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C M González

Publications and source records attributed to C M González.

17 recordsLinked to original sources
PubMed2005

Coupling-mediated ghost resonance in mutually injected lasers.

We experimentally and numerically study the phenomenon of ghost resonance in coupled nonlinear systems. Two mutually injected semiconductor lasers are externally perturbed in their pump currents by two respective periodic signals of different frequencies f(1) and f(2). For small amplitudes of the external modulations, the two laser intensities display synchronized optical pulses, in the form of dropout events occurring at irregular times. By adjusting the amplitude and frequencies of the driving signals, the system exhibits a ghost resonance in the dropout appearance at a frequency f(r) not present in the distributed inputs.

Electronics↗
PubMed2003

Applications of redundancy analysis for the detection of chemical response patterns to air pollution in lichen.

The lichens Ramalina celastri (Spreng.) Krog & Swinsc., Punctelia microsticta (Müll. Arg.) Krog and Canomaculina pilosa (Stizenb.) Elix & Hale were transplanted simultaneously to 17 urban-industrial sites in a northwestern area of Córdoba city, Argentina. The transplantation sites were set according to different environmental conditions: traffic, industries, tree cover, building height, topographic level, position in the block and distances from the river and from the power plant. Three months later, chlorophyll a, chlorophyll b, phaeophytin a, soluble proteins, hydroperoxy conjugated dienes, malondialdehyde concentration and sulfur accumulation were determined, and a pollution index was calculated for each sampling site. Redundancy analysis was applied to detect the variation pattern of the lichen variables that can be 'best' explained by the environmental variables considered. The present study provides information about both the specific pattern response of each species to atmospheric pollution, and environmental conditions that determine it. As regards pollutants emission sources R. celastri showed a chemical response associated mainly with pollutant released by the power plant and traffic. P. microsticta and C. pilosa responded mainly to industrial sources. Regarding environmental conditions that affect the spreading of air pollutants and their incidence on the bioindicator, the topographic level and tree cover surrounding the sampling site were found to be important for R. celastri, tree cover surrounding the sampling site and the building height affected P. microsticta, while building height did so for C. pilosa.

Air Pollutants↗
PubMed2003

Simultaneous identification of various antinuclear antibodies using an automated multiparameter line immunoassay system.

The objective was to determine the sensitivity and specificity of an automated multiparameter line immunoassay system compared with other techniques for the identification of autoantibodies in rheumatic diseases. We studied sera from 90 patients. Anti-U1RNP, anti-Sm, anti-Ro/SS-A, anti-La/SS-B, anti-Jo 1 and anti-Scl 70 antibodies were identified by counterimmunoelectrophoresis (CIE) techniques, enzyme-linked immunosorbent assay (ELISA), immunoblotting (IB) using extracts of rabbit thymus and human placenta, and an automated multiparameter line immunoassay system (INNO-LIA ANA UPDATE K-1090) that detects nine different antibodies simultaneously (anti-U1RNP, anti-Sm, anti-Ro/SS-A, anti-La/SS-B, anti-Scl 70, anti-Jo 1, anticentromere, antihistone, and antiribosomal P protein). The line immunoassay system equaled or surpassed the other techniques in the identification of anti-Sm, anti-La/SS-B, anti-Jo 1 and anti-Scl 70 antibodies (sensitivity 100%, specificity 94-100%) and was similarly effective in the case of anti-U1RNP (sensitivity 87.5%, specificity 93.9%) and anti-Ro/SS-A (sensitivity 91.4%, specificity 87.2%) antibodies. In addition, this technique detected more 52 and 60 kD anti-Ro/SS-A sera than IB. Nine antibodies can be detected with this method at a cost of 25.38 Euros per serum sample. In five hours, 19 sera can be studied. The approximate cost of detecting these nine antibodies with an automated ELISA system would be 28.93 Euros, which allows 10 sera to be studied in four hours. In conclusion, the automated multiparameter line immunoassay system is a valid method for the detection of autoantibodies in rheumatic diseases. Its most notable advantages are automated simultaneous detection of several autoantibodies in the same serum and its lower cost compared with ELISA techniques.

Antibodies, Antinuclear↗
PubMed2002

Atmospheric quality and distribution of heavy metals in Argentina employing Tillandsia capillaris as a biomonitor.

