Suppression of allergic inflammation by the prostaglandin E receptor subtype EP3

Prostaglandins, including PGD(2) and PGE(2), are produced during allergic reactions. Although PGD(2) is an important mediator of allergic responses, aspirin-like drugs that inhibit prostaglandin synthesis are generally ineffective in allergic disorders, suggesting that another prostaglandin-mediated pathway prevents the development of allergic reactions. Here we show that such a pathway may be mediated by PGE(2) acting at the prostaglandin E receptor EP3. Mice lacking EP3 developed allergic inflammation that was much more pronounced than that in wild-type mice or mice deficient in other prostaglandin E receptor subtypes. Conversely, an EP3-selective agonist suppressed the inflammation. This suppression was effective when the agonist was administered 3 h after antigen challenge and was associated with inhibition of allergy-related gene expression. Thus, the PGE(2)-EP3 pathway is an important negative modulator of allergic reactions.     

Effects of Daily Matcha and Caffeine Intake on Mild Acute Psychological Stress-Related Cognitive Function in Middle-Aged and Older Adults: A Randomized Placebo-Controlled Study

Matcha, a type of green tea, has a higher amino acid content than other types of tea. We previously examined the ability of matcha to improve cognitive function in older adults and determined that continuous matcha intake improves attention and executive function. This study aimed to compare the effects of matcha and caffeine and clarify the differences between these effects. The study was registered at the University Hospital Medical Information Network (UMIN000036578). The effect of single and continuous intake was compared, and the usefulness of continuous intake was evaluated under the stress condition. The Uchida–Kraepelin test (UKT) was used to induce mild acute stress, and the Cognitrax was used to evaluate cognitive function. A single dose of caffeine improved attentional function during or after stress loading. The reduced reaction time in the Cognitrax, observed following a single dose of matcha, was likely due to caffeine. The matcha group showed an increase in the amount of work after continuous intake, whereas the caffeine group only showed an increase in the amount of work for the UKT after a single dose. Ingesting matcha with caffeine improves both attention and work performance when suffering from psychological stress compared with caffeine alone.     

Risk Factor Analysis of Facet Fusion Following Cervical Lateral Mass Screw Fixation with a Minimum 1-Year Follow-up: Assessment of Maximal Insertional Screw Torque and Incidence of Loosening

Posterior stabilization is a common surgical procedure, which aims for rigid stabilization by facet fusion. Facet non-union has a potential risk of the screw loosening and malalignment. Although some authors have reported the influencing factors about screw loosening in the lumbar spine, there are few reports about the risk factor contributing to the facet non-union in the cervical spine. In all, 22 patients (78 facets and 122 screws) with degenerative cervical kyphosis or spondylolisthesis who underwent decompression and lateral mass screw (LMS) fixation were analyzed. Age, gender, smoking, bone mineral density (BMD), the degree of facet decortication with bone packing, and screw loosening were investigated as risk factors contributing to the facet non-union at each segmental fused level. Facet fusion rate was 85.9% (67/78 facets) and the incidence of loosening was 4.9% (6/122 screws, 4 patients). Insufficient facet decortication with bone packing is a significant risk factor of facet non-union (p <0.05, odds ratio: 26.5). All six loosened screws were associated with bony non-union of the facet and were located in the uppermost or lowermost vertebrae. Comparing loosened screws and stable screws, the average maximal insertional screw torque (MIT) was 9.8 cNm and 39.5 cNm, respectively (p <0.05). Additionally, the length of the stable screws was significantly longer versus the loosened screws (p <0.05). Lower MIT and shorter screw length located near the ends of the lateral mass may predict loosening, which can lead to facet non-union. Sufficient facet decortication with bone packing is one of the important factors contributing to the facet fusion.     

