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Biomedical subjects

M Kudo

Publications and source records attributed to M Kudo.

At least 253 records · Page 14Linked to original sources
PubMed1993

The sites and expansion of intra-embryonic blood islands in the early chick embryo.

The intraembryonic blood islands preceding the hepatic haemopoiesis, were examined in embryos from stage 17 to 19 by light microscopy, and their three-dimentional expansion was demonstrated. These blood islands were located in the mesenchyme of the lateral fold, mesentery, allantois and ventral aorta, commonly showing large scale. Except the lateral fold, however, those were just temporary sites. Particularly large islands were necessarily found in the mesenchyme of the lateral fold at the stages examined. They were present bilaterally and exhibited cephalocaudally long, rod-like structures with variable sizes. The largest island measured over 2,600 microns in length.

Animals↗
PubMed1993

[Dietary habits and serum fatty acid compositions of women college students--changes in serum lipids and fatty acids by dietary education].

To obtain fundamental information for prevention of coronary heart disease in young adults, frequency of dietary intake, blood lipid and serum fatty acid compositions were examined for 114 female students. The relationship of selected food intake to serum fatty acid composition was also examined. Results of a nutritional survey were used to identify students who had a frequency of fish intake of "none" or "1-2 times/week" from whom random selection into two groups was accomplished: control group (n = 31) and education group (n = 31). The education group received a recommendation for increasing fish intake for 3 months. The effect of the education program was evaluated by examination of blood lipids, serum fatty acid compositions and frequency of dietary intake. Fifty-four percent of the students reported "none" or "1-2 times/week" for the frequency of fish intake, and 76% of them reported "1 and more times/day" for oil intake. The proportion of serum saturated fatty acids, monounsaturated fatty acids, polyunsaturated fatty acids were 28.9%, 24.4%, 46.8%, respectively. Of the polyunsaturated fraction, 41.4% was omega 6-polyunsaturated fatty acids, and that of omega 3-polyunsaturated fatty acids was 5.4%. The omega 3/omega 6 ratio was 0.13. Serum omega 3-polyunsaturated fatty acids was directly related to frequency of fish intake, and serum omega 6-polyunsaturated fatty acid, especially linoleic acid, was directly related to frequency of oil intake. After a 3-month education program, the frequency of fish intake and meat intake increased, while frequency of oil intake decreased in the education group. Serum omega 3-polyunsaturated fatty acid (in particular eicosapentaenoic acid, docosahexaenoic acid) increased in the education group, but not in the control group. The omega 3/omega 6 ratio increased from 0.13 to 0.18 in the education group. These results indicate that dietary education for fish intake is effective in increasing serum omega 3-polyunsaturated fatty acids, and the omega 3/omega 6 ratio for female students with initial low intake of fish and a high intake of omega 6-polyunsaturated fatty acids.

Adult↗
PubMed1993

[Effects of sevoflurane anesthesia on serotonin metabolism in rat brain].

To elucidate the mechanism of general anesthesia, effects of sevoflurane anesthesia on serotonin metabolism in rat brain were studied. Three percent sevoflurane was administered for twenty minutes to Wistar male rats weighing 230-270g under spontaneous respiration. The rats were sacrificed by decapitation and the brains were rapidly removed. They were dissected into nine discrete regions, locus coeruleus, pons plus medulla oblongata, hypothalamus, thalamus, basal ganglia, midbrain, hippocampus, amygdala and cerebral cortex. The contents of serotonin (5-HT) and one of its major metabolites, 5-hydroxyindole-3-acetic acid (5-HIAA) were measured by high performance liquid chromatography with the dual-cell coulometric detector before anesthesia, 20 minutes after the start of anesthesia and at the recovery from anesthesia. Significant increases in 5-HT levels were observed in the pons, hypothalamus, midbrain, amygdala and cerebral cortex by sevoflurane anesthesia as compared with the control group. 5-HIAA levels decreased significantly in the thalamus by sevoflurane anesthesia, while an appreciable increase in 5-HIAA levels was observed in the basal ganglia at the recovery from anesthesia. It is concluded that 5-HT metabolism is significantly suppressed in the pons, hypothalamus, thalamus, midbrain, amygdala and cerebral cortex during sevoflurane anesthesia and this change in 5-HT metabolism may be associated with a mechanism of sevoflurane anesthesia.

