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Biomedical subjects

A Ballester

Publications and source records attributed to A Ballester.

At least 37 records · Page 2Linked to original sources
PubMed1999

A cost benefit analysis of routine varicella vaccination in Spain.

The objective of the study was to assess varicella epidemiology and the cost of disease in Spain, in order to perform a cost benefit analysis of universal vaccination at 15 months of age. Epidemiological data were obtained from a survey of 150 children with varicella, from hospitalizations and from the Spanish literature. A Markov decision tree was designed with two alternatives, vaccination or nonvaccination. Direct costs derived from the disease were lower than the cost of vaccination (ratio 0.54:1), however when indirect costs, such as working time loss were taken into account, vaccination was the best alternative, with a saving of P(T)2627 per vaccinated subject (P(T)1.6 recovered per peseta invested in the program). Sensitivity analysis shows that decreasing vaccine coverage and efficacy to 0.7, increasing the annual discount rate to 20% and with a vaccine price less than P(T)6000, vaccination is always the best alternative. In conclusion, from the economic point of view, a universal varicella vaccination program in children at 15 months of age would be justified in Spain.

Adult↗
PubMed1999

Biosorption of copper and zinc by Cymodocea nodosa.

The adsorption of the two metal ions Cu and Zn in a single-component system by Cymodocea nodosa, a brown alga, under different pH conditions was investigated. The solution pH significantly affected the exhibited uptake, being maximum at a pH value of 4.5. Multi-component mixture biosorption in aqueous solutions is also reported. A comparison was made between the single-component saturation uptake and the multi-component uptakes. To evaluate the two-metal sorption system performance, simple isotherm curves had to be replaced by three-dimensional sorption isotherm surfaces. In order to describe the isotherm surfaces mathematically, three Langmuir-type models were evaluated. The isotherms indicate a competitive uptake with Cu being preferentially adsorbed. In addition, different tests were carried out to compare the process efficiency working continuously in small columns.

Adsorption↗
PubMed1998

Cot kinase activates tumor necrosis factor-alpha gene expression in a cyclosporin A-resistant manner.

Cot kinase is a protein serine/threonine kinase, classified as a mitogen-activated protein kinase kinase kinase, implicated in T lymphocyte activation. Here we show that an increase in Cot kinase expression promotes tumor necrosis factor-alpha (TNF-alpha) production in Jurkat T cells stimulated by soluble anti-CD3 or by low concentrations of phorbol 12,13-dibutyrate (PDBu) and calcium ionophore. Overexpression of Cot kinase in Jurkat cells activates TNF-alpha gene expression. Cot kinase promotes TNF-alpha promoter activation to a similar extent as calcium ionophore and PDBu or soluble anti-CD28 and PDBu. Neither phorbol esters nor calcium ionophore can replace Cot kinase on TNF-alpha promoter-driven transcription. Expression of a dominant negative form of Cot kinase inhibits TNF-alpha promoter activation induced by stimulation with either calcium ionophore and PDBu, soluble anti-CD28 and PDBu, or soluble anti-CD3 and PDBu. TNF-alpha promoter-driven transcription by Cot kinase is partially mediated by MAPK/ERK kinase and is cyclosporin A-resistant. Cot kinase increases at least the AP-1 and AP-2 response elements. These data indicate that Cot kinase plays a critical role in TNF-alpha production.

8-Bromo Cyclic Adenosine Monophosphate↗
PubMed1998

Adverse events after polysaccharide meningococcal A&C vaccine.

The incidence of adverse events due to meningococcal polysaccharide A&C vaccine was studied in 312 subjects 18 months to 20 y of age who were part of a mass vaccination program. Fever > 38 degrees C occurred in 5.1% (95% CI: 3.1-8.4%). Injection site pain was reported in 78.8% (95% CI: 74.3-83.4%), was severe in 7.4% (95% CI: 4.7-10.9%) and was most frequent in the oldest age group.

Adolescent↗
PubMed1998

Intraoperative assessment of cerebral ischaemia during carotid surgery.

