Development of a Microminipig Model of Atherosclerosis for the Evaluation of a HMGCR Inhibitor

BACKGROUND/AIM

Atherosclerosis is known as a major risk factor for cardiovascular disease, and development of an animal model of atherosclerosis is required to investigate its clinical pathogenesis. We studied the optimal amount of cholesterol in the diet and the optimal experimental period for development of a Microminipig model of atherosclerosis for the evaluation of a hydroxymethylglutaryl-CoA reductase (HMGCR) inhibitor (atorvastatin).

MATERIALS AND METHODS

Eighteen male animals (3-4 months old) were divided into 3 groups. Group 1 consisted of control animals receiving a normal chow diet, Group 2 animals received a high fat (12% w/w) and low cholesterol (0.1% w/w) diet (HFLCD), and Group 3 animals received HFLCD+statin for 12 weeks. Animals received statin at 3 mg/kg body weight per day. HFLCD did not down-regulate the hepatic expression of HMGCR mRNA.

RESULTS

HFLCD increased body, omentum, and mesenteric adipose tissue weight, and induced hypercholesterolemia and atherosclerotic lesions in the abdominal aorta. HFLCD+statin inhibited hypercholesterolemia and atherosclerotic lesions, but not obesity.

CONCLUSION

A microminipig atherosclerosis model induced by HFLCD can be used in the evaluation of HMGCR inhibitors for the treatment of hypercholesterolemia and atherosclerosis.

Reduction in disialyl-T antigen levels in mice deficient for both St6galnac3 and St6galnac4 results in blood filling of lymph nodes

Sialic acid (SA) is present at the terminal ends of carbohydrate chains in glycoproteins and glycolipids and is involved in various biological phenomena. The biological function of the disialyl-T (SAα2-3Galβ1-3(SAα2-6)GalNAcα1-O-Ser/Thr) structure is largely unknown. To elucidate the role of disialyl-T structure and determine the key enzyme from the N-acetylgalactosaminide α2,6-sialyltransferase (St6galnac) family involved in its in vivo synthesis, we generated St6galnac3- and St6galnac4-deficient mice. Both single-knockout mice developed normally without any prominent phenotypic abnormalities. However, the St6galnac3::St6galnact4 double knockout (DKO) mice showed spontaneous hemorrhage of the lymph nodes (LN). To identify the cause of bleeding in the LN, we examined podoplanin, which modifies the disialyl-T structures. The protein expression of podoplanin in the LN of DKO mice was similar to that in wild-type mice. However, the reactivity of MALII lectin, which recognizes disialyl-T, in podoplanin immunoprecipitated from DKO LN was completely abolished. Moreover, the expression of vascular endothelial cadherin was reduced on the cell surface of high endothelial venule (HEV) in the LN, suggesting that hemorrhage was caused by the structural disruption of HEV. These results suggest that podoplanin possesses disialyl-T structure in mice LN and that both St6galnac3 and St6galnac4 are required for disialyl-T synthesis.

[A Case of Gastric Cancer Invading the Pancreas with Pathological Complete Response Treated by Preoperative S-1 plus Oxaliplatin Therapy]

A 66-year-old man with severe anemia was diagnosed with gastric cancer. CT examination revealed primary gastric tumor, which involved the pancreas body, with regional lymph nodes that were enlarged(T4b[panc], cN2, cM0, cStage ⅣA). He received three courses of preoperative S-1 plus oxaliplatin therapy. Primary tumor and metastatic lymph nodes were reduced remarkably. We performed a curative distal gastrectomy(D2)without pancreas resection. Histopathological examination revealed Grade 3 pathological complete response in both primary tumor and metastatic lymph nodes.

Ability of ergonomic timeout to reduce musculoskeletal discomfort related to fluoroscopic endoscopy

Endoscopists performing fluoroscopy procedures often suffer from musculoskeletal disorders (MSDs) due to persistent static muscle contraction and the load imposed by radiation personal protective equipment. We devised the "practical load-on-the-shoulders releasing technique" (PoRT), integrated it within the work-rest schedule, and investigated its ability to reduce muscular discomfort. The results showed that PoRT lowered discomfort, including by maintaining the head angle closer to the neutral position and keeping the trunk in a stable state, which together resulted in an ideal posture. As a simple, no-cost intervention based on an ergonomic approach, PoRT may contribute to reducing MSDs.

