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Biomedical subjects

S Tamai

Publications and source records attributed to S Tamai.

At least 109 records · Page 6Linked to original sources
PubMed1998

Results of opening-wedge osteotomy for the treatment of a post-traumatic varus deformity of the ankle.

We performed a one-stage opening-wedge valgus osteotomy in nine patients to correct a post-traumatic progressive varus deformity of the ankle. The osteotomy site was stabilized with two, three, or four Kirschner wires or with a plate and screws (in one patient). The site of the osteotomy united within two months after the operation in eight patients and at six months in one patient who was fifty-nine years old. The average duration of follow-up was seven years and four months (range, two years and four months to thirteen years and two months). Postoperatively, the range of motion of the ankle was decreased in six patients and remained unchanged in three. However, none of the patients reported any limitation in the activities of daily living, and the four adolescent patients were able to participate in sports activities. The result was graded as excellent for four ankles, good for two, and fair for three.

Activities of Daily Living↗
PubMed1998

Human marrow cells-derived cultured bone in porous ceramics.

From four patients (mean age, 60 years; range 51-76 years), 3 ml of bone marrow was collected from the ilium. The marrow was cultured to concentrate and expand the marrow mesenchymal cells on a culture dish. The cultured cells were then subcultured either on another culture dish or in porous areas of hydroxyapatite ceramics in the presence of dexamethasone and beta-glycerophosphate (osteogenic medium). The subcultured tissues on the dishes were analyzed by scanning electron microscopy (SEM), and subcultured tissues in the ceramics were implanted intraperitoneally into athymic nude mice. Vigorous growth of spindle-shaped cells and a marked formation of bone matrix beneath the cell layers was observed on the subculture dishes by SEM. The intraperitoneally implanted ceramics with cultured tissues revealed thick layer of lamellar bone together with active osteoblasts lining in many pore areas of the ceramics after 2 months. The in vitro bone formation on the culture dishes and in vivo bone formation in porous ceramics were detected in all cases. These results indicate that we can assemble an in vitro bone/ceramic construct, and due to the porous framework of the ceramic, the construct has osteogenic potential similar to that of autologous cancellous bone. A significant benefit of this method is that the construct can be made with only a small amount of aspirated marrow cells from aged patients with little host morbidity.

Aged↗
PubMed1998

[A case of isoniazid-induced pneumonitis].

A 55-year-old man was given a diagnosis of pulmonary tuberculosis. He was treated with isoniazid (INH), rifampicin (RFP), ethmbutol (EB) and pyrazinamide (PZA). After three weeks of treatment, he developed fever, dyspnea and dry cough. A chest X-ray taken at that time showed new reticulo-nodular shadows bilaterally and right pleural effusion. Ga scintigram showed strong uptake in both lungs. Transbronchial lung biopsy revealed alveolitis, suggesting drug-induced pneumonitis. Drug lymphocyte stimulation tests for INH, RFP, EB and PZA were negative. Because his symptoms were severe, all drugs were discontinued and daily predonisolone (30 mg) therapy was started. The symptoms and bilateral reticulo-nodular shadows soon resolved. The antituberculosis drugs were changed to streptomycin and levofloxacin, but these were ineffective. Therefore, EB, RFP and PZA, which only rarely induce pneumonitis, were carefully restarted in that order. Pneumonitis did not recur and the pulmonary tuberculosis improved. This clinical course suggests INH-induced pneumonitis.

Antitubercular Agents↗
PubMed1998

[Telomerase activity in esophageal carcinoma and lesions unstained with Lugol's solution].

Telomerase is a specific enzyme required for the replication of telomeres. Its activity is detected in almost human cancers. We examined in esophageal carcinoma and lesions unstained with Lugol's solution telomerase activity by using telomeric repeat amplification protocol (TRAP) assay. Telomerase activity was detected in all 22 esophageal carcinomas, regardless of histopathological findings. In unstained lesions, telomerase activity was detected in 15 of 22; 10 squamous cell carcinomas, four dysplasia, one regenerative epithelium, no telomerase activity was found in seven; four normal esophageal epithelia, two Barrett's esophagi, one regenerative epithelium. These results suggest that telomerase activity may be a useful molecular marker for the diagnosis of esophageal carcinoma and of the early esophageal carcinoma in area unstained with Lugol's solution.

Carcinoma, Squamous Cell↗
PubMed1998

[Clinicopathological study of six cases of primary pulmonary lymphoma diagnosed by gene rearrangement analysis].

