Disparities in delivery of ophthalmic care; An exploration of public Medicare data

Purpose

Cataract is a major cause of age-related eye diseases in the United States, and cataract extraction is the most commonly performed surgery on Medicare beneficiaries. Analyzing the pattern in delivery of cataract care at the national level can highlight areas of disparities. We evaluated geographic disparities seen in cataract surgery delivery to Medicare beneficiaries in the United States.

Setting

Cataract extractions across the United States in 2012.

Design

Cross-sectional study examining distance to provider and observed versus expected number of cataract extractions.

Methods

Cataract extraction current procedural terminology codes were used to sum the total observed number of cataract extractions per cataract surgeon. Epidemiology data on expected number of cataract surgeries in one year by decade of life were extrapolated via a Gaussian Process model. A linear regression model was used to compare differences in delivery of care between US economic regions.

Results

2.2 million patients underwent cataract surgery in the Medicare dataset in 2012. The average distance to the nearest provider was 9.846 miles (standard deviation: 11.410 miles). This distance was statistically significant (p < 2.0 x 10⁻²²) in the New England (5.935 mi), Mideast (6.356 mi), Great Lakes (8.733 mi), Far West (9.038 mi), Southeast (9.793 mi), Southwest (12.711 mi), Plains (16.047 mi), and Rocky Mountain (17.934 mi) regions. The total number of expected cataract surgeries greater than 100 miles to the nearest cataract surgeon was 1,901, where Montana, South Dakota, and Texas each had over 200 of these expected distances.

Conclusions

A large discrepancy exists in cataract delivery to the Medicare population based on geographic factors. Patients who live in rural areas travel farther on average to see ophthalmologists, resulting in a lower observed than expected rate of cataract surgery. Our results have implications in future allocation of resources and ophthalmologists.

[Influence of different inner dressings in negative-pressure wound therapy on escharectomy wound of full-thickness burn rabbits]

Objective: To explore the influence of different inner dressings in negative-pressure wound therapy (NPWT) on escharectomy wound of full-thickness burn rabbits. Methods: Eighteen Japanese white rabbits were inflicted with full-thickness burn on unilateral back. They were divided into polymer dressing group (PD), biological dressing group (BD), and silver biological dressing group (SBD), according to the random number table, with 6 rabbits in each group. On 3 days post burn, the wounds were performed with escharectomy, and then wounds of rabbits in group PD were covered with polyurethane foam. Wounds of rabbits in group BD were covered with porcine acellular dermal matrix (ADM) and wounds of rabbits in group SBD were covered with silver porcine ADM. Then continuous NPWT was performed on rabbits of the three groups for 7 days. Immediately after surgery and on post surgery day (PSD) 7, general observation of wound was conducted and tissue around the wound was harvested for determination of dry to wet weight ratio. The content of bacteria was counted and the content of tumor necrosis factor α (TNF-α), interleukin-1β (IL-1β), and IL-6 in wound was determined by enzyme-linked immunosorbent assay. Fibroblasts in wound were counted after Masson staining and number of microvessels was counted after CD31 antibody immunohistochemical staining. Data were processed with analysis of variance for repeated measurement, LSD-t test, paired samples t test, and Bonferroni correction. Results: (1) Immediately after surgery, there was no granulation tissue in basal wound of rabbits in the three groups, with rich blood supply and obvious edema. On PSD 7, much granulation tissue was found in basal wound of rabbits in the three groups, with no or mild edema and no obvious redness and swelling in wound edge. (2) There were no significant differences in dry to wet weight ratios of tissue around the wound among and within the three groups immediately after surgery and on PSD 7 (with F values respectively 0.70 and 0.09, t values from 0.17 to 0.52, P values above 0.05). (3) Immediately after surgery, the content of bacteria in wounds of rabbits in groups PD, BD, and SBD was respectively (603.0±146.0) ×10(4,) (573.0±63.0) ×10(4,) and (590.0±100.0)×10(4) colony-forming unit (CFU)/g, with no significant difference among them (F=0.13, P>0.05). On PSD 7, the content of bacteria in wounds of rabbits in groups PD, BD, and SBD were respectively (5.4±0.8) ×10(4,) (4.6±0.9) ×10(4,) and (3.5±0.9)×10(4) CFU/g. Among them, the content of bacteria in wounds of rabbits in group SBD was lower than that in groups PD and BD, respectively (with t values respectively 3.78 and 2.29, P<0.05 or P<0.01). The content of bacteria in wounds of rabbits in the three groups on PSD 7 was decreased compared with that immediately after surgery (with t values from 10.05 to 21.81, P values below 0.01). (4) There was no significant difference in content of TNF-α, IL-1β, and IL-6 in wounds of rabbits in the three groups immediately after surgery and on PSD 7 (with F values from 0.10 to 1.89, P values above 0.05). The content of TNF-α in wounds of rabbits in the three groups on PSD 7 was significantly higher than that immediately after surgery (with t values from 2.93 to 5.01, P<0.05 or P<0.01). (5) There was no significant difference in amount of fibroblasts in wounds of rabbits in the three groups immediately after surgery and on PSD 7 (with F values respectively 0.01 and 0.81, P values above 0.05). The amount of fibroblasts in wounds of rabbits in the three groups on PSD 7 was larger than that immediately after surgery (with t values from 4.78 to 11.58, P values below 0.01). (6) There was no significant difference in number of microvessels in wounds of rabbits in the three groups immediately after surgery and on PSD 7 (with F values respectively 2.42 and 2.49, P values above 0.05). The number of microvessels in wounds of rabbits in the three groups on PSD 7 was larger than that immediately after surgery (with t values from 7.17 to 11.14, P values below 0.01). Conclusions: SBD is better at inhibiting the growth of bacteria. PD, BD, and SBD have almost the same effects on reducing tissue edema and inflammatory reaction, and on promoting the accumulation of collagen fibers and tissue vascularization.

Comparison of retina specialist preferences regarding spectral-domain and swept-source optical coherence tomography angiography

Purpose

The aim of this study was to compare physician preferences regarding the commercially available spectral-domain (SD) optical coherence tomography angiography (OCTA) and swept-source (SS) OCTA prototype device.

Design

Comparative analysis of diagnostic instruments was performed.

Patients and methods

Subjects at the University of Washington Eye Institute and Harborview Medical Center were prospectively recruited and imaged with the Zeiss SD OCTA (HD-5000, Angioplex) and Zeiss SS OCTA (Plex Elite, Everest) devices on the same day. The study included 10 eyes from 10 subjects diagnosed with a retinal/choroidal disease. Deidentified images were compiled into a survey and sent to retina specialists in various countries. The survey presented masked SD and SS images of each eye for each retinal sublayer side by side. Respondents were asked about their image preference and impact on clinical management. A priori and post hoc preferences for SD vs SS were collected.

Results

Fifty-four retina specialists responded to the survey. Median years in practice was 3.00 (interquartile range [IQR] 1.50–17.00). At baseline, 23 (48%) physicians owned an OCTA machine. The majority of physician responses showed a preference for the SS over SD OCTA, independent of the retinal pathology shown (n=454 overall responses, 74%). Nevertheless, the majority indicated that both SD and SS would be equally valuable in informing clinical decisions (n=374 overall responses, 61%).

Conclusion

These findings indicate that the majority of retina specialists surveyed prefer SS over SD OCTA based on image quality, regardless of the retinal pathology shown. Regarding the clinical utility of each modality, the majority of physicians perceive SD and SS as equally effective.

Validation of the Total Visual Acuity Extraction Algorithm (TOVA) for Automated Extraction of Visual Acuity Data From Free Text, Unstructured Clinical Records

PURPOSE

With increasing volumes of electronic health record data, algorithm-driven extraction may aid manual extraction. Visual acuity often is extracted manually in vision research. The total visual acuity extraction algorithm (TOVA) is presented and validated for automated extraction of visual acuity from free text, unstructured clinical notes.

METHODS

Consecutive inpatient ophthalmology notes over an 8-year period from the University of Washington healthcare system in Seattle, WA were used for validation of TOVA. The total visual acuity extraction algorithm applied natural language processing to recognize Snellen visual acuity in free text notes and assign laterality. The best corrected measurement was determined for each eye and converted to logMAR. The algorithm was validated against manual extraction of a subset of notes.

RESULTS

A total of 6266 clinical records were obtained giving 12,452 data points. In a subset of 644 validated notes, comparison of manually extracted data versus TOVA output showed 95% concordance. Interrater reliability testing gave κ statistics of 0.94 (95% confidence interval [CI], 0.89-0.99), 0.96 (95% CI, 0.94-0.98), 0.95 (95% CI, 0.92-0.98), and 0.94 (95% CI, 0.90-0.98) for acuity numerators, denominators, adjustments, and signs, respectively. Pearson correlation coefficient was 0.983. Linear regression showed an R² of 0.966 (P < 0.0001).

CONCLUSIONS

The total visual acuity extraction algorithm is a novel tool for extraction of visual acuity from free text, unstructured clinical notes and provides an open source method of data extraction.

