Investigation of accuracy in quantitation of 18F-FDG concentration of PET/CT

The PET/CT scanner has been recognized as a powerful diagnostic imaging modality in oncology and radiation treatment planning. Traditionally, PET has been used for quantitative analysis, and diagnostic interpretations of PET images greatly relied on a nuclear medicine physician’s experience and knowledge. The PET data set represents a positron emitter’s activity concentration as a gray scale in each pixel. The assurance of the quantitative accuracy of the PET data is critical for diagnosis and staging of disease and evaluation of treatment. The standard uptake value (SUV) is a widely employed parameter in clinical settings to distinguish malignant lesions from others. SUV is a rough normalization of radioactive tracer uptake where normal tissue uptake is unity. The PET scanner is a sensitive diagnostic method to detect small lesions such as lymph node metastasis less than 1 cm in diameter, whereas the CT scanner may be limited in detecting these lesions. The accuracy of quantitation of small lesions is critical for predicting prognosis or planning a treatment of the patient. PET/CT uses attenuation correction factors obtained from CT scanner data sets. Non-biological materials such as metals and contrast agents are recognized as a factor that leads to a wrong scaling factor in the PET image. We challenge the accuracy of the quantitative method that physicians routinely use as a parameter to distinguish malignant lesions from others under clinical settings in commercially available CT/PET scanners. First, we verified if we could recover constant activity concentration throughout the field of view for small identical activity concentration sources. Second, we tested how much the CT-based attenuation correction factor could be influenced by contrast agents. Third, we tested how much error in quantitation could be introduced by object size. Our data suggest that the routine normalization process of the PET scanner does not guarantee an accurate quantitation of discrete uniform activity sources in the PET/CT scanner. Also, activity concentrations greatly rely on an object’s dimensions and object size. A recovery correction factor is necessary on these quantitative data for oncological evaluation to assure accurate interpretation of the activity concentration. Development of parameters for quantitation other than SUV may overcome SUV’s inherent limitations reflecting patient-specific physiology and the imaging characteristics of individual scanners

Clinical Course before and after Cataract and Glaucoma Surgery under Systemic Infliximab Therapy in Patients with Behçet's Disease

www.karger.com/cop This is an Open Access article licensed under the terms of the Creative Commons Attribution-NonCommercial-NoDerivs 3.0 License (www.karger.com/OA-license), applicable to the online version of the article only. Distribution for non-commercial purposes only

Dietary acrylamide intake and the risk of liver cancer: The japan public health center-based prospective study

Acrylamide has been studied for its carcinogenicity in experimental animals, causing tumors at several organ sites, and has been considered probably carcinogenic to humans as well. Given the small number of epidemiological studies that have been conducted, it is still uncertain whether the consumption of acrylamide is associated with liver cancer. Therefore, we investigated a study to determine the possible relationship between acrylamide intake and the risk of developing liver cancer in the Japanese population. A total of 85,305 participants, from the Japan Public Health Center-based Prospective Study, who provided a validated food-frequency questionnaire were enrolled between 1995 and 1998. During a median of 16.0 years follow-up, 744 new liver cancer cases were identified. Compared to the lowest tertile of acrylamide consumption (<4.8 μg/day), the multivariate hazard ratio (HR) for the highest tertile (≥7.6 μg/day) was 0.79 (95% confidence interval [CI] = 0.65-0.95) for liver cancer using multivariable model 1, adjusted for smoking status, body mass index (BMI), physical activity, medical history, and alcohol consumption; whereas the inverse relationship disappeared after additionally adjusting for coffee consumption in multivariable model 2 with HR of 1.08 (95% CI = 0.87-1.34) for the highest tertile. The effect of dietary acrylamide intake on the risk of liver cancer was not observed in the Japanese population.Zha, L.; Sobue, T.; Kitamura, T.; Kitamura, Y.; Ishihara, J.; Kotemori, A.; Liu, R.; Ikeda, S.; Sawada, N.; Iwasaki, M.; Tsugane, S.; JPHC Study Group, f.t. Dietary Acrylamide Intake and the Risk of Liver Cancer: The Japan Public Health Center-Based Prospective Study. Nutrients 2020, 12, 2503. https://doi.org/10.3390/nu1209250

Maxillary stability after le Fort i osteotomy using three different plate systems

