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Biomedical subjects

M Inui

Publications and source records attributed to M Inui.

At least 109 records · Page 6Linked to original sources

The adreno-sympathetic system, the genetic predisposition to hypertension, and stress.

The blood pressure, heart rate, and plasma catecholamine (CA) response to standing and mental stresses were studied in 14 normotensive subjects with normotensive parents (PNT group), 14 normotensive subjects with hypertensive parent(s) (PHT group), and eight borderline hypertensive patients (BHT group). Mean basal plasma norepinephrine (NE) concentration in BHT group (302 +/- 94 pg/ml) and PHT group (289 +/- 167 pg/ml) were significantly higher than in PNT group (205 +/- 76 pg/ml). Significant differences in the mean basal plasma epinephrine (E) were found only between the PNT and BHT groups (22 +/- 12 vs 43 +/- 18 pg/ml, p less than 0.01). Both plasma NE and E increased significantly on standing in all groups. With mental stress, plasma E increased significantly, though plasma NE did not change significantly in all three groups. The mean changes in blood pressure, heart rate, and plasma CA in response to standing and mental stresses were not different in the three groups. However, a higher incidence (50%) of high blood pressure responders (greater than or equal to 20 mmHg in systolic blood pressure) to mental stress was found in the PHT group compared with PNT (14%) and BHT (12%). The high responders in the PHT group had significantly higher mean plasma E concentrations throughout the experiment. Also, their increases in plasma NE and E in response to mental stress were higher than those of the low responders. The results indicate that genetic predisposition to hypertension plays a significant role in determining plasma catecholamine levels and the responsiveness to stress, especially to mental stress.

Adolescent

Tay-Sachs disease associated with precocious puberty.

A girl with Tay-Sachs disease developed enlargement of the mammary glands at the age of 4 years and menstruation at the age of 6 years. It was demonstrated that the precocious puberty in this patient was due to the hypersecretion of gonadotropins.

Child

Development of quantitative analysis of plasma thromboxane B2 by gas chromatography-mass spectrometry.

In order to diagnose patients in thrombotic state, it is quite important to detect increased concentration of plasma thromboxane B2 (TXB2), a stable catabolite of TXA2. To determine plasma TXB2 levels with high sensitivity and selectivity, we employed gas chromatography-mass spectrometry (GC/MS). The trimethylsilyl (TMS) ether derivatives conventionally employed in GC/MS analysis of prostanoids are not suitable for quantitation of plasma prostanoids, because the mass spectra are deficient in ions with high intensity in the high mass range and TMS ether derivatives are sensitive to moisture. To solve these problems we employed tert-butyldimethylsilyl (t-BDMS) ether derivatives, based on the observation that t-BDMS ether derivatives afforded abundant ions at [M-57]+ and showed good hydrolytic stability. The reaction conditions of tert-butyldimethylsilylation were also examined to optimize the selected ion monitoring response. The t-BDMS ether derivatives of prostanoids were successfully analyzed with a short capillary column with a relatively large diameter, with maintaining good separation. In conjunction with the use of reversed-phase high performance liquid chromatography as purification procedure, a sensitive and reproducible stable isotope dilution assay of plasma TXB2 was developed. The values obtained by this method correlated well with those obtained by the radioimmunoassay we have developed.

6-Ketoprostaglandin F1 alpha

Energy level in large intestinal mucosa in patients with ulcerative colitis.

In 7 patients with ulcerative colitis, the energy level in the large intestinal mucosa was investigated. ATP and energy charge in the intestinal mucosa in ulcerative colitis showed lower levels than those of control subjects. Therefore, energy-deficit may exist in the large intestinal mucosa in ulcerative colitis.

Adenine Nucleotides

[Effect of obstructive jaundice on acute gastric ulceration viewed from gastric mucosal energy metabolism in rats].

