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Biomedical subjects

T Katoh

Publications and source records attributed to T Katoh.

At least 235 records · Page 13Linked to original sources

Detection of subependymal veins using high-resolution magnetic resonance venography.

High-resolution magnetic resonance venography (HR-MRV) of intracranial subependymal veins using a two-dimensional Fourier-transform time-of-flight technique was performed on normal volunteers and clinical cases of cerebral disease. For the pulse sequence, fast-field-echo sequence was used with the following parameters: TR/TE/flip angle = 34 ms/12 ms/50 deg., 256 x 256 matrix, 1 mm effective slice thickness, 150 mm field of view, and one signal acquisition. Sequential vertical coronal sections were taken against the skull base. The anterior septal vein, the medial atrial vein, the anterior caudate vein and thalamostriate vein were detected in all subjects. In all clinical cases, HR-MRV was equal in diagnostic capability to conventional cerebral angiography.

Adult↗

Use of fluid-attenuated inversion recovery (FLAIR) pulse sequences for differential diagnosis of hepatic hemangiomas and hepatic cysts.

Fluid-attenuated inversion recovery (FLAIR) imaging of hepatic hemangiomas (10 patients, 16 lesions) and hepatic cysts (8 patients, 10 lesions) was performed. All hemangiomas were hypointense on T1-weighted images and hyperintense on T2-weighted images. With Gd-DTPA (0.1 mmol/kg), all hemangiomas were enhanced but not all cysts. It was necessary to perform contrast enhanced imaging to differentiate hepatic hemangiomas from hepatic cysts. However, on FLAIR imaging, hepatic hemangiomas were strongly hyperintense and 9 of the 10 hepatic cysts were isointense. One of the hepatic cysts was slightly hyperintense. FLAIR images were useful in differential diagnosis of hepatic hemangiomas and hepatic cysts without using Gd-DTPA.

Cysts↗

[Investigation of the usefulness of CYFRA 21-1 as a tumor marker in squamous cell carcinomas of the head and neck].

It has been demonstrated that CYFRA 21-1 (ELISA kit), which recognizes the soluble cytokeratin 19 fragment, is useful for assessing circulating tumor antigens in sera of patients with lung cancer. In this study, we compared the clinical significance of this new marker with the established squamous cell carcinoma antigen (SCC Ag), using sera from patients with head and neck malignant disease, healthy controls, and supernatants of established cell lines derived from squamous cell carcinomas and adenocarcinomas. The subjects were: Group A, 39 patients with malignant disease of the head and neck. Group B, 11 patients considered to be tumor-free after treatment. Group C, 67 patients with benign disease or healthy volunteers. Culture supernatants: 11 cell lines established from squamous cell carcinomas and adenocarcinomas. Serum levels of CYFRA 21-1 and SCC Ag of group A were significantly higher than those of group C. This finding suggests that CYFRA 21-1 is useful as a tumor marker as well as SCC Ag. CYFRA 21-1 and SCC Ag levels of patients in group A at the early and progressive stages of disease were comparable to the levels in group C. Both tumor markers are therefore useful for diagnosis of in the early stage of cancer. We attempted to set a cut-off level of CYFRA 21-1. The sensitivity of CYFRA 21-1 is higher than that of SCC Ag, especially in patients in the early stage of the disease. This finding indicates that the CYFRA 21-1 is preferable to SCC Ag as a tumor marker for the diagnosis of patients even in the early stages of malignant disease. The levels of CYFRA 21-1 in culture supernatants derived from tumor cell lines are higher than those of SCC Ag in all cell lines. The levels of CYFRA 21-1 are measurable, with levels varying with the cell line. There appears to be no correlation between the level of CYFRA 21-1 and the character of the cell lines, but this issue remains to be further investigated.

Adult↗

A comparison of young and aged populations for the diphtheria and tetanus antitoxin titers in Japan.

