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Biomedical subjects

S Tamai

Publications and source records attributed to S Tamai.

At least 163 records · Page 9Linked to original sources

[Pulmonary dirofilariasis with cavity formation and spontaneous regression].

A 70-year-old woman was admitted to our hospital for evaluation of a nodular shadow and an apparent cavity in the right middle lung field. Transbronchial biopsy and percutaneous needle biopsy had failed to result in a diagnosis. Serial chest X-ray films revealed slight regression of the nodule without therapy. Pulmonary dirofilariasis was diagnosed after open-lung biopsy and Ouchterlony's double diffusion test. Cavity formation and spontaneous regression are rare in pulmonary dirofilariasis.

Aged↗

Self-setting hydroxyapatite cement as a carrier for bone-forming cells.

To investigate the feasibility of using self-setting hydroxyapatite cement as a carrier for marrow cells having a high osteogenic ability, a porous form of this cement was fabricated and combined with cultured marrow cells. Marrow cells were obtained from the femurs of a seven-week-old male Fischer 344 rat and cultured in Eagle's MEM containing 15% fetal bovine serum for ten days before being combined with the porous cement or with Interpore 200 hydroxyapatite as a control. The composites were subcutaneously implanted into syngeneic rats and harvested after six weeks. In both types of implants, active osteoblasts together with bone formation were detected in contact with the pore surfaces. No cartilage formation was observed in any of the pores. Both types of implants with and without marrow cells caused very little foreign body reaction. These results indicate that self-setting hydroxyapatite cement containing marrow cells possesses a high osteogenic ability and may be useful as a bone graft substitute as well as a novel delivery system for bone-forming cells.

Animals↗

[Clinico-pathological analysis of airway abnormalities in patients with chronic eosinophilic pneumonia].

Chronic eosinophilic pneumonia is characterized by infiltration of eosinophils into alveolar spaces. Patients with this condition may also have asthmatic episodes, chronic coughing, and bronchorrhea, even after the infiltrative opacity on the chest roentgenogram resolves. We used computed tomography, pulmonary function tests, and biopsies to evaluate the airways of 11 patients with chronic eosinophilic pneumonia. The tomograms showed bronchial wall thickening in all patients at the time of the onset of symptoms and ten months later. Centrilobular peribronchovascular interstitial thickening was detected in four patients, 10 months after the onset. Pulmonary function tests showed that small airway dysfunction remained 13 months after the onset. Pathological analysis revealed airway abnormalities that included basement membrane thickening and cellular infiltration 2 years after the onset. These results show that airway changes had not resolved even after roentgenographic opacities had disappeared. More attention should be given to treatment of airway disease associated with chronic eosinophilic pneumonia, and to whether these changes in the airway are similar to those seen in bronchiolitis obliterans organizing pneumonia.

Adult↗

Patients with ultrasonic coarse-nodular cirrhosis who are anti-hepatitis C virus-positive are at high risk for hepatocellular carcinoma.

BACKGROUND: The relationship between echosonographic patterns of patients with cirrhosis who are antihepatitis C virus (HCV)-positive, the DNA synthesis of hepatocytes, and the risk for HCC were studied. METHODS: Thirty-eight patients with anti-C-100 antibody-positive and Child's grade A posthepatitic cirrhosis were studied. DNA synthesis activity was measured by a bromodeoxyuridine (BrdU, a thymidine analogue)-labeling index (LI), using the BrdU-anti-BrdU in vitro method, and the patients were followed prospectively by frequent liver ultrasonography for 3 years. The ultrasound patterns were classified into fine, coarse, and coarse-nodular (CN) patterns, and the reproducibility of the classification in practical use also was confirmed. RESULTS: Of the 21 patients with high DNA synthesizing cirrhosis (BrdU LI > or = 1.5%), 10 (48%) showed coarse-nodular, 5 (24%) coarse, and 6 (29%) fine pattern in ultrasonography. Conversely, of the 17 patients with low DNA synthesizing LC (BrdU LI < 1.5%), only 1 (6%) showed coarse-nodular, 2 (12%) coarse, and 14 (82%) fine pattern. A significant relationship was found between the two groups of BrdU LI and ultrasound imaging patterns (P < 0.05). The incidence of CN pattern was significantly higher (P < 0.01) in the high DNA synthesizing group than in low DNA synthesizing group. Of the 11 patients with CN pattern by ultrasound imaging, 10 (91%) were in the high DNA synthesizing group, and 9 (82%) developed HCC during the follow-up period, compared with 3 of 7 (43%) with coarse, and only one of 20 (5%) with fine pattern developed HCC. The incidence of HCC was significantly higher (P < 0.01) in patients with a CN cirrhosis pattern than in those with a fine pattern. CONCLUSIONS: In patients with cirrhosis who are anti-HCV-positive, the CN pattern by ultrasound imaging indicates increased DNA synthesis of hepatocytes and a high risk for developing HCC.

