Rhythm or rate control strategy in CRT recipients with long-standing persistent atrial fibrillation - preliminary results of the PilotCRAfT study

Funding Acknowledgements

Type of funding sources: Public Institution(s). Main funding source(s): National Institute of Cardiology in Warsaw Statutory Grant

Background

The presence of atrial fibrillation (AF) in cardiac resynchronization therapy (CRT) recipients is common and AF is a marker of poorer CRT response. The negative influence of AF on CRT efficacy is mediated mainly by the drop of the effectively captured biventricular paced beats percentage (BiVp%) which should exceed 95-98% to warrant good CRT response.  Sinus rhythm (SR) restoration may improve CRT efficacy which in turn may protect AF recurrence. However, there is lack of randomized studies comparing rhythm and rate control strategies in these patients.

Purpose

The purpose of the Pilot-CRAfT study (NCT01850277) was to compare the efficacy of rhythm vs rate control strategy in CRT patients with long-standing persistent or permanent atrial fibrillation.

Methods

The study included patients with CRT and permanent or persistent AF lasting for ≥6 months, resulting in BiVp% <95%, who were randomly assigned to rhythm or rate control strategy. The rhythm control strategy comprised of external electrical cardioversion (EEC). The rate control strategy included pharmacotherapy and atrioventricular node ablation (AVNA) as needed. Both of the study arms received amiodarone. The follow-up lasted 12 months. The primary endpoint was the 12-month BiVp%. The patients underwent ECHO, cardiopulmonary test, quality of live (QoL) and clinical outcomes assessment.  

Results

The study included 43 CRT patients (97,7% males) aged 68,4 (SD: ±8,3) years with mean BiVp% 82,4% ±9,7% at baseline. The mean duration of AF paroxysm was 25 ±19 months. The mean baseline left ventricular ejection fraction (LVEF), left atrium area and maximal oxygen uptake (VO2max) were: 30 ±8%, 33 ±7 cm2, 14 ±5 mL/(kg*min), respectively. The EEC was performed in 19 out of 22 patients assigned to the rhythm control arm. The immediate success rate of EEC was 58%. 42% of  the rhythm control arm patients remained in SR after 12 months. In the rate control group 1 person underwent AVNA and in 1 patient spontaneous SR resumption was observed. After 12 months there was significant BiVp% increase in both the rhythm and the rate control arms (98,1 ±2,3 vs 96,3 ±3,9%, respectively. The BiVp% differences between the groups were not significant (P = 0,093). However, in the per protocol analysis, the rhythm control group had greater LVEF after 12 months as opposed to the rate control arm (36,8% vs 29,9% respectively, P = 0,039). The LVEF raised significantly in the rhythm control group (ΔLVEF 5,0 (95%CI: 1,54; 8,46)). No significant differences between the groups in the VO2max, QoL, clinical and safety end-points were noticed.

Conclusions

Structured follow-up of CRT patients with long-standing persistent or permanent AF leads to significant BiVp% increase exceeding 95%. The rate control strategy did not improve CRT effectivness, irrespective of high BiVp%. However limited in the efficacy, the rhythm control strategy may improve CRT outcome in these patients, resulting in LVEF increase.

P429The efficacy of electrical cardioversion of long-standing persistent or permanent atrial fibrillation in cardiac resynchronization therapy recipients

Funding Acknowledgements

Institute of Cardiology statutory grant (grant no.: 2.30/VII/13)

Background

Atrial fibrillation (AF) and heart failure (HF) often co-exist and influence each other. The presence of AF is often regarded as a marker of HF severity.  Moreover, AF in cardiac resynchronization therapy (CRT) recipients hinders the CRT effectiveness in HF treatment by the reduction of the percentage of biventricular paced beats (BiVp%). Sinus rhythm (SR) restoration makes CRT more effective in HF treatment which may protect AF recurrence.

Purpose

To establish the effectiveness of electrical external cardioversion (EEC) in CRT patients with long-standing persistent AF or permanent, pre-treated with amiodarone.

Methods

The population of the study comprised of the Pilot-CRAfT study participants (NCT01850277), that is patients with CRT, long-standing persistent or considered as permanent AF and BiVp ≤ 95% who were randomly assigned to the "rhythm control" or the "rate control" strategy. The inclusion criteria included an AF paroxysm lasting at least 6 months. Both treatment arms received amiodarone beginning with the loading dose. Subsequently, patients assigned to the rhythm control strategy underwent electrical cardioversion. Rate control strategy included pharmacotherapy and atrioventricular node ablation, as needed. The follow up visit was performed 3 months after the enrolment visit. The EEC effectiveness, an AF recurrence within the 3 month period, BiVp% changes, the EEC parameters  and the EEC related complications were analysed.

