Explore the vast range of titles available.

Previously, we found that a greater dissimilarity in swine leukocyte antigen (SLA) class I and class II alleles between mating partners resulted in increased farrowing rates in a highly inbred population of Microminipigs (MMPs). In this follow-up study, we have analyzed the effects of dissimilarity in SLA alleles between mating partners for seven different reproductive traits, including litter size and the number of stillborn and live or dead weaned piglets. We determined the relationships among reproductive traits within each mating event and the amino acid distances of SLA alleles as markers of diversity between mating partners. Our results indicate that mating partners with greater amino acid pairwise genetic distances in the SLA-1 class I gene or DQB1 class II gene alleles were associated with significantly larger litter sizes and higher numbers of live piglets at birth and weaning. Also, partners with greater pairwise distances in the SLA-2 class I gene alleles exhibited fewer pre-weaning deaths. These findings suggest that the dissimilarity in SLA class I and class II alleles between mating partners may affect not only farrowing rates but also other key reproductive traits such as litter size and improved piglet survival rates. Consequently, SLA alleles could serve as valuable genetic markers for selecting mating partners in breeding programs and for conducting epistatic studies on various reproductive traits in MMPs.

We have previously reported specific swine leukocyte antigen (SLA) haplotype associations with significant effects on several reproduction performance traits in a highly inbred miniature pig population of Microminipigs (MMPs). In this study, to clarify the effects on farrowing rates of SLA similarity between mating partners in the MMP population, we compared the farrowing rates as a measure of reproductive success after 1063-cumulative matings among the following three groups of mating partners: (1) completely sharing SLA class I or class II haplotypes or alleles between partners (CS), (2) only one sharing the haplotypes or alleles (OS), and (3) non-sharing the haplotypes or alleles (NS). Average farrowing rates in CS groups consisting of completely sharing SLA class II haplotypes or DRBI and DQB1 alleles were lowest in the three groups. Moreover, lower farrowing rates were indicated in mating pairs with smaller amino acid pairwise genetic distances of SLA-1, SLA-3, DRB1 and DQB1 alleles between the pairs. These results suggested that the dissimilarity of SLA class I and class II alleles between mating partners markedly improved reproductive performance; therefore, SLA alleles or haplotypes are potentially useful genetic markers for the selection of mating pairs in breeding programs and epistatic studies of reproductive traits of MMPs.

As the pathophysiology of Microminipigs (μMPs) is similar to that of human, μMPs are useful in atherosclerosis research. To clarify the effect of methotrexate (MTX) on atherosclerosis, we investigated the pathology of MTX-induced atherosclerosis lesion exacerbation in μMPs fed a high-fat and high-cholesterol diet (HFHCD). The μMPs were divided into four groups: HFHCD, HFHCD+MTX, HFHCD+MTX+leucovorin (LV), and HFHCD+MTX+folic acid (FA), and fed for two weeks. Laboratory tests including blood lipid, FA, and homocysteine (Hcy) levels, and pathological evaluation of the atherosclerosis lesion area and thickness were performed. Hepatic and jejunal gene expressions related to lipid and folate metabolism pathways including 5-methyltetrahydrofolate-homocysteine methyltransferase (MTR) were monitored using RT-PCR. The HFHCD+MTX group showed increased blood Hcy ( <0.01) and decreased FA levels ( <0.05) in accordance with increased hepatic MTR mRNA expression ( <0.1) and exacerbation of atherosclerosis ( =0.051 for lesion area and =0.045 for lesion thickness) compared to the HFHCD group. Administration of LV or FA attenuated the MTX-induced increase in the Hcy level ( <0.01), atherosclerosis lesion thickness ( <0.1), and MTR mRNA expression ( <0.1 in HFHCD+MTX HFHCD+MTX+LV groups). MTX exacerbated HFHCD-induced atherosclerosis mediated through reduced blood FA and the subsequent increase of Hcy in μMPs, indicating that the μMP model may advance cardio-oncology research by providing useful experimental approaches. As MTX is administered for rheumatoid arthritis and malignant tumors in humans, atherosclerosis exacerbation should be acknowledged as a possible adverse effect of MTX treatment.