Adult↗

Central motor reorganization after anastomosis of the musculocutaneous and intercostal nerves following cervical root avulsion.

In 4 patients with a complete upper limb palsy due to traumatic cervical root avulsion, surgical anastomosis of intercostal to musculocutaneous nerves was performed to restore function in the biceps brachii muscle. Four to 6 months after the operation, motor unit discharges were recorded from the biceps muscle on the operated side during deep breathing and by cortical magnetic stimulation. The motor unit discharges became independent from respirations gradually over 1 to 2 years. The latencies of the motor potentials evoked by cortical and thoracic root magnetic stimulation decreased gradually over 2 to 3 years. Motor cortex mapping of the reinnervated biceps muscle showed a gradual change over 4 to 33 months from the area of the intercostal muscles to that of the arm area, which was more lateral on the motor cortex. These findings suggest that reorganization of the motor cortex to arm flexor muscles occurs following peripheral nerve anastomosis.

Accidents, Traffic↗

Evaluation of vascular compliance and vasoconstrictive reactions in amputated hindlimbs of rats.

The vascular compliance and the contractility of vascular smooth muscle of preserved, amputated hindlimbs of rats 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 80-150 mm Hg [10-20 kPa]) and found not to differ significantly from that of freshly amputated limbs after storage at 4 degrees C for 12 hours. However, after more than 24 hours of storage at 4 degrees C, the vascular compliance decreased significantly (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 could be preserved for at least 12 hours at 4 degrees C; however, it decreased markedly after more than 24 hours. The vascular compliance and vasoconstrictive reactions of the amputated limbs were maintained for at least 12 hours at 4 degrees C.

Amputation, Surgical↗

Experimental vascularized bone transplantations.

The postoperative hypertrophy of the vascularized fibula graft is of particular interest. In order to clarify the etiology of the hypertrophy, we conducted experimental projects on vascularized bone grafts using fluorochrome bone labelings, histomorphometry and measurement of blood flow in rats and rabbits. In the murine vascularized tibio-fibula graft for bone defects of the tibia, where mechanical stress to the graft can be expected, cross-sectional bone growth was maintained with acceleration of new bone formation and an alteration of growth direction at 3 weeks after the transplantation. In vascularized bone grafts where no mechanical stress to the graft is expected, more bone resorption was seen than bone formation. In the murine tail bone graft to a bony defect of the femur, the cancellous bone gradually disappeared, and the trabeculae took on an architecture characteristic of the femur. This process slowly transforms the graft into a femur with the morphologic features of a long bone. These results suggested that remodeling of the graft corresponding with the changes in the dynamic environment was accompanied by adequate resorption. The cross-age transplantation of vascularized tibio-fibula grafts in rats showed that the younger the donor, the faster the hypertrophy. Age is one of the important factors affecting remodeling of the vascularized bone graft. The blood flow of the grafted bone in the rabbits increased immediately after the transplantation as a reaction to surgery. Thereafter the blood flow of the graft may depend on the biological demands for new bone formation in adapting to the biomechanical environment of the recipient site.

Age Factors↗

Mandibular reconstruction using the double barrel fibular graft.

