Molecular Epidemiological Analysis of the Spreading Conditions of Trichophyton in Long-Term Care Facilities in Japan.

Tinea pedis and tinea unguium are common infectious diseases, and many elderly people are reported to contract these infections. In this study, to investigate whether strains of the same origin are spreading inside a long-term care facility, we analyzed Trichophyton rubrum and Trichophyton mentagrophytes, isolated from the residents and staff at the facilities located in the Kanto area, using a genomic analytical method targeting tandem repeat regions in the nontranscribed spacer (NTS) region of ribosomal DNA. Five NTS types were confirmed in T. rubrum. T. rubrum of various types (types 1 to 5) was detected at each facility, but there was no isolate specific to one facility only. Eight NTS types of T. mentagrophytes were detected, and T. mentagrophytes that carried an NTS type that was confirmed at one facility only (types C4II, F4II, and D4II) was isolated. These T. mentagrophytes sequence types were isolated from several subjects residing at the same facility. This study proved that a T. mentagrophytes strain of the same type had spread in long-term care facilities. We believe in the importance of cleaning at a long-term care facility as a countermeasure to the spread of Trichophyton species.

Discovery of Terbinafine Low Susceptibility Trichophyton rubrum strain in Japan.

This is the first confirmed report of terbinafine low susceptibility Trichophyton rubrum, BGUTR13, in Japan collected from the whole sole of the elderly over 65s with cotton swab sampling method at the special nursing care-home in 2016. We revealed BGUTR13 showed low susceptibility (MIC, >128 µg/mL) against terbinafine. But, BGUTR13 exhibited normal susceptibility to itraconazole, did not showed cross-resistance. Also, the squalene epoxidase gene of terbinafine low susceptibility strain BGUTR13 which is the target of terbinafine contained newly confirmed one mismatch. We suggested the possibility that the resistance mechanism of terbinafine low susceptibility strains is due to the loss of sensitivity of squalene epoxidase inhibitors and does not affect antifungal drugs with other different mechanisms of action.

Epidemiological Study on Trichophyton Disseminating from the Feet of the Elderly.

OBJECTIVES: To grasp the colonization status of Trichophyton in terms of spreading rate, we investigated the intergenerational epidemiological difference in the spreading rate of Trichophyton from teenagers to the elderly aged over 65. In addition, the elderly people were divided into two groups: those living at nursing homes and those living at their homes. We compared the two groups in terms of the difference in the spreading rate of Trichophyton. METHODS: Spreading rate was investigated by identifying the fungi collected by the cotton swab sampling method. The correlation between the responses to the questionnaire survey, which was conducted after the sample collection, and the spreading rate of Trichophyton was analyzed. RESULTS: The spreading rate of Trichophyton was 23.3%. It was confirmed that the spreading rate in general adults was 9.1%, whereas that in elderly people was 40.8%, which is significantly high. Also, it was confirmed that T. mentagrophytes shows a higher spreading rate among general adults, whereas T. rubrum shows a higher spreading rate among the elderly. Between the elderly living at nursing homes and those living at their homes, although no statistically significant difference was confirmed, the former tended to show a higher spreading rate than the latter. Also, the results of this study showed that spreading rate of Trichophyton and the detachment of the skin of the toes were significantly related. CONCLUSIONS: We found that the risk of spreading of Trichophyton increases with age. Particularly among elderly people aged over 65, taking some actions that prevent the spread of tinea pedis is recommended.

Age-dependent changes in the kidney morphology of female DBA/2 mice.

A female DBA/2 mouse is characterized by the presence of abundant cytoplasmic granules in the renal tubules. In the present study, the morphometrics of kidneys from female DBA/2 mice at 5, 15, 18, 21, and 24 months of age were investigated to determine the age-dependent renal changes in this mouse strain. Glomerular and tubulointerstitial disease progressed with age, and the semiquantitative scores of these lesions showed significant increases. Granules were observed in the proximal straight tubules and no changes were observed in their localization, fine structure, and quantitative scores. It was concluded that the tubular cytoplasmic granules in the female DBA/2 mouse were not affected by age-dependent functional reduction of the kidney.

