Subcutaneous Infusion of DNA-Aptamer Raised against Advanced Glycation End Products Prevents Loss of Skeletal Muscle Mass and Strength in Accelerated-Aging Mice

We have developed DNA aptamers that can inhibit the toxic effects of advanced glycation end products (AGE-Apts). We herein evaluated the effects of AGE-Apts on muscle mass and strength in senescence-accelerated mouse prone 8 (SAMP8) mice. Eight-month-old male SAMP8 mice received subcutaneous infusion of control DNA aptamers (CTR-Apts) or AGE-Apts. Mice in an age-matched senescence-accelerated mouse resistant strain 1 (SAMR1) group were treated with CTR-Apts as controls. The soleus muscles were collected after the 8-week intervention for weight measurement and histological, RT-PCR, and immunofluorescence analyses. Grip strength was measured before and after the 8-week intervention. AGE-Apt treatment inhibited the progressive decrease in the grip strength of SAMP8 mice. SAMP8 mice had lower soleus muscle weight and fiber size than SAMR1 mice, which was partly restored by AGE-Apt treatment. Furthermore, AGE-Apt-treated SAMP8 mice had a lower interstitial fibrosis area of the soleus muscle than CTR-Apt-treated SAMP8 mice. The soleus muscle levels of AGEs, oxidative stress, receptor for AGEs, and muscle ring-finger protein-1 were increased in the CTR-Apt-treated mice, all of which, except for AGEs, were inhibited by AGE-Apt treatment. Our present findings suggest that the subcutaneous delivery of AGE-Apts may be a novel therapeutic strategy for aging-related decrease in skeletal muscle mass and strength.

Luseogliflozin inhibits high glucose-induced TGF-2 expression in mouse cardiomyocytes by suppressing NHE-1 activity

Objective

Sodium-glucose cotransporter-2 (SGLT2) inhibitors exhibit cardioprotective properties in patients with diabetes. However, SGLT2 is not expressed in the heart, and the underlying molecular mechanisms are not fully understood. We investigated whether the SGLT2 inhibitor luseogliflozin exerts beneficial effects on high glucose-exposed cardiomyocytes via the suppression of sodium-hydrogen exchanger-1 (NHE-1) activity.

Methods

Mouse cardiomyocytes were incubated under normal or high glucose conditions with vehicle, luseogliflozin, or the NHE-1 inhibitor cariporide. NHE-1 activity and gene expression were evaluated by the SNARF assay and real-time reverse transcription-polymerase chain reaction (RT-PCR) analysis, respectively. Six-week-old male db/db mice were treated with vehicle or luseogliflozin for 6 weeks, and the hearts were collected for histological, RT-PCR, and western blot analyses.

Results

High glucose increased NHE-1 activity and transforming growth factor (Tgf)-β2 mRNA levels in cardiomyocytes, both of which were inhibited by luseogliflozin or cariporide, whereas their combination showed no additive suppression of Tgf-β2 mRNA levels. Luseogliflozin attenuated cardiac hypertrophy and fibrosis in db/db mice in association with decreased mRNA and protein levels of TGF-β2.

Conclusions

Luseogliflozin may suppress cardiac hypertrophy in diabetes by reducing Tgf-β2 expression in cardiomyocytes via the suppression of NHE-1 activity.

Ovarian Development and Larval Release of the Hermit Crab Clibanarius eurysternus (Hilgendorf, 1879) (Decapoda: Anomura: Diogenidae) in Okinawa, Japan

This study investigated ovarian development and larval release in the hermit crab Clibanarius eurysternus, which inhabits the upper intertidal zone on Okinawa, Japan. Adult females were collected monthly and had a high gonadosomatic index (GSI) from May to October. Oocytes at vitellogenic stages were observed from May to October. Some females had post-ovulatory follicles in the ovary and embryos on the abdomen (ovigerous females) in June and August, suggesting active ovarian development and larval release during these months (breeding season). When adult females were collected weekly according to the lunar cycle, a high GSI with oocytes at the tertiary yolk globule stage in the ovaries was maintained in all lunar phases. Since post-ovulated follicles were seen in ovaries collected around the last quarter and new moons, darkness at night is needed for spawning. Ovigerous females exposed to stepwise changes in hydrostatic pressure exhibited significantly higher synchrony between larval release and high pressure at night from the last quarter moon to the new moon, suggesting the importance of the tidal amplitude cycle in larval release under non-moonlight conditions. We concluded that the continuity of synchronous spawning and larval release of C. eurysternus are repeated under darkness and high tide at night during the breeding season.

Regulating size of silver nanoparticles on calcium carbonate via ultrasonic spray for effective antibacterial efficacy and sustained release

Calcium carbonate is used as bone-filling material due to its good biocompatibility, bioactivity, and bioabsorbability, but the prevalence of infectious complications associated with calcium carbonate has created a persisting challenge in the treatment of bone defect. Therefore, this greatly necessitate the need to endow calcium carbonate with antibacterial properties. In this study, calcium carbonate powders loaded with silver nanoparticles (Ag-CaCO₃) were prepared in attempt to serve as a novel antibacterial inorganic filler material. This objective was achieved using ultrasonic spray-pyrolysis (USSP) route to produce Ag-CaCO₃ with 1, 5 and 10 mol% silver. The size of silver nanoparticles on CaCO₃ microspheres could be regulated by adjusting silver concentration to facilitate effective release of Ag⁺ ions. This was demonstrated in Ag-CaCO₃ (1), where the lowest silver content at 1 mol% achieved the highest Ag⁺ ions release over 28 days. This in turn gave rise to effective antibacterial efficiency against Staphylococcus aureus and Escherichia coli. Furthermore, CaCO₃ (1) could also support osteoblast-like cells (MG-63) at a cell viability of 80%. Overall, this work extends the capabilities in employing USSP to produce inorganic filler materials with sustained antibacterial properties, bringing one step closer to the development of antibacterial products.