Data on long-term survival of the NOD/Shi-scid IL-2Rγnull (NOG) mouse in two facilities

The objective of this study was to investigate an appropriate observation period for an evaluation of tumorigenicity in NOD/Shi-scid IL-2 Rγ^null (NOG) mice. At SNBL, 19 male and 19 female NOG mice were observed the general condition from 7 weeks old up to 68 weeks old and at FBRI, 7 male and 16 female NOG mice were observed the general condition throughout the lifespan from 7 weeks old. The survival rate started to decline rapidly around 54 to 56 weeks of age in both facilities without a facility difference. Based on these survival data, it seems reasonable to terminate a tumorigenicity study at 52 weeks of age.

Cryptic species in a Vulnerable seabird: shorttailed albatross consists of two species

The occurrence of cryptic species within a threatened taxon is rare, but where they do occur, understanding species boundaries is essential for planning an effective conservation strategy. The short-tailed albatross Phoebastria albatrus is a Vulnerable seabird that mainly breeds on Torishima and the Senkaku Islands in the western North Pacific. Although it has been tacitly regarded as a single management unit with 2 breeding sites, the species is known to comprise 2 genetically separated populations (Senkaku-type and Torishima-type). However, morphological examination of birds from both populations has not been conducted owing to the difficulty in accessing the Senkaku Islands. In this study, we examined the morphological differences between immigrants from the Senkaku Islands to Torishima (Senkaku-type) and native birds on Torishima (Torishima-type) and found significant differences in morphological characteristics between the 2 bird types. In general, Torishima-type birds were larger than Senkaku-type birds, whereas Senkaku-type birds had relatively longer beaks. Based on the morphological differences found in this study as well as genetic and ecological differences revealed in previous studies, we believe that Senkaku- and Torishima-type birds should be classified as different cryptic species. To the best of our knowledge, this is the first case of cryptic species being identified in a threatened avian species.

Monkeys mutant for PKD1 recapitulate human autosomal dominant polycystic kidney disease

Autosomal dominant polycystic kidney disease (ADPKD) caused by PKD1 mutations is one of the most common hereditary disorders. However, the key pathological processes underlying cyst development and exacerbation in pre-symptomatic stages remain unknown, because rodent models do not recapitulate critical disease phenotypes, including disease onset in heterozygotes. Here, using CRISPR/Cas9, we generate ADPKD models with PKD1 mutations in cynomolgus monkeys. As in humans and mice, near-complete PKD1 depletion induces severe cyst formation mainly in collecting ducts. Importantly, unlike in mice, PKD1 heterozygote monkeys exhibit cyst formation perinatally in distal tubules, possibly reflecting the initial pathology in humans. Many monkeys in these models survive after cyst formation, and cysts progress with age. Furthermore, we succeed in generating selective heterozygous mutations using allele-specific targeting. We propose that our models elucidate the onset and progression of ADPKD, which will serve as a critical basis for establishing new therapeutic strategies, including drug treatments.

A Standing Function Evaluation System Based on Virtual Light Touch Contact and Factor Analysis

This paper proposes a standing function evaluation system on the basis of factor analysis for indices related to standing characteristics. For this approach, five standing function factors were checked in a large-scale experiment using the results of extraction from 48 indices based on factor analysis. Five factors were extracted from these indices, and the related score radar charts indicated that most factors changed with age. The evaluation results suggest that the system facilitates intuitive comprehension of standing-related factors based on these charts.

Feature Selection for Work Recognition and Working Motion Measurement

As the demand for nursing care services is growing, the physical burden involved in caregiving has drawn widespread attention. To mitigate the physical burden in caregiving, we have to recognize what kind of work and problems are involved in each caregiving task. To identify the problems involved in caregiving, we need to recognize the work and analyze its workload. Aiming to reduce the burden on the waist during caregiving tasks, we are developing inertial sensor suits for measuring the working motions. With the developed method, the burden on the waist is estimated from the waist posture. Considering its use in practical caregiving sites, the number of inertial sensors should be the minimum necessary, which depends on the number of body parts where to measure the posture. In this study, we select the body parts to achieve the two above-mentioned goals: to recognize the work involved in caregiving and capture the waist posture. A support vector machine (SVM) is used to recognize the work. Its conventional method of selecting the features on which to recognize the work only considers the recognition accuracy and does not sufficiently meet the needs for measuring the postures. Therefore, we propose a new feature-selection method, which can evaluate the waist-posture measuring accuracy and can make forward feature selections in the same manner as the conventional wrapper method. We have verified the effectiveness of the proposed method by measuring simple simulated work motions.

