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Biomedical subjects

T Sugimoto

Publications and source records attributed to T Sugimoto.

At least 541 records · Page 30Linked to original sources

[A case of an intrapulmonary lymph node indistinguishable from carcinoma of the lung by CT].

A 64-year-old female was referred to our hospital for further examination of a coin lesion, 8 mm in diameter, superimposed on the right ninth posterior rib. CT revealed a nodule, close to the minor fissure, with spiculation, which seemed to be connected with the pulmonary vein. Since the bronchofiberscopic examination revealed no histological diagnosis, the exploratory thoracotomy was performed. The nodule was found to be a 10 x 7 x 5 mm black mass located subpleural at the minor fissure. Histologically, it was recognized as a lymph node with anthracosis and silicotic nodules.

Diagnosis, Differential↗

[Immunologic alterations after splenectomy for trauma].

The effects of splenectomy for trauma patients on immunologic function were studied. Various immunologic indices including humoral and cellular immunity were serially measured up to one year in thirteen adult patients with blunt trauma: All the patients recovered from the initial injury and were good health at 12 month except for one died at ten month from unrelated cause. Complements and immunoglobulins decreased following splenectomy, then rapidly increased to normal or above normal levels and maintained the level throughout the one year period. Contrary to previous reports, Ig-M levels were not decreased after splenectomy. Anti-pneumococcal antibody (Pn-ab) was below effective concentration at one year except one case. Lymphocyte subpopulation was characterized by decreased T (OKT-3) cells and inverted helper/suppressor ratio. Lymphocyte blast formation was suppressed before surgery and remained low throughout the period. This study demonstrated that the humoral immunity was reserved after splenectomy, while cellular immunity such as helper/suppressor ratio and lymphocyte blast formation was impaired even one year after injury in most patients. Increased Ig-M levels after splenectomy in this study might suggest different immune response in Japanese. Decreased Pn-ab would justify the use of anti-pneumococcal vaccine after splenectomy for trauma.

Accidents, Traffic↗

Immunohistochemical proof of intraneural localization of herpes simplex virus in experimental retinitis.

A unilateral intravitreal inoculation of herpes simplex virus type 1 (HSV-1) induced bilateral retinitis and encephalitis in the rat. Immunohistochemistry was employed to clarify the pathway of transmission of HSV-1 from the inoculated eye to the contralateral eye, and to identify localization of the viral antigen in the retina, optic nerve and brain. At an early stage of the post-inoculation period, HSV-1 immunoreactivity was first seen in the cytoplasm of Müller cells and then in various cells of the inner nuclear layer in the inoculated eye. At a later stage, HSV-1 immunoreactivity was seen in some retinal ganglion cells and optic nerve fibers in the inoculated eye. In the brain, HSV-1 was found in the optic chiasm, bilateral primary visual centers (bilateral suprachiasmatic nuclei, bilateral lateral geniculate nuclei, bilateral superior colliculus and bilateral pretectum) and bilateral visual cortex. HSV-1 was also demonstrated in the retinal ganglion cells, neural cells in the inner nuclear layer, and Müller cells in the contralateral eye. We found that HSV-1 antigen in the retina of the contralateral eye was transmitted through the optic nerve, visual pathway and nuclei, but not through the blood stream.

Animals↗

[A case report on a reconstructive operation of a traumatic tricuspid regurgitation with a congenital defect of the left pericardium].

We reported a successful tricuspid valve replacement in a 58-years old man, who had easy fatiguability after 14 years of a blunt chest trauma. The preoperative examination revealed a marked cardiomegaly with deformation of both ventricles and grade 4 tricuspid regurgitation caused by the prolapse of the anterior leaflet. The operative inspection revealed a left pericardial defect with a diameter of 10 cm and a torn anterior papillary muscle. Since a usual plastic procedure did not improve the regurgitation, a Carpentier-Edward bioprosthetic valve was implanted in the supra annular position. Atrioventricular conduction was preserved. The tricuspid valve was not resected to preserve the ventricular function. The patient recovered his own activity.

Heart Injuries↗

[Clinical significance of the measurement of the urinary concentration of iodine in differentiating silent thyroiditis from Graves' disease].

