The influence of the low-energy defibrillating impulse on the endothelin-1 concentration in the left heart ventricle and blood serum of the healthy rabbits

The influence of low-energy defibrillation on changes in the ET-1 levels in the myocardium and on disruptions in coronary blood flow and microcirculation being their consequence still remains unclear. Myocardial microcirculatory dysfunction is considered as a significant cause underlying myocardial dysfunction in post-cardiac arrest syndrome. This study is aimed at evaluating time-dependent changes in ET-1 levels in serum and the heart of a healthy rabbit following the application of a low-energy two-phase shock impulse. The research was conducted in 35 healthy rabbits at the age of 36 - 42 weeks and with body mass from 3200 to 4150 grams. The animals were divided in a randomized way into four groups depending on the dose of the electrical energy planned for the application during the experiment. The life parameters of the animals were monitored with the application of BeneView T5 patient monitor. The concentration of endothelin-1 in the groups was measured before, 15 and 360 minutes after the application of the low-energy double-phase straight-lined electrical impulse. A transthoracic low-energy defibrillation shock impulse causes a long-term increase in the endothelin-1 levels in the heart muscle and blood serum in a healthy rabbit. The increase in ET-1 levels results from the effect of electrical energy, independently of consequences of the ischemia/reperfusion injury. The increase in the endothelin-1 levels may lead to capillary blood flow abnormalities in the heart, contributing to the development of its dysfunction in the course of postresuscitation disease.

The role of the tissue plasminogen activator as a prognostic and differentiation factor in patients with pancreatic cancer and chronic pancreatitis

Unsatisfactory pancreatic cancer treatment outcomes have prompted multiple avenues of research focused on identifying not only biomarkers of pancreatic adenocarcinoma progression but also potential prognostic survival factors in patients with pancreatic adenocarcinoma. Study consisted of 75 patients who underwent pancreatic resections between 2006 and 2011: 35 patients with pancreatic ductal adenocarcinoma (PC), 30 patients with chronic pancreatitis (CP), and a non-malignant control group (NMCG) of 10 patients who underwent surgery due to benign tumors. Tissue plasminogen activator (t-PA) concentrations in tissue homogenates and sera were evaluated. The mean t-PA concentration in PC tissue homogenates was 12.3 ± 2 (7.5, 15) ng/mg. Compared with the t-PA concentration in the PC group, lower concentrations of t-PA (3.3 ± 0.7 (2.2, 4.7) ng/mg and 5.9 ± 0.8 (4.6, 7.3) ng/mg (P < 0.01)) were observed in tissue homogenates of the CP and the NMCG patients, respectively. Although serum concentrations of t-PA did not differ between patient groups, in PC patients, the t-PA concentrations were higher in sera than in tissue homogenates. In contrast, the CP and NMCG patient groups had lower t-PA concentrations in sera compared with tissue homogenates. Increasing tissue homogenate t-PA concentrations were associated with blood vessels infiltration. Tissue homogenate and serum t-PA concentrations were not related to the survival rate of patients with PC. The t-PA concentration above 7.45 ng/ml in tissue homogenates was indicative of PC. We concluded that higher concentrations of t-PA were observed in pancreatic cancer tissue compared to chronic pancreatitis, suggesting its potential role in the development and progression of pancreatic cancer. In contrast, the lack of significant differences in the serum t-PA concentrations between treatment groups suggests that serum t-PA concentrations may not be suitable as a biomarker for the diagnosis of pancreatic cancer.

Administration of low doses of tumor necrosis factor-alpha protects rat liver from ischaemic damage and reperfusion injury

