Association between corneal biomechanical properties and myopia in Chinese subjects

PURPOSE

To examine the relationship between corneal biomechanical properties and the degree of myopia.

METHODS

Chinese subjects (n=172, age: 11-65 years) were divided into diagnostic groups with non-myopia (spherical equivalence (SE)>-0.50 D), low (-3.00 ≤ SE ≤ -0.50 D), moderate (-6.00 ≤ SE < -3.00 D), and high myopia (SE<-6.00 D). Only the right eye of each subject was analyzed. Central corneal thickness (CCT) was measured by optical coherence tomography. An ocular response analyzer was used to measure corneal hysteresis (CH), corneal resistance factor (CRF), intraocular pressure (IOP), and corneal compensated IOP (IOPcc). Refraction was measured by both automated and subjective refractometry and expressed as SE.

RESULTS

CH was significantly lower in high myopia compared with both low and non-myopia (P ≤ 0.002). CCT was 1.5 times more correlated to CH variation compared with refraction. Similarly, CRF was four times more dependent on CCT than refraction. CH (P<0.001) or CRF (P=0.005) was positively correlated to refraction. Both IOP and IOPcc were negatively correlated to refraction (P<0.001), respectively.

CONCLUSIONS

CH decreases only in high myopia. Refraction is positively correlated to both CH and CRF but negatively correlated to both IOP and IOPcc. These results indicate that the mechanical strength in anterior segment of the eye is compromised in high myopia. In addition, high myopia may increase the risk of glaucoma.

Analysis of differential gene expression by bead-based fiber-optic array in nonfunctioning pituitary adenomas

Nonfunctioning pituitary adenomas (NFPAs) are relatively common, accounting for 30% of all pituitary adenomas; however, their pathogenesis remains enigmatic. To explore the possible pathogenesis of NFPAs, we used fiber-optic BeadArray to examine gene expression in 5 NFPAs compared with 3 normal pituitaries. 4 differentially expressed genes were chosen randomly for validation by reverse transcriptase-real time quantitative polymerase chain reaction (RT-qPCR). We then analyzed the differentially expressed gene profile with Kyoto Encyclopedia of Genes and Genomes (KEGG). The array analysis indentified significant increases in the expression of 1,402 genes and 383 expressed sequence tags (ESTs), and decreases in 1,697 genes and 113 ESTs in the NFPAs. Bioinformatic and pathway analysis showed that the genes HIGD1B, FAM5C, PMAIP1 and the pathway cell-cycle regulation may play an important role in tumorigenesis and progression of NFPAs. Our data suggest fiber-optic BeadArray combined with pathway analysis of differential gene expression profile appears to be a valid approach for investigating the pathogenesis of tumors.

Curcumin delivery by methoxy polyethylene glycol-poly(caprolactone) nanoparticles inhibits the growth of C6 glioma cells

As a potential anticancer agent, curcumin (Cum) has been reported for its chemopreventive and chemotherapeutic activity in a series of cancers through influencing cell cycle arrest, differentiation, apoptosis, etc. Therefore, the potential activity against various cancers of Cum raises the possibility of its application as a novel model drug in nanoparticle-based delivery systems. The current study reported a spherical core-shell structure curcumin-loaded nanoparticle (Cum-np) formed by amphilic methoxy polyethylene glycol-poly(caprolactone) (mPEG-PCL) block copolymers. Characterization tests indicated that Cum was incorporated into mPEG-PCL-based nanoparticles with high encapsulation efficiency due to its lipophilicity. The incorporated Cum could be released from Cum-np in a sustained manner. Cum was effectively transported into the cells by nanoparticles through endocytosis and localized around the nuclei in the cytoplasms. In vitro studies proved that the cytotoxicity of Cum-np would be pro-apoptosis effect against rat C6 glioma cell line in a dose-dependent manner. The present results suggest that Cum-np could be a potential useful chemotherapeutic formulation for malignant glioma therapy. Moreover, the development of traditional Chinese medicine with nanoscale drug formation warrants more intensive research for its clinical applications.

