Dopamine neurons drive spatiotemporally heterogeneous striatal dopamine signals during learning.

Environmental cues, through Pavlovian learning, become conditioned stimuli that invigorate and guide animals toward acquisition of rewards. Dopamine neurons in the ventral tegmental area (VTA) and substantia nigra (SNC) are crucial for this process. Dopamine neurons are embedded in a reciprocally connected network with their striatal targets, the functional organization of which remains poorly understood. Here, we investigated how learning during optogenetic Pavlovian cue conditioning of VTA or SNC dopamine neurons directs cue-evoked behavior and shapes subregion-specific striatal dopamine dynamics. We used a fluorescent dopamine biosensor to monitor dopamine in the nucleus accumbens (NAc) core and shell, dorsomedial striatum (DMS), and dorsolateral striatum (DLS). We demonstrate spatially heterogeneous, learning-dependent dopamine changes across striatal regions. While VTA stimulation evoked robust dopamine release in NAc core, shell, and DMS, cues predictive of this activation preferentially recruited dopamine release in NAc core, starting early in training, and DMS, late in training. Corresponding negative prediction error signals, reflecting a violation in the expectation of dopamine neuron activation, only emerged in the NAc core and DMS, and not the shell. Despite development of vigorous movement late in training, conditioned dopamine signals did not similarly emerge in the DLS, even during Pavlovian conditioning with SNC dopamine neuron activation, which elicited robust DLS dopamine release. Together, our studies show broad dissociation in the fundamental prediction and reward-related information generated by different dopamine neuron populations and signaled by dopamine across the striatum. Further, they offer new insight into how larger-scale plasticity across the striatal network emerges during Pavlovian learning to coordinate behavior.

Fucoidan loaded PVA/Dextran blend electrospun nanofibers for the effective wound healing.

Chronic wounds have become a serious global health issue. In this study, we investigated the effect of increasing fucoidan (FD) concentration on the characteristics of nanofibers and their wound healing potential at in vitro as well as in vivo level. The results showed that increasing FD content (0.25 to 1 %) led to an significant increase in nanofiber diameter (487.7 ± 125.39 to 627.9 ± 149.78 nm), entrapment efficiency (64.26 ± 2.6 to 94.9 ± 3.1 %), and water uptake abilities (436.5 ± 1.2 to 679.7 ± 11.3 %). However, the in vitro biodegradation profile decreased with an increase in FD concentration. Water vapor transmission rate analysis showed that it was within the standard range for all FD concentrations. Nanofibers with 1 % PVA/DX/FD exhibited slow-release behavior, suggesting prolonged FD availability at the wound site. In vivo studies in rats with full-thickness wounds demonstrated that applying 1 % FD-enriched PVA/DEX nanofibers significantly (p < 0.0001) improved mean wound area closure. These findings suggest that FD-enriched nanofibers have immense potential as a wound dressing material in future if explored further.

Angiopep-2 Grafted PAMAM Dendrimers for the Targeted Delivery of Temozolomide: In Vitro and In Vivo Effects of PEGylation in the Management of Glioblastoma Multiforme.

