In vitro neuroprotective action of recombinant rat erythropoietin produced by astrocyte cell lines and comparative studies with erythropoietin produced by Chinese hamster ovary cells

In the central nervous system, astrocytes produce erythropoietin (Epo) and neurons express its receptor. To examine whether or not the brain Epo protects the in vitro cultured neurons from glutamate-induced cell death, we established rat astrocyte cell lines containing the plasmid for production of recombinant rat Epo. Epo partially purified from the culture medium showed a neuroprotective effect similar to that of rat Epo produced by Chinese hamster ovary (CHO) cells. Comparison was made in some other properties between Epo produced by these astrocyte cell lines and that by CHO cells. Digestion of Epo with glycosidases indicated that there was a little difference in glycosylation of Epo produced by two types of the cells.

Pheromonal cross-attraction in true bugs (Heteroptera): attraction of Piezodorus hybneri (Pentatomidae) to its pheromone versus the pheromone of Riptortus pedestris (Alydidae)

We investigated the attractiveness of a synthetic form of the pheromone of the soybean stink bug, Piezodorus hybneri (Gmelin), under field conditions, and compared it with that of (E)-2-hexenyl (E)-2-hexenoate, a pheromone component of a competitor, Riptortus pedestris (Fabricius). Many adult stink bugs were attracted to traps baited with 100 mg of the synthetic pheromone (1: 1: one mixture of β-sesquiphellandrene, (R)-15-hexadecanolide, and methyl (Z)-8-hexadecenoate), but few were attracted to 1 or 10 mg. More than twice as many females as males were attracted to this male-produced pheromone. None of the individual pheromone components (30 mg) attracted conspecifics. In summer (June-July), when field P. hybneri were not in diapause, (E)-2-hexenyl (E)-2-hexenoate was more attractive to P. hybneri than the synthetic pheromone. The sex ratio of the adults attracted to the synthetic pheromone was highly female-biased, yet almost equal numbers of both sexes were attracted to (E)-2-hexenyl (E)-2-hexenoate. Most females attracted to both attractants were mated and had mature ovaries. However, adults attracted to (E)-2-hexenyl (E)-2-hexenoate were likely to have less food in their stomach than those attracted to the synthetic pheromone. In late autumn (October-November), when the bugs were in reproductive diapause, both attractants attracted many sexually immature female and male adults that had well-developed fat body. The synthetic pheromone also attracted a large number of conspecific nymphs. These results suggest that P. hybneri pheromone and R. pedestris pheromone component, respectively, have different functions for P. hybneri. The male-produced pheromone system of P. hybneri seems to be sex-related but to have other roles.

Prognostic relevance of the lymph node ratio in surgical patients with extrahepatic cholangiocarcinoma

AIM

Few studies have investigated the influence of the lymph node ratio (LNR), the ratio of the number of lymph nodes harboring metastatic cancer to the total number of lymph nodes removed, on the outcome after surgery for extrahepatic cholangiocarcinoma. This study was conducted to examine the prognostic impact of LNR in patients undergoing resection for extrahepatic cholangiocarcinoma.

PATIENTS AND METHODS

We retrospectively analyzed a total of 60 consecutive patients who underwent resection for extrahepatic cholangiocarcinoma. We focused on the LNR, which was classified as 0 in 34 patients, between 0 and 0.2 in 13 patients, and greater than 0.2 in 13 patients.

RESULTS

The overall five-year survival rates for patients with LNRs of 0, 0 to 0.2, and ≥0.2 were 44%, 10%, and 0%, respectively (p = 0.023). LNR was an independent predictive factor for estimated survival by both univariate (p = 0.016) and multivariate (p = 0.022) analyses including LNR, the sites of the primary tumors, and surgical margin as the variables. There were no statistically significant differences between patients who had less than 12 lymph nodes removed and those who had 12 or more lymph nodes removed (p = 0.484).

CONCLUSION

LNR was a powerful, independent predictor of estimated survival in patients undergoing surgical resection for extrahepatic cholangiocarcinoma. LNR should be considered when stratifying patients for future clinical trials.