Category: Nevin Manimala

J R Stat Soc Series B Stat Methodol. 2017 Nov;79(5):1415-1437. doi: 10.1111/rssb.12224. Epub 2016 Dec 26.

ABSTRACT

This paper proposes a decorrelation-based approach to test hypotheses and construct confidence intervals for the low dimensional component of high dimensional proportional hazards models. Motivated by the geometric projection principle, we propose new decorrelated score, Wald and partial likelihood ratio statistics. Without assuming model selection consistency, we prove the asymptotic normality of these test statistics, establish their semiparametric optimality. We also develop new procedures for constructing pointwise confidence intervals for the baseline hazard function and baseline survival function. Thorough numerical results are provided to back up our theory.

PMID:37854943 | PMC:PMC10584375 | DOI:10.1111/rssb.12224

J Oral Maxillofac Pathol. 2023 Apr-Jun;27(2):307-314. doi: 10.4103/jomfp.jomfp_368_22. Epub 2023 Jul 13.

ABSTRACT

BACKGROUND: Inspite of having advanced treatment modalities the overall survival rate in oral squamous cell carcinoma (OSCC) remains poor. This is considered to be mainly due to local recurrence and distant metastasis. Various studies have concentrated on the role of oral cancer stem cells (OCSCs) in the progression and metastasis of OSCC. However, the role of tumor microenvironment components has been less delved into. Hence clarity on cell biology and metastatic potential OCSCs is essential for the development of more effective anti-cancer treatment.

AIM: To establish the role of OCSCs in different grades of OSCC and metastatic lymph nodes through the expression of cluster of differentiation 44 (CD44). To demonstrate and correlate the role of hypoxia and Epithelial mesenchymal transition (EMT) in the various grades and metastatic lymph nodes in the formation and maintenance of OCSCs by employing Hypoxia-inducible factor-1 Alpha (HIF 1α) and Snail respectively.

METHOD AND MATERIAL: A total of 36 cases of OSCC, 12 from each grade and 12 normal oral mucosal tissues were included in the study. Immunohistochemical staining was performed for the demonstration of CD44, HIF1α, and Snail.

STATISTICS: Descriptive analysis, Chi-square, and Spearman’s rank correlation were used to analyze frequency and proportion, to compare expression and correlate between lesion proper and lymph node in each group respectively.

RESULTS: Significant expression of CD44, HIF1 α, and Snail among advancing grades of OSCC and their metastatic lymph node were observed. A positive correlation was seen between them.

CONCLUSIONS: The prognosis of OSCC can be improved by better understanding and targeting the molecules involved in the formation and maintenance of OCSCs.

PMID:37854934 | PMC:PMC10581292 | DOI:10.4103/jomfp.jomfp_368_22

J Oral Maxillofac Pathol. 2023 Apr-Jun;27(2):295-301. doi: 10.4103/jomfp.jomfp_301_22. Epub 2023 Jul 13.

ABSTRACT

BACKGROUND: The purpose of this experimental study was to evaluate and compare the degree of expression of Wilm’s Tumor Gene-1 (WT-1), Syndecan (CD 138) and Snail in Ameloblastoma and odontogenic keratocyst (OKC) and to analyse their potential role in pathogenesis.

METHODS AND MATERIAL: Immunohistochemical analysis was performed to evaluate WT-1, Syndecan and Snail expression in Ameloblastoma (n = 20) and OKC (n = 20). Topographical immunoexpression pattern of Ameloblast-like cells, Stellate Reticulum-like cells in Ameloblastoma and basal layer as well as suprabasal layer of cells of OKC were also compared. The results obtained were subjected to ANOVA test and Tukey HSD test through SPSS software 20.0 for Microsoft Windows.

RESULTS: WT-1 and Snail overexpression was seen in both Ameloblastoma and OKCs. Syndecan, responsible for maintaining normal cellular morphology, cell-cell adhesion and differentiation was significantly downregulated in both the lesions. The Ameloblasts-like cells and the basal cells showed significantly higher immunopositivity for WT-1 and Syndecan as compared to that of basal cells. An inverse relation was noted for Snail protein. The ANOVA test predicted a statistically significant difference of expression across the lesions with a P value <0.0001 for Syndecan and Snail.

