Using a generative adversarial network to generate synthetic MRI images for multi-class automatic segmentation of brain tumors.

Challenging tasks such as lesion segmentation, classification, and analysis for the assessment of disease progression can be automatically achieved using deep learning (DL)-based algorithms. DL techniques such as 3D convolutional neural networks are trained using heterogeneous volumetric imaging data such as MRI, CT, and PET, among others. However, DL-based methods are usually only applicable in the presence of the desired number of inputs. In the absence of one of the required inputs, the method cannot be used. By implementing a generative adversarial network (GAN), we aim to apply multi-label automatic segmentation of brain tumors to synthetic images when not all inputs are present. The implemented GAN is based on the Pix2Pix architecture and has been extended to a 3D framework named Pix2PixNIfTI. For this study, 1,251 patients of the BraTS2021 dataset comprising sequences such as T1w, T2w, T1CE, and FLAIR images equipped with respective multi-label segmentation were used. This dataset was used for training the Pix2PixNIfTI model for generating synthetic MRI images of all the image contrasts. The segmentation model, namely DeepMedic, was trained in a five-fold cross-validation manner for brain tumor segmentation and tested using the original inputs as the gold standard. The inference of trained segmentation models was later applied to synthetic images replacing missing input, in combination with other original images to identify the efficacy of generated images in achieving multi-class segmentation. For the multi-class segmentation using synthetic data or lesser inputs, the dice scores were observed to be significantly reduced but remained similar in range for the whole tumor when compared with evaluated original image segmentation (e.g. mean dice of synthetic T2w prediction NC, 0.74 ± 0.30; ED, 0.81 ± 0.15; CET, 0.84 ± 0.21; WT, 0.90 ± 0.08). A standard paired t-tests with multiple comparison correction were performed to assess the difference between all regions (p < 0.05). The study concludes that the use of Pix2PixNIfTI allows us to segment brain tumors when one input image is missing.

Measuring hip muscle strength in patients with femoroacetabular impingement and other hip pathologies: A systematic review.

OBJECTIVES: The aim of this study was to systematically review the literature on measurement of muscle strength in patients with femoroacetabular impingement (FAI) and other pathologies and to suggest guidelines to standardise protocols for future research in the field. METHODS: The Cochrane and PubMed libraries were searched for any publications using the terms 'hip', 'muscle', 'strength', and 'measurement' in the 'Title, Abstract, Keywords' field. A further search was performed using the terms 'femoroacetabular' or 'impingement'. The search was limited to recent literature only. RESULTS: A total of 29 articles were reviewed to obtain information on a number of variables. These comprised the type of device used for measurement, rater standardisation, the type of movements tested, body positioning and comparative studies of muscle strength in FAI versus normal controls. The studies found that hip muscle strength is lower in patients with FAI; this is also true for the asymptomatic hip in patients with FAI. CONCLUSIONS: Current literature on this subject is limited and examines multiple variables. Our recommendations for achieving reproducible results include stabilising the patient, measuring isometric movements and maximising standardisation by using a single tester and familiarising the participants with the protocol. Further work must be done to demonstrate the reliability of any new testing method.Cite this article: E. Mayne, A. Memarzadeh, P. Raut, A. Arora, V. Khanduja. Measuring hip muscle strength in patients with femoroacetabular impingement and other hip pathologies: A systematic review. Bone Joint Res 2017;6:66-72. DOI: 10.1302/2046-3758.61.BJR-2016-0081.

Effect of HPMC and mannitol on drug release and bioadhesion behavior of buccal discs of buspirone hydrochloride: In-vitro and in-vivo pharmacokinetic studies.

Delivery of orally compromised therapeutic drug molecules to the systemic circulation via buccal route has gained a significant interest in recent past. Bioadhesive polymers play a major role in designing such buccal dosage forms, as they help in adhesion of designed delivery system to mucosal membrane and also prolong release of drug from delivery system. In the present study, HPMC (release retarding polymer) and mannitol (diluent and pore former) were used to prepare bioadhesive and controlled release buccal discs of buspirone hydrochloride (BS) by direct compression method. Compatibility of BS with various excipients used during the study was assessed using DSC and FTIR techniques. Effect of mannitol and HPMC on drug release and bioadhesive strength was studied using a 3(2) factorial design. The drug release rate from delivery system decreased with increasing levels of HPMC in formulations. However, bioadhesive strength of formulations increased with increasing proportion of HPMC in buccal discs. Increased levels of mannitol resulted in faster rate of drug release and rapid in vitro uptake of water due to the formation of channels in the matrix. Pharmacokinetic studies of designed bioadhesive buccal discs in rabbits demonstrated a 10-fold increase in bioavailability in comparison with oral bioavailability of buspirone reported.

Impact of colour pigments on biochemical parameters of bivalve, Lamellidens marginalis.

