Paravertebral schwannoma with high uptake of fluorodeoxyglucose on positron emission tomography.

A paravertebral mass was discovered in a 27-year-old woman, while investigating a painful shoulder and arm. CT, MRI and fine needle aspiration cytology (FNAC) pointed in the direction of a benign mass, but positron emission tomography (PET) showed a high uptake of [(18)F]fluorodeoxyglucose (FDG), which was indicative of a malignant lesion. Pathological analysis of the thoracoscopically resected tumour gave us the final diagnosis of a benign schwannoma. This report demonstrates that a high uptake of FDG in a non-malignant mediastinal tumour is possible.

Pseudodystrophy. A conversion disorder mimicking reflex sympathetic dystrophy.

The authors suggest some criteria by which pseudodystrophy and reflex sympathetic dystrophy, although sharing some similar clinical features, can be distinguished as two different conditions, each requiring its own approach and management. The most important distinction is found on bone scintigraphy. In reflex sympathetic dystrophy the bone scan shows a typical increased tracer uptake (at least during stages I and II); in pseudodystrophy there is a normal or decreased tracer uptake in the affected region. Moreover the vascularization is increased in reflex sympathetic dystrophy stage I, whereas in pseudodystrophy hypovascularization is found from the beginning. The clinical features, as well as the results of technical investigations, psychological evaluation and treatment of 4 patients with pseudodystrophy are presented. The importance of distinguishing this condition from reflex sympathetic dystrophy is stressed.

The effect of stress on gastric emptying rate measured with a radionuclide tracer.

BACKGROUND/AIMS: Stress can delay gastric emptying rate. This phenomenon has not yet been investigated with a physiological solid test meal or a regional analysis. METHODOLOGY: We investigated the gastric emptying rate in beagle dogs using a radio-labeled solid test meal and a gamma camera. The transport to an unknown environment served as a stress stimulus. This offers the advantage to mimic fairly well the clinical situation just before a diagnostic or therapeutic procedure. Control values were obtained after the third investigation, in which all dogs were accustomed to the environment. RESULTS: Regional analysis of the emptying curves from the whole gastric region revealed that the length of the lag phase increased with stress, but the post-initial emptying rate remained unchanged. Emptying of the fundus changed hardly, but the antropyloral motor activity decreased during stress. CONCLUSIONS: Gastric emptying rate is impeded during stress. It is necessary to limit the unnatural stress-stimuli, in order to mimic the clinical situation. Measurement techniques that influence directly gastric emptying or act as a stress-stimulus by themselves are undesirable. A radionuclide solid test meal is preferable and a regional analysis reveals the impairment of the antral motility as the mechanism of the delay of gastric emptying.

Gastric emptying rate for solid and for liquid test meals in patients with dyspeptic symptoms after partial gastrectomy and after vagotomy followed by partial gastrectomy.

BACKGROUND/AIMS: Gastric emptying rate for solid and for liquid test meals was investigated retrospectively in patients with longstanding epigastric distress after partial gastrectomy, either as primary treatment or after failure of vagotomy for peptic ulcer in order to find an explanation for the postoperative symptoms. METHODOLOGY: Radionuclide-labeled liquid and solid test meals were used to evaluate gastric emptying rate, at least one year after surgery. RESULTS: The lag phase for liquid test meals disappeared in all operated patients. Partial gastrectomy usually lead to fast emptying but this resective procedure, if performed after vagotomy, lead to stasis in a significant number of patients. Gastric emptying rate for solids increased in only a few of these symptomatic patients. In most of them however, there was a normal to decreased emptying rate. If a vagotomy had preceded the resective procedure, gastric emptying rate decreased significantly. CONCLUSIONS: In all these symptomatic patients, gastric emptying had been disturbed for at least one type of test meal. This makes investigation for both meals necessary, especially since there is a lack of correlation. Furthermore, if vagotomy fails to prevent ulcer recurrence, one should carefully consider all options before performing partial gastrectomy since gastric emptying rate after these consecutive procedures worsens considerably.

Comparison of anterior and geometric mean liquid and solid gastric emptying rates in dogs and in patients after partial gastrectomy.