Evaluation of supporting role of a foldable capsular vitreous body with magnetic resonance imaging in the treatment of severe retinal detachment in human eyes

PURPOSE

To determine the supporting role of a novel foldable capsular vitreous body (FCVB) with magnetic resonance imaging (MRI) in the treatment of severe retinal detachment in human eyes.

METHODS

The study examined nine eyes of nine patients. Among the nine eyes, five had suffered penetrating injuries while four had suffered contusions of the eyeball involving large defects of the retina or choroids. A standard three-port pars plana vitrectomy was performed, FCVB was triple-folded and sent into the vitreous cavity; balanced salt solution (BSS) was injected into the capsule to support the retina. Three cardinal axes of nine eyes were examined using MRI at baseline and at the 3-month follow up.

RESULTS

MRI revealed that the signal intensity of the FCVB was similar to the normal vitreous body, with low-signal intensity on T1-weighted image and high-signal intensity on T2-weighted image. In three pre-operative silicone oil- or heavy silicone oil-filled eyes, FCVBs were not fully inflated, and eyeball deformation was observed in one eye. Shifts of three cardinal axes of three eyes (horizontal, anteroposterior, and vertical) according to MRI, were -4.33, -4.67, and -2.67 mm. In the remaining six eyes, FCVBs were well distributed in the vitreous cavity and evenly supported the retina; the cardinal axes of the eyes were similar to pre-operation. Shifts of three cardinal axes of six eyes were -0.34, -0.34, and -0.34 mm. In a total of nine eyes, shifts of three cardinal axes were -1.67, -1.77, and -1.11 mm. Statistically significant difference showed only between the horizontal axis of nine eyes pre-operatively and post-operatively (P1=0.041, P2=0.058, P3=0.123).

CONCLUSION

This study demonstrated the effectiveness of MRI to monitor the supporting role of an FCVB in the treatment of severe retinal detachment in human eyes.

Association of PTEN loss and local recurrence in stage II-III colon cancer

399

Background: Activation of the PI3K/Akt signaling pathway by PIK3CA mutations has been associated with increased risk for local recurrence (LR) in rectal cancer patients (pts). We hypothesized that loss of expression of PTEN, a tumor suppressor gene and negative regulator of the PI3K/Akt pathway, may also be associated with increased rates of LR in colon cancer.

Methods: We studied 156 pts with stage II-III colon cancer resected from 1/1990 to 12/2002, including pathology review, PTEN immunohistochemistry, microsatellite instability (MSI) status, 18q loss of heterozygosity (LOH) status and clinical follow-up. PTEN expression with a CLIA-compliant protocol (DAKO antibody) was determined in a tissue microarray with four cores from each tumor and with non-neoplastic mucosa. PTEN loss was defined as complete absence of expression in malignant epithelium with preserved expression of adjoining non-neoplastic tissue serving as a positive control. LR was defined as anastomotic or pericolic peritoneal disease.

Results: 83 M and 73 F pts with median age of 63 were included, with median follow-up of 7.6 yrs. PTEN loss was identified in 26 (16.7%) pts. There were no significant differences in age, sex, T stage, N stage, tumor differentiation, tumor site, lymphovascular invasion (LVI), mucinous component, MSI status or 18q LOH between the PTEN-lost and PTEN-intact groups. The overall survival, relapse-free survival, and distant metastases rate were similar. However, PTEN loss was associated with higher rates of LR (15.4% vs. 4.6%, p = 0.041), and the time to LR was shorter for pts with PTEN loss in their tumor than in PTEN-intact pts (HR 3.3, p = 0.049 by log-rank). LR was associated with LVI, R-sided tumor, 18qLOH, and PTEN loss in univariate analysis. In a multivariate analysis, PTEN loss was associated with a 10.6 fold increased risk of LR (95% CI: 1.7-64.8, p = 0.011).

Conclusions: PTEN loss is associated with a higher rate of and shorter time to LR after resection of colon cancer. This result is consistent with a prior report on the role of PI3K pathway in LR of rectal cancer and suggests that PTEN alteration is a prognostic indicator and that the PI3K/Akt pathway is a potential therapeutic target for these pts.

No significant financial relationships to disclose.

