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Biomedical subjects

S Baba

Publications and source records attributed to S Baba.

At least 865 records · Page 48Linked to original sources
PubMed1985

Quantitative determination of methyltestosterone and methyltestosterone-d3 in serum by gas chromatography-mass spectrometry.

A method for the quantitative estimation of methyltestosterone and methyltestosterone-d3 in biological fluids has been developed using gas chromatography-mass spectrometry-selected-ion monitoring. Methyltestosterone-d6 was used as an internal standard. Methyltestosterone and methyltestosterone-d3 in serum were determined based on the peak height ratios of the molecular ions of methyltestosterone, methyltestosterone-d3 and methyltestosterone-d6. Sensitivity, specificity, precision, accuracy and reproducibility of the present method were demonstrated to be satisfactory for application to pharmacokinetic and bioavailability studies.

Biological Availability↗
PubMed1985

Determination of testosterone propionate in human plasma by gas chromatography-mass spectrometry.

A specific, sensitive and accurate quantitative analysis of testosterone propionate in human plasma was developed using gas chromatography-mass spectrometry-selected-ion monitoring. For the calculation of testosterone propionate in plasma, peak height ratios were measured by selected-ion monitoring performed on the molecular ions of the trifluoroacetyl derivative of testosterone propionate (m/z 440) and testosterone propionate-19,19,19-d3 (m/z 443). The sensitivity of the method was judged from the lower limit of the detection of the mass spectrometer which was at 20 pg. The inter-assay coefficients of variation and relative error at a concentration of 1.31 ng/ml of plasma were 5.47% and -2.3%, respectively. The method described was applied to the determination of plasma concentrations of testosterone propionate-19,19,19-d3 following an intramuscular dose of testosterone propionate-19,19,19-d3 in a healthy male volunteer.

Adult↗
PubMed1985

[The disorder of vitamin D metabolism in patients with liver cirrhosis].

Liver cirrhosis (LC) is often associated with osteomalacia and osteoporosis. Since it has been shown that serum levels of 25 hydroxy vitamin D (25-OH-D) are reduced in LC, defective hepatic hydroxylation of vitamin D has been postulated to be responsible for the low serum 25-OH-D levels and skeletal demineralization. This study was designed, therefore, to determine serum 25-OH-D and 1 alpha, 25-(OH)2-D levels in patients with LC. Further, the response of serum 1 alpha, 25-(OH)2-D to a single oral dose of 1 alpha-OH-D3 (2 micrograms) was investigated. In 5 patients with severe decompensated LC and 3 patients with compensated LC, serum 25-OH-D and 1 alpha, 25-(OH)2-D levels were respectively measured by the modified method of Belsey and by that of Eisman. Serum 25-OH-D in patients with compensated and decompensated LC was significantly higher than that in normals. Serum levels of 1 alpha, 25-(OH)2-D in patients with decompensated LC were significantly lower than those in patients with compensated LC and normals. After a single oral administration of 1 alpha-OH-D3 at a dose of 2 micrograms, the 1 alpha, 25-(OH)2-D rose in each patient within 6h, reaching the maximum levels at 12h. The percent increase over the basal value in decompensated LC was similar to that in compensated LC.(ABSTRACT TRUNCATED AT 250 WORDS)

Dihydroxycholecalciferols↗
PubMed1985

Stable-isotope methodology for the bioavailability study of phenytoin during multiple-dosing regimens.

With the highly sensitive and specific gas chromatography-mass spectrometry (GC-MS), plasma concentrations resulting from an intravenous administration of only a small amount of stable isotopically labeled phenytoin (DPH-d10) were determined to obtain information on the accurate clearance values under steady-state conditions attained with unlabeled phenytoin (DPH-d0). A time course of DPH-d10 concentrations was followed simultaneously with DPH-d0 during dosing intervals by GC-MS, with DPH-d5 as an internal standard. The present stable-isotope methodology offered advantages for the estimation of absolute bioavailability of the oral phenytoin dose in patients, while normal therapy was continued and not withdrawn.

Adult↗
PubMed1985

Ulcerative colitis complicated by idiopathic central serous chorioretinopathy with bullous retinal detachment.

