Vitamin D receptor gene polymorphism influence on lumbar intervertebral disc degeneration.

Intervertebral disc (IVD) degeneration is a multifaceted pathology that is the main morphological cause of lower back pain. This study aimed to determine the link between the vitamin D receptor gene single nucleotide polymorphisms (SNPs) and degenerative processes of the lumbar spine. The complete lumbar spinal columns were collected from 100 Caucasian cadavers via ventral dissection. The specimens for the histological analysis were harvested from the L5/S1 IVDs and endplates. Then, the tissues were cut into slices, inserted into paraffin blocks, and stained. The histology was evaluated according to the Boos' protocol. Moreover, TaqI(rs731236), FokI(rs2228570), and ApaI(rs7975232) genotyping were performed. Lastly, the histological scores for different genotypes were analyzed. The overall Boos' score in the study group was 12.49. It consisted of a mean IVD score of 7.46 and endplate score of 5.39. The determination of the SNPs was successful in 99 specimens and had a distribution of all alleles in accordance with the Hardy-Weinberg equilibrium. No significant differences in overall histological degeneration scores were found between samples from donors with different genotypes. However, in subgroup analysis of specific regions on the IVD, the significant difference was found in posterior inner anulus fibrosus for ApaI. The results of this study suggest that one must be careful when interpreting the results of the clinical and/or radiological studies on vitamin D receptor gene polymorphisms and lumbar spine degeneration risk, because such a relationship, if present, is likely to be very subtle.

Penetration of the posterior interosseous nerve fibers into the dorsal capsule of the wrist - a new perspective on wrist innervation.

The dorsal capsule of the wrist and the DCSS may play a significant role in the conduction of nerve signals transmitted from proprioceptors present in SL to PIN, which is located above the dorsal capsule. Hence, this study aimed to determine if nerve fibers of PIN penetrate inside the dorsal capsule. The dorsal capsules of the wrist were dissected from both sides from 15 cadavers. Eventually, 30 dorsal capsules were dissected. It can be concluded that the PIN nerve fibers penetrate the dorsal capsule of the wrist, as the penetration was noticeable in every part evaluated. The present study proves that afferent fibers from the mechanoreceptors of the SLIL potentially pass through the DCSS and subsequently through the dorsal capsule of the wrist to the PIN. This knowledge can surely be of great use for hand surgeons that perform procedures on the dorsal wrist.

The effects of alloying with Cu and Mn and thermal treatments on the mechanical instability of Zn-0.05Mg alloy.

The detrimental effect of natural aging on mechanical properties of zinc alloys restricts their application as bioresorbable medical implants. In this study, aging of Zn-0.05Mg alloy and the effect of 0.5 Cu and 0.1 Mn (in weight percent) addition on the microstructure and tensile properties were studied. The alloys were cold rolled, aged and annealed; aiming to investigate the effects of precipitates and grain size on the mechanical properties and their stability. TEM analysis revealed that in ultrafine-grained binary Zn-0.05Mg alloy, the natural aging occurred due to the formation of nano-sized Mg2Zn11 precipitates. After 90 days of natural aging, the yield strength and ultimate tensile strength of Zn-0.05Mg alloy increased from 197±4 MPa and 227±5 MPa to 233±8 MPa and 305±7 MPa, respectively, while the elongation was drastically reduced from 34±3% to 3±1%. This natural aging was retarded by adding the third element at either 0.1Mn or 0.5Cu quantities, which interacted with Mg in Zn solid solution and impeded the formation of Mg2Zn11 precipitates. The addition of Cu and Mn elements increased alloy's strength, ductility, and its mechanical stability at a room temperature. The measured tensile strength and elongation were 274±5 MPa and 41±1% for Zn-0.1Mn-0.05Mg and 312±2 MPa and 44±2% for Zn-0.5Cu-0.05Mg, respectively. Annealing the alloys at elevated temperatures caused increase in both grain size and dissolution of secondary phases, and both affected alloy deformation mechanisms.

Quadricuspid pulmonary valve: macroscopic and microscopic morphometric examination.

