Dual SMAD Signaling Inhibition Enables Long-Term Expansion of Diverse Epithelial Basal Cells

Functional modeling of many adult epithelia is limited by the difficulty in maintaining relevant stem cell populations in culture. Here, we show that dual inhibition of SMAD signaling pathways enables robust expansion of primary epithelial basal cell populations. We find that TGFβ/BMP/SMAD pathway signaling is strongly activated in luminal and suprabasal cells of several epithelia, but suppressed in p63+ basal cells. In airway epithelium, SMAD signaling promotes differentiation, and its inhibition leads to stem cell hyperplasia. Using dual SMAD signaling inhibition in a feeder-free culture system, we have been able to expand airway basal stem cells from multiple species. Expanded cells can produce functional airway epithelium physiologically responsive to clinically relevant drugs, such as CFTR modulators. This approach is effective for the clonal expansion of single human cells and for basal cell populations from epithelial tissues from all three germ layers and therefore may be broadly applicable for modeling of epithelia.

Growth hormone secretion decreases with age in paediatric Prader-Willi syndrome

OBJECTIVE

Growth hormone deficiency is a common feature of Prader-Willi syndrome; however, biochemical deficiency is not uniformly demonstrated. Criteria for GH treatment in paediatric PWS vary with some countries requiring documentation of biochemical GH deficiency. Data regarding the significance of age in the interpretation of GH stimulation test results, particularly in infants, are lacking. We aimed to assess age-related trends in the prevalence of biochemical GH deficiency in infants and children with PWS.

DESIGN

A retrospective chart review was conducted. Data from children with Prader-Willi syndrome that had GH stimulation tests performed at the Hospital for Sick Children in Toronto between the years 2000 and 2012 were collected.

PATIENT

Charts of 47 children 0·4-15·5 years of age with PWS that had GH stimulation tests were reviewed.

MEASUREMENTS

Biochemical GH status in relation to age and body mass index.

RESULTS

Thirty-two of 47 patients (68%) were biochemically GH deficient. GH deficiency was significantly associated with older age (r = 0·45, P = 0·02) and higher body-mass-index z-score (r = 0·45, P = 0·02). Biochemical GH deficiency was less prevalent up to 18 months of age (3/11 27%) compared with older children (29/36 [81%]; P = 0·001). A higher prevalence of GH deficiency was also detected in obese patients (14/16 [88%]) compared with nonobese patients (18/31 [58%]; P = 0·04).

CONCLUSIONS

The utility of performing GH stimulation tests as an indication of GH status under 18 months of age in Prader-Willi syndrome is questionable. If performed, results should be carefully interpreted in the context of age.

Pre-diabetes in adults 45 years and over in Ireland: the Survey of Lifestyle, Attitudes and Nutrition in Ireland 2007

OBJECTIVES

Pre-diabetes is an important indicator of future diabetes burden and many countries are reporting prevalence estimates of pre-diabetes. To date in Ireland, estimates of the prevalence of pre-diabetes were unavailable. Our objectives were to estimate the prevalence of pre-diabetes in a nationally representative sample of Irish adults and to explore determinants of pre-diabetes.

METHODS

The Survey of Lifestyle Attitudes and Nutrition 2007 was a cross-sectional survey on health and lifestyle in a nationally representative sample of Irish adults. Analysis was performed on a subsample of 1132 participants ≥ 45 years who provided blood samples. Determination of pre-diabetes was based on American Diabetes Association HbA1c cut points of 39-46 mmol/mol (5.7-6.4%). To explore determinants, we modelled pre-diabetes prevalence as a function of a set of health system and socio-demographic variables using logistic regression.

RESULTS

The overall weighted prevalence estimate of pre-diabetes in participants ≥ 45 years was 19.8% (95% CI 16.4-23.9). There was no significant difference between age or gender-specific prevalence rates. Obesity was significantly associated with pre-diabetes on univariate and multivariate analysis. Population attributable fraction estimates for excess BMI, physical inactivity and poor diet as causes of pre-diabetes were 31.3% (95% CI -3.9 to 54.5), 10.0% (95% CI -2.7 to 21.3) and 6.1% (95% CI -4.9 to 15.9), respectively.

CONCLUSIONS

The high levels of pre-diabetes detected in this study are worrying. Population level interventions to address diet and lifestyle factors are needed urgently to prevent progression to diabetes in high-risk individuals.

Management of dredge material in the Republic of Ireland - A review

As an island nation the Republic of Ireland's ports and harbours are key to the economic wellbeing of the country as they are the primary transport link to the United Kingdom, mainland Europe and beyond. This paper examines the main aspects of the Irish dredging industry with comparison to international practice and standards, including the source of the dredge material and volumes generated annually, the dredging plant employed and the management processes currently practised. Relevant European and Irish legislation governing dredging, disposal at sea and waste licensing are presented. The potential impacts of disposal at sea are discussed with the implications for the Irish dredging industry of recently introduced European Directives assessed. Beneficial use rates for dredge material and the techniques implemented in Ireland are examined and compared with international practice. Recent notable beneficial use projects for dredge material and proposed innovative dredge material management techniques for specific dredging projects in Ireland are presented. Proposals to encourage greater beneficial use of dredge material and minimise disposal at sea for Ireland are presented including the introduction of environmental credits, tax breaks and a grant system for pilot schemes. An alternative disposal at sea charge fee structure is also recommended to encourage alternative dredge material management practices. Ireland's management of contaminated sediment is also presented with recent projects described highlighting the current practice of primarily exporting contaminated sediment to mainland Europe. Alternative methods of treatment of contaminated sediment are assessed in an Irish context. Future issues and challenges facing the Irish dredging industry are assessed and a critical analysis of the current approaches to dredge material management is presented.

The heights and weights of Irish children from the post-war era to the Celtic tiger

BACKGROUND

Childhood obesity is a significant global health issue. National level data on long-term secular trends are relatively sparse.

METHODS

Data were obtained from three large-scale surveys of school-aged children in Ireland involving measurements of height and weight in 1948, the 1970s and 2002.

RESULTS

Significant increases in height and weight were observed in both boys and girls and in all age groups across the decades. The increases in weight were disproportionate to the trends in height. While boys aged 14 years were 23 cm taller 2002 than in 1948, their average weight was 61 kg, compared with 37 kg in 1948, an increase of 24 kg. A substantial proportion of the increase in weight is seen between the 1970s and 2002.

CONCLUSIONS

The data provide stark and compelling evidence on the evolution of the obesity epidemic in Irish children in tandem with the increase in economic prosperity.