Fluorine-18-L-dihydroxyphenylalanine (18F-DOPA) positron emission tomography as a tool to localize an insulinoma or beta-cell hyperplasia in adult patients

CONTEXT AND OBJECTIVE: Fluorine-18-L-dihydroxyphenylalanine (18F-DOPA) positron emission tomography (PET) is a promising method in localizing neuroendocrine tumors. Recently, it has been shown to differentiate focal forms of congenital hyperinsulinism of infancy. The current study was set up to determine the potential of 18F-DOPA PET in identifying the insulin-secreting tumors or beta-cell hyperplasia of the pancreas in adults. PATIENTS AND METHODS: We prospectively studied 10 patients with confirmed hyperinsulinemic hypoglycemia and presumed insulin-secreting tumor using 18F-DOPA PET. Anatomical imaging was performed with computed tomography (CT) and magnetic resonance imaging (MRI). All patients were operated on, and histological verification was available in each case. Semiquantitative PET findings in the pancreas using standardized uptake values were compared to standardized uptake values of seven consecutive patients with nonpancreatic neuroendocrine tumors. RESULTS: By visual inspection of 18F-DOPA PET images, it was possible in nine of 10 patients to localize the pancreatic lesion, subsequently confirmed by histological analysis. 18F-DOPA uptake was enhanced in six of seven solid insulinomas and in the malignant insulinoma and its hepatic metastasis. Two patients with beta-cell hyperplasia showed increased focal uptake of 18F-DOPA in the affected areas. As compared to CT or MRI, 18F-DOPA PET was more sensitive in localizing diseased pancreatic tissue. CONCLUSION: 18F-DOPA PET was useful in most patients with insulinoma and negative CT, MRI, and ultrasound results. In agreement with previous findings in infants, preoperative 18F-DOPA imaging seems to be a method of choice for the detection of beta-cell hyperplasia in adults. It should be considered for the detection of insulinoma or beta-cell hyperplasia in patients with confirmed hyperinsulinemic hypoglycemias when other diagnostic work-up is negative.     

CT findings in acute myocarditis: 2 cases

Myocarditis is a serious and life-threatening illness, which can pose a significant diagnostic dilemma at presentation. We report 2 patients with clinical myocarditis who had distinctive findings at coronary computed tomography. Both patients demonstrated delayed myocardial enhancement with iodinated contrast. The morphologic features of the enhancement were similar to the myocardial enhancement with gadolinium contrast on magnetic resonance imaging recently described in patients with myocarditis, and different from the enhancement patterns seen in patients with myocardial infarction. These findings are not previously reported in the literature. As computed tomography is more widely available for use in the acute setting than magnetic resonance imaging, these findings may have significant clinical utility and warrant further investigation.     

ABO blood types: influence on infarct size, procedural characteristics and prognosis

Introduction

Patients with non-O blood groups have higher plasma von Willebrand factor (vWF) levels than those with type O. vWF mediates platelet adhesion, aggregation and thrombosis. These considerations likely explain the prior observations that non-O patients have higher rates of arterial and venous thromboembolic events. However, the effect of blood group status on size of MI, procedural findings and outcomes after PCI for MI have not been reported.

Methods

We analyzed 1198 patients who underwent percutaneous coronary intervention for acute myocardial infarction between 10/03 and 8/06, and who had ABO blood group status and clinical follow-up.

Results and conclusions

Patients with O blood type were slightly older (62 ± 13 vs. 60 ± 13years; p = 0.017) had a higher prevalence of hypercholesterolemia (67% vs. 58%; p = 0.002), and had a higher burden of atherosclerosis with more vascular disease (17% vs. 13%; p = 0.017) and higher prevalence of previous PCI (22% vs. 17%; p = 0.025). Non-O blood group patients had larger infarcts as measured by median peak troponin (33 vs. 24; p = 0.037), total CK (721 vs. 532; p = 0.012) and CK-MB (101 vs. 68; p = 0.010). At PCI, non-O patients had increased visible thrombus and reduced TIMI flow pre-procedure. However, there were no differences in procedural success, in-hospital blood transfusion or occurrence of MACE at 1year follow-up. Our data demonstrate that non-O compared to O blood groups patients have higher thrombus burden despite less extensive atherosclerosis. Nevertheless, outcomes at 1year were similar.     

Use of thrombolytic therapy in cerebral venous sinus thrombosis with ulcerative colitis

Cerebral venous thrombosis developing concurrently with active ulcerative colitis poses a therapeutic dilemma. We report the case of a 31-year-old woman who developed dural venous sinus thrombosis during the course of active ulcerative colitis in whom we accomplished clot lysis using intrasinus urokinase. The success of the procedure was assessed by improvement in the patient''s neurological condition and resolution of imaging features without any bleeding complications. We also reviewed literature on various modalities of treatment of sinus venous thrombosis in patients with ulcerative colitis and outcome.     

