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Biomedical subjects

H Saitoh

Publications and source records attributed to H Saitoh.

At least 253 records · Page 14Linked to original sources
PubMed1994

[Efficacy of lidocaine cardioplegia for spontaneous resumption of heart beating].

Efficacy of lidocaine for cardiac rhythms after aortic declamping was evaluated retrospectively. Twenty-four patients undergoing coronary artery bypass grafting (CABG) (Group C1) and seven patients undergoing aortic or mitral valve replacement (VR) (Group V1) received crystalloid cardioplegia without lidocaine, while 21 patients undergoing CABG (Group C2) and 19 patients undergoing VR (Group V2) received lidocaine (50 mg/l) added crystalloid cardioplegia. After aortic declamping, there was a significant increase in spontaneous resumption of heart beating in Group C2 (71.4%) and Group V2 (57.9%), as compared with their respective counterparts, Group C1 (4.2%) and Group V1 (0%). Mean attempts of electrical defibrillation were significantly decreased in Group C2 (one time) and Group V2 (1.33 times), while electrical defibrillation was required 1.74 times in Group C1 and 2.71 times in Group V1. The present study suggests that lidocaine cardioplegia increases spontaneous defibrillation and decreases the need of electrical defibrillation.

Adult↗
PubMed1994

Establishment of a new cell line with the characteristics of a multipotential progenitor from a patient with chronic myelogenous leukemia in early erythroblastic crisis.

A novel cell line (KH88) was established from a patient with chronic myelogenous leukemia in blastic crisis. The leukemic blasts had the features of undifferentiated blasts with basophilic agranular cytoplasm and they were focally positive for acid phosphatase and alpha-naphthyl acetate esterase. CD36, CD33, HLADR, and CD71 were expressed on the surfaces of the blast cells. Most blasts were positive for platelet peroxidase activity, and some of them had granules containing aggregates of ferritin molecules. These findings were compatible with those of 'early' erythroblastic leukemia, this established cell line (KH88) having similar characteristics, and actually producing hemoglobin A and hemoglobin F. Although the KH88 cells were negative for megakaryocytic markers, they were induced to express CD41 by phorbol ester. Further, a few KH88 cells were positive for myeloperoxidase. This cell line was thus revealed to have the capacity to differentiate into three lineages, providing a useful model for studying the differentiation of multipotential stem cells. Moreover, a subline of KH88 had a peculiar chromosome abnormality, del(3)(q21q25); it would be useful to study the significance of this chromosomal abnormality.

Aged↗
PubMed1993

[A study with diagnostic standard of occult hyperprolactinemia (OHP) and the effect of bromocriptine administration].

It is well known that the transient excessive increase of serum prolactin level is harmful for the mechanism of ovulation or the steroidogenesis of the ovaries. The pathogenesis of latent or occult hyperprolactinemia (OHP) has been investigated recently. The present study was conducted to determine the diagnostic standard of OHP, and to elucidate the efficacy of bromocriptine administration for the treatment of OHP and other ovulatory disturbances. 110 cases of hypothalamic anovulations were selected from 385 cases of infertile patients by the LH-RH and TRH loading tests. Bromocriptine (5mg/day) was administered to all of the subjects for more than three months, and the efficacy of the bromocriptine administration was investigated. Follicular development was observed by transvaginal ultrasonography (mature follicular diameters > or = 20mm), and also luteal function was estimated by the duration of the luteal phase in the BBT charts (high phase > or = 12 days), the mid-luteal serum estradiol (> or = 200pg/ml) and progesterone (> or = 10ng/ml) levels. The subjects were divided into two groups: group A, bromocriptine effective patients (63 cases) and group B, bromocriptine non effective patients (47 cases). The results of the LH-RH and TRH loading tests were compared between these two groups. Serum prolactin levels at 30 min. after TRH loading (PRL30) in group B (61.5 +/- 28.3 vs. 38.0 +/- 19.3ng/ml, p < 0.01). At the cut-off points of 50, 60 and 70ng/ml over in the values of the PRL, the efficacies of the bromocriptine administration were 77.4, 78.9 and 88.5%, respectively. From these facts, it was thought suitable that the diagnostic standard of OHP was PRL30 > or = 70ng/ml, and values of PRL30 from 50 to 70ng/ml were borderline cases of OHP. The efficacy of the bromocriptine administration in the cases without OHP (n = 57) was also investigated. Serum LH levels at 30 min. after LH-RH loading (LH30) were compared between the cases of the bromocriptine effective (n = 22) and non effective (n = 35). As a result, the LH30 of the former was significantly higher than that of the latter (96.5 +/- 64.2 vs. 45.1 +/- 31.5mIU/ml, p < 0.005). In conclusion, the diagnostic standard of OHP was determined as PRL30 > or = 70ng/ml (borderline: 50 > 70ng/ml), and bromocriptine administration was effective not only in cases of OHP, but also in cases of hyperreactivities of LH (so-called endocrinological PCOD).

