Background: Postsurgical adhesions can occur following virtually all types of surgery, resulting in serious clinical complications. Therefore, prevention of adhesions is an important goal of surgical practice. A rat uterine horn model was used to investigate the efficacy of N,O-carboxymethylchitosan (NOCC) and spermine NONOate (SPER/NO) alone and in combination in preventing adhesion formation. Methods: Sixty Wistar albino rats underwent bilateral uterine horn injury with a unipolar cautery. Study groups were as follows: (i) control group, no adjuvant therapy; and those with adjuvant applied, (ii) normal saline group, 2 ml of normal saline was given; (iii) NOCC group, 2 ml of 2% NOCC gel was given; (iv) SPER/NO group, 2 ml of SPER/NO (0.5 mg/ml) was given, and (v) NOCC plus SPER/NO group, 2 ml of 2% NOCC gel including SPER/NO (0.5 mg/ml) was given. After 14 days, all animals were euthanatized, and a standard adhesion scoring system including extent and severity scores was applied by a blinded examiner. Results: The extent score in NOCC plus SPER/NO group was significantly lower than those of control and normal saline groups (p<0.05). The extent score in NOCC group was significantly lower than that of normal saline group (p<0.05). The extent score in NOCC plus SPER/NO group was significantly lower than that of SPER/NO group (p<0.05). The severity score was significantly lower in NOCC plus SPER/NO and NOCC groups than that of control group (p<0.05). The severity score was significantly lower in NOCC plus SPER/NO group than that of SPER/NO group (p<0.05). Conclusions: Postoperative administration of NOCC gel and SPER/NO alone and especially in combination to the site of peritoneal injury reduces the formation of adhesions in the rat uterine horn model.

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Mice carrying a mutation in the first intron of Unc5h3 were accidentally produced by transgenic insertion and characterized for their homozygous mutant phenotypes. Morphological and histological analysis revealed cerebellar and midbrain abnormalities, which are similar to the previously reported phenotypes of the Unc5h3 mutant. Behavioral analysis showed higher ambulatory activity and circling, and defects in habituation in a novel environment. Their body weights were 10-30% less than wildtype mice from 2-3 weeks of age to 22 months possibly due to reduced accumulation of adipose tissues. The transgenic insertion site was identified and mapped to the intron 1 of Unc5h3 gene with approximately 50 kb deletion of the intron sequence. This intronic mutation interfered with the mRNA expression of the Unc5h3 gene not in testes, but in many tissues including the brain, implying that this intronic region may play a role in regulating tissue-specific transcription of Unc5h3.

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The present study aimed to evaluate the development of pulmonary hypertension by serial echocardiography, including measurements of pulmonary artery (PA) flow velocities, and correlate echocardiographic indices with pathological findings in rats administered monocrotaline (MCT). MCT (60 mg/kg body weight) or physiologic saline was administered to a total of 9 male Wistar rats at the age of 4 weeks (MCT group: n=4, control group: n=5, respectively). Echocardiography was performed serially until the age of 8 weeks. The ratio of right ventricular (RV) outflow tract dimensions to aortic dimensions increased progressively in the MCT group and became significantly greater than that of the control group after the age of 6 weeks. Peak PA velocity (Peak V) in the MCT group was significantly less than that of the control group at the ages of 7 and 8 weeks. The ratio of acceleration time to ejection time (AT/ET) in PA flow waveforms declined progressively and was significantly less than that of the control group after the age of 6 weeks. The ratio of RV weight to body weight (RVW/BW) in the MCT group was significantly greater than that of the control group. Both AT/ET ratio and Peak V were significantly inversely correlated with RVW/BW ratio. Furthermore, these echocardiographic findings were also significantly inversely correlated with the mean cross-sectional RV myocyte area. In conclusion, the progressive development of pulmonary hypertension leading to RV hypertrophy can be evaluated appropriately by echocardiography including PA flow Doppler indices in rats.

