Association between chronic lymphocytic thyroiditis and papillary thyroid carcinoma: a retrospective study in surgical specimens / Asociación entre tiroiditis linfocítica crónica y cáncer papilar de tiroides: estudio retrospectivo de especímenes quirúrgicos

INTRODUCTION: The hypothesis of an association between papillary thyroid carcinoma (PTC) and chronic lymphocytic thyroiditis (CLT) continues to generate debate. Retrospective studies suggest that there is a greater probability of diagnosing a PTC in surgical specimens with CLT; however, prospective studies suggest that there is no true increase in risk. METHODS: An analytical, cross-section measurement and retrospective study was carried out considering gender, age and diagnosis of CLT and PTC in surgical specimens. A binary logistic regression model was proposed to predict the probability of carrying out the diagnosis of PTC based on the diagnosis of CLT, gender and age. RESULTS: The study population consisted of 1136 patients, 1047 (92.2%) women and 89 (7.8%) men, with an average age of 47.5±14.3 years. The prevalence of CLT and PTC was 14.9% and 16.1% respectively. Coexistence between PTC and CLT was found in 44 patients, corresponding to 3.9% of the population. Our logistic regression model suggests that the probability of diagnosing PTC in surgical specimens of male patients under 40 years old and with CLT is 53.8%. CONCLUSIONS: We suggest that there is a greater probability of diagnosing PTC in surgical specimens with confirmatory histological data for CLT; in addition, in males under 40 years old this probability increases

INTRODUCCIÓN: La hipótesis que sugiere una asociación entre el cáncer papilar de tiroides (PTC, por sus siglas en inglés) y la tiroiditis linfocítica crónica (CLT, por sus siglas en inglés) sigue generando debate. Los estudios retrospectivos sugieren que existe una mayor probabilidad de realizar un diagnóstico de PTC en las muestras quirúrgicas de CLT. Los estudios prospectivos sugieren que no existe un incremento real del riesgo. MÉTODOS: Se realizó un estudio analítico de medición transversal y temporalidad retrospectiva en cuanto a sexo, edad, diagnóstico de CLT y espécimen quirúrgico de PTC. Se propuso un modelo de regresión logística binaria para predecir la probabilidad de realizarse un diagnóstico de PTC basado en el diagnóstico de CLT, sexo y edad. RESULTADOS: La población de estudio consistió en 1.136 pacientes, 1.047 mujeres (92,2%) y 89 varones (7,8%), con una edad media de 47,5 ± 14,3 años. La prevalencia de CLT y PTC fue del 14,9% y 16,1%, respectivamente. La coexistencia de PTC y CLT fue encontrada en 44 pacientes, correspondiente al 3,9% de la población. Nuestro modelo de regresión logística sugiere que la probabilidad de realizar el diagnóstico de PTC en muestras quirúrgicas de pacientes varones con edades inferiores a 40 años y con CLT es del 53,8%. CONCLUSIONES: Sugerimos que existe una mayor probabilidad de diagnosticar PTC en muestras quirúrgicas con datos histológicos confirmatorios de CLT; además, esta probabilidad puede modificarse sobre la base de sexo masculino y edad superior a 40 años

Geometric mixing.

Mixing fluids often involves a periodic action, like stirring one's tea. But reciprocating motions in fluids at low Reynolds number, in Stokes flows where inertia is negligible, lead to periodic cycles of mixing and unmixing, because the physics, molecular diffusion excepted, is time reversible. So how can fluid be mixed in such circumstances? The answer involves a geometric phase. Geometric phases are found everywhere in physics as anholonomies, where after a closed circuit in the parameters, some system variables do not return to their original values. We discuss the geometric phase in fluid mixing: geometric mixing. This article is part of the theme issue 'Stokes at 200 (part 2)'.

Association between chronic lymphocytic thyroiditis and papillary thyroid carcinoma: A retrospective study in surgical specimens.

INTRODUCTION: The hypothesis of an association between papillary thyroid carcinoma (PTC) and chronic lymphocytic thyroiditis (CLT) continues to generate debate. Retrospective studies suggest that there is a greater probability of diagnosing a PTC in surgical specimens with CLT; however, prospective studies suggest that there is no true increase in risk. METHODS: An analytical, cross-section measurement and retrospective study was carried out considering gender, age and diagnosis of CLT and PTC in surgical specimens. A binary logistic regression model was proposed to predict the probability of carrying out the diagnosis of PTC based on the diagnosis of CLT, gender and age. RESULTS: The study population consisted of 1136 patients, 1047 (92.2%) women and 89 (7.8%) men, with an average age of 47.5±14.3 years. The prevalence of CLT and PTC was 14.9% and 16.1% respectively. Coexistence between PTC and CLT was found in 44 patients, corresponding to 3.9% of the population. Our logistic regression model suggests that the probability of diagnosing PTC in surgical specimens of male patients under 40 years old and with CLT is 53.8%. CONCLUSIONS: We suggest that there is a greater probability of diagnosing PTC in surgical specimens with confirmatory histological data for CLT; in addition, in males under 40 years old this probability increases.

Light Control of Localized Photobioconvection.

Microorganismal motility is often characterized by complex responses to environmental physico-chemical stimuli. Although the biological basis of these responses is often not well understood, their exploitation already promises novel avenues to directly control the motion of living active matter at both the individual and collective level. Here we leverage the phototactic ability of the model microalga Chlamydomonas reinhardtii to precisely control the timing and position of localized cell photoaccumulation, leading to the controlled development of isolated bioconvective plumes. This novel form of photobioconvection allows a precise, fast, and reconfigurable control of the spatiotemporal dynamics of the instability and the ensuing global recirculation, which can be activated and stopped in real time. A simple continuum model accounts for the phototactic response of the suspension and demonstrates how the spatiotemporal dynamics of the illumination field can be used as a simple external switch to produce efficient bio mixing.

