Biomedical subjects
H Okabe
Publications and source records attributed to H Okabe.
[The contribution of gastroscopy to radiographic diagnosis].
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[Plastic operations of cleft lip and palate].
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Complete left pericardial defect with dual passage of the phrenic nerve: a challenge to the widely accepted embryogenic theory.
We report a patient with complete left pericardial defect whose phrenic nerve, split into two portions, passes both ventral and dorsal to the defect. The dorsal part of the phrenic nerve passes over the ventral surface of the pulmonary artery and veins, indicating that the pericardio-pleural foramen has been obliterated. Contrary to the widely accepted embryogenic theory that pericardial defect results from persistence of the pericardiopleural foramen, we consider that the defect in this patient resulted from a tear in the pericardio-pleural membrane immediately lateral to the common cardinal vein.
Possible mild serotonin syndrome related to co-prescription of tandospirone and trazodone.
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Effects of somatostatin deficiency on cell distribution within the Langerhans islets.
Insulin, glucagon and somatostatin (SLI) in the pancreas and the gastrointestinal tissue of rats were measured following a high (300 mg/kg) or low (150 mg/kg) dose of cysteamine, given intermittently for 14 days. In addition, the effect of prolonged cysteamine-induced depletion of pancreatic SLI upon the cell distribution within the Langerhans islets was compared with that of chronic insulin-deficient rats produced by streptozotocin. The high or low dose of cysteamine reduced pancreatic SLI to 8.3% and gastrointestinal SLI to 5.6% of control levels without duodenal ulcer. The high dose of cysteamine also reduced pancreatic insulin to 37% of controls without hyperglycemia. No change in the glucagon concentration was observed. In SLI-deficient rats, distribution of A and B cells was similar to that of controls, even though D cells were rarely seen. In insulin-deficient rats, however, the number of A and D cells per islet area increased with a concomitant decrease in B cells. Intermittent administration of a low dose of cysteamine, thus, appears to be useful to produce a chronic SLI-deficient rat. However, a high dose of cysteamine is not a specific depletor of pancreatic SLI. Although insulin may be important to maintain normal cell distribution within the islets, pancreatic SLI may not have such a role.
Foci of signal intensities different from fat in well-differentiated liposarcoma and lipoma: correlation between MR and histological findings.
To investigate the histological features of foci, which showed signal intensities different from fat by magnetic resonance (MR) imagings in well-differentiated lipoma-like liposarcomas and a case of lipoma, a retrospective review of these lipomatous tumors was performed to correlate MR and histological findings. Microscopic findings revealed that these foci were also composed of lipomatous tissue. Well-differentiated liposarcoma and benign lipoma associated with such foci should be differentiated from dedifferentiated liposarcoma based on the histological findings.
Isolation of a novel human gene, MARKL1, homologous to MARK3 and its involvement in hepatocellular carcinogenesis.
Activation of the Wnt-signaling pathway is known to play a crucial role in carcinogenesis of various human organs including the colon, liver, prostate, and endometrium. To investigate the mechanisms underlying hepatocellular carcinogenesis, we attempted to identify genes regulated by beta-catenin/Tcf complex in a human hepatoma cell line, HepG2, in which an activated form of beta-catenin is expressed. By means of cDNA microarray, we isolated a novel human gene, termed MARKL1 (MAP/microtubule affinity-regulating kinase-like 1), whose expression was downregulated in response to decreased Tcf/LEF1 activity. The transcript expressed in liver consisted of 3529 nucleotides that contained an open reading frame of 2256 nucleotides, encoding 752 amino acids homologous to human MARK3 (MAP/microtubule affinity-regulating kinase 3). Expression levels of MARKL1 were markedly elevated in eight of nine HCCs in which nuclear accumulation of beta-catenin were observed, which may suggest that MARKL1 plays some role in hepatocellular carcinogenesis.
An infant with neuroblastoma and MYCN amplification found through mass screening.
PURPOSE: This report describes an extremely rare case of an infant with neuroblastoma involving MYCN amplification found through mass screening (MS). PATIENT: An 8-month-old boy was referred to our hospital after screening for neuroblastoma showed positive results. A firm tumor was found above his left kidney and completely resected. RESULTS: The tumor arose from the left adrenal gland. The disease was classified as stage I according to the International Neuroblastoma Staging System. Although the tumor showed a favorable histology, MYCN was amplified to 20 copies. After surgery, the infant underwent chemotherapy, but a new mass in the right adrenal gland was found. After chemotherapy, the tumor was excised. Despite several courses of chemotherapy, multiple metastases in both lung fields appeared. More intensive chemotherapy and allogenic peripheral blood stem cell transplantation were performed, but the infant died from pulmonary hemorrhage after the transplantation. CONCLUSIONS: The majority of patients with neuroblastoma found through MS have a good outcome. However, some patients have poor prognostic factors, like our patient with MYCN amplification. There is a need to develop a suitable protocol for babies with high risk features younger than 1 year of age found through MS.