TRANSLATIONAL RELEVANCE

Automated visual acuity extraction through natural language processing can be a valuable tool for data extraction from free text ophthalmology notes.

Quantifying Sarcopenia Reference Values Using Lumbar and Thoracic Muscle Areas in a Healthy Population

BACKGROUND

Sarcopenia is defined as the loss of skeletal muscle mass and function associated with aging. Muscle mass can be reliably and accurately quantified using clinical CT scans but reference measurements are lacking, particularly in healthy US populations.

METHODS

Two-phase CT scans from healthy kidney donors (age 18-40) at the University of Michigan between 1999-2010 were utilized. Muscle mass was quantified using two thoracic and two lumbar muscle cross-sectional area (CSA) measures. Indexed measurements were computed as area divided by height-squared. Paired analyses of non-contrast and contrast phases and different Hounsfield Unit (HU) ranges for muscle were conducted to determine their effect on CSA muscle measures. We report the means, standard deviations, and 2SD sarcopenia cutoffs from this population.

RESULTS

Healthy population CSA (cm2) cutoffs for N=604 males/females respectively were: 34.7/20.9 (T12 Dorsal Muscle), 91.5/55.9 (T12 Skeletal Muscle), 141.7/91.2 (L3 Skeletal Muscle), 23.5/14.3 (L4 Total Psoas Area), and 23.4/14.3 (L4 Psoas Muscle Area). Height-indexed CSA (cm2/m2) cutoffs for males/females respectively were: 10.9/7.8 (T12 Dorsal Muscle), 28.7/20.6 (T12 Skeletal Muscle), 44.6/34.0 (L3 Skeletal Muscle), 7.5/5.2 (L4 Total Psoas Area), and 7.4/5.2 (L4 Psoas Muscle Area). We confirmed that a mask of -29 to 150 HU is optimal and shows no significant difference between contrast-enhanced and non-contrast CT scan CSA measurements.

CONCLUSIONS

We quantified reference values for lumbar and thoracic muscle CSA measures in a healthy US population. We defined the effect of IV contrast and different HU ranges for muscle. Combined, these results facilitate the extraction of clinically valuable data from the large numbers of existing scans performed for medical indications.

[Effects on wound bed of deep burn following eschar excision with different wound management in rabbits]

OBJECTIVE

To compare the effects on wound bed of deep burn following eschar excision with different wound management in rabbits.

METHODS

Eighteen full-thickness burns models of Japanese white rabbits were established. They were randomly divided into 3 groups of traditional dressing, biological dressing and negative pressure wound therapy (NPWT) (n=6 each), according to the random number table. Eschar excision was performed three days later. The wound bed was observed and wound tissue was harvested for counting the quantity of bacteria, tissue dry wet ratio, measuring the level of tumor necrosis factor alpha (TNF-α), interleukin (IL)-1β and IL-6, the amount of collagen fibers and the microvessel density instantly and again seven days later. Statistical analyses were performed.

RESULTS

The NPWT group was better than other groups by observing the wound bed. The quantity of bacteria of traditional dressing group, biological dressing group and NPWT group at the time point of seven days after escharectomy turned out to be (9.4±1.5)×10(4,) (8.1±2.7)×10(4,) (3.9±0.7)×10(4) cfu/g, the NPWT group was significantly lower than traditional dressing group and biological dressing group (both P<0.05), and all lower than that at the time point of the day when escharectomy was performed (576.9±169.5)×10(4,) (589.9±99.6)×10(4,) (583.0±160.4)×10(4) cfu/g ( all P<0.05). There were no statistically significant differences among three groups at two time points in tissue dry wet ratio (all P>0.05). The IL-6 of biological dressing group was higher than that of traditional dressing group at the time point of seven days after the eschar excision was performed[(94±10) vs (76±8) ng/L, P<0.05]. The amount of collagen fibers of three group at the time point of seven days after escharectomy turned out to be (60±9), (55±12), (77±17). The NPWT group was significantly higher than traditional dressing group and biological dressing group (P<0.05), and all higher than that at the time point of the day when escharectomy was performed[(39±6), (39±11), (38±6)](all P<0.05). The microvessel density of three groups at the time point of seven days after escharectomy turned out to be (42±6), (53±4), (82±10). The NPWT group was higher than that of the other two groups, and biological dressing group was higher than that of traditional dressing group (all P<0.05). The biological dressing group and NPWT group were both higher than that of the day when the eschar excision was performed (36±5) and (36±5) (P<0.05).

CONCLUSIONS

NPWT is the optimal selection for wound to inhibit the growth of bacteria, promote the accumulation of collagen and tissue vascularization. But these managements have similar effects on reducing tissue edema and inflammatory reaction.

Bone mineral density predicts posttransplant survival among hepatocellular carcinoma liver transplant recipients

Hepatocellular carcinoma (HCC) is a common indication for liver transplantation (LT). Recent data suggest that body composition features strongly affect post-LT mortality. We examined the impact of body composition on post-LT mortality in patients with HCC. Data on adult LT recipients who received Model for End-Stage Liver Disease exception for HCC between February 29, 2002, and December 31, 2013, and who had a computed tomography (CT) scan any time 6 months prior to LT were reviewed (n = 118). All available CT scan Digital Imaging and Communication in Medicine files were analyzed using a semiautomated high throughput methodology with algorithms programmed in MATLAB. Analytic morphomics measurements including dorsal muscle group (DMG) area, visceral and subcutaneous fat, and bone mineral density (BMD) were taken at the bottom of the eleventh thoracic vertebral level. Thirty-two (27%) patients died during the median follow-up of 4.4 years. The number of HCC lesions (hazard ratio [HR], 2.81; P < 0.001), BMD (HR = 0.90/Hounsfield units [HU]; P = 0.03), pre-LT locoregional therapy (HR = 0.14; P < 0.001), and donor age (HR = 1.05; P < 0.001) were the independent predictors of post-LT mortality. DMG area did not affect post-LT survival. In conclusion, in addition to number of HCC lesions and pre-LT locoregional therapy, low BMD, a surrogate for bone loss rather than DMG area, was independently associated with post-LT mortality in HCC patients. Bone loss may be an early marker of deconditioning that precedes sarcopenia and may affect transplant outcomes. Liver Transplantation 22 1092-1098 2016 AASLD.

Access to Subspecialty Care And Survival Among Patients With Liver Disease

OBJECTIVES

Access to subspecialty care may be difficult for patients with liver disease, but it is unknown whether access influences outcomes among this population. Our objectives were to determine rates and predictors of access to ambulatory gastrointestinal (GI) subspecialty care for patients with liver disease and to determine whether access to subspecialty GI care is associated with better survival.

METHODS

We studied 28,861 patients within the Veterans Administration VISN 11 Liver Disease cohort who had an ICD-9-CM diagnosis code for liver disease from 1 January 2000 through 30 May 2011. Access was defined as a completed outpatient clinic visit with a gastroenterologist or hepatologist at any time after diagnosis. Multivariable logistic regression was used to determine predictors of access to a GI subspecialist. Survival curves were compared between those who did and those who did not see a specialist, with propensity score adjustment to account for other covariates that may affect access.

RESULTS

Overall, 10,710 patients (37%) had a completed GI visit. On multivariable regression, older patients (odds ratio (OR) 0.98, P<0.001), those with more comorbidities (OR 0.98, P=0.01), and those living farther from a tertiary-care center (OR 0.998/mi, P<0.001) were less likely to be seen in clinic. Patients who were more likely to be seen included those who had hepatitis C (OR 1.5, P<0.001) or cirrhosis (OR 3.5, P<0.001) diagnoses prior to their initial visit. Patients with an ambulatory GI visit at any time after diagnosis were less likely to die at 5 years when compared with propensity-score-matched controls (hazard ratio 0.81, P<0.001).

CONCLUSIONS

Access to ambulatory GI care was associated with improved 5-year survival for patients with liver disease. Innovative care coordination techniques may prove beneficial in extending access to care to liver disease patients.

Body Composition Features Predict Overall Survival in Patients With Hepatocellular Carcinoma

OBJECTIVES

Existing prognostic models for patients with hepatocellular carcinoma (HCC) have limitations. Analytic morphomics, a novel process to measure body composition using computational image-processing algorithms, may offer further prognostic information. The aim of this study was to develop and validate a prognostic model for HCC patients using body composition features and objective clinical information.

METHODS

Using computed tomography scans from a cohort of HCC patients at the VA Ann Arbor Healthcare System between January 2006 and December 2013, we developed a prognostic model using analytic morphomics and routine clinical data based on multivariate Cox regression and regularization methods. We assessed model performance using C-statistics and validated predicted survival probabilities. We validated model performance in an external cohort of HCC patients from Parkland Hospital, a safety-net health system in Dallas County.

