Biomedical subjects

S Okada

Publications and source records attributed to S Okada.

At least 991 records · Page 55Linked to original sources

PubMed1990

Lysosulfatide (sulfogalactosylsphingosine) accumulation in tissues from patients with metachromatic leukodystrophy.

We describe here a sensitive assay method for lysosulfatide (sulfogalactosylsphingosine) in human tissues using HPLC. The method involves extraction of lipids, saponification, isolation using a C18 Sep-Pak column, derivatization with o-phthalaldehyde, and detection of the fluorescent lysosulfatide using HPLC. In control subjects, a small amount of lysosulfatide was detected in the cerebral white matter (9-35 pmol/mg of protein), spinal cord (35 pmol/mg of protein), sciatic nerve (14 pmol/mg of protein), and kidney (approximately 2 pmol/mg of protein) but not in the cerebral gray matter and liver. A marked accumulation of the lipid was noted in tissues from six patients with metachromatic leukodystrophy (MLD). The concentration of lysosulfatide was high in the cerebral white matter, spinal cord, and sciatic nerve (223-1,172 pmol/mg of protein). Even in the cerebral gray matter, kidney, and liver, where lysosulfatide was hardly detected in the control sample, a considerable amount (3-45 pmol/mg of protein) accumulated in MLD patients. The concentration and distribution pattern of lysosulfatide were similar to those of galactosylsphingosine (psychosine) accumulated in patients with Krabbe disease. Therefore, the accumulation of lysosulfatide may explain the demyelination in patients with MLD, as is the case with Krabbe disease.

Cerebroside-Sulfatase↗

PubMed1990

Antigenic characterization of small, round-structured viruses by immune electron microscopy.

Small, round-structured viruses (SRSVs) detected from nonbacterial gastroenteritis outbreaks in Tokyo and Saitama Prefecture, Japan, during the period from 1977 to 1988 were tentatively classified into nine antigenic patterns from SRSV-1 (S-1) to SRSV-9 (S-9) by cross-immune electron microscopy (IEM). S-1 and S-2 appeared pattern specific, while S-3 to S-9, distinguishable from each other in their reactivity, appeared somewhat antigenically related. Their antigenic relatedness to the Norwal, Hawaii, and Otofuke agents was also examined by IEM by using antisera to these agents. S-3 appeared most closely related to the Norwalk agent. S-4 and S-5 were related to the Norwalk agent and, presumably, were distantly related to the Hawaii and Otofuke agents. S-6 and S-7 were related to the Hawaii and Otofuke agents. S-8 and S-9 were related to the Otofuke agent and, presumably, were distantly related to the Hawaii agent. The prevalence of each antigenic pattern in 38 outbreaks was examined: S-8 was implicated in 24% of the outbreaks S-5 in 16%, S-4 in 13%, S-9 in 13%, S-6 in 11%, and others in 5%.

Antigens, Viral↗

PubMed1990

Malignant fibrous histiocytoma of the hypopharynx.

Malignant fibrous histiocytoma has been the most common soft-tissue sarcoma of late adult life. However, it is relatively uncommon in the head and neck. Furthermore, there has been no report of malignant fibrous histiocytoma of the hypopharynx in the literature. The first case of malignant fibrous histiocytoma of the hypopharynx is presented. The patient, a 70-year-old male, underwent extended laryngectomy and elective neck dissection with primary tracheoesophageal shunt operation and pharyngeal myotomy for voice restoration following total laryngectomy. For more than 2 years, there has been no evidence of the disease or metastasis. He has the satisfactory phonatory and swallowing function.

Aged↗

PubMed1990

1,25-Dihydroxyvitamin D3 [1,25-(OH)2D3] increases insulin-like growth factor I (IGF-I) receptors in clonal osteoblastic cells. Study on interaction of IGF-I and 1,25-(OH)2D3.

