Comparative analysis of sucrose-embedding for whole-body zebrafish MSI by IR-MALDESI

Infrared matrix-assisted laser desorption electrospray ionization mass spectrometry imaging (IR-MALDESI) conventionally utilizes fresh-frozen biological tissues with an ice matrix to improve the detection of analytes. Sucrose-embedding with paraformaldehyde fixation has demonstrated feasibility as an alternative matrix for analysis by IR-MALDESI by preserving tissue features and enhancing ionization of lipids. However, investigating multi-organ systems provides broader context for a biological study and can elucidate more information about a disease state as opposed to a single organ. Danio rerio, or zebrafish, are model organisms for various disease states and can be imaged as a multi-organ sample to analyze morphological and metabolomic preservation as a result of sample preparation. Herein, whole-body zebrafish were imaged to compare sucrose-embedding with paraformaldehyde fixation against conventional fresh-frozen sample preparation. Serial sections were analyzed with and without an ice matrix to evaluate if sucrose functions as an alternative energy-absorbing matrix for IR-MALDESI applications across whole-body tissues. The resulting four conditions were compared in terms of total putative lipid annotations and category diversity, coverage across the entire m/z range, and ion abundance. Ultimately, sucrose-embedded zebrafish had an increase in putative lipid annotations for the combination of putative annotations with and without the application of an ice matrix relative to fresh-frozen tissues which require the application of an ice matrix. Upon the use of an ice matrix, a greater number of high mass putative lipid annotations (e.g., glycerophospholipids, glycerolipids, and sphingolipids) were identified. Conversely, without an ice matrix, sucrose-embedded sections elucidated more putative annotations in lower molecular weight lipids, including fatty acyls and sterol lipids. Similar to the mouse brain model, sucrose-embedding increased putative lipid annotation and abundance for whole-body zebrafish.

Maximized Spatial Information and Minimized Acquisition Time of Top-Hat IR-MALDESI-MSI of Zebrafish Using Nested Regions of Interest (nROIs)

Increasing the spatial resolution of a mass spectrometry imaging (MSI) method results in a more defined heatmap of the spatial distribution of molecules across a sample, but it is also associated with the disadvantage of increased acquisition time. Decreasing the area of the region of interest to achieve shorter durations results in the loss of potentially valuable information in larger specimens. This work presents a novel MSI method to reduce the time of MSI data acquisition with variable step size imaging: nested regions of interest (nROIs). Using nROIs, a small ROI may be imaged at a higher spatial resolution while nested inside a lower-spatial-resolution peripheral ROI. This conserves the maximal spatial and chemical information generated from target regions while also decreasing the necessary acquisition time. In this work, the nROI method was characterized on mouse liver and applied to top-hat MSI of zebrafish using a novel optical train, which resulted in a significant improvement in both acquisition time and spatial detail of the zebrafish. The nROI method can be employed with any step size pairing and adapted to any method in which the acquisition time of larger high-resolution ROIs poses a practical challenge.

Vitamin D deficiency promotes accumulation of bioactive lipids and increased endocannabinoid tone in zebrafish

Vitamin D is well known for its traditional role in bone mineral homeostasis; however, recent evidence suggests that vitamin D also plays a significant role in metabolic control. This study served to investigate putative linkages between vitamin D deficiency (VDD) and metabolic disruption of bioactive lipids by MS imaging. Our approach employed infrared-matrix-assisted laser desorption electrospray ionization MS imaging for lipid metabolite profiling in 6-month-old zebrafish fed either a VDD or a vitamin D-sufficient (VDS) diet. Using a lipidomics pipeline, we found that VDD zebrafish had a greater abundance of bioactive lipids (N-acyls, endocannabinoids [ECs], diacylglycerols/triacylglycerols, bile acids/bile alcohols, and vitamin D derivatives) suggestive of increased EC tone compared with VDS zebrafish. Tandem MS was performed on several differentially expressed metabolites with sufficient ion abundances to aid in structural elucidation and provide additional support for MS annotations. To confirm activation of the EC pathways, we subsequently examined expression of genes involved in EC biosynthesis, metabolism, and receptor signaling in adipose tissue and liver from VDD and VDS zebrafish. Gene expression changes were congruent with increased EC tone, with VDD zebrafish demonstrating increased synthesis and metabolism of anandamide compared with VDS zebrafish. Taken together, our data suggest that VDD may promote accumulation of bioactive lipids and increased EC tone in zebrafish.

A pitfall in diagnosing Cushing's disease: ectopic ACTH-producing pituitary adenoma in the sphenoid sinus

PURPOSE

To show a rare case of Cushing's disease and possible cause of failed transsphenoidal surgery.

METHOD

We report on a 50-year-old woman suffering from ACTH-dependent Cushing's syndrome. Endocrinological work-up including low-dose/high-dose dexamethasone test (Liddle-test) and CRH test were clearly compatible with pituitary origin. Although an MRI showed no pituitary tumor, CRH-stimulated petrosal sinus sampling revealed a significant central-peripheral gradient in ACTH concentrations, rendering Cushing's disease very likely. The patient underwent transsphenoidal surgery with negative exploration of the pituitary gland. After intraoperative re-evaluation of the preoperative MRI, a "polyp" at the bottom of the sphenoid sinus was identified. The intraoperative microscopic aspect as well as instantaneous sections and cytology of a biopsy confirmed an adenoma, which was then removed. Histological analysis demonstrated an ACTH-producing pituitary adenoma adjacent to respiratory mucous membrane consisting of ciliated epithelium with submucous connective tissue. Postoperatively, ACTH concentrations were decreased and intermittent hydrocortisone substitution treatment was initiated. At the 3-month follow up, Cushing's stigmata were found to be alleviated and the hydrocortisone dosage could be reduced.

CONCLUSION

Ectopic pituitary adenoma tissue causing Cushing's disease is extremely rare but a potential cause for surgical failure or re-evaluation.

Extracorporal low-density lipoprotein elimination by immunoadsorption

Low-density lipoprotein (LDL) apheresis has proven its therapeutic usefulness in patients who suffer from coronary heart disease but cannot achieve LDL cholesterol concentrations defined by the National Cholesterol Education Program guidelines. Immunoadsorption was the first commercially available apheresis technique. It is based on affinity chromatography. As with other apheresis techniques, immunoadsorption has specific advantages and disadvantages. These have to be taken into account when selecting an apheresis technique for the individual patient.