Diurnal Variation of Melatonin Concentration in the Cerebrospinal Fluid of Unanesthetized Microminipig

BACKGROUND/AIM

The aim of this study was to develop a method for sequentially collecting cerebrospinal fluid (CSF) from an unanesthetized microminipig, which shares many physiological and anatomical similarities with humans, such as diurnality, and investigate the diurnal variation of melatonin concentration in the CSF.

MATERIALS AND METHODS

A catheter was placed percutaneously into the subarachnoid space of an anesthetized animal, and the tip of the catheter was placed into the cisterna magna under X-ray. We then sequentially collected CSF at light-on and -off times from the unanesthetized animal for several weeks. After catheter placement, a period of one week or more was necessary to relieve the contamination of RBCs in the CSF.

RESULTS

A higher melatonin level in the CSF was noted during lights-off time, and the level was higher than that in the serum.

CONCLUSION

This model of sequential collection of CSF will contribute to research in brain functions.

Validity and responsiveness of the work functioning impairment scale (WFun) in workers with pain due to musculoskeletal disorders

Objective:

To determine the convergent validity and responsiveness of the work functioning impairment scale (WFun) in workers with musculoskeletal disorder-related pain.

Methods:

Participants were extracted from an internet user study and prospectively examined using the pain intensity numerical rating scale (pain-NRS), the work ability numerical rating scale (productivity-NRS), and the WFun at baseline, 2 weeks, 6 weeks, and 3 months. The convergent validity and responsiveness of the WFun were examined by multilevel regression analysis.

Results:

A total of 786 workers participated and 593 completed all surveys. The WFun score gradually increased and decreased as the pain-NRS and the productivity-NRS increased, respectively. Changes in the WFun score steadily increased and decreased as changes in the pain-NRS and the productivity-NRS increased, respectively. Multilevel analyses showed that all linear associations were significant.

Conclusions:

The convergent validity and responsiveness of the WFun were consistent with the expected direction and magnitude.

[A Case of Intraductal Pancreatic Mallignant Tumor with Difficulty in Differentiating between IPMN and ITPN]

The patient was a male in his early 60s. Diabetes had aggravated 6 months earlier, and the patient was referred to our hospital for close examination. On contrast CT, enhanced mass shadows filling the lumen of the main pancreatic duct, which was dilated throughout the pancreas, were observed, and the mass was diagnosed as an adenocarcinoma on EUS-FNA. Based on these findings, main-duct IPMN was suspected and total pancreatectomy was performed. On macroscopic observation of the resected specimen, outgrowth of a solid tumor was observed in the main pancreatic duct, whereas only low-level mucus retention was noted in the pancreatic duct. Histopathological examination revealed a papillary/tubular tumor growth, suggesting interstitial infiltration throughout the pancreas. On immunostaining, the tumor was partially positive for MUC5AC, based on which the patient was diagnosed with an intraductal pancreatic mallignant tumor, with difficulty in differentiating between IPMC and ITPC. Clinicopathologically, many aspects regarding ITPN remain unclear. Further accumulation of such cases and investigation of the tumor pathology are necessary.

Effects of Diets with Different Proportions of Protein/Carbohydrate on Retinal Manifestations in db Mice

BACKGROUND/AIM

Diabetic nephropathy is aggravated by a higher intake of total protein. The effects of diets with different proportions of protein and carbohydrate on diabetic retinopathy in db mice, a type-2 diabetes animal model, were examined, as well as diabetic nephropathy.

MATERIALS AND METHODS

Control and db mice at 5 weeks of age were fed the diets (% energy of protein/carbohydrate/fat; L-diet: 12/71/17; H-diet: 24/59/17) under ad libitum conditions and pair-feeding conditions for 6 weeks, respectively.

RESULTS

Mice fed the H-diet showed significantly greater retinal thickness by optical coherence tomography, and lower mRNA levels of angiotensinogen. Comparing combinations of diets and genotypes, db-H mice showed significantly higher mRNA levels of angiotensin-converting enzyme, advanced glycosylation end product-specific receptor, and cluster of differentiation molecule 11b (a microglial marker) than db-L mice.

CONCLUSION

Dietary protein and carbohydrate proportions influenced retinal manifestations, including retinal thickness and gene expression in control and diabetic mice.

