Journal of Medical and Dental Sciences最新文献

The choroid plexus (CP) is present on the ventricular walls of the brain, produces cerebrospinal fluid (CSF), contains many blood vessels, and is a major functional component of the blood-CSF barrier. The CP is an important site in the pathophysiology of various neurological diseases, including Alzheimer's disease and meningeal amyloidosis. We performed gene silencing in the CP in vivo by using an antisense oligonucleotide (ASO). A short ASO of length 12 nucleotides was intravenously injected into rats. The ASO was not delivered to neurons or glia in the central nervous system, but was successfully delivered into the CP, and resulted in a significant reduction of endogenous target gene expression in epithelial cells within the CP. Although the mechanism of uptake of the ASO by the CP was not elucidated, the ASO bound to albumin in vivo, and the distribution of ASO delivery was similar to that of albumin delivery. These findings suggest that we inhibited target gene expression in the epithelial cells of the CP via albumin-ASO conjugates. This strategy should be useful for investigations of the function of CP, and for the development of new gene-silencing therapies for diseases with pathophysiology related to the CP.

Various gelatinizers, which facilitate oral ingestion, are employed in patients with dysphagia. The purpose of this study was to histologically clarify the influence of various gelatinizers on the lung, using rats. We administered 0.2 ml/kg of 0.1% xanthangam, a 0.25% commercially available xanthangam gelatinizer, 0.35% ι-carrageenan, 0.5% κ-carrageenan, 1% gelatin, 0.15% agar, physiological saline, tap water, and isopropanolpurified 0.1% xanthangam/0.35% ι-carrageenan into the trachea of 8- to 9-week-old male SD rats. The lungs were extirpated after 24 and 72 hours. Neutrophil infiltration in the alveolar space was expressed as the mean number of neutrophils in 30 randomly selected high-power fields. In the xanthangam (451.0 ± 204.0 cells) -, and the ι -carrageenan (424.4 ± 257.2) treated groups, the neutrophil counts after 24 hours was significantly greater than in the physiological saline (33.0 ± 22.6) - treated group (p < 0.05). In the available xanthangam gelatinizer (290.0 ± 86.8) -treated group was no significant difference in the physiological saline-treated group. In the isopropanol-purified xanthangam (90.2 ± 42.3)-treated group, the neutrophil counts after 24 hours were significantly smaller than in the nonpurified xanthangam -treated group.These results suggest that lung tissue inflammatory response-inducing features depend on the type of gelatinizer. On the other hand, purification reduces the lung-damaging features of xanthangam.

Previous research has shown that mastication reduces shifts in the center of gravity of persons standing still. The present research was conducted to determine whether mastication improves reactive balance in the standing position in response to unanticipated external disturbances. The subjects were 32 healthy male adults (mean age 21.1 years, standard deviation (SD) 0.7 years). Latency data determined with the Motor Control Test of Computerized Dynamic Posturography (CDP) were compared for the three conditions of mastication status, the direction of translation, and the magnitude of translation, using three-way repeated measures ANOVA and lower-order ANOVA with the three conditions separated. Latency was significantly shorter with mastication than with the lower jaw relaxed (P < 0.00001). Mastication alone, however, cannot be considered significant because of the complex interactions involved among the three conditions. Mastication increases not only static balance but also reactive balance in response to unanticipated external disturbances. Gum chewing may therefore reduce falls among elderly persons with impaired balance.

L-arginine is the common substrate for arginase and nitric oxide synthase (NOS). Arginase converts L-arginine to urea and L-ornithine. L-Ornithine is the principal precursor for the production of polyamines and L-proline, which are required for cell proliferation and collagen synthesis. Endothelial NOS is expressed in the human endometrial glandular epithelium, but the expression and physiological roles of arginase in the human endometrium are not clear. The objective of this study was to investigate the expression and distribution patterns of arginases Ⅰ (A-Ⅰ) and Ⅱ (A-Ⅱ) in the human endometrium by using immunohistochemistry, reverse transcription-polymerase chain reaction (RTPCR), and western blotting. A-Ⅰ and A-Ⅱ were detected by immunohistochemistry in human endometrial epithelial cells during the proliferative and secretory phases of the menstrual cycle. RT-PCR showed that A-Ⅰ and A-Ⅱ mRNA were expressed in human endometrial tissue. Western blotting analysis results showed the expression of A-Ⅱ protein. Immunohistochemistry and western blotting results showed that expression levels of A-Ⅱ were significantly higher in the secretory phase than in the proliferative phase. Increased A-Ⅱ levels in the secretory phase may be responsible for endometrial growth by increasing polyamines and proline products.

Osteoclasts are multinucleated cells of hematopoietic origin which are unique in their ability to resorb bone. Osteoclasts are generated from myeloid progenitors through a progression that involves the fusion of mononuclear precursor cells. The identification of RANK-RANKL signaling as the main signal regulating osteoclast differentiation was a major breakthrough in the bone biology field. In addition remarkable discoveries have been made to broaden the knowledge of the molecular mechanisms of osteoclast formation and differentiation. Despite the vital requirement of osteoclasts in bone modeling and remodeling, bone-related conditions like osteoporosis, Paget's disease and rheumatoid arthritis where accelerated bone resorption takes place pose a major socioeconomic burden to the society. Hence, a better understanding of the pathways leading to osteoclast differentiation is vital in successfully managing such diseases. This is an attempt to give a birds-eye-view of the players in osteoclast formation and differentiation in a brief and concise manner.

Background: Although attritive and abrasive wear of recent composite resins has been substantially reduced, in vitro wear testing with reasonably simulating devices and quantitative determination of resulting wear is still needed. Three-dimensional scanning methods are frequently used for this purpose. The aim of this trial was to compare maximum depth of wear and volume loss of composite samples, evaluated with a contact profilometer and a non-contact CCD camera imaging system, respectively.

Method: Twenty-three random composite specimens with wear traces produced in a ball-on-disc sliding device, using poppy seed slurry and PMMA suspension as third-body media, were evaluated with the contact profilometer (TalyScan 150, Taylor Hobson LTD, Leicester, UK) and with the digital CCD microscope (VHX1000, KEYENCE, Osaka, Japan). The target parameters were maximum depth of the wear and volume loss.Results - The individual time of measurement needed with the non-contact CCD method was almost three hours less than that with the contact method. Both, maximum depth of wear and volume loss data, recorded with the two methods were linearly correlated (r(2) > 0.97; p < 0.01).

Conclusion: The contact scanning method and the non-contact CCD method are equally suitable for determination of maximum depth of wear and volume loss of abraded composite resins.