The Protein Matrix of Plastocyanin Supports Long-Distance Charge Transport with Photosystem I and the Copper Ion Regulates Its Spatial Span and Conductance.

Charge exchange is the fundamental process that sustains cellular respiration and photosynthesis by shuttling electrons in a cascade of electron transfer (ET) steps between redox cofactors. While intraprotein charge exchange is well characterized in protein complexes bearing multiple redox sites, interprotein processes are less understood due to the lack of suitable experimental approaches and the dynamic nature of the interactions. Proteins constrained between electrodes are known to support electron transport (ETp) through the protein matrix even without redox cofactors, as the charges housed by the redox sites in ET are furnished by the electrodes. However, it is unknown whether protein ETp mechanisms apply to the interprotein medium present under physiological conditions. We study interprotein charge exchange between plant photosystem I (PSI) and its soluble redox partner plastocyanin (Pc) and address the role of the Pc copper center. Using electrochemical scanning tunneling spectroscopy (ECSTS) current-distance and blinking measurements, we quantify the spatial span of charge exchange between individual Pc/PSI pairs and ETp through transient Pc/PSI complexes. Pc devoid of the redox center (Pcapo) can exchange charge with PSI at longer distances than with the copper ion (Pcholo). Conductance bursts associated with Pcapo/PSI complex formation are higher than in Pcholo/PSI. Thus, copper ions are not required for long-distance Pc/PSI ETp but regulate its spatial span and conductance. Our results suggest that the redox center that carries the charge in Pc is not necessary to exchange it in interprotein ET through the aqueous solution and question the canonical view of tight complex binding between redox protein partners.

Kinetic characterization and phylogenetic analysis of human ADP-dependent glucokinase reveal new insights into its regulatory properties.

Although ADP-dependent sugar kinases were first described in archaea, at present, the presence of an ADP-dependent glucokinase (ADP-GK) in mammals is well documented. This enzyme is mainly expressed in hematopoietic lineages and tumor tissues, although its role has remained elusive. Here, we report a detailed kinetic characterization of the human ADP-dependent glucokinase (hADP-GK), addressing the influence of a putative signal peptide for endoplasmic reticulum (ER) destination by characterizing a truncated form. The truncated form revealed no significant impact on the kinetic parameters, showing only a slight increase in the Vmax value, higher metal promiscuity, and the same nucleotide specificity as the full-length enzyme. hADP-GK presents an ordered sequential kinetic mechanism in which MgADP is the first substrate to bind and AMP is the last product released, being the same mechanism described for archaeal ADP-dependent sugar kinases, in agreement with the protein topology. Substrate inhibition by glucose was observed due to sugar binding to nonproductive species. Although Mg2+ is an essential component for kinase activity, it also behaves as a partial mixed-type inhibitor for hADP-GK, mainly by decreasing the MgADP affinity. Regarding its distribution, phylogenetic analysis shows that ADP-GK's are present in a wide diversity of eukaryotic organisms although it is not ubiquitous. Eukaryotic ADP-GKs sequences cluster into two main groups, showing differences in the highly conserved sugar-binding motif reported for archaeal enzymes [NX(N)XD] where a cysteine residue is found instead of asparagine in a significant number of enzymes. Site directed mutagenesis of the cysteine residue by asparagine produces a 6-fold decrease in Vmax, suggesting a role for this residue in the catalytic process, probably by facilitating the proper orientation of the substrate to be phosphorylated.

Blocking bacterial appendage attachment to wastewater treatment membranes using anti-adhesins.

Membrane bioreactors (MBRs) suffer from high operational and cleaning costs due to biofouling. The biofouling begins when the adhesins (an anchor-type epitope made up of polar and charged amino acids) on microbial appendages bind to the surface. Two different compounds-dodecyl-ß-D-maltoside (DDM) and methyl α-d-mannopyranoside (MeαMan)-were investigated as possible biofilm mitigation tools due to their documented anti-adhesin properties in the biomedical field. DDM prevented up to 56.3, 87.0, and 67.6% of the formation of Pseudomonas putida, Escherichia coli and wastewater culture biofilms, respectively, in microplate experiments. MeαMan increased biofilm in the microplates. In a biofilm reactor setting, DDM was then applied on typical membrane materials, polyvinylidene fluoride, polyamide, polyether-sulfone, and polyacrylonitrile and prevented 79.4, 62.5, 81.3, and 68.2% of the detectable wastewater culture biofilm formation, respectively. The mechanism of anti-adhesion was the binding of the polar head of the DDM to the polar amino acids of the microbial appendages in conjunction with the orientation of the DDM as it binds different membrane materials. If the anti-adhesins are effective at increasing the distance of the bacteria from the membrane materials, they will serve as a new method for delaying biofouling.