The present study was aimed to synthesize, characterize, and evaluate the angiopep-2 grafted PAMAM dendrimers (Den, G 3.0 NH2) with and without PEGylation for the targeted and better delivery approach of temozolomide (TMZ) for the management of glioblastoma multiforme (GBM). Den-ANG and Den-PEG2-ANG conjugates were synthesized and characterized by 1H NMR spectroscopy. The PEGylated (TMZ@Den-PEG2-ANG) and non-PEGylated (TMZ@Den-ANG) drug loaded formulations were prepared and characterized for particle size, zeta potential, entrapment efficiency, and drug loading. An in vitro release study at physiological (pH 7.4) and acidic pH (pH 5.0) was performed. Preliminary toxicity studies were performed through hemolytic assay in human RBCs. MTT assay, cell uptake, and cell cycle analysis were performed to evaluate the in vitro efficacy against GBM cell lines (U87MG). Finally, the formulations were evaluated in vivo in a Sprague-Dawley rat model for pharmacokinetics and organ distribution analysis. The 1H NMR spectra confirmed the conjugation of angiopep-2 to both PAMAM and PEGylated PAMAM dendrimers, as the characteristic chemical shifts were observed in the range of 2.1 to 3.9 ppm. AFM results revealed that the surface of Den-ANG and Den-PEG2-ANG conjugates were rough. The particle size and zeta potential of TMZ@Den-ANG were observed to be 229.0 ± 17.8 nm and 9.06 ± 0.4 mV, respectively, whereas the same for TMZ@Den-PEG2-ANG were found to be 249.6 ± 12.9 nm and 10.9 ± 0.6 mV, respectively. The entrapment efficiency of TMZ@Den-ANG and TMZ@Den-PEG2-ANG were calculated to be 63.27 ± 5.1% and 71.48 ± 4.3%, respectively. Moreover, TMZ@Den-PEG2-ANG showed a better drug release profile with a controlled and sustained pattern at PBS pH 5.0 than at pH 7.4. The ex vivo hemolytic study revealed that TMZ@Den-PEG2-ANG was biocompatible in nature as it showed 2.78 ± 0.1% hemolysis compared to 4.12 ± 0.2% hemolysis displayed by TMZ@Den-ANG. The outcomes of the MTT assay inferred that TMZ@Den-PEG2-ANG possessed maximum cytotoxic effects against U87MG cells with IC50 values of 106.62 ± 11.43 µM (24 h) and 85.90 ± 9.12 µM (48 h). In the case of TMZ@Den-PEG2-ANG, the IC50 values were reduced by 2.23-fold (24 h) and 1.36-fold (48 h) in comparison to pure TMZ. The cytotoxicity findings were further confirmed by significantly higher cellular uptake of TMZ@Den-PEG2-ANG. Cell cycle analysis of the formulations suggested that the PEGylated formulation halts the cell cycle at G2/M phase with S-phase inhibition. In the in vivo studies, the half-life (t1/2) values of TMZ@Den-ANG and TMZ@Den-PEG2-ANG were enhanced by 2.22 and 2.76 times, respectively, than the pure TMZ. After 4 h of administration, the brain uptake values of TMZ@Den-ANG and TMZ@Den-PEG2-ANG were found to be 2.55 and 3.35 times, respectively, higher than that of pure TMZ. The outcomes of various in vitro and ex vivo experiments promoted the use of PEGylated nanocarriers for the management of GBM. Angiopep-2 grafted PEGylated PAMAM dendrimers can be potential and promising drug carriers for the targeted delivery of antiglioma drugs directly to the brain.

Hepatic stellate cell stearoyl co-A desaturase activates leukotriene B4 receptor 2 - ß-catenin cascade to promote liver tumorigenesis.

Hepatocellular carcinoma (HCC) is the 3rd most deadly malignancy. Activated hepatic stellate cells (aHSC) give rise to cancer-associated fibroblasts in HCC and are considered a potential therapeutic target. Here we report that selective ablation of stearoyl CoA desaturase-2 (Scd2) in aHSC globally suppresses nuclear CTNNB1 and YAP1 in tumors and tumor microenvironment and prevents liver tumorigenesis in male mice. Tumor suppression is associated with reduced leukotriene B4 receptor 2 (LTB4R2) and its high affinity oxylipin ligand, 12-hydroxyheptadecatrienoic acid (12-HHTrE). Genetic or pharmacological inhibition of LTB4R2 recapitulates CTNNB1 and YAP1 inactivation and tumor suppression in culture and in vivo. Single cell RNA sequencing identifies a subset of tumor-associated aHSC expressing Cyp1b1 but no other 12-HHTrE biosynthetic genes. aHSC release 12-HHTrE in a manner dependent on SCD and CYP1B1 and their conditioned medium reproduces the LTB4R2-mediated tumor-promoting effects of 12-HHTrE in HCC cells. CYP1B1-expressing aHSC are detected in proximity of LTB4R2-positive HCC cells and the growth of patient HCC organoids is blunted by LTB4R2 antagonism or knockdown. Collectively, our findings suggest aHSC-initiated 12-HHTrE-LTB4R2-CTNNB1-YAP1 pathway as a potential HCC therapeutic target.

Hierarchical cue control of cocaine seeking in the face of cost.

