Fulminating arterial hypertension with pulmonary edema from release of adrenomedullary catecholamines after lesions of the anterior hypothalamus in the rat.

Bilateral electrolytic lesions of the anterior hypothalamus in unrestrained rats resulted in the development, within 2 hours, of arterial hypertension, tachycardia, hyperthermia, and increased locomotor activity, often leading to pulmonary edema and death. Similar lesions in paralyzed, artificially ventilated rats produced comparable changes in arterial blood pressure and body temperature with a similar time course. The arterial hypertension was a consequence of an increase in total peripheral resistance to 15% of control with a reduction in cardiac output to 49% of control. Arterial hypertension, elevated peripheral resistance, and diminished cardiac output were reversed toward normal by alpha-receptor blockade with phentolamine (1 mg/kg, iv). Bilateral adrenalectomy, adrenal demedullation, or adrenal denervation performed prior to lesion placement prevented the development of arterial hypertension and pulmonary edema as well as the changes in peripheral resistance, cardiac output, and body temperature. We conclude that arterial hypertension following lesions of the anterior hypothalamus is due to a neurally mediated increase in peripheral resistance initiated by the release of adrenal medullary catecholamines and that pulmonary edema is due to myocardial failure secondary to the ensuing ventricular overload. Structures originating in or passing through the anterior hypothalamus may exert selective control over the adrenal medulla independent of vasomotor neurons.


Reduced baroreflex sensitivity with volume loading in conscious dogs.

The Bainbridge reflex, i.e., the effect of rapid saline infusion (1.1 +/- 0.1 liters) on heart rate and arterial and atrial blood pressures, was examined in 12 intact conscious dogs; mean arterial blood pressure rose by 33 +/- 3 (SE) mm Hg, mean atrial pressure by 14 +/- 1 mm Hg, and heart rate by 75 +/- 9 beats/min. After beta-receptor blockade, heart rate rose slightly less (+49 +/- 5 beats/min, P = 0.05). Cholinergic blockade, combined cholinergic and beta-receptor, or beta-receptor blockade after vagotomy blocked the heart rate response to the infusion. The rise in heart rate in the face of an increase in arterial blood pressure with volume loading suggested that the arterial baroreceptor reflex was not responding appropriately to the increase in arterial blood pressure. In conscious dogs after denervation of the arterial baroreceptors, the increase in heart rate with volume loading was no greater than that in those dogs with their arterial baroreceptors intact, suggesting that the baroreceptor reflex was not restraining heart rate in the normal response to volume loading. The relationship between the pulse interval (PI) and the systolic arterial blood pressure (SAP) following an intravenous injection of methoxamine was used to evaluate the sensitivity of the baroreceptor reflex in intact conscious dogs. After a mild amount of volume loading, when atrial pressure was 8 +/- 2 mm Hg, the PI/SAP slope was significantly depressed from normal. When atrial pressure was elevated further to 28 +/- 1 mm Hg by volume loading, the slope was further depressed. Thus, arterial baroreflex sensitivity is reduced progressively as atrial pressure is raised by volume loading, an observation that explains how heart rate can rise strikingly in the face of an elevated arterial blood pressure.


Ventricular intramural and epicardial potential distributions during ventricular activation and repolarization in the intact dog.

Ventricular intramural and epicardial potential distributions were measured during normal excitation and repolarization in intact dogs. Potential distributions were chosen because they can be unambiguously measured, are useful in understanding the shapes of wave forms at many specific sites, and provide a direct measure of repolarization. Unipolar wave forms were recorded from intramural and epicardial electrodes and converted into potential distributions. Well-known shapes of wave forms recorded at the inner and outer layers of the ventricles as well as peak-to-peak voltages were shown by the potential distributions to be determined primarily by superposition effects of distant excitation waves. These effects were most prominent before epicardial breakthrough and then receded during the last half of the QRS complex. However, the potential distributions became more complex as excitation waves merged, collided, and terminated. During terminal depolarization, there were scattered positive repolarization potentials intramurally. Normal repolarization was characterized by positive potentials over the ventricular epicardium while there were changes intramurally and on the atrium. Throughout the T wave, there was a predominant transmural unidirectional gradient with the inner wall being more negative than the outer wall. This finding confirms that the sequence of repolarization is from the epicardium to the endocardium with the middle layers having an intermediate time.


Analysis of components in a cardiogenic hypertensive chemoreflex.

A cardiogenic hypertensive chemoreflex was studied in 38 anesthetized and three unanesthetized dogs. Serotonin (100 mug/ml) injected into either the left atrium or small brancehes of the proximal left coronary artery produced a maximal response, with 96 +/- 18 mm Hg increment in mean aortic pressure within 6 +/- 2 seconds, lasting about 1 min; a later phase of the same hypertension lasted 9 +/- 5 minutes more and could partially be produced with serotonin injected into the thoracic aorta. Injections into the distal left coronary artery produced only the Bezold-Jarisch reflex. Concomitant with the immediate hypertension there were vagal and sympathetic efferent effects in both the sinus node and the atrioventricular (A-V) junction. Either of these effects could be selectively eliminated and the other augmented by direct local perfusion with an appropriate cholinergic (atropine 10 mug/ml) or adrenergic beta-receptor (propranolol 10 mug/ml) blocking agent. Bilateral vagotomy markedly attenuated but did not eliminate the acute hypertension, but it abolished both chronotropic and dromotropic effects. Phentolamine (2 mg/min i.v.) markedly diminished the hypertensive response. Guanethidine or reserpine pretreatment markedly diminished the hypertensive response; reserpine eliminated the electrophsiologic effects but guanethidine did not. Infiltration of  serotonin around the main left coronary partially reproduced the reflex, but similar infiltration of xylocaine hydrochloride blocked the reflex. Serial section histologic studies of the region around the main left coronary atery in seven dog hearts and nine human hearts demonstrated the presence of a small structure resembling a chemoreceptor; its blood supply originated from the left coronary artery. Some possible clinical implications are discussed.


Coexistence of functional Kent and Mahaim-type tracts in the pre-excitation syndrome. Demonstration by catheter techniques and epicardial mapping.

An unusual patient with Ebstein's anomaly of the tricuspid valve and the Wolff-Parkinson-White syndrome is presented. Ventricular pre-excitation related to conduction over both a right posterior Kent bundle and Mahaim fibers coursing from the atrioventricular node to the right ventricle. Two types of supraventricular tachycardia were demonstrable. These were due to re-entry involving antegrade conduction over either the normal or Mahaim paths, and retrograde retrograde conduction via the Kent bundle. Surgical division of the Kent bundle has abolished the clinically debilitating arrhythmias.


The effects of ouabain on induction of atrioventricular nodal re-entrant paroxysmal supraventricular tachycardia.

Electrophysiological studies utilizing His bundle recordings and atrial extra-stimulus technique were performed in 17 patients (pts) with documented paroxysmal supraventricular tachycardia (PSVT) before and after 0.01 mg/kg, i.v., ouabain. Before ouabaine, echozones(EZ) were demonstrated in 11 patients. After ouabain, EZ were abolished in two, decreased in five, unchanged in three, and increased in one. In one patient, EZ was demonstrated only after ouabain. Eleven patients could sustain PSVT before ouabain; after ouabain, only six patients could sustain PSVT. Analysis of A1-A2, H1-H2 curves revealed 11 patients with discontinous (dual pathway) and six patients with smooth conduction curves. In dual pathway patients, both the fast and slow pathway curves were shifted rightward and upward after ouabain. The changes in EZ were dependent upon the relative rightward shifts of the two pathways. In patients with smooth curves, EZ tended to shift rightward with a critical A-H being achieved at longer A1-A2 intervals after ouabain. In conclusion, the effects of ouabain on PSVT were variable. Beneficial effects included abolition or decrease of EZ and loss of the ability to sustain PSVT. Potentially deleterious effects included widening or new de-elopment of EZ.


Sick sinus syndrome after surgery for congenital heart disease.

The course and prognosis of 16 infants and children with sick sinus syndrome associated with cardiac surgery is reviewed. The dysrhythmia was observed most ofter after extensive atrial reconstructive surgery in patients with transposition of the great arteries and with atrial septal defect. In 12 (75%) of the patients, sick sinus syndrome was detected in the immediate postoperative period. Tachyarrhythmias and bradyarrhythmias were presnet in 12 and isolated bradyarrhythmias in four. Temporary pacing was used in two and permanent pacing was required in five. Death in two non-paced patients was attributable to arrhythmias. Postmortem examination in one patient revealed a suture in the sinoatrial node. Careful attention to the anatomy of the sinoatrial node, its artery and the internodal tracts during surgery may prevent the development of sick sinus syndrome. In patients with dysrhythmia, a careful search should be undertaken to document the abnormal rhythm with the use of Holter monitoring. The insertion of a pacemaker is indicated in patients with tachyarrhythmias requiring cardioversion or antiarrhythmic drug therapy and those without adequate lower escape mechanisms.


Sinus node function and conduction system after complete repair of tetralogy of Fallot.

Twenty-three children underwent electrophysiological studies during routine postoperative catheterization two months to five years after complete correction of tetralogy of Fallot. The aim of the study was to investigate the whole conduction system, including sinus node function, suing His bundle recordings and atrial pacing. H-V intervals were normal at rest and with pacing in twenty-two patients, including four patients with evidence of bifascicular block on the surface ECG. One patient with cardiomegaly and evidence of diffuse myocardial damage had a prolonged H-V interval but did not develop a block at this level during pacing A-H interval was slightly prolonged in four patients and normal in all others. The threshold of pacing-induced atrioventricular block ranged from 75 to 240/min and was somewhat age dependent (r = -0.55). Two patients fell below the 95% confidence limit of this regression and are considered abnormal. One returned to normal after intravenous injectionof atropine. Corrected sinus node recovery time ranged from 60 to 2000 msec. Three patients had values above 500 msec which are considered abnormal. These patients had other minor signs of sinus node dysfunction, i.e., episodes of sino-atrial block at rest or intermittent sinus bradycardia. Thus, while the His Purkinje system performed satisfactorily in all patients, sinus node dysfunctional and A-V node dysfunction were demonstrated in a few patients after correction of tetralogy of Fallot.


Mitral valve prolapse and coronary artery disease. Clinical, hemodynamic, and angiographic correlations.

