Stabilization of hypoglycosylation in a patient with congenital disorder of glycosylation type Ia

A follow-up over 7 years on a patient with congenital disorder of glycosylation type Ia showed a significant normalization of hypoglycosylated transferrin. Isoelectric focusing for serum transferrin is a widely used screening method but there could be a limit of detection and the subtle changes can be also overlooked. Re-test with a different method is desirable, especially when the clinical suspicion for congenital disorder of glycosylation is high.

Health-related quality of life during four-layer compression bandaging for venous ulcer disease: a randomised controlled trial

BACKGROUND

Venous leg ulceration is a chronic debilitating condition which negatively impacts on patients' quality of life. Despite the application of gold standard treatment a number of patients suffer from 'slow to heal' ulcers, which can require treatment for years.

AIMS

The aim of this study was to compare the effects of four-layer compression bandaging (4LB) for treating venous leg ulcers with other available treatments on health-related quality of life duringtreatment.

METHODS

In this pragmatic trial, 200 patients with venous leg ulceration were randomised either to 4LB (intervention group; n = 100) or to continue their usual system of care (control group; n = 100). Analysis was by intention to treat; quality of life measurements were taken at randomisation and after six weeks of treatment.

RESULTS

4LB provided greater quality of life benefits than the control group particularly in the area of physical activity and social functioning.

CONCLUSION

Due to the long-term nature of treatment for many of these patients, the effects on quality of life should be considered when prescribing treatment. This study has shown that 4LB significantly improves the quality of life of patients during treatment for venous leg ulceration.

Randomized clinical trial and economic analysis of four-layer compression bandaging for venous ulcers

BACKGROUND

The aim of this study was to compare the cost-effectiveness of four-layer compression bandaging for venous leg ulcers with that of other available treatments.

METHODS

In this pragmatic trial, 200 patients with a venous leg ulcer were randomized either to four-layer bandaging (intervention group; n = 100) or to continue their usual system of care (control group; n = 100). The follow-up for each patient was 12 weeks. Analysis was by intention to treat; the main outcome measures were time to healing and cost to the health board per leg healed.

RESULTS

Baseline characteristics were well matched in the two groups. The Kaplan-Meier estimate of the healing rate at 3 months was 54 per cent with four-layer bandaging and 34 per cent in the control group. Throughout the 3 months, four-layer bandaging healed leg ulcers significantly earlier (P = 0.006). There was a significant reduction in the median cost per leg healed with four-layer bandaging (euro 210 versus euro 234; P = 0.040).

CONCLUSION

Four-layer bandaging is currently the most effective method of treating venous leg ulcers in a community setting.

Leg Ulcers: A Cross-Sectional Survey of Management Practices and Treatment Costs in Ireland

Objective:

To review the management and the cost of leg ulcers.

Design:

Cross-sectional survey based on a questionnaire completed by healthcare workers caring for patients with leg ulcers in a defined population.

Setting:

The Mid-Western Health Board area in Ireland with a population of 317069.

Patients:

All patients receiving healthcare for active leg ulceration.

Results:

Leg ulcers were recorded for 389 individuals and public health nurses primarily provided care (n = 283). Patients had open ulcers for a median period of 8 months (interquartile range: 3 months — 2 years) with almost half (n = 181) reporting previous episodes of ulceration. Fifty different dressing products were used to treat leg ulcers in the region. Only 52.2% (203/389) of patients had the aetiology of their leg ulcers properly investigated and evidence-based care was generally apparent in this group. Otherwise, care appeared haphazard and at times inappropriate. The estimated annual direct cost of dressing leg ulcers was £585 660.

Conclusion:

A regional strategy for managing leg ulcers needs to be clarified and implemented if practitioners are to incorporate evidence-based care into routine work.

Online single-step analysis of blood proteins: the transferrin story

The serum iron transport protein human transferrin (hTf) is a glycoprotein (MW approximately 79.6 kDa) containing two Asn-linked sites of glycosylation. The presence of specific glycoforms of hTf has been used as an indicator of carbohydrate-deficient glycoprotein syndrome (CDGS) or an indicator of alcohol abuse. The exact nature of the glycoforms described in the literature is controversial. In this work we demonstrate that the altered hTf glycoforms have lost one or both complete glycan side chains. Furthermore, we demonstrate using a combination of online immunoaffinity-postconcentration-mass spectrometry in conjunction with a blood spot cartridge that we can determine the relative quantities of the hTf glycoforms using <5 microL blood in under 30 min. This is in contrast to previous methods that used 1 mL and took 4 days. We show that this method can be useful to analyze hTf from CDGS and alcoholic patients.

Rapid determination of transferrin isoforms by immunoaffinity liquid chromatography and electrospray mass spectrometry

BACKGROUND

Congenital disorders of glycosylation (CDG) are autosomal recessive disorders that produce increased serum carbohydrate-deficient transferrin (CDT) isoforms. Methods to resolve CDT from fully glycosylated transferrin (Trf) have been based on a neutral shift in the isoelectric focusing (IEF) pattern or on a reduction in the negative charge, allowing resolution by anion-exchange chromatography. Our purpose was to develop a method of resolution and relative quantification of Trf isoforms using online immunoaffinity liquid chromatography-mass spectrometry (LC-MS).

METHODS

Serum (25 microL) was diluted with 100 microL of water before application to an immunoaffinity column that sequestered Trf isoforms. Trf isoforms were eluted from the immunoaffinity column, concentrated on a C4 column, eluted from the C4 column, and introduced into the mass spectrometer. Analysis of the Trf isoforms was entirely automated and completed in <10 min per sample.

RESULTS

The LC-MS method demonstrated that the major abnormal Trf isoforms in CDG lack one complete oligosaccharide structure (mono-oligosaccharide) or both oligosaccharide structures (a-oligosaccharide), but not the sialic acids, as presumed on the basis of IEF methods. Calculation of relative ratios among three possible species (mono-/di-oligosaccharide and a-/di-oligosaccharide) is reproducible [mean intra- and interassay CVs were 9.3% (n = 10) and 10% (n = 5), respectively]. A reference range for patients <18 years was determined by analysis of 209 samples (for mono-/di-oligosaccharide, the median was 0.041 and the range was 0.018-0.083; for a-/di-oligosaccharide, the median was 0.007 and the range was 0.002-0.036). Comparison of data obtained with an affinity chromatography-IEF method and the LC-MS method demonstrated equivalence in the interpreted results (n = 170).