A 44-year-old woman, hospitalized with severe diarrhea due to ulcerative colitis, was found to have a rare ocular complication, idiopathic central serous chorioretinopathy with bullous retinal detachment. The ocular symptom started with the flare-up of the ulcerative colitis. Steroid therapy was not effective on the ocular disorder, while her ulcerative colitis became dormant. Relationship between the two disorders is discussed.

Adult↗
PubMed1985

Exocrine pancreatic function in rats after acute trypsin inhibitor treatment.

A single oral dose of synthetic trypsin inhibitor (TI, 20 mg/100 g) was given to rats by orogastric tube 6, 12, 18, or 24 hr before the removal of the pancreas and the preparation of isolated perfused pancreas. TI treatment induced no significant changes in body weight and total amount of DNA content in the pancreas, but pancreatic wet weight, total pancreatic protein and amylase, and the concentration of total protein and amylase relative to DNA were significantly decreased at 6 or 12 hr posttreatment, with a partial return toward control values at 18-24 hr after TI treatment. In isolated perfused pancreas, basal amylase output was similar in the control and in all 4 groups of TI-pretreated rats, while basal rate of flow of pancreatic juice was significantly increased at 12-24 hr posttreatment. Caerulein (0.1 ng/ml; 64 pM) stimulated pancreatic juice flow was greatly increased in rats pretreated with TI 12-24 hr earlier. In contrast, caerulein-stimulated amylase output was significantly lower in TI-pretreated groups compared with the control. However, when amylase output was related to the total content in the pancreas, the secretory responsiveness for amylase release was significantly higher in rats at 6-18 hr posttreatment compared with the control. The present study indicates that a single oral administration of TI modulates biological response to caerulein in the isolated perfused pancreas. The enhanced responsiveness of amylase release to subsequent stimulation is seen in early periods, while that of pancreatic juice flow is observed in late periods.

Amylases↗
PubMed1985

Comparative inhibitory effects of pirenzepine and atropine on cholinergic stimulation of exocrine and endocrine rat pancreas.

The effects of pirenzepine on carbamylcholine-stimulated exocrine and endocrine pancreatic functions were compared with those of atropine in both the isolated pancreatic acini and the isolated perfused pancreas of rats. In the isolated acini pirenzepine and atropine produced a concentration-dependent inhibition of amylase secretion initiated by carbamylcholine. This inhibition resulted in a rightward shift in the dose-response curve for carbamylcholine-stimulated amylase secretion without altering the maximal increase in amylase secretion. Pirenzepine was, however, approximately 300 times less potent than atropine in inhibiting the stimulated amylase release. A similar difference in potency was observed with respect to carbamylcholine stimulation of pancreatic juice, amylase, and insulin release from the isolated perfused pancreas. The maximal inhibitory concentration of pirenzepine on a maximal effective concentration of pirenzepine on a maximal effective concentration of carbamylcholine for stimulating pancreatic exocrine secretion was 10 microM, whereas that of atropine was 30 nM. The present data define the pirenzepine receptors in the exocrine and endocrine pancreas as low-affinity-type receptors.

Amylases↗
PubMed1985

A specific method of glycosylated hemoglobin using furosine measurement.

In order to get an accurately specific determination of glycosylated hemoglobin (GHb-f), the furosine assay method, which can detect epsilon-amino-lysine-bound glucose, was investigated. A good correlation was found between GHb-f values obtained by this method and HbA1 values by conventional ion exchange column chromatography. It was, therefore, considered that this technique would be a new useful method for determining glycosylated hemoglobin.

Diabetes Mellitus↗
PubMed1985

Characterization of an insulin degrading enzyme from cultured human lymphocytes.

An insulin degrading enzyme from cultured human lymphocytes, IM-9 cells, has been purified and characterized. The biochemical, enzymatic and immunological characteristics of this enzyme were all found to be similar to the characteristics of insulin degrading enzymes previously isolated from rat and pig skeletal muscle. Furthermore, this insulin degrading enzyme was found to have no effect on the structure of the insulin receptor nor to be linked to the insulin receptor either on the plasma membrane of cells or when they are shed into the media. The present studies suggest that the IM-9 lymphocytes, which have been extensively used to study the human insulin receptor, may also be a good system for studying human insulin degrading enzymes.

Animals↗
PubMed1985

Effects of tris(hydroxymethyl)aminomethane on biosynthesis and release of insulin in the pancreatic Langerhans islets.

