Increased ghrelin signaling prolongs survival in mouse models of human aging through activation of sirtuin1

Caloric restriction (CR) is known to retard aging and delay functional decline as well as the onset of diseases in most organisms. Ghrelin is secreted from the stomach in response to CR and regulates energy metabolism. We hypothesized that in CR ghrelin has a role in protecting aging-related diseases. We examined the physiological mechanisms underlying the ghrelin system during the aging process in three mouse strains with different genetic and biochemical backgrounds as animal models of accelerated or normal human aging. The elevated plasma ghrelin concentration was observed in both klotho-deficient and senescence-accelerated mouse prone/8 (SAMP8) mice. Ghrelin treatment failed to stimulate appetite and prolong survival in klotho-deficient mice, suggesting the existence of ghrelin resistance in the process of aging. However, ghrelin antagonist hastened death and ghrelin signaling potentiators rikkunshito and atractylodin ameliorated several age-related diseases with decreased microglial activation in the brain and prolonged survival in klotho-deficient, SAMP8 and aged ICR mice. In vitro experiments, the elevated sirtuin1 (SIRT1) activity and protein expression through the cAMP-CREB pathway was observed after ghrelin and ghrelin potentiator treatment in ghrelin receptor 1a-expressing cells and human umbilical vein endothelial cells. Furthermore, rikkunshito increased hypothalamic SIRT1 activity and SIRT1 protein expression of the heart in the all three mouse models of aging. Pericarditis, myocardial calcification and atrophy of myocardial and muscle fiber were improved by treatment with rikkunshito. Ghrelin signaling may represent one of the mechanisms activated by CR, and potentiating ghrelin signaling may be useful to extend health and lifespan.

Ferroelectricity by Bose-Einstein condensation in a quantum magnet

The Bose–Einstein condensation is a fascinating phenomenon, which results from quantum statistics for identical particles with an integer spin. Surprising properties, such as superfluidity, vortex quantization or Josephson effect, appear owing to the macroscopic quantum coherence, which spontaneously develops in Bose–Einstein condensates. Realization of Bose–Einstein condensation is not restricted in fluids like liquid helium, a superconducting phase of paired electrons in a metal and laser-cooled dilute alkali atoms. Bosonic quasi-particles like exciton-polariton and magnon in solids-state systems can also undergo Bose–Einstein condensation in certain conditions. Here, we report that the quantum coherence in Bose–Einstein condensate of the magnon quasi particles yields spontaneous electric polarization in the quantum magnet TlCuCl₃, leading to remarkable magnetoelectric effect. Very soft ferroelectricity is realized as a consequence of the O(2) symmetry breaking by magnon Bose–Einstein condensation. The finding of this ferroelectricity will open a new window to explore multi-functionality of quantum magnets.

Magnons, quantized spin excitations in magnetic materials, may undergo Bose-Einstein condensation into a macroscopic correlated quantum state at low temperature. Here, the authors demonstrate how magnon condensation in quantum magnet TlCuCl₃ generates an electrical polarization.

Expression dynamics of CXCL12 and CXCR4 during the progression of mycosis fungoides

BACKGROUND

Mycosis fungoides (MF) classically presents from patch stage to plaque stage over a number of years and finally progresses to tumour stage with nodal or visceral involvement. The mechanism of progression remains incompletely elucidated. Chemokines and their receptors are known to be involved in disease mechanisms, with CXCL12 and CXCR4 playing a critical role in carcinogenesis, invasion and cancer cell migration in various carcinomas.

OBJECTIVES

To investigate the expression of CXCL12 and CXCR4 in different cutaneous stages of MF.

METHODS

Formalin-fixed, paraffin-embedded skin samples from 40 patients with MF (21 patch stage, 10 plaque stage, nine tumour stage) and 30 non-neoplastic control skin samples were analysed. CXCL12 and CXCR4 were assessed by quantitative reverse-transcription polymerase chain reaction and immunohistochemical staining.