Liver ischaemia and reperfusion (IR) injury is a significant clinical problem. The aim of our study was to investigate the protective effect of tumor necrosis factor-alpha (TNF-alpha) on rat liver ischaemia-reperfusion injury. A TNF-alpha dose of 3 microg/kg body weight was injected into rats that had undergone partial (70%) ischaemia and reperfusion. The activities of alanine aminotransferase (ALT) and aspartate aminotransferase (AST), total blood antioxidant level (using the FRAP test), and the concentrations of TNF-alpha, myeloperoxidase (MPO) and malondialdehyde (MDA) in liver homogenates after 1, 6, and 72 hours of reperfusion were measured. It was demonstrated that, rats subjected to IR, the administration of small doses of TNF-alpha significantly reduced ALT and AST activities after 60- minute liver ischaemia and 1 or 6 hour of reperfusion. The strongest reductions in ALT and AST activities were seen after 1 hour of reperfusion (30% and 35%, respectively). Exogenous TNF-alpha reduced the release of this cytokine in all observed periods, with the greatest reduction observed after 1 hour of reperfusion. Decreases in MPO concentration (by 40-45% in all periods of observation), as a marker of hepatic neutrophil infiltration, and in MDA concentration, the end-product of lipid peroxidation (by 55-60% at all time points), accompanied the reduction of TNF-alpha release. The administration of TNF-alpha to the rats after IR did not alter total plasma antioxidant potential, as assayed by the FRAP test, after 1 hour of reperfusion; however, at the later times a marked increase (approximately 40-50%) occurred. We demonstrated that intraperitoneal injections of small doses of TNF-alpha protect rat livers from IR injury. The mechanism of this protection is related to reductions in the release of TNF-alpha during IR after injection of this cytokine, resulting in reductions in oxidative stress and inflammation during the later phase of reperfusion.

Changes in lipid metabolism in women with age-related macular degeneration

Age-related macular degeneration (AMD) is one of the leading causes of visual loss among people aged 65 and older. At present the origin of AMD still remains unknown. The objective was to evaluate the chosen lipid and lipoprotein concentrations in blood of patients with AMD. Sixty women aged 55-71 (mean age 65.1+/-5.7) were treated in the outpatient ophthalmological clinic for more than two years because of AMD. We evaluated total serum cholesterol (TCH), triglycerides (TG), HDL-cholesterol (HDL), LDL-cholesterol (LDL), lipoprotein (a) (Lp(a)), apolipoprotein AI (Apo AI) and apolipoprotein B (Apo B) by direct spectrophotometry (Human and Randox standard kits, USA). We found a significant increase of TCH, LDL and TG (224.36+/-41.67 mg/dl, 159.02+/-39.66 mg/dl and 120.92+/-42.64 mg/dl), and a significant decrease of HDL (38.68+/-6.36 mg/dl) in the AMD patients when compared with the control group. We have not found a significant difference in the average TG level between the studied groups. The concentration of Apo B was markedly increased (164.66+/-46.46 mg/dl) and Apo AI concentration was markedly decreased (128.9+/-17.01 mg/dl) in the AMD patients when compared with the control group. There was no significant difference in the concentration of the Lp(a) between the two groups. The results of our present study could point to the fact that changes in the lipid metabolism could be one of the very important risk factors involved in the pathogenesis of AMD.

Homocysteine, vitamin B12, and folic acid in age-related macular degeneration

PURPOSE

Hyperhomocysteinemia is considered an independent risk factor for atherosclerosis and thrombosis. The purpose of this study was to evaluate plasma homocysteine, red blood cell folate, plasma folate, and plasma vitamin B12 concentration in patients with exudative age-related macular degeneration (ARMD).

METHODS

The participants of this study included 30 patients aged 60 to 71 years (mean age 66.2+/-3.6) with exudative ARMD. Plasma homocysteine levels were determined by high performance liquid chromatography (HPLC). Red blood cell folate, plasma folate, and plasma vitamin B12 concentration were determined using a standard kit (Dualcount Solid Phase No Boill radioassay kit for B12/folic acid, DPC Diagnostic, USA) by radioassay method.

RESULTS

The plasma concentration of Hcy (14.88+/-6.23 micromol/L) in ARMD patients was significantly increased (p<0.0001) compared with the control group (8.72+/-3.34 micromol/L). We found not a significant decrease of the plasma vitamin B12 concentration in the ARMD group (476.88+/-220.91 pg/mL) compared with the control group (527.08+/-208.97 pg/mL). Red blood cell folate (158.44+/-56.30 ng/mL) and plasma folate (6.5+/-3.4 ng/mL) in ARMD patients were also not significantly decreased when compared with the control group (183.86+/-59.33 ng/mL and 7.93+/-5.05 ng/mL).

CONCLUSIONS

Hyperhomocysteinemia might be one of the risk factors for the exudative form of ARMD.

