Biomedical subjects
Publications and source records attributed to T Shoji.
We describe a method for continuously recording the stabilized His bundle electrogram from the aortic root during open heart surgical procedures. This simple technique was useful in all surgical procedures for the oblation of supraventricular tachyarrhythmias in the region around the atrioventricular conduction system.
We sought to determine whether artherosclerosis may be accelerated in uremic patients on maintenance hemodialysis and investigated the risk factors for carotid and femoral atherosclerosis in such patients. High-resolution B-mode ultrasonography was used to determine the intima-media thickness (IMT) of the carotid and femoral arteries in 199 hemodialysis patients and 81 age-matched healthy controls subjects. The IMT values of the carotid and femoral arteries in the hemodialysis patients were significantly higher than in age-matched control subjects in most age groups. The IMT values of the carotid or femoral artery were significantly correlated with age in both the hemodialysis patients and the control subjects. There was a significant relationship between the IMT values of the two arteries in the hemodialysis patients (r = 0.418, P = 0.0001) and in the control subjects (r = 0.321, P = 0.0037). Multiple regression analysis showed that age, cigarette smoking, and uremic state were independent risk factors for atherosclerosis of both arteries in the patients and the control subjects (R2 = 0.174, P < 0.0001; R2 = 0.205, P < 0.0001, respectively). In the hemodialysis patients, the independent risk factors associated with the extent of the IMT of the carotid artery were age, cigarette smoking, and serum phosphorus level (R2 = 0.230, P < 0.0001), while those associated with the extent of the IMT of the femoral artery were age, cigarette-smoking, and serum m-PTH level (R2 = 0.230, P < 0.0001).(ABSTRACT TRUNCATED AT 250 WORDS)
Small caliber biological grafts that were heparinized and nonheparinized were implanted in 52 patients with arterial obstructive disease and chronic renal failure by either conventional suture anastomosis or laser anastomosis over the last 8 years. There were no operative mortalities. The overall postoperative patency rate was 91% at 1 year, 85% at 3 years, and 82% at 5 years. The heparinized graft anastomosed by laser clearly had the best results with a 100% patency rate at 5 years without pathological anastomotic intimal hyperplasia. Therefore, the heparinized biological graft anastomosed by laser could be the best option for the reconstruction of small vessels although these grafts might be clinically useful for small caliber grafts.
Intraoperative perfusion contrast echocardiography (PCE) is a new method to evaluate regional myocardial perfusion using Albunx (air encapsulated albumin microspheres-Molecular Biosystems, Inc.) and has been employed by direct individual injection into human saphenous vein coronary bypass grafts. Because this is not an appropriate technique for assessing left internal thoracic artery (LITA) graft, we tested the hypothesis that PCE can be performed with a single aortic root injection and, thereby, provide regional perfusion data for LITA and native coronary flow. CABG (LITA to the left anterior descending artery (LAD) was performed in adult swine. PCE was performed in each of the following conditions: 1) LITA occluded, LAD 100% flow; 2) LITA 100% flow, LAD occluded; 3) LITA 50% flow, LAD occluded; and 4) LITA and LAD occluded. Time-intensity curves were constructed to assess the time to initial appearance of myocardial enhancement (TIA), peak contrast intensity (PI), and area under the enhancement curve (AUC). In 12/14 cases, (85.7%), adequate enhancement was achieved. LITA perfusion, when compared to perfusion through the native LAD, showed delayed appearance (TIA 0.4 +/- 0.1 vs 1.9 +/- 0.2 secs), reduced PI (43 +/- 3 vs 28 +/- 3 AU) and reduced AUC (247 +/- 115 +/- 19 AU) (p < 0.01) when LITA flow was reduced 50%, TIA was prolonged (1.7 +/- 0.2 vs 2.4 +/- 0.2 secs) and AUC was reduced (152 +/- 18 vs 88 +/- 20 AU) (p < 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)
Elevated plasma intermediate density lipoprotein (IDL) is one of the features of uremic dyslipidemia which is potentially atherogenic. We examined the effects of pravastatin, an HMG-CoA reductase inhibitor, on IDL levels as well as other lipoprotein parameters in 19 uremic patients treated with hemodialysis (HD, n = 11) or continuous ambulatory peritoneal dialysis (CAPD, n = 8). The patients were administered 5 mg/day pravastatin for the initial 4 weeks and 10 mg/day for the subsequent 12 weeks. In the analysis of the total subjects, IDL-cholesterol was reduced by 31% as well as low density lipoprotein (LDL)-cholesterol. Cholesterol in very low density lipoprotein (VLDL) also decreased whereas that in high density lipoprotein (HDL) did not. Significant decrease of serum triglycerides was due mainly to reduced IDL- and LDL-triglycerides. Apolipoprotein (apo) A-I did not change, whereas apo A-II, B, C-II, C-III, E, and B/A-I ratio were significantly lowered. Pravastatin did not affect measured activity of lecithin: cholesterol acyltransferase, post-heparin plasma lipoprotein lipase or hepatic triglyceride lipase. HD and CAPD patients responded almost equally to the treatment. IDL elevation was present independent of serum total cholesterol, and it was lowered by pravastatin even in non-hypercholesterolemic subjects. There was no critical adverse effect besides transient and asymptomatic increase of serum creatine kinase level. We conclude that pravastatin can be a safe and effective approach to the management of dyslipidemia in uremic patients who have an elevated level of IDL.