Whole body oxygen consumption during extracorporeal hepatic resection: usefulness of continuous monitoring of mixed venous oxygen saturation.
Whole body oxygen consumption was measured using a thermodilution fibreoptic catheter in two patients undergoing extracorporeal hepatic resection. Each patient had virtually normal liver function before the operation. Anaesthesia was induced and maintained in a standard fashion and a venovenous bypass instituted. The anhepatic periods were 302 and 157 min. Upon removal of the liver, the oxygen consumption decreased by about 40% (50 mL/min), while the mixed venous oxygen saturation increased by about 15%. Following re-implantation, the oxygen consumption recovered and increased transiently above control values, while the mixed venous oxygen saturation changed in a reciprocal way. Monitoring whole body oxygen consumption instead of hepatic oxygen consumption seemed helpful in estimating restoration of blood flow and functions in the liver after reperfusion. It was also suggested that changes in oxygen consumption as well as those in cardiac output and haemoglobin concentration could be predicted easily by continuous monitoring of mixed venous oxygen saturation during the peri-anhepatic period.
The effects of dichloroacetate on liver damage and circulating fuels in rats exposed to carbon tetrachloride.
It has been known that carbon tetrachloride-induced liver damage in starved rats is ameliorated simply by restoration of feeding. An analogue of dichloroacetate has been reported to ameliorate carbon tetrachloride-induced liver damage, and dichloroacetate has been shown to have a variety of effects on fuel metabolism. We investigated simultaneously the effects of dichloroacetate on liver damage and on circulating fuels in rats exposed to carbon tetrachloride. The effects of carbon tetrachloride varied with the rat's condition. In starved rats, the liver damage was more severe, and serum ketone body concentration decreased. In non-starved rats, the liver damage was not as severe and the serum ketone body concentration increased. The administration of dichloroacetate ameliorated liver damage both in starved and in non-starved rats given carbon tetrachloride: the administration of dichloroacetate protected from the liver damage particularly in starved rats. There were associated changes in the concentrations of circulating fuels. When the pyruvate-lowering effect of dichloroacetate was diminished in carbon tetrachloride-injected, starved rats, the alanine aminotransferase-lowering effect of dichloroacetate was also diminished. We propose that dichloroacetate's effect on fuel metabolism may produce a hepato-protective effect.
Immunohistochemical investigation of thymidylate synthase in cervical cancer.
We prepared a polyclonal antibody against recombinant human thymidylate synthase (TS) to evaluate its use in immunohistochemical analysis. Formalin-fixed, paraffin-embedded sections of specimens of cervical tissue were prepared from 35 patients with cervical cancer. The TS immunoreactivity was studied by employing the peroxidase-labeled antibody method with our prepared antibody. At the same time, the TS activity was determined with the 5-fluoro-2'-deoxyuridylate (FdUMP)-TS-binding assay in fresh-frozen specimens of these cervical cancers. We observed a positive correlation (r = 0.658) between the degree of TS immunoreactivity and the TS activity in the binding assay of 9 patients with grade 4 (strongly positive) TS immunoreactivity, while 7 patients (78%) exhibited a TS activity of 5 pmol/g tissue or greater. Nine patients with a TS immunoreactivity of grade 1 (negative to weakly positive) showed a TS activity <5 pmol/g tissue. The difference between the two groups was statistically significant (p < 0.01). TS expression was easily detected by the immunohistochemical technique which will allow the assessment of the relationship between TS activity and patient outcome.
Effectiveness of coagulation factor XIII concentrate for reversing loss of tensile strength of rat intestinal anastomoses.
BACKGROUND: Blood coagulation factor XIII (F-XIII) promotes cross-linking of fibrin during blood coagulation. Impaired clot stabilization in patients with genetic deficiencies of F-XIII is associated with marked pathologies of wound healing. METHODS: 60 rats given carbon tetrachloride underwent ileal anastomosis after which they received albumin (Alb animals) or F-XIII concentrate (F-XIII animals) immediately after surgery and daily thereafter until day 2 or 4 and were euthanized on day 3 or 5, respectively, or until day 5 and were euthanized on day 7, 10, or 21. We measured the plasma F-XIII activity and anastomotic tensile strength, followed by immunohistochemical localization of F-XIII subunit A within anastomoses. RESULTS: On day 3, there were no significant differences between Alb and F-XIII animals for plasma F-XIII activity and tensile strength, and both groups of animals showed little immunostaining for F-XIII on anastomoses. Plasma F-XIII activities did not differ between Alb and F-XIII animals on day 5 (115.8 +/- 16.8 vs. 137.3 +/- 14.9%). Although the tensile strength in both groups was increased compared with that of day 3, that in F-XIII animals (129.8 +/- 3.3 gf) was significantly higher than that in Alb animals (100.8 +/- 5.3 gf, p = 0.014). F-XIII animals showed de novo collagen fibers and intense immunoreactivity of F-XIII in the extracellular matrix around the anastomoses. Similar differences occurred on day 7 but not days 10 and 21. CONCLUSIONS: F-XIII concentrate may accelerate the early healing process of intestinal anastomosis because of the protein's accumulation in situ.
