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Aim: To explore adults with diabetes and clinician views of point‐of‐care HbA1c testing. Methods: Adults with diabetes and HbA1c ≥ 58 mmol/mol (7.5%) receiving HbA1c point‐of‐care testing in primary care were invited to individual interviews. Participants were interviewed twice, once prior to point‐of‐care testing and once after 6 months follow‐up. Clinicians were interviewed once. A thematic framework based on an a priori framework was used to analyse the data. Results: Fifteen participants (eight women, age range 30–70 years, two Asians, 13 white Europeans) were interviewed. They liked point‐of‐care testing and found the single appointment more convenient than usual care. Receiving the test result at the appointment helped some people understand how some lifestyle behaviours affected their control of diabetes and motivated them to change behaviours. Receiving an immediate test result reduced the anxiety some people experience when waiting for a result. People thought there was little value in using point‐of‐care testing for their annual review. Clinicians liked the point‐of‐care testing but expressed concerns about costs. Conclusions: This work suggests that several features of point‐of‐care testing may encourage behavioural change. It helped some people to link their HbA1c result to recent lifestyle behaviours, thereby motivating behavioural change and reinforcing healthy lifestyle choices.

Objective To assess the diagnostic accuracy of glycated haemoglobin A1c (HbA1c), compared to fasting plasma glucose (FPG) and the oral glucose tolerance test (OGTT), in screening for type 2 diabetes (T2D) in Africa. Methods We systematically searched databases for studies that compared the HbA1c to either the OGTT, or the FPG for T2D diagnosis were included. The QUADAS 2 tool was used for assessing the quality of included studies. We used the split component synthesis (SCS) method for the meta-analysis of diagnostic accuracy studies to pool the studies for meta-analysis of sensitivity and specificity, primarily at the HbA1c ≥48 mmol/mol (6.5%) cut-off and at other cut-offs. We assessed heterogeneity using the I2 statistic and publication bias using Doi plots. Results Eleven studies, from seven African countries, with 12,925 participants, were included. Against the OGTT, HbA1c ≥48 mmol/mol (6.5%) had a pooled sensitivity of 57.7% (95% confidence interval [CI] 43.4–70.9) and specificity of 92.3% (95% CI 83.9–96.5). Against the FPG, HbA1c ≥48 mmol/mol (6.5%) had a pooled sensitivity of 64.5% (95% CI 50.5–76.4) and specificity of 94.3% (95% CI 87.9–97.5). The highest sensitivity for HbA1c, against the OGTT, was at the 42 mmol/mol (6.0%) cut-off. Conclusion In Africa, the HbA1c ≥48 mmol/mol (6.5%) cut-off may miss almost half of the individuals with T2D based on blood glucose measures.

Biallelic mutations in AP5Z1 are known to cause a rare, autosomal recessive, complex form of hereditary spastic paraplegia (HSP) referred to as SPG48 (MIM#613647)[1]. To date, only 11 SPG48 cases have been reported. The clinical spectrum of SPG48 is complex and heterogeneous, presenting with neuropathy, ataxia, dystonia and parkinsonism in addition to the spastic paraplegia (SP). AP5Z1 codes for the ζsubunit of the AP-5 complex, implicated in vesicular-mediated intracellular sorting and trafficking of cargo proteins[1] and functional studies demonstrate accumulation of multilamellar structures(endolysosomes) in SPG48 skin fibroblasts[2].