Among 95 patients with angina pectoris and angiographically documented coronary artery disease (CAD), prolapse of the scallops of the posterior leaflet of the mitral valve (PLMV) was noted in 30 patients. Left ventriculograms in the right anterior oblique (RAO) projection revealed isolated prolapse of the posteromedial commissural scallop (PMCS) in 12 patients and the anterolateral commissural scallop (ALCS) in two patients. Seven patients had prolapse of both PMCS and ALCS, three had prolapse of the PMCS and middle scallop (MS), and six had prolapse of all three scallops of the PLMV. Left ventricular dilatation with increase trabeculations was observed in 19 patients. Contractility determined in a quantitative fashion by segmental motion analysis was markedly impaired in 29 patients. None of the patients had angiographic evidence of mitral insufficiency. Left ventricular dysfunction was documented in 28 patients by either elevated left ventricular end-diastolic pressure (LVEDP), low cardiac index (CI) or decreased ejection fraction (EF). In two patients in whom left ventricular contractility improved after aortocoronary by pass, previously prolapsed scallops could not be identified in the postoperative ventriculogram. Prolapsed PLMV is a frequent angiographic finding in patients with angiographically observed CAD. Impaired contractility of the ventricular myocardium and papillary muscles, left ventricular dilatation, and hypertrophy appear to play a significant role in the pathogenesis of this abnormality through distortion of the directional axis of the papillary muscles, asynergic contraction of the related free wall of the left ventricle, and changes in the normal spatial alignment necessary for mitral valve closure. The syndrome of papillary muscle dysfunction in patients with coronary artery disease represents a wider clinical spectrom than previously described.


Three dimensional geometry of acutely ischemic myocardium.

The distribution of coronary flow to small segments of the entire left ventricle (96 per dog; average weight = 0.78 g) was studied in 28 open-chested dogs utilizing 7-10 mu labeled microspheres. Although the flow to large areas of the ventricle was nearly evenly distributed, there was considerable heterogeneity of flow to small adjacent segments of myocardium (average standard deviation of the flow distributions was 17.3 +/- 3.2% of mean lfow). Approximately one-half of the measured heterogeneity of flow could be attributed to various extraneous factors, and one-half appears to be due to inherent heterogeneity of flow in the left ventricular myocardium. In ten of 28 dogs, the mid-circumglex coronary was suddenly occluded, and five minutes thereafter the distribution of left ventricular flow was determined with microspheres labeled with a different isotope. The ischemic regments were separated into three groups: severely ischemic, moderately ischemic, and borderline ischemic. The three dimmensional geometry of the acutely ischemic myocardium was analyzed, and four general conclusions were reached. 1) The percent distribution of severely ischemic segments, moderately ischemic segments, and borderline ischemic segments within an ischemic region varies from animal to animal. 2) Subendocardial segments were more frequently and more severely affected than neighboring mid-wall or epicardial segments. 3) No evidence of an "hyperperfused zone" of myocardium surrounding the ischemic area was found. 4) The flows to segments immediately adjacent to the severely ischemic segments were heterogeneous. Therefore, the concept of a geometrically defined "buffer zone" of moderately ischemic myocardium surrounding and separating severely ischemic from normally perfused myocardium no longer seems realistic.


Comparison of ejection fraction and zonal mean velocity of myocardial fiber shortening.

To determine the extent of cardiac involvement until a diminished ejection fraction (EF) is present, zonal mean velocity of circumferential fiber shortening (Vcf) was measured from the left ventriculogram in 36 patients. The longitudinal axis (apex to mid-point of the aortic valve plane) in right anterior oblique view was divided into four equal parts by three perpeendicular chords. Zonal Vct and percent shortening along the proximal, middle and distal chords were measured. The results of this study indicate that a normal EF is frequently associated with a reduced Vct in one or even two zones. A reduced EF is generally accompanied by a diminished Vct in all three zones of the heart. In addition, a close correlation was found between zonal Vct and percent shortening. Hence the latter, which is much simpler to measure, can be instead of Vct Ejection fraction as a measure of myocardial performance is not as sensitive as Vct, especially in hearts with asynchrony of contraction.


Appraisal of sinus node artery disease.

The relationship of depressed sinus node function to coronary artery disease (CAD) was evaluated. The sinus node artery (SNA) was easily identified in all of 80 unselected normal coronary arteriograms. Angiographic disease of, or significant obstruction proximal to, the SNA was seen in 21% of 80 unselected CAD patients. Heart rate and sinoatrial recovery times (SART) were obtained in 50 consecutive unmedicated patients prior to arteriography. There was no difference between the SART of 23 CAD patients free of SNA involvement (1092 msec +/- 55 sem) and 18 normals (1070 +/- 40 msec). Nine patients with SNA involvement had shorter SART (941 +/- 52 MSEC) than normals (P less than 0.05) or other CAD patients (NS). Similar results were obtained for heart rate. No patient with SNA involvement had a prolonged SART or sick sinus syndrom (SSS). six of the 50 patients studied were symptomatic with SSS. Five of these SSS patients had CAD but none had angiographic evidence of SNA involvement. Obstructions involving the SNA were common in CAD but were not associated with altered heart rate or SART. Patients with SSS exhibited no angiographic evidence of SNA involvement. Therefore, it is unlikely that SSS is related to CAD of the SNA.


Reversal of dominance of the coronary arterial system in isolated aortic stenosis and bicuspid aortic valve.

The dominance of the coronary arterial system was determined angiographically in 75 adult patients with isolated aortic stenosis with or without insufficiency, 25 adult patients with pure aortic insufficiency, 51 adult patients with combined aortic stenosis and mitral valve disease, and 44 children with bicuspid aortic valves. There was an unusually high incidence of left dominance in adults with isolated aortic stenosis (36%) and in children with bicuspid aortic valves (56.8%). These findings suggest the existence of a variant developmental complex consisting of a bicuspid aortic valve and reversal of dominance of the coronary arterial system. Furthermore, it adds support to the concept that progressive stenosis of a bicuspid aortic valve is frequently the etiology of isolated aortic stenosis in adults.


The pathophysiology of idiopathic mitral valve prolapse.

Left ventricular structure, function, and the coronary circulation were studied in a subset of patients with mitral valve leaflet prolapse. This group of 26 patients (21 females, five males, with mean age of 46 years), had the syndrome identified as idiopathic mitral valve prolapse (IMVP), which was characterized by a systolic click-murmur, clinical symptoms that were highly variable in duration and intensity, angiographically-documented mitral prolapse, and no obvious associated systemic or cardiovascular disease. Mitral regurgitation was of moderate degree in four, mild in 14, and absent in eight. The left ventricular (LV) end-diastolic volume index was elevated in ten of 25 (40%), the LV mass index was elevated in six of 17 (35%), but the LV anterior wall thickness was increase in only one of 17. Three major patterns of ventricular contraction were identified: 1) normal in seven; 2) abnormal, usually an inferior deformity and/or anterior asynergy, in eight; and 3) hyperkinetic in 11. Normal resting left ventricular function, assessed as an ejection fraction greater than 55%, was present in 17 of 25 (68%). Selective coronary arteriography was essentially normal in all 25 patients studied. An ischemic ECG response was detected during only one of 12 maximal treadmill exercise tests and in none of ten atrial pacing stress tests (AP). Myocardial lactate extraction did not change significantly during AP in six patients. We conclude that cardiomyopathy does not appear to be a primary cause or an important associated component of the IMVP syndrome. Abnormalities of the coronary circulation or of myocardial metabolism were not demonstrated by available methods. A proposed pathophysiological mechanism to explain the clinical and angiographic findings in IMVP is discussed.


Studies of the absorption and removal of propranolol in hypertensive patients during therapy.

The variability of plasma propranolol concentrations has been determined in a large group of patients being treated with the drug. Although the average patient achieved a therapeutic plasma level with 160 mg/day, there was marked interpatient variation. This was found to be primarily the result of differences in effective absorption of the drug, which averaged 46% of the oral dose but ranged from 20 to 80%. Propranolol disappeared from plasma with a half-life of 4.7 hours and its removal appeared to follow dose independent kinetics with no evidence of saturation of hepatic metabolism. The derived pharmacokinetic values of volume of distribution and clearance rate have been used to provide guidelines for initiating propranolol therapy intravenously, and the schedule of 8 mg as a loading dose and 0.02 mg/min as a sustaining dose has been suggested.


Carbohydrate metabolism in the chronically uremic rat.

The sub-totally nephrectomized chronically uremic rat has been found to have significantly increased hepatic glucose-6-phosphate dehydrogenase activity and increased lipogenesis and glycoportein synthesis. Increased conversion of 14-C-D-glucose to 14-CO2, and increased plasma free fatty acid levels were also observed. The metabolic significance of these findings has been discussed, particularly with respect to the importance of the pentose shunt in this model. The influence of reduced diet intake, resulting from uremic anorexia, has been considered in light of changes observed. It is concluded that decreased food intake alone is unlikely to be responsible for the altered glucose utilization evident in this model.


Improved method for euglobulin clot lysis time.

1. The use of Evans Blue dye to facilitate endpoint determination the elimination of 4 degrees, assay conditions are technical improvements in the euglobulin clot lysis test. 2. Plasma samples have limited stability at 30 degrees or 4 degrees, but are stable for prolonged periods at minus 20 degrees. Samples with accelerated clot lysis are much less stable than normal samples at 30 degrees. 3. The normal range is determined as greater than 70 minutes for citrated plasma and greater than 50 minutes for oxalated plasma. There is no sex difference in the normal range.


Serum arginino-succinate lyase: observations on the sensitivity and specificity of this test in the detection of minimal hepatocellular damage.

The serum argino-succinate lyase (ASAL) activity was measured in preoperative and post-operative serum samples, from approximately 500 patients submitted to elective surgery. The results were compared with the determinations of 6 other enzyme activities on the same serum specimens. Serum ASAL elevations correlated highly with increases in serum alanine aminotransferase (ALT) activity, and were nearly twice as great. They also correlated well with serum aspartate aminotransferase (AST), but were approximately 2.7 times greater. It is confirmed that the serum ASAL activity is a sensitive and specific test for liver cell damage, suitable use in special conditions where high sensitivity is required.


Applications of a Vidicon spectrometer to analytical problems in clinical chemistry.

This report discusses characteristics of a custom-designed vidicon spectrometer and evaluates its applicability to several clinical analysis problems. Data show that the vidicon detector response is linear with intensity over about four orders of magnitude and that the uncertainty in absorbance measurements can approach 0.001 absorbance units in the range from 0 to 2 absorbance units. Applications include the enzymatic determination of glucose, the determination of lactate dehydrogenase, and determinations of barbital, chlordiazepoxide, and glutethimide. Capabilities of the instrument system for first-derivative spectroscopy are also discussed. The discussion included a critical evaluation of the potential advantages and limitations of the concept.