Anesthesia, Inhalation↗
PubMed1993

[Effects of ketamine on pituitary-adrenal axis in rats].

We examined the effects of ketamine (20 mg.kg-1) on plasma ACTH, Comp. B, aldosterone and ir-ANP levels in unstrained rats. We divided rats into two groups, saline group as control (saline group) and ketamine group (ketamine treated rats). Plasma samples were taken before ketamine or saline infusion to determine a pre-treatment value, and samples were also taken at 15, 30, 60 minutes after the infusion. ACTH, aldosterone and ir-ANP were measured by radioimmunoassay. Comp. B was determined by a fluorometric method. We obtained the following results: 1) Plasma ACTH levels increased significantly in the ketamine group, while there was no such a marked increase in the saline group. The slight increase in ACTH in the saline group could have resulted from handling during i.v. infusion or psychic stress; 2) Plasma corticosterone and aldosterone levels increased markedly in both groups. However, the magnitude of the adrenocortical response was significantly greater than in the saline group; 3) Plasma ir-ANP showed no significant change in both groups. These results suggest that ketamine stimulated pituitary-adrenal axis, and the adrenal stimulation produced by ketamine are greater than those induced by the stress of handling or psychic stress.

Adrenocorticotropic Hormone↗
PubMed1993

Progressive splenomegaly with increasing extramedullary haematopoiesis in subcutaneous 9L-glioma bearing rats.

We have succeeded in inducing progressive splenomegaly by inoculating 9L-glioma cells into the back subcutaneous regions of Fischer rats. The progressive splenomegaly was histologically characterized by progressively increased extramedullary haematopoiesis. Immunohistochemically Leu 7 positive cells were present in the enlarged spleen, suggesting that the spleen possessed natural killer (NK) cells. However, the splenic NK cell activity obtained in a 4h-51Cr release assay at 5 weeks after inoculation was below 5%, suggesting that the cytotoxic function of the NK cells was depressed. Bone marrow morphologically appeared not to be suppressed. Although the exact cause and mechanism of the progressive splenomegaly with prominent extramedullary haematopoiesis and severe suppression of the splenic NK cell activity remains speculative at present, it could be a unique manifestation of a systemic host-reaction reflected by the 9L-glioma continuously growing in the subcutaneous regions. This experiment could be a useful approach to the study of splenic and other reticuloendothelial roles in host-immunity in the tumour bearing state.

Animals↗
PubMed1993

Intrahepatic portosystemic venous shunt: diagnosis by color Doppler imaging.

Intrahepatic portosystemic venous shunt is a rare clinical entity; only 33 such cases have been reported. It may be congenital, or secondary to portal hypertension. Five patients with this disorder are presented, each of whom was diagnosed by color Doppler imaging, including waveform spectral analysis. One patient with clinical evidence of cirrhosis and portal hypertension had episodes of hepatic encephalopathy and elevated blood levels of ammonia. This patient had a large tubular shunt between the posterior branch of the portal vein and the inferior vena cava. Shunts of this type are considered to be collateral pathways which develop in the hepatic parenchyma as a result of portal hypertension. The other four patients had no evidence of liver disease, and all four evidenced an aneurysmal portohepatic venous shunt within the liver parenchyma. Shunts of this type are considered congenital. The diagnosis of intrahepatic portosystemic venous shunts was established by color Doppler imaging, which demonstrated a direct communication of color flow signals between the portal vein and hepatic vein, in addition to the characterization of the Doppler spectrum at each sampling point from a continuous waveform signal (portal vein) to a turbulent signal (aneurysmal cavity), and finally, to a biphasic waveform signal (hepatic vein). As demonstrated by the five patients, color Doppler imaging is useful in the diagnosis of an intrahepatic portosystemic hepatic venous shunt, and the measurement of shunt ratio may be useful in the follow-up and determining the therapeutic option.

Adult↗
PubMed1993

Quantitative assessment of hepatocellular function through in vivo radioreceptor imaging with technetium 99m galactosyl human serum albumin.