The relationship between bone metabolism, melatonin and other hormones in sham-operated and pinealectomized rats

OBJECTIVE

The influence of pinealectomy and long-term melatonin (MEL) administration on circadian oscillations of selected biochemical markers of bone metabolism [serum alkaline phosphatase (ALP) activity, carboxyterminal propeptide type I procollagen (PICP) and carboxyterminal telopeptide type I collagen (ICTP) concentrations as well as urinary excretion of hydroxyproline (HYP) and Ca] and possible involvement of circadian secretion of IGF-I, parathyroid, thyroid, adrenal cortex and gonads function in this mechanism was evaluated.

METHODS

Studies were performed in 192 adult male Wistar rats weighing 145 +/- 9 g which were subjected to pinealectomy or sham operation. In half of the animals from each group MEL (Sigma, USA) in a dose of 50 mg/100 g b.w. was administered intraperitonealy (daily between 17.00 and 18.00 h for a 4-week period). Material for studies (blood and urine) was collected every 3 hours during a day. Hormones, PICP and ICTP concentrations were determined with the use of RIA methods. whereas ALP, HYP and Ca values - spectrophotormetrically.

RESULTS

The study has shown that pinealectomy had an inducing, while exogenous MEL a suppressing effect upon the level of investigated biochemical markers of bone metabolism. Furthermore, substantial changes in the values of amplitude and phase of their circadian oscillations were shown. Distinct, dependent on the time of day disturbances in circadian fluctuations of PICP, ICTP, HYP and Ca showing generally negative correlation with changes in endogenous MEL concentrations and positive with IGF-I and corticosterone (B) levels were found. In addition, changes in circadian oscillations of ALP and PICP correlated negatively with daily oscillations of calciotropic hormones and B. However, ICTP, HYP and Ca concentrations correlated positively with circadian fluctuations of B and FT3 (the latter only in sham operated rats receiving MEL).

CONCLUSIONS

This study showed that both pinealectomy and long-term MEL administration influence the circadian rhythm of bone metabolism and that an important role in the mechanism of this dependence is played by the changes of endogenous MEL levels. Secondary changes in circadian oscillations of calciotropic hormones, IGF-I and corticosterone concentrations, caused by pinealectomy and long-term MEL administration result in altered bone metabolism rhythm.

Changes in blood antioxidants and several lipid peroxidation products in women with age-related macular degeneration

PURPOSE

The aim of this study was to evaluate the ferric reducing ability of plasma (FRAP), selected enzymatic and non-enzymatic components of the antioxidative system, and the intensity of peroxidative processes in the blood of patients with age-related macular degeneration (AMD).

METHODS

In the peripheral blood, we evaluated FRAP; concentrations of vitamins C, A, and E; and of thiols. We assayed the activity of enzymatic components of the antioxidative system-superoxide dismutase, catalase, ceruloplasmin and the concentration of reduced glutathione as an indicator of glutathione peroxidase activity. In order to determine the intensity of lipid peroxidation, we measured the concentrations of malondialdehyde and hydroxyalkenales (MDA-HNA) and conjugated diens (CD).

RESULTS

We found a significant increase in FRAP in patients with AMD compared with the control group. The average concentrations of vitamins A and C were low and vitamins E and GSH were significantly higher in AMD than in the control group. The activity of almost all the antioxidative enzymes was high. We found a significant increase in MDA-HNA but no difference in CD.

CONCLUSIONS

The significantly higher concentration of lipid peroxidation products in patients with AMD indicates an important pathogenic role of oxido-reduction disturbance. The high FRAP concentration may be one of the protective mechanisms in oxidation stress. The adaptive increase of the antioxidant barrier mostly involves the enzymatic components.

Influence of pinealectomy and long-term melatonin administration on GH-IGF-I axis function in male rats

BACKGROUND

A relationship between circadian GH-IGF-I axis activity and pineal gland function in rats is not sufficiently elucidated, particularly in the aspect of melatonin (MEL) participation with relation to a possible mechanism of these dependencies.

OBJECTIVE

Influence of pinealectomy and long-term MEL administration on circadian GH-IGF-I axis function in male rats was evaluated. An attempt was also made to determine whether the effect of exogenous MEL is dependent on the pineal gland presence.

