Biomedical subjects

Tetsuya Yamamoto

Publications and source records attributed to Tetsuya Yamamoto.

At least 37 records · Page 2Linked to original sources

PubMed2006

Prevalence and causes of low vision and blindness in a Japanese adult population: the Tajimi Study.

OBJECTIVE: To determine the prevalence and causes of low vision and blindness in a Japanese adult population. DESIGN: Population-based cross-sectional study. PARTICIPANTS: Randomly selected residents (n = 3870) of Tajimi City, Japan, who were 40 years of age or older. METHODS: Of the 3021 study participants (78.1% of 3870 eligible persons), 2977 (76.9%) underwent a complete ophthalmologic examination including measurement of the best-corrected visual acuity (BCVA) with full subjective refraction using a Landolt ring chart at 5 m. Age- and gender-specific prevalence rates of low vision and blindness were estimated and causes were identified. MAIN OUTCOME MEASURES: Low vision and blindness were defined as BCVA in the better eye worse than 20/60 to a lower limit of 20/400 and worse than 20/400, respectively (World Health Organization [WHO] criteria) and worse than 20/40 but better than 20/200 and 20/200 or worse, respectively (United States criteria). RESULTS: The overall prevalence of blindness according to the WHO or U.S. criteria was 0.14% (n = 4; 95% confidence interval [CI], 0.06-0.32). The primary causes were optic atrophy, myopic macular degeneration, retinitis pigmentosa, and uveitis. The overall prevalence of low vision according to the WHO criteria was 0.39% (95% CI, 0.18%-0.60%) and according to the U.S. criteria was 0.98% (95% CI, 0.66%-1.30%), which was significantly greater in women and in the older half of the participants than in the younger half (P = 0.0079 and <0.0001, respectively). The leading causes of low vision in descending order were cataract followed by glaucoma, and those of monocular blindness were myopic macular degeneration, glaucoma, and trauma. CONCLUSIONS: The prevalence of low vision and blindness in Japanese adults was one of the lowest among those reported. The major causes of low vision were cataract and glaucoma, and the leading cause of monocular blindness was myopic macular degeneration.

Aged↗

PubMed2006

A new calcium channel antagonist, lomerizine, alleviates secondary retinal ganglion cell death after optic nerve injury in the rat.

PURPOSE: We investigated whether lomerizine, a new diphenylmethylpiperazine calcium channel blocker, exerted a neuroprotective effect on axonal or retinal damage induced by optic nerve injury in the rat. METHODS: A partial crush lesion was inflicted unilaterally on the optic nerve, 2 mm behind the globe, in adult Wistar albino rats. Animals were treated with the vehicle, 10 or 30 mg/kg lomerizine. Each solution was given orally twice daily for 4 weeks. One week before euthanization, Fluoro-Gold (FG) was injected into both superior colliculi to retrogradely label surviving retinal ganglion cells (RGCs). Approximately 1 month after the optic nerve injury, the retinal damage was assessed morphologically, and the optic nerve axons surrounding the initial lesion were examined histologically. RESULTS: The mean RGC density in the control group decreased to 65.9 +/- 1.32% of the contralateral eye, whereas the systemic application of 10 or 30 mg/kg of lomerizine significantly enhanced the RGC survival to 88.1 +/- 0.38% and 89.8 +/- 0.28%, respectively. Histological examination of damaged axons revealed no significant enhancement of the density or total number of axons of the retinal ganglion cells in the lomerizine-treated group. The crush force we employed caused no significant morphological differences in the retinal layers between the sham-operated animals and the animals from the experimental groups. CONCLUSIONS: Our findings suggest that lomerizine alleviates secondary degeneration of RGCs induced by an optic nerve crush injury in the rat, presumably by improving the impaired axoplasmic flow.

Animals↗

PubMed2006

Incidence of disc hemorrhages in open-angle glaucoma before and after trabeculectomy.

