Sonlee West - Academia.edu (original) (raw)

Papers by Sonlee West

Journal of Surgical Research, 2003

Journal of Surgical Research, 2014

Background: The purpose of this study was to examine the presentation of diverticulitis at an urb... more Background: The purpose of this study was to examine the presentation of diverticulitis at an urban county hospital serving predominantly indigent patients and to analyze the differences, if any, in presentation and treatment in younger patients. Methods: A retrospective review of medical records from 1995 to 2001 was performed at a single institution to identify patients admitted to the surgical service with the diagnosis of diverticular disease. Inclusion criteria were either diverticulitis confirmed at operation or radiographic findings consistent with the disease. Patient demographics, history, pertinent physical findings, and treatment were recorded. The data were analyzed after dividing the patients into two populations: a younger population 50 years of age or less, and a second population of patients older than 50. Results: During the interval, a total of 64 patients were admitted to the surgical service with the diagnosis of diverticulitis. The mean age of this population wa...

Objective:To evaluate if a family presence educational intervention during brain death evaluation... more Objective:To evaluate if a family presence educational intervention during brain death evaluation improves understanding of brain death without affecting psychological distress.Design:Randomized controlled trial.Setting:Four ICUs at an academic tertiary care center.Subjects:Immediate family members

Variational mode decomposition (VMD) has been widely applied to the field of machinery fault diag... more Variational mode decomposition (VMD) has been widely applied to the field of machinery fault diagnosis due to its good time-frequency decomposition capability. However, the performance of the VMD for extraction of fault transient components is dependent on proper parameters in the method and is not satisfactory under noisy conditions. This paper proposes a new method, termed multi-bandwidth mode manifold (Triple M, TM), to extract the real fault transient components for fault diagnosis of rolling bearings. The new TM method unites multiple fault-related modes with different bandwidths by a nonlinear manifold learning algorithm. The modes with large bandwidths contain more fault-related information while those with small bandwidths contain less fault-unrelated components and noise. The advantages of different fault-related modes are fully used by the proposed method, leading to clear fault transients that facilitates the bearing fault detection. First, an efficiency-improved VMD method named recycling VMD (RVMD) is performed on the bearing signal repeatedly with different parameter values to obtain the fault-related modes with different bandwidths, i.e., the multi-bandwidth modes. Then, the manifold learning algorithm is carried out to extract the intrinsic manifold structure of bearing fault transient components from the multi-bandwidth modes. Finally, the bearing fault type is identified from the extracted feature with clear fault transients. The enhanced performance of the proposed method over the traditional methods is validated by a simulation analysis and two experimental applications of bearing defect identifications. INDEX TERMS Fault diagnosis, manifold learning, recycling variational mode decomposition, rolling bearing, time-frequency signal decomposition.

The American Journal of Surgery, 2003

Digestive Diseases and Sciences, 2006

This study was done to examine the role of cyclooxygenase (COX) in lipopolysaccharide (LPS)induce... more This study was done to examine the role of cyclooxygenase (COX) in lipopolysaccharide (LPS)induced gastroprotection and gastric stasis. In conscious rats, LPS dose and time dependently increased gastric luminal fluid accumulation. LPS decreased blood flow (laser Doppler) and prevented gastric injury from acidified ethanol at time points before significant fluid accumulation occurred. LPS increased COX-2 but not COX-1 expression. In contrast, LPS decreased gastric mucosal prostaglandin synthesis. LPS-induced gastric luminal fluid accumulation was negated by both nonselective COX inhibition with salicylate and selective COX-2 inhibition with NS-398 but not by selective COX-1 inhibition with SC-560. Neither salicylate nor NS-398 blocked LPS-induced gastroprotection. LPS-induced gastroprotection does not depend entirely on accumulation of luminal fluid and is independent of COX-1 and COX-2. However, the ability of LPS to cause gastric stasis and increase gastric luminal fluid accumulation involves COX-2.

