Fenfluramine increases survival and reduces markers of neurodegeneration in a mouse model of Dravet syndrome.

OBJECTIVE: In patients with Dravet syndrome (DS), fenfluramine reduced convulsive seizure frequency and provided clinical benefit in nonseizure endpoints (e.g., executive function, survival). In zebrafish mutant scn1 DS models, chronic fenfluramine treatment preserved neuronal cytoarchitecture prior to seizure onset and prevented gliosis; here, we extend these findings to a mammalian model of DS (Scn1a+/- mice) by evaluating the effects of fenfluramine on neuroinflammation (degenerated myelin, activated microglia) and survival. METHODS: Scn1a+/- DS mice were treated subcutaneously once daily with fenfluramine (15 mg/kg) or vehicle from postnatal day (PND) 7 until 35-37. Sagittal brain sections were processed for immunohistochemistry using antibodies to degraded myelin basic protein (D-MBP) for degenerated myelin, or CD11b for activated (inflammatory) microglia; sections were scored semi-quantitatively. Apoptotic nuclei were quantified by TUNEL assay. Statistical significance was evaluated by 1-way ANOVA with post-hoc Dunnett's test (D-MBP, CD11b, and TUNEL) or Logrank Mantel-Cox (survival). RESULTS: Quantitation of D-MBP immunostaining per 0.1 mm2 unit area of the parietal cortex and hippocampus CA3 yielded significantly higher spheroidal and punctate myelin debris counts in vehicle-treated DS mice than in wild-type mice. Fenfluramine treatment in DS mice significantly reduced these counts. Activated CD11b + microglia were more abundant in DS mouse corpus callosum and hippocampus than in wild-type controls. Fenfluramine treatment of DS mice resulted in significantly fewer activated CD11b + microglia than vehicle-treated DS mice in these brain regions. TUNEL staining in corpus callosum was increased in DS mice relative to wild-type controls. Fenfluramine treatment in DS mice lowered TUNEL staining relative to vehicle-treated DS mice. By PND 35-37, 55% of control DS mice had died, compared with 24% of DS mice receiving fenfluramine treatment (P = 0.0291). SIGNIFICANCE: This is the first report of anti-neuroinflammation and pro-survival after fenfluramine treatment in a mammalian DS model. These results corroborate prior data in humans and animal models and suggest important pharmacological activities for fenfluramine beyond seizure reduction. PLAIN LANGUAGE SUMMARY: Dravet syndrome is a severe epilepsy disorder that impairs learning and causes premature death. Clinical studies in patients with Dravet syndrome show that fenfluramine reduces convulsive seizures. Additional studies suggest that fenfluramine may have benefits beyond seizures, including promoting survival and improving control over emotions and behavior. Our study is the first to use a Dravet mouse model to investigate nonseizure outcomes of fenfluramine. Results showed that fenfluramine treatment of Dravet mice reduced neuroinflammation significantly more than saline treatment. Fenfluramine-treated Dravet mice also lived longer than saline-treated mice. These results support clinical observations that fenfluramine may have benefits beyond seizures.

Patient outcomes and cost in robotic emergency general surgery.

The use of robotic technology in general surgery continues to increase, though its utility for emergency general surgery remains under-studied. This study explores the current trends in patient outcomes and cost of robotic emergency general surgery (REGS). The Florida Agency for Healthcare Administration database (2018-2020) was queried for adult patients undergoing intra-abdominal emergency general surgery within 24 h of admission and linked to CMS Cost Reports/Hospital Compare, American Hospital Association, and Rand Corporation Hospital datasets. Patients from the four most common REGS procedures were propensity matched to laparoscopic equivalents for hospital cost analysis. A telephone survey was performed with the top 10 REGS hospitals to identify key qualities for successful REGS programs. 181 hospitals (119 REGS, 62 non-REGS) performed 60,733 emergency surgeries. Six-percent were REGS. The most common REGS were cholecystectomy, appendectomy, inguinal and ventral hernia repairs. Before and after propensity matching, total cost for these four procedures were significantly higher than their laparoscopic equivalents, which was due to higher surgical cost as the non-operative costs did not differ. There were no differences in mortality, individual complications, or length of stay for most of the four procedures. REGS volume significantly increased each year. The survey found that 8/10 hospitals have robotic-trained staff available 24/7. Although REGS volume is increasing in Florida, cost remains significantly higher than laparoscopy. Given higher costs and lack of significantly improved outcomes, further study should be undertaken to better inform which specific patient populations would benefit from REGS.