Improved measurement of erythrocyte volume distribution by aperture-counter signal analysis.

In aperture counters, particles in fluid suspension flow through a small orifice or aperture, causing a change in the electrical resistance of the aperture. This change is sensed by an external electronic circuit and translated into a voltage pulse, the signal height of which is proportional to the volume of the particle in the aperture. These signal pulses are collated into a spectrum of pulse heights by a multichannel pulse-height analyzer. The channel number (voltage increment) spectrum is proportional to the volume distribution of the particles sensed. A problem is that pulse height not only depends on cell volume, but also on the orientation and shape of the particle sensed and the current density along the path taken by the particle through the aperture. Uneven current density exists, primarily at the aperture entrance and exit, close to the wall. Orientation and shape of particles are altered near the wall by the unbalanced shear forces there. Toward the center of the aperture, the shear forces act so as not to induce continuous change in the orientation of the particles sensed. Thus introduction into the pulse-height spectrum of pulses that do not show a good proportionality to volume is primarily caused by particles that are traveling near the aperture wall. Residence time in the aperture for a particle traveling near the wall will be longer than that for a particle traveling down the center of the aperture, because of the smaller fluid velocity near the wall. Duration of the signal pulse created by a particle traveling near the wall will be correspondingly greater. We discuss an electronic filter to remove from the pulse-height spectrum those pulses that appear to result from particles traveling near the wall and the effect  of the filter on the measured signal height and hence the volume distribution of erythrocytes. Use of this technique to characterize erythrocytes by volume distribution is described.


Continuous monitoring of radioactivity of effluent from a high-speed amino acid analyzer, with a new system of sample segmentation.

Radioactivity in the effluents from high-speed liquid chromatographic analyzers was continuously measured by use of a new sample segmentation system. To achieve highest counting efficiency, the column effluents were mixed with scintillation fluid carrying small segments of semisolid, resillient spacer. After passing through a mixer, the mixture was passed through a hollow-tube flow cell mounted in a liquid scintillation spectrometer. Because the added spacer acts like a continuous series of pistons, it unifies flow rate at center and walls of the conduit and so decreases sample carryover. This system was applied to measurement of radioactivity in the effluent of a high-speed amino acid analyzer, in which some amino acids emerge at 30-s intervals. The resulting profiles were as well resolved as were the ninhydrin-color profiles. Counting efficiencies for tritium and carbon- 14 were comparable to those obtained by static counting in vials.


Automated elution electrophoresis: a potential clinical tool.

An elution electrophoresis system in which a porous packed bed is used for separation and a flow photometer or colorimeter for continuous monitoring of the eluate may be capable of rapid, high-resolution analysis of serum proteins and other protein mixtures with very little manual labor. In a prototype of such a system we used a cooled separations column, 3 mm in diameter and 40 cm long, containing polyacrylamide beads. Samples are introduced, via a microsyringe, through a septum at the column midpoint. Typical analyses for serum proteins or serum isoenzymes require an electrophoresis time of about 30 min at 1200 V.


Computer interface for data acquisition and control of an SMA 12/60.

We present an approach to the computer enhancement of the "SMA 12/60" (Technicon Instruments Corp.). Practical and theoretical considerations led to a plug-compatible system, which did not require changes in the hydraulics or methodology of the SMA. Results obtained from eight channels of the SMA using the system as described show that a sample analysis rate of 120 per hour is feasible. A desirable consequence of the increased analysis rate is a 60% decrease in the required sample volume. Before the system can be used in a clinical environment, further development will be necessary, including detection algorithms for hydraulic malfunction.


Development of a multipurpose optical system for use with a centrifugal fast analyzer.

A Centrifugal Fast Analyzer is basically a sophisticated photometric measuring device containing a multicuvet rotor as its major component. Several reactions are simultaneously initiated in the rotor, which is then rotated through a stationary optical monitor and the resulting signals acquired and processed by an on-line data system. ?With the miniature version of this analyzer, one has the option of directing the incident optical beam, via a fiber optical bundle, into the cuvets of the spinning rotor in either a 90 degrees or a 180 degrees orientation relative to the analyzer's photodetector. tthe combination of newly designed rotors and a flexible optical system having multiple configurations has provided a versatile system in which one can measure the transmittance, fluorescence, chemiluminescence, or light-scattering (either turbidimetrically or nephelometrically) properties of the ensuing reaction species, all with a single analyzer. This flexibility in choosing the optical mode in which a particular set of reactions is to be monitored provides the analyst with a powerful and versatile analytical tool for developing new methods for use in various clinical laboratory applications, including chemistry, toxicology, immunology, and hematology.


Stable isotope ratiometer-multiple ion detector unit for quantitative and qualitative stable isotope studies by gas chromatography-mass spectrometry.

We have designed and constructed a stable isotope ratiometer-multiple ion detector unit, which can drive existing chromatograph-quadrupole or magnetic sector mass gas spectrometers to monitor up to six ions in turn. Each of the three pairs of ions can be selected for quantitation; thus three different or successive components can be analyzed in a single gas-chromatographic run. A background subtraction option permits the ion intensity in the absence of sample to be subtracted automatically during sample measurement. Displays of accumulated counts and isotope ratio are updated twice per second during the measurement and can be printed out at is conclusion. All six ions can be monitored in the analog mode by parallel outputs to a multipen recorder. Experience gained in the construction of this prototype indicates that such units could be commercially available for $10 000, or about a third to a sixth of the cost of even an inexpensive computer system.


Making enzymatic methods optimum for measuring compounds with a kinetic analyzer.

Kinetic enzymatic methods for analysis of substrates can be made optimum for a sensitive photometric analyzer by adjusting the activity of the triggering (catalyzing) enzyme so that the reaction rate is maximum at the time of measurement. tat this optimum activity, the exponential time constant for exhaustion of substrate equals the time between triggering and rate measurement. The scale factor (defined as measured activity divided by sample concentration in the reaction mixture) is the same for all tests. Sensitivity to substrate concentration is predictable from instrumental absorbance uncertainty and molar absorptivity of the absorbing species. These predictions from Michaelis theory were verified experimentally for pyruvate and lactate triggered with lactate dehydrogenase, for glucose triggered with hexokinase, and for triglycerides triggered with glycerol kinase, the reaction rate being measured 30 s after triggering. Sensitivities of 1.5 times 10(-7) mol/liter were achieved. Serum diluted 1000-fold and analyzed for glucose gave a repeatability of 25 mg/liter with linearity to 4.0 g/liter. Samples diluted 300-fold and analyzed for triglycerides gave 30 mg/liter repeatability, with linearity to concentrations exceeding 3.0 g/liter.


Computerized multicuvette system for single substance and group analysis and for the chromatographic isolation and quantitation of compounds in complex mixtures.

A new computer-interfaced system of general applicability in the clinical laboratory has been built. The system is constructed around a new type multicuvette. Quantitation is currently by spectrophotometry and is on-line, with use of a mini-computer with output going to an electrostatic printer/plotter. The system can be used for single-substance batch analyses, for group analyses, and for the estimation of profiles of compounds after preliminary high-resolution liquid chromatography tailored to interface with the multicuvette.


New instrument for rapid determination of activities of lactate dehydrogenase isoenzymes.

Lactate dehydrogenase isoenzymes can be distinguished kinetically by the fact that isoenzyme H is strongly inhibited a few seconds after the reaction is started if high concentrations of pyruvate are present, in contrast to the M isoenzyme. A new instrument that exploits this fact can measure both the total activity and the proportion of H isoenzyme in serum or plasma in 8 to 10 s. The instrument consists of a simplified stopped-flow apparatus in which the plasma is assayed for lactate dehydrogenase activity, and an electronic device that measures the rate of the reaction at two pre-set time intervals. The first rate is taken between 0.2 and 0.4 s after the reaction is started, a time at which both isoenzymes are fully active, and at which the rate obtained thus reflects total lactate dehydrogenase activity in the plasma sample. The second rate is measured 4 to 6 s after the start of the reaction, at which time the H isoenzyme has become inhibited and the observed rate compared to the initial rate is therefore proportional to the percentage of H isoenzyme activity in the serum. These two rates are electronically displayed on two three-digit voltmeters, the first display being the total activity, the second a number proportional to the inhibited slope. The percentage of M isoenzyme can then be calculated from the initial and final rate. A total of five to six repeat assays may be done within a minute on 1 ml of plasma or serum. This instrument may be of significant value in following the progress of myocardial infarctions and other diseases.


Clinical applications of gas chromatograph/mass spectrometer/computer systems.

Gas chromatograph/mass spectrometer/computer systems can be used to quantify a wide variety of compounds of clinical interest. A quadrupole instrument operated in the chemical ionization (Cl) mode was used in these studies. Because of the sensitivity and specificity of selective ion detection, it is possible to make measurements routinely in the nanogram to picogram range, with 0.1-1.0 ml samples of plasma and 1-5 ml samples or urine. Internal standards, preferably stable-isotope-labeled compounds, were added to the biological samples before isolation was begun. We describe clinical applications of these procedures to problems in toxicology, pharmacokinetics, and perinatal pharmacology.


Coagulation-time determination with automatic multivariable analysis, by use of a miniature centrifugal fast analyzer.

Use of a miniature Centrifugal Fast Analyzer for the parallel photometric monitoring of the coagulation process is shown to have a number of advantages. These include a choice of optical modes, virtually simultaneous initiation and observation of the coagulation process for a number of patient-plasma samples and an on-board control sample, small sample and reagent volume requirements, and automatic determination of a number of diagnostically useful variables (including relative fibrinogen content) from the data recorded in a single run. Also, the system is shown to give results that correlate well with those obtained by conventional techniques for determination of prothrombin time.


Gas-chromatographic and mass-spectrometric detection of low-molecular-weight aliphatic alcohols in urine of normal individuals and patients with diabetes mellitus.

We studied the aliphatic alcohols in 100 urines from 25 patients with diabetes mellitus under treatment with insulin, oral antidiabetic medication, or special diet. The procedure involves adsorption of the low-molecular-weight urinary metabolites on a porous polymer of 2,6-diphenyl-p-phenylene oxide (Tenax GC), gas-chromatographic separation, mass spectrometric identification, and mass fragmentographic representation of the primary alcohols by a computer. The concentrations of ethanol, n-propanol, isobutanol, n-butanol, and isopentanol are increased as compared with urine from normal persons.