CONCLUSIONS

Advantages of the LC-MS method include improved sensitivity, minimal sample preparation, and an analysis time of <10 min. The method was automated, which allowed high throughput, with >100 samples analyzed in a single day. Moreover, the nature of the oligosaccharide defect in CDG is accurately reflected by mass resolution, and subtle oligosaccharide truncations may also be detected by this method.

Identification of a 55-bp deletion in the glucocerebrosidase gene in Gaucher disease: phenotypic presentation and implications for mutation detection assays

A 55-bp deletion in exon 9 of the glucocerebrosidase gene was identified in a 28-year-old male affected with Gaucher disease. The diagnosis was established during an evaluation for mild pancytopenia and was confirmed by bone marrow histology and biochemical studies. The patient is of German ancestry. Initial DNA testing indicated homozygosity for the N370S mutation. However, subsequent testing of the patient's parents suggested that the patient and his mother carried a null allele by our assay for N370S. Further molecular studies identified a 55-bp deletion in exon 9 of the glucocerebrosidase gene (g.6767_6822del55). This deletion has been previously reported in a patient with severe Gaucher disease (1), and is present in the glucocerebrosidase pseudogene. In the previously reported case, initial DNA testing also suggested the genotype N370S/N370S, but further mutation studies were undertaken because clinical severity was greater than expected for that genotype. In contrast, our patient has an unusually mild clinical course. Thus, clinical severity cannot be reliably used to determine when to test for the presence of the 55-bp deletion. While the 55-bp deletion is not reported to be common, its actual frequency may be underestimated since it eludes detection by many standard clinical assays for Gaucher disease. This report points out the need to consider this deletion mutation which may cause erroneous interpretation of results in existing assays for the common mutations N370S and L444P. Furthermore, the importance of recommending parental analysis for individuals who test homozygous for autosomal mutations is highlighted.

Development of a rapid, quantitative method for LDL subfractionation with use of the Quantimetrix Lipoprint LDL System

BACKGROUND

Recent evidence suggests that the presence of small, dense LDL is independently associated with increased risk of developing coronary artery disease. Current methods to subfractionate LDL are time-consuming and/or technically demanding. Therefore, we have sought the development of a less complex LDL subfractionation procedure.

METHODS

LDL subfractions were separated using the Quantimetrix Lipoprint(TM) LDL System. High-resolution 3% polyacrylamide gel tubes were scanned densitometrically (610 nm) with a Helena EDC system. A computerized method to identify and quantitatively score the resolved LDL subfractions was developed. Results from the Quantimetrix method were compared using 51 plasma samples with values obtained by nondenaturing gradient gel electrophoresis (NDGGE) and nuclear magnetic resonance (NMR) spectroscopy.

RESULTS

LDL subfractionation scores correlated significantly (P <0.05) with triglyceride, HDL-cholesterol, apolipoprotein B100, and LDL-cholesterol/apolipoprotein B100 (r = 0.591, -0.392, 0.454, and -0.411, respectively). For 51 samples, the Quantimetrix method classified 21 with small, 14 with intermediate, and 16 with large LDL. Of the 21 samples classified as small by Quantimetrix, 20 (95%) were classified as small (n = 18) or intermediate (n = 2) by NDGGE. All of the 16 specimens classified as large by Quantimetrix were either large (n = 14) or intermediate (n = 2) by NDGGE. LDL score was inversely correlated (r = -0.674; P <0.0001) with LDL particle size determined by NMR spectroscopy.

CONCLUSIONS

A quantitative method for the assessment of LDL particle size phenotype was developed using the Quantimetrix Lipoprint LDL System. The method can be performed in less than 3 h in batch mode and is suitable for routine use in clinical laboratories.

Familial splenomegaly: macrophage hypercatabolism of lipoproteins associated with apolipoprotein E mutation [apolipoprotein E (delta149 Leu)]

Splenomegaly with sea-blue histiocytes is not associated with dyslipidemia, except in severe cases of hypertriglyceridemia, Tangier disease, or lecithin cholesterol acyltransferase deficiency. We describe two kindreds in which the sea-blue histiocyte syndrome was associated with an apoE variant in the absence of severe dyslipidemia. Both patients presented with mild hypertriglyceridemia and splenomegaly. After splenectomy both patients developed severe hypertriglyceridemia. Pathological evaluation of the spleen revealed the presence of sea-blue histiocytes. A mutation of apoE was demonstrated, with a 3-bp deletion resulting in the loss of a leucine at position 149 in the receptor-binding region of the apoE molecule [apoE (delta149 Leu)]. Although both probands were unrelated, they were of French Canadian ancestry, suggesting the possibility of a founder effect. In summary, we describe two unrelated probands with primary sea-blue histiocytosis who had normal or mildly elevated serum triglyceride concentrations that markedly increased after splenectomy. In addition, we provide evidence linking the syndrome to an inherited dominant mutation in the apoE gene, a 3-bp deletion on the background of an apoE 3 allele that causes a derangement in lipid metabolism and leads to splenomegaly in the absence of severe hypertriglyceridemia.

Thiopurine methyltransferase polymorphic tandem repeat: genotype-phenotype correlation analysis

BACKGROUND

Thiopurine methyltransferase (TPMT) is a genetically polymorphic enzyme that catalyzes the S-methylation of thiopurine drugs such as 6-mercaptopurine. Recently, a variable number tandem repeat (VNTR) within the TPMT promoter has been reported to "modulate" levels of this enzyme activity.

METHODS

We set out to perform genotype-phenotype correlation analysis for the polymorphic TPMT tandem repeat in 1211 clinical laboratory samples in which red blood cell (RBC) TPMT activity had been measured and to compare those results with data for 279 control DNA samples.