Characteristics affecting cervical sagittal alignment in patients with chronic low back pain

BackgroundSagittal spino-pelvic malalignment in patients with chronic low back pain (CLBP) have been reported in the past, which may also affect cervical spine lesions. The purpose of this study is to investigate the cervical alignment in patients with CLBP.MethodOf the patients who visited an orthopedic specialist due to low back pain lasting more than three months, 121 cases (average 71.5-years-old, 46 male and 75 female) with whole standing spinal screening radiographs were reviewed (CLBP group). Cervical parameters included cervical lordosis (CL), C2–C7 sagittal vertical axis (C2-7 SVA), and the T1 slope minus CL (T1S-CL). Cervical spine deformity was defined as C2-7 SVA >4 cm, CL <0°, or T1S-CL ≧20°. We compared the cervical alignment of these patients with 121 age and gender matched volunteers (control group).ResultsThe prevalence of cervical spine deformity was significantly higher in the CLBP group than in the control group (20.7% vs. 10.7%, P = 0.034). The mean CL was smaller in the CLBP group than in the control group (16.1° vs. 21.4°, P = 0.002). The mean C2-7 SVA was 17.6 mm vs. 18.7 mm in the CLBP group and in the control group, respectively (P = 0.817). The mean T1S-CL was larger in the CLBP group than in the control group (9.1° vs. 3.5°, P < 0.001). Multivariate analysis showed that people with CLBP were more likely to have cervical deformities than people without CLBP (odds ratio 2.16, 95% confidence interval 1.006 to 4.637).ConclusionsThis study results suggest that people with CLBP present with worse cervical sagittal alignment and higher prevalence of cervical spine deformities than age and gender matched volunteers with no CLBP. This means CLBP impacts cervical spine lesions negatively.Level of evidenceⅣ     

Deuterium chemical shift imaging for the estimation of cerebral perfusion in rabbit infarction model

In order to develop a new technique for the measurement of local cerebral blood flow (CBF), the deuterium chemical shift imaging (²H-CSI) technique, an application of in vivo nuclear magnetic resonance (NMR), was used for the estimation of cerebral perfusion in rabbit infarction model. The ²H chemical shift images of rabbit brain were obtained every 30 seconds before and after intravenous injection of deuterated saline. The changes in ²H NMR signal intensity documented that the cerebral perfusion in the damaged area due to infarction decreased obviously compared to that in the intact area. These findings indicate that the ²H-CSI technique can be applied to the measurement of local CBF. The readily availability and limited toxicity of deuterated water may make possible to use this method in clinical cases.(Kito K, Arai T, Mori K, et al.: Deuterium chemical shift imaging for the estimation of cerebral perfusion in rabbit infarction model. J Anesth 7: 447–453, 1993)     

An aminopeptidase inhibitor, bestatin, enhances progesterone and oestradiol secretion by porcine granulosa cells stimulated with follicle stimulating hormone in vitro

We examined the presence of cell surface aminopeptidase on culturedporcine granuiosa cells by employing the aminopeptidase assayusing alanine-p-nitroanilide and histochemical staining usingL-leucyl-β-naphthylamide. Porcine granuiosa cells obtainedfrom follicles 4–5 mm in diameter were cultured for 7days. The aminopeptidase assay showed that the porcine granuiosacell culture had aminopeptidase activity and that this activitywas inhibited in a dose-dependent manner by bestatin which bindsto cell surfaces and inhibits cell surface aminopeptidases.Histochemical staining also indicated that cultured granuiosacells had aminopeptidase activity. Porcine granuiosa cells werecultured in the presence or absence of porcine follicle stimulatinghormone (FSH, 3.125 nmol/1) and/or bestatin (0.4, 4.0 and 40.0µ/ml) for 7 days, and the production of progesterone andoestradiol was measured. In the presence of porcine FSH, theproduction of progesterone and oestradiol by granuiosa cellswas increased significantly by 5- and 2-fold respectively. Theseincreases were enhanced further by bestatin (40.0 (µg/ml).In the absence of porcine FSH, progesterone production was enhancedby bestatin (40.0 µg/ml), whereas no significant effectof bestatin on oestradiol secretion was observed. These findingsindicate that the inhibition of membrane-bound amino-peptidase(s)on the cell surfaces affects the steroidogenesis of granuiosacells, and that these aminopeptidase(s) are important regulatorsof granuiosa cell differentiation.