Background/Aim: The reproducibility of athero – sclerotic lesions was evaluated after the production of cloned-microminipigs and their offspring. Materials and Methods: Cloned-microminipig-parents were produced by microminipigsomatic cell nuclei. These parents were crossbred and delivered males (F1-offspring) were divided into two groups: normal chow diet (NcD)-fed and high-fat/high-cholesterol diet (HcD)-fed groups. One of the F1-offsprings was subjected to cloning, and delivered males (F1-clones) were fed with HcD. After 8 weeks, all animals were necropsied for patho – physiological studies compared to non-cloned-microminipigs. Results: HcD-fed F1-offspring and F1-clones, but not NcD-fed F1-offspring, exhibited increased serum lipid levels and systemic atherosclerosis, which were comparable to those of HcD-fed non-cloned-microminipigs. Homogeneity of variance analysis demonstrated that standard deviation values of serum lipoprotein and aortic atherosclerosis area from HcD-fed animals decreased in F1-offspring and F1-clones. Conclusion: HcD-induced atherogenesis was highly reproducible in F1-offsprings and F1-clones, indicating that the atherosclerosis-prone genomic background was preserved in the cloned-microminipigs, which can be used for studies on human atherosclerosis and related diseases.

The microminipig is a relatively new type of mini pig; microminipigs weigh about 10 kg at 6 months of age and are expected to be of use in drug discovery research and safety tests. Herein, we analyzed the characteristics of ejaculated sperm from microminipigs. Sperm parameters such as microstructure and sensitivity to cold shock were investigated using optical or scanning electron microscopy. Ejaculate volumes and total numbers of sperm were lower than in standard pig strains, but were proportional to body weight. Ejaculation time, pH of the ejaculate, sperm motility and morphology, and sensitivity to cold shock were similar to those of standard pig strains. Herein, we provide the first characterization of the ejaculates of microminipigs and demonstrate that this type of pig will be useful not only in medical research, but also in investigations into sperm preservation in different pig breeds.

An appropriate animal model is essential to investigate the relationship between inflammation, atherosclerosis, and thrombogenesis, and the development of preventive measures and therapies for atherosclerosis. Atherosclerosis was induced in Microminipigs (MMPs) using a high-fat diet. We assessed high mobility group box 1 (HMGB1) expression levels and measured thrombus formation using a Total Thrombus Formation Analysis System (T-TAS). MMPs were divided into a normal diet (control) group and four high-fat diet groups, with differing amounts of cholesterol. After 8 weeks, blood was collected for analysis. HMGB1 levels increased with increasing dietary cholesterol, and a negative correlation was found between HMGB1 levels and thrombus formation time. T-TAS is useful in the assessment of thrombogenesis in MMPs and HMGB1 is associated with thrombus formation.

PurposeTo define the radiological arterial anatomy in mature microminipigs as a pre-clinical research animal model in interventional radiology.Materials and MethodsFive female microminipigs (weighing 20.9 ± 2.9 kg) were used in this study. Under general anesthesia, computed tomography (CT) angiography was performed using a 16-slice CT scanner. CT was performed 12 s after initiation of an intravenous injection of 40 ml of nonionic contrast media at 3.0 ml/second using a power injector. The transverse CT angiography images were evaluated using a digital imaging and communication in medicine viewer, and the diameters of the following 41 arteries were measured.: ascending aorta, descending aorta, thoracoabdominal aorta, abdominal aorta, pulmonary artery trunk, both pulmonary, brachiocephalic artery, short common bicarotid, both common carotid artery, subclavian, bronchial, internal mammary, celiac, common hepatic, left lateral hepatic, middle hepatic, left hepatic, gastroduodenal, cranial duodenopancreatic, splenic, left gastric, cranial mesenteric, ileocolic , bilateral colic artery, caudal mesenteric, cranial rectal, renal, both external iliac arteries, internal iliac common trunk, and both internal iliac and femoral arteries.ResultsThe microminipigs’ vascular anatomy was the same as domestic pig anatomy and similar to human anatomy. The diameter of the aorta (ascending to abdominal) was 17.1–7.0 mm, iliac and femoral arteries (internal iliac common trunk to femoral artery): 5.5–3.8 mm, pulmonary arteries: 9.3–14.7 mm, and major first aortic branches (e.g., celiac or brachiocephalic artery): 2.2–9.2 mm.ConclusionThis study defined the microminipig arterial anatomy in the trunk.