The atmospheric quality and distribution of heavy metals were evaluated throughout a wide region of Argentina. In addition, the biomonitor performance of Tillandsia capillaris Ruiz & Pav. f. capillaris was studied in relation to the accumulation of heavy metals and to its physiologic response to air pollutants. A sampling area of 50,000 km2 was selected in the central region of the Argentine Republic. This area was subdivided into grids of 25 x 25 km. Pools of T. capillaris, where present, were collected at each intersection point. From each pool three sub-samples were analyzed independently. Furthermore, five replicates were collected at 20% of the points in order to analyze the variability within the site. The content of Co, Cu, Fe, Ni, Mn, Pb and Zn was determined by Atomic Absorption Spectrometry. Chemical-physiological parameters were also determined to detect symptoms of foliar damage. Chlorophylls, phaeophytins, hydroperoxy conjugated dienes, malondialdehyde and sulfur were quantified in T. capillaris. Some of these parameters were used to calculate a foliar damage index. Data sets were evaluated by one-way ANOVA, correlation analysis, principal component analysis and mapping. Geographical distribution patterns were obtained for the different metals reflecting the contribution of natural and anthropogenic emission sources. According to our results it can be inferred that Fe, Mn and Co probably originated in the soil. For Pb, the highest values were found in the mountainous area, which can be attributed to the presence of Pb in the granitic rocks. Ni showed mainly an anthropogenic origin, with higher values found in places next to industrial centers. For Zn the highest values were in areas of agricultural development. The same was observed for Cu, whose presence could be related to the employment of pesticides. The foliar damage index distribution map showed that the central and southeastern zones were the ones where the major damage in the bioindicator was found. The central zone coincides with the city of Córdoba whereas the southeastern area is strictly agricultural, so the high values found there could be related to the use of pesticides.

Agriculture↗
PubMed2000

Chemical response of transplanted lichen Canomaculina pilosa to different emission sources of air pollutants.

The lichen Canomaculina pilosa was transplanted to 21 sampling sites, plus two controls sites in a north-western area of Córdoba City, Argentina. The transplantation sites were set according to traffic levels, industry condition and distances from the power plant. On the transplanted lichens chlorophyll a, chlorophyll b, phaeophytin a, soluble proteins, hydroperoxy-conjugated dienes, malondialdehyde concentration and sulphur accumulation were determined. A pollution index was calculated for each sampling site. The present study provides information about chemical parameters showing variations as the response of C. pilosa to different emission sources of air pollutants. The C. pilosa chemical response was mainly associated to industries. Significant higher values were observed in phaeophytin a/chlorophyll a ratio, sulphur content and pollution index values in lichen material transplanted at sites with industry. For the distance from the power plant category, only the hydroperoxy-conjugated dienes concentration showed significant differences. For the different traffic levels no significant variations were observed for any of the chemical parameters quantified.

Journal Article↗
PubMed1999

Immunological and clinical differences between juvenile and adult onset of systemic lupus erythematosus.

INTRODUCTION: Systemic lupus erythematosus (SLE) in children usually follows a more severe course than in adults, but sometimes in the previous studies reported there are many confounding factors. OBJECTIVE: To analyse the immunological and clinical characteristics of SLE juvenile onset and SLE adult onset. METHODS: We studied 179 patients with SLE, 49 patients were aged 6-18 yrs at onset of disease. Anti-dsDNA antibodies were detected by radioimmunoassay and antibodies to extractable nuclear antigens (ENA): anti-nRNP, anti-Sm, anti-Ro/SS-A and anti-La/SS-B antibodies by ELISA, counterimmuno-electrophoresis and immunoblotting. RESULTS: Juvenile-onset SLE shows a higher frequency of cutaneous vasculitis (44.8% vs 27.6%; P < 0.05), seizures (18.3% vs 7.6%; P < 0.05) nephropathy (67.3% vs 48.4%; P < 0.025), and discoid lupus erythematosus (26.5% vs 13.8%; P < 0.05). The incidence of articular manifestations is lower than in adults (85.7% vs 96.1%; P < 0.025). No significant differences were found between the two groups in relation with the prevalence of antinuclear antibodies. CONCLUSIONS: Juvenile-onset SLE has more frequent neurological and renal manifestations than adult-onset SLE, but immunological markers are similar in both groups. These features suggest the most severe clinical manifestations in the juvenile-onset SLE group are not related with the presence of studied antibodies by different methods.