RESULTS

TPMT VNTR length varied from three to nine repeats ( *V3 to *V9), but the most common alleles were *V4 and *V5, with frequencies in the control samples of 0.54 and 0.36, respectively. The clinical laboratory samples were then stratified into those with "low," "intermediate," or "high" levels of RBC TPMT activity; that is, samples presumed to be homozygous for open reading frame (ORF)-based variant alleles, heterozygous for those alleles, or homozygous for the "wild-type" ORF sequence, respectively. TPMT VNTR genotype *V4/*V5 was associated with significantly higher RBC TPMT activity than were *V4/*V4 or *V5/*V5. Lowest activity levels were associated with genotypes that included an allele with more than 5 repeat elements. However, all of these effects were quantitatively small. Finally, there was linkage disequilibrium between VNTR allele *V5 and TPMT*3A, the most common ORF-based polymorphism associated with very low TPMT activity in white persons.

CONCLUSIONS

These observations suggest that, in addition to the striking effects of ORF-based single nucleotide polymorphisms on TPMT activity, the VNTR within the 5'-flanking region of the TPMT gene also may modulate levels of RBC TPMT activity.

Prevalence and aetiology of leg ulcers in Ireland

BACKGROUND

The prevalence of leg ulcer disease in Ireland has been poorly documented.

AIMS

This study aimed to investigate the aetiology and prevalence of leg ulcers in one health district.

METHODS

All patients receiving healthcare for an active leg ulcer in the Mid-Western Health Board (MWHB) region of Ireland (population: 317,069) were identified in a defined two-month period. A cross-sectional survey of all healthcare workers providing care to patients with leg ulceration was carried out. Patients with leg ulcers of uncertain cause were invited for follow-up assessment to establish the underlying cause.

RESULTS

There were 389 patients with leg ulcers with a mean (standard deviation [SD]) age of 72.3 (11.1) years. The prevalence was 0.12% but it was 1.03% in patients aged 70 years and over. Women were twice as likely to be affected. Venous disease accounted for 81% of ulcers, and arterial disease for 16.3%, while ulceration due to diabetic neuropathy and rheumatoid vasculitis was unusual.

CONCLUSION

Leg ulcers are an important source of morbidity in our ageing population. Effective treatment programmes could diminish the impact of this debilitating disease on the health service.

Severe hypoglycemia as a presenting symptom of carbohydrate-deficient glycoprotein syndrome

We describe clinical, biochemical, and molecular findings in a 2(1/2)-year-old girl with a phosphomannose isomerase deficiency who presented with severe and persistent hypoglycemia and subsequently developed protein-losing enteropathy, liver disease, and coagulopathy. Six months of therapy with mannose supplementation resulted in clinical improvement and partial correction of biochemical abnormalities.

Broad screening test for sphingolipid-storage diseases

BACKGROUND

Lipid-storage diseases are collectively important because they cause substantial morbidity and mortality, and because they may present as dementia, major psychiatric illness, developmental delay, or cerebral palsy. At present, no single assay can be used as an initial general screen for lipid-storage diseases.

METHODS

We used a fluorescent analogue of lactosylceramide, called N-[5-(5,7-dimethylborondipyrromethenedifluoride)-1-pentanoyl]D- lactosylsphingosine (BODIPY-LacCer), the emission of which changes from green to red wavelengths with increasing concentrations in membranes, to examine the intracellular distribution of the lipid within living cells.

FINDINGS

During a brief pulse-chase experiment, the fluorescent lipid accumulated in the lysosomes of fibroblasts from patients with Fabry's disease, GM1 gangliosidosis, GM2 gangliosidosis (Tay-Sachs and Sandhoff forms), metachromatic leucodystrophy, mucolipidosis type IV, Niemann-Pick disease (types A, B, and C), and sphingolipid-activator-protein-precursor (prosaposin) deficiency. In control cells, the lipid was mainly confined to the Golgi complex. In a masked study, replicate samples of 25 of 26 unique cell lines representing ten different lipid-storage diseases, and 18 of 20 unique cell lines representing controls were correctly identified; the sensitivity was 96.2% (95% CI 80.4-99.9) and the specificity 90.0% (68.3-98.8).

INTERPRETATION

This method may be useful as an initial general screen for lipid-storage diseases, and, with modification, could be used for large-scale automated screening of drugs to abrogate lysosomal storage in various lipidoses. The unexpected accumulation of BODIPY-LacCer in several biochemically distinct diseases raises important questions about common mechanisms of cellular dysfunction in these disorders.

Capillary electrophoresis-based separation of transferrin sialoforms in patients with carbohydrate-deficient glycoprotein syndrome

The heterogeneity associated with protein glycoforms has been a challenge to analytical chemists and the subject of structure-function studies for biochemists since their presence in biological systems had been confirmed some three decades ago. Initial investigations led to discoveries of synthetic and degradative pathways, and brief forays into functional determination of the "glyco" portion on the protein activity in glycoproteins. Only recently has it come to our understanding that variations from the "normal" glycosylation patterns might be indicative of pathological states. The presence of certain transferrin (Tf) glycoforms in human serum has been shown to correlate with certain clinical syndromes. Hence, the ability to separate and quantitatively measure the various forms of human Tf has become increasingly important. It this study, we demonstrate that a simple method utilizing a DB-17-coated capillary to slow endoosmotic flow and a sieving buffer containing hydroxyethyl cellulose allows for the resolution of sialoforms of transferrin. An analysis time of less than eight minutes allows for baseline resolution of the lower sialoforms of Tf, presenting a simple, rapid test for carbohydrate-deficient transferrin (CDT). We demonstrate the utility of this methodology for the facile diagnosis of carbohydrate-deficient glycoprotein syndrome, and postulate that it may allow for the detection of other carbohydrate-deficient protein-related disease states.

What is the best biochemical test to diagnose acute pancreatitis? A prospective clinical study

OBJECTIVE

To determine which biochemical test is best to distinguish acute pancreatitis from other pancreatic and nonpancreatic diseases associated with hyperamylasemia.

DESIGN

We conducted a prospective clinical study of 836 consecutive patients who had a total serum amylase test requested by a physician during a 7-month period.

MATERIAL AND METHODS

Radioimmunoassay and enzymatic activity methods were used to measure pancreas-specific proteins of varied size, charge, and stability. In addition, scoring systems were used for the diagnosis of pancreatitis, and statistical analyses were done to determine sensitivity and specificity.