Comparison of Continuous Albumin Infusion, Bolus Albumin, and Crystalloid Fluid Administration in Open-Abdomen Surgical-Trauma Patients.

Background: The open abdomen (OA), an intentional lack of fascial closure following abdominal cavity opening, is utilized for various indications among surgical-trauma patients. Among intravenous fluid options, administration of albumin as a continuous infusion may improve outcomes in OA. The purpose of this study is to compare the time to abdomen closure among patients with OA according to type of fluid administration. Methods: We conducted a retrospective cohort study of adults with OA from 2012 through 2018 and stratified by intravenous fluid administration into one of three groups: continuous albumin infusion, intermittent bolus albumin, or crystalloid. The primary outcome was median time to abdomen closure. Secondary outcomes included hemodynamic parameters, length of stay (LOS), and mortality. Time to final abdomen closure was analyzed by Cox proportional hazards regression. Results: Eighty-four patients were included with 28 in each cohort. Compared to crystalloids (44.2 [interquartile range, IQR, 36.3-62.9] hours), median time to abdomen closure was significantly longer in bolus albumin (79.0 [IQR, 44.5-130.8] hours; P = .002) and continuous albumin groups (63.6 [IQR, 42.9-139.6] hours; P = .001) in Cox regression analysis. The incidence of hospital mortality was highest in the bolus albumin cohort (continuous albumin: 21.4% vs bolus albumin: 50.0% vs crystalloid: 25.0%; P = .044). All other secondary outcomes were similar between groups. Conclusions: Among patients with OA, administration of intravenous crystalloid was associated with the shortest time to abdomen closure compared to bolus or continuous albumin. Further evaluation of continuous albumin infusion in patients with OA is needed.

Trough levels of ipilimumab in serum as a potential biomarker of clinical outcomes for patients with advanced melanoma after treatment with ipilimumab.

BACKGROUND: Immune checkpoint blockade (ICB) using anti-CTLA-4 and anti-PD-1/PD-L1 has revolutionized the treatment of advanced cancer. However, ICB is effective for only a small fraction of patients, and biomarkers such as expression of PD-L1 in tumor or serum levels of CXCL11 have suboptimal sensitivity and specificity. Exposure-response (E-R) relationships have been observed with other therapeutic monoclonal antibodies. There are many factors influencing E-R relationships, yet several studies have shown that trough levels of anti-PD-1/PD-L1 correlated with clinical outcomes. However, the potential utility of anti-CTLA-4 levels as a biomarker remains unknown. METHODS: Serum was obtained at trough levels at weeks 7 and 12 (after doses 2 and 4) from patients with advanced melanoma who received ipilimumab alone (3 mg/kg every 3 weeks for four treatments) via an expanded access program (NCT00495066). We have successfully established a proteomics assay to measure the concentration of ipilimumab in serum using an liquid chromatography with tandem mass spectrometry-based nanosurface and molecular-orientation limited proteolysis (nSMOL) approach. Serum samples from 38 patients were assessed for trough levels of ipilimumab by the nSMOL assay. RESULTS: We found that trough levels of ipilimumab were higher in patients who developed immune-related adverse events but did not differ based on the presence or absence of disease progression. We found that patients with higher trough levels of ipilimumab had better overall survival when grouped based on ipilimumab trough levels. Trough levels of ipilimumab were inversely associated with pretreatment serum levels of CXCL11, a predictive biomarker we previously identified, and soluble CD25 (sCD25), a prognostic biomarker for advanced melanoma, as well as C reactive protein (CRP) and interleukin (IL)-6 levels at week 7. CONCLUSIONS: Our results suggest that trough levels of ipilimumab may be a useful biomarker for the long-term survival of patients with advanced melanoma treated with ipilimumab. The association of ipilimumab trough levels with pretreatment serum levels of CXCL11 and sCD25 is suggestive of a baseline-driven E-R relationship, and the association of ipilimumab trough levels with on-treatment levels of CRP and IL-6 is suggestive of response-driven E-R relationship. Our findings highlight the potential utility of trough levels of ipilimumab as a biomarker. TRIAL REGISTRATION NUMBER: NCT00495066.

Should Hypotensive Trauma Patients Ever Be Transferred to a Trauma Center?

