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J L Subiza

Publications and source records attributed to J L Subiza.

At least 19 recordsLinked to original sources
PubMed1995

Involvement of nitric oxide in bone marrow-derived natural suppressor activity. Its dependence on IFN-gamma.

Bone marrow (BM)-derived natural suppressor (NS) cells are strong inhibitors of lymphoproliferative responses. In this study we have assessed the involvement of nitric oxide (NO) in BM-derived NS activity, as detected in cocultures of BM and spleen cells stimulated with B cell (LPS) or T cell (Con A) mitogens. The results indicate that NS activity is readily inhibited by NG-monomethyl-L-arginine, a competitive inhibitor of NO synthase, or N-acetylcysteine, a free radical-scavenging thiol compound. High amounts of nitrite, a stable end product of NO, are detected only in supernatants of Con A- or LPS-stimulated spleen cells cocultured with BM cells enriched in NS activity (Fr3 cells). These amounts (15 to 55 microM) are strongly antiproliferative for both Con A and LPS responses, as was established with a nitrite curve made with a NO donor (sodium nitroprusside). Fr3 cells cultured alone release large quantities of NO and express inducible NO synthase (iNOS) mRNA upon LPS stimulation, but require spleen cells in cultures stimulated with Con A. Anti-IFN-gamma-neutralizing Abs blocked both NO production and NS activity, irrespective of the mitogen used; yet, only exogenous IFN-gamma is unable to promote successful NO production by Fr3 cells, but does induce detectable iNOS mRNA expression in these cells. Taken together the results indicate that: 1) NO is the major mediator of BM-derived NS activity; 2) BM cells enriched in NS activity produce large amounts of NO through an IFN-gamma-dependent iNOS induction.

Acetylcysteine↗
PubMed1994

Seasonal asthma caused by airborne Platanus pollen.

This work describes three patients suffering from bronchial asthma after being naturally exposed to airborne plane-tree pollen. The three patients gave immediate response in skin tests and dual response in bronchial provocations using Platanus hybrida extract. There was specific seric IgE activity against this/these antigen(s) with the CAP system. The three patients also showed significant correlation (P < 0.001) between their rhinitis and asthma symptom-scores registered on their diary cards and plane-tree pollen counts, collected using the Burkard spore trap. Among 187 patients living in Madrid and who came to our centre with a history of rhinitis and/or seasonal asthma, we found a prevalence of positive skin-prick tests to Platanus of 56%, only surpassed by gramineous pollen (Dactylis glomerata and/or Trisetum paniceum) 92% and Olea europaea 63%. The aerobiological sampling of the pollen content of the air in Madrid, carried out between 1 January 1979 and 31 December 1993 revealed an airborne presence (per cent of total yearly pollen count, mean of 1979-1993) of 14.9% for the Platanus, 14.8% for grasses, 9.8% for Olea and 3.6% for Plantago. The Platanus is one of the most frequently found pollens in the atmosphere over Madrid. At present, in this geographical area, a high percentage of patients with pollinosis are sensitive to this pollen. At least in some of these patients Platanus pollen is capable of inducing rhinitis and bronchial asthma.

Adult↗
PubMed1994

Bakers' asthma caused by alpha amylase.

Two bakers with bronchial asthma and two with rhinoconjunctivitis are described. Prick and RAST tests were positive with wheat flour in all of them, but the challenge test (nasal or bronchial) with wheat flour extract was positive only in one asthmatic baker. The prick test, RAST, and nasal or bronchial challenge done with alpha amylase extract (a glycolytic enzyme obtained from Aspergillus oryzae and used as a flour additive) were positive in all four patients. Our results support previous data indicating that alpha amylase used in bakeries is an important antigen that could cause respiratory allergy in bakers. It can function as sole causative allergen or in addition with other allergens used in the baking industry.

Adult↗
PubMed1992

Tumor cytostasis mediated by a monoclonal IgM antibody promoting adhesion between macrophages and tumor cells. Evidence for a lectin-like behavior.

