Morphometry of the small pulmonary arteries in man. From a resin cast of a normal pulmonary arterial tree, the diameter, length, and number of branches in each order were determined for arteries from 25 to 300 micrometer in diameter. Histological sections 120-micrometer thick were cut from a normal human lung in which the pulmonary artery had been injected with a mixture of ink and gelatin. Similar measurements were made on arteries from 10 to 70 micrometer in diameter, and the mode of origin of the capillaries was studied. The data thus obtained were found to correspond reasonably well to values previously estimated by extrapolation from data for arteries of 100 micrometer or more in diameter. The branching rules apply down to arteries of about 10-15 micrometer in diameter, the estimated number of which is 73 million. Distal to these vessels, capillaries arise either directly from small arteries or indirectly via precapillaries which are given off in great numbers and diverse patterns from the small arteries


Age-related changes in the concentration of plasma cholesterol and triglycerides in two groups of rats with inherited widely different levels of spontaneous physical activity. The plasma concentration of cholesterol and triglycerides was determined in two groups of rats with inherited widely different levels of spontaneous physical activity. Active as well as passive rats of each sex were divided into two subgroups, one with free access to wheel running activity (exercising group), and another for which admittance to the drum was closed (nonexercising group). Plasma concentrations of cholesterol and triglycerides were followed from the age of 3-8 months in females and 3 months to 1 year in males. A pronounced increase with age in the plasma concentration of these lipids was observed in the active male rats. In the passive male rats and in all females, there were no major changes in plasma levels of cholesterol and triglycerides. Corresponding groups of exercising and nonexercising rats had similar plasma levels of these components. The data for male rats show a positive association between the inherited tendency to perform spontaneously a high level of physical activity and an age-related increase in plasma lipids. However, running activity per se does not seem to have any influence on the level of plasma cholesterol and triglycerides in these rats.


The effect of an increase in inotropic state and end-diastolic volume on the pumping ability of the feline left heart. In isolated ejecting cat hearts, the pumping ability of the left heart was described quantitatively by the relationship between mean left ventricular pressure and mean left ventricular output. This relationship was determined by making the heart eject against a series of different loads on a beat-to-beat basis. Left ventricular mean pressure-mean output relationships of control and potentiated beats (at the same end-diastolic pressure) have a common intercept on the output axis but diverge toward the pressure axis. When the mean pressure values of the potentiated beats in a given experiment are multiplied by a single factor, superposition of the two relationships is obtained. A change in left ventricular end-diastolic pressure caused a more parallel shift of the left ventricular mean pressure-mean output relationship. Here, superposition could be obtained by using one multiplication factor for the mean pressure data and one for the mean output data of the relationship found after the change in end-diastolic pressure. We concluded that, using the left ventricular mean pressure-mean output relationship, changes in cardiac pumping ability caused by given changes in inotropic state and ventricular end-diastolic volume can be quantified by one or two multiplication factors, respectively.


Nuclear proteins in the heart of the cardiomyopathic Syrian hamster. Phosphorylation of phenol-soluble nonhistone proteins. We examined incorporation of 32P into phenol-soluble nonhistone nuclear acidic proteins (NHNP) obtained from myolytic, hypertrophic, and failing phases of hamster cardiomyopathy. NHNP from these dystrophic hamster hearts were phosphorylated much less than their controls, despite a 9-fold increase in uptake of 32P into their nuclei. After fractionation of NHNP by isoelectrofocusing polyacrylamide gel electrophoresis, two major fractions focusing from pH 6.0 to 6.2 and 6.6 to 6.8 were highly phosphorylated in both the control and dystrophic hearts. The latter fraction was much more phosphorylated in the control. Two fractions of NHNP focusing at pH 4.9 and 5.1 were more highly phosphorylated in the dystrophic hearts than in the controls. Autoradiographs obtained from the two-dimensional polyacrylamide slab gel electrophoresis showed that two proteins (pH 4.9 and 5.1; mol wt 25,000 and 60,000, respectively) were highly phosphorylated in the dystrophic heart. There was no detectable phosphorylation of these proteins in the controls. These changes in the phosphorylation of cardiac NHNP may be important in determining the alteration of gene expression in hamster cardiomyopathy.


The influence of the pituitary on arterial intimal proliferation in the rat. The formation of arteriosclerotic fibromusculoelastic intimal thickening following arterial de-endothelialization is well documented. Recent findings, both in vitro and in vivo, suggest that platelets are a major participant in the pathogenesis of this lesion by releasing a mitogen to medial smooth muscle cells (SMC). This mitogen results in SMC migration to and proliferation within the intima. A similar mitogen has been described as originating in brain and pituitary tissue. We now report that, in hypophysectomized rats with normal platelet counts, intimal hyperplasia is markedly delayed; pair-fed intact controls normally develop lesions. It therefore appears that the pituitary gland plays a significant role in the experimental arteriosclerotic response.


Renal function of conscious spontaneously hypertensive rats. Renal clearance studies were performed in conscious 13-week-old spontaneously hypertensive rats (SHR) and normotensive Wistar-Kyoto rats (WKY) before and during volume expansion by intravenous infusion of isotonic saline. Mean arterial pressure and filtration fraction were greater in SHR, whereas fractional and absolute excretion of sodium and water, glomerular filtration rate, and renal plasma flow in SHR and WKY were not statistically different. This was the case during hydropenia and volume expansion. We did not observe as exaggerated natriuresis after intravenous loading when unanesthetized SHR were compared with the response of WKY. These observations suggest that the kidneys of genetically hypertensive rats of the Okamoto-Aoki strain have adapted to an elevated renal perfusion pressure or that hypertension is required to normalize renal function so that excretion is appropriately matched with intake.


Urinary kallikrein in rats bred for their susceptibility and resistance to the hypertensive effect of salt. A new radioimmunoassay for its direct determination. Urinary kallikrein was measured in rats bred to be susceptible (S) or resistant (R) to the hypertensive effect of salt. To determine kallikrein, three different methods were used: (1) a new direct radioimmunoassay (RIA) for the enzymic protein: (2) a method based on the capability of kallikrein, when incubated with kininogen, to generate kinins which were then measured by RIA (kininogenase activity); and (3) a method based on the capability of kallikrein to break the ester bond of p-tosyl-L-arginine methyl ester (HCl (TAMe). A significant correlation ( r = 0.90) was found between the direct RIA and the kininogenase method. It was found that urinary kallikrein was significantly decreased in the S as compared to the R rats by the use of these three methods. Urinary kallikrein in the S rats was much lower when measured by the kininogenase method than by direct RIA or esterolytic assay. This difference could be due to excretion of pre-kallikrein and/or kallikrein bound to an inhibitor (inactive kallikrein). It is suggested that the decrease of urinary kallikrein excretion (active and inactive) in the S rats could be a consequence of a genetic defect that may affect the development of hypertension perhaps through the alteration of sodium and water excretion by the kidney.


The effects of short-term venous congestion on forearm venous volume and reactive hyperemia blood flow in human subjects. Congestive heart failure is associated with a reduction in limb venous volume at an effective venous pressure of 30 mm Hg (VV[30]). Further, an attenuated arteriolar dilation in response to a metabolic stimulus has been demonstrated. It was the purpose of this study to determine to what extent the chronic elevation in venous pressure seen in heart failure might explain these abnormalities of the limb circulation. Ten normal human volunteers were subjected to venous congestion of one arm for three hours at 70 mm Hg. A mercury-in-rubber strain gauge plethysmograph was used to measure forearm VV [30] and forearm blood flow at rest after release of five minutes of arterial occlusion (the reactive hyperemia response). Congestion reduced VV [30] 22%, resting forearm blood flow 49% and peak reactive hyperemia blood flow 25%. Thus, chronic venous congestion per se may significantly reduce limb venous volume as well as resting and reactive hyperemia blood flow.


Anticoagulant therapy and central nervous system complications in patients with prosthetic valve endocarditis. Among 52 cases of prosthetic valve endocarditis, adequate anticoagulant therapy was administered in 38 and discontinued or given in subtherapeutic dosage in 14. Our data suggest that anticoagulant therapy does not appreciably increase morbidity or mortality in patients with prosthetic valve endocarditis. On the contrary, in our patients the incidence of major clinical CNS (central nervous system) complications was increased and the mortality was higher if anticoagulant therapy was discontinued. CNS complications occurred in 10 of the 14 patients without adequate anticoagulant therapy and in three of the 38 with adequate anticoagulant therapy. Mortality was 57% among those treated without adequate anticoagulation and 47% among those with adequate anticoagulation. At autopsy, CNS complications were thought to be the primary cause of five of the eight deaths in cases without adequate anticoagulation.


Long-term tocainide therapy for ventricular arrhythmias. Long-term tocainide therapy has been evaluated in 17 patients with ventricular arrhythmias. Ventricular tachycardia and/or fibrillation was recurrent and sustained in nine patients, and symptomatic but unsustained in three others. Five patients had frequent but only mildly symptomatic ventricular irritability. In all patients, arrhythmias could not be managed with quinidine, procainamide or propranolol. Tocainide doses ranged from 300 to 700 mg every 8 hours (mean steady-state plasma concentrations ranged from 5.75 to 12.18 microgram/ml). Tocainide therapy was unsuccessful in eight patients; three died during therapy and five had no antiarrhythmic response. The data suggest that evaluation of long-term drug efficacy, using the criterion of reduction of asymptomatic arrhythmias, is best documented by multiple sequential ambulatory electrocardiographic recordings, both on and off the drug. Tocainide controlled arrhythmias in nine patients (53%), with criteria of success being continued reduction of ectopic beats and/or control of symptomatic recurrences. Seven patients remain on therapy. Side effects generally have been minor and well-tolerated.


Dissecting aortic aneurysm associated with congenital bicuspid aortic valve. Among 119 cases of fatal dissecting aneurysm of the aorta, exclusive of those iatrogenically caused or associated with arachnodactyly or aortic stenosis, there were observed 11 cases of congenital bicuspid aortic valve (9%). The ages ranged from 17 to 69 years, five of the patients being 29 years old or younger. Among the latter, three had coarctation of the aorta and one had Turner's syndrome without coarctation. In one of the older patients, aortic insufficiency was present. Hypertension was either established or inferred from cardiac weight in 73% of the cases. In each case, cystic medial necrosis of the aorta was present. Prolapse of valves other than the aortic was observed in 45% of the cases with bicuspid aortic valve. Compared to an estimated incidence of bicuspid aortic valve of about 1 to 2% in the population, the high incidence among subjects with dissecting aneurysm suggests a causative relationship between bicuspid aortic valve and aortic dissecting aneurysm.


