Enteral nutrition support for infants with pulmonary hypoplasia: A qualitative evaluation of caregiver and provider perspectives

BACKGROUND

Enteral nutrition is a critical intervention that supports the growth of children with pulmonary hypoplasia (PH). We explored the experiences of caregivers and providers caring for children with PH to better understand gaps in knowledge transfer and identify barriers and facilitators to caregiving to inform interventions that may improve support.

METHODS

This qualitative study included 10 interviews with caregivers and 10 clinical team members at a single integrated care program for children with PH. An inductive and iterative coding strategy was employed to produce a codebook. After cluster analysis, themes were generated to capture participant sentiments.

RESULTS

Themes were defined along a care continuum (1) initiation, (2) adaptation, and (3) maintenance that represented distinct phases of adjustment to enteral nutrition support (1) in the perinatal period and initial neonatal intensive care unit (NICU) admission, (2) from discharge planning through the family's first days at home and establishment of a stable feeding regime, and (3) through long-term follow-up and weaning. Notable subthemes included uncertainty, partnerships in training, and obstacles to adaptation.

CONCLUSIONS

Among children with PH, the caregiver-provider relationship during the perinatal and NICU course is critical to promoting caregiver adaptation to the needs of the child. Ongoing considerations to support resource alignment and transition to a stable feeding regimen may facilitate caregiver adjustment to a "new normal," culminating in successful growth and/or weaning. These findings will inform interventions focused on training curricula, discharge planning, and the provision of follow-up in the context of an integrated care program for PH.

Choosing highly specific primers for the polymerase chain reaction using the octomer frequency disparity method: application to Chlamydia trachomatis

The eight-nucleotide sequence (octomer) at the 3' end of PCR primers is important to PCR specificity. We describe a correlation between the specificity of PCR primers used with human DNA and the frequency of the 3' octomer in a human database. We therefore applied a methodology (OFD) based on octomer frequency disparity to identify 16 PCR targets in the chromosome of the intracellular bacterium, Chlamydia trachomatis (Ct). In addition, the 16 sets of primers were tested with a standard procedure. All the primer pairs were highly specific for Ct and did not lead to non-specific amplification when used with human DNA. This work shows that the choice of specific PCR primers is possible using a method based on the statistical representativeness of octomers in genomes.

Ethanol-induced signal transducing mechanism associated with a transient antiviral state in human amniotic cells

Short-term effects of ethanol on human amnion cells were investigated by studying the cellular signaling processes and the replication of vesicular stomatitis virus. Treatment of human amniotic cells with ethanol transiently triggers the breakdown of inositol phospholipids, stimulates intracellular [Ca2+]i mobilization and activates the translocation of protein kinase C. Activation of this signal transduction mechanism is associated with the development of an antiviral state, as proven by studying 3H-uridine incorporation into the RNA of vesicular stomatitis virus. Induction of the antiviral state in human amniotic cells correlates with the solubility of the alcohols in the lipid membrane of the cells.

Signal transducing mechanisms in interferon action (a brief review)

Experimental results suggest that protein kinase C (PK-C) may play a substantial role in the action of IFNs, but the precise biochemical pathway remains unknown. Recent evidences reveal the complexity of the mechanism of IFN-action and show that the IFN-alpha, -beta and -gamma induced pathways are overlapping. We briefly discuss what is known in this field and suggest a way in which the contrasting views might be reconciled.

Phospholipase C and phospholipase A2 are involved in the antiviral activity of human interferon-alpha

Treatment of human amniotic cells (UAC) with human interferon-alpha (Hu-IFN alpha) or phorbol myristate acetate (PMA) resulted in translocation of protein kinase C (PK-C) activity from the cytosol fraction to that of the membranes. Analysis of 32P incorporation into phospholipid fractions and studies of alterations in fatty acid content for the major phospholipids of IFN-treated cells suggest that phospholipases C and A2 are activated by Hu-IFN alpha. Addition of neomycin (an inhibitor of phospholipase C), as well as mepacrine (an inhibitor of phospholipase A2) to IFN-treated cells inhibited the antiviral activity of Hu-IFN alpha in the vesicular stomatitis virus (VSV)-UAC system used. These observations indicate that (i) activation of PK-C and (ii) diacylglycerol formation, arachidonic acid and/or lysophosphatidylcholine release are important steps in the mechanism of action of IFN.

