Mechanisms of limited maximum coronary flow in severe single-vessel coronary artery disease in humans due to vertical steal

We evaluated the usefulness of a decrease in the average peak velocity from 4 to 10 minutes after infusion of dipyridamole for detecting myocardial ischemia in 50 patients, including patients with a prior myocardial infarction. The decrease in the average peak velocity from 4 to 10 minutes associated with vertical steal and combined with a coronary flow reserve of < 1.6 had a high predictive value for myocardial ischemia in patients with or without prior myocardial infarction.

A new predictor of restenosis after successful percutaneous transluminal coronary angioplasty in patients with multivessel coronary artery disease

With the goal of improving prediction of restenosis after percutaneous transluminal coronary angioplasty (PTCA) for multivessel coronary artery disease (CAD), we evaluated the usefulness of serial exercise treadmill tests. We previously reported that an increase in the deltaST/delta heart rate (HR) index at follow-up over the value obtained several days after PTCA was useful for detecting restenosis following PTCA for 1-vessel CAD. In that report, comparison of the deltaST/deltaHR index was made based on measurements from the lead disclosing the greatest ST displacement before PTCA. This method was not applicable to patients with multivessel CAD. Seventy-eight patients with multivessel CAD before and several days after PTCA and just before follow-up performed exercise treadmill tests. Simple HR-adjusted indexes of ST-segment depression during exercise (deltaST/deltaHR index) and the sum of the deltaST/deltaHR index in leads II, III, aVF, V4, V5, and V6 (sigma deltaST/deltaHR index) were determined. We compared the predictive power of an increase in sigma deltaST/deltaHR index at follow-up with that of a positive exercise treadmill test and a positive thallium scintigram for restenosis. At follow-up, 37 of the 78 patients showed restenosis. The sigma deltaST/deltaHR index had increased in 30 of these 37 patients (81%), and in 12 of the 41 patients (29%) without restenosis. An increase in sigma deltaST/deltaHR index had a significantly higher sensitivity than the other methods and a significantly higher specificity than a positive exercise treadmill test.

A case of dyshormonogenetic goiter complicated with growth hormone deficiency

A 17-year-old male patient with dyshormonogenetic goiter complicated with follicular adenoma and growth hormone deficiency is described. He had short stature (-2.3 SD), diffuse goiter and a particularly large nodule in the right lobe of the thyroid gland. The endocrinological studies revealed slight hypothyroidism. He underwent surgical removal of the tumor, diagnosed histopathologically as follicular adenoma, embryonal type; and the diffuse goiter was diagnosed as dyshormonogenetic goiter. It was speculated that long-term hypersecretion of thyroid stimulating hormone (TSH) caused adenoma in the thyroid gland. Although the goiter disappeared after oral thyroxine replacement therapy, his height gain remained poor. Then, he was diagnosed partial growth hormone deficiency, and growth hormone therapy improved his height gain. It has been reported that a high percentage of patients with congenital hypothyroidism have additional anomalies. This is, however, the first reported case of dyshormonogenetic goiter complicated with growth hormone deficiency.

Increase in the delta ST/delta heart rate (HR) index: a new predictor of restenosis after successful percutaneous transluminal coronary angioplasty

