A prospective evaluation of plasma phospholipid fatty acids and breast cancer risk in the EPIC study.

BACKGROUND: Intakes of specific fatty acids have been postulated to impact breast cancer risk but epidemiological data based on dietary questionnaires remain conflicting. MATERIALS AND METHODS: We assessed the association between plasma phospholipid fatty acids and breast cancer risk in a case-control study nested within the European Prospective Investigation into Cancer and Nutrition study. Sixty fatty acids were measured by gas chromatography in pre-diagnostic plasma phospholipids from 2982 incident breast cancer cases matched to 2982 controls. Conditional logistic regression models were used to estimate relative risk of breast cancer by fatty acid level. The false discovery rate (q values) was computed to control for multiple comparisons. Subgroup analyses were carried out by estrogen receptor (ER) and progesterone receptor expression in the tumours. RESULTS: A high level of palmitoleic acid [odds ratio (OR) for the highest quartile compared with the lowest OR (Q4-Q1) 1.37; 95% confidence interval (CI), 1.14-1.64; P for trend = 0.0001, q value = 0.004] as well as a high desaturation index (DI16) (16:1n-7/16:0) [OR (Q4-Q1), 1.28; 95% C, 1.07-1.54; P for trend = 0.002, q value = 0.037], as biomarkers of de novo lipogenesis, were significantly associated with increased risk of breast cancer. Levels of industrial trans-fatty acids were positively associated with ER-negative tumours [OR for the highest tertile compared with the lowest (T3-T1)=2.01; 95% CI, 1.03-3.90; P for trend = 0.047], whereas no association was found for ER-positive tumours (P-heterogeneity =0.01). No significant association was found between n-3 polyunsaturated fatty acids and breast cancer risk, overall or by hormonal receptor. CONCLUSION: These findings suggest that increased de novo lipogenesis, acting through increased synthesis of palmitoleic acid, could be a relevant metabolic pathway for breast tumourigenesis. Dietary trans-fatty acids derived from industrial processes may specifically increase ER-negative breast cancer risk.

Bortezomib-induced peripheral neurotoxicity in human multiple myeloma-bearing mice.

The proteasome inhibitor bortezomib is an antineoplastic drug mainly used for the treatment of multiple myeloma (MM). Despite its effectiveness, bortezomib clinical use is often limited by the onset of peripheral neuropathy (BiPN). To better understand the mechanisms of BiPN several rat and mice models have been proposed, but no studies in MM-bearing animals allowing to test the antitumor activity of the selected schedules and the role of MM by itself in peripheral nervous system damage have been reported to date. Here, we carried out a study using immunodeficient C.B-17/Prkdcscid (SCID) mice injected with RPMI8266 human MM cells and treated with bortezomib 1 mg/kg once a week for five weeks. Animals were assessed with neurophysiological, behavioral and pathological methods and tumor volume measurement was performed along the study. At the end of the study BiPN was evident in bortezomib-treated animals, and this neurotoxic effect was evident using a schedule able to effectively prevent tumor growth. However, neurophysiological and pathological evidence of MM induced peripheral nervous system damage was also reported. This model based on MM-bearing animals is more reliable in the reproduction of the clinical setting and it is, therefore, more suitable than the previously reported models of BiPN to study its pathogenesis. Moreover, it represents an optimal model to test the efficacy of neuroprotective agents and at the same time their non-interference with bortezomib antineoplastic activity.

Insulin-like growth factor I and risk of epithelial invasive ovarian cancer by tumour characteristics: results from the EPIC cohort.

BACKGROUND: Prospective studies on insulin-like growth factor I (IGF-I) and epithelial ovarian cancer (EOC) risk are inconclusive. Data suggest risk associations vary by tumour characteristics. METHODS: We conducted a nested case-control study in the European Prospective Investigation into Cancer and Nutrition (EPIC) to evaluate IGF-I concentrations and EOC risk by tumour characteristics (n=565 cases). Multivariable conditional logistic regression models were used to estimate associations. RESULTS: We observed no association between IGF-I and EOC overall or by tumour characteristics. CONCLUSIONS: In the largest prospective study to date was no association between IGF-I and EOC risk. Pre-diagnostic serum IGF-I concentrations may not influence EOC risk.

Dietary intake of acrylamide and endometrial cancer risk in the European Prospective Investigation into Cancer and Nutrition cohort.