Results

Out of 48 participants enrolled in the Pilot-CRAfT study, 25 patients were assigned to the rhythm control arm. The mean age of the rhythm control arm patients was 69,5 years , the mean left ventricular ejection fraction was 30,6% , the mean left atrium diameter was 53 mm and the median duration of persistent AF was 16 months. SR was obtained in 12 out of 20 (60%) patients who underwent the EEC . On the 3 month visit 8 patients remained in SR (40%). In patients with an AF paroxysm lasting less than 1 year the success rate was 100% vs 50% in the AF lasting 1 year at least (p = 0,11 ). After 3 months, SR remained in 100% vs 25% of patients, respectively (p =0,015.).  The effectiveness of anterior-posterior EEC electrodes placement was 20% and it was 71% for the anterior-lateral patch location . The EEC resulted in significant BiVp% rise - also in the whole intention-to-treat (ITT) group:  88,58%  before the EEC vs 96,68% after the EEC  (p = 0,002). No severe adverse events of the EEC were observed.

Conclusions

The electrical cardioversion of persistent atrial fibrillation lasting more than 6 months in patients with severe HF and treated with CRT is characterised by modest success rate, even after the amiodarone pre-treatment. However, the ECC ensures significant rise in BiVp% close to 97%, even in the whole EEC group based on the ITT principle. The AF paroxysm duration <1 year and the anterior-posterior patch placement may ensure better EEC efficacy in this group of patients.

Socio-demographic and lifestyle determinants of the micronutrients status during pregnancy

Key messages

In the case of a high proportion of the women the intake of majority of the analyzed micronutrients was below recommendations for the pregnancy period. More effort should be taken to educational programs and interventions that focus on healthy diet recommendations during pregnancy.

Synthesis of fluorescein by a ship-in-a-bottle method in different zeolites

Composites consisting of fluorescein (F) entrapped inside various zeolite structures (i.e. FAU, LTL, MFI, and LTA) were prepared by catalytic synthesis of the dye from its precursors (phthalic anhydride and resorcinol) adsorbed in the zeolites.

Proton conductivity of imidazole entrapped in microporous molecular sieves

Novel zeolite–imidazole composites as efficient and steady proton conductors.

Comparison of antifungal activity of extracts from different Juglans regia cultivars and juglone

This study discusses the similarities and differences between the antifungal activity of extracts from walnut green husks of Lake, Koszycki, UO1, UO2 and non-grafted cultivars as well as juglone against the plant pathogenic fungi such as Alternaria alternata, Rhizoctonia solani, Botrytis cinerea, Fusarium culmorum, Phytophthora infestans as well as Ascosphaera apis causing chalkbrood disease in honey bees. The obtained data show that the antifungal activities of the extracts do not always depend on the antifungal activity of juglone, and that they can be modulated by their other components. This fact allows us to conclude that juglone is not the only component of walnut green husk extracts which is responsible for the inhibition of mycelial growth. Phenolic compounds were found to be responsible for activity of the extracts and they can modify antifungal activity of juglone.

Maternal smoking decreases antioxidative status of human breast milk

OBJECTIVE

To evaluate the influence of maternal smoking on antioxidative capacity and intensity of oxidative damage in breast milk.

STUDY DESIGN

The study group (n=30) was comprised of postpartum women who declared smoking more than five cigarettes per day during pregnancy and lactation (confirmed by the urinalysis of cotinine concentration), and their newborns. Control group included 29 non-smoking postpartum women and their newborns. Colostrum samples were collected on the 3rd day after delivery and breast milk samples between the 30th and the 32nd day after delivery. Morning maternal and neonatal urine samples were obtained on the day of the mature milk sampling. Isoprostane concentrations in colostrum/mature milk and urine were determined immunoenzymatically. Total Antioxidant Status (TAS) of colostrum/breast milk was determined by Rice-Evans and Miller method.

RESULT

Colostrum TAS in smokers was significantly lower than in non-smokers (P=0.006). In both groups, the TAS of mature milk was higher compared with colostrum, but significant differences were observed amongst smokers only (P=0.001). In smokers the isoprostane concentration of mature milk was significantly higher than the colostrum concentration (P=0.001). Significant inverse correlation between maternal urinary isoprostane concentration and the TAS of mature breast milk was observed in smokers (R=-0.525, P=0.023), but not in non-smokers (R=0.161, P=0.422).

CONCLUSION

This study revealed that maternal smoking triggers harmful effects on an infant by impairing pro-oxidant-antioxidant balance of breast milk.

