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Biomedical subjects

A Kishida

Publications and source records attributed to A Kishida.

At least 37 records · Page 2Linked to original sources
PubMed1999

Handlebar hernia with intra-abdominal extraluminal air presenting as a novel form of traumatic abdominal wall hernia: report of a case.

An 18-year-old male was admitted to our Emergency Department with a traumatic abdominal wall hernia (TAWH) of the left lower quadrant (LLQ) after suffering hypogastric blunt injury and urogenital lacerations in a motorcycle accident. Upright chest X-ray showed a small amount of right infradiaphragmatic free air, and a computed tomographic (CT) scan demonstrated an abdominal wall hernia. At surgery, no impairment was found in the digestive tract, and an abdominal herniorrhaphy was performed. It is suggested that the free air had passed through a connection between the scrotal laceration and the contralateral abdominal defect via the subcutaneous space and was palpated as emphysema. This is a new type of TAWH, which suggests that blunt abdominal trauma may result in negative pressure in the subcutaneous and peritoneal cavity, and this could reflect the pathophysiology of TAWH.

Abdominal Muscles↗
PubMed1999

Protective role of nitric oxide in ischemia and reperfusion injury of the liver.

BACKGROUND: The suppressed production of nitric oxide (NO), associated with endothelial dysfunction, is thought to be a cause of ischemia and reperfusion injury of the liver. But findings of the salutary effects of NO enhancement on such injury have been conflicting. In this study, we tested our hypothesis that NO enhancement would attenuate ischemic liver injury. For this purpose, an NO precursor, L-arginine, and a novel NO donor, FK409, were applied to a 2-hour total hepatic vascular exclusion model in dogs. STUDY DESIGN: L-arginine was administered IV at a dose of 100 mg/kg twice (n = 5), while 300 mg/kg twice of FK409 was infused continuously into the portal vein (n = 5). The drugs were given to the animals for 30 and 60 minutes before and after ischemia, respectively. Non-treated animals were used as the control (n = 10). Two-week survival, systemic and hepatic hemodynamics indices, liver function tests, energy metabolism, and histopathology were analyzed. RESULTS: Both treatments comparably augmented hepatic tissue blood flow, decreased liver enzyme release, and increased high-energy phosphate restoration during the reperfusion period, all of which contributed to rescuing all of the treated animals from the 2-hour total hepatic ischemia. In contrast, ischemia caused 70% mortality in the control group. Histologically, structural abnormality and neutrophil infiltration were markedly attenuated by the treatments. Systemic hypotension was observed in the animals treated with FK409, however. CONCLUSIONS: Our data demonstrate that NO enhancement alleviates the liver injury caused by ischemia and reperfusion. The supplementation of L-arginine, rather than FK409, is considered more applicable to clinical use because of the absence of systemic adverse effects.

Adenine Nucleotides↗
PubMed1999

A study on hydroxyapatite formation on/in the hydroxyl groups-bearing nonionic hydrogels.

Using the biomimetic method, we formed a hydroxyapatite (HAp) layer on/in certain types of nonionic hydrogels that contain hydroxyl groups. The hydrogels used were poly(vinyl alcohol) (PVA), poly(2-hydroxyethyl methacrylate) (PHEMA), poly(glucosyloxyethyl methacrylate) (PGEMA), and agarose. Under an optical microscope, we observed a thin, continuous HAp layer on the top surface of the PVA, PHEMA, and PGEMA gels. On the other hand, we only observed an intermittent HAp layer on the surface of the agarose gel. The swelling ratio and the bound water content of these hydrogels were measured as an essential character in HAp formation. There was some relation among the HAp formation, the swelling ratios, and the bound water content.

Calcinosis↗
PubMed1999

Apatite formation on/in hydrogel matrices using an alternate soaking process: II. Effect of swelling ratios of poly(vinyl alcohol) hydrogel matrices on apatite formation.

