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S Iwanaga

Publications and source records attributed to S Iwanaga.

At least 55 records · Page 3Linked to original sources
PubMed1998

Application of transmission scan-based attenuation compensation to scatter-corrected thallium-201 myocardial single-photon emission tomographic images.

A practical method for scatter and attenuation compensation was employed in thallium-201 myocardial single-photon emission tomography (SPET or ECT) with the triple-energy-window (TEW) technique and an iterative attenuation correction method by using a measured attenuation map. The map was reconstructed from technetium-99m transmission CT (TCT) data. A dual-headed SPET gamma camera system equipped with parallel-hole collimators was used for ECT/TCT data acquisition and a new type of external source named "sheet line source" was designed for TCT data acquisition. This sheet line source was composed of a narrow long fluoroplastic tube embedded in a rectangular acrylic board. After injection of 99mTc solution into the tube by an automatic injector, the board was attached in front of the collimator surface of one of the two detectors. After acquiring emission and transmission data separately or simultaneously, we eliminated scattered photons in the transmission and emission data with the TEW method, and reconstructed both images. Then, the effect of attenuation in the scatter-corrected ECT images was compensated with Chang's iterative method by using measured attenuation maps. Our method was validated by several phantom studies and clinical cardiac studies. The method offered improved homogeneity in distribution of myocardial activity and accurate measurements of myocardial tracer uptake. We conclude that the above correction method is feasible because a new type of 99mTc external source may not produce truncation in TCT images and is cost-effective and easy to prepare in clinical situations.

Adult↗
PubMed1998

Molecular interaction between factor VII and tissue factor.

Complex formation between serine protease factor VIIa (VIIa) and tissue factor (TF) dramatically enhances the catalytic activity of VIIa, leading to the initiation of extrinsic blood coagulation. The recently determined crystal structure of the complex formed between VIIa and the extracellular domain of TF has revealed in detail the interacting surfaces of the two molecules. Mutational and biochemical studies have further identified regions of VIIa and/or those of TF essential for the high affinity interaction. These studies indicate that the regions extending from the gamma-carboxyglutamic acid domain through the first epidermal growth factor-like domain and protease domain of VIIa are involved separately in the interaction with the distinct sites of TF. The interaction of TF with the protease domain of VIIa apparently induces a conformational transition of the VIIa active site. Studies of the chemical modification of VIIa provided a model for the mechanism of TF-mediated acceleration of VIIa activity. In this model, the protease domain of VIIa exists in equilibrium between minor active and dominant zymogen-like inactive conformational states, and preferential binding of TF to the active state leads to a shift in equilibrium into the active state, thereby accelerating VIIa activity. Overall docking of TF with VIIa in the presence of phospholipids further supports a recognition of macromolecular substrates, such as factors IX and X. Therefore, single VIIa-TF interaction contains several distinct mechanisms for enhancing the coagulant activity of VIIa, which may be important for the initiation of coagulation specifically mediated by TF. Studies of the interaction between VIIa and TF provide not only a detailed understanding of the regulated initiation of blood coagulation but also the potential to design novel anticoagulants for the treatment of thrombotic diseases.

Amino Acid Sequence↗
PubMed1998

Purification of a novel muscle cell growth factor S-myotrophin from porcine skeletal muscle.

A comparison of muscle weight between denerved and control rabbit hind legs revealed that a water-soluble 12 kDa substance was reduced in atrophied muscles after denervation. We hypothesised that a water-soluble growth factor exists which mediates a signal from motor nerves to muscles. To isolate this factor we modified the purification procedures of Sen et al. [S. Sen, G. Kundu, N. Mekhail, J. Castel, K. Misono, B. Healy, Myotrophin: purification of a novel peptide from spontaneously hypertensive rat heart that influences myocardial growth, J. Biol. Chem. 265 (1990) 16635-16643.], who originally purified a water-soluble growth factor from cardiac muscles. Four additional purification steps were added to the method. Using this technique, a novel muscle cell growth factor, named s-myotrophin, was purified from porcine skeletal muscle (M. longissimus thoracis). Purified s-myotrophin appeared as a single band (12 kDa) on SDS-PAGE and had a strong growth promoting activity (increase of protein synthesis) of cultured primary skeletal muscle cells. Almost no loss of growth promoting activity was observed after trypsin and chymotrypsin digestion. No fragmentation of s-myotrophin was observed after exposure to lysylendopeptidase, thermolysin, trypsin and chymotrypsin. Crude preparation of this molecule could be detected by periodic acid/Schiff (PAS) staining. Deglycosylation of s-myotrophin produced a smaller molecule having an approximately 7 kDa mass. These data indicate a novel 12 kDa protein has been isolated which has growth promoting properties on skeletal muscle cells.

