Misspellings or "miscellings"-Non-verifiable and unknown cell lines in cancer research publications.

Reproducible laboratory research relies on correctly identified reagents. We have previously described gene research papers with wrongly identified nucleotide sequence(s), including papers studying miR-145. Manually verifying reagent identities in 36 recent miR-145 papers found that 56% and 17% of papers described misidentified nucleotide sequences and cell lines, respectively. We also found 5 cell line identifiers in miR-145 papers with misidentified nucleotide sequences and cell lines, and 18 cell line identifiers published elsewhere, that did not represent indexed human cell lines. These 23 identifiers were described as non-verifiable (NV), as their identities were unclear. Studying 420 papers that mentioned 8 NV identifier(s) found 235 papers (56%) that referred to 7 identifiers (BGC-803, BSG-803, BSG-823, GSE-1, HGC-7901, HGC-803, and MGC-823) as independent cell lines. We could not find any publications describing how these cell lines were established. Six cell lines were sourced from cell line repositories with externally accessible online catalogs, but these cell lines were not indexed as claimed. Some papers also stated that short tandem repeat (STR) profiles had been generated for three cell lines, yet no STR profiles could be identified. In summary, as NV cell lines represent new challenges to research integrity and reproducibility, further investigations are required to clarify their status and identities.

Soluble immune checkpoints as correlates for HIV persistence and T cell function in people with HIV on antiretroviral therapy.

Introduction: In people with HIV (PWH) both off and on antiretroviral therapy (ART), the expression of immune checkpoint (IC) proteins is elevated on the surface of total and HIV-specific T-cells, indicating T-cell exhaustion. Soluble IC proteins and their ligands can also be detected in plasma, but have not been systematically examined in PWH. Since T-cell exhaustion is associated with HIV persistence on ART, we aimed to determine if soluble IC proteins and their ligands also correlated with the size of the HIV reservoir and HIV-specific T-cell function. Methods: We used multiplex bead-based immunoassay to quantify soluble programmed cell death protein 1 (PD-1), cytotoxic T-lymphocyte-associated protein 4 (CTLA-4), lymphocyte activation gene-3 (LAG-3), T cell immunoglobulin domain and mucin domain 3 (TIM-3), PD-1 Ligand 1 (PD-L1) and PD-1 Ligand 2 (PD-L2) in plasma from PWH off ART (n=20), on suppressive ART (n=75) and uninfected controls (n=20). We also quantified expression of membrane-bound IC and frequencies of functional T-cells to Gag and Nef peptide stimulation on CD4+ and CD8+ T-cells using flow cytometry. The HIV reservoir was quantified in circulating CD4+ T-cells using qPCR for total and integrated HIV DNA, cell-associated unspliced HIV RNA and 2LTR circles. Results: Soluble (s) PD-L2 level was higher in PWH off and on ART compared to uninfected controls. Higher levels of sPD-L2 correlated with lower levels of HIV total DNA and higher frequencies of gag-specific CD8+ T-cells expressing CD107a, IFNγ or TNFα. In contrast, the concentration of sLAG-3 was similar in uninfected individuals and PWH on ART, but was significantly elevated in PWH off ART. Higher levels of sLAG-3 correlated with higher levels of HIV total and integrated DNA, and lower frequency of gag-specific CD4+ T cells expressing CD107a. Similar to sLAG-3, levels of sPD-1 were elevated in PWH off ART and normalized in PWH on ART. sPD-1 was positively correlated with the frequency of gag-specific CD4+ T cells expressing TNF-a and the expression of membrane-bound PD-1 on total CD8+ T-cells in PWH on ART. Discussion: Plasma soluble IC proteins and their ligands correlate with markers of the HIV reservoir and HIV-specific T-cell function and should be investigated further in in large population-based studies of the HIV reservoir or cure interventions in PWH on ART.

Fluorescence quenching in thylakoid membranes induced by single-walled carbon nanotubes.

