Biomedical subjects

T Sugihara

Publications and source records attributed to T Sugihara.

At least 19 recordsLinked to original sources

PubMed1999

Late expression of red cell membrane protein 4.2 in normal human erythroid maturation with seven isoforms of the protein 4.2 gene.

The expression of protein 4.2 in normal human erythroid cells was studied utilizing erythroblasts from bone marrow and erythroid cells cultured by the two-phase liquid culture method from burst-forming unit erythroid (BFU-E) in peripheral blood. As opposed to spectrin, which was expressed in erythroid progenitors or very early erythroblasts, protein 4.2 was first detected in late erythroblasts with a morphology nearly identical to orthochromatic erythroblasts. Among the various major membrane proteins, the expression of protein 4.2 was the latest. At the gene level, protein 4.2 gene mRNA was expressed in early erythroblasts. During normal erythroid maturation, the expression of seven different protein 4.2 gene products was observed by Southern blot analysis. These seven gene products appeared to be derived from protein 4.2 gene in the presence or absence of skipping of the 90 bp in exon 1, exon 3, and/or exon 5, as judged by deduction from the protein 4.2 sequence. Therefore, it can be speculated that protein 4.2 is expressed after the cytoskeletal network has been constructed and assembled with integral proteins in the membrane lipid bilayer.

Blood Proteins↗

PubMed1998

A novel alternatively spliced form of murine vascular endothelial growth factor, VEGF 115.

Murine immortal fibroblasts express a form of vascular endothelial growth factor (VEGF) that was cloned, characterized and named VEGF 115. It differs from VEGF 120 by 37 amino acids at the carboxyl terminus. VEGF 115-specific sequence reacted to a single transcript in mouse tissues. Reverse transcription-polymerase chain reaction was performed in mouse tissues and in fibroblasts of normal and immortal divisional phenotypes. The data from mouse tissues suggested that VEGF 115 is not a tissue-specific isoform of VEGF 120, whereas a functional relevance with immortalization is indicated from the latter. The novel cDNA was expressed in Escherichia coli, and the His-tagged VEGF 115 (17.2 kDa) thus obtained was recognized by anti-VEGF antibody. A mammalian expression plasmid, pCMVneo+, encoding for VEGF 115 was transfected to NIH 3T3 cells, and the conditioned medium of stable transfectants was found to have fibroblast growth factor-replacing activity for human umbilical vein endothelial cells. Two independent genomic P1 clonings with primers specific for VEGF 164 and VEGF 115, respectively, resulted in isolation of identical P1 clones. We analyzed these three P1 clones on Southern blots with common and specific probes for VEGF 164 and VEGF 115. The results support the hypothesis that VEGF 115 is a new alternatively spliced form of mouse VEGF.

Alternative Splicing↗

PubMed1998

Representation of objective similarity among three-dimensional shapes in the monkey.

Humans have been recently shown to represent parameterized three-dimensional objects in a manner that preserves relative similarities (as measured by parameter-space distances) among the objects (Cutzu and Edelman 1996). We show that the representation of objects in the monkey visual system is similarly faithful to the parametric variation built into the stimulus set. A monkey (Macaca fuscata) performed a delayed matching-to-sample task with 28 images (4 views x 7 objects). Stimuli in each of the two experiments were seven computer-rendered parameterized animal-like shapes, arranged in a low-dimensional configuration (namely, a two-dimensional TRIANGLE) in a common 56-dimensional parameter space. The monkey's task was to match objects (not views). Each experiment lasted for 3-4 weeks after the introduction of the stimulus set to the subject. Error rates were entered into a 7 x 7 object confusion matrix and submitted to nonmetric multidimensional scaling (MDS). In both experiment 1 (mean correct rate 69.7%) and experiment 2 (mean correct rate 59.9%), the MDS solutions resembled closely the low-dimensional parameter-space patterns built into the stimuli, in the sense that the point corresponding to the central one in the original pattern was inside the other six points and that the order of the six points in angular positions around the center point was preserved. A simulation study showed that the resemblance could not be due to chance. These results demonstrate the possibility of veridical representation of parametric similarity among complex objects in the monkey.

Animals↗

PubMed1998

Functional and morphological damage of endothelium in rabbit ear artery following irradiation with cobalt60.

