Oxygen-selective regulation of cyclic di-GMP synthesis by a globin coupled sensor with a shortened linking domain modulates Shewanella sp. ANA-3 biofilm.

Bacteria utilize heme proteins, such as globin coupled sensors (GCSs), to sense and respond to oxygen levels. GCSs are predicted in almost 2000 bacterial species and consist of a globin domain linked by a central domain to a variety of output domains, including diguanylate cyclase domains that synthesize c-di-GMP, a major regulator of biofilm formation. To investigate the effects of middle domain length and heme edge residues on GCS diguanylate cyclase activity and cellular function, a putative diguanylate cyclase-containing GCS from Shewanella sp. ANA-3 (SA3GCS) was characterized. Binding of O2 to the heme resulted in activation of diguanylate cyclase activity, while NO and CO binding had minimal effects on catalysis, demonstrating that SA3GCS exhibits greater ligand selectivity for cyclase activation than many other diguanylate cyclase-containing GCSs. Small angle X-ray scattering analysis of dimeric SA3GCS identified movement of the cyclase domains away from each other, while maintaining the globin dimer interface, as a potential mechanism for regulating cyclase activity. Comparison of the Shewanella ANA-3 wild type and SA3GCS deletion (ΔSA3GCS) strains identified changes in biofilm formation, demonstrating that SA3GCS diguanylate cyclase activity modulates Shewanella phenotypes.

Bone effects of epidural and intra-articular glucocorticoids: a systematic literature review / Efectos óseos de los glucocorticoides epidurales e intraarticulares: revisión sistemática de la literatura

Osteoporosis and vertebral and non-vertebral fractures are common in glucocorticoids (GC) treated patients. Oral GC treatment leads to bone loss, particularly of trabecular bone. The benefits of GC used in rheumatological and traumatological disorders are known but they would have possible negative effects on bone. This systematic review aimed to evaluate the effects of epidural steroid injections (ESI), and intra-articular and intramuscular GC administration on bone mineral density (BMD) and fragility fractures. A systematic review of Medline/PubMed, Cochrane, and LILACS up to November 2020 was conducted. Meta-analyses, systematic reviews, randomized and non-randomized controlled trials, and prospective and retrospective studies comparing the effect of ESI, intra-articular or intramuscular GC used compared to a control group or baseline measurements were included. Results: A total of 8272 individuals were included among the 13 selected articles (10 about ESI and 3 about intra-articular GC; no article was found evaluating intramuscular GC). Only a few studies showed a negative effect of ESI on bone in the qualitative analysis considering osteopenia and osteoporosis in lumbar spine, femoral neck and total hip and BMD as surrogate outcomes. On the other hand, the qualitative analysis showed that most studies found an increased risk of fragility fracture. However, only two studies could be included in the quantitative analysis, in which there were no differences between patients exposed to ESI versus controls in all evaluated regions. In conclusion, there was insufficient evidence to suggest that ESI and intra-articular GC, unlike oral GC, negatively affect bone mass. Longitudinal studies are needed to obtain more knowledge regarding the effect of ESI or intra-articular GC on BMD and fragility fractures. (AU)

La osteoporosis y las fracturas vertebrales y no vertebrales son comunes en pacientes tratados con glucocorticoides (GC). El tratamiento oral con GC conduce a la pérdida ósea, particularmente del hueso trabecular. Los beneficios de los GC utilizados en patologías reumatológicas y traumatológicas son conocidos, pero tendrían posibles efectos negativos sobre el hueso. Esta revisión sistemática tuvo como objetivo evaluar los efectos de las inyecciones epidurales de esteroides (ESI), GC intraarticulares e intramusculares sobre la densidad mineral ósea (DMO) y las fracturas por fragilidad. Se realizó una revisión sistemática de Medline/PubMed, Cochrane y LILACS hasta noviembre de 2020. Se incluyeron metanálisis, revisiones sistemáticas, ensayos controlados aleatorizados y no aleatorizados, estudios prospectivos y retrospectivos que compararon el efecto de ESI, GC intraarticular o intramuscular utilizado en comparación con un grupo de control o mediciones iniciales. Resultados: Se incluyeron un total de 8272 individuos entre los 13 artículos seleccionados (10 sobre ESI y 3 sobre GC intraarticular; no se encontró ningún artículo que evaluara GC intramuscular). Solo unos pocos estudios mostraron un efecto negativo del ESI sobre el hueso en el análisis cualitativo considerando la osteopenia y la osteoporosis en la columna lumbar, el cuello femoral y la cadera total y la DMO como un resultado indirecto. Por otro lado, el análisis cualitativo mostró que la mayoría de los estudios encontraron un mayor riesgo de fractura por fragilidad. Sin embargo, solo dos estudios pudieron incluirse en el análisis cuantitativo, en los que no hubo diferencias entre los pacientes expuestos a ESI versus los controles en todas las regiones evaluadas. En conclusión, no hallamos datos suficientes para sugerir que la ESI y los GC intraarticulares, a diferencia de los GC orales, afectan negativamente a la pérdida ósea. Se necesitan estudios longitudinales para obtener más conocimiento sobre el efecto de ESI o GC intraarticular en la DMO y las fracturas por fragilidad. (AU)

Effect of Teriparatide on Bone Mineral Density and Bone Markers in Real-Life: Argentine Experience.