Hemorrheologic abnormalities in defined primary dyslipoproteinemias with both high and low atherosclerotic risks

Dyslipoproteinemias are associated with hemorrheologic abnormalities (elevated fibrinogen concentration, higher viscosity of plasma and blood). Epidemiologic data suggest that not only elevated lipoprotein concentrations (eg, low-density lipoprotein [LDL] cholesterol), but also hemorrheologic abnormalities could causally be involved in the atherosclerotic process. To elucidate potential effects of hemorrheological disturbances, we investigated patients suffering from primary hyperlipoproteinemias with both low (familial hypertriglyceridemia, n = 25) and high (type III hyperlipoproteinemia, n = 21; familial hypercholesterolemia, n = 19; mixed hyperlipoproteinemia, n = 19) atherosclerotic risk, as well as healthy controls (n = 49) in a cross-sectional design. Dyslipoproteinemias were classified by lipoprotein measurements (using ultracentrifugation), family history, and apolipoprotein E phenotype. Hemorrheology was characterized by the measurement of fibrinogen concentration, viscosity of plasma and blood at different shear rates, and red cell aggregation (RCA) at stasis and low shear. Fibrinogen concentration was lower in controls (2.38 +/- 0.09 g/L) compared with familial hypercholesterolemia (3.19 +/- 0.19 g/L), to type III hyperlipoproteinemia (3.02 +/- 0.12 g/L), to familial hypertriglyceridemia (2.95 +/- 0.21 g/L) and to mixed hyperlipoproteinemia (3.01 +/- 0.12 g/L) (P < .05, respectively) without differences between dyslipoproteinemia groups. Plasma viscosity was higher in patients with type III hyperlipoproteinemia (1.42 +/- 0.03 mPas), with familial hypertriglyceridemia (1.47 +/- 0.04 mPas), and with mixed hyperlipoproteinemia (1.43 +/- 0.02 mPas) compared with controls (1.29 +/- 0.01 mPas) (P < .05, respectively). After including 6 lipoprotein parameters in a general linear model, plasma viscosity, blood viscosity, and RCA were higher in familial hypertriglyceridemia compared with healthy controls and familial hypercholesterolemia (P < .05, respectively). As most of the hemorrheologic abnormalities were still significant after adjusting for lipoprotein concentrations, they seem to be at least partly independent from direct lipoprotein effects. Hemorrheologic abnormalities in familial hypertriglyceridemia (low atherosclerotic risk) were at least as marked as in dyslipoproteinemias with high atherosclerotic risk, suggesting that it might be most important to determine lipoprotein concentrations and to define exactly the type of dyslipoproteinemia for estimating the individual cardiovascular risk in these patients.

Resection of a branchiomeric paraganglioma at a rare extrapulmonary location

Thoracic paragangliomas are a rare cause of hypertension. We report the occurrence of a sporadic benign norepinephrine-producing branchiomeric paraganglioma in a 32-year-old man with paroxysms of hypertension. After localization by iodine 123-metaiodobenzyl-guanidine scintigraphy and magnetic resonance imaging, the paraganglioma was resected successfully below the right pulmonary artery through a right-sided posterolateral thoracotomy. The particular location was consistent with a branchiomeric paraganglioma in an extremely rare extrapulmonary location.

Influence of LDL apheresis on LDL subtypes in patients with coronary heart disease and severe hyperlipoproteinemia

Epidemiologic studies and in vitro experiments indicate that low density lipoprotein (LDL) subtypes differ concerning their atherogenic potential. Small, dense LDL are more atherogenic than large, buoyant LDL. LDL apheresis is a potent therapeutic modality to lower elevated LDL-cholesterol. It is unknown whether such therapy induces a shift in the LDL subtype distribution. In this study we evaluated the influence of LDL apheresis on the LDL subtype distribution in patients with CHD and familial hypercholesterolemia (FH, n = 22), combined hyperlipidemia (CHLP, n = 6), or Lp[a]-hyperlipoproteinemia (Lp[a]-HLP, n = 4) regularly treated by LDL apheresis (immunoadsorption (n = 14), HELP apheresis (n = 8), dextran sulfate adsorption (n = 7), cascade filtration (n = 3)). On the basis of 6 LDL subfractions (d 1.020;-1.057 g/mL) isolated by density gradient ultracentrifugation the LDL-density profile was determined in each patient before and after apheresis. There was a relative increase of LDL-subfractions 1, 2, and 3 (P < 0.01, P < 0. 05, and P < 0.01, respectively) and a concomitant decrease of LDL subfractions 5 and 6 (P < 0.05) after apheresis. Subgroup analysis indicates that the degree of the small, dense LDL reduction was much more prominent in patients with CHLP compared to patients with FH or Lp[a]-HLP, whereas the type of apheresis technique had no effect. The extent of small, dense LDL reduction correlated with the preapheresis concentrations of small, dense LDL and triglycerides but not with the extent of triglyceride reduction.We conclude that LDL apheresis not only decreases LDL mass, but also improves LDL-density profile, particularly in patients with CHLP.

[Obesity is not a character weakness. Leptin and twin research show: fat control is genetically regulated]

The results of recent research have confirmed the leptin control system. Leptin is produced in fatty tissue, crosses the blood-brain barrier, and signals repletion of fat stores. This in turn triggers a reduction in food intake and an increase in energy expenditure. While neuropeptide Y is known to play a central nervous mediator role, it is not certain whether leptin plays a marginal or a main role in the energy balance. Of at least equal, and possibly even greater practical/clinical importance are the results of research on the family and twins. For these reveal a tendency for weight increase and abdominal storage of fat and increased intake of calories to have a strong genetic link. The conclusions are a lowering of the expectations placed in reduction dieting, and an increase in efforts aimed at prevention.

Influence of protease inhibitor therapy on lipoprotein metabolism

OBJECTIVES

Protease inhibitors are efficient drugs as part of highly active antiretroviral therapy. They have been shown to cause hyper- and dyslipoproteinemia. Since antiretroviral therapy is able to delay disease progression and possibly extend life expectancy in HIV-infected individuals, the precise nature of serum lipid disturbances may become of clinical interest with respect to its atherogenicity and to finding treatment options.

DESIGN

We investigated prospectively, in 19 subsequent HIV-positive male patients (mean age 42 +/- 13 years), multiple lipid parameters in plasma, before and during treatment with a protease inhibitor (nelfinavir, ritonavir, or indinavir) and two nucleoside analogue reverse transcriptase inhibitors (NRTI). The median (range) treatment duration was 22 (7-40) weeks. 12 patients were treatment-naive; 7 had already NRTI medication at baseline.

