Serum Creatinine-Cystatin C Based Screening of Sarcopenia in Community Dwelling Older Adults: A Cross-Sectional Analysis.

OBJECTIVES: To compare the discriminative capabilities for the manifestation of sarcopenia or physical frailty between serum creatinine- and cystatin C-derived indices among community-dwelling older adults. DESIGN: Cross-sectional study. SETTING: Primary Care and Community. PARTICIPANTS: We utilized a subset of data from the Frail Elderly in the Sasayama-Tamba Area (FESTA) study, which was initiated in 2015 to gather comprehensive information on various health-related parameters among community-dwelling older individuals (age ≥65 years). MEASUREMENTS: Five serum creatinine-cystatin C based indices including the Sarcopenia Index, the serum creatinine/cystatin C ratio, the disparity between serum cystatin-C-based and creatinine-based estimated GFR, the total body muscle mass index (TBMM), and the prediction equation for skeletal muscle mass index (pSMI) were employed. Sarcopenia and physical frailty were identified based on the Asian Working Group for Sarcopenia criteria and the revised Japanese version of the Cardiovascular Health Study criteria, respectively. The receiver operating characteristic (ROC) and logistic regression analyses were performed to assess the discriminative abilities of these tools. RESULTS: In the analysis of 954 participants, 52 (5.5%) were identified with sarcopenia and 35 (3.7%) with physical frailty. Regarding sarcopenia discrimination, TBMM and pSMI both exhibited area under the curve (AUC) values exceeding 0.8 for both men and women. Concerning the identification of physical frailty, AUC values ranged from 0.61 to 0.77 for males and 0.50 to 0.69 for females. In the multivariate logistic regression analyses, only TBMM and pSMI consistently displayed associations with sarcopenia, irrespective of sex (P<0.001, respectively). On the other hand, no consistent associations were observed between the indices and physical frailty. CONCLUSIONS: This study provides a robust association of a serum creatinine- and cystatin C-derived indices, especially TBMM and pSMI, with sarcopenia among community-dwelling older adults. Conversely, the application of these indices for the screening of physical frailty has its constraints, necessitating further investigation.

Relationship Between Cerebral Blood Oxygenation and Electrical Activity During Mental Stress Tasks: Simultaneous Measurements of NIRS and EEG.

The incidence of stress-induced psychological and somatic diseases has been increasing rapidly, and it is important to clarify the neurophysiological mechanisms of stress response in order to establish effective stress management methods. We previously reported that the prefrontal cortex (PFC) plays an important role in stress response. In the present study, we employed near-infrared spectroscopy (NIRS) and electroencephalography (EEG) to investigate the characteristics of PFC activity during mental arithmetic tasks. A two-channel NIRS device was used to measure hemoglobin (Hb) concentration changes in the bilateral PFC during a mental arithmetic task (2 min) in normal adults. Simultaneously, EEG was used to also measure bilateral PFC activity during the same task. We evaluated concentration changes of oxy-Hb induced by the task while analyzing α wave changes using power spectrum analysis. It was observed that oxy-Hb in the bilateral PFC increased significantly during the task (p < 0.05), while α wave power in the PFC decreased significantly (p < 0.01). The present results indicate that mental stress tasks caused the activation of the bilateral PFC. Simultaneous measurements of NIRS and EEG are useful for evaluating the neurophysiological mechanism of stress responses in the brain.

Development of an IoT-Based Monitoring System for Healthcare: A Preliminary Study.

We present an IoT-based monitoring system for healthcare that allows for long-term measurements of blood pressure (BP), heart rate (HR), and body weight (BW), as well as near-infrared spectroscopy (NIRS) for measurement of prefrontal cortex (PFC) activity. To verify the applicability of the system, it was set up in a local fitness gym for a preliminary study. A total of 39 subjects, selected from members of the gym, participated in the study. We analyzed the BP, HR, and BW data, collected from the subjects over one half-year. In addition, to assess the degree of mental stress of the subjects, we analysed left-right asymmetry of the PFC activity using the laterality index at rest (LIR) of the NIRS parameter. Results show that the subjects were able to measure their physiological data by themselves when they visited the gym, after being instructed how to perform the measurements. Furthermore, the results also indicate that ordinary people can continuously monitor physiological functions such as brain function in a non-medical facility, such as a fitness gym.

Development of a Cuff-Less Blood Pressure Monitoring System and Its Application.