BACKGROUND: This study aimed to evaluate the reliability of somatosensory evoked potentials (SEPs) in identifying clamping ischaemia during carotid surgery under general anaesthesia. METHODS: We reviewed the records of 196 consecutive carotid endarterectomies (CEA) performed under general anaesthesia, out of 1550 patients operated on between 1975 and 1993. SEPs were monitored after contralateral median nerve stimulation at the wrist in all patients. Moreover they received an intravenous bolus of 2500 IU of heparin and the stump pressure was measured. A completion angiography was performed in all patients. An intraluminal shunt was inserted when the amplitude of the N20-P25 SEPs complex decreased by more than 50% of pre-clamping value (pathologic SEPs) or when a preoperative CT-scan showed an ischaemic area in the contralateral hemisphere. In some patients the shunt was not inserted because of technical difficulties or because the pathological SEP complex decrease developed when the suture of the arteriotomy was almost complete. RESULTS AND CONCLUSIONS: As the preclamping amplitude (Ab) of N20-P25 was extremely variable, ranging from 0.9 and 7.5 microV, we adopted the ratio: deltaA=(At-Ab)/Ab (At=amplitude measured during clamping every 2 min at time t). Mean decrease of deltaA measured in the whole group ranged between 15% and 20%, but mean deltaA values in patients with pathological SEPs were around 60%. Even patients with positive CT-scans or with a back-pressure lower than 50 mmHg developed a mean deltaA decrease of about 20%. A pathological SEP was present in 50 patients, but developed in only 12 during the clamping trial. An intraluminal shunt was inserted in 22 cases; the other patients received pharmacological treatment with anaesthetic or vasoactive drugs. Among the patients with pathological SEPs, 3 presented postoperative symptoms related to carotid cross-clamping; only 1 of these was shunted but without SEPs normalisation. No patients with normal SEPs developed a postoperative neurological deficit, giving a reliability of 86.7%, a sensitivity of 100% and a specificity of 86.5%.

Aged↗
PubMed1997

Cot kinase regulation of IL-2 production in Jurkat T cells.

tpl-2 is a rat gene that encodes a serine/threonine protein kinase that can act as a novel mitogen-activated protein (MAP) kinase kinase kinase. Tpl-2 is activated in Moloney murine leukemia virus-induced rat T lymphomas, due to a truncation in the C-terminal region of the protein. cot is a very closely related gene, if not the human homologue. The truncated form of Cot has been shown to have a higher transforming activity than the nontruncated form. In this paper we show that an increase in truncated Cot kinase expression correlates with an increase in IL-2 production in anti-CD3-treated Jurkat cells. Truncated Cot expression also cooperates with PHA or phorbol 12,13-dibutyrate (PDBu) and calcium ionophore for IL-2 production in Jurkat cells. Both the truncated and nontruncated Cot forms increased IL-2 transcription because they enhanced transcription of a reporter gene linked to the IL-2 promoter. The expression of a dominant negative form of Cot inhibits transcription directed by the IL-2 promoter in Jurkat cells stimulated by PDBu and ionophore. These data suggest a role of Tpl-2/Cot kinase in IL-2 production during T lymphocyte activation and could also explain its role in Moloney murine leukemia virus-induced lymphomagenesis.

CD3 Complex↗
PubMed1996

Differentiation of U-937 promonocytic cells with mitomycin C or cis-diamminedichloroplatinum II.

