Early Cretaceous lepidosaur (sphenodontian?) burrows.

Scarce fossil tetrapod burrows have been recorded in Cretaceous rocks, which is probably linked to the dominant equable climates that existed for most of this period. The occurrence of Cretaceous tetrapod burrows from Patagonia (Chubut Province, Argentina) dated between 118 and 115 million years ago, gives insights into their paleoecology and paleoenvironment. The rocks containing the tetrapod burrows are of pyroclastic origin and represent eolian dunes and ash-fall deposits, some reworked by fluvial currents and others showing soil development. Fossil burrow casts preserved in a paleosol are composed by a ramp with a slightly curved or straight path in plan-view and lacking bifurcation, a rounded termination with no enlargement, showing a reniform cross-section, and are assigned to the ichnospecies Reniformichnus katikatii. The strongly flattened cross-sectional shape of the burrow casts and comparison with modern lizard burrows suggest that the producers were lepidosaurs (body mass = 50-323 g). Among Cretaceous fossorial lepidosaurs from Patagonia, the best candidate is an eilenodontine sphenodontian. Sphenodontians burrowed in the fossil soils where also arthropods, earthworms and shrubby plants thrived. The rare occurrence of tetrapod burrows in Cretaceous rocks is linked to stressing conditions related to frequent arrival of volcanic ash and a semiarid seasonal climate.

Polineuropatía por amiloidosis por transtiretina de inicio tardío. Caso clínico / Late-onset hereditary transthyretin amyloidosis with polyneuropathy. Report of one case

Hereditary transthyretin amyloidosis is a multisystemic autosomal dominant genetic disorder characterized by progressive distal sensory-motor polyneuropathy or restrictive cardiomyopathy, secondary to amyloid deposits. Its pathogenesis lies in the TTR gene mutation, and the Val50Met mutation is the most frequent. Patients have significant differences in the onset and severity of clinical presentation according to their country of origin. The diagnosis of this pathology is complex, even more in countries where it is not considered endemic. However, early suspicion and management are essential to improve survival and avoid unnecessary diagnostic and therapeutic strategies. We report a 69-year-old woman who presented a sensory-motor polyneuropathy, predominantly sensory, associated with distal neuropathic pain and bilateral vitritis. The history of her Italian father with polyneuropathy of unspecified etiology stood out. A vitreous biopsy identified amyloid substance deposits (congo red positive). These were also confirmed on a superficial peroneal nerve biopsy. During the etiological study of her polyneuropathy, an increased Kappa/Lambda index of 2.55 mg/L stood out. Therefore, light chain amyloidosis was suspected, and chemotherapy treatment was indicated without favorable response. After 10 years of progressive neurological and ophthalmological involvement, a genetic study confirmed the first case of late-onset hereditary transthyretin amyloidosis Val50Met with polyneuropathy in Chile.

Advances and Perspectives for Polyploidy Breeding in Orchids.

The orchid market is a dynamic horticultural business in which novelty and beauty command high prices. The two main interests are the development of flowers, from the miniature to the large and showy, and their fragrance. Overall organ size might be modified by doubling the chromosome number, which can be accomplished by careful study of meiotic chromosome disjunction in hybrids or species. Meiosis is the process in which diploid (2n) pollen mother cells recombine their DNA sequences and then undergo two rounds of division to give rise to four haploid (n) cells. Thus, by interfering in chromosome segregation, one can induce the development of diploid recombinant cells, called unreduced gametes. These unreduced gametes may be used for breeding polyploid progenies with enhanced fertility and large flower size. This review provides an overview of developments in orchid polyploidy breeding placed in the large context of meiotic chromosome segregation in the model plants Arabidopsis thaliana and Brassica napus to facilitate molecular translational research and horticultural innovation.

Effects of the economic recession on suicide mortality in Brazil: interrupted time series analysis.

