Oxidative Stress in Xenograft Mouse Model Exposed to Dendrimers Decorated Polydopamine Nanoparticles and Targeted Chemo- and Photothermal Therapy

Polydopamine (PDA)-based nanostructures are used for biomedical purposes. A hybrid drug nanocarrier based on a PDA decorated with polyamidoamine (PAMAM) dendrimers G 3.0 (DG3) followed by a connection with glycol (PEG) moieties, folic acid (FA), and drug doxorubicin (DOX) was used for combined chemo- and photothermal therapy (CT-PTT) of liver cancer. Oxidative stress plays a crucial role in the development of cancer, and PDA seems to have the ability to both donate and accept electrons. We investigated oxidative stress in organs by evaluating oxidative stress markers in vivo. In the liver, the level of reduced glutathione (GSH) was lower and the level of Trolox equivalent antioxidant capacity (TEAC) was higher in the group receiving doxorubicin encapsulated in PDA nanoparticles with phototherapy (PDA@DG3@PEG@FA@DOX + PTT) compared to the control group. The concentration of thiobarbituric acid reactive substances (TBARS) in livers, was higher in the group receiving PDA coated with PAMAM dendrimers and functionalized with PEG and FA (PDA@DG3@PEG@FA) than in other groups. Markers in the brain also showed lower levels of GSH in the PDA@DG3@PEG@FA group than in the control group. Markers of oxidative stress indicated changes in the organs of animals receiving PDA nanoparticles with PAMAM dendrimers functionalized with FA in CT-PTT of liver cancer under in vivo conditions. Our work will provide insights into oxidative stress, which can be an indicator of the toxic potential of PDA nanoparticles and provide new strategies to improve existing therapies.

Factors affecting fledglings survival in urban population of European blackbirds in Szczecin (NW Poland)

The first-year survival alters population growth rates and viability in birds, however this period remains the least-studied of the avian life stages. Here we present results of the 19 years of study of fledglings apparent survival of urban population of European blackbird Turdus merula in Szczecin (NW Poland). We checked for possible influence on survival of several factors, including parental traits, such as parental age, their previous breeding experience, natal brood size, presence of another brood in a given breeding season and the time gap between clutches of a particular pair. Moreover, we incorporate into our analysis fledging's hierarchy in the brood, its fledging time in the breeding season, temperature and precipitation during the first months of life. We also investigated changes in the apparent survival over 19 years. We found that the individual's hierarchy in the nest, and the day of fledging had the strongest influence on the apparent survival, with heavier birds fledged earlier in the season surviving better. Increase in parental age and previous breeding experience of the pair could result in enhanced survival. Surprisingly increased precipitation lowered fledglings' survival. During the 19 years of the study fledglings' apparent survival dropped about 10%.

Polydopamine-Based Material and Their Potential in Head and Neck Cancer Therapy-Current State of Knowledge

Head and neck cancers (HNC) are among the most common cancers in the world. In terms of frequency of occurrence in the world, HNC ranks sixth. However, the problem of modern oncology is the low specificity of the therapies used, which is why most of the currently used chemotherapeutic agents have a systemic effect. The use of nanomaterials could overcome the limitations of traditional therapies. Researchers are increasingly using polydopamine (PDA) in nanotherapeutic systems for HNC due to its unique properties. PDA has found applications in chemotherapy, photothermal therapy, targeted therapy, and combination therapies that facilitate better carrier control for the effective reduction of cancer cells than individual therapies. The purpose of this review was to present the current knowledge on the potential use of polydopamine in head and neck cancer research.

Gender bias in special issues: evidence from a bibliometric analysis

Even though the majority of psychologists are women, they are outnumbered by men in senior academic ranks. One reason for this representation bias in academia is that men favor other men in decision-making, especially when the stakes are high. We tested the possibility of such bias in a bibliometric analysis, in which we coded editors' and authors' gender in regular and special issues, the latter considered of higher scientific prominence. We examined all special issues from five prominent scientific outlets in the fields of personality and social psychology published in the twenty-first century. Altogether, we analyzed 1911 articles nested in 93 sets comprising a special issue and a neighboring regular issue treated as a control condition. For articles published in special (but not regular) issues, when there were more men editors, more men first-authored and co-authored the work. This pattern suggests how gender bias can be perpetuated within academia and calls for revising the editorial policies of leading psychology journals.

