Novel influenza A viruses in pigs with zoonotic potential, Chile.

Novel H1N2 and H3N2 swine influenza A viruses (IAVs) have recently been identified in Chile. The objective of this study was to evaluate their zoonotic potential. We perform phylogenetic analyses to determine the genetic origin and evolution of these viruses, and a serological analysis to determine the level of cross-protective antibodies in the human population. Eight genotypes were identified, all with pandemic H1N1 2009-like internal genes. H1N1 and H1N2 were the subtypes more commonly detected. Swine H1N2 and H3N2 IAVs had hemagglutinin and neuraminidase lineages genetically divergent from IAVs reported worldwide, including human vaccine strains. These genes originated from human seasonal viruses were introduced into the swine population since the mid-1980s. Serological data indicate that the general population is susceptible to the H3N2 virus and that elderly and young children also lack protective antibodies against the H1N2 strains, suggesting that these viruses could be potential zoonotic threats. Continuous IAV surveillance and monitoring of the swine and human populations is strongly recommended.IMPORTANCEIn the global context, where swine serve as crucial intermediate hosts for influenza A viruses (IAVs), this study addresses the pressing concern of the zoonotic potential of novel reassortant strains. Conducted on a large scale in Chile, it presents a comprehensive account of swine influenza A virus diversity, covering 93.8% of the country's industrialized swine farms. The findings reveal eight distinct swine IAV genotypes, all carrying a complete internal gene cassette of pandemic H1N1 2009 origin, emphasizing potential increased replication and transmission fitness. Genetic divergence of H1N2 and H3N2 IAVs from globally reported strains raises alarms, with evidence suggesting introductions from human seasonal viruses since the mid-1980s. A detailed serological analysis underscores the zoonotic threat, indicating susceptibility in the general population to swine H3N2 and a lack of protective antibodies in vulnerable demographics. These data highlight the importance of continuous surveillance, providing crucial insights for global health organizations.

Cross-protection of commercial vaccines against Chilean swine influenza A virus using the guinea pig model as a surrogate.

Influenza A virus poses a significant threat to public health and the swine industry. Vaccination is the primary measure for controlling the disease, but the effectiveness of vaccines can vary depending on the antigenic match between vaccine strains and circulating strains. In Chile, H1N1pdm09 and other lineages H1N2 and H3N2 have been detected in pigs, which are genetically distinct from the strains included in commercial vaccines. This study aimed to evaluate the cross-protection by commercial vaccines against strains circulating in Chile using the guinea pig model. For this study, four circulating strains [A/swine/Chile/H1A-7/2014(H1N2), A/swine/Chile/H1B-2/2014(H1N2), A/swine/Chile/H1P-12/2015(H1N1), and A/swine/Chile/H3-2/2015(H3N2)] were selected. Guinea pigs were divided into vaccinated and control groups. The vaccinated animals received either a multivalent antigenically heterologous or monovalent homologous vaccine, while the control animals remained unvaccinated. Following vaccination, all animals were intranasally challenged, and nasal wash samples were collected at different time points post-infection. The results showed that the homologous monovalent vaccine-induced hemagglutinin-specific antibodies against the Chilean pandemic H1N1pdm09 strain. However, the commercial heterologous multivalent vaccine failed to induce hemagglutinin-specific antibody titers against the H1N2 and H3N2 challenge strains. Furthermore, the homologous monovalent vaccine significantly reduced the duration of viral shedding and viral titers specifically against the Chilean pandemic H1N1pdm09 strain and heterologous multivalent vaccine only partial. These findings highlight the importance of regularly updating vaccine strains to match the circulating field strains for effective control of swine influenza. Further research is needed to develop vaccines that confer broader protection against diverse strains of swine influenza A virus.

Cumplimiento de prescripción unidad terapia intensiva Hospital San Juan de Dios Tarija 4to. trimestre 2017 / Compliance with the prescription of the intensive care unit of the San Juan de Dios Hospital, Tarija, 4th. Quarter 2017

Antecedentes: La prescripción es responsabilidad médica, siendo una acción fundamental en el pronóstico de la enfermedad, entendiendo que esta acción generara una cadena de eventos en la Institución, familia y paciente. Se tomo criterios de evaluación establecidos en la Norma Técnica para el manejo del Expediente Clínico. Conclusiones: No existe asociación entre prescripción adecuada de antibióticos con las variables demográficas, laborales y académicas. Se debe incrementar la supervisión operativa encaminada al uso racional de medicamentos y cumplimiento de la normativa vigente.

