Infant Feeding Practices and Social Support Networks Among Immigrant Chinese American Mothers With Economic Disadvantage in New York City.

BACKGROUND: Maternal social support promotes healthy infant feeding practices, which influence healthy growth and development. Less is known about how the interplay of social support networks and multicultural health beliefs may influence infant feeding practices, particularly among immigrant Chinese American mothers with economic disadvantage and low breastfeeding rates. RESEARCH AIM: To explore the role of social support networks in the development of infant feeding practices in immigrant Chinese American mothers with infants. METHODS: This was a prospective, cross-sectional qualitative study where we conducted semi-structured interviews in Mandarin, Cantonese, or English with Chinese American mothers of infants (N = 25) at a federally qualified health center in the Sunset Park neighborhood of Brooklyn, New York. Data were analyzed by a multicultural, multidisciplinary team using qualitative thematic analysis and the constant comparative method to identify and iteratively refine emerging codes. RESULTS: Three themes emerged describing how broad transnational communities and close family and friends influence maternal-infant feeding practices: (1) Gathering and processing infant feeding information from broad transnational resources (i.e., from both the mother's country of residence and the mother's country of origin); (2) aligning maternal feeding attitudes with cultural health beliefs of local social networks; and (3) gaining confidence with transactional maternal-infant feeding interactions. CONCLUSIONS: Strategies to promote healthy infant feeding should consider how family supports and culturally-relevant coaching can help align multilevel transnational social networks with healthy infant feeding practices.

Material Hardship and Stress from COVID-19 in Immigrant Chinese American Families with Infants.

Material hardship and stress, associated with poor infant outcomes, increased during the Coronavirus Disease 2019 pandemic. Chinese American families were vulnerable to racism-driven disparities. Little is known about maternal perceptions of pandemic impacts on their infants, family, and community. Purposive sampling of low-income Chinese American mothers (n = 25) with infants (1-15 months). Semi-structured qualitative interviews conducted in Mandarin, Cantonese, or English were audio-recorded, transcribed, and translated. Transcripts coded using applied thematic analysis in an iterative process of textual analysis until thematic saturation. Three themes emerged: (1) Heightened family hardship included financial strain, disruption of transnational childcare, experiences of racism; (2) Altered infant routines/developmental consequences included using protective equipment on infants, concerns about infant socio-emotional development; (3) Coping strategies included stockpiling essentials, adapting family diets. Strategies to mitigate disparities include expanding social needs screening, correcting misinformation, strengthening support networks, and including low-income Chinese Americans in these efforts.

Alteration at translational but not transcriptional level of transferrin receptor expression following manganese exposure at the blood-CSF barrier in vitro.

Manganese exposure alters iron homeostasis in blood and cerebrospinal fluid (CSF), possibly by acting on iron transport mechanisms localized at the blood-brain barrier and/or blood-CSF barrier. This study was designed to test the hypothesis that manganese exposure may change the binding affinity of iron regulatory proteins (IRPs) to mRNAs encoding transferrin receptor (TfR), thereby influencing iron transport at the blood-CSF barrier. A primary culture of choroidal epithelial cells was adapted to grow on a permeable membrane sandwiched between two culture chambers to mimic blood-CSF barrier. Trace (59)Fe was used to determine the transepithelial transport of iron. Following manganese treatment (100 microM for 24 h), the initial flux rate constant (K(i)) of iron was increased by 34%, whereas the storage of iron in cells was reduced by 58%, as compared to controls. A gel shift assay demonstrated that manganese exposure increased the binding of IRP1 and IRP2 to the stem loop-containing mRNAs. Consequently, the cellular concentrations of TfR proteins were increased by 84% in comparison to controls. Assays utilizing RT-PCR, quantitative real-time reverse transcriptase-PCR, and nuclear run off techniques showed that manganese treatment did not affect the level of heterogeneous nuclear RNA (hnRNA) encoding TfR, nor did it affect the level of nascent TfR mRNA. However, manganese exposure resulted in a significantly increased level of TfR mRNA and reduced levels of ferritin mRNA. Taken together, these results suggest that manganese exposure increases iron transport at the blood-CSF barrier; the effect is likely due to manganese action on translational events relevant to the production of TfR, but not due to its action on transcriptional, gene expression of TfR. The disrupted protein-TfR mRNA interaction in the choroidal epithelial cells may explain the toxicity of manganese at the blood-CSF barrier.

In vitro activity of doripenem (S-4661) against multidrug-resistant gram-negative bacilli isolated from patients with cystic fibrosis.

Doripenem 50% inhibitory concentrations (MIC50) and 90% inhibitory concentrations (MIC90) for multidrug-resistant strains of mucoid Pseudomonas aeruginosa (n=200 strains), nonmucoid P. aeruginosa (n=200), and Burkholderia cepacia complex (n=200) isolated from patients with cystic fibrosis were 8 and 32, 8 and 64, and 8 and 32 microg/ml, respectively. Doripenem had somewhat better activity than established antimicrobial agents.

Establishment and characterization of an immortalized Z310 choroidal epithelial cell line from murine choroid plexus.

The choroid plexus plays a wide range of roles in brain development, maturation, aging process, endocrine regulation, and pathogenesis of certain neurodegenerative diseases. To facilitate in vitro study, we have used a gene transfection technique to immortalize murine choroidal epithelial cells. A viral plasmid (pSV3neo) was inserted into the host genome of primary choroidal epithelia by calcium phosphate precipitation. The transfected epithelial cells, i.e., Z310 cells, that survived from cytotoxic selection expressed SV40 large-T antigen throughout the life span, suggesting a successful gene transfection. The cells displayed the same polygonal epithelial morphology as the starting cells by light microscopy. Immunocytochemical studies demonstrate the presence of transthyretin (TTR), a thyroxine transport protein known to be exclusively produced by the choroidal epithelia in the CNS, in both transfected and starting cells. Western blot analyses further confirm the production and secretion of TTR by these cells. The mRNAs encoding transferrin receptor (TfR) were identified by Northern blot analyses. The cells grow at a steady rate, currently in the 110th passage with a population doubling time of 20-22 h in the established culture. When Z310 cells were cultured onto a Trans-well apparatus, the cells formed an epithelial monolayer similar to primary choroidal cells, possessing features such as an uneven fluid level between inner and outer chambers and an electrical resistance approximately 150-200 omega-cm(2). These results indicate that immortalized Z310 cells possess the characteristics of choroidal epithelia and may have the potential for application in blood-CSF barrier (BCB) research.