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The Digestive (Gastrointestinal) System and Its Disorders
Published in Walter F. Stanaszek, Mary J. Stanaszek, Robert J. Holt, Steven Strauss, Understanding Medical Terms, 2020
Walter F. Stanaszek, Mary J. Stanaszek, Robert J. Holt, Steven Strauss
Agents capable of causing acute hepatitis include several viruses, alcohol, toxins, and drugs. Viral hepatitis is primarily caused by hepatitis A virus (HAV), hepatitis B virus (HBV), or the non-A, non-B agents. Hepatitis B is a common cause of chronic hepatitis. Acute and chronic hepatitis are manifested clinically by fatigue, anorexia, weight loss, malaise, fever, and right upper quadrant abdominal pain. The additional symptoms of spider telangiectases (tela-= web-like; angi-= artery; -ectasia = dilation of a vessel), palmar erythema, gynecomastia, testicular atrophy, and diminished libido suggest cirrhosis. Severe viral hepatitis and cirrhosis are the most commonly observed causes of jaundice.
Breast disorders in children and adolescents
Published in Joseph S. Sanfilippo, Eduardo Lara-Torre, Veronica Gomez-Lobo, Sanfilippo's Textbook of Pediatric and Adolescent GynecologySecond Edition, 2019
Nirupama K. De Silva, Monica Henning
Mammary duct ectasia is a condition of benign dilatations of the subareolar ducts resulting in inflammation and fibrosis. This is thought to be an anomaly of duct development that results in “pleats” of obstructing epithelium in the lumen of the duct.6 This obstruction can lead to bacterial overgrowth and abscess, most commonly with S. aureus.11 Other proposed etiologies include chronic inflammation of the periductal stroma with duct obliteration, trauma, and autoimmune reaction.33 Patients with mammary duct ectasia typically present with a bloody discharge and may also have a retroareolar mass or breast enlargement. Ductal ectasia often resolves spontaneously.6,11 There may be recurrences that usually respond to conservative therapy. Surgical excision may be indicated for persistent or recurrent symptoms or for an associated persistent cyst.11 In girls, the excision should be limited to any identified cyst, with great care taken to not injure the underlying breast bud.
Gastrointestinal bleeding
Published in Michael JG Farthing, Anne B Ballinger, Drug Therapy for Gastrointestinal and Liver Diseases, 2019
Matthew R Banks, Peter D Fairclough
Once a diagnosis of ectasia has been made, treatments can be instigated acutely during bleeding or to prevent rebleeding. Since little evidence is available for the treatment of specific causes of vascular ectasias, and the pathogenesis remains obscure, drug trials have generally aimed at multiple pathophysiological targets, and thus evidence quoted in this section encompasses ectasias as a heterogeneous group.
Corneal Biomechanics Losses Caused by Refractive Surgery
Published in Current Eye Research, 2023
FangJun Bao, Bernardo T. Lopes, XiaoBo Zheng, YuXin Ji, JunJie Wang, Ahmed Elsheikh
Despite a large body of research on the topic, the pathogenesis of iatrogenic ectasia is not yet fully elucidated. Ectatic cornea could have developed keratoconus or had biomechanical weakness preoperatively,3 with the loss of tissue during CRS further weakening the cornea, destabilizing its architecture, and precipitating ectasia.4 Several risk factors including abnormal topographic pattern, low residual stromal bed thickness, thin preoperative corneal thickness, young age, high refraction error correction and percent tissue altered have been identified for developing iatrogenic ectasia.5–7 This research and the current careful screening of potential candidates for refractive surgery, have led to reduced numbers of iatrogenic keratectasia cases.3 This review looks closely at the biomechanics of the commonly used forms of CRS, the effects on corneal behavior and mechanical integrity and the current methods to estimate corneal biomechanics in vivo with a view to risk-assess individual CRS patients.
Corneal Collagen Cross-Linking Complications
Published in Seminars in Ophthalmology, 2018
Charisma B. Evangelista, Kathryn M. Hatch
Corneal collagen cross-linking (CXL) is a minimally invasive procedure for KCN and post-LASIK ectasia and is the first and only treatment currently known to stop progression of ectatic conditions of the cornea.5 The procedure has changed the way patients with ectasia are clinically evaluated and managed. CXL involves the application of commercially manufactured ophthalmic riboflavin (vitamin B2) solution and ultraviolet radiation (UV-A) to the corneal stroma. The combination of riboflavin and UV-A induces the production of free oxygen radicals, which allows for the formation of new covalent bonds in stromal collagen.6 Clinical results of CXL include arresting progression of the condition, vision preservation, possible improvement of topographic shape, and preventing the future need for keratoplasty.
Comparison of Different Methods of Corneal Collagen Crosslinking: A Systematic Review
Published in Seminars in Ophthalmology, 2021
Sidi Mohamed Hamida Abdelkader, Joaquín Fernández, Manuel Rodríguez-Vallejo, Alicia Sánchez-García, David P Piñero
Keratoconus is the most frequent ectasia—defined as a progressive non-inflammatory corneal degeneration—that causes corneal thinning, myopia, and irregular astigmatism, as well as corneal scarring in the apical part in some cases, consequently leading to a loss of visual quality.1–5 A pathophysiologic explanation for primary ectasia is currently lacking, and this suggests the contribution of environmental, biomechanical, genetic, and biochemical disorders; moreover, secondary ectasia may be caused by a purely mechanical process in a predisposed cornea and may be unilateral.6 Great advances have been made over the last two decades in the diagnosis and management of this pathology.1–7