Biomedical subjects

M Kudo

Publications and source records attributed to M Kudo.

At least 289 records · Page 16Linked to original sources

PubMed1991

Hepatic focal nodular hyperplasia: specific findings at dynamic contrast-enhanced US with carbon dioxide microbubbles.

Dynamic contrast material-enhanced ultrasonography (US) with intraarterial infusion of carbon dioxide microbubbles was performed for four cases of histologically proved focal nodular hyperplasia (FNH) in four patients and for 167 cases of various hepatic nodules in 144 patients. No complications due to dynamic US were observed in any of the 148 patients. All FNH nodules were less than 3 cm in diameter. Consistent specific findings of FNH were not obtained with US, computed tomography, magnetic resonance imaging, radiocolloid scanning, or angiography in the four cases of FNH. In contrast, the characteristic vascular pattern (ie, early central hypervascular supply with centrifugal filling to the periphery at the arterial phase and a uniform or lobulated dense stain at the capillary phase) was observed in all four cases of FNH with dynamic US. This vascular pattern demonstrated in FNH with dynamic US was not seen in any of the 167 hepatic nodules, including 44 small hepatocellular carcinomas less than 3 cm in diameter. Therefore, the newly developed, dynamic contrast-enhanced US technique seems to be extremely sensitive and specific for diagnosing FNH and is useful in the differentiation of FNH from other hepatic tumors, especially hepatocellular carcinoma.

Adult↗

PubMed1991

Suprachiasmatic nucleus and retinohypothalamic projections in moles.

The suprachiasmatic nucleus of the hypothalamus (SCN) and the retinohypothalamic projections were identified in one species of old-world moles, all of whom are blind as a result of natural loss of vision. A cyto-architectonic study revealed that the SCN is well developed, even though other visual nuclei in the dorsal thalamus and the midbrain are not. An immunohistochemical study showed that vasoactive intestinal polypeptide (VIP)-like immunoreactive cell bodies and fibers were distributed in the SCN, as has been reported in other mammals. Following intraocular injections of wheatgerm agglutinin conjugated to horseradish peroxidase (WGA-HRP), the central retinal projections were examined. The results indicated that the SCN receives a direct projection from the retina, as seen in many other mammals. In addition to the projection to the SCN, retinal fibers were seen to terminate in the anterior hypothalamic region and the retrochiasmatic area, as observed in some other mammals. In moles, retinohypothalamic projections are bilateral, with an ipsilateral predominance. Considering that the retinogeniculate and retinotectal projections are vestigial, it is highly probable that the optic pathway in moles primarily consists of retinohypothalamic projections, which are devoted to the entrainment of circadian and circannual rhythms.

Animals↗

PubMed1991

In vivo and in vitro studies in a patient with cyclical Cushing's disease showing some responsiveness to bromocriptine.

In vivo and in vitro studies were carried out in a 37-year old female with cyclical Cushing's disease. Preoperative studies revealed periodic secretions of urinary corticosteroids occurring with a cyclicity of 2-3 weeks. On transsphenoidal surgery, a microadenoma was visualized in the anteroinferior portion of the anterior pituitary. Gel filtration analyses of the adenoma and surrounding tissues revealed increased concentrations of beta-endorphin and an activated conversion of beta-lipotropin to beta-endorphin in the adenoma compared with the surrounding tissues. These findings were in agreement with the characteristics previously reported for corticotroph adenomas. However, unexpectedly, concentrations of ACTH and beta-lipotropin in the adenoma were only slightly higher than those in the surrounding tissues. Precise mechanisms underlying this unusual finding were elusive, but it may have been due to the periodic nature of her hypercortisolism. In addition, this patient was reproducibly responsive to bromocriptine (2.5 mg, per os) with a reduction of the plasma cortisol level. Although this may suggest an intermediate lobe subtype of Cushing's disease as proposed by Lamberts' group, our case did not have any other characteristic suggestive of this proposed variant. However, it is tempting to speculate that cyclical changes in the central dopaminergic tone may have been at least a partial trigger for the periodic hormonogenesis in this patient.

Adrenocorticotropic Hormone↗

PubMed1991

[Pharmacological action of SN-408, a novel long-acting selective beta 2-adrenoceptor agonist].

