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Biomedical subjects

H Honjo

Publications and source records attributed to H Honjo.

At least 163 records · Page 9Linked to original sources
PubMed1979

Lymphocyte response to autochthonous human solid tumor cells: relationship to histological types and tumor load.

Mixed lymphocyte--tumor cell cultures were made with materials from patients with various histological types of cancer. In 25 out of 89 patients, positive lymphocyte response to tumor cells was observed. There appeared to be an inverse relationship between the frequency of positive responses and extent of the disease. Patients with neuroblastoma, however, showed more frequent positive responses in cases of widespread disease. The data obtained may have valuable clinical implications, supporting the possibility of immunotherapy of cancer patients.

Adolescent↗
PubMed1976

The metabolic fate of chlormadinone acetate in the baboon.

The metabolic fate of chlormadinone acetate (17alpha-acetoxy-6-chloro-4, 6-pregnadiene-3, 20-dione; CAP) was studied in intact and biliary fistula baboons. The steroid was labeled with 3H at position 1 and with 14C at the carboxyl moiety of the 17alpha-acetate, thus affording the opportunity to ascertain the loss of the 17alpha-acetoxy group and the fate of both labels. The averages of the radioactivity excreted, given as percentages of the amounts injected, and the standard deviations were as follows: In the urine of intact animals after 6 hours, 5.7 +/- 0.2% and 5.5 +/- 0.7% of the 3H and 14C were recovered, respectively. After 6 days, there was 17.5% of the 3H and 16.2% of the 14C in the urine plus 15.3% of the 3H and 16.4% of the 14C in the feces. In baboons with biliary fistulas, the total radioactivity excreted was 7.8 +/- 0.7% of the 3H and 11.6% of the 14C in the urine, and 30.9 +/- 4.4% of the 3H and 30.7% of the 14C in the bile after 6 hours. Glucosiduronates were the predominant conjugates in the urine and bile. The similarity in the urinary excretion of radioactivity in the first 6 hours in intact and biliary fistula animals, the relatively low excretion of radioactivity in the bile and after 6 days in the urine, and the low fecal excretion suggest that the metabolites of CAP are not involved in an extensive enterohepatic circulation in the baboon. Deacetylation of the 17alpha-acetate in CAP was detected in the early collection periods of the urine and bile and constituted a very small percentage of the injected compound. No significant oxygenation of CAP at position 1 was detected. The metabolism of CAP is discussed and compared to our previously reported data on the metabolism of progesterone, ethynodiol diacetate and medroxyprogesterone acetate and the data on other progestogens reported in the literature. It appears that the excretion of CAP is significantly slower in the baboon than that of the other progestogens. The amounts of glucosiduronates of CAP and/or its metabolites formed in vivo are less than those formed with the other progestogens. Also, the extent of deacetylation of the 17alpha-acetate of CAP is much less than that of the 3beta-acetate of ethynodiol diacetate.

Animals↗
PubMed1976

In vivo and in vitro conjugation and metabolism of estrogens by the baboon kidney.

Labeled estrogen was injected into one of the renal arteries of baboons and urine was collected separately from each ureter via ureterostomy at various time intervals over a period of 7 h; the urinary metabolites were analyzed by DEAE-Sephadex chromatography and enzyme hydrolyses. Identification of the aglycones was made by TLC and co-crystallization upon admixture with authentic compounds. When [3H]estradiol-17beta (E2) was injected into one of the renal arteries, the major metabolites were [3H]E2-3-glucosiduronate (E2-3G) and [3H]estrone-3-glucosiduronate (E1-3G); [3H]E2-3G was excreted predominantly into the urine from the injected side during the initial 30 min after injection. Formation of [3H]E1-3G was not detectable for the first 5 min in the urine from either side. However, its excretion gradually increased and the amount was almost equal from both sides in the later hours of collection. Injection of [3H]E1 revealed ready conjugation (as E1-3G) by the kidney without significant reduction at position-17. When E2-3G, labeled with 3H at positions 6,7 and with 14C in the glucuronic moiety, was injected, it was quickly excreted in the urine of the injected side. The ratio of 3H/14C of E2-3G excreted in the urine was the same as that of the injected E2-3G. In the later periods, E1-3G, which had a slightly increased 3H/14C ratio, appeared in the urine. These results indicate that E2 and E1 are conjugated directly in the kidney to form the 3G which is excreted into the urine and that effective dehydrogenation or reduction of the steroids in vivo does not take place in the kidney. The results also show that conjugated E2 (E2-3G) is quickly excreted by the kidney of the baboon without any change in its form and that the E2-3G is dehydrogenated to E1-3G during its general circulation without significant prior removal of the glucuronic moiety. When [3H]estriol (E3) was injected, facile glucuronidation to E3-16G by the kidney was shown. Injection of an equimolar mixture of [14C]E3 and [3H]E2 showed rapid excretion of [14C]E3-16G as opposed to the slower excretion of [3H]E2-3G. These results suggested that the active sites of these conjugating enzyme systems in the kidney may be different.

