Factors predicting tracer uptake in somatostatin receptor and MIBG scintigraphy of metastatic gastroenteropancreatic neuroendocrine tumors.

Radiolabeled octreotide analogs (Oct) and metaiodobenzylguanidine (MIBG) offer 2 different approaches for imaging and targeting metastatic gastroenteropancreatic neuroendocrine tumors (GEP-NET). Despite successful establishment of the revised World Health Organization (WHO) classification, which distinguishes between low- and high-grade malignant GEP-NET, there is a lack of scintigraphic studies comparing uptake behavior on the basis of this categorization. This study aims to define predisposing factors of tracer uptake for both imaging principles implementing the updated tumor criteria of the current WHO classification. METHODS: Fifty-seven consecutive patients with histologically confirmed metastatic GEP-NET evaluated with both 111In-pentetreotide and 123I/131I-MIBG scintigraphy were included in this study. Intensity of tracer uptake was graded according to the different metastatic regions. Patients were classified as overall positive when avid uptake in the clinically relevant tumor lesions was present. Correlation was tested between the proportion of positive patients and tumor origin, function, and malignancy. RESULTS: Overall, 52 patients (91.2%) were Oct positive and 28 patients (49.1%) were MIBG positive. The proportion of tracer-positive patients was significantly higher (P < 0.05) in low-grade malignant tumors for both tracers and in functioning as well as in gastroenteral NET for MIBG. Five patients were negative for both tracers. None of the Oct-negative patients proved to be MIBG positive. CONCLUSION: Oct affinity is observed with high frequency throughout the subgroups of metastatic GEP-NET, whereas corresponding MIBG uptake is overall less prevalent and more group dependent. Tumor differentiation significantly impacts both Oct and MIBG uptake, whereas functionality predisposes only for MIBG accumulation. Though clearly inferior to Oct-based radioimaging in most GEP-NET, MIBG achieves a remarkable rate of radioligand accumulation in functioning midgut enterochromaffin cell metastases (>80% of patients positive). These results may have implications for patient management and potentially for selection and performance of targeted therapy.     

Relationship of the blood pressure's level and skinfold thickness]

OBJECTIVE: Hypertension is an important problem of the public health. Insufficient education of the people along with insufficient physical examination also plays a role in the poor success of the diagnosis and treatment of the hypertension. We investigated whether the skinfold thickness has an importance in the prediction of blood pressure or not. METHODS: In Aydin City area 110 women and 100 men selected by randomized sampling method were included into our study. Body mass index, blood pressure and skinfold thickness were measured according to the international guidelines. RESULTS: There was a moderate correlation between the skinfold and body mass index (r= 0.494, p=0.000) and there was a mild correlation between the body mass index and systolic and diastolic blood pressures (r=0.225, p=0.000 and r=0.300, p=0.000, respectively). There was no correlation between the skinfold thickness and systolic and diastolic blood pressures (r=0.058, p=0.400 and r=0.090, p=0.194, respectively). CONCLUSION: It is concluded that body mass index, not skinfold thickness, can be used for the prediction of the blood pressure. Some other factors independent from the body mass index might be the determinants of the skinfold thickness.     

INAUGURAL ARTICLE by a Recently Elected Academy Member:From oligonucleotide shapes to genomic SELEX: Novel biological regulatory loops

The SELEX method and oligonucleotide combinatorial chemistry discovery process yields high-affinity/high-specificity ligands for virtually any molecular target. Typically, the enormous starting libraries used in the SELEX process contain 10¹⁴–10¹⁵ sequences. We now ask if the smaller sequences, complexity of extant organisms, and evolutionary history provide useful interactions between oligonucleotides and at least some unexpected targets. That is, do organisms contain a robust “linkage map” between their oligonucleotides and proteins and/or small molecules that enriches life?     

Comparison of completion thyroidectomy and primary surgery for differentiated thyroid carcinoma.

AIM: The objective of this study is to analyze the complication rates after the completion thyroidectomy and compare them with primary total thyroidectomy. METHODS: The outcomes of patients with differentiated thyroid carcinoma who were operated over a period of eight years were evaluated. One hundred and forty-one patients underwent completion thyroidectomy and 92 patients had primary surgery. RESULTS: The two groups were comparable in respect of clinical variables. Residual tumor was found in 66 of 141 patients (46.8%) in completion thyroidectomy group. The rate of the two most important complications, permanent recurrent laryngeal nerve palsy and permanent hypoparathyroidism were 3.5 and 4.2%, in completion thyroidectomy group, and 3.3 and 4.3%, in primary total thyroidectomy group. The complication rates were not significantly different between groups. CONCLUSION: In conclusion, completion thyroidectomy can be done safely in a specialized center with acceptable morbidity.     