The effect of exogenous apelin on the secretion of pancreatic juice in anaesthetized rats

Apelin is known to stimulate cholecystokinin (CCK) and inhibit insulin release, however the mechanisms on pancreatic secretion remain unclear. The present study aimed to determine the expression of apelin and apelin receptor in the pancreas by immunofluorescence studies and the effect of exogenous apelin on the secretion of pancreatic juice in anesthetized rats. Pancreatic-biliary juice (P-BJ) was collected from Wistar rats treated with apelin (10, 20 and 50 nmol/kg b.w., boluses given every 30 min intravenously or intraduodenaly). The same apelin doses were administered to rats subjected to intraduodenal tarazapide, capsaicin or vagotomy. Pancreatic blood flow was measured by a laser doppler flowmeter. Direct effects of apelin were tested on dispersed acinar cells. Apelin receptor was expressed on acinar cells, pancreatic duct and islets cells, whereas apelin in pancreatic acini, but not in the islets. Intravenous apelin decreased P-BJ volume, protein and trypsin outputs in a dose-dependent manner. In contrast, intraduodenal apelin stimulated P-BJ secretion. Pharmacological block of mucosal CCK(1) receptor by tarazepide, vagotomy and capsaicin pretreatment abolished the effects of intravenous and intraduodenal apelin on P-BJ volume, protein and tryspin outputs. Apelin decreased the pancreatic blood flow. Apelin at 10(-6) M increased the release of amylase from non-stimulated and CCK-8-stimulated acinar cells. In conclusion, apelin can affect the exocrine pancreas through a complex mechanism involving local blood flow regulation and is driven by vagal nerves.

Intestinal MMC-related electric fields and pancreatic juice control the adhesion of Gram-positive and Gram-negative bacteria to the gut epithelium--in vitro study

The adhesion of six different Lactobacillus and Lactococcus and three pathogenic Escherichia and Salmonella strains was studied using Caco-2 cell line. In this in vitro model system the influence of weak electric field (EF) on bacterial adhesion was tested. The EF source was the in vitro reconstruction of spiking potentials recorded in the duodenum of a healthy calf during one myoelectrical migration complex (MMC) cycle. The ability to adhere to Caco-2 cells of bacteria belonging to two groups, Gram-positive lactobacilli and lactococci, and Gram-negative Escherichia and Salmonella differed considerably. The pathogenic bacteria adhered better to well-differentiated Caco-2 cells whereas lactobacilli and lactococci displayed better adhesion to non-differentiated Caco-2 cells. In the presence of MMC-related EF an increased adhesion of Lactobacillus and Lactococcus but not of Salmonella enterica s. Enteritidis and E. coli 269 to Caco-2 cells was observed. Two later strains adhered even less in the presence of EF. The same tendency was found in the presence of pancreatic juice in a cell medium. In conclusion, the myoelectric component of the small intestinal motility, the MMC-related EF, and pancreatic juice may increase the ability of lactic acid bacteria to adhere to GI epithelial cells, creating better environmental conditions for colonization of the intestine and competition with Gram-negative pathogens.

Coexpression of human chorionic gonadotropin beta subunit and its receptor in nontrophoblastic gynecological cancer

A considerable number of biochemical and physiologic studies evaluate the roles of gonadotropins in carcinogenesis. Latest reports show that human chorionic gonadotropin (hCG), and especially its beta subunit, are secreted by a variety of malignant tumors of different origin. However, the mechanism of hCG action and its role in tumor development is not known yet. This study, with the help of reverse transcription-polymerase chain reaction and immunohistochemistry, is an attempt to document the molecular presence of the hCGβ and luteinizing hormone/hCG receptor (LH/hCGR) in the ovarian, endometrial, and uterine cervix cancer tissues. The LH/hCGR, coexpressed with hCGβ, may act as a potential mediator of hCG action in nontrophoblastic gynecological cancers

Obestatin stimulates the secretion of pancreatic juice enzymes through a vagal pathway in anaesthetized rats - preliminary results

Obestatin is a 23 amino acid peptide derived from the preproghrelin precursor, and originally purified from the rat stomach mucosa. It was shown that obestatin may counteract the effects of its sister peptide, ghrelin, on food intake and gastrointestinal motility but the other roles in controlling the gastrointestinal function remain unknown. The aim of the present study was to determine the influence of exogenous obestatin on the secretion of pancreatic juice. In anesthetized male Wistar rats the external jugular vein was catheterized, and the common biliary-pancreatic duct was cannulated with polyethylene tubing for collection of pancreatic-biliary juice (P-BJ). Obestatin boluses (30, 100 and 300 nmol/kg b. wt.) were injected intravenously or intraduodenally every 30 min. Obestatin was also administered in vagotomized (subdiaphragmatic vagotomy) rats. In the examined rats, obestatin intravenous and intraduodenal boluses did not affect the P-BJ volume. On the other hand, obestatin boluses increased the protein output and trypsin activity. Vagotomy abolished the effects of exogenous obestatin administration. In conclusion, the present study demonstrates for the first time that exogenous obestatin may stimulate the secretion of pancreatic juice enzymes. The effect is dose-dependent and requires intact vagal supply.