A Twin Impinger was used to assess the influence of the number of puffs on the distribution patterns of two commercially available beclomethasone dipropionate (BDP) metered dose inhalers, and the effects of two kinds of spacer devices were also compared. No difference was observed in the distribution pattern up to the 10th puff between the two metered dose inhalers. Clinically, the amount of BDP inhaled into the lungs is said to depend on the number of puffs taken, but in this study, there was a significant difference in the distribution pattern between these 2 inhalers. In the stage assumed to represent the oropharynx site, the distribution ratio of BDP was greater after administration with an Aldecin than with a Becotide inhaler. In contrast, in the stage assumed to represent the lung, the distribution ratio of BDP was greater with the Becotide inhaler. This result suggests that the amount of BDP inhaled in the lungs may vary between these two preparations. The effects of spacer devices were also investigated in 4 puffs. These spacer devices caused the distribution ratio in the stage assumed to represent the oropharynx to decrease by at least 90%, irrespective of the type of metered dose inhaler. This result suggests that spacer devices are useful in reducing local side effects in the oropharynx. In the stage assumed to represent the lung, the distribution ratio achieved with the Becotide inhaler with Volumatic was greater than that with the Aldecin with InspirEase. This study suggests that the best therapeutic effects can be expected from a combination of Becotide inhaler and Volumatic.
The olfactory responses of the aquatic turtles, Geocylemys reevesii whose nostrils are closed underwater to nonvolatile substances were measured by recording the olfactory bulbar responses. Various salts, acids and bitter substances elicited large responses, while sugars and amino acids did not elicit the responses. The thresholds for the salts were much lower than those of corresponding salts in the rat gustatory system. The responses to the salts were partially suppressed by amiloride. Various acids induced large responses and the magnitudes greatly depended on the anion species. The thresholds for the bitter substances were much lower than those of corresponding substances in the taste systems. Similar to the responses in taste systems, both electrostatic and hydrophobic interactions contribute to the binding of the substances to the receptor membranes. Similar to the taste systems, the response to quinine hydrochloride showed a sharp temperature dependence having a peak around 25 degrees C, while the responses to odorants did not show such peak. The present results suggest that the olfactory system has similar abilities to respond to salts, acids and bitter substances to those in gustatory systems and that the high sensitivity of the olfactory system to chemical stimuli is not only attributable to the second messenger amplification system, but also to the basic property of the receptor membrane independent of the amplification system.
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A series of sulfated alkyl oligosaccharides, including a sulfate dodecyl laminarapentaoside and a sulfated octadecyl maltohexaoside with potent anti-human immunodeficiency virus (HIV) activity, has been synthesized. An alkyl oligosaccharide in which a long alkyl group is bonded to the reducing end of the oligosaccharide was first synthesized in high yield. Peracetylated oligosaccharides reacted with such aliphatic alcohols as 1-decyl and 1-dodecyl alcohols with Lewis acids as catalysts. As in the glycosylation of the alpha and beta peracetylated glycosides, the beta anomer reacted exclusively, the acetylation was carried out with a sodium acetate-acetic anhydride at high temperatures to maximize the proportion of the beta anomer.
We studied the outcomes of 116 patients with hepatocellular carcinoma (HCC) diagnosed in our hospital between January 1980 and August 1992. The patients were divided into groups according to the principal treatment procedure. The 3-year survival rates in the patients treated by percutaneous ultrasonically guided ethanol injection (PEI), operation (hepatic resection), and transcatheter hepatic arterial embolization (TAE) were 90.9%, 53.6%, and 29.0%, respectively. None of the patients treated by one-shot injection of an anticancer agent into the hepatic artery and chemotherapy survived for more than 2 years. The outcomes of the patients treated by PEI and hepatic resection were significantly better than those of the patients treated by the other procedures. There was no significant difference when the patients were stratified according to the year of detection. The 3-year survival rate was 57.3% for 19 patients in whom HCCs were detected during clinical follow-up for chronic liver disease and 17.3% for the other 97 patients. We concluded that hepatic resection in patients with good liver function and PEI for early HCC yielded significantly better survival rates than the other procedures. Moreover, for early detection and treatment of HCC, we recommend clinical follow-up of patients with chronic liver disease.
A 14-year-old asymptomatic boy was admitted to our department for investigation of a diastolic murmur which had been discovered by his family doctor during a routine examination. Echocardiography showed aortic regurgitation with dilatation of the left ventricle. Inspection of the aortic valve at the time of operation revealed normal left and right cusps with a rudimentary noncoronary cusp. An aortic commissuro-plication was performed and a new bicuspid aortic valve successfully reconstructed. His postoperative course was uneventful and he has been well and leading an active life since his discharge from hospital.
