Structure-function coupling increases during interictal spikes in temporal lobe epilepsy: A graph signal processing study.

OBJECTIVE: Structure-function coupling remains largely unknown in brain disorders. We studied this coupling during interictal epileptic discharges (IEDs), using graph signal processing in temporal lobe epilepsy (TLE). METHODS: We decomposed IEDs of 17 patients on spatial maps, i.e. network harmonics, extracted from a structural connectome. Harmonics were split in smooth maps (long-range interactions reflecting integration) and coarse maps (short-range interactions reflecting segregation) and were used to reconstruct the part of the signal coupled (Xc) and decoupled (Xd) from the structure, respectively. We analysed how Xc and Xd embed the IED energy over time, at global and regional level. RESULTS: For Xc, the energy was smaller than for Xd before the IED onset (p < .001), but became larger around the first IED peak (p < .05, cluster 2, C2). Locally, the ipsilateral mesial regions were significantly coupled to the structure over the whole epoch. The ipsilateral hippocampus increased its coupling during C2 (p < .01). CONCLUSIONS: At whole-brain level, segregation gives way to integrative processes during the IED. Locally, brain regions commonly involved in the TLE epileptogenic network increase their reliance on long-range couplings during IED (C2). SIGNIFICANCE: In TLE, integration mechanisms prevail during the IED and are localized in the ipsilateral mesial temporal regions.

Time-varying effective EEG source connectivity: the optimization of model parameters.

Adaptive estimation methods based on general Kalman filter are powerful tools to investigate brain networks dynamics given the non-stationary nature of neural signals. These methods rely on two parameters, the model order p and adaptation constant c, which determine the resolution and smoothness of the time-varying multivariate autoregressive estimates. A sub-optimal filtering may present consistent biases in the frequency domain and temporal distortions, leading to fallacious interpretations. Thus, the performance of these methods heavily depends on the accurate choice of these two parameters in the filter design. In this work, we sought to define an objective criterion for the optimal choice of these parameters. Since residual- and information-based criteria are not guaranteed to reach an absolute minimum, we propose to study the partial derivatives of these functions to guide the choice of p and c. To validate the performance of our method, we used a dataset of human visual evoked potentials during face perception where the generation and propagation of information in the brain is well understood and a set of simulated data where the ground truth is available.

Viabilidad y eficacia de una estrategia multidimensional para fomentar la actividad física en pacientes con ictus agudo / Feasibility and efficacy of a multidimensional strategy to promote physical activity in acute stroke patients

Objetivo: Describir la viabilidad, la seguridad y la eficacia de un enfoque multidimensional para fomentar la actividad física precoz después de un ictus isquémico. Materiales y métodos: Estudio de casos y controles que compara los resultados en los pacientes ingresados en la unidad de ictus antes y después de establecer un protocolo de fomento de la actividad física mediante la incorporación de un ejercicio aeróbico usando un cicloergómetro, y la facilitación de información verbal y escrita sobre los beneficios de la actividad física. La medida principal del estudio fue la actividad física realizada a los 3 meses usando el International Physical Activity Questionnaire. Resultados: Incluimos 93 pacientes (60 controles y 33 en el grupo activo). La actividad física previa al ictus era baja. Las 126 sesiones de cicloergómetro se toleraron bien. A los 3 meses del ictus, la actividad física fue mayor (693 vs. 462 MET-min/semana; p=0,039) y el tiempo de sedestación, menor (2.100 vs. 2.520min; p=0,009) en el grupo activo. Conclusiones: A pesar de un conocimiento apropiado de los beneficios del ejercicio sobre la salud, la actividad física es baja después del ictus. Un enfoque multidisciplinar, combinando ejercicio precoz e información individualizada, puede incrementarla

Objective: To describe the feasibility, safety, and efficacy of a multidimensional approach to promote physical activity soon after ischaemic stroke. Materials and methods: Case-control study comparing the outcomes in consecutive patients admitted to a stroke unit before and after implementing a physical activity promotion protocol by performing aerobic exercise using a cycle ergometer, and informing them on the benefits of physical activity. The primary outcome measurement was physical activity at 3 months using the International Physical Activity Questionnaire. Results: A total of 93 patients were included (60 controls and 33 in the active group). Pre-stroke activity was low. A total of 126 cycle ergometer sessions were well tolerated. At 3 months, post-stroke physical activity was greater (693 vs. 462 MET-min/week; P=.039) and sedentary time shorter (2,100 vs. 2,520min; P=.009) in the active group. Conclusions: Despite proper knowledge of the health benefits of exercise, physical activity is low after stroke. A multidisciplinary approach combining early exercise and individualised information on its benefits may increase physical activity after stroke

[Housing and health counselling services in the management of allergic respiratory disease]. / Le Conseil Habitat-Santé dans la prise en charge des maladies allergiques respiratoires.

