Tumour necrosis factor-α contributes to improved cardiac ischaemic tolerance in rats adapted to chronic continuous hypoxia.

AIM: It has been demonstrated that tumour necrosis factor-alpha (TNF-α) via its receptor 2 (TNFR2) plays a role in the cardioprotective effects of preconditioning. It is also well known that chronic hypoxia is associated with activation of inflammatory response. With this background, we hypothesized that TNF-α signalling may contribute to the improved ischaemic tolerance of chronically hypoxic hearts. METHODS: Adult male Wistar rats were kept either at room air (normoxic controls) or at continuous normobaric hypoxia (CNH; inspired O2 fraction 0.1) for 3 weeks; subgroups of animals were treated with infliximab (monoclonal antibody against TNF-α; 5 mg kg(-1), i.p., once a week). Myocardial levels of oxidative stress markers and the expression of selected signalling molecules were analysed. Infarct size (tetrazolium staining) was assessed in open-chest rats subjected to acute coronary artery occlusion/reperfusion. RESULTS: CNH increased myocardial TNF-α level and expression of TNFR2; this response was abolished by infliximab treatment. CNH reduced myocardial infarct size from 50.8 ± 4.3% of the area at risk in normoxic animals to 35.5 ± 2.4%. Infliximab abolished the protective effect of CNH (44.9 ± 2.0%). CNH increased the levels of oxidative stress markers (3-nitrotyrosine and malondialdehyde), the expression of nuclear factor κB and manganese superoxide dismutase, while these effects were absent in infliximab-treated animals. CNH-elevated levels of inducible nitric oxide synthase and cyclooxygenase 2 were not affected by infliximab. CONCLUSION: TNF-α plays a role in the induction of ischaemia-resistant cardiac phenotype of CNH rats, possibly via the activation of protective redox signalling.

Prostate specific antigen molecular forms in breast cyst fluid and serum of women with fibrocystic breast disease.

We have analyzed matched serum and breast cyst fluid samples for total PSA from 148 patients with fibrocystic breast disease. We have also determined the molecular forms of PSA (free PSA and PSA bound to alpha1-antichymotrypsin) in 78 breast cyst fluid samples. We found that total PSA can be detected in all cyst fluids and in about 75% of female sera. The median total PSA concentration in breast cyst fluid (bcf) is about 30 times higher than the median in the corresponding sera. Breast cyst fluid and serum PSA are not correlated with each other. Total serum PSA is inversely associated with patient age but the inverse association between bcf PSA and age is weak. Lower total PSA in bcf was seen in women who breast feed, and higher bcf PSA is associated with multiple cysts. Type I cysts (with a high K+/ Na+ ratio) tend to have higher total PSA than Type II cysts. All but three of the fractionated cyst fluids (75/78; 96%) had free PSA as the predominant molecular form. The most consistent finding of our study was the positive association between the cyst fluid K+/Na+ ratio and the free to bound PSA ratio. This association was confirmed by Spearman correlation as well as by Wilcoxon and chi-square analysis. Secretory/apocrine cysts (Type I) tend to have more total PSA and proportionally more free PSA than transudative/flattened cysts (Type II).

Quantification of pepsinogen C and prostaglandin D synthase in breast cyst fluid and their potential utility for cyst type classification.

OBJECTIVE: To quantify pepsinogen C (PEPC) and prostaglandin D synthase (PGDS) in breast cyst fluid and examine if these two parameters can be used for breast cyst type classification. DESIGN AND METHODS: We quantified PEPC and PGDS in 92 and 50 breast cyst fluids, respectively, using previously established immunofluorometric procedures. We then examined if the levels of PEPC or PGDS correlate with the type of cyst or with other clinicopathological variables. RESULTS: Quantitative analysis of the breast cyst fluids indicated that PEPC is present in all cyst fluids at various concentrations ranging from 3 to 31,000 ng/mL. PGDS positivity was confined to 30% of the cyst fluids. PEPC and PGDS levels were correlated with the breast cyst fluid cation ratio and were associated with the type of the cyst. Increased PEPC levels in breast cyst fluids were significantly correlated with a > or = 1.5 K+/Na+ ratio and were associated with the secretory/apocrine type of cyst (Type I) (p = 0.011). Immunoreactive PGDS levels were highly correlated with a low cation ratio and were associated with the transudative/flattened type of breast cyst (Type II) (p = 0.0003). A weak association was observed between PEPC levels in breast cyst fluid and menopausal status (p = 0.093). No significant associations were observed for either PEPC or PGDS concentration in breast cyst fluid and number of cysts, recurrence of the disease, family history of breast cancer, number of children, abortion, and breast feeding. CONCLUSIONS: Quantification of PEPC and PGDS in breast cyst fluid may be useful in the subclassification of cyst type in patients with gross cystic disease.

Stimulation of phosphoinositide kinases by thrombin is restricted to the plasma membrane in platelets.

This study was based on the hypothesis that lipid kinases in the different subcellular fractions would be differently affected by thrombin-treatment of platelets prior to subcellular fractionation. When using our previously reported method for subcellular fractionation on Percoll self-generated gradients, marker enzymes were detected as previously described. Stimulation of intact platelets with thrombin induced increased activities of PtdIns 4-kinase, PtdIns(4)P 5-kinase and PtdIns(4,5)P(2) 3-kinase in the plasma membrane fraction. PtdIns 4-kinase was also detected in internal membranes but was not modified by thrombin. We conclude that the production of phosphoinositides phosphorylated on the D3 and D5 positions of the inositol ring is restricted to the plasma membrane and that only the enzymes that are present in, or relocated to, the plasma membrane when platelets are activated are stimulated by thrombin.

Molecular forms of prostate-specific antigen in the serum of women with benign and malignant breast diseases.

Using a highly sensitive immunofluorometric procedure, we measured the total prostate-specific antigen (PSA) concentration in 632 sera obtained from female blood donors and women with idiopathic hirsutism, breast cancer or benign breast diseases. A total of 50 sera with total PSA > 15 ng l(-1) were fractionated by high-performance liquid chromatography (HPLC) in order to resolve the two immunoreactive molecular forms, i.e. free PSA (approximately 30 kDa) and PSA bound to alpha1-antichymotrypsin (PSA-ACT, 100 kDa). We found that breast cancer patients have presurgical serum total PSA levels similar to those of blood donors. Total serum PSA concentration decreases with age in women with idiopathic hirsutism, in cancer patients and in patients with benign breast diseases. The major molecular form of PSA in the serum of all normal and hirsute women (n = 15) is PSA bound to the proteinase inhibitor alpha1-antichymotrypsin. The major molecular form in 44% of presurgical cancer patient sera is free PSA. A total of 58% of benign breast disease patients also have in their serum mainly free PSA. We conclude that about half the patients with breast cancer or benign breast diseases have free PSA as the major molecular form in their serum, whereas patients without breast pathologies (normal blood donors, idiopathic hirsutism) have PSA bound to alpha1-antichymotrypsin as the major molecular form. The ratio of PSA/PSA-ACT may have value as a simple biochemical test for diagnosis of breast pathologies including breast cancer.