We previously reported a cooperative effect between insulin-like growth factor I (IGF-I) and 1,25-dihydroxy-vitamin D3 [1,25-(OH)2D3] in murine clonal osteoblastic cells, MCT3T3-E1. In the present study, the possible mechanism of interaction between these hormones was investigated. The effect of IGF-I on 1,25-(OH)2D3 receptors in MC3T3-E1 cells was examined. The affinity and hormone binding capacity of 1,25-(OH)2D3 receptors were not altered by IGF-I. Immunoblot analysis showed about 54 kilodaltons (kDa) 1,25-(OH)2D3 receptors, similar to that observed for mouse fibroblasts. The synthesis of IGF-I by the cells under a serum-free condition was determined by RIA. The assay revealed immunoreactive IGF-I secreted by MC3T3-E1 cells (1.79 +/- 0.04 x 10(-9) M, mean +/- SE, n = 5). Rat GH significantly increased the concentration of IGF-I, but 1,25-(OH)2D3 did not. IGF-I radioligand-receptor assay revealed specific binding of IGF-I to MC3T3-E1 cells. The relative potency of IGF-I-related peptides to bind with the cells was in the order of IGF-I much greater than multiplication-stimulating activity (the rat homologue of IGF-II) greater than insulin, and the receptor protein migrated as a 130-kDa band in autoradiography. Scatchard analysis showed a significant increase in IGF-I binding sites by 50% after 3-day treatment with 5 x 10(-11) M 1,25-(OH)2D3, without any change in affinity. These results indicate that the interaction of IGF-I and 1,25-(OH)2D3 in the culture of MC3T3-E1 cells may be mediated by the effect of 1,25-(OH)2D3 on IGF-I receptors.

Calcitriol↗

PubMed1990

Study on the biodistribution of deuterated biomolecules in mice aiming at new diagnostic radio-imaging agents.

Deuterated compounds (2H-compounds) labeled with 14C prepared from deuterated algae, Chlorella ellipsoidea, were examined for their time-coursed distribution in mice after intravenous administration. The 14C-2H-compounds were fractionated and isolated from algae grown in practically 100 mol% 2H2O in the presence of 14C-bicarbonate. The fractions obtained were the "basic" and "acid" fractions, composed mainly of amino acids and sugar phosphates, respectively, and glucose, galactose, and lipid fractions. All fractions were examined for their biodistribution in mice bearing Ehrlich solid tumor in comparison with the fractions isolated from ordinary Chlorella (1H-Chlorella). 2H-Compounds thus examined showed some behaviors different from 1H-compounds. The 2H- "basic" fraction distributed more slowly in heart, lung and liver than the 1H-fraction. The 2H-specific large distribution in tumor was also observed on this fraction. The 2H-dependent characteristics in the distribution of glucose and galactose differed. The 2H-glucose level was lower in blood and higher in brain, resulting in a brain/blood ratio approximately twice that of 1H-glucose, while 2H-galactose did not show such a characteristic. These findings may be useful for the application of 2H-biomolecules to functional radio-imaging agents for nuclear medicine.

Amino Acids↗

PubMed1990

Liposomes prepared from synthetic amphiphiles. II. Their interaction with Ehrlich ascites tumor cells and tissue distribution in Ehrlich solid tumor-bearing mice.

The interaction of 99mTc-labeled liposomes prepared from synthetic amphiphiles containing amino acid residues with Ehrlich ascites tumor cells in vitro and their tissue distributions in Ehrlich solid tumor-bearing mice were investigated. The amphiphiles used were N,N-didodecyl-N alpha-[6-(trimethylammonio)hexanoyl]-L-alaninamide bromide N+C5Ala2C12), N,N-didodecyl-N alpha-(6-[dimethyl(2-carboxyethyl)ammonio]hexanoyl)-L- alaninamide bromide (CAC2N+C5Ala2C12) and S-[1-carboxy-2- ([2,3-bis(hexadecyloxy)propoxy]carbonyl)ethyl]homocysteine (HcyM-G2C1 6). Most of the radioactivity of N+C5Ala2C12 and CAC2N+C5Ala2C12 liposomes was firmly bound to Ehrlich ascites tumor cells in vitro. On the other hand, the accumulation of three 99mTc-labeled liposomes in the tumor of Ehrlich solid tumor-bearing mice was low (about 1% dose per gram of tissue), and most of the liposomes were taken up highly in the liver and spleen of the tumor-bearing mice. However, the radioactivity of the liposomes in the tumor, especially that of N+C5Ala2C12 and CAC2N+C5Ala2C12 liposomes, decreased more slowly with time than in the liver in up to 24 h after injection, suggesting that these liposomes were hard to separate from the tumor cells.

