A survey of antimicrobial resistance in Escherichia coli isolated from wild sika deer (Cervus nippon) in Japan

We examined the antimicrobial susceptibility of 848 Escherichia coli isolates from 237 feces samples of wild sika deer (Cervus nippon) captured between 2016 and 2019 in 39 of the 47 prefectures of Japan. Five of the 237 wild sika deer (2.1%) carried E. coli with resistance to at least one antimicrobial, and all the resistant isolates showed resistance to tetracycline. The resistant isolates contained antimicrobial resistance genes that were similar to those in E. coli derived from humans and farm animals. Although wild sika deer are not currently likely to be a source for the transmission of antimicrobial resistance in Japan, they can potentially mediate antimicrobial resistance spread by coming into contact with humans, animals, and their surroundings.     

The influence of barley malt protein modification on beer foam stability and their relationship to the barley dimeric alpha-amylase inhibitor-I (BDAI-I) as a possible foam-promoting protein

The foam stability of beer is one of the important key factors in evaluating the quality of beer. The purpose of this study was to investigate the relationship between the level of malt modification (degradation of protein, starch, and so on) and the beer foam stability. This was achieved by examining foam-promoting proteins using two-dimensional gel electrophoresis (2DE). We found that the foam stability of beer samples brewed from the barley malts of cultivars B and C decreased as the level of malt modification increased; however, the foam stability of cultivar A did not change. To identify the property providing the increased foam stability of cultivar A, we analyzed beer proteins using 2DE. We analyzed three fractions that could contain beer foam-promoting proteins, namely, beer whole proteins, salt-precipitated proteins, and the proteins concentrated from beer foam. As a result, we found that in cultivar A, some protein spots did not change in any of these three protein fractions even when the level of malt modification increased, although the corresponding protein spots in cultivars B and C decreased. We analyzed these protein spots by peptide mass finger printing using matrix-assisted laser desorption/ionization time-of-flight mass spectrometry. As a result, all of these spots were identified as barley dimeric alpha-amylase inhibitor-I (BDAI-I). These results suggest that BDAI-I is an important contributor to beer foam stability.     

Spontaneous well-differentiated pancreatic islet cell carcinoma with vascular invasion in a male F344 rat

This case report describes a case of spontaneous pancreatic islet cell carcinoma with vascular invasion in a 110-week-old male F344 rat. Histologically, a pancreatic nodule consisting of tumor cells and many blood-rich vessels, and covered with a fibrous capsule showed local invasion in the capsule and adjacent acinar tissues, encircling a large duct-like structure (DS). The tumor was composed of well-differentiated tumor cells resembling normal pancreatic islet cells, which had small round nuclei and eosinophilic cytoplasm. Mitotic figures were rare. Immunohistochemistry revealed that the tumor cells were positive for insulin. Although endothelial cells were not detected, the DS wall showed cells positive for α-smooth muscle actin and elastic fibers, suggesting that the DS is the pancreatic artery. This is a rare case of islet cell carcinoma consisting of well-differentiated tumor cells with invasion of the pancreatic artery in a rat.     

Malignant pinealoma observed in the deep cerebral parenchyma of a male Wistar rat

This report describes a case of spontaneous malignant pinealoma in a 90-week-old male Wistar rat. The tumor mass occurred in the deep cerebral parenchyma and no intact pineal gland was observed in the area between the posterior-dorsal median line of the cerebrum and the cerebellum. The tumor was characterized by a large nodular proliferation occupying the central area of the brain, extending from the dorsal surface to the base of the brain, corresponding to the thalamus. The tumor cells had round to irregular oblong nuclei approximately 5–17 μm in diameter and showed faintly or moderately eosinophilic cytoplasm and indistinct cell boundaries. Immunohistochemically, the tumor cells were positive for synaptophysin and partially positive for neuron-specific enolase (NSE). The tumor showed malignant features including cellular pleomorphism, high mitotic index, necrotic foci, and invasive and extensive growth and was, therefore, diagnosed as an extremely rare malignant pinealoma in the deep cerebral parenchyma.     

A possible critical dosing period of p-cumylphenol for development of cystic kidneys in rat neonates

In accordance with a previous report on cystic kidneys induced in rat neonates when dosed with p-cumylphenol (PCP) for 18 days from postnatal day (PND) 4, 3 rat neonates were dosed with PCP once a day for 14 days, either from PND 14, 21, 28, 35, or 42 as W2, W3, W4, W5, and W6 groups, respectively, to investigate whether dosing periods in different PNDs influenced the development of cystic renal tubules. The lesion was striking in the W2 group and at a lesser magnitude in the W3 group, whereas either kidney was unaffected when dosing was initiated beyond PND 28. These findings, together with the results from the previous study, suggested that PND 14-28 is a critical dosing period for PCP to develop cystic kidneys in rat neonates. The lining epithelium of the cystic tubules was immunohistochemically positive for AQP2. This finding and the anatomical location indicated that the cystic tubules were of collecting duct origin. Either obstruction, fluid accumulation, or reparative hyperplasia of the lining epithelium was unlikely to be involved in the formation of cystic tubules lined with a monolayer of cuboidal or columnar epithelium with a high nuclear density. Thus, the follow-up investigation on PCP suggested a critical dosing period of PND 14-28 in rat neonates for the development of cystic dilation of renal collecting ducts. This study further supports that additive hyperplasia of the lining epithelium is a fundamental basis of this unique lesion.     

