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9
result(s) for
"Fleming, R. Y. Declan"
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Three-Dimensional Regeneration of Patient-Derived Intestinal Organoid Epithelium in a Physiodynamic Mucosal Interface-on-a-Chip
by
Eckhardt, S. Gail
,
Koh, Domin
,
Koh, Hong
in
Biomechanics
,
Colorectal cancer
,
Computational fluid dynamics
2020
The regeneration of the mucosal interface of the human intestine is critical in the host–gut microbiome crosstalk associated with gastrointestinal diseases. The biopsy-derived intestinal organoids provide genetic information of patients with physiological cytodifferentiation. However, the enclosed lumen and static culture condition substantially limit the utility of patient-derived organoids for microbiome-associated disease modeling. Here, we report a patient-specific three-dimensional (3D) physiodynamic mucosal interface-on-a-chip (PMI Chip) that provides a microphysiological intestinal milieu under defined biomechanics. The real-time imaging and computational simulation of the PMI Chip verified the recapitulation of non-linear luminal and microvascular flow that simulates the hydrodynamics in a living human gut. The multiaxial deformations in a convoluted microchannel not only induced dynamic cell strains but also enhanced particle mixing in the lumen microchannel. Under this physiodynamic condition, an organoid-derived epithelium obtained from the patients diagnosed with Crohn’s disease, ulcerative colitis, or colorectal cancer independently formed 3D epithelial layers with disease-specific differentiations. Moreover, co-culture with the human fecal microbiome in an anoxic–oxic interface resulted in the formation of stochastic microcolonies without a loss of epithelial barrier function. We envision that the patient-specific PMI Chip that conveys genetic, epigenetic, and environmental factors of individual patients will potentially demonstrate the pathophysiological dynamics and complex host–microbiome crosstalk to target a patient-specific disease modeling.
Journal Article
Laser brain cancer surgery in a xenograft model guided by optical coherence tomography
2019
Higher precision surgical devices are needed for tumor resections near critical brain structures. The goal of this study is to demonstrate feasibility of a system capable of precise and bloodless tumor ablation. An image-guided laser surgical system is presented for excision of brain tumors
in a murine xenograft model. The system combines optical coherence tomography (OCT) guidance with surgical lasers for high-precision tumor ablation (Er:YAG) and microcirculation coagulation (Thulium (Tm) fiber laser).
A fluorescent human glioblastoma cell line was injected into mice and allowed to grow four weeks. Craniotomies were performed and tumors were imaged with confocal fluorescence microscopy. The mice were subsequently OCT imaged prior, during and after laser coagulation and/or ablation. The prior OCT images were used to compute three-dimensional tumor margin and angiography images, which guided the coagulation and ablation steps. Histology of the treated regions was then compared to post-treatment OCT images.
Tumor sizing based on OCT margin detection matched histology to within experimental error. Although fluorescence microscopy imaging showed the tumors were collocated with OCT imaging, margin assessment using confocal microscopy failed to see the extent of the tumor beyond ~ 250 µm in depth, as verified by OCT and histology. The two-laser approach to surgery utilizing Tm wavelength for coagulation and Er:YAG for ablation yielded bloodless resection of tumor regions with minimal residual damage as seen in histology.
Precise and bloodless tumor resection under OCT image guidance is demonstrated in the murine xenograft brain cancer model. Tumor margins and vasculature are accurately made visible without need for exogenous contrast agents.
Journal Article
The Enhanced Recovery After Surgery (ERAS) Elements that Most Greatly Impact Length of Stay and Readmission
2021
Background
Enhanced recovery after surgery (ERAS) protocols have been shown to decrease length of stay (LOS) and improve patient outcomes in a wide variety of surgical fields; however, barriers exist preventing the implementation of all elements. We hypothesize that a subset of ERAS elements are most influential on LOS and readmission following colorectal surgery.
Study Design
A retrospective review of 840 patients was performed and their compliance with 24 ERAS components evaluated. Two independent machine-learning statistical algorithms were employed to determine which subset of ERAS elements was most impactful on LOS <3 days and hospital readmission.