Many trauma patients present to nontrauma centers with emergency conditions. The Emergency Medical Treatment and Active Labor Act dictates that nontrauma centers attempt stabilization and provide appropriate transfer. Our goal was to determine whether there was a survival benefit in transferring hypotensive patients. The Tampa General Hospital trauma registry database was queried for adult trauma transfers from January 2012 to April 2018 including the first recorded systolic blood pressure (SBP) and other pertinent data. A manual chart review in hypotensive (SBP < 90) patients determined blood pressure at the time of transfer. Of the 3038 patients, 40 patients were hypotensive on arrival, with 40% (16) mortality. Eight of nine (88%) patients with SBP <70 on arrival, 3 of 11 (27%) with SBP 70 to 79, and 5 of 20 (25%) with SBP 80 to 89 died. The only survivor in the <70 group was normotensive at transport. Patients in these groups who were hypotensive at the time of transport died (4/4, 100%). Our data show no benefit in transferring patients with refractory hypotension at the time of transport; although the numbers are small, an SBP <70 should be considered prohibitive to transfer.

Nano-Pulse Stimulation is a physical modality that can trigger immunogenic tumor cell death.

BACKGROUND: We have been developing a non-thermal, drug-free tumor therapy called Nano-Pulse Stimulation (NPS) that delivers ultrashort electric pulses to tumor cells which eliminates the tumor and inhibits secondary tumor growth. We hypothesized that the mechanism for inhibiting secondary tumor growth involves stimulating an adaptive immune response via an immunogenic form of apoptosis, commonly known as immunogenic cell death (ICD). ICD is characterized by the emission of danger-associated molecular patterns (DAMPs) that serve to recruit immune cells to the site of the tumor. Here we present evidence that NPS stimulates both caspase 3/7 activation indicative of apoptosis, as well as the emission of three critical DAMPs: ecto-calreticulin (CRT), ATP and HMGB1. METHODS: After treating three separate cancer cell lines (MCA205, McA-RH7777, Jurkat E6-1) with NPS, cells were incubated at 37 °C. Cell-culture supernatants were collected after three-hours to measure for activated caspases 3/7 and after 24 h to measure CRT, ATP and HMGB1 levels. We measured the changes in caspase-3 activation with Caspase-Glo® by Promega, ecto-CRT with anti-CRT antibody and flow cytometry, ATP by luciferase light generation and HMGB1 by ELISA. RESULTS: The initiation of apoptosis in cultured cells is greatest at 15 kV/cm and requires 50 A/cm2. Reducing this current inhibits cell death. Activated caspase-3 increases 8-fold in Jurkat E6-1 cells and 40% in rat hepatocellular carcinoma and mouse fibrosarcoma cells by 3 h post treatment. This increase is non-linear and peaks at 15-20 J/mL for all field strengths. 10 and 30 kV/cm fields exhibited the lowest response and the 12 and 15 kV/cm fields stimulated the largest amount of caspase activation. We measured the three DAMPs 24 h after treatment. The expression of cell surface CRT increased in an energy-dependent manner in the NPS treated samples. Expression levels reached or exceeded the expression levels in the majority of the anthracycline-treated samples at energies between 25 and 50 J/mL. Similar to the caspase response at 3 h, secreted ATP peaked at 15 J/mL and then rapidly declined at 25 J/mL. HMGB1 release increased as treatment energy increased and reached levels comparable to the anthracycline-treated groups between 10 and 25 J/mL. CONCLUSION: Nano-Pulse Stimulation treatment at specific energies was able to trigger the emission of three key DAMPs at levels comparable to Doxorubicin and Mitoxantrone, two known inducers of immunogenic cell death (ICD). Therefore NPS is a physical modality that can trigger immunogenic cell death in tumor cells.

Lipoprotein(a) and vitamin C impair development of breast cancer tumors in Lp(a)+; Gulo-/- mice.

