Proteasome inhibition rapidly exacerbates photoinhibition and impedes recovery during high light stress in Chlamydomonas reinhardtii.

BACKGROUND: Proteasomes remove regulatory proteins in eukaryotic cells, and control a variety of plant processes. Proteasomes are localized to the cytosol and nuclear, but their role in plant biology has recently been extended to chloroplasts, where it regulates TOC complex. This is turn controls the import of nuclear-encoded chloroplastic proteins, which remodels the chloroplast proteome and facilitates proper developmental transitions. Proteasomal regulation of the TOC complex also alleviates stressors that generate reactive oxygen species. These recent advances motivated us to determine if proteasome inhibition rapidly alters photosynthetic processes stemming from photoinhibition induced by high light. RESULTS: The short-term effects of proteasome inhibition on photosystem II during light stress was measured in Chlamydomonas reinhardtii, which allowed the dual monitoring of both chlorophyll fluorescence and cell viability. After 48 h at low light, proteasome inhibition did not affect viability or photochemistiry, but decreased cell concentration and increased cell volume. Two hours of high light stress impaired the efficiency of photosystem II in proteasome-inhibited cells, as determined by a decrease in Fv/Fm and the electron transport rate. Elevated photoinhibition in proteasome inhibited cells was not caused by a decrease in cell viability or chlorophyll content. Recovery from photoinhibition was attenuated in MG132-treated cells, and suppressed growth of a reestablished culture. Proteasome inhibition decreased de novo protein synthesis, which possibly constrained the ability to remodel the plastid proteome, and thus hampering the ability to adjust to high light stress. CONCLUSION: The proteasome is implicated in protecting photosystem II from photoinhibition. In addition to high light stress, other stressors- including metals, drought, and salt- are also known to generate reactive oxygen species localized to the chloroplast. Therefore, proteasome maintenance in plants may help protect photosynthesis during abiotic stress, which could increase crop yield during adverse conditions.

Sensitization to fragrances in Spain: A 5-year multicentre study (2011-2015).

BACKGROUND: Fragrance chemicals constitute the second most frequent cause of contact allergy in Spain. There are no data available concerning the individual fragrances that are most frequently involved. OBJECTIVES: To describe the diagnostic contribution provided by specific fragrance series to the results obtained with baseline series fragrance markers by correlating the results of both series. MATERIALS AND METHODS: We performed a 5-year retrospective study of fragrance marker-positive patients tested with specific fragrance series in 23 Spanish centres. We collected the demographic and clinical characteristics, and compared the results of patch tests obtained from different suppliers. RESULTS: Of 19 588 patients patch tested with the Spanish baseline series, 1590 (8.1%) reacted positively to a fragrance marker. Of these, 1013 (63.7%) were patch tested with a fragrance series, and 664 patients reacted positively to at least one individual fragrance other than hydroxyisohexyl 3-cyclohexene carboxaldehyde. Geraniol was the most frequent allergen. Positive reactions to substances not included in fragrance mix (FM) I or FM II were found in 230 patients. Of the 436 FM I-positive patients and the 419 FM II-positive patients, 184 (42%) and 64 (39.1%), respectively, had no positive reactions to fragrance series. In the case of FM I, negative results were more common when individual fragrances were patch tested at low concentrations. CONCLUSIONS: We recommend patch testing all patients positive for any fragrance marker with a specific fragrance series. The correlation between the results of baseline series and fragrance series could be improved by increasing the concentrations of individual fragrances.

[Feasibility of the construction of a magnetorheological joint for a lower limb orthosis in valve configuration]. / Viabilidad de la construcción de articulación magnetoreológica para ortesis de miembro inferior en configuración de válvula.

Ortheses are devices that assist in the function of the limbs, contributing with stability and support to the involved joints. KAFOs (knee-ankle-foot orthosis) are mainly indicated for people with muscular or neural diseases that affect the lower limbs. The actual designs of knee hinges for KAFOs compromise the stability and mobility of the limb. In this work, it was tested the feasibility of a design for a knee hinge for KAFO that should be able to modify its mechanical resistance depending on the gait phase. Orthotics biomechanical criteria and gait biomechanical requirements were considered. It was proposed an electromagnetic system in order to modify the hinge damping. In the future, the system will be interacting with a magnetorheological fluid (MR) which can change its rheological properties when a magnetic field is applied, thus, reaching different damping constants with the designed hinge. The diameter of the internal pipes required for the MR fluid to freely circulate within the orthosis was established. It was observed that the original design of the proposed orthotic hinge is feasible; however, some proposals are presented in order to achieve a better performance of the orthosis.