Digestive Diseases and Sciences, 2004

Severe injury remains a leading cause of death and morbidity in patients under 40, with the numbe... more Severe injury remains a leading cause of death and morbidity in patients under 40, with the number of annual trauma-related deaths approaching 160,000 in the United States. Patients who survive the initial trauma and post-traumatic resuscitation are at risk for immune dysregulation, which contributes to late mortality and accounts for approximately 20% of deaths after traumatic injury. This post-traumatic immunosuppressed state has been attributed to over-expression of anti-inflammatory mediators in an effort to restore host homeostasis. We measured a panel of monocyte markers and cytokines in 50 severely injured trauma patients for 3 days following admission. We made the novel observation that the subpopulation of monocytes expressing high levels of CD14 and CD16 was expanded in the majority of patients. These cells also expressed CD163 consistent with differentiation into alternatively activated macrophages with potential regulatory or wound-healing activity. We examined factors i...

Critical Care Medicine, 2008

Objective: Both nitric oxide synthase (NOS) and cyclooxygenase (COX) have inducible isoforms that... more Objective: Both nitric oxide synthase (NOS) and cyclooxygenase (COX) have inducible isoforms that are up-regulated during inflammatory states. However, the interaction between these enzymes is not clearly understood. The objective was to clarify the interactions between NOS and COX in the rat gastric mucosa in the presence and absence of lipopolysaccharide. Design: Laboratory study. Setting: Medical school laboratory. Subjects: Female Sprague-Dawley rats. Interventions: We used nonselective and selective COX inhibitors to determine the role of COX on inducible NOS (iNOS) expression in the gastric mucosa. Measurements and Main Results: The nonselective COX inhibitors salicylate and indomethacin enhanced the expression of iNOS in the rat gastric mucosa and exacerbated gastric injury in the presence of lipopolysaccharide, effects reversed by exogenous prostaglandin E2. Selective COX-1 inhibition with SC560 similarly increased gastric iNOS expression and exacerbated gastric injury, whil...

Journal of cardiothoracic and vascular anesthesia, Jun 6, 2018

The Journal of surgical research, Jan 11, 2017

The impact of general surgeons (GS) taking trauma call on patient outcomes has been debated. Comp... more The impact of general surgeons (GS) taking trauma call on patient outcomes has been debated. Complex hepatopancreatobiliary (HPB) injuries present a particular challenge and often require specialized care. We predicted no difference in the initial management or outcomes of complex HPB trauma between GS and trauma/critical care (TCC) specialists. A retrospective review of patients who underwent operative intervention for complex HPB trauma from 2008 to 2015 at an ACS-verified level I trauma center was performed. Chart review was used to obtain variables pertaining to demographics, clinical presentation, operative management, and outcomes. Patients were grouped according to whether their index operation was performed by a GS or TCC provider and compared. 180 patients met inclusion criteria. The GS (n = 43) and TCC (n = 137) cohorts had comparable patient demographics and clinical presentations. Most injuries were hepatic (73.3% GS versus 72.6% TCC) and TCC treated more pancreas injuri...

Journal of vascular and interventional radiology : JVIR, Jan 20, 2017

To evaluate efficacy and safety of a novel device that combines an inferior vena cava (IVC) filte... more To evaluate efficacy and safety of a novel device that combines an inferior vena cava (IVC) filter and central venous catheter (CVC) for prevention of pulmonary embolism (PE) in critically ill patients. In a multicenter, prospective, single-arm clinical trial, the device was inserted at the bedside without fluoroscopy and subsequently retrieved before transfer from the intensive care unit (ICU). The primary efficacy endpoint was freedom from clinically significant PE or fatal PE 72 hours after device removal or discharge, whichever occurred first. Secondary endpoints were incidence of acute proximal deep venous thrombosis (DVT), catheter-related thrombosis, catheter-related bloodstream infections, major bleeding events, and clinically significant thrombus (occupying > 25% of volume of filter) detected by cavography before retrieval. The device was placed in 163 critically ill patients with contraindications to anticoagulation; 151 (93%) were critically ill trauma patients, 129 (8...

