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Biomedical subjects

Y Iwai

Publications and source records attributed to Y Iwai.

At least 163 records · Page 9Linked to original sources
PubMed1990

Langerhans cells in odontogenic tumours and cysts as detected by S-100 protein immunohistochemistry.

Immunohistochemical demonstration of S-100 protein in Langerhans cells (LCs) was made in odontogenic epithelial tumours (71 cases), radicular cysts (40 cases), follicular cysts (28 cases), odontogenic keratocysts (11 cases), primordial cysts (7 cases) and fissual cysts (6 cases). With the use of polyclonal antiserum against S-100 protein, positive LCs, dendrical or irregular in shape were found in tumour or cystic epithelia, and sometimes in stromal connective tissue. Incidence of positive S-100 staining LCs was 11 cases out of 61 ameloblastomas, 22 cases out of 40 radicular cysts, 3 cases of 28 follicular cysts, and other lesions in both odontogenic tumours and cystic diseases lacked LCs. The cases with S-100 protein positive LCs were usually accompanied with a high degree of inflammatory infiltration in their lesions; on the contrary, the negative cases also generally lacked inflammatory responses.

Humans↗
PubMed1990

[A case of ectopic large pituitary adenoma].

Ectopic pituitary adenomas are very rare and only 17 cases have been reported. In this paper we present a case of large pituitary adenoma originating in the suprasellar region. A 26-year-old man was admitted to our clinic with a chief complaint of headaches. Neurological examination revealed slight disorientation and bilateral choked disk. Hormonal study revealed that the serum prolactin level was 3300ng/ml and serum growth hormone level was 29.5ng/ml. Computed tomography showed a large mass in the suprasellar region extending upward to the third ventricle and backward to the pons. T1-weighted MR imaging revealed that the intensity of the mass was the same as that of the cerebral cortex and the pituitary gland was showing high intensity in the pituitary fossa. The tumor was radically removed via the transpetrosal transtentorial approach. Histologically, the tumor was a prolactin-growth hormones producing pituitary adenoma. The literature was reviewed and the origin of the tumor was discussed.

Adenoma, Chromophobe↗
PubMed1989

Regulation of Fc gamma receptor expression and phagocytosis of a human monoblast cell line U937. Participation of cAMP and protein kinase C in the effects of IFN-gamma and phorbol ester.

We investigated the positive and negative effects of IFN-gamma, PMA, dibutyryl cAMP (Bt2cAMP), dexamethasone and transforming growth factor-beta (TGF-beta) on Fc gamma R subtype expression and phagocytosis of a human monoblast cell line, U937. IFN-gamma increased and Bt2cAMP decreased Fc gamma RI expression determined by a mAb 32.2, whereas PMA and Bt2cAMP increased Fc gamma RII expression determined by a mAb IV-3. Phagocytosis was measured microscopically by counting ingested aggregated human IgG- or BSA-treated ox E (Eo'-IgG or Eo'-BSA). IFN-gamma increased the phagocytosis of Eo'-IgG but not that of Eo'-BSA, and PMA increased the phagocytosis of both Eo'-IgG and Eo'-BSA. Bt2cAMP decreased both basal and IFN-gamma- and PMA-augmented phagocytosis of U937 cells. Dexamethasone also inhibited both basal and IFN-gamma-augmented Fc gamma RI expression and PMA-augmented Fc gamma RII expression and phagocytosis, but did not affect IFN-gamma-augmented phagocytosis of Eo'-IgG. The augmentation of phagocytosis of Eo'-IgG by IFN-gamma thus seems to be due mainly to the increased internalizing process rather than to increased Fc gamma RI expression. TGF-beta slightly decreased Fc gamma R expression. In a study of the participation of protein kinase C (PK-C), it was found that H-7, a PK-C inhibitor, did not inhibit either IFN-gamma- or PMA-enhanced Fc gamma RI and Fc gamma RII expression, respectively, and 1-oleoyl-2-acetylglycerol and N-(6-phenylhexyl)-5-chloro-1-naphthalenesulfonamide, both PK-C activators, did not show any apparent increase in Fc gamma R expression and phagocytosis. These results show that Fc gamma RI and Fc gamma RII expression on U937 cells is regulated by different mechanisms and that IFN-gamma and PMA play their roles in Fc gamma R expression and phagocytosis by different pathways. It is possible that cAMP but not PK-C plays an important role in the regulation of Fc gamma R expression and phagocytosis.