The distinct photochemical and electrochemical properties of single-walled carbon nanotubes (SWCNTs) boosted the research interest in nanomaterial utilization in different in vivo and in vitro photosynthetic biohybrid setups. Aiming to unravel the yet not fully understood energetic interactions between the nanotubes and photosynthetic pigment-protein assemblies in an aqueous milieu, we studied SWCNT effects on the photochemical reactions of isolated thylakoid membranes (TMs), Photosystem II (PSII)-enriched membrane fragments and light-harvesting complexes (LHCII). The SWCNTs induced quenching of the steady-state chlorophyll fluorescence in the TM-biohybrid systems with a corresponding shortening of the average fluorescence lifetimes. The effect was not related to changes in the integrity and macroorganization of the photosynthetic membranes. Moreover, we found no evidence for direct excitation energy exchange between the SWCNTs and pigment-protein complexes, since neither the steady-state nor time-resolved fluorescence of LHCII-biohybrid systems differed from the corresponding controls. The attenuation of the fluorescence signal in the TM-biohybrid systems indicates possible leakage of photosynthetic electrons toward the nanotubes that most probably occurs at the level of the PSII acceptor site. Although it is too early to speculate on the nature of the involved electron donors and intermediate states, the observed energetic interaction could be exploited to increase the photoelectron capture efficiency of natural biohybrid systems for solar energy conversion.

Nanodiamond Particles Reduce Oxidative Stress Induced by Methyl Viologen and High Light in the Green Alga Chlamydomonas reinhardtii.

Widely used in biomedical and bioanalytical applications, the detonation nanodiamonds (NDs) are generally considered to be biocompatible and non-toxic to a wide range of eukaryotic cells. Due to their high susceptibility to chemical modifications, surface functionalisation is often used to tune the biocompatibility and antioxidant activity of the NDs. The response of photosynthetic microorganisms to redox-active NDs is still poorly understood and is the focus of the present study. The green microalga Chlamydomonas reinhardtii was used to assess the potential phytotoxicity and antioxidant activity of NDs hosting hydroxyl functional groups at concentrations of 5-80 µg NDs/mL. The photosynthetic capacity of microalgae was assessed by measuring the maximum quantum yield of PSII photochemistry and the light-saturated oxygen evolution rate, while oxidative stress was assessed by lipid peroxidation and ferric-reducing antioxidant capacity. We demonstrated that hydroxylated NDs might reduce cellular levels of oxidative stress, protect PSII photochemistry and facilitate the PSII repair under methyl viologen and high light associated stress conditions. Factors involved in this protection may include the low phytotoxicity of hydroxylated NDs in microalgae and their ability to accumulate in cells and scavenge reactive oxygen species. Our findings could pave the way for using hydroxylated NDs as antioxidants to improve cellular stability in algae-based biotechnological applications or semi-artificial photosynthetic systems.

Survey of Invasive Mosquito Surveillance and Control Capacity in Southeastern USA Reveals Training and Resource Needs.

Several invasive mosquito species that are nuisances or of medical and veterinary importance have been introduced into the Southeastern region of the USA, posing a threat to other species and the local ecosystems and/or increasing the risk of pathogen transmission to people, livestock, and domestic pets. Prompt and effective monitoring and control of invasive species is essential to prevent them from spreading and causing harmful effects. However, the capacity for invasive mosquito species surveillance is highly variable among mosquito control programs in the Southeast, depending on a combination of factors such as regional geography and climate, access to resources, and the ability to interact with other programs. To facilitate the development of invasive mosquito surveillance in the region, we, the Mosquito BEACONS (Biodiversity Enhancement and Control of Non-native Species) working group, conducted a survey on the capacities of various public health agencies and pest control agencies engaged in mosquito surveillance and control in seven Southeastern states (Alabama, Florida, Georgia, Louisiana, Mississippi, North Carolina, and South Carolina). Ninety control programs completed the survey, representing an overall response rate of 25.8%. We report key findings from our survey, emphasizing the training and resource needs, and discuss their implications for future invasive mosquito surveillance and control capacity building. By increasing communication and collaboration opportunities (e.g., real-time sharing of collection records, coordinated multistate programs), the establishment of Mosquito BEACONS and the implementation of this survey can accelerate knowledge transfer and improve decision support capacity in response to or in preparation for invasive mosquito surveillance and can establish infrastructure that can be used to inform programs around the world.

