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Biomedical subjects

S Kadoya

Publications and source records attributed to S Kadoya.

At least 19 recordsLinked to original sources
PubMed1992

Effect of mechanical pressure on the blood flow in human palatal mucosa measured by temperature controlled thermoelectrical method.

Mucosal blood flow in the human palate was measured by a temperature controlled thermoelectrical method based on the thermal conductivity of mucosal tissue using a blood flow monitor and a non-invasive surface probe. The effect of mechanical pressure on the palatal mucosal tissue was studied. Mechanical pressure (2.5, 5.0, 7.5, 10.0 or 15.0 g mm-2) to the mucosal surface was exerted circumferentially around the surface probe. In five out of seven subjects, the blood flow showed a tendency to be almost constant under the mechanical pressures which are 10.0 g mm-2 or higher. The effect of the duration of the pressure (10.0 g mm-2) exertion on the blood flow was also investigated and it was revealed that the blood flow tended to be constant after 60s in every subject. In the present study, it was also demonstrated that the temperature controlled thermoelectrical method is appropriate for studying the blood flow dynamics in oral mucosa.

Adult↗
PubMed1989

Antitumor effects of an antiangiogenic polysaccharide from an Arthrobacter species with or without a steroid.

A sulfated polysaccharide-peptidoglycan complex, DS-4152, isolated from the culture supernatant of an Arthrobacter species inhibited angiogenesis and tumor growth and enhanced the antiangiogenic activity of 11 steroid hormones by 2 to 100 times. In the presence of cortisone acetate or tetrahydro S, DS-4152 suppressed chick chorioallantoic membrane angiogenesis and murine tumor M5076 cell-induced s.c. angiogenesis. The antitumor effects of DS-4152 administered in combination with a steroid whose dose level did not affect tumor growth were examined. DS-4152 significantly inhibited the growth of s.c.-implanted B16 melanoma in combination with cortisone acetate. DS-4152 plus tetrahydro S inhibited the growth of s.c. solid tumors and prolonged the survival time of mice bearing highly metastasizing M5076. The body weight increase was not affected by any administration. On the other hand, the survival of mice with ascitic M5076 tumors was not affected by the combination of DS-4152 plus tetrahydro S. The antiangiogenic activity of DS-4152 was more potent than that of heparin. Furthermore, DS-4152 is an angiogenesis inhibitor by itself, without steroid hormones. Successive s.c. treatment with heparin caused hemorrhagic death, but with DS-4152, suppressed tumor growth without reducing body weight.

Animals↗
PubMed1989

[Magnetic resonance imaging of diseased cervical and lumbar intervertebral discs].

Magnetic resonance images (MRI) of diseased cervical and lumbar intervertebral discs involving both intrinsic and extrinsic cord lesions were examined using either a 0.15 T resistive or a 0.5 T superconductive magnetic imaging system. High resolution images were obtained by means of a surface coil in most cases. The vertebrae, intervertebral discs, and spinal cord were delineated in greatest detail on spin-echo (SE) images with a long repetition time (TR) and a short echo time (proton density-weighted image), on which the spinal cord was appreciated without overshadowing by the cerebrospinal fluid-filled subarachnoid space. Protrusion of degenerated intervertebral discs into the spinal canal was clearly demonstrated not only on sagittal but also on parasagittal and transverse views. The location of protruded discs and compression of the spinal cord, caudal sac, and nerve roots were well visualized three-dimensionally. Pathological features of intervertebral discs were better appreciated on T2-weighted images with long TR and SE pulse sequences. Degeneration of intervertebral discs resulted in decreased signal intensity in cases involving lumbar disc lesions but not those involving cervical disc lesions. In a case of suspected myelomalacia, the intrinsic cord lesion resulting from traumatic disc protrusion appeared as focal low signal intensity on T1-weighted images and as somewhat high intensity on T2-weighted images. The inversion recovery sequence with median inversion time displayed an inferior image of low contrast and was judged uninformative in comparison to SE images. The authors' observations demonstrate that MRI is an essential diagnostic technique for spinal cord disorders.(ABSTRACT TRUNCATED AT 250 WORDS)

Cervical Vertebrae↗
PubMed1989

[Histochemical investigation on glycogen in the epithelium of mucosa under denture base].