Purpose: To evaluate the effect of teriparatide (TPTD) on bone mineral density (BMD) and bone markers under clinical practice conditions. To assess whether the results in real-life match those published in clinical trials. Methods: Cross-sectional study of postmenopausal women treated with TPTD for at least 12 months. Results: 264 patients were included in the study. Main characteristics are as follows: age: 68.7 ± 10.2 years, previous fractures: 57.6%, and previously treated with antiresorptive (AR-prior): 79%. All bone turnover markers studied significantly increased after 6 months. CTX and BGP remained high up to 24 months, but total and bone alkaline phosphatase returned to basal values at month 18. There was a significant increase in lumbar spine (LS) BMD after 6 months (+6.2%), with a maximum peak at 24 months (+13%). Femoral neck (FN) and total hip (TH) BMD showed a significant increase later than LS (just at month 12), reaching a maximum peak at month 24 (FN + 7.9% and TH + 5.5%). A significant increase in LS BMD was found from month 6 to month 24 compared to basal in both AR-naïve, and AR-prior patients (+16.7% and +10.5%, respectively), without significant differences between the two groups. Comparable results were found in FN and TH BMD. Main conclusions. As reported in real-life clinical studies, treatment of osteoporotic postmenopausal women with TPTD induced a significant increase in bone turnover markers from month 6 onward and an increase in BMD from months 6-12 with continuous gain up to month 24. The real-life results of our study matched the results of randomized clinical trials. In addition, TPTD induced an increase in BMD, regardless of the previous use of AR.

Hypovitaminosis D in patients with type 2 diabetes: risk factors and association with glycemic control and established microvascular complications

Introduction: Several studies reported than vitamin D deficiency increases the risk of macrovascular and microvascular disease in patients with type 2 diabetes (T2DM). We investigated the plasma levels of 25OHD in adult patients T2DM, risk factors for 25OHD deficiency and the relationship between 25OHD, glycemic control and chronic complications of T2DM. Methods: A cross-sectional study was carried out, in which 25OHD levels were evaluated in adult patients (over 18 years) with T2DM. Correlation analyses were performed to evaluate the interdependence of the 25OHD with other continuous variables. A receiver operating characteristic analysis was also performed to identify cutoff values for diagnosing vitamin D deficiency. Logistic regression was performed to identify the independent association between vitamin D deficiency and the variables associated with lower 25OHD. Results: 208 patients were analyzed. The mean age of the patients was 62 years.  The 25OHD level was 19 ng/ml (IQR 13.28-24.43), 59.78% had vitamin D deficiency, and 10.33% had severe deficiency. Glycemia, HbA1c, and BMI were negatively correlated with 25OHD. Cutoff point for vitamin D deficiency was 33.39 kg/m2 for body mass index (BMI), 123 mg/dl for glycemia, and 6.65% for HbA1c. In multivariate logistic regression, BMI>33.39 kg/m2, glycemia >123.5 mg/dl, and albuminuria presented higher odds of vitamin D deficiency. Conclusion: Vitamin D deficiency was highly prevalent among patients with T2DM. Low levels were related to higher fasting plasma glucose, higher BMI, and diabetic nephropathy.

Introducción: Varios estudios reportaron que la deficiencia de vitamina D aumenta el riesgo de enfermedad macrovascular y microvascular en pacientes con diabetes tipo 2 (DM2). Investigamos los niveles de 25OHD en adultos con DM2, factores de riesgo de deficiencia de 25OHD y relación entre 25OHD, control glucémico y complicaciones crónicas de la DM2. Métodos: Se realizó un estudio transversal en el que se evaluaron los niveles de 25OHD en adultos (mayores de 18 años) con DM2. Se realizaron análisis de correlación para evaluar la interdependencia de la 25OHD con otras variables continuas. Se realizó un análisis de las características operativas del receptor para identificar valores de corte para diagnóstico de deficiencia de vitamina D. Se realizó una regresión logística para identificar asociación independiente entre deficiencia de 25OHD y variables asociadas con una menor 25OHD. Resultados: Se analizaron 208 pacientes. La edad media fue 62 años. El nivel de 25OHD fue 19 ng/ml (IQR 13.28-24.43), 59.78% tenía deficiencia de vitamina D y 10.33% tenía deficiencia severa. Glucemia, HbA1c y IMC correlacionaron negativamente con 25OHD. El punto de corte para deficiencia de vitamina D fue 33,39 kg/m2 para índice de masa corporal (IMC), 123 mg/dl para glucemia y 6,65% para HbA1c. En la regresión logística multivariada, IMC >33,39 kg/m2, glucemia >123,5 mg/dl y albuminuria presentaron mayores probabilidades de deficiencia de vitamina D. Conclusión principal: La deficiencia de vitamina D fue altamente prevalente en los pacientes con DM2. Niveles bajos de 25OHD se relacionaron con mayor glucemia, mayor IMC y nefropatía diabética.