Results
Increasing compliance with ERAS elements had an inverse linear relationship with LOS. Open (vs minimally invasive) surgery was associated with increased LOS. Early mobilization and multimodal pain management are the elements most protective against increased LOS. Readmissions increase with the number of morphine milligram equivalents (MME)/day. The subset of patients who underwent minimally invasive procedures, had multimodal pain control, and less than 16 MME per day were least likely (23%) to have >3-day LOS. Those patients who underwent an open procedure with less than 15 ERAS elements completed were most likely (84%) to have >3-day LOS.
Conclusion
While increasing compliance with ERAS protocols and minimally invasive procedures decrease LOS and readmission overall, a subset of components—multimodal pain control, limited opioid use, and early mobilization—was most associated with decreased LOS and readmission. This study provides guidance on which ERAS elements should be emphasized.
Journal Article
A Mobile App With Multimodality Prehabilitation Programs for Patients Awaiting Elective Surgery: Development and Usability Study
2021
Complying with a prehabilitation program is difficult for patients who will undergo surgery, owing to transportation challenges and a limited intervention time window. Mobile health (mHealth) using smartphone apps has the potential to remove barriers and improve the effectiveness of prehabilitation.
This study aimed to develop a mobile app as a tool for facilitating a multidisciplinary prehabilitation protocol involving blood flow restriction training and sport nutrition supplementation.
The app was developed using \"Appy Pie,\" a noncoding app development platform. The development process included three stages: (1) determination of principles and requirements of the app through prehabilitation research team meetings; (2) app prototype design using the Appy Pie platform; and (3) app evaluation by clinicians and exercise and fitness specialists, technical professionals from Appy Pie, and non-team-member users.
We developed a prototype of the app with the core focus on a multidisciplinary prehabilitation program with accessory features to improve engagement and adherence to the mHealth intervention as well as research-focused features to evaluate the effects of the program on frailty status, health-related quality of life, and anxiety level among patients awaiting elective surgery. Evaluations by research members and random users (n=8) were consistently positive.
This mobile app has great potential for improving and evaluating the effectiveness of the multidisciplinary prehabilitation intervention in the format of mHealth in future.
Journal Article
Effectiveness of mastectomy by response to induction chemotherapy for control in inflammatory breast carcinoma
1997
Controversy exists as to the treatment regimen necessary to best provide optimal local control for inflammatory breast carcinoma (IBC). This study was conducted to determine if mastectomy combined with radiotherapy offered any advantages over radiotherapy alone in patients with IBC who had been treated with doxorubicin-based combination chemotherapy.
A retrospective review of 178 women treated for IBC on doxorubicin-based multimodality therapy protocols between January 1974 and September 1993 was performed. Clinical and histologic response to treatment, time to local recurrence, survival, and ultimate control of local disease were analyzed. Kaplan-Meier analysis was used to examine survival and relapse times, and Fisher's exact test was used to test differences in treatment outcomes. Significance was determined at p < or = 0.05.
Median follow-up was 89 months (range 22 to 223 months). Locoregional disease persisted in seven patients and recurred in 44 patients who had been rendered disease free at a median time of 10 months. The mortality rate after a local recurrence (LR) was 98%, and all patients but one with LR developed systemic metastases. Response to induction chemotherapy influenced the incidence of LR, and the amount of residual disease found on histologic examination of mastectomy specimens was highly prognostic for local failure. Patients who underwent mastectomy in addition to radiotherapy had a lower incidence of LR than did patients who received radiotherapy alone (16.3% vs. 35.7%, p = 0.015).
The addition of mastectomy to combination chemotherapy plus radiotherapy improved local control in patients with IBC. The addition of mastectomy to chemotherapy plus radiotherapy improved distant disease-free and overall survival in patients with a clinical complete or partial response to induction chemotherapy. Patients who had no significant response to induction chemotherapy received no survival or local disease-control benefit from the addition of mastectomy to their treatment regimen. These patients should be considered for entry into clinical trials of new treatment regimens.
