Journal of Veterinary Medical Science
Online ISSN : 1347-7439
Print ISSN : 0916-7250
ISSN-L : 0916-7250
77 巻 , 7 号
July
選択された号の論文の24件中1~24を表示しています
Avian Pathology
  • Kikuyasu NAKAMURA, Hideo FUJIMORI, Akiko KOYAMA, Trinh Quang DAI, Kuni ...
    2015 年 77 巻 7 号 p. 837-841
    発行日: 2015年
    公開日: 2015/08/01
    [早期公開] 公開日: 2015/03/29
    ジャーナル フリー
    Four doves (Nos. 1–4 birds) affected with neurological signs (ataxia, circling and torticollis) were investigated pathologically and microbiologically. Viral isolation was tried from the tracheal and cloacal swabs of all 4 birds and from liver, spleen, kidney, heart, lung and brain of Nos. 1 and 2 birds. No viruses were isolated from 4 birds, but they had high serum antibody titers against avian paramyxovirus 1 (APMV-1). Histologically, they had the characteristic histological changes of pigeon APMV-1 infection; nonpurulent encephalitis and interstitial nephritis. Immununohistochemically, APMV-1 antigens were detected in the necrotic renal tubular epithelial cells of 1 bird of them (No. 3 bird). Detection of APMV-1 ribonucleic acid (RNA) from formalin-fixed and paraffin-embedded (FFPE) sections was attempted by reverse transcription-polymerase chain reaction (RT-PCR). Sequencing the RT-PCR product showed the virus RNA belonged to the same APMV-1 genotype (VI) as the strains isolated from the world previous cases of pigeon APMV-1 infection. The RT-PCR of FFPE sections and sequencing of RT-PCR products are useful for molecular epidemiology of the virus when viral isolation from fresh samples is unsuccessful.
Bacteriology
  • Akifumi OHTANI, Masahito KUBO, Hiroshi SHIMODA, Kenji OHYA, Tadashi IR ...
    2015 年 77 巻 7 号 p. 777-782
    発行日: 2015年
    公開日: 2015/08/01
    [早期公開] 公開日: 2015/02/27
    ジャーナル フリー
    Chlamydia pecorum (designated 22–58) was isolated in 2010 in HmLu-1 cells from the jejunum of a calf which died of necrotizing enterocolitis in Yamaguchi Prefecture, Japan. Immunohistochemical staining identified C. pecorum positive reactions in the jejunal villi. C. pecorum, designated 24–100, was isolated from the feces of a calf with diarrhea in another farm in Yamaguchi Prefecture in 2012. A significant increase in neutralizing antibody titers against C. pecorum was confirmed in paired sera. Nucleotide sequence identities of omp1 genes of the 2 isolates were 100%. The isolates were genetically and antigenically more closely related to C. pecorum Bo/Yokohama strain isolated from cattle with enteritis in Japan than to the other prototype strains, Bo/Maeda isolated from cattle with pneumonia and Ov/IPA isolated from sheep with polyarthritis. These results indicate that C. pecorum strains similar to 22–58 and 24–100 might be endemic in Yamaguchi Prefecture and cause enteric disease in cattle.
Clinical Pathology
  • Elvio E. RÍOS, Luciana A. CHOLICH, Gabriela CHILESKI, Enrique N. GARCÍ ...
    2015 年 77 巻 7 号 p. 847-850
    発行日: 2015年
    公開日: 2015/08/01
    [早期公開] 公開日: 2015/03/02
    ジャーナル フリー
    This study describes an occurrence of pink morning glory (Ipomoea carnea) intoxication in goats in northern Argentina. The clinical signs displayed by the affected animals were ataxia, lethargy, emaciation, hypertonia of the neck muscles, spastic paresis in the hind legs, abnormal postural reactions and death. The clinico-pathologic examination revealed that the affected animals were anemic and their serum level of aspartate aminotransferase was significantly increased. Cytoplasmic vacuolation in the Purkinje cells and pancreatic acinar cells was observed by histological examination. The neuronal lectin binding pattern showed a strong positive reaction to WGA (Triticum vulgaris), sWGA (succinylated T. vulgaris) and LCA (Lens culinaris). Although I. carnea is common in tropical regions, this is the first report of spontaneous poisoning in goats in Argentina.
