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Biomedical subjects

S Tamai

Publications and source records attributed to S Tamai.

At least 73 records · Page 4Linked to original sources
PubMed1999

Long-term results of arthrodesis for osteoarthritis of the ankle.

A bone graft in the shape of a triangular prism was taken from the anterior surface of the tibia and used in the arthrodesis in 43 joints of 42 patients with primary and secondary osteoarthritis of the ankle. The modified anterior sliding inlay graft method was used. The average period of external immobilization was 5.8 weeks (range, 27-84 days), and followup ranged from 2 years 4 months to 14 years 11 months (average, 7 years 2 months). Nonunion was detected in three (7%) patients: one patient returned to work without additional treatment, and the other two patients underwent followup surgery within 7 months, and bony union was achieved. The final rate of nonunion was 2.3%. After the operation, excellent alleviation of pain was obtained. However, dorsiflexion of the foot decreased from the preoperative average value of 10.5 degrees to the postoperative value of 4.2 degrees, and plantar flexion also decreased from the preoperative value of 24.7 degrees to the postoperative value of 14 degrees. In addition, the range of motion of the subtalar and Chopart joints gradually improved with little effect on daily living activities. The most appropriate position of arthrodesis of the ankle appears to be in the neutral position between dorsal and plantar flexion. In addition, the varus and valgus angle of the hindfoot should be in a neutral or slightly valgus position. Degenerative arthritis developed and advanced in the subtalar joint in 32.5% of the patients, and these degenerative changes were exacerbated in many patients if such changes were present before surgery. Tibial stress fracture occurred in two (4.7%) patients as a complication that was specific to the current surgical method. Thus, the surgical procedure was modified to prevent the onset of tibial stress fracture.

Activities of Daily Living↗
PubMed1999

Thin cement mantle and osteolysis with a precoated stem.

The radiographic and clinical results of 55 hips (52 patients) implanted with the Harris precoat hip prosthesis using second generation cementing technique were investigated in this study. All metal backed sockets were fixed with cement. The preoperative diagnoses were osteoarthritis secondary to dysplastic hips in 42 patients, primary osteoarthritis in six, rapidly destructive coxarthrosis in five, and osteonecrosis of the femoral head in two. The average age of patients at the time of surgery was 67 years. The average duration of followup was 8 years. The rates of aseptic loosening and osteolysis in the femoral side were 5.5% (three hips) and 12.7% (seven hips), respectively. Three sockets were loosened, and no osteolysis was detected in the acetabular side. The mantle of cement in the femur was graded using the criteria described by Mulroy et al. Twenty-seven of 55 (49%) hips had regions with a thin cement mantle less than 1 mm in thickness or a defect in the cement mantle. Osteolysis was detected in seven of the 27 (26%) hips. Locations of osteolysis were coincidental with those of thin cement mantle or defect with the exception of one hip. This study clearly shows that a thin cement mantle less than 1 mm in thickness and a defect in the cement mantle lead to osteolysis.

Acetabulum↗
PubMed1999

The role of serum imbibition for skin grafts.

Numerous studies of grafted skin suggest that full-thickness skin grafts are nourished by exudate from the recipient bed called a serum imbibition. However, whether serum imbibition by itself is sufficient for nourishment of skin grafts has not been shown definitely and directly. To clarify the role of serum imbibition, we performed a comparative study between 20 skin grafts and 20 musculocutaneous flaps. The nourishment of the cell in the skin graft is by serum imbibition. That in musculocutaneous flaps is mainly derived from blood supply. We evaluated the nourishment by means of the unique characteristics of the cell cycle. Once cells are put into a synthetic phase, they cannot reverse or stop the progress of the cell cycle. To take advantage of this characteristic of the cell cycle, prewounding methods (40 flaps were lifted once and put back to the original sites prior to the evaluation) were intended for the cells in pre-elevated skin to turn into a proliferating phase. Cells were examined by antibody against proliferating cell nuclear antigen immunohistologically, to determine whether they had turned into the proliferating phase or not. After 3 days, all flaps were reelevated; half (20 flaps) had their muscle layer and the neurovascular bundle removed to make a full-thickness skin graft. The rest (20 flaps) were only lifted. They were sutured back to the original sites. Ten skin grafts and musculocutaneous flaps each were harvested at 3 hours (1st day) and at 11 days (11th day) after the second operation. Bromodeoxyuridine, which is a thymidine analog and is taken into the cells in the synthetic phase, was introduced intraperitoneally 2 hours before the harvest. All flaps and grafts were evaluated histologically and immunohistologically. Proliferating cell nuclear antigen analysis showed that the prewounding method induced the cells of skin grafts and musculocutaneous flaps to proliferate before the implantation. Regarding the bromodeoxyuridine uptake, no significant differences could be seen between skin grafts and musculocutaneous flaps irrespective of their different nourishment. No structural changes, such as degenerative or necrotic, could be seen at the hair follicle and other glands even at the 11th day. Almost all of the layers of skin grafts survived as long as they were checked by light microscopy (hematoxylin and eosin stain). No differences could be seen between musculocutaneous flaps and skin grafts or between the 1st and 11th days in this study. We concluded that serum imbibition is sufficient for nourishment of skin grafts, just as blood supply is sufficient for nourishment of musculocutaneous flaps.

