Biomedical subjects

H Nagahama

Publications and source records attributed to H Nagahama.

At least 19 recordsLinked to original sources

PubMed2005

[Coronary artery bypass graftingin a patient with aortitis syndrome; report of a case].

We present a case of surgical treatment for a coronary lesion due to aortitis syndrome. A 41-year-old woman, suffering from aortitis syndrome and under prednisolone (PSL) therapy, underwent coronary artery bypass grafting (CABG). Surgical treatment was performed according to the aortic no-touch technique, but the patient showed a poor cardiac performance 5 days after the operation. This accident was resolved by increasing the PSL dose. Aortitis syndrome treated with PSL needs careful perioperative management besides an operative procedure.

Adult↗

PubMed2005

[Acute left ventricular rupture and cardiac tamponade caused by blunt trauma; report of a case].

It is difficult to save patients with acute left ventricular rupture and cardiac tamponade caused by blunt trauma. A 67-year-old man hospitalized due to sustained multiple blunt trauma. The systolic blood pressure was 40 mmHg. Chest computed tomography (CT) and ultrasonic echocardiography revealed cardiac tamponade. Abdominal CT indicated left renal contusion. Pericardial drainage via the subxiphoid approach drew about 1,000 ml of blood from the pericardial sac, which only transiently increased blood pressure. Median sternotomy and subsequent pericardiotomy revealed pulsatile bleeding jet through a laceration of about 2.0 cm long in the left ventricle near the first diagonal branch. After complete digital compression, the portion was covered by a biological tissue adhesive/sealant sheet (TachoComb), which completely suppressed bleeding. The postoperative course was uneventful. He was discharged from the hospital on the 20th day after the operation.

Acute Disease↗

PubMed2004

Fibronectin suppresses apoptosis and protects mice from endotoxic shock.

Multiple-organ failure related to septicemia is a common cause of early mortality after liver transplantation. Endotoxemia following living donor hepatectomy may be a cause of postoperative death. Plasma fibronectin (Fn) exerts a broad range of biological effects on cellular adhesion, motility, differentiation, apoptosis, hemostasis, wound healing, reticuloendothelial system function, and ischemic injury. We studied the therapeutic effect of plasma Fn in mice after an intraperitoneal injection of lipopolysaccharide (LPS) and d-galactosamine (GalN). Female Balb/c mice received simultaneous intraperitoneal injection of LPS (50 microg/kg) and GalN (400 mg/kg). Thirty minutes prior to GalN/LPS administration, plasma Fn or bovine serum albumin was given intravenously. A single administration of plasma Fn (500 mg/kg) protected in dose-dependent fashion against lethal shock after GalN/LPS challenge. Plasma Fn significantly reduced the serum tumor necrosis factor-alpha, interferon-gamma, and interleukin-6 levels and significantly increased the serum interleukin-10 levels after GalN/LPS administration. Furthermore, plasma Fn significantly inhibited liver necrosis at 9 hours after GalN/LPS injection. The fraction of apoptotic-positive cells in these plasma Fn-treated mice was significantly lower than in the control group. These results support the protective treatment of endotoxin-induced liver injury by plasma Fn.

Animals↗

PubMed2004

Microinfrared reflection spectroscopic mapping: application to the detection of hydrogen-related species in natural quartz.

A new method of microinfrared reflection spectroscopy and mapping analysis is briefly introduced. It was used to detect distributions and structures of hydrogen-related species (e.g. H(2)O, SiOH and SiH) in plastically deformed natural quartz. We used a Fourier transform-infrared spectrometer with a microscopic imaging system fully automated for all microscope functions (e.g. focusing, aperture, stage motion and measurements). Mapping can be made in thin sections with a thickness of 50 microm at room temperature and low temperatures (77 K) using a liquid N(2) cooling system. Infrared reflection spectra were obtained by five scans for each point with a range from 4000 to 400 cm(-1). The spectra were measured five times within about 2.5 s at each position. The scanning interval was 100-150 microm using a 100 x 100 microm(2) aperture. All obtained spectral data were stored in computer memory to construct two-dimensional mappings of infrared absorption. From the comparisons between infrared mapping images and deformation microstructures, in addition to the molecular H(2)O around 3600-3400 cm(-1), the hydrogen-related point defects (i.e. SiOH and SiH) around 970-900 cm(-1) within quartz grains and between grain boundaries increased with decreasing grain sizes (increasing plastic strain). The method can detect the SiOH and SiH along grain boundaries that enhance the hydrolytic weakening of natural quartz.

Journal Article↗

PubMed2003

[Successful management of traumatic aortic valve insufficiency; report of a case].

