Influence of the isotope ratio on the lattice constant of diamond.
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Journal Article↗
Biomedical subjects
S Morimoto
Publications and source records attributed to S Morimoto.
Trichosporon cutaneum fungemia in patients with acute myeloblastic leukemia and measurement of serum D-arabinitol, Candida antigen (CAND-TEC), and beta-D-glucan.
Two patients with acute myeloblastic leukemia are described who developed fungemia due to Trichosporon cutaneum. Fungemia occurred at the leukocyte nadir following the administration of anti-cancer chemotherapy. One patient was cured but the other died. Both patients received prednisolone continuously and had central venous catheters in place for parenteral hyperalimentation. T. cutaneum isolates were resistant to 5-fluorocytosine and moderately susceptible to fluconazole. One case was complicated by endophthalmitis due to T. cutaneum; this is the second report of such a complication in the world. We investigated the serum levels of beta-D-glucan, D-arabinitol, and Candida antigen (CAND-TEC); beta-D-glucan was elevated in both cases, which suggests that simultaneous measurements of these laboratory values are useful for the diagnosis and possibly for the evaluation of therapy for this fungal infection.
Antigens, Fungal↗
Differences in potency of big endothelin-1-induced pressor action in rat isolated perfused mesenteric artery, hindquarter and lung.
We compared the pressor response to endothelin-1 (ET-1) with that of big endothelin-1 (big ET-1) in mesenteric arteries, hindquarters and lungs of rats. In these three preparations, both peptides caused a concentration-dependent increase in the perfusion pressure. The ratio of big ET-1 concentration to ET-1 concentration needed for causing the same pressor action is different between organs; i.e., a mesentery >> a hindquarter > or = a lung. Exposure to phosphoramidon, a metalloproteinase inhibitor, significantly suppressed the pressor response to big ET-1, in a similar fashion. This suppression is likely to be due to the inhibition of phosphoramidon-sensitive endothelin converting enzyme, since the inhibitor does not suppress an action of ET-1. Apparently there is a difference in potency for phosphoramidon-sensitive vasoconstriction of big ET-1 between organs and presumably regional differences in the functional phosphoramidon-sensitive conversion of big ET-1 in vasculatures.
Animals↗
Intrarenal conversion of big endothelin-1 to endothelin-1 in the rat.
Intravenous (i.v.) or intrarenal arterial (i.r.a.) injection of big endothelin-1 (big ET-1) (1.6 nmol/kg) in anesthetized rats produced a significant increase in mean arterial pressure (MAP), a decrease in renal blood flow (RBF) and an increase in renal vascular resistance (RVR). Although the pressor responses to big ET-1 of i.v. and i.r.a. injection were not significantly different, i.r.a. injection of big ET-1 caused a significantly greater reduction in RBF than that seen with i.v. injection of big ET-1. The effects of i.r.a. injection of the peptide on MAP and RBF were markedly suppressed by phosphoramidon. Big ET-1 caused dose-dependent pressor effects in isolated perfused rat kidney and these pressor effects were significantly suppressed by phosphoramidon. Thus, renal vasculature possesses a phosphoramidon-sensitive endothelin converting enzyme, which may play an important role for the renal hemodynamic regulation.
Animals↗
Post-harvest degradation of carotenoid glucose esters in saffron.
It has been found that an indoor cultivation system of Crocus sativus L. is more favorable with regard to the quality of saffron, as compared to the usual cultivation in an open field. Carotenoid glucose esters increase from the period before blooming and reach the maximum in the full blooming period, and are sensitive for the presence of oxygen, light irradiation, and beta-glucosidase. Moreover, it is evident that storage of saffron at -20 degrees C promotes the constant supply of saffron with a homogeneous pharmacological activity.
Carbohydrate Conformation↗
Role of troponin C in determining the Ca(2+)-sensitivity and cooperativity of the tension development in rabbit skeletal and cardiac muscles.
