Long-term effects of dietary polychlorinated biphenyl and high level of vitamin E on ascorbic acid and lipid metabolism in rats

Long-term feeding of purified diets containing (per kg diet) 100 mg of polychlorinated biphenyl (PCB) and 1000 mg of vitamin E (RRR-alpha-tocopheryl acetate) to male Wistar rats was carried out. Rats fed a diet containing PCB rapidly became hypercholesterolemic and maintained high cholesterol levels throughout the 240 d of the experiment. Rats fed a high dietary level of vitamin E plus PCB had higher serum cholesterol and lower liver cholesterol than rats fed a lower level of vitamin E plus PCB. In rats fed PCB, urinary excretion of ascorbic acid was higher than in rats not fed PCB. Urinary ascorbic acid was lower in rats fed high levels of vitamin E plus PCB than in those fed the normal levels of vitamin E plus PCB. Rats fed PCB had lower liver vitamin A storage and higher vitamin A in kidney than rats not fed PCB. This implies that a redistribution of vitamin A occurred in rats fed PCB. Histological observations revealed that central halves of the hepatic lobules of rats fed PCB showed distinct changes consisting of hypertrophy of hepatocytes in the perivenous region and accumulation of vacuoles (lipid droplets) in the cells in the remaining affected portion. Administration of a high dose of vitamin E could not ameliorate this lesion while the treatment depressed effectively the lipid peroxidation. This suggests that the lipid peroxidation was not responsible for the hepatic damage induced by PCB.

In vitro calcification in human osteoblastic cell line derived from periosteum

Human osteoblastic cell cultures were established from human periosteum, identified on the basis of high alkaline phosphatase activity in the confluent state. The cells in the growing state showed a fibroblastic morphology and grew to form multiple layers. The cells could spontaneously calcify, and the process was accelerated by alpha-glycerophosphate. Minerals deposited on the cells consisted exclusively of calcium and phosphorus, and matured into hydroxyapatite crystals. The calcification was stimulated by the treatment with 1 alpha,25-dihydroxy-vitamin D3. These results indicate that the osteoblastic cells have the capacity to differentiate into osteocytes and form calcified human bone tissue in vitro.

Effects of intranasal administration of atrial natriuretic hormone on spontaneously hypertensive rats

The effects of the intranasal administration of synthetic alpha-human atrial natriuretic polypeptide (alpha-hANP) were investigated in 14 anesthetized spontaneously hypertensive rats (SHR; Okamoto-Aoki strain). They were given intranasally synthetic alpha-hANP in distilled water at doses of 10 micrograms/kg, 50 micrograms/kg and 100 micrograms/kg. Intranasal application of 200 microliter of distilled water as a control was also performed in 3 anesthetized SHR. Sixteen anesthetized SHR were examined for the effects of intravenous administration of alpha-hANP at doses of 4 micrograms/kg, 10 micrograms/kg, 20 micrograms/kg and 40 micrograms/kg. Urinary volume and the urinary excretion of sodium increased 2- to 3-fold during the 50 minutes following intranasal administration of a single dose of 50 micrograms/kg or 100 micrograms/kg, although neither the urinary volume nor the urinary excretion of sodium increased after intranasal administration of 10 micrograms/kg of alpha-hANP or 200 microliter of distilled water. There were no significant changes in arterial pressure or heart rate after the intranasal administration of synthetic alpha-hANP or distilled water. In contrast, arterial pressure was decreased and urinary volume and urinary excretion of sodium were increased, in a dose dependent manner, within 5 minutes after intravenous bolus-injection of alpha-hANP and returned to their baseline levels within 20 minutes. These results indicate that intranasal administration of synthetic alpha-hANP exerts its diuretic effect without concomitant changes in arterial pressure or heart rate in SHR.