Oxidative Stress in Long-Term Exposure to Multi-Walled Carbon Nanotubes in Male Rats

Multi-walled carbon nanotubes (MWCNTs) serve as nanoparticles due to their size, and for that reason, when in contact with the biological system, they can have toxic effects. One of the main mechanisms responsible for nanotoxicity is oxidative stress resulting from the production of intracellular reactive oxygen species (ROS). Therefore, oxidative stress biomarkers are important tools for assessing MWCNTs toxicity. The aim of this study was to evaluate the oxidative stress of multi-walled carbon nanotubes in male rats. Our animal model studies of MWCNTs (diameter ~15-30 nm, length ~15-20 μm) include measurement of oxidative stress parameters in the body fluid and tissues of animals after long-term exposure. Rattus Norvegicus/Wistar male rats were administrated a single injection to the knee joint at three concentrations: 0.03 mg/mL, 0.25 mg/mL, and 0.5 mg/mL. The rats were euthanized 12 and 18 months post-exposure by drawing blood from the heart, and their liver and kidney tissues were removed. To evaluate toxicity, the enzymatic activity of total protein (TP), reduced glutathione (GSH), glutathione S-transferase (GST), thiobarbituric acid reactive substances (TBARS), Trolox equivalent antioxidant capacity (TEAC), nitric oxide (NO), and catalase (CAT) was measured and histopathological examination was conducted. Results in rat livers showed that TEAC level was decreased in rats receiving nanotubes at higher concentrations. Results in kidneys report that the level of NO showed higher concentration after long exposure, and results in animal serums showed lower levels of GSH in rats exposed to nanotubes at higher concentrations. The 18-month exposure also resulted in a statistically significant increase in GST activity in the group of rats exposed to nanotubes at higher concentrations compared to animals receiving MWCNTs at lower concentrations and compared to the control group. Therefore, an analysis of oxidative stress parameters can be a key indicator of the toxic potential of multi-walled carbon nanotubes.

Emotional framing in online environmental activism: Pairing a Twitter study with an offline experiment

As the consequences of anthropogenic climate change become more apparent, social media has become a central tool for environmental activists to raise awareness and to mobilize society. In two studies, we examine how the emotional framing of messages posted by environmental activists influences engagement and behavioral intentions toward environmental action. In the first study, tweets (N = 510k) of 50 environmental activists posted between November 2015 and December 2020 are examined to measure their emotional content and its relation to tweet diffusion. Environment-related tweets are found to be shared more the less they contain positive emotion and the more they contain negative emotion. This result supports the negativity bias on social media. In Study 2 (N = 200), we experimentally test whether negatively vs. positively framed environmental content leads to increased reported intent to engage with collective action, and whether mood mediates that link. We find both direct and indirect effects on reported climate action intentions when mood is used as a mediator. The negative mood resulting from seeing negative tweets makes participants more likely to report higher action intention (indirect effect)-congruent with Study 1. However, seeing negative tweets also makes participants less inclined to act (direct effect), indicating a suppression effect and the presence of other factors at work on the pathway between information and action intent formation. This work highlights the complex and multifaceted nature of this relation and motivates more experimental work to identify other relevant factors, as well as how they relate to one another.

“Make it Happen!”

Abstract. Verbs may be attributed to higher agency than other grammatical categories. In Study 1, we confirmed this hypothesis with archival datasets comprising verbs ( N = 950) and adjectives ( N = 2115). We then investigated whether verbs (vs. adjectives) increase message effectiveness. In three experiments presenting potential NGOs (Studies 2 and 3) or corporate campaigns (Study 4) in verb or adjective form, we demonstrate the hypothesized relationship. Across studies, (overall N = 721) grammatical agency consistently increased message effectiveness. Semantic agency varied across contexts by either increasing (Study 2), not affecting (Study 3), or decreasing (Study 4) the effectiveness of the message. Overall, experiments provide insights in to the meta-semantic effects of verbs – demonstrating how grammar may influence communication outcomes.

