Sensilla on antennae and mouthparts of adult spruce bark beetle Ips typographus (Coleoptera: Curculionidae).

The spruce bark beetle, Ips typographus, is an invasive forest pest that occurs across Eurasia. To further understand the mechanism of insect-host chemical communication and the feeding choices of adult I. typographus, we examined the sensilla on the antennae and mouthparts of I. typographus using scanning electron microscopy. No sexual dimorphism in sensilla type or distribution was observed. Ten subtypes of antennal sensilla were identified: sensilla trichodea Types I-III (TR1 , TR2 , and TR3 ); sensilla chaetica Types I and II (CH1 and CH2 ); sensilla basiconica Types I-III (BA1 , BA2 , and BA3 ); sensilla coeloconica (CO); and Böhm sensilla (BS). BA2 were the most abundant among the antennal sensilla in both sexes. Thirteen mouthpart sensilla subtypes were observed: sensilla trichodea Types I-IV (TR1 , TR2 , TR3 , and TR4 ); sensilla chaetica Types I-III (CH1 , CH2 , and CH3 ); sensilla digitiformia (DI); sensilla basiconica Types I-II (BA1 and BA2 ); and sensilla styloconica Types I-III (ST1 , ST2 , and ST3 ). Among these, TR4 were the most abundant in both sexes. The apex of each maxillary and labial palp carried the same sensilla (BA2 , ST1 , ST2 , and ST3 ), although the apex of the maxillary palp contained more total sensilla. The functional roles of each sensilla type are discussed based on their external structure and distribution. The results provide a theoretical basis for further studies on the olfactory and feeding behaviors and electrophysiology of adult I. typographus.

SEM analysis of sensilla on the mouthparts and antennae of Asian larch bark beetle Ips subelongatus.

The Asian larch bark beetle, Ips subelongatus, is a severe pest of larches in Northeastern China. The gustatory and olfactory systems of I. subelongatus play important roles in host location, mating, and feeding. In this study, we examined the types, distributions, and abundances of various sensilla associated with the mouthparts and antennae of I. subelongatus using scanning electron microscopy (SEM). On the mouthparts, five types of sensilla are present: sensilla trichodea (S.t.1-3), sensilla chaetica (S.c.1-3), sensilla basiconica (S.b.1-2), sensilla twig basiconica (S.tb.1-3), and sensilla placodea (S.p). S.t.3 are the most abundant sensilla subtype on the mouthparts in both sexes, while S.b.1 are the least abundant. Most sensilla on the mouthparts are located on the maxillae and labium, and the apex of each maxillary and labial palp carry the same sensilla subtypes (S.b.2 and S.tb.1-3). However, the total number of sensilla on the apex of each maxillary palp is higher than that on the labial palp. On the antennae, five types of sensilla are present: sensilla trichodea (S.t.1-3), sensilla chaetica (S.c.1-2), sensilla basiconica (S.b.1-3), Böhm bristles (B.b), and sensilla coeloconica (S.co). Antennal sensilla are mostly situated on the anterior surface of the antennal club, particularly on the two dense sensory bands. S.b.1 are the most abundant sensilla subtype on the antennae in both sexes, while S.t.1 are the least abundant. No sexual dimorphism in sensilla type or distribution on the mouthparts or antennae is observed between the sexes of I. subelongatus. However, S.t.3 (on mouthparts) and S.c.1 (on antennae) were significantly more abundant in males than in females, while more S.t.1 (on mouthparts) were observed in females than in males. Finally, the putative functions of each kind of sensilla with respect to their fine structures, distributions, and abundances on the mouthparts and antennae are discussed.

IGFBP7 plays a potential tumor suppressor role against colorectal carcinogenesis with its expression associated with DNA hypomethylation of exon 1.

