Search PubMed⌕ Search

Biomedical subjects

T Sugihara

Publications and source records attributed to T Sugihara.

At least 109 records · Page 6Linked to original sources
PubMed1996

The effect of a collagenous implant on deep dermo-periosteal defects in the rabbit.

In plastic surgery, extensive wounds with exposed bone and loss of the periosteum (i.e., deep dermo-periosteal defects) are difficult to treat, even with split-thickness skin grafts, because such grafts rarely survive. Even when these grafts do survive, functional impairment often occurs subsequently. The application of a collagen sponge (Terudermis, Terumo, Tokyo) to such wounds has previously been reported to accelerate granulation tissue formation, resulting in would healing and graft survival. However, this previous report only presented data relating to gross morphological appearance. In this paper, we present histological evidence to demonstrate the beneficial effect of the collagen sponge on experimental dermo-periosteal scalp defects in rabbits. About two weeks after the application of collagen sponge to the experimental wounds, a well-vascularized granulation tissue was formed. Autologous split-thickness skin grafts applied to this new granulation tissue were found to be viable one week after grafting. The results confirm histologically that collagen sponge is effective for the treatment of deep dermo-periosteal defects which would not have regenerated skin cover with conventional therapies such as skin grafting or the temporary use of dermoprotective materials followed by skin grafting.

Animals↗
PubMed1996

Japanese siblings with missense mutation (717Val --> Ile) in amyloid precursor protein of early-onset Alzheimer's disease.

We report Japanese siblings with the missense mutation 717Val --> Ile in the amyloid precursor protein. The maternal grandmother died of an unknown dementing disorder. The proband's mother had gradually increasing amnesia beginning at age 64, which was diagnosed as Alzheimer's disease (AD). She died in a psychiatric hospital (duration of illness: 16 years). Both the proband and her elder sister were affected at about age 55 years. Disturbances of memory, judgment, and emotion, as well as personality changes, occurred first, with dementia eventually predominating. The elder sister died of pneumonia (duration of illness: 9 years). The amyloid precursor protein (APP) gene was analyzed from each sibling. Genomic DNAs obtained from blood samples were amplified by the polymerase chain reaction (PCR) method. PCR products were digested with the restriction enzyme Bcl I. The resulting restriction fragment length polymorphisms (RFLPs) showed the missense mutation 717Val --> Ile in both patients, but not in a normal control. DNA sequencing showed the presence of the 2149G --> A missense mutation only in the patients. We conclude that this familial AD may originate from the missense mutation 717Val --> Ile in the amyloid precursor protein gene and that the clinical picture is typical of AD, except for normal-pressure hydrocephalus and psychiatric phenomena.

Age of Onset↗
PubMed1996

Effects of lipo-prostaglandin E1 on random pattern flaps in rabbits.

The effects of lipo-prostaglandin (PG) E1, which are lipid microspheres containing PGE1, were examined using 2 x 12 cm random pattern skin flaps on the backs of five rabbits. Five rabbits acted as controls. Both surviving length (8.5 (3.1) compared with 4.9 (1.8) cm) and surviving area (22.1 (9.3) compared with 11.5 (6.1) cm2) of the skin flap were significantly increased (p < 0.03 in each case). In three additional rabbits the blood flow on the distal side of the skin flap, where it was poor, was measured using a laser image blood flowmeter. Blood flow was improved five to 15 minutes after injection of lipo-PGE1 and was maintained for at least 60 minutes. In conclusion, lipo-PGE1 increased the blood flow of the random skin flaps, resulting in significant enlargement of the surviving area of skin flaps.

Alprostadil↗
PubMed1996

[Five cases of hereditary high red cell membrane phosphatidylcholine hemolytic anemia in three families].

Five cases of hereditary high red cell membrane phosphatidylcholine hemolytic anemia in three families were described. All cases were clinically manifested by jaundice and splenomegaly. Hemolysis was evident from indirect hyperbilrubinemia, reticulocytosis and decrement of serum haptoglobin. Red blood cells showed morphological abnormalities such as poikylocytosis, anisocytosis and target cells on blood smears. Both direct and indirect Coombs' tests were negative. Ham test, sugar water test and hemoglobin electrophoresis showed no abnormalities. Osmotic fragility test showed decreased membrane fragility. Lipid analysis of red cell membrane showed increment of phosphatidylcholine content and decrement of sphingomyelin content, although plasma lipids were essentially normal. Influx and efflux of sodium through the red cell membrane were both increased. Splenectomy was performed without effect on one patient and the mother of other patients.

