Biomedical subjects

K Ohsawa

Publications and source records attributed to K Ohsawa.

At least 73 records · Page 4Linked to original sources

PubMed1994

The evidence of carotid body in the carotid rete of the shiba goat.

The carotid body was found in/on the cavernous sinus of the carotid rete of the Japanese miniature Shiba goat by light and electron microscopies. The carotid body-like aggregated cell group consisted of two types of cells arranged in the lobule. The first type contained membrane-bound granular vesicles; these cells resembled to the type-I cells in the carotid body. The second type contained no cytoplasmic vesicles, and were located in the periphery, investing the type-I cells. These features appear to be consistent with those of the type-II cells in the carotid body. The nerve ending showed two peculiar features in the intercellular space of type-I cells. The clear vesicle-containing nerve ending showed a structural feature indicative of efferent synapsis. The small granular vesicle-containing nerve ending has been described as a baroreceptor-like ending by VERNA (1979). All of these features are typical characteristics of the carotid body.

Animals↗

PubMed1994

Urinary and biliary metabolites of daidzin and daidzein in rats.

Examination was made of the urinary and biliary excretion of metabolites of daidzin and daidzein, the major components of roots of Pueraria lobata Ohwi (Leguminosae) in rats. The urine of rats administered daidzin orally contained four major metabolites, daidzein 7,4'-di-O-sulfate (M-1), daidzein 7-O-beta-D-glucuronide (M-2), daidzein 4'-O-sulfate (M-3), daidzein (M-4), as determined from spectroscopic and chemical data. The urine of rats treated with daidzein contained M-2--M-4 in the above metabolites. Total cumulative amounts of the four metabolites excreted in the urine at 48 h following the oral administration of daidzin and daidzein were approximately 4.8% and 4.6% of the doses administered, respectively. The bile of rats administered daidzin orally contained M-1--M-4. Daidzein 7-O-beta-D-glucuronide 4'-O-sulfate (M-5), a major biliary metabolite, was identified by the high-performance liquid chromatography (HPLC), liquid chromatography-mass spectrometry (LC-MS) and nuclear magnetic resonance (NMR) spectra. At least daidzin appeared to be hydrolyzed to aglycone after absorption in the body, and as a part of metabolites, M-1--M-4 having free hydroxyl, glucuronided or sulfated hydroxyls at the C-7 position, may then be excreted in the urine and bile.

Administration, Oral↗

PubMed1994

[Determination of synephrine in oriental pharmaceutical decoctions containing evodiae fructus by ion-pair high-performance liquid chromatography].

A simple and precise method was established for the determination of synephrine in oriental pharmaceutical decoctions containing Evodiae Fructus using high-performance liquid chromatography with sodium dodecyl sulfate (SDS) as an ion-pair reagent. Synephrine was eluted within 25 min without interference from co-existing components using an ODS column and a mixture of water-acetonitrile-SDS-phosphoric acid (70:30:0.5:0.1, v/v/w/v) as a mobile phase.

Chromatography, High Pressure Liquid↗

PubMed1994

Acute adrenal insufficiency after unilateral adrenalectomy in Cushing's syndrome: precipitation by lithium-induced thyrotoxicosis during cortisol replacement.

We present a patient with Cushing's syndrome due to adrenocortical adenoma who developed acute adrenal insufficiency one month after unilateral adrenalectomy. She had received lithium carbonate for five years for manic-depressive psychosis. Drug administration was interrupted for 2 weeks postoperatively and was resumed thereafter. At the adrenal crisis, her serum free T4 and T3 levels were both high and serum TSH was subnormal. The thyrotoxicosis subsided spontaneously within 2 weeks. Serum thyroglobulin was markedly increased during the thyrotoxic state. Tests for antimicrosomal antibodies and antithyroglobulin antibodies remained negative. Examination of an open-biopsy specimen of the thyroid gland showed no evidence of thyroiditis. We considered the transient thyrotoxicosis to be due to lithium-induced thyrotoxicosis. Caution should therefore be exercised in administering lithium carbonate, especially when the patient's adrenal reserve is low, since even a mild degree of thyrotoxicosis can precipitate an acute adrenal crisis.

