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Biomedical subjects

T Sugihara

Publications and source records attributed to T Sugihara.

At least 91 records · Page 5Linked to original sources

Expression analysis of mortalin, a unique member of the Hsp70 family of proteins, in rat tissues.

We have investigated the expression of mortalin in rat tissues by Northern analysis, RNA in situ hybridization, and immunohistochemical studies. By Northern assay, the highest level of expression was detected in brain, heart, and skeletal muscle followed by lung, liver, and kidney, and the least level of expression was detected in testis and spleen. RNA in situ and immunohistochemical studies showed that mortalin expression is significantly higher in upper nondividing layers than in the lower basal layers of skin, in neurons and nerve fibers than in surrounding glial cells in brain, in cardiomyocytes than in nonmyocytes in heart, and in interstitial secretory tissue than in germinating follicles in ovary. Such tissue- and cell-specific expression patterns of mortalin coordinates with its earlier reported antiproliferative function in normal cells. However, a deregulation of the expression is observed in rat brain tumor along with the detection of nonpancytosolic mortalin in rat glioma cell line C6. The study suggests that mortalin is involved in pathways that regulate division capacities of cells in vivo.

Animals↗

Quinoline-induced chromosome aberrations and sister chromatid exchanges in rat liver.

Induction of chromosome aberrations and sister chromatid exchanges (SCEs) was studied in hepatocytes of F344 rats exposed in vivo to the hepatocarcinogen quinoline (Q). Hepatocytes were isolated 4-48 hr after a single dose of 200 mg/kg body weight or 24 hr after 28 repeated doses (once a day) of 25-200 mg/kg body weight/day by gastric intubation, and allowed to proliferate in Williams' medium E supplemented with epidermal growth factor. Cells were fixed after a culture period of 48 hr. A single dose of Q induced chromosome aberrations in up to 22% of metaphase cells, and SCEs with a frequency of up to 1.27 per chromosome 12 hr after the dose, while the control values were 1% and 0.63 per chromosome, respectively. Treatment with 28 repeated doses of Q induced significant chromosome aberrations and SCEs dose-dependently. Cytogenetic damage induced induced in the liver by repeated doses of Q was greater than induced by a single dose. Furthermore, Q induced replicative DNA synthesis in the liver, but failed to induce micronucleus formation in the bone marrow. The noncarcinogen 8-hydroxyquinoline was also examined and found to be essentially non-genotoxic to rat liver. These results show that Q is a genotoxic carcinogen to rat liver and the present method of in vivo cytogenetic assay should be useful for evaluating the genotoxicity of hepatocarcinogens.

Animals↗

Treatment of esophageal cancer in patients over 80 years old.

A total of 828 patients with esophageal cancer were treated at the Second Department of Surgery of Tokai University in the 20-year period from 1975 to June 1994, including 45 patients over 80 years old. We reviewed these elderly patients to assess the optimum therapeutic approach for such individuals. In recent years, the number of elderly patients with esophageal cancer has steadily been increasing. Advanced cancer is more common among this group, but early cancer has also been detected more frequently in recent years. Of the 45 elderly patients (80%) in our series, 36 were encountered in the last 10 years. As 28.9% of the patients had multiple cancers, a careful workup was necessary preoperatively. Since most patients (88.9%) had complications and were also in a poor general condition, limited surgery was recommended in consideration of the postoperative quality of life. The indications for endoscopic mucosal resection (EMR) may be able to be extended to submucosal1 (sm1) cancer without lymph node swelling. Postoperative complications occurred in 60% of those undergoing surgical resection or esophageal bypass, although death only resulted in 1 case. The 5-year survival rate after surgical resection was 30.8%. These results therefore support the use of surgical treatment for selected elderly patients with esophageal cancer.

Adult↗

The antithrombotic effects of recombinant human soluble thrombomodulin (rhsTM) on tissue factor-induced disseminated intravascular coagulation in crab-eating monkeys (Macaca fascicularis).

We evaluated the antithrombotic effects of recombinant human soluble thrombomodulin (rhsTM) in plasma and in a monkey model. rhsTM dose-dependently prolonged activated partial thromboplastin time (APTT) in the following order: humans > monkeys > rats >> rabbits. The prolongation of APTT by rhsTM was also observed in protein C-deficient plasma. rhsTM activated protein C and inactivated factor Va in human and monkey plasma, but not in rat plasma. These findings suggest that the antithrombotic activities of rhsTM are fully expressed in human and monkey. Therefore, to evaluate the whole activity of rhsTM in a clinical model, tissue factor (TF) was intravenously infused into crab-eating monkeys to induce disseminated intravascular coagulation (DIC). Pretreatment with rhsTM reduced fall in fibrinogen with a biphasic and moderate dose-dependency curve, and reduced thrombin-antithrombin III (TAT) levels with a flat linear dose-dependency, while heparin prevented fall in fibrinogen with a steep linear dose-dependency curve without reducing TAT levels. Further evidence suggesting that rhsTM activates protein C in vivo was also obtained. Taken together, the data indicate that rhsTM fully expresses its antithrombotic activities in human and monkey but not in rat and rabbit, and rhsTM prevents TF-induced DIC in monkeys by suppressing thrombin generation.

