Objective To investigate the dosimetric properties of PTW 60019 synthetic diamond detector in small photon beams.Methods A PTW 60019 synthetic diamond detector was tested under 6 and 10 MV photon beams,respectively.Linearity with dose,dose rate dependence and off-axis ratio were measured and compared to those measured by an IBA SFD.Percentage depth doses were measured and compared to those measured by an IBA SFD and a PTW 31010 semiflex chamber.Total scatter factors were measured and compared to those measured by an IBA SFD and a PTW 31016 PinPoint chamber.Results The dose response of a PTW 60019 synthetic diamond detector showed a good linear behavior as a function of dose,with observed deviations below 0.2％ over a dose range from 100 to 1 000 MU.The dose rate response was almost independent,with deviations below 0.2％ in the dose rate range from 37 to 614 MU/min.For the fields of 20-100 mm in diameter,there were dose differences in percentage depth doses within 1％ as compared to an IBA SFD and a PTW 31010 semiflex chamber.For the 10 mm diameter field,the differences were up to 5.8％ in the build-up region.Off-axis ratios measurements showed a good agreement among the involved detectors (＜ 1％).The higher differences appeared in the penumbra region.A good agreement was also found in terms of total scatter factor measurements for the related detectors.Conclusions The observed dosimetric properties of the PTW 60019 synthetic diamond detector indicate that it is a suitable candidate for small photon beam dosimetry.

PURPOSE: Subgaleal hemorrhage (SGH) is a rare but potentially fatal condition in newborns; however, few studies have reported on this condition. We aimed to identify the clinical characteristics and prognostic factors of SGH. METHODS: We retrospectively reviewed the medical records of 20 neonates diagnosed with SGH between January 2000 and June 2017. Enrolled neonates were clinically diagnosed when they had tender fluctuant scalp swelling that crossed the suture lines. RESULTS: Among 20 neonates with SGH, 12 were boys and 7 were girls; median hospitalization duration was 9.7±6.9 days. Fourteen neonates (70%) were born via vacuum-assisted vaginal delivery, and 4 via vacuum-assisted cesarean section. Of the neonates enrolled, half of them initially showed unstable vital signs, including apnea, desaturation, and cyanosis. Ten neonates had acidosis and 3 had asphyxia (pH < 7.0). Intracranial lesions associated with SGH were observed in 15 neonates (75%), including subdural hemorrhage (50%), subarachnoid hemorrhage (15%), intraventricular hemorrhage (5%), cerebral infarct (15%), skull fracture (30%), and cephalohematoma (20%). Twelve neonates (60%) required transfusion, 5 (25%) had seizures, and 3 (15%) died. Eight neonates (40%) had hyperbilirubinemia (mean total bilirubin, 13.1±7.4). The mean follow-up period was 8.4±7.5 months. At follow-up, 10 neonates (58.8%) were healthy with normal development, whereas 7 (41.2%) had neurological deficits. CONCLUSION: The morbidity rate was 41.2% due to severe metabolic acidosis. Anemia, hyperbilirubinemia, low Apgar scores, and subdural hemorrhage did not affect the prognosis. The long-term outcomes of neonates with SGH are generally good. Only arterial blood pH was significantly associated with death.
Acidosis ; Anemia ; Apnea ; Asphyxia ; Bilirubin ; Cesarean Section ; Cyanosis ; Female ; Follow-Up Studies ; Hematoma, Subdural ; Hemorrhage* ; Hospitalization ; Humans ; Hydrogen-Ion Concentration ; Hyperbilirubinemia ; Infant, Newborn* ; Medical Records ; Pregnancy ; Prognosis* ; Retrospective Studies ; Scalp ; Seizures ; Skull Fractures ; Subarachnoid Hemorrhage ; Sutures ; Vacuum Extraction, Obstetrical ; Vital Signs

Neurofibromatosis type 1 (NF1) is a common neurocutaneous syndrome that presents with multiple café-au-lait spots, skinfold freckling, dermatofibromas, neurofibromas, and Lisch nodules. Mutations of the NF1 gene, encoding the protein neurofibromin, have been identified as the cause of this disease. NF1 can also present with precocious puberty and be associated with optic pathway tumors. Hypothalamic hamartoma as the cause of precocious puberty in patients with NF1 has been rarely described in the literature. Here, we report the findings for a patient with NF1 and precocious puberty associated with a hypothalamic hamartoma who had a newly discovered 14-bp deletion mutation in exon 5 of NF1. To our knowledge, this is the first time this combination is reported in the literature.
Adolescent ; Child* ; Exons ; Genes, Neurofibromatosis 1 ; Hamartoma* ; Histiocytoma, Benign Fibrous ; Humans ; Hypothalamic Diseases ; Neurocutaneous Syndromes ; Neurofibroma ; Neurofibromatoses* ; Neurofibromatosis 1* ; Neurofibromin 1 ; Puberty ; Puberty, Precocious* ; Sequence Deletion