The antitoxin levels for diphtheria and tetanus were measured with samples of a young group immunized with diphtheria-tetanus-acellular pertussis combined vaccine and those of an aged group, members of which had not received vaccination in their youth. In the young group members of which had already received basic immunization with diphtheria-tetanus-acellular pertussis combined vaccine, the levels of both antitoxins rose well after injection at 11 to 12 years old with diphtheria-tetanus combined toxoids and remained high until 20 years of age. In the aged group, more than 80% showed antitoxin levels above 0.01 u/ml for diphtheria, while all had levels below that for tetanus, except three persons with confirmed tetanus immunization history. Maintenance of the protective antitoxin levels in the population by vaccination is necessary to prevent outbreaks of infection among unvaccinated or only partially immunized persons.

Adolescent↗

Crosslinking of telokin to chicken gizzard smooth muscle myosin.

Telokin, which is a candidate for one of the factors stabilizing dephosphorylated myosin filaments in smooth muscle cells, was subjected to a chemical crosslinking study to determine its binding location on the myosin molecule. Telokin labeled with 5-iodoacetamidofluorescein (Fl-telokin) retained the nature of unlabeled telokin: it bound to dephosphorylated gizzard myosin with a stoichiometry of 1 mol/mol myosin and induced filament assembly. The carboxyl groups of Fl-telokin were activated with 1-ethyl-3-(3-dimethyl-amino-propyl) carbodiimide and N-hydroxysuccinimide and then crosslinked to myosin. The production of three fluorescent peptides was observed on an SDS-gel, accompanying a decrease in the amount of regulatory light chain (LC20). The molecular weights of these products estimated to be > 200, 62, and 41 kDa. When unlabeled telokin was crosslinked to myosin of which LC20 was exchanged with 5-[[2-[(iodoacetyl)amino]ethyl]amino]-naphthalene-1-sulfonic acid-labeled LC20, the 62- and 41-kDa bands were also fluorescent. These results suggest that the > 200, 62, and 41-kDa species are telokin crosslinked with a heavy chain, with 2 LC20, and with 1 LC20, respectively. Myosin crosslinked with unlabeled telokin showed an extra structure with a small projection at the head-rod junction on electron microscopy and this structure was proved to be telokin by decorating it with anti-telokin antibodies. In addition, dephosphorylated myosin crosslinked with Fl-telokin was incapable of folding into the 10S conformation at 0.2 NaCl in the presence of MgATP, and assembled into filaments at 0.15 M NaCl in the presence of MgATP. Thus, telokin may bind to LC20 and a heavy chain region at the head-rod junction and suppress folding into the 10S conformation, leading to the assembly of myosin into filaments.

Adenosine Triphosphate↗

[Ambulatory ECG].

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Arrhythmias, Cardiac↗

Higher prevalence of Borna disease virus infection in blood donors living near thoroughbred horse farms.

It is believed that Borna disease virus (BDV), an etiological agent of progressive polioencephalomyelitis in horses and sheep, is closely associated with psychiatric disorders in humans since the prevalence of BDV is higher in psychiatric patients than in blood donors. We investigated whether or not BDVs in humans are derived from infected domestic animals, by characterizing the BDVs in blood donors and horses derived from the same region of Hokkaido island, Japan. The seroprevalences (2.6 to 14.8%) of BDV were significantly higher in the blood donors from four regions where most horse farms are concentrated, compared with only 1% in the blood donors from Sapporo, the largest city in Hokkaido.BDV RNA was also detected in peripheral blood mononuclear cells from most of the seropositive horses and blood donors by nested reverse transcriptase-polymerase chain reaction. These findings support that BDV may be horizontally transmitted, at least in part, from infected horses to humans.

Animals↗

[Construction of pulmonary time-volume curve using MR: comparison with lung volume measurements using CT].

This study was conducted to investigate the effectiveness of dynamic pulmonary ventilation using MR and to compare it with lung volume measurements using CT. MR images during tidal breathing and CT images at resting expiratory level were obtained in 7 normal volunteers. The correlation between lung volume using CT and that using MR at resting expiratory level was significant (r = 0.993, p < 0.001). Pulmonary time-volume curves for each lobe were constructed by applying a Fourier series. The technique used in this study appears to be potentially useful to assess lobar lung function non-invasively and quantitatively.

Adult↗

Immunohistochemical localization of latent transforming growth factor-beta binding protein in IgA nephropathy.