CONCLUSIONS: The under-expression of epithelial membrane protein Syndecan-1 and upregulation of EMT transcription factor Snail can promote local invasion and is indicative of poor prognosis of these lesions. The overexpression of WT-1 results in tumorigenesis, proliferation and localized aggressiveness of Ameloblastoma and intrabony growth of OKC. Further investigation on the biologic behaviour of OKC is still recommended to arrive at more specific conclusions regarding its nature.

PMID:37854929 | PMC:PMC10581317 | DOI:10.4103/jomfp.jomfp_301_22

J Oral Maxillofac Pathol. 2023 Apr-Jun;27(2):427. doi: 10.4103/jomfp.jomfp_198_22. Epub 2023 Jul 13.

ABSTRACT

AIM: This is a cross-sectional comparative study, aimed to quantify the expression of patched (PTCH) gene in ameloblastoma, odontogenic keratocyst (OKC) and also the comparison of both the expressions.

MATERIALS AND METHODS: Genomic deoxyribonucleic acid (DNA) was extracted and quantified, and the expression of the PTCH gene was done in 17 cases of ameloblastoma and 17 cases of OKC by quantitative real-time polymerase chain reaction (RT-qPCR).

RESULTS: It was observed that there was an overexpression of the PTCH gene in both ameloblastoma and OKC with a good mean cycle threshold (CT) value of 32.71 ± 2.432 and 34.69 ± 1.875, respectively. When comparing the PTCH expression between the two, ameloblastoma showed higher expression than the OKC and the difference is statistically significant with P value of 0.025.

CONCLUSIONS: Our findings suggest that there is overexpression of PTCH in ameloblastoma and OKC, but it is highly expressed in ameloblastoma when compared to OKC. Overexpression of PTCH may constitute the activation of the Sonic Hedgehog pathway and may suggest the mechanism for the development of ameloblastoma and OKC. Hence it can be used as a valuable marker for early diagnosis and in the identification of therapeutic targets.

PMID:37854928 | PMC:PMC10581290 | DOI:10.4103/jomfp.jomfp_198_22

J Oral Maxillofac Pathol. 2023 Apr-Jun;27(2):424. doi: 10.4103/jomfp.jomfp_146_22. Epub 2023 Jul 13.

ABSTRACT

BACKGROUND: Hematoxylin and eosin staining is the globally accepted staining technique for histology and histopathology sections. Hematoxylin is a natural dye as compared to eosin which is a synthetic dye manufactured from chemicals. Eosin acts as a counterstain to hematoxylin giving a sharp contrast to its blue color. Eosin being a chemical, can cause health hazards and environmental pollution. Using eco-friendly materials and going organic is the demand of this era. Curcuma longa rhizomes are proven to contain curcuminoids that exhibit various medicinal properties and curcumin the bright yellow component of the plant, that is, being used as a colorant. This natural dye from C. longa provides a significant alternative to eosin as they are safer to use without health hazards and are biodegradable and have easy disposability.

AIM: To evaluate and compare the staining qualities of C. longa (turmeric) with hematoxylin and eosin (H&E).

MATERIALS AND METHODS: A total of 100 paraffin-embedded tissue block specimens of various pathological tissues were stained with H and E and hematoxylin and curcumin (H&C). Evaluation and comparison of the staining efficacy were done for all the pathological tissues. The obtained data were subjected to statistical analysis.

RESULTS: H&C staining gave comparable results with H and E staining with a statistically insignificant P value (p > 0.05).

CONCLUSION: Curcumin has shown equivalent staining to that of eosin. Thus, it can be used as a better alternative.

PMID:37854923 | PMC:PMC10581282 | DOI:10.4103/jomfp.jomfp_146_22

J Oral Maxillofac Pathol. 2023 Apr-Jun;27(2):402-405. doi: 10.4103/jomfp.jomfp_205_22. Epub 2023 Jul 13.

