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Biomedical subjects

H Hoshi

Publications and source records attributed to H Hoshi.

At least 217 records · Page 12Linked to original sources
PubMed1992

Development of early bovine embryos to the blastocyst stage in serum-free conditioned medium from bovine granulosa cells.

Bovine granulosa cell-conditioned medium (BGC-CM) was prepared in a serum-free medium consisting of TCM 199, 5 micrograms/ml insulin, and 0.5 micrograms/ml aprotinin (TCM 199 IAP). Granulosa cells surrounded with embryos were denuded 24 to 30 h after in vitro fertilization. The proportion of denuded granulosa cell-free embryos that developed to the blastocyst stage in BGC-CM (43/219; 20%) as well as in the co-culture system (43/178; 24%) was significantly greater (P less than 0.001) than in fresh TCM 199 IAP medium (FM: 10/191; 5%), whereas the proportion of embryos that developed to the eight-cell stage was similar (P greater than 0.05) in all three culture systems (95/178; 53% in co-culture, 111/219; 51% in BGC-CM, and 86/191; 45% in FM, respectively). Higher rates of hatching and hatched blastocysts 8.5 days after in vitro fertilization were observed in co-culture (13/44; 29.5%) and in conditioned medium (8/39; 20.5%). On the other hand, no hatching or hatched blastocysts were obtained in the fresh medium (0/7; 0%). Cell numbers per blastocyst in BGC-CM (178.3 cells/blastocyst) were approximately two-fold higher than those in FM (97.1 cells/blastocyst). However, higher cell numbers (249.3 cells/blastocyst) were observed in co-culture with BGC than in BGC-CM. The embryotrophic activity in BGC-CM was stable upon freezing and thawing, lyophilization, and heating at 56 degrees C whereas activity was reduced by dilution in fresh medium, dialysis, pronase digestion, and heating at 80 degrees C. These results suggest that BGC cultured in a serum-free medium can synthesize and secrete an embryotrophic factor(s) that supports blastocyst formation in vitro beyond the 8- to 16-cell stage.

Animals↗
PubMed1992

Lung scintigraphy with [123I]IMP in patients with pulmonary tuberculosis.

Lung scintigraphy using N-isopropyl-p-[123I]iodoamphetamine (IMP) was performed on 26 patients with pulmonary tuberculosis. Early (5 min after injection) and late images (4 h after injection) were obtained with a large-field gamma-camera equipped with a digital computer. Lung scintigraphy using [99mTc]MAA (MAA) was also done. Although early IMP images showed the same findings as [99mTc]MAA, images, a discrepancy between delayed IMP images and [99mTc]MAA images was seen in some patients. Increment of activities seen in late images was demonstrated in most patients whose chest x-ray findings included exudative inflammatory changes. Uptake and clearance of IMP was considered to be affected by the active phase of pulmonary tuberculosis.

Adult↗
PubMed1992

Early and delayed imaging of Tc-99m HMPAO versus Tl-201 in benign and malignant thyroid tumors. Similar uptake but different retention.

The authors performed both Tc-99m HMPAO and Tl-201 scintigraphy in 30 patients with thyroid tumors (21 papillary adenocarcinoma, three solid follicular adenoma, six adenomatous goiter with cystic degeneration). Increased accumulation of both Tc-99m HMPAO and Tl-201 was seen in 14 patients with papillary adenocarcinoma and three with solid follicular adenoma, whereas two patients with papillar adenocarcinoma had low accumulation of both tracers. Of the six patients with adenomatous goiter with cystic degeneration, four had low accumulation of both Tc-99m HMPAO and Tl-201, and one patient had low accumulation of Tc-99m HMPAO only. Iso accumulation (same accumulation as the normal thyroid) of Tc-99m HMPAO was seen in five patients with papillary adenocarcinoma and one with adenomatous goiter. The distribution of Tc-99m HMPAO in the thyroid tumors and normal thyroid tissue was independent of time from 2 to 120 minutes after injection. The results of dynamic studies using Tc-99m HMPAO suggested that the accumulation of Tc-99m HMPAO in thyroid tumors reflected mainly tumor blood flow. The resultant Tc-99m HMPAO images were essentially similar to the Tl-201 images obtained 10 minutes after injection. Tc-99m HMPAO imaging can be a suitable substitute for Tl-201 imaging, and it may possibly be used to estimate tumor blood flow in patients with thyroid tumors.

