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Biomedical subjects

T Katoh

Publications and source records attributed to T Katoh.

At least 181 records · Page 10Linked to original sources

The lack of type III collagen in a patient with aneurysms and an aortic dissection.

We analyzed 79 consecutive patients with aneurysms and found a patient who lacked type III collagen. Collagen was extracted from the skin, and the lack of type III collagen was determined by means of sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). Only 1 of the 79 patients was found to lack type III collagen. This patient was a 55-year-old man who had sustained an abdominal aortic aneurysm and aortic dissection. He did not show any of the typical clinical symptoms of Ehlers-Danlos syndrome type IV, such as hyperextensible skin and joints. He had none of the usual risk factors nor any clear family history of the syndrome. Furthermore, his collagen fibrils demonstrated a homogeneous appearance. This case may represent a new form of type III collagen deficiency.

Aortic Dissection↗

Immunolocalization of prolyl 4-hydroxylase in rabbit lens epithelial cells.

PURPOSE: To localize the enzyme prolyl 4-hydroxylase in the crystalline lens and determine the ability of lens epithelial cells (LECs) to synthesize procollagen. SETTING: Research laboratory, Department of Ophthalmology, Wakayama Medical College, Wakayama, Japan. METHODS: Phacoemulsification and aspiration of the crystalline lens followed by implantation of a poly(methyl methacrylate) intraocular lens (IOL) were performed in 1 eye each of 6 albino rabbits; the eye was enucleated 1 or 2 months later. Crystalline lenses were also extracted from the eyes of 2 rabbits. These samples were processed for immunohistochemical detection of the alpha- and beta-subunits of prolyl 4-hydroxylase. RESULTS: A monolayer of LECs was detected on the inner surface of the intact anterior capsule. Antibodies directed against both subunits of prolyl 4-hydroxylase reacted strongly to LECs proliferating on capsules with IOLs, whereas little or no reaction was observed in quiescent LECs or in the regenerated lenticular structure. CONCLUSION: The presence of prolyl 4-hydroxylase in LECs proliferating on the inner surface of the lens capsule suggests that these cells are involved in the production of procollagen and fibrosis during capsular injury and repair. Suppression of prolyl 4-hydroxylase activity may prevent the capsule opacification that results from cataract removal and IOL implantation.

Animals↗

Giant cell granulamatous hypophysitis with remarkable uptake on Gallium-67 scintigraphy.

We treated a man with giant cell granulomatous hypophysitis with pituitary enlargement, as seen on magnetic resonance imaging. Endocrinological examination revealed panhypopituitarism and diabetes insipidus. Microscopic examination of the specimen obtained by transsphenoidal pituitary biopsy revealed a granulomatous lesion, composed of epitheliod cells, Langhans' multinucleated giant cells, lymphocytes and other chronic inflammatory cells. On whole body gallium-67 scintigraphy, there was extensive uptake in the pituitary gland. Gallium-67 scintigraphy may greatly aid in the diagnosis of granulomatous hypophysitis.

Adult↗

Anti-latent TGF-beta binding protein-1 antibody or synthetic oligopeptides inhibit extracellular matrix expression induced by stretch in cultured rat mesangial cells.