Anovulation↗
PubMed1993

Transport characteristics of paraquat across rat intestinal brush-border membrane.

The mechanism of absorption of paraquat, which is a type of quaternary ammonium compound (QAC), was studied using rat intestinal loops and brush-border membrane vesicles. Approximately 47% and 37% of radioactively labeled paraquat injected into jejunal and ileal loops disappeared, respectively, after 60 min. Since only a small amount of radioactivity was detected in the mucosal fraction, most of the paraquat that disappeared from the intestinal lumen was considered to have been carried away by the bloodstream, indicating that paraquat absorption was greater than expected. In spite of its low lipid solubility, the uptake of paraquat by brush-border membrane vesicles reflected smooth penetration into the intravesicular space rather than binding to the membrane. According to the increase in extravesicular paraquat concentration, paraquat uptake in the early stage was saturable. Moreover, early paraquat uptake was significantly inhibited by structurally-related QACs such as tetramethylammonium and choline, but not by an endogenous dicationic amine (putrescine). On the other hand, inside-negative membrane potential had no significant effect on the time course of paraquat uptake. From these results, it is suggested that paraquat is absorbed through a specialized mechanism associated with the carrier-mediated transport system for choline on the brush-border membrane.

Animals↗
PubMed1993

W-heterochromatin of chicken; its unusual DNA components, late replication, and chromatin structure.

About 65% of DNA in the chicken W chromosome has been shown to consist of XhoI and EcoRI family repetitive sequences. These sequences showed remarkable delay in the electrophoretic mobility at low temperature on a polyacrylamide gel. Three dimensional structures of the 0.7-kb XhoI and the 1.2-kb EcoRI family repeating units were estimated to be irregular solenoids using a computer program based on wedge angles of all the 16 dinucleotide steps. Fluorescence in situ hybridization demonstrated that these two family sequences were localized in a major heterochromatic body in an interphase nucleus. Incorporation of bromodeoxyuridine into the W chromosome in the synchronous culture of MSB-1 cells occurred about 1 h later than the peak of S phase. The chromatin structure formed along XhoI and EcoRI family sequences was suggested to be different from the total chromatin or chromatin containing the beta-actin gene sequence in that the linker DNA lengths of the former were significantly longer. Fractionation of the HaeIII-digested MSB-1 nuclei yielded a chromatin fraction in which XhoI family sequences were partially enriched. Several DNA-binding proteins showing higher affinity for the XhoI family sequence were present in this fraction.

Actins↗
PubMed1993

Evaluating bronchial drainage pathways in patients with lung disease using digital subtraction angiography.

RATIONALE AND OBJECTIVES: The purpose of the study was to evaluate the venous drainage pathways of the bronchial circulation during bronchial embolotheraphy or infusion therapy. METHODS: The subjects consisted of 21 patients with lung disorders. All of them underwent bronchial arteriography for drug infusion or embolization. Bronchial arteriography was done using both cut-film and digital subtraction methods. RESULTS: The venous drainage pathways of arteriograms could be determined in 15 (71%) patients and classified into the four types: type 1, direct drainage into a pulmonary vein; type 2, drainage into a pulmonary artery with antegrade flow; type 3, drainage into a pulmonary artery with retrograde flow; and type 4, drainage into a bronchial vein. No drainage route could be identified in six (29%) patients. CONCLUSIONS: Digital subtraction angiography can depict the venous drainage pathways in most patients. Drainage occurs into a pulmonary vein in the majority of patients.