Animals↗
PubMed1998

New types of clotting factors and defense molecules found in horseshoe crab hemolymph: their structures and functions.

Invertebrate animals, which lack adaptive immune systems, have developed defense systems, so-called innate immunity, that respond to common antigens on the surface of potential pathogens. One such defense system is involved in the cellular responses of horseshoe crab hemocytes to invaders. Hemocytes contain two types, large (L) and small (S), of secretory granules, and the contents of these granules are released in response to invading microbes via exocytosis. Recent biochemical and immunological studies on the granular components of L- and S-granules demonstrated that the two types of granules selectively store granule-specific proteins participating in the host defense systems. L-Granules contain all the clotting factors essential for hemolymph coagulation, protease inhibitors including serpins and cystatin, and anti-lipopolysaccharide (LPS) factor and several tachylectins with LPS binding and bacterial agglutinating activities. On the other hand, S-granules contain various new cysteine-rich basic proteins with antimicrobial or bacterial agglutinating activities, such as tachyplesins, big defensin, tachycitin, and tachystatins. The co-localization of these proteins in the granules and their release into the hemolymph suggest that they serve synergistically to construct an effective host defense system against invaders. Here, the structures and functions of these new types of defense molecules found in the Japanese horseshoe crab (Tachypleus tridentatus) are reviewed.

Animals↗
PubMed1998

Chymotrypsin inhibitor from Erythrina variegata seeds: involvement of amino acid residues within the primary binding loop in potent inhibitory activity toward chymotrypsin.

The stoichiometry of the interaction between Erythrina variegata chymotrypsin inhibitor ECI and chymotrypsin was reinvestigated by analysis of their complex with ultracentrifugation and with amino acid analysis of the components separated. The amino acid analysis clearly showed that the stoichiometry of ECI and chymotrypsin was 1:1, though the apparent molecular mass of the complex was estimated to be 60 kDa. To examine the contribution of Leu64 (the P1 residue) to the inhibitory activity of ECI, a complete set of mutated inhibitors in which the amino acid at position 64 was replaced by 19 other amino acid residues was constructed by means of site-directed mutagenesis. Potent inhibitory activities (Ki, 1.3-4.6 x 10(-8) M) exceeding that of the wild-type ECI (Ki, 9.8 x 10(-8) M) were present in the mutant proteins L64F, L64M, L64W, and L64Y. The inhibitory activity of the mutant L64R was practically identical to that of the wild-type ECI. All other mutants exhibited slightly decreased inhibitory activities with Ki values of 1.9-4.6 x 10(-7) M. These results indicate that ECI-chymotrypsin interaction involves not only the P1 site residue but also other residue(s) of ECI. A series of individual alanine mutations was then constructed in residues Gln62 (P3), Phe63 (P2), Ser65 (P1'), Thr66 (P2'), and Phe67 (P3') in order to evaluate the contribution of each residue in the primary binding loop to the inhibitory activity. Replacement of Gln62, Phe63, and Phe67 with Ala residues decreased the inhibitory activity, the Ki values being increased by approximately 3-4-fold; but replacement of Ser65 and Thr66 had relatively little effect. This suggests that the P2, P3, and P3' residues, together with the P1 residue, in the primary binding loop play an important role in the inhibitory activity toward chymotrypsin.

Amino Acid Substitution↗
PubMed1998

Perirolandic cortex in infants: signal intensity on MR images as a landmark of the sensorimotor cortex.