Acute Disease↗

PubMed1993

Ability of N-methyl-N'-nitro-N-nitrosoguanidine, 4-nitroquinoline 1-oxide, dimethylnitrosamine, and NaCl to induce unscheduled DNA synthesis, stimulate replicative DNA synthesis, and produce DNA single-strand breaks in pyloric mucosa of rat stomach.

Male F344 rats were given test chemicals orally, and samples of their pyloric mucosa were incubated in vitro. Induction of unscheduled DNA synthesis (UDS) and stimulation of replicative DNA synthesis in the pyloric mucosa were then examined by addition of [3H]thymidine and simultaneous determinations of DNA synthesis in the presence and absence of hydroxyurea, an inhibitor of replicative DNA synthesis. DNA damage was also examined by the alkaline elution method with DNA single-strand scission as a marker. The results showed four types of abilities of the chemicals to affect UDS and replicative DNA synthesis in the pyloric mucosa of rat stomach 1-2 h after their administration: (1) induction of UDS and stimulation of replicative DNA synthesis by N-methyl-N'-nitro-N-nitrosoguanidine (MNNG), a glandular stomach carcinogen, (2) induction of only UDS by 4-nitroquinoline 1-oxide (4NQO), a glandular stomach carcinogen, (3) stimulation of only replicative DNA synthesis by NaCl, a glandular stomach tumor promoter, and (4) neither induction of UDS nor stimulation of replicative DNA synthesis by dimethylnitrosamine (DMN), a liver carcinogen. DNA single-strand scission was induced by MNNG and 4NQO, being maximal 2 h after their administration, but was not induced by NaCl or DMN. Thus it correlated well with the induction of UDS. The present results indicate four types of inductive abilities of chemicals on UDS and replicative DNA synthesis in rat stomach pyloric mucosa and show that this method can detect differences in the action mechanisms and organ specificities of glandular stomach carcinogens.

4-Nitroquinoline-1-oxide↗

PubMed1993

[A simultaneous determination of daidzin and puerarin and determination of daidzein in Oriental pharmaceutical decoctions containing puerariae radix by ion-pair high-performance liquid chromatography].

A simple and precise method was established for the simultaneous determination of daidzin and puerarin and the determination of daidzein in oriental pharmaceutical decoctions containing Puerariae Radix using high-performance liquid chromatography with tetra-n-heptylammonium bromide (THA) as an ion-pair reagent. Daidzin and puerarin were eluted within 45 min without interference with co-existing components using an ODS column and a mixture of 10 mM phosphate buffer (pH 6.5)-methanol (68:32) containing 5 mM THA as a mobile phase. Daidzein was eluted within 35 min without interference with co-existing components using an ODS column and a mixture of 10 mM phosphate buffer (pH 6.5)-acetonitrile (72:28 or 68:32) containing 5 mM THA as a mobile phase.

Chromatography, High Pressure Liquid↗

PubMed1993

[A simultaneous determination of honokiol and mangolol in Oriental pharmaceutical decoctions containing magnolia bark by ion-pair high-performance liquid chromatography. II].

A simple method using ion-pair high-performance liquid chromatography was established for the rapid and precise determination of honokiol(3',5-di-2-propenyl-1,1'-biphenyl-2,4'-diol) and magnolol(5,5'-di-2-propenyl-1,1'-biphenyl-2,2'-diol) in eighteen species of oriental pharmaceutical decoctions containing Magnolia bark. An ODS column and a mixed solvent system of water involving 10 mM tetra-n-amyl-ammonium bromide (TAA) and acetonitrile (4:6) as a mobile phase were used for the separation. Honokiol and magnolol were eluted without interference of other coexisting components within 12 min.

Biphenyl Compounds↗

PubMed1993

[A simultaneous determination of honokiol and magnolol in oriental pharmaceutical decoctions containing magnolia bark by ion-pair high-performance liquid chromatography].

A simple method using ion-pair high-performance liquid chromatography was established for the rapid and precise simultaneous determination of honokiol (3', 5-di-2-propenyl-1, 1'-biphenyl-2,4'-diol) and magnolol (5,5'-di-2-propenyl-1,1'-biphenyl-2,2'-diol) in oriental pharmaceutical decoctions containing Magnolia bark. An ODS column and a mixture of water involving 10 mM tetra-n-amylammonium bromide (TAA) and acetonitrile (4:6) as a mobile phase were used for the separation. Honokiol and magnolol were eluted without interference of other co-existing components within 12 min.