Adolescent↗
PubMed1998

Antiribonucleoprotein antibodies in children with HIV infection: a comparative study with childhood-onset systemic lupus erythematosus.

A number of clinical and laboratory features of HIV infection are found in systemic lupus erythematosus (SLE). The objective of this study was to analyze the presence of circulating antibodies to small nuclear ribonucleoproteins (snRNP) in both diseases. Sera from 44 HIV-infected children, from 22 patients with childhood-onset SLE, and from 50 healthy children were studied. Anti-snRNP antibodies were detected by ELISA using recombinant and affinity-purified nuclear antigens, by counterimmunoelectrophoresis (CIE), and by immunoblotting using extractable nuclear antigens. Results included the detection of anti-snRNP antibodies by ELISA in 30 HIV-infected patients (68.1%) and 19 SLE patients (86.3%). These antibodies were directed against U1-RNP (61.3% and 77.2%, respectively), Sm (29.5% and 54.5%, respectively), 60 kDa Ro/SS-A (47.7% and 50%, respectively), and La/SS-B proteins (18.1% and 9%, respectively). None of the HIV-infected children and 11 SLE patients (50%) showed anti-snRNP antibodies by CIE. None of the HIV-infected patients showed anti-70 kDa U1-RNP or anti-D-Sm antibodies by immunoblotting. No differences between the two groups were noted on the presence of nonprecipitating anti-snRNP antibodies. No such reactivities were observed among the normal sera tested. The authors concluded that nonprecipitating anti-snRNP antibodies in HIV-infected children are as frequent as in childhood-onset SLE. The significance of these antibodies is not clear at present. Although polyreactive and low-affinity antibodies and a mechanism of molecular mimicry may explain these results, a specific stimulation of B cells by nuclear antigens could not be excluded.

Adolescent↗
PubMed1998

Anti-BB'-Sm antibodies, anticardiolipin antibodies, and thrombosis in systemic lupus erythematosus.

OBJECTIVE: Anticardiolipin antibodies (aCL) are associated with thrombosis in patients with systemic lupus erythematosus (SLE). Our aim was to determine whether there is an association between aCL, anti-Sm antibodies, and thrombosis in patients with SLE. METHODS: Sera from 153 patients with SLE were studied by ELISA, immunoblotting, and counter-immunoelectrophoresis (CIE) for anti-Sm antibodies, aCL and anti-dsDNA antibodies were detected by ELISA and radioimmunoassay, respectively. RESULTS: Anti-Sm antibodies were detected in 62 patients (40.5%) by ELISA and in 16 (10.4%) by CIE; IgG-anti-BB'-Sm in 44 (28.7%) by immunoblotting; IgG-aCL in 82 (53.5%), IgM-aCL in 44 (28.7%), and anti-dsDNA antibodies in 128 (83.6%). Anti-Sm and anti-dsDNA antibodies were significantly more frequent in patients with than in patients without aCL. Of the 89 patients with aCL, 36 (40.4%) showed IgG-anti-BB'-Sm antibodies (OR: 4.7; 95% CI: 2-10.5). Thrombosis was present in 20 (22.4%) SLE patients with aCL and in two (3.1 %) SLE patients without aCL (OR: 8.9; 95% CI: 2.4-31.8). Of the 22 patients with thrombosis, five (22.7%) had precipitating anti-Sm antibodies (OR: 3.2; 95% CI: 1.04-9.8) and 14 (63.6%) showed IgG-anti-BB'-Sm antibodies (OR: 5.8; 95% CI: 2.3-14). Anti-BB'-Sm and aCL were significantly more frequent in patients with anti-dsDNA antibodies (32 and 62%) than in patients without these antibodies (12 and 36%) (OR: 3.4 and 2.9; 95% CI: 1.03-11.1 and 1.2-6.7, respectively). CONCLUSION: IgG-anti-BB'-Sm antibodies are associated with aCL, anti-dsDNA, and thrombosis in patients with SLE. Our findings suggest a possible association between anti-Sm, anti-dsDNA, and aCL responses in these patients.