Anomalous origin of left coronary artery from the pulmonary artery with ventricular septal defect. Only two cases have been reported previously of the association of ventricular septal defect (VSD) with anomalous origin of the left coronary artery (ALCA) arising from the pulmonary artery. The purpose of this paper is to present two additional cases, to describe the pathophysiology, and to emphasize how the clinical course of this combination of defects differs from that of isolated ALCA. Patients with both of these anomalies present in infancy with manifestations only of a large left-right ventricular shunt and pulmonary hypertension. Initially the ALCA is well perfused from the high pressure in the pulmonary artery. In these instances in which the pulmonary artery pressure subsequently decreased because of spontaneous reduction in size of the VSD, the left coronary arterial system became less well perfused. Because of this decreased perfusion in association with the left ventricular myocardial stress initially caused by volume overload, myocardial ischemia and ultimately infarction occurred. Early identification and repair of the anatomic abnormality could prevent irreversible myocardial damage.


The anatomical substrates of wolff-parkinson-white syndrome. A clinicopathologic correlation in seven patients. Clinicopathological correlations were made on the hearts from seven patients known to have exhibited electrocardiographic evidence of the Wolff-Parkinson-White syndrome. In each case, clinical and pathological investigations were conducted independently, neither group of investigators having knowledge of the other's results. In all seven hearts, the entire atrioventricular junctions were serially sectioned. Accessory atrioventricular connections were predicted in all seven cases following electrocardiographic investigation. Connections were identified histopathologically in four hearts in the predicted site. In another case two connections were identified, one being considered responsible for the pre-excitation. In the sixth case a right lateral connection was anticipated, but only accessory nodo-ventricular fibers were identified following histopathologic studies. In the final case, a posterior septal connection was predicted but the entire septum had fibrosed following previous operation. These findings are discussed in the light of the investigative techniques used, the theories of pre-excitation and the embryogenetic mechanisms producing accessory atrioventricular connections.


Junctional pacemakers in man. Response to overdrive suppression with and without parasympathetic blockade. This study analyzes the response to overdrive suppression of junctional pacemakers (JP) and correlates it with symptoms in 21 patients. Junctional rhythm (JR) was seen in 5 patients with intact A-V conduction, and in 16 with complete heart block, the JPs were located proximal to or within the His bundle (BH). Junctional recovery time (JRT) was measured following atrial or ventricular pacing during control and after atropine (2-2.5 mg). Control cycle length of the JR ranged from 835-2100 msec (mean 1402) and the corrected JRT (CJRT) ranged from 75 to greater than or equal to 7510 msec (mean 2966). Following atropine, the cycle length ranged from 660 to 2000 msec (mean 1115) and the CJRT ranged from 90 to greater than 6000 msec (mean 2050). All symptomatic patients were treated with permanent ventricular demand pacemakers and followed clinically from 6-72 months (mean = 35). Symptomatic patients could not be differentiated from asymptomatic patients on the basis of control heart rates, chronotropic response to atropine, and/or the site of origin of the JP as determined with BH recordings. However, presence or absence of symptoms of syncope and dizziness were well correlated with a CJRT greater than or less than 200 msec, respectively, either following atropine or during control. The determination of CJRT both before and after parasympathetic blockade provides a simpler and more reliable method for the therapeutic evaluation of patients.


Evaluation of R wave amplitude changes versus ST-segment depression in stress testing. Exercise ECGs and coronary angiograms were reviewed in 266 patients (81 normals and 185 with significant coronary artery disease). Thirty-three false positive and 96 false negative ST responses to stress testing were purposely chosen to determine if the R wave could reduce the number of false ST responses. R wave amplitude changes were measured in the control and in the immediate postexercise period. An increase or no change in R wave was taken as evidence of an abnormal response, while a decrease  in the R wave was a normal response. The sensitivity by ST segment was 48% and the specificity was 59%. These values were low because of the large number of false positive and negative ST responses in the study. It was our purpose to determine if these lowered values could be significantly improved by the R wave. Using R wave criteria, the sensitivity was 63% (P is less than 0.01) while the specificity was 79% (P is less than 0.01). The sensitivity and specificity of stress testing can be significantly improved using R wave changes.


Cardiovascular complications during exercise training of cardiac patients. The occurrence of major cardiovascular complications during exercise training of cardiac patients in 30 cardiac rehabilitation programs in North America was determined by questionnaire. These programs conducted medically supervised cardiac exercise classes in 103 locations and reported information on 13,570 participants who accumulated a total of 1,629,634 patient hours of supervised exercise. Cardiovascular complications were reported as nonfatal or fatal and included cardiac arrest, myocardial infarction and other. A total of 50 cardiac arrests were observed during exercise, 42 of which were successfully resuscitated while eight were fatal. Seven myocardial infarctions were reported; five were nonfatal and two were fatal. Four other fatalities were reported due to acute cardiopulmonary disorders. The average complication rate for all programs was one nonfatal and one fatal event every 34,673 and 116,402 patient hours of participation, respectively. Complication rates are lower in programs which continuously monitor the electrocardiogram during exercise and are lower when only the experience since 1970 is evaluated. These data support the recommendation that medically prescribed and supervised exercise can be performed reasonably safely by medically selected cardiac patients.


An ultrasound system for combined cardiac imaging and Doppler blood flow measurement in man. An ultrasound instrument has been developed that combines a real-time cross-sectional imaging system and a spectrum analyzer-based Doppler velocimeter. This combination allows the Doppler sample volume to be superimposed on the cross-sectional image of the heart so that the sample volume can be located accurately. The same 2.2 MHz transducer utilized for cross-sectional imaging is stopped mechanically and quickly switched to transmit and receive the Doppler ultrasound signal. Preliminary experience in 20 young and adult normal subjects indicates that it is possible to place the Doppler sample volume in the proximal main pulmonary artery at a point where the sound beam and blood flow stream are parallel. Measurement of the distance from transducer to the sample volume and the peak blood flow velocities in the main pulmonary artery of normal subjects indicates that these quantities are within the measurement capabilities of the system. The ultimate goal of this device is to make measurements of volume blood flow in man noninvasively.


Transcutaneous doppler jugular venous flow velocity recording. Transcutaneous bidirectional Doppler jugular venous flow velocity patterns were classified and correlated in 82 patients with right heart hemodynamics. The normal forward flow pattern was biphasic with systolic flow (Sf) greater than the diastolic flow (Df). With rare exceptions, flow patterns of Sf = Df, Sf is less than Df and Df alone indicated abnormal right heart hemodynamics. Abnormal flow patterns (Sf = Df and Sf is less than Df) seen in post cardiac surgery states, and in some rare patients with severe mitral regurgitation despite normal right-sided pressures, were probably secondary to postoperative change in right atrial compliance in the former and to a Bernheim effect in the latter. The most common cause of retrograde systolic flow in the absence of atrioventricular dissociation was tricuspid regurgitation. Persistent retrograde end-diastolic flow with normal forward flow was associated with high right atrial "a" wave pressures, indicating significant decrease in right ventricular compliance with a vigorous atrial contraction. The study clearly established that the jugular venous flow velocity pattern truly reflected derangements in the right heart hemodynamics, irrespective of the underlying etiology. The applicability to bedside evaluation of the jugular venous pulse and the right heart hemodynamics is emphasized.


The prognostic spectrum of left main stenosis. Three-year survival for 163 consecutive medically treated patients with 50% or greater left main stenosis was 50%. Survival was significantly higher for patients with 50 to 70% left main stenosis (one and three-year survivals of 91% and 66%) than for patients with 70% or greater left main stenosis (one and three-year survivals of 72% and 41%). In fact, left main lesions of less than 70% were not associated with the increased risk usually attributed to patients with left main stenosis. A number of noninvasive and catheterization characteristics were significant predictors of survival for patients with 70% or greater left main stenosis. Noninvasive descriptors defined a low risk subgroup (one and three-year survivals of 97% and 74%) and a high risk subgroup (one- and three-year survivals of 59% and 25%). These observations have important implications both in assessing therapeutic interventions and in managing individual patients.


Exercise-induced reduction in myocardial infarct size after coronary artery occlusion in the rat. Chronic exercise (E) has been thought to be beneficial to the cardiovascular system by increasing energy production and utilization, improving myocardial contractility and increasing myocardial vascularity; whether or not any of these effects are beneficial to ischemic myocardium is uncertain. In this study, rats were forced to swim one hr/day, 5 days/wk for 5 weeks. They were sacrificed and the myocardial capillary bed was perfused with carbon black. Using a calibrated eyepiece grid, histologic sections of heart were examined to determine capillary/fiber ratios (C/F) and myocardial fiber diameter. C/F was increased by 30% in E rats [0.87 +/- 0.06 (mean +/- SE) (N = 4 rats)] when compared with sedentary controls (C) [0.67 +/- 0.04 (N = 4 rats), P is less than 0.05]. This training effect occurred in the absence of hypertrophy since there were no differences in ventricular weight (1.21 +/- 0.04 mg in E rats vs 1.16 +/- 0.03 mg in C rats) or in fiber diameter (13.0 +/- 0.2 mu in E rats vs 13.1 +/- 0.2 mu in C rats) in the two groups. An additional 27 E rats and 25 C rats underwent left coronary artery occlusion and were sacrificed 48 hr later. Myocardial infarct size was measured by planimetry of histologic sections of serial slices of left ventricle (LV). In the 27 E rats, 21.5 +/- 1.9% of the LV was infarcted compared with 31.3 +/- 2.6% in the 25 C rats (P is less than 0.005). Thus, infarct size was reduced by 30% in E rats. In the rat, exercise results in a reduction of myocardial infarct size after coronary artery occlusion which, at least in part, may be related to increased myocardial vascularity.


The bruit of carotid stenosis versus radiated basal heart murmurs. Differentiation by phonoangiography. Phonoangiography, quantitative analysis of arterial bruits, has been shown to provide accurate noninvasive diagnosis of uncomplicated carotid arterial stenosis, but had not been tested where cervical bruits from other sources were present. In this study, 27 carotid bruits in 15 consecutive patients with carotid bruits and basal heart murmurs were analyzed by phonoangiography. Tape recordings were made over the base of the heart and along the course of the carotid arteries in the neck; spectral analysis was performed as previously described. The spectral shape of the basal heart murmurs was recognizable and amplitude decreased with distance from the heart, althouth a secondary, lower amplitude, maximum often occurred over the carotid bifurcation. Intrinsic carotid bruits, by contrast, were always maximal over the bifurcation, and although they radiated both proximally and distally, were not detectable over the chest wall. In quantitative terms, the correct diagnosis as to the presence and extent of carotid stenosis was made in 25 of 27 cases (92%) despite the presence of a radiated murmur. Phonoangiography is capable of accurate differentiation of radiated murmurs from intrinsic carotid bruits and of quantitation of the latter even in the presence of radiated sounds.