Donor–origin cell engraftment after intraosseous or intravenous bone marrow transplantation in a rat model

We compared the effects of intraosseous BMT with those of standard i.v. BMT on the efficacy on donor-cell engraftment into the BM and lymphoid organs across an MHC barrier in rats. Twenty-four intraosseous and 24 i.v. BMTs were performed from 48 ACI (RT1(a)) donors to 48 Lewis (RT1(l)) recipients. Each transplant group received either intraosseous or i.v. BMT. Groups I and II served as controls without immunosuppression (n=16); groups III and IV received cyclosporine monotherapy (n=16); and V and VI received alphabeta-TCR monoclonal antibody and cyclosporine A (alphabeta-TCR/CsA) for 7 days (n=16). In each group, four rats received 35 x 10(6) transplanted bone marrow cells (BMCs) and four received 70 x 10(6) cells. All animals survived without GVHD. Mean (+/-s.d.) donor-cell engraftment into BM of recipients after intraosseous BMT was 7.9% (+/-1.3%) in recipients receiving alphabeta-TCR-CsA and 70 x 10(6) BMCs, and 4.2% (+/-1.4%) in recipients after i.v. transplantation. The seeding efficacy of donor cells into lymphoid tissue was greater after intraosseous BMT and alphabeta-TCR-CsA than after standard i.v. transplantation. In our model, intraosseous BMT facilitated donor-cell engraftment under short-term immunodepletive alphabeta-TCR/CsA protocol, which resulted in a temporary state of immune unresponsiveness.

The ghrelin pentapeptide inhibits the secretion of pancreatic juice in rats

Ghrelin, a 28 amino acids polypeptide was recognized as an endogenous ligand for the growth hormone secretagogue receptor. It turned out that the entire sequence of ghrelin is not necessary for performing the above-mentioned functions. It was suggested that 5 residues (Gly-Ser-Ser(n-octanoyl)-Phe, pentaghrelin) constituted functionally active part of the full-length polypeptide. Ghrelin-28 was found to inhibit pancreatic enzyme output in rats, though the effect of pentaghrelin was not studied so far. The study aimed to determine the involvement of pentaghrelin in pancreatic juice secretion in anaesthetized rats. Male Wistar rats (220 +/- 20 g body weight, b. wt.) were anesthetized, the external jugular vein and common biliary-pancreatic duct were cannulated. Pentaghrelin boluses (i.v., 1.2, 12, and 50 nmol kg(-1) b. wt.) were injected every 30 min with or without CCK-8 infusion, duodenal mucosal CCK(1) receptor blockade with tarazepide, vagotomy and capsaicin pretreatment. Pentaghrelin boluses reduced the volume of pancreatic-biliary juice, protein and trypsin outputs both under basal and CCK-8-stimulated conditions in a dose-dependent manner. However, exogenous pentaghrelin failed to affect the pancreatic secretion in rats subjected to vagotomy, capsaicin deactivation of afferents or pretreatment with Tarazepide. In conclusion, pentaghrelin may control exocrine pancreas secretion by affecting duodenal neurohormonal mechanism(s) involving CCK and vagal nerves in rats.

Pancreatic secretion differs according to the genotype of growing pigs

The objective of this study was to investigate the secretion of pancreatic enzymes and antibacterial activity in weaned pigs of three pure breeds, Pietrain, Duroc and Polish synthetic line 990, to look for eventual differences related to the genotype. Six male pigs of each breed, about 24 kg mean body weight, were equipped with chronic pancreatic duct catheters and duodenal cannulas to assess pure pancreatic juice, and jugular vein catheters for blood withdrawal. Pancreatic juice was collected before and after the morning feeding. Protein output and enzyme activities revealed two distinct profiles: strong manifestation of the prandial phase in Pietrain and line 990 pigs, and weak manifestation in Duroc. The antibacterial activity did not follow the enzyme kinetics, and it was the strongest in pancreatic juice from Pietrain pigs. Postprandial insulinaemia was reduced in the order of: line 990>Pietrain>Duroc. A slight (not significant) tendency towards a reduction of leptin after feeding in synthetic line 990 corresponded with elevated secretion of pancreatic enzymes and plasma insulin. The presented results suggest that the prandial secretion of pancreatic juice differs according to genotype, and the differences may be in part related to release of insulin.

The evaluation of lysozyme concentration and peroxidase activity in non-stimulated saliva of patients infected with HIV

PURPOSE

The aim of the study was the comparison of lysozyme concentration and peroxidase activity in mixed, non-stimulated saliva of HIV-positive patients and healthy subjects.

MATERIAL AND METHODS

The study was carried out in the group of 37 patients infected with HIV. The control group comprised of non-infected individuals, counterpart of the examined group. Mixed non-stimulated saliva, collected using expectoration method in the amount of 3-5 ml 2 hours after meal, was used for the study. Saliva samples were centrifuged, divided into portions 200 microl each, and stored at -80 degrees C. Peroxidase activity was determined using the method by Mansson-Rahemtull et al. Lysozyme concentrations were determined with the use of radial immunodiffusion method, ready-made kits (Human NL Nanorid plate--The Binding Site Ltd., UK).

RESULTS

Higher concentrations of lysozyme as well as peroxidase activity were observed in the group of patients with HIV as compared to the control group, and they were 35.08 microg/ml, 46.74 IU/1, 21.3 microg/ml, 37.73 IU/l, respectively. The difference was statistically significant only in case of peroxidase activity.