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The Komeda diabetes-prone (KDP) rat is a spontaneous animal model of human autoimmune type 1 diabetes. By positional cloning of the non-MHC major susceptibility locus Iddm/kdp1, we recently identified a nonsense mutation in Cblb and also found that lymphocytes of KDP rats infiltrate into various tissues, indicating autoimmunity. The maintenance and production of KDP rats has been a critical problem owing to the poor reproductive ability of diabetic animals. To solve the problem, we here established the KDP rat as a segregating inbred strain. We first identified animals that were heterozygous at the Iddm/kdp1 region in a breeding colony of KDP rats. The heterozygous region spans at least from D11Yok1 to Cblb on rat chromosome 11. By mating between the heterozygous rats, we obtained homozygotes, heterozygotes and wild-types with the expected ratio of 1 : 2 : 1 and found that only the homozygotes developed diabetes, suggesting that these genotypes represent those of Iddm/kdp1. We then tried to maintain KDP rats by mating between the heterozygotes, which resulted in a segregating inbred strain. Within 210 d of age, about 80% of Iddm/kdp1 homozygotes developed diabetes with severe insulitis, while neither heterozygotes nor wild-types developed diabetes. The phenotypic characteristics of the homozygotes are the same as those of progeny of diabetic parents in the original KDP rats. The segregating inbred KDP rat strain described here would serve as a useful animal model for autoimmune diseases, including type 1 diabetes.

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A genomic region between D1Wox8 and D1Rat90 on rat chromosome 1 was previously shown to be linked to intramuscular fat accumulation by quantitative trait locus (QTL) analysis using a F₂ population derived from the Otsuka Long-Evans Tokushima Fatty (OLETF) rat, which exhibits an increase in the levels of intramuscular fat content in Musculus longissimus, and the F344 rat. There exist two regions showing major and minor lod peaks for linkage to intramuscular fat accumulation, in the chromosomal region. We constructed a congenic strain introgressing the OLETF allele on the minor but not the major lod peak region in the F344 rat strain. The congenic strain had higher levels of intramuscular fat content in Musculus longissimus than the inbred partner F344 rat, thereby proving the existence of a QTL, designated Imfm (for Intramuscular fat-minor), responsible for the intramuscular fat accumulation in the congenic region of the minor lod peak region of about 10 cM. The F344.OLETF-Imfm congenic strain might provide a refined tool for the analysis of the gene causing intramuscular fat accumulation.

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Mature TCR αβ T cells in peripheral blood are generally classified into either CD4 single positive (sp) T cells or CD8sp T cells. Several studies demonstrated that considerable amounts of CD4⁺CD8⁺ double positive (DP) T cells exist in peripheral blood of human and several animals. In particular, we previously reported that peripheral DP T cells increase in an age-related manner in cynomolgus monkeys (Macaca fascicularis), but the finding that DP T cells in some aged monkeys were maintained at a low proportion (under 5%), suggests that the increase in peripheral DP T cells might be genetically controlled in cynomolgus monkeys. To test this hypothesis, 24 families were randomly selected and used in a formal genetic analysis of the proportion of DP T cells. Parents and offspring in selected families were classified into DP-High and DP-Low groups based on a 5% cutoff level of DP T cells. The cutoff value was set by analysis of the distribution of the proportion of DP T cells. Nine out of 13 offspring (69.2%) with DP-High × DP-High parents belonged to the DP-High group, whereas three out of nine offspring (33.3%) belonged to DP-High group in the case of DP-High × DP-Low mating pairs. No offspring (0%) of two offspring with DP-Low × DP-Low parents belonged to the DP-High group. In addition, heritability (h²: narrow sense) obtained from the regression coefficient of offspring on mid-parent values was 0.54 ± 0.19. Both findings suggest that increases in DP T cells in cynomolgus monkeys may be genetically controlled.