We present an unobtrusive cuff-less sphygmomanometer based on contact-type and optical pulse sensors for continuous and minimally invasive monitoring of blood pressure (BP). We developed a cuff-less sphygmomanometer that utilizes the pulse arrival time (PAT) to estimate continuous BP. To assess its accuracy, we recruited 10 healthy subjects in whom we carried out BP studies using the cuff-less sphygmomanometer compared with a standard cuff-type device in a stationary sitting patient. Preliminary results showed that the mean difference (MD) of estimated systolic blood pressure and diastolic blood pressure were 0.96 ± 9.6 (mean ± SD) mmHg and 1.14 ± 7.5 mmHg, respectively, compared to the control. The corresponding correlation between the estimated BP values and controls were 0.78 for systolic blood pressure (p < 0.01) and 0.69 for diastolic blood pressure (p < 0.01); thus, there were significant correlations. These results suggest that the developed cuff-less sphygmomanometer has the potential for continuous BP monitoring. Finally, we conducted a preliminary study of simultaneous monitoring of cuff-less BP and near-infrared spectroscopy to evaluate the potential for assessment of autonomic nervous system functions during mental stress tasks.

Transportation of sublingual antigens across sublingual ductal epithelial cells to the ductal antigen-presenting cells in mice.

BACKGROUND: Sublingual immunotherapy (SLIT) has proven to be safe and efficient for the treatment of type I allergies. However, the mechanisms underlying allergen transportation within the sublingual compartment, the localization of antigens, and the identities of the cells responsible for this immunization remain incompletely understood. OBJECTIVE: In this study, we focused on the sublingual ductal system and analysed the localization and transportation of antigens after their sublingual application. METHODS: In mice given adjuvant-free antigens sublingually, tissues were removed at 0, 0.5, 1, or 2 h after the application and subjected to immunohistochemistry. Cells isolated from the sublingual duct and mucosa were analysed by flow cytometry. RESULTS: Substantial immunoreactivity to ovalbumin (OVA) was evident in sublingual ductal epithelial cells at 30 min and 1 h after sublingual administration of OVA, but it had disappeared at 2 h. The ductal epithelial cells incorporated not only OVA, but also particulate antigens such as latex or silica beads and microbes. MHC class II (MHCII)(+) antigen-presenting cells (APCs) were located around the sublingual ductal system, and MHCII(+) cells were co-localized with, and around, antigen-incorporated sublingual duct cells. CD11b(+) CD11c(-) cells were present among CD45(+) MHCII(+) cells at greater frequency in the sublingual duct than in the sublingual mucosa, and they were the main contributors to the incorporation of OVA in vitro. CONCLUSIONS AND CLINICAL RELEVANCE: This study reveals that sublingual antigens can be transported across sublingual ductal epithelial cells to the ductal APCs. If the system is the same in humans as in mice, the ductal APCs may prove to be important target cells for SLIT.

Myostatin alters glucose transporter-4 (GLUT4) expression in bovine skeletal muscles and myoblasts isolated from double-muscled (DM) and normal-muscled (NM) Japanese shorthorn cattle.

The purpose of this study was to determine whether myostatin alters glucose transporter-4 (GLUT4) expression in bovine skeletal muscles and myoblasts isolated from double-muscled (DM) and normal-muscled (NM) Japanese Shorthorn cattle. Plasma concentrations of glucose were lower in DM cattle than in NM cattle (P < 0.01). The expression of GLUT4 messenger RNA (mRNA) in the skeletal muscle ex vivo and in myoblasts at 72 h after differentiation in vitro was higher in DM cattle than in NM cattle (P < 0.01). In contrast, the NM and DM cattle did not differ with respect to skeletal muscle expression of GLUT1 and myocyte enhancer factor-2c (MEF2c), a transcription factor of GLUT4. In differentiated myoblasts, the expression of GLUT1, GLUT4, and MEF2c mRNAs was greater in DM cattle than in NM cattle (P < 0.01). In the presence and absence of insulin, glucose uptake in myoblasts was increased in DM cattle relative to that of NM cattle (P < 0.01). The addition of myostatin decreased the expression of GLUT4 and MEF2c mRNAs in DM myoblasts (P < 0.05). Results of the present study suggest that myostatin inhibits the expression of GLUT4 mRNA possibly via MEF2c and that the greater ability of the DM cattle to produce muscle relative to the NM cattle may be due to their greater sensitivity to insulin and greater use of glucose.

Deiodinase 2 upregulation demonstrated in osteoarthritis patients cartilage causes cartilage destruction in tissue-specific transgenic rats.

