CDYL1-dependent decrease in lysine crotonylation at DNA double-strand break sites functionally uncouples transcriptional silencing and repair.

Previously, we showed that CDYL1 is recruited to DNA double-strand breaks (DSBs) to promote homologous recombination (HR) repair and foster transcriptional silencing. However, how CDYL1 elicits DSB-induced silencing is not fully understood. Here, we identify a CDYL1-dependent local decrease in the transcriptionally active marks histone lysine crotonylation (Kcr) and crotonylated lysine 9 of H3 (H3K9cr) at AsiSI-induced DSBs, which correlates with transcriptional silencing. Mechanistically, we reveal that CDYL1 crotonyl-CoA hydratase activity counteracts Kcr and H3K9cr at DSB sites, which triggers the eviction of the transcription elongation factor ENL and fosters transcriptional silencing. Furthermore, genetic inhibition of CDYL1 hydratase activity blocks the reduction in H3K9cr and alleviates DSB-induced silencing, whereas HR efficiency unexpectedly remains intact. Therefore, our results functionally uncouple the repair and silencing activity of CDYL1 at DSBs. In a broader context, we address a long-standing question concerning the functional relationship between HR repair and DSB-induced silencing, suggesting that they may occur independently.

Drunkenness and Regretted Online Social Risk Behaviors: The Role of Social Drinking Motives and Positive Urgency.

Background: Alcohol use and the use of social media and other forms of digital communications is characteristic of young adults. The present study prospectively examined the relationship between social drinking motives and positive urgency and the engagement in regretted online social risk behaviors while drunk (having posted on social media, called or texted someone, or been visibly drunk in a photo) among a community sample of young adults. Methods: Using a targeted sampling procedure, we accessed a baseline sample of 360 young adults aged 18-25 years old from the community. Of these, 339 (mean age: 21.1 [SD = 2.21]; female = 50.7%) completed 2-month follow-up measures. Results: Social drinking motives and the tendency to act impulsively under conditions of positive affect (i.e. positive urgency) were measured at baseline, and frequency of regretted online social risk behaviors were measured at follow-up. Results showed that baseline social drinking motives were positively associated with all three regretted online social risk behaviors examined at follow-up. Higher baseline positive urgency scores were associated with a higher frequency of regretted posting on social media and calling or texting someone while drunk at follow-up. Conclusions: Our findings support the inclusion of positive urgency and social drinking motives as key components of preventive interventions aimed at reducing potential negative consequences of using social media and other forms of digital communications while under the effects of alcohol.

Manufacturing an active X-ray mirror prototype in thin glass.

Adjustable mirrors equipped with piezo actuators are commonly used at synchrotron and free-electron laser (FEL) beamlines, in order to optimize their focusing properties and sometimes to shape the intensity distribution of the focal spot with the desired profile. Unlike them, X-ray mirrors for astronomy are much thinner in order to enable nesting and reduce the areal mass, and the application of piezo actuators acting normally to the surface appears much more difficult. There remains the possibility to correct the deformations using thin patches that exert a tangential strain on the rear side of the mirror: some research groups are already at work on this approach. The technique reported here relies on actively integrating thin glass foils with commercial piezoceramic patches, fed by voltages driven by the feedback provided by X-rays, while the tension signals are carried by electrodes on the back of the mirror, obtained by photolithography. Finally, the shape detection and the consequent voltage signal to be provided to the piezoelectric array will be determined by X-ray illumination in an intra-focal setup at the XACT facility. In this work, the manufacturing steps for obtaining a first active mirror prototype are described.

WITHDRAWN: PET-CT derived Artificial Neural Network can predict mediastinal lymph nodes metastases in Non-Small Cell Lung Cancer patients. Preliminary report and scoring model.

Ahead of Print article withdrawn by publisher.

Respiratory complications associated with ketamine anesthesia for ophthalmic procedures following intraocular pressure measurement in children.

BACKGROUND: We compared respiratory complications (RCs) in children who received intramuscular (IM) versus intravenous (IV) or no ketamine for intraocular pressure (IOP) measurement to test our observation that IM ketamine is associated with higher incidence of RCs. MATERIALS AND METHODS: We analyzed 149 eye examinations under anesthesia with ketamine in 27 patients and 263 non-ketamine examinations under anesthesia in 81 patients using a mixed effects logistic regression model. RESULTS: IM KETAMINE WAS STRONGLY ASSOCIATED WITH INCREASED ODDS OF RCS COMPARED TO NO KETAMINE (ODDS RATIO (OR): 20.23, P < 0.0001) and to IV ketamine (OR: 6.78, P = 0.02), as were higher American Society of Anesthesiologists (ASA) classification (OR: 2.60, P = 0.04), and the use of volatile agents (OR: 3.32, P = 0.02). CONCLUSION: Further studies should be conducted to confirm our observation of increased RCs with IM ketamine.