It has been demonstrated that cultured mesangial cells (MC) express latent transforming growth factor (TGF)-beta binding protein (LTBP) mRNA, and that LTBP might be essential for the extracellular matrix (ECM) accumulation stimulated by TGF-beta in cultured MC. We performed a study to test the pathophysiological role of LTBP in mesangial ECM accumulation in human glomerulonephropathies. The expression of LTBP in 64 renal biopsies of patients with renal diseases was examined by immunohistochemical staining with the specific antibody raised against human LTBP. The biopsy specimens were divided into three groups: Group 1, IgA nephropathy; Group 2, IgA negative mesangial proliferative glomerulonephritis, which mainly consisted of diabetic nephropathy and lupus nephritis; and Group 3, non-proliferative nephropathy, which consisted of minimal change and membranous nephropathy. Immunohistochemical staining of LTBP was significantly detected in mesangial/paramesangial area of glomerulus in Group 1, but not observed in Group 2 or Group 3. The intensity of staining was well related to the grade of mesangial ECM accumulation in Group 1. These findings suggest that the LTBP-TGF-beta complex may play a pivotal role in ECM accumulation in IgA nephropathy, and that modification of LTBP-ECM interaction might provide a new therapeutic strategy against the progression of glomerulosclerosis.

Carrier Proteins↗

[Influence of cardiopulmonary bypass on lymphocyte function].

It is known that lymphocyte function is impaired after cardiopulmonary bypass (CPB). In this study, the lymphocyte stimulation test (LST) with PHA was used before and after CPB in 28 adult patients, and compared with the surgical parameters and serum cytokine (IL-6, IL-8) levels. LST was impaired after CPB in all patients. Although this value usually recovered by the third postoperative day (POD); (normal group, n = 16), some patients showed prolonged duration of the impaired LST (delayed group, n = 12). Therefore, the parameters of surgery, white blood cell (WBC) count, lymphocytes and subsets, and serum cytokine levels were compared between the normal and the delayed groups. There was no significant difference in the number of WBCs or lymphocytes between these two groups. OKT4-positive cells were reduced on the first POD in both groups, and in the normal group, the number of OKT4-positive cells recovered more quickly than in the delayed group. Serum IL-6 and IL-8 levels in the delayed group were elevated after CPB, and were significantly higher in the delayed group than in the normal group. In conclusion, patients who showed prolonged impairment of lymphocyte function may be partly due to prolonged CPB.

Adult↗

Recent therapeutic strategy for sustained ventricular tachycardia in Japan.

We investigated the therapeutic principles and strategies to treat sustained ventricular tachycardia (SVT) as five leading medical institutions in the Tokyo area and summarized the present situation of SVT treatment in Japan. Catheter ablation (ABL) has been almost established to be effective in idiopathic ventricular tachycardia (IVT) and was used as the last treatment in 60.3% of IVTs in this series. ABL may be the first option of therapy for IVT. In patients with SVT who have underlying cardiac diseases, the last treatment was class I drugs in 8.3%, class III drugs in 34.3%, combination drug therapy in 24.0%, ABL in 33.3%, surgical therapy (SUR) in 7.3%, and implantable cardioverter defibrillator (ICD) in 12.5% (nonpharmacological therapy in combination with other therapy). The use of class I drugs was not common, whereas class III drugs were used more frequently in patients with a low left ventricular ejection fraction. In some patients with reduced cardiac function, a combination of class III drugs and non-pharmacological therapy is appropriate.

Adult↗

[Helical CT for lung-cancer screening: fifth report: evaluation of image quality at low-dose CT using healthy volunteers].

In order to reduce radiation dose in the application of CT for lung-cancer screening, we investigated the potential of low-dose screening helical CT (SHCT) by reducing the tube current and using an additional 10 mm aluminum filter. Six healthy volunteers were scanned at various tube currents (50 mA, 30 mA, 20 mA) with and without the filter. In comparison with the images at 50 mA without the filter, we evaluated the visualization of normal anatomical structures and the detection of simulated nodules at low-dose SHCT. Although a bias toward unclearness in the visualization of small anatomical structures was noted at 20 mA with use of the filter, no structure was assessed as having no visualization at any low-dose scan. Detection of simulated nodules was not degraded significantly by reducing the tube current to 20 mA and using the filter. Further reduction of radiation dose at SHCT may be achieved by the application of small tube current and an additional filter.

