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Biomedical subjects

T Oka

Publications and source records attributed to T Oka.

At least 541 records · Page 30Linked to original sources
PubMed1995

[Simultaneous evaluation of myocardial perfusion and fatty acid metabolism using dynamic SPECT with single injection of 123I-15-(p-iodophenyl)-3-methyl pentadecanoic acid (BMIPP)].

The purpose of this study is to clarify whether dynamic SPECT (DECT) immediately after the injection of 123I-15-(p-iodophenyl)-3-methyl pentadecanoic acid (BMIPP) may represent myocardial perfusion imaging. Ten patients with unstable angina pectoris (UAP), 11 patients with acute myocardial infarction (AMI) and 6 patients with non-ischemic heart disease (NIHD) were studied using BMIPP myocardial scintigraphy with DECT. DECT acquisition was started 2 minutes after the injection of BMIPP, and DECT images were obtained every three minute for 15 minutes with 3-headed gamma camera SPECT system. Additionally, static SPECT images were acquired 30 minutes after the injection of BMIPP. These SPECT images of BMIPP were compared with thallium-201 myocardial perfusion images at rest. In UAP group, early DECT images showed almost the same findings as thallium-201 images in 8 of 10 patients, and SPECT images at 30 minutes after the injection showed reduced accumulation of BMIPP compared with thallium-201 images in all patients. In AMI group, early DECT images showed the same findings as thallium-201 perfusion images in 9 of 11 patients, and SPECT images at 30 minutes after the injection showed reduced accumulation of BMIPP compared with thallium-201 images in 5 of 11 patients. These results indicate that myocardial perfusion can be evaluated in the early image using DECT, in addition to myocardial fatty acid metabolism in the delayed image.

Adult↗
PubMed1995

[Intermittent mini-dose vancomycin intravenous administration and closed continuous irrigation technique applied to mediastinitis caused by MRSA following mitral valve replacement].

Mediastinitis caused by MRSA (Methicillin-Resistant Staphylococcus aureus) remains an intractable infection producing high mortality even in these days of advanced chemotherapy. The authors report a case of mediastinitis due to MRSA complicated with acute renal failure following mitral valve replacement. The patient's mediastinum had been thoroughly cleaned with physiological saline solution with 0.2% povidone iodine, and underwent a chemotherapy regimen of mini-dose vancomycin. The patient made favorable progress and recovered completely. Our patient's progress confirmed that when chemotherapy using vancomycin is administered in a patient whose condition is complicated with acute renal failure, closely monitoring the vancomycin serum concentration is essential. Intermittent mini-dose intravenous administration is sufficient to maintain an effective vancomycin serum concentration. In our case, vancomycin serum concentration measured before and at completion of dialysis revealed no appreciable decline.

Acute Kidney Injury↗
PubMed1995

[Renal autotransplantation for dissecting aneurysm].

Out of twenty-five patients operated on for dissecting aneurysm in our institution since January 1991, four patients had autotransplantation of the kidney. The renal autotransplantation and the segmental replacement of the descending aorta with the prosthesis were done at the same time in three of them, and segmental replacement of the distal aortic arch was followed by autotransplantation because of the postoperative acute renal failure in the other one. Postoperative renal function of simultaneously operated patients was good whereas the patient who had been treated by two-staged operation needed hemodialysis for two weeks after the autotransplantation. Postoperative scintigraphy showed fully recovered function of the autotransplanted kidneys with enlargement. CT scan showed that the false lumen of the dissecting aorta was reduced in size with increased intraluminal clot formation. Renal autotransplantation with entry closure is easy and safe technique and assures successful operative results for the dissecting aneurysm, restoring impaired renal blood flow.

Acute Kidney Injury↗
PubMed1995

[Prostatic adenocarcinoma showing features of endometrioid and mucinous carcinomas: a case report].

A 77-year-old male was admitted for the examination of post renal acute renal failure. Blood examination revealed renal dysfunction and elevation of carcinoembryonic antigen (CEA). Computed tomography and retrograde pyelography showed bilateral hydronephrosis due to ureteral stenosis. He died of renal failure and autopsy was done. Histologic findings showed moderately differentiated adenocarcinoma of the prostate associated with endometrioid and mucinous carcinoma, and metastases of retroperitoneal lymph nodes and multiple bones. Immunohistochemically, endometrioid carcinoma was positive for prostatic acid phosphate (PAP) and prostatic specific antigen (PSA), and negative for CEA. Mucinous carcinoma was negative for PAP and PSA, and positive for CEA. Including our case, 29 cases of endometrioid and 32 of mucinous carcinoma of the prostate reported in the Japanese literature are reviewed.

Acid Phosphatase↗
PubMed1995

Kupffer cells in multiple organ failure--their activation as revealed by immunohistochemistry for lysozyme, alpha 1-antichymotrypsin, and lectins.