Ruffling is essential for Staphylococcus aureus IsdG-catalyzed degradation of heme to staphylobilin.

Non-canonical heme oxygenases are enzymes that degrade heme to non-biliverdin products within bacterial heme iron acquisition pathways. These enzymes all contain a conserved second-sphere Trp residue that is essential for enzymatic turnover. Here, UV/Vis absorption (Abs) and circular dichroism (CD) spectroscopies were employed to show that the W67F variant of IsdG perturbs the heme substrate conformation. In general, a dynamic equilibrium between "planar" and "ruffled" substrate conformations exists within non-canonical heme oxygenases, and that the second-sphere Trp favors population of the "ruffled" substrate conformation. 1H nuclear magnetic resonance and magnetic CD spectroscopies were used to characterize the electronic structures of IsdG and IsdI variants with different substrate conformational distributions. These data revealed that the "ruffled" substrate conformation promotes partial porphyrin-to­iron electron transfer, which makes the meso carbons of the porphyrin ring susceptible to radical attack. Finally, UV/Vis Abs spectroscopy was utilized to quantify the enzymatic rates, and electrospray ionization mass spectrometry was used to identify the product distributions, for variants of IsdG with altered substrate conformational distributions. In general, the rate of heme oxygenation by non-canonical heme oxygenases depends upon the population of the "ruffled" substrate conformation. Also, the production of staphylobilin or mycobilin by these enzymes is correlated with the population of the "ruffled" substrate conformation, since variants that favor population of the "planar" substrate conformation yield significant amounts of biliverdin. These data can be understood within the framework of a concerted rearrangement mechanism for the monooxygenation of heme to meso-hydroxyheme by non-canonical heme oxygenases.

Microbial Diversity in Cultivated and Feral Vanilla Vanilla planifolia Orchids Affected by Stem and Rot Disease.

The worldwide production of vanilla, a native orchid from Mexico, is greatly affected by stem and root rot disease (SRD), typically associated with Fusarium oxysporum fungi. We hypothesized that the presence of Fusarium species in vanilla is not sufficient for the plant to express symptoms of the disease. We described the taxonomic composition of endophytic microbiomes in symptomatic and asymptomatic vanilla plants using 16S and ITS rDNA metabarcoding, and ITS Sanger sequences generated from fungal isolates. We compared the bacterial and fungal diversity in vanilla plants from a long-term plantation, and from feral plants found near abandoned plantations that did not present SRD symptoms. No significant differences were found in the species richness of the bacterial and fungal microbiome among feral, or asymptomatic and symptomatic cultivated vanilla. However, significant differences were detected in both fungal and bacterial diversity from different organs in the same plant, with roots being more diverse than stems. We found that Proteobacteria and Actinobacteria, as well as the fungal families Nectriaceae and Xylariaceae, constitute the core of the vanilla microbiome that inhabits the root and stem of both cultivated and feral plants. Our work provides information on the microbial diversity associated to root and stem rot in vanilla and lays the groundwork for a better understanding of the role of the microbiome in vanilla fungal diseases.

Prevalence of Sarcopenia and Whole-Body Composition in Rheumatoid Arthritis.

BACKGROUND: Rheumatoid arthritis (RA) is a chronic autoimmune disease that leads to joint deformity and disability, as well as muscle involvement. Sarcopenia is characterized by a progressive age-related loss of muscle mass and strength. AIM: The aim of this study was to evaluate the prevalence of sarcopenia and possible contributing factors associated with sarcopenia in RA patients. PATIENTS AND METHODS: Adult RA patients (n = 105) of both sexes and 100 subjects as control group (CG) matched by age, sex, and body mass index were included in this cross-sectional study. Whole-body composition was measured by dual-energy x-ray absorptiometry. Sarcopenia was defined according to European Working Group on Sarcopenia in Older People 2 as low muscle strength (handgrip) and low muscle mass (appendicular skeletal muscle mass [ASM] index by dual-energy x-ray absorptiometry). The association between sarcopenia and associated factors was evaluated using logistic regression analyses. RESULTS: Significantly lower percentage of lean mass and ASM were found in the whole RA group compared with controls. However, lower lean parameters (total lean mass, percentage of lean mass, and ASM) were observed only in female subjects. The ASM index was significantly lower in female subjects with RA (RA 31.0% vs CG 11.9%) without differences in male subjects. On the other hand, fat mass and most adipose indices were significantly higher in both female and male subjects with RA. Female RA patients had higher prevalence of sarcopenia and sarcopenic obesity. Through univariate logistic regression analysis, the time of corticosteroids use, cumulative corticosteroid dose, previous fragility fractures, total lean mass, and ASM were associated with sarcopenia. CONCLUSIONS: Higher prevalence of sarcopenia and sarcopenic obesity were found in female RA patients. Sarcopenia was found in younger female subjects with RA compared with healthy control subjects. Sarcopenia was associated with previous fragility fractures in female patients with RA.