BACKGROUND: Three prospective studies have evaluated the association between dietary acrylamide intake and endometrial cancer (EC) risk with inconsistent results. The objective of this study was to evaluate the association between acrylamide intake and EC risk: for overall EC, for type-I EC, and in never smokers and never users of oral contraceptives (OCs). Smoking is a source of acrylamide, and OC use is a protective factor for EC risk. METHODS: Cox regression was used to estimate hazard ratios (HRs) for the association between acrylamide intake and EC risk in the European Prospective Investigation into Cancer and Nutrition (EPIC) cohort. Acrylamide intake was estimated from the EU acrylamide monitoring database, which was matched with EPIC questionnaire-based food consumption data. Acrylamide intake was energy adjusted using the residual method. RESULTS: No associations were observed between acrylamide intake and overall EC (n=1382) or type-I EC risk (n=627). We observed increasing relative risks for type-I EC with increasing acrylamide intake among women who both never smoked and were non-users of OCs (HRQ5vsQ1: 1.97, 95% CI: 1.08-3.62; likelihood ratio test (LRT) P-value: 0.01, n=203). CONCLUSIONS: Dietary intake of acrylamide was not associated with overall or type-I EC risk; however, positive associations with type I were observed in women who were both non-users of OCs and never smokers.

Circulating prolactin and breast cancer risk among pre- and postmenopausal women in the EPIC cohort.

BACKGROUND: Experimental and epidemiological evidence suggests that prolactin might play a role in the etiology of breast cancer. We analyzed the relationship of prediagnostic circulating prolactin levels with the risk of breast cancer by menopausal status, use of postmenopausal hormone replacement therapy (HRT) at blood donation, and by estrogen and progesterone receptor status of the breast tumors. PATIENTS AND METHODS: Conditional logistic regression was used to analyze the data from a case-control study nested within the prospective European EPIC cohort, including 2250 invasive breast cancer and their matched control subjects. RESULTS: Statistically significant heterogeneity in the association of prolactin levels with breast cancer risk between women who were either pre- or postmenopausal at the time of blood donation was observed (Phet = 0.04). Higher serum levels of prolactin were associated with significant increase in the risk of breast cancer among postmenopausal women [odds ratio (OR)Q4-Q1 = 1.29 (95% confidence interval, CI, 1.05-1.58), Ptrend = 0.09]; however, this increase in risk seemed to be confined to women who used postmenopausal HRT at blood donation [ORQ4-Q1 = 1.45 (95% CI 1.08-1.95), Ptrend = 0.01], whereas no statistically significant association was found for the non-users of HRT [ORQ4-Q1 = 1.11 (95%CI 0.83-1.49), Ptrend = 0.80] (Phet = 0.08). Among premenopausal women, a statistically non-significant inverse association was observed [ORQ4-Q1 = 0.70 (95% CI 0.48-1.03), Ptrend = 0.16]. There was no heterogeneity in the prolactin-breast cancer association by hormone receptor status of the tumor. CONCLUSION: Our study indicates that higher circulating levels of prolactin among the postmenopausal HRT users at baseline may be associated with increased breast cancer risk.

Short-term dynamics of culturable bacteria in a soil amended with biotransformed dry olive residue.

Dry olive residue (DOR) transformation by wood decomposing basidiomycetes (e.g. Coriolopsis floccosa) is a possible strategy for eliminating the liabilities related to the use of olive oil industry waste as an organic soil amendment. The effects of organic fertilization with DOR on the culturable soil microbiota are largely unknown. Therefore, the objectives of this study were to measure the short-term effects of DOR and C. floccosa-transformed DOR on the culturable bacterial soil community, while at the same time documenting the bacterial diversity of an agronomic soil in the southeastern Iberian Peninsula. The control soil was compared with the same soil treated with DOR and with C. floccosa-transformed DOR for 0, 30 and 60 days. Impact was measured from total viable cells and CFU counts, as well as the isolation and characterization of 900 strains by fatty acid methyl ester profiles and 16S rRNA partial sequencing. The bacterial diversity was distributed between Actinobacteria, Alphaproteobacteria, Gammaproteobacteria, Betaproteobacteria, Bacilli, Sphingobacteria and Cytophagia. Analysis of the treatments and controls demonstrated that soil amendment with untransformed DOR produced important changes in bacterial density and diversity. However, when C. floccosa-transformed DOR was applied, bacterial proliferation was observed but bacterial diversity was less affected, and the distribution of microorganisms was more similar to the unamended soil.