OBJECTIVES: to analyze trends in suicide rates in Brazil in the period before and after the start of the economic recession. METHODS: interrupted time series research using national suicide data recorded in the period between 2012 and 2017 with socioeconomic subgroups analyses. Quasi-Poisson regression model was employed to analyze trends in seasonally adjusted data. RESULTS: there was an abrupt increase in the risk of suicide after economic recession in the population with less education (12.5%; RR = 1.125; 95%CI: 1.027; 1.232) and in the South Region (17.7%; 1.044; 1.328). After an abrupt reduction, there was a progressive increase in risk for the black and brown population and for those with higher education. In most other population strata, there was a progressive increase in the risk of suicide. CONCLUSIONS: the Brazilian economic recession caused different effects on suicide rates, considering social strata, which requires health strategies and policies that are sensitive to the most vulnerable populations.

[Late-onset hereditary transthyretin amyloidosis with polyneuropathy. Report of one case]. / Polineuropatía por amiloidosis por transtiretina de inicio tardío. Caso clínico.

Hereditary transthyretin amyloidosis is a multisystemic autosomal dominant genetic disorder characterized by progressive distal sensory-motor polyneuropathy or restrictive cardiomyopathy, secondary to amyloid deposits. Its pathogenesis lies in the TTR gene mutation, and the Val50Met mutation is the most frequent. Patients have significant differences in the onset and severity of clinical presentation according to their country of origin. The diagnosis of this pathology is complex, even more in countries where it is not considered endemic. However, early suspicion and management are essential to improve survival and avoid unnecessary diagnostic and therapeutic strategies. We report a 69-year-old woman who presented a sensory-motor polyneuropathy, predominantly sensory, associated with distal neuropathic pain and bilateral vitritis. The history of her Italian father with polyneuropathy of unspecified etiology stood out. A vitreous biopsy identified amyloid substance deposits (congo red positive). These were also confirmed on a superficial peroneal nerve biopsy. During the etiological study of her polyneuropathy, an increased Kappa/Lambda index of 2.55 mg/L stood out. Therefore, light chain amyloidosis was suspected, and chemotherapy treatment was indicated without favorable response. After 10 years of progressive neurological and ophthalmological involvement, a genetic study confirmed the first case of late-onset hereditary transthyretin amyloidosis Val50Met with polyneuropathy in Chile.

Effects of the economic recession on suicide mortality in Brazil: interrupted time series analysis / Efectos de la recesión económica en la mortalidad por suicidio en Brasil: análisis de series de tiempo interrumpido / Efeitos da recessão econômica na mortalidade por suicídio no Brasil: análise com séries temporais interrompidas

ABSTRACT Objectives: to analyze trends in suicide rates in Brazil in the period before and after the start of the economic recession. Methods: interrupted time series research using national suicide data recorded in the period between 2012 and 2017 with socioeconomic subgroups analyses. Quasi-Poisson regression model was employed to analyze trends in seasonally adjusted data. Results: there was an abrupt increase in the risk of suicide after economic recession in the population with less education (12.5%; RR = 1.125; 95%CI: 1.027; 1.232) and in the South Region (17.7%; 1.044; 1.328). After an abrupt reduction, there was a progressive increase in risk for the black and brown population and for those with higher education. In most other population strata, there was a progressive increase in the risk of suicide. Conclusions: the Brazilian economic recession caused different effects on suicide rates, considering social strata, which requires health strategies and policies that are sensitive to the most vulnerable populations.

RESUMEN Objetivos: analizar tendencias de tasas de suicidio en Brasil, antes y después del inicio de la recesión económica. Métodos: estudio de series de tiempo interrumpido utilizando datos nacionales de suicidio registrados entre 2012 y 2017 con análisis por subgrupos socioeconómicos. Modelo de regresión quasi-Poisson empleado para analizar tendencias de datos ajustados estacionalmente. Resultados: observado aumento abrupto en el riesgo de suicidio pos recesión económica en la población con menor escolaridad (12,5%; RR = 1,125; IC95%:1,027; 1,232) y en la Región Sur (17,7%; 1,044; 1,328). Pos reducción abrupta, ocurrió aumento progresivo en el riesgo para la población de negros y pardos y de mayor escolaridad. En la mayoría de los demás estratos poblacionales, verificado aumento progresivo en el riesgo de suicidio. Conclusiones: la recesión económica brasileña produzco efectos diferentes en las tasas de suicidio, considerando los estratos sociales, lo que demanda estrategias de salud y políticas sensibles a poblaciones más vulnerables.

