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Biomedical subjects

H Hoshi

Publications and source records attributed to H Hoshi.

At least 253 records · Page 14Linked to original sources
PubMed1989

Relationship of thallium-201 defect and left ventricular function after dipyridamole infusion.

Tl-201 imaging and first-pass radionuclide ventriculography (RNV) by 4 min infusion of 0.56 mg/kg dipyridamole were performed on 22 patients with coronary artery disease in order to know the relationship of myocardial perfusion and left ventricular function after dipyridamole-infusion, and thereby to define whether Tl-201 defect with dipyridamole could imply myocardial ischemia. Initial and delayed Tl-201 images were divided into anterior, apical, and infero-posterior segments, and segmental perfusion defects were categorized as reversible, fixed and no defect. RNV on the 30-degree right anterior oblique view was also divided into anterior, apical, and infero-posterior wall to be evaluated for regional wall motion by a 5 point score before and after dipyridamole. Changes in left ventricular ejection fraction (LVEF) with dipyridamole were also calculated. Normal responses of regional wall motion and LVEF to dipyridamole were established from the data of 14 normal subjects. Reversible defects were closely associated (69%) with an abnormal response of regional wall motion (score decrease of 1 or more after dipyridamole). Both fixed defects and no defects showed little association with abnormal response of regional wall motion. Moreover, 77% of the patients having reversible-defect segment showed an abnormal response of LVEF (reduction of 3% or more following dipyridamole). However, patients without reversible defect did not show an abnormal response to dipyridamole. These results suggest that dipyridamole-induced Tl-201 defects represent a myocardial ischemia which causes a reduction of ventricular function.

Adult↗
PubMed1989

A histological and experimental study on the fate of an increased number of lymph follicles produced in the mouse popliteal lymph node by exogenous antigen stimulation.

Eight-week-old female C57B1/6 mice were injected with endotoxin LPS and/or other antigens into the left hind footpad, and then the number of lymph follicles in the draining popliteal lymph nodes was examined. In untreated mice each popliteal node contained 10-12 lymph follicles at both 8 and 15 weeks of age. Animals given 50 micrograms of LPS at 8 weeks of age showed an increase in the number of lymph follicles 3 weeks later, but this number returned to normal levels by 15 weeks after the LPS injection. After a 2-micrograms-LPS injection at 23 weeks of age, the number of lymph follicles in the draining lymph node was unchanged, but that in animals given the 2-micrograms-injection 15 weeks after the 50-micrograms-LPS injection was significantly increased. In animals receiving 2 Lf of diphtheria toxoid, instead of the 2-micrograms-LPS, at 15 weeks after a 50-micrograms-LPS injection, the number of lymph follicles per draining node was within the normal range. In one group of mice, the initial injection of 50-micrograms-LPS at 8 weeks of age was followed by injections every third week of several kinds of antigens which had been shown to be ineffective in inducing follicle formation. Here, the number of lymph follicles in the draining popliteal node was kept to significantly increased levels at 25 weeks of age. The present results suggest that, while most lymph follicles normally developing in the lymph node are maintained for a long time under normal conditions, many lymph follicles induced by antigenic challenge have a limited life span and undergo atrophy unless they are periodically activated by additional antigenic stimuli, and that atrophied follicles finally become unable to respond to antigenic stimulation. It is also suggested that antigenic materials which trigger the formation of lymph follicles in the primary challenge can evoke follicle formation more efficiently in the secondary challenge.

Animals↗
PubMed1989

[Sequential changes of the cardiomyopathy in Duchenne muscular dystrophy by 201Tl myocardial SPECT].

201Tl myocardial SPECT was performed to evaluate cardiomyopathy in Duchenne type of progressive muscular dystrophy (DMD). Follow up SPECT images of the same patients were also obtained about 1 year after the first scan. Cases subjected to study were 10 DMD. At the first study the hypoperfusion area of the left ventricular muscle was observed in 6 cases (60%) out of 10. At the second study the hypoperfusion areas became wider and lower in 4 out of 6 cases (66.7%). The new hypoperfusion area which was not demonstrated at the first study was observed at the second study in one case of these cases. These results suggested that the positive rate of cardiomyopathy in DMD by 201Tl myocardial SPECT was high, and 201Tl myocardial SPECT is a useful examination to detect the change of myocardial damage in DMD.

