Life-course socio-economic status and its impact on functional health of Portuguese older adults.

Functional health is arguably one of the most important health indicators for older adults, because it assesses physical, cognitive and social functions in combination. However, life-course circumstances may impact this multidimensional construct. The aim of the present study was to assess the relationship between life-course socio-economic status (SES) and different dimensions of functional health in older adults. Data on 821 Portuguese adults aged 50 years and over in 2013-2015 were analysed. Life-course SES was computed using participants' paternal occupation (non-manual (nm); manual (m)) and own occupation (nm; m), resulting in four patterns: stable high (nm + nm), upward (m + nm), downward (nm + m) and stable low (m + m). Functional health included physical and mental functioning, cognitive function, handgrip strength, and walking speed. Linear (beta coefficients) and logistic regressions (odds ratios) were used to estimate the association between life-course SES and functional health.Overall, those who accumulated social disadvantage during life-course presented worse functional health than those with stable high SES (stable low - SF-36 physical functioning: ß = -9.75; 95% CI: -14.34; -5.15; SF-36 mental health: ß = -7.33; 95% CI: -11.55; -3.11; handgrip strength: ß = -1.60; 95% CI: -2.86; -0.35; walking time, highest tertile: OR = 5.28; 95% CI: 3.07; 9.09). Those with an upward SES were not statistically different from those in the stable high SES for most of the health outcomes; however, those with an upward SES trajectory tended to have higher odds of cognitive impairment (OR = 1.75; 95% CI: 0.96; 3.19). A downward SES trajectory increased the odds of slower walking speed (OR = 4.62; 95% CI: 1.78; 11.95). A disadvantaged life-course SES impacts older adults' physical and mental functioning. For some outcomes, this was attenuated by a favourable adulthood SES but those with a stable low SES consistently presented worse functional health.

Gingival neoplasms: a multicenter collaborative study of 888 patients in Brazil.

BACKGROUND: To evaluate the prevalence and clinicopathological features of a large series of gingival neoplasms in Brazil. MATERIAL AND METHODS:  All gingival benign and malignant neoplasms were retrieved from the records of six Oral Pathology Services in Brazil, during a 41-year period. Clinical and demographic data, clinical diagnosis, and histopathological data were collected from the patients' clinical charts. For statistical analysis, the chi-square, median test of independent samples and the U Mann-Whitney tests were used, considering a significance of 5%. RESULTS:  From 100,026 oral lesions, 888 (0.9%) were gingival neoplasms. There were 496 (55.9%) males, with a mean age of 54.2 years. Most cases (70.3%) were malignant neoplasms. Nodules (46.2%) and ulcers (38.9%) were the most common clinical appearance for benign and malignant neoplasms, respectively. Squamous cell carcinoma (55.6%) was the most common gingival neoplasm, followed by squamous cell papilloma (19.6%). In 69 (11.1%) malignant neoplasms, the lesions were clinically considered to be inflammatory or of infectious origin. Malignant neoplasms were more common in older men, appeared with larger size, and with a time of complaint shorter than benign neoplasms (p<0.001). CONCLUSIONS:  Benign and malignant tumors may appear as nodules in gingival tissue. In addition, malignant neoplasms, especially squamous cell carcinoma, should be considered in the differential diagnosis of persistent single gingival ulcers.

Abuse among Portuguese older people at a time of economic crisis recovery: findings from the Harmed study.

This study aimed to assess the prevalence of abuse against Portuguese older people after an economic crisis and to assess how it has influenced health. A cross-sectional study was carried out including 677 older adults (≥60 years) during 2017. Results show that overall, 23.9% of older people reported being a victim of abuse in the last 12 months. The prevalence of psychological abuse was 19.9%, financial abuse 5.8%, physical abuse 2.5% and sexual abuse 1.9%. Older people who report abuse were more likely to have perceived insufficient income and low social support. The abuse was also significantly associated with poor health status and depressive symptoms. Even in an auspicious period, more than a fifth of older people experiences abuse which is associated with social and health vulnerabilities. These results support that an investment should be made in terms of policies toward an age-friendly environment.

Developing a social prescribing local system in a European Mediterranean country: a feasibility study to promote active and healthy aging.

