Gamma-Ray Observation of the Cygnus Region in the 100-TeV Energy Region

We report observations of gamma-ray emissions with energies in the 100-TeV energy region from the Cygnus region in our Galaxy. Two sources are significantly detected in the directions of the Cygnus OB1 and OB2 associations. Based on their positional coincidences, we associate one with a pulsar PSR J2032+4127 and the other mainly with a pulsar wind nebula PWN G75.2+0.1, with the pulsar moving away from its original birthplace situated around the centroid of the observed gamma-ray emission. This work would stimulate further studies of particle acceleration mechanisms at these gamma-ray sources.

First Detection of sub-PeV Diffuse Gamma Rays from the Galactic Disk: Evidence for Ubiquitous Galactic Cosmic Rays beyond PeV Energies

We report, for the first time, the long-awaited detection of diffuse gamma rays with energies between 100 TeV and 1 PeV in the Galactic disk. Particularly, all gamma rays above 398 TeV are observed apart from known TeV gamma-ray sources and compatible with expectations from the hadronic emission scenario in which gamma rays originate from the decay of π^{0}'s produced through the interaction of protons with the interstellar medium in the Galaxy. This is strong evidence that cosmic rays are accelerated beyond PeV energies in our Galaxy and spread over the Galactic disk.

First Detection of Photons with Energy beyond 100 TeV from an Astrophysical Source

We report on the highest energy photons from the Crab Nebula observed by the Tibet air shower array with the underground water-Cherenkov-type muon detector array. Based on the criterion of a muon number measured in an air shower, we successfully suppress 99.92% of the cosmic-ray background events with energies E>100  TeV. As a result, we observed 24 photonlike events with E>100  TeV against 5.5 background events, which corresponds to a 5.6σ statistical significance. This is the first detection of photons with E>100  TeV from an astrophysical source.

The cosmic ray energy spectrum measured with the new Tibet hybrid experiment

We have upgraded the new Tibet ASgamma experiment in China since 2014 to measure the chemical composition of cosmic rays around the knee. This hybrid experiment consist of an air-shower-core detector array (YAC-II) to detect high energy electromagnetic component, the Tibet air-shower array (Tibet-III) and a large underground water-Cherenkov muon-detector array (MD). We have carried out a detailed air-shower Monte Carlo (MC) simulation to study the performance of the hybrid detectors by using CORSIKA (version 7.5000), which includes EPOS-LHC, QGSJETII-04, SIBYLL2.1 and SIBYLL2.3 hadronic interaction models. The preliminary results of the interaction model checking above 50 TeV energy region are reported in this paper, and the primary proton and helium spectra in the energy range 50 TeV to 1015 eV was derived from YAC-I data and is smoothly connected with direct observation data at lower energies and also with our previously reported works at higher energies within statistical errors. The knee of the (P+He) spectra is located around 400 TeV. The interaction model dependence in deriving the primary (P+He) spectra is found to be small (less than 25% in absolute intensity, 10% in position of the knee), and the composition model dependence is less than 10% in absolute intensity.

Test of the hadronic interaction models SIBYLL2.3, EPOS-LHC and QGSJETII- 04 with Tibet EAS core data

A hybrid experiment has been started by the ASγ experiment at Yangbajing (4300m a.s.l.) in Tibet since May 2009, that consists of a high-energy air-shower-core array (YAC-I) and a high-density air-shower array (Tibet-III). In this paper, we report our results to check the hadronic interaction models SIBYLL2.3, SIBYLL2.1, EPOS-LHC and QGSJETII-04 in the multi-tens TeV energy region using YAC-I+Tibet-III experimental data from May 2009 through January 2010. The effective live time is calculated as 106.05 days. The results show that the description of transverse momentum, inelastic cross-section and inelasticity for the 4 hadronic interaction models is consistent with YAC-I experimental data within 15% systematic errors range in the forward region below 100 TeV. Among them, the EPOS-LHC model is the best hadronic interaction model. Furthermore, we find that the H4a composition model is the best one below the 100 TeV energy region.

On the Solar Cycle Variation of the Solar Diurnal Anisotropy of Multi-TeV Cosmic-ray Intensity Observed with the Tibet Air Shower Array

We analyze the temporal variation of the solar diurnal anisotropy of the multi-TeV cosmic-ray intensity observed with the Tibet air shower array from 2000 to 2009, covering the maximum and minimum of the 23rd solar cycle. We comfirm that a remarkable additional anisotropy component is superposed on the Compton-Getting anisotropy at 4.0 TeV, while its amplitude decreases at higher energy regions. In constrast to the additional anisotropy reported by the Matsushiro experiment at 0.6 TeV, we find the residual component measured by Tibet at multi-TeV energies is consistent with being stable, with a fairly constant amplitude of 0.041% ± 0.003% and a phase at around 07.17 ± 00.16 local solar time at 4.0 TeV. This suggests the additional anisotropy observed by the Tibet experiment could result from mechanisms unrelated to solar activities.

Evaluation of the Interplanetary Magnetic Field Strength Using the Cosmic-Ray Shadow of the Sun

We analyze the Sun's shadow observed with the Tibet-III air shower array and find that the shadow's center deviates northward (southward) from the optical solar disk center in the "away" ("toward") interplanetary magnetic field (IMF) sector. By comparing with numerical simulations based on the solar magnetic field model, we find that the average IMF strength in the away (toward) sector is 1.54±0.21_{stat}±0.20_{syst} (1.62±0.15_{stat}±0.22_{syst}) times larger than the model prediction. These demonstrate that the observed Sun's shadow is a useful tool for the quantitative evaluation of the average solar magnetic field.

