The effects of chronic manganese administration on blood pressure in rats

Recently it was observed that several trace elements, including manganese (Mn), can affect the cardiovascular system and have been implicated in certain cardiovascular disease mechanisms. However, to date the effects of Mn on the vascular system, such as in the control of blood flow and blood pressure, are not completely understood. The main objective of the present study was to determine the effects of a 45-day exposure to two different doses of Mn, on blood pressure values of male Wistar rats. Our results show a significant time effect (p<0.001, ANOVA, repeated measures) on blood pressure during the 45 days of chronic Mn treatment with two doses of Mn (3 mg/kg/day; 10 mg/kg/day). Additionally, we observed significant differences in blood pressure, especially on days 2 (p<0.001), 9 (p<0.05), 24 (p<0.05), 28 (p<0.01) and 43 (p<0.05). Further studies are necessary in order to establish the mechanism and relevance of Mn

The effects of chronic manganese administration on blood pressure in rats

Several trace elements, including manganese (Mn), affect the cardiovascular system and are implicated in some cardiovascular disease mechanisms. The effects of Mn on the vascular system, such as in the control of blood flow and blood pressure, are not completely understood. Thus, the main objective of the present study was to determine the effects of a 45-day exposure to two different doses of Mn on blood pressure values of male Wistar rats. Our results showed a significant time effect (p<0.001, ANOVA, repeated measures) on the values of blood pressure measurements during 45 days of Mn treatment of rats with two doses (3 mg/kg/day and 10 mg/kg/day). Additionally, we observed significant differences in the values of blood pressure measurements, especially on days 2 (p<0.001), 9 (p<0.05), 24 (p<0.05), 28 (p<0.01) and 43 (p<0.05). Further studies are necessary in order to establish the mechanism and relevance of Mn in this area of research

THE OXIDATIVE STRESS HYPOTHESIS IN ALZHEIMER’S DISEASE

Oxidative stress may be involved in many somatic and psychiatric pathological states including dementia. The hypothesis of oxidative stress involvement in dementia is supported by much scientific data through biochemical, genetic and molecular studies. Thus, there are many reports of an increased level of the markers for oxidative damage, alterations in the specific activity of the antioxidant system, mutations in specific genes, mitochondrial disturbances and also several connections between oxidative stress and amyloid plaques. Despite these evidence and clinical approaches in using antioxidant therapy in dementia treatment, studies have failed to prove a clear benefit for antioxidant treatment in dementia. Hence, there is a need for further research regarding antioxidant therapy in very early stages of dementia

Vascular calcification in chronic kidney disease

A B S T R A C T VC (vascular calcification) is highly prevalent in patients with CKD (chronic kidney disease), but its mechanism is multifactorial and incompletely understood. In addition to increased traditional risk factors, CKD patients also have a number of non-traditional cardiovascular risk factors, which may play a prominent role in the pathogenesis of arterial calcification, such as duration of dialysis and disorders of mineral metabolism. The transformation of vascular smooth muscle cells into chondrocytes or osteoblast-like cells seems to be a key element in VC pathogenesis, in the context of passive calcium and phosphate deposition due to abnormal bone metabolism and impaired renal excretion. The process may be favoured by the low levels of circulating and locally produced VC inhibitors. VC determines increased arterial stiffness, left ventricular hypertrophy, a decrease in coronary artery perfusion, myocardial ischaemia and increased cardiovascular morbidity and mortality. Although current therapeutic strategies focus on the correction of phosphate, calcium, parathyroid hormone or vitamin D, a better understanding of the mechanisms of abnormal tissue calcification may lead to development of new therapeutic agents, which could reduce VC and improve cardiovascular outcome in CKD patients. The present review summarizes the following aspects: (i) the pathophysiological mechanism responsible for VC and its promoters and inhibitors, (ii) the methods for detection of VC in patients with CKD, including evaluation of arterial stiffness, and (iii) the management of VC in CKD patients

Relevance of the body mass index in the cognitive status of diabetic patients with different alcohol-drinking patterns

