Allorecognition in the Tasmanian Devil (Sarcophilus harrisii), an Endangered Marsupial Species with Limited Genetic Diversity

Tasmanian devils (Sarcophilus harrisii) are on the verge of extinction due to a transmissible cancer, devil facial tumour disease (DFTD). This tumour is an allograft that is transmitted between individuals without immune recognition of the tumour cells. The mechanism to explain this lack of immune recognition and acceptance is not well understood. It has been hypothesized that lack of genetic diversity at the Major Histocompatibility Complex (MHC) allowed the tumour cells to grow in genetically similar hosts without evoking an immune response to alloantigens. We conducted mixed lymphocyte reactions and skin grafts to measure functional MHC diversity in the Tasmanian devil population. The limited MHC diversity was sufficient to produce measurable mixed lymphocyte reactions. There was a wide range of responses, from low or no reaction to relatively strong responses. The highest responses occurred when lymphocytes from devils from the east of Tasmania were mixed with lymphocytes from devils from the west of Tasmania. All of the five successful skin allografts were rejected within 14 days after surgery, even though little or no MHC I and II mismatches were found. Extensive T-cell infiltration characterised the immune rejection. We conclude that Tasmanian devils are capable of allogeneic rejection. Consequently, a lack of functional allorecognition mechanisms in the devil population does not explain the transmission of a contagious cancer

Cyclic AMP and cyclic GMP concentrations in serum- and density-restricted fibroblast cultures.

Mouse fibroblasts transformed by simian virus 40 (SV3T3 cells) are characterized by cyclic AMP and cyclic GMP levels, respectively, about half and twice those found in growing untransformed 3T3 cells. Density-dependent inhibition of growth is correlated with reduced cyclic GMP concentrations in 3T3 and four different density-restricted revertant lines derived from SV3T3. The levels of cyclic AMP are not increased at confluence. Upon serum restriction, serum-dependent cell lines show a greater increase in intracellular cAMP than serum-insensitive lines. Cyclic GMP levels are greatly reduced, even in serum-insensitive density revertants, but not in SV3T3. Serum readdition to all serum-dependent lines is followed by a rapid decrease in cyclic AMP and increase in cyclic GMP concentrations. The magnitude of these responses is decreased in SV3T3 and density revertants

THYMOME ET GROSSESSE. A PROPOS D'UN CAS

A case of thymoma associated with pregnancy is reported. This association is extremely rare (8 described cases) and the clinical outcome is most frequently unfavorable for the mother. The diagnosis was made by a standard chest X-ray performed routinely post-partum. Sixteen months after total surgical extirpation of the tumor and adjunctive radiotherapy the patient is still in complete remission. The presented case is discussed with reference to a review of the literature.SCOPUS: ar.jinfo:eu-repo/semantics/publishe

Antiphospholipid antibodies and ischemic neuropathy following cardiac surgery.

Sciatic nerve palsy is an uncommon complication of cardiac surgery and is thought to be induced by a combination of reduced femoral artery blood flow, small vessel vascular disease or prolonged hypoxia. We here describe a new case which is the first described with transient elevation of antiphospholipid antibodies. Although transient elevation of lupus coagulation inhibitor is known to occur frequently in patients treated in an intensive care unit, there are very few data about the possible role of antiphospholipid antibodies in the generation of ischemic neuropathies. We can not prove that the ischemic neuropathy in our case has been favored by the presence of lupus coagulation inhibitor and antiphospholipid antibodies as the occurrence of the symptoms seemed to precede the transient elevation of lupus coagulation inhibitor. This case suggests that antiphospholipid antibodies and lupus coagulation inhibitor should be included in the work up of patients who present nerve damage after cardiac surgery but further studies are needed to ascertain this association.Case ReportsJournal Articleinfo:eu-repo/semantics/publishe

Lupus coagulation inhibitor associated neuropathy following cardiac surgery

info:eu-repo/semantics/nonPublishe

Ploidy and chromatin pattern analysis as an aid for cervical smear diagnosis

In the present study we used computerassisted microscopy to analyze the morphology of Feulgen-stained cell nuclei in cell populations obtained at the same time as routinely performed cervical smears and in the same way. We investigated in a series of 110 cases whether the quantitative morphonuclear description of cytological cervical samples is able to aid pathologists to distinguish between benign and more suspect premalignant lesions. For this task nuclear DNA content, nuclear morphometry (size and anisonucleosis l evel) and chromatin pattern-related parameters were compiled for each specimen enrolled in the database. A set of 32 normal and 17 high-grade squamous intraepithelial lesion (HSIL) specimens (with diagnostic c o n firmations) were selected as references and used to establish a discriminant model on the basis of cytometrygenerated variables. This model was then used to score the remaining 61 cases in our series (including cases exhibiting benign cellular changes, squamous cells of undetermined significance, low-grade SIL and cancers). The results show that a model discriminating efficiently between normal and HSIL groups can be obtained by combining 5 quantitative features (1 DNA ploidyrelated, 2 morphometrical and 2 chromatin tex t u r e features). A 97% specificity and an 88% sensitiv i t y characterized the boundary so established. When applied to new cases, the model was in fact able to correct diagnoses for cases which had been down- or up-graded on the basis of the Bethesda system, and provided scores in accordance with histological control