Light- and Redox-Dependent Force Spectroscopy Reveals that the Interaction between Plastocyanin and Plant Photosystem I Is Favored when One Partner Is Ready for Electron Transfer.

Photosynthesis is a fundamental process that converts photons into chemical energy, driven by large protein complexes at the thylakoid membranes of plants, cyanobacteria, and algae. In plants, water-soluble plastocyanin (Pc) is responsible for shuttling electrons between cytochrome b6f complex and the photosystem I (PSI) complex in the photosynthetic electron transport chain (PETC). For an efficient turnover, a transient complex must form between PSI and Pc in the PETC, which implies a balance between specificity and binding strength. Here, we studied the binding frequency and the unbinding force between suitably oriented plant PSI and Pc under redox control using single molecule force spectroscopy (SMFS). The binding frequency (observation of binding-unbinding events) between PSI and Pc depends on their respective redox states. The interaction between PSI and Pc is independent of the redox state of PSI when Pc is reduced, and it is disfavored in the dark (reduced P700) when Pc is oxidized. The frequency of interaction between PSI and Pc is higher when at least one of the partners is in a redox state ready for electron transfer (ET), and the post-ET situation (PSIRed-PcOx) leads to lower binding. In addition, we show that the binding of ET-ready PcRed to PSI can be regulated externally by Mg2+ ions in solution.

Self-Organization Dynamics of Collagen-like Peptides Crosslinking Is Driven by Rose-Bengal-Mediated Electrostatic Bridges.

The present work focuses on the computational study of the structural micro-organization of hydrogels based on collagen-like peptides (CLPs) in complex with Rose Bengal (RB). In previous studies, these hydrogels computationally and experimentally demonstrated that when RB was activated by green light, it could generate forms of stable crosslinked structures capable of regenerating biological tissues such as the skin and cornea. Here, we focus on the structural and atomic interactions of two collagen-like peptides (collagen-like peptide I (CLPI), and collagen-like peptide II, (CLPII)) in the presence and absence of RB, highlighting the acquired three-dimensional organization and going deep into the stabilization effect caused by the dye. Our results suggest that the dye could generate a ternary ground-state complex between collagen-like peptide fibers, specifically with positively charged amino acids (Lys in CLPI and Arg in CLPII), thus stabilizing ordered three-dimensional structures. The discoveries generated in this study provide the structural and atomic bases for the subsequent rational development of new synthetic peptides with improved characteristics for applications in the regeneration of biological tissues during photochemical tissue bonding therapies.

Dendrimersome Synthetic Cells Harbor Cell Division Machinery of Bacteria.

The integration of active cell machinery with synthetic building blocks is the bridge toward developing synthetic cells with biological functions and beyond. Self-replication is one of the most important tasks of living systems, and various complex machineries exist to execute it. In Escherichia coli, a contractile division ring is positioned to mid-cell by concentration oscillations of self-organizing proteins (MinCDE), where it severs membrane and cell wall. So far, the reconstitution of any cell division machinery has exclusively been tied to liposomes. Here, the reconstitution of a rudimentary bacterial divisome in fully synthetic bicomponent dendrimersomes is shown. By tuning the membrane composition, the interaction of biological machinery with synthetic membranes can be tailored to reproduce its dynamic behavior. This constitutes an important breakthrough in the assembly of synthetic cells with biological elements, as tuning of membrane-divisome interactions is the key to engineering emergent biological behavior from the bottom-up.

Distance and Potential Dependence of Charge Transport Through the Reaction Center of Individual Photosynthetic Complexes.

