Neuroinflammation in the anterior cingulate cortex: the potential supraspinal mechanism underlying the mirror-image pain following motor fiber injury

Background: Peripheral nerve inflammation or lesion can affect contralateral healthy structures, and thus results in mirror-image pain. Supraspinal structures play important roles in the occurrence of mirror pain. The anterior cingulate cortex (ACC) is a first order cortical region that responds to painful stimuli. In the present study, we systematically investigate and compare the neuroimmune changes in the bilateral ACC region using unilateral- (spared nerve injury, SNI) and mirror-(L5 ventral root transection, L5-VRT) pain models, aiming to explore the potential supraspinal neuroimmune mechanism underlying the mirror-image pain. Methods: The up-and-down method with von Frey hairs was used to measure the mechanical allodynia. Viral injections for the designer receptors exclusively activated by designer drugs (DREADD) were used to modulate ACC pyramidal neurons. Immunohistochemistry, immunofluorescence, western blotting, protein microarray were used to detect the regulation of inflammatory signaling.Results: Increased expressions of tumor necrosis factor alpha (TNF-α), interleukin-6 (IL-6) and chemokine CX3CL1 in ACC induced by unilateral nerve injury were observed on the contralateral side in the SNI group but on the bilateral side in the L5-VRT group, representing a stronger immune response to L5-VRT surgery. In remote ACC, both SNI and L5-VRT induced robust bilateral increase in the protein level of Nav1.6 (SCN8A), a major voltage-gated sodium channel (VGSC) that regulates neuronal activity in the mammalian nervous system. However, the L5-VRT-induced Nav1.6 response occurred at PO 3d, earlier than the SNI-induced one, 7 days after surgery. Modulating ACC pyramidal neurons via DREADD-Gq or DREADD-Gi greatly changed the ACC CX3CL1 levels and the mechanical paw withdrawal threshold. Neutralization of endogenous ACC CX3CL1 by contralateral anti-CX3CL1 antibody attenuated the induction and the maintenance of mechanical allodynia and eliminated the upregulation of CX3CL1, TNF-α and Nav1.6 protein levels in ACC induced by SNI. Furthermore, contralateral ACC anti-CX3CL1 also inhibited the expression of ipsilateral spinal c-Fos, Iba1, CD11b, TNF-α and IL-6. Conclusions: The descending facilitation function mediated by CX3CL1 and its downstream cascade may play a pivotal role, leading to enhanced pain sensitization and even mirror-image pain. Strategies that target chemokine-mediated ACC hyperexcitability may lead to novel therapies for the treatment of neuropathic pain.

Mechanically axially chiral catenanes and noncanonical mechanically axially chiral rotaxanes

The term chiral was introduced by Lord Kelvin over a century ago to describe objects that are distinct from their own mirror image. Chirality is relevant in many scientific areas, but particularly chemistry because different mirror image forms of a molecule famously have different biological properties. Chirality typically arises in molecules due to a rigidly chiral arrangement of covalently bonded atoms. Less generally appreciated is that molecular chirality can arise when molecules are threaded through one another to create a mechanical bond. For example, when two molecular rings with chemically distinct faces are joined like links in a chain the resulting structure is chiral even when the rings themselves are not. We re-examined the symmetry properties of such mechanically axially chiral catenanes and in doing so identified a straightforward route to these molecules from simple building blocks. This also led to the discovery of a previously overlooked mechanical stereogenic unit that can arise when such a ring encircles a dumbbell-shaped axle to generate a rotaxane. These insights allowed us to produce the first highly enantioenriched axially chiral catenane and the same approach gave access to a molecule containing the newly identified noncanonical axially chiral rotaxane motif. With methods to access these structures in hand, the process of exploring their properties and applications can now begin.

Image polaritons in van der Waals crystals

Polaritonic modes in low-dimensional materials enable strong light–matter interactions and the manipulation of light on nanometer length scales. Very recently, a new class of polaritons has attracted considerable interest in nanophotonics: image polaritons in van der Waals crystals, manifesting when a polaritonic material is in close proximity to a highly conductive metal, so that the polaritonic mode couples with its mirror image. Image modes constitute an appealing nanophotonic platform, providing an unparalleled degree of optical field compression into nanometric volumes while exhibiting lower normalized propagation loss compared to conventional polariton modes in van der Waals crystals on nonmetallic substrates. Moreover, the ultra-compressed image modes provide access to the nonlocal regime of light–matter interaction. In this review, we systematically overview the young, yet rapidly growing, field of image polaritons. More specifically, we discuss the dispersion properties of image modes, showcase the diversity of the available polaritons in various van der Waals materials, and highlight experimental breakthroughs owing to the unique properties of image polaritons.

Emergency thrombectomy for cerebrovascular occlusion in a patient with mirror-image dextrocardia: a case report

Cases of patients complicated with dextrocardia who suffer from acute cerebral infarction with large vessel occlusion and receive emergency thrombectomy are particularly rare and have not been widely reported. This article aimed to increase the awareness and knowledge of these cases. We report the case of a patient with mirror-image dextrocardia who suffered from cerebral infarction with large vessel occlusion and received emergency thrombectomy. A male patient in his early 60s with dextrocardia had acute cerebral infarction with posterior circulation large vessel occlusion and underwent emergency thrombectomy. During the operation, the rapid confirmation of dextrocardia and use of flexible interventional instruments helped establish a pathway for blood flow. We used an intracranial thrombectomy stent and intracranial balloon dilation catheter to restore the cerebral blood supply. The Modified Rankin Scale score was 0 at 3 months after thrombectomy, indicating a good prognosis of the patient. Acute cerebral infarction with large vessel occlusion in patients with dextrocardia is extremely rare. Emergency thrombectomy is feasible to recanalize cerebral blood flow and give patients a chance to recover.

