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Biomedical subjects

H Sakaguchi

Publications and source records attributed to H Sakaguchi.

At least 217 records · Page 12Linked to original sources
PubMed1995

Primary biliary cirrhosis complicated by severe hypoxemia.

The case reported here is of a 61-year-old woman diagnosed with hepatopulmonary syndrome. She had had severe hypoxemia for 5 years. In room air, her arterial oxygen tension was low, and although we anticipated that treatment with oxygen would increase it, the treatment failed to do so. Pulmonary perfusion imaging with Tc-99m-labelled macroaggregated albumin showed an arterio-venous shunt in the lungs. Blood tests and liver scanning with Tc-99m-labelled galactosyl human serum albumin showed abnormalities of liver function, and per-rectal portal scintigraphy with Tc-99m pertechnetate showed severe portal hypertension. Inspection of a biopsy specimen taken under ultrasonographic guidance showed primary biliary cirrhosis of Scheuer stage I. The causes of hepatopulmonary syndrome are unknown, but seem to include a decrease in hepatic functional reserve, portal hypertension, or other factors. The development of hepatopulmonary syndrome due to portal hypertension in this patient is of interest.

Biopsy↗
PubMed1995

Effect of warm ischemia and cryopreservation on cell viability of human allograft valves.

Fibroblast viability of the allograft valve leaflet has been suggested to affect clinical durability. Warm ischemic time is thought to be one of the critical determinants of cell viability. We assessed cell viability of allograft valves by flow cytometry, using a fluorescein diacetate-propidium iodide stain to characterize the effects of warm ischemia and cryopreservation on viability. Twelve human pulmonary valves with harvest-related warm ischemic times (range, 70 to 520 minutes; mean +/- standard deviation, 225 +/- 157 minutes) were studied by flow cytometry. We assessed cell viability of the allograft valve leaflets before and 30 days after storage. A significant negative correlation was found between warm ischemic time (x minutes) and cell viability (y%) before (y = -0.024x + 96.7; r2 = 0.62; p = 0.002) and after 30 days of storage (y = -0.036x + 94.0; r2 = 0.86; p = 0.001). Cell viability of the cryopreserved allograft valves was well preserved (> 70%) with a warm ischemic time less than 520 minutes (8.7 hours).

Adult↗
PubMed1995

Expression of the retinoblastoma gene product in human hepatocellular carcinoma.

Using the mouse anti-human retinoblastoma gene product (pRB) monoclonal antibody, PMG3-245, pRB was detected immunohistocytochemically in human hepatocellular carcinoma (HCC) tissues and a human HCC cell line, designated OCUH-16, recently established in our laboratory. This antibody reacted with human pRB and yielded a single band of approximately 110 kd from cultured OCUH-16 cells. The granules that stained for pRB were found mostly in the HCC cell nuclei, with a few granules observed in the rough endoplasmic reticulum by electron microscopy. Most of the stained granules were located in the euchromatin-rich areas. The percentage of OCUH-16 cells that expressed pRB or DNA polymerase alpha (DNA-PA) decreased over time as the number of OCUH-16 cells increased. The number of HCC cells that stained for pRB in the biopsy specimens from 11 patients varied and pRB expression was well maintained in early and advanced HCC. The level of pRB expression did not correlate with the differentiation of HCC cells or the clinical prognosis. The expression of pRB statistically correlated with that of DNA-PA (P < .01; r = .92). Some sinusoidal cells also stained for pRB. These findings imply that large deletions in the pRB gene are rare in the initiation or promotion of HCC. The correlation between pRB and DNA-PA may suggest that stained pRB participates in the proliferation of both HCC and non-HCC cells.

Adult↗
PubMed1995

Correlation between metastatic site, histological type, and serum tumor markers of gastric carcinoma.