Five patients underwent mandibular reconstruction using the double barrel fibular graft from 1989 to 1994. Bony defects ranged from 7 to 14 cm. In three patients, two skin flaps were taken with the fibular graft for composite reconstruction. In order to overcome the main disadvantage of the fibular graft, i.e., small circumference of the bone, a harvested fibula was osteotomized into several portions, folded into two parallel lengths, and fixed along the inferior border of the mandible and the alveolar ridge. The double barrel fibular graft provided more than 4-cm alveolar height without damaging bone viability. In Orientals, a fibula is approximately 1.5 cm thick, and using a single fibular strut for mandibular reconstruction may result in subsequent difficulty in wearing conventional dentures or osseointegrated implants. All patients acquired good mandibular contour and enough thickness of the alveolar ridge, and could wear a conventional denture and eat a solid diet. This procedure seems to be superior to the iliac bone graft for major mandibular reconstruction because of its length, the possibility of three-dimensional composite reconstruction, increased bone thickness, and minimal donor-site morbidity.

Adolescent↗

Aneurysms of the digital artery: a review and report of three cases.

Aneurysms of the digital artery are rare. Since 1980, we have treated three traumatic aneurysms of the digital artery. There were two lesions of the common palmar digital artery and one of the ulnar pollicis artery. One case was caused by a traumatic laceration with a kitchen knife, and two cases were caused by repetitive microtrauma. On histologic examination, there were two true aneurysms and one false aneurysm. Two cases were treated by excision only, and one case was treated by excision and reanastomosis. The operating microscope was useful during neurolysis, excision of the aneurysm, and vascular anastomosis.

Adolescent↗

Experimental study on choline acetyltransferase activity measurement for brachial plexus injury.

We studied choline acetyltransferase (CAT) activity in a rat model of brachial plexus injury. In experiment 1, we found that the CAT activity was remarkably high in the anterior roots and low in the posterior roots. In experiment 2, nerve root segments were extracted and examined for CAT activity in the root avulsion group (group A) and the plexus severance group (group B). CAT activity decreased day by day in group A, reaching about 1/20 of the normal 5 days postoperatively. By contrast, in group B activity decreased only slightly, and even at 90 days postoperatively was about 6,000 cpm (one-half normal level). As a result, CAT activity enabled us to distinguish postganglionic from preganglionic injury of the cervical roots. Furthermore, it was a useful adjunct for minimizing nerve loss in intercostal nerve transfer, distinguishing motor and sensory branches of the intercostal nerve, and evaluating the motor nerve activity.

Animals↗

PCNA immunostaining combined with AgNOR staining in esophageal squamous cell carcinoma to identify patients with a poor prognosis.

Immunostaining of the proliferating cell nuclear antigen (PCNA) provides important information about cell kinetics and is easily performed on routinely obtained formalin-fixed, paraffin-embedded materials. We report herein the results of a retrospective study on PCNA staining in esophageal cancer undertaken to determine its significance. As this study indicated that immunoreactivity was preserved in specimens fixed within 24h, only 31 specimens from surgical patients were available for this investigation. The mean PCNA index of the patients without invasion to the adventitia (35.7 +/- 17.9) was significantly lower than that of those with invasion to the adventitia or neighboring structures (49.7 +/- 14.5), while the PCNA index did not correlate with other clinicopathologic parameters such as histologic type, lymph node metastases, or prognosis. However, when an analysis of PCNA staining was combined with an analysis of argyrophilic nucleolar organizer region (AgNOR) staining, a correlation with prognosis was found. In fact, seven patients with a high PCNA index (> or = 44) and AgNOR count (> or = 6) had a significantly poorer prognosis than the remaining 22 (P = 0.0014), and six of these seven patients died within 2 years. These results indicate that this combined evaluation may be useful for the identification of patients with a poor prognosis among those undergoing surgery for esophageal squamous cell carcinoma.

Adult↗

Chondromatosis within a meniscal cyst of the knee.

A 32-year-old man complained of left gonalgia for 2 years and noticed a soft part tumor on the lateral side of his left knee. Roentgenograms showed some small calcified shadows at the same site of the tumor. Arthroscopy revealed a lateral meniscus to be an incomplete discoid with degenerative tears. At the operation, a multilocular soft part tumor was noticed in continuity with the lateral meniscus macroscopically. Small, loose bodies and gelatinous fluid were found in the cavity of the tumor. Histologically loose bodies were chondroma and the soft part tumor was meniscal cyst. The meniscal cyst wall contained hyaline cartilagenous tissue. Therefore it was thought that chondroma originated from the cyst wall.

Adult↗

Prefabricated vascularized periosteal grafts using fascial flap transfers.