A quadricuspid pulmonary valve obtained upon autopsy of a 26-year-old male was examined. The macroscopic evaluation revealed three normal (posterior, right anterior and left anterior) leaflets and one additional leaflet of the pulmonary valve. Except that, the heart showed neither other anatomical variabilities nor any signs of heart disease. The additional leaflet was located between the left anterior and right anterior leaflets and was significantly smaller in size. Under the microscope, all leaflets showed preservation of the typical, layered structure. The thickness and extracellular matrix composition of the particular layers differed between the leaflets. Right ventricular myocardium (myocardial sleeves) exceeded the level of the hinge line in all three normal leaflets, which was not observed in the additional leaflet. Autonomic nerves and ganglia were not seen in the perivalvular epicardial adipose tissue surrounding the additional leaflet. The sinus wall of all the leaflets revealed typical organization of collagen bundles as well as elastic fibers and showed no signs of disruption. The abnormality seen in the structure of the pulmonary valve is likely to be a result of disturbed embryonic development and may affect the clinical management of patients with such variation.

Combination of ERK2 inhibitor VX-11e and voreloxin synergistically enhances anti-proliferative and pro-apoptotic effects in leukemia cells.

ERK1/2 inhibitors are new promising anticancer drugs. The aim of this study was to investigate the effect of the combination of ERK2 inhibitor VX-11e and voreloxin on MOLM-14, K562, REH and MOLT-4 leukemia cell lines. We found that VX-11e alone and in combination with voreloxin significantly decreased ERK activation in all cell lines tested. To evaluate the interactions of the drugs, cells were treated for 24 h with VX-11e or voreloxin alone and in combination at fixed ratios based on IC50 values. The combinatorial effects of both drugs were synergistic over a wide range of concentrations in MOLM-14, REH and MOLT-4 cell lines. In K562 cells, three effects were found to be additive, one antagonistic and only one synergistic. The results showed that incubation with both VX-11e and voreloxin inhibited the growth of leukemia cells, affected cell cycle and induced apoptosis. Furthermore, the molecular mechanism of these effects might be attributed to an increased expression of p21 and a decreased expression of survivin and NF-κB in all cell lines tested except from K562 cells. In conclusion, combination of VX-11e and voreloxin can exert a synergistic anticancer effect in leukemia cells.

Precipitation induced room temperature superplasticity in Zn-Cu alloys.

In this study, the effect of grain size and precipitates on tensile properties of Zn-1.0Cu alloy were investigated. The alloy was cold rolled and annealed to manipulate the grain size and precipitation of CuZn4 particles at grain boundaries. Cold rolling resulted in an almost ultrafinegrained structure alongside precipitation of nano-sized CuZn4 particles. Strain induced precipitates triggered room temperature superplasticity through activation of Zn/CuZn4 boundary sliding, exhibiting maximum elongation of 470% at the strain rate of 1.0 × 10-4 s-1. Short-time annealing led to significantly reduced strain rate sensitivity due to the reduction of CuZn4 fraction, while the grain size remained nearly intact. This suggests that precipitates rather than grain size mainly influence the mechanical properties of Zn alloys.

Circadian Plasticity of Mammalian Inhibitory Interneurons.

Inhibitory interneurons participate in all neuronal circuits in the mammalian brain, including the circadian clock system, and are indispensable for their effective function. Although the clock neurons have different molecular and electrical properties, their main function is the generation of circadian oscillations. Here we review the circadian plasticity of GABAergic interneurons in several areas of the mammalian brain, suprachiasmatic nucleus, neocortex, hippocampus, olfactory bulb, cerebellum, striatum, and in the retina.

Effect of Associative Learning on Memory Spine Formation in Mouse Barrel Cortex.

Associative fear learning, in which stimulation of whiskers is paired with mild electric shock to the tail, modifies the barrel cortex, the functional representation of sensory receptors involved in the conditioning, by inducing formation of new inhibitory synapses on single-synapse spines of the cognate barrel hollows and thus producing double-synapse spines. In the barrel cortex of conditioned, pseudoconditioned, and untreated mice, we analyzed the number and morphological features of dendritic spines at various maturation and stability levels: sER-free spines, spines containing smooth endoplasmic reticulum (sER), and spines containing spine apparatus. Using stereological analysis of serial sections examined by transmission electron microscopy, we found that the density of double-synapse spines containing spine apparatus was significantly increased in the conditioned mice. Learning also induced enhancement of the postsynaptic density area of inhibitory synapses as well as increase in the number of polyribosomes in such spines. In single-synapse spines, the effects of conditioning were less pronounced and included increase in the number of polyribosomes in sER-free spines. The results suggest that fear learning differentially affects single- and double-synapse spines in the barrel cortex: it promotes maturation and stabilization of double-synapse spines, which might possibly contribute to permanent memory formation, and upregulates protein synthesis in single-synapse spines.