PURPOSE: To investigate the effects of reduction of intraocular pressure (IOP) by surgical intervention on the frequency of disc hemorrhages in eyes with primary open-angle glaucoma (POAG) and normal-tension glaucoma (NTG). DESIGN: Retrospective study. METHODS: We studied 99 eyes of 99 patients with POAG and 50 eyes of 50 patients with NTG, who underwent trabeculectomy with adjunctive mitomycin C (MMC) and were followed regularly at 1 to 3-month intervals at the Glaucoma Service of Gifu University Hospital. We applied Kaplan-Meier life-table analysis for the detection of disc hemorrhages before and after trabeculectomy. RESULTS: Trabeculectomy significantly reduced IOP (in POAG: 19.6 +/- 4.4 down to 11.1 +/- 4.2 mm Hg; in NTG: 15.3 +/- 1.5 down to 11.3 +/- 4.5 mm Hg; mean +/- SD). Life-table analysis revealed that the final cumulative probability of detecting a disc hemorrhage after surgery in POAG was 5.5 +/- 2.2% (calculated probability +/- SE) and was significantly lower than that (33.4 +/- 7.8%) before surgery (P < 0.0001, log-rank test). Likewise, the final probability after surgery in NTG was 23.1 +/- 6.3% and was significantly lower than that (42.1 +/- 8.8%) before surgery (P = 0.0063, log-rank test). CONCLUSIONS: IOP reduction via surgical intervention significantly decreases the frequency of disc hemorrhages in open-angle glaucoma patients.

Adult↗

PubMed2006

Metallothionein, an endogenous antioxidant, protects against retinal neuron damage in mice.

PURPOSE: To clarify the functional role of metallothionein (MT) in retinal damage in mice deficient in both MT-I and -II (MT-I/-II-deficient mice [C57BL/6J background]) and wild-type (C57BL/6J) mice and MT induction (zinc sulfate [ZnSO4] and 1alpha, 25-dihydroxyvitamin D3 [Vit. D3]). METHODS: Retinal, cell damage was induced by intravitreous injection of N-methyl-D-aspartate (NMDA; 40 nmol/eye). Retinal MT-I, -II, and -III mRNA expression was monitored by real-time reverse-transcription-PCR of total retinal RNA from eyes injected or not injected with NMDA. In wild-type mice, MT-I and -II immunohistochemistry was performed (with antibody that recognizes both proteins) 12 and 24 hours after intravitreous NMDA injection. To examine the involvement of induced retinal MT, ZnSO4 (10 nmol/eye) or Vit. D3 (0.2 or 2 ng/eye) was intravitreously injected 24 hours before NMDA injection in wild-type or MT-I/-II-deficient mice, and ganglion cell layer (GCL) cell loss and inner plexiform layer (IPL) thinning were evaluated 7 days after the NMDA injection. The protective effect of Vit. D3 was assessed against the RGC-5 cell death induced by oxidative stress (using buthionine sulfoximine [BSO] to deplete glutathione in combination with glutamate to inhibit cystine uptake). RESULTS: In wild-type mice, MT-II mRNA expression was time-dependently elevated by NMDA (5.9 and 7.4 times versus the nontreated control at 4 and 12 hours, respectively, after injection), with the normal level being regained within 24 hours. In contrast, MT-I and -III showed persistent decreases (to <50% control) from 4 to 24 hours. In wild-type mice, MT-like immunoreactivity was increased in the inner retina (GCL and IPL) 12 and 24 hours after NMDA injection. At 7 days after NMDA injection in MT-I/-II-deficient mice (versus wild-type mice), GCL cell loss was increased, but IPL thickness was not different. Pretreatment with ZnSO4 or Vit. D3 increased inner retinal MT-like immunoreactivity 24 hours after NMDA injection and significantly attenuated NMDA-induced GCL cell loss in wild-type mice, but ZnSO4 pretreatment did not protect against such cell loss in MT-I/-II-deficient mice. In vitro, Vit. D3 pretreatment (100 nM) reduced BSO+glutamate-induced RGC-5 cell death. CONCLUSIONS: These findings suggest that MT, especially MT-II, protects against retinal neuron damage, by acting as an endogenous antioxidant.

Animals↗

PubMed2005

Growth mechanism of soap-free polymerization of styrene investigated by AFM.

To clarify the growth mechanism of polystyrene (PSL) particles in the soap-free polymerization, characteristics of not only particles but also polymeric materials floating in the bulk were investigated on the molecular scale by using atomic force microscope (AFM), where a cationic initiator V-50 is used to make the formed polymeric materials transfer on the mica plate in sampling. Our main attention here is to know the reason why the particle size increases with increasing initiator concentration in the production of PSL particles. The following are found. (1) As far as the initiators and monomers remain in the bulk solution, the polymeric materials are born in the bulk continuously, because of the slow decomposition rate of initiators. (2) The growth of particles at the early stage of t(r) > or = 0.75 h is considered to be attributable mainly to the particle swelling by absorbing monomers from the bulk. The rapid growth at the intermediate stage is due to the deposition of polymeric materials in the bulk on the particle surface and their simultaneous swelling by monomers in the bulk. (3) The reason why the particle size increases with increasing concentration of initiator is that the growth process is controlled by the deposition rate of polymeric materials in the bulk whose amount increases with the initiator concentration. (4) The particle size and the smoothness of particle surface depend on the relative concentration of initiators and monomers remained.

