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Biomedical subjects

T Eto

Publications and source records attributed to T Eto.

At least 235 records · Page 13Linked to original sources
PubMed1994

Induction of extrahepatic biliary carcinoma by N-nitrosobis(2-oxopropyl)amine in hamsters given cholecystoduodenostomy with dissection of the common duct.

The methods we used to produce a carcinoma in the extrahepatic bile duct and gallbladder in hamsters are described along with the characteristics of the induced tumors. Female Syrian golden hamsters were first subjected to cholecystoduodenostomy with dissection of the extrahepatic bile duct on the distal end of the common duct (CDDB) and were, 4 weeks later, treated with weekly subcutaneous injections of N-nitrosobis(2-oxopropyl)amine (BOP) at a dose of 10 mg/kg body weight for 9 weeks. The animals were killed at the 12th, 16th and 20th week after the initiation of BOP treatment. Extrahepatic bile duct carcinoma developed in 16%, 24% and 41% and gallbladder carcinoma occurred in 58%, 81% and 82% of the hamsters, respectively, at the corresponding times of killing. The incidences were significantly higher than those in sham-operated controls (P < 0.01). The induced extrahepatic bile duct carcinomas were predominantly of the polypoid type and gallbladder carcinomas were of the papillary type in growth form, being morphologically similar to early stage biliary carcinoma in humans. Immunohistochemical staining using bromodeoxyuridine and anti-bromodeoxyuridine monoclonal antibody demonstrated that the CDDB procedure greatly accelerated the cell kinetic activity of the biliary epithelium, and this was considered to be a major factor promoting the development of biliary carcinomas in this hamster model. In conclusion, this new model provides a high incidence of tumor development at the extrahepatic biliary tract and is expected to be useful for clarifying the characteristics of this highly malignant tumor.

Animals↗
PubMed1994

Clinical studies on the sites of production and clearance of circulating adrenomedullin in human subjects.

Adrenomedullin is a novel hypotensive peptide, newly discovered in pheochromocytoma. Because immunoreactive adrenomedullin is present in human plasma, adrenomedullin may play a role in regulating blood pressure. A recent report showed that human adrenomedullin mRNA is expressed not only in pheochromocytoma but also in the normal adrenal medulla, kidney, lung, and ventricle. However, whether or not these organs actually release adrenomedullin into the circulation remains unknown. To investigate the sites of production and degradation of adrenomedullin in human subjects, we obtained blood samples from various sites and measured immunoreactive adrenomedullin concentrations. In study 1, blood samples were obtained from the infrarenal inferior vena cava, suprarenal inferior vena cava, superior vena cava, right atrium, right ventricle, pulmonary artery, pulmonary capillary, left ventricle, and aorta during cardiac catheterization in 15 patients with ischemic heart disease (67 +/- 10 years). In study 2, blood samples were taken from the infrarenal inferior vena cava, suprarenal inferior vena cava, right and left renal veins, and left adrenal vein in 5 hypertensive patients (42 +/- 14 years) suspected of having renovascular hypertension. In study 3, peripheral venous blood samples were obtained in 2 patients (males, 45 and 36 years old) with pheochromocytoma at rest and during hypertensive attacks. Plasma adrenomedullin concentrations were measured by a newly developed radioimmunoassay. In study 1, there were no significant differences in plasma adrenomedullin concentrations in various sites of the right-side circulation. There was no step-up of plasma adrenomedullin levels in the coronary sinus. However, the plasma concentration of adrenomedullin in aorta was slightly but significantly lower than in pulmonary artery.(ABSTRACT TRUNCATED AT 250 WORDS)

Adrenal Gland Neoplasms↗
PubMed1994

Plasma levels of adrenomedullin, a newly identified hypotensive peptide, in patients with hypertension and renal failure.

