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Biomedical subjects

S Shimada

Publications and source records attributed to S Shimada.

At least 307 records · Page 17Linked to original sources
PubMed1990

Characterization of cultured neurofibroma cells derived from von Recklinghausen's disease.

We have examined the cytoplasmic distribution of actin and fibronectin in cultured neurofibroma cells (NF cells) derived from a patient with von Recklinghausen's disease by using phase contrast and indirect immunofluorescence microscopy. NF cells were larger in size and more dendritic in shape compared to normal human dermal fibroblasts. NF cells also showed abundant granular staining of actin and a decrease in the linear staining pattern of fibronectin. Furthermore, employing a colony-formation assay on the top of an agar-gel in the presence of fibroblast growth factor (FGF), normal fibroblasts showed a significant number of colonies, whereas NF cells did not demonstrate colony formation even after addition of FGF. These findings suggests that NF cells from patients with von Recklinghausen's disease may have different characteristics when compared with normal fibroblasts, and that NF cells are similar to transformed cells with regard to their actin and fibronectin distribution.

Actins↗
PubMed1990

Characterization of a porcine CD1-specific mAb that distinguishes CD4/CD8 double-positive thymic from peripheral T lymphocytes.

Porcine peripheral T-cells bear CD4 and CD8 cell surface antigens that distinguish helper from cytotoxic T-cells. In distinction from what has been found in other species, a large percentage of peripheral T-cells simultaneously express both CD4 and CD8. Monoclonal antibody 76-7-4 was found to stain all cortical and 7 +/- 3% of medullary thymocytes, Ia+ epidermal cells (i.e. Langerhans cells), no peripheral T-cells and 50% of peripheral B-cells. The antigen detected appears analogous to human CD1. All cortical thymocytes were also stained with CD4 and CD8 mAb. Since 76-7-4 did not stain peripheral T-cells, we conclude that CD4/CD8 dual-expressing peripheral T-cells are not simply immature thymic emigrants.

Animals↗
PubMed1990

Eustachian tube function and mastoid pneumatization.

We investigated the relationship between the Eustachian tube's ventilatory function and the pneumatization of mastoid air cells. In 65 adults (66 ears) with chronic otitis media (COM), ventilatory Eustachian tubal function was evaluated by the inflation-deflation test, while the area of mastoid air cells was measured by the rectangular method on X-ray film. Group I represents good function in both the inflation and deflation tests. Group II represents good function in the inflation test but poor function in the deflation test. Group III represents a poorly functioning Eustachian tube in both tests. The opening pressure in Group III was statistically higher than in Group I and Group II. The area of mastoid air cells in Group I was statistically larger than in Group III. There was no correlation between opening pressure and area of mastoid air cells in COM. Postoperative failure of the tympanic membrane was frequently found in Group III. We discuss the tubal function and pneumatization of mastoid air cells.

Adult↗
PubMed1990

[T cell receptor gamma delta expression of Thy-1+ dendritic epidermal cells--an update].

Thy-1+ dendritic epidermal cells (Thy-1+DEC) are present in the murine epidermis. They are morphologically dendritic and express Thy-1, CD3 and asialoGM1, but not CD4 or CD8. T cell receptor (TCR) of Thy-1+DEC is TCR gamma delta. Allison et al and Tonegawa et al recently found that TCR of Thy-1+DEC is V gamma 5 J gamma C gamma -V delta 1D2J2C delta and has no junctional diversity. This TCR gamma delta of Thy-1+DEC is identical to TCR expressed on the earliest fetal thymocytes. It is distinct from that of other epithelial associated lymphocytes or other thymocytes. The ligand of Thy-1+DEC is not known, although TCR gamma delta of adult type could recognize allogenic major histocompatibility complex(MHC) class I or class II and mycobacterium antigen, especially heat shock protein. The TCR of Thy-1+DEC may not be the homing receptor to epidermis. The further studies are needed to elucidate the ligands or functions of Thy-1+DEC.

Animals↗
PubMed1990

[The use of Pugh score to evaluate the prognostic and therapeutic influence of drinking in patients with decompensated liver cirrhosis].

The aim of this study is to evaluate the clinical usefulness of Pugh score in the prognosis of the patients (pts.) with decompensated liver cirrhosis (DLC). To determine the influence of heavy drinking with respect to the prognosis of DLC patients, 128 cases of DLC were divided into two groups including the 31 heavy drinker group (Group A) and 97 non-alcoholic group (Group B). At the time of admission, the both groups showed similar Pugh score. However, after initial two hospitalized weeks, Group A started to show significantly lower points of Pugh score than that of in Group B. Fifteen pts. (48%) in Group A and 55 pts. (57%) in Group B had greater than 9 in Pugh score at the time of admission. In Group A, 10 of 15 pts. declined the scores after initial two weeks and 9 of them lived more than one year after admission. In contrast, none of those 55 pts. in Group B declined their Pugh score after admission and 45 of them died within one year. It was concluded that Pugh score was extremely useful to evaluate the prognosis of DLC pts., and DLC pts. who had greater than 9 Pugh score were seemed to be critical. It was suggested that DLC pts. due to heavy drinking tend to improve Pugh score comparing to no alcoholic DLC pts.