The bronchodilating effect and other related pharmacological properties of SN-408 were studied in comparison with those of isoproterenol, salbutamol and procaterol. SN-408 caused concentration-dependent relaxation of isolated guinea pig trachea via the beta 2-adrenoceptor. The order of relaxation potency was: procaterol greater than SN-408 greater than or equal to isoproterenol greater than salbutamol, but the duration of the action of SN-408 was far longer than those of other beta-agonists. Positive chronotropic and inotropic actions of SN-408 in isolated guinea pig right atria and left atria were less potent than those of other beta-agonists. In isolated guinea pig lung tissues, SN-408 increased cyclic AMP contents. Also in vivo, SN-408 showed dose-dependent bronchodilating action by i.v. administration in anesthetized guinea pigs and by inhalation in conscious guinea pigs. Bronchodilating actions of SN-408 were less potent than those of procaterol and isoproterenol, but the duration of action of SN-408 was far longer than those of other beta-agonists. SN-408 showed no evidence of the development of tolerance to the bronchodilating action. SN-408 caused small tachycardia in guinea pigs by i.v. and inhalation. SN-408 given i.v. suppressed vascular permeability in mice. These results indicate that SN-408 is a long-acting and selective beta 2-stimulant bronchodilator.

Adrenergic beta-Agonists↗

PubMed1991

Endothelin-1-induced phosphorylation of the 20-kDa myosin light chain and caldesmon in porcine coronary artery smooth muscle.

Endothelin-1 (ET), a potent vasoconstrictor, induces a sustained increase in the phosphorylation level of the 20-kDa myosin light chain (MLC) in porcine coronary artery strips. ET also induces late phosphorylation of caldesmon, which is mimicked by 12-deoxyphorbol 13-isobutyrate, but not by 60 mM KCl. Nitroglycerin, a vasorelaxant, completely reverses the ET-induced phosphorylation of MLC, but not that of caldesmon. These results suggest an important regulatory role of MLC phosphorylation in ET-induced contraction.

Animals↗

PubMed1991

Localization of kallikrein in rat pineal glands.

The presence of kallikrein mRNA has been reported in the pineal gland of rats. Using an antibody to rat tissue kallikrein, we immunohistochemically examined the localization of cell components producing tissue kallikrein in this gland. The kallikrein immunoreactive cells were scattered in the parenchyma of the pineal gland. Their cell bodies were polymorphic with cell processes and a large nucleus similar to that of the pinealocyte. Frequently immunoreactive materials were seen to be localized in the perivascular areas.

Animals↗

PubMed1991

Pharmacokinetic study of selective continuous internal carotid CDDP infusion in malignant brain tumors.

Cis-diamminedichloroplatinum (CDDP) was administered by selective continuous internal carotid infusion to nine patients with malignant brain tumors, including five glioblastomas, one mixed glioma, and three metastatic tumors. CDDP was infused through a catheter in the internal carotid artery at 100 mg/hr in all cases, except one glioblastoma case in which the lower rate of 10 mg/hr was used. The results of CDDP concentration measurements were: 1) CDDP in the blood peaked at termination of CDDP infusion and then decreased slowly, 2) CDDP infiltrated intratumoral cysts and accumulated there, 3) CDDP in the cerebrospinal fluid peaked 6-18 hours after infusion, and 4) the tumor/plasma CDDP ratio varied from 2 to 8. The size of tumors decreased moderately in three of the nine cases, but no complete response was achieved. The histological changes due to CDDP were observed in the tumor tissue and were absent in the normal brain parenchyma.

Adult↗

PubMed1991

[Ewing's sarcoma in the retroperitoneum].

The patient was a female aged 18. Hematuria was discovered at an examination two years previously at which time the patient was complaining of right lumbar pain. The patient visited our hospital with a chief complaint of right abdominal tumor in June, 1988. A retroperitoneal tumor, 77 X 45 mm in size, was observed by CT and ultrasonic examination, and the right kidney was in hydronephrosis. An operation was performed in September, 1988, based on a diagnosis of retroperitoneal tumor and hydronephrosis. The tumor was seen to have involved the right ureter. Subsequently the tumor was surgically removed; right total nephroureterectomy and partial cystectomy were performed at that time. The removed tumor was 90 X 70 mm in size and 120 g in weight; it was histopathologically diagnosed as extraskeletal Ewing sarcoma. A systemic examination was carried out postoperatively, but no abnormalities were observed. As of September, 1990, the patient had had no recurrence and was being kept observation on an outpatient basis. There have been a total of 210 case reports regarding extraskeletal Ewing sarcoma published worldwide, including our case and 26 cases in Japan, so far as we know. However those of a lesion of retroperitoneal origin are extremely rare, numbering only 11 cases worldwide and 2 Japan. Herein we report our case of extraskeletal Ewing sarcoma with reference to the other 209 cases reported in the literature to date.