Journal Article↗

PubMed2005

Antimicrobial peptides enhance the candidacidal activity of antifungal drugs by promoting the efflux of ATP from Candida cells.

OBJECTIVES: To establish a novel strategy of fungal infection control. METHODS: We examined the influences of antimicrobial peptides including a synthesized short lactoferrin peptide (FKCRRWQWRM, Peptide 2; Pep2) on the synthesis of Candida cell wall polysaccharides, ergosterol synthesis, membrane permeability and the efflux of ATP. RESULTS: Colony formation of Candida albicans was synergistically suppressed by a combination of low concentrations of each drug and peptide. All peptides and amphotericin B, but not itraconazole, revealed weak inhibitory activities against ergosterol synthesis and the peptides weakly suppressed the synthesis of Candida cell wall components, glucan, mannan and chitin. Cell membrane permeability was not only increased by these peptides but also clearly increased by both amphotericin B and itraconazole. ATP efflux was however up-regulated by low concentrations of the peptides, especially by Pep2 and Hst5, although both antifungal drugs did not exert any influence on ATP efflux. The expression of the Candida drug resistance genes 1 and 2 (CDR1 and CDR2) was increased by both drugs, but this increase was suppressed by each peptide. In addition, larger amounts of amphotericin B and itraconazole remained in Candida cells in the presence of Pep2 or Hst5 due to the lower excretion. The effects of both peptides on ATP efflux and increase of intercellular amphotericin B and itraconazole were blocked by anion channel inhibitors 4,4'-diisothiocyanatestilbene-2, 2'-disulphonic acid and 5-nitro-2-(3-phenylpropylamino) benzoic acid. CONCLUSIONS: The examined peptides, especially Pep2 and Hst5, enhance the candidacidal activity of antifungal drugs by promoting anion channel-associated ATP efflux from Candida cells and decreasing efflux of the drugs, which could be useful clinical applications.

ATP-Binding Cassette Transporters↗

PubMed2005

Palladium-catalyzed addition of arylboronic acids to aldehydes.

[reaction: see text] Arylboronic acids react with aldehydes in the presence of a base and a catalytic amount of a palladium(0) complex with chloroform, affording the corresponding secondary alcohols in good yields. General palladium complexes have no catalytic activity without chloroform. Chloroform is essential for this reaction, and palladium complex that was prepared from Pd(PPh3)4 with CHCl3 showed good catalytic acitivity as well.

Journal Article↗

PubMed2005

Molecular-scale observation of the surface of polystyrene particles by AFM.

The surface morphology of polystyrene particles prepared by soap-free emulsion polymerization was observed in situ using the tapping mode of an atomic force microscope (AFM). Here, the use of a cationic initiator enabled us to synthesize positively charged polystyrene, which then adsorbed electrostatically onto the negatively charged mica plate with molecular-scale smoothness. The following was found from AFM measurements in water. The surface of polystyrene particles changed from smooth to rough as the polymerization proceeded in the experimental condition, where the bulk generated tiny particles continuously, because of the heterocoagulation in the growth process between the newborn and tiny particles and the existing particles. However, it is easy to prepare the particles with smooth surfaces on the condition of rich monomers because the monomers in the bulk dissolve the polymers which form the surface morphology to be deformable and reduce the interfacial area.

Adsorption↗

PubMed2005

Inhibition of autoantigen expression by (-)-epigallocatechin-3-gallate (the major constituent of green tea) in normal human cells.

