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Biomedical subjects

M Sakoda

Publications and source records attributed to M Sakoda.

At least 19 recordsLinked to original sources
PubMed1999

[Arterial infusion therapy with implantable port for inoperable hepatobiliary tumors].

PURPOSE: To assess the clinical utility of arterial infusion therapy with implantable port for inoperable malignant hepatobiliary tumors. MATERIALS AND METHODS: Twenty-seven patients with advanced hepatobiliary tumors (M:F = 14:13, mean age 63.6, 11 cases with metastases from colon cancer, 4 cases from gastric cancer, 5 cases with gallbladder cancer, 3 cases with cholangiocarcinoma, 2 cases with cholangiocellularcarcinoma, 1 case with hepatocellular carcinoma and 1 with pancreatic cancer) were treated with arterial infusion ports which were placed via left subclavian artery or femoral artery. The regimens used were FEM for 5 cases, EEP for 2 cases and FP for 20 cases. RESULTS: Overall mean survival date was 241.8 days. The numbers of cases with CR, PR, NC and PD were 1, 6, 10 and 10, respectively, and the effective rate was 25.9%. Mean survivals of cases with cholangiocellularcarcinoma, metastases from gastric cancer and colon cancer were 715 days, 324.3 days and 245.9 days, respectively. Severe gastrointestinal side effects (> grade 3) were not observed. Serious bone marrow suppressions were frequently observed with FEM and EEP, but were rare with FP (10%). DISCUSSION: Arterial infusion therapy with implantable port is clinically useful for advanced cholangiocancer and metastases from the gastrointestinal system. This system contributes to the quality of life of patients, since the infusion procedure is simple and can be archived in the outpatient clinics.

Adult↗
PubMed1998

[Experience of 7 cases with home parenteral nutrition in our hospital].

We have experienced 7 patients with home parenteral nutrition (HPN), (including 3 failure cases). Four were benign disease and 3 were malignant. The HPN was given for 0 to 316 days. In 3 cases, we could not allow them to leave the hospital. All 3 cases involved malignant disease. The catheter was removed in only 1 case because of infection. Technical complications due to catheterization or catheter maintenance were not found in the other 6 cases. For successful management of HPN, the following 3 points are necessary for patients, family or doctors. 1) Patients and their family must understand their disease and condition. 2) Patients and their family have great hopes of spending their final days at home. 3) Doctors should have more concern for HPN.

Adult↗
PubMed1996

High serum alpha-fetoprotein concentration associated with pseudoinfarction of a cirrhotic liver: report of a case.

We report herein the case of a 65-year-old man with cirrhosis of the liver in whom a portal vein thrombus was found to be the cause of a marked elevation in serum alpha-fetoprotein (AFP). The patient presented with fever and abdominal pain, and a diagnostic work-up revealed a liver mass and an increased serum AFP concentration of 91,000 ng/ml. The mass gradually regressed, and the AFP concentration simultaneously decreased to 163 ng/ml. However, because hepatocellular carcinoma (HCC) could not be ruled out, a partial hepatectomy was performed. Histological examination of the resected specimen revealed a thrombus of the portal vein surrounded by the fibrosis associated with liver cirrhosis, but no neoplastic lesion was found. Thus, portal thrombus associated with liver cirrhosis might induce an extremely high level of AFP production.

Aged↗
PubMed1993

Autoxidation of human hemoglobin: kinetic analysis of the pH-profile.

The autoxidation reaction of human hemoglobin A was studied over the pH range of 5.3-10.4 in 0.1 M buffer at 37 degrees C. In the first-order plot, hemoglobin showed a biphasic reaction, which consisted of a rapid initial reaction and was followed by a slower second phase in the acidic or neutral pH range (5.3-8). However, this difference decreased with increase of pH of the solution and only a single-phase reaction was observed in alkali solutions above pH 8. For the kinetic analysis of the time course of the reaction, computer fitting was made to obtain curves as a function of time by a non-linear least squares method using a biphasic first-order equation with rate constants of kf and ks for the initial fast component reaction and for the slower second reaction, respectively. The parameter of the molar fraction (P) with a rate constant of kf was computed in the range of 0.45-0.55, which means that hemoglobin was autoxidized with half of the component via the reaction process with the initial rapid rate (kf) and the other half via the reaction with the following slower rate (ks). kf and ks thus obtained versus pH plot also indicated that (1) both rate constants increase markedly with increase in hydrogen ion concentrations, but (2) when pH > 8, kf becomes equal to ks with P = 1.0, and (3) there appears a rate minimum at pH 8-8.5, followed by a considerable elevation of the rate with increase in hydroxyl ion concentration. In order to examine these complicated pH-profiles, some mechanistic models were proposed for the autoxidation reaction of hemoglobin. Fitting of their rate equations as a function of pH was examined for the experimental rate constants kf and ks versus pH plot by the least squares method with use of a computer. Both pH-profiles could be best explained by the "acid-base catalyzed model." This revealed not only the catalytic role of hydrogen ions but also the involvement of hydroxyl ions and water molecules in the autoxidation reaction of human hemoglobin.

Hemoglobin A↗
PubMed1977

Effects of thyroxine and cold exposure on hypothalamic TRH levels in rats with various pituitary-thyroid states.