The mechanism of acute gastric ulceration in rats with obstructive jaundice was investigated in terms of the changes in the gastric mucosal energy metabolism. Rats were divided into 4 groups as follows: control, vagotomized, jaundiced, and jaundiced and vagotomized group. The water immersion and restraint procedures were performed and the ulcer index was calculated. The change of energy metabolism in the gastric mucosa of corpus and antrum was clarified by measuring ATP and energy charge. The following results were obtained: Vagotomized group showed significant decreased ulcer index, however, the gastric mucosal energy metabolism were unchanged compared to the control group after stress. Jaundiced group showed significant higher ulcer index, and the early, significant depression of the gastric mucosal energy metabolism compared to the control group. Jaundiced and vagotomized group showed significant improvement of ulcer index and gastric mucosal energy metabolism compared to the jaundiced group. The gastric energy metabolism of the corpus revealed more prominent depression than that of the antrum in jaundiced group, and jaundiced and vagotomized group. These data suggested that the deterioration of the gastric mucosal energy metabolism after stress was enhanced under the condition of obstructive jaundice and these results were improved by vagotomy.

Acute Disease

Caldesmon, a calmodulin-binding, F actin-interacting protein, is present in aorta, uterus and platelets.

Caldesmon, a protein originally found in chicken gizzard, was concluded also to be present in bovine aorta, uterus, and human platelets by demonstration of a protein with the following properties: (a) Ca2+-dependent calmodulin-binding; (b) binding to F actin in such way that the binding was broken on Ca2+-dependent binding of calmodulin; (c) cross-reactivity in immune blotting procedures with affinity-purified antibody against gizzard caldesmon; (d) similar subunit Mr-values on SDS-gel to those of gizzard caldesmon. Like gizzard caldesmon, platelet caldesmon was composed of two polypeptide bands of Mr 150 000 and 147 000, but caldesmon in aorta and uterus gave a single band of Mr 150 000. A polypeptide of Mr 165 000 that was immunologically distinct from caldesmon but, like caldesmon, bound to calmodulin and F actin in a flip-flop fashion, was also demonstrated in aorta and uterus.

Animals

Effects of phospholamban phosphorylation catalyzed by adenosine 3':5'-monophosphate- and calmodulin-dependent protein kinases on calcium transport ATPase of cardiac sarcoplasmic reticulum.

To elucidate the role of 22000-dalton protein phospholamban, a putative regulator of Ca2+-dependent ATPase of cardiac sarcoplasmic reticulum, we examined the relationship between cyclic AMP- and calmodulin-dependent phosphorylation of phospholamban and their effects on ATPase activity and calcium transport of cardiac sarcoplasmic reticulum. Cardiac microsomes were incubated with [gamma-32P]ATP or unlabeled ATP, catalytic subunit of cyclic AMP-dependent protein kinase and/or exogenous calmodulin, and subsequently assayed for ATPase activity and calcium uptake by cardiac sarcoplasmic reticulum. Cyclic AMP-dependent phosphorylation of phospholamban was independent of Ca2+, whereas calmodulin-dependent phosphorylation of phospholamban was dependent on Ca2+ within a range between 0.2 and 50 microM. Cyclic AMP- and calmodulin-dependent phosphorylation of phospholamban occurred independently; when both kinases were operative, the amounts of phosphorylation were additive. Under these conditions, the phosphoproteins formed by cyclic AMP- and calmodulin-dependent protein kinases electrophoretically migrated as 11000-dalton components when sodium dodecyl sulfate-solubilized phosphoproteins were boiled prior to polyacrylamide gel electrophoresis. The ATPase activity was stimulated by either cyclic AMP- or calmodulin-dependent phosphorylation of phospholamban at Ca2+ concentrations up to 2 microM. The extents of stimulation of ATPase activity were additive when both types of phosphorylation were functional. Calcium uptake was similarly augmented by cyclic AMP- and/or calmodulin-dependent phosphorylation of phospholamban. These results indicate that Ca2+-dependent ATPase and calcium transport of cardiac sarcoplasmic reticulum are regulated by phospholamban phosphorylation catalyzed by cyclic AMP- and calmodulin-dependent protein kinases, thus suggesting a dual role of phospholamban in active calcium transport.