Transforming growth factor-beta (TGF-beta) is usually secreted as a large latent complex associated with latent TGF-beta binding protein-1 (LTBP-1), which is known to bind to extracellular matrix (ECM) components. Although the LTBP-ECM interaction has been suggested to play a role in the activation and biological action of TGF-beta, the precise mechanism is still unclear. In glomerular hypertension mesangial cells are believed to perceive the increased cyclic strain and we have recently reported that cyclic mechanical stretch in vitro enhances the expression of ECM components via an autocrine/paracrine secretion of TGF-beta in cultured rat mesangial cells. Therefore, in this study we examined the role of LTBP-1 in the stretch-induced, TGF-beta-mediated ECM expression. Mesangial cells expressed mRNA for short and long forms of LTBP-1 (LTBP-1S and LTBP-1L, respectively). Mesangial cells were subjected to cyclic stretch to provide a maximal elongation of 20% at a rate of 60 cycles/min for 24 to 36 hours in the presence of polyclonal antibody raised against human LTBP-1 or synthetic oligopeptides corresponding to the N-terminal portions of human LTBP-1, which may work as competitive inhibitors against the LTBP-ECM association. Both anti-LTBP-1 antibody (Ab39) and synthetic oligopeptides inhibited the stretch-induced mRNA expression of type I collagen and fibronectin in a dose-dependent manner, but the inhibition by Ab39 or the oligopeptides was recovered by adding recombinant TGF-beta. Ab39 or the oligopeptides did not change the effect of exogenously added TGF-beta, such as growth-inhibition in mink lung epithelial cells. These results suggest that mesangial cells secrete TGF-beta as a large latent complex, and the LTBP-ECM interaction may be a pivotal step in TGF-beta action and ECM accumulation, providing a new therapeutic strategy against progression of glomerulosclerosis and other fibrotic diseases.

Amino Acid Sequence↗

Late postoperative respiratory function in adults after surgical correction of atrial septal defects. Analysis of respiratory dysfunction patterns.

Respiratory function after repair of atrial septal defect (ASD) was analysed in 44 adults (> 40 years), 21 of whom had preoperative respiratory dysfunction, 14 of restrictive type, defined as % vital capacity (% VC) less than 80% of predicted value, 3 with an obstructive pattern, defined as % forced expiratory volume/1 s (% FEV1) less than 70% of predicted value, and 4 patients with a mixed pattern. Increased % VC was found postoperatively in all 14 patients with restrictive respiratory dysfunction, with normal values in 8 out of the 14. Although the three patients with obstructive, and the four with mixed-pattern respiratory dysfunction improved preoperatively in % VC or % FEV1, or both, none had normalized values. We conclude that preoperative restrictive respiratory dysfunction in ASD patients frequently normalizes postoperatively, but not dysfunction of obstructive or mixed restrictive-obstructive type.

Adult↗

A pilot study testing the association between N-acetyltransferases 1 and 2 and risk of oral squamous cell carcinoma in Japanese people.

Risk of oral cancer has been associated with exposure to tobacco smoke, alcohol and with genetic predisposition. The aromatic amines and their metabolites, a class of carcinogens present in tobacco smoke, undergo metabolism (activation or detoxification) through an N- or O-acetylation pathway by the polymorphic enzymes, N-acetyltransferases (NAT)1 or NAT2. The genes that encode these enzymes, NAT1 and NAT2, have a variety of high and low activity alleles and we analyzed these genetic polymorphisms in 62 oral squamous cell carcinoma cases, and 122 healthy control subjects from Japan. NAT1 alleles tested were NAT1*3 (C1095A), NAT1*4 (functional reference allele), NAT1*10 (T1088A,C1095A), NAT1*11(9 bp deletion), NAT1*14 (G560A), NAT1*15 (C559T) and NAT1*17 (C190T). No low activity alleles (NAT1*14, NAT1*15 and NAT1*17) were observed in these Japanese subjects. We observed significantly increased risk [odds ratio 3.72; 95% confidence interval (CI) 1.56-8.90; P < 0.01] associated with the NAT1*10 allele, an allele that contains a variant polyadenylation signal. Stratifying by smoking status we found odds ratios of 5.9 (95% CI 1.13-30.6; P < 0.05) for non-smokers with the NAT1*10 allele and 3.1 (95% CI 1.09-9.07; P < 0.05) for smokers, but these risks were not significantly different from each other. Thus, we did not observe that NAT1*10 alleles confer differential risk among smokers and non-smokers. NAT2 rapid acetylation genotype was not a significant risk factor for oral cancer in this Japanese study population. This is the first study to test for oral cancer risk associated with polymorphism in the NAT1 and NAT2 genes, and these positive findings in our pilot study, while based on small numbers, suggest that the NAT1*10 allele may be a genetic determinant of oral squamous cell carcinoma among Japanese people.