The present study was carried out to investigate the effect of colour pigments used for painting the decorative articles like idols, on the freshwater bivalve, Lamellidens marginalis. The effects of subchronic exposure were studied by the changes in the biochemical constituents like total protein, glycogen and lactic acid, in different tissues like muscle, mantle, gills, foot, hepatopancreas and gonads for 10 and 20 days period. The glycogen contents in the muscle, mantle and gonads were significantly decreased with increase in concentration of colour pigments. It decreased from 26.77 mg gm(-1) in control to 19.17 mg gm(-1) at 900 ppm after 20 days of exposure; whereas protein contents in the tissues studied decreased significantly from 22.5 mg gm(-1) in control to 15.5 mg gm(-1) at 900 ppm after 10 days of exposure. The increase in lactic acid content in all the tissues except gills and gonads may be due to acute hypoxia.

HLA antigen distribution in renal transplant recipients and donors.

BACKGROUND: HLA typing analysis is important in renal transplant patient. This study is the first report from Nepal to find out distribution of HLA A, B, DR antigen in live related renal transplant recipients and donors from Nepal. The aim of this study was to investigate the distribution of HLA in the live related renal transplant recipients and donors of Nepal. METHODS: In a retrospective study, HLA patterns were defined in 100 live related renal transplant recipients and donors. One year study is done from June 2011 to May 2012. The study was done by using sequence specific oligonucleotides primers and polymerase chain reaction and assay. Allele frequencies were obtained by direct counting. RESULTS: A total of 12 HLA-A, 15 HLA-B and 13 HLA-DRB1 alleles were identified at the four-digit level in the live related renal transplant recipients and donors of Nepal. High frequency alleles were HLA-A*11 (34.5%), A*24 (17%), A*33 (13%); HLA-B*15(27%), B*35(19%), B*40 (10%); HLA-DRB1*15 (33.5%), DRB1*12 (21.4%) and DRB1*04 (7.32%). CONCLUSIONS: These results showed considerable heterogeneity in both HLA class I and class II antigens. To reduce the risk of allograft rejection, transplantation from HLA matched donors is recommended.

An unusual cause for sicca syndrome.

We present a case of a 47-year-old female who presented with sicca symptoms since three months. As per the Revised International Classification Criteria for Sjögren's syndrome, patient was diagnosed as primary Sjögren's syndrome (SS). Patients with SS are known to have circulating monoclonal immunoglobulins. Serum electrophoresis revealed M band with serum gamma globulin concentration of 46 g/L. Bone marrow aspiration revealed 28% plasma cells. In absence of myeloma-related organ damage, a diagnosis of smouldering myeloma (MM) was made. Patient was treated with thalidomide and dexamethasone. Sicca symptoms resolved with anti-myeloma treatment. Although MM can occur as a complication of SS, MM can also rarely present as SS. In the present case, the short duration of sicca symptoms and response of these symptoms to anti-myeloma treatment support the diagnosis of MM presenting as SS. The present case highlights the importance of serum electrophoresis in patients presenting as SS.

Microsatellite unstable colorectal cancer cell lines with truncating TGFbetaRII mutations remain sensitive to endogenous TGFbeta.

Disruptions to the TGFbeta signalling pathway have been implicated in most human adenocarcinomas. As cancers progress, many acquire resistance to the growth-suppressing properties of TGFbeta while retaining sensitivity to its tumour-promoting effects. Microsatellite unstable colorectal cancers (MSI-H CRCs) possess truncating mutations in the type II TGFbeta receptor (TGFbetaRII) gene that have been assumed to render these tumours insensitive to TGFbeta. However, numerous reports of TGFbetaRII bypass exist and this study was thus undertaken in order to clarify the true extent of TGFbeta sensitivity in MSI-H CRCs. Using stimulation with exogenous TGFbeta, we demonstrated that, while MSI-H CRCs are capable of binding soluble TGFbeta, two out of three cell lines examined remain refractory to its signalling effects. In contrast, use of a specific inhibitor of the type I TGFbeta receptor (TGFbetaRI) revealed that all remain sensitive to signalling by endogenously produced TGFbeta. Specifically, autocrine signalling via TGFbetaRI mediates constitutive activation of Smad2 as well as repression of Erk signalling. Real-time PCR confirmed that these effects are sufficient to affect the expression level of various TGFbeta-modulated genes. An invasion assay revealed that autocrine TGFbetaRI signalling also promotes the invasion capacity of MSI-H CRCs to an extent similar to that seen in their non-MSI-H counterparts. Independent TGFbetaRI signalling, however, has no effect on the rate of proliferation of MSI-H CRC cells. Together, these results demonstrate that MSI-H CRC cell lines are not completely refractory to TGFbeta, despite lacking functional TGFbetaRII. In addition to clarifying the true consequences of natural TGFbetaRII loss and the independent function of TGFbetaRI, our results highlight the selective nature of TGFbeta resistance developed by cancers.