Current applications and future prospects of stem cells in dentistry

Stem cells are defined as clonogenic, unspecialized cells capable of both self-renewal and multi-lineage differentiation, contributing to regenerating specific tissues. For years, restorative treatments have exploited the lifelong regenerative potential of dental pulp stem cells to give rise to tertiary dentine, which is therapeutically employed for direct and indirect pulp capping. Current applications of stem cells in endodontic research have revealed their potential to continue root development in necrotic immature teeth and transplanted/replanted teeth. Successful application of pulp revascularization is highlighted here with support of a clinical case report. This article also discusses the role of dental stem cells as a promising tool for regeneration of individual tissue types like dentine, pulp and even an entire functional tooth. CPD/Clinical Relevance: This article will help practising dental surgeons understand the significance of stem cells in dentistry. Clinicians can harness the potential of stem cells using procedures like pulp regeneration/revascularization in endodontics and improve their knowledge on the recent advances in tissue engineering and future applications of dental-derived stem cells. </jats:p

POTENTIAL ANTI-TUMOR AND ANTI-INFLAMMATORY ACTIVITY OF SIX MISTLETOE PLANTS IN THE FAMILY VISCACEAE PRESENT IN WESTERN GHATS, INDIA

ABSTRACTObjectivesTo find out the cytotoxicity, anti-tumor and anti-inflammatory activities of six species of plants belongs to Viscaeceae family available in Western Ghats (India).MethodsIn vitro cytotoxicity of Viscum extracts was studied by trypan blue exclusion method and MTT assay using various cell lines. Anti-tumor activity was determined using Ehrlich ascites carcinoma (EAC) and Dalton's lymphoma ascites (DLA) cells in mice. Anti-inflammatory activities of Viscum extracts were studied using carrageenan and dextran induced mouse paw edema models in mice.ResultsAll six Viscaeceae plant extracts studied were cytotoxic towards transformed cell lines like DLA and EAC as well as to MCF-7, MDA-MB-231 and SKBR3 cell lines. V.orientale, V.nepalense and V.ramosissimum, V.trilobatum were cytotoxic towards normal cells while V.angulatum and V.capitellatum were found to be nontoxic. Excepting V.angulatum all the other species selected here showed toxicity to animals. Administration of nontoxic concentration of extracts of Viscaeceae plants significantly (P&lt;0.001) increased the lifespan of ascites tumor bearing animals and reduced DLA cells induced solid tumor development. All these plants except V.capitallatum and V.trilobatum showed significant (P&lt;0.001) anti-inflammatory activity against carrageenan and dextran models and reduced pro-inflammatory cytokine levels.ConclusionOut of six species studied four species of Viscum species studied were cytotoxic to tumour cells and inhibited tumour development. Of the six species studied V. angulatum was non-toxic to animals and showed maximum efficiency as an antitumour agent. These plants showed significant anti-inflammatory activity and reduced inflammatory markers

Convergence of age-sex distributions and population change in the presence of migration