Angiography, Digital Subtraction↗
PubMed1993

The transport mechanism of an organic cation, disopyramide, by brush-border membranes. Comparison between renal cortex and small intestine of the rat.

The characteristics of disopyramide uptake in brush-border membrane vesicles isolated from rat renal cortex and small intestine were investigated. Transport of disopyramide into an osmotically reactive intravesicular space was observed with notable binding to the membrane surface. An outwardly directed H+ gradient stimulated disopyramide uptake, resulting in a transient uphill transport in both brush-border membranes. As for the renal brush-border membrane, the H+ gradient itself appeared to be the driving force for this stimulation of uptake. These findings suggest that disopyramide-H+ antiport is the mechanism of disopyramide action in renal cell membrane. The initial uptake was saturable (Km and Vmax of 68.0 microM and 1.25 nmol (mg protein)-1/30 s, respectively). The stimulation of disopyramide uptake by an outward H+ gradient in rat intestinal brush-border membrane was due to an interior negative H(+)-diffusion potential. A K(+)-diffusion potential (interior negative) enhanced disopyramide uptake. These results suggest that there are different mechanisms of disopyramide uptake for renal and intestinal brush-border membrane vesicles.

Animals↗
PubMed1993

Electrical and mechanical alternans in canine myocardium in vivo. Dependence on intracellular calcium cycling.

BACKGROUND: Electrical and mechanical alternans are thought to result from a common cellular mechanism. To confirm this phenomenon in vivo and extend our understanding, we investigated the effects of temperature, verapamil, and caffeine on alternans in intact beating hearts. METHODS AND RESULTS: We recorded surface ECG, monophasic action potential (MAP) using suction electrodes, and left ventricular pressure (LVP). Alternans of MAP configurations and of LVP were evaluated in 20 dogs. MAPs were recorded from the apex, base, and midportion of the left ventricle with LVP. The hearts were driven from the left ventricular apex at a basic cycle length of 1000 milliseconds, and alternans was induced with an abrupt shortening of the cycle length to 400 milliseconds. MAPD30/100, the ratio between the MAP durations (MAPD) at 30% and 100% repolarization levels, was measured as an index of MAP configuration. The magnitude of MAP or LVP alternans was defined as the difference in MAPD30/100 or in LVP between the fifth and sixth paced beats. The magnitude of MAP alternans differed by recording site but correlated with activation time. Lowering the temperature increased the magnitude. MAP alternans was always associated with LVP alternans under control conditions. Verapamil significantly attenuated the magnitude of MAP alternans but did not change that of LVP alternans. Caffeine attenuated the magnitude of both MAP and LVP alternans. T wave alternans was suppressed by verapamil or caffeine. CONCLUSIONS: Activation time is one of the factors modifying electrical alternans. Delayed intracellular Ca2+ cycling plays a role in the concomitant occurrence of electrical and mechanical alternans.

Action Potentials↗
PubMed1993

Intracerebral hemorrhage caused by a neoplastic aneurysm from small-cell lung carcinoma: case report.

A neoplastic cerebral aneurysm from lung cancer is an extremely rare occurrence despite its high metastatic potential to the brain. We report a neoplastic cerebral aneurysm from small-cell lung carcinoma that caused an intracerebral hematoma. A 63-year-old man underwent an urgent craniotomy for a massive intracerebral hematoma. After evacuation of the hematoma, an anomalous artery was found on the wall and a biopsy was done. The histological examination revealed that the artery was filled with neoplastic cells, and a part of the vessel wall was distended, forming an aneurysm. The histological feature of the tumor cells was consistent with small-cell lung carcinoma, which was disclosed in the left hilus.

