Cell cycle control in fission yeast and mammals: identification of new regulatory mechanisms.
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Amino Acid Sequence↗
Biomedical subjects
H Murakami
Publications and source records attributed to H Murakami.
Antiepiligrin cicatricial pemphigoid: the first case report from Japan.
We describe a Japanese man with antiepiligrin cicatricial pemphigoid and typical clinical features, including ocular involvement. Direct immunofluorescence showed IgG deposition at the basement membrane zone. Indirect immunofluorescence of 1M sodium chloride-split skin showed circulating antibasement membrane zone antibodies of IgG class reactive with the dermal side of the split. Immunoblotting of human epidermal and dermal extracts, as well as a bacterial fusion protein of BP180 NC16a domain, showed no specific reactivity. In contrast, with immunoprecipitation of either culture medium or cell lysate from normal keratinocytes, the patient's serum clearly reacted with the protein epiligrin, a laminin isoform present in the lamina lucida of the human epidermal basement membrane zone. This is the first confirmed case of a Japanese patient with this disease entity.
Basement Membrane↗
Analysis of antigens recognized by autoantibodies in herpes gestationis. Usefulness of immunoblotting using a fusion protein representing an extracellular domain of the 180 kD bullous pemphigoid antigen.
Herpes gestationis (HG) is a rare pregnancy-associated disease. The aim of this study was to compare various immunohistochemical and immunobiochemical techniques with respect to their diagnostic sensitivity for HG. We studied 43 HG sera; only half of these reacted with the basement membrane zone (BMZ) with both indirect immunofluorescence (IF) and complement IF of normal human skin. 81% of the sera reacted with the epidermal side of 1 M NaCl-split skin. In general, titers of anti-BMZ antibodies in HG sera were lower than those in bullous pemphigoid (BP) sera. Immunoblot analysis of human epidermal extracts showed that 51% of HG sera recognized the 180 kD BP antigen (BP180) and 26% recognized the 230 kD BP antigen (BP230). We also studied the reactivity of HG sera with fusion proteins representing either the NC16a domain of human BP180 or the C-terminal region of mouse BP230. Whereas 79% of HG sera reacted with the BP180 fusion protein, only 5% recognized the BP230 fusion protein. Our results suggest that indirect IF of 1 M NaCl-split skin and immunoblotting of a fusion protein representing the BP180 NC16a domain are more sensitive techniques for the diagnosis of HG than conventional and complement IF or immunoblotting of crude epidermal extracts.
Animals↗
An aggressive nasal lymphoma accompanied by high levels of soluble Fas ligand.
Fas ligand (FasL), either in the membrane bound form or soluble form, has cytotoxic activity against Fas-expressing cells. We report a case of nasal lymphoma accompanied by liver damage and pancytopenia. The serum level of soluble FasL (sFasL) was very high on admission, but rapidly decreased to normal levels after chemotherapy for lymphoma. Liver damage and pancytopenia also improved with the decrease in serum sFasL. Since Fas is expressed on both hepatocytes and haemopoietic cells, these facts suggest that FasL was expressed on lymphoma cells and directly associated with pathogenesis of liver damage and pancytopenia through its cytotoxic activity.
Enzyme-Linked Immunosorbent Assay↗
Intestinal fatty acid-binding protein is a useful diagnostic marker for mesenteric infarction in humans.
BACKGROUND & AIMS: Acute ischemic diseases of the small bowel are lethal emergencies with no reliable diagnostic biochemical tests available. Experimental studies have suggested rat intestinal fatty acid-binding protein (I-FABP) as a serum marker reflecting bowel ischemia; the present study evaluates the human homologue (human I-FABP) as a serum marker for the diagnosis of acute ischemic diseases of the bowel. METHODS: Enzyme immunoassay was applied to determine I-FABP levels in the sera of 96 subjects: 13 preoperative patients with ischemic bowel diseases (5 cases of mesenteric infarction and 8 cases of strangulated obstruction of the small bowel), 35 healthy subjects, and 48 hospitalized patients with acute abdominal pain. RESULTS: Serum I-FABP levels were < 65 ng/mL in healthy subjects. In patients with acute abdominal pain, levels ranged from < 20 to 87 ng/mL (mean, 27.4 ng/mL), not significantly different from findings in healthy subjects. However, patients with ischemic bowel disease showed significantly higher I-FABP levels, ranging from < 20 to 1496 ng/mL (mean, 265.8 ng/mL). All 5 patients with mesenteric infarction showed I-FABP levels of > 100 ng/mL. CONCLUSIONS: I-FABP is a useful biochemical marker for the accurate diagnosis of mesenteric infarction.
