Some problems of dual-energy X-ray absorptiometry in the clinical use.
Explore the source record for details and available documents.
Absorptiometry, Photon↗
Biomedical subjects
M Fukunaga
Publications and source records attributed to M Fukunaga.
Ultrastructural characteristics of intercellular contacts and bile canaliculi in neonatal rat hepatocytes in primary culture.
The ultrastructure of the cellular contacts and bile canaliculi was examined in cultured neonatal (day 5) rat hepatocytes to elucidate the development of cellular polarity. A new scanning electron microscopic technique for cultured hepatocytes allowed a view of cell-cell attachment and the entire cell surface, including the underside on plastic dishes. At 3 h after plating, neonatal hepatocytes were shown to be round, with loss of the preferential localization of cell organelles. After 6 h of culture, the cells had become oblong; they were aggregated in groups of several cells and the cellular contacts were not as rigid or as straight as those in adult hepatocytes. Transmission electron microscopy showed the biliary functional polarity to be like that in vivo. On the undersurfaces of adjacent neonatal hepatocytes a hemicanalicular structure lined with microvilli was found, which probably corresponds to the ultrastructure of bile canaliculi in vivo. However, no canaliculi or orifices of bile channels were found in adult hepatocytes. These results suggest that in neonatal rat hepatocytes the formation of tight rigid cellular contacts was suppressed. Modulation of cell membranes appeared on the undersurfaces of neonatal hepatocytes in early culture stages. The differences in the development of cellular polarity could be caused by the proliferating activity of neonatal hepatocytes.
Animals↗
Effects of human epidermal growth factor on the development of bile canaliculi in neonatal rat hepatocytes in primary culture.
We have examined the effects of human epidermal growth factor (hEGF), a growth-promoting factor for hepatocytes, on the cytoskeletal structure and intercellular contacts in neonatal hepatocytes in primary culture. The ultrastructural characteristics of cellular contacts and bile canaliculi (BC) were examined using a newly developed technique of scanning electron microscopy for cultured hepatocytes. The neonatal hepatocytes incubated with hEGF plus insulin for 3 h showed more variety in shape than controls, and their cellular contacts were very loose with many long fibers. At this time, there were no changes in the distribution of microtubules or microfilaments. After treatment with hEGF plus insulin for 21 h, the distribution of microfilaments was altered. Actin filaments no longer surrounded BC, but were observed near the cell periphery; in addition, DNA synthesis was increased to 3.9 times the rate in controls. Treatment with dexamethasone for 3 h caused tight straight cellular contacts, and after 21 h actin filaments appeared around slightly dilated BC, but there was no increase in DNA synthesis. Transmission electron microscopy showed that the transport and secretion of horseradish peroxidase in BC was inhibited after 3-h incubation with hEGF. These results suggested that hEGF first affected the cellular contacts of hepatocytes necessary for the development of cellular polarity, and then affected the distribution of actin filaments, the development of functioning BC being suppressed.
Actin Cytoskeleton↗
Studies on the glomerular microcirculatory actions of manidipine and its modulation of the systemic and renal effects of endothelin.
We examined the actions of intravenously administered manidipine on systemic and renal microcirculatory hemodynamics and its efficacy in antagonizing endothelin-1 (ET-1)-evoked responses. Manidipine was a potent vasodilator with preferential activity in the renal vasculature. Its administration in optimal doses resulted in decreases in systemic arterial pressures accompanied by increases in renal perfusion and filtration rates. Its primary sites of action in the kidney were at both pre- and postglomerular arteriolar sites. Manidipine was capable of near-total reversal of the sustained elevations in arterial pressure and the progressive reductions in renal blood flow and glomerular filtration rates induced by intravenously administered ET-1. In the presence of prolonged calcium channel blockade, subsequent administration of ET-1 led to paradoxic hypotensive responses, which could be profound and blocked by an inhibitor of nitric oxide synthesis. These unexpected vasorelaxant actions of ET-1 in the presence of manidipine were likely caused by the dual effects of antagonism of its own intrinsic vasoconstrictor action (through calcium channel blockade), as well as ET-1-evoked release of the endothelium-derived relaxing factor, nitric oxide.
Animals↗
Malignant trophoblastic tumors: immunohistochemical and flow cytometric comparison of choriocarcinoma and placental site trophoblastic tumors.
