RESUMO
Regulatory T cells (Tregs), a subset of CD4+ T cells related with immune regulation, have been associated with active and latent tuberculosis infection (LTBI). Treg frequencies were evaluated by multicolor flow cytometry (FC) in peripheral blood mononuclear cells (PBMCs) stimulated with mycobacterial antigens ESAT-6, CFP-10, and TB7.7 to assess their capacity to distinguish subjects with different reactivity to the QuantiFERON-TB® Gold In-Tube (QFT-IT) test and the tuberculin skin test (TST). Increased frequencies of CD4+CD25highCD39+ cells were found for the [TST+, QTF+] compared with the [TST+, QTF-] group. Also, higher frequencies were observed for the [TST+, QTF+] compared with the [TST+, QTF-] and [TST-, QTF-] groups in CD4+CD25highFoxp3+ and CD4+CD25highCD39+Foxp3+ populations. Receiver operating characteristics (ROC curve) analysis confirmed these discriminating results. QFT-IT and TST quantitative values correlated with several Treg population frequencies.
Assuntos
Antígenos de Bactérias/imunologia , Testes de Liberação de Interferon-gama , Tuberculose Latente/imunologia , Mycobacterium tuberculosis/imunologia , Linfócitos T Reguladores/imunologia , Teste Tuberculínico , Tuberculose Pulmonar/transmissão , Adulto , Antígenos CD/metabolismo , Apirase/metabolismo , Linfócitos T CD4-Positivos/imunologia , Linfócitos T CD4-Positivos/metabolismo , Estudos de Coortes , Feminino , Fatores de Transcrição Forkhead/metabolismo , Humanos , Técnicas In Vitro , Subunidade alfa de Receptor de Interleucina-2/metabolismo , Subunidade alfa de Receptor de Interleucina-7/metabolismo , Leucócitos Mononucleares , Masculino , Pessoa de Meia-Idade , Subpopulações de Linfócitos T/imunologia , Subpopulações de Linfócitos T/metabolismo , Linfócitos T Reguladores/metabolismo , Adulto JovemRESUMO
We have hypothesized that individuals infected with Mycobacteriumtuberculosis that exhibit different patterns of immune reactivity in serial interferon (IFN)-γ release assays (IGRA's) correspond to different status within the immune spectrum of latent tuberculosis (TB). Accordingly, we analyzed the possible association between the consistent results (negative or positive) in an IGRA test and relevant immune parameters, mainly the levels of Th1 and Th17 lymphocytes and T regulatory (Treg) cells in the peripheral blood of TB case contacts. We found that individuals with a persistently positive IGRA showed increased levels of Th1 and Th17 lymphocytes upon in vitro stimulation with MTB antigens. In addition, a significant increase in the proportion of CD4+CTLA-4+ and CD4+Foxp3+ cells was detected in assays with blood samples from these individuals. Our data support that different immune phenotypes can be identified into the spectrum of latent TB, by combining different parameters of immune reactivity against MTB.
Assuntos
Testes de Liberação de Interferon-gama , Tuberculose Latente/diagnóstico , Mycobacterium tuberculosis/imunologia , Linfócitos T Reguladores/imunologia , Células Th1/imunologia , Células Th17/imunologia , Adulto , Antígenos CD4/sangue , Antígeno CTLA-4/sangue , Feminino , Fatores de Transcrição Forkhead/sangue , Humanos , Interferon gama/imunologia , Tuberculose Latente/imunologia , Tuberculose Latente/microbiologia , MasculinoRESUMO
Differential A-fibre block of human peripheral nerves changes the sensation evoked by innocuous cooling (approximately 24 degrees C) of the skin from 'cold' to 'hot' or 'burning', and this has been attributed to activity in unidentified unmyelinated fibres that is normally masked or inhibited by activity in Adelta cold fibres. Application of the TRPM8 agonist menthol to the skin evokes 'burning/stinging' as well as 'cold', and the unpleasant sensations are also enhanced by A-fibre block. In this study we used microneurography to search for C fibres in human skin activated by cooling and menthol, which could be responsible for these phenomena. Afferent C fibres were classified by activity-dependent slowing as Type 1A (polymodal nociceptor), Type 1B (mechanically insensitive nociceptor) or Type 2 (cold sensitive), and their responses to heating and cooling ramps were measured before and after topical application of menthol preparations (2-50%). The only C fibres activated by menthol were the Type 2 fibres, which discharged vigorously with innocuous cooling and were strongly activated and sensitized to cooling by menthol. Unlike an Adelta cold fibre, they continued to discharge at skin temperatures down to 0 degrees C, and most (13/15) were also activated by heating. We propose that the Type 2 C fibres, although resembling Adelta cold fibres in their responses to innocuous cooling and menthol, have a more complex sensory function, colouring with a 'hot-burning' quality the perceptions of low and high temperatures. Their bimodal thermoreceptive properties may help account for several puzzling psychophysical phenomena, such as 'innocuous cold nociception', 'paradoxical heat' and the thermal grill illusion, and also for some neuropathic pains.
