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Biomedical subjects

S Fujii

Publications and source records attributed to S Fujii.

At least 685 records · Page 38Linked to original sources

1-Acyl-sn-glycerol-3-phosphate acyltransferase in maturing safflower seeds and its contribution to the non-random fatty acid distribution of triacylglycerol.

A 20,000 X g particulate preparation isolated from maturing safflower seeds catalyzed the acylation of 1-acyl-sn-glycerol 3-phosphate with acyl-CoA to form phosphatidate. The specific activity of the reaction exceeded 200 nmol min-1 mg protein-1. Although this preparation was also capable of catalyzing the acylation of sn-glycerol 3-phosphate with acyl-CoA, the hydrolysis of phosphatidate, and the acylation of 1,2-diacylglycerol, phosphatidate was the only major product when the preparation was incubated with 1-acyl-glycerol-3-P and acyl-CoA. The enzyme responsible for this phosphatidate synthesis, 1-acyl-glycerol-3-P acyltransferase, showed a strict acyl-CoA specificity. The relative order of specificity for acyl-CoA was linoleoyl = oleoyl greater than palmitoleoyl greater than elaidoyl greater than cis-vaccenoyl greater than stearoyl = palmitoyl. This observation strongly suggests that the fatty acid composition of position 2 in phosphatidate synthesized in vivo primarily depends on both the acyl-CoA specificity of the 1-acyl-glycerol-3-P acyltransferase and the fatty acid composition of the acyl-CoA pool in the cell. Thus, the absence of saturated fatty acids at position 2 of safflower triacylglycerol may be explained in terms of the acyl-CoA specificity of the 1-acyl-glycerol-3-P acyltransferase. The fatty acid moiety esterified at position 1 of glycerol-3-P also affected the effectiveness of the reaction. The 1-acyl-glycerol-3-P acyltransferase utilized 1-acyl-glycerol-3-P molecular species in the following order of effectiveness: linoleoyl = oleoyl greater than palmitoyl. With a rise in incubation temperature, the initial rates of acylation with unsaturated acyl-CoA species increased more rapidly than those for saturated acyl-CoA species. A similar tendency was observed for saturated and unsaturated acyl acceptors. These data suggest that affinity of the acyltransferase for substrates may vary in response to changes in temperature, and that 1-acyl-glycerol-3-P acyltransferase may be involved in the alteration of the individual fatty acid compositions at positions 1 and 2 of glycerolipids in tissues grown at different temperatures. Based on these findings, further metabolism of 1-acyl-glycerol-3-P acyltransferase products could be the major factor determining the non-random distribution of fatty acids in safflower triacylglycerol.

1-Acylglycerol-3-Phosphate O-Acyltransferase↗

Purification and characterization of fatty acid-binding protein from rat kidney.

We detected the presence of a fatty acid-binding protein (FABP) in rat kidney cytosols. This protein was eluted and purified 9.3-fold by sequential gel filtration and anion-exchange chromatography. Homogeneity was shown by a single band on polyacrylamide gel with a molecular weight of about 15,500. It had an optimum binding pH of 7.4. The binding of palmitate to the protein was saturable. Examination of fatty acid binding revealed the presence of a single class of fatty acid-binding sites. The apparent dissociation constant was 1.0 microM and the maximal binding capacity was 48 nmol/mg of protein. This protein showed similar binding characteristics for palmitate, oleate, and arachidonate. Rabbit antibody to this cytosolic FABP gave a single precipitin line with the antigen and selectively inhibited [14C]palmitate binding to the protein.

Amino Acids↗

Mammillothalamic enkephalinergic pathway in the rat: an immunocytochemical analysis.

We studied the afferent sources of Leu-enkephalin (ENK) -like immunoreactive (ENKI) fibers in the anteroventral thalamic nucleus (AV) of the rat using experimental immunohistochemistry. These fibers were markedly fewer on the operated side after the destruction of the medial mammillary nucleus pars medialis where a number of ENKI cells were observed. This strongly suggests that these ENKI cells project ipsilaterally to the AV. ENKI fibers seemed to reach the AV via the mammillothalamic tract.