We performed an immunohistochemical and flow cytometric study of the formalin-fixed, paraffin-embedded tissues of eight recent gestational choriocarcinomas (CCs) and three placental-site trophoblastic tumors (PSTTs). The follow-up period ranged from 1 to 144 months (mean, 74.3 months). In the CCs, which consisted predominantly of cytotrophoblasts and syncytiotrophoblasts intermingled with small amounts of intermediate trophoblasts, cytotrophoblasts were occasionally positive for beta-subunit human chorionic gonadotropin (HCG) and syncytiotrophoblasts contained abundant HCG. Some intermediate trophoblasts were positive for HCG and many were positive for human placental lactogen. In the three PSTTs, which were characterized by a monomorphic proliferation of intermediate trophoblasts, the tumor cells were positive for human placental lactogen and placental alkaline phosphatase. The tumors of two patients, including one fatal case, contained more human placental lactogen-positive cells than HCG-positive cells, while the tumor of the remaining patient, who had high serum HCG levels, showed a reversed staining pattern resembling that of CC; this patient has been alive without disease for 9 years. One CC patient and one PSTT patient died of multiple lung metastases, despite hysterectomy and multiagent chemotherapy. All CCs and PSTTs had an exclusively diploid DNA content, and there was no correlation among histopathologic and immunohistochemical features, DNA ploidy, S-phase fraction, and clinical outcome for patients with these tumors. These results suggest that there is a PSTT that immunohistochemically resembles CC and that flow cytometric and immunohistochemical analysis may not be effective tools to predict the biologic behavior of malignant trophoblastic tumors.
Adult↗
Metastasizing placental site trophoblastic tumor. An immunohistochemical and flow cytometric study of two cases.
An immunohistochemical and flow cytometric DNA study of two cases of metastasizing placental site trophoblastic tumor are presented. One patient aged 29 died rapidly of widespread metastases despite hysterectomy and multiagent chemotherapy. The patient had a low level of serum HCG. The course was complicated by the presence of a nephrotic syndrome. The other patient aged 34 had a vaginal metastasis and high levels of serum HCG, and was alive without disease for 9 years after hysterectomy and chemotherapy. Histologically, these tumors were characterized by a monomorphic trophoblastic cell population, probably derived from intermediate trophoblast in the placental site. The mitotic rate in these tumors was 2-4/10 high-power fields. Immunohistochemically, many tumor cells contained human placental lactogen and placental alkaline phosphatase. Beta-unit chorionic gonadotropin was present in many cells of the second patient, and only focally in the first. All specimens including the curettaged and metastatic lesions revealed a diploid DNA content in both cases. Neither DNA ploidy nor S-phase fraction was associated with survival of patient. Since predicting the biologic behavior of placental site trophoblastic tumor is very difficult, making a correct diagnosis on endometrial curettings, hysterectomy, and monitoring serum HCG level is essential in patients with this tumor.
Adult↗
Analysis of Borrelia species associated with Lyme disease by rRNA gene restriction fragment length polymorphism.
We investigated the usefulness of rRNA gene restriction fragment length polymorphism (RFLP) for grouping of the Borrelia isolates associated with Lyme disease or from ixodid ticks. Genomic DNA was digested with a restriction enzyme, blotted and hybridized with an rrl (23S rRNA) gene probe. The sizes of the restriction bands showed a good correlation with the genotypes recently proposed, and Borrelia isolates of diverse geographic origin formed four distinct DNA groups. Group I included all of the USA isolates and some European isolates; group II contained European isolates and Asian isolates; group III comprised European and Asian isolates; group IV included Japanese isolates and an eastern Russian isolate. Groups I, II and III corresponded to Borrelia burgdorferi, B. garinii and group VS461, respectively. The RFLPs of Japanese isolates were rather divergent and some of the isolates were quite distinct from the USA and European isolates. RFLP analysis of the rRNA genes and flanking regions, using rrl gene probes as we reported here, may be useful in the taxonomic study of Borrelia.
Blotting, Southern↗
Characterization of Borrelia species isolated from ixodid ticks, Ixodes ovatus.
