Effects of Δ8- and Δ9-Tetrahydrocannabinol on experimentally induced seizures

Effects of Δ⁸- and Δ⁹-tetrahydrocannabinol (Δ⁸- and Δ⁹-THC) on three experimentally induced seizure models, i.e., audiogenic seizure (AS) test, maximal electroshock seizure (MES) test and pentylenetetrazol (PTZ)-induced seizure test were determined in the audiogenic rat. Both tetrahydrocannabinols possess a dose-related anticonvulsant effect against AS, MES and PTZ-induced maximal seizure. Although anticonvulsant potencies do not significantly differ, Δ⁸THC is three times more neurotoxic than Δ⁹THC. In addition, both THC's are without effect on minimal seizure and lethality induced by PTZ. Furthermore, the low protective indexes (TD50/ED50) determined in this study suggest that Δ⁸ and Δ⁹ THC may have poor therapeutic potentials as antiepileptic drugs.     

Lymphotoxin is expressed as a heteromeric complex with a distinct 33-kDa glycoprotein on the surface of an activated human T cell hybridoma.

We characterized the membrane-associated form of lymphotoxin (surface LT) on the activated II-23.D7 T cell hybridoma. Antibodies to rLT precipitated both surface LT and a distinct 33-kDa glycoprotein (p33). Because p33 and surface LT were antigenically unrelated, their coprecipitation suggested a physical association of p33 and surface LT on the membrane. Pulse-chase analysis indicated that LT and p33 associate with each other early in the LT biosynthetic pathway, precluding the possibility that LT is secreted and bound to p33 or a surface receptor. Furthermore, no p33 was associated with the secreted form of LT. Isoelectric focusing of surface LT and p33 under nondenaturing and denaturing conditions confirmed that surface LT and p33 existed as a complex. Treatment of cells with a high concentration of salt or with acid indicated that surface LT is a peripheral membrane protein. Although secreted LT is a homologous trimer, protein cross-linking studies revealed that surface LT existed as a monomer associated with a dimer of p33. Together the results demonstrate a novel mechanism for stable membrane expression of LT by activated T cells.     

Evidence of hexaploid karyotype in shortnose sturgeon

A karyotype analysis by several staining techniques was carried out on triplicate samples of the shortnose sturgeon, Acipenser brevirostrum. The chromosome number was found to be 2n = 372 +/- 6. A representative karyotype of 374 chromosomes was composed of 178 metacentrics/submetacentrics and 196 telocentrics/acrocentrics and microchromosomes. The signals of fluorescent in situ hybridization (FISH) with a HindIII satellite DNA probe were visible on 14 chromosomes. The signals obtained with a PstI satellite DNA probe appeared on 12 chromosomes. The FISH with a 5S rDNA probe revealed fluorescent signals on 6 chromosomes. These last results, compared with 2 signals in species with about 120 chromosomes and 4 in species with 240, support the hypothesis that A. brevirostrum is a hexaploid species, probably of hybrid origin. Based on these results, we propose a model explaining speciation events occurring in sturgeons by hybridization, genome duplication, and diploidization.     

The anal sac secretion of the red fox (Vulpes vulpes); its chemistry and microbiology. A comparison with the anal sac secretion of the lion (Panthera leo)

Phenylacetic, 3-phenylpropionic, $\text{p}$-hydroxyphenylacetic and 3 ($\text{p}$-hydroxyphenyl) propionic acids together with the series of C₂ to C₆ saturated fatty acids previously reported in the anal sac secretion of the red fox ($\text{Vulpes vulpes}$) are identified as constituents of the anal sac secretion of the lion (Panthera leo). All these compounds are also observed in the anal sac secretion of the red fox using gas chromatography. The aerobic microflora of red fox and domestic dog ($\text{Canis familiaris}$) anal sac secretion samples invariably consisted predominantly of $\text{Streptococcus faecium}$ and $\text{Streptococcus faecalis}$. The hypothesis that the secretion volatiles so far identified may be microbiologically produced is examined.     

Impact of the long chain ω-acylceramides on the stratum corneum lipid nanostructure. Part 1: Thermotropic phase behaviour of CER[EOS] and CER[EOP] studied using X-ray powder diffraction and FT-Raman spectroscopy

The stratum corneum (SC), the outermost layer of the mammalian skin, is the main skin barrier. Ceramides (CERs) as the major constituent of the SC lipid matrix are of particular interest. At the moment, 11 classes of CERs are identified, but the effect of each single ceramide species is still not known.Therefore in this article, the thermotropic behaviour of the long chain ω-acylceramides CER[EOS] and CER[EOP] was studied using X-ray powder diffraction and FT-Raman spectroscopy.It was found that the ω-acylceramides CER[EOS] and CER[EOP] do not show a pronounced polymorphism which is observed for shorter chain ceramides as a significant feature. The phase behaviour of both ceramides is strongly influenced by the extremely long acyl-chain residue. The latter has a much stronger influence compared with the structure of the polar head group, which is discussed as extremely important for the appearance of a rich polymorphism. Despite the strong influence of the long chain, the additional OH-group of the phyto-sphingosine type CER[EOP] influences the lamellar repeat distance and the chain packing. The less polar sphingosine type CER[EOS] is stronger influenced by the long acyl-chain residue. Hydration is necessary for the formation of an extended hydrogen-bonding network between the polar head groups leading to the appearance of a long-periodicity phase (LPP). In contrast, the more polar CER[EOP] forms the LPP with densely packed alkyl chains already in the dry state.