Cancer progression is characterized by loss of extracellular matrix (ECM) integrity, which is a precondition for tumor growth and metastasis. In order to elucidate the precise mechanisms of ECM degradation in cancer we used a genetically modified mouse mimicking two distinct human metabolic features associated with carcinogenesis, the lack of endogenous vitamin C synthesis and the production of human Lp(a). Female Lp(a)+; Gulo(-/-) and control wild-type Balb/c mice without these two metabolic features were orthotopically inoculated with 4T1 breast cancer cells (5x105). The transgenic and control mice were divided into 4 different dietary groups in respect to dietary vitamin C intake: i) low ascorbate intake for 6 weeks; ii) high ascorbate intake for 6 weeks; iii) low ascorbate intake for 3 weeks followed by high ascorbate for 3 weeks; iv) high ascorbate intake for 3 weeks followed by low ascorbate for 3 weeks. After 6 weeks, all wild-type mice developed tumors. In contrast, Lp(a)+; Gulo(-/-) mice developed one third less primary tumors (low ascorbate diet) or no primary tumors at all (high ascorbate diet). Significantly, tumors from Lp(a)+; Gulo(-/-) mice immunostained positively for Lp(a) and their size was inversely proportional to Lp(a) serum levels. The results implicate that Lp(a) may play a role in controlling tumor growth and expansion. The most likely mechanism is the competitive inhibition of plasmin-induced ECM degradation due to the homology of Lp(a) components to plasminogen. The confirmation of this pathomechanism could lead to a universal therapeutic target for the prevention and treatment of cancer.

Effect of a nutrient mixture on the localization of extracellular matrix proteins in HeLa human cervical cancer xenografts in female nude mice.

Cervical cancer is one of the most commonly diagnosed cancers and a significant cause of mortality in women worldwide. Although cervical cancer is fully treatable in the early stages, once it has metastasized, patient outcome is poor. The objective of the present study was to investigate the effect of dietary supplementation with a nutrient mixture (NM) containing lysine, ascorbic acid, proline, green tea extract and other micronutrients on the expression of extracellular matrix (ECM) proteins in HeLa cell xenografts in nude female mice. After housing for 1 week, female athymic nude mice between 5 and 6 weeks of age (n=12) were inoculated subcutaneously with 3×106 HeLa cells in phosphate-buffered saline and Matrigel and randomly divided into two groups. These were the control group, in which the mice were fed with regular mouse chow, and the NM group, in which the mice were fed with the regular diet supplemented with 0.5% NM (w/w). After 4 weeks, the tumors were excised and processed for histology. Tumor growth was evaluated and the tumors were stained for the ECM proteins collagen I, collagen IV, fibronectin, laminin, periodic acid-Schiff (PAS) and elastin. NM strongly inhibited (by 59%, P=0.001) the growth of HeLa xenografts in nude mice. Tumors from control mice exhibited little to no collagen I expression either internally or in the fibrous capsule, while tumors from the NM group expressed collagen I in the fibrous capsule and within the tumor. Tumors from the control group showed diffuse cytoplasmic and capsular collagen IV with abundant nucleated cells. NM treatment substantially increased collagen IV production and induced a dense fibrous network of collagen IV with chambers that surrounded live nucleated cells and large amounts of necrotic cell debris. Tumors from the mice fed with the NM exhibited a well-defined border of fibronectin in the capsule and intense areas of staining internally whereas control group tumors showed less overall fibronectin with sporadic internal staining and little in the fibrous capsule. Although laminin appeared abundantly in control and NM-treated tumors, the NM group tumors exhibited a chamber-like network of laminin internally. Tumors from the control group exhibited internal areas of intense PAS staining, whereas tumors from the NM-treated group exhibited a more uniform diffuse pattern of PAS staining. In conclusion, NM supplementation of HeLa xenograft-bearing female nude mice demonstrated a potent inhibition of tumor growth and enhancement of ECM proteins, suggesting the therapeutic value of this specific nutrient complex in the treatment of cervical cancer.

Measuring trauma system performance: Right patient, right place-Mission accomplished?

BACKGROUND: A regional trauma system must establish and monitor acceptable overtriage and undertriage rates. Although diagnoses from discharge data sets can be used with mortality prediction models to define high-risk injury, retrospective analyses introduce methodological errors when evaluating real-time triage processes. The purpose of this study was to determine if major trauma patients identified using field criteria correlated with those retrospectively labeled high risk and to assess system performance by measuring triage accuracy and trauma center utilization. METHODS: A statewide database was queried for all injury-related International Classification of Diseases, 9th Revision, code discharges from designated trauma centers and nontrauma centers for 2012. Children and burn patients were excluded. Patients assigned a trauma alert fee were considered field-triage(+). The International Classification Injury Severity Score methodology was used to estimate injury-related survival probabilities, with an International Classification Injury Severity Score less than 0.85 considered high risk. Triage rates were expressed relative to the total population; the proportion of low- and high-risk patients discharged from trauma centers defined trauma center utilization. RESULTS: There were 116,990 patients who met study criteria, including 11,368 (10%) high-risk, 70,741 field-triage(-) patients treated in nontrauma centers and 28,548 field-triage(-) and 17,791 field-triage(+) patients treated in trauma centers. Field triage was 86% accurate, with 10% overtriage and 4% undertriage. System triage was 66% accurate, with 32% overtriage and 2% undertriage. Overtriage patients more often, and undertriage patients less often, had severe injury characteristics than appropriately triaged patients. CONCLUSION: Trauma system performance assessed using retrospective administrative data provides a convenient measure of performance but must be used with caution. Residual mistriage can partly be attributed to error introduced by retrospective high-risk definitions, whereas differences between field and system triage accuracy can be attributed to the trauma center's role as a large community hospital. Given the limitations of the data and methods, these results may represent optimal patient distribution within this mature system.