Objective: Microminipig (MMP) is a miniature pig with an extra small body size for experimental use. In the present study, the occurrence of stillbirths and their genetic association with swine leukocyte antigen (SLA) class II haplotypes were evaluated in a population of MMPs.Methods: The occurrences of stillbirth and genetic association with SLA class II haplotypes using 483 stillborn and 2,246 live piglets, and their parents were compared among the three groups of newborn piglet litters; an all stillborn (AS) group consisting of only stillborn piglet litters, a partial stillborn (PS) group consisting of stillborn and live piglet litters, and an all alive (AA) group consisting of only live piglet litters.Results: The incidence of stillborn piglets was 483/2,729 (17.7%). Distributions of litter sizes, numbers of stillborn piglets in a litter, parities, and gestation periods were distinct among the three groups. The frequencies of low resolution haplotype (Lr)-0.7 or Lr-0.23 were higher in the AS group than in the PS or AA groups. In sires, the frequency of Lr-0.7 associated with the AS group was significantly higher in the AS group than with the AA group. In dams, the frequency of Lr-0.23 was significantly higher in the AS group than in the PS or AA groups, whereas the frequency of Lr-0.7 was not significantly different.Conclusion: The incidence of stillborn piglets in MMPs appears to be higher than those in other pig breeds. Several traits related with stillbirths such as the number of stillborn piglets and parities of the AS group were different from those of the PS and AA groups. Specific SLA class II haplotypes were associated significantly with a high incidence of stillbirths and could be used as genetic markers to adopt breeding strategies to lower the rate of stillbirth in MMPs.

Fluvoxamine is a selective serotonin-reuptake inhibitor, of which IC50 values for serotonin- and noradrenaline-uptake process were reported to be 3.8 and 620 nmol/L, respectively, also known to directly inhibit cardiac Na+, Ca2+, and K+ channels. We characterized microminipig as a laboratory animal by analyzing fluvoxamine-induced cardiovascular and dermatological responses under halothane anesthesia. Fluvoxamine maleate was infused in doses of 0.1, 1, and 10 mg/kg over 10 min with a pause of 20 min (n = 4). The peak plasma concentrations were 35, 320, and 1906 ng/mL, of which free plasma concentrations were estimated as 20, 187, and 1108 nmol/L, respectively. The low and middle doses did not alter any cardiovascular variable. The high dose increased heart rate and mean blood pressure, prolonged QRS width, but shortened QT interval, whereas no significant change was detected in PR interval or QTcF. Moreover, it induced systemic erythema on the skin. Pretreatment of H1/5-HT2A antagonist cyproheptadine hydrochloride sesquihydrate in a dose of 0.3 mg/kg significantly attenuated the fluvoxamine-induced pressor response; but tended to further enhance sinus automaticity, atrioventricular nodal conduction; and ventricular repolarization in addition to intraventricular conduction delay; whereas it markedly suppressed onset of systemic erythema (n = 4). In microminipigs, cardiovascular adverse effects of the high dose may be manifested as a sum of its inhibitory action on the cardiac ionic channels and its stimulatory effects on serotonergic and adrenergic systems, whereas dermatologic reaction can be induced primarily through H1/5-HT2A receptor-dependent mechanism. Thus, microminipigs may be used for analyzing such multifarious adverse events of clinical serotonergic pharmacotherapy.