Charge separation and transport through the reaction center of photosystem I (PSI) is an essential part of the photosynthetic electron transport chain. A strategy is developed to immobilize and orient PSI complexes on gold electrodes allowing to probe the complex's electron acceptor side, the chlorophyll special pair P700. Electrochemical scanning tunneling microscopy (ECSTM) imaging and current-distance spectroscopy of single protein complex shows lateral size in agreement with its known dimensions, and a PSI apparent height that depends on the probe potential revealing a gating effect in protein conductance. In current-distance spectroscopy, it is observed that the distance-decay constant of the current between PSI and the ECSTM probe depends on the sample and probe electrode potentials. The longest charge exchange distance (lowest distance-decay constant ß) is observed at sample potential 0 mV/SSC (SSC: reference electrode silver/silver chloride) and probe potential 400 mV/SSC. These potentials correspond to hole injection into an electronic state that is available in the absence of illumination. It is proposed that a pair of tryptophan residues located at the interface between P700 and the solution and known to support the hydrophobic recognition of the PSI redox partner plastocyanin, may have an additional role as hole exchange mediator in charge transport through PSI.

Fast Photo-Chrono-Amperometry of Photosynthetic Complexes for Biosensors and Electron Transport Studies.

Photosynthetic reactions in plants, algae, and cyanobacteria are driven by photosystem I and photosystem II complexes, which specifically reduce or oxidize partner redox biomolecules. Photosynthetic complexes can also bind synthetic organic molecules, which inhibit their photoactivity and can be used both to study the electron transport chain and as herbicides and algicides. Thus, their development, characterization, and sensing bears fundamental and applied interest. Substantial efforts have been devoted to developing photosensors based on photosystem II to detect compounds that bind to the plastoquinone sites of this complex. In comparison, photosystem I based sensors have received less attention and could be used to identify novel substances displaying phytotoxic effects, including those obtained from natural product extracts. We have developed a robust procedure to functionalize gold electrodes with photo- and redox-active photosystem I complexes based on transparent gold and a thiolate self-assembled monolayer, and we have obtained reproducible electrochemical photoresponses. Chronoamperometric recordings have allowed us to measure photocurrents in the presence of the viologen derivative paraquat at concentrations below 100 nM under lock-in operation and a sensor dynamic range spanning six orders of magnitude up to 100 mM. We have modeled their time course to identify the main electrochemical processes and limiting steps in the electron transport chain. Our results allow us to isolate the contributions from photosystem I and the redox mediator, and evaluate photocurrent features (spectral and power dependence, fast transient kinetics) that could be used as a sensing signal to detect other inhibitors and modulators of photosystem I activity.

Free radicals derived from γ-radiolysis of water and AAPH thermolysis mediate oxidative crosslinking of eGFP involving Tyr-Tyr and Tyr-Cys bonds: the fluorescence of the protein is conserved only towards peroxyl radicals.

The enhanced green fluorescent protein (eGFP) is one of the most employed variants of fluorescent proteins. Nonetheless little is known about the oxidative modifications that this protein can undergo in the cellular milieu. The present work explored the consequences of the exposure of eGFP to free radicals derived from γ-radiolysis of water, and AAPH thermolysis. Results demonstrated that protein crosslinking was the major pathway of modification of eGFP towards these oxidants. As evidenced by HPLC-FLD and UPLC-MS, eGFP crosslinking would occur as consequence of a mixture of pathways including the recombination of two protein radicals, as well as secondary reactions between nucleophilic residues (e.g. lysine, Lys) with protein carbonyls. The first mechanism was supported by detection of dityrosine and cysteine-tyrosine bonds, whilst evidence of formation of protein carbonyls, along with Lys consumption, would suggest the formation and participation of Schiff bases in the crosslinking process. Despite of the degree of oxidative modifications elicited by peroxyl radicals (ROO•) generated from the thermolysis of AAPH, and free radicals generated from γ-radiolysis of water, that were evidenced at amino acidic level, only the highest dose of γ-irradiation (10 kGy) triggered significant changes in the secondary structure of eGFP. These results were accompanied by the complete loss of fluorescence arising from the chromophore unit of eGFP in γ-irradiation-treated samples, whereas it was conserved in ROO•-treated samples. These data have potential biological significance, as this fluorescent protein is widely employed to study interactions between cytosolic proteins; consequently, the formation of fluorescent eGFP dimers could act as artifacts in such experiments.