Animals↗

PubMed1990

Platelet aggregation inhibitors in hot water extract of green tea.

The effect of hot water extract of green tea on the collagen-induced aggregation of washed rabbit platelets was examined. The extract lowered submaximal aggregation and prolonged the lag time in a dose-dependent manner. After fractionation of the extract, it was revealed that the tea catechins (tannins) are active principles for inhibition and that ester-type catechins are more effective than free-type catechins. One of the ester type catechins, epigallocatechin gallate (EGCG), suppressed the collagen-induced platelet aggregation completely at the concentration of 0.2 mg/ml (= 0.45 mM). Comparing IC50 values of EGCG and aspirin it was found that the potency of EGCG is comparable to that of aspirin. Thrombin- and platelet activating factor (PAF)-induced aggregation was also inhibited by EGCG. The elevation of cyclic adenosine 3',5'-monophosphate (cAMP) level was not observed in EGCG treated platelets.

Animals↗

PubMed1990

Autoantibody to growth hormone in a patient with myasthenia gravis.

An autoantibody to GH was detected in the serum from a patient with myasthenia gravis (MG) who had never been prescribed GH. Using an immunoprecipitation technique, this autoantibody was found to belong to the IgG class and had a kappa chain. The dissociation constant of the antibody was 56.8 nmol/l and the binding capacity was 37 nmol/l. Serum samples from another 130 patients, including 37 with MG, were examined, but the GH autoantibody could not be detected. To our knowledge, this is the first report demonstrating the presence of a GH autoantibody.

Adult↗

PubMed1990

Plastic injection method for preparing microvascular corrosion casts for SEM and its practical application.

This paper examines the application of the acryl plastic injection to the preparation of vascular corrosion microcasts for scanning electron microscopy (SEM). The original injection method using acryl plastic was described by Taniguchi, Ohta et al. in 1952 and 1955, under the title of "New improved method for injection of acrylic resin". Three dimensional observations were undertaken in our laboratory on the angiology at the macro- and microscopic levels of various organs from various mammals employing the original method. Based on this extensive experience, an injection method for preparing corrosion microcasts for use in SEM was devised in our laboratory. Microcasts prepared by the present method were able to demonstrate the fine vascular architecture of each organ. In general, although applications for preparing vascular microcasts of isolated and parenchymal organs are not so difficult, the method can be used to be applicable for demonstrating the fine vascular architecture related to or within hard tissues, as well as for investigating the morphological relations between changes of vascular patterns and restorative changes in the surrounding tissues affected by experimental operations. SEM microphotographs are also presented to illustrate actual practical applications.

Animals↗

PubMed1990

Microvascular architecture of the enamel organ of the upper major incisor in the rabbit.

The ultrastructure of the ameloblasts in the rabbit major incisor was investigated previously by Okada (1983) and the amelogenetic process was classified into six zones/stages. The present paper deals with changes in the microvascular architecture and ultrastructure of the blood capillaries in proportion to the amelogenetic process in the upper major incisor of the rabbit utilizing the acryl plastic injection method. Three different vascular layers were observed in the periodontal spaces of the major incisor of the rabbit. The inner vascular network consisted of a capillary network supplying the enamel organ and its meshes have vigorously changed during the amelogenesis. The capillary network was observed to be in the shape of a ladder with a continuous wall in the proliferation zone, to appear as round meshes with a fenestrated wall in the differentiation zone, as polygonal meshes with abundant fenestrations in the secretion zone, as ovoid meshes with fenestrations in the early maturation zone, and finally as coarse and avoid meshes with a continuous wall again in the late maturation and regression zones. In the intermediate layer, arterioles and venules were located close to the capillary network, and the arterioles were derived from the short and long branches of the anterior superior alveolar artery. In the outer layer, a sinusoid network was observed to be in contact with the alveolar wall and received blood from the capillary network as well as venous vessels in the alveolar bone. The ladder-shaped capillary network mentioned above was thought to represent an intermediate form towards the succeeding zone, in which the round meshes may be suitable for supplying the nutrient elements that are needed in the differentiation of the inner enamel epithelial cells. The polygonal and ovoid meshes may be favorable for the transport of various necessary metabolic materials that are involved in the enamel ground substance formation and calcium deposition within a very short period.