Animals↗

Development of ciliated cells in the human fetal oviduct: an ultrastructural study.

Prenatal development of ciliated cells in the human fallopian tube was studied by light and electron microscopy in specimens obtained from 12 fetuses, aged 12-40 weeks. On light microscopy, transverse sections of the ampullary portion of the tube revealed a slit-like lumen at 12 weeks. The lumen began to fold by 15 weeks, and formed the typical villous structures by 31 weeks. On electron microscopy, the epithelial cells contained a large number of sub- and supranuclear glycogen particles until 18 weeks and an occasional solitary cilium. At 20-22 weeks, instead of glycogen particles, cytoplasmic organelles such as mitochondria, rough endoplasmic reticula and Golgi apparatus were well developed, and some cells possessed cilia with a 9 + 2 microtubular structure. Between 22 and 31 weeks, ciliated cells were sporadically observed. At 31 weeks, the epithelial cells accumulated a large number of sub- and supranuclear glycogen particles. Afterwards, numerous ciliated cells with well-developed cytoplasmic organelles were observed by 40 weeks.

Animals↗

Purification of high affinity fatty acid receptors in rat myocardial sarcolemmal membranes.

High affinity receptors for fatty acid were purified from rat cardiac sarcolemmal membrane using gel filtration, DEAE-cellulose chromatography and affinity chromatography. The purified protein was homogeneous on polyacrylamide gel electrophoresis with the molecular weight of 60 kDa. Binding studies revealed the presence of a single class of high affinity binding sites with an apparent dissociation constant of 1.0 microM and a maximal binding capacity of 12.1 pmol/micrograms protein.

Animals↗

Characterization of serum cholinesterase in familial hyper-cholinesterasemia associated with an isozyme variant band.

An investigation of the properties and kinetics of serum cholinesterase (chE) was conducted in familial cases of serum hyper-chE activity. An inhibition study with specific pseudo-chE inhibitor (ethopropazine), or with anti-human pseudo-chE sera, has produced evidence that this genetically variant chE is pseudo-chE. The Km or relative activity of the variant chE against enzyme protein turns out to be the same as that of the normal serum chE. However, the variant serum chE shows more basic pK in addition to the main pK of the normal pseudo-chE on isoelectrofocusing analysis. The serum chE isozyme analysis has revealed two different extrabands in the variant: one demonstrated as a sharp line between bands 3 and 4, which we described previously, and the other as slow migrating broad band in the cathodic region close to the origin. Both prove to be pseudo-chE. Although there have been some similar descriptions about the latter type of extraband, no reports are found about the former type. It is noteworthy that the use of heparin as an anti-coagulant caused the total disappearance of the first type of extraband. It should be remembered that only heparinized plasma was used in the earlier studies. Since the detection of the former type of band seems to be specific and is simple, our findings would probably help clinicians diagnose a familial case of hyper-chE.

Cholinesterases↗

Production of 19-hydroxy-11-deoxycorticosterone and 19-oxo-11-deoxycorticosterone from 11-deoxycorticosterone by cytochrome P-450(11)beta.

Incubation of 11-deoxycorticosterone with a cytochrome P-450(11)beta-reconstituted system yielded, in addition to corticosterone and 18-hydroxy-11-deoxycorticosterone, a new steroid product. The retention time of the new product was identical with that of authentic 19-hydroxy-11-deoxycorticosterone on high performance liquid chromatography (HPLC). The turnover number of 19-hydroxy-11-deoxycorticosterone formation was 7.0 mol/min/mol P-450. When a large amount of cytochrome P-450(11)beta was used for the reaction and the products were analyzed by HPLC, the 19-hydroxy-11-deoxycorticosterone peak disappeared from the chromatogram and concomitantly new unidentified peaks appeared. These results suggest that 19-hydroxy-11-deoxycorticosterone was further metabolized to other steroids by cytochrome P-450(11)beta. Therefore, we next incubated 19-hydroxy-11-deoxycorticosterone with cytochrome P-450(11)beta and analyzed the reaction products by HPLC. The above-mentioned unidentified peaks appeared again in the chromatogram. The retention time of one of the peaks coincided with that of authentic 19-oxo-11-deoxycorticosterone. This peak substance was purified by repeated HPLC and subjected to mass spectrometry and 1H NMR analyses. Its field desorption mass spectrum (FD-MS) showed a M+ peak at m/e 344. The 1H NMR spectrum showed the signal of an aldehyde proton instead of those of hydroxymethyl protons at the C-19 position. These results suggest that cytochrome P-450(11)beta can catalyze the 19-hydroxylation of 11-deoxycorticosterone, and the 19-hydroxy-11-deoxycorticosterone produced is further oxidized at the C-19 position to 19-oxo-11-deoxycorticosterone.