Animals↗

Pelvic ring reconstruction with a vascularized bone flap of femur.

We have used a vascularized bone flap of femur for pelvic ring reconstruction after tumor resection in which amputation of the lower extremity was required. The vascularized femoral graft is an alternative technique in restoration of pelvic ring continuity with vascularized bone autografts.

Adult↗

The rectus abdominis myocutaneous flap combined with vascularized costal cartilages in reconstructive craniofacial surgery.

The efficacy of osteocutaneous or vascularized bone flaps for reconstruction of massive skeletal and soft-tissue defects has been supported by recent descriptions in the literature. In this article we presented an alternative technique, which is the rectus abdominis myocutaneous flap combined with vascularized eighth and ninth costal cartilages, for reconstruction of midfacial composite defects. The vascular pedicle of the composite flap is the deep inferior epigastric artery and vein. The costal cartilages are supplied by the perichondrial vascular network through the anterior intercostal vessels connecting with the deep epigastric vascular system. Vascularized costal cartilages are considered to reduce the incidence of postoperative complications and resorption of this material. This technique is a useful tool for restoration of craniofacial contour in reconstructive head and neck surgery.

Abdominal Muscles↗

Long-term outcome of pressure sores treated with flap coverage.

This article provides our experience with 45 ischial sores and 24 sacral sores in 53 paraplegic patients between 1990 and 1995. Data were evaluated as to the sites of sores and types of the transferred flaps. Types of the transferred flaps were categorized into the fasciocutaneous flap and the myocutaneous or muscle flap. In the treatment of 45 ischial sores, 18 were reconstructed with the fasciocutaneous flaps and 27 with the myocutaneous or muscle flaps. In the treatment of 24 sacral sores, 23 were reconstructed with the fasciocutaneous flaps and 1 with the myocutaneous flap. The recurrence rate was analyzed by percent pressure sore free survival (%PSFS) by the Kaplan-Meier method. Overall, the ischial sores provided a higher recurrence rate than sacral sores; however, there was no significant difference in the %PSFS between the sites of sores. The group of the sores reconstructed with the fasciocutaneous flap demonstrated significant or marginally significant better results in the %PSFS (total of ischial and sacral, p = 0.0155; ischial, p = 0.0555) compared with the group of the sores reconstructed with the myocutaneous or muscle flap. These findings indicated that the use of the fasciocutaneous flap is expected to provide a better long-term result in surgical reconstruction of pressure sores than the myocutaneous or muscle flap.

Adolescent↗

Particulate bioglass compared with hydroxyapatite as a bone graft substitute.

Bioactive ceramics, notably hydroxyapatite, have been used clinically in various situations in which bone augmentation and restoration are required. Particulate material has been used either alone or in conjunction with freeze dried or autologous bone, with variable clinical success. In this study a bioactive glass, 45S5 Bioglass, has been compared with hydroxyapatite in an animal model to discover whether the 2 major disadvantages of hydroxyapatite may be overcome. These are the difficulty of placing and retaining the particulate in the defect and the length of time needed before full bony restoration is achieved. Bioglass is shown to be easy to manipulate and hemostatic and allows full restoration of bone in 2 weeks, rather than the 12 weeks needed for the particulate hydroxyapatite to produce a comparable response. The Bioglass particulate is used up in the process, and any problems that may be associated with the production of a composite of bone and biomaterial are avoided in the fully restored bone. In any procedure that requires bony augmentation, this rapid response to Bioglass is expected to provide a clinical advantage.

Animals↗

[Clinical efficacy of silver sulfadiazine (AgSD: Geben cream) for ulcerative skin lesions infected with MRSA].

The clinical efficacy was evaluated on 1% silver sulfadiazine (AgSD) cream (Geben cream) for the treatment of ulcerative skin lesions infected with MRSA (methicillin-resistant Staphylococcus aureus). 1% AgSD cream was applied once a day to cutaneous ulcers such as burns or decubitus or various other ulcers, infected with MRSA, in 13 patients. MRSA was eradicated in 45.5% of 11 evaluable patients. The clinical efficacy rate of 1% AgSD cream was 72.7% in this series of treatment. No side effects were noted in any of the patients, either locally or systemically. The results of the present study have indicated that 1% AgSD cream is useful for cutaneous ulcers such as burns or decubitus, infected with MRSA.

Administration, Topical↗

Genetic differences between the pancytosolic and perinuclear forms of murine mortalin.

