Changes on NiTi orthodontic wired due to acidic fluoride solution

The effect of acidic fluoride solution on NiTi arch wires was examined by testing crystal structure, tensile strength, morphology after fracture, and element release from wire under four different test solutions after 1 or 3 d immersion. Three-day immersion in a 0.2%/pH 4 solution did not form any new crystal structure. However, tensile strength after immersion was changed compared to the as-received wires. 3M wires showed increased tensile strength whereas G&H and Ormco wires showed decreased strength. Significant difference in tensile strength was associated with the immersion period. The fractured wires showed dimple patterns in the inner part of the wire, and ductile features on the outer part. Element release in the test solution increased as NaF concentration and the period of immersion increased, and as pH valued decreased. Wires immersed in a 0.2%/pH 4 solution released several-fold greater amount of elements than wires in a 0.05%/pH 4 solution. Tensile strength and element release were affected by acidic fluoride solution. In particular, NaF concentration, pH value, and the period of immersion were the factors affecting these properties.     

A rapid method to determine tetrabromobisphenol a in rat serum and urine by liquid chromatography-tandem mass spectrometry

Tetrabromobisphenol A (TBBPA), one of the most widely used brominated flame retardants in the world, is used to improve fire safety of laminates in electrical and electronic equipment. A liquid chromatography-tandem mass spectrometry was developed for the determination of TBBPA in rat serum and urine, and applied to the toxicokinetic study of TBBPA in rats. Acceptable linearity was observed over the concentration ranges of 0.25–50 and 0.01–5 μg/mL in serum and urine, respectively. The limits of detection of TBBPA were 0.04 μg/mL in serum, and 0.0025 μg/mL in urine. The precisions for the assay in serum and urine were below 13 and 14%, respectively, and the accuracies ranged 95–111% and 98–101% for intraday and 97–107% and 97–102% for inter-day, respectively. Serum and urine concentrations of TBBPA were successfully monitored following oral administrations at the dose of 200 mg/kg in male Sprague Dawley rats. Toxic signs were not observed at 200 mg/kg of TBBPA. The present results suggest that the rapid method developed in the present study affords sensitivity, accuracy and precision necessary for quantitative measurements in toxicokinetic studies of TBBPA in vivo.     

Nutcracker syndrome in children with gross haematuria: Doppler sonographic evaluation of the left renal vein

Background: Nutcracker syndrome is characterized by gross haematuria caused by left renal vein (LRV) entrapment. Objective: To assess the role of LRV ultrasonography in the diagnosis of the nutcracker syndrome in children. Materials and methods: Twelve children (eight male, four female; mean age 12.8 years) with venographically confirmed nutcracker syndrome (LRV-IVC pressure gradient ≥3 mm Hg) underwent LRV sonography including Doppler spectral analysis (n=7). The diameter and peak velocity (PV) were measured at two sites of the LRV (renal hilum and aortomesenteric portion). The US findings of nutcracker syndrome were compared with those of 20 control subjects using the t-test. We identified the optimal cut-off value of the US parameters for the diagnosis of the nutcracker syndrome using ROC analysis. Results: The PV at the aortomesenteric portion and the ratio of the PV between the two measured points showed significant differences between the two groups (P<0.0001). The optimum cut-off values were found to be 4.7 for the PV ratio (sensitivity 100%, specificity 90%, accuracy 93%), and 93 cm/s for the PV at the aortomesenteric portion (sensitivity 100%, specificity 85%, accuracy 89%). Conclusion: LRV sonography, including Doppler spectral analysis, can demonstrate LRV entrapment haemodynamically.     