Administration of 0.3 microM mitomycin C (MMC) or 2.0 microM cis-diamminedichloroplatinum II (CDDP) decreased the growth activity and induced the differentiation of U-937 human promonocytic cells, as shown by nitroblue tetrazolium reduction and an increase in surface expression of the leukocyte integrins CD11b/CD18 and CD11c/CD18. Expression of these differentiation markers started to be significant at 48 hr of treatment. These concentrations resulted in little cell damage (determined by Trypan blue exclusion) and slightly induced apoptosis (determined by DNA degradation and changes in nuclear morphology). The treatments induced a transient increase in c-fos and c-jun mRNA levels, with maximum values at 1-6 hr; a transient increase in collagenase mRNA level, with a maximum value at 48 hr; and a progressive increase in vimentin and lamin A and C mRNA levels. These changes were qualitatively similar to those produced by 12-0-tetradecanoylphorbol 13-acetate. CDDP and MMC also caused a transient increase of total AP-1 binding activity, as determined by gel retardation assays. The drugs produced an early transient activation (3-6 hr) of membrane-bound protein kinase C, followed by a later activation (48 hr) of both the membrane and the cytosolic enzyme. These results suggest that protein kinase C and AP-1-dependent gene expression could be involved in myeloid cell differentiation by alkylating agents.

Antibiotics, Antineoplastic↗
PubMed1996

Requirements for in vitro rooting of Quercus robur and Q. rubra shoots derived from mature trees.

Stabilized shoot cultures initiated from crown material of six adult Quercus robur L. trees and from basal epicormic shoots of a Quercus rubra L. tree showed good in vitro rooting capacity. An initial five-day dark period generally improved the rooting response but was detrimental to plantlet quality. There were clonal differences in rooting capacity. The concentration and exposure time of the indolebutyric acid (IBA) treatment were critical for root induction. In both species, best rooting efficiency was achieved by culture in medium containing 25 mg l(-1) IBA for 24 h and subsequent transfer to an auxin-free medium containing 1% activated charcoal. For all clones tested, the charcoal benefited both shoot quality and root system development, the latter being enhanced by the formation of many lateral roots. Total root system area and length, measured with a digital image analyzer, were significantly greater in medium containing charcoal than in medium lacking charcoal. Because darkening the basal part of the shoots with aluminum foil during the rooting phase only caused a small increase in rooting, we conclude that the large effect of charcoal on rooting was the result of adsorption of inhibitory compounds from the medium or the explant or both, rather than of basal darkening. Other factors affecting the rooting response of Q. robur were: (a) the position on the tree of the material from which cultures were initiated (the topophysical effect); and (b) shoot quality. Recycling the same horizontally placed explant on multiplication medium allowed three successive crops of shoots to be obtained, and rootability was typically maintained from crop to crop.

Journal Article↗
PubMed1994

Late occlusion of aortofemoral bypass graft: surgical treatment.

Surgical treatment for graft thrombosis is often difficult and its outcome is complicated by a high incidence of rethrombosis. The records of 803 patients (1261 limbs) treated with aortofemoral bypass graft for peripheral vascular disease were reviewed. Among these, 71 patients (63 men and eight women with a mean age of 60.2 years) needed an overall number of 125 reoperations. The mean follow-up was 6.3 years. Smoking was significantly higher in these patients compared with those who were not reoperated on. Intimal hyperplasia was the most common lesion responsible for graft thrombosis. Before 'redo' surgery 20 patients with recent thrombosis received thrombolytic treatment; one was subsequently treated with percutaneous transluminal angioplasty and the others underwent reoperation. The best patency rates were achieved with reconstruction of the distal anastomosis with a graft interposition or with a patch angioplasty. Isolated thrombectomy was complicated by early rethrombosis in 53.3% of cases. The overall amputation rate was 14%, the operative mortality rate 5.6%, and the incidence of complications 16.8%. At follow-up a cumulative secondary patency rate of 81.7% at 5 years (74.5% at 10 years), a limb salvage rate of 80.5%, and a survival rate of 89.2% at 10 years were recorded. It is concluded that the only indications for redo surgery following graft thrombosis are severe limb ischaemia or disabling claudication.

Adult↗
PubMed1993

In vitro shoot proliferation determined by explant orientation of juvenile and mature Quercus rubra L.

