Comparison of developmentally regulated lectins from three species of cellular slime mold. Extracts of the cohesive forms of the cellular slime molds Dictyosteliym discoideum, Dictyostelium mucoroides and Dictyostelium purpureum contain lectin activity, assayed as hemagglutination activity. The lectin activity from each species binds quantitatively to Sepharose 4B and can be eluted with D-galactose. The resultant purified lectins are abundant proteins representing, in the case of D. purpureum, up to 5% of the total soluble protein of cohesive cells. The preparations from each species are similar but distinct in amino acid composition and other properties. Each purified preparation gives rise to two protein bands on sodium dodecyl sulfate-polyacrylamide gel electrophoresis with the major band representing as little at 77% (D. purpureum) and as much as 96% (D. mucoroides) of the total protein in the two bands. The molecular weights of the pair of bands were different for each species, ranging between about 23 000 and 26 000. The two bands are believed to represent subunits of lectins made up of either one or a combination of these two proteins. The apparent molecular weights of the purified lectin activities determined by sucrose density gradient centrifugation were all in the range of 100 000. N-Acetyl-D-galactosamine was a potent inhibitor of the hemagglutination activity of each perparation; but there were some differences in the relative inhibitory potency of a number of other saccharides. Antiserum raised against each preparation, as well as univalent antibody fragments derived from these antisera, reacted best with the antigens to which they were raised; but showed some cross reaction measured both by precipitin reactions and by inhibition of hemagglutination activity of the purified lectins. The differences between the lectins from the different species could be trivial; but they also could be important for defining specific properties of these three species which reliably segregate into colonies of a single species when grown in mixed culture.


Inhibition of the binding of cytochrome b5 to phosphatidylcholine vesicles by cholesterol. The binding of cytochrome b5 to single-walled liposomes of egg phosphatidylcholine was inhibited by the presence of cholesterol in the lipid bilayer under conditions where a limited amount of liposomes was incubated with the cytochrome. Since similar conditions seem to apply for the binding of cytochrome b5 to erythrocyte ghosts, this observation supports the conclusion of Enomoto and Sato (Enomoto, K. and Sato, R. (1977) Biochim. Biophys. Acta 466, 136--147) that the localization of cholesterol on the outer surface of the ghost membrane prevents the binding of cytochrome b5 to this surface. The finding reported by Roseman et al. (Roseann, M.A., Holloway, P.W. and Calabro, M.A. (1978) Biochmi. Biophys. Acta 507, 552--556) that cholesterol did not prevent the cytochrome binding to phosphatidylcholine liposomes in the presence of a large excess of liposomes could be confirmed in the present study, but this does not contradict the abovementioned conclusion.


Bilayer rigidity of the erythrocyte membrane2H-NMR of a perdeuterated palmitic acid probe. Perdeuterated palmitic acid was intercalated into the human erythrocyte membrane and its motion studied by dueterium nuclear magnetic resonance (2H-NMR). From analysis of temperature dependent changes in the 2H-NMR spectra and from an analysis of derived moments we conclude that the acyl chains of the erythrocyte lipids do not exhibit a detectable phase transition.


Starch metabolism in Pseudomonas stutzeri. II. Purification and properties of a dextrin glycosyl-transferase (D-enzyme) and amylomaltase. Amylomaltase and disproportionating enzyme (D-enzyme) were purified to homogeneity from cell-free extracts of Pseudomonas stutzeri using a six-step procedure. The presence of both glycosyltransferases in the same organism has not been reported before. Molecular weight determination by gel chromatography gave a value of 74,000 for the amylomaltase and 115 000 for the D-enzyme. Two subunits of different molecular weight were found in each enzyme as proved by sodium dodecyl sulfate-gel electrophoresis. The optimum pH of amylomaltase and D-enzyme activity is 7.6--7.7. Action of both glycosyltransferases on different maltodextrins showed that amylomaltase is most active with maltotetraose, and the Km value for this substrate is 7.1 mM. D-Enzyme catalyzed glucose release from maltose (Km = 8.3 mM) at a higher rate than from maltotriose and maltotetraose. With maltotriose as initial substrate, D-enzyme forms glucose, maltopentaose, maltoheptaose, maltononaose, maltoundecaose as major products. Amylomaltase acts on maltotriose, maltotetraose, and maltopentaose to form a series of homologous 1,4-alpha-glucans. No essential chain-lengthening reaction occurred with maltohexaose.


Activation of glutaminase by phosphoribosyl-pyrophosphate and its interference with the assay of phosphoribosylpyrophosphate amidotransferase. Phosphate-dependent glutaminase (L-glutamine amidohydrolase, EC 3.5.1.2) from rat liver was found to be strongly activated by phosphoribosylpyrophosphate (P-rib-PP), the substrate of amidophosphoribosyltransferase (EC 2.4.2.14). Since the assay of the latter is based on the P-rib-PP-dependent conversion of glutamine to glutamate, the amidotransferase activities determined in crude tissue preparations were found to be too high. The interference of glutaminase, however, could be completely eliminated by its inactivation at 50 degrees C. Amidotransferase was not affected by the heat treatment. Because of the increased rate of the glutamate formation at this temperature, the incubation time of the assay could be significantly reduced.


A microsomal exoribonuclease from rat liver. A exoribonuclease has been purified from the microsomes of rat liver. The enzyme had an apparent molecular weight of 80 000-83 000 and produced, via a processive mechanism, 5'-AMP as the only product from poly(A). The degradation was found to proceed in the 3' to 5' direction. The relative rates of breakdown of synthetic polynucleotides by the enzyme under standard conditions were in the order poly(A) equal to poly(U) greater than poly(C). In addition to Mg2+, K+ was required for maximum activity. The enzymic activity was inhibited by p-chloromercuribenzoate and poly(G), but not by a rate liver RNAase inhibitor. The effect of spermine on the breakdown of synthetic polynucleotides by the enzyme has been studied. In the absence of K+, the breakdown of poly(C) was stimulated and that of poly(A) was stimulated slightly. However, the breakdown of poly(U) was inhibited slightly by spermine.


Evaluation of negative staining technique for determination of CN--insensitive superoxide dismutase activity. The different forms of superoxide dismutase (superoxide-superoxide oxidoreductase, EC 1.15.11) have been studied, in tissues of rat, mouse and chicken, by the ectrophoresis-nitro blue tetrazolium technique proposed by Beauchamp. Similar enzyme patterns were evident in every tissue. A fast migrating CN--sensitive form of dismutase activity was present in isolated liver mitochondria of each species. Chicken and mouse liver mitochondria, as well as whole homogenate of every tissue of these two species, showed two additional slow-migrating bands of CN--insensitive activity. In contrast, such bands were not detectable in mitochondria isolated from rat liver or in any of the rat tissues analyzed by this technique. Prior to their electrophoretic separation, the samples were analyzed for CN--insensitive superoxide dismutase activity by a spectrophotometric assay; by this assay it was possible to demonstrate and quantitate a CN--insensitive superoxide dismutase activity in every preparation. Two units of CN--insensitive activity were applied to the gels for each sample. These results indicate that the electrophoresis-nitro blue tetrazolium technique is unsuitable for the detection of the rat CN--insensitive form of superoxide dismutase in crude preparations such as whole tissue homogenates or isolated mitochondria.


The purification and characterization of ADP-glucose pyrophosphorylase A from developing maize seeds. ADPglucose pyrophosphorylase A (ATP:alpha-D-glucose-1-phosphate adenylyltransferase, EC 2.7.7.27) from developing maize (Zea mays) endosperm was purified 129 fold to apparent homogeneity. The molecular weight estimated by gel filtration and by polyacrylamide gel electrophoresis was 375 000 and 400 000, respectively. The preparation gave a single protein band after SDS-polyacrylamide gel electrophoresis suggesting a monomer mol. wt. of 96 000. It was concluded that ADPglucose pyrophosphorylase A in maize endosperm is a tetramer of four similar molecular weight subunits. Values for the Km for glucose 1-phosphate and ATP were 3.8 . 10(-5) and 1.8 . 10(-4) M, respectively (using the homogeneous preparation).


Purification and some properties of liver and brain beta-N-acetyl-hexosaminidase S. beta-N-Acetyl-hexosaminidase S (2-acetamido-2-deoxy-beta-hexoside acetamido-deoxyhexohydrolase, EC 3.2.1.52) was purified from liver and brain of a patient deceased of type O GM2 gangliosidosis (Sandhoff's disease). Brain beta-N-acetyl-hexosaminidase S was further purified by preparative polyacrylamide gel electrophoresis. The pH optimum of the purified liver and brain enzyme was 5.0 and Km values were 0.8--0.9 mM and 0.3--0.4 mM with 4-methylumbelliferyl-beta-D-N-acetylglucosamine and beta-D-N-acetylgalactosaminide derivatives, respectively. beta-N-Acetyl-hexosaminidase S was thermolabile losing most of its activity after 50 min at 50 degrees C. The apparent molecular weights of the purified liver and brain enzymes were 154 000 and 152 000, respectively. Hexosamines activated beta-N-acetyl-hexosaminidase S whereas the isoenzyme A and B were inhibited. The glycoprotein nature of beta-N-acetyl-hexosaminidase S was suggested by its affinity towards Concanavalin A-Sepharose.


Aggregation of activated platelets with Walker 256 carcinoma cells. Walker 256 carcinoma cells form irreversible aggregates with rat platelets activated by ADP or serotonin. Since serotonin induces platelet shape change but not platelet aggregation the degree of activation indicated by the disc-sphere transformation is sufficient for platelets to interact with these tumor cells. This is confirmed by experiments with spheroid washed platelets which form irreversible mixed aggregates with Walker 256 carcinoma cells without a stimulus being required. This type of tumor cells could react with platelets in vivo, provided the platelets are activated by disturbed blood flow or contact with subendothelium. Our observations can explain why other authors found no interaction between Walker 256 carcinoma cells and non-activated platelets in vitro even though platelets contributed to the formation of bloodborne metastases of this tumor.


Classical haemophilia in a girl.

Classical haemophilia in a girl. A three-year-old white girl from a haemophiliac A family was a symptomatic carrier. The clinical and laboratory data concur with the form of a heterozygous symptomatic carrier state.


