Case study of nutritional biochemistry (with clinical implications) - Essay Example

?Introduction One of the main identifying characteristics of heterotrophs is the ability make use of other living things, which are made up of basically the same biomolecules: carbohydrates, proteins, fats, and nucleic acid, to power their other functions, from the energy-demanding movement to the energy-reserving sleep. Because of its importance, an understanding of the processes by which organisms use up other biological products as source of energy is vital in the comprehension of the other processes that depend on it. This writing focuses on one of the conditions that adversely affect digestion, chronic pancreatitis. A case is discussed to better discuss the aspects of the disease, such as the pathophysiology and treatment. Anatomy and Physiology of Gastrointestinal Tract Upon eating, the teeth and tongue mechanically degrades the food, while the salivary amylase breaks down some of the carbohydrates into its smaller components. The bolus then passes the esophagus, which undergo peristaltic movement to allow the bolus to reach the stomach. The organ contains pepsinogen-secreting chief cells and acid-secreting parietal cells, making it the most suitable area for protein digestion. After 40 minutes to a few hours, the stomach will release chyme into the small intestine, where the ultimate degradation of food occurs. The pancreas produces carbohydrate-, protein-, and lipid-catabolizing enzymes. Similar to pepsin, these enzymes are stored in the gallbladder as deactivated proenzymes, together with emulsifying agents from the liver that allow the inherently insoluble fats and lipids to be exposed to the appropriate enzymes. The gallbladder releases this solution into the proximal part (duodenum) of the small intestine through the common bile duct. Upon release to the intestine, these proenzymes are converted to their respective active forms. Absorption of nutrients, water and minerals happens in the large intestine, which, in effect, produces the normally solidified stools that are released through the anus. Modulation of entry and exit of food from one organ to the next is possible through the sphincters that guard the openings of these organs (Campbell and Reece, 2002). Biochemical Processes in Digestion 1. The components of food Food is basically made up of three biomolecules, carbohydrates, proteins, and fats. Because the energy from carbohydrates is the most readily usable compared to those of the other two, it should be the most abundant component of every meal. Proteins, on the other hand, provide the building blocks of the endogenous proteins such as enzymes, transporters and messengers. Similarly, fats provide the building blocks for fat-based cellular components such as the cell and nuclear membranes and transporting micelles. Aside from that, fats are also significant sources of energy, as it contains the most amount of calories per weight (Campbell and Reece, 2002). 2. Enzymes in the gut The body has masterfully adapted to these differences among biomolecules. Amylase is already present in the oral cavity so that the calories in carbohydrates can be readily used for energy. As for proteins, food is kept long in the stomach so that even the most complicated structures are degraded by pepsin. Because the gut wall is made up of proteins as well, they should be protected from the activity of the proteinase. That is why the enzyme is initially available as a proenzyme, which is only activated by exposure to low pH levels. Fats, on the other hand, are inherently insoluble to the aqueous solution it is exposed to in the gut. For this reason, the emulsifying bile is produced by the liver (Koeppen and Stanton, 2010). As can be seen, the gut, pancreas and liver play equally important roles in the proper degradation of food. Digestion thus has multiple regulatory points by which the process can be modulated, dependent on the food taken in. As well, problems arising from one organ can significantly affect the whole digestion process. 