[Metastatic Pancreatic Carcinoma from Renal Cell Carcinoma Indistinguishable from Primary Pancreatic Endocrine Tumor - A Case Report]

A hypervascularized tumor was detected in a 65-year-old man who had underwent a nephrectomy for a right renal cell carcinoma at the age of 55 years. We diagnosed the tumor as a non-functioning pancreatic neuroendocrine tumor or a metastatic tumor from the renal cell carcinoma. We performed distal pancreatectomy with splenectomy and lymph node dissection. The tumor was histopathologically diagnosed as metastatic renal cell carcinoma.

Preoperative evaluation of accessory hepatic ducts by drip infusion cholangiography with CT

BACKGROUND

This retrospective study aimed to investigate the incidence of each type of accessory hepatic duct by drip infusion cholangiography with CT (DIC-CT).

METHODS

Five hundred sixty nine patients who underwent preoperative DIC-CT and laparoscopic cholecystectomy were reviewed. Accessory hepatic ducts were classified as follows: type I (accessory hepatic ducts that merged with the common hepatic duct between the confluence of the right and left hepatic ducts and the cystic duct confluence), type II (those that merged with the common hepatic duct at the same site as the cystic duct), type III (those that merged with the common bile duct distal to the cystic duct confluence), type IV (the cystic duct merged with the accessory hepatic duct), and type V (accessory hepatic ducts that merged with the common hepatic or bile duct on the left side).

RESULTS

Accessory hepatic ducts were observed in 50 patients. Type I, II, III, IV, and V accessory hepatic ducts were detected in 32, 3, 1, 11, and 3 patients, respectively. Based on their drainage areas, the accessory hepatic ducts were also classified as follows: a posterior branch in 22 patients, an anterior branch in 9 patients, a combination of posterior and anterior branches in 16 patients, a left-sided branch in 2 patients, and a caudate branch in 1 patient. None of the patients with accessory hepatic ducts suffered bile duct injuries.

CONCLUSION

There are a number of variants of the accessory hepatic duct. DIC-CT is useful to detect the accessory hepatic duct.

A randomized controlled trial of the effect of participatory ergonomic low back pain training on workplace improvement

Objectives:

This study aimed to determine the effects of participatory workplace improvement (PWI) -based provision of ergonomic training and ergonomic action checklists (ACLs) to on-site managers on workplace improvement activities for low back pain (LBP).

Methods:

A randomized controlled trial (RCT) was conducted at a manufacturing company in Japan. Teams entered in the study were randomly assigned to a control and an intervention group. A total of three interventional training sessions on methods of ergonomics were provided to on-site managers in the intervention group, with 1-month intervals between sessions. Ergonomic ACLs were provided at the same time. After completion of the training sessions, each team then provided a report of improvements each month for the next 10 months. Two people in charge of safety and health chose two major objectives of the implemented activities from the five categories. The reported number of improvements was analyzed using a Poisson regression model.

Results:

In the intervention group, although the incident rate ratio (IRR) of PWIs in countermeasures for the LBP category was significantly elevated after the training sessions, the IRR of improvements decreased over time during the 10-month follow-up period. No significant difference was observed in the IRR of total PWIs in either the control or intervention group.

Conclusions:

PWI-based provision of ergonomic training sessions and ergonomics ACLs to on-site managers was shown to be effective for workplace improvement activities targeted at LBP. However, because the effects decrease over time, efforts should be made to maintain the effects through regular interventions.

Idiopathic pulmonary hemosiderosis complicated by Down syndrome

We report the case of a 9-year-old girl with Down syndrome (DS) diagnosed with idiopathic pulmonary hemosiderosis (IPH). Although acute pneumonia complicated by hemolytic anemia was suspected, IPH was finally diagnosed on bronchoscopy. Treatment with prednisolone achieved good clinical response. An association between IPH and DS was not able to be identified, but immunological issues in DS may contribute to the onset of IPH. Recurrent and intractable respiratory symptoms with marked infiltrative shadows in the bilateral lungs and complicated by severe anemia in patients with DS should suggest IPH.

Bifidobacterium breve prevents necrotising enterocolitis by suppressing inflammatory responses in a preterm rat model

Necrotising enterocolitis (NEC) is associated with inflammatory responses and barrier dysfunction in the gut. In this study, we investigated the effect of Bifidobacterium breve M-16V on factors related to NEC development using an experimental rat model. Caesarean-sectioned rats were given formula milk with or without B. breve M-16V by oral gavage thrice daily, and experimental NEC was induced by exposing the rats to hypoxic conditions. Naturally delivered rats that were reared by their mother were used as healthy controls. The pathological score of NEC and the expression of molecules related to inflammatory responses and the barrier function were assessed in the ileum. B. breve M-16V reduced the pathological scores of NEC and resulted in some improvement in survivability. B. breve M-16V suppressed the increased expression of molecules related to inflammation and barrier function that resulted from NEC induction. B. breve M-16V normalised Toll-like receptor (TRL)4 expression and enhanced TLR2 expression. Our data suggest that B. breve M-16V prevents NEC development by modulating TLR expressions and suppressing inflammatory responses in a rat model.

