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T Iwasawa

Publications and source records attributed to T Iwasawa.

At least 19 recordsLinked to original sources
PubMed1992

Stimulation by interleukin-1 of interleukin-6 production by human periodontal ligament cells.

Interleukin-1(IL-1), a cytokine present in the gingiva and crevicular fluid of patients with periodontitis and in the periodontal ligament (PDL) of experimentally moved teeth, has multiple biological activities, including the ability to elicit bone resorption. Interleukin-6, also found in the gingiva of patients with periodontitis, may induce osteoclastic bone resorption through an effect on osteoclastogenesis. Here IL-6 production and its gene expression in response to recombinant IL-1 beta were examined in primary cultures of PDL cells. IL-1 beta stimulated IL-6 production by these cells in a dose- and time-dependent manner; this increase in IL-6 production was much higher than that in human gingival fibroblasts. In situ hybridization, using a synthetic oligonucleotide DNA probe of the IL-6 gene, revealed that most PDL cells expressed IL-6 mRNA in response to IL-1 beta treatment. The finding that IL-6 is produced by PDL cells and is regulated by IL-1 beta has revealed a potentially important mechanism for controlling alveolar bone resorption.

Cells, Cultured↗
PubMed1991

[Ewing's sarcoma in the retroperitoneum].

The patient was a female aged 18. Hematuria was discovered at an examination two years previously at which time the patient was complaining of right lumbar pain. The patient visited our hospital with a chief complaint of right abdominal tumor in June, 1988. A retroperitoneal tumor, 77 X 45 mm in size, was observed by CT and ultrasonic examination, and the right kidney was in hydronephrosis. An operation was performed in September, 1988, based on a diagnosis of retroperitoneal tumor and hydronephrosis. The tumor was seen to have involved the right ureter. Subsequently the tumor was surgically removed; right total nephroureterectomy and partial cystectomy were performed at that time. The removed tumor was 90 X 70 mm in size and 120 g in weight; it was histopathologically diagnosed as extraskeletal Ewing sarcoma. A systemic examination was carried out postoperatively, but no abnormalities were observed. As of September, 1990, the patient had had no recurrence and was being kept observation on an outpatient basis. There have been a total of 210 case reports regarding extraskeletal Ewing sarcoma published worldwide, including our case and 26 cases in Japan, so far as we know. However those of a lesion of retroperitoneal origin are extremely rare, numbering only 11 cases worldwide and 2 Japan. Herein we report our case of extraskeletal Ewing sarcoma with reference to the other 209 cases reported in the literature to date.

Adolescent↗
PubMed1991

Hyperthermic purging in vitro of murine leukemia cells (MK-8057): surviving fractions of normal and leukemic stem cells and the long-term survival of mice injected with the post-hyperthermic leukemia cells.

Hyperthermic purging of leukemic cells has been applied in clinical trials, although an accurate evaluation system to compare the effect on leukemia cells with that on normal hemopoietic cells has not been established. We evaluated the heat-sensitivity of murine leukemia cells, MK-8057, and compared differences in heat-sensitivity between surviving fractions of leukemic stem cells (leukemic spleen colony-forming units, L-CFU-S) and normal hemopoietic stem cells (spleen colony-forming units, CFU-S). Using the spleen colony assay, the survival fraction of L-CFU-S was compared with that of CFU-S after various hyperthermic treatments. One of the most efficient conditions, that is, hyperthermia at 42 degrees C for 3 h, allowed only 0.17% of L-CFU-S to survive, whereas 26.5% of normal CFU-S survived. Hyperthermia at 44 degrees C for 45 min further reduced the L-CFU-S (0.13%); however, the relative ratio of L-CFU-S to CFU-S was less than that at 42 degrees C for 3 h, because there was a larger reduction at 44 degrees C in normal CFU-S (5.1%). Recipient mice injected with MK-8057 cells treated with hyperthermia survived longer in proportion to the decreasing number of surviving L-CFU-S injected. This extension of the survival of recipient mice given MK-8057 cells after hyperthermia was also proportional to the estimated survival fraction of L-CFU-S. The survival fraction of MK-8057 cells after hyperthermia that was independently calculated through the extended survival of the recipients showed a good correlation with the surviving fraction of L-CFU-S, seen as the leukemic spleen colonies, at a correlation coefficient of r = 0.985. The number of surviving mice receiving the post-hyperthermic MK-8057 cells and the number of L-CFU-S calculated to have been injected had a relationship based on a Poisson distribution. Thus, the calculated results imply that the hyperthermia proportionally targets L-CFU-S, which are the only cells responsible for killing the recipient mice.