RATIONALE: Addiction is characterized by intermittent drug seeking despite rising costs. This behavior is heavily influenced by environmental stimuli that signal drug availability and reinforce drug seeking. OBJECTIVE: To establish the relationship between three key aspects of human drug use in rats: the intermittent, binge nature of drug intake, the motivational conflict of drug seeking in the face of escalating negative costs, and the ability of different drug cues to interact to modulate relapse. METHODS: Male and female rats were trained to self-administer cocaine on an intermittent access schedule, where brief drug-availability states were signaled by a shift in the ambient lighting of the environment, and cocaine infusions were signaled by a separate proximal discrete cue. Rats then went through a conflict procedure, where foot shock intensity associated with cocaine seeking was escalated until intake was suppressed. We then completed relapse tests where the drug-delivery cue was noncontingently presented alone, or in the context of dynamic drug-availability state transitions. RESULTS: Intermittent access spurred psychomotor sensitization and binge-like cocaine intake. The intensity of binge-like drug taking during training was predictive of later drug seeking despite escalating costs during conflict. In relapse tests, the ability of a proximal discrete drug cue to trigger relapse was gated by the presence of a global cue signaling drug-availability state transitions. CONCLUSIONS: Our results suggest that the pattern of drug intake plays a role in many features of addiction, including modifying an individual's willingness to endure high costs associated with drug seeking. Furthermore, our studies indicate that drug-related sensory information can be hierarchically organized to exert a dynamic modulating influence on drug-seeking motivation.

Emergence of highly profibrotic and proinflammatory Lrat+Fbln2+ HSC subpopulation in alcoholic hepatitis.

BACKGROUND AND AIMS: Relative roles of HSCs and portal fibroblasts in alcoholic hepatitis (AH) are unknown. We aimed to identify subpopulations of collagen type 1 alpha 1 (Col1a1)-expressing cells in a mouse AH model by single-cell RNA sequencing (scRNA-seq) and filtering the cells with the HSC (lecithin retinol acyltransferase [Lrat]) and portal fibroblast (Thy-1 cell surface antigen [Thy1] and fibulin 2 [Fbln2]) markers and vitamin A (VitA) storage. APPROACH AND RESULTS: Col1a1-green fluorescent protein (GFP) mice underwent AH, CCl 4 , and bile duct ligation (BDL) procedures to have comparable F1-F2 liver fibrosis. Col1a1-expressing cells were sorted via FACS by VitA autofluorescence and GFP for single-cell RNA sequencing. In AH, approximately 80% of Lrat+Thy1-Fbln2- activated HSCs were VitA-depleted (vs. ~13% in BDL and CCl 4 ). Supervised clustering identified a subset co-expressing Lrat and Fbln2 (Lrat+Fbln2+), which expanded 44-fold, 17-fold, and 1.3-fold in AH, BDL, and CCl 4 . Lrat+Fbln2+ cells had 3-15-times inductions of profibrotic, myofibroblastic, and immunoregulatory genes versus Lrat+Fbln2- cells, but 2-4-times repressed HSC-selective genes. AH activated HSCs had up-regulated inflammatory (chemokine [C-X-C motif] ligand 2 [Cxcl2], chemokine [C-C motif] ligand 2), antimicrobial (Il-33, Zc3h12a), and antigen presentation (H2-Q6, H2-T23) genes versus BDL and CCl 4 . Computational deconvolution of AH versus normal human bulk-liver RNA-sequencing data supported an expansion of LRAT+FBLN2+ cells in AH; AH patient liver immunohistochemistry showed FBLN2 staining along fibrotic septa enriched with LRAT+ cells; and in situ hybridization confirmed co-expression of FBLN2 with CXCL2 and/or human leukocyte antigen E in patient AH. Finally, HSC tracing in Lrat-Cre;Rosa26mTmG mice detected GFP+FBLN2+ cells in AH. CONCLUSION: A highly profibrotic, inflammatory, and immunoregulatory Lrat+Fbln2+ subpopulation emerges from HSCs in AH and may contribute to the inflammatory and immunoreactive nature of AH.

Orofacial Features and Their Correlation in Cardiovascular Diseases.