Adolescent↗
Rapid analysis of small samples containing forskolin using monoclonal antibodies.
The effective range of the competitive ELISA test for detection of forskolin content in clonally propagated plant organs of Coleus forskohlii using monoclonal antibodies extends from 5ng to 5 micrograms. A correlation between the forskolin accumulation and the growth rate was investigated using the clonally propagated shoots. An increase of forskolin content was noted, beginning at week 6. Flowers, rachises, leaves, stems, tuberous roots, and roots were analyzed. Tuberous roots and the stem base contained higher amounts of forskolin than other organs. The forskolin content in the stem decreased gradually towards the top of the shoot.
Animals↗
Mechanism of ret dysfunction by Hirschsprung mutations affecting its extracellular domain.
Hirschsprung disease (HSCR) is a congenital disorder associated with the absence of intrinsic ganglion cells in the distal gastrointestinal tract. Recently, many missense, nonsense and frameshift mutations of the ret proto-oncogene were found in familial and sporadic cases of HSCR. Consistent with the view that the HSCR phenotype is the result of inactivation of Ret, the missense mutations detected in the tyrosine kinase domain were demonstrated to result in a marked decrease of the kinase activity of Ret. However, the effects of missense mutations found in the extracellular domain remain unknown. We now report that five mutations in the extracellular domain examined inhibit transport of the Ret protein to the plasma membrane. As a consequence, they significantly decreased the transforming activity of Ret with multiple endocrine neoplasia (MEN) 2A mutation for which cell surface expression is required. Our results also demonstrated that long segment HSCR mutations more severely impair transport of Ret to the plasma membrane than a short segment HSCR mutation, suggesting that the level of its cell surface expression may correlate to the HSCR phenotype.
Biological Transport↗
LFA-1 (CD11a/CD18) and ICAM-1 (CD54) antibodies attenuate superoxide anion release from polymorphonuclear leukocytes in rats with experimental acute pancreatitis.
The inhibitive effects of anti-CD11a/CD18 (LFA-1) and anti-CD54 (ICAM-1) antibodies on the generation of superoxide anion (O2-) by polymorphonuclear leukocytes (PMNs) was elucidated in rats induced with experimental acute pancreatitis. We investigated the generation of O2- by PMNs in two protocols: in the first, we measured the active oxygen-producing ability of PMNs isolated from blood in normal rats; in the second, we measured it from blood, peritoneal cavity, and bronchial alveolar lavage fluid in rats 3 h after the induction of pancreatitis. In normal rats, although LFA-1 antibody attenuated the generation of O2-, ICAM-1 antibody did not. However, in pancreatitis rats, both LFA-1 and ICAM-1 antibodies reduced the generation of O2- by PMNs isolated from blood and the peritoneal cavity. These results showed not only that both LFA-1 and ICAM-1 antibodies have a protective effect on the generation of O2-, but also that LFA-1 has a direct inhibitive effect on the generation of O2- by PMNs in this model. Furthermore, histological studies showed there to be less neutrophil accumulation in the lungs of LFA-1- and ICAM-1-treated animals compared to control animals.
Acute Disease↗
Effects of perfluorochemical-based artificial blood compounds in discordant xenotransplantation.
Fluosol-DA and FC43 emulsion were developed as red blood cell substitutes. However, these perfluorochemical (PFC)-based compounds are not very promising because of their immunosuppressive effects. Therefore we used these compounds as immunosuppressive agents in guinea pig-to-rat discordant heart xenotransplantations. In rats treated with these compounds (5 microliters/g body weight), rhythmic beating of the hearts was maintained for 265.7 +/- 50.3 min (Fluosol-DA-treated group) and 424.3 +/- 40.1 min (FC43 emulsion-treated group), respectively whereas the untreated heartbeat lasted for only 15.5 +/- 6.6 min. In the xenografted heart treated with PFC compounds, no pathologic changes, such as multiple coronary thromboses due to hyperacute rejection, had occurred by 3-4 h after reperfusion, and the endothelial cells were well preserved. We conclude that these PFC compounds can prolong the survival time of guinea pig heart xenografts by inhibiting thrombus formation in the xenografted heart.
Analysis of Variance↗
Specific detection of anti-cell surface antibodies in herpes gestationis sera.