Acrylates↗

PubMed1990

Fine structure of the sinus hair (pillus labialis maxillaris) and its microvascular architecture in the cat.

The hairs of the upper lip are designated as the sinus hairs morphologically and as the tactile hairs functionally. The characteristics of the sinus hair include the equipment of a follicular blood sinus, composed of cavernous and ring sinuses located between the external and internal radical dermal capsules. The present paper deals with microvascular architectures examined under SEM using plastic microvascular casts. The arterioles diverging from the superior labial artery divided into two groups near the external capsule. The radical arterioles passed through an opening at the bottom of the capsule and formed the capillary network of the hair papilla, in part communicating with the network of the radical dermal capsule. The subcapsular arteriole penetrated the external capsule and passed in the cavernous sinus up to the internal capsule, where the capillary network of the radical dermal capsule was formed. Its meshes appeared polygonal of the papilla site and elongated at the epithelial site. The follicular blood sinus extended between the sebaceous gland and the papilla radix of the sinus hair. In its papillary two-thirds, the cavernous sinus was formed by connective tissue trabeculae and in the epithelial one-third the ring sinus was formed in the shape of a doughnut without trabeculae. Locational differences in the meshes of both networks of the hair papilla and the radial dermal capsule were apparent according to the extent of the nutrient supply to the internal and external root sheathes. The follicular blood sinus acted as a reducing apparatus against the external forces pressing on the sinus hair and the cavernous sinus may serve to enhance the function of the tactile apparatus.

Animals↗

PubMed1990

[A comparative study of five indices in malocclusion for evaluating treatment needs].

The purpose of this study was to investigate the utility of five indices of malocclusion (NMT, MI, HLDI, OFI and DI) for evaluating the necessity of orthodontic treatment. One dentist scored malocclusion in 40 females (Age: 18-23). Then, another orthodontist assessed the treatment needs for malocclusion on the same subjects. We compared each score with the assessment by the orthodontist and determined the screening level score of the treatment needs for malocclusion. The sensitivity and specificity were calculated for 5 indices respectively. The selection using MI (screening level score: 12) resembled mostly the assessment by the orthodontist, followed by NMT (screening level score: 8) and DI (screening level score: 8). But the time required to score using MI was longer than using DI, and the reproducibility of NMT was inferior to DI. The subjects in this study had a high frequency of crowding (22.5%), and DI was highly correlated to the arch length discrepancy (r = -0.898). From these results, it was suggested that DI was a suitable index for evaluating the treatment needs for malocclusion, particularly crowding.

Adolescent↗

PubMed1990

[Chlormadinone Acetate Reference Standard (Control 881) of National Institute of Hygienic Sciences].

Chlormadinone acetate was tested for the preparation of the "Chlormadinone Acetate Reference Standard (Control 881)". Analytical data obtained were as follows: loss on drying, 0.00%; infrared spectrum, 1740, 1715, 1658, 1604, 1587, 1256, 1244 cm-1; ultraviolet spectrum, lambda max = 284 nm; absorbance, E1cm1% (284 nm) = 539-549; optical rotation, [alpha]D20: -12.1 degrees; melting point, 214.6 degrees C; thin-layer chromatography, contaminants were not detected until 300 micrograms; high-performance liquid chromatography, one contaminant was detected. On the basis of the above results, this material was authorized as the National Institute of Hygienic Sciences Reference Standard (Control 881).

