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Biomedical subjects

H Sakaguchi

Publications and source records attributed to H Sakaguchi.

At least 199 records · Page 11Linked to original sources
PubMed1996

Whole body autoradiography and microautoradiography in eels after intra-arterial administration of 125I-labeled eel ANP.

125I-labeled eel atrial natriuretic peptide (ANP) was administered into the ventral or dorsal aorta of freshwater (FW) and seawater (SW) eels, Anguilla japonica, and the major target organs were explored by whole body autoradiography. Localization of the ANP binding in the target organs was also examined at tissue and cell levels by microautoradiography using tissue sections. Whole body autoradiography revealed that the specific label was accumulated predominantly in the gill, with lesser amounts in the atrium, kidney, liver, and urinary bladder. Autoradiographic grains were most dense in the secondary lamellae of the gill, particularly on the side of the efferent filamental artery. Other binding sites in target tissues were the glomerulus of the kidney, epicardium and endocardium of the atrium, bile duct/blood vessels of the liver, and interrenal cells of the head kidney. There was no difference in the distribution and density of grains between injections into the ventral aorta and dorsal aorta, although, in the former, injected 125I-labeled eel ANP passes through the gill before reaching peripheral target tissues. There was a tendency for downregulation of ANP binding sites in SW eels, especially in the gill. These results show that specific ANP binding sites are present in organs that are implicated in osmoregulation and cardiovascular regulation in eels and further suggest that the number of ANP binding sites varies according to changes in the environmental salinity.

Anguilla↗
PubMed1996

Two cases of empty sella syndrome with variable dexamethasone-suppressibility of ACTH and cortisol.

We here describe two patients with empty sella syndrome who had variable and abnormal ACTH and cortisol secretory profiles. The patients are a 58-year old male and a 41-year old female, both of whom were neurotic. In both cases, low-dose dexamethasone suppression tests (1 mg, p.o., overnight) caused variable responses, such as a paradoxical increase, insufficient decrease or normal decrease in ACTH and cortisol depending on the period when they were performed. The circadian rhythm of ACTH and cortisol also showed variable patterns. Abdominal CT showed slight enlargement of both adrenal glands. Adrenal scintigraphy after dexamethasone suppression (3 mg, p.o., 7 days) revealed uptake into both adrenal glands. MRI of the brain indicated empty sella, but failed to show evidence of pituitary adenoma. It remains to be elucidated whether these secretory profiles of ACTH and cortisol in the two cases are only to be regarded as secondary changes associated with neurosis, as reported in depression or alcoholism, or the two cases share some pathogenetic mechanism with cyclic Cushing disease.

19-Iodocholesterol↗
PubMed1996

Human prohormone convertase 3 gene: exon-intron organization and molecular scanning for mutations in Japanese subjects with NIDDM.

Proinsulin is converted to insulin by the concerted action of two sequence-specific subtilisin-like proteases termed prohormone convertase 2 (PC2) and prohormone convertase 3 (PC3). PC3 is a type I proinsulin-processing enzyme that initiates the sequential processing of proinsulin to insulin by cleaving the proinsulin molecule on the COOH-terminal side of the dibasic peptide, Arg31-Arg32, joining the B-chain and C-peptide. Thus, PC3 plays a key role in regulating insulin biosynthesis. Expressions of insulin and PC3, but not PC2, are coordinately regulated by glucose, consistent with the important role of PC3 in regulating proinsulin processing. NIDDM is associated with increased secretion of proinsulin and proinsulin-like molecules, suggesting that mutations in the PC3 gene may be involved in the development of this disorder. To examine this hypothesis, we have isolated and characterized the human PC3 gene and screened it for mutations in a group of Japanese subjects with NIDDM. The PC3 gene consists of 14 exons spanning more than 35 kb. The exon-intron organization of PC2 and PC3 genes are conserved, consistent with a common evolutionary origin for the prohormone convertase gene family. Single-strand conformational analysis and nucleotide sequencing of the entire coding region of the PC3 gene in 102 Japanese subjects with NIDDM revealed missense mutations in exons 2 (Arg/Gln53) and 14 (Gln/Glu638), neither of which was associated with NIDDM in this population. These data suggest that genetic variation in the PC3 gene is unlikely to be a major contributor to NIDDM susceptibility in Japanese.

Animals↗
PubMed1996

[Chemoembolization therapy in small hepatocellular carcinoma].