Immunohistochemical localization of renin, NO synthase-1, and cyclooxygenase-2 in rodent kidney.

The renin-angiotensin system (RAS) and tubuloglomerular feedback (TGF) are central to the maintenance of blood pressure and body fluid composition. Renin, NO synthase-1 (NOS-1), and cyclooxygenase-2 (COX-2) are key regulators of the RAS and TGF. In the present study, to investigate species-specific differences in the RAS and TGF, we immunohistochemically and morphometrically investigated the localization of renin, NOS-1, and COX-2 in the kidneys of various laboratory rodents and comparing males with females (DBA/2Cr mice, F344/N rats, Syrian hamsters, MON/JmsGbs gerbils and Hartley guinea pigs). In all animals, renin-positive immunoreactions were observed in the vascular walls of afferent arterioles. Renin immunoreactions appeared to be more widely distributed in mice. Mice had a greater number of renin-positive arterioles than other species. NOS-1-positive reactions were detected in the macula densa (MD) of all animals. Mice had the greatest number of NOS-1-positive MD cells. In addition to NOS-1-positive reactions, COX-2-positive reactions were observed in the MD of mice, rats, hamsters and gerbils. Interestingly, guinea pigs had no COX-2-positive MD cells. Rats had the greatest number of COX-2-positive MD cells. In nephron segments excluding the MD, the immunohistochemical localization of NOS-1 and COX-2 differed markedly among not only species but also sexes within the same species. In conclusion, we determined that localization of renin, NOS-1, and COX-2 showed large species- and sex-related differences. These data suggest that the regulation mechanisms of the RAS and TGF via renin, NOS-1, and COX-2 differ among rodents.

Skin morphology of the Clawn miniature pig.

Skin morphology of the Clawn miniature pig (CMP) was investigated at the axilla, medial thigh, back and loin. The mean thickness of the epidermis (excluding the corneal layer), the mean number of layers of keratinocytes comprising the epidermis and the mean height of keratinocytes were assessed morphometrically. When observed under a light microscope, the skin of the CMP resembled human skin. Morphometrically, skin from the back and loin of the CMP most resembles human skin. Electron microscopic observations revealed sparse but typical Birbeck granules in the epidermal Langerhans cells of the CMP. The results of the present study indicate that CMP skin is potentially useful as a model for human skin.

Strain differences in morphometrical characteristics of rat kidneys.

To clarify the strain differences in the morphology of the rat kidneys, we investigated the morphometrical characteristics of the kidneys of Slc:Wistar, Slc:SD, and F344/NSlc rats. The diameter of the renal corpuscles in female F344/N rats is smaller than that in female Wistar rats. Although sex differences (males>females) were shown in SD and F344/N rats, no effects of castration were detected in any of the groups. Strain-dependent differences in the percentage of renal corpuscles with a cuboidal parietal layer were found in both male and female groups. The highest percentage of them was noted in male Wistar rats. Effects of castration were observed in female Wistar and male F344/N rats, and the values after castration were significantly higher than those in the intact animals. As for the number of proximal convoluted tubular nuclei, no strain differences were detected in either the male or female groups. Although a sex difference was found in SD rats (female>male), no effects of castration were detected in any of the groups. In female F344/N rats, numerous numbers of PAS-positive granules, which were observed in the proximal convoluted and straight tubular epithelia, were noted. Orchiectomy induced an increase of these granules in male SD and F344/N rats, but ovariectomy showed no effects on them in any strains. This is the first study to clarify the strain differences in the morphological characteristics of the kidneys in ordinary rat strains.

Species specific differences in the ratio of short to long loop nephrons in the kidneys of laboratory rodents.