Coriocarcinoma no gestacional: reporte de un caso / No gestational choriocarcinoma: case report

Resumen ANTECEDENTES: El coriocarcinoma es una neoplasia maligna del epitelio trofoblástico, agresiva pero susceptible de curación, incluso cuando hay metástasis. Puede ser de origen gestacional o no, el primero aparece después de un embarazo molar o aborto. CASO CLÍNICO: Paciente de 14 años, acudió a Urgencias debido a un cuadro de abdomen agudo, con prueba en orina positiva de embarazo; además, una tumoración en la región anexial derecha. En la laparotomía se encontró una tumoración dependiente del anexo derecho, con la cápsula rota, adherida al colon. Un día después de la intervención quirúrgica (por no contar con recursos en la unidad) se tomó la fracción beta de gonadotropina coriónica. El diagnóstico definitivo se estableció con base en el reporte del estudio histopatológico de la pieza quirúrgica. CONCLUSIÓN: El coriocarcinoma es una neoplasia maligna del epitelio trofoblástico, muy agresiva pero susceptible de curación, incluso cuando se detectan metástasis. La incidencia en México de coriocarcinoma gestacional es de 0.133 por cada 100,000 mujeres, mientras que la incidencia del cariocarcinoma no gestacional se desconoce. Se reporta como un tumor muy raro; por ello el diagnóstico preciso y oportuno es difícil en este tipo de tumores; la presentación más habitual es el abdomen agudo.

Abstract BACKGROUND: Choriocarcinoma is a malignant neoplasm of the trophoblastic epithelium, very aggressive but highly curable, even when there is metastasis. It can be of gestational and non-gestational origin, the first one can develop after a pregnancy, abortion or molar pregnancy; in Mexico it is calculated with an incidence of 0.133 per 100,000 women. While the incidence of non-gestational choriocarcinoma is unknown as it is reported as a very rare tumor. The objective is present the first case reported in our hospital, there are few cases reported in Mexico, it is important to know them in order to identify, diagnose and refer them on time. CLINICAL CASE: A 14-year-old patient who presented to the emergency department with a picture of acute abdomen with pregnancy test in positive urine and tumor in the right adnexal region, laparotomy was performed, finding a tumor dependent on the right annex with a broken capsule attached to the colon, one day after the surgical event (due to lack of resources in the unit) beta fraction of chorionic gonadotropin, the definitive diagnosis was made by the histopathological study of the surgical piece. CONCLUSION: Choriocarcinoma is a malignant neoplasm of the trophoblastic epithelium, very aggressive but highly curable, even when metastases are detected. In Mexico, the incidence of gestational choriocarcinoma is 0.133 per 100,000 women, while the incidence of non-gestational cariocarcinoma is unknown, it is reported as a very rare tumor, which is why accurate and early diagnosis is difficult in this type of tumors. , since the most common presentation is an acute abdomen.

Theoretical rationalisation of the photophysics of a TICT excited state of cinnamoyl-coumarin derivatives in homogeneous and biological membrane models.

A new hybrid cinnamoyl-coumarin probe was synthesised to study the formation and dynamics of a twisted internal charge transfer (TICT) excited state in homogeneous and biological membrane models. This probe showed a large bathochromic shift of the fluorescence band with the solvent polarity, which is associated with the decrease in the fluorescence intensity due to fast non-radiative deactivation pathways, ascribed to TICT excited state formation in polar solvents. The calculated potential energy surfaces using density functional theory (DFT) and time dependent-DFT (TD-DFT) along with the energetic barriers calculated using the ABF methodology established the energy requirements for a rotational twisting of the cinnamoyl-coumarin bond for TICT excited state formation. This strategy has allowed estimating the role of the ground state conformation and excited state distribution that, concomitant with fluorescence lifetime measurements, describes in detail dual fluorescence emission from TICT and ICT excited states. Moreover, the high sensitivity of fluorescence lifetimes of the TICT excited state in liposomes allows us to propose the use of this type of probes as a powerful tool for the study of gel and crystalline liquid phases in lipid membrane models. The development of this new approach will allow rationalizing and understanding the photochemical behavior of fluorescent TICT-based probes in constrained biological environments.

ADP-Dependent Kinases From the Archaeal Order Methanosarcinales Adapt to Salt by a Non-canonical Evolutionarily Conserved Strategy.