The receptor mechanism of bitter substances was discussed from the following points of views. (a) Both electrostatic and hydrophobic interactions of bitter substances with taste receptor membranes contribute to reception of bitter substances having a positive charge. (b) In the frog, the responses to bitter substances are easily adapted. The presence of Ca ion in the medium prolongs the responses. (c) Bitter substances elicit electrical responses in nongustatory cells such as neuroblastoma cells and olfactory cells, suggesting that bitter substances induce the response by nonreceptor-mediated mechanism. (d) There is also a possibility that receptors for some bitter substances are G-protein coupled. We cloned G-protein coupled receptors from bovine taste tissues. (e) A specific inhibitor of bitter taste has been desired in pharmaceutical and food sciences, but it has not been available. We found that a lipoprotein made of phosphatidic acid and beta-lactoglobulin selectively inhibits the responses to bitter substances in the frog and humans. Binding of the lipoprotein to the receptor sites for bitter substances leads to suppression of the response.
In chum salmon captured at the coastal sea and the natal river, the magnitudes of the olfactory nerve responses to the amino acids after perfusion of the olfactory epithelium with artificial pond water (APW) were similar to those after perfusion with artificial sea water (ASW), although the concentrations of Na+, Cl- and Ca2+ in ASW were 986, 430 and 27 times higher than those in APW, respectively. The findings suggest that the permeability of these ions across the apical membranes of olfactory cells do not essentially contribute to the transduction mechanism in the salmon.
The major problems with existing centrifugal pumps are leakage, mechanical trauma, and thrombus formation. In consideration of these problems, a new compact centrifugal pump system was developed. The purpose of this study was to evaluate the new centrifugal pump system clinically. Ten patients underwent open heart surgery with a centrifugal pump or a roller pump. During surgery, hemodynamic and hematological data were obtained. A pulsatile assist device in the pump circuit was used in patients with severe heart disease. There was neither operative death nor hospital mortality, and there was no difference with regard to hemodynamic data between the two groups. The centrifugal pump groups, however, had significantly lower hemolysis, especially during prolonged cardiopulmonary bypass. This centrifugal pump could also create sufficient pulsatile flow with a pulsatile assist device. Postoperative macroscopic and microscopic findings demonstrated the smooth surface of the pump without thrombus formation. This centrifugal pump system might be useful for prolonged cardiopulmonary bypass.
Synthesis of 3-alkylamino-1,4-naphthoquinone-2-carboxylic acid (2) was attempted. Although 3-(1-piperidinyl)-1,4-naphthoquinone-2-carboxylic acid (2a) was not obtained, probably because of its instability, the esters (18a, b) of 2a could be prepared. 2-Alkylamino-3-hydroxymethyl-1,4-naphthoquinones (9a-g) were photochemically cyclized to the 1,4,5,10-tetrahydro-5,10-2H-naphth[2,3-d][1,3]oxazines (19a-g), containing a novel heterocyclic ring system in moderate yields. Anti-bacterial activity of the prepared compounds was weak or insignificant.
Streptomyces ATP nucleotide 3'-pyrophosphokinase is an extracellular enzyme that transfers 5'-beta, gamma-pyrophosphoryl groups of ATP to a variety of nucleotides at the 3'-OH site. The enzyme gene was cloned from partially Sau3AI-digested chromosomal DNA of S. morookaensis in S. lividans TK24/pIJ699 and then in E. coli JM83/pUC12. Some transformants produced the active enzyme. The gene was sequenced by the dideoxynucleotide termination procedure. Its GC content was 72%. Its putative promoter regions, showing little homology to that of the Streptomyces consensus type, were pointed out. No sequence homology was found between the pyrophosphokinase and any other known genes including those of the most mechanistically similar bacterial stringent factor and related proteins. Northern hybridization analysis showed that the gene is constitutionally polycistronic and expressed under transcriptional control. Nuclease S1 mapping indicated that the gene transcription starts from its translation initiation site.
Neuroblastic tumor cases in our departments were evaluated in terms of the stage of the tumor, N-myc amplification, urinary vanillylamndelic acid (VMA)/homovanillic acid (HVA) and survival rate. Two asymptomatic cases, diagnosed when under a year old by mass screening, had no amplifications of N-myc but showed more than one value of urinary VMA/HVA ratio. The patients are now doing well eight years after complete excision of the neuroblastoma which had originated in the sympathetic ganglion. On the other hand, two other symptomatic cases, operated on at the ages of 3 and 5 years, showed remarkable amplifications with less than one value of urinary VMA/HVA, and died from the tumor soon after partial resection of the neuroblastoma and ganglioneuroblastoma which had originated in the adrenal gland and the sympathetic ganglion, respectively. The present monograph reports our cases and discusses prognostic factors.
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