Shoot cultures of Quercus rubra (L.) were established from both juvenile and adult plant material. Initial explants from epicormic shoots formed on the basal zone of the trunks had a greater capacity for in vitro establishment than explants from crown branches. The growth of vigorous axillary shoots was obtained by culturing decapitated shoots horizontally on Woody Plant Medium supplemented with 0.2 mg l(-1) of 6-benzylaminopurine. After 3 weeks of culture the shoots were transferred to fresh medium for two more weeks, giving a 5-week multiplication cycle. Efficient shoot production was achieved by combining three treatments favoring the growth of lateral buds: excision of the apex, horizontal culture and cytokinin treatment. The addition of indoleacetic acid or indolebutyric acid to the multiplication medium did not improve shoot proliferation rates, and naphthaleneacetic acid was detrimental. Recycling the same explant for several successive subcultures improved the efficiency of the propagation procedure. Using the optimal multiplication procedures, nine clones (six of juvenile origin and three from adult trees) were tested in vitro and it was found that genotype and age affected performance.

Journal Article↗
PubMed1990

Characterization of B cell growth in systemic lupus erythematosus. Effects of recombinant 12-kDa B cell growth factor, interleukin 4 and transforming growth factor-beta.

B cells from systemic lupus erythematosus (SLE) patients have been shown to be hyperactive as measured by proliferation and immunoglobulin production. We find that B cells from 6 of 13 SLE patients, in the absence of prior activation, respond two to three times better to recombinant 12-kDa B cell growth factor (BCGF) than do normal or rheumatoid arthritis B cells (p less than 0.005). B cells from normally responsive SLE patients require an anti-mu antibody activation step to generate similar proliferative signal in response to r12-kDa-BCGF. There are no clinical or serological parameters that distinguish these hyperresponsive SLE patients from the normally responsive SLE patients. The combination of r12-kDa-BCGF and interleukin 4 (IL4) gives an enhanced response with both normal and SLE B cells. Transforming growth factor type beta (TGF-beta) suppresses the response to r12-kDa-BCGF in a dose-dependent fashion using B cells from both healthy donors and SLE patients. We conclude that peripheral blood B cells are in an activated state (as detected by response to 12-kDa-BCGF) in approximately 50% of SLE patients. These B cells respond normally to regulation by IL4 and TGF-beta. A therapeutic approach aimed at reducing the B cell hyperactivity in SLE would involve suppressing the effects of 12-kDa-BCGF and IL4 while at the same time enhancing the effects of TGF-beta.

Adolescent↗
PubMed1990

A conserved idiotype and antibodies to retroviral proteins in systemic lupus erythematosus.

22 of 61 systemic lupus erythematosus (SLE) patients produced antibodies to the p24 gag protein of HIV-1 demonstrated by Western blotting. 20 of these 22 patients (91%) also express the 4B4 idiotype (Id 4B4) previously identified on a human anti-Sm monoclonal antibody called 4B4. This represents an enrichment for this Id (seen in only 52% of SLE patients generally). Eight of these 22 SLE patients also have anti-Sm antibody activity. Sm partially inhibits the antibody binding of p24 gag suggesting immunologic cross-reactivity between the retroviral antigen p24 gag and the autoantigen Sm. Anti-Id 4B4 also inhibits p24 gag antibody binding by as much as 40%. Finally the monoclonal antibody 4B4 showed cross-reactivity to Sm and p24 gag. The following points emerge from our studies: (a) SLE patients make antibodies to p24 gag of HIV-1, (b) there is a relationship between immunity to p24 gag and a conserved idiotype, and (c) anti-Sm antibodies can cross-react with p24 gag.

Autoantigens↗
PubMed1989

The expression and function of CD3 and CD5 in patients with primary Sjögren's syndrome.

