Homeostatic mechanisms for the control of the circulating hemoglobin level

Thesis (M.D.)--Boston Universit

Colonoscopy ‘My Way’: Preparation, Anticoagulants, Antibiotics and Sedation

Colonoscopy was introduced in the 1960s. The facility with which this technique is performed has been enhanced by vast improvements in instrumentation. In spite of this, physician attitudes concerning colonoscopy have changed little over the past several decades. The diet for precolonoscopic preparation has not been altered for 30 years. Colonoscopists have a great reluctance to use a new preparation instead of the 4 L electrolyte solution, perhaps because this was such a significant advance in colonoscopic cleansing, its predecessor being castor oil and enemas. Physicians continue to be wary of the patient who is taking acetylsalicylic acid in the absence of any studies that show that this is detrimental for polypectomy. The management of the patient on warfarin anticoagulation remains a subject for debate. As for antibiotic prophylaxis, most endoscopy units do not have a standardized approach, although there are good guidelines that, if followed, should decrease the risk of infective endocarditis. Sedation for the endoscopic examination is usually administered by the colonoscopist, although anesthesiologists may, in some countries (and in some defined areas of the United States) be the primary administrators of sedation and analgesia. The present article is a personal approach to the following issues: the preparation of the colon for an examination, current thoughts about anticoagulation and acetylsalicylic acid, antibiotic prophylaxis for colonoscopy and the technique for sedation out of the hospital

Colonoscopic Polypectomy

Colonoscopic polypectomy is a major advance in the therapy of colon neoplasms. The techniques for safe and efficient polyp removal are described. The uses of a variety of ancillary devices are discussed, including clips, loops, submucosal injection of fluid, and several thermal probes, including the argon plasma coagulator. The location of a lesion may be difficult to ascertain by intracolonic landmarks, but can be more precisely determined by X-ray, magnetic imaging, or intraoperative colonoscopy. Alternatively, it is possible to permanently mark the site of polyp removal with a carbon particle submucosal injection to facilitate subsequent localization either by surgery or interval colonoscopy

Tobacco, alcohol, and p53 overexpression in early colorectal neoplasia

Background: The p53 tumor suppressor gene is commonly mutated in colorectal cancer. While the effect of p53 mutations on colorectal cancer prognosis has been heavily studied, less is known about how epidemiologic risk factors relate to p53 status, particularly in early colorectal neoplasia prior to clinically invasive colorectal cancer (including adenomas, carcinoma in situ (CIS), and intramucosal carcinoma). Methods: We examined p53 status, as measured by protein overexpression, in 157 cases with early colorectal neoplasia selected from three New York City colonoscopy clinics. After collecting paraffin-embedded tissue blocks, immunohistochemistry was performed using an anti-p53 monoclonal mouse IgG2a [BP53-12-1] antibody. We analyzed whether p53 status was different for risk factors for colorectal neoplasia relative to a polyp-free control group (n = 508). Results: p53 overexpression was found in 10.3%, 21.7%, and 34.9%, of adenomatous polyps, CIS, and intramucosal cases, respectively. Over 90% of the tumors with p53 overexpression were located in the distal colon and rectum. Heavy cigarette smoking (30+ years) was associated with cases not overexpressing p53 (OR = 1.8, 95% CI = 1.1–2.9) but not with those cases overexpressing p53 (OR = 1.0, 95% CI = 0.4–2.6). Heavy beer consumption (8+ bottles per week) was associated with cases overexpressing p53 (OR = 4.0, 95% CI = 1.3–12.0) but not with cases without p53 overexpression (OR = 1.6, 95% CI = 0.7–3.7). Conclusion: Our findings that p53 overexpression in early colorectal neoplasia may be positively associated with alcohol intake and inversely associated with cigarette smoking are consistent with those of several studies of p53 expression and invasive cancer, and suggest that there may be relationships of smoking and alcohol with p53 early in the adenoma to carcinoma sequence

BMQ

BMQ: Boston Medical Quarterly was published from 1950-1966 by the Boston University School of Medicine and the Massachusetts Memorial Hospitals

Colonoscopy ‘My Way’: Preparation, Anticoagulants, Antibiotics and Sedation

Colonoscopy was introduced in the 1960s. The facility with which this technique is performed has been enhanced by vast improvements in instrumentation. In spite of this, physician attitudes concerning colonoscopy have changed little over the past several decades. The diet for precolonoscopic preparation has not been altered for 30 years. Colonoscopists have a great reluctance to use a new preparation instead of the 4 L electrolyte solution, perhaps because this was such a significant advance in colonoscopic cleansing, its predecessor being castor oil and enemas. Physicians continue to be wary of the patient who is taking acetylsalicylic acid in the absence of any studies that show that this is detrimental for polypectomy. The management of the patient on warfarin anticoagulation remains a subject for debate. As for antibiotic prophylaxis, most endoscopy units do not have a standardized approach, although there are good guidelines that, if followed, should decrease the risk of infective endocarditis. Sedation for the endoscopic examination is usually administered by the colonoscopist, although anesthesiologists may, in some countries (and in some defined areas of the United States) be the primary administrators of sedation and analgesia. The present article is a personal approach to the following issues: the preparation of the colon for an examination, current thoughts about anticoagulation and acetylsalicylic acid, antibiotic prophylaxis for colonoscopy and the technique for sedation out of the hospital