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T Homma

Publications and source records attributed to T Homma.

At least 181 records · Page 10Linked to original sources
PubMed1985

Contribution of prostaglandins to dopamine actions in the pancreas of anesthetized dogs.

We investigated the effect of dopamine and arachidonic acid on pancreatic blood flow and exocrine secretion in the isolated blood-perfused pancreas of pentobarbital sodium-anesthetized dogs without or with pretreatment with indomethacin or sodium meclofenamate in the absence and during infusion of prostaglandins I2 or E2 (PGI2 or PGE2). Intra-arterial administration of dopamine (50-500 ng/kg) produced an initial vasoconstriction followed by vasodilation and enhanced flow rate of pancreatic exocrine secretion. Arachidonic acid (0.5-5 micrograms/kg) produced vasodilation without altering the flow rate of pancreatic exocrine secretion. In animals pretreated with indomethacin or sodium meclofenamate (10 mg/kg iv), the magnitude and the duration of the biphasic vascular response but not the increase in flow rate of pancreatic exocrine secretion elicited by dopamine were reduced. Arachidonic acid-induced vasodilation was abolished by the cyclooxygenase inhibitors. During infusion of PGI2 or PGE2 (10 ng X kg-1 X min-1 ia), the inhibitory effect of indomethacin or sodium meclofenamate on the vasodilator phase of the response to dopamine was diminished. These data suggest that prostaglandins, presumably PGI2 and PGE2, contribute to the effect of dopamine to increase pancreatic blood flow but not to increase pancreatic exocrine secretion in anesthetized dogs.

Animals↗
PubMed1985

[Noninvasive estimates of pulmonary hypertension and study of the etiology of ejection flow velocity profiles].

Flow velocities at the right ventricular outflow tract were recorded for 36 patients including 12 with pulmonary hypertension. Doppler indexes [right ventricular preejection period (RPEP), right ventricular ejection time (RET), right ventricular acceleration time (RAT), RPEP/RET, RET/RAT] were calculated from flow velocity profiles, and noninvasive estimation of pulmonary hypertension was attempted using these indexes. The etiology of ejection flow velocity in pulmonary hypertension was studied using a simulation model. The following results were obtained. RAT shortened proportionately with an increase of pulmonary arterial pressure. RET/RAT correlated most significantly with pulmonary arterial pressure (r = 0.83, p less than 0.001). RET/RAT correlated inversely with stroke volume (SV) (r = -0.48, p less than 0.01); therefore, attention should be paid to SV, when estimating pulmonary arterial pressure, using the value of RET/RAT. The diagnostic value for pulmonary hypertension using RET/RAT was excellent; the predictive accuracy was 100%, sensitivity 75%, and specificity 100%, and it was possible to evaluate pulmonary hypertension using this method. According to the simulation model, an increase of both the pulmonary pulse wave velocity and the reflection of the pulse wave made the interval between the onset and the time of the peak flow velocity shorter. A flow velocity pattern similar to that of pulmonary hypertension was obtained.

Adolescent↗
PubMed1985

Permissive role of prostaglandins in the action of bradykinin on the pancreas of anesthetized dogs.

We have investigated the contribution of prostaglandins (PGs) to the effect of bradykinin on pancreatic blood flow and pancreatic exocrine secretion by examining its actions in the isolated blood-perfused pancreas of pentobarbital-anesthetized dogs. Intra-arterial injections of bradykinin (0.05-5 ng/kg) into the pancreas produced a dose-dependent vasodilation and increased pancreatic blood flow; the rate of flow, bicarbonate concentration, protein content or pH of the pancreatic juice was not altered. Administration of arachidonic acid (0.5-5 micrograms/kg) into the pancreas also produced vasodilation without altering pancreatic exocrine secretion. In animals pretreated with indomethacin or sodium meclofenamate (10 mg/kg i.v.), the vasodilator effect of bradykinin was attenuated, whereas that of arachidonic acid was abolished; the pancreatic exocrine secretion was not altered. The vasodilation produced by sodium nitroprusside (0.3 micrograms/kg i.a.) in the pancreas was not altered by indomethacin. During infusion of PGI2 or PGE2 (10 ng/kg/min i.a.), the effect of indomethacin or sodium meclofenamate to attentuate bradykinin-induced vasodilation was reduced. However, the sodium nitroprusside-induced vasodilation in animals treated with indomethacin was not altered during infusion of PGI2 or PGE2. These data indicate that PGs, presumably PGI2 and PGE2, play a permissive role in the vasodilator effect of bradykinin in the pancreas of anesthetized dogs. Moreover, these studies suggest that neither bradykinin nor PGs contribute to the regulation of pancreatic exocrine secretion.

Animals↗
PubMed1984

Lymphoma in macaques: association with virus of human T lymphotrophic family.