Thirty-two Borrelia isolates were obtained from the adult stage of ixodid ticks, Ixodes ovatus, collected in various localities in Japan. Borrelial isolates were cultivated and analyzed by polyacrylamide gel electrophoresis, with monoclonal antibodies, by pulsed field gel electrophoresis, and by genomic Southern hybridization. All borrelial isolates showed similar protein profiles and monoclonal antibody reactivities, while plasmid profiles were rather diverse. Genomic hybridization using rRNA gene probes demonstrated the genetic similarities of those isolates. We found no significant differences among the borrelial isolates tested, and the restriction fragment length polymorphism patterns of I. ovatus isolates were quite distinct from those of borrelial strains associated with Lyme disease. Therefore, the isolates of Borrelia obtained from I. ovatus were thought to fall into different genospecies.
Animals↗
Organization of ribosomal RNA genes in Borrelia burgdorferi sensu lato isolated from Ixodes ovatus in Japan.
Borrelia burgdorferi sensu lato was obtained from adult ixodid ticks, Ixodes ovatus, collected in Nagano, Japan, and was named NT112. The genomic DNA was digested with enzymes, electrophoresed, blotted and hybridized with rRNA gene probes obtained from B. burgdorferi sensu stricto B31. The results showed that the borrelial chromosome contains a single rrs (16S rRNA gene) sequence and two copies of rrl/rrf (23S/5S rRNA genes) sequences. The rrl/rrf genes were tandemly repeated at intervals of 3.2 kb and were located separately from the rrs gene on the genome. Our findings indicate that the organization of rRNA genes in Borrelia from I. ovatus ticks is identical to that of B. burgdorferi sensu stricto.
Animals↗
Immunohistochemistry of molar and non-molar placentas with special reference to their differential diagnosis.
An immunohistochemical study analyzing distributions of beta-subunit human chorionic gonadotropin (beta HCG), human placental lactogen (HPL), placental alkaline phosphatase (PLAP), and monoclonal anti-cytokeratin (PKK1) was undertaken to determine whether the reactivity of these antigens might assist in the differential diagnosis of molar and non-molar hydropic placentas. A total of 16 complete hydatidiform moles, 15 partial hydatidiform moles, 12 hydropic abortuses and 39 non-hydropic placentas with gestational age ranging from 4 to 40 weeks was examined. In both the complete and partial moles, many syncytiotrophoblasts stained for beta HCG, HPL, PLAP and PKK1 although the staining intensity of beta HCG in the partial moles was weak compared with the complete moles. The staining patterns in the hydropic abortuses were almost the same as those in the normal first trimester placentas and had no distinct features from the partial moles. Trophoblastic hyperplasia is an essential feature in differentiating partial moles from hydropic abortuses. With regard to the immunostaining patterns of these antibodies, there was no significant difference to enable delineation between partial and complete moles, or between a hydropic abortus and a partial mole. Monoclonal anti-cytokeratin was most sensitive for trophoblasts, but less specific for intermediate trophoblasts than HPL. Although an immunohistochemical study using antibodies against beta HCG, HPL, PLAP and PKK1 is very useful for characterizing various trophoblasts, it is considered that an immunohistochemical study may not be a suitable tool for the differential diagnosis of molar and non-molar hydropic placentas.
Adolescent↗
Antigenic and genetic characterization of Borrelia species isolated from Ixodes persulcatus in Hokkaido, Japan.
Ten characteristic strains of spirochetes (HT2, HT7, HT10, HT15, HT17, HT19, HT20, HT22, HT32, and HT59) isolated from Ixodes persulcatus adult ticks in Hokkaido, Japan, were selected and analyzed by polyacrylamide gel electrophoresis, with monoclonal and polyclonal antibodies, and by pulsed-field gel electrophoresis. The protein profiles of the borrelial isolates were variable and markedly different from that of the type strain Borrelia burgdorferi B31. The 41-kDa flagellin protein was present in all isolates, but the outer surface protein A (OspA) was absent in four isolates (HT15, HT2, HT20, and HT32). The molecular weights of the OspA proteins in six isolates were found to differ from one isolate to another. No two isolates examined had the same plasmid profile. These findings show the antigenic and genetic heterogeneity of the Japanese isolates, and some isolates are strikingly different from North American, European, and Asian strains.
Animals↗
Evaluation of genetic divergence of borrelial isolates from Lyme disease patients in Hokkaido, Japan, by rRNA gene probes.