RESULTS

We found minor differences in sensitivity and specificity for diagnosis of acute pancreatitis among pancreatic isoamylase, phospholipase A2, colipase, lipase, and carboxylester lipase. Of these tests, the combination of isoamylase and phospholipase A2 had a small but statistically significant increased sensitivity (90%; 95% confidence interval [CI] = 74 to 98%) and specificity (93%; 95% CI = 91 to 95%) over isoamylase (90% and 92%, respectively; 95% CI = 90 to 94%) and phospholipase A2 (90% and 75%, respectively; 95% CI = 72 to 78%) alone for the diagnosis of acute pancreatitis.

CONCLUSION

Pancreas-specific proteins are satisfactory for diagnosing acute pancreatitis if the test is validated by the laboratory. Clinically, the slight advantage of using both isoamylase and phospholipase A2 does not outweigh the expense of performing two assays; we recommend using isoamylase to diagnose acute pancreatitis.

Plasma catechols and monoamine oxidase metabolites in untreated Parkinson's and Alzheimer's diseases

Prior studies have documented functional and pathological compromise of the peripheral sympathetic nervous system in patients with Parkinson's disease, suggesting the possibility of reduced catecholamine release into the circulation. We measured free plasma catechols in early and untreated patients with Parkinson's disease, but found no evidence of reduced concentrations, compared to control subjects or a group of patients with probable Alzheimer's disease. Rather, there was a significant elevation of plasma norepinephrine within the Parkinson's disease group. Furthermore, 6 of 15 untreated Parkinson's disease patients (40%) displayed markedly elevated plasma concentrations of the catecholamine MAO metabolites, DOPAC or DOPEG. Despite this finding, platelet MAO-B activity measured in these and all other Parkinson's disease patients fell well within the range of the control subjects, and was also statistically similar to the group with Alzheimer's type dementia. Plasma dopa levels were similar in all groups, whereas the majority of patients in the three groups had plasma free dopamine and epinephrine concentrations below the limits of detection. These trends toward increased, rather than decreased, circulating catechol concentrations suggest that peripheral sympathetic nervous system catecholamine production and release is not severely compromised in patients with early Parkinson's disease. In addition, we were unable to confirm certain previous reports of elevated MAO-B activity in patients with Parkinson's or Alzheimer's diseases.

Levodopa and deprenyl treatment effects on peripheral indices of oxidant stress in Parkinson's disease

The oxidant stress theory of Parkinson's disease (PD) hypothesizes that levodopa treatment may be potentially harmful and this is supported by studies demonstrating levodopa toxicity to cultured dopaminergic neurons. These in vitro experiments, however, lack the physiologic protective mechanisms present in vivo. Oxyradical damage to cell membranes liberates malondialdehyde, which we measured in the serum of 27 PD patients just before and after levodopa (with carbidopa) administration. We also measured plasma products of the two routes by which levodopa potentially generated oxyradicals: (1) 5-S-cysteinyl-dopa (derived from levodopa autoxidation), and (2) 3,4-dihydroxyphenylacetic acid (DOPAC), produced by monoamine oxidase (MAO) metabolism of dopamine. Following levodopa/carbidopa administration, both of these plasma products were markedly increased; however, the mean serum malondialdehyde concentration was unchanged and remained similar to the normal control group (N=15) value. Chronic treatment with the MAO-B inhibitor, deprenyl (N=16), was not associated with any differences in serum malondialdehyde or plasma 5-S-cysteinyl-dopa concentrations compared with those not treated with deprenyl (N=11). The post-levodopa rise of plasma DOPAC was only slightly attenuated with deprenyl therapy, consistent with a predominant MAO-A effect in the circulation and peripheral organs. Thus, in contrast to in vitro studies, we did not detect evidence of oxidative damage in the circulation following levodopa administration, despite marked increase in the products of dopamine oxidative metabolism.

Intravenous calcium chloride in the conversion of paroxysmal supraventricular tachycardia to normal sinus rhythm

This brief report describes several cases of paroxysmal supraventricular tachycardia that converted promptly to normal sinus rhythm within 1 to 2 minutes of receiving intravenous calcium salts as pretreatment in anticipation of verapamil therapy. A review of calcium's hemodynamic and dromotropic effects suggests that this probably was due to electrophysiological effects rather than mere coincidence. Calcium raises blood pressure, which may reflexively increase cardiac parasympathetic tone, and also has a direct slowing effect on atrioventricular conduction. Adenosine remains the drug of choice in the treatment of paroxysmal supraventricular tachycardia. However, in addition to preventing hypotension when used as pretreatment to verapamil, intravenous calcium itself may terminate supraventricular tachycardia.

Detection of autoantibodies to amylase by ELISA: comparison of detection of macroamylase and free autoantibody

New ELISAs for detecting macroamylase or free autoantibodies to amylase were tested with 48 samples that had been characterized by gel chromatography and electrophoresis. The macroamylase ELISA, with anti-IgG or anti-IgA for detection, detected macroamylase in 28 of 33 samples known to contain macroamylase (85% sensitivity), whereas the ELISA for free autoantibody to amylase was positive for only 11 samples. Specificities of both ELISAs were 93%. Among 28 true positives detected with the macroamylase ELISA, 22 contained IgA, 3 contained IgG, and 3 contained both immunoglobulins. Detection of IgM added no true positives. ELISA responses (y) were proportional to log [macroamylase concentration by chromatography (x)] from 0 to 1200 U/L: y = 5.15 x + 1.66; r = 0.72; Sy x = 1.65. As new tools for detecting macroenzymes consisting of enzyme-autoantibody complexes, the ELISAs show that some autoantibodies are detected more sensitively as antibody-antigen complexes than as free antibody.

Detection of autoantibodies to amylase by ELISA: comparison of detection of macroamylase and free autoantibody

New ELISAs for detecting macroamylase or free autoantibodies to amylase were tested with 48 samples that had been characterized by gel chromatography and electrophoresis. The macroamylase ELISA, with anti-IgG or anti-IgA for detection, detected macroamylase in 28 of 33 samples known to contain macroamylase (85% sensitivity), whereas the ELISA for free autoantibody to amylase was positive for only 11 samples. Specificities of both ELISAs were 93%. Among 28 true positives detected with the macroamylase ELISA, 22 contained IgA, 3 contained IgG, and 3 contained both immunoglobulins. Detection of IgM added no true positives. ELISA responses (y) were proportional to log [macroamylase concentration by chromatography (x)] from 0 to 1200 U/L: y = 5.15 x + 1.66; r = 0.72; Sy x = 1.65. As new tools for detecting macroenzymes consisting of enzyme-autoantibody complexes, the ELISAs show that some autoantibodies are detected more sensitively as antibody-antigen complexes than as free antibody.

