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Biomedical subjects

T Kodama

Publications and source records attributed to T Kodama.

At least 613 records · Page 34Linked to original sources
PubMed1991

The influence of clinical use of antibiotics and the sensitivity of strains isolated from postoperative infections--a comparison of nosocomial pathogens with strains isolated from the bacterial flora of patients.

In the present study, we investigated how the recent clinical use of antibiotics have altered the antibiotic susceptibility of strains isolated from postoperative infections, especially Gram-negative rods. For Pseudomonas aeruginosa, serogroup E strains accounted for about 20 per cent of postoperative infections, but were unable to be isolated from either the feces of patients on admission or from the appendix contents of patients with appendicitis. It therefore appeared that serogroup E strains were responsible for the nosocomial infections in our department. The strains of methicillin-resistant Staphylococcus aureus and Pseudomonas aeruginosa serogroup E, which we assumed to be nosocomial pathogens, acquired a high level of resistance to antibiotics soon after third-generation cephems became widely used. On the other hand, the antibiotic susceptibility of Enterobacter cloacae, Citrobacter freundii, and the serogroups of Pseudomonas aeruginosa other than E, which were considered to originate from the bacterial flora of patients, did not vary throughout the several years of the study period.

Bacteria↗
PubMed1991

A case of HBs antigen negative fulminant hepatitis with IgM antibody to hepatitis B core antigen persisting more than seven years.

A 33-year old dentist developed fulminant hepatitis. At admission, a test for IgM antibody to hepatitis B core antigen (IgM anti-HBc) was positive, while tests for HBsAg and HBeAg were negative. He was cured of the disease, but in follow-up examinations from 1983 to 1990 IgM anti-HBc was continuously detected with radioimmunoassay while HBsAg and HBV-DNA were absent in the serum. However, HBcAg was found in a biopsied liver specimen and a small quantity of HBV-DNA was detectable by polymerase chain reaction assay. These observation suggest that the continuous detection of IgM anti-HBc without HBsAg in serum is due to persistent HBV infection and HBV replication in the liver.

Adult↗
PubMed1991

A case report of juvenile polyposis with adenomatous change and a review of 34 cases reported in Japan.

It has recently come to be thought that cases of juvenile polyposis have a natural tendency to develop adenoma and/or carcinoma. Here we present a case of juvenile polyposis coli with adenomatous change in a 21-year-old male, with a review of 34 cases of juvenile polyposis in the Japanese literature, and discuss the pathogenetic development of the polyps and their malignant potential. In this case, focal or entire adenomatous areas were found in large part of the polyps in the resected sigmoid colon and rectum, though these findings had not been recognized in 23 polypectomy specimens from the rectum 10 months prior to the operation. It was suggested that adenomatous change developed quickly in a very short time.

Adenocarcinoma↗
PubMed1991

Toxin involvement in methicillin-resistant Staphylococcus aureus enteritis in gastroenterological surgery.

The authors investigated the production of toxic shock syndrome toxin-1 (TSST-1) and staphylococcal enterotoxins (SE) by Methicillin-resistant Staphylococcus aureus (MRSA) isolates to clarify the pathogenesis of postoperative MRSA enteritis in patients undergoing gastroenterological surgery. Regarding the percentage of TSST-1 producing strains, there was a significant difference between type II MRSA strains (68.8%) and type IV MRSA strains (4.2%). Among type II strains, all those producing staphylococcal entorotoxin (SE) type C (SEC) also produced TSST-1, although other strains that produced SEB without TSST-1 were commonly isolated. Strains producing SEA were potent producers of SE which was considered to be responsible for enteritis. Therefore, we hypothesized that the strains which produced both SEA and SEC tended to cause enteritis associated with TSS-like symptoms owing to the high titer of these toxins.

Bacterial Toxins↗
PubMed1991

Comparison of reliability of plasma fructosamine and glycosylated hemoglobin assays for assessing glycemic control in diabetic patients on hemodialysis.

To search for a reliable marker of medium-term integrated blood glucose level in diabetics on maintenance hemodialysis (HD), plasma fructosamine and glycosylated hemoglobin (Hb) levels were determined every week and blood glucose levels were determined four times every day over 3 weeks. The mean values of fructosamine (mol/L per 40 g of albumin) and of glycosylated Hb of other the study period correlated (r = .746, P less than .001) for combined materials of diabetic and nondiabetic subjects. However, plasma fructosamine values at the end of the study period did not correlate with the overall mean blood glucose values during the preceding 8 to 21 days (r = .372, NS). In contrast, glycosylated Hb values correlated closely with the same mean blood glucose values (r = .703, P less than .001). Fructosamine values significantly decreased during a HD, irrespective of the increases in albumin and total protein. In conclusion, glycosylated Hb was a reliable marker of long-term integrated blood glucose even in diabetics on HD. However, fructosamine was not a reliable marker of medium-term integrated blood glucose in these patients.