High-Yield Production of Chimeric Hepatitis E Virus-Like Particles Bearing the M2e Influenza Epitope and Receptor Binding Domain of SARS-CoV-2 in Plants Using Viral Vectors.

Capsid protein of Hepatitis E virus (HEV) is capable of self-assembly into virus-like particles (VLPs) when expressed in Nicotiana benthamiana plants. Such VLPs could be used as carriers of antigens for vaccine development. In this study, we obtained VLPs based on truncated coat protein of HEV bearing the M2e peptide of Influenza A virus or receptor-binding domain of SARS-CoV-2 spike glycoprotein (RBD). We optimized the immunogenic epitopes' presentation by inserting them into the protruding domain of HEV ORF2 at position Tyr485. The fusion proteins were expressed in Nicotiana benthamiana plants using self-replicating potato virus X (PVX)-based vector. The fusion protein HEV/M2, targeted to the cytosol, was expressed at the level of about 300-400 µg per gram of fresh leaf tissue and appeared to be soluble. The fusion protein was purified using metal affinity chromatography under native conditions with the final yield about 200 µg per gram of fresh leaf tissue. The fusion protein HEV/RBD, targeted to the endoplasmic reticulum, was expressed at about 80-100 µg per gram of fresh leaf tissue; the yield after purification was up to 20 µg per gram of fresh leaf tissue. The recombinant proteins HEV/M2 and HEV/RBD formed nanosized virus-like particles that could be recognized by antibodies against inserted epitopes. The ELISA assay showed that antibodies of COVID-19 patients can bind plant-produced HEV/RBD virus-like particles. This study shows that HEV capsid protein is a promising carrier for presentation of foreign antigen.

Task-selective place cells show behaviorally driven dynamics during learning and stability during memory recall.

Decades of work propose that hippocampal activity supports internal representation of learned experiences and contexts, allowing individuals to form long-term memories and quickly adapt behavior to changing environments. However, recent studies insinuate hippocampal representations can drift over time, raising the question: how could the hippocampus hold stable memories when activity of its neuronal maps fluctuates? We hypothesized that task-dependent hippocampal maps set by learning rules and structured attention stabilize as a function of behavioral performance. To test this, we imaged hippocampal CA1 pyramidal neurons during learning and memory recall phases of a new task where mice use odor cues to navigate between two reward zones. Across learning, both orthogonal and overlapping task-dependent place maps form rapidly, discriminating trial context with strong correlation to behavioral performance. Once formed, task-selective place maps show increased long-term stability during memory recall phases. We conclude that memory demand and attention stabilize hippocampal activity to maintain contextually rich spatial representations.

Single-walled carbon nanotubes protect photosynthetic reactions in Chlamydomonas reinhardtii against photoinhibition.

