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Biomedical subjects

K Okazaki

Publications and source records attributed to K Okazaki.

At least 91 records · Page 5Linked to original sources
PubMed2000

Sequence and structural diversity of the S locus genes from different lines with the same self-recognition specificities in Brassica oleracea.

Self-incompatibility (SI) is a mechanism for preventing self-fertilization in flowering plants. In Brassica, it is controlled by a single multi-allelic locus, S, and it is believed that two highly polymorphic genes in the S locus, SLG and SRK, play central roles in self-recognition in stigmas. SRK is a putative receptor protein kinase, whose extracellular domain exhibits high similarity to SLG. We analyzed two pairs of lines showing cross-incompatibility (S(2) and S(2-b); S(13) and S(13-b)). In S(2) and S(2-b), SRKs were more highly conserved than SLGs. This was also the case with S(13) and S(13-b). This suggests that the SRKs of different lines must be conserved for the lines to have the same self-recognition specificity. In particular, SLG(2-b) showed only 88. 5% identity to SLG(2), which is comparable to that between the SLGs of different S haplotypes, while SRK(2-b) showed 97.3% identity to SRK(2) in the S domain. These findings suggest that the SLGs in these S haplotypes are not important for self-recognition in SI.

Amino Acid Sequence↗
PubMed2000

Halothane attenuates the endothelial Ca2+ increase and vasorelaxation of vascular smooth muscle in the rat aorta.

Isolated spiral strips of rat thoracic aorta with endothelium were suspended for isometric tension recordings in a physiological salt solution. Endothelium-dependent vasorelaxation was elicited by carbachol 10(-6) and 10(-5) mol litre-1 during norepinephrine-induced contractions, and the effects of 1.5% and 3% halothane were evaluated with concomitant measurement of [Ca2+]i using fura-2-Ca2+ fluorescence. The effects of halothane on endothelium-dependent relaxation were compared with those of nitro G-L-arginine methyl ester 10(-4) mol litre-1 (L-NAME: an inhibitor of nitric oxide synthase). Carbachol reduced norepinephrine-induced contractions in a concentration-dependent manner, but augmented the norepinephrine-induced increase in [Ca2+]i in endothelium intact strips. In contrast, carbachol did not influence muscle tension or [Ca2+]i when the endothelium was completely denuded. Although 3% halothane and L-NAME 10(-4) mol litre-1 inhibited carbachol-induced vasorelaxation in a similar manner, halothane inhibited carbachol-induced increases in [Ca2+]i. These results indicate that halothane inhibited a carbachol-induced increase in [Ca2+]i in the endothelium, which subsequently attenuated the decrease in muscle tension.

Anesthetics, Inhalation↗
PubMed2000

Clinical analysis of autoimmune-related pancreatitis.

OBJECTIVE: Several investigators have reported on autoimmune-related pancreatitis, but the clinical findings and pathophysiology still remain unclear. To clarify it, we analyzed eight patients with autoimmune pancreatitis. METHODS: We evaluated clinical findings in eight patients (four men and four women) with autoimmune-related pancreatitis. Patients were aged 45-73 yr (mean, 57.5 yr). We examined blood chemistry and immunological studies, including autoantibodies against lactoferrin or carbonic anhydrase II, and compared ERCP images with clinical findings. In two patients, we studied the subset of lymphocytes infiltrating in the pancreas by immunohistochemistry and flow cytometry. RESULTS: Four of eight patients had jaundice, two had renal dysfunction, two had abdominal pain, and two had back pain. Three patients were complicated with other autoimmune diseases. Three patients showed abnormal pancreatic exocrine function by an N-benzoyl-L-tyrosyl-para-aminobenzoic acid excretion test. Antinuclear antibody was detected in four of eight patients, antilactoferrin antibody in three of six, anticarbonic anhydrase II antibody in two of six, antismooth muscle antibody in two of seven, and rheumatoid factor in one of eight. All eight patients showed segmental stenosis of the main pancreatic duct by ERCP. Four patients showed stenosis of the common bile duct as well as the pancreatic duct. Microscopic findings showed infiltration of CD4-positive lymphocytes around the pancreatic duct, and HLA-DR was expressed on both CD4-positive cells and pancreatic duct cells. In two patients, stenosis of the pancreatic duct improved by prednisolone. CONCLUSIONS: Autoimmune mechanism may be involved in some patients with idiopathic pancreatitis associated with hypergammaglobulinemia.

Aged↗
PubMed2000

Induction of follicular gastritis following postthymectomy autoimmune gastritis in Helicobacter pylori-infected BALB/c mice.

