Dynamical analysis of mushroom bifurcations: deterministic and stochastic approaches

Treballs Finals de Grau de Matemàtiques, Facultat de Matemàtiques, Universitat de Barcelona, Any: 2023, Director: Àlex Haro i Josep Sardanyés i Cayuela[en] Bifurcation theory has found contemporary applications in synthetic biology, particularly in the field of biosensors [43]. The aim of this thesis is to expand upon the framework presented in the referenced paper, which introduces a model depicting the behavior of mushroom bifurcations. The mushroom bifurcation diagram exhibits four saddle-node bifurcations and involves bistability. Our goal is to develop a comprehensive mathematical formalism that can effectively describe this behavior, both deterministically and stochastically. By doing so, we seek to uncover additional properties regarding the transients exhibited by these biosensors, specifically focusing on optimizing their timer-effect, memory properties, and signaling capabilities. We will introduce stochastic dynamics by considering intrinsic noise in the molecular processes, allowing us to investigate the slowing-down effects in the vicinity of the saddle-nodes and transcritical bifurcations. To conduct this study, we will use three fundamental mathematical tools, which can be regarded as the backbone of our analysis. These mathematical vertebrae include the Lemma of Morse, the Weierstrass Preparation Theorem and, most notably, the Implicit Function Theorem. Through this rigorous analysis, we aim to enhance our understanding of the underlying dynamics of these biosensors and facilitate their further improvement and utilization in various applications

Diagnòstic genètic preimplantacional amb una tècnica ràpida d'hibridació genòmica comparada

En esta tesis doctoral se ha desarrollado una nueva variante de la Hibridación Genómica Comparada (CGH), que reduce drásticamente el tiempo de hibridación. Esta técnica, aplicada al Diagnóstico Genético Preimplantacional, ofrece un análisis completo de todos los cromosomas y permite obtener los resultados mucho más rápido y con la misma eficiencia que con la CGH convencional, de modo que los embriones cromosómicamente normales seleccionados pueden ser transferidos al útero materno en el mismo ciclo de la fecundación in vitro sin tener que criopreservarlos.En aquesta tesi doctoral s'ha desenvolupat una nova variant de la Hibridació Genòmica Comparada (CGH), que redueix dràsticament el temps d'hibridació. Aquesta tècnica, aplicada al Diagnòstic Genètic Preimplantacional, ofereix una anàlisi completa de tots els cromosomes i permet obtenir els resultats molt més ràpid i amb la mateixa eficiència que amb la CGH convencional, de manera que els embrions cromosòmicament normals seleccionats poden ser transferits a l'úter matern en el mateix cicle de la fecundació in vitro sense haver de criopreservar-los

Estudi i diagnòstic d'aneuploïdies en oòcits humans

La disponibilitat de material biològic descartat de cicles de fecundació in vitro (FIV) ha estat molt valuós per a l'estudi d'aneuploïdies en els primers estadis del desenvolupament embrionari. L'estudi citogenètic d'oòcits humans requereix l'anàlisi per separat de l'oòcit en estadi de meiosi ii i el corresponent primer corpuscle polar amb dotació cromosòmica complementària. La hibridació in situ fluorescent i les seves variants, com el cariotipatge espectral, l'encebador in situ o la FISH de centròmers multicolor, han estat molt útils, tot i que requereixen la fixació prèvia de la cèl·lula. Com a alternativa, la hibridació genòmica comparada no requereix la fixació de la cèl·lula i, a més, permet estudiar el complement cromosòmic sencer. La freqüència d'aneuploïdia dels oòcits humans és força variable segons els autors. Bàsicament és degut al fet que s'analitzen amb diferents tècniques diferents tipus d'oòcits: els resultats amb CGH en oòcits (envellits o no) de dones incloses en cicles de FIV i en oòcits frescos de donants oscil·len entre el 22 % i el 65 %. Els mecanismes d'origen proposats són principalment alteracions produïdes a l'anafase i, com la no-disjunció d'homòlegs o la separació precoç de cromàtides germanes, encara que també s'han vist fallades en la segregació mitòtica d'oogònies en etapes inicials del desenvolupament embrionari. L'aplicació translacional dels estudis ha afavorit el desenvolupament del diagnòstic genètic preimplantacional, mitjançant FISH o CGH, per al diagnòstic d'aneuploïdies d'origen femení. Un dels reptes actuals és incrementar la taxa d'implantació dels embrions transferits.The availability of biologic material discarded from IVF cycles has been pretty valuable for the study of aneuploidies in the first stages of embryonic development. The cytogenetic study of human oocytes requires the analysis of the MII oocyte and the corresponding 1rstPB separately. Fluorescent in situ hybridization and its variants, such as SKY, PRINS or cenM-FISH, have been very useful, although these techniques require a previous cell fixation. As an alternative, CGH does not require cell fixation and furthermore, it allows for the study of the whole chromosomal complement. Aneuploidy rate from published CGH results show a great variability. It ranges from 22% to 65%. This variability is mainly due to the use of different material: oocytes from women undergoing IVF and fresh oocytes from donors The mechanisms proposed for aneuploidy production are mainly alterations produced in anaphase I, such as homologous non-disjunction and premature separation of sister chromatids. Mitotic segregation failure in the oogonies produced during the early stages of embryonic development has also been reported. The translational application of studies has favoured the development of PGD, by means of FISH or CGH, for the aneuploidy diagnostic of female origin. At this moment, one of the challenges is to increase the implantation rate of the transferred embryos

