Double-decker cage reduces mount frequency and ejaculation latency, resulting in reduced weight loss in male rats after mating behavior.

Rats were the first mammals to be domesticated for scientific research, and abundant physiological data are available on them. Rats are expected to continue to play an important role as experimental animals, especially with advancements such as CRISPR/Cas9 technology. Environmental enrichment aims to promote species-specific behaviors and psychological well-being. In the present study, we designed a double-decker (DD) cage, which utilizes two stacked plastic cages for rat enrichment, and investigated the influence of housing in the DD cage on rat mating behavior. The results indicated that mount frequency, total mount counts, and total ejaculation latency were significantly lower in the DD cages than in the single-decker (SD) cages. Notably, in the DD cages, the body weight loss of male rats after mating behavior was lower than that observed in the SD cage. Water consumption per day during mating behavior was also significantly lower in the DD cages, although no significant differences were observed in daily food intake during mating behavior. In addition, reproductive performance, including pregnancy rate and birth rate, did not change in the DD cages. In summary, our study demonstrated that DD cages reduce mount frequency and ejaculation latency during rat mating, resulting in decreased water consumption and weight loss in male rats. Therefore, housing in DD cages may serve as a beneficial enrichment for rats.

[Effect of Water Intake on Allergy-like Events Associated with Non-ionic Iodine Contrast Agents].

The use of iodine contrast agents occasionally causes serious allergic symptoms including anaphylaxis. At Kyoto University Hospital to prevent nephropathy we began recommending water intake before and after administration of iodine contrast agents in September 2012. In the present study we investigated the effect of water intake on the incidence of allergy-like events after the use of non-ionic iodine contrast agents. We extracted the occurrence of allergy-like events from the incident report system in our hospital from January 2011 to September 2014, and classified these events into the following 3 grades: 1+ (follow-up); 2+ (medication treatment); and 3+ (hospitalization). The allergy-like incidence rate was calculated for subsequent evaluation according to season and water intake. Allergy-like events significantly decreased from 0.49% before the recommendation of water intake to 0.26% at 1 year and 0.20% at 2 years after implementing the recommendation. The incidence of allergy-like events was significantly higher in summer than in winter before water intake was recommended. After implementing the recommendation, the value for summer significantly decreased to an incidence similar to that of winter. Respiratory and gastrointestinal allergy-like symptoms were dramatically decreased after implementing the recommendation. Water intake may be useful for preventing allergy-like events associated with non-ionic iodine contrast agents, especially during the summer.

Comparison of the effects of azole antifungal agents on the anticoagulant activity of warfarin.

The package insert of the antithrombotic agent warfarin warns users of its interaction with azole antifungals. However, information on the frequency or degree of these interactions is limited. In particular, the time to onset of azole-mediated prothrombin time prolongation, expressed as the international normalized ratio (INR), is poorly characterized. Therefore, we retrospectively examined the INR in 29 patients administered warfarin with fluconazole (FLCZ), voriconazole (VRCZ), or itraconazole (ITCZ). INRs in 18 patients taking FLCZ and in 5 patients taking VRCZ significantly increased from 1.40 to 2.94 and from 1.95 to 2.89, respectively. The warfarin sensitivity index (WSI), calculated as INR/daily warfarin dose, also significantly increased from 1.06 to 1.89 with FLCZ and showed an upward trend from 1.13 to 2.23 with VRCZ. ITCZ had no influence on the INR or WSI in 6 patients. The INRs observed when warfarin was coadministered with azoles (Y) correlated significantly with those observed in the absence of azoles (X): FLCZ, Y=4.94X-3.96, r(2)=0.80; VRCZ, Y=2.13X-1.27, r(2)=0.93. Moreover, in all 8 patients with closely monitored INRs, the WSI increased within 1 week of FLCZ or VRCZ coadministration. In conclusion, FLCZ and VRCZ augmented the anticoagulant activity of warfarin. The INR should be closely monitored within 1 week of initiating FLCZ or VRCZ coadministration with warfarin, especially in patients with high INRs.

Increased inhibition and decreased facilitation effect during a lexical decision task in children.

Widespread theories propose that implicit memory is established in the early stages of development, while explicit memory continues to develop until later stages. However, recent studies have argued that implicit memory changes developmentally. In order to elucidate the differences of implicit memory and semantic memory structures between children and adults, a single-word presentation method was developed using lexical decision tasks in which repeated real words, related real words, unrelated real words and pseudowords were presented in a list. Semantic priming and repetition priming using a single-word presentation method were employed in 25 children and 18 adults. Reaction time (RT) and correct rate for real words following pseudowords served as the base. Inhibition effect was defined as an increase in RT between a real word preceded by an unrelated real word and a real word preceded by a pseudoword. Facilitation effect was defined as a decrease in RT between a real word preceded by a related real word and a real word preceded by a pseudoword. Although the effect sizes of semantic priming did not differ between children and adults, the inhibition effect was larger and the facilitation effect was smaller in children. Repetition priming in children did not differ from that in adults. These findings challenge the idea of developmental invariance in implicit memory, suggesting that the strength of links between nodes in the semantic network increases and the range of spreading activation expands developmentally.