Background: The association between cardiovascular diseases and periodontitis had different pathophysiological mechanisms involved. These mechanisms are both inflammatory and microbial. Furthermore, the possible association between two diseases can be explained by common risk factors. Aims: The present trial was carried out to establish a relation between coronary artery disease and periodontitis. Materials and Methods: One hundred and twenty-six participants advised for the angiography were included. Periodontists determined the presence of periodontitis in all participants followed by lipid profile, C-reactive protein (CRP) levels, and blood coronary angiography was then performed. The collected data were subjected to the statistical analysis, and the results were formulated. Results: The level of CRP in participants with and without coronary artery disease was 0.66 ± 1.52 and 0.53 ± 1.01, respectively, which was nonsignificant with a P = 0.63. Nonstatistically significant difference was seen in values of cholesterol and blood glucose in participants with and without coronary artery disease (P = 0.28 and P = 0.53). The mean tooth loss in participants with coronary artery disease was 14.2 ± 6.4 and in participants with no coronary artery disease was 11.8 ± 6.5, and such difference was statistically significant (P = 0.05). Conclusion: The present study establishes an association between poor oral health, periodontitis, and coronary artery disease. This study demonstrates that tooth loss which is an important feature of periodontitis is significantly associated with coronary artery disease.

Comparison of Efficacy of Various Intracanal Irrigants with Ultrasonic Bypass System.

BACKGROUND: The long-term success of root canal therapy depends on the effective debridement and removal of smear layer and debris from the canal. Root canals with difficult anatomy and complex systems pose great challenge to achieve this. Mechanical therapy alone cannot achieve this goal, various intracanal chemicals also have their own limitations along with the difficulty in reaching the farfetched and difficult areas, and hence, introduction of ultrasonic bypass system has been a boon for the endodontic therapy. OBJECTIVES: The aim of this study is to compare the various root canal medicaments along with ultrasonic bypass system in effectively cleaning the debris and smear layer from the various parts of the root canal system. MATERIALS AND METHODS: Forty single-rooted anterior maxillary and mandibular human teeth were collected for this study, after disinfection, they were sectioned into three equal parts coronal, middle, and apical and these parts were later studies under SEM (Scanning Electron Microscope) and scoring as per the scoring criteria set before the study was done and results were then compared statistically. RESULTS: Group with both ethylenediaminetetraacetic acid (EDTA) and NaOCl with ultrasonic bypass system was the most effective one, when compared with sterile water, NaOCl + ultrasonic bypass system, EDTA + ultrasonic bypass system. NaOCl + ultrasonic bypass system was more effective as compared with the EDTA + ultrasonic bypass system. CONCLUSION: Ultrasonic bypass system is a useful tool for debris and smear layer removal from a root canal system, but its effectiveness increases when both EDTA and NaOCl are used along with it.

Quantitative Evaluation of Apically Extruded Debris in Root Canals prepared by Single-file Reciprocating and Single File Rotary Instrumentation Systems: A Comparative In vitro Study.

BACKGROUND: Prevention of the debris from extruding to the periapical region is an important aspect to be taken care of as its extrusion can result in pain, periapical inflammation, and delayed healing owing to the presence of highly infective components in the debris. AIM: The present trial was aimed to compare and assess the amount of debris extruded apically using the single-file reciprocating system - WaveOne GOLD and single file rotary system - OneShape in root canal preparations in vitro. MATERIALS AND METHODS: Thirty mandibular premolars were divided into two groups (15 samples each) prepared with a single-file reciprocating system - WaveOne GOLD and single-file rotary system - OneShape. Debris extruded was collected and then stored in an incubator. The final weight was calculated after obtaining the mean of three consecutive weights obtained for each tooth. The data were compared using the ANOVA and Turkey's post hoc analysis. RESULTS: Debris extrusions were recorded in both groups and analysis revealed statistical differences in weight before and after the instrumentation procedures in both groups. When compared, reciprocating single file - WaveOne GOLD extruded more debris than rotary single file system - OneShape with a P < 0.001. CONCLUSIONS: The rotary instrumentation systems extrude lesser debris apically than the reciprocating instrumentation system. The difference found was statistically significant.

Impact of Covid Pandemic and Working Strategies on Private Practitioners.