Chlormadinone Acetate↗

PubMed1990

[Thiamine Hydrochloride Reference Standard (Control 891) of National Institute of Hygienic Sciences].

The raw material of thiamine hydrochloride was examined for preparation of the "Thiamine Hydrochloride Reference Standard". Analytical results were as follows: melting point 242.7 degrees; pH 3.2 (1 g, water, 100 ml); IR spectrum the same as that of JP Reference Standard (Control: 841); one and two impurities detected by TLC and by HPLC analyses, respectively; assay by thiochrome method 100.3% and by HPLC 100.1% against the JP Reference Standard. Based on the results, the present raw material was authorized to be the Reference Standard of the National Institute of Hygienic Sciences.

Chromatography, High Pressure Liquid↗

PubMed1990

[Mestranol Reference Standard (Control 881) of National Institute of Hygienic Sciences].

The raw material of mestranol was examined for preparation of the "Mestranol Reference Standard". Analytical results for the sample were as follows: UV spectrum indicated absorption maxima at 279 and 287 nm and absorptivity at 279 nm E1%1cm 66; IR spectrum indicated specific absorption at 1612, 1578, 1505, 1253, and 1060 cm-1; optical rotation +3.9 degrees; melting point 153.1 degrees; loss on drying 0.03%; TLC and HPLC analyses indicated one impurity, respectively; the purity was assumed to be 99.3% by HPLC analysis. Based on the results, the present raw material was authorized to be the Reference Standard of the National Institute of Hygienic Sciences.

Chromatography, High Pressure Liquid↗

PubMed1990

[Betamethasone Sodium Phosphate Reference Standard (Control 881) of National Institute of Hygienic Sciences].

The raw material of betamethasone sodium phosphate was examined for preparation of the "Betamethasone Sodium Phosphate Reference Standard". Analytical results for the sample were as follows: pH 7.90; optical rotation + 100.5 degrees; IR spectrum the same as USP Reference Standard of Betamethasone Sodium Phosphate; TLC indicated no impurities, but 5 kinds of impurities were detected in small amounts by HPLC; water content 14.7%; assay 100.2% by HPLC. Based on the above results, this raw material was authorized to be the Reference Standard of the National Institute of Hygienic Sciences.

Betamethasone↗

PubMed1990

[Dexamethasone Sodium Phosphate Reference Standard (Control 891) of National Institute of Hygienic Sciences].

The raw material of dexamethasone sodium phosphate was examined for preparation of the "Dexamethasone Sodium Phosphate Reference Standard". Analytical results were as follows: UV spectrum indicates absorption maxima at 242 nm and absorptivity at 242 nm is E1%1cm 304; optical rotation +79.0%; pH 7.7; ethanol 5.2%; water 6.0%; HPLC analysis indicates small amounts of three impurities and the purity was assumed to be 99.8%; assay by HPLC indicated 100.9% against the USP Reference Standard of "Dexamethasone Phosphate". Based on the results, the present raw material was authorized to be the Reference Standard of the National Institute of Hygienic Sciences.

Chromatography, High Pressure Liquid↗

PubMed1990

[Hydrocortisone Acetate Reference Standard (Control 891) of National Institute of Hygienic Sciences].

The raw material of hydrocortisone acetate was examined for preparation of the "Hydrocortisone Acetate Reference Standard". Analytical results were as follows: E1%1cm (242 nm) 403; IR spectrum indicates specific absorption at 3424, 1745, 1721, 1630, and 1374 cm-1; optical rotation +164.4 degrees (in dioxane); melting point 219.5 degrees (decomposition); loss on drying 0.16%; TLC and HPLC analyses indicated one and three impurities, respectively; assay by HPLC was 99.7% against the previous Reference Standard. Based on the results, the present raw material was authorized to be the Reference Standard of the National Institute of Hygienic Sciences.

Chromatography, High Pressure Liquid↗