Assuntos
Mentol/farmacologia , Fibras Nervosas Amielínicas/fisiologia , Pele/inervação , Potenciais de Ação/efeitos dos fármacos , Potenciais de Ação/fisiologia , Adolescente , Adulto , Temperatura Baixa , Eletrofisiologia , Feminino , Temperatura Alta , Humanos , Masculino , Pessoa de Meia-Idade , Fibras Nervosas Amielínicas/efeitos dos fármacos , Nociceptores/efeitos dos fármacos , Nociceptores/fisiologia , Limiar da Dor/efeitos dos fármacos , Limiar da Dor/fisiologia , Sensação Térmica , Adulto JovemRESUMO
Galectin-3 has been implicated in tumor progression. We demonstrated immunohistochemically that galectin-3 was negative in normal breast tissue, but it was highly increased in breast cancer and in metastatic tissues to brain. Similarly, histochemistry with mucin-specific lectins showed increased recognition in breast tumor and metastasis with Machaerocereus eruca agglutinin (Fualpha 1,2 (GalNAcalpha 1,3) Galss1,4 in complex mucin) but not for Amaranthus leucocarpus (Galss1,3-GalNAc-alpha 1,0-Ser/Thr) and Arachis hypogaea lectins (Galss1,3GalNAc/Galss1,4GlcNAc). Mucin-type glycans and galectin-3 colocalized in breast cancer and metastasis, but not in normal tissue, suggesting upregulated biosynthesis of complex O-glycosidically linked glycans and galectin-3 favor breast cancer progression and brain metastasis.
Assuntos
Neoplasias Encefálicas/química , Neoplasias da Mama/química , Galectina 3/análise , Mucinas/análise , Arachis , Neoplasias Encefálicas/metabolismo , Neoplasias Encefálicas/secundário , Neoplasias da Mama/metabolismo , Neoplasias da Mama/patologia , Feminino , Glicoproteínas , Glicosilação , Histocitoquímica/métodos , Humanos , Imuno-Histoquímica , Mucinas/metabolismo , Neuraminidase/metabolismo , Lectinas de Plantas , Manejo de Espécimes/métodos , Tripsina/metabolismo , Regulação para CimaRESUMO
Postharvest rotting caused by Penicillium italicum Wermer is responsible for significant economic losses of orange (Citrus sinensis (L.) Osbeck) and lemon (C. limon Burm. f.) worldwide, but until now was not described on lemons (C. aurantifolia (Chistm.) Swingle) in Mexico. During May 2002, we analyzed 400 fruits of lemon collected in the state of Colima, which is the most important lemon producer in Mexico. Rotting and softened areas covered with a white mycelium and blue conidia were observed on approximately 30% of the fruits. Affected tissue was plated onto potato dextrose agar (PDA) for fungal isolation and identification. Following the morphological criteria (1) and the internal transcribed spacer 1 (ITS1), 5.8S, and ITS2 region of the ribosomal DNA (2) (GenBank Accession No. DQ991463), the fungus was identified as P. italicum and deposited in the Colección Microbiana y de Cultivos Celulares CINVESTAV-IPN, México. For the pathogenicity test, the fungus was grown on PDA for 1 week. Four drops (15 µl each) of a sterile water suspension of 106 conidia per ml were placed in four wounds of 3 × 3 × 3 mm produced with a scalpel on the fruit surface. Five plastic boxes with six fruits each were placed in an environmental chamber at 12°C and 90% relative humidity. After 10 days, all fruit rotted in a similar way as naturally infected fruit on trees. Control fruits inoculated with sterile distilled water were symptomless. The test was repeated and the results were similar, confirming Koch's postulates. To our knowledge, this is the first report describing the isolation and pathogenicity of P. italicum on lemon (C. aurantifolia) in Colima, Mexico, which may have important implications in fruit quality and storage. References: (1) Z. Kozakieweicz. IMI Descriptions of Fungi and Bacteria. 155, Sheet 1548, 2002. (2) M. J. Pianzzola et al. Plant. Dis. 88:23, 2004.