TTF-1/NKX2-1 binds to DDB1 and confers replication stress resistance to lung adenocarcinomas

TTF-1, also known as NKX2-1, is a transcription factor that has indispensable roles in both lung development and physiology. We and others have reported that TTF-1 frequently exhibits high expression with increased copy number in lung adenocarcinomas, and also has a role as a lineage-survival oncogene through transcriptional activation of crucial target genes including ROR1 and LMO3. In the present study, we employed a global proteomic search for proteins that interact with TTF-1 in order to provide a more comprehensive picture of this still enigmatic lineage-survival oncogene. Our results unexpectedly revealed a function independent of its transcriptional activity, as TTF-1 was found to interact with DDB1 and block its binding to CHK1, which in turn attenuated ubiquitylation and subsequent degradation of CHK1. Furthermore, TTF-1 overexpression conferred resistance to cellular conditions under DNA replication stress (RS) and prevented an increase in consequential DNA double-strand breaks, as reflected by attenuated induction of pCHK2 and γH2AX. Our findings suggest that the novel non-transcriptional function of TTF-1 identified in this study may contribute to lung adenocarcinoma development by conferring tolerance to DNA RS, which is known to be inherently elicited by activation of various oncogenes.

Probe of the solar magnetic field using the "cosmic-ray shadow" of the sun

We report on a clear solar-cycle variation of the Sun’s shadow in the 10 TeV cosmic-ray flux observed by the Tibet air shower array during a full solar cycle from 1996 to 2009. In order to clarify the physical implications of the observed solar cycle variation, we develop numerical simulations of the Sun’s shadow, using the potential field source surface model and the current sheet source surface (CSSS) model for the coronal magnetic field. We find that the intensity deficit in the simulated Sun’s shadow is very sensitive to the coronal magnetic field structure, and the observed variation of the Sun’s shadow is better reproduced by the CSSS model. This is the first successful attempt to evaluate the coronal magnetic field models by using the Sun’s shadow observed in the TeV cosmic-ray flux.

Long-term clinical effects of epalrestat, an aldose reductase inhibitor, on progression of diabetic neuropathy and other microvascular complications: multivariate epidemiological analysis based on patient background factors and severity of diabetic neuropathy

AIMS

The goal of the study was to evaluate the efficacy of epalrestat, an aldose reductase inhibitor, on diabetic retinopathy and diabetic nephropathy, based on analysis of the results of the Aldose Reductase Inhibitor-Diabetes Complications Trial, a 3-year multicentre comparative clinical trial of conventional therapy (control group) and epalrestat therapy (epalrestat group) in Japanese patients with mild diabetic neuropathy.

METHODS

The subjects of the study were patients enrolled in the Aldose Reductase Inhibitor-Diabetes Complications Trial for whom data for major patient characteristics, severity of diabetic neuropathy at the end of the study and time-courses of diabetic retinopathy and diabetic nephropathy were available (57 and 52 patients from the control and epalrestat groups, respectively). Progression of diabetic retinopathy/nephropathy (a primary endpoint) in relation to major patient characteristics, severity of diabetic neuropathy at the end of the study (assessed from the mean of z-scores in four neurological function tests) and epalrestat treatment were analysed using univariate analysis and multiple logistic regression analysis.

RESULTS

Progression of diabetic retinopathy/nephropathy was significantly inhibited in the epalrestat group compared with the control group (odds ratio = 0.323, P = 0.014) and was dependent on the severity of diabetic neuropathy at the end of the study (odds ratio = 2.131, P = 0.025).

CONCLUSIONS

Epalrestat prevented progression of diabetic neuropathy and retinopathy/nephropathy. The effect on diabetic retinopathy/nephropathy may have occurred indirectly because of the prevention of progression of diabetic neuropathy, in addition to the inhibitory action of epalrestat on aldose reductase.

Intravenous immunoglobulin does not increase FcγRIIB expression levels on monocytes in children with immune thrombocytopenia

Intravenous immunoglobulin (IVIG) produces a rapid and prolonged increase in the platelet counts of children with immune thrombocytopenia (ITP). The mechanism of IVIG efficacy in a murine model of ITP has been reported to operate through an IVIG-mediated increase in the expression of the inhibitory Fc receptor FcγRIIB(CD32B) on splenic macrophages. This investigation examined whether IVIG administration results in a similar increase in FcγRIIB expression on peripheral blood CD14(+) monocytes in 20 children with ITP. FcγRIIB expression on peripheral blood monocytes was measured by flow cytometry in ITP patients, before and after IVIG therapy, as well as in control subjects. Peripheral blood monocytes were labelled with fluorescent-specific antibodies. There were no significant differences in the absolute number of [corrected] CD14(+) CD32B(+) monocytes, and [corrected] the percentages of CD14(+) CD32B(+) cells in mononuclear cells or monocytes. [corrected]. We suggest that IVIG does not increase FcγRIIB expression in peripheral blood monocytes in children with ITP.

Microalbuminuria is independently associated with deep or infratentorial brain microbleeds in hypertensive adults

BACKGROUND

Brain microbleeds (BMBs) detected on gradient echo T2*-weighted magnetic resonance imaging (GE-MRI) may be pathophysiologically linked to ischemic cerebral small-vessel disease (SVD) and increased risk of future hemorrhagic stroke. Chronic kidney disease (CKD) has been associated with the presence of BMBs in stroke patients. However, the relationship between CKD markers and BMBs in stroke-free populations is unknown.

METHODS

Two hundred and eighty-five hypertensive subjects (mean age 68.6 years) without neurological symptoms were enrolled from a hospital-based outpatient clinic and all participants underwent GE-MRI. We calculated urinary albumin/creatinine ratio (UACR) from morning spot urine and the estimated glomerular filtration rate (eGFR) in serum samples. Multivariate logistic regression analysis was used to evaluate the association between these kidney biomarkers and the presence and location of BMBs, controlling for age, sex, use of antihypertensive or antithrombotic drugs, and MRI findings.

RESULTS

BMBs were observed in 48 (16.8%) patients. Median UACRs were significantly higher in patients with deep or infratentorial BMBs than in patients with pure lobar BMBs (54 vs. 17 mg/g creatinine, P = 0.04). No significant differences were found between eGFR levels and the location of BMBs. Microalbuminuria (UACR >30- ≤300 mg/g creatinine), but not low eGFR level was significantly associated with higher prevalence of deep or infratentorial BMBs (odds ratio (OR): 3.16, 95% confidence interval (CI): 1.34-7.44, P = 0.009) even after adjustment for potential confounding factors.