RESULTS

The derivation cohort consisted of 204 HCC patients (20.1% Barcelona Clinic Liver Cancer classification (BCLC) 0/A), and the validation cohort had 225 patients (22.2% BCLC 0/A). The analytic morphomics model had good prognostic accuracy in the derivation cohort (C-statistic 0.80, 95% confidence interval (CI) 0.71-0.89) and external validation cohort (C-statistic 0.75, 95% CI 0.68-0.82). The accuracy of the analytic morphomics model was significantly higher than that of TNM and BCLC staging systems in derivation (P<0.001 for both) and validation (P<0.001 for both) cohorts. For calibration, mean absolute errors in predicted 1-year survival probabilities were 5.3% (90% quantile of 7.5%) and 7.6% (90% quantile of 12.5%) in the derivation and validation cohorts, respectively.

CONCLUSION

Body composition features, combined with readily available clinical data, can provide valuable prognostic information for patients with newly diagnosed HCC.

Quantitative detection of cirrhosis: towards the development of computer-assisted detection method

There are distinct morphologic features of cirrhosis on CT examinations; however, such impressions may be subtle or subjective. The purpose of this study is to build a computer-aided diagnosis (CAD) method to help radiologists with this diagnosis. One hundred sixty-seven abdominal CT examinations were randomly divided into training (n = 88) and validation (n = 79) sets. Livers were analyzed for morphological markers of cirrhosis and logistic regression models were created. Using the area under curve (AUC) for model performance, the best model had 0.89 for the training set and 0.85 for the validation set. For radiology reports, sensitivity of reporting cirrhosis was 0.45 and specificity 0.99. Using the predictive model adjunctively, radiologists' sensitivity increased to 0.63 and specificity slightly decreased to 0.97. This study demonstrates that quantifying morphological features in livers may be utilized for diagnosing cirrhosis and for developing a CAD method for it.

Visceral adiposity is negatively associated with bone density and muscle attenuation

BACKGROUND

The storage of adipose tissue in ectopic compartments is a hallmark attribute linking greater body mass index (BMI) with cardiometabolic diseases. Despite ample evidence to confirm that increased visceral adipose tissue (VAT) deposition occurs with obesity, the interrelations between altered fat partitioning and regional muscle and bone quality are less well understood.

OBJECTIVE

We examined the association between adiposity and spinal muscle and bone quality across a large, heterogeneous cohort of adults.

DESIGN

We identified 8833 thoracic or abdominal computed tomography scans from patients in the University of Michigan Health System who were aged 18-64.9 y. We measured trabecular bone densities, cortical bone densities, VAT areas, and subcutaneous adipose tissue (SAT) areas at vertebral levels T7 to L5. Psoas muscle attenuation (an indicator of fat infiltration in muscle) was measured at the L4 level.

RESULTS

Muscle attenuation as well as trabecular and cortical bone densities revealed negative correlations with BMI, SAT, and VAT. The correlation between BMI and psoas attenuation was -0.321, between BMI and the density of cortical bone was -0.250, and between BMI and trabecular bone was -0.143 (all P < 0.001). However, correlations between VAT and lower muscle attenuation were stronger as were those between VAT and lower bone densities. Inverse correlations between VAT and densities of psoas muscle and cortical and trabecular bone were -0.460, -0.407, and -0.434, respectively (P < 0.001). Even after adjustment for age, sex, and BMI, partial correlations between VAT, muscle attenuation, and bone densities remained significant at -0.250, -0.119, and -0.216, respectively (P < 0.001).

CONCLUSIONS

Contrary to previous reports that high body mass is associated with increased bone quality, our data show a significant negative association between BMI and muscle and bone densities, suggesting fat infiltration into these tissues. More importantly, correlations between VAT and decreased bone and muscle densities remained statistically significant even after adjustment for age, sex, and BMI.

Predictors of mortality in patients with hepatocellular carcinoma undergoing transarterial chemoembolization

BACKGROUND/AIM

Transarterial chemoembolization (TACE) is the recommended treatment for patients with Barcelona stage B hepatocellular carcinoma; however, community practice varies from these American Association for the Study of Liver Diseases guidelines. In this study, we sought to assess factors determining outcome after TACE and examine adherence to guidelines.

METHODS

From January 2006 to December 2012, 308 patients with newly diagnosed HCC were treated at the Veterans Affairs (VA) Ann Arbor Healthcare System. Of these, 109 patients underwent TACE. The primary outcome measured mortality. Kaplan-Meier analysis was used to determine the cumulative probability of death. Cox regression was used to assess the predictors of mortality.

RESULTS

The median age of the 109 patients was 60 years (48-90), 97 % were males and 82 % had chronic HCV infection. The median size of the largest lesion was 4 cm, 51 % were multifocal, and portal vein thrombosis was present in 3.6 %. Sixty-two patients died after median 333 days from the index TACE treatment. Median overall survival from index TACE was 11.2 months. Unadjusted 1-, 2-, and 3-year survival was 64, 35, and 24 %, respectively. CTP score (B vs. A: HR 2.51, p = 0.002; C vs. A: HR 7.96, p < 0.0001) and presence of complete response to TACE (HR 0.51, p = 0.004) were independent predictors of mortality. Barcelona stage (p = 0.88) and performance status as measured by ECOG (p = 0.98) were not associated with mortality after TACE.

CONCLUSIONS

In this community based, single VA center study, we found a significant number of patients beyond Barcelona stage B were treated with TACE. Advanced TNM stage, poor liver synthetic function and achieving CR with TACE were better predictors of mortality than guideline-directed decisions based on Barcelona stage. These factors may be useful to guide future patient selection for TACE.

Abstract 619: A Role for Macrophage Lipopolysaccharide Binding Protein in Atherosclerosis Development

Introduction: The liver X receptors (LXRs) are members of the nuclear receptor superfamily that regulate sterol metabolism and inflammation. Knockout of LXRs in macrophages greatly accelerates the development of atherosclerosis whereas pharmacological LXR activation has potent athero-protective effects. Previous studies have shown that deletion of LXR target genes in hematopoietic cells can have opposing effects on atherosclerosis development. For example, deletion of ABCA1 using bone marrow transfer in atherogenic mouse models showed increases atherosclerotic plaque burden where as knockout studies of ABCG1 and Aim1 decreased lesion formation in bone marrow transplantation experiments owing to an increase in macrophage apoptosis.

Rationale: We sought to identify previously unknown genes regulated by LXRs in macrophages and to determine their contribution to atherogenesis.

Methods & Results: We demonstrate that the lipopolysaccharide binding protein (LBP), a secreted glycoprotein, is an LXR target gene in macrophages. Treatment of mouse peritoneal macrophages with modified LDL or oxysterols induces LBP expression, an effect that was lost in LXRαβ-/- macrophages, consistent with a role for LBP in the cellular response to cholesterol overload. To investigate this further, we performed bone marrow transplant studies using WT or LBP-/- donors and LDLR-/- recipients. After 18 weeks of western diet feeding atherosclerotic lesion burden was assessed by en face and aortic root section analysis. LDLR-/- mice receiving LBP-/- bone marrow had markedly smaller lesions compared to those receiving WT (P<0.0001 in en face analysis; P<.01 in root section analysis). Furthermore, loss of bone marrow LBP expression led to a strong increase in apoptosis in atherosclerotic lesions as determined by TUNEL staining. In vitro studies with isolated macrophages and stable cell lines showed that LBP expression does not affect cholesterol efflux but promotes the survival of macrophages in the setting of cholesterol loading.

Conclusions: The LBP gene is a macrophage LXR target that promotes foam cell survival and atherogenesis. Our study identifies LBP as a potential diagnostic and therapeutic target in human cardiovascular disease.

The macrophage LBP gene is an LXR target that promotes macrophage survival and atherosclerosis

The liver X receptors (LXRs) are members of the nuclear receptor superfamily that regulate sterol metabolism and inflammation. We sought to identify previously unknown genes regulated by LXRs in macrophages and to determine their contribution to atherogenesis. Here we characterize a novel LXR target gene, the lipopolysaccharide binding protein (LBP) gene. Surprisingly, the ability of LXRs to control LBP expression is cell-type specific, occurring in macrophages but not liver. Treatment of macrophages with oxysterols or loading with modified LDL induces LBP in an LXR-dependent manner, suggesting a potential role for LBP in the cellular response to cholesterol overload. To investigate this further, we performed bone marrow transplant studies. After 18 weeks of Western diet feeding, atherosclerotic lesion burden was assessed revealing markedly smaller lesions in the LBP(-/-) recipients. Furthermore, loss of bone marrow LBP expression increased apoptosis in atherosclerotic lesions as determined by terminal deoxynucleotidyl transferase dUTP nick end labeling staining. Supporting in vitro studies with isolated macrophages showed that LBP expression does not affect cholesterol efflux but promotes the survival of macrophages in the setting of cholesterol loading. The LBP gene is a macrophage-specific LXR target that promotes foam cell survival and atherogenesis.