Development and validity of a work functioning impairment scale based on the Rasch model among Japanese workers

OBJECTIVES

The purpose of this study was to develop a new work functioning impairment scale (WFun) and examine its validity.

METHODS

The WFun was developed based on the Rasch model, which consists of seven items. We conducted a pilot study (n=1,000) using an Internet investigation and a field study (n=1,294) in a manufacturing industry, and we additionally collected data from six workplaces from other industries. This series of studies was examined with a Rasch model analyses including item fit statistics as well as hypothesis testing. Convergent validity was used to examined the association of the WFun with the Stanford Presenteeism Scale, SF-8, Work Ability Index, and several types of job disruptions. We also examined differential test functioning.

RESULTS

All the items showed adequate fit (infit mean-square statistics <1.5). The item reliability was 0.98, and the item separation index was 6.37. The person reliability was 0.86, and the person separation index was 2.32. All tests for convergent validity showed significant differences. All p values derived from ANOVA were highly significant (p<0.001). No differential test function was observed between groups by age, sex, or job type or between various samples from different workplaces. The intraclass correlation of the estimated Rasch measurements from these groups was 0.99 (95% CI: 0.976-0.992).

CONCLUSIONS

The WFun was confirmed to show good fit to a Rasch model and construct validity. Given that its good fit indicates specific objectivity, this tool will be useful in assessing the ability of individuals to function at work and in evaluating group levels for benchmarking.

True left-sided gallbladder with variations of bile duct and cholecystic vein

A left-sided gallbladder without a right-sided round ligament, which is called a true left-sided gallbladder, is extremely rare. A 71-year-old woman was referred to our hospital due to a gallbladder polyp. Computed tomography (CT) revealed not only a gallbladder polyp but also the gallbladder located to the left of the round ligament connected to the left umbilical portion. CT portography revealed that the main portal vein diverged into the right posterior portal vein and the common trunk of the left portal vein and right anterior portal vein. CT cholangiography revealed that the infraportal bile duct of segment 2 joined the common bile duct. Laparoscopic cholecystectomy was performed for a gallbladder polyp, and the intraoperative finding showed that the cholecystic veins joined the round ligament. A true left-sided gallbladder is closely associated with several anomalies; therefore, surgeons encountering a true left-sided gallbladder should be aware of the potential for these anomalies.

Fabrication of electron beam deposited tip for atomic-scale atomic force microscopy in liquid

Recently, possibilities of improving operation speed and force sensitivity in atomic-scale atomic force microscopy (AFM) in liquid using a small cantilever with an electron beam deposited (EBD) tip have been intensively explored. However, the structure and properties of an EBD tip suitable for such an application have not been well-understood and hence its fabrication process has not been established. In this study, we perform atomic-scale AFM measurements with a small cantilever and clarify two major problems: contaminations from a cantilever and tip surface, and insufficient mechanical strength of an EBD tip having a high aspect ratio. To solve these problems, here we propose a fabrication process of an EBD tip, where we attach a 2 μm silica bead at the cantilever end and fabricate a 500-700 nm EBD tip on the bead. The bead height ensures sufficient cantilever-sample distance and enables to suppress long-range interaction between them even with a short EBD tip having high mechanical strength. After the tip fabrication, we coat the whole cantilever and tip surface with Si (30 nm) to prevent the generation of contamination. We perform atomic-scale AFM imaging and hydration force measurements at a mica-water interface using the fabricated tip and demonstrate its applicability to such an atomic-scale application. With a repeated use of the proposed process, we can reuse a small cantilever for atomic-scale measurements for several times. Therefore, the proposed method solves the two major problems and enables the practical use of a small cantilever in atomic-scale studies on various solid-liquid interfacial phenomena.

Visual recognition memory test performance was improved in older adults by extending encoding time and repeating test trials

OBJECTIVES

The aim of this study was to investigate whether the combination of extension of the encoding time and repetition of a test trial would improve the visual recognition memory performance in older adults.