Reaction of human granulopoiesis to high-dose cyclophosphamide therapy. The reaction pattern of an unperturbed human granulopoiesis to pulses of high-dose chemotherapy (cyclophosphamide 2000 mg/m2 plus vincristine 1.4 mg/m2 or adriamycin 20 mg/m2) was serially studied in 6 patients. The stem cells committed to granulopoiesis (CFU-C) of the bone marrow and the cells of the proliferative granulocytic marrow pool were considerably reduced during the first 8 days. Granulopoietic regeneration was first recognizable by increased proliferative activity of bone marrow CFU-C (3H-thymidine technique). The cytotoxic drug-induced injury to the early compartments of granulopoiesis, and granulocytic regeneration proceed sequentially through the ensuing, increasingly differentiated granulocytic compartments. In the peripheral blood, depletion and repletion of the CFU-C pool precede the corresponding changes of segmented neutrophils by 7 to 9 days; during granulocytic regeneration, peripheral blood CFU-C show a transient greatly overshooting decrease.


Appearance of new alpha-bungarotoxin-acetylcholine receptors in cultured sympathetic ganglia of chick embryos. alpha-Bungarotoxin (alpha-BuTX) has been used as a marker for studying the production of alpha-bungarotoxin-acetylcholine receptors (alpha-BuTX-AChRs) in explants of chick embryo sympathetic ganglia cultured in vitro. New alpha-BuTX-AChRs appear rapidly in the explants after blocking of the pre-existent ones with the toxin (40% of the total receptors at 3 h). There is a portion of alpha-BuTX-AChRs in the explants which for a short time is not accessible to the toxin. This portion constitutes the precursor pool of receptors and represents 18% of the total. The precursor pool of receptors supplies the neurons with new receptors for 1-2 h in the absence of protein synthesis. The appearance of new receptors from the precursor pool is an energy-dependent process.


Explant culture of adult goldfish retina: a model for the study of CNS regeneration. Conditions are described for culture of retinal explants of adult goldfish which favour outgrowth of neuritic processes onto a substratum. A growth index to quantitate the outgrowth was developed. If the optic nerve is crushed several days prior to explantation, a marked enhancement of neuritic outgrowth is seen relative to control retinas. Histological examination of the explants revealed that retinal ganglion cells in explants from unoperated eyes became hypertrophied in vitro with a time course similar to that observed in vivo following optic nerve crush. Experiments with hemiaxotomized retinas indicate that the perikaryal regenerative response is mediated intracellularly.


Visual stimulation increases regional cerebral blood flow and metabolism in the goldfish. Studies with radioactive antipyrene and deoxyglucose indicated that both blood flow and metabolism are enhanced in the goldfish optic tectum following a brief visual stimulation. It is concluded that the brain of cold-blooded animals demonstrates regionally regulated physiological alterations, previously reported only in warm-blooded species.


Anatomical correlates of rhythmical slow wave activity (theta) in the hippocampal formation of the cat. The topography of spontaneous and hypothalamically induced hippocampal rhythmical slow wave activity (theta) was studied acutely in cats anesthetized with urethane. Tracking and depth profile analysis using microelectrodes showed two amplitude maxima of theta activity approximately 180 degrees out of phase separated by a null zone. One amplitude peak was located in stratum oriens of CA1 (maximum amplitude 1.2 mV) and the other peak in stratum moleculare of the fascia dentata (maximum amplitude 1.9 mV). The null zone was localized to stratum radiatum, just ventral to the CA1 pyramidal cells. The two 'generator' hypothesis of theta activity was discussed in relation to similar findings for other species. Pharmacological results were interpreted as supporting the view that there is an ascending cholinergic input mediating theta in the urethanized cat.


Synaptically identified hippocampal slow potentials during behavior. Averaged evoked slow-wave potentials (AEPs) were recorded from various locations within the dentate gyrus and CA1 field of the hippocampus of 16 rats during the performance of an operant tone discrimination task. Consistent time-locked tone averaged evoked potentials (AEPs) were recorded from the perforant path zone in the outer molecular layer of the dentate gyrus. Tone AEPs were never present in this region (1) prior to development of the discrimination, (2) during behavioral extinction, or (3) during the performance of other operant behaviors. Results are discussed in terms of the functions of the perforant path in neural and behavioral plasticity.


Toxic effects of kainic acid on mouse cerebellum in tissue culture. Cultures of mouse cerebellum were exposed for various intervals after explantation to kainic acid, a glutamic acid analog. Purkinje cells and intracerebellar nucleus neurons were destroyed and cortical laminar formation was inhibited by exposure to kainic acid, while granule cells were relatively spared. Prolonged kainate treatment also reduced the granule cell population. The destructive effects of kainic acid were evident upon exposure of Purkinje cells prior to the development of parallel fiber-Purkinje cell synapses, the neurotransmitter for which is believed to be glutamic acid. Glutamate application to intracerebellar nucleus neurons in vitro did not evoke extracellularly recorded excitatory effects, suggesting that these kainate-sensitive neurons do not have significant numbers of glutamate receptors. The combination of these observations suggests that neuronal toxic effects of kainic acid are not exclusively mediated by action on glutamate receptors, but involve other, less specific mechanisms as well.


Androgen receptor in the rat brain--assays and properties. The existence and relevance of an androgen receptor in the developing brain has been a matter of controversy. We here describe both sucrose density gradient and hydroxylapatite assays which clearly define a distinct androgen receptor in the 24-day-old rat hypothalamus, amygdala and preoptic region, but not in the cortex. This receptor has considerable affinity for estradiol-17beta, thus perhaps accounting for some uncertainty about its nature, but none for diethylstilbestrol or other estrogens, antiestrogens or glucocorticoids. Its Kd for both dihydrotestosterone and testosterone is about 1 X 10(-9) M and for estradiol about 2 X 10(-8) M. Its properties are generally consistent with those of androgen receptor reported for other tissues.


Cell suspensions from rat olfactory neuroepithelium: biochemical and histochemical characterization. Cell suspensions were generated from rat olfactory epithelium by digestion with collagenase and hyaluronidase followed by gentle mechanical disruption. These cell suspensions excluded nigrosin dye and synthesized RNA, protein and carnosine from radiolabeled precursors. Sustentacular cells, repiratory epithelial cells and olfactory neurons but not basal cells could be identified by phase-contrast microscopy. Sedimentation of these cell suspensions at unit gravity in discontinuous gradients of buffered bovine serum albumin resulted in partial separation of the various cell types as indicated by the distribution of several biochemical markers. Olfactory marker protein and carnosine synthetase activity were found in the upper gradient fractions, while carnosinase activity was present predominantly in the lower gradient fractions. Cellular localization of olfactory neuron marker protein and non-neuronal S-100 protein by immunoperoxidase staining of gradient-fractionated cells indicated that neuronal cells were only partially separated from non-neuronal cells by our fractionation techniques. Evaluation of gradient fractionated cells by histochemical staining for carbohydrates demonstrated that secretory Bowman's gland cells were quite efficiently separated from neurons. This study demonstrates the ease with which cell suspensions may be produced from the olfactory epithelium, and emphasizes the importance of utilizing both biochemical and histochemical approaches in studies of mixed populations of cells, particularly when the purity of the cell fractions is a consideration.


Locomotor activity initiated by microinfusions of picrotoxin into the ventral tegmental area. Ambulatory activity in rats was increased in a dose-related manner by microinjections of picrotoxin, a GABA antagonist, bilaterally into the ventral tegmental area. Microinjections of strychnine, a glycine antagonist, had no effect on activity. The ambulatory activity induced by microinjections of picrotoxin into the ventral tegmental area was significantly attenuated when the nucleus accumbens was pretreated with spiroperidol, a dopamine antagonist. These findings provide additional evidence that dopaminergic (A10) neurons projecting from the ventral tegmental area to the nucleus accumbens, contribute to locomotor activity. It is suggested that picrotoxin disinhibits the A10 dopaminergic neurons projecting to the nucleus accumbens.


Noradrenaline and avoidance learning in the rat. The selective neurotoxin 6-hydroxydopamine was used to deplete forebrain noradrenaline to less than 5% of control values and the learning capabilities of the depleted animals examined on a two-way active avoidance task. Noradrenaline depleted animals learned the two-way active avoidance task more quickly than controls and required fewer training trials to reach acquisition criterion. Twenty-four hour retention was not altered by the lesion, but significant resistance to extinction was seen when electric footshock was no longer presented. More detailed analysis of the improved acquisition shown by the lesioned animals revealed that the major effect lay in a reduced freezing response to footshock. This freezing tended to slow down learning in the control animals, since it was incompatible with the required two-way active avoidance response. No alteration was seen in sensory detection thresholds for electric footshock or in spontaneous locomotor activity in the absence of shock. These results are discussed in relation to theories of noradrenaline function in learning and memory and, more recently, in fear and anxiety.


Rest and exercise hemodynamic studies in patients with isolated aortic stenosis. Hemodynamic data obtained during rest and exercise in 22 patients with aortic stenosis were analyzed. Mean aortic valve gradient for the group did not change significantly during exercise but there was large individual variability. Aortic valve flow increased during exercise in all but 2 patients. There was no correlation between change in gradient and change in flow during exercise. Although the mean calculated aortic valve area for the group did not change significantly during exercise, the calculated area was larger during exercise in most patients. Change in the calculated valve area correlated best with changes in aortic valve flow, left ventricular stroke work index, and the product of left ventricular systolic pressure and stroke volume. This suggests that in some patients there may be a dynamic component to aortic valve obstruction that may vary with changing hemodynamics.


Effects of sodium nitroprusside on function of regional ischemic myocardium. In the presence of regional myocardial ischemia, a 20% decrease in systemic arterial pressure following nitroprusside caused a 25% decrease in coronary perfusion pressure in animals with normal left ventricular end-diastolic pressures. This pressure decrement resulted in a significant decrease in the shortening of the regionally ischemic segment during the ejection phase of systole. A comparable arterial pressure drop of 21% with nitroprusside infusion during ischemia in the animals with elevated diastolic pressures caused a similar 28% decrease in coronary perfusion pressure, but resulted in a simultaneous increase in regional shortening. For the entire group there was no significant change in stroke volume. Even in the 11 animals where stroke volume increased, systolic regional shortening increased in only 4. An increase in stroke volume cannot be used to infer a parallel increase in the performance of a regionally ischemic segment. Nitroprusside appears to improve regional performance only in the presence of severe failure.


Drinking water quality and sudden death: observations from West and East Finland. Relationships of drinking water quality to CHD and sudden death were studied in two rural areas in western and eastern Finland. In the eastern area, drinking water is particularly soft and contains less magnesium and chromium but more copper than in the western area. A 15-year follow-up of resident males showed a higher death rate from CHD in the eastern area but no difference in the proportion of sudden deaths. The data suggest that CHD may be associated with low concentrations of magnesium and chromium in the drinking water, but no definite relationship was found between water quality and sudden death.


