Biomedical subjects

T Tobe

Publications and source records attributed to T Tobe.

At least 19 recordsLinked to original sources

PubMed1992

Expression of epidermal growth factor receptor after partial pancreatectomy in adult rats: an immunohistochemical study.

The expression and localization of epidermal growth factor (EGF) were investigated immunohistochemically using an anti-EGF receptor antibody in the pancreas of partial pancreatectomized and sham-operated adult rats. In the sham-operated pancreas, immunoreactive products against EGF receptor were only slightly positive in the pancreatic acinar cells. In the partial pancreatectomized pancreas on the fifth day after operation, EGF receptor immunoreactivity was intensely positive in the acinar cells, in some cells lining the intercalated ducts and some basal cells of the acinus, but it was not detected in the pancreas when exogenous EGF was given to the rat after partial pancreatectomy for three days. The present results suggest that EGF receptor is expressed in the regenerating pancreatic tissue, and EGF could be involved in the mechanism of pancreatic regeneration in rats.

Animals↗

PubMed1992

Extensive en bloc resection of regionally recurrent carcinoma of the rectum.

To remove regionally recurrent cancer of the rectum completely, more radical extensive resections were attempted than the conventional ones in 35 patients. Twenty-two patients underwent total pelvic exenteration. In 23, sacral resection was done, combined with other procedures including excision of the entire circumference of the lower pelvic ring. There were two hospital deaths. Delayed wound healing was seen in ten. Preoperative severe pain was alleviated in 18. Also, perineal ulcer, vaginal bleeding, bloody stools, and tenesmus disappeared. Of the four 5-year survivors (estimated rate, 23%), only one was disease-free. A second recurrence was seen in 27 patients, of whom 23 had regional failure. It was concluded that so-called local recurrence is a lesion more widespread than indicated by imaging and biopsy. Therefore, even the most radical resection rarely can cure this disease. However, such a surgical procedure can afford more effective palliation than other treatments and may prolong life in selected patients significantly.

Adenocarcinoma↗

PubMed1992

Complete determination of disulfide bonds localized within the short consensus repeat units of decay accelerating factor (CD55 antigen).

Decay accelerating factor (DAF) has 4 SCR (short consensus repeat) units. Each SCR unit consists of approx. 60 amino acids characterized by having four conserved cysteine residues and several other highly conserved residues which include proline, tryptophan, tyrosine/phenylalanine and glycine. To determine the disulfide-bonding pattern, we used the urine form of DAF. After thermolysin and trypsin digestion, we isolated seven disulfide-linked peptides by HPLC purification. Because all of the cysteine residues are disulfide-bonded, DAF should contain eight disulfide bonds. After subtilisin and trypsin digestion, we isolated the eighth disulfide-bonded peptides by HPLC purification. From sequence analyses of these peptides, we could identify all disulfide bonds in the 4 SCR units of DAF as being between the first and the third and between the second and the fourth half-cystines within each SCR unit.

Amino Acid Sequence↗

PubMed1992

Immunohistochemical study on epidermal growth factor (EGF) receptor during carcinogenesis in the rat liver.

The expression and localization of epidermal growth factor (EGF) receptor were investigated immunohistochemically using anti-EGF receptor antibody in the normal rat liver and 3'-methyl-4-dimethylaminoazobenzen (3'-Me-DAB) induced tumors in rats. In 8 weeks after 3'-Me-DAB treatment, multiple nodules of cholangiocarcinoma were found in the rat liver, and atypical nodules of hepatocytes were also found 14 weeks later. Immunoreactive products against EGF receptor were only slightly positive in the normal liver, the nodule of cholangiocarcinoma, and atypical nodule of hepatocytes. It was noted that EGF receptor immunoreactivity was more intense in non-cancerous tissue adjacent to tumorous nodules than in the cancerous tissue. The present finding suggests that the expression of EGF receptor may be associated with regenerating as well as carcinogenetic processes in the rat liver.

Adenoma, Bile Duct↗

PubMed1992

[Protective effect of prostaglandin E2 on cerulein-induced rat pancreatitis].

