Enzyme-coupled measurement of ethanol in whole blood and plasma with a centrifugal analyzer.

We describe an automated enzymic method for ethanol determination with a centrifugal analyzer (the GEMSAEC) by measuring the rate of the reaction catalyzed by alcohol dehydrogenase and coupled to aldehyde dehydrogenase. The detection limits, reproducibility, and accuracy of the method have been evaluated. It can be applied to whole blood or plasma, with or without previous deproteinization. Our results, compared with those by an automated alcohol dehydrogenase method in the presence of semicarbazide, show an improved linearity, sensitivity, and rapidity of determination.


Atomic absorption spectrophotometry of free circulating platinum species in plasma derived from cis-dichlorodiammineplatinum(II).

We describe a method of analysis for free circulating platinum species derived from cis-dichlorodiammineplatinum(II) in blood plasma. Protein-bound and free platinum species were separated from each other by centrifugal ultrafiltration. Platinum in the ultrafiltrate was converted to a cationic complex by reaction with ethylenediamine, and the product was collected on paper impregnated with cation-exchange resin, where it could be stored indefinitely without loss. The platinum was eluted from the disk with 5 mol/liter hydrochloric acid, and an aliquot of this solution was then analyzed by flameless atomic absorption spectrophotometry. The overall analytical recovery of platinum was 80 +/- 2%. The minimum quantity of cis-dichlorodiammineplatinum detectable was 35 microgram/liter of plasma at the 99% confidence level. Detector response was linearly related to drug concentration in the range from 80 microgram to 290 mg of Pt per liter of plasma. Reaction variables were made optimal, so as to yield maximum sensitivity and reproducibility (+/- 2%) consistent with minimal sample transfers and manipulations.


Biochemical changes in a porcine model of acute pancreatitis.

Pancreatitis was induced in 11 miniature pigs by infusing a bile salt-trypsin solution into the pancreatic duct. Seven animals served as sham-operated controls. Serum ionized calcium, total calcium, albumin, total protein, inorganic phosphorus, urea nitrogen, magnesium, insulin, glucagon, and hematocrit were determined every six to 12 h over a period of one week in both test and control animals. We observed significant decreases in ionized and total calcium, modest decreases in albumin, and significant increases in the inorganic phosphorus, urea nitrogen, and hematocrit in the pancreatitic pigs. The latter two findings were consistent with early acute hypovolemia. Glucagon and insulin appeared to play no role in the hypocalcemia. Glucagon concentrations increased to the same degree in both test and control animals, probably as a result of the stress of being handled and operated on. The highest concentrations of inorganic phosphorus and the lowest concentrations of both ionized and total calcium were seen 18 h after the induction of pancreatitis in the test animals. These findings suggest that parathyrin (parathormone) was not being secreted in adequate amounts, or that the target organs were unresponsive to parathyrin.


Maleimide as an inhibitor in measurement of erythrocyte glucose-6-phosphate dehydrogenase activity.

Erythrocyte glucose-6-phosphate dehydrogenase activity is measured with a centrifugal analyzer by use of a commercial reagent kit and of the reaction glucose-6-phosphate + NADP+ leads to 6-phosphogluconolactone + NADPH. Rate of production of NADPH is measured and related to hemoglobin concentration. Maleimide is added to inhibit further production of NADPH in a secondary reaction by endogenous 6-phosphogluconate dehydrogenase. The method is compared with others that are designed to circumvent the secondary reaction by either (a) addition of excess phosphogluconate dehydrogenase to drive the secondary reaction to completion or (b) inhibition of endogenous phosphogluconate dehydrogenase by 2,3-diphosphoglycerate. The present method has the advantages that reaction rate more quickly becomes linear and reagent cost is less as compared with other methods. The within-run coefficient of variation was 3%. The various methods investigated showed good statistical correlation.


Analysis for carbamazepine in serum by electron-capture gas chromatography.

We describe an analytical method for determining carbamazepine in serum by electron-capture gas chromatography. A single-step extraction is followed by formation of the N-pentafluorobenzamide derivative with pentafluorobenzoyl chloride. For quantitation either of two internal standards may be used: 10-methoxy carbamazepine or 7-chloro-5,11-dihydrodibenz[b,e] [1,4]-oxazepine-5-carboxamide (Squibb Compound No. 10996). The procedure requires 0.5 ml of serum. Analytical recoveries are 96%. Coefficients of variation routinely are less than 2% for concentrations of carbamazepine that are within the therapeutic range.


An interlaboratory study of measurement of aspartate aminotransferase activity with use of purified enzyme materials.

The Center for Disease Control (CDC), the New York State Department of Health (NYSDH), the College of American Pathologists, and 23 manufacturers of diagnostic products participated in an interlaboratory study of aspartate aminotransferase (EC 2.6.1.1) methodologies. Six different lyophilized materials were prepared and characterized and then distributed to 293 laboratories for aspartate aminotransferase measurements. The specimens included one human serum; four catalytic concentrations of the cytoplasmic isoenzyme, two purified from human erythrocytes, and two from porcine heart; and one matrix bovine serum albumin (30 g/liter) blank. The purified isoenzymes were prepared in the matrix. We present data on Michaelis parameters (Km and Vmax), Arrhenius plots, activation with pyridoxal 5-phosphate, vial-to-vial variability, and stability on reconstitution. The 281 responses showed that most of the laboratories used NADH-detection methods (91.1%), monitored at 340 nm (79.4%), and reported results in U/liter (89.4%). The percentage of laboratories reporting use of reaction temperatures of 30 and 37 degrees C was evenly divided, i.e., 42.7 and 42%, respectively. Analytical values reported by participating laboratories were categorized by reporting temperature, instrument, and method. Results were most consistent for a selected group of laboratories that supplemented optimized reaction solutions with pyridoxal 5-phosphate.


Some problems in development of a high-performance liquid chromatographic assay to measure 25-hydroxyvitamin D2 and 25-hydroxyvitamin D3 simultaneously in human serum.

A high-performance liquid chromatographic technique was examined that may allow simultaneous measurement of 25-hydroxyvitamin D2 and 25-hydroxyvitamin D3 in a single sample of human serum. Concentrations of 4 microgram/liter or greater are accurately measured. However, the prepurification procedure allows partial separation of the two metabolites, and so tritiated 25-hydroxyvitamin D3 can be used as an internal standard for accurately monitoring the analytical recovery of 25-hydroxyvitamin D3, but not that of 25-hydroxyvitamin D2. The ability of most prepurification procedures to partly separate the 25-hydroxy metabolites of vitamin D2 and D3 mandates the need for individual internal standards to accurately monitor the recovery of each compound. Values obtained for 25-hydroxyvitamin D2 or composite 25-hydroxyvitamin D when only tritiated 25-hydroxyvitamin D3 is used as a means of monitoring recovery are probably in error.


Increased renin concentration in plasma and amniotic fluid during storage.

Renin concentration was determined in plasma and amniotic fluid samples immediately after collection, after storage at -18 degrees C for up to 48 h, and after storage at 5 degrees C for as long as 48 h. Renin concentration increased, both in plasma (p less than 0.05) and amniotic fluid (P less than 0.02), after the storage at 5 degrees C, but no significant alteration occurred on storage at -18 degrees C. Partial activation of inactive renin could explain the observed increase in renin concentration at 5 degrees C.


Hemoglobin electrophoresis at alkaline pH on agarose gels.

We describe a modified thin agarose-gel system for use in primary hemoglobin screening by electrophoresis. The system makes use of a Tris-EDTA-borate-buffered agarose gel (pH 8.8) and a sodium barbital electrophoresis buffer (pH 8.6). Separation is effected in 20 min at a constant potential of 250 V. Eight samples can be simultaneously separated and the patterns made visible in 47 min. There are fewer operative steps needed in running and staining. Normal and the more common abnormal hemoglobins are separated into easily visualized and differentiated bands, with the separation of HbA and F significantly improved over that attainable by present methods.


Factors affecting measurement of total alkaline phosphatase activity in human serum, especially wavelength accuracy.

Serum alkaline phosphatase estimations by the Selected Method [Clin. Chem. 21, 1988 (1975)] are very sensitive to small errors in the wavelength setting of the spectrophotometer. With a setting error as small as 3 nm, results can be too low by as much as 23%. The product of the reaction, 4-nitrophenol, can be prepared in very pure form and can be used to check both the wavelength and absorbance accuracy of a spectrophotometer. The molar absorptivity for 4-nitrophenol obtained in the instrument being used should be used in calculating alkaline phosphatase activities.


Inter-batch quality differences in purified human prolactin.

During the past four years, we secured six batches of purified human prolactin for iodination by the same lactoperoxidase technique. Two of these batches gave us more satisfactory results in terms of assay sensitivity and consistency than did the others, regardless of the antiserum used. Gel filtration of 125I-labeled hormone revealed that these two batches were composed of at least 55% "small" prolactin while the other four batches contained from 20 to 68% "big" prolactin. This qualitative difference was the most important contribution to assay discrepancies.


A totally automated system for enzyme immunoassay of theophylline in serum.

We describe a procedure for enzyme immunoassay of theophylline (1,3-dimethylxanthine) in which all phases of the assay are totally automated in a Kinetic Analyzer (KA-150). This system permits assay of 75 10-mul samples per hour, with results available at 30-s intervals after initial sample preparation and preincubation. We compared results for 138 clinical samples by an ultraviolet method (x) and the present method (y). The slope of the comparison curve was 0.902, the y-intercept 0.402, and the correlation coefficient 0.984. The coefficient of variation for samples run in duplicate on the same day was 4.9%; it was 8.1% for samples run on different days. Specificity, sensitivity, simplicity, speed, and small reagent requirement all make this an attractive alternative to chromatographic procedures.


Bile acids measured in serum during fasting as a test for liver disease.

Total serum bile acids were estimated by an enzymic (3alpha-hydroxysteroid dehydrogenase) method in 173 fasting patients with different liver diseases, classified into 17 groups by morphological criteria. The results were not highly correlated with those for any of the other 24 tests included in the study, but moderate correlations were observed with bilirubin or alanine aminotransferase (positive) and with prealbumin (negative) in a few patient groups. The sensitivity of total bile acids in serum of fasting individuals as a liver-function test was rather high, comparable with that of serum enzymes. When discriminant analysis was used to identify optimal combinations of tests for the separation of different groups of liver diseases, we found that data on serum bile acids added some new information to that carried by the other 24 tests.


125I-radioimmunoassay for unconjugated estriol in serum of pregnant women.