BACKGROUND: The COVID-19 pandemic is badly affecting more than 2 million population of 213 countries and has caused 1,952,976 deaths till January 12, 2020. India has also suffered a great loss in terms of economy and people. Furthermore, owing to the complete lockdown enforced in India, restricting humanitarian movement also affected day-to-day life of Indians with a huge impact. OBJECTIVES: The present clinical trial was carried out to evaluate the impact of the COVID-19 pandemic on private practitioners. Furthermore, changes in their practice pattern were evaluated along with the perspective of their health, role, and response to the pandemic. MATERIALS AND METHODS: The study includes a total of 120 health-care professionals of either gender. The stress and mental health of the participants was assessed using Depression Anxiety Stress Scale-21 in English format, also included the questions related to the demographic characteristics, use of technologies for providing virtual health care, changes in the working during the pandemic, and an opinion of their experiences during that period. The data collected were subjected to the analysis and were kept confidential and anonymous. RESULTS: 16.6% of participants preferred virtual consultation before the pandemic in contrast to 83.3% during the pandemic. The most preferred method remained the phone call by 15.8% (n = 19) patients. Depression was seen severely in 35% of study participants (n = 42) and 13.3% of participants extremely severe depression was seen (n = 16). Severe and extremely severe anxiety was noticed in 31.66% (=38) and 15% (18) study participants respectively, whereas severe and extremely severe stress was found in 30% (n = 36), and 12.5% (n = 15) private practitioners. The most common factor that can be considered responsible for compromised mental health in private practitioners was the possibility of infecting the society seen in 59.1% (n = 71) participants. CONCLUSION: During the pandemic breakout, private practitioners suffered a great challenge both financially and mentally, especially during the lockdown. Furthermore, a significant increase was seen in the virtual consultation methods during the pandemic breakout.

Reliability of C-reactive Protein as a Biomarker for Cardiovascular and Oral Diseases in Young and Old Subjects.

BACKGROUND: Increased C-reactive protein (CRP) levels are associated with various diseases such as cardiovascular diseases (CVDs), periodontal diseases, and other inflammatory diseases and can be an effective biomarker for predicting future risks of periodontal diseases. AIMS: The present trial was carried out to evaluate if CRP levels are lower in healthy and young individuals as compared to individuals with high body mass index (BMI), gingival index, and CVDs by assessing CRP levels in young and old individuals (more than 45 years). MATERIALS AND METHODS: A total of 174 participants were recruited for the study and were divided into three following groups: Less than 45 years healthy participants (n = 124), more than 45 years healthy participants, and more 45-year-old participants with CVDs (n = 25). The collected data were subjected to the statistical analysis. RESULTS: In Group I, females had a CRP level of 8476 ± 6.86 pg, females of Group II had a CRP value of 13,262 ± 3.76, and in females of Group III CRP value was 22,761 ± 6.24 pg. These values, respectively, for males were 8494 ± 7.68, 13,840 ± 4.82, and 13,839 ± 3.8. In smokers, the CRP values for Group I, II, and III were 29,012 ± 14.66, 12,568 ± 4.16, and 16,826 ± 3.42, respectively. CONCLUSION: CRP levels were higher in males as compared to females. Higher BMI was associated with higher values of CRP. The participants with higher BMI presented higher CRP values irrespective of age.

Evaluation of Remineralization Seen in Dentin Related to Ceramic Restorations.

BACKGROUND: Recently, the caries management had shifted from extension for prevention to early detection and remineralization of remaining tooth structure using noninvasive techniques. AIM: The present trial was carried out to assess the effect of adding mono-n-Dodecyl phosphate as a surfactant to ceramic on remineralization of dentin. MATERIALS AND METHODS: The 32 teeth were divided into the following four groups randomly (n = 8 each group) - Group I: cavities not restored, Group II: Restored with ceramic, Group III: restored with ceramic and 2% mono-n-Dodecyl phosphate, and Group IV: restored with ceramic and 5% mono-n-Dodecyl phosphate. Knoop indenter microhardness tests were done at 10, 20, and 40 days. The surface was evaluated under scanning electron microscope. The collected data were subjected to statistical evaluation, and the results were formulated. RESULTS: In ceramic restored (Group II), an increase in Knoop microhardness (KHN) values was seen at 10-, 20-, and 40-day assessment with the respective values of 102.2 ± 20.3, 118.7 ± 19.4, and 127 ± 15.1. Similarly, a constant increase at different assessments was observed for Groups III and IV with 2% and 5% of mono-n-Dodecyl phosphate with ceramic with a 40-day KHN value of 128.2 ± 21.4 for Group III and 113.5 ± 17.3 for Group IV. A statistically significant difference was seen between ceramic and 5% mono-n-Dodecyl phosphate (Group IV) with hardness values of 30.31%, 29.8%, and 21.78% for Groups II, III, and IV, respectively, at 20 days. CONCLUSION: The present study concludes that ceramic restorations are effective in promoting dentin remineralization. However, the addition of only 2% mono-n-Dodecyl phosphate was beneficial, whereas 5% mono-n-Dodecyl phosphate reduced the efficacy of ceramic on dentin remineralization.