CONCLUSIONS

Microalbuminuria is closely associated with the prevalence of deep or infratentorial BMBs in hypertensive patients. Our findings provide new insights into the association between risk factors and the distribution of BMBs.

Endothelial and inflammatory markers in relation to progression of ischaemic cerebral small-vessel disease and cognitive impairment: a 6-year longitudinal study in patients with type 2 diabetes mellitus

BACKGROUND

Progression of silent brain infarctions (SBIs) and white-matter lesions (WMLs) seen on brain MRI is associated with an increased risk of cognitive impairment, but their relation to endothelial and inflammatory markers is unknown in type 2 diabetes mellitus.

METHODS

In 190 type 2 diabetic outpatients (mean age 62.7 years), the authors related baseline levels of soluble intercellular adhesion molecule-1 (sICAM-1) and high-sensitivity C-reactive protein (hs-CRP) to subsequent brain MRI findings and cognitive function. The authors assessed incident SBIs and changes in periventricular and subcortical WMLs (PVWMLs and SCWMLs) on MRI performed at baseline and 3 and 6 years. Neuropsychological tests were administered to 83 patients older than 65 years at 6 years. This present study represents an extension of the authors' previously published study.

RESULTS

SBIs were observed in 46 patients (24.2%), PVWMLs in 93 (48.9%) and SCWMLs in 87 (45.8%) on baseline MRI. After adjustment for age, gender, hypertension, duration of diabetes, baseline MRI findings and medication use, the relative odds associated with a 1SD increase in sICAM-1 levels at baseline were 1.67 (95% CI 1.02 to 3.05) for SBI progression and 2.17 (95% CI 1.29 to 3.62) for PVWML progression at 6 years. In contrast, baseline hs-CRP levels were significantly associated with SBI progression only at 3 years. Significant trends were observed between quartiles of sICAM-1 at baseline and scores in Digit Symbol substitution (p for trend=0.01).

CONCLUSIONS

The findings suggest that higher sICAM-1 levels are associated with SBI and PVWML progression, and may predict impairment in psychomotor function in type 2 diabetes.

The adaptive responses in several mediators linked with hypertrophy and atrophy of skeletal muscle after lower limb unloading in humans

AIM

To determine the adaptive changes in several molecules regulating muscle hypertrophy and atrophy after unloading, we examined whether unilateral lower limb suspension changes the mRNA and protein levels of SRF-linked (RhoA, RhoGDI, STARS and SRF), myostatin-linked (myostatin, Smad2, Smad3 and FLRG) and Foxo-linked (P-Akt, Foxo1, Foxo3a and Atrogin-1) mediators.

METHODS

A single lower limb of each of eight healthy men was suspended for 20 days. Biopsy specimens were obtained from the vastus lateralis muscle pre- and post-suspension.

RESULTS

The volume of the vastus lateralis muscle was significantly decreased after unloading. The amount of RhoA, RhoGDI or SRF protein in the muscle was not significantly changed post-suspension. An RT-PCR semiquantitative analysis showed increased levels of myostatin mRNA but not Smad2, Smad3 or FLRG mRNA. Unloading did not elicit significant changes in the amount of p-Smad3 or myostatin protein in the muscle. The amount of p-Akt protein was markedly reduced in the unloaded muscle. Lower limb SUSPENSION DID NOT INFLUENCE THE EXPRESSION PATTERN OF FOXO1, FOXO3A OR ATROGIN-1.

CONCLUSION

Unloading inducing a mild degree of muscle atrophy may decrease p-Akt and increase myostatin but not SRF-linked mediators.

Stratified analyses for selecting appropriate target patients with diabetic peripheral neuropathy for long-term treatment with an aldose reductase inhibitor, epalrestat

AIMS

The long-term efficacy of epalrestat, an aldose reductase inhibitor, in improving subjective symptoms and nerve function was comprehensively assessed to identify patients with diabetic peripheral neuropathy who responded to epalrestat treatment.

METHODS

Stratified analyses were conducted on data from patients in the Aldose Reductase Inhibitor-Diabetes Complications Trial (ADCT). The ADCT included patients with diabetic peripheral neuropathy, median motor nerve conduction velocity > or = 40 m/s and with glycated haemoglobin (HbA(1c)) < or = 9.0%. Longitudinal data on HbA(1c) and subjective symptoms of the patients for 3 years were analysed (epalrestat n = 231, control subjects n = 273). Stratified analyses based on background variables (glycaemic control, grades of retinopathy or proteinuria) were performed to examine the relationship between subjective symptoms and nerve function. Multiple logistic regression analyses were conducted.

RESULTS

Stratified subgroup analyses revealed significantly better efficacy of epalrestat in patients with good glycaemic control and less severe diabetic complications. In the control group, no improvement in nerve function was seen regardless of whether symptomatic benefit was obtained. In the epalrestat group, nerve function deteriorated less or improved in patients whose symptoms improved. The odds ratio of the efficacy of epalrestat vs. control subjects was approximately 2 : 1 (4 : 1 in patients with HbA(1c) < or = 7.0%).

CONCLUSION

Our results suggest that epalrestat, an aldose reductase inhibitor, will provide a clinically significant means of preventing and treating diabetic neuropathy if used in appropriate patients.

Influence of work rate on dynamics of O2 uptake under hypoxic conditions in humans

AIM

It was the purpose of the investigation to determine whether an altered work rate could influence the oxygen uptake (V.O(2)) and heart rate (HR) dynamics at hypoxia and normoxia.

METHODS

Ten males performed a cycle exercise with 2 repetitions of 6 min each at a constant work load while breathing one of two inspiratory O(2) fractions (FIO(2)): 0.12 (moderate hypoxia) and 0.21 (normoxia). Each test began with unloaded pedaling. This was followed by three constant loads, which were 40%, 60%, and 80% of the subject's gas exchange threshold (GET) in hypoxia (F(I)O(2) = 0.12), with the 80% GET load repeated under normoxia (room air). V.O(2) was measured on a breath-by-breath basis and beat-by-beat HR via ECG, and the half time (t1/2) of each parameter was established, following interpolation data.

