Hidenori Maezawa

Hereditary Factors in Takayasu's Disease

In an attempt to provide support for the genetic link theory as related to the etiology of Takayasus disease, we analyzed simultaneously A, B, and D loci of HLA antigens in 75 Japanese patients with the disease. Serving as control were 128 healthy Japanese. A statistically significant high frequency of BW52 and DHO was confirmed with the levels being 25.6 and 10.4, respectively, in the X2 test. A haplotype of A9-BW52-DHO was frequently evident in these patients as compared to the controls, and here also the statistical difference was significant. There appears to be a closer relationship of the gene to BW52 than to DHO. A survey of the homozygote of BW52 revealed 6 of 75 patients with BW52; however, statistically speaking, this rate did not differ from the expected one. Thus, our analysis of HLA illustrates the genetic factors involved in Taka yasus disease. The genes are located between the B and D loci and are closer to BW52 than DHO and these genes have a dominant character.

Thallium-201 stress scintigraphy in Takayasu arteritis

Thirty-eight women with Takayasu arteritis were studied using thallium-201 stress myocardial scintigraphy to assess the prevalence and pathophysiology of the perfusion abnormality. Twenty (53%) had abnormal scintigraphic findings (group A). Abnormal scans were divided into 3 groups: permanent defects in 6, reversible defects in 7 and slow washout in 7. The remaining 18 patients had normal scintigrams (group N). Group A had a tendency to be older and to have a high prevalence of complicated significant aortic regurgitation. Interventricular thickness plus left ventricular posterior wall thickness (26 +/- 7 vs 17 +/- 2 mm, p less than 0.01) and left ventricular mass (267 +/- 121 vs 133 +/- 39 g, p less than 0.01) were all greater in group A on echocardiography. The mean value of the central aortic pressure in systole was 170 +/- 15 mm Hg in the 7 catheterized patients in group A. Coronary ostial stenoses were present in 2 group A patients who showed reversible defects on scintigrams. These data indicate that the abnormal perfusion detected by imaging in patients with Takayasu arteritis was responsible for a decrease in coronary reserve or myocardial damage, or both, due to long-standing systemic hypertension or aortic regurgitation. Coronary artery disease should be considered if a reversible defect is present.

Morphological and functional differentiation of cultured vascular smooth-muscle cells

SummaryIn numerous investigations using cultured smooth-muscle cells, investigators have consistently added 10–20% fetal calf serum (FCS) to the medium to maintain viable cells. In the present study we utilized an optical technique to investigate whether smooth-muscle cells, cultured with or without FCS, maintain their contractile activity in vitro. With such optical measurement, we were able to detect signals due to spontaneous contractions, in muscle cells cultured in FCS-free medium for up to 8 days, and, for the first time, were also able to observe the conduction of these cell contractions.The ultrastructural characteristics of cultured smooth-muscle cells during contractile activity, were also examined by electron microscopy. The cells were mature and well-differentiated, and were packed with numerous myofilaments. They had developed long cell processes, and were linked to one another by gap junctions.These observations indicated that the smooth-muscle cells, cultured without FCS for 7 to 8 days, were morphologically mature and maintained their contractile activity, whereas the cells cultured in FCS-containing medium showed no detectable signs of contractile activity.

A radioimmunoassay of thromboxane B2 with thromboxane B2-125I-tyramide and its application to the study on the thromboxane B2 formation during platelet aggregation

Abstract A radioimmunoassay for measuring thromboxane B2 with thromboxane B2-125I-tyramide was developed. Antibody to thromboxane B2 that was produced in rabbits immunized with conjugates of thromboxane B2 coupled to bovine serum albumin had a high specificity to thromboxane B2 Thromboxane B2-125I-tyramide had a high affinity to antiplasma of thromboxane B2. This method was utilized to study thromboxane B2 formation during platelet aggregation induced by collagen, ADP and adrenalin. Formations of thromboxane B2 were observed in accordance with platelet secondary aggregation, namely, release reaction.

