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Biomedical subjects

T Homma

Publications and source records attributed to T Homma.

At least 91 records · Page 5Linked to original sources
PubMed1994

Epitope analysis of SPan-1 and DUPAN-2 using synthesized glycoconjugates sialyllact-N-fucopentaose II and sialyllact-N-tetraose.

Epitope analysis of SPan-1 and DUPAN-2 was compared with that of CA19-9 using the synthesized glycoconjugate sialyllacto-N-fucopentaose II (SLF II, sialyl-Lewis(a)) and its precursor, sialyllact-N-tetraose (LSTa, sialyl-Lewis(c)), conjugated to human serum albumin. The CA19-9 and DUPAN-2 assay systems specifically recognized SLF II and LSTa, respectively. The SPan-1 assay system recognized both SLF II and LSTa, although the reactivity with the former was far stronger than that with the latter. These results were, in general, compatible with those obtained from assaying these markers in the sera of two pancreatic cancer patients with definite Lewis-negative phenotype and in the sera of 39 CA19-9-negative pancreatic cancer patients. In conclusion, DUPAN-2 is the precursor of CA19-9 and is accumulated in the sera of pancreatic cancer patients with Lewis-negative phenotype and SPan-1 has an advantage over CA19-9 in the diagnosis of patients with Lewis-negative phenotype, although both markers have almost the same sensitivity for this malignancy.

Antibodies, Monoclonal↗
PubMed1994

CA19-9 as a screening and diagnostic tool in symptomatic patients: the Japanese experience.

Although the prognosis for pancreatic cancer is generally poor, the Japanese Pancreatic Cancer Register reported in 1992 that the survival rate for resected pancreatic cancer was much higher than that for more conservative treatment. T1 and T2 pancreatic tumors are much more frequently resectable than are T3 and T4 tumors, and the 5-year survival rate for unresected T2, T3, and T4 cases is 0%. These findings emphasize the importance of early diagnosis of resectable pancreatic cancer. CA19-9 has shown satisfactory sensitivity in detecting advanced pancreatic cancer; we sought to determine the effectiveness of CA19-9 as part of a screening program for early cancer. Using elastase 1, CA19-9, and ultrasonography, we developed and tested a program of mass screening on persons presenting with and without abdominal complaints.

Adult↗
PubMed1994

Adaptation of Aspergillus niger to several antifungal agents.

Adaptation of Aspergillus niger to short-term stress induced by three antifungal agents [amphotericin B (AMPH), miconazole (MCZ), and ketoconazole (KCZ)] was observed and evaluated quantitatively using individual hyphae. Spores were inoculated onto a poly-L-lysine-coated glass plate making up the base of a culture vessel. Potato dextrose broth (PDB) was added and the vessel incubated for 24 h at 28 degrees C. The growth rate of an arbitrarily selected test hypha was measured automatically. Exposure to AMPH (0.075 micrograms ml-1) stopped the growth of the hypha. After washing with PDB, the same concentration of AMPH was applied again. The growth of the test hypha was not inhibited. This phenomenon was defined as adaptation to the short-term stress of AMPH. Similarly, adaptation was observed with MCZ (0.01 microgram ml-1) and KCZ (0.5 microgram ml-1). The time required for the test hypha to restart growth after washing with PDB depended upon the concentration of MCZ or KCZ, but not upon the concentration of AMPH.

Adaptation, Physiological↗
PubMed1994

Mechanical stretch/relaxation of cultured rat mesangial cells induces protooncogenes and cyclooxygenase.