Acetylation↗

Conformation, filament assembly, and activity of single-headed smooth muscle myosin.

Single-headed myosin was prepared by digestion of porcine aorta smooth muscle myosin with Staphylococcus aureus V8 protease in the presence of actin. The single-headed myosin preparation contained intact light chains, a rod fragment of a heavy chain, and a heavy chain of which only a minor fraction contained a nick in the head segment. Below 0.2 M NaCl, the single-headed myosin showed a decrease in Ca2+-ATPase activity and an increase in the elution time on gel filtration HPLC in a phosphorylation-dependent manner, indicating a phosphorylation-dependent conformational transition between the extended and folded forms. These conformations were confirmed by electron microscopic observation of rotary-shadowed samples of single-headed myosin. However, the conformational transition of single-headed myosin occurred in a narrower range with lower salt concentrations than that of double-headed myosin. The filament assembly of single-headed myosin was thus facilitated and phosphorylation-independent. The single-headed myosin also showed high actin-activated ATPase activity independent of phosphorylation. These results indicate that the two-headed structure of smooth muscle myosin is not essential for the conformational transition, but is required for the phosphorylation-dependent regulation of enzymatic activity and filament assembly.

Actin Cytoskeleton↗

The effect of adenosine triphosphate on sevoflurane requirements for minimum alveolar anesthetic concentration and minimum alveolar anesthetic concentration-awake.

UNLABELLED: We evaluated the effects of i.v. adenosine triphosphate (ATP) on sevoflurane minimum alveolar anesthetic concentration (MAC) and MAC-Awake. The study group included healthy patients 20-60 yr of age. The study groups for MAC-Awake determination included 49 patients who were scheduled for elective surgery. The study groups for MAC determination included 53 patients scheduled for elective surgery involving a skin incision. These patients were randomly assigned to two groups, an ATP group and a control group. The ATP group received 100 micrograms.kg-1.min-1 ATP i.v., and the control group received no medication. The ATP group and the control group were compared with regard to MAC-Awake (anesthetic concentration achieving 50% probability of eye opening in response to a verbal command) and MAC (anesthetic concentration achieving 50% probability of no movement in response to skin incision). The MAC-Awake was 0.7% +/- 0.1% in the control group (mean +/- SD) and 0.7% +/- 0.1% in the ATP group. MAC was 1.9% +/- 0.1% in the control group and 2.1% +/- 0.2% in the ATP group. The differences in MAC and MAC-Awake between the two groups were not statistically significant. We conclude that ATP infusion (100 micrograms.kg-1.min-1) has no effect on sevoflurane MAC and MAC-Awake. IMPLICATIONS: We found that an i.v. adenosine triphosphate infusion (100 micrograms.kg-1.min-1) has no effect on sevoflurane minimum alveolar anesthetic concentration (anesthetic concentration achieving 50% probability of no movement in response to skin incision) and minimum alveolar anesthetic concentration-Awake (anesthetic concentration achieving 50% probability of eye opening in response to a verbal command) in humans.

Adenosine Triphosphate↗

Propofol concentration required for endotracheal intubation with a laryngoscope or fiberscope and its interaction with fentanyl.

