This is gangrene (gangrenous necrosis).

Carotid artery: 'stroke' from cerebral infarction. Renal artery: renal infarction (but unlikely to cause renal failure due to large reserve capacity). Inferior mesenteric artery: possibly no effect because of large anastomosing blood supply to the bowel; might cause infarction if all mesenteric vessels had severe atherosclerosis. Hepatic artery: possibly no effect because of dual blood supply, but might cause infarction.

Insulin preparations are used mainly for type I diabetes mellitus for which there is an absolute lack of insulin.

1. Insulin is produced in the US by recombinant DNA technology with amino acid sequences that have distinctive pharmacokinetics to mimic physiologic insulin secretion. Insulin preparations are standardized as U-100 (100 units/mL). Insulin preparations can be subdivided into short acting (lispro, regular), intermediate acting (NPH, lente), and long acting (ultralente, glargine) forms.

2. Lispro is an insulin analogue with the 28th and 29th amino acids (lysine and proline) on the insulin beta chain reversed by recombinant DNA technology for full biologic activity but less tendency toward subcutaneous aggregation, resulting in more rapid absorption and onset of action and a shorter duration of action. Glargine differs from normal insulin by replacement of glycine by asparagine at amino acid 21 and addition of two arginine residues to the C-terminus of the beta chain.

3. Basal insulin requirements are provided by intermediate (NPH or lente) or long-acting (ultralente or glargine) insulin formulations. These are usually combined with short-acting insulin in an attempt to mimic physiologic insulin release with meals. Different forms may be mixed in the syringe immediately before injection.

Glucose-lowering agents are primarly used to treat type II diabetes mellitus, in which insulin is still present. Based on their mechanisms of action, oral glucose-lowering agents are subdivided into agents that increase insulin secretion, reduce glucose production, or increase insulin sensitivity.

1. Insulin secretagogues include the sulfonylureas that stimulate insulin secretion by interacting with the ATP-sensitive potassium channel on the beta cell and show greatest effectiveness in persons with recent onset (<5 years) type II DM who have endogenous insulin production and tend to be obese.

2. Biguanides such as metformin reduce hepatic glucose production through an undefined mechanism and may improve peripheral glucose utilization slightly, reduce fasting plasma glucose and insulin levels, improve the lipid profile, and promote modest weight loss.Glucosidase inhibitors such as acarbose and miglitol reduce postprandial hyperglycemia by delaying glucose absorption by inhibiting the enzyme that cleaves oligosaccharides into simple sugars in the intestinal lumen. They do not affect glucose utilization or insulin secretion .

3. Glucosidase inhibitors such as acarbose and miglitol reduce postprandial hyperglycemia by delaying glucose absorption by inhibiting the enzyme that cleaves oligosaccharides into simple sugars in the intestinal lumen. They do not affect glucose utilization or insulin secretion.

4. Thiazolidinediones (glitazones) such as pioglitazone reduce insulin resistance via binding to a nuclear receptor (the peroxisome proliferator activated receptor, or PPAR) that regulates gene transcription. The PPAR is found at highest levels in adipocytes but is expressed at lower levels in many other insulin-sensitive tissues. Thiazolidinediones reduce the fasting plasma glucose by improving peripheral glucose utilization and insulin sensitivity. The thiazolidinediones raise LDL and HDL slightly and lower triglycerides. Liver function should be checked in patients taking these drugs.