BACKGROUND: Social Prescribing (SP) is an innovative strategy to respond to the non-clinical health needs of the population. A Social Prescribing Local System (SPLS) can be defined as a set of joined community, health, and social organizations to foster SP-oriented activities. This study aimed to develop and assess the feasibility of an SPLS implemented in a Mediterranean country, to promote health and wellbeing and contribute to active and healthy aging. METHODS: A mixed-methods approach was followed, including three sequential components: 1) Cross-sectional online survey targeting health professionals (HP) working in a primary health care cluster, Portugal's southern region; 2) Pilot study implementing an on-the-job training program for HP, designed to meet identified training needs in the survey; 3) Focus group (FG) with the HP who participated in the pilot study, two individual interviews, with an elderly patient and a community provider for assessing the satisfaction with the pilot test. RESULTS: Sixty-five HP completed the survey; of these, 13 completed the theoretical part of the on-the-job training program; and six (out of these 13) completed the full program. Five HP participated in the FG, one patient and one community provider were interviewed. The surveyed HP perceived as facilitators to implement SP: an automatic system of notifications to prompt the use of SP, contribute to patient satisfaction, human and community resources' stability. The survey also highlighted barriers to SP implementation: length of appointments, shortage of human resources, data records confidentiality, low patient adherence rates, bureaucratic issues, time constraints, and financial costs. Participants were satisfied with the training. Identified SPLS implementation benefits were grouped into four dimensions (from the qualitative approach): gains for patients' health and wellbeing, support for the health services, sustainability of the community resources, and HP' professional satisfaction. CONCLUSIONS: Our study took the first steps towards the implementation of an SPLS. Findings reinforce that training HP in SP and on-the-job training seems feasible. This approach was well received and appears to represent a suitable and sustainable strategy. It can promote professional satisfaction, support health services, contribute to the stability of community resources, improve health and promote active and healthy aging.

Simultaneous Determination of Neutron-Induced Fission and Radiative Capture Cross Sections from Decay Probabilities Obtained with a Surrogate Reaction.

Reliable neutron-induced-reaction cross sections of unstable nuclei are essential for nuclear astrophysics and applications but their direct measurement is often impossible. The surrogate-reaction method is one of the most promising alternatives to access these cross sections. In this work, we successfully applied the surrogate-reaction method to infer for the first time both the neutron-induced fission and radiative capture cross sections of ^{239}Pu in a consistent manner from a single measurement. This was achieved by combining simultaneously measured fission and γ-emission probabilities for the ^{240}Pu(^{4}He,^{4}He^{'}) surrogate reaction with a calculation of the angular-momentum and parity distributions populated in this reaction. While other experiments measure the probabilities for some selected γ-ray transitions, we measure the γ-emission probability. This enlarges the applicability of the surrogate-reaction method.

Socioeconomic position and quality of life among older people: The mediating role of social support.

Social support can obscure social gradients in health, but its role as a mediator between socioeconomic position (SEP) and quality of life (QoL) in older populations remains unknown. We aimed to examine to what extent social support mediates the association between SEP and overall QoL among older adults (aged 60-84 years). We studied a population-based cohort of 585 noninstitutionalized adults in Porto, Portugal, who were evaluated in 2009. Education, occupation, and perceived income adequacy were used as SEP indicators. The WHOQOL-OLD was used to determine overall QoL. Social support was assessed using the Multidimensional Scale of Perceived Social Support. Path analysis was conducted to quantify direct, indirect, and total effects of SEP on QoL. There was a positive total effect of education on QoL (ß = 0.28; 95% CI: 0.05-0.48). In this model, we found an indirect effect through social support (ß = 0.15; 95% CI: 0.05-0.26), explaining 54% of the pathway between education and QoL. A similar pattern was identified for the association between occupation and QoL. Perceived income adequacy had a total effect of 2.74 (95% CI: 1.68-3.93) on QoL. Although an indirect effect through social support was found (ß = 0.98; 95% CI: 0.42-1.55), a direct effect from this variable remained (ß = 1.76; 95% CI: 0.65-2.90). Social support can be a mechanism through which SEP impacts the QoL of older people. Strengthening social support ties may attenuate the impact of social inequalities and improve the QoL of this population.

Obesity-related knowledge and body mass index: a national survey in Portugal.