Adenocarcinoma, Papillary↗
PubMed1992

Lymph follicles and germinal centers in popliteal lymph nodes and other lymphoid tissues of germ-free and conventional rats.

A study was conducted to evaluate the influence of natural exogenous antigen stimulation on the development of lymph follicles in the peripheral lymphoid organs of the rat. The number of lymph follicles and germinal centers per popliteal node as well as the morphological features of popliteal nodes, mesenteric nodes and Peyer's patches were compared between 8-week-old male Sprague-Dawley rats reared in germ-free, specific pathogen-free (SPF) and conventional environments. In mesenteric nodes and Peyer's patches from conventional and SPF rats, almost every follicle contained a germinal center. In the mesenteric nodes from germ-free rats, only 9 of 195 lymph follicles examined contained a germinal center, but interestingly, in Peyer's patches all the lymph follicles examined showed a fairly well developed germinal center. The popliteal nodes from germ-free rats had no germinal centers and each node contained about 80 lymph follicles. In six conventional rats and two of five SPF rats used, the number of lymph follicles per popliteal node usually ranged from 100 to 130, and some lymph follicles contained a germinal center. However, in the other three SPF rats the popliteal node on both sides showed no germinal center, and each contained almost the same number of lymph follicles as the popliteal nodes of other SPF and conventional rats. The present results are consistent with the view that even in the absence of exogenous antigen stimulation, a regional lymph node of the germ-free rat develops a substantial number of primary lymph follicles by way of a non-immunological cellular activity, and that natural exogenous antigens may influence the development of lymph follicles by stimulating the cellular activity rather than evoking the humoral immune responses.

Animals↗
PubMed1992

Synthesis and antifungal activities of pradimicin derivatives, modification at C4'-position.

The 4'-N-alkyl(1 approximately 10) and 4'-N-acyl derivatives (11 approximately 21) of pradimicins (PRMs) were synthesized by trimethylsilylation of PRMs A, C and FA-1 followed by condensation with appropriate alkylating and acylating agents. The 4'-hydroxy derivatives (23 and 24) were synthesized from PRM FA-2 in a 3-step sequence. Among these compounds, the 4'-N-carboxyl substituted alkyl (1, 5, 8 and 10), 4'-N-formyl (11) and 4'-axial-hydroxy (23) derivatives retained the antifungal activity of the parent compounds and showed great improvement in water solubility.

Anthracyclines↗
PubMed1991

Stimulation of human arterial smooth muscle cell chondroitin sulfate proteoglycan synthesis by transforming growth factor-beta.

Human platelet-derived transforming growth factor-beta (TGF-beta) is a cell-type specific promotor of proteoglycan synthesis in human adult arterial cells. Cultured human adult arterial smooth muscle cells synthesized chondroitin sulfate, dermatan sulfate, and heparan sulfate proteoglycans, and the percent composition of these three proteoglycan subclasses varied to some extent from cell strain to cell strain. However, TGF-beta consistently stimulated the synthesis of chondroitin sulfate proteoglycan. Both chondroitin 4- and chondroitin 6-sulfate were stimulated by TGF-beta to the same extent. TGF-beta had no stimulatory effect on either class of [35S]sulfate-labeled proteoglycans which appeared in an approximately 1:1 and 2:1 ratio of heparan sulfate to dermatan sulfate of the medium and cell layers, respectively, of arterial endothelial cells. Human adult arterial endothelial cells synthesized little or no chondroitin sulfate proteoglycan. Pulsechase labeling revealed that the appearance of smooth muscle cell proteoglycans into the medium over a 36-h period equaled the disappearance of labeled proteoglycans from the cell layer, independent of TGF-beta. Inhibitors of RNA synthesis blocked TGF-beta-stimulated proteoglycan synthesis in the smooth muscle cells. The incorporation of [35S]methionine into chondroitin sulfate proteoglycan core proteins was stimulated by TGF-beta. Taken together, the results presented indicate that TGF-beta stimulates chondroitin sulfate proteoglycan synthesis in human adult arterial smooth muscle cells by promoting the core protein synthesis.

Adult↗
PubMed1991

Growth requirements and long-term subcultivation of bovine granulosa cells cultured in a serum-free medium.