CONCLUSIONS

1. HIV infection triggers immune mechanisms, that are manifested by the increase in salivary enzymes responsible for local non-specific resistance. 2. The immunological resistance decrease, manifested by the drop of the absolute number of CD4 lymphocytes T, is compensated by the increase in lysozyme concentration and peroxidase activity in non-stimulated saliva of HIV-positive patients.

The saliva immunology mechanisms and periodontal status in HIV infected subjects

PURPOSE

The aim of this study was the evaluation of connection between parodontium determined by using GI and PBI indexes and specific immunity status and non-specific in HIV infected group and in control group.

MATERIAL AND METHODS

The study was carried out in the group of 37 patients infected with HIV. Mixed non-stimulated saliva was used for the study. Peroxidase activity was determined using the method by Mansson-Rahemtull. Lysozyme and A, G, M antibodies concentrations were determined with the use of radial immunodiffusion method. The concentration of lactoferrin was determined by using ELISA method. The clinical state of parodontium estimated by means of GI and PBI evaluating quality changes in the gum.

RESULTS

Deterioration of the immunological status of subjects was accompanied by the increase of the values of GI and PBI. The strong negative correlation between GI and PBI and the concentration of lactoferrin and positive activity of the peroxidase in the whole examined population was determined. In the infected group the correlation between the status of gingiva expressed by GI and concentration or activity of examined enzymes and immunoglobulins was not ascertained.

CONCLUSIONS

1. HIV infection is connected to worsening of paradontium status expressed by values of GI and PBI indexes. 2. Paradontium status correlated positively with immunological status of HIV positive subjects. 3. In HIV infected group, no connection between number of IgA, IgG, IgM, concentration of lysozyme, lactoferrin, activity of peroxidase and paradontium status was observed.

Chromatographic separation of chlorophenoxy acid herbicides and their radiolytic degradation products in water samples

HPLC procedure for simultaneous determination of chlorophenoxy acid herbicides and their radiolytic degradation products in waters is described with the use of octadecylsilica column and spectrophotometric detection at 280 nm. The satisfactory separation was achieved with a mobile phase of pH 2.5 consisting of 43.7 mM acetic acid with 40% (v/v) acetonitrile. Limit of detection values for herbicides and phenol derivatives were in the range of 19-41 microg/l and 10-60 microg/l, respectively. The developed method was applied for monitoring the effectiveness of radiolytic degradation of herbicides. Studies of products of gamma-radiolysis of 2,4-dichlorophenol have shown that the efficiency of this process is affected by the presence of naturally occurring scavengers of gamma-radiation such as carbonates or nitrates.

Specific dose-dependent effects of ethane 1,2-dimethanesulfonate in rat and mouse Leydig cells and non-steroidogenic cells on programmed cell death

The mechanism by which ethane 1,2-dimethanesulfonate (EDS) selectively kills Leydig cells is poorly understood. To characterize further the cell-specific actions of EDS, we studied biochemical and morphological changes during apoptosis in different Leydig cell and non-steroidogenic cell models. Rat testicular and H540 tumor Leydig cells were killed by 1-2 mM EDS, whereas 20 mM EDS were required for MA-10 cells. This higher concentration of EDS was also necessary for activation of apoptosis in non-steroidogenic Chinese hamster ovary cells, whereas COS-1 monkey kidney cells were resistant. These variable effects of EDS on apoptosis were independent of new protein synthesis and, interestingly, could be delayed by co-incubation with dibutyrl cyclic AMP. Along with cell death, we also observed chromosomal fragmentation and other hallmarks indicative of apoptosis as evidenced by DNA laddering and fluorescent microscopy. Time-lapse photography with a confocal microscope showed that the time of onset, duration and even the sequence of apoptotic events between individual H540 cells was heterogeneous. When the dose of EDS was gradually increased from 2 to 10 mM, the proportion of cells showing normal apoptotic features gradually decreased. Intriguingly, treatment with 10 mM EDS did not result in death for most cells and was marked by an absence of DNA laddering and ultrastructural features of apoptosis and necrosis. However, incubation with 20 mM EDS resulted in necrosis.These results demonstrated that the effects of EDS on cell survival are not specific to Leydig cells, that different cell types have different sensitivities to EDS and that stimulation of the cAMP pathway may mitigate EDS action. The data obtained with H540 cells further revealed that EDS can induce two types of programmed cell death.

Distribution of the DAZ gene transcripts in human testis

Involvement of variety of genes, especially located on Y chromosome, is critical for the regulation of spermatogenesis. In particular, fertility candidate genes such as deleted in azoospermia (DAZ) are believed to have important function in sperm production, since DAZ is frequently deleted in azoospermic and severy oligozoospermic men. The role of the DAZ gene is supported by its exclusive expression in the testis and by its deletion in about 10% of azoospermic and severely oligozoospermic patients. The distribution of DAZ transcripts in seminiferous epithelium of human testis is reported in the present study. The use of Adobe Photoshop and Scion Image softwares allowed for semi-quantitative analysis of in situ RT-PCR (ISRT-PCR) results. The intensity of ISRT-PCR product's fluorescence was different within individual seminiferous tubules. It was clearly shown by using the pseudocolour scale and transforming the intensity of the fluorescence into levels of greyscale images. The more intense fluorescence characterised single spermatogonia and those organized in small groups inside separate tubules. The most intense accumulation of DAZ mRNA was observed in spermatogonia.