RESULTS

There were no remarkable differences in t1/2 V.O(2) dynamics among the 40%, 60% and 80% GET; however, the differences became significant at hypoxia compared with normoxia. The HR dynamics were significantly faster in normoxia compared with hypoxia, independent of work rates. During steady-state exercise, the alterations in HR and cardiac output (Q) using the acetylene rebreathing method depended on increases in the work rate, and a significantly increase in at 80% GET was observed when compared with normoxia. Increases of stroke volume (SV) were unaffected by altered work rates and inspired O(2) concentrations. The arteriovenous oxygen difference (Ca-vO(2)) at a steady-state of exercise increased proportionally with the work rate under hypoxia, and a much greater Ca-vO(2) was observed during normoxic exercise than under hypoxia.

CONCLUSION

These results seem to suggest that in humans, O(2) uptake dynamics are affected by lower O(2), not by changing work rates at hypoxia, to which the interaction between lower O(2) utilization in exercising muscles and hypoxic-induced greater blood flow can be attributed.

Intermittent hypoxia does not increase exercise ventilation at simulated moderate altitude

Recent human studies have shown that resting hypoxic ventilatory response (HVR), which is an index of ventilatory chemosensitivity to hypoxia, increased after short-term intermittent hypoxia at rest. In addition, intermittent hypoxia leads to increases in ventilation and arterial oxygen saturation (SaO (2)) during exercise at simulated high altitude, with the increase in ventilation correlated to the change in HVR. However, no study has been made to clarify the relationship between ventilatory chemosensitivity and the exercise ventilation at moderate altitude following intermittent hypoxia during a resting state. The purpose of the present study, therefore, was to elucidate whether intermittent hypoxia at rest induces the increase in ventilation during exercise at moderate altitude that is accompanied by an increase in hypoxic chemosensitivity. Eighteen trained male runners were assigned to three groups, i.e., the first hypoxic group (H-1 group, n = 6), the second hypoxic group (H-2 group, n = 6), and a control group (C group, n = 6). The hypoxic tent system was utilized for intermittent hypoxia, and the oxygen levels in the tent were maintained at 15.5 +/- 0.1 % (simulated 2500 m altitude) for the H-1 group and 12.3 +/- 0.2 % (simulated 4300 m altitude) for the H-2 group. The H-1 and H-2 groups spent 1 hour per day in the hypoxic tent for 1 week. Maximal and submaximal exercise tests while breathing 15.5 +/- 0.01 % O (2) (simulated altitude of 2500 m) were performed before and after intermittent hypoxia. Resting HVR was also determined in each subject using a progressive isocapnic hypoxic method. In the H-2 group, HVR increased significantly (p < 0.05) following intermittent hypoxia, while no change in HVR was found in the H-1 or C group. Neither ventilation nor SaO (2) during maximal and submaximal exercise at a simulated altitude of 2500 m were changed in either group after 1 hour per day for 1 week of intermittent hypoxia. These results suggest that the change in resting hypoxic chemosensitivity after short-term intermittent hypoxia does not affect ventilation during exercise at moderate altitude.

Anisotropy and Corotation of Galactic Cosmic Rays

The intensity of Galactic cosmic rays is nearly isotropic because of the influence of magnetic fields in the Milky Way. Here, we present two-dimensional high-precision anisotropy measurement for energies from a few to several hundred teraelectronvolts (TeV), using the large data sample of the Tibet Air Shower Arrays. Besides revealing finer details of the known anisotropies, a new component of Galactic cosmic ray anisotropy in sidereal time is uncovered around the Cygnus region direction. For cosmic-ray energies up to a few hundred TeV, all components of anisotropies fade away, showing a corotation of Galactic cosmic rays with the local Galactic magnetic environment. These results have broad implications for a comprehensive understanding of cosmic rays, supernovae, magnetic fields, and heliospheric and Galactic dynamic environments.

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.

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.

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.

Observation by an air-shower array in Tibet of the multi-TeV cosmic-ray anisotropy due to terrestrial orbital motion around the Sun

We report on the solar diurnal variation of the galactic cosmic-ray intensity observed by the Tibet III air shower array during the period from 1999 to 2003. In the higher-energy event samples (12 and 6.2 TeV), the variations are fairly consistent with the Compton-Getting anisotropy due to the terrestrial orbital motion around the Sun, while the variation in the lower-energy event sample (4.0 TeV) is inconsistent with this anisotropy. This suggests an additional anisotropy superposed at the multi-TeV energies, e.g., the solar modulation effect. This is the highest-precision measurement of the Compton-Getting anisotropy ever made.

Characteristic patterns of circadian variation in plasma catecholamine levels, blood pressure and heart rate variability in Type 2 diabetic patients

AIMS

To investigate whether Type 2 diabetic patients exhibit characteristic patterns of circadian variation in plasma levels of catecholamines, blood pressure (BP) and heart rate variability (HRV).

METHODS

Ten Type 2 diabetic and eight control in-patients were studied. Blood for catecholamine measurement was collected every 4 h, and non-invasive ambulatory BP and heart rate were monitored throughout the day. HRV was determined using frequency domain methods.

RESULTS

Diabetic patients showed a different pattern of circadian variation in BP and HRV from that of controls, the diurnal-nocturnal differences (D-N) being significantly smaller. The mean 24-h HRV levels were reduced in diabetic subjects. The mean 24-h plasma noradrenaline level of 1.36 +/- 0.12 nmol/l in diabetic patients was significantly lower than the 2.03 +/- 0.20 nmol/l in controls (P < 0.01). In contrast, no significant difference in adrenaline levels was observed. The mean 24-h plasma noradrenaline level demonstrated a significant positive correlation with D-N in systolic BP (r = 0.49, P = 0.0153).