The relationship of mitral valve prolapse to obstructive coronary artery disease. A hemodynamic study. The relationship between mitral valve prolapse, segmental and total ventricular function was studied in 121 patients with severe coronary artery disease, 21 of whom had angiographically documented mitral prolapse. The position and movement of the inferior papillary muscle were also analyzed. Mitral valve prolapse in association with severe coronary artery disease does not worsen left ventricular function, nor is it related to ischemic wall motion abnormalities.


Electrophysiological effects of disopyramide in patients with bundle branch block. Electrophysiological studies were performed in 22 patients with intraventricular conduction delay before and after intravenous infusion of disopyramide (Norpace), 2 mg/kg. Mean control maximal sinus node recovery time (1039 +/- 187 msec), atrioventricular nodal conduction time (113 +/- 28 msec), and atrioventricular nodal effective refractory periods (349 +/- 67 msec) did not change significantly after administration of disopyramide (1073 +/- 284 msec, 112 +/- 31 msec, and 342 +/- 42 msec, respectively). Mean spontaneous cycle length (756 +/- 146 msec) decreased significantly 5 minutes after disopyramide (717 +/- 124 msec) (p less than 0.05), but not after 30 minutes (734 +/- 142 msec). A small but statistically significant (p less than 0.05) increase occurred after disopyramide in the mean atrial effective refractory period (259 +/- 51 to 280 +/- 53 msec), ventricular effective refractory period (253 +/- 23 to 275 +/- 33 msec), as well as the relative refractory period of the ventricular specialized conduction system (six patients) 433 +/- 78 to 479 +/- 62 msec). Although mean control infranodal conduction time (67 +/- 35 msec) increased 5 minutes after disopyramide (79 +/- 41 msec) (p less than 0.001) (18%), no spontaneous episodes of second-degree or third-degree atrioventricular block were observed. In six patients with premature ventricular depolarizations (greater than or equal to 1/min), the arrhythmia was totally abolished in four, markedly reduced in one, and remained unchanged in one. Disopyramide resulted in significant prolongation of infranodal conduction time as well as in atrial and ventricular refractoriness, but nevertheless appears to be safe in patients with bundle branch block.


Electrophysiologic effects of disopyramide phosphate on sinus node function in patients with sinus node dysfunction. The electrophysiologic effects of intravenously administered disopyramide (2 mg/kg) on three parameters of sinus node function were examined in 16 symptomatic patients with sinus node dysfunction. Based on their ECG data before study, patients were subdivided into group A (n = 8), those with sinus pauses and/or sinoatrial (SA) exit block; and group B (n = 8), those with sinus bradycardia. Disopyramide shortened spontaneous cycle length in 10 of 16 patients and lengthened it in six--markedly so (91%) in one patient. Estimated SA conduction time decreased in seven of 14 patients and increased in seven. Two patients developed second degree SA exit block after disopyramide. Maximum sinus node recovery time was prolonged by disopyramide in 11 of 16 patients and markedly so in four. For the group as a whole there was no significant difference in spontaneous cycle length, maximum sinus node recovery time or estimated SA conduction time. P-wave and QRS durations and H-V intervals were significantly lengthened by disopyramide. Marked depression of the three parameters of sinus node function occurred in three group A patients and in one group B patient who had persistent severe sinus bradycardia. These four patients also had secondary pauses after termination of rapid atrial pacing under control conditions. Disopyramide should be administered cautiously to patients with sinus node dysfunction, particularly those with sinus pauses, SA exit block or secondary pauses.


Incidence and site of atrioventricular block in patients with chronic bifascicular block. Four hundred fifty-two patients with chronic bifascicular block and initially intact atrioventricular (AV) conduction were detected, studied, and prospectively followed between January 1970 and March 1978. There were 360 males and 92 females, ages 18--93 years (mean +/- SD, 62 +/- 15 years). Follow-up ranged from 29-2804 days (mean 1066 +/- 97 days). AV block (2 degrees or 3 degrees) developed in 29 patients, nine with apparent cause and spontaneously in 20. Cumulative annual incidence of all heart block for 1--5 years was, respectively, 4%, 5.9%, 8.7%, 10.1% and 11.3%, and for spontaneous block was 2%, 3.1%, 5.2%, 6.7%, and 7.1%. Sites of spontaneous block were probably or definitely AV nodal in ten, His bundle in one, and trifascicular in nine. Cumulative incidence of AV block in surviving bifascicular block patients is 11% at 5 years, with 7% reflecting spontaneous block. The probable or definite site of AV block varies and is trifascicular in less than half of the patients. The small incidence of trifascicular block probably explains the difficulty in predicting this complication with electrophysiological studies.


Cellular electrophysiology of human myocardial infarction. 1. Abnormalities of cellular activation. Ventricular tissues were obtained at the time of operation from 12 patients who underwent aneurysmectomy or mitral valve replacement. The electrophysiologic characteristics of these tissues were determined in a tissue bath using microelectrodes. Normal-appearing action potentials were recorded from surviving Purkinje fibers and ventricular muscle cells within infarcted ventricular tissues. Normal muscle action potential recordings from infarcted tissues were similar to action potentials from noninfarcted papillary muscles, except that the duration of the action potential was significantly longer in the former. In other areas slow response potentials were recorded. These action potentials conducted slowly and were eliminated by verapamil. We observed verapamil-sensitive slow response automaticity, but this did not correlate with ventricular tachycardias, present in three patients. Variable amplitude responses arising from normal resting potentials and characterized by stimulus intensity-dependent changes in action potential amplitude were recorded in tissues from two patients. These potentials had many characteristics similar to the slow response, but were not eliminated by verapamil. We also saw inexcitable cells with both normal and abnormal resting potentials. The heterogeneous electrophysiologic characteristics of these tissues provide a likely substrate for arrhythmias and may be the source of the ectopic ventricular rhythms observed in these patients.


Clinicopathologic findings in 52 patients studied by technetium-99m stannous pyrophosphate myocardial scintigraphy. Scintigraphic, clinical and pathological findings were correlated in 52 patients studied by technetium-99m stannous pyrophosphate (99mTc-PYP) myocardial scintigraphy before death or surgical resection of myocardium. Fifty-nine clinical events were studied with scintigraphy in the 52 patients; 41 of the 59 were associated with one or more abnormal 99mTc-PYP studies and 18 with normal 99mTc-PYP scintigrams. Myocardial scintigrams were positive in 29 of 31 cases with clinicopathological evidence of a corresponding discrete, grossly obvious acute myocardial infarct, including 16 of 16 transmural myocardial infarcts and 13 of 15 subendocardial infarcts. In 16 of 18 cases, negative myocardial scintigrams correlated with the absence of acute myocardial infarction determined by clinicopathological evidence. In two cases small subendocardial infarcts (less than 3 g) were not detected by 99mTc-PYP myocardial scintigraphy. Of the 12 additional instances of positive 99mTc-PYP myocardial scintigrams, five were associated with clinical unstable angina pectoris and seven were in the category of persistently positive scintigrams, since the scans were obtained 2.5 months or longer after proven or suspected acute myocardial infarcts. In all 12 instances, the positive 99mTc-PYP scintigrams were associated with evidence of multifocal irreversible myocardial damage consisting of myocytolysis, coagulation necrosis and/or fibrosis, and the histological age of the lesions was compatible with acute injury corresponding to the time of scintigraphy. The findings indicate that a positive 99mTc-PYP myocardial scintigram is a sensitive indicator of significant myocardial injury which may occur as confluent coagulation necrosis corresponding to clinical acute myocardial infarction, or as multifocal coagulation necrosis or myocytolysis associated with unstable angina pectoris or recurrent ischemic heart disease, especially after previous infarctions.


Detection of myocardial infarct extension by CK-B radioimmunoassay. Myocardial infarct extension after the acute event was defined as a second reise in the myocardial isoenzyme of serum creatine kinase (CK-B) after the initial return of CK-B to normal values. In 43 patients with acute myocardial infarcts, CK-B was measured by radioimmunoassay every 12 hours for 14 days. Nineteen patients had anterior transmural myocardial infarcts AMI, 14 had inferior transmural myocardial infarcts (IMI) and 10 had subendocardial myocardial infarcts (SEMI). Infarct extension as detectd by a second rise in serum CK-B occurred in six patients (32%) with AMI, two (14%) with IMI and two (20%) with SEMI; these differences are not statistically significant. Infarct extension for all patients combined was 23%. Four patients with AMI also had infarct extension as determined by recurrent chest pain. ECG alterations and other enzyme changes. In the other six, the infarct extension was undetected clinically. Four patients with AMI and infarct extension died within 3 weeks after hospitalization. We did not note any additional morbidity or mortality in patients with infarct extension who had IMI or SEMI. There was no significant difference in the frequency of previous myocardial infarction, history of hypertension, diabetes mellitus or smoking history in patients with and without infarct extension shown by serum CK-B isoenzyme elevations. The measurement of serum CK-B values with a quantitative and sensitive assay suggests that myocardial infarct extension occurs more commonly than clinically recognized, but the frequency of extension may be less than that reported in patients in whom precordial mapping and total serum CK values were measured to identify this phenomenon.


Reduction of myocardial infarct size: comparison between left atrial and left ventricular bypass. A controlled study was undertaken to quantitate and compare the effect of left ventricular bypass (LVB) and left atrial bypass (LAB on left ventricular infarct volume (LVIV). After baseline studies, the left anterior descending coronary artery in each of 30 mongrel dogs was ligated 1-1.5 cm from its origin. After baseline ischemic studies, control dogs (group 1--10 dogs), LAB dogs (group 2--10 dogs), and LVB dogs (group 3--10 dogs) were monitored for four hours. Final infarct size was determined by the nitroblue tetrazolium staining technique. Heart rate, mean arterial pressure, and total systemic flow (TSF) showed no significant difference between control and left heart bypass groups. In group 1, the LVIV was 27.7 +/- 6.5 g/100 g left ventricle (LV). In group 2, left heart bypass (LHB) flow was 90 +/- 4% of TSF. The pressure time index (PTI) was 2845 +/- 52 mm Hg-sec/min. The PTI demonstrated no significant difference from cntrols. In group 2, LVIV was 22.5 +/- 6.0 g/100 g LV. LVIV was reduced 18.8% from controls (p less than 0.08). In group 2, LHB was complete. Left ventricular decompression (group 3) resulted in a PTI of 328 +/- 76 mm Hg-sec/min. The PTI was significantly different (p less than 0.001) from groups 1 and 2. The LVIV was 12.6 +/- 5.1 g/100 g LV. LVIV was reduced 54.5% from controls (p less than 0.001) and 44.0% from group 2 (p less than 0.001). These results suggest that LVB may be useful, not only in supporting the circulation in the patient with myocardial infarct and cardiogenic shock, but also in limiting infarct size.


