Fuat Dede

Orlistat accelerates gastric emptying and attenuates GIP release in healthy subjects

Orlistat, an inhibitor of digestive lipases, is widely used for the treatment of obesity. Previous reports on the effect of orally ingested orlistat together with a meal on gastric emptying and secretion of gut peptides that modulate postprandial responses are controversial. We investigated the effect of ingested orlistat on gastric emptying and plasma responses of gut peptides in response to a solid mixed meal with a moderate energy load. In healthy subjects, gastric emptying was determined using scintigraphy and studies were performed without and with 120 mg of orlistat in pellet form in random order. Orlistat shortened t lag and t half and decreased the area under the gastric emptying curve. Orlistat significantly attenuated the secretion of glucose-dependent insulinotropic polypeptide (GIP) but did not alter the plasma responses of cholecystokinin (CCK), glucagon-like peptide-1 (GLP-1), pancreatic polypeptide (PP), and insulin. There was no peptide YY (PYY) response. Area under the curve of gastric emptying was positively correlated with integrated secretion of GIP (r=0.786) in orlistat and was negatively correlated with integrated plasma response of GLP-1 (r=-0.75) in control experiments, implying that inhibition of fat absorption modifies determinants of gastric emptying of a meal. Orlistat administered similar to its use in obesity treatment accelerates gastric emptying of a solid mixed meal with a moderate energy load and profoundly attenuates release of GIP without appreciably altering plasma responses of CCK, GLP-1, and PP. Since GIP is being implemented in the development of obesity, its role in weight control attained by orlistat awaits further investigation.

Tc-99m sestamibi gated SPECT in patients with left bundle branch block.

Purpose The purpose of this study was to assess the diagnostic role of a Tc-99m sestamibi gated SPECT technique in patients with left bundle branch block (LBBB) without known coronary artery disease. Materials and Methods Twenty consecutive patients with constant complete LBBB were included. A same-day rest-stress protocol was used, and dipyridamole stress (14 patients) or treadmill exercise (6 patients) was applied. Electrocardiograph (ECG)-gated SPECT images were acquired 15 minutes after the administration of 0.31 mCi/kg Tc-99m sestamibi at peak stress. Regional myocardial perfusion was analyzed in relation to the cardiac cycle. Results Eleven of 14 patients who underwent a dipyridamole stress test had hypoactivity in the left anterior descending (LAD) artery territory in the ungated (summed) stress–rest images (abnormality ratio, 78%). On the ungated images, the abnormality was completely reversible in one patient (9%), partially reversible in five patients (46%), irreversible in two patients (18%), and reverse perfusion was identified in three patients (27%). Abnormality ratios of end-systolic and end-diastolic data were 93% and 29%, respectively. Conversely, the ungated rest-stress and end-systolic images of all the patients who performed treadmill exercise were abnormal despite the presence of normal or nearly normal end-diastolic myocardial perfusion. The angiographic findings correlated best with those of end-diastolic images. In 13 patients without coronary artery disease, normal or nearly normal regional perfusion was observed on end-diastole, but four patients with abnormal end-diastolic perfusion, which involved the LAD territory in all but one, had substantial coronary artery disease. The number of the involved segments was similar on the end-systolic and ungated data. Most of these artifactual defects were localized to the anteroseptal, septal, and inferoseptal segments. Conclusions These preliminary data indicate that end-diastolic images can significantly reduce artifactual defects in patients with LBBB. The resolution of an LBBB pattern on end-diastolic data would significantly improve the diagnostic role of myocardial perfusion studies in these patients.

Patients with Takayasu's arteritis having persistent acute-phase response usually have an increased major vessel uptake by 18F-FDG-PET/CT