An 125I-radioimmunoassay is described which measures unconjugated estriol in the serum of pregnant women. Estriol is extracted into ethyl acetate/hexane, an aliquot is evaporated, and the residue is redissolved in phosphate buffer. The sample is incubated with tracer and antibody at 37 degrees C for 15 min and then at 4 degrees C for 1 h and 45 min. The antibody-bound fraction is then precipitated with polyethylene glycol and isolated by centrifugation. Because the antigen-antibody complex is stable in the presence of polyethylene glycol, the separation steps are not influenced by timing. Extraction recovery of 3H-labeled estriol added to a pool of sera from pregnant women averaged 96.7% (SD = 1.3, n = 10). Estriol-supplemented (5, 10, and 20 microgram/liter) serum from men, carried through the entire procedure, showed analytical recovery ranging from 94 to 106%. Structurally analogous steroids normally present in serum of pregnant women exhibit negligible cross reactivity. Day-to-day precision (CV) is 13.3% (3.1 microgram/liter), 6.4% (7.6 microgram/liter), and 5.6% (21.4 microgram/liter) for n = 21. The current reagent cost (about 17 cents per tube), and a total procedural time, including counting, of 5.5 h make this an acceptable assay for routine use.


Rapid determination of light halogenated hydrocarbons in urine.

We describe a rapid method for determining light halogenated hydrocarbons (LHH) in urine by electron capture gas-liquid chromatography. The hydrocarbons are extracted from urine into pentane. A 2-microliter injection of the pentane extract provides a detection limit of less than 1 microgram/liter.


Use of a programmable desk-top calculator for the statistical quality control of radioimmunoassays.

We have developed an interactive statistical quality-control system for the small- to medium-sized radioimmunoassay laboratory, which can be used in a programmable desk-top calculator instead of the medium- or large-scale computer systems usually required. The design of this quality-control system is modeled after the suggestions of Rodbard and has three components. The first component evaluates the relationship between the measured response variable of the radioimmunoassay and the precision (or variance) of these measurements. This derived relationship is then used in the second component of the system as the basis for the weighting function used to calculate an interative, weighted, least squares regression of the logit-log transformation of the dose-response curve. The third component uses the quality-control parameters statistically calculated from the linearized dose-response curve to monitor whether the assay is "in-control". The calculator tabulates the means and confidence limits for the various parameters and can plot the statistical quality-control charts. The major benefit of this statistical quality-control system is that it allows the real-time computation and plotting of quality-control data with a programmable desk-top calculator.


Hexosaminidase A in amniotic fluid of Tay-Sachs fetuses.

Hexosaminidase A is present in relatively low concentrations in cell-free amniotic fluids from pregnancies with Tay-Sachs fetuses. This isoenzyme was determined by an immunological procedure, radial immunodiffusion, by which hexosaminidase A can be directly and specifically detected, even in the presence of excess amounts of hexosaminidase B. No hexosaminidase A could be detected by the same procedure in Tay-Sachs fetal tissues, implying that this isoenzyme in the amniotic fluid originates from the mother.


Analysis for glutathione in blood by high-performance liquid chromatography.

A high-performance liquid chromatographic method is presented for determination of glutathione in whole blood. Sample preparation involves hemolysis, protein precipitation, centrifugation, and filtration. The glutathione in the filtrate is then separated from other sulfhydryl-containing molecules by liquid chromatography with Zipax SCX cation-exchanger followed by detection with a mercury-based electrochemical detector. The liquid-chromatographic analysis time is approximately 5 min. Because of the chromatographic separation and the selectivity of the detector, the detection step is free from interferences from other components of blood. The method has been checked by comparison with the colorimetric assay based on reaction with 5,5'-dithiobis(2-nitrobenzoic acid). The chromatographic results are consistently slightly lower, presumably because of the greater selectivity of this method.


Optimized method for measuring aspartate aminotransferase activity with the CentrifiChem Analyzer, with automatic preincubation of serum.

We propose a routine method for the mechanized measurement of aspartate aminotransferase with the CentrifiChem Analyzer, which is based on the recommendations of both the International Federation of Clinical Chemistry and the Société Française de Biologie Clinique. A modification of the CentrifiChem pipettor permits simultaneous pipetting of two reagents, thus achieving automatic preincubation of the serum in the transfer disk. Owing to the fixed reagent volumes dispensed by the pipettor, preincubation conditions had to be modified, but the recommendations for the final reagent concentrations in the assay cuvet were observed. The totally automated method correlates very well with one involving manual pipetting to reproduce the detailed step-by-step recommendations of the International Federation of Clinical Chemistry. Intra-assay precision ranged from 3.4 to 4.9% and interassay precision from 1.7 to 7.5%. We assayed 135 sera and obtained a correlation coefficient of 0.996 (a = 1.025, b = 0.08).


Continuous-flow determination of bile acids in serum, and its clinical application.

We describe a highly sensitive and accurate automated continuous-flow method for determining bile acids in serum. The bile acids are first liberated from serum protein by dialysis at alkaline pH and then measured fluorometrically after the following enzymic reaction. Bile acids are converted to 3-oxo bile acids with 3alpha-hydroxysteroid dehydrogenase (EC 1.1.1.50) with concomitant reduction of NAD+ to NADH. The hydrogen in the generated NADH is transferred by diaphorase (EC 1.6.4.3) to resazurin to yield resorfin, the fluorophore. Only 100 microliter of serum is required and 40 determinations can be done per hour. The CV for 20 replicate determinations in serum with a mean bile acid concentration of 9.8 mumol/liter was 2.6%. The CV for day-to-day variation for another serum on 27 successive days was 3.0% (mean concentration, 10.0 mumol/liter). We applied this method to 826 sera from various diseases; 29% exceeded the upper limit of normal, 10 mumol/liter, and abnormally high values (greater than 20 mumol/liter) were almost exclusively limited to sera from hepatobiliary and enteric disorders.


Determination of 8-methoxypsoralen in plasma by scanning fluorometry after thin-layer chromatography.

A rapid and sensitive method is described for determining 8-methoxypsoralen in plasma. Plasma samples are acidified with 6 mol/liter and heated in a boiling water bath to release the plasma-bound drug nondestructively. It then is extracted into a solvent mixture consisting of benzene/ethyl acetate (9/1 by vol). The solvent phase is separated, evaporated, and an aliquot of the dissolved residue is thin-layer chromatographed, with benzene/ethyl acetete (9/1) as developing solvent. The plate is dried and the spots, made visible under ultraviolet light (320-400 nm), are scanned. The smallest amount detectable is 20 ng; the overall analytical recovery from plasma is 84%. We used the method to determine the drug in the plasma of rabbits after intravenous and oral administration of 10 mg, and in one patient after an oral dose of 30 mg.


Improved methods for isolating cortisol metabolites from neonatal urine.

Urine was collected from newborns, children, and adults who had received a tracer dose of [3H] cortisol. The free and different types of conjugated cortisol metabolites were separated by ion-exchange chromatography. A modified Amberlite XAD-2 procedure was used, which enabled quantitative extraction of the extremely polar cortisol metabolites from urine from newborns. Large differences between the ion-exchange chromatographic patterns for neonates and adults were observed. Urine from neonates was shown to contain quantitatively important amounts of an as-yet-unidentified conjugate that was absent from urine from adults. The effects of three different hydrolytic methods on the neonatal steroid conjugates were studied and it was found that the unknown conjugate in urine from the newborn could be hydrolyzed by solvolysis only.


Excretion of X-prolyl dipeptidyl-aminopeptidase in human urine as determined with a new fluorogenic substrate.

X-Prolyl dipeptidyl-aminopeptidase activity was found in human urine by a sensitive fluorescence assay in which a new fluorogenic substrate, 7-glycylproline-4-methylcoumarinamide, is used. The Km value was 2.9 X 10(-4) mol/liter, and the optimum pH was 8.7 in glycine-NaOH buffer. The enzyme activity was stable at 4 degrees C for at least five days. On Sephadex G-200 column chromatography, normal human urine showed a main peak with an approximate relative molecular mass of 400 000. The procedure is simple, rapid, and accurate. The enzyme activity in urine of normal adults was: 4.30 +/- 0.13 (SE) (range, approximately 1.84-8.96) micronmol/min per gram of creatinine, and 2.16 +/- 0.09 (SE) (range, approximately 0.38-6.98) micronmol/min per liter of urine.


A useful method for predicting creatinine clearance in children.

A practical method for predicting creatinine clearance for pediatric patients from serum creatinine concentration and patient age is presented. Creatinine excretion rate (ER) can be predicted from the patient's age, in years, by the formula: ER = (0.035 X age) + 0.236. Using the predicted excretion rate and serum creatinine concentration, creatinine clearance can be predicted. There was good correlation (r = 0.90) between predicted and observed creatinine clearances in 101 subjects with various degrees of renal impairment. This method allows renal function to be rapidly estimated.


Analysis for lead in undiluted whole blood by tantalum ribbon atomic absorption spectrophotometry.

We describe a modified tantalum ribbon atomic absorption procedure for determining lead in undiluted whole blood. An instrumentation Laboratory (I.L.) Model 151 atomic absorption spectrophotometer equipped with an I.L. Model 355 Flameless Sampler was used. The Flameless Sampler was slightly modified to include three-cycle operation instead of the normal two cycles. This modified single-beam system, equipped with background correction, allows 5-microliter specimens of whole blood to be quickly and accurately analyzed. No sample preparation other than vortex mixing is involved and method reliability has been demonstrated during an extended period of successful participation in proficiency testing studies conducted by the Center for Disease Control. This tantalum ribbon methodology has further been demonstrated to be effective both as a primary screening procedure and as a confirmatory procedure, when coupled with erythrocyte protoporphyrin determinations, in screening over 300 000 clients during a three-year period of use in the Early and Periodic Screening, Diagnosis and Treatment (EPSDT) Program in Texas.


Evaluation of the co-immobilized hexokinase/glucose-6-phosphate dehydrogenase method for glucose, as adapted to the Technicon SMAC.

We assessed the analytical performance of the co-immobilized hexokinase (EC 2.7.1.1) and glucose-6-phosphate dehydrogenase (EC 1.1.1.49) method for D-glucose analysis on the Technicon SMAC. The enzyme-containing coils were usable for one month, or 12 000 tests. Bilirubin, hemoglobin, lipemia, creatinine, uric acid, citric acid, and ascorbic acid did not interfere. Results with this method were compared to those by the National Glucose Reference Method. The upper limits of the total error estimate (a combination of random and systematic errors) were 76, 74, and 125 mg/liter at concentrations of 500, 1200, and 3000 mg/liter, respectively. The error estimates were less than allowable errors based on medical usefulness; thus the method was judged to perform acceptably with respect to the Reference Method. We also present performance data for the routine SMAC glucose oxidase (EC 1.1.3.4)/Peroxidase (EC 1.11.1.7) 3-methyl-2-benzothianolinone hydrazone-N,N-dimethylaniline method, the direct hexokinase method with the Du Pont aca, and the glucose oxidase oxygen-rate method with the Beckman Glucose Analyzer.


