68 research outputs found

    Hyperacute Corticosteroid Treatment of Optic Neuritis at the Onset of Pain May Prevent Visual Loss: A Case Series

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    Aim. To show that high-dose corticosteroids may prevent visual loss in patients with optic neuritis (ON) treated at the prodromal, hyperacute, phase of retrobulbar pain. Method. Prospective case series: patients were recruited with a history of ON associated with pain. The patients were advised to report immediately to the investigators should the pain recur in either eye. Where possible, orbital magnetic resonance imaging (MRI) was performed to confirm a recurrence of ON and treatment with high-dose corticosteroids was commenced. Visual function and the patient's subjective account were monitored. Results. Eight patients (including cases of MS, CRION and NMO) presented in the hyperacute phase. MRI confirmed optic nerve inflammation in 5/5. Treatment was commenced immediately, and, in all cases, no visual loss ensued. Conclusion. MRI can be used to confirm acute optic neuritis prior to visual loss in the hyperacute phase. We suggest that treatment with high-dose corticosteroids may abort the attack and prevent loss of vision in patients with ON who are treated at the onset of pain. This has potential implications for the management of acute ON and also for our understanding of the pathogenesis and potential therapeutic targets in the neuroinflammatory conditions associated with ON

    Vibrations of axially travelling CNT reinforced beams with clamped-clamped boundary condition and an elastic support

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    Vibrational analysis in engineering systems of axially travelling beams has attracted noticeable attention due to the many applications, such as in robotic manipulators, cable tramways, textile fibres, and in general when there is the axial mass transport of a continuous structure. This article studies the vibrational response of axially-travelling, functionally-graded, carbon nanotube-(CNT)-reinforced beam structures, by investigating linear gyroscopic aspects, such as Argand diagrams. The distribution of CNT fibres is assumed to vary along the thickness of the beam. The Hamilton principle is employed to obtain the coupled axial and transverse behaviour of the beam, subjected to clamped-clamped boundary condition and additionally supported by a spring. These equations of motion are then solved using the modal decomposition technique for the Coriolis-dependent axial and transverse frequencies. For verification, the results are compared to the simplified case in the literature for CNT strengthened beams with zero axial velocity, the dynamics of axially travelling beams, studies of the clamped-clamped boundary condition, and the effects on the Argand diagrams, which have been performed. The Argand diagrams are plotted to examine the effects of varying axial speed on the different linear characteristics of vibration. Variation of the volume fraction of the CNT and the spring support, has also been considered, to understand its effects on the vibration characteristics. Results produced in this article are important in assisting in the future design of engineering devices involving axially travelling systems.Moaz Sibtain, Saxon Smith, Alireza Yeganehmehr, Oscar Zi Shao Ong, Mergen H. Ghayes

    The spectrum of psychosis in multiple sclerosis: a clinical case series

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    Psychosis in the context of multiple sclerosis (MS) has previously been reported as a rare occurrence. However, recent epidemiological studies have found prevalence rates of psychosis in MS that are two to three times higher than those in the general population. Untreated psychosis in patients with MS can adversely impact on adherence to MS medication, levels of disability, and quality of life. This retrospective case series describes the spectrum of psychotic disorders occurring in association with MS using demographic, clinical, and neuroimaging data. In the discussion, we highlight the particular diagnostic and treatment challenges that such disorders can pose for clinicians and through our case vignettes provide examples of potential interventions for this complex patient population

    Carbogen breathing increases prostate cancer oxygenation: a translational MRI study in murine xenografts and humans

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    Hypoxia has been associated with poor local tumour control and relapse in many cancer sites, including carcinoma of the prostate. This translational study tests whether breathing carbogen gas improves the oxygenation of human prostate carcinoma xenografts in mice and in human patients with prostate cancer. A total of 23 DU145 tumour-bearing mice, 17 PC3 tumour-bearing mice and 17 human patients with prostate cancer were investigated. Intrinsic susceptibility-weighted MRI was performed before and during a period of carbogen gas breathing. Quantitative R2* pixel maps were produced for each tumour and at each time point and changes in R2* induced by carbogen were determined. There was a mean reduction in R2* of 6.4% (P=0.003) for DU145 xenografts and 5.8% (P=0.007) for PC3 xenografts. In all, 14 human subjects were evaluable; 64% had reductions in tumour R2* during carbogen inhalation with a mean reduction of 21.6% (P=0.0005). Decreases in prostate tumour R2* in both animal models and human patients as a result of carbogen inhalation suggests the presence of significant hypoxia. The finding that carbogen gas breathing improves prostate tumour oxygenation provides a rationale for testing the radiosensitising effects of combining carbogen gas breathing with radiotherapy in prostate cancer patients

    Action Mechanism of Inhibin Ξ±-Subunit on the Development of Sertoli Cells and First Wave of Spermatogenesis in Mice

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    Inhibin is an important marker of Sertoli cell (SC) activity in animals with impaired spermatogenesis. However, the precise relationship between inhibin and SC activity is unknown. To investigate this relationship, we partially silenced both the transcription and translation of the gene for the Ξ±-subunit of inhibin, Inha, using recombinant pshRNA vectors developed with RNAi-Ready pSIREN-RetroQ-ZsGreen Vector (Clontech Laboratories, Mountain View, Calif). We found that Inha silencing suppresses the cell-cycle regulators Cyclin D1 and Cyclin E and up-regulates the cell-cycle inhibitor P21 (as detected by Western blot analysis), thereby increasing the number of SCs in the G1 phase of the cell cycle and decreasing the amount in the S-phase of the cell cycle (as detected by flow cytometry). Inha silencing also suppressed Pdgfa, Igf1, and Kitl mRNA levels and up-regulated Tgfbrs, Inhba, Inhbb, Cyp11a1, Dhh, and Tjp1 mRNA levels (as indicated by real-time polymerase chain reaction [PCR] analysis). These findings indicate that Inha has the potential to influence the availability of the ligand inhibin and its antagonist activin in the SC in an autocrine manner and inhibit the progression of SC from G1 to S. It may also participate in the development of the blood–testis barrier, Leydig cells, and spermatogenesis through its effect on Dhh, Tjp1, Kitl, and Pdgfa. Real-time PCR and Western blot analyses of Inha, Inhba, and Inhbb mRNA and Inha levels over time show that Inha plays an important role in the formation of round spermatid during the first wave of spermatogenesis in mice
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