Prognostic significance of the metastatic lymph node ratio compared to the TNM classification in stage III gastric cancer

Background

We aimed to evaluate a comparative analysis of the prognostic value of the metastatic lymph node ratio (LNR) and pN (TNM) in stage III gastric cancer.

Patients and Methods

A total of 159 stage III gastric cancer patients with curative gastrectomy were retrospectively analyzed. Cutoff values for LNR were designated according to 25%, 50% and 75% percentiles, 0.07, 0.20 and 0.44 respectively. The LNR was divided into four groups as 0 > LNR1 ≤ 0.07; 0.07 > LNR2 ≤0.20; 0.20 > LNR3 ≤0.44; 0.44 > LNR4 ≤1.

Results

The mean age of the patients was 61.1 ± 11.3 years. Male predominance was apparent (73.6%). The 1-year overall survival and recurrence rates were 73.6% and 33.6%, respectively. The univariate cox regression analysis demonstrated age and LNR were the main variables that affected overall survival (OS) (p < 0.05). Harvested lymph nodes less than 16 did not affect OS (p = 0.255). The results of the multivariate cox regression analysis revealed that only LNR was an independent prognostic factor (P < 0.001), while pN was not (p > 0.05). Similar results, as with overall survival, could not be revealed clearly for disease free survival (DFS).

Conclusions

LNR was an independent significant prognostic factor and superior to pN staging in predicting OS but not for DFS in stage III gastric cancer patients. The high LNR levels in our research were found to be associated with poor survival rates. The percentile system we used to determine cutoff values may be considered as a reliable method. Similarly, LNR also provides a reliable prognostic parameter in future staging systems to help guide treatment algorithm plans.

The protective effects of Ginkgo biloba extract (EGb-761) on radiation-induced dermatitis: an experimental study

BACKGROUND

Irradiation of the skin induces production of free radicals, resulting in oxidative stress. EGb-761, an extract from the leaves of the Ginkgo biloba tree, has been reported to be an effective exogenous antioxidant based on its free-radical scavenger properties.

AIM

To investigate the protective effect of G. biloba extract (EGb-761) on radiation-induced dermatitis in rats.

METHODS

Forty male Wistar rats were divided equally into four groups: group 1 received sham radiotherapy (RT) without EGb-761, group 2 received sham RT with EGb-761, group 3 received RT without EGb-761, and group 4 received RT with EGb-761. Levels of malondialdehyde (MDA), nitric oxide (NOx) and glutathione (GSH) were measured. Dermatitis was assessed with a semiquantitative dermatitis item score. The intensity of staining and diffusion of expression for proliferating cellular nuclear antigen (PCNA) and transforming growth factor (TGF)-β3 were also evaluated.

RESULTS

The enhanced oxidative stress seen after RT was markedly diminished when EGb-761 was administered with RT; significantly lower mean MDA (P < 0.005) and higher mean GSH (P < 0.001) levels were seen in group 4 compared with group 3. Although there was a decrease in NOx levels, this was not significant. All (100%) of the animals in group 3 developed dermatitis, whereas only 13% of the animals in group 4 did so (P < 0.0001). There was a significant difference between group 1 and group 3 in PCNA and TGF-β3 staining (P < 0.05), whereas no difference was seen between groups 3 and 4; however, the intensity of staining and diffusion of expression were lower in group 4 than in group 3.

CONCLUSIONS

Prophylactic administration of EGb-761 seems to have a protective effect against radiation-induced dermatitis.

The study of biochemical and histopathological effects of spirulina in rats with TNBS-induced colitis

OBJECTIVES

To evaluate the beneficial effects of spirulina on the treatment of experimental colitis.

BACKGROUND

Spirulina, a planktonic blue green algae from oascillateriaceae family, has anti-inflammatory, antioxidant, antitumor, anti-viral, and antimicrobial effects, rendering it a natural drug of prophylactic and therapeutic properties. The effects of spirulina on colitis are not known.

METHODS

Wistar rats weighing 200-300 g were used. Experimental colitis was created during anesthesia using the trinitrobenzene sulfonic (TNBS) acid. The rats were randomly divided into the 3 groups. In the group 1 (sham; n = 8), saline was administered via oral gavage 7 days after 1 ml of rectal saline was administered. In the group 2 (experimental colitis + spirulina; n = 8), 2 g/kg spirulina was administered via oral gavage 7 days after the rectal 1 ml TNBS was administered. In group 3 (experimental colitis; n = 8), enema was administered via oral gavage 7 days after the rectal 1 ml TNBS was administered. Eight days after the instigation of TNBS colitis, the rats were sacrificed and blood and tissue samples were taken. Histopathologic and immunohistochemical evaluations were conducted, and malondialdehyde (MDA), advanced oxidation protein products (AOPP), catalase (CAT), total antioxidant status (TAS), and glutathione (GSH) levels were determined.