CONCLUSIONS

The present study demonstrated distinctive patterns of circadian variation in plasma noradrenaline level, BP and HRV in Type 2 diabetic patients, associated with an abnormal circadian pattern of sympathovagal modulation.

Magnetic resonance imaging findings in schizophrenia and atypical psychoses

The differences among MRI findings were studied in schizophrenic psychoses. The schizophrenics and atypical psychotics had significant reductions in bilateral hippocampal volumes compared to controls, but the two patient groups did not differ from each other. As for ventricle volume, the schizophrenics showed significantly larger temporal horns and third ventricle than normal controls, whereas atypical psychotics did not. Moreover, the left temporal horn in the schizophrenics was significantly larger than that seen in the atypical psychotics. By cluster analysis, schizophrenics and atypical psychotics were found to have a tendency to be distributed in different groups. These results might be considered to support the classification of schizophrenic psychoses into schizophrenia and atypical psychoses.

The effect of cigarette smoking on soluble adhesion molecules in middle-aged patients with Type 2 diabetes mellitus

AIMS

To investigate the effect of smoking on soluble adhesion molecules in middle-aged diabetic patients.

METHODS

One hundred out-patients with Type 2 diabetes and 100 age- and sex-matched non-diabetic subjects without clinical macrovascular disease were selected. Soluble serum levels of adhesion molecules were analysed using enzyme immunoassay. Carotid atherosclerosis was assessed using an ultrasound system.

RESULTS

When compared with non-diabetic subjects, soluble vascular cell adhesion molecule-1 (sVCAM-1), soluble intercellular adhesion molecule-1 (sICAM-1), and sE-selectin were found at significantly high levels in diabetic patients and significantly higher levels of sICAM-1, sE-selectin, and sP-selectin were observed in current smokers than never-smokers among diabetic or non-diabetic subjects, respectively. The combined, but not enhanced, effects of diabetes mellitus and smoking were observed in sICAM-1 and sE-selectin levels. Additionally, levels of sICAM-1 (P < 0.05) and sE-selectin (P < 0.01), but not sP-selectin, were high in ex-smokers when compared with never-smokers among diabetic patients. Diabetic smokers were also found to have marked carotid atherosclerosis, which was related to increased levels of sICAM-1.

CONCLUSIONS

Our present study shows that levels of adhesion molecules were higher in diabetic smokers than diabetic non-smokers or non-diabetic smokers, and that cessation after chronic smoking did not restore the levels of sICAM-1 and sE-selectin, though sP-selectin levels were restored. These data suggest a possible mechanism for accelerated atherosclerosis induced by smoking in patients with diabetes.

[Clinical difference between thiazolidinediones and biguanides]

Hyperglycemia in patients with type 2 diabetes mellitus is caused by peripheral insulin resistance, which results in decreased insulin-mediated glucose disposal and increased endogenous glucose production, and inadequate insulin secretion. Recently, either biguanides or thiazolidinediones among oral hypoglycemic agents is widely used to patients with type 2 diabetes mellitus for reversal of insulin resistance. As clinical difference between biguanides and thiazolidinediones in reducing blood glucose, the former primarily lowers endogenous glucose production presumably at the level of liver, whereas the latter increases insulin-mediated peripheral glucose disposal, which occurs predominantly in skeletal muscle. Therefore, combination therapy with these two drugs results in further improvement in glucose control. Combination therapy including these two drugs is attractive prospects in future treatment for patients with type 2 diabetes.

Clinical efficacy of fidarestat, a novel aldose reductase inhibitor, for diabetic peripheral neuropathy: a 52-week multicenter placebo-controlled double-blind parallel group study

OBJECTIVE

The purpose of this study was to evaluate the efficacy of fidarestat, a novel aldose reductase (AR) inhibitor, in a double-blind placebo controlled study in patients with type 1 and type 2 diabetes and associated peripheral neuropathy.

RESEARCH DESIGN AND METHODS

A total of 279 patients with diabetic neuropathy were treated with placebo or fidarestat at a daily dose of 1 mg for 52 weeks. The efficacy evaluation was based on change in electrophysiological measurements of median and tibial motor nerve conduction velocity, F-wave minimum latency, F-wave conduction velocity (FCV), and median sensory nerve conduction velocity (forearm and distal), as well as an assessment of subjective symptoms.

RESULTS

Over the course of the study, five of the eight electrophysiological measures assessed showed significant improvement from baseline in the fidarestat-treated group, whereas no measure showed significant deterioration. In contrast, in the placebo group, no electrophysiological measure was improved, and one measure significantly deteriorated (i.e., median nerve FCV). At the study conclusion, the fidarestat-treated group was significantly improved compared with the placebo group in two electrophysiological measures (i.e., median nerve FCV and minimal latency). Subjective symptoms (including numbness, spontaneous pain, sensation of rigidity, paresthesia in the sole upon walking, heaviness in the foot, and hypesthesia) benefited from fidarestat treatment, and all were significantly improved in the treated versus placebo group at the study conclusion. At the dose used, fidarestat was well tolerated, with an adverse event profile that did not significantly differ from that seen in the placebo group.

CONCLUSIONS

The effects of fidarestat-treatment on nerve conduction and the subjective symptoms of diabetic neuropathy provide evidence that this treatment alters the progression of diabetic neuropathy.

