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J Paniagua

Publications and source records attributed to J Paniagua.

At least 19 recordsLinked to original sources
PubMed1999

[The prognostic value of dobutamine echocardiography after an uncomplicated acute myocardial infarct].

BACKGROUND AND PURPOSE: The identification of patients at risk for future events after an infarction is mandatory. The aim of this study was to assess the prognostic value of dobutamine stress echocardiography after an uncomplicated myocardial infarction. METHODS: One hundred and twenty five patients (mean age 65 +/- 11 years, males 82%) underwent dobutamine-echo within ten days after an uncomplicated myocardial infarction. Four myocardial responses were identified: a) negative; b) sustained improvement of myocardial contractility; c) initial improvement followed by worsening, and d) worsening at a distance or in the infarcted zone. RESULTS: Mean follow-up was 7.4 +/- 4.6 months. An adverse outcome occurred in 47 patients: non cardiac death in 3, cardiac death in 6, myocardial infarction in 5, angina in 21, congestive heart failure in 2, and in 10 patients revascularization. Cox regression analysis showed that worsening of contractility was the best predictor for adverse events (p < 0.0001, relative risk 2.8; 95% confidence interval: 1.7-4.5). Non-smoking and previous angina were also predictors of adverse events (p = 0.003 and p = 0.04, respectively). Similar results were obtained after excluding the revascularized patients. CONCLUSIONS: Sustained improvement of contractility in the infarcted region is not a predictor of adverse events. Asynergy at a distance or in the infarcted region during dobutamine echocardiography within ten days after an uncomplicated myocardial infarction predicts adverse cardiac events during follow-up. Therefore, dobutamine echocardiography could be used for risk stratification after acute myocardial infarction.

Aged↗
PubMed1998

[Image processing in the primary visual cortex].

INTRODUCTION: Area 17 or the primary visual area forms the first link in the chain of cerebral analysis of a visual image. The neurones forming the primary visual cortex are characterized by the extreme precision of their connections, functional specialization and hierarchic organization. The spatial precision of the connections within the system for vision permit retinotopic representation in the visual cortex, so that each point of the retina is projected into a specific area of the cortex. The cortical neurones which analyze the characteristics of the image situated in a precise zone of the visual field are themselves organized into a basic functional unit known as a hypercolumn. Within each hypercolumn there are various columnar cell systems with receptive fields having similar characteristics. Thus, each hypercolumn is made up of multiple orientation columns, two ocular dominance columns and 'blob' regions. All these systems permit the analysis of different aspects of the image. The neurones belonging to the orientation columns are sensitive to the orientation, spatial frequency and movement of a visual stimulus; those of the 'blob' regions to colour, and the binocular neurones of the ocular dominance columns to depth. Within each column, the hierarchical pattern of neurone interconnections determines the successive appearance of cells with receptive fields having new properties.

Geniculate Bodies↗
PubMed1995

Prevalence of antibodies against Entamoeba histolytica in Mexico measured by ELISA.

The prevalence of antibodies against Entamoeba histolytica was studied in the Mexican population using an immunoenzyme assay in solid phase (ELISA) and semiautomatic equipment. The antigen was a mixture of membrane proteins obtained by Triton X-100 extraction from an axenic culture of Entamoeba histolytica HM1-IMSS. The method was standardized by comparing serum samples from amoebic liver abscess patients with healthy volunteers. From the 60,538 samples supplied by the National Seroepidemiology Survey, antibodies were found in 4.49% (4.32-4.65% at 95% confidence limit). More significant titres occurred in the central region of the country. The ratio female to male was 1.25:1. The population living in metropolitan areas had probably been infected at a younger age than those living in the country. Important differences were found in the seroprevalence obtained by ELISA compared with a study which used indirect haemagglutination (IHA) in the same sample frame.

Adolescent↗
PubMed1995

Immune response to porins isolated from Salmonella typhi in different mouse strains.

Outer membrane proteins (OMPs) are able to induce protection against the challenge with S. typhi in a murine model. Both humoral and cellular immunity are involved in the protective mechanisms. In order to determine whether the responsiveness to S. typhi porins is genetically controlled in mice, different strains were immunized i.p. with 30 micrograms of OMPs isolated from S. typhi 9,12,Vi:d at days 0 and 7. On day 21, spleen cells were recovered and the lymphoproliferative response to porins was assessed. The highest responses were found in mice with H-2k and H-2a haplotypes (C3H/HeJ and A/J), intermediate responses were found in mice with H-2b haplotype (C57Bl/6) and the lowest responses in H-2d mice (Balb/c). These results demonstrate that the responsiveness to S. typhi porins is in part controlled by the major histocompatibility complex class II molecules and will help to further study the mechanisms of the immune response to these proteins.

Animals↗
PubMed1993

Thoracic complications of deeply situated serous neck infections.

