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Biomedical subjects

T Homma

Publications and source records attributed to T Homma.

At least 199 records · Page 11Linked to original sources
PubMed1983

Effect of secretin and caerulein in canine pancreas: relation to prostaglandins.

We investigated the effect of secretin and caerulein on pancreatic circulation and exocrine secretion and its relation to prostaglandin (PG) synthesis by studying the effect of these peptides on the pancreatic blood flow and the flow rate of pancreatic exocrine secretion in the isolated blood-perfused pancreas of pentobarbital-anesthetized dogs without or with pretreatment with the cyclooxygenase inhibitors, indomethacin and meclofenamate. Intra-arterial administration of secretin (0.1-0.3 U/kg) produced an initial vasoconstriction followed by vasodilation. On the other hand, caerulein (50-200 ng/kg) produced vasodilation and increased pancreatic blood flow in a dose-related manner. Both secretin and caerulein increased the flow rate of pancreatic exocrine secretion. In animals pretreated with either indomethacin or meclofenamate, the ability of secretin to produce an initial vasoconstriction was abolished and the subsequent vasodilator component of the response as well as caerulein-induced vasodilation were reduced in duration. The effect of caerulein but not of secretin to stimulate the flow rate of pancreatic exocrine secretion was reduced by indomethacin and meclofenamate. Administration of PGI2 and PGE2 into the pancreas caused vasodilation, whereas PGF2 alpha and PGD2 produced a biphasic effect, i.e., an initial vasoconstriction followed by vasodilation. Infusion of either PGI2 or PGE2 but not that of PGF2 alpha or PGD2 minimized the effect of cyclooxygenase inhibitors to reduce the duration of vasodilator response elicited by secretin and caerulein. Prostaglandins neither altered the basal nor the rise in flow rate of pancreatic exocrine secretion produced by secretin and caerulein. These data indicate that in the canine pancreas prostaglandins contribute to the effects of secretin and caerulein to increase pancreatic blood flow but not to their effect on pancreatic exocrine secretion.

Animals↗
PubMed1983

[Aclacinomycin; benefits for the treatment of malignant pleural effusion].

A series of experiments with ACM was performed to evaluate the effect for local treatment of malignant pleurisy from the view points of (1) clinical response, (2) pharmacokinetics following intrapleural administration, and (3) pleural reaction. The results were as follows: (1) In 6 patients with malignant pleural effusion, ACM was intrapleurally administered at a dose of 40 mg. In 4 out of the 5 evaluable cases, an extreme decrease in the pleural fluid volume and suppression of reswelling were observed, including 2 cases found to be negative for tumor cells upon cytodiagnosis. (2) In 5 patients, the pharmacokinetics was studied by using compartment model. The clearance curves of ACM in pleural fluid were described by a two-compartment model. The mean half lives of initial phase and terminal phase were 0.78 hr, and 15.28 hr, respectively. The time to reach the maximal whole blood level was 1 to 2 hrs after pleural administration, followed by a slow decline. (3) The pleural reaction to ACM was studied in rabbits by scanning and transmission electron microscope. At a dose of 4 mg per kg of body weight, the shortened microvilli, the degenerated mesothelial cells and the disappearance of basement membrane were observed. On the basis of these findings, we suggest that ACM might be an agent of choice in the treatment of malignant pleurisy.

Aclarubicin↗
PubMed1983

[Pancreatic oncofetal antigen (POA)--its characterization and the result of enzyme immunoassay].

Our studies on the partial purification, characterization and clinical application of pancreatic oncofetal antigen (POA) are presented. This antigen was purified from fetal pancreas and migrated in beta-region electrophoretically. Its molecular weight was estimated approximately 80 X 10(4) daltons on gel filtration. POA prepared by us was different from either Nishida's POA biochemically or Shimano's PCAA immunologically. Enzyme immunoassay of POA was established by conjugating with anti-POA with-D-galactosidase. Among 60 patients with carcinoma of the pancreas, 44 (73.3%) had a elevated serum POA level. A serological screening of pancreatic cancer was performed among 440 out-patients with combined assay of tumor markers including POA. Five cases with carcinoma of the pancreas were found out by this screening test. These findings indicate that serum POA assay is clinically useful.

Adult↗
PubMed1983

[Pharmacokinetics and pleural reaction of doxycycline after intrapleural administration].

