The functional and anatomical characterization of three spinal output pathways of the anterolateral tract.

The nature of spinal output pathways that convey nociceptive information to the brain has been the subject of controversy. Here, we provide anatomical, molecular, and functional characterizations of two distinct anterolateral pathways: one, ascending in the lateral spinal cord, triggers nociceptive behaviors, and the other one, ascending in the ventral spinal cord, when inhibited, leads to sensorimotor deficits. Moreover, the lateral pathway consists of at least two subtypes. The first is a contralateral pathway that extends to the periaqueductal gray (PAG) and thalamus; the second is a bilateral pathway that projects to the bilateral parabrachial nucleus (PBN). Finally, we present evidence showing that activation of the contralateral pathway is sufficient for defensive behaviors such as running and freezing, whereas the bilateral pathway is sufficient for attending behaviors such as licking and guarding. This work offers insight into the complex organizational logic of the anterolateral system in the mouse.

Medication and nutrient administration considerations after bariatric surgery.

PURPOSE: Medication and nutrient administration considerations after bariatric surgery are discussed. SUMMARY: Bariatric surgery is categorized by surgical technique (i.e., restrictive procedure or a combination of restrictive and malabsorptive procedures). Roux-en-Y gastric bypass is the most frequently performed bariatric surgery in the United States. Patients who have undergone this surgery are at risk for nutrient deficiencies. Several factors, such as pH and absorption sites, should be considered when providing these patients with appropriate supplementation. Drug solubility and surface area for absorption are also affected by gastric bypass procedures. By bypassing major portions of the small intestine, Roux-en-Y procedures drastically reduce the surface area for absorption. These changes may warrant manipulation in drug route or dose to ensure adequate delivery. Drugs with long absorptive phases that remain in the intestine for extended periods are likely to exhibit decreased bioavailability in these patients. The reduced size of the stomach after surgery can place patients at risk for adverse events associated with some medications. Medications implicated in such adverse events include nonsteroidal antiinflammatory drugs, salicylates, and oral bisphosphonates. Drugs that are rapidly and primarily absorbed in the stomach or duodenum are likely to exhibit decreased absorption in patients who have had combination restrictive-malabsorptive procedures. Because reduced drug absorption may result in decreased efficacy rather than toxicity, increased patient monitoring for therapeutic effects can help detect potential absorption problems. CONCLUSION: Selection of appropriate nutrient salts can improve nutrient replacement in patients who have undergone bariatric surgery. Changes in dosage forms based on drug characteristics can improve bioavailability.

Isotretinoin in the treatment of granuloma annulare.

OBJECTIVE: To assess the utility and safety of isotretinoin in the treatment of granuloma annulare (GA). DATA SOURCES: Searches of MEDLINE (1966-January 2003), EMBASE (1989-January 2003), International Pharmaceutical Abstracts (1970-2002), and Allied and Complementary Medicine Database (1985-2002) were conducted. Key terms included granuloma annulare, isotretinoin, retinoids, and antioxidants. DATA SYNTHESIS: Isotretinoin may have proliferative and inhibitory effects on collagen synthesis that improve GA symptoms. Cases reporting use of isotretinoin in the treatment of GA were reviewed. Several reports detail the successful use of isotretinoin 0.5-1 mg/kg/day, primarily in the disseminated form of the disease. However, some patients required dosage decreases in response to drug-related liver function test elevations, and 2 instances of drug failure were identified. CONCLUSIONS: Isotretinoin should be reserved for patients with disseminated or refractory GA. Potential serious adverse effects associated with its use require careful monitoring.