Expression of nonspecific esterase (NSE) by thyroid follicular epithelium as a marker for the target organ susceptibility to immune system attack.

Spontaneous autoimmune thyroiditis in obese strain (OS) chickens provides an excellent animal model for the study of Hashimoto's autoimmune thyroiditis in humans. The data presented in this paper indicate that nonspecific esterases (NSE) may play a role in or serve as a marker for the target organ susceptibility. Experiments have shown that follicular epithelial cells and interfollicular macrophages in connective tissue stain positively for NSE as early as the first day after hatching, a time at which infiltrating lymphocytes are not yet observed. We also have observed NSE positivity of follicular cells in the vicinity of mononuclear cell infiltration in all OS chickens, as well as weaker positivity in 6-month-old, avian leukosis virus free, Brown Leghorn outbred chickens, which appears in each case to correlate with infiltration of lymphocytes. In F2 hybrids between OS and healthy CB inbred chickens, the intensity of NSE staining was more variable than in OS chickens. Using specific inhibitors eserine, Na-taurocholat and p-hydroxymercuribenzoic acid, we were able to inhibit in vitro the NSE positivity of thyroid gland follicular epithelium, indicating that this staining was not an artifact. Experiments are currently in progress to clarify the relationship between the presence of NSE in follicular epithelium and the predisposition to spontaneous autoimmune thyroiditis.

Evidence that growth factors IGF-I, IGF-II and EGF can stimulate nuclear maturation of porcine oocytes via intracellular protein kinase A.

The aim of our in vitro experiments was to study the role of growth factors and protein kinase A (PKA)-dependent intracellular mechanisms in the control of nuclear maturation of porcine oocytes. Oocytes were cultured with or without growth factors (IGF-I, IGF-II, EGF; 10 ng x mL(-1) medium) and inhibitors of PKA (Rp-cAMPS or KT5720; 100 ng x mL(-1)). Stages of meiosis were determined from the structure of chromosomes after staining with Giemza. Intracellular levels of PKA were evaluated immunocytochemically using primary antisera against the PKA regulatory and catalytic subunits and by Western immunoblotting using primary antiserum against the PKA catalytic subunit. It was found that after 24 h culture the majority of oocytes had resumed nuclear maturation (they were at a stage of meiosis after diplotene) and that after 48 h culture the majority of cells had completed maturation (they had reached metaphase II of meiosis). Addition of IGF-I, IGF-II or EGF, or a combination of IGF-I and EGF, significantly increased the proportion of oocytes which resumed and completed meiosis. Immunocytochemistry demonstrated a significant increase in the proportion of cells containing catalytic and, in some cases, the regulatory subunits of PKA after addition of IGF-I, IGF-II and EGF. Immunoblotting showed the presence of 2 forms of the PKA catalytic subunit within the oocytes (MW approximately 52 and 40 kD). EGF, but not IGF-I or IGF-II, increased the content of both isoforms. Inhibitors of PKA, when given alone, did not substantially influence the proportion of oocytes which resumed or completed meiosis. However, Rp-cAMPS and KT5720 both prevented the stimulatory effects of IGF-I, IGF-II and EGF on the resumption and completion of oocyte maturation. The present observations suggest (1) that IGF-I, IGF-II and EGF are potent stimulators of both resumption and completion of porcine oocyte nuclear maturation, (2) that PKA is present in oocytes, and (3) that PKA-dependent intracellular mechanisms can mediate the action of growth factors on porcine oocytes.

Effect of genetic variability of the porcine pituitary-specific transcription factor (PIT-1) on carcas traits in pigs.

Pituitary transcription factor (PIT-1) has been shown to be a positive regulatory factor of growth hormone, prolactin, and thyrotrophin-beta-subunit (TSH-beta) in the mammalian pituitary. Therefore, the gene encoding PIT-1 (POU1F1) was chosen as a candidate gene to investigate its association with growth and carcass traits in pigs. The purpose of this study was to analyse porcine POU1F1 genetic variability in populations of Large White and Large White x landrace pigs, by using PCR-RFLP analysis and to determine its possible associations with two carcass traits (backfat and percentage of lean content). Two different POU1F1-PCR-RFLP (POU1F1/RsaI and POU1F1/MspI) tests were applied to genomic DNA isolated from porcine blood (120 pigs) and hair roots (10 pigs). The present results clearly indicated that the MspI DD genotype was the fattest compared with both other genotypes (CC, CD) in analyzed swine population. For POU1F1/RsaI polymorphism no significance differences were seen for lean-to-fat ratio.

[Disorders of various links in heme synthesis in subjects with occupational exposure to nitrogen oxides]. / Zaburzenia niektórych ogniw syntezy hemu u ludzi zawodowo narazonych na dzialanie tlenkow azotu.

In 35 male subjects with long-standing exposure to low concentrations of nitrogen oxides the morphotic elements of peripheral blood, the activity of delta-aminolaevulinic acid dehydratase(ALA-D) in erythrocytes and urinary elimination of delta-aminolaevulinic acid (ALA), coproporphyrin (CP) and porphobilinogen (PBG) were determined. The control group comprised 29 healthy men not exposed to toxic substances. Statistically significant methaemoglobinaemia, decreased heamoglobin concentration and reduced mean heamoglobin weight in erythrocytes were found in the exposed subjects. At the same time the activity of ALA-D in erythrocytes was increased and urinary elimination of coproporphyrin was increased while that of ALA was decreased. Decreased haemoglobin concentration in peripheral blood in cases of chronic exposure to nitrogen oxides may depend on their effect on the enzymes participating in haeme synthesis. However, increased ALA-D activity in erythrocytes found in these cases may be of some importance in evaluation of exposure to nitrogen oxides.

[Non-specific immunity of persons exposed to contaminants emitted by nitrogen plants]. / Ocena odpornosci nieswoistej ludzi narazonych na zaniecyzyszczenai emitowane przez zaklady azotowe

The examinations of methemoglobin and properdine levels as well as of the function of peripheral blood leukocytes in the tetranitrozolic blue reduction test (NBT) were performed in the exposed persons. The obtained results were compared with those of the control group, using statistical methods. It has been found that in persons exposed to the emitted contaminants occurs the increase of methemoglobin level, the decrease of peoperdine level and a disturbed phagocytes function. The recorded changes in the factors of nonspecific immunology, i.e. of properdine and phagocytes, can favour the development of inflammatory processes and of nonspecific diseases of the respiratory system.