Immunodeficient mice are widely used for xenografts of human cells and tissue. The purpose of the present study was to investigate the characteristics of xenograft human tumor models using engraftment of various non-hematopoietic tumors in the NOD/SCID/gamma(c) (null) mouse. For tumor models, human solid tumor tissues were serially passaged three or more times to establish tissue lines. A total of 326 fresh tumor specimens, mainly gastrointestinal and female genital tissue, were engrafted with 54 established tissue lines. The types of tissue lines varied and included tumor tissue of both epithelial and mesenchymal origin. In some cases the original surgical specimen was replaced with large mononuclear cells. In the established tumor tissue lines, differentiation and tumor structure were similar to that of the original surgical specimen. The interstitium of the xenograft tissue in the tissue lines was relatively well preserved although slightly decreased and replaced by host tissue. These results indicate that human solid tumors can be successfully engrafted into the NOD/SCID/gamma(c) (null) mouse and that tissue lines with the characteristics of the original tumors can be established. Investigators in the field of tumor research will benefit from the availability of tissue lines that allow the establishment of more relevant in vivo human tissue models.

ABSTRACT. Bone mineral density (BMD), distribution of its density and bone histomorphometric parameters were evaluated in lumbar vertebra of normally growing miniature pigs. The fourth lumbar vertebra (L4) of the Göttingen miniature pig were used in this cross-sectional study in vitro. The BMD of the miniature pig was similar to that of humans in tendency of gender differences and some growth patterns during puberty. In these regards this animal appears useful as a model for human bone study. However, the trabecular and cortical BMDs of lumbar spine were extremely high value (399.43 ± 26.36 mg/cm 3 in female trabeculae; 973.06 ± 69.55 mg/cm 3 in female cortical bone; 419.04 ± 34.84 mg/cm 3 in male trabeculae; 1038.81 ± 125.72 mg/cm 3 in male cortical bone in pigs 30 months or more). Furthermore, histomorphometric analysis yielded values that were remarkably different from those found in humans. From these results, it was revealed that miniature pig had a higher bone mass and denser trabecular network than human, indicating that its bone is probably stronger. Therefore, care should be taken in choosing the miniature pig as a bone study model. KEY WORDS: bone mineral density, histomorphometric analyses, lumbar spine, miniature pig.J. Vet. Med. Sci. 66(6): 599-609, 2004 Metabolic bone diseases such as osteoporosis are becoming more important because of an aging society in human medicine. These diseases increase the risk of fragility fracture as bone mineral levels decrease, and also reduces their quality of life. Previous studies have reported that bone strength and fracture risk are closely related to bone mineral density (BMD) [6,9,27]. In contrast, several studies have suggested that changes in bone architecture increase fracture risk [29,31,33,34,43]. Therefore, it is necessary to study the changes in both BMD and architecture for more sensitive investigation of the bone disease.Quantitative computed tomography (QCT) has been widely investigated and applied in recent years as a means of non-invasive quantification of BMD. It has been reported that QCT might be most sensitive to changes in bone density caused by rapid bone turnover, such as in menopausal immobilization or hyperthyroidism [9]. QCT can selectively measure both trabecular and cortical bone [9,13,22,38], and the BMD is expressed in milligrams per cubic centimeter (volumetric density) [9]. Ebbesen et al. showed highly correlation between BMD by QCT and compressive strength in the lumbar vertebrae [9].Several studies have reported that bone disorders such as osteoporosis lead to trabecular and cortical bone alterations in humans. These alterations are characterized not only by a reduction of bone mass but also by structural changes in microarchitecture which is measured by histomorphometry of bone [29,31,33]. Therefore, it has been considered that histomorphometric analysis have an important role as contributor to bone strength, in addition to BMD.Recently, miniature pig has been noticed as for experimental animal of bone study. The pig is an excel...

Abstract. The purpose of this study was to examine fertilities from mating and artificial insemination (AI) with frozen-thawed spermatozoa by indexing the luteinizing hormone (LH) surge with the Canine Ovulation Timing Test (ICG Status-LH TM ) in beagle bitches. Eleven 2-8-year-old multiparous dogs were used for this experiment and blood was collected daily at 6-15 days after the onset of proestrus. Each serum sample was then used for detection of the LH surge. Five dogs were mated at 5 days after the LH surge. Whelping was successful in all dogs and litter size was 5.8 ± 1.9 (Mean ± SD). The remaining 6 dogs were artificially inseminated with frozen-thawed spermatozoa at 4, 5 and 6 days after the LH surge. Sperm motility after thawing was 49.6 ± 3.6%. All dogs whelped and litter size was 4.0 ± 3.0. These results suggest that fertilities from mating and AI with frozen-thawed spermatozoa are satisfactory by indexing the LH surge with the Canine Ovulation Timing Test in dogs and further demonstrate that the optimal period for insemination is around 5 days after the LH surge.

Leukemia inhibitory factor(LIF) is known to be a causative factor for cacbexia and thrombocytosis in nude mice bearing human cancer cells. In the present study, we investigated whether recombinant human (rh) LIF can induce these biological activities in a primate model. rhLIF was synthesized by the expression of LIF protein in Escherichia coli. rhLIF (5, 20, or 80μ/kg) was administered subcutaneously twice daily to cynomolgus monkeys for 14 consecutive days. A remarkable decrease of body weight (10%) was observed in the 80μg/kg/day group. Approximately two‐fold increases in platelet counts were observed at doses higher than 5 /μg/kg/day when compared with control counts. These biological effects disappeared soon after the cessation of rhLIF treatment. Macroscopically, a remarkable reduction in subcutaneous fatty tissues and severe splenomegaly were observed. The results of this study demonstrate that rhLIF induces weight loss and thrombocytosis in a primate model.

This study investigated the effects of pair housing on diurnal rhythms of heart rate and autonomic nervous activity in miniature swine. For this purpose, six adult Göttingen miniature swine were initially housed individually in an animal cage. Then, two of each swine were housed in a large cage together for 3 weeks. After that swine were separated into individual cages again.During this experimental procedure, electrocardiogram (ECG) was recorded with a Holter ECG recorder. Autonomic nervous activity was evaluated by power spectral analysis of heart rate variability. Heart rate and autonomic nervous activity clearly showed a diurnal rhythm in miniature swine housed in individual cages. When two swine were housed together, heart rate was significantly increased throughout the day and diurnal rhythm disappeared. Although these changes gradually recovered to basal levels, these parameters had not completely returned to basal levels even after 2 weeks. Heart rate was still higher than the initial level just after swine were re-housed in their own individual cages. Heart rate and autonomic nervous activity returned to basal levels about 2 weeks after re-housing. Further, heart rate in some swine decreased below their initial levels. These results suggest that it takes miniature swine at least 2 weeks to adapt to different circumstances. Furthermore, the power spectral analysis of heart rate variability can be used as a useful method in a study for answering controversial issues related to stress response.