RESUMO Objetivos: analisar as tendências nas taxas de suicídio no Brasil, no período antes e depois do início da recessão econômica. Métodos: estudo de séries temporais interrompidas utilizando dados nacionais de suicídio registrados no período entre 2012 e 2017 com análises por subgrupos socioeconômicos. Modelo de regressão quasi-Poisson foi empregado para analisar as tendências dos dados ajustados sazonalmente. Resultados: observou-se aumento abrupto no risco de suicídio após recessão econômica na população com menor escolaridade (12,5%; RR = 1,125; IC95%:1,027; 1,232) e na Região Sul (17,7%; 1,044; 1,328). Após redução abrupta, ocorreu aumento progressivo no risco para a população de pretos e pardos e na de maior escolaridade. Na maioria dos demais estratos populacionais, verificou-se aumento progressivo no risco de suicídio. Conclusões: a recessão econômica brasileira produziu efeitos diferentes nas taxas de suicídio, considerando os estratos sociais, o que demanda estratégias de saúde e políticas sensíveis às populações mais vulneráveis.

The Role of Structural Maintenance of Chromosomes Complexes in Meiosis and Genome Maintenance: Translating Biomedical and Model Plant Research Into Crop Breeding Opportunities.

Cohesin is a multi-unit protein complex from the structural maintenance of chromosomes (SMC) family, required for holding sister chromatids together during mitosis and meiosis. In yeast, the cohesin complex entraps sister DNAs within tripartite rings created by pairwise interactions between the central ring units SMC1 and SMC3 and subunits such as the α-kleisin SCC1 (REC8/SYN1 in meiosis). The complex is an indispensable regulator of meiotic recombination in eukaryotes. In Arabidopsis and maize, the SMC1/SMC3 heterodimer is a key determinant of meiosis. In Arabidopsis, several kleisin proteins are also essential: SYN1/REC8 is meiosis-specific and is essential for double-strand break repair, whereas AtSCC2 is a subunit of the cohesin SCC2/SCC4 loading complex that is important for synapsis and segregation. Other important meiotic subunits are the cohesin EXTRA SPINDLE POLES (AESP1) separase, the acetylase ESTABLISHMENT OF COHESION 1/CHROMOSOME TRANSMISSION FIDELITY 7 (ECO1/CTF7), the cohesion release factor WINGS APART-LIKE PROTEIN 1 (WAPL) in Arabidopsis (AtWAPL1/AtWAPL2), and the WAPL antagonist AtSWITCH1/DYAD (AtSWI1). Other important complexes are the SMC5/SMC6 complex, which is required for homologous DNA recombination during the S-phase and for proper meiotic synapsis, and the condensin complexes, featuring SMC2/SMC4 that regulate proper clustering of rDNA arrays during interphase. Meiotic recombination is the key to enrich desirable traits in commercial plant breeding. In this review, I highlight critical advances in understanding plant chromatid cohesion in the model plant Arabidopsis and crop plants and suggest how manipulation of crossover formation during meiosis, somatic DNA repair and chromosome folding may facilitate transmission of desirable alleles, tolerance to radiation, and enhanced transcription of alleles that regulate sexual development. I hope that these findings highlight opportunities for crop breeding.

Analysis of Meiosis in Nonmodel Tropical Plants: The Case of Carica papaya Linn.

To develop plants that are more tolerant to drought, marginal soil fertility, and diseases and that satisfy demands for high yield, new cultivars of the tropical fruit papaya (Carica papaya L.) are needed. Nonetheless, in many cases, these traits are available in only wild relatives found throughout Latin America. Understanding meiotic progression may facilitate the introgression of desirable traits into commercial cultivars that maintain high fertility. In this protocol, we describe a practical and simple method to effectively isolate male meiocytes in order to document the behavior of papaya meiotic chromosomes.

