Peroxynitrite-mediated modification of fibrinogen affects platelet aggregation and adhesion

The reaction of peroxynitrite with fibrinogen resulted in both structural modifications and altered biological properties of this glycoprotein. SDS-PAGE analysis of peroxynitrite-treated fibrinogen, performed under non-reducing conditions, showed some aggregated material on the top of the gel (5-10% of total staining bands) and the presence of nitrotyrosine. The amount of nitrotyrosine, detected by immunoassay with anti-nitrotyrosine antibodies, was dependent on peroxynitrite concentration. In comparison with native molecule, peroxynitrite-treated fibrinogen subjected to SDS-PAGE under reducing conditions revealed not only three bands corresponding to A f , B g and n chains, but the existence of additional high molecular bands probably due to the formation of dityrosine crosslinking between fibrinogen subunits. The different susceptibility in tyrosine nitration of fibrinogen subunits was also observed. The A f chain was the most intensely nitrated, while B g and n chains were nitrated much less? Peroxynitrite-treated fibrinogen in comparison with native molecule had a distinct capability to mediate platelet adhesion and aggregation. Both unstimulated and ADP-activated platelets showed a reduced ability to adhere to peroxynitrite-modified fibrinogen. The percentage of ADP-induced platelet aggregation decreased as a function of peroxynitrite-mediated modification of fibrinogen molecule.     

Estrogen stimulation of DNA-dependent DNA polymerase activity in immature rat uterus

DNA-dependent DNA polymerase activity in the immature rat uterus has been examined in terms of molecular species present and their response to estrogen treatment. The molecular species of DNA polymerase were characterized by DEAE-cellulose chromatography, sucrose density gradient analysis, sulfhydryl reagent sensitivity and optimal assay conditions. DNA polymerase activity was found predominantly in the high-speed cytosol but was also present in 0.4 M KCl nuclear extract preparation. DNA polymerase β activity was only observed in nuclear extracts. Estradiol treatment resulted in a dose-dependent, estrógen-specific increase in DNA polymerase activity, principally due to increases in cytoplasmic DNA polymerase activity. A 3–4-fold maximal increase of DNA polymerase activity occurred 24–30 h after a single hormone treatment in close correspondence to hormone-induced increased DNA synthesis. When hormone treatment was sustained by daily injections of estradiol, the DNA polymerase response became refractory to continued stimulation after two days.     

Estrogen action in vitro: regulation of thyroid stimulating and other pituitary hormones in cell cultures.

Primary cell cultures of ovine pituitaries can maintain production of thyroid stimulating hormone (TSH) for as long as 24 days. These cultures responded in a normal fashion to thyroxine by decreasing TSH secretion. Addition of thyrotropin releasing hormone increased TSH secretion. Physiologic levels of estradiol-17 beta (10(-11)-10(-9)M) produced a five-fold increase in secretion of TSH and a two-fold increase in intracellular TSH concentration in cell cultures. Common estrogens, but not common progestins, androgens and glucocorticoids affected TSH production. Markedly different effects of estrogen in the pituitary on follicle stimulating, luteinizing and thyroid stimulating hormones and prolactin are discussed in terms of current models of estrogen action.     

Bulbectomy and sensitivity to estrogen: Anatomical and functional specificity

In order to clarify the influence of the olfactory system on female sexual behavior, ovariectomized rats were given sham operations (SHAM), total bilateral olfactory bulbectomy (TBULBX), partial bulbectomy (PBULBX), anterior olfactory nucleus lesions (AON) or accessory olfactory bulb lesions (AOB), and tested for lordosis behavior. Only TBULBX resulted in increased sensitivity to estradiol benzoate (EB) in that lordosis quotients (LQ) were increased and rejection behavior decreased following administration of 2, 4 or 8 μg EB/kg/day for 3 days. Only TBULBX group rats were anosmic on 2 postoperative tests. TBULBX group rats showed very mild hyperresponsiveness on an emotionality test. Effects of TBULBX on LQ are not due to general sensory hyperresponsiveness or EB-induced hyperresponsiveness since no differences in the quality of lordosis occurred, and no differences occurred in latency to paw-lift on hot plate tests with or without EB. Heightened EB sensitivity in the TBULBX group is not due to adrenal steroids since following adrenalectomy and 8 μg EB/kg treatment, TBULBX group LQ scores were still elevated relative to those of SHAM controls. The LQ scores of PBULBX group rats were intermediate to those of SHAM and TBULBX group rats. Bulbectomy-induced alterations in sensitivity to EB as measured by the LQ do not appear to be due to alterations in “arousal” mechanisms in general. While deficits in olfactory perception might exacerbate the effect, it is unlikely that anosmia per se is sufficient to induce major alterations in the degree of sexual receptivity following EB. The magnitude of behavioral effects of bulbectomy on EB sensitivity may be related, to some extent, to the amount of bulb tissue removed. It is possible that bulbectomy may enhance behavioral sensitivity to EB by disrupting biochemical responses to EB in limbic system structures which normally exert an inhibitory influence over sexual receptivity.     