The quantification of liver anatomical changes and assessment of occupant liver injury patterns

Liver injuries can be significant in vehicle crashes. In this study, the liver anatomy was quantified in both adult and pediatric populations as a function of gender and age. Five anatomical liver measurements were determined using CT scans of 260 normal livers. These measurements include the area and volume, and the length, width, and girth of the liver (IRB HUM00041441). To characterize geometrical shape, an inscribed sphere and circumscribed ellipsoid were fitted on the measurements. In the pediatric population the liver area and volume continuously increased with age. When normalized by patient weight, volume measurements show a decrease in volume with age, suggesting that the liver occupies a smaller proportion of the body with age. In the adult population, liver measurements varied with gender. The superior and inferior locations of the liver were also recorded with respect to the spine. The lower portion was at the L3 in small children and at L2 as children approached puberty. It stayed in that area through the 60+ group, offering more ribcage protection. Liver injury patterns were also assessed in crash occupants. Seventy-two occupants with moderate to severe (AIS 2+) liver injuries were investigated. A new methodology was presented and consisted of quantifying blood volumes. The results were compared to overall liver volume and injury scales. No clear distinction on the injury pattern was observed by age group. Liver injuries were more commonly associated with AIS 2+ thoracic injuries in adults than in children. Most injuries occurred in the right lobe.

Early detection of burn induced heterotopic ossification using transcutaneous Raman spectroscopy

INTRODUCTION

Heterotopic ossification (HO), or the abnormal formation of bone in soft tissue, occurs in over 60% of major burn injuries and blast traumas. A significant need exists to improve the current diagnostic modalities for HO which are inadequate to diagnose and intervene on HO at early time-points. Raman spectroscopy has been used in previous studies to report on changes in bone composition during bone development but has not yet been applied to burn induced HO. In this study, we validate transcutaneous, in-vivo Raman spectroscopy as a methodology for early diagnosis of HO in mice following a burn injury.

METHODS

An Achilles tenotomy model was used to study HO formation. Following tenotomy, mice were divided into burn and sham groups with exposure of 30% surface area on the dorsum to 60° water or 30° water for 18s respectively. In-vivo, transcutaneous Raman spectroscopy was performed at early time points (5 days, 2 and 3 weeks) and a late time point (3 months) on both the tenotomized and non-injured leg. These same samples were then dissected down to the bone and ex-vivo Raman measurements were performed on the excised tissue. Bone formation was verified with Micro CT and histology at corresponding time-points.

RESULTS

Our Raman probe allowed non-invasive, transcutaneous evaluation of heterotopic bone formation. Raman data showed significantly increased bone mineral signaling in the tenotomy compared to control leg at 5 days post injury, with the difference increasing over time whereas Micro CT did not demonstrate heterotopic bone until three weeks. Ex-vivo Raman measurements showed significant differences in the amount of HO in the burn compared to sham groups and also showed differences in the spectra of new, ectopic bone compared to pre-existing cortical bone.

CONCLUSIONS

Burn injury increases the likelihood of developing HO when combined with traumatic injury. In our in-vivo mouse model, Raman spectroscopy allowed for detection of HO formation as early as 5 days post injury. Changes in bone mineral and matrix composition of the new bone were also evidenced in the Raman spectra which could facilitate early identification of HO and allow more timely therapy decisions for HO patients.

Effectiveness of hepatocellular carcinoma surveillance in patients with cirrhosis

BACKGROUND

Surveillance for hepatocellular carcinoma (HCC) is recommended in patients with cirrhosis, but the effectiveness of a surveillance program in clinical practice has yet to be established.

AIMS

To evaluate the effectiveness of a surveillance program with ultrasound and alpha-fetoprotein (AFP) to detect early HCCs.

METHODS

Four hundred and forty-six patients with Child A/B cirrhosis were prospectively enrolled between January 2004 and September 2006 and followed until July 2010. HCC surveillance using ultrasound and AFP was conducted per the treating hepatologist, although the standard was every 6 to 12 months. HCC was diagnosed using American Association for the Study of Liver Disease (AASLD) guidelines and early HCC defined by Barcelona Clinic Liver Cancer (BCLC) staging. Performance characteristics were determined for surveillance using AFP, ultrasound, or the combination.

RESULTS

After a median follow-up of 3.5 years, 41 patients developed HCCs, of whom 30 (73.2%) had early HCCs. The annual incidence of HCC was 2.8%, with cumulative 3- and 5-year incidence rates of 5.7% and 9.1%, respectively. Surveillance ultrasound and AFP had sensitivities of 44% and 66% and specificities of 92% and 91%, respectively, for the detection of HCCs. Sensitivity significantly improved to 90%, with minimal loss in specificity (83%) when these tests were used in combination.

CONCLUSIONS

When used as a surveillance program in a real-world clinical setting, combination of ultrasound and AFP is the most effective strategy to detect HCC at an early stage.

IMPACT

Our results differ from the guidelines of the AASLD.

Lipopolysaccharide binding protein inhibitory peptide alters hepatic inflammatory response post-hemorrhagic shock

Translocation of microorganisms and endotoxin (LPS) across the gastrointestinal mucosa may exacerbate the inflammatory response and potentiate hepatic injury associated with hemorrhagic shock. Lipopolysaccharide binding protein (LBP) augments LPS signaling through TLR4. In addition, evidence suggests that TLR4-mediated injury in liver ischemia/reperfusion occurs through the IRF-3/MyD88 independent pathway. We hypothesized that administration of LBP inhibiting peptide, LBPK95A, given at the time of resuscitation would reduce liver inflammation and injury in a murine model of hemorrhagic shock by limiting LPS-induced activation of the MyD88 independent pathway. Hemorrhagic shock was induced in male, C57BL/6 mice; a mean arterial blood pressure of 35 mmHg was maintained for 2.5 h. LBPK95A peptide or equal volume Lactated Ringer's solution was administered followed by fluid resuscitation. Mice were sacrificed at 2 and 6 h post-resuscitation. At 2 h, liver mRNA levels revealed a significant reduction in IFN-β, a cytokine produced via the MyD88 independent pathway, with LBPK95A treatment. However, mRNA levels of TNF-α, a cytokine associated with the MyD88 dependent pathway, were unaffected by treatment. The LBP inhibitory peptide did selectively reduce activation of TLR4 signaling via the IRF-3/MyD88 independent pathway. These results suggest that LBP promotes cytokine production through the MyD88 independent pathway during hemorrhagic shock.

Lipopolysaccharide binding protein is down-regulated during acute liver failure

BACKGROUND AND AIMS

Lipopolysaccharide binding protein (LBP) is involved in the modulation of acute liver injury and failure caused by acetaminophen (APAP). Although the biological activity of LBP is concentration dependent, little is known about its levels in acute liver failure.

METHODS

Serum and hepatic LBP were measured in acute APAP-induced liver injury in mice. Serum LBP was measured in patients with acute liver failure from APAP and non-APAP causes.

RESULTS

Interestingly, contrary to other diseases, serum and hepatic LBP levels decreased significantly in mice within 24 h after being subjected to APAP-induced injury compared to the control (1.6 ± 0.1 vs. 3.5 ± 1.6 μg/ml, respectively; P < 0.05). Similar decreases were noted in another mouse model of acute liver injury due to carbon tetrachloride. Among patients with acute liver failure due to APAP (n = 5) and non-APAP (n = 5) causes, admission LBP levels were decreased compared to those of healthy controls (5.4 ± 1.4 vs. 3.2 ± 0.2 μg/ml, normal vs. acute liver failure; P = 0.07). However, the levels were not associated with the etiology of acute liver failure or 3-week outcome.

CONCLUSIONS

Serum and hepatic LBP levels are significantly reduced early after the induction of severe acute liver injury/failure due to acetaminophen and other liver injuries. This reduction in LBP production is specific to acute liver failure and may be important in developing future diagnostic and therapeutic approaches for patients with acute liver failure.

Development of a quantitative method for the diagnosis of cirrhosis

OBJECTIVE

To develop a novel non-invasive, quantitative approach utilizing computed tomography scans to predict cirrhosis.

MATERIALS AND METHODS

A total of 105 patients (54 cirrhosis and 51 normal) who had CT scans within 6 months of a liver biopsy or were identified through a Trauma registry were included in this study. Patients were randomly divided into the training set (n = 81) and the validation set (n = 24). Each liver was segmented in a semi-automated fashion from a computed tomography scan using Mimics software. The resulting liver surfaces were saved as a stereo lithography mesh into an Oracle database, and analyzed in MATLAB(®) for morphological markers of cirrhosis.

RESULTS

The best predictive model for diagnosing cirrhosis consisted of liver slice-bounding box slice ratio, the dimensions of the liver bounding box, liver slice area, slice perimeter, surface volume and adjusted surface area. With this model, we calculated an area under the receiver operating characteristic curve of 0.90 for the training set, and 0.91 for the validation set. For comparison, we calculated an area under the receiver operating characteristic curve of 0.70 for our dataset when we used the lab value based aspartate aminotransferase-platelet ratio index, another reported model for predicting cirrhosis. Last, by combining the aspartate aminotransferase-platelet ratio index and our model, we obtained an area under the receiving operating characteristic of 0.95.

CONCLUSION

This study shows "proof of concept" that quantitative image analysis of livers on computed tomography scans may be utilized to predict cirrhosis in the absence of a liver biopsy.