A flow-system multiangle light-scattering instrument for cell characterization.

A flow-system cell-analysis instrument is described in which cells from a heterogeneous population are characterized by their light-scatter patterns alone. As the cells pass at high speed through a focused helium/neon laser beam, the scatter pattern from each cell is sampled simultaneously at up to 32 angles between 0 degrees and 30 degrees with respect to the laser beam axis, and the scatter pattern for each cell is transferred to a computer. A mathematical clustering algorithm is used to determine the number of classes into which the cells can be divided, and a linear separation algorithm is used to find the boundaries between the classes. Preliminary results on exfoliated cells from gynecological specimens are presented. This technique may be useful for automated prescreening of gynecological specimens.


Liquid-chromatographic analysis for neutral carbohydrates in serum glycoproteins.

We describe a sensitive, reproducible procedure of analysis for the six neutral carbohydrates in glycoproteins, by high-resolution anion-exchange chromatography. As many as 16 neutral carbohydrates can be separated by elution with a concentration gradient of boric acid (pH 7, 67 to 672 mmol/liter). The carbohydrates are detected with a cerate oxidimetric detector system, which monitors the fluorescence of Ce3+ produced by the reaction of the eluted constituents with Ce4+. Sensitivity to 1 nmol of fucose is demonstrated. Analytical methods and results are presented for mannose, fucose, and galactose in serum glycoproteins for both normal women and those with metastatic breast cancer. We briefly discuss the possibility of separating and analyzing for the three neutral carbohydrates in serum glycoproteins in 4 h by isocratic (constant eluent concentration) elution from a chromatographic column.


Identification of some abnormal metabolites in plasma from uremic subjects.

We describe a method for comparing plasma samples from healthy subjects and from chronic uremic patients before and after dialysis. It was used to determine the nature of those metabolites that appear to characterize the uremic state. Preliminary fractionation of the metabolites by gel chromatography was followed by removal of the aqueous effluent by lyophilization and preparation of volatile trimethylsilyl derivatives, which were then examined by gas-liquid chromatography. Gas-liquid chromatography/mass spectrometry was used to characterize and identify individual metabolites. Gas-liquid chromatographic patterns of plasma from healthy and uremic subjects differ markedly, more so than do individual plasma samples within the same class of subjects. Concentrations of many metabolites are increased in uremia, but after dialysis of the patient's blood, the concentrations become about the same as those in healthy plasma. We have observed some 150-200 metabolites in each category of plasma. We have tentatively identified about a tenth of the compounds that appear to be specific to or increased in uremia, including lactic acid, glycerol, erythritol, erythronic acid, 2-deoxy erythro pentonic acid, arabinitolarabinonic acid, inositol, and lactose. Some of these are present in concentrations greater than 20 mg/liter and have not been previously reported as occurring in the uremic state.


A rapid gas chromatographic method for the quantitation of underivatised individual free fatty acids in plasma.

A rapid method for quantitating individual free fatty acids (FFA) in plasma has been developed. An internal standard is added to plasma, the FFA are extracted into an organic solvent, concentrated and injected into a gas chromatograph. For routine estimations, extraction and assay of a single sample takes about 30 min and up to 30 samples can be assayed in a day. Seven FFA (myristic, palmitic, palmitoleic, stearic, oleic, linoleic and linolenic acids), are routinely quantitated. This method can be used to monitor individual FFA levels, to determine the percentage composition of individual FFA in plasma or to investigate metabolic disorders involving fatty acids, for example Refsum's disease.


Linearity and accuracy of ultraviolet and visible wavelength photometer: an interlaboratory survey.

A survey was made to determine the linearity and accuracy of ultraviolet and visible wavelength photometers used by laboratories in New York State. Two solutions each of high-purity potassium dichromate and cobalt ammonium sulfate were submitted for photometric performance studies. The majority of the participant spectrophotometer results showed good correlation with reference data. Broad half-band width (greater than 10 nm) photometers showed little deviation from linearity. Coefficients of variation for the models surveyed were 5-10%.


Alkaline phosphatase isoenzymes of human kidney and urine.

Kidney and urinary alkaline phosphatases have been studied by starch gel electrophoresis. Kidney extracts have shown individual variations and the patterns obtained with cortex and medulla have been clearly different. There are in urine and kidney extracts, phosphatases which share similar properties with regard to electrophoretic mobility, non-susceptibility to treatment with neuraminidase and inhibition by L-phenylalanine.


A simplified heat-inactivation method for investigating alkaline phosphatase isoenzymes in serum.

A method is described for the determination of the percentage of liver alkaline phosphatase in serum samples in which measurements of residual activity are made after incubating the samples for 15 and 25 min at 56 degrees C. This method has the advantage of taking into account quantitative variations in the heat stability characteristics of liver alkaline phosphatase from one sample to another, in contrast to methods in which only a single period of exposure to 56 degrees C is employed.


Monoamine metabolites and related compounds in human amniotic fluid: assay by gas chromatography and gas chromatography-mass spectrometry.

Some catecholamine metabolites and related compounds have been identified in amniotic fluid obtained by transabdominal amniocentesis at various stages of pregnancy, including 4-hydroxy-3-methoxymandelic acid, 4-hydroxy-3-methoxyphenylglycol, 4-hydroxy-3-methoxyphenylcetic acid, p-hydroxypheny lacetic acid, p-hydroxphenyllactic acid and N-benzoylglycine (hippuric acid). Analysis was by gas chromatography with electron capture detection and by gas chromatography-mass spectrometry. Two of these compounds were determined quantitatively, free 4-hydroxy-3-methoxphenylglycol and p-hydroxyphenllactic acid: the concentration of the former increased with advancing pregnancy and that of the latter tended to decrease. Conjugated 4-hydoxy-3-methoxyphenylglycol could not be determined with accuracy as appreciable amounts of the unconjugated compound were found in the snail extract used for enzymatic hydrolysis. Assay of 4-hydroxy-3-methoxyphenylglycol in amniotic fluid is likely to be of diagnostic importance in the prenatal diagnosis of congenital neuroblastoma. Although 4-hydroxy-3-methoxyphenylethanol, 3, 4-dihydroxymandelic acid and 3, 4-dihydroxyphenylacetic acid were specifically looked for in amniotic fluid, they could not be detected.


Estimation of seric and parietal inhibiting power of elastase; its changes with experimental conditions.

The existence of a parietal elastase and its physiological role in the pathology of the arterial wall remain unknown: it is probably difficult to demonstrate its specific activity because of existing tissular inhibitors, homologus to seric inhibitors. The change of seric inhibitor power when elastase is injected to animals with or without a cholesterol diet is discussed. Moreover, an aortic inhibiting power against elastase is shown. Our results emphasize some new aspects of elastase in its role in arterial wall pathology.


A new radioimmunoassay for demonstrating the antibody to hepatitis-B-surface-antigen(HBs-Ag).

A new radioimmunological system for demonstrating the antibody to hepatitis-B-surface-antigen (HBS-Ag) based on the immunoadsorption principle is described. The optimal conditions for the test are given. False-negative and false-positive results could be excluded by specificity tests on sera from 100 voluntary blood donors. The sensitivity of the system is comparable to that of other more expensive radioimmunological methods.


Relative competition of corticosterone, cortisol, cortisone, 11-dexycortisol and prednisolone with (1,2-3H)-cortisol in various protein-binding radioassay systems.

The relative influence of some endogenous corticosteroids and of synthetic prednisolone on competitive protein-binding radioassay was compared with that of cortisol, using as a source of transcortin pooled plasmas from various species and at different dilutions. Human (different clinical situations), cow, dog, sheep, hog, rabbit and chicken plasma were examined. The ability of corticosterone, cortisone, 11-deoxycortisol and prednisolone to displace [1,2-3-H] cortisol from corticosteroid-binding globulin (CBG) was measured: (1) by assessing the amounts (ng/tube) which produce a displacement equal to 10 ng/tube of cortisol, and (2) by calculating the integrated areas of displacement defined by the binding curves and by expressing them as a percentage of the cortisol curve area. While corticosterone, 11-deoxycortisol and prednisolone have a binding potency not very different from that of cortisol in almost the entire set of competitive protein-binding assays tested, the binding ability of cortisone was found to be particularly dependent upon the species of diluted plasma. Differences in the relative specificity of binding are apparent also within the human species, depending on the source of diluted plasma, whereas the concentration of endogenous steroids does not seem to significantly affect binding curves under the conditions examined. It is suggested that binding proteins in various conditions differ from those of healthy adults not only quantitatively but also qualitatively.


[Blood serum levels of immunoglobulins among African children: Seasonal variations and ethnic factors (a study done in Lourenco-Marques among a group of 11-year olds) (author's transl)].

The blood titers of IgG, IgA and IgM and total proteins were determined in October 1971 (dry season) and again in April 1972 (wet season) among girls and boys belonging to 4 ethnic groups: White, Bantu, Indian, Mixed. Parasitic studies were also done. These studies indicate a rise of IgM among the girls and of IgA in both sexes from October 1971 to April 1972. The average IgM titer among the four groups is higher than the one found in the Occident. This is especially notable for the Bantu and the Mixed. The Indian levels exceeded, on the average, the White group's. The average IgG figures are only slightly higher than those found in the literature for Western populations. Genetic influences do not appear to explain the differences found between the ethnic groups. The role of environment is stressed, and parasitic influences are discussed.


The development and evaluation of a semi-automated assay for catecholamines suitable for plasma and urine.

A simple semi-automated procedure for assay of catecholamines in plasma and urine is described. Each step is examined and the end product is the culmination of these investigations. Use is made of batch alumina adsorption and elution, after comparison with column methods had shown no real advantage. Urine estimations included a preliminary ion-exchange column step. The estimation is such that 40 to 50 specimens of plasma or 60 to 70 specimens of urine can be assayed in a day by a trained laboratory technician. The method is both specific and reproducible, and the sensitivity is increased over previously reported methods. Interference by other catecholamines and compounds is examined and discussed, as are alternative stabilising agents and reactions for the rearrangement and stabilisation of the fluorescent compounds in strong alkali.


The reliability of the measurement of plasma renin activity by radioimmunoassay.

