids are important for substrate-enzyme interaction.

Lipophilic HMG-CoA reductase inhibitors increase myocardial stunning in dogs

Pretreatment of dogs with simvastatin, a lipophilic 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase inhibitor, increases myocardial contractile dysfunction during reperfusion after ischemia (stunning), with reduction of tissue adenosine triphosphate (ATP). This was thought to be a consequence of prevention of ubiquinone biosynthesis by the lipophilic inhibitor in the myocardial cell. We examined whether other lipophilic HMG-CoA reductase inhibitors also influence myocardial stunning in dogs. Vehicle, atorvastatin (2 mg/ kg/day), fluvastatin (4 mg/kg/day), or cerivastatin (40 microg/kg/ day) was orally administered for 3 weeks. Hydrophilic pravastatin (4 mg/kg/day) also was given. After 3 weeks, pentobarbital-anesthetized dogs were subjected to 15-min left anterior descending coronary artery occlusion followed by 2-h reperfusion. Myocardial segment function was determined by sonomicrometry. Tissue levels of ATP were determined in 2-h reperfused hearts. All inhibitors significantly decreased serum cholesterol level. The three lipophilic inhibitors resulted in a worsening of segment function in the reperfused myocardium, as compared with the vehicle group. The levels of ATP in the atorvastatin, fluvastatin, and cerivastatin groups were significantly lower than that in the vehicle group. These results confirm that lipophilic HMG-CoA reductase inhibitors enhance myocardial stunning in association with ATP reduction after ischemia and reperfusion.

Decision-tree sensitivity analysis for cost-effectiveness of chest 2-fluoro-2-D-[(18)F]fluorodeoxyglucose positron emission tomography in patients with pulmonary nodules (non-small cell lung carcinoma) in Japan

CONTEXT

Recent studies have demonstrated the potential cost-effectiveness of using 2-fluoro-2-D-[(18)F]fluorodeoxyglucose (FDG) positron emission tomography (PET) in the management of non-small cell lung carcinoma (NSCLC), but because of differences in health-care systems, those findings may not hold true in a Japanese hospital.

OBJECTIVE

To assess the cost-effectiveness of the chest CT plus chest FDG-PET strategy in Japan.

DESIGN

Decision-tree sensitivity analysis based on the two competing strategies of chest CT-alone vs chest CT plus chest FDG-PET.

STUDY SELECTION

A simulation of 1,000 patients in whom NSCLC, stage IIIB or less, was suspected was created using baselines of other relevant variables in regard to sensitivity, specificity, mortality, life expectancy, and cost from published data.

METHODS

We surveyed the relevant literature for the choice of variables.

MAIN OUTCOME MEASURES

Expected marginal cost and expected life expectancy gain for NSCLC patients.

RESULTS

The chest CT plus chest FDG-PET strategy yielded an expected life expectancy gain of 0.607 years (7.3 months) per patient, compared with the alternative strategy of chest CT-alone. Using an FDG-PET examination cost of 1.0 x 10(5) yen (around $700 US) per study, the cost increment was 2.18 x 10(5) yen/yr/patient.

CONCLUSIONS

The chest CT plus chest FDG-PET strategy in patients with NSCLC is unlikely to be cost-effective in Japan. However, patient life expectancy gain would increase as a result of improved staging of NSCLC. These preliminary results should be confirmed by further studies for specific environments.

Cell surface expression of immature H glycoprotein in measles virus-infected cells

Two forms of hemagglutinin (H) protein, one with an apparent molecular mass of 78 kDa (78K H protein) and the other with that of 74 kDa (74K H protein), are present in cells infected with measles virus (MV). We previously observed that only the mature 78K H protein, a completely glycosylated form of the 74K H protein, was expressed on the cell surface of the infected cells. In the present study, we detected transient expression of the 74K H protein on the cell surface of infected cells by pulse-chase studies, although the level of this expression was much lower than that of the 78K H protein. On the cell surface the 74K H protein was present as dimers and sensitive to endo-beta-N-acetylglucosaminidase H digestion. Treatment with brefeldin A, which blocks the transport of membrane and secretory proteins from the endoplasmic reticulum to the Golgi apparatus, inhibited the cell surface expression of the 78K H protein, but not that of the 74K H protein. These data suggest that a part of the MV 74K H proteins could be transported directly to the cell surface - probably via an alternative pathway - without processing to the complex form in the Golgi apparatus.

Effects of pimobendan and EGIS 9377, cardiotonic agents, and OG-VI, a nucleoside-nucleotide mixture, administered during reperfusion after ischemia on stunned myocardium in dogs

BACKGROUND

Pimobendan is a so-called calcium sensitizer that exerts a positive inotropic action. EGIS 9377 is synthesized as a calcium sensitizer. OG-VI is a nucleoside-nucleotide mixture that ameliorates the myocardial dysfunction (myocardial stunning) after ischemia.