Antigens, Differentiation↗
PubMed1989

Hepatic blood flow and drug metabolism in glycerol-rechallenged rats.

To analyze the hepatic blood flow and drug metabolism during glycerol-induced acute renal failure, 24 male Wistar rats were randomly divided into three groups: Group I received an intra-muscular injection of 1 ml/100 g body weight 50% glycerol, group II a second injection on day 14 and group III a second injection on day 42 after the first injection respectively. The inulin clearance, the aminopyrine N-demethylase activity, the NADPH-cytochrome P-450 activity and the cardiac output and blood flow to the organs were measured before and after glycerol injection. The total hepatic and renal blood flow decreased less significantly in group II compared to group I and III. Various P 450 activities were kept on a high level only in group II. This observation indicates that the maintenance not only of renal but also of hepatic blood flow plays an important role in preventing the development of glycerol-induced acute renal failure. The mechanism may be the induction of various P 450 activities resulting in an increased hepatic clearance of nephrotoxic substances.

Acute Kidney Injury↗
PubMed1989

Regulation of Fc epsilon receptor 2 (CD23) expression on a human eosinophilic cell line EoL3 and a human monocytic cell line U937 by transforming growth factor beta.

Regulation of low-affinity receptors for IgE (Fc epsilon R2/CD23) on a human eosinophilic cell line EoL3 and a human monocytic cell line U937 was studied using an anti-Fc,R2/CD23 monoclonal antibody H107 by flow cytometry. While platelet-activating factor, interleukin 4, and interferon gamma significantly augmented Fc epsilon R2/CD23 expression on both cell lines, transforming growth factor beta (TGF beta) inhibited both the basal level of Fc epsilon R2/CD23 expression and the enhanced Fc epsilon R2/CD23 expression induced by these reagents in dose- and time-dependent manners. However, TGF beta did not significantly suppress the high basal level of Fc epsilon R2/CD23 expression on RPMI 8866 cells. These results suggest that Fc epsilon R2/CD23 expression on EoL3 and U937 cells is regulated by various cytokines and growth factors, and that TGF beta plays an important regulatory role in IgE-mediated immune responses.

Antigens, Differentiation, B-Lymphocyte↗
PubMed1989

Soluble low affinity Fc receptors for IgE in the serum of allergic and nonallergic children.

IgE-binding factors are thought to have regulatory activity in in vitro IgE synthesis. To obtain evidence of the participation of IgE-binding factors in in vivo IgE synthesis, the serum level of low affinity Fc receptors for IgE (sFc epsilon RII) (IgE-BFs) was examined in 41 nonallergic children and in 37 allergic children whose serum IgE levels were significantly higher than those of nonallergic children. The serum level of sFc epsilon RII showed a marked age-dependent variation. It was highest in infants and then decreased gradually with age. The serum level of sFc epsilon RII in allergic children was significantly higher than that of nonallergic children in early childhood (1128.0 +/- 323.8 vs 777.3 +/- 227.0 pg/ml, p less than 0.01 in infants (less than 1 y) and 851.8 +/- 270.0 vs 579.4 +/- 197.1 pg/ml, p less than 0.05 in children aged 1-2 y) but not in older children (3-15 y). Three allergic infants (less than 1 y) with serum sFc epsilon RII levels higher than the mean + 1 SD (1451.8 pg/ml) of all allergic infants (less than 1 y) had serum IgE levels (geometric mean 125.9 IU/ml) significantly higher than the other seven allergic infants (less than 1 y) (geometric mean 5.6 IU/ml, p less than 0.05). A close positive correlation between the serum level of sFc epsilon RII and the absolute number of Fc epsilon RII(+) peripheral blood lymphocytes was observed (Spearman's rank correlation coefficient = 0.79, p less than 0.001 in 27 allergic and Spearman's rank correlation coefficient = 0.72, p less than 0.001 in 19 nonallergic children). In conclusion, serum sFc epsilon RII may be derived mainly from Fc epsilon RII(+) lymphocytes, and may have relationship to the increased production of IgE in early childhood (0-2 y).