Body mass index and obesity- and diabetes-associated genotypes and risk for pancreatic cancer

BACKGROUND

The genetic factors predisposing individuals with obesity or diabetes to pancreatic cancer have not been identified.

AIMS

To investigate the hypothesis that obesity- and diabetes-related genes modify the risk of pancreatic cancer.

METHODS

We genotyped 15 single nucleotide polymorphisms of fat mass and obesity-associated (FTO), peroxisome proliferators-activated receptor gamma (PPARγ), nuclear receptor family 5 member 2 (NR5A2), AMPK, and ADIPOQ genes in 1,070 patients with pancreatic cancer and 1,175 cancer-free controls. Information on risk factors was collected by personal interview. Adjusted ORs (AOR) and 95% CIs were calculated using unconditional logistic regression.

RESULTS

The PPARγ P12A GG genotype was inversely associated with risk of pancreatic cancer (AOR, 0.21; 95% CI, 0.07-0.62). Three NR5A2 variants that were previously identified in a genome-wide association study were significantly associated with reduced risk of pancreatic cancer, AORs ranging from 0.57 to 0.79. Two FTO gene variants and one ADIPOQ variant were differentially associated with pancreatic cancer according to levels of body mass index (BMI; P(interaction) = 0.0001, 0.0015, and 0.03). For example, the AOR (95% CI) for FTO IVS1-2777AC/AA genotype was 0.72 (0.55-0.96) and 1.54 (1.14-2.09) in participants with a BMI of less than 25 or 25 kg/m(2) or more, respectively. We observed no significant association between AMPK genotype and pancreatic cancer and no genotype interactions with diabetes or smoking.

CONCLUSION

Our findings suggest the PPARγ P12A GG genotype and NR5A2 variants may reduce the risk for pancreatic cancer. A positive association of FTO and ADIPOQ gene variants with pancreatic cancer may be limited to persons who are overweight.

IMPACT

The discovery of genetic factors modifying the risk of pancreatic cancer may help to identify high-risk individuals for prevention efforts.

Lipopolysaccharide binding protein inhibitory peptide protects against acetaminophen-induced hepatotoxicity

Acetaminophen (APAP)-induced liver injury remains the main cause of acute liver failure in the United States. Our previous work demonstrated that LPS binding protein (LBP) knockout mice are protected from APAP-induced hepatotoxicity. LBP is known to bind avidly to LPS, facilitating cellular activation. In this study, we sought to specifically inhibit the interaction between LBP and LPS to define the role of this interaction in APAP-induced liver injury. The peptide LBPK95A was able to inhibit LBP-mediated LPS activation of RAW 267.4 cells in a dose-dependent manner in vitro. In vivo, C57Bl/6 mice were treated with either LBPK95A or vehicle control concurrently with the administration of APAP (350 mg/kg). Mice treated with LBPK95A had significantly lower serum aspartate aminotransferase and alanine aminotransferase levels. Morphometric analysis of the liver tissue showed significantly less liver injury in mice treated with LBPK95A. To assess whether the LBPK95A altered glutathione depletion and APAP metabolism, we measured total glutathione levels in the liver after APAP. We found no difference in the glutathione levels and APAP-adduct formation between LBPK95A vs. vehicle control both at baseline and after APAP. In conclusion, our results support the hypothesis that LBP-induced liver injury after APAP is due to its ability to mediate activation by endogenous LPS. Our results suggest that blocking LBP-LPS interactions is a potential therapeutic avenue for the treatment of APAP-induced liver injury.

Serum fibrosis markers are associated with liver disease progression in non-responder patients with chronic hepatitis C

OBJECTIVES

The aim of this study was to explore the association of serum fibrosis marker levels with the risk of clinical and histological disease progression in a large cohort of patients with chronic hepatitis C (CHC).

METHODS

462 prior non-responders to peginterferon and ribavirin enrolled in the randomised phase of the Hepatitis C Antiviral Long-term Treatment against Cirrhosis (HALT-C) Trial had baseline and annual serum samples tested for hyaluronic acid (HA), N-terminal peptide of procollagen type 3, tissue inhibitor of matrix metalloproteinase-1 (TIMP-1) and YKL-40. All patients underwent a pretreatment liver biopsy and follow-up biopsies at years 2 and 4. Histological progression was defined as a ≥2 point increase in Ishak fibrosis score in patients without cirrhosis. Clinical outcomes included development of decompensation, hepatocellular cancer, death or an increase in the CTP (Child-Turcotte-Pugh) score to ≥7.

RESULTS

Mean patient age was 49.5 years and 39% had histological cirrhosis at entry. Baseline HA, YKL-40 and TIMP-1 levels combined with other laboratory parameters were all significantly associated with clinical outcomes in the 69 (15%) patients with disease progression (p<0.0001). The best multivariate model to predict clinical outcomes included baseline bilirubin, albumin, international normalised ratio (INR) and YKL-40 levels. All of the baseline serum fibrosis marker levels were also significantly associated with histological fibrosis progression that developed in 70 (33%) of the 209 patients with cirrhosis (p <0.0001). However, baseline HA and platelet counts were best at predicting histological progression (area under the curve (AUC)=0.663).

CONCLUSION

Pretreatment serum fibrosis marker levels are significantly increased in patients with CHC at risk of clinical and histological disease progression. If validated in additional cohorts, measurement of these markers could help identify patients with CHC who would benefit from more frequent and intensive monitoring.

Burn-induced heart failure: lipopolysaccharide binding protein improves burn and endotoxin-induced cardiac contractility deficits

BACKGROUND

Burn injury is frequently complicated by bacterial infection. Following burn injury, exposure to endotoxin produces a measurable decrease in cardiomyocyte sarcomere contractile function. Lipopolysaccharide-binding protein (LBP) is an acute phase protein that potentiates the recognition of lipopolysaccharide (LPS) by binding to the lipid A moiety of LPS. In this study, we sought to determine the effect of recombinant rat LBP (rLBP) on cardiomyocyte sarcomere function after burn or sham injury in the presence or absence of bacterial endotoxin.

METHODS

Rats underwent a full-thickness 30% total body surface area scald or sham burn. At 24 h post-injury, cardiomyocytes were isolated, plated at 50,000 cells/well, and incubated with 50 μg/mL LPS and rLBP or chloramphenicol acetyltransferase (BVCat, an irrelevant control protein produced using the same expression system as rLBP) at concentrations by volume of 1%, 5%, 10%, and 30%. Subsets of cardiomyocytes were incubated with 5% rat serum or 30% rLBP and blocking experiments were conducted using an LBP-like synthetic peptide (LBPK95A). In vitro sarcomere function was measured using a variable rate video camera system with length detection software.

RESULTS

Co-culture of burn and sham injury derived cardiomyocytes with high-dose rLBP in the presence of LPS resulted in a significant reduction to the functional impairment observed in peak sarcomere shortening following exposure to LPS alone. LBP-like peptide LBPK95A at a concentration of 20 μg/mL, in the presence of LPS, abolished the ability of 30% rLBP and 5% rat serum to restore peak sarcomere shortening of cardiomyocytes isolated following burn injury to levels of function exhibited in the absence of endotoxin exposure.

CONCLUSIONS

In the setting of LPS challenge following burn injury, rLBP at high concentrations restores cardiomyocyte sarcomere contractile function in vitro. Rather than potentiating the recognition of LPS by the cellular LPS receptor complex, rLBP at high concentrations likely results in an inhibitory binding effect that minimizes the impact of endotoxin exposure on cardiomyocyte function following thermal injury.

Local wound p38 MAPK inhibition attenuates burn-induced cardiac dysfunction

BACKGROUND

Topical inhibition of activated p38 MAPK within burn wounds attenuates the local and systemic inflammatory response. In this study, we investigated the effects of local activated p38 MAPK inhibition on burn-induced cardiac dysfunction.

METHODS

Using a standardized rat model of scald burn injury, rats were given a 30% total body surface area partial thickness burn or sham injury, and the wounds were treated with an activated p38 MAPK inhibitor (SB) or vehicle. Systemic blood pressure measurements were recorded in vivo followed by in vitro assessment of sarcomere contraction in single-cell suspensions of isolated cardiomyocytes.

RESULTS

Systolic blood pressure or maximum left ventricular pressures in vivo and peak cardiomyocyte sarcomere contractility in vitro were significantly reduced after burn injury. These functional deficits were abolished 24 h after burn injury following local p38 MAPK inhibition. In vitro incubation of normal cardiomyocytes with homogenate from burned skin or burn serum resulted in a similar pattern of impaired cardiomyocyte contractility. These effects were reversed in normal cardiomyocytes exposed to burn skin homogenates treated topically with a p38 MAPK inhibitor. A Western blot analysis showed that cardiac p38 MAPK activation was not affected by dermal blockade of activated p38 MAPK, arguing against systemic absorption of the inhibitor and indicating the involvement of systemic cytokine signaling.