Adrenal Cortex↗

Comparison of N-acetyl-beta-D-glucosaminidase and alanine aminopeptidase activities for evaluation of microangiopathy in diabetes mellitus.

The activities of urinary N-acetyl-beta-D-glucosaminidase (NAG) and alanine aminopeptidase (AAP) were measured in 207 diabetic patients and 57 healthy controls, and the relationship of these enzymes to different stages of diabetic microangiopathy was studied. Diabetics with clinical proteinuria had higher urinary NAG and AAP (17.7 +/- 1.9 and 42.8 +/- 4.9 U/g creatinine, mean +/- SE, respectively) than healthy controls (1.8 +/- 0.1 and 10.0 +/- 0.4) or diabetics without proteinuria. Among diabetics without proteinuria, NAG excretion in those with retinopathy was slightly higher than in those without (6.4 +/- 0.5 v 5.4 +/- 0.4), and AAP in those with retinopathy was significantly higher than in those without (23.0 +/- 1.5 v 17.4 +/- 0.8, P less than 0.01). Urinary albumin measured by radioimmunoassay and lysozyme in diabetics with retinopathy but without proteinuria was higher than those without retinopathy (P less than 0.001 and P less than 0.01). The increase in albumin was the greatest in diabetics with long duration of the disease (greater than or equal to 8 years); however, NAG and AAP increased more significantly in those with high hemoglobin A1c than in patients with long duration.(ABSTRACT TRUNCATED AT 250 WORDS)

Acetylglucosaminidase↗

Malignant fibrous histiocytoma of the uterus.

A primary, malignant pleomorphic giant cell tumor of the uterus was studied by light and electron microscopy. The tumor was characterized by spindle cells, plump epithelioid cells, pleomorphic giant cells, osteoclast-like giant cells, and foamy xanthomatous cells. Histochemically, tumor cells did not show either myogenic or epithelial characteristics. Immunohistochemically, tumor cells were devoid of evidence of desmin, cytokeratin, myoglobin, and lysozyme (muramidase), but vimentin was weakly positive, and alpha 1-antichymotrypsin was weakly positive in the cytoplasm of pleomorphic giant cells. Ultrastructurally, tumor cells did not show either myogenic or epithelial features, but they resembled a variant of malignant fibrous histiocytoma. The present case was classified as a storiform-pleomorphic and giant cell type of malignant fibrous histiocytoma of the soft tissues. The uterus is considered to be an additional possible site of malignant fibrous histiocytoma.

Female↗

Serum thyrotropin (TSH) responses to thyrotropin-releasing hormone (TRH) in patients with anorexia nervosa and bulimia: influence of changes in body weight and eating disorders.