Nowadays the general relevance of alcohol consumption in diabetes is extremely controversial. There are recent reports that alcohol consumption could result in a decreased incidence of diabetes, as well as other studies demonstrating a positive association between alcohol consumption and type 2 diabetes; there are also reports arguing for an inverse association between the two or for no correlation at all. The different results obtained in these studies could be explained by the existence of several confounders that could influence the outcome of the aforementioned studies. In this paper, we studied the possible relevance of BMI as a confounder in the relationship between alcohol consumption in diabetes and cognitive function, by analyzing the correlations between BMI values in diabetic patients with different alcohol drinking patterns and the subdomains from some main psychometric tests, such as MMSE (Mini-Mental State Examination) and MOCA (Montreal Cognitive Assessment). Our results provide evidence for BMI as a possible confounder of the relationship between alcohol consumption in diabetes and cognitive function. We found a significant increase (p<0.0001) in BMI values in patients with diabetes compared to our control group. Most importantly, significant correlations between BMI parameters in alcohol-consuming diabetic patients and most of the subdomains for psychometric testing

Connections between Orthopedic Conditions and Oxidative Stress: Current Perspective and the Possible Relevance of Other Factors, Such as Metabolic Implications, Antibiotic Resistance, and COVID-19

The general opinion in the literature is that these topics remain clearly understudied and underrated, with many unknown aspects and with controversial results in the respective areas of research. Based on the previous experience of our groups regarding such matters investigated separately, here we attempt a short overview upon their links. Thus, we summarize here the current state of knowledge regarding the connections between oxidative stress and: (a) orthopedic conditions; (b) COVID-19. We also present the reciprocal interferences among them. Oxidative stress is, of course, an interesting and continuously growing area, but what exactly is the impact of COVID-19 in orthopedic patients? In the current paper we also approached some theories on how oxidative stress, metabolism involvement, and even antibiotic resistance might be influenced by either orthopedic conditions or COVID-19. These manifestations could be relevant and of great interest in the context of this current global health threat; therefore, we summarize the current knowledge and/or the lack of sufficient evidence to support the interactions between these conditions

Biological aspects of cannabis consumption in schizophrenia

Schizophrenia and psychotic disorders are major health issues with particular implications for both the individual and the medical system. Epidemiological data show a more frequent consumption of drugs in schizophrenic patients when compared to the general population. Studies have shown that the abuse of substances is the most common comorbidity associated with schizophrenia. Among illicit substances, cannabis is the most commonly encountered among patients with schizophrenia. Similar clinical features of schizophrenia and cannabis consumption could be explained by some common neurobiological implications. N-methyl-D-aspartate (NMDA) receptor stimulation is associated with psychotic-type phenomena and schizophrenia and NMDA receptors are involved in the clinical effects of cannabis consumption. Thus, the CB1 receptors that are spread mainly at the level of the NMDA secretory neurons are activated by tetrahydrocannabinol, the psychoactive component of cannabis. Moreover, cannabis abuse in association with other factors may contribute in triggering schizophrenia. Therefore, patients diagnosed with schizophrenia that abuse substances such as cannabis could represent a special category of patients that require a complex therapeutic approach, especially considering the multiple problems implicated, such as reduced compliance with treatment, unfavorable evolution and prognosis with multiple relapses and frequent hospitalizations

The Impact of Angiotensin-Converting Enzyme-2/Angiotensin 1-7 Axis in Establishing Severe COVID-19 Consequences

The COVID-19 pandemic has put a tremendous stress on the medical community over the last two years. Managing the infection proved a lot more difficult after several research communities started to recognize the long-term effects of this disease. The cellular receptor for the virus was identified as angiotensin-converting enzyme-2 (ACE2), a molecule responsible for a wide array of processes, broadly variable amongst different organs. Angiotensin (Ang) 1-7 is the product of Ang II, a decaying reaction catalysed by ACE2. The effects observed after altering the level of ACE2 are essentially related to the variation of Ang 1-7. The renin-angiotensin-aldosterone system (RAAS) is comprised of two main branches, with ACE2 representing a crucial component of the protective part of the complex. The ACE2/Ang (1-7) axis is well represented in the testis, heart, brain, kidney, and intestine. Infection with the novel SARS-CoV-2 virus determines downregulation of ACE2 and interrupts the equilibrium between ACE and ACE2 in these organs. In this review, we highlight the link between the local effects of RAAS and the consequences of COVID-19 infection as they arise from observational studies