The role of troponin C in determining the characteristic differences in contraction between fast-twitch skeletal and cardiac muscles was investigated with rabbit skinned psoas fibers and left ventricular trabeculae by exchanging their troponins C using a technique involving extraction and replacement. In both muscle types, skeletal troponin C conferred higher cooperativity on the Ca(2+)-activated tension development than cardiac troponin C, indicating that troponin C plays a crucial role in determining the cooperativity in Ca2+ activation of vertebrate striated muscle. Furthermore, the foreign type of troponin C was found to confer lower Ca2+ sensitivity on the tension development in both fast-twitch skeletal and cardiac muscles than the native type of troponin C. This indicates that the Ca2+ sensitivity of each muscle type is determined by troponin C interactions with other troponin subunits and not by troponin C alone.
Allosteric Regulation↗
Reversible hyperkalemia during antihypertensive therapy in a hypertensive diabetic patient with latent hypoaldosteronism and mild renal failure.
A 66-year-old hypertensive diabetic patient with latent hypoaldosteronism and mild renal failure was treated by adding enalapril, an angiotensin converting enzyme inhibitor, to the furosemide and nifedipine regimen because of an insufficient antihypertensive response for 1 month. Seven days after enalapril addition, the blood pressure was significantly reduced, but frank hyperkalemia occurred with a marked rise in BUN and a slight increase in serum creatinine. Plasma renin activity (PRA) and plasma aldosterone (PA) values remained low before and during enalapril therapy. Transient treatment with sodium polystyrene sulfate after enalapril withdrawal improved the hyperkalemia and renal function, but PRA and PA levels were low. PA and its precursor steroids also responded poorly to graded angiotensin II infusion and rapid ACTH injection. Latent hypoaldosteronism probably predisposed this patient to frank hyperkalemia with progressive dehydration and slightly reduced renal function during antihypertensive therapy.
Aged↗
Bone mineral density of the lumbar spine in psoriatic patients with long term etretinate therapy.
Etretinate has been known to produce a variety of skeletal manifestations when administered for prolonged periods. To study whether osteoporotic changes occurred during the treatment bone mineral density (BMD) was measured by dual energy X-ray absorptiometry in 13 psoriatic patients who received long term etretinate therapy (average 3.7 yrs). The values of BMD of the lumbar spine in these patients were decreased from those of age-matched controls (92.3 +/- 9.7%), p < 0.01), while those in psoriatic patients who received topical corticosteroid applications alone showed no significant decrease. Our findings suggest that long term etretinate intake induces an increased risk of osteoporotic changes.
Absorptiometry, Photon↗
Involvement of transforming growth factor-beta 1 for platelets-induced stimulation of endothelin-1 production.
1. Possible mechanisms by which platelets stimulate the production of endothelin-1 (ET-1) in vascular endothelial cells (EC) were investigated. 2. A supernatant of platelets stimulated the expression of prepro ET-1 mRNA, followed by an increased secretion of ET-1 from cultured EC. These responses were markedly enhanced by pretreatment of the platelets with thrombin, at a concentration which did not influence the ET-1 production in EC. A platelet suspension, separated from cultured EC by a permeable nylon membrane, also markedly stimulated the ET-1 secretion from EC. 3. Endothelin-1 production enhanced by the platelet supernatant, with or without thrombin pretreatment, correlated with the active transforming growth factor-beta 1 (TGF-beta 1) concentrations in the supernatant. The supernatant-induced increase in ET-1 secretion from the EC was markedly suppressed by TGF-beta 1 neutralizing antibody. 4. We tentatively conclude that platelets stimulate the endothelial ET-1 production by releasing a bioactive diffusible substance, mainly TGF-beta 1.
Animals↗
Conversion of big ET-1 in the rat lung: role of phosphoramidon-sensitive endothelin-1-converting enzyme.