Improved continuous-flow (SMAC) determination of serum albumin.

The albumin values determined by the bromcresol green methods do not compare well with values by more specific methods for albumin determination. The discrepancies have been related to, among other things, acute-phase reactants and are especially pronounced in the lower albumin range. These disadvantages are also inherent in a routine continuous-flow method for albumin (SMAC). The bromcresol green method has been improved considerably by shortening the reaction time before the absorbance is measured, as is described here. The modified method yields values that better agree with those by more specific methods and an influence of acute-phase reactants is no longer observed.


A micro-scale method for liquid scintillation counting, applicable to radioimmunoassay of steroids and substances of comparable relative molecular mass.

A major expense of radioimmunoassay involving tritiated tracers is that of liquid scintillation counting. We present a micro-scale method that markedly reduces the cost of liquid scintillation counting. The radioimmunoassay is done in 10 X 50 mm tubes. The antibody-bound tracer is precipitated with a second antibody, the precipitate is resuspended in 0.1 ml of water, and 0.3 ml of dioxane is added. One milliliter of a toluene-based scintillation cocktail is added, and the tube is capped and placed in an adapter for liquid scintilation counting. When this method was applied to a double-antibody testosterone radioimmunoassay, it performed comparably to assays counted by the usual method.


A solution to the problem of bilirubin interference with the kinetic Jaffé method for serum creatinine.

We measured bilirubin interference with the kinetic Jaffé method for serum creatinine. Both pooled sera with added bilirubin and icteric patients' sera were used and results with of which gave more nearly "true" values.


Analysis for nickel in plasma and urine by electrothermal atomic absorption spectrometry, with sample preparation by protein precipitation.

We describe and evaluate a method for determining nickel in plasma and urine by atomic absorption spectrometry. Proteins are precipitated with trichloroacetic acid and sulfuric acid; ammonium pyrrolidinedithlocarbamate is used as the chelating agent for nickel, and methyl isobutyl ketone as extraction solvent. The results were compared with results obtained by the acid-digestion technique for removing proteins and other organic substances. Analyses for both plasma and urine were better by the present procedure. The mean and standard deviation for nickel in plasma from 15 healthy individuals was 2.13 +/- 0.58 microgram/liter by this method. For nickel in urine from 15 healthy men the mean and standard deviation was 4.45 +/- 1.9 microgram/liter. The coefficient of variation for plasma was 11.9%, and for urine 12.2% in 10 analyses of the same plasma and urine with the protein-precipitation procedure, as compared with 26.0 and 38.2%, respectively, by the acid-digestion technique.


Effect of temperature on plasma renin samples.

Plasma renin activity was measured in parallel in Na2EDTA-contained plasma samples after storage at -20, 4, and 24 degrees C, and in the lyophilized state. In peripheral venous plasma from 22 hypertensive patients, the activity (range, 0.08-46.7 microgram/liter per hour) remained stable during three days of storage at 4 degrees C, but decreased to a variable extent when plasma was kept at 24 degrees C: in one day by 9.2%, two days by 25.6%, and three days by 74.0%. Values were the same for samples handled at room temperature and chilled to 4 degrees C within 3 h and parallel samples immediately cooled in an icebath and kept at 4 degrees C. Freezing (-20 degrees C) and thawing of plasma was associated with a 22% mean increase in activity (range, 0-83%). Lyophilization resulted in a smaller increase of plasma renin activity (mean 12%, range 0-46%). Blood for renin analysis need not be cooled immediately, but must be cooled to 4 degrees C within 2-3 h. It then is stabe for at least three days. Freezing or lyophilization appears to be associated with some cold activation of "prorenin."


An aqueous primary standard for use with the Technicon SMA 6/60.

An aqueous primary standard containing sodium, potassium, chloride, carbon dioxide, glucose, and creatinine was prepared for use with the Technicon SMA 6/60 continuous-flow analyzer. This standard, compared with a protein-base primary standard, showed no significant difference in slope, gamma-intercept, and linearity for these methods. Precision with use of the aqueous primary standard was acceptable, comparable to that for a commercial reference serum. The standard was stable for at least 30 days.


Plasma acetate levels during hemodialysis.

Before dialysis, acetate levels in hemodialyzed patients (0.27--1.1 mmol/1) were more dispersed than in normal subjects (0.20--0.65 mmol/l) and the mean value of plasma acetate was slightly higher (0.52 mmol/l versus 0.31 mmol/l). Though dialysis conditions were almost identical, the acetate kinetics during hemodialysis were very different: in most subjects, plasma acetate concentrations reached a "plateau" (mean value 5.6 mmol/l) whereas in others a continuous rise was observed, suggesting that with patients having chronic renal failure there were important individual or occasional differences in the ability to metabolize acetate. The acetate loads per minute (or mass transfers) were calculated from the blood compartment with plasma values (plasma flow and concentrations), rather than from the dialysate and using the combined calculations (plasma and whole blood values). The results ranged between 2.4 and 4.1 mmol/min. A very important and rapid fall in arterial acetate concentrations occurs in the first 20 min after the end of the dialysis and proves the rapid turnover of the acetate in man.


Investigations on the deiodination of thyroxine (T4) to 3,3'-diiodothyronine (3,3'-T2) in rat liver homogenate.

Properties of an inactivating pathway of T4 to 3,3'-diiodothyronine (T2') in rat liver homogenate are described. The intermediate product (of this reaction sequence) is reverse T3 (rT3) which is very labile and cannot be measured at pH 7.5. The apparent KM of the reaction rT3 to T2' is 2 X 10(-8) M. The activities catalyzing the reactions T4 to T3, T4 to T2' and rT3 to T2' are found in the 100 000 X g pellet. Propylthiouracil inhibits all three activities to a similar degree; alpha-methyl-p-tyrosine has no effect. T3 seems to be only a minor source of T2' production. The molar ratio of the two T4 deiodination pathways T4 to T3/T4 to T2' under these conditions is about 1.7; however, by changing the pH this ratio could be significantly altered.


The fatty acid content and drug binding characteristics of commercial albumin preparations.

The fatty acid contents of thirteen commercial preparations of human albumin were found to be in the range 0.03 to 9 mol of fatty acid/mol albumin. Marked differences were found between the preparations in the binding of the fluorescent probes, 5-dimethylamino-naphthalene-1-sulfonamide (DNSA) and dansylsarcosine. The displacement of these probes by ibuprofen and phenylbutazone also showed marked differences between preparations. The differences between the commercial albumin samples correlated well with their fatty acid contents and were abolished by treatment with charcoal. They were similar to the changes observed when oleic acid was added to fatty acid free albumin. The source and fatty acid content of commercial albumin preparations should be considered when comparing studies of the binding of drugs to human albumin.


Lipids and proteins of erythrocyte membrane in Duchenne muscular dystrophy.

The lipid and protein composition of erythrocyte membranes from patients with Duchenne muscular dystrophy was studied. When compared with age and sex-matched controls, no significant change was observed in the content of cholesterol and phospholipid, phospholipid components and their fatty acid composition, though the lipid content and fatty acid distributions were different between adult and child controls. The protein distribution on SDS-acrylamide gel electrophoresis was identical for Duchenne patients and controls.


Evaluation of volatile sulfur compounds in the expired alveolar gas in patients with liver cirrhosis.

Trace amounts of volatile sulfur compounds were determined in the expired alveolar gas by gas chromatography. Among these sulfur containing substances, methyl mercaptan and dimethyl sulfide were quantitatively analyzed in 116 subjects; 53 normal, 13 acute hepatitis, 11 chronic hepatitis, 20 hepatic cirrhosis, and 19 stomach ulcer and/or biopsy of gastric mucosa. Fasting level of dimethyl sulfide in cirrhotics was 4.05 +/- 1.06 ng/dl, significantly elevated by comparison with normal controls (1.54 +/- 0.09 ng/dl) (P less than 0.05). In contrast, methyl mercaptan did not show a statistically significant rise in this study. The implications of the significant increase in dimethyl sulfide concentration in liver cirrhosis are discussed.


A modified electroimmunoassay technique for uromucoid in urine.

An electroimmunoassay technique for the estimation of urine uromucoid has been studied in an effort to improve its performance. It was found that strict attention to specimen collection, preservation and storage was important. The conditions used for the production of immunologically active uromucoid subunits utilising sodium dodecyl sulphate were found to be critical, needing rigid standardisation if acceptable precision is to be achieved.


Isolation and identification of a new potent inhibitor of creatine kinase from human serum.

Human serum contains a very potent inhibitor of creatine kinase in addition to urate which was characterized as an inhibitor of this enzyme by Warren (Warren, W.A. (1975) Clin. Biochem. 8, 247). This new inhibitor was isolated from human serum by dialysis, negative DEAE-cellulose adsorption and a series of gel filtration chromatographies. The inhibitor so isolated was an organic compound. Kinetic investigation showed noncompetitive inhibition versus creatine, as well as MgATP. Infrared spectroscopy revealed amino and carboxyl groups. The isolated material was ninhydrin-positive. Thin-layer chromatography of the dansyl derivative showed several fluorescent spots. Quantitative amino acid analysis revealed the presence of several amino acids. Of these only cystine and cysteine were inhibitory in the standard inhibitor assay, using rabbit MM creatine kinase. Testing with human MM creatine kinase only cystine was found inhibitory. Cystine has a specific inhibitor activity of 600 anti-Units per mg, using rabbit or human MM creatine kinase, respectively. Urate by comparison has a specific inhibitor activity of 45 anti-Units per mg using human MM creatine kinase.


Serum IgG and IgD and levels in some infectious and noninfectious diseases.

Serum IgG and IgD levels were determined in the following groups: professional blood donors, healthy smokers and patients with acute hepatitis, with acute salmonellosis, with hepatic cirrhosis, with cancer (prostate, lung and gastrointestinal tract) and with benign diseases of the same organs as the cancer patients. IgG was significantly increased in the groups of patients with hepatitis, hepatic cirrhosis and cancer. IgD values showed a wide dispersion in all the groups, which do not allow for comparisons among means. For that reason, linear regression analysis between IgG and IgD was done, the results being significant only in the two groups with infectious diseases (acute hepatitis and acute salmonellosis), which suggest that IgD could be involved in the immune response against their respective pathogenic agents.


Human erythrocyte thiopurine methyltransferase: radiochemical microassay and biochemical properties.

