Influx and efflux transport of H1-antagonist epinastine across the blood-brain barrier.

We investigated influx and efflux transporters involved in blood-brain barrier transport of the nonsedative H1-antagonist epinastine. The basal-to-apical transport of [14C]epinastine was markedly higher than that in the opposite direction in LLC-GA5-COL150 cells stably transfected with human multidrug resistance (MDR)1 gene. The brain-to-plasma concentration ratio of [14C]epinastine in mdr1a/b(-/-) mice was 3.2 times higher than that in wild-type mice. The uptake of both [3H]mepyramine and [14C]epinastine into immortalized rat brain capillary endothelial cells (RBEC)1 showed temperature and concentration dependence. The kinetic parameters, K(m), V(max), and uptake clearance (V(max)/K(m)), of the initial uptake of [3H]mepyramine and [14C]epinastine by RBEC1 were 150 microM, 41.8 nmol/min/mg protein, and 279 microl/min/mg protein for mepyramine and 10.0 mM, 339 nmol/min/mg protein, and 33.9 microl/min/mg protein for epinastine, respectively. The uptake of [3H]mepyramine and [14C]epinastine by RBEC1 was inhibited by organic cations such as quinidine, amantadine, and verapamil, but not by other organic cations, tetraethyl ammonium, guanidine, and carnitine. Organic anions such as benzoic acid, estrone-3-sulfate, taurocholate, and neutral digoxin were not inhibitory. Furthermore, some cationic H1 antagonists (chlorpheniramine, cyproheptadine, ketotifen, and desloratadine) inhibited the [3H]mepyramine and [14C]epinastine uptake into RBEC1. In conclusion, the present study demonstrated that the combination of efficient efflux transport by P-glycoprotein and poor uptake by the influx transporter, which is identical with that responsible for the uptake of mepyramine, account for the low brain distribution of epinastine.     

Histopathological studies of microtubule disassembling agent-induced myocardial lesions in rats

Microtubule disassembling agents (MDAs) such as colchicine (COL) and vincristine sulfate (VCR) are known to be cardiotoxic. However, few attempts have been made to histopathologically examine cardiac lesions induced by MDAs. In this study, we endeavored to induce myocardial injury in rats by administering MDAs and to clarify the morphological features of these myocardial lesions. Male rats were intravenously administered COL (1.00 or 1.25 mg/kg for 2 days at single daily doses) or VCR (0.50 or 0.75 mg/kg for 2 days at single daily doses). The day after administration, hearts were excised and examined histopathologically, immunohistochemically and electron microscopically. Degeneration and necrosis of myocardial cells with vacuolation were observed in rats administered COL at 1.25 mg/kg or VCR at 0.75 mg/kg. Electron microscopic examination revealed vacuoles in swollen mitochondria. Moreover, there were cells showing pyknosis and karyorrhexis in the interstitium. TUNEL and immunohistochemical staining for endothelial cells and electron microscopic examination identified the apoptotic cells in the interstitium to be vascular endothelial cells. These vascular endothelial lesions were induced by lower doses of MDAs than were myocardial lesions. Furthermore, common sites of cardiac lesions induced by MDAs had almost the same distribution as areas positive for pimonidazole, a marker of hypoxia. These findings indicate that MDAs occasionally damage mitochondria in myocardial cells, and suggest that these changes involve microcirculatory dysfunction induced by endothelial cell injury.     

The impact of traumatic brain injury on family members living with patients: a preliminary study in Japan and the UK

Purpose: To ascertain the views of families living with TBI patients about the nature of the problems experienced as a result of TBI, and to compare the views of Japanese family members (J-FM) and British family members (B-FM) in order to find out whether there were cultural differences in family response to TBI. Methods: Family members involved in providing care were identified by the patients. Face to face interviews were conducted with all 18 carers in B-FM and four carers in J-FM. The remaining eight carers in J-FM participated in the postal questionnaire. Questionnaires were developed to explore the nature of problems and the involvement of family such as social embarrassment. Results: Problems arising in families were almost the same reported from both groups. However families in B-FM were likely to know more about how to cope with these problems. Family members in J-FM reported more statistically significant increases in social embarrassment than those in B-FM. Conclusion: The preliminary results showed that family members living with TBI patients in both groups had experienced problems. Appropriate rehabilitation services should be developed to help families as well as TBI patients in Japan.     

Effect of prosthetic restoration on masticatory function in patients with shortened dental arches: a multicentre study

The aim of this multicentre study was to investigate the effect of prosthetic restoration for missing posterior teeth on mastication in patients with shortened dental arches (SDAs). Partially dentate patients who had an intact teeth in anterior region and missed distal molar(s) (2–12 missing occlusal units) classified as Kennedy Class I or Class II were recruited from seven university‐based dental hospitals in Japan. Of the 125 subjects who underwent baseline (pre‐treatment) and follow‐up/post‐treatment evaluation, 53 chose no replacement of missing teeth and 72 chose treatment with removable partial dentures (n = 53) or implant‐supported fixed partial dentures (n = 19). Objective masticatory performance (MP) was evaluated using a gummy jelly test. Perception of chewing ability (CA) was rated using a food intake questionnaire. In the no‐treatment group, mean MP and CA scores at baseline were similar to those at follow‐up evaluation (P > 0·05). In the treatment group, mean MP after treatment was significantly greater than the pre‐treatment mean MP (P < 0·05). However, the mean perceived CA in the treatment groups was similar at pre‐ and post‐treatment (P > 0·05). In a subgroup analysis of subjects in the treatment group, subjects with lower pre‐treatment CA showed a significant CA increase after treatment (P = 0·004), but those with higher pre‐treatment CA showed a significant decrease in CA (P = 0·001). These results suggest that prosthetic restoration for SDAs may benefit objective masticatory performance in patients needing replacement of missing posterior teeth, but the benefit in subjective chewing ability seems to be limited in subjects with perceived impairment in chewing ability before treatment.     

High calcium enhances the expression of double‐stranded RNA sensors and antiviral activity in epidermal keratinocytes

Double‐stranded RNA (dsRNA) sensors including TLR3, MDA5 and RIG‐I are expressed in epidermal keratinocytes and play an important immunological role by enhancing various innate and adaptive immune responses. Although the role of elevated extracellular calcium concentration in keratinocyte differentiation is well understood, the effect of high calcium on dsRNA sensors is not well studied. We investigated alterations in dsRNA sensor expression and antiviral activity induced by a high extracellular concentration of calcium in epidermal keratinocytes. Normal human epidermal keratinocytes (NHEKs) were stimulated with high calcium and/or synthetic dsRNA, poly (I:C). TLR3, IFIH1 (MDA5) and DDX58 (RIG‐I) expression were measured via qPCR, and IFN‐β and human beta‐defensin 2 (HBD2) levels were measured using ELISA. TLR3 localization was evaluated with immunocytofluorescence. Antiviral activity was quantified with virus plaque assays using herpes simplex virus type 1 (HSV‐1). High calcium significantly upregulated mRNA expression of TLR3, IFIH1 and DDX58 in NHEKs. In addition, high calcium significantly enhanced poly (I:C)‐induced anti‐HSV‐1 activity in NHEKs. The antiviral molecule HBD2 but not IFN‐β induction by poly (I:C) was enhanced by high calcium. Our findings indicate that high levels of extracellular calcium enhance the expression of dsRNA sensors and augment antiviral activity in epidermal keratinocytes.