Phospholipase D Family Member 4, a Transmembrane Glycoprotein with No Phospholipase D Activity, Expression in Spleen and Early Postnatal Microglia

BACKGROUND: Phospholipase D (PLD) catalyzes conversion of phosphatidylcholine into choline and phosphatidic acid, leading to a variety of intracellular signal transduction events. Two classical PLDs, PLD1 and PLD2, contain phosphatidylinositide-binding PX and PH domains and two conserved His-x-Lys-(x)(4)-Asp (HKD) motifs, which are critical for PLD activity. PLD4 officially belongs to the PLD family, because it possesses two HKD motifs. However, it lacks PX and PH domains and has a putative transmembrane domain instead. Nevertheless, little is known regarding expression, structure, and function of PLD4. METHODOLOGY/PRINCIPAL FINDINGS: PLD4 was analyzed in terms of expression, structure, and function. Expression was analyzed in developing mouse brains and non-neuronal tissues using microarray, in situ hybridization, immunohistochemistry, and immunocytochemistry. Structure was evaluated using bioinformatics analysis of protein domains, biochemical analyses of transmembrane property, and enzymatic deglycosylation. PLD activity was examined by choline release and transphosphatidylation assays. Results demonstrated low to modest, but characteristic, PLD4 mRNA expression in a subset of cells preferentially localized around white matter regions, including the corpus callosum and cerebellar white matter, during the first postnatal week. These PLD4 mRNA-expressing cells were identified as Iba1-positive microglia. In non-neuronal tissues, PLD4 mRNA expression was widespread, but predominantly distributed in the spleen. Intense PLD4 expression was detected around the marginal zone of the splenic red pulp, and splenic PLD4 protein recovered from subcellular membrane fractions was highly N-glycosylated. PLD4 was heterologously expressed in cell lines and localized in the endoplasmic reticulum and Golgi apparatus. Moreover, heterologously expressed PLD4 proteins did not exhibit PLD enzymatic activity. CONCLUSIONS/SIGNIFICANCE: Results showed that PLD4 is a non-PLD, HKD motif-carrying, transmembrane glycoprotein localized in the endoplasmic reticulum and Golgi apparatus. The spatiotemporally restricted expression patterns suggested that PLD4 might play a role in common function(s) among microglia during early postnatal brain development and splenic marginal zone cells

A Prospective Comparative Study of Mastication Predominance and Masticatory Performance in Kennedy Class I Patients

Mastication predominance in Kennedy class I (KC I) patients has not been well defined. This study aimed to investigate mastication predominance and masticatory performance in KC I patients, including the significance of remaining posterior teeth and removable partial-denture (RPD) treatment. KC I patients who had differences in the number of posterior teeth between left and right sides (D+) and KC I patients who had no differences (D−) were enrolled. Healthy dentate (HD) subjects were also registered as a positive control. Mastication predominance, defined by mastication predominance index (MPI; range 0–100%) calculated from electromyogram activities during voluntary chewing, and masticatory performance were evaluated at pre- and post-RPD treatment. Pre-MPI in KC I D+ was significantly higher than in HD. RPD treatment could significantly improve MPI and masticatory performance in both KC I groups. However, there were significant differences in masticatory performance between each KC I group and HD, regardless of RPD treatment. It was considered that the mastication predominance in KC I patients was affected by the difference in the number of remaining posterior teeth. RPD treatment could improve mastication predominance and masticatory performance in KC I patients, although the latter was not similar to HD group

A case of APMPPE-like panuveitis presenting with extensive outer retinal layer impairment following COVID-19 vaccination

