Long-term effects of castration on the skeleton of male rhesus monkeys (Macaca mulatta).

While osteopenia (OPE) and osteoporosis (OPO) have been studied in various species of aging nonhuman primates and extensively in ovariectomized rhesus and cynomolgus macaques, there is virtually no information on the effects of castration on the skeleton of male nonhuman primates. Most information on castrated male primates comes from a few studies on the skeletons of eunuchs. This report used a subset of the Caribbean Primate Research Center's (CPRC) Cayo Santiago (CS) rhesus macaque skeletal collection to qualitatively and quantitatively compare the bone mineral density (BMD) of castrated and age-matched intact males and, thereby, determine the long-term effects of castration (orchidectomy) on bone. Lumbar vertebrae, femora, and crania were evaluated using dual-energy X-ray absorptiometry (DEXA or DXA) and digital radiography augmented, when fresh tissues were available, with autoradiography and histology. Results confirmed physical examinations of long bones that castration causes changes in the skeleton of male rhesus macaques similar to those found in eunuchs, including OPE and OPO of the vertebrae and femora, thinning of the skull, and vertebral fractures and kyphosis of the spine more severe than that caused by normal aging alone. Also like eunuchs, some castrated CS male rhesus monkeys had a longer life span than intact males or females. Based on these results and the effects of castration on other tissues and organs of eunuchs, on behavior, hormone profiles and possibly on cognition and visual perception of human and nonhuman primates, and other mammals, castrated male rhesus macaques should be used with caution for laboratory studies and should be considered a separate category from intact males. Despite these caveats, the castrated male rhesus macaque should make an excellent animal model in which to test hormone replacement therapies for boys and men orchidectomized for testicular and prostate cancer.

Articular cartilage development: a molecular perspective.

In this article, development of articular cartilage and endochondral ossification is reviewed, from the perspective of both morphologic aspects of histogenesis and molecular biology, particularly with respect to key signaling molecules and extracellular matrix components most active in cartilage development. The current understanding of the roles of transforming growth factor ß and associated signaling molecules, bone morphogenic proteins, and molecules of the Wnt-ß catenin system in chondrogenesis are described. Articular cartilage development is a highly conserved complex biological process that is dynamic and robust in nature, which proceeds well without incident or failure in all joints of most young growing individuals.

Adult variant of atypical teratoid/rhabdoid tumor: immunohistochemical and ultrastructural confirmation of a rare tumor in the sella tursica.

Atypical teratoid/rhabdoid tumor (AT/RT) is a distinctive neoplasm of young children characterized by diverse histology and fatal course. Adult presentation is rare. We describe the diagnostic problems associated with an AT/RT arising in the sellar region in a 46-year-old female. Vimentin, keratin, synaptophysin, CD34, SMA, PLAP, GFAP, S-100, NSE, desmin, MYF-4, LCA, and CD99 were performed on tissue obtained from the paraffin block. INI1 protein expression was immunohistochemically determined on tumor tissue. Electron microscopy was performed from the tissue block. The tumor was composed of large atypical "rhabdoid" cells having macronucleoli and abundant eosinophilic cytoplasm. Immunohistochemistry showed that the tumor cells were positive for vimentin, CD34, CD99, and reacted variably for keratin, synaptophysin, NSE, and SMA. All were negative for GFAP, S-100, desmin, MYF-4, and LCA. The tumor cells lacked nuclear expression of INI1. Electron microscopy revealed cells with large paranuclear intracytoplasmic collections of intermediate filaments. AT/RT should be considered when dealing with a malignant neoplasm with rhabdoid features, regardless of age. Immunohistochemistry is of importance in differentiating this entity from primitive neuroectodermal tumors (PNET) and carcinosarcomas. Lack of nuclear INI1 protein expression by immunohistochemical methods is required for a reliable diagnosis.