Adolescent↗
PubMed1989

[Cerebral blood flow imaging in patients with moyamoya disease].

The usefulness of IMP-SPECT and rCBF image by 133Xe inhalation method on rCBF in patients with moyamoya disease was studied. Six patients with moyamoya disease were diagnosed by cerebral angiogram, and STA-MCA anastomosis technique and EMS were done to reconstruct the rCBF. Low perfusion areas were detected around the cerebral infarction and hemorrhage and that of anterior and middle cerebral arteries by IMP-SPECT and 133Xe-rCBF image met by X-ray CT. After surgery, 4 out of 6 cases showed the improvement of rCBF by IMP-SPECT and 133Xe-rCBF image, as for clinical symptoms, there were reduction of TIA in 3 cases, and no rehemorrhage in 3 cases. In summary IMP-SPECT and 133Xe-rCBF image may be useful method to evaluate the rCBF in moyamoya disease and the change of rCBF post STA-MCA anastomosis technique and EMS.

Adult↗
PubMed1989

Induction of lymph follicle formation with several mitogens and adjuvants in the mouse popliteal lymph node.

The formation of lymph follicles in draining popliteal nodes was investigated in young adult male mice which had been injected in the rear footpad with several mitogens and adjuvants, and killed after 3-21 days. PPD (100 micrograms-1 mg) and PHA (25-500 micrograms) induced germinal centers in association with existing follicles and mild plasmacytosis, but failed to produce new follicles in draining nodes. Endotoxin LPS (50-200 micrograms), Con A (50 micrograms-1 mg) and PWM (50 micrograms-1 mg) induced germinal centers within existing follicles and plasmacytosis, and also produced new follicles which soon developed germinal centers. Both Freund's complete and incomplete adjuvants (FCA and FICA, 25 microliters) induced virtually no germinal centers and plasmacytosis, but produced a significant number of new primary follicles. Poly (A, U) (600 micrograms) produced neither germinal centers nor plasmacytosis, and did not induce new follicles. Analysis of the distribution of lymphoid cells which had incorporated 3H-thymidine in the draining nodes at 3 days after the injection of test substances indicated that PPD, PHA, LPS, Con A and PWM preferentially stimulated in vivo the same types of lymphocytes as they do in vitro. FCA triggered lymphocyte activation in the deep cortex, whereas Poly (A, U) appeared not to stimulate lymphocytes in vivo. In further experiments, induction of lymph follicles with artificially precipitated PPD and PHA was studied. The draining nodes treated with alum-precipitated PPD or PHA were found to produce a significant number of new follicles.(ABSTRACT TRUNCATED AT 250 WORDS)

Adjuvants, Pharmaceutic↗
PubMed1989

[The evaluation of the bone marrow accumulation of Ga-67 citrate].

The bone marrow distribution of Ga-67 citrate may be influenced by various elements in serum. In order to make these points clear, 1,955 whole body images were reviewed on the relationship between the accumulation of bone marrow and laboratory examination data of each patients. Increasing accumulation in the bone marrow was determined as positive when the bones of lower extremities were deposited on the images, because these bones was not visualized in normal gallium image. Laboratory data of 20 patients without having bone marrow accumulation was used as control. The positive findings of bone marrow accumulation was observed in 38 patients (2%) including 23 malignancies and 15 benign disease. The malignant tumor infiltration to the bone marrow was demonstrated by bone marrow aspiration biopsy in 2 out of 7 patients with bone marrow accumulation of Ga-67. Seven out of 15 patients with benign disease were collagen disease such as aortitis syndrome or SLE. The values of hemoglobin, hematocrit, serum iron and creatinine clearance were significantly lower in the patients with positive findings in comparison with control. These results suggest that the lower level of serum iron and anemia may cause increasing bone marrow accumulation of Ga-67 citrate.

Bone Marrow↗
PubMed1989

[Effect of blockage of the afferent lymphatic vessels on the development of popliteal lymph nodes in the rat].