Female↗

[Pharmacokinetic and clinical studies with cefluprenam in the pediatric field. Pediatric Study Group of Gefluprenam].

Evaluation of efficacy and safety of cefluprenam (code number: E1077, abbreviation: CFLP), a newly developed injectable cephem antibiotics was conducted on adult patients with various infections, and followed by the study group organized from 39 institutions in pediatric field, as the drug showed no toxicity problems in suckling animals. Informed consents from legal representatives were obtained prior to the study. 1. Clinical efficacy. Two-hundred eighty one cases were included for analysis of clinical efficacy after 40 cases of exclusion or drop-out were subtracted from a total of 321 cases. However, the cumulative number of cases evaluable for analysis was considered to be 289, because 8 cases that had 2 different diseases at the same time were counted in each category of disease. In the cases in which causative organisms were identified (group A), 148 of 154 cases were rated as good or excellent, with an efficacy rate of 96.1%. As for clinical efficacies by disease, efficacy rates were 6/6 for purulent meningitis, 4/5 for sepsis, 95.7% (62/65) for pneumonia, 100.0% (29/29) for urinary tract infections, and 94.1% (16/17) for skin and soft tissue infections. The rate of excellent responses among excellent and good responses was 73.6% (109/148), showing a higher value than any of recent injectable beta-lactams. On 32 cases with S. pneumoniae infection, the efficacy rate of CFLP was 100.0%. In the cases where causative organisms were not identified (group B), 128 of 135 cases were rated as good or excellent, with an efficacy rate of 94.8%. In the all cases including both the group A and the group B, the efficacy rate was 95.2% (276/289) and the rate of excellent responses among excellent and good response was 70.7% (195/276). Against severe infections, CFLP exhibited excellent clinical efficacy, showing an efficacy rate of 8/8 for meningitis, 3/5 for sepsis and 100.0% (22/22) for severe pneumonia. As for bacteriological responses, eradication rates were 95.2% (177/186) in total. Against Gram-positive cocci, the eradication rate was 92.7% (76/82), with eradication rates of 94.3% (33/35) for Staphylococcus aureus, and 93.3% (28/30) for Streptococcus pneumoniae. Against Gram-negative rods, the eradication rate was 97.1% (101/104), and eradication rates were 100.0% (22/22) for Escherichia coli, 97.5% (39/40) for Haemophilus influenzae and 100.0% (19/19) for Molaxella catarrhalis. In cases in which more than 3 days of treatment with previous chemotherapy resulted in no response, the efficacy rate of CFLP was 94.2% (98/104), rated excellent in 68 cases and good in 30 cases. In these cases, the eradication rate was 98.1% (52/53). 2. Pharmacokinetics. CFLP was intravenously administerrd to 12 subjects at doses of 20 to 40 mg (potency)/kg. In 9 subjects aged more than 12 months, maximum serum levels (Cmax), T 1/2 beta and AUC of CFLP were 155.3 +/- 9.8 micrograms/ml, 1.43 +/- 0.18 hours and 111.7 +/- 15.0 micrograms.hr/ml, respectively, when a dose of 20 mg (potency)/kg was used. In 2 subjects aged not more than 12 months, the mean Cmax, T 1/2 beta and AUC were 153 micrograms/ml, 1.6 hour and 81 micrograms.hr/ml, respectively, at a dose of 20 mg(potency)/kg. The mean Cmax, T 1/2 beta and AUC were 332 micrograms/ml, 0.93 hours and 157.3 micrograms.hr/ml, respectively, in 1 subject at a dose of 40 mg (potency)/kg. In 10 subjects dosed 20 mg (potency)/kg, urinary levels were 2413 +/- 512, 1471 +/- 524, and 470 +/- 115 micrograms/ml in 0-2, 2-4, and 4-6 hours after dosing, respectively, showing a cumulative urinary excretion rate of 61.4 +/- 6.3%. In 1 subject dosed 40 mg (potency)/kg, urinary levels were 5700 and 4770 micrograms/ml in 0-2 p3d 2-4 hours after dosing, respectively, showing a cumulative urinary excretion rate of 42.1%. Cerebrospinal fluid concentrations of CFLP, on 10 subjects with purulent meningitis dosed 40-103 mg (potency)/kg were 3.2-32.9 micrograms/ml at 0.5-2 hours after administration within 4 days after the onset of

Bacteria↗

Roles of light chains in the activity and conformation of smooth muscle myosin.