PURPOSE: Obesity-related knowledge predicts weight control but previous studies only comprise individuals with excessive weight and assess very specific aspects of knowledge. This study aims to evaluate several domains of obesity-related knowledge according to the body mass index (BMI) in a representative sample of Portuguese-speaking dwellers in mainland Portugal. METHODS: A sample of 1624 participants aged 16-79 years was analyzed. Eighteen questions comprising eight obesity domains were asked: prevalence, physical activity, number of calories, adiposity location, causes, diagnosis, treatment and consequences; each one was dichotomized into correct/incorrect knowledge. RESULTS: The majority of Portuguese-speaking dwellers recognized the benefits of physical activity, the risks of abdominal obesity and most consequences of excessive weight, independently of their BMI. However, knowledge gaps were identified regarding prevalence, calories and BMI diagnosis. BMI influenced specific obesity-related knowledge: participants with a normal BMI knew the BMI formula more often, identified 22 as normal BMI more frequently and had the highest proportion of correct knowledge regarding the number of calories an adult should eat; obese individuals identified natural products as not being good treatments for obesity more often. After adjusting for age, sex and educational level, obese individuals identified natural products and supplements as not being good obesity treatments more often. CONCLUSIONS: Obesity-related knowledge gaps (prevalence, calories, and diagnosis) were identified among Portuguese adults. Moreover, correct knowledge does not necessarily translate into a healthier BMI. Besides the dissemination of accurate information, public health interventions should focus on the transfer of knowledge to behaviors that will guarantee better weight management. EVIDENCE-BASED MEDICINE RANKINGS: Level V: Opinions of respected authorities, based on descriptive studies, narrative reviews, clinical experience, or reports of expert committees.

First Direct Measurement of Isotopic Fission-Fragment Yields of

A direct and complete measurement of isotopic fission-fragment yields of ^{239}U has been performed for the first time. The ^{239}U fissioning system was produced with an average excitation energy of 8.3 MeV in one-neutron transfer reactions between a ^{238}U beam and a ^{9}Be target at Coulomb barrier energies. The fission fragments were detected and isotopically identified using the VAMOS++ spectrometer at the GANIL facility. The measurement allows us to directly evaluate the fission models at excitation energies of fast neutrons, which are relevant for next-generation nuclear reactors. The present data, in agreement with model calculations, do not support the recently reported anomaly in the fission-fragment yields of ^{239}U, and they confirm the persistence of spherical shell effects in the Sn region at excitation energies exceeding the fission barrier by a few mega-electron volts.

Ultrafast Light Switching of Ferromagnetism in EuSe.

We demonstrate that light resonant with the band gap forces the antiferromagnetic semiconductor EuSe to enter ferromagnetic alignment in the picosecond timescale. A photon generates an electron-hole pair, whose electron forms a supergiant spin polaron of magnetic moment of nearly 6000 Bohr magnetons. By increasing the light intensity, the whole of the illuminated region can be fully magnetized. The key to the novel large photoinduced magnetization mechanism is the huge enhancement of the magnetic susceptibility when both antiferromagnetic and ferromagnetic interactions are present in the material and are of nearly equal magnitude, as is the case in EuSe.

Quasifree (p, 2p) Reactions on Oxygen Isotopes: Observation of Isospin Independence of the Reduced Single-Particle Strength.

Quasifree one-proton knockout reactions have been employed in inverse kinematics for a systematic study of the structure of stable and exotic oxygen isotopes at the R^{3}B/LAND setup with incident beam energies in the range of 300-450 MeV/u. The oxygen isotopic chain offers a large variation of separation energies that allows for a quantitative understanding of single-particle strength with changing isospin asymmetry. Quasifree knockout reactions provide a complementary approach to intermediate-energy one-nucleon removal reactions. Inclusive cross sections for quasifree knockout reactions of the type ^{A}O(p,2p)^{A-1}N have been determined and compared to calculations based on the eikonal reaction theory. The reduction factors for the single-particle strength with respect to the independent-particle model were obtained and compared to state-of-the-art ab initio predictions. The results do not show any significant dependence on proton-neutron asymmetry.

Strong Neutron Pairing in core+4n Nuclei.

The emission of neutron pairs from the neutron-rich N=12 isotones ^{18}C and ^{20}O has been studied by high-energy nucleon knockout from ^{19}N and ^{21}O secondary beams, populating unbound states of the two isotones up to 15 MeV above their two-neutron emission thresholds. The analysis of triple fragment-n-n correlations shows that the decay ^{19}N(-1p)^{18}C^{*}→^{16}C+n+n is clearly dominated by direct pair emission. The two-neutron correlation strength, the largest ever observed, suggests the predominance of a ^{14}C core surrounded by four valence neutrons arranged in strongly correlated pairs. On the other hand, a significant competition of a sequential branch is found in the decay ^{21}O(-1n)^{20}O^{*}→^{18}O+n+n, attributed to its formation through the knockout of a deeply bound neutron that breaks the ^{16}O core and reduces the number of pairs.

