476 research outputs found
A new case of t(4;12)(q12;p13) in a secondary acute myeloid leukemia with review of literature
Case report of a translocation : A new case of t(4;12)(q12;p13) in a secondary acute myeloid leukemia with review of literature
Crack-Like Processes Governing the Onset of Frictional Slip
We perform real-time measurements of the net contact area between two blocks
of like material at the onset of frictional slip. We show that the process of
interface detachment, which immediately precedes the inception of frictional
sliding, is governed by three different types of detachment fronts. These
crack-like detachment fronts differ by both their propagation velocities and by
the amount of net contact surface reduction caused by their passage. The most
rapid fronts propagate at intersonic velocities but generate a negligible
reduction in contact area across the interface. Sub-Rayleigh fronts are
crack-like modes which propagate at velocities up to the Rayleigh wave speed,
VR, and give rise to an approximate 10% reduction in net contact area. The most
efficient contact area reduction (~20%) is precipitated by the passage of slow
detachment fronts. These fronts propagate at anomalously slow velocities, which
are over an order of magnitude lower than VR yet orders of magnitude higher
than other characteristic velocity scales such as either slip or loading
velocities. Slow fronts are generated, in conjunction with intersonic fronts,
by the sudden arrest of sub-Rayleigh fronts. No overall sliding of the
interface occurs until either of the slower two fronts traverses the entire
interface, and motion at the leading edge of the interface is initiated. Slip
at the trailing edge of the interface accompanies the motion of both the slow
and sub-Rayleigh fronts. We might expect these modes to be important in both
fault nucleation and earthquake dynamics.Comment: 19 page, 5 figures, to appear in International Journal of Fractur
British Society of Gastroenterology guidelines for the diagnosis and management of cholangiocarcinoma
IFNβ Protects Neurons from Damage in a Murine Model of HIV-1 Associated Brain Injury.
Infection with human immunodeficiency virus-1 (HIV-1) causes brain injury. Type I interferons (IFNα/β) are critical mediators of any anti-viral immune response and IFNβ has been implicated in the temporary control of lentiviral infection in the brain. Here we show that transgenic mice expressing HIV-1 envelope glycoprotein 120 in their central nervous system (HIVgp120tg) mount a transient IFNβ response and provide evidence that IFNβ confers neuronal protection against HIVgp120 toxicity. In cerebrocortical cell cultures, neuroprotection by IFNβ against gp120 toxicity is dependent on IFNα receptor 1 (IFNAR1) and the β-chemokine CCL4, as IFNAR1 deficiency and neutralizing antibodies against CCL4, respectively, abolish the neuroprotective effects. We find in vivo that IFNβ mRNA is significantly increased in HIVgp120tg brains at 1.5, but not 3 or 6 months of age. However, a four-week intranasal IFNβ treatment of HIVgp120tg mice starting at 3.5 months of age increases expression of CCL4 and concomitantly protects neuronal dendrites and pre-synaptic terminals in cortex and hippocampus from gp120-induced damage. Moreover, in vivo and in vitro data suggests astrocytes are a major source of IFNβ-induced CCL4. Altogether, our results suggest exogenous IFNβ as a neuroprotective factor that has potential to ameliorate in vivo HIVgp120-induced brain injury
Rupture of the ilio-psoas tendon after a total hip arthroplasty: an unusual cause of radio-lucency of the lesser trochanter simulating a malignancy
Avulsion fracture or progressive radiolucency of lesser trochanter is considered a pathognomic finding in patients with malignancies. Although surgical release of the iliopsoas tendon may be required during a total hip arthroplasty (THA), there is no literature on spontaneous rupture of the ilio-psoas tendon after a THA causing significant functional impairment. We report here such a case, which developed progressive radiolucency of the lesser trochanter over six years after a THA, simulating a malignancy. The diagnosis was confirmed by MRI. Because of the chronic nature of the lesion, gross retraction of the tendon into the pelvis, and low demand of our patient, he was treated by physiotherapy and gait training. Injury to the ilio-psoas tendon can occur in various steps of the THA and extreme care should be taken to avoid this injury. Prevention during surgery is better, although there are no reports of repair in the THA setting. This condition should be considered in patients who present with progressive radioluceny of the lesser trochanter, especially in the setting of a hip/pelvic surgery. Awareness and earlier recognition of the signs and symptoms of this condition will aid in diagnosis and will direct appropriate management
Cerebrospinal fluid analysis in the HIV infection and compartmentalization of HIV in the central nervous system
Assessing the perceived impact of post Minamata amalgam phase down on oral health inequalities: a mixed-methods investigation
Background: Data from countries that have implemented a complete phase out of dental amalgam following the Minamata agreement suggest increased costs and time related to the placement of alternatives with consumers absorbing the additional costs. This aim of this study was to investigate the impact of a complete phase out of dental amalgam on oral health inequalities in particular for countries dependent on state run oral health services.