ABSTRACT

INTRODUCTION: Age estimation using regressive alterations such as root dentin translucency, PDL attachment, and attrition are easy and reliable way of predicting the age. However, extensive and population-specific formula has not been generated. This attempt was to assess the correlation of these alterations with age and to generate a Linear regressive formula, specific to this population.

METHODS AND MATERIAL: Three alterations were assessed such as dental attrition, root dentin translucency, and periodontal attachment level from the extracted teeth. Dental attrition was measured using Johanson’s and Li and Ji criteria. PDL attachment level and root dentin translucency was measured using the Johanson method and the Lamendin method.

STATISTICAL ANALYSIS: SPSS software (Version 27), Pearson correlation test, and Linear regressive analysis were used.

RESULTS: Our results showed all three factors/parameters such as attrition, periodontal ligament, and translucency having a very good correlation with age and correlation coefficient r value ranging from 0.6 to 0.8. All the parameters were having statistically significant correlation with P value <0.005. Among them, root dentin translucency with Johanson G method showed excellent correlation with r = 0.83 followed by PDL attachment by Johanson G method with r = 0.702.

CONCLUSIONS: Regressive changes such as Dentin translucency, PDL attachment and attrition on Coastal Karnataka showed a very good correlation with age. Among them, Dentin translucency by Johanson G method had the best correlation with the a standard error of estimate (SEE). Results of our study indicates that all these parameters [Translucency, PDL attachment, and attrition] can be utilized in age estimation.

PMID:37854921 | PMC:PMC10581294 | DOI:10.4103/jomfp.jomfp_205_22

J Oral Maxillofac Pathol. 2023 Apr-Jun;27(2):426. doi: 10.4103/jomfp.jomfp_136_22. Epub 2023 Jul 13.

ABSTRACT

BACKGROUND: Pain and anxiety are the most reported negative effect of orthodontic treatment which can influence the quality of life and are responsible for the discontinuation of treatment. These unpleasant experiences raise the stress levels reflected by the increase in the concentration of salivary alpha-amylase and nitric oxide. These can be assessed through various subjective methods which have limited value as it depends on the patient’s honesty, assessing whether using objective methods are reliable.

OBJECTIVES: To assess pain and anxiety-induced stress levels using both physiological (Salivary alpha-amylase and Salivary nitric oxide) and psychological testing instruments (Visual analog scale and State Trait Anxiety Inventory Y6) during the initial phases of fixed orthodontic treatment.

MATERIALS AND METHODS: A total of 30 patients were included. Pain and anxiety instruments were applied and saliva samples were collected from patients before and after separator placement, before and 48 h after archwire insertion and 1 month after archwire insertion.

RESULTS: The mean values of alpha-amylase (235.3600), nitric oxide levels (2.060) and pain scores (7.8667) were higher 48 h after archwire insertion (T3) which are statistically significant, P = 0.00. Anxiety scores (57.7000) were high before separator placement (T0). No statistically significant correlation was found among pain and alpha-amylase, anxiety and nitric oxide levels.

CONCLUSION: Initial alignment phases of fixed orthodontic treatment affect patients’ anxiety and stress levels. The findings could be a result of the psychological stress due to procedures in the initial phases of the treatment.

PMID:37854920 | PMC:PMC10581320 | DOI:10.4103/jomfp.jomfp_136_22

J Oral Maxillofac Pathol. 2023 Apr-Jun;27(2):333-339. doi: 10.4103/jomfp.jomfp_157_23. Epub 2023 Jul 13.

ABSTRACT

AIM: The current study evaluates and compares the percentage distribution of different microorganisms according to their strains and occurrence among the three studied groups.