Animals↗
PubMed1999

Inhibition of spontaneous rat osteosarcoma lung metastasis by 3S-[4-(N-hydroxyamino)-2R-isobutylsuccinyl]amino-1-methoxy-3,4-dihydroc arbostyril, a novel matrix metalloproteinase inhibitor.

In the present experiment, we examined the effects of OPB-3206, 3S-[4-(N-hydroxyamino)-2R-isobutylsuccinyl]amino-1-methoxy-3,4- dihydrocarbostyril, a novel metalloproteinase inhibitor, on the growth and metastasis of transplantable osteosarcomas (spontaneous osteosarcoma, selected lung metastatic lesions; S-SLM), which were previously established in rats. OPB-3206 inhibited the activities of interstitial collagenase, gelatinases A and B, and stromelysin in vitro. After oral administration to rats, its serum concentration peaked at 40 min and the drug was no longer detectable at 8 h. When OPB-3206 was orally administered at 0%, 0.1% and 0.4% in the diet for 4 weeks, starting 7 days after subcutaneous transplantation of osteosarcomas to male Fischer 344 rats, numbers of lung metastatic nodules were significantly reduced by the highest dose, while the growth of subcutaneous tumors was not affected. Zymographic analysis showed the presence of pro matrix metalloproteinase (proMMP)-2, proMMP-9 and MMP-9 activities in S-SLM. In animals fed 0.4% OPB-3206, the activity of proMMP-9 was increased, but that for MMP-9 had become undetectable. The results thus suggest that OPB-3206 selectively inhibits lung metastasis of rat transplantable osteosarcomas by inhibiting MMP-9 activation.

Administration, Oral↗
PubMed1999

Osteogenic phenotype expression of allogeneic rat marrow cells in porous hydroxyapatite ceramics.

Porous hydroxyapatite (HA) ceramics were combined with either allogeneic (ACI) or isogeneic (Fischer 344) rat marrow cells and implanted in subcutaneous sites of Fischer rats. FK506 as an immunosuppressant or saline was administered to the recipient rats. The implanted marrow/HA composites were harvested on day 28 and analyzed for bone-forming capability by determining osteoblastic phenotype expression levels of protein synthesis and gene expression. The alkaline phosphatase (ALP) activity and osteocalcin (OC) contents were very low and mRNAs (Northern blot analysis) were not detected in the allografts without FK506. However, high activity of ALP and high content of OC were found and mRNAs were detected in the allografts with FK506 and in the isografts (with and without FK506). This analysis indicates the osteogenic potential of allogeneic marrow cells in the presence of FK506. The histologic sections revealed that allografts without FK506 did not show bone formation but did show the infiltration of many small cells in the ceramics indicating an immunologic reaction, however, the allografts with FK506 and the isografts (with and without FK506) showed consistent de novo bone formation on the HA pore surface. These results indicate that FK506 can suppress the immunologic reaction in the allografts and induce a favorable conditions to support osteoblastic differentiation of allogeneic rat marrow stromal stem cells on the surface of HA ceramics. Therefore, our study suggests the feasibility of clinical transplantation of allogeneic bone marrow for a selected bone graft in applications using adjuvant systemic immunosuppression.

Alkaline Phosphatase↗
PubMed1999

Arthroscopic drilling for the treatment of osteochondral lesions of the talus.

