Publications by authors named "Toru Koyama"

Background: This study aimed to clarify the effects of underlying diseases on clinical outcomes of patients aboard a world cruise ship.

Methods: This prospective cohort study included patients who sought physician consultations at an onboard clinic on a 105-day world cruise (September-December 201X) on a ship chartered by a Japanese travel agency. Multivariable logistic regression analysis was performed to ascertain whether any concurrent disease, such as hypertension, was associated with additional onboard treatment by the primary physician or serious events, including unexpected final disembarkation, temporary disembarkation for hospitalization ashore, shore-side referral, and onboard clinic admission.

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Aim: The aim of this study was to better understand the usefulness of retrospective inspection of radiology reports of CT (computed tomography) or MRI (magnetic resonance imaging) by emergency doctors in the emergency room.

Methods: Between April 2018 and March 2019, patients who went home after CT or MRI who needed to change their treatment plans and subsequent corresponding procedures after inspection of radiology reports by emergency doctors were reviewed.

Results: Among 7,661 CT or MRIs performed on 5,917 patients, there were 131 patients (133 CT or MRI or 1.

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Aim: The purpose of this study was to better understand the effects of introducing the Japan Triage and Acuity Scale (JTAS) in the emergency room for walk-in patients.

Methods: A simple triage was used in Term A (from April 2006 to December 2010, 4 years and 9 months) and the JTAS was introduced in Term B (from January 2011 to September 2015, 4 years and 9 months). The number of patients who had a sudden turn for the worse after arrival in the emergency room and the time between attendance and emergency catheterization (TBAEC) due to acute coronary syndrome were reviewed.

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We report a case involving accidental ingestion of a marble that was detected by point-of-care ultrasonography of the abdomen with the patient in the upright and slightly forward tilting position, which we term the "bowing position." Using this position for abdominal ultrasonography may be more useful than the usual supine position for such patients.

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The one-step conversion of ethanol to 1,3-butadiene was performed using talc containing Zn (talc/Zn) as a catalyst. The influence of the MgO and Zn in the talc on the formation rate and selectivity for 1,3-butadiene were investigated. MgO as a catalyst afforded 1,3-butadiene with a selectivity that was nearly the same as talc/Zn at ∼40% ethanol conversion at 673 K, although the rate of 1,3-butadiene formation over MgO was about 40 times lower than that over the talc/Zn.

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A 78-yr-old man was admitted in emergency with fatigue, anorexia, vomiting, hypothermia (35.1 °C on a hot August day), hypotension (89/56 mmHg) and hyponatraemia (126 mEq/l). Plasma corticotropin and cortisol were severely depressed: 0.

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Background: No prospective study of gamma knife thalamotomy for intractable tremor has previously been reported.

Objective: To clarify the safety and optimally effective conditions for performing unilateral gamma knife (GK) thalamotomy for tremors of Parkinson disease (PD) and essential tremor (ET), a systematic postirradiation 24-month follow-up study was conducted at 6 institutions. We present the results of this multicenter collaborative trial.

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A 62-year-old man, receiving chronic haemodialysis and suffering from alcoholic liver cirrhosis and chronic pancreatitis, presented with hypoglycaemic coma. Plasma cortisol was undetectable (< 5.5 nmol/L) with suppressed adrenocorticotropic hormone (ACTH), which established a diagnosis of adrenal failure due to ACTH deficiency.

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A plausible reaction mechanism for propylene (C(3)H(6)) production from ethylene (C(2)H(4)) was investigated, based on the amounts of effluent hydrocarbons and hydrocarbons produced in the pores of SAPO-34. Propylene was produced via an oligomerization-cracking mechanism. On the basis of this mechanism, the conversions of C(2)H(4), pentenes, and hexenes were examined.

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To investigate the effect of SAPO-34 particle size (with a fixed Si mole fraction in its framework) and that of the Si mole fraction (in a SAPO-34 framework with fixed particle size) on propylene selectivity and production rate for the conversion of ethylene to propylene, SAPO-34 was prepared by hydrothermal synthesis using tetraethyl ammonium hydroxide or morpholine as a structural agent. The conversion of ethylene was carried out at 473 K using SAPO-34. The selectivity for propylene, the rate of propylene production, and the lifetime of the catalyst were strongly influenced by the catalyst crystal size.

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A patient with cerebral deep sinus thrombosis, which was not diagnosed on the first examination, is reported. A 46-year-old woman presented with headache and vomiting. Neurological examination and a brain computed tomography (CT) scan showed no obvious abnormal findings.

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Protein-bound polysaccharide K (PSK) increased the 5-year disease-free survival rate and reduced the risk of recurrence in a randomised, controlled study for stage II and III colorectal cancer. In order to elucidate the disease-free survival benefits with PSK and what immunological markers could indicate a PSK responder, serial changes in immunological parameters were monitored in the study. PSK decreased the mean serum immunosuppressive acidic protein (IAP) level, and increased the mean population of natural killer (NK) cells compared with the controls.