In order to clarify the effect of prostaglandin E2 (PGE2) on cerulein-induced rat pancreatitis, we investigated the interaction of PGE2 with cerulein or secretin. Intravenous infusion of 10 micrograms/kg.h cerulein inhibited external secretion of the pancreas from one hour and caused macroscopic edema at 3 hours. Administration of PGE2 relieved the inhibitory effect of supramaximal dose of cerulein and decreased the pancreatic edema. The 100 micrograms/kg.hr PGE2 had no significant effect on the pancreatic juice volume and amylase secretion stimulated with 0.2 micrograms/kg.hr of cerulein. Intravenous injection of 100 micrograms/kg PGE2 inhibited both the volume and amylase secretion of pancreatic juice stimulated with 1 U/kg.h of secretin. The protective effect of PGE2 on cerulein-induced pancreatitis was not the stimulation on secretion but caused the cytoprotective effect of PG such as stabilization of cytoplasmic and lysosomal membrane.

Acute Disease↗

PubMed1992

Predictive factors for intrahepatic recurrence of hepatocellular carcinoma after partial hepatectomy.

To establish useful predictors of the intrahepatic recurrence of hepatocellular carcinoma (HCC) after partial hepatectomy, retrospective analyses of clinical and pathologic factors were done in 112 of 206 patients treated by partial hepatectomy. The absence or presence of intrahepatic recurrence was confirmed by a follow-up study. Cancer-free survival rates after 1, 2, 3, and 5 years were 54.8%, 36.7%, 32.5%, and 25.6%, respectively. The significant factors affecting recurrence were tumor size, number of tumors, cancer cell infiltration of the fibrous capsule of the tumor, portal involvement, and stage of the tumor, but the grade of anaplasia according to Edmondson-Steiner's classification and the severity of associated liver cirrhosis did not show a correlation with the incidence of recurrence. According to Akaike's Information Criteria (AIC), tumor number is useful for predicting early prognosis, and capsular infiltration is a good indicator of long-term survival. However, portal involvement gives much prognostic information throughout the entire postoperative period.

Adult↗

PubMed1992

Characterization of 21 newly established esophageal cancer cell lines.

Twenty-one esophageal cancer cell lines (KYSE series) have been established from the resected specimens of patients with esophageal cancer. Three lines, KYSE-30, KYSE-50, and KYSE-70, were derived from the implanted tumor of nude mice (initial passage); others were derived from resected specimens. Each cell line was morphologically distinct. Detailed cytogenetic analysis indicated that each cell line was karyotypically unique, and DNA fingerprint analysis showed no cross-contamination among cells. Doubling time ranged from 13.7 to 75.5 hours, and modal chromosome numbers ranged from 46 to 120. Most cell lines grew in monolayer, but two cell lines (KYSE-50 and KYSE-360) grew as floating cell aggregates. No correlation was demonstrated between the establishment of cell lines and cell differentiation. These cell lines are the first reported to be homogeneous and individually unique and may provide a useful model for the study of human esophageal cancer.

Animals↗

PubMed1992

Evaluation of microcirculation in the tumor-bearing liver of rabbits by laser-Doppler flowmetry.

Hemodynamic changes in normal liver tissue and in intrahepatic tumors (Vx2 carcinoma) after occlusion of the hepatic arterial branch or the portal branch (ex. 1), and with intrahepatic arterial infusion of vasoactive agents (ex. 2) were studied in rabbits by a laser-Doppler flowmeter. Ex. 1: After occlusion of the hepatic arterial branch to the main lobe, laser-Doppler flow (LDF) in main lobe normal tissue decreased by 11 +/- 11% in the control group, 37 +/- 37% in group Ia (tumors were 10-20 mm in diameter) and 49 +/- 37% in group Ib (tumors were 25-50 mm), so it seemed that the proportion of portal blood flow in the normal tissue microcirculation decreased with tumor growth. The tumor LDF decreased by 88 +/- 13%. After occlusion of the portal branch, the normal tissue LDF in the main lobe decreased and then recovered slightly (most evident in the control group and least in group Ib). This recovery was probably due to the hepatic arterial buffer response. The tumor LDF decreased by 36 +/- 10% in group Ia and 11 +/- 17% in group Ib. There was no difference between group I (tumors were implanted directly) and group II (tumors were implanted via portal vein). Ex. 2: Adenosine and prostaglandin E1 increased blood flow in the normal tissue and decreased the tumor blood flow, while angiotensin II had the opposite effect. Vasoactive agents can be used to selectively increase or decrease tumor blood flow and are available as adjuvants for the treatment of liver tumors. Adenosine may enhance the selective tumor heating in local hyperthermia.

