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Biomedical subjects

K Hashimoto

Publications and source records attributed to K Hashimoto.

At least 685 records · Page 38Linked to original sources

E-CELL: Software Environment for Whole Cell Simulation.

We present E-CELL, a generic computer software environment for modeling a cell and conducting experiments in silico. The E-CELL system allows a user to define functions of proteins, protein-protein interactions, protein-DNA interactions, regulation of gene expression and other features of cellular metabolism, in terms of a set of reaction rules. The system then executes those reactions iteratively, and the user can observe, through a computer display, dynamic changes in concentrations of proteins, protein complexes and other chemical compounds in the cell. Using this software, we constructed a model of a hypothetical cell with only 127 genes sufficient for transcription, translation, energy production and phospholipid synthesis. Most of the genes are taken from Mycoplasma genitalium, the organism having the smallest known chromosome, whose complete 580kb genome sequence was determined at TIGR in 1995. We discuss future applications of the E-CELL system with special respect to genome engineering.

Journal Article↗

[Reversible changes of cranial MRI in a girl with SLE].

The 11-year-old girl had hypertension and generalized tonic-clonic convulsions during the steroid pulse therapy. Her cranial T2-weighed MRI showed small areas of high signal intensity in the right occipital lobe. Her neurological findings were normal. After 2 months of steroid pulse therapy, multiple high signal intensities were demonstrated on T2-weighed MRI. After 5 months of the therapy, however, only a small T2-weighed MRI spot of high signal intensity in the white matter was observed, and the multiple lesions disappeared. On follow up, she did not show any neurological defects. It is postulated that not only steroid pulse therapy-induced hypertension but also SLE-induced angiopathy caused such flexible lesions. According to the literature, these lesions can be considered to be edema around small vessels. Such MRI findings have been reported in adult patients with SLE, but to our knowledge there have not been reports on children with SLE.

Brain↗

Detection of Borrelia burgdorferi DNA (B garinii or B afzelii) in morphea and lichen sclerosus et atrophicus tissues of German and Japanese but not of US patients.

OBJECTIVE: To elucidate the geographic and genospecific association of Borrelia with morphea and lichen sclerosus et atrophicus (LSA). DESIGN: The association of Borrelia burgdorferi with morphea and LSA has been reported, but is still controversial. We conducted a retrospective survey of Borrelia DNA in skin biopsy specimens. SETTINGS: The samples were collected from the outpatient clinic of university hospitals and a dermatopathology laboratory. PATIENTS: Skin biopsy specimens (19 morphea and 34 LSA) were obtained from patients in the United States, Japan, and Germany. DNA samples were subjected to amplification with polymerase chain reaction for B burgdorferi flagellin gene, and for the genotype-specific detection of B burgdorferi sensu stricto, Borrelia garinii, and Borrelia afzelii. RESULTS: Five cases of morphea and 2 cases of LSA in Germany and Japan yielded positive signals for B garinii or B afzelii, the European species. None of the American samples were positive for Borrelia polymerase chain reaction. Borrelia burgdorferi sensu stricto was not detected in any of the specimens. CONCLUSION: Morphea and LSA in Germany and Japan can be related with European genotypes of Borrelia.

Adolescent↗

[Semi-supervised exercise using a step machine at home after myocardial infarction].

Home exercise programs for patients with myocardial infarction effectively improve their ability to exercise as well as quality of life. However, there are no efficient methods for monitoring the patient's clinical status or conveying the physician's instructions to the home setting. To resolve these problems, we developed a computer-based, automated, telemetry system comprised of central and peripheral computers and telephone line. Five myocardial infarction patients were evaluated for peak oxygen uptake (peak VO2) and anaerobic threshold (AT) before hospital discharge. At home, the patients performed 10-min exercise using a step machine. Patient data including blood pressure, pulse rate, and electrocardiogram before and after exercise were stored in the peripheral computer, and the central computer automatically retrieved the data through the phone line. If the current heart rate was less than the heart rate at AT, extreme changes in blood pressure were noted or dangerous arrhythmias appeared, appropriate instructions were indicated on the display of the peripheral computer. Following these instructions, the patients continued home exercise programs for 6 months. Peak VO2 and AT increased significantly in all patients (peak VO2: baseline 24 +/- 3.3 ml/kg/min, 6 months later 33.3 +/- 3.7 ml/kg/min, p < 0.01, AT: baseline 15.2 +/- 2.7 ml/kg/min, 6 months later 18.5 +/- 2.8 ml/kg/min, p < 0.01). The computer-based automated telemetry system combined with a step machine facilitated effective prescription and monitoring of exercise programs at home.