Circulation patterns of human seasonal Influenza A viruses in Chile before H1N1pdm09 pandemic.

Understanding the diversity and circulation dynamics of seasonal influenza viruses is key to public health decision-making. The limited genetic information of pre-pandemic seasonal IAVs in Chile has made it difficult to accurately reconstruct the phylogenetic relationships of these viruses within the country. The objective of this study was to determine the genetic diversity of pre-pandemic human seasonal IAVs in Chile. We sequenced the complete genome of 42 historic IAV obtained between 1996 and 2007. The phylogeny was determined using HA sequences and complemented using other segments. Time-scale phylogenetic analyses revealed that the diversity of pre-pandemic human seasonal IAVs in Chile was influenced by continuous introductions of new A/H1N1 and A/H3N2 lineages and constant viral exchange between Chile and other countries every year. These results provide important knowledge about genetic diversity and evolutionary patterns of pre-pandemic human seasonal IAVs in Chile, which can help design optimal surveillance systems and prevention strategies. However, future studies with current sequences should be conducted.

COVID-19 in a country with a very high prevalence of diabetes: The impact of admission hyperglycaemia on mortality.

Aims: To evaluate the frequency of diabetes and admission hyperglycaemia in Mexican COVID-19 patients, to describe the clinical and biochemical characteristics of patients with admission hyperglycaemia and to determinate the impact of diabetes and admission hyperglycaemia on COVID-19 severity and mortality. Methods: A multicentric study was performed in 480 hospitalized patients with COVID-19. Clinical and biochemical characteristics were evaluated in patients with admission hyperglycaemia and compared with non-hyperglycaemic patients. The effect of diabetes and admission hyperglycaemia on severity and risk of death were evaluated. Results: Age was 50.7 ± 13.6 years; 68.3% were male. Some 48.5% (n = 233) had admission hyperglycaemia; 29% (n = 139) of these patients had pre-existing diabetes. Patients with admission hyperglycaemia had more requirement of invasive mechanical ventilation (IMV), higher levels of urea, D-dimer and neutrophil-lymphocyte ratio (NLR), as well as lower lymphocyte count. An association between admission hyperglycaemia with IMV and D-dimer with glucose was found. Age ≥50 years (OR 2.09; 95%CI 1.37-3.17), pre-existing diabetes (OR 2.38; 95%CI 1.59-5.04) and admission hyperglycaemia (OR 8.24; 95%CI 4.74-14.32) were risk factors for mortality. Conclusions: Admission hyperglycaemia is presented in 48.5% of COVID-19 patients. Diabetes and admission hyperglycaemia are associated with the severity of disease and mortality. This study shows the devastating conjunction of hyperglycaemia and COVID-19. Clinical trial registration: Clinical characteristics of patients with COVID-19, DI/20/204/04/41 (Hospital General de Mexico) and NR-13-2020 (Hospital Regional de Alta Especialidad Ixtapaluca).

Avian orthoavulavirus 1 (Newcastle Disease virus) antibodies in five penguin species, Antarctic peninsula and Southern Patagonia.

Avian orthoavulavirus 1 (AOaV-1) causes Newcastle disease, one of the most important and contagious infections in poultry, where migratory birds can play a key role as a reservoir. Seven hundred and seven serum samples were collected from five penguin species (King, Magellanic, Gentoo, Chinstrap and Adelie penguins) in the Antarctic and Sub-Antarctic zones. Using a competitive ELISA to detect antibodies against AOaV-1, we identified positive individuals in all penguin species. The Magellanic penguin showed the highest seropositivity rate (30.3%), suggesting it could be a natural reservoir of this virus. At the Antarctic zones, Chinstrap penguin showed the highest occurrence (7.5%). Interesting, positive sera was only obtained in Sub-Antarctic and Northern zones at the Antarctic peninsula, no seroreactivity was observed in Southern locations. Further studies are needed to establish the role of these penguin species in the epidemiology of the AOaV-1 and determine the effects of this virus in these populations.

