Search PubMed⌕ Search

Biomedical subjects

S Tamai

Publications and source records attributed to S Tamai.

At least 253 records · Page 14Linked to original sources
PubMed1992

Vascularized fibular graft for reconstruction after resection of aggressive benign and malignant bone tumors.

From 1982 to 1991, 19 patients at Nara Medical University, Kashihara, Japan, underwent resection of aggressive benign and malignant bone tumors, with limb salvage and reconstruction by free vascularized fibula grafts. The patients were followed up for an average of 54 months. The reconstructed site was the jaw in 6 cases, upper extremity in 3, spine in 1, pelvis in 2, and lower extremity in 7. Six patients had aggressive benign lesions, and 13 had malignant lesions. The sizes of the resultant bone defect ranged from 6 to 20 cm, and the lengths of fibular used ranged from 8 to 24 cm. The average time to union was 4.1 months (2-9 months) in the extremities and pelvis. Local recurrence was observed in 3 cases, for whom vascularized fibula grafts were performed for recurrent tumors. In cases of primary untreated tumors, no recurrences occurred. Therefore, this procedure should be performed at the time of primary operation after extensive resection of an aggressive benign or malignant bone tumor.

Adolescent↗
PubMed1992

Biochemical and histological sequences of membranous ossification in ectopic site.

Porous hydroxyapatite ceramics alone (control) and ceramics combined with rat marrow cells were implanted subcutaneously in the back of syngeneic rats and harvested 1-8 weeks after implantation. The ceramics were examined biochemically and histologically. Alkaline phosphatase activity in the marrow cell/ceramic composites began to increase at 2 weeks and achieved a peak at 4 weeks, followed by a gradual decrease. Bone gla protein contents in the composites began to increase at 3 weeks and steadily increased as time passed. Histologically, osteoblastic cells were detected at 2 weeks and obvious de novo bone together with active osteoblasts began to appear at 3 weeks in the composites. The process was membranous ossification without cartilage formation and was observed in the pores of the composites. The pore areas occupied by bone increased as time passed. In contrast, ceramics alone did not show any bone formation and contained traces of these biochemical parameters. These results indicated that the biochemical sequences correlate with the histological sequences in the heterotopic membranous ossification.

Alkaline Phosphatase↗
PubMed1992

The association of hypopituitarism with small pituitary, invisible pituitary stalk, type 1 Arnold-Chiari malformation, and syringomyelia in seven patients born in breech position: a further proof of birth injury theory on the pathogenesis of "idiopathic hypopituitarism".

We report seven cases of hypopituitarism all having a history of breech delivery, asphyxia at birth, and syringomyelia. A small pituitary gland was found on MRI or CT in six cases, invisible pituitary stalk on MRI in five cases, and type 1 Arnold-Chiari malformation in six cases. A constellation of these abnormalities are best explained by traction of brain and spinal cord of the subjects exerted during breech delivery and further support the primary role of birth trauma in the genesis of "idiopathic hypopituitarism".

Adolescent↗
PubMed1992

Surgical reconstruction of an ascending aortic dissection in Takayasu's arteritis.

A 45-year-old Japanese woman with Stanford type A dissecting aortic aneurysm underwent a reconstructive operation on the ascending aorta. Histopathological diagnosis was Takayasu's arteritis in the chronic and inactive phase. It is very rare that a dissecting aortic aneurysm results from Takayasu's arteritis. Long-standing hypertension and fragility of the aortic media due to disruption of elastic fibers were suspected to cause dissection in the entire aorta in this case.

Aortic Dissection↗
PubMed1992

Development of hepatocellular carcinoma associated with increases in DNA synthesis in the surrounding cirrhosis.

The relationship between DNA synthesis activity in hepatocytes from cirrhotic tissue and development of hepatocellular carcinoma was studied in 33 posthepatitic patients with Child's grade A cirrhosis. DNA synthesis activity was measured by a bromodeoxyuridine (a thymidine analogue) labeling index, using the bromodeoxyuridine-antibromodeoxyuridine in vitro method, and the patients were followed up prospectively with frequent liver ultrasonography for 2 years. During the 2-year follow-up, 11 of the 33 cirrhotic patients developed hepatocellular carcinoma; they included 8 of the 15 patients (53%) in the high labeling index (greater than 1.5%) group compared with only 3 of the 18 patients (17%) in the low labeling index (less than 1.5) group (P less than 0.05). Five of the latter 18 subsequently had increased synthesis activity. Of these 20 patients who showed high synthesis activities either initially or subsequently, 10 (50%) developed hepatocellular carcinoma, in contrast to 1 of 13 (8%) with persistently low activities (P less than 0.05). Thus, hepatocellular carcinoma seems to develop or may become detectable when DNA synthesis in the background cirrhosis is increasing or remains high.