Glucose Variability is Independently Correlated with Serum Level of Pigment Epithelium-Derived Factor in Type 2 Diabetes

INTRODUCTION

Pigment epithelium-derived factor (PEDF) may play a role in cardiometabolic disorders. The aim of this study was to investigate which biochemical and clinical parameters are independently associated with serum PEDF levels in patients with type 2 diabetes mellitus (T2DM).

METHODS

We performed a cross-sectional analysis of 124 patients with T2DM who underwent continuous glucose monitoring (CGM) and blood chemistry analysis, including the diacron-reactive oxygen metabolites (d-ROMs) test and serum PEDF measurement (study 1). Then we investigated whether the changes in the studied biochemical and clinical parameters after 24 weeks of treatment (Δparameters) with anti-hyperglycemic agents, including sodium-glucose cotransporter 2 inhibitors, glucagon-like peptide 1 receptor agonists, and/or insulin and anti-hypertensive drugs and statins, were independently correlated with change in PEDF (ΔPEDF) in 52 of the patients with T2DM for whom there was sufficient serum samples to perform the post-treatment analysis (study 2). Serum levels of PEDF were measured with an enzyme-linked immunosorbent assay. CGM metrics were calculated on days 2 and 3. Oxidative stress was evaluated using the d-ROMs test.

RESULTS

Body mass index (BMI), triglycerides, fasting C-peptide, mean amplitude of glycemic excursions (MAGE), urinary albumin-to-creatinine ratio (UACR), and d-ROMs were positively associated with serum PEDF level, and high-density lipoprotein cholesterol (HDL-C) and estimated glomerular filtration rate (eGFR) were inversely associated with serum PEDF level. Because these parameters were correlated with each other, multivariate stepwise analysis was performed: eGFR, HDL-C, BMI, MAGE, and UACR remained significant (R² = 0.452). Furthermore, ΔMAGE and Δd-ROMs were positively correlated with ΔPEDF in study 2.

CONCLUSIONS

The results of this study suggest that MAGE may be independently correlated with elevations in serum PEDF level in patients with T2DM.

Glucose-dependent insulinotropic polypeptide inhibits cardiac hypertrophy and fibrosis in diabetic mice via suppression of TGF-β2

Diabetic cardiomyopathy is associated with an increased risk for heart failure and death in patients with diabetes. We investigated here whether and how GIP attenuated cardiac hypertrophy and fibrosis in diabetic mice with obesity. Diabetic db/db mice at 7 weeks old were infused with vehicle or GIP (50 nmol/kg/day) for 6 weeks, and hearts were collected for histological and RT-PCR analyzes. Cardiomyocytes isolated from neonatal mice were incubated with or without 300 nM [D-Ala2]-GIP, 30 mM glucose, or 100 μg/mL advanced glycation end products (AGEs) for RT-PCR and lucigenin assays. Compared with non-diabetic mice, diabetic mice exhibited larger left ventricle wall thickness and cardiomyocyte sizes and more fibrotic areas in association with up-regulation of myosin heavy chain β (β-Mhc) and transforming growth factor-beta2 (Tgf-β2) mRNA levels, all of which were inhibited by GIP infusion. High glucose increased NADPH oxidase-driven superoxide generation and up-regulated β-Mhc, Tgf-β2, and receptor for AGEs mRNA levels in cardiomyocytes, and augmented the AGE-induced β-Mhc gene expression. [D-Ala2]-GIP attenuated all of the deleterious effects of high glucose and/or AGEs on cardiomyocytes. Our present findings suggest that GIP could inhibit cardiac hypertrophy and fibrosis in diabetic mice via suppression of TGF-β2.

A Dipeptidyl Peptidase-4 Inhibitor Inhibits Foam Cell Formation of Macrophages in Type 1 Diabetes via Suppression of CD36 and ACAT-1 Expression

Dipeptidyl peptidase-4 (DPP-4) inhibitors have been reported to play a protective role against atherosclerosis in both animal models and patients with type 2 diabetes (T2D). However, since T2D is associated with dyslipidemia, hypertension and insulin resistance, part of which are ameliorated by DPP-4 inhibitors, it remains unclear whether DPP-4 inhibitors could have anti-atherosclerotic properties directly by attenuating the harmful effects of hyperglycemia. Therefore, we examined whether a DPP-4 inhibitor, teneligliptin, could suppress oxidized low-density lipoprotein (ox-LDL) uptake, foam cell formation, CD36 and acyl-coenzyme A: cholesterol acyltransferase-1 (ACAT-1) gene expression of macrophages isolated from streptozotocin-induced type 1 diabetes (T1D) mice and T1D patients as well as advanced glycation end product (AGE)-exposed mouse peritoneal macrophages and THP-1 cells. Foam cell formation, CD36 and ACAT-1 gene expression of macrophages derived from T1D mice or patients increased compared with those from non-diabetic controls, all of which were inhibited by 10 nmol/L teneligliptin. AGEs mimicked the effects of T1D; teneligliptin attenuated all the deleterious effects of AGEs in mouse macrophages and THP-1 cells. Our present findings suggest that teneligliptin may inhibit foam cell formation of macrophages in T1D via suppression of CD36 and ACAT-1 gene expression partly by attenuating the harmful effects of AGEs.