Animals↗

PubMed1992

Metabolic bone disease following gastrectomy: assessment by dual energy X-ray absorptiometry.

Although disorders in bone metabolism have long been recognized as typical sequelae of gastrectomy, there has until now been no reliable method of providing precise assessment of bone mass, resulting in a variation of reported incidence. In this study, metabolic bone disease was evaluated in a well characterized population: 34 men 2-5 years after gastrectomy; 11 men 6-10 years after gastrectomy; eight men 2-5 years after colonic resection; and 115 healthy men. The age range was 50-69 years. An innovative reliable method of dual energy X-ray absorptiometry was used which allows quantitative assessment of bone mineral content. Measurement of lumbar spine bone mineral density revealed that the mean(s.e.m.) bone mineral density in patients who had had a gastrectomy (2-5 years 0.84(0.03) g/cm2, 6-10 years 0.85(0.05) g/cm2) was significantly lower than that of patients who had undergone colonic resection (0.96(0.04) g/cm2) or healthy men (0.96(0.03) g/cm2). This study demonstrates that a high incidence of bone atrophy is induced at the relatively early period of 2-5 years after gastrectomy.

Absorptiometry, Photon↗

PubMed1992

Experimental chemotherapy for xenograft cell lines of human bile duct and gall bladder cancers in nude mice.

Most biliary tract cancers are advanced and inoperable when first diagnosed. Even if surgery can be performed, the postsurgical prognosis of these diseases is poor. In the present study, we investigated effective chemotherapies for a human bile duct cancer xenograft cell line (undifferentiated carcinoma, BDC-SN) and a gall bladder cancer xenograft cell line (well-differentiated adenocarcinoma, GBC-GN), which were transplanted into nude mice. Eight anticancer agents (CDDP, 5-FU, VDS, MMC, ADR, EPIR, CQ, and VP-16) and their various combinations were evaluated at 2-4 times the clinical dose. When used singly, CDDP, 5-FU, and VDS were effective against BDC-SN, and only CDDP was effective against GBC-GN. Among the various 2-agent combinations, CDDP + 5-FU was the most effective against both BDC-SN and GBC-GN. However, 3-agent combinations consisting of CDDP + 5-FU + another agent were less effective than the CDDP + 5-FU double regimen and caused significant loss of weight as well as high mortality. These results suggest that CDDP + 5-FU may be the most useful regimen against biliary tract cancers in clinical application.

Adenocarcinoma↗

PubMed1992

SP-40,40 is a constituent of Alzheimer's amyloid.

Cerebrospinal fluid (CSF), serum and seminal plasma contain a small amount of SP-40,40, a modulatory protein of the human complement system. The SP-40,40 in each body fluid was different in molecular size on SDS-PAGE, and glioblastoma cells, hepatoma cells and testicular tumor cells produced SP-40,40, while neuroblastoma cells did not. Therefore, it was estimated that CSF SP-40,40 originated in glia cells, serum SP-40,40 in liver cells and seminal plasma SP-40,40 in testicular cells. SP-40,40 concentrations in CSF of the patients with Alzheimer's disease and the patients with cerebral tumor were higher than those of normal donors. beta-Amyloid deposits in the brains of the patients with Alzheimer's disease were stained with an anti-SP-40,40 monoclonal antibody (mAb) but not with an anti-S-protein mAb, while cellular processes around beta-amyloid were stained with an anti-S-protein mAb but not with an anti-SP-40,40 mAb. Therefore, beta-amyloid contained SP-40,40 in a form different from that in the soluble membrane attack complex (SMAC, SC5b-9) of the complement, which contains S-protein as well as SP-40,40.

Alzheimer Disease↗

PubMed1992

Usefulness of preoperative low dose cisplatin treatment for advanced esophageal cancer.