Use of treadmill score to quantify ischemic response and predict extent of coronary disease. In this study we assessed whether various responses to exercise testing could be quantified in order to derive the probabilities of presence of coronary disease, and if present, to assess its severity. A treadmill score based on the exercise response was determined in 405 patients who had both treadmill tests and coronary angiograms. The score was derived using discriminant function analysis, by weighting and combining depth and configuration of ST depression (downsloping, horizontal or slowly upsloping), timing onset and duration of ischemia, grading ventricular arrhythmias, heart rate and blood pressure change, coexistence of exercise-induced chest pain and sex. The treadmill score was effective in detecting coronary disease (lesions with an greater than or equal to 50% narrowing), with a predictive accuracy (PA) (probability that a subject manifesting a positive test has disease) of 87%, a true negative rate (TNR) (probability of a subject with a negative test having no disease) of 80%, and sensitivity of 94%. The treadmill score also detected severe disease (triple-vessel, main left and/or greater than 90% proximal occlusion of the left anterior descending artery), with a PA of 73%, TNR of 79% and sensitivity of 82%. We conclude that the exercise response, expressed numerically as a treadmill score, permits analysis of most of the relevant data from exercise testing, increases test accuracy by 10-15% compared with standard criteria for treatmill test interpretation, and enables the derivation of probability statements for presence and severity of coronary disease. The validity of any prediction on the basis of exercise performance may thus be quantitatively judged.


The syndrome of variant angina culminating in acute myocardial infarction. Ten patients 28-54 years old with recurrent attacks of variant angina (chest pain associated with transient ST-segment elevation) culminating in acute myocardial infarction were studied. Systemic blood pressure and heart rate remained unchanged or decreased during chest pain. Diagnosis of myocardial infarction was made on the basis of pathognomonic enzyme changes and T-wave inversions persisting for several weeks (seven patients) or development of Q waves (three patients). Complications were similar to the ones previously observed in conventional myocardial infarction. None of these patients died. Past history was characterized by absence of effort angina. Exercise stress testing after infarction was normal, and coronary arteriography revealed a spectrum of pathology, ranging from normal arteriograms to three-vessel disease. Intraaortic balloon pumping was ineffective in two patients, but subsequent coronary bypass surgery shortly after myocardial infarction was not followed by further attacks of chest pain. Follow-up of these patients revealed a benign course. Alcohol drinking and cigarette smoking appeared to be very prevalent in this group.


Increased coronary mortality in relatives of hypercholesterolemic school children: the Muscatine study. From 2,874 school children participating in the 1971 and 1973 Muscatine Coronary Risk Factor Survey, we selected three groups of index cases for detailed family study: the HIGH group (n = 56), with cholesterol levels greater than the 95th percentile twice; the MIDDLE group (n = 46), cholesterol levels between the 5th and 95th percentile; and the LOW group (n = 46), cholesterol levels less than the 5th percentile twice. Coronary mortality determined from death certificates was increased in the young relatives (ages 30-59) of the HIGH group index cases, as follows: twofold excess in HIGH male relatives compared with the MIDDLE or LOW group (p less than 0.05); tenfold excess in the HIGH female relatives compared with the MIDDLE and LOW group combined (p less than 0.01). After correction for years at risk, there was an approximately twofold significantly-increased coronary mortality. Stroke mortality was higher, although not significantly, in the older relatives (ages greater than or equal to 60) of the HIGH index cases. Cancer mortality was not significantly different among the relatives of the three groups of index cases. This study indicates that school children's cholesterol levels cluster with those of their family members and that persistent hypercholesterolemia in children identifies families at risk for coronary artery disease.


A collaborative study of infective endocarditis in the 1970s. Emphasis on infections in patients who have undergone cardiovascular surgery. Twenty-six major cardiovascular centers participated in a cooperative study of all cases of infective endocarditis occurring during a single calendar year to obtain an overview of infective endocarditis. The study was designed to learn which patients appear to be at highest risk to develop this infection after palliative or reparative cardiovascular surgery. Of 278 patients developing infective endocarditis during the year at these medical centers, 63 (23%) had had previous cardiovascular surgery and 215 had not. Seventy percent of the 278 patients had recognized congenital or acquired heart disease before developing the infection. Rheumatic heart disease accounted for over half of the patients with underlying structural heart disease. A majority (55%) of the 63 patients who had been operated on before developing endocarditis had prosthetic valves inserted. Of those who did not require prosthetic valves, the majority had congenital heart disease with systemic artery-to-pulmonary artery shunts. Although these data were obtained from a selected group of patients, they confirm a significant risk of endocarditis in patients with prosthetic valves and suggest that in postoperative patients with non-valvular congenital heart disease, the highest risk appears to be in cyanotic patients with palliative pulmonary artery-to-systemic artery shunts.


Imaging experimental infective endocarditis with indium-111-labeled blood cellular components. The capability of radionuclide imaging to detect experimental aortic valve infective endocarditis was assessed with indium-111 (111In)-labeled blood cells. Sequential cardiac imaging and tissue distribution studies were obtained in 17 rabbits with infective endocarditis after administration of 111In-platelets and in five after 111In-polymorphonuclear leukocytes. Forty-eight to 72 hours after platelet administration, in vivo imaging demonstrated abnormal 111In uptake in all animals in the region of the aortic valve in an anatomically distinct pattern. Images of the excised heart showed discrete cardiac uptake conforming to the in vivo image and gross pathological examination. 111In platelet uptake in vegetations from the 17 animals averaged 240 +/- 41 times greater than that in normal myocardium and 99 +/- 15 times greater uptake in blood. In contrast, 111In-leukocyte cardiac imaging showed no abnormal aortic valve uptake 24 hours after tracer administration and the lesion myocardium activity ratio was only 5 +/- 2 (3 +/- 1 for lesion/blood activity). Four normal rabbits demonstrated neither positive 111In platelet scintigraphs nor abnormal cardiac tissue uptake. Likewise, noncellular 111In was not concentrated to any significant extent in three animals with infective endocarditis. This study demonstrates that 111In platelet, but not leukocyte cardiac imaging, is a sensitive technique for detecting experimental infective endocarditis. The imaging data conform to the cellular pathology of the infective endocarditis vegetation.


Deep venous thrombosis of the upper extremity: a reappraisal. Deep venous thrombosis (DVT) of the upper extremity is an unusual thrombotic event (1-2% of all DVT) which can be conveniently divided into two categories, traumatic (including "stress") and spontaneous. The spontaneous form is not reported as often in the literature, but occurs more commonly than the traumatic form. There is an increased left-sided predominance in spontaneous DVT compared with the traumatic form, where a right-sided predominance exists. Possible anatomical and physiological explanations are offered for the left-sided predominance in spontaneous DVT of the upper extremity. The thrombogenesis of DVT of the upper extremity is compared with DVT of the lower extremity. An analysis of responses to therapy and considerations for other therapeutic approaches are offered.


Clinically practical lead systems for improved electrocardiography: comparison with precordial grids and conventional lead systems. The use of limited leads for estimating total body surface potential distributions was investigated as a practical solution to the problem associated with extensive electrocardiographic sampling used in surface potential mapping. Two practical, limited lead sets of 32 leads each were derived and contrasted to a set of 30 precordial leads similar to those used in ST-segment and QRS mapping for estimating infarct size, and to a set of nine leads simulating those used in conventional 12-lead examinations. The two arrays, one of which excluded posterior sites for use in recumbent patients, showed little difference in ability to estimate 192 lead measured maps (average rms voltage error of 35 muV and average correlation coefficient of 0.97). The 30- and 9-lead arrays consistently showed twice the voltage (72 muV) and poorer pattern estimation (average correlation coefficient of 0.91) than either of the 32 lead arrays. These findings indicate the need for 20-35 properly located electrodes for accurate total body surface potential estimation. They also show that there is no difference in the abilities of a 30-lead precordial array and conventional leads to estimate maps.


Reaction of the myocardium to cryosurgery: electrophysiology and arrhythmogenic potential. The acute and chronic electrophysiological effects of a cryolesion produced in the left ventricle were studied in six dogs. All dogs had frequent ventricular premature beats (VPB) and five of six dogs had ventricular tachycardia during the first 4 days after the cryolesion; only one of the six dogs continued to have VPBs after 1 week, and this dog had identical VPBs before the creation of the cryolesion. Neither control dog had VPBs. Two additional dogs underwent epicardial and transmural mapping studies immediately after production of a cryolesion. VPBs in these animals were shown to originate at the border of the cryolesion. Epicardial activation sequence during normal sinus rhythm was not altered by the chronic cryolesion. The border zone of the chronic cryolesion was sharply demarcated with normal potentials recorded outside of the lesion and "extrinsic" potentials recorded within.


Contrast M-mode echocardiography in diagnosis of atrial septal defect in acyanotic patients. Contrast echocardiograms during normal quiet respiration and during the Valsalva maneuver were performed in 15 patients with atrial septal defect (ASD) by injecting saline solution into an antecubital vein. Contrast shunting (the appearance of contrast echoes in the left heart) was observed not only in four patients with severe pulmonary hypertension (group 2), but also in 11 patients with uncomplicated ASD (group 1). Contrast shunting was prominent in all group 2 patients. In group 1, contrast shunting was sometimes subtle and difficult to recognize, but at other times was very obvious and similar to the findings in group 2. Contrast shunting was generally more pronounced during the Valsalva maneuver than during normal respiration, although there were exceptions. The amount of contrast appearing in the left heart did not correlate with the size of the defect. Small right-to-left shunts which are clinically insignificant but detectable by contrast echocardiography are present, or can be provoked by the Valsalva maneuver, in most patients with ASD. Contrast echocardiography is a useful, noninvasive method to detect interatrial communication, even in acyanotic patients.


Detection and exclusion of interatrial shunts by two-dimensional echocardiography and peripheral venous injection. Two-dimensional echocardiography (2-D echo) was used with peripherally injected contrast material to detect interatrial shunts in 33 patients. Group 1 consisted of 11 patients having classic clinical findings of atrial septal defect. Group 2 consisted of 12 patients with problems requiring that atrial shunting be excluded. Group 3 (control group) consisted of 10 patients undergoing cardiac catheterization for chest pain. Confirmation of the 2-D echo findings was provided by cardiac catheterization in 32 patients and postmortem examination in one. Right-to-left atrial shunts were detected in all 11 patients in group 1, although seven had no right-to-left shunt calculable by oximetry. Four patients in Group 2 had right-to-left atrial shunts. None of the patients in Group 3 had atrial shunts. In the 15 patients with atrial shunts, the degree of right-to-left shunting could be qualitatively assessed as small, moderate, or large. There were no false-negative or false-positive results by contrast 2-D echo.