Adult↗

[Genetic diagnosis of aspergillosis].

Aspergillosis is an opportunistic infection caused by pathogenic Aspergillus species (spp.) and is a major hazard for immunocompromised patients and even for non-immunocompromised individuals. Clinical diagnosis of aspergillosis, especially invasive pulmonary aspergillosis (IPA) is difficult and is largely presumptive, typically based on spiking fevers not responding to antibiotics in a patient with the risk factors. It is well known that Aspergillus spp. can be only infrequently cultured from clinical specimens, and that the cultural examination is laborious and time-consuming. Moreover, positive culture from bronchoalveolar lavage or sputa is indicative, but not proof of infection. The criterion for diagnosis of pulmonary infection by aspergilli requires repeated isolation of the same species of Aspergillus from respiratory specimens. There have been some successful attempts using serological assays to detect circulating antibodies to Aspergillus spp. in the noninvasive form of the disease, but these are generally negative in an acute phase IPA patient. A currently available serodiagnostic kit, Pastrex Aspergillus is limited in clinical usefulness because of low sensitivity and specificity in spite of being simple and rapid. Contamination of clinical specimens with various saprophytic filamentous fungi other than aspergilli also often give false positive. Diagnostic methods using such molecular biological techniques, as polymerase chain reaction (PCR) have recently been employed to identify DNA from a number of pathogens when diagnostic means are limited. PCR is known as the most sensitive and specific technique by which to detect a specific DNA sequence. In this paper we have reviewed new genetic methods of diagnosing aspergillosis including PCR and in situ hybridization.

Aspergillosis↗

[The relationship between statokinetic dissociation (SKD) and spatial summation--physiologic SKD in normal persons].

We investigated the relationship between physiologic statokinetic dissociation (SKD) and spatial summation in normal persons. The subjects were 13 eyes of 13 normal persons (average age : 41.9 years) with no past history of ocular disease. The kinetic program and custom program of the Humphrey Field Analyzer were followed for each subject using the targets of III 1b and III 4c to measure SKD. Spatial summation was calculated from the results of the 24 -2 program using size I, III, and V. The SKD of all normal persons for III 1b and III 4c was 18.8 +/- 3.4 and 20.1 +/- 5.4 degrees, respectively. The spatial summation for SS (III-I) and SS (V-III) was 9.8 +/- 0.7 and 4.7 +/- 0.9 (dB), respectively. Although the SKD on lower temporal meridian using the III 4c target was larger than that of the other meridian, this relation was reversed using the III 1b target. This is because the steep slope of the retina sensitivity curve in the periphery field decreases successive lateral spatial summation. Although SKD tends to be larger with the increase in age, the relationship between SKD and spatial summation was not obvious.

Adult↗

MR of spastic tetraplegia.

PURPOSE: To characterize the MR findings in children with spastic tetraplegia by gestational age at birth and perinatal history. METHODS: Thirty-four children, 19 boys and 15 girls, with spastic tetraplegia whose brain damage occurred in the prenatal or perinatal period were included in the study. Eighteen were born at term or later and 16 were premature. Axial proton density- and T2-weighted images and sagittal and coronal T1-weighted images were obtained on a 0.5-T MR imaging unit. RESULTS: All patients had abnormal MR findings, with a high prevalence of congenital anomalies (62.5%) in term patients who had experienced no adverse perinatal events. Term patients who had suffered detrimental perinatal events had a wide variety of brain lesions. A high frequency (75%) of periventricular leukomalacia was characteristic of preterm patients. CONCLUSION: MR imaging is useful for evaluating structural abnormalities in the brain and the extent of brain injury in patients with spastic tetraplegia.

