Liver and Heart Mitochondrial Succinate Dehydrogenase Activity of Newborn Rats in Anoxic Hypoxia and Starvation

Succinate dehydrogenase activity was determined in the liver and heart of newborn rats after 3 and 48 hours' exposure to anoxic hypoxia (10% O₂) and after 48 hours' starvation. Control determinations were made on newborn animals of corresponding ages, full term foetuses (21 days), infantile (1 and 2 weeks) and full grown animals. Hypoxia for 3 h had no influence on succinate dehydrogenase activity at all in either the heart or liver mitochondria of the newborn animals. After 48 h no difference was observed in the liver between the hypoxic animals and the starved controls of the same age, though starvation itself had resulted in a significant increase in activity, as much as 42%. When liver mitochondrial succinate dehydrogenase in normal mitochondria was activated by preincubation mitochondria with the substrate, the activity increase obtained was greater than that resulting from starvation. The increase in activity in the heart of the hypoxic or starved animals was not significant (< 10%).     

Age- and training-related changes in the collagen metabolism of rat skeletal muscle

Summary The effects of ageing and life-long endurance training on the collagen metabolism of skeletal muscle were evaluated in a longitudinal study. Wistar rats performed treadmill running 5 days a week for 2 years. The activities of collagen biosynthesis enzymes, prolyl-4-hydroxylase and galactosylhydroxylysyl glucosyltransferase, were highest in the muscles of the youngest animals, decreased up to the age of 2 months and from then on remained virtually unchanged. The enzyme activity in young animals was higher in the slow collagenous soleus muscle than in the rectus femoris muscle. The enzyme activity in the soleus muscle was higher for older trained rats than older untrained rats. The relative proportion of type I collagen increased and that of type III collagen decreased with age, suggesting a more marked contribution by type I collagen to the agerelated accumulation of total muscular collagen. The results show that collagen biosynthesis decreases with maturation and that life-long endurance training maintains a higher level of biosynthesis in slow muscles.     

High expression of nitric oxide synthases is a favorable prognostic sign in non-small cell lung carcinoma

Immunohistochemical expression of neuronal (n), endothelial (e), and inducible (i) NOS and their association with the type, grade, apoptotic index, proliferation of tumors and the survival of patients were investigated in 89 biopsies of non-small cell lung carcinoma (NSCLC). In tumor cells, expression of iNOS was detected in 35/89 (40%) cases, while 79/89 (89%) and 72/89 (81%) cases showed weak to intense positivity for eNOS and nNOS, respectively. Strong eNOS staining was seen significantly more often in adenocarcinomas than in squamous cells carcinomas (p=0.016), and iNOS immunoreactivity was seen more often in grade I-II tumors than in grade III tumors (p=0.024). There was no significant difference between the low and high apoptotic indexes or between the low and high proliferation rates of tumors in any instance of NOS staining. The patients with tumors showing high nNOS expression tended to have better survival than the others (p=0.06, log-rank; p=0.04, Bresow; p=0.048, Tarone-Ware). Similarly, the patients with tumors showing high expression of iNOS, eNOS and nNOS, as determined by a combined sum index, had a better survival than those with a low sum index for these enzymes (p<0.05). The results show intense expression of eNOS and nNOS, and moderate expression of iNOS in tumor cells of non-small cell carcinoma. Intense NOSs expression seems to be a favorable prognostic sign in non-small cell lung carcinoma.     

Peroxiredoxins in breast carcinoma.

PURPOSE: Peroxiredoxins (Prxs) are a novel group of peroxidases containing high antioxidant efficiency and some of them having also effects on cell differentiation and apoptosis. The mammalian Prx family has six distinct members located in various subcellular locations, including peroxisomes and mitochondria, places where oxidative stress is most evident. EXPERIMENTAL DESIGN: We examined immunohistochemically a large set of samples from patients with breast carcinoma and investigated associations with parameters such as tumor-node-metastasis classification, hormone receptor status, and patient survival. Three biopsies of healthy breast tissue were used as controls. RESULTS: Expression of peroxiredoxins I, III, IV, and V was found in >or=80% of cases, whereas the expression of Prx II and VI was less frequent. Increased expression of Prx III was found to associate with the presence of progesterone (P = 0.02) and estrogen (P = 0.03) receptors, and Prxs IV (P = 0.009) and VI (P = 0.04) were overexpressed in progesterone receptor positive cases. Prx V was the only isoform that associated with items of tumor-node-metastasis classification, it was connected to a larger tumor size (P = 0.05) and positive lymph node status (P = 0.04). Prx V positivity was also connected with shorter survival (P = 0.04), whereas Prxs III (P = 0.002) and IV (P = 0.02) were related to better prognosis, probably resulting from their connection with a positive hormone receptor status. CONCLUSIONS: In conclusion, we found that expression of peroxiredoxins, especially III, IV and V, is increased in breast malignancy, suggesting the induction of Prxs as response to increased production of reactive oxygen species in carcinomatous tissue.     

Longitudinal Dynamics of HPV16 Antibodies in Saliva and Serum among Pregnant Women

Oral infections with high-risk (hr)HPV genotypes are associated with a subset of head and neck squamous cell carcinomas. Oral hrHPV infections may result from having oral sex, but also from horizontal infection from mouth to mouth. In such cases, saliva can serve as a vehicle for HPV transmission. Still, the prevalence and dynamics of salivary HPV antibodies in healthy non-vaccinated individuals are poorly known and the role of the salivary antibodies in protection from oral HPV infection is unclear. We used an ELISA assay to evaluate the dynamics and correlation of oral HPV16 infection and HPV16L1 and E7 specific antibody levels in saliva and serum samples among 39 women, 13 of which had persistent oral HPV16 infection. The women were mothers-to-be, sampled before delivery and followed up for 36 months postpartum. HPV16L1 IgG and sIgA antibodies were regularly detected in saliva. Antibody levels in serum remained stable during the 36-month follow-up, while antibody levels in saliva fluctuated. There was considerable individual variation in salivary HPV16L1 antibody levels, and some women had persistent oral HPV16 infection but no salivary antibodies. No differences in salivary HPV16L1 levels were found between the women with persistent or transient oral HPV16 infection.     