The hereditary spastic paraplegias (HSPs) are a heterogeneous group of disorders characterized by degeneration of the corticospinal and spinocerebellar tracts leading to progressive spasticity. One subtype, spastic paraplegia type 47 (SPG47 or HSP-AP4B1), is due to bi-allelic loss-of-function mutations in the AP4B1 gene. AP4B1 is a subunit of the adapter protein complex 4 (AP-4), a heterotetrameric protein complex that regulates the transport of membrane proteins. Since 2011, 11 individuals from six families with AP4B1 mutations have been reported, nine of whom had homozygous mutations and were from consanguineous families. Here we report eight patients with AP4B1-associated SPG47, the majority born to non-consanguineous parents and carrying compound heterozygous mutations. Core clinical features in this cohort and previously published patients include neonatal hypotonia that progresses to spasticity, early onset developmental delay with prominent motor delay and severely impaired or absent speech development, episodes of stereotypic laughter, seizures including frequent febrile seizures, thinning of the corpus callosum, and delayed myelination/white matter loss. Given that some of the features of AP-4 deficiency overlap with those of cerebral palsy, and the discovery of the disorder in non-consanguineous populations, we believe that AP-4 deficiency may be more common than previously appreciated.

© 2014 The British Pharmacological Society. Aims Although there are reports that β-adrenoceptor antagonists (beta-blockers) and diuretics can affect glycaemic control in people with diabetes mellitus, there is no clear information on how blood glucose concentrations may change and by how much. We report results from a systematic review to quantify the effects of these antihypertensive drugs on glycaemic control in adults with established diabetes. Methods We systematically reviewed the literature to identify randomized controlled trials in which glycaemic control was studied in adults with diabetes taking either beta-blockers or diuretics. We combined data on HbA 1c and fasting blood glucose using fixed effects meta-analysis. Results From 3864 papers retrieved, we found 10 studies of beta-blockers and 12 studies of diuretics to include in the meta-analysis. One study included both comparisons, totalling 21 included reports. Beta-blockers increased fasting blood glucose concentrations by 0.64 mmol l -1 (95% CI 0.24, 1.03) and diuretics by 0.77 mmol l -1 (95% CI 0.14, 1.39) compared with placebo. Effect sizes were largest in trials of non-selective beta-blockers (1.33, 95% CI 0.72, 1.95) and thiazide diuretics (1.69, 95% CI 0.60, 2.69). Beta-blockers increased HbA 1c concentrations by 0.75% (95% CI 0.30, 1.20) and diuretics by 0.24% (95% CI -0.17, 0.65) compared with placebo. There was no significant difference in the number of hypoglycaemic events between beta-blockers and placebo in three trials. Conclusions Randomized trials suggest that thiazide diuretics and non-selective beta-blockers increase fasting blood glucose and HbA 1c concentrations in patients with diabetes by moderate amounts. These data will inform prescribing and monitoring of beta-blockers and diuretics in patients with diabetes.

The adaptor proteins (APs) are a family of five heterotetrameric complexes with important functions in vesicle trafficking. While the roles of APs 1-3 are broadly established, comparatively little is known about AP-4 and AP-5. Current evidence suggests that AP-4 mediates TGN to endosome transport of specific cargo proteins, such as the amyloid precursor protein APP, and that it is involved in basolateral sorting in polarized cells. Furthermore, several independent studies have reported human patients with mutations in AP-4 genes. AP-4 deficiency causes severe intellectual disability and progressive spastic para- or tetraplegia, supporting an important role for AP-4 in brain function and development. The newly discovered AP-5 complex appears to be involved in endosomal dynamics; its precise localization and function are still unclear. Intriguingly, AP-5 deficiency is also associated with progressive spastic paraplegia, suggesting that AP-5, like AP-4, plays a fundamental role in neuronal development and homeostasis. The unexpected phenotypic parallels between AP-4 and AP-5 patients may in turn suggest a functional relationship of the two APs in vesicle trafficking.

