Dielectric Detection of Single Nanoparticles Using a Microwave Resonator Integrated with a Nanopore.

The characterization of individual nanoparticles in a liquid constitutes a critical challenge for the environmental, material, and biological sciences. To detect nanoparticles, electronic approaches are especially desirable owing to their compactness and lower costs. While electronic detection in the form of resistive-pulse sensing has enabled the acquisition of geometric properties of various analytes, impedimetric measurements to obtain dielectric signatures of nanoparticles have scarcely been reported. To explore this orthogonal sensing modality, we developed an impedimetric sensor based on a microwave resonator with a nanoscale sensing gap surrounding a nanopore built on a 220 nm silicon nitride membrane. The microwave resonator has a coplanar waveguide configuration with a resonance frequency of approximately 6.6 GHz. The approach of single nanoparticles near the sensing region and their translocation through the nanopores induced sudden changes in the impedance of the structure. The impedance changes, in turn, were picked up by the phase response of the microwave resonator. We worked with 100 and 50 nm polystyrene nanoparticles to observe single-particle events. Our current implementation was limited by the nonuniform electric field at the sensing region. This work provides a complementary sensing modality for nanoparticle characterization, where the dielectric response, rather than ionic current, determines the signal.

Is adipose tissue metabolic activity a predictor of pathological responses to neoadjuvant treatment in breast cancer.

INTRODUCTION AND OBJECTIVE: Prediction of the pathologic response to neoadjuvant chemotherapy (NAC) in patients with locally advanced breast cancer is essential for optimal treatment strategy. The current approach of adjuvant or neoadjuvant treatment is based on the molecular subtype. Obesity may have affected chemotherapy response. This study aims to evaluate the relationship between metabolic activity of adipose tissue (AT) and pathological responses to NAC. And to define the association with body mass index (BMI) and metabolic parameters of standardized uptake value (SUV) of adipose tissue measured by positron emission computed tomography (PET/CT). MATERIAL AND METHODS: One-hundred and sixteen consecutive patients with stage II and III breast cancer who underwent PET/CT before receiving NAC, were evaluated in the study. Metabolic parameters of visceral adipose tissue (VAT-SUV), subcutaneous adipose tissue (SAT-SUV), and calculated SUV of visceral-to-subcutaneous ratio (V/S-ratio) were regarded. The relationship between SUV of AT and pathologic response was evaluated from medical records retrospectively. RESULTS: Univariate-analysis revealed that good pathological response was significantly associated with clinical stage (P<.001), HER-2 positivity (P<.001), VAT-SUV (P=.037), VAT-density (P=.043) and V/S-ratio (P=.003). In multivariate-analysis clinical stage, HER-2 positivity and V/S-ratio were found to have statistically effect on pathological response. VAT-volume (P<.001), VAT-SUV (P=.016), SAT-volume (P<.001) and SAT-SUV (P<.001) has positive correlation with BMI value. On the other hand, V/S-ratio (P=.039) and SAT-density (P=.003) has negative correlation with BMI. CONCLUSION: Metabolic activity of AT is associated with BMI and effected chemotherapy responses. LowV/S ratio was associated with high BMI and poor pathological response to NAC. V/S ratio may be a useful marker for the prediction of NAC responses.

Effects of Rapid Maxillary Expansion on the Temporomandibular Joint: A Bone Scintigraphy Study.

OBJECTIVE: The purpose of this study is to assess the effects of rapid maxillary expansion on metabolic activity in the temporomandibular joints of young adult patients using scintigraphy. METHODS: The images belonging to temporomandibular joints were obtained from the retrospective scintigraphic records taken from 17 adult females (16.1 and 18.8 years of age and the mean age was 17.3±0.86 years) who had non-functional bilateral posterior crossbite, deep palatal vault and dental crowding, and had been treated with rapid maxillary expansion. Bone scintigraphy images were collected at three-time intervals: at the beginning of treatment (T1), during the opening of the mid palatal suture (T2), and at the end of screw activation (T3). Alteration in bone activity in the temporomandibular joint regions were evaluated in sagittal and transaxial slices. To determine the differences between the intervals, repeated analysis of variance and Bonferroni multiple comparison tests were applied. RESULTS: In the right and left temporomandibular joint regions, significantly increased metabolic activity was exhibited between T1-T2 (p<0.001). At the time of opening the maxillary mid-palatal suture, the metabolic activity increased approximately 60% compared to the initial status. At the end of the active expansion period (T3), the change in metabolic activity was approximately 20% reduced compared to T2. CONCLUSION: Metabolic activity intensification occurs in the regions of interest in the temporomandibular joint during rapid maxillary expansion. After mid-palatal suture opening, activity noticeably decreased (T2-T3). This decrease in bone activity suggests that the temporomandibular joint complex adapts to rapid maxillary expansion forces.