1. The relaxant actions of acetylcholine and A23187 were examined in the rabbit central ear artery at different intervals following exposure to different doses of radiation with a cobalt60 unit. The artery was irradiated with a dose of 10 Gy, 20 Gy and 45 Gy. Radiation caused dose- and time-dependent impairment of the endothelium-dependent relaxations. The impaired endothelium-dependent relaxations occurred as early as 1 week postirradiation and persisted throughout the experimental period (10 weeks). 2. The endothelium-independent response to sodium nitroprusside was well preserved up to 6 weeks after irradiation. The contractile response to noradrenaline was unaltered by irradiation throughout the experimental period, but in contrast to control vessels, an increase in the sensitivity to noradrenaline in the presence of the nitric oxide synthase (NOS) inhibitor N(G)-nitro-L-arginine was not observed in the irradiated vessels. 3. The impaired endothelium-dependent relaxations in the irradiated vessels were not improved by pretreatment with the NOS substrate L-arginine, the cyclo-oxygenase inhibitor indomethacin or the free radical scavengers superoxide dismutase and catalase. 4. Scanning electron microscopy indicated morphologically intact endothelial cells within the first 4 weeks after irradiation. 5. Western blot analysis showed a significant decrease in the expression of endothelial NOS (eNOS) in the irradiated vessels. 6. These data indicate that endothelial cell function is specifically impaired in the irradiated vessels before morphological endothelial cell damage can be detected. This impairment may be related to diminished eNOS expression.

Animals↗

PubMed1998

Homozygous missense mutation (band 3 Fukuoka: G130R): a mild form of hereditary spherocytosis with near-normal band 3 content and minimal changes of membrane ultrastructure despite moderate protein 4.2 deficiency.

The characteristics of phenotypic expression were studied in a Japanese family with hereditary spherocytosis and an extremely rare homozygous missense mutation of the band 3 gene (band 3 Fukuoka: G130R). The homozygous unsplenectomized proband was a 29-year-old male with compensated haemolytic anaemia (red cell count 4.21 x 10(12)/l, reticulocytes 278 x 10(9)/l, and indirect bilirubin 44 micromol/l). His red cell band 3 (B3) protein demonstrated a 9.3% reduction and his protein 4.2 (P4.2) level was substantially reduced (45.0%), compared to normal subjects. P4.2 protein was composed mostly of a wild type (72 kD) with a trace of 68 kD peptide. The binding properties of the mutated B3 to normal P4.2 were significantly impaired, which probably resulted in the substantial reduction of P4.2 in this proband, since no abnormalities were detected on the P4.2 gene. Electron microscopy (EM) using the freeze-fracture method demonstrated a mild decrease in intramembrane particles (IMPs) of near-normal size (8 nm in diameter) with no substantial increases in their oligomerization. Their distribution on the membrane P face was almost normal, although most of the IMPs could represent the homozygously mutated B3 protein. EM (quick-freeze deep-etching method) disclosed a skeletal network of near-normal size and size distribution of the skeletal units, suggesting that the mutated B3 protein itself did not have much effect on the skeletal network in situ. Therefore the reduced P4.2 content (45% of that of normal subjects), which remained on the red cell membrane of this proband, appeared to be nearly sufficient for maintaining the normal structure of the skeletal network and IMPs in situ, contrary to the marked abnormalities in both IMPs and the skeletal network in complete P4.2 deficiencies.

Adult↗

PubMed1998

Application of reduction mammaplasty in treatment of giant breast tumour.

Reduction mammaplasty has been the traditional method for managing breast hypertrophy or severe ptosis in the field of plastic surgery. We describe two patients with giant breast hamartomas treated with the application of reduction mammaplasty by either the superior or inferior pedicle technique. Both had satisfactory results with symmetry of breast projection and nipple-areola complex placement. Standard plastic surgical techniques may be effectively applied in the treatment of giant breast tumours which compromise the aesthetic appearance of the breast.

Adolescent↗

PubMed1998

Arterial changes following single-dose irradiation.

In this reported experiment, the serial morphologic changes in the rabbit ear central artery, following a single dose of 45 Gy 60Co gamma-ray irradiation, were investigated using light and scanning electron microscopy. Under light microscopy, mild intimal proliferation, disorganization of smooth muscle, and severe perivascular fibrosis were observed. These appeared to be caused by increased intimal cell death and lower repair capability after large single-dose irradiation. Under scanning electron microscopy, the endothelial cells did not show significant morphologic changes during the first 4 weeks. At 6 and 10 weeks after irradiation, the endothelial cells shrank in all directions and detached from the basement membrane. These changes accord with the theory that radiation damage following therapeutic dosage occurs within the DNA of the cell, and that there is no significant change until the cell attempts to divide.

Animals↗

PubMed1998

Microsurgical reconstruction of the digestive tract following pharyngolaryngectomy and total esophagectomy.