Blood Glucose↗
PubMed1991

Chemomechanical coupling in actomyosin system: an approach by in vitro movement assay and kinetic analysis of ATP hydrolysis by shortening myofibrils.

On the basis of our recent studies of the sliding distance of actin filaments during one ATP cycle on the surface of myosin-coated glass surface and ATP hydrolysis by rapidly shortening myofibrils, the molecular mechanism of chemomechanical coupling is considered. We conclude that the myosin head can repeat many active cyclic interactions with actins to drive the actin filaments over a long distance during one ATP cycle, and that the distance is variable depending on the load.

Actomyosin↗
PubMed1991

Use of fluorescent electronic endoscopy in the evaluation of peptic ulcers.

Serial changes in the color tone of the mucosa after fluorescein administration in patients with peptic ulcers were evaluated using an electronic endoscope. In the healing and scar (S1) stage of a peptic ulcer, more intense fluorescence was observed in the lesion than in the surrounding normal mucosa shortly after intravenous injection of fluorescein. On processing of the electronic endoscopic fluorescent images using HSI transformation the difference between the lesion and normal areas could be clearly identified. This difference in the fluorescent image between the lesion and the surrounding normal mucosa may be associated with changes in the mucosal blood flow and cellular functions in the lesion. Fluorescent electronic endoscopy with fluorescein thus seems to be a useful technique for examination of the gastrointestinal mucosa.

Endoscopy, Gastrointestinal↗
PubMed1991

Crystallization and preliminary X-ray diffraction study of cytochrome c552 from Hydrogenobacter thermophilus.

Cytochrome c552 from a thermophilic hydrogen-oxidizing bacterium, Hydrogenobacter thermophilus, exhibits remarkable thermostability. The oxidized cytochrome c552 has been crystallized in an ethanol/water mixture by means of the vapor diffusion method. The crystals belong to the orthorhombic system, space group P2(1)2(1)2, with unit cell dimensions of a = 93.4 A, b = 52.9 A, and c = 32.4 A. Most probably the asymmetric unit contains two molecules of cytochrome c552. The crystals diffract X-rays to better than 2.5 A resolution and are stable to X-ray irradiation.

Bacteria, Aerobic↗
PubMed1991

Kinetics of adenosine triphosphate hydrolysis by shortening myofibrils from rabbit psoas muscle.

1. Using a solenoid-operated mixing device, time-resolved measurements were made of shortening and accompanying ATP hydrolysis at 20 degrees C by myofibrils prepared from rabbit psoas muscle. 2. The extent of ATP hydrolysis was determined by an improved Malachite Green method for determination of inorganic phosphate (Pi) in the presence of a large excess of ATP. For the measurement of the change in sarcomere length by phase contrast microscopy, shortening was terminated without delay and artifact by a mixture of 0.2 M-acetate (pH 4.6) and 1.25% (v/v) glutaraldehyde. 3. The shortening velocity per half-sarcomere was 10 microns s-1 in 25 mM-KCl for sarcomere lengths above 1.4 microns, and at least 12 microns s-1 in 150 mM-KCl for sarcomere lengths above 1.7 microns. During this rapid shortening, there was no significant ATP turnover by cross-bridges (upper 95% confidence limit: 0.14 mol (mol of myosin head)-1 in 25 mM-KCl; 0.12 mol mol-1 in KCl solutions greater than or equal to 100 mM). 4. When the sarcomeres shortened below 1.7 microns in KCl concentrations greater than 100 mM or below 1.4 microns in 25 mM-KCl, there was a transient acceleration of ATP hydrolysis (delayed ATP hydrolysis), which was then followed by a steady slow hydrolysis. 5. The magnitudes (+/- estimated standard deviation) of delayed ATP hydrolysis by myofibrils of initial sarcomere length 2.4 microns were 0.42 +/- 0.19, 0.31 +/- 0.10 and 0.17 +/- 0.09 mol (mol myosin head)-1 in 25 mM, 100 mM and 150 mM-KCl, respectively. For myofibrils of sarcomere length 2.0 microns, however, it decreased to 0.24 +/- 0.10 mol mol-1 in 25 mM-KCl or to an insignificant level in 150 mM-KCl. 6. These results indicate that most of the ATP hydrolysis products remain bound to cross-bridges during rapid shortening, and that when the force opposing shortening increases, a proportion of cross-bridges rapidly dissociate the products and enter the next ATP cycle, which diminishes with the decrease in shortening distance as well as the increase in ionic strength. Such behaviour of the cross-bridge is probably a manifestation of its energetic and kinetic properties in the state with bound ADP and Pi interacting with actin filaments at zero load and at a transition from zero to non-zero loads.

