Effect of dietary branched chain amino acids on liver related mortality: Results from a large cohort of North American patients with advanced HCV infection

Branched chain amino acids (BCAA) supplementation may reduce the incidence of liver failure and hepatocellular carcinoma in patients with cirrhosis. We aimed to determine whether long-term dietary intake of BCAA is associated with liver-related mortality in a well-characterized cohort of North American patients with advanced fibrosis or compensated cirrhosis. We performed a retrospective cohort study using extended follow-up data from the Hepatitis C Antiviral Long-term Treatment against Cirrhosis (HALT-C) Trial. The analysis included 656 patients who completed two Food Frequency Questionnaires. The primary exposure was BCAA intake measured in grams (g) per 1000 kilocalories (kcal) of energy intake (range 3.0-34.8 g/1000 kcal). During a median follow-up of 5.0 years, the incidence of liver-related death or transplantation was not significantly different among the four quartiles of BCAA intake before and after adjustment of confounders (AHR 1.02, 95% CI 0.81-1.27, P-value for trend = 0.89). There remains no association when BCAA was modeled as a ratio of BCAA to total protein intake or as absolute BCAA intake. Finally, BCAA intake was not associated with the risk of hepatocellular carcinoma, encephalopathy or clinical hepatic decompensation. We concluded that dietary BCAA intake was not associated with liver-related outcomes in HCV-infected patients with advanced fibrosis or compensated cirrhosis. The precise effect of BCAA in patients with liver disease warrants further study.

Gastrokine-1, an anti-amyloidogenic protein secreted by the stomach, regulates diet-induced obesity

Obesity and its sequelae have a major impact on human health. The stomach contributes to obesity in ways that extend beyond its role in digestion, including through effects on the microbiome. Gastrokine-1 (GKN1) is an anti-amyloidogenic protein abundantly and specifically secreted into the stomach lumen. We examined whether GKN1 plays a role in the development of obesity and regulation of the gut microbiome. Gkn1-/- mice were resistant to diet-induced obesity and hepatic steatosis (high fat diet (HFD) fat mass (g) = 10.4 ± 3.0 (WT) versus 2.9 ± 2.3 (Gkn1-/-) p < 0.005; HFD liver mass (g) = 1.3 ± 0.11 (WT) versus 1.1 ± 0.07 (Gkn1-/-) p < 0.05). Gkn1-/- mice also exhibited increased expression of the lipid-regulating hormone ANGPTL4 in the small bowel. The microbiome of Gkn1-/- mice exhibited reduced populations of microbes implicated in obesity, namely Firmicutes of the class Erysipelotrichia. Altered metabolism consistent with use of fat as an energy source was evident in Gkn1-/- mice during the sleep period. GKN1 may contribute to the effects of the stomach on the microbiome and obesity. Inhibition of GKN1 may be a means to prevent obesity.

Midgut Neuroendocrine Tumors with Liver-only Metastases: Benefit of Primary Tumor Resection

BACKGROUND

Management of metastatic midgut neuroendocrine tumors (MNET) remains controversial. The benefits of resecting the primary tumor are not clear and advocated only for select patients. This study aimed to determine whether resection of the primary MNET in patients with untreated liver-only metastases has an impact on survival.

METHODS

This retrospective study reviewed data of the National Cancer Database from 2004 to 2015 for patients with liver-only metastatic MNETs and compared those who received resection of their primary MNET with those who did not. Patient demographics, tumor characteristics, and clinical outcomes were compared between the groups. The primary outcome was overall survival (OS) after adjustment for patient, demographic, and tumor-related factors.