It has been recently suggested that multiple organ failure (MOF) is caused by activation of inflammatory cells and subsequent release soluble factors from these cells. However, morphologic data to support this hypothesis is lacking. Thus, the present study was conducted to evaluate the activation of Kupffer cells in multiple organ failure by applying immunohistochemical techniques to formalin-fixed, paraffin-embedded autopsy materials. Eleven liver samples of multiple organ failure were stained for lysozyme, alpha 1-antichymotrypsin, and by lectins, such as ConA, RCA-I, WGA and PNA. Normal livers and diseased livers of miscellaneous origins were also stained and compared. In normal livers, Kupffer cells were generally negative or weakly positive for lysozyme, alpha 1-antichymotrypsin, ConA, RCA-I, and PNA, while they were positive for WGA. In multiple organ failure, by contrast, Kupffer cells showed stronger staining for alpha 1-antichymotrypsin, lysozyme, ConA, RCA-I, WGA, and PNA, indicating activation of Kupffer cells. Increased reaction to WGA and RCA-I was also observed in diseased livers of miscellaneous origins. These results are in agreement with the current hypothesis that activation of Kupfer cells is involved in the pathogenesis of MOF. Our findings also indicate, however, that activation of Kupffer cells is not a phenomenon unique to MOF.

Carbohydrates↗
PubMed1995

[Pulmonary involvement of collagen vascular diseases: studies on prognostic factors from basic and clinical viewpoints].

In 715 patients with collagen vascular diseases, interstitial lung disease and pulmonary hypertension were found to be important causes of death (37.5% and 6%, respectively). The prognosis of interstitial lung disease associated with collagen vascular disease was better than that of idiopathic interstitial pneumonia; patients with the latter were more likely to experience exacerbations. A distinct subgroup of patients with dermatomyositis and interstitial lung disease with a rapidly progressive course was characterized by mild muscle symptoms, low levels of creatine phosphokinase and negative tests for anti-Jo-1 antibody. CT scores and analysis of bronchoalveolar lavage fluid proved to be of some value in predicting outcome. Measurement of IL-6 in bronchoalveolar lavage fluid and local immunostaining for this pro-inflammatory cytokine were helpful in evaluating responses to therapy.

Antibodies, Antinuclear↗
PubMed1994

Multi-segmental and generalized suppression of postural muscle tone evoked by stimulating the dorsal tegmental field and the medial pontine reticular formation in acute decerebrate cats.

In acute decerebrate cat, stimulation of the dorsal tegmental field (DTF) of the caudal pons along its midline and the medial pontine reticular formation (mPRF) evokes generalized suppression of postural muscle tone. In this study, the effects of stimulation of the DTF area were compared with those evoked by stimulating the mPRF unilaterally or bilaterally. By stimulating the mPRF bilaterally, simultaneous suppression of tonic activities in the neck, lumbar back, forelimb and hindlimb muscles, bilaterally, was evoked as that evoked by stimulating the DTF area alone.

Animals↗
PubMed1994

Intracerebroventricular injection of prostaglandin E2 induces thermal hyperalgesia in rats: the possible involvement of EP3 receptors.

To determine what types of prostanoid receptors are involved in the central effect of prostaglandin E2 (PGE2) on nociception, we administered PGE2 and its agonists, i.e., 17-phenyl-omega-trinor PGE2 (an EP1 receptor agonist), butaprost (an EP2 receptor agonist), 11-deoxy PGE1 (an EP2/EP3 receptor agonist, EP2 >> EP3) and M&B28767 (an EP3 receptor agonist) into the lateral cerebroventricle (LCV) of rats and observed the changes of paw-withdrawal latency on a hot plate. The LCV injection of PGE2 (10 pg/kg-10 ng/kg), 11-deoxy PGE1 (100 pg/kg-10 ng/kg) and M&B28767 (1 pg/kg-100 pg/kg) produced a significant reduction in the paw-withdrawal latency. The maximal reduction was observed 15 min after the LCV injection of these drugs. Neither 17-phenyl-omega-trinor PGE2 (1 pg/kg-1 microgram/kg) nor butaprost (1 pg/kg-100 microgram/kg) induced any significant changes in the paw-withdrawal latency. The LCV injection of PGE2 (1 microgram/kg) and 17-phenyl-omega-trinor PGE2 (50 micrograms/kg) increased the latency only 5 min after LCV injection. These findings indicate that the LCV injection of PGE2 induces thermal hyperalgesia through EP3 receptors and analgesia through EP1 receptors by its central action in rats.

Alprostadil↗
PubMed1994

Characterization of the rabbit intestinal fructose transporter (GLUT5).