Gastric carcinoma is classified into intestinal type carcinoma (IC) and diffuse type carcinoma (DC). Intestinal type carcinoma usually tends to metastasize to the liver and DC to the peritoneal cavity. However, discrepant cases are sometimes seen: IC with peritoneal metastasis or DC with liver metastatic site with special reference to these discrepant cases. We also studied the serum tumor markers (carcinoembryonic antigen [CEA] and carbohydrate antigen [CA] 19-9). We studied 124 autopsied specimens of patients who died of gastric carcinoma. The primary tumors were classified as IC or DC. The discrepant cases included 19 DCs with liver metastasis and 19 ICs with peritoneal dissemination. Most discrepant cases focally had histological features in the primary tumor consistent with our main supposition. On the other hand, discrepant foci were seen only very rarely in the primary tumor of cases with the corresponding usual metastatic site. The serum CEA levels of specimens from cases with liver metastases were higher than those without liver metastases. The serum CA 19-9 levels showed no significant correlation with the metastatic site of the carcinoma. In conclusion, in gastric carcinoma (1) the metastatic site was correlated with histological type (2) even in cases showing a discrepant metastatic site, focal areas of the histological type consistent with our main findings could be found in the primary tumor, and (3) serum CEA levels correlated with liver metastasis.

CA-19-9 Antigen↗
PubMed1995

Pancreaticoduodenal artery aneurysm: a case report and review of the literature.

A case of true pancreaticoduodenal artery (PDA) aneurysm is reported. A calcified lesion was initially detected by plain x-ray films, and an essential diagnosis was made before operation by intravenous digital subtraction angiography (IVDSA). Surgical resection of the aneurysm was performed successfully. Additionally, we reviewed a total of 82 cases with PDA aneurysm out of the 88 cases that had been reported in the English-language literature up to 1993. Fifty-three cases were accompanied by aneurysmal rupture (rupture group), and 29, including our case, were without rupture (nonrupture group). Because of the high mortality rate (49.1%) in the rupture group, a precise diagnosis and adequate treatment of PDA aneurysm before rupture is important. In the nonrupture group, a calcification on radiography appeared in 61.6% of the cases in which aneurysms were not found incidentally; this seems to be a significant indication for angiography. Moreover, intravenous digital subtraction angiography is quite useful for the screening of PDA aneurysm because it is an easy and noninvasive examination.

Aged↗
PubMed1995

Localization and characterization of a novel receptor for endothelin in the gills of the rainbow trout.

Endothelin (ET) receptors were identified in trout tissues that included the gill, heart, liver, kidney, and intestine. Since both the presence and the physiological function of endothelin-1 (ET-1) in trout gills have been determined, we examined the localization and characterization of ET receptors in the gills. Ligand specificity of the receptors, determined by using members of the endothelin family, revealed that endothelin receptors specific for ET-1 were predominant in the gills, but the binding sites of such receptors had low affinity for BQ-123, which is selective for mammalian endothelin A receptors (ETA). We propose that this subtype of receptor be called a fish-type ETA receptor (ETAF) to distinguish it from the mammalian ETA receptor. Affinity labeling of binding sites on gill membranes with 125I-labeled ET-1 and the cross-linking reagent 1,5-difluoro-2,4-dinitrobenzene revealed one major protein with an M(r) of 58,000, similar to that found in mammals. Autoradiographic studies demonstrated a high density of endothelin-binding sites in the lamellar sinusoid, which is involved in gas exchange in gills. No binding was detected in the chondrocytes or cartilaginous matrix. Our observations suggest that the endothelin and ET receptor system found in mammals might play a physiological role in the regulation of metabolic functions in fish.

Amino Acid Sequence↗
PubMed1995

Size-reduced cryopreserved pulmonary valve allograft for an RV-PA conduit: technical modification and functional evaluation.

Cryopreserved pulmonary allografts harvested from adults at the time of kidney donation were size reduced and used in two children with pulmonary atresia and ventricular septal defect. A technical modification for the creation of size-reduced pulmonary allograft conduits is described. Postoperative ultrasonic and cineangiographic assessments revealed excellent function of the pulmonary bicuspid valved conduit with a minimal pressure gradient and essentially no regurgitation. Although the long-term fate of cryopreserved bicuspid pulmonary valve and conduit is unknown, this conduit provides excellent handling characteristics that render allograft conduits preferable to synthetic conduits. In addition, the remodeled bicuspid pulmonary allograft conduits have exhibited excellent hemodynamic characteristics and are a reasonable alternative to other types of conduits when an appropriate size allograft is not available.