In cultured rat glomerular mesangial cells, continuous cycles of stretching and relaxation (stretch/relaxation) stimulate cell proliferation, protein synthesis, and prostaglandin production. We examined regulation of gene expression that may underlie these alterations in cell functions. Stretch/relaxation caused time-dependent induction of the immediate early genes, c-fos and zif 268/egr-1, with maximal increases occurring between 15 and 30 min. The mitogen-inducible prostaglandin G2/H2 synthase (PGH2S-2) gene was also induced within 30 min of stretch/relaxation, with concomitant increases in the immunoreactive PGH2S-2 protein. These gene inductions were preceded by transient translocation of protein kinase C activity from cytosol to membrane as well as by increases in 45Ca2+ uptake and total cellular calcium content. The stretch/relaxation-induced expression was suppressed by protein kinase C inhibition, whereas less profound inhibition was observed with inhibition of calcium influx in low (100 nM) calcium buffer. These findings indicate that in mesangial cells mechanical stress induces expression of the protooncogenes and the mitogen-inducible cyclooxygenase primarily through protein kinase C-dependent mechanisms.

Animals↗
PubMed1994

Roles of neutrophil elastase and superoxide anion in leukotriene B4-induced lung injury in rabbit.

The effects of a competitive neutrophil elastase (NE) inhibitor, ONO-5046, and a recombinant human superoxide dismutase on leukotriene B4 (LTB4)-induced polymorphonuclear leukocyte (PMN)-mediated increase in microvascular permeability in isolated non-blood-perfused rabbit lungs were studied. Pulmonary microvascular permeability and lung edema were evaluated by use of the fluid filtration coefficient (Kf) and the wet-to-dry lung weight ratio (W/D), respectively. Pulmonary capillary pressure was estimated by the double occlusion technique. NE activity in the perfusate was determined using a spectrophotometric method. The PMNs (2-3 x 10(8) cells) were added into the perfusate in all groups of lungs. Injection of LTB4 (5 micrograms) increased Kf and W/D without affecting pulmonary arterial or capillary pressure. The LTB4-induced lung injury was closely associated with the increase in NE activity in the perfusate. Infusion of ONO-5046 (1 or 10 mg.kg-1 x h-1) inhibited the LTB4-induced increases in Kf, W/D, and perfusate NE activity in a dose-dependent fashion. Infusion of recombinant human superoxide dismutase (80,000 U.kg-1 x h-1) attenuated the LTB4-induced increases in Kf and W/D, although it did not influence the elevation of perfusate NE activity induced by LTB4. These results suggest that both NE and superoxide anion play important roles in the LTB4-induced PMN-mediated increase in pulmonary microvascular permeability.

Animals↗
PubMed1994

Temporary change of compound action potential amplitude after intense sound exposure.

Intense sound induces a temporary or permanent threshold shift. The aim of this study is to make an experimental model for temporary threshold shift (TTS) using guinea pigs. In this study, two kinds of sound exposure were used for inducing a threshold shift in the guinea pig; one of 110 dB SPL at 10 kHz for 10 min and the other of 120 dB SPL at 10 kHz for 5 min. The former condition produced different levels of reduction in compound action potential (CAP) immediately after sound exposure and different steady levels of CAP amplitude after recovery (within 120 min) in 10 guinea pigs. The latter condition produced a total loss of CAP amplitude immediately after sound exposure in 8 of 9 guinea pigs, and this condition continued for 120 min in 7 of the 9 guinea pigs. Additionally, in 2 of 3 guinea pigs which were exposed the sound of 120 dB SPL at 10 kHz for 5 min, the CAP amplitudes were almost the same as those of control animals 1 day after the exposure. One the basis of these results, we consider the sound of 120 dB SPL at 10 kHz for 5 min to be the optimal intensity and frequency of sound and duration of exposure for producing a TTS in the guinea pig.

Acoustic Stimulation↗
PubMed1994

[Evaluation of physical exercise and fatigue sensation by CFSI (Cumulative Fatigue Symptoms Index)].

Cumulative Fatigue Symptoms Index (CFSI) is used for workers' subjective assessment of feeling of fatigue and of symptoms. Until now, this index has been used in the analysis of members of the same occupation. The purpose of this study is to examine fatigue symptoms in workers and to assess by CFSI the effect of regular physical exercise. Study participants were an exercise group (n = 67) and a non-exercise group (n = 115) of older workers, aged from 30 to 69 years. The CFSI questionnaire was distributed to all participants and the former group (exercise) answered two descriptive questions concerning the aim and subjective effects of physical exercise. As a result, it was found that mental fatigue symptoms decreased in the exercise group even after considering the differences in managerial position, subjective senses on health and marital status which are related to degree of feelings of fatigue. Weakened vitality was significantly less in the exercise group than the non-exercise group. Therefore, we concluded that weakened vitality would be needed to be regarded on an assessment scale for effects caused by exercise. It has also been considered that we should investigate general fatigue in assessing physical fatigue relating to one's lifestyle.