Biphenyl Compounds↗

PubMed1993

[Determination of synephrine in Oriental pharmaceutical decoctions containing aurantii nobilis pericarpium by ion-pair high-performance liquid chromatography. II].

A simple method using ion-pair high-performance liquid chromatography was established for the rapid and precise determination of synephrine in thirty three species of oriental pharmaceutical decoctions containing Aurantii Nobilis Pericarpium. An ODS column and a mixed solvent system of water, acetonitrile, sodium dodecyl sulfate and phosphoric acid as a mobile phase were used for the separation. Synephrine was eluted without interference of other coexisting components within 15 min.

Chromatography, High Pressure Liquid↗

PubMed1993

Effect of excess phenylacetate diet during pregnancy on fetal brain growth in rats.

The effects of phenylacetate (PA) on fetal brain growth were examined in pregnant rats receiving a 20% casein diet with 1.0, 1.5, 2.0 or 2.5% PA. Control rats were fed the 20% casein diet ad libitum or restricted to daily consumption of 9 and 6 g. In experimental groups of rats total food intake during pregnancy decreased, however the decrease was not so large as we had expected. By plotting the fetal brain weight (Y, mg) against maternal food intake (X, g/21 days) in control groups the following hyperbolic regression equation was obtained: Y = -4243/X + 124.6 (n: 18, r = 0.80, p < 0.001). Similar plots for excess PA rats fell below this line, indicating that prenatal fetal brain growth was impaired by an excess in PA per se specifically, as well as by decreased food intake nonspecifically. Administering the excess PA diets resulted in decreases in total RNA, total protein and RNA/DNA ratio in the fetal brain, whereas total DNA was unchanged, showing the impairment of protein synthesis, not proliferation. No remarkable changes in concentration and pattern of free amino acids in maternal plasma in excess PA groups were observed. Using a relation between total food intake during pregnancy and fetal brain weight, the extent of specific and nonspecific effects of excess PA and phenylalanine on brain growth was compared.

Amino Acids↗

PubMed1993

Joint epidemiological longitudinal dental survey in Nigeria, especially in comparison with that of Japanese.

Since 1980 we carried out a longitudinal dental survey in Ile-Ife, as a joint study with the dental school of Ife University, Nigeria, being supported by A Grant under The Monbusho International Scientific Research Program for ten years. One thousand one hundred seventy-one children and adults were examined in the 1991 survey. The data were compared with the data in the previous survey and Japanese survey. Results were as follows: 1) Caries prevalence rate and the average number of DMFT were still very low, especially showing that both the caries prevalence and the average number of DMFT decreased in the rural areas because the attrition proceeded faster than the caries, 2) Nigerian deciduous and permanent dentition were larger than in the Japanese in all items measured, 3) the condylar head was transformed from the round shape to the ultra-flat shape with age, 4) there was a fewer incidence of severe periodontal diseases despite of the marked deposition of calculus, 5) with respect to Nigerian foods, there was no difference between the rainy and dry seasons in both the urban and rural communities, 6) the weaning period of the baby is decided by their mother, taking care of the health of the baby, almost all babies at one year to two years and a few at three years and 7) the menu for the breakfast, lunch and supper of the baby was made considering the nutritional aspect of the baby.

Adolescent↗

PubMed1992

[Studies on thyroid hormone autoantibody in two euthyroid cases with spuriously high value of serum free triiodothyronine].