Characterization of CD34+ hematopoietic cells in systemic mastocytosis: Potential role in disease dissemination.

BACKGROUND: Recent studies show that most systemic mastocytosis (SM) patients, including indolent SM (ISM) with (ISMs+) and without skin lesions (ISMs-), carry the KIT D816V mutation in PB leukocytes. We investigated the potential association between the degree of involvement of BM hematopoiesis by the KIT D816V mutation and the distribution of different maturation-associated compartments of bone marrow (BM) and peripheral blood (PB) CD34+ hematopoietic precursors (HPC) in ISM and identified the specific PB cell compartments that carry this mutation. METHODS: The distribution of different maturation-associated subsets of BM and PB CD34+ HPC from 64 newly diagnosed (KIT-mutated) ISM patients and 14 healthy controls was analyzed by flow cytometry. In 18 patients, distinct FACS-purified PB cell compartments were also investigated for the KIT mutation. RESULTS: ISM patients showed higher percentages of both BM and PB MC-committed CD34+ HPC vs controls, particularly among ISM cases with MC-restricted KIT mutation (ISMMC ); this was associated with progressive blockade of maturation of CD34+ HPC to the neutrophil lineage from ISMMC to multilineage KIT-mutated cases (ISMML ). Regarding the frequency of KIT-mutated cases and cell populations in PB, variable patterns were observed, the percentage of KIT-mutated PB CD34+ HPC, eosinophils, neutrophils, monocytes and T cells increasing from ISMs-MC and ISMs+MC to ISMML patients. CONCLUSION: The presence of the KIT D816V mutation in PB of ISM patients is associated with (early) involvement of circulating CD34+ HPC and multiple myeloid cell subpopulations, KIT-mutated PB CD34+ HPC potentially contributing to early dissemination of the disease.

The effect of profession on burnout in hospital staff.

Background: A high level of burnout has been described in health professionals. However, literature regarding other hospital employees is scarce. Aims: To assess the prevalence of burnout in different professional groups of hospital staff and how the professional category is associated with levels of burnout. Methods: Employees of a University Hospital in Portugal completed a self-administered online questionnaire in 2014-2015. We used the Portuguese version of the Maslach Burnout Inventory-Human Services Survey and scored three dimensions of burnout (emotional exhaustion, depersonalization, personal accomplishment) as low, average or high. We estimated odds ratios (OR) and 95% confidence intervals (95% CI) by logistic regression, adjusting for age, sex, use of anxiolytic/antidepressant drugs and job satisfaction. Results: There was a 10% response rate; 368 questionnaires were available for analysis. High levels of burnout due to emotional exhaustion were observed in all professional categories. Nurses, administrative staff and technicians more frequently scored higher levels of emotional exhaustion (59%, 50% and 50%, respectively) and lack of personal accomplishment (41%, 52% and 38%, respectively) than physicians and healthcare assistants. Not all professionals scored highly for depersonalization. Emotional exhaustion scores were significantly lower in healthcare assistants than nurses (adjusted OR 0.26, 95% CI 0.10-0.64). Conclusions: Burnout affects all professional categories of hospital staff. Future studies should use larger, more representative samples of hospital staff, perform longitudinal analyses and analyse data on specifics of each professional category and other potential confounders.

Lower airway flow influences peak nasal inspiratory flow in school-aged children.

BACKGROUND: Rhinitis and asthma frequently coexist. Peak nasal inspiratory flow (PNIF) objectively evaluates nasal obstruction. Lower airway flow's impact on PNIF has seldom been analysed in children. We aimed to study the associations between PNIF and: 1)forced expiratory volume in one second (FEV1) and peak expiratory flow (PEF) in children with allergic rhinitis and asthma and healthy controls; 2)allergic rhinitis and asthma control subjective evaluation. METHODS: Sequential assessments of PNIF before and after nasal decongestion and spirometry with bronchodilation test were performed in 65 children (6-12 years) with allergic rhinitis and asthma, and 24 gender, age-matched healthy controls. The Control of Allergic Rhinitis and Asthma Test in children (CARATkids) was used for control assessment. Associations were investigated by multiple linear regression models. RESULTS: Baseline and decongested PNIF correlated with baseline and post-bronchodilation FEV1 and PEF, observed independently of rhinitis and asthma diagnosis. The best model for PNIF included PEF, age and gender. No association was found between PNIF and CARATkids scores, except for nasal obstruction self-report. CONCLUSION: In school-aged children, besides age and gender, PEF values should ideally be known to interpret PNIF values. PNIF can be complementary to subjective control assessment in children with allergic rhinitis and asthma.