Adenosine Triphosphate↗
PubMed1991

Peptide sequences for sucrose splitting and glucan binding within Streptococcus sobrinus glucosyltransferase (water-insoluble glucan synthetase).

The gene encoding glucosyltransferase responsible for water-insoluble glucan synthesis (GTF-I) of Streptococcus sobrinus (formerly Streptococcus mutans 6715) was cloned, expressed, and sequenced. A gene bank from S. sobrinus 6715 DNA was constructed in vector pUC18 and screened with anti-GTF-I antibody to detect clones producing GTF-I peptide. Five immunopositive clones were isolated, all of which produced peptides that bound alpha-1,6 glucan. GTF-I activity was found in only two large peptides: one stretching over the full length of the GTF-I peptide and composed of about 1,600 amino acid residues (AB1 clone) and the other lacking about 80 N-terminal residues and about 260 C-terminal residues (AB2 clone). A deletion study of the AB2 clone indicated that specific glucan binding, which is essential for water-insoluble glucan synthesis, was lost prior to sucrase activity with an increase in deletion from the 3' end of the GTF-I gene. These results suggest that the GTF-I peptide consists of three segments: that for sucrose splitting (approximately 1,100 residues), that for glucan binding (approximately 240 residues), and that of unknown function (approximately 260 residues), in order from the N terminus. The primary structure of the GTF-I peptide, deduced by DNA sequencing of the AB1 clone, was found to be very similar to that of the homologous protein from another strain of S. sobrinus.

Amino Acid Sequence↗
PubMed1991

Strain-specific neutralizing determinant in the transmembrane protein of simian immunodeficiency virus.

Monoclonal antibody SF8/5E11, which recognizes the transmembrane protein (TMP) of simian immunodeficiency virus of macaque monkeys (SIVmac), displayed strict strain specificity. It reacted with cloned and uncloned SIVmac251 but not with cloned SIVmac142 and SIVmac239 on immunoblots. This monoclonal antibody neutralized infection by cloned, cell-free SIVmac251 and inhibited formation of syncytia by cloned SIVmac251-infected cells; these activities were specific to cloned SIVmac251 and did not occur with the other viruses. Site-specific mutagenesis was used to show that TMP amino acids 106 to 110 (Asp-Trp-Asn-Asn-Asp) determined the strain specificity of the monoclonal antibody. This strain-specific neutralizing determinant is located within a variable region of SIVmac and human immunodeficiency virus type 2 (HIV-2) which includes conserved, clustered sites for N-linked glycosylation. The determinant corresponds exactly to a variable, weak neutralizing epitope in HIV-1 TMP which also includes conserved, clustered sites for N-linked glycosylation. Thus, the location of at least one neutralizing epitope appears to be common to both SIVmac and HIV-1. Our results suggest a role for this determinant in the viral entry process. Genetic variation was observed in this neutralizing determinant following infection of a rhesus monkey with molecularly cloned SIVmac239; variant forms of the strain-specific, neutralizing determinant accumulated during persistent infection in vivo. Selective pressure from the host immune response in vivo may result in sequence variation in this neutralizing determinant.

Amino Acid Sequence↗
PubMed1991

Inhibitory effect of oral sorbent on accumulation of albumin-bound indoxyl sulfate in serum of experimental uremic rats.

Serum indoxyl sulfate, which is markedly accumulated in uremic patients, cannot be removed efficiently by hemodialysis due to its albumin binding. To determine if oral adsorbent (AST-120) can decrease its serum concentration in uremic state, oral adsorbent was administered to experimental nephrectomized uremic rats. Uremic rats fed with oral adsorbent showed a significantly lower serum concentration of indoxyl sulfate compared to control uremic rats, even when serum concentrations of urea nitrogen and creatinine were not significantly decreased in the uremic rats fed with oral adsorbent. Indoxyl sulfate was detected only at a lower concentration in bile as compared with the serum of uremic rats. These results suggest that oral adsorbent adsorbs indole, a precursor of indoxyl sulfate, in the intestine and prevents the accumulation of indoxyl sulfate in uremic rats.

Administration, Oral↗
PubMed1991

Prevalence of chondrocalcinosis in patients with primary hyperparathyroidism in Japan.