Awareness and attitude of ENT surgeons towards various dental implants or oral surgery procedures: a cross-sectional survey in the UK.

OBJECTIVE: To assess the level of awareness and attitude of ENT surgeons towards dental implants and oral surgery procedures that involve the maxillary sinus. METHODS: A cross-sectional survey was conducted using a closed-ended questionnaire on 40 UK-based ENT surgeons. RESULTS: Within the study population, 45 per cent of ENT surgeons were not aware of sinus lift augmentation in implant dentistry. Only 25 per cent of respondents were aware of the two subtypes of sinus lift techniques. Thirty per cent of the respondents were aware of or had heard of benign positional paroxysmal vertigo following dental treatment. Fifty-two per cent of respondents came across a dental foreign body, most commonly a tooth that had been displaced into the maxillary sinus. It was also reported that 82.5 per cent of respondents had liaised with an oral surgeon for an oroantral communication problem or a dental infection. CONCLUSION: Dental awareness among ENT surgeons needs to be raised for optimum interdisciplinary communication and patient safety.

A dual role of RBM42 in modulating splicing and translation of CDKN1A/p21 during DNA damage response.

p53-mediated cell cycle arrest during DNA damage is dependent on the induction of p21 protein, encoded by the CDKN1A gene. p21 inhibits cyclin-dependent kinases required for cell cycle progression to guarantee accurate repair of DNA lesions. Hence, fine-tuning of p21 levels is crucial to preserve genomic stability. Currently, the multilayered regulation of p21 levels during DNA damage is not fully understood. Herein, we identify the human RNA binding motif protein 42 (RBM42) as a regulator of p21 levels during DNA damage. Genome-wide transcriptome and interactome analysis reveals that RBM42 alters the expression of p53-regulated genes during DNA damage. Specifically, we demonstrate that RBM42 facilitates CDKN1A splicing by counteracting the splicing inhibitory effect of RBM4 protein. Unexpectedly, we also show that RBM42, underpins translation of various splicing targets, including CDKN1A. Concordantly, transcriptome-wide mapping of RBM42-RNA interactions using eCLIP further substantiates the dual function of RBM42 in regulating splicing and translation of its target genes, including CDKN1A. Collectively, our data show that RBM42 couples splicing and translation machineries to fine-tune gene expression during DNA damage response.

Limitations of conventional approaches to identify photochemically produced reactive intermediates involved in contaminant indirect photodegradation.

Dissolved organic matter (DOM) mediated indirect photodegradation can play an important role in the degradation of aquatic contaminants. Predicting the rate of this process requires knowledge of the photochemically produced reactive intermediates (PPRI) that react with the compound of interest, as well as the ability of individual DOM samples to produce PPRI. Key PPRI are typically identified using quencher studies, yet this approach often leads to results that are difficult to interpret. In this work, we analyze the indirect photodegradation of atorvastatin, carbamazepine, sulfadiazine, and benzotriazole using a diverse set of 48 waters from natural and engineered aquatic systems. We use this large data set to evaluate relationships between PPRI formation and indirect photodegradation rate constants, which are directly compared to results using standard quenching experiments. These data demonstrate that triplet state DOM (3DOM) and singlet oxygen (1O2) are critical PPRI for atorvastatin, carbamazepine, and sulfadiazine, while hydroxyl radical (˙OH) contributes to the indirect photodegradation of benzotriazole. We caution against relying on quenching studies because quenching of 3DOM limits the formation of 1O2 and all studied quenchers react with ˙OH. Furthermore, we show that DOM composition directly influences indirect photodegradation and that low molecular weight, microbial-like DOM is positively correlated with the indirect photodegradation rates of carbamazepine, sulfadiazine, and benzotriazole.

Retention in treatment and therapeutic adherence: How are these associated with therapeutic success? An analysis using real-world data.