Single-walled carbon nanotubes (SWCNTs) are among the most exploited carbon allotropes in nanosensing, bioengineering, and photobiological applications, however, the interactions of nanotubes with the photosynthetic process and structures are still poorly understood. We found that SWCNTs are not toxic to the photosynthetic apparatus of the model unicellular alga Chlamydomonas reinhardtii and demonstrate that this carbon nanomaterial can protect algal photosynthesis against photoinhibition. The results show that the inherent phytotoxicity of the nanotubes may be overcome by an intentional selection of nanomaterial characteristics. A low concentration (2 µg mL-1) of well-dispersed, purified and small SWCNTs did not alter the growth and pigment accumulation of the cultures. Indeed, under the photoinhibitory conditions of our experiments, SWCNT-enriched samples were characterized by a lower rate of PSII inactivation, reduced excitation pressure in PSII, a higher rate of photosynthetic electron transport, and an increased non-photochemical quenching in comparison with the controls. In addition, SWCNTs change the distribution of energy between the photosystems in favour of PSII (state 1). The underlying mechanism of this action is not yet understood but possibly, electrons or energy can be exchanged between the redox active nanotubes and photosynthetic components, and probably other redox active intra-chloroplast constituents. Alternatively, nanotubes may promote the formation of an NPQ conformation of PSII. Our results provided evidence for such electron/energy transfer from photosynthetic structures toward the nanotubes. The discovered photoprotective effects can potentially be used in photobiotechnology to maintain the photosynthetic activity of microorganisms under unfavourable conditions.

Estabilidad, función, alineación y lesiones asociadas después de una intervención quirúrgica y rehabilitación de fractura de platillos tibiales / Stability, function, alignment and associated injuries after surgical intervention and rehabilitation of tibial plate fracture

Resumen: Introducción: las fracturas de los platillos tibiales afectan la funcionalidad de una gran articulación de carga como la rodilla debido a sus múltiples compromisos no sólo articulares, sino también de tejidos blandos. Este estudio tiene como objetivo evaluar la estabilidad, función, alineación, lesiones asociadas y complicaciones de la rodilla después de intervención quirúrgica y rehabilitación de fractura de platillos tibiales. Material y métodos: se realizó estudio observacional prospectivo descriptivo, donde se incluyeron los pacientes con fractura de platillos tibiales intervenidos quirúrgicamente que cumplieran los criterios de inclusión en el período comprendido entre Abril de 2018 y Junio de 2019. Se hizo análisis de variables con pruebas t para muestras independientes. Resultados: de un total de 92 pacientes con fractura de platillos tibiales, 66 (71%) lograron completar los seis meses mínimos de seguimiento. La fractura más común según la clasificación de Schatzker fue tipo II con 33.3% y la más común según la clasificación de Luo fue la de tres columnas medial, lateral y posterior con 39.4%. Más de 70% de los pacientes intervenidos por fracturas de platillos tibiales presentaron lesión de tejidos blandos, por ende, una inestabilidad de rodilla, especialmente con mayor índice de lesiones del ligamento cruzado anterior e inestabilidad anterior. Conclusión: una proporción importante de los pacientes intervenidos por fractura de platillos tibiales tienen lesión ligamentaria de rodilla.

Abstract: Introduction: tibial plateau fractures affect functionality of a large load bearing joint such as the knee, due to its multiple compromises, not only articular but also the ones including soft tissues. This study aims to evaluate the stability, function, alignment, associated injuries and complications of the knee after surgery and tibial plateau fractures rehabilitation. Material and methods: a descriptive prospective observational study was carried out where patients with a tibial plateau fracture who had undergone surgery, that accomplish the inclusion criteria were included, in the period from April 2018 to June 2019. Analysis of variables was performed with t tests for independent samples. Results: from a total of 92 patients with tibial plateau fracture, 66 (71%) were able to achieve the minimum six months follow-up. The most common fracture according to Schatzker classification was type II with 33.3%, and the most common according to Luo classification was the medial, lateral and posterior three column with 39.4%. More than 70% of patients who underwent surgery due to tibial plateau fractures developed soft tissue injury, therefore knee instability, specially with a higher rate of anterior cruciate ligament injuries or anterior instability. Conclusion: an important proportion of patients who underwent surgery for tibial plateau fractures have knee ligament injuries.

Aberrant cortical development is driven by impaired cell cycle and translational control in a DDX3X syndrome model.

