Reversal by ribo- and deoxyribonucleosides of dehydroepiandrosterone-induced inhibition of enzyme altered foci in the liver of rats subjected to the initiation-selection process of experimental carcinogenesis

The effect of dehydroepiandrosterone (DHEA) on the activityof NADPH-producing enzymes and the development of enzyme-alteredfoci has been investigated in the liver of female Wistar ratssubjected to an initiating treatment (a necrogenic dose of diethylnitrosaimine)followed, 15 days later, by a selection treatment [a 15-dayfeeding of a diet containing 0.03% 2-acetylamlnofluorene (2-AAF),with a partial hepatectomy at the midpoint of this feeding].At the end of the selection treatment all rat groups received,for 15 days, a basal diet containing, when indicated, 0.05%phenobarbital (PB) and/or 0.6% DHEA. The effect of DHEA on theactivity of NADPH producing enzymes was also studied in normalrats fed, for 15 days, a diet containing 0.6% DHEA and in theirpair-fed controls. DHEA caused a 43–58% inhibition ofglucose-6-phosphate dehydrogenase (G6PD) and, respectively,338–420% and 21–24% increases in malic enzyme (ME)and isocitric dehydrogenase activities in all rat groups. Thiswas coupled with a great fall in the production of ribulose-5-phosphate,while no change in NADP⁺/NADPH ratio occurred. Hepatocytes,isolated from DHEA-treated rats, exhibited a very low activityof hexose monophosphate shunt (HMS), which was not stimulatedby methylene blue, an exogenous oxidizing agent that markedlystimulated HMS activity in control hepatocytes. DHEA causeda great fall in the percentage of liver occupied by -glutamyltranspeptidase(GGT)-positive foci, in the rats subjected to the initiation- selection treatments. PB enhanced the development of thesefoci, an effect which was completely overcome by DHEA. In addition,focal cells no longer expressed a G6PD activity higher thanthat of surrounding liver in DHEA-treated rats, but exhibiteda high histochemical reaction for ME. DHEA also caused a greatfall in labelling index of GGT-positive foci. Starting at theend of 2-AAF feeding, a mixture of ribonucleosides (RNs) ofadenine, cytosine, guanine and uracil and of deoxyribonucleosides(DRNs) of adenine, cytosine, guanine and thymine were injectedi.p. every 8 h for 12 days to the rats subjected to the initiation- selection treatments plus PB. Rats were killed 3 days afterthe end of RN and DRN treatments. These treatments completelyovercome the DHEA effect on the development of GGT-positivefoci and DNA synthesis by the focal cells, without affectingG6PD activity of both whole liver and putative preneoplasticfoci. Experiments with labeled nucleosides revealed that RNsand DRNs produced derivatives that were incorporated into liverDNA. These data indicate that liver of DHEA-treated rats produceenough NADPH for reduction of RNs to DRNs and growth. The antipromotingeffect of DHEA could depend on a relative deficiency of nudeosidesfor DNA synthesis, caused by a great fall in pentose phosphateproduction.     

Common Exposure to STL Polyomavirus During Childhood

STL polyomavirus (STLPyV) was recently identified in human specimens. To determine seropositivity for STLPyV, we developed an ELISA and screened patient samples from 2 US cities (Denver, Colorado [500]; St. Louis, Missouri [419]). Overall seropositivity was 68%–70%. The age-stratified data suggest that STLPyV infection is widespread and commonly acquired during childhood.     

Effects of morphine on human pancreatic secretion: studies on pure pancreatic juice.

Data concerning the effects of morphine on human pancreatic secretion are fragmentary and inconclusive. In the present study, we evaluated the effects of morphine on pure pancreatic secretion in nine subjects with external transduodenal drainage of the main pancreatic duct performed after biliary tract surgery. Intravenous infusion of a small dose of morphine, 40 microgram/kg/h, during pancreatic stimulation with secretin and cholecystokinin, caused a significant increase in volume, bicarbonate, and calcium secretion, and a significant decrease in protein secretion. The stimulatory effect on water and electrolyte secretion was rapid and much more pronounced, reaching about 45-50% of the control levels, whereas the inhibition of protein output was slightly delayed and of lesser magnitude, reaching about 20-25% of the control values. Both effects were long-lasting. The addition of naloxone, potent opiate antagonist, prevented in part the effects of morphine on pancreatic secretion, suggesting that specific opiate receptors might be involved in these effects.     

