13 research outputs found
Anatomical evidence for volume transmission in the dorsal vagal complex of the rat
Injection of either calcitonin gene-related peptide (CGRP) or substance P (SP)
into the cerebrospinal fluid or dorsal vagal complex (DVC) of the rat has an effect on
gastric function via a vagally-dependent mechanism. These effects are both slow in onset
and of prolonged duration, characteristics of non-synaptic events. Although these
peptides have been previously detected within the DVC, the anatomical basis for their
effects has remained unclear.
In order to examine the possibility that these peptides act via a non-synaptic,
volume transmission mechanism within the rat DVC, a combination of retrograde tracing,
immunocytochemistry, confocal microscopy and 3-D reconstruction techniques were used
to investigate the spatial association between nerve fibres immunoreactive for both CGRP
and SP, the substance P receptor (NK-lr) and identified gastric efferent neurons within
this region.
In 3-D reconstructions, it was found that the majority of nerve fibres containing
either SP- or CGRP-IR surrounded identified gastric efferent neurons without making
contact with the membrane of these cells. While most of the CGRP-IR fibres were
preferentially associated with the dendrites of retrogradely-labelled neurons around the
level of the obex, SP-IR fibres surrounded all surfaces of these cells at all levels of the
DVC.
The somatic membrane of a subpopulation of gastric efferent neurons (7%) was
labelled with NK-lr-IR. In addition, NK-lr-IR was localized to nerve fibres, mainly in
the rostral DVC. NK-lr-IR covered almost the entire membrane of some DMV neurons,
with the highest density of receptors localized to the dendrites.
The distribution of neutral endopeptidase 24.11 (NEP), the principle cleavage
enzyme for SP within the CNS, was compared to that of SP-IR, NK-lr-IR and
retrogradely-labelled gastric efferent neurons within this region. The enzyme was not
associated with vagal neurons or fibres at any level of the DVC, but rather was localized
to components of the blood-brain barrier.
In conclusion, the small proportion of neuropeptide-IR nerve fibres that made
direct contact with identified neurons, the non-synaptic localization of NK-lr-IR and the
absence of NEP-IR associated with identified neurons provide anatomical evidence in
support of neural communication via volume transmission within the rat DVC.Medicine, Faculty ofCellular and Physiological Sciences, Department ofGraduat
Mobile microscopy as a screening tool for oral cancer in India: A pilot study.
Oral cancer is the most common type of cancer among men in India and other countries in South Asia. Late diagnosis contributes significantly to this mortality, highlighting the need for effective and specific point-of-care diagnostic tools. The same regions with high prevalence of oral cancer have seen extensive growth in mobile phone infrastructure, which enables widespread access to telemedicine services. In this work, we describe the evaluation of an automated tablet-based mobile microscope as an adjunct for telemedicine-based oral cancer screening in India. Brush biopsy, a minimally invasive sampling technique was combined with a simplified staining protocol and a tablet-based mobile microscope to facilitate local collection of digital images and remote evaluation of the images by clinicians. The tablet-based mobile microscope (CellScope device) combines an iPad Mini with collection optics, LED illumination and Bluetooth-controlled motors to scan a slide specimen and capture high-resolution images of stained brush biopsy samples. Researchers at the Mazumdar Shaw Medical Foundation (MSMF) in Bangalore, India used the instrument to collect and send randomly selected images of each slide for telepathology review. Evaluation of the concordance between gold standard histology, conventional microscopy cytology, and remote pathologist review of the images was performed as part of a pilot study of mobile microscopy as a screening tool for oral cancer. Results indicated that the instrument successfully collected images of sufficient quality to enable remote diagnoses that show concordance with existing techniques. Further studies will evaluate the effectiveness of oral cancer screening with mobile microscopy by minimally trained technicians in low-resource settings
A smart tele-cytology point-of-care platform for oral cancer screening.
Early detection of oral cancer necessitates a minimally invasive, tissue-specific diagnostic tool that facilitates screening/surveillance. Brush biopsy, though minimally invasive, demands skilled cyto-pathologist expertise. In this study, we explored the clinical utility/efficacy of a tele-cytology system in combination with Artificial Neural Network (ANN) based risk-stratification model for early detection of oral potentially malignant (OPML)/malignant lesion. A portable, automated tablet-based tele-cytology platform capable of digitization of cytology slides was evaluated for its efficacy in the detection of OPML/malignant lesions (n = 82) in comparison with conventional cytology and histology. Then, an image pre-processing algorithm was established to segregate cells, ANN was trained with images (n = 11,981) and a risk-stratification model developed. The specificity, sensitivity and accuracy of platform/ stratification model were computed, and agreement was examined using Kappa statistics. The tele-cytology platform, Cellscope, showed an overall accuracy of 84-86% with no difference between tele-cytology and conventional cytology in detection of oral lesions (kappa, 0.67-0.72). However, OPML could be detected with low sensitivity (18%) in accordance with the limitations of conventional cytology. The integration of image processing and development of an ANN-based risk stratification model improved the detection sensitivity of malignant lesions (93%) and high grade OPML (73%), thereby increasing the overall accuracy by 30%. Tele-cytology integrated with the risk stratification model, a novel strategy established in this study, can be an invaluable Point-of-Care (PoC) tool for early detection/screening in oral cancer. This study hence establishes the applicability of tele-cytology for accurate, remote diagnosis and use of automated ANN-based analysis in improving its efficacy
Screenshots of the CellScope server user interface.
<p>(A) Screenshot of the CellScope server (web portal interface) showing the list of patients whose diagnosis has been carried out. Color-coding of records was used to indicate the status of the samples (i.e. diagnostic result provided, awaiting review, sample rejected, etc.) (B) Screenshot of server interface showing CellScope images acquired from a patient sample. Note the thumbnail panel on the left showing thumbnails of all images captured for that patient sample and a magnified image of the selected image in the center/right. Selected regions of interest (indicated by light blue rectangles which could be drawn by the pathologists using tools provided in the interface) are overlaid on the image. (C) Screenshot of the server interface showing a pop-up window containing various cellular features which could be used by the pathologist to annotate the selected region of interest. A free-text box in this window allowed the pathologists to enter additional comments, if necessary.</p
Sensitivity and specificity of the automated CellScope vs. cytology.
<p>Sensitivity and specificity of the automated CellScope vs. cytology.</p
Process for encoding/decoding of patient information and samples.
<p>Process for encoding/decoding of patient information and samples.</p
Sensitivity and specificity of conventional cytology vs. histology.
<p>Sensitivity and specificity of conventional cytology vs. histology.</p
Clinical and pathological diagnosis of patients.
<p>Clinical and pathological diagnosis of patients.</p
Patient demographics and related clinical parameters of the study.
<p>Patient demographics and related clinical parameters of the study.</p