Impact of routine clinic measurement of serum C-peptide in people with a clinician-diagnosis of type 1 diabetes.

Aims/hypothesis: The aim of this study was to determine the impact of the routine use of serum C-peptide in an out-patient clinic setting on individuals with a clinician-diagnosis of type 1 diabetes.

Methods: In this single-centre study, individuals with type 1 diabetes of at least 3 years duration were offered random serum C-peptide testing at routine clinic review. A C-peptide ≥200 pmol/L prompted further evaluation of the individual using a diagnostic algorithm that included measurement of islet cell antibodies and genetic testing.

Cleavage of claspin by caspase-7 during apoptosis inhibits the Chk1 pathway.

Claspin is required for the phosphorylation and activation of the Chk1 protein kinase by ATR during DNA replication and in response to DNA damage. This checkpoint pathway plays a critical role in the resistance of cells to genotoxic stress. Here, we show that human Claspin is cleaved by caspase-7 during the initiation of apoptosis.

DNA-dependent phosphorylation of Chk1 and Claspin in a human cell-free system.

Cell-cycle checkpoints induced by DNA damage or replication play critical roles in the maintenance of genomic integrity during cell proliferation. Biochemical analysis of checkpoint pathways has been greatly facilitated by the use of cell-free systems made from Xenopus eggs. In the present study, we describe a human cell-free system that reproduces a DNA-dependent checkpoint pathway acting on the Chk1 protein kinase.