Sanfilippo syndrome type A in two adult sibs

We report on 2 adult sibs with Sanfilippo syndrome type A (MPS IIIA; deficiency of heparin sulfamidase) who were less functionally impaired than other reported individuals with this disorder. These individuals expand our understanding of the range of clinical expression that one may see in Sanfilippo syndrome type A.

The macroenzymes: a clinical review

Macroenzymes are serum enzymes that have a higher molecular mass than the corresponding enzyme normally found in serum under physiologic or pathophysiologic conditions. Although no evidence convincingly indicates that macroenzymes cause disease or necessitate treatment, some patients with immunoglobulin-complexed enzyme disorders have previously been reported to have associated autoimmune diseases or malignant lesions. To address this issue, we reviewed the medical records of 42 patients in whom a macroenzyme had been detected during assessment at the Mayo Clinic between 1986 and 1990. Of these 42 patients, 21 had macro-creatine kinase, 10 had macro-lactate dehydrogenase, 6 had macro-aspartate aminotransferase, and 5 had macroamylase in the serum. Although the study group did not include all Mayo patients with this phenomenon, it represented a sufficient sample size to determine retrospectively whether specific dismissal diagnoses were present concurrently. The most common findings in this group of patients with macroenzymes were (1) advanced age (except for those with macro-aspartate aminotransferase), (2) cardiovascular disease (probably due to sampling bias), (3) malignant lesions (particularly in those with macro-creatine kinase), and (4) rheumatologic disease (in those with macro-lactate dehydrogenase). The immunoglobulin-complexed enzyme disorders are characterized by increased total serum enzyme levels that are often isolated and persistent. Physicians should be aware of the presence of macroenzymes so that invasive or costly procedures are not undertaken unnecessarily to determine the cause of increased serum enzyme levels.

Dexamethasone as adjuvant therapy for severe acute pharyngitis

STUDY OBJECTIVE

To determine the efficacy of dexamethasone as adjuvant therapy to improve pain relief in patients with severe, acute exudative pharyngitis.

DESIGN

Prospective, randomized, double-blinded, placebo-controlled clinical trial.

SETTING

Large, urban community hospital emergency department with an emergency medicine residency program.

TYPE OF PARTICIPANTS

Patients aged 12 to 65 years old with exudative pharyngitis and severe dysphagia/odynophagia. Patients with cancer, AIDS, diabetes mellitus, recent steroid use, pregnancy, or suspicion of peritonsillar abscess were excluded.

INTERVENTIONS

All patients received oral penicillin (500 mg Pen VK) or erythromycin (333 mg base) three times daily for ten days in addition to either 10 mg single-dose dexamethasone or saline placebo IM injection.

MEASUREMENTS AND RESULTS

Fifty-eight patients graded their initial degree of throat pain on a visual-analog scale that was 15 cm long and scored from 0 to 3.0 in 0.5-cm increments. Follow-up was obtained on 51 patients to determine their condition at 24 hours. At entry, there was no difference in age, weight, antibiotic assignment, or initial pain score between groups. Improvement in pain score (initial versus 24 hours) was 1.8 +/- 0.8 in the 26 patients of the dexamethasone group and 1.2 +/- 0.9 in the 25 patients of the placebo group (P < .05). Time to onset of pain relief was also faster in steroid-treated patients who demonstrated relief beginning at 6.3 +/- 5.3 hours, compared with 12.4 +/- 8.5 hours in the placebo group (P < .01). Of the 26 patients evaluated at seven days (13 in each group), time to complete lack of pain averaged 15.0 +/- 11.4 hours in the dexamethasone group and 35.4 +/- 17.9 hours in the placebo group (P < .02). Complications attributable to dexamethasone were not observed.

CONCLUSION

In patients with severe, acute exudative pharyngitis, single-injection dexamethasone adjuvant compared with placebo resulted in statistically and clinically significant improvement, as evidenced by more rapid onset and greater degree of pain relief.

Fluid resuscitation in traumatic hemorrhagic shock

Fluid resuscitation from traumatic hemorrhagic shock is a critical component of therapy for the critically injured patient. Therapy is aimed at restoring hemodynamic stability and oxygen delivery to tissues. The route and rate of fluid infusion, the temperature of the fluid infused, the type of asanguineous fluids chosen, and the timing of red cell transfusion may all impact substantially on the patient outcome. Complications of fluid therapy, especially edema, may be related to the choice of fluid infused. Identification of hypovolemia and methods to monitor tissue are important aspects of patient care.

Significance of mildly elevated creatine kinase (myocardial band) activity after elective abdominal aortic aneurysmectomy

The clinical significance of mildly elevated creatine kinase (CK) myocardial band (MB) enzyme levels in patients undergoing elective repair of an abdominal aortic aneurysm was evaluated retrospectively in 348 patients. For each patient, preoperative and postoperative electrocardiograms (ECGs) were interpreted blindly for left ventricular hypertrophy, ST segment abnormality, left bundle branch block, right bundle branch block, left axis deviation, atrial fibrillation, T wave abnormality, and Q waves. A total of 107 patients (31%) had postoperative CK-MB elevations of trace or greater; 37 had trace, 35 had 1% to 4%, and 35 had greater than or equal to 5% elevation. There was no difference in survival between those with trace and no CK-MB elevation. Patients with increased CK-MB (greater than or equal to 1%) values were more likely to have ECG abnormalities. The following ECG (either preoperative or postoperative) abnormalities were univariately related to decreased postoperative survival: left ventricular hypertrophy (P less than 0.001), ST segment abnormalities (P less than 0.001), left bundle branch block (P less than 0.001), the combination of right bundle branch block and left axis deviation (P = 0.006), Q wave infarction (P less than 0.001), and atrial fibrillation (P less than 0.001). There were 15 in-hospital deaths, and 333 patients were discharged and followed-up for a median of 4.6 years. There were 97 posthospitalization deaths, 61% of which were due to cardiac causes. Overall survival was associated with the degree of CK-MB elevation; the higher the CK-MB, the worse the survival.(ABSTRACT TRUNCATED AT 250 WORDS)

Rectal thiopental compared with intramuscular meperidine, promethazine, and chlorpromazine for pediatric sedation

STUDY OBJECTIVES

We studied the hypothesis that rectal thiopental is an effective agent for emergency department pediatric sedation and may have advantages over a more traditional regimen.

