310 research outputs found
Microfluidic particle tracking technique towards white blood cell subtype counting and serum protein quantification
No full textMicrofluidic technologies have gained wide acceptance in the past decade as diagnostics tools in clinical setting world-wide. This is primarily due to the fact that microfluidic technologies enable rapid, quantitative assays from small amount of physiological sample in an easy-to-use, portable platform. In this work, we will describe a microfluidic technique that can be built upon to count white blood cell subtypes or serum protein from a drop of blood. Traditionally, researchers have counted white blood cell subtypes by capturing them. However, an elegant and more accurate way to do the same is by exploiting the transitory interactions between the antigen on the surface of the cell and a cognate antibody. Cells expressing the antigen of interest will take longer to traverse a microchannel which has been coated with a cognate antibody compared to the cells which don't express that antigen. To our knowledge, no microfluidic assay exists which can rapidly count cells using this principle. Towards this end, we have developed a repeatable experimental technique to control the transit time and the order of particles in a microchannel. To least affect the uniformity of transit time, we have also optimized the geometry of pillars in the microchannel on which antibodies are functionalized.Submission published under a 24 month embargo labeled 'Closed Access', the embargo will last until 2018-08-01The student, Tanmay Ghonge, accepted the attached license on 2016-07-20 at 20:20.The student, Tanmay Ghonge, submitted this Thesis for approval on 2016-07-20 at 20:22.This Thesis was approved for publication on 2016-07-22 at 15:07.DSpace SAF Submission Ingestion Package generated from Vireo submission #10043 on 2016-11-10 at 12:21:02Made available in DSpace on 2016-11-10T18:27:09Z (GMT). No. of bitstreams: 2
GHONGE-THESIS-2016.pdf: 2007682 bytes, checksum: 2e84b6da47c9ce69ad66e0b45f92a31f (MD5)
LICENSE.txt: 4210 bytes, checksum: 80de1a9885d9f902620d9b6cd84a0e36 (MD5)
Previous issue date: 2016-07-22Embargo set by: Seth Robbins for item 95295
Lift date: 2018-11-10T18:28:02Z
Reason: Author requested closed access (OA after 2yrs) in Vireo ETD systemLimited Restriction Lifted for Item 95295 on 2018-11-11T10:15:11Z
Left renal vein hypertension as a cause of occult hematuria: Multi-detector computed tomography demonstration
No full textPoint-of-care microfluidic assays for measuring expression level of antigen on blood cells
No full textElevated expression of a membrane protein CD64 on neutrophils is linked with the onset of sepsis, a life-threatening syndrome that contributes to millions of deaths annually worldwide. The survival rate of septic patients falls rapidly every hour the appropriate medication is delayed. Therefore, automated and periodic measurements of CD64 expression (nCD64) at the patient’s bedside could lead to timely medical intervention, thereby saving lives and billions of dollars. Gold standard assays for measuring nCD64, such as flow cytometry, require manual sample preparation and long incubation times. For point-of-care applications, however, an assay should be able to measure nCD64 with little to no sample preparation.
This dissertation addresses the need by investigating portable, point-of-care platforms for measuring nCD64 from whole blood without any off-chip sample preparation. Our first platform is an electrical biosensor that measures nCD64 by measuring the fraction of immunologically captured cells expressing CD64. It consists of a capture chamber, for immunologically capturing cells and microfluidic coulter counters at its entrance and exit. In our study, we found that the fraction of cells expressing CD64 correlates linearly with nCD64. For our study, we optimized the geometry of the capture chamber and the coulter counters from the first principles of fluid mechanics and electrostatics respectively. This biosensor can produce a readout of nCD64 starting from just 10 μL of blood in 10 mins. Although this technique does not require off-chip sample preparation, red blood cells have to be lysed on-chip so that white blood cells can be counted by the electrical counters.
Lysing red blood cells on-chip adds a step which requires multiple pumps running in parallel. Ideally, the technique should be able to measure nCD64 without red blood cell lysis. Towards that, we have developed an optical, microfluidic cell capture assay that works from whole blood. We demonstrate the proof-of-concept of this assay by measuring the density of biotin molecules on beads. We injected beads in a capture chamber that is functionalized with neutravidin. Beads that have a higher density of travel, on average, shorter distances in the chamber before they get captured compared to the beads with a lower density of biotin. We developed a statistical model to extract the probability of capture (ε) per interaction with a pillar from the spatial distribution of beads in the channel. ε is found to be linearly proportional to the surface density of biotin.