Hypoascorbemia induces atherosclerosis and vascular deposition of lipoprotein(a) in transgenic mice.

Lipoprotein(a), a variant of LDL carrying the adhesive glycoprotein apo(a), is a leading risk factor for cardiovascular disease. Lipoprotein(a) (Lp(a)) is found in humans and subhuman primates but rarely in lower mammals. Better understanding of the evolutionary advantage of this molecule should elucidate its physiological role. We developed a new mouse model with two characteristics of human metabolism: the expression of Lp(a) and the lack of endogenous ascorbate (vitamin C) production. We show that dietary deficiency of ascorbate increases serum levels of Lp(a). Moreover, chronic hypoascorbemia and complete depletion of ascorbate (scurvy) leads to Lp(a) accumulation in the vascular wall and parallels atherosclerotic lesion development. The results suggest that dietary ascorbate deficiency is a risk factor for atherosclerosis independent of dietary lipids. We provide support for the concept that Lp(a) functions as a mobile repair molecule compensating for the structural impairment of the vascular wall, a morphological hallmark of hypoascorbemia and scurvy.

The injured elderly: a rising tide.

BACKGROUND: Injury remains a public health challenge despite advances in trauma care. Periodic survey of injury epidemiology is essential to the trauma system's continuous performance improvement. We undertook this study to characterize the changes in Florida injury rates during the past 15 years. METHODS: Injured patients were identified with the use of a statewide database over 15 years ending in 2010. Population data were obtained from the U.S. Census. Severe injury was defined by International Classification Injury Severity Scores less than 0.85. Injury rates were expressed in discharges per 100,000 residents. Trends were analyzed by linear regression. RESULTS: The 1.5 million patient discharges consisted of 5.2% children, 39.7% adults, and 55.1% elderly. The overall injury rate decreased in children by 18% but increased in adults by 2% and in the elderly by 17% during the study period. The proportion of severe injuries decreased in children and the elderly but did not change in adults. Injury patterns changed in all age groups. CONCLUSION: Injury in the elderly is increasing at a rate seven times that of adults. In 2010, the elderly accounted for only 17% of the population but 55% of injury-related discharges. These trends have dramatic implications for the design of future trauma systems and health care resource use.

Fifteen-year trauma system performance analysis demonstrates optimal coverage for most severely injured patients and identifies a vulnerable population.

BACKGROUND: Trauma systems are designed to deliver timely and appropriate care. Prehospital triage regulations and interfacility transfer guidelines are the primary determinants of system efficacy. We analyzed the effectiveness of the Florida trauma system in delivering trauma patients to trauma centers over time. STUDY DESIGN: Injured patients were identified by ICD-9 codes from a statewide discharge dataset, and they were categorized as children (less than 16 years old), adult (16 to 65 years old), or elderly (over 65 years old). Severe injury was defined by International Classification Injury Severity Scores (ICISS) < 0.85. Residence ZIP codes were used as a surrogate for injury location. RESULTS: Severe injury discharges increased at designated trauma centers (DTCs) and decreased at nontrauma centers (NTCs). The proportion of patients with severe injuries discharged from DTCs increased for all age groups, capturing nearly all severely injured children and adults. Access to DTCs was dependent on proximity for severely injured elderly but not for severely injured children and adults. CONCLUSIONS: Triage improved over time, enabling near complete capture of at-risk children and adults independent of DTC proximity. Because distance from a DTC does not limit access for children and adults, existing trauma system resources are sufficient to meet the current demands. Efforts are needed to determine the trauma resource and triage needs of the severely injured elderly.