METHODS

We evaluated visual memory performance in young and older adults on a Yes-No recognition memory test under four different conditions. The conditions consisted of combinations of encoding times of two and four seconds (E2 and E4) and first and second retrieval practice test trials (T1 and T2): E2T1, E2T2, E4T1 and E4T2. Performance was evaluated by measuring hit rates, false alarm rates, discrimination ability and response bias.

RESULTS

Older adults showed better improvement of hit rate and discrimination ability under the E4T2 conditions whereas young adults showed better memory performance under the E2T2 conditions.

CONCLUSIONS

A longer encoding time and repetition of the test was effective in improving the visual memory performance in terms of the hit rates and discrimination ability of older adults. The results suggest that this strategy should be useful in providing a suitable work environment for older workers.

Historical control data on developmental toxicity studies in rodents

Historical control data on rodent developmental toxicity studies, performed between 1994 and 2010, were obtained from 19 laboratories in Japan, including 10 pharmaceutical and chemical companies and nine contract research organizations. Rats, mice, and hamsters were used for developmental toxicity studies. Data included maternal reproductive findings at terminal cesarean sections and fetal findings including the spontaneous incidences of external, visceral, and skeletal anomalies. No noticeable differences were observed in maternal reproductive data between laboratories. Inter-laboratory variations in the incidences of fetuses with anomalies appeared to be due to differences in the selection of observation parameters, observation criteria, classification of the findings, and terminology of fetal alterations. Historical control data are useful for the appropriate interpretation of experimental results and evaluation of the effects of chemical on reproductive and developmental toxicities.

Rapid development of atherosclerosis in the world's smallest Microminipig fed a high-fat/high-cholesterol diet

AIM

Experimental studies of human atherogenesis require an appropriate animal model that mimics human physiology and pathology. Because swine physiology is similar to human physiology, we developed a hyperlipidemia-induced atherosclerosis model using the recently developed world's smallest Microminipig(TM).

METHODS

These animals weigh only 5kg at 3months of age, much smaller than any other miniature pig. We found that the administration of a high-fat/high-cholesterol diet containing at least 0.2% cholesterol without cholic acid for as little as eight weeks induces hypercholesterolemia and subsequent atherosclerosis in these animals.

RESULTS

The serum levels of low-density lipoprotein cholesterol(LDL-C) and the percent distribution of cholesterol in the LDL fractions were markedly increased. The hepatic expression of LDL receptor and hydroxymethylglutaryl-CoA reductase was coordinately decreased. The cholesteryl ester transfer protein activity, which plays a role in reverse cholesterol transport, was detected in the serum of the Microminipigs. Niemann-Pick C1-like 1 protein was expressed in both the liver and small intestine; however, hepatic apoB mRNA editing enzyme was not expressed. As in humans, and in contrast to that observed in mice, most of the hepatic lipase activity was localized in the liver. These results suggest that the hyperlipidemia-induced gene expression profile linked to cholesterol homeostasis and atherogenesis is similar in Microminipigs and humans.

CONCLUSION

We conclude that the characteristics of the Microminipig, including its easy handling size, make it an appropriate model for studies of atherosclerosis and related conditions.

Sex differences of serum lipid profile in novel microminipigs

Swine have been used extensively in biomedical research, with a significant increase in recent decades. Minipigs are increasingly becoming an especially attractive animal model in life science research because of their physiological and anatomical similarities to humans. The Microminipig (MMPig) has emerged as a novel and small minipig for non-clinical pharmacological/toxicological use. The MMPig is docile, weighs less than 10 kg in early maturity, and has an easily manageable size. In this study, we report on sex and age patterns in serum biochemistry parameters, including lipid analysis items and lipid profiles in healthy MMPigs. In total, 58 males and 67 females aged 0-34 months underwent serum biochemistry parameter measurements. Most parameters showed no effect of age or sex (although some did). Lipid analyses showed that the serum levels of total cholesterol, but not those of triglycerides (TG), were consistently higher in females at 0-34 months of age. Lipid profiles in 5-month-old MMPigs were investigated in greater detail. Serum low-density lipoprotein-cholesterol (LDL-C) values were higher in females. The percentage of LDL-C against total cholesterol was also higher, although high-density lipoprotein-cholesterol was lower, in females. There were no sex differences in the TG fraction. Although the sex difference in the serum lipid profile remains unexplained, the reference values obtained in this study could help facilitate the use of MMPigs in life science research.