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To clarify whether oxidative stress is involved in the pathogenesis of islet lesions of diabetic animals, the effects of probucol (PB), an antioxidant and anti-hyperlipidemia agent, on the islets in streptozotocin (SZ)-induced diabetic APA hamsters in the acute and chronic phases of diabetes were examined. The control (CB group) and diabetic (SZ group) hamsters were treated with PB (1% in the diet) for 4 weeks from several days after SZ injection as the acute diabetic group, or 8 weeks from 6 weeks after SZ injection as the chronic diabetic group. Glucose tolerance test revealed that PB treatment decreased the high serum glucose level after glucose injection in the diabetic APA hamsters in the acute diabetic phase. Immunohistochemistry revealed that PB treatment significantly increased the percentage of the insulin positive area in the diabetic hamsters pancreata in both the acute and chronic phases. In addition, 4-hydroxy-2-nonenal (4HNE; an oxidative stress marker) positive cells were slightly reduced by PB treatment in the acute diabetic phase. Double-immunostaining for insulin and PCNA (proliferating cell nuclear antigen) revealed that elevation of the percentage of insulin and PCNA double-positive cells against insulin-positive cells was seen in the islets of PB-treated diabetic hamsters, but the difference was not significant compared with untreated diabetic hamsters (p=0.07). In semi-quantitative RT-PCR, the expression of two genes, Reg (Regenerating gene) and INGAP (islet neogenesis associated protein), in the diabetic APA hamsters was significantly increased compared to the control groups in both diabetic phases. PB treatment significantly reduced Reg expression in the chronic diabetic phase. These data suggest that PB treatment in SZ-injected diabetic hamsters partially restored β-cell function through acting as an antioxidant and induced higher expression of Reg and INGAP genes in the pancreas of hamsters.

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Reproductive features of newly bred Russian voles (Microtus rossiaemeridionalis) as a laboratory animal were studied. This species is a copulatory ovulator, and most couples copulated 6 to 16 h after pairing. The gestation period varied from 18 to 22 days (mean ± SD: 20.6 ± 0.9, n=72), and the average litter size was 4.6 ± 1.9 (n=125). Compared with the litter size at the first parturition (3.6 ± 1.6, n=72), the litter size in the subsequent parturitions increased to 5.9 ± 1.4 (n=53). The animals exhibited postpartum estrus, and repeated pregnancy accompanied with suckling pups and parturition continuously in the laboratory condition unlike other vole species. In view of their complex stomach and good proliferation, the Russian voles were evaluated as a good laboratory animal, especially as a model animal for ruminant studies.

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Acute myocardial ischemia was induced by occluding the LAD in Clawn miniature pigs. Eight pigs (group 1) were subjected to 6 h ischemia and nine pigs (group 2) were subjected to 20 min ischemia, followed by reperfusion for 340 min. Three animals of the group 1 died due to ventricular fibrillation after occlusion and in group 2, four animals died due to the arrhythmia after reperfusion. Though the ischemic area of group 2 (15.6% of the ventricle) was narrower than that of group 1 (21.7%), the survival rate was lower. We supposed that ischemia-reperfusion injuries were strongly connected with the hemodynamics of group 2. Clawn miniature pigs are useful experimental animals for myocardial ischemic researches.

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A spontaneous T-cell-rich B-cell lymphoma (TCRBCL) occurred as a subcutaneous mass in the buccal region and enlarged submandibular lymph node in a 6-year-old female cynomolgus monkey (Macaca fascicularis). The constituent cells were examined by histology, immunohistochemistry and the double labeled-immunofluorescence method (dl-IF). Further, in situ hybridization (ISH) was employed to detect the gene expression of Epstein Barr virus (EBV). Histologically, the mass was comprised mainly of neoplastic large lymphoid cells and reactive small mononuclear cells. Immunohistochemically, the neoplastic large lymphoid cells were positive for CD20, CD79α, MHC class II, and either IgG, IgM, or IgA. Polyclonal Ig production by the neoplastic large lymphoid cells was demonstrated by dl-IF, although IgG-positive ones predominanted in number. On the other hand, most of the small mononuclear cells were positive for CD3 and were regarded as reactive T lymphocytes, while the remaining cells appeared to be histocytes or reactive B-cells. Transcripts of EBV gene were not demonstrated in these neoplastic or reactive cells by ISH. This is the first reported case of spontaneous TCRBCL in the cynomolgus monkey.

