Human fibroblast culture on a crosslinked dermal porcine collagen matrix

The use of a novel porcine-derived collagen biomaterial as a dermal tissue engineering matrix was examined. The matrix is derived from porcine dermis, and is processed to retain the native collagen (Type 1) and elastin structure. Human primary fibroblasts were cultured on the matrix to examine its potential for creating a dermal replacement. Attachment of fibroblasts on the collagen was compared to tissue culture plastic and PET membranes. Cell proliferation was assessed using the MTT assay and DAPI staining. For seeding densities of 5×10⁴ and 1×10⁵ cells cm⁻², PET and plastic demonstrated >95% attachment of seeded numbers after 3 h. The collagen matrix reached levels >80% after 3–4 h with no influence of the seeding density. Matrix samples with perforating pores of 40 μm diameter were also studied. After 216 h culture in static culture, with media replacement every 3 days, the final cell numbers reached 2.1×10⁵ (perforated) and 2.0×10⁵ cells cm⁻² (unperforated). In comparison fibroblast culture in a perfusion bioreactor, with continuous media replacement, reached 2.3×10⁵ (unperforated) and 2.5×10⁵ cells cm⁻² (perforated) after 216 h.     

The presence of serum creatine kinase 2 (MB) in hypokalemic familial periodic paralysis.

We recently found 17 U/l of isoenzyme creatine kinase (CK) 2 (MB), or 3.2% of total 533 U/l CK activity, in a patient with hypokalemic familial periodic paralysis who did not show clinical or EKG evidence of acute myocardial necrosis. The myopathy associated with hypokalemic familial periodic paralysis is thus another cause for the presence of CK 2 (MB). CK 2 (MB) is not a specific isoenzyme for myocardial damage since it may be identified in the serum of patients with skeletal muscle conditions.     

Zonation of late Miocene and early Pliocenecircum-mediterranean faunas

This attempt at biostratigraphic correlations for the fossiliferous sites of the late Miocene and early Pliocene,situated around the Mediterranean basin, is based on the zones established by P. Mein according to variations in the mammalian faunas. New taxa are mentioned, particularly carnivores; moreover, a series of African localities are integrated and, for some of them, an analysis of the faunal constituents leads to paleobiogeographic considerations.     

Enzymatic treatment of primary municipal sludge with Trichoderma viride cellulase

Enzymatic hydrolysis of the cellulose in raw primary settled municipal sludge by Trichoderma viride cellulase achieved conversions of up to 75% of the cellulose, primarily to cellobiose, in 24 hr. Simultaneously the gel-like characteristic of raw primary sludge was changed to that of a slurry of fine particles in less than 2 hr, causing a radical change in the ability to ultrafilter the sludge. The use of raw primary sludge as a growth medium for T. viride cellulase production was also investigated. It was possible, with nitrogen supplements, to obtain an enzyme with a filter paper activity (FPA) of two compared to over four which is attainable on defined medium of similar strength. The potential use of cellulase treatment as a pretreatment or integral part of waste treatment processes is discussed and the alternatives evaluated.