Caco-2 Cell Conditions Enabling Studies of Drug Absorption from Digestible Lipid-Based Formulations

Purpose

To identify conditions allowing the use of cell-based models for studies of drug absorption during in vitro lipolysis of lipid-based formulations (LBFs).

Methods

Caco-2 was selected as the cell-based model system. Monolayer integrity was evaluated by measuring mannitol permeability after incubating Caco-2 cells in the presence of components available during lipolysis. Pure excipients and formulations representing the lipid formulation classification system (LFCS) were evaluated before and after digestion. Porcine mucin was evaluated for its capacity to protect the cell monolayer.

Results

Most undigested formulations were compatible with the cells (II-LC, IIIB-LC, and IV) although some needed mucin to protect against damaging effects (II-MC, IIIB-MC, I-LC, and IIIA-LC). The pancreatic extract commonly used in digestion studies was incompatible with the cells but the Caco-2 monolayers could withstand immobilized recombinant lipase. Upon digestion, long chain formulations caused more damage to Caco-2 cells than their undigested counterparts whereas medium chain formulations showed better tolerability after digestion.

Conclusions

Most LBFs and components thereof (undigested and digested) are compatible with Caco-2 cells. Pancreatic enzyme is not tolerated by the cells but immobilized lipase can be used in combination with the cell monolayer. Mucin is beneficial for critical formulations and digestion products.

     

Genetic association signal near NTN4 in Tourette syndrome

Tourette syndrome (TS) is a neurodevelopmental disorder with a complex genetic etiology. Through an international collaboration, we genotyped 42 single nucleotide polymorphisms (p < 10⁻³) from the recent TS genomewide association study (GWAS) in 609 independent cases and 610 ancestry‐matched controls. Only rs2060546 on chromosome 12q22 (p = 3.3 × 10⁻⁴) remained significant after Bonferroni correction. Meta‐analysis with the original GWAS yielded the strongest association to date (p = 5.8 × 10⁻⁷). Although its functional significance is unclear, rs2060546 lies closest to NTN4, an axon guidance molecule expressed in developing striatum. Risk score analysis significantly predicted case–control status (p = 0.042), suggesting that many of these variants are true TS risk alleles. Ann Neurol 2014;76:310–315     

Factors Predicting Long-Term Survival Following Pancreatic Resection for Ductal Adenocarcinoma of the Pancreas: 40 Years of Experience

Background

Long-term survival after resection for pancreas carcinoma has rarely been reported. Factors influencing long-term survival are still under debate. The aim of this study was to define predictors for long-term survival.

Methods

Between 1972 and 2004, a total of 415 patients underwent resection. Data were collected in a prospective data base. Data of 360 patients were available for further analysis in 2011. All specimens of long-term survivors were histologically reviewed.

Results

Long-term survivors (n?=?69) had a median survival of 91 months. Pathological re-evaluation of all specimens re-confirmed the diagnosis. Predictive factors for long-term survival in univariate analysis were no preoperative biliary stent, low CA 19-9 level, lack of blood transfusion, R0 resection, tumour diameter, and -grading, absence of lymph node or distant metastases, lymphangiosis, and perineural infiltration. Adjuvant chemotherapy showed a significant influence on overall survival but not on long-term survival. In multivariate analysis, lymph node ratio and volume of blood transfusion were predictors of long-term survival.

Conclusion

Nearly 20 % of patients with pancreas carcinoma who undergo surgical resection have a chance of long-term survival. Survival beyond 5 years is predicted by clinical and tumour-specific factors. Adjuvant chemotherapy might prolong overall survival but is, according to these results, unable to contribute to long-term survival. There is still a risk of recurrence after a 5- or even a 12-year mark. Survival beyond 5 or even 12 years, therefore, does not assure cure.