“Historia est magistra vitae”? The impact of historical victimhood on current conspiracy beliefs

Conspiracy beliefs constitute a propensity to attribute major events to powerful agents acting against less powerful “victims”. In this article we test whether collective victimhood facilitates conspiracy thinking. Study 1 showed that perceived group victimhood is associated with generic and group-specific conspiracy beliefs, but only for individuals who identify highly with their ingroup. Study 2 employed an experimental design to show that experimentally increased group victimhood leads to increased endorsement of conspiracy beliefs among high ingroup identifiers, but decreases endorsement of conspiracy beliefs among low identifiers. This effect was mediated by lack of trust towards outgroup members. Study 3 sought to replicate Study 2 in a different socio-political context. While Study 3 did not directly support the relationship between victimhood, group identification and conspiracy beliefs, an integrated meta-analysis of all three studies provides evidence for a significant interaction of victimhood and group identification in predicting conspiracy beliefs.

10Kin1day: A Bottom-Up Neuroimaging Initiative

We organized 10Kin1day, a pop-up scientific event with the goal to bring together neuroimaging groups from around the world to jointly analyze 10,000+ existing MRI connectivity datasets during a 3-day workshop. In this report, we describe the motivation and principles of 10Kin1day, together with a public release of 8,000+ MRI connectome maps of the human brain.

Traumatic Rift: How Conspiracy Beliefs Undermine Cohesion After Societal Trauma?

Collective traumas may often lead to deep societal divides and internal conflicts. In this article, we propose that conspiracy theories emerging in response to victimizing events may play a key role in the breakdown of social cohesion. We performed a nationally representative survey in Poland (N = 965) two years after the Smoleńsk airplane crash in which the Polish president was killed, together with 95 political officials and high-ranking military officers. The survey found that people endorsing conspiratorial accounts of the Smoleńsk catastrophe preferred to distance themselves from conspiracy non-believers, while skeptics preferred greater distance to conspiracy believers. We also examined the role of people’s belief in the uniqueness of in-group historical suffering as an important antecedent of both conspiracy thinking and hostility towards outgroups (conspiracy believers and non-believers).

Aging and Hypertension - Independent or Intertwined White Matter Impairing Factors? Insights From the Quantitative Diffusion Tensor Imaging

Aging disrupts white matter integrity, and so does continuous elevated blood pressure that accompanies hypertension (HTN). Yet, our understanding of the interrelationship between these factors is still limited. The study aimed at evaluating patterns of changes in diffusion parameters (as assessed by quantitative diffusion fiber tracking - qDTI) following both aging, and hypertension, as well as the nature of their linkage. 146 participants took part in the study: the control group (N = 61) and the patients with hypertension (N = 85), and were divided into three age subgroups (25-47, 48-56, 57-71 years). qDTI was used to calculate the values of fractional anisotropy, mean, radial and axial diffusivity in 20 main tracts of the brain. The effects of factors (aging and hypertension) on diffusion parameters of tracts were tested with a two-way ANOVA. In the right hemisphere there was no clear effect of the HTN, nor an interaction between the factors, though some age-related effects were observed. Contrary, in the left hemisphere both aging and hypertension contributed to the white matter decline, following a functional pattern. In the projection pathways and the fornix, HTN and aging played part independent of each other, whereas in association fibers and the corpus callosum if the hypertension effect was significant, an interaction was observed. HTN patients manifested faster decline of diffusion parameters but also reached a plateau earlier, with highest between-group differences noted in the middle-aged subgroup. Healthy and hypertensive participants have different brain aging patterns. The HTN is associated with acceleration of white matter integrity decline, observed mainly in association fibers of the left hemisphere.

The pathophysiology of intracerebral haemorrhage

Spontaneous intracerebral haemorrhage carries a high mortality rate and treatment of the disease raises more questions then answers. Mass effect, ischaemia and toxicity of blood components are responsible for brain tissue damage. Initially occurring disturbances of cerebral blood flow have a temporary character and do not play a key role in the pathology of intracerebral haematoma. Oedema formatting in the 24-48 hours after intracerebral bleeding is the result of multidirectional processes. The pathological mechanism that underlines it is the function of activation of systemic complement and cascade of coagulation. In the light of these findings, further clinical and experimental investigations should be focused on these factors.