INTRODUCTION: Treatment retention and adherence are used as outcomes in numerous randomized clinical trials and observational studies conducted in the addiction field. Although usual criteria are 3/6 months of treatment retention or number of sessions attended, there is not a methodological support for conclusions using these criteria. This study analyzed the usefulness of retention and adherence to predict therapeutic success. METHODS: Retrospective observational study using real-world data from electronic health records of 11,907 patients in treatment diagnosed with cocaine, alcohol, cannabis and opiate use disorders or harmful use. RESULTS: Moderate effect size relations were found between the different type of clinical discharge and months in retention (η2  = 0.12) and proportion of attendance (η2  = 0.10). No relationship was found with the number of sessions attended. Using cut-off points (i.e., 3 or 6 months in treatment or attending 6 therapy sessions) worsens the ability to predict the type of discharge. DISCUSSIONS/CONCLUSION: Treatment retention and adherence are indicators moderately related to therapeutic success. Research using these indicators to assess the effectiveness of therapies should complement their results with other clinical indicators and quality of life measures.

A longitudinal study among young adults into the predictive effect of perceived efficacy of behavioural strategies and the moderating role of drinking motives on use of protective behavioural strategies.

INTRODUCTION: Although protective behavioural strategies (PBS) have shown to be effective in minimising alcohol-related negative consequences, research on the explanatory factors of their use is very scarce. Perceived efficacy has been demonstrated to be one of the most relevant explanatory factors in the use of health-related protective behaviours. The present study prospectively examines the relationship between the perceived efficacy of PBS in reducing alcohol-related negative consequences and the use of PBS in a community-based sample of young adults. In addition, the moderating role of drinking motives in this relationship is also examined. METHODS: Prospective design with a baseline assessment and a 2-month follow up. Using a targeted sampling procedure, 339 young adults were recruited from the community [mean age: 21.1 (SD = 2.21); female = 50.7%] and completed questionnaires to measure perceived efficacy of PBS and drinking motives at baseline and PBS use at follow up. RESULTS: Perceived efficacy of PBS at baseline was positively associated with PBS use at follow up, and these relationships were weaker as social, enhancement and coping motives scores increased. DISCUSSION AND CONCLUSIONS: Our findings support the need to include the perceived efficacy of PBS to reduce alcohol-related negative consequences in future interventions aimed at promoting PBS use. Moreover, these interventions should be personalised according to the initial levels of participants' drinking motives, incorporating elements that allow for neutralising their negative effects on PBS use (e.g. training in coping skills for those with strong coping motives).

Harm Reduction Strategies among University Students Who Use Alcohol and Cannabis, and Related Psychological Variables: A Systematic Review.

This systematic review identifies the psychological variables associated with the use of harm reduction strategies (HRS) among university students who use alcohol or cannabis. The reviewed studies are categorized according to the psychological variables studied and the different analytic approaches used (direct effects, mediation, and moderation). Among the empirical peer-reviewed studies identified (n = 76), most (94.7%) were cross-sectional studies conducted in the US (90.8%) with samples of alcohol-using university students (86.8%). Five categories were identified: mental health, motives/expectancies, personality, social cognition, and self-efficacy. The most studied constructs were motives, anxiety and depression, impulsivity, and social norms. Most studies conducted mediation or moderation analyses including psychological variables, HRS and alcohol outcomes. Social, enhancement and coping motives, impulsivity, and social norms of alcohol use were associated with lower use of HRS, which, in turn, was associated with a higher number of alcohol/cannabis outcomes. The results of moderation studies consistently suggest that HRS use was more protective for students with poor mental health, high impulsivity, and low self-regulation. The synthesis of evidence provided in this review could be useful for guiding future research and informing the design of interventions aimed at promoting the use of HRS among university students who use alcohol and/or cannabis.

Major histocompatibility complex Class II-based therapy for stroke.

This review discusses the potential of major histocompatibility complex (MHC) Class II constructs as stroke therapeutics. We focus on the delivery of MHC Class II construct, DRmQ, as a safe and effective treatment for ischemic stroke. DRmQ was observed to attenuate behavioral deficits and decrease microglia activation and proinflammatory cytokines, illustrating its ability to mitigate the secondary cell death following stroke. Similar anti-neuroinflammation treatments, such as transplantation of mesenchymal stem cells and mitochondrial transfers, are briefly discussed to provide further support that sequestration of inflammation stands as a robust therapeutic target for stroke.

Predictive Utility of Protective Behavioral Strategies for Alcohol-Related Outcomes in a Community Sample of Young Adults.