Participation of osteoclastogenic factors in immunopathogenesis of human chronic periapical lesions.

BACKGROUND: Chronic periapical lesions (CPLs) are common lesions of the oral cavity and are the result of caries, tooth fracture, iatrogenic causes, or factors causing contamination and pulp necrosis. Inflammatory cells participate in the expansion of CPLs by releasing factors that stimulate or inhibit osteolytic activity. The objective of this study was to investigate the participation of RANKL, TNF-α, cathepsin K, IL-33, and OPG in the development of radicular cysts (RCs) and periapical granulomas (PGs). METHODS: Paraffin-embedded sections of 30 RCs and 22 PGs were submitted to immunohistochemistry. RESULTS: Immunoexpression of the proteins studied was observed in the epithelium and capsule of RCs, as well as in connective tissue of PGs. The expression of the osteoclastogenic factors studied differed significantly in RCs and PGs (P < .001), with lower expression of OPG in RCs. In PGs, the lowest expression was observed for cathepsin K. Comparison of the 2 lesions showed a similar participation of RANKL and IL33, while a significant difference was observed for OPG (P < .001), TNF-α (P = .002), and cathepsin K (P = .016). No association of the expression of the proteins with lesions size was observed. CONCLUSIONS: This study demonstrated the participation of RANKL, TNF-α, IL-33, cathepsin K, and OPG in the development of RCs and PGs, with emphasis on the highest immunoreactivity of cathepsin in RCs and TNF-α and OPG in PGs. OPG possibly determines the slower growth of PGs compared to RCs.

Identification and characterization of the bZIP transcription factor involved in zinc homeostasis in cereals.

Members of the basic leucine zipper family, as bZIP19, are considered to be essential regulators of the adaptation to zinc deficiency. Knowing that this gene as well as its targets are conserved in the plant kingdom, we followed an in silico approach to identify and characterize the bzip19 gene in cereals. Through BLASTp in Phytozome database, 33 bzip19 genes were identified on the genomes of Oryza sativa, Sorghum bicolor, Zea mays, Glycine max, Triticum aestivum, and Brachypodium distachyon. The analysis of conserved motifs and bZIP domains was performed using MEME and PFAM databases. In 25 of these genes, CysHis-motifs at the basic N-terminal region were found. This motif is conserved in group bZIP and suggested to play a role as a Zn-sensor. Regarding their phylogeny, it was possible to infer orthologous groups and explore the evolutionary relationship between these BZIP19 proteins. Data mining allowed us to select eight putative orthologous whose expression profile was analyzed under stress conditions in the Genevestigator platform. The comparison between the expression profiles of these eight putative orthologous and the original Arabidopsis bzip19 also seems to indicate conserved transcriptional regulation. Thus, considering that modified expression of bZIP19 genes has already been confirmed as an efficient tool to improve Arabidopsis tolerance to Zn deficiency, and that these new bZIP orthologous have a high level of conservation when compared to the original bZIP19 sequence, they can be useful for the development of tolerant crops enabling plants to grow in areas of low zinc bioavailability.

Collagen type IV-related nephropathies in Portugal: pathogenic COL4A3 and COL4A4 mutations and clinical characterization of 25 families.

Pathogenic mutations in genes COL4A3/COL4A4 are responsible for autosomal Alport syndrome (AS) and thin basement membrane nephropathy (TBMN). We used Sanger sequencing to analyze all exons and splice site regions of COL4A3/COL4A4, in 40 unrelated Portuguese probands with clinical suspicion of AS/TBMN. To assess genotype-phenotype correlations, we compared clinically relevant phenotypes/outcomes between homozygous/compound heterozygous and apparently heterozygous patients. Seventeen novel and four reportedly pathogenic COL4A3/COL4A4 mutations were identified in 62.5% (25/40) of the probands. Regardless of the mutated gene, all patients with ARAS manifested chronic renal failure (CRF) and hearing loss, whereas a minority of the apparently heterozygous patients had CRF or extrarenal symptoms. CRF was diagnosed at a significantly younger age in patients with ARAS. In our families, the occurrence of COL4A3/COL4A4 mutations was higher, while the prevalence of XLAS was lower than expected. Overall, a pathogenic COL4A3/COL4A4/COL4A5 mutation was identified in >50% of patients with fewer than three of the standard diagnostic criteria of AS. With such a population background, simultaneous next-generation sequencing of all three genes may be recommended as the most expedite approach to diagnose collagen IV-related glomerular basement membrane nephropathies.