Nine cases of complicated deep neck infections, occurring during a period of twelve years are presented. Complications observed were cervico-thoracic necrotizing fasciitis in 3 cases, purulent pleural effusion in 6 cases, pericardial effusion in 2, mediastinitis in 8 cases, jugular vein thrombosis and rupture of the innominate artery in one case each. Although 2 cases were managed initially with blind endotracheal intubation, all cases finally required tracheostomy. A cervico-mediastinal approach was useful for the early mediastinal involvement. Two patients died because of inadequacy of the multiple surgical procedures resulting in persistent infection and multi-organ failure and one because of uncontrollable bleeding after innominate artery rupture.

Adolescent↗
PubMed1993

Lymphocytic proliferative response to outer-membrane proteins isolated from Salmonella.

Porins isolated from Salmonella typhi have been demonstrated to protect against the challenge with this bacteria in mice. The mechanism has not been clarified, but could be associated with activation of both humoral and cellular immunity. In order to evaluate the induction of specific T cell responses, the lymphocytic proliferation to porins isolated from Salmonella typhimurium, Salmonella typhi and Escherichia coli was examined by 3H-thymidine incorporation assay in mice immunized with three different antigens: acetone-killed S. typhimurium, its porins, or outer-membrane proteins (OMPs) isolated from S. typhi. Higher proliferative responses were observed in mice immunized with porins and OMPs compared with those which received the acetone-killed bacteria. Although cross-reactivity was observed between porins, they were not mitogenic. Moreover, porins were able to activate T lymphocytes isolated from mice immunized with S. typhi OMPs. These results suggest that T cell activation, through the release of lymphokines, may play a role in the induction of protective immunity with porins.

Animals↗
PubMed1993

Human cell mediated immunity to porins from Salmonella typhi.

The current studies were undertaken to assess the role of the porins and outer membrane proteins (OMP) in the human immune response to Salmonella typhi 9, 12 Vi:d. Experiments were performed to determinate the lymphocyte activation response to porins in individuals who had been vaccinated against typhoid fever. 10 healthy volunteers were studied before and 10 days after oral or subcutaneous immunisation. Five patients with typhoid fever were also studied. Lymphocyte activation was measured by the 3H thymidine incorporation assay. Individuals with typhoid fever as well as those immunised with oral vaccine responded well to porins and outer membrane proteins, as opposed to those immunised with the subcutaneous vaccine. These results suggest that the porins and OMP play a role in the cellular immune response against Salmonella typhi.

Administration, Oral↗
PubMed1992

Active protection of mice against Salmonella typhi by immunization with strain-specific porins.

NIH mice were immunized with between 2.5 and 30 micrograms of two highly purified porins, 34 kDa and 36 kDa, isolated from the virulent strain Salmonella typhi 9,12, Vi:d. Of mice immunized with 10 micrograms of porins, 90% were protected against a challenge with up to 500 LD50 (50% lethal doses) of S. typhi 9,12,Vi:d and only 30% protection was observed in mice immunized with the same dose of porins but challenged with the heterologous strain Salmonella typhimurium. These results demonstrate the utility of porins for the induction of a protective status against S. typhi in mice.

Animals↗
PubMed1990

[Obtaining monoclonal antibodies against outer membrane glycoproteins of Entamoeba histolytica].

The goal of this paper was the production of monoclonal antibodies capable of detecting relevant antigens from the surface of Entamoeba histolytica trophozoites, with the purpose of using them as a diagnostic test. The cellular fusion for obtaining the monoclonal antibodies (mAb) was done with spleen cells from BALB/c mice, previously immunized with glycoproteins from the membrane, as well as Sp2/0 cells. The hybridoma supernatants were tested with ELISA, using glycoproteins and lipopeptide phosphoglycans (LPPG) as antigens. Seven hybridomas producing mAb against the glycoproteins were found. Among these, three recognize LPPG. The ability of reacting with the mAb against two molecules disappeared for all the LPPG positive ones when were treated with meta-periodate, and only three reacted against the glycoproteins. All of the mAb were of the Ig M isotypes. They were characterized by Dot blot and Western blot assays. From the results, one may deduce that some mAb recognize as epitopes the polysaccharide portion, and thus infer that they are directed of against the surface and therefore, in the future, could be used with a diagnostic purpose.

Animals↗
PubMed1990

[Seroepidemiology of amebiasis in the northern region of the Republic of Mexico].

The object of paper has been the study of amebic seroepidemiology in the northern region of Mexico, by means of an immunoenzymatic assay in solid phase (ELISA). The proteic antigen was obtained from axenic culture of E. histolytica's trophozoites of strain HM1:IMSS, by means of solubilization with phenoxy polyethoxyethanol (Triton X-100). Standardization of the method was obtained by analysis of 80 sera from patients with both a clinical and radiologic diagnosis of amebic hepatic abscess and 80 sera from healthy patients. The sensitivity reached 95% and the specificity was 90.7%. 15,457 sera from eight Mexican northern states were tested as part of the National Seroepidemiologic Survey. A semiautomatic BIOMEK 1,000 (Beckman Ins.) equipment was used. The positive ratio varied between 2.0% in Southern Baja California and 4.92% in Chihuahua, with an average ratio for the whole group of 3.34%. The first three places, in descending order, are Chihuahua (4.92%), Sinaloa (4.01%) and Northern Baja California (3.78%). The positive man: woman ratio was 0.87:1 and fluctuated between 0.38:1 in Coahuila and 1.76:1 in Nuevo Leon. In the whole sample the positive ratio of men was 3.00% and in women was 3.43%. The antibody profile related to age, is similar to diseases reported to be highly endemic; the percentage of positive sera rose progressively up to the age of 20 years (4.05%), at which a plateau occurred with a slight descending tendency up to 60 years of age (3.54%), after which a clear descent in the positive index is seen. No important variations were observed when comparing groups of ages and sexes. The antibody level seems to show an inverse relationship with the incidence rate of amebiasis.