We studied the expression and function of 2 cell surface markers that induce T cell activation, CD3 and CD5, in 19 patients with primary Sjögren's syndrome (SS). The expression of CD3+ lymphocytes was normal, but CD3 function was moderately reduced, as measured by anti-CD3-induced T cell proliferation. Anti-CD3-induced stimulation of T cell help for Ig production and non-major histocompatibility complex-restricted (natural) killing were normal. In contrast, there was reduced expression and function of the CD5 molecule on peripheral blood lymphocytes of the SS patients. The ratio of CD5+ to CD3+ lymphocytes was 0.45 in SS patients compared with 0.85 in normal subjects, indicating that the CD3+ cells are relatively CD5-deficient in SS patients. Anti-CD5 monoclonal antibody did not augment suboptimal anti-CD3 stimulation of whole peripheral blood lymphocytes or of purified T lymphocytes from SS patients, which indicated impaired functioning of the CD5 molecule. A significant impairment in proliferation was found in response to phorbol myristate acetate and to ionomycin in combination, suggesting defective intracellular signaling. Findings from serial studies of individual patients suggested that normal or low expression of CD5 on T cells can be stable over periods as long as 2 years. However, in 2 patients who required systemic therapy, a correction of the CD5 lymphocyte abnormality occurred in association with clinical remission, which suggests the potential reversibility of this condition. Our findings suggest a possible defect in intracellular signaling in primary SS, related in part to the CD5 molecule, which may provide a molecular explanation for the T cell hyporesponsiveness that is characteristic of this disease.

Antigens, Differentiation↗
PubMed1989

Epitope specificity of anti-La antibodies from patients with Sjögren's syndrome.

To investigate patterns of autoreactivity in Sjögren's syndrome, the epitope specificity of anti-La antibodies was determined using recombinant antigens bearing sequences of the amino, middle, and carboxyl portions of the La molecule. Sera from patients with primary as well as secondary Sjögren's syndrome reacted with all three fragments, although the magnitude of the responses varied markedly among individuals. Furthermore, the proportion of antibody binding directed to the different La epitopes showed considerable individual variations, but these patterns were not correlated with specific clinical manifestations. These results suggest that quantitative and qualitative aspects of anti-La responses in Sjögren's syndrome are determined by factors distinct from those determining the clinical expression of disease.

Antibodies↗
PubMed1989

Increased polyamines may downregulate interleukin 2 production in rheumatoid arthritis.

Polyamines downregulate immune reactivity. RA is associated with decreased IL 2 production. In this study, we present evidence to suggest that excessive polyamines can contribute to the IL 2 deficiency in RA. Blocking polyamine production with inhibitors of ornithine decarboxylase results in increased IL 2 production by RA PBMC. Moreover, polyamine oxidase (PAO) inhibitors and catalase also increase IL 2 production by RA PBMC. This effect of PAO inhibition is monocyte mediated. After 3 d in culture, RA PBMC produce three times more IL 2 than do normal PBMC. This rise is prevented by exogenous spermidine but only in the presence of monocytes. The concentration of polyamines in RA PBMC and synovial fluid MNC is 2-20-fold higher than in normal cells. Thus, polyamines and their oxidation products downregulate IL 2 production by RA PBMC and may account for the decreased T cell effector function seen in this disease.

Adult↗
PubMed1988

Factors affecting in vitro propagation of Quercus robur L.

Explants from five clones of Quercus robur (three of juvenile origin and two from adult trees) were cultured on Gresshoff and Doy medium supplemented with 0.2 mg l(-1) 6-benzylaminopurine. Shoot proliferation from apical and nodal segments was influenced by both clone and type of explant. To increase the efficiency of the propagation procedure, donor shoots (20-25 mm in length and with 2 mm removed from the tip) were recultured at 4-week intervals, and the newly formed shoots harvested before each transfer. Under this regime, the multiplication coefficient (proportion of explants forming axillary shoots multiplied by the mean number of new 8-mm stem segments per explant) was greatest for the second crop and declined sharply by the fourth or fifth crop, in three of the four clones tested. Successive additions of fresh liquid medium to old cultures was much less effective than transfer to fresh medium in promoting axillary shoot production. Elongation of shoots before rooting was increased significantly (P < 0.05) in one of two clones tested by transfer to a medium containing either 0.1 or 1.0 mg l(-1) of zeatin. Addition of fresh liquid medium containing zeatin to old cultures failed to improve shoot elongation or axillary shoot production. However, treatment for 15 days with liquid medium containing 0.1 or 1.0 mg l(-1) indol-3-yl-acetic acid increased subsequent rooting.

Journal Article↗