Aneurysm, Ruptured↗
PubMed1993

KRI-1314: an orally effective inhibitor of human renin.

Biochemical and pharmacological properties of KRI-1314, a newly synthesized, low molecular weight (M.W.: 690) renin inhibitor, were investigated in vitro and in vivo. The novel amino acid norstatine, which is shorter in chain length than the well-known statine, was incorporated into KRI-1314 as a tetrahedral transition-state analogue for the Leu10-Val11 scissile peptide in the renin substrate. KRI-1314 more strongly inhibited plasma renins from primates than those from dogs, rabbits, guinea pigs and rats. KRI-1314 competitively inhibited highly-purified human renin with a Ki value of 9.9 x 10(-10) M. KRI-1314 strongly inhibited the tissue renin-like activities of various organs from Japanese monkeys, with IC50 values on the order of 10(-8) M. KRI-1314 was also very stable in various tissue homogenates from Japanese monkeys. Both intravenous (from 0.25 to 3 mg/kg) and oral (10 and 30 mg/kg) administration of KRI-1314 to anesthetized and conscious sodium-depleted Japanese monkeys, respectively, significantly lowered the blood pressure and plasma renin activity without affecting the heart rate. In Japanese monkeys, KRI-1314 was continuously detected in the plasma up to at least 7 hr after oral administration of 10 and 30 mg/kg. These results demonstrate that KRI-1314 is a highly potent, primate-selective and long-lasting oral renin inhibitor with a blood pressure lowering effect.

Administration, Oral↗
PubMed1993

Case report: radiation-induced vasculopathy implicated by depressed blood flow and metabolism in a pineal glioma.

A case of radiation-induced vasculopathy of a pineal glioma was presented with haemodynamic and metabolic changes before and after radiotherapy. After radiation of 60 Gy with conventional fractionation (1.8-2.0 Gy daily, 5 days per week), regional blood flow, oxygen extraction fraction, metabolic rate of oxygen, kinetic metabolic rate of glucose and the rate constants (K2, K3) were markedly depressed (20% or greater) compared with the pre-irradiated study. 7 months after radiotherapy, the patient developed transient transient episodes of both right and left upper limb convulsion, terminating in generalized convulsion. When she developed status epilepticus, computed tomography showed extensive low density areas in the territory supplied by the right middle cerebral and the right posterior cerebral arteries. Cerebral angiography revealed diffuse stenosis at both carotid bifurcations and at the origins of the right posterior communicating and posterior cerebral arteries. Haemodynamic and metabolic depression therefore implicated radiation-induced vasculopathy in the present case.

Astrocytoma↗
PubMed1993

Primary biliary cirrhosis associated with multiple myeloma.

An association between autoimmune disease and malignancy, in particular lymphoproliferative neoplasms, has been reported, as has an increased incidence of extrahepatic malignancy in primary biliary cirrhosis (PBC). Monoclonal immunoglobulin elevations in PBC are rare, and there have been only three cases in the literature of PBC associated with multiple myeloma. We describe a patient who was concurrently diagnosed as having PBC and multiple myeloma, and emphasize the need to consider myeloma when evaluating monoclonal gammopathy in PBC. We also discuss the possible mechanisms for the association of the two conditions.

Aged↗
PubMed1993

Clinical application of angioscopy during carotid endarterectomy for patients with internal carotid artery stenosis.

The accuracy of angioscopy in detecting atherosclerotic changes, such as plaque, ulcer, and mural thrombus, in the extracranial cerebral arteries was evaluated during carotid endarterectomy by comparison with angiographic and operative findings. Ten patients with internal carotid artery stenosis underwent intraoperative angioscopy during surgery. After clamping the carotid bifurcation, intra-arterial atherosclerotic lesions were observed with an angioscope (0.8 or 1.4 mm outer diameter) inserted through a small incision in the common carotid artery. Angioscopic findings correlated well with both angiographic and operative findings in six patients, and provided additional information in two patients, such as organized thrombi within the ulcer and mural thrombi. Angioscopic findings were quite different to those from angiograms in two patients. In one, an ulcer on angiograms was false positive, and in the other, false negative. These findings were confirmed intraoperatively. Our results suggest that preoperative carotid angioscopy is of great value in detecting ulcers more accurately than angiography, and in selecting candidates for carotid endarterectomy, although further development of equipment is needed.