RESULTS

Total cholesterol increased by 28 mg dL-1 (95% CI: + 7 to + 48, baseline 158 +/- 53, P = 0.01), triglycerides increased by 96 mg dL-1 (+ 22 to + 170, baseline 152 +/- 91, P = 0.014), HDL cholesterol was unchanged, LDL cholesterol was slightly but not significantly elevated, VLDL cholesterol increased by 20 mg dL-1 (+ 9 to + 31, baseline 33 +/- 21, P = 0.001), VLDL triglycerides increased by 86 mg dL-1 (+ 22 to + 150, baseline 128 +/- 91, P = 0. 01). The ratio of total cholesterol to HDL cholesterol increased by 1.2 (+ 0.7 to + 1.7, baseline 4.8 +/- 1.5, P = 0.0001) and the ratio of HDL2 to HDL3 decreased by 0.06 (-0.02 to -0.09, baseline 0.47 +/- 0.11, P = 0.005). (Conversion factors, mg dL-1 to mmol L-1: 0.0259 for cholesterol, 0.0114 for triglycerides.)

CONCLUSIONS

The data indicate that the predominant feature of dyslipidemia under protease inhibitors is an increase in triglyceride-containing lipoproteins. This observation is in accordance with the hypothesis of increased apoptosis of peripheral adipocytes, release of free fatty acids and subsequent increased synthesis of VLDL. The lipid profile, based on the ratio of total cholesterol to HDL cholesterol and the ratio HDL2 to HDL3, is significantly more atherogenic.

The prevention education program (PEP). A prospective study of the efficacy of family-oriented life style modification in the reduction of cardiovascular risk and disease: design and baseline data

We describe design and baseline data of the Prevention Education Program (PEP), a home-based and family-oriented intervention program, aimed to assess and improve cardiovascular risk factors in school children and their families during an intervention period of 10 years. Started in 1994 in the German town of Nuremberg, currently 37 elementary schools (22 control and 15 intervention schools) are enrolled including 1740 families (1740 first graders, 3046 parents, and 1521 siblings). Major cardiovascular risk factors as well as dietary behavior are evaluated yearly using structured interview, physical examination, laboratory analysis, and seven-day-dietary protocols. The intervention package is applied to all families from intervention schools using regular home visits, health curricula and group sessions. Primary outcome is any reduction in cardiovascular risk factors by dietary intervention and health education compared to the control group getting only written information on the individual risk profile. The presented baseline data showing a high prevalence of cardiovascular risk factors in adults and in their children underline the need for such an intervention program in Germany.

Lipoprotein (a) metabolism estimated by nonsteady-state kinetics

Lipoprotein (a) [Lp(a)] is a low-density lipoprotein (LDL) particle with an additional apolipoprotein named apo(a). The concentration of Lp(a) in plasma is determined to a large extent by the size of the apo(a) isoform. Because elevated Lp(a) concentrations in plasma are associated with risk for premature coronary heart disease it is important to determine whether variations in production or catabolism mediate differences in Lp(a) concentration. We determined metabolic parameters of Lp(a) in 17 patients with heterozygous familial hypercholesterolemia or severe mixed hyperlipidemia by fitting a monoexponential function to the rebound of Lp(a) plasma concentration following LDL-apheresis. In 8 of those 17 patients this was done twice following two different aphereses. Although this approach allows one to estimate metabolic parameters without the use of a tracer, it requires several major assumptions such as that apheresis itself does not change production or catabolism of Lp(a) and that Lp(a) metabolism can be described by a single compartment. One apheresis decreased Lp(a) concentration by 59.1+/-8.3%. The fractional catabolic rate (FCR) was 0.16+/-0.12 d(-1) and production rate 6.27+/-5.26 mg x kg(-1) x d(-1). However, observed (concentration before first apheresis) and predicted steady-state concentrations differed considerably (more than 20%) in 9 of 17 patients, indicating that not all assumptions were fulfilled in all patients. Production rate but not FCR was correlated with Lp(a) plasma concentration (r2 = 0.43, P = 0.004) and molecular weight of apo(a) (r2 = 0.48, P = 0.011), which confirms radiotracer experiments showing that variations in Lp(a) plasma concentrations are due to differences in production not catabolism. When parameters were estimated twice in a subgroup of eight patients, satisfactory reproducibility was observed in six patients. Although parameters determined on two occasions correlated well, only FCR was concordant (intraclass correlation coefficient). Thus, despite the limitations arising from the assumptions implicit to this method, metabolic parameters of Lp(a) can be estimated from the rebound of plasma concentration following apheresis.

Comparison of sequences for depicting bone marrow alterations in osteomyelitis applied in a low field strength magnetic resonance imaging system

OBJECTIVE/PATIENTS

To investigate the efficacy of standard sequences of a low field system for the detection of osteomyelitis, we tested T1wI pre and post i.v. contrast, T2w and fat suppressed IR sequences.

DESIGN

On the basis of clinical and laboratory evidence, pathology reports, and three phase granulocyte scintigraphy, osteomyelitis was diagnosed in 18 of 21 patients with Charcot's joints. A consecutive low and high field magnetic resonance (MR) scan confirmed osteomyelitic bone marrow changes in the same osseous regions. These 18 diabetic patients were then studied on a 0.2 Tesla dedicated MR system (Esaote ArtoScan) using T1wI (SE: relaxation time (TR) 520/echo time (TE) 24: axial and coronal) before and after i.v. application of 0.1 mmol/l Gd-DTPA/kg BW, T2w imaging (TSE: TR 3500/TE 80 or TR 2000/TE 120: axial), and fat suppressed inversion recovery (IR) imaging (short tau inversion recovery (STIR): TR 3000/TE 30/TI 80 or inversion recovery gradient echo (IRGE)/fat suppressed IRGE (GEFS): TR 1000/TE 16m 80: coronal).

RESULTS

The SE T1w sequence showed a significantly higher contrast-to-noise ratio (CNR) before administration of i.v. contrast. The TSE T2w pulse sequence demonstrated bone marrow changes superiorily utilizing a TE of 120 ms (CNR = 16.5+/-2.7 compared to 5.5+/-2.5 with TE = 80 ms). The IRGE showed a higher CNR than the standard STIR (CNR = 19.2+/-2.5 compared to 12.4+/-2.9).

CONCLUSION

Fat suppressed IRGE imaging and longer TE in T2w TSE sequences result in a significantly better CNR in osteomyelitis. This way, using optimized sequences, low field systems are apt to depict bone marrow changes in the course of osteomyelitis.