Adult↗
PubMed1995

Perichondrial localization of ETA receptor in rat tracheal and xiphoid cartilage and in fetal rat epiphysis.

Autoradiographic studies using 125I-labeled endothelin-1 (ET-1) on sections of rat cartilage tissues, including the trachea, xiphisternum, and fetal rat epiphysis, revealed dense localization of endothelin receptors in the perichondrium. In contrast, the binding of ET-1 was not detected in the chondrocytes, cartilage matrix, and other connective tissues of the cartilage tissues tested. The perichondrial binding of 125I-ET-1 was completely abolished with BQ-123 [an endothelin receptor subtype A (ETA) antagonist] but not with BQ-3020 (an ETB agonist), and we demonstrated the perichondrial localization of ETA receptors. [3H]thymidine incorporation in vitro was significantly increased in rat xiphoid cartilage tissues exposed to ET-1. These findings suggest that the ET-1/ETA receptor system plays an important role in regulating cartilage metabolism and endochondral bone formation.

Animals↗
PubMed1995

Mechanisms of the enhanced contractile response to a low concentration of phorbol 12,13-dibutyrate in thoracic aorta isolated from rats with dietary magnesium deficiency.

The mechanisms underlying the enhanced contractile response to phorbol 12,13-dibutyrate (PDBu) were examined in de-endothelialized thoracic aortas isolated from rats with dietary magnesium (Mg) deficiency. PDBu (1.0 nM)-induced contractions were significantly larger in Mg-deficient rats than in the controls. The contraction was completely inhibited by nifedipine, removal of external Ca2+ or by l-(5-isoquinolinesulfonyl)-2-methylpiperazine (H7). PDBu (1.0 nM) and phorbol 12-myristate 13-acetate (1.0 microM) significantly decreased the KD value and increased the Bmax for the binding of [3H]PN200-110 to the aortas. The degree of the decrease in the KD value was significantly greater in Mg-deficient rats than in the controls. The PDBu-induced decrease in the KD value was abolished by H7. These results suggest that activation of protein kinase C by phorbol esters may participate in the activation of L-type Ca2+ channels, which increases both the affinity of [3H]PN200-110 binding and the magnitude of the external Ca(2+)-dependent contraction. Dietary Mg-deficiency may enhance these processes.

Animals↗
PubMed1995

[Bupivacaine-fentanyl continuous infusion is superior to morphine bolus injection in postoperative epidural analgesia].

We compared bolus injection of morphine 51 +/- 9 micrograms.kg-1 (M-S group) with 48 h-continuous infusion of bupivacaine and fentanyl mixture (BF-C group) for postoperative epidural analgesia in 100 patients who had undergone upper abdominal laparotomy. The epidural analgesia was started about 60 min before completion of surgery. The mixed solution, consisting of bupivacaine 48 ml (240 mg), fentanyl 24 ml (1.2 mg) and 0.9% saline (24 ml), was administered at a rate of 2 ml.h-1 by using a 100 ml balloon infuser. Analgesic effects (determined by visual analogue scale, verbal pain scores at rest and with movement, additional requests of other analgesics), comfort and side effects of the epidural analgesia were examined. The evaluation based on postoperative analgesia and comfortable feeling rated higher in the BF-C group compared with the M-S group (P < 0.01 to of 0.05). There were fewer requests for other postoperative analgesics in the BF-C group (P < 0.01 to 0.05). There was no significant difference in side effects between the two groups. The plasma fentanyl concentration in the BF-C group (n = 5) was maintained almost constant for the period from 24 to 49 hours after the start of infusion and was approximately 1.6 ng.ml-1. We conclude that continuous infusion of bupivacaine (2.5 mg.ml-1) and fentanyl (12.5 micrograms.ml-1) at a rate of 2 ml.h-1 is superior to bolus injection of morphine for postoperative analgesia.