Anti-inflammatory and atheroprotective properties of glucagon

Although glucagon has been shown to exert pleiotropic actions in various types of cells and organs through the interaction with its receptor, its pathophysiological role in atherosclerotic cardiovascular disease remains unclear. Here, we examined whether and how glucagon could attenuate the progression of atherosclerotic plaques in apolipoprotein E-deficient mice (ApoE^-/-), an animal model of atherosclerosis. Glucagon (138 or 413 nmol/kg/day) or vehicle was infused to mice at 16 weeks of age. After 4-week treatment, vascular samples were collected for histological and RT-PCR analyses. Human monocytic THP-1 cells were pre-incubated with or without a glucagon receptor antagonist L-168049, and then treated with or without glucagon for 7 h. Gene and protein expressions were determined by RT-PCR and western blot analyses, respectively. High-dose glucagon infusion significantly decreased aortic plaque area and volume in ApoE^-/- mice, both of which were inversely correlated with plasma glucagon levels. Glucagon infusion also reduced the ratio of pro-inflammatory interleukin-1β to anti-inflammatory interleukin-10 gene expression in aortae. Glucagon receptor was expressed in THP-1 cells, and 1 nM glucagon decreased the ratio of interleukin-1β to interleukin-10 gene expression, which was significantly prevented by L-168049. Our present findings suggest that glucagon could exert atheroprotection partly via its anti-inflammatory property.

Association of Hemoglobin A1c, 1,5-Anhydro-D-Glucitol and Glycated Albumin with Oxidative Stress in Type 2 Diabetes Mellitus Patients: A Cross-Sectional Study

INTRODUCTION

Oxidative stress plays a central role in the development and progression of vascular complications in patients with type 2 diabetes mellitus (T2DM). We have previously shown that markers of glucose variability evaluated by continuous glucose monitoring (CGM) are positively associated with oxidative stress in patients with T2DM. However, the evaluation of the glycemic variability by CGM remains a time- and money-consuming procedure. Therefore, this study investigated the independent correlates of oxidative stress among various other clinical markers routinely measured in primary care.

METHODS

This was a retrospective cross-sectional study with 234 T2DM patients to examine which clinical variables, including 1,5-anhydro-D-glucitol (1,5-AG) and glycated albumin (GA), were independently associated with oxidative stress. Oxidative stress was measured using the diacron-reactive oxygen metabolites (d-ROMs) test. The relationships between d-ROMs and clinical factors, such as blood glucose, glycated hemoglobin (HbA1c), 1,5-AG, GA, lipid parameters, and blood pressure, were examined.

RESULTS

Multiple stepwise regression analysis revealed that 1,5-AG (inversely), GA, triglycerides, use of metformin and being female were independently associated with d-ROMs. When patients with T2DM were stratified into two groups with HbA1c < 8.0% and HbA1c ≥ 8.0%, 1,5-AG (inversely), HbA1c, use of metformin and being female were independently associated with d-ROMs in diabetes patients with HbA1c < 8.0%, whereas GA, fasting plasma glucose and being female were independently associated with d-ROMs in patients with HbA1c ≥ 8.0%.

CONCLUSION

Our present study suggests that 1,5-AG and GA are the strongest correlates of oxidative stress in patients with well and poorly controlled T2DM, respectively.

Luseogliflozin attenuates neointimal hyperplasia after wire injury in high-fat diet-fed mice via inhibition of perivascular adipose tissue remodeling

BACKGROUND

Excess fat deposition could induce phenotypic changes of perivascular adipose tissue (PVAT remodeling), which may promote the progression of atherosclerosis via modulation of adipocytokine secretion. However, it remains unclear whether and how suppression of PVAT remodeling could attenuate vascular injury. In this study, we examined the effect of sodium-glucose cotransporter 2 (SGLT2) inhibitor, luseogliflozin on PVAT remodeling and neointima formation after wire injury in mice.

METHODS

Wilt-type mice fed with low-fat diet (LFD) or high-fat diet (HFD) received oral administration of luseogliflozin (18 mg/kg/day) or vehicle. Mice underwent bilateral femoral artery wire injury followed by unilateral removal of surrounding PVAT. After 25 days, injured femoral arteries and surrounding PVAT were analyzed.

RESULTS

In LFD-fed lean mice, neither luseogliflozin treatment or PVAT removal attenuated the intima-to-media (I/M) ratio of injured arteries. However, in HFD-fed mice, luseogliflozin or PVAT removal reduced the I/M ratio, whereas their combination showed no additive reduction. In PVAT surrounding injured femoral arteries of HFD-fed mice, luseogliflozin treatment decreased the adipocyte sizes. Furthermore, luseogliflozin reduced accumulation of macrophages expressing platelet-derived growth factor-B (PDGF-B) and increased adiponectin gene expression. Gene expression levels of Pdgf-b in PVAT were correlated with the I/M ratio.

CONCLUSIONS

Our present study suggests that luseogliflozin could attenuate neointimal hyperplasia after wire injury in HFD-fed mice partly via suppression of macrophage PDGF-B expression in PVAT. Inhibition of PVAT remodeling by luseogliflozin may be a novel therapeutic target for vascular remodeling after angioplasty.

