Cachexia is a debilitating condition characterized by extreme skeletal muscle wasting that contributes significantly to morbidity and mortality. Efforts to elucidate the underlying mechanisms of muscle loss have predominantly focused on events intrinsic to the myofiber. In contrast, less regard has been given to potential contributory factors outside the fiber within the muscle microenvironment. In tumor-bearing mice and patients with pancreatic cancer, we found that cachexia was associated with a type of muscle damage resulting in activation of both satellite and nonsatellite muscle progenitor cells. These muscle progenitors committed to a myogenic program, but were inhibited from completing differentiation by an event linked with persistent expression of the self-renewing factor Pax7. Overexpression of Pax7 was sufficient to induce atrophy in normal muscle, while under tumor conditions, the reduction of Pax7 or exogenous addition of its downstream target, MyoD, reversed wasting by restoring cell differentiation and fusion with injured fibers. Furthermore, Pax7 was induced by serum factors from cachectic mice and patients, in an NF-κB-dependent manner, both in vitro and in vivo. Together, these results suggest that Pax7 responds to NF-κB by impairing the regenerative capacity of myogenic cells in the muscle microenvironment to drive muscle wasting in cancer.

Sarcopenia is the subclinical loss of skeletal muscle and strength and has been extensively studied in both the cancer and surgical literature. Specifically, sarcopenia has gained significant recognition as an important prognostic factor for both complications and survival in cancer patients. Herein, we review the current literature to date highlighting the specific impact of sarcopenia in patients undergoing oncologic procedures.

In this population, the average age of sarcopenic patients is increased from those who do not meet criteria. Among patients younger than 40 years, sarcopenia affects surgical outcomes. Assessment of sarcopenia can be used to improve preoperative management and describe risks before surgery in patients with IBD.

In an effort to make laparoscopic suturing more efficient, the V-Loc advanced wound closure device (Covidien, Mansfield, MA) has been produced. This device is a self-anchoring barbed suture that obviates the need for knot tying. The goal of this initial feasibility study was to investigate the use of the barbed suture in gastrointestinal enterotomy closure. A randomized study of 12 pigs comparing enterotomy closure with barbed versus a nonbarbed suture of similar tensile strength was performed. To this end, 25 mm enterotomies were made in the stomach (1 control, 1 treatment), jejunum (2 controls, 2 treatments), and descending colon (1 control, 1 treatment). Animals were killed at 3, 7, and 14 days postoperatively (4 each group) and their gastrointestinal tracts harvested; 6 of the 8 enterotomies from each pig underwent burst strength testing. The remaining 2 were fixed in formalin and sent for histological examination. All 12 pigs survived until they were killed without any major complications. Enterotomy closure with barbed suture revealed adhesion scores, burst strength pressures, and histology scores that were similar to those for the control. Jejunal closures resulted in 6 failures at 7 days (3 control, 3 barbed) and 4 failures at 14 days (2 control, 2 barbed). The barbed suture significantly reduced suturing time in the stomach, jejunum, and colon. The V-Loc wound closure device appears to offer comparable gastrointestinal closure to 3-0 Maxon while being significantly faster. Further studies with V-Loc are required to assess its use in laparoscopic surgery.

Numerous metabolic adaptations occur in the heart after birth. Important transcription factors that regulate expression of the glycolytic and mitochondrial oxidative genes are hypoxia-inducible factors (HIF-1alpha and -2alpha) and nuclear respiratory factor-1 (NRF-1). The goal of this study was to examine expression of HIF-1alpha, HIF-2alpha, and NRF-1 and the genes they regulate in pre- and postnatal myocardium. Ovine right and left ventricular myocardium was obtained at four time points: 95 and 140 d gestation (term = 145 d) and 7 d and 8 wk postnatally. Steady-state mRNA and protein levels of HIF-1alpha and NRF-1 and protein levels of HIF-2alpha were measured along with mRNA of HIF-1alpha-regulated genes (aldolase A, alpha- and beta-enolase, lactate dehydrogenase A, liver and muscle phosphofructokinase) and NRF-1-regulated genes (cytochrome c, Va subunit of cytochrome oxidase, and carnitine palmitoyltransferase I ). HIF-1alpha protein was present in fetal myocardium but dropped below detectable levels at 7 d postnatally. HIF-2alpha protein levels were similar at the four time points. Steady-state mRNA levels of alpha-enolase, lactate dehydrogenase A, and liver phosphofructokinase declined significantly postnatally. Aldolase A, beta-enolase, and muscle phosphofructokinase mRNA levels increased postnatally. Steady-state mRNA and protein levels of NRF-1 decreased postnatally in contrast to the postnatal increases in cytochrome c, subunit Va of cytochrome oxidase, and carnitine palmitoyltransferase I mRNA levels. The in vivo postnatal regulation of enzymes encoding glycolytic and mitochondrial enzymes is complex. As transactivation response elements for the genes encoding metabolic enzymes continue to be characterized, studies using the fetal-to-postnatal metabolic transition of the heart will continue to help define the in vivo role of these transcription factors.