We examined conversion of Big endothelin-1 (ET-1) to mature ET-1 and pressor action during perfusion of the isolated perfused rat lung with Big ET-1. Big ET-1 caused a concentration-related increase in perfusion pressure and the pressor molar potency of the peptide was fivefold less than that of ET-1. Pressor responses to Big ET-1 were accompanied by an increase in immunoreactive-ET (IR-ET) levels in the perfusate and in the lung tissues. Pretreatment with phosphoramidon (10(-4) M), a metalloproteinase inhibitor, markedly suppressed the pressor action and increment in IR-ET in the tissues. Unexpectedly, the amount of IR-ET in the perfusate during perfusion of Big ET-1 was not influenced by phosphoramidon treatment. On the other hand, chymostatin, an inhibitor of chymotrypsin-like enzymes, effectively suppressed IR-ET levels in the perfusate; however, this enzyme inhibitor was without effect on the pressor action of Big ET-1 or on the increase in IR-ET levels in lung tissues. We tentatively conclude that the phosphoramidon-sensitive conversion of Big ET-T to ET-1 is linked to the pressor action of Big ET-1 in the isolated perfused rat lung. In addition, it seems likely that chymostatin-sensitive conversion of Big ET-1 to ET-1 does not play a major role in the conversion of the precursor to the mature form. We propose that IR-ET present in the tissues rather than that in the perfusate is a better indicator of the functional conversion of Big ET-1 in the rat lung.
Animals↗
Endothelin-1 in cerebrospinal fluid in elderly patients with hypertension and dementia.
Endothelin-1, a potent endothelium-derived vasoconstrictive peptide, is also known to exist in the central nervous system. We determined endothelin-1-like immunoreactivity in cerebrospinal fluid by a radioimmunoassay in 32 normotensive or hypertensive elderly subjects (79 +/- 8 years old) with or without multi-infarction dementia. The mean value of endothelin-1-like immunoreactivity in cerebrospinal fluid was significantly (P < .05) elevated in subjects with essential hypertension (> or = 160/95 mm Hg, n = 5, 79 +/- 9 years old) compared with those with borderline hypertension (140-159/90-94 mm Hg, n = 4, 78 +/- 5 years old) and normotensive subjects (< 140/90 mm Hg, n = 23, 79 +/- 8 years old). The value of endothelin-1-like immunoreactivity in cerebrospinal fluid was significantly (P < .05) positively correlated with both systolic (r = .38) and diastolic (r = .42) blood pressures in all subjects. On the other hand, mean values of endothelin-1-like immunoreactivity in cerebrospinal fluid were also significantly (P < .05) elevated in the groups of patients with multi-infarction dementia that had profoundly decreased Mini-Mental State scores (< or = 10, n = 6) and moderately decreased Mini-Mental State scores (11 to 20, n = 14) compared with those values in subjects with normal cognitive function (score for Mini-Mental State > or = 21, n = 12).(ABSTRACT TRUNCATED AT 250 WORDS)
Aged↗
Phosphoramidon-sensitive conversion of big endothelin-1 and degradation of endothelin-1 in rat kidney.
We investigated the intrarenal conversion of big endothelin-1 (ET-1) to ET-1 in the isolated perfused rat kidney. Big ET-1 caused a concentration-dependent increase in perfusion pressure, and the pressor molar potency of the peptide was 50-fold less than that of ET-1. The big ET-1 (2 x 10(-8) mol/L)-induced pressor action was accompanied by increases in immunoreactive endothelin levels in both the perfusate and renal tissues. Phosphoramidon (10(-4) mol/L), a metalloproteinase inhibitor, significantly suppressed the big ET-1-induced pressor action and the accumulation of immunoreactive endothelin in renal tissues. On the other hand, phosphoramidon slightly but significantly sustained the ET-1-induced pressor effect. The effect of kelatorphan (10(-4) mol/L), a specific inhibitor of neutral endopeptidase 24.11, on the ET-1-induced pressor effect was the same as that seen with phosphoramidon. When ET-1 was exogenously added to the perfusate, phosphoramidon or kelatorphan significantly increased the immunoreactive endothelin levels in renal tissues after perfusion, without affecting the disappearance rate of immunoreactive endothelin from the perfusate. Therefore, the phosphoramidon-sensitive ET-1-converting enzyme in the kidney seems to contribute to the functional local conversion of big ET-1 to ET-1, and neutral endopeptidase 24.11 may be responsible for the proteolytic degradation of ET-1 in the kidney. In addition, immunoreactive endothelin levels in renal tissues but not in the perfusate can account for the functional conversion of big ET-1 to ET-1 and for the local proteolytic degradation of ET-1 in the kidney.