Biological Transport, Active

Effect of quercetin on two-stage carcinogenesis of the rat urinary bladder.

The initiating and promoting effects of quercetin on urinary bladder carcinogenesis in male F344 rats were examined histopathologically. No tumor or hyperplasia were observed in rats given 5.0% quercetin as initiator in the diet for 4 weeks followed by 0.001% N-butyl-N-(4-hydroxybutyl) nitrosamine (BHBN) for 29 weeks. Moreover, administration of 5.0% quercetin diet for 25 weeks after initiation with 0.01% BHBN for 4 weeks did not promote urinary bladder carcinogenesis. Furthermore, no lesions were detected in rats given 5.0% quercetin diet only. These results suggest that quercetin is not carcinogenic to rat urinary bladder.

Animals

Cardiac beat-to-beat variation as an indicator of neuropathy and the frequency of its abnormality in diabetes mellitus.

The cardiac beat-to-beat variation and the maximum constriction velocity and acceleration of the pupillary light reflex have been considered indices of parasympathetic neuropathy. The abnormality of these indices was evaluated in 191 non-diabetics and 151 diabetics. The cardiac beat-to-beat variation decreased gradually with age in non-diabetics as well as diabetics. It was small in diabetics compared to non-diabetics in corresponding age group between 10 and 59 years. In diabetics it was still smaller in the presence of peripheral neuropathy than in its absence. The overall prevalence of this abnormality was 30.1% in diabetics but only 3.0% in non-diabetics. In diabetics it rose to 40.0, 42.6 and 52.2% in the presence of motor, sensory and motor plus sensory nerve neuropathy, respectively. In 63 diabetics examined for both cardiac beat-to-beat variation and pupillary light reflex, no statistical difference was observed between the frequency of these abnormalities. These observations indicate an extremely high prevalence of abnormality in autonomic nerve function in diabetics especially in the presence of abnormality in autonomic nerve function in diabetics especially in the presence of other types of neuropathy, so that diabetics with peripheral neuropathy should be carefully examined for autonomic neuropathy and vice versa. Besides, the measurement of the cardiac beat-to-beat variation is similar in sensitivity in the detection of neuropathy to the measurement of pupillary light reflex.

Adolescent

Actin polymerization induced by calspectin, a calmodulin-binding spectrin-like protein.

We have purified from a membrane fraction of bovine brain a calmodulin-binding protein (calspectin) that shares a number of properties with erythrocyte spectrin: It has a heterodimeric structure with Mr 240 000 and 235 000 and binds to (dimeric form) or crosslinks (tetrameric form) F-actin. We show that calspectin (tetramer) is capable of inducing the polymerization of G-actin to actin filaments by increasing nucleation under conditions where actin alone polymerizes at a much slower rate. Thus, brain calspectin behaves in the same manner as erythrocyte spectrin, supporting the idea that, in conjunction with actin oligomers it comprises the cytoskeletal meshwork underlying the cytoplasmic surface of the nerve cell.

Actins

Anomalous origin of the left coronary artery.

Two autopsy cases of anomalous coronary artery were reported. The patients were a schoolgirl and a schoolboy, who died suddenly during physical exercise at the age of twelve. At postmortem examination in both cases the left coronary artery arose at the comissure from aorta, and in one case the left coronary ostium was completely obstructed with fibrous tissue, whereas in the other case it was severely stenotic. The cause of anomalous ostial position should be regarded as congenital, but the complete occlusion and severe stenosis at the orifice seemed to be modified by several factors--both congenital acquired. For the prevention of sudden death caused by this anomaly, cardiac angiography would have been necessary at the outset of anginal pain.

Arteries