Adolescent↗

PubMed1991

[The effect of enflurane anesthesia on plasma superoxide dismutase (SOD)-like activity in elderly patients].

Plasma SOD-like activity during enflurane anesthesia was measured according to electron spin resonance in ten elderly patients over 66 years and in nine patients under 64 years. Anesthesia was induced with thiopental 4 mg.kg-1 and succinyl-choline 0.8-1.0 mg.kg-1 intravenously and was maintained with enflurane 1.0-2.0% in nitrous oxide and oxygen. They were ventilated manually throughout the surgery. The mean plasma SOD-like activity before anesthesia was lower in the elderly group compared with the control group. This decreased significantly in the elderly patients on the first and third day after surgery. There was no relationship between plasma SOD like activity and patient age. We conclude that increased superoxide anion production in the post-operative period may affect plasma SOD-like activity.

Aged↗

PubMed1991

[Pituitary-adrenal response to ketamine].

Fahringer and coworkers have shown the possibility that the steroid response to ketamine is not caused by a direct action on the adrenal gland and is dependent on the presence of a functioning pituitary gland. To clarify these points, we examined the effects of ketamine on ACTH production in isolated pituitary cells of rats. Corticosterone and aldosterone production was measured in isolated adrenal cells of rats to test the possibility of a direct influence of ketamine on the adrenal gland. Rat anterior pituitary and adrenal glands cells respectively were obtained by enzymatic digestion of intact glands collected from Wistar rats. This cell pellet was suspended in Hank's buffer containing 0.1% BSA and distributed to plastic tubes. The cell samples were preincubated for 90 min in a 37 degrees C waterbath under an atmosphere of 5% CO2/95% O2. Ketamine was then added to normal and to ACTH treated cells, which were incubated for 4 hr, and centrifuged. Samples of the supernatant liquid were taken, and aldosterone and ACTH were measured by radioimmunoassay. Corticosterone was determined by a fluorimetric method. Ten individual measurements were made for each sample. Results are expressed as mean +/- s.e. Statistical analysis was performed using Student's t-test. The results indicated that ketamine significantly increased ACTH secretion in the isolated pituitary cells. On the other hand, ketamine had no significant effects on adrenal corticosterone formation. There were similar effects by ketamine on ACTH-induced corticosterone production when compared with that obtained by ACTH alone.(ABSTRACT TRUNCATED AT 250 WORDS)

Adrenal Glands↗

PubMed1991

[Tumor hemodynamics in hepatic nodules associated with liver cirrhosis: relationship between cancer progression and tumor hemodynamic change].

Tumor hemodynamics including arterial vascularity (AV) and portal perfusion (PP) were evaluated in histologically confirmed 55 hepatic nodules associated with cirrhosis using ultrasonographic (US) angiography during intraarterial carbon dioxide microbubbles injection and CT during arterial portography. Tumor hemodynamic patterns were classified into 6 types as follows: Type I (n = 10): PP (+), AV (hypo); Type I' (n = 2): PP (+), AV (iso); Type II (n = 5): PP (-), AV (hypo); Type III (n = 8): PP (-), AV (iso); Type IV (n = 25): PP (-), AV (hyper), Type V (n = 5): PP (partially +), AV (vascular spot in hypovascular). Eight nodules of Type I were diagnosed as benign nodules histologically including adenomatous hyperplasia (AH) (n = 6) and regenerative nodule (n = 2). Hundred percent (5/5) of Type II and 88% (7/8) of Type III nodules were well-differentiated HCC, in contrast to 8% (2/25) of Type IV nodules, typical HCCs. Fatty metamorphosis was observed in 75% (6/8) of Type III nodules, in contrast to 16% (4/25) of typical (classical) HCC nodules (Type IV). We concluded that at the malignant transformation from AH to HCC, reduction of portal blood flow in the nodule precedes the initiation of the increase of the arterial tumor vessel. Moreover, early stage HCC could exhibit hypovascular (Type I, II), isovascular (Type III), or vascular spot in hypovascular pattern (Type V) compared with a typical HCC (Type IV). It was also suggested that the more mature as a neoplasms the HCC becomes, the more the arterial tumor vessel in the nodule increases and fatty metamorphosis of well-differentiated HCC is highly related with tumor hemodynamic condition, i.e., hypoperfusion state from both arterial and portal vessel.