Negative association between 25-hydroxyvitamin D and inflammatory markers in rheumatologic diseases / Asociación negativa entre 25-hidroxi vitamina D y los marcadores inflamatorios en enfermedades reumatológicas

Objective: The main purpose of this study was to evaluate serum 25-hydroxyvitamin D (25OHD) levels and its association with in"ammatory markers in patients with rheumatologic diseases (RD). Methods: A cross-sectional study in 154 women with RD (rheumatoid arthritis, spondyloarthritis and other connective tissue diseases) and 112 healthy individuals as a control group (CG) was carried out. Results: No differences in serum and urine calcium, serum phosphate, and urinary deoxypyridinoline were found. RD group had lower 25OHD and higher PTH compared to CG. RD group had higher C-reactive protein (CRP) and erythrocyte sedimentation rate (ESR) compared to CG. The overall mean level of 25OHD (ng/ml) was 26.3±12.0 in the CG and 19.4±6.8 in the RD group (p<0.0001). Moreover, CG had lower percentage of individuals with 25OHD de!ciency compared to RD (29.9% vs 53.2%). The femoral neck BMD was signi!cantly lower in postmenopausal RD women compared to CG. 25OHD levels signi!cantly correlated with ESR and CRP as in"ammatory markers. Age, BMI, presence of RD, and CRP were signi!cantly and negatively associated with 25OHD levels through linear regression analysis. According to univariate logistic regression analysis for 25OHD deficiency (<20 ng/ml), a significant and negative association with BMI, presence of RD, ESR and CRP were found. Conclusion: Patients with RD had lower 25OHD levels than controls and the presence of a RD increases by 2.66 the risk of vitamin D de!ciency. In addition, 25OHD has a negative correlation with ESR and CRP as in"ammatory markers. (AU)

Objetivo El objetivo principal de este estudio fue evaluar los niveles séricos de 25-hidroxivitamina D (25OHD) y su asociación con marcadores inflamatorios en enfermedades reumatológicas. Materiales y métodos: Se realizó un estudio transversal en 154 mujeres con enfermedades reumatológicas (artritis reumatoide, espondiloartritis y otras enfermedades del tejido conectivo) y 112 individuos sanos como grupo control (GC). Resultados: No se encontraron diferencias en el calcio sérico y urinario, el fosfato sérico y la desoxipiridinolina urinaria entre el GC y los sujetos con enfermedades reumatológicas. El grupo de pacientes con enfermedades reumatológicas tenía 25OHD más bajo y PTH más alto en comparación con el GC. Asimismo, el grupo de individuos con enfermedades reumatológicas tenía proteína C reactiva (PCR) y velocidad de eritrosedimentación (VES) más altas en comparación con el GC. El nivel de 25OHD (ng/ml) fue 26,3±12,0 en el GC y 19,4±6,8 en el grupo con enfermedades reumatológicas (p<0,0001). Además, el GC presentó un porcentaje menor de deficiencia de 25OHD en comparación con el grupo con enfermedades reumatológicas (29,9% vs 53,2%). La DMO del cuello femoral fue significativamente menor en las mujeres posmenopáusicas con enfermedades reumatológicas en comparación con el GC. La 25OHD correlacionó significativamente con la VES y la PCR como marcadores inflamatorios. El análisis de regresión lineal mostró que la edad, el IMC, la presencia de una enfermedad reumatológica y la PCR se asociaron significativa y negativamente con los niveles de 25OHD. Mientras que el análisis de regresión logística univariada mostró que la deficiencia de 25OHD (<20 ng/ml), se asoció significativa y negativamente con el IMC, la presencia de una enfermedad reumatológica, la VES y los niveles de PCR. Conclusiones: Los pacientes con enfermedades reumatológicas tenían niveles de 25OHD más bajos que los controles y la presencia de una enfermedad reumatológica aumenta en 2.66 el riesgo de deficiencia de vitamina D. Además, la 25OHD mostró correlación negativa con la VES y la PCR como marcadores inflamatorios. (AU)

Vertebral fractures in adult women with type 2 diabetes mellitus / Fracturas vertebrales en mujeres adultas con diabetes mellitus tipo 2