In our previous study, we reported a novel method of apatite formation on/in a three-dimensional hydrogel matrix. Using this method, bone-like apatite could be formed on/in the hydrogel matrix under normal conditions in vitro. A poly(vinyl alcohol) (PVA) gel was used as a model matrix. The method consists of two steps: first, water is transformed in a PVA gel with a CaCl2/Tris-HCl aqueous solution (pH 7.4) and second, the gel is soaked in a Na2HPO4 aqueous solution. In the present study, we report a detailed study of the effects of the swelling ratios of PVA gels on apatite formation. Cross-sectional observations and gravimetric measurements of PVA gels with various swelling ratios were done. The amount of apatite formed on/in PVA gels increased almost linearly with an increase in the reaction cycles. The rates of apatite formation on/in PVA gels largely depended on the swelling ratios, which were approximately 0.48, 0.61, 1.28, and 1.55 mg per cycle for swelling ratios of 4.1, 10.4, 16.8, and 30.1, respectively. The apatite content in PVA-apatite composites that was obtained by this method also increased with an increase of the reaction cycles. After six reaction cycles, a PVA gel with a high swelling ratio contains approximately 70 wt% of formed apatite in the composite. On the other hand, a gel with a low swelling ratio contains about 15 wt% of formed apatite in the composite. Cross-sectional views of the PVA gels after each cycle showed that apatite crystals were formed, not only on the surface of the gel but also within it after fifteen reaction cycles. The hydrogel-apatite composites that were obtained using an alternative soaking process will be useful as not only bone substitute materials but also as soft tissue adhesive materials.

Apatites↗
PubMed1999

Ca-adsorption and apatite deposition on silk fabrics modified with phosphate polymer chains.

Silk fabric was modified with polymethacryloyloxyethylphosphate (pMOEP) by graft copolymerization. Ca-adsorption onto pMOEP-grafted silk fabric was significantly enhanced compared to that onto original silk fabric. SEM observation indicated that some crystallites were deposited on the pMOEP-grafted silk fabric after 1 week of immersion in simulated body fluid, whereas no change occurred on the surface of the original silk fabric. X-ray diffraction showed that this crystallite contained hydroxyapatite. These results indicate that pMOEP-grafted silk fabric induce hydroxyapatite formation more effectively than the original silk fabric.

Adsorption↗
PubMed1999

Apatite formation on/in hydrogel matrices using an alternate soaking process (III): effect of physico-chemical factors on apatite formation on/in poly(vinyl alcohol) hydrogel matrices.

The aim of this study is to clarify the physico-chemical factors which influence apatite formation on/in a hydrogel during a novel alternate soaking process. A poly(vinyl alcohol) (PVA) gel was used as a model matrix. The amount of apatite formed on/in PVA gels decreased with an increase in the reaction temperature during the same reaction cycles. This suggested that the equilibrium swelling ratios decreased with increasing reaction temperatures; that is, the diffusion of calcium and phosphate ions reduced at high reaction temperature. However, the crystallinity of apatite formed on/in PVA gels was greater at higher reaction temperatures. The amount of apatite formed on/in PVA gels increased with an increase in the calcium and phosphate solution concentrations, and increased by shaking at the first three reaction cycles. A few influences could be observed when the solution volume was changed, however, the soaking order was not effective in this study. These results indicate that the amount of apatite formation on/in PVA gels can be controlled by changing the reaction temperature and the Ca- and P-solution concentrations, and that the crystallinity of apatite can be also changed by controlling the reaction temperatures.

Apatites↗
PubMed1999

[Application of microvascular surgery in reconstructive digestive tract surgery].

