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Biomedical subjects

S Eto

Publications and source records attributed to S Eto.

At least 19 recordsLinked to original sources

Chiral separation of barbiturates and hydantoins by reversed-phase high-performance liquid chromatography using a 25 or 50 mm short ODS cartridge column via beta-cyclodextrin inclusion complexes.

A high-performance liquid chromatographic method on a 25 or 50 mm short ODS cartridge column has been developed for the resolution of the enantiomers of some optically active barbiturates and hydantoins in human serum. beta-Cyclodextrin was used in the mobile phase. This method also seems to be an easy and effective way to test whether beta-cyclodextrin would be a useful chiral discriminator for a particular racemate.

Barbiturates

Inhibitory effects of endothelin-3 on vasopressin release from rat supraoptic nucleus in vitro.

Endothelin (ET) is thought to be involved in the central regulation of body water metabolism. A recent perfusion study of rat hypothalamus showed that ET has a direct stimulatory action on arginine-vasopressin (AVP) release. This study was undertaken to investigate whether ET acts directly on AVP release for supraoptic nucleus (SON) neurons, using brain slices containing only the SON. It was demonstrated that ET inhibited the AVP release dose-dependently from 10(-11) M to 10(-6) M. No difference of the effects of ET-1 and ET-3 on AVP release was observed. These results suggest that ET directly inhibits SON neurons through the ETB receptor.

Animals

Interactions between recombinant human erythropoietin and serum factor(s) on murine megakaryocyte colony formation.

We investigated the interactions between human erythropoietin (hEpo) and serum factor(s) on murine megakaryocyte (MK) colony formation. Serum-free cultures supported the growth of a large number of murine MK colonies in the presence of murine interleukin-3 (mIL-3). The addition of fetal calf serum (FCS) to mIL-3-containing cultures resulted in only a minimal increase in the number of murine MK colonies. In contrast, hEpo alone had no murine MK colony-stimulating activities in serum-free cultures. hEpo required the presence of FCS, murine serum, or human serum in cultures to promote murine MK colony growth and synergized with these sera to stimulate murine MK colony formation. Furthermore, sera from patients with aplastic anemia showed higher synergistic activities with hEpo than sera from hematologically normal persons (normal human serum). When normal human serum was fractionated by gel-filtration chromatography, two peaks with the synergistic activity were observed in the eluent. However, serum did not show any synergistic effects with hEpo on the growth of murine GM colonies or murine colony-forming unit-erythroid-derived colonies. Although human serum synergized with hEpo to stimulate murine MK colony formation, human cytokines such as IL-3, IL-4, IL-6, granulocyte-macrophage colony-stimulating factor (GM-CSF) and granulocyte-CSF (G-CSF) failed to induce murine MK colony formation in Epo-containing cultures. In cultures containing human IL-1 alpha + human IL-6 + hEpo as well as in cultures containing hEpo, human IL-3 and human GM-CSF failed to show stimulatory effects on murine MK colony formation. Moreover, the synergistic activity of human serum with hEpo could not be neutralized by antibodies such as antihuman IL-1 alpha, antihuman IL-3, antihuman IL-4, antihuman IL-6, antihuman G-CSF, and antihuman GM-CSF. Our data show that serum contains a growth factor(s) that synergizes with Epo to stimulate the proliferation and differentiation of MK precursors, and strongly suggest that this factor(s) is an unique growth factor(s) that is distinct from IL-1 alpha, IL-3, IL-4, IL-6, G-CSF, and GM-CSF.

Anemia, Aplastic

Dihydrotestosterone accumulation in genital skin fibroblasts derived from elderly men with prostatic hyperplasia.