DESIGN

Rectal thiopental 25 mg/kg was compared with the combination of meperidine 2 mg/kg, promethazine 1 mg/kg, and chlorpromazine 1 mg/kg in a prospective, randomized, double-blinded study.

TYPE OF PARTICIPANTS

Children between 18 months and 6 years of age presenting to our teaching hospital ED for laceration repair were entered after the clinical decision was made to sedate. Patients with altered sensorium, medical contraindications to sedation, or medication allergy were excluded.

INTERVENTIONS

After informed consent, each patient received IM injection (drug combination or placebo) and rectal suspension (rectal thiopental or placebo) simultaneously.

MEASUREMENTS AND MAIN RESULTS

Vital signs, pulse oximetry, and pediatric Glasgow Coma Scores were recorded before and every 15 minutes after sedation until discharge. Intradermal lidocaine and suturing began when the patient appeared adequately sedated, and response was numerically scored. Patients were discharged when able to stand. Twenty-nine patients 34 +/- 13 months old were studied. Fifteen patients received rectal thiopental, and 14 received the drug combination. Analysis using the Wilcoxon two-sample test revealed no differences in age, sex, weight, or wound location between groups. The time course of sedation was different for the two treatment regimens. At 15 and 30 minutes after administration, patients who received rectal thiopental were more deeply sedated than those who received the drug combination, as evidenced by significantly lower Glasgow Coma Scores (P less than .05). Accordingly, time from medication administration to suturing was 29 +/- 12 minutes in the thiopental group and 54 +/- 33 minutes (P less than .01) in the drug combination group. Patients in the thiopental group also recovered more quickly and were discharged approximately one-half hour earlier than those in the drug combination group (89 +/- 25 vs 120 +/- 44 minutes, P less than .05). No difference in response to lidocaine injection or suturing was demonstrated between the groups. Laceration repair time was comparable between the groups. There were eight sedation failures (three of 15 in thiopental group and five of 14 in drug combination group, P = NS). Vital signs remained stable, no adverse reactions occurred, and no patient had decreased oxygen saturation to less than 95%.

CONCLUSION

Rectal thiopental is superior to this drug combination for pediatric sedation because it can be administered painlessly, has a more rapid onset and offset of action, and is of equal safety and efficacy at the dosage studied.

Clinical evaluation of high-performance affinity chromatography for the separation of bone and liver alkaline phosphatase isoenzymes

The newly described high-performance (HPLC) affinity chromatography method for the separation of human bone and liver alkaline phosphatase (ALP, EC 3.1.3.1) isoenzymes was clinically evaluated. The improved resolution of bone from liver isoenzyme and lower detection limit was achieved by conjugation of wheat-germ lectin (WGL) to a diol-bonded silica gel column, stepwise elution with N-acetylglucosamine (NAG) and post column derivatization using para-nitrophenyl phosphate substrate. To establish a reference interval, we measured bone ALP in 86 healthy women, ages 33 to 95 years. The normal reference interval is described by a piecewise linear regression on age (R2 = 0.20, P less than 0.01). For women less than or equal to 45 years, bone ALP, U/l = 8.495. For normal women between ages of 45 to 55 years, bone ALP, U/l = -12.765 + 0.472* age. If age greater than or equal to 55 years, then bone ALP, U/l 13.219. In all 10 patients with primary biliary cirrhosis, serum bone ALP levels were elevated. In addition, sera from 43 patients with diverse metabolic bone diseases were evaluated. As expected, the sera from all 6 patients with Paget's disease and 2 with osteolytic metastasis had bone ALP activity which was greater than 3 standard deviations (SD) from the mean. In all 10 patients with hypoparathyroidism, bone ALP levels were depressed. Only 1 of the 9 patients with glucocorticoid excess and 2 of the 7 patients with primary hyperparathyroidism had elevated bone ALP when compared to the 95% confidence interval for the normal range.(ABSTRACT TRUNCATED AT 250 WORDS)

Quantifying bone and liver alkaline phosphatase by the resolution of two-component inactivation data obtained with a centrifugal analyzer

In this method we use a linear equation to resolve two-component decay data from the urea inactivation of mixtures of alkaline phosphatase (EC 3.1.3.1) of liver and bone origin. The specificity for the bone/liver isoenzyme is enhanced by including L-phenylalanine in the urea reaction to inhibit the intestinal and placental forms. Bone and liver fractions are each quantified from results of a single run on the centrifugal analyzer. Total activity and the L-phenylalanine-inhibited fraction are measured on separate runs. A simplification of this method has been used in our laboratory for 14 years in performing greater than 80,000 analyses of clinical specimens. Speed, accuracy, and precision are improved over previous methods by this mathematical solution. Data reduction is automated through the use of a personal computer interfaced to the analyzer. With such systems generally available, this method can now be suggested as suitable for routine use to separate these and perhaps other isoenzyme mixtures.

Screening for biotinidase deficiency in children with unexplained neurologic or developmental abnormalities

To test the hypothesis that the frequency of biotinidase deficiency is greater in children with unexplained developmental delay or neurologic abnormalities than in the general population, we studied children seen at a large outpatient clinic over a four-year period who had one or more of these neurologic abnormalities and for whom no specific cause for their abnormalities could be found. The group totaled 274 children (163 boys; 111 girls) whose ages ranged from 2 weeks to 17 years. Characteristics were IQ/DQ, 30 to 70 in the 115 for whom scores were available; 41% had seizures; 15% had sensorineural hearing loss; 54% showed gross motor delay or ataxia; and 27% had decreased muscle tone. One patient with a classical clinical picture of biotinidase deficiency was diagnosed during the study period and was not included in the study. None of the patients with nonclassic findings had a deficiency of biotinidase activity. Our results suggest that biotinidase deficiency does not account for a large proportion of children with unexplained neurologic abnormalities or developmental delay. This does not negate the importance of biotinidase testing in children with clinical patterns specifically suggestive of the deficiency.