As chemoembolotherapy (TAE) for relatively small hepatocellular carcinoma (HCC) including small HCC of less than 2 cm in diameter, which is restricted to a sub-subsegment, subsegment or segment of the liver, segmental Lp-TAE using Lipiodol (Lp) mixed with an anticancer agent, which includes subsegmental and sub-sub-segmental therapy, not restricted to the tumor-bearing segment, is expected to move to the forefront of HCC treatments and also causes fewer complications and less strain to the patient. Of the 15 cases that underwent surgery following segmental Lp-TAE, complete necrosis was found histopathologically in more than 80% of the main tumor, satellite nodules in the embolized region and areas of capsular invasion. Its therapeutic efficacy for 51 cases with tumors smaller than 3 cm was comparable to that of surgery.

Carcinoma, Hepatocellular↗
PubMed1996

[Color Doppler sonographic assessment of intrahepatic hemodynamics and shunt patency after transjugular intrahepatic portosystemic shunt (TIPS)].

The usefulness of color Doppler sonography for the assessment of intrahepatic hemodynamics and shunt patency was evaluated in a total of eight patients in whom the intrahepatic hemodynamics before and after transjugular intrahepatic portosystemic shunt (TIPS) could be serially examined by color Doppler sonography. In six of these patients the serial sonographic examinations could be followed for more than one year after TIPS creation. Within one month after TIPS creation, Vmax in the shunt was ranged from 87 cm/sec to 242 cm/sec (mean: 142.5 cm/ sec), and the flow direction in the right anterior portal vein was reversed in all patients. More than 70% stenosis of the shunt could be diagnosed by color Doppler sonography. When the shunt was confirmed by angiography to be more than 70% stenotic or occluded, Vmax in the shunt was decreased to less than 50 cm/sec and the blood flow in the right anterior portal vein become hepatopetal. From three months before stenosis or occlusion of the shunt, it was confirmed that Vmax in the shunt was less than 70 cm/sec or the blood flow of right anterior portal vein was hepatopetal. Color Doppler sonography was useful for the assessment of intrahepatic hemodynamics, and shunt patency and prediction of shunt stenosis or occlusion following TIPS creation.

Adult↗
PubMed1996

[Clinical evaluation of power Doppler sonography for the diagnosis of hepatocellular carcinoma].

We compared power Doppler sonography (PDS) with conventional color Doppler sonography (CDS) in the visualization of intratumoral blood flow of hepatocellular carcinoma (HCC) and evaluated the usefulness of PDS for assessing of the effects of TAE with Lipiodol and anticancer agents (Lp-TAE) and for the diagnosis of recurrence of HCC after Lp-TAE. The ability of PDS and CDS to visualize intratumoral blood flow was compared in 36 patients with HCC, and the usefulness of PDS for the diagnosis of HCC was evaluated. Also, in 17 patients with HCC who underwent Lp-TAE, the usefulness of PDS for evaluating the therapeutic effects of Lp-TAE and the diagnosis of recurrence after Lp-TAE was examined. The ability of PDS to visualize intratumoral blood flow and delineate tortuous and meandering intratumoral vasculature was superior to that of CDS. The effects of Lp-TAE could be evaluated and recurrence detected accurately and easily by PDS on the basis of residual intratumoral blood flow and the appearance of new blood flow. PDS is expected to achieve widespread acceptance as a useful imaging modality for the diagnosis of HCC, assessment of therapeutic effects of TAE, and detection of recurrence of HCC after TAE.

Carcinoma, Hepatocellular↗
PubMed1996

[Surgery for WPW syndrome with concomitant CABG: a case report].

A 58-year-old man underwent simultaneous surgery for WPW syndrome complicated by frequent attacks of atrial tachyarrhythmia combined with angina pectoris persisting after anterior myocardial infarction. Repeated PTCA of 3 times failed and restenosis occurred with recurrent angina particularly when atrial tachyarrhythmia took place. The preoperative ECG suggested the presence of a left free wall accessory pathway confirmed by an electro-physiolosical study. Coronary bypass grafting (LITA-LAD, SVG-4 PD) and division with cryoalation of the accessory pathway were performed using a transseptal left atrial approach. The patient is doing well now and free from both angina and tachycardia.

Angina Pectoris↗
PubMed1996

Cardiomyopathy associated with Graves' disease.