Elevation of Carbohydrate Antigen 19.9 in Benign Hepatobiliary Conditions and Its Correlation with Serum Bilirubin Concentration

Background Carbohydrate antigen 19.9 (CA19.9), a tumor marker for malignancies of the hepatobiliary tract and pancreas, has frequently been shown to be deranged in a number of non-malignant conditions that are associated with jaundice. This study aims to demonstrate the correlation between CA19.9 and serum bilirubin concentration in patients with benign conditions and to determine the frequency of a false-positive increase in CA19.9 in patients being investigated for potential HPB malignancies. Methods This is a retrospective review of 83 consecutive patients presenting with an abnormal CA19.9 and radiological or clinical features suggestive of HPB malignancy subsequently shown to have benign disease. All patients were thoroughly investigated and followed up until the diagnosis of malignancy could be safely excluded. Results Serum bilirubin, sodium, lymphocyte count, neutrophil:lymphocyte ratio (NLR), β-human chorionic gonadotrophin (HCG), and age were found to correlate with CA19.9 by Pearson’s correlation (P = 0.001, P = 0.006, P = 0.006, P < 0.001, P = 0.012, and P = 0.049, respectively). In multivariate regression analysis, bilirubin was identified as an independent variable that may predict CA19.9 level (P = 0.028). Conclusion CA19.9 level is significantly influenced by serum bilirubin and elevated levels have been observed in patients with non-malignant HPB conditions. Adjusting CA19.9 according to bilirubin levels is likely to improve the specificity of this antigen in the differential diagnosis of benign and malignant HPB diseases and its reliability in the monitoring of disease response to chemotherapy.     

Lymph node pick up by separate stations: Option or necessity

AIM: To evaluate whether lymph node pick up by separate stations could be an indicator of patients submitted to appropriate surgical treatment. METHODS: One thousand two hundred and three consecutive gastric cancer patients submitted to radical resection in 7 general hospitals and for whom no information was available on the extension of lymphatic dissection were included in this retrospective study. RESULTS: Patients were divided into 2 groups: group A, where the stomach specimen was directly formalinfixed and sent to the pathologist, and group B, where lymph nodes were picked up after surgery and fixed for separate stations. Sixty-two point three percent of group A patients showed 16 retrieved lymph nodes compared to 19.4% of group B(P 0.0001). Group B(separate stations) patients had significantly higher survival rates than those in group A [46.1 mo(95%CI: 36.5-56.0) vs 27.7 mo(95%CI: 21.3-31.9); P = 0.0001], independently of T or N stage. In multivariate analysis, group A also showed a higher risk of death than group B(HR = 1.24; 95%CI: 1.05-1.46).CONCLUSION: Separate lymphatic station dissection increases the number of retrieved nodes, leads to better tumor staging, and permits verification of the surgical dissection. The number of dissected stations could potentially be used as an index to evaluate the quality of treatment received.     

Role of preoperative carbohydrate loading: a systematic review

INTRODUCTION

Surgical stress in the presence of fasting worsens the catabolic state, causes insulin resistance and may delay recovery. Carbohydrate rich drinks given preoperatively may ameliorate these deleterious effects. A systematic review was undertaken to analyse the effect of preoperative carbohydrate loading on insulin resistance, gastric emptying, gastric acidity, patient wellbeing, immunity and nutrition following surgery.

METHODS

All studies identified through PubMed until September 2011 were included. References were cross-checked to ensure capture of cited pertinent articles.