Revascularization procedure mainly by suction thrombectomy for acute cervical carotid occlusion

SUMMARY

In many cases, the prognosis for acute cervical carotid artery occlusion is poor. However, a standard treatment for the acute stage is not yet established. We report here the results of eight consecutive patients (mean age 71.5 years old) in which revascularization mainly by suction thrombectomy was performed under proximal protection during the acute phase. The occlusion sites were the intracranial internal carotid artery in five patients, tandem lesions of the internal carotid origin and intracranial vessel in two patients, and the common carotid artery in one patient. In addition, the subjects who received the treatment had an extent of infarction in MRI/DWI that was 1/3 or less of the internal carotid artery territory. The mean time from the onset to treatment commencement was 7.25 hours (2-28 hours). For the endovascular treatment, a guiding catheter with a balloon was used for proximal protection of the carotid artery. Revascularization was performed mainly by suction thrombectomy, and if a stenosed lesion was observed, PTA/stenting was added. Local fibrinolysis was not performed in combination with the above procedure. The treatment results were complete recanalization in three patients and partial recanalization in three patients. However, recanalization was not achieved in two patients. No hyperfusion syndrome or hemorrhagic infarction was observed postoperatively. All four patients in whom thrombi were successfully aspirated had occlusions proximal to the ophthalmic artery branch. In three of these four patients, complete recanalization was achieved. The revascularization procedure using suction thrombectomy under proximal protection was considered effective against the acute cervical carotid occlusions, in particular, those proximal to the ophthalmic artery branch.

Raman Microspectroscopic Study on Polymerization and Degradation Processes of a Diacetylene Derivative at Surface Enhanced Raman Scattering Active Substrates. 1. Reaction Kinetics

Raman microspectroscopy was applied to study the polymerization kinetics of the Langmuir-Blodgett (LB) films of 10,12-pentacosadiynoic acid (DA) adsorbed on surface enhanced Raman scattering (SERS) active Ag island films. A two-dimensional (2D) Raman microscopic image measured at 1520 cm(-1) exhibits bright and dim spots with the diameter of several hundred nanometers. Raman microscopic spectra, measured by defocusing the excitation laser light (532 nm, diameter of ca. 10 mum) on the samples at room temperature, proved the occurrence of the surface processes consisting of the formation of polydiacetylene (PDA) in the blue phase, its conversion to the red phase, and subsequent bleaching. These reactions were negligible under the same condition for the DA-LB films prepared on a smooth (i.e., SERS-inactive) Ag film, indicating that the 532-nm-induced polymerization and the bleaching process are enhanced by the SERS-active substrates. At low temperatures below -50 degrees C, the Raman microscopic measurements proved the formation of the blue phase and its conversion to the red phase with much lower reaction rates compared to the corresponding rates at room temperature. The bleaching, however, was much suppressed at the low temperatures. The kinetic analyses of the formation of the blue phase and its conversion to the red phase were performed by using the intensity changes of the Raman bands due to the blue (1477 cm(-1)) and red (1517 cm(-1)) phases as a function of the irradiation time. The results strongly suggested the existence of at least two processes taking place simultaneously on the SERS-active substrates; that is, one of the processes is a sequential reaction, DA-monomers --> PDA in the blue phase --> PDA in the red phase, and the other is another sequential reaction, DA-monomers --> PDA in the red phase --> degradation species (probably amorphous carbon). Thus, even at the low temperatures, there occurs the surface reaction consisting of the formation of PDA and its degradation. The reaction can be ascribed to a process taking place at the highly SERS-active site, which gives the bright spot (so-called "hot spot") on the 2D Raman image, as proved by the confocal Raman microscopic measurement in the following paper.

Raman Microspectroscopic Study on Polymerization and Degradation Processes of a Diacetylene Derivative at Surface Enhanced Raman Scattering Active Substrates. 2. Confocal Raman Microscopic Observation of Polydiacetylene Adsorbed on Active Sites

Confocal Raman microscopic measurements were performed at room temperature on the Langmuir-Blodgett (LB) monolayer of 10,12-pentacosadiynoic acid (DA) prepared on surface enhanced Raman scattering (SERS) active Ag island films, two-dimensional (2D) Raman images of which exhibit bright and dim spots on a dark background. The measurements performed by focusing the excitation laser light (488 nm) on the dark background indicate the prompt appearance of the Raman bands (1515 and 2115 cm(-1)) due to polydiacetylene (PDA) in the red phase and subsequent diminution of the Raman bands. On the other hand, the spectra observed by focusing the excitation laser spot on the dim and bright spots exhibit almost random fluctuations, giving rather narrow Raman bands in the 1620-1000 cm(-1) region, which appear and disappear temporarily with varying intensities under the continuous irradiation at 488 nm. Broad Raman bands appear around 1580 and 1360 cm(-1), which are ascribable to amorphous carbon, at a later stage of the observation, the intensities from the bright spot being more than 100 times stronger than those from the dim spot. The narrow bands are ascribed to a series of carbonaceous intermediates such as polyenes, graphite sheets with various sizes, and folded or reorganized forms of the sheets including carbon nanotubes and fullerenes, which are formed during the conversion of PDA to amorphous carbon. The random spectral fluctuation was interpreted by considering that the intermediates undergo thermally activated diffusion and get temporarily in contact with the SERS-active site, resulting in the enhancement of their Raman bands and the fluctuation.

Eye movement control in reading unspaced text: the case of the Japanese script

The present study examines the landing-site distributions of the eyes during natural reading of Japanese script: a script that mixes three different writing systems (Kanji, Hiragana, and Katakana) and that misses regular spacing between words. The results show a clear preference of the eyes to land at the beginning rather than the center of the word. In addition, it was found that the eyes land on Kanji characters more frequently than on Hiragana or Katakana characters. Further analysis for two- and three-character words indicated that the eye's landing-site distribution differs depending on type of the characters in the word: the eyes prefer to land at the word beginning only when the initial character of the word is a Kanji character. For pure Hiragana words, the proportion of initial fixations did not differ between character positions. Thus, as already indicated by Kambe (National Institute of Japanese Language Report 85 (1986) 29), the visual distinctiveness of the three Japanese scripts plays a role in guiding eye movements in reading Japanese.