Adult↗
PubMed1997

Chemical response of the lichen Punctelia subrudecta (Nyl.) Krog transplanted close to a power station in an urban-industrial environment.

The lichen Punctelia subrudecta (Nyl.) Krog was transplanted to 22 biomonitoring sites in a northwestern area of Córdoba city, Argentina and tested for chlorophyll a, chlorophyll b, phaeophytin a, soluble protein, hydroperoxy conjugated dienes (HPCD), malondialdehyde (MDA) concentration and sulphur accumulation. A pollution index (PI) was calculated for each biomonitoring site. The biomonitoring sites were set according to (1) traffic levels, (2) industrial density and (3) distance of the power station close to each site. The biomonitor's chemical response was associated with industries as well as power stations. Significant differences were observed in sulphur content, MDA concentration and PI values in lichen material transplanted to sites with different industrial densities. The higher values for these parameters were found at sites with high industrial levels. At the same time, significant differences were detected for sulphur content in samples at different distances from the power station, with higher accumulation in samples located far from the power plant. For MDA concentration, effect of different levels of industrial density was observed only at points close to the power station, probably because of higher levels of humidity near the power plant. For PI significantly higher values were observed in samples at points far from the power station and with high industrial density. This shows the additive effect of the principal emission sources that act on the response of P. subrudecta to air pollutants.

Journal Article↗
PubMed1997

Systemic lupus erythematosus: clinical expression and anti-Ro/SS--a response in patients with and without lesions of subacute cutaneous lupus erythematosus.

UNLABELLED: Patients with subacute cutaneous lupus erythematosus (SCLE) have recurrent annular and/or psoriasiphorm skin lesions, with or without systemic disease. OBJECTIVE: To analyse the clinical expression and the Ro/SS-A response associated with SCLE in patients with systemic lupus erythematosus (SLE). METHODS: 128 consecutive patients with SLE were studied. Anti-Ro/SS-A antibodies were detected by ELISA, (anti-60 kD Ro/SSA antibodies), immunoblotting (anti-60 kD and anti-52 kD Ro/SS-A antibodies) and counterimmunoelectrophoresis (CIE). RESULTS: Seventeen patients (13.2%) showed SCLE lesions. Photosensitivity was more frequent in patients with SCLE (82%) than in patients without these cutaneous lesions (45%) (OR: 5.6). Arthritis (OR: 6.3), Raynaud's phenomenon (OR: 4.9), pleuritis (OR: 7.6), central nervous system disorder (OR: 6.4), renal disease (OR: 6.3), anemia (OR: 7.9), hypocomplementemia (OR: 6.1) and anti-dsDNA antibodies (OR: 12.7) were significantly more frequent in patients without SCLE. Anti-Ro/SS-A antibodies were detected in 15 (88.2%) patients with SCLE and 62 (55.8%) patients without SCLE by ELISA, in 10 (58.8%) and 34 (30.6%) patients by immunoblotting, and in 13 (76.4%) and 34 (30.6%) by CIE, respectively. Anti-60 kD-Ro/SS-A and anti-La antibodies, but not anti-52 kD-Ro/SS-A, were significantly more frequent in patients with SCLE than in patients without SCLE. CONCLUSIONS: The presence of SCLE lesions in patients with SLE is associated with a more favourable prognosis. The major anti-Ro/SS-A response is directed against the native 60 kD Ro/SS-A protein.

Adult↗
PubMed1996

Abdominal scintigraphy using 99mTc-HMPAO-labelled leucocytes in patients with seronegative spondylarthropathies without clinical evidence of inflammatory bowel disease.