Human T-cell leukemia virus has been linked with adult T-cell leukemia-lymphoma (ATLL), a tumor of mature T cells that occurs at elevated rates in southwestern Japan and in the Caribbean Basin. Human T-cell leukemia virus (HTLV) or a closely related virus, has also been found in varying proportions of healthy individuals of several species of Old World monkeys. In the present study, conducted with macaques from Taiwan and the New England Regional Primate Research Center, antibodies to membrane antigens of HTLV-infected cells (HTLV-MA) were found in 11 of 13 macaques with malignant lymphoma or lymphoproliferative disease but in only 7 of 95 of healthy macaques. This indicates that antibodies to HTLV are significantly associated with the development of naturally occurring lymphoid neoplasms in at least some species of nonhuman primates.

Animals↗
PubMed1984

Human T-cell leukemia virus-associated membrane antigens: identity of the major antigens recognized after virus infection.

Specific antibodies to cell membrane antigens found on human T-cell leukemia virus (HTLV)-infected cells have been detected in Japanese patients with adult T-cell leukemia/lymphoma and in asymptomatic carriers, using a live cell-membrane immunofluorescence assay. Reactivity of the positive antisera was analyzed using radioimmunoprecipitation and NaDodSO4/PAGE with the HTLV-infected tumor cell line Hut 102 (clone B2). The major cell-associated antigens identified include two glycoproteins of approximately equal to 61 and 45 kDa, which appear to be the most immunogenic species in exposed people, a nonglycosylated species of 42 kDa, and four additional species that contain gag gene-encoded antigens with sizes ranging from 19 to 55 kDa. The two glycoproteins ( gp61 and gp45 ) are encoded, at least in part, by the env gene of HTLV as evidenced by amino acid sequence analysis.

Amino Acid Sequence↗
PubMed1984

Clinical use of the measurement of airway resistance during spontaneous respiration.

Airway resistance was measured during spontaneous respiration in healthy smokers and patients with chronic obstructive pulmonary disease, and the relationship between the airway resistance and respiratory frequency was examined. No significant difference was observed between the airway resistance in smokers and nonsmokers. In the chronic obstructive pulmonary disease group, patients with pulmonary emphysema had highest airway resistance. The determination of airway resistance during spontaneous respiration appears to be a very useful, noninvasive method of pulmonary function testing.

Adult↗
PubMed1984

HTLV and immunosuppression.

There is increasing evidence for the link between members of the human T-lymphotropic virus family and clinically important disease. We used indirect membrane immunofluorescence (IMI) to screen patient and control sera for antibodies to human T-cell leukemia virus (HTLV) specific cell membrane antigens (HTLV-MA) of HTLV-I and HTLV-III. Representative sera were screened for antibodies to specific HTLV-encoded proteins using radioimmunoprecipitation (RIP) with SDS-polyacrylamide gel electrophoresis (SDS-PAGE). Essentially all Japanese patients with adult T-cell leukemia/lymphoma (ATLL) from Miyazaki, Japan had detectable antibodies to HTLV-I-MA, further supporting the evidence for the probable etiologic relationship of HTLV-I and ATLL. While 16% of the healthy adults from this endemic region had antibodies to HTLV-I-MA, such antibodies were also found in 42% of the adults hospitalized in Miyazaki with severe infections diseases. Other studies have demonstrated HTLV-I antibodies in 12% of asymptomatic hemophiliacs examined from various U.S. cities. We have previously shown that HTLV-I status positive antibody in hemophiliacs is accompanied by a decrease in the number of T helper cells. Patients seropositive for antibodies to HTLV-I-MA regularly demonstrated antibodies to the env gene encoded gp61 proteins, while lower but significant proportions had antibodies to the gag and lor gene proteins. These and other observations suggest that infection with at least some strains of HTLV-I may be associated with mild or transient immunosuppression, in the absence of leukemia. Analysis by RIP indicated that gp61 and gp45, both encoded by the env gene of HTLV-I, are the most immunogenic proteins of the virus. The gp61 HTLV-I is highly crossreactive with gp67, the major env protein of HTLV-II. Patients with acquired immune deficiency syndrome (AIDS) were also examined for antibodies to HTLV-I-MA and antibodies to the gag, env, and lor gene proteins by RIP. Antibodies were detected in 38-75% of the patients, the higher percentage reflecting the presence of at least one positive sample in those individuals where more than three serial serum samples were tested. Numerous control groups were essentially seronegative for antibodies to HTLV-I proteins. When AIDS patient sera were examined for antibodies to HTLV-III, 95-100% were seropositive. Such antibodies were also found in the majority of asymptomatic Boston-areas hemophiliacs.(ABSTRACT TRUNCATED AT 400 WORDS)

Acquired Immunodeficiency Syndrome↗
PubMed1984

[Pancreatic oncofetal antigen (POA) and carcinoma of the pancreas].

Pancreatic oncofetal antigen (POA) was purified from fetal pancreas and migrated in beta-region electrophoretically. Its molecular weight was 80 X 10(4) daltons. Enzyme immunoassay for serum POA revealed that elevated levels of POA were found in sera of patients with pancreatic cancer. By a serological screening of 440 out-patients with combined assay of tumor markers including POA, 4 cases of pancreatic cancer were found. POA was demonstrated in the ductal cells of fetal pancreas and cancer cells of duct cell type pancreatic adenocarcinoma immunohistochemically. Elevated levels of serum POA of patients with pancreatic cancer was probably derived from cancer tissue. These findings indicate that serum POA assay is clinically useful.