The purpose of this study was to compare postoperative changes in maxillary stability after Le Fort I osteotomy in three groups: with an unsintered hydroxyapatite (u-HA)/poly-l-lactic acid (PLLA) plate; a PLLA plate; and a titanium plate. Subjects comprised 60 Japanese patients diagnosed with mandibular prognathism. All patients underwent Le Fort I osteotomy and bilateral sagittal split ramus osteotomy. All patients were randomized in groups of 20 to a u-HA/PLLA group, a PLLA plate group and a titanium plate group. Changes in postoperative time intervals between the plate groups were compared using lateral and posteroanterior cephalography. The uHA/PLLA group had significantly larger values than the PLLA group regarding change of mx1-S perpendicular to SN between 3 and 12 months (T3) (P = 0.0269). The uHA/PLLA group had a significantly larger value than the PLLA group regarding change of S-A perpendicular to SN between baseline and 1 month (T1) (P = 0.0257). There was no significant difference in the other measurements. This study suggests that maxillary stability with satisfactory results could be obtained in the u-HA/PLLA, PLLA plate and titanium plate groups, although there was a slight difference between the u-HA/PLLA and PLLA plate systems in Le Fort I osteotomy. © 2012 International Association of Oral and Maxillofacial Surgeons

Changes in temporomandibular joint and ramus after sagittal split ramus osteotomy in mandibular prognathism patients with and without asymmetry

The purpose of this study was to examine the changes in the temporomandibular joint (TMJ) and ramus after sagittal split ramus osteotomy (SSRO) with and without Le Fort I osteotomy. The subjects consisted of 87 Japanese patients diagnosed with mandibular prognathism with and without asymmetry. They were divided into 2 groups (42 symmetric patients and 45 asymmetric patients). The TMJ disc tissue was assessed by magnetic resonance imaging (MRI) and the TMJ space, condylar and ramus angle were assessed by computed tomography (CT) preoperatively and postoperatively. Medial joint space on the deviation side in the asymmetry group was significantly larger than that in the symmetry group (P = 0.0043), and coronal ramus angle on the non-deviation side in the asymmetry group was significantly larger than that in the symmetry group preoperatively (P = 0.0240). The horizontal condylar angle on the deviation side in the asymmetry group was significantly larger than that in the symmetry group (P = 0.0302), posterior joint space on the non-deviation side in the symmetry group was significantly larger than that in the asymmetry group postoperatively (P = 0.00391). The postoperative anterior joint space was significantly larger than the preoperative value on both sides in both groups (the deviation side in the symmetry group: P = 0.0016, the non-deviation side in the symmetry group: P < 0.0001, the deviation side in the asymmetry group: P = 0.0040, the non-deviation side in the asymmetry group: P = 0.0024). The preoperative disc position could was not changed in either group. These results suggest that significant expansion of anterior joint space could occur on the deviation side and non-deviation side in the asymmetry group as well as on both sides in the symmetry group, although disc position did not change in either group. © 2011 European Association for Cranio-Maxillo-Facial Surgery

A hypothesis on the desired postoperative position of the condyle in orthognathic surgery: a review

It is very important to clarify the relationship between a dentofacial structure and a temporomandibular joint (TMJ) structure in orthognathic surgery. Recently, it was reported that the skeletal and occlusal patterns were associated with the TMJ morphology, including the disk position. In orthognathic surgery, some surgeons state that alterations in the condylar position from surgery can lead to malocclusion associated with the risk of early relapse, and also favor the development of temporomandibular disorders. For these reasons, several positioning devices have been proposed and applied, but now there is no scientific evidence to support the use of condylar positioning devices. There are some reasons why scientific evidence cannot be obtained; however, it also includes the question of whether the preoperative position of the condyle is the desired postoperative position. The purpose of this study was to verify the desired condylar position in orthognathic surgery, based on literature on the postoperative condylar position in orthognathic surgery. From the studies reviewed, it was suggested that the preoperative position of the condyle was not the desired postoperative position in orthognathic surgery. © 2012 Elsevier Inc. All rights reserved