Adult↗
PubMed1996

[Sickle cell anemia].

Sickle cell anemia is a disease having both hemolytic anemia and vasocclusive phenomenon. The mutant gene product (hemoglobin S[HbS], beta 6glu-->val) has the tendency to polymerize at low oxygen tension and cause the sickling phenomenon. This has been assumed to be the dominant factor of the pathophysiology in the sickle cell anemia. In addition, unstable HbS, disturbed cation homeostasis and adhesiveness of sickle cell to the endothelium are sufficient to impact on clinical features. The unstable HbS generates oxidant, induces iron decompartmentalization and cellular dehydration, resulting in abnormal microrheology, endothelial adhesivity, phospholipids destabilization and protein defects. These membrane defects and HbS polymerization (RBC sickling) play the important role on the pathophysiology (hemolytic anemia and vasocclusion) in sickle cell anemia.

Anemia, Sickle Cell↗
PubMed1996

[Bone marrow transplantation versus maintenance chemotherapy for adult acute leukemia in first remission].

We compared the outcome of bone marrow transplantation (BMT) with that of maintenance chemotherapy for adults with acute leukemia who achieved first remission in Japanese Red Cross Nagoya First Hospital. From 1976 to 1993, 17 patients with acute myelogenous leukemia (AML) and 10 patients with acute lymphoblastic leukemia (ALL) received allogeneic BMT from HLA genotypically identical siblings in first remission, 4 patients with ALL undertook purged autologous BMT using monoclonal antibody and complement, and 55 patients with AML and 27 patients with ALL were treated with maintenance chemotherapy. The estimated 6-year disease free survival (DFS) of AML patients was significantly higher in the BMT group than in the chemotherapy group (77.3% vs 42.6%; p < 0.01). For ALL patients, the estimated 6-year DFS was 72.5% in the allo-BMT group and 100% for the auto-BMT group, but no patient was disease free more than 2 years in the chemotherapy group (p < 0.0001). We conclude that BMT after several courses of consolidation chemotherapy is the optimal treatment of choice in patients with AML and ALL in first remission. A prospective study is needed to confirm the efficacy of BMT after intensive consolidation chemotherapy.

Adolescent↗
PubMed1996

Rise time and amplitude of visually elicited EPSPs of tectal neurons of the frog.

Visually elicited activities in response to on-off of diffuse light and moving patterns were recorded from tectal neurons of the frog by means of perforated in vivo whole cell recording technique. Rise time histograms of EPSPs had a single or multiple peaks. Comparing the histogram patterns for each stimulus, retinal fiber classes and positions of synapses on the dendrites could be correlated. In most cells, R3 fibers made synapses on proximal dendrites, whereas R1/R2 fibers on distal dendrites, which was consistent with anatomical findings. Preliminary quantum analysis of EPSP amplitudes was performed by fitting the histograms with a binomial curve and parameters q and n were determined. The result showed that the number n of synapses on distal dendrites is larger than those on proximal dendrites.

Animals↗
PubMed1995

Fascia-vascularized vs. muscle-vascularized prefabricated flaps using tissue expanders: an experimental study in a rat model.

The aim of this study was to compare the applicability and viability of a fascia-vascularized pedicle (FVP) with those of a muscle-vascularized pedicle (MVP) in the prefabrication of a secondary vascularized pedicle flap using a tissue expander. Experiments were carried out in 32 male Wistar rats. The animals were divided into two groups--Group 1 (n = 10), using a skeletonized pedicle of the right saphenous artery, vein, and nerve with a segment of 8 x 10 mm fascia on its distal end (FVP group); and Group 2 (n = 10), using a 3-mm perivascular cuff of muscle with a segment of 8 x 10 mm fascia and gracilis muscle on its distal end (MVP group). The experiments demonstrated that there was a larger area of flap survival in the expanded muscle-vascularized pedicle flaps (96.6 +/- 3.6 percent) than that found in the expanded fascia-vascularized pedicle flaps (83.0 +/- 14.4 percent) in this rat model (p < 0.005). The microangiography of the flaps showed increased vascularity of the muscle cuff at the end of the vascular pedicle in Group 2.