The 20-kDa regulatory (LC20) and 17-kDa essential (LC17) light chain subunits could be removed from porcine aorta smooth muscle myosin by the use of trifluoperazine and ammonium chloride. The isolated heavy chain rebound both light chains, resulting in the restoration of native properties. Experiments on reconstitution of the isolated heavy chain with LC17 and/or LC20 showed that both light chains were required for folding into the 10 S conformation and thus for the phosphorylation-dependent filament formation of smooth muscle myosin. However, LC17 was not essential for the phosphorylation-dependent regulation of actin-activated ATPase activity and superprecipitation but was required for full regulation. LC17 and phosphorylated LC20 were found to act as activators, and dephosphorylated LC20 was found to act as a repressor of the motor activities of smooth muscle myosin.

Actins↗

Relative and total volume of histological components in benign prostatic hyperplasia: relationships between histological components and clinical findings.

To investigate the correlation between histological differences and clinical findings in patients with benign prostatic hyperplasia (BPH), quantitative morphometrical analysis on prostate was performed on 26 specimens obtained by TURP. The relative and total volume of each histological component were obtained. In this series, the proportion of fibrous tissue element showed a weak positive correlation with prostatic volume (r = 0.499, P = 0.0087). The relative volume of the smooth muscle component showed an inverse correlation with prostatic volume (r = -0.488, P = 0.0105). Patient age and symptom score showed no relationship with the relative volume of histological components. The total volume of all histological components increased with prostatic volume. However, an increase in the fibrous tissue element appeared to be predominant in prostatic enlargement (r = 0.970, P < 0.0001). Although the total volume of all histological components increased with prostatic size, fibrous tissue appeared to play a major role in prostatic enlargement in BPH.

Aged↗

A mutant trypsin-like enzyme from Streptomyces fradiae, created by site-directed mutagenesis, improves affinity chromatography for protein trypsin inhibitors.

The Ser-170 residue of a trypsin-like enzyme from Streptomyces fradiae (SFT), which is considered to be the active-site serine, was replaced with alanine by site-directed mutagenesis to improve the affinity chromatography step for a Kazal-type trypsin inhibitor pancreatic secretory trypsin inhibitor (PSTI). The resulting mutant SFT, designated as [S170A]SFT, was expressed in Streptomyces lividans and purified to homogeneity. [S170A]SFT was catalytically inactive, but still had the ability to bind tightly to PSTI and to soybean trypsin inhibitor with dissociation constants of 3.1 x 10(-7) M and 1.9 x 10(-8) M respectively. We further demonstrated that recombinant human PSTI secreted into Saccharomyces cerevisiae culture broth could be purified to homogeneity with a one-step [S170A]SFT-affinity column. The purified PSTI contained no molecules intramolecularly cleaved by active trypsin, which are found when trypsin-affinity chromatography is used for the purification. This eliminated the need for further separation of intact PSTI from intramolecularly cleaved PSTI by high-performance liquid chromatography, thus simplifying and improving its purification process.

Chromatography, Affinity↗

Surgical repair of a coronary sinus diverticulum not associated with Wolff-Parkinson-White syndrome.

Diverticulum of the coronary sinus is rare. A 58-year-old man without Wolff-Parkinson-White syndrome underwent repair of a coronary sinus diverticulum accompanies by mitral regurgitation. The coronary sinus diverticulum had been identified 6 years earlier and had enlarged over time. At surgery, the neck of the diverticulum was closed, and the mitral valve replaced with a CarboMedics prosthetic valve (diameter, 29 mm). This the first case report of the surgical repair of a coronary sinus diverticulum not associated with Wolff-Parkinson-White syndrome.

Coronary Angiography↗