Adolescent↗
PubMed1994

Autocrine regulation of rat chondrocyte proliferation by natriuretic peptide C and its receptor, natriuretic peptide receptor-B.

Natriuretic peptide receptor-B (NPR-B) was identified in rat chondrocytes, and its physiological functions were investigated. Rat tissues, including the xiphoid cartilage, brain, lung, liver, adrenal gland, and kidney, were screened for NPR-B activity, which we assayed by receptor guanylate cyclase activity specifically stimulated by C-type natriuretic peptide (CNP), a known selective activator of NPR-B. Cartilage showed distinctly higher NPR-B activity. Furthermore, exposure of cultured rat chondrocytes to CNP (10(-6) M) resulted in a large increase in intracellular cGMP production (376 +/- 38 pmol/well), with threshold responses occurring between 10(-10) and 10(-9) M CNP. Atrial natriuretic peptide and brain natriuretic peptide also stimulated cGMP production in rat chondrocytes but with a potency that was at least 10 times less than that of CNP. Polymerase chain reaction analysis also demonstrated NPR-B gene expression in adult rat xiphisternum and cultured chondrocytes. These findings indicate that NPR-B is present in rat chondrocytes. In rat chondrocytes exposed to CNP, [3H]thymidine incorporation was inhibited in a dose-dependent manner (half-maximal response, 10(-11)M). However, much higher concentrations of atrial natriuretic peptide were required to induce the inhibition of thymidine incorporation. Interestingly, CNP-like immunoreactivity was detected in the conditioned medium from chondrocyte cultures. In addition, TGF-beta 1, a multifunctional cytokine, induced a marked increase in CNP secretion and CNP mRNA levels in chondrocytes. These results indicate that autocrine CNP inhibits mitogenesis in chondrocytes via NPR-B under the control of TGF-beta 1.

Animals↗
PubMed1994

Segmental transarterial chemoembolization with Lipiodol mixed with anticancer drugs for nonresectable hepatocellular carcinoma: follow-up CT and therapeutic results.

We developed segmental Lp-TAE, which is transcatheter hepatic sub-subsegmental, subsegmental, or segmental chemoembolization using Lipiodol introduced into the tumor-bearing hepatic sub-subsegment, subsegment, or segment as the target area. A total of 98 patients with nonresectable hepatocellular carcinoma (HCC) undergoing segmental Lp-TAE (Seg-Lp-TAE) were studied, and the relationship between the CT pattern observed after Seg-Lp-TAE (Seg-Lp-CT) and the therapeutic results obtained in those patients was evaluated. Seg-Lp-CT was classified into four types (type I, homogeneous; type II, defective; type III, inhomogeneous; and type IV, only slight accumulation, if any) according to the Lipiodol accumulation pattern observed after Seg-Lp-TAE. The cumulative nonrecurrence rates of type I were higher than those of types II-IV. The cumulative survival rates of type Ia, in which Lp accumulation is also seen around the main tumor, were the highest (93.8% at 1 year, 85.9% at 2 years, 85.9% at 3 years, and 57.3% at 4 years). The cumulative survival rates achieved with Seg-Lp-TAE were 89.2% at 1 year, 69.4% at 2 years, 58.9% at 3 years, 44.0% at 4 years, and 30.2% at 5 years, which were higher than those achieved with conventional Lp-TAE. Seg-Lp-TAE is very useful in the treatment of HCC limited to one sub-subsegment, subsegment, or segment, and it is important to choose sub-subsegmental, subsegmental, or segmental Lp-TAE on the basis of the size and site of the tumor as well as the type and the number of feeding arteries.

Adult↗
PubMed1994

Superficial spreading type extrahepatic bile duct cancer with lymphatic micrometastasis: report of a case.

We report herein the case of a 69-year-old woman with extrahepatic bile duct cancer which had developed superficially along the ductal mucosa without penetrating the fibromuscularis. She underwent a pancreatoduodenectomy; however, micrometastases were found histologically in the regional lymph nodes and she died with involved para-aortic lymph nodes and bone metastases 14 months after the operation.

Adenocarcinoma, Papillary↗