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A simple tubing stent was attempted to test a model for sutureless gastrointestinal anastomosis in 6 male rats at the age of 15 weeks. In the 3rd and 4th weeks after the operation, X-ray examination demonstrated that the gastrointestinal passage in the anastomotic site was quite satisfactory. There was no incidence of anastomotic leakage. In the 6th week after the operation, there were no macroscopic or microscopic ruptures, nor were there any obstructions at the anastomotic site. This simple sutureless method was effective at preparing anastomosis in the gastrointestinal tract in the rat and could be applied to other small experimental animals.

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We have established a new method of anesthesia with nasopharyngeal insufflation for intraoral procedure in rodents. Twelve male Wistar rats weighing 330-390 g were used in this study. Insertion of a feeding tube 1.0 mm in diameter coated with 2% xylocaine jelly was inserted into the nasal cavity approximately 25 mm from the naris, and anesthetization with mixed gas of 100% oxygen with 3-4% enflurane at 0.25-0.5 l/min flow rate was achieved. Using this anesthetic method, a chronic experiment comprising 1-h/day experimental procedure was carried out for 14 days. This method enabled, 1) simple and safe operation of the induction, emergence and anesthetic depth, 2) experimental procedures on the dental/oral region, 3) avoidance of the dyspnea and tachypnea, and 4) avoidance of cumulative effects in daily anesthesia.

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Amounts of DNA strand breaks were estimated by the proportion of cells without tails (PCWT) and the average lengths of tail momentum (ALTM) in comet images of tissue cells of senescence-accelerated prone (SAMP1) mouse and senescence-accelerated resistant (SAMR1) mouse. The PCWT and ALTM of brain cells from SAMR1 were unchanged from 4 to 15 months of age. In the case of SAMP1 brain cells, the PCWT decreased and the ALTM increased in an age-related manner from 8 to 15 months of age. In the cases of liver and kidney, the PCWT and the ALTM of both SAMP1 and SAMR1 cells showed constant values from 4 to 15 months of ages.

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The aim of this study was to examine both the validity and application of noninvasive measurement of blood pressure (BP) at the brachial artery in hamsters. There were significant correlations between noninvasive and invasive values for systolic BP (SBP), mean BP, and diastolic BP (r=0.96, r=0.93, r=0.88, respectively, all p<0.0001). Furthermore, SBP appeared to be the most accurate noninvasive BP index because both proportional and constant systematic errors were the least among the three indices. Peripheral vascular resistance calculated by combination with echocardiographic indices actually reflected the prominent a1-adrenergic drive induced by b-adrenergic blockers. In conclusion, noninvasive BP measurement at the brachial artery can provide useful information regarding the integrated cardiovascular function in hamsters.

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Protein gene product 9.5 (PGP9.5) is expressed at high level in the neural and neuroendocrine systems. We investigated the localization and degree of expression of PGP9.5 in the developing mouse placenta and embryo at 6.5, 10.5 and 14 days of gestation using an immunohistochemical technique. At 6.5 days of gestation PGP9.5 was detected at various levels in decidual and primary trophoblast giant cells in the placenta, and in embryonic ectodermal cells in the embryo. At 10.5 and 14 days of gestation PGP9.5 was expressed at moderate to strong levels in neurons in the embryo, but rarely in the placenta. These findings suggest that the protein may play a significant role in implantation and placental development, and differentiation of embryonic ectoderm.

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