Technetium 99m diethylenetriaminepentaacetic acid-galactosyl human serum albumin is a newly developed analog ligand to asialoglycoprotein receptor, which is a hepatic cell surface receptor specific for galactose-terminated glycoproteins. Hepatic functional imaging, which yields estimates of asialoglycoprotein receptor concentration, was performed after intravenous injection of 3 mg technetium 99m diethylenetriaminepentaacetic acid-galactosyl human serum albumin. A total of 75 human subjects were studied: 6 controls without liver diseases, 51 patients with chronic liver diseases and 18 patients with acute liver diseases. In chronic liver disease the asialoglycoprotein receptor concentration significantly correlated with the clinical severity based on the criteria of the Liver Cancer Study Group of Japan (rs = -0.890, p = 0.0001). Good correlations between the asialoglycoprotein receptor concentration and conventional liver function tests were also observed. In acute liver disease the asialoglycoprotein receptor concentration correlated well with the normotest (r = 0.796, p = 0.0001), prothrombin time (r = 0.701, p = 0.0002) and total serum bilirubin (r = -0.642, p = 0.0007). We conclude that the parameter, asialoglycoprotein receptor concentration, obtained from the kinetic analysis of technetium 99m diethylenetriaminepentaacetic acid-galactosyl human serum albumin time-activity data, is a sensitive measure of functioning hepatocyte mass in acute and chronic liver disease.

Acute Disease↗
PubMed1992

Determination of ofloxacin in human serum by high-performance liquid chromatography with column switching.

The chromatographic behaviour of ofloxacin on various sorbents, including ODS, C8, C1, nitril, phenyl and tert,-butyl, as stationary phases was investigated and a high-performance liquid chromatography (HPLC) assay was developed for the determination of ofloxacin in serum. The serum samples were directly introduced onto an HPLC column after filtering through a Morcut II membrane filter to remove proteins. The filtrate was concentrated on a pre-column using a phenyl stationary phase and was then introduced to an analytical column with an ODS stationary phase by column switching. Ofloxacin and enoxacin as an internal standard were detected by ultraviolet absorbance at 300 nm. Determination was possible for ofloxacin over the concentration range 50-2000 ng/ml; the limit of detection was 20 ng/ml. The recovery of ofloxacin added to serum was 88.8-101.7% with a coefficient of variation of less than 5.2%. This method is applicable to pharmacokinetic studies of patients after treatment with ofloxacin.

Chromatography, High Pressure Liquid↗
PubMed1992

Kallikrein-producing cells in the rat pituitary and pineal gland.

By using an immunohistochemical technique, kallikrein-producing cells in the anterior pituitary of rats were identified to be the same as prolactin-producing cells. Kallikrein was localized at the Golgi apparatus, the rough endoplasmic reticulum and secretory granules. Kallikrein was also located in the perivascular cells of the pineal gland.

Animals↗
PubMed1992

Acute and subacute inhalation toxicity of silane 1000 ppm in mice.

Male ICR mice were exposed to silane 1000 ppm, a concentration 200 or 2000 times higher than the recommended occupational exposure limits by many countries and academic associations, for 1, 2, 4, and 8 h (phase I study) and for 6 h/day, 5 days/week, over 2 and 4 weeks (phase II study). Hematological and biochemical studies were performed, and the animals were examined for histopathological lesions of the cornea, nasal cavity, respiratory tract, lung, liver, kidney, spleen, pancreas, thymus, thyroid, bone marrow, salivary glands, esophagus, and testis. All mice in both studies survived until they were sacrificed. In the phase I study, no exposure-related changes were found as a result of the hematological, biochemical, or histopathological examinations. In the phase II study, hematological and biochemical examinations failed to reveal any exposure-related changes, but mild irritation, manifested in the form of a small amount of exudate (eight out of ten animals), and inflammatory cells and/or necrotic cells on the nasal mucosa (six out of ten animals) was observed in the mice exposed to silane for 4 weeks. These findings suggest that silane toxicity and irritation are not severe.

Administration, Oral↗
PubMed1992

Coexisting acromegaly and a unilateral cortisol-producing adrenal adenoma: a possible variant of multiple endocrine neoplasia type I.

