A Study of The Relationship Between Mandibular Second Molar Impaction and Class II Malocclusions

Introduction: Detection of impacted teeth by the orthodontist is imperative for diagnosis and treatment planning. A tooth is impacted when it has arrested eruption due to the presence of a clinically or radiographically visible physical barrier in the path of eruption. The most commonly impacted teeth are third molars, followed by maxillary canines and mandibular second premolars. When referring to mandibular second molar (MM2) impaction, prevalence ranges from as low as 0.06-0.65%1-5, to as high as 1.36% and 1.8%. Numerous studies have identified etiologic risk factors for MM2 impaction, such as mesial crown angulation, dental crowding, morphological tooth anomalies, and a smaller distance between the mandibular first molar and the mandibular ramus.4-8 Studies also suggest a positive correlation between vertically directed condylar growth and impaction rates of mandibular second and third molars. However, to this day, few studies have correctly used lateral cephalograms to evaluate the skeletal morphology of the mandible and its relationship mandibular second molar impaction.5,9 Thus, the goal of this research study was to evaluate if there is a relationship between MM2 impaction and Class II malocclusions. Methods: In this retrospective study, 75 subjects with impaction of MM2 were compared to a control group of 200 subjects with normal eruption of MM2. Based on evaluation of panoramic x-rays, MM2 was classified as impacted if its complete eruption to occlusal plane height was prevented by an abnormal contact with another tooth in the same arch, and when it remained unerupted beyond ¾ root formation. The corresponding lateral cephalograms were then traced and analyzed using Dolphin Imaging Software available in the Nova Southeastern University Post-Graduate Orthodontic Clinic. Frequencies and percentages were calculated for all categorical variables, and means and standard deviations were calculated for continuous measures. Wilcoxon-Mann-Whitney-U-tests was used for statistical comparisons between groups, and a logistic regression model was used to examine the relationship between various independent variables and the presence of impaction. Results: No association was found between gender, age, and mandibular second molar (MM2) impaction. The sagittal analysis showed that MM2 impaction was more commonly seen in skeletal Class II patients (p\u3c0.05). However, mandibular corpus length (Xi-Pm) and eruption space (MM1-Xi) showed no statistically significant difference between groups. Vertical analysis in the MM2 impaction group showed significantly larger values for SN-MP, FH-MP (FMA), and SGn-FH (p\u3c0.05). Lastly, the logistic regression model showed that hyperdivergent patients were nearly four times more likely to have MM2 impaction than hypodivergent patients (OR=3.99, p=0.009). Conclusions: Although Class II malocclusions were more likely to present with MM2 impaction than Class I malocclusions, this study could not confirm that a short mandible or one that has reduce retromolar eruption space is the cause of MM2 impaction. Instead, our findings showed the importance of evaluating the vertical morphology of the mandible and its association with mandibular second molar impaction. This seems to be a useful finding for treatment planning, especially in cases that are being planned for maximum mandibular anchorage or distalizing mechanics

THE EFFECT OF SUMMER STORM EVENTS AS A DISTURBANCE ON THE MOVEMENT BEHAVIORS OF BLACK SEA BASS IN THE SOUTHERN MID-ATLANTIC BIGHT

Storm events are a key disturbance in the Middle Atlantic Bight (MAB), driving thermal, hydrodynamic, and acoustic perturbations on demersal fish communities. Black sea bass are a model MAB species as their sedentary behavior exposes them to storm disturbances. I coupled biotelemetry with an oceanographic model, monitoring black sea bass movement behaviors during the summer-fall of 2016-2018. Storm-driven changes in bottom temperature (associated with rapid destratification) had the greatest effects on fish movement and evacuation rates, while the cumulative effects of consecutive storms had little to no observed effect. Storms also generate substantial noise, but the hearing frequencies of black sea bass are currently unknown. I conducted a quantitative literature analysis on fish hearing based on swim bladder elaboration, successfully classifying detected sound frequency ranges among fishes, including black sea bass. Climate change will likely alter the intensity of MAB storms, prioritizing research on their impacts to fish communities