Angiography↗
PubMed1995

Two-dimensional analysis of hemodynamic changes in axial and random pattern flaps.

The present study was performed to evaluate the time course of hemodynamic change in axial and random pattern flaps two-dimensionally. The axial pattern flap, including the central auricular artery and vein, and the random pattern flap without these vessels were created in the auricles of the rabbit. The blood flow of these flaps was investigated and assessed using laserflowgraphy, which provides a two-dimensional analysis of microcirculation. In the axial pattern flap, a gradient of blood flow toward the short axis of the flap and decreased blood flow in the surrounding area were noticed immediately after operation. The hemodynamic changes became less marked with time. In the random pattern flap, a gradient of blood flow toward the long axis of the flap was noticed around 6 hr after operation and the blood flow in the surrounding area increased throughout the investigations.

Animals↗
PubMed1995

"Boomerang" rectus abdominis musculocutaneous free flap in head and neck reconstruction.

Immediate head and neck reconstruction after cancer resection using the "boomerang" rectus abdominis musculocutaneous (RAM) free flap was performed in 13 patients over the past 2 years. The skin paddle of the flap is designed as a boomerang shape based on the anatomical construction of the dominant perforators from the inferior epigastric vascular system. A versatile technique of the boomerang RAM flap provides effective use for reconstruction of the complex defects at the skull base, orbital, nasal cavity, paranasal sinuses, oropharynx, palate, buccal mucosa, tongue, floor of mouth, and neck. It also allows a reconstructive surgical team to elevate the flap simultaneously with a head and neck surgical team before the size and location of the defect are exactly determined and greatly reduces operating time. This flap will be a routine technique for immediate head and neck reconstruction after cancer resection.

Abdominal Muscles↗
PubMed1995

The effects of lipo-prostaglandin E1 on axial pattern flaps in rabbits.

The effects of lipo-prostaglandin E1 (lipo-PGE1), lipid microspheres containing PGE1, on axial pattern flaps were examined using 12 x 20 cm axial pattern flaps based on the right superficial inferior epigastric vessels on the abdomens of rabbits. The surviving area of the skin flap in the lipo-PGE1 group (0.197 +/- 14.1 cm2; n = 10) was significantly increased (p < 0.02) compared with the saline control group (110.4 +/- 5.5 cm2; n = 10). Changes in pedicle blood flow after lipo-PGE1 administration were determined using an ultrasonic pulsed Doppler flowmeter (n = 5). Blood flow in the artery was increased immediately after administration, and it was maintained for 40 minutes. The surface blood flow at the caudal end of the flap on the nonpedicle side, where it was poor, was measured using laserflowgraphy. Blood flow in the skin flap surface was improved 5 to 15 minutes after lipo-PGE1 administration, and it was maintained for as long as 60 minutes. Venous occlusion of the skin flap was also improved (n = 3). In conclusion, lipo-PGE1 increased the blood flow in the axial pattern flaps, resulting in significant enlargement of the surviving skin flap area.

Alprostadil↗
PubMed1995

An anatomic study for a vascularized bone flap of femur.

The anatomy of the nutrient vessels of the shaft of the human femur was studied in a series of 20 dissections in 10 preserved cadavers and 8 clinical stereoscopic angiograms of the femoral region in 7 adult patients. The number and external diameter of the nutrient artery and the distance of the nutrient vessel from the greater trochanter and the origin of the profunda femoris artery were measured. A single or two nutrient vessels of large caliber originated from the perforating branches of the profunda femoris artery constantly entered at the points along the linea aspera of the femur. The average distance of the nutrient artery from the point where the profunda femoris artery arose from the femoral trunk, which means length of the vascular pedicle of a bone flap, was over 11 cm. We foresee the future use of a vascularized bone flap of the femur combined with the surrounding muscle and the lateral thigh fasciocutaneous flap based on the profunda femoris vascular system.

Aged↗
PubMed1995

An anatomic study for the rectus abdominis myocutaneous flap combined with a vascularized rib.