Adrenomedullin is a potent hypotensive peptide newly discovered in pheochromocytoma tissue by monitoring its elevating activity on platelet cAMP. We measured plasma concentration of adrenomedullin in patients with essential hypertension and chronic renal failure. As compared with normal subjects, plasma adrenomedullin was increased by 26% (P < 0.05) in hypertensives without organ damage and by 45% (P < 0.005) in those with organ damage. The increase in plasma adrenomedullin was more prominent in renal failure than in hypertension. Renal failure patients with plasma creatinine of 1.5-3, 3-6, and > 6 mg/dl had higher plasma adrenomedullin levels than healthy subjects by 78% (P < 0.05), 131% (P < 0.001), and 214% (P < 0.001), respectively. Moreover, adrenomedullin showed intimate correlations with norepinephrine, atrial natriuretic peptide, and cAMP in plasma (r = 0.625, P < 0.001; r = 0.656, P < 0.001; and r = 0.462, P < 0.001; respectively). Thus, plasma adrenomedullin is supposed to increase in association with changes in sympathetic nervous activity and body fluid volume in hypertension and renal failure. Considering its potent vasodilator effect, adrenomedullin may be involved in the defense mechanism preserving the integrity of the cardiovascular system in these disorders.

Adrenomedullin↗
PubMed1994

Endoscopic ultrasonography using a 15/20 MHz probe in a direct contact technique: evaluation and application in esophageal and gastric varices.

Endoscopic ultrasonography (EUS) has been recently developed as a new diagnostic technique for portal hypertension. However, its conventional water-filled balloon technique is not suitable for the evaluation of esophageal varices, because the vessel lumen is compressed by the inflated balloon. Particularly for small varices, the vessel tends to collapse and is difficult to display. A miniature ultrasonic probe for use via the forceps channel in EUS has been developed and is expected to overcome this difficulty. Here we report the efficacy of this new probe in patients with esophago-gastric varices. Instead of using a water-filled balloon for an acoustic window, we displayed the EUS findings from the new probe in direct contact with gastrointestinal wall by removing air from the lumen under vacuum. Both conventional endoscopy and the new EUS were performed on 3 patients with esophageal varices. The transforceps-channel ultrasonic probe visualized grade 1 varices in addition to the larger varices, confirming this technique to be a useful method for assessing of esophageal varices. Moreover, this method does not require a specially designed endoscope for EUS, rather it can be employed in combination with conventional endoscopy. We conclude that this new technique is a preferred diagnostic technique, and it should become more widely accepted for routine clinical applications.

Aged↗
PubMed1994

Small bowel tumors: an analysis of tumor-like lesions, benign and malignant neoplasms.

The clinical records of 72 patients with 73 small bowel tumors diagnosed over a period of 25 years were reviewed. The tumors consisted of 23 tumor-like lesions, 17 benign neoplasms and 33 malignant neoplasms, the mean size of which were 2.1 cm, 5.2 cm and 7.7 cm in diameter, respectively. The tumor-like lesions and benign neoplasms were found even in children, while the malignant neoplasms were observed in patients 43 years old or over. The most common tumor-like lesion was aberrant pancreatic tissue. The common benign neoplasms were leiomyoma, lipoma and adenoma. The malignant neoplasms consisted of adenocarcinoma, malignant lymphoma and leiomyosarcoma. Regardless of tumor type or tumor location, the lesions 4 cm or larger often caused abdominal symptoms. Most of the lesions less than 4 cm caused no symptoms, but the malignant lesions of this size in the ileum elicited abdominal symptoms in all patients. The presence of lesions was diagnosed preoperatively in 26.1% of patients with tumor-like lesions, 47.1% with benign neoplasms and 48.5% with malignant neoplasms. Resection was performed in all but one patient with tumor-like lesions and benign neoplasms. Among malignant lesions, the resectability rate was 80.0% for adenocarcinoma and 100% for both malignant lymphoma and leiomyosarcoma. However, the patients with malignant lesions showed a poor prognosis. In conclusion, it is important to recognize small bowel tumors--especially malignant lesions--as a rare but possible cause of abdominal symptoms and thereby to contribute to the early detection and successful management of small bowel tumors.