The technique of inhalation anaethesia in experimental investigation in the rat

The rat is the most frequently used animal in scientific inquiry conducted for the purpose of advancing basic knowledge that may lead to an improvement in the results of treatment. Understanding of the pharmacological properties of inhalation anaesthetics, in combination with monitoring of their concentration in the inspired and end-tidal gas, together provide safe and precise control of the depth of the anaesthesia. However, accurate application of the inhalation method of anaesthesia requires special equipment for the delivery and effective scavenging of inhalation anaesthetics.

[Effects of thrombolysis on left and right ventricular diastolic function in patients after myocardial infraction. One-year follow-up]

It has been shown, that successful reperfusion of the infarctrelated artery by thrombolysis can prevent left ventricular (LV) dilatation and dysfunction. To date no study has shown the impact of thrombolytic therapy on LV and RV diastolic filling. The aim of the study was to assess the effects of thrombolysis on LV and RV diastolic inflow and systolic function of LV in patients (pts) after anterior myocardial infarction MI.

METHODS

Echocardiographic and Doppler-derived measurements of LV systolic function, RV and LV diameters and diastolic function at rest and after treadmill exercise test (TET) were assessed prospectively in 21 patients (pts) after MI treated with streptokinase and 10 pts treated without thrombolysis during one-year follow-up. They were compared with 31 age-matched controls.

RESULTS

LV and RV filling indices in both groups of pts after MI were impaired compared to controls but in pts without thrombolysis were more abnormal compared to pts treated with thrombolysis. Among several echocardiographic variables most consistent alteration was shortening of E-deceleration time of mitral as well as RV inflow, more abnormal in pts without thrombolysis. There was strong inverse relation between degree of impairment of diastolic variables and exercise capacity.

CONCLUSIONS

These data indicates beneficial effect of thrombolysis on RV and LV diastolic function in patients after AMI. E-deceleration was the most sensitive marker of diastolic dysfunction.

Characterization and sequence analysis of the replicator region of the novel plasmid pALC1 from Paracoccus alcaliphilus

The replicator region of a low-copy-number plasmid, pALC1, of Paracoccus alcaliphilus JCM 7364 was cloned in a form of the minireplicon pALC100 (3.6 kb). The host range of the minireplicon embraces several species of genus Paracoccus, as well as Agrobacterium tumefaciens, Rhizobium leguminosarum, and Rhodobacter sphaeroides (all belonging to alpha-Proteobacteria), but not Escherichia coli. The complete nucleotide sequence of the replicator region (2276 bp) revealed the presence of one complete open reading frame coding for the 28.4-kDa protein (RepA) with similarity to replication proteins of plasmid pSW500 of Erwinia stewartii and pVS1 of Pseudomonas fluorescens. The iteron-like region was identified upstream of the repA gene and consisted of two clusters of repeated sequences (17 bp long) separated by a putative DnaA box. Analysis of the predicted amino acid sequence of two adjacent incomplete ORFs suggests the localization of repA between genes involved in conjugation (traG) and partitioning (parA) within the pALC1 genome.

[Neurohumoral factors in hypertensive patients with and without left ventricular hypertrophy]