Neuroanatomía de las decisiones financieras / Neuroanatomy of financial decisions

Introducción: La neuroeconomía es una nueva disciplina que estudia los procesos cerebrales de toma de decisiones, fundamentalmente económicas y que ha adquirido un importante avance en los últimos años con el desarrollo de las modernas técnicas de neuroimagen, como la resonancia magnética cerebral funcional. Este artículo realiza una revisión de la bibliografía sobre los diferentes mecanismos neurológicos implicados en la toma de decisiones financieras, las estructuras cerebrales involucradas y las enfermedades que pueden afectarlos. Fuentes: Realizamos una revisión no sistemática de la literatura, tanto en fuentes de información primaria (PubMed) como de información secundaria (Tripdatabase y Cochrane Library). También se utilizó bibliografía cedida por la Asociación Española de Neuroeconomía. Desarrollo:Los sistemas de recompensa cerebral y de aversión a la pérdida suponen un equilibrio que hará que optemos por una u otra decisión. En este equilibrio en el que la dopamina desempeña un papel primordial, se han visto involucradas varias estructuras cerebrales como la amígdala, la ínsula, la corteza prefrontal medial, las cortezas cinguladas anterior y posterior, el núcleo accumbens y el área tegmental ventral. Su alteración supone la producción de conductas financieras inapropiadas como tienen lugar en enfermedades tan frecuentes como la depresión, la manía, el alcoholismo, la ludopatía o diversos trastornos del control de impulsos.Conclusiones: Los neurólogos deberíamos definir nuestro papel en esta ciencia pluridisciplinar, dada la posición de privilegio de nuestra especialidad para estudiar el funcionamiento cerebral, y al más que posible crecimiento que se espera que la neuroeconomía adquiera en un futuro cercano (AU)

Introduction: Neuroeconomics is a new science that studies the brain processes involved in taking decisions, particularly related to economy and it has experienced an important advancein the recent years due to the development of the new neuroimaging techniques, basically functional magnetic resonance imaging. The aim of this paper it to carry out a review of theliterature on the different neurological mechanisms involved in taking financial decisions, the concerned brain structures and the diseases that can affect them. Sources: We made a non systematic review of the literature in primary (PubMed) and secondary(Tripdatabase and Cochrane Library) bibliographic databases. We also used bibliography given by the Asociación Espa˜nola de Neuroeconomía.Development: Brain reward and loss aversion systems suppose a balance that makes us take one or another decision. Dopamine plays an important role on it and several brain structureshave been involved in this balance such as the amygdale, the insula, the medial prefrontal cortex, the anterior and posterior cingulated cortex, the accumbens nucleus and the ventraltegmental area. The alteration of this balance may produce inappropriate financial behaviors what may occur in common diseases including depression, mania, alcoholism, gambling andseveral impulse control disorders.Conclusions: Neurologists should define our role in this interdisciplinary field due to the privileged position of our specialty to study how the brain works and due to the potential growingof this science in the near future (AU)

Neuroanatomy of financial decisions.

INTRODUCTION: Neuroeconomics is a new science that studies the brain processes involved in taking decisions, particularly related to economy and it has experienced an important advance in the recent years due to the development of the new neuroimaging techniques, basically functional magnetic resonance imaging. The aim of this paper it to carry out a review of the literature on the different neurological mechanisms involved in taking financial decisions, the concerned brain structures and the diseases that can affect them. SOURCES: We made a non systematic review of the literature in primary (PubMed) and secondary (Tripdatabase and Cochrane Library) bibliographic databases. We also used bibliography given by the Asociación Española de Neuroeconomía. DEVELOPMENT: Brain reward and loss aversion systems suppose a balance that makes us take one or another decision. Dopamine plays an important role on it and several brain structures have been involved in this balance such as the amygdale, the insula, the medial prefrontal cortex, the anterior and posterior cingulated cortex, the accumbens nucleus and the ventral tegmental area. The alteration of this balance may produce inappropriate financial behaviors what may occur in common diseases including depression, mania, alcoholism, gambling and several impulse control disorders. CONCLUSIONS: Neurologists should define our role in this interdisciplinary field due to the privileged position of our specialty to study how the brain works and due to the potential growing of this science in the near future.