Recent studies suggest that the jejunal/kidney-type facilitative glucose transporter (GLUT5) functions as a high-affinity D-fructose transporter. However, its precise role in the small intestine is not clear. In an attempt to identify the fructose transporter in the small intestine, we measured fructose uptake in Xenopus oocytes expressing jejunal mRNA from five species (rat, mouse, rabbit, hamster and guinea-pig). Only jejunal mRNA from the rabbit significantly increased fructose uptake. We also cloned a rabbit GLUT5 cDNA from a jejunal library The predicted amino acid sequence of the 487-residue rabbit GLUT5 showed 72.3 and 67.1% identity with human and rat GLUT5 respectively. Northern-blot analysis revealed GLUT5 transcripts in rabbit duodenum, jejunum and, to a lesser extent, kidney. After separation of rabbit jejunal mRNA on a sucrose density gradient, the fractions that conferred D-fructose transport activity in oocytes also hybridized with rabbit GLUT5 cDNA. Hybrid depletion of jejunal mRNA with a GLUT5 antisense oligonucleotide markedly inhibited the mRNA-induced fructose uptake in oocytes. Immunoblot analysis indicated that GLUT5 (49 kDa) is located in the brush-border membrane of rabbit intestinal epithelial cells. Xenopus oocytes injected with rabbit GLUT5 cRNA exhibited fructose uptake activity with a Km of 11 mM for D-fructose. D-Fructose transport by GLUT5 was significantly inhibited by D-glucose and D-galactose. D-Fructose uptake in brush-border membrane vesicles shows a Km similar to that of GLUT5, but was not inhibited by D-glucose or D-galactose. Finally, cytochalasin B photolabelled a 49 kDa protein in rabbit brush-border-membrane preparations that was immunoprecipitated by antibodies to GLUT5. Our results suggest that GLUT5 functions as a fructose transporter in rabbit small intestine. However, biochemical properties of fructose transport in Xenopus oocytes injected with GLUT5 cRNA differed from those in rabbit jejunal vesicles.

Amino Acid Sequence↗
PubMed1994

Protein synthesis inhibitor phase shifts vasopressin rhythms in long-term suprachiasmatic cultures.

The effects of anisomycin, a protein synthesis inhibitor, on the circadian rhythm of arginine-vasopressin (AVP) release in organotypic slice cultures of the rat suprachiasmatic nucleus were examined. Anisomycin applied to the culture as a 6-h pulse shifted the phase of the AVP rhythm, depending on the circadian phase at which the pulse was given. The resultant phase-response curve consisted of a delay portion throughout the late subjective night and an advance portion in the middle of subjective day. The present findings suggest that protein synthesis is an important process which constitutes the circadian oscillation and/or the input pathway to the circadian pacemaker within the suprachiasmatic nucleus.

Animals↗
PubMed1994

Intracerebroventricular injection of interleukin-1 beta enhances nociceptive neuronal responses of the trigeminal nucleus caudalis in rats.

To assess the effect of interleukin-1 (IL-1) in the brain on nociception electrophysiologically, recombinant human IL-1 beta (rhIL-1 beta) (1 pg/kg to 1 microgram/kg, i.e., 0.29 pg-0.33 microgram/rat) was microinjected into the lateral cerebral ventricle of urethane-anesthetized rats and the changes of responses in the wide dynamic range (WDR) neurons in the trigeminal nucleus caudalis to noxious pinching of facial skin were observed. A significant enhancement in the responses of the WDR neurons to noxious stimuli was observed after the injection of rhIL-1 beta between 10 pg/kg and 1 ng/kg, which showed a maximal response at a dose of 100 pg/kg (29-33 pg/rat) which began to appear 5 min after injection, reached a peak within 25 min and then gradually subsided. However, this dose of rhIL-1 beta did not affect the responses of low threshold mechanoreceptive neurons to skin brushing. An increase in the dose of rhIL-1 beta by more than 10 ng/kg (up to 1 microgram/kg) had no effect on the nociceptive responses of the WDR neurons. The rhIL-1 beta-induced enhancement of nociceptive responses of WDR neurons was completely abolished by pretreatment with either IL-1 receptor antagonist, Na salicylate or alpha-melanocyte stimulating hormone. These results therefore provide electrophysiological evidence that IL-1 beta which is produced in the brain induces hyperalgesia in the rat.

Animals↗
PubMed1994

Human monoclonal antibody identified an immunoreactive tetrapeptide sequence (Lys-Tyr-Gln-Ile) in M(r) 43,000 protein of human melanoma.

The human monoclonal antibody (HuMAb) L92 reacts to an M(r) 43,000 protein associated with human melanoma. To identify the gene encoding its antigenic epitope, a complementary DNA expression library constructed from the human melanoma cell line UCLASO M14 was screened with HuMAb L92. DNA sequence analysis of the isolated clone revealed that the immunoreactive peptide was composed of 10 amino acids (QDLT-MKYQIF). The peptide was expressed in Escherichia coli with beta-galactosidase as a fused protein. There is no homology between the cloned sequence and other reported DNA sequences. Western blot analysis showed that the fused protein had specific binding to HuMAb L92. An antigen-encoding peptide with 10 amino acids was synthesized and tested for its immunoreactivity in vitro. HuMAb L92 reacted specifically to the 10-amino acid peptide in both an antibody-binding inhibition to the M(r) 43,000 protein and a solid-phase enzyme-linked immunosorbent assay. Using several truncated fusion proteins, we found the minimum number of amino acids required for the antibody binding to be 4 (KYQI). These results suggest that the identified peptide sequence encodes the antigenic epitope of the M(r) 43,000 protein.

Amino Acid Sequence↗