With the goal of improving the prediction of restenosis after percutaneous transluminal coronary angioplasty (PTCA), we evaluated the usefulness of the delta ST/delta heart rate (HR) index derived from serial exercise treadmill tests. Exercise treadmill tests were performed by 125 patients with single-vessel coronary artery disease before and several days after PTCA, and just before follow-up angiography 3 to 12 months later. Simple HR-adjusted indexes of ST-segment depression during exercise (delta ST/delta HR index) were derived. We compared the usefulness of the increase in delta ST/delta HR index at follow-up over the value obtained several days after PTCA for prediction of restenosis with that of a positive exercise treadmill test and a positive thallium scintigram at follow-up. At follow-up, 47 of the 125 patients showed restenosis. The delta ST/delta HR index increased in 43 of 47 patients in the restenosis group and in 18 of 78 patients without restenosis (p < 0.0001). Separate analysis of each criterion revealed the following respective values for sensitivity, specificity, and positive and negative predictive values for prediction of restenosis; increased delta ST/delta HR index of follow-up: 91%, 77%, 70%, and 94%; positive exercise treadmill test: 83%, 65%, 59%, and 86%; and positive thallium scintigram: 79%, 78%, 69%, and 86%. The increased delta ST/delta HR index had a significantly (p < 0.05) higher sensitivity than the positive thallium scintigram and a significantly (p < 0.01) higher specificity than the positive exercise treadmill test. An increased delta ST/delta HR index at follow-up identifies subgroups of patients who are at high risk for restenosis after PTCA.

High serum concentration of lipoprotein(a) is a risk factor for restenosis after percutaneous transluminal coronary angioplasty in Japanese patients with single-vessel disease

To determine the relation between the concentration of lipoprotein(a) [Lp(a)] and restenosis after percutaneous transluminal coronary angioplasty (PTCA) in Japan, we studied 80 consecutive patients with single-vessel disease who successfully underwent PTCA. All were evaluated by follow-up angiography a mean of 6.9 months after PTCA and were divided into the restenosis (30 patients) and the non-restenosis (50 patients) groups. The serum Lp(a) concentration of 29 +/- 17 mg/dl in the restenosis group was significantly higher than that of 17 +/- 14 mg/dl in the nonrestenosis group (p < 0.01). Multiple logistic regression analysis for risk factors revealed a significant correlation between restenosis and Lp(a) (p < 0.003). The serum Lp(a) concentration was positively correlated with the coronary artery percent stenosis at the time of follow-up angiography (r = 0.32, p < 0.01). High serum concentration of Lp(a) is therefore a risk factor for restenosis after PTCA in Japan.

Right ventricular stiffness measured by a new method without volume estimation in coronary artery disease

This study was designed to measure the right ventricular (RV) stiffness (delta P/ delta V) with a new method without estimating the RV volume itself. RV stiffness has rarely been measured due to the difficulty in estimating the RV volume. Without measuring RV volume itself, stiffness can be determined by measuring its volume change (delta V). Tricuspid filling flow volume, which is the diastolic RV delta V, is measurable by using Doppler echocardiography. Thus, RV stiffness may possibly be obtained from Doppler echocardiography combined with high-fidelity RV pressure. Subjects consisted of 8 controls, 8 patients with angina pectoris, 8 with anterior, 8 with posterior, and 8 with inferior prior myocardial infarction. Tricuspid annular dimension was measured by 2-dimensional echocardiography and the tricuspid annular area was calculated. Velocity-time integral of the tricuspid filling flow during the late diastole was measured by pulsed Doppler echocardiography. Then, the late diastolic RV delta V was obtained as the product of the tricuspid annular area and the integral. The late diastolic RV pressure rise (delta P) was also measured with a micromanometer catheter. The RV elastic chamber stiffness constant ([delta P/ delta V]/P) was obtained by dividing simple stiffness by the mean RV pressure during late diastole. The RV elastic chamber stiffness constant did not significantly differ among controls, patients with angina pectoris, and those with anterior and posterior myocardial infarction (0.0054 +/- 0.0009 vs 0.0057 +/- 0.0018 vs 0.0064 +/- 0.002 vs 0.0052 +/- 0.0019 ml-1). However, it was significantly increased in patients with inferior myocardial infarction (0.010 +/- 0.004 ml-1, p < 0.01 or 0.05) compared with those in the other 4 groups. These results suggest (1) that RV stiffness can be measured with a new method without RV volume estimation, and (2) that this new method is useful in evaluating RV diastolic pathophysiology in patients with coronary artery disease.