Spuriously high value of serum free triiodothyronine (FT3: Amerlex free T3 kit, Amersham, UK.) was noted accidentally on routine laboratory examination of two clinically euthyroid patients (case 1: FT3; 18.5 pg/ml, FT4; 1.1 ng/dl, T3; 103 ng/dl, T4; 8.2 micrograms/dl, TSH; 1.74 microU/ml, case 2: FT3; 8.5 pg/ml, FT4; 1.1 ng/dl, T3; 137 ng/dl, T4; 8.9 micrograms/dl, TSH; 1.45 microU/ml), the former with poorly controlled diabetes (FBG 253 mg/dl, HbA1c 12.1%) and the latter with essential hypertension (184/108 mmHg). Although the hypertensive patient showed mild diffuse goiter, there was no evidence that the patients had autoimmune thyroid diseases because anti-thyroglobulin antibody tests measured by radioimmunoassay and MCHA, TGHA or TBII were all negative. Their serum levels of TBG were within the normal range. Further studies revealed that both patients' sera had unusual binding activity to labelled polyaminocarboxy T3 (125I-aT3) but not labelled T3 (125I-T3). Furthermore, this binding protein was precipitated by goat anti-human immunoglobulin G (IgG). The IgG purified from both patients' sera also showed strong binding activity to 125I-aT3, which was inhibited by unlabelled T3 in a dose dependent manner. In conclusion, we found anti-T3 antibody in two clinically euthyroid patients with no apparent evidence of complicating autoimmune thyroid diseases. The stronger binding activity to polyaminocarboxy T3 rather than T3 may lead to the spuriously high value of serum FT3. The mechanisms of the production of such autoantibodies in our cases should be further investigated.

Adult↗

PubMed1992

[A case of pseudohypoparathyroidism (PHP) type II associated with Bartter's syndrome--restoration of phosphaturic response to parathyroid hormone (PTH) by treatment for hypopotassemia].

We report a case of PHP Type II whose phosphaturic response to PTH was restored by treatment for complicated Bartter's syndrome. A 34-year-old woman was admitted to our hospital in July 1990 because of tetanic convulsion. The physical examination showed normal blood pressure (118/62mmHg), round face without shortness of metacarpal bones and positive Trousseau's sign. Although renal function was normal, hypocalcemia (6.5mg/dl) and hyperphosphatemia (4.8mg/dl) in association with high levels of serum PTH (942pg/ml) and 1.25 (OH)2D3 (86pg/ml) were disclosed. Ellsworth-Howard test revealed that there was no increase in the urinary secretion of phosphate despite an increase in urinary cAMP excretion. On the other hand, hypopotassemia (2.5mEq/l) and metabolic alkalosis with high plasma renin activity (22.8ng/ml/hr) and aldosterone concentration (22.7ng/dl) were coexistent. Pressor response to angiotensin II infusion was blunted. Although no glomeruli were obtained by renal biopsy specimen, vacuolar degeneration on proximal tubules were noted. These findings indicated that she had PHP Type II associated with Bartter's syndrome. By administration of potassium (24mEq/day), spironolactone (50mg/day) and only small doses of 1 alpha-hydroxyvitamin D3 (0.5mg/day), serum levels of potassium as well as calcium were normalized and tetanic attacks disappeared. In March 1991, she was re-examined by Ellsworth-Howard test in order to clarify the effects of hypopotassemia on renal tubular response to PTH. Interestingly, phosphaturic response to PTH was restored, and the degree of increase in urinary cAMP excretion was 4 times as high as that on the first admission. These results suggest that hypopotassemia changes the response of renal proximal tubular cells to PTH, particularly such as reabsorption of phosphate and cAMP response, although it is possible that hypocalcemia may contribute to the blunted phosphaturic response to PTH. The mechanism of hypocalcemia seen in this case remains to be elucidated.

Adult↗

PubMed1992

Purification of sufficiently gamma-carboxylated recombinant protein C and its derivatives. Calcium-dependent affinity shift in immunoaffinity and ion-exchange chromatography.

Protein C, which is an important anti-thrombotic factor in the blood coagulation cascade, undergoes several post-translational modifications. gamma-Carboxylation on nine glutamic acid residues at the N-terminal region of the light chain [gamma-carboxylated glutamic acid (Gla) domain] is considered to be critical for full anti-clotting activity. It is also known that when recombinant protein C is expressed in animal cells this particular modification is often lost. We were successful in preparing a monoclonal antibody (PC01) which distinguishes the sufficiently gamma-carboxylated protein from the rest by its specific affinity for the Ca(2+)-induced conformational change of the former, and thereby developed a simple process of purifying sufficiently gamma-carboxylated protein C. Culture supernatant of Chinese hamster ovary cell transformants was first applied to Q-Sepharose and recombinant protein C was partially purified. It was then loaded onto a PC01 affinity column in the presence of 5 mM calcium chloride. Sufficiently gamma-carboxylated protein C was retained while insufficient-carboxylated protein C quickly passed through. The former was eluted with 5 mM EDTA efficiently and with high purity, contained eight Gla units per molecule, and had similar anti-clotting activity. The flow-through was relatively impure protein C which contained five Gla units per molecule and showed limited anti-clotting activity. We extended the application of the Ca(2+)-induced conformational change to conventional ion-exchange chromatography. The sufficiently gamma-carboxylated protein C was found to elute earlier in the salt gradient from an anion-exchange column in the presence of 5 mM calcium chloride being fully separated from the insufficiently carboxylated protein C.(ABSTRACT TRUNCATED AT 250 WORDS)

