Biomedical subjects
Publications and source records attributed to Y Fukada.
If pityriasis lichenoides et varioliformis acuta (PLAVA) exists in the vagina or cervical os of the uterus, it may cause premature labor and premature rupture of the membranes.
We monitored 30 laboratory hemostatic parameters in an attempt to better comprehend alterations in coagulation and fibrinolysis in 10 patients with hematological malignancies subjected to autologous peripheral blood stem cell transplantation (APBSCT). These parameters were assessed before and just after high-dose conditioning chemotherapy, on days 1, 7, 14 and 28. Although, clinical manifestations associated with fibrino-coagulation disorders never occurred, including veno-occlusive disease, a statistically significant increase was seen in 7 of 30 parameters, compared to values seen before conditioning chemotherapy. These were subdivided into early and late phase parameters. The early phase parameters, which increased during the first day after the conditioning chemotherapy was given, then returned to baseline values, included protein C, plasma tissue factor and tissue-plasminogen activator. The late phase parameters, which increased over baseline values during days 7 to 28, included free-protein S, fibrinogen, plasmin-alpha2-plasmin inhibitor complex and soluble-thrombomodulin. The increase of early phase parameters, as produced by the liver and by endothelial cells, may reflect tissue damage by conditioning chemotherapy. Late phase parameters increased in parallel with C-reactive protein, which suggests a correlation with the degree of inflammation, such as the presence of infective disease during neutropenia. These subclinical alterations in coagulation and fibrinolysis which take on a biphasic pattern during the course of APBSCT should be kept in mind by the attending physicians during therapy.
We have developed a system of erythroid-lineage-specific expansion of purified human peripheral blood (PB) CD34 positive cells mobilized by a granulocyte-colony stimulating factor (G-CSF), as an in vitro model for the study of the process of proliferation and differentiation of erythroid progenitor cells. In this system, PB CD34 positive cells terminally differentiated into reticulocytes, which made it feasible to conduct a study on enucleation process of human erythroblasts. Erythroid differentiation/maturation was induced in the highly purified PB CD34 positive cells in the liquid suspension culture with interleukin-3 (IL-3), stem cell factor (SCF; a ligand for c-kit) and human erythropoietin (EP); 8 days of the culture generated progenitors equivalent to colony-forming units-erythroid (CFU-E) and 12 days of the culture generated a population mainly consisting of polychromatophilic normoblasts. Within additional 4 days of the suspension culture, these cells contained hemoglobin, differentiated to orthochromatic normoblasts, and became capable of enucleation in vitro, in a time-dependent manner. Removal of all serum from the culture medium, with or without cytokines, including IL-3, SCF and EP, did not affect enucleation processes of the cells on 12th day. On electron microscopy, the incipient reticulocytes contained all cellular organelles except the nucleus, and the extruding nucleus was surrounded by a plasma membrane. Colchicine and vinblastine blocked nuclear multiplication and cytochalasin D blocked cell division with formation of multinucleated cells. Only cytochalasin D completely inhibited enucleation, which was recovered by washing out the cytochalasin D in the 12th day cell cultures. Thus, human erythroblasts do not require cytokines, including EP in their enucleation process. In this process, the contraction of filamentous actin occurs, while microtubules apparently do not participate.
A 39-year-old man with cardiomyopathy due to point mutation of mitochondrial DNA(3243) was admitted to our hospital because of exertional dyspnea accompanied by hearing disturbance and diabetes mellitus. Echocardiography revealed asymmetric hypertrophy of the anterolateral and posterior walls and systolic dysfunction of the left ventricle (fractional shortening = 18%). Pulsed Doppler mitral inflow velocity wave showed a pseudonormalized pattern. Iodine-123 betamethyl-p-iodophenyl-pentadecanoic acid (123I-BMIPP) myocardial scintigraphy showed decreased accumulation in the anterolateral, posterior, and apical walls. Left ventriculography showed moderately decreased ejection fraction (43%), and left ventricular end-diastolic pressure was mildly elevated (18 mmHg). Angiography showed normal coronary arteries, but coronary flow reserve measured by administering intravenous adenosine triphosphate was impaired in the left anterior descending and left circumflex arteries compared to the right coronary artery. Intracellular accumulations of abnormal mitochondria were detected by histologic examination of the cardiac and skeletal muscles. Evaluation of cardiac function showed that the area of myocardial hypertrophy was nearly consistent with the region of decrease in 123I-BMIPP accumulation and coronary flow reserve.