We have developed an improved serum-free medium to optimize the cell growth of bovine granulosa cells. The cells on collagen-coated culture plates proliferated extensively in a nutrient medium supplemented with insulin, heparin binding growth factor-2 (HBGF-2), lipoprotein, and bovine serum albumin (BSA). The cell doubling time at logarithmic phase and final cell density at confluent cultures were equal to those of cultures grown in the presence of medium supplemented with optimal concentration (10%) of fetal bovine serum (FBS). Whereas HBGF-2 or insulin alone had a small mitogenic effect of granulosa cells, lipoprotein or BSA did not. When lipoprotein, BSA, or insulin was added together with HBGF-2, synergistic cell proliferation was observed in all combinations. Insulin or lipoprotein had an additive mitogenic stimulation of these cells in the presence of BSA. After granulosa cells were subcultivated in a serum-containing medium until three generations [8.5 cumulative population doubling level (CPDL)], subsequent subcultivation of the cells in a complete serum-free medium could be achieved up to six generations (14.4 CPDL). These results demonstrate that this serum-free medium can support the optimal cell growth and long-term subcultivation of bovine granulosa cells.

Animals↗
PubMed1991

Endothelin-1 stimulates hypertrophy and contractility of neonatal rat cardiac myocytes in a serum-free medium. II.

The effect of endothelin-1 (ET-1) on rat cardiac myocytes cultured in a serum-free medium was determined. Cardiac myocytes cultured in our medium showed an increased rate of protein synthesis, morphological size, contraction rate, and Ca2+ uptake when ET-1 was added. These actions of ET-1 were inhibited by a protein kinase C inhibitor, H-7. Among these four phenomena, contraction and Ca2+ uptake were inhibited by a Ca2+ channel blocker, nicardipine. Therefore, it is likely that the signal for ET-1 to induce these phenomena is transduced by kinase C, and Ca2+ uptake is related to maintaining a high contraction rate.

1-(5-Isoquinolinesulfonyl)-2-Methylpiperazine↗
PubMed1991

The relationship between chest pain during thallium-201 scintigraphy with dipyridamole and myocardial ischemia.

Dipyridamole thallium-201 scintigraphy (DP-Tl) and coronary angiography were studied on 74 patients with suspected coronary artery disease. We compared the clinical features, hemodynamic responses, angiographic results and scintigraphic findings of patients who had chest pain during DP-Tl testing ('chest pain' group) with those of patients who did not have chest pain ('no pain' group). Thirty eight (51%) of the 74 patients developed chest pain. Heart rate and rate pressure product during DP infusion of 'chest pain' group were greater than those of the 'no pain' group (p less than 0.05). Ischemic ST depression was more frequently observed among 'chest pain' patients (p less than 0.01). There were no differences in angiographic severity of coronary artery disease between 'chest pain' and 'no pain' group. Also, we could find no differences in extent and severity scores of perfusion defects and washout abnormalities between the two groups. However, when patients with myocardial infarction were excluded, the 'chest pain' group had significantly greater extent and severity scores of washout abnormalities than the 'no pain' group (extent score: 38 +/- 8 vs 18 +/- 5, p less than 0.05, severity score: 55 +/- 15 vs 18 +/- 7, p less than 0.01). Our study indicated that in patients without myocardial infarction, patients with 'chest pain' had more severe ischemia than 'no pain' patients. But in patients with myocardial infarction, myocardial ischemia not accompanied by chest pain might be as severe as that with chest pain. The presence or absence of myocardial infarction might have great influence on results regarding the relation of chest pain to myocardial ischemia.

Adult↗
PubMed1991

Synthesis and biological activity of 1-N-[4-(substituted)amidino and guanidino-2-hydroxybutyryl]kanamycins A and B.

The synthesis and biological properties of 1-N-[4-(substituted)amidino and guanidino-2-hydroxybutyryl]kanamycins A and B are described. Reaction of 3,3",6'-tri-N-tert-butoxycarbonyl-amikacin with an appropriate amidinating or guanidinating reagent and subsequent deblocking gave a series of amikacin derivatives having an amidino or guanidino group on the 4"'-position. The corresponding kanamycin B analogs were also prepared by a similar procedure. Among these derivatives, 1-N-(4-formamidino- and guanidino-2-hydroxybutyryl)kanamycins A (7a and 7k) and B (11 and 14) exhibited antibacterial activity similar to the corresponding 4-amino analogs. The nephrotoxic potential of selected compounds is also briefly discussed.

Animals↗
PubMed1991

Pentavalent technetium-99m-DMSA uptake in a patient having multiple myeloma without amyloidosis.