Ventricular septal defect in infancy: a combined vectorgraphic and echocardiographic study. Echocardiograms (echo) and vectorcardiograms (VCG) from 40 infants with ventricular septal defects (VSD) were compared with cardiac catheterization data to assess noninvasively the hemodynamics of VSD. The specific aim was to use VCG parameters of right ventricular hypertrophy and echo parameters which reflect pulmonary artery pressure to identify all patients with a nonrestrictive VSD. The configuration of the QRS vector in the horizontal plane was more reliable than individual voltages in assessing right ventricular systolic pressure. Among patients older than 2 months with a clockwise or anterior two-main-vector horizontal loop, 73% (eight of 11) had a nonrestrictive VSD. However, a counterclockwise or posterior two-main-vector loop was also frequently found (43%, six of 14) in infants with a nonrestrictive VSD. The most useful echo parameter was the ratio of right ventricular preejection period-to-right ventricular ejection time (RPEP/RVET), which closely (r = 0.74) reflected the pulmonary artery diastolic pressure. An elevated RPEP/RVET to greater than 0.30 was always associated with a nonrestrictive VSD, although many patients (36%, five of 14) with a nonrestrictive VSD had a normal ratio. By combining both echo and VCG parameters, a nonrestrictive VSD was correctly identified in all patients, while a restrictive VSD was correctly identified in 81% (21 of 26).


Right ventricular outflow tract assessment by cross-sectional echocardiography in tetralogy of Fallot. Cross-sectional echocardiographic (CSE) studies were obtained in 29 children with tetralogy of Fallot. In this study we evaluated the capability of CSE to record the right ventricular outflow tract (RVOT) and compared the severity of infundibular obstruction determined by CSE with cineangiographic (cine) determinations. In addition, we examined capabilities of CSE and M-mode echocardiography (M-mode) to record the diagnostic features of tetralogy of Fallot, including RVOT obstruction, aortic overriding, ventricular septal defect, and presence of the pulmonary valve. An excellent correlation (r = 0.925) was found for the combined pre- and post-repair patients studied by CSE vs cine, while the correlation (r = 0.805) for M-mode was not as good. The difference was even more striking for the unrepaired patients, in which the correlation (r = 0.746) for CSE was much better than for M-mode (r = 0.374). In the unrepaired patients, CSE allowed easier detection of the ventricular septal defect than M-mode (95% for CSE vs 76% for M-mode). The pulmonary valve was recorded in 90% by CSE, but in only 26% by M-mode. Aortic overriding was recorded in all unrepaired patients both by CSE and M-mode. These data indicate that CSE is better than M-mode for recording the RVOT dimensions, ventricular septal defect, and the pulmonary valve in unrepaired patients with tetralogy of Fallot.


Univentricular heart of right ventricular type with double or common inlet. Seventeen cases are described in which both atria connect directly to a chamber with right ventricular characteristics. The atria connected through separate atrioventricular valves in six hearts and a common valve in 11. All hearts had a posterior rudimentary chamber. The septum which separated it from the main chamber was directed to the crux of the heart. Ten hearts were from patients with atrial situs solitus and seven from patients with atrial situs ambigous. Arterial connections were concordant in three cases, had a double outlet from the main ventricular chamber in nine and single outlet of the heart in five. The patent artery always arose from the main chamber, with pulmonary atresia in three and aortic atresia in two. This and other studies indicate that double inlet atrioventricular connection does not predict the morphology of the main chamber. Although usually associated with a main chamber of left ventricular type, it may also be associated with a main chamber having right ventricular characteristics. Both types should be considered as univentricular hearts; the posterior chamber in hearts of right ventricular type are analogous to the anterior chamber in univentricular hearts of left ventricular type and are a rudimentary chamber rather than a hypoplastic ventricle. In the right ventricular form of univentricular heart, the trabecular zone of the rudimentary chamber is of left ventricular type.


Centrifugal analyzer method for total bilirubin in serum by use of diazotized 2-chloroaniline-5-sulfonic acid. We describe two centrifugal analyzer methods for measuring total bilirubin in serum. Diazotized 2-chloroaniline-5-sulfonic acid is used in both. In the first procedure, ethylene glycol and methanol are used as an accelerator solvent; results correlate well with those by a Jendrassik and Grof method adapted to the centrifugal analyzer, but there is considerable hemolysis interference. In the second method, dimethyl sulfoxide is used with the ethylene glycol/methanol solvent and almost all hemolysis interference is eliminated. For either method, a 15-microliter sample is required. In the second method, instrument response is linearly related to concentration to 250 mg/L and the within-run precision (CV) is about 1%.


Thin-layer agarose electrophoresis of lactate dehydrogenase isoenzymes in serum: a note on the method of reporting and on the lactate dehydrogenase isoenzyme-1/isoenzyme-2 ratio in acute myocardial infarction. We assessed the clinical efficacy of a thin-layer agarose electrophoresis assay for lactate dehydrogenase isoenzyme estimation in the diagnosis of acute myocardial infarction. From a population of 228 patients admitted to the Coronary Care Unit with suspected acute myocardial infarction, all 101 positive cases (confirmed by clinical presentation and electrocardiographic changes) were correctly identified with lactate dehydrogenase isoenzyme-1 percentage of total activity above the reference range and with a lactate dehydrogenase isoenzyme-1/isoenzyme-2 ratio of 0.76 or above. This ratio was between 0.45 and 0.74 for 250 healthy subjects. No falsely negative, but 12 falsely positive results were obtained from this Coronary Care Unit population, to give a sensitivity of 100% and a specificity of 90.5% for the ratio test.


Analysis for underivatized theophylline by gas-chromatography on a silicone stationary phase, SP-2510-DA. I describe a flame-ionization gas-chromatographic method for the quantitative analysis of serum theophylline without the need for derivatization. The analysis is performed isothermally on a new silicone stationary phase, 2% SP 2510-DA (Supelco). With this liquid phase, gas-chromatographic properties and sensitivities are comparable to methods requiring derivatization. A salt-solvent pair of ammonium sulfate and methylene chloride/hexane/acetic acid (80:20:0.1 by vol) is used for extraction. Ammonium sulfate greatly reduces co-extractable interferences from icteric, lipemic, and hemolyzed serum. The density of methylene chloride is adjusted with hexane so that the solvent is less dense than the salt-saturated serum and can be removed by decanting. Acetic acid, used to adjust the pH of the serum samples, is combined with the extraction solvent rather than being added individually to the serum samples. Theophylline values obtained by this method agree closely with those determined by enzyme immunoassay (correlation coefficient, 0.988).


Gas-liquid chromatographic determination of mono- and diiodotyrosines in serum. A sensitivie, reliable gas-chromatographic assay for monoiodotyrosine and diiodotyrosine in human serum is reported. The oxazolidinone-heptafluorobutyric anhydride derivatives allow the quantitation of both compounds in the linear range of 0.2 to 7.6 mg/L of serum. Analytical recovery averaged 88%, and mean accuracy and within-run precision were 98 and 2%, respectively. Concentrations of monoiodotyrosine in serum as low as 20 microgram/L and of diiodotyrosine as low as 100 microgram/L can be detected. Normal serum contains no detectable concentration of either compound, but the method is applicable as a diagnostic tool in the early prediction of thyroid disease. Both compounds were detected in the serum of a hypothyroid subject whose normal thyroid hormone concentrations were being maintained by therapy with desiccated thyroid extract.


Analysis for urinary catecholamines by liquid chromatography with amperometric detection: methodology and clinical interpretation of results. A method is presented for the quantitative analysis of urinary unconjugated norepinephrine, epinephrine, and dopamine as discrete entities. The procedure requires initial purification of the specimen on aluminum oxide and a boric acid-gel. We used "high-performance" reversed-phase paired-ion chromatography, with a flow-through amperometric cell as the detector. The CV was 6% for determination of norepinephrine, 11% for epinephrine, and 6% for dopamine monitored at physiologic concentrations of these compounds in urine. In a population study, urine specimens from 117 normal pediatric and adult subjects, 85 hypertensive patients, and 22 patients with surgically proved pheochromocytoma were analyzed. The specificity of the method for detection of pheochromocytoma was 100%, with a sensitivity of 97%.


Radioimmunoassay of conjugated cholic acid, chenodeoxycholic acid, and deoxycholic acid from human serum, with use of 125I-labeled ligands. We describe a method for radioimmunoassay of conjugated cholic acid, chenodeoxycholic acid, and deoxycholic acid in serum. In the method, 125I-labeled bile acid conjugates are used as the tracers along with antibodies raised against individual bile acid-bovine serum albumin conjugates. Antibody-bound and free bile acids were separated by polyethylene glycol precipitation (final concentration, 125 g/L). Before radioimmunoassay, 0.1-mL serum samples were precipitated with nine volumes of ethanol, and portions from the supernate were used in the assays. The lowest measurable amounts of the bile acids, expressed as pmol/tube, were: cholic acid conjugates, 2; chenodeoxycholic acid conjugates, 0.5; and deoxycholic acid conjugates. 2. Analytical recovery of bile acids added to bile acid-free serum ranged from 85 to 110%; intra-assay and inter-assay CVs ranged from 3.2 to 5.3% and from 5.3 to 12.2%, respectively. Concentrations (mean +/- SD) of the bile acid conjugates in serum from apparently healthy women and men (in mumol/L) were: cholic acid conjugates, 0.43 +/- 0.17 (n = 126); chenodeoxycholic acid conjugates, 0.47 +/- 0.23 (n = 111); and deoxycholic acid conjugates, 0.33 +/- 0.11 (n = 96). The values for primary bile acids were greatly increased in patients with various hepatobiliary diseases.


Manual and continuous-flow colorimetry of triacylglycerols by a fully enzymic method. We describe a fully enzymic method for manual and continuous-flow colorimetric assay of triacylglycerols (triglycerides) in serum. Triglycerides are enzymically hydrolyzed in 10 min by lipase and microbial esterase. The resulting free glycerol is measured enzymically by glycerol kinase and glycerol-3-phosphate dehydrogenase. The NADH so formed is oxidized by coupling with a tetrazolium salt/diaphorase system. The test follows Beer's law to 8 g/L, and the final color is stable for at least 1 h for serum, 15 min for aqueous triolein standards. The manual assay requires only 25 microliter of serum and few manipulations. A specific triolein standard was developed for calibrating the manual method. For the continuous-flow method, calibration is made with four concentrations of glycerol standard. The procedure is sensitive, has good precision and accuracy, and gives results that compare well with chemical and enzymic commercial kit methods.