Adult↗
PubMed1992

The role of radiotherapy in the treatment of primary mediastinal seminoma.

Nine patients with primary mediastinal seminoma were treated with radiotherapy. All patients achieved complete response on chest radiography. None of the three patients treated with whole mediastinal irradiation relapsed. Four of the six patients with involved-field irradiation had marginal relapses, suggesting the efficacy of the whole mediastinal irradiation.

Adolescent↗
PubMed1992

An experimental study of the flow-through venous flap: investigation of the width and area of survival with one flow-through vein preserved.

A quantitative analysis was undertaken to investigate the width and area of survival of flow-through venous flaps in 20 ears of 10 rabbits. The 3.0- x 3.0-cm flap models, which included one flow-through vein, were prepared with additional circulation from the graft bed and surrounding tissue excluded, as far as possible. The flaps were divided as follows: Group A--composite grafts (n = 10), and Group B--flow-through venous flaps (n = 10). All flaps in Group A became necrotic and all those in Group B showed partial survival along the flow-through vein. The average survival width was 1.10 +/- 0.48 cm, and the survival rate was 44 +/- 19.3 percent. Microangiograms revealed patency of the flow-through vein in all flaps of Group B. Histologically, there tended to be progressively more fibrous tissue in the area further away from the flow-through vein. The model is useful to investigate the width and area of survival in flow-through venous flaps.

Angiography↗
PubMed1992

Flumazenil does not antagonize halothane, thiamylal or propofol anaesthesia in rats.

We have studied the effects of flumazenil on sleep time and EEG in rats anaesthetized with 1.5% halothane, propofol 20 mg kg-1, thiamylal 30 mg kg-1, or combinations of diazepam 5 mg kg-1 and anaesthetic agents. We also studied the effects of flumazenil 0.3, 3 and 30 mg kg-1 on behaviour and EEG. Flumazenil 0.3 and 3 mg kg-1 alone had no effect on behaviour or EEG, but flumazenil 30 mg kg-1 had depressive effects similar to those of diazepam on behaviour and EEG. Flumazenil 0.3, 3 and 30 mg kg-1 i.v., antagonized the effects of diazepam 10 mg kg-1 i.v. on behaviour and EEG. Flumazenil had no antagonistic effect on sleep time induced by anaesthetic agents, but flumazenil 30 mg kg-1 potentiated propofol-induced anaesthesia. Flumazenil did not affect anaesthesia-induced EEG changes. Diazepam 5 mg kg-1 potentiated anaesthesia. Flumazenil antagonism of diazepam potentiation varied with anaesthetic agent: flumazenil 0.3 mg kg-1 antagonized diazepam action in halothane anaesthesia, but 30 mg kg-1 was required in propofol anaesthesia; this large dose was insufficient in thiamylal anaesthesia.

Anesthesia, Inhalation↗
PubMed1992

Responses of plasma adrenocorticotropic hormone, cortisol, and cytokines during and after upper abdominal surgery.

There is currently accumulating evidence for bidirectional communication between the neuroendocrine and immune systems. Various cytokines have been suggested to be involved in the stimulation of stress hormone secretion during the times of infection and inflammation. To assess the possible involvement and pathophysiologic significance of cytokines in the mechanisms responsible for the perioperative stress response of the hypothalamo-pituitary-adrenal axis, we observed the changes of plasma adrenocorticotropic hormone and cortisol levels together with those of plasma endotoxin and cytokine levels. In patients undergoing pancreatoduodenectomy, perioperative stimulation of adrenocorticotropic hormone and cortisol secretion was accompanied by a significant elevation of plasma cytokine levels. Application of epidural block up to the upper thoracic levels failed to suppress this stress response effectively. In patients undergoing unilateral total hip replacement, the response of plasma hormone levels was smaller and briefer with no significant increase of plasma cytokine levels. Application of epidural block up to the lower thoracic levels suppressed this hormonal response almost completely. In patients undergoing pancreatoduodenectomy, a significant elevation of plasma endotoxin level was followed by a gradual but significant elevation of plasma tumor necrosis factor alpha and interleukin-6 levels. It seems likely that the stimulatory effects of these cytokines on the secretion of adrenocorticotropic hormone and cortisol might be involved in the development of the greater and more prolonged stress response of hypothalamo-pituitary-adrenal axis. Our present study suggests that not only neural input from the surgical wound but also stimulation of cytokine production were responsible for the development of the stress response of the hypothalamo-pituitary-adrenal axis during and after upper abdominal surgery.(ABSTRACT TRUNCATED AT 250 WORDS)