Adult↗
PubMed1989

Effects of stimulating the dorsal raphe nucleus of the rat on neuronal activity in the dorsal lateral geniculate nucleus.

The effect of stimulating the dorsal raphe nucleus (DRN) on the activity of single relay neurons in the dorsal lateral geniculate nucleus (LGNd) was studied in rats anesthetized with urethane. The position of stimulating electrodes was confirmed on histological sections processed with NADPH-diaphorase histochemistry which could delineate the DRN clearly. During repetitive stimulation of the DRN at 200 Hz for several to 10 seconds no consistent change in firing was observed, but between several and several tens of seconds after the cessation of stimulation spontaneous firing of LGNd neurons was suppressed. In many cases the suppression proceeded concomitantly with augmentation of slow waves in the cortical EEG. The suppression was mimicked by ionophoresis of serotonin, and antagonized by a serotonergic antagonist, methysergide. In addition, in animals in which DRN stimulation became ineffective after it was evoked many times, the suppression could be restored by intraperitoneal administration of a serotonin precursor, 5-hydroxytryptophan. Compilation of peristimulus time histograms revealed that a brief DRN stimulation (5 shocks at 1000 Hz) could also elicit the suppression lasting from 60 to 100 ms or longer after the shocks. These results suggest that serotonin released from terminals of DRN neurons exerts long-latency and long-lasting inhibition of LGNd relay neurons. Along with brainstem noradrenergic and cholinergic systems, the serotonergic projection from the DRN acts to control excitation levels of the forebrain.

5-Hydroxytryptophan↗
PubMed1989

The coexistence of substance P- and glutamic acid decarboxylase-like immunoreactivity in entopeduncular neurons of the rat.

The coexistence of substance P- and glutamic acid decarboxylase-like immunoreactivity in cell bodies was investigated in the entopeduncular neurons of the rat by the double-immunofluorescence method using species-specific antibodies. Over half of the substance P-like immunoreactive cells were GABAergic. Double-labeled neurons were generally seen in the rostral to the middle region of the entopeduncular nucleus. Since the rostral portion of the entopeduncular nucleus mainly projects to the lateral habenular nucleus, it is suggested that double-labeled neurons in the entopeduncular nucleus largely project to the lateral habenular nucleus which is involved in the limbic system.

Animals↗
PubMed1989

Light and electron microscopic studies of calcitonin gene-related peptide-like immunoreactive terminals in the central nucleus of the amygdala and the bed nucleus of the stria terminalis of the rat.

Light and electron microscopic analysis of calcitonin gene-related peptide (CGRP)-like immunoreactive (LI) terminals in the bed nucleus of the stria terminalis (BST) and the central nucleus of the amygdala (Ce) was carried out using the peroxidase-antiperoxidase method. CGRP-LI fibers were densely distributed in the dorsal subdivision of the lateral BST (BSTL) and the lateral and lateral capsular subdivisions of the Ce, where the CGRP-LI terminals formed symmetrical and asymmetrical axo-dendritic, and symmetrical axosomatic synapses. One of the most characteristic features of the CGRP-LI terminals was the presence of large, long boutons, each of which surrounded a cell soma and made many synaptic contacts. These findings suggest that CGRP exerts a significant influence on neurons in the BSTL and Ce.

Amygdala↗
PubMed1989

Quantitative electron microscopic study on grades of atypia in adenomas of the human large bowel.

Clarification of the ultrastructural features of the three different grades of histologic atypia of adenomas (i.e., mild, moderate, and severe atypia) with reference to carcinoma of the human colon and rectum was undertaken using electron microscopic quantitative analysis. Ten normal epithelia, 36 adenomas (14 with mild atypia, 13 with moderate atypia, and 9 with severe atypia) and 14 carcinomas (well-differentiated adenocarcinoma) were examined with light and electron microscopes. Although it has been generally accepted that malignant transformation of an adenoma gradually proceeds with increasing atypia, using light microscopy, ultrastructural quantitative analysis clearly revealed that fine features of individual atypia did not correspond with histologic grades of atypia. Ultrastructural changes occurred abruptly in moderate atypia and showed similar cellular characteristics to carcinoma cells. Mild atypia was almost similar in appearance to normal epithelial cells. Striking changes in the moderate atypic cells were plane apposition of the cell membrane, decrease of the desmosomes, and increase of the lysosomes. These atypical cells were assumed to play a significant role in the adenoma-carcinoma sequence. Therefore, radical surgical therapy would be required for moderate atypic adenoma of the large bowel that is difficult to remove endoscopically.