Circadian rhythmicity of synapses in mouse somatosensory cortex.

The circadian rhythmicity displayed by motor behavior of mice: activity at night and rest during the day; and the associated changes in the sensory input are reflected by cyclic synaptic plasticity in the whisker representations located in the somatosensory (barrel) cortex. It was not clear whether diurnal rhythmic changes in synapse density previously observed in the barrel cortex resulted from changes in the activity of the animals, from daily light/dark (LD) rhythm or are driven by an endogenous clock. These changes were investigated in the barrel cortex of C57BL/6 mouse strain kept under LD 12 : 12 h conditions and in constant darkness (DD). Stereological analysis of serial electron microscopic sections was used to assess numerical density of synapses. In mice kept under LD conditions, the total density of synapses and the density of excitatory synapses located on dendritic spines was higher during the light period (rest phase). In contrast, the density of inhibitory synapses located on dendritic spines increased during the dark period (activity phase). Under DD conditions, the upregulation of the inhibitory synapses during the activity phase was retained, but the cyclic changes in the density of excitatory synapses were not observed. The results show that the circadian plasticity concerns only synapses located on spines (and not those on dendritic shafts), and that excitatory and inhibitory synapses are differently regulated during the 24 h cycle: the excitatory synapses are influenced by light, whilst the inhibitory synapses are driven by the endogenous circadian clock.

In-vivo evaluation of molybdenum as bioabsorbable stent candidate.

Biodegradable stents have tremendous theoretical potential as an alternative to bare metal stents and drug-eluting stents for the treatment of obstructive coronary artery disease. Any bioresorbable or biodegradable scaffold material needs to possess optimal mechanical properties and uniform degradation behavior that avoids local and systemic toxicity. Recently, molybdenum (Mo) has been investigated as a potential novel biodegradable material for this purpose. With its proven moderate degradation rate and excellent mechanical properties, Mo may represent an ideal source material for clinical cardiac and vascular applications. The present study was performed to evaluate the mechanical performance of metallic Mo in vitro and the biodegradation properties in vivo. The results demonstrated favorable mechanical behavior and a uniform degradation profile as desired for a new generation ultra-thin degradable endovascular stent material. Moreover, Mo implants in mouse arteries avoided the typical cellular response that contributes to restenosis. There was minimal neointimal hyperplasia over 6 months, an absence of excessive smooth muscle cell (SMC) proliferation or inflammation near the implant, and avoidance of significant harm to regenerating endothelial cells (EC). Qualitative inspection of kidney sections showed a potentially pathological remodeling of kidney Bowman's capsule and glomeruli, indicative of impaired filtering function and development of kidney disease, although quantifications of these morphological changes were not statistically significant. Together, the results suggest that the products of Mo corrosion may exert beneficial or inert effects on the activities of inflammatory and arterial cells, while exerting potentially toxic effects in the kidneys that warrant further investigation.

Rapid, learning-induced inhibitory synaptogenesis in murine barrel field.

The structure of neurons changes during development and in response to injury or alteration in sensory experience. Changes occur in the number, shape, and dimensions of dendritic spines together with their synapses. However, precise data on these changes in response to learning are sparse. Here, we show using quantitative transmission electron microscopy that a simple form of learning involving mystacial vibrissae results in approximately 70% increase in the density of inhibitory synapses on spines of neurons located in layer IV barrels that represent the stimulated vibrissae. The spines contain one asymmetrical (excitatory) and one symmetrical (inhibitory) synapse (double-synapse spines), and their density increases threefold as a result of learning with no apparent change in the density of asymmetrical synapses. This effect seems to be specific for learning because pseudoconditioning (in which the conditioned and unconditioned stimuli are delivered at random) does not lead to the enhancement of symmetrical synapses but instead results in an upregulation of asymmetrical synapses on spines. Symmetrical synapses of cells located in barrels receiving the conditioned stimulus also show a greater concentration of GABA in their presynaptic terminals. These results indicate that the immediate effect of classical conditioning in the "conditioned" barrels is rapid, pronounced, and inhibitory.