Amino Acids↗

PubMed1992

Purification of brush border membrane vesicles from rat renal cortex by size-exclusion chromatography.

Size-exclusion chromatography with controlled pore glass (CPG) was used in the further purification of renal brush border membrane vesicles (BBMV) isolated by the Ca precipitation method. The BBMV obtained had an almost spherical shape and their average diameter was about 95 nm in isotonic solution. The specific activities of alkaline phosphate and leucine aminopeptidase in the BBMV preparation were increased 18- and 17-fold, respectively, over those in the crude homogenate. The uptake of D-glucose by the purified BBMV in the presence of a sodium gradient reached 8.53 nmol/mg protein at 20 s. These results indicate that CPG chromatography is suitable procedure by which to obtain purified renal BBMV of homogenous size and with high specific marker enzyme activity for use in the study of membrane transport.

Animals↗

PubMed1992

Plasmodium chabaudi: association of reversal of chloroquine resistance with increased accumulation of chloroquine in resistant parasites.

The effects of tricyclic antidepressants, desipramine and imipramine, and phenothiazines, chlorpromazine and trifluoperazine, on chloroquine (CQ)-resistant and CQ-sensitive lines of P. chabaudi were examined in vivo. In mice that received daily injections of these drugs the growth of CQ-resistant and CQ-sensitive parasites was unaffected or affected very slightly, if at all. A combination of CQ and each drug suppressed the growth of CQ-resistant parasites in a dose-dependent manner. In addition, in CQ-sensitive parasites each drug also increased the susceptibility to CQ. Measurements of CQ levels by high-performance liquid chromatography showed that CQ accumulated in sensitive parasites to more than twice the level in resistant parasites at 2 to 4 hr after an injection of CQ. Verapamil and desipramine substantially increased CQ levels in both CQ-resistant and CQ-sensitive parasites. These results suggest that not only Ca2+ antagonists but tricyclic antidepressants reverse CQ resistance in CQ-resistant parasites and enhance the inhibitory effect in sensitive parasites by increasing CQ levels in those parasites. The effects of Ca2+ antagonists, tricyclic antidepressants, and phenothiazines on a pyrimethamine-resistant line of P. chabaudi were also studied. None of the Ca2+ antagonists (verapamil, nicardipine, and diltiazem) affected the growth of the parasite in combination with 20 mg/kg pyrimethamine. Tricyclic antidepressants and phenothiazines suppressed pyrimethamine-resistant parasites to some extent. However, the extent of this suppression was less pronounced as compared with that of suppression of CQ resistance by the same drugs.

Animals↗

PubMed1992

[Determination of sennoside A in oriental pharmaceutical decoctions containing Rhei Rhizoma by ion-pair high-performance liquid chromatography].

A simple method using ion-pair high-performance liquid chromatography was established for the rapid and precise determination of sennoside A in oriental pharmaceutical decoctions containing Rhei Rhizoma. This method was compared with other two methods, i.e. ion-suppression and phosphate buffer methods. Sennoside A was eluted without interference in this ion-pair method, while the determination of sennoside A was interfered by co-existing components in the other two methods.

Anthraquinones↗

PubMed1992

[Determination of synephrine in oriental pharmaceutical decoctions containing Aurantii nobilis pericarpium by ion-pair high-performance liquid chromatography].

A simple method using ion-pair high-performance liquid chromatography was established for the rapid and precise determination of synephrine in oriental pharmaceutical decoctions containing Aurantii Nobilis Pericarpium. An ODS column and a mixture of water, acetonitrile, sodium dodecyl sulfate and phosphoric acid (65:35:0.5:0.1) as a mobile phase were used for the separation. Synephrine was eluted without interference by other co-existing components within 15 min.

Chromatography, High Pressure Liquid↗