Adrenocorticotropic Hormone↗
PubMed1992

Proof of plasmatic imbibition in rat musculocutaneous grafts: enzymatic proof using peroxidase.

At present, the concept of plasmatic imbibition is generally accepted. That is, observation of weight change or pigmentation methods of the grafts were established to support it. In the present study, we investigated plasmatic imbibition in rat musculocutaneous grafts histologically using peroxidase, which is one of the reductases. Tissue pigmentation by peroxidase became an insoluble sediment that indicated the sites of peroxidase activity. The entire contact surface of the graft with the recipient bed was stained brown within a few minutes after the operation. At 30 minutes, the panniculus carnosus and dermis were stained dark brown diffusely, extending toward the epidermis. This condition continued until the sixth day at least. As a result, peroxidase that was dissolved with the exudate between the graft and recipient bed was imbibed into the musculocutaneous graft.

Absorption↗
PubMed1992

Relationship of H-ras-1, L-myc, and p53 polymorphisms with lung cancer risk and prognosis.

Proto-oncogenes (H-ras-1 and L-myc) and tumor-suppressor gene (p53) loci have been implicated in lung carcinogenesis. DNA restriction fragment length polymorphisms at these gene loci are being evaluated in a case-control study as markers predictive of risk for cancer or of prognosis when cancer is present. The cases and controls had a cigarette-smoking history of 40 or more pack years or other abnormalities in pulmonary function tests, their ages were closely matched (64 years for cases and 61 years for controls) and the ratio of Caucasians to African Americans was close to unity (cases, 0.95:1.00, controls, 1.00:0.88). The H-ras-1 gene contains an insertion deletion polymorphism. Inheritance of rare H-ras-1 alleles, defined by MspI digestion, confers a relative risk for lung cancer of 2.0 (95% confidence interval, 0.5-7.3) for Caucasians and 3.2 (0.9-11.6) for African Americans (74 cases, 67 controls). The L-myc gene sequence has a restriction site (EcoR1) polymorphism between the second and third exons. Inheritance of restriction site-present alleles was reported to confer poor prognosis (presence of lymph node metastases) in Japanese lung cancer patients. This hypothesis was tested in both case-control study subjects (56 cases, 55 controls) and additional surgical cases (40), but no evidence was found to support the hypothesis in the U.S. population. The p53 gene is a tumor-suppressor gene that can encode either a proline or an arginine in the 72nd residue. No associations was found between the minor allele (proline) and diagnosis of lung cancer (76 cases, 68 controls).(ABSTRACT TRUNCATED AT 250 WORDS)

Base Sequence↗
PubMed1992

A case of asymptomatic cortisol producing adrenal adenoma.

We describe a man without the clinical findings of Cushing's syndrome, but who harbored an incidentally found cortisol-producing adrenal adenoma. On adrenal 131I-adsterol imaging, there was good uptake to the nodule, but no visualization of the contralateral adrenal. No abnormalities were found in the basal plasma cortisol, ACTH, urinary free cortisol and 17OHCS. However, dynamic hormone assessment revealed the existence of abnormal cortisol secretion: no suppression to dexamethasone, incomplete response to human corticotropin-releasing hormone, and lack of diurnal variation in plasma cortisol. Left adrenalectomy was performed with the diagnosis of cortisol-producing adrenal tumor. The pathological finding was an adrenal adenoma, and the perifusion of the excised tissues revealed a negligible response of the tumor tissue to ACTH though the residual normal cortex responded. Postoperative course was uneventful without replacement therapy with cortisol. It is suggested that the tumor autonomously produced a small amount of cortisol not only insufficient to provide clinical Cushing's syndrome, but also to provide typical suppression of hypothalamo-pituitary corticotroph-adrenal system.

Adenoma↗
PubMed1992

Tear of an ossified rotator cuff of the shoulder. A case report.