MATURAÇÃO NATURAL DE CARNE-DE-SOL

A carne-de-sol é um produto levemente salgado, com ampla aceitação pelos brasileiros. Apesar da maciez ser um dos principais atributos de qualidade para carnes, inexistem publicações científicas relativas à maciez  de carne-de-sol. Visando melhorar esse atributo através da maturação natural e agregando valor ao produto elaborado, cortes cárneos bovinos (coxão mole) foram maturados a 0 ºC por diferentes tempos (0, 7, 14 e 21dias), foram processados em carne-de-sol seguindo metodologia empregada pelos produtores da região e a maciez foi aferida pela força de cisalhamento (FC), índice de fragmentação miofibrilar (IFM), quantificação de colágeno, comprimento de sarcômero (CS) e análise sensorial (ADQ). A maturação influenciou positivamente na maciez de todas as carnes e os resultados da FC, IFM, CS e ADQ foram sugestivos que a maturação das carnes por sete dias foi o tratamento mais indicado, não havendo diferença nos tempos superiores. A quantificação de colágeno não se apresentou como um eficaz instrumento avaliativo, provavelmente devido ao corte cárneo utilizado. Desta forma, sugere-se que a maturação como tratamento da matéria-prima para o processamento da carne-de-sol promove maciez, melhorando sua qualidade e assim, proporciona um incremento no valor agregado desse produto tradicional brasileir

Pyridoxal in the Cerebrospinal Fluid May Be a Better Indicator of Vitamin B6–dependent Epilepsy Than Pyridoxal 5′-Phosphate

Background We aimed to demonstrate the biochemical characteristics of vitamin B6–dependent epilepsy, with a particular focus on pyridoxal 5′-phosphate and pyridoxal in the cerebrospinal fluid. Methods Using our laboratory database, we identified patients with vitamin B6–dependent epilepsy and extracted their data on the concentrations of pyridoxal 5′-phosphate, pyridoxal, pipecolic acid, α-aminoadipic semialdehyde, and monoamine neurotransmitters. We compared the biochemical characteristics of these patients with those of other epilepsy patients with low pyridoxal 5′-phosphate concentrations. Results We identified seven patients with pyridoxine-dependent epilepsy caused by an ALDH7A1 gene abnormality, two patients with pyridoxal 5′-phosphate homeostasis protein deficiency, and 28 patients with other epilepsies with low cerebrospinal fluid pyridoxal 5′-phosphate concentrations. Cerebrospinal fluid pyridoxal and pyridoxal 5′-phosphate concentrations were low in patients with vitamin B6–dependent epilepsy but cerebrospinal fluid pyridoxal concentrations were not reduced in most patients with other epilepsies with low cerebrospinal fluid pyridoxal 5′-phosphate concentrations. Increase in 3-O-methyldopa and 5-hydroxytryptophan was demonstrated in some patients with vitamin B6–dependent epilepsy, suggestive of pyridoxal 5′-phosphate deficiency in the brain. Conclusions Low cerebrospinal fluid pyridoxal concentrations may be a better indicator of pyridoxal 5′-phosphate deficiency in the brain in vitamin B6–dependent epilepsy than low cerebrospinal fluid pyridoxal 5′-phosphate concentrations. This finding is especially helpful in individuals with suspected pyridoxal 5′-phosphate homeostasis protein deficiency, which does not have known biomarkers

Assessment of bone healing and hypoesthesia in the upper lip after Le Fort I osteotomy with self-setting α-tricalcium phosphate and absorbable plates

Purpose: The purpose of this study was to evaluate hypoesthesia of the upper lip and bone formation using self-setting α-tricalcium phosphate (Biopex ®) between the segments following Le Fort I osteotomy with bent absorbable plate fixation. Subjects and methods: The subjects were 47 patients (94 sides) who underwent Le Fort I osteotomy with and without mandibular osteotomy. They were divided into a Biopex ® group (48 sides) and a control group (46 sides). The Biopex ® was inserted into the anterior part of the gap between the segments in the Biopex ® group. Trigeminal nerve hypoesthesia at the region of the upper lip was assessed bilaterally by the trigeminal somatosensory-evoked potential (TSEP) method. The area of the Biopex ® at the anterior part in the maxilla was assessed immediately after surgery and 1 year postoperatively by computed tomography (CT). Results: The mean measurable period and standard deviation were 13.2 ± 18.5 weeks in the control group, 14.5 ± 17.9 weeks in the Biopex ® group, and there was no significant difference in TSEP. The area of the Biopex ® after 1 year was significantly smaller than that immediately after surgery (right side: P = 0.0024, left side: P = 0.0001) and bone defects between the segments could not be found in the Biopex ® group. In the control group, although the areas of bone defect after 1 year were significantly smaller than that immediately after surgery on the right side (P = 0.0133) and left side (P = 0.0469) in the frontal view, complete healing of the bone defects could be seen in 12 of 46 sides after 1 year. Conclusion: This study suggested that inserting Biopex ® in the gap between the maxillary segments was useful for new bone formation and it did not prevent the recovery of upper lip hypoesthesia after Le Fort I osteotomy with absorbable plate fixation. © 2012 European Association for Cranio-Maxillo-Facial Surgery