Increased pressure load and neurohumoral activation are main factors involved in pathomechanism of left ventricular hypertrophy (LVH) in hypertension (HT). To gain insight into the involvement of neurohumoral factors responsible for cardiac hypertrophy, plasma level of aldosterone (Aldo), plasma renin activity (PRA), insulin-like growth factor-1 (IGF-1), pro-endothelin-1 (pro-ET) and atrial natriuretic peptide (ANP) were measured in HT patients (pts) and compared between pts with and without LVH. Also relationships between neurohormones and LV mass index (LVMI), mean blood pressure (MBP) were assessed separately in HT pts with and without LVH. 121 HT patients (pts) of age 17-79 (mean 48 +/- 15.3) were divided into three groups: 1-53 pts with mild HT, 2-44 pts with moderate HT and 3-24 pts with severe HT. Each of the group was divided into pts with and without LVH further all HT pts were divided into two groups; with and without LVH. Control group consisted of 39 healthy normotensives. LV mass was assessed echocardiographically and plasma levels of IGF-1, PRA, Aldo, pro-ET, and ANP were measured by radioimmunoassay in each pts and controls. LVH was found in 35.8% pts with mild HT, in 68.18% pts with moderate HT and in 100% pts with severe HT. The level of all measured neurohormones were significantly higher in pts with LVH compared to pts without LVH (p < 0.001). In pts with LVH there was significant correlation between LVMI and IGF-1, PRA, Aldo, pro-ET-1 and ANP, contrary to pts without LVH in which such correlations was not found. In pts with LVH there was also significant correlation between MBP and IGF-1, PRA, ANP and pro-ET-1. Increased plasma level of PRA, Aldo, IGF-1, pro-ET-1 and ANP in HT pts with LVH and significant correlation between measured neurohormones and LVMI suggests their contribution to LVH in HT pts. Significant correlation between LVMI, MBP and IGF-1 level, PRA and ANP indicate interplay between hemodynamic and neuroendocrine factors in pathomechanism of LVH.

[The influence of 3-month treatment with molsidomine on structure, function and some neurohormonal parameters in patients with chronic heart failure treated with digoxin, diuretic and angiotensin converting enzyme inhibitors]

The aim of the study was to estimate the influence of long-term treatment with molsidomine on structure, systolic function and neurohormonal parameters in patients with chronic heart failure (CHF). Investigations were carried out in 30 patients (mean age 63.0 +/- 10.9) in NYHA class III and IV. The cause of CHF was: coronary artery disease in 60% of patients, hypertension in 20% and dilated cardiomyopathy in 20% of patients. Molsidomine was administrated in dose of 2 mg tid for 3 months. During the study the previous treatment with ACEI, diuretics and digitalis was maintained. Using echocardiographic method left atrial dimension (LA), left ventricular end diastolic (LVEDD) and end systolic diameter (LVESD), interventricular septum (IVSDD) and posterior wall end diastolic diameter (LVPWDD), ejection fraction (LVEF) and fraction of shortening (LVFS) were measured. Plasma level of atrial natriuretic peptide, endotelin, neuropeptide Y and aldosterone and plasma renin activity were estimated radioimmunologically. All echocardiographic and neurohormonal measures were performed 4 times: before therapy, after 3 days, 2 weeks and 3 months of treatment with molsidomine. We observed significant increase in LVEF, which at baseline was 33.8% and after 3 months 44.8% (p < 0.05). None of the other echocardiographic parameters nor any of neurohormonal factors changed significantly during the 3-months treatment with molsidomine.

[Comparative study to assess the efficacy and adverse effects of amlodipine and nifedipine retard in patients with stable exertional angina and hypertension]

The purpose of the study was to compare the antianginal and hypotensive efficacy and tolerability of 8 weeks of treatment with amlodipine taken once daily and nifedipine taken twice daily in patients with stable exertional angina pectoris and mild-to-moderate hypertension. Following a 2-week placebo run-in-period 13 patients were randomized to receive amlodipine (5 to 10 mg once daily) and 8 patients to receive nifedipine (20 or 40 mg twice daily) in an 8-week treatment phase. Antianginal efficacy was assessed with angina diares, investigators, and patients global evaluations and with treadmill exercise test during placebo run-in-period and after 8 weeks of the therapy. Amlodipine significantly reduced both weekly anginal attacks and consumption of glyceryl trinitrate tablets. This effect was more pronounced compared to efficacy of nifedipine. Exercise tolerance was also improved more markedly after amlodipine than after nifedipine treatment. Amlodipine treatment resulted in significant increase in total exercise time, increase the exercise time to angina onset, increase time to ST segment depression, decrease in ST segment depression, decrease in total duration of ST segment depression and decrease in duration of pain. In patients treated with nifedipine only favourable effect was significant decrease in total duration of ST segment depression, without significant changes of other examined parameters. Both drugs decreased blood pressure with no significant change in heart rate. No serious adverse events occurred in any patients during therapy with amlodipine as well as with nifedipine. The results of the study demonstrate that amlodipine has markedly better anti-anginal efficacy than nifedipine with respect to the most of the parameters examined. However both drugs showed comparable antihypertensive action and both were well tolerated by angina patients. The good anti-anginal and hypotensive efficacy and safety of amiodipine with once daily dosage regimen makes this drug an excellent choice of treatment for hypertensive patients with severe coronary artery disease.

