Analysis of possible structures of inducible skin‐associated lymphoid tissue in lupus erythematosus profundus

Lupus erythematosus profundus (LEP) is a variant of lupus erythematosus, involving the deep dermis and subcutaneous fat. LEP is characterized by the presence of lymphoid follicles (LF) and germinal centers (GC). However, it remains unknown whether these lymphoid structures correspond to the lymphoid tissues such as cutaneous tertiary lymphoid organs (TLO). Previously, we identified dynamically orchestrated cellular elements in murine contact dermatitis that resembled lymphoid structures, which we termed inducible skin‐associated lymphoid tissues (iSALT). We subsequently reported structures analogous to iSALT in human secondary syphilis, suggesting that iSALT can also exist in humans. Here, we studied ectopic lymphoid tissues in the lesions of LEP by immunohistochemistry and compared their characteristics with those of TLO. We demonstrated that LF of LEP were composed of B‐cell follicles intermingled with CXCL13‐expressing cells, distinct aggregations of T cells, and some blood vessels expressing peripheral node addressin. These findings indicate that LF of LEP can be considered as a type of iSALT.     

A longitudinal study for the prediction of the mature acetabular morphology using childhood magnetic resonance imaging

BackgroundAlthough acetabular dysplasia is a common etiology of osteoarthritis of the hip regardless of the history of developmental dysplasia of the hip (DDH), whether or not corrective surgeries are beneficial for the childhood asymptomatic acetabular dysplasia remains controversial due to a lack of evidence. We conducted a longitudinal study to compare the cartilaginous morphology on childhood magnetic resonance imaging (MRI) and the mature hip morphology of the same patient and to assess the predictive indicators for future acetabular dysplasia.MethodsA total of 92 unaffected hips (47 unilateral DDH and 45 unilateral Legg-Calvé-Perthes disease) were reviewed for X-ray and MRI findings on childhood (mean age: 6.0 years) and X-ray findings from a skeletally mature age with a mean follow-up period of 15.1 years. The following parameters were measured and compared: the immature-acetabular index (AI) and center edge angle (CE) on immature X-ray; the cartilage- and bone- AI, CE, Sharp and acetabular head index (AHI) on childhood MRI; and the mature-acetabular roof obliquity (ARO), CE, Sharp and AHI on skeletally mature X-ray. The prognostic factors on childhood MRI for acetabular dysplasia, defined by a CE of <20° on skeletally mature X-ray were also assessed.ResultsPositive correlations were shown between the cartilage-AI and mature-ARO (7.6°/6.3°; r = 0.44), the cartilage-CE and mature-CE (27.8°/28.0°; r = 0.62), the cartilage-Sharp and mature-Sharp (44.4°/41.8°; r = 0.52) and the cartilage-AHI and mature-AHI (78.7%/80.3%; r = 0.46). A multivariate analysis indicated cartilage-CE to be an independent predictor for acetabular dysplasia with a cut-off value of 22°. Children with a cartilage-CE <22° developed more frequently acetabular dysplasia compared to the others (52.4% vs. 1.4%).ConclusionsChildhood MRI findings are useful for the prediction of acetabular dysplasia without a DDH history. Children with a cartilage-CE ≥23° are likely to achieve a non-dysplastic hip without the need for surgical intervention.     

Ultrasonic measurement of the effects of light irradiation and presence of water on the polymerization of self‐adhesive resin cement

Self‐adhesive resin cements are useful in restorations because they reduce the number of clinical steps involved in the restoration process. This study evaluated, using ultrasonic measurements, the influence of light irradiation and the presence of water on the polymerization behavior and elastic modulus of a self‐adhesive resin cement. A self‐adhesive resin cement (RelyX Unicem 2 Automix) or a resin cement (RelyX ARC) was inserted into a transparent mold on a sample stage, and the presence of water and effect of light‐irradiation were evaluated. The transit time of a sonic wave through the cement disk was divided by the specimen thickness to obtain the sonic velocity, and longitudinal and shear waves were used to determine the elastic modulus. When the resin cements were light‐irradiated, the sonic velocity rapidly increased and plateaued at 2,500–2,700 m s^?1. When the cements were not irradiated, the rates of increase in the sonic velocity were reduced. When water was applied to the sample stage, the sonic velocity was reduced. The elastic modulus values of the specimens ranged from 9.9 to 15.9 GPa after 24 h. The polymerization behavior of self‐adhesive resin cements is affected by the polymerization mode and the presence of water.     

Protective Effects of a Hydrogen-Rich Preservation Solution in a Canine Lung Transplantation Model

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Comparative analyses of the two proliferating cell nuclear antigens from the hyperthermophilic archaeon,Thermococcus kodakarensis

The DNA sliding clamp is a multifunctional protein involved in cellular DNA transactions. In Archaea and Eukaryota, proliferating cell nuclear antigen (PCNA) is the sliding clamp. The ring‐shaped PCNA encircles double‐stranded DNA within its central hole and tethers other proteins on DNA. The majority of Crenarchaeota, a subdomain of Archaea, have multiple PCNA homologues, and they are capable of forming heterotrimeric rings for their functions. In contrast, most organisms in Euryarchaeota, the other major subdomain, have a single PCNA forming a homotrimeric ring structure. Among the Euryarchaeota whose genome is sequenced, Thermococcus kodakarensis is the only species with two genes encoding PCNA homologues on its genome. We cloned the two genes from the T. kodakarensis genome, and the gene products, PCNA1 and PCNA2, were characterized. PCNA1 stimulated the DNA synthesis reactions of the two DNA polymerases, PolB and PolD, from T. kodakarensis in vitro. PCNA2, however, only had an effect on PolB. We were able to disrupt the gene for PCNA2, whereas gene disruption for PCNA1 was not possible, suggesting that PCNA1 is essential for DNA replication. The sensitivities of the Δpcna2 mutant strain to ultraviolet irradiation (UV), methyl methanesulfonate (MMS) and mitomycin C (MMC) were indistinguishable from those of the wild‐type strain.