Occurrence of plant growth regulators in Psilotum nudum.

The endogenous content of the auxin indole-3-acetic acid (IAA), the cytokinins trans-zeatin (tZ), trans-zeatin riboside (tZR), dihydrozeatin (DHZ), dihydrozeatin riboside (DHZR), isopentenyladenine (iP) and isopentenyladenosine (iPR), the gibberellins GA(1), GA(3), GA(4), GA(7), GA(9) and GA(20) in the rhizome and aerial shoots during and after sporogenesis were measured by high-performance liquid chromatography-tandem mass spectrometry in the fern Psilotum nudum. The present study shows, for the first time, the presence of the auxin IAA, the cytokinins tZR, DHZR and iP, and the gibberellins GA(4), GA(9) and GA(20) in the rhizome and aerial shoots of this species and suggests a possible role of gibberellins in the evolution of ferns.

Pacientes pediátricos en insuficiencia hepática y pasibles de trasplante: Correlación del tiempo de protrombina y Razón Internacional Normatizada (RIN) entre dos combinaciones de reactivos e instrumentos de medición / Pediatric patients with liver failure who are candidates for transplantation: correlation of prothrombin time and international normalized ratio (INR) in two combinations of reagents and measurement instruments

El objetivo de este trabajo es correlacionar el tiempo de protrombina y RIN en dos combinaciones de reactivos e instrumentos de medición en muestras de pacientes pediátricos con insuficiencia hepática asistidos en el Hospital de Pediatría Juan P. Garrahan y pasibles de trasplante. Se estudiaron 62 muestras de sangre obtenidas de pacientes, con presencia de patología hepática, definida con evidencia bioquímica de injuria hepática. Se utilizaron 2 (dos) analizadores, un coagulómetro BCT de detección foto-óptica y un Sta Compact de detección electromagnética. Para el analizador BCT se utilizó el reactivo Thromborel S, en el Sta Compact el Sta Neoplastine. Se trabajó con el ISI correspondiente a cada Reactivo /Instrumento. El análisis estadístico se realizó con el programa informático Stata 9.0, aplicando los tests estadísticos de coeficiente de correlación (rho) y el intervalo de confianza 95%; se determino la ecuación de la recta, para cada caso, se determino la equivalencia clínica a través del EP evaluator. Nuestra conclusión es que en los pacientes con insuficiencia hepática, se halló mejor correlación estadística y clínica para el TP%, debido a que se independiza del Tiempo (seg.) y de la calidad de la tromboplastina (diferentes concentraciones de factor tisular). Según nuestros resultados el sistema ISI/RIN, no seria válido para aplicarlo a pacientes con falla hepática y pasible de trasplante. Una de las causas es la falta de un reactivo de Tromboplastina calibrado con plasmas de pacientes con insuficiencia hepática, ya que para el cálculo del ISI, se usan plasmas de pacientes con terapia ACO (AU)

The objective of this study was to correlate prothrombin time (PT) and INR in two combinations of reagents and measurement instruments samples of pediatric patients with liver failure seen at the Hospital de Pediatría Juan P. Garrahan and who are candidates for liver transplantation. Sixtytwo blood samples were studied obtained from patients with liver pathology defined by biochemical evidence of liver injury. Two analyzers were used: a BCT coagulometer with photo-optical clot detection and a Sta Compact with an electromagnetic detection system. For the BCT analyzer Thromborel S was used and in the Sta Compact Sta Neoplastine was used. The ISI corresponding to each Reagent /Instrument was used. Statistical analysis was done with Stata 9.0, with correlation coefficient (rho) and a 95% confidence interval; for each case the equation of the straight line was determined. Clinical equivalence was determined through the EP evaluator. Our conclusion is that in patients with liver failure a better statistical and clinical correlation was found for PT%, as it is independent of Time (sec.) and of thromboplastin quality (different concentrations of tissue factor). According to our results, the ISI/INR system is not adequate in patients with liver failure who are candidates for liver transplantation. One of the reasons is that we lack a thromboplastin reagent that is calibrated against plasma of patients with liver failure, as for the ISI calculation plasma of patients with OAC therapy is used (AU)

A possible novel Francisella genomic species isolated from blood and urine of a patient with severe illness.