Dímeros D e hiperglucemia y mortalidad en COVID-19 en un centro hospitalario de México / D-dimers, hyperglycemia and mortality in COVID-19 in a hospital in Mexico

Resumen Objetivo: Evaluar la asociación entre la concentración de glucosa al ingreso y los niveles circulantes de dímeros D en pacientes hospitalizados por enfermedad por coronavirus 2019 (COVID-19). Pacientes y métodos: Se estudiaron 187 pacientes hospitalizados por COVID-19. Se evaluaron las características bioquímicas, la concentración de glucosa y dímeros D, la gravedad de la enfermedad definida por la presencia de neumonía y/o insuficiencia respiratoria que ameritó ventilación mecánica invasiva (VMI) y la causa del egreso hospitalario. Resultados: La edad promedio de los pacientes fue 52 años, el 68% eran hombres, un 40.8% con obesidad y un 23.5% con hipertensión. Del total de pacientes hospitalizados, el 45.5% presentaba diabetes o hiperglucemia a la admisión. La concentración de proteína C reactiva y de dímeros D (1,134 [646.5-4,135.0] vs. 755 [548.7-1,780.0] ng/ml; p = 0.04] fue superior en pacientes con diabetes e hiperglucemia, en comparación con los pacientes con glucosa normal. Los pacientes que requirieron VMI presentaron también mayor concentración de dímeros D. Se observó una correlación directa entre las concentraciones de glucosa inicial y dímeros D (r: 0.239; p = 0.003). Conclusión: En los pacientes con COVID-19 el estado hiperglucémico se asocia directamente con un incremento de la concentración de dímeros D. Los resultados de este estudio deben conducir a insistir en el control glucémico como estrategia fundamental en los pacientes con COVID-19.

Abstract Objective: To evaluate the association between glucose level at admission and circulating levels of D-dimers in patients hospitalized for coronavirus disease 2019 (COVID-19). Methods: 187 patients hospitalized for COVID-19 were studied. Biochemical characteristics, glucose and D-dimers levels, severity of disease, defined by the presence of pneumonia and/or respiratory failure that required invasive mechanical ventilation (IVM) and the cause of hospital discharge were evaluated. Results: Age was 52 years, 68% were male, 40.8% with obesity and 23.5% with hypertension. Of the total of hospitalized patients, 45.5% had diabetes or hyperglycemia upon admission. Patients with diabetes and/or admission hyperglycemia had higher levels of protein C-reactive and D-dimers [(1134 (646.5-4135.0) vs. 755 (548.7-1780.0) ng/ml, p = 0.04], compared to patients with normal glucose level. Patients who required IMV also had a higher concentration of D-dimers. A correlation between glucose and D-dimers levels was evidenced (r=0.239, p=0.003). Conclusions: In patients with COVID-19, the hyperglycemic state is directly associated with an increase in the concentration of D-dimers and severity of disease. The results of this study should lead to insisting on glycemic control as a fundamental strategy in patients with COVID-19.

Influencia de la posición del terapeuta durante el aprendizaje motor por observación de la acción. Estudio piloto / Influence of the therapist's position during motor learning by observing the action. Pilot study

OBJETIVOS: bjetivo es hallar la posición más efectiva del terapeuta respecto al paciente para generar mayor aprendizaje motor por medio de la observación de la acción. MÉTODOS: diseñamos un modelo experimental simulando el entorno clínico de la terapia por observación de la acción y analizamos el aprendizaje de una tarea motora cotidiana desde diferentes perspectivas de observación en 60 personas sanas. RESULTADOS: obtuvimos diferencias de aprendizaje motor en los cuatro grupos estudiados. CONCLUSIONES: la perspectiva de observación en primera persona es mejor para adquirir habilidades motoras a corto plazo, aunque la observación en perspectiva opuesta puede obtener similares beneficios dependiendo de factores del contexto de la tarea, y la observación en perspectiva lateral, aunque es beneficiosa, obtiene menor aprendizaje que las anteriores

OBJECTIVE: To find the most effective position of the therapist with respect to the patient in order to generate greater motor learning through observing the action. METHODS: We designed an experimental model simulating the clinical environment of therapy by observation of the action and we analyzed the learning of a daily motor task from different observation perspectives in 60 healthy people. RESULTS: We obtained motor learning differences in the four groups studied. CONCLUSIONS: The perspective of first-person observation is better for acquiring short-term motor skills, although observation in opposite perspective can obtain similar benefits depending on factors of the task context, and observation in lateral perspective, although it is beneficial, obtains less learning than the previous ones

Antigenic characterization of novel H1 influenza A viruses in swine.