Immunology
  • Viskam WIJEWARDANA, Kikuya SUGIURA, Daluthgamage Patsy H. WIJESEKERA, ...
    2015 年 77 巻 7 号 p. 771-775
    発行日: 2015年
    公開日: 2015/08/01
    [早期公開] 公開日: 2015/02/20
    ジャーナル フリー
    Previously, we reported that ovarian hormones affect the immune response against E. coli isolated from the dogs affected with pyometra. In order to investigate mechanisms underlying the immune modulation, we examined the effects of ovarian hormones on the generation of dendritic cells (DCs), the most potent antigen presenting cell. DCs were differentiated from peripheral blood monocytes (PBMOs) using a cytokine cocktail. Both estrogen receptor and progesterone receptors were expressed by the PBMOs and immature DCs. When various ovarian hormones were added to the culture for the DC differentiation, progesterone significantly decreased the expression of DC maturation markers, such as CD1a, CD80 and CD86, on mature DCs. Conversely, the addition of estrogen to the cultures increased the expression of CD86, but not other maturation makers. Furthermore, DCs differentiated in the presence of progesterone did not stimulate allogeneic mononuclear cells in PB. Taken together, these results indicate that progesterone diminishes the maturation of DCs, leading to decreased immune responses against invading pathogens.
Internal Medicine
  • Shuhei HIDAKA, Mitsutoshi KOBAYASHI, Kunihide ANDO, Yoshikazu FUJII
    2015 年 77 巻 7 号 p. 829-835
    発行日: 2015年
    公開日: 2015/08/01
    [早期公開] 公開日: 2015/03/15
    ジャーナル フリー
    Lomefloxacin is a broad-spectrum fluoroquinolone antibiotic used for the treatment of bacterial extraocular disease. This study investigated the efficacy and safety of lomefloxacin eye drops for bacterial extraocular disease in horses. Lomefloxacin ophthalmic solution (0.3%) was instilled three times daily for 2–5 days in 65 horses diagnosed with bacterial extraocular disease based on clinical findings. Clinical observations and bacteriological examinations were performed at the start of treatment, 2 and 5 days after the start of treatment, and at the discontinuation or termination of treatment. Of the 65 horses, 64 were positive for bacteria, and 22 bacterial genera and 47 bacterial species were identified. The efficacy of lomefloxacin was evaluated in 63 horses; one horse with a negative culture and another with suspected bacterial contamination were excluded. Lomefloxacin was considered to be clinically effective in 54 horses. The major bacterial species identified were Staphylococcus aureus, Streptococcus equi subsp. zooepidemicus, Acinetobacter lwoffii, Staphylococcus xylosus, Staphylococcus vitulinus, Enterobacter agglomerans, Flavimonas oryzihabitans and Staphylococcus sciuri, with a cumulative disappearance rate of 80% or more at the termination of instillation. Excluding one horse that did not undergo a bacteriological examination, the remaining 62 horses were assessed for bacteriological outcome. Full or partial bacterial clearance was detected in 95% or more of the 62 horses. One of the 65 horses reported adverse events that had no causal relation with the eye drops. Our results showed that lomefloxacin is safe and effective for the treatment of bacterial extraocular disease in horses.
  • Seishiro CHIKAZAWA, Yasutomo HORI, Fumio HOSHI, Kazutaka KANAI, Naoyuk ...