Total pharyngoesophageal reconstruction has remained a challenging field in digestive surgery. During the past 3 years, the authors performed six microsurgical reconstructions of the digestive tract following pharyngolaryngectomy and total esophagectomy due to a multiple cancer or skip metastasis. Digestive continuity was restored using a combination of a pulled-up gastric pedicle and free jejunal transfer in 2 patients, and an elongated gastric pedicle with microvascular augmentation in 4 patients. One elongated gastric pedicle developed partial necrosis, and a free jejunal graft was placed additionally. One patient suffered from respiratory dysfunction and died 1 month after surgery. Postoperative radiographic examination showed a good swallowing mechanism without reflux and stasis in all patients. Microvascular surgery contributes to the successful reconstruction of the digestive tract following extensive pharyngolaryngoesophagectomy.

Aged↗

PubMed1998

Microsurgical lymphaticovenous implantation for the treatment of chronic lymphedema.

This article presents our experience with microsurgical lymphaticovenous implantation in the treatment of chronic lymphedema. Our attempt is to create a lymphaticovenous shunt with an implantation of the collecting lymphatics, including some lymphatic vessels and lymphatic capillaries, within external connective adventitial and adipose tissue into the small vein. Precise placement of the sutures in the lymphatic vessels is not required in this technique. The external connective adventitial and adipose tissue seals the gap between the collecting lymphatics and vein. Our clinical results with five upper and three lower extremities with chronic lymphedema demonstrated the effectiveness of this technique. This easy and simple method could be used widely and could provide stable improvement of chronic lymphedema.

Aged↗

PubMed1998

Role of buttress reconstruction in zygomaticomaxillary skeletal defects.

The purpose of this study was to review eight patients undergoing midfacial skeletal reconstruction following extensive resection of tumors based on the principles of restoration of three maxillary buttresses, the nasomaxillary, zygomaticomaxillary, and pterygomaxillary. The zygomaticomaxillary skeletal defects were reconstructed with a three-dimensionally contoured piece of titanium mesh, vascularized costal cartilage, or vascularized bone flap of scapula and rib. Restoration of the zygomaticomaxillary buttress prevented the inferior deviation of the orbit and provided good zygomatic contour. Restoration of the nasomaxillary buttress prevented the superior and posterior deviation of the alar base of the nose, and restoration of the pterygomaxillary buttress prevented the superior and posterior deviation of the upper lip. Combination of the V-shaped scapular bone and the rib flap based on the thoracodorsal vascular system, which provides simultaneous reconstruction of all three buttresses, is a very versatile technique for reconstruction of extended midfacial skeletal defects. In this series, both of the patients reconstructed with titanium mesh presented with late persistent cutaneous fistulas. We now recommend a vascularized autologous soft and bony tissue reconstruction for midfacial composite defects.

Adult↗

PubMed1998

A fiberscopic analysis of velopharyngeal movement before and after primary palatoplasty in cleft palate infants.

There have been few studies done on the abnormal function of velopharyngeal muscles in unrepaired cleft palate infants. To examine and assess velopharyngeal movement before primary palatoplasty offers supposedly any valuable information for the successful operation and the restoration of excellent velopharyngeal function. We designed to investigate and analyze velopharyngeal movement before and after primary palatoplasty in 26 cleft palate infants with a fine nasopharyngeal fiberscope. We found three different patterns of velopharyngeal movement in unrepaired cleft palate infants when crying or strangulation reflex occurred: (1) posterior movement type (10 cases, 38.5 percent), where the soft palates moved only posteriorly and cephalically and did not move medially; (2) medial movement type (10 cases, 38.5 percent), where the soft palates moved only medially and did not move posteriorly or cephalically; and (3) posteromedial movement type (6 cases, 23.0 percent), where the soft palates moved both posteriorly and cephalically as well as medially. Postoperative velopharyngeal closure was classified into three patterns: (1) the soft palate type, in which the soft palate mainly operates; (2) the lateral wall type, in which compensational medial movement of the lateral pharyngeal wall is mainly observed; and (3) the mixed type, in which both the soft palate and the lateral pharyngeal wall operate. Also, we demonstrated a close relationship between velopharyngeal movement before and after primary palatoplasty in cleft palate infants. In total, 10 of 16 cleft palate infants with the posterior movement type or posteromedial movement type, in which posterior movement of the soft palates was observed before primary palatoplasty, postoperatively showed the soft palate type of velopharyngeal closure. On the other hand, only 2 of 10 cleft palate infants with the medial movement type, in which the soft palates did not move posteriorly but medially before primary palatoplasty, postoperatively showed the soft palate type of velopharyngeal closure. The Fisher's exact probability test clarified that cleft palate infants with the posterior movement type or posteromedial movement type were more likely to show postoperatively the soft palate type of the velopharyngeal closure compared with those with the medial movement type (p = 0.051). This is the first trial to examine velopharyngeal movement in unrepaired cleft palate infants. Our findings indicate the probability that velopharyngeal closure mechanism in repaired cleft palate infants is able to be predicted by velopharyngeal movement behavior before primary palatoplasty. Next, we must clarify a correlation between preoperative velopharyngeal movement and postoperative velopharyngeal function and speech outcome.

