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Biomedical subjects

S Fujii

Publications and source records attributed to S Fujii.

At least 505 records · Page 28Linked to original sources
PubMed1992

Cranio-nasal median splitting for radical resection of craniopharyngioma.

A new surgical approach for radical resection of craniopharyngioma is presented. This approach (cranio-nasal median splitting) involves craniotomy in the centre of the frontal bone, removal of the median portion of the supraorbital bar that incorporates the nasal bone, and detachment of the medial canthal ligaments. The frontal lobes, the cribriform plates, the planum sphenoidale, and the upper nasal cavities are split in the midline. The extraventricular surface of the hypothalamus, the pituitary stalk, and the posterior portion of the Willis' arterial ring are well visualized through the midline infrachiasmatic route. The intraventricular surface of the hypothalamus is also visible in the same operative field through the lamina terminalis and/or the anterior portion of the corpus callosum. This excellent visualization is quite helpful for minimizing operative injury to the hypothalamus and the pituitary stalk whichever surface of the third ventricular floor the tumour is situated upon. Three cases of craniopharyngioma operated upon by this approach are presented. Discussions are focused not only on the indication, but on the advantages and disadvantages of this approach. The surgical techniques for reconstruction of the cranial base are also described, together with some precautions that should be taken to prevent possible postoperative complications.

Adult↗
PubMed1992

Dysregulation of adult T-cell leukemia-derived factor (ADF)/thioredoxin in HIV infection: loss of ADF high-producer cells in lymphoid tissues of AIDS patients.

Adult T-cell leukemia (ATL)-derived factor (ADF) is a multifunctional protein homologous to thioredoxin (TRX) with co-cytokine and thiol-dependent reducing activities. ADF/thioredoxin production is enhanced in T cells transformed by HTLV-I. We have examined the effect of HIV-1 infection on ADF/TRX expression using specific antibody against ADF/TRX. Lymph nodes from 5 AIDS and 1 AIDS-related complex (ARC) patients were examined. As a control, 8 HIV noninfected lymph nodes, including 3 cases with hyperplasia, were also examined. Immunohistopathological studies using normal HIV noninfected lymph nodes showed that ADF/TRX high-producer (ADFh) cells were macrophages and cells with dendritic morphology in the paracortical area. Abundant ADFh cells were observed in HIV noninfected hyperplastic lymph nodes. The number of ADFh cells was low in hyperplastic lymph nodes from an ARC patient. All of the lymph nodes of 5 AIDS cases were atrophic and the number of ADFh cells were extremely low. To verify these histochemical studies, we examined the effect of in vitro HIV infection on ADF/TRX expression in HTLV-I (+) T-cell lines. Western blot analysis showed that a reduction of ADF/TRX in HIV-1-infected SKT-1B and MT-2 cells, and the reduction inversely correlated with p24 antigen level. On the basis of the above in vivo and in vitro findings, we imply that the levels of ADF/TRX were down-regulated by HIV-1 infection and that the down-regulation may play a role for pathophysiology of HIV-infected individuals.

AIDS-Related Complex↗
PubMed1992

Resonance Raman study on complexes of medium-chain acyl-CoA dehydrogenase.

Resonance Raman (RR) spectra of the complex of pig kidney medium-chain acyl-CoA dehydrogenase with acetoacetyl-CoA and of the purple complex formed upon the addition of octanoyl-CoA to the dehydrogenase were obtained. RR spectra were also measured for the complexes prepared by using isotopically labeled compounds, i.e., [3-13C]-, [1,3-13C]-, and [2,4-13C2]acetoacetyl-CoA; [1-13C]octanoyl-CoA; the dehydrogenase reconstituted with [4a-13C]- and [4,10a-13C2]FAD. Both bands of oxidized flavin and acetoacetyl-CoA were resonance-enhanced in the 632.8 nm excited spectra of the acetoacetyl-CoA complex; this confirms that the broad long-wavelength absorption band is a charge-transfer absorption band between oxidized flavin and acetoacetyl-CoA. The 1,622 cm-1 band was assigned to the C(3)=O stretching mode coupling with the C(2)-H bending mode of the enolate form of acetoacetyl-CoA and the bands at 1,483 and 1,119 cm-1 were assigned to bands associated with the C(2)=C(1)-O- moiety. Both bands of fully reduced flavin and the substrate were resonance-enhanced in the 632.8 nm excited spectra of the purple complex. As the enzyme is already reduced, the substrate must be oxidized to octenoyl-CoA; the complex is a charge-transfer complex between the reduced enzyme and octenoyl-CoA. The low frequency value of the 1,577 cm-1 band, which is associated with the C(2)-C(1)=O moiety of the octenoyl-CoA, suggests that the enzyme-bound octenoyl-CoA has an appreciable contribution of C(2)=C(1)-O-.(ABSTRACT TRUNCATED AT 250 WORDS)

Acetyl Coenzyme A↗
PubMed1992

Direct evidence for a basolateral membrane Cl- conductance in toad retinal pigment epithelium.