An unusual case of coexisting acromegaly and Cushing's syndrome is reported in a 34-yr-old female. There was no biochemical or morphological evidence to suggest the presence of other endocrinopathies. She did not have any family history to suggest a hereditary tendency to endocrine disorders. Her acromegaly and Cushing's syndrome were proven to be due to a pituitary somatotroph adenoma and a cortisol-producing adenoma in the right adrenocortex, respectively. Surgical removal of both tumors led to a marked biochemical improvement of the two endocrinopathies. To account for the simultaneous occurrence of the two endocrine tumors, at least two endocrine syndromes may be considered. One of them is Carney's complex. However, Cushing's syndrome in this complex is unexceptionally due to primary pigmented nodular adrenocortical disease, differing from the adrenal pathology of our patient. In addition, a lack in this case of any other characteristic suggestive of this syndrome appears to speak against this possibility. A second possibility is multiple endocrine neoplasia type 1. The absence of a parathyroid or pancreatic islet cell tumor does not strongly support this possibility, but adrenocortical lesions are not rare in this syndrome although they are only rarely functional. However, existence of similar case reports, although very few, in the literature leaves the possibility that she represents another rare variant of sporadic multiple endocrine neoplasia type I syndrome.

Acromegaly↗
PubMed1992

Adsorption of sevoflurane by soda-limes.

Dry soda-lime adsorbs significant quantities of halothane, thus influencing on the speed of the induction of anaesthesia with the agent and also on the recovery from anesthesia. Sevoflurane is a new inhaled anesthetic. Although the chemical degradation of sevoflurane with soda-lime has been studied, no information is available about its adsorption by soda-lime. This issue can not be neglected clinically. Two different soda-limes were placed in saturated vapour of sevoflurane for 17 hours to weight adsorbed sevoflurane. Then soda-limes adsorbing sevoflurane was sealed in a test tube after air-drying for 1) 0 min, 2) 10 min, 3) 30 min and 4) 17 hours. The vapour phase of sevoflurane in the test tube at various temperatures were determined using gas chromatography. Sevoflurane vapour concentrations in the test tubes increased in a temperature-dependent manner. Those in the conventional soda-lime were higher than those in the new soda-lime under any experimental conditions. Sevoflurane was released from soda-limes even after air-drying for 17 hours. These results show that much amount of sevoflurane is adsorbed by soda-limes and is released easily in the air. Thus there is a possibility for our patients to inhale unexpected inhaled anesthetics, if we use our anesthetic machine repeatedly.

Journal Article↗
PubMed1992

Relationship of Helicobacter pylori to serum pepsinogens in an asymptomatic Japanese population.

A seroepidemiologic study of the prevalence of Helicobacter pylori infection in Japan was performed, and the relationship between serum pepsinogen I and II levels (markers of gastritis and gastric atrophy) and H. pylori infection was investigated. Four hundred and eighteen asymptomatic children and adults were studied. The prevalence of anti-H. pylori immunoglobulin G antibody increased with age. For persons born after 1950, the frequency of H. pylori infection increased at approximately 1% per year; for those born before 1950 the prevalence was high (70%-80%) and relatively constant. Serum pepsinogen I and II levels were significantly higher in H. pylori-infected volunteers than in H. pylori-uninfected volunteers [51.6 +/- 3 vs. 42.9 +/- 2 ng/mL (P less than 0.05) for pepsinogen I; 16.0 +/- 1 vs. 7.5 +/- 0.8 ng/mL (P less than 0.001) for pepsinogen II]. The ratio of pepsinogen I to pepsinogen II was significantly lower in H. pylori-infected volunteers (3.5 +/- 0.2) than in uninfected volunteers (6.3 +/- 0.3; P less than 0.001). The apparent decrease in prevalence of H. pylori accompanying the Westernization of Japan may eventually be accompanied by a reduction in the frequency of atrophic gastritis, the precursor lesion of the epidemic form of gastric carcinoma, and ultimately result in a decrease in the incidence of gastric carcinoma in Japan.

Adolescent↗
PubMed1992

Analysis of context of 5'-splice site sequences in mammalian mRNA precursors by subclass method.