The Journal of Immunology, Apr 1, 2011

Journal of Trauma and Acute Care Surgery, 2015

Introduction-A dysregulated immune response leading to sepsis is the most frequent cause of late ... more Introduction-A dysregulated immune response leading to sepsis is the most frequent cause of late post-traumatic deaths. We have found a novel anti-inflammatory pathway that is initiated by the acute phase protein, C-reactive protein (CRP), interacting with Fcγ receptor (FcγR) on monocytes. This pathway is protective in animal models of endotoxin shock. We hypothesized that genetic polymorphisms in the FcγR might contribute to monocyte responses and susceptibility to infectious complications after severe trauma. Methods-We conducted an observational study on a prospectively identified cohort of adult patients with convenience enrollment admitted after severe trauma. We enrolled 66 patients and collected blood samples at enrollment and again at 48 and 72 hrs. Patients were followed through their hospital stay and any septic events before 14 days were recorded. Cytokine and CRP levels were determined in the plasma from all three blood draws. Additionally, DNA was extracted from blood and analyzed for the 131 H/R FcγRIIa polymorphism that strongly affects the binding of IgG and CRP to this receptor. Results-Elevated levels of IL-8, IL-6, IL-10 MCP-1 as well as CRP were associated with reduced time to post-traumatic sepsis in Cox regression analysis. Expression of monocyte HLA-DR below 45% on patient monocytes was also associated with sepsis (HR = 3.15, 95% CI 1.45-6.93). Genetic analysis found that individuals with the polymorphism of the FcγRIIa receptor that binds CRP poorly were also more likely to have decreased monocyte HLA-DR and posttraumatic sepsis. In vitro studies showed that CRP could attenuate monocyte deactivation in volunteers with the polymorphism of the FcγRIIa receptor that binds CRP.

Journal of Surgical Research, 2015

Pelvic ring disruptions in blunt trauma are rarely an isolated finding. Many individuals needing ... more Pelvic ring disruptions in blunt trauma are rarely an isolated finding. Many individuals needing operative pelvic fixation also require laparotomy for other injuries. Pelvic fixation can be performed by open reduction and internal fixation (ORIF) or external fixation (Ex-fix). Often when a laparotomy incision is present, ORIF is performed by extending this incision. We hypothesized ORIF performed by extending the laparotomy incision would result in higher rates of ventral hernia and wound complications versus Ex-fix. All patients admitted from 2004-June 2014 who underwent laparotomy and pelvic fixation either by ORIF through extension of a laparotomy incision (ORIF group) or definitive Ex-fix group were identified. Injury severity score, demographics, associated injuries, and complications were collected. A total of 35 patients were identified who underwent laparotomy and pelvic fixation, 21 underwent Ex-fix, whereas 14 underwent ORIF through an extended laparotomy incision. There were no differences in injury severity score, demographics, associated injuries, or rate of ventral hernia. The ORIF group had more laparotomy incision infections (50.0% versus 4.8%, P < 0.01) and pelvic abscesses (42.9% versus 9.5%, P < 0.05). They required more procedures to address their complications (13 versus 5, P < 0.05). Individuals who have undergone laparotomy and pelvic fixation are a complex group of patients with multiple injuries. These data suggest that when surgical repair of a pelvic ring disruption is indicated and the patient has undergone laparotomy, careful consideration to the method of fixation should be given.

The journal of trauma and acute care surgery, 2013

Infection after severe trauma is a significant cause of morbidity and mortality days to weeks aft... more Infection after severe trauma is a significant cause of morbidity and mortality days to weeks after the initial injury. Apolipoproteins play important roles in host defense and circulating concentrations are altered by the acute inflammatory response. The purpose of this study was to determine if patients who acquire infection after severe trauma have significantly lower apolipoprotein levels than trauma patients who do not become infected. We conducted a case-control study on a prospectively identified cohort of adult patients admitted to our intensive care unit after severe trauma (Injury Severity Score ≥ 16). We compared plasma apolipoprotein levels between patients who acquired an infection within 30 days after trauma (cases) and those that remained infection free (controls). Of 40 patients experiencing severe trauma, we identified 22 cases that developed an infection within 30 days after injury. Cases had significantly lower posttrauma plasma levels of apolipoprotein B (p = 0.0...