There is now evidence that a Cl- conductance on the basal membrane of the retinal pigment epithelium (RPE) is involved in the generation of both the fast oscillation and the light peak of the direct-current electroretinogram as well as being critical for transepithelial fluid and salt movement. In the present study, we characterized the basolateral membrane Cl- conductance of an in vitro preparation of toad RPE-choroid using conventional and Cl(-)-selective microelectrodes. Under control conditions, the potential across the apical (Vap) and basal (Vba) membranes averaged -60 +/- 2 and -45 +/- 2 mV, respectively (n = 40). Intracellular Cl- activity (aiCl = 20 +/- 1 mM) was distributed above equilibrium across both membranes, consistent with active accumulation of Cl-. A sixfold decrease in Cl- in the basal bath depolarized Vba by 12 +/- 1 mV (n = 17) and increased the apparent basal membrane resistance. By sequential measurement of aiCl and subepithelial Cl- activity during a step decrease in basal Cl-, we constructed the change in Cl- equilibrium potential (ECl) across the basal membrane. Estimation of the change in basal membrane electromotive force during the change in ECl gave an average value for the Cl- transference number (TCl) of 0.45. Further evidence for a Cl- conductance was obtained by measuring changes in aiCl induced by transepithelial current. Depolarizing Vba elevated aiCl, whereas hyperpolarizing Vba had the opposite effect, consistent with conductive Cl- movement across the basal membrane. Both the amplitude of the Cl- diffusion potential and the current-induced changes in aiCl were reduced by basal perfusion with 4,4'-diisothiocyanostilbene-2,2'-disulfonic acid (250-500 microM), a blocker of Cl- channels in some epithelia.

4,4'-Diisothiocyanostilbene-2,2'-Disulfonic Acid↗
PubMed1992

Augmented arterial wall expression of type-1 plasminogen activator inhibitor induced by thrombosis.

Type-1 plasminogen activator inhibitor (PAI-1), the primary physiological inhibitor of endogenous plasminogen activators, modulates fibrinolysis, cell migration, and tissue repair. To determine whether genetic expression of PAI-1 is augmented in the walls of vessels exposed to thrombi but not to a direct physical insult such as electrical injury, we induced arterial thrombosis in rabbit carotid arteries with intraluminal surgical silk sutures and performed in situ hybridization for PAI-1 messenger RNA (mRNA) and immunohistochemistry for PAI-1 antigen at selected intervals. PAI-1 activity in plasma remained virtually constant. In contrast, PAI-1 mRNA increased in endothelial cells juxtaposed to thrombi, in smooth muscle cells adjacent to the neointima, and in macrophages surrounding the suture material. PAI-1 protein was detected in regions in which PAI-1 mRNA was expressed. The increased expression of PAI-1 mRNA colocalized with PAI-1 protein in the endothelium juxtaposed to thrombi may potentiate thrombosis by shifting the local balance between fibrinolysis and thrombosis toward thrombosis. Furthermore, it may alter vascular remodeling and predispose to stenosis after interventions such as angioplasty, in which local thrombosis cannot be avoided.

Animals↗
PubMed1992

Direct effects of gemfibrozil on the fibrinolytic system. Diminution of synthesis of plasminogen activator inhibitor type 1.

BACKGROUND: Platelet-associated epidermal growth factor (EGF) and transforming growth factor-beta (TGF-beta) can augment synthesis of plasminogen activator inhibitor type 1 (PAI-1). Accordingly, exacerbation of atherogenesis may accompany release of platelet-associated growth factors (or mitogens) occurring in association with occult, repetitive thrombosis and thrombolysis. In the Helsinki primary prevention trial, gemfibrozil decreased coronary events but did so essentially only in initially hypertriglyceridemic subjects. Such subjects are known to exhibit high concentrations of PAI-1 in plasma. METHODS AND RESULTS: To determine whether pharmacological concentrations of gemfibrozil directly affect PAI-1 synthesis, we characterized its effects on a human hepatoma cell line (Hep G2) in vitro. Gemfibrozil decreased basal PAI-1 secretion by 43% and attenuated the augmentation of PAI-1 synthesis over 24 hours induced by EGF and TGF-beta by 37% and 39% without altering overall protein synthesis. Furthermore, it blocked the EGF and TGF-beta-induced increases in PAI-1 mRNA over 6 hours by 65% and 60%. Increases in plasma PAI activity induced by infusion of purified growth factors or by autologous platelet lysates in rabbits were inhibited by gemfibrozil by more than 50%. CONCLUSIONS: Beneficial effects of gemfibrozil in reducing coronary events in hypertriglyceridemic patients may depend, in part, on potentiation of fibrinolysis by direct diminution of synthesis of endogenous PAI-1.