Adenocarcinoma↗
PubMed1994

Biliary diverticulum with pancreaticobiliary maljunction.

The case of a 48-year-old Japanese man with a biliary diverticulum (type B by the so-called Alonso-Lej classification) accompanied by pancreaticobiliary maljunction is reported on herein. The patient had epigastric distress, and an ultrasound examination suggested gallstones and adenomyomatosis of the gallbladder. Subsequent endoscopic retrograde cholangiopancreaticography demonstrated a 3 mm biliary diverticulum in the intrahepatic bile duct and pancreaticobiliary maljunction. Intra-operative cholangiography confirmed both the diverticulum and the pancreatiocobiliary maljunction. Cholecystectomy alone was performed. The histological diagnosis of the gallbladder was adenomyomatosis with intramural calculi. Except for continuing mild hyperamylasemia, the patient has been doing well for 18 months following surgery. To our knowledge, only two cases, of type B bile duct dilatation with pancreaticobiliary maljunction, including ours, have been reported in the English and Japanese literature. The size of the diverticulum in our case was smaller than in the other reported case. The relationship between pancreaticobiliary maljunction and type B bile duct dilatation is discussed.

Adenomyoma↗
PubMed1994

Effects of macrophage colony-stimulating factor (M-CSF) on the mobilization of peripheral blood stem cells.

We studied the effects of human urinary macrophage colony-stimulating factor (huM-CSF) on the mobilization of peripheral blood stem cells (PBSC) following cytotoxic chemotherapy in 6 patients with acute leukemia. After complete remission (CR) was achieved, two courses of consolidation chemotherapy consisting of an intermediate dose of cytosine arabinoside were administered to the patients. During a recovery phase after each course of consolidation chemotherapy, two successive cycles of leukapheresis were performed every other day. M-CSF was administered intravenously at a dose of 8 x 10(6) U/day during a recovery phase after the second course of consolidation chemotherapy (cytotoxic plus M-CSF mobilization). There was no significant difference in white blood cell (WBC) or platelet recovery between the first and second cycles, regardless of the administration of M-CSF. Furthermore, between cytotoxic and cytotoxic/M-CSF mobilization, significant differences were not observed in the harvest of mononuclear cells (average 1.43 x 10(8)/kg vs 1.62 x 10(8)/kg), granulocyte/macrophage progenitor cells (CFU-GM) (1.82 x 10(4)/kg vs 3.07 x 10(4)/kg) or erythroid progenitor cells (BFU-E) (2.86 x 10(4)/kg vs 2.66 x 10(4)/kg). Thus M-CSF is not effective for expanding a pool of circulating hematopoietic stem cells when administered at a conventional dose during hematologic recovery following chemotherapy.

Acute Disease↗
PubMed1993

Hematopoietic progenitor cells from patients with adult T-cell leukemia-lymphoma are not infected with human T-cell leukemia virus type 1.

The in vivo host range of human T-cell leukemia virus type 1 (HTLV-1) has not been definitively established. To determine if hematopoietic stem cells from patients with adult T-cell leukemia-lymphoma (ATL) are infected with HTLV-1, we used a clonogenic progenitor assay followed by the polymerase chain reaction for the detection of HTLV-1 DNA. In vitro growth characteristics of myeloid (CFU-GM) and erythroid (BFU-E) progenitor cells among nonadherent T-cell-depleted bone marrow (BM) mononuclear cells (NA-T-MNCs) from 10 patients with ATL was not significantly different from those of HTLV-1-seronegative controls (P = .20); numbers of colonies per 1 x 10(5) NA-T-MNCs were 34.9 +/- 7.6 for CFU-GM and 39.0 +/- 12.5 for BFU-E in patients with ATL, whereas those were 32.1 +/- 9.5 for CFU-GM and 41.4 +/- 12.7 for BFU-E in normal controls. HTLV-1 DNA was not detected in individual colonies formed by CD34+ cells from any of the patients. Similarly HTLV-1 DNA was not detected in 1 x 10(3) CD34+ cells sorted on a fluorescence-activated cell sorter (FACS) from six patients with ATL studied. In contrast, HTLV-1 DNA was detected in BM mononuclear cells from all patients. These observations clearly indicate that hematopoietic progenitor cells from patients with ATL are normal in their colony-forming capacity and that CD34+ cells from patients with ATL are not infected with HTLV-1 in vivo.