Heterogeneity Analysis of 18F-FDG Uptake in Differentiating Between Metastatic and Inflammatory Lymph Nodes in Adenocarcinoma of the Lung: Comparison with Other Parameters and its Application in a Clinical Setting

Purpose

Lymph node (LN) characterization is crucial in determining the stage and treatment decisions in patient with lung cancer. Although ¹⁸F-fluorodeoxyglucose positron emission tomography/computed tomography (¹⁸F-FDG PET/CT) has a higher diagnostic accuracy in LN characterization than anatomical imaging, differentiating between metastatic and inflammatory LNs is still challenging because both could show high ¹⁸F-FDG uptake. The purpose of this study was to assess if the heterogeneity of the ¹⁸F-FDG uptake could help in differentiating between inflammatory and metastatic LNs in lung cancer, and to compare with other parameters.

Methods

A total of 44 patients with adenocarcinoma of the lung, who underwent preoperative ¹⁸F-FDG PET/CT without having any previous treatments and were revealed to have ¹⁸F-FDG-avid LNs, were enrolled. There were 52 pathology-proven metastatic lymph nodes in 26 subjects. The pathology-proven metastatic LNs were compared with 42 pathology-proven inflammatory/benign LNs in 18 subjects. The coefficient of variation (CV) was used to assess the heterogeneity of ¹⁸F-FDG uptake by dividing the standard deviation of standardized uptake value (SUV) by mean SUV. The volume of interest was manually drawn based on the combined CT images of ¹⁸F-FDG PET/CT (no threshold is used). Comparisons were made with the maximum standardized uptake values (SUVmax), visual assessment of ¹⁸F-FDG uptake, longest diameter, and maximum Hounsfield units (HUmax).

Results

Metastatic lymph nodes tended to have higher CVs than the inflammatory LNs. The mean CV of metastatic LNs (0.30 ± 0.08; range: 0.08–0.55) was higher than that of inflammatory LNs (0.17 + 0.06; range, 0.07–0.32; P < 0.0001). On receiver operating characteristic (ROC) curve analysis, the area under curve was 0.901, and using 0.20 as cut-off value, sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and accuracy were 88.5 %, 76.2 %, 82.2 %, 84.3, and 83.0 % respectively. Accuracy of CV was slightly higher than SUVmax and diameter, but significantly higher than visual assessment and HUmax.

Conclusions

In patients with adenocarcinoma of the lung having no prior treatments, metastatic LNs showed more heterogeneous ¹⁸F-FDG uptake than inflammatory LNs. Measuring the CV of the SUV derived from a manual volume of interest (VOI) can be helpful in determining metastatic LN of adenocarcinoma of the lung. Including diagnostic criteria of CV into the diagnostic approach can increase the accuracy of mediastinal node status.     

Studies on the synthesis andin vitro antitumor activity of the isoquinolone derivatives

3-Arylisoquinolin-1(2H)-ones (2) are possible bioisosteres of the 5-[4'-(piperidinomethyl)phenyl]-2,3-dihydroimidazo[2,1-a]iso quinoline (1) which is in clinical evaluation for the treatment of cancer. Structure-activity relationship studies of 3-arylisoquinolin-1(2H)-ones (2) led to the synthesis of 3-arylquinolin-2(1H)-ones (3). A number of 3-phenyl substituted quinolin-2(1H)-ones were synthesized and tested for their in vitro antitumor activity against four different human tumor cell lines and 3-phenyl-N-benzyl-3,4-dihydroquinolin-2(1H)-one (12) showed the most potent activity.     

Polyneuropathy and Cerebral Infarction Complicating Scrub Typhus

We describe a 64-year-old man with scrub typhus who presented with both polyneuropathy and cerebral infarction. A eurological examination revealed a confused mental state, stiff neck, hearing impairment, symmetric weakness, sensory loss, and ataxia. Electrophysiologic studies showed demyelinating sensorimotor polyneuropathy and sensorineural hearing loss. Brain magnetic resonance imaging showed multiple infarctions. Brain involvement or polyneuropathy associated with scrub typhus has been rarely reported, and the pathogenic mechanism underlying the multiple neurological complications remains to be elucidated.