Blood Platelets↗
PubMed1992

Induction of endothelial cell expression of the plasminogen activator inhibitor type 1 gene by thrombosis in vivo.

BACKGROUND: We have shown previously that products from activated platelets can augment synthesis of plasminogen activator inhibitor type 1 (PAI-1) in cultured endothelial and hepatoma (Hep G2) cells in vitro and increase plasma PAI-1 activity in vivo in rabbits. Accordingly, the effects of activation of platelets associated with thrombosis and thrombolysis in vivo on plasma PAI-1 activity and expression of the PAI-1 gene in endothelium, liver, and other organs were characterized. METHODS AND RESULTS: Endothelial injury giving rise to platelet-rich thrombi was induced with electrical stimulation in carotid arteries in rabbits. Clot lysis and recanalization were induced subsequently with intravenous tissue-type plasminogen activator (t-PA) and verified with Doppler flow probes. Plasma PAI-1 activity (mean +/- SD) increased from 6 +/- 2 arbitrary units (AU)/ml to 129 +/- 48 AU/ml (n = 15) within several hours after recanalization. When t-PA had failed to induce recanalization, the increase was much less (from 7 +/- 2 to 42 +/- 23 AU/ml, n = 11). To define mechanisms responsible for these changes, PAI-1 messenger RNA (mRNA) was evaluated by Northern blot analysis and localized in tissues by in situ hybridization. Strong and consistent induction of PAI-1 mRNA was evident in aorta, heart, and liver of animals subjected to thrombosis (twofold to threefold increases compared with values in controls), particularly in those in which thrombolysis had been induced (fourfold to sixfold). After thrombolysis, an intense, PAI-1 mRNA-specific signal was detected in endothelium of aorta, liver, and heart, with less intense signals in endothelium of lung, adrenals, and kidneys. CONCLUSIONS: The increases in plasma PAI-1 activity follow a preceding increase in endothelial cell expression of the PAI-1 gene as reflected by PAI-1 mRNA levels. Thus, increased synthesis of endothelial cell PAI-1 after thrombosis and thrombolysis may attenuate endogenous fibrinolysis early after coronary thrombolysis, thereby potentiating early, thrombotic reocclusion.

Animals↗
PubMed1992

Effects of mushroom toxins on glycogenolysis; comparison of toxicity of phalloidin, alpha-amanitin and DL-propargylglycine in isolated rat hepatocytes.

The effects of phalloidin and alpha-amanitin as toxins of Amanita species and DL-propargylglycine identified from A. abrupta on the glycogenolysis in isolated rat hepatocytes were investigated. Phalloidin decreased glycogen content and activated phosphorylase a activity remarkably. alpha-Amanitin also decreased glycogen content significantly but activated phosphorylase a activity slightly. DL-Propargylglycine slightly affected glycogenolysis. Phalloidin, which most affected glycogenolysis among the three compounds mentioned above, elevated cytosolic Ca2+ concentration ([Ca2+]i) and 45Ca uptake into cells. Phalloidin depressed slightly 3H-inositol incorporation into phosphatidylinositol (PI) and remarkably phosphatidylinositol 4,5-bisphosphate (PIP2) but increased phosphoinositides breakdown. These results suggest that phalloidin alters phosphoinositides turnover and intracellular Ca2+ homeostasis, subsequently activates phosphorylase a, resulting in glycogenolysis in isolated rat hepatocytes.

Alkynes↗
PubMed1992

Anthracycline metabolites from baumycin-producing Streptomyces sp. D788. I. Isolation of antibiotic-blocked mutants and their characterization.