Methods: A mixed methods component design quantitative and qualitative study in the United Kingdom. The quantitative study involved acquisition and analysis of datasets from NHS Scotland to compare trends in placement of dental amalgam and a survey of GDPs in Yorkshire, UK. The qualitative study involved analysis of the free text of the survey and a supplementary secondary analysis of semi-structured interviews and focus groups with GDPs (private and NHS), dental school teaching leads and NHS dental commissioners to understand the impact of amalgam phase down on oral health inequalities.
Results: Time-trends for amalgam placement showed that there was a significant (p < 0.05) reduction in amalgam use compared with composites and glass ionomers. However dental amalgam still represented a large proportion (42%) of the restorations (circa 1.8 million) placed in the 2016–2017 financial year.
Survey respondents suggest that direct impacts of a phase down were related to increased costs and time to place alternative restorations and reduced quality of care. This in turn would lead to increased tooth extractions, reduced access to care and privatisation of dental services with the greatest impact on deprived populations.
Conclusion: Amalgam is still a widely placed material in state run oral health services. The complete phase down of dental amalgam poses a threat to such services and threatens to widen oral health inequalities. Our data suggest that a complete phase out is not currently feasible unless appropriate measures are in place to ensure cheaper, long-lasting and easy to use alternatives are available and can be readily adopted by primary care oral health providers
What Do We Know About Neuropsychological Aspects Of Schizophrenia?
Application of a neuropsychological perspective to the study of schizophrenia has established a number of important facts about this disorder. Some of the key findings from the existing literature are that, while neurocognitive impairment is present in most, if not all, persons with schizophrenia, there is both substantial interpatient heterogeneity and remarkable within-patient stability of cognitive function over the long-term course of the illness. Such findings have contributed to the firm establishment of neurobiologic models of schizophrenia, and thereby help to reduce the social stigma that was sometimes associated with purely psychogenic models popular during parts of the 20th century. Neuropsychological studies in recent decades have established the primacy of cognitive functions over psychopathologic symptoms as determinants of functional capacity and independence in everyday functioning. Although the cognitive benefits of both conventional and even second generation antipsychotic medications appear marginal at best, recognition of the primacy of cognitive deficits as determinants of functional disability in schizophrenia has catalyzed recent efforts to develop targeted treatments for the cognitive deficits of this disorder. Despite these accomplishments, however, some issues remain to be resolved. Efforts to firmly establish the specific neurocognitive/neuropathologic systems responsible for schizophrenia remain elusive, as do efforts to definitively demonstrate the specific cognitive deficits underlying specific forms of functional impairment. Further progress may be fostered by recent initiatives to integrate neuropsychological studies with experimental neuroscience, perhaps leading to measures of deficits in cognitive processes more clearly associated with specific, identifiable brain systems
Pattern of neuropsychological performance among HIV positive patients in Uganda
BACKGROUND: Few studies have examined cognitive functioning of HIV positive patients in sub-Saharan Africa. It cannot be assumed that HIV positive patients in Africa exhibit the same declines as patients in high-resource settings, since there are differences that may influence cognitive functioning including nutrition, history of concomitant disease, and varying HIV strains, among other possibilities. Part of the difficulty of specifying abnormalities in neuropsychological functioning among African HIV positive patients is that there are no readily available African normative databases. The purpose of the current study was to evaluate the pattern of neuropsychological performance in a sample of HIV positive patients in comparison to HIV negative control subjects in Uganda. METHODS: The neuropsychological test scores of 110 HIV positive patients (WHO Stage 2, n = 21; WHO Stage 3, n = 69; WHO Stage 4, n = 20) were contrasted with those of 100 control subjects on measures of attention/concentration, mental flexibility, learning/memory, and motor functioning. RESULTS: Analysis of covariance (ANCOVA) revealed significant group differences on measures of verbal learning and memory, speed of processing, attention and executive functioning between HIV seropositive and seronegative subjects. CONCLUSION: Ugandan patients with HIV demonstrated relative deficits on measures of verbal learning and memory, speed of processing, attention, and executive functioning compared to HIV negative controls. These results from a resource limited region where clades A and D are prevalent are consistent with previous findings in the developed world where clade B predominates
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