OBJECTIVE: Chondrocyte hypertrophy followed by cartilage destruction is a crucial step for osteoarthritis (OA) development, however, the underlying mechanism remains largely unknown. The objectives of this study are to identify the gene that may cause cartilage hypertrophy and to elucidate its role on OA pathogenesis. DESIGN: Gene expression profiles of cartilages from OA patients and normal subjects were examined by microarray analysis. Expression of deiodinases, enzymes for regulation of triiodothyronine (T3) biosynthesis, in human and rat articular cartilage (AC) were examined by real-time quantitative reverse transcriptase-polymerase chain reaction (qRT-PCR). Rat ACs and chondrocytes were treated with T3 to investigate its role on chondrocyte hypertrophy and inflammatory reaction. Cartilage-specific Type II deiodinase (DIO2) transgenic rats were generated using bacterial artificial chromosome harboring the entire rat Col2a1 and human DIO2 gene. An experimental OA model was created in the animal to examine the role of DIO2 on cartilage degeneration. RESULTS: DIO2 is highly expressed in OA patient AC compared to normal control. In rat AC, DIO2 is specifically expressed among deiodinases and dominantly expressed the same as in brown adipose tissue. T3 induces hypertrophic markers in articular chondrocyte and cartilage explant culture, and enhances the effect of IL-1α on induction of cartilage degrading enzymes. Importantly, cartilage-specific DIO2 transgenic rats are more susceptible to knee joint destabilization and develop severe AC destruction. CONCLUSION: Our findings demonstrate that upregulated expression of DIO2 in OA patient cartilage might be responsible for OA pathogenesis by enhancing the chondrocyte hypertrophy and inflammatory response.

Age and sex differences of controlled force exertion measured by a computer-generated quasi-random target-pursuit system.

OBJECTIVES: This study examined age and sex differences of controlled force exertion measured by a computer-generated quasi-random target-pursuit system in 207 males and 249 females aged 15 to 86 years. METHODS: The participants matched submaximal grip exertion of their dominant hand to changing demand values, appearing as a moving quasi-random waveform on the display of a personal computer. They performed the test three times with 1-min intervals (one trial was 40 sec). The total sum of the percent of differences between the demand value and the grip exertion value for 25 sec was used as an evaluation parameter. RESULTS: The errors in controlled force exertion tended to increase constantly with age in both sexes. Significant linear regressions were identified, but there was no significant difference in the rate of increase in both sexes. Analysis of variance showed nonsignificant sex differences among means, except for those in individuals older than 60 years; significant differences between means in the groups older than the 40 yr.-old age group and the 20-24 yr.-old group were found in both sexes. CONCLUSIONS: Controlled force exertion did not show a significant sex difference and decreased gradually with age in both sexes, but decreased remarkably after 40 years of age.

Differences and relationships between residual volumes measured on land and in water calculated from estimate equations.

AIM: Residual volume error influences percent body fat estimated by hydrostatic. The aim of this study was to examine the differences and relationships between the residual volumes measured on land and in water and calculated from estimate equations developed in previous studies. PARTICIPANTS: 20 males and 20 females, aged 18-25 years, participated in this study. SETTING: the residual volumes on land and in water without submerging their head were measured twice in each setting. In addition, the residual volume was calculated from 6 estimate equations developed in previous studies. RESULTS: Residual volumes measured on land and in water have very good trial-to-trial reliabilities (intraclass correlation coefficients: <0.98), and high relationships, and did not show a significant difference. It is inferred that their difference is approximately 500 mL, being larger than trial-to-trial error. If we attach great importance to practicability rather than the above error, the residual volume on land can be used. There were no significant differences between measured volumes and those estimated by equation 5 in males and all equations except equation 6 in females. The relationships between measured and estimated residual volumes were poor in males except for equation 4, but were fair in females. Trial-to-trial reliability of residual volumes measured on land and in water is very good, and they have insignificant differences and high relationships. CONCLUSION: Of 6 estimate equations, equation 4 calculated from vital capacity has high accuracy in both sexes.

The characteristics of simple muscle power by gripping: gender differences and reliability of parameters using various loads.

