Quantitative immunofluorescence assay for cyclobutyldithymidine dimers in individual mammalian cells

An indirect immunofluorescence procedure was developed for themeasurement of cyclobutyl dithymidine dimers in DNA of individualSyrian hamster embryo cells using a specific monoclonal antibody.A fluorescein-labeled secondary antibody and a fluorochromewhich binds to DNA were used to measure the photoproduct andtotal DNA in the same nucleus. Fluorescence intensity was quantitatedwith a computer-assisted microfluorometric system which wascalibrated with a uranyl oxide impregnated glass slide. Similardose-response curves, i.e. normalized fluorescence intensityplotted as a function of dose of germicidal irradiation, wereobtained with two different cell types. Normalized fluorescenceintensity per nucleus was related to thymidine dimer contentwith a competitive enzyme-linked imnmunosorbent assay usingDNA isolated from cells given doses of germicidal irradiationidentical to those used in the immunofluorescence assay. Thymidinedimer levels produced by 10 J/m² of germicidal irradiation (8x10⁵/nucleus)and which allow for 15–30% cell survival can readily bedetected. The specific monoclonal antibody was labeled withtritium and used in the immunofluorescence assay to relate thenumber of antibodies bound to the number of thynudine dimersper cell. The data revealed that 45% of the thymidine dimersin cells exposed to 100 J/m² of germicidal irradiation and essentiallyall the T<>T in cells receiving 20 J/m² were being detectedin the indirect immunofluorescence assay. This technique canprovide a sensitive means for measuring various types of DNAdamage in individual cells given that the appropriate probesare available. It can be especially useful for monitoring occupationallyor environmentally exposed populations where usually only smallsamples of cells or tissues are available.     

p53-dependent delayed effects of radiation vary according to time of irradiation of p53 + / ? mice

We previously reported that in p53 ^{+ / −} mice that had been given a whole-body dose of 3 Gy at 8 weeks of age, p53-dependent delayed effects of radiation, as manifested in T-cell receptor (TCR) variant fractions (VF) instability in mouse splenocytes, were biphasic, namely, induction of TCR-VF mutation reappeared at 44 weeks. The manifestation of the delayed effects and the measures of biological markers varied according to the timing of irradiation. We also reported that the decrease in function of the p53 gene was related to the effects of a delayed mutation. In the present study, we investigated the functions and mutations of the p53 gene in old age for p53 ^{+ / −} mice following irradiation at various ages. p53 ^{+ / −} mice were given a whole-body dose of 3 Gy at 8, 28 or 40 weeks of age. There were significant differences for all variables tested at 8 weeks of age. This was similarly the case for mice irradiated at 28 weeks of age, in which there were also significant differences in TCR VF and the percentage of apoptosis. In mice irradiated at 40 weeks of age, there were significant differences for all considered variables except for the p53 allele. We demonstrated that the different patterns of delayed mutation of the p53 gene at 56 weeks of age depended on the age at which mice had undergone 3-Gy whole-body irradiation. Our conclusions are limited to variation in p53-dependent delayed effects according to the time of irradiation.     

The impact of exercise on sleep in people with Parkinson’s disease a scoping review

While high intensity exercise is associated with improvement of both motor and non-motor symptoms in Parkinson’s disease (PD), there is limited evidence on its impact on sleep disturbances in PD. This scoping review aims to provide a preliminary statement of the potential size and scope of available evidence for the interaction between exercise and sleep in people with PD. Research to date on non-motor symptoms of PD is broad, with scarce information regarding specific effects of exercise on sleep. A systematic literature search was conducted through three phases. Fifteen articles met the inclusion criteria for this study. Resistive exercise and multimodal exercise programs were frequently studied and found to improve sleep and decrease sleep-related disorders. These findings suggest that exercise programs may improve sleep and other non-motor symptoms of PD. The research was inconclusive when comparing the effects of high and low intensity exercises. Further research on the interaction between exercise and sleep in PD may have implications for rehabilitative therapy interventions.     

Management of syringomyelia associated with tuberculous meningitis: A case report and systematic review of the literature

Determinants of tuberculosis (TB) syringomyelia, its management options and outcomes are still under investigation. The aim of this study is to present a case of TB syringomyelia with markedly improved symptoms status-post surgery and to understand the clinical characteristics and outcomes of 33 TB syringomyelia cases reported in the literature. Specifically, we examined the differences between patients who were managed medically and those who underwent surgical intervention. Inclusion criteria for the cases were (1) syringomyelia caused by TB infection rather than co-occurrence of these conditions, (2) management protocol described, and (3) post-treatment outcome described. The median age was 30 years (interquartile range (IQR): 23–40) with 55% males. The median time between TB onset to syringomyelia diagnosis was 2 years. Nineteen patients were surgically treated, 11 were medically treated, and 3 received no treatment. Twenty-one patients showed improvement in at least one prior symptom, but no patient experienced a full recovery. Those that underwent surgical intervention were more likely to have TB meningitis (95% vs. 64%, p < 0.05) upon initial TB presentation and have a greater interval between TB onset and syringomyelia presentation (median of 2.6 vs. 0.33 years, ns). A greater proportion of the surgically managed patients experienced improvement in any symptom (74% vs. 45%, ns). Future case-controlled studies with larger sample sizes are required to validate and further understand the outcomes of surgically-managed TB syringomyelia.     

The role of the anterior talofibular ligament area as a morphological parameter of the chronic ankle sprain

BackgroundRepetitive microtrauma can result in a hypertrophied ATFL. Previous studies have found that the anterior talofibular ligament thickness (ATFLT) is correlated with lateral ankle sprains, ligament injuries and chronic stroke in patients, and thickened anterior talofibular ligament (ATFL) has been considered to be a major morphologic parameter of hypertrophied ATFL. However, hypertrophy is different from thickness. Thus, we devised the anterior talofibular ligament area (ATFLA) as a new morphological parameter to evaluate the hypertrophy of the whole ATFL.MethodsATFL samples were collected from 53 patients with sprain group and from 50 control subjects who underwent magnetic resonance imaging (MRI) of the ankle and revealed no evidence of lateral ankle injury. Axial T1-weighted MRI images were collected at the ankle level from all subjects. We measured the ATFLA and ATFLT at the anterior margin of the fibular malleolus to the talus bone on the MRI using a picture archiving and communications system. The ATFLA was measured as the whole cross-sectional ligament area of the ATFL that was most hypertrophied in the axial MR images. The ATFLT was measured as the thickest point between the lateral malleolus and the talus of the ankle.ResultsThe average ATFLA was 25.0 ± 6.0 mm² in the control group and 47.1 ± 10.4 mm² in the sprain group. The average ATFLT was 2.3 ± 0.6 mm in the control group and 3.8 ± 0.6 mm in the hypertrophied group. Patients in sprain group had significantly greater ATFLA (p < 0.001) and ATFLT (p < 0.001) than the control subjects. A Receiver Operator Characteristics curve analysis showed that the best cut-off point of the ATFLA was 34.8 mm², with 94.3% sensitivity, 94.0% specificity, and an AUC of 0.97 (95% CI, 0.94–1.00). The optimal cut-off point of the ATFLT was 3.1 mm, with 86.8% sensitivity, 86.0% specificity, and AUC of 0.95 (95% CI, 0.92–0.99).ConclusionATFLA is a new morphological parameter for evaluating chronic ankle sprain, and may even be more sensitive than ATFLT.