Tris(hydroxymethyl)aminomethane (Tris) has been shown to inhibit selectively the Golgi apparatus and Golgi-endoplasmic reticulum-lysosomal system (GERL system) of several kinds of cells including pancreatic B cells. This study was designed to assess the effect of Tris on insulin, glucagon and somatostatin release and insulin synthesis in pancreatic B cells by using isolated rat pancreatic islets. Tris suppressed glucose-induced insulin release, whereas it did not affect the glucagon and somatostatin release. Furthermore, the incorporation of [3H]leucine into the insulin fraction was suppressed by 10 mM Tris, but the sum of the radioactivity of both proinsulin and insulin fraction were not influenced. The present study suggests that the Golgi apparatus and GERL system may play a role in insulin secretion and biosynthesis in pancreatic B cells.

Animals↗
PubMed1985

Evaluation of periflux blood flow measurement in diabetic patients with autonomic neuropathy.

The periflux blood flow (PBF) response pattern in the fingertips determined with a periflux laser Doppler flowmeter was analyzed in a standing test in which the subject was instructed to stand up from the sitting position and in Valsalva's maneuver in which respiration was held for 10 s at the maximum inspiration, and indicators such as reaction time (RT), orthostatic dysreaction rate (ODR) and PBF decreasing velocity (PDV) were established for determining autonomic abnormality. RT and ODR were significantly correlated with the change in blood pressure and pulse rate, respectively, in the standing test, and PDV was significantly correlated with beat-to-beat variation. Abnormalities were found in about half of the diabetics in the standing test and Valsalva's maneuver. These results suggested that the analysis of PBF changes in the standing and Valsalva's tests may be an easy and useful approach for clinical examination of the autonomic nervous system.

Adult↗
PubMed1985

Concomitant suppression of plasma ACTH- and beta-endorphin-like immunoreactivity by cyproheptadine, naloxone, and somatostatin in the ectopic ACTH syndrome.

Release of plasma ACTH- and beta-endorphin (beta-EP)-like immunoreactivity (LI) was studied in vivo in a patient with an ectopic ACTH-producing malignant thymoma. Administration of lysin vasopressin stimulated concomitant release of plasma ACTH- and beta-EP-LI. Administration of cyproheptadine, naloxone, and somatostatin significantly suppressed plasma levels of ACTH- and beta-EP-LI, while saline infusion did not. Gel exclusion chromatography of the plasma extracts revealed that ACTH-LI consisted of two components, large and small molecular weight form, while beta-EP-LI consisted of three components, large molecular weight, beta-lipotropin-, and beta-EP-sized form; each of these components was incompletely suppressed by somatostatin infusion. It is suggested that certain tumors may have acquired aberrant multiple receptors during malignant transformation which may lead to the paradoxical hormone response as demonstrated in this case.

ACTH Syndrome, Ectopic↗
PubMed1985

Determination of carbamylated plasma protein and its clinical application to renal failure.

We determined carbamylated plasma protein (CPP) according to the method of Hunninghake in patients with renal failure and normal subjects. CPP values were significantly higher in patients with renal failure than in normal subjects. In patients with renal failure, a significant correlation was found between CPP levels and blood urea nitrogen. Thus, CPP appears to be a new indicator of the status of renal failure, irrespective of hemodialysis.

Blood Urea Nitrogen↗
PubMed1985

Interaction of caerulein, glucose, and amino acids on insulin secretion from the perfused rat pancreas.

The effect of caerulein on insulin response to graded amounts of glucose from the isolated perfused rat pancreas was investigated in the presence or absence of an amino acids mixture. Caerulein at a concentration of 0.1 ng/ml which is a submaximal concentration for an effect on exocrine pancreatic secretion potentiated insulin responses to glucose concentrations less than 200 mg/dl, but produced no further increase when added to a glucose stimulus over a 200 mg/dl. However, in the presence of amino acids the insulin response to 200 mg/dl glucose was significantly potentiated by the stimulation of 0.1 ng/ml caerulein. The effectiveness of caerulein as an insulinotropic agent depended on the glucose concentration only when amino acids were present. These results indicate that caerulein, at a concentration which stimulate pancreatic exocrine secretion, has a synergistic effect on insulin response to glucose and amino acids and therefore raises the possibility that endogenously released CCK may contribute to the entero-insular axis.

Amino Acids↗