Journal of Surgical Research, 2003

Journal of Surgical Research, 2014

Background: The purpose of this study was to examine the presentation of diverticulitis at an urb... more Background: The purpose of this study was to examine the presentation of diverticulitis at an urban county hospital serving predominantly indigent patients and to analyze the differences, if any, in presentation and treatment in younger patients. Methods: A retrospective review of medical records from 1995 to 2001 was performed at a single institution to identify patients admitted to the surgical service with the diagnosis of diverticular disease. Inclusion criteria were either diverticulitis confirmed at operation or radiographic findings consistent with the disease. Patient demographics, history, pertinent physical findings, and treatment were recorded. The data were analyzed after dividing the patients into two populations: a younger population 50 years of age or less, and a second population of patients older than 50. Results: During the interval, a total of 64 patients were admitted to the surgical service with the diagnosis of diverticulitis. The mean age of this population wa...

Objective:To evaluate if a family presence educational intervention during brain death evaluation... more Objective:To evaluate if a family presence educational intervention during brain death evaluation improves understanding of brain death without affecting psychological distress.Design:Randomized controlled trial.Setting:Four ICUs at an academic tertiary care center.Subjects:Immediate family members

Variational mode decomposition (VMD) has been widely applied to the field of machinery fault diag... more Variational mode decomposition (VMD) has been widely applied to the field of machinery fault diagnosis due to its good time-frequency decomposition capability. However, the performance of the VMD for extraction of fault transient components is dependent on proper parameters in the method and is not satisfactory under noisy conditions. This paper proposes a new method, termed multi-bandwidth mode manifold (Triple M, TM), to extract the real fault transient components for fault diagnosis of rolling bearings. The new TM method unites multiple fault-related modes with different bandwidths by a nonlinear manifold learning algorithm. The modes with large bandwidths contain more fault-related information while those with small bandwidths contain less fault-unrelated components and noise. The advantages of different fault-related modes are fully used by the proposed method, leading to clear fault transients that facilitates the bearing fault detection. First, an efficiency-improved VMD method named recycling VMD (RVMD) is performed on the bearing signal repeatedly with different parameter values to obtain the fault-related modes with different bandwidths, i.e., the multi-bandwidth modes. Then, the manifold learning algorithm is carried out to extract the intrinsic manifold structure of bearing fault transient components from the multi-bandwidth modes. Finally, the bearing fault type is identified from the extracted feature with clear fault transients. The enhanced performance of the proposed method over the traditional methods is validated by a simulation analysis and two experimental applications of bearing defect identifications. INDEX TERMS Fault diagnosis, manifold learning, recycling variational mode decomposition, rolling bearing, time-frequency signal decomposition.

The American Journal of Surgery, 2003

Digestive Diseases and Sciences, 2006

This study was done to examine the role of cyclooxygenase (COX) in lipopolysaccharide (LPS)induce... more This study was done to examine the role of cyclooxygenase (COX) in lipopolysaccharide (LPS)induced gastroprotection and gastric stasis. In conscious rats, LPS dose and time dependently increased gastric luminal fluid accumulation. LPS decreased blood flow (laser Doppler) and prevented gastric injury from acidified ethanol at time points before significant fluid accumulation occurred. LPS increased COX-2 but not COX-1 expression. In contrast, LPS decreased gastric mucosal prostaglandin synthesis. LPS-induced gastric luminal fluid accumulation was negated by both nonselective COX inhibition with salicylate and selective COX-2 inhibition with NS-398 but not by selective COX-1 inhibition with SC-560. Neither salicylate nor NS-398 blocked LPS-induced gastroprotection. LPS-induced gastroprotection does not depend entirely on accumulation of luminal fluid and is independent of COX-1 and COX-2. However, the ability of LPS to cause gastric stasis and increase gastric luminal fluid accumulation involves COX-2.

