Pathophysiology of spontaneous coronary artery dissection: hematoma, not thrombus

Spontaneous coronary artery dissection (SCAD) accounts for 1.7%-4% of all acute coronary syndrome presentations, particularly among young women with an emerging awareness of its importance. The demarcation of acute SCAD from coronary atherothrombosis and the proper therapeutic approach still represents a major clinical challenge. Certain arteriopathies and triggers are related to SCAD, with high variability in their prevalence, and often, the cause remains unknown. The objective of this review is to provide contemporary knowledge of the pathophysiology of SCAD and possible therapeutic solutions.

Morphometric and volumetric analysis of lacrimal glands in patients with thyroid eye disease

Assessment of morphometric and volumetric changes in lacrimal glands in thyroid eye disease, its clinical manifestations in relation of disease progression. Retrospective volumetric analysis included both genders and was performed on total of 183 patients - 91 patients with diagnosed Grave's disease and thyroid eye disease and 92 patients without Grave's disease and thyroid eye disease who underwent multidetector computed tomography (MDCT) examination in routine daily work according to other medical indications. In the group of females, there was statistical significance between patients with thyroid eye disease and controls who were smoking and had body weight gain. We found statistical significance in volumetric enlargements for both orbits in both genders for the patients group when compared to controls. There was also statistical significance in morphometric characteristics for the lacrimal gland diameters measured. Determination planimetric morphometric parameters of importance were coronary height of lacrimal gland of the right eye, coronary height of lacrimal gland of the left eye and coronary width of lacrimal gland of the left eye for the group of males. In a group of females the established determination parameters of importance were the coronary height of lacrimal gland of the left eye, the axial width of lacrimal gland of the left eye, volume of lacrimal gland of the right eye and the volume of lacrimal gland of the left eye. When we compared the displaced lacrimal gland coming forward (proptosis) in time progressing disease between group of patients and controls, we also found statistical significant connection. Evaluation of lacrimal gland volumetric and morphometric data may increase validity of defining this anatomical substrate and its morphology disruption as liable tool for thyroid eye disease progression follow up and treatment planning and outcome.

Quantitative and Qualitative Characteristics of Atherosclerotic Plaques on Carotid Arteries in Patients with Antiphospholipid Syndrome: The Role of MDCT Angiography

INTRODUCTION

Antiphospholipid syndrome (APS) is an autoimmune disease characterised by arterious and venous thrombosis, miscarriage, and the presence of antiphospholipid antibodies (aPL) in the blood. As we know, APS is also characterised by accelerated atherosclerotic degeneration with an increased risk of thrombosis in all blood vessels, including the carotid arteries. Carotid artery stenosis can manifest in many different ways. The aim of this study is to present the results of our multidetector computerised tomography angiography (MDCTA) analysis of the carotid arteries in patients with primary and secondary APS compared with a control group.

MATERIALS AND METHODS

This study examined 50 patients with primary antiphospholipid syndrome (PAPS) and 50 patients with secondary antiphospholipid syndrome (SAPS). The results were compared with a control group also comprising 50 patients. The groups were analysed with respect to age, sex and the presence of well-established risk factors for vascular disease. The study was conducted using MDCTA, where we analysed the quantitative and qualitative (morphologic) characteristics of carotid artery lesions.

RESULTS

Patients from the control group had significantly elevated levels of cholesterol and triglycerides in comparison with patients with PAPS and SAPS (p < 0.001 and p < 0.05). The results show that carotid artery lesions were significantly more common in patients with APS (PAPS, n = 40, CI95: 0.50-0.75, p = 0.0322 and SAFS, n = 54, CI95: 0.59-0.80, p = 0.0004) than within the control group (n = 23). There was a statistically significant difference between patients with APS and the control group with respect to lesions in the distal segments (n = 27, CI95: 0.67-0.95, p = 0.0001), bulbi and proximal segments (n = 21, CI95: 0.84-1.00, p = 0.000005). The number of patients with one lesion (L) (n = 27) was significantly greater than the number of those with three (n = 10, CI95: 0.56-0.86, p = 0.0051) or four (n = 3, CI95: 0.73-0.98, p = 0.00001) lesions. There were also more patients with two lesions (n = 24) than those with four (n = 3) (CI95: 0.71-0.97, p = 0.00005). Carotid artery stenosis was shown as a percentage of the carotid artery lumen diameter (%DS). Stenosis of up to 30%, was more common in patients in the PAPS group (n = 12) than in the control group (n = 3) (CI95: 0.52-0.96, p = 0.0201), while the SAPS group (n = 17) had an even larger disparity (CI95: 0.62-0.97, p = 0.0017). We observed a highly significant difference in the frequency of stenoses between 30% and 50% DS between the PAPS group (n = 24) and the control group (n = 7) (CI95: 0.59-0.90, p = 0.0023), as well as the SAPS group (n = 30) (CI95: 0.65-0.92, p = 0.0002). A qualitative analysis of plaque morphology revealed that patients with PAPS had significantly more soft tissue lesions (n = 23) compared with calcified lesions (n = 2) (CI95: 0.74-0.99, p = 0.00003), as well as more mixed plaques (n = 9) and calcified plaques (n = 2) (CI95: 0.48-0.98, p = 0.0348). Patients within the SAPS group had significantly more soft tissue (n = 35) than calcified lesions (n = 3) (CI95: 0.79-0.98, p = 0.00000021), as well as more mixed lesions (n = 21) compared with calcified (n = 3) (CI95: 0.68-0.97, p = 0.0002).