Meiosis Research in Orphan and Non-orphan Tropical Crops.

Plant breeding is directly linked to the development of crops that can effectively adapt to challenging conditions such as soil nutrient depletion, water pollution, drought, and anthropogenic climate change. These conditions are extremely relevant in developing countries already burdened with population growth and unchecked urban expansion, especially in the tropical global southern hemisphere. Engineering new crops thus has potential to enhance food security, prevent hunger, and spur sustainable agricultural growth. A major tool for the improvement of plant varieties in this context could be the manipulation of homologous recombination and genome haploidization during meiosis. The isolation or the design of mutations in key meiotic genes may facilitate DNA recombination and transmission of important genes quickly and efficiently. Genome haploidization through centromeric histone mutants could be an option to create new crosses rapidly. This review covers technical approaches to engineer key meiotic genes in tropical crops as a blueprint for future work and examples of tropical crops in which such strategies could be applied are given.

Clinical features and possible founder mutation of the 8bp duplication mutation in the SLC4A11 gene causing corneal dystrophy and perceptive deafness in three South American families.

BACKGROUND: Corneal Dystrophy and Perceptive Deafness (CDPD) or Harboyan syndrome is an autosomal recessive rare disorder, characterized by congenital corneal opacities and progressive sensorineural hearing loss, which usually begins after the second decades of life. This study reports the ophthalmic, audiological and genetic features, in five CDPD affected patients from three Chilean families. MATERIALS AND METHODS: Five individuals affected with CDPD from three unrelated Chilean families were clinically and genetically examined. To evaluate a putative founder mutation 7 SNPs were analyzed in the three families, an Argentinian patient (carrier of the same mutation previously reported) and 87 Chilean controls. RESULTS: The ophthalmic symptoms in the five patients were bilateral and symmetric, starting before one year of age, and visual acuity varied from 0.1 to 0.3. In all cases, hearing loss began over 8 years old. The sequence of the 19 exons of SLC4A11 gene of all the affected patients exhibited homozygous eight nucleotide sequence duplication (c.2233_2240dup TATGACAC, p.(Ile748Metfs*5)) at the end of exon 16. All the affected patients of the three families were homozygous for a haplotype composed of five SNPs and covering 4,1 Mb. The same haplotype was present in one allele of the heterozygous Argentinean patient and has a frequency of 2.76% in Chilean population. CONCLUSIONS: The five CDPD patients were homozygous for the same mutation in the SLC4A11 gene. Haplotype analysis of all the affected, including the case reported from Argentina was in accordance with a founder mutation.

[Toxic epidermal necrolysis during a hemophagocytic syndrome secondary to Hodgkin lymphoma. Report of one case]. / Necrolisis epidérmica tóxica en el curso de un síndrome hemofagocítico secundario a linfoma de Hodgkin. Caso clínico.

Toxic epidermal necrolysis (TEN) is a lethal entity, characterized by extensive epidermal necrosis and multiorgan failure. Hemophagocytic syndrome (HFS) is also a rare and lethal syndrome characterized by hyperinflammation that leads to the appearance of fever, pancytopenia, organomegaly and hemophagocytosis. The concomitance of these diseases is extremely uncommon. We report a 38 years old female, who during the course of a HFS secondary to Hodgkin Lymphoma (HL), presented a TEN secondary to antibiotics. She was admitted due to a consumptive syndrome, lymphadenopathy, visceromegaly and severe pancytopenia. Laboratory and bone marrow tests confirmed HFS. Due to constant fever, imipenem was indicated. On the third day she started with pain and skin rash. She evolved with positive Nikolsky sign. Cutaneous biopsy was concordant with extensive TEN, which was managed with intravenous immunoglobulin and dexamethasone. A complete response and normalization of the blood count were achieved. Finally, the lymph node biopsy showed HL of mixed cellularity type, which was managed with 8 cycles of ABVD chemotherapy, achieving complete remission.