Expression of beta-human chorionic gonadotropin in ovarian cancer tissue

The purpose of the present investigation was to determinate expression of human chorionic gonadotropin gene in ovarian cancer tissue. The study included 15 patients with epithelial ovarian carcinoma. The expression of mRNA hCGbeta was determinated by the RT PCR method and the distribution of the hormone in study tissue was analyzed immunohistochemicaly. In all 15 study specimens of the ovarian carcinoma tissue the active hCGbeta gene was found, whereas noncancerous tissue demonstrated lack of the hormone expression. Thus, the study clearly shows that the expression of hCGbeta is the feature of ovarian cancer tissue.

Influence of cycloheximide on apoptosis in CHO cells, induced by ethane 1,2-dimethanesulphonate (EDS)

Ethane 1,2-dimethanesulphonate (EDS) causes apoptotic death of Leydig cells. Additionally, EDS causes damage of Chinese Hamster Ovary (CHO) cells but the occurrence of apoptosis is not such plentiful. The present study tested whether the inhibition of protein synthesis by cycloheximide (CHX) would influence apoptosis of CHO cells, induced by EDS. The study compounds induced morphological changes in CHO cell typical for apoptosis. An active form of caspase-9 and an alternation of mitochondrial transmembrane potential were also observed. In our study, a more cumulative effect of the CHX and EDS on apoptosis was observed, when both compounds were simultaneously employed. The obtained results indicated that synthesis of antiapoptotic proteins plays a very important role in the inhibition of apoptosis.

Human chorionic gonadotropin-beta in endometrium cancer tissue

PURPOSE

Determination of the correlation between expression of human chorionic gonadotropin mRNA and serum free hCGb immunoreactivity in endometrial cancer tissue.

METHODS

The study included 56 patients with endometrial carcinoma Stages IB-III. The expression of mRNA hCGbeta was determined by the RT PCR method in 18 cases of cancerous and precancerous tissues. The serum-free hCGbeta immunoreactivity was analyzed by sequential immunometric assay in all patients.

RESULTS

In 15 study specimens of endometrial carcinoma tissue mRNA of hCGbeta was detected. Also in endometrial atypical hyperplasia, expression of hCGbeta was found. Noncancerous tissue demonstrated lack of the hCGbeta transcript. The serum immunoreactivity in the endometrial cancer group was detectable in 86% of cases. There were no significant differences between FIGO stages and grading.

CONCLUSION

The results of the present study confirmed the presence of active genes of hCGbeta in endometrial cancer tissue, even in precancerous changes. The serum immunoreactivity of free hCGbeta is a less common feature and is not linked with tumor stage or grade in endometrial cancer patients.

The effect of some parameters of milk protein coagulation on the transfer of a commercial enzymatic preparation to cheese grain

The effect of coagulation conditions of raw, skimmed and pasteurized milk on the transfer of commercial enzymatic preparations (Chymogen, Fromase and Hala) to cheese grain, was studied. It was found that the transfer degree of the above preparations was dependent on some coagulation parameters such as milk acidity and temperature. The duration of cheese grain retention did not have a significant effect on the transfer of the analyzed preparations.

Applaying of high pressure to yoghurt preservation

Effects of the high pressure treatment in the range of 200 - 1000 MPa/15 min., at the room temperature, on survivability of Streptococcus thermophilus and Lactobacillus delbrueckii ssp. bulgaricus was investigated. Sensorial characteristics of yoghurt was conducted by a panel of experts. Influence of yoghurt acidity on the effect of pressurization was also determined. In the experiment, we also attempted to extend shelf-life of yoghurt, subjecting it to the pressure of 550 MPa/15 min. Pressure treated yoghurt was stored for 4-weeks at room and refrigerated temperature; every seven days microbial number, acidity and sensory attributes of the beverage was determined. Addition of fruit jam on the effect of pressurization was also checked. Survivability of microorganisms depends on the value of pressure used in the experiment. The research displayed that yoghurt acidity did not influence the effect of pressurization. During 4-weeks of storage, yoghurt processed at 550 MPa maintained its beneficial characteristics longer compared to the non-pressurized one. Addition of fruit jam beneficially affected consistency of the pressure treated yoghurt. The conducted studies showed that there was possibility of preserving yoghurt by the method of high pressures. Thus, to preserve yoghurt, the complete inactivation of microflora is not necessary.