OBJECTIVE: The purpose of this study was to determine if geometrical correction is necessary in the study of gastric emptying rate (GER) for liquids, using a low-energy radionuclide, such as 99mTc. Solid test meals were considered the reference. METHODS: Both solid and liquid GERs were investigated using regional analysis. Anterior data were compared with geometrically corrected values in 15 dogs and 9 partial gastrectomy patients. RESULTS: Anterior and geometrically corrected measurements differed significantly for solid food in the whole gastric region and in the antrum. Geometrically corrected values differed slightly from anterior data after partial gastrectomy. No difference was found for liquid food. Liquids redistributed much faster than solids within the stomach. CONCLUSION: Measurement of GER using a single-phase liquid meal does not require geometrical correction. This is due to the rapid intragastric redistribution of the liquid. Geometrical correction for solid food can be omitted only after partial gastrectomy.

Gastric emptying rate measurement after vertical banded gastroplasty.

BACKGROUND: In vertical banded gastroplasty (VBG), a small proximal gastric pouch is created, which is believed to fill rapidly and to empty slowly. METHODS: In 13 patients who underwent VBG, gastric emptying rate was measured. A radiolabelled solid test meal was used before and 2 weeks after operation. From a region of interest above the whole stomach, the proximal pouch and the distal stomach, half emptying time as well as retention percentage were derived. RESULTS: All patients experienced early satiety and gastric fullness after ingestion of a small test meal. The proximal pouch emptied rapidly. The evacuation of the test meal from the whole gastric region as well as the distal stomach were not altered significantly by the operation. CONCLUSION: VBG is a safe operation which reduced weight significantly. Early satiety, however, induced by this technique, cannot be explained alone by slow emptying of the proximal pouch. The nature of the outlet of the pouch as well as the behavior of its wall must be considered.

What is reflex sympathetic dystrophy?

In the literature there is no unanimity with respect to the diagnosis of reflex sympathetic dystrophy (RSD). Frequently, the diagnosis is established on mere clinical grounds. In our opinion, however, bone scintigraphy is of major importance for the diagnosis. Using this examination, true RSD can be clearly differentiated from other conditions which are incorrectly diagnosed and treated as RSD. If the bone scan is not suggestive of RSD, the clinical picture, radiological examination and vascular scan may lead to the correct diagnosis. This may be a pseudodystrophy, in which a hypovascularization is found right from the start, while in true RSD there is initially a hypervascularization. Other conditions which may be confused with RSD are causalgia, neurotic compulsive postures, hysterical conversion, malingering and even self-mutilation. In the spontaneous course of RSD three phases can be distinguished. Stage I is the warm or hypertrophic phase, stage II the cold or atrophic phase. Per definition the third phase corresponds to stabilization or, in rare instances, to healing. By means of the vascular scan the correct stage can be determined, and the results of treatment evaluated. Finally it should be noted that in children the condition is completely different from true RSD, as it concerns a pseudodystrophy or disuse-related dystrophy. This condition may also be seen in adults and adolescents, usually females. The bone scan is always negative. In this way bone scintigraphy constitutes the means to answer the question as to what RSD is and what it is not. An algorithm for the differential diagnosis is presented.

Gastric emptying of liquid meals after anterior gastric stapling and posterior truncal vagotomy in beagle dogs: discrepancy with results for solid food.

BACKGROUND/AIMS: Since the development of highly selective vagotomy (HSV), simplified procedures such as posterior truncal vagotomy with anterior gastric wall stapling (PTV-AGS) became available to achieve parietal cell denervation. The purpose of this investigation was to detect possible gastric emptying disturbances due to complete vagotomy of the posterior gastric wall and to stapling of the anterior stomach wall. METHODOLOGY: Six female dogs, undergoing HSV, were compared with six others, in which PTV-AGS was performed. Radionuclide labeled liquid test meals were used to evaluate gastric emptying rate (GER) and results were compared with solid test meal emptying. RESULTS: A small, statistically insignificant fastening of liquid gastric emptying was seen early after HSV, as well as after PTV-AGS, and persisted one year after operation. There proved to be a striking lack of correlation between the GER-results after liquid versus solid meals. CONCLUSION: Just as after HSV, gastric emptying rates of liquid meals after PTV-AGS do not show a statistical difference as compared with preoperative values. Both operations therefore do not induce clinically important gastric motility changes. Separate test meals with liquid and solid food prove to be necessary in order to detect such changes.