Effects of acipimox on haemorheology and plasma lipoproteins in patients with mixed hyperlipoproteinaemia

AIMS

Epidemiological data have shown that haemorheological disorders are associated with an increased risk of atherosclerosis. We evaluated the effect of the nicotinic acid derivative acipimox on haemorheological and lipid parameters in 18 patients with mixed hyperlipoproteinaemia using a randomized, double-blind, placebo-controlled, cross-over study protocol.

METHODS

Patients (7 women, 11 men, aged 49.3+/-3.0 years) were investigated with acipimox (dose adjusted to weight, 500 or 750 mg daily) compared with placebo treatment each for 12 weeks. Lipid parameters, whole blood viscosity, plasma viscosity, fibrinogen, and red cell aggregation at native and standardized (0.45) haematocrit as well as red cell filterability were measured at baseline, at week 12 (change of therapy), and at week 24.

RESULTS

Total cholesterol concentration (8.30+/-0.32 vs 8.72+/-0.36 mmol/l(-1)) and apolipoprotein B (198.5+/-9.9 vs 217+/-9.9 mg dl(-1)) were significantly lower (P<0.05) during acipimox therapy compared with placebo, no significant changes were observed for triglycerides and low-density lipoprotein [LDL] cholesterol. However, total high-density lipoprotein [HDL] cholesterol (1.24+/-0.05 vs 1.10+/-0.05 mmol l(-1), P<0.001) as well as HDL2 and HDL3 cholesterol (P<0.05) were significantly higher during acipimox therapy. The LDL cholesterol to HDL cholesterol ratio significantly improved during acipimox therapy (4.63+/-0.25 vs 5.49+/-0.26, P<0.001). Red cell aggregation at native and standardized haematocrit were the only haemorheological parameters which improved during acipimox therapy in comparison with placebo (shear rate 3 s(-1):10.69+/-0.40 vs 11.50+/-0.44 U, P<0.05, for native red cell aggregation; 10.40+/-0.36 vs 11.28+/-0.39 U, P<0.05, for standardized red cell aggregation).

CONCLUSIONS

We conclude, that the cardiovascular risk profile improves during acipimox therapy due to an elevation in HDL cholesterol and its subfractions as well as a decrease in red cell aggregation.

Prophylactic thyroidectomy in 75 children and adolescents with hereditary medullary thyroid carcinoma: German and Austrian experience

When mutations of the RETproto-oncogene were found in 1993 to account for hereditary medullary thyroid carcinoma (MTC), surgeons obtained the opportunity to operate on patients prophylactically (i. e., at a clinically asymptomatic stage). Whether this approach is justified, and, if so, when and to which extent surgery should be performed remained to be clarified. A questionnaire was sent to all surgical departments in Germany and Austria. All of the patients who fulfilled the following criteria were enrolled: (1) preoperatively proved RET mutation; (2) age </= 20 years, (3) clinically asymptomatic thyroid C cell disease; and (4) TNM classification pT0-1/pNX/pN0-1/M0. Seventy-five patients were identified, and fifteen mutations were detected in six codons. Two adolescents had unilateral pheochromocytomas as part of the multiple endocrine neoplasia II (MEN-II) syndrome. No hyperparathyroidism was noted. All patients underwent total thyroidectomy, and 57 patients went on to have lymph node dissection. Parathyroid glands were removed in 34 patients and autografted in 11. Histopathology revealed MTC in 46 patients (61%, youngest 4 years); C cell hyperplasia (CCH) only was detected in the other 29 patients. Three patients had lymph node metastases (LNMs) the youngest being age 14 years. Calcitonin levels were not useful for differentiating between CCH and MTC, but in all patients with LNMs at least the stimulated calcitonin levels were assayed. After surgery, five patients (6.7%) sustained permanent hypoparathyroidism, and one patient (1.3%) had a permanent unilateral recurrent nerve palsy. All but three patients (96%) were biochemically cured. In conclusion, prophylactic total thyroidectomy can be performed safely in experienced centers. We recommend prophylactic total thyroidectomy at age 6. Cervicocentral lymph node dissection should be included when calcitonin levels are elevated or if patients are older than 10 years. Bilateral lymph node dissection should be performed if LNMs are suspected or when patients with elevated calcitonin are older than 15 years.

Course of islet autoantibody titers during Ig-immunoadsorption in a patient with newly diagnosed type 1 diabetes

The purpose of this study was to determine whether and to what extent diabetes-specific autoantibodies can be removed from the plasma by Ig-immunoadsorption therapy. We followed the course of islet cell antibodies (ICA), insulin antibodies (I[A]A), glutamic acid decarboxylase antibodies (GADA) and antibodies to the protein tyrosine phosphatase IA-2 (IA2A) in a patient with newly diagnosed insulin-dependent diabetes mellitus (IDDM) under multiple immunoadsorption treatments over 6 months. Autoantibodies were not removed from the plasma as efficiently as expected when compared to the removal of total immunoglobulin (IgG). Whereas IgG levels were lowered by 70-90% through each immunoadsorption treatment, antibodies to insulin were reduced by an average of 83%, IA2A by 36% and GADA by only 9% directly after treatment. ICA were > 320 JDF U at diabetes onset and remained above this level. During the 6 months of multiple immunoadsorption therapies, I[A]A levels showed a 24-fold increase due to stimulation of insulin antibody production by exogenous insulin substitution, IA2A levels remained unchanged (average 6% increase), and GADA levels were reduced by an average of 39% compared to antibody titers at onset. All four antibodies were highly positive in the eluate from the immunoadsorption columns. We showed that antibodies to pancreatic islet cells can be reduced by immunoadsorption, but as for plasmapheresis the effect is incomplete and transient for most of the antibodies. If there is clinical benefit through immunoadsorption therapy--as has been shown for newly diagnosed IDDM patients treated with plasmapheresis--our data suggest that this may be due to factors other than the sufficient removal of antibodies.

A new hot spot for mutations in the ret protooncogene causing familial medullary thyroid carcinoma and multiple endocrine neoplasia type 2A

One hundred and eighty-one families with multiple endocrine neoplasia type 2A (MEN-2A) or familial medullary thyroid carcinoma (FMTC) have been investigated for mutations in the ret protooncogene in Germany. In 8 families with FMTC or MEN-2A, no mutation could be detected in the cysteine-rich domain encoded in exons 10 and 11 of the ret protooncogene. DNA sequencing of additional exons (no. 13-15) revealed rare noncysteine mutations in 3 families (codons 631, 768, and 844). In contrast to these rare events, heterozygous missense mutations in exon 13, codons 790 and 791, were found in 5 families (4 with MTC only; 1 family with MTC and pheochromocytoma) and 11 patients with apparently sporadic tumors. Two different mutations in codon 790 (TTG-->TTT, TTG-->TTC; Leu790Phe) and one mutation in codon 791 (TAT-->TTT; Tyr791Phe) created a phenylalanine residue. We conclude that codons 790 and 791 of the ret protooncogene represent a new hot spot for FMTC/MEN-2A causing mutations. With the discovery of these considerably common mutations in codons 790 and 791 and the identification of some rare mutations, 100% of the German FMTC/MEN-2A families could be characterized by a mutation in the ret protooncogene.