Increased heparin-releasable platelet factor 4 and D dimer in patients one month after the onset of acute myocardial infarction: persistent activation of platelets and the coagulation/fibrinolytic system

To evaluate the activity of platelets and the coagulation/fibrinolytic system 1 month after the onset of acute myocardial infarction, we measured the plasma levels of molecular markers, i.e. beta-thromboglobulin, platelet factor 4, thrombin-antithrombin III complex and D dimer, in 16 patients with acute myocardial infarction and in 11 normal subjects. Blood was drawn through a catheter placed in the pulmonary artery before heparin injection. The heparin-releasable platelet factor 4 was calculated by subtracting the level before the injection of 5000 U of heparin, from the level 5 min after injection. The plasma beta-thromboglobulin, thrombin-antithrombin III complex and the D dimer levels in the acute phase of myocardial infarction were 134.9 +/- 121.2, 11.2 +/- 7.1 and 164.4 +/- 115.3 ng/ml, respectively. These values were significantly higher than those in the normal subjects. The plasma levels of beta-thromboglobulin and thrombin-antithrombin III complex, 1 month after the onset (36.6 +/- 16.4 and 4.6 +/- 2.3 ng/ml, respectively) were not significantly different from those of the normal subjects. In contrast, D dimer and heparin-releasable platelet factor 4 were 216.9 +/- 176.9 and 80.5 +/- 29.3 ng/ml, respectively, and significantly higher than in the normal subjects. These findings suggest a latent but persistent activation of the platelets and the coagulation/fibrinolytic system 1 month after the onset of acute myocardial infarction.

Rapid diagnosis of coronary reperfusion by measurement of myoglobin level every 15 min in acute myocardial infarction

OBJECTIVES

The purpose of this study was to examine whether coronary reperfusion can be diagnosed rapidly and accurately by myoglobin measurements.

BACKGROUND

When intravenous thrombolysis is used for acute myocardial infarction, it is important to determine coronary reperfusion rapidly and noninvasively so that further treatment can be initiated.

METHODS

We determined myoglobin, creatine kinase (CK) and creatine kinase, MB fraction (CK-MB) isoenzyme levels in 63 patients with acute myocardial infarction with total occlusion of the infarct-related artery that was confirmed by coronary angiography. Myoglobin was measured by turbidimetric latex agglutination, which has an assay time of 10 min. We measured myoglobin, CK and CK-MB every 15 min in 45 patients with and 18 patients without reperfusion. The condition of the infarct-related artery was confirmed every 5 to 8 min by coronary angiography.

RESULTS

The rate of increase in myoglobin, CK, and CK-MB at 15, 30, 45 and 60 min after treatment and reperfusion was significantly higher in the reperfused than in the nonreperfused group. In the reperfused group, the rate of increase in myoglobin was significantly higher than the corresponding rate of increase in CK and CK-MB at 15, 30 and 45 min after reperfusion. When reperfusion was evaluated on the basis of a cutoff level (myoglobin > or = 2.0, CK > or = 1.8, CK-MB > or = 1.5), the predictive accuracy of myoglobin (95%) was significantly higher than that of CK (68%) and CK-MB (73%) at 15 min after reperfusion.

CONCLUSIONS

Coronary reperfusion can be rapidly and accurately detected by measurement of the plasma myoglobin every 15 min.

Calcitonin release from medullary thyroid carcinoma by thyrotropin-releasing hormone: comparison with calcium injection