In recent years considerable interest has been shown for analytical research in demography. With the increased application of matrix methods, it is becoming possible to investigate problems more thoroughly than before. In the earlier studies, the effects of fertility and mortality on the growth and age-sex composition of human populations were examined extensively both through theoretical and empirical investigations. But it appeared that the effects of introducing migration into the process of population change had not received the same attention. When migration was included, two procedures had been used: one in which a set of age-sex-specific net migration rates was assumed, and another in which an overall net migration rate and an age-sex composition of net migrants (i.e. of net number of migrants) were assumed. In almost all theoretical investigations the first procedure had been followed. This reduced the mathematical difficulties because the age-sex-specific net migration rates, suitably defined, could be incorporated into the survival rates. But the procedure is not suited to examine the effects of either a given overall net migration rate or of a specified age-sex composition of net migrants on the growth and the changes in the age-sex distribution of a population. These can be studied only when the second procedure is adopted. Hence, an attempt is made in this study to examine, analytically, the effects of migration on the growth and the changes in the age-sex structure of a population when migration is specified by an overall net migration rate and an age-sex composition of net migrants at the time of migration. The results in the absence of migration are used as the standard of reference to compare the effects of migration. The investigations are carried through the use of deterministic models of one sex and two sexes. The one-sex case is used only for analytical convenience, and the results are always extended to the two-sex case. "The outcomes of numerical illustrations using the two-sex model are presented. The effects of migration when it is specified by age-sex-specific net migration rates, are also given for comparison. After presenting, in Chapter 2, the results of an analysis of the numerical data used in the illustrations, the problem of the convergence of age-sex distributions is taken up for investigation. In Chapter 3, the following questions are studied: Whether, as in the case of a closed population, an unchanging age-sex distribution and a constant growth rate are evolved if a constant set of fertility, mortality and migration schedules operates on an arbitrary age-sex distribution over a long period of time?, and How would the time required for this convergence (the duration of convergence) be changed due to the inclusion of migration into the population process? Then Chapter 4 deals with a natural generalization and examines the convergence of two arbitrary age-sex distributions when they are subjected to identical schedules of fertility, mortality and migration that are varying over time. The changes in the duration of convergence due to the presence of migration are studied in this case also. Next, the relationship between the growth and the changes in the age-sex structure of a population on the one hand, and the operating schedules of fertility, mortality and migration on the other, is examined both when the operating conditions remain constant over time and vary over time. Under the assumption of constant schedules, two situations are considered: one in which a set of single schedule of each of the components operates constantly over time, and another in which a set of k schedules of each operates repeatedly over time. In the first case, a constant growth rate (i.e., the intrinsic growth rate) and a constant age-sex distribution (i.e., the equilibrium state age-sex distribution) are evolved, while in the second a stable set of k growth rates and k age-sex distributions is evolved. Hence, Chapter 5 concentrates on the derivation of expressions which show explicitly the relationship between these characteristics of the ultimate populations and the given schedules of fertility, mortality and migration. On the other hand, when the operating schedules are changing over time, no fixed growth rate or age-sex distribution is obtained. But both are changed over time due to the operation of the components of change. Hence, in the final chapter, an attempt is made to assess the contribution of the changes in the components during a certain period of time towards the changes in the characteristics of the population during that period. A method called the factorial projections method, is suggested for this purpose and is applied to study the changes in the population of Australia during 1911-66

Extraction versus non-extraction orthodontic treatment:A systematic review and meta-analysis

Objectives: To compare four first premolar extraction and non-extraction treatment effects on intraarch width, profile, treatment duration, occlusal outcomes, smile aesthetics and stability.Materials and Methods: Electronic search of literature to June 2nd, 2023 was conducted, using health science databases with additional search of grey literature, unpublished material and hand searching, for studies reporting non-surgical patients with fixed appliances regarding sixteen sub outcomes. Data extraction utilized customized forms, quality assessed with ROBINS-I and Cochrane RoB 2. GRADE assessed certainty of evidence.Results: Thirty (29 RS, 1 RCT) studies were included. Random effect meta-analysis (95%CI) demonstrated maxillary (MD -2.03mm;[-2.97, -1.09];P&lt;0.0001) and mandibular inter-first molar width decrease (MD -2.00mm;[-2.71, -1.30];P&lt;0.00001) with four first premolar extraction. Mandibular intercanine width increase (MD 0.68mm;[0.36, 0.99];P&lt;0.0001) and shorter treatment duration (MD 0.36years;[0.10, 0.62];P=0.007) in non-extraction group. Narrative synthesis included three and five studies for upper and lower lips-E plane, respectively. For ABO-OGS and maxillary/mandibular anterior alignment (Little’s Irregularity Index) each included two studies with inconclusive evidence. No eligible studies for UK PAR score. Class I subgroup/sensitivity analyses favoured same results. Prediction interval indicated no significant difference for all outcomes.Conclusions: Four first premolar extraction results in maxillary and mandibular inter-first molar width decrease and retraction of upper/lower lips. Non-extraction treatment results in mandibular intercanine width increase and shorter treatment duration. No significant difference between the two groups regarding maxillary intercanine width, US PAR score and posttreatment smile aesthetics. Further high-quality focused research recommended

Pros and Cons on Use of Live Viral Vaccines in Commercial Chicken Flocks.