Sporadic pheochromocytomas are rarely associated with germline mutations in the vhl tumor suppressor gene or the ret protooncogene

Pheochromocytoma is a tumor that may occur sporadically or may be a manifestation of a hereditary disease, such as von Hippel-Lindau disease (VHL) and multiple endocrine neoplasia (MEN) type 2. As patients with VHL or MEN type 2 are at risk to develop multiple tumors, they must be distinguished from sporadic cases. We determined the incidence of VHL and MEN type 2 among 62 German patients diagnosed with pheochromocytoma without a history of a hereditary disease. Germline analyses of the vhl gene and exons 10, 11, and 13 of the ret protooncogene were performed by PCR, single strand conformation polymorphism, enzyme digestion, or sequencing. Two patients (3%) showed vhl mutations (95% confidence interval, 1-11%). One patient showed loss of the MspI restriction site at nucleotides 712/713. Another patient had a C/T change at an intronic site that was also detected in 2 of his offspring. No mutations were detected in the ret protooncogene (97.5% confidence interval, 0-6%). In Germany, most sporadic pheochromocytomas are not due to VHL or MEN type 2. Therefore, clinical work-up in patients with pheochromocytoma without signs of hereditary disease is not recommended. However, because the costs of genetic screening are relatively low, and each index case allows optimal care for family members, molecular testing might be cost-effective.

Apolipoprotein E polymorphism has no independent effect on plasma levels of lipoprotein(a)

Previous studies show conflicting results concerning an influence of apolipoprotein E (apo E) phenotype on lipoprotein(a) (Lp(a)) plasma levels. We speculated that it is not the apo E phenotype itself but rather its effect on plasma lipid concentrations that might influence Lp(a) levels. In 1562 subjects concentrations of triglycerides, LDL-cholesterol and Lp(a) were measured by standard laboratory methods. Apo(a) and apo E isoforms were determined by sodium dodecyl sulfate gel electrophoresis and isoelectric focusing, respectively, followed by immunoblotting. An univariate analysis revealed a significant influence of apo(a) isoforms, apo E phenotype, triglycerides and LDL-cholesterol on Lp(a) plasma levels (ANOVA: P < 0.001, P < 0.02, P < 0.001 and P < 0.001, respectively). In a multivariate analysis, however, the influence of the apo E phenotype was no longer significant (P>0.10), whereas apo(a) isoforms, LDL-cholesterol quintiles and triglyceride quintiles explained 29.2, 2.8 and 1.0% of the variation of the Lp(a) levels (for all three variables: P < 0.001). We conclude that apo E polymorphism does not exert an independent effect on Lp(a) concentrations. Any influence is mediated through the effect of apo E polymorphism on plasma lipids.

A duplication of 12 bp in the critical cysteine rich domain of the RET proto-oncogene results in a distinct phenotype of multiple endocrine neoplasia type 2A

Activating germline mutations in the cysteine-rich domain of the RET proto-oncogene are found in >92% of the cases of multiple endocrine neoplasia type 2A (MEN2A) and 85% of familial medullary thyroid carcinoma (FMTC). In virtually 100% of patients with identified mutations one of five cysteines is altered by a missense mutation. In a MEN2A family with 14 affected and 11 unaffected living members, hypercalcemia was diagnosed in eight patients and histological evaluation revealed parathyroid hyperplasia in all cases examined (10/10). No member of this family showed any evidence for the existence of pheochromocytoma. This is the first documentation of a family without pheochromocytoma but with a high incidence of parathyroid disease. Genetic analysis revealed the presence of an unusual heterozygous mutation in exon 11 of the RET proto-oncogene representing a duplication of 12 bp resulting in the insertion of four amino acids between codon 634 (Cys) and 635 (Arg), thus creating an additional cysteine residue.

Low lipoprotein (a) levels during acute viral hepatitis

High serum concentrations of lipoprotein (a) [Lp(a)] are considered a risk factor for premature atherosclerosis. Besides apolipoprotein B-100, Lp(a) consists of apolipoprotein (a) [apo(a)], which shows a remarkable size polymorphism. The serum concentration of Lp(a) is considerably influenced by this apo(a) phenotype. Because Lp(a) is synthesized in the liver, we wondered whether and to what extent Lp(a) levels might be affected by acute liver disease. We compared Lp(a) serum concentrations in 74 patients (54% male, 46% female; mean age, 46 years) with acute viral hepatitis (32, 28, and 14 with hepatitis A, B, and C, respectively) with those in 404 healthy controls (57% men, 43% women; mean age, 47 years). In addition, the intraindividual course of Lp(a) concentration during and after acute hepatitis was followed in a subgroup of 23 patients (15, 6, and 2 with hepatitis A, B, and C, respectively). During acute hepatitis, median Lp(a) concentrations in the patient group were significantly diminished compared with controls (7 vs. 17 mg/dL;P < .0001, Mann-Whitney test). Any bias by an unequal isoform distribution was excluded because there was no significant difference in the isoform distribution between patients and controls (P > .10, chi2 test). Furthermore, the decrease in Lp(a) concentration during acute hepatitis was independent of the molecular weight of the apo(a) isoform. Longitudinally observed patients showed a marked increase in Lp(a) concentration during convalescence (7 to 32 mg/dL;P < .0001, Wilcoxon test). Our results show that acute hepatitis is associated with decreased Lp(a) serum levels. Further studies are needed to evaluate whether Lp(a) serum concentration might be clinically useful as a parameter of liver function.