Animals↗
PubMed1976

Studies on phenolic studies in human subjects. XX. In vivo conjugation and metabolism of estradiol-17beta in the human kidney.

Labeled estradiol-17beta (E2) was injected into one of the renal arteries of two human subjects. At the same time, an equimolar amount of differently labeled E2 was injected into a peripheral vein. The urinary metabolites were analyzed by DEAE-Sephadex A-25 column chromatography, countercurrent distribution (CCD) and enzyme hydrolyses. Identification was made by statistical analysis of data from CCD, thin layer chromatography (TLC) and co-crystallization upon admixture with authentic compounds. The major urinary metabolites were E2-17glucosiduronate (E2-17G), E2-3G and estriol-16G (E3-16G). The E2-17G was excreted immediately following injection of 14C-E2 into the renal artery of subject no. 1, at a rate which decreased gradually with time; whereas 3H-E2-17G did not appear in the urine until 5 min after injection of 3H-E2 into a peripheral vein. The excretion of 14C-E2-17G was very prominent as opposed to that of 3H-E2-17G; however, the excretion of both 14C- and 3H-E2-17G terminated within 30 min. 14C-E2-3G was excreted immediately following injection, whereas 3H-E2-3G did not appear until 5 min after the injection. Also, the excretion of 14C-E2-3G was more prominent as opposed to that of 3H-E2-3G. The excretion of these compounds was rapid in the initial 15 min after injection and then continued slowly for 1 h. On the other hand, 14C- and 3H-E2-16G appeared at 30 min after injection and the 3H/14C ratio was almost the same as that of the injected compounds. When subject no.2 was injected with the labeles reversed, the results were very similar to those described above. The results indicate that E2 is conjugated directly in the human kidney to form the 17G and 3G and excreted into the urine, whereas the conversion of E2 to E3 occurs systematically rather than in the kidney. In contrast of E3, the kidney appears to play a minor role (no more than 10% of the total E2 is involved) in the conjugation and/or metabolism of E2 in the human.

Estradiol↗
PubMed1975

[The experimental studies on the estrogenic activities of 17alpha-ethynyl-17beta-hydroxy-19-norandrost-4-en-3-one (ENT) (author's transl)].

Today, ENT is a popular synthetic progesteron for clinical use, and is well known to have some estrogenic activity. Estradiol-17beta (E2) or 17alpha-ethynyl estradiol (EE2) binding to the specific protein in the nuclear fraction of hypothalamus were examined by 3H-E2 exchange assay reported by Anderson. The possible mode of the estrogenic actions of ENT are as follows: 1) Conversion of ENT to EE2. 2) Estrogenic of ENT per se without changing the chemical structure. 3) Conversion of ENT to other estrogenic compounds except for EE2. In this experiment, 3H-ENT or 3H-testosterone (3H-T) was incubated with human placental microsomes and NADPH generating system for 1 hr at 37 degrees C, 3H-delta4AD, 3H-T and 3H-ENT were incubated also with homogenates of rat hypothalamus under the same conditions. Isolation and purification of the metabolites were performed by using phenolic separation and paper chromatography. Identification of EE2, a metabolite of ENT, was established by measuring the radiochemical homogenity with the authentic standard on paper chromatography. In another experiment where alkali was not used during the extraction procedure to avoid making artificial products, the conversion rate of ENT to EE2 was measured. This experimental data indicated that ENT was converted to 1beta-OH-ENT and to EE2 by human placental microsomes. The former compound was easily converted to EE2 in the presence of NaOH or by incubation with bile. In the incubation with hypothalamic preparation neither aromatization nor 1beta-hydroxylation of delta4AD, T and ENT were detected. In the exchange assays of E2 receptor, the animals were killed 1 hr after the administration of 25 mug of various steroids. The hypothalamic nuclear fraction was incubated with various 3H-steroids for 30 min at 37 degrees C. After washing this nuclear pellet, the radioactivity was counted. Administration of E2 in vivo resulted in the increase of the amount of 3H-EE2 bound to the nuclear fraction in vitro. But only a small increase of binding was observed in the similar experiment with 3H-ENT. 3H-EE2 was exchanged more abundantly after ENT administration than after EE2 injection. From the above results, it was concluded that the estrogenic effect of ENT is attributed to the EE2 converted in vivo. In addition, a possibility was proposed that ENT or its metabolites other than EE2 could regulate some step in the mechanism of estrogen action.