Mutations in the RNA helicase, DDX3X, are a leading cause of Intellectual Disability and present as DDX3X syndrome, a neurodevelopmental disorder associated with cortical malformations and autism. Yet, the cellular and molecular mechanisms by which DDX3X controls cortical development are largely unknown. Here, using a mouse model of Ddx3x loss-of-function we demonstrate that DDX3X directs translational and cell cycle control of neural progenitors, which underlies precise corticogenesis. First, we show brain development is sensitive to Ddx3x dosage; complete Ddx3x loss from neural progenitors causes microcephaly in females, whereas hemizygous males and heterozygous females show reduced neurogenesis without marked microcephaly. In addition, Ddx3x loss is sexually dimorphic, as its paralog, Ddx3y, compensates for Ddx3x in the developing male neocortex. Using live imaging of progenitors, we show that DDX3X promotes neuronal generation by regulating both cell cycle duration and neurogenic divisions. Finally, we use ribosome profiling in vivo to discover the repertoire of translated transcripts in neural progenitors, including those which are DDX3X-dependent and essential for neurogenesis. Our study reveals invaluable new insights into the etiology of DDX3X syndrome, implicating dysregulated progenitor cell cycle dynamics and translation as pathogenic mechanisms.

During development, a complex network of genes ensures that the brain develops in the right way. In particular, they control how special 'progenitor' cells multiply and mature to form neurons during a process known as neurogenesis. Genetic mutations that interfere with neurogenesis can lead to disability and defects such as microcephaly, where children are born with abnormally small brains. DDX3X syndrome is a recently identified condition characterised by intellectual disability, delayed acquisition of movement and language skills, low muscle tone and, frequently, a diagnosis of autism spectrum disorder. It emerges when certain mutations are present in the DDX3X gene, which helps to control the process by which proteins are built in a cell (also known as translation). The syndrome affects girls more often than boys, potentially because DDX3X is carried on the X chromosome. Many of the disease-causing mutations in the DDX3X gene also reduce the levels of DDX3X protein. However, exactly what genes DDX3X controls and how its loss impairs brain development remain poorly understood. To address this problem, Hoye et al. set out to investigate the role of Ddx3x in mice neurogenesis. Experiments with genetically altered mice confirmed that complete loss of the gene indeed caused severe reduction in brain size at birth; just as in humans with mild microcephaly, this was only present in affected females. Further genetic studies revealed the reason for this: the closely related Ddx3y gene, which is only present on the Y (male) chromosome, helped to compensate for the loss of Ddx3x in the male mice. Next, the effect of the loss of just one copy of Ddx3x on neurogenesis was examined by following how progenitor cells developed. This likely reflects DDX3X levels in patients with the syndrome. Loss of the gene made the cells divide more slowly and produce fewer mature nerve cells, suggesting that smaller brain size and brain malformations caused by mutations in DDX3X could be due to impaired neurogenesis. Finally, a set of further biochemical and genetic experiments revealed a key set of genes that are under the control of the DDX3X protein. These results shed new light on how a molecular actor which helps to control translation is a key part of normal brain development. This understanding could one day help improve clinical management or treatments for DDX3X syndrome and related neurological disorders.

No unión infectada de fractura subtrocantérica de fémur, tratada con autoinjerto y placa / No infected union of subtrochanteric fracture of femur, treated with autograft and plate

Resumen: Las fracturas de cadera se consideran un problema de salud pública en el mundo, entre las fracturas de cadera encontramos las subtrocantéricas, que se definen como fracturas proximales de fémur situadas en la región trocantérea dentro de los 5 cm debajo del trocánter menor; tienen una incidencia aproximada de 15 a 20 por cada 100,000 personas. El objetivo de este de caso es reportar el éxito de la reconstrucción de una fractura subtrocantérica infectada, con un segmento del peroné no vascularizado y una placa de soporte condíleo de fémur distal. Caso clínico: masculino de 41 años de edad que sufre fractura subtrocantérica derecha producto de un accidente de tránsito que requirió manejo de osteosíntesis. Con posterior ruptura del clavo cefalomedular en su tercio proximal, no unión de la fractura e infecciones en sitio de la fractura. Fue tratado con múltiples lavados quirúrgicos, antibioticoterapia y un procedimiento ortopédico y quirúrgico poco convencional como el uso de una placa de soporte condíleo de fémur distal y un injerto óseo endomedular con un segmento de 10 cm de peroné no vascularizado. Paciente con evolución satisfactoria y favorable.