Effects of n-3 fatty acids and fenofibrate on lipid and hemorrheological parameters in familial dysbetalipoproteinemia and familial hypertriglyceridemia

There is increasing evidence that hemorrheological abnormalities are associated with an enhanced risk of atherosclerosis. The n-3 fatty acids (n-3-FA) have been shown to have beneficial effects on atherosclerosis in patients with dyslipoproteinemias. We studied 23 patients with elevated plasma triglycerides to evaluate the influence of fish oil and fenofibrate therapy on hemorrheological parameters (15 patients with familial hypertriglyceridemia [FHTG] and eight with familial dysbetalipoproteinemia [FDL]). The patients (one woman and 22 men aged 45.7 +/- 2.0 years) were treated with increasing doses of n-3-FA (1.8 to 3.6 g/d: 0.9 to 1.8 g eicosapentaenoic acid and 0.6 to 1.2 g docosahexaenoic acid) for 8 weeks. Lipid parameters, whole-blood viscosity at different shear rates, plasma viscosity, fibrinogen concentration, and red blood cell aggregation (RCA) were measured at baseline and at weeks 2, 4, 8 (end of n-3-FA therapy), and 12. Compliance was ensured by measuring plasma concentrations of eicosapentaenoic acid and docosahexaenoic acid. After 12 weeks, patients began treatment with fenofibrate (250 mg daily); investigations were performed again at week 20. Total triglycerides (from 6.90 +/- 1.70 to 3.61 +/- 0.78 mmol/L in FDL and 7.44 +/- 1.50 to 4.15 +/- 0.55 in FHTG), very-low-density lipoprotein (VLDL) triglycerides, and VLDL cholesterol were significantly decreased with n-3-FA therapy in both groups (P < .05). In FHTG, low-density lipoprotein (LDL) cholesterol increased significantly (from 2.75 +/- 0.28 to 3.97 +/- 0.35 mmol/L, P < .01); in FDL, total cholesterol decreased (from 9.76 +/- 1.32 to 7.34 +/- 1.07 mmol/L, P < .05). No significant changes were observed in hemorrheological parameters, except for reduced RCA with 3.6 g n-3-FA in FHTG. However, with fenofibrate therapy, in addition to comparable lipoprotein changes seen with fish oil, fibrinogen levels and plasma and blood viscosity decreased in patients with FDL. We conclude that n-3-FA and fenofibrate have comparable effects on lipid parameters in patients with FDL and FHTG. Because of additional beneficial effects on hemorrheological parameters, fenofibrate may be preferred for the treatment of FDL.

Mutations of the ret protooncogene in German multiple endocrine neoplasia families: relation between genotype and phenotype. German Medullary Thyroid Carcinoma Study Group

It has been suggested that not only the position but also the nature of the mutations of the ret protooncogene strongly correlate with the clinical manifestation of the multiple endocrine neoplasm type 2 (MEN 2) syndrome. In particular, individuals with a Cys634-Arg substitution should have a greater risk of developing parathyroid disease. We, therefore, analyzed 94 unrelated families from Germany with inherited medullary thyroid carcinoma (MTC) for mutation of the ret protooncogene. In all but 1 of 59 families with MEN 2A, germline mutations in the extracellular domain of the ret protein were found. Some 81% of the MEN 2A mutations affected codon 634. Phenotype-genotype correlations suggested that the prevalence of pheochromocytoma and hyperparathyroidism is significantly higher in families with codon 634 mutations, but there was no correlation with the nature of the mutation. In all but 1 of 27 familial MTC (FMTC) families, mutations were detected in 1 of 4 cysteines in the extracellular domain of the ret protooncogene. Half of the FMTC mutations affected codon 634. Mutations outside of codon 634 occurred more often in FMTC families than in MEN 2A families. In all but 1 of 8 MEN 2B patients, de novo mutations in codon 918 were found. These data confirm the preferential localization of MEN 2-associated mutations and the correlation between disease phenotype and the position of the ret mutation, but there was no correlation between the occurrence of hyperparathyroidism or pheochromocytoma and the nature of the mutation.

Isolated familial pheochromocytoma as a variant of von Hippel-Lindau disease

Inherited pheochromocytomas are often part of familial syndromes, especially multiple endocrine neoplasia type 2 (MEN 2), retinal cerebellar hemangioblastomatosis [von Hippel-Lindau (vHL) disease] or neurofibromatosis type 1. It is not clear whether isolated familial pheochromocytoma exists as a separate clinical entity. In a family with pheochromocytomas in three generations and with at least seven affected members, we investigated by clinical and genetic analyses the presence or absence of associated conditions. The clinical investigations included ophthalmological and radiological studies for von Hippel-Lindau disease (magnetic resonance imaging of the brain, computed tomography of the abdomen, and direct ophthalmoscopy after mydriasis) and annual calcitonin stimulation tests for C cell disease in five members who agreed to regular follow-up. Besides the pheochromocytomas (so far, these have been multiple in five of seven individuals) no definite second associated condition was found. Genetic analysis did not identify any MEN 2-specific RET protooncogene point mutations (which are present in 97% of MEN 2a families). However, despite the complete absence of other clinical manifestations of the vHL disease (besides pheochromocytomas), a previously undescribed germline missense mutation in the vHL tumor suppressor gene was found (C775G transversion with a predicted substitution of a leucine by a valine at codon 259 in the putative vHL protein). We conclude that in this family the sole occurrence of pheochromocytoma is a variant of vHL disease.

[Effects of a vegetarian life style on health]

A vegetarian diet has a positive effect on various risk factors for coronary artery disease: these include usually lower average body weight, lower total and LDL cholesterol levels, and lower blood pressure. In conjunction with a generally more healthy way of life (more exercise, less alcohol and tobacco use), vegetarians have roughly 30% reduction in overall mortality. The prevalence of bronchial, colon and breast cancer is also lower. In particular in its strict form (total vegetarianism or veganism), a vegetarian regimen may lead to deficiency disorders, in particular vitamin B12 deficiency, which may occur especially in vegetarian children, pregnant or lactating women. Overall, however, a vegetarian regimen has a more beneficial effect on health than the usual Central European diet.

Lipoprotein(a) concentrations and phenotypes in controls and patients with hypercholesterolemia or hypertriglyceridemia

Lipoprotein(a) [Lp(a)] concentrations are known to be stable under various dietary and drug regimens. Little is known about the influence of hyperlipoproteinemia on Lp(a) levels. Therefore, we investigated Lp(a) concentrations and apolipoprotein(a) [apo(a)] polymorphism in 147 patients with hypertriglyceridemia and in 93 patients with hypercholesterolemia and compared them with 404 subjects without hyperlipoproteinemia (controls). Despite a similar apo(a) isoform and phenotype distribution, Lp(a) concentrations differed significantly (P < .0001) between the three groups. The median Lp(a) level in control subjects was 17 mg/dL (mean, 38 mg/dL), compared with 38 mg/dL (mean, 56 mg/dL) in patients with hypercholesterolemia and 9 mg/dL (mean, 21 mg/dL) in those with hypertriglyceridemia. These differences persisted after exclusion of 61 subjects with coronary heart disease. The inverse correlation between the molecular weight of the apo(a) isoforms and the Lp(a) concentration was preserved within each group (P < .001), but for every molecular weight range studied the level of Lp(a) was always higher in patients with hypercholesterolemia and always lower in those with hypertriglyceridemia than in controls. We conclude that hypertriglyceridemia or hypercholesterolemia have profound--but divergent--influences on the concentration of Lp(a).