A 35-year-old man with non-Hodgkin's lymphoma (NHL) (follicular small cleaved, B cell, stage IVB) received double myeloablative chemotherapy with syngeneic peripheral blood stem cell transplantation (PBSCT). Although platelet recovery was delayed until day 29 after the second transplantation, thereafter trilineage hematopoietic reconstitution was achieved. The evaluation after PBSCT did not detect any residual tumor. The patient was in good health until day 138, when his platelet count suddenly began falling; on day 150, it had fallen to 1.5 x 10(4)/microliter, and the patient was re-admitted for treatment. The bone marrow was normocellular with a normal count and megakaryocyte structure. Other examinations, including serological tests and computed tomography of the neck, chest, abdomen, and retroperitoneum, did not indicate a recurrence of NHL or reveal the cause of thrombocytopenia. The patient's platelet-associated IgG (PAIgG) level was at 70.9 ng/10(7) platelets (normal range: 9-25 ng/10(7) platelets); a diagnosis of thrombocytopenia due to an autoimmune mechanism such as idiopathic thrombocytopenic purpura (ITP) was made. Prednisolone therapy increased the platelet count and reduced the PAIgG level. Thrombocytopenia with an ITP-like mechanism rarely occurs more than 100 days after autologous or syngeneic stem cell transplantation, and should be taken into consideration as a late complication of PBSCT.
The aim of this study is to clarify the transitional change of the proliferation and differentiation of human peripheral blood CD34+ cells to megakaryocytic lineage, focusing on its clinical application. We developed a rapid system to purify human peripheral blood CD34+ cells from healthy volunteers, which produced CD34+ cells with a 90% purity. The purified CD34+ cells predominantly consisted of CD41- cells, and the rate of coexpression of CD41 was 0.6% +/- 0.5%. When the purified cells were cultured in liquid phase for 10 days in the presence of recombinant human stem cell factor (rSCF: a ligand for c-kit), interleukin-3 (rIL-3), and thrombopoietin (rTPO: a ligand for Mpl), the number of CD34+/CD41+ cells increased to 19% +/- 7% of total expanded cells on day 4 (4 days of liquid culture) and then gradually decreased to 2.2% +/- 0.6% on day 10. The absolute number of CD34+/CD41+ cells increased and reached a plateau on day 6, and 1.7 +/- 0.6 x 10(5) CD34+/CD41+ cells were produced by 1 x 10(5) CD34+/CD41- day 0 cells. The CD34-/CD41+ cells appeared on day 6, continuously increased in number until day 10, and constituted the main population of expanded cells on day 10, with a value of 38% +/- 18%. On day 10, 19.5 +/- 10.6 x 10(5) of CD34-/CD41+ cells were produced by 1 x 10(5) CD34+/CD41- day 0 cells. The deletion of rTPO from this cytokine combination decreased the number of CD34+/CD41+ and CD34-/CD41+ cells, after days 6 and 8, respectively. Day 0 cells required rIL-3 for promoting colonies containing megakaryocytes, whereas rTPO alone promoted almost no megakaryocytic colonies from day 0 cells. Thus, a combination of IL-3 and SCF expands CD34+/CD41+ cells from CD34+/CD41- cells, and TPO mainly acts to increase CD34-/CD41+ cells. This study suggests that if the expansion of CD34+/CD41+ is performed in vitro, the 6 days' culture of peripheral blood CD34+/CD41- cells with a combination of IL-3 and SCF with TPO provides the most rapid and stable products of CD34+/CD41+ cells for the rapid recovery of platelets in patients with peripheral blood stem cell transplantation.
To identify how many rhodopsin intermediates interact with retinal G-protein transducin, the photobleaching process of chicken rhodopsin has been investigated in the presence or absence of transducin by means of time-resolved low-temperature spectroscopy. Singular value decomposition (SVD) analysis of the spectral data showed that a new intermediate called meta Ib is present between formally identified metarhodopsin I (now referred to as meta Ia) and metarhodopsin II (meta II). Since the absorption maximum of meta Ib (460 nm) is similar to that of meta Ia (480 nm), but considerably different from that of meta II (380 nm), meta Ib should have a protonated retinylidene Schiff base as its chromophore. Whereas transducin showed no effect on the conversion process between lumirhodopsin (lumi) and meta Ia, it affected the process between meta Ia and meta Ib and that between meta Ib and meta II. These results suggest that at least two intermediates (meta Ib and meta II) interact with transducin. The addition of GTPgammaS had no effect on the meta Ib-transducin interaction, while it abolished the ability of transducin to interact with meta II. Thus, meta Ib only binds to transducin, while meta II catalyzes a GDP-GTP exchange in transducin. These results suggest that deprotonation of the Schiff base chromophore is not necessary for the binding to transducin, while changes in protein structure including Schiff base deprotonation are needed to induce the GDP-GTP exchange in transducin.