Adult↗
PubMed1993

Vasodilator effect of adrenomedullin and calcitonin gene-related peptide receptors in rat mesenteric vascular beds.

The effect of adrenomedullin, a novel peptide of 52 amino acids, on vascular tone was investigated in the perfused rat mesenteric vascular bed. In the vasculature contracted with methoxamine, perfusion of adrenomedullin (10(-11)-10(-7) M) caused a concentration-dependent decrease in perfusion pressure due to vasodilation. Additionally, a bolus infusion of adrenomedullin (300 and 500 pmol) produced a long-lasting vasodilator response, which was not affected in the presence of atropine (10(-7) M) and propranolol (10(-7) M). However, this response was inhibited in the presence of CGRP [8-37] (10(-6) M), an antagonist for CGRP receptor. These results suggest that adrenomedullin induces nonadrenergic and noncholinergic vasodilation in which CGRP receptors may be involved.

Adrenomedullin↗
PubMed1993

Molecular cloning and biological activities of rat adrenomedullin, a hypotensive peptide.

Adrenomedullin is a new hypotensive peptide recently identified in human pheochromocytoma arising from adrenal medulla. We report here the cDNA encoding a rat adrenomedullin precursor. The precursor is 185 amino acids in length, including a 21 residue putative signal peptide at the N-terminus. Rat adrenomedullin consists of 50 amino acids similar to, but distinct from human adrenomedullin; 2 residues were deleted and 6 residues were substituted compared to those in the human peptide. In the proadrenomedullin N-terminal 20 peptide, whose amino acid sequence is present in adrenomedullin precursor, 3 amino acids were substituted. RNA blot analysis showed that rat adrenomedullin mRNA was expressed in adrenal glands, lung, kidney, heart, spleen, duodenum and submandibular glands. Synthetic rat adrenomedullin elicits a potent and long-lasting hypotensive activity in anesthetized rats.

Adrenal Glands↗
PubMed1993

Hemodynamic effects of a novel hypotensive peptide, human adrenomedullin, in rats.

The hemodynamic effects of human adrenomedullin were investigated in anesthetized Wistar rats. Intravenous administration of adrenomedullin (1.0 nmol/kg) caused a rapid and marked reduction in mean blood pressure associated with a decrease in total peripheral resistance. This reduction in mean blood pressure was closely correlated with the decrease in total peripheral resistance. These findings indicate that human adrenomedullin is a potent vasodilator and may have some role in the regulation of blood pressure.

Adrenomedullin↗
PubMed1993

Cloning and characterization of cDNA encoding a precursor for human adrenomedullin.

Adrenomedullin is a novel hypotensive peptide recently isolated from human pheochromocytoma. Since a high concentration of immunoreactive adrenomedullin was found in pheochromocytoma tissue, the cDNA library of pheochromocytoma was constructed, and the cDNA clone encoding an adrenomedullin precursor was isolated and sequenced. The precursor for human adrenomedullin (human preproadrenomedullin) is 185 amino acids in length, including an adrenomedullin sequence. Proadrenomedullin (proAM) contains a unique twenty amino acid sequence followed by Gly-Lys-Arg in the N-terminal region. It is possible that a novel 20 residues peptide, termed "proadrenomedullin N-terminal 20 peptide" (proAM-N20) whose carboxy terminus may be Arg-NH2, is processed from proadrenomedullin. By RNA blot analysis, human adrenomedullin mRNA was found to be highly expressed in several tissues including adrenal medulla, ventricle, lung and kidney as well as pheochromocytoma.

