Detailed Description of Change in Serum Cholesterol Profile with Incremental Weight Loss After Restrictive Bariatric Surgery.

INTRODUCTION: Dyslipidemia affects up to 75% of morbidly obese individuals and is a key driver of cardiovascular disease. Weight loss is an established strategy to improve metabolic risk, including dyslipidemia. We aimed to determine weight loss goals for resolution of serum lipid abnormalities, by measuring improvements during progressive weight loss in obese individuals. METHODS: We performed a prospective cohort study of obese individuals with the metabolic syndrome undergoing adjustable gastric banding. Lipid levels were monitored monthly for 9 months, then three monthly until 24 months. RESULTS: There were 101 participants included, age 47.4 ± 10.9 years with body mass index 42.6 ± 5.9 kg/m2. At 24 months, total body weight loss (TBWL) was 18.3 ± 7.9%. This was associated with significant improvements in high-density lipoprotein (HDL) (1.18 vs 1.47, p < 0.001), triglyceride (2.0 vs 1.4, p < 0.001), and total cholesterol to HDL ratio (TC:HDL) (4.6 vs 3.6, p < 0.001). Over this time, progressive and linear improvements in HDL, triglycerides, and TC:HDL were seen with incremental weight loss (observed at 2.5% TBWL intervals). Significant improvements occurred after a threshold weight loss of 7.5-12.5% TBWL was achieved, with odds ratio (OR) 1.48-2.50 for normalization. These odds improved significantly with increasing weight loss (OR 18.2-30.4 with > 25% TBWL). Despite significant weight loss, there was no significant change in low-density lipoprotein (LDL). CONCLUSION: Significant improvements in triglycerides, HDL, and TC:HDL occur after 7.5-12.5% TBWL, with ongoing benefit after greater weight loss. LDL needs to be addressed independently, as this was not observed to respond to weight loss alone. TRIAL REGISTRATION NUMBER: Australian Clinical Trials Registry (ACTRN12610000049077).

Effects of Bariatric Surgery on Liver Function Tests in Patients with Nonalcoholic Fatty Liver Disease.

OBJECTIVES: Nonalcoholic fatty liver disease (NAFLD) affects over 80% of obese patients and is fueled by the metabolic syndrome. Weight loss is strongly advocated as a central treatment for NAFLD and has been shown to induce histological improvement. We aimed to define the patterns of improvement in NAFLD with weight loss and determine target weight goals for NAFLD resolution. METHODS: A prospective study of 84 morbidly obese patients with NAFLD undergoing bariatric surgery was conducted. Intraoperative liver biopsies were taken. Monthly follow-up, including blood tests and measurements, was performed. We monitored improvements in NAFLD by monthly alanine aminotransferase (ALT) and gamma glutamyltransferase (GGT) levels over 1 year. RESULTS: There was rapid improvement in ALT, particularly in the first 6 months following surgery, with statistically significant reduction in ALT at 2 months (35 vs 27 IU/L, p < 0.001). In multivariate analysis, there were significantly increased odds of ALT normalization after a %TBWL of 10-15% (odds ratio 2.49, p = 0.005). The odds of resolution increased with increasing weight loss. Triglyceride levels (odds ratio 0.59, p = 0.021) and baseline NAFLD activity score (odds ratio 0.28, p < 0.001) were also significantly related to ALT normalization. Improvements in ALT occurred prior to metabolic improvement and well before traditional ideal weight goals were reached. CONCLUSION: Improvements in NAFLD occurred rapidly after bariatric surgery and were closely related to weight loss and metabolic factors. A 10-15% reduction in body weight is an appropriate target to achieve substantial improvement in ALT levels. TRIAL REGISTRATION NUMBER: Australian Clinical Trials Registry (ACTRN12610000049077).

Modified thresholds for fibrosis risk scores in nonalcoholic fatty liver disease are necessary in the obese.