Quality of life, health, eating habits and physical development of middle school adolescents in the Swietokrzyskie.

INTRODUCTION AND OBJECTIVE: Measurement of the health-related quality of life is currently one of the significant methods of self-evaluation of heath, enabling the detection of disorders in the biopsychosocial functioning of children and adolescents. The aim of the study was to establish significant relationships between the subjective sense of the health-related quality of life, eating habits and objective parameters of physical development among a group of adolescents. MATERIAL AND METHODS: The study applied a diagnostic survey methodology with the use of the KIDSCREEN-52 questionnaire, the Health Behaviour in School-aged Children (HBSC) questionnaire, anthropometric measures of choice, and a self-constructed questionnaire. The significance level was set at p<0.05. The collected data was gathered and analyzed using Statistica 10.0 PL. RESULTS: Three distinct groups of adolescents with a varying subjective sense of the quality of life were identified. The frequency of basic meal consumption among participants showed some abnormalities. This concerned breakfast in particular, which was consumed before going to school by over half of the participants (63.61%), with boys (70.07%) eating it significantly more frequently than girls (57.83%). Indices based on weight-to-height ratios, such as: BMI, Rohrer's Index and Slender Index were significantly greater in value among boys compared with girls. CONCLUSIONS: Adolescents from the Swietokrzyskie region, for the most part exhibited a high subjective sense of the quality of life. The physical development of the participants, as far as basic anthropometric characteristics are concerned, was mostly appropriate and consistent with a high subjective sense of the quality of life and exhibited eating habits.

A subjective sense of the quality of life in adolescents from the Swietokrzyskie Voivodship.

OBJECTIVES: The measurement of the health-related quality of life (HRQOL) is one of the most important methods for self-assessment of health, which makes it possible to identify irregularities in the physical, mental and social functioning. The aim of the research was to determine HRQOL using the Health Related Quality of Life Questionnaire for Children and Young People (the KIDSCREEN-52 questionnaire) - the instrument recommended by the World Health Organization - which makes it possible to distinguish groups of adolescents with a diversified subjective sense of the quality of life. MATERIAL AND METHODS: The study involved a group of 871 adolescents, 411 boys and 460 girls, aged 13-16 years, residing in the Swietokrzyskie Voivodship. The method of a diagnostic survey was used in the research. The KIDSCREEN-52 questionnaire, which is an instrument for examining the HRQOL of adolescents, was employed in the study. The k-means clustering method was applied, which made it possible to establish 3 groups of adolescents with a different subjective sense of the quality of life. RESULTS: Three groups of adolescents with a diversified subjective sense of the quality of life (high, average, low) were identified using the KIDSCREEN-52 questionnaire. The subjective quality of life in the majority of the respondents was high, in particular in those living in rural areas. The surveyed boys with a high subjective quality of life showed a significantly higher self-esteem, acceptance and peer support than the surveyed girls. CONCLUSIONS: The KIDSCREEN-52 questionnaire is an accurate and sensitive tool for assessing HRQOL. It allows identifying 3 groups of adolescents with a diversified subjective sense of the quality of life. It can form the basis for further diagnosis of the bio-psycho-social functioning of adolescents. Int J Occup Med Environ Health. 2021;34(3):415-25.

Recent advances and directions in the development of bioresorbable metallic cardiovascular stents: Insights from recent human and in vivo studies.

Over the past two decades, significant advancements have been made regarding the material formulation, iterative design, and clinical translation of metallic bioresorbable stents. Currently, magnesium-based (Mg) stent devices have remained at the forefront of bioresorbable stent material development and use. Despite substantial advances, the process of developing novel absorbable stents and their clinical translation is time-consuming, expensive, and challenging. These challenges, coupled with the continuous refinement of alternative bioresorbable metallic bulk materials such as iron (Fe) and zinc (Zn), have intensified the search for an ideal absorbable metallic stent material. Here, we discuss the most recent pre-clinical and clinical evidence for the efficacy of bioresorbable metallic stents and material candidates. From this perspective, strategies to improve the clinical performance of bioresorbable metallic stents are considered and critically discussed, spanning material alloy development, surface manipulations, material processing techniques, and preclinical/biological testing considerations. STATEMENT OF SIGNIFICANCE: Recent efforts in using Mg, Fe, and Zn based materials for bioresorbable stents include elemental profile changes as well as surface modifications to improve each of the three classes of materials.  Although a variety of alloys for absorbable metallic stents have been developed, the ideal absorbable stent material has not yet been discovered. This review focuses on the state of the art for bioresorbable metallic stent development. It covers the three bulk materials used for degradable stents (Mg, Fe, and Zn), and discusses their advances from a translational perspective. Strategies to improve the clinical performance of bioresorbable metallic stents are considered and critically discussed, spanning material alloy development, surface manipulations, material processing techniques, and preclinical/biological testing considerations.