PURPOSE: To correlate the perirolandic low signal intensity seen on T2-weighted magnetic resonance (MR) images in neonates and infants with the anatomically located sensorimotor cortex. MATERIALS AND METHODS: Axial T2-weighted MR images of 146 consecutive patients less than 6 months old were reviewed. The sensorimotor cortex was located by identifying the central sulcus. Two independent readers attempted to identify the central sulcus using two anatomic methods independently and in combination. The location of the central sulcus was compared with that of the perirolandic low signal intensity. RESULTS: Seventy-two normal hemispheres in 36 patients and 91 abnormal hemispheres in 47 patients showed clear perirolandic low signal intensity. The central sulcus was located anatomically in 70 and 72 normal hemispheres (97% and 100%, respectively) and 90 and 91 abnormal hemispheres (99% and 100%, respectively). In all normal hemispheres, the identified central sulcus correlated with the perirolandic low signal intensity. In contrast, an apparent mismatch was found in two hemispheres in a patient with Dandy-Walker syndrome. CONCLUSION: The perirolandic low signal intensity seen on T2-weighted MR images is located exactly in the anatomic sensorimotor cortex in normal brains, whereas a mismatch can occur in abnormal brains.

Bacterial Infections↗
PubMed1998

MR imaging of the mamillothalamic tract.

PURPOSE: To demonstrate the normal and abnormal appearance of the mamillothalamic tract (MTT) on cranial magnetic resonance (MR) images. MATERIALS AND METHODS: Two formalin-fixed normal human brain specimens sectioned in axial and coronal planes were used to demonstrate the normal anatomy of the MTT. MR images were obtained in 32 volunteers. Proton-density-weighted coronal and axial pulse sequences were used. The images were evaluated for visualization quality and size and signal intensity of the MTTs in correlation with the specimens. Abnormal MTTs were identified on cranial MR images in two patients, and the imaging findings were analyzed. The clinical history of the patients was also reviewed to determine the effect of these findings on patient care. RESULTS: Normal MTTs were easily identified on MR studies of cadaveric brains and of the brains of the human volunteers. On MR images, normal MTTs were commonly symmetric in appearance, with signal intensity equal to that of other normal fiber tracts. The abnormal MTTs showed high signal intensity on images obtained with a long repetition time or asymmetric volume loss and were associated with atrophy of the ipsilateral mamillary body. CONCLUSION: Normal MTTs are readily visible on conventional MR images. Abnormality of the MTT is a very subtle finding but may be a marker of a limbic system abnormality.

Adult↗
PubMed1998

The role of alpha1-adrenoceptors in the clonidine-induced contraction and relaxation of rat aorta.

Clonidine causes dilatation of the aorta in the presence of endothelium, while it causes contraction of the aorta in the absence of endothelium. The present study was carried out to clarify the role of alpha-1-adrenoceptors in the vascular action of clonidine. The aortic rings were suspended in Krebs-Henseleit (K-H) medium, and the effects of alpha-1- and alpha-2-adrenoceptor antagonists on the clonidine-induced contractions were measured. Moreover, the role of the phosphatidylinositol (PI) response was examined. The aortic slices were incubated in K-H medium containing, [3H]myo-inositol and clonidine. The formation of [3H]inositol monophosphate (IP1) was measured with a liquid scintillation counter. Clonidine caused contraction of the aorta in the absence of endothelium, in a dose-dependent manner. This contraction was inhibited by antagonists in the following order of the potency: prazosin > phentolamine > spiperone > urapidil = yohimbine > L-659066 > atipamezole. On the other hand, clonidine inhibited norepinephrine (NE)-induced contraction in the aorta in the absence and in the presence of endothelium. Clonidine enhanced IP1 accumulation in the aorta in the absence of endothelium, whereas it inhibited NE-induced IP1 accumulation in the aorta. The present results show that alpha-1-adrenoceptors are probably involved in the clonidine-induced contraction and relaxation of the rat aorta.

Adrenergic alpha-1 Receptor Agonists↗
PubMed1998

Steroidal muscle relaxants attenuate the contractile and phosphatidylinositol responses of rat trachea.

Interaction of the steroidal muscle relaxants, pancuronium, vecuronium and rocuronium with airway muscarinic receptors of rat trachea was investigated in vitro concerning the contractile and phosphatidylinositol (PI) responses. Pancuronium and vecuronium attenuated, while rocuronium did not affect carbachol (CCh)-induced contraction and CCh-induced IP1 accumulation. Pancuronium could inhibit completely CCh-induced contraction at a dose of 30 microM, while it could not inhibit completely CCh-induced IP1 accumulation at the same dose. These drugs attenuated KCl-induced contraction. These results suggest that pancuronium and vecuronium would attenuate airway smooth muscle contraction through the inhibition of muscarinic receptor-mediated PI response, and that the inhibition of voltage-operated Ca++ channel might be involved, in part, in the attenuation by pancuronium of the contraction.

