In chemo-mechanical caries removal procedures, chloramines are typically used for chemical softening of carious dentin. However, the specific effect of chloramines to be compared to sodium hypochlorite has not been sufficiently clarified. In present study, the effect of chloramines used in the Carisolv-system on carious dentin mechanical properties and morphology were investigated, using Vickers hardness test and scanning electron microscopy (SEM). Sections of permanent teeth with dentin caries were treated with chloramines, prepared by mixing amino acids (glutamic acid, lysine, and leucine) with sodium hypochlorite or with sodium hypochlorite alone or with purified water. There was a tendency that the application of the sodium hypochlorite solution softened the sound dentin and/or inner layer of carious dentin more than the application of the chloramines solution did. In SEM observations, the application of chloramines resulted in opening dentinal tubules in the outer layer of carious dentin: Occluded dentinal tubules were seen after sodium hypochlorite application. There is a possibility that the amino acids in the Carisolv-system decrease the aggressive effect of sodium hypochlorite on sound dentin and/or inner layer of carious dentin and also would enhance the disrupting effect on degenerated collagen in carious dentin outer layer.

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Recurrent herpes labialis (RHL) occurs in up to 40% of the population. Although the disease is usually self-limiting, patients seek treatment because of the significant pain and visibility of the lesion. Xanthine oxidase inhibitors (XOI) have been reported to have a potent antiviral effect against influenza-A virus. We examined the effect of the systemic xanthine oxidase inhibitor, allopurinol, on RHL duration of illness, severity of symptoms, number and frequency of recurrence during a 4- year follow up period in Egyptian patients. Duration of illness was shortened by about 25%, early disappearance of pain and other symptoms occurred. Also, aborted episodes were noticed when allopurinol was given just after beginning of common colds, at the prodromal stage of RHL or during severe stress conditions. Patients receiving 3 courses of treatment had markedly decreased recurrences during the follow up period. Ex vivo experiments to examine virus-induced plaque formation on Vero cells in the absence or presence of different concentrations of the drug could not prove any direct anti herpetic effect of the drug. However, allopurinol seems to be safe and effective in reducing duration of RHL and to abort lesion or prevent its appearance in treated patients even when they experience immunosuppressive conditions.

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CD23 has roles in proliferation, antigen uptake and presentation, and the generation of IgE. Signals through IL-4R and CD40 stimulate transcription of CD23 in B cells and are necessary for immunoglobulin class switch (IgCS). The same signals induce nuclear translocation of Ku, which is also required for IgCS, in human resting B cells, suggesting that these signaling pathways are connected. We examined the regulation of CD23 gene, and located the minimal promoter at -132+80 region. A pair of 188bp inverted repeats inhibited its activity. The intronic region including EBV responsive element (EBVRE) and the surrounding sequence, required the gene specific promoter to enhance the reporter gene activity. Western blotting and FACS analysis using subclones of DND39 B cells infected with recombinant EBV, revealed that CD23 upregulation did not necessarily correlate with EBNA 2 and LMP 1 expression. Although the specific binding of Ku to EBVRE was not demonstrated, dominant negative Ku80 suppressed IL-4 + anti-CD40-driven CD23 expression. These results suggest that Ku is involved in gene regulation as a signal transducer and gene enhance. Detailed analysis of CD23 gene regulation would lead to a better understanding of disorders such as allergy and lymphoproliferation.

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Spaceflight and bed rest induce loss of bone mass. A number of in vivo and in vitro studies have been conducted to clarify the mechanisms, however, the results have been conflicting. The purpose of this study was to investigate the effects of gravity unloading on proliferation, phenotypes, and apoptosis of normal human osteoblastic cells in the presence of 1α,25-dihydroxyvitamin D₃. We used a vector-averaged gravity condition generated by clinostat rotation to simulate gravity unloading. Clinostat rotation did not affect the cell proliferation. On the first day, the mRNA levels for osteocalcin, ALP, CBFA1, VDR, RANKL, and OPG were reduced by clinostat rotation to 21%, 65%, 62%, 52%, 43%, and 54% of control, respectively. ALP activity was decreased to 75% of control. On the second day, the mRNA levels for osteocalcin and RANKL were reduced to 77% and 61% of control, respectively. The decreased VDR mRNA level might be responsible for the reduction for mRNA levels for osteocalcin, RANKL, and OPG. Clinostat rotation increased the pro-apoptotic index (Bax/Bcl-2 ratio) but did not induce apoptosis due to the simultaneous upregulation of the anti-apoptotic XIAP. Reduction of osteoblast responsiveness to 1α,25-dihydroxyvitamin D₃ might be involved in osteopenia that is induced by gravity unloading.

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Spinal cord evoked potentials (SCEPs) measurement is widely used for level diagnosis of spondylotic myelopathy. However, because of the restriction of spatial resolution, SCEPs do not distinguish the neurophysiological activities among tracts in the spinal cord without invasive methods. Magnetic field measurement has the theoretical advantage of high spatial resolution, compared with electric measurement. We recorded spinal cord evoked magnetic fields (SCEFs) in the thoracic spinal cord after stimulation to the motor area in felines, and estimated the source of the magnetic fields. SCEFs showed a quadrupolar pattern, and conducted in a cranial-to-caudal direction at 55 m/sec. According to this result, we estimated that the SCEFs after stimulation to the motor area were generated by the contralateral corticospinal tract. Furthermore, the estimated dipole of the SCEFs after stimulation to the motor area was located on the contralateral side in the spinal cord. These results correspond with the anatomical location of the corticospinal tract of felines, and suggest that magnetic field recording can detect the magnetic source localization of each tract in the spinal cord.

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During orthodontic treatment, it is often necessary to move the hypofunctional teeth. In this study, we revealed an influence of orthodontic forces in the hypofunctional periodontal ligament, and focused on the distribution of proteoglycans, major extracellular matrix molecules. Five-week-old rats were divided into normal group and hypofunctional group. To induce occlusal hypofunction, occluding teeth of the mandibular first molar were extracted. At 8-week-old, orthodontic force by 15 or 2 gf titanium-nickel alloy closed coil spring was applied to the mandibular first molar toward the mesial direction. Immunohistochemical analysis was performed using antibodies for chondroitin sulfate (CS) and heparan sulfate (HS). In normal group, CS was observed throughout the extracellular matrix, while HS was observed on the endothelial cells and the osteoclastic cells on compressive side. In hypofunctional group without orthodontic appliance, CS and HS were detected in less amounts. With 15 gf, CS was observed at the compressive area where no cells and fibers were present, and HS was observed at the periphery of this area. With 2 gf, however, the distribution of CS and HS was similar to the normal control. These findings indicate that CS and HS were affected by orthodontic forces, and suggest their distinct functions in tissue remodeling.

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