Digestive Diseases and Sciences, 2004

Severe injury remains a leading cause of death and morbidity in patients under 40, with the numbe... more Severe injury remains a leading cause of death and morbidity in patients under 40, with the number of annual trauma-related deaths approaching 160,000 in the United States. Patients who survive the initial trauma and post-traumatic resuscitation are at risk for immune dysregulation, which contributes to late mortality and accounts for approximately 20% of deaths after traumatic injury. This post-traumatic immunosuppressed state has been attributed to over-expression of anti-inflammatory mediators in an effort to restore host homeostasis. We measured a panel of monocyte markers and cytokines in 50 severely injured trauma patients for 3 days following admission. We made the novel observation that the subpopulation of monocytes expressing high levels of CD14 and CD16 was expanded in the majority of patients. These cells also expressed CD163 consistent with differentiation into alternatively activated macrophages with potential regulatory or wound-healing activity. We examined factors i...

Critical Care Medicine, 2008

Objective: Both nitric oxide synthase (NOS) and cyclooxygenase (COX) have inducible isoforms that... more Objective: Both nitric oxide synthase (NOS) and cyclooxygenase (COX) have inducible isoforms that are up-regulated during inflammatory states. However, the interaction between these enzymes is not clearly understood. The objective was to clarify the interactions between NOS and COX in the rat gastric mucosa in the presence and absence of lipopolysaccharide. Design: Laboratory study. Setting: Medical school laboratory. Subjects: Female Sprague-Dawley rats. Interventions: We used nonselective and selective COX inhibitors to determine the role of COX on inducible NOS (iNOS) expression in the gastric mucosa. Measurements and Main Results: The nonselective COX inhibitors salicylate and indomethacin enhanced the expression of iNOS in the rat gastric mucosa and exacerbated gastric injury in the presence of lipopolysaccharide, effects reversed by exogenous prostaglandin E2. Selective COX-1 inhibition with SC560 similarly increased gastric iNOS expression and exacerbated gastric injury, whil...

Journal of cardiothoracic and vascular anesthesia, Jun 6, 2018

The Journal of surgical research, Jan 11, 2017

The impact of general surgeons (GS) taking trauma call on patient outcomes has been debated. Comp... more The impact of general surgeons (GS) taking trauma call on patient outcomes has been debated. Complex hepatopancreatobiliary (HPB) injuries present a particular challenge and often require specialized care. We predicted no difference in the initial management or outcomes of complex HPB trauma between GS and trauma/critical care (TCC) specialists. A retrospective review of patients who underwent operative intervention for complex HPB trauma from 2008 to 2015 at an ACS-verified level I trauma center was performed. Chart review was used to obtain variables pertaining to demographics, clinical presentation, operative management, and outcomes. Patients were grouped according to whether their index operation was performed by a GS or TCC provider and compared. 180 patients met inclusion criteria. The GS (n = 43) and TCC (n = 137) cohorts had comparable patient demographics and clinical presentations. Most injuries were hepatic (73.3% GS versus 72.6% TCC) and TCC treated more pancreas injuri...

Journal of vascular and interventional radiology : JVIR, Jan 20, 2017

To evaluate efficacy and safety of a novel device that combines an inferior vena cava (IVC) filte... more To evaluate efficacy and safety of a novel device that combines an inferior vena cava (IVC) filter and central venous catheter (CVC) for prevention of pulmonary embolism (PE) in critically ill patients. In a multicenter, prospective, single-arm clinical trial, the device was inserted at the bedside without fluoroscopy and subsequently retrieved before transfer from the intensive care unit (ICU). The primary efficacy endpoint was freedom from clinically significant PE or fatal PE 72 hours after device removal or discharge, whichever occurred first. Secondary endpoints were incidence of acute proximal deep venous thrombosis (DVT), catheter-related thrombosis, catheter-related bloodstream infections, major bleeding events, and clinically significant thrombus (occupying > 25% of volume of filter) detected by cavography before retrieval. The device was placed in 163 critically ill patients with contraindications to anticoagulation; 151 (93%) were critically ill trauma patients, 129 (8...