Abstract Objectives. Although not uniformly accepted, an increased uptake by 18F-fluorodeoxyglucose (FDG)-positron emission tomography (PET)/computed tomography (CT) in large vessels is accepted to be a sign of active disease in Takayasus arteritis (TAK). We aimed to investigate the value of 18F-FDG-PET/CT for clinical assessment in a subset of TAK patients having a persistent acute-phase response (APR) without any signs or symptoms of clinical disease activity. Method. We studied 14 patients (mean age: 38.6 ± 13.9 years, Female/Male: 11/3, and disease duration: 5.7 ± 5 years). Patients were clinically inactive (according to the definition of activity by Kerr et al.), while categorized as having “persistent” disease activity by physicians global assessment due only to APR. 18F-FDG uptake was graded using a four-point scale from grade 0 (no uptake present) to grade 3 (high grade: uptake higher than that of liver). Any uptake in major vessels with a grade ≥ 2 was accepted to be “active.” Results. Mean erythrocyte sedimentation rate was 50.8 ± 13.2 mm/hour and mean C-reactive protein level was 28.5 ± 22.1 mg/L. Active vasculitic lesions were observed by 18F-FDG-PET/CT in 9 of 14 (64.3%) patients. The median number of active vascular lesions was 2 (range: 1–5). A step-up treatment change was decided in 8 patients according to 18F-FDG-PET/CT results. Conclusion. We observed increased 18F-FDG uptake in the majority of TAK patients with an increased APR, but clinically silent disease. 18F-FDG-PET/CT showed the presence and localization of active inflammation in the aorta and its branches. Although specificity for observed lesions is not clear, 18F-FDG-PET/CT imaging may influence physicians assessment of clinical activity and treatment choices in TAK.

Pitfalls in the diagnosis of thyroid dysgenesis by thyroid ultrasonography and scintigraphy

OBJECTIVES We aimed to investigate the reliability of thyroid ultrasonography (US) and scintigraphy in determining the type of thyroid dysgenesis (TD). METHODS The study included 82 children (8.0±5.6 years) with a diagnosis of TD by thyroid scintigraphy with (99m)Tc and/or US. The patients were re-evaluated 6.0±5.1 years after the diagnosis. Thyroid US was performed in all cases, regardless of the previous US imaging. Scintigraphy images performed at the time of diagnoses (n=60) were re-evaluated during the study. Those who had no scintigraphy at the time of diagnosis (n=22) or had discordant findings with US (n=6) underwent a new scintigraphy. RESULTS Scintigraphies revealed no uptake in 37, ectopia in 35, and hypoplasia in 10 cases. The sensitivity vs specificity for US to detect athyreosis, ectopia, and hypoplasia at the time of initial diagnoses was 90.5 vs 47.8, 10 vs 100, and 100 vs 80.4% respectively. The sensitivity vs specificity for scintigraphy at the time of initial diagnoses was 96.2 vs 100, 92 vs 97.1, and 100 vs 96%, respectively, for each diagnosis. Re-scintigraphy at the time of the study led to a change in the initial diagnosis of 3/6 cases. Repeated US showed disappearance of previously reported hypoplastic thyroid tissues in eight patients. CONCLUSION US alone could not differentiate ectopia and athyreosis, whereas scintigraphy alone is also prone to mistakes in newborns and young ages. Dual thyroid imaging is important for precise structural definition of TD.

Comparison of WHO, RECIST 1.1, EORTC, and PERCIST criteria in the evaluation of treatment response in malignant solid tumors.

AimTo compare response assessment according to the WHO, RECIST 1.1, EORTC, and PERCIST criteria in patients diagnosed with malignant solid tumors and who had received cytotoxic chemotherapy to establish the strength of agreement between each criterion. Materials and methodsSixty patients with malignant solid tumors were included in this retrospective study. The baseline and the sequential follow-up fluorine-18-fluorodeoxyglucose PET/computed tomography (CT) of each patient were evaluated according to the WHO, RECIST 1.1, EORTC, and PERCIST criteria. PET/CT images were used for both metabolic and anatomic evaluation. The concurrent diagnostic CT and MRI images (performed within 1 week of PET/CT) were also utilized when needed. The results were compared using the &kgr;-statistics. ResultsThe response and progression rates according to the WHO criteria were 37 and 38%, respectively. The same ratios were also found for RECIST 1.1 (&kgr;=1). The response and progression rates according to the EORTC criteria were 47 and 40%, respectively. When PERCIST criteria were used, one patient with progressive disease was upgraded to stable disease (&kgr;=0.976). As we found the same results with WHO and RECIST 1.1 criteria, we used WHO criteria to compare the anatomic and metabolic criteria. When we compared the WHO and EORTC criteria, there was an agreement in 80% of the patients (&kgr;=0.711). With WHO and PERCIST criteria, there was an agreement in 81.6% of the patients (&kgr;=0.736). ConclusionSignificant agreement was detected when the WHO, RECIST 1.1, EORTC, and PERCIST criteria were compared both within as well as between each other.

