OBJECTIVE To investigate glycemic and psychosocial outcomes with hybrid closed-loop (HCL) versus user-determined insulin dosing with multiple daily injections (MDI) or insulin pump (i.e., standard therapy for most adults with type 1 diabetes). RESEARCH DESIGN AND METHODS Adults with type 1 diabetes using MDI or insulin pump without continuous glucose monitoring (CGM) were randomized to 26 weeks of HCL (Medtronic 670G) or continuation of current therapy. The primary outcome was masked CGM time in range (TIR; 70–180 mg/dL) during the final 3 weeks. RESULTS Participants were randomized to HCL (n = 61) or control (n = 59). Baseline mean (SD) age was 44.2 (11.7) years, HbA1c was 7.4% (0.9%) (57 [10] mmol/mol), 53% were women, and 51% used MDI. HCL TIR increased from (baseline) 55% (13%) to (26 weeks) 70% (10%) with the control group unchanged: (baseline) 55% (12%) and (26 weeks) 55% (13%) (difference 15% [95% CI 11, 19]; P < 0.0001). For HCL, HbA1c was lower (median [95% CI] difference −0.4% [−0.6, −0.2]; −4 mmol/mol [−7, −2]; P < 0.0001) and diabetes-specific positive well-being was higher (difference 1.2 [95% CI 0.4, 1.9]; P < 0.0048) without a deterioration in diabetes distress, perceived sleep quality, or cognition. Seventeen (9 device-related) versus 13 serious adverse events occurred in the HCL and control groups, respectively. CONCLUSIONS In adults with type 1 diabetes, 26 weeks of HCL improved TIR, HbA1c, and their sense of satisfaction from managing their diabetes compared with those continuing with user-determined insulin dosing and self-monitoring of blood glucose. For most people living with type 1 diabetes globally, this trial demonstrates that HCL is feasible, acceptable, and advantageous.

The luxCDABE operon of Photorhabdus luminescens has been cloned and engineered as an easily mobilisable cassette flanked by sites for commonly used restriction enzymes. Constitutive and promoter probe plasmids utilising the P. luminescens luxCDABE have been constructed using a number of compatible replicons and antibiotic markers. Complementary to these plasmids, a range of promoterless and constitutive luxCDABE mini-Tn5 derivatives has been constructed. The potential of coupling mini-Tn5 luxCDABE promoter probe transposons with automated luminometry and photometry to screen for mutants that exhibit growth phase variation in gene expression is demonstrated.

In Staphylococcus epidermidis and Staphylococcus aureus, a number of cell wall-and cytoplasmic membraneassociated lipoproteins are induced in response to iron starvation. To gain insights into the molecular basis of iron-dependent gene regulation in the staphylococci, we sequenced the DNA upstream of the 3-kb S. epidermidis sitABC operon, which Northern blot analysis indicates is transcriptionally regulated by the growth medium iron content. We identified two DNA sequences which are homologous to elements of the Corynebacterium diphtheriae DtxR regulon, which controls, in response to iron stress, for example, production of diphtheria toxin, siderophore, and a heme oxygenase. Upstream of the sitABC operon and divergently transcribed lies a 645-bp open reading frame (ORF), which codes for a polypeptide of approximately 25 kDa with homology to the DtxR family of metal-dependent repressor proteins. This ORF has been designated SirR (staphylococcal iron regulator repressor). Within the sitABC promoter/operator region, we also located a region of dyad symmetry overlapping the transcriptional start of sitABC which shows high homology to the DtxR operator consensus sequence, suggesting that this region, termed the Sir box, is the SirR-binding site. The SirR protein was overexpressed, purified, and used in DNA mobility shift assays; SirR retarded the migration of a synthetic oligonucleotide based on the Sir box in a metal (Fe 2؉ or Mn 2؉ )-dependent manner, providing confirmatory evidence that this motif is the SirR-binding site. Furthermore, Southern blot analysis of staphylococcal chromosomal DNA with the synthetic Sir box as a probe confirmed that there are at least five Sir boxes in the S. epidermidis genome and at least three in the genome of S. aureus, suggesting that SirR controls the expression of multiple target genes. Using a monospecific polyclonal antibody raised against SirR to probe Western blots of whole-cell lysates of S. aureus, S. carnosus, S. epidermidis, S. hominis, S. cohnii, S. lugdunensis, and S. haemolyticus, we identified an approximately 25-kDa cross-reactive protein in each of the staphylococcal species examined. Taken together, these data suggest that SirR functions as a divalent metal cation-dependent transcriptional repressor which is widespread among the staphylococci.

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