In our institutes, microvascular surgery has been effectively used in reconstructive digestive tract surgery, including esophageal reconstruction and hepatic arterial reconstruction. Free jejunal transfer combined with a gastric pedicle or microvascularly augmented elongated gastric pedicle has been utilized for total esophageal reconstruction. A microvascularly augmented jejunal pedicle or colonic pedicle has been applied in thoracic esophageal reconstructive cases with gastrectomy. Moreover, microvascular surgery has been performed in the reconstruction of the hepatic arterial system in the surgical treatment of pancreatic or bile duct cancer and living related-donor liver transplantation. Some pitfalls in selection of the recipient vessels and handling the intraperitoneal vessels for microvascular anastomosis are also described. Although microvascular surgery has been carried out by plastic and reconstructive surgeons in a team surgical approach, revisions in the medical educational system to create a new-type of surgeon with practical skills and clinical experience in both digestive tract and microvascular surgery will be required in future.

Aged↗
PubMed1998

Preparation of a novel functional hydrogel consisting of sulfated glucoside-bearing polymer: activation of basic fibroblast growth factor.

Sulfated poly(glucosyloxyethyl methacrylate) [poly(GEMA)-sulfate] and its hydrogel were synthesized and evaluated to develop novel tissue regeneration assist devices. The poly(GEMA)-sulfate hydrogel was obtained by gamma-ray irradiation. Basic fibroblast growth factor (bFGF) was expected to be subsequently incorporated with hydrogel matrices and activated or released from the matrices. A sustained release of bFGF from the poly(GEMA)-sulfate hydrogel was not realized; however, bFGF from poly(GEMA)-sulfate hydrogel was effectively activated. Poly(GEMA)-sulfate hydrogels are thought to be potential component materials for a tissue engineering matrix.

Cell Adhesion↗
PubMed1998

Base-specific separation of oligodeoxynucleotides by capillary affinity gel electrophoresis.

Capillary affinity gel electrophoresis was applied to sequence-specific and base composition-specific recognition of oligodeoxynucleotides, utilizing the formation of heteroduplexes between a nucleic acid analogue immobilized into the capillary gel and soluble oligodeoxynucleotides with different sequences. Capillary affinity gel electrophoresis using capillaries filled with a conjugated gel of polyacrylamide and a synthetic nucleic acid analogue [poly(9-vinyladenine)] was effective for the selective separation of hexathymidylic acid from a mixture of four homopolymers of A6, C6, G6, and T6 and for the complete resolution of five heteropolymers of hexadeoxynucleotides (TAAAAA, TTAAAA, TTTAAA, TTTTAA, TTTTTA). We also demonstrated that capillary affinity gel electrophoresis was useful for the selective and the sensitive sequence-specific recognition of sequence isomers of DNA (TTTTAA, TTTTAAT, TTTATA, and TTTTAA).

Affinity Labels↗
PubMed1998

The application of radio-opaque markers prior to ileostomy in an infant with chronic intestinal pseudo-obstruction: report of a case.

We report the case of a 6-month-old boy who developed chronic intestinal pseudo-obstruction soon after birth. A rectal biopsy demonstrated immaturity of the neuronal cells in the enteral ganglion. His clinical course was stressful, with remission and exacerbation despite conservative treatment with daily bowel irrigation, prokinetic agents, and parenteral nutrition. Since the infant developed serious enterocolitis associated with the increased severity of his bowel obstruction, and no substantial gain in body weight was observed, a loop-ileostomy was performed based on X-ray findings with radio-opaque markers, which were employed to evaluate the whole gut transit time. The radio-opaque markers proved extremely useful for determining which loop of the ileum should be utilized for the ileostomy.

Barium Sulfate↗
PubMed1998

Manual reduction with the index finger for infantile intussusception. A modification of Hutchinson's maneuver.