RESULTS

The expression level of mRNA for CXCL12 in plaque-stage MF was significantly higher than in control skin (P = 0.0035), or patch-stage (P = 0.0108) or tumour-stage disease (P = 0.0089). The CXCR4 mRNA expression level in plaque-stage disease was significantly higher than in control skin (P = 0.0090) or patch-stage disease (P = 0.0387). CXCL12- and CXCR4-positive cell rates in patch-stage and plaque-stage MF were significantly higher than those in control skin (P < 0.0001). CXCL12- and CXCR4-positive cell rates in tumour-stage MF were significantly lower than those in patch- and plaque-stage disease (P = 0.0274 and P = 0.0492, respectively).

CONCLUSIONS

Our data suggest that neoplastic T cells in MF are exposed to the microenvironment, given the abundance of CXCL12 during its progression, and also that neoplastic T cells express CXCR4, especially in the pretumour stage. We reveal that the CXCL12-CXCR4 axis plays a critical role in MF progression.

Assessment of interfractional prostate motion in patients immobilized in the prone position using a thermoplastic shell

The aim of this study was to evaluate the interfractional prostate motion of patients immobilized in the prone position using a thermoplastic shell. A total of 24 patients with prostate calcifications detectable using a kilo-voltage X-ray image-guidance system (ExacTrac X-ray system) were examined. Daily displacements of the calcification within the prostate relative to pelvic bony structures were calculated by the ExacTrac X-ray system. The average displacement and standard deviation (SD) in each of the left-right (LR), anterior-posterior (AP), and superior-inferior (SI) directions were calculated for each patient. Based on the results of interfractional prostate motion, we also calculated planning target volume (PTV) margins using the van Herk formula and examined the validity of the PTV margin of our institute (a 9-mm margin everywhere except posteriorly, where a 6-mm margin was applied). In total, 899 data measurements from 24 patients were obtained. The average prostate displacements ± SD relative to bony structures were 2.8 ± 3.3, -2.0 ± 2.0 and 0.2 ± 0.4 mm, in the SI, AP and LR directions, respectively. The required PTV margins were 9.7, 6.1 and 1.4 mm in the SI, AP and LR directions, respectively. The clinical target volumes of 21 patients (87.5%) were located within the PTV for 90% or more of all treatment sessions. Interfractional prostate motion in the prone position with a thermoplastic shell was equivalent to that reported for the supine position. The PTV margin of our institute is considered appropriate for alignment, based on bony structures.

Prediction of time-dependent interaction of aspirin with ibuprofen using a pharmacokinetic/pharmacodynamic model

WHAT IS KNOWN AND OBJECTIVE

Low-dose aspirin is widely used for prevention of thrombosis, but combined use of aspirin with non-steroidal anti-inflammatory drugs (NSAIDs), such as ibuprofen, reduces the antiplatelet effect of aspirin. However, there has been no report describing the effects of the timing of the ibuprofen dose on the degree of interaction between low-dose aspirin and ibuprofen. The purpose of this study was to predict the time-course of the antiplatelet effect of low-dose aspirin when ibuprofen is administered as a single dose or repeatedly in combination with aspirin at various time intervals.

METHODS

We simulated ex vivo platelet aggregation using a previously developed pharmacokinetic (PK)/pharmacodynamic (PD) model.

RESULTS AND DISCUSSION

The antiplatelet effect of low-dose aspirin (81 mg) was predicted to be markedly reduced when ibuprofen (200 mg; the usual prescribed dose in Japan) was administered 1 h or less after aspirin, but not when it was administered more than 2 h after the administration of aspirin. Moreover, the administration of ibuprofen up to 12 h before aspirin completely abrogated the antiplatelet effect of aspirin. When ibuprofen (200 mg) was administered three times daily for 3 days (day 1 to day 3) on a background of continuous low-dose aspirin (81 mg) once daily, 2 h after aspirin, no reduction in the antiplatelet effect of aspirin was predicted on day 1, but a reduction is predicted from day 2, with no return to the initial level until more than 3 days after discontinuation of ibuprofen. A marked reduction in the antiplatelet effect of aspirin was also seen on the same schedule when the dosage of ibuprofen was 150 mg, which is the dose used in over-the-counter (OTC) preparations.