Serum thyrotropin (TSH) responses to thyrotropin-releasing hormone (TRH) were studied in 47 women with anorexia nervosa (AN) (group I) and in 11 bulimic patients of normal weight (group II). In group I, TSH responses were low in nine patients, delayed in 32 and normal in six. Patients with a normal TSH response had a lesser degree of anorexia than those with a delayed TSH response. Bulimia and vomiting were more frequently observed in the low response group. The maximum increase in TSH concentrations following TRH administration in the group I patients with vomiting (4.0 +/- 0.90 microU/ml, mean +/- S.E.) was significantly lower than that in the group I patients without vomiting or in normal controls (11.2 +/- 0.82 microU/ml and 11.1 +/- 2.34 microU/ml, respectively). Twenty-five patients with abnormal TSH responses in group I were retested after weight gain. Initially, TSH responses were low in six and delayed in 19. Following weight recovery, responses continued to be abnormal in five of the six and in eight of the 19, respectively. The symptoms of eating disorders continued in all patients with abnormal TSH responses even after weight recovery, whereas patients with normal responses after weight gain recovered from all symptoms. Of 11 patients in group II, six had abnormal TSH responses to TRH; the responses were delayed in four and low in two. Patients with normal responses had a lesser degree of eating disorder, compared with abnormal responders. These observations suggest that abnormal TSH responses in patients with AN were not necessarily due to weight loss alone; rather, they may be related to the eating disorder itself.

Adolescent↗

The effects of proteolytic enzymes on in vitro ovulation in the rabbit.

The involvement of proteolytic enzymes in follicle rupture was assessed by use of the in vitro perfused rabbit ovary. Streptokinase (10 and 100 units/ml) induced ovulation in the absence of gonadotropin. Ovulation failed to occur in contralateral control ovaries. The time of ovulation in streptokinase- and human chorionic gonadotropin--treated ovaries was similar, but significantly more ova from streptokinase-treated ovaries were immature (p less than 0.001). Other ovaries were pretreated with trans-4-(aminomethyl)-cyclohexane-carboxylic acid, an inhibitor of the conversion of plasminogen to plasmin, and then perfused with human chorionic gonadotropin (50 IU). Ovulatory efficiency was significantly reduced by trans-4-(aminomethyl)-cyclohexane-carboxylic acid at 10 or 1 mmol/L (p less than 0.001), but ovum maturity was unaffected. Aprotinin (100 or 10 micrograms/ml), a potent inhibitor of plasmin, significantly inhibited human chorionic gonadotropin-induced ovulation (p less than 0.001) but did not affect oocyte maturation. Scanning electron microscopy of detergent-treated streptokinase-perfused ovaries revealed loosening and decomposition of collagen in the tunica albuginea. These results suggest proteolytic enzyme involvement in follicle rupture.

Animals↗

Comparative studies on aetiology and epidemiology of viral conjunctivitis in three countries of East Asia--Japan, Taiwan and South Korea.

A total number of 1105 cases with viral conjunctivitis, mainly epidemic kerato-conjunctivitis (EKC) consisting of 354 cases from Sapporo, Japan, of 628 from Kaohsiung, Taiwan and of 123 from Busan, Korea, encountered during the periods, 1980-81 and/or 1983, were studied aetiologically and epidemiologically. Patients were aged from 27 days to 88 years with a peak in the 20-29 year age group. Aetiological diagnoses were established in 610 cases (55%), consisting of 536 cases (49%) caused by adenoviruses and of 74 (7%) by EV 70. The most frequently detected agent was Ad 8 (57%), followed by EV 70 (12%), Ad 3 (9%) and Ad 19 (7%). The aetiological profiles of viral conjunctivitis were generally similar in three cities of East Asia. EKC (70%) was mainly caused by Ad 8, Ad 19 and Ad 37, but AHC (13%) by EV 70 and PCF (5%) by Ad 3 and Ad 11. Ad 19 and Ad 37 isolates in three cities were compared with the cleavage patterns with restriction endonucleases, BamHl, Smal, Sall and Hindlll. All of the Ad 19 isolates tested were identical to Ad 19a reported by Wadell et al, and all but three isolates of Ad 37 were identical to the Ad 37 prototype prevalent in Europe and the US. The three isolates of Ad 37, different from the prototype in cleavage pattern with Hindlll, designated as Ad 37A, were detected in Sapporo and Kaohsiung in 1980. From the cleavage patterns with four restriction endonucleases, Hindlll, BamHl, Sa1l and Sstl, the Ad 8 isolates in 1983 were divided into three subtypes, which were associated with the cities isolated.(ABSTRACT TRUNCATED AT 250 WORDS)

Adenoviridae↗

Isolation and partial characterization of an amphiphilic 56-kDa fatty acid binding protein from rat renal basolateral membrane.