Abdominal scintigraphy with technetium-99m hexamethylpropylene amine oxime (99mTc-HMPAO)-labelled leucocytes is an excellent tool for evaluating disease extent and activity of intestinal lesions in patients with inflammatory bowel disease (IBD). In some cases of seronegative spondylarthropathies (SSp), IBD may remain subclinical. The aim of this study was to evaluate the presence of positive abdominal scintigraphy in patients with SSp and without clinical symptoms or signs of IBD. To this end we studied 32 patients with active SSp (European Spondylarthropathy Study Group 1991 criteria) without clinical evidence of IBD (eight had ankylosing spondylitis, four psoriatic arthritis, three reactive arthritis an 17 undifferentiated SSp) and 11 controls without SSp. All SSp and control patients received similar doses of non-steroidal anti-inflammatory drugs (NSAIDs). Abdominal scintigraphic images were obtained at 30 and 120 min after re-injection of 99mTc-HMPAO-labelled leucocytes. The 99mTc-HMPAO-labelled leucocyte scan was positive in 17 patients with SSp (53.1%) (six with ankylosing spondylitis, three with psoriatic arthritis, two with reactive arthritis and six with undifferentiated SSp). Fourteen patients scored from 2 to 4 on the intensity of uptake scale. The colon and terminal ileum were predominantly involved. Axial involvement was more frequent in patients with a positive scan than in patients with negative results (P<0.05) (64.7% vs 26.6%; odds ratio: 5). No control patient showed a positive scan. It is concluded that 99mTc-HMPAO-labelled leucocyte scan shows increased uptake among patients with SSp without evidence of IBD. These findings provide new evidence linking SSp with intestinal inflammation and suggest that in some cases a bowel-related process could contribute to the development of SSp. Long-term follow-up studies with more patients are necessary to evaluate the diagnostic and therapeutic implications of these results.

Abdomen↗
PubMed1996

Biomonitoring of air pollutants from traffic and industries employing Ramalina ecklonii (Spreng.) Mey. and Flot. in Córdoba, Argentina.

The lichen Ramalina ecklonii (Spreng.) Mey. and Flot. was transplanted to 29 biomonitoring sites in the southeastern area of Córdoba, Argentina and tested for chlorophyll a, phaeophytin a, conjugated dienes concentration, malondialdehyde, soluble protein content and sulfur accumulation. The biomonitoring sites were determined according to (i) vehicular traffic levels, and (ii) industrial density, i.e. number and type of industries (small and medium) close to each of the sites. Each of the two groups were then broken down into three categories which provided a basis for performance analysis and quantification of the chemical parameters in the biomonitor. A pollution index (P.I.) was calculated based on the ratio of phaeophytin a to chlorophyll a and ratio of sulfur, malonaldehyde and conjugated dienes in transplanted specimens to sulfur, malonaldehyde and conjugated dienes in the freshly picked specimens. Significant differences were observed in sulfur content and P.I. in lichen samples that had been transplanted to sites with different vehicular traffic levels. At the same time, significant differences in the phaeophytin a concentration, phaeophytin a/chlorophyll a ratio and P.I. were observed at sites characterized by different levels of industrial density (all with low-to-medium traffic).

Journal Article↗
PubMed1996

Antiribonucleoprotein antibodies in children with human immunodeficiency virus infection: comparative study with childhood-onset systemic lupus erythematosus.

UNLABELLED: A number of clinical and laboratory features of human immunodeficiency virus (HIV) infection are found in systemic lupus erythematosus (SLE). OBJECTIVE: To analyze the presence of circulating antibodies to small nuclear ribonucleoproteins (snRNP) in both diseases. METHODS: We studied sera from 44 HIV-infected children, from 22 patients with childhood-onset SLE, and from 50 healthy children. Anti-snRNP antibodies were detected by (ELISA) using recombinant and affinity-purified nuclear antigens, by counterimmunoelectrophoresis (CIE), and by immunoblotting using extractable nuclear antigens. RESULTS: Anti-snRNP antibodies were detected by ELISA in 30 HIV-infected patients (68.1%) and 19 SLE patients (86.3%). These antibodies were directed against U1-RNP (61.3% and 77.2%), Sm (29.5% and 54.5%), 60kD-Ro/SS-A (47.7% and 50%), and La/SS-B proteins (18.1% and 9%), respectively. None of the HIV-infected children and 11 SLE patients (50%) showed anti-snRNP antibodies by CIE. None of the HIV-infected patients showed anti-70 kD U1-RNP or anti-D-Sm antibodies by immunoblotting. No differences between the two groups were noted relative to the presence of nonprecipitating anti-snRNP antibodies. No such reactivities were observed among the normal sera tested. CONCLUSIONS: Nonprecipitating anti-snRNP antibodies in HIV-infected children are as frequent as in childhood-onset SLE. The significance of these antibodies is not clear at present. Perhaps they are polyreactive and low-affinity antibodies and a mechanism of molecular mimicry may explain these results; however, we cannot exclude a specific stimulation of B-cells by nuclear antigens.