RESULTS

The study identified 1952 patients with a median age of 63 years (range, 18-90 years). The median primary tumor size was 2.4 cm (range, 0.1-20 cm). Of these patients, 1295 (66%) underwent resection of the primary tumor and 667 (34%) did not. The patients who underwent resection were younger (median age, 63 vs 65 years; p < 0.001) and had smaller primary tumors (median, 2.3 vs 3.0 cm; p < 0.001). The patients with clinical T1 or T2 tumors were significantly less likely to undergo resection than those with stage T3 or T4 tumors (58.5% vs 89.7%; p < 0.001). The median follow-up period was 43 months (range, 1-83 months). In the entire cohort, 483 deaths occurred, with a 5-year OS of 61%. The 5-year OS rate was 49% for the patients who underwent resection and 66% for those who did not (p < 0.001). When the patients were grouped according to T stage, no OS difference between resection and no resection for stages T1 (p = 0.07) and T2 (p = 0.40) was identified. However, the 5-year OS rate was significantly better for the resected patient cohort with T3 (67.5% vs 37.2%; p < 0.001) or T4 (59.8% vs 21.5%; p < 0.001) tumors.

CONCLUSIONS

The patients with treatment-naïve liver-only metastatic MNET had improved OS when the primary tumor was resected, particularly those with clinical stage T3 or T4 tumors. These patients may benefit from surgical resection of their primary tumor.

Socioeconomic disparities and outcomes in midgut neuroendocrine tumors

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Background: Demographic and socioeconomic disparities have been shown to effect cancer specific outcomes in numerous malignancies but the effect in midgut neuroendocrine tumors (mNETs) is unknown. We sought to investigate whether these factors are associated with survival in mNETs. Methods: The NCDB was queried to identify patients with mNETs between 2004 and 2015. Only patients treated at a single hospital with complete data were included. Overall Survival (OS) was compared based on demographic data, socioeconomic factors, insurance status and place of living. Results: A total of 14,083 patients were identified with a mean age of 72 years (range 18-90). The majority of patients were Caucasian (83.9%) and male (50.9%). Most patients had private insurance (50.5%) or medicare (41.3%). Patients typically lived in larger metropolitan areas (51.5%) and 60.7% lived in zip codes with median household incomes > $48,000. Only 14.7% lived in zip codes where > 20% did not graduate high school (no HSD). The majority were treated at community comprehensive cancer centers (43.8%) or academic/research centers (35.2%). Overall, 3358 (24.5%) presented with metastasis at diagnosis. The 5-year OS for the entire cohort was 78.5%. The 5-year survival was worse in patients with lower median income (73.8% [ < $38,000] vs 81.5% [ > $63,000],p < 0.0001), lower education (74.9% [ > 20% no HSD] vs 80.7% [ < 7% no HSD], p < 0.0001), those not living in proximity to a metro area (73.8% [not metro adjacent] vs 78.7% [metro/adjacent], p = 0.0004) and those treated at a community cancer center (73.6% [community] vs. 80.1% [academic], p < 0.0001). Factors predictive of worse OS were lower income ( < $38,000) (HR 1.16, 95% CI 1.04-1.28), lower education ( > 20% no HSD) (HR 1.14, 95% CI 1.02-1.26), no insurance (HR 1.66, 95% CI 1.33-2.06) and not living in proximity to a metro area (HR 1.27, 95% CI 1.10-1.47). Conclusions: Socioeconomic factors shown to have worse OS in patients with mNETs were lower median income, lower education, treatment at a community cancer center and not living in proximity to a metro area. Patient demographic and socioeconomic factors play an important role in OS for patients with mNETs and access to care must be considered in this subpopulation of cancer patients.

Randomized Trial of Medical versus Surgical Treatment for Refractory Heartburn

BACKGROUND

Heartburn that persists despite proton-pump inhibitor (PPI) treatment is a frequent clinical problem with multiple potential causes. Treatments for PPI-refractory heartburn are of unproven efficacy and focus on controlling gastroesophageal reflux with reflux-reducing medication (e.g., baclofen) or antireflux surgery or on dampening visceral hypersensitivity with neuromodulators (e.g., desipramine).

METHODS

Patients who were referred to Veterans Affairs (VA) gastroenterology clinics for PPI-refractory heartburn received 20 mg of omeprazole twice daily for 2 weeks, and those with persistent heartburn underwent endoscopy, esophageal biopsy, esophageal manometry, and multichannel intraluminal impedance-pH monitoring. If patients were found to have reflux-related heartburn, we randomly assigned them to receive surgical treatment (laparoscopic Nissen fundoplication), active medical treatment (omeprazole plus baclofen, with desipramine added depending on symptoms), or control medical treatment (omeprazole plus placebo). The primary outcome was treatment success, defined as a decrease of 50% or more in the Gastroesophageal Reflux Disease (GERD)-Health Related Quality of Life score (range, 0 to 50, with higher scores indicating worse symptoms) at 1 year.