Ascorbate supplementation inhibits growth and metastasis of B16FO melanoma and 4T1 breast cancer cells in vitamin C-deficient mice.

Degradation of the extracellular matrix (ECM) plays a critical role in the formation of tumors and metastasis and has been found to correlate with the aggressiveness of tumor growth and invasiveness of cancer. Ascorbic acid, which is known to be essential for the structural integrity of the intercellular matrix, is not produced by humans and must be obtained from the diet. Cancer patients have been shown to have very low reserves of ascorbic acid. Our main objective was to determine the effect of ascorbate supplementation on metastasis, tumor growth and tumor immunohistochemistry in mice unable to synthesize ascorbic acid [gulonolactone oxidase (gulo) knockout (KO)] when challenged with B16FO melanoma or 4T1 breast cancer cells. Gulo KO female mice 36-38 weeks of age were deprived of or maintained on ascorbate in food and water for 4 weeks prior to and 2 weeks post intraperitoneal (IP) injection of 5x105 B16FO murine melanoma cells or to injection of 5x105 4T1 breast cancer cells into the mammary pad of mice. Ascorbate-supplemented gulo KO mice injected with B16FO melanoma cells demonstrated significant reduction (by 71%, p=0.005) in tumor metastasis compared to gulo KO mice on the control diet. The mean tumor weight in ascorbate supplemented mice injected with 4T1 cells was reduced by 28% compared to tumor weight in scorbutic mice. Scorbutic tumors demonstrated large dark cores, associated with increased necrotic areas and breaches to the tumor surface, apoptosis and matrix metalloproteinase-9 (MMP-9), and weak, disorganized or missing collagen I tumor capsule. In contrast, the ascorbate-supplemented group tumors had smaller fainter colored cores and confined areas of necrosis/apoptosis with no breaches from the core to the outside of the tumor and a robust collagen I tumor capsule. In both studies, ascorbate supplementation of gulo KO mice resulted in profoundly decreased serum inflammatory cytokine interleukin (IL)-6 (99% decrease, p=0.01 in the B16F0 study and 85% decrease, p=0.08 in the 4T1 study) compared to the levels in gulo KO mice deprived of ascorbate. In the B16FO study, ascorbate supplementation of gulo KO mice resulted in profoundly decreased serum VEGF (98% decrease, p=0.019 than in the scorbutic gulo KO mice). As expected, mean serum ascorbate level in ascorbate-restricted mice was 2% (p<0.001) of the mean ascorbate levels in supplemented mice. In conclusion, ascorbate supplementation hinders metastasis, tumor growth and inflammatory cytokine secretion as well as enhanced encapsulation of tumors elicited by melanoma and breast cancer cell challenge in gulo KO mice.

Geographic distribution of severely injured patients: implications for trauma system development.

BACKGROUND: Despite decades of trauma system development, many severely injured patients fail to reach a trauma center for definitive care. The purpose of this study was to define the regions served by Florida's designated trauma centers and define the geographic distribution of severely injured patients who do not access the state's trauma system. METHODS: Severely injured patients discharged from Florida hospitals were identified using the 2009 Florida Agency for Health Care Administration database. The home zip codes of patients discharged from trauma and nontrauma center hospitals were used as a surrogate for injury location and plotted on a map. A radial distance containing 75% of trauma center discharges defined trauma center catchment area. RESULTS: Only 52% of severely injured patients were discharged from trauma centers. The catchment areas varied from 204 square miles to 12,682 square miles and together encompassed 92% state's area. Although 93% of patients lived within a trauma center catchment area, the proportion treated at a trauma center in each catchment area varied from 13% to 58%. Mapping of patient residences identified regions of limited access to the trauma system despite proximity to trauma centers. CONCLUSIONS: The distribution of severely injured patients who do not reach trauma centers presents an opportunity for trauma system improvement. Those in proximity to trauma centers may benefit from improved and secondary triage guidelines and interfacility transfer agreements, whereas those distant from trauma centers may suggest a need for additional trauma system resources. LEVEL OF EVIDENCE: Epidemiologic study, level III.

Implementation of an acute care surgery service at an academic trauma center.