OBJECTIVE: Although previous studies have shown that protective behavioral strategies (PBS) predict alcohol use and its related consequences in college students, it is not known whether a broader population of young adults also benefit from PBS use. We longitudinally examined the relationship between PBS use and alcohol-related outcomes in a community sample of young adults composed of college students and noncollege individuals. METHOD: Targeted sampling was used to access 339 young adults in the community (mean age = 21.1 [SD = 2.21], 50.7% female; 59.0% college students) who completed baseline and 2-month follow-up measures. Three types of PBS were examined: manner of drinking, stopping/limiting drinking, and serious harm reduction. Regression analyses were conducted to test the predictive utility of PBS use on alcohol-related consequences, frequency and quantity of alcohol used, and binge drinking. RESULTS: Manner of drinking strategies were the strongest predictors of decreased alcohol consumption and alcohol-related negative consequences. Baseline manner of drinking scores were negatively associated with quantity of alcohol used, binge drinking, and alcohol-related consequences at follow-up. Serious harm reduction was longitudinally related to a lower frequency of alcohol consumption, stopping/limiting drinking was not associated with any outcome, and total PBS score was associated with all study outcomes. CONCLUSIONS: Our findings could benefit health promotion by informing the design of preventive interventions for reducing alcohol use and attendant health-related negative consequences in the young adult community. These results may also be of value in extending the applicability of PBS findings to a broader alcohol-using population of young adults beyond those exclusively composed of college students.

Profiles of patients with cocaine and alcohol use disorder based on cognitive domains and their relationship with relapse.

BACKGROUND: Relapse in drug use constitutes a research topic on addiction that is relevant for understanding both the addictive process and its clinical implications. The objective of this study was to explore if it is possible to identify patient profiles according to their performance on cognitive tasks whilst examining the relationship between such profiles and relapse. METHODS: The sample consisted of 222 patients with dependence on cocaine and / or alcohol, of which 86 % were men. Cognitive domains related to salience, decision- making, and emotional processing were measured. RESULTS: Latent class analysis revealed three patient profiles that differ in terms of performance on cognitive tasks. Two of these profiles are clearly differentiated in terms of their execution of the impulsive decision-making task. The third patient profile, unlike the latter two, is composed of patients with severe alterations in the three domains evaluated. Analysis revealed that patients in Profile 3 are those with the highest rates of relapse in cocaine (Profile 1 = 40.3 %; Profile 2 = 35.6 %; Profile 3 = 69.2 %; Chi2 = 9.169; p < .05) and cocaine and alcohol use (Profile 1 = 55.1 %; Profile 2 = 54.1 %; Profile 3 = 80 %; Chi2 = 6.698; p < .05). CONCLUSIONS: The results support the postulates of the I-RISA model. From a clinical perspective, these findings highlight the need for a comprehensive evaluation of the cognitive domains involved in addiction.

Primate-specific stress-induced transcription factor POU2F1Z protects human neuronal cells from stress.

The emergence of new primate-specific genes is an essential factor in human and primate brain development and functioning. POU2F1/Oct-1 is a transcription regulator in higher eukaryotes which is involved in the regulation of development, differentiation, stress response, and other processes. We have demonstrated that the Tigger2 transposon insertion into the POU2F1 gene which occurred in the primate lineage led to the formation of an additional exon (designated the Z-exon). Z-exon-containing primate-specific Oct-1Z transcript includes a short upstream ORF (uORF) located at its 5'-end and the main ORF encoding the Oct-1Z protein isoform (Pou2F1 isoform 3, P14859-3), which differs from other Oct-1 isoforms by its N-terminal peptide. The Oct-1Z-encoding transcript is expressed mainly in human brain cortex. Under normal conditions, the translation of the ORF coding for the Oct-1Z isoform is repressed by uORF. Under various stress conditions, uORF enables a strong increase in the translation of the Oct-1Z-encoding ORF. Increased Oct-1Z expression levels in differentiating human neuroblasts activate genes controlling stress response, neural cell differentiation, brain formation, and organogenesis. We have shown that the Oct-1Z isoform of the POU2F1/Oct-1 transcription factor is an example of a primate-specific genomic element contributing to brain development and cellular stress defense.

Natural Radioactivity of the Crystalline Basement Rocks of the Peloritani Mountains (North-Eastern Sicily, Italy): Measurements and Radiological Hazard.