Adenocarcinoma↗
PubMed1989

In situ hybridization analysis of the somatostatin-containing neuron system in developing cerebellum of rats.

We used in situ hybridization histochemistry to examine the postnatal development of the somatostatin (SRIF) synthesizing system in the cerebellum of rats. There are numerous hybridizing neurons from 1 to 9 days after birth. These occur throughout the cerebellum including the developing medulla and cortex except in the external granular cell layer. The lateral cerebellar nucleus also contains SRIF gene-containing cells. The intensity of the signals for SRIF mRNA in the cerebellum decreases with age. There is a drastic decrease in SRIF mRNA in the lateral cerebellar nucleus. SRIF cells cannot be detected in the lateral cerebellar nucleus of adult rats, whereas a small, yet significant number of SRIF cells are scattered in the cerebellar medulla. However, the cerebellum of adult rats still contains a significant number of labeled cells in the granular cell layer, although the intensity for SRIF mRNA decreases from 14 days after birth to adulthood. SRIF gene-expressing cells in the cerebellar cortex are located primarily in the granular cell layer and appear to correspond to Golgi cells judging from their characteristic features. These results are consistent with our previous immunohistochemical study on the decrease of SRIF immunoreactivity in the cerebellum of adult rats. These findings, together with a recent study of transient SRIF receptor-expressing cells in the developing cerebellum suggest that SRIF acts during cerebellar development.

Aging↗
PubMed1989

Coexistence of peptides (corticotropin releasing factor/neurotensin and substance P/somatostatin) in the bed nucleus of the stria terminalis and central amygdaloid nucleus of the rat.

Coexistence of corticotropin releasing factor and neurotensin and also of substance P and somatostatin was demonstrated in the lateral bed nucleus of the stria terminalis and the central amygdaloid nucleus of the rat, by means of a light microscopic mirror method or immunofluorescent double staining. Using the former technique, a major proportion of corticotropin releasing factor-like immunoreactive cells were found to display neurotensin-like immunoreactivity in the dorsal subdivision of the lateral bed nucleus of the stria terminalis and the lateral subdivision of the central amygdaloid nucleus. On the other hand, the immunofluorescent method showed that a significant number of neurons with both substance P- and somatostatin-like immunoreactivity were located in the ventral subdivision of the lateral bed nucleus of the stria terminalis and the medial subdivision of the central amygdaloid nucleus. Distribution patterns of such co-localized peptides may indicate that there are morphological and biochemical similarities between the dorsal subdivision of the lateral bed nucleus of the stria terminalis and the lateral subdivision of the central amygdaloid nucleus, as well as between the ventral subdivision of the lateral bed nucleus of the stria terminalis and the medial subdivision of the central amygdaloid nucleus. Previous studies have demonstrated that peptide-containing neurons in the lateral bed nucleus of the stria terminalis and central amygdaloid nucleus, such as corticotropin releasing factor-, neurotensin-, substance P- and somatostatin-like immunoreactive cells, project to the lower brainstem. The results of the present study suggest that corticotropin releasing factor/neurotensin and substance P/somatostatin neurons may be part of the lateral bed nucleus of the stria terminalis/central amygdaloid nucleus-lower brainstem pathways.

Amygdala↗
PubMed1989

A light and electron microscopic study of calcitonin gene-related peptide in the rat caudate putamen.

Calcitonin gene-related peptide (CGRP)-like immunoreactive (CGRP-IR) structures have been studied in the rat caudate putamen using avidin-biotin peroxidase immunohistochemistry. Immunoreactivity was found in the axons of this nucleus but not in the perikarya. CGRP-IR fibers were most densely concentrated along the ventral border and in the caudal portion of the rat caudate putamen. CGRP-IR fibers were sparsely distributed throughout the rest of this nucleus. Almost all immunoreactive boutons which contained small clear vesicles had formed asymmetrical synapses. Postsynaptic targets included dendritic spines and shafts. Asymmetrical synapses in the caudate putamen are supposed to be extrinsic in origin. These observations, together with the results of other investigations, suggest that CGRP-IR boutons form synapses with spiny striatal neurons, which, most likely, are medium-sized spiny projecting neurons. Moreover, evidence indicates that these boutons are of extrinsic origin.

Animals↗
PubMed1989

In situ infiltration of natural killer-like cells induced by intradermal injection of the nucleic acid fraction from BCG.