Necrolisis epidérmica tóxica en el curso de un síndrome hemofagocítico secundario a linfoma de Hodgkin: caso clínico / Toxic epidermal necrolysis during a hemophagocytic syndrome secondary to Hodgkin lymphoma: report of one case

Toxic epidermal necrolysis (TEN) is a lethal entity, characterized by extensive epidermal necrosis and multiorgan failure. Hemophagocytic syndrome (HFS) is also a rare and lethal syndrome characterized by hyperinflammation that leads to the appearance of fever, pancytopenia, organomegaly and hemophagocytosis. The concomitance of these diseases is extremely uncommon. We report a 38 years old female, who during the course of a HFS secondary to Hodgkin Lymphoma (HL), presented a TEN secondary to antibiotics. She was admitted due to a consumptive syndrome, lymphadenopathy, visceromegaly and severe pancytopenia. Laboratory and bone marrow tests confirmed HFS. Due to constant fever, imipenem was indicated. On the third day she started with pain and skin rash. She evolved with positive Nikolsky sign. Cutaneous biopsy was concordant with extensive TEN, which was managed with intravenous immunoglobulin and dexamethasone. A complete response and normalization of the blood count were achieved. Finally, the lymph node biopsy showed HL of mixed cellularity type, which was managed with 8 cycles of ABVD chemotherapy, achieving complete remission.

High CD8+ and absence of Foxp3+ T lymphocytes infiltration in gallbladder tumors correlate with prolonged patients survival.

BACKGROUND: Gallbladder cancer (GBC), although infrequent in industrialized countries, has high incidence rates in certain world regions, being a leading cause of death among elderly Chilean women. Surgery is the only effective treatment, and a five-year survival rate of advanced-stage patients is less than 10%. Hence, exploring immunotherapy is relevant, although GBC immunogenicity is poorly understood. This study examined the relationship between the host immune response and GBC patient survival based on the presence of tumor-infiltrating lymphocytes at different disease stages. METHODS: Tumor tissues from 80 GBC patients were analyzed by immunohistochemistry for the presence of CD3+, CD4+, CD8+, and Foxp3+ T cell populations, and the results were associated with clinical stage and patient survival. RESULTS: The majority of tumor samples showed CD3+ T cell infiltration, which correlated with better prognosis, particularly in advanced disease stages. CD8+, but not CD4+, T cell infiltration correlated with improved survival, particularly in advanced disease stages. Interestingly, a < 1 CD4+/CD8+ T cell ratio was related with increased survival. Additionally, the presence of Foxp3+ T cells correlated with decreased patient survival, whereas a ≤ 1 Foxp3+/CD8+ T cell ratio was associated with improved patient survival. CONCLUSIONS: Depending on the disease stage, the presence of CD8+ and absence of Foxp3+ T cell populations in tumor tissues correlated with improved GBC patient survival, and thus represent potential markers for prognosis and management of advanced disease, and supports testing of immunotherapy.

Insights Into the Role of Ubiquitination in Meiosis: Fertility, Adaptation and Plant Breeding.

Ubiquitination is a post-translational modification process that plays a central role in protein degradation in eukaryotic cell cell division, including meiosis. This modification affects different cellular processes on a global scale by its pleiotropic ability to modify numerous proteins. Meiosis is essential for sexual reproduction and involves two rounds of nuclear division following a single round of DNA replication to produce haploid gametes. Unlike mitosis, meiosis has a unique prophase I, which involves homologous chromosome interaction including pairing, synapsis, recombination and segregation. Over the last several decades, molecular genetic studies have identified many proteins that participate in meiotic progression. In this review, we focus on the recent advances regarding the role of ubiquitination during plant meiotic cell cycle progression and recombination, especially the role played by the Anaphase-Promoting Complex and E3 ligases in modulating crossover formation and its impact on evolution and plant breeding.