Midkine is involved in neutrophil infiltration into the tubulointerstitium in ischemic renal injury

Midkine (MK) is a multifunctional heparin-binding protein and promotes migration of neutrophils, macrophages, and neurons. In the normal mouse kidney, MK is expressed in the proximal tubules. After renal ischemic reperfusion injury, its expression in proximal tubules was increased. Immediate increase of MK expression was found when renal proximal tubular epithelial cells in culture were exposed to 5 mM H(2)O(2). Histologically defined tubulointerstitial damage was less severe in MK-deficient (Mdk(-/-)) than in wild-type (Mdk(+/+)) mice at 2 and 7 days after ischemic reperfusion injury. Within 2 days after ischemic injury, inflammatory leukocytes, of which neutrophils were the major population, were recruited to the tubulointerstitium. The numbers of infiltrating neutrophils and also macrophages were lower in Mdk(-/-) than in Mdk(+/+) mice. Induction of macrophage inflammatory protein-2 and macrophage chemotactic protein-1, chemokines for neutrophils and macrophages, respectively, were also suppressed in Mdk(-/-) mice. Furthermore, renal tubular epithelial cells in culture expressed macrophage inflammatory protein-2 in response to exogenous MK administration. These results suggested that MK enhances migration of inflammatory cells upon ischemic injury of the kidney directly and also through induction of chemokines, and contributes to the augmentation of ischemic tissue damage.

Cardiorespiratory response to low-intensity walking in water and on land in elderly women

The purpose of the present study was to determine whether or not the exercise intensity of water-walking for elderly women could be accurately prescribed by heart rate data obtained during treadmill exercise on land. Six healthy female volunteers, with a mean age of 62.2 +/- 4.2 years, took part in this study. Walking on land was performed on a treadmill. Each subject completed three consecutive 4-minute walks at a progressively increasing velocity (40, 60 and 80 m.min-1), with a 1-minute rest after both the first and second walks. The room temperature and relative humidity were 24.5 +/- 0.2 degrees C and 54.8 +/- 4.0%, respectively. Walking in water was performed in a Flowmill, which is a treadmill positioned at the base of a water flume. Each subject completed three consecutive 4-minute walks at a progressively increasing belt and water-flow velocity (20, 30 and 40 m.min-1), with a 1-minute rest after both the first and second walks. The water depth was at the level of the xiphoid process of each subject. The water temperature was 30.7 +/- 0.1 degrees C. The exercise intensity at the highest workrate was equivalent to 44.2 +/- 10.3% of the heart rate reserve (HRR) during water-walking and 38.4 +/- 4.7% of the HRR during land-walking. There was a highly significant linear relationship between heart rate (HR) and oxygen uptake (VO2) during both water-walking and land-walking. The relationship between HR and VO2 in both exercise modes was similar. Thus, the relationship of HR to VO2 derived from a treadmill-graded walking test on land may be used to prescribe exercise intensity for water-walking in thermoneutral water.

Effects of a new synthetic selectin blocker in an acute rat thrombotic glomerulonephritis

In an attempt to explore a novel therapeutic approach, a new synthetic sulfatide derivative (SKK60037) was evaluated in an acute rat model of P-selectin and leukocyte-dependent thrombotic glomerulonephritis (TG). In vitro, SKK60037 inhibits the function of P- and L-selectin more effectively than sialyl Lewis X (sLe(x)), a well-established selectin blocker. TG was induced by the intravenous administration of nephrotoxic globulin (NTG) to rats pretreated with a subclinical dose of lipopolysaccharide. In this model, platelet accumulation was remarkable within 10 minutes after induction of disease, followed by the infiltration of leukocytes, mainly neutrophils and macrophages. Thrombus formation and fibrinogen deposition in the glomeruli were observed within 1 hour, and they proceeded until 6 hours. P-selectin was highly expressed in glomeruli, whereas E-selectin and L-selectin ligands were not detected. We tested the effects of SKK60037 in this model in comparison with sLe(x) and antirat P-selectin monoclonal antibody (ARP2-4). SKK60037 blocked platelet accumulation in glomerular capillaries at 10 minutes after NTG injection. At 6 hours, leukocyte infiltration and thrombosis were significantly suppressed. Protective effects of SKK60037 were similar to those of ARP2-4, whereas sLe(x) showed minimum effect. The superior effects and more favorable characteristics of SKK60037 to sLe(x) suggest the potential of SKK60037 for clinical application.

Aldose reductase inhibition ameliorates pupillary light reflex and F-wave latency in patients with mild diabetic neuropathy

OBJECTIVE

The present study was conducted to investigate the effect of an aldose reductase inhibitor, epalrestat, on autonomic and somatic neuropathy at an early stage in type 2 diabetic patients by assessing the pupillary light reflex and minimum latency of the F-wave.

RESEARCH DESIGN AND METHODS

A total of 30 diabetic patients with subclinical or mild diabetic neuropathy were randomly allocated to a control group (n = 15) and epalrestat (150 mg/day) group (n = 15). After 24 weeks, the pupillary light reflex test, cardiovascular autonomic function tests, and nerve conduction study were performed.

RESULTS

The beneficial effect of epalrestat on the pupillary light reflex was observed in the minimum diameter after light stimuli (P = 0.044), constriction ratio (P = 0.014), and maximum velocity of constriction (P = 0.008). Among cardiovascular autonomic nerve functions, the ratio of the longest expiratory R-R interval to the shortest inspiratory R-R interval during deep breathing was significantly improved by epalrestat (P = 0.037). Minimum latencies of F-wave of median and tibial motor nerves were significantly shortened by epalrestat (P = 0.002 and P = 0.001, respectively); however, no significant effects were observed in motor or sensory nerve conduction velocity.

CONCLUSIONS

These observations suggest that epalrestat may have therapeutic value at the early stage of diabetic neuropathy and that the pupillary light reflex and minimum latency of F-wave may be useful indicators of diabetic neuropathy.

Lipid peroxidation may predict restenosis after coronary balloon angioplasty

The present study assessed whether lipid peroxidation in plasma might predict restenosis after coronary balloon angioplasty. A total of 87 patients, who had undergone successful coronary balloon angioplasty using standard techniques, were enrolled. Fasting blood samples before the intervention were measured for plasma levels of thiobarbituric acid reactive substances (TBARS, an indicator of lipid peroxidation). Angiography was carried out before and 15 min after angioplasty, and at follow-up (4 months after angioplasty), and evaluated using a quantitative approach. There were 23 patients with restenosis (group R) and 64 patients without restenosis (group N) after coronary balloon angioplasty. The plasma TBARS level (mean+/-SEM) of 4.3+/-0.1 micromol/L in group R was significantly higher than that of 3.2+/-0.1 micromol/L in group N (p<0.01). There were no significant differences in other parameters, including plasma lipid levels, between the 2 groups. The plasma level of TBARS positively correlated with lumen loss of the coronary artery at the time of follow-up angiography (r=0.57, p<0.01). Our results suggest that oxidative stress contributes to restenosis and indicate that an elevated plasma level of TBARS may be a reliable predictor of restenosis.