BACKGROUND: An osteochondral lesion of the talus is a relatively rare disorder of the ankle. While a number of treatment options have been reported, it appears to be difficult to manage all lesions with a single approach. We evaluated the indications for and the results of arthroscopic drilling for the treatment of an osteochondral lesion of the talus. METHODS: Eighteen ankles (seventeen patients) with a symptomatic osteochondral lesion of the talus were examined. The ages of the patients ranged from ten to seventy-eight years (mean, 28.0 years) at the time of the operation, and the patients were followed postoperatively for two to 9.5 years (mean, 4.6 years). After the continuity of the cartilage overlying the lesion and the stability of the lesion had been confirmed, arthroscopic drilling was performed with use of a Kirschner wire that was 1.0 to 1.2 millimeters in diameter. A cast was not applied postoperatively, and full weight-bearing was allowed six weeks after the procedure. RESULTS: The clinical result was good for thirteen ankles and fair for five; all ankles had improvement. Twelve of the thirteen ankles that were in patients who were less than thirty years old had a good result. In contrast, only one of the five ankles in patients who were fifty years old or more had a good result. Thus, the clinical results tended to be better for younger patients. Improvement was seen radiographically in fifteen ankles. However, the three ankles in patients who were more than sixty years old were found to have no improvement on radiographic examination. Analysis of the group of patients who had a history of trauma revealed that the mean interval between the injury and the operation was 6.3 months for the three ankles that had a good radiographic result and 11.3 months for the six that had a fair result. Thus, the radiographic results tended to be better when the interval between the injury and the operation was shorter. CONCLUSIONS: Arthroscopic drilling for the treatment of medial osteochondral lesions of the talus does not require osteotomy of the medial malleolus or postoperative immobilization; thus, the procedure is less invasive than other types of operative treatment for the condition and it allows early resumption of daily activities and sports. On the basis of the results in this study, we believe that the procedure is effective and useful in young patients, especially those who have not yet had closure of the epiphyseal plate. A specific indication for the procedure is an early lesion with only mild osteosclerosis of the surrounding talar bone, continuity of the cartilaginous surface, and stability of the osteochondral fragment.

Adolescent↗
PubMed1999

[Expert systems and automatic diagnostic systems in histopathology--a review].

In this decade, the pathological information system has gradually been settled in many hospitals in Japan. Pathological reports and images are now digitized and managed in the database, and are referred by clinicians at the peripherals. Tele-pathology is also developing; and its users are increasing. However, in many occasions, the problem solving in diagnostic pathology is completely dependent on the solo-pathologist. Considering the need for timely and efficient supports to the solo-pathologist, I reviewed the papers on the knowledge-based interactive expert systems. The interpretations of the histopathological images are dependent on the pathologist, and these expert systems have been evaluated as "educational". With the view of the success in the cytological screening, the development of "image-analysis-based" automatic "histopathological image" classifier has been on ongoing challenges. Our 3 years experience of the development of the pathological image classifier using the artificial neural networks technology is briefly presented. This classifier provides us a "fitting rate" for the individual diagnostic pattern of the breast tumors, such as "fibroadenoma pattern". The diagnosis assisting system with computer technology should provide pathologists, especially solo-pathologists, a useful tool for the quality assurance and improvement of pathological diagnosis.

Expert Systems↗
PubMed1999

[A case of gastric stromal tumor with chest pain and diaphragm elevation].

A 66-year-old woman presented with left chest pain. Left pleural effusion was seen on a chest X-ray film and a large mass disclosed by chest computed tomography. However, the patient refused to undergo a recommended operation. Six months later, she was admitted without any symptoms. A huge (18 cm diameter) mass was detected by magnetic resonance imaging (MRI), and consisted of heterogeneous solid and cystic components. Angiography and endoscopic sonography disclosed a suspected abdominal tumor, which was resected by thoracolaparotomy. Gastric stromal tumor was diagnosed on the basis of histological findings. Chest pain and pleural effusion are rare as initial clinical symptoms of such tumors.

Aged↗
PubMed1999

[Miliary tuberculosis with atypical radiographic findings after aorto-coronary bypass surgery].