To determine the genetic relation between the pancytosolic (uniformly distributed in cytoplasm-p66mot-1) and the perinuclear (p66mot-2) mortalin proteins found in normal and immortal mouse cells, respectively, we initiated the present study using PCR cloning, sequencing, and single nucleotide primer extension analyses. The results indicate that the difference between mot-1 and mot-2 at 2 bp in the open reading frame does not arise by mutations in the immortalized cells. Intriguingly, both mot-1 and mot-2 sequences were detected in genomic DNA from normal (CMEF) and immortal (RS-4) cells derived from the CD1-ICR mouse strain. We extended the analyses to four other strains of mouse and detected both mot-1 and mot-2 sequences in genomic DNA from the Balb/c mouse also. Swiss and C57BL/6 mice exhibited only mot-2 and the C3H He mouse only mot-1. Southern analyses on a mouse strain that showed the presence of only mot-2 (Swiss) and one that showed both mot-1 and mot-2 (CD1-ICR) by PCR revealed that there are structural differences between mot-1 and mot-2 loci. Furthermore, there appears to be a correlation between frequency of spontaneous immortalization of cultured mouse fibroblasts and the mot loci present in the mouse strain from which they were derived.

Animals↗

Facial contouring surgery with the scapular osteo-adipo-fascial flap.

Recently, deepithelialized scapular or parascapular flaps have been used for reconstruction of facial contour. The authors used a scapular osteo-adipo-fascial flap, based on the subscapular vascular system, accompanied with scapular bone on the angular branch, for surgical correction of facial contour in two cases. At follow-up, both patients showed aesthetic improvements, and were pleased with the results. The scapular osteo-adipo-fascial flap provides a technique to reconstruct facial contour, including the bony structure as well as the soft tissue.

Adult↗

Microsurgical reconstruction of chest- and abdominal-wall defects associated with intraperitoneal vessels.

Microsurgical reconstruction of abdominal or chest-wall defects requires extreme precision but may still raise serious problems. In previous publications many methods have been reported, including free fascia graft, synthetic mesh, pedicled flap, and free flap with microvascular anastomoses. Free-flap transfer has become a popular operative procedure for such reconstructions. The recipient vessels utilized have been mainly the external peritoneal system. In some cases, however, it is very difficult to find adequate recipient vessels in the external peritoneal region. Intraperitoneal vessels may be obviously exposed in the surgical field because there has been a full-thickness defect of the abdominal or chest wall. These vessels are rather easily found and dissected. Their diameter is about 1 to 2 mm, appropriate for microvascular anastomoses with flap vessels in the reconstruction. Using intraperitoneal vessels for the recipient vessels has rarely been reported. The authors report three cases of reconstruction of full-thickness defects of the abdominal or chest wall, using these vessels as recipients for free flaps.

Abdomen↗

Superiority of the microvascularly augmented flap: analysis of 50 transverse rectus abdominis myocutaneous flaps for breast reconstruction.

Our experience with 50 transverse rectus abdominis myocutaneous (TRAM) flap transfers was evaluated as to the types of TRAM flaps, indications for breast reconstruction with a TRAM flap, and complications. The TRAM flap was transferred as a free flap in 7 patients, a unipedicled flap in 14 patients, and a microvascularly augmented flap in 29 patients. Microvascular augmentation was performed through the contralateral inferior epigastric vascular system to the superiorly pedicled muscle in 10 patients who had undergone radical mastectomy and the ipsilateral inferior epigastric vascular system in 19 patients who had undergone modified radical mastectomy. In this series, the incidence of flap-site complications, including total flap loss, partial flap loss, and fat necrosis, was lowest in the microvascularly augmented flap group. Particularly, incidence of partial flap loss in the microvascularly augmented flap group was significantly lower than in the unipedicled flap group (p < 0.01). These outcomes demonstrated the superiority of the microvascularly augmented TRAM flap for breast reconstruction.

Fat Necrosis↗

The combined flap based on a single vascular source: a clinical experience with 32 cases.

This article provides a retrospective review of 32 combined flap transfers. It consists of two or more flaps based on independent vascular branches from a single vascular source. This series included the combined flap based on the subscapular-circumflex scapular-thoracodorsal vascular system in 24 patients and the profunda femorislateral circumflex femoral vascular system in 8 patients. Twenty-four combined flaps were transferred as free flaps and eight as pedicled flaps. The combined flap based on the subscapular system has very good indications for massive and three-dimensional composite defects in the head and neck region. The combined flap based on the lateral circumflex femoral-profunda femoris system is useful for reconstruction of large defects in the groin, perineal, and lower abdominal regions.

Abdominal Neoplasms↗

An anatomic study of the latissimus dorsi-rib flap: an extension of the subscapular combined flap.

The anatomy of the vascular perforators between the latissimus branch of the thoracodorsal vessels and the lateral branch of the dorsal rami of the intercostal vessels was studied in a series of 10 dissections in 5 preserved cadavers to develop the latissimus dorsi myocutaneous flap combined with a vascularized rib. The distances between the communicating perforators and the spinous process and the iliac crest, which become a good guide for design of the rib flap, were measured. An extension of the combined flap including the scapular osteocutaneous flap, latissimus dorsi myocutaneous flap, and vascularized eleventh and twelfth ribs that is nourished by a "single" subscapular vascular system was demonstrated. This technique, which provides a large amount of skin, muscle, and bone, is very effective for reconstruction of an extended composite maxillary and mandibular defect.

Aged↗