Autoimmune disorders, characterized by inflammation and apoptosis of target cells leading to tissue destruction, are mediated in part by autoantibodies against normal cellular components (autoantigens) that may be overexpressed. For example, antibodies against the autoantigens SS-A/Ro and SS-B/La are primary markers for systemic lupus erythematosus and Sjögren's syndrome. Recently, studies in animals demonstrated that green tea consumption may reduce the severity of some autoimmune disorders, but the mechanism is unclear. Herein, we sought to determine whether the most abundant green tea polyphenol, (-)-epigallocatechin-3-gallate (EGCG), affects autoantigen expression in human cells. Cultures of pooled normal human primary epidermal keratinocytes and of an immortalized human salivary acinar cell line were incubated with 100 microM EGCG (a physiologically achievable level for topical application or oral administration) for various time periods and then analyzed by cDNA microarray analysis, reverse transcription-polymerase chain reaction, and Western blotting for expression of several major autoantigen candidates. EGCG inhibited the transcription and translation of major autoantigens, including SS-B/La, SS-A/Ro, coilin, DNA topoisomerase I, and alpha-fodrin. These findings, taken together with green tea's anti-inflammatory and antiapoptotic effects, suggest that green tea polyphenols could serve as an important component in novel approaches to combat autoimmune disorders in humans.

Autoantigens↗

PubMed2005

Detection of flexoelectric effect from 4-heptyloxy-4'-cyanobiphenyl monolayers at an air-water interface by Maxwell displacement current and optical second harmonic generation.

The flexoelectric effect of 4-heptyloxy-4'-cyanobiphenyl (7OCB) monolayers at the air-water interface is studied by Maxwell displacement current (MDC) and optical second harmonic generation measurements. Though MDC was expected to increase during the compression of 7OCB monolayers in L2L2' phase from the MDC theory developed previously, decrease of MDC was detected in these phases. This abnormalous phenomenon is found to be due to the quench of flexoelectric effect by the flow orientation of monolayers.

Journal Article↗

PubMed2005

Effect of ethanol on metabolism of purine bases (hypoxanthine, xanthine, and uric acid).

There are many factors that contribute to hyperuricemia, including obesity, insulin resistance, alcohol consumption, diuretic use, hypertension, renal insufficiency, genetic makeup, etc. Of these, alcohol (ethanol) is the most important. Ethanol enhances adenine nucleotide degradation and increases lactic acid level in blood, leading to hyperuricemia. In beer, purines also contribute to an increase in plasma uric acid. Although rare, dehydration and ketoacidosis (due to ethanol ingestion) are associated with the ethanol-induced increase in serum uric acid levels. Ethanol also increases the plasma concentrations and urinary excretion of hypoxanthine and xanthine via the acceleration of adenine nucleotide degradation and a possible weak inhibition of xanthine dehydrogenase activity. Since many factors such as the ALDH2*1 gene and ADH2*2 gene, daily drinking habits, exercise, and dehydration enhance the increase in plasma concentration of uric acid induced by ethanol, it is important to pay attention to these factors, as well as ingested ethanol volume, type of alcoholic beverage, and the administration of anti-hyperuricemic agents, to prevent and treat ethanol-induced hyperuricemia.

Acetyl Coenzyme A↗

PubMed2005

Thr-774 (transmembrane segment M5), Val-920 (M8), and Glu-954 (M9) are involved in Na+ transport, and Gln-923 (M8) is essential for Na,K-ATPase activity.

The highly conserved amino acids of rat Na,K-ATPase, Thr-774 in the transmembrane helices M5, Val-920 and Gln-923 in M8, and Glu-953 and Glu-954 in M9, the side chains of which appear to be in close proximity, were mutated, and the resulting proteins, T774A, E953A/K, and E954A/K, V920E and Q923N/E/D/L, were expressed in HeLa cells. Ouabain-resistant cell lines were obtained from T774A, V920E, E953A, and E954A, whereas Q923N/E/D/L, E953K, and E954K could only be transiently expressed as fusion proteins with an enhanced green fluorescent protein. The apparent K0.5 values for Na+, as estimated by the Na+-dependent phosphoenzyme formation (K0.5(Na,EP)) or Na,K-ATPase activity (K(0.5)(Na,ATPase)), were increased by around 2 approximately 8-fold in the case of T774A, V920E, and E954A. The apparent K0.5 values for K+, as estimated by the Na,K-ATPase (K0.5(K,ATPase)) or p-nitrophenylphosphatase activity (K0.5(K,pNPPase)), were affected only slightly by the 3 mutations, except that V920E showed a 1.7-fold increase in the K0.5(K,ATPase). The apparent K0.5 values for ATP (K0.5(EP)), as estimated by phosphorylation (a high affinity ATP effect), were increased by 1.6 approximately 2.6-fold in the case of T774A, V920E, and E954A. Those estimated by Na,K-ATPase activity (K0.5(ATPase)) and ATP-induced inhibition (K(i,0.5)(pNPPase)) of K-pNPPase activity (low affinity ATP effects) were, respectively, increased by 1.8-fold and unchanged in the case of T774A but decreased by 2- and 4.8-fold in the case of V920E and were slightly changed and increased by 1.7-fold in the case of E954A. The E953A showed little significant change in the apparent affinities. These results suggest that Gln-923 in M8 is crucial for the active transport of Na+ and/or K+ across membranes and that the side chain oxygen atom of Thr-774 in M5, the methyl group(s) of Val-920 in M8, and the carboxyl oxygen(s) of Glu-954 in M9 mainly play some role in the transport of Na+ and also in the high and low affinity ATP effects rather than the transport of K+.