OBJECTIVE

To determine whether administration of these agents after the onset of reperfusion after ischemia improves the condition of stunned myocardium.

METHODS

Dogs anesthetized with pentobarbital were subjected to 20 min ligation of left anterior descending coronary artery and then 60 min reperfusion. The corresponding vehicle, 0.3 and 1 mg/kg pimobendan, or 1 and 3 mg/kg EGIS 9377 was injected intravenously 30 min after the onset of reperfusion. Saline solution or 1.2 mumol/kg per min OG-VI was infused for 30 min, starting 30 min after the reperfusion. Shortening of myocardial segment was measured by sonomicrometry. The tissue levels of energy and carbohydrate metabolites in the 60 min-reperfused hearts were determined.

RESULTS

Shortening of myocardial segments significantly decreased during ischemia, and returned toward preischemic level after reperfusion for all groups, although the contractile dysfunction still remained. Injections and infusion of pimobendan, EGIS 9377, and OG-VI after the onset of reperfusion ameliorated the contractile dysfunction. Systemic vascular resistance was decreased by administrations of pimobendan and OG-VI. The levels of high-energy phosphates in 60 min-reperfused heart were not changed by either treatment.

CONCLUSION

Administration of pimobendan, EGIS 9377, and OG-VI ameliorate the myocardial contractile dysfunction after ischemia even when these agents are administered after the onset of reperfusion. The increase in contractile function due to these agents did not worsen the myocardial energy balance.

Excitatory amino acid release in the locus coeruleus during naloxone-precipitated morphine withdrawal in adjuvant arthritic rats

OBJECTIVE AND DESIGN

Excitatory amino acid levels in the locus coeruleus (LC) and the behavioral signs during naloxone-precipitated withdrawal in arthritic rats treated with chronic morphine were investigated by in vivo microdialysis.

METHODS

Increases in glutamate (Glu) and aspartate (Asp) were noted after naloxone (48 nmol/5 microl, LC)-precipitated withdrawal from normal and adjuvant arthritic rats which had been intracerebroventricularly infused for 3 days with morphine (26 nmol/l microl/h).

RESULTS

The increases in Glu and Asp levels on morphine withdrawal in normal rats were attenuated following naloxone challenge in the morphine-dependent arthritic rats. Moreover, behavioral signs during morphine withdrawal were detected following the naloxone challenge in both the morphine-dependent normal and adjuvant arthritic rats, but not in the saline-infused controls.

CONCLUSIONS

These results show that the attenuation of Glu and Asp release from the LC in the adjuvant arthritic rats might explain the anti-inflammatory and analgesic effects of mu-opioids in adjuvant arthritic rats.

Translocation of G-protein beta3 subunit from the cytosol pool to the membrane pool by beta1-adrenergic receptor stimulation in perfused rat hearts

To elucidate the intracellular function and localization of the heterotrimeric G-protein beta3 subunit (Gbeta3) in the heart, we studied the effects of subtype-specific beta-adrenergic receptor (beta-AR) stimulation on Gbeta3 localization using isoform-specific antibodies. The amount of Gbeta3 in the cytosol dramatically decreased in hearts perfused with isoproterenol (ISO) alone or ISO with ICI 118551, a beta2-AR antagonist. Propranolol or CGP 20712A, a beta1-AR antagonist, blocked the ISO-induced decrease in the Gbeta3 content of the cytosol. In contrast, Gbeta3 content of the membrane fraction significantly increased in hearts perfused with ISO alone or ISO with ICI 118551. We conclude that stimulation of the beta1-AR induces isoform-specific translocation of Gbeta3 from the cytosol to the membrane fraction in rat hearts.

Participation of angiotensin II and bradykinin in contractile function in dog stunned myocardium

We examined the effects of enalapril and 4'-[(1, 4'-dimethyl-2'-propyl-[2,6'-bi-1H-enzimidazole]-1'-yl)methyl]-[1, 1'-biphenyl]-2-carboxylic acid (BIBR-277), an angiotensin II receptor antagonist, on contractile dysfunction in the stunned myocardium. Dogs were subjected to 20-min ligation of the coronary artery, followed by 60-min reperfusion. Saline, enalapril (1 mg/kg or 3 mg/kg), or BIBR-277 (3 mg/kg) was injected i.v. 10 min before ligation. D-Arginyl-L-arginlyl-L-prolyl-trans-4-hydroxy-L-prolylglycyl -3-(2-thi enyl)-L-alanyl-L-seryl-D-1,2,3, 4-tetrahydro-3-isoquinolinecarbonyl-L-(2alpha, 3beta, 7abeta)-octahydro-1H-indole-2-carbonyl-L-arginine (Hoe-140), a bradykinin B(2) receptor antagonist, at 300 microg/kg was injected i. v. 10 min before drug injection. Contractile function was assessed on the basis of percentage segment shortening (%SS). ATP levels were measured in 60-min reperfused hearts. %SS significantly decreased during ischemia, and recovered during reperfusion, although the %SS was significantly less than the pre-ischemic level. Both enalapril at either dose and BIBR-277 significantly enhanced %SS recovery during reperfusion, an effect which was associated with a tendency toward energy preservation. Hoe-140 completely abolished the effect of enalapril at either dose, while it did not modify that of BIBR-277. Inhibition of angiotensin II formation and bradykinin breakdown may be separately related to the improvement of myocardial stunning.