Carcinoma, Hepatocellular↗

PubMed1991

The endocrine response after burns.

To identify the dynamic response of hormones after burns with special reference to ANP during shock and the subsequent period, plasma concentrations of atrial natriuretic peptide (ANP), aldosterone, cortisol, arginine vasopressin (AVP), corticotropin, (ACTH), plasma renin activities (PRA), norepinephrine (NE) and epinephrine (E) were measured from the day of ICU admission and for 7 days following burn injury. Plasma AVP levels were highest on ICU admission and correlated with size of the burn injury ranged from 20-60 percent of the total body surface area. Between the 5th and 6th postburn day plasma ANP levels elevated while plasma AVP levels returned to normal. Urine sodium concentrations decreased from the 3rd day. Plasma aldosterone levels declined after the 2nd day. Mean epinephrine (E) and norepinephrine (NE) levels elevated on admission and remained elevated throughout the study. These results suggest that ANP plays important role for restoring fluid homeostasis by improving edema in burned tissues during refilling periods in burns.

Adrenocorticotropic Hormone↗

PubMed1991

[Role of prostaglandin E1 in steroidogenesis by isolated rat adrenal cells].

In order to investigate the effects of prostaglandin E1 (PGE1) used in hypotensive anesthesia on the adrenal endocrine function, aldosterone, corticosterone (Comp B) and cAMP production were measured in isolated glomerulosa (G-c) and fasciculata cells (F-c) of the rats. Rat glomerulosa and fasciculata cells were obtained by enzymatic digestion of the adrenals of male wistar rats. The cell pellet was suspended in Hank's balanced salt solution containing 0.1% BSA and distributed in 900 microliters aliquots to polyethylene tubes. The samples were preincubated for 90 min in a 37 degrees C water bath aerated with 5% CO2/95% O2. PGE1 or ACTH 50 microliters was added and incubated for 4 hr. Total volume of the incubation medium is 1.0 ml. Aldosterone and cAMP were measured by radioimmunoassay and Comp B was determined by fluorimetric method. PGE1 increased significantly the basal secretion of aldosterone and Comp B in G-c and F-c, respectively. The steroidogenic effect of PGE1 was dose dependent in aldosterone production. This aldosterone production was also accompanied with cAMP production. On the other hand, significant increase of cAMP was not observed in comp B production. These results suggest that cAMP may be the second messenger in PGE1-induced aldosterone production in G-c. But PGE1 receptors in F-c seem not to be coupled to the adenylate cyclase system. The addition of ACTH and PGE1 resulted in inhibition of aldosterone secretion when compared with that obtained by ACTH alone. Several researchers have shown that low doses of PGE1 depressed the basal aldosterone secretion. These findings may be contributing to Na-uresis effect during PGE1-induced hypotension.

Adrenal Cortex↗

PubMed1991

[Demonstration of PIVKA-II and AFP production by gastric cancer by indirect immunoenzymatic staining of paraffin sections].

The patient had elevated plasma PIVKA-II and serum AFP levels. However, no tumor was detected with an ultrasonography, angiography, abdominal computed tomography (CT), and magnetic resonance imaging (MR). Gastric endoscopic examination disclosed gastric cancer and then subtotal gastrectomy was done. Shortly after the surgery, both plasma PIVKA-II and serum AFP levels returned to each normal level. The extirpated tumor revealed histologically immature and mature cancer cells. It was pathologically diagnosed as IIc early cancer. The localization of PIVKA-II and AFP in gastric cancer cells was demonstrated by the immunostaining method using monoclonal antibody. Taken together, these results indicate that cancer cells may produce PIVKA-II or AFP in this patient.

Biomarkers↗

PubMed1991

[Plasma alpha-human atrial natriuretic polypeptide levels during surgery for pheochromocytoma].

We measured plasma alpha-human atrial natriuretic polypeptide (alpha-hANP) and catecholamine concentrations during anesthesia and surgery for pheochromocytoma in five patients ranging in ages from 19 to 69. Plasma catecholamine concentrations and systemic blood pressure increased extremely during surgical manipulation of the tumor, while plasma alpha-hANP levels did not change even during surgical manipulation or after removal of the tumor as compared with preanesthetic values. Our findings suggest that plasma alpha-hANP levels were unchanged during anesthesia and surgery for human pheochromocytoma.