We report six cases of primary pulmonary lymphoma in which a gene-rearranged band was shown by Southern blot analysis of transbronchial or surgical biopsy specimens. The cases were 3 mens and 4 women with an average age of 59.6, who had abnormal pulmonary shadows on chest X-ray. Two cases had Sjögren's syndrome and one case had monoclonal gammopathy (IgM-lambda type). Histopathologic and immunologic examination revealed diffuse infiltration of small lymphocytes (B-cell type) in all cases, and histological features of lymphoepithelial lesion or lympho-cytic interstitial pneumonia (LIP) in three cases. CT revealed an ill-defined margin, air-space consolidation, and air-bronchogram in all cases. A CT-angiogram sign was apparent in 2 cases. In all cases, Southern blot analysis of the tissue obtained from transbronchial or surgical biopsy revealed a gene re-arranged band, supporting the diagnosis of primary pulmonary lymphoma. We infer that an ill-defined margin, air-bronchogram and air space consolidation on CT were associated with the histopathological features of primary pulmonary lymphoma.

Aged↗
PubMed1998

[Respiratory bronchiolitis-associated interstitial lung disease].

A 48-year-old man was admitted because of persistent dry cough for six months. He had been a smoker for 25 years, averaging a pack a day, and demonstrated clubbing of the fingers. Basilar fine crackles were observed in both lung fields. Chest X-ray films on admission showed diffuse reticulonodular shadows. Chest computed tomograms showed low-attenuation areas mainly in the center of the upper lung field, and ground-glass opacity, air bronchiolograms, and perivascular interstitial thickening of the peripheral vessels mostly in the lower field. A Gascintigram disclosed mild accumulation in both lungs. A transbronchial lung biopsy specimen did not reveal special features. However, a biopsy specimen obtained by thoracoscopy showed evidence of respiratory bronchiolitis, with a mononuclear inflammatory process involving respiratory bronchioles and adjacent air space, associated with mild fibrous thickening of the peribronchiolar interstitium and surrounding alveoli septa. These findings suggested that the patient had respiratory bronchiolitis-associated interstitial lung disease, the second case to be reported in Japan.

Bronchiolitis↗
PubMed1997

Histologic and mechanical evaluation for bone bonding of polymer surfaces grafted with a phosphate-containing polymer.

A phosphate-containing polymer was covalently immobilized onto a polyethylene (PE) rod, a poly(ethylene terephthalate) (PET) thread, and a PET film by a surface graft polymerization technique, followed by immersion in calcium phosphate solution to deposit a thin hydroxyapatite (HA) layer on the modified polymer surfaces. The PE rod had a tapered shape, while the PET thread was fixed with clips after implantation, both to minimize the micromovement which may occur in bone. The PE rod was implanted through press-fitting in the femur of rat. Significant enhancement was observed for direct contact of the implant surface with a newly formed bone for both the grafted only and the further HA-deposited PE rods in comparison with the untreated PE at 4, 5, and 6 weeks after implantation. The rats implanted with the modified PET thread in the femur were sacrificed 3 and 6 weeks after implantation. Statistically significant differences were observed for the untreated versus the grafted plus HA-deposited rods at 6 weeks after implantation. To study the resorption of the deposited HA on the methacryloyloxyethylene phosphate-grafted surface, HA-deposited PET films were subcutaneously implanted in the back of rats. The deposited HA was rapidly resorbed within 3 weeks of implantation. These results suggest that the phosphate polymer chains grafted on the PE and PET surfaces effectively induced nucleation and growth of HA crystals. It seems likely that the thin HA layer additionally deposited in vitro onto the grafted PE and PET surfaces was resorbed rapidly and then promoted the growth of HA crystals in vivo.

Animals↗
PubMed1997

Chromosome assignment of aberrant NotI restriction DNA fragments in primary hepatocellular carcinoma.

DNA aberrations in human hepatocellular carcinoma (HCC) were studied by two-dimensional DNA electrophoresis analysis. Five intensified and 60 dwindling spots were detected recurrently in the two-dimensional profile which showed about 3000 restriction DNA fragments as distinctive spots. We assigned these aberrant spots to chromosomes, using the chromosome-assigned two-dimensional profile. Four of the five intensified, and 53 of the 60 dwindling spots were given chromosome assignments. Intensified spots were assigned to chromosomes 5, 6, 9 through 12, 16 and 18. Among the dwindling spots, the highest incidence of aberrations was found on chromosome 16, followed by 9 through 12 and chromosome 2. No aberrations were detected in chromosomes 7, 21, 22 or Y.

Carcinoma, Hepatocellular↗
PubMed1997

Increased telomerase activity is not directly related to metastatic potential in rat transplantable osteosarcomas.