Long-term mitral valve replacement in young children. Influence of somatic growth on prosthetic valve adequacy. Long-term clinical and laboratory findings in three children who required mitral valve replacement below age four years are reported. In each instance a second valve replacement was necessary approximately 8 1/2 years after the initial one, following a two and one-half fold increase in body weight. Inadequate mitral valve orifice size was found in each instance, producing a hemodynamic picture equivalent to mitral stenosis: congestive heart failure, pulmonary hypertension and atrial fibrillation. A second valve was placed without mortality in each instance and relieved the mitral valve obstruction. Pulmonary vascular resistance increased postoperatively in two patients and failed to decrease in the third. Pulmonary arterial hypertension and left ventricular hypertrophy persisted as long as 13 to 37 months after the second valve placement in all patients. The consequences of increasing body size and the long-term interposition of a rigid prosthesis in a growing heart introduce additional complications to mitral valve replacement in childhood. Frequent hemodynamic observations and the use of a prosthesis other than the ball-cage variety is recommended for improved management.


The murmur of pulmonic regurgitation in tetralogy of Fallot with absent pulmonic valve. Absent pulmonic valve (APV) in tetralogy of Fallot produces a pulmonic regurgitation murmur (PRM) which is usually late in onset after A2, low pitched, and of crescendo-decrescendo character. We have seen three adult patients with tetralogy of Fallot with APV and have done intracardiac sound and pressure studies in two. The PRM was loudest in the RV outflow tract (RVOT), where the onset was earlier than the murmur recorded on the chest wall. The crescendo portion of the PRM occurred during an abnormally slow decline in the RVOT pressure pulse after the crossover of PA and RVOT pressures. The RVOT pressure reached its minimum 30 msec after the RV body pressure, resulting in a pressure gradient between the two. The PRM peaked 30 msec later in the RV body than in the RVOT. The delayed precordial onset of the PRM after A2 is likely due to failure of transmission of early vibrations through the chest wall. The morphology of the PRM in tetralogy of Fallot with APV may be related to delayed relaxation with altered diastolic compliance of the RVOT which is subjected to a large regurgitant volume from the massively dilated pulmonary arteries.


Right and left ventricular volume characteristics in common atrioventricular canal. Right (RV) and left (LV) ventricular volume characteristics were determined from biplane cineangiography in 29 patients with atrioventricular canal (AVC). The patients were classified into two groups: group I (N = 19), uncomplicated AVC; group II (N = 10), AVC associated with RV obstruction. In group I, LV end-diastolic volume (EDV) [177 +/- 9 (SEM)% of normal] and RVEDV (125 +/- 9%) both were greater than normal (P is less than 0.001 and less than 0.01, respectively). LV ejection fraction (EF) was decreased (0.59 +/- 0.02, P is less than 0.001) but RVEF was normal (0.58 +/- 0.03). LV stroke volume index (SVI) was increased (48 +/- 3 ml/m2, P is less than 0.005), and RVSVI was normal (34 +/- 3 ml/m2). One patient had a markedly small RVEDV (45%). In group II, LVEDV and RVEDV were not different from normal (119 +/- 11% and 97 +/- 15%, respectively). LVEF was depressed (0.52 +/- 0.04, P is less than 0.001) and RVEF was normal (0.55 +/- 0.05). LVSVI was normal (38 +/- 5 ml/m2) and RVSVI was slightly decreased (29 +/- 4 ml/m2, P is less than 0.025). Two patients had a markedly small RVEDV (31%, 55%). EDV correlated with the pulmonary-to-systemic flow ratio (LV, r = 0.71; RV, r = 0.68). The data show that in most patients with AVC, LV and RV are enlarged in the uncomplicated form but not in the form with RV obstruction. LV function is more compromised than RV in both groups. RV hypoplasia is rare but was documented in both uncomplicated forms and forms with RV obstruction.


Total effective compliance, cardiac output and fluid volumes in essential hypertension. Total effective compliance, hemodynamic parameters, extracellular fluid volume, cardiopulmonary (CPBV) and total blood (TBV) volumes were determined in 32 men, including 14 normotensive controls and 18 sustained essential hypertensive patients. The effective compliance was calculated from the changes in central venous pressure recorded simultaneously with the changes in blood volume obtained after a rapid Dextran infusion. In normotensive controls, compliance was 2.08 +/- 0.09 ml/mm Hg/kg and was positively correlated with plasma (r = 0.79) and extracellular fluid (r = 0.84) volumes. In hypertensives, compliance was significantly reduced (1.49 +/- 0.06 ml/mm Hg/kg; P is less than 0.001) and was correlated negatively with the CPBV/TBV ratio (r = -0.75) and positively with the plasma volume/interstitial fluid volume ratio (r = 0.84). These results suggest that in normotensives, there is a regulatory mechanism between volume and compliance and that this contributes to maintaining filling pressure and cardiac output within normal ranges. In hypertensives, the reduced compliance could participate in the maintenance of normal values of cardiac output and extracellular fluid volume by influencing the partition of intravascular and extracellular fluid volumes.


Lactic dehydrogenase isoenzyme determination in the diagnosis of acute myocardial infarction. Lactic dehydrogenase (LD) isoenzymes were determined by a rapid, simple technique and their utility in the diagnosis of acute myocardial infarction (AMI) was evaluated. LD isoenzymes were separated by ion-exchange column chromatography using DEAE-Sephadex. The cardiac fractions (LD-1 and LD-2) were measured separately on an Abbott ABA-100 analyzer and ratio of LD isoenzyme 1 to LD isoenzyme 2 (LD1:2) calculated. Daily serum samples were obtained from 100 patients selected only for a history of chest pain of abrupt onset. In 47 patients whose diagnosis was acute myocardial infarction (AMI), confirmed by typical clinical presentation and typical rise in cardiac-specific creatine kinase isoenzyme (MB(, peak LD1:2 ranged from 0.77 to 2.26. In 44 patients without AMI, peak LD1:2 ranged from 0.25 to 0.76. In two patients with electrocardiographic changes chest pain occurred two and five days previously; there was no rise in MB, but LD1:2 was elevated. Four patients with small AMI had no rise in LD1:2. Three more patients (one with active hemolysis) had false positive results. Thus, there was a sensitivity of 96% and a specificity of 97% when the cut-off point was LD1:2 = 0.76. LD1:2 is not quite as sensitive or specific as MD, but the ratio allows for the diagnosis of infarction in cases where MB has already returned to normal.


Nonuniform cardiac sympathetic nerve discharge: mechanism for coronary occlusion and digitalis-induced arrhythmia. This study examined nonuniform postganglionic cardiac sympathetic neural discharge as a possible mechanism involved in the production of coronary occlusion or ouabain-induced arrhythmias. After acute occlusion of the left anterior descending coronary artery in 12 cats, anesthetized with alpha-chloralose and pretreated with atropine, arrhythmia occurred within 3 min in eight animals; three of these died in ventricular fibrillation. In recordings from 15 nerves in the eight animals with arrhythmia, spontaneous discharge increased in nine nerves, decreased in five nerves, and showed no change in one nerve. This nonuniform neural discharge was associated with the development of arrhythmia after occlusion. In four of the cats, neural discharge did not change within the first 3 min after coronary artery occlusion and arrhythmia did not occur. Development of ouabain-induced arrhythmia was accompanied by a nonuniform pattern in the neural discharge (13 cats). This discharge may alter ventricular excitation and conduction to produce arrhythmia.


Comparison of the electrocardiographic changes induced by maximam exercise testing with treadmill and cycle ergometer. Maximum exercise testing using treadmill walking and cycle ergometry was compared in 40 male patients who had suffered a myocardial infarction in the preceeding twelve months. Maximum oxygen uptake was on average 17% greater in the treadmill than the cycle test and maximum heart rate was also higher, but the rate pressure product (RPP) was a similar due to a higher blood pressure in the cycle ergometer test. Eleven subjects showe ST-segment depression greater than 1 min and eight subjects showed ST-segment elevation greater than 1 mm. There was a close relationship (r2 = 0.96) between the magnitude of ST-segment changes in the two tests.  Four subjects showing ST depression of 1 mm in the treadmill test showed depression during the cycle ergometer test which was less than this conventionally "positive" value. In these subjects RPP was lower during cycling than in treadmill walking. With both tests maximum ST-segment changes were measured immediately on stopping exercise: resolution of ST depression was more rapid than ST elevation. The two exercise testing modes are closely comparable in their ability to reveal changes of myocardial ischemia.


QT interval prolongation as predictor of sudden death in patients with myocardial infarction. Fifty-five patients with recent myocardial infarction and 55 healthy controls, matched for age, sex, race, height, weight, education and job, had an electrocardiogram taken every two months for seven years. Twenty-eight patients and one control had a sudden cardiac death. The QTc (mean of all values recorded) was found prolonged in one control (2%), five of 27 surviving patients (18%) and in 16 of 28 patients who had sudden death (57%). The difference between surviving and sudden death patients is significant (P less than 0.01). It is interesting that the only control with a long QT was the one when died suddenly of myocardial infarction. Among patients with previous myocardial infarction a prolonged QTc constitutes a 2.16 times greater risk for sudden death. We conclude that a constant prolongation of QTc in patients with myocardial infarction may help, with other risk factors, in defining a subgroup at higher risk for sudden death.


Right ventricular ejection fraction in patients with acute anterior and inferior myocardial infarction assessed by radionuclide angiography. We measured right and left ventricular ejection fracttion (EF) from high frequency time-activity curves obtained during the initial passage of an intravenous bolus of 99mTc (Sn) pyrophosphate. In 22 normal controls right ventricular EF averaged 0.52 +/- 0.04 (SD). In 24 acute anterior or lateral infarction patients right ventricular EF was normal (0.56 +/- 0.10), while left ventricular EF was reduced (0.45 +/- 0.10, P less than 0.001 vs controls). In 19 acute inferior infarction patients left ventricular EF also was depressed (0.51 +/- 0.09, P less than 0.001 vs controls). Among 7 of 19 inferior infarction patients with right ventricular by scintigraphy, right ventricular EF was reduced (0.39 +/- 0.05; P less than 0.001 vs normals; P less than 0.01 vs inferior infarction patients without right ventricular involvement). In the latter group right ventricular EF averaged 0.51 +/- 0.10 (NS vs normals). We conclude 1) a single injection of 99mTc (Sn) pyrophosphate can identify right and left ventricular dysfunction and infarct location in acute myocardial infarction, 2) right ventricular EF is well-preserved except when inferior infarction involves the right ventricle.