The ratio of short to long loop nephrons (SLNs and LLNs, respectively) in laboratory rodents (mice, rats, hamsters, gerbils, and guinea pigs) was investigated using the air cast method. In mice and rats, the percentage of SLNs was significantly higher than that of LLNs, while in hamsters and gerbils, the reverse was true (% of LLNs >% of SLNs). In guinea pigs, no significant difference in the percentages of LLNs and SLNs was noted.

Morphometric study of gender differences with regard to age-related changes in the C57BL/6 mouse kidney.

To investigate gender differences with regard to age-related changes in the mouse kidney, kidneys from male and female C57BL/6Cr mice were morphometrically examined at 2, 4, 12, 27 and 33 months of age. Gender differences were clearly observed in age-related changes in renal corpuscle diameter, in addition to semiquantitative scores of glomerular damage and interstitial fibrosis. A greater relative increase in renal corpuscle diameter was observed in females compared to males, and scores indicating glomerular damage and interstitial fibrosis were more severe in males than in females.

Rodent renal structure differs among species.

In the present study, we histologically and morphometrically investigated species differences in renal structure using laboratory rodents (mice, gerbils, hamsters, rats, and guinea pigs). Morphometric parameters were as follows, 1) diameter of the cortical renal corpuscles, 2) diameter of the juxtamedullary renal corpuscles, 3) percentage of the renal corpuscles with a cuboidal parietal layer, 4) number of nuclei in proximal convoluted tubules (PCTs) per unit area of cortex, 5) semi-quantitative score of the periodic acid-Schiff (PAS) -positive granules in PCTs, and 6) semi-quantitative score of the PAS-positive granules in proximal straight tubules (PSTs). Significant species differences were detected for each parameter, and particularly severe differences were observed in the PAS-positive granules of PCTs and PSTs. Granular scores varied among species and sexes. Vacuolar structures that did not stain with PAS or hematoxylin-eosin were observed in the renal proximal tubules. The appearance and localization of these vacuolar structures differed remarkably between species and sexes.

Immunohistochemical localization of ghrelin in rodent kidneys.

Ghrelin is a novel peptide hormone, originally identified in the rat and human stomach that plays various important roles. In the present study, we report the intra-renal localization of ghrelin in laboratory rodents. Kidneys from 3 month-old mice, rats and hamsters of both sexes were analyzed by immunohistochemistry. Positive signals were clearly observed in the epithelium of the distal tubules, whereas other segments of the nephron or interstitial cells, including juxtaglomerular cells, showed negative reactions. Pre-embedding immunoelectron microscopy revealed positive signals exclusively on the basolateral membrane in the distal tubular cells and in the collecting ducts. In addition, prepro-ghrelin gene expression was assessed by RT-PCR, and the expected 329-bp prepro-ghrelin mRNA was clearly detected in the kidney. On Western blot analysis, although a specific band for ghrelin (3 kDa) was not detected in the kidney, the expected band for prepro-ghrelin (13 kDa) was clearly detected in both the stomach and the kidney. This paper clarified the intra-renal localization of ghrelin.

Neuronal nitric oxide synthase and cyclooxygenase-2 in diabetic nephropathy of type 2 diabetic OLETF rats.

Neuronal nitric oxide synthase (nNOS) and cyclooxygenase-2 (COX-2) regulate the tubuloglomerular feedback (TGF) and renin-angiotensin system (RAS) in the kidney. In type 1 diabetic rats, renal overproduction of these enzymes and their relationship to the pathogenesis of diabetic nephropathy has been demonstrated. In the present study, we histologically and immunohistochemically investigated the kidneys of Otsuka Long-Evans Tokushima Fatty (OLETF) rats, as a model of type 2 diabetes, at 62 weeks of age (chronic phase of diabetes). The kidneys of OLETF rats showed typical diabetic nephropathy. Quantitative scores for glomerulosclerosis and interstitial fibrosis in OLETF rats were significantly higher than those of age-matched control Long-Evans Tokushima Otsuka (LETO) rats. nNOS- and COX-2-positive immunoreactions were observed in the distal tubules and collecting ducts. These reactions appeared to be more widely distributed in OLETF, and the number of nNOS-and COX-2-positive sites in the OLETF were significantly more than those in LETO rats. Expression of renin, angiotensin II, and inducible nitric oxide synthase (iNOS) were also examined immunohistochemically, and no differences between OLETF and LETO rats were observed in the distributions and the number of immunoreactive-sites. In conclusion, the overproduction of nNOS and COX-2 in the kidney of OLETF rats was confirmed, suggesting that the overproduction of nNOS and/or COX-2 does not affect the intrarenal RAS or iNOS production but does affect TGF.