The effects of thyrotropin-releasing hormone on the release of calcitonin were investigated in 15 normal subjects and 12 patients with medullary thyroid carcinoma. The present study also compared the effect of TRH stimulation with calcium infusion test on calcitonin release in patients with medullary thyroid carcinoma. In normal subjects, calcitonin increased from a basal value of 7.5 +/- 2.5 pmol/l to a peak value of 9.4 +/- 3.0 pmol/l (p less than 0.01) after iv injection of synthetic TRH (500 micrograms). Basal calcitonin values in patients with medullary thyroid carcinoma were high (1216 +/- 2230 pmol/l, p less than 0.05), and TRH induced a further increase in calcitonin to 1842 +/- 3149 pmol/l in all the patients (p less than 0.05). They had a peak value of 7891 +/- 13,528 pmol/l after the calcium infusion, which was significantly higher than the basal value of 1463 +/- 2630 pmol/l (p less than 0.05). All medullary thyroid carcinoma patients displayed a marked calcitonin increase after TRH and calcium stimulation. Although the increase in serum calcitonin after TRH injection was lower than that after calcium injection (1.6-fold vs 5.4-fold, p less than 0.05), there was no significant difference in mean peak calcitonin value following TRH and calcium injection in patients with medullary thyroid carcinoma. These results indicated that TRH could stimulate calcitonin release from the thyroid C-cells in both normal subjects and patients with medullary thyroid carcinoma.

Isolation of Yersinia enterocolitica serovar O8 from free-living small rodents in Japan

Yersinia species were isolated from 65 of 223 free-living small mammals trapped in 10 regions on Honshu Island in Japan. Of the 65 strains isolated, 1 was Yersinia enterocolitica serovar O3, 8 were Y. enterocolitica O5, 6 were Y. enterocolitica O8, 3 were Y. enterocolitica O9, and 1 was Yersinia pseudotuberculosis 4b. Of the six Y. enterocolitica O8 strains, five were positive for autoagglutination, Ca2+ dependence, and the 45-MDa virulence plasmid and showed high pathogenicity for mice.

Salt sensitivity and central dopaminergic activity in patients with essential hypertension

The pathophysiological role of the central dopaminergic mechanism in human essential hypertension (EHT) is still unknown, so we investigated a possible relationship between the central dopaminergic activity and salt sensitivity to blood pressure in patients with EHT. We divided 22 inpatients with EHT into salt-sensitive (SS, n = 11) and non-salt-sensitive (NSS, n = 11) groups according to an 8% increase of mean blood pressure (MBP) when dietary salt intake was increased from 2 g/day to 20 g/day for two periods of 7 days each. The change of central dopaminergic activity by salt load was evaluated as the percentage change of plasma prolactin (PRL) response to a small dose (25 micrograms) of thyrotropin-releasing hormone (TRH) administered intravenously. The mean percentage change of PRL response by salt load in the SS group was -9.4 +/- 8.5% (mean +/- SEM), which was remarkably lower than the 26.8 +/- 5.5% in the NSS group (P less than .01). There was a significant negative correlation between the percentage change of PRL response and that of MBP by salt load (r = -0.456, P less than .05). These results suggest that a lack of activation of the central dopaminergic system by salt load may contribute in part to a rise in blood pressure in SS patients with EHT.

Localization of aldosterone-producing adenoma: venous sampling in primary aldosteronism

Adrenal venous sampling of blood was performed for nine patients with aldosterone-producing adenoma (APA). Measurement of adrenal venous aldosterone is useful for localization of APA but difficult, because catheterization of the right adrenal vein is not easy, and the blood is diluted by nonadrenal flow. To solve these problems, levels of aldosterone (A; ng/dl) and cortisol (C; micrograms/dl) were measured in samples from the left adrenal vein (LAV) and the inferior vena cava (IVC), and the LAV A/C and (LAV A/C)/(IVC A/C) ratios were calculated. These ratios were also obtained for 16 patients with essential hypertension. The adenoma could be localized in three of the nine cases by the measurement of aldosterone alone, but the use of a LAV A/C ratio greater than 5 x 10(-3) and a (LAV A/C)/(IVA A/C) ratio less than 1.0 as criteria separated the patients into those with a left APA, right APA, or essential hypertension. Consequently, adrenal venous sampling and the calculation of these ratios enables preoperative localization of APA with more accuracy, especially when the tumor is small or the result of CT and adrenal scintigraphy is not consistent.

