Lower-extremity soft tissue infections with intra-abdominal sources.

This article describes a series of 3 patients who presented with lower-extremity soft tissue infections. Each patient was treated with prompt debridement by an orthopedic surgeon (J.F.G.) and required at least 1 additional procedure by another surgeon.These infections vary from superficial cellulitis to rapidly advancing necrotizing fasciitis. At times, the source of these infections is clear. Other times, no obvious source of infection exists, in which case the abdomen must be considered as a possible source of infection. A high level of suspicion, complete history and physical examination, and appropriate ancillary studies are required to make an accurate and prompt diagnosis. Options for the treatment of the intra-abdominal source of infection depend on the etiology of the infection and anatomic location of the process. Psoas abscesses can often be decompressed by an interventional radiologist using computed tomography guidance. In the case of bowel involvement, such as suspected carcinoma or diverticulitis, a general surgeon is necessary. When the appropriate diagnosis is made, soft tissue infections of the thigh often respond to appropriate surgical debridement and antibiotic therapy. It is important to remember the whole patient when evaluating soft tissue infections, especially in the thigh. A low threshold for imaging of the abdomen and pelvis is important, especially when the physical examination or medical history reveals the abdomen as a possible source of infection.

Immediate spica casting of pediatric femoral fractures in the operating room versus the emergency department: comparison of reduction, complications, and hospital charges.

BACKGROUND: Immediate spica casting for pediatric femur fractures is well described as a standard treatment in the literature. The purpose of this study is to evaluate the application of a spica cast in the emergency department (ED) versus the operating room (OR) with regard to quality of reduction, complications, and hospital charges at an academic institution. METHODS: An institutional review board-approved retrospective review identified 100 children aged 6 months to 5 years between January 2003 and October 2008 with an isolated femur fracture treated with a hip spica cast. Patients were compared based on the setting of spica cast application. RESULTS: There were 79 patients in the ED cohort and 21 patients in the OR cohort. There were no significant differences in age, weight, sex, fracture pattern, prereduction shortening, injury mechanism, duration of spica treatment, time to heal, or length of follow-up between cohorts. There were no significant differences in the rate of loss of reduction requiring revision casting or operative treatment (6.3% vs. 4.8%), the need for cast wedging (8.9% vs. 14.3%), or minor skin breakdown (12.7% vs. 14.3%). There were no sedation or anesthetic complications in either group. There were no significant differences in the quality of reduction or the rate of complications between the 2 groups. Spica casting in the OR delayed the time from presentation to cast placement as compared with the ED cohort (11.5 h vs. 3.8 h, P<0.0001) and lengthened the hospital stay (30.5 h vs. 16.9 h, P=0.0002). The average hospital charges of spica cast application in the OR was 3 times higher than the cost of casting in the ED ($15,983 vs. $5150, P<0.0001). CONCLUSIONS: Immediate spica casting in the ED and OR provide similar results in terms of reduction and complications. With the significantly higher hospital charges for spica casting in the OR, alternative settings should be considered. LEVEL OF EVIDENCE: III--Retrospective comparative study.

NPH4/ARF7 and ARF19 promote leaf expansion and auxin-induced lateral root formation.

Auxin response factors (ARFs) bind auxin response promoter elements and mediate transcriptional responses to auxin. Five of the 22 ARF genes in Arabidopsis thaliana encode ARFs with glutamine-rich middle domains. Four of these can activate transcription and have been ascribed developmental functions. We show that ARF19, the fifth Q-rich ARF, also activates transcription. Mutations in ARF19 have little effect on their own, but in combination with mutations in NPH4/ARF7, encoding the most closely related ARF, they cause several phenotypes including a drastic decrease in lateral and adventitious root formation and a decrease in leaf cell expansion. These results indicate that auxin induces lateral roots and leaf expansion by activating NPH4/ARF7 and ARF19. Auxin induces the ARF19 gene, and NPH4/ARF7 and ARF19 together are required for expression of one of the arf19 mutant alleles, suggesting that a positive feedback loop regulates leaf expansion and/or lateral root induction.

Developmental specificity of auxin response by pairs of ARF and Aux/IAA transcriptional regulators.

The plant hormone auxin elicits many specific context-dependent developmental responses. Auxin promotes degradation of Aux/IAA proteins that prevent transcription factors of the auxin response factor (ARF) family from regulating auxin-responsive target genes. Aux/IAAs and ARFs are represented by large gene families in Arabidopsis. Here we show that stabilization of BDL/IAA12 or its sister protein IAA13 prevents MP/ARF5-dependent embryonic root formation whereas stabilized SHY2/IAA3 interferes with seedling growth. Although both bdl and shy2-2 proteins inhibited MP/ARF5-dependent reporter gene activation, shy2-2 was much less efficient than bdl to interfere with embryonic root initiation when expressed from the BDL promoter. Similarly, MP was much more efficient than ARF16 in this process. When expressed from the SHY2 promoter, both shy2-2 and bdl inhibited cell elongation and auxin-induced gene expression in the seedling hypocotyl. By contrast, gravitropism and auxin-induced gene expression in the root, which were promoted by functionally redundant NPH4/ARF7 and ARF19 proteins, were inhibited by shy2-2, but not by bdl protein. Our results suggest that auxin signals are converted into specific responses by matching pairs of coexpressed ARF and Aux/IAA proteins.