Current applications and outcomes of venoarterial extracorporeal membrane oxygenation based on 6 years of experience: risk factors for in­hospital mortality.

INTRODUCTION: Data regarding venoarterial extracorporeal membrane oxygenation (VA ECMO) as a temporary circulatory support in cardiogenic shock (CS) for Central Europe are scarce. OBJECTIVES: The aim of the study was to disclose indications, in-hospital, and long-term (1-year) mortality along with risk factors. PATIENTS AND METHODS: The study is a retrospective investigation of patients who underwent VA ECMO for CS at a cardiosurgical tertiary center, from January 2013 to June 2018. A broad spectrum of pre- and postimplantation factors was tested using univariable analysis. RESULTS: A total of 198 patients met the inclusion criteria. The median (interquartile range) duration of support was 207 (91­339) hours, with no significant disparity among hospital survivors and nonsurvivors (P = 0.09). A total of 40.4% of patients died during ECMO support, while the joined in-hospital and 6-month mortality progressed to 65.2%, and 1-year mortality to 67.2%; 9% underwent a subsequent heart transplantation. Main adverse events were bleeding (76%), infection (56%), neurologic injury (15%), and limb ischemia (15%). Multiorgan failure was the most decisive risk factor of in-hospital mortality (odds ratio, 4.45; P <⁠0.001). Patients with postcardiotomy CS had a significantly lower out-of-hospital survival rate than the nonsurgical group (32.3% vs 45%; log-rank P = 0.037). CONCLUSION: The study showed survival benefit, despite frequent complications. The protocol focusing on proper candidate selection and timing can positively impact patient survival. Additional risk reduction can be achieved with a further increase of the team experience with ECMO.

CRY-dependent plasticity of tetrad presynaptic sites in the visual system of Drosophila at the morning peak of activity and sleep.

Tetrad synapses are formed between the retina photoreceptor terminals and postsynaptic cells in the first optic neuropil (lamina) of Drosophila. They are remodelled in the course of the day and show distinct functional changes during activity and sleep. These changes result from fast degradation of the presynaptic scaffolding protein Bruchpilot (BRP) by Cryptochrome (CRY) in the morning and depend on BRP-170, one of two BRP isoforms. This process also affects the number of synaptic vesicles, both clear and dense-core, delivered to the presynaptic elements. In cry01 mutants lacking CRY and in brpΔ170, the number of synaptic vesicles is lower in the morning peak of activity than during night-sleep while in wild-type flies the number of synaptic vesicles is similar at these two time points. CRY may also set phase of the circadian rhythm in plasticity of synapses. The process of synapse remodelling stimulates the formation of clear synaptic vesicles in the morning. They carry histamine, a neurotransmitter in tetrad synapses and seem to be formed from glial capitate projections inside the photoreceptor terminals. In turn dense-core vesicles probably carry synaptic proteins building the tetrad presynaptic element.

Targeting the MAPK/ERK and PI3K/AKT Signaling Pathways Affects NRF2, Trx and GSH Antioxidant Systems in Leukemia Cells.