Journal Article
Overexpression of focal adhesion kinase (p125FAK) in human colorectal carcinoma liver metastases: Independence from c-src or c-yes activation
by
Curley, Steven A.
,
Fleming, R. Y. Declan
,
Gallick, Gary E.
in
Biomarkers, Tumor
,
Carcinoma - enzymology
,
Carcinoma - pathology
1997
p125FAK, pp60C-src, and pp62c-yes are protein tyrosine kinases that function in signaling pathways regulating cell adhesion, migration, and growth. The expression and tyrosine kinase activities of pp60c-src and pp62c-yes, and the expression of p125FAK are increased in colorectal tumor metastases relative to normal mucosa. This study investigates whether differences in the activation of pp60c-src and pp62c-yes in colorectal liver metastases correlated with differences in p125FAK expression and whether prognostic significance could be demonstrated from the extent of expression of p125FAK in metastases.
Activities of pp60c-src and pp62c-yes were measured in the immune complex kinase assay. Relative levels of p125FAK, pp60c-src, and pp62c-yes were determined by immunoblotting.
p125FAK was overexpressed in 29 of 30 colorectal cancer liver metastases (range of two-to 195-fold increase compared with normal mucosa). The degree of overexpression of p125FAK was not a significant prognostic factor in survival. A differential activation of pp60c-src and pp62c-yes in colorectal carcinoma liver metastases was observed. However, overexpression of p125FAK was observed in metastases with either pp60c-src or pp62c-yes activated in colorectal carcinoma liver metastases.
p125FAK overexpression appears to be a marker present in colorectal cancer cells with a metastatic phenotype. Furthermore, p125FAK overexpression is independent of pp60c-src or pp62c-yes activation in human colorectal carcinoma liver metastases.
Journal Article
Insulin action on muscle protein kinetics and amino acid transport during recovery after resistance exercise
1999
Insulin action on muscle protein kinetics and amino acid transport during recovery after resistance exercise.
G Biolo ,
B D Williams ,
R Y Fleming and
R R Wolfe
Department of Internal Medicine, University of Texas Medical Branch, and the Shriners Burns Hospital, Galveston, USA.
Abstract
We have determined the individual and combined effects of insulin and prior exercise on leg muscle protein synthesis and degradation,
amino acid transport, glucose uptake, and alanine metabolism. Normal volunteers were studied in the postabsorptive state at
rest and about 3 h after a heavy leg resistance exercise routine. The leg arteriovenous balance technique was used in combination
with stable isotopic tracers of amino acids and biopsies of the vastus lateralis muscle. Insulin was infused into a femoral
artery to increase the leg insulin concentrations to high physiologic levels without substantively affecting the whole-body
level. Protein synthesis and degradation were determined as rates of intramuscular phenylalanine utilization and appearance,
and muscle fractional synthetic rate (FSR) was also determined. Leg blood flow was greater after exercise than at rest (P<0.05).
Insulin accelerated blood flow at rest but not after exercise (P<0.05). The rates of protein synthesis and degradation were
greater during the postexercise recovery (65+/-10 and 74+/-10 nmol x min(-1) x 100 ml(-1) leg volume, respectively) than at
rest (30+/-7 and 46+/-8 nmol x min(-1) x 100 ml(-1) leg volume, respectively; P<0.05). Insulin infusion increased protein
synthesis at rest (51+/-4 nmol x min(-1) x 100 ml(-1) leg volume) but not during the postexercise recovery (64+/-9 nmol x
min(-1) x 100 ml(-1) leg volume; P<0.05). Insulin infusion at rest did not change the rate of protein degradation (48+/-3
nmol x min(-1) 100 ml(-1) leg volume). In contrast, insulin infusion after exercise significantly decreased the rate of protein
degradation (52+/-9 nmol x min(-1) x 100 ml(-1) leg volume). The insulin stimulatory effects on inward alanine transport and
glucose uptake were three times greater during the postexercise recovery than at rest (P<0.05). In contrast, the insulin effects
on phenylalanine, leucine, and lysine transport were similar at rest and after exercise. In conclusion, the ability of insulin
to stimulate glucose uptake and alanine transport and to suppress protein degradation in skeletal muscle is increased after
resistance exercise. Decreased amino acid availability may limit the stimulatory effect of insulin on muscle protein synthesis
after exercise.