INTRODUCTION: Input from Housing and health counselling services is advisable when a patient's health seems to be impaired by their housing conditions. METHODS: 650 home visits have been performed by our organisation since 2002. Each visit includes a questionnaire to assess respiratory as well as non-respiratory indoor risk factors, Acarex test to assess mite-allergen content in mattress dust, mould sampling and, when appropriate, air sampling for measurement of volatile organic compounds and aldehydes. RESULTS: The dwellings studied were mostly flats located in the downtown and occupied by a tenant. In most instances, several health hazards were identified. These hazards, in decreasing occurrence included: mold (74.4%), mite infestation in mattress dust (56.3%), cleaning products accessible to children's'hands (47.8%), dangerous electrical circuits (21.1%), exposure to chemical air pollutants (9.0%), exposure to an electromagnetic field (2.8%). Numerous fungal species were identified often occurring in association. CONCLUSION: This service allowed the identification of numerous and various health hazards. Its efficacy and effectiveness remains to be evaluated.

Mycotoxin identification in moldy dwellings.

The objective of this study was to assess the level of macrocyclic trichothecenes (MCT), one of the most potent mycotoxins, on wall surfaces, floor dust and air samples from moldy dwellings. The study was based on an index group comprising 15 flooded dwellings contaminated by Stachybotrys chartarum or Chaetomium and a control group comprising nine dwellings without molds on visual inspection and mold sampling. Three samples were collected from each dwelling: a sample from the moldy wall, using a swab, a floor dust sample on a 0.5 m(2) surface with a cloth and an air sample using a pump comprising a 1 microm Teflon filter. The MCT level was measured using a monoclonal, antibody-based ELISA test. Compared with measurements performed in index dwellings, higher MCT values were measured on floor dust samples from moldy dwellings (P = 0.02). Samples from wall surfaces demonstrated nearly significant differences (P = 0.06). No significant differences were observed for air samples (P = 0.15), but some samples showed increased MCT levels. Significant correlations were observed between the levels measured on wall surfaces, floor dust and air samples (P = 0.02 to 0.05). In contrast, no correlation was observed between moldy surface and MCT levels. In conclusion, this paper reports for the first time direct evidence for the presence of MCT in moldy dwellings.

Rapid human skin permeation and topical anaesthetic activity of a new amethocaine microemulsion.

We developed a fast-acting, topical, 4% (w/w) amethocaine microemulsion and tested its in vitro permeation in isolated human skin. Comparison with a commercial amethocaine gel (Ametop((R)) ) was performed using Franz diffusion cells. Permeability coefficient (k(p)), flux (J) and percentage permeation after 10 h of microemulsion application were, in all cases, 1.5 times higher than those of the gel. The values obtained for the P(1) parameter [1], 1.06.10(-2) cm (microemulsion) and 0.724.10(-2) cm (gel) indicate that the microemulsion excipients favour amethocaine deposition in the skin, increasing the permeability coefficient, amount of drug retained in the skin, and the flux achieved. Analgesic activity was also examined in rats made hyperalgesic or allodynic after carrageenan-induced inflammation. The rats were distributed into four groups (n = 5-9 per group), each group receiving topically either amethocaine microemulsion, amethocaine gel (Ametop), amethocaine subcutaneous infiltration or nothing (controls). In edematous paws, anti-hyperalgesic activity appeared at 4.2 and 13.8 min after application of amethocaine microemulsion and gel, respectively. These effects are lower than after 0.5% w/w amethocaine infiltration. Amethocaine microemulsion was the only topical formulation with an anti-allodynic effect, although this effect was less than with amethocaine infiltration. These results suggest that microemulsion could be a valuable formula for improving amethocaine permeation and thus bringing rapid pain relief.

[Paratesticular rhabdomyosarcoma]. / Rabdomiosarcoma paratesticular.

Contribution of one case of paratesticular rhabdomyosarcoma in a 10-years old male patient. Following radical orchiectomy it was classified as Group Ia (Intergroup Rhabdomyosarcoma Study). Treatment was completed with 9 polychemotherapy courses of Ifosfamide, Vincristine and Actinomicine D. The patient was disease-free 6 months after the treatment.

Rapid skin anesthesia using a new topical amethocaine formulation: a preclinical study.

