Turning Blood into Liver
Richard K. Burt, Alberto M. Marmont in Stem Cell Therapy for Autoimmune Disease, 2019
The question of directionality was convincingly settled by three dimensional analysis. First, in the same study that demonstrated the combined phenotype of early human hepatoblasts, the presence of isolated oval cells, positive for biliary-type cytokeratins, in the hepatic parenchyma were identified in normal human livers.14 When these cells were studied in serial sections, they were found to be cross-sections of the canals of Hering.20 The canals had traditionally been thought to extend from the terminal branches of the bile ducts within the portal tracts just to points of connection to the hepatocyte canalicular system in the limiting plate of hepatocytes, just at the margins of the portal tract stroma. This 3-dimensional analysis, however, showed that they extended beyond the limiting plate, sometimes extending as much as a third of the way into the hepatic lobule. Three dimensional examination of a case of massive hepatic necrosis secondary to acetaminophen injury then showed that the ductular reaction actually comprised a highly proliferative,71 greatly complex, arborizing expansion of the canals of Hering, thus confirming that the canal of Hering “is comprised of, or at least harbors bipotent hepatic progenitor cells in humans.”
Understanding content and form in interpreter-mediated medical communication
Claudia V. Angelelli in Healthcare Interpreting Explained, 2019
As we discussed above, in addition to content, messages have form. We study form by focusing on how a message is uttered by a participant and how it is delivered by the interpreter to the other participant. In the end, the other participant gets a blend of forms of the original utterance and the interpreted one. The interpreter may or may not be familiar with the ways of speaking of either the provider or the patient. The interpreter may or may not share a community of discourse with either of them. However, because one works for two parties, one needs to pay attention to the ways of speaking of both. This is an additional difficulty presented to the interpreter in healthcare encounters. In part this difficulty can be explained because, unlike other situations where interpreters work (e.g. a conference, a court hearing), in patient-provider encounters there is dialogue. The interpreter works in a mode that is referred to as dialogue interpreting (Cirillo and Niemants 2017). This means that the interpreter follows two parties (not just one) who are directly speaking to each other and interacting. When performing dialogue interpreting, the interpreter works into and out of the two languages. So, in addition to the element of dialogue and interaction, there is the element of language bi-directionality.
Synthetic and Physiological IVIM Complexity
Denis Le Bihan, Mami Iima, Christian Federau, Eric E. Sigmund in Intravoxel Incoherent Motion (IVIM) MRI, 2018
As the evidence base grows, however, it has become clear that the manifestations of IVIM differentiate themselves in organ- and pathology-specific ways. The tissue fraction displaying pseudodiffusion varies greatly, necessitating adaptations of acquisition and analysis. In some cases, the microcirculation is isotropic, while in others, it shows directionality in the structure and/or flow within the flow compartment. The active processes captured in the IVIM effect are also affected by such stimuli as an exercise challenge, which has motivated protocols capturing binary or dynamic changes from the baseline. In short, the occurrences of IVIM have been recognized to require treatment beyond the static isotropic model. Just as the application of structure-based diffusion- weighted imaging contrast has evolved from isotropic to anisotropic to higher and higher levels of complexity—with associated higher biological specificity—so too can we expect that a refinement of the IVIM signature to reflect more complex scenarios will amplify diagnostic potential in those situations.
Exploring life stressors, depression, and coping strategies in college students
Published in Journal of American College Health, 2022
Kassie R. Terrell, Bridget R. Stanton, Hanadi Y. Hamadi, Julie W. Merten, Nathan Quinn
To address a limitation of the current study, it is recommended that future researchers more directly assess for directionality among these variables. Conducting longitudinal studies and studies using structural equation modeling could aid in this effort. It would also be worthwhile for future researchers to collect data about campus culture and environments (eg, number of counselors on campus, information about mental health programming) and explore multilevel modeling, wherein the students are nested within the school. This type of research could help identify environmental factors that catalyze or mitigate the risk of depressive symptoms for college students who experience stressful life events. Lastly, while researchers must be knowledgeable of risk factors and maladaptive coping strategies that exacerbate depression, it is also necessary to explore protective factors associated with resiliency.
Longitudinal gut microbiome changes in alcohol use disorder are influenced by abstinence and drinking quantity
Published in Gut Microbes, 2020
Nancy J. Ames, Jennifer J. Barb, Kornel Schuebel, Sarah Mudra, Brianna K. Meeks, Ralph Thadeus S. Tuason, Alyssa T. Brooks, Narjis Kazmi, Shanna Yang, Kelly Ratteree, Nancy Diazgranados, Michael Krumlauf, Gwenyth R. Wallen, David Goldman
The space defined by the first three PCs encompassed nearly half (46.7%) of the total variance in microbiome representation. The first three PCs representing such large variability of the entire data matrix are likely to be driven in parts, by the severe exposure AUD patients received and changes subsequent to abstinence. Individuals who drank more heavily showed larger longitudinal shifts as evidenced by the size of ellipses in PC space. Irrespective of drinking amount, varying the ellipsis sizes around PC indicate individual-specific gut microbiota. Differences in directionality of vectors underscore the impact of individual variation (Figure 7(b)). Within subjects, both LHD and VHD patients are most divergent immediately following abstinence and as time goes on their microbiomes tend to stabilize.
Reassessing the Ethics of Molecular HIV Surveillance in the Era of Cluster Detection and Response: Toward HIV Data Justice
Published in The American Journal of Bioethics, 2020
Stephen Molldrem, Anthony K J Smith
The utilization of phylogenetic analyses of HIV genetic sequence data in criminal proceedings where HIV transmission is alleged is a recognized problem (Barré-Sinoussi et al. 2018; Galletly et al. 2019; UNAIDS 2013). A key issue in criminal contexts is whether phylogenetic analysis can be utilized to discern directionality of transmission (i.e. to prove that person A transmitted HIV to person B). A consensus across the ethical literature is that HIV phylogenetic analysis cannot be used to infer directionality (Coltart et al. 2018; Mutenherwa et al. 2019). However, as we explore in case two, some practitioners argue that directionality can be inferred. Similarly, Mutenherwa et al.’s (2019) participants were concerned about MHS being used to identify “high HIV transmitters” and marginalized subpopulations. As we explore in case three, this has occurred, and some researchers encourage the use of phylogenetic software for “[f]inding likely transmitters in a large population cohort” (Wymant et al. 2018, 728). From an ethical and methodological perspective, the distinction between whether directionality cannot or should not be inferred using molecular data is not clear.
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