[Disturbances of glucose metabolism in epilepsy and other neurodegenerative diseases]

Disturbances of glucose metabolism in epilepsy and other neurodegenerative diseases. Impairment of glucose and acetyl-CoA metabolism is a characteristic feature of several degenerative brain diseases. Presented paper provides experimental evidences that NO, aluminum and thiamine deficiency result in concordant disturbances in acetyl-CoA campartmentalisation as well as in nonquantal and quantal acetylcholine release in rat brain nerve terminals. Our findings indicate that simultaneous depression of acetyl-CoA synthesis and its increased utilisation for acetylcholine synthesis in the presence of neurotoxic factors is likely to make brain cholinergic neurones particularly prone to neurodegeneration.

A novel calcium-regulated membrane guanylate cyclase transduction system in the olfactory neuroepithelium

This report defines the identity of a calcium-regulated membrane guanylate cyclase transduction system in the cilia of olfactory sensory neurons, which is the site of odorant transduction. The membrane fraction of the neuroepithelial layer of the rat exhibited Ca(2+)-dependent guanylate cyclase activity, which was eliminated by the addition of EGTA. This indicated that the cyclase did not represent a rod outer segment guanylate cyclase (ROS-GC), which is inhibited by free Ca(2+). This interpretation was supported by studies with the Ca(2+) binding proteins, GCAPs (guanylate cyclase activating proteins), which stimulate photoreceptor ROS-GC in the absence of Ca(2+). They did not stimulate the olfactory neuroepithelial membrane guanylate cyclase. The olfactory neuroepithelium contained a Ca(2+) binding protein, neurocalcin, which stimulated the cyclase in a Ca(2+)-dependent fashion. The cyclase was cloned from the neuroepithelium and was found to be identical in structure to that of the previously cloned cyclase termed GC-D. The cyclase was expressed in a heterologous cell system, and was reconstituted with its Ca(2+)-dependent activity in the presence of recombinant neurocalcin. The reconstituted cyclase mimicked the native enzyme. Immunocytochemical studies showed that the guanylate cyclase coexists with neurocalcin in the apical region of the cilia. Deletion analysis showed that the neurocalcin-regulated domain resides at the C-terminal region of the cyclase. The findings establish the biochemical, molecular, and functional identity of a novel Ca(2+)-dependent membrane guanylate cyclase transduction system in the cilia of the olfactory epithelium, suggesting a mechanism of the olfactory neuroepithelial guanylate cyclase regulation fundamentally distinct from the phototransduction-linked ROS-GC.

Three dimensional atomic model and experimental validation for the ATP-Regulated Module (ARM) of the atrial natriuretic factor receptor guanylate cyclase

Atrial natriuretic factor (ANF) receptor guanylate cyclase (ANF-RGC) is a single chain transmembrane-spanning protein, containing both ANF binding and catalytic activities. ANF binding to the extracellular receptor domain activates the cytosolic catalytic domain, generating the second messenger cyclic GMP. Obligatory in this activation process is an intervening transduction step, which is regulated by the binding of ATP to the cyclase. The partial structural motif of the ATP binding domain of the cyclase has been elucidated and has been termed ATP Regulatory Module (ARM). The crystal structures of the tyrosine kinase domains of the human insulin receptor and haematopoietic cell kinase were used to derive a homology-based model of the ARM domain of ANF-RGC. The model identifies the precise configuration of the ATP-binding pocket in the ARM domain, accurately represents its ATP-dependent features, and shows that the ATP-dependent transduction phenomenon is a two-step mechanism. In the first step, ATP binds to its pocket and changes its configuration; in the second step, via an unknown protein kinase, it phosphorylates the cyclase for its full activation.

Effect of high pressure on some properties of lactic acid bacteria present in kefir

The aim of the work was to determine the effect of pressurization under 700 and 1000 MPa on the following: biochemical and antibacterial activity of individual strains of streptococci and lactobacilli, isolated from kefir inoculum, and of kefir microflora. After pressurization under 1000 MPa, the studied microorganisms lost their ability to inhibit the growth of the test strains, preserving the aroma-producing ability at the same time. The pressure of 1000 MPa caused also the changes in conformation of lactic acid, produced by the bacteria in skim milk culture. The changes in metabolism of the isolated bacteria, as being the result of pressurization under 700 MPa were dependent on the strain of microorganisms.

Detection of DAZ mRNA distribution in human testis using reverse transcription in situ PCR technique (RT-ISPCR)

Normal course of spermatogenesis reflects appropriate expression of specific genes in spermatogenic cells. In the present study, the localization of DAZ mRNA in human testis obtained from two fertile organ donors has been determined. It was established that DAZ mRNA is located in the germinal epithelium of seminiferous tubules. The most intensive accumulation of DAZ transcript was observed in primary spermatocytes. The results indicate that expression of DAZ gene begins in spermatogonia and that distribution of DAZ mRNA most likely correlates with the stage of the human seminiferous cycle.