Inefficient visual search for second-order motion

Visual search rate was used to assess attentional resources required for detection of opposing motions defined either by luminance or by modulations of texture contrast, flicker, or size. Though luminance-based targets were detected quickly, search through second-order motion was slow. Control experiments ruled out stimuli visibility, complexity, eccentricity sensitivity, and attributes of the carrier as possible accounts. Results suggest separate processing of the two types of stimuli: Luminance-based motion is detected by spatiotemporal filters, whereas second-order motion is likely processed by a capacity-limited, later stage. Rate-reducing effects of increased contrast and speed mirrored previous research suggesting that effortful feature tracking may be the mechanism.

Perception of relation of stimuli locations successively flashed before saccade

Based on localization error for a single perisaccadic flash, eye position signal is supposed to change more slowly than physical eye position. Nevertheless, a flicker is not perceived as moving in accordance with localization error for a single flash. We carried out two experiments to investigate this problem. Experiment 1 examined how a single flash or a flicker presented before saccade was perceived. The results showed that the flicker was not perceived as moving, although mislocalization for the single flash increases gradually before saccade. Experiment 2 was a vernier test of two stimuli successively flashed before the saccade. The results showed that the point of subjective equality shifted in accordance with the mislocalization for a single perisaccadic flash when the interstimulus interval (ISI) was about 2 s; however, it did not shift when the ISI was 78 ms. Comparison between these results and previous studies suggests that the relation of the locations of successive flashes before saccade is perceived exocentrically when the ISI and stimulus onset asynchrony between flashes was short.

Optimal viewing position in vertically and horizontally presented Japanese words

In the present study, the optimal viewing position (OVP) phenomenon in Japanese Hiragana was investigated, with special reference to a comparison between the vertical and the horizontal meridians in the visual field. In the first experiment, word recognition scores were determined while the eyes were fixating predetermined locations in vertically and horizontally displayed words. Similar to what has been reported for Roman scripts, OVP curves, which were asymmetric with respect to the beginning of words, were observed in both conditions. However, this asymmetry was less pronounced for vertically than for horizontally displayed words. In the second experiment, the visibility of individual characters within strings was examined for the vertical and horizontal meridians. As for Roman characters, letter identification scores were better in the right than in the left visual field. However, identification scores did not differ between the upper and the lower sides of fixation along the vertical meridian. The results showed that the model proposed by Nazir, O'Regan, and Jacobs (1991) cannot entirely account for the OVP phenomenon. A model in which visual and lexical factors are combined is proposed instead.

Cortical activity related to cue-invariant shape perception in humans

We used magnetoencephalography to search spatio-temporally for cortical activity related to the perception of shape defined by various visual cues in humans. The visual stimuli were three kinds of two-dimensional figures: two had fixed shapes (Diamond and Cross), the other did not (Noise). These figures were defined by three visual cues: difference of flicker, texture or luminance between the foreground and the background in the random dot pattern. Using this stimulus, we recorded the magnetic responses from the temporo-occipital regions of nine healthy subjects. Additionally, we measured the reaction time for the subjects to detect the figure by button-pressing. A magnetic component was identified in the responses. The properties of the first magnetic component differed for stimulus condition. The peak latency of the first magnetic component was different for the cues (270 ms for flicker, 360 ms for texture and 250 ms for luminance), but not for the figures. In contrast, the peak amplitude of the first magnetic component was different for the figures (96-144 fT for Diamond or Cross and 52-80 fT for Noise), but not for the cues. The signal source of the first magnetic component was estimated to lie on the ventral side of the extrastriate cortex: In the posterior part of the inferior temporal cortex, probably in the fusiform gyrus in four subjects, and in the lateral part of the occipital cortex which was outside of the primary visual cortex (visual area 1) in one subject. The signal source location was different inter-individually, but almost the same within each subject. Reaction time was 471 ms for flicker, 569 ms for texture and 426 ms for luminance, but the interval between the reaction time and the peak latency was constant (about 200 ms) for each cue. The first magnetic component was more clearly recorded from the right hemisphere than from the left.We found that the shape defined by the different visual cues activates the same localized site in the lateral extrastriate cortex. This spatial convergence suggests that there is a restricted locus that processes the visual shape regardless of the difference of the visual cue. The correspondence between the peak latency and the reaction time suggests that the activity of the area is responsible for the perception of visual shape. The inter-hemispheric difference suggests a dominance of the right hemisphere in visual shape processing.

Asymmetry of the human visual field in magnetic response to apparent motion

Predominance of the lower visual field has been shown in various visual tasks, but whether the upper visual field is involved in a specific neural process is unknown. We used magnetoencephalography to study the effect of orientation and direction on the responses of five subjects to apparent motion from the human extrastriate cortex. The first magnetic response always was the largest, and the peak latency of about 200 ms did not change with the stimulus conditions. Amplitudes of the first responses were highest when motions were oriented at the horizontal meridian, decreasing with the degree of the angle between motion orientation and the horizontal meridian. There was no difference in amplitude between the two directions in the lower visual field, whereas the value of the response to downward motion in the upper visual field was significantly larger than that to upward motion. These amplitude changes are not due to differences in the anatomical distribution of neural activities because the estimated origins for the first responses always were in the same cortical area (around the occipito-parieto-temporal region) and the directions of the current vectors did not change with the stimulus conditions, and the estimated current strength changed with the stimulus conditions as did the response amplitude. These findings suggest that the human extrastriate cortex has a directional preference for downward versus upward motion in the upper visual field.