Adolescent↗

[A case of malignant rheumatoid arthritis associated with myelodysplastic syndrome].

The patient (57 year-old female) complained of high fever and polyarthralgia in autumn of 1994, when a diagnosis of refractory anemia, a type of myelodysplastic syndrome (MDS) was made by severe anemia (RBC: 154 x 10(4)/microliters), leucopenia (2,200/microliters) and erythroid hyperplasia, ring-nucleated myelocyte, micromegakaryocyte and less than 5% of blasts in bone marrow smear. In her further clinical course, symptoms such as episcleritis, mononeuritis multiplex, skin ulcers on bilateral lower legs and circulating disturbance on left lower leg with high titer of rheumatoid factor were appeared in six months, suggesting malignant rheumatoid arthritis (MRA). She also had rectal cancer notified by anal bleeding. In spite of the administration of large doses of glucocorticoid and disease modifying anti-rheumatic drugs, circulating disturbance on left lower leg which might be caused by vasculitis was worsened to show tissue necrosis. Finally, she died of disseminated intravascular coagulation. The association of MDS with rheumatic disorders such as rheumatoid arthritis, Behçet disease and Sjögren's syndrome is not rarely reported. However, this is the first case of MDS associated with MRA.

Arthritis, Rheumatoid↗

Correlation between HLA-DR expression and level of poly(ADP-ribose) synthetase in human thyroid carcinoma cells.

The expression of MHC class II molecules is normally restricted to antigen presenting cells. Aberrant expression of class II molecules, however, was detected in the thyrocytes of autoimmune thyroid diseases. We attempted to regulate the expression of HLA-DR molecules in thyroid carcinoma cells by expressing the exogenous poly(ADP-ribose) synthetase gene. We transfected a metal inducible expression plasmid capable of expressing poly(ADP-ribose) synthetase gene into thyroid carcinoma 8505C cells and the transformants, treated with metal and IFN-gamma, were separated by Magnetic Cell Separation. The activity of the synthetase was increased in the HLA-DR-enriched transformants as compared with that in control or the HLA-DR+ transformants. RNA blot analysis and flow cytometric analysis revealed that the IFN-gamma-inducible expression of HLA-DR molecules was depressed by the induction of exogenous poly(ADP-ribose) synthetase gene. This result indicates that HLA-DR expression was correlated with the level of poly(ADP-ribose) synthetase in human thyroid carcinoma cells. Furthermore we examined the level of poly(ADP-ribose) synthetase in patients with autoimmune thyroid diseases. We observed a significant decrease in poly(ADP-ribose) synthetase in the patients. Taken together with the previous observation, the decrease in poly(ADP-ribose) synthetase is closely linked to the aberrant expression of HLA-DR molecules in some autoimmune thyroid diseases.

Autoimmune Diseases↗

[Anesthetic management using transesophageal echocardiography during removal of a cardiac myxoma].

Removal of a cardiac myxoma can be complicated by mitral stenosis, arterial embolism and so on, all of which may be life-threatening but difficult to diagnose. We describe the use of transesophageal echocardiography (TEE) for the anesthetic management of two patients undergoing removal of a large myxoma in the left atrium (LA). The first case is a 78-yr-old woman, who was suffering from cardiac cachexy with a large LA myxoma. The anesthetic management of her surgery required the prevention of a decrease in cardiac output caused by anesthetic agents, massive bleeding and surgical procedures. The second case is an asymptomatic 60-yr-old man with LA myxoma, which appeared adherent to the mitral orifice in diastole. The goal of the anesthetic management of him was to prevent the obstruction of transmitral blood flow caused by the decrease in preload on the heart. Throughout the surgeries, TEE monitoring was conducted and helped decide the doses and/or rate of inotropes and vasodilators as well as the transfusion of fluid and blood to obtain stable circulatory conditions. It was also found to be of considerable value in understanding the pathophysiology of the tumors in LA. In conclusion, TEE monitoring during the surgery can be of much use both in the diagnosis and the anesthetic management of a patient with a large LA myxoma.

