Liliane Barr-Nea

Spinal cord response to laser treatment of injured peripheral nerve.

The authors describe the changes occurring in the spinal cord of rats subjected to crush injury of the sciatic nerve followed by low-power laser irradiation of the injured nerve. Such laser treatment of the crushed peripheral nerve has been found to mitigate the degenerative changes in the corresponding neurons of the spinal cord and induce proliferation of neuroglia both in astrocytes and oligodendrocytes. This suggests a higher metabolism in neurons and a better ability for myelin production under the influence of laser treatment.

The venom apparatus of Vespa orientalis: Morphology and cytology

Abstract The anatomy and histology of the venom apparatus of Vespa orientalis has been investigated. There are two acid glands per hornet each divided into a secretory part made up of two layers of cells containing large amounts of lipids and mucopolysaccharides, and a ‘transporting’ part through which the substances secreted are transported into the venom sac. The alkaline gland contains one layer of cells; muscle fibers are connected to these cells externally and probably play a role in the transport of the secreted substances into the stinging apparatus. The venom sac serves as a reservoir for the secretion of the acid gland and is made of a thick layer of muscle fibers. The toxicity of the different parts of the venom apparatus has been studied both by in vivo and in vitro methods. Extracts of acid and alkaline glands and of venom sac were injected into bees and mice. All the extracts were lethal for the bees, all the extracts were toxic for the mice but only an amount of 4500–7500 μg of venom sac extract was lethal for the mice. The different extracts applied to cultures of liver cells produced an accumulation of fat within the cells, which is considered as a toxic change of the cells.

Cell-mediated immunity following experimental vaccinations with Candida albicans ribosomes

The aim of the present study was to ascertain whether cell-mediated immunity (CMI) is induced in animals by vaccination with Candida albicans ribosomes. Delayed type hypersensitivity (DTH) was detected in vivo in ribosome-vaccinated mice and guinea pigs by the footpad swelling and skin tests, respectively. The observed DTH was similar to that induced by live C. albicans organisms. A lymphocyte transformation assay was used for in vitro detection of CMI. The tritiated thymidine incorporation assays revealed that spleen lymphocytes from mice immunized with C. albicans ribosomes were stimulated by the ribosomal antigen. The findings establish that C. albicans ribosomes are able to induce CMI in experimental animals.

New Methods of Treatment of Severely Injured Sciatic Nerve and Spinal Cord

It has been demonstrated that low-energy laser irradiation (LELI) applied simultaneously to the injured sciatic nerve and the corresponding segment of the spinal cord, accelerates the process of regeneration of the injured peripheral nerve. A beneficial influence of LELI was also observed when it was applied to the spinal cord following transection and implantation of a segment of an autologous sciatic nerve, but further studies are necessary to evaluate if real regeneration or only earlier distal cord automatism occurred.

Systemic candidiasis in mice immunized with Candida albicans ribosomes

In view of our previous findings that vaccination of mice with Candida albicans ribosomes protects them against experimental systemic candidiasis, the aim of this study was to investigate the effect of this vaccination on the course of infection in immunized animals. Since the kidney is the maj or target in systemic candidal infection, we concentrated in this research on studying the histopathology and determining quantitatively the candidal colonization of this organ. The experiments were carried out at various time intervals after intravenous inoculation with live C. albicans. The colonization of kidneys in immunized mice was markedly lower than that in controls. The maximal difference in renal colonization between immunized and non immunized animals was observed when relatively low challenge doses were used. The inhibition of candidal multiplication in immunized mice seemed to be correlated to their increased resistance against lethal challenge, as expressed by a significantly higher survival rate. Histopathological changes and fungal elements were found in kidneys of control mice as early as 20 h post infection, while the kidneys of immunized mice did not seem affected by the disease. Moreover, even 3 days post infection, the kidneys of vaccinated animals still seemed normal. In conclusion, apparently the ribosomal vaccination leads to diminished colonization of the major site of infection in candidiasis, thus affording protection to the immunized animals against these infections.

Protection against systemic infections with various Candida species elicited by vaccination with Candida albicans ribosomes

This study investigated whether subcutaneous vaccination of mice with ribosomes from Candida albicans strain CBS 562 would also provide protection against infections by other isolates of Candida. Experiments with a total of 628 mice demonstrated that vaccination induced significant protection against heterologous C. albicans (serotypes A and B) and C. tropicalis isolates in terms of their 30 day survival rates. In all instances, however, protection was lower than that obtained against the homologous strain. In addition, a significant decrease in fungal colonization of the kidneys was found in immunized animals as compared to the non immunized controls. Cell-mediated immune responses against cytoplasmic extracts of the various fungi, as detected in vivo by the foot pad swelling test and in vitro by the lymphocyte transformation assay, were induced by the C. albicans ribosomal vaccination. The results show it is possible to induce cross protection to various Candida species by immunization with C. albicans ribosomes.

Histopathological changes in mouse and rat skin injected with venom sac extracts of the oriental hornet (Vespa orientalis)

Abstract ICR white and C57 black mice and Charles Rivers rats were injected intradermally with a dialysed extract of venom sac of the Oriental hornet. Changes were observed throughout the skin. The epidermis underwent hyperplasia and hairless patches and depigmentation were observed in black mice. Acute inflammation spread throughout the dermis, evolving into a chronic form. The muscle fibers showed degeneration. The extent of the changes was dependent upon the species involved: the C57 black mice were the most affected and the rats the least.

Induction of protection against candidiasis in tumor-bearing mice by vaccination with Candida albicans ribosomes

The aim of this study was to determine whether vaccination of tumor-bearing mice with ribosomes of Candida albicans would result in the induction of protective immunity. Therefore, (BB)F1 mice were inoculated intraperitoneally with the thymoma, EL-4, then immunized with ribosomes purified from C. albicans, and challenged intravenously with C. albicans to assess the protective response. Unimmunized mice, both normal and tumor-bearing, treated in the same manner served as controls. Both normal and tumor-bearing mice developed protective immunity in response to immunization with ribosomes. The protected mice had fewer colony-forming units in their kidneys 3 days after intravenous challenge than the unimmunized control animals, regardless of tumor status. Moreover, all unimmunized mice, tumor-bearing and normal, developed delayed hypersensitivity to the ribosomes, as well as ribosome-specific antibody, both of which were of the same order of magnitude. Therefore, the EL-4 thymoma does not suppress the immune system of mice, and they are capable of responding immunologically in a normal manner to C. albicans.

Effects of hypergravity on rat fertility, pregnancy, parturition and survival

Persistent centrifugation (at 1.18×g to 1.47×g) of pregnant rats reduced the number of deliveries and the survival time of the newborns. The extent of the damage increased with increasing distance from the axis. Male fertility was reduced.

Hypergravity: its effect on the estrous cycle of rats.

Hypergravity affects the estrous cycle of rats. It is prolonged by a force of 1.39G–1.65G, and shows irregularities between 1.02 and 1.19G. Rats centrifuged for 40 days and returned to normal gravity presented a normal estrous pattern.