Halophilic organisms inhabit hypersaline environments where the extreme ionic conditions and osmotic pressure have driven the evolution of molecular adaptation mechanisms. Understanding such mechanisms is limited by the common difficulties encountered in cultivating such organisms. Within the Euryarchaeota, for example, only the Halobacteria and the order Methanosarcinales include readily cultivable halophilic species. Furthermore, only the former have been extensively studied in terms of their component proteins. Here, in order to redress this imbalance, we investigate the halophilic adaptation of glycolytic enzymes from the ADP-dependent phosphofructokinase/glucokinase family (ADP-PFK/GK) derived from organisms of the order Methanosarcinales. Structural analysis of proteins from non-halophilic and halophilic Methanosarcinales shows an almost identical composition and distribution of amino acids on both the surface and within the core. However, these differ from those observed in Halobacteria or Eukarya. Proteins from Methanosarcinales display a remarkable increase in surface lysine content and have no reduction to the hydrophobic core, contrary to the features ubiquitously observed in Halobacteria and which are thought to be the main features responsible for their halophilic properties. Biochemical characterization of recombinant ADP-PFK/GK from M. evestigatum (halophilic) and M. mazei (non-halophilic) shows the activity of both these extant enzymes to be only moderately inhibited by salt. Nonetheless, its activity over time is notoriously stabilized by salt. Furthermore, glycine betaine has a protective effect against KCl inhibition and enhances the thermal stability of both enzymes. The resurrection of the last common ancestor of ADP-PFK/GK from Methanosarcinales shows that the ancestral enzyme displays an extremely high salt tolerance and thermal stability. Structure determination of the ancestral protein reveals unique traits such as an increase in the Lys and Glu content at the protein surface and yet no reduction to the volume of the hydrophobic core. Our results suggest that the halophilic character is an ancient trait in the evolution of this protein family and that proteins from Methanosarcinales have adapted to highly saline environments by a non-canonical strategy, different from that currently proposed for Halobacteria. These results open up new avenues for the search and development of novel salt tolerant biocatalysts.

ADP-dependent phosphofructokinases from the archaeal order Methanosarcinales display redundant glucokinase activity.

The genome of Methanosarcinales organisms presents both ADP-dependent glucokinase and phosphofructokinase genes. However, Methanococcoides burtonii has a truncate glucokinase gene with a large deletion at the C-terminal, where the catalytic GXGD motif is located. Characterization of its phosphofructokinase annotated protein shows that is a bifunctional enzyme able to supply the absence of the glucokinase activity. Moreover, kinetic analyses of the phosphofructokinase annotated enzyme from, Methanohalobium evestigatum demonstrated that this enzyme is also bifunctional. The high conservation of the active site residues of all the enzymes from the order Methanosarcinales suggest that they should be bifunctional, as was previously reported for the ADP-dependent kinases from Methanococcales, highlighting the redundancy of the glucokinase activity in this archaeal group. The presence of active glycolytic enzymes would be important when glycogen storage of these organisms needs to be degraded to be used as energy source. Kinetic and structural information allows us to establish a substrate specificity signature that identifies specific GK or PFK, and bifunctional enzymes in this family.

Reconstructed ancestral enzymes reveal that negative selection drove the evolution of substrate specificity in ADP-dependent kinases.

One central goal in molecular evolution is to pinpoint the mechanisms and evolutionary forces that cause an enzyme to change its substrate specificity; however, these processes remain largely unexplored. Using the glycolytic ADP-dependent kinases of archaea, including the orders Thermococcales, Methanosarcinales, and Methanococcales, as a model and employing an approach involving paleoenzymology, evolutionary statistics, and protein structural analysis, we could track changes in substrate specificity during ADP-dependent kinase evolution along with the structural determinants of these changes. To do so, we studied five key resurrected ancestral enzymes as well as their extant counterparts. We found that a major shift in function from a bifunctional ancestor that could phosphorylate either glucose or fructose 6-phosphate (fructose-6-P) as a substrate to a fructose 6-P-specific enzyme was started by a single amino acid substitution resulting in negative selection with a ground-state mode against glucose and a subsequent 1,600-fold change in specificity of the ancestral protein. This change rendered the residual phosphorylation of glucose a promiscuous and physiologically irrelevant activity, highlighting how promiscuity may be an evolutionary vestige of ancestral enzyme activities, which have been eliminated over time. We also could reconstruct the evolutionary history of substrate utilization by using an evolutionary model of discrete binary characters, indicating that substrate uses can be discretely lost or acquired during enzyme evolution. These findings exemplify how negative selection and subtle enzyme changes can lead to major evolutionary shifts in function, which can subsequently generate important adaptive advantages, for example, in improving glycolytic efficiency in Thermococcales.