UNLABELLED: We developed a fast-acting topical amethocaine emulsion and tested its analgesic activity against heat or mechanically induced pain in a rat paw model. The first experiment was performed in rats made hyperalgesic or allodynic after carrageenan-induced inflammation. Rats were distributed in five subgroups, each receiving topically one of the following: amethocaine microemulsion, amethocaine gel (Ametopgel), EMLA (Eutectic Mixture of Local Anesthetics) cream, amethocaine infiltration, or nothing (controls). The second experiment was conducted on healthy, selected heat- or touch-hypersensitive rats, which were distributed as in the first experiment. Paw withdrawal time from a heat and a mechanical stimulus was used as a pain index. In the first experiment, antihyperalgesic activity appeared at 4.2, 13.8, and 14 min after amethocaine microemulsion, gel, or EMLA cream, respectively. Amethocaine microemulsion was the only topical formulation with an antiallodynic effects, although less than with amethocaine infiltration. In healthy rats (second experiment), all topical formulations produced similar analgesic effects in heat-induced pain of the ipsilateral paw. Activity in the contralateral paw appeared earlier with amethocaine microemulsion, which was also the only one that increased touch-induced withdrawal time in the ipsi- and contralateral paws. Therefore, the microemulsion could be valuable for improving amethocaine skin penetration and thus bringing rapid pain relief. IMPLICATIONS: Topical anesthetics are used in several painful clinical procedures, but they tend to have a slow onset time. A new amethocaine microemulsion with a faster onset of analgesia than commercial formulations was developed and its activity tested in pain states induced by heat or mechanical stimulus in inflamed and healthy rat paws.

Rabdomiosarcoma paratesticular / Paratesticular rhabdomyosarcoma

Presentamos un caso de rabdomiosarcoma paratesticular en un niño de 10 años. Tras practicar orquiectomía inguinal radical fue clasificado como estadio Ia según el IRS (Intergroup Rhabdomyosarcoma Study). El tratamiento se completó con quimioterapia adyuvante (9 ciclos de Ifosfamida, Vincristina y Actinomicina D) y el paciente permanece libre de enfermedad 6 meses después del tratamiento (AU)

Contribution of one case of paratesticular rhabdomyosarcoma in a 10-years old male patient. Following radical orchiectomy it was classified as Group Ia (Intergroup Rhabdomyosarcoma Study). Treatment was completed with 9 polychemotherapy courses of Ifosfamide, Vincristine and Actynomicine D. The patient was disease-free 6 months after the treatment (AU)

Changes in prostaglandin E2 (PGE2) levels in paw exudate, stomach and kidney of arthritic rats: effects of flosulide.

To further examine the organ-specific toxic effects of selective and non-selective COX-2 inhibitors in adjuvant arthritis (CAA), we assessed the PGE2 concentration in various organs. AA was induced by intradermal injection of Mycobacterium butyricum. Fourteen days after inoculation, AA rats were selected and treated orally every day for two weeks with the selective COX-2 inhibitor, flosulide, or the COX-1-COX-2 inhibitor, indomethacin. The time-course of paw swelling was determined. At the end of treatments, PGE2 was extracted from paw, stomach (wall and mucosa) and kidney and its concentration was determined by ELISA. Paw edema increase was accompanied by a rise in PGE2 concentration. PGE2 also increased in stomach (mucosa and wall) and kidney. The anti-inflammatory treatment with flosulide (5 mg/kg x day), and indomethacin (1 mg/kg x day), reduced plantar edema by 98.0% and 74.4% respectively. Both drugs greatly decreased PGE2 levels in paw (73.7-53.2%), stomach wall (84.5-80.3%), stomach mucosa (109.9-110.9%) and kidney (92.9-97.5% respectively). However, PGE2 reductions in AA rats did not fall significantly below control values.

Acute effects of the anti-inflammatory cyclooxygenase-2 selective inhibitor, flosulide, on renal plasma flow and glomerular filtration rate in rats.

Nephrotoxicity of nonsteroidal anti-inflammatory drugs is associated with other risk factors (volume-depletion) and may be secondary to functional changes mediated by the inhibition of renal cyclooxygenases. Acute anti-inflammatory doses of flosulide and indomethacin were determined on carrageenan paw edema and its effects on renal plasma flow (RPF) and glomerular filtration rate (GFR) were studied in normovolemic and hypovolemic rats. In normovolemic rats, flosulide increased RPF and GFR (25 mg/kg) and indomethacin (5-10 mg/kg) was without effect. Volume-depleted rats were obtained by oral furosemide (32 mg/kg), urinary eicosanoids were determined. After furosemide, plasma volume, RPF and GFR and PGE2 decreased. Treatment of hypovolemic rats with flosulide (5-25 mg/kg) or indomethacin 10 mg/kg reduced RPF and GFR. Flosulide at 5 mg/kg reduced 6-keto-PGF1alpha whereas at 25 mg/kg and after indomethacin at 10 mg/kg a fall in 6-keto-PGF1alpha and TXB2 appeared. Our data suggest that acute COX-2 selective inhibition may alter renal function.