Interferon (IFN)-like antiviral effect is induced by unspecific cross-linking of cell surface receptors

Treatment of human amniotic cells (UAC) with Cytodex 1 (DEAE-dextran) results in the development of an antiviral state of the cells, as proven by studying (i) the cytopathic effect and (ii) [3H]uridine incorporation into the RNA of vesicular stomatitis virus (VSV) after VSV infection. The same treatment transiently triggers the breakdown of inositol phospholipids and activates the translocation of protein kinase C (PKC). On the basis of these data it can be suggested that cross-linking of cell surface receptors by a solid carrier bearing covalently bound positive charges may result in IFN-like effects.

Inositol phospholipid turnover and protein kinase C translocation are stimulated by poly(I).poly(C) in human amnion cells (UAC)

Polyinosinic-polycytidylic acid, a potent inducer of inducer of interferon (IFN) production and activator of some IFN-induced enzymes, inhibits [3H]uridine incorporation into the RNA of vesicular stomatitis virus even in the absence of IFN synthesis, transiently triggers the breakdown of inositol phospholipids and activates the translocation of protein kinase C. Since IFNs also have similar activities these results suggest that IFN induction and IFN function are realised through common biochemical pathways.

Antiviral activity of phorbol myristate acetate and possible relationships with interferon action

Signal-induced turnover of membrane phospholipids represents a fundamental transducing mechanism that induces a signal cascade resulting in mobilization of calcium, activation of protein kinase C by diacylglycerol, release of arachidonic acid and stimulation of cyclic GMP production. In this pathway tumor-promoting phorbol esters such as phorbol myristate acetate (PMA) may substitute for diacylglycerol. The interferon-like antiviral effect of PMA described here suggests that the inositol phospholipid-diacylglycerol-protein kinase C signal-transducing mechanism may be involved in interferon action.

[Effect of the medium composition on the synthesis of protease by Aspergillus sp]

The main regulatory mechanisms controlling the synthesis of neural protease in batch cultures of a strain of Aspergillus were studied. Protease was inducible in this strain. No activity appeared during the trophophase when the organism was grown in a minimal medium, unless an inducer was added. Gelatine had the best induction effect among all the tested substances. The growth kinetics and enzyme production in a culture medium containing gelatine as the sole carbon and nitrogen source was determined. In spite of these results, protease activity was clearly detectable during the idiophase in absence of an external inducer. Furthermore, the addition of gelatine to cultures during the idiophase resulted in a decrease of the enzyme activity. This behaviour could be due to internal autoinduction generated by accelerated protein turnover of the nitrogen starved cells. The addition of gelatine probably reduced the protein starvation. Protease synthesis was sensitive to repression by rapidly assimilable carbon sources such as glucose and glycerol. Ammonia also caused an important repression, while nitrate and amino nitrogen had no effect. It was concluded that the synthesis of this enzyme is controlled by induction, catabolite repression, and ammonia repression, and that the enzyme production period could be adjusted by adequate formulation of the culture medium.

Dissimilatory nitrate reduction by liquid membrane encapsulated cell-free extracts and whole cells of Micrococcus denitrificans

The combination of Sephadex G-15 and ion-exchange resin columns allows one-step desalting and separation of cellodextrins using water as the sole eluent. The column apparatus described in this paper has the potential of producing up to 3 g cellodextrins in one day. In addition, the columns described are stable and do not require repacking or regeneration after each run. Hence the potential exists for scaling up this system for even greater production of cellodextrins if need be.