Novel H1N2 influenza A viruses (IAVs) in swine have been identified in Chile co-circulating with pandemic H1N1 2009-like (A(H1N1)pdm09-like) viruses. The objective of this study was to characterize antigenically the swine H1 IAVs circulating in Chile. Genetic analysis based on the HA1 domain and antigenic analysis by hemagglutination inhibition assay were carried out. Three antigenic clusters were identified, named Chilean H1 A (ChH1A), Chilean H1 B (ChH1B), and A(H1N1)pdm09-like. The antigenic sites of ChH1A and ChH1B strains were 10-60% distant from those of commercial vaccine strains at the amino acid sequence level. Antigenic variants were identified within the clusters ChH1A and A(H1N1)pdm09-like. Substitutions in the main antigenic sites (E153G in Sa, Q193H in Sb, D168N in Ca1, P137S in Ca2, and F71L in Cb) were detected in variants from the ChH1A cluster, whereas only a single substitution in antigenic site Sa (G155E) was detected in variants from A(H1N1)pdm09-like cluster, which confirms the importance to carrying out antigenic analyses in addition to genetic analyses to evaluate control measures such as vaccination. These results highlight the need to update vaccines for swine in Chile and the importance of continued surveillance to determine the onward transmission of antigenic variants in Chilean pig populations.

Novel penguin Avian avulaviruses 17, 18 and 19 are widely distributed in the Antarctic Peninsula.

Three novel Avian avulavirus species were discovered and isolated during 2017 from Gentoo penguins (Pygoscelis papua) at Kopaitic island in the Northwestern region of the Antarctic Peninsula. The viruses were officially named as Avian avulavirus 17 (AAV17), Avian avulavirus 18 (AAV18) and Avian avulavirus 19 (AAV19), collectively referred to as penguin avulaviruses (PAVs). To determine whether these viruses are capable of infecting the three species of Pygoscelis spp. penguins (Gentoo, Adelie and Chinstrap) and assess its geographical distribution, serum samples were collected from seven locations across the Antarctic Peninsula and Southern Shetland Islands. The samples were tested by Hemagglutination inhibition assay using reference viruses for AAV17, AAV18 and AAV19. A total of 498 sera were tested, and 40 were positive for antibodies against AAV17, 20 for AAV18 and 45 for AAV19. Positive sera were obtained for the penguin's species for each virus; however, antibodies against AAV18 were not identified in Adelie penguins. Positive penguins were identified in all regions studied. Positive locations include Ardley Island and Cape Shirreff at Livingston Island (Southern Shetland Region); Anvers Island, Doumer Island and Paradise Bay in the Central Western region; and Avian Island at Southwestern region of the Antarctic Peninsula. The lowest occurrence was observed at the Southwestern region at Lagotellerie Island, where all samples were negative. On the other hand, Cape Shirreff and Paradise Bay showed the highest antibody titres. Field samples did not evidence cross-reactivity between viruses, and detection was significantly higher for AAV19 and lower for AAV18. This is the first serologic study on the prevalence of the novel Avian avulaviruses including different locations in the white continent. The results indicate that these novel viruses can infect the three Pygoscelis spp. penguins, which extend across large distances of the Antarctic Peninsula.

Infection of novel reassortant H1N2 and H3N2 swine influenza A viruses in the guinea pig model.

Novel H1N2 and H3N2 swine influenza A viruses (IAVs) were identified in commercial farms in Chile. These viruses contained H1, H3 and N2 sequences, genetically divergent from IAVs described worldwide, associated with pandemic internal genes. Guinea pigs were used as human surrogate to evaluate the infection dynamics of these reassortant viruses, compared with a pandemic H1N1 virus. All viruses replicated and were shed in the upper respiratory tract without prior adaptation although H1N2 viruses showed the highest shedding titers. This could have public health importance, emphasizing the need to carry out further studies to evaluate the zoonotic potential of these viruses.

Genetic analysis of porcine circovirus type 2 from pigs affected with PMWS in Chile reveals intergenotypic recombination.

