Optical tracking of contrast medium bolus to optimize bolus shape and timing in dynamic computed tomography

One of the biggest challenges in dynamic contrast-enhanced CT is the optimal synchronization of scan start and duration with contrast medium administration in order to optimize image contrast and to reduce the amount of contrast medium. We present a new optically based approach, which was developed to investigate and optimize bolus timing and shape. The time-concentration curve of an intravenously injected test bolus of a dye is measured in peripheral vessels with an optical sensor prior to the diagnostic CT scan. The curves can be used to assess bolus shapes as a function of injection protocols and to determine contrast medium arrival times. Preliminary results for phantom and animal experiments showed the expected linear behavior between dye concentration and absorption. The kinetics of the dye was compared to iodinated contrast medium and was found to be in good agreement. The contrast enhancement curves were reliably detected in three mice with individual bolus shapes and delay times of 2.1, 3.5 and 6.1 s, respectively. The optical sensor appears to be a promising approach to optimize injection protocols and contrast enhancement timing and is applicable to all modalities without implying any additional radiation dose. Clinical tests are still necessary.     

Binary Segmentation Masks Can Improve Intrasubject Registration Accuracy of Bone Structures in CT Images

Registration of bone structures is a common problem in medical research as well as in clinical applications. Intrasubject rigid 3D monomodality registration of segmented bone structures of CT images and multimodality registration of μMR and segmented μCT bone images were performed with the multiresolution intensity-based technique implemented in ITK. The registration results for binary volumes of interest (VOI) masks and for segmented gray value VOIs were compared. To determine the registration quality, in the monomodality case the sum of squared difference, the sum of absolute differences, and the normalized symmetric difference of binary masks and in the multimodality case Mattes mutual information were applied. The use of binary VOI masks was significantly superior to the use of gray value VOIs.     

Genital Vitiligo Treated by Autologous, Noncultured Melanocyte-Keratinocyte Cell Transplantation

Background. Genital vitiligo is common and has a deleterious effect on the psychosexual function of patients. It is well known that glabrous skin (non–hair-bearing skin such as below the ankles, genitalia, lips, distal ends of fingers) rarely responds to the therapy unless it has some residual pigment.
Objective. The objective was to report genital vitiligo treated successfully by autologous, noncultured, melanocyte-keratinocyte cell transplantation.
Methods. Three cases of clinically stable genital vitiligo were treated by autologous, noncultured melanocyte-keratinocyte cell transplantation.
Results. All lesions treated repigmented almost completely. All patients were very satisfied with the excellent cosmetic results.
Conclusion. Autologous, noncultured melanocyte-keratinocyte cell transplantation may be an effective surgical treatment for management of genital vitiligo.
SANJEEV V. MULEKAR, MD, AHMED AL ISSA, MD, ABDULLAH AL EISSA, MD, AND MARWAN ASAAD, MD, HAVE INDICATED NO SIGNIFICANT INTEREST WITH COMMERCIAL SUPPORTERS.     

Actin-dependent vacuolar occupancy of the cell determines auxin-induced growth repression

The cytoskeleton is an early attribute of cellular life, and its main components are composed of conserved proteins. The actin cytoskeleton has a direct impact on the control of cell size in animal cells, but its mechanistic contribution to cellular growth in plants remains largely elusive. Here, we reveal a role of actin in regulating cell size in plants. The actin cytoskeleton shows proximity to vacuoles, and the phytohormone auxin not only controls the organization of actin filaments but also impacts vacuolar morphogenesis in an actin-dependent manner. Pharmacological and genetic interference with the actin–myosin system abolishes the effect of auxin on vacuoles and thus disrupts its negative influence on cellular growth. SEM-based 3D nanometer-resolution imaging of the vacuoles revealed that auxin controls the constriction and luminal size of the vacuole. We show that this actin-dependent mechanism controls the relative vacuolar occupancy of the cell, thus suggesting an unanticipated mechanism for cytosol homeostasis during cellular growth.Actin filaments and its myosin motor proteins control a multitude of diverse cellular processes in animal cells, such as muscle contraction, cell motility, as well as vesicle and organelle movements (1). In animals, actin has a strong impact on the regulation of cellular shape and thus on cell size (2). Unlike animal cells, plant cells are sheathed by shape-giving cell walls, rendering them largely immobile. Despite this difference, the plant actin cytoskeleton has a conserved function in vesicle trafficking and organelle movement (3). Compared with animals, the role of actin in controlling cell size in plants is not clear and remains to be addressed. The phytohormone auxin is a crucial regulator of cell-size control in plants (4). Several studies suggest that the plant-specific growth regulator auxin affects the actin cytoskeleton (5–10). These studies concentrated on the effect of auxin on cortical actin and its contribution to processes close to the plasma membrane, such as endocytosis and exocytosis (5–11). Here we show that the actin cytoskeleton also is required for auxin processes beyond the plasma membrane, contributing to vacuolar morphogenesis and consequently to the regulation of cell size in plants.     

The Effect of Vitamin A Supplementation on Retinoic Acid-Related Orphan Receptor γt (RORγt) and Interleukin-17 (IL-17) Gene Expression in Avonex-Treated Multiple Sclerotic Patients

The aim of this study was to investigate the role of vitamin A on RORγt and IL-17 gene expression in multiple sclerotic patients. Patients in the vitamin A group received 25,000 IU retinyl palmitate per day, while patients in the placebo group took one capsule of placebo per day for 6 months. Gene expression was measured by real-time PCR at the first and end of the study. The results of this study show that vitamin A downregulates IL-17 and RORγt gene expression. No changes in gene expression occurred in the placebo group.     

Effect of establishing pain committee on the pain assessment skills of paediatric nurses

Successful pain management relies on pain assessment. The purpose of this study is to investigate the effect of establishing pain committee on pain assessment skills of paediatric nurses. We used a quasi‐experimental design. The study was conducted in surgery, emergency and orthopaedic wards of two teaching hospitals selected through simple random sampling. The intervention consisted of establishing a pain committee, the steps of which included organizing (3 months), holding workshop (five sessions) and clinical training (1 week). We found that the scores in the intervention group were significantly higher than those in the control group. Therefore, establishing pain committee in the management level of nursing improves nurses' pain assessment skills.     

Case report: B-cell lymphoma of the maxillary sinus.

The radiographic manifestation of malignant lesions of the maxillary sinus on dental radiographs may be nonspecific, making it difficult to differentiate the lesion from disease of odontogenic origin or more benign sinus pathoses. A radiopaque mass in the maxillary sinus, resulting from a malignant neoplasm growing within or extending into the sinus, can be easily confused with the mass of a mucous retention pseudocyst. Similarly, a malignant growth in the early stages of development can produce radiographic patterns in the alveolar process that may resemble inflammation of odontogenic origin. A case of B-cell lymphoma is reported. The lesion involved the maxillary alveolar process and sinus, producing such a radiographic pattern on the panoramic radiograph. Radiographic and clinical features that should be considered in establishing a differential diagnosis of malignant disease are discussed.