A radiochemical micromethod for the determination of thiopurine methyltransferase (TPMT) activity in human red blood cells (RBC) is described. Both 6-mercaptopurine and 6-thioguanine were substrates for the TPMT activity in the human RBC. Apparent Michaelis-Menten (KM) values for 6-mercaptopurine and 6-thioguanine were 3.2 X 10(-4) M and 2.0 X 10(-4) M, respectively. The apparent KM value for S-adenosyl-L-methionine, a co-substrate for the reaction, was 1.7 X 10(-6) M. The pH optimum for the reaction was approximately 7.5. Blood samples from 73 randomly selected adult subjects had a mean activity of 10.2 +/- 2.4 (mean +/- S.D.) units/ml packed red blood cells. The range of activities was from 4.6 to 14.2 units/ml. The results of experiments in which partially purified human kidney TPMT was added to RBC lysates and of experiments in which "low" and "high" activity lysates were mixed gave no indication that individual variations in RBC TPMT activity were due to endogenous inhibitors or activators of the enzyme.


Initial activity and inactivation of alkaline phosphatase in different lots of buffer.

Alkaline phosphatase activities were determined in six lots of 2-amino-2-methyl-1-propanol (AMP) and in six lots of diethanolamine (DEA) buffers without preincubation of the sample. There appeared to be differences between the lot numbers in both cases, resulting in a variation in initial activity. When serum samples are preincubated with buffer a loss of activity was observed in 4 out of the 6 AMP buffers. Four human isoenzymes showed varying inactivation during preincubation with AMP buffer. No loss of activity was observed when the preincubation was done with the six DEA buffers. These results indicate that the purity of the commercially-available buffers is quite unsatisfactory.


3-Methylcrotonylglycine excretion in 3-hydroxy-3-methylglutaric aciduria.

1. 3-Methylcrotonylglycine was identified in urine from an infant with 3-hydroxy-3-methylglutaric aciduria. 2. The concentration of 3-methylcrotonylglycine in urine was approximately one sixth of that of the other metabolite of 3-methylcrotonyl-CoA, 3-hydroxyisovaleric acid. 3. The presence of both metabolites in the infant's urine indicates an inhibition of 3-methylcrotonyl-CoA carboxylase activity in tissues of the infant.


[1-14C]Ethanol breath test in alcoholic liver disease.

The activity of ethanol metabolising enzymes was assessed in 51 patients with alcoholic and non-alcoholic liver disease using tracer doses of [1-14C]ethanol and measuring 14CO2 excretion in the breath. Alcoholic patients with only fatty infiltration of the liver showed significantly increased activity compared with controls. Comparing alcoholic patients with cirrhosis and a serum albumin greater than 28 g/l, activity in those with a recent history of continued heavy drinking was significantly greater than in patients who had abstained from alcohol. In addition, both groups of alcoholic cirrhosis showed significantly more activity than patients with non-alcoholic cirrhosis. The activities of patients with acute alcoholic or viral hepatitis were normal when their prothrombin times were less than 7 sec prolonged, but were reduced when prolongation exceeded 7 sec. These results demonstrate that in chronic alcoholic liver disease, even with cirrhosis, alcohol can still increase the activity of ethanol oxidising enzymes provided hepatic function remains adequate. However, this response is lost in acute liver damage and in chronic alcoholic disease with severe hepatic dysfunction.


Dosage of hemoglobin A1c by isoelectrofocusing.

A new Hb A1c routine dosage method is proposed, using thin-layer isoelectrofocusing. The mean level in normal adults is 4.66% (sigma = 1.05). In diabetic (treated) patients, the distribution of Hb A1c levels is a non-Gaussian one, with extreme values of 3 to 13% and a maximum frequency peak at 5.5%.


Regan variant alkaline phosphatase in gastrointestinal carcinoma.

A fast-moving alkaline phosphatase band on polyacrylamide gel electrophoresis has been found in 6 patients with carcinoma of the liver and gastrointestinal tract. This isoenzyme resembled the placental isoenzyme in its inhibition by L-phenylalanine, its resistance to L-homoarginine inhibition and its molecular weight. However, it differed from the placental and Regan isoenzymes in its sensitivity to L-leucine and ethylenediaminetetra-acetic acid, its lower retardation by neuraminidase, its electrophoretic mobility and its decreased heat stability. The latter two properties also distinguished it from the Nagao isoenzyme. It was identified as the Regan Variant. The Regan Variant has hitherto been reported largely in hepatocellular carcinoma. In the presented paper we report its appearance in the sera of patients who have neoplasms in a variety of primary sites in the gastrointestinal tract. It is emphasized that, while the presence of the Regan Variant in serum may be taken as evidence of carcinoma, no conclusions can be drawn as to the site of the disease.


The influence of vitamin B-6 on cystathioninuria in premature infants.

The amount of cystathionine excreted in the urine of premature infants, ages 10 to 17 days, decreases after oral administration of 40 mg vitamin B-6 daily. Thus, it can be speculated that in vivo cystathionase of premature infants may be induced or activated by pyridoxine.


Standardization of a simple method for the estimation of haemoglobin A2.

An improved method for the estimation of haemoglobin A2, at the same time precise, simple and cheap, is proposed. Haemoglobin A is separated from haemoglobin A2 by electrophoresis on Cellogel in discontinuous buffer at alkaline pH. The strips of cellulose acetate containing the haemoglobin fractions are completely dissolved in 80% acetic acid. The percentage of haemoglobin A2 present in each sample is calculated from the values for the spectrophotometric absorbance at 396 nm. The average percentage of haemoglobin A2 (+/- standard deviation) determined by this method was 2.31 +/- 0.37 in 51 normal subjects, and 4.64 +/- 0.53 in 29 subjects with heterozygous beta-thalassaemia.


Comparison of angiotensin I and angiotensin II antibody trapping methods for determination of plasma renin concentration and activity.

Comparative determinations were made of the renin activity of human blood plasma by applying a radioimmunoassay of angiotensin I and angiotensin II, and also by parallel determinations of PRA I and PRA II. To protect the angiotensin generated in plasma, the antibody trapping method was used. The concentration of renin was also determined. It was found that, under the experimental conditions applied, when determining PRA II the renin was gradually inactivated in plasma; when determining PRA I it was protected by EDTA added to plasma. Thus PRA II is present to a lesser degree than PRA I. The experiemnts performed have confirmed the advantages of determining PRA I by the antibody trapping method.


Determination of serum ionised calcium by ion-exchange electrode in normal subjects.

Serum ionised calcium concentration [Ca2+] was measured with a calcium selective electrode in 65 normal people. A mean value of 1.06 mmol/l (+/- 0.04 S.D.) with an actual range of 0.97 to 1.13 mmol/l was obtained. Serum samples refrigerated at 4 degrees C for 24 h were satisfactory for analysis. Storage of whole blood samples for 6 h at room temperature before separation caused a very small error (+0.04 mmol/l). Mean results and ranges were similar in males and females and there was no significant correlation with age. No significant change in serum [Ca2+] was found following a normal meal. Serum [Ca2+] and total serum calcium showed a very slight correlation (r = 0.35). The method is reproducible and sensitive.


A simple colorimetric method for ascorbic acid determination in blood plasma.

The paper describes a simple method for determination of ascorbic acid using acid phosphotungstate. The reagent has been found to be specific and sensitive to ascorbic acid and can be used for ascorbic acid determination in plasma with good reproducibility.


Hypersialyloligosacchariduria in mucolipidoses: a method for diagnosis.

A method is described for the detection of abnormal oligosaccharides in a small (5 ml) volume of urine, employing filtration on a Bio Gel P-6 column, determination of neutral sugar and bound sialic acid, and determination of creatinine content. With this method increased urinary excretion of sialic acid-rich oligosaccharides has been detected in nine patients with mucolipidoses (five cases of mucolipidosis II and four patients of mucolipidosis, with beta-galactosidase deficiency). The filtration patterns of oligosaccharides in mucolipidoses were clearly distinguishable from those in other inborn errors of metabolism. Total excreted oligosaccharides were increased 5--30-fold in these patients; mucolipidosis II, 640--1350 microgram neutral sugar/mg creatinine; control 54 +/- 20 microgram neutral sugar/mg creatinine. The oligosaccharides consisted of three sialic acid-rich fractions and were common in both types of mucolipidosis. Our data indicate that hypersialyoligosacchariduria is the main biochemical feature of both types of mucolipidosis.


A simplified radioimmunoassay for melatonin and its application to biological fluids. Preliminary observations on the half-life of plasma melatonin in man.

A simplified and rapid radioimmunoassay (RIA) for melatonin is presented. Melatonin is extracted from seru, plasma or urine and RIA is performed by using [3H]melatonin as the tracer. The standard curve covers the range 0.2--4.3 nmol/l. By increasing the sample volume the range can be extended to 0.06 nmol/l. The intra-assay variability is 7% (relative standard deviation = rsd) and the inter-assay variability is 10% (rsd). The recovery of melatonin added to calf serum is 96%. The long term variability of the assay (43 assays on aliquots of one serum sample during 6 months) is 13.5% (rsd). The serum levels in man after one oral dose of 430 mumol melatonin have been measured. The peak value, 620 nmol/l, was noted after 0.5 h and the melatonin concentration was still above the normal range at 24 h (2.1 nmol/l).


Methodical investigation of the production of antibodies towards 3,4-dimethoxyphenylethylamine.

In this study the synthesis of various antigens from 3,4-dimethoxyphenylethylamine (3,4-DMPEA) is described. Antigen A was formed by coupling the acylated side chain of 3,4-DMPEA to the protein, while antigen B was synthesized by introducing an acylated amino group to the benzene ring and linking this reactive group to the protein. With antigen A an antiserum with a titer of 1 : 16000 could be raised, while with antigen B coupled to human albumin and bovine gamma-globulin the antiserum had a titer of 1 :1000 and 1 : 4000. Antibodies formed by immunization with antigen A exhibited a high specificity for substituents of the benzene ring, but were less specific for substituents of the side chain. Antibodies formed by treatment with the antigen B were specific for both kinds of substituents. So far, it has not been possible to harvest any specific antibodies towards the corresponding antigens of dopamine.


A simple and specific competitive protein binding assay for 24,25-dihydroxyvitamin D in human serum.

A sensitive and specific competitive protein binding assay for 24,25-dihydroxyvitamin D was developed using rat kidney cytosol as the binding protein. It also included a chromatographic step on a Sephadex LH 20 column to separate the metabolite specifically. The average value for 24, 25-dihydroxyvitamin D in serum in 19 male and female healthy subjects aged from 20 to 40 was found to be 8.24 +/- 0.34 ng/ml (1.98 +/- 0.08 . 10(-8) mol/l) mean +/- S.D. In hepatic insufficiencies the levels are higher (14.15 +/- 3.59 ng/ml) than in normal subjects. A comparison between 25-hydroxyvitamin D and 24,25-dihydroxyvitamin D levels was made.