CONCLUSION

Topical activated p38 MAPK inhibition within burned skin attenuates the release of proinflammatory mediators and prevents burn-induced cardiac dysfunction after thermal injury. These results support the inhibition of burn-wound inflammatory signaling as a new therapeutic approach to prevent potential postthermal injury multiorgan dysfunction syndrome.

Serum fibrosis marker levels decrease after successful antiviral treatment in chronic hepatitis C patients with advanced fibrosis

BACKGROUND & AIMS

Serum fibrosis marker levels during the lead-in treatment phase of patients enrolled in the Hepatitis C Antiviral Long-term Treatment against Cirrhosis (HALT-C) trial were determined.

METHODS

Week 0, 24, 48, and 72 serum samples were analyzed for YKL-40, tissue inhibitor of matrix metalloproteinase-1, amino-terminal peptide of type III procollagen (PIIINP), and hyaluronic acid (HA) levels. All 456 chronic hepatitis C (CHC) patients received peginterferon alfa 2a and ribavirin for 24 to 48 weeks.

RESULTS

Mean age was 49.2 years, 71% were male, and 39% had cirrhosis. Lower pretreatment serum YKL-40, tissue inhibitor of matrix metalloproteinase-1, PIIINP, and HA levels were associated significantly with week-20 virologic response (P < .0001). In multivariate analysis, non-1 CHC genotype, non-black race, prior interferon monotherapy, and lower baseline serum aspartate aminotransferase/alanine aminotransferase levels and log(10)YKL-40 levels were associated independently with week-20 virologic response. Statistically significant declines in all marker levels were observed at week 72 compared with baseline in the 81 patients with a sustained virologic response, but not in the 72 patients with breakthrough or relapse. At weeks 24 and 48, significant increases were observed in serum PIIINP and HA levels compared with baseline in virologic responders and nonresponders (P < .0001).

CONCLUSIONS

Pretreatment YKL-40 levels are an independent predictor of initial virologic response to peginterferon and ribavirin treatment. Levels of all 4 serum fibrosis markers decreased significantly in the SVR patients, consistent with reduced hepatic fibrogenesis. Measuring serum fibrosis marker levels before and after antiviral therapy may provide important prognostic information in CHC patients.

LPS-binding protein mediates LPS-induced liver injury and mortality in the setting of biliary obstruction

It is generally accepted that low levels of lipopolysaccharide (LPS)-binding protein (LBP) augment the cell's response to LPS, whereas high levels of LBP have been shown to inhibit cell responses to LPS. Clinical studies and in vitro work by our group have demonstrated that, in the setting of liver disease, increased or acute-phase levels of LBP may actually potentiate rather than inhibit an overwhelming proinflammatory response. Therefore, in the present studies we sought to determine the role of acute-phase LBP in mediating morbidity and mortality in animals challenged with LPS in the setting of biliary obstruction. Using LBP-deficient mice and LBP blockade in wild-type mice, we demonstrate that high levels of LBP are deleterious in the setting of cholestasis. Following biliary obstruction and intraperitoneal LPS challenge, hepatic injury, hepatic neutrophil infiltration, and mortality were significantly increased in animals with an intact LBP acute-phase response. Kupffer cell responses from these animals demonstrated a significant increase in several inflammatory mediators, and Kupffer cell-associated LBP appears to be responsible for these differences, at least in part. Our results indicate that the role of LBP signaling in inflammatory conditions is complex and heterogeneous, and elevated levels of LBP are not always protective. Increased LBP production in the setting of cholestatic liver disease appears to be deleterious and may represent a potential therapeutic target for preventing overwhelming inflammatory responses to LPS in this setting.

Relationship of serum fibrosis markers with liver fibrosis stage and collagen content in patients with advanced chronic hepatitis C

This study determined the utility of a panel of serum fibrosis markers along with routine laboratory tests in estimating the likelihood of histological cirrhosis in a cohort of prior nonresponders with chronic hepatitis C. The relationship between serum markers and quantitative hepatic collagen content was also determined. Liver biopsy samples from 513 subjects enrolled in the HALT-C trial were assigned Ishak fibrosis scores. The collagen content of 386 sirius-red stained, nonfragmented biopsy samples was quantified using computerized morphometry. Serum tissue inhibitor of matrix metalloproteinase-1 (TIMP-1), amino-terminal peptide of type III procollagen (PIIINP), hyaluronic acid (HA), and YKL-40 levels were determined using commercially available assays.Sixty-two percent of patients had noncirrhotic fibrosis (Ishak stage 2-4) whereas 38% had cirrhosis (Ishak stage 5,6). Multivariate analysis identified a 3-variable model (HA, TIMP-1, and platelet count) that had an area under the receiver operating curve (AUROC) of 0.81 for estimating the presence of cirrhosis. This model was significantly better than that derived from the cirrhosis discriminant score (AUROC 0.70), the AST-to-platelet ratio (AUROC 0.73), and a prior model developed in HALT-C patients (AUROC 0.79). Multivariate analysis demonstrated that the serum fibrosis markers correlated substantially better with Ishak fibrosis scores than with the log hepatic collagen content (AUROC 0.84 versus 0.72).

CONCLUSION

A 3-variable model consisting of serum HA, TIMP-1, and platelet count was better than other published models in identifying cirrhosis in HALT-C Trial subjects. The stronger correlation of the serum markers with Ishak scores suggests that serum fibrosis markers reflect the pattern of fibrosis more closely than the quantity of hepatic collagen.

Pregnancy and liver disease

Although liver disease does not occur frequently during pregnancy, when it does, it can cause significant morbidity and mortality for both fetus and mother. Recent advances in molecular genetics have provided some insight into the pathogenesis of diseases such as intrahepatic cholestasis of pregnancy (IHCP) and acute fatty liver of pregnancy. Newer studies linking serum bile acid levels with fetal outcome support the importance of this marker in IHCP. Randomized trials with ursodeoxycholic acid have shown promising results in reducing maternal symptoms and serum bile acid levels in IHCP. Although further studies must be performed, early strategies aimed at reducing viral loads in mothers may reduce perinatal transmission of hepatitis B.

Attenuating burn wound inflammation improves pulmonary function and survival in a burn-pneumonia model

OBJECTIVE

We previously showed that topical inhibition of inflammatory signaling in burn wounds reduced systemic inflammatory response and burn-induced pulmonary inflammation. We hypothesized that this topical intervention would attenuate burn-induced lung injury, improve pulmonary function, protect lungs from bacterial invasion, and reduce mortality.

DESIGN

Controlled, in vivo, laboratory study.

SETTING

University laboratory.

SUBJECTS

Female mice, 8-10 wks old.

INTERVENTIONS

Animals received 30% total body surface area burn followed by topical application of a specific inhibitor of p38 mitogen-activated protein kinase, a key inflammatory signaling pathway, or vehicle to the wound. Twenty-four hours after injury, pulmonary collagen deposition and pulmonary function were assessed. One day postburn, some of the animals received intratracheal instillation of Klebsiella pneumoniae and were subsequently monitored for 7 days.

MEASUREMENTS AND MAIN RESULTS

Topical inhibition of p38 mitogen-activated protein kinase significantly decreased pulmonary collagen deposition and prevented a decline in pulmonary function at 1 day after burn injury. Compared with sham controls, animals with burn injury had a significantly higher mortality in response to intratracheal bacterial challenge. Application of p38 mitogen-activated protein kinase inhibitor to the burn wound attenuated pulmonary neutrophil infiltration and reduced the mortality rate to a level experienced by sham controls.

CONCLUSIONS

Inflammatory source control in burn wounds with topical p38 mitogen-activated protein kinase inhibition attenuates acute lung injury, avoids pulmonary dysfunction, protects lungs from bacterial challenge, and improves survival.

C5a-blockade improves burn-induced cardiac dysfunction

We previously reported that generation of the anaphylatoxin C5a is linked to the development of cardiac dysfunction in sepsis due to C5a interaction with its receptor (C5aR) on cardiomyocytes. Burn injury involves inflammatory mechanisms that can lead to C5a generation as well. In this study, we investigated the effects of C5a blockade on burn-induced cardiac dysfunction. Using a standardized rat model of full thickness scald injury, left ventricular pressures were recorded in vivo followed by in vitro assessment of sarcomere contraction of single cardiomyocytes. Left ventricular pressures in vivo and cardiomyocyte sarcomere contractility in vitro were significantly reduced following burn injury. In the presence of anti-C5a Ab, these defects were greatly attenuated 1, 6, and 12 h after burn injury and completely abolished 24 h after burn. In vitro incubation of cardiomyocytes with bacterial LPS accentuated the impaired contractility, which was partially prevented in cardiomyocytes from burned rats that had received an anti-C5a Ab. Based on Western blot analyses, real-time PCR, and immunostaining of left ventricular heart tissue, there was a significant increase in cardiomyocyte expression of C5aR after burn injury. In conclusion, an in vivo blockade of C5a attenuates burn-induced cardiac dysfunction. Further deterioration of contractility due to the exposure of cardiomyocytes to LPS was partially prevented by C5a-blockade. These results suggest a linkage between C5a and burn-induced cardiac dysfunction and a possible contribution of LPS to these events.