Abstract: Hip fractures are considered a public health problem in the world. Among hip fractures we find subtrochanteric fractures that are defined as proximal femur fractures located in the trochanteric region within 5 cm below the lesser trochanter; and they have an approximate incidence of 15 to 20 per 100,000 people. The objective of this case is to report the success of the reconstruction of an infected subtrochanteric fracture, with a non-vascularized fibular segment and a distal femur condylar support plate. Clinical case: 41-year-old male patient suffering from a right subtrochanteric fracture as a result of a traffic accident that required the use of osteosynthesis material. With subsequent rupture of the cephalomedullary nail in its proximal third, non-union of the fracture and infections at the fracture site. He was treated with multiple surgical lavages, antibiotic therapy, and an unconventional orthopedic and surgical procedure, such as the use of a distal femur condylar support plate and an endomedullary bone graft with a 10-cm segment of non-vascularized fibula. Patient with satisfactory and favorable evolution.

Subacute Sclerosing Panencephalitis: Restricted Diffusion and Clinical Evolution.

Background: Subacute sclerosing panencephalitis (SSPE) is a rare entity characterized by a protracted course and progressive neurological deterioration. Objective: We present patterns of diffusion restriction in eight cases of SSPE, a seldom described imaging attribute. Methods: A retrospective analysis was performed on the clinical and neuroimaging data obtained from records of patients with proven SSPE. Patients whose magnetic resonance imaging (MRI) showed evidence of diffusion restriction were included in the analysis. MRI was performed on 3 T and 1.5-T clinical MR systems. Imaging characteristics were reviewed and tabulated by two neuroradiologists. Results: Eight SSPE patients (seven men, one woman; age range: 5-15 years; mean age: 11 years) diagnosed and managed at our institute were included in the analysis. Restricted diffusion was evident in the basal ganglia (n = 3), corpus callosum (n = 2), white matter (n = 2) and in bilateral middle cerebellar peduncles (MCP) (n = 2). One patient had diffusion restriction in the genu of the corpus callosum and bilateral frontal cortical white matter. None of the diffusion-restricted lesions showed contrast enhancement or susceptibility. Six cases fulfilled the diagnostic criteria for fulminant SSPE (fSSPE). The extent of neuroparenchymal involvement was greater in this subset of patients. Conclusions: Restricted diffusion in SSPE, hitherto infrequently described, can indeed occur in both grey and white matter structures and in both supratentorial and infratentorial compartments. Parenchymal diffusion restriction in SSPE possibly reflects an early time point in the clinical evolution. A greater extent of parenchymal diffusion restriction may portend a rapid downhill course, possibly qualifying for fSSPE.

[Stability, function, alignment and associated injuries after surgical intervention and rehabilitation of tibial plate fracture]. / Estabilidad, función, alineación y lesiones asociadas después de una intervención quirúrgica y rehabilitación de fractura de platillos tibiales.