Left ventricular remodeling assessment in patients with anterior acute myocardial infarction treated with successful primary percutaneous coronary intervention: an observational study.

OBJECTIVE: We aimed to analyze the left ventricular (LV) remodeling in patients treated with coronary intervention (PCI) in the acute phase of anterior myocardial infarction (MI) and to analyze the relationship between LV functional remodeling and residual viability in the infarct zone detected by thallium-201 (Tl-201) imaging and echocardiography. METHODS: We designed an observational prospective cohort study including 30 patients (26 men, 4 women, mean age; 52±12 years old) with acute anterior MI. Echocardiography and Tl-201 imaging were performed in all patients three days and two months after PCI and left ventricular end-systolic volume (ESV), left ventricular end-diastolic volume (EDV), ejection fraction (EF) and summed redistribution score (SRS) were calculated. Paired samples t- test or Wilcoxon rank sign test for comparing continuous variables in dependent groups, Pearson correlation for testing relationship between continuous variables were used. RESULTS: Left ventricular function baseline values just after PCI and two months after PCI obtained by echocardiography and scintigraphy were statistically significant. Among patients 76.7% had an EF ≥0.50 after the event. EDV and ESV values are significantly low when compared to values two months before. There was not any marked change in SRS in five patients. Polar maps were correlated with heart rate (r=0.438; p=0.023), peak creatine kinase MB (r=0.440; p=0.015) and troponin (r=0.471; p=0.009) during acute MI. CONCLUSION: Significant recovery in EDV, ESV and SRS values, and increase in EF two months after the infarction shows us substantial part of the remodeling process is completed in two months and Tl-201 imaging is extremely effective in determining of salvaged myocardium.

Thyroid functions after contrast agent administration for coronary angiography: a prospective observational study in euthyroid patients.

OBJECTIVE: This study aims to investigate long-term effects of iodinated radiographic contrast media used for coronary angiography (CAG) on the thyroid function in euthyroid patients. METHODS: In a prospective observational cohort study, nonionic iodinated contrast material was electively used in 101 patients for coronary angiography. The patients were recruited without age restrictions and, at baseline, all had normal levels of free triiodothyronine (FT3), free thyroxine (FT4) and thyrotropin (TSH). The morphology of the thyroid was evaluated by thyroid ultrasonography (USG). Four and eight weeks after CAG, serum TSH, FT3 and FT4 levels were assessed. RESULTS: Compared to a mean baseline level of 1.49 (25%-75%, range 13-2.21), follow-up TSH levels decreased significantly to 1.45 (25%-75%, range 1.98-0.92, p=0.017) and 1.40 (25%-75%, range 1.89-0.87, p=0.003) at 4 weeks and 8 weeks, respectively (p=0.008). No significant diffe-rence was observed in TSH levels between the 4th and 8th weeks (p=0.833). CONCLUSION: Iodinated radiographic contrast agents may cause subclinical hyperthyroidism in euthyroid patients undergoing CAG.

Detection of orchitis and sacroiliitis due to brucellosis by 99mTc polyclonal human immunoglobulin scintigraphy.

Here, we report 1 case of Brucella orchitis detected by 99mTc human immunoglobulin scintigraphy and confirmed by testicular ultrasound. A 29-year-old farmer was admitted to our hospital with fever, fatigue, arthralgia, and painful scrotal swelling that had appeared 12 days before admission. Clinically, right sacroiliitis was recorded through the Fabere test Unilateral sacroiliitis and orchitis were detected by 99mTc human immunoglobulin scintigraphy. Hypoechoic left testicular lesions and swelling of the concurrent epididymis were seen on a testicular ultrasound examination. Wright agglutination test and blood specimen culture for Brucella species were positive.

Scintigraphic evaluation of acute pancreatitis patients with 99mTc-HMPAO-labelled leukocytes.