Aspiration of Nasal Secretions Into the Lungs in Patients With Acute Sinonasal Infections

Objectives: To compare the amounts of nasal secretions aspirated into the lower airway by patients with acute sinonasal infection with that aspirated by healthy adults during sleep.

Scrotal peritoneal mesothelioma on PET/CT.

Although malignant mesothelioma originating from the tunica vaginalis has been reported in the literature, direct invasion of malignant peritoneal mesothelioma to the scrotal cavity has not been described yet. Herein, we presented a diffuse malignant peritoneal mesothelioma extending inferiorly to the scrotum via inguinal canal detected on FDG PET/CT.

FDG PET/CT appearance of portal vein tumor thrombus in the gastric primitive neuroectodermal tumor: uncommon primary tumor site with rare finding.

Gastric primitive neuroectodermal tumor (PNET) is a very rare tumor. There are only a few case reports in the literature. Although cases with FDG uptake in the portal venous tumor thrombus (PVTT) in different primary malignancies have been evaluated before, the coexistence of PNET and PVTT has not been reported yet. Herein, we report the case of a gastric PNET with PVTT, which resolved after 3 cycles of polychemotherapy except for a residual tumor focus in the gastric corpus.

Multiparametric analysis of preoperative lymphatic mapping with the use of combined deep plus superficial radiotracer injection technique in early breast cancer.

ObjectivesAccording to literature, combined tracer injection techniques seem to be the more powerful choice to eliminate technical and patient-related limitations. In this study, we analysed the quantitative performance parameters of combined deep plus superficial radiotracer injection and their correlation with a set of clinical, pathological and technical factors. MethodsOne hundred and sixteen women who underwent preoperative sentinel lymph node (SLN) mapping were studied prospectively. All patients received the simultaneous deep and superficial injection of 99mTc-nanocolloid. Mapping success rate, mean number of SLNs per patient and radiotracer uptake of SLNs were determined. The possible effects of age, tumour stage, laterality and location, type and time of previous biopsy, and SLN status on the quantitative parameters were analysed. ResultsAxillary SLNs were visualized in all cases. Mean number of axillary SLNs was 2.15 and advanced age (>50) significantly decreased the number of SLNs. Radiotracer uptake of SLNs was also significantly decreased by advanced age and a shorter time interval between biopsy and mapping (<10 days). Extra-axillary SLN visualization rates for medial, lateral and periareolar injection sites were 32%, 16% and 8%. Although SLN gamma probe counts were significantly higher in the single-day protocol, the 2-day protocol gave better contrast values which was also an important parameter in lesion detection. ConclusionThe combined radiotracer injection technique successfully demonstrated axillary and extra-axillary SLNs. Advanced age and previous biopsy time can lower the accuracy and reliability of SLN biopsy. Although periareolar injection gave the best results for the axilla, it was still insensitive for extra-axillary SLNs in spite of deep injection.

The clinical utility of 99mTc-HMPAO SPECT in Fahr’s disease

Fahr’s disease is a rare neurodegenerative syndrome, characterized by massive symmetrical intracerebral calcifications of the basal ganglia, dentate nuclei of the cerebellum, and the adjacent parenchyma. Computerized tomography (CT) is considerably more sensitive to detect these intracranial calcifications than other imaging modalities. The clinical, CT scan, and 99mTc-D,L-hexamethylpropylene amine oxime (99mTc-HMPAO) brain perfusion single-photon emission computerized tomography (SPECT) findings in a 42-year-old woman with Fahr’s disease are reported, and the clinical utility of 99mTc-HMPAO SPECT findings in Fahr’s disease is discussed in this article. In conclusion, 99mTc-HMPAO brain perfusion SPECT seems to be useful in the clinical approach to Fahr’s disease, and may provide more specific and clinically relevant information when compared with anatomical imaging.