Adult↗
PubMed1993

Paroxysmal nocturnal hemoglobinuria with myelofibrosis: progression to acute myeloblastic leukemia.

A 58-year-old male was diagnosed as having paroxysmal nocturnal hemoglobinuria (PNH) with myelofibrosis in 1984. The administration of hydroxyurea and low dose splenic irradiation were initiated for abdominal distention due to splenomegaly in 1987. In May 1990 the patient developed smouldering acute myeloblastic leukemia (AML); and the blasts proliferated in response to G-CSF administered for refractory pneumonia. The patient died of pneumonia and pleural involvement of leukemia in September 1990. FACS analysis of the blasts using anti-decay accelerating factor (DAF) (CD55) and CD59 (membrane attack complex inhibition factor: MACIF) monoclonal antibodies demonstrated that 25.5% and/or 87.3% of the blasts were negative for DAF or CD59 respectively. There is the earlier evidence that about 90% leukemic myeloblasts from non-PNH AML patients are positive for DAF, and nearly 100% of non-PNH neutrophils have been shown to be positive for both DAF and CD59. Our data suggest that the leukemic blasts from this patient may have derived from the PNH clone.

Antigens, CD↗
PubMed1993

Levels of serum granulocyte colony-stimulating factor in patients with chronic myeloid leukemia.

To clarify the patho-physiologic role of granulocyte colony-stimulating factor (G-CSF) in chronic myeloid leukemia (CML), we determined the serum levels of G-CSF in various stages of CML using a very sensitive method: chemiluminescence enzyme immunoassay (CLEIA). This method makes it possible to estimate very low levels of serum G-CSF. In the present study, serum samples from 25 patients in chronic phase and 16 in blastic crisis, as well as samples from 33 healthy volunteers were investigated. The serum G-CSF levels in chronic phase of CML (2.95 +/- 3.91 pg/ml) were significantly lower than those in normal controls (15.92 +/- 6.53 pg/ml) and in blastic crisis of CML (15.52 +/- 17.65 pg/ml) within a range of very low levels (p < 0.001, p < 0.02). Moreover, a reverse correlation between blood neutrophil counts and serum G-CSF levels were clearly demonstrated for CML including blastic crisis (r = 0.405, p < 0.02). Interestingly, a sequential parallel relation was observed between serum G-CSF levels and neutrophil alkaline phosphatase (NAP) scores for a patient with CML in chronic phase. Our observations indicate that a negative feedback mechanism exists between peripheral neutrophils and serum G-CSF levels in the chronic phase of CML, and that very low levels of G-CSF in chronic phase of CML might be an important cause for the low NAP scores.

Alkaline Phosphatase↗
PubMed1993

Correlation dimension of heart rate variability: a new index of human autonomic function.

Correlation dimension analysis (CDA) of spontaneous heart rate variability in humans was performed with the use of autonomic blocking agents (propranolol and atropine) and postural change, and was compared with heart rate power spectral analysis (HRPSA). The correlation dimension was increased by the suppression of sympathetic activity and decreased by the suppression of parasympathetic activity. Atropine abolished the correlation dimension and the low- and high-frequency components of HRPSA. With a postural change from supine to standing, the low- to high-frequency power ratio was significantly increased, indicating the augmentation of sympathetic activity or the reduction of parasympathetic activity, or both. Thus, it was suggested that a postural change from supine to standing causes the predominance of sympathetic activity. As this postural change decreased the correlation dimension, it was also indicated that the predominance of sympathetic activity may decrease the correlation dimension. CDA was superior to HRPSA in that the former method provided a measure of the effect of propranolol on the heart in the supine position, which could not be evaluated by the latter method. Thus, CDA of heart rate variability is a useful non-invasive tool for evaluating the autonomic balance.

Adult↗