OBJECTIVE: To demonstrate the localization of leukocytes in the pancreas during acute pancreatitis and to evaluate the potential use of 99mTc-HMPAO-labelled leukocytes in the diagnostic assessment of patients with acute pancreatitis. METHODS: The study was performed with 20 patients (11 females, nine males; ranging in age from 26 to 86 years, mean 55 years). Labelled leukocyte scintigraphy using planar imaging was performed on all patients, seven of whom were also examined by single photon emission computed tomography (SPECT). According to Ranson criteria, 10 patients had mild pancreatitis (group A), six had severe pancreatitis (group B) and four had necrotic pancreatitis (group C). Twelve patients had biliary pancreatitis and the other eight patients had no obvious cause. RESULTS: All patients of group C, four of group B, two of group A had a positive leukocyte scan. The positive leukocyte scintigraphy value for the detection of a lethal course of acute pancreatitis was 100%; of a severe course, 66.7%; and of a mild course, 20%. These findings are statistically significant (P=0.005 in chi-squared tests result). The results of leukocyte scintigraphy compared with those of CT were also statistically significant (P=0.001 in chi-squared tests). All the patients diagnosed with pancreatic necrosis by CT had a positive leukocyte scan, but only three of 13 patients without pancreatic necrosis that could be detected by computed tomography had a positive leukocyte scan. CONCLUSIONS: There was a significant correlation between the severity of the disease and leukocyte infiltration. Considering these results, we believe that leukocyte infiltration in acute pancreatitis can be demonstrated rapidly and accurately and by noninvasive 99mTc-HMPAO labelled leukocyte scintigraphy.

Nonsurgical rapid maxillary expansion effects on craniofacial structures in young adult females. A bone scintigraphy study.

OBJECTIVE: To evaluate the skeletal effects of nonsurgical rapid maxillary expansion (RME) on craniofacial structures with bone scintigraphy in young adult female subjects. MATERIALS AND METHODS: The material of the present study consists of scintigraphic records taken from 17 early adult females treated with RME. All patients had a bilateral posterior crossbite, transverse maxillary deficiency, deep palatal vault, and dental crowding at the beginning of the treatment. The age range of the patients was 16.1 to 18.8 years, and the mean age was 17.3 +/- 0.86 years. Bone scintigraphy records were obtained before RME (T1), during the splitting of the midpalatal suture (T2), and after the end of active widening period (T3). Repeated measure analysis of variance was used to assess the differences between the periods. In addition, Bonferroni multiple comparison tests were applied to the measurements at which F values were found to be statistically significant. RESULTS: According to the statistical analysis, significant activity changes were found in all regions studied and in all slices. The metabolic activity in all regions showed significant increases up to the separation of the midpalatal suture (T1-T2), whereas the metabolic activity exhibited a remarkable decrease (T2-T3) after the opening of the midpalatal suture. CONCLUSIONS: Scintigraphic records revealed an increase in the regions of interest scores during RME in all regions and all slices. Therefore, it can be speculated that RME has had not only dental effects but also skeletal effects on young adult patients.

99mTc-labelled red blood cell single-photon emission computed tomography for the diagnosis and follow-up of juvenile nasopharyngeal angiofibroma.

AIM: To confirm the usefulness of blood pool scintigraphy with Tc-labelled red blood cells ((99m)Tc-RBCs) in the diagnosis and follow-up of juvenile nasopharyngeal angiofibroma. METHODS: A prospective study design was used. (99m)Tc-RBCs were prepared by a modified in-vivo method. After the rapid intravenous injection of 370-740 MBq of (99m)Tc-RBCs, dynamic imaging of 1-min duration was performed. After dynamic imaging, static acquisitions at 5 min (second phase: blood pool phase) and 2 h (third phase: static image) were obtained. In addition, single-photon emission computed tomography (SPECT) imaging was performed at 2 h. SPECT images were obtained using a rotating gamma camera (GE-Starcam 4000 XR/T). RESULTS: All patients showed no activity in the first phase and mild activity in the second phase (blood pool phase). All patients with juvenile nasopharyngeal angiofibroma showed a prominent increased activity in the third phase and in SPECT images. CONCLUSIONS: This study shows that blood pool scintigraphy with (99m)Tc-RBC SPECT is very accurate, easy to perform and a suitable alternative to pre-operative and post-operative imaging techniques, including computed tomography scan, magnetic resonance imaging (MRI) and MRI angiography, for the detection of juvenile nasopharyngeal angiofibroma.

Bone mineral density in malnourished children without rachitic manifestations.

BACKGROUND: The purpose of this study was to determine bone mineral density (BMD) of lumbar spine in malnourished children without rachitic manifestations, before and after dietary treatment and vitamin D supplementation, and to compare with healthy children of the same community. METHODS: The subjects were 41 children with malnutrition and 21 healthy controls. None of the children had clinical, biochemical and/or radiological rickets features. The patients had moderate 15 and severe 26 malnutrition according to Gomez's criteria. Using the Wellcome Classification, marasmus was diagnosed in 16 children, kwashiorkor in 10 children. The children with malnutrition were given vitamin D supplementation. RESULTS: BMD was lower in children with malnutrition than in controls (P < 0.01). Mineralization significantly effected the severity of malnutrition (P < 0.01). BMD in kwashiorkor was similar to that of marasmus. The mean BMD level of infants receiving 400 IU of vitamin D daily was similar to that of infants receiving 800 IU of vitamin D daily at the beginning of treatment. In two supplementation groups, the BMD gradually increased during the first 3 months of treatment, but this increase in the infants receiving 800 IU of vitamin D daily was significantly higher than that in the infants receiving 400 IU of vitamin D daily. CONCLUSION: Measurements of BMD in children with malnutrition, especially severe malnutrition, are to be recommended in the initial assessment of the severity of osteopenia and in the follow up to monitor the response to therapy. Children with malnutrition should be given 800 IU of vitamin D daily. The loss of BMD must be accepted as a complication of malnutrition.