We have identified a 56-kDa fatty acid binding protein in rat renal basolateral membrane and purified it by extraction in nonionic detergent (Triton X-100), followed by gel filtration, DEAE-cellulose chromatography, and affinity chromatography. The purified protein was homogeneous on polyacrylamide gel electrophoresis in the presence of Triton X-100 or SDS. It showed amphiphilic properties on gel filtration, polyacrylamide gel electrophoresis, and oleate-Sepharose 4B chromatography. Its molecular mass was estimated to be 56 kDa by SDS-polyacrylamide gel electrophoresis. The protein showed optimal binding activity at pH 7.5 and 37 degrees C. The apparent Kd for palmitic acid was 0.79 microM. It was immunologically clearly distinct from renal cytosolic fatty acid binding protein.

Amino Acids↗

Immunological cross-reactivity of human glutathione S-transferases from blood cells.

Antibody against glutathione S-transferase (GST) from human erythrocytes precipitated GST activities from platelets, neutrophils, mononuclear cells and blast cells of acute lymphocytic leukemia, indicating that those GSTs share the immunologically identical determinants. It is possible that they are under the same genetic control.

Blood Cells↗

Phosphoglycolate synthesis by human erythrocyte pyruvate kinase.

R2-type pyruvate kinase purified monogeneously from human red cells catalyzes the phosphorylation of glycolate (glycolate kinase). Maximum activation of glycolate kinase was observed at 100 microM fructose-1,6-bisphosphate (Fru-1,6-P2) and at 2 mM glucose-1,6-bisphosphate (Glc-1,6-P2). The Km for ATP was 1.1 mM in the absence of Fru-1,6-P2 and 1.5 mM in the presence of 1 mM Fru-1,6-P2. The Km for glycolate was 20 mM in the absence of Fru-1,6-P2 and 5 mM in the presence of 1.0 mM Fru-1,6-P2. The optimum pH was over 10.5. At the physiological concentrations of Fru-1,6-P2, Glc-1,6-P2 and ATP, the glycolate kinase activity is too low to maintain the reported level of phosphoglycolate (approx. 2-5 microM). It is demonstrated that phosphorylation of glycolate by R2-type pyruvate kinase which is predominant in mature red cells plays no physiological role. The questions whether an unknown pathway for phosphoglycolate synthesis exists or whether there is actually phosphoglycolate in red cells are raised.

2,3-Diphosphoglycerate↗

Fatty acid binding protein in kidney of normotensive and genetically hypertensive rats.

Fatty acid binding protein was purified from renal medulla, and its binding activity and fatty acid composition were determined in spontaneously hypertensive stroke-prone rats (SHRSP). Wistar-Kyoto rats (WKY) were used as controls. Fatty acid binding activity was higher in 5-week-old prehypertensive SHRSP than in control WKY (0.155 +/- 0.006 vs 0.030 +/- 0.001 mol palmitic acid/mol protein). However, in 40-week-old rats, the activity was decreased only in SHRSP with established hypertension (0.035 +/- 0.002 vs 0.028 +/- 0.003 mol palmitic acid/mol protein WKY). Fatty acid compositions were similar among 5-week-old and 40-week-old control WKY and 5-week-old SHRSP (palmitic acid, 24%; stearic acid, 14%; oleic acid, 30%; linoleic acid, 29%; arachidonic acid, 3%), although the total amount of bound long-chain fatty acids was decreased in 5-week-old SHRSP, explaining the high fatty acid binding activity in this preparation. Fatty acid binding protein from 40-week-old SHRSP had an elevated proportion of endogenous arachidonic acid, with other fatty acids being relatively reduced (palmitic acid, 8%; stearic acid, 2%; oleic acid, 4%; linoleic acid, 10%; arachidonic acid, 76%), indicating increased arachidonic acid transport in the cytosol. These results show that genetically hypertensive rats had an alteration in fatty acid transport mediated by fatty acid binding protein; this alteration may be involved in the pathogenesis of hypertension.

Animals↗