Intestinal microbiota enhances pancreatic carcinogenesis in preclinical models.

Pancreatic ductal adenocarcinoma (PDAC) is the third leading cause of cancer death in the United States yet data are scant regarding host factors influencing pancreatic carcinogenesis. Increasing evidence support the role of the host microbiota in carcinogenesis but its role in PDAC is not well established. Herein, we report that antibiotic-mediated microbial depletion of KrasG12D/PTENlox/+ mice showed a decreased proportion of poorly differentiated tumors compared to microbiota-intact KrasG12D/PTENlox/+ mice. Subsequent 16S rRNA PCR showed that ~50% of KrasG12D/PTENlox/+ mice with PDAC harbored intrapancreatic bacteria. To determine if a similar observation in humans correlates with presence of PDAC, benign and malignant human pancreatic surgical specimens demonstrated a microbiota by 16S bacterial sequencing and culture confirmation. However, the microbial composition did not differentiate PDAC from non-PDAC tissue. Furthermore, murine pancreas did not naturally acquire a pancreatic microbiota, as germ-free mice transferred to specific pathogen-free housing failed to acquire intrapancreatic bacteria over time, which was not augmented by a murine model of colitis. Finally, antibiotic-mediated microbial depletion of Nod-SCID mice, compared to microbiota-intact, showed increased time to PDAC xenograft formation, smaller tumors, and attenuated growth. Interestingly, both xenograft cohorts were devoid of intratumoral bacteria by 16S rRNA PCR, suggesting that intrapancreatic/intratumoral microbiota is not the sole driver of PDAC acceleration. Xenografts from microbiota-intact mice demonstrated innate immune suppression by immunohistochemistry and differential regulation of oncogenic pathways as determined by RNA sequencing. Our work supports a long-distance role of the intestinal microbiota on PDAC progression and opens new research avenues regarding pancreatic carcinogenesis.

Challenges Faced by Latino Caregivers in Transportation of Children with Medical Complexity.

BACKGROUND Transportation challenges affect access to health care. Our objective was to describe transportation challenges faced by Latino children with medical complexity and identify strategies that could address these challenges.METHODS This is a qualitative study. Seventy Latino children with medical complexity who were enrolled in a complex care program of a tertiary care children's hospital were followed for a median duration of 18 months. Qualitative data were care coordination notes for each child obtained from care coordinators' encounter logs and reported experiences. Using thematic content analysis and an iterative process, we identified recurrent themes related to transportation challenges.RESULTS Caregivers of Latino children with medical complexity face many challenges transporting their children to medical appointments. These include lack of vehicle, inability to drive, lack of driver's license due to immigration status, and lack of resources to maintain a vehicle. As a result, Latino children with medical complexity often need non-emergency medical transportation, but caregivers find these systems difficult to use, in part because of language difficulties. Thus, they rely on care coordinators to access non-emergency medical transportation. Transportation problems can lead to missed medical appointments for the child and lost work for the caregiver. We identified interrelated factors that contributed to transportation issues for Latino children with medical complexity and potential strategies to address them.LIMITATIONS The extent of transportation challenges cannot be discerned because this is a qualitative study.CONCLUSIONS Transportation is difficult for Latino children with medical complexity, who rely on non-emergency medical transportation to access medical services. Care coordinators play a major role in addressing transportation problems for Latino children with medical complexity and their caregivers.

Communication Challenges Faced by Spanish-Speaking Caregivers of Children with Medical Complexity: a Qualitative Study.

BACKGROUND: Communication between caregivers and healthcare providers is important in the delivery of high-quality healthcare for children with medical complexity (CMC). Hispanic children face many challenges in access to healthcare services. Our objective was to describe the communication challenges faced by Spanish-speaking parents with limited English proficiency (SSP-LEP). METHODS: This was a qualitative study of 70 children of Spanish-speaking caregivers, enrolled in a complex care program of a tertiary care children's hospital in North Carolina. Secondary source data were abstracted logs of care coordination tasks maintained by the program's two bilingual care coordinators for a median observation period of 45 months, and complemented by data from care coordinator interviews. Data were entered and coded in ATLAS.ti. Using thematic content analysis and an iterative process, we identified recurrent themes related to communication challenges of Spanish-speaking caregivers. RESULTS: Median age of children was 5 years; 51% were girls; 97% had Medicaid; and 3% were uninsured. Seven children died during the observation period. Three major themes were identified as follows: (1) caregivers faced many communication challenges primarily because of language barrier. (2) Multiple factors at caregiver, provider, and system levels, in addition to language barrier, contributed to communication challenges. (3) Communication challenges had serious consequences for CMC. These consequences were lessened by bilingual coordinators. CONCLUSION: SSP-LEP face unique communication challenges resulting in negative impact on the healthcare of their CMC. Bilingual coordinators can help improve communication between SSP-LEP and their healthcare providers. Interventions to address communication challenges of Spanish-speaking caregivers are warranted.