Androstanols↗
PubMed1997

A newly identified horseshoe crab lectin with binding specificity to O-antigen of bacterial lipopolysaccharides.

We identified a novel horseshoe crab hemocyte-derived lectin, which we named tachylectin-4. It has more potent hemagglutinating activity against human A-type erythrocytes than a previously identified hemocyte lectin with an affinity to N-acetylglucosamine, tachylectin-2. The purified tachylectin-4 is an oligomeric glycoprotein of 470 kDa, composed of subunits of 30 and 31.5 kDa. Ca2+ at 10 mM enhanced the hemagglutinating activity 4-fold, and the activity was inhibited by EDTA and o-phenanthroline. L-Fucose and N-acetylneuraminic acid at 100 mM completely inhibited the activity of tachylectin-4. The activity was also inhibited more strongly by bacterial S-type lipopolysaccharides (LPS) but not by R-type LPS lacking O-antigen. The most effective S-type LPS was from Escherichia coli O111:B4, and the minimum concentration required for inhibiting agglutination against human A-type erythrocytes (0.1 microg/ml) was 160-fold lower than those of S-type LPS from Salmonella minnesota. Therefore, colitose (3-deoxy-L-fucose), a unique sugar present in the O-antigen of E. coli O111:B4 with structural similarity to L-fucose, is the most probable candidate for a specific ligand of tachylectin-4. A cDNA coding for tachylectin-4 was isolated from a hemocyte cDNA library. The open reading frame of the 1344-base pair cDNA coded for the mature protein with 232 amino acids. There is no significant sequence similarity to any other known LPS-binding lectins, whereas tachylectin-4 is homologous to the NH2-terminal domain with unknown functions of Xenopus laevis pentraxin 1.

Amino Acid Sequence↗
PubMed1997

A peptidyl-prolyl cis/trans-isomerase (cyclophilin G) in regulated secretory granules.

A 27-kDa protein (p27) in horseshoe crab hemocyte that cross-reacts with antiserum against a beta-glucan-sensitive protease zymogen was purified to homogeneity, and its cDNA was cloned. The 1.7-kilobase pair cDNA contains an open reading frame of 660 base pairs, encoding a 23-amino acid signal sequence followed by a mature protein of 197 residues. The sequence of p27 exhibits strong similarity to that of cyclophilin B, a peptidyl-prolyl cis/trans-isomerase. p27 exhibits isomerase activity with a kcat/Km of 0.18 microM-1 s-1 for a peptide substrate; this activity is inhibited by cyclosporin A but is not affected by FK506. Although the p27 precursor possesses an amino-terminal secretory hydrophobic signal sequence, unlike other cyclophilin B molecules, it lacks a conserved carboxyl-terminal endoplasmic reticulum retention signal and it contains a central 8-amino acid insertion. Although p27 is secreted into the culture media of transiently expressed COS cells, it is not detected in horseshoe crab hemolymph plasma but rather is localized to the hemocyte large granules, the regulated secretory granules that are exocytosed upon stimulation. These results indicate that p27 is a new peptidyl-prolyl cis/trans-isomerase in the regulated secretory granules, and is thus designated cyclophilin G. This first report of a cyclophilin homologue in the secretory granule of the horseshoe crab hemocyte suggests that such chaperon-like proteins may constitute a key quality control system for stored proteins in exocytotic granules.

Amino Acid Sequence↗
PubMed1997

Analysis of the complex formed by Erythrina variegata chymotrypsin inhibitor with chymotrypsin and properties of the peptides prepared from the inhibitor by a limited proteolysis.