99mTc-HMPAO labelled leucocyte scintigraphy in the diagnosis of pelvic inflammatory disease.

BACKGROUND: Scintigraphy using leucocytes labelled with 99mTc hexamethylpropyleneamine oxime (99mTc-HMPAO) is widely used for the localization of inflammatory foci and abscesses in cases of acute pelvic inflammatory disease, which is one of the serious health problems of women of child-bearing age. Early diagnosis and effective management of this condition can preserve fertility and prevent serious complications, such as peritonitis and sepsis. AIM: To evaluate the importance of scintigraphy using 99mTc-HMPAO labelled leucocytes in the early diagnosis of patients with pelvic inflammatory disease. METHODS: Fifteen women (mean age 29.2+/-8 years, range 25-46 years) with suspicion of pyogenic pelvic inflammatory disease based on gynaecological examinations, clinical findings and blood tests were included in this study. The patients received 555 MBq 99mTc-HMPAO labelled leucocytes, by injection, and were scanned by scintigraphy 0.5-1, 3 and 24 h later in the anterior abdominal projection. Ten of the patients were then evaluated by abdominal or transvaginal ultrasonography, four by computed tomography and two by both ultrasound and computed tomography. The final diagnosis was made by surgical intervention. RESULTS: Scintigraphy detected pelvic inflammatory disease in five of the patients. In three of them the disease was apparent on the scans taken at 0.5-1 h, and in the other two it was apparent at 3 h. There were no false negative results, and one false positive result. The scan accurately reflected the absence of pelvic inflammatory disease in nine patients showing non-pathological tracer uptake in the lower abdominal region. CONCLUSION: We showed that scintigraphy with 99mTc-HMPAO labelled leucocytes had a sensitivity of 100%, specificity of 90%, overall accuracy of 93%, positive predictive value of 83%, and negative predictive value of 100%. Therefore, we conclude that 99mTc-HMPAO labelled leucocyte scans provide a rapid and highly accurate method for diagnosing pelvic inflammatory disease in women of child-bearing age. This adds an important contribution to the diagnosis of infection and helps determine further operative or conservative treatment.

Bilateral choanal atresia; evaluation with scintigraphy: case report.

Bilateral choanal atresia is a rare congenital anomaly that may cause severe neonatal respiratory distress. The clinical presentation varies from immediate postnatal cyanosis and respiratory distress to nasal obstruction with an associated persistent mucoid discharge. The aim of this study was to evaluate the effect of bilateral choanal atresia preoperatively and postoperatively on nasal mucociliary clearance with the radioisotope method (using technetium-99m macroaggregated albumin). We present a 17-year-old girl with bilateral choanal atresia treated by transnasal endoscopic surgery. The patient was free of symptoms for three years postoperatively. Mucociliary activity was returned to normal images.

Detection of femoral artery calcification by bone scintigraphy

Scintigraphy with technetium-99m methylene diphosphonate (MDP) was performed in a 76-year-old male with prostatic cancer. Tc-99m MDP bone scintigraphy showed a linear markedly increased accumulation of radioactivity in both femoral arteries. Radiopharmaceutical uptake in femoral arteries was confirmed with a colour Doppler ultrasonography as femoral artery calcification. This increased uptake of Tc-99m MDP in the patient is strongly related to the calcium deposition. Tc-99m MDP scintigraphy depicts a wide spectrum of nonosseous disorders. Abnormal soft tissue uptake of Tc-99m MDP demostrates hormonal, neoplastic, inflammatory, ischemic, traumatic, excretory and artifactural entities. Hormonal disturbances in calcium metabolism, particularly in hyperparathyroidism, can lead to metastatic calcification and can be visualized with Tc-99m MDP scintigraphy. Mechanisms leading to increased extraosseous Tc-99m MDP uptake include extracellular fluid expansion, enhanced regional vascularity and permeability, and the presence of other metallic ions (eg, iron and magnesium) are also important