Hipercalcemia, peak monoclonal y leucemización como presentación de un linfoma de células B de alto grado, con reordenamiento de MYC, BCL-2 y BCL-6 (Triple Hit). Caso clínico / Hypercalcemia, monoclonal peak and leukemic presentation of a High-grade B-cell lymphoma with MYC, BCL-2 and BCL-6 translocations (triple hit). Report of one case

High-grade B-cell lymphomas with rearrangement of MYC, BCL-2 and/or BCL-6 were introduced by the update of the WHO classification of lymphoid neoplasms. They usually present unique morphological and molecular characteristics, with an aggressive clinical outcome and worse prognosis. We report a 48 year-old female patient presenting with B symptoms and enlarged lymph nodes. Blood count showed pancytopenia and peripheral blood smears showed large lymphoid cells, some with nuclei and vacuoles. LDH was 3524 g/L and serum calcium was 11.5 mg/dL. Flow cytometry immunophenotyping showed pathological mature B lymphocytes. Protein electrophoresis showed a slight monoclonal peak. The biopsy disclosed a triple expressor diffuse large B-cell lymphoma, arising from germinal center. FISH was positive for MYC, BCL-2 and BCL-6 (triple hit) with a clonal evolution. Conventional cytogenetics showed a complex karyotype. Chemotherapy was started with R-CHOP (Rituximab/cyclophosphamide/doxorubicin/vincristine/prednisone). She developed impaired consciousness; the brain CT scan showed a large brain mass. The patient died within 3 weeks.

[Differential diagnosis of bone marrow and lung granulomas: Report of one case]. / Granulomas pulmonares y en médula ósea: más allá de la tuberculosis. A propósito de un caso.

The differential diagnosis of pulmonary tuberculosis and lymphoma with pulmonary infiltration is very difficult, given their similar clinical characteristics. We report a 59 year old female with weight loss, fever, dyspnea and cough of several months of duration. She had a cavitated mass in lung imaging. A positive conventional PCR lead to the diagnosis of tuberculosis, but she had negative smears and cultures for Mycobacterium tuberculosis. The patient did not respond to treatment and her clinical condition worsened. A peripheral lymph node biopsy confirmed the presence of a diffuse large B cell non-Hodgkin lymphoma. Bone marrow pathology showed non caseating granulomas, again with negative microbiological tests for M. tuberculosis. Findings in the bone marrow were interpreted as a secondary sarcoid reaction to cancer and PCR results as a false positive. The lymphoma was treated, achieving complete remission. This case highlights the importance of the differential diagnosis between these two entities.

In Favor of Establishment: Regulation of Chromatid Cohesion in Plants.

In eukaryotic organisms, the correct regulation of sister chromatid cohesion, whereby sister chromatids are paired and held together, is essential for accurate segregation of the sister chromatids and homologous chromosomes into daughter cells during mitosis and meiosis, respectively. Sister chromatid cohesion requires a cohesin complex comprised of structural maintenance of chromosome adenosine triphosphatases and accessory proteins that regulate the association of the complex with chromosomes or that are involved in the establishment or release of cohesion. The cohesin complex also plays important roles in the repair of DNA double-strand breaks, regulation of gene expression and chromosome condensation. In this review, we summarize progress in understanding cohesion dynamics in plants, with the aim of uncovering differences at specific stages. We also highlight dissimilarities between plants and other eukaryotes with respect to the key players involved in the achievement of cohesion, pointing out areas that require further study.

Granulomas pulmonares y en médula ósea: más allá de la tuberculosis. A propósito de un caso / Differential diagnosis of bone marrow and lung granulomas: Report of one case

The differential diagnosis of pulmonary tuberculosis and lymphoma with pulmonary infiltration is very difficult, given their similar clinical characteristics. We report a 59 year old female with weight loss, fever, dyspnea and cough of several months of duration. She had a cavitated mass in lung imaging. A positive conventional PCR lead to the diagnosis of tuberculosis, but she had negative smears and cultures for Mycobacterium tuberculosis. The patient did not respond to treatment and her clinical condition worsened. A peripheral lymph node biopsy confirmed the presence of a diffuse large B cell non-Hodgkin lymphoma. Bone marrow pathology showed non caseating granulomas, again with negative microbiological tests for M. tuberculosis. Findings in the bone marrow were interpreted as a secondary sarcoid reaction to cancer and PCR results as a false positive. The lymphoma was treated, achieving complete remission. This case highlights the importance of the differential diagnosis between these two entities.