Adolescent↗
PubMed1989

[Spontaneous spinal epidural hematoma diagnosed by MRI: a case report].

Appropriate diagnostic procedure for spinal epidural hematomas has not been established yet. The authors reported a case of spontaneous epidural hematomas at the thoracic level, in which correct diagnosis was made with MRI and good results were obtained by surgery. A 63-year-old female experienced a severe back pain which appeared suddenly during a walk and was followed by motor weakness in both legs deteriorating quickly to paraplegia. The patient had no history of hypertension, trauma or bleeding tendency. The laboratory data were normal. On admission, neurological examination revealed flaccid paraplegia, total sensory loss below the level of Th 6 and urinary and fecal incontinence. Myelograms showed incomplete block at the Th 6 level and postmyelographic CT scan showed an isodense mass, which was suspected to be an epidural tumor located behind the spinal cord. Emergent MRI confirmed an epidural hematoma as a high intensity area extending from Th 3 through Th 11. Sixty-five hours after onset, laminectomy of Th 4 through Th 11 and the evacuation of epidural hematoma were performed without identification of the origin of the bleeding. Neither vascular malformation nor tumor was recognized during operation. Neither was it noticed on histological examination. The patient made favorable progress after the surgery. During the first two weeks in the postoperative period, she regained muscle strength enough to do standing exercise, and satisfactory improvement was made in sensory function including urination and defecation. We emphasize that MRI is indispensable to make a differential diagnosis of thoracic lesions. In the reported case, a correct diagnosis was made with MRI, and an extremely good result was obtained by an emergency operation.

Female↗
PubMed1989

[A case of bowenoid papulosis of the penis].

A 44-year-old man, who was seen for further examination of macroscopic hematuria, was found to have black eruptions on the penis and the scrotum. These eruptions appeared benign clinically, but on histological examination they showed the features of Bowen's disease. These eruptions were diagnosed as Bowenoid papulosis and were successfully treated with 5-FU cream. Twenty five cases of Bowenoid papulosis observed in men have been reported in Japan. Although Bowenoid papulosis is characterized by the histopathologic conditions of Bowen's disease, the lesions of Bowenoid papulosis differ clinically from those of Bowen's disease in several respects: onset at earlier average age, multiplicity of lesion, lack of associated symptoms, smaller size of the lesion, clinical morphologic features and possible spontaneous regression.

Adult↗
PubMed1988

A gigantic neurilemoma originating in the pterygopalatine fossa. Case report.

A 7-year-old girl complained of gradually progressing right nasal obstruction, right exophthalmos, and deterioration of right visual acuity. Computed tomography scanning showed a large mass originating in the pterygopalatine fossa and extending to both the pterygomaxillary fossa and the orbital apex on the right side. The tumor was totally removed via the orbitozygomatic infratemporal approach. The literature is reviewed and the operative approach is discussed.

Cerebral Angiography↗
PubMed1988

Postnatal changes in plasma burst-promoting activity (BPA) levels in preterm infants.

Two-stage cell culture assays were used to determine burst-promoting activity (BPA) levels in the plasma of untransfused premature infants during the early anaemic period. The plasma BPA levels decreased during the early phase of the postnatal fall in haemoglobin and the mean plasma BPA levels at 2 and 4 weeks of age were significantly lower (24 +/- 9% and 20 +/- 14%) than those of normal adults (53 +/- 17%). After 8 weeks of age, plasma BPA levels increased markedly in correlation with the recovery of erythropoiesis. Inhibitors of erythroid colony growth were not significantly elevated in the plasma of premature infants. These results suggest that BPA may act as a regulator of erythropoiesis in preterm infants along with erythropoietin.