CONCLUSIONS

Our study shows that subclinical manifestations of carotid artery lesions were more common in patients with APS. We came to the conclusion that MDCTA is an accurate diagnostic method because it is a safe method that provides us with a great quantity of accurate information about the characteristics of atheromatous plaques, which aids us in the further planning of treatment for patients with APS.

The role of cadmium in the pathogenesis of myeloid leukemia in individuals with anemia, deficiencies in vitamin D, zinc, and low calcium dietary intake

Iron deficiency, vitamin D deficiency and low calcium diet are frequent health problems with severe long- term consequences. Upon absorption from the duodenum, cadmium binds to transferrin, and cells with the highest density of transferrin receptor 1 (TfR1) take up the majority of the circulating cadmium. Nowadays, it is clear that individuals with iron deficiency anemia have increased blood levels of cadmium because of higher absorption rate, mediated by divalent metal transporter 1 (DMT1). However, the transient receptor potential vanilloid receptor 6 (TRPV6), known as a calcium carrier, is able to bind and transport cadmium as well. In the case of low calcium diet or vitamin D deficiency, TRPV6 may be overexpressed in the intestine and kidney tubules and absorbs (re-uptake in the case of renal tubules) cadmium in larger quantities, resulting in an increased cadmium blood levels. We speculate that the final event in the case of low calcium dietary diet and/or vitamin D deficiency is similar to what is observed in the case of iron deficiency, that cells with the highest levels of TfR1 (for example, megakaryocyte/erythrocyte progenitors and pro-erythroblasts) take up most of the circulating cadmium, which is powerful malignancy inductor, leading to appearance of acute myeloid leukemia (AML).

The long-term effects of maternal deprivation on the number and size of inhibitory interneurons in the rat amygdala and nucleus accumbens

Introduction

There is an increasing evidence supporting the hypothesis that traumatic experiences during early developmental periods might be associated with psychopathology later in life. Maternal deprivation (MD) in rodents has been proposed as an animal model for certain aspects of neuropsychiatric disorders.

Methods

To determine whether early-life stress leads to changes in GABAergic, inhibitory interneurons in the limbic system structures, specifically the amygdala and nucleus accumbens, 9-day-old Wistar rats were exposed to a 24 h MD. On postnatal day 60 (P60), the rats were sacrificed for morphometric analysis and their brains were compared to the control group.

Results

Results show that MD affect GABAergic interneurons, leading to the decrease in density and size of the calcium-binding proteins parvalbumin-, calbindin-, and calretinin-expressing interneurons in the amygdala and nucleus accumbens.

Discussion

This study indicates that early stress in life leads to changes in the number and morphology of the GABAergic, inhibitory interneurons in the amygdala and nucleus accumbens, most probably due to the loss of neurons during postnatal development and it further contributes to understanding the effects of maternal deprivation on brain development.

Effects of Maternal Deprivation on the Prefrontal Cortex of Male Rats: Cellular, Neurochemical, and Behavioral Outcomes

Stressful events experienced during early life are associated with increased vulnerability of developing psychopathology in adulthood. In the present study, we exposed 9-day-old Wistar rats to 24 h maternal deprivation (MD) with the aim to investigate the impact of early life stress (ELS) on morphological, biochemical, and functional aspects of the prefrontal cortex (PFC), a brain region particularly sensitive to stress. We found that in the superficial medial orbital cortex (MO), young adult male rats had reduced density of GAD67 and CCK immunopositive cells, while the rostral part of the ventral lateral orbital cortex (roVLO) showed a decrease in the density of GAD67 immunopositive cells in both superficial and deep layers. In addition, the superficial rostral part of area 1 of the cingulate cortex (roCg1) and deep prelimbic cortex (PrL) was also affected by MD indicated by the reduction in PV immunopositive cellular density. Furthermore, MD induced upregulation of brain-derived neurotrophic factor (BDNF), while it did not affect the overall expression of Iba1 in neonatal or young adult PFC as measured by Western blot, however, microglial activation in young adult MD rats was detected immunohistochemically in deep layers of MO and infralimbic cortex (IL). Interestingly, when young adult male rats were subjected to a behavioral flexibility test in a T-maze, MD rats showed a subtle impairment in T-maze reversal learning indicating a mildly affected PFC function. Taken together, our findings demonstrated that MD reduced the density of interneurons and induced microglial activation, in particular, PFC areas at young adulthood, and could alter synaptic plasticity accompanied by PFC dysfunction.

