Mdm2, but not Mdm4, protects terminally differentiated smooth muscle cells from p53-mediated caspase-3-independent cell death

p53 is a potent inhibitor of cell growth and an inducer of apoptosis. During embryonic development, Mdm2 and Mdm4 inhibit the growth suppressive activities of p53. However, whether tight surveillance of p53 activity is required in quiescent cells is unknown. To test this, conditional inactivation of mdm2 and mdm4 was carried out in smooth muscle...

Monoclonal gammopathies in aging μ,χ-transgenic mice: Involvement of the B-1 cell lineage

Monoclonal gammopathies (MG) are monoclonal proliferative disorders of B cells at the differentiation stage of Ig production. They can be detected in the serum, either as transient or as persistent homogenous immunoglobulin (H-Ig) components. The exact phenotype, localization, and cell lineage origin of the precursor cells of MG are unknown, but...

Squamous epithelial proliferative lesions associated with rhesus Epstein-Barr virus in simian immunodeficiency virus-infecte rhesus monkeys

HLA-B27 as a relative risk factor in ankylosing enthesopathy in transgenic mice

HLA-B27 is a risk factor for several human diseases through a mechanism that is not yet understood. This article describes a naturally occurring joint disease in laboratory mice, ANKENT. ANKENT begins with mild inflammation and culminates in irreversible stiffening of the ankle and/or tarsal joints in one or both hind paws. The macroscopic and...

Evidence for a diminished maturation of preosteoblasts into osteoblasts during aging in rats: An ultrastructural analysis

Bone is subject to continuous remodeling throughout life. The age-related loss of (trabecular) bone, leading to senile osteopenia, is mainly due to impaired bone formation. Osteoblasts (OB) and osteoclasts (OC) have been identified as playing a crucial role in the process of bone turnover, but the contribution made by their precursors is not...

Molecular mechanisms of ageing

A spontaneous mutation characterized by chronic proliferative dermatitis in C57BL mice

Chronic proliferative dermatitis is a new spontaneous mutation in C57BL/Ka mice. Breeding results suggest an autosomal recessive mode of inheritance. Mutant mice develop skin lesions at the age of 5 to 6 weeks. The lesions occur in the ventral and dorsal skin of the body, whereas ears, footpads, and tail are not involved. The lesions are...

Neurohypophyseal astrocytoma (Pituicytoma) in a rhesus monkey (Macaca mulatta)

Chemicals/CAS: Glial Fibrillary Acidic Protein; S100 Proteins; Vimentin

Flow cytometric DNA measurement and cytomorphometric analysis of formalin fixed rat mammary tumours

Archival paraffin embedded material was used to examine whether additional quantitative criteria would be helpful to discriminate between histologically benign and malignant rat mammary tumours. To this end nuclear DNA content expressed as DNA ploidy index (DI) was measured using flow cytometry (FCM). A total of 63 benign and malignant mammary...

Animal model of human disease. Multiple myeloma

Animal models of spontaneous and induced plasmacytomas in some inbred strains of mice have proven to be useful tools for different studies on tumorigenesis and immunoregulation. Their wide applicability and the fact that after their intravenous transplantation, the recipient mice developed bone lesions, led in some instances to an incorrect use...

Early and late effects of fractionated irradiation of the thorax of WAG/Rij rats

Gastrointestinal decontamination of dogs treated with total body irradiation and bone marrow transplantation

Procedures for total and selective gastrointestinal decontamination of dogs are described. The selective procedure removed only Gram negative aerobic bacteria, yeast and fungi. Dogs receiving total decontamination were less susceptible to the GI syndrome following total body irradiation (TBI) than dogs receiving conventional care. After TBI and...

Tumor induction in rats by simian sarcoma associated (helper) virus and rescued murine sarcoma virus: abstract

Idiopathic paraproteinemia. II. Transplantation of the paraprotein- producing clone from old to young C57BL/KaLwRij mice

Transplantation experiments in the C57BL/KaLwRij mouse model of idiopathic paraproteinemia (IP) showed that an IP-producing clone can be further propagated in young, lethally irradiated mice and also equally as well in nonirradiated recipients by a bone marrow and/or spleen cell transfer. The latency period before the original paraprotein was...

Type-C oncovirus isolate from human leukemic bone marrow: Further in vitro and in vivo characterization

Rabbit corneal cells transformed by a putative human type-C helper virus pseudotype of the mouse sarcoma virus produce large amounts of transforming and non-transforming viruses. The virions are antigenically related to the woolly monkey (simian) sarcoma-leukemia type-C oncovirus. Typical sarcoma virus lesions developed in newborn rats injected...

Naturally occurring endocardial disease in the rat