Efficiency of embryotoxicity testing procedures: II. comparison between the official,mest and chest methods

17 drugs were tested by 3 different embryotoxicity methods. The official routine procedure showed interspecies variance even between rat and rabbit. Evaluation based on the reaction of a single morphogenetic system after short-term treatment in the rat (MEST) is less laborious, inexpensive and quicker. Good results were obtained with chick embryos which, under strictly defined experimental conditions (CHEST), may prove a useful and reliable model in embryotoxicity screening.     

Histologic findings in subantral augmentation (sinus lift)

Subantral augmentation (sinus lift) is used to increase alveolar bone mass of lateral maxilla in order to insert dental implants. In addition to the autogenous bone several foreign materials can be used for augmentation and they can replace the autogenous bone to some extent. Histological findings in specimens taken nine months after augmentation with the autogenous bone, deproteinised bovine bone (Bio-Oss) and beta-tricalcium phosphate (Cerasorb) are presented. In all cases a new bone formation around the augmentation material was seen. The new bone was deposited predominantly on its surface. In cases with Cerasorb the new bone formation was observed within the porous granules, too. From the obtained results it can be concluded, that the main osteogenetic mechanism in the examined augmentation materials was osteoconduction. The biocompatibility of the used augmentation materials was evidenced by an absence of giant cell granulomatous reaction and of marked inflammatory infiltrate.     

Late complications of chronic respiratory infections in patients with common variable immunodeficiency

Common variable immunodeficiency (CVID) is the most frequent serious humoral deficiency manifested in adulthood in the form of acute and chronic respiratory infections which in most patients lead to respiratory failure. Retrospective analysis of 28 CVID patients was made. Mean age at time of diagnosis was 38.6 +/- 18.6 years. The time which elapsed from the first symptoms to determining the diagnosis was three times as long as that indicated in other studies, i.e., 14.1 +/- 10.2 years. Twenty-three patients (82.1%) had respiratory complications. Chronic obstructive pulmonary diseases, n=16 (57.1%), and bronchiectasis, n=10 (35.7%), were the most frequent types of lung damage. In addition, two patients (7.1%) displayed evidence of interstitial lung process. Morbidity associated with CVID can be reduced by early diagnosis and adequate dosage of immunoglobulins to minimise the occurrence and progression of lung damage.     

Growth of tick-borne encephalitis virus (European subtype) in cell lines from vector and non-vector ticks

We undertook a comparative study of the susceptibility of different tick cell lines to infection with the European subtype of tick-borne encephalitis virus (TBEV), prototype strain Neudoerfl. The growth of TBEV was investigated in lines derived from vector Ixodes ricinus L. ticks (IRE/CTVM18, 19, and 20), as well as non-vector ticks, namely Ixodes scapularis Say (IDE2), Boophilus microplus Canestrini (BME/CTVM2), Hyalomma anatolicum anatolicum Koch (HAE/CTVM9), Rhipicephalus appendiculatus Neumann (RA-257) and recently established and herein described lines from the argasid tick Ornithodoros moubata Murray (OME/CTVM21 and 22). All the tick cell lines tested were susceptible to infection by TBEV and the virus caused productive infection without any cytopathic effect. However, there was a clear difference between the TBEV growth in vector and non-vector cell lines, since I. ricinus cell lines produced 100-1000-fold higher virus yield than the non-vector cell lines. The lowest virus production was observed in O. moubata and R. appendiculatus cell lines.     

Effect of tick saliva on immune interactions between Borrelia afzelii and murine dendritic cells

Interaction between mouse dendritic cells (DCs) and Borrelia afzelii spirochetes was monitored on three different levels: phagocytosis of spirochetes by DCs, production of cytokines by Borrelia-stimulated DCs and the ability of Borrelia-exposed DCs to activate specific CD4+ T lymphocytes. The effect of Ixodes ricinus tick saliva on each of these interactions was examined. Tick saliva was shown to decrease the number of phagocytosing DCs. The ability of Borrelia-exposed DCs to induce both proliferation and IL-2 production by specific CD4+ T cells was significantly reduced by tick saliva. And surprisingly, we have shown an inhibitory effect of tick saliva on the production of both Th1 (TNF-α and IL-6) and Th2 (IL-10) cytokines by DCs. Our data reveal a complex inhibitory effect of tick saliva on Borrelia-DCs interaction.     

Wound healing gene therapy: cartilage regeneration induced by vascular endothelial growth factor plasmid

Aims

The identification of growth factors and cytokines with angiogenic activity has enabled new therapeutic treatments for a variety of diseases; this concept is called therapeutic angiogenesis. The vascular endothelial growth factor (VEGF) is the most critical regulator of vascular formation. In the present study, we were interested in the therapeutic angiogenesis effect using plasmid transfer of human complementary DNA VEGF₁₆₅ (phVEGF₁₆₅) in experimental skin and cartilage trauma.

Methods

Ten BALB/c mice were used for cartilage injury model. At 6 weeks of age, all mice were ear-punched, resulting in 2-mm-diameter puncture through the center of both pinnae. Each mouse got phVEGF₁₆₅ injection into the first ear and vector without insert or saline injection into the second one. The healing process was followed. The hollow diameter was measured on days 0, 14, and 42. Histological sections of experimental and control pinnae were taken from days 1, 3, 5, 7, 9, 11, 13, 15, 20, and 30 after experimental injury for hematoxylin and eosin and periodic acid Schiff staining and for human VEGF immunocytochemistry. The expression of human VEGF was also checked by real-time polymerase chain reaction in formalin-fixed, paraffin-embedded tissue sections.

Key Findings

In BALB/c mouse strain, a significant angiogenesis promotion and cartilage repair were observed after phVEGF₁₆₅ injection into the punched ear area.

Significance

We suggest that administering phVEGF₁₆₅ leads to faster cartilage regeneration even if not only on the angiogenic basis.     

Changes in immune reactivity in cancer patients

It appears that the long-accepted paradigm that cytostatic and radiation therapy cause only immunosuppression, is not so clearly true. With regard to new knowledge in cancer immunology field, it seems that not only cytostatic and radiation therapy plays an important role in the alteration of immune system. There are many other factors influencing immunity like tumour environment itself, the use of immunomodulatory drugs or even the mental condition of cancer patients. The aim of review is to familiarize physicians with possible alterations of the immune system in cancer patients.