A survey for Yersinia pseudotuberculosis in migratory birds in coastal Japan

Yersinia pseudotuberculosis was isolated from three specimens of two species of birds, the black-faced bunting (Emberiza spodocephala) and pied wagtail (Motacilla alba), of 528 specimens of birds examined from coastal regions in Japan. The two isolated strains of Y. pseudotuberculosis were identified as serovar 4b and serovar 3. This is the first isolation of Y. pseudotuberculosis from birds in Japan. Yersinia enterocolitica was isolated from three specimens of the pied wagtail, one specimen of the reed bunting (Emberiza schoeniclus) and one specimen of the rustic bunting (Emberiza rustica). Yersinia frederiksenii was isolated from two specimens of the gray-rumped sandpiper (Heteroscelus brevipes). Yersinia intermedia was isolated from one specimen of the pied wagtail.

[Lateralisation of aldosterone-producing adenoma in primary aldosteronism]

Four lateralizing methods were carried out in 14 patients with primary aldosteronism (PA): ultrasonography, CT scan, adrenal scintiscan and determination of adrenal venous aldosterone levels. In all cases, unilateral aldosterone-producing adenomas were verified by surgery. Of four lateralizing methods, determination of adrenal venous aldosterone, in spite of high diagnostic value, has two big problems: difficulty in selective catheterization of right adrenal vein and dilution of adrenal vein efflux from non-adrenal sources. To solve these problems, cortisol (C, micrograms/dl) levels along with aldosterone (A, ng/dl) were determined in samples from the left adrenal vein (LAV) and the inferior vena cava (IVC) in 8 patients with PA, and the (LAV A/C)/(IVC A/C) ratio was calculated. That ratio was also obtained in 7 patients with other types of hypertension for comparison. Accuracy of lateralisation by ultrasonography, CT scan and adrenal scintiscan was 23%, 64% and 69% respectively, in the first studies. Those rates changed to 23%, 93% and 85% when the second studies were performed. Venous blood was obtained from both adrenal veins in 46% (6/13), while lateralisation of adenoma was also predicted in 46% (6/13) by the measurement of aldosterone concentrations alone. On the other hand, (LAV A/C)/(IVC A/C) ratios were 3.54-6.98 in the cases of left APA, 0.15-0.98 in those of right APA and 1.10-2.86 in cases of other types of hypertension. There was no overlap of ratios among the three groups, resulting in correct prediction of lateralisation in all cases (8/8) of APA.(ABSTRACT TRUNCATED AT 250 WORDS)

[Salt sensitivity and central dopaminergic activity in patients with essential hypertension]

The pathophysiological role of the central dopaminergic mechanism in human essential hypertension (EH) is still unknown. We studied on the relationship between the dopaminergic activity and the salt-sensitivity. Twenty three hospitalized patients with EH were divided into the salt-sensitive group (SS, n = 12) or non salt-sensitive group (NSS, n = 11) by their responses whether they caused more than 8% increase in mean blood pressure (MBP) when the dietary salt was increased from 2g/day to 20g/day for 7 days of each. The change of central dopaminergic activity by the salt load was evaluated by the decrement of plasma prolactin (PRL) response to small dosage (25 micrograms) of thyrotropin releasing hormone. The mean percent change of PRL response by the salt load in the SS group was -6.5 +/- 8.3% (mean +/- SEM), which was significantly lower than 26.8 +/- 5.5% in the NSS group (p less than 0.01). There was a significant negative correlation between the percent changes of PRL response and the percent changes of MBP by the salt load (r = -0.448, p less than 0.05). These results suggested that the rise in blood pressure by salt load in SS patients with EH might be due to a reduced activity of the central dopaminergic mechanism.