Risk factors associated to bovine brucellosis seroprevalence in the eastern region of Paraguay.

In Paraguay, whose main economic activity is cattle raising, bovine brucellosis is an endemic disease. Between May 2019 and October 2020, a national prevalence survey was implemented by the Paraguayan Veterinary Services. In the frame of that survey, a cross-sectional study was conducted in the eastern region of Paraguay to identify the risk factors that could be associated with brucellosis-positive farms and to estimate the bovine brucellosis seroprevalence and farmers' awareness about the disease. A questionnaire was administered to farmers to collect data on potential risk factors for bovine brucellosis as well as awareness on the disease. A logistic regression model was used to identify the risk factors associated with a farm brucellosis positive status. Blood samples were collected from 2551 cattle on 133 farms. The overall apparent seroprevalence was 27.8 % (95 % CI: 20.4-36.3 %) at the farm level, and 5.5 % (95 % CI: 4.7-6.5 %) at the animal level. Among 18 potential risk factors, four were associated with a farm brucellosis positive status. Farm size was associated with a higher risk of positive status in medium (20-80 cows) and large farms (>80 cows), compared with small farms (<20 cows). Barn disinfection had a protective effect on the risk of positive status. Conversely, presence of dogs and not incinerating/burying aborted material increased this risk. Even if 89 % of the farmers acknowledged being aware of the bovine brucellosis transmission to humans, only 46% of these farmers declared using protective gloves during calving or when handling abortions. The findings of this study emphasize the importance of implementing biosecurity measures and proper disposal of aborted material to control the disease. Therefore, to control the disease in Paraguay, vaccination campaigns should be accompanied by awareness campaigns addressing good farm management practices to minimize the risk of introduction and maintenance of brucellosis as well as the risk of human infection.

Inflammatory response and dynamics of lung T cell subsets in Th1, Th2 biased and Th2 deficient mice during the development of hypersensitivity pneumonitis.

It is considered that hypersensitivity pneumonitis (HP) occurs with a Th1 cell dominance; however, the role of Th1/Th2 balance is still unclear. C57BL/6 (Th1-biased), BALB/c wt (Th2-biased) and BALB/c Stat6-/- (Th2 deficient) mice were treated with Saccharopolyspora rectivirgula (SR) or saline during 3 weeks, and sacrificed 1 and 4 days (early and late response) after the last administration. Lung isolated T cell subpopulations were analyzed and lung damage extent was quantified. C57BL/6 wt mice exhibited a significant increase in the extent of lung damage when sacrificed at 4 days compared with those sacrificed 1 day after the last SR administration. In contrast, BALB/c wt mice showed a progressive decrease in the extent of lung damage. A significant increase of NKT CD4+ subset was found in C57BL/6 mice while NKT DN cells were increased in BALBc wt mice. Also, NK and gammadelta T cells were increased in BALB/c mice at 1 and 4 days. Stat6-/- mice behave similar to the C57BL/6 mice, showing a progressive increase in the extent of lung damage. A significant increase in the levels of Th1 and Th2 cytokines was observed in bronchoalveolar lavage from the SR-treated mice. These results confirm a predominant role of the Th1 response in HP and suggest that the control of inflammation by Th2 biased mice may be related with the increase of NKT DN cells and regulatory NK and gammadelta T cells.

Silicone injection causing acute pneumonitis: a case series.

Local and systemic complications following injected silicone have been described, especially after cosmetic procedures by unlicensed practitioners. We report a retrospective case series of acute pneumonitis following silicone injection to the buttock. Medical records, pulmonary function tests, blood arterial gases, chest radiographs, and high-resolution computed tomography scans were reviewed. Five patients with acute pneumonitis after injected silicone were identified. All cases were men with a mean age was 25 years. Three patients had the procedure performed by the same practitioner. The amount of injected silicone ranged from 30 to 500 ml. The onset of clinical symptoms began as early as 24 h after injection to as late as 15 days. All cases had diffuse, peripheral, occasionally wedge-shaped opacities on high-resolution computed tomography. At presentation the mean oxygen saturation was 84%. All were treated with steroids and had clinical resolution of their illness within 1 month of presentation. Injection of silicone can lead to serious pulmonary complications but treatment with steroids seems to be beneficial.