Biosynthetically blocked mutants were obtained from a baumycin-producing Streptomyces sp. D788 newly isolated from soil. The first mutant isolated was a baumycin-negative but daunorubicin-accumulating mutant with a loss of 4'-substitution activity, from which all other blocked mutants were successively derived. These included a known 11-deoxydaunorubicin-producing mutant and several new types of mutants which produced mainly 10-carboxy-13-deoxocarminomycin, 10-methoxycarbonyl-13-deoxocarminomycin, their 11-deoxy derivatives or a precursor aglycone, respectively. In this paper, all the anthracycline components produced by the parent strain and its two known blocked mutants, a daunorubicin producer and a 11-deoxydaunorubicin producer, are also determined by HPLC and five new components are isolated. Cytotoxicities in vitro of all the components against L1210 cell culture are also described.

Animals↗
PubMed1992

Conformational features of the four successive non-Watson-Crick base pairs in RNA duplex.

A tridecaribonucleotide, r(UGAGCUUCGGCUC) doesn't form hairpin or interior loop and forms a double helix of 12 base pairs including the four successive nonstandard base pairs, U.G-U.C-C.U-G.U, in the crystal. Non-Watson-Crick base pairs, G.U and U.C are nicely incorporated in RNA duplex maintaining the regular A-form backbone. There exist the good overlapping between base pairings, U.G and U.C, so as to stabilize the nonstandard base pair track. Hydrogen bond networks involving water molecules in the major and minor grooves to stabilize this mismatch base pairing array, are observed and its conformational features are described.

Base Composition↗
PubMed1992

[Physical exercise therapy in diabetes mellitus--the role of clinical laboratory examinations].

Physical training has been generally recommended for patients with diabetes mellitus as a basic therapeutic tool. In the present study the metabolic and endocrinological effects during the training program were examined in patients with non insulin dependent diabetes mellitus (NIDDM). Moreover the significance of continuous blood lactate monitoring and that of the determination of plasma atrial natriuretic polypeptide (ANP) during exercise loading in diabetics was also studied. (1) The glucose metabolic clearance rate (MCR) during euglycemic insulin clamp was higher in athletes than in patients with NIDDM and control subjects. (2) MCR increased significantly in the training group after the eight weeks program and a significant relationship between the changes of MCR and those of HbAIc observed. Moreover a decrease in the triglyceride level and increase in the HDL cholesterol level in plasma were significantly related with the improvement of MCR. (3) A continuous blood lactate monitoring system was newly developed. This system was simple and showed good reproducibility. The anaerobic threshold (AT) determined using this system corresponded to that obtained by respiratory gas analysis. It was useful for the determination of the exercise intensity without overloading in patients with diabetes mellitus. (4) The increase of plasma ANP during exercise loading was higher in diabetics than healthy controls, and a significant relationship was found between the increment of ANP during exercise and the diastolic function judged from the echocardiogram in diabetics. In conclusion clinical laboratory examinations and medical checkups are important in the practice of physical exercise therapy in patients with diabetes mellitus.

Adult↗
PubMed1992

The reactivity between rickettsiae and Weil-Felix test antigens against sera of rickettsial disease patients.

Of the sera which were positive to Rickettsia tsutsugamushi by indirect immunoperoxidase test, approximately 80% sera were positive to a Proteus OXK antigen by Weil-Felix test at 10 or more days after the onset of fever, while only 10% sera were positive within 9 days from the onset of fever. In ELISA using the OXK antigen, almost all of the paired sera of tsutsugamushi disease (TD) patients increased on the IgM antibody titres with the rise of their titres by Weil-Felix test, whereas the IgG antibody titres of these sera were unrelated with the titres of Weil-Felix test. We suspect that the reactivity of TD patients sera to the OXK antigen in Weil-Felix test was derived from the reactivity of the IgM antibody against the OXK antigen common with R. tsutsugamushi. The patient sera infected with a Japanese isolate of spotted fever group rickettsia (SFGR) cross-reacted with the Thai Tick Typhus (TTT) strain of SFGR by indirect immunoperoxidase test. In Weil-Felix test, the reactivity of these sera to OX2 antigen were higher than that to OX19 antigen, like the sera infected with other SFGR, except of R. rickettsii. These sera also reacted with TTT and OX2 antigens by ELISA. The titres of IgM antibody against OX2 antigen in the sera in ELISA were in parallel with the titres of the sera against OX2 antigen in Weil-Felix test, but not the titres of IgG antibody. We suggest that the reactivity of the patient sera infected with SFGR to OX2 antigen of Weil-Felix test is dependent on the IgM antibody.

Antigens, Bacterial↗
PubMed1992

Adult T-cell leukaemia-derived factor/thioredoxin expression on the HTLV-I transformed T-cell lines: heterogeneous expression in ALT-2 cells.