INTRODUCTION: tibial plateau fractures affect functionality of a large load bearing joint such as the knee, due to its multiple compromises, not only articular but also the ones including soft tissues. This study aims to evaluate the stability, function, alignment, associated injuries and complications of the knee after surgery and tibial plateau fractures rehabilitation. MATERIAL AND METHODS: a descriptive prospective observational study was carried out where patients with a tibial plateau fracture who had undergone surgery, that accomplish the inclusion criteria were included, in the period from April 2018 to June 2019. Analysis of variables was performed with t tests for independent samples. RESULTS: from a total of 92 patients with tibial plateau fracture, 66 (71%) were able to achieve the minimum six months follow-up. The most common fracture according to Schatzker classification was type II with 33.3%, and the most common according to Luo classification was the medial, lateral and posterior three column with 39.4%. More than 70% of patients who underwent surgery due to tibial plateau fractures developed soft tissue injury, therefore knee instability, specially with a higher rate of anterior cruciate ligament injuries or anterior instability. CONCLUSION: an important proportion of patients who underwent surgery for tibial plateau fractures have knee ligament injuries.

INTRODUCCIÓN: las fracturas de los platillos tibiales afectan la funcionalidad de una gran articulación de carga como la rodilla debido a sus múltiples compromisos no sólo articulares, sino también de tejidos blandos. Este estudio tiene como objetivo evaluar la estabilidad, función, alineación, lesiones asociadas y complicaciones de la rodilla después de intervención quirúrgica y rehabilitación de fractura de platillos tibiales. MATERIAL Y MÉTODOS: se realizó estudio observacional prospectivo descriptivo, donde se incluyeron los pacientes con fractura de platillos tibiales intervenidos quirúrgicamente que cumplieran los criterios de inclusión en el período comprendido entre Abril de 2018 y Junio de 2019. Se hizo análisis de variables con pruebas t para muestras independientes. RESULTADOS: de un total de 92 pacientes con fractura de platillos tibiales, 66 (71%) lograron completar los seis meses mínimos de seguimiento. La fractura más común según la clasificación de Schatzker fue tipo II con 33.3% y la más común según la clasificación de Luo fue la de tres columnas medial, lateral y posterior con 39.4%. Más de 70% de los pacientes intervenidos por fracturas de platillos tibiales presentaron lesión de tejidos blandos, por ende, una inestabilidad de rodilla, especialmente con mayor índice de lesiones del ligamento cruzado anterior e inestabilidad anterior. CONCLUSIÓN: una proporción importante de los pacientes intervenidos por fractura de platillos tibiales tienen lesión ligamentaria de rodilla.

[No infected union of subtrochanteric fracture of femur, treated with autograft and plate]. / No unión infectada de fractura subtrocantérica de fémur, tratada con autoinjerto y placa.

Hip fractures are considered a public health problem in the world. Among hip fractures we find subtrochanteric fractures that are defined as proximal femur fractures located in the trochanteric region within 5 cm below the lesser trochanter; and they have an approximate incidence of 15 to 20 per 100,000 people. The objective of this case is to report the success of the reconstruction of an infected subtrochanteric fracture, with a non-vascularized fibular segment and a distal femur condylar support plate. Clinical case: 41-year-old male patient suffering from a right subtrochanteric fracture as a result of a traffic accident that required the use of osteosynthesis material. With subsequent rupture of the cephalomedullary nail in its proximal third, non-union of the fracture and infections at the fracture site. He was treated with multiple surgical lavages, antibiotic therapy, and an unconventional orthopedic and surgical procedure, such as the use of a distal femur condylar support plate and an endomedullary bone graft with a 10-cm segment of non-vascularized fibula. Patient with satisfactory and favorable evolution.

Las fracturas de cadera se consideran un problema de salud pública en el mundo, entre las fracturas de cadera encontramos las subtrocantéricas, que se definen como fracturas proximales de fémur situadas en la región trocantérea dentro de los 5 cm debajo del trocánter menor; tienen una incidencia aproximada de 15 a 20 por cada 100,000 personas. El objetivo de este de caso es reportar el éxito de la reconstrucción de una fractura subtrocantérica infectada, con un segmento del peroné no vascularizado y una placa de soporte condíleo de fémur distal. Caso clínico: masculino de 41 años de edad que sufre fractura subtrocantérica derecha producto de un accidente de tránsito que requirió manejo de osteosíntesis. Con posterior ruptura del clavo cefalomedular en su tercio proximal, no unión de la fractura e infecciones en sitio de la fractura. Fue tratado con múltiples lavados quirúrgicos, antibioticoterapia y un procedimiento ortopédico y quirúrgico poco convencional como el uso de una placa de soporte condíleo de fémur distal y un injerto óseo endomedular con un segmento de 10 cm de peroné no vascularizado. Paciente con evolución satisfactoria y favorable.