Adenosine technetium-99m sestamibi single-photon emission tomography for the assessment of jeopardized myocardium early after acute myocardial infarction. Paradoxical scintigraphic underestimation of jeopardized myocardium in patients with a severe infarct-related stenosis.

This study investigated the value of technetium-99m sestamibi scintigraphy in identifying patients at risk for post-infarct ischaemia (=jeopardized myocardium), especially within the reperfused infarct region. In 51 patients with a recent (<1 month) myocardial infarction, adenosine 99mTc-sestamibi single-photon emission tomography (SPET) and dobutamine stress echocardiography (DSE) were performed and correlated with the presence of significant coronary artery stenosis [% diameter stenosis (DS) >50%] on quantitative coronary angiography. Regional perfusion activity was analysed semi-quantitatively (score 0-4) on a 13-segment left ventricular model. DSE was used for the estimation of the infarct size (low-dose DSE) and for concomitant evaluation of ischaemia (high-dose DSE). A reversible perfusion defect within the infarct region was observed in 20 of the 37 patients with a significant infarct-related lesion (sensitivity of 54%) and only in one patient without a significant infarct-related lesion (specificity of 93%). Further analysis revealed that the scintigraphic assessment of jeopardized myocardium was fairly good in patients with a moderate (DS 51%-64%) infarct-related stenosis but was inadequate in patients with a severe (DS>/=65%) infarct-related stenosis (sensitivity of 80% vs 36%, P<0.01), while the echocardiographic detection of ischaemia was not influenced by stenosis severity (sensitivity of 73% in both subgroups). This scintigraphic underestimation of jeopardized myocardium was mainly related to a severely impaired myocardial perfusion under baseline conditions, as was evidenced by a significantly more severe rest perfusion score in the infarct region in patients with a severe stenosis as compared to those with a moderate stenosis (average score: 1.5+/-0.7 vs 2.1+/-0.6, P<0.01), while infarct size on echocardiography was similar for both subgroups. It may be concluded that early after an acute myocardial infarction, adenosine 99mTc-sestamibi SPET may underestimate reperfused but still jeopardized myocardium, particularly in patients with a severe infarct-related stenosis. In these patients the evaluation of the ischaemic burden on rest-stress scintigraphy is hampered by the presence of a severely impaired myocardial perfusion in resting conditions.

Analytical and clinical evaluation of a method to quantify bone alkaline phosphatase, a marker of osteoblastic activity.

An immunoradiometric assay (IRMA), involving specific monoclonal antibodies (Ostase, Hybritech) and agarose electrophoresis (Isopal, Beckman), two methods for quantification of serum bone alkaline phosphatase (ALP), a marker for osteoblastic activity, were analytically and clinically compared in 293 patients: 79 with end-stage renal failure treated with hemodialysis and 214 with malignant disease. Acceptable within-assay precision was obtained for the IRMA method: 82.5% of the duplicate determinations had a coefficient of variation (CV) < 5%. Curve fitting characteristics were bad and the sensitivity was better than the one mentioned by the manufacturer. Overall correlation between the two methods was good (r = 0.92), except (a) for low values of bone ALP and (b) in some samples with high total liver ALP activity. Low bone ALP determined with the IRMA (< 5 micrograms/L) was confirmed by electrophoresis (< 22 U/L), but ALP activity determined by electrophoresis to be low (< 22 U/L) was not correlated with the IRMA results. After standardizing our results by computing z-values for bone ALP, delta z (= zostase - zelectrophoresis) was significant correlated with liver ALP activity (r = 0.73, P < 0.0001). We conclude that the IRMA for quantifying bone ALP is acceptable. However, when high values for bone ALP are found with the Ostase method, confirmation by electrophoresis remains mandatory to rule out cross-reactivity with high amounts of liver ALP.

Comparison of one first and three second generation methods for the determination of CA 125.