In order to differentiate silent thyroiditis (SLT) from Graves' disease, the usefulness of the measurement of the urinary concentration of iodine was evaluated in this study. The subjects employed were 39 patients with SLT and 40 patients with Graves' disease. Patients were advised to avoid any iodine-containing food or medication for a week before the examination. The urinary concentration of iodine (UI) and the serum concentration of thyroid hormones were determined. UI was calculated from the amount of iodine in the spot urine by multiplying it by the ratio of iodine to creatinine. Since the UI value thus obtained was significantly well correlated with the UI value for 24 hour urine, the former value was used instead of the latter value thereafter. Mean UI value in the patients with SLT was 482.4 +/- 296.4 mu g/day and that in the patients with Graves' disease was 169.8 +/- 75.2 mu g/day, the former value being significantly higher than the latter (p < 0.0001). A strong and significant correlation between UI and the serum concentration of FT4 or T3 (TT3) was found in the patients with SLT (r = 0.76, p < 0.0001 and r = 0.54, p < 0.02), but not in those with Graves' disease (r = 0.34, p = 0.07 and r = 0.24, p = 0.14) Mean UI/FT4 ratio and mean UI/TT3 ratio was significantly higher in patients with SLT than those with Graves' disease and the overlaps in the ratios between these two groups were very slight. These results indicate that both the ratios of UI/FT4 and UI/TT3 were useful parameters to differentiate SLT from Graves' disease. The higher UI value observed in the patients with SLT was thought to be due to the increase in the amount of inorganic iodine which was liberated from the iodinated material leaked from the damaged thyroid tissue by the deiodinating mechanism in the peripheral tissues.

Creatinine↗

Essential cysteine residues for cyclic ADP-ribose synthesis and hydrolysis by CD38.

We have recently demonstrated that cyclic ADP-ribose (cADPR) serves as a second messenger for glucose-induced insulin secretion (Takasawa, S., Nata, K., Yonekura, H., and Okamoto, H. (1993) Science 259, 370-373) and that human leukocyte antigen CD38 has both ADP-ribosyl cyclase and cADPR hydrolase activities (Takasawa, S., Tohgo, A., Noguchi, N., Koguma, T., Nata, K., Sugimoto, T., Yonekura, H., and Okamoto, H. (1993) J. Biol. Chem. 268, 26052-26054). Although the amino acid sequence of Aplysia ADP-ribosyl cyclase exhibits a high degree of amino acid sequence identity with that of CD38, the Aplysia enzyme shows only ADP-ribosyl cyclase but not cADPR hydrolase. In the present study, we introduced site-directed mutations to CD38 and found that C119K- and/or C201E-CD38 exhibited only ADP-ribosyl cyclase activity. Furthermore, Aplysia ADP-ribosyl cyclase into which we introduced the mutations K95C and E176C, which correspond to residues 119 and 201 of human CD38, exhibited not only ADP-ribosyl cyclase activity but also cADPR hydrolase. These results indicate that cysteine residues 119 and 201 in CD38 have crucial roles in the synthesis and hydrolysis of cADPR.

ADP-ribosyl Cyclase↗

Molecular cloning and functional expression of a cDNA encoding the human V1b vasopressin receptor.

Arginine vasopressin modulates the release of adrenocorticotropic hormone, beta-endorphin, and prolactin from the anterior pituitary. Release is mediated by the V1b receptor through the mobilization of intracellular Ca2+ by phosphatidylinositol hydrolysis. In contrast to its well characterized peripheral actions, such as antidiuresis, contraction of vascular smooth muscle, and stimulation of hepatic glycogenolysis, the exact site and mechanism of vasopressin action in the pituitary remain unclear. This is largely due to a lack of information on the molecular identity and exact localization of the V1b receptor. This lack prompted us to try to isolate this receptor subtype. Here we report the molecular cloning and functional expression of a complementary DNA encoding the human V1b receptor. The deduced 424-amino acid sequence of the receptor has highest overall homology with the V1a, V2, and oxytocin receptors, with homologies of 45, 39, and 45%, respectively. The receptor expressed in COS-1 cells has a single binding site for arginine vasopressin with a Kd of 0.17 +/- 0.04 nM. It binds various agonists and antagonists of vasopressin with affinities distinct from those of V1a and V2 receptors but consistent with those anticipated for the V1b receptor on the basis of the pharmacological studies. Furthermore, arginine vasopressin evoked calcium-dependent chloride current in Xenopus oocytes transfected with the receptor, which was not affected by a V1a/V2 antagonist. In contrast, the current evoked in oocytes transfected with V1a receptor was abolished by the antagonist. Northern blot analysis revealed that the receptor expression is restricted to the pituitary. These data clearly indicate that the cloned cDNA encodes the V1b receptor.

Amino Acid Sequence↗

c-Fos induction in the rat spinal dorsal horn partially deafferented by dorsal rhizotomy.

