Smaller rectus femoris size measured by ultrasound is associated with poorer outcomes after cardiac surgery

OBJECTIVE

We sought to evaluate the association of low rectus femoris cross-sectional area (RFCSA) with hospital length of stay and poorer outcomes in patients undergoing cardiac surgery.

METHODS

A single right-leg RFCSA was measured with ultrasound preoperatively and baseline characteristics, clinical data, and outcomes recorded. Patients were categorized as low rectus femoris muscle size (lowRF) or normal rectus femoris muscle size (normalRF), if they were in the lowest quartile or not, respectively. All analyses were performed on both body surface area (BSA)- and sex-adjusted RFCSA.

RESULTS

One hundred eight-four patients had a RFCSA measured with a mean of 5.01 cm2 (1.41 cm2), and range of 0.71 to 8.77 cm2. When analyzing the BSA-adjusted RFCSA, we found the lowRF group had a longer hospital stay, 11.0 days [7.0-16.3] versus 8.0 days [6.0-10.0] for the normalRF group (P < .001), and a greater proportion of extended hospital stay (≥18.5 days) of 19.6% compared with 6.2% (P = .010). When the RFCSA was adjusted for sex, the lowRF group had a greater length of hospital stay, 9.0 days [7.0-14.5] versus 8.0 days [6.0-11.0] (P = .049). In both the BSA- and sex-adjusted RFCSA, the lowRF group suffered greater morbidity and were more likely discharged to a destination other than home. In multivariate analyses adjusting for European System for Cardiac Operative Risk Evaluation II, BSA-adjusted lowRF but not sex-adjusted lowRF was independently associated with log-transformed hospital length of stay. LowRF was not independently associated with increased major morbidity and death for both BSA and sex-adjusted RFCSA.

CONCLUSIONS

Low RFCSA has a significant association with increased hospital length of stay, morbidity, and nonhome discharge in patients undergoing cardiac procedures.

TRIAL REGISTRY NUMBER

ACTRN12620000678998.

Pick bodies in a family with presenilin-1 Alzheimer's disease

Presenilin-1 (PS-1) mutations can cause Pick's disease without evidence of Alzheimer's disease (AD). We describe a family with a PS-1 M146L mutation and both Pick bodies and AD. Sarkosyl-insoluble hyperphosphorylated tau showed three bands consistent with AD, although dephosphorylation showed primarily three-repeat isoforms. M146L mutant PS-1 may predispose to both Pick's disease and AD by affecting multiple intracellular pathways involving tau phosphorylation and amyloid metabolism.

A transcriptional regulatory element common to a large family of hepatic cytochrome P450 genes is a functional binding site of the orphan receptor HNF-4

Hepatic cytochrome P450 (CYP) genes, including members of CYP1 to CYP4 families, comprise the majority of the CYP gene superfamily. Previous study has demonstrated that HepG2-specific transcriptional activation of two CYP2C genes was dependent on a common element that bound a HepG2 nuclear protein designated HPF-1 (Venepally, P., Chen, D., and Kemper, B. (1992) J. Biol. Chem. 267, 17333-17338). This cis-acting element is highly homologous to the hepatocyte nuclear factor 4 (HNF-4) binding motif and is present in the promoters of more than 20 other CYP2 genes. To investigate the relationship between HPF-1 and HNF-4, we have compared their tissue distribution, DNA binding, and immunochemical characteristics, as well as transcriptional activity of their recognition elements. DNase I footprint analyses and gel-shift assays indicated that HPF-1, like HNF-4, was present in liver and kidney, but not brain and spleen. Both factors bound to either the HPF-1 site in the CYP2C2 promoter or an HNF-4 site in the human apolipoprotein CIII promoter. These complexes could be "supershifted" by an antiserum specific for HNF-4. When the sequence of the HPF-1 site in the CYP2C2 promoter was changed to that of the apolipoprotein CIII HNF-4 site, comparable transcriptional activities were obtained with the wild-type promoter and the HNF-4 mutant in transfected HepG2 cells. Cotransfection of HNF-4 with CYP2C2 promoter-luciferase constructs in COS-1 cells indicated that HNF-4 could trans-activate the promoters containing the HPF-1 site. These results indicate that the HPF-1 motif is a functional HNF-4-binding site, and the common immunological properties indicate that HPF-1 and HNF-4 are closely related and possibly identical. HNF-4, therefore, may act as a common regulator for the liver-specific expression of many CYP2 genes.

Insulin rapidly induces rat liver S14 gene transcription

We evaluated the role insulin plays in the regulation of hepatic S14 gene transcription using the streptozotocin-induced diabetic rat model. Nuclear run-on activity and mRNAS14 levels were reduced by more than 85% in diabetic rats compared to those in intact animals. After the administration of insulin, both S14 run-on activity and mRNAS14 levels were rapidly induced. Within 1 h of insulin administration, S14 run-on activity and mRNAS14 were induced 5- and 8-fold, respectively. S14 gene expression was restored to intact levels within 4 h, with overall increases in run-on activity and mRNAS14 of 7- and 20-fold, respectively. The full induction of mRNAS14 cannot be accounted for solely by activation of S14 gene transcription, implicating insulin effects at the posttranscriptional level. However, our results show that the principal target for insulin action on the S14 gene is transcriptional. Administration of dibutryl cAMP and theophylline fully blocked the insulin-mediated increase in S14 gene transcription, indicating that hepatic cAMP levels play a dominant negative role in regulating S14 gene transcription in vivo. Fructose administration to starved diabetic rats induced only a marginal 60% increase in mRNAS14 and S14 run-on activity within 4 h, while insulin plus fructose or insulin plus glucose fully restored S14 gene expression to intact levels within the same time period. Thus, dietary fructose or a metabolite generated from fructose alone cannot induce S14 gene transcription or mRNAS14 to intact levels in the starved diabetic rat. Acute effects of dietary carbohydrate on hepatic S14 gene transcription are insulin dependent.(ABSTRACT TRUNCATED AT 250 WORDS)

Transcriptional activation of the rat liver S14 gene during postnatal development

The mRNA coding for the rat liver S14 protein (Mr 17,000, pI 4.9) shows profound increases during postnatal development. In an effort to define the molecular basis for the postnatal rise in mRNAs14 we examined the chromatin organization of the S14 gene, its DNA methylation state, the hepatic expression of mRNAs14, and the in vitro S14 "run-on" activity prior to and after weaning at 21 days postpartum. In animals less than or equal to 15 days of age, the hepatic S14 gene is transcriptionally inactive, mRNAs14 levels are less than or equal to 0.5% of adult levels, and the chromatin organization within 11 kilobases of the 5' end of the S14 gene is similar to that found in tissues not expressing mRNAs14. From 18 to 22 days postpartum, the transcriptional activity of the S14 gene increases greater than or equal to 40-fold and mRNAs14 increases greater than or equal to 100-fold approaching adult levels of expression. Highly specific changes in S14 chromatin structure accompany gene activation. The formation of Hss-1 near the S14 cap site (-65 to -265 base pairs) and Hss-3 -3.3 kilobases upstream from the S14 cap site suggests that changes in DNA-protein interaction at these sites may function in both the tissue-specific and developmental regulation of S14 gene expression. The methylation studies suggest HhaI sites may be a cue for the tissue-specific expression of S14. However, the maintenance of hypermethylated HpaII sites throughout S14 gene activation argues against a role for these sites in either the tissue-specific or developmental regulation of S14 gene expression. These studies show that the principal molecular mechanism accounting for the major rise in mRNAs14 during postnatal development is activation of gene transcription and not stabilization of S14 RNA.