Sustained virologic response to therapy of recurrent hepatitis C after liver transplantation is related to early virologic response and dose adherence

Sustained virologic response (SVR) after antiviral therapy for recurrent hepatitis C virus (HCV) infection in liver transplant (LT) recipients is consistently lower than that achieved in non-LT patients. We evaluated efficacy and safety of pegylated interferon (IFN) and ribavirin (RBV) therapy in LT recipients with recurrent HCV and factors associated with SVR. All subjects with histologic evidence of recurrent HCV were intended to be treated for 48 weeks with full-dose pegylated IFN; target dose of RBV was 800 mg/day. Thirty-five LT recipients with recurrent HCV, median age 48.5 years, 77% genotype 1, and median pretreatment HCV RNA 6.4 log10 IU/mL were treated between January 2000 and February 2006. Antiviral therapy was discontinued prematurely in 15 subjects as a result of adverse events. Median overall treatment duration was 46 weeks. Early virologic response at week 12 was seen in 17 (49%) and an end-of-treatment virological response in 19 (54%) patients. SVR was achieved in 13 patients (37%), and all 9 patients followed for >1 year after treatment had durable response. Patients with SVR had significantly lower pretreatment HCV RNA (5.7 vs. 6.5 log10 IU/mL, P=0.003), more likely to have a week 12 virological response (85% vs. 27%, P=0.0009) and received higher cumulative doses of pegylated IFN (75% vs. 33%, P=0.029) and RBV (90% vs. 26%, P=0.016) compared with patients whose disease did not respond to therapy. In conclusion, SVR was achieved in 37% of patients with recurrent hepatitis C after LT. Similar to non-LT patients, those with lower pretreatment HCV RNA, a week 12 virological response, and pegylated IFN and RBV dose adherence were more likely to achieve SVR.

Risk factors for hepatocellular carcinoma may impair the performance of biomarkers: a comparison of AFP, DCP, and AFP-L3

Current surveillance strategies for hepatocellular carcinoma (HCC) are applied uniformly in patients with cirrhosis, regardless of their cancer risk. The aim of this study was to compare the performance characteristics of the biomarkers alpha-fetoprotein (AFP), des-gamma carboxyprothrombin (DCP), and lectin-bound AFP (AFP-L3) in the diagnosis of HCC, and to determine the effect of risk factors for HCC on test performance. Eighty-four patients with HCC and 169 patients with cirrhosis were enrolled and their serum analyzed for total AFP, AFP-L3 and DCP. Receiver-operating characteristic (ROC) curves were constructed to determine the performance characteristics. DCP was significantly better than total AFP or AFP-L3 in differentiating HCC from cirrhosis, with a sensitivity of 86% and specificity of 93%. When subjects were divided into two groups by their risk for HCC, all 3 markers had a lower sensitivity and area under the ROC curve in the high-risk group compared to the low-risk group. In conclusion, DCP has the best performance characteristics of all 3 serum markers for the diagnosis of HCC. Serum biomarkers may be less sensitive and specific in the highest risk patients.

Topical p38 MAPK inhibition reduces bacterial growth in an in vivo burn wound model

BACKGROUND

Although the inflammatory response is a prerequisite for wound healing, excessive activation of the innate immune system can induce epithelial cell damage and apoptosis, which may further compromise dermal integrity. In a noninfectious burn wound model, we previously demonstrated that topical inhibition of p38 MAPK, an important inflammatory signaling pathway, attenuated epithelial cell damage and apoptosis. We now question whether attenuating local inflammation would weaken bacterial wound resistance and compromise host defense.

METHODS

Rats received 30% total body surface area burn, and the wound was treated with topical application of a p38 MAPK inhibitor or vehicle. At 24 hours after injury, burn wounds were inoculated with Pseudomonas aeruginosa. At 48 hours postinjury, animals were sacrificed, and the burn wound was analyzed.

RESULTS

Inoculating burn wounds induced significant bacterial growth. Dermal inflammatory changes were markedly accentuated in the inoculated animals. Topical p38 MAPK inhibition reduced the proinflammatory cytokine expression in the burn wounds and neutrophil sequestration with or without bacterial inoculation. Interestingly, the bacterial wound growth was significantly attenuated in animals treated with topical p38 MAPK inhibitor.

CONCLUSIONS

Topical p38 MAPK inhibition attenuated wound inflammation without interfering with bacterial host defense. Attenuation of excessive burn wound inflammatory signaling may prevent secondary damage of the dermal barrier and reduce the growth of opportunistic pathogens.

Attenuating burn wound inflammatory signaling reduces systemic inflammation and acute lung injury

The relationship between local inflammation and the subsequent systemic inflammatory response is poorly described. In a burn injury model, the dermal inflammatory response may act as an ongoing trigger for the systemic inflammatory response syndrome (SIRS) and subsequent systemic complications. We hypothesized that topical attenuation of burn wound inflammatory signaling will control the dermal inflammatory source, attenuate SIRS, and reduce acute lung injury. Mice received a 30% total body surface area burn. Subgroups were treated with specific p38 MAPK inhibitor or vehicle, which was topically applied to wounds. Topical p38 MAPK inhibition significantly reduced burn wound inflammatory signaling and subsequent systemic expression of proinflammatory cytokines and chemokines. In vitro macrophage functional assays demonstrated a significant attenuation in serum inflammatory mediators from animals receiving the topical inhibitor. Topical p38 MAPK inhibition resulted in significantly less pulmonary inflammatory response via reduction of pulmonary neutrophil sequestration, pulmonary cytokine expression, and a significant reduction in pulmonary microvascular injury and edema formation. Although dermal activating transcription factor-2, a downstream p38 MAPK target, was significantly reduced, there was no reduction in pulmonary activating transcription factor-2 expression, arguing against significant systemic absorption of the topical inhibitor. These experiments demonstrate a strong interaction between dermal inflammation and systemic inflammatory response. Attenuating local inflammatory signaling appears effective in reducing SIRS and subsequent systemic complications after burn injury.

Topical p38MAPK inhibition reduces dermal inflammation and epithelial apoptosis in burn wounds

Thermal injury induces dermal inflammatory and proapoptotic signaling. These phenomena extend burn wound size and trigger a systemic inflammatory response, factors known to adversely affect outcomes. p38MAPK is known to trigger inflammatory responses and induce epithelial proapoptotic genes. We hypothesize that topical p38MAPK inhibition will attenuate excessive inflammatory and apoptotic signaling and reduce dermal tissue loss. Rats were given a 30% total body surface area partial thickness burn or sham injury. Some of the animals were treated with a p38MAPK inhibitor or vehicle, which was applied directly to the wound. Dermal inflammation was investigated with enzyme-linked immunosorbent assay, reverse transcriptase polymerase chain reaction, myeloperoxidase assay, and Evans blue extravasation. Apoptotic changes were detected using terminal deoxynucleotidyl transferase dUTP nick-end labeling assay and Caspase-3 in situ staining. Burn injury activated dermal p38MAPK and induced a significant rise in dermal IL-6, TNF-alpha, and IL-1beta expression. Neutrophil sequestration, microvascular damage, and hair follicle apoptosis were significantly elevated after injury. Topical p38MAPK inhibition significantly attenuated downstream dermal p38MAPK targets, proinflammatory cytokine expression, neutrophil sequestration, and microvascular injury. A significant reduction in hair follicle apoptosis was seen. This study demonstrates the attenuation of burn-induced cellular stress by topical application of p38MAPK inhibitors. Blunting early excessive inflammatory signaling may be an efficient strategy to improve patient outcomes after burn injury.

Gene therapy with lipopolysaccharide binding protein for gram-negative pneumonia: respiratory physiology

BACKGROUND

Lipopolysaccharide binding protein (LBP) plays an essential role in the pulmonary immune response to gram-negative bacterial infection. LBP knockout mice with gram-negative pneumonia have increased mortality compared with wild-type controls. This mortality difference can be abolished with systemic LBP gene therapy. We postulate that LBP knockout mice will develop derangements in lung physiology from gram-negative pneumonia and that these changes can be reversed with systemic LBP gene therapy.

METHODS

Twelve- to 16-week-old C57BL/6 wild-type mice and/or sex, age, matched LBP knockout mice were administered 1 x 10(3) colony-forming units/mouse of Klebsiella pneumoniae by intratracheal inoculation. Treated mice were administered 5 x 10(9) plaque-forming units of recombinant adenovirus containing either the gene for LBP or the irrelevant control protein beta-galactosidase by intravenous injection 2 days before bacterial inoculation. Respiratory physiology parameters were measured preinoculation and 24 hours postbacterial inoculation.

RESULTS

Administration of LBP by systemic gene therapy to LBP knockout mice improved 7-day survival from Klebsiella pneumonia to a level equivalent to wild-type mice exposed to the same dose of bacteria (42 vs. 43% survival). LBP knockout mice given the LBP gene therapy demonstrated increased 14-day survival from Klebsiella pneumonia when compared with controls treated with beta-galactosidase (28 vs. 0%, p < 0.001). LBP knockout mice developed significant differences in respiratory rate, minute ventilation, and enhanced pause (Penh), when compared with wild-type mice with Klebsiella pneumonia. These respiratory derangements were prevented with adenoviral delivery of the LBP gene before K. pneumoniae inoculation.

