GIT, Tuberculosis , Cancer

TuberculosisGastrointestinal disordersDisease of the liverCancer

Tuberculosis is an infectious disease caused by the organism Mycobacterium tuberculosis. Unlike most other bacteria, M. Tuberculosis is surrounded by an outer capsule that makes the organism very resistant to destruction.

Mycobacterium tuberculosis is primarily transmitted via the airborne route.Once in the lung tissues, the organism causes an inflammatory reaction as it is attacked first by poly-morphonuclear leukocytes and later by macrophages.

Testing for TuberculosisMantoux test — Intradermal test for reaction against the

tuberculin purified protein derivative standard (PPDS)Acid-fast staining of sputum cultures to visualize Chest radiograph to identify Ghon’s complex

Manifestations of primary tuberculosis:

• Productive, prolonged cough

• Chest pain, hemoptysis

• Chill, fever, night sweats

• Anorexia, weight loss

General Symptoms of G.I. Disease

Anorexia — loss of appetiteNauseaVomitingDiarrhea, constipationBleeding — obvious or “occult” (i.e., detected by

laboratory test)

Gastroesophageal reflux diseaseGastroesophageal reflux is a condition caused by

the backflow of stomach contents into the esophagus.

It results from weakness or incompetence of the lower esophageal sphincter that normally blocks reflux of stomach contents into the esophagus.

Because of their high acid content (low pH), reflux of stomach contents will cause irritation and inflammation of the esophagus (esophagitis) that can lead to ulceration of the esophagus.

A hiatal hernia may also cause gastroesophageal reflux. A hiatal hernia is a protrusion of the top of the stomach through the opening of the diaphragm.

Manifestations

Burning pain in the epigastric region (“heartburn”) that may be worsened by alcohol consumption, caffeine, smoking, exercise and obesity.

Reflux may also be worsened by lying down.

Esophagitis, possible ulceration of esophagus.

Dysphagia, poor nutrition.

Possible increased risk of esophageal cancer with chronic esophagitis.

Peptic ulcersThe term peptic ulcer refers to erosion of the

mucosa lining any portion of the G.I. tract.

If the ulcer occurs in the stomach lining, it is specifically referred to as a gastric ulcer.

In the United States most ulcers occur in the duodenum and in elderly patients.

The causes of peptic ulcer disease include the following: Infection with the bacteria Helicobacter pylori occurs in 80 to 95% of

patients with peptic ulcer disease. H. pylori infection impairs the protective mechanisms of the G.I. tract against low pH and digestive enzymes and leads to ulceration of the mucosa.

Stress — Emotional, trauma, surgical.

Injury or death of mucus-producing cells.

Excess acid production in the stomach. The hormone gastrin stimulates the production of acid in the stomach; therefore, any factors that increase gastrin production will in turn increase the production of stomach acid

Chronic use of aspirins and NSAIDs.

Manifestations of peptic ulcer disease

Episodes of remission and exacerbation

Pain that for duodenal ulcers is often relieved by eating or antacids

G.I. bleeding and possible hemorrhage (20 to 25% of patients)

Perforation of ulcers with significant mortality

Obstruction of G.I. tract

Disorders of the intestines

Irritable bowel syndromeMay be one of the most common G.I. disorders.

Patients present with symptoms of G.I. pain, gas, bloating and altered bowel function (diarrhea or constipation). Most symptoms are localized to the lower intestine and colon.

No underlying pathophysiologic processes have yet to be identified in these patients. “Hyperreactivity” and excessive motility of the bowels may be contributing factors.

Emotional factors and diet may exacerbate the symptoms.

Treatment may include psychological counseling, dietary changes such as increased fiber consumption. Antidiarrhea, anticholinergic and antispasmodic agents might also be of value.

Inflammatory bowel disease

The term inflammatory bowel disease includes the conditions Crohn’s disease and ulcerative colitis . Both of these diseases are characterized by chronic inflammation of various regions of the G.I. tract

Crohn’s disease

Although the exact etiology of Crohn’s disease in unknown, there appears to be a significant autoimmune component. Much recent interest has focused on the possible role of pro-inflammatory cytokines in the pathogenesis of this disorder.

The disease may affect any region of the G.I. tract but is most commonly seen in the distal ileum and colon.

Distribution of Crohn’s disease shows a distinct predisposition to certain populations including Jews and individuals from the United States, Western Europe and Scandinavia.

The disease often presents in the late teens to early 20s and is present for the life of the patient with intermittent periods of remission and exacerbation.