The stoichiometry of Erythrina variegata chymotrypsin inhibitor (ECI) and chymotrypsin interaction was previously estimated to be 1:2 by a titration of inhibitory activity. In the present study, gel-permeation chromatography and reverse-phase HPLC (RP-HPLC) were employed to analyze the complex formed by the inhibitor and enzyme. The results showed that ECI and chymotrypsin molecules undergo aggregation in the complex-forming buffer simultaneously with a binary complex consisting of one ECI and one chymotrypsin molecules in a soluble form. A mild lysylendopeptidase digestion of ECI produced two peptides in high yield, which were separated by RP-HPLC and characterized in terms of their structures and inhibitory activities. The N-terminal peptide, ECI-(1-107)-peptide, containing the primary reactive site retained a slight inhibitory activity, while the C-terminal peptide, ECI-(108-179)-peptide, exhibited no inhibitory activity. The inhibitory potency of the ECI-(1-107)-peptide was enhanced by the presence of the ECI-(108-179)-peptide in reconstituted mixture. Recovery of the native-like structure of the reconstituted complex was further indicated by fluorescence spectra, which showed strong conformational interaction between the two peptides; their dissociation constant Kd was calculated to be 209 nM. Taken together with the previous result obtained by chymotryptic digestion, it is suggested that the primary binding loop in ECI interacts with chymotrypsin not only by a standard mechanism but also by a non-substrate-like manner. Alternatively, ECI might have an additional binding segment in the N-terminal region which interacts with chymotrypsin by a non-substrate-like manner. Further, it is shown that the C-terminal region may support the native conformation of the binding loop(s) in the N-terminal region as an intramolecular chaperone.

Amino Acid Sequence↗
PubMed1997

Conformation of factor VIIa stabilized by a labile disulfide bond (Cys-310-Cys-329) in the protease domain is essential for interaction with tissue factor.

Unlike other trypsin-type serine proteases, zymogento-enzyme transition of conformation of factor VII apparently requires not only conversion of the zymogen to active form factor VIIa (VIIa) but also interaction of VIIa with tissue factor (TF). To determine the region of interaction that correlates with maturation of the VIIa active site, we modified intramolecular disulfide bonds in VIIa and examined the interaction of the modified VIIa with soluble TF (sTF). We found that partial reduction and S-carboxamidomethylation of disulfide bonds in VIIa led to losses of amidolytic activity and the binding ability to sTF. To determine the sites of modification that associate with the loss of functions, partially S-carboxamidomethylated VIIa was separated on a column of immobilized sTF. Each of the sTF-bound and sTF-unbound fractions and native VIIa was then digested by trypsin, and the digest was analyzed by reversed-phase high performance liquid chromatography. We found that reduction and S-carboxamidomethylation of a disulfide bond between Cys-310 and Cys-329 in the protease domain of VIIa led to loss of the binding ability with sTF, and the modification of a disulfide bond between Cys-340 and Cys-368 of VIIa led to loss of the amidolytic activity. In the three-dimensional structures of trypsinogen and trypsin, the disulfide bonds corresponding to Cys-340-Cys-368 and Cys-310-Cys-329 of VIIa are, respectively, in and adjacent to the activation domain, which has flexible conformation in trypsinogen but not in trypsin. Furthermore, the crystal structure of human VIIa.TF complex indicates that the region next to Cys-310-Cys-329 is in contact with sTF. We speculate that a regional flexibility, reflected by the labile nature of disulfide bonds of Cys-310-Cys-329 and Cys-340-Cys-368 in the protease domain, contributes to the inability of VIIa to attain the active conformation. Interaction of TF with this flexible region may stabilize the structure in a conformation similar to that of the active state of VIIa.

Amino Acid Sequence↗
PubMed1997

Synchronous and metachronous primary gastric lymphoma and adenocarcinoma: a clinicopathological study of 12 patients.

BACKGROUND: The occurrence of both malignant gastric lymphoma and adenocarcinoma in the same patient is very rare. METHODS: The resected specimens from 12 patients who had both primary gastric lymphoma and adenocarcinoma were analyzed using immunohistochemistry and in situ hybridization. RESULTS: Two different tumors were found synchronously in 10 patients (5 with independent tumors and 5 with contiguous/collision tumors) and metachronously in 2. The size of the lymphomas (mean, 7.2 cm) was larger than that of the adenocarcinomas (mean, 3.6 cm) (P < 0.005). Histologically, 9 of the 12 lymphomas (75%) were mucosa-associated lymphoid tissue lymphomas, and all lymphomas invaded the deep portion of the submucosa or deeper. Conversely, 10 of the 12 adenocarcinomas (83%) were early carcinomas. Six adenocarcinomas were intestinal type, whereas the other 6 were diffuse type. The MIB-1 index of the adenocarcinomas (mean, 50.4%) was higher than that of the lymphomas (mean, 29.3%) (P < 0.05). Helicobacter pylori (H. pylori) was documented in all 12 patients, whereas Epstein-Barr virus-encoded RNA 1 was detected in only 2. During the follow-up period after surgery, 6 patients died, 4 due to adenocarcinoma. The survival probability of all 12 patients appeared to be similar to that of previously reported patients with gastric adenocarcinoma alone, and was significantly worse than that of the 217 patients with gastric lymphoma alone (P < 0.05). CONCLUSIONS: An H. pylori infection is considered to be associated with the development of these double malignancies. In many such synchronously observed cases, lymphomas may precede carcinogenesis, while the prognosis appears to be more closely associated with the adenocarcinoma than the lymphoma.

