[Whole-body MR imaging for evaluation of bone marrow cellularity in aplastic anemia].

The aim of this study was to investigate the usefulness of whole-body MRI(WB-MRI) in the evaluation of cellularity in bone marrow and the distribution of fatty marrow in aplastic anemia. WB-MRI was performed on five patients with aplastic anemia who ranged in age from 62 to 70 years of age, and on four controls with malignant lymphoma who ranged in age from 59 to 67 years. Coronal images were obtained using a body coil with an FOV of 48 cm x 48 cm, and with both fast short T1 inversion recovery(STIR) and spin-echo T1-weighted(T1-WI) in three regions: (1) head to thorax, (2) abdomen to pelvis, and (3) lower extremities. The findings on WB-MRI were compared with those of histological studies of bone marrow at the sternum and the posterior iliac crest. The results were as follows: (1) there was a correlation between the cellularity of histological studies of bone marrow and signal intensity on WB-MRI; (2) WB-MRI could detect the activity of bone marrow; and (3) in a comparison of signal intensity in aplastic anemia and control subjects, there were differences of signal intensity in the central marrow.

Effect of loading on the development of nerve fibers around oral implants in the dog mandible.

Occlusal forces cause stress which morphologically affects the supporting tissues of implants. The aim of this study was to examine the effects of occlusal forces on the distribution of neurofilament protein (NFP)-positive nerve fibers in the tissue of peri-implant bone. The bilateral 2nd, 3rd and 4th mandibular premolars and the 1st molars were extracted from three mongrel dogs. After 4 months of healing, 4 screw-type implants were inserted in the oral cavity. Three months after insertion, the implants on the molar site were loaded by occlusal forces, while those on the premolar site were unloaded. After a further 3 months, the dogs were sacrificed, and specimens were prepared for immunohistochemical NFP-positive staining by the labeled-streptavidin-biotin method. Many NFP-positive nerve fibers were found in the tissues of the loaded site when compared with the unloaded site. These fibers were localized in both the bone marrow space and in the peri-implant fibrous tissue. They had two types of nerve endings: simple free nerve endings, and nerve endings with tree-like ramifications. The present results suggest that loading by occlusal force causes an increase in the number of NFP-positive nerve fibers, many of which have free nerve endings in the peri-implant tissue. The possible role of these NFP-positive nerve fibers is discussed.

Non-grafting method of vaginal construction for patients of vaginal agenesis without functioning uterus (Mayer-Rokitansky-Küster syndrome).

We have treated 18 patients with vaginal agenesis without functioning uterus (MRK syndrome) during the period between January 1984 and December 1995 by Frank's dilatation method followed by the surgical method without grafting. Clinical records were retrospectively examined in regard to the size and functions of the constructed vagina and problems of the treatment procedure. The treatment by non-invasive dilatation was first carried out starting at the age of 21 years 2 months +/- 2 years 9 months (Mean +/- SD) for the duration of 10.9 +/- 9.8 months. It was successful (constructed vaginal length by pressure: 60 mm or more) in 6 patients (35.3%). The non-grafting surgical method was then performed. The operation time was 2:11 +/- 0:37 hours and no complications were observed. The vaginal lengths 1 month after operation and at the latest follow-up were enough to have coitus and no severe complications including shrinkage were observed. Our method to construct a new vagina is simple and useful, since it left no operation scar in contrast to McIndoe's method and other methods with grafting.

[On the diploic epidermoid: report of two cases].

Primary epidermoid tumors comprise about 1% of all central nervous system neoplasms, although the diploic epidermoid tumor is comparatively rare. Two cases of diploic epidermoid tumor are reported in this paper. Case 1: A 70-year-old man presented with a headache. A plain craniogram showed an osteolytic lesion of the occipital bone with a well defined sclerotic margin. A contrast enhanced CT confirmed a cystic lesion with rim enhancement. On MRI, the tumor appeared hypointense surrounded with irregular hyperintensity on the T1WI and hyperintensity on the T2WI. Gd enhancement on the MRI showed no enhancement effect. The tumor was totally removed and cranioplasty was performed. No tumor invasion of the dura mater was noticed. Case 2: A 90-year-old woman presented with a giant tumor of the left parietal region. She noticed a painless swelling at the age of 20, and the tumor slowly grew over a period of 70 years. Plain craniogram showed a bony defect with a sclerotic margin. CT scan confirmed an extracranial giant tumor with destruction of the outer table under the tumor, and also falx meningioma. Aspiration and irrigation inside the cystic tumor were performed under local anesthesia. Previous authors have also said that the plain craniogram is characteristic and diagnostic in the case of diploic epidermoid. Typical round or polylobular bony defect with well defined sclerotic margins was visualized.

[A case of malignant schwannoma of the mesentery in a patient with von Recklinghausen's disease].

A 23-year-old man with Von Recklinghausen's disease was admitted because of abdominal pain. The preoperative diagnosis was malignant mesenteric tumor. Laparotomy was done and the tumor was located in the mesentery of the ileum which showed numerous tortuous cords or bulbous projections from the surface. Partial resection of the involved ileum and the mesentery was performed. Histological examination revealed plexiform neurofibroma and malignant Schwannoma of the mesentery. It is very difficult to preoperatively diagnose early associated lesions of Von Recklinghausen's disease. Therefore, careful examination of the GI tract is important so that earlier therapy can be carried out.