Functional diversity of T-cell subpopulations in subacute and chronic hypersensitivity pneumonitis.

RATIONALE: Hypersensitivity pneumonitis (HP) exhibits a diverse outcome. Patients with acute/subacute HP usually improve, whereas patients with chronic disease often progress to fibrosis. However, the mechanisms underlying this difference are unknown. OBJECTIVES: To examine the T-cell profile from patients with subacute HP and chronic HP. METHODS: T cells were obtained by bronchoalveolar lavage from 25 patients with subacute HP, 30 patients with chronic HP, and 8 control subjects. T-cell phenotype and functional profile were evaluated by flow cytometry, cytometric bead array, and immunohistochemistry. MEASUREMENTS AND MAIN RESULTS: Patients with chronic HP showed higher CD4+:CD8+ ratio (median, 3.05; range, 0.3-15; subacute HP: median, 1.3; range, 0.1-10; control: median, 1.3; range, 0.7-2.0; P < 0.01), and a decrease of gammadeltaT cells (median, 2.0; range, 0.5-3.4; subacute HP: median, 10; range, 4.8-17; control: median, 15; range, 5-19; P < 0.01). Patients with chronic HP exhibited an increase in the terminally differentiated memory CD4+ and CD8+ T-cell subsets compared with patients with subacute HP (P < 0.05). However, memory cells from chronic HP showed lower IFN-gamma production and decreased cytotoxic activity by CD8+ T lymphocytes. Chronic HP displayed a Th2-like phenotype with increased CXCR4 expression (median, 6%; range, 1.7-36, vs. control subjects: median, 0.7%; range, 0.2-1.4; and subacute HP: median, 2.2%; range, 0.1-5.3; P < 0.01), and decreased CXCR3 expression (median, 4.3%; range, 1.4-25%, vs. subacute HP: median, 37%; range, 4.9-78%; P < 0.01). Likewise, supernatants from antigen-specific-stimulated cells from chronic HP produced higher levels of IL-4 (80 +/- 63 pg/ml vs. 25 +/- 7 pg/ml; P < 0.01), and lower levels of IFN-gamma (3,818 +/- 1671 pg/ml vs. 100 +/- 61 pg/ml; P < 0.01) compared with subacute HP. CONCLUSIONS: Our findings indicate that patients with chronic HP lose effector T-cell function and exhibit skewing toward Th2 activity, which may be implicated in the fibrotic response that characterizes this clinical form.

Local and circulating microchimerism is associated with hypersensitivity pneumonitis.

RATIONALE: Hypersensitivity pneumonitis (HP) is a lymphocytic alveolitis provoked by exposure to a variety of antigens. However, the disease occurs in only a subset of exposed individuals, suggesting that additional factors may be involved. Microchimerism has been implicated in the pathogenesis of autoimmune diseases, especially in those showing increased incidence after childbearing age. OBJECTIVES: To evaluate the presence of circulating and local microchimeric cells in female patients with HP. METHODS: Male microchimerism was examined in 103 patients with HP, 30 with idiopathic pulmonary fibrosis (IPF), and 43 healthy women. All of them had given birth to at least one son, with no twin siblings, blood transfusions, or transplants. Microchimerism was examined by dot blot hybridization (peripheral blood), and by fluorescence in situ hybridization in bronchoalveolar lavage cells and lungs. MEASUREMENTS AND MAIN RESULTS: Blood microchimerism was found in 33% of the patients with HP in comparison with 10% in those with IPF (p = 0.019) and 16% in healthy women (p = 0.045). Patients with HP with microchimerism showed a significant reduction of diffusing capacity of carbon monoxide (Dl(CO); 53.5 +/- 11.9% vs. 65.2 +/- 19.7%; p = 0.02) compared with patients with HP without microchimerism. In bronchoalveolar lavage cells, microchimerism was detected in 9 of 14 patients with HP compared with 2 of 10 patients with IPF (p = 0.047). Cell sorting revealed that microchimeric cells were either macrophages or CD4+ or CD8+ T cells. Male microchimeric cells were also found in the five HP lungs examined by fluorescence in situ hybridization. CONCLUSIONS: Our findings (1) demonstrate that patients with HP exhibit increased frequency of fetal microchimerism, (2) confirm the multilineage capacity of microchimeric cells, and (3) suggest that microchimeric cells may increase the severity of the disease.