We examined 42 herpes gestationis sera with immunofluorescence of normal human skin sections, and found that anti-keratinocyte cell surface antibodies were detected specifically in 10 herpes gestationis sera. The diagnosis of these herpes gestationis cases was confirmed by detecting antibodies against the 180 kD bullous pemphigoid antigen with immunoblotting of its fusion protein. The results of immunoadsorption assay using baculoproteins of both pemphigus vulgaris and pemphigus foliaceus antigens indicated that the herpes gestationis sera did not recognize common pemphigus antigens. Immunoblotting of human epidermal extracts and immunofluorescence of various tissues also suggested that the sera did not recognize any other desmosomal components or paraneoplastic pemphigus antigens. The significance of this reactivity is unclear. However, because no control bullous pemphigoid sera showed this reactivity, it may suggest a different pathophysiology between herpes gestationis and bullous pemphigoid.
Antigens, Surface↗
Effects of NO on baroreflex control of heart rate and renal nerve activity in conscious rabbits.
Recent data suggest that nitric oxide (NO) plays a role in the modulation of sympathetic nerve activity and baroreflex sensitivity. Most of these studies have been carried out in anesthetized preparations, and little if any comparison has been made on the relative role of NO on the baroreflex control of heart rate and sympathetic nerve activity. In the present studies, the effect of the NO synthase inhibitor NG-nitro-L-arginine (L-NNA) on the baroreflex control of heart rate (HR) and renal sympathetic nerve activity (RSNA) were investigated in conscious, instrumented rabbits. Intravenous bolus injections of 13 mg/kg of L-NNA decreased baseline HR (from 205.0 +/- 6.0 to 145.5 +/- 8.2 beats/min; P < 0.05) without significant changes in mean arterial pressure (MAP) and RSNA. L-NNA significantly reduced the lower plateau of the HR-MAP curves and increased the sensitivities of baroreflex control of HR and RSNA. L-Arginine (600 mg/kg i.v.) but not D-arginine reversed the above effects. The effects of L-NNA on baseline HR were not completely blocked by metoprolol (2 mg/kg) or by atropine (0.2 mg/kg). After pretreatment with metoprolol, baroreflex sensitivity was reduced and L-NNA increased baroreflex sensitivity back to the control level. After pretreatment with atropine, L-NNA still reduced the lower plateau but did not significantly affect baroreflex sensitivity. L-NNA increased the HR responses but not the RSNA response to electrical stimulation of the aortic nerve in chloralose-anesthetized, sinoaortic-denervated (SAD) rabbits. L-NNA had no effect on the HR response to right vagal stimulation. In both conscious intact and SAD rabbits, L-NNA did not increase baseline RSNA. These results suggest that endogenous NO decreases baroreflex control of HR and RSNA. Both sympathetic and parasympathetic components play a role in the effects of NO on the baroreflex control of HR. The effects of NO in the central nervous system play a more important role in the baroreflex control of HR than of RSNA.
Animals↗
Blockade of AT1 receptors enhances baroreflex control of heart rate in conscious rabbits with heart failure.
Because the renin-angiotensin system is activated in heart failure, we hypothesized that angiotensin II (ANG II) plays a role in altering baroreflex sensitivity in the setting of heart failure. Accordingly, we evaluated the baroreflex control of heart rate (HR) in conscious, chronically instrumented rabbits in the normal state and after the establishment of heart failure. Heart failure was induced by rapid ventricular pacing at a rate of 360-380 beats/min for an average of 14.5 +/- 1.4 days. The data were compared with normal rabbits instrumented in a similar fashion. Baroreflex curves were generated by inflation of implanted hydraulic occluders on the vena cava and aortic arch or by administration of phenylephrine and sodium nitroprusside. Experiments were carried out before and after intravenous administration of the AT1 antagonist L-158,809. Rabbits with heart failure exhibited significantly lower arterial pressure (81 +/- 3 vs. 69 +/- 4 mmHg, P < 0.05), elevated resting HR (230 +/- 5 vs. 260 +/- 10 beats/min, P < 0.05), and elevated left atrial pressure (3.6 +/- 0.7 vs. 13.1 +/- 0.7 mmHg, P < 0.05). ANG II blockade had little effect on resting or baroreflex parameters in normal rabbits. However, in rabbits with heart failure, L-158,809 enhanced baroreflex sensitivity (2.7 +/- 0.5 vs. 4.7 +/- 0.8 beats.min-1.mmHg-1; P < 0.05), primarily by increasing the minimum HR evoked during baroreceptor activation. beta 1-Blockade had no effect on any baroreflex parameter after L-158,809 in rabbits with heart failure. However, L-158,809 significantly reduced the minimum HR after pretreatment with atropine in rabbits with heart failure. These data suggest that ANG II plays a role in modulation of cardiac sympathetic tone in this model of heart failure and may be responsible for the depressed baroreflex sensitivity observed in heart failure.