    2015 年 77 巻 7 号 p. 843-846
    発行日: 2015年
    公開日: 2015/08/01
    [早期公開] 公開日: 2015/02/19
    ジャーナル フリー
    In the present study, we examined the relationship between serum ferritin concentration before treatment and survival time in dogs with multicentric lymphoma. Eighteen dogs with multicentric lymphoma were enrolled in the study. When the dogs were classified into high and low ferritin groups on the basis of their serum ferritin concentration (3,000 ng/ml cut-off value), the median survival time of dogs with high concentrations (≥3,000 ng/ml, n=7) was 40 days, whereas it was 360 days among dogs with low concentrations (<3,000 ng/ml, n=11). This difference was statistically significant (P=0.001). This finding suggests that the initial high level of serum ferritin indicates short survival time in dogs with multicentric lymphoma. Large-scale research is necessary to confirm this finding.
  • Bhuminad DEVKOTA, Masahiro TAKAHASHI, Saori SATO, Kouya SASAKI, Atsush ...
    2015 年 77 巻 7 号 p. 875-878
    発行日: 2015年
    公開日: 2015/08/01
    [早期公開] 公開日: 2015/03/09
    ジャーナル フリー
    Blood samples were obtained sequentially from 10 dairy cows around the time of parturition to assess plasma fluctuations in estradiol-17β (E2) levels in association with those of several bone resorption markers. Plasma E2 concentration increased sharply a few days prepartum and decreased quickly after parturition. In terms of bone resorption markers, the plasma level of tartrate-resistant acid phosphatase isoform 5b (TRAP5b) rose significantly, commencing 1 week prepartum, and was maintained at this level to a few days postpartum. The plasma concentration of carboxyterminal collagen cross-links of type-I collagen (CTx) increased significantly after parturition. These observations suggest that osteoclast-mediated bone resorption was activated after parturition when plasma E2 concentrations decreased.
  • Shigeo OWAKI, Saiko KAWABUCHI, Kosuke IKEMITSU, Haruhi SHONO, Hidefumi ...
    2015 年 77 巻 7 号 p. 879-881
    発行日: 2015年
    公開日: 2015/08/01
    [早期公開] 公開日: 2015/03/14
    ジャーナル フリー
    Six adult dairy cows clinically diagnosed as hemorrhagic bowel syndrome (HBS) were the subjects of this study. The involved intestinal lesions were fixed in formalin and examined macroscopically and histopathologically. Pathological examinations revealed large intramural hematomas with necrotic foci, resulting in luminal obstruction. The mucosal layer in the lesions was detached from the intestinal wall, and there were no hemorrhagic changes in the lumen. The intramural hematomas were sometimes covered with histologically intact mucosal layer. These pathological findings were not consistent with those of “intraluminal blood clots” reported previously. Gram-positive and anti-Clostridium antibody-positive short bacilli were found in hemorrhagic necrotic areas. However, the exact relationship between Clostridium spp. observed in the lesions and HBS remains unclear, because this bacterium is a normal inhabitant in cattle.
  • Saori MIURA, Noriyuki HORIUCHI, Kotaro MATSUMOTO, Yoshiyasu KOBAYASHI, ...
    2015 年 77 巻 7 号 p. 883-887
    発行日: 2015年
    公開日: 2015/08/01
    [早期公開] 公開日: 2015/03/13
    ジャーナル フリー
    Monoclonal integration of bovine leukemia virus (BLV) proviral DNA into bovine genomes was detected in peripheral blood from two clinical cases of enzootic bovine leukosis (EBL) without enlargement of superficial lymph nodes. A BLV-specific probe hybridized with 1 to 3 EcoRI and HindIII fragments in these 2 atypical EBL cattle by Southern blotting and hybridization, as well as in 3 typical EBL cattle. The probe also hybridized to a large number of EcoRI and HindIII fragments in 5 cattle with persistent leukosis. These results suggest that the detection of monoclonal integration of BLV provirus into the host genome may serve as a marker of monoclonal proliferation and malignancy in difficult to diagnose EBL cattle.