RESULTS

Inflammation on mucosa and submucosa, hemorrhage, necrosis, cellular infiltration and crypt abscess formation, immunoreactivity and tissue MDA levels were decreased in the experimental colitis + spirulina group when compared to the experimental colitis group (p < 0.05).

CONCLUSION

The results of the present study indicate the beneficial effects of spirulina on TNBS-induced inflammatory bowel disease (Tab. 6, Fig. 10, Ref. 40).

The effect of taurine on renal ischemia/reperfusion injury

Ischemia-reperfusion (I/R) injury is one of the most common causes of renal dysfunction. Taurine is an endogenous antioxidant and a membrane-stabilizing, intracellular, free beta-amino acid. It has been demonstrated to have protective effects against I/R injuries to tissues other than kidney. The aim of this study was to determine whether taurine has a beneficial role in renal I/R injury. Forty Wistar-Albino rats were allocated into four groups as follows: sham, taurine, I/R, and I/R+taurine. Taurine 7.5 mg/kg was given intra-peritoneally to rats in the groups taurine and I/R+taurine. Renal I/R was achieved by occluding the renal arteries bilaterally for 40 min, followed by 6 h of reperfusion. Immediately thereafter, blood was drawn and tissue samples were harvested to measure 1) serum levels of BUN and creatinine; 2) serum and/or tissue levels of malondialdehyde (MDA), glutathione (GSH), glucose 6-phosphate dehydrogenase (G-6PD), 6-phosphogluconate dehydrogenase (6-PGD) and glutathione reductase (GSH-red); 3) renal morphology; and 4) immunohistochemical staining for P-selectin. Taurine administration reduced I/R-induced increases in serum BUN and creatinine, and serum and tissue MDA levels (p<0.05). Additionally, taurine lessened the reductions in serum and tissue glutathione levels secondary to I/R (p<0.05). Taurine also attenuated histopathologic evidence of renal injury, and reduced I/R-induced P-selectin immunoreactivity (p<0.05). Overall, then, taurine administration appears to reduce the injurious effects of I/R on kidney.

Histological and magnetic resonance imaging alterations after irradiation of meniscus using Holmium:YAG laser

OBJECTIVE

The authors performed an experimental and a prospective clinical study to evaluate the histological and magnetic resonance imaging (MRI) alterations after irradiation of meniscus using holmium:YAG (Ho:YAG) laser VersaPulse Select 60 watts and InfraTome Delivery Systems 30 degrees Handpiece (spot size at fiber tip 0.4 mm; Coherent Medical, Palo Alto, CA).

BACKGROUND DATA

Recently, some authors reported a few cases with articular cartilage damage or paraarticular osteonecrosis following arthroscopic knee surgery in which the laser was used to assist in the treatment of meniscal pathology.

METHODS

Meniscus specimens in saline immersion were exposed to Ho:YAG laser irradiation. The laser wavelength was 2.1 microm and pulse duration was 250 microsec. Power settings were 1-1.5 joules per pulse and 10-15 Hz. Total laser energy used in these procedures was 2, 3.5, and 6 K joules. Eight patients with meniscal problems underwent arthroscopic partial meniscectomy using Ho:YAG laser. Total laser energy used for these surgeries was 1.5-2.5 K joules. MRI was performed preoperatively and at 6 months postoperatively.

RESULTS

At higher energy levels (more than 3 K joules), separation of the gap between the collagen fibers, and a three-dimensional dispersion in the striation were observed on electron microscopic evaluation of meniscus specimens. No patient had abnormal signals in MRI (a sign of articular cartilage damage or osteonecrosis) following arthroscopic laser surgery.

CONCLUSION

When higher energy level is required, conventional instruments should be preferred in the treatment of meniscal lesions. Laser should be reserved for the posteriorly located and smaller meniscal lesions.

Effect of 25-OH-vitamin D on fracture healing in elderly rats

To investigate the effect of 25-OH-vitamin D supplements (calcidiol) on fracture healing in the elderly, an experimental model with 15 18-month-old female Wistar rats was designed. An experimental fracture in the middle third of both femora of each rat was made. Then the rats were randomly assigned to two groups: one group was subcutaneously treated with 25-OH-vitamin D during all healing processes, and the other group (the control group) was not. After 5 weeks of healing, the animals were killed and both femora were extracted. Blood samples were collected before fracture and at death to determine the levels of 25-OH-vitamin D. All bones that were extracted were subjected to a torsion test to assess healing; a significantly greater maximum shear force before failure was supported in the treated group (p < 0.01). Moreover, a positive correlation (p < 0.01; r=0.55) was found between blood levels of 25-OH-vitamin D at death and the mechanical strength of the callus. Thus, the administration of 25-OH-vitamin D after the experimental fracture significantly improved the mechanical strength of the fractured bone. If similar results are found in the human, then treatment with 25-OH-vitamin D after the occurrence of a fracture would be a good way to improve fracture healing in the elderly.