Adult↗
PubMed1988

IgE receptor-bearing lymphocytes in allergic and nonallergic children.

Using a monoclonal anti-human IgE receptor (Fc epsilon R) antibody, the percentage of Fc epsilon R(+) cells among peripheral blood lymphocytes in children with or without allergic disorders was determined. The percentage of Fc epsilon R(+) cells in 63 nonallergic children was 4.3 +/- 1.5%, which did not vary with age and was equal to that of adults (4.2 +/- 1.2%). Allergic younger children (0-2 yr) showed a significantly higher percentage of Fc epsilon R(+) cells (7.7 +/- 3.0%) than nonallergic younger children (0-2 yr) (4.0 +/- 1.3%, p less than 0.001). Similarly, in allergic younger children, serum IgE levels (geometric mean = 58.9 IU/ml) were also significantly higher than those of nonallergic younger children (geometric mean = 2.0 IU/ml) (p less than 0.01). A positive correlation between the percentages of Fc epsilon R(+) cells and serum IgE levels was observed (Spearman rank = 0.88, p less than 0.01] in eight allergic younger children (0-2 yr) with serum IgE levels higher than 100 IU/ml. The increase in the percentage of Fc epsilon R(+) cells in allergic younger children (0-2 yr) was not a secondary phenomenon caused by serum IgE because serum IgE levels in these children were much lower than the concentration at which IgE enhance Fc epsilon R expression on lymphocytes. In conclusion, Fc epsilon R(+) lymphocytes may play a regulatory role in IgE synthesis in allergic younger children (0-2 yr).

Adolescent↗
PubMed1988

Atpenins, new antifungal antibiotics produced by Penicillium sp. Production, isolation, physico-chemical and biological properties.

Penicillium sp. FO-125, a soil isolate, was found to produce a new antifungal antibiotic complex named atpenin. Three components A4, A5 and B were isolated from the fermentation broth of the producing strain by solvent extraction, silica gel column chromatography and HPLC. The molecular formula of atpenins A4, A5 and B were determined to be C15H22NO5Cl, C15H21NO5Cl2 and C15H23NO5, respectively, on the basis of high resolution electron impact mass spectrometry and elemental analysis. They are active against filamentous fungi, especially, Trichophyton sp.

Antifungal Agents↗
PubMed1988

Screening for new antitrichomonal substances of microbial origin and antitrichomonal activity of trichostatin A.

In vitro and in vivo screening methods for new antitrichomonal substances were established. Primary screening is based on in vitro antitrichomonal activities of culture broths of actinomycetes isolated from soil. With secondary screening, after crude materials obtained from the cultured broths were administered orally to mice, excretion of antitrichomonal activity into urine was examined. Tertiary screening was done by examining therapeutic activity for experimental trichomoniasis in mice with Trichomonas foetus. Using the screening systems, a new antibiotic (setamycin)-producing strain was picked out among about six thousands soil isolates, and the therapeutic efficacy of KM-3851, which was identified as trichostatin A, was found. It was active against T. foetus both in vitro and in vivo.

Animals↗
PubMed1988

Low burst-promoting activity (BPA) production by cord mononuclear cells is due to functional immaturity of monocytes.

Cord blood mononuclear cells produced lower burst-promoting activity (BPA) than adult peripheral blood mononuclear cells when stimulated with phytohemagglutinin (PHA). In order to examine the cellular basis of the low production of BPA by PHA-stimulated cord blood mononuclear cells in the context of the functional immaturity of T cells or monocytes, we studied BPA production by T cells or monocytes from cord blood and adult peripheral blood. Cord T cells produced as much BPA as adult T cells. Monocytes themselves did not produce significant BPA at the concentration used in this experiment (1 x 10(5)/ml). BPA production by adult T cells was significantly enhanced by the presence of autologous monocytes. BPA production by cord T cells was also enhanced by the presence of adult monocytes but not by that of cord monocytes. Cord monocytes did not enhance BPA production by adult T cells either. These results indicate that cord monocytes are primarily responsible for the low BPA production by PHA-stimulated cord mononuclear cells.

Erythropoiesis↗