We have shown previously that an IgM mAb (A10) recognizing Ehrlich tumor (ET) cell surface carbohydrates, inhibits in vivo ET growth by a macrophage-dependent mechanism. The inhibition mechanism involving both IgM and macrophages was unclear because receptors for IgM on macrophages are controversial and another monoclonal IgM (E1), also recognizing ET cell surface carbohydrates, was completely unable to show any protective effect. Here we show that A10, but not E1, was able to promote adhesion between macrophages and ET cells by a receptor for IgM-independent mechanism. Immunofluorescence studies showed that A10, but not E1, did react with macrophages if these cells were preincubated with a source of Ag spontaneously released from ET cells. This Ag release appeared to be required for A10-mediated adhesion, because adhesion was not obtained when ET cells fixed with paraformaldehyde were used. Cytostasis studies performed with macrophages stimulated with L-929 conditioned medium and ET cells showed that A10, but not E1 nor unrelated IgM, was able to inhibit ET cell proliferation in vitro by a mechanism involving cell contact between both cell populations. Therefore, IgM inhibition of ET growth, both in vivo and in vitro, could be explained by a lectin-like mechanism, where IgM, recognizing Ag of tumor origin, bridges macrophages to tumor cells.

Animals↗
PubMed1992

Evidence that a putative anti-idiotypic monoclonal antibody may actually be recognizing circulating immune complexes.

Murine monoclonal antibodies (mAb) reacting with affinity-purified antihistone antibodies (AHA) from serum of a patient with systemic lupus erythematosus (SLE) were obtained. One of them, 8B3, was initially considered to recognize idiotypic (Id) determinants in AHA since (a) it reacted with AHA but not with control IgG; (b) this reactivity could be inhibited using affinity-purified AHA, but not with control IgG or whole serum; (c) affinity-isolated 8B3+ antibodies showed antihistone activity and not other activities tested so far; (d) antihistone activity due to 8B3+, but not that of 8B3- from the same serum, could be fully inhibited by the presence of 8B3 mAb in the antihistone assay and (e) serum levels of 8B3 reactivity were higher than normal in SLE patients with AHA (56%), in contrast with SLE patients without AHA (6%). From these results it was deduced that 8B3 defined a cross-reactive Id shared by a subset of AHA in SLE patients. However, the present results suggest that (a) 8B3 mAb did not recognize AHA or Ig, but did recognize a 55 kDa histone-binding protein; (b) this 55 kDa protein was present free at low concentration in all human sera, but also associated with IgG in 8B3+ SLE sera and (c) these complexes are responsible for the false positive results in the antihistone assay as shown for DNA/anti-DNA complexes. Thus, mAbs recognizing the non-Ig moiety of circulating immune complexes may resemble anti-Id antibodies with features of the so-called epibodies. These immune complexes may be responsible for false positive results and caution should be exercised in the interpretation of results.

Animals↗
PubMed1992

Prediction of annual variations in atmospheric concentrations of grass pollen. A method based on meteorological factors and grain crop estimates.

We performed an aerobiologic observation of the grasses present in Madrid for 14 years (1978-1991), using volumetric air samplers. The counts obtained show that the major grass pollen release period (average daily grass pollen counts greater than 50 grains/m3 of air) occurs in the months of May and June, although lower counts can occur some days from the end of January onward. There are wide year-to-year variations in total atmospheric grass pollen counts, expressed as the total sum of the mean daily concentrations from April 1st to July 30th (ranging from 2568 to 6624). A strong, statistically significant correlation, based on Spearman's rank test and/or simple and multiple linear regressions, was found between the total grass seasonal count and preseasonal rainfall from October to March (R2 = 0.64; P = 0.0429). The meteorological variable which gave the correlation with greatest statistical significance (R2 = 0.97; P = 0.0016) was the average monthly preseasonal humidity from October to March. A good correlation was also found between March estimates of wheat, rye and barley crops and the total grass count (R2 = 0.73; P = 0.006). A model was designed from the above mentioned humidity variable through a multilinear regression analysis, and it was possible to predict, at the beginning of April, total seasonal counts for 1989 (predicted = 5468; actual = 4410; average error = 24%), 1990 (5033; 6090; -17%) and 1991 (3930; 2568; 53%). These data may help clinicians to predict and prepare themselves for the intensity of the grass pollen season and to explain yearly variations in the severity of symptoms.

Agriculture↗
PubMed1991

Antigen shedding vs. development of natural suppressor cells as mechanism of tumor escape in mice bearing Ehrlich tumor.