Reduction of enzyme levels by propranolol after acute myocardial infarction. The effect of propranolol (0.1 mg/kg intravenously followed by 320 mg given over 27 hour orally) on serum levels of creatine kinase enzyme was studied in a randomized trial involving 95 patients seen within 12 hours of onset of symptoms of uncomplicated myocardial infarction. In 15 patients who were treated with propranolol within 4 hours of onset, and who eventually developed pathological Q waves, peak measured enzyme levels were 27% (P less than 0.0125) lower than in 19 control patients who were also seen within 4 hours of the onset but had no specific treatment. Total calculated enzyme appearance was also lower in the treated patients (reduced 25%, P less than 0.05) as was the calculated rate of the appearance (33%, P less than 0.005). No significant difference was found for treated compared with control patients entering the trial more than 4 hours after the onset of chest pain. This evidence suggests that propranolol may reduce the size of uncomplicated infarctions if it is given intravenously within 4 hours of the onset.


Variability, reproducibility, and applications of precordial ST-segment mapping following acute myocardial infarction. In 58 patients with uncomplicated acute anterior myocardial infarction, a mean decline in the sum of ST segments (sigmaST) of 34% was observed when comparing sigmaST values recorded at 3-6 hours with those recorded at 6-9 hours after the onset of symptoms (P less than 0.05). The mean absolute difference between 19 paired readings 1-2 hours apart was 2.9 +/- 3.0 mm and between 29 readings 2-4 hours apart 3.0 +/- 3.0 mm. However, the mean absolute difference between 38 paired readings 4-8 hours apart was 12.2 +/- 11.8 mm with a wide range of differences. Left ventricular failure and pericarditis were also associated with significantly higher sigmaST values. We conclude that there is a complex relationship between ST-segment elevation and a number of clinical factors during the first 48 hours after infarction. Nevertheless, precordial mapping remains a useful method for the evaluation of short-term (less than 4 hours) therapeutic interventions, if other relevant variables are unaltered and if carefully matched control groups are employed.


Antiarrhythmic drug effect mimicked by spontaneous variability of ventricular ectopy. Twenty patients with frequent ventricular ectopic beats had a 5 1/2 hour ECG rhythm strip recorded. Individual patients showed a marked spontaneous variability from one half-hour to the next in the total number of ectopic beats (-99% to +1100%) and the occurrence of pairs or salvos. Although no patient received antiarrhythmic drugs, some patients showed a spontaneous change in arrhythmia which mimicked either drug suppression or drug-induced worsening of arrhythmias. If an antiarrhythmic drug had been given to these patients after the first half-hour, 65% would have been termed "drug responders," using the criteria of 50% reduction in ectopic beats and elimination of pairs or salvos during any half-hour period in the subsequent three hours. Spontaneous variability in ventricular ectopic beats causes serious problems when using ECG monitoring to evaluate antiarrhythmic drug response in individual patients. The arrhythmias averaged for the entire group remained stable during the recording period. Evaluating antiarrhythmic drugs by examining group response rather than individual patient response minimizes the effect of spontaneous variability.


An ultrastructural basis for electrocardiographic alterations associated with Duchenne's progressive muscular dystrophy. Electrocardiographic abnormalities were identified in 63 (84%) of 75 patients with Duchenne's progressive muscular dystrophy. A tall R wave over V1 with an abnormal R/S ratio was seen in 64% of the patients, a deep and narrow Q wave greater than 4 mm over leads I, V5, and V6 in 44%, sinus tachycardia in 32% and right axis deviation in 16%. Other ECG abnormalities included an abnormal PV1 index in 14% of patients and a short P-R interval in 6%. Ultrastructural characteristics of the heart were determined for two patients with characteristic electrocardiographic abnormalities. Common to both hearts was a total loss of thick as well as thin myofilaments, which gave a "moth-eaten" appearance to the myofiber. This feature, combined with preservation of the transverse tubular system, formed the most characteristic ultrastructural finding and was seen most consistently in the posterobasal area of the left ventricle. Alterations of Z-band material; accumulation of mitochondria, occasionally containing electron-dense bodies and showing loss or discontinuity of cristae; dilatation of sarcoplasmic reticulum with striking ectasia of cisternae; depletion of glycogen particles; a paucity of lipoid or lipochrome granules; and the absence of virus-like particles were other consistent ultrastructural features. Comparison of skeletal and cardiac muscle disclosed identical subcellular changes. These observations support the contention that the distinctive ECG pattern associated with Duchenne's dystrophy results from multifocal degenerative changes involving myocardium, predominantly the posterobasal region of the left ventricle and the posterior papillary muscle.


The posterior left atrial echocardiogram of mitral regurgitation. The motion of the posterior wall of the normal left atrium has not been studied systematically. The superoposterior portion of the left atrium is adynamic throughout the cardiac cycle, whereas the inferoposterior portion is displaced posteriorly with left atrial filling during ventricular systole. In the present study, the left atrial diameter (LAD), the left atrial systolic motion (LASM) and the left atrial systolic velocity (LASV), were determined in the following groups of patients: 34 normals; eight patients with either coronary artery disease or aortic stenosis; six patients with aortic insufficiency; and three patients with ventricular septal defect. The results obtained were compared to 15 patients with angiographically documented mitral regurgitation. In the last group, the LAD (4.2 +/- .19 cm) and LASV (12.3 +/- 1.23 cm) and LASM (1.2 +/- 0.4 cm) were significantly greater reflecting the early accentuated filling of the left atrium induced by mitral regurgitation. As well, the product of these three parameters was greater in the mitral regurgitation group (63.2 +/- 7.34 cm3/sec) than in the other groups and patients with mild to moderate regurgitation had a significantly lower value than those with moderate to severe regurgitation (45.7 +/- 4.1 vs 78.5 +/- 10.9, P less than 0.02). The left atrial echocardiogram, therefore, is an aid in the diagnosis of mitral regurgitation and provides a rough index of the severity of the lesion.


Echocardiographic differentiation of partial and complete atrioventricular canal. Retrospective examination of echocardiograms was performed in 34 patients with persistent atrioventricular (A-V) canal who had undergone cardiac catheterization. Characteristic findings in 16 patients with partial A-V canal were lack of continuity of mitral and tricuspid valves, paradoxical interventricular septal motion, definite E and A waves of the mitral valve anterior leaflet (MVAL) echoes and late systolic anterior motion of the mitral valve. Eighteen patients with persistent A-V canal had an interventricular communication and were classified as having the complete form. They characteristically had continuous mitral and tricuspid valves, normal interventricular septal motion, disorganized MVAL echoes, and normal systolic mitral valve motion. Combining these findings allowed differentiation of 31 of the 34 patients (91%) as having partial or complete A-V canal. Determining the presence of a VSD from loss of interventricular septal echoes was unsatisfactory. The severity of mitral insufficiency could not be estimated from echocardiograms of our patients with partial A-V canal.


Echocardiographic estimation of pulmonary artery pressure in transposition of the great arteries. To determine their usefulness in estimating pulmonary artery pressure, left ventricular systolic time intervals (STI) were determined by echocardiography in 65 patients with dextro-transposition of the great arteries (TGA). The STI were measured from recordings of pulmonary valve motion at 100 mm/sec paper speed. The pre-ejection period (PEP) and the ratio of PEP to left ventricular ejection time (PEP/LVET) were directly related to pulmonary artery pressure. The strongest correlations were that between PEP/LVET and pulmonary artery diastolic pressure (r = 0.70) and that between PEP/LVET and the ratio of mean pulmonary pressure to mean systemic pressure (r = 0.71). A value of PEP/LVET of less than 0.26 was consistently associated with pulmonary artery diastolic pressures of less than 20 mm Hg and, in 28 of 31 patients, pulmonary artery pressure less than one-third of mean systemic arterial pressure. Pulmonary hypertension was present in 18 of 22 patients with PEP/LVET of 0.30 or greater; elevated PEP/LVET was also present in four patients with abnormalities of cardiac rhythm or conduction, two of whom also had angiographic evidence of myocardial dysfunction.


Echocardiographic features of the interventricular septum in chronic constrictive pericarditis. Echocardiographic characteristics of the interventricular septum (IVS) have been studied in eight patients with chronic constrictive pericarditis (CP). Values of septal thickening (ST) were clearly below normal in all cases. Interventricular septal systolic motion (IVSSM) was normal in four cases, hypokinetic in three and paradoxical in one. In seven out of the eight patients, an early interventricular septal diastolic motion (IVSDM) consisting of a sudden anterior displacement followed by a brisk posterior rebound was recorded. The beginning of this anomalous movement was coincident with the pericardial knock in the phonocardiogram and its peak was coincident with the simultaneously recorded deep "y" trough in the jugular pulse tracing. The tendency toward normality of IVSDM observed after pericardiectomy in six out of seven patients suggests that this peculiar interventricular septal systolic motion may be a frequent and probably specific echocardiographic finding in constrictive pericarditis.


Short-term intramuscular therapy with procaine penicillin plus streptomycin for infective endocarditis due to viridans streptococci. Thirty-three patients with viridans streptococcal infective endocarditis were treated for two weeks with intramuscular procaine pencillin, 1.2 million units every 6 hours, plus streptomycin, 500 mg intramuscularly every 12 hours. Nine patients (27%) had infections with relatively penicillin-resistant microorganisms (MIC greater than 0.1 microgram/ml or MBC greater than or equal 3.12 microgram/ml). Follow-up ranged from 2 months to 3.5 years. There were no relapses; Mild vestibular toxicity developed in one patient. One patient died two months after completion of antimicrobial therapy from sudden onset of severe congestive heart failure; Seven patients required cardiac valve replacement after completion of antimicrobial therapy. None died. We believe that this therapeutic regimen is effective antimicrobial therapy for infective endocarditis caused by viridans streptococci, irrespective of in vitro microbiologic data.