BACKGROUND: Obesity and its related comorbidities are significant risk factors for nonalcoholic fatty liver disease (NAFLD). Liver fibrosis is the major determinant of long-term outcomes in NAFLD. A non-invasive tool that accurately identifies obese patients at elevated risk of liver fibrosis would be of significant value. Fibrosis risk scores in patients with NAFLD have been proposed but have not been validated in obese populations. We aimed to validate established simple fibrosis scores in bariatric surgical patients. METHODS: We conducted a prospective study of 107 consecutive high-risk obese patients undergoing primary bariatric surgery. Proposed fibrosis scores (NAFLD fibrosis score; body mass index (BMI), aspartate aminotransferase (AST)/alanine aminotransferase ratio (ALT), and diabetes (BARD); Fibrosis-4 (FIB-4); Forn; and AST to platelet ratio index) were calculated and compared hepatic fibrosis determined by histology of intraoperative liver biopsies. Accuracy was determined, and fibrosis score thresholds were optimized. These modified thresholds were then validated in an independent bariatric surgical population. RESULTS: Liver biopsies were available in 101 patients. Sixty-eight patients had some degree of fibrosis, with 23 patients (23 %) having significant fibrosis (F2-4). The Forn score best predicted significant fibrosis (area under the receiver operator characteristic curve (AUROC) 0.724, p = 0.001). With standard thresholds, the sensitivity for the Forn score for identification of significant fibrosis (F2-4) was 0 %. Using modified thresholds of 3.5, the sensitivity and negative predictive value increased to 85.7 and 94.7 %. This threshold was applied to an independent validation cohort with good accuracy. CONCLUSIONS: Fibrosis risk scores using simple markers have moderate success at delineating obese patients with significant NAFLD-related fibrosis. Thresholds, however, need to be lowered to maximize diagnostic accuracy in this cohort.

Role of heme oxygenase-1 in the pathogenesis and tumorigenicity of Kaposi's sarcoma-associated herpesvirus.

Kaposi's Sarcoma-associated Herpesvirus (KSHV) is the etiologic agent of several malignancies, including Kaposi's Sarcoma (KS), which preferentially arise in immunocompromised patients such as HIV+ subpopulation and lack effective therapeutic options. Heme oxygenase-1 (HO-1) has been reported as an important regulator of endothelial cell cycle control, proliferation and angiogenesis. HO-1 has also been found to be highly expressed in KSHV-infected endothelial cells and oral AIDS-KS lesions. We previously demonstrate that the multifunctional glycoprotein CD147 is required for KSHV/LANA-induced endothelial cell invasiveness. During the identification of CD147 controlled downstream genes by microarray analysis, we found that the expression of HO-1 is significantly elevated in both CD147-overexpressing and KSHV-infected HUVEC cells when compared to control cells. In the current study, we further identify the regulation of HO-1 expression and mediated cellular functions by both CD147 and KSHV-encoded LANA proteins. Targeting HO-1 by either RNAi or the chemical inhibitor, SnPP, effectively induces cell death of KSHV-infected endothelial cells (the major cellular components of KS) through DNA damage and necrosis process. By using a KS-like nude mouse model, we found that SnPP treatment significantly suppressed KSHV-induced tumorigenesis in vivo. Taken together, our data demonstrate the important role of HO-1 in the pathogenesis and tumorigenesis of KSHV-infected endothelial cells, the underlying regulatory mechanisms for HO-1 expression and targeting HO-1 may represent a promising therapeutic strategy against KSHV-related malignancies.

Targeting HGF/c-MET induces cell cycle arrest, DNA damage, and apoptosis for primary effusion lymphoma.

Kaposi sarcoma-associated herpesvirus (KSHV) is a principal causative agent of primary effusion lymphoma (PEL) with a poor prognosis in immunocompromised patients. However, it still lacks effective treatment which urgently requires the identification of novel therapeutic targets for PEL. Here, we report that the hepatocyte growth factor (HGF)/c-MET pathway is highly activated by KSHV in vitro and in vivo. The selective c-MET inhibitor, PF-2341066, can induce PEL apoptosis through cell cycle arrest and DNA damage, and suppress tumor progression in a xenograft murine model. By using microarray analysis, we identify many novel genes that are potentially controlled by HGF/c-MET within PEL cells. One of the downstream candidates, ribonucleoside-diphosphate reductase subunit M2 (RRM2), also displays the promising therapeutic value for PEL treatment. Our findings provide the framework for development of HGF/c-MET-focused therapy and implementation of clinical trials for PEL patients.