Cardiovascular changes associated with Graves' disease are generally considered to be secondary to the increased levels of thyroid hormone. We describe a case of Graves' disease in a 25-year-old man, who developed cardiomyopathy with severe heart failure. Pathological examination of the myocardial biopsies showed fibroblast infiltration and degenerative changes. After the cardiomyopathy subsided the patient developed a goitre and signs of hyperthyroidism, followed by Graves' ophthalmopathy, which was treated successfully with a combination of high-dose corticosteroids and orbital radiotherapy. These findings suggested a common pathogenesis for the cardiomyopathy and ophthalmopathy, and prompted us to investigate the expression of TSH receptor (TSH-R) in human heart. TSH-R mRNA was identified in human heart using the reverse transcriptasepolymerase chain reaction (RT-PCR) and DNA sequencing. Taken together, these data suggest that autoimmunity against the TSH-R might contribute to both the cardiomyopathy and ophthalmopathy in similar cases of Graves' disease.

Adult↗
PubMed1996

[Drug distribution of pelvic intraarterial infusion chemotherapy by bilateral internal iliac arterial catheter placement with coil occlusion of superior, inferior gluteal and obturator arteries].

The anticancer drug distribution in pelvic arterial infusion chemotherapy with bilateral internal iliac arterial catheter placement with coil occlusion of the superior, inferior and obturator arteries was indirectly evaluated by serially performed DSA, CTA and RI on 18 patients with pelvic malignancies. The distribution was judged to be Excellent (E), defined as uniform distribution in the entire lesion alone, in 9 of 18 patients (50%) evaluated prior to the start of the arterial infusion (AI), and as Good (G), defined as uniform distribution in the entire lesion and partly on an unaffected portion, in 9 (50%). Of the 11 patients evaluated after 7 times AI, E was found in 3 patients (27%), G in 7 (64%) and Fair (F), defined as distribution with a defect in the lesion, in one patient (9%). Of the 11 patients evaluated after 14 AI, E was found in 5 (45%), G in 4 (36%) and F in 2 (18%). Of the 7 patients evaluated after 21 AI, E was found in 2 (29%), G in 4 (57%) and F in one (14%). G was found in 2 of 2 patients (100%) evaluated after 28 AI. These results suggest that this method can maintain a favorable anticancer drug distribution even after multiple sessions of AI.

Adult↗
PubMed1996

Preservation of myocardial function and metabolism at subzero nonfreezing temperature storage of the heart.

BACKGROUND: The hypothermic simple immersion technique has been widely used to preserve the donor heart for transplantation. However, there is still controversy as to which temperature provides the best protection against prolonged ischemia. The low molecular weight solutes within cells depress the freezing point to -0.6 degree C. In practice, however, most cells do not freeze internally unless they are cooled below -10 degrees C. We investigated the effects of subzero nonfreezing storage at -1 degree C on the preservation of myocardial metabolism and function. METHODS: Isolated Wistar rat hearts were subjected to 6 hours of preservation with the intracellular type University of Wisconsin solution; the hearts of the subzero group were preserved at subzero nonfreezing (-1 degree C) temperature, and the hearts of the control group were at 4 degrees C. Recovery of cardiac function, myocardial adenine nucleotides content, and myocardial water content were evaluated after preservation. RESULTS: Subzero group resulted in significantly better aortic flow, cardiac output, and aortic systolic pressure than in the control group. Myocardial adenosine triphosphate, adenosine diphosphate, and total adenine nucleotides at end-storage were significantly better preserved in subzero group when compared with the control group. Myocardial water content at reperfusion significantly increased in the control group compared with the subzero group. CONCLUSIONS: Storage in the intracellular type solution at subzero nonfreezing (-1 degree C) temperature as compared with 4 degrees C appears to prolong myocardial preservation with respect to the enhancement of postischemic functional recovery, preservation of myocardial adenine nucleotides during ischemia, and prevention of myocardial edema at reperfusion.

Adenine Nucleotides↗
PubMed1995

Developmental changes in carbachol-stimulated phosphoinositide turnover in synaptoneurosomes of the robust nucleus of the archistriatum in the zebra finch.

The effects of acetylcholine (ACh) on synaptoneurosomes of the robust nucleus of the archistriatum (RA), one of the song control nuclei, were investigated during the sensitive period of song learning in the zebra finch. Carbachol (an ACh agonist) stimulated phosphoinositide (PI) turnover at three different ages. Corresponding to a marked increase in ACh levels in the RA, carbachol-stimulated PI turnover peaked during the most sensitive learning period in the life of the zebra finch. These findings suggest that ACh contributes to the regulation of synaptic plasticity in RA neurones involved with song learning in the zebra finch.

Analysis of Variance↗