3. Absorption and excretion After all the biomolecules have been enzymatically degraded, they are absorbed in the large intestine or colon. Water is absorbed in this organ as well. This allows for the production of a dehydrated stool and prevention of severe water loss (Koeppen and Stanton, 2010). Summary of Case This is a case of a 55 year old male with a two-year intermittent history of abdominal pain radiating to the back. The patient also complained of foul-smelling stools. During physical examination, the patient was tired and thin. The blood pressure and pulses were normal, and there was a slight degree of ankle edema. Upon laboratory examination, the patient had normal abdominal X-ray. Glycosuria was also noted, with fasting glucose levels at 12 and 15 mmol/L (216 to 270 mg/dl) on two separate occasions. This is hyperglycemic, as normal levels are < 100 mg/dl, and levels above 126 mg/dl are diagnostic of diabetes (American Diabetes Association, 2011). The patient also presented with Helicobacter pylori infection, ulcerations at the peptic orifice of the stomach and esophagus, as well as enlarged pancreas through ultrasound and CT scan, which also showed calcifications. MRI showed dilated, irregular pancreatic duct. Upon blood chemistry measurements, the patient had low albumin levels (30g/l), while the activities of alkaline phosphatase (ALP) (65 U/I), gamma glutamyl transferase (GGT) (65 U/I), and amylase (370 U/I) were normal. Alanine aminotransferase (ALT) and Bilirubin levels were normal as well. The patient was a heavy alcoholic drinker. Differential diagnoses were chronic pancreatitis and pancreatic carcinoma. Since no tumor mass were evident during the imaging studies, definitive diagnosis is chronic pancreatitis, possibly due to the heavy alcohol intake. Upon dietary and alcohol intake restriction, steatorrhea regressed, patient gained weight, and blood glucose was controlled. Pathophysiology of Chronic Pancreatitis Chronic pancreatitis is an inflammatory condition involving the pancreas. The natural history starts from the damage of exocrine parenchyma, then continues on to fibrosis, and, finally, to the destruction of the endocrine parenchyma (Kumar et al., 2011). It occurs to people ages 30-40, and more often among men than women. This disease does not heal or improve over time, and thus leads to permanent damage to the organ and system. As a result, it is unable to produce the enzymes necessary to derive nutrients from food, especially fats, as well as its hormonal secretions, including insulin (Longstreth, 2010). It usually results from alcohol abuse and/or repeat episodes of acute pancreatitis. Chronic alcohol intake increases the protein concentration of pancreatic juice, making it prone to hardening that may plug the pancreatic duct. In time, this plug calcifies. In addition, alcohol may destroy the acinar cells of the pancreas (Kumar et al., 2011). Other conditions that lead to chronic pancreatitis include autoimmune diseases (leading to inflammation), blockage of the pancreatic or common bile duct, cystic fibrosis, hypertriglyceridemia, hyperparathyroidism (the increase in serum calcium may lead to calcification of the enzyme solution), and use of drugs such as estrogens, corticosteroids, thiazide diuretics, and azathioprine (Longstreth, 2010). Activation of pancreatic enzymes while inside the organ, causes irritations and damage to the pancreatic cells (Mayo Clinic, 2011). Because the inflamed pancreas produces enzymes as a response to signals of food intake, abdominal pain gets worse immediately after eating or drinking, or whenever the pancreas has to work. The distention of the already enlarging pancreas pushes on the abdominal walls which are full of nerve endings. Because of great pain associated with ingestion, there is chronic weight loss because some patients choose not to eat. Still, even when eating habits are normal, malabsorption, subsequent thinning and weakening still ensue. Fatty and oily stools are also experienced because of the inability to degrade fats. This reacts with the bacteria present in the colon, producing a much more malodorous gas emission. Abdominal pain related to chronic pancreatitis is felt at the upper abdomen, where the pancreas is anatomically located, and radiates in the back (Longstreth, 2010). Treatment Since the pain may be too severe for the patient, analgesics can be provided. To prevent the symptoms from occurring, food or fluid intake by mouth may be limited to decrease the activity of the pancreas. As well, removing the contents of the stomach by nasogastric suctioning may be done (Longstreth, 2010). Aside from such interventions, diet should also be modified. Drinking plenty of fluids is advised. As well, because fat digestion is limited among chronic pancreatitis patients, fatty foods are restricted. Eating frequently small amounts of food decreases the gastrointestinal movement associated