Impairment of antipyrine clearance in humans by propranolol. The effect of propranolol on antipyrine clearance in humans was evaluated in six healthy volunteers who received single 1.4 to 1.5 g doses of intravenous antipyrine on two occasions. The first (control) antipyrine trial was without concurrent drug administration; the second trial was done during treatment with therapeutic doses of propranolol (40 mg every 4 to 6 hours). Antipyrine elimination half-life (t1/2), volume of distribution (Vd), and total clearance were determined after each trial. In all subjects isoproterenol sensitivity decreased markedly during propranolol treatment, indicating a high degree of beta blockade produced by the drug. Mean antipyrine t1/2 during the propranolol treatment period was significantly prolonged, and total clearance significantly reduced, over the control values. Twenty-four-hour urinary excretion of 4-hydroxyantipyrine, the major metabolite of antipyrine, likewise was reduced from 23.6% of the dose on the control trial to 14.8% of the dose during propranolol coadministration (0.1 less than P less than 0.2). Vd however, was nearly identical during both trials (0.62 L/kg). Thus propranolol prolongs the half-life and reduces the clearance or biotransformation rate of antipyrine, a drug whose clearance is independent of hepatic blood flow. Propranolol may influence the activity of hepatic microsomal enzymes responsible for drug hydroxylation.


Pressor response to saralasin (1-sar-8-ala-angiotensin II) bolus injection in hypertensive patients. A 10 mg bolus of the angiotensin blocker saralasin was injected 113 times in 68 subjects with essential or renovascular hypertension. Ninety percent of injections caused a transient increase in blood pressure, which correlated with plasma renin activity (PRA) (r = -0.54); Mean increase at 2 minutes was 21/13.4 mm Hg (P less than 0.001) and was independent of pre-injection control blood pressure, with a rapid decrease to or below control values thereafter. Thirty-seven subjects were studied on successive days before and after furosemide-induced sodium depletion (152 +/- 26 mEq [SE] sodium loss). In the low renin group, sodium depletion did not change PRA or the magnitude of the pressor response to saralasin, but significantly decreased control MAP by 13 mm Hg (P less than 0.01). In normal and high renin patients, MAP was unchanged after diuresis, but PRA increased significantly and the pressor response was attenuated. The net effect of sodium depletion was to reduce the pressor response to saralasin in all renin subgroups by 9 to 12 mm Hg. Saralasin bolus injection, unlike infusion, saturates available vascular receptors only briefly, eliminating prolonged pressor responses.


Pulmonary hemodynamics and right ventricular function in hypertension. Pulmonary and systemic hemodynamics in 16 hypertensive subjects (group I) with left ventricular (LV) hypertrophy (ECG and echo criteria) and in 17 hypertensive subjects with ECG signs of LV strain (group II), were compared with those in 14 normal individuals. An augmented pulmonary arteriolar resistance (PAR) in group I and to a larger extent in group II accounted for the pulmonary pressure elevation in both groups. Increase in PAR was unrelated to pulmonary blood flow and volume, pleural pressure, arterial PO2, PCO2 and pH, and could not be explained entirely by the left ventricular end-diastolic pressure changes. In group I, left (L.MSEJR) and right (R;MSEJR) mean systolic ejection rate, stroke index (SI) and mean velocity of circumferential fiber shortening (VCF) were enhanced in spite of the heightened pressure load on both sides of the heart. In group II, a large reduction of SI, L.MS.EJR, R.MSEJR and VCF, as well as the relationship between ventricular filling pressures and SI, documented a compromised performance of both ventricles, Findings indicate that: systemic hypertension is associated with elevation of pulmonary arterial pressure and of PAR which is not necessarily a consequence of impairment in LV function; LV hypertrophy is associated with enhanced performance of either ventricle; in coincidence with development of ECG signs of LV strain, the performance of both sides of the heart deteriorates. A functional interdependence of the two ventricles is suggested.


Alteration of the left ventricular diastolic pressure-segment length relation produced by the pericardium. Effects of cardiac distension and afterload reduction in conscious dogs. Left ventricular pressure and segment length were measured in seven conscious chronically instrumented dogs with the pericardium intact and 3-9 days after pericardiectomy. Diastolic pressure-length plots were obtained under control conditions and after acute volume loading followed by sodium nitroprusside infusion. In all dogs with intact pericardium, volume loading displaced the entire diastolic pressure-length curve upwards and sodium nitroprusside shifted it toward control. After pericardiectomy the pressure-segment length data during control, volume loading and sodium nitroprusside fell on a single curve (intercepts and slopes not statistically different); After dextran infusion, intrapericardial pressure rose from control 1.5 +/- 0.7 mm Hg to 8.2 +/- 0.5 mm Hg, and it fell to 4.8 +/- 0.1 mm Hg after nitroprusside. Therefore, in acute cardiac dilatation the pericardium contributed significantly to the increased left ventricular diastolic pressure and to the fall during sodium nitroprusside infusion and appeared responsible for shifts in the diastolic pressure-segment length relation.


Cardiac function in the normal newborn: additional information by computer analysis of the M-mode echocardiogram. Computer analysis of the M-mode echocardiogram in 50 normal newborns provided measurements of wall thicknesses and chamber size and, in addition, assessment of right and left ventricular wall, septal, and cavity dynamics throughout the cardiac cycle. Data obtained with this new technique indicated that (1) right and left ventricular cavity functions are similar in the normal newborn, (2) right and left ventricular cavity filling and emptying vary directly with peak rates of septal and ventricular wall thinning and thickening, respectively, and (3) there is a close time relationship among maximum left atrial dimension, minimum left ventricular dimension, and mitral valve opening. This analysis, which is the first complete analysis of the echocardiogram in the newborn, provides a normal range of septal and ventricular wall dynamics as well as right and left ventricular and left atrial function and has clinical implications in that it may allow early recognition of both congenital and perinatal myocardial disease.


Clinical, angiographic, and hemodynamic assessment of late results after Mustard operation. Since 1974, late results of the Mustard procedure for correcting complete transposition of the great arteries have been evaluated by cardiac catheterization, electrocardiography, roentgenography, history, and physical examination of 48 Mayo Clinic patients. Of these, 15 were studied 1 month to 2 years postoperatively because of clinical deterioration. The other 33 had been asymptomatic but were asked to return for hemodynamic reevaluation one-half to 11 years postoperatively. Of the asymptomatic group, 19 underwent exercise electrocardiography prior to catheterization and eight performed supine exercise during catheterization. Cardiac catheterization proved the most effective mode of study. Significant cardiovascular abnormalities (caval obstruction, residual pulmonary stenosis, etc.) were found in 35 of the 47 patients--including 20 of the 33 who were asymptomatic. Eight of the symptomatic group and three of the others have died since this restudy. These poor results warrant renewed effort to devise better methods for correcting complete transposition,


De subitaneis mortibus. XXX. Observations on the pathophysiology of the long QT syndromes with special reference to the neuropathology of the heart. Eight patients (different families) with syncopal attacks and a long QT interval in the ECG died suddenly. Five heard normally and three were born deaf. At postmortem examination of all eight hearts the single consistent abnormality was focal neuritis and neural degeneration within the sinus node, A-V node, His bundle and ventricular myocardium. Although the etiology of this intracardiac neural disease is uncertain, a chronic viral infection or some noninfectious degenerative process are among the plausible causes discussed. If intracardiac neuritis and neural degeneration prove to be a prevalent finding among other victims dying from the long QT syndromes, further consideration should be given to whether there is any genuine hereditary component in the pathogenesis. Because of the asymmetrical and focal distribution of the cardioneural lesions, the response to present forms of medical or surgical treatment of the lung QT syndromes may vary from benefit to harm. Until more is known of the true etiology of the neural disease, treatment will probably remain empirical in nature and should be conducted with cautious clinical observation.


Method-specific variations in the calibration of a new immunoglobulin standard suitable for use in nephelometric techniques. The putative International Federation of Clinical Chemistry immunoglobulin standard, IFCC 74/1, was calibrated against the World Health Organization (WHO) immunoglobulin standard 67/99 by three different methods: automated immunoprecipitation, Laurell rocket immunoelectrophoresis, and radial immunodiffusion. The same antisera were used in all the assays, which were performed in five expert laboratories. With the aid of linearizing transformations for the dilution curves of both materials and use of a carefully weighted statistical evaluation, values in International Units for IgG, IgA, and IgM were ascribed to IFCC 74/1. The values achieved by the three different methods were not statistically different, except in the case of IgA. IgM assays by automated immunoprecipitation were excluded owing to a high degree of imprecision.


Gas-chromatographic determination of polyol profiles in cerebrospinal fluid. We describe a simple method for collectively determining polyols in the cerebrospinal fluid. The method consists of protein removal, sample derivatization, and gas chromatography of the trimethylsilylated polyols, with use of glass capillary columns. Nine major polyol constituents, the structures of which were verified by combined gas chromatography/mass spectrometry, can be simultaneously assayed. The presence of three polyols in the cerebrospinal fluid is reported here for the first time.


A radioimmunoassay for nortriptyline (and other tricyclic antidepressants) in plasma. The radioimmunoassay for nortriptyline described here can detect as little 1 microgram/liter of plasma. Within-day precision and day-to-day precision (CV) were +/- 6 and +/- 11%, respectively, over the concentration range 100-200 microgram/liter. The major metabolite hydroxy-nortriptyline, does not cross react with the antiserum. Results so obtained correlate closely with results by a double-isotope derivative dilution technique. The major advantages of this technique over currently available methods are its sensitivity, convenience (many samples can be processed in one day), simplicity, and cost. Further, prior extraction of plasma samples is not required. Cross-reactivity studies have been carried out with all other available tricyclic antidepressants. The antiserum has the ability to bind these drugs, thus radioimmunoassay for all the tricyclic antidepressant drugs can be set up because concurrent use of more than one of these drugs is rare.


New ultraviolet (340 nm) method for assay of uric acid in serum or plasma. We propose a novel enzymatic method for assay of uric acid at 340 nm, which eliminates several disadvantages of both the colorimetric and enzymatic methods now in common use. Here, uric acid is catalytically oxidized to allantoin and hydrogen peroxide. The peroxide is reacted with ethanol in the presence of catalase to form acetaldehyde and water, and the acetaldehyde is reduced by NADH in the presence of alcohol dehydrogenase to ethanol. The decrease in absorbance at 340 nm caused by oxidation of NADH is directly proportional to the concentration of uric acid in the sample. Measurement of the change in absorbance between 20 and 200 s eliminates the need for a serum blank measurement. Absorbance and concentration are linearly related to 120 mg of uric acid per liter. The new method was compared with the uricase method in which decomposition of uric acid at 293 nm is directly measured. The results for the 47 patients' sera so examined can be expressed by the linear equation y340 = 1.0078x293 + 0.122 (r = 0.9984).