1H NMR-based metabolomic fingerprinting to determine metabolite levels in serrano peppers (Capsicum annum L.) grown in two different regions.

Chili pepper (Capsicum annuum) is the most important and emblematic condiment in Mexican food. Serrano pepper is a variety of C. annuum that is traditionally cultivated in Mexico and commercialized in local markets. The aim of this study was to describe the 1H NMR metabolomic profiling of the aqueous phase of serrano peppers harvested from two distinct regions, in the states of Veracruz and Oaxaca, Mexico. According to the current results, aspartate citrate, lactate, leucine and sucrose were found at higher amount in the serrano peppers from Veracruz. On the other hand, acetate, formate, fumarate, malonate, phosphocholine, pyruvate and succinate showed the highest abundance in this product from Oaxaca. These are the main metabolites that distinguish one group from the other. The spectrometric method reported presently is characterized by great simplicity, robustness and reproducibility. Thus, this technique can be used for establishing reliable metabolomic fingerprints of serrano peppers grown under different environmental conditions.

Hypersensitivity pneumonitis : a broader perspective.

Hypersensitivity pneumonitis (HP) represents a group of lung disorders caused by the inhalation of a wide variety of organic particles by susceptible individuals. HP occurs mainly in nonsmokers, but smoking may promote an insidious and chronic disease. The prevalence of HP is difficult to estimate accurately since several antigens can produce the disease, but the range spans infancy to old age. Regardless of the causative antigen or its environmental setting, the clinical manifestations are essentially the same. Three different clinical presentations have been recognized: acute, subacute, and chronic. In the acute form, patients show flu-like symptomatology, followed by dyspnea and dry cough. Symptoms subside a few hours or days later. The subacute and chronic forms result from recurrent low-level antigen exposure and are characterized by progressive dyspnea and dry cough. Other constitutional symptoms such as fatigue, anorexia, and weight loss can be apparent. Fever may occur in the subacute form. Importantly, chronic HP may evolve insidiously or may result from repeated acute/subacute episodes. Recurrent acute, subacute, and chronic HP may progress to irreversible lung fibrosis or provoke emphysematous changes.HP can be difficult to identify, and precise diagnosis requires a history of exposure and a constellation of clinical, imaging, laboratory, bronchoalveolar lavage and pathologic findings. General laboratory tests show an increase of acute phase reactants. Specific precipitating antibodies, when present, are evidence of antigen exposure, and are a hallmark for diagnosis. Chest radiograph usually reveals widespread ground-glass attenuation, and nodular or reticulonodular shadowing. High-resolution CT features include diffuse or patchy ground-glass opacities with small poorly defined nodules and air trapping. Pulmonary function tests are characterized by a predominantly restrictive ventilatory defect with loss of lung volume and hypoxemia at rest that worsens with exercise. Bronchoalveolar lavage reveals a significant increase in lymphocytes, mostly over 40%. In the acute form there is also an increase in neutrophils. Antigen-induced lymphocyte proliferation, and environmental or laboratory-controlled inhalation challenge, may be used for diagnostic purposes and can help to establish a diagnosis of insidious forms of HP. In subacute or chronic cases, lung biopsy may be necessary. Typical findings include bronchiolitis, lymphocytic alveolitis, and loosely formed granulomas, although occasionally other morphologic patterns such as nonspecific interstitial pneumonia may exist. Treatment focuses on avoiding further exposure to the offending antigen(s). Corticosteroids are recommended in subacute and chronic forms. The usual regimen consists of initial high doses of systemic corticosteroid (e.g. prednisone 0.5-1.0 mg/kg/day), followed by gradual tapering.