Two identical isolates were recovered in pure culture from the blood and urine of a patient suffering from severe septicaemia associated with obstructive pyelonephritis secondary to lithotripsy. Preliminary phenotypic and genotypic characterizations based on serological, biochemical and sequence analyses following PCR amplification of selected gene regions indicate that this organism represents a potential new Francisella genomic species.

Neuropathological changes in the peripheral nervous system and spinal cord in a transgenic mouse model of Niemann-Pick disease type A.

OBJECTIVE: Type A Niemann-Pick is a severe neurological disease, caused by a mutation of the gene of acid sphingomyelinase (ASM) and reduced enzyme activity. Some studies reported neuropathological changes occurring in the central nervous system of ASM deficient transgenic (ASMKO) mice, while a detailed study on the peripheral nervous system (PNS) at different ages is currently lacking. The aim of our study was to examine the pathological changes occurring in the PNS and in the spinal cord in an AMSKO model of Niemann-Pick disease (NPD) Type A. MATERIAL AND METHOD: Dorsal root ganglia (DRG), peripheral nerves and spinal cord specimens were obtained from ASMKO mice and age-matched wild type animals (age range = 1-7 months). They were observed at the light and electron microscope. Behavioral testing was performed to assess motor coordination and reactivity. Fluoro-Jade B was used as a high affinity fluorescent marker for degenerating neurons. RESULTS: Typical NPD cytoplasmic inclusions were observed in DRG neurons and satellite cells, in peripheral nerve Schwann cells, in spinal cord neurons and in endothelial cells. All these inclusions were present from the age of 1 month and increased with aging. By Fluoro-Jade B staining we demonstrated the occurrence of neuronal degeneration starting from 5 months of age. CONCLUSION: Despite the fact that a definite diagnosis of NPD Type A depends on enzymatic assays and/or molecular analysis, morphological investigation remains an important diagnostic procedure. Well-defined and complete neuropathological information about the ASMKO mouse model, inclusive of PNS examination, may be crucial in the pre-clinical evaluation of new therapies.

Targeting cancer and neuropathy with histone deacetylase inhibitors: two birds with one stone?

Histone deacetylase inhibitors (HDACi) belong to a novel class of drugs able to act on the epigenome, indirectly remodeling the spatial conformation of the chromatin: by increasing histone acetylation these drugs ultimately promote the detachment of the DNA from the nucleosome octamer, therefore allowing the access of transcription factors to the double helix. Such a mechanism of action is of particular interest in the field of cancer treatment, considering the reactivation of silenced tumor suppressor genes as an important target at which aiming; indeed, it is currently believed that dysregulation of the epigenome plays a major role in cancer. Interestingly, some of the compounds belonging to the HDACi family have also additional therapeutic properties, as in the case of valproate that may ameliorate neuropathic pain in animal models and in patients. Conceivably, this is a remarkable observation, since peripheral neuropathy is a potentially severe side effect of several classes of anticancer agents, such as platinum-derived drugs, antitubulins or protesome inhibitors, limiting an effective treatment of the underlying cancer. Based on these data, in this review we will argue that, with respect to other nowadays available anticancer agents, HDACi might offer the advantage not only to target the neoplastic disorder, but also to prevent peripheral neuropathies, possibly displaying a complementary mechanism of action.

Condiloma acuminado perianal gigante complicado / Perianal complicated giant condyloma acuminatum

No disponible

Human platelets express the synaptic markers VGLUT1 and 2 and release glutamate following aggregation.

Vesicular glutamate transporters (VGLUTs) are involved in storing glutamate for secretion at the level of glutamatergic axon terminals, and for this reason they have been extensively used as markers to identify glutamate-releasing cells. Platelets have been considered as a suitable model for studying glutamatergic dysfunction because they perform glutamate uptake and express both external transporters, and NMDA-like receptors. Here, we show that platelets express the pre-synaptic markers VGLUT1 and VGLUT2 and release glutamate following aggregation, implying a possible contributory role in the pathophysiology of stroke, migraine, and other excitotoxic disorders.

Gibberellins and antheridiogen on sex in Blechnum spicant L.