A case of the successful management of traumatic aortic valve insufficiency is reported. A previously healthy 48-year-old man sustained multiple injuries in a traffic accident. One month after the accident, heart failure, derived from aortic insufficiency, was noted. Three years and 5 months after the injuries, aortic valve replacement was performed, and a large tear, approximately 7 mm in length, was found in the aortic right coronary cusp. This finding corresponded to the traumatic aortic valve insufficiency. Traumatic aortic valve insufficiency is rare, and early diagnosis may be difficult. Examinations for associated intracardiac injuries should be carefully undertaken.

Accidents, Traffic↗

PubMed2001

Spatial and temporal expression patterns of the cyclin-dependent kinase (CDK) inhibitors p27Kip1 and p57Kip2 during mouse development.

The cyclin-dependent kinase (CDK) inhibitors p27Kip1 and p57Kip2 are thought to regulate progression of the cell cycle. We have previously shown that the phenotypes of p27-/- mice are substantially different from those of p57-/- mice, suggesting that spatial and temporal expression patterns of p27Kip1 and p57Kip2 might be distinct. In this study, the roles of p27Kip1 and p57Kip2 in development were examined by characterizing their expression patterns during mouse embryogenesis by immunohistochemical analysis. Whereas certain organs and tissues (brain, lens, ganglion, lung, heart, liver, skin and kidney) expressed both proteins, others expressed only p27Kip1 (thymus, spleen, retina, testis and ovary) or only p57Kip2 (gut, palate, pancreas, cartilage and skeletal muscle). In addition, some organs expressed both p27Kip1 and p57Kip2 but showed mutually exclusive patterns of distribution among tissues. Thus, in the adrenal gland, p57Kip2 was expressed in the cortex but not in the medulla, whereas p27Kip1 was expressed in the medulla but not in the cortex. Whereas the expression of p57Kip2 in most tissues was restricted to embryogenesis, expression of p27Kip1 in many tissues was maintained in adult animals. Double-label immunofluorescence staining with either anti-p27Kip1 or anti-p57Kip2 and anti-BrdU revealed that the expression of p27Kip1 and p57Kip2 was inversely correlated with cell proliferation, suggesting that p27Kip1 and p57Kip2 are expressed exclusively in postmitotic cells. These complex spatial and temporal patterns of expression are consistent with the phenotypes of mice deficient in p27Kip1 or p57Kip2, and they suggest that these proteins might play important roles in tissue development.

Adrenal Cortex↗

PubMed2001

Microanalysis of propofol in human serum by semi-microcolumn high-performance liquid chromatography with UV detection and solid-phase extraction.

OBJECTIVE: To develop a simple analytical method for monitoring the low serum levels of propofol found when administered for the sedation of patients in the intensive care unit (ICU). METHODS: A high-performance liquid chromatographic method (HPLC) was used with UV detection. Solid-phase extraction (SPE) cartridges and a semi-microcolumn (TSK gel ODS-80Ts, 2.0 mm i.d. x 25 cm, 5 microm) were used to improve sensitivity. Propofol in the eluate obtained from the SPE cartridge was concentrated to about five times the initial concentration. RESULTS: The sensitivity using the semi-microcolumn was amplified by about three-fold. The assay showed a good linearity with a quantification limit 20 ng/mL. Intra- and inter-assay coefficients of variation were less than 2.2% and 10.0%, respectively. The mean recoveries ranged from 97.6 to 109.5%. CONCLUSION: The HPLC method described should be useful for measuring the low serum propofol levels found when the drug is used for ICU sedation.

Chromatography, High Pressure Liquid↗

PubMed2000

Aberrant cell cycle checkpoint function and early embryonic death in Chk1(-/-) mice.

The recent discovery of checkpoint kinases has suggested the conservation of checkpoint mechanisms between yeast and mammals. In yeast, the protein kinase Chk1 is thought to mediate signaling associated with the DNA damage checkpoint of the cell cycle. However, the function of Chk1 in mammals has remained unknown. Targeted disruption of Chk1 in mice showed that Chk1(-/-) embryos exhibit gross morphologic abnormalities in nuclei as early as the blastocyst stage. In culture, Chk1(-/-) blastocysts showed a severe defect in outgrowth of the inner cell mass and died of apoptosis. DNA replication block and DNA damage failed to arrest the cell cycle before initiation of mitosis in Chk1(-/-) embryos. These results may indicate that Chk1 is indispensable for cell proliferation and survival through maintaining the G(2) checkpoint in mammals.

Alleles↗

PubMed2000

Targeted disruption of Skp2 results in accumulation of cyclin E and p27(Kip1), polyploidy and centrosome overduplication.