Microassay of cyclic nucleotides in vessel wall: V. Simultaneous assay of cyclic AMP and cyclic GMP

Abstract Cyclic GMP (cGMP) is an important key substance in cell function; however, the related mechanisms have not been entirely elucidated, as the content of this nucleotide within the cell is so small that an accurate estimation is difficult. We designed a microassay for cyclic GMP in 500 μg dry weight of tissue samples, using succinylation, and were able to assay, separately, the content of cyclic GMP in the intima or media of the arterial wall. In addition, we attempted to develop a method for a simultaneous determination of both cyclic AMP and cyclic GMP in a small amount of the same assay mixture. Five hundred micrograms dry weight of intima or media of rabbit aorta was prepared under a stereomicroscope. After deproteinization and lyophilization, the samples were dissolved with 60 μl of H 2 O and 30 μl of succinylation mixture. After succinylation, 40 μl of each of the tissue extractions was sampled to determine the levels of cyclic AMP and cyclic GMP. The radioimmunoassay was performed, using Yamasas kit. The recovery rates of cyclic AMP and cyclic GMP in our method were 86.2 ± 1.2 and 87.6 ± 1.3%, respectively. The levels of cyclic GMP in the intima and media of aorta of cow, pig, and rabbits were estimated to be, intima: 0.18 ± 0.02, 0.06 ± 0.03, and 0.20 ± 0.01 pmole/mg protein, media: 0.08 ± 0.01, 0.04 ± 0.01, and 0.09 ± 0.01. The cyclic GMP levels in the intima of aorta of cow and rabbits were high compared to levels in the media and this difference was statistically significant ( P

Microassay of adenine nucleotides in intima and media of the aortic wall

Abstract Combining a quantitative histochemistry method with the Firefly luciferase method we found that adenosine-triphosphate (ATP) could be accurately measured in 100 to 200 μg of aortic tissue. Trichloracetic acid solution was used for extraction of ATP and by so doing, weighing at the freezing point or neutralization by (potassium hydroxide) KOH in case of perchloric acid could be eliminated. Simultaneous assay of cyclic nucleotides was thus feasible. Contents of ATP and ADP in intima and media of aortic wall of rabbits, cows, and pigs and levels of these nucleotides in atherosclerotic lesions of aorta of rabbits fed a 1% cholesterol containig diet for 15 weeks were measured. Levels of adenine nucleotides in atherosclerotic lesions of rabbits were low compared to levels in intima of the aortic wall. Acquisition of these data is vital for monitoring changes in levels of adenine nucleotides in relation to pathological changes in tissues.

Relationship between the R-R interval variation and metabolic states of diabetes

To investigate whether the metabolic state of diabetes affects the R-R interval variation, 82 diabetics were studied at intervals of about 1 month and of about 1 year. There was no significant relationship between the rate of change for FBG and that for R-R interval variation at both these intervals. However, in the cases that showed a change of HbA1 by more than 10% in a month, the rate of change for the R-R interval variation was 20 +/- 30% in the group with improved HbA1 and -9 +/- 17% in the group with aggravated HbA1, demonstrating a significant difference (P less than 0.05) between the 2 groups. There was a significant difference (P less than 0.02) in the rate of change for the R-R interval variation between the group with improved HbA1 by more than 5% and the group with aggravated HbA1 by more than 5%, when measured at intervals of 1 year. No special relationship was observed between the difference in R-R interval variation and each of the following: (1) the mean FBG for 1 year preceding the day of initial measurement of the R-R interval variation; (2) the mean FBG for the succeeding year; and (3) the difference in these 2. It was suggested that the R-R interval variation was likely to be affected by the metabolic state during the preceding 1-2 months.