RESUMO
The sensory territories of different cutaneous fascicles of the superficial radial nerve were delineated by microneurography at the level of the distal forearm in humans. Three fascicular patterns were found at this level: one supplying the dorsum of the radial aspect of the dorsum of the hand over the first dorsal interosseous space; another supplying the lateral aspect of the first metacarpal extending to the lateral aspect of the thumb; and a third innervating the second interosseous space and the proximal phalanx of the index and middle fingers. The compound fascicular territory is comparable to the classical territory described for the superficial radial nerve. Intraneural microstimulation of individual fascicles did not evoke paraesthesiae or pain beyond their fascicular territory, regardless of the stimulus intensity. We conclude that the superficial radial nerve at the forearm in man is composed of only three fascicles, as shown by the present study and from previous anatomical work. Referred pain seems related to nerve activity in afferent fibres from fascicles supplying deep tissues and muscles, not from cutaneous afferents.
Assuntos
Mãos/inervação , Nervo Radial/fisiologia , Pele/inervação , Estimulação Elétrica , Feminino , Dedos/inervação , Humanos , Masculino , Microeletrodos , Fibras Nervosas/fisiologia , Fibras Nervosas/ultraestrutura , Limiar da Dor , Nervo Radial/anatomia & histologia , Sensação/fisiologiaRESUMO
A benthic toxic dinoflagellate identified as Prorocentrum lima (Syn. Exuviaella lima), and designated as strain PRL-1, was isolated from the coast of El Pardito (Coyote) Island in Baja California Sur, Mexico, after a fisherman poisoning incident involving consumption of liver from Lutjanus colorado, and Mycteroperca prionura fish. Purification and culturing was done in ES-Si medium, under 12:12 light/dark cycle (4 x 20 W cool-white fluorescent lamps), at 22 degrees C and constant stirring during 28 days. Whole cells were toxic to Artemia franciscana and its methanolic extract to mouse and to the marine yeast Debaryomyces hansenii. Chromatographic analysis (TLC and HPLC-MS) of such extract indicated an unusual proportion (1:2) okadaic acid (OA) and dinophysistoxin-1 (DTX-1). Estimated total toxin content by mouse bioassay (based on OA toxicity) was 19 pg/cell, a value significantly higher than that found by HPLC-MS (about 5.2 pg/cell, taking into account OA and DTX-1 only), suggesting that additional toxic components of unidentified nature are detected with the bioassay. This is the first report of a successful isolation and culturing of a toxic dinoflagellate from the Gulf of California, Mexico.