Helicobacter pylori is the major causative agent of chronic antral gastritis and is thought to be involved in the pathogenesis of mucosa-associated lymphoid tissue lymphoma (MALToma) developing in the human stomach. The aim of this study was to clarify whether corporal autoimmune gastritis (AIG), which is known to decrease acidity due to destruction of parietal cells, predisposes mice to H. pylori infection, thereby leading to MALToma-like pathology. BALB/c mice in which AIG had been induced by thymectomy 3 days after birth (AIG mice) were used. The AIG mice were orally administered mouse-adapted H. pylori at the age of 6 weeks and were examined histologically and serologically after 2 to 12 months. The results were compared with those obtained from uninfected AIG mice and infected normal mice. Germinal centers were induced in the corpus in 57% of the H. pylori-infected AIG mice, which elicited anti-H. pylori antibody responses in association with upregulation of interleukin-4 (IL-4) mRNA. In these mice, parietal cells remained in the corpus mucosa. These findings were in contrast to those with the uninfected AIG mice: fundic gland atrophy due to disappearance of parietal cells associated with upregulation of gamma interferon, but not IL-4, mRNA and no germinal center formation in the corpus. These observations suggest that AIG alters the infectivity of H. pylori, leading to MALToma-like follicular gastritis, at an early stage after H. pylori infection.

Animals↗
PubMed2000

Two cases of acute myositis associated with influenza A virus infection in the elderly.

During the influenza epidemic of 1998-1999, we observed two elderly patients with influenza-like symptoms who had evidence of acute myositis with elevated serum enzymes. Influenza A infection was confirmed serologically in either case. The present cases suggest that it is important to distinguish influenzal myositis from other forms of myopathy in the elderly patients.

Acute Disease↗
PubMed2000

Endoscopic resection of small inflammatory fibroid polyp of the colon.

Inflammatory fibroid polyp (IFP) is a solitary intestinal lesion of unknown etiology. Although IFP is benign, laparotomy for the resection of colonic IFP is performed in most cases because the polyp is usually large. We report a successful endoscopic resection of cecal IFP. It is considered that colonic IFP should be resected endoscopically if the polyp is small and is located submucosally.

Colonic Polyps↗
PubMed2000

Establishment of a human colon cancer cell line (PMF-ko14) displaying highly metastatic activity.

A new human colon cancer cell line (PMF-ko14) derived from a peritoneal disseminated tumor has been established and maintained for over 25 months. In tissue culture, the cells grew in a mainly monolayered sheet with a population doubling time of about 27 h. Chromosome counts at the 60th passage ranged from 79 to 84 with a modal number of 83. Flow cytometry of the cell surface antigen expression indicated that CD49b, CD29, carcinoembryonic antigen (CEA), sialyl Lewis a (sLea), and CD49c were positive in more than 70% of the cells. The nude mouse xenograft models indicated are: subcutaneous or intraperitoneal injection model, spleen injection-liver metastasis model, and orthotopic implantation-spontaneous metastasis model. As PMF-ko14 has highly metastatic activity it should prove to be a useful tool for research in biological behavior of metastatic colon cancer.

Animals↗
PubMed2000

Development of an oral drug delivery system targeting immune-regulating cells in experimental inflammatory bowel disease: a new therapeutic strategy.

Several studies have indicated the involvement of macrophages and dendritic cells in active inflammatory bowel disease (IBD). Manipulation of these cells is considered a very important therapeutic strategy for patients with IBD. We evaluated the effect of a new drug delivery system targeting microfold cells and macrophages with poly(DL-lactic acid) microspheres containing dexamethasone (Dx). Colitis was induced in BALB/c mice by 5% dextran sodium sulfate. Dx microspheres (n = 10) and only Dx (n = 10) were orally administered to dextran sodium sulfate-treated mice. Thereafter, serum levels and tissue distributions of Dx were investigated. To estimate the efficacy of this drug delivery system, we measured the histological score, myeloperoxidase activity and nitric oxide production, and gene expressions of tumor necrosis factor-alpha, interleukin-1beta, and interferon-gamma in the colonic tissue. Serum Dx levels were not increased after oral administration of Dx microspheres. The tissue distribution of microspheres containing (125)I-labeled Dx in inflamed colon was significantly higher than in other organs. The histological score, myeloperoxidase activity, and nitric oxide production of the group treated with Dx microspheres were significantly lower than of those treated with Dx alone. Gene expressions of tumor necrosis factor-alpha, interleukin-1beta, and interferon-gamma were down-regulated in mice treated with Dx microspheres. Microspheres containing glucocorticoids such as Dx, which target microfold cells and macrophages, can facilitate mucosal repair in experimental colitis and could be an ideal agent for treatment of human IBD.

Administration, Oral↗
PubMed2000

Expression of ciliary neurotrophic factor activated by retinal Müller cells in eyes with NMDA- and kainic acid-induced neuronal death.