BACKGROUND: Porcine circovirus type 2 (PCV2) is a very small, non-enveloped and icosahedral virus, with circular single stranded DNA genome. This virus is the most ubiquitous and persistent pathogen currently affecting the swine industry worldwide. PCV2 has been implicated as the major causative agent of postweaning multisystemic wasting syndrome (PMWS), a disease which is characterized by severe immunosuppressive effects in the porcine host. Worldwide PCV2 isolates have been classified into four different genotypes, PCV2a, PCV2b, PCV2c and PCVd. The goal of this work was to conduct the first phylogenetic analysis of PCV2 in Chile. METHODS: PCV2 partial ORF2 sequences (462 nt) obtained from 29 clinical cases of PMWS in 22 Chilean intensive swine farms, covering over the 90% of the local pork-production, were analyzed. RESULTS: 14% and 52% of sequences belonged to the genotypes PCV2a and PCV2b, respectively. Surprisingly, 34% of sequences were PCV2a/PCV2d recombinant viruses. CONCLUSIONS: Our findings suggested that a novel cluster of Chilean sequences emerged resulting from intergenotypic recombination between PCV2a and PCV2d.

Novel Avulaviruses in Penguins, Antarctica.

We identified 3 novel and distinct avulaviruses from Gentoo penguins sampled in Antarctica. We isolated these viruses and sequenced their complete genomes; serologic assays demonstrated that the viruses do not have cross-reactivity between them. Our findings suggest that these 3 new viruses represent members of 3 novel avulavirus species.

Intususcepción gastroduodenal como presentación de un tumor del estroma gastrointestinal gástrico / Gastroduodenal intussusception as a presentation of gastric gastrointestinal stromal tumor

Objetivo Presentar un caso de GIST con presentación clínica poco usual. Caso clínico Presentamos una paciente de género femenino, de 70 años, con 5 días de dolor en hemiabdomen superior y vómitos; se le diagnóstica por TC de abdomen y pelvis con contraste una intususcepción gastroduodenal. Se ingresa a pabellón; confirmando diagnóstico, se realiza gastrectomía subtotal más Y de Roux. La biopsia diferida con inmunohistoquímica confirma un GIST gástrico con 2 mitosis cada 50 campos. Se decide manejo conservador y control anual con endoscopia digestiva alta. Buena evolución.

Aim To present a case of GIST with unusual clinical presentation. Case report We present a 70-year old female patient with 5 days of upper abdominal pain and vomiting, being diagnosed with a gastroduodenal intussusceptions by contrasted CT scan. She was admitted to the operating room, confirming the diagnosis and a subtotal gastrectomy with Roux-en-Y reconstruction was performed. A deferred biopsy with immunohistochemical confirmed GIST with 2 mitoses/50 high-powerfields. Conservative management was proposed and annual control with upper endoscopy decided. Satisfactory evolution.

The UDP-glucose: glycoprotein glucosyltransferase (UGGT), a key enzyme in ER quality control, plays a significant role in plant growth as well as biotic and abiotic stress in Arabidopsis thaliana.

BACKGROUND: UDP-glucose: glycoprotein glucosyltransferase (UGGT) is a key player in the quality control mechanism (ER-QC) that newly synthesized glycoproteins undergo in the ER. It has been shown that the UGGT Arabidopsis orthologue is involved in ER-QC; however, its role in plant physiology remains unclear. RESULTS: Here, we show that two mutant alleles in the At1g71220 locus have none or reduced UGGT activity. In wild type plants, the AtUGGT transcript levels increased upon activation of the unfolded protein response (UPR). Interestingly, mutants in AtUGGT exhibited an endogenous up-regulation of genes that are UPR targets. In addition, mutants in AtUGGT showed a 30% reduction in the incorporation of UDP-Glucose into the ER suggesting that this enzyme drives the uptake of this substrate for the CNX/CRT cycle. Plants deficient in UGGT exhibited a delayed growth rate of the primary root and rosette as well as an alteration in the number of leaves. These mutants are more sensitive to pathogen attack as well as heat, salt, and UPR-inducing stressors. Additionally, the plants showed impairment in the establishment of systemic acquired resistance (SAR). CONCLUSIONS: These results show that a lack of UGGT activity alters plant vegetative development and impairs the response to several abiotic and biotic stresses. Moreover, our results uncover an unexpected role of UGGT in the incorporation of UDP-Glucose into the ER lumen in Arabidopsis thaliana.