4-Nitrophenylphosphatase↗

PubMed2005

Blue light differentially alters cellular redox properties.

Blue light (lambda = 380-500 nm) historically has been used to initiate polymerization of biomaterials and recently has been proposed as a therapeutic agent. New evidence suggests that cell-type-specific responses result from redox changes induced by exposure to blue light. Cultured cells were exposed to defined doses of blue light, equivalent to exposure times of 10 s and 2 min, to achieve energies of 5 J/cm2 and 60 J/cm2, respectively, after which (a) viable cell number, (b) cellular protein profiles, (c) mitochondrial succinate dehydrogenase (SDH) activity, (d) total reactive oxygen species (ROS), and (e) induction of apoptosis were compared to that of nonexposed control cultures. Results showed that blue-light exposure arrested monocyte cell growth and increased levels of peroxiredoxins. SDH activity of normal epidermal keratinocytes (NHEK) was slightly enhanced by blue light, whereas identical treatment of OSC2 oral tumor cells resulted in significant suppression of SDH activity. Blue-light exposure generally induced higher levels of total ROS in OSC2 cells than in NHEK. Finally, only OSC2 cells exhibited signs of apoptosis via Annexin V staining following exposure to blue light. These data support the central hypothesis that blue light induces an oxidative stress response in cultured cells resulting in cell-type-specific survival outcomes. The identification of oxidative stress as a mediator of the effects of blue light is a critical first step in defining its biological risks and therapeutic opportunities.

Apoptosis↗

PubMed2005

Wear analysis of retrieved ceramic-on-ceramic articulations in total hip arthroplasty: Femoral head makes contact with the rim of the socket outside of the bearing surface.

We investigated articular bearing surfaces retrieved from three patients with ceramic-on-ceramic total hip arthroplasties using high-quality alumina. The duration of implantation was 3.5, 3.0, and 2.5 years, respectively. Dislocation of the hip joint after implantation did not occur in any patients. The retrieved prostheses were examined by stereomicroscopy and scanning electron microscopy (SEM). In the main load-bearing area, no wear marks were seen in any sockets. However, in all three cases, stripe scars were observed at the rim of the alumina inlay under stereomicroscopy, despite the lack of indentation in the socket and the stem, which suggests impingement. Such scars were not observed on the load-bearing surface. Under SEM, the scars showed excessive wear, including material excavation, that has not been observed in conventional hip simulator experiments. These findings are similar to those of experiments in which a simulator was programmed to distract the femoral head from the socket. The present results suggest that the femoral head can separate from the socket without neck-socket impingement in vivo.

Aged↗

PubMed2005

Huge pelvic mass secondary to wear debris causing ureteral obstruction.

We report an unusual granulomatous reaction of wear debris that produced a huge pelvic mass causing ureteral obstruction. A 72-year-old woman, who received a cemented total hip arthroplasty 30 years ago, was referred to the department of gynecology for examination of a pelvic mass. A computed tomography scan revealed a huge homogenous mass, measuring approximately 20 x 16 x 12 cm, including extensive osteolysis of the left pelvis around the acetabular component. Intravenous pyelogram revealed complete obstruction of the left ureter resulting in hydronephrosis of the left kidney. Histological examination from the biopsy specimen detected polyethylene wear debris in the mass.

Adult↗

PubMed2005

The Tajimi Study report 2: prevalence of primary angle closure and secondary glaucoma in a Japanese population.