Haptoglobin 2-1 phenotype predicts rapid growth of abdominal aortic aneurysms

BackgroundHaptoglobin (Hp) polymorphism is associated with the prevalence and clinical evolution of many inflammatory diseases and atherosclerosis. Circulating neutrophils and neutrophil-associated proteases are an important initial component of experimental abdominal aortic aneurysm (AAA) formation. Elastase and C-reactive protein (CRP) levels are elevated in patients with AAAs. This study assessed the relationship between AAA expansion and Hp phenotypes, neutrophil count, elastase, and CRP levels.MethodsEighty-three consecutive AAA patients underwent annual ultrasound scans. Three major Hp phenotypes (1-1, 2-1, and 2-2) were determined, and the neutrophil count, serum elastase, and high-sensitivity (hs) CRP levels were measured at the initial examination. After initial screening, patients were rescanned at 6- to 12-month intervals up to a period of 2 to 7 years. The mean yearly growth of the AAA largest transverse diameter was estimated for each group of Hp patients. The results are presented as median (interquartile range).ResultsHp 2-1 patients had a significantly higher growth rate (3.69 [2.40] mm/y) of AAA compared with patients with Hp 2-2 (1.24 [0.79], P < .00001) and Hp 1-1 (1.45 [0.68], P = .00004). This association remained significant in the multivariate analysis. Elevated elastase serum activity was also evident in AAA patients with Hp 2-1 (0.119 [0.084] arbitrary units) in contrast to Hp 2-2 (0.064 [0.041], P < .00001) and Hp 1-1 (0.071 [0.040], P = .0006) patients. CRP serum levels (mg/L) were significantly higher in patients with Hp 2-1 (7.2 [7.1]) than in Hp 2-2 (3.4 [3.1], P = .0058) and Hp 1-1 (2.8 [4.1], P = .044). The neutrophil count was not significantly different among Hp groups.ConclusionsThe Hp 2-1 phenotype showed a strong association with increased rates of the expansion of AAAs and may be a useful independent predictor of growth rate. Further large follow-up studies will be needed to investigate the pathomechanisms of association and the role of elastase and inflammation in the progression of AAA.Clinical RelevanceElective surgical or endovascular repair is recommended for large aneurysms, whereas small aneurysms are managed by watchful waiting. The diameter and rate of growth of the AAA are the most important determinants of the risk of rupture and in deciding when elective repair is justified. In the present study, the Hp 2-1 phenotype predicted rapid aneurysm expansion. This may have implications for the frequency of follow-up and timing of repair of AAA in patients with the Hp 2-1 phenotype

Coagulation and fibrinolysis in the abluminal layer of the thrombus within abdominal aortic aneurysm

Background. The development of intraluminal thrombus in the abdominal aortic aneurysm (ILT) is a natural reaction to lesion of the arterial wall. Local haemostatic processes and secondary thrombolysis in the intraluminal thrombus, through the stimulation of proteolysis in extracellular matrix, may constitute one of the factors that lead to aneurysm rupture. In our study, we evaluated the coagulation and fibrinolytic parameters in the abluminal layer of the thrombus within the aneurysmal sack in order to find the differences between the thin (&#8804; 10 mm) and the thick parts. Material and methods. The sections sampled for the study were harvested from the thick (> 25 mm) and thin (&#8804; 10 mm) slices of the ILT obtained from the same 32 abdominal aortic aneurysms, namely from the layer directly adjacent to the aneurysmal wall. The tissue factor activity, antiheparin and antithrombin activity, plasminogen content, plasminogen activator levels and concentration of D-dimers in the samples were measured. Results. The activities of the tissue factor and antiheparin activity in the abluminal layer of the ILT were statistically significantly higher in the thin thrombi than in the thick ones (p < 0.001). Thin thrombi revealed significantly higher plasminogen (p < 0.001) and D-dimer (p < 0.01) concentrations when compared to thick thrombi, while the activity of plasminogen activators was higher in the thick thrombi (p < 0.05). Conclusions. The abluminal layer of the thin thrombus (up to 10 mm) of the abdominal aortic aneurysm shows higher activities of coagulative processes when compared to thicker thrombi (> 25 mm); moreover, this site reveals strong secondary activation of the fibrinolytic system. Further investigation of the association between coagulation/fibrinolytic activity and proteolysis occurring within the AAA wall requires evaluation of such processes with regard to differences in the thickness of the thrombus.Wstęp. Tworzenie się zakrzepu wewnątrz tętniaka jest naturalną reakcją na uszkodzenie ściany naczynia. Miejscowe procesy hemostatyczne i wtórna tromboliza w zakrzepie przyściennym poprzez stymulowanie proteolizy matrix pozakomórkowego mogą być też jednym z czynników prowadzących do pęknięcia tętniaka. W pracy oceniono wybrane parametry krzepnięcia i fibrynolityczne w zakrzepie, w warstwie przylegającej bezpośrednio do ściany tętniaka, poszukując różnic pomiędzy cienką, do 10 mm, a grubszą częścią zakrzepu. Materiał i metody. Do badania pobierano skrawki z grubej (ponad 25 mm) i cienkiej (do 10 mm) części zakrzepu, uzyskanego z 32 tętniaków aorty brzusznej (AAA), z warstwy przylegającej bezpośrednio do ściany tętniaka. W materiale oznaczono aktywność czynnika tkankowego (TF), aktywność antyheparynową (AH) i antytrombiny (AT), zawartość plazminogenu (Plg), stężenie aktywatorów plazminogenu (PA) i stężenie D-dimerów (DD). Wyniki. Aktywność TF i AH w przyściennej warstwie zakrzepu tętniaka były znamiennie wyższe w zakrzepach cieńszych niż grubszych (p < 0,001). W zakrzepach cieńszych stężenie Plg (p < 0,001) i D-D (p < 0,01) było znacznie wyższe niż w zakrzepach grubszych, natomiast aktywność PA była wyższa w zakrzepach grubszych (p < 0,05). Wnioski. Warstwa przyścienna cienkiego zakrzepu (do 10 mm) AAA cechuje się aktywniejszymi procesami krzepnięcia w porównaniu z grubszym (ponad 25 mm), w tym silnie wyrażoną wtórną aktywacją układu fibrynolizy. W badaniach zależności pomiędzy aktywnością procesów krzepnięcia/fibrynolizy a proteolizą ściany tętniaka powinno się uwzględniać różnice grubości zakrzepu przyściennego (ILT)