The conversion of testosterone to dihydrotestosterone (DHT) by 5 alpha-reductase and the interconversion between DHT and 5 alpha-Androstane-3 alpha,17 beta-diol (3 alpha-diol) by 3 alpha-hydroxysteroid oxidoreductase (3 alpha-HSOR) were studied in fibroblasts derived from the genital skin of 15 prepubertal boys (2-10 yr), 17 young men (20-40 yr), 13 elderly men (60-78 yr) without clinically evident prostatic pathology, and 17 elderly men (61-88 yr) with benign prostatic hyperplasia (BPH). Respective DHT formations from testosterone (5 alpha-reduction) and 3 alpha-diol (3 alpha-HSOR oxidation) were not different among genital skin fibroblasts of the 4 groups. However, DHT degradation to 3 alpha-diol (3 alpha-HSOR reduction) was significantly lower in fibroblasts from elderly men with BPH than in those from the prepubertal boys (P less than 0.01), the young men (P less than 0.01), and the elderly men without BPH (P less than 0.05). 3 beta-HSOR reduction in fibroblasts of the BPH group was significantly lower (P less than 0.05) than in those of the elderly men without BPH; however, it did not differ from values for the prepubertal boys and the young men. (3 alpha + 3 beta)-HSOR reduction was also significantly lower (P less than 0.05) in the BPH group than respective values of the three other groups. These results indicate that DHT accumulation may occur in genital skin fibroblasts from elderly men with BPH, resulting from a shift in the overall balance of androgen metabolism, which favors the net formation of DHT.

Aged

A kindred of multiple endocrine neoplasia type 2B.

We describe familial cases of multiple endocrine neoplasia (MEN) 2B: A 48-year-old man is the proband. He had pheochromocytoma, medullary thyroid carcinomas (MTCs), parathyroid hyperplasia, mucosal neuromas, eversion of eyelids and Marfanoid appearance, and then underwent adrenalectomy and total thyroidectomy. Family screening revealed that his two daughters (10 and 8 years old) had mucosal neuromas and increased serum calcitonin (CT). Both of them had MTCs but no pheochromocytoma, and their MTCs were surgically removed. The father and his children have been in favorable condition since the operations. Southern blot analysis with 33 polymorphic DNA probes was done in MTCs obtained from two daughters. An RBP3 (10q11.2) locus linked to a predisposing gene on chromosome 10 was uninformative in either patient because of constitutional homozygosity. Loss of heterozygosity at the MYCL1 locus on chromosome 1p32 was observed in MTC from the younger sister, but no loss of heterozygosity was recognized in other loci examined. Deletion of the 1p32 locus may play a role in the development of MEN 2B.

Adrenal Gland Neoplasms

Siblings of 21-hydroxylase deficiency (non-salt-losing) with aldosterone hypersecretion.

We describe siblings with the non-salt-losing form of 21-hydroxylase deficiency who had hypersecretion of aldosterone and plasma renin activity (PRA). Blood pressure and serum electrolytes in both cases were normal despite the aldosterone hypersecretion. Aldosterone secretion was elevated markedly with ACTH administration and with sodium deprivation and/or volume depletion during ACTH suppression by dexamethasone. With suppression by dexamethasone, aldosterone hypersecretion was decreased with lowering of the steroids proximal to the block in the biosynthetic pathway. However, urinary sodium excretion was decreased. These results suggest that the biosynthetic pathway for aldosterone production was preserved. Furthermore, aldosterone hypersecretion and high PRA may serve to compensate for the sodium loss which results in turn from the overproduction of the sodium-losing steroids, such as progesterone and 17 alpha-hydroxyprogesterone which are aldosterone antagonists.

Adolescent

Immunosuppressive factor produced by a B cell line derived from an adult T cell leukemia patient.

The immunosuppressive activity of culture supernatants from human T cell leukemia virus type I (HTLV-I)-infected cell lines was examined in vitro. Culture supernatants of both a HTLV-I-infected B cell line, IWS, established from an adult T cell leukemia (ATL) patient and a T cell line, MT-2, suppressed lymphocyte proliferative responses to stimulation with the mitogens phytohemagglutinin (PHA), concanavalin A (Con A), and pokeweed mitogen (PWM). The immunosuppressive factor was not cytotoxic for lymphocytes and did not inhibit the spontaneous growth of ATL cells. It inhibited interleukin-2 (IL-2) production by PHA-stimulated T cells and it arrested PHA-stimulated T cells at the G0/G1 phase of the cell cycle and inhibited entry into the S phase. Furthermore, the factor significantly inhibited the expression of CD3, CD4, and IL-2 receptor (IL-2R) alpha-chain (CD25) on PHA-stimulated T cells. These results suggest that the immunosuppressive factors produced by HTLV-I-infected cell lines might function in the regulation of normal lymphocyte proliferative responses, and that they could play some role in the induction of the immunodeficient condition observed in ATL patients.