Adenocarcinoma↗
PubMed1984

A pancreatic oncofetal antigen (POA): its characterization and application for enzyme immunoassay.

We investigated the usefulness of enzyme immunoassay (EIA) for pancreatic oncofetal antigen (POA). The crude POA isolated from POA-positive ascitic fluid of patients with pancreatic cancer was injected into rabbits to raise anti-POA serum. The adsorbed antiserum was used for EIA as anti-POA serum. For the establishment of EIA system for POA, anti-POA-Fab' fragment was conjugated to beta-D-galactosidase from Escherichia Coli. Normal subjects (205 controls) and 132 patients (47 with pancreatic cancer, 22 with chronic pancreatitis, and 63 with other malignant disease) were surveyed. The standard serum from patient M with pancreatic cancer was used in quantitatively determining serum POA levels; value was expressed arbitrarily as 1000U/ml. Normal upper limit of POA was defined as less than 400U/ml (mean + 2SD of normal subjects). POA level higher than normal was observed in 72% of patients with pancreatic cancer, 23-44% of patients with other malignant diseases, and 18% of patients with chronic pancreatitis. The susceptibility of the isolated POA to several enzymes and chemical reagents was also studied. These results suggest the usefulness of EIA for POA in diagnosis of pancreatic cancer.

Antigens, Neoplasm↗
PubMed1984

Exocrine pancreatic cancer with humoral hypercalcemia.

Humoral hypercalcemia associated with malignancy has rarely been reported in exocrine pancreatic cancer. We report a patient with cancer of the exocrine pancreas who presented with hypercalcemia which did not respond to indomethacin. Her serum levels of parathyroid hormone and vitamin D derivatives were low. Technetium diphosphonate bone scan revealed no evidence of bone metastasis, a finding which was confirmed at autopsy. On light microscopy, histological classification of the tumor was moderately differentiated tubular adenocarcinoma. The electron microscopic study, however, revealed a few zymogen-like granules containing cancer cells lying between ductal-type cancer cells. A review of humoral hypercalcemia in cancer of the exocrine pancreas is presented. A humoral factor(s) other than parathyroid hormone, prostaglandin E, and vitamin D derivatives is considered responsible for hypercalcemia in this patient.

Adenocarcinoma↗
PubMed1983

Serum pancreatic oncofetal antigen: its clinical usefulness for screening pancreatic cancer in combination with tests for other tumor markers.

Screening for pancreatic cancer was carried out by serum pancreatic oncofetal antigen (POA) tests in 440 out-patients with abdominal complaints, with concomitant assay of carcinoembryonic antigen, alpha-fetoprotein and ferritin. POA was positive in 13 patients, of whom 3 cases of pancreatic cancer, and 4 of other malignant diseases were diagnosed while the remaining 6 were non-malignant. Of these out-patients, 5 cases were finally diagnosed as having pancreatic cancer by further examinations. Of these 5 patients, POA was negative in 2, of whom one was positive for CEA and AFP. Accordingly, when POA test was applied concomitantly with the other 3 marker tests, the detection rate of pancreatic cancer was elevated to 4/5. Twenty-three patients were found to have malignant diseases and 20 of them were positive for at least one of the 4 markers tested. These results suggest that serum POA assay is useful for screening the pancreatic cancer, especially when the other tumor markers are assayed concomitantly.

Adult↗
PubMed1983

Clinical application of the enzyme immunoassay for pancreatic oncofetal antigen.

Pancreatic oncofetal antigen (POA) purified by us has been detected in sera of patients with carcinoma of the pancreas by the micro-Ouchterlony method. In an attempt to improve the sensitivity and clinical usefulness of the serum POA assay, we established an enzyme immunoassay for POA and reported the results with this method. In this study, we investigated serum POA levels in pancreatic cancer and other diseases. The tissue localization of this POA in the pancreas was also studied. For the establishment of the enzyme immunoassay, an anti-POA-F(ab')2 fragment prepared from absorbed antiserum was conjugated with beta-D-galactosidase. The solid-phase "sandwich" principle was used. The normal upper limit of the serum POA level was defined as 400 units/ml. Among 60 patients with pancreatic cancer, 44 had elevated levels (73.3%). Of 22 cases with chronic pancreatitis, 4 had elevated levels (18.2%). In malignant diseases other than pancreatic cancer, elevated levels of serum POA were seen in 17.6% to 48.5% of the patients, most of whom had only slightly elevated levels. These results indicate that enzyme immunoassay for POA is clinically useful for making a diagnosis of pancreatic cancer. Immunoperoxidase staining showed POA to be found at the apical surface of ductular cells in fetal pancreas, at the luminal surface of glandular structures in pancreatic cancer tissue, and also at the luminal surface of the small duct in normal pancreas. Thus it is suggested that a high level of serum POA in patients with pancreatic cancer is derived from pancreatic cancer tissue.

Adult↗