Animals↗
PubMed1990

Progressive shrinkage of the thalamus following middle cerebral artery occlusion in rats.

Permanent middle cerebral artery occlusion in rats results in infarction in the ipsilateral cortex and caudate nucleus-putamen. In this ischemia model, severe shrinkage of the ipsilateral half of the thalamus was observed several months after surgery. We examined the serial profile of this phenomenon in 40 rats at intervals from 2 weeks to 6 months after the operation. The area of the ipsilateral half of the thalamus as a percentage of the area of the contralateral half was 87% at 2 weeks, 77% at 1 month, 54% at 3 months, and 54% at 6 months. Such severe morphologic change distant from the original ischemic focus has not been reported in models of experimental focal ischemia. Retrograde degeneration is thought to play an important role in this phenomenon.

Animals↗
PubMed1990

Effect of multiple-dose irradiation on repair capacity in plateau phase C3H 10T1/2 cells.

Using plateau phase C3H 10T1/2 cells, we studied the effect of multiple-dose irradiation on the repair capacity of cells after further irradiation. Cells were irradiated with repeated doses of 2.5 Gy delivered two fractions per day at 6 to 7 hours interval. The cell survival after exposure to 1 to 9 fractions was lower above 5 fractions as compared to that predicted by calculating from single dose survival curve by assuming that cells retain their capacity to repair radiation damage after each fraction. Repair kinetics experiments showed that cells were less able to repair potentially lethal damage after test dose following multiple dose irradiations. There was, however, no difference in the ability to repair sublethal damage and potentially lethal damage sensitive to anisotonic treatment in preirradiated and untreated cells. Thus, it would appear that an enhancement of the lethal expression of potentially lethal damage of three types of damage may, at least in part, contribute to the difference between the cell survival curve after multiple fractions and that predicted by calculation.

Animals↗
PubMed1990

[Correlation between morphologies of mandibular vertical sections and linear measurements of the skull].

The purpose of this study is to evaluate the relationships between the sectional forms of the mandible and the craniofacial morphology. Vertical sections were made at the symphysis (SY) and at the second molar region (M2R). Materials were dried human skulls which were measured in three dimensional co-ordinate system. The correlation matrix of 24 measurements was examined in the male and the female. The difference of these measurements between the low angle group and the high angle group of gonial angle was also examined. Results obtained were as follows: 1. Gonial angle was negatively correlated with the height, width, breadth of ramus and the breadth of second molars. SY form was related to the facial height and size of the mandible. On the other hand, M2R form was related to the height, width and breadth of ramus. 2. The differences of measurements between the low angle group and the high angle group of gonial angle were as follows: 1) The ramal height, ramal width, bicondylar width and breadth of second molars in the low angle group were significantly larger than those in the high angle group. 2) The measurements of SY in the high angle group and the low angle group showed no significant difference. 3) The height and area of M2R in the low angle group were significantly larger than those in the high angle group. This study demonstrated that SY form might relate to vertical factors of the face (facial height), the size of mandible and the types of occlusions. On the other hand, M2R form being nearer to the attachment of masseter and medial pterygoid muscles than SY was related to the form of ramus and the gonial angle.

Cephalometry↗
PubMed1990

[Effects of the newly developed mandibular retraction system in a rat].

Authors have developed a mandibular retraction system in a rat that was constructed by arms having a metal mesh, an incisor metal cap, a pair of closed coil springs and a soft plastic collar. The merit of this system is that the anchor is very stable because it is made on the parietal bones, and the direction and load of the traction are invariable regardless of head position of the rat compared to the previous methods in which the anchor was made on the neck collar of a rat. Seventy of 8-week-old male Wistar rats were divided into five groups that were intact, collar, sham operation, straight-pull and high-pull. The anchor was implanted with a metal mesh into the subperiosteal space of the parietal bones just in front of the lambda suture of a rat. The coil spring attached on the sliding hook on the arm was connected with a hook soldered with an incisor metal cap. Therefore, the mandible was retracted in the TMJ direction (straight-pull) and some were 20 degrees upper than TMJ (high-pull) for 15 days at a tension of 10 g. All operations except for traction by the coil springs were performed on a rat in the sham operation group. Only the plastic collar was set on the neck in the collar group. Mandibular retraction for 15 days showed significant inhibition of the sagittal growth of the mandible in both high- and straight-pull groups. No inhibition of sagittal cranial growth was observed according to morphometrical and microscopical investigations.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1990

[A case of malignant mesenchymoma of the maxilla].