BACKGROUND: The establishment of acute care surgery is rapidly becoming a solution to meet emergency surgical needs. Challenges include competition for emergency surgery opportunities and the ability to economically sustain a practice. METHODS: Clinical activity was measured by reviewing the institutional and practice plan databases. Work relative value units and practice plan collection rates defined clinical activity and revenue. RESULTS: Operative procedures and intensive care unit activity accounted for 52% and 36% of activity, respectively. Although procedures on the digestive tract accounted for half of the operative activity, significant activity was observed in nearly all other systems. Overall clinical productivity remained constant but did demonstrate a 25% increase in operative work relative value units. Current billing activity supports 4.0 clinical full-time equivalents, but estimated collections would cover <73% of physician direct costs. CONCLUSIONS: The authors describe the implementation of an acute care surgery service that combines trauma, emergency general surgery, and surgical critical care in an established academic surgery department. Developing a sustainable economic model must include income sources other than patient service revenue.

Distinctive ERK and p38 signaling in remote and infarcted myocardium during post-MI remodeling in the mouse.

Global activation of MAP kinases has been reported in both human and experimental heart failure. Chronic remodeling of the surviving ventricular wall after myocardial infarction (MI) involves both myocyte loss and fibrosis; we hypothesized that this cardiomyopathy involves differential shifts in pro- and anti-apoptotic MAP kinase signaling in cardiac myocyte (CM) and non-myocyte. Cardiomyopathy after coronary artery ligation in mice was characterized by echocardiography, ex vivo Langendorff preparation, histologic analysis and measurements of apoptosis. Phosphorylation (activation) of signaling molecules was analyzed by Western blot, ELISA and immunohistochemistry. Post-MI remodeling involved dramatic changes in the phosphorylation of both stress-activated MAP (SAP) kinase p38 as well as ERK, a known mediator of cell survival, but not of SAP kinase JNK or the anti-apoptotic mediator of PI3K, Akt. Phosphorylation of p38 rose early after MI in the infarct, whereas a more gradual rise in the remote myocardium accompanied a rise in apoptosis in that region. In both areas, ERK phosphorylation was lowest early after MI and rose steadily thereafter, though infarct phosphorylation was consistently higher. Immunostaining of p-ERK localized to fibrotic areas populated primarily by non-myocytes, whereas staining of p38 phosphorylation was stronger in areas of progressive CM apoptosis. Relative segregation of CMs and non-myocytes in different regions of the post-MI myocardium revealed signaling patterns that imply cell type-specific changes in pro- and anti-apoptotic MAP kinase signaling. Prevention of myocyte loss and of LV remodeling after MI may therefore require cell type-specific manipulation of p38 and ERK activation.

Nutrient supplementation modulates angiotensin II-mediated atherosclerosis in ApoE KO mice.

We studied the effect of nutrient/herbal extract mixture (NM) supplementation prior to angiotensin II (AngII) administration on ApoE KO mice. AngII-mediated injuries, which included increased atherosclerotic lesion size (by 31%) and severity (by 200%), as well as an increased number of necrotic cores (by 44%), were attenuated by NM supplementation, resulting in the reduction of lesion size by 20% (p=0.09), lesion severity by 31% (p=0.13) and the average number of necrotic cores per arterial tree by 39% (p=0.35), compared to mice fed the regular diet. The frequency of Type B thoracic aortic dissections and abdominal aneurysms in AngII-treated mice was reduced from 55.6% to 14.3 and 42.97%, respectively, with NM supplementation. Macrophage density in the aortic lesions of NM-supplemented AngII-treated mice was 20% lower (p=0.033) than in mice on the regular diet, whereas collagen density in NM mice was increased by 208% (p=0.026) compared to that in mice fed the regular diet, making for a more stable plaque type. NM-supplemented mice showed a significant reduction in total cholesterol (32% decrease, p=0.0001) and LDL (66% decrease, p<0.0001), commonly measured risk factors for cardiovascular disease. In conclusion, NM consumption prior to AngII administration in ApoE KO mice minimized aortic dissections, inflammatory monocyte recruitment to plaques, plaque mass and abdominal aortic dilation.

Evolution of angiotensin II-mediated atherosclerosis in ApoE KO mice.

