Emphysematous pyelonephritis: case report

We report a case of emphysematous pyelonephritis in a diabetic patient with some atypical features with a successful surgical outcome. This uncommon complication should be considered in any diabetic patient with fulminant or resistant pyelonephritis.     

Tigecycline: a case study

The emergence of pathogenic bacteria resistant to virtually all available antibacterial agents at present has caused consternation among medical professionals, but has only intermittently raised concern among the public. This has led to a transient resurgence of interest in studying the mechanisms of resistance and in discovering and developing new antibacterial agents, but successes in the development of novel antibacterial agents have been few and far between. Although it has been known since the discovery of the tetracyclines that they are inhibitors of protein synthesis, there has been considerable recent progress on elucidating the mechanisms of action of the tetracyclines and in the enhanced understanding of the mechanisms of tetracycline resistance. In this case study, the authors discuss the discovery and development of a new class of antibacterials, which were derived from the tetracyclines, namely the glycylcyclines. This has resulted in the introduction of a new agent, tigecycline, to clinical practice. The glycylcyclines restore the antibacterial activity to levels of the earlier tetracyclines when they were first introduced, by overcoming the two major tetracycline-resistance mechanisms of efflux and ribosome protection, which promises to have a high degree of clinical utility.     

Lead poisoning: case studies

Early clinical features of lead toxicity are non-specific and an occupational history is particularly valuable. Lead in the body comprises 2% in the blood (t1/2 35 days) and 95% in bone and dentine (t1/2 20-30 years). Blood lead may remain elevated for years after cessation from long exposure, due to redistribution from bone. Blood lead concentration is the most widely used marker for inorganic lead exposure. Zinc protoporphyrin (ZPP) concentration in blood usefully reflects lead exposure over the prior 3 months. Symptomatic patients with blood lead concentration >2.4 micromol l-1 (50 microg dl-1) or in any event >3.8 micromol l-1 (80 microg dl-1) should receive sodium calciumedetate i.v., followed by succimer by mouth for 19 days. Asymptomatic patients with blood lead concentration >2.4 micromol l-1 (50 microg dl-1) may be treated with succimer alone. Sodium calciumedetate should be given with dimercaprol to treat lead encephalopathy.     

Pharmacological prevention of migraine: to be considered case by case

(1) Migraines are characterized by recurrent headaches generally lasting between 4 and 72 hours and disappearing without complication. They can be incapacitating, owing to their frequency and/or intensity. (2) Many drugs have been used to prevent migraines. One of the most common outcome measures used in clinical trials is the proportion of responder patients, defined as those in whom the monthly frequency of migraines is at least halved. On average, about one-third of patients respond to placebo in clinical trials. (3) Propranolol is the betablocker with the best-documented efficacy: in absolute terms the response rate is about 30% higher than with placebo. The adverse effects of betablockers are mainly cardiovascular and neuropsychological. (4) Valproic acid, an anticonvulsant, is about as effective as propranolol, and its adverse effects are generally acceptable. (5) Amitriptyline is the antidepressant with the best-documented preventive effects, with a response rate about 20% higher than placebo. Its principal adverse effects are due to its atropinic action. Amitriptyline can also have a sedative effect. (6) Flunarizine also has documented efficacy, but this "hidden neuroleptic" can cause extrapyramidal disorders and weight gain. (7) Among the serotonergic antagonists, methysergide has documented efficacy but long-term treatment can lead to serious retroperitoneal, pulmonary or cardiac fibrosis. Pizotifen causes drowsiness or weight gain in about 50% of patients. (8) The choice of preventive treatment for migraine must be based on the balance between efficacy (compared to placebo) and adverse effects. In practice, the first choice drug is propranolol. (9) Because the frequency of migraines fluctuates over time, withdrawal of prophylaxis should be attempted on a regular basis, with the patient's consent.