Managing type 1 diabetes ‑ a journey from starvation to insulin pump

With the discovery of insulin in 1921, hopes were high that type 1 diabetes mellitus would soon be cured. However, this goal has remained elusive. Nevertheless, technological advances have improved the management of diabetes and the quality of life of patients with diabetes. One of these advances has been the development of the insulin pump. This article reviews the development of insulin pumps and outlines the advantages and disadvantages of insulin pumps currently available.

Use of a bacteriophage to inactivate Escherichia coli O157:H7 on beef

A number of outbreaks of Escherichia coli O157:H7 infections involving beef have been reported. Options for controlling bacterial pathogens in raw foods are limited, but one is to use bacteriophages (phages). We describe the isolation and characterisation of phage FAHEc1, which infects E. coli O157, and its ability to kill its host in vitro and on beef. The phage belonged to the family Myoviridae and lysed 28 of 30 E. coli O157 (:H7, :HNM and :H not specified) isolates, only one other non-O157 E. coli serotype (O162:H7), and none of the other 13 bacterial species tested. The phage did not contain stx1, stx2, eae or ehxA virulence genes as assessed by PCR. An approximate 4 log₁₀ inactivation of E. coli O157:H7 occurred at 5 °C in the presence of phage FAHEc1 at >10⁷ PFU/ml in broth in vitro. On thinly sliced beef pieces incubated at 37 °C, a > 2.7 log₁₀ reduction occurred with 3.2 × 10⁷ PFU/4 cm² meat piece. At lower phage concentrations (10³-10⁴ PFU/4 cm² piece) phage replication occurred on beef at 37 °C. When the phage was applied to beef pieces under conditions simulating hot boning and conventional carcass cooling, inactivation of E. coli O157:H7 of approximately 2 log₁₀ was measured under optimal conditions with phages applied at 3.2 × 10⁷ PFU/4 cm² meat piece.

Cranberry juice induces nitric oxide-dependent vasodilation in vitro and its infusion transiently reduces blood pressure in anesthetized rats

ABSTRACT Red wine vasodilates rat aortae, an effect attributed to polyphenolic compounds. Cranberry juice (CBJ) is also rich in polyphenols. We determined that CBJ has vasorelaxing properties similar to those of red wine. Rat aortic rings cleaned in Krebs buffer, pH 7.4, bubbled with 95% O(2) and 5% CO(2) were recovered for 30 minutes at 37 degrees C under 2.0 g tension. After phenylephrine (PE, 100 mumol/L) contraction, acetylcholine (3 mumol/L)-induced relaxation of intact vessel was significantly higher than in denuded vessels (59.1 +/- 0.27% versus 10.1 +/- 0.09% of the maximal PE contraction; P <.003). After a second PE contraction, a 1:100 dilution of CBJ was added. Intact rings were vasodilated by CBJ with 56.7 +/- 0.26% relaxation, compared to denuded rings with 8.9 +/- 0.06% relaxation (P <.002). Addition of L-NAME reversed CBJ-induced vasorelaxation in intact vessels with 0.54 +/- 0.34 g compared to 0.04 +/- 0.04 g in denuded vessels (P <.007). Subsequent addition of L-arginine resulted in a return of vasodilation in intact vessels. Additionally, CBJ infusion at a 1:100 dilution of estimated blood volume resulted in a 16% reduction of mean arterial blood pressure in anesthetized rats. This study suggests that, like red wine, CBJ has the capacity to exert in vitro and in vivo vasodilatory effects.

Mitigating hERG Inhibition: Design of Orally Bioavailable CCR5 Antagonists as Potent Inhibitors of R5 HIV-1 Replication

A series of CCR5 antagonists representing the thiophene-3-yl-methyl ureas were designed that met the pharmacological criteria for HIV-1 inhibition and mitigated a human ether-a-go-go related gene (hERG) inhibition liability. Reducing lipophilicity was the main design criteria used to identify compounds that did not inhibit the hERG channel, but subtle structural modifications were also important. Interestingly, within this series, compounds with low hERG inhibition prolonged the action potential duration (APD) in dog Purkinje fibers, suggesting a mixed effect on cardiac ion channels.

Control of Listeria monocytogenes growth in a ready-to-eat poultry product using a bacteriophage

A bacteriophage (phage) that infected strains of the species Listeria monocytogenes as well as Listeria ivanovii and Listeria welshimeri, but not Listeria grayi or Listeria innocua, was isolated from sheep faeces. The phage had a contractile tail and an icosohedral head indicating that it was a myovirus, and was morphologically similar to phage A511. At 30 °C, phages added at 5.2 × 10⁷ PFU ml⁻¹ prevented the growth in broth of L. monocytogenes present at approximately twice this concentration for 7 h, but re-growth occurred such that the concentration after 24 h incubation was similar in both control and phage-treated cultures. At the same temperature, but on the surface of vacuum-packed ready-to-eat chicken breast roll, there was an immediate 2.5 log₁₀ CFU cm⁻² reduction in pathogen concentration following addition of phages and then re-growth. However, at a temperature reflecting that at which a chilled food might be held (5 °C), this re-growth was prevented over 21 days incubation. The data suggest a dose-dependent rapid reduction in pathogen concentration followed by no continued phage-mediated effect. These results, alongside other published data, indicate that a high concentration of phages per unit area is required to ensure significant inactivation of target pathogens on food surfaces.

An in-vacuum diffractometer for resonant elastic soft x-ray scattering

We describe the design, construction, and performance of a 4-circle in-vacuum diffractometer for resonant elastic soft x-ray scattering. The diffractometer, installed on the resonant elastic and inelastic x-ray scattering beamline at the Canadian Light Source, includes 9 in-vacuum motions driven by in-vacuum stepper motors and operates in ultra-high vacuum at base pressure of 2 × 10(-10) Torr. Cooling to a base temperature of 18 K is provided with a closed-cycle cryostat. The diffractometer includes a choice of 3 photon detectors: a photodiode, a channeltron, and a 2D sensitive channelplate detector. Along with variable slit and filter options, these detectors are suitable for studying a wide range of phenomena having both weak and strong diffraction signals. Example measurements of diffraction and reflectivity in Nd-doped (La,Sr)(2)CuO(4) and thin film (Ga,Mn)As are shown.