The effect of blockage of the afferent lymphatic vessels on the development of popliteal lymph nodes in the rat was studied. The afferent lymphatic vessels to each popliteal node were surgically interrupted at the lowest edge of the popliteal fossa at 3, 7 or 28 days after birth and the popliteal nodes were obtained from treated animals at 4, 8 or 16 weeks after the operation. At 7 days after birth, each popliteal node was small and weighed 0.2 mg. Its parenchyma consisted of reticular cells and a small number of dispersed lymphoid elements. Four weeks after birth, each node weighed 4-5 mg, and its parenchyma comprised two layers, an outer continuous layer of peripheral cortex containing 40-50 lymph follicles and an inner discontinuous layer of deep cortex made up of 4-5 deep cortical units. At 10-12 weeks after birth, each node weighed about 10 mg and showed full structural development; the peripheral cortex contained 100-130 lymph follicles and the deep cortex consisted of 4-6 well developed units. The popliteal node was drained by 4-6 afferent lymphatic vessels, which opened into the subcapsular sinus of the node. Each lymphatic opening was topographically associated with a respective deep cortical unit, as previously described by Bélisle and Sainte-Marie (1982). In animals treated at 3 or 7 days after birth, the development of the popliteal nodes was considerably inhibited. Four weeks after surgery, each node showed 10-30 lymph follicles in the peripheral cortex and 1-3 small units in the deep cortex. Sixteen weeks after surgery, the node weighed about 4 mg and its cortex exhibited about 50 lymph follicles in the peripheral cortex and only 2 units in the deep cortex. The popliteal nodes of the treated animals generally received 2 afferent lymphatic vessels. In animals treated at 4 weeks after birth, the popliteal nodes showed no gain in weight for following 16 weeks. Four weeks after surgery, each node usually had 4-5 deep cortical units and 50-60 lymph follicles. Thereafter, some units and their overlaying peripheral cortex underwent atrophy, while others persisted. Sixteen weeks after surgery, the popliteal node showed only 2 deep cortical units and 50-60 lymph follicles, and was drained by 2 afferent lymphatic vessels. Surgical interruption of the afferent lymphatic vessels to the popliteal node at the lowest edge of the popliteal fossa did not obliterate all the draining lymphatic vessels , but reduced the number of vessels opening into the node.(ABSTRACT TRUNCATED AT 400 WORDS)

Animals↗
PubMed1989

[Clinical cerebral perfusion scintigraphy with 123I-IMP].

At the first place, some experimental knowledges on the biodistribution of IMP were described for the understand of this agent. And on the basis of our clinical experience, the usefulness of cerebral perfusion imaging using SPECT and IMP was reviewed. The patients with possible ischemic cerebral diseases such as infarction, TIA and RIND are main candidates for this examination. Clinical significance of the so-called "redistribution" of IMP was discussed in detail. Dementia and epilepsy are considered to be the other indication. With improvement of the method, cerebral perfusion imaging may be accepted as essential test in the hospital dealing with the patient with neuropsychiatric deficits.

Amphetamines↗
PubMed1989

[Therapeutic analysis of autopsy findings in oral cancer].

Thirty-four autopsied patients with oral squamous cell carcinoma were analyzed by multiple regression analysis. The following results were obtained. 1) The suggested metastatic spread was from the highest count of oral cancer patients with metastases in lung to lower key organs, reflecting the cascade theory. 2) Multiple regression analysis revealed that local recurrence was significantly related to the treatment method, indicating that multidisciplinary treatment would be needed. 3) Multiple regression analysis indicated that mediastinal lymph node metastasis was significantly related to both the age of the patient and the stage of cancer development. 4) Multiple regression analysis showed that distant metastasis was significantly related to both the stage and the spleen weight. 5) There were many patients with the pulmonary metastases undergoing irradiation which ranged from 40Gy to 60Gy on the primary tumor. 6) Results showed that immunotherapy tended to control pulmonary metastases.

Adult↗
PubMed1989

Comparative study of regional cerebral blood flow images by SPECT using xenon-133, iodine-123 IMP, and technetium-99m HM-PAO.