Comparison of double- and single-isotope enzymatic derivative methods for measuring catecholamines in human plasma. We directly compared the reliability of a single-isotope enzymatic derivative technique for measurement of plasma catecholamines with that of the well-established double-isotope method. A significant (p less than 0.001) correlation was observed between measurements (n = 52) in the two assays, both for norepinephrine (r = 0.97) and epinephrine (r = 0.80). Means and coefficients of variation for the two analytes in a pooled specimen of plasma, measured repeatedly during six months, were virtually identical by each assay method. Basal plasma catecholamine concentrations in two different groups of apparently healthy subjects were also similar by each method. Dopamine concentrations in plasma were consistently below the limits measurable by either technique. The single-isotope assay requires half the assay time and 1/200th the sample as the double-isotope method. We conclude that this assay is just as reliable as the double-isotope technique and gives virtually identical values for norepinephrine and epinephrine concentrations in the physiological range.


The "Southmead System," a simple, fully-automated, continuous-flow system for immunoassays [Appendix: application to serum thyroxine radioimmunoassay]. A simple, fully-automated, continuous-flow system suitable for radioimmunoassay, enzyme immunoassay, and fluoro-immunoassay is described. The system is versatile, inexpensive, and requires only equipment and skills that already are available in most clinical chemistry laboratories. In this system, the antibody is covalently linked to solid-phase, porous particles of agarose (Sepharose, size 40-70 micrometer in the dry form). After sampling and mixing the assay reactants, the assay "cocktail" containing the solid-phase-bound antigen and the unbound fraction is directed to the separation block. Separation is achieved by use of a highly porous membrane (pore size, about 10 micrometer) and by controlling the volume of inflow and outflow a fixed and precise amount of fluid is filtered through the membrane containing only the free (unbound fraction), which can then be quantitated. The percentage of unbound fraction misclassified is negligible (less than 1.0%). Application of these principles to the assay of serum thyroxine is described in an appendix.


Measurement of sodium in albumin solutions with ion-selective electrodes. We have investigated the variations in the potentials of sodium-selective glass-membrane electrodes in various concentrations of albumin. These protein solutions serve as a simple model for measurements of electrolytes in whole blood, plasma, or serum with such an electrode. The results indicate that albumin-sodium binding and variations in liquid-junction potentials are of negligible importance. Mostly, the effect of albumin on the sodium glass-electrode potential is attributable to variations in the activity of sodium, determined by the water content of the solutions. We have calculated apparent fractional protein volumes in albumin solutions from measurements of sodium glass-electrode potential and find they compare well with the classical McLean-Hastings formulation. Our results indicate the need to correct experimentally determined potentiometric electrolyte concentrations for protein volumes.


Determination of serum alpha-tocopherol (vitamin E) by high-performance liquid chromatography. We report a fast, simple high-performance liquid-chromatographic assay for serum alpha-tocopherol, with use of a reversed-phase column and tocol as internal standard. Only 200 microliter of serum is required. Isocratic elution of the n-hexane extract is done within 6 min; total analysis time is less than 1 h. Within-day precision (CV) was 2.3% for 24 samples of a normal plasma pool (mean concn, 10.1 mg/liter). Day-to-day precision (CV) was 3.2%, measured for 20 days for a specimen with a concentration of 10.8 mg/liter. Analytical recovery of alpha-tocopherol from fortified serum was 89 to 100%. The lower detection limit of alpha-tocopherol is estimated to be 0.6 mg/liter. The specificity of the procedure was verified by spectrophotometry, gas-liquid chromatography, and combined gas chromatography/mass spectrometry of an eluate collected from the column.


Micromethod for estimating adenosine deaminase activity in dried blood spots on filter paper. We describe a fluorometric micromethod for measuring adenosine deaminase activity in dried blood spots on filter paper. Earlier methods require venipuncture and preparation of washed erythrocytes; in the present method, whole capillary blood, spotted on filter paper and mailed (dried) to a central laboratory, is used. The stability of the enzyme in dried blood on filter paper was assessed. The results were compared with those of a spectrophotometric method. The presence of serum appears not to affect the estimation of the activity and the method may be useful in early detection of severe combined immunodeficiency disease and hereditary hemolytic anemia.


Characteristics of statistical parameters used to interpret least-squares results. This paper discusses properties of several statistical parameters that are useful in judging the quality of least-squares fits of experimental data and in interpreting least-squares results. The presentation includes simplified equations that emphasize similarities and dissimilarities among the standard error of estimate, the standard deviations of slopes and intercepts, the correlation coefficient, and the degree of correlation between the least-squares slope and intercept. The equations are used to illustrate dependencies of these parameters upon experimentally controlled variables such as the number of data points and the range and average value of the independent variable. Results are interpreted in terms of which parameters are most useful for different kinds of applications. The paper also includes a discussion of joint confidence intervals that should be used when slopes and intercepts are highly correlated and presents equations that can be used to judge the degree of correlation between these coefficients and to compute the elliptical joint confidence intervals. The parabolic confidence intervals for calibration cures are also discussed briefly.


Serum estradiol-17 beta as determined by mass fragmentography and by radioimmunoassay. We describe the preparation of [2,4,16,16-2H4]estradiol-17 beta. The method for quantitative determination of subpicomole amounts of estradiol-17 beta (trimethylsilyl ether derivatives) by gas-liquid chromatography-mass spectrometry with multiple ion detector and with [2H4]estradiol-17 beta as the carrier is presented and characterized. Values for serum samples, as measured by radioimmunoassay and by mass fragmentography, agreed well.


Evaluation of an aqueous fluorometric continuous-flow method for measurement of total urinary estrogens. Measurement of urinary estrogen excretion is used extensively to monitor fetal welfare in utero, allowing the fetus at risk to be identified. We evaluated a direct all-aqueous fluorometric method adapted to a continous-flow (AutoAnalyzer I) system, using a spectrofluorophotometer for detection. In this method, which is based on a modified Kober reaction, NaBH4 is used to eliminate the known negative interference of glucose. The mean analytical recovery was 98%. Urines from 15 men showed no blank fluorescence. Comparison studies of the fluorometric method (x) and a manual method based on the Kober/Ittrich reaction (y) yielded the equation y = 1.53x + 4.38 (r = 0.9235). The incomplete correlation can be explained by erratic extraction in the manual Kober/Ittrich procedure (mean recoveries were 57%). A day-to-day precision (CV) of 5.2% can be achieved with the automated method. Samples are analyzed at a rate of 20 per hour, but this rate can be doubled, if necessary, without significant carryover problems. We conclude that the automated fluorometric method is accurate, precise, and inexpensive and therefore the method of choice for measuring urinary estrogens.


Analysis for potassium in human erythrocytes by use of a standard-additions method and an ion-selective electrode. A method based on standard additions to the sample was used to measure potassium (K+) in human erythocytes with an ion-selective electrode. A computer program was developed for rapid analysis of data obtained with the electrode. The analysis takes into account factors such as temperature that may affect electrode behavior. Results obtained by the method agree with those obtained by flame-emission spectroscopy. The coefficient of correlation between the two methods is 0.96. Our method is simple and rapid. The computer program is applicable to other analyses with ion-selective electrodes.


A technique for determining the probability of abnormality. Histograms of the results of quantitative clinical laboratory analyses are usually broadly skewed because some of the patients have normal values with respect to the analyte being measured while values for others are below or above normal. We describe a technique for calculating the maximum possible number of individuals in a patient population who will give normal values and, by difference, the minimum possible number of those who will give below-normal and above-normal values. The technique permits estimation of the probability that any given result represents a member of a particular subpopulation, as well as selection of decision limits for patient classification, and estimates the degree of change required for a subject with a normal value to start giving below- or above-normal values.


Free thyroxine in serum as estimated by polyacrylamide gel filtration. In this new method for estimating free thyroxine concentration in serum by use of polyacrylamide gel filtration, the prolonged incubation that is characteristic of equilibrium dialysis is obviated. Although the values so obtained for the percentage of free thyroxine are severalfold higher than those obtained by dialysis, the results of the two procedures correlate well over a wide range of thyroid states. In addition, the precision of the polyacrylamide method compares well with that for equilibrium dialysis. The method is convenient for use in clinical laboratories and values for free thyroxine in serum of patients with metabolic thyroid disorders are diagnostically discriminatory.


Effect of storage on the apparent concentration of folate in erythrocytes, as measured by competitive protein binding radioassay. The folate concentration in erythrocytes changes during incubation. Using whole blood samples and washed erythrocytes, I find greatly increasing concentrations of folate in washed samples at 37 degrees C, decreasing concentrations in whole-blood samples. This difference in behavior depends on a thermostable, ultrafiltrable factor in plasma. Exclusion of glucose or addition of fluoride did not affect these results. Decreasing concentrations of folate were found when iodoacetate or acetylphenylhydrazine was present. At 4 degrees C the concentrations of folate were stable for 72 h. I discuss possible explanations for the observed changes and their practical significance.


Screening for urinary oligosaccharides: a quantitative procedure. A method for screening urine for abnormalities in glycoconjugate excretion is presented. An oligosaccharide-containing fraction is isolated from urine by gel chromatography and the carbohydrate-containing components in this fraction are degraded to monosaccharides, suitable derivatives of which are analyzed by gas-liquid chromatography. A pattern which characterizes the monosaccharides originating in complex carbohydrates in urine is thus obtained. Data obtained by applying this method to normal subjects in various age groups are presented and the applicability of the method and its limitations are illustrated by the use of examples from patients with previously diagnosed disorders of glycoconjugate metabolism.


Detection and elimination of contaminations interfering with the determination of zinc in plasma. We undertook detailed examination of the practices and procedures involved in the analysis of serum for zinc by atomic absorption spectrophotometry, to identify possible sources of zinc contamination. Some degree of contamination was found in almost all steps of the procedure. These findings are presented and alternative materials and procedures are described that significantly decrease or eliminate contamination from extraneous zinc. The plasma of 76 normal adults was analyzed by the revised procedure, and a lower mean value was obtained than has been previously reported.