Prevalence of partial edentulism among the patients visiting a Tertiary Health Care Center in the Western Region, Nepal

Introduction: Tooth loss causes impairment, functional limitation, physical, psychological, and social disability. Hence, the study of pattern of tooth loss can provide a rough information about the frequency, cause and magnitude of oral problems, its sequelae that eventually can act as mirror image of prosthodontic treatment needs. Objectives: To assess the prevalence of partial edentulism and its etiology, to determine its association with sociodemographic parameters, and to find out the motivational factor/s for replacement in willing patients. Methods: Total 417 patients with partial edentulism were examined intraorally on the basis of Kennedy’s classification with Applegate’s modification. The descriptive analysis was done using frequency distribution. Pearson Chi-square analysis test was used to determine the association between demographic variables and type of tooth loss where p-value ≤0.05 was considered statistically significant. Results: Partial edentulism was more prevalent in mandibular arch (41.7%) followed by both arches (30.9%). Kennedy’s Class III was the commonest and Kennedy’s class III modification 1 was second most common type of partial edentulism. Age and educational status had statistically significant association while gender had no association with various classes of partial edentulism. Dental caries (62.8%) followed by periodontitis (25.9%) were the major causes of tooth loss. Functional demand (46.8%) was the key motivational factor for the replacement among those who were willing (78.4%). Conclusions: This study can help in assessing the epidemiological features of partial edentulism of one community in a more classified form and can help gather information necessary to assess the treatment needs.

Development of production skills in the absence of precise phonolexical representations

The study investigates the relationship between lexical encoding and production in order to establish whether learners are able to produce a difficult contrast in words that they merged in their mental lexicon. Forty American English learners of Russian were tested on their production and lexical encoding of familiar and highly-frequent words with the plain/palatalized contrast in second language (L2) Russian. Results suggest that the relationship between phonolexical encoding and production is less straightforward than a simple mirror image and is strongly affected by the prosodic position of the target consonants. In word-final position, learners did not lexically encode the difference between plain and palatalized consonants but they strived to produce it, although not very successfully. In intervocalic position, learners’ ability to encode and produce words with the plain/palatalized contrast was more accurate than in word-final position, which was attributed to the ‘spelling trap’ effect. Since Russian orthography employs vowel graphemes to mark the plain/palatalized status of preceding consonants, it appears that learners relied on these assumed vowel differences to articulate complex palatalization gestures. Thus, the findings of this study suggest that L2 learners can produce a contrast that they have not yet lexically encoded.

Epidemiologic Factors and Ocular Manifestations of Twin Children Compared with Controls

Purpose: To compare the epidemiological and ocular findings of twin children with non- twin age matched individuals as their control.Methods: In this cross sectional study, a total of 92 twins (184 cases) were compared with 182 non- twin matched children. The comprehensive ophthalmic examinations including measurement of the best corrected visual acuity (BCVA), cycloplegic refraction, ocular deviation, strabismus as well as the anterior and posterior ophthalmic examinations were conducted. An organized questionnaire was also filled out for both groups to record their demographic information. Monozygotic twins were considered if there were similarity of their phenotypic characteristics and gender, otherwise the twins were considered as dizygotic. The mirror- image twins (MIT) was defined based on the laterality of symmetrical ocular characteristics of twins.Results: In this study, the mean age of the study subjects was 7.08±4.68 and 7.56±4.02 years in the twins and non-twins groups, respectively. Among the twins 27 (30%) were monozygotic. Refractive form of MIT was seen in 5 twins (5%). BCVA in the twins group (0.07±0.16LogMAR) was significantly worse than non-twins (0.03±0.08LogMAR, P<0.001) and higher percentage of them were amblyopic (21.8% versus 10.5%, P=0.005). Twin and controls had history of strabismus surgery in 7.8% and 3.3%, respectively (P=0.009). Multivariate analysis showed significant correlation among low gestational age and female gender, low birth weight and seizure. Conclusion: Female sex, less gestational age, low birth weight, amblyopia and strabismus were significantly higher in twins. Therefore, it is important to check their refractive error, anisometropia, MIT phenomenon and amblyopia to prevent their further complications.

Psychoanalytic and Existentialist Versions of Don Juanism: Lesia Ukrainka’s The Stone Host

The article substantiates the necessity of psychoanalytical and existential methodology in interpreting Lesia Ukrainka’s drama Kaminnyi hospodar (1912; The Stone Host), including the works of José Ortega y Gasset and Miguel de Unamuno on Don Quixote, Albert Camus on absurd characters (The Myth of Sisyphus. Essay on the Absurd), and Jacques Lacan’s The Mirror Stage. Biographical data testify to the critical attitude of the writer to world treatments of the legend. Her challenge to tradition was bold and conscious. It is regarded that the main point of Lesia Ukrainka’s polemics with tradition concerns Don Juan apologetics, introduced by romantics and developed by modernists. Exploring Don Juan’s psychological makeup provides the opportunity to show that all participants of the legend have become victims of Don Juan apologetics (that distinguish the tragic fi nale of the story). The Don Juan myth has played an integral role in the image of the Person (social mask) being accepted by characters as a trustful image of the Self. Interpretation of the Mirror Image in The Stone Host and its crucial role in the final scene allows for justifying that the mirror serves the narcissistic characters’ admiration of themselves and shows them not only an attractive appearance but an ideal version of the Self, created by myth.