Adrenal Gland Neoplasms↗

PubMed1991

[In vivo measurement of hepatic binding protein in chronic liver disease--validation as a measure of hepatic functional reserve].

[Tc-99m] Galactosyl-neoglycoalbumin (TcNGA) is a synthetic radiolabeled ligand specific to the hepatocyte receptor, hepatic binding protein (HBP), a specific receptor to serum asialoglycoprotein. A TcNGA study was performed on 34 humans: normal volunteers (7) chronic hepatitis (6), hepatic cirrhosis (8), and hepatocellular carcinoma superimposed on cirrhosis (13). Heart and liver time activity curves were obtained following intravenous injection of TcNGA (5 mCi, 1.82 x 10(-9) mol/kg). HBP concentration ([HBP]) was calculated by curve-fitting techniques using the nonlinear three compartment model, which includes biomolecular reaction between HBP and TcNGA. [HBP] values were compared with conventional liver function tests. [HBP] had a good correlation with prothrombin time (n = 34, r = 0.694, p = 0.0001) thrombotest (n = 34, r = 0.692, p = 0.0001), hepaplastin test (n = 26, r = 0.787, p = 0.0001), albumin (n = 34, r = 0.712, p = 0.0001), cholinesterase (n = 34, r = 0.801, p = 0.0001), ICGR15 (n = 33, r = 0.761, p = 0.0001), KICG (n = 30, r = 0.709, p = 0.0001), ICG Rmax (n = 12, r = 0.735, p = 0.0064) and Child-Turcotte classification score (n = 34, r = 0.819, p = 0.0001). We concluded that excellent correlations of [HBP] to conventional liver function tests suggest that in vivo receptor measurement via TcNGA kinetic analysis is a sensitive and promising method in the estimation of hepatic functional reserve in patients with chronic liver disease.

Adult↗

PubMed1991

[Clinical study on total intravenous anesthesia with droperidol, fentanyl and ketamine--3. Pharmacokinetics during prolonged continuous ketamine infusion].

A simple and precise method has been developed for the analysis of plasma ketamine and its metabolites using gas chromatography with flame ionization detection after elution by trifluoroacetic dehydride. Seven surgical patients who received total intravenous anesthesia with droperidol, fentanyl and ketamine anesthesia over 5 hours were the subjects of the study. During the anesthesia, ketamine levels were from 1.0 to 2.0 micrograms.ml-1. After the termination of ketamine infusion, their levels decreased gradually. Metabolites I levels were elevated gradually to about twofold of that of ketamine and remained high. Metabolite II was detected in only two patients and their levels were under 0.2 micrograms.ml-1. The results of our study suggest that this type of anesthesia of prolonged duration is safe as judged by the present pharmacokinetic study.

Adult↗

PubMed1991

Validation of in vivo receptor measurements via in vitro radioassay: technetium-99m-galactosyl-neoglycoalbumin as prototype model.

Hepatic binding protein (HBP) is a hepatocyte-specific receptor for serum asialoglycoproteins. The receptor also recognizes a synthetic glycoprotein that has been developed as a radiopharmaceutical, technetium-99m-galactosyl-neoglycoalbumin (99mTc-NGA). This report describes the correlation between receptor parameters measured in vivo via kinetic modeling of 99mTc-NGA and those measured by in vitro radioassay of biopsied liver tissue. Eleven patients with diffuse hepatic disease underwent percutaneous liver biopsy followed by a 99mTc-NGA functional imaging study. In vivo measurements of HBP quantity Ro and forward binding rate constant kb obtained from the kinetic analysis of 99mTc-NGA liver and blood time-activity data were compared to total receptor quantity and the HBP-99mTc-NGA association constant KA as measured by Scatchard binding assay of the biopsied tissue. The correlation coefficients between in vivo and in vitro measurements were 0.73 (df = 8, p = 0.015) and 0.98 (df = 8, p less than 0.01) for Ro and kb, respectively. The in vivo measurements of HBP biochemistry via kinetic analysis of the radiopharmaceutical time-activity data reflect the average concentration and affinity of the receptor. This study further substantiates the validity of 99mTc-NGA as a quantitative probe for the HBP receptor.

Adult↗