PURPOSE: To elucidate the role of retinal Muller cells in N-methyl-D-aspartate (NMDA)- or kainic acid (KA)induced retinal damage. METHODS: In experimental eyes, NMDA or KA was injected into the vitreous of rat eyes. Immunohistochemistry and western blot analysis were conducted to elucidate expression and localization of glial fibrillary acidic protein (GFAP) and ciliary neurotrophic factor (CNTF). In addition, the neuroprotective effects of CNTF were calculated by counting cells in the ganglion cell layer (GCL) and by measuring the thickness of the various retinal layers. RESULTS: Morphometric analysis of retinal damage in NMDA- and KA-injected eyes showed significant cell loss in the GCL and thinning of the inner plexiform layer (IPL) of the retina, but not of other retinal layers. Immunohistochemistry demonstrated disappearance and/or decrease in immunoreactivities of calbindin- and calretinin- positive cells and their neurites and upregulated expression of both GFAP and CNTF in experimental eyes. Western blot analysis showed an increase in protein expression for CNTF in retinas of experimental eyes. Confocal images and sequential localization demonstrated colocalization of CNTF and GFAP in the inner retinal layer and possibly in Muller cells. In addition, pretreatment with CNTF (1 microg) before the intravitreal injection of NMDA (or KA) demonstrated that CNTF has neuroprotective effects against NMDA- or KA-induced neuronal death in the retina. CONCLUSIONS: These studies revealed the upregulated expression of CNTF and GFAP in Muller cells in response to NMDA- and KA-induced neuronal death, suggesting that production of CNTF in Muller cells may be a part of the endogenous neuroprotective system in the retina.

Animals↗
PubMed2000

Pyogenic arthritis of a lumbar facet joint.

We herein report the case of a 68-year-old man with diabetes who developed pyogenic arthritis of a lumbar facet joint after spinal injection. We performed magnetic resonance imaging (MRI), computed tomography (CT), technetium 99 methylene diphosphonate scintigraphy, and single photon emission computed tomography (SPECT) for this patient. MRI showed a lesion in the facet joint and no evidence of spondylodiscitis. CT showed a swelling of periarticular soft tissue around the facet joint. Bone scintigraphy showed a characteristic vertical uptake. In particular, SPECT was able to clearly confirm the location of the infection. An infection of the facet joint has only been rarely reported, but we recommended that this area should be carefully evaluated whenever a patient develops an infection of the lumbar spine after a spinal injection.

Aged↗
PubMed2000

[Continuous monitoring of hemoglobin oxygen saturation of the hepatic vein in patients undergoing laparoscopic cholecystectomy].

We monitored of hemoglobin oxygen saturation of the hepatic vein (ShvO2) continuously in 6 patients undergoing laparoscopic cholecystectomy under inhalation anesthesia only, and in 6 patients under combined epidural and inhalation anesthesia. In inhalation anesthesia only group, arterial blood pressure increased and ShvO2 values decreased immediately after intraperitoneal insufflation with CO2, demonstrating the mean lowest ShvO2 value of 25 percent. In combined anesthesia group, arterial blood pressure and ShvO2 values were unchanged after the intraperitoneal insufflation compared with values obtained before the insufflation. The results indicate that hepatic blood flow may be better preserved with combined epidural and inhalation anesthesia than with inhalation anesthesia only, suggesting that sympathetic block by epidural anesthesia may contribute to this favorable effect on ShvO2.

Adult↗
PubMed2000

[A case of gastric cancer with multiple liver metastasis responding to combined chemotherapy with low-dose cisplatin and 5-fluorouracil].

A 68-year-old man who had Borrmann type 4 gastric cancer with multiple liver metastases was admitted to our hospital on October 20, 1998. He was considered nonresectable and placed on neoadjuvant chemotherapy consisting of low-dose CDDP and 5-FU. After 9 weeks of administration, the liver metastases had disappeared on abdominal computed tomography, but the primary lesion had progressed. On May 12, 1999, a total gastrectomy with a partial resection of the transverse colon and resectional biopsy of a white nodule of the liver were performed. This was a non-curative operation because of the peritoneal dissemination. A histopathological examination of the liver nodule revealed that the cancer cells had disappeared. The patient had an uneventful postoperative course and 4 weeks of chemotherapy were added. He remains alive with no symptoms or re-growth of the liver metastatic tumor 4 months after the surgery.

Adenocarcinoma↗
PubMed2000

Gross and microscopic anatomy of the extraorbital lacrimal gland of the common marmoset (Callithrix jacchus).

PURPOSE: The lacrimal gland is often selected for microscopic examination in toxicologic studies. However, this gland is difficult to find within the orbit in marmosets at necropsy. Therefore, we examined the extraorbital lacrimal glands in marmosets. METHODS: The formalin-fixed craniums of four marmosets were used in a topographic study to confirm location of the lacrimal gland, and the results were applied to a routine toxicologic study in marmosets. RESULTS: The extraorbital lacrimal gland was located on the temporal surface of the zygomaticofrontal process and was covered with the temporalis muscle. The gland was easily detached from the surrounding tissue, and its histologic features were the same as those of the intraorbital lacrimal gland. CONCLUSIONS: The extraorbital lacrimal glands have been reported in some New World monkeys, but to the authors' knowledge, this is the first report in marmosets. Identification and characterization of this gland will be useful for toxicologic studies in marmosets.

Animals↗