Diabet. Med. 28, 1182–1187 (2011) Abstract Aims Renin–angiotensin inhibitors in Type 2 diabetes and microalbuminuria reduce renal and cardiovascular risk, but evidence supporting use of maximal tolerated dose is unclear. We aimed to determine the extent of renin–angiotensin inhibitor dose-dependent effects from randomized trials carried out in a clinical setting. Methods In a meta-analysis of randomized clinical trials, alternate doses of angiotensin receptor blockers or angiotensin converting enzyme inhibitors in patients with Type 2 diabetes and microalbuminuria were compared. MEDLINE, EMBASE and the Cochrane Register of Controlled Trials were searched from January 2006 to August 2010. Trials prior to January 2006 were identified from a prior systematic review. Identified outcomes were albumin excretion rate, progression and regression of albuminuria and adverse events. Results Four trials including 1051 patients compared doses of angiotensin receptor blockers. No trials compared doses of angiotensin converting enzyme inhibitor. The percentage decline in albumin excretion rate from baseline was greater with higher doses (18% higher, 95% CI 8–28%), the regression to normoalbuminuria was greater (OR 1.66, 95% CI 1.22–2.27), with less progression to macroalbuminuria (OR 0.62, CI 0.38–1.02). Adverse events were fewer with lower-dose angiotensin receptor blockers (OR 1.32, 95% CI 0.90–1.92). Conclusions Higher-dose compared with lower-dose angiotensin receptor blockers in Type 2 diabetes with microalbuminuria are associated with significantly reduced albumin excretion rate and increased regression to normoalbuminuria. Adverse events are more frequent, but not significantly so. There is potential for trials to determine clinical cardiovascular and renal outcomes at differing doses. Our findings support current recommendations to titrate renin–angiotensin inhibitors to maximum dose whilst considering risk of adverse side effects with higher doses.

The GGAs [Golgi-localised, gamma-ear containing, ARF (ADP ribosylation factor)-binding proteins] and the AP-1 (adaptor protein-1) complex are both adaptors for clathrin-mediated intracellular trafficking, but their relationship to each other is unclear. We have used two complementary systems, HeLa cells and Drosophila Dmel2 cells, to investigate GGA and AP-1 function. Immunoelectron microscopy of endogenous AP-1 and GGA in Dmel2 cells shows that they are predominantly associated with distinct clathrin-coated structures. Depletion of either GGA or AP-1 by RNAi does not affect the incorporation of the other adaptor into clathrin-coated vesicles (CCVs), and the cargo protein GFP-LERP (green fluorescent protein-lysosomal enzyme receptor protein) is lost from CCVs only when both adaptors are depleted. Similar results were obtained using HeLa cells treated with siRNA to deplete all three GGAs simultaneously. AP-1 was still incorporated into CCVs after GGA depletion and vice versa, and both needed to be depleted for a robust inhibition of receptor-mediated sorting of lysosomal hydrolases. In contrast, downregulation of major histocompatibility complex (MHC) class I by HIV-1 Nef, which requires AP-1, was not affected by a triple GGA knockdown. Thus, our results indicate that the two adaptors can function independently of each other.

Auxilin is a cofactor for Hsc70-mediated uncoating of clathrin-coated vesicles (CCVs). However, small interfering RNA (siRNA) knockdown of the ubiquitous auxilin 2 in HeLa cells only moderately impairs clathrin-dependent trafficking. In this study, we show that HeLa cells also express auxilin 1, previously thought to be neuron specific, and that both auxilins need to be depleted for inhibition of clathrin-mediated endocytosis and intracellular sorting. Depleting both auxilins cause an approximately 50% reduction in the number of clathrin-coated pits at the plasma membrane but enhances the association of clathrin and adaptors with intracellular membranes. CCV fractions isolated from auxilin-depleted cells have an approximately 1.5-fold increase in clathrin content and more than fivefold increase in the amount of AP-2 adaptor complex and other endocytic machinery, with no concomitant increase in cargo. In addition, the structures isolated from auxilin-depleted cells are on average smaller than CCVs from control cells and are largely devoid of membrane, indicating that they are not CCVs but membraneless clathrin cages. Similar structures are observed by electron microscopy in intact auxilin-depleted HeLa cells. Together, these findings indicate that the two auxilins have overlapping functions and that they not only facilitate the uncoating of CCVs but also prevent the formation of nonproductive clathrin cages in the cytosol.