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Biomedical subjects

H Hoshi

Publications and source records attributed to H Hoshi.

At least 289 records · Page 16Linked to original sources
PubMed1988

The distribution of radioiodine-labeled N-isopropyl-p-iodoamphetamine in permanently ischemic brain of the Mongolian gerbil.

In a study of the distribution of N-isopropyl-p-131I-iodoamphetamine (IMP) in the permanently ischemic brain of 35 mongolian gerbils, the right common carotid artery was ligated under ether anesthesia. After given time intervals, 1.35 MBq (50 microCi) of IMP was injected into 17 gerbils which had severe neurological symptoms, and into 3 normal gerbils for controls. One minute there after each gerbil was sacrificed and brain autoradiography was performed. The activity of IMP in various parts of the brain was calculated from each autoradiogram. Low perfusion areas were observed in the right cerebral hemisphere and the brain stem (5-25% of normal value) from the first minute up to 24 h after ligation. In addition, low perfusion areas were also observed in the left cerebral hemisphere (40-60% of normal value) which represented a remote effect. These results suggest the usefulness of IMP for demonstrating cerebral ischemia and diaschisis.

Amphetamines↗
PubMed1987

The distribution of N-isopropyl-p-iodoamphetamine in temporary ischemic brain of the mongolian gerbil.

We studied the distribution of N-isopropyl-p-[131I]-iodoamphetamine (IMP) in the ischemic brain of 44 mongolian gerbils. The right common carotid artery was temporarily occluded by a clip and recirculated 3 h later. After given time intervals, 50 microCi of IMP was injected into 18 gerbils which had symptoms. One min after injection (or 10 min, 1 h, or 6 h after injection in other gerbils), each gerbil was killed and autoradiography was performed. IMP activity in various parts of the brain was calculated as %Dose/g from each autoradiogram. At one min after recirculation, partial no flow phenomenon was observed in the right cerebral hemisphere. From 10 min to 24 h after recirculation, a high uptake region was observed partially in the right cerebral hemisphere and thalamus. The high activity disappeared rapidly 10 min after injection. It seemed that this high uptake indicated luxury perfusion at the location of severe tissue damage. In the left side, the low perfusion recovered to an almost normal value at one to three days after recirculation. These results suggested the possibility that IMP could demonstrate luxury perfusion and diaschisis.

Amphetamines↗
PubMed1987

Direct analysis of growth factor requirements for isolated human fetal hepatocytes.

Hepatocytes were isolated from human fetal liver in order to analyze the direct effects of growth factors and hormones on human hepatocyte proliferation and function. Mechanical fragmentation and then dissociation of fetal liver tissue with a collagenase/dispase mixture resulted in high yield and viability of hepatocytes. Hepatocytes were selected in arginine-free, ornithine-supplemented medium and defined by morphology, albumin production and ornithine uptake into cellular protein. A screen of over twenty growth factors, hormones, mitogenic agents and crude organ and cell extracts for effect on the stimulation of hepatocyte growth revealed that EGF, insulin, dexamethasone, and factors concentrated in bovine neural extract and hepatoma cell-conditioned medium supported attachment, maintenance and growth of hepatocytes on a collagen-coated substratum. The population of cells selected and defined as differentiated hepatocytes had a proliferative potential of about 4 cumulative population doublings. EGF and insulin synergistically stimulated DNA synthesis in the absence of other hormones and growth factors. Although neural extracts enhanced hepatocyte number, no effect on DNA synthesis of neural extracts or purified heparin-binding growth factors from neural extracts could be demonstrated in the absence or presence of defined hormones, hepatoma-conditioned medium or serum. Hepatoma cell-conditioned medium had the largest impact on both hepatocyte cell number and DNA synthesis under all conditions. Dialyzed serum protein (1 mg/ml) at 10 times higher protein concentration had a similar effect to hepatoma cell-conditioned medium (100 micrograms/ml). The results suggest that hepatoma cell conditioned medium may be a concentrated and less complicated source than serum for purification and characterization of additional normal hepatocyte growth factors.