Pinopsin is a blue-sensitive photoreceptive molecule possibly involved in photic entrainment of the circadian pacemaker in the chicken pineal gland. To characterize pinopsin as a circadian photoreceptor, antibodies were raised against the C-terminal portion of pinopsin. As expected from the divergence of the amino acid sequence of this region, the resultant antibody cross-reacted with neither chicken rhodopsin nor red-sensitive cone pigment (chicken red). In Western blot analysis, the antibody stained a single band of 42-kDa protein in a detergent-extract of chicken pineal membranes, suggesting that pinopsin (calculated molecular weight, 38187) might be glycosylated and/or palmitoylated. Immunocytochemical examination of pineal sections of the chicken and the pigeon with this antibody revealed strong positive images for most of the membrane structures in the lumen of the follicles. This antibody also stained string- and bulb-shaped structures of the chicken parafollicular cells, the morphology of which resembles those of retinal photoreceptor cells. In contrast to the predominant distribution of pinopsin, a monoclonal antibody specific for chicken red stained a smaller number of membrane structures in the lumen of chicken pineal follicles. These results strongly suggest that the chicken pineal gland contains at least two types of photoreceptive molecules, pinopsin (major) and chicken red (minor). We show that the former molecule is localized in parafollicular pinealocytes and in the outer segments of pinealocytes that make contact with the follicular lumen.
The avian pinealocytes have an intrinsic circadian clock function that controls rhythmic synthesis of melatonin, and an environmental light signal can reset the phase of the clock. In addition to the photoendocrine function, the melatonin synthesis of the pinealocytes is regulated by neural signals from sympathetic nerves. Thus the avian pinealocytes show diagnostic characters which seem to represent an evolutionary transition from photosensory cells of lower vertebrates to the neuroendocrinal cells of mammals. To understand the evolutionary background of the regulatory mechanism for the melatonin synthesis in this organ, we screened the chicken pineal cDNA library to find alpha-subunits of heterotrimeric G-proteins involved in the photic and neural regulations. In addition to the transducin-like alpha-subunit (Gt alpha) supposed to mediate the photic pathway, we isolated cDNA clones encoding Gi2 alpha, Gi3 alpha, and Go1 alpha and its splicing variant Go2 alpha. The deduced amino acid sequence of each G alpha had a potential site for pertussis toxin-catalyzed ADP-ribosylation. As it is known that adrenergic receptor-mediated inhibition of melatonin synthesis is blocked by pertussis toxin, the G-proteins identified in the present study are likely to contribute to this neuroendocrine function of the chicken pineal cells.
Pinopsin is a photoreceptive molecule cloned from the chicken pineal organ. An antibody highly specific for pinopsin was applied in light- and electron-microscopic immunocytochemical studies of the pineal organ of 1 to 2-month-old chickens. Intense immunoreactivity was found in the follicular lumen at the light-microscopic level. In addition, small immunoreactive spherical or fibrous structures were diffusely distributed at the parafollicular aspect of the pineal organ. To identify immunoreactive elements precisely, we used pre-embedding immunoelectron microscopy. These studies revealed immunoreactive outer segments of pinealocytes arranged closely side by side in the follicular lumina. The thin initial portion of the outer segment arose from a basal body located in the inner segment. Immunoreactive pear-shaped outer segments occupied small lumina. Follicular lumina displayed immunonegative arrays of whorl-like lamellar membranes. Occasionally, these immunonegative structures were surrounded by immunoreactive concentric lamellar complexes. In the parafollicular pineal parenchyma, long slender cilium-like structures or enlarged cilia and concentric lamellar arrays showed intense immunoreactivity. All immunoreactive structures observed in this study were considered to represent outer segments of pinealocytes of the chicken pineal organ.
OBJECTIVE: The purpose of this study was to evaluate the prognosis of fetuses with a shortened femur and humerus length detected at earlier than 20 weeks of gestation. METHODS: The study population consisted of 549 Japanese pregnant women. The prognosis of the shortened femur and humerus length fetuses was evaluated and the predictivity of the shortened femur and humerus length for chromosomal abnormalities and structural malformations was also calculated. RESULTS: All seven shortened femur and humerus length fetuses had some kind of structural malformations and three fetuses also had chromosomal abnormalities. The detection rate, positive predictive value and false positive rate for structural malformations were 17.9%, 100% and 0%, respectively. The positive predictive value for chromosomal abnormalities was 43%. CONCLUSION: The shortened femur and humerus length fetuses in Japanese women demonstrated an increased risk of structural malformations, especially in the cardiovascular system, as well as chromosomal abnormalities.