Induction of hyaluronan production by oncogenic KSHV and the contribution to viral pathogenesis in AIDS patients.

Kaposi sarcoma-associated herpesvirus (KSHV) is the etiologic agent for Kaposi's sarcoma (KS) and primary effusion lymphoma (PEL), malignancies arising primarily in immunocompromised patients particularly AIDS-patients, which still lack effective therapy. Hyaluronan (HA) is a large glucuronic acid and has been found closely related to multiple functions in cancer cells, although its role in viral oncogenesis remains largely unknown. Here we provide first evidence that KSHV de novo infection induces HA production from primary endothelial cells through upregulation of HA synthase gene 1 (Has1) and a multifunctional glycoprotein, CD147. Further data demonstrate that KSHV-induced HA production requires viral latent protein, LANA (in particular functional domain A) and MAPK/ERK signaling activities. In functions, HA production is necessary for KSHV/LANA-induced primary endothelial cell invasion, a hallmark feature for KS development. For clinical relevance, our data indicate that the KSHV+ group has higher levels of HA and Has1 activities in its plasma than the KSHV- group of cohort HIV-infected patients. Together, our findings provide innovative insights into the mechanisms of oncogenic virus activation of HA production and its role in virus-associated malignancy pathogenesis, which may help to develop novel therapeutic strategies by targeting HA and related signaling.

Pro-inflammatory CD11c+CD206+ adipose tissue macrophages are associated with insulin resistance in human obesity.

OBJECTIVE: Insulin resistance and other features of the metabolic syndrome have been causally linked to adipose tissue macrophages (ATMs) in mice with diet-induced obesity. We aimed to characterize macrophage phenotype and function in human subcutaneous and omental adipose tissue in relation to insulin resistance in obesity. RESEARCH DESIGN AND METHODS: Adipose tissue was obtained from lean and obese women undergoing bariatric surgery. Metabolic markers were measured in fasting serum and ATMs characterized by immunohistology, flow cytometry, and tissue culture studies. RESULTS ATMs comprised CD11c(+)CD206(+) cells in "crown" aggregates and solitary CD11c(-)CD206(+) cells at adipocyte junctions. In obese women, CD11c(+) ATM density was greater in subcutaneous than omental adipose tissue and correlated with markers of insulin resistance. CD11c(+) ATMs were distinguished by high expression of integrins and antigen presentation molecules; interleukin (IL)-1beta, -6, -8, and -10; tumor necrosis factor-alpha; and CC chemokine ligand-3, indicative of an activated, proinflammatory state. In addition, CD11c(+) ATMs were enriched for mitochondria and for RNA transcripts encoding mitochondrial, proteasomal, and lysosomal proteins, fatty acid metabolism enzymes, and T-cell chemoattractants, whereas CD11c(-) ATMs were enriched for transcripts involved in tissue maintenance and repair. Tissue culture medium conditioned by CD11c(+) ATMs, but not CD11c(-) ATMs or other stromovascular cells, impaired insulin-stimulated glucose uptake by human adipocytes. CONCLUSIONS: These findings identify proinflammatory CD11c(+) ATMs as markers of insulin resistance in human obesity. In addition, the machinery of CD11c(+) ATMs indicates they metabolize lipid and may initiate adaptive immune responses.

Second primary oesophageal cancer following radiation for breast cancer.

The management of 12 women who presented with a second primary oesophageal cancer following radiotherapy for breast cancer was reviewed. It was concluded that nine cases fitted the classical description of a radiation-induced malignancy. Most cases were successfully managed with combined modality therapy in spite of their previous radiotherapy.