[Effect of concreteness of target words on verbal working memory: an evaluation using Japanese version of reading span test]

Effects of concreteness and representation mode (kanji/hiragana) of target words on working memory during reading was tested using Japanese version of reading span test (RST), developed by Osaka and Osaka (1994). Concreteness and familiarity of target words and difficulty of sentences were carefully controlled. The words with high concreteness resulted in significantly higher RST scores, which suggests the high efficiency of working memory in processing these words. The results suggest that high concrete noun-words associated with visual clues consume less working memory capacity during reading. The effect of representation mode is different between subjects with high-RST and low-RST scores. Characteristic of the high concrete words that may be responsible for the effectiveness of processing are discussed.

Individual differences in working memory and the peak alpha frequency shift on magnetoencephalography

The effect of the working memory demands on the peak alpha frequency of the power spectrum of magnetoencephalography (MEG) was investigated. There were one control condition and four listening span test (LST) conditions demanding the use of working memory. The results showed that the peak alpha frequency of the averaged MEG power shifted to the higher frequency region in the LST condition dominantly in the fronto-temporal region. Individual differences in working memory capacities were observed in the shift of peak alpha frequency of MEG.

[A study of association between lean body mass and serum insulin-like growth factor-1 in continuous ambulatory peritoneal dialysis patients]

Malnutrition is one of the major issues associated with high mortality and morbidity in chronic dialysis patients. Several methods to evaluate the nutritional status of these patients have been attempted for example anthropometric measurement and biochemical parameters. Recently, it was reported that insulin-like growth factor-1 (IGF-1) has been valuable for estimating nutritional status. In this study, we measured lean body mass (LBM) by dual energy X-ray absorptiometry (DXA), IGF-1 and other biochemical parameters in 35 patients on CAPD. Two years later, the second measurement of LBM was performed, and we assessed the percent changes of LBM and biochemical parameters. There was negative correlation between the percent changes of LBM and the duration of CAPD. In patients treated with CAPD for less than 36 months (group I) LBM increased, however, it decreased significantly in those treated for more than 36 months (group II). On the other hand, in group I there was a positive correlation between the percent changes of LBM and IGF-1. In group II there was no correlation between the percent changes of LBM and any other biochemical parameters. It could be concluded that IGF-1 is one of the predisposing factors for improving LBM of patients on CAPD for a limited duration.

Circulatory arrest with profound hypothermia during the surgical treatment of large internal carotid artery aneurysm--case report

A 43-year-old male presented with a cerebral aneurysm manifesting as right facial paresthesia, without neurological deficit. Angiography revealed a large aneurysm (22 mm) of the left internal carotid artery. Intravascular treatment using placement of a detachable coil was attempted, but the coil did not stay in the aneurysmal cavity and the procedure was abandoned. The patient did not tolerate the transient balloon occlusion test of the left internal carotid artery. Therefore, the aneurysm was clipped through an open craniotomy with profound hypothermia (20 degrees C) with cardiac arrest (24 minutes). The aneurysmal dome was collapsed, allowing easy dissection of the posterior communicating artery. The closed chest method was used during the extracorporeal cardiopulmonary bypass. Postoperative angiography revealed complete neck clipping with preservation of carotid blood flow. The patient recovered well and resumed his employment. Circulatory arrest with hypothermia provides several benefits for the surgical treatment of large and giant aneurysms.

Neuroimaging Analysis of Visual Motion

The evoked magnetic field (magnetoencephalogram: MEG) was measured in human subjects observing random-dot motion. 600 random dots generated with VSG2/3 (Cambridge Research Systems) moved at about 10 deg s−1 (either in the 45° or the 135° direction). The motion frame (5 s) was followed by a stationary frame on a screen (projected from Barcodata 3100 projection system) subtending a visual angle of about 20 deg × 20 deg. Six subjects observed the motion frame presented in the left visual field. The magnetic evoked field (80 averagings) was measured from 37 points over occipital, temporal, and parietal areas (Magnes SQUID biomagnetometer, BTi) of the right brain hemisphere. Dipole estimates based on equal magnetic field contours (190 ms after motion frame onset with value of goodness of fit greater than 0.95) and MRI image fitting (sagittal, coronal, and axial view) for each subject suggest that the main loci subserving motion perception lie in the surrounding region over occipital, temporal, and parietal junction areas in the human brain close to area MT.

Visually Evoked Magnetic Field Induced by Ring Motion Aftereffect

Motion aftereffect (MAE) is a negative aftereffect caused by prolonged viewing of visual motion: after gazing at a moving grating for a while, a stationary image will appear to move in the opposite direction (Ashida and Osaka, 1995 Vision Research35 1825). Evoked magnetic field (magnetoencephalogram: MEG) was measured when a human subject observing ring MAE in which concentric circles appear to contract continuously after viewing continuously expanding rings. The diameter of the stimulus was 20 deg with fixation point in the centre. The magnetic evoked field (80 averagings at a latency of 190 ms) was measured from 37 points over the occipital and parietal areas (Magnes SQUID biomagnetometer, BTi) while the subject was observing stationary rings after an adaptation period of 2 s at low spatial frequency (4 cycles deg−1, 4 Hz). The luminance profile was sinusoidally changed across rings. MRI image fitting (sagittal, coronal, and axial view) for each of four subjects, and dipole estimates obtained for equal magnetic field contours (with value of goodness of fit greater than 0.98) from the right brain hemisphere suggest that the main loci subserving MAE lie in the surrounding region over the lateral occipitotemporal areas in the human brain, close to area MT. This is in good agreement with another study with fMRI-based MAE measures [Tootell et al, 1995 Nature (London)375 139] in which a clear increase in activity in these areas was observed when subjects viewed MAE.