The monoclonal antibody, OC125 (Centocor, Inc, Malvern, Pa) was the basis for the first generation, one step immunoradiometric assays (IRMA) to detect the CA 125 glycoprotein. Recently, two step IRMA's were developed, the CA 125 II generation assays. In these new assays the CA 125 capture antibody is the M11 monoclonal antibody coated on a solid phase and the OC125 monoclonal antibody is used as the tracer. We compared analytically and clinically one first generation radioassay, and three second generation assays (two radioassays and one ELISA). The ELISA method showed the best within-assay precision and the best curve fitting characteristics. In the clinical comparison, none of the correlations between the first and the second generation methods really satisfied, however the cut off level of 35 U/ml was confirmed. The four CA 125 assays do not yield equal results. As a consequence, the evolution of CA 125 serum concentration during disease monitoring is not reliable when different determination methods are used consecutively.

Comparison of radionuclide labelled test meals versus endoscopy in the preoperative assessment of the gastric outlet patency.

A series of 39 patients with peptic ulcer disease is investigated with respect to gastric outlet obstruction. Two diagnostic tools are compared, namely endoscopy and evaluation of radionuclide meal emptying. Endoscopic obstruction was qualified as non passage of a 14 mm gastroscope. Gastric emptying reduction was considered clinically relevant when half emptying times exceeded 60 minutes for solids and 12 minutes for liquids. Comparison of both techniques of radionuclide meal emptying with endoscopy showed a poor correlation (accuracy 15/28), especially when liquid gastric emptying versus endoscopy was concerned.

Coronary flow reserve during coronary angioplasty in patients with a recent myocardial infarction: relation to stenosis and myocardial viability.

OBJECTIVES: In the present study, we examined post-stenotic coronary flow before and after percutaneous transluminal coronary angioplasty (PTCA) in patients with and without a recent myocardial infarction (MI) and related it to stenosis severity and residual viability. BACKGROUND: Post-stenotic coronary blood flow velocity reserve (CFVR) has been used with success to estimate functional stenosis severity in patients with stable angina. However, in patients with a recent MI, the impaired coronary vasodilator response of the reperfused myocardium may substantially alter the flow dynamics of the infarct-related artery. METHODS: Distal coronary flow velocities were recorded before and after PTCA in 36 patients at day 13 +/- 7 (mean +/- SD) after acute MI and in 38 patients without MI. The CFVR was assessed by the ratio of distal hyperemic to baseline average peak velocity, using a 0.014-in. Doppler guide wire. Stenosis severity was analyzed by quantitative coronary angiography, and infarct size was assessed scintigraphically. RESULTS: For similar angiographic stenosis severity, pre- and post-PTCA values of CFVR were significantly lower in patients with than without MI: 1.22 +/- 0.26 versus 1.50 +/- 0.45 before PTCA (p < 0.05) and 1.72 +/- 0.43 versus 2.21 +/- 0.74 after PTCA, respectively (p < 0.01). Although CFVR increased significantly (p < 0.0001) after angiographically successful PTCA in both study groups, abnormal CFVR (< or = 2.0) was still observed in 80% of patients with MI and in 44% of those without MI (MI vs. no MI, p = 0.001). Patients with an extensive infarction (relative infarct size > or = 50%) and those with a small infarction (relative infarct size < 50%) had comparable levels of post-PTCA CFVR (1.6 +/- 0.3 vs. 1.8 +/- 0.5, p = NS). Among a variety of factors, angiographic stenosis severity was the most important determinant of CFVR in both study groups. CONCLUSIONS: In patients with a recent MI, CFVR was significantly lower than in those without MI, both before and after PTCA. Besides the presence of this postreperfusion-related impairment of the coronary vasodilating response, CFVR was mainly influenced by stenosis severity and not by residual viability.

Stimulatory effects of L-5-hydroxytryptophan on postdexamethasone beta-endorphin levels in major depression.

Recently it has been shown that acute administration of 200 mg L-5-hydroxytryptophan (L-5-HTP) PO may increase post-dexamethasone (DST) adrenocorticotropic hormone (ACTH) and cortisol levels in major, but not minor, depressed subjects. This study aimed to examine the effects of 200 mg L-5-HTP PO on post-DST beta-endorphin levels in the same depressed subjects. It was found that in major, but not minor, depressed subjects, L-5-HTP significantly increased post-DST beta-endorphin concentrations as compared to placebo. The L-5-HTP-induced post-DST beta-endorphin responses were significantly higher in major than in minor depressed subjects. There was a significant and positive relationship between L-5-HTP-induced post-DST beta-endorphin and ACTH or cortisol responses. There was a significant and positive relationship between L-5-HTP-induced post-DST beta-endorphin values and the Hamilton Depression Rating Scale (HDRS) score. The results show that the acute administration of L-5-HTP may increase the escape of beta-endorphin secretion from suppression by dexamethasone in major, but not minor, depression.