Turbulence induces clustering and segregation of non-motile, buoyancy-regulating phytoplankton.

Turbulence plays a major role in shaping marine community structure as it affects organism dispersal and guides fundamental ecological interactions. Below oceanographic mesoscale dynamics, turbulence also impinges on subtle physical-biological coupling at the single cell level, setting a sea of chemical gradients and determining microbial interactions with profound effects on scales much larger than the organisms themselves. It has been only recently that we have started to disentangle details of this coupling for swimming microorganisms. However, for non-motile species, which comprise some of the most abundant phytoplankton groups on Earth, a similar level of mechanistic understanding is still missing. Here, we explore by means of extensive numerical simulations the interplay between buoyancy regulation in non-motile phytoplankton and cellular responses to turbulent mechanical cues. Using a minimal mechano-response model, we show how such a mechanism would contribute to spatial heterogeneity and affect vertical fluxes and trigger community segregation.

Collective sinking promotes selective cell pairing in planktonic pennate diatoms.

Finding a partner in an inherently unsteady 3-dimensional system, such as the planktonic marine environment, is a difficult task for nonswimming organisms with poor control over their orientation. We experimentally investigate the process of cell pairing in pennate marine diatoms and present field evidence of its occurrence in the ocean. We describe the mechanism as a 3-step process in which pennate diatoms (i) vertically reorient while sinking from surface turbulent waters to a more stable environment (i.e., under the seasonal pycnocline), (ii) segregate from incompatible partners (e.g., dead or different sized cells), and (iii) pair with other partners as a result of the hydrodynamic instabilities generated by collective cell sinking. This is, eminently, a cell abundance-dependent process, therefore being more effective when population sinking is synchronized. We suggest that this selective process, enabling matching of size-compatible healthy partners, could be fundamental in understanding sexual reproduction in pennate diatoms.

Phototaxis beyond turning: persistent accumulation and response acclimation of the microalga Chlamydomonas reinhardtii.

Phototaxis is an important reaction to light displayed by a wide range of motile microorganisms. Flagellated eukaryotic microalgae in particular, like the model organism Chlamydomonas reinhardtii, steer either towards or away from light by a rapid and precisely timed modulation of their flagellar activity. Cell steering, however, is only the beginning of a much longer process which ultimately allows cells to determine their light exposure history. This process is not well understood. Here we present a first quantitative study of the long timescale phototactic motility of Chlamydomonas at both single cell and population levels. Our results reveal that the phototactic strategy adopted by these microorganisms leads to an efficient exposure to light, and that the phototactic response is modulated over typical timescales of tens of seconds. The adaptation dynamics for phototaxis and chlorophyll fluorescence show a striking quantitative agreement, suggesting that photosynthesis controls quantitatively how cells navigate a light field.

Advection by ocean currents modifies phytoplankton size structure.

Advection by ocean currents modifies phytoplankton size structure at small scales (1-10 cm) by aggregating cells in different regions of the flow depending on their size. This effect is caused by the inertia of the cells relative to the displaced fluid. It is considered that, at larger scales (greater than or equal to 1 km), biological processes regulate the heterogeneity in size structure. Here, we provide observational evidence of heterogeneity in phytoplankton size structure driven by ocean currents at relatively large scales (1-10 km). Our results reveal changes in the phytoplankton size distribution associated with the coastal circulation patterns. A numerical model that incorporates the inertial properties of phytoplankton confirms the role of advection on the distribution of phytoplankton according to their size except in areas with enhanced nutrient inputs where phytoplankton dynamics is ruled by other processes. The observed preferential concentration mechanism has important ecological consequences that range from the phytoplankton level to the whole ecosystem.

Geometric Mixing, Peristalsis, and the Geometric Phase of the Stomach.

Mixing fluid in a container at low Reynolds number--in an inertialess environment--is not a trivial task. Reciprocating motions merely lead to cycles of mixing and unmixing, so continuous rotation, as used in many technological applications, would appear to be necessary. However, there is another solution: movement of the walls in a cyclical fashion to introduce a geometric phase. We show using journal-bearing flow as a model that such geometric mixing is a general tool for using deformable boundaries that return to the same position to mix fluid at low Reynolds number. We then simulate a biological example: we show that mixing in the stomach functions because of the "belly phase," peristaltic movement of the walls in a cyclical fashion introduces a geometric phase that avoids unmixing.

Microscale patches of nonmotile phytoplankton.

Phytoplankton cells have evolved sophisticated strategies for actively responding to environmental signals, most notably to mechanical stresses of hydrodynamic origin. A largely unanswered question, however, is the significance of these cellular responses for the largely heterogeneous spatial distribution of cells found in the oceans. Motivated by the physiological regulation of buoyancy prevalent in nonmotile phytoplankton species, we solve here a minimal model for "active" sinking that incorporates these cellular responses. Within this model, we show how buoyancy regulation leads to intense patchiness for nonmotile species as compared to passive tracers, resulting in important variations in settling speeds and, as a consequence, determining escape rates to the deep ocean.

Fístula liquórica como diagnóstico diferencial de rinite / Cerebrospinal fluid fistula as differential diagnosis from rhinitis

A rinite alérgica representa uma das doenças mais freqüentes na prática diária do alergologista, otorrinolaringologista e do clínico, caracterizando-se clinicamente por espirros mültiplos, coriza hialina, prurido e obstruçäo nasais. A fístula liquórica, mesmo sendo pouco freqüente, é diagnóstico diferencial importante das rinites. Nesta revisäo procuramos abordar, de forma sucinta, características clínicas, fisiopatologia, diagnóstico laboratorial e tratamento da entidade.