Previously, we reported the establishment of two transplantable osteosarcomas in rats, one induced by local application of a carcinogen, 4-hydroxyamino quinoline 1-oxide (4-HAQO), and another which developed spontaneously, and their subdivision into four lines with high and low metastatic potential to the lung. In the present study, activation of telomerase was investigated by the telomeric repeat amplification protocol (TRAP) assay followed by densitometric quantification. Telomerase activity was found to be elevated in all four lines without any link to the metastatic potential. Thus the spontaneous osteosarcoma (SOS) and derived metastatic lesions (S-SLM) demonstrated a 20.1-23.5-fold increase and the chemical carcinogen (4HAQO)-induced osteosarcoma (COS) and metastatic lesions (C-SLM) were 18.4-19.1-fold elevated as compared to the value for abdominal muscle. The results suggest that activation of telomerase occurs in rat osteosarcomas but that it is not directly involved in determining their metastatic potential.

Animals↗
PubMed1997

Relationship between the recurrence of hepatocellular carcinoma (HCC) and serum alanine aminotransferase levels in hepatectomized patients with hepatitis C virus-associated cirrhosis and HCC.

BACKGROUND: The relationship between the recurrence of hepatocellular carcinoma (HCC) and the serum alanine aminotransferase (ALT) level was studied in hepatectomized patients with hepatitis C virus (HCV)-associated cirrhosis and HCC. METHODS: Twenty-six hepatectomized patients with HCV-associated cirrhosis and HCC whose resected specimens showed neither portal vein nor hepatic vein invasion by HCC histologically were divided into 2 groups: 15 patients who had no recurrence 3 years after surgery (Group A) and 11 patients whose disease recurred 1-3 years after surgery (Group B). The patients' serum ALT levels during this period were examined. RESULTS: In Group A, serum ALT generally showed sustained low levels < 80 international units (INU) in 12 patients (80%). In contrast, ALT levels in Group B showed several peaks or plateaus > 80 INU in all patients except 2. The recurrence rate of HCC in the hepatectomized patients with sustained low levels of ALT was 14.3% (2 of 14 patients) at 3 years, and was significantly lower (P < 0.01) than that in those patients whose ALT levels showed several peaks or plateaus > 80 INU (9 of 12 patients; 75.0%). The average level of mode of ALT in Group A (48.8 +/- 26.0 INU) was significantly smaller than that in Group B (101.1 +/- 47.3 INU) (P < 0.005). CONCLUSIONS: The importance of hepatocytic necrosis in the recurrence of HCC in hepatectomized patients with cirrhosis and HCC of HCV origin was demonstrated and the significance of subsiding hepatic necroinflammatory process in the prevention of HCC recurrence suggested.

Aged↗
PubMed1997

p53 mutation and absence of mdm2 amplification and Ki-ras mutation in 4-hydroxyamino quinoline 1-oxide induced transplantable osteosarcomas in rats.

Previously, we reported the establishment of two transplantable osteosarcomas, one induced by local application of a carcinogen, 4-hydroxyamino quinoline 1-oxide(4-HAQO), and another which developed spontaneously in rats, and their subdivision into four lines with high and low metastatic potential to the lung. In the present study, mutations of p53 and Ki-ras genes were investigated by PCR and SSCP followed by direct sequencing, and the amplification of the mdm2 gene was assessed by Southern blot analysis. Mutations of p53 in exon 7 were detected in 4-HAQO-induced transplantable osteosarcomas, but not their spontaneous counterparts, irrespective of the metastatic potentials. Direct sequencing revealed a CGC to CAC transition with an amino acid change of Arg to His, at codon 246. Neither Ki-ras mutations nor mdm2 amplification were detected in any of the transplantable tumors. The results suggest that while p53 mutations occurred during osteosarcoma development by 4-HAQO without mdm2 amplification and Ki-ras mutation does not contribute to osteosarcoma development in rats.

4-Hydroxyaminoquinoline-1-oxide↗
PubMed1997

Osteoblastic phenotype expression on the surface of hydroxyapatite ceramics.

To analyze the bone-bonding property of hydroxyapatite ceramics (HA), composites of rat marrow cells and porous HA were implanted subcutaneously and harvested at 3 to 4 weeks postimplantation. De novo bone formation was observed primarily on the HA surface without fibrous tissue interposition. The HA/tissue interface was analyzed by the observations of thin undecalcified histological sections and fractured surfaces of the implants. The observations were done with a light microscope and a scanning electron microscope (SEM) connected to an energy dispersive spectrometer. The interfacial analyses showed the appearance of osteoblastic cells on the HA surface and that the cells had initiated partially mineralized bone (osteoid) formation directly onto the surface. The osteoid matured into fully mineralized bone, resulting in firm bone bonding to the HA surface. Characterization of osteoblastic cells on the surface was done by determining levels of protein and gene expression of bone Gla protein (BGP, a.k.a. Osteocalcin), i.e., immunohistochemistry and in situ hybridization, respectively. The existence of BGP and mRNA in the cytoplasmic area of the cells confirmed that active osteoblast apposition fabricated primary bone on the HA surface. All of these results indicate the importance of the HA surface in supporting osteoblastic differentiation of marrow stromal stem cells, which leads to firm bone bonding.