Comparative study of rest technetium-99m sestamibi SPET and low-dose dobutamine stress echocardiography for the early assessment of myocardial viability after acute myocardial infarction: importance of the severity of the infarct-related stenosis.

Rest technetium-99m sestamibi single-photon emission tomography (SPET) has been shown to underestimate viability in some patients with chronic ischaemic myocardial dysfunction. The present study was designed to appraise the value of 99mTc-sestamibi as a viability tracer in patients with a recent myocardial infarction and to determine factors that might influence its accuracy in assessing infarct size. Therefore, rest 99mTc-sestamibi SPET, low-dose dobutamines stress echocardiography and quantitative coronary angiography were performed in 51 patients with a recent myocardial infarction. Perfusion activity and regional wall motion were scored semi-quantitatively using the same segmental division of the left ventricle. Assessment of 99mTc-sestamibi uptake as a marker of viability was performed by comparing a binary uptake score (viable=>50% vs necrotic =/=65%-100%) and particularly those with "late" reperfusion therapy (time delay >/=180 min). In patients without a severe infarct-related stenosis, 99mTc-sestamibi was able to accurately distinguish viable from necrotic segments. Thus, rest 99mTc-sestamibi scintigraphy early after acute myocardial infarction may underestimate residual viability within the infarct region, particularly in patients with low flow state coronary anatomy, as a result of a severe infarct-related stenosis and/or late reperfusion therapy.

Lower serum transcortin (CBG) in major depressed females: relationships with baseline and postdexamethasone cortisol values.

This study has been carried out to examine (i) transcortin or corticosteroid binding globulin (CBG), the major glucocorticoid transport protein, in major depressed versus minor depressed and normal subjects; and (ii) the relationships between CBG and basal and postdexamethasone cortisol or adrenocorticotropic hormone (ACTH) values. Serum CBG was significantly lower in major depressed than in minor depressed subjects and normal controls. The significant decrease in serum CBG was observed in major depressed women but not in major depressed men. In depressed subjects, there was a significant and negative relationship between serum CBG and severity of illness. There were significant positive relationships between serum CBG and basal 8:00 a.m. plasma cortisol in normal volunteers (r = 0.87, P < 10(-4)) and depressed subjects (r = 0.40, P = 0.0002). There was no significant relationship between serum CBG and 24-h urinary cortisol. In depressed patients, there was a positive relationship between serum CBG and postdexamethasone cortisol (r = 0.31, P = 0.003). It is concluded that, in depression, serum CBG levels should be taken into consideration for the interpretation of baseline and postdexamethasone plasma total cortisol levels.

Acute administration of buspirone increases the escape of hypothalamic-pituitary-adrenal-axis hormones from suppression by dexamethasone in depression.

Recently, our laboratory found a significant enhancing effect of L-5-hydroxy-tryptophan (L-5-HTP) on post-dexamethasone (DST) plasma adrenocorticotropic hormone (ACTH) and cortisol levels in major-but not in minor-depression. To further elucidate the effects of central serotonin (5-HT) activity on the negative feedback of glucocorticoids on hypothalamic-pituitary-adrenal (HPA)-axis function in depression, this study investigates the effects of buspirone, a 5-HT1A receptor agonist, on post-DST ACTH and cortisol levels in 75 depressed subjects. Plasma post-DST ACTH and cortisol concentrations were significantly increased by the acute administration of buspirone (30 mg PO) compared to placebo. There were no differences in buspirone-induced post-DST ACTH or cortisol responses between minor and major depression. There were significant correlations between post-DST ACTH and cortisol, and between post-DST-buspirone ACTH and cortisol. The buspirone-induced post-DST cortisol responses were significantly higher in depressed women than men. It is concluded that buspirone may augment ACTH and, consequently, cortisol escape from suppression by dexamethasone in major as well as in minor depression.