RESULTS

A total of 366 patients (mean age, 48.5 years; 280 men) were enrolled. Prerandomization procedures excluded 288 patients: 42 had relief of their heartburn during the 2-week omeprazole trial, 70 did not complete trial procedures, 54 were excluded for other reasons, 23 had non-GERD esophageal disorders, and 99 had functional heartburn (not due to GERD or other histopathologic, motility, or structural abnormality). The remaining 78 patients underwent randomization. The incidence of treatment success with surgery (18 of 27 patients, 67%) was significantly superior to that with active medical treatment (7 of 25 patients, 28%; P = 0.007) or control medical treatment (3 of 26 patients, 12%; P<0.001). The difference in the incidence of treatment success between the active medical group and the control medical group was 16 percentage points (95% confidence interval, -5 to 38; P = 0.17).

CONCLUSIONS

Among patients referred to VA gastroenterology clinics for PPI-refractory heartburn, systematic workup revealed truly PPI-refractory and reflux-related heartburn in a minority of patients. For that highly selected subgroup, surgery was superior to medical treatment. (Funded by the Department of Veterans Affairs Cooperative Studies Program; ClinicalTrials.gov number, NCT01265550.).

Small bowel tumors

Although rare, small bowel tumors may cause significant morbidity and mortality if left undetected. New endoscopic modalities allow full examination of the small bowel with improved diagnosis. However, isolated mass lesions may be missed by capsule endoscopy or incomplete balloon-assisted enteroscopy. Therefore the use of radiologic imaging and intraoperative enteroscopy for diagnosis should not be forgotten. Endoscopic resection of small bowel polyps and certain vascular tumors is possible but requires proper training. Advances in endoscopic tools are likely to broaden the endoscopic management of small bowel tumors. This article describes the general features of small bowel tumors, clinical presentation, and diagnostic tests followed by a description of the more common tumor types and their management.

The importance of recognizing increased cecal inflammation in health and avoiding the misdiagnosis of nonspecific colitis

BACKGROUND

An inherent degree of nonpathological mild inflammation in the cecum has been described informally among pathologists. This low-grade inflammation is often reported as "nonspecific colitis," which can confuse clinicians. Our objective was to characterize and quantify inflammatory changes in the cecum and rectum of healthy adults in a blinded study.

METHODS

A total of 85 adults free of gastrointestinal symptoms and history of disease underwent colonoscopy plus cecal and rectal biopsies as part of a case control study. Slides were scored independently by two observers. Histology scores 0 (none) to 3 (severe) were assigned for: epithelial injury, crypt architecture, lamina propria cellularity, subcryptal cellularity, and cryptitis. Slides were scored in a blinded fashion. Biopsy slides of cecum and rectum from fifteen patients with ulcerative colitis were randomly distributed within our sample to limit observer bias.

RESULTS

Scores for inflammation were greater in the cecum versus rectum for: epithelial injury (0.45 vs 0.26, P= 0.03), crypt architecture distortion (0.25 vs 0.09, P= 0.03), lamina propria cellularity (1.13 vs 0.34, P < 0.001), and cryptitis (0.40 vs 0.11, P < 0.001).

CONCLUSIONS

Increased microscopic inflammation of the cecum is present in healthy individuals, compared to the rectum. Caution should be used when describing "colitis" in cecal biopsies. Clinicians should be cautious in their response to biopsy reports identifying patients as having clinically significant "colitis" that is limited to the cecum.