Albumins↗
PubMed1987

Transforming growth factor type beta specifically stimulates synthesis of proteoglycan in human adult arterial smooth muscle cells.

Myo-intimal proteoglycan metabolism is thought to be important in blood vessel homeostasis, blood clotting, atherogenesis, and atherosclerosis. Human platelet-derived transforming growth factor type beta (TGF-beta) specifically stimulated synthesis of at least two types of chondroitin sulfate proteoglycans in nonproliferating human adult arterial smooth muscle cells in culture. Stimulation of smooth muscle cell proteoglycan synthesis by smooth muscle cell growth promoters (epidermal growth factor, platelet-derived growth factor, and heparin-binding growth factors) was less than 20% of that elicited by TGF-beta. TGF-beta neither significantly stimulated proliferation of quiescent smooth muscle cells nor inhibited proliferating cells. The extent of TGF-beta stimulation of smooth muscle cell proteoglycan synthesis was similar in both nonproliferating and growth-stimulated cells. TGF-beta, which is a reversible inhibitor of endothelial cell proliferation, had no comparable effect on endothelial cell proteoglycan synthesis. These results are consistent with the hypothesis that TGF-beta is a cell-type-specific regulator of proteoglycan synthesis in human blood vessels and may contribute to the myo-intimal accumulation of proteoglycan in atherosclerotic lesions.

Adult↗
PubMed1987

Hyperventilation thallium-201 myocardial imaging for the diagnosis of vasospastic angina.

In seven patients with vasospastic angina, a transient myocardial perfusion defect was demonstrated on Tl-201 myocardial imaging after hyperventilation (HV). The development of spasm on one or more coronary arteries after HV was confirmed by later coronary arteriographic studies, with the perfusing area of the coronary arteries being compatible with the scintigraphic location of the defect. Repeated 12-lead electrocardiograms failed to establish the diagnosis in one of the seven patients. It is concluded that HV Tl-201 myocardial imaging provides invaluable information in establishing a diagnosis of vasospastic angina.

Adult↗
PubMed1987

Mismatch between iodine-123 IMP and technetium-99m HM-PAO brain perfusion imaging in a patient with meningioma.

The discrepancy between three methods for cerebral perfusion imagings in the case of a man with meningioma is presented. Imaging with N-isopropyl-P-[I-123] iodoamphetamine (IMP) showed no activity in the tumor. Imaging with Tc-99m hexamethylpropyleneamine oxime (HM-PAO) and the local cerebral blood flow (LCBF) image with Xe-133 inhalation showed high tumor activity. IMP is a more accurate method for imaging the brain tissue blood flow.

Amphetamines↗
PubMed1987

Technetium-99m serum albumin measurement of gastrointestinal protein loss in a subtotal gastrectomy patient with giant hypertrophic gastritis.

Gastrointestinal protein loss was measured using Tc-99m labeled human serum albumin in a patient with giant hypertrophic gastritis. Gastric secretion was aspirated via a nasogastric tube and measured for radioactivity after intravenous injection of Tc-99m albumin. Assessment of radioactivity of the collected gastric secretion yielded a total radiocount of 98.7 kilocounts per minute within 6 hours, which is equivalent to 1.1% of the total dose. Therefore, at least 1.1% of the circulating albumin was excreted into the gastric cavity within 6 hours, and, since simultaneous abdominal imaging did not demonstrate obvious accumulation of tracer in the gastrointestinal tract, protein loss was thought to be due to giant gastric rugae of the resected stomach. It was concluded that Tc-99m albumin is a valuable means for detection of the site of protein loss in patients with protein-losing gastroenteropathy. This method has several advantages in the clinical setting; it is less time consuming, easy to perform, and provides quantitative and qualitative assessment of protein loss.