Vitamin D3 metabolism in idiopathic osteonecrosis of femoral head

Eighteen cases of idiopathic osteonecrosis of the femoral head were studied. Serum concentrations of 25(OH)D3, 24, 25(OH)2D3 and 1,25(OH)2D3 were 19.4 +/- 8.7 ng/ml, 1.04 +/- 0.44 ng/ml and 16.7 +/- 7.9 pg/ml (mean +/- SD) respectively. These values were significantly lower than those of control (26.5 +/- 15.5 ng/ml, 1.91 +/- 0.77 ng/ml and 26.9 +/- 13.7 pg/ml, respectively) (p less than 0.01). Abnormal values of serum calcium (Ca) were detected in two cases, inorganic phosphate (iP) in two cases and alkaline phosphatase (Al-Pase) in two others with no other abnormal values in blood biochemistry. Histological findings in nine cases of iliac bone were those of osteomalacia in five cases and those of osteoporosis in four cases. These results suggest the possibility of bone metabolism abnormalities due to abnormal vitamin D3 metabolism as a background of osteonecrosis of the femoral head.

Effect of dietary ascorbic acid, cholesterol and PCB on cholesterol concentrations in serum and liver in a rat mutant unable to synthesize ascorbic acid

The effect of ascorbic acid deficiency and excessive ascorbic acid intake on serum and liver levels of cholesterol and lipids was investigated in ODS-od/od (OD) rats fed a normal diet, a cholesterol-containing diet or a polychlorinated biphenyl (PCB)-containing diet. The OD rat is a rat mutant unable to synthesize ascorbic acid. In OD rats, the dietary requirement of ascorbic acid to maintain normal growth and normal levels of cholesterol in serum and liver is about 300 mg of ascorbic acid/kg diet. In control (ODS-+/+) rats that can synthesize ascorbic acid, dietary addition of 0.5% cholesterol and 0.25% cholic acid caused elevation of cholesterol concentrations in serum and liver, elevation of total lipids in liver and reduction of the ratio of high density lipoprotein (HDL) cholesterol to total cholesterol in serum. Dietary addition of PCB (200 mg/kg diet) caused elevation of serum concentration of cholesterol and of the ratio of HDL-cholesterol to total cholesterol in serum. In OD rats fed a normal diet, ascorbic acid deficiency slightly elevated serum concentration of cholesterol, elevated liver concentration of cholesterol and reduced the ratio of HDL-cholesterol to total cholesterol in serum; and ascorbic acid excess did not affect serum and liver concentrations of cholesterol and the ratio of HDL-cholesterol to total cholesterol in serum. In OD rats fed a cholesterol-containing diet, ascorbic acid deficiency elevated serum and liver concentrations of cholesterol, and did not affect the ratio of HDL-cholesterol to total cholesterol in serum; and ascorbic acid excess did not affect serum and liver concentrations of cholesterol and the ratio of HDL-cholesterol to total cholesterol in serum.(ABSTRACT TRUNCATED AT 250 WORDS)

Capacitation-related changes in antigen distribution on mouse sperm heads and its relation to fertilization rate in vitro

The anti-mouse sperm monoclonal antibody OBF13 did not react with fresh epididymal sperm. However, when sperm were incubated in a culture medium capable of inducing capacitation, the entire head of the sperm began to react with this antibody. This change of reactivity was not observed when sperm were incubated in a Ca2+-free medium. The change of the reactivity to the antibody was studied in relation to the fertilizing ability of sperm as measured in an in vitro fertilization system; a significant correlation was observed between the appearance of head-stained sperm and fertilization rate.

Characterization of a kidney antigen defined by a mouse monoclonal antibody K2.7

Analysis by indirect immunoperoxidase staining of tissues demonstrated that monoclonal antibody (mAb) K2.7 derived from a mouse immunized with a renal cancer cell line OS-RC-2 was reactive with the tissues of all 36 normal kidneys examined, including two fetal kidneys, 22 of 25 renal cell carcinomas (RCCs) and one of 15 gastric cancers, but not with 23 normal tissues from 11 different organs or 41 malignant tissues from 10 different organs. mAb K2.7 was reactive with the kidneys of several animal species. Positive staining was seen on tubular epithelial cells of the kidney. Thus, the antigen recognized by mAb K2.7 appeared to be an interspecies kidney specific antigen. Results obtained by protein A (PA) assays with a cultured cell panel were consistent with those of staining and confirmed the restricted expression of the antigen. Immunochemical analysis revealed that mAb K2.7 reacted with molecules of 63,000, 60,000 and 43,000 daltons.