The dysregulation of renin-angiotensin system-signaling is a contributing factor to the development of atherosclerosis and cardiovascular disease. We studied the progression of angiotensin II (AngII)-induced arterial wall atherosclerosis after its induction. Atherosclerosis was accelerated in ApoE (-/-) C57B6 mice by 4 weeks of continuous osmotic pump administration of AngII (23 nmol/24 h). Changes in aortae were evaluated in these mice at 4 and 16 weeks after pump installation, as well as in control mice that were not administered AngII. In comparison to the non-AngII controls, AngII supplementation induced additional lesions in the aortic arch and its vessels 4 weeks after pump installation, indicating that AngII had an effect. These observations were grossly visible and were confirmed through histological analysis. Additionally, the AngII-mediated injuries continued to accelerate great vessel atherosclerosis after the discontinuation of AngII administration at 4 weeks. Atherosclerosis in the ApoE KO mice at 16 weeks post-AngII administration was increased by over 3-fold compared to the difference between lesion development in the ApoE KO mice at 4 weeks post-AngII and the age-matched control ApoE KO mice. While lesion size 12 weeks after cessation of AngII (16 week post-AngII group) increased 249% compared to the 4 week post-AngII group, differences between the rate of lesion formation in the 4 week post-AngII and non-AngII groups indicated a 70% increase and a linear relationship with time. Aortic dissections were present at 4 weeks post-AngII pump installation at high frequency compared to the unsupplemented controls, in which they were absent. Unexpectedly, aortic dissections were absent at 16 weeks post-AngII, indicating the presence of a healing process. The study suggests that excessive AngII initiates a cascade of pathological biochemical events and plaque evolution that does not cease even after AngII administration is discontinued.

Diagnostic peritoneal lavage remains a valuable adjunct to modern imaging techniques.

BACKGROUND: Continuing improvements in computerized tomography scan technology and widespread acceptance of focused abdominal sonography for trauma (FAST) have prompted the suggestion that diagnostic peritoneal lavage (DPL) is obsolete. This sentiment, coupled with decreasing resident familiarity with DPL, has led to a poor understanding of the modern indications for DPL and no clear guidelines. We hypothesized that, while its indications may have changed, DPL remains essential in the rapid, effective triage of the trauma patient. METHODS: We queried our Level I trauma center's trauma registry from January 1996 through August 2006 for patients who underwent a DPL as part of their initial evaluation. Specific variables investigated were indications for or results of DPL, performance of a laparotomy in the first 24 hours, and operative findings. RESULTS: Six hundred twenty-seven patients underwent DPL (145 positive, 482 negative). Although the accuracy of DPL for predicting therapeutic laparotomy for all patients was only 77%, in the subset of hemodynamically unstable patients (of which only 46% had a positive FAST), it was 100%. Conversely, only 7% of all patients with negative DPL subsequently had a therapeutic laparotomy, with only 5% in the subset of stab wounds. CONCLUSION: DPL continues to be a vital tool in the evaluation of the trauma patient. A positive test in the hemodynamically unstable patient with potential multisystem trauma allows for expeditious intervention. A negative test in abdominal stab wounds supports observation and early subsequent discharge. Our current guidelines continue to emphasize the complimentary roles of DPL, FAST, and computerized tomography scan in the trauma bay.

Myocardial survival signaling in response to stem cell transplantation.

BACKGROUND: Experimental human stem cell transplantation to the heart has begun, but the mechanisms underlying benefits seen in preclinical models, both at the site of cell injection and at more distant regions, remain uncertain. We hypothesize that these benefits can be best understood first at the level of key intracellular signaling cascades in the host myocardium, which can be responsible for functional and structural preservation of the heart. STUDY DESIGN: Western blot and ELISA were used to assess key pathways that regulate cardiac myocyte survival and hypertrophy in both the infarct/borderzone and remote myocardium of C57/B6 mouse hearts subjected to coronary artery ligation, with subsequent injection of either vehicle or bone marrow-derived adult mesenchymal stem cells (MSC). RESULTS: Improved left ventricular function with MSC transplantation was associated with a relative preservation of Akt phosphorylation (activation) and of phosphorylation of downstream mediators of cell survival and hypertrophy. There was no substantial difference in activation of mitogen-activated protein kinase p38, and activation of the antiapoptotic mitogen-activated protein kinase extracellular signal-regulated kinase was lower at 1 week after MSC treatment, but rose beyond controls by week 2. Similar changes were observed in both the infarct/borderzone and the remote myocardium. CONCLUSION: Stem cell transplantation in the post-MI murine myocardium is associated with preservation of Akt signaling. Together with a possible later increase in extracellular signal-regulated kinase activation, this signaling change might be responsible for cardioprotection. Additional focused investigation might identify elements in transplantation regimens that optimize this mechanism of benefit, and that can increase the likelihood of human clinical success.