The poultry industry is the largest source of meat and eggs for the growing human population worldwide. Key concerns in poultry farming are nutrition, management, flock health, and biosecurity measures. As part of the flock health, use of live viral vaccines plays a vital role in the prevention of economically important and common viral diseases. This includes diseases and production losses caused by Newcastle disease virus, infectious bronchitis virus, infectious laryngotracheitis virus, infectious bursal disease virus, Marek's disease virus, chicken infectious anemia virus, avian encephalomyelitis virus, fowlpox virus, and avian metapneumovirus. These viruses cause direct and indirect harms, such as financial losses worth millions of dollars, loss of protein sources, and threats to animal welfare. Flock losses vary by type of poultry, age of affected animals, co-infections, immune status, and environmental factors. Losses in broiler birds can consist of high mortality, poor body weight gain, high feed conversion ratio, and increased carcass condemnation. In commercial layers and breeder flocks, losses include higher than normal mortality rate, poor flock uniformity, drops in egg production and quality, poor hatchability, and poor day-old-chick quality. Despite the emergence of technology-based vaccines, such as inactivated, subunit, vector-based, DNA or RNA, and others, the attenuated live vaccines remain as important as before. Live vaccines are preferred in the global veterinary vaccine market, accounting for 24.3% of the global market share in 2022. The remaining 75% includes inactivated, DNA, subunit, conjugate, recombinant, and toxoid vaccines. The main reason for this is that live vaccines can induce innate, mucosal, cellular, and humoral immunities by single or multiple applications. Some live vaccine combinations provide higher and broader protection against several diseases or strains of viruses. This review aimed to explore insights on the pros and cons of attenuated live vaccines commonly used against major viral infections of the global chicken industry, and the future road map for improvement

Adjunctive primary stenting of Zenith endograft limbs during endovascular abdominal aortic aneurysm repair: Implications for limb patency

ObjectiveEndograft limb occlusion is an infrequent but serious complication of endovascular abdominal aortic aneurysm (AAA) repair. The insertion of additional stents within the endograft limb may prevent future occlusion. This study evaluates limb patency with and without adjunctive stenting of endograft limbs at the time of endovascular AAA repair.MethodsWe performed a retrospective review of 248 patients who underwent endovascular abdominal aortic aneurysm repair with the Zenith AAA endovascular graft between 1999 and 2004. Among these patients, two groups were identified: 64 patients with adjunctive stents placed in 85 limbs and 184 patients without additional bare stent placement in endograft limbs at the time of endovascular AAA repair.ResultsWomen comprised 23% of stented and 11% of unstented patients (P = .02). The mean length of follow-up in the stented and unstented groups was 2.0 years. There were 13 instances of limb thrombosis in 13 patients (5.2% of patients, 2.7% of limbs), all in the unstented group. No limb occlusions occurred in the presence of adjunctive bare metal stents. Seventy-three percent of the occlusions occurred ≤6 months of endovascular AAA repair. Two patients (15%) had no symptoms of lower-extremity ischemia despite graft limb occlusion and did not undergo intervention. The others underwent thrombectomy (n = 2), thrombectomy with bare stent placement (n = 3), femoral-femoral bypass (n = 4), thrombolysis (n = 1), and thrombolysis with bare stent placement (n = 1). Of the seven who underwent thrombectomy or thrombolysis, three had no additional stents placed at the secondary procedure, and two of these three went on to rethrombose. By life-table analysis, primary patency at 3 years in the stented and nonstented limbs was 100% ± 0% and 94% ± 3%, respectively (P = .05).ConclusionsThe intraoperative insertion of additional bare metal stents appeared to eliminate the risk of thrombosis and was without complication. Of the 85 stented limbs in this series, not one occluded. The overall rate of limb thrombosis was low, with most limb occlusions occurring ≤6 months of stent-graft insertion, and would probably have been even lower had we been able to identify all high-risk cases for prophylactic adjunctive stenting. Limb occlusion denotes an underlying problem with the graft, which if left untreated after thrombectomy or thrombolysis will lead to rethrombosis. Postoperative imaging was of little value in detecting impending limb occlusion. Based on these findings, we believe one should identify and stent any limbs that appear to be at risk for thrombosis, but this study lacks the data to predict which limbs need stenting