Adult T-cell leukaemia (ATL)-derived factor (ADF), originally described as an inducer of interleukin-2 receptor-alpha (IL-2R alpha/Tac), has homology with the co-enzyme thioredoxin which is involved in many dithiol-dependent reducing processes. Using antibody against the C-terminal synthetic polypeptide of ADF and RNA probe of ADF, we examined the expression of ADF in various cell lines by immunofluorescence, immunohistochemical staining, Western blotting and in situ hybridization. ADF was intensely expressed on HTLV-I+ T-cell lines as compared with HTLV-I- T-cell lines. While the Epstein-Barr virus (EBV)+ B-lymphoblastoid cell lines were intensely positive for ADF, Burkitt-derived B cell line Jijoye with defective EBV was negative for ADF. Electron microscopic and photomicroscopic analysis of HTLV-I+ ATL-2 cells showed that ADF was localized on both the cell membrane and cytosol. In ATL-2 cells, a marked heterogeneity of ADF expression was observed. In in situ hybridization, heterogeneity of ADF messenger RNA (mRNA) expression was also demonstrated, indicating that ADF expression was regulated in the transcriptional level.

Blotting, Western↗
PubMed1992

[Uterine leiomyoma: pathogenesis and treatment].

The pathogenesis of uterine leiomyoma is controversial. Studies on the development of smooth muscle cells in the endoderm-derive ducts (digestive and urinary tracts) and in the mesoderm-derived ducts (mullerian duct) during the fetal period revealed that the development of smooth muscle in the mesoderm-derived ducts (until at least 30 weeks of gestation) is slower than that of smooth muscle in the endoderm-derived ducts (until 12 weeks of gestation). The undifferentiated cells which proliferate and differentiate into smooth muscle in the uterus during the fetal period thus have a longer duration of unstable period being affected by many maternal environmental factors such as sex steroids and/or growth factors. The undifferentiated cells affected by some unknown maternal factors during the fetal period probably become the progenitor cells of leiomyomas. The progenitor cells of leiomyomas probably reside in the myometrium and begin to grow after menarche, and thrive during the years of greatest ovarian activity under the hormonal influence of both estrogen and progesterone, and following the menopause, with regression of ovarian steroids, growth of leiomyomas usually ceases. The growth pattern of leiomyomas indicates that LH-RH analogue, which induces temporal regression of ovarian steroids, becomes one of candidates for the conservative treatment of uterine leiomyomas. However, if we may treat leiomyomas with drugs, the definite diagnosis of uterine leiomyoma is essential. Magnetic resonance imaging (MRI) is a powerful diagnostic method for uterine leiomyomas. MRI gives us an information of the location and numbers of leiomyoma in the uterus. Moreover, it also informs us the characteristics of leiomyomas.(ABSTRACT TRUNCATED AT 250 WORDS)

Estrogens↗
PubMed1992

[Right coronary spasm immediately after coronary artery bypass grafting for the left coronary artery].

Right coronary spasm immediately after coronary artery bypass grafting for the left coronary artery in a 39-year-old male is described. After the patient was returned to ICU, ECG at leads II, III, and aVF changed suddenly, ventricular tachycardia (right ventricle origin) and cardiac arrest ensured. As neither administration of drug nor application of D.C. was effective. The chest was reopened at ICU. Though there was sufficient flow in the left coronary artery bypass graft flow, the right ventricle did not constrict at all. Right coronary artery spasm was diagnosed, and, upon application of the direct cardiac massage and D.C. at the cardiac surface, cardiac rhythm and blood pressure were normalized. IABP was inserted to improve cardiac function, and the chest was closed. In addition, nitroglycerin and diltiazem were infused continuously. No spasm has occurred after this episode, and the patient has been discharged and is doing well.

Adult↗
PubMed1992

[Successful treatment of adenocarcinoma of the lung with bone metastases by combined chemotherapy with epirubicin, mitomycin C and carboplatin].

A 62-year-old male was admitted with lumbago and gait disturbance for 3 months. He had complained of a cough for 3 years. His admission chest radiography revealed tumor shadow in right lower lung field. The patient was diagnosed as adenocarcinoma of the lung by transbronchial biopsy. Bone scintigraphy revealed multiple bone metastases with rib, lumbar and pelvic bone. Clinical staging was IV and performance status was 3. The patient was treated by combined chemotherapy with epirubicin 20 mg/m2, mitomycin C 8 mg/m2 and carboplatin 350 mg/m2. After 2 cycles he was able to walk by himself and the lung tumor regressed in 40% of pretreated size. This combined chemotherapy could be performed for outpatients because of the mild gastrointestinal side effects and little hydration.

Adenocarcinoma↗