Laboratory Animal Science
  • Jun-ichi SUTO
    2015 年 77 巻 7 号 p. 809-813
    発行日: 2015年
    公開日: 2015/08/01
    [早期公開] 公開日: 2015/03/05
    ジャーナル フリー
    Newborn offspring of the inbred mouse RR/Sgn strain have a low survival rate prior to weaning. We hypothesized that this is a consequence of an inferior nurturing ability of RR/Sgn mothers and that RR/Sgn mothers have a tendency to lose their pups. We performed quantitative trait locus (QTL) mapping for inferior nurturing ability and tendency to lose pups in RR/Sgn mothers. The number of pups was adjusted to 6 per dam on the day of delivery, and the number of surviving pups and their total weight (litter weight) were scored at 12 days after birth. Nurturing ability was evaluated by litter weight, and tendency to lose pups was evaluated by scoring whether or not the mothers lost their pups. For litter weight, we identified one significant QTL on chromosome 4 and three suggestive QTLs on chromosomes 7, 9 and 17. The RR/Sgn allele was associated with lower litter weight at all loci. For the tendency to lose pups, we identified three suggestive QTLs on chromosomes 4, 9 and 16. The RR/Sgn allele was associated with an increased tendency to lose pups at all loci. These results supported our hypothesis that the low survival rate phenotype was attributable, at least in part, to a phenotype whereby mothers display inferior nurturing ability and a tendency to lose pups. Thus, it suggests that these two traits share genetic basis.
Pathology
  • Akihiko SUGIYAMA, Jing SUN, Kota UEDA, Satoshi FURUKAWA, Takashi TAKEU ...
    2015 年 77 巻 7 号 p. 789-797
    発行日: 2015年
    公開日: 2015/08/01
    [早期公開] 公開日: 2015/03/05
    ジャーナル フリー
    Six-day-old rats were treated intraperitoneal injections with methotrexate 1 mg/kg, and the cerebellum was examined. Both the length and width of the vermis decreased in the methotrexate-treated group instead of the control from 4 day after treatment (DAT) onward. A significant reduction in the width of the external granular layer was detected on 2 and 3 DAT in the methotrexate group. By 4 DAT, the width of the external granular layer of the methotrexate group was indistinguishable from the control, and by 8 DAT, it was greater than that of the control. The molecular layer of methotrexate group on 8 and 15 DAT was thinner than that of the control. On 1 DAT, in the methotrexate group, there were many TUNEL and cleaved caspase-3-positive granular cells throughout the external granular layer, and they decreased time-dependently. On 1 DAT, in the methotrexate group, phospho-histone H3-positive cells in the external granular layer were fewer than in the control and tended to increase on 2–4 DAT. The p21-positive-rate of the external granule cells in the MTX group was higher than in the control on 1–4 DAT. These results suggested that methotrexate exposure on postnatal day 6 induces a delay, slowing in the migration of external granular cells to the inner granular layer, attributed to decrease or inhibition in the production of external granular cells that had arisen from apoptosis and the decrease in cell proliferative activity, resulting in cerebellar hypoplasia.
  • Mizuki KURAMOCHI, Takeshi IZAWA, Mayuka HORI, Kayo KUSUDA, Junichiro S ...
    2015 年 77 巻 7 号 p. 893-895
    発行日: 2015年
    公開日: 2015/08/01
    [早期公開] 公開日: 2015/03/13
    ジャーナル フリー
    A 19-year-old female Bengal tiger (Panthera tigris tigris) was presented with hind limb weakness, ataxia and respiratory distress. Computed tomography revealed a mass between the left side of the T7 vertebra and the base of the left 7th rib. The tiger then died, and necropsy was performed. Grossly, the vertebral mass was 6 × 5.7 × 3 cm, and invaded the adjacent vertebral bone and compressed the T7 spinal cord. Histologically, the mass was composed of large, clear, vacuolated and polygonal cells with osteochondral matrix. Cellular and nuclear atypia were moderate. The vacuolated cells stained positively for cytokeratin and vimentin and negatively for S-100. Based on these findings, the present case was diagnosed as a vertebral chordoma; the first report in a tiger.