A 20-year-old Japanese man developed generalized, subcutaneous, painless nodules, fever, abnormal liver function, serosal effusions, hepatosplenomegaly, lymphadenopathy and anemia. Skin biopsies revealed lobular panniculitis with a morphologically benign histiocytic infiltration and prominent phagocytosis. Atypical T lymphocytes were also present in the skin and liver. The diagnosis given was aggressive cytophagic histiocytic panniculitis (CHP) or aggressive subcutaneous panniculitic T cell lymphoma (SPTCL). He received cyclophosphamide, doxorubicin, and vincristine on day 1, prednisolone on days 1-5, and etoposide on days 1, 3 and 5 (CHOP-E), with the support of granulocyte colony-stimulating factor. This regimen was repeated every 2 weeks and complete clinical remission (CCR) was attained after three cycles of CHOP-E. As the clinical course of aggressive CHP is recurrent and often fatal, he was given high-dose chemotherapy followed by autologous peripheral blood stem cell transplantation (APBSCT), after five cycles of CHOP-E. He has remained in CCR for 12 months after APBSCT. High-dose chemotherapy followed by APBSCT is considered to be one of the most beneficial therapies for patients with aggressive CHP and aggressive phase SPTCL.
The chicken pineal gland has an endogenous circadian oscillator that controls the diurnal oscillation of N-acetyltransferase activity responsible for melatonin rhythm. It has been speculated that the chicken pineal cell contains a photoreceptive molecule that receives the environmental light signal and transmits the signal to the oscillator for resetting the phase. In spite of several lines of evidence suggesting the similarity between retinal and pineal photon-signal transducing proteins, the identity of the photoreceptive molecule had been an open question. In 1994, we isolated a pineal cDNA encoding a novel photoreceptive molecule and named it "pinopsin." The protein expressed in 293EBNA cells bound 11-cis-retinal to form a blue-sensitive pigment with an absorption maximum at about 470 nm. A putative G-protein interaction site of pinopsin shared a relatively high similarity in amino acid sequence to that of rhodopsin, implying that pinopsin functionally couples with transducin or transducin-like G-protein(s) in the pineal cells. We have cloned a cDNA for chicken pineal transducin alpha-subunit, and the deduced amino acid sequence contained a potential site to be ADP-ribosylated by pertussis toxin (PTX). Therefore, the transducin-mediated pathway could be blocked by PTX, though previous studies showed that treatment of the cultured chicken pineal cells with PTX had no effect on the light-induced phase-shift of the oscillator. Accordingly, it is unlikely that transducin mediates the light-input pathway to the oscillator, which may involve PTX-insensitive G-protein(s) or some unidentified component(s). The G-protein coupled receptor-mediated signaling processes regulating melatonin synthesis are discussed.
OBJECTIVE: The purpose of this study was to evaluate the prognosis of fetuses with transient nuchal translucency before 15 weeks of gestation. STUDY DESIGN: A nuchal translucency's measurement of > or = 5 mm was considered abnormal. In the period from 1994 to 1995, twelve fetuses were diagnosed at our institution with nuchal translucency. The fetuses all underwent karyotyping and a complete ultrasonographic search for any associated anomalies and a resolution of nuchal translucency at 1-2 week gestational age intervals. RESULTS: Five cases ('Transient NT') demonstrated transient nuchal translucency. Seven cases ('Persistent NT') demonstrated persistent nuchal translucency. The 984 cases with no or less than 5 mm of nuchal translucency (control group) gave birth at the same time. The mean initial week of diagnosis was 12.0 +/- 1.6 weeks in 'Transient NT', and 13.6 +/- 1.8 weeks in 'Persistent NT'. The mean maternal age was 30.8 +/- 6.3 years old in 'Transient NT', 28.9 +/- 3.0 years old in 'Persistent NT', and 30.5 +/- 43 years old in the control group. Abnormal karyotypes were detected in one case in 'Transient NT', and in four cases in 'Persistent NT'. Structural malformations were detected in two cases (40%) in 'Transient NT', seven cases (100%) in 'Persistent NT', and 30 cases (3.0%) in the control group. CONCLUSIONS: Regardless of the spontaneous resolution of abnormal nuchal translucency, there was a high association with both karyotypical and structural abnormalities, and the prognosis of such cases was generally poor, especially persistent NT's prognosis.