Flameless atomic absorption spectrometry determination of gallium in biological materials.

The application of flameless atomic absorption spectrophotometry to the quantitation of gallium in urine, serum and tissues is described. The method can be used to detect gallium concentrations as low as 100--200 ppb in fluids and tissues. Significant interference with the gallium atomization signal was caused by CaCl2; however, the interference could be completely prevented by using the chelating agent EDTA. This method makes feasible the quantitative determination of the pharmacokinetic parameters of gallium administration as an anticancer drug in animals and humans.


A two-stage enzymatic method for determination of uric acid and hypoxanthine/xanthine.

A method is described by which plasma or serum concentrations of uric acid and hypoxanthine/xanthine may be determined in a two-step sequential method. The principle of the method is that hydrogen peroxide, liberated by the action of uricase and xanthine oxidase on their substrates, is coupled to the production of a coloured product.


The estimation of D-isocitric acid in urine using isocitrate dehydrogenase.

The amount of D-isocitric acid in urine has been estimated using the enzyme isocitrate dehydrogenase. The technique is rapid and easy to perform. Reproducibility of results was good and results from recovery experiments were excellent. The concentration range for early morning urine samples from normal adults was 0.08-0.65 mmol/l with a mean of 0.29 mmol/l.


Radioimmunoassay of free urinary 18-hydroxydeoxycorticosterone (18-OH-DOC) in patients with essential hypertension.

Specific antiserum was raised in white New Zealand rabbits using 18-hydroxydeoxycorticosterone-3-oxime-BSA complex as antigen. The urinary free 18-OH-DOC was estimated after dichloromethane extraction and separation in one paper chromatographic system (propylene glycol/toluene). The mean 18-OH-DOC excretion value (+/- S.D.) in normal subjects was 0.861 +/- 0.527 microgram/24 h (n=23). ACTH produced a 25-fold increase in the excretion of free 18-OH-DOC. Dexamethasone suppressed the values to the lower range of sensitivity. 32% of patients of essential hypertension showed a moderate increase in the free urinary 18-OH-DOC values. The mean value (+/- S.D.) in the low renin hypertension group was 2.50 +/- 1.49 microgram/24 h (n=19), in the normal renin patient group 1.84 +/- 1.22 microgram/24 h (n=38). The difference between controls and the hypertensive groups was statistically significant. Among the different hypertensive groups significant differences could not be calculated.


Sensitive assay of creatine kinase isoenzymes in human serum using M subunit inhibiting antibody and firefly luciferase.

A sensitive method for the assay of B subunit and total creatine kinase activity is described. The ATP formation in the creatine kinase reaction is continuously monitored by measuring the bioluminescence obtained with a purified firefly luciferase reagent. The B subunit activity is determined using an M subunit inhibiting antibody resulting in greater than 99.5% and approximately 50% inhibition of MM and MB isoenzymes, respectively. The bioluminescent method correlated well with a similar spectrophotometric method in the assay of B subunit as well as total creatine kinase activity (r greater than or equal to 0.98). However, the bioluminescent assay is considerably more sensitive, allowing the assay of B subunit activity in serum from healthy individuals. This is due to the inherent sensitivity of the bioluminescent assay of ATP, a reduced analytical interference from adenylate kinase and a reduced reagent blank. The within-series precision at 1 U/liter and greater than 52 U/liter corresponded to a C.V. of 14% and 3%, respectively. The method is as rapid and suitable for routine work as spectrophotometric methods. From a clinical point of view the new method is of particular interest in the early diagnosis of small acute myocardial infarctions.


Electrophoretic identification of the brain isoenzyme of creatine kinase following treatment with anti-BB antisera.

A procedure is described for accurately determining the presence of true creatine kinase isoenzyme BB by fluorescent staining following electrophoresis on either cellulose acetate or agarose. Treatment of sera with anti-BB inhibiting antibody prior to electrophoresis and subsequent enzymatic staining allows clear identification of creatine kinase BB in presence of interfering artifacts. The utilization of an immunological means of identifying BB following electrophoresis avoids the pitfall of associating an artifactual BB isoenzyme with a disease state. Using this technique, presence of creatine kinase BB in patients with carcinoma, cardiac disease and renal failure has been verified.


[Biochemical study of the glycosaminoglycan peptides obtained from osteoarthrotic and normal femoral heads (author's transl)].

Glycosaminoglycan peptides prepared by papain hydrolysis of different regions were obtained from osteoarthrotic and normal human femoral heads. Data obtained in these experiments show that in osteoarthrosis a decrease in keratan sulfate and an increase in chondroitin sulfate are observed. Since keratan sulfate appeared to play an important role in proteoglycan aggregation, we suggest that the keratan sulfate decrease is one of the factors involved in the cartilage disorder observed in patients suffering from osteoarthrosis.


Radioaffinity assay, a new approach to binding assays applied to the measurement of serum albumin.

The affinity adsorbent Cibacron Blue F3GA-Sepharose 4-B has been used to develop a binding assay for human serum albumin. The method is simple, accurate and precise. It agrees well with the 'rocket' immunoelectrophoretic method and is proposed as an alternative technique for the re-estimation of albumin levels in the low range (less than 30 g/l) where the bromocresol green dye-binding method overestimates. Bilirubin, several drugs, gammaglobulin, haemoglobin and heparin do not interfere with the estimations.


Gas-liquid chromatographic determination of ibuprofen in human plasma.

A gas-liquid chromatographic method for the estimation of Ibuprofen in human plasma is described. The procedure is rapid with the free drug being analysed thus eliminating the need for any derivatisation steps. The method allows the drug concentrations to be analysed down to a level of 2 mg/l using 2 ml plasma.


Cystic fibrosis: cell culture classes in a Danish population.

The cystic fibrosis (CF) culture phenotype of dermal fibroblasts (metachromasia, metabolic cooperation) of a group of 131 Danish CF patients and their families were studied to determine the distribution of the two CF culture classes and their prognostic significance. Of these, 62.6% (82) were Class I, 31.3% (41) Class II and 61.1% (8) were proposed to be genetic compounds. The occurrence of Class II was twice that found in a group of patients from New York (13%) and Minnesota (18%). The prognosis for Class II CF patients was considered to be poorer as: (1) The initial diagnosis was made earlier in Class II than in Class I or the compounds (63% of Class II were diagnosed in the first year of life, as compared to 35% in Class I and 13% of the compounds). (2) Only 5% of the Class II patients survived over the age of 15 years, both being deceased at the end of the study in 1976, whereas 24% of Class I and 63% of the compounds were over 15 years at the end of the study. This research added further evidence for genetic heterogeneity within the clinical syndrome, cystic fibrosis.


Familial aplasia or hypoplasia of the patella.

A father with bilateral absence of the patella and his son with pronounced hypoplasia of the patellae are described. A possible relationship between this syndrome and hereditary osteo-onycho-dysplasia is discussed.


Caudal regression anomalad (sacral agenesis) in siblings.

Hypoplasia of the caudal end of the spine and associated anomalies were observed in two male siblings who also had congenital heart disease. The disorder has overlapping features with the VATER association and the caudal regression anomalad, and probably has a genetic basis, although the mode of inheritance is not clear.


Dermatoglyphic and radiographic findings in a mother and daughter with pseudohypoparathyroidism.

The dermatoglyphic features of a mother and daughter with pseudohypoparathyroidism were compared with those of 19 other reported PHP cases and with findings typical of 45,X Turner syndrome. Our observations included large patterns with a predominance of whorls, unusual accidental patterns on the third fingers, elevated total and absolute finger ridge counts, extralimital digital triradii, intermediately placed axial triradii, and a single complete transverse palmar crease. With barium-coated hand radiographs, the positions of the palmar digital triradii were compared with those of the underlying metacarpal and carpal bones. Normally, the fourth digital triradii (c) are superficial to the epiphyseal region of the proximal phalanx, near the fourth M-P joint. In our cases, the c triradii were distal to the proximal phalanx, near the fourth M-P joint. In our cases, the c triradii were distal to the M-P joint, adjacent to the diaphysis of the proximal phalanx. These findings, related to post-natal differences in growth potential of osseous structures and overlying dermal ridge tissues in this disease, may also be relevant to other syndromes with abnormal development of the hand. The need for further delineation of PHP dermatoglyphics and comparison of findings with data from Turner syndrome and normals is stressed.


Sialidase (alpha-n-acetyl neuraminidase) deficiency: the enzyme defect in an adult with macular cherry-red spots and myoclonus without dementia.

A 31-year-old male is described who has macular cherry-red spots, increased deep tendon reflexes and and myoclonus without dementia. An older brother died at age 33 of a disease with similar symptomatology. Homogenates of cultured fibroblasts from the patient exhibited 2.6, 8.1 and 12.4% of normal mean sialidase (neuraminidase, N-acetyl-neuraminosyl glycohydrolase, EC 3.21.18) activity, respectively, against 2-(3'-methoxyphenyl)-N-acetyl-alpha-neuraminic acid, N-acetyl-neuramin-lactose and fetuin. Activities of 14 other lysosomal enzymes were within the range of normal control fibroblasts. The sialidase activities in fibroblasts from the patient's parents and children were 30 to 67% of normal. It is concluded that this is the first proven case of a new autosomal recessive disorder resulting in cherry-red spots, myoclonus and a sialidase deficiency.


Histocompatibility typing and the counseling of families with ankylosing spondylitis.

White individuals who are HLA B27-positive have an increased risk of developing ankylosing spondylitis or related diseases. HLA typing can be used in counseling relatives of persons with spondylitis, if the limitations of presently available data are recognized.


Central nervous system abnormalities--contrasting patterns in early and late pregnancy.

A total of 509 specimens of spontaneous abortion were studied. Of 364 complete specimens, 15 (4.1%) had central nervous system (CNS) abnormalities. The defects which were seen were anencephaly, spina bifida, iniencephaly, encephalocele and anencephaly combined with complete rachischisis. A high proportion (five out of 15) had the more unusual defects of iniencephaly and encephalocele. All except one had ceased development at less than 12 weeks of gestation. Sex chromatin studies showed that males outnumbered females amount CNS defective fetuses. When the month of conception was calculated for these abnormal pregnancies, summer and winter peaks were detected. Only one of the 15 patients had a family history of neural tube defect (NTD). Histological examination of all small fetuses aborted spontaneously revealed two additional facts. First, in fetuses with a localised external CNS defect, the internal abnormality was more extensive. Second, the CNS was also abnormal in some fetuses with no visible external defect. The proportion of abnormality is much higher than at birth and is also higher than in other surveys of spontaneous abortion. We suggest that screening for serum alphafetoprotein should be undertaken and amniocentesis considered in pregnancies subsequent to an abortion of this type.