Effect of capsaicin on potassium conductance and electromotility of the guinea pig outer hair cell

Capsaicin, the classic activator of TRPV-1 channels in primary sensory neurons, evokes nociception. Interestingly, auditory reception is also modulated by this chemical, possibly by direct actions on outer hair cells (OHCs). Surprisingly, we find two novel actions of capsaicin unrelated to TRPV-1 channels, which likely contribute to its auditory effects in vivo. First, capsaicin is a potent blocker of OHC K conductances (I(K) and I(K,n)). Second, capsaicin substantially alters OHC nonlinear capacitance, the signature of electromotility - a basis of cochlear amplification. These new findings of capsaicin have ramifications for our understanding of the pharmacological properties of OHC I(K), I(K,n) and electromotility and for interpretation of capsaicin pharmacological actions.

Comparison of ampullary adenocarcinomas and duodenal adenocarcinomas with regard to clinical outcomes and responsiveness to fluoropyrimidine-based chemotherapy

204

Background: Though adenocarcinomas of the ampulla of Vater are classified as biliary cancers, the epithelium of origin and treatment approach for these rare tumors remains controversial. Gene expression profiling of periampullary carcinomas (GI ASCO 2011) suggest that ampullary carcinomas are more akin to duodenal than pancreaticobiliary carcinomas.

Methods: Review of a M. D. Anderson Cancer Center (MDACC) periampullary surgical database from 1/1990 to 3/2010 identified 670 pancreatic, 41 extrahepatic biliary, 63 duodenal, and 131 ampullary adenocarcinomas resected at MDACC. Review of the MDACC tumor registry from 5/1990 to 1/2009 identified 240 stage I-III surgically resected ampullary adenocarcinomas seen at MDACC. 46 patients met the following inclusion criteria: MDACC confirmed pathology, distant metastatic relapse, and ≥1 cycle of either gemcitabine or fluoropyrimidine (5-FU) based first-line chemotherapy with follow-up imaging evaluation.

Results: 5-year OS of patients with ampullary cancer did not differ from duodenal cancer (62% vs. 66%, p=0.19) but was significantly different from biliary (24%, p<0.001), and pancreatic cancer (17%, p<0.001). When ampullary (n=131) and duodenal (n=63) cases were stratified by T stage (T1/T2, T3/T4) or N stage (N0, N1) no statistically significant differences in OS were seen. First-line chemotherapy for metastatic ampullary carcinoma was 5-FU based in 27 patients (single agent 8, platinum 18, other 1) and gemcitabine based in 19 patients (single agent 7, platinum 8, other 4). Similar rates of prior adjuvant/neoadjvuant chemotherapy use (55% vs. 64%) and time to distant metastases (18 vs. 17m) were seen in the 5-FU and gemcitabine groups, respectively. 5-FU based chemotherapy was associated with an improved median TTP (9.1m v 4.8m, p=0.05) and trended to improve RR (44% v 21%, p=0.13) and median OS (16m vs. 12.7m, p=0.14).

Conclusions: OS of resected ampullary carcinomas is similar to duodenal carcinomas but not biliary or pancreatic carcinomas. Preliminary data suggest that metastatic ampullary carcinomas may benefit more from a fluoropyrimidine-based as opposed to gemcitabine-based chemotherapy.

[Table: see text]

Neoadjuvant therapy for adenocarcinomas of the duodenum and ampulla of Vater

279

Background: Adenocarcinomas of the ampulla of Vater and duodenum are both rare periampullary tumors with limited data regarding the use of neoadjuvant therapy. We sought to better define the role of neoadjuvant therapy as compared to adjuvant therapy in patients with high-risk disease.

Methods: Retrospective review of the M. D. Anderson Cancer Center (MDACC) tumor registry from 5/1990 to 1/2009 identified 66 cases of ampullary (26 neoadjuvant, 40 adjuvant) and 41 cases of duodenal adenocarcinoma (18 neoadjuvant, 23 adjuvant). Only patients who received adjuvant or neoadjuvant therapy and underwent surgical resection at MDACC where included. High-risk factors were defined as T3 or T4, poor differentiation, or lymph node involvement. Relapse-free survival (RFS) and overall survival (OS) were calculated from the start of surgical resection.