Introduction. Diabetes is a chronic disease associated with important comorbidities. Type 2 diabetes (T2DM) is associated with a three times increased risk of hip fracture but reports describing potential associations with vertebral fractures (VF) are contradictory. Our objective was to evaluate the factors involved in the prevalent VF in women with and without T2DM. Materials and methods. A cross-sectional design was used and the relationship between morphometric VF and T2DM in adult women was evaluated. The cases were adult women with morphometric VF and the controls were adult women without VF. Thoracic and spinal radiographs in lateral and antero-posterior projections were obtained. Bone mineral density (BMD) values of the lumbar spine (L-BMD) were measured by DXA. Results. A greater number of women with T2DM were found in the VF group (61% vs 31.5%). Non-T2DM women with VF were significantly older and with lower L-BMD than non-T2DM without VF. We observed a negative correlation between age and L-BMD (r=-0.463) in non-T2DM women, but not in the T2DM with FV group. T2DM was a risk factor for prevalent VF with OR of 3.540 (IC95% 1.750-7.160). Conclusion. Our study showed a higher prevalence of T2DM in the VF group. T2DM women with VF were younger and had higher L-BMD than non-T2DM women, L-BMD did not correlate with age and VF were not distributed according to BMD-L and age. (AU)

Introducción. La diabetes es una enfermedad crónica asociada con comorbilidades importantes. La diabetes tipo 2 (DM2) se asocia con un riesgo tres veces mayor de fractura de cadera pero la asociación con fracturas vertebrales (FV) es contradictoria. Nuestro objetivo fue evaluar los factores involucrados en las FV prevalentes en mujeres adultas con y sin DM2. Materiales y métodos. Se realizó un diseño transversal y se evaluó la relación entre FV morfométrica y DM2 en mujeres adultas. Los casos fueron mujeres adultas con FV morfométricas y los controles fueron mujeres adultas sin FV. Se obtuvieron radiografías torácicas y espinales en proyecciones lateral y anteroposterior. Los valores de densidad mineral ósea (DMO) de la columna lumbar (DMO-L) se midieron por DXA. Resultados. Se observó un mayor número de mujeres con DM2 en el grupo de FV (61% frente a 31.5%). Las mujeres sin DM2 con FV eran significativamente mayores y con una DMO-L más baja que las mujeres sin DM2 sin FV. Observamos una correlación negativa entre la edad y la DMO-L (r= -0.463) en mujeres sin DM2 y FV, pero no en DM2 con FV. La DM2 fue un factor de riesgo para FV prevalente con un OR 3.540 (IC95% 1.750-7.160). Conclusión. Nuestro estudio demostró una mayor prevalencia de DM2 en el grupo de FV. Las mujeres con DM2 y FV eran más jóvenes y tenían mayor DMO-L que las mujeres sin DM2, la DMO-L no correlacionó con la edad y las FV no se distribuyeron de acuerdo a la DMO-L y edad. (AU)

CfbA promotes insertion of cobalt and nickel into ruffled tetrapyrroles in vitro.

The nickel chelatase CfbA is the smallest member of the chelatase family, but the mechanism by which this enzyme inserts nickel into sirohydrochlorin is unknown. In order to gain mechanistic insight, metal binding, tetrapyrrole binding, and enzyme activity were characterized for a variety of substrates using several spectroscopic and computational approaches. Mass spectrometery and magnetic circular dichroism experiments revealed that CfbA binds an octahedral, high-spin metal substrate. UV/Vis absorption spectroscopy demonstrated that the enzyme binds a wide range of tetrapyrrole substrates and perturbs their electronic structures. Based upon activity assays, CfbA promotes insertion of cobalt and nickel into several tetrapyrroles, including cobalt insertion into protopophyrin IX. Finally, density functional theory models were developed which strongly suggest that observed spectral changes upon binding to the enzyme can be explained by tetrapyrrole ruffling, but not deprotonation or saddling. The observation of an octahedral, high-spin metal bound to CfbA leads to a generalization for all class II chelatases: these enzymes bind labile metal substrates and metal desolvation is not a rate-limiting step. The conclusion that CfbA ruffles its tetrapyrrole substrate reveals that the CfbA mechanism is different from that currently proposed for ferrochelatase, and identifies an intriguing correlation between metal substrate specificity and tetrapyrrole distortion mode in chelatases.

Osteonecrosis de los maxilares asociada a medicamentos (ONMM): guía redactada por expertos invitados por la Asociación Argentina de Osteología y Metabolismo Mineral y por la Sociedad Argentina de Osteoporosis / Medication-related osteonecrosis of the jaw (MRONJ): guideline prepared by experts invited by the Argentine Association of Osteology and Mineral Metabolism, and the Argentine Society for Osteoporosis