A 57-year-old man with an ossified rotator cuff with acute tears was treated by resecting the ruptured part, as well as the ossicles, and by repairing the massive cuff defect with Teflon felt. Six years after surgery, the pain had been completely relieved, and shoulder motion and muscle strength had been recovered.

Humans↗
PubMed1992

Crystalloids in angiomyolipoma. 1. A previously unnoticed phenomenon of renal angiomyolipoma occurring at a high frequency.

We present a description of unique crystalloids in renal angiomyolipoma that have not previously been reported. The crystalloids cannot be identified by hematoxylin-and-eosin staining. Detailed observation after diastase treatment followed by PAS staining revealed needle- and rod-like crystalloids, which were clearly seen even by light microscopy, in 11 of 17 patients. Their appearance was characterized by the following phenomena: (a) They appeared mainly in large epithelioid smooth-muscle cells; (b) they appeared at a relatively high frequency at sites where smooth-muscle cells showed diffuse proliferation and where a hemangiopericytic pattern was observed; (c) they were often detected easily even at a site with a sarcomatous appearance; and (d) PAS-positive, diastase-resistant granules were often observed by light microscopy in the vicinity of crystalloids in all 17 patients. Electron-microscopic observation of one patient also revealed characteristic crystalloids. Prior to our study, only one patient had been reported to show crystalloids by electron microscopy, and the crystalloids were interpreted as renin. However, our study used Bowie's staining and immunohistochemistry to prove they were not renin. The nature of the crystalloids still needs to be elucidated. The fact that they closely resemble structures seen in alveolar soft part sarcoma provides one clue to their identification.

Adult↗
PubMed1992

A study on elongation and knot slacking of various sutures.

The tension holding capacity of suture materials was measured by in vitro and in vivo experiments. Silk and expanded polytetrafluoroethylene sutures showed large elongation and significant knot slacking after tight tying. Although ultrahigh molecular-weight polyethylene suture had excellent creep resistance, it showed a relatively low tension holding capacity because of substantial knot slacking. On the other hand, polyester and high-strength poly(vinyl alcohol) sutures showed an excellent in vivo tension holding capacity, along with low elongation and insignificant knot slacking. Clinical performance of these sutures was briefly discussed from the mechanical point of view.

Elasticity↗
PubMed1992

[Assessment of limp in patients with coxarthrosis--three-dimensional measurement of the pelvic rotation].

To assess the gait characteristics of the patients with coxarthrosis objectively, the rotation of the pelvis during ambulation was measured on the frontal, sagittal and horizontal planes using 3 gas-rate-sensors(Rotational Angle Measurement System G-2210, Anima Inc., Tokyo). In the normal subjects, the waveforms of the rotational angle on the frontal plane were symmetrical, highly reproducible and had 2 peaks. In contrast, the waveforms of the patients were asymmetrical and poorly reproducible. This was shown objectively using Fourier transform technique. The mean rotational angle of the patients was smaller than that of the normal subjects on the frontal plane, and larger on the sagittal plane. We can distinguish the patients from the normal subjects by observation of the waveform on the frontal plane and the ratio of the rotational angle on the sagittal plane to that on the frontal plane.

Adult↗
PubMed1992

[Establishment and characterization of an ascites-forming rat osteosarcoma cell line].

A transplantable ascites-forming osteosarcoma (J. H. 1-AOS) derived from the 35th generation of spontaneous osteosarcoma, J. H. 1-OS, grown in Fischer 344 syngeneic rats was established. Tumorigenicity, histochemical and ultrastructural characteristics were investigated. Rats carrying the ascites form osteosarcoma died of cachexia about 15 days after transplantation, 1.5-2.5 x 10(6) cells/ml of tumor cells generally being involved in the ascites and tumor nodules formed in the mesentery. After inoculation into the back subcutaneous space, tumor growth was very rapid. Small round cells were detected in the Giemsa stain smear, and although osteoid formation was histologically lacking, cell surface alkaline phosphatase activity was noted both light and electron microscopically. Polyacrylamide gel electrophoresis demonstrated that alkaline phosphatase (Al-p) extracted from this tumor was consistent with Al-p from rat fetal calvaria. Thus maintenance of osteogenic potential is suggested for these ascites osteosarcoma cells, indicating their usefulness for further studies of biological behaviors of this tumor type.

Alkaline Phosphatase↗