We expanded this optical technique to measure the nCD64 on neutrophils. One μL blood whole blood is injected in a microfluidic channel consisting of a capture chamber functionalized with anti-CD64 antibodies. As was the case with beads, the immunologically captured have a distinct spatial signature of capture depending on the CD64 expression level. Samples with higher CD64 expression travel, on average, a shorter distance in the channel. Using the same statistical model used to quantify biotin density on beads, we quantified CD64 expression on neutrophils. To make this technique easily translatable to a point-of-care device, we assembled a smartphone-imaging set-up to replace bulky microscopes. Our smartphone microscope can measure CD64 from whole blood without the need for any sample preparation in about 20 mins. We believe that deploying this technology in hospitals could save millions of lives worldwide.Submission published under a 24 month embargo labeled 'Closed Access', the embargo will last until 2021-05-01The student, Tanmay Ghonge, accepted the attached license on 2019-02-19 at 21:50.The student, Tanmay Ghonge, submitted this Dissertation for approval on 2019-02-19 at 21:56.This Dissertation was approved for publication on 2019-02-28 at 09:39.DSpace SAF Submission Ingestion Package generated from Vireo submission #13396 on 2019-08-22 at 16:19:57Made available in DSpace on 2019-08-23T20:44:32Z (GMT). No. of bitstreams: 4
GHONGE-DISSERTATION-2019.pdf: 6173436 bytes, checksum: e019c78e550dfe824345201dcfadce00 (MD5)
Supplementary movie 1.mp4: 2673428 bytes, checksum: 817416641bad1a3ab3e06c0ebad7072d (MD5)
Supplementary movie 2.mp4: 1779519 bytes, checksum: 057a1fb688c9c39fe8441ab6723ca551 (MD5)
LICENSE.txt: 4210 bytes, checksum: 9bc36e1e230870dbc2ce23553dd18cc1 (MD5)
Previous issue date: 2019-02-28Embargo set by: Seth Robbins for item 112254
Lift date: 2021-08-23T20:44:50Z
Reason: Author requested closed access (OA after 2yrs) in Vireo ETD systemEmbargo set by: Seth Robbins for item 112254
Lift date: 2021-08-23T20:46:41Z
Reason: Author requested closed access (OA after 2yrs) in Vireo ETD systemEmbargo set by: Seth Robbins for item 112254
Lift date: 2021-08-23T20:47:38Z
Reason: Author requested closed access (OA after 2yrs) in Vireo ETD systemEmbargo set by: Seth Robbins for item 112254
Lift date: 2021-08-23T20:48:32Z
Reason: Author requested closed access (OA after 2yrs) in Vireo ETD systemLimited Restriction Lifted for Item 112254 on 2021-08-24T09:15:20Z
Tubercular arthritis of knee: Navigating the diagnostic dilemma
No full textThe illustrated case of 48 years male highlights the challenges in clinical diagnosis of tubercular arthritis. Multi-modality imaging of knee joint and confirmation with synovial fluid aspiration and biopsy allowed prompt and accurate diagnosis
Isolated absence of right pulmonary artery: Radiographic and multi-detector CT demonstration
No full textMinimum-intensity projection images in high-resolution computed tomography lung: Technology update
No full textChest physicians need to be aware about MinIP images, as these are increasingly being used for the evaluation of a wide range of lung diseases in HRCT study of lungs. MinIP images highlight the areas with reduced CT attenuation in the lung parenchyma. This allows prompt and early diagnosis of cystic lung diseases or airway, vascular or parenchymal disorders, which manifest with hypoattenuation, mosaic attenuation or air trapping. MiniP images are therefore useful for accurate pre-operative planning and disease monitoring
Zinner syndrome: A unique triad of mesonephric duct abnormalities as an unusual cause of urinary symptoms in late adolescence
No full textThe present article reports a triad of right renal agenesis, ipsilateral seminal vesicle cyst, and ejaculatory duct obstruction (Zinner syndrome) in a 19-year boy who presented with urinary symptoms. A detailed review of the relevant literature is also presented
Computed tomography and magnetic resonance imaging in the evaluation of pelvic peritoneal adhesions: What radiologists need to know?
No full textPelvic peritoneal adhesions constitute an important cause of concern which affects the life of millions of people worldwide due to complications like abdominal pain, bowel obstruction and infertility along with challenges in surgical exploration. Precise pre-operative diagnosis of the presence and extent of peritoneal adhesions is of great clinical and surgical importance. Diagnostic laparoscopy to detect peritoneal adhesions may itself lead to formation of adhesions. Routine CT and MRI studies are therefore useful non-invasive modalities to achieve this objective. This review article provides a brief background about the causation and patho-physiology of peritoneal adhesions. The article also addresses the range of clinical presentations in these patients, mainly from the gynecologic perspective. This article provides an illustrative review of CT and MRI findings with laparoscopic correlation. A new ′imaging-based grading system′ for pre-operative quantification of the burden of peritoneal adhesions is also proposed. Despite practical challenges in accurate pre-operative diagnosis of peritoneal adhesions on imaging, detection of peritoneal adhesions is certainly feasible on routine CT and MRI scans and should be an integral part of image interpretation
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