Abstract Background Vaccination against the worldwide pandemic coronavirus disease 2019 (COVID-19) is underway; however, some cases of new onset uveitis after vaccination have been reported. We report a case of bilateral acute posterior multifocal placoid pigment epitheliopathy-like (AMPPE-like) panuveitis after COVID-19 vaccination in which the patient’s pathological condition was evaluated using multimodal imaging. Case presentation A 31-year-old woman experienced bilateral hyperemia and blurred vision starting 6 days after her second inoculation of the COVID-19 vaccination. At her first visit, her visual acuity was decreased bilaterally, and severe bilateral anterior chamber inflammation and bilateral scattering of cream-white placoid lesions on the fundus were detected. Optical coherence tomography (OCT) showed serous retinal detachment (SRD) and choroidal thickening in both eyes (OU). Fluorescein angiography (FA) revealed hypofluorescence in the early phase and hyperfluorescence in the late phase corresponding to the placoid legions. Indocyanine green angiography (ICGA) showed sharply marginated hypofluorescent dots of various sizes throughout the mid-venous and late phases OU. The patient was diagnosed with APMPPE and was observed without any medications. Three days later, her SRD disappeared spontaneously. However, her anterior chamber inflammation continued, and oral prednisolone (PSL) was given to her. Seven days after the patient’s first visit, the hyperfluorescent lesions on FA and hypofluorescent dots on ICGA partially improved; however, the patient’s best corrected visual acuity (BCVA) recovered only to 0.7 OD and 0.6 OS, and the impairment of the outer retinal layer was broadly detected as hyperautofluorescent lesions on fundus autofluorescence (FAF) examination and as irregularity in or disappearance of the ellipsoid and interdigitation zones on OCT, which were quite atypical for the findings of APMPPE. Steroid pulse therapy was performed. Five days later, the hyperfluorescence on FAF had disappeared, and the outer retinal layer improved on OCT. Moreover, the patient’s BCVA recovered to 1.0 OU. Twelve months after the end of treatment, the patient did not show any recurrences. Conclusions We observed a case of APMPPE-like panuveitis after COVID-19 vaccination featuring some atypical findings for APMPPE. COVID-19 vaccination may induce not only known uveitis but also atypical uveitis, and appropriate treatment is required for each case

Clinical significance of serum and vitreous soluble interleukin-2 receptor in patients with intraocular lymphoma

Background Intraocular lymphoma (IOL) is a masquerade syndrome that mimics uveitis, making diagnosis difficult. The serum soluble interleukin-2 receptor (sIL-2R), which is cleaved by matrix metalloproteinase (MMP) -2 and MMP-9, has been recognized as a tumor-related biomarker of malignant lymphomas. The aim of this study was to review the reliability of serum and vitreous sIL-2R for distinguishing IOL from uveitis. Methods Patients who underwent diagnostic vitrectomy for marked vitreous haze at Hokkaido University Hospital between April 2014 and June 2019 were enrolled. The patients were divided into an IOL group and a uveitis group, according to the pathology of their vitreous samples. The IOL group was further divided at the time of vitrectomy into patients who already had extraocular involvement (IOL with extraocular involvement group) and patients with no evidence of having extraocular involvement (IOL without extraocular involvement group). Serum sIL-2R, and intravitreal sIL-2R, MMP-2, and MMP-9 levels were assessed. Results Twenty-five eyes of 25 patients, and 15 eyes of 15 patients were included in the IOL group and uveitis group, respectively. The serum sIL-2R levels were significantly lower in the IOL group than in the uveitis group (P < 0.05), and 20.0% and 66.7% in the IOL and the uveitis group showed high sIL-2R value above the normal range. Vitreous sIL-2R tended to be higher in the IOL group than in the uveitis group (P = 0.80). Serum sIL-2R was significantly lower in the IOL without extraocular involvement group than in the IOL with extraocular involvement group (P < 0.05); 5.9% in the IOL without extraocular involvement group and 50.0% in the IOL with extraocular involvement group showed high sIL-2R value above the normal range. Vitreous sIL-2R, MMP-2, and MMP-9 tended to be higher in the IOL with extraocular involvement group than in the IOL without extraocular involvement group (P = 0.30, < 0.05, 0.16). Conclusions Serum sIL-2R is often within the normal range in IOL patients. Even if it is within the normal range, the possibility of IOL should be considered. Serum sIL-2R is not a reliable biomarker for IOL, whereas vitreous sIL-2R may be useful for the diagnosis of IOL

Terahertz radiation from photoconductive switch fabricated from a zinc oxide single crystal

We present results on the terahertz (THz) radiation from a photoconductive switch fabricated on a zinc oxide (ZnO) single crystal. Due to its high transmittance in the visible, near-infrared, mid-infrared, and THz regions, ZnO may present itself as a viable material for integrated active optics operating in the THz region. © 2007 Springer-Verlag New York

Generation of terahertz radiation using zinc oxide as photoconductive material excited by ultraviolet pulses

Terahertz (THz) radiation generated from photoconductive antenna fabricated on a single crystal zinc oxide (ZnO) is presented. The THz-radiation power is saturated at bias voltages above 800 Vcm and the obtained spectrum extends up to 1 THz. Moreover, ZnO is found to be highly transparent in the visible, near-infrared, mid-infrared and THz frequency regions. The results depicted here will categorically unravel the prospects of using ZnO as a material for integrated active optics. © 2005 American Institute of Physics