PURPOSE: To characterize PTEN gene alterations and their expressions during the development of osteosarcoma. MATERIALS AND METHODS: We studied the pattern of deletion, mutation and expression of PTEN in normal bone tissues, tumor samples of 22 patients of osteosarcoma, and 4 osteosarcoma cell lines (HOS, U2-OS, MG-63 and Saos-2). The tissue was analyzed for deletion and mutational inactivation of PTEN by polymerase chain reaction-single strand conformation polymorphism (PCR-SSCP) and direct sequence analysis, and examined for abnormalities in expression by immunohistochemistry. RESULTS: In this study, neither mutation nor deletion of PTEN was found. Expression of PTEN protein was increased, without deletion or mutation of the PTEN gene, in 22 patients of osteosarcoma and in 4 osteosarcoma cell lines. Nuclear staining was more intense than the cytoplasmic staining in normal bone tissues and osteosarcoma cell lines, but in osteosarcoma tissues PTEN was expressed mainly in the cyto-plasm. CONCLUSION: These results suggest that abnormal expressions of PTEN by differential compartmentalization may play a role in the development and progression of osteosarcoma, instead of genetic alterations of PTEN.
Bone and Bones ; Cell Line ; Cytoplasm ; Humans ; Immunohistochemistry ; Osteosarcoma* ; PTEN Phosphohydrolase ; Sequence Analysis

The aim was to evaluate the diagnostic utility of beta-amyloid positron emission tomography (PET) in elderly patients with cognitive impairment in the clinical setting. Five subjects underwent beta-amyloid PET imaging to explore the cerebral beta-amyloid deposition. The two male patients with minor neurocognitive disorder due to Alzheimer's disease, who displayed similar degree of cognitive impairment and medial temporal atrophy but different in apolipoprotein E4 status, both showed negative for beta-amyloid PET. On the other hand, a female major neurocognitive disorder due to probable Alzheimer's disease patient was tested positive for beta-amyloid PET, with increased beta-amyloid density in frontal and parietal lobes. Beta-amyloid PET was also used for the differential diagnosis of neurocognitive disorder from other psychiatric disorders in two elderly patients. The results were negative but assisted the diagnositic confirmation. A female patient was determined to be a case of late-onset schizophrenia and a male patient was determined as delirium due to minor traumatic brain injury, persistent. Beta-amyloid PET imaging was able to demonstrate cerebral beta-amyloid deposition in major neurocognitive disorder due to probable Alzheimer's disease in visual scale. However, further studies are needed for its clinical utility in the minor neurocognitive disorders. Moreover, beta-amyloid PET imaging may provide additional information in diagnosing primary psychiatric disorders with new onset in the old age.
Late Onset Disorders ; Aged* ; Alzheimer Disease ; Amyloid beta-Peptides ; Apolipoprotein E4 ; Atrophy ; Brain Injuries ; Delirium ; Diagnosis, Differential ; Electrons* ; Female ; Hand ; Humans ; Male ; Parietal Lobe ; Positron-Emission Tomography* ; Schizophrenia