Low molecular weight heparin prophylaxis in day case surgery

Background  

The role of Low molecular weight heparins (LAAWH) in day case/ short-stay surgery is unknown.     

Stable L-Forms of Clostridium perfringens: Growth, Toxin Production, and Pathogenicity

Growth and toxin production of stable L-forms of Clostridium perfringens grown in a mini-fermentor were monitored. A gradual but steady increment in viable count occurred over a 7-h period, followed by death. The peak of viability preceded the optical density peak by 3 h. Theta, alpha, kappa, and lambda toxins were measured, with theta toxin appearing first in the culture supernate. Growth of the parent bacillus form of C. perfringens was compared under similar conditions. Toxin levels achieved by the bacillus culture exceeded those of the L-form culture four- to eightfold; however, based upon viable count, the L-form organism produced 8 to 16 times as much toxin as did the bacillus. The amounts of extracellular toxin produced by both forms were similar when related to cell protein rather than cell number. Guinea pig inoculation showed that the L-form of C. perfringens did not produce gas gangrene, although it was not entirely without effect. Both guinea pig and human sera were inhibitory to these L-forms, a fact attributable to a heat-liable component in the sera, most likely complement.     

Evaluation of semen parameters by means of automated sperm motion analyzers

Fresh semen specimens from 46 patients and donors were evaluated for concentration, motility, velocity, and linearity using two different commercially available computerized sperm motion analyzer systems. Although no significant differences in measurement of concentration or motility were observed, significant differences in velocity and linearity were recorded. Fourteen cryopreserved/thawed samples were assessed with the same set-up parameters as fresh specimens. When discrepancies between manual and computer counts were noted, the authors changed the set-up parameters and evaluated 33 additional specimens. Again, no differences in concentration and motility, but significant differences in velocity and linearity were observed. Interlaboratory results must be correlated and standardization of set-up parameters of various analyzers is essential.     

How we got from there to here and back

Edward H. Angle dominated orthodontic armamentarium, diagnosis and treatment planning for almost a half century until Charles Tweed successfully challenged his mentor's nonextraction mantra. The ensuing diagnostic regimen used by Tweed, however, proved to have serious limitations and clearly resulted in the extraction of too many teeth. This caused a subsequent deterioration of soft tissue appearances of patients that neither they nor their doctors liked. This article will describe and illustrate how new expansion techniques differ qualitatively from those of Angle, and how these techniques offer patients and doctors less invasive and more comfortable therapies which do not jeopardize facial appearances.     

In Vitro Investigations of the Efficacy of Cyclodextrin-siRNA Complexes Modified with Lipid-PEG-Octaarginine: Towards a Formulation Strategy for Non-viral Neuronal siRNA Delivery

Purpose

Development of RNA interference based therapeutics for neurological and neurodegenerative diseases is hindered by a lack of non-viral vectors with suitable properties for systemic administration. Amphiphilic and cationic cyclodextrins (CD) offer potential for neuronal siRNA delivery. We aimed to improve our CD-based siRNA formulation through incorporation of a polyethyleneglycol (PEG) shielding layer and a cell penetrating peptide, octaarginine (R8).

Methods

CD.siRNA complexes were modified by addition of an R8-PEG-lipid conjugate. Physical properties including size, charge and stability were assessed. Flow cytometry was used to determine uptake levels in a neuronal cell model. Knockdown of an exogenous gene and an endogenous housekeeping gene were used to assess gene silencing abilities.

Results

CD.siRNA complexes modified with R8-PEG-lipid exhibited a lower surface charge and greater stability to a salt-containing environment. Neuronal uptake was increased and significant reductions in the levels of two target genes were achieved with the new formulation. However, the PEG layer was not sufficient to protect against serum-induced aggregation.

Conclusions

The R8-PEG-lipid-CD.siRNA formulation displayed enhanced salt-stability due to the PEG component, while the R8 component facilitated transfection of neuronal cells and efficient gene silencing. Further improvements will be investigated in the future in order to optimise stability in serum and enhance neuronal specificity.