Important Role of the GLP-1 Axis for Glucose Homeostasis after Bariatric Surgery

Bariatric surgery is widely used to treat obesity and improves type 2 diabetes beyond expectations from the degree of weight loss. Elevated post-prandial concentrations of glucagon-like peptide 1 (GLP-1), peptide YY (PYY), and insulin are widely reported, but the importance of GLP-1 in post-bariatric physiology remains debated. Here, we show that GLP-1 is a major driver of insulin secretion after bariatric surgery, as demonstrated by blocking GLP-1 receptors (GLP1Rs) post-gastrectomy in lean humans using Exendin-9 or in mice using an anti-GLP1R antibody. Transcriptomics and peptidomics analyses revealed that human and mouse enteroendocrine cells were unaltered post-surgery; instead, we found that elevated plasma GLP-1 and PYY correlated with increased nutrient delivery to the distal gut in mice. We conclude that increased GLP-1 secretion after bariatric surgery arises from rapid nutrient delivery to the distal gut and is a key driver of enhanced insulin secretion.

Progress with the implementation of kangaroo mother care in four regions in Ghana

AIM

To measure progress with the implementation of kangaroo mother care (KMC) for low birth-weight (LBW) infants at a health systems level.

DESIGN

Action research design, with district and regional hospitals as the unit of analysis.

SETTING

Four regions in Ghana, identified by the Ghana Health Service and UNICEF.

PARTICIPANTS

Health workers and officials, health care facilities and districts in the four regions.

INTERVENTION

A one-year implementation programme with three phases: (1) introduction to KMC, skills development in KMC practice and the management of implementation; (2) advanced skills development for regional steering committee members; and (3) an assessment of progress at the end of the intervention.

MAIN OUTCOME MEASURES

Description of practices, services and facilities for KMC and the identification of strengths and challenges.

RESULTS

Twenty-six of 38 hospitals (68%) demonstrated sufficient progress with KMC implementation. Half of the hospitals had designated a special ward for KMC. 66% of hospitals used a special record for infants receiving KMC. Two of the main challenges were lack of support for mothers who had to remain with their LBW infants in hospital and no follow-up review services for LBW infants in 39% of hospitals.

CONCLUSIONS

It was possible to roll out KMC in Ghana, but further support for the regions is needed to maintain the momentum. Lessons learned from this project could inform further scale-up of KMC and other projects in Ghana.

Modifications of the hydrophilicity of heterocyclic methacrylate copolymers for protein release

A series of copolymers comprising ethyl methacrylate (EM) and tetrahydrofurfuryl methacrylate (THFMA) gelled with either THFMA monomer or hydroxyethyl methacrylate (HEMA) monomer have been developed. In this paper, we examine the water uptake characteristics of the polymer systems and address the possibility of increasing the hydrophilicity of the systems by changing the ratios of the copolymers. We have investigated whether protein release from the polymers is related to the composition of the polymer systems. More protein was released from the polymers gelled with the more hydrophilic monomer (HEMA) than with THFMA. This was consistent with the calculated diffusion coefficients, which were 10 times greater for the polymers gelled with HEMA than those gelled with THFMA. Interestingly, the water uptake and protein release profiles were not dependent on the ratio of EM and THFMA in the copolymers. This is probably due to the conflicting roles of THFMA in the copolymer; it is both the more hydrophilic component as well as a cross-linking agent. In addition, it would appear that the structural and surface topography of these polymers had more significant effects on protein release than copolymer composition.

The migration of osteoblasts over substrata of discrete surface charge

Osteoblasts, from the endocranial surface of neonate rat parietal bones, migrated over ion-exchange resin beads and phase-separation beads in vitro. The morphology of migrated osteoblasts was examined using a scanning electron microscope. The ion-exchange resin beads were either positively or negatively surface charged. The phase-separation model system described, using poly(methyl methacrylate) (PMMA) and lead poly-acrylate (LPA), presented morphologically discrete regions of positive and negative surface charge to single migrating osteoblasts. Osteoblasts migrated over both positively and negatively charged substrata. Close approximation of cells was noted on positively charged surfaces while a 'stand-off' morphology was characteristic of cells on negatively charged substrata. Dorsal cell-surface membrane activity was influenced by the surface charge of the colonized substratum.