Inhibition of atherosclerosis by the serine palmitoyl transferase inhibitor myriocin is associated with reduced plasma glycosphingolipid concentration

Glycosphingolipids (GSL) have been implicated as potential atherogenic lipids. Inhibition of hepatic serine palmitoyl transferase (SPT) reduces plasma sphingomyelin (SM) levels in the absence of changes in cholesterol or triglyceride (TG) concentration and this leads to a reduction of atherosclerosis in apolipoprotein-E gene knockout (apoE(-/-)) mice. The possibility that the reduced atherosclerosis resulting from SPT inhibition is associated with decreases in plasma GSL concentration has not been examined and was the primary aim of this investigation. We show that intraperitoneal delivery of the SPT inhibitor myriocin for 9 weeks inhibits atherosclerosis in apoE(-/-) mice fed a high fat diet. Lesion inhibition was most pronounced at the aortic arch and distal sites of the thoracic and abdominal aorta. There was also a trend towards a reduction in lesion area at the aortic root. Myriocin treatment resulted in significant reductions in both plasma SM and GSL concentration of 42% and 25%, as assessed by enzymatic and HPLC methods, respectively. Moreover, SM and GSL concentrations were significantly correlated, indicating that SPT inhibition suppresses the synthesis of both these sphingolipids concomitantly. The inhibition of atherosclerosis induced by myriocin was not associated with changes in plasma cholesterol or TG concentrations or lipoprotein profiles as determined by FPLC. These data indicate that therapeutic reduction of plasma SM and/or GSL concentrations may offer a novel treatment for atherosclerosis.     

Acute morphological sequelae of photodynamic therapy with 5-aminolevulinic acid in the C6 spheroid model

Objective Aminolevulinic acid (ALA)-mediated photodynamic therapy (PDT) may represent a treatment option for malignant brain tumors. We used a three-dimensional cell culture system, the C6 glioma spheroid model, to study acute effects of PDT and how they might be influenced by treatment conditions. Methods Spheroids were incubated for 4 h in 100 μg/ml ALA in 5% CO₂ in room air or 95% O₂ with subsequent irradiation using a diode laser (λ = 635 nm, 40 mW/cm², total fluence 25 J/cm²). Control groups were “laser only”, “ALA only”, and “no drug no light”. Annexin V-FITC, a marker used for detection of apoptosis, propidium iodide (PI), a marker for necrotic cells and H 33342, a chromatin stain, were used for morphological characterization of PDT effects by confocal laser scanning and fluorescence microscopy. Hematoxylin–eosin staining and TdT-FragEL (TUNEL) assay were used on cryosections. Growth kinetics were followed for 8 days after PDT. Results PDT after incubation in 5% CO₂ provided incomplete cell death and growth delay in spheroids of >350 μm diameter. However, complete cell death and growth arrest occurred in smaller spheroids (<350 μm). Incubation in 95% O₂ with subsequent PDT resulted in complete cell death and growth arrest regardless of spheroid size. In incompletely damaged spheroids viable cells were restricted to spheroid centers. The rate of cell death in all control groups was negligible. Cell death was accompanied by annexin/PI costaining, but there was also evidence for annexin V-FITC staining without PI uptake. Conclusions PDT of experimental glioma results in rapid and significant cell death that could be verified as acute necrosis immediately after irradiation. This effect depended on O₂ concentration and spheroid size.     

Protection against experimental fowl typhoid by parenteral administration of live SL5828, an aroA-serC (aromatic dependent) mutant of a wild-type Salmonella Gallinarum strain made lysogenic for P22 sie

A wild-type strain of Salmonella enterica serotype Gallinarum, lysogenized with P22 sie (superinfection-exclusion defective) was greatly attenuated for newly hatched or 21-day-old chickens. An aroA transductant of the lysogenic strain and an aroA-serC tetracycline-sensitive deletion or deletioninversion mutant of the latter were equally attenuated. Intramuscular administration of the aroA-serC strain to 21-day-old chickens protected them against oral challenge with 10⁶ colony forming units of a highly virulent Gallinarum strain (no deaths in the 30 vaccinated chickens versus 14 of 30 in the control group). There was evidence of protection in the contents, mucosa and lymphoid tissue of the alimentary tract, in addition to that which occurred in the liver and spleen.A weak serological response was detected by enzyme-linked immunosorbent assay, indicating that use of such a strain is compatible with serological monitoring and would be a useful adjunct to control schemes for fowl typhoid.     