La osteonecrosis maxilar asociada a medicamentos (ONMM=MRONJ como se conoce en la literatura en inglés) se define como un área ósea expuesta al medio bucal con más de ocho semanas de permanencia, en pacientes tratados con antirresortivos y/o antiangiogénicos y sin antecedentes de radioterapia en cabeza y cuello. Las fracturas ocasionan una morbimortalidad significativa y los antirresortivos son drogas eficaces y seguras para prevenirlas. Se utilizan principalmente en osteoporosis, pero también en enfermedades oncológicas como mieloma múltiple o metástasis óseas de tumores sólidos. La posología varía según el contexto clínico, siendo mayor la dosis y frecuencia de administración en oncología. Los antirresortivos actualmente más utilizados son los bifosfonatos (BF) y el denosumab (Dmab). Si bien los BF persisten largo tiempo en el tejido óseo, el Dmab tiene un mecanismo de acción reversible y su suspensión abrupta conlleva importante pérdida de masa ósea y riesgo aumentado de fracturas vertebrales múltiples. Ninguna droga puede ser suspendida ni espaciada sin autorización médica, dado que no es de competencia del odontólogo. El diagnóstico presuntivo de ONMM debe ser confirmado clínicamente por un odontólogo, quien solicitará imágenes radiológicas para establecer el estadio de la lesión. La anamnesis correcta permite establecer un diagnóstico diferencial entre ONMM, osteomielitis y osteorradionecrosis. La presentación clínica es variable y puede mostrar distintos estadios. La mayoría de los casos están precedidos por un procedimiento quirúrgico odontológico. Suele ser asintomática, aunque puede haber dolor si se localiza cerca de una estructura neuronal. La localización es variable: 62,3% se produce en el maxilar inferior. La incidencia de ONMM es baja, en un rango de 0,001 a 0,01% y tiene relación con las dosis y el tiempo de administración. La remoción de caries, la operatoria dental, la endodoncia y la rehabilitación protética fija o removible no se asocian a riesgo de ONMM. Con menos de 3 años de tratamiento antirresortivo se pueden efectuar terapéuticas quirúrgicas como exodoncias, apicectomías, cistectomías, tratamientos periodontales de raspaje y alisado subgingival sin riesgo. Con más de 3 años se aconseja evitar la realización de exodoncias y manipulación de tejido óseo. Ante la necesidad de realizar un procedimiento odontológico, no hay evidencia que avale que la suspensión transitoria del tratamiento antirresortivo pueda reducir el riesgo. Tampoco la medición de marcadores de remodelado óseo aporta datos de utilidad. Existen pocos datos en la literatura sobre la colocación de implantes dentales en pacientes que reciben drogas antirresortivas en dosis bajas; si bien existe ONMM asociada, su incidencia sería baja. Antes de iniciar un tratamiento antirresortivo se recomienda realizar interconsulta con el odontólogo para evaluar potenciales necesidades quirúrgicas. Quienes reciben antirresortivos deben realizar controles orales periódicos (semestrales) y, ante cualquier síntoma compatible con un estadio incipiente de ONMM, deben consultar a su odontólogo. El trabajo conjunto del médico y el odontólogo puede prevenir la aparición de la ONMM, un evento infrecuente, pero que puede generar elevada morbilidad en los pacientes. La comunicación fluida entre profesionales tenderá a evitar no solo la incertidumbre y desconfianza de los pacientes, sino también que se produzcan lesiones con la consecuente necesidad de tratamientos de mayor complejidad. (AU)

Medication-Related Osteonecrosis of the Jaw (MRONJ) is defined as a bone area exposed to the oral environment lasting more than eight weeks, in patients treated with antiresorptive and/or antiangiogenic drugs and without a history radiation therapy to the head and neck. Fractures cause significant morbidity and mortality, and antiresorptives are effective and safe drugs to prevent them. They are used to treat not only osteoporosis but also oncological diseases such as multiple myeloma or bone metastases from solid tumors. The dosage varies according to the clinical context; doses and frequencies of administration are higher in oncology. The most commonly used antiresorptive medications are bisphosphonates (BP) and denosumab (Dmab). Whereas BP persist for a long time in bone tissue, Dmab has a reversible mechanism of action and its discontinuation leads to significant loss of bone mass and an increased risk of multiple vertebral fractures. No drug can be suspended or spaced without medical authorization. Dentists should not take decisions about antiresorptive prescription. The presumptive diagnosis of MRONJ must be clinically confirmed by a dentist, who will order radiological studies to establish the stage of the injury. The correct anamnesis helps differentiate MRONJ from osteomyelitis and osteoradionecrosis. Clinical presentation is variable and can present different stages. Most of the cases are preceded by a dental surgical procedure. Usually MRONJ is asymptomatic although patients may feel pain if it is located near a neuronal structure. The location is variable: 62.3% occurs in the lower jaw. The incidence of MRONJ is low, in the range of 0.001 to 0.01%, and is related to the dose and time of administration. Caries removal, dental surgery, endodontics, fixed or removable prosthetic rehabilitation are not associated with risk of MRONJ. With less than 3 years of antiresorptive treatment, surgical therapies such as extractions, apicectomies, cystectomies, periodontal scaling treatments and subgingival smoothing can be performed without risk. With more than 3 years, it is advisable to avoid performing extractions and manipulating bone tissue. Given the need to perform a dental procedure, there is no evidence to support that the temporary suspension of antiresorptive treatment can reduce the risk. Nor does the measurement of bone turnover markers provide useful information. There are few data in the literature on the placement of dental implants in patients receiving antiresorptive drugs at low doses; although there might be an associated risk of MRONJ, its incidence appears to be low. Before starting antiresorptive treatment, consultation with the dentist is recommended to evaluate potential surgical needs. Patients receiving treatment with antiresorptive agents should undergo periodic oral controls (every six months) and in the event of any symptoms compatible with an early MRONJ stage, they should consult their dentists. The collaboration between physician and dentist can prevent the appearance of MRONJ, that is an infrequent event, but can generate high morbidity in patients. Fluid communication between professionals will tend to avoid, not only the uncertainty and distrust of patients, but also the occurrence of injuries needing complex treatments. (AU)

