Lipochromosome mediated gene transfer: identification and probable specificity of localization of human chromosomal material and stability of the transferents

Effect on breastfeeding practices of providing in-home lactation support to vulnerable women through the Canada Prenatal Nutrition Program: protocol for a pre/post intervention study

Background

Only one-third of Canadian infants are exclusively breastfed for the first 6 months of life as recommended. Skilled lactation support in the early postpartum period is one strategy for improving breastfeeding outcomes by building breastfeeding self-efficacy and resolving difficulties. Access to such support is limited among vulnerable women, including those who are new immigrants, low income, under-educated, young or single. The Canada Prenatal Nutrition Program (CPNP) aims to improve birth and breastfeeding outcomes among vulnerable women, but currently lacks a formal framework for providing postpartum lactation support.

Methods

This pre/post intervention study will examine the effect on breastfeeding outcomes of an evidence-based in-home lactation support intervention provided through the CPNP. We will enrol 210 pregnant women who intend to breastfeed and are registered CPNP clients at two sites in Toronto, Canada. During the intervention phase, postpartum home visits by International Board Certified Lactation Consultants (IBCLCs) will be pro-actively offered to registered clients of the two sites. Double-electric breast pumps will also be provided to those who meet specific criteria. Infant feeding data will be collected prospectively at seven time points from 2 weeks to 6 months postpartum. Descriptive and regression analyses will be conducted to measure intervention effects. The primary outcome is exclusive breastfeeding at 4 months postpartum. Secondary outcomes include the duration of any and exclusive breastfeeding, timing of introduction of breastmilk substitutes and timing of introduction of solid foods. Breastfeeding self-efficacy will be assessed prenatally and at 2 weeks and 2 months postpartum. Other measures include maternal socio-demographics, infant feeding intentions, maternal depression and anxiety, and household food insecurity. Monitoring data will be used to assess the reach, uptake and fidelity of intervention delivery.

Discussion

Increasing access to skilled lactation support through the CPNP may be an effective means of improving breastfeeding practices among vulnerable women and thereby enhancing health and development outcomes for their infants. This pre/post intervention study will contribute evidence on both the effectiveness and feasibility of this approach, in order to guide the development and further testing of appropriate models of integrating lactation support into the CPNP.

Trial registration

ClinicalTrials.gov (NCT03589963) registered July 18, 2018.

Introduction of purified genes into mammalian cells

There are a number of methods to introduce genes into mammalian cells. These include cell hybridization, chromosome-mediated and DNA-mediated gene transfer. DNA-mediated transfer can be achieved by direct microinjection methods or by indirect methods. The DNA enters the nucleus and is expressed in a high proportion of cells transiently. The DNA then becomes integrated into host cell DNA at random sites resulting in more stably expressing transformants. A number of genes for which selection systems exist can be introduced into mammalian cells. Nonselectable genes can also be introduced into cells by either ligating them to a selectable gene or by mixing them with carrier DNA and a selectable gene. If an amplifiable gene sequence is introduced into cells, it and other genes in its proximity can be coamplified. Amplification of the genes can also be achieved by the use of appropriate viral vectors and recipient cells. The foreign genes are expressed in the recipient cells if they contain the appropriate recognition signals for initiation and termination of transcription. Transfection systems are thus permitting identification of DNA sequences which have a regulatory role in gene expression. The identification of transcriptional signal sequences has formed the basis for construction of appropriate molecules which would permit expression of genes which cannot normally be expressed in mammalian cells (e.g., bacterial genes). The foreign genes are not only expressed in the recipient cells but they can also be subject to regulation in the appropriate environment. This observation is paving the way for identification of regulatory sequences. The foreign DNA sequences integrated into the host genome can be recovered by a variety of methods. Such methods permit isolation of genes which code for a selectable gene product.