In order to decrease the perioperative complications by preoperative cisplatin chemotherapy, the preoperative single administration of cisplatin (30 mg/m2) was performed weekly from one to six times in 36 consecutive patients with esophageal cancer classified as higher than Stage II. The survival curve of 17 patients in Stage III was significantly better (P < 0.05) than that of patients who had been treated without preoperative cisplatin treatment. In 3 of the 12 patients who had locally invasive cancer, either the main tumors or the metastatic lymph nodes, which had invaded the trachea or the left main bronchus, sufficiently receded, so that a curative esophagectomy became possible; 2 of them have survived over 33 months while 1 died of pneumonia 33 months after surgery. The number of perioperative complications was minimal, and thus, we consider that the postoperative use of cisplatin and fluorouracil is indicated in patients in whom a histological response is noted in the resected specimens.

Aged↗

PubMed1992

Hemodynamic changes after resection of thoracic duct for en bloc resection of esophageal cancer.

An en bloc resection of esophageal cancer is one of the most radical forms of esophagectomy, and includes the resection of the thoracic duct, but a relatively high hospital mortality rate has been reported. There is very little knowledge on the pathophysiological changes after resection of the thoracic duct. We examined 24 patients who underwent en bloc resection. Some patients developed severe tachycardia or shock postoperatively which subsided after a massive infusion of plasma. Analysis of the fluid balance revealed that much more fluid was necessary during surgery and the postoperative 24 h than in patients treated by a standard esophagectomy. Postoperative lymphangiography or CT revealed abnormal collateral lymphatics around the kidneys or in the pelvic cavity. This suggests the development of the lymphaticovenous shunts, which differed depending on the anatomy of each patient. One patient with chronic hepatitis developed uncontrollable ascites. These are important findings which can hopefully reduce the high rate of hospital death after this operation.

Aged↗

PubMed1992

Role of ischemia in acute pancreatitis. Hemorrhagic shock converts edematous pancreatitis to hemorrhagic pancreatitis in rats.

Ischemia has been considered to play a role in the development of acute pancreatitis. The aim of this study was to investigate the effect of ischemia, caused by hemorrhagic shock, on cerulein-induced acute pancreatitis in rats. Acute pancreatitis was induced by the intravenous infusion of a supramaximally stimulating dose of cerulein (10 micrograms/kg/hr) for 6 hr. Hemorrhagic shock was induced by the removal of blood until the mean arterial blood pressure reached 35 mm Hg. This level was maintained for 30 min, after which time all the blood was reinfused. Hemorrhagic shock alone induced no morphological change in the pancreas. However, after the induction of hemorrhagic shock in animals treated with cerulein, hemorrhage and parenchymal necrosis were frequently observed in the pancreas. Seven of 20 rats (35%) receiving cerulein plus hemorrhagic shock had died by 48 hr after the start of cerulein infusion, whereas none of the rats in the cerulein or shock group died during this experiment. Cathepsin B activity in the pancreas of the cerulein plus shock group was significantly higher than in the other groups at 48 hr. These results suggest that ischemia may be a contributing factor in the pathogenesis of acute pancreatitis.

Acute Disease↗

PubMed1992

Effects of gastric inhibitory polypeptide and glucagon on portal venous and hepatic arterial flow in conscious dogs.

Gastric inhibitory polypeptide (GIP) has considerable structural homology with glucagon, which is known to increase liver blood flow. We compared the effects of GIP on portal venous and hepatic arterial flow with those of glucagon in conscious dogs. Injection of GIP significantly increased portal venous flow in a dose-related manner (by 7%, 15%, and 46% at doses of 1, 100, and 500 pmol/kg, respectively). The increase in portal venous flow induced by GIP and glucagon was comparable; however, the increase in portal venous flow after GIP injection reached its peak significantly earlier than that after glucagon injection. Hepatic arterial flow decreased after GIP injection (by 17%, 21%, and 35% at doses of 1, 100, and 500 pmol/kg, respectively), whereas it was not altered by glucagon. Thus, GIP causes significant changes in both portal venous and hepatic arterial flow in conscious dogs. Although structurally related, GIP and glucagon may influence liver blood flow through different mechanisms.

Animals↗

PubMed1992

Evidence for a role of free radicals by synthesized scavenger, 2-octadecylascorbic acid, in cerulein-induced mouse acute pancreatitis.