[Relationship between systolic and diastolic function of the left ventricle in patients with impaired relaxation of the left ventricle without symptoms of heart failure. Attempt at quantitative estimation of diastolic function in the impaired relaxation stage]

Diastolic dysfunction of left ventricle appears very often in patients with coronary artery disease (CAD) and hypertension (HT) and is a main cause of heart failure in 30-40% of all cases. Relation between systolic and diastolic function of left ventricle (LV) is commonly known but not documented well enough. Moreover, no quantitative classification of diastolic dysfunction is still available.

AIM OF THE STUDY

To find out the relations between the parameters of systolic and diastolic function of LV in patients with CAD or HT with impaired relaxation of LV without symptoms of heart failure and to make up the quantitative classification of diastolic dysfunction in the stage of impaired relaxation of LV.

METHODS

Investigations were carried out in 57 patients (mean age 55.5 +/- 11.5) with angiographically proven CAD and in 91 patients (mean age 56.3 +/- 10.6) with HT and angiographically excluded CAD, all without regional myocardial contractility abnormalities and valvular heart diseases. Control group consisted of 54 healthy subjects (mean age 55.4 +/- 11.4). During 2D echocardiography examination left ventricular end-diastolic (LVEDD) and end-systolic diameters (LVESD) and left atrial dimension (LA) were obtained. Using Doppler method transmitral inflow indices: E velocity (E), A velocity (A), E velocity integral (E-VTI), A velocity integral (A-VTI), total velocity integral (T-VTI), E deceleration time (DT), isovolumic relaxation time (IVRT) and aortic flow velocity integral (Ao-VTI) were measured. Only patients with E/A < or = 1 and--to exclude pseudonormalization of mitral inflow--with DT > or = 140 ms were qualified to the study. We proposed diastolic dysfunction ratio (DDR) calculated from formula: DDR = E/A x E-VTI/T-VTI. Using AFVI, LV outflow diameter, heart rate (HR) and body surface area cardiac index (CI) was calculated.

RESULTS

In studied group there were significantly higher values of LA, A, IVRT, DT and lower values of E, E/A, E-VTI and DDR compared to controls. There were no significant differences between these groups in HR, LVEDD, LVESD, T-VTI and CI. No significant differences in any of studied parameters were found between subgroups with CAD and HT. Among healthy subjects in subgroup with abnormal mitral inflow pattern (E/A < or = 1) there were significantly higher values of LA, IVRT, DT and lower values of DDR than in sugroup with normal one. Both subgroups did not differ in LVEDD, LVESD, CI. In the studied group there was positive correlation between DDR and CI (r = 0.69, p < 0.001), DDR and IVRT (r = 0.71, p < 0.001), DDR and DT (r = 0.61, p < 0.001), CI and E (r = 0.34, p < 0.01), CI and IVRT (r = 0.52, p < 0.001), CI and DT (r = 0.42, p < 0.001), CI and E/A (r = 0.54, p < 0.001), CI and E-VTI (r = 0.43, p < 0.001). In the control group significant correlation was found only between DDR and IVRT (r = 0.64, p < 0.02) and between DDR and DT (r = 0.52, p < 0.02) but not between DDR and CI. Using DDR DD was divided into 3 classes: class I with DDR > 0.47, class II with 0.47 > or = 0.30, and class III with DDR < 0.30. Applying of such intervals of values of DDR determined the groups which significantly differed between themselves in CI, IVRT and DT.

CONCLUSIONS

(1) In patients with CAD or HT with impaired relaxation of LV without symptoms of heart failure there is relation between parameters of systolic and diastolic function of LV: the more advanced diastolic dysfunction, the more impaired systolic function. (2) In healthy subjects there is no relation between parameters of systolic and diastolic function of LV. (3) DDR is a good indicator of quantitative estimation of diastolic dysfunction in the stage of impaired relaxation of LV.

