Gas chromatographic analysis, coupled to mass spectrometry, demonstrates that the considerable amounts of ecdysteroids produced in the ovaries of female adults of Locusta migratoria at the end of each ovarian cycle, consist predominantly of ecdysone.

Age Factors↗

PubMed1976

[Variations in the level of molting hormone during the second cycle of embryonic life in cockroaches].

It was shown by gas chromatography/mass fragmentography and radio-immunology that moulting hormone is present in great quantity during the second cycle of the embryonic life of Blabera and that the hormone concentration changes during this cycle. The loss of the regenerative capacity corresponds to a beta-ecdysone peak.

Age Factors↗

PubMed1976

[Ecdysteroid levels and ovarian development in adult female Locust migratoria].

During ovarian development in adult females of Locusta, an important biosynthesis of ecdysteroids is observed at the end of the maturation process of the terminal oocyte. This phenomenon occurs regularly during the different ovarian cycles. No synthesis is observed in allatectomized or ovariectomized female adults.

Adipose Tissue↗

PubMedDate not supplied

Identification and immunolocalization by monoclonal antibody of NSP-5, a surface polypeptide of neural cells.

A monoclonal antibody, termed anti-NSP-5 (anti-Neural cell Surface Protein-5) was obtained from an hybridoma generated by fusing rat myeloma cells with splenocytes of a rat immunized with membranes from the cerebella of weaver mutant mice. This antibody reacted with the surface membrane of a subset of neurones in cultures from cerebella and dorsal root ganglia. In both culture systems, only tetanus toxin-positive cells were stained by the antibody. In sections of adult cerebellum a punctate pattern of staining was seen in the molecular layer, the Purkinje cell layer and the upper part of the granule cell layer. The white matter was strongly positive whereas granule cell and Purkinje cell bodies were clearly negative. In sections from adult dorsal root ganglia anti-NSP-5 labeled most sensory neurones including their axones in the dorsal roots. The expression of the antigen was developmentally regulated. It could not be detected in cerebellar cultures prepared from animals younger than 7 days, in good agreement with the data obtained on tissue sections. Similarly, the antigen could not be detected by immunoblotting in neonatal spinal cord, but a NSP-5-reactive band was present at postnatal day 7. The antibody bound a polypeptide of around MW 180 000 in extracts prepared from adult mouse spinal cord or cerebellum. When purified by immunoaffinity chromatography the antigen co-eluted with numerous strongly associated polypeptides. Upon subcellular fractionation most of it remained associated with a Triton-X100 insoluble fraction thus co-distributing with the cytoskeleton.

Animals↗

PubMedDate not supplied

Adult and embryonic mouse neural cell adhesion molecules have different binding properties.

Interactions between neural cell surfaces seem to be of prime importance during neuroontogenesis, and responsible for the guidance of migrating neuroblasts and growing axons and for the formation of synapses. Little is known about the underlying molecular mechanisms, but most hypotheses imply the existence of cell-surface molecules that mediate the formation of transient or permanent bonds between neural cells. Recently, a membrane glycoprotein called neural cell adhesion molecule (N-CAM) has been characterized in chick and rodent nervous tissue that appears to act as a ligand in adhesion among neural cell bodies or neurites. We have identified a mouse neural surface glycoprotein, named BSP-2 (ref. 7), which by criteriaof electrophoretic migration, developmental changes, amino acid and sugar composition seems to be closely related or identical to N-CAM. Both BSP-2 (refs 8, 9) and N-CAM undergo conversion from an embryonic to an adult form during brain development and it has been suggested that this transition changes the adhesive properties or the binding specificity of the molecule. Using a neuroblastoma line to study functional differences between embryonic and adult BSP-2/N-CAM molecules, we show here that liposomes bearing adult BSP-2 but not those bearing the embryonic form adhere to neuroblastoma cells, demonstrating that the two forms do indeed possess different binding properties.

Animals↗

PubMedDate not supplied

Survival of 25 osteoarticular allografts followed more than 10 years.

An evaluation of the long-term survival rate of 25 osteoarticular allografts was made. Clinical analysis was based on the Mankin scale and the Musculoskeletal Tumor Society (MSTS) Grading system. After a mean follow-up time of 15 years 76% of the osteoarticular allografts had good or excellent rating. The MSTS scale revealed a mean score of 89% for those 20 grafts still functioning according to their primary purpose. Allograft related complications occurred in 32% of the cases being most common among malignant cases. Due to the rather good long-term results, osteoarticular allografts can still be recommended for hemicondylar allograft reconstruction in benign lesions.

Adult↗

PubMedDate not supplied

Pulse lavage washing in decontamination of allografts improves safety.

We analyzed the bacterial contamination rate of 140 femoral head allografts after rinsing the allografts in different decontamination solutions. Bacterial screening methods and cleansing effect of antibiotics (cefuroxime and rifampicin) and pulse lavage were compared. Swabbing and taking small pieces of bone for culture were the screening methods used. Both methods proved to be quite unreliable. Approximately one-fourth of the results were false negative. Culturing small pieces of bone gave the most accurate and reliable results and, therefore, can be recommended as a bacterial screening method. The use of antibiotics in allograft decontamination is controversial. In prophylactic use antibiotics include risks of allergic reactions and resistant development and our results in the present study show that antibiotics do not improve the decontamination any better than low-pressure pulse lavage with sterile saline solution. Therefore, pulse lavage with sterile saline solution can be recommended for allograft decontamination. Our results demonstrate that it decreases bacterial bioburden as effectively as the antibiotics without persisting the disadvantages.

Bacterial Infections↗