METHODS

Studies were performed in 192 sexually mature male Wistar rats, which were subjected to pinealectomy or sham operation. In half of the animals from each group MEL (Sigma, USA) in dose of 50 microg/ 100g b.m. was administrated intraperitoneally (daily between 5 and 6 pm during a 4-week period). Blood for RIA assays of MEL, GH and IGF-I concentrations was collected every 3 hours during a day-beginning at 8 am (rats killed by decapitation).

RESULTS

Significant influence of pinealectomy and exogenous MEL on a daily profile of endogenous MEL in rats was confirmed. Distinct, dependent on the time of the day anomalies in circadian oscillations of GH and IGF-I showing positive correlation with changes in endogenous MEL concentrations were also shown. GH rhythm was suppressed in a group of rats with removed pineal gland; after pinealectomy distinct decrease and after MEL use - distinct increase of GH and IGF-I concentrations during the day were observed. It had influenced mean daily concentrations and values of amplitude of circadian GH and IGF-I oscillations in all studied groups of animals. In rats with preserved pineal gland the effect of exogenous MEL action was more intensified.

CONCLUSIONS

Pineal gland can influence circadian function of GH-IGF-I axis, and in mechanism of this dependence, changes in endogenous MEL concentrations seem to play an important role. Administration of MEL in rats after pinealectomy only partly prevents changes of GH-IGF-I axis function caused by gland removal, which can indicate participation of other pineal gland substances in generating disturbances. Influence of exogenous MEL on GH-IGF-I axis function during the day is dependent on the presence of pineal gland, which can be connected with indirect and/or direct influence of administrated hormone on this gland.

Assessment of the relationship between dynamic pattern of nighttime levels of melatonin and chosen biochemical markers of bone metabolism in a rat model of postmenopausal osteoporosis

BACKGROUND

Lately, there have been suggestions that bone mass changes occurring in postmenopausal women may remain related to melatonin.

OBJECTIVE

To assess the relationship between the dynamic pattern of nighttime levels of melatonin and chosen biochemical markers of bone metabolism in ovariectomized rats--a model of postmenopausal osteoporosis.

METHODS

Mature Wistar female rats were either ovariectomozed or underwent a sham operation. Following this they were killed at 02:00AM at weekly intervals for 8 weeks after surgery. Serum levels of MEL at death related to the chosen biochemical markers of bone formation (alkaline phosphatase--ALP; carboxyterminal propeptide of type I procollagen--PICP, both in serum) and resorption (cross-linked carboxyterminal telopeptide of type I collagen--ICTP in serum; hydroxyproline--HYP and total calcium--Ca, both excreted in urine).

RESULTS

In all ovariectomized rats changes of examined indices of bone tissue metabolism were found to be dynamic and statistically significant relative to the control group; however the changes were more pronounced regarding resorption markers. Following ovariectomy, the increase in ALP and PICP values was found to begin at the 4th and the 1st week, while that in ICTP, HYP and Ca at the 2nd, the 1st and the 1st week, respectively. The ALP and PICP values remained at a similar level until the end of observation, whereas ICTP, HYP and Ca gradually decreased. MEL levels were decreased during the 2nd week following surgery and slightly increased 2 weeks later. The serum MEL levels in the ovariectomized group were significantly and negatively correlated with serum ICTP and both urinary HYP and Ca levels.

CONCLUSION

Our findings in rats seem to corroborate the concept of secondary changes in MEL levels co-participating in the development of bone mass changes characteristic for postmenopausal osteoporosis.

Assessment of the relationship between circadian variations of salivary melatonin levels and type I collagen metabolism in postmenopausal obese women

BACKGROUND

Few experimental and clinical studies show that melatonin (MEL) can play a significant part to modulate circadian bone metabolism. On this basis it was suggested that MEL secretion which altered during 24-h in obese women could be of importance to regulate bony mass defect after menopause.

OBJECTIVE

The aim of the study was to prove if there were any connection between changes in 24-h profile of serum MEL levels and circadian metabolism of type I collagen in postmenopausal women with visceral obesity.

METHODS

The relationship of 24-h profile of salivary MEL and circadian metabolism of type I collagen (as assessed by measuring saliva concentrations of carboxyterminal propeptide of type I procollagen--PICP and cross-linked carboxyterminal telopeptide of type I collagen--ICTP) was investigated in 26 women with visceral obesity (33.5 < BMI < 42.1 kg/m(2)) and 18 healthy volunteers with correct body mass (21 < BMI < 24.5 kg/m(2); 0.73 < WHR < 0.76). The specimens were collected at subjects' home at 3 h intervals during a 24 h span. The age range of all subjects was 52-60 years.