A case of intracranial hemorrhage due to superior sagittal sinus thrombosis occurring in a boy with nephrotic syndrome is described. A twelve-year-old boy with nephrotic syndrome presented sudden onset of generalized convulsions. CT scan revealed a subcortical hematoma in the left frontal lobe. A left carotid angiography revealed the occlusion of the superior sagittal sinus. Neurological findings included disturbance of consciousness, right hemiparesis, and motor aphasia after the convulsions. All symptoms and signs disappeared immediately. There has been no evidence of rebleeding or convulsions for the last two years. This case had no abnormality of the coagulation system in routine investigation, but nephrotic syndrome and steroid therapy appeared to be associated with several disorders of the coagulation system. The authors suggested that it was necessary to pay attention to possible intracranial hemorrhage caused by cerebral venous sinus thrombosis in patients with nephrotic syndrome or who had undergone steroid therapy.
Structural changes in the complex formation between transducin and metarhodopsin II, the activated form of photolyzed rhodopsin, in visual transduction processes were analyzed by Fourier transform infrared spectroscopy. The spectrum of the complex was obtained by subtracting the contribution of metarhodopsin I and uncomplexed metarhodopsin II. The averaged spectrum upon the complex formation was then compared with that in the conversion of rhodopsin-to-metarhodopsin II. Frequency shifts of the peptide carbonyl vibrations at 1686, 1674, and 1661 cm-1 to 1640 cm-1 were observed upon complex formation from metarhodopsin II plus transducin. These changes must have resulted from the strengthening of H-bonding of one or a few peptide groups but is not ascribable to global conformation change. Changes in the frequencies of the peptide amides were also detected. With regard to intramembrane carboxylic acid residues, no further changes were noticed in the carboxyl vibrations of Asp83, Glu122, and Glu113. Only a small change possibly due to Glu134 was detected.
The clonal growth of progenitor cells from myelodysplastic syndromes (MDS) can be subdivided into four growth patterns: (1) normal, (2) no growth or low plating efficiency, (3) low colony and high cluster number, and (4) normal or high colony number with a large number of clusters. The former two (1 and 2) can be referred to as nonleukemic patterns and latter two (3 and 4) as leukemic. In a search for a role for cytokines in leukemic-type growth of MDS progenitor cells, marrow CD34+ cells were purified up to 94% for 8 normal individuals and 88% for 12 MDS patients, using monoclonal antibodies and immunomagnetic microspheres (MDS CD34+ cells). The purified CD34+ cells were cultured for 14 days with various combinations of cytokines, including recombinant human macrophage colony-stimulating factor (rM-CSF), granulocyte-CSF (rG-CSF), granulocyte-macrophage-CSF (rGM-CSF), interleukin-3 (rIL-3), and stem cell factor (SCF; a ligand for c-kit) in serum-free medium. The clonal growth of MDS CD34+ cells supported by a combination of all of the above cytokines was subdivided into the two patterns of leukemic or nonleukemic, and then the role of individual or combined cytokines in proliferation and differentiation of MDS CD34+ cells was analyzed in each group. Evidence we obtained showed that SCF plays a central role in the leukemic-type growth of MDS CD34+ cells and that G-CSF, GM-CSF; and/or IL-3 synergize with SCF to increase undifferentiated blast cell colonies and clusters over that seen in normal CD34+ cells. SCF is present in either normal or MDS plasma at a level of nanograms per milliliter, and this physiologic concentration of SCF can stimulate progenitor cells. This means that progenitor cells are continuously exposed to stimulation by SCF in vivo and that MDS leukemic cells have a growth advantage over normal blast cells. This depends, at least in part, on cytokines such as G-CSF, GM-CSF, IL-3, and SCF.
Hydrophobic modifications of transducin (T) gamma, such as farnesyl-and carboxyl-methylation, are essential for the association of T beta gamma with the photoreceptor disc membrane, and MEKA/phosducin is known to inhibit the association. In this study, we examined the effect of MEKA on the hydrophobicity of T beta gamma. MEKA could bind to T beta gamma without farnesyl/carboxyl-methyl moieties as well as native T beta gamma. In the Triton X-114 phase separation assay, T beta gamma-MEKA complex was recovered in the aqueous phase, whereas T beta gamma was recover in the detergent phase. N-terminal portion of MEKA which includes T beta gamma-binding domain was not sufficient to reduce the hydrophobicity of T beta gamma or to dissociate T beta gamma from the membrane. The data suggest that MEKA attenuates the hydrophobicity of T beta gamma to result in the dissociation of T beta gamma from the membrane without directly binding to farnesyl/carboxyl-methyl moieties.