Turner syndrome with rare karyotypes.

Five cases of Turner syndrome with rare karyotypes are presented. The spectrum of chromosomal findings ranges from a female karyotype with a deletion of the short arm of one X chromosome, to a normal male karyotype. The following karyotypes were found: one case with 46,XXp--; two cases with 45,X/46,X,r(X); one case with 45,X/47,XYY; and one case with 46,XY.


Purification and characterization of altered cystic fibrosis liver alpha-L-fucosidase.

alpha-L-Fucosidase (E.C.3.2.4.51) from two cystic fibrosis livers has been purified and characterized. Purification was accomplished by an affinity chromatographic procedure previously used for normal liver alpha-L-fucosidase. Characterization of the two cystic fibrosis alpha-L-fucosidases indicated that they were very similar to normal liver alpha-L-fucosidase with regard to pH optima profiles, Michaelis constants (Km's), subunit structure and antigenicity. However, gas liquid chromatographic analysis revealed altered carbohydrate compositions for both the cystic fibrosis alpha-L-fucosidases. The three major sugars found in normal purified liver alpha-L-fucosidase (mannose, N-acetylglucosamine and sialic acid) were reduced in the cystic fibrosis alpha-L-fucosidases, on average, to 51%, 44% and 32%, respectively, of their normal amounts.


Branchio-oto-renal dysplasia and branchio-oto dysplasia: two distinct autosomal dominant disorders.

Three families are presented, one with branchio-oto-renal dysplasia (BOR) and two with branchio-oto dysplasia (BO). The former syndrome is characterized by external ear malformations, cervical fistulae, mixed hearing loss and renal anomalies of varying severity. The latter syndrome differs in that there are no renal anomalies and that the sensorineural component of the hearing loss may be absent. The external ear malformations are quite variable in both syndromes. Evidence is presented which supports the idea that these two syndromes are not phenotypic variants of the same autosomal dominant mutation but distinct disease entities. The BOR syndrome appears to belong to a larger group of hereditary ear dysplasia-renal adysplasia syndromes that must be carefully ruled out in all patients with familial branchial arch malformations as well as in the parents and siblings of infants with "Potter facies" in the presence of auricular malformation and renal adysplasia.


Congenital hydrocephalus and cerebellar agenesis.

In a sibship of three brothers, two expired shortly after birth with congenital hydrocephalus, and necropsy of one revealed cerebellar agenesis and absence of the foramina of Luschka and Magendie. The non-specificity of the Dandy-Walker anomaly is discussed, and it is suggested that the present patients demonstrate another form of heritable hydrocephalus, possibly on an X-linked recessive basis.


Changes in lymphocyte accumulation and proliferation in the lymph nodes draining the pregnant uterus.

Changes in weight, lymphocyte accumulation and cellular proliferation have been measured in the lymph nodes draining the uterus during inter- and intra-strain pregnancies and compared with similar effects after other antigenic stimuli. From the data obtained it was concluded that "paternal" antigenic stimulation from the conceptus initiated an immune response in these nodes. The mechanisms of the subsequent suppression of this response are discussed.


The complement profile in relation to the "reactor" state: a study in the immediate post-partum period.

C56 (activated "reactor") could be generated by adding zymosan to only nineteen out of the fifty serum samples obtained from southern Chinese women 3 to 5 days after a normal spontaneous delivery. As a group, post-partum sera showed a 25% increase in total haemolytic complement, an almost two-fold increase in haemolytic C5, C4 and C8 plus C9 activity, a 50% increase in antigenic C3 and haemolytic C2, C1 and factor B activity, a less than 20% increase in haemolytic C6 and C7 activity, and a 20% decrease in factor D and C1 inhibitor activity. Consequently, their C5:C7 ratios were significantly elevated. This finding supports, in part, the theory that the "reactor" state or ability to generate C56 depends on a relative excess of C56 over C7. However, comparison of the complement profile between sera with and those without "reactor" activity did not reveal any difference, except a greater elevation of C5 in the latter. It appears possible that a grossly excessive level of C5 may, in fact, be unfavourable to the generation of C56.


Hepatocyte damage induced by lymphocytes from patients with chronic liver diseases, as detected by LDH release.

We have used a cytoplasmic enzyme system in the study of the in vitro cytotoxic activity of human peripheral blood leucocytes against isolated liver cells in patients with chronic liver diseases. Lymphocytes from primary biliary cirrhosis and chronic active liver disease patients were shown to have an in vitro capacity to induce a cytolitic effect on isolated hepatocytes, as demonstrated by the enhanced release of lactate dehydrogenase (LDH), a cytoplasmic marker enzyme. No significant LDH release was seen with control lymphocytes of normal persons or with lymphocytes from patients with alcoholic cirrhosis. Our results corroborate, in a different assay system, by a simple, reproducible and different method, that lymphocyte-mediated liver cell damage "in vitro" occurs in both primary biliary cirrhosis and chronic active liver disease.


Lymphocytotoxic antibodies in systemic lupus erythematosus: evidence for reactivity with i antigen.

Sera from ten patients with systemic lupus erythematosus (SLE) were tested for lymphocytotoxic antibodies (LCA) before and after absorption with cord and adult erythrocytes at 4 degrees C. Seven of the sera showed a significant reduction in cytotoxicity after absorption with the cord erythrocytes, but minimal or no reduction following absorption with the adult red blood cells. Of the remaining three sera, the cytotoxicity was equally reduced by cord and adult red cells in one and was unaffected by absorption in two. Eluates were prepared from the two sera using cord and adult red blood cells. The cytotoxicity of the cord cell eluates was significantly greater than those of the adult red cell eluates. These data indicate that the LCA in most SLE sera have specificity for the i antigen, which is present on lymphocytes and cord erythrocytes.


Production of the complement cleavage product, C3a, by activated macrophages and its tumorolytic effects.

Mouse peritoneal macrophages were activated in serum-free culture with lipopolysaccharide, dextran sulphate or C3b. They were found to liberate into the culture medium a cytolytic factor and a factor which was pharmacologically indistinguishable from C3a. The cytolytic activity was neutralized by antiserum against C3a. These results suggest that macrophages can be activated by C3b (or agents that generate C3b) to cleave C3, which they themselves produce. In this way the activated macrophages form C3a, which appears to be a major factor in macrophage-mediated cytolysis. These findings have implications in tumour immunity and in the pathogenesis of inflammatory reactions.


Membranoproliferative glomerulonephritis (MPGN type I) and dense deposit disease (DDD) in children.

A review of the histologic findings in 27 patients originally classified as having some form of membranoproliferative glomerulonephritis (MPGN) revealed 13 with MPGN Type I and 14 with dense deposit disease (DDD). In all 14 cases where electron microscopy was performed, the histologic diagnosis was confirmed. In nine cases the diagnosis of DDD was easily made in histologic sections on the basis of ribbon-like, brightly PAS positive thickening of the GBM, without "splitting" and with relatively slight mesangial proliferation. However, in five cases the picture closely resembled MPGN Type I, with hypercellularity, "splitting" and only focal ribbon-like thickening of the GBM, which required oil immersion for recognition. There was no correlation between the serum C3 levels and the morphologic diagnosis: nine (4 MPGN Type I, 5DDD) had persistently low C3 levels, two (1 MPGN Tye I, 1DDD) were normocomplementemic, and in 16, the C3 levels varied. C3 levels increased with time in nearly all patients. The clinical course was similar in patients with MPGN Type I and DDD. Significant correlations between the rate of development of renal failure and sex, age of onset, nephrotic syndrome or therapy could not be made. The five year survival rate was 87%; 12 developed renal insufficiency by five years. Although morphologically distinct, these findings suggest that DDD is clinically indistinguishable from MPGN Type I.


Studies on cell water and electrolytes in chronic renal failure.

Studies were carried out in 10 normal subjects and in 16 patients with moderately severe chronic renal failure (CRF) to determine the quantities of potassium (K), sodium (Na) and water in muscle tissue obtained by needle biopsy and in white cells (WBC) from peripheral venous blood. Depletion of intracellular K with high levels of Na and normal water were found in patients with CRF. Therefore, the cellular electrolyte pattern was not substantially different from that reported by others in patients with advanced uremia although there was no increase in intracellular water (as can occur in end-stage CRF). These data suggest that in end-stage CRF accumulation of intracellular water could be relatively independent of intracellular electrolyte balance.


The effects of arteriovenous shunts on cardiac function in renal dialysis patients--an echocardiographic evaluation.

To estimate the flow rate in arteriovenous dialysis fistulae and its effect on cardiac function we investigated 7 dialysis patients (1 woman, 6 men, mean age 33 +/- 3 years) echocardiographically before and after 10 minutes occlusion of the arteriovenous shunt. Cardiac index was signigicantly raised (4.31 +/- 0.23 l/min/m2) and fell significantly into the normal range to 3.89 +/- 0.11 l/min/m2 after occlusion of the AV fistula. This reduction was mainly due to a fall in heart rate from 82 +/- 4 beats/min to 76 +/- 5 beats/min. The estimated AV fistula flow rate (0.71 +/- 0.17 l/m) has been similarly reported in invasive hemodynamic studies. Parameters of cardiac contractility were in the lower range of normal with an average of 1.16 +/- 0.10 circ/sec for the mean velocity of fiber shortening (Vcf) and 65 +/- 4% for the ejection fraction. These decreased minimally after fistula occlusion. The single echocardiographic measurements of Vcf and ejection fraction showed good correlation (r=0.97) and revealed evidence that only these patients with poor left ventricular function and septal hypertrophy showed improved cardiac performance after occlusion of the arteriovenous fistula. Thus echocardiography may offer the opportunity to select those patients who need small AV-fistulae for optimal renal and cardiac treatment.


Neonatal anaemia secondary to blood loss.