Excessive phospholipid peroxidation distinguishes ferroptosis from other cell death modes including pyroptosis

Lipid peroxidation (LPO) drives ferroptosis execution. However, LPO has been shown to contribute also to other modes of regulated cell death (RCD). To clarify the role of LPO in different modes of RCD, we studied in a comprehensive approach the differential involvement of reactive oxygen species (ROS), phospholipid peroxidation products, and lipid ROS flux in the major prototype modes of RCD viz. apoptosis, necroptosis, ferroptosis, and pyroptosis. LC-MS oxidative lipidomics revealed robust peroxidation of three classes of phospholipids during ferroptosis with quantitative predominance of phosphatidylethanolamine species. Incomparably lower amounts of phospholipid peroxidation products were found in any of the other modes of RCD. Nonetheless, a strong increase in lipid ROS levels was detected in non-canonical pyroptosis, but only during cell membrane rupture. In contrast to ferroptosis, lipid ROS apparently was not involved in non-canonical pyroptosis execution nor in the release of IL-1 beta and IL-18, while clear dependency on CASP11 and GSDMD was observed. Our data demonstrate that ferroptosis is the only mode of RCD that depends on excessive phospholipid peroxidation for its cytotoxicity. In addition, our results also highlight the importance of performing kinetics and using different methods to monitor the occurrence of LPO. This should open the discussion on the implication of particular LPO events in relation to different modes of RCD

The chemical reactivity of naphthols and their derivatives toward α-cyanocinnamonitriles and ethyl α-cyanocinnamates: A review of synthesis, reactions and applications of naphthopyrano

This review deals with synthesis and reactions of some naphthopyrano derivatives and their applications. The main purpose of this review is to present a survey of literatures on the reactivity of naphthols and their derivatives toward α-cyanocinnamonitrile or ethyl α-cyanocinnamate derivatives and the reactions of β-enaminonitriles and β-enaminoesters with different electrophiles followed by nucleophilic reagents. Some of these reactions have been applied successfully to the synthesis of biologically important compounds

Ionizing radiation results in a mixture of cellular outcomes including mitotic catastrophe, senescence, methuosis, and iron-dependent cell death

Radiotherapy is commonly used as a cytotoxic treatment of a wide variety of tumors. Interestingly, few case reports underlined its potential to induce immune-mediated abscopal effects, resulting in regression of metastases, distant from the irradiated site. These observations are rare, and apparently depend on the dose used, suggesting that dose-related cellular responses may be involved in the distant immunogenic responses. Ionizing radiation (IR) has been reported to elicit immunogenic apoptosis, necroptosis, mitotic catastrophe, and senescence. In order to link a cellular outcome with a particular dose of irradiation, we performed a systematic study in a panel of cell lines on the cellular responses at different doses of X-rays. Remarkably, we observed that all cell lines tested responded in a similar fashion to IR with characteristics of mitotic catastrophe, senescence, lipid peroxidation, and caspase activity. Iron chelators (but not Ferrostatin-1 or vitamin E) could prevent the formation of lipid peroxides and cell death induced by IR, suggesting a crucial role of iron-dependent cell death during high-dose irradiation. We also show that in K-Ras-mutated cells, IR can induce morphological features reminiscent of methuosis, a cell death modality that has been recently described following H-Ras or K-Ras mutation overexpression