[Right ventricular diastolic disfunction and its relation to left ventricular performance in patients with hypertension]

Abnormalities in left ventricular (LV) diastolic function may be the earliest indications of hypertensive heart disease. Because the two ventricles influence each other's performance this study was designed to investigate the impact of chronic LV pressure overload in essential hypertension (HT) on diastolic function of right ventricle (RV). RV and LV diastolic function was evaluated in 74 patients with mild-to-moderate essential HT using pulsed wave Doppler echocardiography. Fifty-five normotensive patients without heart disease acted as control subjects. In studied group, 17 patients (23%) had normal mitral (MV) and tricuspid (TV) flow parameters, 28 (38%) had impaired LV filling parameters [MV early (E) to late (A) peak flow velocity ratio (MV E/A) 0.81 +/- 0.12 vs control 1.19 +/- 0.18, p < 0.001] while 29 patients (39%) had abnormal both mitral [MV E/A) 0.72 +/- 0.15 vs control 1.19 +/- 0.18, p < 0.001] and tricuspid flow parameters (TV E/A) 0.8 +/- 0.19 vs control 1.23 +/- 0.1, p < 0.001). In group with impaired diastolic filling of both ventricles indices of mitral flow were significantly more abnormal compared to group with normal TV flow parameters (MV E/A 0.72 +/- 0.15 vs control 0.81 +/- 0.12, p < 0.05). RV filling parameters correlated with filling parameters. There was good correlation between TV A and MV E (r = -0.56, p < 0.01), the time velocity integral of early mitral inflow (MV E-VTI) (r = -0.64, p < 0.001) and positive correlation with MV A (r = 0.78, p < 0.0001). Also there was good correlation between LV mass and TV E (r = -0.56, p < 0.01) and the time velocity integral of early tricuspid inflow (r = -0.72, p < 0.001). Data indicate that RV diastolic function is abnormal in essential hypertension and these abnormalities are closely related to those of LV diastolic function and LV mass.

[The effect of amlodipine on structure and function of the heart and exercise tolerance in patients with hypertension]

The aim of the study was to assess whether the hypotensive activity of amlodipine is associated with regression of left ventricular hypertrophy and improvement of impaired LV or right ventricular (RV) diastolic function or increasing of tolerance of physical activity in hypertensive patients. Assessment of left ventricular structure, systolic and diastolic function as well as RV diastolic dimension and diastolic function were performed in 24 patients with mild-to-moderate hypertension before administration of amlodipine and 3, 6 and 9 months of the treatment. In order to assess the tolerance of physical activity, incremental treadmill exercise testing was performed at baseline and after 6 and 9 months of the therapy with amlodipine.

RESULTS

During 9 months of the therapy with amlodipine no significant change in indexes of LV mass or in LVM was observed. Similarly amlodipine did not influence the parameters of LV or RV diastolic function in studied patients. However, amlodipine treatment resulted in significant increase in total exercise time (p < 0.05), total workload (p < 0.01) measured in METs and decrease in diastolic blood pressure during exercise test.

CONCLUSION

The nine months of the therapy with amlodipine resulted in significant improvement in exercise tolerance. Total exercise duration and total workload measured in METs significantly increased. During this time of the therapy no significant changes in LV structure or LV and RV diastolic function were observed. One can make an assumption that amlodipine inhibits progression of structural and functional derangement in hypertensive patients.

[The effect of hypotensive drugs on left ventricular mass and diastolic function]