Cleft Lip↗

PubMed1998

Clinical application of expanded free flaps based on primary or secondary vascularization.

Prefabricated free flaps using an expansion technique were used for four reconstructive cases, including two leg reconstructions and two facial reconstructions. In this series, the prefabricated free flaps created by using the expander were classified into two types: the expanded flap based on the conventional vascular pedicle, which is called the expanded flap with primary vascularization; and the expanded flap based on the vascular pedicle in the carrier, which is called the expanded flap with secondary vascularization. The expanded flap with primary vascularization that is created in the trunk has a good indication for leg reconstruction, because it provides an wide and thin flap with minimal donor site morbidity. The expanded flap with secondary vascularization created in the pectoral region has a good indication for facial reconstruction, because it provides good color and texture matches. Although there are some disadvantages in the tissue expansion technique, the prefabricated free flaps using the expander are very effective in facial and leg reconstruction.

Adolescent↗

PubMed1998

Functional alveolar ridge reconstruction with prefabricated iliac crest free flap and osseointegrated implants after hemimaxillectomy.

We achieved functional alveolar ridge reconstruction after hemimaxillectomy using a prefabricated iliac crest flap. The iliac crest was vascularized secondarily by a long rectus abdominis muscle flap with its inferior epigastric vessels intact to obtain an ideal anatomic location between the maxillary defect and microvascular anastomosis site. The iliac crest was tightly resurfaced with a split-thickness skin graft as well. After a bony surgical delay, the prefabricated iliac crest flap was microsurgically transferred to the face. Three osseointegrated implants were placed in the prefabricated iliac crest, and a dental prosthesis was worn with immobilization and stability. Our procedure enabled recovery of a satisfactory facial appearance and excellent masticatory function.

Adult↗

PubMed1998

A case of congenital infantile fibrosarcoma of the right hand.

Congenital infantile fibrosarcoma is a rare soft-tissue malignant tumor that usually presents as a mass involving the arm or leg. We report a case of congenital fibrosarcoma on the right hand of a newborn infant. The patient was a 12-day-old male. From the time of delivery, he had a red tumor on his dorsal right hand. The tumor was initially associated with bleeding within a hemangioma and compressed. The course was observed. It appeared that the tumor might be malignant because it increased in size to 10 x 8 x 3 cm, and ulceration and bleeding appeared on the surface after 10 days. A biopsy suggested a fibrosarcoma. The tumor was resected 32 days after birth at the narrow margin in consideration of preservation of function. However, a recurrence was observed under the graft after 2 weeks and another resection was performed. Because the tumor had passed through the interosseous muscle and invaded the palm of the hand, the middle finger, ring finger, and little finger had to be amputated. One year and 7 months postoperatively, no recurrence or metastasis has been observed.

Fibrosarcoma↗

PubMed1998

Functional reconstruction of the tongue and deglutition muscles following extensive resection of tongue cancer.

The authors describe their experience with functional restoration of tongue and deglutition muscles at the floor of the mouth after an extensive resection of tongue cancer. Five patients underwent immediate tongue reconstruction using a reinnervated rectus abdominis myocutaneous free flap in which the included tenth intercostal nerve was coapted to the remaining hypoglossal nerve. The rectus sheath strips attached on both cut ends of the muscle were used to create the firm tendinous insertions between the mandible and hyoid bone based on the anatomic findings of the extrinsic tongue and suprahyoid muscles. The postoperative course was uneventful in all patients. All patients presented with good tongue bulk without obvious atrophy. Three patients with subtotal glossectomy demonstrated good cooperative mobility of the reconstructed and remaining tongue and had solid or semisolid/soft diet. However, two patients with total glossectomy did not show satisfactory rehabilitation of the reconstructed tongue. Postoperative electromyographic assessment in two patients showed good functional recovery of the grafted muscle. The cine-magnetic resonance imaging deglutition study in one patient with 80-percent tongue resection demonstrated sufficient elevation of the dorsal base of the reconstructed tongue, contraction of the reconstructed deglutition muscles, complete glossopalatal closure, and elevation of the hyoid bone and larynx during the deglutition. This reconstructive technique is strongly recommended for the patients who have undergone subtotal glossectomy to provide physiological functional recovery of the reconstructed tongue synchronizing with the remaining tongue.

Adult↗

PubMed1997

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↗

PubMed1997

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↗

PubMed1997

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↗