Journal Article
The safety of helium for abdominal insufflation
1997
A search for alternative methods of abdominal insufflation has been prompted by the fact that CO2 insufflation may cause acidosis, decreased cardiac output, increased systemic vascular resistance, and increased cardiac filling pressures. This study evaluates the safety and the cardiopulmonary effects of helium abdominal insufflation (HAI).
Thirteen ASA class III and IV patients undergoing laparoscopic procedures were studied in a prospective, nonrandomized protocol using HAI. Cardiopulmonary parameters were measured before and after anesthetic induction and every 30 min during HAI. Abdominal insufflation pressure was initially 10 mmHg and was increased to 15 mmHg after 30 min. All measurements were repeated 15 min after deflation of the abdomen. Changes were evaluated by ANOVA.
No significant cardiopulmonary complications were observed. No patient developed hypercarbia or acidosis. Peak inspiratory pressure increased with HAI from 20 +/- 1 to 34 +/- 2 cm H2O (p < 0.0001). Cardiac index decreased (3.35 +/- 0.19 vs 2.37 +/- 0.19 l/min/m2; p = 0.0303) and systemic vascular resistance increased (1,123 +/- 66 vs 1,406 +/- 126 dyne . s/cm5; p = 0.0512) while cardiac filling pressures increased with insufflation to 15 mmHg.
Minimal cardiac and pulmonary aberrations were observed. Helium was safe for abdominal insufflation and may be the insufflating agent of choice in patients with significant cardiopulmonary disease.
Journal Article
cDNA Arrays and Immunohistochemistry Identification of CD10/CALLA Expression in Hepatocellular Carcinoma
2001
The histological diagnosis of hepatocellular carcinoma (HCC) can be complicated by difficulty in differentiation from cholangiocarcinoma and metastatic carcinoma. Immunohistochemical stains currently in use are suboptimal in terms of specificity and sensitivity. Using cDNA array analysis for differential gene expression, we demonstrated a significant increase in mRNA expression level of CD10/CALLA, a type 2 cell-surface metalloproteinase, in HCC, which was subsequently confirmed by reverse transcriptase-polymerase chain reaction and Western blotting analysis. To test the possibility of using CD10/CALLA as a diagnostic marker for HCC, various intrahepatic tumors were studied immunohistochemically using a monoclonal antibody for CD10. A characteristic canalicular-staining pattern was observed in normal hepatocytes and at the apical surface of bile duct epithelial cells. The canalicular expression of CD10 was identified in 9 of 15 HCCs examined (60%), whereas 10 cholangiocarcinomas and 8 of 9 metastatic carcinomas lacked this staining. In three of the six HCCs negative for CD10, the surrounding nonneoplastic liver tissue was also negative, suggesting fixation-associated loss of immunoreactivity. Six HCCs had stronger CD10 staining in tumor cells when compared to the surrounding nonneoplastic tissue. Three cases of benign bile duct adenomas also expressed CD10 at the luminal aspect. One of the MCs showed a diffuse, cytoplasmic staining for CD10, a pattern readily distinguishable from that of HCC. A panel of other immunohistochemical markers were also studied for comparison, including polyclonal anti-carcinoembryonic antigen, cytokeratin (CK) 7, CK20, and α-fetoprotein. Our results demonstrate that cDNA arrays can be effectively used to identify new diagnostic markers, and that CD10 is a reliable marker for identifying HCC, particularly when used in conjunction with a panel of immunohistochemical markers (polyclonal anti-carcinoembryonic antigen, CK7, CK20, and α-fetoprotein) and in the distinction from cholangiocarcinoma.
Journal Article