General medicine consultant of the week model shortens hospital length of stay and improves the patient journey.

BACKGROUND AND AIMS: The consultant of the week (COW) model of inpatient care means the consultants' primary focus is to deliver ward-based care daily. At Sandwell and West Birmingham Hospitals NHS Trust, a COW model has been successfully used for cardiology and stroke services. This has improved continuity of care and developed a 7-day working week. Our aim was to extend this model to all general medical consultants who manage inpatients. METHODS: We introduced the COW model to the unselected general medical take. Restructuring of consultant job plans allowed daily ward presence, 5 days per week. Outcome measures included length of stay (LOS) and accuracy of expected date of discharge (EDD). RESULTS: LOS over a 12-month period improved from an average of 9.17 days to 6.61 days. The number of EDD changes reduced, from a previous average of 3.0 changes to 1.8 changes. Consultant feedback showed there was an improvement in collaboration between teams, improved training of junior doctors and higher job satisfaction. CONCLUSIONS: Improved 5-day consultant presence is associated with reduced LOS. Learning points included the delay in implementation due to the complexity of consultant job planning. We plan to extend COW to 7-days for all general medical wards.

STIM1 signalling controls store-operated calcium entry required for development and contractile function in skeletal muscle.

It is now well established that stromal interaction molecule 1 (STIM1) is the calcium sensor of endoplasmic reticulum stores required to activate store-operated calcium entry (SOC) channels at the surface of non-excitable cells. However, little is known about STIM1 in excitable cells, such as striated muscle, where the complement of calcium regulatory molecules is rather disparate from that of non-excitable cells. Here, we show that STIM1 is expressed in both myotubes and adult skeletal muscle. Myotubes lacking functional STIM1 fail to show SOC and fatigue rapidly. Moreover, mice lacking functional STIM1 die perinatally from a skeletal myopathy. In addition, STIM1 haploinsufficiency confers a contractile defect only under conditions where rapid refilling of stores would be needed. These findings provide insight into the role of STIM1 in skeletal muscle and suggest that STIM1 has a universal role as an ER/SR calcium sensor in both excitable and non-excitable cells.

Homer modulates NFAT-dependent signaling during muscle differentiation.

While changes in intracellular calcium are well known to influence muscle contraction through excitation contraction coupling, little is understood of the calcium signaling events regulating gene expression through the calcineurin/NFAT pathway in muscle. Here, we demonstrate that Ca(+2) released via the inositol trisphosphate receptor (IP3R) increases nuclear entry of NFAT in undifferentiated skeletal myoblasts, but the IP3R Ca(+2) pool in differentiated myotubes promotes nuclear exit of NFAT despite a comparable quantitative change in [Ca(+2)]i. In contrast, Ca(+2) released via ryanodine receptors (RYR) increases NFAT nuclear entry in myotubes. The scaffolding protein Homer, known to interact with both IP3R and RYR, is expressed as part of the myogenic differentiation program and enhances NFAT-dependent signaling by increasing RYR Ca(+2) release. These results demonstrate that differentiated skeletal myotubes employ discrete pools of intracellular calcium to restrain (IP3R pool) or activate (RYR pool) NFAT-dependent signaling, in a manner distinct from undifferentiated myoblasts. The selective expression of Homer proteins contributes to these differentiation-dependent features of calcium signaling.

A mutation in the TRPC6 cation channel causes familial focal segmental glomerulosclerosis.

Focal and segmental glomerulosclerosis (FSGS) is a kidney disorder of unknown etiology, and up to 20% of patients on dialysis have been diagnosed with it. Here we show that a large family with hereditary FSGS carries a missense mutation in the TRPC6 gene on chromosome 11q, encoding the ion-channel protein transient receptor potential cation channel 6 (TRPC6). The proline-to-glutamine substitution at position 112, which occurs in a highly conserved region of the protein, enhances TRPC6-mediated calcium signals in response to agonists such as angiotensin II and appears to alter the intracellular distribution of TRPC6 protein. Previous work has emphasized the importance of cytoskeletal and structural proteins in proteinuric kidney diseases. Our findings suggest an alternative mechanism for the pathogenesis of glomerular disease.

Control of facial muscle development by MyoR and capsulin.

Members of the MyoD family of basic helix-loop-helix (bHLH) transcription factors control the formation of all skeletal muscles in vertebrates, but little is known of the molecules or mechanisms that confer unique identities to different types of skeletal muscles. MyoR and capsulin are related bHLH transcription factors expressed in specific facial muscle precursors. We show that specific facial muscles are missing in mice lacking both MyoR and capsulin, reflecting the absence of MyoD family gene expression and ablation of the corresponding myogenic lineages. These findings identify MyoR and capsulin as unique transcription factors for the development of specific head muscles.

TRPC3 channels confer cellular memory of recent neuromuscular activity.

Skeletal muscle adapts to different patterns of motor nerve activity by alterations in gene expression that match specialized properties of contraction, metabolism, and muscle mass to changing work demands (muscle plasticity). Calcineurin, a calcium/calmodulin-dependent, serine-threonine protein phosphatase, has been shown to control programs of gene expression in skeletal muscles, as in other cell types, through the transcription factor nuclear factor of activated T cells (NFAT). This study provides evidence that the function of NFAT as a transcriptional activator is regulated by neuromuscular stimulation in muscles of intact animals and that calcium influx from the transient receptor potential (TRPC3) channel is an important determinant of NFAT activity. Expression of TRPC3 channels in skeletal myocytes is up-regulated by neuromuscular activity in a calcineurin-dependent manner. These data suggest a mechanism for cellular memory in skeletal muscles whereby repeated bouts of contractile activity drive progressively greater remodeling events.