The ubiquitin-proteasome pathway plays an important role in control of the abundance of cell cycle regulators. Mice lacking Skp2, an F-box protein and substrate recognition component of an Skp1-Cullin-F-box protein (SCF) ubiquitin ligase, were generated. Although Skp2(-/-) animals are viable, cells in the mutant mice contain markedly enlarged nuclei with polyploidy and multiple centrosomes, and show a reduced growth rate and increased apoptosis. Skp2(-/-) cells also exhibit increased accumulation of both cyclin E and p27(Kip1). The elimination of cyclin E during S and G(2) phases is impaired in Skp2(-/-) cells, resulting in loss of cyclin E periodicity. Biochemical studies showed that Skp2 interacts specifically with cyclin E and thereby promotes its ubiquitylation and degradation both in vivo and in vitro. These results suggest that specific degradation of cyclin E and p27(Kip1) is mediated by the SCF(Skp2) ubiquitin ligase complex, and that Skp2 may control chromosome replication and centrosome duplication by determining the abundance of cell cycle regulators.

Animals↗

PubMed2000

Nafamostat mesilate treatment during open heart operation in immune thrombocytopenic purpura.

A 58-year old woman with idiopathic thrombocytopenic purpura underwent mitral and aortic valve replacements and tricuspid annuloplasty. Preoperative therapeutic interventions including prednisone and immunoglobulin were successful in elevating the platelet count to 93,000/ mm2. Furthermore, we used nafamostat mesilate for coagulopathy prophylaxis during cardiopulmonary bypass. Postoperative bleeding was average and clinical course was uneventful. The perioperative management for patients with idiopathic thrombocytopenic purpura requiring cardiac operation is reviewed.

Anticoagulants↗

PubMed1998

Site-directed mutagenesis and steady-state kinetic analysis of mutant enzymes of human adenylate kinase.

Site-directed mutagenesis of human adenylate kinase (AK) was carried out on residues His36, Lys55, and the C-terminal segment (Val182, V186, and Leu193). Five mutants [(H36T, K55G, V182G, V186S, and L193Stop (deletion of residues 193-194)] were generated and analyzed by steady-state kinetics. H36T, K55G, and L193Stop mutants showed an increase of K(m) values (19.8-, 19.7-, and 11.3-fold) for AMP2- compared to that for the wild-type enzyme, and these residues appeared to interact with AMP2-. V182G showed an increased K(m) value (7.4-fold) for MgATP2-. Therefore, V182 may be essential for interaction with MgATP2-. V186S increased the K(m) value (7.0- and 7.5-fold) for MgATP2- and AMP2-. V186 may thus interact with both substrates. The C-terminal domain of AK appears to be essential for MgATP2- and AMP2- binding.

Adenylate Kinase↗

PubMed1998

[The effects of midazolam on the memory of pain].

The purpose of this study was to evaluate the effects of low dose midazolam (MZ) on memories of spinal puncture. The low doses of MZ were administered to 70 patients (ASA 1-2), of whom 37 patients were premedicated with atropine sulfate 0.5 mg and pethidine hydrochloride i.m. (group P), and 33 patients received no premedication (group N). Double blind randomized trials were conducted with the doses of MZ (0, 0.03, 0.06 mg.kg-1), and MZ was administered i.v. to the patients just prior to spinal puncture. Subjective evaluation of pain was performed with pain score (PS) on postoperative phase, and objective evaluation of pain was performed with the reaction of spinal puncture. Short term memory was impaired mainly after administration of MZ. However, subjective memory of pain almost disappeared, but objective evaluation was not so good. We conclude that MZ induces impairment to recall of pain. However, it might maintain the response to the pain.

Adjuvants, Anesthesia↗

PubMed1998

[A survey of opioid use in preanesthetic medication].

A mailing survey was carried out to assess the current practice of sedative premedication in anesthesia. Questionnaires were sent by mail to 77 university hospitals. We especially evaluated use of opioids for premedication. Sixty-one percent (n = 47) of the hospitals answered these questionnaires and 31 percent (n = 15) of them were using opioids for the preanesthetic medication. Pethidine was used most frequently for premedication of all opioids, and morphine was often used for the premedication before cardiac surgery. All opioids were administrated intramusculary both in adults and children.

Adolescent↗

PubMed1997

Protracted 5-fluorouracil infusion with concurrent radiotherapy as a treatment for locally advanced pancreatic carcinoma.