Intraoperative changes in coronary resistance during aortic valve replacement

Coronary vascular resistance was investigated in 10 patients undergoing aortic valve replacement using continuous constant-pressure coronary perfusion at 32 degrees C. After coronary flow was initiated, resistance was low but increased steadily until it reached a certain resting level. The plateau was attained faster after a short period of anoxia than after a longer period. The initial postischemic resistance was dependent on the duration preceding anoxia, being of the same magnitude after short and moderate periods of anoxia but significantly higher after a long period. This resistance difference between the groups lasted for the whole perfusion. The total coronary resistance and flow reached a plateau in 30 minutes, while resistance increased threefold but flow decreased to half of the initial postanoxia flow. Our results indicate the importance of initiating coronary perfusion soon after aortic cross-clamping to avoid increase in the initial vascular resistance and subsequent inadequate myocardial flow.     

Expression of the thioredoxin system in interstitial lung disease

The thioredoxin system containing thioredoxin (Trx) and thioredoxin reductase (TrxR) has profound effects on cell proliferation and protection against exogenous oxidants. The significance of the Trx system in human lung and lung diseases is, however, largely unresolved. Altogether, 66 specimens of human lung were investigated by immunohistochemistry for their expression of Trx and TrxR. The diseases included interstitial pneumonias such as usual interstitial pneumonia (UIP), desquamative interstitial pneumonia (DIP), and UIP associated with collagen vascular diseases (CVD-ILD), and granulomatous diseases such as sarcoidosis and allergic alveolitis. The ultrastructural localization of Trx and TrxR was analysed by immunoelectron microscopy. In healthy lung, Trx and TrxR were expressed in bronchial epithelium and alveolar macrophages. Trx and TrxR were highly concentrated in areas of metaplastic epithelium in UIP and in alveolar macrophages in DIP, though fibrotic areas in UIP were mainly negative. The expression of both enzymes was clearly weaker in CVD-ILD than in UIP. Granulomas of sarcoidosis showed moderate to intense Trx immunoreactivity. Ultrastructurally, Trx and TrxR were expressed diffusely in the cytosolic compartment and plasma membrane of metaplastic type II pneumocytes, macrophages, and bronchial epithelial cells. This study highlights the importance of Trx and TrxR in primary defence in bronchial epithelium, alveolar epithelium, and macrophages in human lung, but also indicates that elevated expression of these proteins may serve as markers of ongoing cell regeneration and inflammation.     

Antioxidant defense mechanisms in human neutrophils

Neutrophils have a short half-life and high tendency to undergo apoptosis. One feature that may influence these characteristics is the antioxidant/oxidant balance of these cells. There are few studies on the levels of antioxidant enzymes in human neutrophils. We have analyzed by immunohistochemistry of paraffin-embedded cells and from cytospin preparations the most important antioxidant proteins in human neutrophils, and compared their levels with those in blood monocytes. Neutrophils showed moderate to high catalase, weak to moderate extracellular superoxide dismutase, and weak copper zinc superoxide dismutase and gamma-glutamylcysteine synthetase immunoreactivities. There were no detectable levels of manganese superoxide dismutase, thioredoxin, and heme oxygenase 1. Some differences were observed between the samples prepared by embedding in paraffin or by cytospin. These results, in combination with a recent study from this laboratory, suggest that a prominent feature in neutrophils is their high catalase activity but lower level of glutathione-dependent antioxidant enzymes. The differences in antioxidant profiles in neutrophils and monocytes may have important effects on the life span of human neutrophils, in both healthy and diseased tissues.     

Overexpression of peroxiredoxins I, II, III, V, and VI in malignant mesothelioma

Peroxiredoxins (Prxs) are a recently characterized group of thiol-containing proteins with efficient antioxidant capacity, capable of consuming hydrogen peroxide in living cells. Altogether six distinct Prxs have been characterized in mammalian tissues. Their expression was investigated in histological samples of mesothelioma and in cell lines established from the tumours of mesothelioma patients. Four cases with histopathologically healthy pleura from non-smokers were used as controls. Healthy pleural mesothelium was negative or very weakly positive for all Prxs. In mesothelioma, the most prominent reactivity was observed with Prxs I, II, V, and VI. Prx I was highly or moderately expressed in 25/36 cases, the corresponding figures for Prxs II-VI being 27/36 (Prx II), 13/36 (Prx III), 2/36 (Prx IV), 24/36 (Prx V), and 30/36 (Prx VI). Positive staining was observed both in the cytosolic and the nuclear compartment, with the exception of Prx III, which showed no nuclear reactivity. The staining pattern of Prxs III and V was granular. Immunoelectron microscopic localization of Prxs was in accordance with the immunohistochemical findings, showing diffuse cytoplasmic localization for Prxs I, II, IV, and VI and distinct mitochondrial labelling for Prxs III and V. There was no significant association between the extent of staining and different Prxs. It appeared that Prxs may not have prognostic significance, but being prominently expressed in most mesotheliomas these proteins, at least in theory, may play a role in the primary drug resistance of this disease.