The signals that direct the excision of introns from mammalian pre-mRNA are not yet well understood. However, at least three kinds of signals--5'-splice site signals, 3'-splice site signals and branch point signals--play important roles in the excision of introns. In the present paper we treat only the 5'-splice sites. In addition to a consensus sequence for 5'-splice signals, several methods have been proposed, based on a statistical model, and used to analyze relative importance of each nucleotide at each position. In our approach a nucleotide sequence is regarded as a string with symbols of 'A', 'T', 'G' and 'C'; important substrings of 5'-splice site sequences, called pattern sequences, are extracted. A pattern sequence expresses which nucleotide is needed at a limited number of positions around the 5'-splice site. It is observed that a particular pattern sequence matches predominantly 5'-splice site sequences nearest to the 5'-end of a gene and another pattern sequence matches predominantly the second nearest ones. Moreover, it is confirmed that the pattern sequences accurately predict authentic 5'-splice sites for unknown genes and explain some mutation examples.

Algorithms↗
PubMed1992

Small hepatocellular carcinoma: diagnosis with US angiography with intraarterial CO2 microbubbles.

Ultrasonographic (US) angiography enhanced with intraarterial CO2 microbubbles, a contrast material used in US imaging, was performed of 103 histologically proved hepatocellular carcinomas (HCCs) smaller than 3 cm in diameter in 95 patients. The detection rate for hypervascular HCC with US angiography was compared with the rate of detection with conventional angiography, digital subtraction angiography (DSA), and computed tomography (CT) after intraarterial injection of iodized oil. Sensitivity in detection of hypervascular HCCs with US angiography was 86% (89 of 103 HCCs), compared with 63% (44 of 70 HCCs) detected with conventional angiography, 70% (23 of 33 HCCs) with DSA, and 82% (75 of 91 HCCs) with CT with iodized oil. US angiography depicted small hypervascular HCCs, especially those less than 1 cm in diameter, and helped clarify vascularity as isovascular or hypovascular in angiographically undetectable HCCs. Findings at US angiography assisted the choice of a therapeutic strategy for treatment of HCC, such as transarterial therapy, percutaneous ethanol injection therapy, or resection.

Angiography, Digital Subtraction↗
PubMed1992

A novel homoisocarbacyclin analog with potent and long-lasting activity.

A synthesis of a novel and chemically stable homoisocarbacyclin analog, TY-11223 (3), has been accomplished. The analog (3), given intravenously or orally, showed potent and long-lasting activities in inhibiting platelet aggregation and, in addition, a good selectivity in biological activities.

Animals↗
PubMed1992

Sonography with intraarterial infusion of carbon dioxide microbubbles (sonographic angiography): value in differential diagnosis of hepatic tumors.

Differential diagnosis of small liver tumors is important, but is not always possible, even with angiography. To solve this problem, we introduced sonographic angiography, which combines sonography and angiography. The vascular pattern of a variety of hepatic nodules was evaluated with sonographic angiography, and the results were compared with those of conventional angiography. Sonographic angiography (sonography performed during intraarterial infusion of carbon dioxide microbubbles) was performed in 184 patients with a total of 222 hepatic nodules: 139 hepatocellular carcinomas, nine adenomatous hyperplasias, seven regenerative nodules, 21 hemangiomas, 33 metastases, seven lymphomas, one granuloma, and five focal nodular hyperplasias. Sonographic angiography detected a hypervascular pattern with peripheral blood supply in cases of hepatocellular carcinoma (sensitivity, 90%; specificity, 89%). Typical vascular patterns of adenomatous hyperplasia, hemangioma, metastasis, and focal nodular hyperplasia on sonographic angiography were hypovascularity (sensitivity, 100%; specificity, 91%), spotty pooling (sensitivity, 100%; specificity, 100%), peripheral hypervascularity (sensitivity, 64%; specificity, 100%), respectively. The detectability of hypervascularity was greater with sonographic angiography than with conventional angiography in hepatocellular carcinoma, metastasis, and hemangioma. Our experience indicates that sonographic angiography depicts characteristic vascular features that reflect the vascular anatomy of specific types of hepatic tumors, and thus is useful in the differential diagnosis of these lesions.

Carbon Dioxide↗