Differential Expression of SWI/SNF Chromatin Remodeler Subunits Brahma and Brahma-Related Gene During Drug-Induced Liver Injury and Regeneration in Mouse Model.

The chromatin remodeling activity of mammalian SWI/SNF complex is carried out by either Brahma (BRM) or Brahma-related gene (BRG-1). The BRG-1 regulates genes involved in cell proliferation, whereas BRM is associated with cell differentiation, and arrest of cell growth. Global modifications of histones and expression of genes of chromatin-remodeling subunits have not been studied in in vivo model systems. In the present study, we investigate epigenetic modifications of histones and the expression of genes in thioacetamide (TAA)-induced liver injury and regeneration in a mouse model. In the present study, we report that hepatocyte proliferation and H3S10 phosphorylation occur during 60 to 72 h post TAA treatment in mice. Furthermore, there was change in the H3K9 acetylation and H3K9 trimethylation pattern with respect to liver injury and regeneration phase. Looking into the expression pattern of Brg-1 and Brm, it is evident that they contribute substantially to the process of liver regeneration. The SWI/SNF remodeler might contain BRG-1 as its ATPase subunit during injury phase. Whereas, BRM-associated SWI/SNF remodeler might probably be predominant during decline of injury phase and initiation of regeneration phase. Furthermore, during the regeneration phase, BRG-1-containing remodeler again predominates. Considering all these observations, the present study depicts an interplay between chromatin interacting machineries in different phases of thioacetamide-induced liver injury and regeneration.

An in vitro Comparison of Endodontic Medicaments Propolis and Calcium Hydroxide alone and in Combination with Ciprofloxacin and Moxifloxacin against Enterococcus Faecalis.

AIM: To evaluate and compare the antimicrobial properties of propolis and calcium hydroxide alone and in combination with ciprofloxacin and moxifloxacin against Enterococcus faecalis (E. Faecalis). MATERIALS AND METHODS: The laboratory study was carried out to test the effectiveness of propolis and calcium hydroxidealone as well as in combination with the established endodontic medicaments (moxifloxacin and ciprofloxacin). The various combinations were-group 1: propolis, group 2: calcium hydroxide, group 3: moxifloxacin, group 4: ciprofoxacin, group 5: propolis + moxifloxacin, group 6: propolis + Ciprofloxacin, group 7: calcium hydroxide + ciprofloxacin, group 8: calcium hydroxide + moxifloxacin. The efficacy of these medicaments was tested by checking for the zone of inhibition for the specific strain (ATCC 29212) of E. faecalis at different time intervals, i.e. 24, 48 and 72 hours. RESULTS: Mean zone of inhibition was maximum in group V (21.94 ± 4.26) followed by group VI (18.80 ± 1.93), group I (18.71 ± 4.26), group VIII (15.88 ± 2.59), group III (14.91 ± 1.00), group VII (14.57 ± 2.17), group IV (13.91 ± 1.00) and minimum in group II (12.89 ± 2.14). Mean zone of inhibition was found to be maximum at 72 hours and minimum at 24 hours. At all time intervals, the combination of Propalis with Moxifocacin showed the maximum antimicrobial efficacy. CONCLUSION: On the basis of the results of the present study, it can be concluded that propolis and calcium hydroxide show synergistic effect with moxifloxacin and ciprofloxacin against E. Faecalis. Propolis in combination with antibiotics and alone is more effective than calcium hydroxide. CLINICAL SIGNIFICANCE: Since propolis alone and in combination with antibiotics was observed to be more effective than calcium hydroxide, propolis can be considered as an intracanal medicament when compared to traditional calcium hydroxide.