The role of C5a in the development of thrombotic glomerulonephritis in rats

Thrombus formation is the important pathologic finding observed in glomerulonephritis induced by antiglomerular basement membrane (GBM) antibodies. Although strong deposition of C3 and membrane attack complex (MAC) is observed in this disease, the role of complement has not been fully elucidated. The aim of this work was to investigate the role of complement, especially an anaphylatoxin C5a, in a rat model of thrombotic glomerulonephritis. Rats were first pretreated with subclinical dose of lipopolysaccharide (LPS). Thrombotic glomerulonephritis was then induced by intravenous injection with rabbit antirat GBM (RbAGBM) (Group I). For the evaluation of the role of complement, the soluble complement receptor type 1 (sCR1) (Group II) or the C5a receptor antagonist peptide (C5aR-AP) (Group III) was intravenously administered 30 min before RbAGBM injection. For exploring the role of neutrophils, rats were pretreated with cyclophosphamide before induction of disease (Group IV). All rats were sacrificed at 6 h, and histological examination was performed. Rats in Group I developed severe glomerular thrombosis. Leucocyte accumulation and strong binding of C3 and MAC were observed in the glomeruli. In rats treated with sCR1 (Group II) and C5aR-AP (Group III), both leucocyte accumulation and thrombus formation in the glomeruli were significantly inhibited. C3 and MAC were negative in the glomeruli in Group II rats, while they were strongly observed in Group III. In neutrophil depleted rats (Group IV), there was also deposition of C3 and MAC in the glomeruli but thrombus formation was not observed. These findings indicated that glomerular thrombosis is dependent on the leucocytes, and mediated in part by the anaphylatoxin C5a but not MAC in the present model.

[Clinical study on the cases in which INH or RFP was discontinued during treatment for pulmonary tuberculosis]

Short course regimens; 2HRZ (E)(S)/4HR (E), 6HRS (E)/3-6HR and 6-9HR have been accepted as a standard chemotherapy (SC) for initial treatment of pulmonary tuberculosis in Japan. We studied the frequency of the treatment completion, the causes of the treatment failure and the outcome of the patients in whom INH or RFP was discontinued within 6 months after starting SC. The subjects included 597 newly diagnosed culture positive pulmonary tuberculosis patients admitted to 16 national hospital in 1996. Results were as follows. 1. In 47 (7.9%) of the 597 patients, either INH (19; 3.2%) or RFP (33; 5.5%) was discontinued. These 47 cases were defined as a SC incompleted group and the other 550 as a SC completed group. 2. The patients in the SC incompleted group were seen more frequently in the ages of 20s (11.9%), 50s (10.9%), 60s (11.7%) or 70s (11.4%). 21 (13.6%) of 154 female patients and 26 (5.9%) of 443 male patients were in the SC incompleted group. 3. The causes of cessation of INH or RFP were drug side effects (33; 5.5%), drug resistance (10; 1.7%) and complications or underlying diseases (8; 1.3%). 4. Fever or eruption (19; 3.2%) and drug induced hepatitis (12; 2.0%) were frequently seen as drug related side effects causing the cessation of INH or RFP. 5. The rate of culture negative conversion of TB bacilli at 6 months after the start of the treatment was 98.9% in the SC completed and 88.9% in the SC incompleted group respectively. In the SC incompleted group, there were three cases continuously positive and two other patients who relapsed and became culture positive again. In these five patients, INH or RFP was discontinued because of drug resistance.

Thermoregulatory responses to low-intensity prolonged swimming in water at various temperatures and treadmill walking on land

The purpose of the present study was to examine the effect of water temperature on the human body during low-intensity prolonged swimming. Six male college swimmers participated in this study. The experiments consisted of breast stroke swimming for 120 minutes in 23 degrees C, 28 degrees C and 33 degrees C water at a constant speed of 0.4 m.sec-1 in a swimming flume. The same subjects walked on a treadmill at a rate of approximately 50% of maximal oxygen uptake (VO2max) at the same relative intensity as the three swimming trials. Rectal temperature (Tre) in 33 degrees C water was unchanged during swimming for 120 minutes. Tre during treadmill walking increased significantly compared to the three different swimming trials. Tre, mean skin temperature (Tsk) and mean body temperature (Tb) in 23 degrees C and 28 degrees C water decreased significantly more than in both the 33 degrees C water and walking on land. VO2 during swimming in 23 degrees C water increased more than during swimming in the 28 degrees C and 33 degrees C trials; however, there were no significant differences in VO2 between the 23 degrees C swimming trial and treadmill walking. Heart rate (HR) during treadmill walking on land increased significantly compared with HR during the three swimming trials. Plasma adrenaline concentration at the end of the treadmill walking was higher than that at the end of each of the three swimming trials. Noradrenaline concentrations at the end of swimming in the 23 degrees C water and treadmill walking were higher than those during the other two swimming trials. Blood lactate concentration during swimming in 23 degrees C water was higher than that during the other two swimming trials and walking on land. These results suggest that the balance of heat loss and heat production is maintained in the warm water temperature. Therefore, a relatively warm water temperature may be desirable when prolonged swimming or other water exercise is performed at low intensity.

Glucose-induced hyperproliferation of cultured rat aortic smooth muscle cells through polyol pathway hyperactivity

AIMS/HYPOTHESIS

The protein kinase C (PKC), platelet-derived growth factor (PDGF) and polyol pathway play important parts in the hyperproliferation of smooth muscle cells, a characteristic feature of diabetic macroangiopathy. The precise mechanism, however, remains unclear. This study investigated the relation between polyol pathway, protein kinase C and platelet-derived growth factor in the development of diabetic macroangiopathy.