Tetracycline has been used for the local treatment of malignant pleurisy ever since of Robinson (1972) reported its effectiveness. In this report, we try to elucidate possible mechanisms of action of this drug from the viewpoints of (1) pharmacokinetic analysis following intrapleural administration, and (2) pleural reaction. The results were as follows: (1) In 5 patients with malignant pleural effusion, 500 mg of doxycycline was injected into the pleural cavity and pharmacokinetic analysis was performed. The clearance curve of doxycycline in pleural fluid was described by either a one-compartment model or a two-compartment model. The mean half life of slow space was 33.3 hr, which suggested delayed excretion of this drug from pleural space. (2) The direct effect of doxycycline on pleura was studied in rabbits. At a dose of 10 mg per kg of body weight, the mesothelial cells became cuboid and contained vacuoles in their cytoplasma. With increasing dose up to 40 mg per kg, the changes in mesothelial cells were enhanced. In submesothelial tissue, edema and cellular infiltration were noticed. Three weeks later, normalization of mesothelium was observed, being followed by connective tissue proliferation. These findings may support the efficacy of tetracycline for local treatment of malignant pleurisy.

Adenocarcinoma↗
PubMed1982

Sixteen years follow-up of a patient with alcoholic pancreatitis: serial findings of morphology and function on the pancreas and the liver.

Sixteen years follow-up was performed in a male of long-standing alcohol indulgence who had an alcoholic liver disease at the outset, followed by alcoholic pancreatitis which progressed finally to pancreatic calcification. During this course, the abnormalities of endoscopic pancreatogram were unremittingly progressive, whereas exocrine and endocrine pancreatic dysfunction remained fluctuating, but ultimately deteriorated. In contrast functional and histological abnormalities of the liver were not progressive but returned toward normal. The follow-up observations in this case suggest that some cases of typical alcoholic pancreatitis may have unremittingly progressive morphologic changes with fairly well reserved capacity of exocrine and endocrine pancreatic functions and their hepatic lesions may not be in parallel with pancreatic lesions.

Adult↗
PubMed1982

Effects of cations on the outer membrane permeability of Escherichia coli.

The outer membrane permeability to beta-lactam antibiotics was determined with intact Escherichia coli cells treated with various concentrations of NaCl. It was found that the treatment of cells with moderate concentrations of NaCl caused dramatic increase in the diffusion rate of beta-lactam across the outer membrane. This increased rate of beta-lactam diffusion was not due to the high osmolarity exerted by NaCl, since the elevated osmolarity of the assay medium by sucrose had no significant effect. This increased rate of beta-lactam diffusion was restored by addition of a low concentration of MgSO4 or CaCl2 into the assay medium. These results were interpreted as that the treatment of intact E. coli cells with moderate concentration of monovalent cations squeezed out divalent cations, which presumably destabilized the outer membranes, causing electrostatic repulsion of negatively charged lipopolysaccharide molecules in site.

Ampicillin↗
PubMed1982

Effect of prostaglandins on pancreatic circulation in anesthetized dogs.

To assess the contribution of prostaglandins (PGs) to the maintenance of vascular tone and exocrine secretion in the pancreas, the effects of several products of arachidonic acid metabolism on the blood flow and flow rate of exocrine secretion were examined in the isolated blood perfused pancreas of the pentobarbital-anesthetized dog with and without pretreatment with the cyclooxygenase inhibitors, indomethacin (2 mg/kg i.v.) or sodium meclofenamate (10 mg/kg i.v.). Intra-arterial administration of PGE2, PGI2 and thromboxane B2 at doses of 30 to 300 ng/kg produced vasodilation and increased flow of blood to the pancreas. Injections of either PGF2 alpha, 30 to 300 ng/kg, or PGD2, 10 to 100 ng/kg, produced a biphasic effect, viz., transient vasoconstriction followed by a prolonged vasodilation. Administration of either indomethacin or sodium meclofenamate significantly reduced pancreatic blood flow (P less than .01). In animals pretreated with either of the cyclooxygenase inhibitors, the effect of PGE2, PGI2 or PGD2 to increase blood flow to the pancreas was prolonged in duration. Administration of either PGs, thromboxane B2 or cyclooxygenase inhibitors did not markedly alter the flow rate of exocrine pancreatic secretion. These data indicate that one or more products of arachidonic acid formed through the cyclooxygenase pathway contribute to the maintenance of pancreatic vascular bed in a dilated state.

Animals↗
PubMed1981

HLA antigens in chronic idiopathic pancreatitis compared with chronic alcoholic pancreatitis.

HLA A and B antigens in 46 patients with chronic pancreatitis were studied in Japan. Patients were divided into the two groups according to the etiology of the disease: one was chronic idiopathic pancreatitis (18 cases) and the other was chronic alcoholic pancreatitis (28 cases). One hundred twenty unrelated subjects were also examined as control. HLA B5 was detected in 14 of 18 cases of chronic idiopathic pancreatitis, which was significantly higher statistically than in control (P less than 0.001, corrected P less than 0.05). In contrast, no HLA antigens of locus A and B were found which had a relationship to chronic alcoholic pancreatitis. These results suggest that some genetic factors may be implicated in the development of chronic idiopathic pancreatitis and differing from that of alcoholic pancreatitis.