Androstenedione↗
PubMedDate not supplied

Transplantation of woodchuck hepatocellular carcinoma in nude mice.

Woodchuck hepatocellular carcinoma has been successfully transplanted into nude (athymic) mice. The morphology of heterotransplanted tumor is similar to that of naturally occurring hepatocellular carcinoma before transplantation. The growth rate of transplanted tumor was very slow compared with those of other transplanted tumors. During the first month, only two tumors appeared. However, definitive tumor growth was noted in 6 of 20 nude mice about 3 months later. Seventeen of 20 nude mice exhibited sustained tumor growth after 6 months. The woodchuck hepatocellular carcinoma in nude mice provides an in vivo model for the study of oncogenesis of human hepatocellular carcinoma related to hepatitis B virus.

Animals↗
PubMedDate not supplied

Two small intrahepatic cholangiocarcinomas with different sonographic appearances.

We report on 2 cases of small intrahepatic (or peripheral) cholangiocarcinomas initially detected by sonography and completely resected. The lesions had a peripheral hypoechoic component and a central isoechoic or hyperechoic component. One had posterior acoustic shadowing on sonography, and the other did not. Comparison with pathologic findings in both cases indicated that severe fibrotic changes may have caused the posterior acoustic shadowing. This finding is extremely rare. We found only 1 previously reported case of cholangiocarcinoma accompanied by acoustic shadowing.

Acoustics↗
PubMedDate not supplied

Alzheimer's disease and estrogen.

The preventive effect of estrogen on Alzheimer's disease (AD) has become clear with epidemiological data. Therapeutic effects of estrogen have not yet been established. In this presentation, we report our new basic and clinical data. The estrogen receptor, (ER)alpha, and ERbeta mRNA were investigated in rat brain. Estradiol-17beta (E(2)) treatment following OVX reduced the levels of ERalpha mRNA in the hypothalamus. In the substantia innominata (SI), the number of choline acetyltransferase immunoreacive cells increased significantly in the estrogen treatment rat. The neurons in SI projecting to the forebrain cortex contained ERalpha. Increasing amounts of intracellular calcium, peroxidation, and apoptosis with amyloid beta were suppressed in neuronal cells from rat pheochromocytoma (PC12) cells with E(2). ERalpha cDNA transfected PC 12 cells elaborated more neurite-like processes with E(2). In clinics, we are currently preparing vaginal progesterone tablets, which essentially may concentrate in the endometrium to prevent endometrial cancer, with few general circulation of progesterone inviting less depression. The therapeutic effects of cyclic estrogen, such as its preventive effect, are suggested in these studies, at least on mild AD.

Alzheimer Disease↗
PubMedDate not supplied

Atheroprotective effect of estriol and estrone sulfate on human vascular smooth muscle cells.

In patients with atherosclerosis, fibrosclerotic focuses are induced by multiplication of vascular smooth muscle cells (VSMC), and they are regulated by cytokines and regulators. There have been few reports about the atheroprotective effect of estriol (E(3)). Estrone sulfate (E(1)-S) is the predominant estrogen of conjugated equiline estrogens, which is commonly used in hormone replacement therapy, but it should be hydrolyzed by steroid sulfatase (STS) to enter the cells of target tissues. The purpose of this study was to detect STS in VSMC and to investigate whether E(3) and E(1)-S have atheroprotective effects like E(2). First, we detected the presence of STS mRNA in VSMC by in situ hybridization. We then examined the changes in the expression of mRNAs of cytokines, namely, PDGF-A chain, IL-1, IL-6 and TGF-beta, in VSMC, in the presence and absence of E(3) and estrogens. As a result, the expression of PDGF-A chain, IL-1 and IL-6 mRNAs was suppressed by E(3) (P<0.05 vs control) significantly like E(1)-S and E(2), but that of TGF-beta mRNA was not significantly affected by any estrogen. These results indicate that E(1)-S can be hydrolyzed by STS in VSMC, and that E(3) may regulate the cytokines by suppressing the production of mRNAs. It is suggested that there is a possibility of E(1)-S and E(3) having a direct effect on vessels in atherogenesis.

Arteriosclerosis↗