A radioimmunoassay of angiotensin I has been applied to the measurement of plasma renin activity. Angiotensin I was generated in plasma samples by 3 h incubation at 37 degrees C and pH 5.6 after addition of EDTA and Dowex. The generated amount of angiotensin I was measured by radioimmunoassay in the eluate of the Dowex column. With this method a negligible amount of angiotensin I was measured after incubation at 4 degrees C (0.8 ng/ml per 3 h). Eluate of blank plasma had no measurable effect on the standard curve. The mean recovery of angiotensin I was 87%. The limit of detection of the assay was 0.5 ng/ml per 3 h. The results obtained using different antisera were equal. A marked variation was found in immunological properties of different standard preparations of angiotensin I tested. The mean value of angiotensin I generation per Goldblatt Unit (G.U.) renin was 3.9 with 10-4 ng/h. In normotensive control subjects, the plasma renin concentration, whileon unrestricted diet and after 3 h of ambulation, was on average 0.39 with 10-minus 4 G.U./ml, range 0.12 with 10-minus 4-0.91 with 10-minus 4. With the use of the same plasma extracts for radioimmunoassay and bioassay, a perfect correlation was found between the plasma renin activities measured with both assays. The differences found between the results of both assays could be fully explained by the different biological activities of the standards used (Angiotensin I, Schwarz Mann, and Angiotensin II, Ciba-Geigy). With a direct radioimmunoassay, angiotensin I was generated in plasma by 3 h incubation at 37 degrees C and pH 5.6 after addition of phenylmethanesulfonyl fluoride, 8-hydroxyquinoline and 2,3-dimercaptopropanol (dimercaprol). The generated amount of angiotensin I was measured by the above mentioned radioimmunoassay. A fairish correlation was found between the generated amounts of angiotensin I measured in the Dowex eluate and those found in the incubated plasma. Especially in the lowest range, lower values were obtained by the latter assay. However, the generated amounts of angiotensin I measured in non-incubated plasma samples (3 h at 4 degrees C) was on average 6.4 ng/ml per 3 h and accounted for 748% of the amounts found after incubation at 37 degrees C.


Determination of calcium, copper, magnesium, and zinc content of identical areas in human cerebral hemispheres of normals.

The distribution of calcium, copper, magnesium and zinc in five anatomical regions of both hemispheres of the human brain were investigated. No asymmetry was observed with the exception of the distribution of copper in the white matter. The concentrations of these elements in the substantia nigra from both sides of the midbrain were also measured.


An artifact in the gas chromatographic analysis of urinary organic acids from phenylketonuric children: decarboxylation of the phenylpyruvic acid during extraction.

Phenylpyruvic acid is converted at least partially to phenylacetic acid during the normal extraction procedure used to obtain urinary organic acid profiles of phenylketonuric children by gas chromatography. This decarboxylation reaction can be reduced or completely eliminated by forming oxime derivatives prior to extraction.


Hyperlipidaemia in gout.

Significant elevations of plasma triglyceride and free fatty acids levels were shown in 107 gouty patients, but no significant difference was found in plasma cholesterol and phospholipid levels as compared with control subjects. A positive correlation was found between plasma triglyceride and free fatty acids levels (r = 0.249, P less than 0.05) in gouty patients. The heavy drinkers with gout (15.9% of the patients) had significantly higher plasma triglyceride, free fatty acids and gamma-glutamyltranspeptidase levels than the moderate or non-drinking gouty subjects. These results suggested that excessive intake of alcohol may play an important role in inducing hyperlipidaemia in gout.


The effect of calcium on plasma lipids and bile acid and fecal fat excretion in normolipidemic subjects.

The effect of oral calcium (2 g/day) was studied in four normolipidemic subjects. Calcium caused a significant lowering of plasma cholesterol and a considerable fall in the glycine-/taurine-conjugated bile acid ratio in the intestinal aspirate of one subject, while fecal bile acid excretion rose appreciably in another during treatment. These parameters showed no consistent trend in the other three subjects. None of the subjects showed any significant change in plasma triglycerides and serum calcium and phosphorus during treatment. One subject showed a consistent decrease in every parameter studied throughout the experiment, a trend which was probably due to a concomitant loss in body weight.


Identification of N-acylglycines by gas-liquid chromatography.

Glycine conjugates of aliphatic carboxylic acids of clinical interest, and a series of structurally related compounds, were synthesized. The gas chromatographic elution behavior of trimethylsilyl derivatives of these N-acylglycines was examined on columns of 5% OV-1. A single peak for each compound was observed on the chromatograms after derivatization with a reagent containing N,9-bis-(trimethylsilyl)-acetamide in pyridine (1 : 1, v/v) for 20 min at 60 degrees C. The methylene unit values of the trimethylsilyl derivatives of these N-acylglycines are reported.


An improved method for plasma fibrinogen based on thrombin time measurement.

Methods for plasma fibrinogen based on thrombin time are technically simple, rapid, and sensitive, although "false low" results may occur due to heparin interference. The present modification incorporates Polybrene into buffer to eliminate this heparin interference. The proposed method shown excellent agreement with a reference procedure based on clottable protein, and excellent day-to-day precision (C.V.3.5%). The present method is easily adaptable to semi-automated measurements.


Palmitic acid concentrations and lecithin/sphingomyelin ratios in amniotic fluid.

Palmitic acid concentrations and L/S ratios have been estimated in amniotic fluid specimens with and without centrifugation and cold acetone precipitation. Although the number of cases was small, both of these measurements in uncentrifuged fluid seemed to reflect only indirectly on lung maturation in normal pregnancy while with centrifuged fluid the L/S value predicted RDS in one infant more reliably than palmitic acid concentration.


Studies of blood ascorbic acid levels in acute myocardial infarction.

Fasting serum samples from 53 patients with an acute myocardial infarction were investigated for their vitamin C content during the first week of their illness. The vitamin C levels found were generally within the accepted normal limits. However, there were highly significant lower levels on the second to the fifth post-infarction days, as compared with those found on days six to eight.


A method for the recovery of the constituents of scintillation fluid used in the assay of steroid hormones.

A procedure for the recovery of toluene, and the fluors 2,5-diphenyloxazole, and 1,4-bis-2-(5 phenyloxazolyl)-benzene from used scintillation fluid is described. Toluene is recovered by distillation, and the accumulated residue containing the fluors is dried, and subjected to vacuum distillation and recrystallization. The recovery of the two fluors is 75 and 70%, respectively. The method is relatively simple and could be used in many endocrine laboratories for economy and to reduce volumes of radioactive waste.


The preparation and properties of factor V from bovine plasma.

1. A procedure for the purification of factor V from bovine plasma with a good yield and in a high state of purity is described. The isolation procedure involves BaSO4, adsorption, chromatography of the absorbed plasma on DEAE-Sephadex A-50, activation with thrombin of the A-50 eluate, chromatography on Amberlite CG-50 and precipitation with (NH4)2SO4. Factor V is obtained with a 160% yield and 5000-fold purification. 2. Some of the physico-chemical properties of Ac-globulin have been measured. The molecular weight was determined by electrophoresis is SDS-polyacrylamide gel and found to be 30 000. The studies employing disc electrophoresis and immunoelectrophoresis suggest the existence of several active isoforms of factor V.


[Direct determination of inorganic phosphor in serum and urine utilizing Rhodamin B (author's transl)].

A micromethod is described for the spectrophotometric determination of inorganic phosphate in serum and urine utilizing Rhodamin B as a dye (phosphomolybdat-Rhodamin B complex), Brij 35, and polyvinylpyrrolidon as catalyst. The procedure does not involve deproteinization and yields a stable complex in 20 min. The linearity is constant up to at least 9 mg Pi per 100 ml. It is both accurate (r = 0.972 in serum, r = 0.989 in urine, recovery in urine 98%) and precise (vk = 1.16% in the series). Bilirubin up to 10 mg/100 ml and serum protein do not interfere with the method.


Glycylprolyl beta-naphthylamidase activity in human serum.

Glycylprolyl beta-naphthylamidase activities in sera from 40 normal subjects (18-81 years) were: 22.6 +/- 0.9 (S.E.) (11.8-38.2) I.U./1 serum at 37 degrees C. The enzyme activities did not differ significantly with age between the younger group under 40-years-old and the older group over 40-years-old. Males, especially under 40-years-old, had slight but significantly higher activities than females. The levels were decreased in patients with gastric cancer. The levels were elevated in patients with hepatobiliary diseases, and had significant correlations with the results of the serum tests in hepatic diseases such as glutamic-oxaloacetic transaminase, glutamic-pyruvic transaminase, alkaline phosphatase and total bilirubin, but had no correlation with serum lactate dehydrogenase. In cellulose acetate electrophoresis, normal sera had a single peak at the beta-globulin region, but the sera in hepatitis or liver cirrhosis showed not only an increase in the normal peak at the beta-globulin region but also the appearance of the other one or two new peaks in the alpha1 and alpha2-globulin regions.


Effect of dietary Mo on Cu metabolism. Evidence for the involvement of Mo in abnormal binding of Cu to plasma proteins.

The effects of feeding Mo at concentrations of 17 mug/g to sheep and 100 mug/g to guinea pigs in the presence of adequate dietary Cu, on the distribution of Cu within plasma have been studied. The creation of a fraction of plasma Cu which is insoluble in trichloroacetic acid has been confirmed and it has been shown that this fraction also contains Mo. Complete removal of Cu and Mo from this protein cannot be achieved under acid conditions without at least partial hydrolysis of the protein. The estimated atomic ratio of Cu:Mo in the fraction was 1.7. It is suggested that the formation of such a stable Cu-Mo-protein compound may explain the observed low tissue uptake of Cu in the presence of high plasma total and "direct-reacting" Cu concentrations.


An easy procedure for in vivo estimation of protein binding and correction of elevated serum values induced by venous stasis.

Venous stasis augments the apparent concentrations of serum proteins. A theoretical mathematical model for the correction of serum protein-bound constituents is propounded and an easy procedure for such corrections described. It is suggested that the effect of venous stasis can also be utilized for in vivo estimation of the average protein binding. The hypotheses were tested in 19 epileptic patients. The results obtained by serum determinations of sodium, magnesium, calcium and phenytoin indicate the validity of the theories.


Assay of galactose-1-phosphate uridyl transferase in cultured amniotic cells for prenatal diagnosis of galactosaemia.