Eight spirochetal isolates (JEM1 to JEM8) were obtained from cutaneous lesions of patients with Lyme disease in Hokkaido, Japan, and were analyzed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis, reactivities with monoclonal and polyclonal antibodies, and Southern blot hybridization. The protein profiles of these borrelial isolates were variable and differed markedly from that of Borrelia burgdorferi B31. The 41-kDa flagellin protein was present in all isolates, but the outer surface protein A that reacted with monoclonal antibody H5332 was absent from four clinical isolates (JEM1, JEM5, JEM7, and JEM8). Genomic hybridization with rRNA gene probes demonstrated the genetic divergences among those isolates. These findings indicate that the borrelial isolates from patients in Japan are quite characteristically unique.
Adult↗
Evidence for the existence of F2-isoprostane receptors on rat vascular smooth muscle cells.
The isoprostanes are nonenzymatically generated prostanoids synthesized in vivo in humans and rats through reactions catalyzed by free oxygen radicals. 8-Epi-prostaglandin F2 alpha (8-epi-PGF2 alpha), an F2-isoprostane, is a potent smooth muscle constrictor. A thromboxane A2 (TxA2) receptor antagonist, SQ 29548, blocks renal vasoconstriction during 8-epi-PGF2 alpha administration in rats. With the use of cultured rat aortic smooth muscle cells, we found specific binding sites for [3H]SQ 29548 and for [125I]BOP, a TxA2 agonist. Both ligands were displaced from these binding sites by 8-epi-PGF2 alpha, although with significantly lesser potency than nonlabeled SQ 29548, I-BOP, or U-46619, a TxA2 agonist. In contrast, 8-epi-PGF2 alpha stimulated inositol 1,4,5-trisphosphate production and DNA synthesis in these cells with significantly greater potency than any TxA2 agonist, effects only partially inhibited by SQ 29548. In human TxA2 receptor cDNA-transfected cells, competition by 8-epi-PGF2 alpha for specific [3H]SQ 29548 binding was negligible. Thus 8-epi-PGF2 alpha probably exerts its biological actions in vascular smooth muscle through activation of receptor sites related to but distinct from TxA2 receptors. The existence of such binding sites suggests novel avenues for investigation into the biology of TxA2 and of free radical-mediated tissue injury.
Animals↗
Leukotriene D4 is a mediator of proteinuria and glomerular hemodynamic abnormalities in passive Heymann nephritis.
We assessed the role of leukotrienes (LTs) in Munich-Wistar rats with passive Heymann nephritis (PHN), an animal model of human membranous nephropathy. 10 d after injection of anti-Fx1A antibody, urinary protein excretion rate (Upr) in PHN was significantly higher than that of control. Micropuncture studies demonstrated reduced single nephron plasma flow and glomerular filtration rates, increased transcapillary hydraulic pressure difference, pre- and postglomerular resistances, and decreased ultrafiltration coefficient in PHN rats. Glomerular LTB4 generation from PHN rats was increased. Administration of the 5-LO activating protein inhibitor MK886 for 10 d markedly blunted proteinuria and normalized glomerular hemodynamic abnormalities in PHN rats. An LTD4 receptor antagonist SK&F 104353 led to an immediate reduction in Upr and to reversal of glomerular hemodynamic impairment. Ia(+) cells/glomerulus were increased in PHN rats. In x-irradiated PHN rats, which developed glomerular macrophage depletion, augmented glomerular LT synthesis was abolished. Thus, in the autologous phase of PHN, LTD4 mediates glomerular hemodynamic abnormalities and a hemodynamic component of the accompanying proteinuria. The synthesis of LTD4 likely occurs directly from macrophages or from macrophage-derived LTA4, through LTC4 synthase in glomerular cells.
Animals↗
Spontaneous abortions and DNA ploidy. An application of flow cytometric DNA analysis in detection of non-diploidy in early abortions.
The value of DNA ploidy analysis utilizing paraffin-embedded materials in the detection of nondiploid gestations was examined in a year series of 217 spontaneous abortions in first trimester at a hospital. These placentas were histologically classified as follows: 19 hydropic placentas, six partial moles, three complete moles, and 189 nonhydropic placentas. Abnormal DNA content was found in 26 cases (12%). Twelve placentas (5.6%) were triploid, seven were tetraploid, and seven were nontriploid/tetraploid aneuploid. Of the triploid placentas, six were partial moles, one was a hydropic placenta, and the remaining five were nonhydropic. Since large mononuclear cells in villous mesenchyme were observed in the triploid and tetraploid as well as in the diploid hydropic placentas, in which category trisomic gestation was probable, these cells were not considered to be characteristic of trisomic placentas. Although placentas with hydropic villi had a significantly higher frequency of the nondiploid DNA content than nonhydropic placentas, with the exception of partial moles, no correlation between the histology of villi and DNA ploidy was observed. Flow cytometric analysis using paraffin-embedded materials appears to be of value for the retrospective study of spontaneous abortions, especially for assessing aneuploidy.