Female↗
PubMed1987

Determination of the hypertrophic site of the left ventricle by body surface mapping in patients with hypertension.

To estimate the hypertrophic sites of the left ventricle by body surface mapping (MAP), we performed MAP in 55 patients with hypertension and compared the MAP data with echocardiographic findings. MAP data were analyzed using the departure map technique reported by Flowers et al. The mean and standard deviation (SD) of the normal control were obtained from 40 normal volunteers. We constructed departure maps at 20, 30, 40, 50 and 60 msec from the onset of the QRS. Each map indicates the area of abnormally increased potential outside the normal range at the time. Subjects were classified into 5 groups according to the appearance time of the abnormal positive area. Septal thickness was significantly increased in groups that had an abnormal positive area at 20 msec, and left ventricular posterior wall thickness was significantly increased in the groups that had an abnormal positive area at 60 msec. We postulate that the increased electrical potential due to hypertrophy of the interventricular septum is represented by the abnormal positive area at 20 msec, and the increased potential of the left ventricular posterior wall by the abnormal positive area at 60 msec. MAP, especially the departure map technique, is a useful method to detect the abnormal electrical potential distribution in patients with left ventricular hypertrophy.

Adult↗
PubMed1987

[Clinical evaluation of serum neuron-specific enolase levels in patients with lung cancer].

Serum neuron-specific enolase (NSE) levels were studied in 105 patients with malignant neoplasms (lung cancer 38, others 67), 13 patients with various benign diseases and 7 healthy adults. The mean serum NSE level in adult control subjects was 7.4 +/- 0.8 ng/ml, and cut off level was decided 10 ng/ml. Serum NSE levels were elevated in 14/38 (37%) of patients with lung cancer and in 14/67 (21%) of patients with the other malignant neoplasms. In patients with benign diseases, serum NSE level was elevated only in one patient with pituitary adenoma. In 7 patients with small cell lung cancer, the positive rate was higher (86%) than in those with non-small cell lung cancer (26%), and serum NSE levels were higher than 25 ng/ml except one case. There was no correlation between serum NSE and CEA (carcinoembryonic antigen) levels in patients with small cell lung cancer, also in patients with lung cancer. The measurement of serum NSE level seemed to be useful for diagnosis in patients with small cell lung cancer.

Adult↗
PubMed1987

Synthesis and structure-activity relationships of a new oral cephalosporin, BMY-28100 and related compounds.

The synthesis and structure-activity relationships of 7-[D-alpha-amino-alpha-(4-hydroxyphenyl)-acetamido]-3-[(Z)-1-propenyl]- 3-cephem-4-carboxylic acid (BMY-28100) and its analogs in the 3- and 7-side chains are described. The 3-(substituted-propenyl) groups were introduced by the Wittig reaction of the 3-phosphoniomethyl cephems which were derived from the 3-chloromethyl derivatives. The reaction gave predominantly the cis isomer regarding the 3-side chain. The cis and trans isomers showed characteristic UV and 1H NMR spectra. Most of cephems of this series were well-absorbed orally and more active both in vitro and in vivo than cephalexin and cefaclor against Gram-positive organisms. Their Gram-negative activity varied depending on the 3- and 7-substituents. Compounds with a cis-propenyl group showed the best Gram-negative activity among the 3-alkenyl analogs prepared, whereas the D-4-hydroxyphenylglycyl and D-4-hydroxy-3-methoxyphenylglycyl substitutions in the 7-side chain were found suitable to improve the Gram-negative activity of 3-cis-propenyl series of cephalosporins to the level favorably compared with that of cefaclor. The 3,4-dihydroxyphenyl analog was found to be metabolized in vivo to the 4-hydroxy-3-methoxyphenyl derivative and, therefore, showed nearly the same in vivo activity as that of the latter. BMY-28100 was selected for further evaluation and the results will be reported in the subsequent paper.

Animals↗