Manual reduction with the index finger (modified Hutchinson's maneuver) enabling simple and safe manual reduction of infantile intussusception is described. The procedure was used in four patients, two boys and two girls, ranging in age from 2 to 15 months, as greater than normal compression was necessary and/or serosal splitting occurred during conventional reduction. The technique is as follows: in addition to the proximal bowel compression with Hutchinson's maneuver, the surgeon inserts his index finger into the intussusceptum via its neck. The finger enables the surgeon to sound a wider space between the intussusceptum and intussuscipiens, which is most likely to be responsive to bowel compression. Although the intussusceptions in the four patients were categorized as ileo-ileo-colic (three cases) and ileo-ileal (one case) types, this manual reduction technique was successful in all cases, no bowel rupture occurred, and hospitalization was no longer than with the conventional procedure. We conclude that this modified Hutchinson's maneuver may contribute to successful surgical reduction of infantile intussusception.

Female↗
PubMed1997

Efficacy of prostaglandin I2 analog on liver grafts subjected to 30 minutes of warm ischemia.

Due to the fact that no effective conditioning agent for hemodynamically unstable donors exists, the number of suitable donors is limited. The efficacy of OP-41483, a stable analog of prostaglandin I2, as a conditioning agent of the liver was investigated in this study using pigs. OP-41483 was administered via the portal tributary for 10 min before 30 min of warm ischemia. Graft livers were procured after perfusion with OP-41483 in cold normal saline, then flushed with OP-41483 in Euro-Collins solution and placed in cold storage prior to orthotopic transplantation. OP-41483 was also administered intraportally for 120 min after reperfusion. Biochemical and histological studies, and survival rates were compared with a control group not given OP-41483 in an otherwise similar experimental protocol. The graft function recovered better in the OP group than in the control group, shown by the lactate values and lactate-to-pyruvate ratios. The marked congestion noted in the parenchyma of the control group livers was minimal in the OP group, verifying the microcirculatory effect of prostaglandin I2 by its vasodilatory and antithrombotic actions. These findings suggest that OP-41483 has some protective effect as a conditioning agent in liver transplantation, with timing of administration being crucial.

Alanine Transaminase↗
PubMed1997

Three-dimensional helical computed tomography with intravenous cholangiography for sclerosing cholangitis manifested as postcholecystectomy symptom.

A 46-year-old woman who had upper abdominal pain 10 years after cholecystectomy, and who had incidental sclerosing cholangitis (SC), was investigated by three-dimensional helical computed tomographic (3-DHCT) cholangiography with contrast medium, because endoscopic retrograde cholangiography (ERC) was unsuccessful and a second ERC was not permitted by the patient. The cholangiogram demonstrated annular strictures of the bilateral hepatic duct at the confluence of the common hepatic duct, and dilatation of the left intrahepatic biliary duct. Although we could not clarify the cause of the biliary tract deformity at the time of the 3-DHCT, the tentative diagnosis of postcholecystectomy deformity of the biliary tree led to successful treatment by right liver lobectomy and hepaticojejunostomy. Histologic findings were compatible with SC. From this experience and the literature, we suggest that 3-DHCT cholangiography with contrast medium can contribute to the preoperative diagnosis of morphological changes in the biliary tree in patients with postcholecystectomy symptoms.

Cholangiography↗
PubMed1997

Evaluation of biological responses to polymeric biomaterials by RT-PCR analysis. II: Study of HSP 70 mRNA expression.

In order to investigate how cells recognize biomaterials, mRNA that was expressed in attached HeLa S3 cells on various substrates was evaluated. As culture substrates, cellulose, ethylene-vinyl alcohol copolymer (EVAL), nylon, tissue culture polystyrene (TCPS), high-density polyethylene (PE), silicone rubber, and tetrafluoroethylene-hexafluoropropylene copolymer (6F) were used. HeLa S3 cells were cultured on these substrates for 24 h. The expressed HSP 70s mRNA was then isolated and detected using the RT-PCR method. As a result, the expression of HSP 70B mRNA was largely induced in cells that adhered to hydrophilic surfaces. On the other hand, on hydrophobic surfaces, the HSP 70B mRNA expression was low. It is concluded that HSP 70B mRNA expression is sensitive to differences in the hydrophilicity-hydrophobicity of the substrates.

Biocompatible Materials↗