Ontogeny of testicular inhibin and activin in ducks: An immunocytochemical analysis

The ontogeny of testicular inhibin/activin in ducks was investigated. Testicular localization of three inhibin/activin subunits (α, β_A and β_B) was determined in embryonic and newly hatched ducks from 12 days of incubation to 1 day of age, in immature ducks and in adult ducks. In the duck embryonic testis, positive α‐subunit immunostaining was first detected in the Leydig cells and Sertoli cells on day 15 of incubation, whereas β_A‐subunit and β_B‐subunit immunostaining were found in Sertoli cells and primary germ cells on day 18 of incubation. In 1 month old ducks, intense staining of α‐subunit was present in the seminiferous epithelium consistent with localization in Sertoli cells and primary germ cells, and the immunostaining of the β_A‐ and β_B‐subunit was also present in Sertoli cells and primary germ cells. Specific immunostaining with inhibin/activin α‐, β_A‐ and β_B‐subunits antisera occurred in Sertoli cells in the adult duck testes. In conclusion, it was shown that, in the duck testis, the majority of α‐, β_A‐ and β_B‐subunits are colocalized in Sertoli cells with a certain degree of staining in germ cells and the α‐subunit is present in Leydig cells of embryonic testes before day 18 of incubation. These results indicate that Sertoli cells and possibly germ cells in the embryonic testes of late stage of incubation and newly hatched ducks, immature ducks and mature ducks may produce bioactive inhibin dimers, inhibin A and inhibin B, as a possible regulator of follicle‐stimulating hormone secretion. Free inhibin/activin subunits and their dimers may also play an autocrine/paracrine role in the development of the testis and spermatogenesis. Furthermore, early onset of the α‐subunit in duck testes indicates that it may have an autocrine/paracrine effect on steroid hormones, which is important for sex differentiation.     

Microbiota of 'airag', 'tarag' and other kinds of fermented dairy products from nomad in Mongolia

The traditional fermented dairy products were collected from three nomadic families in Donto‐Govi prefecture in Mongolia (central Mongolia), and those microbiota were analyzed. These samples consist three of ‘airag’, two of ‘tarag’, two of ‘isgelen tarag’ and ‘qoormog’, and some cheeses. In airag, Lactobacillus (L.) helveticus, L. kefiri, and Saccharomyces (S.) dairensis were common, and L. paracasei, L. plantarum, L. farciminis, S. cerevisiae, Issachenkia (I.) orientalis, Kluyveromyces (K.) wickerhamii were also found. In tarag, isgelen tarag and qoormog, L. helveticus, L. kefiri, L. fermentum, L. paracasei and L. acetotolerance were found. L. delbrueckii subsp. bulgaricus was also found in one tarag and one qoormog samples. Randomly amplified polymorphic DNA (RAPD) analysis showed that there were diversity in each L. helveticus family and products, and there were common strains found in airag and tarag in the same family.     

TGF-β and TNF-α stimulate MMP-9 production in murine epidermal keratinocytes

Matrix metalloproteinases 2 and 9 (MMP‐2 and ‐9) are zinc‐dependent metalloenzymes and have gelatin‐degrading activity. Both MMP are known to be secreted by many types of cells and play important roles in several biological changes including tissue remodeling and wound healing. In the present study, a primary culture of murine epidermal keratinocytes was prepared and effects of transforming growth factor‐β (TGF‐β), tumor necrosis factor‐α (TNF‐α) and interferon‐γ (IFN‐γ) on expression of MMP‐2 and MMP‐9 by the keratinocytes was examined. Gelatin zymography revealed that murine epidermal keratinocytes secreted proenzyme forms of MMP‐2 and MMP‐9, but the active forms of both MMP were hardly detectable, indicating that in vitro autoactivation of these proenzymes did not occur. Both TGF‐β and TNF‐α stimulated MMP‐9 production in a dose‐dependent manner, but the MMP‐2 level was not changed. Interferon‐γ hardly affected production of MMP‐2 or MMP‐9. Ribonuclease protection assay demonstrated that TNF‐α increased the level of MMP‐9 mRNA 6‐fold compared to the control, whereas TGF‐β slightly up‐regulated it. These results suggest that expression of MMP‐9 could be regulated by several cytokines in murine epidermal keratinocytes.