An unusual stress fracture of the lateral tibial plateau

Summary Stress fracture of the lateral tibial plateau is a rare occurrence. In this article we report a case of stress fracture of the lateral tibial plateau with a radiolucent fracture line in a 52-year-old man. To our knowledge, such a case has not yet been reported.     

Sigmoidoscopy and other tests for screening of colorectal cancer

We have been carrying our mass detection for colorectal cancer with fecal occult blood test and sigmoidoscopy. The occult blood test is negative in 60% with colorectal cancer.     

Malignant Schwannoma Arising in Patients with Von Recklinghausen's Disease: Report of Two Cases and the Comparison of Mast Cells between Benign and Malignant Portions

We described two cases of malignant schwannoma arising in patients with von Recklinghausen's disease and examined the mast cells infiltrated into histologic sections. One of the two cases histologically revealed apparent mast cell infiltration in some areas of malignant schwannoma as well as in the benign neurofibroma. The malignant lesion demonstrated significantly increased percentages of degranulated mast cells over the benign lesion using FITC-avidin staining. In an electron microscopic study, mast cells in the malignant lesion displayed empty granules, piecemeal degranulation, and canaliculi structures suggesting activation. These findings were not observed in the benign lesion. The other patient histologically showed no mast cells in the malignant lesion, although the benign neurofibroma in the patient disclosed numerous mast cells. The first patient had neither recurrence nor distant metastasis. On the other hand, the second patient without mast cells in the histology had multiple distant metastases. These findings raise questions about the role of mast cells in malignant schwannoma.     

Mesenchymal chondrosarcoma of the rib: Report of a case

Mesenchymal chondrosarcoma is a rare malignant cartilaginous tumor arising within the bone or soft tissue. An 18-year-old woman presented with a tumor on her left fourth rib. We performed a wide resection of the tumor and administered three cycles of postoperative adjuvant chemotherapy. Three years after the operation, the patient is alive without any evidence of either local recurrence or distant metastases. The findings of this case may thus support the usefulness of a radical resection and adjuvant chemotherapy for mesenchymal chondrosarcoma.     

Metabolite 1 of protopanaxadiol-type saponins, an axonal regenerative factor, stimulates teneurin-2 linked by PI3-kinase cascade.

We previously showed that 20-O-beta-D-glucopyranosyl-20(S)-protopanaxadiol (M1), a metabolite of protopanaxadiol-type ginseng saponins by intestinal bacteria had axonal extension activity in degenerated neurons, and improved memory disorder and synaptic loss induced by an active fragment of amyloid beta, Abeta(25-35). It is unknown how M1 shows these effects in neurons. To clarify the signal transduction mechanism of M1-induced axonal extension, phosphorylated proteins by M1 stimulation were identified because most cellular signal pathways are regulated by phosphorylation/dephosphorylation. The combination of immunoprecipitation and MALDI-TOF-MS revealed that teneurin-2 and mPar3 were specifically phosphorylated by M1 stimulation. Because mPar3 is known as an axonal specifying molecule and to be regulated by phosphatidylinositol 3-kinase (PI3-kinase), the involvement of teneurin-2 and PI3-kinase in the M1 signal was studied. In teneurin-2-deficient cortical neurons, M1-induced axonal extension and PI3-kinase activation were significantly inhibited. In addition, treatment with PI3-kinase inhibitor also reduced M1-induced axonal extension. These results suggest that M1 induces axonal outgrowth through the teneurin-2-PI3-kinase cascade.     

A clinical study of testicular tumors

Fifty-eight of the 44,698 patients seen at our Department, between 1972 and 1984 had a testicular tumor. The incidence rate was 0.13%. The mean age of these 58 cases was 28.6 years and two peak distributions, one in the 0 to 5 year and another in 26 to 30 year age group were observed. Among them, 54 patients (93.1%) had chief complaints of painless testicular swelling at initial examination. The vast majority of them had unilateral tumors; 28 in the right and 29 in the left. Only one patient had bilateral seminomas. Histologically, 30 of them (51.7%) were seminoma, 8 were embryonal carcinoma (13.8%), 2 were teratoma (3.5%) and the remaining 18 had tumors of double or multiple histological type. Most of the seminomas were treated by a combination of high orchiectomy and radiotherapy, and chemotherapy was done mainly for non-seminomatous cases. The 5-year survival rate calculated by the Kaplan-Meier method was 100% for patients with low stage (I, II) seminomas and 62% for those with non-seminomatous tumors.