with eating, and subsequently reduces the abdominal pain. Extra supplements should also be provided to make up for the malabsorption associated with the disease. Examples are calcium and vitamins. At times, insulin should also be given as the hormonal function of the pancreas is as compromised as its function in digestion (Longstreth, 2010). Complications If not treated accordingly, possible complications are ascites, obstruction of small intestine and/or bile ducts, blood clot in the vein of the spleen, and pancreatic pseudocysts prone to infection (Longstreth, 2010). As well, it can lead to breathing problems, blood clot, kidney failure, and pancreatic cancer (Mayo Clinic, 2011). Discussion Analysis of Patient Work-up The patient is a classic case of chronic pancreatitis, as observed by abdominal pain radiating in the back, foul-smelling stools, and thinning and weakening experienced by the patient. Although it is a standard imaging procedure, x-ray for abdominal problems is, in this writer’s opinion, unnecessary, as its important findings (calcification) may be identified through CT scan. Meanwhile, the glycosuria, hyperglycemia, and edema observed is a manifestation of the deteriorating condition of pancreas, which cannot produce enough insulin. Without this hormone, sugar cannot enter the cells, and it remains in the blood serum. Such condition is very prone to development of diabetes and/or renal problems, which may be causing the edema. The infection may have been caused by the excessive growth of normal bacterial flora of the gut as induced by the excessive intersitital fluid due to ascites and/or edema present in the patient. Helicobacter pylori, aptly named because of its preference for the stomach walls, occurs in about half of the world’s population. Because it usually does not present with symptoms, infected, asymptomatic individuals do not seek treatment, and/or do not even know they have infection. As such, this is easily passed on from an infected person to a new host through saliva, vomit, fecal matter, food and water. Symptoms, if present, include peptic ulcers, which are observed in the patient. This infection might have also contributed to the pain and weight loss experienced by the patient, since the inflammatory reaction induced by the infection increases the size of the gut walls that press on one another and to the highly sensitive abdominal wall. However, not all peptic ulcers are caused by H. pylori, that is why microscopic identification is necessary to identify the infecting agent. Subsequently, identifying the culprit microorganism is needed to correctly choose which antibiotics should be given. In addition, antacids can be given to increase the pH in the stomach and, in effect, to facilitate the healing of peptic ulcers (Mayo Clinic, 2011). Meanwhile, the enlargement of the pancreas is due to the inflammation and or edema of the organ. The dilation of the pancreatic duct is a sign of blockage of the passageway, possibly because the pancreatic products cannot exit the organ. However, the normal levels of blood proteins (albumin) and liver enzymes (ALP, ALT, and Bilirubin) may mean that the liver is still unaffected by the stock-up of bile that cannot get out of the liver. As for the treatment, this writer agrees with the approach of the physician. The primary option is change of dietary intake. Medical intervention is only necessary when such procedure does not produce significant effects to benefit the patient. However, for individuals with chronic pancreatitis and a dilated pancreatic duct, as is the case in this patient, drainage of the duct is necessary (Cahen et al. 2007). The infection and secondary peptic ulcerations should also be resolved as well. Chronic Pancreatitis at Present Currently, there are two options for pancreatic duct drainage, surgical, through longitudinal pancreaticojejunostomy, and endoscopic, which involves sphincterotomy, dilation of duct, and removal of hardened substances. Briefly, the surgery entails incision over the full length of the duct plus 2 cm from the ampulla, and, if necessary, wedge resection of pancreatic tissue. After removal of concretized materials, the opened areas are anastomosed. For endoscopic approach, on the other hand, a balloon or Soehendra catheter, and a 10-French Amsterdam biliary stent without side holes are inserted into the pancreatic duct to keep it open. Within six weeks after the procedure, a 7- or 8.5- French stent will be used to replace the bigger stent (Cahen et al., 2007). According to Cahen and his colleagues (2007), pancreaticojejunostomy provided better result than the endoscopic approach. 