Adult↗
PubMed1994

[Anatomy of intrinsic hand muscles].

The intrinsic hand muscles consist of the thenar, hypothenar and midcarpal muscles. Our recent studies on these muscles and their innervation have revealed several new findings which would enhance standard anatomical descriptions of these muscles. 1) R. profundus of the ulnar nerve sends off branches to interossei in order of the spatial arrangement of these muscles. 2) Regarding the thenar muscles, M. opponens pollicis, M. flexor pollicis brevis and M. adductor pollicis form a single mass without clear borders, and their supplying nerves originate from the thenar ansa which is established by anastomosis of one or two branches of the median nerve and a terminal branch of R. profundus of the ulnar nerve. We call this muscle mass the "deep thenar muscle." Due to the lack of definite margins, it is understandable that the anatomical descriptions of the thenar muscles have been so varied. The division of the deep thenar muscle into the three muscles might be regarded as only an artificial division, according to arbitrary criteria.

Hand↗
PubMed1994

[A case of dissection of the right aortic arch, with consideration on the development of its major branches and ductus arteriosus].

In the present study, we reported a case of the right aortic arch which was found in the course of dissection at Juntendo University in 1993 from a cadaver of a 92-year-old female. The present case possessed as its terminal branch the right subclavian artery. The ascending aorta arose from the left ventricle and ran upwards, curved dorsally and became the right aortic arch. The arch passed on the right side of the trachea and esophagus, curved right posteriorly and became the thoracic aorta which descended on right side of the vertebral column. The aortic arch sent off the left brachiocephalic artery, the right common carotid artery and the right subclavian artery in this order and connected with the pulmonary artery by the right ligamentum arteriosum. The present case represents the 11th report of dissection of a right aortic arch in Japan which was type M according to the classification system of Adachi-Williams-Nakagawa. Type M is subdivided into three subtypes depending on the pattern of the ligamentum arteriosum. The right ligamentum arteriosum has been found in three cases including the present study. We critically discussed previous explanations and theories on the developmental processes of the right aortic arch and its variable major branches and ductus arteriosus.

Aged↗
PubMed1994

Divergent expression of EtA and EtB receptors in response to cyclosporine in mesangial cells.

We examined the effects of cyclosporine (Cy) on preproendothelin-1 (prepro Et-1) and both Et receptors, A-type (EtA) and B-type (EtB), in rat glomerular mesangial cells. Cy at 10(-5) mol/L, the concentration relevant to tissue levels in vivo, increased mRNA for prepro Et-1 after both 1 and 3 hours to 183 +/- 14% (n = 8) and 147 +/- 12% (n = 9) of levels seen in control cells. A similar pattern was observed at a lower dose of Cy (10(-6) mol/L, the concentration relevant to plasma levels in vivo): at 1 hour, expression increased to 146 +/- 15% (n = 5); at 3 hours, expression was 159 +/- 25% (n = 8). Concomitant with these changes in expression of prepro Et-1 mRNA, the Et-1 protein nearly doubled at 3 hours. Both EtA and EtB mRNA were expressed in unstimulated mesangial cells and were affected differently by Cy. Little change was observed in the EtA mRNA. In contrast, EtB mRNA increased with Cy (10(-5) mol/L) up to 129 +/- 8% (n = 6) at 1 hour and 265 +/- 62% (n = 3) at 3 hours. A similar effect was seen with the lower dose of Cy: EtB expression increased to 129 +/- 9% (n = 6) of control value at 1 hour and 253 +/- 74% (n = 4) at 3 hours. These results indicate that Cy enhances expression of mRNA for prepro Et-1 and production of mature Et-1 by glomerular mesangial cells. Further, Cy has differential effects on EtA and EtB, affecting EtA minimally while markedly increasing the expression of EtB. These results constitute the first demonstration that Et receptor subtypes are modulated in a pathophysiological setting. The divergent modulation of EtA and EtB raises the possibility that there are differences in contribution of each of the receptor subtypes to pathophysiological mechanisms of Cy toxicity.