Expansive oral giant cell granuloma in a pediatric patient

Aim: This article describes a peripheral oral giant cell granuloma (POGCG) in a pediatric patient and its surgical management and histological characteristics. Background: Peripheral oral giant cell granuloma (POGCG) is a hyperplastic reactive lesion formed by a proliferation of mononuclear cells and osteoclast-type giant cells in vascular tissue, occasionally with bone formation. Generally found in women and adults, POGCG has rarely been described in children. Case description: An 8-year-old girl was consulted for an exophytic lesion in the anterior area of the upper jaw, which had increased in volume in the preceding weeks. An excisional biopsy of the tumor was performed with an electrosurgical pencil. The pathological diagnosis was POGCG. Conclusion: Excision followed by additional therapy, such as scaling and curettage, should be the first option in the treatment of POGCG. Clinical significance: Early detection of these lesions involving the periodontium is important in order to reduce bone loss and avoid pathological dental migration

Long-term Follow-up of Sexual Quality of Life after Laparoscopic Surgery in Patients with Deep Infiltrating Endometriosis

Study Objective: We performed a long-term follow-up to quantify the impairment of sexual quality of life (SQL) and health-related QL (HRQL) in sexually active women after laparoscopic excision of deep infiltrating endometriosis (DIE). Design: Prospective case-control study. Setting: Hospital Clinic of Barcelona. Patients: A total of 193 patients (after dropout and exclusions) were divided into 2 groups: one hundred twenty-nine premenopausal women with DIE (DIE group) and 64 healthy women who underwent tubal ligation (C group). Interventions: All patients underwent laparoscopic surgery: laparoscopic endometriosis surgery in the DIE group and laparoscopic tubal ligation in the C group. All women were followed for at least 36 months, and they completed the Medical Outcomes Study 36-item short form questionnaire to assess their HRQL and 3 self-administered questionnaires that evaluate different aspects of SQL: the generic Sexual Quality of Life−Female questionnaire, the Female Sexual Distress Scale to evaluate 'sexually related distress,' and the Brief Profile of Female Sexual Function to screen hypoactive sexual desire disorder. The patients with DIE as well as the controls completed the 4 questionnaires before surgery, and the patients with DIE also completed the questionnaires at 6 and 36 months after surgery. Measurements and Main Results: A comparison of the patients and controls before surgery showed a statistically significant impairment in SQL and HRQL among the patients with DIE. A statistically significant improvement in SQL and HRQL was observed in the DIE group 6 months after surgery, with scores being similar to those of the C group. An evaluation 36 months after surgery showed that SQL and HRQL were better than presurgical SQL and HRQL in the DIE group, with a slight reduction compared with the 6-month evaluation. Conclusion: SQL and HRQL improved in patients with DIE undergoing complete laparoscopic endometriosis resection and were comparable to those of healthy women at 6 months after surgery, showing a slight reduction at 36 months of follow-up

Assessing vaginal wall thickness by transvaginal ultrasound in breast cancer survivors: A pilot study