One hundred and thirty-two consecutive patients with primary hyperparathyroidism were studied preoperatively for the presence of chondrocalcinosis, the roentgenographic marker of calcium pyrophosphate dihydrate (CPPD) crystal deposition disease, by obtaining radiographs of knees, wrists and pelvis. Chondrocalcinosis was found in 8 patients (6.1%), each of whom was over 50 years of age. In 72 of the patients over 50 years of age, the prevalence of chondrocalcinosis in the hyperparathyroid patients (11.1%) was greater than that found in 72 control patients (2.8%) with thyroid nodular disease who were exactly matched for age and sex, but the difference was not significant. The prevalence of chondrocalcinosis in the hyperparathyroid patients sharply increased with age. In the group in their 50's it was 4.4%, rising to 15.8% in patients in their 60's and reaching 37.5% for those over 70 years of age. Patients with chondrocalcinosis were significantly older than those without this finding (p < 0.005). Those with chondrocalcinosis also had significantly higher preoperative serum calcium levels than those without it (p < 0.05). While chondrocalcinosis was detected by taking joint radiographs in all patients with primary hyperparathyroidism, acute arthritis (pseudogout attack) occurred in only 2 of the 132 patients (1.5%) after parathyroidectomy, but this represents 25% (2 of 8) of those who had chondrocalcinosis. An attack of pseudogout may therefore be one of the most common postoperative complications of parathyroid surgery in the elderly. Considering the low incidence of pseudogout attack following parathyroidectomy, preoperative radiological studies of the knee joints are sufficient to screen for chondrocalcinosis and are recommended for patients over 60 years old in Japan.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1991

Hyperinsulinemia and blood pressure in non-obese middle-aged subjects with normal glucose tolerance.

A possible link between hyperinsulinemia and blood pressure was studied in non-obese subjects with normal glucose tolerance. First, the responses in plasma glucose and serum insulin to an oral glucose load (75-g oral glucose tolerance test) were compared between 42 patients with essential hypertension and 93 normotensive control subjects. Second, of the 93 normotensive subjects, the relations of serum insulin levels to blood pressure, serum cholesterol, and triglycerides concentrations were assessed in 8 hyperinsulinemic (serum insulin level [during fasting, or after glucose loading, or both] greater than 2 S.D. higher than the mean) and 8 pair-matched normoinsulinemic subjects (serum insulin level within 1 S.D. of the mean), individually matched for age, sex, and body mass index. Plasma glucose and serum insulin responses to the glucose load in hypertensive subjects were identical to the respective responses in normotensive subjects, while the mean total serum cholesterol level was slightly higher (p less than 0.05) in hypertensive subjects. The respective values for systolic and diastolic blood pressures, and total serum cholesterol and triglycerides concentrations were comparable in hyperinsulinemic and normoinsulinemic subjects. These results did not suggest a close association between hyperinsulinemia and elevated blood pressure in non-obese middle-aged Japanese subjects with normal glucose tolerance.

Blood Glucose↗
PubMed1991

Tissue distribution, intracellular localization, and in vitro expression of bovine macrophage scavenger receptors.

Macrophage scavenger receptors are trimeric membrane proteins implicated in the pathologic deposition of cholesterol in atherogenesis. The authors have studied the tissue distribution and intracellular localization of bovine scavenger receptors using monoclonal antibovine receptor antibody IgG-D2. The receptor proteins were detectable in macrophages of various organs and tissues, particularly Kupffer cells, alveolar macrophages, and macrophages in the spleen and lymph nodes. In the brain, perivascular macrophages were immunoreactive with IgG-D2. Fibroblasts, endothelial cells, smooth muscle cells, and dendritic cells such as epidermal Langerhans cells, interdigitating cells, or follicular dendritic cells, however, showed no immunoreactivity to IgG-D2. Immunoelectron microscopy showed localization of reaction products for these receptors on the cell surface, vesicles, and endosomes of macrophages. Transient expression of bovine scavenger receptors on cultured cells shows that scavenger receptors are mainly expressed in the endoplasmic reticulum, nuclear envelope, and Golgi apparatus of nonmacrophage cells and moved to the cell surface and endosomes of macrophagelike cells. These results indicate that efficient intracellular transport of scavenger receptors in macrophages is mediated by a macrophage-specific transport system.

Acetic Anhydrides↗
PubMed1991

[Lens crystallin leakage in aqueous humor from human cataractous lenses].

The amounts of human lens crystallins in the aqueous humor from various types of cataract patients were measured by radioimmunoassay. alpha, beta and gamma-crystallins as antigens for radioimmunoassay were purified from one-year-old normal human lens by TSK3000SW gel permeation column using high performance liquid chromatography. The amounts of both alpha- and gamma-crystallin in the aqueous humor from the patients with cortical and posterior subcapsular cataract were relatively low but in the case of mature cataract those of both crystallins increased. While the amounts of beta-crystallin in aqueous humor from cortical and posterior subcapsular cataract patients were at the same level compared with alpha-crystallin, those from mature cataract patients showed extremely high values.

Aged↗