Adult

[Clinical significance of rheumatoid factor--its complement activating property and isotype].

We investigated the relationship between complement-activating properties of rheumatoid factors (RF) and their isotypes. Active and inactive RA patients without extra-articular symptoms (EAS) and those with EAS were studied. Patients with SLE, liver cirrhosis (LC) and normal volunteers were served as controls. Isotype of RF was measured by ELISA and complement activation (CA) of RF was measured by hemolytic assay. The CA values were significantly higher in RA patients with EAS than those in RA patients without EAS and with other diseases. The IgG and IgM-RF values were significantly higher in active RA without EAS than in inactive RA. Positive correlations between IgM-RF values and CA values were observed in RA with or without EAS, SLE and LC. The Sephadex G-200 gel filtration analysis of sera revealed CA in only 19S IgM fraction. Additionally, we purified 19S IgM-RF from sera of RA, SLE and LC patients by affinity chromatography, and found 19S IgM-RF had CA. These data suggest that serum IgM-RF may play a critical role in the pathogenesis of RA, especially in RA with EAS.

Arthritis, Rheumatoid

[Urinary excretion of parathyroid hormone-related protein in patients with adult T-cell leukemia and other hematologic disorders].

Urinary excretion of parathyroid hormone-related protein (PTH-rP) was measured by radioimmunoassay in 25 patients with adult T-cell leukemia (ATL), in 68 patients with other hematologic disorders and in 13 asymptomatic individuals seropositive for human T-cell leukemia virus type I (HTLV-I). The mean levels of urinary PTH-rP in ATL patients with hypercalcemia (11.01 micrograms/g.Cr) were higher than in ATL patients with normocalcemia (5.16 micrograms/g.Cr). The mean levels in patients with acute type (8.84 micrograms/g.Cr), lymphoma type (4.18 micrograms/g.Cr) and crisis ATL (18.20 micrograms/g.Cr) were significantly higher than in urine of healthy controls. However, all asymptomatic carriers of HTLV-I and patients with chronic and smoldering ATL had normal urinary PTH-rP levels. In 7 patients with acute myelogenous leukemia, 1 patient with blastic crisis of chronic myelogenous leukemia and 3 patients with malignant lymphoma, the urinary levels of PTH-rP were above the normal range. Urinary levels of PTH-rP of the ATL patients with hypercalcemia correlated with the serum calcium levels. Urinary levels of PTH-rP of the all ATL correlated with serum lactic dehydrogenase level. These findings suggest that the measurement of urinary levels of PTH-rP is useful for evaluation of ATL and that some tumor cells of other hematologic diseases may produce PTH-rP.

Hematologic Diseases

[A case of dermatomyositis associated with thymic abnormalities].

A case of dermatomyositis (DM) associated with thymic cyst with lymphoid follicle formations has been reported. A 57-year-old man developed polyarthralgia, muscle weakness, heliotrope rash and Gottron's sign. Laboratory findings showed elevated values of creatine-phosphokinase, aldolase and transaminase. He was diagnosed as DM and was treated with prednisolone 50 mg/day. Muscle weakness was improved immediately, although rash persisted unchangeably. He was examined for coexistence of malignant tumor which had been reported frequently as associated with DM. Enlargement of thymus was found by computer tomography and then thymectomy was performed. In his thymus, lymphoid follicle formations, which are as often encountered in other autoimmune diseases, were found. So far, the beneficial effect of thymectomy on the improvement of immunological abnormalities not only in patients with myasthenia gravis but also in patients with other autoimmune diseases has been recognized. In this case, intractable rash in DM improved after thymectomy. Further study needs to clarify the relationships between DM and thymic abnormalities.

Dermatomyositis

Effect of hyperbaric oxygenation on macrophage function in mice.

Hyperbaric oxygenation (HBO) has an immunosuppressive effect. The possible mechanisms of this immunosuppressive effect were assessed by determining the production of interleukin-1 (IL-1), interleukin-6 (IL-6), and prostaglandin E2 (PGE2), as well as phagocytosis by splenic macrophages from HBO-treated mice. Although HBO treatment did not have any significant effect on IL-6 production and phagocytotic activity, a marked decrease in IL-1 production and a significant decrease in PGE2 production were observed. These results suggest that the reduction of IL-1 production may play an important role in the immunosuppressive effect of HBO.

