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Biomedical subjects

Y Doi

Publications and source records attributed to Y Doi.

At least 487 records · Page 27Linked to original sources
PubMed1984

[A case of urinary schistosomiasis in a Japanese male].

Urinary schistosomiasis is an endemic disease mainly distributed in most of Africa and Southwest Asia, and caused by infestation with Schistosoma haematobium. The case presented here was a 33-year-old Japanese male who had suffered from schistosomal infestation in the endemic area, and diagnosed as urinary schistosomiasis by detection of Schistosoma haematobium ova in urine and specimens obtained by mucosal biopsy of the bladder. Radiographic and endoscopic examinations revealed neither obstructive uropathy nor urothelial malignancy. The patient underwent treatment with antimonyl sodium tartrate (Stibnal), and the disease is under good control.

Adult↗
PubMed1983

ESR spectra of VO2+ ions adsorbed on calcium phosphates.

The ESR spectra of oxovanadium(IV) ions, (VO2+), adsorbed on hydroxyapatite(OHAp), fluorhydroxyapatite(FHAp), Mg-containing tricalcium phosphate(Mg-TCP), .octacalcium phosphate (OCP), dicalcium phosphate dihydrate (DCPD), and amorphous calcium phosphate(ACP) were measured at room temperature. The ESR parameters of VO2+ adsorbed on these compounds were slightly different from one another and accordingly, the ESR technique by use of VO2+ was useful for an analysis of the calcium phosphates precipitated from supersaturated solutions. The ESR parameters of VO2+ adsorbed on ACP and Mg-TCP were found to be very similar to each other, suggesting that ACP and TCP resemble each other in the structure of their crystal surfaces.

Adsorption↗
PubMed1983

The accuracy of occlusal cusp height in cast crowns.

Despite a good fit at the finish line, the occlusal cusp height decreased about 80 micron in gypsum-bonded cristobalite investments and increased about 40 micron in phosphate-bonded investments. Disks, tested as simulated occlusal portions of cast crowns, produced similar dimensional changes. This finding suggests that the occlusal cusp height is closely related to the thickness of the disk. An asbestos liner used with a gypsum-bonded investment failed to furnish adequate cushioning. The Kaowool liner provided good accuracy to the occlusal portion and finish line of cast complete crowns.

Calcium Sulfate↗
PubMed1983

Microbeam x-ray diffraction analysis of dental calculus.

The crystalline components of human dental calculus were investigated using microbeam x-ray diffraction analysis. Hydroxyapatite and octacalcium phosphate were most frequently found in that portion having porous and zonal structure. In the portion of the homogeneous illustration showing high calcification, whitlockite is a main component. Brushite was unexpectedly rare, and no calcite was detected in any portion of human dental calculus. The mechanism of the formation of dental calculus being considered in this paper is that octacalcium phosphate or brushite is formed during the initial stage of calcification of dental plaque, and is gradually hydrolyzed and transformed into hydroxyapatite and/or whitlockite.

Calcium Phosphates↗
PubMed1983

Reexamination of the effect of urinary kallikrein on renin release: evidence that kallikrein does not release renin but protects renin from destruction.

Previously, we showed that superfusion of rat kidney slices by rat urinary kallikrein stimulated renin release. The resin measurements were performed on superfusion samples which we stored frozen at -20 C for 24 h. In this study we investigated the effect of freezing on the renin concentration of superfusion samples in the control period. The renin concentration measured immediately without freezing was 9.8 +/- 2.4 ng angiotensin I/10 ml . 3 h/mg tissue, while the concentration in the samples frozen for 24 h was 2.9 +/- 1.0 ng angiotensin I/10 ml . 3 h/mg. The renin concentration of the superfusion samples during the kallikrein perfusion period was the same as that of the nonfrozen control samples. It appeared, therefore, that kallikrein acted as if it stimulated renin release from kidney slices, when the renin was measured in frozen samples. To clarify this phenomenon, we added kallikrein, inactivated kallikrein, and albumin to superfusion samples of the control period and froze the samples for 24 h. After freezing, the renin concentration of the control samples decreased to about 20% of that of nonfrozen samples, except in those samples to which the various proteins were added. In these samples, the loss of renin activity was prevented. The addition of Trasylol, a specific inhibitor of kallikrein, blocked the protective effect of both kallikrein and albumin. These data suggest that the renin released into the superfusion media of kidney slices is destroyed by freezing and that kallikrein or BSA prevents this destruction. These data negate previous data indicating that kallikrein stimulates renin release.

Animals↗
PubMed1983

Effect of mental stress on R wave amplitude of the electrocardiogram in young healthy male subjects.