Dry cough and exertional dyspnea developed in a 78-year-old man after aorto-coronary bypass surgery for angina pectoris. Chest X-ray films showed small nodular shadows in the upper and middle fields of both lungs. The patient's condition was exacerbated despite treatment with antibiotics. Chest high-resolution computed tomography disclosed small nodular and reticulo-linear shadows predominantly in the interlobular septa and bronchovascular bundles. Transbronchial lung biopsy specimens revealed micro-granulomas with necrosis, suggesting miliary tuberculosis. Antituberculosis drugs were started and the patient's symptoms and radiographic findings gradually resolved. Cases of cellular immunosuppression have beer reported in patients following open-heart surgery that utilized antifical heart and lung apparatus. Such procedures, together with hemodialysis, deserve consideration as potential risk factors for miliary tuberculosis.

Aged↗
PubMed1999

Secondary reconstruction of the extensor tendons and overlying soft tissue deficiency.

Reverse-flow pedicled radial forearm tendocutaneous flap transfers were performed to reconstruct simultaneous skin and tendon defects in the dorsum of the hand in six patients. All flaps survived and four of six patients obtained good functional results. To obtain satisfactory functional outcome, early surgical repair is critical after trauma. The only disadvantage of this operation is unacceptable donor site morbidity.

Adult↗
PubMed1999

Marrow cell culture on poly-L-lactic acid fabrics.

Bone marrow cells from rat femurs were cultured in Eagle Minimum Essential Medium containing 15% fetal calf serum until confluence. After the cells were trypsinized, they were subcultured on fabrics made of biodegradable poly-L-lactic acid for 2 weeks in the medium containing fetal calf serum, ascorbic acid phosphate, beta-glycerophosphate, and with and without dexamethasone. In the presence of dexamethasone, the fabrics showed many mineralized nodules together with cuboidal shaped cells that had osteoblastic activity, as evidenced by high alkaline phosphatase activity and the appearance of osteocalcin messenger ribonucleic acid. However, in the absence of dexamethasone, nodules did not form and many fibroblastic cells appeared with no evidence of osteoblastic activity. These results indicate the possibility of making a hybrid ligament substitute having an in vitro prefabricated bone anchor.

Alkaline Phosphatase↗
PubMed1998

Effocacu and Significance of Sentinel Lymph Node Identification with Technetium-99m-labeled Tin Colloids for Breast Cancer.

PURPOSE: The sentinel lymph node (SLN) is thought to reflect the metastatic status of the remaining axillary lymph nodes in patients with breast cancer. We used technetium-99m-labeled tin colloids to identify SLN. The efficacy and significance of SLN identification using this method were investigated in terms of number, size, location, and tumor metastasis. The efficacy of the emulsion charcoalinjection method for the intraoperative visible identification of SLN was also evaluated. METHODS: Twenty-five patients with invasive breast cancer were studied. Underultrasonographic guidance, technetium-99m-labeled tin colloid particles (3 ml) were injected into 3 sites around the tumor within 3 mm of the margin or into the wall of the excisional biopsy cavity 2 hours before surgery. At surgery, just before the incision, an emulsion of charcoal particles (2.5 ml) was injected into 3 sites of the breast parenchyma surrounding the tumor. All patients underwent mastectomy with axillary dissection to the infraclavicular region. The radioactivity of each dissected lymph node was measured. All axillary specimens were processed in individual blocks for permanent section histopathologic evaluation with H & E. RESULTS: SLN were defined as lymph nodes with 100, 000 or more counts per minute (cpm) in radioactivity after injection of labeled tin colloids. In all 25 patients, SLN were identified (mean, 1.9 SLN/patient; range,1-4). Since the mean uptake in SLN was 383 124 cpm, but only 884 cpm in non-SLN nodes, discrimination between SLN and non-SLN nodes was easy. Clearly visible lymph nodes with charcoalstaining accounted for 83.3% of all SLN, although 21.3% of non-SLN also stained. SLN were located only in the axillary region, but there were no other specific features in the location or size of SLN. The SLN were metastatic in 10 of the 25 patients: in 4, the SLN were the only metastatic nodes whereas in the remaining 6 patients, other axillary nodes were also positive. Fifteen patients with no metastasis in SLN had no tumor involvement in any other lymph nodes. There were no skip metastases. CONCLUSION: SLN identified with labeled tin colloids have clinical value in predicting the metastatic status of the remaining axillary lymph nodes in breast cancer.

Journal Article↗