We report studies designed to establish optimal conditions for the assay of amniotic cell galactose 1-phosphate uridyl transferase (Gal-PUT) for early prenatal diagnosis of galactosaemia. Methods based on linkage of the reaction to cause of non-specific reactions occurring even in the absence of Gal-1-P. In the final method, sonicates of confluent cultures are incubated with (14-C) Gal-1-P is degraded by treatment with alkaline phosphatase. Gal-PUT specific activities of both control and galactosaemic amniotic cells are higher in non-confluent that confluent cultures.


The origin of the elevated activities of creatine kinase and other enzymes in the sera of patients with myxoedema.

An attempt has been made to establish the origin of the elevated serum creatine kinase which occurs in most patients with myxoedema. Parallel determinations of a number of other serum enzymes were made but the incidence of elevated values was appreciably less than in the case of creatine kinase. Rather surprisingly, the serum amylase activity was found to be increased in more than 50% of the patients studied. Creatine kinase isoenzymes were separated by starch-gel electrophoresis of the sera of 26 patients with myxoedema. In 25 the MM isoenzyme only could be identified while the remaining serum also contained a trace of the MB fraction. Similar isoenzyme studies were made with the sera of normal and thyroidectomized rats, all of which are shown to contain all three isoenzymes. (MM, MB and BB) irrespective of thyroid functional status. No consistent difference was apparent between the patterns exhibited by the thyroidectomized and control groups, and it was concluded that thyroidectomized rats cannot be regarded as a suitable experimental model for the study of this aspect of human hypothyroidism. It is suggested that enzyme release in myxoedema is a non-specific effect, possibly die to diminution in the ATP content of tissues generally. The greater incidence of creatine kinase elevation is probably due to the relatively high concentrations of this enzyme in skeletal muscle, the mass of which is much greater than that of any other tissue.


Glucose and insulin levels on loading with different carbohydrates.

Normal subjects were given, on separate occasions, equivalent amounts of glucose, surcrose (""sugar''), and carbohydrates in the form of bread and starch. Neither the glucose, nor the insulin values showed any significant difference in these persons after they had been loaded with the various carbohydrates. The conclusion that can be drawn from this study is that neither the insulin demand nor the secretion rate of insulin are influenced by the type of carbohydrate given. The rate-limiting step, therefore, is the rate of uptake through the intestinal wall, rather than the hydrolysis of the carbohydrate.


Radioimmunoassay of digoxin in renal failure: a comparison of different commercial kits.

Six commercially available kits for radioimmunoassay of digoxin were compared. When serum from patients with chronic renal failure on maintenance digoxin therapy was analysed, important discrepancies in the results obtained with the 6 kits were found in some of these patients. However, recovery of digoxin added to serum of a healthy volunteer, was within acceptable limits and comparable for the 6 kits. In patients with renal failure not taking digoxin but several other medications, digoxin estimations gave results close to zero. The affinity of the antibodies for some metabolites of digoxin was also assessed: important differences between the kits were found.


An evaluation of the Gilford 3400 automatic enzyme analyser.

An assessment of the Gilford Automatic Enzyme Analyser was conducted over a period of one year. The optics of the instrument were satisfactory with regard to accuracy of wavelength selection and linearity of absorbance response. Excellent precision was obtained for both absorbance readings and operation of the dispenser pump. Carry-over within the microflow-cell was low. The method of operation recommended by the manufacturers for enzyme determinations failed to take account of endogenous blank reactions which could lead to significant error. When revised methods utilising a pre-incubation stage and initiation with a single substrate were employed, the results correlated well with those obtained with standard automatic (LKB 8600) and manual (Pye Unicam SP 800) kinetic systems for aspartate and alanine aminotransferase, creatine phosphokinase and alpha-hydroxybutyrate dehydrogenase, and the precision at all activity levels was satisfactory. Acceptable precision could not be obtained over the clinical range for enzyme assays requiring a blank determination on each sample (5'-nucleotidase and adenosine deaminase) and those with very low normal serum activities (isocitrate dehydrogenase and glutamate dehydrogenase). These limitations appeared to be due to relative insensitivity of the transducer response and liability to optical disturbance. This apart, the instrument has many advantages over alternative equipment.


Photodynamic effects of protoporphyrin on the architecture of erythrocyte membranes in protoporphyria and in normal red blood cells.

Protoporphyrin causes a photodynamic damage of the red blood cell membrane. After illumination of red blood cells in the presence of protoporphyrin three effects can be observed: 1. Red blood cell membranes show particle aggregation on the outer and inner fracture face, as seen in freeze-etch electron microscopy. 2. Electrophorograms of membrane proteins show an increasing protein association, not disrupted by sodium dodecyl sulfate. 3. The immunological response of A+ red cells to anti A serum is progressively retarded. It seems likely that these effects are interrelated consquences of the protoporphyrin-induced photodynamic membrane damage.


Increased pyroglutamic acid levels in patients on artificial diets.

Increased plasma and urine levels of pyroglutamic acid were found in 4 patients being fed the low-lactose food Nutramigen. Pyroglutamic acid was detected and estimated by a variety of methods, and the merits of the techniques used and their application in a screening programme are discussed.


Serum magnesium levles in patients treated with phenytoin.

Phenytoin and magnesium levels were measured in eighty epileptics and seventy-one control subjects in an investigation into possible effects of phenytoin on serum magnesium levels. Phenytoin levels were measured using GLC and magnesium levels by atomic absorption spectrophotometry. The study showed no significant effect of phenytoin on serum mangesium concentration.


Measurement of low molecular weight urinary monoamines by gas chromatography.

A simple gas chromatographic method for the measurement of low molecular weight urinary monoamines has been developed without use of a prior isolation procedure. The primary and secondary monamines in urine were directly converted into their 2,4-dinitrophenyl derivatives with 2,4-dinitrobenzensulfonate in aqueous alkaline solution, which after extraction with benzene and concentration, were submitted to gas chromatography. The application of this method to the determination of methylamine and dimethylamine in urine from normal subjects and hepatic patients is described.


Colorimetric determination of urinary oxalate recovered as calcium oxalate. Application of a simple correction factor for incomplete preciptation.

A method is described for determination of oxalate in urine. Prior to the determination the oxalate is first precipitated from the urine as calcium oxalate. Correction for incomplete precipitation can be made by applying one simple correction formula. The extent of this correction has been established by determination of the recovery of added [14-C] oxalate. The determination of the precipitated oxalate was carried out by an automated version of the colorimetric reaction of oxalate with uranium and 4-(2-pyridylazo)-resorcinol as originally described by Neas, R.E. and Guyon, J.C. in 1972 (Anal. Chem. 44, 799-805).


Factors determining blood phenylalanine in the neonatal period.

The effect of age, sex, birth weight and area of birth on blood phenylalanine has been studied in a group of 41 795 infants. The mean phenylalanine level in low birth weight infants was higher than in those of normal birth weight from six to over 43 days of age. There was a trend of increasing blood phenylalanine with age in both birth weight groups. No  consistent difference was observed between the sexes. In several of the age and birth weight groups, infants living in urban areas had significantly higher blood phenylalanine levels than those in rural areas.


A column radioassay for the quantification of vitamin B-12.

A rapid and convenient column radioassay for the quantification of vitamin B-12 in clinical specimens has been developed. A mixture of the specimen and radiolabeled B-12 was applied to a column containing immobilized intrinsic factor and allowed to incubate for two hours. A buffer wash then separated bound and free B-12. The average intra- and inter-assay coefficients of variation over the range of interest was about 30 pg/ml in the sample and recovery and parallelism studies gave satisfactory results. The values obtained for clinical specimens by the column procedure correlated well with those obtained by reference method.


Polyamine alterations in blood of male homozygotes and heterozygotes for cystic fibrosis.

The polyamines, spermidine and spermine, have been measured in whole blood extracts from control volunteers, patients with cystic fibrosis, and obligate cystic fibrosis heterozygotes. Male homo- and heterozygotes for cystic fibrosis exhibit a consistent and significant decrease in blood spermine resulting in an elevated spermidine/spermine ratio when compared to control males. In contrast, control females exhibited reduced spermidine and spermine levels as compared to control males. Blood from female cystic fibrosis homo- and heterozygotes showed similar results. The sex difference is probably due to fluctiations of blood polyamines during the menstrual cycle. Abnormal polyamine levels are the first observation of an alteration of a low molecular weight metabolite characteristic of both male homo- and heterozygotes for cystic fibrosis.


Concentration of oestrone and oestradiol in follicular fluid and ovarian venous blood of women.

The concentrations of oestrone and oestradiol as measured by a double isotope derivative method in fluid from Graafian follicles at different phases of the menstrual cycle were compared to the corresponding concentrations in ovarian and peripheral venous plasma collected simultaneously. In follicular fluid the concentration of oestradiol was much greater than that of oestrone. The concentrations of oestrogens were similar in fluid collected from small follicles at all phases of the cycle. The concentration of oestradiol in large follicles (greater than 1 cm diameter) was much higher in the mid-late follicular phase of the cycle (mean = 5390 plus or minus 1330 nmol/l) than in large or small follicles at other phases of the cycle. In the mid-late follicular phase of the cycle large follicles were invariably associated with high concentrations of oestradiol in venous plasma draining the corresponding ovary (mean 49 plus or minus 12 nmol/l). The mean ratio of oestradiol/oestrone in fluid from large follicles in which the concentration of oestradiol was greater than 1400 nmol/l (18.0 plus or minus 1.0, n = 10) was significantly higher than the ratio in corresponding samples of ovarian venous plasma (10.7 plus or minus 1.4, n = 11). These findings suggest that when the concentration of oestradiol in a Graafian follicle exceeds 3500 nmol/l it is likely to be functionally active.


The oestrogen provocation test: a method of assessing the hypothalamic-pituitary axis in patients with amenorrhoea.

The oestrogen feedback and gonadotrophin release in ten amenorrhoeic women were investigated, using intramuscular injection of 1 mg oestradiol benzoate. Serial estimations of serum oestradiol and gonadotrophins (LH and FSH) were made over a period of 72 h following the injection. Five patients demonstrated positive feedback release of LH to the oestrogen stimulus with elevated levels of LH significantly above baseline (P less than 0.001), which occurred between 48 and 72 h after the injection. Two of the five patients also demonstrated elevated FSH levels accompanying these LH peaks, The hypothalamic-pituitary axis was postulated to be intact in these five patients, and all ovulated on clomiphene. None of the remaining five subjects showed any increase in serum gonadotrophin levels in response to oestradiol and none ovulated on clomiphene when given a dose of up to 200 mg daily x5 days. This 'oestrogen provocation test" seems to be a useful means of evaluating the functional capacity of the hypothalamic-pituitary axis for gonadotrophin release and has proved useful in predicting responsiveness to clomiphene in amenorrhoeic women.