Identification of brain areas sensitive to the toxic effects of sparteine.

Sparteine is one of the most toxic quinolizidine alkaloids found in leguminous plants. Several studies have demonstrated that sparteine affects the nervous system, blocking the nervous ganglion, producing antimuscarinic effects, depressing the central nervous system and causing neuronal necrosis. However, there are no reports identifying the areas of the brain that are sensitive to the toxic effects of this alkaloid. 32 adult Wistar rats were on study, sixteen were implanted with an intracerebral stainless steel cannula and randomly assigned to a control or experimental group (n=8). Animals, control and experimental, received daily intraventricular (ICV) injections of a sparteine or a sterile water solution for five consecutive days. Additionally, two groups of animals (8 rats each) received daily intraperotineal injections (IP) of a sparteine or sterile water solution for five consecutive days. 72h after the last dose, the animals were sacrificed, their brains removed, fixed and embedded in paraffin to obtain 10µm tissue slices. Brain slices were stained with H&E and evaluated under a light microscope. The main brain structures sensitive to sparteine were the cerebral cortex (frontal, fronto-parietal and striate) olfactory and amygdaloid areas, the ventromedial hypothalamic nucleus, the Purkinje cells in the cerebellum, and the CA1, CA3 and dentate gyrus regions of the hippocampus. Administration of sparteine, via ICV or IP, caused neuronal necrosis in brain structures, mainly related with cholinergic pathways.

Discovery, Molecular Mechanisms, and Industrial Applications of Cold-Active Enzymes.

Cold-active enzymes constitute an attractive resource for biotechnological applications. Their high catalytic activity at temperatures below 25°C makes them excellent biocatalysts that eliminate the need of heating processes hampering the quality, sustainability, and cost-effectiveness of industrial production. Here we provide a review of the isolation and characterization of novel cold-active enzymes from microorganisms inhabiting different environments, including a revision of the latest techniques that have been used for accomplishing these paramount tasks. We address the progress made in the overexpression and purification of cold-adapted enzymes, the evolutionary and molecular basis of their high activity at low temperatures and the experimental and computational techniques used for their identification, along with protein engineering endeavors based on these observations to improve some of the properties of cold-adapted enzymes to better suit specific applications. We finally focus on examples of the evaluation of their potential use as biocatalysts under conditions that reproduce the challenges imposed by the use of solvents and additives in industrial processes and of the successful use of cold-adapted enzymes in biotechnological and industrial applications.

[Atipical uremic hemolityc syndrome in pregnancy]. / Síndrome urémico hemolítico atípico en el embarazo.

Atypical haemolytic uraemic syndrome is one of the main variants of thrombotic microangiopathy, and is characterized by excessive complement activation in the microvasculature. It is also characterised by the clinical triad; non-immune haemolytic anaemia, thrombocytopenia, and acute renal failure. In addition, 60% of patients have mutations in the genes encoding complement regulators (factor H, factor I, membrane cofactor proteins, and thrombomodulin), activators (factor B and C3), as well as autoantibodies against factor H. Multiple factors are required for the disease to manifest itself, including a trigger and gene mutations with adequate penetration. Being one of the differential diagnoses of preeclampsia- eclampsia and HELLP syndrome means that the clinician must be familiar with the disease due to its high mortality, which can be modified with early diagnosis and comprehensive treatment.

[Ovarian ectopic pregnancy with little common clinical presentation. A case report and bibliographical review]. / Embarazo ectópico ovárico con presentación clínica poco común. Reporte de caso y revisión de la bibliografía.

UNLABELLED: Ovarian ectopic pregnancy is only 3% of all ectopic, with an incidence of 1:7,000-40,000. In the last 10 years, it has been a rise in incidence. Most patients have vaginal bleeding, abdominal pain and shock data. Less than 300-400 cases are reported in the literature. CASE: We present the case of a woman with ovarian ectopic pregnancy of 12 weeks of gestation, who have not suggestive clinical signs and whose diagnosis was incidental despite having a regular prenatal ultrasound. CONCLUSION: Ovarian pregnancy is a rare presentation; diagnosis is difficult and often suggested by clinical data, when clinical data fail, more studies are needed to integrate the diagnosis.