Obstruction is associated with perineural invasion in T3/T4 colon cancer

AIM

Perineural invasion (PNI) is a risk factor for recurrence and metastasis and consequently leads to decreased survival in patients with various malignancies. Recent studies showed that stent placement in obstructive colon cancer increases the frequency of PNI. We hypothesized that mechanical stress including obstruction itself may be associated with PNI.

METHOD

We retrospectively reviewed 496 patients with pathological T3 or T4 colon cancer who did not receive preoperative treatment. Data were collected from medical charts and pathological findings. The relationships between PNI and other clinicopathological factors were analysed using univariate and multivariate analyses.

RESULTS

PNI was observed in 239 (48%) patients. Obstruction was markedly more frequent in PNI-positive cancer (39%) than in PNI-negative cancer (24%, P = 0.0003). Multivariate analyses identified obstruction as one of the significant factors associated with PNI (OR 1.68, P = 0.028). Moreover, in 414 patients without distant metastasis who underwent complete resection, PNI was an independent factor associated with poor recurrence-free survival (hazard ratio 2.35, P = 0.003). The coexistence of PNI and obstruction resulted in greater decreases in recurrence-free survival than PNI-negative and/or non-obstructive cases.

CONCLUSION

Our results suggest that obstruction is associated with PNI and consequently contributes to an increased postoperative recurrence in colon cancer.

Evidence for solitonic spin excitations from a charge-lattice-coupled ferroelectric order

Topological defects have been explored in different fields ranging from condensed matter physics and particle physics to cosmology. In condensed matter, strong coupling between charge, spin, and lattice degrees of freedom brings about emergent excitations with topological characteristics at low energies. One-dimensional (1D) systems with degenerate dimerization patterns are typical stages for the generation of topological defects, dubbed "solitons"; for instance, charged solitons are responsible for high electrical conductivity in doped trans-polyacetylene. Here, we provide evidence based on a nuclear magnetic resonance (NMR) study for mobile spin solitons deconfined from a strongly charge-lattice-coupled spin-singlet ferroelectric order in a quasi-1D organic charge-transfer complex. The NMR spectral shift and relaxation rate associated with static and dynamic spin susceptibilities indicate that the ferroelectric order is violated by dilute solitonic spin excitations, which were further demonstrated to move diffusively by the frequency dependence of the relaxation rate. The traveling solitons revealed here may promise the emergence of anomalous electrical and thermal transport.

Evaluation of the vascular anatomy of the left-sided colon focused on the accessory middle colic artery: a single-centre study of 734 patients

AIM

Surgery for colorectal cancer located in the splenic flexure is difficult to perform because of the complex anatomy. Recently, in addition to the middle colic artery and left colic artery (LCA), the accessory middle colic artery (AMCA) has been recognized as a feeding artery for the left-sided colon. This study aimed to evaluate the vascular anatomy of the splenic flexure focusing on the AMCA in a large number of patients.

METHOD

A total of 734 patients who underwent CT before surgery for colorectal cancer were enrolled. We retrospectively evaluated the vascular anatomy using both two- and three-dimensional CT angiography.

RESULTS

The AMCA existed in 36.4% of the cases (n = 267). In many cases, it originated from the superior mesenteric artery (n = 228, 85.4%). The AMCA had a common trunk with the transverse pancreatic artery in 54 patients (20.2%). The frequency of the presence of the AMCA was associated with the branching pattern of the LCA, and was more frequent when the LCA was absent (P < 0.001).

CONCLUSION

The presence of the AMCA is not rare and the AMCA has some branching patterns; therefore, recognizing it preoperatively and intra-operatively is important, being especially careful when the LCA is absent.

Cryopreservation of in vitro Shoot Tips of Ulluco (Ullucus tuberosus Cal.) Using D Cryo-Plate Method

　　BACKGROUND: Maintenance of in vitro collections of ulluco (Ullucus tuberosus Cal.) is cumbersome and costly in an ex-situ genebank. An alternative method for long term preservation which is safe and cost-effective is required.

OBJECTIVE

To apply a novel cryopreservation procedure using the cryo-plate system to improve the long-term conservation of ulluco.

MATERIALS AND METHODS

Initially V and D cryo-plate methods were tested, subsequently the D cryo-plate method was selected for ulluco cryopreservation. The D cryo-plate procedures were optimized for post-LN regrowth procedures including cold-hardening, sucrose addition in alginate gel, and duration of LS treatment. Optimized procedures were tested with 11 ulluco lines.

RESULTS

Shoot tips were isolated from cold-hardened shoots for 3-4 weeks at 5 degree C were excised to 1.0-1.5 mm long and 0.5 mm wide and precultured for 16h at 25 degree C on MS with 0.3 M sucrose. The shoot tips were attached on the cryo-plates by alginate gel with 0.4M sucrose. The cryo-plates with attached shoot tips were treated with 2.0 M glycerol and 1.0 M sucrose solution for 90 min at 25 degree C and dehydrated on filter paper in a Petri dish by air current flow at 25 degree C for 45 min before direct immersion in LN. This optimized procedure was applied to shoot tips of 11 ulluco lines, resulting regrowth ranging from 73 % to 97 %, with an average of 90 % post-LN regrowth.

CONCLUSION

D cryo-plate is a practical and simple procedure for cryo-storage of in vitro grown ulluco shoot tips in an ex situ genebank.