Adult↗
PubMed1981

A pancreatic oncofetal antigen: its partial purification and clinical application.

Studies on the purification, characterization and clinical application of pancreatic oncofetal antigen were reported. This antigen was purified from fetal pancreas, and migrated in the beta-region on electrophoresis. Its molecular weight was about 80 x 10(4) daltons on gel filtration with a Sephacryl S-300. This antigen is clearly different from other oncofetal antigens such as alfafetoprotein, carcinoembryonic antigen or ferritin. Clinically, this pancreatic oncofetal antigen was positive in sera of 68.4% of the patients with pancreatic cancer. However, elevated level of this antigen was also observed in the sera of some patients with biliary tract cancer, colon cancer or gastric cancer. The antigen was also found in pancreatic juice obtained from patients with pancreatic cancer in almost the same incidence as in their sera. It is suggested that a pancreatic oncofetal antigen assay of sera and pancreatic juice in combination with other oncofetal antigens is valuable for the diagnosis and monitoring the clinical course of pancreatic cancer.

Antigens, Neoplasm↗
PubMed1981

HLA antigen and chronic pancreatitis in Japan.

HLA A, B and C antigens were determined in 128 patients with chronic pancreatitis in Japan. Patients were divided into two groups, chronic alcoholic and chronic idiopathic, from two parts of Japan, the eastern and the western part, with control subjects in each region. A significantly higher frequency of B5 was demonstrated among chronic idiopathic pancreatitis and of B13 among chronic alcoholic pancreatitis in the eastern part, and no definite findings were obtained in the western part of Japan. On the other hand, the frequency of BW 54 was lower among chronic alcoholic pancreatitis in both parts of Japan, but the corrected p value for this antigen was not statistically significant. These facts suggest that 'HLA antigens in chronic pancreatitis have some racial and regional differences.

Alcoholism↗
PubMed1981

A study of chronic pancreatitis by serial endoscopic pancreatography.

The pancreatic duct system was studied with repeated endoscopic retrograde pancreatography in 31 patients with chronic pancreatitis, 32 patients with suspected chronic pancreatitis, and 16 controls without pancreatic disease. In chronic alcoholic pancreatitis the pancreatograms showed marked changes during the initial examination with progression even after abstinence or reduction of drinking. In the alcoholics with suspected chronic pancreatitis, progressive lesions in branch ducts with almost intact main ducts were recognized. In contrast, no remarkable alterations on serial pancreatograms were observed in nonalcoholic cases with definite or suspected chronic pancreatitis. These results suggest that pancreatic duct lesions play an important role in the development and progression of chronic alcoholic pancreatitis in contrast to chronic nonalcoholic pancreatitis.

Adult↗
PubMed1981

[Phonocardiographic and ultrasonocardiographic findings in seven cases of coronary artery fistula (author's transl)].

The diagnosis possibility of the involved arteries as well as drained site was studied in 7 cases of coronary artery fistula by pharmacodynamic phonocardiography and echocardiography. All cases had a continuous murmur, which was decreased soon after the inhalation of amyl nitrite but increased thereafter. These characteristic changes were diagnostic for coronary artery fistula. Two-dimensional echocardiograms could easily disclose the fistulous coronary artery with proximal dilatation, but not that without dilatation. The 2.4 and 3.5 mHz transducer used in this study revealed the fistulous coronary artery of 5 mm diameter confirmed by the angiocardiogram. However, the visualization depended on the anatomical relation to the aorta. In cases with drainage into the pulmonary artery, the fistulous coronary artery passed usually upwards near the aorta, so that it could be detected with the beam direction focussing to the anterior and posterior walls of the aorta. In these cases, the passage of the fistulous artery originating from the right coronary artery was easily recognized and the involved coronary artery was inferred. But it was difficult to follow the passage when originating from the left coronary artery.

Adolescent↗
PubMed1980

Studies on thromboplastic and fibrinolytic activities of valvular tissue in rheumatic valvular disease.

While rheumatic valvular disease (RVD) is known to develop subsequent to rheumatic carditis, we examined whether in addition to the inflammatory and repair process, thromboplastic and fibrinolytic activities of the valvular tissue play a contributory role in the pathogenesis of RVD. Both activities were higher in resected valves from RVD cases than in the controls. Tissue thromboplastin was localized in the valvular endothelium and the subendothelial connective tissue. Tissue fibrinolytic activity was prevalent in the small blood vessels of RVD valves, while it was lower on the surface of RVD valves than in the controls. High thromboplastic and low fibrinolytic activity in the surface layer of RVD valves may accelerate the deposition of thrombi, thereby inducing valvular thickening.

Blood Coagulation↗