Adolescent↗
PubMed1989

[Study of lipids (cholesterol, triglycerides and phospholipids), plasma lipoproteins (HDL-cholesterol) and apoproteins (apo A and apo B in patients with acute myocardial infarction].

Several lipid parameters were evaluated in 88 patients with acute myocardial infarction (AMI). A reduction in cholesterol and phospholipid level was observed, with minimal values between the days 10-20, followed by a subsequent increase. Triglycerides increased after 12-14 hours, with a maximal value after 20-30 days. Cholesterol bound to high-density lipoproteins (HDL-cholesterol) decreased after 24 hours, with a minimal value after 20-30 days. Apoprotein A decreased from the initial measurement until days 20-30. The initial lipid profile (indicating the risk of coronary artery disease) was constituted by high cholesterol (particularly in males below 60 years), high triglyceride and low HDL-cholesterol levels. The latter finding was more marked and characteristic in the overall group of evaluated patients. All values were compared with a control group of 24 healthy persons. Relevant data for prognosis included the following: males above 60 years had a greater reduction in cholesterol and apoprotein A during AMI; the males who died had lower apoprotein A levels than the survivors; females with higher haptoglobin levels also had higher apoprotein B levels. All these findings were statistically significant (p less than 0.01).

Aged↗
PubMed1988

Protection against Salmonella typhi infection in mice after immunization with outer membrane proteins isolated from Salmonella typhi 9,12,d, Vi.

The current studies were undertaken to assess the ability of the outer membrane proteins (OMPs) of Salmonella typhi to induce protection against challenge with the bacteria in mucin. OMPs were isolated as described by Schnaitman (J. Bacteriol. 108:553-556, 1971) and were found to be contaminated with approximately 4% lipopolysaccharide (LPS). Immunization with as little as 30 micrograms of OMPs conferred 100% protection to mice challenged with up to 1,000 50% lethal doses (LD50) of two strains of S. typhi (9,12,d, Vi and Ty2). In addition, 30% protection against challenge with up to 500 LD50 of Salmonella typhimurium was achieved. Immunization with LPS at doses equivalent to those found in the OMPs was considerably inferior to the OMPs in the induction of an immune status. Moreover, LPS was effective only when the challenge was performed with S. typhi 9,12,d, Vi (40% protection to 100 LD50). An antiserum raised in rabbits reacted mainly against the bands of the molecular weights corresponding to the so-called porins contained in the OMP preparation as shown by Western blotting (immunoblotting). This rabbit antiserum protected 100% of mice against challenge with 100 LD50 of either strain of S. typhi and 80% of mice against challenge with the same LD50 of S. typhimurium. These results indicate the usefulness of OMPs in the induction of active immunity against S. typhi in mice.

Animals↗
PubMedDate not supplied

Immunogenicity of a Salmonella typhi CVD 908 candidate vaccine strain expressing the major surface protein gp63 of Leishmania mexicana mexicana.

Attenuated Salmonella typhi are attractive for use as live vector vaccines to express protozoal antigens and deliver them to the human immune system. The gene encoding the mature form of Leishmania mexicana mexicana gp63 under control of tac promoter was integrated into the delta aroC locus of the chromosome of attenuated delta aroC, delta aroD S. typhi strain CVD 908. After oral immunization of BALB/c mice with two 1 x 10(9) colony forming unit doses given 21 days apart, CVD 908 omega (delta aroC::Ptac-gp63) elicited a broad T cell-mediated immune response against L. m. mexicana gp63 as demonstrated by: (1) lymphoproliferative response to fixed whole L. m. mexicana promastigotes; (2) activation of IL-2 (but not IL-4)-producing lymphocytes; (3) appearance of cytotoxic T cells against mouse mastocytoma cells expressing gp63. This T-cell mediated immune response was associated with significant protection in F1 (BALB/cXC57Bl/6) mice challenged in their footpads with a wild type strain of L. m. mexicana.

Administration, Oral↗
PubMedDate not supplied

[Conjugate vaccines against bacterial infections: typhoid fever].

Capsular polysaccharides have been studied as possible vaccines against infectious diseases. However, they are capable to induce only short-run protection because of their T-independent properties and they would not be protective against infection in high-risk populations. The alternative to face this problem is to develop methods to join covalently the polysaccharide and proteins to both increase the immunogenicity of and to confer the property of T-dependence to this antigen. In order to obtain a conjugate vaccine against typhoid fever, in our laboratory we have tried to synthesize a conjugate immunogen between the Vi antigen and porins from Salmonella typhi.

Adolescent↗