The effect of iopanoic acid on thyrotropin secretion in patients with cirrhosis of the liver

Ten patients with liver cirrhosis and six normal subjects were studied to evaluate the effect of iopanoic acid (IA) on thyrotropin secretion. A thyrotropin-releasing-hormone (TRH) test was performed before and 5 days after IA administration (single oral dose of 3 g). After IA administration, a significant increase in TSH response to TRH was observed in normal subjects. In cirrhotics, however, it did not significantly increase after IA administration. The serum T3 and T3/TBG ratio were significantly decreased and the serum T4 and T4/TBG ratio were increased after IA administration in normal subjects and cirrhotics. There was no significant difference in the % decrease in serum T3, % increase in serum T4 or other thyroid hormone parameters including TSH in IA induced TSH responders (R) and non-responders (NR). However, r-T3 before and after IA in R was higher than those in NR. The values for hepatic function tests such as serum albumin, prothrombin time, 45 minutes retention rate of bromsulphalein (BSP 45 min) and the cholinesterase (ChE) level in R were not different from those of NR. These results suggested that in cirrhotics, abnormal regulation of the hypothalamo-pituitary system might exist.

[Two-dimensional contrast echocardiographic assessment of the time course of regional ischemic myocardial function]

The time course of percent fractional area change (%FAC) of the ischemic left ventricular wall as identified by myocardial contrast echocardiography was assessed. Two-dimensional echocardiograms of the left ventricular short axis at the level of the chordae tendineae were recorded in 16 anesthetized open-chest dogs. Myocardial ischemia was produced by occluding the left circumflex coronary artery (LCX) for 30 min, and identified by myocardial contrast echocardiography using aortic root contrast injection. The left ventricular wall in the short-axis view was divided into eight segments. The experiments were completed in nine dogs. The %FAC of the segment which includes the center of the ischemic area was normal before LCX occlusion (35 +/- 6%: mean +/- S.D.), markedly decreased during 30 min of LCX occlusion (-3 +/- 4%) and gradually recovered after coronary reperfusion. However, it was significantly decreased 150 min after reperfusion (8 +/- 9%) (p less than 0.001) compared to that before LCX occlusion. The %FAC of the segment which includes the center of the non-ischemic area was not significantly changed throughout the experiment. In conclusion, 1) the time course of regional ischemic myocardial function could be assessed by the analysis of the %FAC of the ischemic area determined by myocardial contrast echocardiography, 2) the %FAC is significantly decreased 150 min after coronary reperfusion following 30 min occlusion compared to that before coronary occlusion.

Assay of a circulating sodium pump inhibitor in patients with essential hypertension and normotensive subjects

The plasma levels of a sodium pump inhibitor (Na+ PI) were measured by a modified method of Hamlyn et al, using dog kidney Na+, K+-ATPase. When the level of Na+ PI was expressed as the % inhibition of the enzyme and compared with that of a control solution, it was found to be 9.0 +/- 0.7% in 43 untreated patients with essential hypertension. This was significantly higher than 5.0 +/- 0.4% for 56 normotensive subjects (p less than 0.01). Male patients with essential hypertension showed the highest mean value of 10.5 +/- 1.1%, disclosing an apparent sex difference in the patient group (p less than 0.01). Only in female patients was there a significant positive correlation between the inhibitor's level and the mean blood pressure (r = 0.649, p less than 0.01). These results provided additional evidence for increased Na+ PI in the plasma of patients with essential hypertension, which might bear an important role in the pathogenesis of the disease.