Single- and coupled-enzyme nylon tube reactors for routine determination of pyruvate and lactate in serum. We describe the use of a continuous-flow clinical analyzer with an immobilized coupled-enzyme nylon tube reactor and an immobilized single-enzyme nylon tube reactor for routine estimation of lactate and pyruvate in serum. These reactors are incorporated into the flow system of a modified continuous-flow analyzer (Technicon AutoAnalyzer). Results for serum lactate and pyruvate by this method are compared with those by corresponding methods in which the same enzymes are used in solution, either automatically (pyruvate) or manually (lactate) performed. Routine clinical laboratory determinations with use of the coupled-enzyme system lactate dehydrogenase and alanine aminotransferase, co-immobilized in the nylon tube reactor for estimation of lactate, and lactate dehydrogenase reactors for estimation of pyruvate give reliable and reproducible results with high precision at low cost.


Stability of dilute solutions of gentamicin and tobramycin. Dilution of sera containing gentamicin or tobramycin in glass containers results in substantial adsorption of the antibiotic to the surface of the container, which can be prevented if acidic or basic solutions are used to dilute such sera. We describe protocols for radioimmunoassays of gentamicin and tobramycin that include solutions and containers that obviate this problem.


Assays for chloramphenicol compared: radioenzymatic, gas chromatographic with electron capture, and gas chromatographic-mass spectrometric. We compared these three techniques for measuring chloramphenicol in serum or urine. Although each has its particular advantages, any of them is shown to be satisfactory and may appropriately be used by clinical laboratories, according to the facilities available.


Four kits for plasma digoxin radioimmunoassay compared. We evaluated four commercial radioimmunoassay kits for digoxin. We assayed a standard plasma containing digoxin, 2.0 microgram/L, and samples from patients receiving digoxin, with use of the kits and of a bioassay, the 86Rb-uptake inhibition technique. Intra-assay precisions differed significantly. Computer-calculated 95% confidence intervals for the radioimmunoassays averaged 0.4 to 0.6 microgram/L at the proposed toxic threshold of 2.0 microgram/L; the corresponding value of the 86Rb assay was 0.75 microgram/L. Digoxin in the standard plasma was overestimated with three of the kits (means: 2.40, 2.56, and 2.59 microgram/L) but was assayed accurately by the 86Rb technique and by one kit. This same kit gave a significantly lower mean (1.07 microgram/L) for the patients' samples then did the other three kits (1.32, 1.49, and 1.29 microgram/L), two of which also differed significantly in accuracy. The 86Rb assay measured glycoside activity corresponding to a mean digoxin concentration of 1.35 microgram/L. We conclude that the relatively low precision of digoxin assay and the variations in accuracy between kits from various vendors apparently deserve continual attention.


Phthalate interference in gas-chromatographic determination of long-chain fatty acids in plasma. Phthalates leached from plastic tubing or other plastic devices may interfere with gas-chromatographic determination of long-chain fatty acids in plasma. In the case of hospitalized patients who have received infusions or had blood drawn through plastic tubing, gas chromatography/mass spectrometry may be required for accurate determination of such fatty acids.


Gas-chromatographic determination of disopyramide in serum, with use of a nitrogen-selective detector. In this procedure for disopyramide in serum, the drug is extracted into n-heptane/isobutanol (96/4 by vol), then back-extracted into 1 mol/L H2SO4. The acidic solution is made basic with sodium hydroxide, extracted with diethyl ether, and the extract evaporated. The residue is redissolved in ethanol and analyzed by gas-chromatography, with use of a nitrogen-selective detector. p-Chlorodisopyramide is used as internal standard. Concentration and instrument response for serum extracts are linearly related from 1 to 5 mg/L, the slope being 0.61, the y-intercept -0.10, the standard error of estimate 0.01, and the correlation coefficient 0.99. Within-run precision was 6 and 4% for 3 and 5 mg/L concentrations, respectively, with a between-run precision of 7% at the 3 mg/L concentration. Diazepam interferes, but procainamide, chlordiazepoxide, quinidine, lidocaine, propranolol, sulfanilamide, and many other basic drugs do not.


Improved indirect and direct radioimmunoassay for carcinoembryonic antigen. Values obtained by the indirect and the direct assays for carcinoembryonic antigen by use of the "CEA Roche" method and reagents differ significantly. In 32 samples the latter method gave values almost twofold those obtained by the former. The mean ratio for direct/indirect was 1.9 +/- 0.6. Analytical recovery experiments on samples to which known amounts of the antigen had been added showed a similar disparity. A simple modification of these two procedures, involving addition of normal human plasma (containing less than 2.0 microgram of the antigen per liter) to standards, eliminated this discrepancy. In the indirect method, standards were added to normal human plasma, then extracted with perchloric acid before assay. In the direct assay normal human plasma instead of goat serum, was added to standards. With these modifications the analytical recoveries of added CEA by the indirect and direct methods were 87 +/- 17% and 99.7 +/- 8%, respectively, and the mean ratio between two methods was 1.2 +/- 0.4.


Continuous-flow fluoroimmunoassay of serum gentamicin, with automatic sample blank correction. We describe the continuous-flow automation of a quenching fluoroimmunoassay for determination of the antibiotic gentamicin in serum. In the flow system, sample is mixed with fluorescein-labeled gentamicin, followed by antiserum, and after a short incubation the fluorescence is measured. The intrinsic blank signal of each sample is corrected for during its single passage through the system by pumping antiserum discontinuously, so as to divide the final stream into sections corresponding to conventional separate assay and blank mixtures. Analyses time for each sample is 6 min, and 20 samples can be run per hour. Sensitivity, precision, and accuracy are adequate for clinical purposes, and assays of patients' samples correlate satisfactorily with the results of manual quenching and polarization fluoroimmunoassays, and plate diffusion bioassay.


Folic acid dependent hypersarcosinaemia. Hypersarcosinaemia is a rare inborn error of metabolism, caused by a deficiency of the sarcosine dehydrogenase complex with tetrahydrofolate as a formaldehyde acceptor needed for the sarcosine-glycine conversion. Prolonged therapy with folic acid on a hypersarcosinaemic patient resulted in a significant effect on the urinary excretion of sarcosine, leading to the conclusion that the patient has a folic acid dependent hypersarcosinaemia.


Lysosomal damage by gliadin and gliadin peptides; an activity not related to coeliac disease. Rat-liver lysosomes have been used to determine the toxicity of gliadin fractions in relation to coeliac disease. In this study we compared the activity in acid phosphatase release from rat-liver lysosomes by casein, gliadin and by their peptic-tryptic digests. The release of acid phosphatase is not specific for gliadin.


A method for the evaluation of 3-hydroxyproline in the urine. After hydrolysis of the urine by 6 M HCl, 3-hydroxyproline is purified from many interfering substances by 2 steps of chromatography on Dowex 1 X8 resin equilibrated first in the acetate form and secondly in the OH- form. The amino acid is finally evaluated by chromatography on Dowex 50 M82 resin in a Beckman multichrom amino acid analyzer. In 23 normal adult subjects the mean level was 12.5 +/- 3.5 mumol/24 h. In 8 normal children the level was 6.0 +/- 5 mumol/24 h and in 8 teenagers 15.2 +/- 2.85 mumol/24 h. The ratio of 3-hydroxyproline to 4-hydroxyproline seems indicative of a semiological value of this evaluation in cases of basement membrane collagen deterioration.


A study of alkaline phosphatase isoenzyme electrophoresis on cellulose acetate compared with agar, agarose and acrylamide in the presence or absence of triton X-100. The application of Triton X-100 in cellulose acetate electrophoresis and its effects on the separation of serum alkaline phosphatases is described. The cellulose acetate electrophoretic patterns of serum alkaline phosphatase found in liver and bone disease have been compared with the patterns found in agar, agarose, and polyacrylamide gel in the presence and absence of Triton X-100 and the differences described and discussed. Changes in the alkaline phosphatase electrophoretic pattern and the effects on certain electrophoretic variants have been noted following addition of Triton X-100 to all parts of the system.


Fluorimetric assay for human intestinal glycine peptidases. A sensitive but simple fluorimetric assay for intestinal enzymes capable of hydrolysing certain glycine-containing peptides is described. In the standard assay, 1 nanomole of glycine can be accurately estimated in the presence of a 2000-fold molar excess of unhydrolysed peptide. Initial rates of peptide hydrolysis can be measured on the density gradient fractions obtained by analytical subcellular fractionation of extracts from milligram quantities of human jejunal tissue. Differences in the subcellular localisation of activity against two peptides are illustrated. The implications of these findings in relation to the study of intestinal peptidase deficiency in disease states are discussed.


Creatine kinase isoenzyme BB in serum of healthy adults and children. The activity of the creatine kinase isoenzyme BB was determined in the serum of 26 healthy adults and 31 children. The isoenzyme BB could be proved as a normal component in the human serum. In the adults examined, an activity of 0.56 +/- 0.16 I.U./l (x +/- S.D.) was determined. The activity of creatine kinase isoenzyme BB in the serum does not depend on sex but is subject, however, to a strong age dependence. Only at an age of more than 18 years, isoenzyme BB activities adjust to those of adults.


Determination of estrogen ring D glucuronides in pregnancy plasma by direct radioimmunoassay without hydrolysis. A direct radioimmunoassay method using highly specific antisera without prior deconjugation has been developed for determination of estradiol 17-glucuronide and estriol 16-glucuronide in human plasma. Antisera were elicited in the rabbit by immunization with antigens in which the steroid haptens are linked to a carrier protein through the C-2 or C-4 position. After treatment with Rivanol the protein of albumin-free antiserum was covalently bound to a p-arylamine glass bead support through the cross-linkage with glutaraldehyde. A simple and reliable assay method employing the antibody-glass preparation was established and applied to measurement of estrogen ring D glucuronide concentration in peripheral plasma throughout normal pregnancy.


[Microdetermination of fluoride in human bones (author's transl)]. A spectrophotometric method (cerium(III)-alizarin complexan-fluoride in presence of 25% dimethylsulfoxyde) is described for the determination of fluoride in human bones. The anion is determined after separation by microdiffusion as hydrofluoric acid using Petri boxes without any mineralization. This analytical method is selective, accurate and rapid.


Effect of dithiothreitol of the reaction of renin and angiotensinogen. Effects of several sulfhydryl reagents on the reaction of renin and angiotensinogen were investigated by measuring the production of angiotensin I. Renin and angiotensinogen were prepared from the kidneys of dogs and from plasma of nephrectomized dogs, respectively. The amount of angiotensin I generated was increased with application of dithiothreitol, dithioerythritol and 2,3-mercapto-1-propanol. The greatest enhancement of the generation of angiotensin I was observed with dithiothreitol. Dithiothreitol had no influence on renin activity, on radioimmunoassay for angiotensin I and the recovery of synthetic angiotensin I from the incubation medium. When heterologous angiotensinogen was used, a great enhancement of generation of angiotensin I was observed. Dithiothreitol did not accelerate the reaction following replacement of the natural substrate, angiotensinogen, with the synthetic tetradecapeptide as substrate. It is postulated that dithiothreitol augments angiotensin I generation by acting on the angiotensinogen and not on the renin.