AIM: There are few studies on muscle power during local muscle contractions with a small range of motion such as in gripping. The purposes of this study were to clarify the properties of the developmental phase based on time series of muscle power output, the reliability of the parameters, their relationships and the load intensity derived peak power by gender differences, and to examine the possibility of evaluating muscle power using gripping. METHODS: Fifteen young males and 15 females participated in this study. Based on a crossover experimental design, each subject carried out 2 explosive grips at 20%, 30%, 40% and 50% loads of maximal using a voluntary grip contraction (MVC). The grip contraction velocities, sampled at 100 Hz, were measured accurately using a power instrument with an accelerometer. Muscle power curves were drawn from the product of the velocity and the set-up load. RESULTS: The cross-correlation coefficients between the trials for the average curve of the time-series moving distance, the velocity, and the power in any load were very high (over 0.95) in both genders. The reliability of each parameter was mostly good in both genders (intraclass correlation coefficient, ICC>0.75). The peak power curve differed between genders, and the curve around the peak value in females was irregular. CONCLUSIONS: A gender difference was found in the maximal power and the properties of the power curve. The maximal muscle power appeared at 30-50% MVC in males, and at 20-40% MVC in females. The peak power during the whole contraction, and the time to peak may reflect the conditions throughout the whole of the contraction. The new device used in this study to evaluate local regional muscle power (grip) is a very reliable and useful tool.

Gastrin activates nuclear factor kappaB (NFkappaB) through a protein kinase C dependent pathway involving NFkappaB inducing kinase, inhibitor kappaB (IkappaB) kinase, and tumour necrosis factor receptor associated factor 6 (TRAF6) in MKN-28 cells transfected with gastrin receptor.

BACKGROUND: We previously reported that gastrin induces expression of CXC chemokines through activation of nuclear factor kappaB (NFkappaB) in gastric epithelial cells that express gastrin receptor. AIMS: To clarify gastrin receptor mediated signals leading to activation of NFkappaB. METHODS: MKGR26 cells were created by transfecting gastrin receptor cDNA into MKN-28 cells. Degradation of inhibitor kappaB (IkappaB) and phosphorylation of protein kinase C (PKC)-delta were both detected by western blot analysis. NFkappaB activation was determined by luciferase assay and electrophoretic mobility shift analysis. RESULTS: Gastrin induced degradation of IkappaB-alpha and activation of NFkappaB, which was abolished by the selective gastrin receptor antagonist L-740,093 and the general PKC inhibitor GF109203X. Gastrin induced phosphorylation of PKC-delta, and its inhibitor rottlerin partially suppressed NFkappaB activation. However, the mitogen activated protein kinase (MAPK) kinase inhibitor PD98059, p38 MAPK inhibitor SB203580, and tyrphostin AG1478 had no effect on NFkappaB activation. Introduction of the dominant negative mutant of IkappaB kinase, of NFkappaB inducing kinase, and of tumour necrosis factor receptor associated factor 6 (TRAF6), but not that of TRAF2, inhibited gastrin induced activation of NFkappaB. CONCLUSIONS: Gastrin activates NFkappaB via a PKC dependent pathway which involves IkappaB kinase, NFkappaB inducing kinase, and TRAF6.

Reliability and gender differences of static explosive grip parameters based on force-time curves.

AIM: The purpose of this study was to examine the reliability and gender differences of static explosive grip (SEG) parameters based on force-time curves. EXPERIMENTAL DESIGN: data were collected from 2 trials of SEG tests on the same day and 2 trials 1 week later. PARTICIPANTS: 50 healthy young males (21.2+/-1.57 yrs) and females (20.1+/-1.18 yrs) participated in this study. MEASURES: 12 variables based on factors such as time-course of force, average force, integrated area, maximal rate of force development, the product of force and inclination and exponential function of force development (EXP-M) were selected as force-time parameters in SEG testing. RESULTS: A significant reliability was obtained for all force-time parameters except the time to 90% of maximal grip strength (MAX), with the reliability of integrated area, average force, maximal rate of force development (DFmax), and the product of force and inclination being particularly high (ICC=0.633-0.930 for the same day, ICC=0.612-0.828 for different days). There were gender differences for all parameters except the time to MAX and EXP-M (p<0.05). In addition, many of the correlation coefficients between parameters were high, particularly for males. The average force, integrated area for 1 sec, and the product of force and inclination during the developmental phase significantly correlated with MAX in both males and females. The ratio between males and females in these force-time parameters was smaller than that of MAX (71.3%). CONCLUSION: It is considered that these parameters are dependent on the speed of muscle contraction. These results suggest that the evaluation parameters, such as average force, integrated area, the product of force and inclination, and maximal rate of force development are useful for evaluating static explosive grip.