WHAT IS NEW AND CONCLUSION

This study indicates that the antiplatelet effect of low-dose aspirin can be markedly reduced with combined use of ibuprofen, depending on the timing of co-administration. As even the lower OTC dose of ibuprofen (150 mg) was enough to affect the antiplatelet effect of aspirin, health professionals should take into account patients' use of OTC ibuprofen when prescribing low-dose aspirin.

Erythroderma as a paraneoplastic cutaneous disorder in systemic anaplastic large cell lymphoma

BACKGROUND

  Paraneoplastic cutaneous disorders (PCDs) or dermadromes are skin conditions that have an association with internal malignancies but are not themselves malignant. We report the first two cases of systemic anaplastic large cell lymphoma (s-ALCL) accompanied by erythroderma and multiple leg ulcers as PCDs. CASE 1:  A 52-year-old Japanese man presented with disseminated itchy papular erythemas which he had over his entire body for the preceding 5 years that later exacerbated to erythroderma. Multiple punched-out ulcers also developed on his lower legs. Superficial lymph nodes (LNs) were swollen, and a left axillary LN biopsy demonstrated dense CD30(+) atypical large cell (ALC) infiltration. By contrast, lymphocytes infiltrating into the erythroderma and leg ulcers were CD30(-) , and T-cell receptor β (TCRβ) chain gene rearrangement was negative in skin biopsy specimens. Thus, he was diagnosed with s-ALCL. Not only his s-ALCL but also his erythroderma and leg ulcers responded well to chemotherapy. CASE 2:  A 71-year-old Japanese woman presented with erythroderma that persisted for approximately 20 years after mastectomy. At her initial hospital visit, she was diagnosed with s-ALCL by biopsy of swollen left inguinal LNs. Similar to Case 1, CD30(+) ALCs were negative in skin samples with normal TCRβ chain gene rearrangement. As the erythrodermic skin lesion responded well to chemotherapy for s-ALCL, it was considered a PCD.

CONCLUSION

  s-ALCL development may be predicted by the precedence and concurrence of intractable paraneoplastic erythrodermic and ulcerative skin lesions, as reported in our two cases.

Increased circulating Th17 frequencies and serum IL-22 levels in patients with acute generalized exanthematous pustulosis

BACKGROUND/OBJECTIVE

Acute generalized exanthematous pustulosis (AGEP) is a diffuse pustular disorder that usually begins in intertriginous folds with widespread erythema. The causes in the majority of the cases are drugs. T cells and interleukin (IL)-8 play roles in the development of AGEP, but the mechanism remains to be elucidated. We investigated the involvement of Th17 cells and their cytokine IL-22 in the pathogenesis.

METHODS

Three patients with AGEP were enrolled in this study. The percentages of IL-17(+) Th17 cells, interferon γ(+) T cells and IL-4(+) T cells were measured in the patients' peripheral blood lymphocytes by intracellular cytokine staining and flow cytometry. The concentration of IL-22 in the sera was measured by enzyme-linked immunosorbent assay.

RESULTS

The percentages of Th17 cells were markedly higher in all three patients than healthy control individuals. The frequencies of interferon γ(+) T cells were slightly high in the patients compared with the control, and there was no definite tendency in IL-4(+) T-cell frequencies. The concentration of IL-22 was remarkably high in all patients when compared with normal subjects with levels under detection.

CONCLUSION

Th17 cells and their produced cytokine IL-22 were elevated in the peripheral blood of patients with AGEP. As IL-17 and IL-22 cooperatively stimulate keratinocytes to produce IL-8, IL-8 may contribute to the accumulation of neutrophils in the lesional epidermis of AGEP.

Warfarin and miconazole oral gel interactions: analysis and therapy recommendations based on clinical data and a pharmacokinetic model

WHAT IS KNOWN AND OBJECTIVE

Miconazole is a strong inhibitor of CYP2C9, one of the main enzymes involved in the metabolism of warfarin. Concurrent use of the two drugs leads to potentially serious adverse effects. Although it is often assumed that use of the oral miconazole gel is acceptable with concomitant warfarin, because of the low bioavailability following buccal administration, drug-drug interactions have been reported following such use. We aimed to investigate case reports of such interactions and develop a pharmacokinetic model to model such interactions.