Role of metallothionein in regulating the abundance of histochemically reactive zinc in rat tissues

The objectives of this study were (i) to investigate the modulating effects of zinc nutrition on histochemically reactive zinc in the rat intestine and liver and (ii) to assess the relationship between histochemically reactive zinc and metallothionein-bound zinc in these tissues under varying zinc nutrition. Male Wistar rats were fed a zinc-deficient (3 mg zinc/kg), adequate-zinc (30 mg zinc/kg, ad libitum or pair-fed), or zinc-supplemented (155 mg zinc/kg) diet for 2 or 6 weeks. Plasma N-(6-methoxy-8-quinolyl)-para-toluenesulfonamide-reactive zinc reflected dietary zinc intake. Abundance of the intestine histochemically reactive zinc was correlated with dietary zinc intake after 2 weeks of dietary treatment. Dietary zinc intake had no effect on the abundance of the intestine histochemically reactive zinc after 6 weeks of dietary treatment and the hepatic histochemically reactive zinc after both 2 and 6 weeks of dietary treatment. This lack of effect of dietary zinc intake on the abundance of histochemically reactive zinc was associated with a higher level of metallothionein. The molecular-mass distribution profile revealed that N-(6-methoxy-8-quinolyl)-para-toluenesulfonamide-reactive zinc and metallothionein-bound zinc represented two different, but interrelated, pools of zinc. Overall, these results suggested that the abundance of histochemically reactive zinc was homeostatically regulated, which was partially achieved through the regulation of metallothionein levels in rats.

Growth factor stimulated cell proliferation is accompanied by an elevated labile intracellular pool of zinc in 3T3 cells

Growth factors such as platelet-derived growth factor (PDGF), epidermal growth factor (EGF), and insulin-like growth factor-I (IGF-I) are required for quiescent 3T3 cells to proliferate, but zinc deprivation impairs IGF-I-induced DNA synthesis. We recently showed that labile intracellular pool of zinc is involved in cell proliferation. Our objective was to determine whether the labile intracellular pool of zinc plays a role in growth factor (PDGF, EGF, and IGF-I) - stimulated proliferation of 3T3 cells. Quiescent 3T3 cells were cultured in DMEM with or without growth factors. Labile intracellular pool of zinc, DNA synthesis, and cell proliferation were assessed using fluorescence microscopy, 3H-thymidine incorporation, and total cell number counts, respectively. After 24 h, growth factors stimulated DNA synthesis (24%) but not cell proliferation. After 48 h, growth factors stimulated both DNA synthesis (37%) and cell proliferation (89%). In response to growth factor stimulation, the labile intracellular pool of zinc was also elevated after 24 or 48 h of treatment. In summary, growth factor (PDGF, EGF, and IGF-I) - stimulated increase in DNA synthesis and cell proliferation were accompanied by an elevated labile intracellular pool of zinc in 3T3 cells. Since elevation of the labile intracellular pool of zinc occurred along with increased DNA synthesis, but cell proliferation remained unchanged, the elevation of the labile intracellular pool of zinc likely occurred during the S phase to provide the zinc needed to support DNA synthesis and ultimately cell proliferation.Key words: PDGF, EGF, IGF-I, labile intracellular pool of zinc, cell proliferation, DNA synthesis, 3T3 cells.

Labile intracellular zinc is associated with 3T3 cell growth

Increasing evidence shows that labile intracellular zinc is metabolically important. Depletion of labile intracellular zinc using chelators suppresses DNA synthesis. In this study, we tested the hypothesis that labile intracellular zinc could be modulated via varying zinc nutrition. This could result in an altered availability of labile intracellular zinc, which, in turn, could influence zinc-dependent cellular events involved in cell proliferation and ultimately suppress growth. Labile intracellular zinc was detected by using N-(6-methoxy-8-quinolyl)-para-toluenesulfonamide (TSQ), a membrane-permeable fluorescence probe. After 48 h culture in a zinc-depleted medium, labile intracellular zinc in 3T3 cells was diminished along with a suppressed DNA synthesis and cell proliferation. In contrast, supplementation of zinc to the zinc-depleted medium increased the labile intracellular zinc and promoted DNA synthesis and cell proliferation. Furthermore, growth factor-dependent stimulation of DNA synthesis and cell proliferation was also accompanied by increased labile intracellular zinc. Together, our data showed an association between the labile intracellular zinc, detected using TSQ, and 3T3 cell growth, suggesting that labile intracellular zinc could be an important cellular link between zinc nutrition and growth.