Validity and limits of intraoperative parathyroid hormone monitoring during minimally invasive parathyroidectomy: a 10-year experience

Background  

The availability of intraoperative intact parathyroid hormone monitoring allows the success of minimally invasive parathyroidectomy to be ensured during the operation. However, false-negative results leading to unnecessary explorations and difficulties in interpreting the data raise concern about the effectiveness of the method.     

Genetic manipulation of Salmonella serotype Bovismorbificans to aromatic-dependence and evaluation of its vaccine potential in mice

The generation of smooth aromatic-dependent Salmonella serotype Bovismorbificans (Group C2, O6, 8) from a smooth wild-type parent strain by transduction with phage P1, and conjugation with Salmonella serotype Typhimurium carrying F'-8gal is described. The smooth aromatic-dependent S. serotype Bovismorbificans was non-lethal for mice at an oral challenge dose of 2 x 10(9) cfu (equivalent to 200 LD50 of the parent, wild-type strain). The safety of the auxotrophic mutant was further substantiated by comparing its multiplication kinetics in vivo with that of its virulent parent organisms. Mice immunised with live, smooth aromatic-dependent S. serotype Bovismorbificans by either the oral or intraperitoneal (i.p.) route were protected against oral challenge with virulent S. serotype Bovismorbificans; the degree of protection was significantly better (p less than 0.05) at a challenge dose of 100 or 200 LD50 in mice receiving two rather than one vaccination. In contrast, mice immunised with three doses of the formalin-killed virulent, parent organisms by the i.p. route were not protected, in spite of high antibody titres. Only those mice immunised with the live, smooth aromatic-dependent S. serotype Bovismorbificans i.p. developed significant (p less than 0.01-0.05) delayed-type hypersensitivity.     

A Pig Collagen Peptide Fraction. A Unique Material for Maintaining Biological Activity During Lyophilization and During Storage in the Liquid State

There is frequent use of human and animal proteins as stabilizers during lyophilization of a variety of biological substances with a view to long term stable storage. This report describes the comparative excellent stabilizing effect of a porcine collagen peptide fraction (CPF) during the lyophilization and subsequent storage of three commonly used biological substances, alkaline phosphatase, tissue plasminogen activator and thrombin. The CPF was heated to 150°C for one hour before use. The CPF was shown to have some advantage during lyophilized storage over human serum albumin. Solutions of thrombin stored in CPF at room temperature and at 37°C for one week retained nearly all activity, while storage of thrombin in human serum albumin solution at 37°C lost nearly all biological activity. These preliminary data suggest that porcine CPF is a safe and advantageous stabilizer for addition to biological products with a view to long-term lyophilized storage and short-term liquid storage.     

Audit for the Heartbeat Award in staff catering facilities in an NHS Trust

Background: The Heartbeat Award Scheme (HBA) is a national initiative whereby caterers receive an award for meeting identified minimum criteria related to healthy menu choices, food hygiene and eating environment. The eligibility of four staff catering facilities in an NHS Trust was assessed by audit. Methods: An audit tool was developed which enabled comparison between food displayed and itemized on the menu board and HBA criteria for each food category. It also contained questions about food preparation and ingredients. The catering facilities were audited on five different weekdays during a 2-week period (seven for one facility). Observations were recorded about visibility, appearance and plate wastage. Results: Usually it was clear whether food served achieved HBA criteria, but development of quantified criteria were necessary for reliable assessment of main dishes, sandwiches and desserts. A summary of the key findings are presented, including achievement of HBA criteria, together with the resulting recommendations, observations and identification of issues arising from the audit. Conclusion: The benefits of this approach outweigh any drawbacks and include the ability to facilitate assessment for the HBA in the absence of written menus, obtain baseline information, enable repeated audit and provide details to support recommendations made to caterers. The audit tool has now been included as part of the contract specification for the local purchasing commission.