Intestinal microbiota modulates pancreatic carcinogenesis through intratumoral natural killer cells.

Preclinical data demonstrate that the gut microbiota can promote pancreatic ductal adenocarcinoma (PDAC), but mechanisms remain unclear. We hypothesized that intestinal microbiota alters anti-tumor innate immunity response to facilitate PDAC progression. Human PDAC L3.6pl cells were heterotopically implanted into Rag1-/- mice after microbiota depletion with antibiotics, while syngeneic murine PDAC Pan02 cells were implanted intrapancreatic into germ-free (GF) C57BL/6 J mice. Natural killer (NK) cells and their IFNγ expression were quantitated by flow cytometry. NK cells were depleted in vivo using anti-Asialo GM1 antibody to confirm the role of NK cells. Bacteria-free supernatant from SPF and GF mice feces was used to test its effect on NK-92MI cell anti-tumor response in vitro. SPF and ex-GF mice (reconstituted with SPF microbiota) developed larger PDAC tumors with decreased NK cell tumor infiltration and IFNγ expression versus GF-Rag1-/-. Microbiota-induced PDAC tumorigenesis was attenuated by antibiotic exposure, a process reversed following NK cell depletion in both Rag1-/- and C57BL/6 J mice. Compared to GF, SPF-Rag1-/- abiotic stool culture supernatant inhibited NK-92MI cytotoxicity, migration, and anti-cancer related gene expression. Gut microbiota promotes PDAC tumor progression through modulation of the intratumoral infiltration and activity of NK cells.

Practical Needs in the Home Care of Latino Children With Medical Complexity.

Latino children face barriers to high-quality healthcare. Because children with medical complexity (CMC) have higher healthcare needs, Latino CMC are likely to experience greater effects of these barriers. These vulnerabilities are exacerbated when Latino CMC endure adverse social conditions, such as food insecurity and housing instability. The study objective was to describe the challenges faced by caregivers of Latino CMC in meeting the practical needs of their children when caring for them at home. In this qualitative study, 70 Latino CMC enrolled in a complex care program of a tertiary care children's hospital were followed for a median duration of 45 months. We collected care coordination notes from encounter logs and interviewed bilingual care coordinators regarding their experiences with each child. Using thematic content analysis and an iterative process, we identified recurrent themes related to practical needs. Four themes emerged. Caregivers: 1) faced financial challenges due to many reasons that were exacerbated by children's medical conditions; 2) had challenges meeting basic needs of their families, including food and shelter; 3) experienced difficulties obtaining necessary medical supplies for their children; and 4) relied on care coordinators to navigate the system. We conclude that Latino caregivers of CMC experience many challenges meeting their families' basic needs and obtaining necessary medical supplies to care for their CMC at home. Care coordinators play a major role in addressing the practical needs of Latino CMC. Future studies should determine whether addressing the practical needs of Latino CMC would improve their health outcomes.

The pancreatic tumor microenvironment drives changes in miRNA expression that promote cytokine production and inhibit migration by the tumor associated stroma.

The pancreatic adenocarcinoma (PDAC) microenvironment is largely comprised of fibrotic tumor associated stroma (TAS) that contributes to the lethal biology of PDAC. microRNA (miRNA) are small non-coding RNAs that regulate gene expression. We hypothesized that interactions between PDAC cells and TAS cells within the microenvironment modulate miRNA expression and thus, tumor biology. We observed that miR-205 and members of the miR-200 family (miR-200a, -200b, -200c, -141 and miR-429) were exclusively expressed in PDAC cells, consistent with an epithelial miRNA signature, while miR-145 and miR-199 family members (miR-199a and -199b) were solely expressed in TAS cells, consistent with a stromal miRNA signature. This finding was confirmed by qRT-PCR of RNA obtained by laser-capture microdissection of surgical specimens. Using an in vitro co-culture model, we further demonstrated regulation of miRNA expression by cell-cell contact. Forced expression in TAS cells of miR-200b/-200c and miR-205 to mimic these observed changes in miRNA concentrations induced secretion of GM-CSF and IP10, and notably inhibited migration. These data suggest interactions within the tumor microenvironment alter miRNA expression, which in turn have a functional impact on TAS.