Physiology
  • Rieko OKAME, Keiko NAKAHARA, Noboru MURAKAMI
    2015 年 77 巻 7 号 p. 815-821
    発行日: 2015年
    公開日: 2015/08/01
    [早期公開] 公開日: 2015/03/15
    ジャーナル フリー
    We measured the plasma levels of amino acids at various reproductive stages in female rats, including the estrous cycle, pregnancy and lactation, and compared the resulting amino acid profiles using two- or three-dimensional figures. These figures revealed that the amino acid profiles of pregnant and lactating dams differed considerably from those during the estrous cycle or in male rats. The plasma levels of individual amino acids were almost the same between proestrus, estrus, metestrus and diestrus, and their profiles did not differ significantly. However, the amino acid profiles changed during pregnancy and lactation in dams. The plasma Ser level decreased significantly in mid and late pregnancy, whereas Tyr, Gly and His decreased significantly in the late and end stages of pregnancy, and Trp and Lys significantly decreased and increased at the end of pregnancy, respectively. Much larger changes in amino acid profiles were observed during lactation, when the levels of many amino acids increased significantly, and none showed a significant decrease. Plasma Pro, Ser and Gly levels increased continuously from day 1 until day 15 of lactation, whereas Asn and Met increased significantly from days 1 and 5 respectively until the end of lactation. These results suggest that the profiles of plasma amino acids show characteristic changes according to reproductive stage and that it may be necessary to consider such differences when performing amino acid-based diagnosis.
Public Health
  • Mai YAMAMOTO, Takashige KASHIMOTO, Ping TONG, Jianbo XIAO, Michiko SUG ...
    2015 年 77 巻 7 号 p. 823-828
    発行日: 2015年
    公開日: 2015/08/01
    [早期公開] 公開日: 2015/03/09
    ジャーナル フリー
    Vibrio vulnificus is the causative agent of primary septicemia, wound infection and gastroenteritis in immunocompromised people. In this study, signature-tagged mutagenesis (STM) was applied to identify the virulence genes of V. vulnificus. Using STM, 6,480 mutants in total were constructed and divided into 81 sets (INPUT pools); each mutant in a set was assigned a different tag. Each INPUT pool was intraperitoneally injected into iron-overloaded mice, and in vivo surviving mutants were collected from blood samples from the heart (OUTPUT pools). From the genomic DNA of mixed INPUT or OUTPUT pools, digoxigenin-labeled DNA probes against the tagged region were prepared and used for dot hybridization. Thirty tentatively attenuated mutants, which were hybridized clearly with INPUT probes but barely with OUTPUT probes, were negatively selected. Lethal doses of 11 of the 30 mutants were reduced to more than 1/100; of these, the lethal doses of 2 were reduced to as low as 1/100,000. Transposon-inserted genes in the 11 attenuated mutants were those for IMP dehydrogenase, UDP-N-acetylglucosamine-2-epimerase, aspartokinase, phosphoribosylformylglycinamidine cyclo-ligase, malate Na (+) symporter and hypothetical protein. When mice were immunized with an attenuated mutant strain into which IMP dehydrogenase had been inserted with a transposon, they were protected against V. vulnificus infection. In this study, we demonstrated that the STM method can be used to search for the virulence genes of V. vulnificus.
  • Eriko MAEDA, Koichi MURAKAMI, Nobuyuki SERA, Kenitiro ITO, Shuji FUJIM ...
    2015 年 77 巻 7 号 p. 871-873
    発行日: 2015年
    公開日: 2015/08/01
    [早期公開] 公開日: 2015/03/08
    ジャーナル フリー
    Escherichia albertii occasionally causes food-borne outbreaks of gastroenteritis in humans; however, little is known about the vehicle of transmission. To screen retail chicken products for the presence of E. albertii, 104 retail chicken products were investigated. Portions of enrichment cultures that were PCR-positive for E. albertii (n=3) were sub-cultured on agar medium. Only 2 strains obtained from 2 chicken giblet samples were identified as E. albertii by multi locus sequence typing. Antimicrobial susceptibility testing showed that 1 strain was resistant to streptomycin and sulfisoxazole. Both strains harbored the virulence genes cdt and eae. This study is the first description of E. albertii isolation from retail food, suggesting that chicken products are a potential vehicle of E. albertii transmission.
