Intra-articular angioleiomyoma of the knee: a case report.

We report a rare case of angioleiomyoma that occurred in the intra-articular portion of the knee joint. A 43-year-old female was referred to us with a 3-year history of recurrent pain and a loss of full extension of the right knee. Physical examinations revealed swelling and restriction of active full extension. Magnetic resonance imaging (MRI) revealed an intra-articular tumor. Surgical excision was performed, and the histology was characteristic of an angioleiomyoma. The patient became asymptomatic after the operation. At 2-year follow-up after the operation, no recurrence has developed.

Localization of Neurensin1 in cerebellar Purkinje cells of the developing chick and its possible function in dendrite formation.

Neurensin1 (Nrsn1) gene, highly specific to neurons, has been considered to play a role in neurite growth during neuronal development and regeneration in mice. Intense expression of Nrsn1 was found particularly in projecting neurons like retinal ganglion cells and spinal motor neurons, suggesting that Neurensin1 is needed for active neurite growth. In the present study we cloned chick Nrsn1 gene and produced an antibody against cNrsn1 to examine Nrsn1 localization in the chick brain, since the chick is a suitable animal model for the study of developmental neurobiology. We found that there are neurons intensely stained for Nrsn1 antibody localized in the optic tectum, the cerebellum and the brain stem. These neurons are large in size and considered to be projecting neurons. In the cerebellum, Purkinje cells are the only one type of neurons stained for Nrsn1. During Purkinje cell development the arborized dendrites and axons become intensely stained at stages E17-18. A siRNA gene knock down was applied to the cultured embryonic cerebellar tissues and the result showed that Nrsn1 has an important role in dendrite formation of Purkinje cells. These findings suggest that Neurensin1 is also involved in neural development in the chick brain and that the embryonic chick brain is a good model to disclose the molecular and physiological functions of Nrsn1.

Regeneration of the hamstring tendons after harvesting for arthroscopic anterior cruciate ligament reconstruction: a histological study in 11 patients.

The purpose of our study is to evaluate whether the hamstring tendons can regrow after harvesting for anterior cruciate ligament (ACL) reconstruction and whether the regenerate tissue can be histologically characterized as tendinous. Eleven of the patients (eight female and three male; mean age, 23 years; range 17-37 years) consented to participate in this study. One year after the ACL reconstruction, surgical biopsy was done. Regeneration of the tendon was detected macroscopically in 9 of the 11 patients. Histologically and immunohistochemically, the regenerated tendons closely resembled normal ones. The results of this study show the hamstring tendons can regenerate after harvesting for the ACL reconstruction.