Partial rupture of the quadriceps tendon (jumper's knee) in a ten-year-old boy. A case report.
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Sickle-tip sheath for percutaneous implantation of hepatic arterial catheter with subclavian arterial access.
We used a new type of sheath-introducer to facilitate the percutaneous procedure of hepatic arterial catheter implantation with left subclavian arterial access. Insertion into the descending aorta was easy without any additional catheters because the sheath could be manipulated to the aortic arch. After hepatic arterial catheterization, the sheath was slid safely away by fitting a 5 F catheter to the end of the indwelling catheter. The procedures of sheath insertion and removal were successful in all 29 cases, without any complications. The sickle-tip sheath is a useful optional device for trans-subclavian catheterization to the hepatic artery.
Thymidylate synthetase and dihydropyrimidine dehydrogenase levels in gastric cancer.
The measurement of thymidylate synthetase (TS) and dihydropyrimidine dehydrogenase (DPD) enzymatic activities and mRNA levels in tumors may be useful in predicting tumor sensitivity to 5-fluorouracil (5-FU). Forty-one patients with advanced gastric cancer gave informed consent and were enrolled in this study. Biopsy specimens of gastric cancer were obtained preoperatively through gastrofiberscopy and used to determine TS and DPD mRNA levels. We also measured TS and DPD enzymatic activities and mRNA levels in surgically resected gastric cancer samples, as well as in adjacent normal gastric mucosa. TS and DPD activities were measured using the TS-binding assay and a radioenzymatic assay, respectively, while mRNA levels were measured by semi-quantitative reverse transcription-PCR (RT-PCR) co-amplified with glyceraldehyde-3-phosphate dehydrogenase (GAPDH) as an internal standard. In resected tumor specimens, TS and DPD activities ranged from 7.1 to 176.6 fmol/mg protein and from 3.6 to 99.8 pmol/min/mg protein, respectively, while TS and DPD mRNA levels ranged from 0.50 to 21.12 and from 0.014 to 7:22, respectively. There were no significant correlations between TS/DPD levels and other clinicopathological factors, except for low DPD mRNA levels in undifferentiated carcinoma. Both TS activity and mRNA levels were significantly higher in tumor tissues compared to normal adjacent mucosa. In contrast, there was no significant difference between tumoral and non-tumoral DPD activity, although tumor tissue showed significantly lower DPD mRNA levels than non-tumoral tissue. High tumoral TS mRNA levels in preoperative biopsy specimens from patients with stage III/IV was associated with poor survival outcome after surgery compared with patients with low tumoral TS mRNA levels. In contrast, DPD levels had no influence on prognosis. We conclude that high tumoral TS levels and low tumoral DPD mRNA may indicate the selective cytotoxicity of 5-FU on gastric cancer, and that tumoral TS mRNA levels may be a prognostic factor for patients with stage III/IV gastric cancer.
Olfactory neuroepithelioma arising from the olfactory placode.
The patient was a 54-year-old man, who had lost his sense of smell 6 years previously and had started to become forgetful about 6 months prior to presenting at hospital. MRI admission showed a large multicystic tumor with Gd-DTPA enhancement extending from the anterior cranial fossa through the sphenoid sinus and into the nasal cavity. Histopathological examination revealed extensive proliferation of small round cells that were divided by connective tissue septae. The tumor cells occasionally formed tubular structures, although no basement membranes were present. On immunostaining, round tumor cells were positive for neuron-specific enolase, synaptophysin, and chromogranin A, while cells forming tubules were positive for AE 1 and CAM 5.2. Almost all of the tumor cells were positive for Ber-EP4, and some of the epithelioid cells surrounding the tubular structures were also positive for luteinizing hormone-releasing hormone (LH-RH). Electron microscopy demonstrated sporadic intercellular junctions, many microtubules in the tumor cell processes, and clear- and dense-cored vesicles in the cytoplasm. Based on the results, this case appears to be the first documented neuroepithelioma with Ber-EP4- and LH-RH-positive cells arising from the olfactory placode.
Cytologic detection of malignant lymphoma cells with a hairy appearance in ascitic fluid. Report of a case with immunofluorocytometric analysis.
Neoplastic lymphocytes with a hairy appearance were detected in the ascitic fluid from a case of retroperitoneal malignant lymphoma. Although the tumor cells resembled those of hairy-cell leukemia (HCL), no leukemic change was observed, and the anatomic location of the neoplastic cells was different from that seen in HCL. The tumor cells were positive for some immunohistochemical markers of HCL (i.e., CD1 9 and SIg) but were negative for others (CD11c, CD25 and tartrate-resistant acid phosphatase). Immunocytofluorometric and postmortem histologic studies showed the lesion to be a well-differentiated B-cell lymphocytic lymphoma with plasmocytic differentiation in some cells.