Chronic left ventricular hypertrophy (LVH) is associated with depressed contractile performance, abnormal compliance of the chamber, and ultimately, the development of a left ventricular failure. Thus the presence of LVH carries a particularly ominous prognosis in patients with essential hypertension. Finally, regression of LVH appears to be a worthwhile goal of an antihypertensive therapy along with blood pressure control. Of particular importance, is whether the functional derangements associated with hypertrophy will also be reversed. The present study was undertaken to determine whether antihypertensive therapy reduced ventricular mass, and whether these changes were accompanied by improved diastolic function. 47 patients with mild-to-moderate essential hypertension were divided into two groups. Group I--included 21 patients whose blood pressure responded to nifedipine monotherapy. Group II--included 26 patients whose normalization of blood pressure required combined therapy with nifedipine and metoprolol. 40 healthy volunteers comprised a control group. To assess the effects of antihypertensive therapy on the heart, left ventricular mas (LVM), systolic and diastolic function, by M-mode, 2-D and pulsed wave Doppler echocardiography had been evaluated. Measurements were performed before therapy and every 3rd month during first year, and every 40th month during the second year of observation. RESULTS. At baseline all hypertensive patients had significantly increased LVM compared to the controls. Indexes of systolic function in studied patients were normal, while indexes of LV diastolic filling were significantly abnormal compared to the controls. In the group treated with nifedipine, starting from the 9th month of observation, small but significant decrease in posterior wall thickness was noted but LVM did not change during the whole time of the observation. Similarly, there was no significant change in indexes of left ventricular diastolic filling. Contrary to patients treated with nifedipine, in group of patients treated with combination of nifedipine and metoprolol, significant reduction of LVM and improvement of LV diastolic filling was observed. Of particular interest was the fact, that improvement in diastolic, performance appeared earlier, and preceded regression of LVM. Most striking was the improvement in Ev/Av ratio which increased by 16% after 6 months and by 35% after 24 months of the therapy. CONCLUSION. 1. Combined therapy with nifedipine and metoprolol contrary to monotherapy with nifedipine alone, results in the regression of left ventricular mass and the improvement of left ventricular diastolic function. 2. Improvement of left ventricular diastolic function appears earlier, preceding the regression of left ventricular hypertrophy.

[Inotropic drugs in treatment of heart failure--advantages and adverse reactions]

Mechanism of action, hemodynamic effects, efficacy of both shortterm and chronic administration of available inotropic drugs are discussed. An emphasis is on the possible mechanism of detrimental sequelae of the chronic inotropic stimulation of the failing heart.

Synthesis and anticonvulsant properties of some arylsuccinate methylpyridylimides

In reaction of alpha-phenyl, alpha-p-chlorophenyl and alpha-m-chlorophenylsuccinic acid with various aminopyridines, N-pyridyl-substituted succinimides (compounds 1-14) were obtained. These compounds were investigated for their CNS activity. Compounds 1, 2, 5, 6 and 7 displayed anticonvulsant properties in the maximum electroshock test. Compounds 5 and 6 were also active in the pentetrazole test.

Beta-adrenergic receptors and catecholamines in acute myocardial infarction

Lymphocyte beta-adrenergic receptor density and plasma catecholamine concentrations were determined in 28 patients with acute myocardial infarction and compared with those in patients with angina pectoris and healthy persons. In patients with acute myocardial infarction beta-adrenergic receptor density was significantly lower (p less than 0.001) and plasma catecholamine levels significantly higher (p less than 0.001) as compared with corresponding values in patients with angina pectoris or healthy persons. beta-adrenergic receptor density in patients with angina pectoris were not significantly different from those in controls. A significant negative correlation between beta-adrenergic receptor density and plasma norepinephrine levels was observed in patients with acute myocardial infarction (r = -0.593; p less than 0.001; r = -0.615; p less than 0.001 respectively). It is suggested that decreased beta-adrenergic receptor density is a consequence of elevated plasma catecholamine levels in patients with acute myocardial infarction. It has been well documented that acute myocardial infarction is associated with enhanced activity of the sympathetic nervous system. Several studies have already been done showing that urinary excretion of catecholamines and plasma catecholamine concentrations are raised in the acute phase of myocardial infarction. Particularly high levels of plasma catecholamines appeared to be related to the severity of clinical course of myocardial infarction and were found in patients with cardiogenic shock, heart failure and arrhythmias. It is of interest that the peak elevation of plasma catecholamines correlated with the extent of myocardial damage as reflected by peak plasma CK activity and also correlated with acute and long-term mortality.(ABSTRACT TRUNCATED AT 250 WORDS)

Studies on the synergism of some hypotensive drugs with ethanol

Synergism of some hypotensive drugs with ethanol was studied for its influence on the central nervous system. A very strong central action of the drugs and ethanol administered simultaneously in subthreshold doses was observed. Intensity of synergism was calculated by comparing the results with the effective doses of each drug administered seperately.