The hypothalamic content and concentration of thyrotropin-releasing hormone (TRH) were determined by radioimmunoassay in normal, thyroidectomized, hypophysectomized and cold-exposed rats with or without thyroxine. In normal animals, the single administration of thyroxine (1,5 and 20 microgram/100 g B.W.) altered neither the content nor the concentration of TRH in the hypothalamus. However, seven days' administration of this hormone resulted in the dose-dependent increase in the hypothalamic TRH levels. In thyroidectomized rats the hypothalamic TRH levels were slightly reduced in spite of the marked increase of plasma TSH levels and decrease of pituitary TSH levels. In the animals given thyroxine (10 microgram/100 g B.W.) for 7 days in addition to thyroidectomy, however, the TRH levels exceeded that in the animals which underwent throidectomy alone. The hypothalamic TRH levels were markedly reduced in hypophysectomized rats. Conversely, in hypophysectomized rats given 7 days' thyroxine (1 and 5 microgram/100 g B.W.), the levels were increased dose-dependently. In cold-exposed rats, the plasma TSH levels roughly doubled, but the TRH levels remained unchanged. These findings strongly suggest that the feedback site of thyroxine extends not only to the pituitary gland but also to the hypothalamus, and that thyroxine has an increasing effect of the hypothalamic TRH level, though the mechanism(s) remain to be clarified.

Acclimatization↗
PubMed1977

Physiologic role of somatostatin. Insulin release from rat islets treated by somatostatin antiserum.

In order to clarify the physiologic role of somatostatin in insulin release, rat pancreatic islets treated by somatostatin antiserum were incubated in media containing various concentrations of glucose. Insulin release from antiserum-treated islets was significantly elevated above that from nontreated ones at 3.3 and 8.3 mM glucose, while the former was not different from the latter at 16.7 mM glucose. It is suggested that somatostatin plays an important role in the regulation of insulin release in the physiologic range of glucose concentration.

Animals↗
PubMed1976

Determination of the best-fit values of kinetic parameters of the Michaelis-Menten equation by the method of least squares with the Taylor expansion.

The best-fit values of the Michaelis constant (Km) and the maximum velocity (V) in the Michaelis-Menten equation can be obtained by the method of least squares with the Taylor expansion for the sum of squares of the absolute residual, i.e., the difference between the observed velocity and the corresponding velocity by calculation. This method makes it possible to determine the values of Km and V not in a trial-and-error manner but in a deductive and unique manner after some iterative procedures starting from arbitrary approximate values of Km and V. These values can be said to be uniquely determined for a set of data as the finally converged values are no longer dependent upon the initial approximate values of Km and V. It is also very important to obtain initial approximate values of parameters for the application of the method described above. A simple method is proposed to estimate the approximate values of parameters involved in fractional functions. The method of rearrangement after canceling of denominator of a fractional function can be utilized to obtain approximate values, not only for cases of two unknown parameters such as the Michaelis-Menten equation, but also for cases with more than two unknowns.

AMP Deaminase↗
PubMed1976

A method for the deductive and unique determination of the values of three parameters involved in fractional functions applicable to relaxation kinetics.

A novel method is proposed to determine deductively and uniquely the values of three parameters, a, b, and c in a fractional function of the form, y=a+bx/(c+x) where x and y are experimentally obtainable variables. This type of equation is frequently encountered in chemistry and biochemistry involving relaxation kinetics. The method of least squares with the Taylor expansion is employed for direct curve fitting of observed data to the fractional function. Approximate values of the parameters, which are always necessary prior to commending the above procedure, can be obtained by the method of rearrangement after canceling the denominator of fractional functions. This procedure is very simple, but very effective for estimating provisional values of the parameters. Deductive and unique determination of the parameters involved in the fractional function shown above can be accomplished for the first time by the combination of these two procedures. This method is extended to include the analysis of relaxation kinetic data such as those of temperature-jump method where the determination of equilibrium concentrations of reactants in addition to the three parameters is also necessary.

Acridines↗
PubMed1975

Diurnal variation of the human urinary TRH excretion measured by radioimmunoassay.

Urine TRH was estimated by the radioimmunoassay which was accomplished according to the method of Bassiri and Utiger. Minimum detectable dose of TRH was 25 pg and recovery of TRH ranged from 72% to 112% in our laboratory. Intraassay coefficients of variation were 5.4% to 14.0% and interassay variations were 10.6% to 15.0%. Of the TRH analogues tested, only two (Ser-His-Pro-NH2, Thr-His-Pro-NH2) had potent reactivity to anti-TRH serum in large dose of 100 ng/tube. Urine samples were kept at -20 degrees C after adjusted to pH 3.0 because the inactivation of TRH in urine was markedly dependent on temperature and pH value. Using this radioimmunoassay, diurnal variation of the urinary TRH excretion at regular intervals in normal subjects was observed. Peak TRH excretion occurred around early morning, while minimum of the excretion was observed around noon. Total urinary TRH excretion of 24 hours was 817-1579 ng (M+/-SE: 1241+/-89 ng) in normal subjects. In patients with chronic renal failure, urinary excretions of TRH was obviously lower than those of normal subjects.

Adolescent↗