RESULTS

Overall, 17 randomised controlled trials with a total of 1,445 patients who met the inclusion criteria were identified. Preoperative carbohydrate drinks significantly improved insulin resistance and indices of patient comfort following surgery, especially hunger, thirst, malaise, anxiety and nausea. No definite conclusions could be made regarding preservation of muscle mass. Following ingestion of carbohydrate drinks, no adverse events such as apparent or proven aspiration during or after surgery were reported.

CONCLUSIONS

Administration of oral carbohydrate drinks before surgery is probably safe and may have a positive influence on a wide range of perioperative markers of clinical outcome. Further studies are required to determine its cost effectiveness.     

Serology and ultrasound for diagnosis of choledocholithiasis

Introduction

Magnetic resonance cholangiopancreatography (MRCP) is not a routine investigation to exclude choledocholithiasis unless there is clinical or biochemical suspicion of common bile duct (CBD) stones. This study attempted to determine which radiological or serological parameters best predicted CBD stones.

Methods

All patients undergoing MRCP from 2005 to 2011 were selected. Patients with pancreatitis were excluded. Liver function tests (LFTs) at admission and prior to MRCP were recorded, as was abdominal ultrasonography and MRCP results. Parameters measured routinely on LFTs included alkaline phosphatase (ALP), alanine transaminase (ALT) and bilirubin. Receiver operating characteristic curve area analysis (area under the curve [AUC]) and chi-squared analysis were undertaken.

Results

Overall, 195 patients were identified, 71 of whom had CBD stones on MRCP. Raised ALP levels on admission demonstrated a correlation with CBD stones (AUC: 0.619, odds ratio [OR]: 3.16, p=0.06). At ultrasonography, a dilated CBD (OR: 3.76, p<0.001) and intrahepatic duct dilation (OR: 5.56, p<0.001) were highly significant predictors. However, only 37% of patients had a dilated CBD on ultrasonography. Ongoing elevation of LFT parameters, particularly ALP (AUC: 0.707, OR: 4.64, p<0.001) and ALT (AUC: 0.646, OR: 5.40, p<0.001), displayed a significant correlation with CBD stones.

Conclusions

Ongoing (even if minor) elevations of liver function test parameters should prompt the need to exclude CBD stones even in the presence of a normal CBD diameter on ultrasonography.     

Pilot study of oral silibinin, a putative chemopreventive agent, in colorectal cancer patients: silibinin levels in plasma, colorectum, and liver and their pharmacodynamic consequences.

Silibinin, a flavonolignan from milk thistle, has intestinal cancer chemopreventive efficacy in rodents. It is a strong antioxidant and modulates the insulin-like growth factor (IGF) system by increasing circulating levels of IGF-binding protein 3 (IGFBP-3) and decreasing levels of IGF-I. Here, the hypothesis was tested that administration of oral silibinin generates agent levels in human blood and colorectal and hepatic tissues consistent with pharmacologic activity. Patients with confirmed colorectal adenocarcinoma received silibinin formulated with phosphatidylcholine (silipide) at dosages of 360, 720, or 1,440 mg silibinin daily for 7 days. Blood and biopsy samples of normal and malignant colorectum or liver were obtained before dosing, and blood and colorectal or hepatic tissues were collected at resection surgery after the final silipide dose. Levels of silibinin were quantified by high-pressure liquid chromatography-UV, and plasma metabolites were identified by liquid chromatography-mass spectrometry. Blood levels of IGFBP-3, IGF-I, and the oxidative DNA damage pyrimidopurinone adduct of deoxyguanosine (M1dG) were determined. Repeated administration of silipide was safe and achieved levels of silibinin of 0.3 to 4 micromol/L in the plasma, 0.3 to 2.5 nmol/g tissue in the liver, and 20 to 141 nmol/g tissue in colorectal tissue. Silibinin monoglucuronide, silibinin diglucuronide, silibinin monosulfate, and silibinin glucuronide sulfate were identified in the plasma. Intervention with silipide did not affect circulating levels of IGFBP-3, IGF-I, or M1dG. The high silibinin levels achieved in the human colorectal mucosa after consumption of safe silibinin doses support its further exploration as a potential human colorectal cancer chemopreventive agent.