PURPOSE: To determine the prevalence of primary angle-closure glaucoma (PACG), secondary glaucoma (SG), and all glaucoma in a Japanese population as a part of the Tajimi Study. DESIGN: Population-based epidemiological survey. PARTICIPANTS: A random sample of residents 40 years or older from Tajimi, Japan. INTERVENTION: Each subject underwent a screening program comprising an interview and an ophthalmic examination, including Goldmann applanation tonometry, slit-lamp examination, a van Herick test, fundus photography, and a screening visual field (VF) test using frequency-doubling technology. If glaucoma was suspected, the subject was referred for a definitive examination that included slit-lamp examination, gonioscopy, intraocular pressure measurement, a VF test, and optic disc and fundus examination. A diagnosis of PACG or SG was made based on slit-lamp examination, gonioscopy, optic disc appearance, and perimetric results. MAIN OUTCOME MEASURES: Prevalences of PACG, SG, and all cases of glaucoma. RESULTS: Of 3870 eligible people, 3021 (78.1%) participated in the study. Estimated prevalences of PACG and SG in those over 40 years were 0.6% (95% confidence interval [CI], 0.4%-0.9%) and 0.5% (95% CI, 0.2%-0.7%), respectively. Prevalences of all glaucoma and glaucoma/suspected glaucoma were estimated to be 5.0% (95% CI, 4.2%-5.8%) and 7.5% (95% CI, 6.5%-8.4%), respectively. CONCLUSIONS: Prevalences were 0.6%, 0.5%, and 5.0%, respectively, for PACG, SG, and all glaucoma in subjects over 40 years from Tajimi, Japan.

Adult↗

PubMed2005

Endoscopic suturing without extracorporeal knots: a laboratory study.

BACKGROUND: To eliminate cumbersome extracorporeal knotting, we designed a new endoscopic suturing device, the Eagle Claw V. The efficacy of the new device was tested on the Erlangen model and was compared with the initial extracorporeal knotting version (Eagle Claw II). METHODS: Segments of porcine splenic arteries were placed on the mucosal surface of the anterior wall of a pig stomach. The two ends of the artery were brought out through the gastric wall and were connected to a two-channel manometer. The Eagle Claw V has a curved needle with a detachable tip. After puncturing the tissue, the needle tip was engaged into a catching cartridge, where the suture had been embedded in a tightening mechanism. The suture could be tightened by simply pulling the end. The Eagle Claw V was used to plicate the splenic arteries mounted on the stomach. Suturing was considered secure if the suture could withstand endoluminal pressure greater than 200 mm Hg that lasted at least 10 seconds. RESULTS: Eleven of 15 stitches (73.3%) gained secure plication of the vessels. The suturing time (mean +/- standard deviation 2.93 +/- 0.80 minutes) was significantly faster than that of the Eagle Claw II (9.38 +/- 1.51 minutes). The device consistently achieved penetration of the muscular layer, and 4 of 15 sutures included the serosa. The 4 failures were because of suture breakage in two, thread entanglement in one, and cartridge dislodgement in one. CONCLUSIONS: The present prototype represents significant improvements in the ease of operation and the security of the suture, bringing the technique closer to clinical use for a variety of applications.

Animals↗

PubMed2005

Eagle Claw II: A novel endosuture device that uses a curved needle for major arterial bleeding: a bench study.

BACKGROUND: Control of bleeding from major arteries in the upper-GI tract remains difficult with currently available endoscopic devices. We designed an endosuture device that uses a curved needle and extracorporeal knotting, and assessed the device in stopping arterial bleeding in a bench model. METHODS: Harvested porcine splenic arteries (2-mm diameter) were tunneled submucosally in pig stomach with the open end protruding into an artificially created mucosal defect. The outer end of the vessel was connected to a pulsatile pump, and red ink was infused at a pressure of about 100 mm Hg. The stomach was installed on an Erlangen endo-training model. The suturing device (Eagle Claw II), mounted outside an endoscope, has an eyed, curved needle that carries a 3-0 nylon thread. After puncture, the thread was retrieved by using a hook. Three-throw square knots were tied at the thread extracorporeally and were pushed into place by using a knotting cap. The criteria of successful plication was defined as hemostasis after knotting, no leakage at pressures of >200 mm Hg, and the vessel was completely encircled by the suture. RESULTS: A total of 25 sutures were made with the mean time of 9.38 minutes (standard deviation 1.51). Control of the bleeding was obtained with 17 sutures (68%). The causes for failure were the following: a suture was too shallow (4), a loose knot (2), incorrect suture position (1), and stomach-wall edema (1). CONCLUSIONS: Control of bleeding from large arteries by using endoscopic suturing is possible. Continued refinements of the device are required.

Animals↗