Vaccination with Necroptotic Cancer Cells Induces Efficient Anti-tumor Immunity

SummarySuccessful immunogenic apoptosis in experimental cancer therapy depends on the induction of strong host anti-tumor responses. Given that tumors are often resistant to apoptosis, it is important to identify alternative molecular mechanisms that elicit immunogenic cell death. We have developed a genetic model in which direct dimerization of FADD combined with inducible expression of RIPK3 promotes necroptosis. We report that necroptotic cancer cells release damage-associated molecular patterns and promote maturation of dendritic cells, the cross-priming of cytotoxic T cells, and the production of IFN-γ in response to tumor antigen stimulation. Using both FADD-dependent and FADD-independent RIPK3 induction systems, we demonstrate the efficient vaccination potential of immunogenic necroptotic cells. Our study broadens the current concept of immunogenic cell death and opens doors for the development of new strategies in cancer therapy

Measurement of friction-induced changes in pig aorta fibre organization by non-invasive imaging as a model for detecting the tissue response to endovascular catheters

Alterations in quantity or architecture of elastin and collagen fibres are associated with some blood vessel pathologies. Also some medical interventions such as endovascular catheterization have the potential to damage blood vessels. This study reports the use of porcine aorta as a model system for studying the physical impact of catheters on vasculature, in conjunction with non-invasive imaging techniques to analyse collagen and elastin fibre organization and assess load-induced changes. Porcine aorta was exposed to frictional trauma and elastin and collagen fibre orientation evaluated by destructive, histochemical methods and non-invasive imaging. The latter allowed the immediate impact of force on fibre orientation and fibre recovery to be evaluated longitudinally. In normal aorta, elastin fibres are aligned at the surface, but become less aligned with increasing depth, showing no alignment by ~30 µm. Collagen fibres meanwhile appear aligned down to a depth of 35 µm. Changes in collagen and elastin fibre orientation in healthy pig aorta were detected by conventional destructive histology within 5 minutes of application of a sliding 10N load, while lesser loads had less impact. Good recovery of fibre orientation was observed within 20 minutes. Non-invasive imaging of ex vivo aorta tissue provides a good indication of the extent of fibre re-organization following frictional stress, at loads similar to those encountered during medical interventions such as catheterization. These results indicate that tissue deformation can occur from these procedures, even in healthy tissue, and highlight the potential for the development of an in vivo probe capable of monitoring vascular changes in patients

Mechanism of Heparin Acceleration of Tissue Inhibitor of Metalloproteases-1 (TIMP-1) Degradation by the Human Neutrophil Elastase

Heparin has been shown to regulate human neutrophil elastase (HNE) activity. We have assessed the regulatory effect of heparin on Tissue Inhibitor of Metalloproteases-1 [TIMP-1] hydrolysis by HNE employing the recombinant form of TIMP-1 and correlated FRET-peptides comprising the TIMP-1 cleavage site. Heparin accelerates 2.5-fold TIMP-1 hydrolysis by HNE. The kinetic parameters of this reaction were monitored with the aid of a FRET-peptide substrate that mimics the TIMP-1 cleavage site in pre-steady-state conditionsby using a stopped-flow fluorescence system. The hydrolysis of the FRET-peptide substrate by HNE exhibits a pre-steady-state burst phase followed by a linear, steady-state pseudo-first-order reaction. The HNE acylation step (k2 = 21±1 s−1) was much higher than the HNE deacylation step (k3 = 0.57±0.05 s−1). The presence of heparin induces a dramatic effect in the pre-steady-state behavior of HNE. Heparin induces transient lag phase kinetics in HNE cleavage of the FRET-peptide substrate. The pre-steady-state analysis revealed that heparin affects all steps of the reaction through enhancing the ES complex concentration, increasing k1 2.4-fold and reducing k−1 3.1-fold. Heparin also promotes a 7.8-fold decrease in the k2 value, whereas the k3 value in the presence of heparin was increased 58-fold. These results clearly show that heparin binding accelerates deacylation and slows down acylation. Heparin shifts the HNE pH activity profile to the right, allowing HNE to be active at alkaline pH. Molecular docking and kinetic analysis suggest that heparin induces conformational changes in HNE structure. Here, we are showing for the first time that heparin is able to accelerate the hydrolysis of TIMP-1 by HNE. The degradation of TIMP-1is associated to important physiopathological states involving excessive activation of MMPs