A pentavalent 99mTc-dimercaptosuccinic acid (DMSA) scan was performed on a patient with multiple myeloma without amyloidosis. A high accumulation of the tracer was found in numerous tumors. We believe that the accumulation of DMSA is unrelated to amyloidosis and that the DMSA scan may have potential for the staging of tumors in patients presenting with multiple myeloma.

Bone Neoplasms↗
PubMed1991

[Detection of the new tumor marker MUSE 11 antigen in sera of pancreatic cancer patients: a comparison with sialyl SSEA-I antigen].

Using sera from patients with pancreatic cancer and chronic pancreatitis, we measured the level of the adenocarcinoma-associated antigen MUSE 11. A comparative study between levels of MUSE 11 and levels of sialyl SSEA-1 antigen (SLX) was also carried out. With respect to the MUSE 11 antigen, positive incidence was found in 17 out of 26 pancreatic cancer patients (65%), and in 1 out of 13 chronic pancreatitis patients (8%). Similar results were obtained from the assay of SLX levels. However, no correlation was found between the two markers. Out of 9 samples which showed MUSE 11 negative, three were positive for SLX. Out of 13 samples showing SLX negative, seven were positive for MUSE 11. Twenty out of 26 (77%) cases showed positive results for either antigen. These data suggest that the MUSE 11 antigen may be useful for the diagnosis of pancreatic cancers.

Adult↗
PubMed1991

[Usefulness of 123I-IMP SPECT in patients with epilepsy].

N-isopropyl-p-[123I]iodoamphetamine(123I-IMP)SPECT and electroencephalography (EEG) were evaluated in 21 epileptic patients at interictal stage. The findings of 123I-IMP were compared with those of clinical symptoms and EEG. In 11 cases (85%) of 13 patients with the partial seizure, and 6 cases (75%) of 8 patients with the generalized seizure had focal decreased perfusion of 123I-IMP. The mean number of focal decreased perfusion areas were 3.2 locations 1 case. There were no cases that was observed focal increased perfusion. Focal decreased perfusion area of 123I-IMP SPECT findings agreed with the focuses those were inferred from clinical findings in 8 cases (62%) out of 13 patients with the partial seizure, did not agree in 3 cases (23%) and did not detected in 2 cases (15%). Overall abnormality of 123I-IMP SPECT was observed in 17 cases (81%) out of 21 patients, on the other hand abnormality of EEG was observed in 12 cases (57%). 123I-IMP SPECT may provide useful information for evaluating foci in patients with epilepsy.

Adolescent↗
PubMed1990

[Serial changes of the myocardium in patients with Duchenne's muscular dystrophy followed by cardiac nuclear imaging. 5 years' observation].

In order to evaluate the natural course of Duchenne's cardiomyopathy (DMD), 201T1-SPECT and RI cardioangiography with 99mTc-albumin were performed in 14 patients. They were examined once a year for five years except for 6 patients. Hypo-perfusion were observed in both posterior-inferior and anterior wall at 12 years of age and extended to the lateral wall and septum with aging. The degree of cardiac involvement was different in each case. Systolic parameters (LVEF, 1/3 EF, 1/3 ER-mean) tended to decrease with aging from 15 years of age. Diastolic parameters (%EFV, 1/3 FF, 1/3 FR mean) decreased gradually after 16 years of age. Hypokinetic changes of regional wall motion were observed at 15 years of age and they became severely with aging. Although phase delay appeared visually at 16 years of age, standard deviation of phase angle increased from 15 years of age. Follow up studies by 201T1 myocardial SPECT and gated pool scintigraphy revealed well the progression of cardiac involvement in patients with DMD.

Adolescent↗
PubMed1990

Endothelin stimulates hypertrophy and contractility of neonatal rat cardiac myocytes in a serum-free medium.

The effect of endothelin (ET) on rat cardiac myocytes cultured in a serum-free, defined medium was determined. ET simulated cardiac myocyte hypertrophy in a dose-dependent manner as determined by the protein synthesis and cell surface area. Since the myocyte hypertrophy was abolished by H-7, a protein kinase C inhibitor, ET-receptor mediated protein kinase C activation may be involved in cardiac myocyte hypertrophy. At the same time, ET also stimulated myocyte contractility in this medium, and this stimulatory effect was inhibited by nicardipine. This result indicates that the influx of extracellular calcium ion is necessary for the stimulation of contractility induced by ET.

1-(5-Isoquinolinesulfonyl)-2-Methylpiperazine↗