UNLABELLED: The administration of fentanyl with propofol reduces the blood concentration of propofol required to achieve adequate anesthesia for tracheal intubation. However, different intubation procedures have variable intensities of noxious stimulation and may require different levels of anesthesia. The goal of this study was to determine the propofol blood concentration at which 50% of patients did not respond to stimulation (Cp50) for laryngoscopy, intubation with a laryngoscope, insertion of a slotted oral-pharyngeal airway (Ovassapian airway), and intubation with a fiberscope when administered in conjunction with fentanyl. Patients undergoing elective surgery were given varying amounts of propofol or propofol with fentanyl, and their responses to the four procedures listed above were assessed. These experiments demonstrated that the propofol concentration required for intubation with a laryngoscope was similar to that for intubation with a fiberscope, and that the required level was reduced by fentanyl. Hemodynamic responses to intubation were lower with a fiberscope than with a laryngoscope. We conclude that almost the same concentrations of propofol or fentanyl are necessary for suppressing both of the somatic responses to tracheal intubation with a fiberscope or a laryngoscope. Hemodynamic responses were attenuated more during intubation with a fiberscope. IMPLICATIONS: The propofol blood concentrations at which 50% of patients did not respond to stimulation for laryngoscopy, tracheal intubation with a laryngoscope, and tracheal intubation with a fiberscope were 10.9, 19.6, and 19.9 microg/mL, respectively. These were reduced by fentanyl. Hemodynamic responses to intubation were less with a fiberscope than with a laryngoscope.

Adult↗

The effects of fentanyl on sevoflurane requirements for loss of consciousness and skin incision.

BACKGROUND: Fentanyl produces a minimal reduction in the minimum alveolar concentration of sevoflurane to prevent response to a verbal command in 50% of patients (MAC[awake]) at low but analgesic plasma concentrations. The reduction in MAC(awake), however, is still unknown at higher fentanyl concentrations. The reduction in the MAC of sevoflurane by fentanyl has not been described accurately. The purpose of this study was to determine the MAC(awake) and MAC reduction of sevoflurane by fentanyl. METHODS: Ninety-two patients were randomly allocated to seven fentanyl concentration groups (target plasma concentrations of 0, 1, 1.5, 3, 6, 10, and 14 ng/ml). Responses to verbal command were observed for MAC(awake) assessment at predetermined sevoflurane concentrations. Thereafter, in patients whose target fentanyl concentration was 0 to 10 ng/ml, responses to skin incision were observed for MAC assessment at new steady-state sevoflurane concentrations. The reduction in the MAC(awake) and MAC of sevoflurane by the measured fentanyl concentration was calculated. RESULTS: There was an initial steep reduction in the MAC of sevoflurane by fentanyl, with 3 ng/ml resulting in a 59% MAC reduction. A ceiling effect was observed, with 10 ng/ml providing only a further 17% reduction in MAC. The initial reduction in MAC(awake) was not as steep as that in MAC. Fentanyl reduced MAC(awake) by approximately 24% at a plasma concentration of 3 ng/ml. Although the reduction curve of MAC(awake) was parabolic, no manifest ceiling effect was observed at concentrations administered in the present study. CONCLUSIONS: The reduction in sevoflurane requirements for loss of consciousness and skin incision by fentanyl was determined. Fentanyl reduced both requirements, but the mode of the reduction was not comparable.

Adult↗

Electroencephalographic derivatives as a tool for predicting the depth of sedation and anesthesia induced by sevoflurane.

BACKGROUND: The electroencephalogram (EEG) has been evaluated as a tool for measuring depth of anesthesia, but the use of the EEG monitoring is still controversial. The current study was designed to evaluate the accuracy of three EEG parameters and anesthetic concentration for predicting depth of sedation and anesthesia during sevoflurane anesthesia METHODS: One low and one high equilibrated concentration ranging from 0.2-1.8% were assigned randomly and administered consecutively to 69 patients. The bispectral index (BIS; version 3.2), 95% spectral edge frequency (SEF), and median power frequency (MPF) were obtained from a bipolar frontomastoid (Fp1-A1, Fp2-A2) montage using an EEG monitor. Sedation was assessed using the responsiveness portion of the observer's assessment of alertness-sedation scale. In the second phase of the study, the 47 patients who were scheduled to have skin incisions were observed for purposeful movement in response to skin incision at sevoflurane concentrations between 1.6% and 2.4%. The relation among BIS, 95% SEF, MPF, sevoflurane concentration, sedation score, and movement or no movement after skin incision, was determined. Prediction probability values for EEG parameters and sevoflurane concentration to predict depth of sedation and anesthesia were also calculated. RESULTS: The BIS and sevoflurane concentration correlated closely with the sedation score. Both 95% SEF and MPF changed significantly but biphasically with increasing sedation. The prediction probability values for BIS and sevoflurane concentration were 0.966 and 0.945, respectively, indicating a high predictive performance for depth of sedation. No EEG parameters predicted movement after skin incision better than chance alone. CONCLUSIONS: Parameters derived from EEG, such as BIS, and 95% SEF are reliable guides to the depth of sedation, but not to the adequacy of anesthesia level for preventing movement during sevoflurane anesthesia.