Adolescent↗
PubMed1995

Different abdominal scintigraphy pattern in patients with ulcerative colitis, Crohn's disease and seronegative spondylarthropathies.

The aim was to analyse the abdominal scintigraphy pattern in patients with seronegative spondylarthropathy (SSp), ulcerative colitis (UC) and Crohn's disease (CD). A total of 117 patients with defined histological lesions of inflammatory bowel disease (IBD) (68 UC and 49 CD), 32 patients with active SSp [European Spondylarthropathy Study Group (ESSG) 1991 criteria] without clinical evidence of IBD and 21 controls without IBD or SSp were studied. All patients with SSp and controls received similar doses of non-steroidal anti-inflammatory drugs. Abdominal scintigraphy images were obtained at 30 and 120 min after injection of 99m-technetium hexamethyl propylene amine oxime (99mTc-HMPAO)-labelled leucocytes. The 99mTc-HMPAO-labelled leucocyte scan was positive in 17 patients with SSp (53.1%), 45 patients with UC (66.1%) and 33 patients with CD (67.3%). Rectum and sigma involvement was more frequent in patients with UC (68.8%) than in patients with SSp (23.5%) or CD (33.3%) (P < 0.05) [odds ratios (OR): 7.1 and 4.4, respectively]. Terminal ileum involvement was more frequent in patients with CD (63.6%) than in patients with SSp (23.5%) or UC (8.8%) (P < 0.05) (OR: 5.6 and 17.9, respectively). The 99mTc-HMPAO-labelled leucocyte scan shows an increased uptake in patients with SSp without evidence of IBD. Perhaps these patients represent one end of the spectrum of IBD, but rectal and terminal ileum involvement were less frequent in patients with SSp than in patients with UC or CD.

Abdomen↗
PubMed1994

[Clinical and serologic course of patients with mixed connective tissue disease].

The so called mixed connective tissue disease (MCTD), continues to be a controversial entity, while some authors considered it a good characterized disease, others think that is an undifferentiated connective tissue disease. OBJECTIVE. To analyse the clinical and serological evolution of a group of patients diagnosed of MCTD, with particular consideration to the meaning of anti-nRNP and anti-Sm antibodies. METHOD. We have studied 20 patients diagnosed of MCTD and 112 with systemic lupus erythematosus (SLE). Anti-nRNP and anti-Sm antibodies were detected through counter immunoelectrophoresis, immunoblotting and ELISA. RESULTS. After an average time of evolution of 10 years, 70% (14/20) of the patients diagnosed of MCTD fulfill criteria for SLE (6 cases), scleroderma (6 cases) or polymyositis (2 cases). Anti-nRNP response is persistent, directed mainly against the 70 Kd and A-nRNP polypeptides and qualitatively higher in MCTD in SLE (absorbencies 2.64 vs 1.25. The immunoblotting test detected anti-Sm antibodies in 5 patients (25%) and ELISA test in 14 (70%). CONCLUSIONS. Clinical and serological evolution suggest that MCTD is an undifferentiated connective tissue disease. Anti-nRNP antibodies are characteristic, although anti-Sm antibodies can be detected with ELISA regardless whether on not patients fulfill SLE criteria.

Adolescent↗
PubMed1985

[Childhood benign chronic bullous dermatosis. Differential diagnosis with dermatitis herpetiformis and bullous pemphigoid].

We review the literature on benign chronic bullous dermatosis of childhood and the criterions for its diagnosis and differentiation from dermatitis herpetiformis and bullous pemphigoid. The diagnosis among these conditions should be based on immunofluorescence data. BCBDC shows linear IgA on the basal membrane zone. Its course is benign and there is not enteropathy. In dermatitis herpetiformis we find granular IgA and complement in the tips of dermal papillae. It is a chronic illness and the patients have a gluten-sensitive enteropathy. The bullous pemphigoid is a severe condition which needs corticosteroids for its control. Direct immunofluorescent studies reveal IgG and complement in a linear pattern in the membrane basal zone. It is associated with circulating antibasement membrane zone IgG.

Child↗