The newborn has a limited capacity to tolerate acute haemorrhage. Prompt diagnosis and therapy are essential for survival. Blood loss can occur in the newborn due to occult haemorrhage, prior to birth or during delivery, obstetric accidents, maternal haemorrhage, or secondary to recurrent blood sampling. Special precautions must be taken when events known to cause fetal haemorrhage have occurred during pregnancy. These include a maternal history of transfusion reaction in the absence of a transfusion, third trimester bleeding with placenta praevia, placenta abruptio and vasa praevia, emergency caesarean sections, twin pregnancies and amniocentesis. The clinical manifestations of post-haemorrhagic anaemia at birth depend on the extent and duration of blood loss. When acute massive blood loss has occurred, the infant is extremely pale and requires immediate transfusions or volume expanders. Although the haemoglobin may be normal initially, it rapidly falls within six to eight hours after birth. Other causes of extreme pallor in the newborn include asphyxia and anaemia secondary to haemolysis. Infants who have developed acute post-haemorrhagic anaemia are hypovolaemic, are neither jaundiced nor cyanotic, and respond to therapy with volume expanders. The clinical picture with chronic blood loss is usually mild and responds to conservative therapy with iron alone. Internal haemorrhage should be suspected when a 24 to 72 hour newborn rapidly deteriorates and has evidence for hypovolaemic shock without signs of external blood loss. The blood withdrawn for laboratory evaluation in the high risk newborn must be carefully monitored so that it can be replaced before the newborn becomes compromised.


Methaemoglobinaemia in the newborn infant.

Methaemoglobinaemia is a rare condition in which the haemoglobin iron is in the oxidized or ferric state and cannot reversibly bind oxygen. If severe, this condition leads to hypoxaemia and death. Methaemoglobinaemia may be acquired by exposure to oxidant drugs or chemicals. Alternatively, it may be inherited due either to a haemoglobinopathy, which renders the haem iron more susceptible to oxidation, or to a defect in the erythrocyte's enzymatic capacity to return methaemoglobin to the reduced state. Newborn infants have an increased risk of methaemoglobinaemia due to a normal transient deficiency of methaemoglobin reductase in neonatal erythrocytes and the increased tendency of fetal haemoglobin to assume the met-configuration. The clinical approach to the neonate with methaemoglobinaemia is no different from the approach to older patients. The need for therapy is dictated by the severity of hypoxic symptoms. Since the diagnosis is made simply and the treatment is effective, a high index of clinical suspicion may be potentially life-saving.


Social work and the stroke patient.

Social work treatment is a significant part of the stroke rehabilitation program. The social worker helps the patient, his family, and the rehabilitation team to work together to reach realistic goals, individually determined. The knowledge and skills of the social worker are directed toward helping the patient and family in the adjustment process and to facilitate the stroke patient's return to the community at the highest possible level of emotional, social and economic functioning.


Orthopedic prognosis of brain-injured adults. Part I.

In a retrospective study of 121 patients who have sustained closed head injury, the levels of functional return are reviewed in terms of factors of prognostic value. These factors are age, coma duration and presence of decerebration. Decerebration, when it resolves early, can be compatible with a good functional outcome. The majority of patients who survive head injury make substantial neurologic recovery. Almost 50% of the patients have a good neurologic recovery. About two-thirds of the patients become ambulatory and capable of self-care activities.


Orthopedic management of brain-injured adults. Part II.

Orthopedic management of the head trauma patient is divided into 3 phases--acute, recovery and stable. The treatment of bone injury is the main thrust in the acute phase. Guidelines were formulated from a retrospective review of 91 head trauma patients including spine and other fractures. The recovery phase consists of prevention and correction of joint deformities due to spasticity. Position, range of motion and splints are the basic methods employed. Indications and techniques for phenol injection to the posterior tibial and musculocutaneous nerves are reviewed. Heterotopic bone formation will be identified in this phase and treated early. In the final phase, one and one-half years postinjury, surgical treatment is employed to improve extremity function. Procedures proven of value in treatment of stroke patients are applicable. Heterotopic bone can also be definitively treated by excisional surgery supplemented by new medical agents.


A patient-administered questionnaire for arthritis assessment.

A patient-administered arthritis record system has been in use for 4 years. Thirty patients with various chronic arthritic conditions were studied to compare patient responses on the questionnaire to those obtained at the physician interview. Comparisons were also made between the "review of symptoms" and the actual physical findings documented in the medical record. The self-administered inventory of functional activities is a reliable and useful way to document specific activity achieved by a patient. Further, the questionnaires also aid in the evaluation of any therapeutic intervention and give a patient-perceived measurement of the clinical outcome in terms of quality of life. As a patient self-administered record, it allows for a major saving of physician time while acquiring accurate, complicated, but important, repetitive, time-oriented information. This system includes the American Rheumatism Association's Uniform Data Base for Rheumatic Diseases. An important set of questions has been added which improves functional assessment that is necessary to evaluate the success of surgical therapy.


Surgical release of congenital torticollis in adults.

Longstanding untreated congenital torticollis in adults is uncommon and surgical release in such a case can be hazardous or fraught with many possible complications. A two-stage, open, bipolar surgical division of the contracted sternocleidomastoid muscle in a 33-year-old woman who developed pain and paresthesiae in the neck and arm was performed under general then local anesthesia. Surgery then controlled gradual stretching in a halo-vest achieved complete subsidence of pain, a near-full range of neck motion and correction of the tilt deformity, without complication. The facial asymmetry and the underlying fixed skeletal changes remained. Surgical release and gradual correction in a halo apparatus can eliminate the need for major spinal surgery in the correction of longstanding torticollis.


Therapy evaluation and management of patients with hemiplegia.

Appropriate treatment of the hemiplegic patient depends on a thorough evaluation of sensation and motion in the affected extremities. Realistic goals for self-care, mobility, home, and community skills may be then established. The basic role of therapy when dealing with a stroke patient includes preventing and correcting deformities, improving a patient's functional ability, and increasing strength, control, and upper extremity use when appropriate. Medical intervention may be necessary to augment the occupational and physical therapy programs in the areas of relief of pain and correction of deformities.


The cervical spine in rheumatoid arthritis.

Of 53 severely rheumatoid patients, 43% had cervical spine involvement, Six major categories were found: a) C1-C2 subluxation; b) serial subluxation; c) upward translocation of the odontoid; d) odontoid erosion; 3) apophyseal joint fusion; and f) miscellaneous findings of osteoporosis, endplate erosion, and disk space narrowing without osteophytosis. Although disease duration and activity appeared to correlate somewhat with the development of cervical spine disease, this was by no means universal. Rheumatoid cervical spine disease may be dangerous even in the absence of clinical signs and symptoms. It is therefore recommended that the cervical spine be evaluated in patients with severe rheumatoid disease before general anesthesia is scheduled irrespective of cervical spine complaints recorded in the chart.


Radiographic evaluation of scoliosis: a reassessment and introduction of the scoliosis Chariot.

Serial evaluation of scoliosis relies on measurement of curvature on radiographs. Progression or improvement is based solely on the assumption that the radiograph gives a true picture of the configuration of the spine in the AP projection, and that patient position remains constant with serial radiographs. Slight rotation of the patient allows the kyphosis or lordosis normally present in the spine to either increase or decrease the measured scoliosis curve, depending on the direction of rotation. Reliance on technician positioning of the patient introduces a random error of such a magnitude as to make serial evaluations invalid. The use of the Scoliosis Chariot as a positioning device guarantees reproducibility of patient position, thus eliminating the problem of random error.


The psychosocial sequelae of the Milwaukee brace in adolescent girls.

The psychosocial sequelae of treatment by Milwaukee brace were investigated in 38 girls. These girls were found to cope well after an initial critical period. Only minor disturbances of body image and sexual attitudes were observed. It seems that except for individual severe cases, no specific psychiatric intervention is needed in those patients, and a competent orthopedic surgeon could manage all the psychological aspects.


Management and outcome of pyogenic vertebral osteomyelitis.

A rational program of diagnosis and therapy can be recommended on the basis of the results in a series of 34 cases of pyogenic vertebral osteomyelitis. The diagnosis can be made on history, physical examination, sedimentation rate, bone scan and X-ray. Blood and urine cultures should be done and may be of value. Biopsy of the area confirms the diagnosis and establishes adequate and specific antibiotic therapy. Bed rest is needed to relieve the patient's initial discomfort and to prevent deformity. Immobilization is most important in those patients with greater than 50% vertebral destruction for the first 3 months in order to prevent deformity.


Posterior shoulder dislocation with ipsilateral humeral shaft fracture. A case report.

A 41-year-old man incurred the unusual combination of subacromial posterior dislocation of the shoulder and ipsilateral humeral shaft fracture. The importance of inspection of joints proximal to long bone fractures cannot be overemphasized. The transscapular view is easily adapted to the diagnosis of this injury. When recognized early, closed reduction is the preferred treatment; open reduction, as in the present case, is reserved for chronic dislocation.


Air gap magnification techniques in upper extremity fractures.

Air gap magnification is useful in the diagnosis of upper extremity fractures specifically as it applies to nondisplaced fractures of the radial head, carpals and metacarpals. These injuries often prove difficult if not impossible to detect on routine roentgenographs. Gap magnification is technically simple to perform, requires no special equipment, and has been useful in evaluating subtle roentgenographic changes.


Congenital radio-humeral synostosis. A case report.

In a 7-month-old male infant with congenital radiohumeral synostosis and associated absent first metacarpal, floating thumb, and hypoplasia of the humerus, the synostosis was resected. Elbow motion was obtained and one year postoperatively there was no recurrence of the synostosis.


Two-stage flexor tendon reconstruction in the hand.

The results of two-stage flexor tendon reconstruction in the hand, evaluated in 25 fingers in 20 patients with an average followup of 5 months, were graded on the basis of total range of active flexion and combined extension loss. Two-stage flexor tendon reconstruction can significantly improve the functional status of fingers with extensive damage or scarring of the flexor mechanism. Function was generally improved despite the preoperative status of the digit, but a completely normal flexion range can be restored only in rare instances. Poor results were noted in 8 patients. The likelihood of success may be predictably less in patients with a prolonged interval between injury and reconstruction, joint contractures, synovitis following stage-one, multiple grafts, and advanced age.


Subtrochanteric fractures of the femur treated with nail-plate devices: a retrospective study.

Fifty-four cases of nonpathologic subtrochanteric fractures of the femur were treated by fixation with nail-plate devices. Of the 48 final cases, 42 patients (88%) united successfully after a single operative procedure. Six patients (12.5%) developed a non-union and required further surgery, an experience similar to that of other authors. Ten per cent appears to be the expected non-union rate with nail-plate devices. At this time the Jewett nail and the compression screw should be regarded as part of the the orthopedist's armamentarium in the treatment of comminuted subtrochanteric fractures of the femur.


Superficial radial neuritis and De Quervain's disease. Report of three cases.

Three patients with De Quervain's disease developed superficial radial neuritis, a complication which seems not to have been considered in the literature. All 3 patients were women. One responded to conservative therapy and the other 2 required tenolysis of the abductor pollicis longus and extensor pollicis brevis tendon sheaths to relieve symptoms.


Congenital anterior subluxation of the distal ulna. A case report.