Healing of protein losing hypertrophic gastropathy by eradication of Helicobacter pylori--is Helicobacter pylori a pathogenic factor in Ménétrier's disease?

Hypertrophic gastropathy--that is, Ménétrier's disease--was found, in a retrospective analysis, to be associated with Helicobacter pylori in more than 90% of patients. It is proposed that hypertrophic gastropathy represents a special form of H pylori gastritis in these patients. A case is described of a 28 year old woman with Ménétrier's disease associated with proved protein loss from the stomach. Treatment with cimetidine for more than three years had little benefit when colonisation by H pylori was detected. Density of H pylori colonisation and activity of gastritis, which was also present in the first biopsy specimens taken five years ago, were more pronounced in the body than in the antrum, which is in agreement with the characteristics of H pylori gastritis found in other cases with Ménétrier's disease. A 14 day antibacterial treatment course with 750 mg amoxicillin three times a day combined with 40 mg omeprazole three times a day was started in April 1991. This resulted in eradication of H pylori and the return to normal of giant folds and the mucosal histology. Serum protein concentrations returned to normal within six weeks and remained normal at two endoscopies during a two year follow up. This case report suggests that a subgroup of the patients with Ménétrier's disease may be healed by the eradication of H pylori.

The waist-to-hip ratio corrected for body mass index is related to serum triglycerides and high-density lipoprotein cholesterol but not to parameters of glucose metabolism in healthy premenopausal women

Android obesity is associated with metabolic disorders, but the causality of this relationship remains unclear. We investigated the association of body mass index (BMI) and waist-to-hip ratio (WHR) with hormones, glucose tolerance, insulin sensitivity, serum lipoproteins, and the serum activity of hepatic enzymes in 40 healthy premenopausal women (BMI 19.2-46.1, mean 32.6 +/- 1.3 kg/m2; WHR 0.68-1.01, mean 0.82 +/- 0.02). BMI correlated with WHR (r = 0.52, P < 0.01). After correction for WHR, BMI was negatively correlated with high-density lipoprotein cholesterol and positively with total and very low density lipoprotein triglycerides, insulin sensitivity, blood glucose, serum insulin and glucagon. After adjustment for BMI, WHR was significantly associated with high-density lipoprotein cholesterol, total and very low density lipoprotein triglycerides, and the serum activities of hepatic enzymes but not with insulin sensitivity, blood glucose, serum insulin, or glucagon. According to these results, body fat distribution assessed by WHR is related to hypertriglyceridemia and alterations in hepatic function such as a fatty liver. WHR is not primarily related to glucose metabolism in healthy premenopausal women without preexisting metabolic disorders such as glucose intolerance. Therefore the observable association between android obesity and manifest impairment in glucose metabolism may develop secondarily during persisting hyperinsulinemia, which itself is primarily related to obesity. Thus an android body fat distribution may rather be an accompanying feature than a predictor of impaired glucose tolerance and insulin resistance.

Three-year treatment of familial heterozygous hypercholesterolemia by extracorporeal low-density lipoprotein immunoadsorption with polyclonal apolipoprotein B antibodies

Familial hypercholesterolemia is a disorder of lipid metabolism associated with a highly increased risk for cardiovascular disease. Since in such patients even combined drug therapy often fails to decrease low-density lipoprotein (LDL) cholesterol levels sufficiently, extracorporeal LDL elimination has been developed. We treated eight adult patients with LDL immunoadsorption using antibodies against apolipoprotein B without additional lipid-lowering drug therapy for 3 years; this procedure was performed at weekly intervals. By one treatment session, LDL cholesterol and lipoprotein(a) levels were decreased by 55%. Under regular treatment, mean LDL cholesterol levels of 165 mg/dL between two consecutive treatment sessions could be reached, compared with 522 +/- 24 mg/dL before any treatment. As high-density lipoprotein (HDL) cholesterol levels increased under regular treatment, the LDL/HDL cholesterol ratio decreased from 13.4 to 3.4. Positive influences on plasma and whole-blood viscosity as well as on erythrocyte aggregation also seem to be beneficial with regard to retarding atherosclerosis. Very-low-density lipoprotein (VLDL) levels were reduced by approximately 50% after treatment, accompanied by a marked increase of lipoprotein lipase (LPL) and hepatic triglyceride lipase (HTGL) activity. The effects of LDL apheresis on hemostasis, complement activation transport proteins, and hematological parameters were found to be small. In addition, no side effects amounting to any major clinical relevance occurred in any of the patients. After 3 years of LDL apheresis, a decrease in the frequency of anginal chest pain and ST segment depression on exercise testing and a marked reduction of tendon xanthoma size were observed.

Influence of fiber, xylitol and fructose in enteral formulas on glucose and lipid metabolism in normal subjects

To verify the benefit of nonglucose carbohydrates and fiber in enteral formula diets we studied the postprandial metabolism of eight healthy subjects after the intake of two helpings (25 g carbohydrates each) of five commonly used enteral formulas over 4 h. There were no significant differences in postprandial concentrations of blood glucose among the formulas. The area under the curve of postprandial insulin values, however, was significantly smaller after consumption of the fructose-containing formula (1948 +/- 285 microU min ml-1, P < 0.05) than after fiber-free (3222 +/- 678 microU min ml-1) or two fiber-containing products (2664 +/- 326 microU min ml-1, P < 0.05; and 3040 +/- 708 microU min ml-1, P < 0.05). The insulin area of the xylitol-containing formula (2307 +/- 364 microU min ml-1) was significantly smaller compared to the fiber-free product (P < 0.05). In addition, we found the postprandial increase in triglycerides to be significantly higher after the xylitol-containing formula (from 0.93 +/- 0.14 to 1.25 +/- 0.22 mmol/l) than after the fiber-free product (from 0.82 +/- 0.13 to 0.97 +/- 0.16 mmol/l, P < 0.05) or the two fiber-containing products (from 0.88 +/- 0.16 to 0.96 +/- 0.18 mmol/l, P < 0.05; and from 0.80 +/- 0.08 to 0.95 +/- 0.10 mmol/l, P < 0.05). We conclude that a patient with type II diabetes may benefit from replacing glucose and glucose-equivalent carbohydrates with fructose or xylitol.

