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The proportion of AST to ALT in hepatocytes is about 2.5:1, but because AST is removed from serum by the liver sinusoidal cells twice as quickly (serum half-life t1/2 = 18 hr) compared to ALT (t1/2 = 36 hr), so the resulting serum levels of AST and ALT are about equal in healthy individuals, resulting in a normal AST/ALT ratio around 1. See here.

B6 is more essencial for ALT synthesis than AST, that is why in chronic alcohol (low B6) we will see a reduction of ALT in proportion to AST, increasing the AST/ALT ratio>2

In general, EMR recurrence  (presence of residual polypoid tissue at the level of the scar in control colonoscopy) is described as high as 20-30%.    Currently it is recommended to treat the margins of the scar immediately after polyp resection to reduce this rate.  Treating with APC or soft snare coagulation (this latter is preferred in the ESGE guidelines) help significantly reduce the recurrence

See Bourkes group RCT

See metanalisis

This is likely a lower GI bleed, however, the fact that is so abrupt and has caused   haemorrhagic shock makes us wonder if he is not having a severe upper GI bleed – frail patient taking clopidogrel - Severe upper GI bleed sometimes can be so brisk and profuse that blood travels the intestine fast wihtout being digested, so patient passes per rectum red bright blood instead of black melaena. (Blood is laxative too) As many as 10–15% of patients suspected initially to have lower GI bleed are ultimately found to have an UGI source.

Once OGD is done and clear, the next step should be depending on the clinical and hemodinamic status. Either prepare the patient for colonoscopy/ video capsule (If clinically stable)  or repeat CT angio (If clinically worse)-->If bleeding point is located and there is no access to IR (interventional radiology) the surgeons may want to proceed with exploration and colectomy but this is the last resource as obviously this is an elderly patient with cardiovascular factors (Clopidogrel) whose surgery would be high risk of mortality and morbidity.

-MRCP does not usually require contrast.  The technique enhances any fluid  (the normal fluid which is present in the biliary and pancreatic ducts) as an intrinsic contrast medium by using heavily T2-weighted sequences. T2 potentiate water , therefore this structures will appear hyperintense against the surrounding non-fluid-containing tissues. We can see structures like stomach or duodenum being also bright due to the fluid content.

-Gadolinum is the typical MRI contrast causing brigher T1-weighted images , helping detection of focal lesions (e.g. tumor, abscess, metastasis) venography or calculating MR perfusion parameters.

-Omnipaque® is a low-osmolar iodinated contrast media is indicated for intravenous, intra-arterial or  oral use. Iodine-based contrast are often used in CT scan.

-SonoVue ® is a constrast based on sulphur hexafluoride microbubbles , which used is mainly on contrast-enhanced ultrasound imaging. Bubbles are extremely small—smaller than a red blood cell—and have a high degree of "echogenicity", reflecting ultrasound waves. Structures with higher echogenicity will be brighter on ultrasound.  The microbubbles dissolve, usually within 10 to 15 minutes, and the gas within them is cleared from the body through exhalation.

Whenever an HCC (Hepatocelullar carcinoma) is resected in an early starge, 5-year recurrence occurs in up to 60-70% of the cases,  either as a result of intrahepatic metastases (true recurrent disease) or de novo cancer in the remaining cirrhotic liver .  However, similar rates of reccurence occurs if we use ablation instead of surgical resection (  between 60% and 85% recurrence with ablation) via the same mechanisms (either incomplete tumor erradication, or new tumor formation)

5-year recurrence after liver transplant is way lower (8-20%) and of course varies depending on the tumoral burden --> potential microvascular invasion at the time of the transplant.

See BSG guidelines

Misty mesentery refers to a non-specific radiological finding characterized by increased attenuation within the mesenteric fat on computed tomography  imaging.  It mimics mistiness as localised fat stranding in the mesentery.  Many processes can lead to the appearance including infiltration by inflammatory cells, oedema, lymphatic accumulation, haemorrhage, tumour infiltration, and fibrosis.  Tipically reflects mesentery panniculitis  ( rare  benign condition characterized by chronic inflammation  of adipose tissue mainly of the small bowel mesentery) But can be the results of any inflammatory or neoplasic process. That is why it is needed to consider also vasculitis, lymphomas, inflammatory process or GI neoplasia.

Underwater EMR offers the advantage of keeping the polyp surface small in flat polyps (opposite to when we inject lifting solution where the polyp keeps spreading and this makes grabbing the polyp en bloc more difficult) this explains why is a good method to remove en bloc lesions bigger than 10mm (Ideally even bigger than 20mm, although even with U-EMR the bigger the polyp, the more difficult to obtain full resected piece en bloc. This results are published in endoscopy in this meta analysis

Although Adenocarcinoma is the most rapidly growing esophageal cancer, still the most common type of esophageal cancer worldwide is esophageal squamous cell carcinoma (SCC). The highest-risk area, called the “esophageal cancer belt,” includes portions of northern Iran, southern Russia, central Asian countries, and northern China, where SCC dominates all cases by 90%. These are very dense populated areas.

However, in Western countries like the United States, esophageal adenocarcinoma has become more common in recent decades, particularly in the lower part of the esophagus and the gastroesophageal junction (GEJ). This increase in adenocarcinoma is often linked to conditions like Barrett esophagus and gastroesophageal reflux disease (GERD).

In summary:

• Worldwide: Esophageal squamous cell carcinoma (SCC) is the most common.
• Western countries (US and Europe): Esophageal adenocarcinoma has surpassed SCC in incidence.

Delirium tremens is a form of severe withdrawal syndrome in which, long term alcohol has chronically bound to GABA receptors and modified its expression( GABA is the inhibitory neurotransmitter which normally reduces neuronal excitability) . This leads to  GABA downregulation of α1- and α3-containing GABA-A receptors (Liang and Olsen, 2014). GABAA receptor downregulation may contribute to anxiety and shakes of withdrawal once alcohol is not present in the nervous system. Also, chronic hyperestimulation of the GABA system by alcohol leads to brain mechanism of up-regulation of the postsynaptic N-methyl-D-aspartate (NMDA) type of glutamate receptor, which mediates the postsynaptic excitatory effects of glutamate to counteract this inhibitory effect of GABA, and once alcohol is suppressed this excitatory system takes over causing autonomic hyperactivity, tachicardia, cardiovascular collapse, seizures or even comma and death.

We need to differenciate between non dysplastic (the majority of Barrett's do not have any dysplasia, just metaplasia) versus dysplastic changes (proliferative changes that is characterized by a loss in the uniformity of individual cells in a tissue and loss in the architectural orientation )

The overall yearly incidence of  eosphageal adenocarcinoma in non dysplasitc  is 0.3% (. This is approximate and based on a metanalysis, although we know that factors such a age, smoking or obesity increase the overall risk of adenocarcinoma in Barrett's patients, and equally, the risk lowers when short segment (<3cm) - down to 0.19 % per year)

9.1% is the overall incidence of progression (to either HGD or adenoca) in those who already present low grade dysplasia, up to   9.1% per patient/year  with pooled annual incidence of adenocarcinoma of 0.54% per year