C57BL/6J mice immunized with devitalized Ehrlich tumor (ET) cells produce high serum levels of IgM antibodies to ET cell-surface carbohydrates that are critical in the observed resistance against this tumor. However, this response is not found in ET-bearing mice at any stage of tumor development. Since previous studies had shown splenic natural suppressor (NS) cells in ET-bearers, their role in such IgM impairment was assessed. Here we show that tumor-bearers' spleen cells (TBSC) are unable to produce IgM in vitro in response to LPS, due to the presence of NS cells. Nevertheless, TBSC do produce IgM antibodies to ET cell-surface carbohydrates in increasing amounts as the tumor progresses. Yet these antibodies are not detected in sera of ET-bearers and are greatly decreased in immunized mice with a growing tumor. Moreover, increasing amounts of circulating carbohydrates, able to absorb most specific IgM, are found in ET-bearing sera associated with a large molecular size structure(s). These carbohydrates are also found in ET cell-culture supernatants and cell-free ascites fluid derived from this tumor, indicating their tumor origin. Taken together, our results indicate that lack of specific IgM antibodies in ET-bearing mice is not due to faulty production, but to in vivo absorption by carbohydrates shed from ET cells in increasing amounts as the tumor progresses. Thus, NS cells are unable to suppress this IgM production in vivo, despite the strong suppressor activity they show for many responses in vitro.

Animals↗
PubMed1991

Occurrence of antibodies to protease-treated histones in a patient with vasculitis.

We describe the presence of IgG antibodies reacting with histones previously treated with proteases in a patient with vasculitis. The patient's serum did not react with nontreated histones and when several enzymes were tested separately, only alpha-chymotrypsin reproduced the effect. Reactivity was directed against histone fraction H2B and no other autoantibody was found in the patient's serum. This could represent an autoantigen-driven response, histones hydrolyzed in vivo with proteases being the immunogenic stimulus. Diagnostic and pathogenic implications derived from the existence of such autoantibodies are discussed.

Adult↗
PubMed1991

Occupational asthma caused by Brazil ginseng dust.

The inhalation of different substances of plant origin can cause immediate and late onset asthma. The list of these agents responsible for such reactions is continuously increasing. We discuss a patient who developed symptoms of asthma after exposure to Pfaffia paniculata root powder used in the manufacturing of Brazil ginseng capsules. Airway hyperreactivity was confirmed by a positive bronchial challenge to methacholine. Sensitivity to this dust was confirmed by immediate skin test reactivity, a positive bronchial challenge (immediate response), and the presence of specific IgE detected by ELISA technique to an aqueous extract. The bronchial response was inhibited by sodium cromoglycate. Unexposed subjects did not exhibit reactivity to this ginseng extract with any of the tests referred to above. The same study performed with Korean ginseng (Panax ginseng) elicited negative results. This study is the first, to our knowledge, that links ginseng-root dust to occupational asthma.

Adult↗
PubMed1990

Inhibition of in vivo tumor growth by a monoclonal IgM antibody recognizing tumor cell surface carbohydrates.

We have shown previously that IgM from Ehrlich tumor (ET)-immunized mice, recognizing ET cell surface carbohydrates, protects control mice to a subsequent tumor challenge. The factors involved in such IgM-mediated protection were unknown, since it was independent of complement activation. Here, we have extended these in vivo studies by means of monoclonal IgM antibodies. Two of them (A10 and E1), strongly recognizing ET cells and with specificity to ET cell surface carbohydrates, were selected. The results show that A10 (but not E1 or unrelated IgM antibodies) is able to protect nonimmunized mice against ET growth. Protection by A10 was also seen by reducing 800-fold the initial dose; however, E1 was unsuccessful whatever the dose used. A10-mediated protection was observed in C3-defective mice (cobra venom factor treated) or in C5-deficient DBA/2, but not in silica-treated animals. Endotoxin removal did not affect the protection afforded by A10 while specific IgM depletion prevented any protective effect. In addition, the relationship between natural antibodies of IgM isotype recognizing ET cell surface carbohydrates and mouse strain resistance to this tumor is established. Similarly, this natural resistance seems to be complement independent but macrophage mediated. Therefore, these results indicate that some IgM molecules recognizing cell surface carbohydrates may participate in in vivo tumor suppression by a macrophage-dependent mechanism.

Animals↗
PubMed1990

[Lymphocyte subpopulations in the evolution of brucellosis].

