Time course of human skeletal muscle nitrate and nitrite concentration changes following dietary nitrate ingestion.

Dietary nitrate (NO3-) ingestion can be beneficial for health and exercise performance. Recently, based on animal and limited human studies, a skeletal muscle NO3- reservoir has been suggested to be important in whole body nitric oxide (NO) homeostasis. The purpose of this study was to determine the time course of changes in human skeletal muscle NO3- concentration ([NO3-]) following the ingestion of dietary NO3-. Sixteen participants were allocated to either an experimental group (NIT: n = 11) which consumed a bolus of ∼1300 mg (12.8 mmol) potassium nitrate (KNO3), or a placebo group (PLA: n = 5) which consumed a bolus of potassium chloride (KCl). Biological samples (muscle (vastus lateralis), blood, saliva and urine) were collected shortly before NIT or PLA ingestion and at intervals over the course of the subsequent 24 h. At baseline, no differences were observed for muscle [NO3-] and [NO2-] between NIT and PLA (P > 0.05). In PLA, there were no changes in muscle [NO3-] or [NO2-] over time. In NIT, muscle [NO3-] was significantly elevated above baseline (54 ± 29 nmol/g) at 0.5 h, reached a peak at 3 h (181 ± 128 nmol/g), and was not different to baseline from 9 h onwards (P > 0.05). Muscle [NO2-] did not change significantly over time. Following ingestion of a bolus of dietary NO3-, skeletal muscle [NO3-] increases rapidly, reaches a peak at ∼3 h and subsequently declines towards baseline values. Following dietary NO3- ingestion, human m. vastus lateralis [NO3-] expressed a slightly delayed pharmacokinetic profile compared to plasma [NO3-].

Lymphovascular invasion is associated with survival for papillary thyroid cancer.

Data are limited regarding the association between tumor lymphovascular invasion and survival for patients with papillary thyroid cancer (PTC). This study sought to examine lymphovascular invasion as an independent prognostic factor for patients with PTC undergoing thyroid resection. The National Cancer Data Base (2010-2011) was queried for patients with PTC who underwent total thyroidectomy or lobectomy. Patients were classified into two groups based on the presence/absence of lymphovascular invasion. Demographic, clinical and pathological features were evaluated for all patients. A Cox proportional hazards model was utilized to identify factors associated with survival. Results show that 45,415 patients met inclusion criteria; 11.6% had lymphovascular invasion. Patients with lymphovascular invasion were more likely to have larger tumors (2.8cm vs 1.5cm, P<0.01), metastatic lymph nodes (74.1% vs 32.5%, P<0.01), and distant metastases (3.0% vs 0.5%, P<0.01). They were also more likely to receive radioactive iodine (69.3% vs 44.9%, P<0.01). Unadjusted overall 5-year survival was lower for patients who had tumors with lymphovascular invasion (86.6% vs 94.5%) (log-rank P<0.01). After adjustment, increasing patient age (HR=1.06, P<0.01), male gender (HR=1.68, P<0.01), presence of metastatic lymph nodes (HR=1.77, P<0.01), distant metastases (HR=3.49, P<0.01), and lymphovascular invasion (HR=1.88, P<0.01) were associated with compromised survival. For patients with lymphovascular invasion, treatment with RAI was associated with reduced mortality (HR=0.43, P<0.01). The presence of lymphovascular invasion among patients with PTC is independently associated with compromised survival. Patients who have PTC with lymphovascular invasion should be considered higher risk, and adjuvant RAI should be more strongly considered.

Absence of CHEK2*1100delC mutation in families with hereditary breast cancer in North America.

The CHEK2*1100delC mutation has been reported to confer a twofold increased risk of breast cancer among carriers. The frequency of the mutation varies among populations. The highest frequency has been described in Northern and Eastern European countries; the frequency may be much lower in North America. In this study, our aim was to determine the frequency of CHEK2*1100delC in members of breast cancer families who tested negative for a deleterious mutation in BRCA1/2 at the University of Michigan Comprehensive Cancer Center. We genotyped 102 members from 90 families for CHEK2*1100delC. Most of these families had several cases of breast cancer or ovarian cancer (or both), as well as multiple members with other cancer types in a single lineage. No CHEK2*1100delC mutations were detected in any of the 102 individuals, including 51 women diagnosed with breast cancer at an early age (<45 years), 8 women with bilateral breast cancer, 3 men with breast cancer, and 8 women with ovarian cancer. Our data are consistent with the reported very low frequency of CHEK2*1100delC mutations in North American populations (compared with Northern Europe), rendering CHEK2*1100delC such an unlikely culprit in BRCA1/2 negative families that routine testing of these families appears unwarranted.