Lipoprotein(a) in diabetes mellitus

Epidemiologic studies have identified lipoprotein(a) (Lp(a)) as an independent risk factor for atherosclerosis, mainly for coronary heart disease. Atherosclerosis is the most common cause of death in diabetic patients, but there is little information available concerning the importance of Lp(a) in these patients. We compared the presence or absence of late diabetic complications with Lp(a) serum concentrations in 224 patients (82 IDDM, 142 NIDDM). Lp(a) distribution was skewed as described for non-diabetic patients. Despite highly significant differences for total cholesterol, total triglycerides, HDL-cholesterol, VLDL-cholesterol and VLDL-triglycerides (P < 0.001) and for LDL-cholesterol (P < 0.01) Lp(a) concentrations were similar in NIDDM and IDDM (mean: 27 vs. 30, median: 12 vs. 21 mg/dl, P = 0.10). Diabetic polyneuropathy, autonomic neuropathy, nephropathy, peripheral occlusive disease, diabetic gangrene and coronary heart disease were not associated with raised Lp(a) values. Non-insulin-dependent patients with retinopathy exhibited higher Lp(a) concentrations in serum than those without this complication. This significant association was lost when duration of diabetes was taken into account by logistic regression. We conclude, that other risk factors surpass the significance of Lp(a) in diabetic patients.

[Characteristics of obese patients in intensive care]

BASIC REMARKS

The frequency of overweight, together with the associated increase in morbidity--in particular coronary heart disease--means that such patients often require intensive care.

MAIN POINTS DISCUSSED

The particular features of intensive care of obese patients are the increased risk of aspiration pneumonia (in the presence of lowered pH and elevated gastric juice volume), respiratory insufficiency caused by a reduction in expiratory reserve volume, and a greater incidence of thrombosis and embolism. Ventricular hypertrophy and dilatation results in a reduced cardiac reserve. A clinically unrecognized insulin resistance may become manifest during intensive care. Digoxin, theophylline and aminoglycosides, commonly with a low therapeutic spectrum, when administered on the basis of weight, may lead to dangerously high serum concentrations in the overweight.

CONCLUSIONS

At a weight of more than about 100 kg, it must generally be expected that the compensatory mechanisms of the body are exhausted and that there will be an increased susceptibility to additional disorders of homeostasis.

[Effects of beta blockers on lipoprotein metabolism]

PROBLEM

With respect to prevention of its most common complication--mortality from coronary heart disease--treatment of hypertension had disappointed. It is possible that this is due to negative effects of antihypertensives on lipid metabolism.

MAJOR TOPICS

The effects of beta blockers on lipid metabolism can be differentiated principally, in accordance with the classification of beta blockers into those with and those without intrinsic sympathomimetic activity (ISA), as also selectivity and non-selectivity. Thus, non-selective beta blockers with no ISA usually lead to an increase in triglycerides of 25% to 30%, and a decrease in HDL cholesterol of about 15%. On average, beta-1 selective blockers result in a smaller increase in triglycerides. Beta blockers with ISA, in contrast, are largely neutral vis-à-vis lipid metabolism. In the individual case, in particular in the presence of hyperlipoproteinemia, the effects cannot be reliably predicted.

CONCLUSIONS

Lipoprotein concentrations should be monitored during treatment with beta blockers. If necessary, a change in the agent employed is recommended. In the case of prevention of a second myocardial infarction, for which various studies have unequivocally shown a reduction in mortality associated with treatment with beta blockers with no ISA, these side effects will, however, be accepted--with the exception of extreme changes--for a limited period of time.

Treatment of primary chylomicronemia due to familial hypertriglyceridemia by omega-3 fatty acids

Primary familial forms of chylomicronemia can lead to acute life-threatening complications, especially acute pancreatitis. The main aim of therapy is to avoid this so-called chylomicronemia syndrome. In 12 patients with primary chylomicronemia due to familial hypertriglyceridemia, the addition of 2.16 g omega-3 fatty acids over 4 weeks and 4.32 g for 8 weeks resulted in a decrease of serum triglyceride levels from 1,624 +/- 333 to 894 +/- 241 mg/dL after 12 weeks. Cholesterol and triglyceride levels in the chylomicron fraction were reduced concomitantly, the apolipoprotein B-100/B-48 ratio increased, very--low-density lipoprotein (VLDL) triglycerides, VLDL cholesterol, and total cholesterol levels decreased, and low-density lipoprotein (LDL) cholesterol showed a tendency to increase, but this finding did not reach significance. High-density lipoprotein (HDL) cholesterol levels remained unchanged, as did the levels of apolipoproteins A-I, A-II, and E, and lipoprotein(a). Apolipoprotein B levels decreased significantly. The decrease of triglyceride levels to still-elevated concentrations was accompanied by a substantial decrease in plasma and whole-blood viscosity and erythrocyte aggregation, which reached normal values. As in chylomicronemia, complications usually occur at triglyceride levels higher than 1,500 mg/dL; patients can still profit from treatment with omega-3 fatty acids, even though triglyceride levels are still substantially elevated. No clinically relevant side effects occurred, with the exception of the manifestation of diabetes mellitus in one patient, which could be reversed after discontinuation of treatment.

Granulocytes and three-phase bone scintigraphy for differentiation of diabetic gangrene with and without osteomyelitis

OBJECTIVE

In diabetic gangrene, concomitant osteopathy and soft-tissue infection often render laboratory and roentgenographic signs unreliable as indicators of osteomyelitis. In this situation, scintigraphic methods can be helpful.

RESEARCH DESIGN AND METHODS

Relying on the long-term clinical course as the final indicator of presence or absence of osteomyelitis, we prospectively compared in 31 patients three-phase bone scintigraphy with either indium-labeled autologous granulocytes (n = 20) or 123I-labeled antibodies against granulocytes (n = 11).

RESULTS

Three-phase bone scintigraphy and imaging with indium-labeled autologous granulocytes yielded sensitivities and specificities of 95 and 70% for bone scintigraphy and 77 and 100% for granulocyte scintigraphy, respectively. One patient with severe angiopathy and proved osteomyelitis had a negative bone scintigraphy but a positive scintigraphy with labeled antibodies against granulocytes. One patient with aseptic bone necrosis presented with a formally false positive result with both methods.

CONCLUSIONS

In contrast to former retrospective studies, three-phase bone scintigraphy compares very well with granulocyte scintigraphy. The care of most patients can be managed with clinical data and this widely available scintigraphic method.