Up-regulation of L-selectin and E-selectin in hypersensitivity pneumonitis.

BACKGROUND: Selectins are adhesion molecules that contribute to leukocyte recruitment into the tissue after an injury. Hypersensitivity pneumonitis (HP) is a lymphocytic alveolitis, and we hypothesized that the overexpression of selectins could play a role in this process. PATIENTS AND MEASUREMENTS: We studied 16 patients with HP and 7 healthy control subjects (HCs). Sera and BAL selectins and tumor necrosis factor-alpha were determined by enzyme-linked immunosorbent assay, and cellular lung localization was determined by immunohistochemistry. Additionally, BAL L-selectin, and L-selectin-bearing T-lymphocytes analyzed by flow cytometry were evaluated in HP patients and in exposed but asymptomatic subjects (EAS). SETTING: Tertiary referral center and immunohistochemistry laboratory. RESULTS: Raised levels of E-selectin (mean [+/- SD], 178.9 +/- 30.5 vs 59.4 +/- 4.7 ng/mL, respectively; p < 0.001) and P-selectin (mean, 232.6 +/- 29.9 vs 67.6 +/- 14.2 ng/mL, respectively; p < 0.001) were detected in HP patient sera compared to control subjects, while L-selectin levels showed no differences between groups. Conversely, HP patients displayed a significant increase in levels of L-selectin found in BAL fluid compared with both HCs and EAS (11.0 +/- 1.7 vs 6.9 +/- 0.43 and 3.1 +/- 0.5 ng/mL, respectively; p < 0.05). The levels of E-selectin found in BAL fluid were similar in patients from both groups, and P-selectin was not detected. Percentage of CD3+CD62 L+ lymphocytes was lower in HP patients compared with EAS (2.33 +/- 0.8 vs 4.31 +/- 2.4, respectively; p = 0.05). By immunohistochemistry, L-selectin was detected in interstitial macrophages and polymorphonuclear cells, and E-selectin was detected in endothelial cells. CONCLUSION: These findings demonstrate that L-selectin and E-selectin are up-regulated during the development of HP, suggesting that they may contribute to the increased traffic of lung inflammatory cells.

[Familial pulmonary fibrosis in 2 Mexican sisters with Hermansky-Pudlak syndrome]. / Fibrosis pulmonar familiar en 2 hermanas mexicanas con síndrome de Hermansky-Pudlak.

Hermansky-Pudlak syndrome is an autosomal recessive disorder commonly found in individuals of Puerto Rican ancestry. We present 2 cases of familial pulmonary fibrosis in 2 Mexican sisters with Hermansky-Pudlak syndrome. Pulmonary fibrosis was biopsy-proven in 1 of the patients. This report shows that Hermansky-Pudlak syndrome may occur in individuals of Mexican ancestry.

Major histocompatibility complex and alveolar epithelial apoptosis in idiopathic pulmonary fibrosis.

Idiopathic pulmonary fibrosis (IPF) is a chronic disease characterized by fibroblast expansion, and tissue remodeling. It is considered a multifactorial disease but the possible involved genes are largely unknown. Interestingly, studies regarding the possible role of major histocompatibility complex (MHC) are scanty and show contradictory results. In this study, we evaluated the polymorphisms of the MHC, locus HLA-B, -DRB1, and -DQB1 in a cohort of 75 IPF patients and 95 controls by using PCR and hybridization with sequence-specific oligonucleotide probes. In addition, we examined the effect of bronchoalveolar lavage (BAL) from IPF patients with different MHC haplotypes on alveolar epithelial growth rate by WST-1 cell viability assay and on epithelial apoptosis by flow cytometry and by cleaved caspase-3 in cell homogenates. Three haplotypes were significantly increased in IPF: (1) HLA-B*15-DRB1*0101-DQB1*0501 (OR=10.72, CI=1.43-459.6; pC=0.011); (2) HLA-B*52-DRB1*1402-DQB1*0301 (OR=4.42, CI=1.21-24.1; pC=0.024); and (3) HLA-B*35-DRB1*0407-DQB1*0302 (OR=4.73, CI=1.53-19.5; pC=0.005). BAL from patients with the later haplotype significantly reduced epithelial growth rate ( approximately 30%) and caused epithelial cell apoptosis assayed by cleaved caspase-3 (351.7+/-16.5 pg/10(6) cells versus 264+/-24 from controls, and 274+/-36.8 and 256.5+/-10.7 from the other haplotypes; P<0.05), and DNA breaks labeling by flow cytometry (23.7+/-6.9% versus 3.1+/-0.7% from controls, and 6.5+/-0.6% and 7.6+/-1.2% from the other two haplotypes; P<0.01). These findings suggest that some MHC polymorphisms confer susceptibility to IPF, which might be related with the induction of epithelial cell apoptosis, a critical process in the development of the disease.