Regional cerebral blood flow (rCBF) was measured by single photon emission computed tomography (SPECT) using 133Xe, N-isopropyl-p-[123I]iodoamphetamine ([123I]IMP) and [99mTc] hexamethylpropyleneamine oxime ([99mTc]HM-PAO) in 24 patients with cerebrovascular diseases. The greatest advantage of 133Xe SPECT was to be able to provide absolute rCBF values without arterial sampling. However, its image quality was very poor. Iodine-123 IMP SPECT provided rCBF images of higher quality and it had good correlation to 133Xe SPECT. Iodine-123 IMP SPECT provided the best images to detect mild ischemic lesions. It could detect obstructive or stenotic changes of large cerebral arteries very well except for a moderate stenosis of internal carotid artery. Technetium-99m HM-PAO SPECT also provided very good rCBF images and it had good correlation to 133Xe SPECT. However, the count-density ratios for the ischemic lesions to the contralateral presumed normal areas of [99mTc] HM-PAO SPECT were significantly higher than those of [123I]IMP SPECT.

Adult↗
PubMed1989

Critical cerebral blood flow thresholds studied by SPECT using xenon-133 and iodine-123 iodoamphetamine.

Regional cerebral blood flow (rCBF) was assessed in patients with cerebrovascular diseases (CVD) by single photon emission computed tomography (SPECT) using 133Xe and N-isopropyl-p-[123I]iodoamphetamine ([123I]IMP). The purpose of this study was to determine the infarcted and symptomatic blood flow thresholds of cerebral cortex by SPECT. In the 133Xe inhalation method rCBF was calculated by employing the Celsis modification of the Kanno and Lassen algorithm. In the [123I]IMP SPECT quantitation was obtained by counting-rate ratio for the low flow lesion to the contralateral homologous region which was presumed to be normal (Lesion/Normal ratio, L/N ratio). The infarcted and symptomatic blood flow thresholds by 133Xe SPECT was 19-23 and 33-36 ml/100 g/min, respectively. While, those of L/N ratio in the [123I]IMP SPECT were 39-48 and 65-72%, respectively. There was a significant correlation between the ischemic degrees evaluated by 133Xe and [123I]IMP SPECT studies.

Adolescent↗
PubMed1989

Dynamic SPECT with technetium-99m HM-PAO in meningiomas--a comparison with iodine-123 IMP.

Technetium-99m hexamethylpropyleneamine oxime ([99mTc]HM-PAO) has recently been introduced as an alternative to N-isopropyl-p-[123I]iodoamphetamine ([123I]IMP) for measurement of regional cerebral blood flow. This study compares dynamic SPECT studies using the two tracers in seven patients with meningiomas. Regions of interest were placed over the lesion and contralateral homologous presumed normal area. The counting-rate ratio for the lesion to the contralateral homologous area (L/N ratio) was then calculated in the first image. L/N ratios of [99mTc]HM-PAO single photon emission computed tomography (SPECT) were lower than those of [123I])IMP SPECT, particularly in hypervascular meningiomas. Furthermore, time-activity curves showed that the washout of [99mTc]HM-PAO in the tumors was very slow or incomplete, preventing an accurate assessment of vascularity of meningiomas with [99mTc]HM-PAO, as is generally possible with [123I]IMP.

Adult↗
PubMed1989

[Detection of coronary artery disease by exercise radionuclide ventriculography: using sector analysis].

Exercise first-pass radionuclide ventriculography was performed on 65 patients with coronary artery disease (CAD) and 18 control subjects with normal coronary artery, Left ventricle (LV) was divided into 5 sectors in radial, and volume curves were generated for whole LV and each sector for estimating LVEF and time to end systole (TES). The differences of TES between whole LV and each sector were calculated and these 5 differences were averaged (Variation of TES). We defined this Variation of TES as an index of LV asynchrony, and used for detection of CAD. The overall sensitivity and specificity for identifying CAD were 63% and 83% (LVEF during exercise), 51% and 83% (delta LVEF). Variation of TES during exercise had a sensitivity and a specificity of 88% and 83%, and was more sensitive than both LVEF during exercise and delta LVEF (p less than 0.01). In conclusion, Variation of TES was a good marker of LV asynchrony and useful for the detection of CAD.

Coronary Disease↗
PubMed1988

Managing diabetic surgical patients with glucose-free saline and insulin.