Angiotensin Receptor Antagonists↗
Randomized trials between behenoyl cytarabine and cytarabine in combination induction and consolidation therapy, and with or without ubenimex after maintenance/intensification therapy in adult acute myeloid leukemia. The Japan Leukemia Study Group.
PURPOSE: We analyzed complete remission (CR), disease-free survival (DFS), and event-free survival (EFS) rates in two groups of patients treated with either N4-behenoyl-1-beta-D-arabinosylcytosine (BHAC) or cytarabine, and analyzed DFS with or without ubenimex, a biologic response modifier. PATIENTS AND METHODS: Newly diagnosed patients with acute myeloid leukemia (AML) were randomized to receive either BHAC or cytarabine as remission-induction combination chemotherapy and two courses of consolidation therapy. After maintenance/intensification therapy, patients in CR were randomized to receive either ubenimex and no drug. RESULTS: Of 341 patients registered, 326 were assessable. The age of assessable patients ranged from 15 to 82 years (median, 48). The overall CR rate was 77%: 72% in the BHAC group and 81% in the cytarabine group, and there was a significant difference between the two groups (P = .035, chi 2 test). The predicted 55-month EFS rate of all patients was 30%: 23% in the BHAC group and 35% in the cytarabine group, with a significant difference between groups (P = .0253). The predicted 55-month DFS rate of all CR patients was 38% and that of CR patients less than 50 years of age was 47%. There was no significant difference in DFS between the ubenimex group and the group that did not receive ubenimex. CONCLUSION: Analyses of our clinical trial showed that the use of BHAC in remission-induction therapy and in consolidation therapy resulted in poorer CR and EFS rates in adult AML patients compared with the use of cytarabine at the doses and schedules tested. Immunotherapy with ubenimex after the end of all chemotherapy did not improve DFS.
Acute Disease↗
Effects of cyclic adenosine 3',5'-monophosphate on chondrocyte terminal differentiation and cartilage-matrix calcification.
We examined the effects of cyclic AMP on terminal differentiation and calcification in rabbit growth plate chondrocyte cultures. Dibutyryl cAMP (dbcAMP), as well as 8-bromo-cAMP abolished the increases in chondrocyte size, alkaline phosphatase activity, type X collagen synthesis, 1 alpha, 25-dihydroxyvitamin D3 receptor synthesis, the incorporation of 45Ca into insoluble material, and the calcium content. All of these occurred in parallel untreated cultures during the hypertrophic (terminal) stage. The inhibition of alkaline phosphatase by dbcAMP was detectable after 24 h, and this effect was reversible. dbcAMP and 8-bromo-cyclic AMP inhibited alkaline phosphatase induction and calcification at low concentrations (3-5 microM), whereas 10-30-fold higher concentrations were required to stimulate proteoglycan synthesis. These findings suggest that cAMP plays a crucial role in suppressing terminal differentiation of chondrocyte and cartilage-matrix calcification.
8-Bromo Cyclic Adenosine Monophosphate↗
Analysis of candidate genes for insulin resistance in essential hypertension.
To clarify the genetic basis of insulin resistance in hypertension, case-control association studies were performed to examine candidate genes for insulin resistance in hypertension. Since the main site of insulin resistance in hypertension is glycogen synthesis in skeletal muscle, genes that encode molecules involved in this pathway, i.e. insulin receptor (INSR), insulin-responsive glucose transporter (GLUT4) and glycogen synthase (GSY), were studied. In addition, since recent studies suggest the contribution of beta3 adrenergic receptor to the insulin resistance syndrome, the gene encoding beta3 adrenergic receptor (ADRB3) was also studied. Frequency of homozygotes for common C allele of a microsatellite polymorphism in the INSR gene was higher in the hyperinsulinemia group, but not in the normoinsulinemia group of hypertensive patients than in normotensive control subjects. Insulin sensitivity, however, was not significantly different between hypertensive patients with C/C genotype and those without this genotype. No significant differences were observed in the distribution of alleles or genotypes of the GLUT4, GSY and ADRB3 genes between hyperinsulinemia and normoinsulinemia groups of hypertensive patients or between these groups and the control group. These data suggest that the INSR polymorphism is associated with hyperinsulinemia, but not with insulin resistance, in hypertension.
Case-Control Studies↗
Tumor necrosis factor-alpha and interleukin 4 in myeloma cell precursor differentiation.