Crystalline rocks can produce dangerous radiation levels on the basis of their content in radioisotopes. Here, we report radiological data from 10 metamorphic and igneous rock samples collected from the crystalline basement of the Peloritani Mountains (southern Italy). In order to evaluate the radiological properties of these rocks, the gamma radiation and the radon emanation have been measured. Moreover, since some of these rocks are employed as building materials, we assess the potential hazard for population connected to their use. Gamma spectroscopy was used to measure the 226Ra, 232Th and 40K activity concentration, whereas the radon emanation was investigated by using a RAD 7 detector. The results show 226Ra, 232Th and 40K activity concentration values ranging from (17 ± 4) to (56 ± 8) Bq kg-1, (14 ± 3) to (77 ± 14) Bq kg-1 and (167 ± 84) to (1760 ± 242) Bq kg-1, respectively. Values of the annual effective dose equivalent outdoor range from 0.035 to 0.152 mSv y-1, whereas the gamma index is in the range of 0.22-0.98. The 222Rn emanation coefficient and the 222Rn surface exhalation rate vary from (0.63 ± 0.3) to (8.27 ± 1.6)% and from (0.12 ± 0.03) to (2.75 ± 0.17) Bq m-2 h-1, respectively. The indoor radon derived from the building use of these rocks induces an approximate contribution to the annual effective dose ranging from 8 to 176 µSv y-1. All the obtained results suggest that the crystalline rocks from the Peloritani Mountains are not harmful for the residential population, even though they induce annual effective doses due to terrestrial gamma radiation above the worldwide average values. Moreover, their use as building materials does not produce significant health hazards connected to the indoor radon exposure.

Extracellular PBEF/NAMPT/visfatin activates pro-inflammatory signalling in human vascular smooth muscle cells through nicotinamide phosphoribosyltransferase activity.

AIMS/HYPOTHESIS: Extracellular pre-B cell colony-enhancing factor/nicotinamide phosphoribosyltransferase/visfatin (ePBEF/NAMPT/visfatin) is an adipocytokine, whose circulating levels are enhanced in metabolic disorders, such as diabetes mellitus and obesity. Here, we explored the ability of ePBEF/NAMPT/visfatin to promote vascular inflammation, as a condition closely related to atherothrombotic diseases. We specifically studied the ability of PBEF/NAMPT/visfatin to directly activate pathways leading to inducible nitric oxide synthase (iNOS) induction in cultured human aortic smooth muscle cells, as well as the mechanisms involved. METHODS: iNOS levels and extracellular signal-regulated kinase (ERK) 1/2 activity were determined by western blotting. Nuclear factor (NF)-kappaB activity was assessed by electrophoretic mobility shift assay. RESULTS: ePBEF/NAMPT/visfatin (10-250 ng/ml) induced iNOS in a concentration-dependent manner. At a submaximal concentration (100 ng/ml), ePBEF/NAMPT/visfatin time-dependently enhanced iNOS levels up to 18 h after stimulation. Over this time period, ePBEF/NAMPT/visfatin elicited a sustained activation of NF-kappaB and triggered a biphasic ERK 1/2 activation. By using the respective ERK 1/2 and NF-kappaB inhibitors, PD98059 and pyrrolidine dithiocarbamate, we established that iNOS induction by ePBEF/NAMPT/visfatin required the consecutive upstream activation of ERK 1/2 and NF-kappaB. The pro-inflammatory action of ePBEF/NAMPT/visfatin was not prevented by insulin receptor blockade. However, exogenous nicotinamide mononucleotide, the product of NAMPT activity, mimicked NF-kappaB activation and iNOS induction by ePBEF/NAMPT/visfatin, while the NAMPT inhibitor APO866 prevented the effects of ePBEF/NAMPT/visfatin on iNOS and NF-kappaB. CONCLUSIONS/INTERPRETATION: Through its intrinsic NAMPT activity, ePBEF/NAMPT/visfatin appears to be a direct contributor to vascular inflammation, a key feature of atherothrombotic diseases linked to metabolic disorders.

Lipid and colour stability of meat from lambs fed fresh herbage or concentrate.