Accumulation of glycogen in the epithelium of the oral mucosa was evaluated in relation to the existence of wound and inflammation of the oral mucosa histochemically and histopathologically. Antemolar rhombus (the anterior part of the intermolar palate) of adult Wistar rat was employed as experimental area. Experimental wound of palatal mucosa was made by excision of crestal one third of the palatine ruga. Inflammation of the connective tissue was artificially induced by the insertion of silk thread or silk thread immersed in 5% formalin in the connective tissue parallel to the crest line of palatine ruga. The experimental area was examined histochemically and histopathologically up to 72 hours after experimental operation. In excision wound the accumulation of glycogen was observed in prickle cell layer of the epithelium after 24 hours. Although the inflammatory reaction was observed more prominently in the thread inserted connective tissue, the accumulation of glycogen in the epithelium could not be detected. The findings of this study suggested that inflammation itself does not induce the accumulation of glycogen in the epithelium of the oral mucosa and the accumulation could be an indication of wound and/or its healing process of oral epithelium.

Animals↗
PubMed1988

The sulfated polysaccharide-peptidoglycan complex potently inhibits embryonic angiogenesis and tumor growth in the presence of cortisone acetate.

In combination with cortisone acteate, the sulfated polysaccharide (SP)-peptidoglycan (PG) complex produced by an Arthrobacter species was found to inhibit both embryonic angiogenesis of chick chorioallantoic membrane (CAM) and growth of solid Sarcoma 180 tumor in mice. Three fractions obtained from the SP-PG complex by gel filtration showed a great difference in the inhibitory effect on angiogenesis of the CAM, whereas in ex vivo study such a difference was reduced. Of the three fractions, SP-PG-L having the lowest molecular weight and peptidoglycan content exhibited the highest antiangiogenic and antitumor activities, even higher than those of heparin. Neither desulfation nor sulfation of the SP-PG complex greatly affected the antiangiogenic activity, and dextran sulfates and mannoglucan sulfates were lacking the activity. This suggested that glycosyl sequences of sulfated polysaccharides are more important for the activity, rather than content or intramolecular distribution of sulfate groups.

Allantois↗
PubMed1988

Magnetic resonance imaging of subarachnoid hemorrhage.

Magnetic resonance (MR) imaging of subarachnoid hemorrhage (SAH) due to a ruptured aneurysm has been evaluated in relation to CT findings on 30 patients. In the acute stage, particularly less than 24 hours after the bleeding episode (25 patients), SAH appeared of high intensity relative to the surrounding brain on a T-2 weighted SE image but isointense where the corresponding CT scan showed blood clot of attenuation value over 60 H. A T-2 weighted SE image was able to reveal subtle evidence of SAH not visible on the CT scan. The T-1 weighted IR image was not as sensitive. Blood clot (HU greater than 60) appeared isointense, but mild and moderate SAH (HU less than 60) was indistinguishable from normal CSF. MR imaging was also sensitive to subacute and chronic SAH (5 patients). Three out of four SAH appearing normal on CT showed high intensity on T-2 weighted images. Thirteen out of 24 aneurysms (54%) larger than 5 mm in diameter on angiography were detected on T-2 weighted images. Smaller aneurysms less than 4 mm were not visualized. MR imaging was able to indicate the ruptured one in cases of multiple aneurysms by showing hemorrhagic lesions more clearly than CT. We conclude that MR imaging is very helpful for diagnosing SAH, particularly when CT is normal, and in indicating aneurysm location as well as rupture site.

Acute Disease↗
PubMed1988

[Spinal melanotic schwannoma: report of a case].

A case of spinal dumbbell shaped melanotic schwannoma was reported. A 58-year-old housewife had a 3-months history of progressive gait disturbance. She also complained of mild backache and numbness in both legs. Her family history was not remarkable. When examined on admission, October 10, 1982, mild weakness of both legs with spasticity and sensory impairment below the level of T10 dermatome without sacral sparing were evident. Her deep tendon reflexes were hyperactive on both sides and plantar responses were extensor bilaterally. Sphincteric disturbance was not significant. The function of her cranial nerves was intact. She had neither cutaneous lesions, abdominal mass nor organomegaly. Thoracic plain X-rays revealed erosion of the right side vertebral body and pedicle of the 10th thoracic vertebra. Myelography disclosed a complete block at the same level by an epidural mass. On CT-myelogram, soft tissue density mass compressing the thoracic cord was apparent in the right epidural space of the spinal canal which extended to the paravertebral region through the right intervertebral foramen. Partial destruction of the body and the right side pedicle was easily recognized. Laminectomy from T9 to T11 exposed a large extradural mass which was encapsulated, elastic soft and pigmented in nature. The tumor was dumbbell shaped and extended to the right paravertebral region through the intervertebral foramen. Costotransversectomy was performed to excise the mass entirely. Following the total removal of the tumor, internal fixation was carried out by means of Harrington instrumentation with methylmethacrylate.(ABSTRACT TRUNCATED AT 250 WORDS)

