Mitotic Index is an Independent Predictor of Recurrence‐Free Survival in Meningioma

While World Health Organization (WHO) grading of meningioma stratifies patients according to recurrence risk overall, there is substantial within‐grade heterogeneity with respect to recurrence‐free survival (RFS). Most meningiomas are graded according to mitotic counts per unit area on hematoxylin and eosin sections, a method potentially confounded by tumor cellularity, as well as potential limitations of accurate mitotic figure detection on routine histology. To refine mitotic figure assessment, we evaluated 363 meningiomas with phospho‐histone H3 (Ser10) and determined the mitotic index (number of mitoses per 1000 tumor cells). The median mitotic indices among WHO grade I (n = 268), grade II (n = 84) and grade III (n = 11) tumors were 1, 4 and 12. Classification and regression tree analysis to categorize cut‐offs identified three subgroups defined by mitotic indices of 0–2, 3–4 and ≥5, which on univariate analysis were associated with RFS (P < 0.01). In multivariate analysis, mitotic index subgrouped in this manner was significantly associated with RFS (P < 0.01) after adjustment for Simpson grade, WHO grade and MIB‐1 index. Mitotic index was then examined within individual WHO grade, showing that for grade I and grade II meningiomas, mitotic index can add additional information to RFS risk. The results suggest that the use of a robust mitotic marker in meningioma could refine risk stratification.     

Cardiovascular magnetic resonance left ventricular strain in end-stage renal disease patients after kidney transplantation

Background

Cardiovascular disease is a significant cause of morbidity and mortality in patients with end-stage renal disease (ESRD) and kidney transplant (KT) patients. Compared with left ventricular (LV) ejection fraction (LVEF), LV strain has emerged as an important marker of LV function as it is less load dependent. We sought to evaluate changes in LV strain using cardiovascular magnetic resonance imaging (CMR) in ESRD patients who received KT, to determine whether KT may improve LV function.

Methods

We conducted a prospective multi-centre longitudinal study of 79 ESRD patients (40 on dialysis, 39 underwent KT). CMR was performed at baseline and at 12?months after KT.

Results

Among 79 participants (mean age 55 years; 30% women), KT patients had significant improvement in global circumferential strain (GCS) (p?=?0.007) and global radial strain (GRS) (p?=?0.003), but a decline in global longitudinal strain (GLS) over 12?months (p?=?0.026), while no significant change in any LV strain was observed in the ongoing dialysis group. For KT patients, the improvement in LV strain paralleled improvement in LVEF (57.4?±?6.4% at baseline, 60.6%?±?6.9% at 12?months; p?=?0.001). For entire cohort, over 12?months, change in LVEF was significantly correlated with change in GCS (Spearman’s r?=???0.42, p?<?0.001), GRS (Spearman’s r?=?0.64, p?<?0.001), and GLS (Spearman’s r?=???0.34, p?=?0.002). Improvements in GCS and GRS over 12?months were significantly correlated with reductions in LV end-diastolic volume index and LV end-systolic volume index (all p?<?0.05), but not with change in blood pressure (all p?>?0.10).

Conclusions

Compared with continuation of dialysis, KT was associated with significant improvements in LV strain metrics of GCS and GRS after 12?months, which did not correlate with blood pressure change. This supports the notion that KT has favorable effects on LV function beyond volume and blood pessure control. Larger studies with longer follow-up are needed to confirm these findings.

     

Impact of renal insufficiency on short- and long-term outcomes after cardiac surgery

Background

Renal insufficiency is highly prevalent in North America and has been established as a nontraditional risk factor for cardiovascular disease. Cardiovascular disease remains the primary cause of mortality in the general population and is often treated with coronary artery bypass surgery (CABG). This population-based study aimed to determine the risk of nondialysis dependent renal insufficiency (RI) on the long-term outcomes of patients who undergo CABG.

Methods

Prospectively collected data from 26,506 patients were abstracted from the Cardiac Care Network database from 9 revascularization hospitals in Ontario, Canada. Multivariate regression analysis examined associations between preoperative RI and inhospital, 30-day, and 1-year mortality according to 3 levels of serum creatinine: <120 μmol/L (normal), 120 to 180 μmol/L (mild RI), and >180 μmil/L (moderate-severe RI) and 5 levels of creatinine clearance (Cockcroft-Gault): >100 mL/min (normal), 80 to 99 mL/min (mild impairment), 60 to 79 mL/min (mild-moderate impairment), 40 to 59 mL/min (moderate impairment), and <40 mL/min (severe impairment).

Results

The overall inhospital, 30-day, and 1-year mortality rates were 1.90%, 2.0%, and 4.5%, respectively. Patients with RI had greater overall comorbidity. After adjustment for confounding factors, RI was associated with the greater risk of both 30-day (odds ratio 3.7, 95% CI 2.3-5.8, P < .0001) and 1-year mortality (odds ratio 4.6, 95% CI 3.3-6.4, P < .0001).

Conclusion

Preoperative renal impairment should be recognized as a significant risk factor for mortality after CABG. A trend of increasing risk with severity of renal impairment was demonstrated for both 30-day and 1-year mortality in this large, population-based study.     

A composite bacteriophage alters colonization by an intestinal commensal bacterium

The mammalian intestine is home to a dense community of bacteria and its associated bacteriophage (phage). Virtually nothing is known about how phages impact the establishment and maintenance of resident bacterial communities in the intestine. Here, we examine the phages harbored by Enterococcus faecalis, a commensal of the human intestine. We show that E. faecalis strain V583 produces a composite phage (ϕV1/7) derived from two distinct chromosomally encoded prophage elements. One prophage, prophage 1 (ϕV1), encodes the structural genes necessary for phage particle production. Another prophage, prophage 7 (ϕV7), is required for phage infection of susceptible host bacteria. Production of ϕV1/7 is controlled, in part, by nutrient availability, because ϕV1/7 particle numbers are elevated by free amino acids in culture and during growth in the mouse intestine. ϕV1/7 confers an advantage to E. faecalis V583 during competition with other E. faecalis strains in vitro and in vivo. Thus, we propose that E. faecalis V583 uses phage particles to establish and maintain dominance of its intestinal niche in the presence of closely related competing strains. Our findings indicate that bacteriophages can impact the dynamics of bacterial colonization in the mammalian intestinal ecosystem.