Augmentation of urinary amylase output by excessive diuresis in rats and abolition of this phenomenon by pancreatectomy

SummaryEffects of diuresis on urinary amylase output were observed in control and pancreatectomized rats on the administration of tap water, glucose and amino acid solution.(1)Urine volume and urinary amylase output were increased as the concentration of glucose solution was increased. Amylase output in the urine revealed a positive correlation with the urine volume.(2)Augmentation of urinary amylase output was also observed in diuretic rats produced by the administration of amino acid solution.(3)Augmentation of urinary amylase output was not found in pancreatectomized rats, although the urine volume was more pronouncedly increased compared to control rats.(4)The urinary amylsae output revealed a positive correlation with the ratio of amylase clearance to creatinine clearance by the kidney in control rats, while the output remained unchanged over relatively wide range of the ratio in pancreatectomized rats. Above evidences indicated that urinary amylase output was significantly augmented by excessive diuresis and that the increased urinary amylase output originated from the pancreasEffects of diuresis on urinary amylase output were observed in control and pancreatectomized rats on the administration of tap water, glucose and amino acid solution. (1) Urine volume and urinary amylase output were increased as the concentration of glucose solution was increased. Amylase output in the urine revealed a positive correlation with the urine volume. (2) Augmentation of urinary amylase output was also observed in diuretic rats produced by the administration of amino acid solution. (3) Augmentation of urinary amylase output was not found in pancreatectomized rats, although the urine volume was more pronouncedly increased compared to control rats. (4) The urinary amylsae output revealed a positive correlation with the ratio of amylase clearance to creatinine clearance by the kidney in control rats, while the output remained unchanged over relatively wide range of the ratio in pancreatectomized rats. Above evidences indicated that urinary amylase output was significantly augmented by excessive diuresis and that the increased urinary amylase output originated from the pancreas Urine volume and urinary amylase output were increased as the concentration of glucose solution was increased. Amylase output in the urine revealed a positive correlation with the urine volume. Augmentation of urinary amylase output was also observed in diuretic rats produced by the administration of amino acid solution. Augmentation of urinary amylase output was not found in pancreatectomized rats, although the urine volume was more pronouncedly increased compared to control rats. The urinary amylsae output revealed a positive correlation with the ratio of amylase clearance to creatinine clearance by the kidney in control rats, while the output remained unchanged over relatively wide range of the ratio in pancreatectomized rats. Above evidences indicated that urinary amylase output was significantly augmented by excessive diuresis and that the increased urinary amylase output originated from the pancreas

Further studies on the sodium retaining activity of liver extract

ConclusionFazekas and Fazekas (1966) showed that aldosterone in the liver was extracted as the supernatant of acetone-treated homogenate. In our study the sodium-retaining substance was always demonstrated in the precipitant, so it seemed to be quite different from aldosterone.

Sodium retaining substance in liver extract

Recently it was demonstrated by us that the liver extract obtained from normal and also bilaterally adrenalectomized rats inhibited definitely the excretion of sodium but did not stimulate the excretion of potassium. In this representation, the activities of the extracts were studied on urine volume and excretion of electrolytes. On the preparation of the extract, the livers of 3 or more rats were homogenized with 10% sucrose solution which was added at the rate of one or 3 ml to each one gram of liver, and then centrifuged at 17,000Xg for 15 minuites at 4~ The supernatant thus obtained were utilized as the liver extract. On the observations of the effects of the extract on urine volume and the excretion of electrolytes, the extracts were injected with 5 ml of distilled water intraperitoneally into the rats. 1) After the injection of 0.25~1.0ml of 1 : 1 extract, urine volume and the excretion of sodium and chloride were decreased in accordance with the increase of the dosis. However the excretion of potassium was not changed by the extract. 2) The response of adrenalectomized rats to the extract were significantly larger than that of sham-operated rats on the decrease of urine volume and excretion of sodium and chloride (p<0.05). 3) There was no significant difference between the effects of liver extracts obtained from sham-operated and adrenalectomized rats on the 8th day af ter the operation. 4) This active substance in the extract was heat-labile and non-dialysable.