Acquired cystic disease of the kidney and renal carcinoma in haemodialysis patients: ultrasonographic evaluation.

Ultrasonography was performed in 661 dialysis patients and acquired cystic disease of the kidney was found in 156 (125 men and 31 women). A higher incidence of cystic disease was found in males. There was no significant difference between the patients with and those without acquired cystic disease in terms of average age, but the duration of haemodialysis in those with acquired cystic disease was significantly longer. There was an increased incidence of cystic disease in patients with glomerulonephritis and the duration of haemodialysis in these patients was significantly longer. This suggests that the increased incidence of acquired cystic disease of the kidneys in the patients with glomerulonephritis is simply related to the longer duration of treatment. Twelve patients with renal carcinoma were found in this study. The average age at diagnosis of renal carcinoma was not significantly different between the patients with and those without acquired cystic disease, but the duration of dialysis was significantly longer in renal carcinoma patients with acquired cystic disease. The incidence of renal carcinoma in dialysis patients with acquired cystic disease was 3.85% and in those without it was 1.19%. These rates are considerably higher than those found in the general population and indicate that the risk of renal carcinoma is higher in dialysis patients both with and without acquired cystic disease.     

Wear properties of alumina/zirconia composite ceramics for joint prostheses measured with an end-face apparatus

While only alumina is applied to all-ceramic joint prostheses at present, a stronger ceramic is required to prevent fracture and chipping due to impingement and stress concentration. Zirconia could be a potential substitute for alumina because it has high strength and fracture toughness. However, the wear of zirconia/zirconia combination is too high for clinical use. Although some investigations on composite ceramics revealed that mixing of different ceramics was able to improve the mechanical properties of ceramics, there are few reports about wear properties of composite ceramics for joint prosthesis. Since acetabular cup and femoral head of artificial hip joint are finished precisely, they indicate high geometric conformity. Therefore, wear test under flat contact was carried out with an end-face wear testing apparatus for four kinds of ceramics: alumina monolith, zirconia monolith, alumina-based composite ceramic, and zirconia based composite ceramic. Mean contact pressure was 10 MPa and sliding velocity was 40 mm/s. The wear test continued for 72 hours and total sliding distance was 10 km. After the test, the wear factor was calculated. Worn surfaces were observed with a scanning electron micrograph (SEM). The results of this wear test show that the wear factors of the both composite ceramics are similarly low and their mechanical properties are much better than those of the alumina monolith and the zirconia monolith. According to these results, it is predicted that joint prostheses of the composite ceramics are safer against break down and have longer lifetime compared with alumina/alumina joint prostheses.     

Asymmetries of prefrontal cortex in human episodic memory: effects of transcranial magnetic stimulation on learning abstract patterns

Functional neuroimaging suggests asymmetries of memory encoding and retrieval in the prefrontal lobes, but different hypotheses have been presented concerning the nature of prefrontal hemispheric specialization. We studied an associative memory task involving pairs of Kanji (Chinese) pictographs and unfamiliar abstract patterns. Subjects were ten Japanese adults fluent in Kanji, so only the abstract patterns represented novel material. During encoding, transcranial magnetic stimulation (TMS) was applied over the left and right dorsolateral prefrontal cortex (DLPFC). A significant (P<0.05) reduction in subsequent recall of new associations was seen only with TMS over the right DLPFC. This result suggests that the right DLPFC contributes to encoding of visual-object associations, and is consistent with a material-specific rather than a process-specific model of mnemonic function in DLPFC.     

The accuracy and performance of the A&D TM 2421, a new ambulatory blood pressure monitoring device based on the cuff-oscillometric method and the Korotkoff sound technique.

The accuracy and performance of the A&D TM 2421, a new ambulatory blood pressure (BP) monitoring device using both the cuff-oscillometric method (O) and the Korotkoff sound method (K) were evaluated. The device was tested for accuracy under static and dynamic conditions by simultaneous comparison with two observers using a standard mercury column sphygmomanometer (standard method) and by the objective recording method (ORM). The performance of the device was also evaluated under ordinary ambulatory conditions. The mean differences in BP of standard method from K-method were -1.2 +/- 4.7 mm Hg systole and 1.3 +/- 4.7 mm Hg diastole (n = 323, mean +/- SD) and those of standard method from O-method were -0.4 +/- 5.3 mm Hg systole and 1.4 +/- 5.1 mm Hg diastole (n = 323). The agreement between each of the two methods of the device and the standard method was within 10 mm Hg for more than 90% of both systolic and diastolic readings. During bicycle exercise, the mean differences in BP of standard method from K-method were -3.4 +/- 4.8 mm Hg systole and 1.8 +/- 5.2 mm Hg diastole (n = 71) and those of standard method from O-method were -1.1 +/- 7.3 mm Hg systole and 1.7 +/- 7.8 mm Hg diastole (n = 67). There was a greater scatter in the individual comparisons of the device and the standard method during exercise, especially in diastolic BP. The relation between the device and ORM was almost similar to that between the device and the standard method.(ABSTRACT TRUNCATED AT 250 WORDS)     

Direct Impact of Motor Cortical Stimulation on the Blood Oxygen-level Dependent Response in Rats

Purpose:Neuropathic pain is a complex and distressing chronic illness in modern medicine. Since 1990s, motor cortex stimulation (MCS) has emerged as a potential treatment for chronic neuropathic pain; however, the precise mechanisms underlying analgesia induced by MCS are not completely understood. The purpose of the present study was to investigate the blood oxygen-level dependent (BOLD) response in the brain during MCS.Methods:We inserted a bipolar tungsten electrode into the primary motor cortex (M1) of adult male Wistar rats. Functional magnetic resonance imaging (fMRI) scans were implemented simultaneously with the electrical stimulation of M1 and the BOLD signals taken from the fMRI were used as an index to reflect the response against MCS.Results:Our results demonstrated that the bilateral M1, ipsilateral caudate-putamen, and ipsilateral primary somatosensory cortex to the stimulation spot were activated after the onset of MCS. The BOLD signal time courses were analysed in these regions and similar temporal characteristics were found.Conclusion:By conducting direct cortical stimulation of the rodent brain to investigate its instant effect using fMRI, we identified encephalic regions directly involved in the instant motor cortical stimulation effects in healthy rat models. This result may be essential in establishing a foundation for further research on the underlying neuropathways associated with the MCS effects.     