Determination of cadmium in urine by graphite-furnace atomic absorption spectroscopy. A simple procedure for graphite-furnace atomic absorption analysis of cadmium in urine, based on the use of a temperature-controlled heating unit, is described. The temperature of the carbon rod is measured by resistance and controlled by electronic feedback. We studied the influence of various heating times and temperatures of ashing and atomization, as well as suitable diluents. Urine samples were diluted with an equal volume of 0.3 mol/liter HNO3, and 1 to 5 microliter of the mixture was analyzed, with background correction. Signals were evaluated electronically, giving values for integrated peaks as well as for peak heights. The detection limit was 1.2 nmol/liter. The method appears to be accurate and reproducible. The CV averaged 8% for concentrations in the range 20 to 100 nmol/liter. Correlations with a chelation-extraction method was 0.994.


Time--concentration studies by high-performance liquid chromatography of metabolites removed during hemodialysis. Reversed-phase high-performance liquid chromatography was used to study the efficiency of hemodialysis. The method, previously used to study uremic hemodialysate, was also found useful for analyzing other uremic biofluids, such as serum and urine. Samples of blood (centrifuged to obtain cell-free serum) and hemodialysate were simultaneously collected from selected patients at regular intervals during the entire 6-hour hemodialysis treatment. These samples were filtered through membranes to remove particulates and proteins and were then analyzed by use of a 60-cm muBondapak-C18 column, an aqueous sodium acetate/methanol gradient, and detection at 254 nm. The identification of components in the eluate was based on retention times, ultraviolet absorption spectra, and mass spectra. From the amounts of several metabolites in the various physiological fluid pools during hemodialysis, we concluded that they mostly originate from tissue fluids. We also observed that the concentrations of most components in serum and hemodialysate fluctuated regularly with time.


Gas-chromatographic determination of nanogram amounts of enantiomers of nortilidine, a main metabolite of tilidine, in biological specimens. We report a specific and sensitive method for determination of the individual optical isomers of nortilidine, a main metabolite of tilidine, with the aid of a nitrogen-sensitive detector. With N-trifluoroacetyl-L-leucyl chloride as chiral reagent, the diastereomeric derivatives of the nortilidine enantiomers could be separated and quantified in the nanogram range. Under these conditions, the enantiomers of bisnortilidine, another main metabolite of tilidine, were also separated. Investigations in rats with the enantiomers of tilidine and nortilidine indicated that no racemization occurs during N-demethylation in the organism. After oral and intravenous administration of 50 mg of tilidine.HCI to a human volunteer, identical concentrations of nortilidine enantiomers were found in the plasma.


Improved technique for developing creatine kinase isoenzyme bands by using a substrate in gelatin matrix. We describe a simple technique for reacting CK isoenzymes with a substrate in gelatin to make them visible after they have been separated by cellulose acetate electrophoresis. The electrophoresed strip requires only 5 min of contact with the substrate in gelatin and about 12 min of drying in an oven at 55 degrees C. The developed isoenzyme bands are discrete, intense, and rectangular in shape. The technique has a sensitivity of 2 to 5 U/liter, and results for isoenzyme MB can be reported about 30 min from the time a specimen is received.


Carotenoids in the leukocytes of carotenemic and non-carotenemic individuals. Leukocytes and leukocyte membranes isolated from the blood of carotenemic (serum carotene, 4.0 mg/liter) and non-carotenemic individuals were found to contain small amounts of carotenoid pigments. The principal pigment isolated from the leukocyte membranes of carotenemic individuals was beta-carotene. Traces of beta-carotene and other carotenoids were found in the leukocytes and leukocyte membranes of the non-carotenemic individuals.


Cross reactivity of digitoxin and spironolactone in two radioimmunoassays for serum digoxin. We measured the cross reactivity of two medications--digitoxin and spironolactone--in two digoxin radioimmunoassay (liquid and solid-phase) kit procedures. Both tests showed similar average percentages of cross reactivity with digitoxin (7.2 and 8.9% for intravenous, and 11.9 and 10.9% for oral administration), but no cross reactivity with spironolactone or its metabolites after equal intravenous or oral doses.


Screening for urinary oligosaccharides: application to a mentally handicapped population and to patients with some other diseases. The method for screening urinary oligosaccharides described in the accompanying paper [Clin. Chem. 24, 669 (1978)] has been applied to a large group of mentally handicapped patients as well as to patients with cystic fibrosis, malignant disease, and schizophrenia. The cause of the mental handicap was unknown in most cases. The primary object of the study was to investigate a possible link between some diseases and urinary complex carbohydrates. Our results show that abnormalities that are detectable in this way do not contribute significantly to the overall incidence of mental handicap, nor are they expressed in the other diseases studied.


Studies on lipoperoxide of normal pregnant women and of patients with toxemia of pregnancy. 1. Serum lipoperoxide was determined by the method of Yagi et al. (Yagi, K., Nishigaki, I. and Ohama, H. (1968) Jap. J. Vitamin 37, 105) for 22 cases of non-pregnant women, 24 cases of 1st trimester of pregnancy (1-12 weeks), 39 cases of 2nd trimester of pregnancy (13-26 weeks), 58 cases of 3rd trimester of pregnancy (27-40 weeks), and 30 cases of toxemia of pregnancy (27-40 weeks). Remarkable increases of lipoperoxide were observed at 2nd and 3rd trimester of pregnancy compared with non-pregnant women, and the increase in toxemia of pregnancy was more remarkable than that at 3rd trimester of pregnancy. In umbilical cord blood a higher level of lipoperoxide was observed in patients with toxemia of pregnancy than in normal pregnant women. 2. The total TBA value determined by extracting the serum-lipids with chloroform and methanol solution showed a similar tendency to the above. 3. Those showing TBA-reaction by the analysis of lipids with thin-layer chromatography were the fractions of cholesterol ester, triglyceride and phospholipid. While triglyceride fraction showed a marked increase of TBA value during pregnancy and in toxemia of pregnancy.


The measurement of pregnancy specific beta1-glycoprotein by electroimmunodiffusion. A method is described for measuring the concentration of a specific glycoprotein secreted by the placenta into the maternal circulation, by electrophoresis, in antibody-containing agarose ("rocket" technique). The concentration of the protein can be measured from 10 weeks of pregnancy to term.


Organic acids in amniotic fluid.

Organic acids in amniotic fluid. The organic acids of human amniotic fluid were studied by gas chromatography and mass spectrometry. About 30 acids were identified. A "normal" metabolic profile of acids was established which can provide the basis for the identification of abnormal patterns.


Studies of beta-glucuronidase in first-trimester placenta, term placenta and hydatidiform mole. The specific activity and isoenzyme pattern of beta-glucuronidase (beta-D-glucuronide glucurononosohydrolase, EC 3.2.1.31) from first-trimester placenta, term placenta and hydatidiform mole were compared. Enzyme activity is highest in term placenta and lowest in hydatidiform mole, reflecting the steroid conjugation requirements of the tissues. The difference in enzyme activity is due to variation in the level of one isoenzyme form (isoenzyme B) of beta-glucuronidase, which is absent in molar tissue. The possible cause for the changing isoenzyme pattern is discussed.


Modification of the alkaline picrate assay for creatinine to prevent spuriously elevated values by keto acids. Acetoacetate and pyruvate, sometimes present in patients' serum in abnormal amounts, interfere, like other keto acids, with the determination by some usual procedures of creatinine. Acetoacetate can be responsible for overestimation of "creatinine" in the order of 400 mumol/l in sera of ketotic diabetics, fasting subjects and other patients with ketosis. The pseudocreatinine reaction of acetoacetate increases with increasing concentration of NaOH and picrate. Pyruvate causes falsely elevated values, especially at high picrate concentrations. The effect of acetoacetate at 25 degrees C has ceased 90 sec after the start of the reaction. We propose a continuous flow method with relatively low concentrations of NaOH and picrate, and a kinetic method at 25 degrees C with a measuring time of between 90 and 270 sec after mixing sample and reagents. In this way the interference by acetoacetate and pyruvate is eliminated or reduced. We found excellent correlation between the proposed method for a centrifugal analyzer and a manual reference method, based on the adsorption of creatinine to fuller's earth.


Blood lead determination by flameless atomic absorption spectroscopy. A simple procedure for flameless atomic absorption analysis of lead in blood is described. It is based on the use of a temperature-controlled heating unit, which, with a photodiode, measures and, by electronic feedback, controls the temperature of the carbon rod. Examination of the influence of various heating has been made. Blood samples with heparin were diluted with Triton X-100, HNO3 added, and 2 microliter of the mixture analysed. Automatic background correction was used. Signals were evaluated by an electronic facility which gives integrated as well as peak height values. The method appears to be accurate and reproducible. The C.V. was, on average, 4%.


A rapid and specific method for the estimation of glucose using and oxygen electrode and simple differentiating circuit. A simple differentiating circuit is described which, together with an oxygen electrode assembly, provides a rapid (20 sec) and cheap system for the estimation of glucose in body fluids using a sample volume of 20 microliter. Response was linear over the range 0-22 mmol/l. The complete system has been evaluated using plasma and whole blood. "Within-day" precision on control plasmas over the concentration range 2.73-8.33 mmol/l lies between 2.0 and 3.3% (C.V., n = 23); "day-to-day" precision was 4.6% (C.V., n = 23). On whole blood, to which nitrate had been added, precision was 4.5% (C.V., n = 15); precision using standard glucose solutions was never greater than 3.3% (C.V., n = 15) over the concentration range 1.1-22.2 mmol/l. Recoveries of added glucose to plasma and whole blood were greater than 90%. Good correlation between glucose values obtained by the oxygen electrode system described here and an automated system were obtained for plasma (r = 0.9902, n = 35) and whole blood (r = 0.9610, n = 35), although whole blood gave values on average 27% lower than plasma. The use of the system for the measurement of plasma cholesterol is also demonstrated.


A new cause of increased serum aspartate aminotransferase activity. Two healthy young women had an unexplained persistent elevation of aspartate aminotransferase (ASAT) activity. In both cases electrophoresis of serum ASAT isoenzymes displayed an abnormally moving fraction that comprised the whole serum activity, while liver and muscle revealed the normal cytoplasmic and mitochondrial isoenzymes. In the first case serum ASAT was found to be bound by serum IgG, in the second case the binding protein remained unidentified.