Results: Median age was 61 yrs (range 30-82) and 39% were female. Neoadjuvant (n=44) and adjuvant therapy (n=63) consisted of 5-FU chemoradiation in 93% and 65%, systemic 5-FU based chemotherapy only in 5% and 24%, and gemcitabine or irinotecan based therapy in 2% and 11%, respectively. Pathological high-risk factors were seen in 77% and 95% of neoadjuvant and adjuvant patients, respectively. Indications for neoadjuvant therapy were high risk disease (70%), poor surgical candidate (16%), and concern for possible metastatic disease (14%). In the neoadjuvant group T and N downstaging were observed in 25% and 32% of patients, respectively; 3 patients (7%) had a pathological complete response. Neoadjuvant as compared to adjuvant therapy had similar 5-year OS (66% vs. 59%, p =0.8) and 5-year RFS (54% vs. 59%, p=0.4). Variables significant (p <0.05) in the multivariate analysis for OS were age >60 yrs, lymph node involvement, and margin positivity; and for RFS were lymph node involvement and margin positivity. Neither tumor type (duodenal vs. ampullary; OS HR: 1.6, p =0.2; RFS HR: 0.9, p=0.8) nor treatment type (neoadjuvant vs. adjuvant; OS HR: 1.2, p =0.6; RFS HR: 1.1, p=0.7) were significant for OS or RFS in the multivariate model.

Conclusions: Neoadjuvant therapy appears to be a viable approach for high-risk duodenal and ampullary adenocarcinomas. Further investigation of this treatment approach is needed.

[Table: see text]

Relative impact of chemotherapy with or without bevacizumab on cytokines and angiogenic factors (CAFs) in metastatic colorectal cancer

401

Background: CAFs were previously shown to be modulated in patients (pts) with metastatic colorectal cancer (mCRC) after bevacizumab-containing chemotherapy. Validation of these prior findings is warranted. In addition, the relative impact of bevacizumab and the cytotoxic chemotherapy components on CAFs has not been previously described.

Methods: Plasma samples from 403 mCRC pts were obtained prior to any chemotherapy (Group A) or after progression on a regimen without or with bevacizumab (Group B and C, respectively) between 2002 and 2008. Samples were matched for number of metastatic disease sites (Groups A, B, C) and for prior chemotherapy duration, and time from last chemotherapy dose to sample collection (Groups B, C). Levels of 48 CAFs were measured by suspension bead multiplex assays (BioRad and EMD). Comparisons of Groups A v C (n=169 pairs) and Groups B v C (n=65 pairs) were by the two-sided, nonparametric Wilcoxon paired test, with p<0.05 significance for confirmation of previous CAF results.

Results: Prior chemotherapy duration (6.5mo, 6.7mo), and time from last chemotherapy dose to sample collection (1.3mo, 1.2 mo) were similar for Groups B and C, respectively. Results were available for 80% of the samples. Compared to Group A, Group B had reductions in multiple CAFs, including IL-8 (-38%, p<0.0001) and PDGF (-62%, p<0.0001). Commensurate with prior results, PlGF, Eotaxin and TRAIL were increased in Group C by 30% (p<0.0001), 23% (p=0.024) and 19% (p=0.008) respectively. Most CAF changes were attributable to chemotherapy alone. However, PlGF (-31%, p<0.0001) and TRAIL (+26%, p=0.037) significantly differed in Groups B v C. In group C compared to A, multiple changes were seen in the EGFR-axis including decreases in EGF (-52%, p=0.032), epiregulin (-25%, p=0.0023), and HB-EGF (-40%, p<0.0001) as well as an increase in sEGFR (+10%, p=0.004).

Conclusions: Most changes in CAFs after treatment with bevacizumab-containing chemotherapy appear to be due to chemotherapy alone and not attributable to anti-VEGF therapy, with several notable exceptions. Chemotherapy-induced changes in the EGFR-axis have not previously been described in mCRC and warrant further investigation.