Comparison of the effect of apomorphine and L-DOPA on serum growth hormone levels in normal men.

Apomorphine hydrochloride (0.75 mg s.c.) has been compared with L-dopa (500 mg p.o.) in their effects on growth hormone secretion in a double blind cross-over study involving nine healthy men. Apomorphine increased serum GH levels above 10 ng/ml in all nine subjects 30-60 min after injection. In contrast, only six of these subjects showed a similar elevation with L-DOPA and in only three had the level increased above 6 ng/ml by 60 min. One subject failed to respond to L-dopa and in two others the peak was less than 6 ng/ml. GH levels were significantly higher at 30, 45 and 60 min following apomorphine than following L-dopa. Apomorphine-induced GH release was not related to changes in serum cortisol or blood sugar. Benztropine mesylate (1 mg i.m.) had no effect on apomorphine-induced GH release. These results suggest: (a) apomorphine may have advantages over L-dopa as a provocative agent to assess GH secretory capacity; (b) a dopaminergic mechanism subserves GH secretion; (c) cholinergic mechanisms do not antagonize dopaminergic-related GH release.


Serum triiodothyronine in solitary autonomous nodules of the thyroid.

Seventeen patients with solitary autonomous nodules of the thyroid were studied. Eight had clinical features of hyperthyroidism though in some the clinical manifestations were mild. The serum T3 concentration was elevated in all patients with hyperthyroidism but the serum T4 and free thyroxine index were within the normal range in five. All patients with hyperthyroidism subsequently responded to treatment. These findings suggest a high incidence of preferential T3 hypersecretion in hyperthyoidism associated with solitary autonomous thyroid nodule. A further nine patients with single autonomous nodules were clinically euthyroid with normal serum T3 and T4 concentrations and remained euthyroid from 6 to 24 months on serial review.


Hypoglycaemia associated with an intrathoracic fibrosarcoma.

A patient with an intrathoracic fibrosarcoma in whom disabling hypoglycaemic episodes occurred is reported. No further hypoglycaemic episodes occurred following removal of the tumour. The mechanism of the hypoglycaemia associated with non-pancreatic tumours is discussed. It seems that inadequate hepatic glucose output was an important factor in contributing to the hypoglycaemia in this patient.


Serum gonadotrophins in young children.

LH and FSH were assayed in serum samples from children ranging from newborn to 13 years. In boys, LH was found in most samples up to 4 months of age, in many up to 10 months, but in only 38 percent between 1 and 8 years. In girls, it was found in only 29 percent of the samples under 1 year and the frequency and concentration changed little thereafter until 8-10 years. FSH was detected in all samples from boys up to 4 months and in most of those from girls up to 2 years. After these ages the frequency declined in each sex and there was little further change until 8-10 years. Between 1 and 8 years the proportion of samples containing either FSH or LH was similar for the two sexes, but whereas in boys high LH tended to be associated with high FSH, and vice versa, there was no such correlation in girls. The results are discussed in relation to gonadal development and steroid synthesis.


The pathological anatomy of the Smith-Lemli-Opitz syndrome.

Two cases of the Smith-Lemli-Opitz syndrome are described, together with the autopsy findings. In both cases, the typical appearance and visceral malformations were present. Hypoplasia of the frontal lobes and corpus callosum, and aplasia of the splenium constitute abnormalities of the brain which may be useful in the diagnosis of this disorder at autopsy. The autosomal recessive mode of inheritance of this syndrome was confirmed.


Chromosomal mosaicism in amniotic fluid cell cultures.

Six cases of chromosomal mosaicism detected in amniotic fluid cultures are described. In five of these there was no evidence of fetal mosaicism. In one case fetal mosaicism was demonstrated but only by the study of fibroblasts since blood cultures showed only normal cells. The implications of amniotic fluid mosaicism are discussed and it is concluded that this usually does not indicate fetal mosaicism. The value of repeated amniocentesis in the diagnosis of fetal mosaicism was demonstrated by findings in three of the cases. It is recommended that amniotic fluid cultures be harvested in situ for chromosome studies and that cytogenetic results be expressed as number of colonies karyotyped rather than as number of cells analyzed.


XX males: two new cases.

Two new cases of phenotypic males with 46,XX karyotype are presented. Fluorescence, autoradiographic and centromeric heterochromatin studies in several lines, including testicular cells, failed to demonstrate the existence of the Y chromosome or the existence of distal Yq material translocated to another chromosome in the two patients. The Xg study in one of the patients and his family provided direct evidence of transmission of an X chromosome from father to son. We present indirect evidence favoring the mutation theory to explain the XX male phenotype.


Dicentric X-isochromosome (Xqi dic) and pericentric inversion of No. 2 [inv(2) (p15 q21)] in a patient with gonadal dysgenesis.

A patient with the clinical stigmata of gonadal dysgenesis is presented. Cytogenetic investigations revealed two distinct structural chromosome rearrangements. One of these, an isochromosome for the long arm of the X, proved to be a dicentric element following C-banding. The second abnormality, an inherited familial marker, was a pericentric inversion of No. 2 [(inv 2) (p15q21)].


Serum esterases of Icelanders. I. A "silent" pseudocholinesterase gene in an Icelandic family.

During an investigation of cousin marriages in Iceland, five brothers and sisters were found to be homozygous for the "silent" allele of plasma cholinesterase. Clinical information on two family members is presented and discussed, and the possibility of the presence of a "nearly silent" plasma esterase allele, in one of the family units investigated, is suggested.


A rapid micro culture method of chromosome preparations from fibroblasts and amniotic cells.

A micromethod enabling the making of chromosome preparations from fibroblasts and amniotic cells cultured on surface-treated Microtest II plates is presented. Preparations from each well contain sufficient metaphases to perform a reliable diagnosis. The potential for the use of this method in early prenatal diagnosis is discussed.


Evidence for an autosomal recessive form of cleidocranial dysostosis.

Three cases of cleidocranial dysostosis from two unrelated consanguineous families are reported. The family setting, the distribution of the affected members, plus the severity of involvement suggest that there is also an autosomal recessive form of this disorder.


Segregation of a t(14q22q) chromosome in a large kindred.

A large kindred is reported in which 21 members are balanced t(14q22q) carriers. The components of the translocation were identified by autoradiography and G-banding. With the exception of the index case, who was retarded, all of the carriers were phenotypically normal. The segregation pattern of the translocation chromosome was determined in two complete generations. All eight of the progeny in one generation were balanced carriers, and the carrier father of this generation may have been homozygous for the t(14q22q) chromosome. Segregation in the next generation was closer to the expected 1:1 ratio of carrier to non-carrier, the ratio being 11:13.


Thin ribs in neonatal myotonic dystrophy.

The recently described thin ribs seen in a neonate suffering from myotonic dystrophy represents a valuable sign for early detection of this condition. Thin ribs were found on chest radiographs of two siblings a short time after birth. This led in retrospect to the diagnosis of neonatal myotonic dystrophy. The diagnosis was confirmed by clinical and electromyographic data of myotonic dystrophy in the mother who was not previously known to have the disease. Both children died at the age of 2 days from respiratory distress. All children of affected mothers should have a chest radiograph soon after birth in order to help in diagnosis and to establish the frequency of this sign.


Congenital urinary tract malformations: epidemiologic and genetic aspects.

436 index patients with major congenital urinary tract malformations, 385 with upper and 51 with lower urinary tract anomalies, were studied. A significant male sex predominance was noted in each group. No apparent correlation was found between parental age, birth order, birth weight and incidence of these malformations. The association with abnormalities outside the urinary tract was more frequent in the upper urinary tract group. In this group, the mean consanguinity index was 283-10(-5) and, among those patients where a family study was made, 16.6% had positive family histories. The incidence of urinary tract malformations was 4.0% for the first degree relatives, and 1.1% for second degree relatives (grandparents only). In this group, the concordance rate was 50% in four monozygotic, and 0% (nil) in three dizygotic, twin pairs. The findings, in agreement with studies of other congenital malformations, suggest at least in part, a multifactorial etiology, particularly in the case of upper urinary tract malformations, depending upon genetic predisposition and environmental factors.


Autosomal recessive syndrome of cerebellar ataxia and hypogonadotropic hypogonadism.

An ataxia-hypogonadism syndrome is reported in at least four of 15 family members (two brothers and two sisters). Consanguinity could be proven by genealogical studies; parents were second cousins. The onset of cerebellar ataxia in three sibs was at about 12-20 years, in the proposita at 33-38 years; progression was very slow. Hypogonadotropic hypogonadism was reflected in failure of maturation of secondary sexual characteristics, eunuchoidism, absence of libido and infertility. The concurrence of hereditary ataxia and hypogonadotropic hypogonadism is discussed and explained as pleiotropic effects caused by the homozygous state of a rare autosomal recessive gene. A review of the literature suggests that this is a previously undescribed disorder.


Bone mass in men with Klinefelter's syndrome and in normal subjects, estimated by the cortical thickness of bone.

Metacarpal cortical thickness has been measured in a sample of 47,XXY men and two control samples of 46,XY men and 46,XX women in the age range 20-70. The results suggest that in this age range cortical thickness in 47,XXY men is more similar to that of normal women than normal men.


The evaluation of infants with the Zellweger (cerebro-hepato-renal) syndrome.

A brief overview of the clinicopathologic findings in the cerebro-hepato-renal syndrome of Zellweger (ZS) is presented. In order to understand more clearly the many diverse features of the ZS condition, a guideline is suggested for evaluation of a ZS infant in terms of physical features, family history, clinical pathophysiologic parameters, biopsy specimens, and postmortem procedures. The references provide rationale pertinent to the subject of discussion and/or furnish comments upon technical aspects for performance of analytical procedures.


Bilateral teratoma of testis in two brothers with 47,XXY Klinefelter's syndrome.

Two brothers, the only children of healthy, unrelated parents with normal karyotypes, had 47,XXY-Klinefelter's syndrome and bilateral testicular teratomas. The oldest XXY-boy had, in addition, congenital hydrocephalus caused by congenital stenosis of the aqueduct of Sylvius.


Congenital ichthyosis, mental retardation, dwarfism and renal impairment: a new syndrome.