Development of gender differences in DBA/2Cr mouse kidney morphology during maturation.

Although we recently clarified sex-based differences in mouse kidney morphology, the developmental processes responsible for these gender differences during maturation remain unclear. The present study analyzed the morphometry of kidneys from 20-, 30-, 50-, 60-, 70-, 90-, 120- and 150-day-old DBA/2Cr mice. Total kidney weight and ratio of kidney weight to body weight were larger in males than females beginning at 50 days of age. The percentage of renal corpuscles exhibiting a cuboidal parietal layer was higher in males than in females in the 70-day and older mice. The diameter of cortical renal corpuscles was larger in males than in females beginning on day 90. The number of proximal convoluted tubular cell nuclei was higher in females than in males from day 90 onward. Vacuolar structures in the proximal convoluted tubular epithelium became prominent in 70-day-old males. PAS-positive granules in the proximal straight tubular epithelium became prominent in females on day 50. This paper is the first to describe the development of gender differences in mouse kidney morphology.

The effects of aging and treadmill running on soleus and gastrocnemius muscle morphology in the senescence-accelerated mouse (SAMP1).

We investigated the effects of aging on the soleus and gastrocnemius muscles in male SAMP1 (senescence-accelerated mouse prone 1). Body mass, muscle wet weight, fiber size, and the percent of type II fibers declined from 50 weeks of age. Voluntary motor behavior also significantly declined with age. Furthermore, we examined the effects of high (twice daily) and low (once daily) frequency treadmill running, for 6 weeks at 5 days per week, beginning when the mice were 50 weeks old. Muscle fiber size for the high frequency running significantly increased. Pathological fiber alterations in these mice were increased by running, especially by high frequency running. This suggests that age-related muscle morphological changes in SAMP1 occurs from 50 weeks of age, and that the decline in voluntary motor behavior is an important factor in aging muscle atrophy. In addition, high frequency running is more beneficial for aged muscle hypertrophy. This model is useful for studying the acceleration of the aging process in skeletal muscle of the SAM.

Age-related changes in expression of transforming growth factor-beta and receptors in cells of intervertebral discs.

OBJECT: The authors conducted a study to determine age-related changes in expression of transforming growth factor (TGF)-beta1, -beta2, -beta3, and Type I and Type II receptors in various cells in the nucleus pulposus and anulus fibrosus. Immunolocalization of TGFbetas and Type I and II receptors was examined during the aging process of cervical intervertebral discs in senescence-accelerated mice (SAM). The TGFbeta family has important roles for cellular function of various tissues. Its role in disc aging, however, is unknown. Detailed information on the temporal and spatial localization of TGFbetas and their receptors in discs is required before discussing introduction of them clinically into the intervertebral disc. METHODS: Three groups of five SAM each were used. The groups of SAM were age 8, 24, and 50 weeks, respectively. Hematoxylin and eosin staining and immunohistochemical study involving specific antibodies for TGFbeta1, -beta2, -beta3, and Types I and II TGF receptors were performed. Intervertebral discs exhibited degenerative change with advancing age. The TGFbetas and their receptors were present in the fibrocartilaginous cells within the anulus fibrosus and notochord-like cells within the nucleus pulposus of young mice. Expression of TGFbetas and Type I and Type II receptors changed markedly in the cells within the anulus fibrosus during the aging process. CONCLUSIONS: The TGFbetas and their receptors were present in cells within the nucleus pulposus and the anulus fibrosus of young mice, and their expression decreased with age.