Liver- and bone-derived isoenzymes of alkaline phosphatase in serum as determined by high-performance affinity chromatography

To separate liver and bone alkaline phosphatase (ALP) isoenzymes in human serum, we used high-performance affinity chromatography (HPAC) on a column of wheat-germ lectin conjugated to 7-microns-diameter silica particles and an eluent containing N-acetyl-D-glucosamine (NAG). On-line spectrophotometric detection of ALP involved pumping diethanolamine-buffered p-nitrophenyl phosphate solution post-column. Bone and liver isoenzymes could be separated into two peaks with only 10% overlap when an exponential gradient was used. A linear-step gradient separated 80.9% of liver ALP and 91.6% of bone ALP in two distinct peaks. True bone and liver ALP peak areas for the linear-step gradient were determined by using correction factors, because each peak contained a co-eluted portion of the other ALP isoenzyme. The detection limit improved 10-fold over those of other techniques for ALP isoenzymes, owing to the relatively large sample that could be applied to the column. Correlation with a urea-inactivation procedure was reasonable for patients' serum samples (r = 0.98 and 0.79 for liver ALP and bone ALP, respectively).

Liver- and bone-derived isoenzymes of alkaline phosphatase in serum as determined by high-performance affinity chromatography

To separate liver and bone alkaline phosphatase (ALP) isoenzymes in human serum, we used high-performance affinity chromatography (HPAC) on a column of wheat-germ lectin conjugated to 7-microns-diameter silica particles and an eluent containing N-acetyl-D-glucosamine (NAG). On-line spectrophotometric detection of ALP involved pumping diethanolamine-buffered p-nitrophenyl phosphate solution post-column. Bone and liver isoenzymes could be separated into two peaks with only 10% overlap when an exponential gradient was used. A linear-step gradient separated 80.9% of liver ALP and 91.6% of bone ALP in two distinct peaks. True bone and liver ALP peak areas for the linear-step gradient were determined by using correction factors, because each peak contained a co-eluted portion of the other ALP isoenzyme. The detection limit improved 10-fold over those of other techniques for ALP isoenzymes, owing to the relatively large sample that could be applied to the column. Correlation with a urea-inactivation procedure was reasonable for patients' serum samples (r = 0.98 and 0.79 for liver ALP and bone ALP, respectively).

Isolated aspartate aminotransferase elevation due to macroenzyme formation with liver biopsy correlation

Serum aspartate aminotransferase (AST) has rarely been reported to complex with immunoglobulins, resulting in abnormally elevated serum activity. A similar phenomenon occurs with serum amylase, resulting in the more common entity of macroamylasemia. AST macroenzyme formation can occur in the presence or absence of liver disease and, at times, can lead to a false suspicion of liver disease. We describe the abnormal liver histology found in a healthy patient with isolated AST elevation due to AST macroenzyme formation.

Effect of long-term freezer storage, thawing, and refreezing on selected constituents of serum

We determined the effect of long-term freezer storage and repeated thawing and freezing of serum on concentrations of electrolytes (sodium, potassium, calcium, and phosphate), enzymes (aspartate aminotransferase, alkaline phosphatase, lactate dehydrogenase, and creatine kinase), total protein, tumor markers (carcinoembryonic antigen and alpha-fetoprotein), and other substances. Vials (1 ml) of frozen serum from a single blood drawing from 40 women with no breast disease and 70 with benign breast disease were analyzed annually from 1983 to 1987. Blood had been obtained from 40 subjects in 1978, 40 in 1980, and 30 in 1983. Thawing and refreezing studies were done in two ways: (1) serum samples from 30 subjects with benign breast disease were thawed at weekly intervals for 6 weeks and (2) serum samples from 30 patients with stage IV breast cancer were analyzed for alpha-fetoprotein and carcinoembryonic antigen, and serum specimens from 23 patients with benign breast disease and 7 control subjects were analyzed for lactate dehydrogenase and creatine kinase after thawing and keeping the samples at room temperature for up to 4 hours and then refreezing them. For measuring laboratory variability, duplicate samples were processed. Long-term storage (up to 10 years) and repeated thawing and refreezing did not affect the results of any tested constituents of serum. Although most measurements showed statistically significant variability over test cycles, these differences were thought to be due to laboratory variability.

Does exercise training alter myocardial creatine kinase MB isoenzyme content?

Skeletal muscle biopsies from highly trained endurance athletes have been shown to contain an increased percentage of the creatine kinase MB (CK-MB) isoenzyme, which has been attributed to continuous regeneration of the skeletal muscle fibers in response to exercise-induced injury. The purpose of this study was to determine whether myocardium undergoes a similar degenerative-regenerative process as a result of exercise training. Fifteen mongrel dogs underwent a 12-wk period of training (N = 8) or cage confinement (N = 7). The animals were then sacrificed, and samples of left and right ventricular myocardium were analyzed for total CK activity and CK-MB isoenzyme content. Percentages of CK-MB were slightly but insignificantly higher from both ventricles of exercise-trained as compared with cage-confined dogs: left ventricle, 4.6 +/- 0.6% vs 3.3 +/- 0.6%, respectively (P = 0.15); right ventricle, 4.0 +/- 0.4% vs 3.0 +/- 0.8%, respectively (P = 0.29). We conclude that chronic exercise training does not induce physiologically important degenerative changes in myocardium.

Alkaline phosphatase isoenzymes of liver and bone origin are incompletely resolved by wheat-germ-lectin affinity chromatography

We used wheat-germ-lectin affinity chromatography as a tool to investigate the structure of alkaline phosphatase (ALP, EC 3.1.3.1) and to obtain fractions enriched in either bone or liver ALP activity. Liver and bone isoenzymes in serum samples were incompletely resolved except that the activity in the nonretained fraction (fraction 1) always represented pure liver isoenzyme and constituted a larger percentage of total activity in pooled sera with increased liver ALP activity than in pooled sera with increased bone activity. In contrast, a more avidly retained ALP activity, presumably with high glycosylation, was found in human serum with high activity of bone ALP. Using a solid-phase immunoassay, we examined the fractions obtained from the wheat-germ-lectin-Sepharose 4B column to determine whether the isoenzyme preference of the monoclonal antibody was markedly influenced by the degree of glycosylation. Whether samples contained high proportions of liver or of bone isoenzyme activity, the nonretained fraction contained a higher percentage of liver ALP, whereas the more strongly bound fraction contained a higher percentage of bone ALP. Except for eluted fractions that either contained no detectable N-acetylglucosamine or the highest percentage of it, the avidity of the liver-isoenzyme-specific monoclonal antibody for ALP seemed to be independent of the degree of glycosylation, suggesting that the epitope for monoclonal antibody may be expressed in some structure other than the carbohydrate moieties.