The 4th and 5th segments of the lumbar (the L4 and L5) dorsal horn receive primary input from the sciatic receptive fields through the L4 and L5 dorsal roots. Noxious stimulation of the hindpaw with formalin induces c-Fos in neurons in superficial laminae (I and II) of these dorsal horn segments. Rhizotomy of the L5 dorsal root 2 days before stimulation resulted in a marked reduction in the number of neurons with c-Fos protein-like immunoreactivity (fos-neurons). At 3 weeks after the L5 rhizotomy, the number of fos-neurons in laminae I and II significantly increased compared to that at 2 days post-rhizotomy. This result indicates that chronic partial deafferentation by dorsal rhizotomy increases responsiveness of superficial dorsal horn neurons to spared primary input.

Animals↗

Parvalbumin, calretinin and carbonic anhydrase in the trigeminal and spinal primary neurons of the rat.

The cell-body size of parvalbumin-immunoreactive (-ir) primary neurons was measured in the trigeminal (TG) and lumber dorsal root ganglia (DRG). In the DRG, parvalbumin-ir was mostly detected in large cells (94% in the range of 600-2800 microns2). Parvalbumin-ir TG cells were smaller than similar DRG cells and yet parvalbumin-ir TG cells of < 400 microns2 (2.86%) were rare. Trichrome stains for parvalbumin, calretinin (CR) and carbonic anhydrase (CA), and for parvalbumin, calcitonin gene-related peptide (CGRP) and CA were performed to estimate possible overlap of these substances. Virtually all parvalbumin-ir DRG cells contained CA activity while a small subpopulation (28.5%) of CR-ir DRG cells lacked CA activity. All the CR-ir DRG cells that exhibited CA were also ir for parvalbumin. 31.1% of parvalbumin-ir DRG cells exhibited CR-ir while 71.5% of CR-ir DRG cells showed parvalbumin-ir. All the CR-ir DRG cells of < 400 microns2 lacked CA activity and parvalbumin-ir while all those of > 800 microns2 exhibited both activities. Approximately 30% of CR-ir DRG cells in the size range of 400-800 microns2 co-expressed CA. DRG cells co-expressing parvalbumin and CGRP were rare (approximately 1%). As was the case for the DRG, most of parvalbumin-ir TG cells exhibited CA activity (89.24%) and lacked CGRP-ir (96.6%). CR-ir TG cells were also subdivided into two groups; one with and the other without co-expression of CA. Unlike in the DRG, however, co-expression of parvalbumin and CR could never be detected in the TG.

Animals↗

Molecular and clinical study of 61 Angelman syndrome patients.

We analyzed 61 Angelman syndrome (AS) patients by cytogenetic and molecular techniques. On the basis of molecular findings, the patients were classified into the following 4 groups: familial cases without deletion, familial cases with submicroscopic deletion, sporadic cases with deletion, and sporadic cases without deletion. Among 53 sporadic cases, 37 (70%) had molecular deletion, which commonly extended from D15S9 to D15S12, although not all deletions were identical. Of 8 familial cases, 3 sibs from one family had a molecular deletion involving only 2 loci, D15S10 and GABRB3, which define the critical region for AS phenotypes. The parental origin of deletion, both in sporadic and familial cases, was exclusively maternal and consistent with a genomic imprinting hypothesis. Among sporadic and familial cases without deletion, no uniparental disomy was found and most of them were shown to inherit chromosomes 15 from both parents (biparental inheritance). A discrepancy between cytogenetic and molecular deletion was observed in 14 (26%) of 53 patients in whom cytogenetic analysis could be performed. Ten (43%) of 23 patients with a normal karyotype showed a molecular deletion, and 4 (13%) of 30 patients with cytogenetic deletion, del(15) (q11q13), showed no molecular deletion. Most clinical manifestations, including neurological signs and facial characteristics, were not distinct in each group except for hypopigmentation of skin or hair. Familial cases with submicroscopic deletion were not associated with hypopigmentation. These findings suggested that a gene for hypopigmentation is located outside the critical region of AS and is not imprinted.

Adolescent↗

Ki-ras and c-myc oncogene expression measured by coamplification polymerase chain reaction.

Ki-ras and c-myc oncogene mRNA in carcinoma tissue was quantitatively detected by the coamplification polymerase chain reaction. After the reverse transcription of the mRNA mixture with random hexanucleotide primer the coamplification polymerase chain reaction of the oncogene and the internal standard beta-actin cDNA was done. The amount of oncogene mRNA was calculated from the coamplified product ratio. Ki-ras expression in a human gastric cancer strain H-111 was estimated to 5 percent of beta-actin. The expression of c-myc mRNA in colorectal carcinoma tissue was observed to be ten to one hundred times higher than normal mucosa. Gene expression was compared numerically in mole/liter without using hybridization and radioactive probes.