CONCLUSIONS

Gram-negative pneumonia produces measurable changes in mortality and respiratory physiology between wild-type and LBP knockout mice. These changes can be prevented in LBP knockout mice by systemic gene therapy to restore innate immunity.

Immune thrombocytopenic purpura following liver transplantation: a case series and review of the literature

Thrombocytopenia is common among liver transplant candidates and recipients. The aim of our study was to determine the incidence and outcome of new-onset immune-mediated thrombocytopenic purpura (ITP) following liver transplantation at a single center. Among the 256 liver transplant recipients with an International Classification of Diseases, Ninth Edition code for thrombocytopenia, 8 cases of new-onset ITP were identified, leading to an overall incidence of 0.7% in 1,105 consecutive liver transplant recipients over a 15-year period. All 8 patients were Caucasian, 5 (63%) were male, and the median age at ITP onset was 54 years (range, 15-63). The median platelet count at presentation was 3,500 cells/mL (range, 1,000-12,000) and liver disease was due to hepatitis C (38%), primary sclerosing cholangitis (38%), and cryptogenic cirrhosis (25%). The median time from transplant to ITP onset was 53.5 months (range, 1.9-173). Three of the 6 patients tested (50%) had cell-bound antiplatelet antibodies, 1 patient had an underlying hematological malignancy, and none of the organ donors had a history of ITP. Corticosteroids and/or immunoglobulin infusions were effective in 4 patients. However, serial rituximab infusions were required in 4 patients with persistent thrombocytopenia, and 3 of them eventually required splenectomy to induce disease remission. At a median follow-up of 19.7 months, 7 long-term survivors remain in remission with a median platelet count of 267,000 cells/mL. In conclusion, new-onset ITP is an infrequent but important cause of severe thrombocytopenia in liver transplant recipients. Corticosteroids and immunoglobulin infusions were effective in 50% while the remainder of patients required rituximab infusions or eventual splenectomy for long-term disease remission.

XIAP Is a Copper Binding Protein Deregulated in Wilson's Disease and Other Copper Toxicosis Disorders

X-linked inhibitor of apoptosis (XIAP), known primarily for its caspase inhibitory properties, has recently been shown to interact with and regulate the levels of COMMD1, a protein associated with a form of canine copper toxicosis. Here, we describe a role for XIAP in copper metabolism. We find that XIAP levels are greatly reduced by intracellular copper accumulation in Wilson's disease and other copper toxicosis disorders and in cells cultured under high copper conditions. Elevated copper levels result in a profound, reversible conformational change in XIAP due to the direct binding of copper to XIAP, which accelerates its degradation and significantly decreases its ability to inhibit caspase-3. This results in a lowering of the apoptotic threshold, sensitizing the cell to apoptosis. These data provide an unsuspected link between copper homeostasis and the regulation of cell death through XIAP and may contribute to the pathophysiology of copper toxicosis disorders.

CARDIOMYOCYTE FUNCTION AFTER BURN INJURY AND LIPOPOLYSACCHARIDE EXPOSURE: SINGLE-CELL CONTRACTION ANALYSIS AND CYTOKINE SECRETION PROFILE

A component of multiorgan dysfunction in burned patients is heart failure. Burn trauma induces cytokine synthesis of interleukin (IL) 1beta, IL-6, and tumor necrosis factor alpha (TNF-alpha) which can negatively impact cardiac function. Infectious complications are common following severe burn injury. We hypothesized that burn injury and lipopolysaccharide (LPS) exposure independently influence peak cardiomyocyte contraction and cytokine secretion. Rats underwent a full-thickness 30% total body surface area scald or sham burn. At 1, 6, 12, and 24 h after burn, cardiomyocytes were isolated and incubated with increasing LPS doses. Peak sarcomere shortening and contractile velocity parameters were recorded using a variable-rate video camera with sarcomere length detection software. Supernatants were assayed for IL-1beta, IL-6, and TNF-alpha by ELISA. Peak sarcomere shortening was decreased in the burn group at 1, 6, 12, and 24 h after burn. IL-1beta, IL-6, and TNF-alpha levels were increased in cardiomyocytes isolated 1 h after burn compared with sham controls, but returned to sham levels at 6, 12, and 24 h after burn. LPS exposure caused dose-dependent decreases in sarcomere shortening in sham and burn animals. LPS exposure did not produce increased cardiomyocyte cytokine expression. Burn injury diminished peak sarcomere shortening. Whereas exposure to LPS did not have an effect on cardiomyocyte cytokine expression, LPS significantly inhibited sarcomere shortening in a dose-dependent fashion. Combined burn and LPS exposure inhibited sarcomere shortening more than each alone. These results demonstrate that LPS exposure and burn injury independently decrease peak cardiac shortening. These decreases did not directly correlate with the levels of cytokines released in response to each stressor.

An essential role for complement C5a in the pathogenesis of septic cardiac dysfunction

Defective cardiac function during sepsis has been referred to as “cardiomyopathy of sepsis.” It is known that sepsis leads to intensive activation of the complement system. In the current study, cardiac function and cardiomyocyte contractility have been evaluated in rats after cecal ligation and puncture (CLP). Significant reductions in left ventricular pressures occurred in vivo and in cardiomyocyte contractility in vitro. These defects were prevented in CLP rats given blocking antibody to C5a. Both mRNA and protein for the C5a receptor (C5aR) were constitutively expressed on cardiomyocytes; both increased as a function of time after CLP. In vitro addition of recombinant rat C5a induced dramatic contractile dysfunction in both sham and CLP cardiomyocytes, but to a consistently greater degree in cells from CLP animals. These data suggest that CLP induces C5aR on cardiomyocytes and that in vivo generation of C5a causes C5a–C5aR interaction, causing dysfunction of cardiomyocytes, resulting in compromise of cardiac performance.

Hepatocytes enhance effects of lipopolysaccharide on liver nonparenchymal cells through close cell interactions

The response to lipopolysaccharide (LPS) in the liver is complex, requiring cell-to-cell interactions between hepatocytes and liver nonparenchymal cells (NPC), in particular, Kupffer cells. Previous studies show that cytokines produced by Kupffer cells stimulated with LPS can, in turn, activate hepatocytes. In the present study, we sought to examine whether the reverse, hepatocyte (HC)-NPC interactions, is important in cytokine production in mixed cell cocultures. LPS-stimulated production of tumor necrosis factor (TNF)-alpha and interleukin (IL)-6 from NPC was augmented in mixed HC-NPC cocultures, as compared with NPC monocultures. This HC-NPC interaction was not observed when hepatocytes were cocultured with NPC from TLR4-mutant (C3H/HeJ) mice or CD14-deficient mice. The effect was partially lost when hepatocytes from lipopolysaccharide-binding protein (LBP)-deficient mice were cocultured with wild-type mice. These data indicate that functional TLR4 and CD14 are required for NPC production of cytokines and that at least one of the critical components from hepatocytes is LBP. The augmented cytokine production by mixed HC-NPC cocultures was abrogated when the cells were separated by a filter system, indicating that close cell interactions are also required for this interaction. Thus, interaction between hepatocytes and NPC are critical for cytokine secretion by NPC.

Improved survival in mice given systemic gene therapy in a gram negative pneumonia model

BACKGROUND

We previously demonstrated an essential role for lipopolysaccharide binding protein (LBP) in the pulmonary immune response to Gram-negative bacterial infection. LBP knockout mice had significantly higher mortality, greater rates of bacteremia, and higher counts of viable bacteria in their lungs at sacrifice compared with wild-type controls. We postulate that systemic LBP gene therapy will reconstitute a protective innate immune response in LBP knockout mice and that overexpression of LBP in wild-type mice may offer a survival advantage.

METHODS

12-16 week old female C57BL/6 wild-type mice and age matched LBP knockout mice were given 5 x 10(9) PFU of recombinant adenovirus containing either the gene for LBP or the irrelevant control protein beta-galactosidase by tail vein injection. 72 hours later each mouse was administered 1 x 10(3) CFU of Klebsiella pneumoniae by intratracheal injection.

RESULTS

Administration of LBP by systemic gene therapy to LBP knockout mice improved survival from Klebsiella pneumonia to a level equivalent or better than wild-type mice exposed to the same dose of bacteria (36 versus 25%). Wild-type mice given the LBP gene therapy demonstrated increased 7 day survival from Klebsiella pneumonia when compared with controls treated with beta-galactosidase (68 versus 30%, p = 0.03).

CONCLUSIONS

Systemic gene therapy with intravenous adenoviral vector transfer of LBP significantly improves survival in LBP knockout mice. Overexpression of LBP in wild-type mice improves survival from Klebsiella pneumonia. Raising levels of LBP in the setting of Gram-negative pneumonia may be of therapeutic benefit.