Animals↗
PubMed1997

Primary leiomyosarcoma of the thyroid gland.

Primary leiomyosarcoma of the thyroid gland is extremely rare, and to the best of our knowledge only five well-documented cases have been reported in the world literature. We herein report a 58-year-old female patient with primary leiomyosarcoma of the thyroid who was successfully treated by total thyroidectomy with a modified neck dissection. Immunohistochemically, the tumor cells showed positive reactivity to alpha-smooth muscle actin and vimentin. Radical surgery was thus considered to be essential in the treatment of this rare but rather aggressive malignancy.

Actins↗
PubMed1997

Pathologic significance of meningeal enhancement ("flare sign") of meningiomas on MRI.

BACKGROUND: The purpose of this study was to clarify the pathologic features and clinical significance of the meningeal enhancement surrounding meningiomas ("flare sign") on contrast-enhanced T1-weighted magnetic resonance images (MRI). METHODS: The marginal dura mater of tumors was resected from nine cases of meningioma exhibiting a flare sign and used for histopathologic evaluation. RESULTS: Connective tissue proliferation was found in the dura mater in all cases, vascular proliferation was found in three, and tumor cell nests were observed in four cases. In one case, tumor cells were found 4.5 mm from the edge of the tumor. In another case, a meningothelial cell cluster was found. CONCLUSIONS: These results suggest that tumor cell nests are present frequently in dura mater that exhibits the flare sign, and that the dura mater near these lesions should be resected as widely as possible.

Aged↗
PubMed1997

Arthroscopic meniscal repair using fibrin glue. Part I: Experimental study.

An experimental study of rabbit menisci was carried out to evaluate the healing-promoting properties of fibrin glue and fibrin glue-containing marrow cells. A full-thickness defect, 1.5 mm in diameter, was made within the avascular portion of the meniscus and left empty in 20 menisci (C group), filled with fibrin glue in 20 menisci (F group), and filled with fibrin glue-containing marrow cells in 20 menisci (M group). Measurements of the remaining defects and histological examinations were performed 1, 3, 6, and 12 weeks after each procedure. Overall, the remaining defects in the F group and, particularly, in the M group were significantly smaller than those in the C group at the various time points. Furthermore, the results of histological study showed earlier mature healing of the defects in the M group than of those in the F group. Our results suggest that fibrin glue, especially in a preparation containing marrow cells, may enhance meniscal healing.

Animals↗
PubMed1997

Arthroscopic meniscal repair using fibrin glue. Part II: Clinical applications.

Since 1984 we have arthroscopically repaired meniscal tears using a purified fibrin glue. This article describes clinical application of a fibrin-based glue to arthroscopic meniscal repair and a long-term follow-up study of 61 repaired menisci in 40 patients (average follow-up, 8 years; range, 5.1 to 11.4 years). Of these patients, 6 complained of recurrent meniscal symptoms and received partial meniscectomy. According to stepwise logistic regression analysis, the factors most strongly correlated with recurrent symptoms were insufficiency of the associated anterior cruciate ligament, repairs of fresh tears, and repairs requiring supplementary meniscal sutures (P < .05).

Adult↗
PubMed1997

Vascular compliance and vasoconstrictive reactions in rat hindlimbs: comparison between storage temperatures of -1 degree C and 4 degrees C.

The vascular compliance and contractility of vascular smooth muscle of rat freshly amputated hindlimbs and hindlimbs preserved at -1 degree C for 12, 24, 48, and 72 hr were evaluated using a fresh blood extracorporeal circulatory system. Vascular compliance was measured under physiologic circulatory conditions (blood pressure of the amputated limb was maintained at 80 to 150 mmHg). Vascular compliance after storage at -1 degree C for 12 hr or longer decreased significantly from that of freshly amputated limbs (p < 0.01). To evaluate the contractility of vascular smooth muscle, the arterial blood pressure in the amputated limbs was transiently increased with injections of norepinephrine. The contractility after storage at -1 degree C for up to 24 hr was not different from that of freshly amputated limbs. However, it decreased significantly after 48 hr or longer. A comparison of these results with an earlier study that used identical methods to investigate limbs preserved at 4 degrees C suggested that storage at -1 degree C was inferior to that at 4 degrees C with respect to vascular compliance, but was superior to storage at 4 degrees C with respect to smooth muscle contractility.

Amputation, Surgical↗