Female↗
PubMed1988

[Intracranial physiological calcification on computed tomography (Part 1): Calcification of the pineal region].

Of intracranial physiological calcification, common calcification of pineal region, choroid plexus of lateral ventricles and of basal ganglia was examined based on the frequency of occurrence of age and sex and type of CT scanners. Consecutive cases of 2877 (1450 males and 1427 females) underwent plain CT scanning were studied. Pathological calcification was excluded from this study. Three types of CT scanners (SCN-200, Somatom 2 and TCT-10 A) were used. As a whole, calcification was shown in 67.7% in pineal region, 57.6% in choroid plexus of lateral ventricles and 7.5% in basal ganglia. First, we reported in detail the calcification of pineal region, in which calcification occurred most frequently. Calcification in pineal region had a close relation with age by increasing with aging. The youngest patient was 8 years old. There was a striking increase in number of patients aged from 10 to 39 years. There was a gradual increase in those aged over 40 years. Of patients aged from 70 to 79 years, calcification was found in 81.5%. The incidence was noted no changes in patients aged over 80 years. As for patients aged over 20 years, calcification was observed in 75.1% (82.6% males and 68.0% females). In patients aged from 20 to 79 years, the calcification was significantly higher in male than female. Although there was a different incidence of calcification examined by three types of CT scanners, it was not significant. There was no significant difference between thickness of 8 mm section and 10 mm.

Adolescent↗
PubMed1988

[MRI findings of cervical cord injury. A case report of long-term follow-up].

A 63 year-old male, who sustained anterior cervical cord injury in a fall on his back during skiing, was consecutively examined by MRI from acute, up to the chronic stage. Right after the fall (2.5 hours later) the injured cord showed high intensity in T2 weighted images. This high intensity area stayed the same up to the chronic stage (6 months later). T1 weighted SE images showed no parenchymal change in the acute stage, but 3 months later a low intensity area appeared in the damaged cord. Thereafter, the injured cord exhibited localized low intensity on T1 weighted images, and high intensity on T2 weighted images, at subsequent MRI examinations. During the course of the examinations no significant neurological recovery was observed. Referring to the findings of our experimental cord injury studies, the high intensity in the T2 weighted images of the acute stage represents hemorrhagic necrotic tissue with edema, while those of the chronic stage suggest myelomalacia, and surrounding gliotic tissue. The low intensity in the T1 weighted images of the chronic stage reflects also this myelomalacia itself. We conclude that MRI of cervical cord injury is a useful diagnostic tool, not only delineating the level of the cord injury, but also aiding in the prognosis.

Follow-Up Studies↗
PubMed1988

[Intracranial physiological calcification on computed tomography (Part 2): Calcification in the choroid plexus of the lateral ventricles].

In this paper, we describe calcification in the choroid plexus of lateral ventricles with a discussion of the frequency of occurrence in categories of age, sex, and laterality, and its correlation with pineal calcification. The study was conducted on 2877 consecutive cases (1450 males and 1427 females) that had plain CT scanning. Three types of CT scanners (SCN-200, Somatom 2 and TCT-10 A) were used. This series included only calcification of the choroid plexus in the trigone of the lateral ventricles (glomus). Calcification was found in none of the cases aged under 9 years, 5.9% aged from 10 to 14 years and 17.4% aged from 15 to 19 years. The calcification rate strikingly increased with increasing age of the cases. It was 51.5% of cases between 30 and 39 years of age. After that, the increasing rate of calcification gradually decreased, however calcification was found in 74.4% of cases aged over 80 years. The calcification rate was 64.7% in our total series of cases aged over 20 years, 66.5% aged over 30 years and 70.7% aged over 50 years. The calcification rate of male cases was greater than that of females in the age group of over 15 years. However, there was a significant difference only in the cases ranging from 60 to 79 years of age. The initial incidence of male cases was found at the age of 12 years and that of females at the age of 16 years. There was no difference in calcification on right and left sides.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1988

[A case report of simultaneous multiple intracerebral hematomas].