Immunohistochemical detection of advanced glycosylation end-products in the peritoneum and its possible pathophysiological role in CAPD

It has recently been suggested that advanced glycosylation end-products (AGEs) are formed in the peritoneum in patients on CAPD. However, the exact location of AGE accumulation, the relation with the duration of CAPD and its pathophysiological role in CAPD remain unclear. If the peritoneum is glycosylated, it could bring about altered peritoneal function. Therefore, the aim of this study is to clarify the localization of AGEs in the peritoneum in accordance with the duration of CAPD and to examine its relation to the peritoneal permeability. Fifteen non-diabetic patients were divided into three groups (each 5 patients) on the basis of the mean duration (D) of CAPD (Group 1, D = 0 month; Group II, D = 34 months; Group III, D = 84 months). The AGE staining by monoclonal anti-AGE antibody in the peritoneum and the four-hour peritoneal equilibration test (PET) were compared among these groups. AGE was absent or found only weakly in Group I. However, in groups II and III, AGE was moderately or strongly positive especially in the vascular walls and it was dominant in group III. PET revealed that peritoneal permeability for glucose, creatinine, beta2-microglobulin and albumin was increased in Group II as compared to Group I, and it was further increased in Group III. The results of this study indicate that AGEs become dominantly accumulated in the vascular wall in accordance with the prolongation of CAPD treatment, and this might play some roles for the increased permeability of the peritoneal membrane in CAPD.

[Evaluation of nutritional status of patients on continuous ambulatory peritoneal dialysis (CAPD) by dual photon energy X-ray absorptiometry (DEXA)]

Malnutrition is a serious complication in patients on long-term CAPD treatment. Accordingly, quantitative evaluation of nutritional status is a critical issue. This study aimed to assess nutritional status by dual photon energy x-ray absorptiometry (DEXA) in CAPD patients. Total lean body mass (D-TBM), right arm lean mass (D-RAM) and body fat percent (D-% FAT) measured by DEXA were compared with mid-arm muscle circumference (MAMC) and body fat percent (AP-% FAT) measured by anthropometrics (AP) in 51 CAPD patients. The subjects were stratified into groups by gender, age, duration on CAPD, and diabetes mellitus or non-diabetes. There was significant correlation between D-TBM, D-RAM and MAMC (r = 0.519, p = 0.001, r = 0.545, p = 0.001) or D-% FAT and AP-% FAT (r = 0.763, p = 0.0001). However, in the groups of females with over 50 years and over 48 months of dialysis duration, there was no correlation between D-TBM, D-RAM and MAMC. The DEXA method is useful in the quantitative evaluation of nutritional status of dialysis patients serially.

Re-evaluation of local adaptation for motion aftereffect

A motion aftereffect (MAE) can be induced by stimuli moving in surrounding areas. This suggests the relevance of mechanisms for relative motion, rather than early-level motion detectors, which are considered to work locally. Experiments are reported in which the role of local adaptation in the MAE with a stimulus configuration comprising relative motion has been discussed. Sinusoidal gratings were presented in three rectangular windows: a centre window, and two windows one above and one below the central one. The surrounding top and bottom windows, which were divided into left and right halves, had gratings presented in only one of the two halves. The MAE duration was measured after adaptation to motion either in the central or in the surrounding windows, by controlling the regions with the gratings. From this, the regions of surrounding gratings were found not to have a significant effect with adaptation in the centre window. With adaptation in the surrounds, however, these regions did affect the MAE; the MAE duration was reduced when the adapted region had no gratings in the test phase. Thus, for an MAE it is necessary for the adapted area to be covered with stimuli in the test phase, which indicates the dominance of local adaptation for the MAE even when relative motion is relevant in producing the MAE.

Evoked Magnetic Field Elicited by Motion and Motion Aftereffect

Motion aftereffect (MAE) is a negative aftereffect caused by prolonged viewing of visual motion: after gazing at a moving grating for a while, a stationary image will appear to move in the opposite direction (Ashida and Osaka, 1995 Vision Research35 1825). Evoked magnetic field (magnetoencephalogram: MEG) was measured on a human subject observing visual motion and MAE. Magnetic evoked field (80 averagings) was measured from 37 points over occipital and parietal areas (Magnes SQUID biomagnetometer, BTi) during watching a horizontally moving sinusoidal grating with low spatial frequency (2 cycles deg−1 with 5 Hz: motion condition) and immediately after stopping the moving grating (MAE condition). Dipole estimates based on equal magnetic field contour suggest that the main loci subserving visual motion and MAE appear to be the surrounding region over occipital and parietal areas in the human brain. Further analysis is now underway. In general, this appears to be in good agreement with another study using fMRI-based MAE measures [Tootell et al, 1995 Nature (London)375 139] in which a clear increase in activity in these areas was observed when subjects viewed MAE.