Animals↗
Structure-activity relationship study of 6-O-methylerythromycin 9-O-substituted oxime derivatives.
In order to develop new-generation macrolide antibiotics active against erythromycin (EM)-resistant strains, a series of 6-O-methyl EM 9-O-substituted oxime derivatives was synthesized and evaluated for antibacterial activity against EM-resistant (S. aureus J-109) and susceptible (S. aureus 209P) strains. To understand how substituents affect the biological activity, the quantitative structure-activity relationships (QSAR) was analyzed using the Hansch-Fujita method. With the EM-resistant strain, the positive coefficient for log P may indicate that higher hydrophobicity of molecules is favorable for antibacterial activity. The negative coefficients of the Sterimol parameters L, B1, and B5 may indicate that long, bulky substituents are unfavorable. With the EM-susceptible strain, the negative coefficient for log P may indicate that hydrophilicity is important for antibacterial activity. A short substituent is also required to improve the activity. Based on the QSAR model, a derivative (87) having an anthracenylmethyl moiety was synthesized to reinforce and confirm the correlation. The activity of 87 against the EM-resistant strain was significant. In QSARs of 6-O-methyl EM-A 9-O-substituted oxime derivatives, the difference of the contribution of log P to the antibacterial activity between EM-resistant and susceptible strains was clearly recognized.
Anti-Bacterial Agents↗
[Rotarod method in young rats and the antidepressive effect: is the rotarod method capable of evaluating antidepressive effects?].
The possibilities of applying the rotarod method in young rats for evaluating the antidepressive effect were studied. The results were compared with those obtained by the despair test, which was also used to evaluate the antidepressive effect. The rats used in these tests had not been trained previously. In the rotarod test, antidepressant drugs such as imipramine (30 mg/kg, p.o.), desipramine (10 mg/kg, p.o.), clorgyline (10 mg/kg, p.o.), mianserin (30 mg/kg, p.o.), trazodone (10 mg/kg, p.o.) and clomipramine (30 mg/kg, p.o.) and an ACE inhibitor, enalapril (30 mg/kg, p.o.), significantly prolonged the time rats were able to remain on the rotating rod in a dose-dependent manner. Diazepam significantly reduced the duration on the rotating rod. Theophylline, caffeine and fenfluramine did not affect the duration on the rotating rod. In the despair test (forced swimming test), clorgyline, enalapril and caffeine significantly reduced the duration of immobility during the forced swimming in a dose-dependent manner. Imipramine and desipramine significantly reduced the duration of immobility during forced swimming. Trazodone and clomipramine did not affect the duration of immobility. Diazepam significantly prolonged the duration of immobility. A highly significant correlation was noted between the results obtained by the rotarod method and those obtained by the despair test. In the traction test, theophylline and caffeine significantly prolonged the duration during the traction response. However, other drugs did not affect the duration during the traction response. These results demonstrate that the rotarod method in young rats may be applicable for evaluating the antidepressive effect.
Animals↗
Increased release of platelet-derived growth factor from platelets in chronic liver disease.
The concentrations of platelet-derived growth factor in serum in 7 healthy controls (61 +/- 9 years; mean +/- SD) and 10 patients (62 +/- 8 years) with chronic liver disease (chronic hepatitis and/or liver cirrhosis) were compared. The plasma concentration of platelet-derived growth factor was below the detection limit (< 0.45 microgram/l) in all the subjects studied. The peripheral blood platelet count in patients with chronic liver disease was significantly lower than that in control subjects. However, the concentration of platelet-derived growth factor in serum, which was assumed to be released from platelet, was similar in patients with chronic liver disease and control subjects. These results indicate that the mean amount of platelet-derived growth factor released from the same number (10(9)) of platelets, calculated from the serum platelet-derived growth factor concentration and the peripheral blood platelet count, in patients with chronic liver disease (33 +/- 11 ng/10(9) platelets) was significantly (p < 0.01) higher than that in control subjects (14 +/- 5 ng/10(9) platelets). Moreover, the amount of platelet-derived growth factor released from 10(9) platelets inversely correlated with the serum concentration of pseudocholinesterase activity (r = -0.65, p < 0.01), and correlated positively (r = 0.91, p < 0.01) with the percent retention of indocyanine green in serum, in all subjects studied. These findings suggest that the amount of platelet-derived growth factor releasable from platelets of patients with chronic liver disease is higher than that in normal subjects and that it correlates with the severity of the disease.(ABSTRACT TRUNCATED AT 250 WORDS)
Aged↗
Association of a nocturnal rise in plasma alpha-atrial natriuretic peptide and reversed diurnal blood pressure rhythm in hospitalized normotensive subjects with non-insulin dependent diabetes mellitus.