Adenocarcinoma↗
PubMed1997

Purification and characterization of prophenoloxidase from the hemolymph of coleopteran insect, Holotrichia diomphalia larvae.

Prophenoloxidase (pro-PO), a precursor of phenol oxidase (PO), was purified from the hemolymph of coleopteran Holotrichia diomphalia larvae. The enzyme was purified to apparent homogeneity, in six steps of chromatography, using Sephadex G-100, CM-52, Dextran-sulfate Sepharose CL-6B, Phenyl Sepharose CL-4B, Sephacryl S-200, and a Mono-Q column. The preparation exhibited a single band on SDS-PAGE. The proenzyme had a molecular weight of 158 kDa, as estimated by gel filtration. On SDS-PAGE under reducing conditions, it gave a 79 kDa band, indicating that it forms a dimer of the 79 kDa protein. On the other hand, the purified pro-PO gave two well-separated peaks, named pro-PO-1 and pro-PO-2, on reverse-phase HPLC. Amino acid compositions of both proteins were indistinguishable, thereby suggesting the presence of an allelic variant or an isoprotein. On dextran-sulfate Sepharose CL-6B chromatography, a fraction containing prophenoloxidase activating enzyme(s) (PPAE fraction), free from pro-PO, was also separated. In reconstitution experiments, the activation of purified pro-PO by PPAE fraction, was observed in the presence of 5 mM Ca2+, with a specific limited proteolysis. The NH2-terminal sequence of generated PO was determined to be NH2-Phe-Gly-Glu-Asp-Asp-. The activated PO oxidized o-diphenols but did not oxidize mono-phenol and p-diphenol substrates. The purified pro-PO was not activated by trypsin, alpha-chymotrypsin, and SDS.

Amino Acid Sequence↗
PubMed1997

In Vitro Activity of the Limulus Antimicrobial Peptide Tachyplesin I on Marine Bivalve Pathogens

Tachyplesin 1 is an antimicrobial peptide extracted from hemocytes of the Japanese horseshoe crab Tachypleus tridentatus. We studied the in vitro activity of tachyplesin I against bivalve pathogens: the oyster parasites Bonamia ostreae, the intrahemocytic parasite of the flat oyster Ostrea edulis and Perkinsus marinus, the histozoic parasite of the Eastern oyster Crassostrea virginica, and the bacterium Vibrio P1, pathogenic for the clam Tapes philippinarum. Viability of the protozoans was assessed microscopically by the uptake of the vital dyes acridine orange and ethidium bromide. Following exposure to tachyplesin I, B. ostreae and P. marinus viabilities were reduced in a dose-dependent manner, up to, respectively, 94 and 62% within a 500 μg/ml peptide concentration. The fine structure of P. marinus was highly altered by the peptide. Tachyplesin I also displayed a potent activity against marine vibrios, with a MIC of 0.4-0.8 μg/ml against Vibrio P1. We examined the morphology of oyster hemocytes treated by tachyplesin I, together with the cell functional capabilities to produce chemiluminescence. No effect of the peptide was found on bivalve host cells. As transgenic technology is currently being applied to marine invertebrates, these results indicate that tachyplesin I may provide effective gene sequences to be manipulated in order to produce disease-resistant bivalves.

Journal Article↗
PubMed1997

A pregnant woman with clear cell adenocarcinoma of the ovary arising from endometriosis and with benign and borderline adenofibroma of the clear cell and endometrioid types.

We encountered a case of ovarian cancer in a 33-year-old, 8-week pregnant woman. Histological examination revealed both a transitive form of ovarian endometriosis with marked decidual changes due to pregnancy and clear cell carcinoma. Benign and borderline clear cell adenofibroma and benign and borderline endometrioid adenofibroma were also found. Parts of these adenofibromas showed transformation to clear cell carcinoma. This case suggests that clear cell carcinoma can arise from clear cell adenofibromas and/or ovarian endometriosis, even in young patients.

Adenocarcinoma, Clear Cell↗