Aged↗

[A patient with acromegalic heart disease--a case report].

A perioperative anesthetic management of a 69 year old woman with acromegaly whose clinical course was characterized by severe heart failure is described. The patient showed symptoms of massive cardiomegaly. Endocrine studies indicated that her pituitary tumor was active with hyperproduction of growth hormone. There was no demonstrable evidence for other known causes of heart disease. Following hormonal therapy using continuous subcutaneous infusion of somatostatin for about two months, there was improvement in daily activity and reduction in heart size. After the improvement of cardiac function, transsphenoidal hypophysectomy was performed under general anesthesia and its perioperative course was quite uneventful. We conclude that because cardiac involvement such as left ventricular dilatation in acromegaly might be reversible with proper treatment, any surgical procedure, as long as the case is elective, should be considered after hormone therapy.

Acromegaly↗

[Severe acute cardiac failure caused by the combination of the aortic stenosis and sudden onset of the mitral chordae rupture].

The patient, who had an aortic stenosis, suddenly complicated with severe acute cardiac failure. The rupture of the mitral chordae tendineae was detected by the echocardiogram. Double replacements (aortic and mitral) were done immediately after the onset of chordae rupture. This condition, combination of aortic stenosis and sudden onset of chordae rupture, always results in severe heart failure which is explained by the combination of pressure and volume loading. Finally the emergent operation is believed to be an only solution for this situation.

Acute Disease↗

Cardiovascular and antiarrhythmic effects of the azulene-1-carboxamidine derivative N1,N1-dimethyl-N2-(2-pyridylmethyl)-5-isopropyl-3, 8-dimethylazulene-1-carboxamidine.

The azulene-1-carboxamidine derivative N1,N1-Dimethyl-N2-(2- pyridylmethyl)-5-isopropyl-3,8-dimethyl-azulene-1-carboxamidine (CAS 186086-10-2, HNS-32) is a newly synthesized compound. In the present study, direct cardiovascular effects of HNS-32 were assessed using the canine isolated, blood-perfused sinoatrial node, papillary muscle and atrioventricular node preparations, while the antiarrhythmic action was examined using the canine two-stage coronary ligation-induced arrhythmia model. Intracoronary administration of HNS-32 (1-300 micrograms) suppressed the sinus nodal automaticity and ventricular contractile force, while it increased the atrio-His and His-ventricular conduction time as well as the coronary blood flow. Intravenous administration of HNS-32 (5 mg/kg) suppressed the ventricular arrhythmia for approximately 30 min. Since HNS-32 possesses multiple cardiac direct effects which are unique compared with well-established antiarrhythmic drugs, it may become a leading compound in the search for novel antiarrhythmic agents.

Animals↗

Herpetiform pemphigus showing reactivity with pemphigus vulgaris antigen (desmoglein 3)

We report a patient with herpetiform pemphigus (HP) who showed reactivity only with pemphigus vulgaris (PV) antigen but not with pemphigus foliaceus (PF) antigen. Direct and indirect immunofluorescence revealed keratinocyte cell surface staining in the lower layers of the epidermis, where desmoglein 3 (Dsg3) is expressed. Immunoblot analysis, using ethylenediamine tetra-acetic acid-separated human epidermal extracts, revealed that the patient's serum recognized only a 130-kDa polypeptide which co-migrated with Dsg3. By antigen-specific immunoadsorption studies, using desmoglein 1 (Dsg1) and Dsg3 recombinant protein produced by baculovirus expression system, immunoreactivity of the patient's serum was completely adsorbed by Dsg3 alone, but not by Dsg1. These results indicate that this HP patient produced only anti-Dsg3 autoantibodies and no other autoantibodies against components of the keratinocyte cell surface. HP could be a variant of PV, in addition to PF, with unique clinical and histological features.

Autoantigens↗