Glucocorticoid levels after exposure to predator odor and chronic psychosocial stress with dexamethasone application in rats

This study was conducted to explore the effects of specific psychosocial paradigm on predator animal posttraumatic stress model and to test the hypothesis that psychosocially stressed rats would exibit abnormal levels of cortisol and a larger suppression of cortisol levels after the application of dexamethasone. Animals were divided in two groups: experimental and control groups. The experimental group was exposed to two types of stressors: acute immobilization stress, and combined predator stress and daily social stress with application of dexamethasone. Blood sampling was performed at three different times. We found statistically significant results after analyzing the differences between cortisol levels in different times of blood sampling in the group of animals exposed to stress with dexamethasone application. Statistical significance was found when we compared the experimental group with the control group in terms of elevated cortisol levels during blood sampling after stress paradigm exposition. Many significant disruptions in the functioning of the hypothalamic-pituitary-adrenal axis were observed, such as decrease in basal cortisol levels and enhanced dexamethasone-induced inhibition of cortisol levels. These findings are important because their impact can translate to human individuals with posttraumatic stress disorder, which is the most important role of every animal model in research.

Effects of Chronic Psychosocial Stress on Reduction of Basal Glucocorticoid Levels and Suppression of Glucocorticoid Levels Following Dexamethasone Administration in Animal Model of PTSD

Aim: To further examine the neurobiological mechanisms and their outcomes responsible for the PTSD sequelae induced by laboratory animal model and to explore the effects of chronic psychosocial paradigm. We tested the hypothesis that our animal model of PTSD would display abnormalities in glucocorticoid levels that are manifest in people with PTSD and that psychosocially stressed rats exhibit a significantly greater suppression of corticosterone levels than control rats following the administration of dexamethasone.Methods: Animals were divided into two groups. The experimental group was scheduled to exposure to two types of stressors: double exposure to acute immobilization stress, and combined predator-threat stress and daily social stress. There was also administration of dexamethasone in combination with stress exposure.Results: There was a statistical difference between masses of thymus in the stress group and stress group with dexamethasone appliance (p=0.024). We found statistical significance between baseline cortisol and stress induced levels of cortisol and between stress induced group and return to baseline group.Conclusion: Significant changes in HPA activity, reductions in basal glucocorticoid levels and enhanced dexamethasone induced inhibition of glucocorticoid levels have been manifested. All of this is manifested in PTSD patients also as many other stress induces changes.

Ryanodine receptors, voltage-gated calcium channels and their relationship with protein kinase A in the myocardium

We present a review about the relationship between ryanodine receptors and voltage-gated calcium channels in myocardium, and also how both of them are related to protein kinase A. Ryanodine receptors, which have three subtypes (RyR1-3), are located on the membrane of sarcoplasmic reticulum. Different subtypes of voltage-gated calcium channels interact with ryanodine receptors in skeletal and cardiac muscle tissue. The mechanism of excitation-contraction coupling is therefore different in the skeletal and cardiac muscle. However, in both tissues ryanodine receptors and voltage-gated calcium channels seem to be physically connected. FK-506 binding proteins (FKBPs) are bound to ryanodine receptors, thus allowing their concerted activity, called coupled gating. The activity of both ryanodine receptors and voltage-gated calcium channels is positively regulated by protein kinase A. These effects are, therefore, components of the mechanism of sympathetic stimulation of myocytes. The specificity of this enzyme's targeting is achieved by using different A kinase adapting proteins. Different diseases are related to inborn or acquired changes in ryanodine receptor activity in cardiac myocytes. Mutations in the cardiac ryanodine receptor gene can cause catecholamine-provoked ventricular tachycardia. Changes in phosphorylation state of ryanodine receptors can provide a credible explanation for the development of heart failure. The restoration of their normal level of phosphorylation could explain the positive effect of beta-blockers in the treatment of this disease. In conclusion, molecular interactions of ryanodine receptors and voltage-gated calcium channels with PKA have a significant physiological role. However, their defects and alterations can result in serious disturbances.