[Table: see text]

Epithelial transport and deamidation of gliadin peptides: a role for coeliac disease patient immunoglobulin A

In coeliac disease, the intake of dietary gluten induces small-bowel mucosal damage and the production of immunoglobulin (Ig)A class autoantibodies against transglutaminase 2 (TG2). We examined the effect of coeliac patient IgA on the apical-to-basal passage of gluten-derived gliadin peptides p31-43 and p57-68 in intestinal epithelial cells. We demonstrate that coeliac IgA enhances the passage of gliadin peptides, which could be abolished by inhibition of TG2 enzymatic activity. Moreover, we also found that both the apical and the basal cell culture media containing the immunogenic gliadin peptides were able to induce the proliferation of deamidation-dependent coeliac patient-derived T cells even in the absence of exogenous TG2. Our results suggest that coeliac patient IgA could play a role in the transepithelial passage of gliadin peptides, a process during which they might be deamidated.

Construction of a novel expression cassette for increasing transgene expression in vivo in endothelial cells of large blood vessels

The success of gene therapy hinges on achievement of adequate transgene expression. To ensure high transgene expression, many gene-therapy vectors include highly active virus-derived transcriptional elements. Other vectors include tissue-specific eukaryotic transcriptional elements, intended to limit transgene expression to specific cell types, avoid toxicity and prevent immune responses. Unfortunately, tissue specificity is often accompanied by lower transgene expression. Here, we use eukaryotic (murine) transcriptional elements and a virus-derived posttranscriptional element to build cassettes designed to express a potentially therapeutic gene (interleukin (IL)-10) in large-vessel endothelial cells (ECs) at levels as high as obtained with the cytomegalovirus (CMV) immediate early promoter, while retaining EC specificity. The cassettes were tested by incorporation into helper-dependent adenoviral vectors, and transduction into bovine aortic EC in vitro and rabbit carotid EC in vivo. The murine endothelin-1 promoter showed EC specificity, but expressed only 3% as much IL-10 mRNA as CMV. Inclusion of precisely four copies of an EC-specific enhancer and a posttranscriptional regulatory element increased IL-10 expression to a level at or above the CMV promoter in vivo, while retaining--and possibly enhancing--EC specificity, as measured in vitro. The cassette reported here will likely be useful for maximizing transgene expression in large-vessel EC, while minimizing systemic effects.

An investigation of cancer incidence in a First Nations community in Alberta, Canada, 1995–2006

Objective

To determine colorectal and overall cancer incidence as part of a three-pronged investigation in response to the concerns of a First Nations community in Alberta, Canada, located close to sulfur-rich natural gas installations, and to determine whether the incidence of cancers observed in this reserve was higher than expected.

Methods

A population dataset with information identifying First Nations status and band affiliation was linked to the Alberta Cancer Registry to determine cancer incidence cases between 1995 and 2006 for on- and off-reserve study populations. Using indirect standardized incidence ratios, observed cancer incidence cases for the study populations were compared with cases expected based on three separate reference populations.

Results

Observed colorectal and overall cancer incidence cases within the First Nations community were not higher than expected. Cervical cancer incidence cases, however, were higher than expected for on- and off-reserve populations; public health measures designed to address this risk have been implemented and on-going surveillance of cancer incidence in the community will be maintained.

An investigation of cancer incidence in a First Nations community in Alberta, Canada, 1995-2006

OBJECTIVE

To determine colorectal and overall cancer incidence as part of a three-pronged investigation in response to the concerns of a First Nations community in Alberta, Canada, located close to sulfur-rich natural gas installations, and to determine whether the incidence of cancers observed in this reserve was higher than expected.

METHODS

A population dataset with information identifying First Nations status and band affiliation was linked to the Alberta Cancer Registry to determine cancer incidence cases between 1995 and 2006 for on- and off-reserve study populations. Using indirect standardized incidence ratios, observed cancer incidence cases for the study populations were compared with cases expected based on three separate reference populations.

RESULTS

Observed colorectal and overall cancer incidence cases within the First Nations community were not higher than expected. Cervical cancer incidence cases, however, were higher than expected for on- and off-reserve populations; public health measures designed to address this risk have been implemented and on-going surveillance of cancer incidence in the community will be maintained.