METHOD AND METHODOLOGY: Sample of 30 removable dental prosthesis wearing patients was selected: wearing either complete dentures or partial dentures and without any significant medical history or on prescription medication for the past 3-6 months. Samples were obtained in three subcategories based on the duration of prostheses worn by the patient. A sterile swab made up of cotton moistened with phosphate buffer saline (PBS) was scrubbed on the dental prosthesis at the fitting surfaces and the denture-bearing area of the oral cavity. Within two hours, the collected swab sample was infused in the sterile tube containing 1 ml of 0.84% PBS solution maintained at pH 7-7.2 and sent for microbiological analysis. The samples were then inoculated into different medias. Microbial growth was checked after incubating the culture plates for 48 h at 37°C. Microorganisms were recognized and counted by calibrated colony counter. Gram’s stain was used to stain the colony smear and biochemical tests such as coagulase, catalase, oxidase, sugar fermentation with acid and gas production (triple sugar iron), methyl red test, test for indole production, hydrogen sulphide (H₂S) production, citrate utilization, urease test, germ tube tests were performed.

STATISTICAL ANALYSIS: Descriptive statistics included calculation of means and standard deviation using multivariate analysis. All values were considered statistically significant for a value of P < 0.05.

RESULTS: Streptococcus species, Coagulase-negative staphylococcus, Staphylococcus aureus, Candida albicans and Klebsiella pneumoniae showed the maximum positive culture among the secluded microorganisms in all three groups.

CONCLUSION: A progressive increase in the microbial contamination was directly proportional to the duration of removable prosthesis usage.

PMID:37854919 | PMC:PMC10581316 | DOI:10.4103/jomfp.jomfp_157_23

Integr Zool. 2023 Oct 18. doi: 10.1111/1749-4877.12770. Online ahead of print.

ABSTRACT

The dynamics of populations of small mammals of Central Siberia was analyzed. The studies were carried out at the Yenisei ecological station “Mirnoye” of the A.N. Severtsov Institute of Ecology and Evolution, Russian Academy of Sciences. The time series analysis was performed by the wavelet transform using the statistical data processing language R. In the 20th century, the dynamics of the population of the community and some of its constituent species (Sorex araneus; S. caecutiens; S. isodon; S. tundrensis; S. minutus; Craseomys rufocanus; Clethrionomys rutilus; Microtus oeconomus; M. agrestis) were characterized by a 4-year periodicity. The type of dynamics changed to noncyclic by the nineties, but by 2022, four species (S. araneus, S. isodon, C. rutilus, and M. oeconomus) and the community as a whole showed a tendency toward recovery of population cycles. The remaining species were characterized by consistently low numbers with irregular low amplitude fluctuations.

PMID:37853517 | DOI:10.1111/1749-4877.12770

BMJ Open. 2023 Oct 18;13(10):e074700. doi: 10.1136/bmjopen-2023-074700.

ABSTRACT

INTRODUCTION: Despite technological advancements in recent years, glenoid component loosening remains a common complication after anatomical total shoulder arthroplasty (ATSA) and is one of the main causes of revision surgery. Increasing emphasis is placed on the prevention of glenoid component failure. Previous studies have successfully predicted range of motion, patient-reported outcomes and short-term complications after ATSA using machine learning methods, but an accurate predictive model for (glenoid component) revision is currently lacking. This study aims to use a large international database to accurately predict aseptic loosening of the glenoid component after ATSA using machine learning algorithms.

METHODS AND ANALYSIS: For this multicentre, retrospective study, individual patient data will be compiled from previously published studies reporting revision of ATSA. A systematic literature search will be performed in Medline (PubMed) identifying all studies reporting outcomes of ATSA. Authors will be contacted and invited to participate in the Machine Learning Consortium by sharing their anonymised databases. All databases reporting revisions after ATSA will be included, and individual patients with a follow-up less than 2 years or a fracture as the indication for ATSA will be excluded. First, features (predictive variables) will be identified using a random forest feature selection. The resulting features from the compiled database will be used to train various machine learning algorithms (stochastic gradient boosting, random forest, support vector machine, neural network and elastic-net penalised logistic regression). The developed and validated algorithms will be evaluated across discrimination (c-statistic), calibration, the Brier score and the decision curve analysis. The best-performing algorithm will be used to create an open-access online prediction tool.

ETHICS AND DISSEMINATION: Data will be collected adhering to the WHO regulation on data sharing. An Institutional Review Board review is not applicable. The study results will be published in a peer-reviewed journal.

PMID:37852772 | DOI:10.1136/bmjopen-2023-074700