Influence of preoperative docetaxel, cisplatin, and 5-fluorouracil on the incidence of complications after esophagectomy for resectable advanced esophageal cancer

A limited number of patients with resectable advanced esophageal cancer can be cured by surgery alone. Although a regimen that consists of docetaxel, cisplatin, and 5-fluorouracil (DCF) is a potential preoperative chemotherapy (PCT) option for squamous cell carcinoma of the esophagus, the influence of DCF on subsequent esophagectomies remains unclear. A total of 80 patients who received preoperative DCF chemotherapy, and 174 patients who did not receive any preoperative treatment were retrospectively analyzed. There were no treatment-related deaths. No delays in surgery due to adverse events related to DCF were reported. Although patients who received PCT had significantly more advanced cancers and worse preoperative conditions, the incidence rates of complications did not increase. Although the frequency of severe complications was significantly higher in patients who received PCT, this treatment was not an independent factor for the occurrence of severe complications. PCT with DCF did not negatively affect subsequent esophagectomies with regard to the frequency of complications.

Methylation levels of LINE-1 in primary lesion and matched metastatic lesions of colorectal cancer

Background:

LINE-1 methylation level is a surrogate marker of global DNA methylation. LINE-1 methylation in primary colorectal cancers (CRCs) is highly variable and strongly associated with a poor prognosis. However, no study has examined LINE-1 methylation levels of metastatic CRCs in relation to prognosis or assessed the heterogeneity of LINE-1 methylation level within the primary CRCs.

Methods:

Pyrosequencing was used to quantify LINE-1 methylation level in 42 liver metastases, 26 matched primary tumours, and 6 matched lymph node (LN) metastases. KRAS, BRAF, and PIK3CA mutation status and microsatellite instability (MSI) status were also examined.

Results:

The distribution of LINE-1 methylation level in liver metastases was as follows: mean, 67.3; range, 37.1–90.1. Primary tumours showed LINE-1 methylation levels similar to those of matched liver and LN metastases. The difference in LINE-1 methylation level between superficial areas and invasive front areas was within 7.0 in all six cases evaluated. Prognostic impact of LINE-1 hypomethylation in liver metastases on overall survival was not observed. The concordance rate was 94% for KRAS, 100% for BRAF, 88% for PIK3CA, and 97% for MSI.

Conclusion:

Alteration of LINE-1 methylation level may occur in early CRC tumorigenesis, and the LINE-1 methylation level is relatively stable during CRC progression.

Ab initio calculations of deuterium isotope effects on chemical shifts of salt-bridged lysines

Deuterium isotope effects measure the change in chemical shift on substitution of a proton by deuterium. They have been calculated by direct treatment of the H/D nuclear quantum effect using a multicomponent ab initio molecular orbital method based on a non-Born-Oppenheimer approximation. This method enables the determination of both the electronic and the protonic (deuteronic) wave functions simultaneously and can directly calculate the geometrical difference induced by H/D isotope effects. The calculations show that the one-bond deuterium isotope effects on (15)N nuclear shielding, (1)Δ(15)N(D), in ammonium and amines decrease as a counterion or water molecule moves closer to the nitrogen. (1)Δ(15)N(D) and (2)Δ(1)H(D) of the NH(3)(+) groups of lysine residues in the B1 domain of protein G have been calculated using truncated side chains and also determined experimentally by NMR. Comparisons show that the structures in solution are different from those in the crystal and that solvation plays an important role in weakening the hydrogen bonds.

Echocardiographic characteristics and causal mechanism of physiologic mitral regurgitation in young normal subjects

BACKGROUND

It has become evident that mitral regurgitation (MR) is not uncommon in healthy subjects, and Doppler color flow mapping is a technique that imparts important information relevant to its detection.

HYPOTHESIS

Using transthoracic echocardiography, this study evaluated the mechanism of physiologic MR in young normal subjects using transthoracic echocardiography.

METHODS

The study population consisted of 48 young normal subjects (mean 21 +/- 5 years) with MR (physiologic MR group), 40 age-matched young normal subjects (mean 20 +/- 5 years) without MR (control group), 45 patients (mean 41 +/- 15 years) with mitral valve prolapse with MR (MVP group), and 27 patients (mean 59 +/- 13 years) with ruptured chordae tendineae (rupture group).

RESULTS

Men were predominant in the rupture group, whereas there were no significant gender differences in the other three groups. Left ventricular end-diastolic dimension and left atrial systolic dimension were slightly smaller in the physiologic MR group than in the control group, but were significantly smaller than those in the MVP and rupture groups. The ratio of the maximum anteroposterior diameter to the maximum transverse diameter on chest radiography and the ratio of the short- to long-axis diameter of the left ventricular cavity at end diastole, determined from two-dimensional short-axis echocardiogram, were significantly lower in the physiologic MR group than in the other three groups. Mitral regurgitation occurred more frequently at the posteromedial commissural site in the physiologic MR and MVP groups, whereas there was no preference for location in the rupture group. Early systolic MR was often observed in the physiologic MR group, whereas pansystolic MR was common in the MVP and rupture groups.

CONCLUSION

As a causal mechanism for physiologic MR detected in young normal subjects, "flattening" of the thorax during growth may cause morphologic abnormalities of the left atrial and ventricular cavities, resulting in spatial imbalance of the mitral complex and resulting in malcoaptation of the valve.