Sixty-one people with glucose intolerance received a glucose-free solution during surgery. If their blood glucose levels rose above 200 mg/dl, they were given insulin intravenously, according to a rate algorithm reported elsewhere. None of the cases judged to be borderline required any insulin during their operations. Ten percent of the diabetics who were being treated with diet alone, and 40% of those using hypoglycemic agents or insulin, did require insulin. Insulin was delivered at an average rate of 2.1 +/- 5.2 U/h and controlled the serum glucose levels within a range of 132 +/- 32 mg/dl. This suggests that half of all diabetics undergoing surgery require only a glucose-free solution for fluid replacement to maintain their glucose levels below 200 mg/dl, and that insulin infusion is an appropriate means to control hyperglycemia during surgery.

Blood Glucose↗
PubMed1988

High and low affinity binding of heparin-binding growth factor to a 130-kDa receptor correlates with stimulation and inhibition of growth of a differentiated human hepatoma cell.

The differentiated human hepatoblastoma-derived cell line, HepG2, displayed two classes of specific membrane receptors for heparin-binding growth factor type 1 (HBGF-1). Specific membrane receptors were distinguished from nonreceptor heparin-like binding sites. Receptors with an apparent Kd of 9.2 +/- 0.9 pM and present at 15,000 +/- 900/cell correlated with HBGF-1 stimulation of HepG2 growth. Receptors with an apparent Kd of 2 +/- 0.4 nM and present at 180,000 +/- 18,000/cell correlated with inhibition of growth and changes in secretory products. Other hepatoma cell lines exhibited a simple positive mitogenic response to HBGF-1 and a single class of high affinity binding sites. HBGF-1 covalently cross-linked to hepatoma cell surface polypeptides of apparent mean molecular mass of 130 kilodaltons. At 37 degrees C, receptor-bound HBGF-1 was internalized (t 1/2 = 45 min) but not degraded for up to 6 h. The display of receptors decreased with increased cell density and expression of HBGF-1 mRNA and HBGF-1-like activity in the culture medium. Proliferating normal human hepatocytes also exhibited two classes of binding sites with affinities for HBGF-1 and apparent molecular weight similar to HepG2 cells. These results implicate HBGF-1 or homologues in human hepatoma cell growth and normal liver cell regeneration.

Carcinoma, Hepatocellular↗
PubMed1988

Gallium scintigraphy in patients with adult T-cell leukemia lymphoma.

Gallium scintigraphy was evaluated in 25 patients with adult T-cell leukemia lymphoma (ATLL). Anterior and posterior images were obtained at 72 h after administration of 3 mCi 67Ga-citrate using a gamma camera (Maxi-Camera 400 T, General Electric Co.) with a medium energy standard parallel hole collimator. Abnormally high accumulations were observed in 17 out of 25 cases (superficial lymph node, 8; hilar and mediastinal lymph node, 7; paraaortic lymph node, 2; lung, 9; liver, 1; bone, 1). There were 10 malignant lesions detected by 67Ga scintigraphy in 9 out of 17 cases (superficial lymph node, 1; hilar and mediastinal lymph node, 6; paraaortic lymph node, 1; liver, 1; bone, 1). White blood cell count and serum LDH levels were raised in patients with abnormally high accumulations of 67Ga. In conclusion, 67Ga scintigraphy seemed to be a useful examination to detect malignant lesions in patients with ATLL.

Female↗
PubMed1988

Early and delayed single photon emission CT in various cerebral diseases using N-isopropyl-p-(123I)iodoamphetamine.

Early and delayed single photon emission computed tomography (SPECT) using N-isopropyl-p-(123I)iodoamphetamine (IMP) was performed on 28 subjects (2 normal, 12 with cerebrovascular diseases and 14 with brain tumors) to evaluate the reversibility of the cerebral abnormality and cerebral viability. The results were compared with X-ray CT, 99mTc brain scintigraphy and rCBF by 133Xe inhalation method. Three types of IMP kinetics were observed. Initial hypoactivity that changed over 4 to 6 hours approaching a normal pattern suggests a hypofunctional parenchyma without significant tissue damage: long-lasting abnormalities on IMP SPECT indicates cellular damage.

Adolescent↗