Defective oogenesis in mice with pristane-induced model of systemic lupus.

Systemic lupus erythematosus (SLE) is a chronic systemic autoimmune disease characterized by generation of autoantibodies and severe damage of various organs. The hormonal changes associated with pregnancy and especially estrogen might lead to damage of reproductive function and ovarian quality. We employed a pristane-induced lupus model of Balb/c mice which resembles human lupus in an attempt to follow oogenesis disruption during the disease progression. The integrity of cytoskeletal and chromatin structures was estimated in oocytes derived by hormonally stimulated ovulation in lupus mice and the results were compared with those from healthy mice. Chromatin, tubulin and actin structures in oocytes were detected by Hoechst 33258, anti-alpha-tubulin antibody and rhodamine-labeled phalloidin, respectively. All available meiotic spindles were analyzed - in immature (metaphase I) and mature oocytes (metaphase II). The total number of mature oocytes obtained from lupus mice was lower compared to healthy controls. The maturation rate was 9.8 % for lupus mice, 12.7 % for 7-month old controls, and 14.3 % for the young control mice (4 weeks old). Another major difference between the studied groups was the higher percentage of defective metaphase I spindles registered in oocytes derived from lupus mice (60 % normal spindles), while for the young and older controls this proportion was 86 % and 81 %, respectively. No such difference was registered for metaphase II spindles. For both metaphase I and metaphase II oocytes, the proportions of normal actin cap and chromosomal condensation were similar between the experimental groups.

Adaptations for Pressure and Temperature in Dihydrofolate Reductases.

Enzymes from extremophilic microbes that live in extreme conditions are generally adapted so that they function under those conditions, although adaptations for extreme temperatures and pressures can be difficult to unravel. Previous studies have shown mutation of Asp27 in Escherichia coli dihydrofolate reductase (DHFR) to Glu27 in Moritella profunda (Mp). DHFR enhances activity at higher pressures, although this may be an adaptation for cold. Interestingly, MpDHFR unfolds at ~70 MPa, while Moritella yayanosii (My) was isolated at depths corresponding to ~110 MPa, indicating that MyDHFR might be adapted for higher pressures. Here, these adaptations are examined using molecular dynamics simulations of DHFR from different microbes in the context of not only experimental studies of activity and stability of the protein but also the evolutionary history of the microbe. Results suggest Tyr103 of MyDHFR may be an adaptation for high pressure since Cys103 in helix F of MpDHFR forms an intra-helix hydrogen bond with Ile99 while Tyr103 in helix F of MyDHFR forms a hydrogen bond with Leu78 in helix E. This suggests the hydrogen bond between helices F and E in MyDHFR might prevent distortion at higher pressures.

How adding a single methylene to dihydrofolate reductase can change its conformational dynamics.

Studies of the effects of pressure on proteins from piezophilic (pressure-loving) microbes compared with homologous proteins from mesophilic microbes have been relatively rare. Interestingly, such studies of dihydrofolate reductase show that a single-site mutation from an aspartic acid to a glutamic acid can reverse the pressure-dependent monotonic decrease in activity to that in a monotonic pressure-dependent activation. This residue is near the active site but is not thought to directly participate in the catalytic mechanism. Here, the ways that addition of one carbon to the entire protein could lead to such a profound difference in pressure effects are explored using molecular dynamics simulations. The results indicate that the glutamate changes the coupling between a helix and the ß-sheet due to the extra flexibility of the side chain, which further changes correlated motions of other regions of the protein.