Biochemical abnormalities in Dyggve-Melchior-Clausen syndrome. In continuation of previous studies, which showed a catabolic defect in proteoglycan metabolism, enzymes which degrade the proteoglycan macromolecules, e.g. proteinases (cathepsin D, elastase, and cathepsin G) and glycoisidases (arabinosidase and xylosidase) have been assayed in leucocytes of DMC patients. The regulator of lysosomal proteinases, cyclic AMP and serum antiproteinases, e.g. alpha1-AT and alpha2-M, have also been assayed. The proteinases assayed were normal in DMC patients. Arabinosidase activity in leucocytes of the patients was found to be decreased three fold, while xylosidase activity was increased three fold. A four-fold increased concentration of cyclic AMP in leucocytes of the patients and an increased serum concentration of alpha2-M associated with its abnormal pattern in crossed immunoelectrophoresis have been found. The abnormality in serum alpha2-M of DMC patients may be explained by a complex formation of alpha2-M with collagenase released from the lysosomes. Finally, an abnormal peptidoglycan has been demonstrated in DMC urine.


Identification of fatty acid methyl esters in kidneys and livers of two patients with Reye's syndrome. An unusual lipid, having an Rf value between that of cholesterol ester and of triglyceride on thin-layer chromatography, was clearly demonstrated in lipids from kidneys and livers of two Japenese children with Reye's syndrome. Gas chromatography-mass spectrometry revealed that the unusual lipid from viscera of the patients was a mixture of fatty acid methyl esters. Whether the occurrence of fatty acid methyl ester is the result of an inborn error of metabolism common to both patients, who were the progeny of consanguineous marriages, or whether it is a common biochemical feature in Reye's syndrome remains the subject of future studies.


Determination of disaccharides in feces by permethylation and gas chromatography: rapid screening for carbohydrate intolerance in children. Disaccharides can be identified and determined quantitatively in fecal specimens by permethylation of the components in crude supernatants followed by isothermal gas chromatographic separation on OV-17 columns. The method provides a rapid screening procedure for detecting patients suspected of having a carbohydrate intolerance secondary to intestinal disaccharidase deficiency.


The changes in activation of intracellular aspartate aminotransferase by pyridoxal 5-phosphate after cell death. Aspartate aminotransferase activity was measured in plasma, in liver and in heart mitochondrial and cytoplasmic preparations from rats immediately after death and after a post-mortem interval of 15 h. No significant stimulation of activity on addition of pyridoxal 5-phosphate to the assay medium could be demonstrated in any preparations obtained immediately after death. Significant stimulation occurred in both cytoplasmic and mitochondrial preparations of liver and myocardium after a 15-h post-mortem interval, but not in plasma stored for the same period. It appears, therefore, that variations in the intracellular saturation of apoenzyme with coenzyme cannot account for the observed differences in activation of aspartate aminotransferase by pyridoxal 5-phosphate in sera from patients with myocardial infarction and liver disease. Changes in degree of saturation of apoenzyme seem to occur intracellularly after cell death or injury and before release into the circulation.


Adsorption of heparin on sodium acid urate. The adsorption of heparin on sodium acid urate powder suspended in aqueous solution was found to be dependent upon the concentration of Ca2+ and Mg2+. It was concluded that heparin adsoprtion on sodium acid urate powder can occur in urine. Speculations are made about the relevance of these observations to calcium oxalate urolithiasis.


Hepatic lipase and lipoprotein lipase in postheparin plasma in liver disease. relations to plasma proteins. Hepatic lipase (HL) and lipoprotein lipase (LPL) in postheparin plasma have been studied in patients with different liver disorders and in a reference group. The dose of heparin (100 I.U./kg body weight) used intravenously to get maximal release of both HL and LPL was the same in patients and in healthy individuals. The release of HL was maximal in healthy controls after 2-5 min, but in patients with liver disease the maximum was not reached until 15 min after heparin administration. The time course of the release of LPL showed the same pattern in patients and controls. The activity of HL was below the lowest observation in the reference group in 8 out of 20 patients with liver diseases, and was not measurable in 3 of them (2 with chronic active hepatitis and 1 with alcoholic cirrhosis). The activity of hepatic lipase was positively correlated with the levels of coagulation factors and with the concentration of prealbumin in the total patient material. The results indicate that low activity of hepatic lipase is a sign of liver parenchymatous injury, and out study gives indirect evidence of the hepatic origin of this enzyme in man.


A survey of weighing performance in clinical biochemistry laboratories. Results of a survey of accuracy and precision of weighing in a sample of clinical biochemistry laboratories in the U.K. are reported. 101 laboratories each carried out eight weighings. 94% of weighings were subject to errors of not more than 1.7 mg at the 2 g level and not more than 1.0 mg at the 100 mg level. However, 9% of the laboratories produced results which were consistently subject to larger errors.


Plasma calcium and magnesium fractions in liver disease. Plasma calcium and magnesium fractions were measured in 51 patients with either hepatocellular or biliary disease. The fractions were found to be only minimally deranged. Plasma albumin correlated with total calcium and with the protein bound and ionized fractions. Abnormalities of plasma calcium or magnesium fractions are unlikely to play a role in the pathogenesis of the osteomalacia seen in chronic biliary disease.


The lower levels of erythrocyte surface electric charge in diabetes mellitus. Lower levels of surface electric charge and membrane N-acetylneuraminic acid of erythrocytes were found in patients with diabetes mellitus. These findings appear to be related to microvascular involvement.


A solubility problem in the preparation of uric acid standards. Consistently high (13-16%) uric acid values for quality control sera were found when using freshly-prepared working uric acid standards on the Autoanalyser II system. After investigation several conclusions are made, with the recommendation that working uric acid standards are best diluted with pH 9.5 glycine buffer (0.007 M).


Stability of the long chain non-esterified fatty acid pattern in plasma and blood during different storage conditions. A study has been carried out to determine the conditions under which plasma and blood can be stored without significant changes in the non-esterified fatty acid (NEFA) pattern and in the total NEFA concentration. From the results obtained it appears that: (1) blood can be stored for 2 h at room temperature and for 48 h at 4 degrees C. (2) plasma can be stored for 6 h at room temperature, 48 h at 4 degrees C and for at least 10 days at -20 degrees C under nitrogen without significant changes in the NEFA pattern and in the total NEFA concentration. The possible influence of heparin, used as anticoagulant, has been investigated. The results obtained are compared with those of other investigators.


5-Hydroxytryptophol in human cerebrospinal fluid: quantitative determination by gas chromatography-mass spectrometry using a deuterated internal standard. Procedures for the quantification of 5-hydroxyindole-3-ethanol, or 5-hydroxy-tryptophol (5-HTOL), in human cerebrospinal fluid are described. 5-HTOL was determined as its di-pentafluorpropionyl derivative. Deuterium labelled 5-hydroxyindole-3-ethanol-a,a,b,b-d4 (5-HTOL-d4) was used as internal standard. Mass fragmentography was performed by double ion monitoring each for 5-HTOL and 5-HTOL-d4 and their ratios were determined for specificity. Assay sensitivities of 0.15 ng/ml were achieved using 2.0 ml of cerebrospinal fluid. Free 5-HTOL concentrations in human cerebrospinal fluid were determined to be 0.73 +/- 0.44 ng/ml (mean +/- S.D.) (range 0.33-2.11 ng/ml) from 15 patients with various neurological disorders, and 0.85 +/- 0.30 ng/ml (range 0.48-1.32 ng/ml) from 9 subjects who complained of low back pain but did not show signs of neurological illnesses.


Gas chromatography of 5-hydroxy-3-methylindole in human urine. Electron capture gas chromatography was used to estimate the urinary 5-hydroxy-3-methylindole in epileptic patients and normal controls. The urine was filtered, concentrated in vacuo, extracted into benzene-ethanol and passed through a silica gel column. The dried eluate was dissolved in acetonitrile, tri-fluoroacetylated and estimated by gas chromatography as di-trifluoroacetylated 5-hydroxy-3-methylindole. This structure was confirmed by gas chromatography-mass spectrometry. 5-Hydroxy-3-methylindole was excreted at high concentrations in some epileptics and at low concentrations in normal control subjects.


Immune and non-immune T4 radioassays utilizing albumin magnetic microparticles. Albumin magnetic microparticles reversibly adsorb thyroxine. They quickly establish equilibrium allowing time and temperature independent measurements in T4 radioassays. We used these particles to compare the efficiency of NaOH, HCl, pepsin, sodium trichloroacetate, and 8-anilino-1-naphthalene sulfonic acid to release 125I-T4 from serum, T4-free serum and human serum albumin. We found that the efficiency of the reagents to extract 125I-T4 depended on the concentration and type of proteins to which the labelled hormone was bound. Pepsin was the most effective reagent and we utilized it for a T4 radioimmunoassay, in which albumin magnetic microparticles were used to separate free from bound hormone. We also utilized the particles in a T4 non-immune radioassay. Both assays accurately measured total serum T4, however the radioimmunoassay was simpler, less dependent on protein content of serum, required a smaller serum sample and provided slightly higher T4 values. We describe a magnetic rack which allows simultaneous handling of fifty individual tubes with an intra-assay C.V. of 2.1% for the radioimmunoassay and 2.3% for the non-immune assay and an inter-assay C.V. of 3.1%, respectively.


A novel fluorometric ultramicro determination of serum leucine aminopeptidase using a coumarine derivative. A simple and rapid rate assay of serum leucine aminopeptidase is described, using a novel fluorogenic substrate, 7-L-leucyl-4-methylcoumarinylamide. The reaction is initiated by adding 10 microliter of serum, and the fluorescence development for 1 min due to the 7-amino-4-methylcoumarin liberated at 37 degrees C is followed directly on a recorder. The proposed method is proved to be free from error due to the adsorption of the substrate dye to serum albumin and to be applicable to hyperbilirubinemic sera by simple correction. The values obtained by this method showed good correlation with those obtained by the conventional method of Goldbarg and Rutenberg (Goldbarg, J.A. and Rutenberg, A.M. (1958) Cancer 11, 283-291).


On standardizing the determination of the plasma renin activity. Basically, the determination of the plasma renin activity (PRA) consists of the in vitro generation of angiotensin I and the radioimmunological determination of angiotensin I. Since both steps can be performed in several ways, the results from different laboratories can hardly be compared. In this paper we have described the results of our attempts to standardize both steps of the PRA determination currently in use in our laboratory, against Research Standard A for Angiotensin I and the International Reference Preparation of Human Renin, both obtained from the Medical Research Council.


[Autonomic determination of proteins from urine by centrifugal and continuous flow analyses (author's transl)]. A precipitating reagent comprising partially neutralized trichloroacetic acid with magnesium sulfate, sodium dodecyl sulfate and polyethylene glycol is used for automatic determination of proteins from urine by centrifugal analysis and continuous flow analysis. We compare and discuss the results of both methods, their limits of validity and incorporation in an automated laboratory.