We have sequentially studied for one year CD3+, CD4+, CD8+, CD11b+, and CD20+ lymphocyte subpopulations in 52 brucellosis patients whose diagnosis was confirmed by hemoculture. We observe at diagnosis a decreased percentage of CD4+ lymphocytes with an increase in CD8+ and inverted CD4+/CD8+ ratio, which was greater in patients with an evolution longer than 4 weeks (p less than 0.05) returning to normal very slowly. The percentage of monocytes was also increase at diagnosis (p less than 0.01) and at their second month CD3+ an CD20+ subpopulations did not suffer any changes during the follow up period. Patients were divided into two groups according to whether one or two anti-Brucella IgG peaks were observed in ELISA throughout the evolution. Patients in whom IgG titer decreased uninterruptedly, the inversion of the ratio during the first two months was greater, while those patients who suffered a relapse showed a simultaneous new decrease in CD4/CD8 ratio (p less than 0.05).

Antibodies, Bacterial↗
PubMed1990

Allergic conjunctivitis to chamomile tea.

Eye washing with chamomile tea is a folk remedy used by the general public to treat conjunctivitis and other ocular reactions. Chamomile is also found in many cosmetic products. Some cases of contact dermatitis (but not reactions of type I) were reported following its topical applications. We present seven hay fever patients that suffered from conjunctivitis; two of them also had lid angioedema after eye washing with chamomile tea. All seven patients had positive skin prick tests to the chamomile tea extract, Matricaria chamomilla pollen and Artemisia vulgaris pollen extracts. Positive conjunctival provocations were also observed in all the patients with the chamomile tea extract. In contrast, no symptoms were observed after oral challenges with this infusion. IgE activity against chamomile tea and Matricaria and Artemisia extracts (composite pollens) was detected by ELISA in the seven patients' sera. A cross reactivity among the above extracts was observed by an ELISA inhibition study. In all cases, the IgE activity to chamomile tea could fully be absorbed by Matricaria pollen extract. Skin prick tests and conjunctival provocation tests also performed in 100 hay fever controls revealed a positive immediate skin response to Artemisia in 15 patients, eight of them also to Matricaria pollen and five of them to Chamomile tea as well. Only two of the last patients had a positive conjunctival response. The results were negative in the rest of the controls. We conclude that the chamomile tea eye washing can induce allergic conjunctivitis. Matricaria chamomilla pollens contained in these infusions are the allergens responsible for these reactions.

Administration, Oral↗
PubMed1989

Development of splenic natural suppressor (NS) cells in Ehrlich tumor-bearing mice.

Spleen cells from C57BL/6J mice bearing Ehrlich carcinoma growing as a solid tumor show progressive unresponsiveness to concanavalin A (Con A) and lipopolysaccharide (LPS) mitogens. This is accompanied by striking spleen enlargement with marked hematopoietic activity. Lymphoproliferative assays of normal spleen cells in co-culture with tumor-bearing spleen cells (TBSC) show that: (a) TBSC contain non-specific suppressor cells able to abrogate both Con A and LPS responses, or mixed lymphocyte reaction, of normal spleen cells and (b) suppression by TBSC is MHC-unrestricted, non-prostaglandin-mediated and greatly enhanced by Con A supernatants. Suppressor cells associated with TBSC are large, low-density cells without markers of mature B or T lymphocytes or of the mononuclear phagocyte system. Most appear to be asialo-GM1-negative, as suppression was only partially inhibited by treatment with anti-asialo-GM1 and complement. Since NK activity is lacking in TBSC, our data strongly suggest that these "null" suppressor cells are related to the natural suppressor (NS) cells found described in normal bone-marrow and neonatal spleens, or induced in adult spleens by total lymphoid irradiation, graft-vs.-host disease, or cyclophosphamide treatment.

Animals↗
PubMed1989

DNA-anti-DNA complexes account for part of the antihistone activity found in patients with systemic lupus erythematosus.

We examined the effect of DNase treatment of sera with antihistone activity. In non-systemic lupus erythematosus (SLE) sera, antihistone levels remained unmodified, but a significant decrease was observed in 7 of 11 SLE sera with anti-DNA antibodies. This was accompanied in some by an increase in anti-DNA levels. We therefore considered that DNA-anti-DNA complexes were being detected, as part of the antihistone activity in SLE patients, by binding of the complexes through their DNA to the histones used in the assay. This was confirmed by demonstrating that DNA-anti-DNA complexes formed in vitro, and by studies performed with monoclonal antibodies with affinity to double-stranded DNA and/or histones.

Antibodies↗