Fourteen male Comisana lambs were divided into two groups at 45days of age and were individually penned for 105days. Over this period, seven lambs were fed a concentrate-based diet (C), whereas the remaining animals received vetch (Vicia sativa; H) harvested daily and given fresh to the animals. Lipid oxidation was measured in both minced cooked meat (semimembranosus muscle, SM) over 4days of aerobic refrigerated storage and on minced raw meat stored over 14days in a high oxygen atmosphere. Colour descriptors, haem pigment concentration, and metmyoglobin percentages were also determined during storage duration on the minced raw meat. Lipid oxidation increased over time in cooked and raw meat (P<0.0005), but lower TBARS values were found in both cooked and minced meat from lambs fed vetch compared to those given concentrates (P=0.001; P=0.006, respectively). Higher a* values, lower b* values and lower hue angle values were observed in meat from H-fed animals as compared to meat from C-fed lambs (P=0.006; P=0.02; P=0.005, respectively). Metmyoglobin formation increased over time (P<0.0005), but the H diet resulted in lower metmyoglobin percentages than the C diet (P=0.006). Haem pigment concentration decreased over the 14days of storage (P<0.0005). We conclude that, under conditions that promote oxidative stress in meat, a herbage-based diet can improve the oxidative stability of meat compared to a concentrate-based diet.

Prospective evaluation of liver fibrosis in chronic viral hepatitis C infection using the Sabadell NIHCED (Non-Invasive Hepatitis-C-Related Cirrhosis Early Detection) index.

INTRODUCTION: liver disease resulting from chronic hepatitis C virus (HCV) infection follows an asymptomatic course towards cirrhosis and its complications in 20-40% of cases. Earlier studies demonstrated that advanced fibrosis is a prognostic factor. The "gold standard" for the evaluation of fibrosis grade is liver biopsy. Our group validated a predictive index - NIHCED - based on demographic, laboratory parameters, and echographic data to determine the presence of cirrhosis. OBJECTIVE: our objective is to evaluate whether the NIHCED score predicts the presence of advanced fibrosis in patients with chronic HCV infection. MATERIAL AND METHODS: this prospective study included patients with chronic HCV infection who underwent liver biopsy and were administered the NIHCED score. Fibrosis grade correlated with the NIHCED score using the ROC curve analysis and Spearman s correlation coefficient. RESULTS: in total 321 patients were included (male/female ratio 1.27) with a mean age of 48 +/- 14 years. Liver biopsy showed that 131 (30.5%) had no fibrosis or had portal expansion while 190 (69.5%) had advanced fibrosis or cirrhosis. At a cut-off point of 6, sensitivity was 72%, specificity was 76.3%, positive predictive value (PPV) was 81%, negative predictive value (NPV) was 63.7%, and diagnostic accuracy was 72.5%, with an area under the curve (AUC) of 0.787, and a Spearman s correlation coefficient of r = 0.65. CONCLUSIONS: the NIHCED score predicts the presence of advanced fibrosis in an elevated percentage of patients with a need of liver biopsy.

Search for histopathological characteristics of inflammatory juvenile conjunctival nevus in conjunctival nevi related to age: Analysis of 33 cases.

PURPOSE: Conjunctival nevi in young individuals can correspond to the entity named Inflammatory Juvenile Conjunctival Nevus (IJCN), presenting clinically as a rapid growth lesion, and showing at the histopathological study an inflammatory infiltrate surrounding the lesion. All these findings can suggest a diagnosis of malignancy. Due to a case of IJCN diagnosed in our Pathology department, we realized that this entity is rarely reported in the literature and histopathological diagnostic criteria are not well defined. The aim of our study is to compare the histopathological characteristics of conjunctival nevi in patients aged thirty years or less to those in patients above 30 years, looking for the findings described in IJCN. METHODS: All the excisional specimens of resected conjunctival nevus in a tertiary hospital from 2000 to 2018 were retrieved from the Pathology department archives. Demographic data were recorded, and histopathological variables (histological type of nevus, lymphocytic infiltration, eosinophilic infiltration, presence of lymphoid follicles, stromal nevomelanocytic component, intraepithelial nevomelanocytic component, epithelial inclusions, quantity of goblet cells in epithelial inclusions, cellular atypia, mitoses and maturation of the lesion) were evaluated by three independent observers. Statistical analysis was performed comparing the two age groups. RESULTS: The study determined a significant predominance of the lymphocytic and eosinophilic infiltration in the group of patients aged thirty years or less respect to the elderly group. The percentage of stromal component of the lesion is larger in patients over thirty years compared to the younger group. There was no correlation between epithelial inclusions, maturation or cytological atypia and age groups. CONCLUSION: We found some histopathological differences in conjunctival nevi related to young age, some of them coincident with the ones described in IJCN, which histopathologically could lead to a misleading diagnosis. However, we did not find significant differences related to age in many of the described histopathological findings described in IJCN. Larger series with a greater number of cases would be of interest to characterize more precisely this lesion.