RESULTS

In all the obese women studied a tendency to suppress circadian levels of tested biochemical markers of bone metabolism was observed (especially regarding ICTP); those alterations were accompanied by substantial increment in MEL concentrations during the day. Significant and negative correlation was found between values of acrophase MEL and PICP rhythms and both amplitude and acrophase of MEL and ICTP rhythms.

CONCLUSION

Our results confirm hypothesis that alterations in MEL concentrations might have a protective effect against postmenopausal loss of bone mass.

[Evaluation of selected parameters of collagen metabolism in patients with myopia]

INTRODUCTION

Myopia is a common condition of vision deprivation characterized by the excessive lengthening of the eye axis. There are hypotheses that the elongation of the eye is connected with the connective tissue disorder in which the scleral collagens are inappropriately remodelled. The most common type of collagen and the first to be discovered is type I and it is the dominating one in cornea and sclera. Type III is always found in coexistence with type I.

AIMS

The aim of the study was to evaluate the serum concentration of carboxyterminal propeptyde of procollagen type I (P I CP), aminoterminal propeptyde of procollagen type III (P III NP) (markers of collagen synthesis) and carboxyterminal telopeptyde of collagen type I (I CTP) (marker of collagen disintegration) as markers of the connective tissue metabolism in patients with myopia.

MATERIAL AND METHODS

Serum concentration of P I CP, P III NP and I CTP were studied in 25 (15 female and 10 male) patients with myopia and in 15 emmetropic subjects using the RIA method (Orion Diagnostica).

RESULTS

The serum concentration of P I CP and P III NP increased significantly in patients with myopia when compared with the control group. There was no significant difference in the concentration of both of them among patients with various degrees of myopia, although the concentration of P I CP and P III NP increased with the increase of myopia. The was no statistical difference in the concentration of I CTP in low and medium myopia but we found increased concentration of I CTP in high myopia comparing with control group.

CONCLUSION

The mechanical properties as well as the increased remodelling of the collagen could be some of the factors involved in myopia pathogenesis. Changes in the collagen metabolism concern not only the eye tissue, but probably also disorders of the systemic connective tissue turnover.

[Hormonal changes in male patients with primary open angle glaucoma]

INTRODUCTION

Primary open angle glaucoma (POAG) is the most common type of glaucoma, pathogenesis of which is not completely known. Several clinical studies show that glucocorticoid hormones may be implicated in the pathogenesis of POAG and ocular hypertension. Glucocorticoid receptors have been identified in human outflow tissue of the eye.

AIMS

The purpose of this study, therefore, was to evaluate the serum concentration of total cortisol (TF), total testosterone (TT), free testosterone (FT), FSH (follitropin), LH (lutropin), ACTH (adrenocorticotropin), SHBG (sex hormone-binding globulin), DHEA-SO4 (dehydroepiandrosterone sulfate) as well as free cortisol (UFF) and 17-OHCS in 24 hours urinary samples in patients treated because of POAG.

PATIENTS AND METHODS

Studies were performed in the group of 30 male patients, aged 55 +/- 13 years, treated because of glaucoma for more than two years. Serum and urinary concentration of hormones were studied using RIA methods (DPC).

RESULTS

The serum concentration of TF (652.03 +/- 315.43 nmol/l), UFF (248.75 +/- 99.39 nmol/l) and 17-OHCS (5.47 +/- 2.64 mg/24 h) in urine was increased compared with control group. There was not significant difference in concentration of pituitary-gonadal axis hormones in glaucomatous and control groups of patients.

CONCLUSION

The results could point to the fact that changes in the endocrine system are one of the factors involved in the pathogenesis of POAG. We conclude that an elevated level of cortisol, free cortisol and its metabolites is closely related to the POAG.

Plasma transforming growth factor beta1 in breast cancer patients treated with CMF chemotherapy

BACKGROUND

In early breast cancer patients the transformed epithelial cells are thought to be sensitive to transforming growth factor beta1 (TGFbeta1)-mediated growth arrest. TGFbeta1 may therefore act as an anti-tumour promoter. However, in advanced breast cancer resistance to such TGFbeta1 action develops. Neoplastic cells produce TGFbeta1, which may enhance tumour invasion and metastasis, mainly by intensifying angiogenesis, which is an immunosuppressive action. In the light of the potential role of TGFbeta1 in breast cancer pathogenesis, an understanding of the effect of applied therapeutic methods on plasma TGFbeta1 concentration is essential.