The influence of transient change of total body water on relative body fats based on three bioelectrical impedance analyses methods. Comparison between before and after exercise with sweat loss, and after drinking.

BACKGROUND: The purpose of this study was to clarify the influence of change of total body water caused by exercise and drinking, on relative body fat (%BF) based on three bioelectrical impedance analyses (BIA) methods, between hand and foot (H-F), between hand and hand (H-H), and between foot and foot (F-F). METHODS: The subjects were 30 Japanese healthy young adults aged 18 to 23 years (15 males, 15 females). Measurements were made three times for each BIA method; before and after exercise with sweat, and after drinking, and also twice according to the under water weighing (UW) method, before exercise and after drinking. A pedaling exercise, with a bicycle ergometer, was used for 60 minutes as the exercise. RESULTS: The relationship of %BF between the UW method and each BIA method was mid-range or more (r=0.765-0.839). However, %BF based on the H-F and F-F BIA methods were higher than that based on the UW method. After drinking, %BF of all the BIA methods were higher than the UW method. %BF of the BIA methods after exercise indicated values lower than those before exercise. %BF of the H-F and H-H BIA methods after drinking were a little higher than those before exercise, indicating that those measurements reflect a slight change of body water. CONCLUSIONS: It was demonstrated that %BF of any BIA method reflect the change of body water caused by exercise, sweating, and drinking.

PPARgamma agonists inhibit cell growth and suppress the expression of cyclin D1 and EGF-like growth factors in ras-transformed rat intestinal epithelial cells.

Peroxisome proliferator-activated receptor gamma (PPARgamma) inhibits the growth of several types of cancer cells. However, the mechanisms by which this occurs are poorly understood. The goal of the present study was to investigate the effects of PPARgamma on mutated ras-induced cell growth, activation of transcription factors and expression of genes associated with cellular transformation in rat intestinal epithelial cells. A human PPARgamma cDNA was introduced to the activated H-ras-transfected IEC-6 cells (IECras) and 1 clone (IECrasPR82) that stably expresses both activated ras and PPARgamma was obtained. Thiazolidinedione derivatives such as troglitazone and rosiglitazone, selective ligands for PPARgamma, inhibited the cellular growth of IECrasPR82 cells in a time-dependent manner and induced G1 cell cycle arrest. Treatment with troglitazone (20 microM) decreased the expression of cyclin D1, heparin-binding epidermal growth factor-like growth factor (HB-EGF) and amphiregulin and suppressed the promoter activities of cyclin D1 and HB-EGF. Furthermore, a luciferase assay and an electrophoretic mobility shift assay showed that thiazolidinedione derivatives suppressed the transcriptional activities of AP-1 and Ets, both of which play crucial roles in the expression of cyclin D1 and HB-EGF. These findings suggest that reduction of EGF-like growth factors and cyclin D1 through the suppression of AP-1 and Ets may be 1 mechanism whereby PPARgamma inhibits their growth.

Lateral dominance of legs in maximal muscle power, muscular endurance, and grading ability.

The purpose of this study was to examine lateral dominance in maximal muscle power, muscular endurance, and grading ability, using isokinetic mulscular strength in knee extension and flexion. The subjects were 50 healthy male students whose ages ranged from 19 to 23 years (M height: 173.6+/-6.2 cm, M weight: 67.2+/-6.8 kg). Their dominant legs for power exertion and for functional use were based on questionnaire items selected from those used in previous studies. The angular velocities of extension and flexion for exerting maximal muscle power were 60, 180, and 300 x sec.(-1). A continuous exertion 30 times at an angular velocity of 180 sec.(-1) was used as the load for muscular endurance. For grading ability, 25%, 50% and 75% of the maximal muscle strength at angular velocities of 60 and 180 x sec.(-1) were the required values, and the difference between these values and the exerted muscular strength was evaluated. The dominant leg and nondominant leg were compared for both power exertion and functional use. There was no lateral dominance in maximal muscle power and muscular endurance. In muscular endurance, especially, some subjects showed one leg superior in power exertion and some superior in functional use. Lateral dominance was noted across maximal muscle power and muscular endurance in grading ability. The dominant leg tended to be better than the nondominant leg in functional use. However, lateral dominance was not remarkable for flexing motion and in exertion for a short time.

Force developmental phase and reliability in explosive and voluntary grip exertions.