To define the role of free radicals and of lipid peroxide involvement during the progress of cerulein-induced acute pancreatitis in mice, we evaluated the effect of a novel free radical scavenger, 2-octadecylascorbic acid (CV-3611), on pancreatic edema formation, and the levels of serum enzymes (amylase, lipase) and of lipid peroxide in pancreatic tissue. Mice were divided into three groups: control group, intraperitoneal injection of saline only; pancreatitis group, cerulein 50 micrograms/kg injected intraperitoneally six times at 1-hr intervals; treatment groups, CV-3611 10 mg/kg subcutaneously just after intraperitoneal cerulein injection. After the cerulein injection, the degree of pancreatic edema formation, serum amylase and lipase levels, and the amount of lipid peroxide in pancreatic tissue increased significantly during the observation period of 12 hr. Treatment with CV-3611 resulted in significant reduction in pancreatic edema formation at 3.5 hr (P less than 0.05) and 9 hr (P less than 0.05), serum amylase and lipase levels at 3.5 hr (P less than 0.05) and 12 hr (P less than 0.05), and lipid peroxide levels at 3.5 hr (P less than 0.05), 6 hr (P less than 0.05) and 12 hr (P less than 0.05). These results indicate that a novel free radical scavenger, CV-3611, has a strong therapeutic effect during the development of acute pancreatitis and suggest that oxygen-derived free radicals play an important role in the pathogenesis of acute pancreatitis.

Acute Disease↗

PubMed1992

Enhancement of rat hepatic macrophages by treatment with interleukin-2 and streptococcal preparation OK432, with reference to antitumor activity, soluble factor production and Ia expression.

The effect of biological response modifiers, such as interleukin-2 (IL-2) and streptococcal preparation OK432, on the functions of hepatic macrophages was investigated. The macrophages, even with no exogenous stimulation, produced superoxide anion (O2-) and tumor necrosis factor (TNF), displayed cytotoxicity against K562 cells and cytostasis against P815 cells and expressed immune-region-associated antigen (Ia). IL-2 administered in vitro or in vivo enhanced O2- production by hepatic macrophages and the intravenous injection of OK432 also enhanced O2 production. Furthermore, IL-2 added to the culture medium of hepatic macrophages isolated from OK432-injected rats augmented O2- production even more. The TNF production and Ia expression of the macrophages were also increased by the intravenous injection of OK432. As with O2- production, the cytotoxicity of the cells was enhanced by OK432 injection or by IL-2 added to the culture medium and the combination of OK432 and IL-2 augmented their cytotoxicity even more. Thus, the present study suggested that IL-2 and OK432 induce the augmentation of the antitumor activity of hepatic macrophages, partly as a result of the increase in production of O2- and TNF and Ia expression.

Animals↗

PubMed1992

Comparative effects of a recombinant and a mutein type of granulocyte colony stimulating factor on the growth of Meth-A fibrosarcoma with 5-fluorouracil chemotherapy.

The present study was designed to evaluate the effects of a recombinant human G-CSF (rhG-CSF) and a mutein G-CSF (KW-2228) on leucopenia and tumor growth in mice treated with 5-fluorouracil (5-FU). In normal mice, the number of leucocytes (white blood cell, WBC) reached the peak 12 hours after a single injection of either type of G-CSF and decreased to the normal level after 24 hours. Daily administration induced a continuous increase in the WBC count, however, administrations at intervals did not. Meth-A fibrosarcoma was subcutaneously inoculated into the backs of syngeneic BALB/c mice. The mice were treated with 5-FU alone or with G-CSFs. Chemotherapy with 5-FU alone resulted in leucopenia and an insignificant inhibition of tumor growth. The conjunctive administration of G-CSFs with 5-FU resulted in a significantly augmented inhibition of tumour growth, and leukopenia was not seen. This augmenting effect was more prominent with KW-2228. These results suggest that in 5-FU chemotherapy G-CSFs may be beneficial in restoring the number of leucocytes from leucopenic state and in augmenting the tumor inhibitory effect. Furthermore, KW-2228 may be more beneficial than the natural type rhG-CSF.

Amino Acid Sequence↗