The mitogen-activated protein kinase (MAPK)/extracellular signal kinase (ERK) and phosphatidylinositol 3-kinase (PI3K)/protein kinase B (AKT) signal transduction pathways have been implicated in the pathogenesis of leukemia. The aim of this study was to investigate the effect of the combination of ERK1/2 inhibitor AZD0364 and PI3K inhibitor ZSTK474 on acute lymphoblastic leukemia (ALL) REH, MOLT-4, acute myeloid leukemia (AML) MOLM-14, and chronic myeloid leukemia (CML) K562 cell lines. To evaluate the interactions of the drugs, cells were treated for 48 h with AZD0364 or ZSTK474 alone and in combination at fixed ratios. The combinatorial effects of both inhibitors were synergistic over a wide range of concentrations in REH, MOLT-4, and MOLM-14 cell lines. However, in K562 cells, the effects were found to be antagonistic. Furthermore, AZD0364 and ZSTK474 significantly decreased both ERK1/2 and AKT activation in REH, MOLT-4, and MOLM-14 cells. The results showed that incubation with both AZD0364 and ZSTK474 inhibited cell viability, increased reactive oxygen species (ROS) production, and induced apoptosis in leukemia cells. We observed that combined treatment with AZD0364 and ZSTK474 affected nuclear factor-κB (NF-κB) and antioxidant protein levels: NF-E2-related factor 2 (NRF2), heme oxygenase-1 (HO-1), thioredoxin (Trx), thioredoxin reductase (TrxR), and the reduced glutathione/oxidized glutathione (GSH/GSSG) ratio. These effects were accompanied with decreased antiapoptotic survivin protein level. However, distinct cell line dependent effects were observed. In conclusion, the combination of AZD0364 and ZSTK474 can exert a synergistic anticancer effect in ALL and AML cells, which is associated with the induction of oxidative stress and the involvement of cellular antioxidant defense mechanisms.

Combination of ERK2 and STAT3 Inhibitors Promotes Anticancer Effects on Acute Lymphoblastic Leukemia Cells.

BACKGROUND/AIM: Deregulated activation of signaling through the RAS/RAF/mitogen-activated protein kinase/extracellular signal-regulated kinase (RAS/RAF/MEK/ERK) and signal transducer and activator of transcription (STAT) pathways is involved in numerous hematological malignancies, making it an attractive therapeutic target. This study aimed to assess the effect of the combination of ERK2 inhibitor VX-11e and STAT3 inhibitor STA-21 on acute lymphoblastic leukemia cell lines REH and MOLT-4. MATERIALS AND METHODS: REH and MOLT-4 cell lines were cultured with each drug alone and in combination. Cell viability, ERK activity, cell cycle distribution, apoptosis and oxidative stress induction were assessed by flow cytometry. Protein levels of STAT3, phospho-STAT3, protein tyrosine phosphatase 4A3 (PTP4A3), survivin, p53 and p21 were determined by western blotting. RESULTS: VX-11e in combination with STA-21 significantly inhibited cell viability, induced G0/G1 cell-cycle arrest, enhanced production of reactive oxygen species, and induced apoptosis. These effects were associated with an increased level of p21 protein in REH cells and with reduced levels of phopho-STAT3, survivin and PTP4A3 proteins in MOLT-4 cells. CONCLUSION: Our findings provide a rationale for combined inhibition of RAS/RAF/MEK/ERK and STAT3 pathways in order to enhance anticancer effects against acute lymphoblastic leukemia cells.

Circadian Changes of Dendritic Spine Geometry in Mouse Barrel Cortex.

The circadian rhythmicity changes the density and shape of dendritic spines in mouse somatosensory barrel cortex, influencing their stability and maturation. In this study, we analyzed the main geometric parameters of dendritic spines reflecting the strength of synapses located on these spines under light/dark (12:12) and constant darkness conditions, in order to distinguish between endogenously regulated and light-driven parameters. Using morphological analysis of serial electron micrographs, as well as three-dimensional reconstructions, we found that the light induces elongation of single-synapse spine necks and increases in the diameter of double-synapse spine necks, increasing and decreasing the isolation of synapses from the parent dendrite, respectively. During the subjective night of constant darkness, we observed an enlargement of postsynaptic density area in inhibitory synapses and an increase in the number of polyribosomes inside double-synapse spines. The results show that both endogenous effect (circadian clock/locomotor activity) and light affect the morphological parameters of single- and double-synapse spines in the somatosensory cortex: light reduces the efficiency of excitatory synapses on single-synapse spines, increases the effect of synaptic transmission in double-synapse spines, and additionally masks the endogenous clock-driven enlargement of inhibitory synapses located on double-synapse spines. This indicates a special role of double-synapse spines and their inhibitory synapses in the regulation of synaptic transmission during both circadian and diurnal cycles in the mouse somatosensory cortex.