The purposes of this study were to clarify the reliability of two types of grip exertions, explosive grip exertion and voluntary grip exertion up to the maximal grip strength and to examine their force patterns using force-time parameters. Subjects were 100 healthy young male volunteers (age: 17.8+/-2.50 yr.) who had no upper limb injury. Grip strength was measured two times with voluntary grip and then two times with explosive grip. 11 parameters derived from the force-time curve were selected to measure the developmental phase of muscle contraction. The reliability of maximal grip strength in explosive and voluntary grip exertions was very high (intraclass correlation = .95, .93). The difference between two trials in explosive grip tended to be smaller than that for voluntary grip, and reliability of the exertion pattern was higher for explosive grip than voluntary grip. The times to reach 90% of the maximal grip strength and the maximal grip strength in explosive grip were shorter than those in voluntary grip. The other 8 force-time parameters had higher values in explosive grip than voluntary grip and higher reliabilities. The force-time parameters reflect the properties of explosive exertion. The results suggest the possibility that static explosive strength could be evaluated using these force-time parameters.

[Factors related to satisfaction level in daily life for older people].

The purpose of this study was to examine relations between satisfaction levels and life-style in daily life for older people. A questionnaire, based on 7 factors of life satisfaction level and 13 factors of life-style chosen after considering theoretical validity, was administered to 1,320 healthy people aged 60 or more in the community (665 males and 655 females). Remarkable gender and grade differences were confirmed in the "physical health" satisfaction level. Satisfaction level for "personal relations" related to the number of friends for both sexes and to volunteer activities for males. The influence of the life-style factor on satisfaction level was highest in physical health. The influence of the number of friends was high for each satisfaction level. It was inferred that there are many aspects of life-style backgrounds contributing to the satisfaction level of older people in the community, and individual satisfaction with daily life is affected by different life-style factors.

Effects of hot bath immersion on autonomic activity and hemodynamics: comparison of the elderly patient and the healthy young.

Hot bathing has been associated with sudden death and so the present study investigated its effects on autonomic activity and hemodynamics in the elderly patient and the healthy young by analyzing heart rate variability (HRV). Subjects were 9 elderly men (mean age, 75 years) and 9 young men (mean age, 27 years), who were immersed up to shoulder level while in a sitting position for 10min with the bath temperature at 40 degrees C. Blood pressure (BP) and heart rate (HR) were monitored. BP in the young decreased during bathing (p<0.01), whereas in the elderly BP had a maximum value just at the start of immersion (p<0.05) with a slight decline at 4 min after the start of immersion. Although HR in the young increased (p<0.01), in the elderly there was an abrupt increase in HR just at the start of immersion (p<0.05), followed by a decrease in HR. With regard to HRV, the high-frequency (HF) component in the young men was suppressed during immersion (p<0.01), but was unaffected in the elderly. The LF (low frequency)/HF ratio in the elderly decreased at 4 min (p<0.05). In conclusion, hypotensive syncope may cause sudden death by drowning during hot bathing, and is a consequence of the decrease in sympathetic tone that develops approximately 4min after immersion.

Rapid and diverse changes of gene expression in the kidneys of protein-overload proteinuria mice detected by microarray analysis.

BACKGROUND: Microarray is a method that allows the analysis of a large number of genes at the same time. We applied this method to show the difference of gene expression in the kidney caused by proteinuria. METHODS: An experimental mouse model of protein overload was prepared by bovine serum albumin injection. The mRNAs of kidneys isolated after 0, 1, 2, 3 and 4 weeks loading were analysed by Northern blotting. We analysed about 18000 genes by microarray. The expression patterns of the microarray were displayed on control, 1 and 3 weeks of protein overload using the clustering procedure. A clone showing the greatest changes of up-regulation in the kidney was cloned and analysed by in situ hybridization and immunohistochemistry. RESULTS: Over 1600 kinds of gene expression were confirmed in control kidneys. Proteinuria caused systematic changes of gene expression demonstrated by the cluster analysis. The up-regulation of osteopontin mRNA was shown and confirmed by Northern blot analysis. One of the clones showing the largest changes, AA275245, was isolated and characterized. It revealed that AA275245 was an unreported 3' non-coding region of vinculin mRNA which was associated with cytoskeleton proteins (e.g. alpha-actinin, talin, F-actin). Immunohistochemistry and in situ hybridization showed that this clone was identified in glomeruli as a mesangial pattern. The detected signal intensity using both methods, however, was virtually identical in control and disease kidney models. All data including images and analysed signal intensities are accessible on the web site. CONCLUSION: The microarray analysis revealed that the renal gene expression pattern was changed dynamically in mice with experimentally induced proteinuria within a few weeks.