Traducción de ARN obtenido de Entamoeba histolytica y su caracterización con un anticuerpo monoclonal específico / Translation of RNA obtained of Entamoeba histolytica and its characterization with a specific monoclonal antibody

En este reporte describimos la obtención de productos de traducción de un ARN total de E. histolytica, en un sistema libre de células, y su reactividad con anticuerpos contra el parásito. Mientras los anticuerpos de pacientes con amibiasis invasora muestran una reactividad compleja con tales productos, el anticuerpo monoclonal específico para E. histolytica presenta una reactividad más definida, en la cual destacan tres componentes principales. La combinación de estas dos metodologías ofrece la posibilidad de obtener uno o varios mRNAs que puedan ser de utilidad, tanto en el diagnóstico como en la inmunoprofilaxis de esta enfermedad

Caracterización inmunológica de un anticuerpo monoclonal específico para E. Histolytica / Inmunological characterization of an specific monoclonal antibody for E. histolytica

En este reporte informamos sobre la caracterización de un anticuerpo monoclonal contra E. histolytica. El anticuerpo mostró ser específico para E. histolytica ya que no reaccionó por inmunofluorescencia ni por la prueba de ELISA como otras Entamoeba, específicamente con E. moshkovskii, E. invadens y de la cepa Laredo de tipo E. histolytica. Los estudios de inmunoelectrotransferencia de un antígeno de membrana de E. histolytica indican que el anticuerpo monoclonal reconoce tres polipéptidos de diferente peso molecular, que pueden ser el resultado de un precursor comín o debido a un artefacto causado por la degradación enzimática de uno de los componentes de la amiba

On the correct determination of reference values for serum antibodies against pigeon serum antigen using a group of healthy blood donors

An ensymatic immunoassay was developed in order to evaluate the statistical distribution of IgG serum antibodies against pooled pigeon ser antigen in 102 healthy blood donors (HBD). A non-normal distribution was obtained as demonstrated by abnormal values of skewness (2.02) and kurtosis (6.50). A cut-off point (0.120) was determined from the mean plus 2 standard derivations of the optical density values obtained in the HBD group. This value was able to segregate 94 percent of subjects. However, when calculation of the mean less 2 SD was performed to delimit 95 percent of the samples, an aberrant negative value was obtained. In contrast, when the nonparametric method of percentile calculation was applied, an optical density value of 0.130 discriminated 97.5 percent of samples. In addition, the interval between p97.5 and p2.5 delimited 95 percent of samples. We conclude that when reference values and cut-off point are determined from an enzymatic immunoassay, careful analysis of the statistical distribution of reference values is necesary in order to avoid the inappropiated in this study for antibodies against pigeon serum antigens

Anticuerpos antifosfolípidos: aspectos inmunoquímicos y patogénicos / Antiphospholipid antibodies: immunochemistry and pathogenetic features

Los anticuepos antifoslípidos (AFL), incluyen varios tipos como los que se describieron inicialmente en las enfermedades infecciosas. Además, se conocen ahora otros AFL como son los reactivos contra cardiolipina o los denominados anticoagulante de lupus. Estos AFL pueden ser isotipo IgG,M o A, la mayor relevancia actualmente se confiere al isotipo IgG. La especificidad parece estar dirigida a fosfolípidos con carga negativa y juega un papel importante a Apolipoproteína H como cofactor o integrante del complejo antigénico reconocido por una proporción de estos AFL. El impacto patogénico de estos AFL no se ha definido con certeza, pero la evidencia muestra intervención potencial en las fases de la coagulación dependientes de fosfolípidos