Actins↗

Neural parvalbumin and calretinin in the tooth pulp.

Parvalbumin- and calretinin-immunoreactivities (CR-irs) were examined in the molar tooth pulp of the rat using immunohistochemical methods. CR-ir fibers were further classified based on the tachykinin-ir revealed by a double immunofluorescence method. The rat root pulp contained three types of nerve fibers; parvalbumin-ir smooth fibers, CR-ir (TK-negative) smooth fibers and CR-ir (TK-ir) varicose fibers. These fibers projected toward the roof of the pulp chamber and pulp horn without marked ramification. In the subodontoblastic layer at the roof of the pulp chamber and pulp horn, parvalbumin-ir smooth fibers repeatedly ramified and extended varicose terminals into the odontoblastic layer. CR-ir (TK-negative) smooth fibers reached the subodontoblastic layer without marked ramification and gave rise to varicose terminals that appeared to terminate within the subodontoblastic layer. On the other hand, CR-ir (TK-ir) varicose fibers proceeded to the subodontoblastic layer at the roof of the pulp chamber and pulp horn, where they ramified and penetrated the odontoblastic layer. The present study indicates that the rat tooth pulp contains myelinated parvalbumin-ir and CR-ir (TK-negative) fibers, and unmyelinated CR-ir (TK-ir) fibers, and that they project varicose terminals to the subodontoblastic and odontoblastic layers. The central projection sites of these sensory fibers have yet to be revealed.

Animals↗

Characterization of the human gene (PTGS2) encoding prostaglandin-endoperoxide synthase 2.

The human gene (PTGS2) encoding an inducible isozyme of prostaglandin-endoperoxide synthase (prostaglandin-endoperoxide synthase 2) that is distinct from the well-characterized and constitutive isozyme (prostaglandin-endoperoxide synthase 1), was isolated using a polymerase-chain reaction-generated cDNA fragment probe for human prostaglandin-endoperoxide synthase 2. Nucleotide sequence analysis of the entire human prostaglandin-endoperoxide-synthase-2 gene demonstrated that it is more than 8.3 kb in size and consists of ten exons; this gene is very similar to the murine and chicken prostaglandin-endoperoxide-synthase-2 genes. The structures of exons in the human prostaglandin-endoperoxide-synthase-2 gene were also similar to those of the human prostaglandin-endoperoxide-synthase-1 gene (PTGS1). However, the sizes of introns in the human prostaglandin-endoperoxide-synthase-2 gene were generally smaller than those of the human prostaglandin-endoperoxide-synthase-1 gene. Primer-extension analysis indicated that the transcriptional-start site is 134 bases upstream of the translational-initiation site. The sequence of the 1.69-kb region of nucleotides preceding the transcriptional-start site and the first 0.8-kb intron contained a canonical TATA box and various transcriptional-regulatory elements (CArG box, NF-IL6, PEA-1, myb, GATA-1, xenobiotic-response element, cAMP-response element, NF-kappa B, PEA-3, Sp-1 and 12-O-tetradecanoyl-phorbol-13-acetate-response element). The nucleotide sequence of the 5'-flanking region (275 bp) of the human prostaglandin-endoperoxide-synthase-2 gene showed 63% similarity to the sequence of murine prostaglandin-endoperoxide-synthase-2/TIS10 gene, but essentially no homology to the chicken prostaglandin-endoperoxide-synthase-2 gene, and human and murine prostaglandin-endoperoxide-synthase-1 genes. A fluorescence in situ hybridization study showed that the human genes coding for prostaglandin-endoperoxide synthase 1 (PTGS1) and prostaglandin-endoperoxidase synthase 2 (PTGS2) were mapped to distinct chromosomes 9q32-q33.3 and 1q25.2-q25.3, respectively, indicating that these genes are not genetically linked.

Amino Acid Sequence↗

cDNA cloning and regional distribution of a novel member of the opioid receptor family.

We have cloned a cDNA for a novel member of the opioid receptor family, designated as ROR-C, from the rat cerebrum cDNA library using the probe derived from the delta-opioid receptor subtype cDNA. The deduced amino acid sequence of ROR-C shows high homology with those of ROR-A (rat delta-opioid receptor subtype), ROR-B (rat mu-subtype) and ROR-D (rat kappa-subtype). RNA blot hybridization and in situ hybridization analysis revealed that ROR-C mRNA is expressed in discrete regions of the rat central nervous system.