Adrenal Gland Neoplasms↗
PubMed1993

Adrenomedullin: a novel hypotensive peptide isolated from human pheochromocytoma.

A novel hypotensive peptide was discovered in human pheochromocytoma by monitoring the elevating activity of platelet cAMP. Since this peptide is abundant in normal adrenal medulla as well as in pheochromocytoma tissue arising from adrenal medulla, it was designated "adrenomedullin". The peptide, consisting of 52 amino acids, has one intramolecular disulfide bond and shows slight homology with calcitonin gene related peptide. It was found to elicit a potent and long lasting hypotensive effect. The peptide circulates in blood in a considerable concentration, but it was not found in brain. These data suggest that adrenomedullin is a new hormone participating in blood pressure control. Occurrence of adrenomedullin indicates the possible existence of a novel system for circulation control.

Adrenal Gland Neoplasms↗
PubMed1993

Dimeric form of calcitonin gene-related peptide in the porcine thyroid gland.

In this study we investigated peptides that increase rat platelet cAMP in porcine thyroid gland. Gel filtration of extracts from porcine thyroid gland showed high and low molecular weight activity. Low molecular weight activity contained peptides, including calcitonin gene-related peptide (CGRP), vasoactive intestinal polypeptide (VIP) and peptide histidine isoleucine (PHI). We isolated a high molecular weight peptide (M. W. 11,000) showing potent activity able to increase rat platelet cAMP in porcine thyroid gland. The peptide's N-terminal sequence was determined to be Ser-X-Asn-Thr-Ala-Thr- by gas phase sequencer analysis, a sequence identical to that of porcine CGRP. The peptide had CGRP immunoreactivity as well as platelet cAMP elevating activity. By gel filtration HPLC, synthetic human CGRP (M. W. 3790) was eluted in a position corresponding to M. W. 5,500. These results suggest that judging from its high molecular weight the above peptide is a dimeric form of CGRP.

Amino Acid Sequence↗
PubMed1993

Sclerosing encapsulating peritonitis combined with peritoneal encapsulation.

The combined occurrence of idiopathic sclerosing encapsulating peritonitis and peritoneal encapsulation is described. A 52-year-old man presented with intestinal obstruction. The results of preoperative examinations were suggestive of sclerosing encapsulating peritonitis. Laparotomy revealed the concurrence of peritoneal encapsulation and sclerosing encapsulating peritonitis. The thick membrane of sclerosing encapsulating peritonitis was freed with multiple incisions. After operation, the patient reverted to the preoperative state. The condition, however, was alleviated with conservative therapy consisting of intravenous hyperalimentation and nasogastric suction. To our knowledge, the combined occurrence of sclerosing encapsulating peritonitis and peritoneal encapsulation has never before been reported.

Collagen↗
PubMed1993

A case of intracystic carcinoma of the breast: the importance of measuring carcinoembryonic antigen in aspirated cystic fluid.

We report a case of intracystic carcinoma of the breast in which a correct preoperative diagnosis was achieved on the basis of an increased level of carcinoembryonic antigen (CEA) in the aspirated cystic fluid. A 62-year-old woman was admitted with a 10 x 10 cm painful mass occupying the right breast. Ultrasonography revealed a cystic lesion with papillary projections arising from the cyst wall. Cytological examinations showed no malignant cells in the hemorrhagic aspirated fluid. However, the CEA level in the fluid was 5.5 times higher than the serum CEA level using a murine anti-CEA monoclonal antibody. The high level of CEA led to the preoperative diagnosis of intracystic carcinoma. Histological examinations confirmed the diagnosis of intracystic carcinoma after a modified radical mastectomy. Immunohistochemical staining by an anti-CEA monoclonal antibody elicited a strong positivity with diffuse intracytoplasmic distribution in the carcinoma cells, although heterogeneity of staining was observed. It is suggested that the measurement of the CEA value by anti-CEA monoclonal antibody in the aspirated fluid is easy, safe, and helpful for the definitive diagnosis of intracystic carcinoma of the breast.

Breast Neoplasms↗