Sorption capacity of seaweed-like sodium titanate mats for Co2+ removal

The development of new technologies for securing and recycling water resources are in high demand. A key focus of these technologies is the development of various ion exchangers or adsorbents that are used for the purification of aqueous solutions. Layered sodium titanate is one of the cation exchangers utilised in the removal of heavy metals and radionuclides from wastewater. To enhance the removal efficiency, the precise design of the crystal morphology, structure, and chemical composition is important. Herein, we synthesised a unique seaweed-like sodium titanate mat (SST) using a template-free alkaline hydrothermal process. The Co²⁺ sorption capacity of SST was investigated by batch testing with cobalt(ii) nitrate. SST, which was synthesised from titanium sulphate in a 10 M NaOH solution at 200 °C, had a seaweed-like structure composed of randomly distributed nanofibres of layered sodium titanate that is approximately 9 nm in diameter. The crystal shape changed from roundish crystals to fibrous crystals as the hydrothermal reaction period increased. The Co²⁺ sorption isotherm of SST was fitted with the Langmuir isotherm model and the maximum sorption density was 1.85 mmol g⁻¹. The selectivity of the Co²⁺ sorption on SST was high in comparison to that of Ca²⁺ and Mg²⁺. Herein, the Co²⁺ sorption mechanisms of SST were studied in comparison with commercially available sodium titanate. Results show that controlling the crystal morphology, structure, and Na concentration of the layered titanate that can be ion-exchanged determines the cation sorption properties of sodium titanate.

The seaweed-like sodium titanate mat has a high Co²⁺ sorption capacity via the ion-exchange reaction due to its crystal structure, low crystallinity, and morphology.     

Effect of Porphyromonas gingivalis Lipopolysaccharide on Bone Marrow Mesenchymal Stem Cell Osteogenesis on a Titanium Nanosurface

Background: Titanium (Ti) dental implants have been widely used for prosthetic reconstruction of dentition. Unfortunately, peri‐implantitis can result in failure of dental implant osseointegration. Lipopolysaccharide (LPS) acts as a chronic inflammatory stimulus and maintains peri‐implant inflammation, worsening the prognosis for implant osseointegration. The purpose of this study is to determine the effects of 10 M NaOH‐modified Ti surface with nanonetwork structure on the proliferation and osteogenic differentiation of rat bone marrow mesenchymal stem cells (BMMSCs) in the context of Porphyromonas gingivalis LPS exposure. Methods: Titanium disks treated with 10 M NaOH solution and control were incubated with BMMSCs and exposed to P. gingivalis LPS (0, 0.1, or 1 μg/mL). The effects of the modified nanonetwork structure on osteogenic differentiation of rat BMMSCs were evaluated in the context of different concentrations of P. gingivalis LPS exposure. Results: Rat BMMSCs on the 10 M NaOH‐modified Ti surface with nanonetwork structure had higher levels of osteogenesis‐related gene expression and significantly greater cell proliferation, alkaline phosphatase activity, and extracellular matrix deposition and mineralization than cells on the untreated Ti surfaces, in all the groups with different doses of P. gingivalis LPS exposure. Conclusion: The 10 M NaOH‐modified Ti surface with nanonetwork structure has better endotoxin tolerance under P. gingivalis LPS exposure than the non‐modified surface.     

Correlations between pentraxin 3 or cytokine levels in gingival crevicular fluid and clinical parameters of chronic periodontitis

The gingival crevicular fluid (GCF) contains various biomarkers, such as interleukin (IL)-1β, IL-6, IL-8, tumor necrosis factor-α (TNF-α), and IL-10, among others. These cytokines have been reported to correlate with gingival inflammation and periodontal status. Therefore, the analysis of GCF may be useful for the diagnosis of periodontal status. Pentraxin 3 (PTX3) is the first identified long pentraxin, and is released by several cell types in response to proinflammatory signals. The aim of this study was to determine the levels of IL-1β, IL-6, IL-8, TNF-α, IL-10 and PTX3 in GCF from diseased and healthy sites in patients with chronic periodontitis. Cross-sectional clinical data were obtained from 50 patients with chronic periodontitis. GCF samples were collected with paper strips from one periodontal diseased site and one periodontally healthy site per subject. The levels of IL-1β, IL-6, IL-8, IL-10 and TNF-α were determined using a multiplexed bead immunoassay, and the PTX3 level was measured using an enzyme-linked immunosorbent assay. Mean clinical parameters were significantly higher at diseased sites (P < 0.01) as compared to healthy sites, and the mean levels of PTX3, IL-1β, IL-6, IL-8, IL-10 and TNF-α were higher in diseased sites (P < 0.01) than in healthy sites. There were strong correlations between PTX3 or IL-1β and periodontal status. These results suggest that GCF PTX3 levels might be useful as a diagnostic marker for periodontal disease.