Abnormal distribution of alpha-L-fucosidase in cystic fibrosis: decreased activity in serum. The activity of alpha-L-fucosidase is decreased in the serum of cystic fibrosis patients when compared to age-matched controls. This result, combined with the elevated activity in skin fibroblasts, supports the concept of an abnormal intracellular and extracellular distribution of alpha-L-fucosidase in cystic fibrosis.


Spectrophotometric plasma iron determination from fingerpuncture specimens. A simple, sensitive, precise and reproducible micromethod for the determination of plasma iron in a 50-microliter sample has been devised by modification of the ICSH reference procedure, which requires a 2-ml sample. The micromethod uses microcuvettes and substitutes ferrozine for the bathophenanthroline chromogen of the ICSH. Comparison of plasma iron values on 47 paired specimens obtained by fingerpuncture and venipuncture determined by the micro- and ICSH-methods respectively gave identical means of 15.8 mumol/l (88 microgram/dl); the correlation of the two methods was r = 0.92 (p less than 0.0001). The micromethod has been successfully used to measure plasma iron levels in fingerpuncture specimens collected in a field study of 429 children.


Human gene mapping by postreduction and recombination frequencies under complete interference. Gene-centromere distances can be estimated (i) by determining postreduction frequencies by means of ovarian teratomas and (ii) by analysis of genetic linkage between a gene locus and a structural chromosome polymorphism near the centromere. The two methods are comapred under complete interference. It is shown that the teratoma method is at least twice as efficient as the recombination method. Two estimates of the map distance for a combination of both data types are derived.


Chromosome breaks and sister chromatid exchanges in albinos in Nigeria. The prevalence of squamous cell carcinoma of the skin in albinos reaches approximately 90% in patients over 20 years of age in the vicinity of Enugu, Nigeria. Chromosome breaks and sister chromatid exchanges (SCE) were evaluated in tyrosinase-positive oculocutaneous albinos and pigmented controls of Ibo extraction who were life-long residents of Nigeria. No difference in the frequency of chromosomal breaks in 14 albinos compared to 6 pigmented controls, and no differences in the frequency of SCE in 9 albinos compared to 3 controls could be detected. Increased chromosomal abnormalities in lymphocytes do not appear to be assoicated with albinism or fulminating skin cancer present in albinos in the tropics.


No evidence for chromosomal mosaicism in multiple tissues of 10 patients with 45, XO Turner syndrome. Why the frequency of spontaneous abortions among monosomy X conceptuses is 98% while the postnatal course of Turner syndrome is relatively benign has not been understood. One explanation could be that mosaicism for a euploid cell line confers viability and that those 2% of 45,XO zygotes surviving in utero have some degree of mosaicism. We thus reasoned that if the non-mosaic 45,XO karyotype is lethal, a thorough study of living Turner syndrome patients might reveal a much higher frequency of mosaicism than the 30--40% reported. Ten adult women with a 45,XO leukocyte karyotype were investigated, looking at five tissue types from all three germ layers: buccal mucosa and hair from ectoderm, urinary epithelium from endoderm and ectoderm, and lymphocytes and skin fibroblasts from mesoderm. We were unable to confirm mosaicism in these patients, although in 2 out of 10 there was the suggestion of a small percentage of euploid cells in skin and blood karyotypes.


Polymorphism of apolipoprotein E. III. Effect of a single polymorphic gene locus on plasma lipid levels in man. The two autosomal codominant alleles of the Apo E-N/D polymorphism, Apo En and Apo Ed, have a considerable influence on plasma lipid levels and distribution in man. Serum cholesterol levels are highest in phenotype Apo E-N, intermediate in phenotype Apo E-ND, and low in phenotype Apo E-D. Contrary VLDL-cholesterol is highest in phenotype Apo E-D, intermediate in heterozygotes, and lowest in phenotype Apo E-N. Serum-triglyceride, VLDL-triglyceride and the ratio of VLDL-cholesterol/serum-triglyceride are also intermediate in phenotype Apo E-ND between the two opposite homozygous groups. 10% of heterozygous Apo E-ND subjects exhibited a beta-VLDL subfraction compared to 0.8% in phenotype Apo E-N and 100% in Apo E-D. Hence the three phenotypic groups exhibit metabolic differences in vivo, and the gene Apo Ed has a mild dyslipoproteinemic effect even in a single dose. The Apo E-N/D polymorphism may therefore be a major influence on the occurrence of arteriosclerotic vascular disease in man.


Risk of malignancy and chromosomal polymorphism: a possible mechanism of association. A significantly increased incidence of heterochromatic chromosomal variants, particularly of A1 and C9, has been found in a group of 120 patients with malignant or premalignant diseases. People presenting with such a kind of polymorphism usually have an increased chromosomal breakage rate. Genetically increased susceptibility to breaking agents may be the unifying concept explaining the increased incidence of heterochromatic variants found in couples with sterility or abortions, in karyotypically normal malformed or retarded children, and in patients suffering from different malignant or premalignant diseases. Chromosomal imbalance is probably the basis for initiation of malignancy whose development is influenced by many different factors.


Familial middle lobe bronchiectasis.

Familial middle lobe bronchiectasis. A rare familial occurrence of middle lobe bronchiectasis is reported in two siblings of a family with seven children. No definite cause for the development of bronchiectasis could be established. Enlarged hilar lymph nodes were found in the resected middle lobe which were compressing the middle lobe bronchus, and this may have contributed to the development of bronchiectasis.


A true hermaphrodite dispermic chimera with 46,XX and 46,XY karyotypes. A 16-year-old male with hypospadias and gynaecomastia had a rudimentary uterus with a right Fallopian tube and ovary; the left gonad was a functioning testis. Cytogenetic studies showed cells with 46,XX and 46,XY sex chromosomes in cultured blood, skin and gonadal tissues. Cells with the 46,XX constitution predominated in all tissues. Extensive investigations failed to demonstrate blood cell and serum chimerism, but there was little genetic variation of these characters between family members. Cytogenetic studies demonstrated that the father had contributed different marker chromosomes to the 46,XY and 46,XX cell lines of the propositus, whereas the mother had contributed the same two informative markers to both cell lines. The patient was a chimera with two diploid cell lines of different sex that had developed from the products of two separate acts of syngamy. Dispermy was demonstrated, and, whereas there was no evidence of different maternal contributions to the chimeric cell lines, uncertainty remains that these were identical.


Reye syndrome associated with vaccination with live virus vaccines. An exploration of possible etiologic relationships. To determine whether vaccination with live virus vaccines may be etiologically related to Reye syndrome, we examined 404 cases reported to the Center for Disease Control. Fifteen of 269 children with Reye syndrome has been inoculated with live virus vaccines within 30 days before onset of illness. Although this temporal relationship may have occurred by chance, seasonal distribution and clustering of incubation periods suggests that live virus vaccines may occasionally serve as cofactors in the etiology of Reye syndrome through undefined mechanisms.


Office screening for asymptomatic urinary tract infections. The evaluation of a practical, economic and reliable method screening the urines of asymptomatic girls in a busy pediatric office. The urines of 3,270 asymptomatic girls were screened at annual physical examinations. The urines were collected in Dixie Cups without prior preparation of the perineum and cultured on 5% sheep cell agar. Less than 2 per cent of the specimens showed significant growth, thus requiring no follow-up visits by 98 per cent of the patients. Slightly less that 1/2 of one per cent were found to have asymptomatic urinary tract infections. The procedure was found to be practical, economically feasible and reliable, and was well accepted by both the parents and patients.


The unrealized potential of the medication monitor. The medication monitor is a dispenser with a time recording system for determining when patients remove medication. It has demonstrated that nurses and physicians can estimate patient compliance with considerable accuracy. It could be used: (1) to assure that only patients actually ingesting medication are used to evaluate new drugs, (2) to study the factors that influence compliance and strategies to improve compliance, (3) to prevent escalation to more toxic drugs or expensive diagnostic procedures when failure to respond is due to poor compliance, (4) to supervise compliance when society has an overriding interest in therapeutic success, and (5) to monitor the effects of air pollution. Specially designed medication monitors could be used to provide the proper amount of compensatory medication when a patient forgets and to reduce the chance that a suicidal patient will impulsively take an overdose.


Bromocriptine inhibits norepinephrine release. Bromocriptine is a dopamine agonist that induces postural hypotension and can be used as an antihypertensive. The drug inhibits release of norepinephrine (NE) from an isolated artery by stimulating presynaptic receptors. In normotensive subjects it lowers both plasma and cerebrospinal fluid (CSF) levels of NE by 50% and lowers blood pressure moderately in standing subjects and slightly in recumbent subjects. Through central and peripheral mechanisms, bromocriptine inhibits sympathetic nervous discharge of NE.


Furosemide-induced adverse reactions in cirrhosis of the liver. Furosemide is frequently used for ascites and causes adverse reactions (AR). In an intensive prospective drug monitoring study of 1,920 patients, 172 (8.9%) had cirrhosis of the liver and received furosemide. Mean age was 53 years, and 66.3% were male; and 87% had alcoholic cirrhosis. Eighty-eight (51.2%) had 221 events that by consensus of the monitoring team and attending physicians were either definitely of probably related to furosemide. No AR was fatal but 24% of patients had severe reactions. Almost all reactions were dose-related (96%). The most common were electrolyte disturbances (23.3% of patients) and volume depletion (14%). Furosemide-induced coma occurred in 20 (11.6%) patients and was more frequent in patients with prior hepatic encephalopathy (p less than 0.0005). Higher total doses (p less than 0.001), hyerbilirubinemia (p less than 0.05), prolonged prothrombin time (p less than 0.02), and longer hospital stay (p less than 0.001) were associated with higher frequencies of AR to furosemide. The frequency of hypokalemia did not decrease when potassium chloride or potassium-sparing diuretics were added to furosemide therapy. Frequdncy of AR did not correlate with age, sex, renal impairment, serum albumin, transaminase, or alkaline phosphatase.