Diurnal changes in plasma atrial natriuretic peptide (ANP), plasma renin activity (PRA) and plasma aldosterone as related to those in blood pressure (BP) were studied under hospital conditions in 18 diabetic subjects without proteinuria and 8 age-matched control subjects. Of 18 diabetic subjects, 10 had a normal diurnal BP rhythm with the peak value in the afternoon (group 1) and 8 had a reversed BP rhythm with the peak value during the night (group 2). Autonomic dysfunction estimated by measuring orthostatic BP and heart-rate changes and beat-to-beat heart-rate variations was more pronounced in group 2 than in group 1. Fasting plasma glucose and HbA1c were similarly high in both diabetic groups. Group 1 showed modestly elevated mean 24-h MBP and plasma ANP levels, modestly low mean 24-h PRA and plasma aldosterone levels, and a lack of diurnal ANP changes similar to that in controls. Group 2 showed markedly elevated mean 24-h BP and plasma ANP levels, markedly low mean 24-h PRA and plasma aldosterone levels, and nocturnal rises in plasma ANP and BP. PRA and plasma aldosterone exhibited circadian rhythms with their peak values found in the early morning in all three groups. The daytime/overnight excretion ratios of sodium and water were normal in group 1 and low in group 2. These results indicate that diurnal changes in plasma ANP, PRA and plasma aldosterone are altered in diabetic subjects with normal and reversed diurnal BP rhythms, predominantly in the latter.
Aged↗
Partial DiGeorge syndrome at the age of thirty-four.
A 34-year-old man with partial DiGeorge syndrome suffered from seizures and mental retardation from the age of three years. He was diagnosed as having primary hypoparathyroidism by the Ellsworth-Howard test at the age of 22. He was also found to have a right aortic arch. Immunological studies revealed the presence of immature T cells (CD 38+, OKT 9+), although the subsets and function of his T cells were almost normal. The facts that the cardiovascular anomaly and immunodeficiency were mild and the hypoparathyroidism was well controlled, may account for his survival to this age.
Adult↗
Periosteal osteosarcoma and parosteal chondrosarcoma evaluated by double immunohistochemical staining. Report of 2 cases.
Differentiation of periosteal osteosarcoma and parosteal (periosteal) chondrosarcoma by conventional histology may be difficult. One case each of clinically and histologically proven periosteal osteosarcoma and parosteal chondrosarcoma were evaluated by a double-immunohistochemical staining method using proliferating cell nuclear antigen (PCNA) and S-100 protein (S-100). Conventional histology showed proliferation of both osteoblastic and chondroblastic cells in the periosteal osteosarcoma, while there was a growth of only chondroblastic tumor cells in the parosteal chondrosarcoma. Immunohistochemical studies indicated that the nuclei of chondroblastic cells recognized by S-100 were PCNA-negative, while osteoblastic stromal cells were PCNA-positive in the periosteal osteosarcoma. In contrast, chondroblastic cells in the parosteal chondrosarcoma were both S-100- and PCNA-positive. Our findings suggest that periosteal osteosarcoma is characterized by the proliferation of osteoblastic stromal cells, whereas parosteal chondrosarcoma is characterized by the proliferation of chondroblastic cells. This method of double immunohistochemical staining, using PCNA and S-100, may be useful in differentiating these chondroblastic tumors.
Adolescent↗