Estimación y comparación de la masa muscular por segmento, en deportistas juveniles chilenos / Muscle mass estimation and comparison by segment, in young Chilean athletes

El objetivo de este trabajo fue determinar y comparar la composición corporal de deportistas chilenos juveniles destacados, pertenecientes a las selecciones nacionales en el año 2011, de diferentes disciplinas deportivas mediante métodos antropométricos. Fueron evaluados 4 grupos de deportistas juveniles de alto rendimiento, con un número total de 92 individuos, pertenecientes a las disciplinas de lucha olímpica, halterofilia, básquetbol y fútbol. La Masa Muscular de los miembros superiores (MMES) es mayor en basquetbolistas y Halterofilistas con 7,49 (±1,25) y 7,50 (±2,54) kg respectivamente, al ser comparado con futbolistas, quienes obtuvieron un promedio de 5,27 (±0,37) kg. Por otra parte la lucha olímpica posee un promedio de masa muscular de 6,46 (±1,50) kg, la cual está por debajo de los basquetbolistas y Halterofilistas, debido a que la utilización de los miembros superiores es menor que en las disciplinas anteriormente mencionadas, pero a su vez, es mayor que la de los futbolistas. No se aprecian diferencias importantes en la masa muscular total, pero que son marcadas en la masa muscular por segmentos. Concluimos que la estimación de la masa muscular total, no es un elemento suficiente para determinar y predecir el rendimiento deportivo de los sujetos, a diferencia de la segmentación de la masa muscular que permite comparar de mejor forma, la manera en que se distribuye este componente en las distintas disciplinas deportivas, mejorando la especificidad del conocimiento.

The aim of this study was to determine and compare by anthropometric methods, the body composition of elite young Chilean athletes, who were part of the 2011 national team in different sports. Four groups of elite young athletes were evaluated, with a total number of 92 individuals belonging to the wrestling, weightlifting, basketball and football disciplines. The muscle mass of the upper extremities (MMES) is higher in basketball players and bodybuilders with 7.49 (±1.25) and 7.50 (±2.54) kg respectively, when compared with players who scored an average of 5.27 (±0.37) kg. Moreover, wrestling has an average muscle mass of 6.46 (±1.50) kg which is below that of basketball players and bodybuilders, because the use of upper limbs is less than in disciplines mentioned above, but in turn, is greater than that of football players. No significant differences in total muscle mass are reported, however, there are marked differences in muscle mass segment. We concluded that the estimate of total muscle mass is not sufficient basis to determine and predict athletic performance of the subjects. Muscle mass segment on the other hand, provides a better comparison range for the way in which this component is distributed among different sports disciplines, improving specific knowledge and information.

Multiple primary gastrointestinal stromal tumors presenting in jejunum and ileum.

Multiple primary gastrointestinal stromal tumors (GIST) are an infrequent finding. Benign and malignant tumors could coexist in the same patient. We discuss one case of a benign jejunal GIST and a malignant ileal GIST coexisting in the same patient and present their radiological characteristics.

A deficiency in the flavoprotein of Arabidopsis mitochondrial complex II results in elevated photosynthesis and better growth in nitrogen-limiting conditions.

Mitochondrial complex II (succinate dehydrogenase [SDH]) plays roles both in the tricarboxylic acid cycle and the respiratory electron transport chain. In Arabidopsis (Arabidopsis thaliana), its flavoprotein subunit is encoded by two nuclear genes, SDH1-1 and SDH1-2. Here, we characterize heterozygous SDH1-1/sdh1-1 mutant plants displaying a 30% reduction in SDH activity as well as partially silenced plants obtained by RNA interference. We found that these plants displayed significantly higher CO(2) assimilation rates and enhanced growth than wild-type plants. There was a strong correlation between CO(2) assimilation and stomatal conductance, and both mutant and silenced plants displayed increased stomatal aperture and density. By contrast, no significant differences were found for dark respiration, chloroplastic electron transport rate, CO(2) uptake at saturating concentrations of CO(2), or biochemical parameters such as the maximum rates of carboxylation by Rubisco and of photosynthetic electron transport. Thus, photosynthesis is enhanced in SDH-deficient plants by a mechanism involving a specific effect on stomatal function that results in improved CO(2) uptake. Metabolic and transcript profiling revealed that mild deficiency in SDH results in limited effects on metabolism and gene expression, and data suggest that decreases observed in the levels of some amino acids were due to a higher flux to proteins and other nitrogen-containing compounds to support increased growth. Strikingly, SDH1-1/sdh1-1 seedlings grew considerably better in nitrogen-limiting conditions. Thus, a subtle metabolic alteration may lead to changes in important functions such as stomatal function and nitrogen assimilation.