Animals

Interleukin-4 blocks parathyroid hormone-related protein-induced hypercalcemia in vivo.

Interleukin (IL)-4 inhibits bone resorption. In the present study, the effect of IL-4 on hypercalcemia in nude mice under two experimental conditions was assessed. IL-4 inhibited plasma calcium elevation induced by parathyroid hormone-related protein (PTHrP) infusion. In hypercalcemic nude mice bearing PTHrP-producing tumors, IL-4 lowered plasma calcium levels to almost the normal range. These results indicate that IL-4 blocks PTHrP-induced hypercalcemia in vivo.

Animals

High-performance liquid chromatographic method for direct separation of 5-(p-hydroxyphenyl)-5-phenylhydantoin enantiomers using a chiral tris(4-methylbenzoate) column.

After simple purification of the incubation mixture of phenytoin in isolated rat hepatocytes, 5-(p-hydroxyphenyl)-5-phenylhydantoin (p-HPPH), which formed as a major metabolite, was readily resolved to each enantiomer by direct high-performance liquid chromatography on a cellulose tris(4-methylbenzoate) column, with a mobile phase of ethanol-water. It was also observed that the formation of S-(-)-p-HPPH was dominant, and the S/R ratio was 11.5.

Animals

A Waldenström's macroglobulin with anti-G3m(b1) antibody activity.

A human monoclonal macroglobulin (IgM, K) from a patient (KI) with Waldenström's macroglobulinemia was shown to have antibody activity against a human IgG (Gm) allotype. In hemagglutination tests, only one anti-D serum with G3m(b0b1) reacted with macroglobulin KI. Antiglobulin specificity of macroglobulin KI was determined to be an anti-G3m(b1) antibody by hemagglutination inhibition tests. Fab fragments from macroglobulin KI could react with human IgG3 protein possessing G3m(b1), but Fc fragments could not react. Gm phenotype in IgG isolated from serum KI was determined to be Gm(a,z,g,b0,s,t,u). This is the first report of a Waldenström's macroglobulin with antiglobulin specificity against a Gm allotype.

Aged

DHT formation and degradation in cultured human skin fibroblasts: DHT accumulation in the genital skin.

The conversion of testosterone to dihydrotestosterone (DHT) by 5 alpha-reductase and the interconversion between DHT and 5 alpha-androstane-3 alpha, 17 beta-diol (3 alpha-diol) by 3 alpha-hydroxy-steroid oxidoreductase (3 alpha-HSOR) were studied in fibroblasts derived from the genital skin of 22 males and 6 females, and from the nongenital skin of 19 males and 9 females with normal gonadal function. The formation of DHT from testosterone (5 alpha-reduction) was significantly greater in fibroblasts from genital skin than in those from nongenital skin in both males (2.15 +/- 1.43 vs 0.81 +/- 0.46 pmol/mg protein/h, mean +/- SD, P less than 0.001) and females (2.52 +/- 1.99 vs 0.69 +/- 0.18, P less than 0.01). Furthermore, DHT formation from 3 alpha-diol (3 alpha-HSOR oxidation) was also significantly greater in genital skin fibroblasts than in nongenital skin fibroblasts of males (5.47 +/- 3.37 vs 2.52 +/- 1.74 pmol/mg protein/h, P less than 0.01). However, the degradation of DHT to 3 alpha- and/or 3 beta-diol (3 alpha- and/or 3 beta-HSOR reductions) was not different between genital and nongenital skin fibroblasts of either males or females. Respective ratios of DHT formation to DHT degradation (5 alpha-reduction/3 alpha-HSOR reduction, 3 alpha-HSOR oxidation/3 alpha-HSOR reduction) were also significantly greater (P less than 0.002) in genital skin fibroblasts than in nongenital skin fibroblasts of males. On the other hand, both DHT formation and degradation were not different between male and female genital skin fibroblasts. These results suggest that the increased production of DHT in genital compared to nongenital skin results from increased 5 alpha-reduction and 3 alpha-HSOR oxidation.

3-Oxo-5-alpha-Steroid 4-Dehydrogenase