Multiple myeloma is a B-cell malignancy characterized by the accumulation of a clonal population of plasma cells in the bone marrow that secrete a monoclonal immunoglobulin protein. It has been regarded as a tumor arising at the B, pre-B lymphocyte, or even stem cell level. Precursor cells are presumed to proliferate and differentiate, giving rise to clonal expansion in plasma cells. Peripheral blood mononuclear cells (PBMC) from 36 patients with multiple myeloma, 12 with monoclonal gammopathy of undetermined significance (MGUS), and 21 healthy controls were cultured in vitro in the presence of tumor necrosis factor-alpha (TNF-alpha) and interleukin 4 (IL-4). We have demonstrated that monoclonal plasma cells can be induced in different proportions from PBMC obtained from myeloma patients when exposed in vitro to TNF-alpha and IL-4. Although myeloma cell precursors cannot be distinguished from other cells by morphology, a high number of monoclonal plasma cells was detected in our culture system on day 4 even when plasma cells accounted for less than 0.2% of the cells seeded on day 0. In 16 of the 36 patients with myeloma, monoclonal plasma cells appeared after 4 days. These changes were not observed in PBMC from patients with MGUS or from controls. These findings thus suggest that circulating myeloma cell precursors differentiate into plasma cells in the presence of TNF-alpha and IL-4, and the variation in the number of myeloma cell precursors in peripheral blood could therefore be used as a prognostic parameter in response to chemotherapy in myeloma patients.
Cell Differentiation↗
The mechanisms of the improvement of insulin sensitivity by angiotensin converting enzyme inhibitor.
To investigate the role of kinins in augmentation of insulin sensitivity by angiotensin converting enzyme inhibitor (ACEI), the effects of ACEI (delapril) on the insulin resistance in fructose-fed rats (FFR) were evaluated with or without the administration of bradykinin receptor antagonist (Hoe 140). Male Sprague-Dawley rats were fed on fructose rich chow (FFR) or standard chow (control) for 4 weeks and treated with 10 mg/kg/day of delapril with or without Hoe 140 (0.5 mg/kg/day) for an additional 2 weeks. Steady state plasma glucose (SSPG) and steady state plasma insulin (SSPI) were determined while the rats were conscious. Insulin (2.5 mU/kg/min) and glucose (8 mg/kg/min) were simultaneously infused to determine insulin sensitivity in each group. Mean blood pressure (MBP), SSPG and SSPI were significantly higher in FFR than in control, and were significantly lower in the FFR+delapril than in FFR+vehicle. There were no difference in MBP, SSPG and SSPI between FFR+delapril+vehicle and FFR+delapril+Hoe 140. We concluded that the main mechanisms of improving the insulin sensitivity by ACEI may not be the enhancement of kinins but the suppression of angiotensin II in FFR.
Angiotensin-Converting Enzyme Inhibitors↗
[Autoimmune hemolytic anemia with eosinophilia in elderly patient].
A 70-year-old woman was admitted to our hospital in November 1992 for evaluation of anemia. Physical examination revealed anemia, jaundice, swelling of axial and inguinal lymph nodes, and splenomegaly. Abnormal hematological findings were as follows: Hb of 3.9 g/dl, reticulocyte count of 58.2% (61.7 x 10(4)/microliters), hyperplasia of normal erythroblasts in bone marrow, and eosinophilia (21.0%, 2352/microliters) in peripheral blood. Routine laboratory examinations revealed polycolonal hypergammaglobulinemia 3.0 g/dl, a high level of serum LDH (797 IU/I) and a total bilirubin of 2.4 mg/dl (indirect, 1.6 mg/dl). The serum haptoglobin level was very low (< 5 mg/dl). Results of serological examinations were as follows: IgG of 3366 mg/dl, CH50 of 16.0 U/ml, positive Coombs test 2+, and positive tests for antinuclear antibody, rheumatoid factor, and cold agglutinin. CRP was negative. PHA-stimulated lymphocyte blast formation, NK activity, and ADCC activity were found to be suppressed, and the percentage of CD4-positive lymphocytes in peripheral blood was also low. An axillary lymph node biopsy revealed reactive lymphadenitis. No signs or history suggested allergy, collagen disease, or parasitic infection. Autoimmune hemolytic anemia (AIHA) complicated by immunologic abnormalities and eosinophilia was diagnosed. Oral prednisolone markedly reduced the hemolytic anemia, eosinophilia, lymph node swelling, and splenomegaly, but NK activity remained low.
Aged↗