Combined occurrence of filaggrin mutations and IL-10 or IL-13 polymorphisms predisposes to atopic dermatitis

Background: Although filaggrin mutations are presently believed to play a key role in the development of atopic dermatitis (AD), obviously also immunological factors involved in acquired immune response are important for the development of allergic inflammation. Objective: To assess the frequency of FLG mutations and the polymorphisms 590 C/T in the IL‐4 gene, ‐1082A/G in the IL‐10 gene and ‐1055C/T in the IL‐13 gene in patients with AD and their correlations between severity of AD and asthma. Methods: R501X and 2282del4 FLG mutations and IL‐4, IL‐10 and IL‐13 polymorphisms were assayed in 163 patients with AD of Polish origin. Results: In the Polish patients with AD, the prevalence of FLG mutations was higher in patients with AD than in the controls and 2282del4 FLG mutation was more frequent than R501X, and it was associated with a 6‐fold higher risk for AD development (P < 0.001; OR: 5.76), moderate or severe disease course, early onset of asthma and palmar hyperlinearity. Significant interactions between the 2282del4 FLG mutation and the CT genotype for IL‐13 or GG genotype for IL‐10 and a higher risk for developing AD were demonstrated. Conclusion: FLG mutation, alone and in combination with certain IL‐10 or IL‐13 polymorphisms, enhances the risk for the development of AD in the Polish population.     

Characteristics of the course of peritonitis in relation to the degree of perforation of the gastrointestinal tract

An examination and treatment of 80 patients with general forms of peritonitis has shown that the course of the disease is greatly dependent on the character of the bacterial dissemination of the abdominal cavity. A microbiological examination has shown that in all the levels of perforation of the gastro-intestinal tract there are associations of various microorganisms. The most severe course of peritonitis is observed when caused by infection by colonic contents with prevailing anaerobic ++non-clostridial microflora in the exudate. The method of repeated revisions of the abdominal cavity should be used for these forms of peritonitis.     

Plasma growth hormone (GH)-releasing hormone levels in patients with lung carcinoma

OBJECTIVE: The aim was to investigate the serum levels of growth hormone releasing hormone and GH in patients with lung carcinoma. DESIGN After an overnight fast a plasma sample was collected for determination of growth hormone releasing hormone and GH. PATIENTS: The investigation was performed in 28 patients with non small cell lung carcinoma, in 44 patients with small cell lung carcinoma, and 10 patients with non malignant lung disease. A group of 37 normal subjects served as control. MEASUREMENTS: Growth hormone releasing hormone and GH were determined by radioimmunoassay. RESULTS: Patients with small cell lung carcinoma showed higher plasma growth hormone releasing hormone levels (49 +/- 9.4 ng/l) than control subjects (16.3 +/- 2.1 ng/l; P less than 0.05), patients with non small cell lung carcinoma (23.9 +/- 8.8 ng/l; P less than 0.05), and patients with non malignant lung disease (12.7 +/- 5.5; P less than 0.05). Basal GH level was lower than 5 micrograms/l in all patients except five patients with small cell lung carcinoma and one patient with non small cell lung carcinoma. CONCLUSIONS: The higher plasma growth hormone releasing hormone levels in patients with small cell lung carcinoma compared to normal controls and patients with non small cell lung carcinoma and patients with non malignant lung disease, confirm the frequent neuroendocrine activity of this particular tumour.