Intradermal injection of MY-1, a nucleic acid fraction extracted from Mycobacterium bovis strain BCG, induced in situ infiltration of mononuclear cells, most of which were asialo GM1 (GA1)-positive as determined by immunofluorescence microscopy. The infiltration occurred with as little as 1 microgram of MY-1 and lasted for a week. Double immunofluorescence microscopy revealed that the infiltrating GA1-positive cells were all positive for Ly-5, and partially positive for Thy-1.2, but negative for Mac-1, Ia, mu-chain, Lyt-1, Lyt-2, L3T4, and Fc receptor II. They contained neither peroxidase nor nonspecific esterase. The infiltrating cells thus markedly resembled natural killer (NK) cells in their cytochemical characteristics and surface markers. DNase and RNase destroyed the GA1-positive cell-inducing activity of MY-1. These results indicate that the nucleic acid components of MY-1 are responsible for this effect.

Animals↗
PubMed1989

Automated exchange transfusion and exchange rate.

An automated blood exchange transfusion (BET) with a two-site technique has been devised by Goldmann et al and by us, using an infusion pump. With this method, we successfully performed exchange transfusions 189 times in the past four years on 110 infants with birth weights ranging from 530 g to 4,000 g. The exchange rate by the automated method was compared with the rate by Diamond's method. Serum bilirubin (SB) levels before and after BET and the maximal SB rebound within 24 hours after BET were: 21.6 +/- 2.4, 11.5 +/- 2.2, and 15.0 +/- 1.5 mg/dl in the automated method, and 22.0 +/- 2.9, 11.2 +/- 2.5, and 17.7 +/- 3.2 mg/dl in Diamond's method, respectively. The result showed that the maximal rebound of the SB level within 24 hours after BET was significantly lower in the automated method than in Diamond's method (p less than 0.01), though SB levels before and after BET were not significantly different between the two methods. The exchange rate was also measured by means of staining the fetal red cells (F cells) both in the automated method and in Diamond's method, and comparing them. The exchange rate of F cells in Diamond's method went down along the theoretical exchange curve proposed by Diamond, while the rate in the automated method was significantly better than in Diamond's, especially in the early stage of BET (p less than 0.01). We believe that the use of this automated method may give better results than Diamond's method in the rate of exchange, because this method is performed with a two-site technique using a peripheral artery and vein.

Bilirubin↗
PubMed1989

In vivo distribution of human milk leucocytes after ingestion by newborn baboons.

The in vivo distribution of enterally administered human milk leucocytes labelled with indium hydroxyquinoline (111In) was studied in premature baboons. The animals were killed at 72 hours of age and tissue samples examined for radioactivity. Maximum activity was found in the luminal contents, and activity in the liver and spleen was higher than in bone marrow, the site where free isotope is normally deposited. These findings suggest that some intact milk leucocytes may cross from the gastrointestinal tract into the neonatal circulation. Also the high activity in gastrointestinal tissue that had been washed several times indicates that leucocytes adhere to mucosa or lie intramurally. We speculate that the presence of leucocytes in the gastrointestinal tract 60 hours after a single breast feed can provide an important defence mechanism against infection.

Animals↗
PubMed1989

Treatment of patent ductus arteriosus after exogenous surfactant in baboons with hyaline membrane disease.

The effect of early treatment of patent ductus arteriosus (PDA) on the acute course of hyaline membrane disease was tested in a primate model, after intratracheal administration of 100 mg/kg exogenous bovine surfactant phospholipids at mean ages between 2.3-2.4 h. Twenty-two premature baboons were divided into four groups: seven animals were controls (group A); five were treated with surfactant but PDA was not intervened (group B); in five surfactant treatment was followed by three doses of 0.2 mg/kg intravenous indomethacin beginning at a mean age of 5.5 h (group C); and in five surfactant treatment was followed by a surgical ligation of PDA between 5-5.5 h of age. After surfactant instillation in groups B, C, and D, a prompt and sustained improvement was noted in a/APO2, mean airway pressure, ventilator efficiency index and pulmonary compliance. However, no consistent differences were found in the respiratory variables within the surfactant treated groups during the 72-h experiment: the respiratory course in the animals treated for PDA (groups C and D) was generally similar to the animals in which PDA was not treated (group B). In animals treated with surfactant and indomethacin (group C) the mean aortic blood pressure was maintained more optimally as compared to the other three groups. These findings suggest that although a significant early ductal shunting does occur after exogenous surfactant therapy in this animal model, the expected pulmonary deterioration does not occur, and an early abrupt interruption of PDA does not seem to provide additional advantage to the immediate course of hyaline membrane disease.

Animals↗