Amino Acid Sequence↗

Changes in c-fos induction in dorsal horn neurons by hindpaw formalin stimulation following tibial neurotomy.

The hindpaw was partially denervated by the tibial nerve transection in adult rats. At post-transection intervals varying from 2 to 168 days, the hindpaw was stimulated bilaterally by subcutaneous injection of formalin. The excitability of dorsal horn neurons was expressed as the percentage ratio of the number of formalin-induced c-fos protein-like immunoreactive neurons (fos-neurons) on the neurotomized (experimental) side to that on the un-neurotomized (control) side. At 2 days post-injury, a marked reduction in the number of fos-neurons was noted in laminae I-VII of the lumbar spinal cord. Among these, reduction was greatest in the medial 3/8 of laminae I and II (terminal field of the tibial nerve, i.e. tibial territory), and smallest in the lateral 5/8 of the same laminae (the peroneal/hip territory). The low level of c-fos induction remained unchanged for 7 days. At 14 days, the excitability of neurons in all laminae showed a marked increase compared to the post-injury days 2 and 3 combined. Thereafter, the increased level of excitability in the tibial territory was maintained throughout the post-injury period examined in this study. On the other hand, a statistically significant increase in excitability in the peroneal/hip territory was only seen between 14 and 28 days and the excitability almost returned to the baseline (days 2 and 3 post-transection combined) level at 42 days. Although deeper laminae (III-VII) contained much less formalin-induced fos-neurons, they also exhibited post-injury excitability changes with a temporal pattern similar to that of the peroneal/hip territory of laminae I and II.(ABSTRACT TRUNCATED AT 250 WORDS)

Afferent Pathways↗

Protein kinase C is crucial for the stimulation of sodium-dependent phosphate transport by parathyroid hormone-related peptide in osteoblast-like cells.

In the present study, we investigated the role of parathyroid hormone-related peptide (PTHrP)-responsive dual signal transduction systems in the regulation of sodium-dependent phosphate (Pi) transport by PTHrP in UMR-106 cells. Exposure of the cells to 10(-7) M human (h) PTHrP-(1-34) induced a significant increase in Pi uptake within 15 min of incubation. The peptide stimulated Pi uptake dose-dependently at the range of 10(-11)-10(-7) M. Activation of protein kinase C (PKC) by 12-O-Tetradecanoyl phorbol-13-acetate (TPA) also increased Pi uptake in time- and dose-dependent manners similar to PTHrP. In contrast, neither activation of adenylate cyclase by 10(-5) M forskolin nor calcium ionophore treatment with 10(-7) M A23187 affect Pi uptake. These agents failed to influence on Pi uptake even in combined treatment with TPA. The PTHrP-induced increase in Pi uptake was strongly inhibited by pretreating cells with PKC inhibitors, 1-(5-isoquinolinylsulfonyl)-2-methylpiperazine dihydrochloride (H-7) (50 microM), and by down-regulating PKC with a prolonged TPA pretreatment. These results indicate that the messenger system mediated by PKC, rather than adenylate cyclase or cytosolic calcium, plays a crucial role in the regulation of sodium-dependent Pi transport by PTHrP in the osteoblast-like cells.

1-(5-Isoquinolinesulfonyl)-2-Methylpiperazine↗

Calcitonin directly acts on mouse osteoblastic MC3T3-E1 cells to stimulate mRNA expression of c-fos, insulin-like growth factor-1 and osteoblastic phenotypes (type 1 collagen and osteocalcin).

The present study was performed to examine whether calcitonin directly acted on mouse osteoblastic MC3T3-E1 cells to stimulate the mRNA expression of insulin-like growth factor-1 (IGF-1) and c-fos, followed by an increase in their proliferation and differentiation. Eel calcitonin increased [3H]thymidine incorporation and alkaline phosphatase activity as well as the mRNA expression of type 1 collagen and osteocalcin which were characteristic of osteoblasts. Eel calcitonin (10(-8)M) induced c-fos mRNA transiently after its addition, followed by gene expression of IGF-1, an important autocrine/paracrine growth factor in the regulation of osteoblastic proliferation. We first demonstrated that calcitonin directly acted on osteoblasts to stimulate transcription of c-fos and IGF-1 genes as well as functional phenotypes including type 1 collagen and osteocalcin.

Animals↗