Effect of food on kinetics of 8-methoxsalen. Kinetics of 8-methoxsalen were studied in 5 healthy subjects under fasting and nonfasting conditions. The plasma concentration-time data could be fitted to a zero order absorption one-compartment model. The area under the curve (AUC) values were higher (p less than 0.05) under nonfasting compared to fasting conditions, indicating higher relative bioavailability of the drug in the presence of food. No significant differences were observed in the lag-time for the start of the absorption, the apparent zero-order absorption rate constant, or the elimination rate constant. It is suggested that the drug should be taken in a standardized way in relation to food during the ultraviolet (UV) light treatment.


Noninvasive kinetic approach to the estimation of total hepatic blood flow and shunting in chronic liver disease--a hypothesis. The intact hepatocyte theory of chronic liver disease suggests a relationship between the degree of shunting of total liver blood flow around the functional liver cell mass and the fraction of functional liver cell mass. By defining this relationship we have developed pharmacokinetic equations to permit the estimation of both total hepatic blood flow and the extent to which this blood flow is shunted. The method requires the determination of the systemic (hepatic) clearances of a high (e.g., indocyanine green [ICG]) and a low (e.g., antipyrine [AP]) extraction ratio drug in the same patient. Applying these equations to literature data obtained from patients with moderate or severe chronic liver disease and from patients with a surgical portacaval shunt, we find: (1) a modest decrease in total hepatic blood flow (16%) and a significant degree of shunting (27%) in patients with moderate chronic liver disease; (2) a substantially reduced total hepatic blood (52%) and extensive shunting (72%) in patients with severe chronic liver disease, and (3) a degree of shunting comparable to that estimated in patients with moderate chronic liver disease but a seriously compromised total hepatic blood flow (a reduction of 55% compared to normal) in patients with surgical portacaval shunts.


Mechanisms of nonlinear disposition kinetics of sulfamethazine. Five healthy male subjects received oral doses of 10 and 40 mg/kg of sulfamethazine (SMZ) approximately 14 days apart in a nonrandomized crossover study. Blood and urine samples were collected for at least 24 and 72 hr, respectively. All samples were assayed by the Bratton-Marshall procedure for SMZ and apparent N-acetylsulfamethazine (NSMZ). Recovery of total drug (SMZ + NSMZ) in urine was 88.9% following the low and 79.5% following the high dose. The low and high dose plasma concentration time curves were not readily superimposable (i.e., nonlinear kinetic behavior was observed). The data suggest that several mechanisms contribute to the nonlinearity. Specifically, a dose-dependent decrease in absorption rate displaced the plasma concentration-time curve to the right in some subjects, whereas apparent metabolic clearance (Clm) decreased with increasing dose (estimated assuming dose = amount of SMZ + NSMZ in urine to 72 hr) in all subjects (0.35 ml/min/kg for the low and 0.23 for the high dose). Still greater dose-dependent effects were found when apparent Clm of unbound drug was determined, since free fraction rose from 0.11 to 0.30 over the observed plasma concentration range. Renal clearance (ClR) of Smz appeared to be a complex function of time. In the low dose study it ranged from an average of 0.071 ml/min/kg at 2 hr to 0.146 ml/min/kg at 6 hr after drug. After the high dose comparable values were 0.083 and 0.128. Interindividual variability and pronounced nonlinear kinetics of SMZ after 40 mg/kg suggest that this dose is probably a poor choice for the determination of acetylator phenotype.


Acetaminophen kinetics in acutely poisoned patients. A kinetic model of acetaminophen elimination over a wide dose range has been developed on the basis of (1) kinetic data from normal adults who received a usual dose (up to 2 gm) of the drug and (2) the composition of urinary metabolites of acetaminophen excreted within 24 hr by 29 patients who had ingested up to 26 gm of acetaminophen in suicide attempts (including 2 that were fatal and 5 with evidence of severe intoxication). The model consists of the following parallel pathways: conjugation with glucuronide by Michaelis-Menten kinetics, conjugation with sulfate by Michaelis-Menten kinetics, renal excretion of acetaminophen by apparent first-order kinetics, and formation of an oxidative metabolite (which is responsible for the hepatotoxicity of acetaminophen) by apparent first-order kinetics. There is good agreement between the model-predicted and actual urinary excretion of individual acetaminophen metabolites for doses of 0.8 to 26 gm and between model-predicted and actual plasma acetaminophen concentrations in both the low (normal subjects) and high (intoxicated subjects) concentration ranges. Computer simulations indicate that unsaturation of acetaminophen sulfate formation, previously shown to be feasible in vivo, should decrease the formation of the hepatotoxic metabolite. This prediction is consistent with experimental data obtained in preliminary studies on mice.


Inhibition of hepatic drug metabolism by norethindrone. In order to assess the effect of norethindrone on hepatic drug metabolism in man, hepatic N-demethylation of aminopyrine was studied by means of the aminopyrine breath test (ABT) in 7 healthy women during two menstrual cycles. Aminopyrine metabolic clearance rates were also studied in 3 women. The women were examined at the ends of the first, second, and third weeks before starting progestogen therapy and at the same times during a second menstrual cycle during which they took norethindrone, 350 microgram/day. The ABT was 5.1 +/- 1.9% (mean +/- SD) during the three control weeks and lower (p less than 0.001) during the three weeks on norethindrone, 3.9 +/- 0.9%. Aminopyrine metabolic clearance rate also fell during norethindrone therapy. The data suggest that progestogens inhibit hepatic microsomal function.


Assessment of antibiotic efficacy in acute bacterial meningitis. Currently, antibiotic efficacy in acute bacterial meningitis is evaluated in several stages. First, animals are used to assess antibiotic penetration into cerebrospinal fluid (CSF) in the absence and presence of an inflammatory stimulus. Second, concentrations of drug are correlated to in vitro killing studies. Third, clinical evaluations compare the new drugs to currently available antimicrobic--but drug failures nevertheless occur, e.g. the experiences with cephalosporins and aminoglycosides. We propose that brain tissue levels of antibiotics are an additional parameter to be monitored. Drugs that penetrate the brain substance should yield higher ventricular concentrations than drugs that penetrate the choroid plexus alone. A protective benefit may also be afforded to brain tissue per se. Experience with chloramphenicol, which penetrates the blood-brain barrier, supports these concepts; so also, do the failures with cephalosporins and aminoglycosides which, despite high CSF concentrations of these agents, afford evidence that currently monitored parameters are inadequate predictors of therapeutic efficacy.


Blood collection techniques, heparin and quinidine protein binding. With the use of glass syringes without heparin and all glass equipment, the percent of unbound quinidine was measured by ultrafiltration and a double-extraction assay method after addition of 2 microgram/ml of quinidine sulfate. Compared to the all-glass method, collection of blood using Vacutainers resulted in an erroneous and variable decrease in quinidine binding related to blood to rubber-stopper contact. With glass, the unbound quinidine fraction was (mean +/- standard error) 10 +/- 1% in 10 normal volunteers, 8.5 +/- 1.5% in 10 patients with congestive heart failure, and 11 +/- 2% in 11 patients with chronic renal failure (although in 8 of the latter 11 patients the percent of unbound quinidine was 4 or more standard errors from the mean of the normal group). During cardiac catheterization, patients had markedly elevated unbound quinidine fractions: 24 +/- 2% (p less than 0.001). This abnormality coincided with the addition of heparin in vivo and was less apparent after the addition of up to 10 U/ml of heparin in vitro (120% and 29% increase in unbound quinidine fractions, respectively). Quinidine binding should be measured with all glass or equivalent equipment.


Post-traumatic respiratory distress syndrome. During the past two decades there has been recognition of the role of acute respiratory failure in the deaths of patients with shock from any cause. Leaky capillaries are the common pathophysiologic event. The pulmonary capillary bed is affected by the toxic action of vasoactive substances, gastric aspirates, and fat embolism; by the obstructive action of platelet, fibrin, and leukocyte clots; and by changes in the balance between perfusion pressures and oncotic pressures. This is complicated by increases in pulmonary vascular pressures from associated heart disease or overenthusiastic replacement of blood volume. The early treatment of the shock state, early intubation and ventilation, and the use of agents designed to improve capillary integrity have led to a significant reduction in mortality from this common problem.


Thoracic and vascular injuries.

Thoracic and vascular injuries. Thoracic and vascular injuries may cause rapid demise of the traumatized patient. A sound knowledge of resuscitative techniques, diagnostic maneuvers, and surgical anatomy allows the attending physician to salvage many of these patients, even those near death upon arrival in the emergency center.


Emergency management of poisoning and overdose. The management of the poisoned patient can be difficult and challenging. The task often demands the physician's entire resources in putting together pieces of history and significant physical findings to make a diagnosis. He must then carefully support and stabilize the patient under constant monitoring, while making efforts to prevent further absorption of the toxin, enhance excretion, and treat complications as they arise.


Analysis of biological rhythms using an interactive structured autoregressive modelling technique. A method of spectral-type analysis for rhythmic biomedical data is presented based on autoregressive modelling techniques. The emphasis has been on portability between data-processing machines, so that the programmes are written in FORTRAN 4 for the ICL 1900 series computers. The programmes are structured in blocks allowing for simple alteration to an interactive mode allowing the calculation and display of pre-filtering stages, model coefficients, the pole-zero plot, residuals, AR frequency spectrum, FFT of raw and filtered data. The method works on a small number of cycles and gives a direct read out of significant spectral components.


An iterative algorithm for the separation of action potential sequences. Various iterative algorithms for separation of superimposed event sequences were designed, and their efficiency examined through simulation studies. It has been found that a double parallel-serial algorithm improved markedly the efficiency of the filtration process. For the same probability of detection of the event series to be extracted, the probability of 'impurity' events dropped by roughly 0.10, as compared to the non-iterative fixed window width algorithm. Conclusions are drawn regarding separation of motor unit action potential sequences from the total electromyogram.


MIC-II - a program for the determination of cardiac output, arterio-venous shunt and regional blood flow using the radioactive microsphere method. MIC-II is a versatile BASIC computer program designed to calculate the cardiac output, the arterio-venous shunt and the regional blood flow from data obtained by the radioactive microsphere method. The samples are measured in a gammaspectrometer with a multichannel pulse height analyzer and the data are recorded on tape. Up to 10 different nuclides may be used simultaneously, including tracers which are not bound to microspheres. The nuclides may have overlapping energy spectra. The analysis of the energy spectra is performed according to the matrix method. Standard samples, each containing one pure nuclide, are measured to obtained the overlap matrix. The unkown amounts of the nuclides in the samples are obtained by solving a system of simultaneous linear equations. Up to 100 organ samples may be taken in one experiment. Up to 10 different organ maps, containing a text label for each organ specimen, may be created, edited, modified and stored on tape for convenient identification of input and output. Numerous validity checks for imput and output make MIC-II easy to use, even for non-computer trained personel.