Animals↗
PubMed1993

Development of a flow system for the microscopic observation of cultured nerve cells and its application to the neurite growth control of PC12h-R.

A flow system has been developed for the continual microscopic observation of cultured nerve cells. The undefined effects of coexisting cells could be efficiently reduced by the continuous flow of a medium. The present flow system was useful also for the experiments requiring medium exchanges. Its performance was demonstrated by the repeated actions of NGF or db-cAMP to PC12h-R cells. The neurite projection and its retraction were repeatedly observed by the supply and the removal of those factors.

Animals↗
PubMed1993

Cyclooxygenase-derived metabolites of 8,9-epoxyeicosatrienoic acid are potent mitogens for cultured rat glomerular mesangial cells.

The mitogenic effects of 11(R)-hydroxy-8,9-epoxyeicosatrienoic acid (EET) enantiomers were investigated in cultured rat glomerular mesangial cells. Both 11(R)-hydroxylated 8(R),9(S)- and 8(S),9(R)-EET at 1 microM stimulated [3H]-thymidine incorporation to 300% and 280%, with 50% maximal effect occurring at 8 x 10(-9) M and 1 x 10(-8) M, respectively. Similar concentration-dependent effects were observed in stimulating induction of the immediate early gene, c-fos. Mitogenic activity of the 11(R)-hydroxylated enantiomers was not affected by prior downregulation of protein kinase C, suggesting involvement of protein kinase C-independent mechanisms. These findings suggest that either trans- or intracellular metabolism of 8,9-EET by cyclooxygenase occurs during inflammatory glomerular diseases and that the resulting metabolites are involved in mesangial cell proliferation.

8,11,14-Eicosatrienoic Acid↗
PubMed1993

Effect of indomethacin on postoperative protein metabolism after gastrectomy under total parenteral nutrition.

A randomized trial was undertaken to evaluate the effects of postoperative indomethacin (IDM) administration on protein metabolism in 20 patients who underwent an uncomplicated distal gastrectomy and were placed on post-operative total parenteral nutrition (TPN). Ten patients (the IDM group) received 50 mg of IDM every 8 h after operation up to postoperative day (POD) 4 while the other ten patients (the control group) received neither IDM nor any other non-steroidal anti-inflammatory drug, postoperatively. Though the requirement for postoperative plasma transfusion was significantly greater in the IDM group, the albumin level on POD 1 was significantly lower in this group than in the control group. The postoperative changes of C-reactive protein, retinol binding protein, and pre-albumin between the two groups showed no difference. Moreover, the urinary 3-methylhistidine excretion, N-balance, and plasma aminogram on POD 4 also demonstrated no difference. We thus concluded that post-operative IDM administration after elective surgery has no additional anti-catabolic effect on the presence of TPN.

Blood Proteins↗
PubMed1993

Effect of coexisting cells on the NGF-inducing neurite growth from PC12h-R.

Possible roles of coexisting cells in inducing neurite growth from a nerve cell were studied. Nerve growth factor (NGF)-inducing neurite growth from PC12h-R (a cell line derived from cultured nerve cells) was investigated at various cell densities. At the cell density 10(2)-10(4) cells/ml neurites appeared even without NGF. In contrast, no neurite appeared without NGF in single cell culture. The neurite growth observed in plural cell culture without NGF was only partially inhibited by antibody to NGF receptor (Ab-NGFR). However, the effect of the used medium alone was mostly inhibited by Ab-NGFR. These results suggest that the neurite inducing potency of coexisting cells is via different sites than the NGF receptor.

Animals↗