Solitary fibrous tumour of the oral cavity: clinicopathological and immunohistochemical characterization of three cases

Solitary fibrous tumour (SFT) is an uncommon mesenchymal neoplasm rarely located in the oral cavity. To characterize further oral SFT, we describe three new cases. Each tumour originated in the buccal mucosa of a middle-aged/elderly patient. Histological examination showed well-circumscribed tumours with densely cellular areas alternating with hypocellular areas in a variedly collagenous, vascular stroma. Mast cells were abundant. The spindle-shaped, neoplastic cells immunostained strongly for CD34 antigen and vimentin and weakly for bcl-2, but not for epithelial cell markers, alpha-smooth muscle actin, or neurofilament or S-100 proteins. Compatible with the virtual absence of mitoses and of marked nuclear atypia, the overall frequency of proliferating cells expressing Ki-67 was low. The expression of CD34 was useful in the differential diagnosis. The consistent location in the cheek and expansion of one tumour after local trauma does not preclude a traumatic element in the development of oral SFT.     

Blood pressure related to age: The India ABPM study

The present paper reports trends in office blood pressure (BP) measurement (OBPM) and ambulatory blood pressure measurement (ABPM) with age in a large multi‐center Indian all comers’ population visiting primary care physicians. ABPM and OBPM data from 27 472 subjects (aged 51 ± 14 years, males 68.2%, treated 45.5%) were analyzed and compared. Individual differences between OBPM and ABPM patterns were compared for patients according to 10‐year age categories. Results showed that systolic (S) BP values started to increase with age from the age of 40, BP variability (SD) increased from the age of 30 years. Diastolic (D) BP values started to decrease from the age of 50 years. Mean OBPM values were higher than daytime ABPM values (all P < .001) in all age‐groups. The prevalence of white coat hypertension (WCH) and masked hypertension (MH) was based on OBPM and daytime, 24‐hour, and nighttime average BPs together. WCH decreased with age from 15.1% and 12.4% in treated and untreated subjects at the youngest age to 7.2% and 6.9% in the oldest age, respectively. MH prevalence was higher for untreated than for treated subjects but remained similar for all age‐groups (range of 18.6%‐21.3%). The prevalence of reverse dippers increased with age from the youngest to oldest group with 7.3%‐34.2% (P < .001 for trend). Dippers prevalence decreased from 42.5% to 17.9% from the youngest to oldest age‐groups, respectively (P < .001 for trend). These findings confirm that BP patterns show clear differences in trends with age, particularly regarding nighttime BP.     

A randomized, double-blind, parallel-group, comparative safety, and efficacy trial of oral co-artemether versus oral chloroquine in the treatment of acute uncomplicated Plasmodium falciparum malaria in adults in India

In India, treatment of acute, uncomplicated Plasmodium falciparum malaria is becoming increasingly difficult due to resistance to chloroquine, thus there is a need for new antimalarial drugs. CGP 56697 (co-artemether), a new drug, is a combination of artemether and lumefantrine in a single oral formulation (one tablet = 20 mg of artemether plus 120 mg of lumefantrine). In a double-blind study, 179 patients with acute uncomplicated P. falciparum malaria were randomly assigned to receive either CGP (n = 89) given as a short course of 4 x 4 tablets over a 48-hr period or chloroquine (n = 90) given as four tablets (one tablet = 150 mg of chloroquine base) initially, followed by two tablets each at 6-8, 24, and 48 hr. Due to a death in the chloroquine group and a decrease in the chloroquine cure rate to < 50% (based on the blinded overall cure rate at that time), recruitment was terminated prematurely. CGP 56697 showed a superior 28-day cure rate (95.4% versus 19.7%; P < 0.001), time to parasite clearance (median = 36 versus 60 hr; P < 0.001), and resolution of fever (median = 18 versus 27 hr; P = 0.0456). This drug provides a safe, effective, and rapid therapy for the treatment of acute uncomplicated P. falciparum malaria.     

Angiostatin selectively inhibits signaling by hepatocyte growth factor in endothelial and smooth muscle cells

Angiostatin, an inhibitor of angiogenesis, contains 3 to 4 kringle domains that are derived from proteolytic cleavage of plasminogen. The antiangiogenic effects of angiostatin occur, in part, from its inhibition of endothelial cell surface adenosine triphosphate synthase, integrin functions, and pericellular proteolysis. Angiostatin has structural similarities to hepatocyte growth factor (HGF; "scatter factor"), a promoter of angiogenesis, that induces proliferation and migration of both endothelial and smooth muscle cells via its cell surface receptor, c-met. We hypothesized that angiostatin might block HGF-induced signaling in endothelial and smooth muscle cells. Angiostatin inhibited HGF-induced phosphorylation of c-met, Akt, and ERK1/2. Angiostatin also significantly inhibited proliferation of human umbilical vein endothelial cells (HUVECs) induced by HGF. In contrast, angiostatin did not inhibit vascular endothelial growth factor (VEGF)-or basic fibroblast growth factor (bFGF)-induced signaling events or HUVEC proliferation. Angiostatin bound to immobilized truncated c-met produced by A431 cells and could be immunoprecipitated as a complex with soluble c-met. HGF inhibited the binding of (125)I-angiostatin to HUVECs. Soluble c-met, produced by several tumor cell lines, could inhibit the antiangiogenic effect of angiostatin. The disruption of HGF/c-met signaling is a novel mechanism for the antiangiogenic effect of angiostatin.