The Journal of Immunology, Apr 1, 2011

Journal of Trauma and Acute Care Surgery, 2015

Introduction-A dysregulated immune response leading to sepsis is the most frequent cause of late ... more Introduction-A dysregulated immune response leading to sepsis is the most frequent cause of late post-traumatic deaths. We have found a novel anti-inflammatory pathway that is initiated by the acute phase protein, C-reactive protein (CRP), interacting with Fcγ receptor (FcγR) on monocytes. This pathway is protective in animal models of endotoxin shock. We hypothesized that genetic polymorphisms in the FcγR might contribute to monocyte responses and susceptibility to infectious complications after severe trauma. Methods-We conducted an observational study on a prospectively identified cohort of adult patients with convenience enrollment admitted after severe trauma. We enrolled 66 patients and collected blood samples at enrollment and again at 48 and 72 hrs. Patients were followed through their hospital stay and any septic events before 14 days were recorded. Cytokine and CRP levels were determined in the plasma from all three blood draws. Additionally, DNA was extracted from blood and analyzed for the 131 H/R FcγRIIa polymorphism that strongly affects the binding of IgG and CRP to this receptor. Results-Elevated levels of IL-8, IL-6, IL-10 MCP-1 as well as CRP were associated with reduced time to post-traumatic sepsis in Cox regression analysis. Expression of monocyte HLA-DR below 45% on patient monocytes was also associated with sepsis (HR = 3.15, 95% CI 1.45-6.93). Genetic analysis found that individuals with the polymorphism of the FcγRIIa receptor that binds CRP poorly were also more likely to have decreased monocyte HLA-DR and posttraumatic sepsis. In vitro studies showed that CRP could attenuate monocyte deactivation in volunteers with the polymorphism of the FcγRIIa receptor that binds CRP.

Journal of Surgical Research, 2015

Pelvic ring disruptions in blunt trauma are rarely an isolated finding. Many individuals needing ... more Pelvic ring disruptions in blunt trauma are rarely an isolated finding. Many individuals needing operative pelvic fixation also require laparotomy for other injuries. Pelvic fixation can be performed by open reduction and internal fixation (ORIF) or external fixation (Ex-fix). Often when a laparotomy incision is present, ORIF is performed by extending this incision. We hypothesized ORIF performed by extending the laparotomy incision would result in higher rates of ventral hernia and wound complications versus Ex-fix. All patients admitted from 2004-June 2014 who underwent laparotomy and pelvic fixation either by ORIF through extension of a laparotomy incision (ORIF group) or definitive Ex-fix group were identified. Injury severity score, demographics, associated injuries, and complications were collected. A total of 35 patients were identified who underwent laparotomy and pelvic fixation, 21 underwent Ex-fix, whereas 14 underwent ORIF through an extended laparotomy incision. There were no differences in injury severity score, demographics, associated injuries, or rate of ventral hernia. The ORIF group had more laparotomy incision infections (50.0% versus 4.8%, P < 0.01) and pelvic abscesses (42.9% versus 9.5%, P < 0.05). They required more procedures to address their complications (13 versus 5, P < 0.05). Individuals who have undergone laparotomy and pelvic fixation are a complex group of patients with multiple injuries. These data suggest that when surgical repair of a pelvic ring disruption is indicated and the patient has undergone laparotomy, careful consideration to the method of fixation should be given.

The journal of trauma and acute care surgery, 2013

Infection after severe trauma is a significant cause of morbidity and mortality days to weeks aft... more Infection after severe trauma is a significant cause of morbidity and mortality days to weeks after the initial injury. Apolipoproteins play important roles in host defense and circulating concentrations are altered by the acute inflammatory response. The purpose of this study was to determine if patients who acquire infection after severe trauma have significantly lower apolipoprotein levels than trauma patients who do not become infected. We conducted a case-control study on a prospectively identified cohort of adult patients admitted to our intensive care unit after severe trauma (Injury Severity Score ≥ 16). We compared plasma apolipoprotein levels between patients who acquired an infection within 30 days after trauma (cases) and those that remained infection free (controls). Of 40 patients experiencing severe trauma, we identified 22 cases that developed an infection within 30 days after injury. Cases had significantly lower posttrauma plasma levels of apolipoprotein B (p = 0.0...