Collagen type IV-related nephropathies in Portugal: pathogenic COL4A5 mutations and clinical characterization of 22 families.

Alport syndrome (AS) is caused by pathogenic mutations in the genes encoding α3, α4 or α5 chains of collagen IV (COL4A3/COL4A4/COL4A5), resulting in hematuria, chronic renal failure (CRF), sensorineural hearing loss (SNHL) and ocular abnormalities. Mutations in the X-linked COL4A5 gene have been identified in 85% of the families (XLAS). In this study, 22 of 60 probands (37%) of unrelated Portuguese families, with clinical diagnosis of AS and no evidence of autosomal inheritance, had pathogenic COL4A5 mutations detected by Sanger sequencing and/or multiplex-ligation probe amplification, of which 12 (57%) are novel. Males had more severe and earlier renal and extrarenal complications, but microscopic hematuria was a constant finding irrespective of gender. Nonsense and splice site mutations, as well as small and large deletions, were associated with younger age of onset of SNHL in males, and with higher risk of CRF and SNHL in females. Pathogenic COL4A3 or COL4A4 mutations were subsequently identified in more than half of the families without a pathogenic mutation in COL4A5. The lower than expected prevalence of XLAS in Portuguese families warrants the use of next-generation sequencing for simultaneous COL4A3/COL4A4/COL4A5 analysis, as first-tier approach to the genetic diagnosis of collagen type IV-related nephropathies.

Keratocystic odontogenic tumour arising as a periapical lesion.

AIM: To document a case of a keratocystic odontogenic tumour (KOT) involving the apical region in the maxilla mimicking a periapical lesion of endodontic origin. SUMMARY: Benign and malignant tumours, including odontogenic lesions, can be erroneously diagnosed as periapical radiolucencies. KOTs mimicking periapical lesions of endodontic origin are uncommon, especially when the lesions involve the maxilla. This article describes a 55-year-old man with a well-delimited, oval-shaped, radiolucent lesion, occupying the middle and apical third of teeth 22 and 23. After 30 days, the clinical and radiographic findings remained unchanged and the patient was referred for surgical removal of the lesion. Clinical, radiographic and histopathological features are also discussed and compared with current literature.

Analysis of the frequency and nature of hyaline ring granulomas in inflammatory odontogenic cysts.

AIM: To determine the prevalence of hyaline ring granulomas (HRGs) in a large case series of inflammatory odontogenic cysts, and to investigate the nature of these structures. METHODOLOGY: All records from the patients diagnosed with inflammatory odontogenic cysts between January 1970 and April 2009 were reviewed. Histologic sections were evaluated by light microscopy and cases with HRGs for which sufficient biological material was available were submitted to histochemical analysis (Masson's trichrome) and immunohistochemistry (CD34, CD68 and collagen IV). RESULTS: Twenty-two (3.3%) of the 661 cases of inflammatory odontogenic cysts diagnosed during the study period presented HRGs. The relative frequency of HRGs was higher amongst residual radicular cysts (6.1%), followed by paradental cysts (5.6%) and radicular cysts (3.0%). HRGs appeared as roughly circular homogeneous/fibrillar masses in 14 (63.6%) cases and as round structures enclosing amorphous material in 3 (13.6%) cases. Most (77.8%) roughly circular homogeneous/fibrillar masses were positive for collagen, whereas all (100.0%) round structures enclosing amorphous material were negative for this protein. Immunohistochemistry showed that most mononucleated cells and all multinucleated giant cells were positive for CD68, but negative for CD34, in all cases. In addition, collagen IV immunostaining was negative in amorphous structures and weakly positive in homogeneous/fibrillar masses. CONCLUSIONS: The present results suggest a very low frequency of HRGs in inflammatory odontogenic cysts and support the hypothesis that these structures arise from the implantation of foreign material, most likely food particles of plant or vegetable origin. The diverse microscopic features of HRG possibly represent different developmental stages of this structure.