Abortion, Spontaneous↗
[Four cases of advanced adenocarcinoma showing marked response to EAP (etoposide, ADM, CDDP) treatment].
Four cases of unresectable adenocarcinoma due to multiple metastasis were treated by EAP (etoposide, ADM, CDDP). The first was a 49-year-old male with gall bladder cancer, who was admitted to the hospital with metastatic umbilical tumor and intraabdominal dissemination. After 2 courses of treatment, the tumor was significantly decreased and the dissemination was diminished. The second was a 42-year-old female of breast cancer, involving lung, adrenal gland and bone metastasis. After 2 courses of treatment, all metastasis responded remarkably. Case 3 was a 42-year-old female with recurrent rectal cancer. Her lung metastasis completely disappeared after EAP treatment. Case 4 was a 42-year-old breast cancer patient with multiple liver metastasis, who also exhibited a remarkable response. In spite of severe side effects, EAP treatment was remarkably effective in all four cases of unresectable advanced adenocarcinoma.
Adenocarcinoma↗
Application of flow cytometry in diagnosis of hydatidiform moles.
We analyzed the nuclear DNA content of 219 hydropic placentas and 68 control (nonhydropic) placentas by flow cytometry (FCM) using formalin-fixed paraffin-embedded tissues. Of 129 cases originally diagnosed as complete hydatidiform mole (CM), 91 were diploid, 25 tetraploid, one triploid, and 12 aneuploid. Of five invasive CM, two were diploid, and three (including one metastasizing mole) were tetraploid. Of 49 partial hydatidiform moles (PM), 36 were triploid and 13 were diploid. Of 41 hydropic abortuses (HA), 34 were diploid, one tetraploid, four triploid, and two aneuploid. Three control placentas were triploid, and the remaining 65 placentas were diploid. Based on FCM and review of the histology, 10 PM were reclassified as HA, and one PM was revised as CM. Four HA were reclassified as PM. One CM was revised as PM. These results show that the difficulty of histologic diagnosis of gestational trophoblastic diseases may lie in PM. Clinical follow-up information was available in 51 CM and 20 PM, and persistent trophoblastic disease followed 18% of CM and 0% of PM. Among diploid complete moles, DNA ploidy did not associate with persistent disease. A significant increase S-phase fraction (SPF) was detected in diploid CM when compared with HA and control placentas. However, among diploid CM, there was no significant difference of SPF between those with and without persistent disease. These findings suggest that DNA measurements by FCM may be an important aid in the diagnosis of hydropic placentas, but not a useful tool for predicting persistent disease.
Adolescent↗
A flow cytometric DNA analysis of giant cell tumors of bone including two cases with malignant transformation.
BACKGROUND AND METHODS: Flow cytometric DNA analysis was performed on 30 cases of giant cell tumor (GCT) of bone with the use of paraffin-embedded sections. RESULTS: According to the criteria of Huvos, they were classified histologically into three groups: Grade 1, 26 cases; Grade 2, 4 cases; and Grade 3, no cases. Among the Grade 1 cases, 21 were diploid and 5 were aneuploid. Of the four Grade 2 cases, three were diploid and one was aneuploid. Nine patients had local relapses. Among four patients with complications by lung metastases, two have remained well at 18 and 157 months with the metastases. The other two patients, who had Grade 1 DNA diploid GCT of the 11th thoracic spine, had malignant transformation (osteosarcoma) resulting from radiation therapy. In one patient, the primary lesion exposed to radiation and the lung lesions were diploid, but in the other patient both were found to be aneuploid at autopsy. No significant differences of S-phase fraction were observed between two different grade groups. There was no significant correlation among DNA ploidy, histologic grade, and the presence or absence of lung metastases. CONCLUSIONS: Based on this study, the DNA analysis has a limitation in predicting the biologic behavior of GCT.
Adolescent↗