Aim: There is need for a straightforward objective measure to evaluate vaginal wall changes related to hypoestrogenism. The aim of this pilot study was to evaluate a transvaginal ultrasound procedure for the quantification of vaginal wall thickness in order to differentiate between healthy premenopausal women and postmenopausal women with genitourinary syndrome of menopause using ultra-low-level estrogen status as a model. Methods: We performed a prospective, two-arm, cross-sectional pilot study comparing vaginal wall thickness measured by transvaginal ultrasound in postmenopausal breast cancer survivors using aromatase inhibitors with genitourinary syndrome of menopause (GSM group) and healthy premenopausal women (control or C group) from October 2020 to March 2022. After intravaginal introduction of 20 cm3 of sonographic gel, vaginal wall thickness was measured by transvaginal ultrasound in the anterior, posterior, and right and left lateral walls (four quadrants). The study methods followed the STROBE checklist. Results: According to the results of a two-sided t-test, the mean vaginal wall thickness of the four quadrants in the GSM group was significantly less than that of the C group (2.25 mm vs 4.17 mm, respectively; p < 0.001). Likewise, the thickness of each of the vaginal walls (anterior, posterior, right and left lateral) statistically differed between the two groups (p < 0.001). Conclusion: Transvaginal ultrasound with intravaginal gel may be a feasible objective technique to assess genitourinary syndrome of menopause, showing clear differences in vaginal wall thickness between breast cancer survivors using aromatase inhibitors and premenopausal women. Possible correlations with symptoms or treatment response should be assessed in future studies

Characterization of the Use of Emergency Contraception from Sentinel Pharmacies in a Region of Southern Europe

Numerous studies have been published suggesting that emergency contraception (EC) is used repeatedly, but a lack of information regarding the profile of users makes it difficult to evaluate actual consumer habits. The aim of this study was to obtain information regarding the profile of users who obtain EC and other factors that might play a role, and to provide criteria to evaluate and improve the strategies of current contraceptive programs. This was an observational one-year study based on surveillance data on the provision of EC to women of reproductive age in 60 community pharmacies in Catalonia, Spain. In total, 941 notifications of dispensation of EC in Catalonia were received. A total of 44.2% of users said it was not the first time that they had taken the medication (repeat user). The percentage of users who used condoms was lower in repeat users compared to first-time users (56.7% vs. 64.4%, p < 0.05). A total of 25.7% of users stated that they did not use any barrier contraceptive method. The use of natural methods in repeat users was 53.8% in the subgroup who requested the medication after 48 h, significantly higher than in users who obtained the medication within the first 24 h (p < 0.05). A high percentage of repeat users with risky sexual behaviors were detected, suggesting that new measures must be implemented to provide information for this method, together with educational and preventive strategies

Sección abierta de homenaje a Laura Rubio

Secció oberta d'homenatge a Laura RubioOpen section tribute to Laura RubioSección abierta de homenaje a Laura Rubi

Sección abierta de homenaje a Laura Rubio

Sección abierta de homenaje a Laura Rubi

Hibridació Genòmica Comparada ràpida: aplicació al Diagnòstic Genètic Preimplantacional

