Is new drug prescribing in primary care specialist induced?

<p>Abstract</p> <p>Background</p> <p>Medical specialists are often seen as the first prescribers of new drugs. However, the extent to which specialists influence new drug prescribing in primary care is largely unknown.</p> <p>Methods</p> <p>This study estimates the influence of medical specialists on new drug prescribing in primary care shortly after market introduction. The influence of medical specialists on prescribing of five new drugs was measured in a cohort of 103 GPs, working in 59 practices, over the period 1999 until 2003. The influence of medical specialists on new drug prescribing in primary care was assessed using three outcome measures. Firstly, the proportion of patients receiving their first prescription for a new or reference drug from a specialist. Secondly, the proportion of GPs prescribing new drugs before any specialist prescribes to their patients. Thirdly, we compared the time until the GP's first own prescribing between GPs who waited for prescriptions from specialists and those who did not.</p> <p>Results</p> <p>The influence of specialists showed considerable differences among the new drugs studied. The proportion of patients receiving their first prescription from a specialist was greatest for the combination salmeterol/fluticasone (60.2%), and lowest for rofecoxib (23.0%). The proportion of GPs prescribing new drugs before waiting for prescriptions from medical specialists ranged from 21.1% in the case of esomeprazole to 32.9% for rofecoxib. Prescribing new drugs by specialists did not shorten the GP's own time to prescribing.</p> <p>Conclusion</p> <p>This study shows that the influence of medical specialists is clearly visible for all new drugs and often greater than for the existing older drugs, but the rapid uptake of new drugs in primary care does not seem specialist induced in all cases. GPs are responsible for a substantial amount of all early prescriptions for new drugs and for a subpopulation specialist endorsement is not a requisite to initiate in new drug prescribing. This contradicts with the idea that the diffusion of newly marketed drugs always follows a two-step model, with medical specialists as the innovators and GPs as the followers.</p

Advances in shape measurement in the digital world

The importance of particle shape in terms of its effects on the behaviour of powders and other particulate systems has long been recognised, but particle shape information has been rather difficult to obtain and use until fairly recently, unlike its better-known counterpart, particle size. However, advances in computing power and 3D image acquisition and analysis techniques have resulted in major progress being made in the measurement, description and application of particle shape information in recent years. Because we are now in a digital era, it is fitting that many of these advanced techniques are based on digital technology. This review article aims to trace the development of these new techniques, highlight their contributions to both academic and practical applications, and present a perspective for future developments

Mechanical Tension Drives Elongational Growth of the Embryonic Gut

Abstract During embryonic development, most organs are in a state of mechanical compression because they grow in a confined and limited amount of space within the embryo’s body; the early gut is an exception because it physiologically herniates out of the coelom. We demonstrate here that physiological hernia is caused by a tensile force transmitted by the vitelline duct on the early gut loop at its attachment point at the umbilicus. We quantify this tensile force and show that applying tension for 48 h induces stress-dependent elongational growth of the embryonic gut in culture, with an average 90% length increase (max: 200%), 65% volume increase (max: 160%), 50% dry mass increase (max: 100%), and 165% cell number increase (max: 300%); this mechanical cue is required for organ growth as guts not subject to tension do not grow. We demonstrate that growth results from increased cell proliferation when tension is applied. These results outline the essential role played by mechanical forces in shaping and driving the proliferation of embryonic organs

Unraveling transcriptome dynamics in human spermatogenesis

Spermatogenesis is a dynamic developmental process that includes stem cell proliferation and differentiation, meiotic cell divisions and extreme chromatin condensation. Although studied in mice, the molecular control of human spermatogenesis is largely unknown. Here, we developed a protocol that enables next-generation sequencing of RNA obtained from pools of 500 individually laser-capture microdissected cells of specific germ cell subtypes from fixed human testis samples. Transcriptomic analyses of these successive germ cell subtypes reveals dynamic transcription of over 4000 genes during human spermatogenesis. At the same time, many of the genes encoding for well-established meiotic and post-meiotic proteins are already present in the pre-meiotic phase. Furthermore, we found significant cell type-specific expression of post-transcriptional regulators, including expression of 110 RNA-binding proteins and 137 long non-coding RNAs, most of them previously not linked to spermatogenesis. Together, these data suggest that the transcriptome of precursor cells already contains the genes necessary for cellular differentiation and that timely translation controlled by post-transcriptional regulators is crucial for normal development. These established transcriptomes provide a reference catalog for further detailed studies on human spermatogenesis and spermatogenic failur