Alkaline phosphatase isoenzymes of liver and bone origin are incompletely resolved by wheat-germ-lectin affinity chromatography

We used wheat-germ-lectin affinity chromatography as a tool to investigate the structure of alkaline phosphatase (ALP, EC 3.1.3.1) and to obtain fractions enriched in either bone or liver ALP activity. Liver and bone isoenzymes in serum samples were incompletely resolved except that the activity in the nonretained fraction (fraction 1) always represented pure liver isoenzyme and constituted a larger percentage of total activity in pooled sera with increased liver ALP activity than in pooled sera with increased bone activity. In contrast, a more avidly retained ALP activity, presumably with high glycosylation, was found in human serum with high activity of bone ALP. Using a solid-phase immunoassay, we examined the fractions obtained from the wheat-germ-lectin-Sepharose 4B column to determine whether the isoenzyme preference of the monoclonal antibody was markedly influenced by the degree of glycosylation. Whether samples contained high proportions of liver or of bone isoenzyme activity, the nonretained fraction contained a higher percentage of liver ALP, whereas the more strongly bound fraction contained a higher percentage of bone ALP. Except for eluted fractions that either contained no detectable N-acetylglucosamine or the highest percentage of it, the avidity of the liver-isoenzyme-specific monoclonal antibody for ALP seemed to be independent of the degree of glycosylation, suggesting that the epitope for monoclonal antibody may be expressed in some structure other than the carbohydrate moieties.

Concurrent assays of circulating bone Gla-protein and bone alkaline phosphatase: effects of sex, age, and metabolic bone disease

We measured the serum concentrations of 2 biochemical markers of bone formation, bone Gla-protein (BGP) and bone alkaline phosphatase (BAP), in 164 normal subjects and 164 patients with metabolic bone disorders. The data were reported as Z scores (deviation in SDs from the sex-specific age regression in normal subjects). Both serum BGP and BAP distinguished abnormalities well (mean Z scores for BGP and BAP, respectively) and gave concordant results in patients with hypoparathyroidism (-1.7, -1.4), hyperthyroidism (+1.1, +1.8), primary hyperparathyroidism (+3.6, +2.5), acromegaly (+1.2, +2.8), and postmenopausal osteoporosis (+0.4, +1.9). The 2 markers gave discordant results, however, in patients with glucocorticoid excess (-2.4, +0.9), Paget's disease (+1.8, +41.8), chronic renal failure (+16.3, +0.4), and osteolytic metastases (-1.4, +5.9). These discrepancies may have occurred because serum BGP and BAP concentrations reflect different aspects of osteoblast function or because there are differences in their clearance from the circulation. Consequently, more information is derived about the level of bone formation across the wide range of metabolic bone disorders when both biochemical markers are assayed.

Does low-energy helium-neon laser irradiation alter "in vitro" replication of human fibroblasts?

Cultured human fibroblasts were treated in a controlled, randomized manner to assess the effect of low-energy (0.9 mW) helium-neon (HeNe) laser irradiation on cellular proliferation. Two trials were performed: one with fibroblasts in the third to fourth passage and the other with fibroblasts in the 13th to 14th passage. In each trial, separate plastic petri dishes were inoculated with the cells, maintained in a 5% CO2-95% air atmosphere, and nourished with HB 102 media. Treatment began 48 h after inoculation with daily 60-s irradiations of the "treated" cultures over a 5-d period. Control cultures underwent the same handling but were not irradiated. A significant stimulative, or inhibitive, effect on replication was not found in either trial.

Effect of two anticoagulants on leukocyte yield and function, and on lysosomal enzyme activity

We compared acid citrate-dextrose (ACD-B) and heparin to determine which anticoagulant better preserves leukocytes for lysosomal enzyme assays if processing was done immediately or delayed for 24 h or more. Twenty normal subjects had blood drawn into tubes containing either ACD-B or heparin. The leukocytes were isolated by sedimentation in dextran (50 g/L) less than 2, 24, 48, and 72 h later. The most apparent difference was that cell counts indicated a 30% reduction in the number of leukocytes for ACD-B and a 95% reduction for heparin-treated cells at 48 h. The neutrophil function assay indicated that leukocyte processing must be done in less than 24 h regardless of the anticoagulant used, and that heparin is to be preferred. A comparison of heparin and ACD-B for maintenance of the activity of arylsulfatase A (EC 3.2.6.1) and hexosaminidase (EC 3.2.1.50) indicates that there is no effect of anticoagulant. However, at 48 h after venipuncture, there is an 80% reduction in the number of heparin-treated samples that are suitable for use in the assay. Those laboratories doing lysosomal enzyme tests on mailed specimens, which are most often greater than 24 h old, should use ACD-B as anticoagulant.

Effect of two anticoagulants on leukocyte yield and function, and on lysosomal enzyme activity

We compared acid citrate-dextrose (ACD-B) and heparin to determine which anticoagulant better preserves leukocytes for lysosomal enzyme assays if processing was done immediately or delayed for 24 h or more. Twenty normal subjects had blood drawn into tubes containing either ACD-B or heparin. The leukocytes were isolated by sedimentation in dextran (50 g/L) less than 2, 24, 48, and 72 h later. The most apparent difference was that cell counts indicated a 30% reduction in the number of leukocytes for ACD-B and a 95% reduction for heparin-treated cells at 48 h. The neutrophil function assay indicated that leukocyte processing must be done in less than 24 h regardless of the anticoagulant used, and that heparin is to be preferred. A comparison of heparin and ACD-B for maintenance of the activity of arylsulfatase A (EC 3.2.6.1) and hexosaminidase (EC 3.2.1.50) indicates that there is no effect of anticoagulant. However, at 48 h after venipuncture, there is an 80% reduction in the number of heparin-treated samples that are suitable for use in the assay. Those laboratories doing lysosomal enzyme tests on mailed specimens, which are most often greater than 24 h old, should use ACD-B as anticoagulant.