Surgery
  • Tom ICHINOHE, Nobuo KANNO, Yasuji HARADA, Takuya YOGO, Masahiro TAGAWA ...
    2015 年 77 巻 7 号 p. 761-770
    発行日: 2015年
    公開日: 2015/08/01
    [早期公開] 公開日: 2015/02/17
    ジャーナル フリー
    Degenerative cranial cruciate ligament (CCL) rupture is characterized histologically by degenerating extracellular matrix (ECM) and chondroid metaplasia. Here, we describe the progression of chondroid metaplasia and the changes in the expression of ECM components in canine CCL rupture (CCLR). CCLs from 26 stifle joints with CCLR (CCLR group) and normal CCLs from 12 young beagles (control group) were examined histologically and immunohistochemically for expression of type I (COLI), type II (COLII), type III collagen (COLIII) and Sry-type HMG box 9 (SOX9). Cell density and morphology of CCLs were quantified using hematoxylin–eosin staining. The percentage of round cells was higher in the CCLR group than in controls. COLI-positive areas were seen extensively in the connecting fibers, but weakly represented in the cytoplasm of normal CCLs. In the CCLR group, there were fewer COLI-positive areas, but many COLI-positive cells. The percentages of COLII-, COLIII- and SOX9-positive cells were higher in the CCLR group than in controls. The number of spindle cells with perinuclear halo was high in the CCLR group, and most of these cells were SOX9-positive. Deposition of COLI, the main ECM component of ligaments, decreased with increased COLIII expression in degenerated CCL tissue, which shows that the deposition of the ECM is changed in CCLR. On the contrary, expression of SOX9 increased, which may contribute to the synthesis of cartilage matrix. The expression of COLII and SOX9 in ligamentocytes showed that these cells tend to differentiate into chondrocytes.
  • Juyeon OH, Sunghoon JEON, Jihye CHOI
    2015 年 77 巻 7 号 p. 783-788
    発行日: 2015年
    公開日: 2015/08/01
    [早期公開] 公開日: 2015/03/06
    ジャーナル フリー
    This study evaluated perfusion of skeletal muscle using contrast enhanced ultrasonography in humerus, radius, femur and tibia in normal dogs. Contrast enhanced ultrasonography for each region was performed after injecting 0.5 mL and 1 mL of contrast medium (SonoVue) in every dog. Blood perfusion was assessed quantitatively by measuring the peak intensity, time to the peak intensity and area under the curve from the time–intensity curve. Vascularization in skeletal muscle was qualitatively graded with a score of 0–3 according to the number of vascular signals. A parabolic shape of time–intensity curve was observed from muscles in normal dogs, and time to the peak intensity, the peak intensity and area under the curve of each muscle were not significantly different according to the appendicular regions examined and the dosage of contrast agent administered. This study reports that feasibility of contrast enhanced ultrasonography for assessment of the muscular perfusion in canine appendicular regions.
  • Toshie ISERI, Junichiro SHIMIZU, Hideo AKIYOSHI, Kayo KUSUDA, Akiyoshi ...
    2015 年 77 巻 7 号 p. 857-860
    発行日: 2015年
    公開日: 2015/08/01
    [早期公開] 公開日: 2015/03/03
    ジャーナル フリー
    A Bengal tiger was presented for evaluation of weakness, ataxia and inappetance. Computed tomography (CT) and magnetic resonance imaging (MRI) revealed a mass extending from the T7-8 vertebral body to the left rib and compressing the spinal cord. On CT, the bone destruction and sequestrum were shown. On MRI, the multilobulated mass appeared hypo- to isointense in T1-weighted and hyperintense in T2-weighted images. The tiger died after imaging, most likely from renal failure. Chordoma without metastasis was diagnosed on necropsy. The imaging characteristics were similar to those found in chordoma in humans. This report describes the use of CT and MRI in an exotic species.