METHODS

Smooth muscle cells were cultured with 5.5 or 20 mmol/l glucose with or without an aldose reductase inhibitor, epalrestat, or a PKC-beta specific inhibitor, LY333531. Protein kinase C activities, the expression of PKC-beta II isoform and PDGF-beta receptor protein, free cytosolic NAD+:NADH ratio, the contents of reduced glutathione, and proliferation activities were measured.

RESULTS

Smooth muscle cells cultured with 20 mmol/l glucose showed statistically significant increases in protein kinase C activities, the expression of PKC-beta II isoform and PDGF-beta receptor protein, and proliferation activities, compared with smooth muscle cells cultured with 5.5 mmol/l glucose. Although epalrestat and LY333531 inhibited protein kinase C activation induced by glucose to the same degree, the effects of epalrestat on proliferation activities and expression of the PDGF-beta receptor were more prominent than those of LY333531. Epalrestat improved the glucose-induced decrease in free cytosolic NAD+:NADH ratio and reduced glutathione content, but LY333531 did not. The increased expression of membranous PKC-beta II isoform was normalized by epalrestat.

CONCLUSION/INTERPRETATION

These observations suggest that polyol pathway hyperactivity contributes to the development of diabetic macroangiopathy through protein kinase C, PDGF-beta receptor, and oxidative stress, and that an aldose reductase inhibitor has a therapeutic value for this complication.

Molecular cloning and partial characterization of rat procarboxypeptidase R and carboxypeptidase N

Carboxypeptidase R (EC 3.4.17.20) (CPR) and carboxypeptidase N (EC 3.4.17.3) (CPN) cleave carboxy-terminal arginine or lysine residues from biologically active peptides such as kinins or anaphylatoxins in the circulation thereby regulating their activities. Although CPN is present in a stable active form in plasma, CPR is generated from proCPR, a plasma zymogen, by proteolytic enzymes such as thrombin, thrombin-thrombomodulin complex and plasmin. We have isolated rat proCPR and CPN cDNA clones which can induce enzymatic activities in culture supernatants of the transfected cells. mRNA of proCPR was detected only in rat liver by Northern hybridization and showed hepatocyte-specific expression. Expression of proCPR mRNA was enhanced following LPS injection, indicating that proCPR production is increased under inflammatory conditions.

Physiological responses to water-walking in middle aged women

The purpose of the present study was to examine the physiological responses to water-walking using the Flowmill, which has a treadmill at the base of a water-flume, in two groups of women. In the first group, the women were known to regularly swim and exercise in water (group A), while in the second, they did not routinely participate in water-exercise (group B). In both groups, twelve healthy female volunteers in their fifties participated in the study. All of the subjects walked in water using the Flowmill for the first time. Subjects completed four consecutive bouts of 4-minute duration at progressively increasing speeds (20, 30, 40, and 50 m.min-1), with 1-minute rests between each bout. In addition, water-velocity was adjusted to the walking speed of each bout. The water-depth of the Flowmill was the level of the xiphoid process. The water and room temperatures were 30.3 +/- 0.1 degrees C and 24.9 +/- 0.4 degrees C, respectively. In both groups, the relationship between walking speed and oxygen uptake (VO2) as well as that between walking speed and heart rate (HR) changed exponentially as the walking speed increased, and the relationship between HR and VO2 was linear. The relationship between HR and VO2 was similar in both groups, and there was no significant difference between the predicted maximal oxygen uptake (VO2max) of the two groups. VO2 and HR of group B during water-walking, however, were significantly higher than those of group A at all walking speeds. The results of this study clearly showed that experience in moving through the water strongly affects physiological responses to water-exercise, even when fitness levels are equivalent.

Role of PKC and TGF-beta receptor in glucose-induced proliferation of smooth muscle cells

The role of protein kinase C (PKC) and transforming growth factor (TGF)-beta in the proliferation of vascular smooth muscle cells (SMCs) under a high glucose condition was investigated. [3H]-thymidine incorporation under 20 mM glucose was significantly accelerated compared with that under 5.5 mM glucose, and this increase was inhibited by an anti-TGF-beta antibody or a PKC-beta specific inhibitor, LY333531. The amount of active and total TGF-beta1 in the conditioned media did not differ between 5.5 and 20 mM glucose. However, the expression of TGF-beta receptor type II under 20 mM glucose was significantly increased, but that of the TGF-beta receptor type I was not. This increased expression of the TGF-beta receptor type II was prevented by LY333531. These observations suggest that the increased expression of the TGF-beta receptor type II via PKC-beta plays an important role in the accelerated proliferation of SMCs under a high glucose condition, leading to the development of diabetic macroangiopathy.

Spectrophotometric analysis of 5-coordinate cobalt(II) species for ligand substitution of hexakis(acetonitrile)cobalt(II) with bulky 1,1,3,3-tetramethylurea in noncoordinating nitromethane

The ligand substitution reaction of [Co(an)6]2+ (an = acetonitrile) with 1,1,3,3-tetramethylurea (TMU) in the noncoordinating solvent, nitromethane, was spectrophotometrically investigated by titration. The observed spectral changes were analyzed using a model with the four steps of ligand substitution. The component complexes involved in the substitution were found to be 6-coordinate [Co(an)6]2+ and [Co(an)5(tmu)]2+, 5-coordinate [Co(an)3(tmu)2]2+ and [Co(an)2(tmu)3]2+, and 4-coordinate [Co(tmu)4]2+. The logarithmic values of the stepwise equilibrium constant are 2.17 +/- 0.26, 1.06 +/- 0.15, 1.19 +/- 0.06, and -0.4 +/- 0.4 at 25 degrees C. The decrease in the coordination number of the Co(II) ion from 6 to 5 during the formation of [Co(an)3(tmu)2]2+ and from 5 to 4 during the formation of [Co(tmu)4]2+ is ascribed to the steric repulsion between the coordinating bulky TMU molecules.