The role of gibberellins (GAs) in determining sex in the gametophyte of the fern Blechnum spicant L. was studied through (a) the effect of exogenous GA(4+7) and GA3 (b) quantitation of the endogenous levels of GA1, GA3, GA4, GA7, GA9, and GA20 in male and female gametophytes, and (c) the effect of flurprimidol, a GAs biosynthesis inhibitor of the steps of oxidation of ent-kaureno to ent-kaurenoic acid. Our results show that GA(4+7) had a slight effect of inducing either male or female sexual organs, antheridia and archegonia, respectively. The endogenous GAs content was not significantly different between sexes, but the GA4, GA7, and GA20 levels were raised above those of the other GAs in both sexes. Neither antheridiogen biosynthesis nor antheridia formation was inhibited by flurprimidol. Gametophytes regenerated from homogenized mature gametophytes (HG) show a different physiological behavior than spore-derived gametophytes. In the first case, gametophytes are males and synthesize antheridiogen before they attain maturity, in contrast to what occurs in spore-derived gametophytes which are females and synthesize antheridiogen when mature.

Empalamiento transabdominal / Transabdominal impalament

No disponible

Empleo de la oxigenoterapia mediante cámara hiperbárica en cirugía oral y maxilofacial / The use of oxygen therapy by means of the hyperbaric chamber in oral and maxillofacial surgery

La oxigenoterapia hiperbárica (OHB) es una modalidad de terapéutica física que se fundamenta en la obtención de presiones parciales de oxígeno elevadas, al respirar oxígeno puro en el interior de una cámara a una presión superior a la atmosférica. El objetivo de esta revisión es clarificar los mecanismos de acción y los efectosde esta terapéutica física, los problemas que puede plantear y sobre todo las indicaciones actuales.En cirugía oral y maxilofacial, la OHB se utiliza como tratamiento complementario en procesos de osteítis y osteomielitis maxilo-mandibular, en infecciones necrotizantes de partes blandas (a nivel cervical, periodontal, gingival,…), en la prevención (muy importante) y el tratamiento de la osteradionecrosis, en los retrasos de cicatrización (de fracturas, deimplantes dentales, de injertos/colgajos de difícil viabilidad), en la rehabilitación implantológica de pacientes oncológicos irradiados.Es preciso utilizar los protocolos establecidos y generar estudios que sostengan científicamente su utilización; de este modo se podría paliar la pocaconsistencia de los estudios publicados que hemos encontrado

Hyperbaric oxygen therapy (HBO) is a physical therapeuticmodality based on obtaining high partial pressures of oxygen, on breathing pure oxygen inside a chamber at a pressure that is greater than that of the atmosphere.The object of this revision is to clarify the action mechanisms and the effects of the physical therapy, the problems that may arise and more especially the current indications for its use.In oral and maxillofacial surgery, HBO is used as complementary treatment for maxillo-mandibular osteitis and osteomyelitis, for necrotizing infections of soft tissue (on a cervical, periodontal, gingival...level), for the prevention (very important) and treatment of osteoradionecrosis, for healing delays (fractures, dental implants, grafts/flaps with difficult viability), for implantological rehabilitationof irradiated oncological patients.It is necessary to use the protocols that have been established and to generate studies that scientifically support its use; in this sense the lack of consistency that we have found is the studies that have been published could be reduced

Exogenous and endogenous growth regulators on apogamy in Dryopteris affinis (Lowe) Fraser-Jenkins sp. affinis.

This work showed for the first time the relationship between the effect of exogenous auxins and gibberellins on apogamy in Dryopteris affinis (Lowe) Fraser-Jenkins sp. affinis and its endogenous contents during early apogamic events. The addition of NAA (0.53 and 5.37 microM) or GA(3) 2.8 microM to an MS solid medium significantly increased apogamous sporophyte formation. BA induced brown callus that regenerated sporophytes in a hormone-free medium. The endogenous contents of GA(1), GA(3), GA(4), GA(7), GA(9) and IAA were determined by GC-MS in gametophytes cultured on MS solid medium, before and during early stages of apogamous embryo development. The accumulation of both GA(9) and IAA before embryo development was evident as high levels of GA(4) in the earliest analysed stage of embryo development and high levels of GA(3) in elongating shoots were found. The role of gibberellins on apogamy was also supported by data showing a decrease in the percentage of gametophytes developing embryos because of the addition of flurprimidol to the culture medium.