The anatomy of the vascular connections between the eighth intercostal vessels and the deep epigastric vessels was studied in a series of 20 dissections in 10 preserved cadavers to develop the rectus abdominis myocutaneous flap combined with a vascularized rib. The distance between the point where the eighth intercostal vessels attached to the costal margin and the xiphoid process and the arcuate line, which become a good guide for design of the flap, was measured. The average length of the vascular pedicle of a vascularized rib was over 10 cm. Possible clinical uses of this compound flap for reconstruction of a composite maxillary or mandibular defect are described.

Abdominal Muscles↗
PubMed1995

Penetration of flomoxef into human maxillary and mandibular bones.

Penetration of flomoxef into the maxillary and mandibular bones was assayed clinically to provide data about its usefulness for the prevention of postoperative infection after maxillofacial surgery. Twenty-one patients undergoing maxillofacial surgery at our department were given flomoxef 2 g dissolved in 20 ml of physiological saline intravenously over 3 minutes during operation, and the serum, maxillary and mandibular concentrations were measured 1, 3, and 6 hours after injection by the band culture method using Escherichia coli 7437 as the indicator strain. The mean concentrations were 53.4, 16.1, and 2.6 micrograms/ml, respectively, in the serum, 17.6, 7.8, and 1.0 micrograms/g in maxillary bone, and 16.4, 4.2, and 0.9 micrograms/g in mandibular bone. The mean bone:serum ratios at 1, 3, and 6 hours were 33.0%, 48.2%, and 36.8%, respectively, for maxillary bone, and 30.7%, 26.2%, and 35.7% for mandibular bone. When compared with previously reported data on the bone:serum ratios in jaw of various other intravenous antibiotics, our results show that penetration of flomoxef into maxillary and mandibular bone is extremely high. As all the intramaxillary and intramandibular concentrations exceed its MIC80 values against clinical isolates of bacteria frequently isolated in cases of infection in the oral and maxillofacial region, it is apparent that one intravenous shot of flomoxef 2 g allows penetration of the drug into the maxillary and mandibular bones at effective concentrations. Flomoxef is therefore potentially useful for the prevention and treatment of infections in the oral and maxillofacial region, as it has excellent penetration into the maxillary and mandibular bones.

Adolescent↗
PubMed1994

Enhanced expression of multiple forms of VEGF is associated with spontaneous immortalization of murine fibroblasts.

The mechanism(s) involved in immortalization that constitute the first step during malignant transformation has been the subject of our interest. By the use of spontaneously immortalized mouse embryonic fibroblasts we have earlier identified two stages of immortalization which are characterized by growth characteristics of the cells, their conditioned medium and the protein markers such as p53, p81 and mortalin (Kaul et al. (1994) Biochim. Biophys. Acta, in press). The present study was planned to purify the mitogenic factors from the conditioned medium of stage II cells. Sequential purification by chromatography followed by peptide sequencing has characterized one of these as vascular endothelial growth factor (VEGF). Further analysis by RT-PCR suggests that the spontaneously immortalized stage II fibroblasts have enhanced synthesis and secretion of VEGF as compared to their mortal parent cells. Expression of a novel 304 bp long form of VEGF is identified in immortal fibroblasts in addition to the three known alternatively spliced forms. The study points to the involvement of VEGF function during spontaneous immortalization of mouse embryonic fibroblasts.

Alternative Splicing↗
PubMed1994

Identification of genetic events involved in early steps of immortalization of mouse fibroblasts.

The spontaneously immortalized early passaged fibroblasts from three different strains of mouse are observed to represent two distinct stages of immortalization. The cells at stage I are characterized by slow growth rate, contact inhibition and requisition of serum factors for their growth and proliferation. Stage II cells are marked by fast, multilayer growth that is independent of serum supplementation in growth medium and by the elevated levels of the two marker proteins, i.e., p53 and p81. The change from cytosolic distribution of mortalin, a senescence inducing protein (J. Biol. Chem. (1993) 268, 6615-6621; 22239-22242) to the perinuclear locale is detected as an early event during cellular immortalization. Furthermore, the distinct stages could be characterized by thermal analysis of intact cells, that to the best of our knowledge is employed for the first time for the analysis of cellular mortal and immortal phenotypes. The study characterizes at least two distinct end points in rodent transformation suggesting that there are multiple routes to immortalization.

Animals↗