BACKGROUND: This study aimed to evaluate the efficacy of combined vancomycin and steroid therapy for the treatment of culture-proven bacterial meningitis in pediatric patients. MATERIALS AND METHODS: We identified a total of 86 pediatric patients with culture-positive cerebrospinal fluid who were treated at our facility between 2005 and 2015. Ten of these patients (5 boys and 5 girls) received first-line treatment with vancomycin as the initial form of therapy. All cultured bacteria were sensitive to vancomycin. We retrospectively analyzed these cases to examine the relationship between concomitant steroid dosage and antibiotic treatment effectiveness. RESULTS: Nine of the 10 patients included in our analysis received steroid treatment. Of these, 3 received high-dose steroid therapy and 6 received low-dose steroid therapy. Five patients did not respond to vancomycin, including all 3 patients in the high-dose steroid group and 2 patients in the low-dose steroid group. Our analysis confirmed that the response rate to vancomycin treatment was significantly reduced in accordance with steroid dosage (P = 0.035). Patients who did not to respond to vancomycin with concomitant high-dose steroid administration improved clinically after the substitution of vancomycin with teicoplanin. CONCLUSION: The use of steroids, especially in high doses, may impair the effectiveness of vancomycin for treating bacterial meningitis in pediatric patients. Physicians should be cautious when administering concomitant steroid therapy and should carefully monitor the steroid dosage.
Bacteria ; Cerebrospinal Fluid ; Humans ; Meningitis, Bacterial* ; Pediatrics ; Retrospective Studies ; Steroids ; Teicoplanin ; Treatment Outcome ; Vancomycin*

BACKGROUND: Mesenchymal stem cells (MSCs) are used for tissue regeneration due to their wide differentiation capacity and anti-inflammatory effects. Extracellular vesicles (EVs) derived from MSCs are also known for their regenerative effects as they contain nucleic acids, proteins, lipids, and cytokines similar to those of parental cells. There are several studies on the use of MSCs or EVs for tissue regeneration. However, the combinatorial effect of human MSCs (hMSCs) and EVs is not clear. In this study, we investigated the combinatorial effect of hMSCs and EVs on cartilage regeneration via co-encapsulation in a hyaluronic-acid (HA)-based hydrogel. METHODS: A methacrylic-acid-based HA hydrogel was prepared to encapsulate hMSCs and EVs in hydrogels. Through in vitro and in vivo analyses, we investigated the chondrogenic potential of the HA hydrogel-encapsulated with hMSCs and EVs. RESULTS: Co-encapsulation of hMSCs with EVs in the HA hydrogel increased the chondrogenic differentiation of hMSCs and regeneration of damaged cartilage tissue compared with that of the HA hydrogel loaded with hMSCs only. CONCLUSION Co-encapsulation of hMSCs and EVs in the HA hydrogel effectively enhances cartilage tissue regeneration due to the combinatorial therapeutic effect of hMSCs and EVs. Thus, in addition to cartilage tissue regeneration for the treatment of osteoarthritis, this approach would be a useful strategy to improve other types of tissue regeneration.

Objective:To study the influence of intensive magnet fields on radiation dose measurement, and to demonstrate the feasibility of measuring magnet field correction factor by a combination of medical linac with variable magnet fields in view of needing for accurate measurement of the doses from reference beam arising in MR image-guided radiotherapy.Methods:A photon radiation field and a variable field with 6 MV nominal high voltage were produced by using conventional medical electron linear accelerator equipped with a pair of electromagnets with magnetic field strength up to 1.5 T. Both PTW30013 and PTW31010 ionization chambers were used to test the responses of ionization chambers under different magnetic field strengths at four orientations in which the angles between ionization chamber axis and magnetic field direction were 0°, 180°, 90° and 270°, respectively. The magnetic factors, kB, M was calculated and compared with the reported values in literature. Results:The response of ionization chamber was proportional to the magnetic field strength before it reached to a peak around 1 T, and then fell down as the magnetic field continued to rise. When the magnetic field was 0.35 T, the magnetic factors of PTW31010 were 0.988 2±0.000 3 and 0.997 4±0.000 4 corresponding to 90° and 0° directions, the discrepancy between 0° scenario and literature was 0.05% ± 0.04%. When the magnetic field reached 1.5 T, the magnetic factor of PTW30013 was 0.958 9±0.000 5 at the situation of 90°, which was 0.60% ± 0.05% different from the literature value.Conclusions:Conventional 6 MV medical accelerator equipped with electromagnet can be used to measure the magnetic field factor of reference dosimetry for MRIgRT.

Objective To compare the impact of immobilization base plates composed of 7 types of materials on the MR-simulation imaging quality used for radiotherapy,aiming to provide reference data for clinical applications.Methods Using identical T1 and T2 sequences of Siemens MR-simulator,the MR images of ACR Large Phantom were acquired on the Orfit carbon fiber laminate,polycarbonate (PC),high precision base plate (HP),Jinan Huayuxin BR,WR,KP and SP materials,respectively.The imaging quality without any plate was used as the baseline data.The following metrics were compared:1.High-contrast spatial resolution:the sharpness of 3 pairs of hole arrays was observed,which represented resolutions of 1.1 mm,1.0 mm and 0.9 mm on the LR and AP directions;2.Image intensity uniformity in terms of percent integral uniformity (PIU):PIU =100× [1-((high-low)/(high +low)];3.Low-contrast resolution:distinguishable spokes representing resolutions of 5.1％,3.6％,2.5％ and 1.4％ were recorded.According to ACR recommendations,high-contrast resolution of 1.0 mm,PIU of T1WI and T2＞82％and low-contrast spoke difference＜3 were considered as clinically acceptable.Results High-contrast T1WI and T2WI resolutions of no plate,PC plate,HP plate and KP material were all 0.9 mm,and those of the remaining materials were =worse than 0.9 mm.The T1WI and T2WI PIU of no plate was＞87％,and the PIU of carbon fiber plate was reduced by＞ 25％.The PIU decrease of remaining materials was within ±4％.Except the carbon fiber plate,the low-contrast spokes of the remaining materials were within ±3 compared with the reference.Conclusions In clinical settings,carbon fiber plate exerts the most significant effect upon the MR-simulation imaging quality,which is unsuitable for MR simulation.Imaging quality of PC and HP plates are consistent with that of no plate.BR and KP materials exert slight effect upon MR signal.The remaining materials are of potential values for the manufacture of immobilization devices and accessories.