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Biomedical subjects

R Kato

Publications and source records attributed to R Kato.

817 records · Page 46Linked to original sources

Campylobacter fetus infection of abdominal aortic aneurysm.

A 61-year-old man with Campylobacter fetus infection of an abdominal aortic aneurysm treated surgically is presented herein, the fifth survival case reported in the literature. Fever and back pain preceded the enlargement of atherosclerotic abdominal aortic aneurysm. The patient tolerated satisfactorily total excision of the aneurysm followed by axillo-femoral prosthetic bypass. Antibiotic therapy consisted of intravenous infusion of fosfomycin and gentamicin and oral administration of minocycline. The organism cultured from the aneurysmal wall and intraluminal thrombi was identified as Campylobacter fetus from its typical characteristics. It is concluded that this organism should be considered in all cases of infected aneurysm in elderly or debilitated patients.

Aneurysm, Infected↗

Metabolites of feprazone in man.

Two male volunteers received 400 mg of nonlabeled feprazone, 1,2-diphenyl-3,5-dioxo-4-(3'-methyl-but-2'-enyl)pyrazolidine. Metabolites were extracted and isolated by chromatography on silica gel. Isolated metabolites were unchanged drug, E-1,2-diphenyl-3,5-dioxo-4-(3'-hydroxymethyl-but-2'-enyl)pyrazolidine, and feprazone (C4)-beta-glucuronide. Feprazone (C4)-beta-glucuronide was the main metabolite and it belongs to a novel type of conjugate, (C)-beta-glucuronide.

Feprazone↗

Structural elucidation of a mutagenic metabolite of 3-amino-1-methyl-5H-pyrido[4,3-b]indole.

Metabolic activation of a tryptophan pyrolysate, 3-amino-1-methyl-5H-pyrido[4,3-b]indole (Trp-P-2) by liver microsomes was studied. Trp-P-2 was converted to at least four metabolites (M-1 to M-4), which were separable by HPLC or TLC. Among them, the major metabolite (M-3) was extremely mutagenic to Salmonella typhimurium TA 98 in the absence of activating enzymes and the activity accounted for almost all mutagenic effects of Trp-P-2. Metabolite M-3 was identified as 3-hydroxyamino-1-methyl-5H-pyrido[4,3-b]indole by mass spectrometry and by conversion to the 4-chloro derivative of Trp-P-2 by treatment with hydrochloric acid. The latter compound was identified by NMR and mass spectrometry.

Animals↗

Immunosuppressive acidic protein (IAP) level in serum and peritoneal washings, and its implication in determining multidisciplinary treatments.

In this study we examined the efficacy of the measurement of IAP (serum ancl peritoneal washings) during the treatment of colorectal cancers, and determined the possible benefits of using the IAP measurements from both serum and peritoneal washings. One hundred and six patients (peritoneal washings: 58, peritoneal fluid: 67) were investigated. Serum IAP levels were significantly higher in patients who underwent complicated surgical procedures which involved greater time and blood loss compared to those patients who underwent less involved surgical procedures with little loss of blood and time. In peritoneal washings, up to 66. 7% of cases with peritoneal dissemination showed elevated levels of IAP in the peritoneal cavity, while 37% of cases with no dissemination at surgery macroscopically had positive IAP levels (8 mg/g protein). The results suggest the value of IAP in determining the need for combined immunochemotherapy for patients in an immunosuppressive environment.

Adult↗

Evaluation of the capabilities of a hemoglobin vesicle as an artificial oxygen carrier in a rat exchange transfusion model.

Encapsulation of hemoglobin within a liposome is one of the strategies in the development of artificial oxygen carriers. It maintains the oxygen transporting properties of hemoglobin and, at the same time, eliminates the side effects of cell free hemoglobin. Hemoglobin vesicles (HbV) are a type of liposome encapsulated hemoglobin. They have a particle size of approximately 250 nm, a hemoglobin concentration of 10 g/dl, and the oxygen affinity, P50, is regulated to 32 Torr. In this study the authors examined the oxygen transporting capability of HbV in vivo, by performing exchange transfusions in rats. Exchange transfusion (90% of the estimated circulatory volume) with HbV suspended in 5% albumin (containing 160 mEq/L, sodium and 107 mEq/L, chloride) was carried out in male Wistar rats. Mean arterial pressure and heart rate were monitored through the arterial catheter. Arterial blood samples for gas analyses were also obtained from the arterial catheter. Abdominal aortic blood flow was measured by an ultrasonic pulsed Doppler flowmeter as an indicator of cardiac output. The oxygen tension of blood withdrawn from the right atrium was measured as an indicator of mixed venous oxygen tension. These values were employed to calculate oxygen delivery and consumption. Renal cortical and skeletal muscle tissue oxygen tensions were monitored as indicators of tissue perfusion. Five percent albumin and washed rat red blood cells suspended in 5% albumin containing 10 g/dl of hemoglobin; were employed as controls. At the completion of a 90% exchange transfusion, renal cortical and skeletal muscle tissue oxygen tensions, along with oxygen delivery and consumption, were sustained almost equally well with the HbV suspension compared to the washed rat red blood cell suspension, but declined significantly with the albumin suspension. The results indicate that the oxygen transporting capability of HbV was almost equivalent to that of rat red blood cells.

Animals↗

Absence of mutations in the analysis of coding sequences of the entire transforming growth factor-beta type II receptor gene in sporadic human breast cancers.

The transforming growth factor-beta (TGFbeta) binds the type II TGFbeta growth factor receptor (TGFbetaRII) to inhibit the growth of most epithelial tissues. Most human colon and gastric cancers with microsatellite instability (MI) have frameshift mutations in polynucleotide repeats within the TGFbetaRII coding region; these mutations truncate the receptor protein and disable the serine/threonine kinase to produce TGF-beta resistance. To further investigate the type, frequency and tissue distribution of TGFbetaRII gene mutations, in this study, we examined 36 sporadic breast cancers. We previously produced eight intron based primer pairs for mutational analysis of the entire coding region of the TGFbetaRII gene. Using these primers, we developed protocols for polymerase chain reaction-single strand conformational polymorphism (PCR-SSCP) analysis of PCR products from genomic DNA samples of 36 breast cancer patients and we tested them for microsatellite instability (MI) at eight microsatellite loci. One case demonstrated MI (2.8%) and we found no mutations. These and other recent data indicate that TGFbetaRII mutations are essentially confined to colon and gastric cancers with MI. The narrow spectrum of tissues containing RII mutations illustrates the complexity of genetic checkpoints in human carcinogenesis.

Base Sequence↗

Effects of levodopa on nocturnal penile tumescence: a preliminary study.

We studied the effects of levodopa (L-dopa), which is reported to increase the dopamine level in the brain, on male erectile function. Of the 21 subjects studied, 12 subjects who were 50 years old or older showed significant increases of two nocturnal penile tumescence (NPT) parameters, NPT frequency and total tumescence time, with L-dopa. On the other hand, in nine subjects who were younger than 50 years, maximum penile circumference increase showed a significant increment with L-dopa. This significant increment of NPT with L-dopa was not observed in the subjects who had low androgen levels. The results of this preliminary study show a positive relationship between administration of L-dopa and erectile function. L-Dopa administration may improve erectile function in subjects aged 50 years and older who have normal androgen levels.

Adult↗