Renal haemodynamics and comparative effects of captopril in patients with benign- or malignant-essential hypertension, or with chronic renal failure

Effects of captopril on arterial pressure (AP) and renal function were investigated in patients with non-malignant "benign" or malignant phase essential hypertension (EH group), or with chronic renal failure (CRF group). After captopril administration, AP and renal vascular resistance (RVR) decreased significantly, and renal blood flow (RBF) and plasma renin activity (PRA) increased in both groups. Glomerular filtration rate (GFR) increased in the EH group, but was unchanged in CRF. Filtration fraction decreased in the malignant hypertension and CRF groups. Significant correlations were found between baseline PRA and baseline RVR, and the captopril-induced decrease in mean AP, decrease in RVR, increase in RBF, and increase in GFR in the EH group, while these associations were not observed in CRF. These results indicate that the high AP, RVR, suppressed RBF and GFR in the EH group were closely related to activity of the renin-angiotensin system, but not so the low RBF and GFR in CRF. Small doses of captopril may improve impaired renal function in EH, and may not cause deterioration in the CRF group.

[Quantitation of coronary artery lesions by 2-4 hour stress-myocardial clearance of thallium-201]

The stress-redistribution thallium-201 scintigraphy and thallium-201 washout method have limitations in their ability to detect individual coronary lesions in patients with multivessel coronary artery disease. The purpose of this study is to investigate the value of the quantitative planar method using the dynamics of thallium-201 redistribution after exercise. We observed the patterns of thallium clearance in the late stages (at 2 and 4 hrs) which are characteristic of decreased myocardial blood supply by the obstructed coronary arteries. In 20 subjects, quantitative thallium scintigrams (planar image and circumferential count profile) and blood samples for thallium concentration were obtained immediately, and 2 and 4 hrs after maximal treadmill exercise. Coronary angiography was performed in all subjects, and 16 patients had coronary artery disease (CAD) and four were normal. The rate of thallium clearance from the blood (TCB) was compared with the rate of thallium clearance from each segmental lesion of the myocardium (TCM) between the 2- and 4-hr images. The system adopted for assignment of myocardial regions to individual coronary arteries has been used as an approach to localization of anatomic disease. In the four patients with normal coronary arteries, TCM exceeded TCB in all regions of all images (specificity 100%). Fourteen of the 16 CAD patients had at least one region where TCM was less than TCB (sensitivity 88%). Ten of the 14 patients with multivessel CAD had multiple regions where TCM was less than TCB (sensitivity 71%). All of the six patients without multivessel CAD (four with normal coronary arteries and two with one vessel disease) did not have multiple regions where TCM was less than TCB (specificity 100%). Quantitative thallium scintigraphy showed sensitivities of 86%, 56% and 91% in the left anterior descending artery, the circumflex coronary artery and right coronary artery, respectively. These results showed that decreased TCM in the late stage is characteristic of myocardial regions where blood is supplied by the diseased coronary arteries. This finding may improve diagnostic sensitivity under the condition of multivessel coronary artery disease.

Evaluation of left ventricular residual function using postextrasystolic potentiation. Relation between systolic time intervals and angiographic study

The effects of postextrasystolic potentiation (PESP) on systolic time intervals and left ventricular wall motion were studied during diagnostic cardiac catheterization in 20 patients (4 normal individuals, 11 patients with coronary artery disease and 5 patients with idiopathic dilated cardiomyopathy). Postextrasystolic changes in the aortic pressure and systolic time intervals were measured from the electrocardiogram and aortic pressure tracing. After a micromanometer-tipped catheter was positioned in the ascending aorta just above the aortic valve, a single ventricular premature beat was introduced using an R-wave coupled stimulator. PESP was then studied during left ventriculography which was undertaken simultaneously in the right anterior oblique 30 degrees and left anterior oblique 60 degrees positions. Following two or three normal sinus beats, a right ventricular extrastimulus was delivered again under the same stimulating condition. PESP in all patients caused a decrease in the ratio of the preejection period to the left ventricular ejection time (PEP/ET). The average percent decrease was 21% (from 0.429 +/- 0.162 to 0.339 +/- 0.102, p less than 0.001). The left ventricular ejection fraction (EF) increased in all patients with PESP from 0.52 +/- 0.20 to 0.61 +/- 0.17 (p less than 0.001). The postextrasystolic changes in the PEP/ET ratio and EF were greater in patients with low cardiac performance. There was a good correlation (r = -0.85, p less than 0.001) between the changes in the EF and those in PEP/ET in PESP. Thus, it is possible to determine left ventricular residual function (the postextrasystolic change in the global EF) using the postextrasystolic change in PEP/ET in patients with coronary artery disease and dilated cardiomyopathy.