A healthy 17-year-old girl with painful congenital subluxation of the distal ulna was successfully treated by surgical stabilization of the distal radioulnar joint. This procedure may avoid or delay the need for resection of the distal end of the ulna.


Posterior tibial tendon transfer anteriorly through the interosseous membrane: a modification of the technique.

A modification of the transfer of the posterior tibial tendon anteriorly through the interosseous membrane for the correction of equinovarus deformity of the foot was carried out without complication on 44 extremities of 22 children age between 8 and 15.


Complete posterior dislocation of the talus. Case report and discussion.

Complete dislocation of the talus is an injury that is produced by a great magnitude of force, producing severe soft tissue injury, frequently vascular compromise, often with subsequent avascular necrosis. Complete posterior dislocation of the talus seems not to have been reported previously. The treatment in a 39-year-old man was designed on the basis of experience with antero-medial dislocation. Treatment ranges from attempted anatomical reduction to early arthrodesis of one or all of the articulations of the talus, with and without talectomy. No one method has shown to be superior to the others. Oen reduction is often unsuccessful, probably because of ankle malalignment. Avascular necrosis of the talus without collapse is not necessarily painful. In the present case talectomy and tibio-calcaneal fusion was performed one year after injury. The symptomatic results were good. Accurate anatomical reduction should be the aim of initial therapy. Definitive therapy can be designed to fit the requirements of the individual case.


Below-knee amputation using the sagittal technique: a comparison with the coronal amputation.

Fourteen patients had below-knee amputation performed by the coronal technique and 17 by the sagittal technique. By changing the incision to a sagittal plane, a substantial improvement is observed in wound morbidity and in earlier time of definitive prosthetic wear.


Radical one-stage posteromedial release for the resistant clubfoot.

A large proportion of congenital talipes equinovarus is resistant to correction by nonoperative means. The authors reviewed 54 feet which required surgical intervention, and the operative management utilized was a radical one-stage posteromedial release. Application of plastic surgical techniques has obviated problems of skin healing. Comparable to results reported by others, a good-to-excellent functional and cosmetic result can be expected in 90% of the cases. Careful attention to a well-designed postoperative regimen will frequently obviate the need for additional surgery.


Bilateral simultaneous rupture of the quadriceps tendons.

Bilateral simultaneous rupture of the quadriceps tendons is very rare and occurred in an 82-year-old man. This may be the fifth case to have been reported in the English literature. Only minor stress on extensor mechanisms preceded the ruptures. Interrupted mattress sutures restored muscle continuity and function. A "pull-out" wire system was not used for protection of healing muscles because adequate amount of tissue mass was available for approximation. Excellent results require intensive postoperative physical therapy. Old age of the patient should not be a deterrent to surgical treatment in carefully selected individuals.


Recurrent osteoblastoma: a review.

A review of 3 new osteoblastomas and 181 previously reported osteoblastomas revealed 18 recurrences (9.8% recurrence rate). Recurrence was more common in the spine and pelvis. Recurrences were reported as late as 9 years after excision of osteoblastomas and long-term follow-up is indicated in this lesion. Five recurrences were reported to undergo apparent sarcomatous change. Complete en bloc resection is the preferred treatment of osteoblastomas. No recurrence has ever been reported after complete resection, however, apparent incomplete excision has given cures in many cases. Radiotherapy does not appear to prevent recurrence. Its immediate postoperative use is not recommended and may possibly be associated with apparent late sarcomatous change in some cases. Since the efficacy of radiotherapy in the treatment of established recurrence still remains obscure, further surgical intervention is indicated.


Evaluation of the Kidner procedure in treatment of symptomatic accessory tarsal scaphoid.

The Kidner operation is a successful method of treatment for symptomatic feet with Type II and Type III accessory tarsal scaphoids that do not respond to conservative methods of treatment. The success of this operation is related more to the elimination of the bony prominence on the medial aspect of the foot and its mechanical irritation than to the correction of the pronated foot by means of posterior tibial tendon transfer. The age of occurrence of symptoms can be correlated with the level of physical activity and ossification or growth of this accessory bone. Symptoms in older patients develop after injury. The pronated foot or mechanically insufficient foot increases the stress on the bony prominence of the accessory tarsal scaphoid bone and precipitates in symptoms.


Sarcoid tumor in skeletal muscle. A case report.

The 3 patterns of sarcoid involvement of skeletal muscle are microscopic infiltration, progressive myopathy and tumor formation. This is a case report and review of investigations of a 25-year-old man with the unusual tumorous form.


Polyurethane foam in postoperative casts.

One-half inch thick polyurethane foam is recommended for use in postoperative casts to avoid complications seen with postoperative swelling. The polyurethane is placed over the operative area, over the dorsum of the foot, and the anterior surface of the leg. The use of polyurethane foam in the postoperative cast not only avoids the necessity of having to split the cast in many instances but the foam also constitutes a compression dressing. If splitting of the postoperative cast should become necessary, the foam protects the skin.


Low cost surgical drill.

A low cost cordless electric drill originally designed for the home workshop has been adapted for use in the operating room and extensively employed for over a year. Permitting one-hand operation, unencumbered by power cords or air hoses, and positively free from shock hazard, this type of drill will perform the majority of drilling tasks needed by the orthopedic surgeon. The cost compares with many currently used "disposable" operating room items.


Collapsed vertebrae: a review of 659 autopsies.

One hundred and thirty-three cases showing collapse of one or more vertebral bodies were found in a review of 659 autopsy specimens of the thoracolumbar spine. There are 4 types of vertebral body collapse; 2 of the 4 have clinical significance.


Aorto-enteric fistula presenting as multicentric osteomyelitis.

A 60-year-old man treated with a prothesis for aorto-enteric fistulae developed multicentric osteomyelitis. Enteric flora were cultured from blood and bone but the diagnosis was delayed. Aorto-enteric fistulae can occur in a variety of circumstances but have become more common with the advent of reconstructive vascular surgery using prostheses. This entity frequently does not present in a dramatic way, but can be the cause of fatal bacteremia and septicemia.


The acute effects of periosteal stripping and medullary reaming on regional bone blood flow.

The immediate effects of surgical dissection on regional bone blood flow were studied using the hydrogen washout technique and the results were compared in mature and immature rabbits. Epiphyseal circulation in young animals was eliminated by stripping the epiphyseal periosteum, and even in mature rabbits epiphyseal blood flow was markedly reduced by periosteal stripping. This suggests that after skeletal maturity blood supply crossing from the metaphysis into the epiphysis is limited. The blood flow rate was not altered by wide reaming of the epiphyseal center in either young or old animals. The rates of bone blood flow in the metaphysis and diaphysis were not altered by separate periosteal stripping or medullary reaming in either age group. Combined reaming and stripping eliminated blood flow in the diaphyseal cortical bone, but in the metaphysis fairly rapid blood flow remained even after reaming and periosteal stripping were done. These findings suggest that arterial supply and venous drainage traverse both endosteal and periosteal surfaces, and either system is capable of sustaining adequate bone tissue circulation.


Effect of repetitive impulsive loading on the knee joints of rabbits.

To simulate the forces from hopping, the right foot of adult rabbits was subjected to 1 1/2 the animal's body weight 40 times a minute for 20-40 minutes per day. During these brief periods of repetitive impulsive loading the legs were held in short-leg splints to eliminate the natural shock-absorbing mechanism associated with ankle dorsiflexion and calve muscle stretching. Under these conditions subchondral bone stiffening occurred and was associated with the earliest metabolic changes of cartilage damage. When bone stiffening returned to normal the effect on the cartilage did not completely disappear, although these effects diminished. The results suggested that subchondral bone stiffening accompanies the earliest metabolic changes in osteoarthrosic chondrocytes and suggests that trabecular microfracture may occur very early in this sequence of events.


Microstructural organization of human and bovine cruciate ligaments.

Human and bovine anterior cruciate ligaments studied with the SEM demonstrate fascicular bundle and connective tissue sheath components. In the human, collagen fibers of the connective tissue sheath, although approximately the same diameter as the fascicular fibers, have an orientation suggestive of a binding rather than a tensile function. While both elements have tensile properties, it is hypothesized that the contribution from the sheath component is minimal and, consequently, detailed studies of the tensile properties of ligaments will produce meaningful data when related to the appropriate cross-sectional areas. In direct contrast to the human counterpart, the SEM appearance of bovine cruciate ligaments is tendon-like, characterized by very dense subfasciculi surrounded by very thin connective tissue sheaths.


Upper extremity surgery in stroke patients.

Surgical procedures are performed on the nonfunctional upper extremity following stroke to correct spastic flexion contractures that cause pain or prevent adequate hygiene. In the upper extremity surgical procedures are most commonly performed to improve extension at the wrist, fingers or thumb. If the deformity is primarily due to spasticity rather than fixed myostatic contracture, anesthetic block of the median and/or ulnar nerve preoperatively enables the surgeon to determine that extension will be improved after the appropriate flexor tendons are lengthened. Careful presurgical evaluation of motor sensory function enables the surgeon to predictably select those patients who will benefit from surgery.


Pathologic femoral shaft fractures comparing fixation techniques using cement.

To determine the most stable mode of internal fixation for the pathologic femoral shaft fracture with extensive cortical destruction, 2 fixation techniques incorporating methylmethacrylate were compared. Osteotomies through standardized cortical defects were created in intact embalmed femora to simulate a standard pathologic fracture. Fixation obtained with either intramedullary Schneider rods or 28-hold ASIF plates, both using bone cement, was compared in torsion and bending. In torsion, plate-fixed femora failed at a mean load of 71.2 newton-meters compared to 26.8 newton-meters for the Schneider rod counterparts. In bending, plate-fixed bones at a mean load of 8133.9 newtons compared to 1921.4 newtons for rod-fixed femora. Fixation with double plates and methylmethacrylate was clearly more stable and allowed for immediate pain-free ambulation.


Biological reaction to carbon fiber implants: the formation and structure of a carbon-induced "neotendon".

In 43 young rabbits, the tendo Achilles and flexor digitorum longus tendon were excised and replaced by filamentous carbon fiber. Tendo-Achilles in controls was repaired by silk or nylon sutures or left without replacement. Concurrent excision of the posterior tibial nerve was performed in one group of the carbon-replacing tendo-Achilles operations. When fully functioning, carbon-induced "neotendon" rapidly developed from young fibroblastic tissue outgrowths of the loose mesenchymal tissue of the perineurium and adventitia of the blood vessels in the adjacent neurovascular bundle. Silk or nylon replacement of the excised Achilles tendon did not lead to successful production of a new substitute. Carbon fibers were unsatisfactory for replacement implants for the flexor digitorum longus tendons.