The inflammation of Crohn’s disease is particularly evident in the submucosal layer of the intestine. The pattern of inflammation seen is a granulomatous inflammation with distinct “cobblestone” appearance to the mucosa.

The inflammatory lesions are not constant along the length of the intestine but rather present with a “skip” pattern that intersperses areas of inflammation with normal looking, non-inflamed tissue.

Manifestations of Crohn’s disease

Diarrhea (blood is usually not evident in the stool but may be occult, i.e., detected by clinical assay)

Intestinal pain similar to indigestion

Fever

Weight loss from intestinal malabsorption

Nausea, anorexia, vomiting

Complications: intestinal obstruction, formation of fistulas (abnormal connections between the colon and other abdominal organs)

Toxic megacolon

Ulcerative colitis

Inflammatory disease of the rectum and colon.The disease primarily affects the submucosa layer of the

intestines.Unlike Crohn’s disease the pattern of inflammation is

continuous throughout the affected area.Like Crohn’s disease, ulcerative colitis also presents with

periods of remission and exacerbation.

Although the exact etiology of ulcerative colitis is unknown, genetic and immunological factors are likely contributors to the disease.

Individuals between the ages of 20 and 40 are most susceptible, particularly those with a family history of the disorder or who are of Jewish descent.

Manifestations of ulcerative colitis

Chronic, bloody diarrheaFever, painWeight lossPossible anemia from blood lossPossible complications: toxic megacolon , perforation of

the intestine, significant blood loss; an increased incidence of colon cancer has also been documented in patients with ulcerative colitis

Viral hepatitis

The term hepatitis refers to inflammation and possible injury of the liver.

Hepatitis may be caused by a number of injurious agents such as viruses, alcohol, toxins and drugs.

When the liver is inflamed and injured as a result of viral infection it is termed a viral hepatitis .

In the United States, there are three main hepatitis viruses, designated hepatitis A, B and C. Two other variants, hepatitis D and E are also present in certain populations.

All of the hepatitis viruses target the hepatocytes of the liver as their site of infection and replication.

Characteristics of Viral Hepatitis

Hepatitis virus A

Hepatitis virus B

Hepatitis virus C

Hepatitis virus D

Hepatitis virus E

Incubation (days)

15–50 30–180 15–160 30–180 10–60

Transmission F/O

fecal/oral

BBFblood and body fluids

BBF BBF F/O

Onset Abrupt Insidious Insidious Insidious Abrupt

Chronic

hepatitis

Rare Possible Possible Possible Unlikely

Manifestations of viral hepatitis

Range from asymptomatic to severe

Fatigue, malaise, anorexia, nausea

Jaundice

Liver inflammation and abdominal pain

Abnormal liver function and enzyme levels

Possible complications of hepatitis

Chronic active or persistent hepatitis can lead to progressive liver injury, liver failure and death. The chronic form of hepatitis is most common with hepatitis B, C, D, but rare with hepatitis A and E.

Chronic active hepatitis is also associated with an increased incidence of hepatocellular carcinoma.

cancer

Cancer is a disease that results from abnormal growth and differentiation of

tissues.

Tumor or neoplasm - A mass of tissue in which the growth rate is excessive and uncoordinated when compared with normal tissues

Benign neoplasm

Tumor cells that tend to be clustered in a single mass

and are not malignant

Malignant neoplasm— Tumors that have the ability to or break loose and spread to other areas of the body.

Metastasis — The ability of tumor cells to spread to other parts of the body and establish secondary tumors.

A genetic predisposition has been observed for a number of cancers including colon cancer, breast cancer, retinoblastoma and certain forms of leukemia and lymphoma.

Theories of oncogenesis

Abnormalities of tumor suppressor/inducer genes

Mutation of DNA

Manifestations of cancer

Many cancers may be asymptomatic in the early stages. As the tumors continue to grow, they affect local tissues as well as the overall body.

1- Local effects of cancer

• Compression of blood vessels

• Ischemia

• Pain

• Bleeding

• Infection

• Altered tissue function

2- Systemic effects of cancer

• Fatigue

•Cachexia ( A complex syndrome characterized by anorexia, weight loss and lean body (muscle) wasting)

• Bleeding and hemorrhage

• Anemia

• Altered organ function

• Abnormal hormone production

Cancer detection

Tumor cell markersVisualizationBiopsy

Staging of Tumors

T — Primary tumor (T1–T4 )

N — Involvement of lymph nodes (N1–N3 )

M — Distant metastasis (M1–M4 )

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