  • Jun TAMURA, Takaharu ITAMI, Tomohito ISHIZUKA, Sho FUKUI, Kenjirou MIY ...
    2015 年 77 巻 7 号 p. 865-869
    発行日: 2015年
    公開日: 2015/08/01
    [早期公開] 公開日: 2015/03/05
    ジャーナル フリー
    To determine the reference level of central venous oxygen saturation (ScvO2) and clinical efficacy of central venous blood gas analysis, partial pressures of oxygen and carbon dioxide, pH, oxygen saturation, base excess (B.E.) and HCO3 concentration were compared between simultaneously obtained central venous and arterial blood samples from conscious healthy 6 dogs and 5 cats. Comparisons between arteriovenous samples were performed by a paired t-test and Bland-Altman analysis. Between arteriovenous samples, B.E. showed good agreement, but there were significant differences in other parameters in the dogs, and no good agreement was detected in cats. The ScvO2 in dogs and cats were 82.3 ± 3.5 and 62.4 ± 13.5%, respectively. Central venous blood gas analysis is indispensable, especially in cats.
  • Ai HORI, Kiwamu HANAZONO, Kenjirou MIYOSHI, Tetsuya NAKADE
    2015 年 77 巻 7 号 p. 889-892
    発行日: 2015年
    公開日: 2015/08/01
    [早期公開] 公開日: 2015/03/16
    ジャーナル フリー
    Porencephaly is the congenital cerebral defect and a rare malformation and described few MRI reports in veterinary medicine. MRI features of porencephaly are recognized the coexistence with the unilateral/bilateral hippocampal atrophy, caused by the seizure symptoms in human medicine. We studied 2 dogs and 1 cat with congenital porencephaly to characterize the clinical signs and MRI, and to discuss the associated MRI with hippocampal atrophy. The main clinical sign was the seizure symptoms, and all had hippocampal atrophy at the lesion side or the larger defect side. There is association between hippocampal atrophy or the cyst volume and the severe of clinical signs, and it is suggested that porencephaly coexists with hippocampal atrophy as well as humans in this study.
Virology
Wildlife Science
  • Tsukasa OKANO, Manabu ONUMA, Hiroko ISHINIWA, Noriko AZUMA, Masanori T ...
    2015 年 77 巻 7 号 p. 799-807
    発行日: 2015年
    公開日: 2015/08/01
    [早期公開] 公開日: 2015/03/08
    ジャーナル フリー
    The large Japanese field mouse, Apodemus speciosus, is a potential indicator of environmental stress, but this function has not been confirmed by histological studies. Since environmental stress affects the reproductive function of mice, we determined the reproductive characteristics of this species at two locations: Toyama (36°35ʹN, 137°24ʹE) and Aomori (40°35ʹN, 140°57ʹE). Mice were captured during May–November (n=119) and July–November (n=146) at these locations, respectively. We classified the breeding season from the numbers of pregnant females and young, in addition to the spermatogenic cycle and seasonal changes in seminiferous tubule morphology of males. Testicular weight was measured, and seminiferous tubule morphology was examined histologically. Fourteen stages were found in the seminiferous epithelium cycle based on acrosome formation and spermatid head morphology. At both locations, the breeding season peaked from late summer to early autumn and possibly in spring. Spermatogenic activity was classified into 4 periods from June to November: resting around June and October–November; resumptive around July; active around August; and degenerative around September. During the resting period, the seminiferous tubules consisted of Sertoli cells, spermatogonia and spermatocytes. Spermatogenesis began during the resumptive period, and spermatids were observed. During the active period, active spermatogenesis and a broad lumen were observed. During the degenerative period, spermatogenesis ended, and Sertoli cells, spermatogonia, spermatocytes and degenerating exfoliated round spermatids were observed. This study provides scientific information about the testicular histopathological evaluations of the large Japanese field mouse for its use as an index species of environmental pollution.
ERRATUM
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