A case of multiple spontaneous intracerebral hematomas is presented. A 67-year-old man with 7 years history of hypertension had sudden clumsiness in his right hand and an hour later dysarthria appeared. A CT scan taken 3 hours after the onset revealed two well demarcated high density areas in the left putamen and in the parietal subcortex. A diagnosis of multiple intracerebral hematomas was made. On neurological examination he was midly stuporous (13 points of Glasgow Coma Scale). Dysarthria, right hemiparesis and right extensor plantar response were seen. CT scan of 6 hours later disclosed the same findings as the previous study. He recovered well and neurologically free in a few days. On the following CT scans both hematomas were isodense 2 weeks later, and ring-like enhancement effect was noted. CT scan showed normal appearance 7 weeks later. On MRI using 0.5 T unit t-1 and t-2 weighted spin echo images of these hematomas also showed the similar chronological changes. The history, these CT and MRI studies suggest that two hematomas of this case occurred almost simultaneously in one cerebral hemisphere. No causative factors such as blood dyscrasias, AVM, angioma, septicemia, malignancies or sinus thrombosis was identified. We consider that a hypertensive intracerebral hematoma of the putamen was followed by the parietal intracerebral hematoma within a few hours, although amyloid angiopathy was not completely excluded because no cerebral biopsy of the lesion was performed.

Aged↗
PubMed1987

Magnetic resonance imaging of acute spinal cord injury. Report of three cases.

Magnetic resonance imaging of acute spinal cord injury is described. The traumatized cord segment was clearly shown as a hyperintensity in a T2-weighted image whereas it appeared as an isointensity in a moderately T1-weighted image. This different sensitivity may result from parenchymal hemorrhagic tissue and edematous changes due to direct trauma. Hyperintense tissue was also seen in the retro-pharyngeal and -tracheal spaces.

Accidents, Home↗
PubMed1987

[EC-IC bypass surgery using a long vein graft--reconstructive procedures for the occluded long vein grafts].

EC-IC bypass using a long vein graft has an advantage creating a large amount of blood flow immediately after the anastomosis, but on the other hand, disadvantage of relatively frequent incidence of the vein graft occlusion. In this report, we present three kinds of reconstructive operative procedures for the stenotic or occluded long vein grafts. Type A: A long vein graft bypass between external carotid and posterior cerebral artery was found occluded intraoperatively by the thrombosis occurred where the vein graft was injured during harvesting. Reconstruction was made simply by resecting the occluded segment of the graft and end-to-end suturing. Type B: A long vein graft used in subclavian artery-middle cerebral artery bypass was occluded three days postoperatively at the supraclavicular fossa by bleeding from the anastomosis site. The vein graft was found compressed and thrombosed. We reconstructed the occluded bypass by resecting the occluded supraclavicular segment and interposing a short vein graft with end-to-end anastomosis. Then, thrombectomy of the remaining vein graft was followed. Type C: A long vein graft used in external carotid-middle cerebral artery bypass stenosed at the anastomosis site with the external carotid artery a day after the operation. The stenotic bypass was successfully reconstructed by bridging a new short vein graft from another portion of the external carotid artery on the long vein graft distal to the stenotic site. All the long vein grafts we have done reconstructive surgery have been working well one to four years follow-up periods. So, we conclude that whenever a long vein graft occludes it should be reconstructed promptly before the vein graft becomes necrotic.

Adult↗
PubMed1987

[Aplasia of the posterior arch of the atlas--report on two cases].

Two cases of aplasia of the posterior arch of the atlas incidentally found are reported. Case 1: A 37-year-old man hit the forehead and the right mandible against the front glass at a head-on collision of his car and was brought to the emergency room. He was alert and neurologically normal except for multiple incision wounds with glass fragments in the face. CT, and cervical X-rays revealed total absence of the posterior arch of the atlas. Case 2: A 73-year-old woman, who sustained whip lash injury at an automobile accident, was admitted several hours after injury, complaining of neck and occipital pain. No neurological deficit was seen. CT demonstrated hemi-aplasia of the posterior arch of the atlas and isolated rudimentary posterior tubercle. Review of the literature and discussions were made on the incidence and genesis of this anomaly.

Adult↗