Evaluation of protection and immunity induced by infectious bronchitis vaccines administered by oculonasal, spray or gel routes in commercial broiler chicks.

Broiler chicks' responses following combined IBV live attenuated Massachusetts and 793B strains through gel, spray or oculonasal (ON) vaccination routes were cross-compared. Subsequently, the responses following IBV M41 challenge of the unvaccinated and vaccinated groups were also assessed. Post-vaccination humoral and mucosal immune responses, alongside viral load kinetics in swabs and tissues, were determined using commercial ELISA assays, monoclonal antibody-based IgG and IgA ELISA assays and qRT-PCR respectively. After challenged with IBV-M41 strain, humoral and mucosal immune responses, ciliary protection, viral load kinetics, and immune gene mRNA transcriptions between the three vaccination methods were examined and compared. Findings showed that post-vaccinal humoral and mucosal immune responses were similar in all three vaccination methods. Post vaccinal viral load kinetics is influenced by method of administration. The viral load peaked in the ON group within the tissues and the OP/CL swabs in the first and third weeks respectively. Following M41 challenge, ciliary protection and mucosal immune responses were not influenced by vaccination methods as all three methods offered equal ciliary protection. Immune gene mRNA transcriptions varied by vaccination methods. Significant up-regulation of MDA5, TLR3, IL-6, IFN-α and IFN-β genes were recorded for ON method. For both spray and gel methods, significant up-regulation of only MDA5 and IL-6 genes were noted. The spray and gel-based vaccination methods gave equivalent levels of ciliary protection and mucosal immunity to M41 virulent challenge comparable to those provided by the ON vaccination. Analysis of viral load and patterns of immune gene transcription of the vaccinated-challenged groups revealed high similarity between turbinate and choanal cleft tissues compared to HG and trachea. With regards to immune gene mRNA transcription, for all the vaccinated-challenged groups, similar results were found except for IFN-α, IFN-β and TLR3, which were up-regulated only in ON compared to gel and spray vaccination methods

A viral CTL escape mutation leading to immunoglobulin-like transcript 4-mediated functional inhibition of myelomonocytic cells

Viral mutational escape can reduce or abrogate recognition by the T cell receptor (TCR) of virus-specific CD8+ T cells. However, very little is known about the impact of cytotoxic T lymphocyte (CTL) epitope mutations on interactions between peptide–major histocompatibility complex (MHC) class I complexes and MHC class I receptors expressed on other cell types. Here, we analyzed a variant of the immunodominant human leukocyte antigen (HLA)-B2705–restricted HIV-1 Gag KK10 epitope (KRWIILGLNK) with an L to M amino acid substitution at position 6 (L6M), which arises as a CTL escape variant after primary infection but is sufficiently immunogenic to elicit a secondary, de novo HIV-1–specific CD8+ T cell response with an alternative TCR repertoire in chronic infection. In addition to altering recognition by HIV-1–specific CD8+ T cells, the HLA-B2705–KK10 L6M complex also exhibits substantially increased binding to the immunoglobulin-like transcript (ILT) receptor 4, an inhibitory MHC class I–specific receptor expressed on myelomonocytic cells. Binding of the B2705–KK10 L6M complex to ILT4 leads to a tolerogenic phenotype of myelomonocytic cells with lower surface expression of dendritic cell (DC) maturation markers and co-stimulatory molecules. These data suggest a link between CTL-driven mutational escape, altered recognition by innate MHC class I receptors on myelomonocytic cells, and functional impairment of DCs, and thus provide important new insight into biological consequences of viral sequence diversificatio