The case of a 48-year-old male with a malignant mesenchymoma of the maxilla is reported. The patient had complained of bloody rhinorrhea and cheek pain, and a total maxillectomy was performed. The tumor consisted of a rhabdomyosarcoma, an osteosarcoma and a chondrosarcoma, which were relatively differentiated. Later, recurrence of a tumor and a lung metastasis occurred, however the tumor revealed undifferentiated mesenchymal cells. This led us to suspect the origin of the malignant mesenchymoma had been a primitive mesenchymal cell. To our a knowledge, the present case is the first reported case of a malignant mesenchymoma with a maxillary origin in the world.

Chondrosarcoma↗
PubMed1989

[High-resolution ultrasound of the thyroid in patients with Graves' disease].

The thyroid glands in 53 patients with Graves' disease were scanned with 10-MHz high-resolution ultrasound. Homogeneous echo pattern was noted in 21 patients (39.6%), and heterogeneous echo pattern was noted in 31 patients (60.4%). Each mean value of the serum triiodothyronine (T3), thyroxine (T4), and free thyroxine (Free T4) in patients with heterogeneous-echo thyroid was noted higher than that of the group with homogeneous-echo thyroid. (p less than 0.05) However, between the two groups, there is no significant difference in mean age and mean duration of treatment with antithyroid drugs. The heterogeneous echo pattern is strongly suggested to be correlated with the severity of hyperthyroidism.

Adolescent↗
PubMed1989

[Consideration to the experimental study on the rapid palatal expansion in the rat].

The purpose of this study is to clarify the most suitable position and method to investigate bone formation in the mid-palatal suture after rapid palatal expansion in the rat. 10 of 8 week-old Wistar rats were employed to observe the structure of the normal mid-palatal suture at the line connecting the incisors, the anterior end of the anterior palatine foramen, the line bisecting the anterior palatine foramina, and the line of the 1st molars. A mid-palatal suture of 8 week-old Wistar rats was expanded laterally for 6 days by means of maxillary incisor expansion apparatus with a spring of 60 g load. After beheading, soft X-ray picture of the skull was taken to observe the suture. The maxilla was removed and decalcified sections (frontal section) were prepared. They were stained with hematoxylin and eosin for microscopy. The mid-palatal suture was observed at 4 levels to the lines drawn as follows; the line running through the centers of incisors (A), the line running the anterior ends of the anterior palatine foramen (B), the line running through the center of the anterior palatine foramen (C), and the line running through the centers of the 1st molars (D). At the opposing margins of A and B, the suture was composed of two layers; the layer of osteoblasts and the layer of interconnecting Sharpey's fibers. At C, the suture was curved and the layer of Sharpey's fibers were made up with longitudinal as well as transverse fibers.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1989

[Multiple cerebral venous angiomas associated with mixed pial and dural arteriovenous malformation].

Venous angioma is a relatively rare entity of vascular malformations of the brain and usually found as a solitary lesion. Cases of multiple lesions and/or coupled with other vascular malformations are extremely rare. We present the first case of multiple supratentorial venous angiomas associated with mixed pial and dural arteriovenous malformation (AVM) fed by the posterior cerebral artery, the occipital artery and the posterior meningeal artery.

Adolescent↗
PubMed1977

Tweed triangle and soft-tissue consideration of Japanese with normal occlusion and good facial profile.

A total of thirty-six Japanese adult subjects (consisting of eighteen men and eighteen women) with normal occlusion and harmonious facial features were subjected to cephalographic examination for the purpose of studying their soft tissues. Out of this group, twenty were selected and compared with twenty Class II, Division 1 and twenty Class III patients for the purpose of establishing an appropriate diagnostic guide for the Tweed triangle. These are our conclusions: 1. The Z angle of the Japanese subjects with normal occlusion was 69.70 degrees for the men and 71.75 degrees for the women. There is no significant difference between the sexes. 2. Although there are no significant differences between the sexes for the integumental and total chins, there is slight sexual difference for the upper lip measurement. 3. As compared to the subjects with normal occlusion, there is a significant difference for the Z angle of Class II, Division 1 and Class III patients. 4. In this study, the measurements of the Tweed triangle were FMA 27.28 degrees, IMPA 95.50 degrees, and FMIA 57.22 degrees. On the basis of this study and the reports of other Japanese investigators, we would like to suggest an FMIA of 57 degrees as being the most suitable basis for the diagnosis of Japanese patients, but this should be modified according to the FMA value.

Adult↗