117,284 research outputs found
Investigating chemotherapy induced peripheral neuropathy (CIPN) and its treatment, using functional Magnetic Resonance Imaging (fMRI)
No full textBackground
Chemotherapy Induced Peripheral Neuropathy (CIPN) is a debilitating
neuropathy caused by commonly used chemotherapeutics. Clinically, the
problem of CIPN is compounded by difficulties with diagnosis and limited
treatment options. The pathophysiology of CIPN remains elusive, with current
mechanistic postulates focused mainly on the peripheral nervous system.
However, animal and human models of non-CIPN neuropathic conditions have
shown the brain to be central to the development and maintenance of painful
neuropathy. Moreover, evidence suggests that aberrant activity in key regions of
the brain and brainstem could denote individual vulnerability for chronic pain
states. The impact of the brain on CIPN development is unknown. Assessment of
drug efficacy using brain imaging can provide sensitive readouts and is
increasingly used in clinical trials.
Aims
Firstly, to prospectively explore the structure and function of the brain in cancer
patients prior to chemotherapy administration, using functional magnetic
resonance imaging (fMRI), in order to determine whether baseline differences
exist between patients who progress to CIPN as compared to those who do not.
Secondly, to develop a pilot study using fMRI to investigate a topical treatment
for CIPN, in order to assess the feasibility of setting up a study with this kind of
design.
Methods
To address the first aim of this thesis a prospective cohort study (the CIPN fMRI
Study) was developed. Cancer patients scheduled to receive neurotoxic
chemotherapy treatment including oxaliplatin, carboplatin, carbotaxol, or
cisplatin, were recruited from three NHS trusts in Scotland, to undergo a high
resolution (3 tesla) functional MRI scan, at a single time point prior to
commencement of chemotherapy. During the scan structural, resting state and
functional data were collected. Functional data involved the presentation of
punctate stimuli (using a 256mN von Frey filament), above the patients’ right
medial malleolus. While receiving the punctate stimuli, patients viewed images
that had neutral or positive emotional content or a baseline coloured image with
no content. Sample size was based on previously successful pain fMRI studies
and pragmatic estimates. Acute CIPN was defined clinically by common toxicity
criteria as necessitating a chemotherapy dose reduction or cessation. Data were
analysed using FMRIB’s Software Library (FSL) version 5, 2015. Standard data
pre-processing (brain extraction, registration, B0 unwarping, motion correction,
and denosiing with FIX) was carried out. Structural analysis was conducted using
FIRST. Resting state analysis utilised FSL’s MELODIC tool, and a non-parametric
group comparison was made following a dual regression approach. FEAT was
used for both first and second level functional analyses. Group comparisons were
made using a mixed effects analysis (z threshold 2·3 and 2, regions considered
significant at p<0·05, cluster corrected). The group was split by sex to explore
known sex differences in pain processing. To address the second aim of this
thesis, a pilot fMRI randomised controlled trial (MINT3 Study) was designed.
Approvals from ethics and research and development were sought and obtained.
Data collection forms were developed. An fMRI experiment was proposed and a
single pilot scan was conducted and analysed.
Results
30 patients were recruited for the CIPN fMRI study (mean age 60·4 years, [95%
Confidence Interval: 57.4-63.4, 17 women). Two patients had lung cancer, nine
had gynecological malignancies and 18 had colorectal cancer. 17 patients
developed acute CIPN. Structural analysis showed that patients who developed
CIPN had a smaller volume of the Nucleus Accumbens (NAc). Resting state
analysis did not show clear differences between those who developed CIPN and
those who did not. Finally, functional analysis showed that patients who did not
develop CIPN had greater activation in the superior frontal gyrus when viewing
positive emotional images as compared to those who did progress to CIPN.
Region of interest analysis showed that female patients who developed CIPN had
greater activity in their mesencephalic pontine reticular formation (MPRF). Male
patients who progressed to CIPN had decreased activity in their thalamus.
Feasability of the MINT3 study set up and fMRI paradigm was assessed.
Interpretation
Differences in brain structure and function are evident between patients who
developed CIPN and those who did not. Crucially, the regions identified, in
particular the NAc, have been postulated to denote a vulnerability for
progression to pain states. Although the findings need further confirmation they
suggest a paradigm shift in terms of CIPN as a clinical problem. Specifically, it
appears that certain individuals can be considered as having increased risk of
CIPN development prior to chemotherapy administration. This risk relates to the
baseline structure, and function of their brains. Finally, the set up of the MINT3
fMRI study showed that this kind of study design is acceptable in terms of ethical
and R&D approvals and a single healthy volunteer pilot
Going Beyond Counting First Authors in Author Co-citation Analysis
No full textThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Square Dancing with the Stars to Enhance Dynamic Hirschman Linkages?
No full textIn this Presidential Address, the author takes the reader on a reconnaissance of his life and time as a regional scientist. He points out scenery he found scintillating along the way, hoping that some may pick up the banner and chew on a few of the ideas for a while. He suggests a revisit to Albert O. Hirschman’s notion of key sectors and more empirical analysis related to Marcus Berliant’s and Masahisa Fujita’s notion of knowledge creation and transfer.Presidential Address, San Antonio, Texas, March 29, 2014 (53rd Meetings of the Southern Regional Science Association
Appropriate Similarity Measures for Author Cocitation Analysis
No full textWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Letter from unknown writer to Jesse L. Boyce
No full textLetter to Jesse L. Boyce from unknown author (possibly Jack) about the investigation into the powder magazine located in the Grand Canyon. Some personal news is included in the letter such as the writer's marriage to the daughter of C.A. Taylor, former Supervisor of Cochise County
Dispelling the Myths Behind First-author Citation Counts
No full textWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
Sarah L. Blum Author Visit - Warrior Nurse: PTSD and Healing
No full textHear Sarah L. Blum, author of Women Under Fire: Abuse in the Military, discuss her newest book, Warrior Nurse: PTSD and Healing followed by a Q&A and book signing.
Sarah L. Blum is a decorated Vietnam veteran who served as an operating room nurse during the intense fighting of 1967. In recognition of her service, she was awarded the Army Commendation Medal.
Sponsored by CWU Veterans Center and CWU Libraries.https://digitalcommons.cwu.edu/libraryevents/1252/thumbnail.jp
Lillian L. Lambert, Author, Speaker, and Entrepreneur
No full textLillian L. Lambert, Author, Speaker, and Entrepreneu
Letter to Alfred L. Shoemaker, February 10, 1948
No full textA handwritten letter from an unknown author addressed to Alfred L. Shoemaker, dated February 10, 1948. Within, the author discusses the Pennsylvania Dutch word for Ash Wednesday, along with traditions associated with this day.https://digitalcommons.ursinus.edu/shoemaker_documents/1118/thumbnail.jp
Recommended from our members
Emmett L. Bennett, Jr. Offprint Collection
No full textThe scholarly library of Emmett L. Bennett, Jr. compiled in the course of his Editorship of the journal Nestor (founded in 1957). The collection includes scholarly publications (offprints) and manuscripts sent by prospective authors to Dr. Bennett. Includes a Finding Aid (PDF and Word) and Catalog (an Excel document for each of two record groups: offprints collected up to 1995, and offprints collected from 1995-2011). Both the Finding Aid and Catalog are provided to facilitate researchers' searches for offprints by author, title, journal, year, and subject.Classic
- …