Acute and chronic effects of aluminum on acetyl-CoA and acetylcholine metabolism in differentiated and nondifferentiated SN56 cholinergic cells

Mechanisms of preferential loss of cholinergic neurons in the course of neurodegenerative diseases are unknown. Therefore, we investigated whether differentiation-evoked changes in acetyl-CoA and acetylcholine metabolism contribute to the susceptibility of cholinergic neuroblastoma to cytotoxic effects of Al. In SN56 cells differentiated with retinoic acid and dibutyryl cAMP (DC), pyruvate utilization and acetyl-CoA content were lower and acetylcholine level higher than in nondifferentiated cells (NC), respectively. In DC Al and Ca accumulations were 50% and 100%, respectively higher than in NC. Acute Al addition caused inhibition, whereas its chronic application had no effect on pyruvate utilization both in NC and in DC. On the other hand, in both experiments, Al evoked a greater decrease of acetyl-CoA level in DC than in NC. Acute addition of Al depressed acetylcholine release from DC to two times lower values than in NC. On the other hand, chronic addition of Al increased ACh release from DC over twofold, being without effect on its release from NC. These findings indicate that higher accumulation of Ca, along with low levels of acetyl-CoA, could make DC more susceptible to neurotoxic inputs than NC. Excessive acetylcholine release, evoked by Al, is likely to increase acetyl-CoA utilization for resynthesis of the neurotransmitter pool and cause deficit of this metabolite in DC. On the other hand, NC, owing to lower Ca accumulation, slower ACh metabolism, and higher level of acetyl-CoA, would be less prone to these harmful conditions.

Three dimensional atomic model and experimental validation for the ATP-Regulated Module (ARM) of the atrial natriuretic factor receptor guanylate cyclase

Atrial natriuretic factor (ANF) receptor guanylate cyclase (ANF-RGC) is a single chain transmembrane-spanning protein, containing both ANF binding and catalytic activities. ANF binding to the extracellular receptor domain activates the cytosolic catalytic domain, generating the second messenger cyclic GMP. Obligatory in this activation process is an intervening transduction step, which is regulated by the binding of ATP to the cyclase. The partial structural motif of the ATP binding domain of the cyclase has been elucidated and has been termed ATP Regulatory Module (ARM). The crystal structures of the tyrosine kinase domains of the human insulin receptor and haematopoietic cell kinase were used to derive a homology-based model of the ARM domain of ANF-RGC. The model identifies the precise configuration of the ATP-binding pocket in the ARM domain, accurately represents its ATP-dependent features, and shows that the ATP-dependent transduction phenomenon is a two-step mechanism. In the first step, ATP binds to its pocket and changes its configuration; in the second step, via an unknown protein kinase, it phosphorylates the cyclase for its full activation.

Impairment of the rod outer segment membrane guanylate cyclase dimerization in a cone-rod dystrophy results in defective calcium signaling

Rod outer segment membrane guanylate cyclase1 (ROS-GC1) is the original member of the membrane guanylate cyclase subfamily whose distinctive feature is that it transduces diverse intracellularly generated Ca(2+) signals in the sensory neurons. In the vertebrate retinal neurons, ROS-GC1 is pivotal for the operations of phototransduction and, most likely, of the synaptic activity. The phototransduction- and the synapse-linked domains are separate, and they are located in the intracellular region of ROS-GC1. These domains sense Ca(2+) signals via Ca(2+)-binding proteins. These proteins are ROS-GC activating proteins, GCAPs. GCAPs control ROS-GC1 activity through two opposing regulatory modes. In one mode, at nanomolar concentrations of Ca(2+), the GCAPs activate the cyclase and as the Ca(2+) concentrations rise, the cyclase is progressively inhibited. This mode operates in phototransduction via two GCAPs: 1 and 2. The second mode occurs at micromolar concentrations of Ca(2+) via S100beta. Here, the rise of Ca(2+) concentrations progressively stimulates the enzyme. This mode is linked with the retinal synaptic activity. In both modes, the final step in Ca(2+) signal transduction involves ROS-GC dimerization, which causes the cyclase activation. The identity of the dimerization domain is not known. A heterozygous, triple mutation -E786D, R787C, T788M- in ROS-GC1 has been connected with autosomal cone-rod dystrophy in a British family. The present study shows the biochemical consequences of this mutation on the phototransduction- and the synapse-linked components of the cyclase. (1) It severely damages the intrinsic cyclase activity. (2) It significantly raises the GCAP1- and GCAP2-dependent maximal velocity of the cyclase, but this compensation, however, is not sufficient to override the basal cyclase activity. (3) It converts the cyclase into a form that only marginally responds to S100beta. The mutant produces insufficient amounts of the cyclic GMP needed to drive the machinery of phototransduction and of the retinal synapse at an optimum level. The underlying cause of the breakdown of both types of machinery is that, in contrast to the native ROS-GC1, the mutant cyclase is unable to change from its monomeric to the dimeric form, the form required for the functional integrity of the enzyme. The study defines the CORD in molecular terms, at a most basic level identifies a region that is critical in its dimer formation, and, thus, discloses a single unifying mechanistic theme underlying the complex pathology of the disease.