Adult↗

Computed tomographic findings in non-specific interstitial pneumonia/fibrosis.

The entity of non-specific interstitial pneumonia/fibrosis (NIP) has recently been recognized as an addition to the current classification of idiopathic interstitial pneumonia, which includes usual interstitial pneumonia, desquamative interstitial pneumonia, diffuse alveolar damage, and bronchiolitis obliterans organizing pneumonia. We studied the computed tomographic (CT) findings of nine NIP patients who were diagnosed pathologically. The main findings were ground glass opacities (66.7%), airspace consolidation (88.9%) and reticular opacities (89.7%), distributed predominantly in the bilateral and lower lung. In all cases, the clinical and abnormal opacification observed on the chest CT was improved by the administration of corticosteroid. Both the subpleural and patchy distributed opacifications predominantly in the bilateral and lower lung, and the good response to treatment may help to differentiate non-specific interstitial pneumonia from other types of idiopathic interstitial pneumonia.

Adult↗

Successful pregnancy after coronary artery bypass grafting for Kawasaki disease.

A 13-year-old girl with a history of Kawasaki disease underwent coronary artery bypass grafting because of angina pectoris due to a giant coronary artery aneurysm on the left main trunk artery. Nine years after the operation, the patient had an uneventful pregnancy followed by a normal vaginal delivery. This is the first case of a successful pregnancy after coronary artery bypass grafting for Kawasaki coronary artery disease.

Adolescent↗

Correlations among expression of intercellular adhesion molecule 1, cellular infiltration, and coronary arteriosclerosis during chronic rejection using the rat heart transplantation model.

Immunologic mechanisms contribute to the development of coronary arteriosclerosis. In this study the rat heart transplantation model was used to investigate correlations among the expression of intercellular adhesion molecule 1, cellular infiltrate, and coronary arteriosclerosis during chronic rejection. Lewis rats served as heart donors and F-344 rats as recipients. Heart transplantations were performed heterotopically. The recipients were treated with cyclosporin A (5 mg/kg/day) by daily intramuscular injection for 30 days, beginning on the day of transplantation. Rejection grade and the intimal area were measured. The expression of intercellular adhesion molecule 1 and the numbers of infiltrating CD4- and CD8-positive cells and macrophages were examined immunohistochemically. The area of the intima was significantly increased in the allograft group after transplantation. In the allograft group, the level of expression of intercellular adhesion molecule 1 was considerably increased over the same time period. There was increased cellular infiltration in the 60-day group, and many expressed intercellular adhesion molecule 1. The expression of intercellular adhesion molecule 1 in vascular endothelium, infiltrating cells, and the sarcolemmal membrane of myocytes remained constant up to 120 days in the allograft group. In the allograft group, the number of infiltrating CD4- and CD8-positive cells and macrophages increased significantly between 30 and 60 days, and the infiltration of these cells remained constant. Continuous expression of intercellular adhesion molecule 1 induces the infiltration of T cells and macrophages, and the inflammation caused by such cells and their soluble products contributes to the arteriosclerotic process.

Animals↗