Masked thyroid dysfunction among elderly patients with atrial fibrillation

Seventy-five elderly patients with atrial fibrillation (41 males and 34 females with a mean age of 75.6 years) were studied to evaluate the incidence of masked thyroid dysfunction. A thyrotropin (TSH)-releasing-hormone (TRH) test (intravenous injection of 250 micrograms of synthetic TRH) was performed in the patients and 30 age matched controls without atrial fibrillation. In the controls, no abnormal TRH stimulated TSH response was observed. In the patients with atrial fibrillation, no response of TSH to TRH (hyperthyroidism) was found in 5 cases (6.6%), while hyperresponse of TSH to TRH (hypothyroidism) was found in 6 cases (8.0%). Thyroid dysfunction (hyper or hypothyroidism) was more frequently observed in the patients than in the controls (p less than 0.05). Two of 5 hyperthyroid patients had normal thyroid hormone levels. All patients with hyperthyroidism were treated with antithyroid drugs or 131I. Unfortunately, atrial fibrillation persisted in all but 1 case. It is concluded that the TRH test is a useful screening test for detecting those patients with abnormal thyroid function among elderly patients with atrial fibrillation, and that hypothyroidism should be considered as a cause of atrial fibrillation in the elderly.

Clinical evaluation of the captopril screening test for primary aldosteronism

In order to investigate the validity of angiotensin converting enzyme inhibition with captopril as a screening test for primary aldosteronism (PA), 50 mg of captopril were administered orally to 7 patients with PA, 17 with essential hypertension (EH), 5 with renovascular hypertension (RVH), 2 with renoparenchymal hypertension (RH) and 8 normal volunteers. The plasma aldosterone concentration (PAC) was suppressed to less than 15 ng/dl in all of the EH, RVH and RH patients and normal subjects 90 min after administration of captopril, but not suppressed in 6 of 7 patients with PA. In addition, the plasma renin activity (PRA) was increased to greater than 1 ng/ml/h in 10 of 17 patients with EH and in all with RVH, RH and the normal controls, but to less than that in 6 of 7 PA and the remaining EH patients. The PAC to PRA ratio after captopril was greater than 20 in all patients with PA, while it remained below 20 in EH, RVH and RH patients and normal controls. From these results, we conclude that the PAC to PRA ratio in the captopril administration test is a simple and useful tool to detect PA in hypertensive patients. In addition, the test has a great advantage in that it can be safely applied to outpatients with relatively severe hypertension.

Vasodilatory and diuretic actions of alpha-human atrial natriuretic polypeptide (alpha-hANP)

Vascular and diuretic actions of synthetic alpha-human atrial natriuretic polypeptide (alpha-hANP) were studied using anesthetized dogs and isolated canine arterial strip preparations. alpha-hANP, when given intra-arterially or intravenously, dilated the renal artery more selectively than the vertebral, femoral, common carotid and coronary arteries. alpha-hANP selectively relaxed the high K+-contracted renal artery strip as compared with the basilar, coronary and femoral arterial strips. Intravenous alpha-hANP also increased urine volume and urinary excretion of electrolytes at doses, at which it increased renal blood flow and lowered systemic blood pressure without changing heart rate. It is concluded that alpha-hANP has a vasodilatory property relatively specific for the renal artery, and that it possesses diuretic, natriuretic, kaliuretic, magnesiuretic, calciuretic and chloruretic activities concomitantly with a definite hypotensive activity.

Thyroid antibodies in healthy blood donors

The frequency of thyroid antibodies was investigated in 1314 healthy blood donors. Twenty-three of 870 males (2.6%) were positive for thyroglobulin antibody (TA), 34 (3.9%) for thyroid microsomal antibody (MA) and 19 (2.2%) for both TA and MA. Thirty-four of 484 females (6.2%) were positive for TA, 46 (9.5%) for MA and 29 (6.0%) for both TA and MA. Eighty-six of 1314 blood donors were positive for TA and/or MA. There was no difference in liver function tests between AAT and controls. In females, the incidence of thyroid antibodies tended to increase with age. However, the subjects aged under 19 showed another peak of incidence of thyroid antibodies. The values of total T4, T3 and free T4 were not different between 86 subjects with positive thyroid antibodies (asymptomatic autoimmune thyroiditis, AAT) and 86 sex- and age-matched controls without thyroid antibodies, whereas serum TSH of AAT was significantly higher than that of controls. Nine of 86 (10.5%) subjects with AAT had apparently increased basal TSH level.