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Background/aims: Liver resection has improved the survival of colorectal cancer patients with metastases. However, there are groups at high risk of recurrence after liver resection. This report reviews our results using anatomical liver resection and analyzes the prognostic factors.

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A 68-year-old woman with no history of cardiac events suffered acute myocardial infarction after surgery for middle cerebral artery (MCA) occlusion manifesting as transient left motor weakness. Diffusion-weighted magnetic resonance imaging revealed multiple infarctions in the right cerebral hemisphere. Magnetic resonance angiography and cerebral angiography demonstrated an occlusion at the horizontal segment of the right MCA and no collateral circulation.

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Background: A rare case of a growing dissecting aneurysm, which was located at the horizontal (A1) segment of the anterior cerebral artery (ACA), is reported.

Case Description: A 53-year-old woman experienced left hemiparesis and alien hand syndrome. A computerized tomography scan showed an infarction in the right frontal lobe, and cerebral angiography revealed a false lumen and intimal flap at the A1 segment of the ACA.

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A 24-year-old woman was struck on the head by a hammer. Because of early signs and symptoms of intercranial hypertension, she underwent surgery for elevation of the depressed fragments which was compressing the superior sagittal sinus (SSS). After operation, the intracranial pressure (ICP) once decreased, but it gradually increased again.

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The evasion of apoptosis has been linked to the development of cancer. A recent study of a small number of gastric and colorectal cancers found that the BAK gene, which encodes a pro-apoptotic protein, contained somatic mutations in approximately 17% of the samples analyzed. To investigate the precise frequency of BAK mutations, we examined the entire coding sequence of the BAK gene in gastric and colorectal cancers, using polymerase chain reaction-single-strand conformational polymorphism (PCR-SSCP) analysis and direct sequencing.

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MBD4/MED1 is a newly identified mismatch repair gene, which is mutated in colon, endometrial, and pancreatic high-frequency microsatellite instability (MSI-H) tumors. To assess its role in gastric cancers, we investigated MBD4/MED1 mutations in sporadic gastric cancers, compared with colon cancers. Frameshift mutations were found in 29% of gastric and 20% of colon MSI-H cancers, but not in any low-frequency microsatellite instability/microsatellite stable cancers.

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Background: Aberrant activation of Wnt signaling caused by mutations in the tumor suppressor adenomatous polyposis coli or beta-catenin is a critical event in the development of human colorectal tumors. We have recently identified the ICAT gene, which encodes a small protein that interacts with beta-catenin and represses Wnt signaling.

Methods: We examined the prevalence of mutations in the entire ICAT coding sequence and intronic splice donor and acceptor regions of ICAT by PCR-SSCP and also the expression of the ICAT gene by RT-PCR.

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Hemophagocytic syndrome is a rare but often fatal condition, and little is known about why this disorder can occur following surgery. We report herein the case of a patient successfully treated for a hemophagocytic syndrome-like condition that developed after emergency right hemicolectomy for a retroperitoneal abscess secondary to perforated colon cancer. The 62-year-old man initially presented after the sudden development of severe right back pain, and computerized tomography scans revealed a retroperitoneal abscess continuous with a tumor in the ascending colon.

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Background/aims: Omentoplasty--wrapping the omentum around the alimentary tract anastomosis is thought to lower the rate of anastomotic leakage. We evaluated the role of omentoplasty to reinforce cervical esophagogastrostomy after radical esophagectomy.

Methodology: We compared anastomotic leakage, stricture formation, and related deaths in 63 patients who underwent radical esophagectomy and cervical esophagogastrostomy, with (n = 48) or without (n = 15) omentoplasty, between 1995 and 1999.

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Objective And Importance: A rare case of an aneurysm arising at the fenestration of the P2 segment of the posterior cerebral artery is reported.

Clinical Presentation: A 37-year-old man presented with severe headache and disturbance of consciousness. Computed tomographic scanning showed diffuse subarachnoid hemorrhage.

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Synopsis of recent research by authors named "Toru Koyama"

  • - Toru Koyama's research primarily focuses on clinical and emergency medicine, exploring patient outcomes and treatment efficacy in various critical scenarios, such as onboard medical care during cruises and the role of diagnostic imaging in emergency situations.
  • - Key findings from his studies indicate significant impacts of underlying diseases on clinical outcomes aboard cruise ships, as well as the beneficial effects of radiology report reviews in emergency departments for improving treatment decisions.
  • - Koyama has also contributed to advancing medical procedures, such as the introduction of the Japan Triage and Acuity Scale in emergency care, and innovative diagnostic methods like point-of-care ultrasound in assessing ingested foreign bodies.