El diagnòstic genètic preimplantaional (PGD) permet seleccionar, dins un programa de fecundació in vitro (FIV), embrions lliures d’alteracions cromosòmiques per a la transferència a l’úter matern. Actualment, la tècnica més freqüentment utilitzada per a aquesta finalitat és la hibridació in situ fluorescent (FISH), que tan sols permet analitzar de manera rutinària nou dels 24 tipus diferents de cromosomes existents. Una tècnica alternativa menys emprada és la hibridació genòmica comparada (CGH), que permet una anàlisi citogenètica completa de tot el cariotip. Aquesta metodologia, però, requereix un temps major que la duració del cicle de FIV per obtenir els resultats, de manera que els embrions analitzats s’han de criopreservar i transferir en un altre cicle addicional. L’objectiu d’aquest treball ha estat desenvolupar i aplicar una metodologia de CGH ràpida en què el temps d’hibridació s’ha reduït de 72 hores a 12 hores, de manera que no sigui necessària la criopreservació. Per a la seva posada a punt, s’han analitzat 32 fibroblasts aïllats de línies cel·lulars establertes (Coriel) amb alteracions cromosòmiques conegudes, el resultat de CGH ràpida dels quals ha confirmat en tots els casos la presència d’aquestes alteracions. Un cop desenvolupat el protocol de CGH ràpida, s’ha adaptat i validat per a l’anàlisi de blastòmers, emprant embrions descartats de casos de PGD mitjançant FISH amb nou sondes per als cromosomes 13, 15, 16, 17, 18, 21, 22, X i Y (FISH-9-cr). Aquesta anàlisi ha posat de manifest que les discordances entre els resultats de la CGH ràpida i els de la FISH-9-cr són degudes principalment a l’existència de mosaïcisme, però també a errors de la FISH. La CGH ràpida també s’ha utilitzat per fer l’anàlisi de 22 embrions de pacients amb edat materna avançada descartats del PGD amb FISH-9-cr. Aquest estudi ha revelat la presència d’aneuploïdies (el 38,5% de les quals no s’haurien detectat mitjançant la FISH) i d’alteracions estructurals (en el 31,8% dels embrions), així com de mosaïcisme (en el 77,3% dels embrions) en els diferents blastòmers analitzats. Un cop demostrada la seva fiabilitat, la tècnica s’ha aplicat clínicament per al cribatge d’aneuploïdies en dos casos d’edat materna avançada, dos casos d’avortaments de repetició i un cas de fallades repetides d’implantació, en els quals s’ha obtingut una taxa d’implantació dels embrions transferits del 60%. Prèvia comprovació que la CGH ràpida era capaç de detectar desequilibris parcials de cromosomes amb un límit de resolució de 10-20Mb, aquesta metodologia s’ha aplicat en el PGD de portadors de translocacions cromosòmiques Robertsonianes (tres casos, quatre cicles de FIV-PGD), recíproques (dos casos, tres cicles de FIV-PGD) i un cas d’una doble translocació (tres cicles de FIV-PGD), en els quals s’ha obtingut un elevat èxit de diagnòstic i dos embarassos. En aquests casos, la CGH ràpida permet estudiar la segregació dels cromosomes implicats en la reorganització, alhora que la resta de cromosomes de la cèl·lula. La variant de CGH desenvolupada, doncs, permet estudiar tots els cromosomes de la cèl·lula i detectar-hi tant alteracions numèriques com estructurals en un sol procediment que, degut a la reducció del temps d’hibridació, és compatible amb la transferència en fresc dels embrions seleccionats. Per tant, la seva implementació pot incrementar la taxa d’implantació dels embrions transferits després del PGD.Preimplantation genetic diagnosis (PGD) concurrent to in vitro fertilization (IVF) allows for the selection of embryos free of chromosomal abnormalities for transfer into the mother uterus. Nowadays, the technique most frequently used for this purpose is fluorescent in situ hybridization (FISH), which routinely allows for the study of only nine of the 24 existing chromosomes. Comparative genomic hybridization (CGH), although applied less frequently, is an alternative approach which permits a comprehensive cytogenetic study of the full karyotype. This method, nevertheless, requires a time greater than the length of the IVF cycle to get the results, so the embryos analyzed must be cryopreserved and transferred in a subsequent additional IVF cycle. The objective of this work was to develop and apply a short-CGH methodology in which the hybridization time is reduced from 72 hours to 12 hours, so that cryopreservation of biopsied embryos is no necessary. Thirty-two fibroblasts isolated from established cell lines (Coriel) with known aneuploidies have been used to develop the short-CGH protocol, obtaining results that confirmed the presence of these aneuploidies in all the studied cells. Subsequently, the method was adapted and validated for the analysis of blastomeres, using discarded embryos from PGD by FISH with nine probes for chromosomes 13, 15, 16, 17, 18, 21, 22, X and Y (FISH-9-cr). The short-CGH analysis revealed that the discordances between short-CGH results and FISH-9-cr results are mainly due to the existence of mosaicism, but also to FISH errors. The short-CGH approach has also been used for the analysis of 22 embryos from advanced maternal age patients, discarded by FISH-9-cr PGD. This study detected aneuploidies (38.5% of which could not have been detected by FISH), structural errors (in 31.8% of the embryos) and mosaicism (in 77.3% of the embryos) among the analysed blastomeres. Once its reliability was proven, this technique has been clinically applied for aneuploidy screening in two advanced maternal age cases, two recurrent miscarriage cases and a repeated implantation failure case, allowing a 60% implantation rate. After checking that short-CGH is capable of detecting partial chromosomal imbalances with a resolution limit of 10-20Mb, this approach has been applied in PGD for chromosomal Robertsonian translocation carriers (three cases, four IVF-PGD cycles), reciprocal translocation carriers (two cases, three IVF-PGD cycles) and a double translocation carrier (three IVF-PGD cycles), in which high diagnosis rate and two pregnancies have been achieved. In these cases, short-CGH allows for the study of the chromosomes involved in the reorganization simultaneously to the analysis of the remaining complement chromosomes. In conclusion, the developed CGH variant permits the study of the full karyotype, detecting both numerical and structural chromosomal abnormalities in a single process that, due to the reduction of the hybridization period, is compatible with fresh transfer of the selected embryos. Therefore, its implementation may improve the implantation rate of the transferred embryos after PGD