In Situ Transplantation of Alginate Bioencapsulated Adipose Tissues Derived Stem Cells (ADSCs) via Hepatic Injection in a Mouse Model.

OBJECTIVE: Adipose tissue derived stem cells (ADSCs) transplantation has recently gained widespread enthusiasm, particularly in the perspective to use them as potential alternative cell sources for hepatocytes in cell based therapy, mainly because of their capability of hepatogenic differentiation in vitro and in vivo. But some challenges remain to be addressed, including whether ADSCs can be provided effectively to the target organ and whether subsequent proliferation of transplanted cells can be achieved. To date, intrasplenic injection is the conventional method to deliver ADSCs into the liver; however, a number of donor cells retained in the spleen has been reported. In this study, our objective is to evaluate a novel route to transplant ADSCs specifically to the liver. We aimed to test the feasibility of in situ transplantation of ADSCs by injecting bioencapsulated ADSCs into the liver in mouse model. METHODS: The ADSCs isolated from human alpha 1 antitrypsin (M-hAAT) transgenic mice were used to allow delivered ADSCs be readily identified in the liver of recipient mice, and alginate was selected as a cell carrier. We first evaluated whether alginate microspheres are implantable into the liver tissue by injection and whether ADSCs could migrate from alginate microspheres (study one). Once proven, we then examined the in vivo fate of ADSCs loaded microspheres in the liver. Specifically, we evaluated whether transplanted, undifferentiated ASDCs could be induced by the local microenvironment toward hepatogenic differentiation and the distribution of surviving ADSCs in major tissue organs (study two). RESULTS: Our results indicated ADSCs loaded alginate microspheres were implantable into the liver. Both degraded and residual alginate microspheres were observed in the liver up to three weeks. The viable ADSCs were detectable surrounding degraded and residual alginate microspheres in the liver and other major organs such as bone marrow and the lungs. Importantly, transplanted ADSCs underwent hepatogenic differentiation to become cells expressing albumin in the liver. These findings improve our understanding of the interplay between ADSCs (donor cells), alginate (biomaterial), and local microenvironment in a hepatectomized mouse model, and might improve the strategy of in situ transplantation of ADSCs in treating liver diseases.

Physiological importance of system A-mediated amino acid transport to rat fetal development.

Fetal growth and development are dependent on the delivery of amino acids from maternal amino acid pools to the fetal blood. This is accomplished via transfer across the apical and basal plasma membrane of the placental syncytiotrophoblast. The aim of this study was to determine whether inhibition of system A (amino acid transporter) was associated with a decrease in fetal weight in the rat. System A is a ubiquitous Na(+)-dependent amino acid transporter that actively transports small zwitterionic amino acids. In brief, system A was inhibited by infusing a nonmetabolizable synthetic amino acid analog, 2-(methylamino)isobutyric acid from days 7-20 of gestation. On day 20, the rats were killed and tissues (maternal liver, fetuses, and placentas) were collected for analysis. The degree of system A inhibition was determined, as was the impact of said inhibition on fetal and maternal weights, system A-mediated placental transport, and placental system A-mediated transporter expression. Our results suggest that when system A is inhibited, fetal weight is diminished [control group: -3.55 +/- 0.04 g (n = 113), experimental group: -3.29 +/- 0.04 g (n = 128)], implying an integral role for system A transport in fetal growth and development in the rat.

Rat erythrocytes express the anionic amino acid transport protein EAAC1.

EAAC1 is a widely expressed protein which transports anionic amino acids in a Na(+)-dependent fashion. Rat erythrocytes have generally been thought to be impermeant to anionic amino acids. Utilizing immunoelectron microscopy, we have demonstrated the presence of EAAC1-immunoreactive protein within rat erythrocytes. Immunoblotting revealed the presence of an approximately 60-kDa protein, consistent with EAAC1, in erythrocyte membranes. Specificity was confirmed by peptide competition. In conclusion, EAAC1 is expressed in rat erythrocytes.