OBJECTIVE

To investigate the effect of adjuvant chemotherapy on plasma transforming growth factor beta1 (TGFbeta1) concentration in breast cancer patients with metastases to axillary lymph nodes.

METHOD

Fifteen stage II breast cancer patients on adjuvant chemotherapy with cyclophosphamide, methotrexate and 5-fluorouracil (CMF) were studied along with 15 healthy premenopausal women.

RESULTS

Plasma TGFbeta1 concentration (determined by the ELISA method) in the breast cancer patients did not differ significantly from that of the healthy women. Adjuvant CMF chemotherapy significantly decreased plasma TGFbeta1 concentration in those pre-menopausal breast cancer women with metastases to axillary lymph nodes.

CONCLUSION

The possible pathogenic action of this growth factor in stage II breast cancer disease warrants further investigation to elucidate whether the induced decrease of blood TGFbeta1 concentration is essential to successful chemotherapy.

[Calcitonin levels in the serum of psoriatic patients]

In this study the serum calcitonin concentrations were assessed in patients with Psoriasis vulgaris. The results were compared with healthy volunteers. The serum calcitonin levels of psoriatic patients was significantly increased than in healthy volunteers.

[Insulin-like growth factor-I: pathophysiologic and clinical aspects]

The paper reviews the factors which affect synthesis and metabolic activity of the insulin-like growth factor-I (IGF-I), its receptor and binding proteins as age, nutritional state, hormonal state and liver function. Attention is also focused on the role of IGF-I in pathogenesis of osteoporosis and neoplastic diseases.

[Evaluation of selected parameters of connective tissue metabolism in patients with primary open angle glaucoma]

PURPOSE

To evaluate the plasma concentration of P I CP and P III NP as markers of the connective tissue metabolism in human with and without POAG. The mechanical properties of the collagen could be one of the common factors involved in the pathogenesis of chronic open angle glaucoma.

MATERIAL AND METHODS

P I CP and P III NP were studied in serum in 20 patients with POAG and in 10 healthy subjects using RIA method.

RESULTS

The concentration of P III NP in the blood serum was markedly increased (3.99 +/- 1.5 micrograms/l) compared with control group (2.84 +/- 0.77 micrograms/l), p < 0.05. There was not significant difference in concentration of P I CP in both groups.

Circadian variations of serum triiodothyronine, thyroxine, corticosterone and lipids in starved rats

Circadian variation of serum triiodothyronine (T3), thyroxine (T4), corticosterone (B) and lipids was studied in male Wistar rats after one week of the starvation. The animals were adopted to 12:12 h light-dark cycle (lights on from 7.00 to 19.00 h) and tap water was available ad libitum. Blood samples were drawn at 3 h intervals along a 24 h span. The hormone levels were measured by RIA kits, plasma lipids by photometric method. The results were evaluated by cosinor method. The presence of a circadian rhythm of T3 and B was found in control rats. The starvation resulted in changed circadian rhythm of T3 with lower values of mesor and amplitude, and while acrophase shifted from 14.48 to 2.12. In addition, the starvation induced circadian rhythm of T4 with acrophase at 1.00. The circadian rhythm of B showed significantly higher values of mesor and amplitude, while acrophase shifted from 17.42 to 4.06. The concentration of lipids was changed in the animals deprived of food as compared with controls.

Serum ferritin, iron and transferrin in women with thyrotoxic Graves' disease before and after methimazole treatment

We investigated iron metabolism in 47 women with thyrotoxic Graves' disease. Serum iron, ferritin, transferrin, triiodothyronine and thyroxine concentrations were RIA measured before and after methimazole treatment when patients became euthyroid. The control group consisted of 52 healthy women. We noted that serum ferritin levels and the ferritin to transferrin ration were significantly lower while the iron to ferritin ratio was higher in patients before and after methimazole therapy. Iron concentration as well as the iron to transferrin and the iron to thyroid hormone ratios were decreased only before treatment.