METHODS

The Medline database from 1966 to October 2010 was used for literature search. Case reports of the potentiation of the anticoagulant effects of warfarin, such as the elevation of prothrombin time (INR), by concomitant administration of warfarin and miconazole oral gel were collected. We quantitatively estimated the extent of inhibition of warfarin metabolism by orally administered miconazole gel and compared our findings with case reports.

RESULTS AND DISCUSSION

Metabolism of (S)-warfarin is inhibited potently following administration of a standard dose (200-400 mg/day in Japan) of miconazole gel. This may lead to in an increase in the blood concentration of warfarin and lead to serious adverse effects. The literature reports of clinical interactions with concomitant use of those drugs show that other factors may amplify the effects of any increase in blood concentration.

WHAT IS NEW AND CONCLUSION

We summarize all reported, clinically significant, cases of drug interaction between miconazole oral gel and warfarin. Pharmacokinetic modelling shows that concomitant administration of warfarin and miconazole oral gel can lead to substantial increase in warfarin concentration. However, our PK/PD model fails to capture the dramatic increases seen in INR values, and hence bleeding complications, reported in the literature. Taken together, the evidence suggests that concomitant use of miconazole gel and warfarin should be avoided. Even over-the-counter products containing miconazole should be used with caution by patients receiving warfarin.

Development of visual cells in the Pacific bluefin tuna Thunnus orientalis

The development of rod and cone photoreceptor cells was investigated in the retinas of Pacific bluefin tuna larvae and juveniles, using RET-P1 monoclonal antibody labeling to identify photoreceptors. At 60 h after hatching, which was about when feeding began, opsin (presumably green opsin (Rh2)) was expressed in the outer segments of cone cells. At 15 days after hatching (dah), although many labeled cone cells were observed in the dorsal retina, the same type of cone cells had partially appeared in the ventral retina. The presence of rod cell bodies was confirmed by the expression of Rh1 opsin at 15 dah. At 21 dah, the presence of outer segments of rod cells was confirmed by the expression of Rh1 opsin and by morphology. The observations suggest that the cone cells were substantially operable upon the development of their outer segment at around the beginning of the post-larval stage, and the rod cells began to function at around 15 to 21 dah, before and during metamorphosis.

Ontogenetic changes in schooling behaviour during larval and early juvenile stages of Pacific bluefin tuna Thunnus orientalis

Schooling was first observed at 25-27 days after hatching (26. 2-33. 8 mm, total length) in the Pacific bluefin tuna Thunnus orientalis. At this time, the mode of swimming changed from intermittent sprinting to continuous cruising, and this allowed the fish to adjust to an inertial hydrodynamic environment.

In-vivo kinetics of the interaction between midazolam and erythromycin in rats, taking account of metabolic intermediate complex formation

To predict, quantitatively, the extent of drug interaction during repeated administration of a metabolic inhibitor, we analysed the effects of erythromycin treatment under several regimens on the area under the concentration curve (AUC) of midazolam in rats. Midazolam was administered into the portal vein 12 h after erythromycin treatment for 1, 2 or 3 days, or 12, 24, 36, 48, 72 and 96 h after erythromycin treatment for 4 days, and the plasma-concentration profiles of midazolam were analysed to assess the AUC. Moreover, the contents of total cytochrome P450 and inactive metabolic intermediate (MI) complex were simultaneously quantitated. While the AUC value of midazolam was not affected by the administration of erythromycin for 1 day, repeated administration of erythromycin evoked an increase in AUC ratio (AUC in erythromycin-treated rats/AUC in vehicle-treated rats), which reached a maximum value of 1.99 at 12 h after 4 days' treatment with erythromycin. The total content of cytochrome P450 in liver microsomes was unaffected by erythromycin treatment. Although the MI complex was undetectable after 1 day's treatment with erythromycin, its content increased with duration of erythromycin treatment, and the complex disappeared after the end of erythromycin treatment with a half-life of 12.3 h. In conclusion, the interaction between erythromycin and midazolam could be well predicted when the formation of MI complex in the liver was taken into account.