Insulin-like growth factor binding-protein-7 (IGFBP7) was obtained from our previous colonic adenocarcinoma (CRC) and normal mucosa suppression subtraction hybridization (SSH) cDNA libraries. By RT-PCR and immunohistochemistry, we found that IGFBP7 was overexpressed in CRC tissue compared to normal tissue. However, our in vitro experiments performed in 10 CRC cell lines showed that IGFBP7 expressed only in SW480 and Caco2 cell lines, which implied an underlying reversible regulatory mechanism. Using methylation-specific PCR (MSP) and bisulfite sodium PCR (BSP), we found that its expression was associated with DNA hypomethylation of exon1. This was further supported by the in vitro study which showed restored IGFBP7 expression after demethylation agent 5-aza-2'-deoxycytidine treatment. Correlation analysis between IGFBP7 expression and prognosis indicated that overexpression of IGFBP7 in CRC tissue correlated with favourable survival. Investigation of the functional role of IGFBP7 through transfection studies showed that IGFBP7 protein could inhibit growth rate, decrease colony formation activity, and induce apoptosis in RKO and SW620 cells, suggesting it a potential tumor suppressor protein in colorectal carcinogenesis. In conclusion, our study clearly demonstrated that IGFBP7 plays a potential tumor suppressor role against colorectal carcinogenesis and its expression is associated with DNA hypomethylation of exon 1.

[Influence of clinical and pathomorphological parameters on prognosis in colon carcinoma and rectal carcinoma].

OBJECTIVE: To investigate the effects of clinical and pathomorphological parameters on the prognosis of colon carcinoma and rectal carcinoma. METHODS: Univariate and multivariate COX proportional hazard models were used to study the effects of the clinical and pathomorphological factors on the prognosis in 101 cases of colon carcinoma, 219 of rectal carcinoma and 137 of rectal carcinoma under curative resections. RESULT: By using univariate analysis, we identified that lymph node metastasis and distant metastasis were the common prognostic factors for both colon carcinoma and rectal carcinoma. Smoking, deep infiltration, chemotherapy and serum albumin concentration were the uncertain prognostic factors for colon carcinoma. Signet-ring cell carcinoma, larger tumor size (>6 cm), deep infiltration, lack of radical surgery, and advanced TNM stage were the exclusive adverse prognostic factors for rectal carcinoma. Further studies showed that the adverse prognostic factors for the rectal carcinoma under curative resection included deep infiltration, lymph node metastasis, vessel invasion, less of peritumoral lymphocyte infiltration, lack of Crohn's like reactivity, high level of tumor budding, advanced TNM stage and positive urine glucose. By using multivariate analysis based on a COX proportional hazard model, it was identified that smoking, lymph node metastasis and serum albumin concentration were independent prognostic factors for colon carcinoma; advanced TNM stage, distant metastasis and palliative surgery for rectal carcinoma; and vessel invasion, lymph node metastasis and urine glucose for rectal carcinoma under curative resections. CONCLUSION: The various clinical and pathomorphological parameters show different prognostic value for colon carcinoma, rectal carcinoma and rectal carcinoma under curative resections.

[Study on independent factors on the prognosis of colorectal carcinoma: TNM stage, tumor budding, perineural invasion, peritumoral-lymphocytic infiltration and urine glucose].

OBJECTIVE: To study the influence of clinical and pathological-morphological parameters on the prognosis of colorectal carcinoma. METHODS: Univariate and multivariate Cox proportional hazard model were used to study the influence of clinical and pathological-morphological factors on the prognosis in 226 colorectal carcinoma cases. RESULTS: Using univariate analysis, data showed that the factors significantly related to disease prognosis would include: the depth of direct spread, vessel invasion, perineural invasion, tumor budding, peritumoral-lymphocytic infiltration, Crohn-like reaction, number of positive lymph nodes, distant metastasis, TNM stage and urine glucose. Multivariate Cox proportional hazard model showed that six factors were identified to be associated with higher relative-risk (RR), including: older age, advanced TNM stage, more severe budding, perineural invasion, less peritumoral-lymphocytic infiltration and urine glucose. CONCLUSION: Age, TNM stage, tumor budding, perineural invasive, peritumoral-lymphocytic infiltration and urine glucose were independent predictors to the prognosis of colorectal carcinoma.