Análisis de la casuística de metástasis ováricas de cáncer de mama del Instituto de Oncología Á. H. Roffo / Analysis of the casuistry of ovarian metastases in breast cancer at the Ángel H. Roffo Oncology Institute

Objetivo El objetivo del presente trabajo es analizar las características de las pacientes con antecedente de cáncer de mama que desarrollaron metástasis ováricas. Material y método Se identificaron casos entre enero de 2000 y diciembre de 2017. Se estudiaron las siguientes variables: edad al inicio y edad de la aparición de la metástasis ovárica; tipo histológico; perfil ihq del tumor mamario y anexial; estadio; uni o bilateralidad; tratamiento; latencia entre primario de mama y secundarismo en ovario; presentación; diagnóstico presuntivo preoperatorio; tipo de cirugía: tratamiento posterior; sle y sg. Resultados Se identificaron 17 casos. La incidencia de metástasis ováricas de cáncer de mama fue del 0,3%. El 82% se presentó en premenopáusicas. En cuanto al tipo: 50% fueron ductales, 43,7% lobulillares y 6,2% ductolobulillares. El perfil inmunohistoquímico fue: 62,5% Luminales B y 40% Luminales A. Todas las pacientes presentaban otros sitios de metástasis a distancia. El 62,5% fueron bilaterales y el 68,7% menores de 10 cm. La inmunohistoquimica demostró que el 53,3% modificó sus características. El tiempo de latencia entre ambos eventos, definida como punto de corte antes o después de los 5 años del primario, resultó en una diferencia marcada con sobrevida promedio de 88,5 meses para las primeras y de 154,4 meses para las segundas, pero no resultó estadísticamente significativa. Conclusiones La metástasis ovárica de cáncer mamario es un evento infrecuente. Suele aparecer en pacientes jóvenes premenopáusicas. El tipo histológico más frecuente es el lobulillar y el perfil molecular predominante es el Luminal B. La aparición de masas anexiales bilaterales sólidas o sólido-quísticas menores de 10 cm en pacientes con enfermedad diseminada debe hacer sospechar este diagnóstico

Objective Analyze the characteristics of patients with a history of breast cancer who developed ovarian metastases. Materials and method Identification of cases between January and December of 2017. Variables studied: age at onset and of the appearance of ovarian metastasis; histological type; ihc profile of breast and adnexal tumor; stage; unit or bilaterality; treatment; latency between primary breast and ovarian secondary; presentation; preoperative diagnosis; type of surgery; subsequent treatment; les and sg. Results 17 cases identified. The incidence of ovarian metastases from breast cancer was 0.3%, 82% premenopausal. 50% were ductal, 43.7% lobulillar and 6.2% ductolobulillar. The molecular profile was 62.5% Luminal A and 40% Luminal B. All the patients presented other sites of distant metastasis. 62.5% were bilateral and 68.7% were less than 10 cm. Immunohistochemistry showed that 53.3% modified its characteristics. The time elapsed between events, defined as a cut-off point before or after 5 years of the primary, resulted in a marked difference with average survival of 88.5 months for the first and 154.4 months for the second, but not statistically significant. Conclusions Ovarian metastasis of breast cancer is an infrequent event. It usually appears in young premenopausal patients. Lobular histological type and Luminal B molecular profile are predominant. The appearance of adjoining or more solid masses smaller than 10 cm in patients with disseminated disease should raise suspicion this diagnos

Un caso de hipercalcemia hipocalciúrica de causa genética en niño prepúber / Genetic hypercalcemic hypocalciuria in a prepubertal boy