Assuntos
Diarreia/induzido quimicamente , Diarreia/epidemiologia , Dinoflagellida/química , Doenças Transmitidas por Alimentos/epidemiologia , Frutos do Mar/efeitos adversos , Frutos do Mar/análise , Animais , Cromatografia em Camada Fina , Ciguatera , Ciguatoxinas/análise , México , Camundongos , Ácido Okadáico/análise , Piranos/análise , Medição de RiscoRESUMO
1. Microneurography was used to search for primary afferents responsive to innocuous low temperature in human nerves supplying the hairy skin of the hand or foot. Eighteen units were identified as cold-specific units: they displayed a steady-state discharge at skin temperatures in the range 28-30 degrees C, they were sensitive to small changes in temperature, and they responded vigorously when a cool metal probe touched their receptive fields (RFs). They were insensitive to mechanical stimuli and sympathetic activation. Their RFs comprised one, or at most two, spots less than 5 mm in diameter. 2. Nine units were characterised in detail by a series of 10 s cooling and warming pulses from a holding temperature of 35 degrees C. The threshold temperature for activation by cooling was 29.4 +/- 2.0 degrees C (mean +/- S.D.). Adaptation of the responses to supra-threshold cooling pulses was partial: mean peak and plateau firing rates were maximal on steps to 15 degrees C (35.9 and 19.9 impulses x s(-1), respectively). Three of these units also displayed a paradoxical response to warming, with a mean threshold of 42.3 degrees C. 3. Sixteen of the eighteen cold-specific units were also studied by electrical stimulation of their RFs. They conducted in the velocity range 0.8-3.0 m x s(-1). When stimulated at 2 Hz, their latency increased according to a characteristic time course, reaching a plateau within 3 min (mean slowing (+/- S.D.) 5.2 +/- 1.1 %) and recovering quickly (50 % recovery in 17.8 +/- 4.5 s). 4. To reconcile these findings with previous studies of reaction times and the effects of nerve compression on sensation, it is concluded that either human cold-specific afferent fibres are incompletely myelinated 'BC' fibres, or else there are C as well as A(delta) cold fibres, with the C fibre group contributing little to sensation.
Assuntos
Temperatura Baixa , Neurônios Aferentes/fisiologia , Temperatura Cutânea/fisiologia , Estimulação Elétrica , Humanos , Fibras Nervosas/fisiologia , Fibras Nervosas Mielinizadas/fisiologia , Estimulação Física , Pele/inervação , Sistema Nervoso Simpático/fisiologiaRESUMO
We found that the marine yeast Debaryomyces hansenii strain C-11 (CIBNOR yeast collection, La Paz, Mexico) is highly tolerant to chlorine dioxide (ClO2), a powerful biocide agent. A direct application of this observation is the fermentation of the yeast in a nonsterile medium with an initial concentration of 0.3 mg/L of ClO2. The disinfectant helps to avoid the growth of unwanted microorganisms while allowing the development of the yeast. Because the concentration of ClO2 decreases during the fermentation, we ascribe to D. hansenii cells a "biocontrol" action that contributes to the collection of a contaminant-free yeast cell biomass.
Assuntos
Bactérias/efeitos dos fármacos , Compostos Clorados/farmacologia , Desinfecção/métodos , Óxidos/farmacologia , Saccharomycetales/crescimento & desenvolvimento , Água do Mar/microbiologia , Bactérias/crescimento & desenvolvimento , Meios de Cultura , Farmacorresistência Fúngica , Técnicas Microbiológicas , Peptonas , Saccharomycetales/efeitos dos fármacosRESUMO
BACKGROUND: Rat hind-foot carrageenan induced edema (CIE) is a widely used model to evaluate anti-inflammatory drugs. It shows two well-defined phases, however a third not fully characterized phase has been observed. Superoxide dismutase (SOD) is a free radical-scavenger with anti-inflammatory activity. In our country there is not a specifically designed instrument to evaluate edema in CIE. METHODS: Edema was induced by intraplantar injection of carraageenan. Fours groups were evaluated: placebo, two different doses of SOD, and Naproxen. Edema was evaluated by a specially designed mercury plethismograph. Intensity of the inflammatory reaction was determined during the classical early and late phases and during the third very late phase. RESULTS: All treatments, but higher dose of SOD, showed good anti-inflammatory activity throughout early, late, and very late phases. Naproxen was more effective than SOD during first and second phase, however this difference disappeared during the third phase. In terms of equimolar basis the enzyme appeared 1,800 time more potent than Naproxen. Mercury plethysmometer performance was fine. CONCLUSIONS: The anti-inflammatory activity of SOD and Naproxen is extended until the very late phase in the CIE model. In this bioassay, this long lasting activity of the enzyme should be ascribed to a mechanism supplementary to its free radical-scavenger property. SOD may be indeed an alternative treatment in inflammatory diseases.