Evaluation of pH and calcium ion release of Acroseal sealer in comparison with Apexit and Sealapex sealers.

OBJECTIVE: This is an in vitro assessment of pH level and calcium ion release exhibited by 3 calcium hydroxide-based root canal sealers-Sealapex, Apexit, and Acroseal. STUDY DESIGN: The materials were prepared according to the manufacturers' instructions and placed in 1 cm long and 4 mm diameter tubes. The tubes were then immersed in a glass flask containing 10 mL bidistilled water (n = 15), which was sealed and stored at 37 degrees C before the materials had set. The control group contained bidistilled water with empty tubes (n = 12). At predetermined time intervals (24 h, 96 h, and 7, 15, and 28 days) the pH of the bidistilled water was tested with a pH meter and for released calcium by using spectrophotometry. The data were statistically analyzed using 1-way analysis of variance for the comparison of the materials at each time point. If the difference was significant, individual comparisons were performed by Tukey multiple comparisons test (alpha = .05). RESULTS: Sealapex produced higher pH and released significantly higher calcium amounts than the other 2 sealers at all periods (P < .05). Apexit showed higher calcium release than Acroseal at the end of 15 days (P < .05). There was no significant difference in the pH between Apexit and Acroseal (P > .05). CONCLUSION: The new Acroseal sealer presented the least calcium ion release and pH than Sealapex and less calcium ion release than Apexit sealer.     

Arginine selective biosensor based on arginase-urease immobilized in gelatin

Arginase and urease enzymes were immobilized on the surface of pH electrode by using gelatin membrane which is then cross-linked with glutaraldehyde. Sensor response was maximum when 2.5 mM, Tris-HCl buffer (pH 8.5) was used at 25 degrees C. The biosensor response depends linearly on arginine concentration between 0.025-0.310 mM with response time 10 min. Furthermore, application of the system for the arginine detection in serum samples was also tested.     

Dopamine in the orbitofrontal cortex regulates operant responding under a progressive ratio of reinforcement in rats

Prefrontocortical dopamine (DA) plays an essential role in the regulation of cognitive functions and behavior. The orbitofrontal cortex (OFC) receives a dopaminergic projection from the ventral tegmental area and is particularly important for goal-directed appetitive behaviors and for the neural representation of reward value. We here examined the effects of DA receptor blockers locally infused into the OFC, on instrumental behavior under a progressive schedule of reinforcement. After continuous reinforcement training (lever pressing for casein pellets) rats received bilateral intra-OFC-infusions of the DA D1-receptor antagonist SCH23390 (3 μg/0.5 μl), the DA D2-receptor antagonist sulpiride (3 μg/0.5 μl), or phosphate buffered saline through chronically indwelling cannulae. Immediately after infusion they were tested under a time-constrained progressive ratio schedule of reinforcement (3, 6, 9, 12, … lever presses for 1 casein pellet within 180 s). Both SCH23390 and sulpiride led to a significant reduction of the break point (cessation to respond to the increasing criterion of instrumental effort) compared to vehicle infusions. A food preference test revealed no drug effects on the amount of consumed pellets and on the preference of casein pellets over laboratory chow. Leftward shifts of the break point in progressive ratio tasks indicate a disturbance of the mechanisms that translate motivation into appetitive behavior under conditions of increasing instrumental effort. Therefore, our data indicate that orbitofrontal dopamine is necessary for reward-related instrumental behavior.     

Prevalence of hepatitis B virus infection in pregnant Turkish women and their families

A total of 5,366 pregnant Turkish women were screened for hepatitis B surface antigen (HBsAg) and 225 (4.2%) of them were found to be positive. Hepatitis B e antigen (HBeAg) was detected in 6.2% of HBsAg-positive pregnant women. The overall prevalence of HBsAg and antibody to HBsAg (anti-HBs) among the spouses, previous children, mothers and first degree relatives of the HBsAg-positive pregnant women was 56%, 49%, 79% and 74% respectively. The prevalence of HBsAg is thus high in pregnant Turkish women with familial clustering of hepatitis B virus infection.