The electrocardiographic effects of mental arithmetic stress were studied in 19 young, healthy male subjects. Blood pressure was measured by the cuff method before and during mental stress and electrocardiogram (V5) was monitored and recorded continuously throughout the study using a computerized ECG monitoring system. Heart rate increased from 65.8 +/- 7.0 (mean +/- standard deviation) to 76.7 +/- 9.9 beats/min (p less than 0.001). Systolic blood pressure rose from 122.7 +/- 9.6 to 129.1 +/- 11.7 mmHg (p less than 0.05), diastolic blood pressure from 76.2 +/- 8.8 to 83.0 +/0 11.0 mmHg (p less than 0.001), and mean blood pressure from 91.7 +/- 7.9 to 98.5 +/- 10.1 mmHg (p less than 0.001). These changes were all statistically significant. R wave amplitude decreased significantly from 18.6 +/- 6.9 to 17.0 +/- 6.5 mm for the group (p less than 0.001). No changes in the ST segment were observed; ST depression decreased from 0.56 +/- 0.47 to 0.54 +/- 0.43 mm (N.S.) and ST slope from 0.87 +/- 0.59 to 0.77 +/- 0.63 mm/sec (N.S.). Thus it is apparent that mental stress reduced R wave amplitude without causing ST segment changes in young, healthy subjects. The mechanism and clinical implications are discussed.

Adult↗
PubMed1983

Elevation of plasma renin activity during pregnancy and rupture of a dissecting aortic aneurysm in a patient with primary aldosteronism.

This is a case report of a 37-year-old Japanese woman with primary aldosteronism who was found to have high plasma renin activity during toxemia of pregnancy and who died of a dissecting aneurysm of the aorta about 2 years later. The autopsy findings showed cystic medial necrosis in the aorta and a right adrenocortical adenoma. The dissecting aneurysm in this case is probably related to hypertension and cystic medial necrosis. A definite diagnosis of primary aldosteronism cannot be made during toxemia of pregnancy, and it is necessary to do serial determinations of plasma renin activity and plasma aldosterone concentration after delivery to confirm the diagnosis.

Adenoma↗
PubMed1983

Adrenal renin: a possible regulator of aldosterone production.

We have confirmed the presence of adrenal renin and have shown that the concentration is much higher in the glomerulosa cells. The renin concentration of these cells is influenced by changes in sodium balance and after nephrectomy, while the renin of the fasciculata-medullary tissue is not. There is a positive correlation between adrenal renin and aldosterone concentration. The data suggest that adrenal renin may be a local hormone that plays a role in the regulation of aldosterone production.

Adrenal Glands↗
PubMed1982

ESR and IR studies of carbonate-containing hydroxyapatites.

Synthetic carbonate-containing and carbonate-free hydroxyapatites(CO3-HA and CO3-free HA) have been investigated using ESR and IR absorption, together with X-ray diffraction and chemical analyses. Comparison of the IR spectra between 13C-enriched 13CO3-HA and 12CO3-HA prepared at 100 degrees C and at high pH suggested that the carbonate substitutes for PO4 but not for HPO4. The substitution of CO3 for PO4 in this case resulted in elimination of hydroxyl ions in a hexad axis. The elimination of hydroxyl ions was found to be related to the decrease in crystallinity for the c-axis direction, although so far there has been no direct evidence for the existence of hydroxyl deficiencies. In the case of CO3-free HAs prepared at 80 degrees, 60 degrees, 40 degrees, and 20 degrees C, the decrease in crystallinity accompanied by the decrease in the temperature for preparation was associated with the decrease in crystal size, and no significant elimination of hydroxyl ions would be expected in the absence of the carbonate.

Carbon Isotopes↗
PubMed1982

Rate of rise of the carotid pulse. An investigation of observer error in a common clinical measurement.

Bedside estimation of the rate of rise of the carotid pulse is a standard clinical observation whose reliability has not been determined. To ascertain interobserver agreement (primary objective) and compare the velocity of rise of the carotid displacement (not pressure) pulse (supplementary objective), three blinded observers evaluated, ranked and palpated the velocity of rise of carotid pulse as "unremarkable," "slow" or "rapid" in 20 consecutive patients. The relative rate of rise of the recorded carotid pulse was represented by the angle between baseline and the initial carotid peak at a standard paper speed of 100 mm/s. Chi-square analyses yielded no significant interobserver agreements (probability [p] 0.22 to 0.51). There was also no correlation of observers' ranking of rise of carotid pulse with the ranking from independent measurement of the recorded pulse rise velocity (p = 0.10 to 0.99). Observer agreement was unanimous only four times and even in these instances was consistent with the recorded carotid pulse rise velocity only once. The results suggest that unbiased observers cannot reliably discriminate slow from "normal" velocity of rise of carotid pulse.

Adult↗