75% of the surgically-treated patients (n=20) reported complete or partial relief, while only 32% of the endoscopic patients (n=19) had similar results. The latter provided a more rapid, effective and sustained pain relief. In addition, opening the pancreatic capsule during the surgical procedure might secondarily relieve the interstitial pressure exerted upon the pancreas. In addition, even if rates of complications, length of hospital stay, and changes in pancreatic function were similar in the two treatment groups, patients receiving endoscopic treatment had relatively less relief, because they required more procedures than did patients in the surgery group. This finding is substantial as it may imply that the surgery can make the quality of life well enough to enable the patient to return to work. One of the probable reasons given is that the former ensures smooth flow over the full length of the pancreas. Recommendations To add onto the management of the condition of this particular patient, antibiotics and antacids should be given. As well, the option of surgery, in particular pancreaticojejunostomy, should be opened up to the patient as it can address the stenosis of pancreatic duct and pancreatitis, as well as alleviate the debilitating symptom of abdominal pain. . Conclusion Chronic pancreatitis is a serious condition, especially because abdominal pain is felt every time an affected individual has taken in food orally. Thus, its serious complications may include starvation, malnutrition and peptic ulceration. Although there is no treatment approach that can resolve the disease, dietary modifications are enough to at least alleviate its symptoms. Very important is fat restriction, eating frequently but smaller portions, and avoidance of alcohol. Pancreatic duct obstruction and inflammation of pancreas may also be resolved using a surgical approach, specifically pancreaticojejunostomy. In the particular case discussed above, the 55 year old male patient complaining abdominal and back pain suffered from multiple peptic ulceration and Helicobacter pylori infection secondary to chronic pancreatitis. This condition might have resulted from his long-standing alcohol abuse that formed protein plugs blocking the pancreatic duct. The physician was able to perform the examinations necessary to clinch the diagnosis, such as CT scan and ultrasound, although the abdominal x-ray could have been done without. Furthermore, complications were properly looked into as well. The involvement of liver was determined by measurement of Bilirubin, ALP and ALT. Peptic ulcerations were verified through endoscopy, and infection was found out by biopsy and microscopy. However, this writer feels that the management could have done more to relieve the symptoms of the patient. Appropriate antibiotics could have been given to cure H. pylori infection and to prevent more peptic ulcerations. Medications could have included antacids to decrease the acidity of the stomach, and allow existing ulcers to heal. Surgery could have also been done. In particular, pancreaticojejunostomy could have been performed to address the dilating pancreatic duct and the inflamed pancreas as well. References American Diabetes Association. 2011. Standards of medical care in diabetes -- 2011. Diabetes Care, 32, pp. S11-S61. Cahen, D.L., Gouma, D. J., Nio, Y., Rauws, E. A. J., Boermeester, M. A., Busch, O. R., Stoker, J., Lameris, J. S., Dijkgraaf, M. G. W., Huibregste, K., and Bruno, M. J. 2007. Endoscopic versus Surgical Drainage of Pancreatic Duct in Chronic Pancreatitis. New England journal of Medicine, 356(7), pp. 676-684. Campbell, N. A. and Reece, J. B. 2002. Biology. 6th ed. San Francisco: Benjamin Cummings. . Koeppen, B. M. and Stanton, B. A. 2010. Berne and Levy Phisiology. 6th ed. Missouri: Mosby. Kumar, V., Abbas, A. K., Fausto, N., and Aster, J. 2011. Robbins and Cotran Pathologic Basis of Disease. 8th ed. Philadelphia: Saunders. p. 896 Longstreth, G. F. 2010. Chronic Pancreatitis. Available at: http://www.nlm.nih.gov/medlineplus/ency/article/000221.htm. November 22, 2011. Mayo Clinic. 2011. H. pylori infection. Available at: http://www.mayoclinic.com/health/h-pylori/DS00958. November 24, 2011. Mayo Clinic. 2011. Pancreatitis. Available at: http://www.mayoclinic.com/health/pancreatitis/DS00371. November 24, 2011. Read More