BACKGROUND: Radiotherapy plus bolus 5-fluorouracil (5-FU) is generally accepted as the standard treatment for locally advanced pancreatic carcinoma. To intensify the antitumor effect of chemotherapy, the authors administered protracted 5-FU infusion with concurrent radiotherapy. The aim of this study was to determine the feasibility and effectiveness of this combined therapy. METHODS: Twenty patients, all of whom had histologically confirmed exocrine pancreatic carcinoma that was nonresectable but confined to the pancreatic region, were enrolled in a Phase II trial of protracted 5-fluorouracil infusion (200 mg/m2/day) with concurrent radiotherapy (50.4 gray in 28 fractions over 5.5 weeks). Chemotherapy began on the first day of radiation and continued through the entire radiation course. Thereafter, weekly infusions (500 mg/m2) were administered until disease progression. RESULTS: Of the 20 patients, 17 (85%) completed the scheduled course of chemoradiotherapy. Grade 3 or worse toxicity, graded according to World Health Organization criteria, was observed in 4 patients (20%). Two patients (10%) achieved partial response, and disease remained stable in 16 patients (80%). After the completion of combined therapy, serum CA 19-9 levels were reduced by more than 50% in 10 of 12 patients (83%) who had pretreatment CA 19-9 levels of 100 U/mL or greater. The median progression free survival and 1-year progression free survival rate were 4.9 months and 29.5%, respectively. The median overall survival and 1-year overall survival rate were 10.3 months and 41.8%, respectively. CONCLUSIONS: This treatment showed moderate activity against locally advanced pancreatic carcinoma and was accompanied by an acceptable toxicity level.

Adenocarcinoma↗

PubMed1997

Predictive factors for tumor response to systemic chemotherapy in patients with hepatocellular carcinoma.

Chemotherapy is of limited value in the treatment of hepatocellular carcinoma (HCC), since there are no established chemotherapeutic regimens proven to be effective. The aim of the present study was to determine predictive factors for tumor response to systemic chemotherapy in HCC patients. The relationship between patients' characteristics and tumor response was examined in 147 previously untreated HCC patients receiving systemic chemotherapy. Ten patients showed partial response (PR) and none showed complete response (CR). The response rate for all single anticancer agents was less than 10% and the overall response rate was 6.8%. The response rate in patients with unilateral HCC was significantly higher than in those with bilateral HCC. However, there were no responders among patients with a performance status of 2-3, ascites, a tumor occupying more than 50% of the entire liver, tumor thrombus in the main portal trunk or a serum bilirubin level of more than 2.0 mg/dl. There was a close relationship between patients' characteristics and tumor response. It is concluded that patients with fairly advanced HCC and/or poor hepatic reserve should not be given systemic chemotherapy.

Antineoplastic Agents↗

PubMed1997

Hepatocellular carcinoma with gastrointestinal hemorrhage caused by direct tumor invasion to the duodenum.

Gastrointestinal hemorrhage from hepatocellular carcinoma invading the duodenum is very rare. A 60-year-old man with multiple hepatocellular carcinoma was admitted to our hospital because of massive melena and hematemesis. We succeeded in hemostasis of an esophageal variceal rupture by endoscopic varicial ligation. The duodenum could not be observed endoscopically due to extramural compression to the stomach from the liver tumor. Massive gastrointestinal hemorrhage occurred again and the patient died of hepatic failure. The postmortem examination revealed that the liver tumor had invaded the second portion of the duodenum and perforated into the lumen.

Carcinoma, Hepatocellular↗

PubMed1997

[The use of low dose midazolam for the management of spinal anesthesia].

The purpose of this study was to evaluate the effects of low dose midazolam (MZ) on memories and ease of management of spinal anesthesia. The low doses of MZ were administered to 70 patients (ASA 1-2), of whom 37 patients were premedicated with atropine sulfate 0.5 mg and pethidine hydrochloride (group P), with 33 patients receiving no premedication (group N). Double blind randomized trials were conducted with the doses of MZ (0, 0.03, 0.06 mg.kg-1), and MZ was administered i.v. to patients just prior to spinal puncture. The short-term and long-term memories were impaired after administration of MZ in both groups. We conclude that MZ appears to be a suitable replacement for other benzodiazepines for relieving anxiety of patients during surgery.

Adolescent↗

PubMed1997

[Anesthesia in two patients with essential thrombocythemia].

Case 1. The patient was a 69-year-old man with essential thrombocythemia (ET), who underwent urgent laparotomy. On admission he was dehydrated and the platelet count was more than 160 x 10(4).microliter-1, with hematocrit of 50%. Anesthesia was induced with ketamine i.v. and maintained with nitrous oxide and sevoflurane in oxygen. Postoperative care included the administration of gabexate mesilate (GM) which is an antiplatelet agent. Case 2. An 84-year-old woman with ET was diagnosed as gastric cancer and elective gastrectomy was scheduled. The platelet count was more than 100 x 10(4).microliter-1. The patient was anesthetized with nitrous oxide and oxygen supplemented with fentanyl and mepivacaine via epidural catheter. Intravenous infusion of GM was performed at a rate of 1 mg.kg-1.hr-1 during surgery. PF-4 and beta-TG were measured. These are platelet releasing factors. The level of PF-4 decreased to normal level during this procedure. In conclusions, it will be important to use GM during anesthesia in order to avoid the complications such as myocardial or pulmonary infarction caused by thrombocythemia.

Aged↗