A new congenital ichthyotic syndrome inherited as an autosomal recessive is described in three propositi of an Iranian family. The main clinical features are non-bullous congenital ichthyosis, mental retardation, dwarfism, and renal impairment. The nephropathy which previously has not been associated with congenital ichthyosis was manifested by raised blood urea nitrogen and creatinine levels, and a reduced creatinine clearance. The clinical and genetic features of this syndrome are discussed in relationship to the other congenital ichthyotic syndromes.


Diabetes mellitus: discrimination between single locus and multifactorial models of inheritance.

Family data from 6,559 diabetic propositi were analyzed using the method of complex segregation analysis in an attempt to discriminate the two models of two-allele single-locus inheritance and multifactorial inheritance for early, middle, and late onset diabetes. The three parameters in the single locus model were: degree of dominance, penetrance, and proportion of phenocopies. In early onset diabetes, the heritability estimated from the multifactorial model was so high as to inidcate major gene action. In middle and late onset diabetes, best fitting single-locus models were found to explain the data as well as the multifactorial model.


Free amino acids in extracts of cultured skin fibroblasts from patients with various amino acid metabolic disorders.

In the search for a simple screening test for prenatal diagnosis of amino acid metabolic disorders, we compared the free amino acid contents in the extract of cultured skin fibroblasts from normal individuals with that from patients with 10 metabolic disorders: maple-syrup urine disease; homocystinuria due to cystathionine synthase deficiency; homocystinuria due to N5, 10-methylene-tetrahydrofolate reductase deficiency; citrullinemia; argininosuccinic acidemia: propionic acidemia; hyperprolinemia Type II; non-ketotic hyperglycinemia; hydroxyprolinemia; and hyperonithinemia. An accumulation of abnormal metabolites was not found in any of the disorders except argininosuccinic aciduria. Argininosuccinic acid anhydrides were detected in cell extracts from all four patients only after the extract was boiled at acid pH for 2 1/2 h. Thus, it is concluded that the measurement of free amino acids in extracts from cultured fibroblasts is not a useful screening technique in the diagnosis of inborn errors of amino acid metabolism.


Cystic fibrosis heterozygote detection: a family study.

Family studies have been done to determine if the phenotypes described for the cystic fibrosis (CF) cultured cell reliably detected the CF gene. Two culture phenotypes were studied in culture derived from consecutive generations in four CF families: (1) cystic fibrosis factor (CFF) in the medium of short-term white blood cell cultures assayed by a modified oyster ciliary test and (2) the three characteristics of cultured skin fibroblasts (metachromasia without alcianophilia at 0.3 M MgCl2, CFF in the culture medium and metabolic cooperation with normal fibroblasts). As CF is an autosomal recessive disorder, the family offered a test unit for determining the specificity of these cell phenotypes for the CF gene. On the basis of detecting the CF culture phenotypes in the homozygote and obligatory heterozygotes, the parents, and their segregation in consecutive generations, detection of the CF gene was not possible in the white blood cell cultures, but was possible in the skin fibroblast cultures.


The relationship of plasma levels of pindolol in hypertensive patients to effects on blood pressure, plasma renin and plasma noradrenaline levels.

1. Fifteen, previously untreated, hypertensive patients were given 20 mg of pindolol, orally. The systolic and diastolic blood pressures fell significantly in 1 h; the effect was maximal 4 h after pindolol, and persisted for at least 8 h. 2. After oral administration of 20 mg of pindolol, its concentration in the plasma reached a peak in 2-3 h. At the end of 8 h, pindolol was not detectable in the plasma. 3. There was a significant relationship between the peak concentration of pindolol in plasma and the maximal change in blood pressure in fifteen previously untreated hypertensive patients. In a separate study of nine-nine hypertensive outpatients taking 15-80 mg of pindolol daily, the blood pressure responses corresponded generally to the concentration of pindolol in plasma 2-3 h after the morning dose. 4. There were no significant changes in plasma renin activity, plasma renin concentration or plasma noradrenaline concentration in the previously untreated patients taking 20 mg of pindolol. There was no relationship between initial plasma renin or noradrenaline levels and blood pressure responses to pindolol. Nor was there any significant relationship between the changes in plasma renin or noradrenaline levels and the changes in blood pressure.


Human cardiorespiratory responses to acute cold exposure.

1. Respiratory and circulatory functions of minimally clad human subjects were studied before and during acute exposure to ambient temperatures of 4.5-6.5 degrees C. 2. After 1 h of cold exposure, subjects showed increases of ventilation, O2 UPTAKE AND CARDIAC OUTPUT. Rectal temperatures fell. 3. During exercise in the cold conditions, oxygen uptake and cardiac output were greater than during the same exercise at normal temperature. 4. The increased cardiac output during cold exposure was achieved by an increase of stroke volume rather than heart rate; this finding is in contrast to changes during bicycle exercise and isometric exercise at normal ambient temperatures. 5. We conclude that the cardiorespiratory effects of cold exposure are not superseded by the response to moderate exercise. The difference between heart rate and stroke volume at increased levels of cardiac output during exercise at normal temperatures and during rest and exercise in cold conditions may be explained by changes of arterial baroreceptor input and of blood catecholamine levels.


Measurement of glomerular filtration rate by fluorescent excitation of non-radioactive meglumine iothalamate.

The clearance of non-radioactive meglumine Iothalamate (Conray 60), assayed by fluorescent excitation analysis, has been shown to be a good indicator of the glomerular filtration rate (GFR). Investigations in rats by the constant infusion technique showed a good correlation with insulin clearance. In a group of ten children and one adult, we obtained excellent agreement between GFR determinations by clearance of Conray 60 and I-125 sodium Iothalamate, using the single injection technique, and taking samples from 10 min to 4 hr after injection. The decay curve was resolved into two exponential components. We have also shown that the 3 and 4 hr samples, fitted to a single exponential function, yield good agreement with GFR determinations using a double exponential model. The GFR determination method presented here is accurate, simple, cost effective, and involves no radiation exposure to the patient.


Effects of blockade of extraneuronal uptake on responses to isoprenaline in perfused rat heart.

1. Isolated rat hearts accumulated 102 pmol/g wet wt/min of isoprenaline when perfused for 5 min with 0-6 muM (+/-)-3H-isoprenaline. 2. The 3-methoxy derivative of isoprenaline ('methoxy isoprenaline') (10 muM) significantly inhibited this uptake by 57%, metanephrine (10 muM) by 29% and normetanephrine (10 muM) by 21%. 3. (+/-)-Isoprenaline (0-6 muM) infused into isolated perfused rat hearts for 5 min activated glycogen phosphorylase 2-4-fold. Normetanephrine (10 muM) or metanephrine (10 muM included in the perfusate significantly potentiated this activation, but 3-0-methyl isoprenaline (10 muM significantly reduced it. However, 3-0-methyl isoprenaline potentiated the ability of 4-8 muM isoprenaline to stimulate phosphorylase. 4. Neither metanephrine (10 muM) nor normetanephrine (10 muM) altered peak inotropic responses to injections of (+/-)-isoprenaline into the solution perfusing isolated rat hearts. 3-0-methyl isoprenaline (10 muM) shifted the isoprenaline dose-response curve to the right, but did not affect the inotropic responses to CaCl2, confirming that 3-0-methyl isoprenaline possess beta-adrenoceptor antagonist activity. 5. Inotropic responses to isoprenaline were significantly prolonged by both 3-0-methyl isoprenaline and normetanephrine (10 muM). 6. These results indicate that blockade of extraneuronal accumulation of catecholamines causes potentiation of both metabolic and mechanical beta-adrenoceptor-mediated responses of the heart to isoprenaline. It is suggested that Uptake2 and the cardiac beta-adrenoceptor are separate entities, and that the beta-adrenoceptor is localized in the sarcolemma. The physiological function of Uptake2 may be to help clear the sympathetic synaptic gap of liberated neurotransmitter.


Effects of brain lesions on the antinociceptive properties of morphine in rats.

1. Electrolytic lesions were made in various brain regions of the rat, and the effects of these lesions on nociceptive threshold and the antinociceptive actions of morphine were tested using a shock titration technique. 2. Lesions in the medial thalamus, the periaqueductal grey area, or the caudate nucleus, had no effect on the nociceptive threshold; whereas, lesions in the posterior hypothalamus resulted in a small but statistically significant increase in this threshold. 3. Morphine administered intraperitoneally to rats having histologically verified lesions in the posterior hypothalamus, the caudate nucleus or the periaqueductal grey area resulted in a 15-30% increase in the nociceptive threshold. This increase was similar to that observed in unoperated control rats. On the other hand, injections of morphine into animals having greater than 50% of the medial thalamus destroyed produced a highly significant increase of 95% in the threshold. This potentiation of the antinociceptive action of morphine was not observed in rats having less than 50% destruction of the medial thalamus.


Clearances of complement components, C3 proactivator and other serum proteins in chronic membranoproliferative glomerulonephritis (CMPGN).

In chronic membranoproliferative glomerulonephritis (CMPGN) the activation of the complement system through the properdin pathway plays an important role. The clearance of complement components and of the C3-proactivator (C3-PA) have been determined in 18 patients. Hemolytically active C5, C6, C7 and C3-PA were detected in the urine for the first time. The clearances of the complement components  did not correlate with the clearances of other serum proteins with similar molecular weights. The specificities of the single complement components in the urine were tested by specific complement inhibitors such as hydrazine, KSCN, and the C4-inactivating factor.


Plasma renin concentration in hypertension produced by unilateral renal artery constriction in the rat.

1. Plasma renin concentration (PRC) and blood pressure were studied sequentially, 24 h to 42 days post-operatively, in rats subjected to unilateral renal artery constriction without contralateral nephrectomy. 2. The PRC of rats failing to develop hypertension remained normal, whereas the mean PRC of twenty-two rats that became hypertensive was five times normal on day 14 of the study when the hypertension was becoming established. 3. In eleven of the twenty-two rats that became hypertensive, PRC did not exceed the upper limit of normal. In the remaining hypertensive rats, the increase in PRC was not always temporally related to the increase in blood pressure. A significant correlation between PRC and blood pressure did not emerge until day 35 of the study. 4. Despite these anomalies, linear regression analysis of 169 pairs of PRC and blood pressure measurements during the 42 day period of development of hypertension in twenty-two rats revealed a highly significant correlation between log PRC and blood pressure (P smaller than 0.001). 5. It is concluded that factors other than the plasma concentration of renin are involved in the early stages of development of hypertension induced by renal artery constriction. Nevertheless, PRC and blood pressure are intricately related.