[Are all HMG-CoA reductase inhibitors protective against ischemic heart disease?]

Effects of pravastatin, simvastatin, atorvastatin, fluvastatin and cerivastatin on myocardial contractile dysfunction during reperfusion after brief ischemia were examined in dogs. Pretreatment of the dog with lipophilic HMG-CoA reductase inhibitors for 3 weeks, simvastatin (2 mg/kg/day), atorvastatin (2 mg/kg/day), fluvastatin (4 mg/kg/day), and cerivastatin (40 micrograms/kg/day) worsened recovery of myocardial contraction during reperfusion after brief ischemia in association with reduced myocardial ATP level. A hydrophilic HMG-CoA reductase inhibitor, pravastatin (2 and 4 mg/kg/day), did not affect the recovery of myocardial contractile function and ATP level during reperfusion following ischemia. The lipophilic inhibitors may enter the myocardial cell, inhibit ubiquinone biosynthesis, and depress ATP generation in mitochondria, leading to worsening of the myocardial stunning after reperfusion subsequent to ischemia.

Evaluation of cases with silicosis using the parameters related to Fas-mediated apoptosis

To establish a new clinical index for immunological abnormalities occurring in silicosis, several clinical parameters related to Fas-mediated apoptosis; i.e., membrane Fas expression on peripheral blood lymphocytes (mFas), serum soluble Fas levels (sFas), serum soluble Fas ligand levels (sFasL), and soluble/membrane Fas mRNA expression ratios (s/mFas ExR) in peripheral blood mononuclear cells (PBMC) were investigated. Fifty-eight silicosis patients with no clinical symptoms of autoimmune diseases were the subjects of this study. Factor analysis was performed using 12 clinical parameters including four parameters related to Fas-mediated apoptosis. Two common factors were identified. Factor 1 which consisted of the following parameters; duration of exposure, symptomatic dyspnea, PO2, PCO2, and A-aDO2, should be designated as the respiratory factor for cases with silicosis. The parameters of factor 2 were serum IgG, sFas with high factor loading, titer of ANA, sFasL, and s/mFas ExR. These parameters of factor 2 are indicative of the immunological disorders occurring in silicosis cases. Some cases exhibited abnormalities in parameters of factor 2 but not factor 1. The factor analysis clearly demonstrated that the parameters related to Fas-mediated apoptosis should be the most beneficial for predicting the pre-clinical status of complicated autoimmune diseases in silicosis.

[Acquisition of evidence and facts for a consulting service in the department of clinical laboratory to support effective usage of laboratory tests]

We are developing an integrated laboratory information database to share the evidences and facts with clinicians for effective application of diagnostic laboratory tests for the care of individual patients. It includes high quality evidence acquired from the clinical trials and systematic reviews as well as basic information about the analytical method, related disorders and so on of each laboratory test. We should also have the skills to appropriately obtain information from articles about relevant subjects and obtain the original facts from the laboratory database combined with the database from the department of medical records to review diagnostic data of individual cases. These strategies to acquire and accumulate those kinds of knowledge and information are essential for the management of a consulting service room as part of the clinical laboratory department. We must contribute to the improvement of clinical diagnoses and treatments, and serve as professional consultants with the expertise.

[Dynamic generation of diagnostic knowledge from a database of well defined case clinical records]

To promote an evidence-based practice of laboratory medicine, we created a database of 1584 typical case records consisting of 30 common diseases. Cases without therapy or major complication were carefully selected. Characteristic clinical symptoms and signs indicating the severity were recorded together with general laboratory test results. A user-friendly computer system for interpretive laboratory diagnosis was also created. It features (1) automatic graphics for visualizing distributions of laboratory values and/or prevalence of clinical symptoms and signs, (2) simultaneous display of distributions of common test values for any combination of diseases, (3) quick subclassification of cases within a disease group by any clinical characteristic, (4) diagnostic guidance by dynamic calculation of a novel similarity index that represents matching of a given set of signs/values with those of typical cases in the database.