Effects of dietary methionine, cystine and potassium sulfate on serum cholesterol and urinary ascorbic acid in rats fed PCB

Liver weight, liver and urinary ascorbic acid levels and serum cholesterol concentration were higher in rats fed polychlorinated biphenyls (PCB) than in controls. The influences of methionine, cystine and potassium sulfate on these metabolic responses were studied. Methionine or equivalent moles of cystine or potassium sulfate were added to a basal diet containing 10% soy protein isolate. The basal diet contained 0.3% of total sulfur-containing amino acids (S-AAs). When methionine was added to the basal diet, maximum gain in body weight was obtained with 0.5% of dietary S-AAs, while the highest values in serum cholesterol and urinary ascorbic acid were obtained with 0.8% of dietary S-AAs in rats fed PCB. Dietary addition of cystine had little effect on body weight gain. Nevertheless, in rat fed PCB, urinary ascorbic acid and serum cholesterol were significantly higher in rats fed the cystine-supplemented diet than in those fed the unsupplemented diet. Addition of potassium sulfate had no effect on body weight gain, urinary ascorbic acid or serum cholesterol. These results suggest that more S-AAs are required for the highest metabolic response to PCB than for maximum growth, and the higher requirement for S-AAs cannot be replaced by inorganic sulfate.

A successful electrical ablation of recurrent sustained ventricular tachycardia in a postoperative case of tetralogy of Fallot

A 26 year old female patient developed recurrent sustained ventricular tachycardia (VT) after undergoing heart surgery for the third time for chronic pulmonary regurgitation following repair of tetralogy of Fallot. At the last surgery, ventriculotomy was again performed in the outflow tract of the right ventricle. At that time, scar formation and thinning of the cardiac wall were obvious. The surgical result was excellent. Three months later, she lost consciousness. ECG showed VT which was refractory to tolerated doses of antiarrhythmic drugs. Electrophysiologic study showed fragmented activity in the outflow tract of the right ventricle during VT which could be induced and terminated by programmed electrical stimulations. DC energy delivery of 200 Joules to catheter electrodes which recorded local activity 20 msec prior to the onset of the QRS of VT was successful in preventing VT. VT could not be induced by extensive programmed stimulation 1 month later.

Late sustained ventricular tachycardia after complete repair of tetralogy of Fallot--a case report

A female patient had recurrent sustained ventricular tachycardia (VT) as a late sequela after complete repair of tetralogy of Fallot, and the clinically documented VT could be induced and terminated in a reproducible manner by programmed stimulation. VT was accompanied by fragmented electrical activities when the electrode was positioned at the outflow tract of the right ventricle where myotomy was added on the previous scar. The electrophysiological study revealed that the mechanism of VT was re-entry and that the focus of VT was located at the right ventricular outflow tract.

[Nonsurgical treatment of renovascular hypertension by percutaneous transluminal angioplasty]

A case of renovascular hypertension treated with percutaneous transluminal angioplasty is reported. Our patient was a 22-year-old housewife with 90 per cent stenosis of the right renal artery due to fibromuscular dysplasia. The renal artery was dilatated by percutaneous transluminal angioplasty with a Grützig balloon catheter to 25 per cent stenosis. Five hours after the procedure, blood pressure decreased from 180/114 mmHg to 130/95 mmHg; one day after, plasma renin activity fell from 4.7 ng/ml/hr to 1.7 ng/ml/hr. The patient was rehospitalized six months after percutaneous transluminal angioplasty to examine restenosis of the dilatated renal artery. Although her blood pressure remained normotensive and plasma renin activity was normal, replasty was performed since selective renal arteriography revealed 50 per cent stenosis.