The purpose of this study was to demonstrate the feasibility of prefabricated vascularized periosteal grafts using fascial flap transfers. Fifty rats were divided into two (Group A, underwent periosteal wrapping, and Group B underwent fascial wrapping). Fascial flap from the medical leg, which were nourished by the saphenous artery and vein, were used for all grafts. In Group A, the fascia was transferred onto the proximal tibial periosteum. Two weeks postoperatively, the elevated fascioperiosteal flap was wrapped around a 4-mm hydroxapatite cube. In Group B, the fascial flap was immediately wrapped around the hydroxyapatite cube. In both groups, the hydroxapatite-wrapped cube was transferred to the inguinal region. Three days postoperatively, five rats from group A were sacrificed. On histologic examination, these five showed no necrosis of the fascioperiosteal flap and no bone formation. The remaining 45 rats were sacrificed 5 weeks postoperatively. Microangiography was performed on five rats in Group A, revealing neovascularization of the hydroxyapatite. On histologic examination, new bone formation was confirmed in 15 of the remaining 20 rats in Group A, and in three of the 20 rats in Group B. These experiments demonstrated that the prefabricated vascularized periosteal graft, which has good osteogenic capacity, could be carried out using a fascial flap transfer.

Angiography↗

"Plasmatic imbibition" in the rabbit flow-through venous flap, using horseradish peroxidase and fluorescein.

In the present study, the phenomenon of "plasmatic imbibition" was investigated histologically in a rabbit flow-through venous flap model, using horseradish peroxidase and fluorescein. Horseradish peroxidase introduced between the flap and the recipient bed, produced brown staining of the entire contact surface 10 min postoperatively. At 30 min, erythrocytes in the flow-through vein stained red. The flap and the erythrocytes became more intensely stained over time. When horseradish peroxidase was introduced from a central artery after a Silastic sheet had been inserted between the flap and recipient bed, the flap color became a soft brown and the erythrocytes of the flow-through vein stained red 10 min postoperatively. In the experimental groups subjected to fluorescein, introduced between the graft (or flap) and the recipient bed, fluorescence was seen 10 min postoperatively, except in the flow-through vein. At 30 and 120 min, the whole graft (or flap) showed fluorescence. Fluorescein was introduced into the femoral vein after flap elevation, or a Silastic sheet was inserted between the flap and the recipient bed. At 10 min, these groups showed a weak fluorescence only in the flow-through vein; subsequently, at 120 min, the flow-through vein and its surrounding tissue showed fluorescence, but the flap showed none. Plasmatic imbibition was proved to be acting in the flow-through vein, and it is considered as important a phenomenon in flap survival as venous flow itself.

Animals↗

Paget's disease of the esophagus. A case report with review of the literature.

A 59-year-old Japanese man with Paget's disease of the esophagus is reported. The epithelium in the upper-to-middle portion of the esophagus was extensively infiltrated by Paget's cells. There was a minimal submucosal invasive area showing features of undifferentiated carcinoma. Histochemical and immunohistochemical studies showed glandular differentiation of the intraepithelial Paget's cells. Electron microscopic study demonstrated distinctive intraepithelial growth of the Paget's cells with the formation of desmosomes with nonneoplastic squamous cells, but there was no definitive evidence of glandular differentiation of the Paget's cells. These findings suggest that the entity in this case was probably adenocarcinoma in situ originating in the components of the esophageal epithelium, such as the intraepithelial or other portions of the esophageal gland ducts, with focal invasion and anaplasia. The additional control study of 154 cases of esophageal carcinoma revealed two other cases showing localized pagetoid extensions.

Esophageal Neoplasms↗

Partial soleus muscle island flap transfer using minor pedicles from the posterior tibial vessels.

A new method for partial soleus muscle island flap transfer using minor pedicles from the posterior tibial vessels was designed and executed. A portion of the soleus muscle body that was slightly wider than the defect was harvested with minor pedicles. The muscle flap was transposed by turning it over or by creating an island flap. Skin grafts were applied to the exposed muscle. This new type of muscle flap was applied to six patients with a pretibial skin defect at the lower third of the leg. It was used for treatment of an open fracture with an associated skin defect in four patients, chronic osteomyelitis in one patient, and a recurrent stasis ulcer in one patient. In all patients the transferred muscle flap survived completely.

Aged↗