Low calcium (1.25 mmol/L) dialysate can normalize relative hypoparathyroidism in CAPD patients with low bone turnover

Recently, several reports have suggested that there is a higher incidence of low turnover bone in the absence of aluminium exposure in peritoneal dialysis patients than in hemodialysis patients. Relative hypoparathyroidism with mild hypercalcemia, induced by a positive calcium balance, is considered to be one of the major causes of this disorder. Thus, we recruited 9 continuous ambulatory peritoneal dialysis (CAPD) patients with relative hypoparathyroidism and low bone turnover [intact parathyroid hormone (iPTH) < 50 pg/mL, intact osteocalcin < 10.0 ng/mL] who had been prescribed 1.75 mmol/L calcium (Ca) dialysate for 5.0 +/- 0.3 years. They were then treated by low Ca (1.25 mmol/L) dialysate for nine months without vitamin D and aluminum administration. Intact PTH and bone metabolic markers [intact osteocalcin, alkaline phosphatase (ALP)] were measured every three months. Intact PTH levels increased from 21.1 +/- 3.8 to 159.2 +/- 32.8 pg/mL after the first three months; thereafter, those levels were maintained at around 150 pg/mL. On the other hand, intact osteocalcin levels rose consecutively from 6.7 +/- 1.2 to reach 22.0 +/- 3.8 ng/mL after nine months. Interestingly, the pattern of time course changes between PTH and intact osteocalcin was different. ALP activity did not change during the nine-month period. Corrected serum calcium was significantly decreased (p < 0.001) to approximately 0.25 mmol/L within one month, and the level remained almost the same thereafter. The serum phosphate level did not change without adjusting the original dose of calcium carbonate as a phosphate binder. We concluded that low Ca dialysate (1.25 mmol/L) is effective for the treatment of CAPD-related hypoparathyroidism with low bone turnover.

Motion aftereffect with flickering test stimuli depends on adapting velocity

Temporal tuning property of motion aftereffect (MAE) with flickering test stimuli (flicker MAE) was examined. Using sinusoidal gratings of several spatial frequencies (SF), MAE strength was measured for various adapting temporal frequencies (TF). Unlike the traditional MAE with static test field, the results indicated that flicker MAE did not depend on TF. Rather, when plotted as a function of velocity, the peaks had approximately the same adapting velocity of 5-8 deg/sec for all SF conditions tested, suggesting velocity dependence. This is further support of the idea that the two kinds of MAE are of different origin and suggests a higher origin of flicker MAE, perhaps in the area MT or MST.

[Working memory capacity related to reading: measurement with the Japanese version of reading span test]

The efficiency of working memory capacity was measured with the Japanese reading span test (Japanese RST), which was developed based on the Carnegie-Mellon RST (Daneman & Carpenter, 1980). The correlation between the Japanese and the CMU RST was found to be highly significant. The present Japanese RST seems to predict reading efficiency in the same way as does the CMU RST. The Japanese RST was found to be correlated not only with memory span but with reading comprehension. However, it was not correlated with existing verbal intelligence tests.

Difference of spatial frequency selectivity between static and flicker motion aftereffects

The strength of motion aftereffect (MAE) was measured with the use of sinusoidal gratings of several spatial frequencies, to examine the spatial frequency selectivity of two types of MAE. With ordinary static grating as a test stimulus, to measure 'static MAE', the maximum aftereffect for each adapting spatial frequency was obtained at the testing stimuli of the same spatial frequency, showing spatial frequency selectivity. However, in the case when the sinusoidally flickering grating was used as a test stimulus, to measure 'flicker MAE', no spatial frequency selectivity was observed. The two types of MAE were considered to be based on different mechanisms. Static MAE is thought to depend on the spatiotemporal channel mechanism in the early processing stages, whereas flicker MAE might reflect higher-level processes which might occur at the extrastriate regions.

Long-term prognosis of esophageal variceal cases treated with injection sclerotherapy

One hundred fifty-two patients with esophageal varices underwent a total of 485 injection sclerotherapy procedures (mean, 3.2 times per each case). During 5 years of observation, 20 cases (13.2%) died following injection sclerotherapy. The 3-year survival rates, based on the Kaplan-Meier method, were 42% for emergency cases, 75% for elective cases and 90% for prophylactic cases. Significant differences (P less than 0.05) by the generalized Wilcoxon test were observed in the survival rates between emergency cases and prophylactic cases, and also between elective cases and prophylactic cases. Two cases (8.6%) of failure to control acute hemostasis were experienced. Twenty cases of bleeding after sclerotherapy were experienced, and 8 died of bleeding. The three-year bleeding rate according to the Kaplan-Meier method was 59% for emergency cases, 25% for elective cases and 7% for prophylactic cases. A significant difference (P less than 0.05) by the generalized Wilcoxon test was observed in the bleeding rate between elective cases and prophylactic cases. Non-bleeding rate (100%-bleeding rate) after sclerotherapy showed almost the same values as the survival rate. These results indicate that upper digestive tract hemorrhage influences the prognosis of patients after sclerotherapy.

Chromatographic separation and identification of naturally occurring chlorogenic acids by 1H nuclear magnetic resonance spectroscopy and mass spectrometry

The high-performance liquid chromatographic separation and identification of the phenolic compounds in extracts from coffee bean are described. The system consists of Fine SIL C18-5 analytical and preparative columns and gradient elution (solvent A, 10 mM H3PO4; solvent B, methanol). The seven chlorogenic acids isolated were identified by mass spectrometry and nuclear magnetic resonance spectroscopy. The isolated and identified compounds are 3-O-caffeoylquinic acid, 4-O-caffeoylquinic acid, 5-O-caffeoylquinic acid, 3,4-O-dicaffeoylquinic acid, 3,5-O-dicaffeoylquinic acid, 4,5-O-dicaffeoylquinic acid and 3-O-feruloylquinic acid.