Un paciente de 12 años consultó por vómitos recurrentes asociados con cefaleas, con varios episodios durante 7 meses, y retraso ponderal secundario a esa sintomatología. Había recibido previamente un tratamiento con antibióticos e inhibidores de la bomba de protones, por diagnóstico de gastritis a Helicobacter pylori, después de biopsia gástrica realizada durante una videoendoscopía digestiva alta. Se desconoce su historia familiar porque es hijo adoptivo. Al examen físico el paciente estaba adelgazado, sin tumoración a nivel de cuello; presentaba genitales prepuberales. Como el paciente continuó con vómitos cíclicos recurrentes, siguieron exámenes complementarios donde se constató en 2 oportunidades hipercalcemia (13,2-13,6 mg/dl), acompañada de hipofosfatemia (2,7 mg/dl). Con un diagnóstico presuntivo de hiperparatiroidismo primario se realizaron dosajes de laboratorio: calcemia total e iónica elevada (12,1 y 5,6mg/dl respectivamente), fosfatemia baja (2,8 mg/dl), fosfatasa alcalina sérica normal (151 mU/ml), PTH sérica normal (47,1 pg/ml), 25(OH)vitamina D sérica adecuada (22 ng/ml). La ecografía de glándulas tiroides y paratiroides mostró una imagen redondeada hipoecoica, avascular, de 4 mm axial por 4 mm cefalocaudal, por 3 mm ánteroposterior en topografía paratiroidea derecha, planteándose la posibilidad de hipertrofia paratiroidea versus adenopatía. Se realizó estudio de paratiroides por imágenes: centellograma con 99mTc-MIBI y PET-CT con 18F-colina, pero no se constató captación anormal. Se realizaron nuevos estudios de laboratorio: en orina de 24 horas el calcio era de 19 mg, el cociente calcio/creatinina urinaria 0,03 mg/mg, la reabsorción tubular de fósforo normal (82%) y el cociente de las tasas de depuración de calcio y creatinina muy bajo (0,00046). El CTX sérico era bajo. El diagnóstico clínico fue de hipercalcemia hipocalciúrica; ante la falta de antecedentes familiares, se realizó un estudio de posibles mutaciones puntuales en el gen del receptor de calcio (CaSR), hallándose la presencia en heterocigosis de la mutación p.Arg185Gln (p.R185Q) en la posición 554 (c.554G>A) del exón 4 del gene CaSR. Esto implica el cambio de una arginina por glutamina en el codón 185 de la proteína, y confirma el origen genético de la hipercalcemia hipocalciúrica en nuestro paciente. La edad ósea era de 12 años, y se indicó un tratamiento con testosterona i.m. a bajas dosis para acelerar el desarrollo puberal; luego de 4 aplicaciones mensuales su talla se ha incrementado en 4 cm y su peso en 3 kg. Una aplicación subcutánea de denosumab (60 mg) no controló la hipercalcemia. Continuó por un año con hipoorexia y un episodio de vómitos por semana, pero actualmente tiene buen apetito y excelente tolerancia digestiva. Se le ha prescripto cinacalcet oral (AU)

A 12-year-old patient who consulted for recurrent vomiting associated with headaches, with several episodes for 7 months, and low body weight. The patient had previously received treatment with antibiotics and proton pump inhibitors, due to gastritis with Helicobacter pylori, after gastric biopsy performed during videoendoscopy. His family history is unknown because he is an adopted son. At physical examination the patient was thin, without neck tumor; he had prepubertal genitalia. As he patient continued with recurrent vomiting, he was admitted for further evaluation. Laboratory studies revealed hypercalcemia (13.2-13.6 mg/dl), accompanied by hypophosphatemia (2.7 mg/dl). With a presumptive diagnosis of primary hyperparathyroidism, complementary determinations were performed: total and high total and ionized serum calcium (12.1 and 5.6 mg/dl, respectively), normal serum alkaline phosphatase (151 mU/ml), and PTH (47.1 pg/ml), and normal serum 25(OH) vitamin D (32 ng/ml). The ultrasonography of thyroid and parathyroid glands showed a rounded hypoechoic, avascular image, 4 mm in diameter in the lower right parathyroid topography. A parathyroid imaging studies were performed: scintigraphy with 99mTc-MIBI and PET-CT with 18F-choline, but no abnormal uptake was observed. New laboratory studies were carried out: in 24-hour urine the calcium was 19 mg, the urinary calcium/creatinine ratio was 0.03 mg/mg, the tubular reabsorption of phosphorus was normal (82%) and the ratio of clearances rates of calcium and creatinine very low (0.00046). Serum CTX was low. The clinical diagnosis was hypocalciuric hypercalcemia; in the absence of a family history, a study of possible point mutations in the calcium receptor gene (CaSR) was carried out; there was a heterozygous mutation: p.Arg185Gln (p.R185Q) at position 554 (c.554G)>A) of exon 4 of the CaSR gene. This involves the exchange of an arginine for glutamine at codon 185 of the protein, and confirms the genetic origin of the hypocalciuric hypercalcemia in our patient. Bone age was 12 years, and a treatment with testosterone i.m. at low doses to accelerate pubertal development was started; after 4 monthly applications height has increased by 4 cm and weight by 3 kg. Loss of appetite and a weekly episode of postprandial vomiting continued during one yeas, but now his appetite is normal and vomiting has subsided. A subcutaneous application of denosumab (60 mg) did not control hypercalcemia. He has been prescribed oral cinacalcet (AU)