Effect of the COX-2 selective inhibitor l-745,337 on inflammation and organ prostaglandin E2 (PGE2) levels in adjuvant arthritic rats.

The anti-inflammatory activity of the cyclooxygenase-2 inhibitor, L-745,337, was assessed in adjuvant arthritic rats (AA). The relationship between PGE2 organ levels and drug activity or adverse effects was determined. Arthritic rats were orally treated for two weeks with L-745,337 (0.1, 1 and 5 mg/kg/day), indomethacin (1 mg/kg/day) or vehicle and paw swelling was determined. At the end of the study, samples from paw, stomach (wall and mucosa) and kidney were obtained from rats with or without treatment at high doses of L-745,337 or indomethacin and PGE2 levels were determined. The L-745,337 anti-inflammatory effective-dose-50 was 0.4 mg/kg. Maximal anti-inflammation was obtained with L-745,337 or indomethacin at doses of 5 and 1 mg/kg respectively. L-745,337 showed anti-arthritic activity. No stomach ulcers appeared in either untreated or treated arthritic and healthy control rats. In AA rats, PGE2 increased in paw, stomach wall, gastric mucosa and kidney. These levels were lower in all organs after both drugs but not below PGE2 control levels.

Selective cyclooxygenase-2 (COX-2) inhibitors reduce anti-Mycobacterium antibodies in adjuvant arthritic rats.

Adjuvant arthritis, induced by Mycobacterium butyricum, is an experimental immunopathy that shares many features of human rheumatoid arthritis and, as such, is one of the most widely used models for studying the anti-inflammatory activity of compounds. In rats with adjuvant induced arthritis, IgG antibodies to M. butyricum have been detected and autoantigens that cross react with mycobacteria may be involved in the pathogenesis of adjuvant arthritis. In this study, the anti-inflammatory and immunosuppressive activities of two cyclooxygenase-2 selective inhibitors, flosulide and L-745,337, at doses of 0.1, 1 and 5 mg/kg/day, were examined in adjuvant arthritic rats. After 14 days of treatment, a clear dose-dependent inhibition of plantar edema was seen for both flosulide (ID50 lower than 0.1 mg/kg) and L-745,337 (ID50 = 0.4 mg/kg). Plasma levels of IgG anti-M. butyricum antibodies were also decreased by both drugs. In each case the maximal immunosuppressive effect was observed at doses lower than 5 mg/kg. The non-selective COX-2 inhibitor, indomethacin (1 mg/kg) decreased paw edema by 65% and the levels of IgG anti-M. butyricum by 45%. Neither cyclooxygenase selective inhibitors nor indomethacin decreased the delayed hypersensitivity reaction induced by M. butyricum. Thus, in vivo inhibition of COX-2 inhibited articular swelling and also the humoral immune response to Mycobacterium.

Simultaneous technetium-99 MAG(3), iodine-131-orthoiodohippurate and iodine-125 iothalamate clearance and biodistribution after bolus injection in rats.

A bolus injection multiple blood sampling method was developed for the simultaneous measurement of blood and plasma clearance of three radiopharmaceuticals in rats. Technetium-99m mercaptoacetyltriglycine ([(99m)Tc]MAG(3)) and iodine-131-orthoiodohippurate ([(131)I]OIH) were used as makers of effective renal blood flow (ERBF), and iodine-125 iothalamate ([(125)I]IOT) was used as a marker of glomerular filtration rate (GFR). These methods can be easily performed in rats without arterial catheterization. Tissue biodistribution was studied in four groups of rats subjected to the following: group A, renal pedicle isolation (sham-operated); group B, ligature of one kidney pedicle; group C, ligature of both renal pedicles; and group D, ligature of both kidney pedicles and the bile duct. Renal clearance of [(99m)Tc]MAG(3) was greater than [(131)I]OIH and both agents were cleared faster than ([(125)I]-IOT). Either of the two markers of ERBF may be used in experimental studies, but it should be borne in mind that these are relative measurements of kidney performance. [(99m)Tc]MAG(3) and [(125)I]-IOT showed bile excretion in healthy rats, so they cannot completely fulfill the requirements for use as markers of ERBF. When renal function was impaired experimentally, [(99m)Tc]MAG(3) and [(125)I]-IOT were excreted in bile and [(131)I]OIH was secreted in the intestine. Thus, while the markers of ERBF and GFR may be reliable under normal physiological conditions, they may give progressively more erroneous values as renal function deteriorates.

Arachidonic acid (AA) and tetradecanoylphorbol acetate (TPA) exert systemic effects when applied topically in the mouse.

We studied the systemic actions of topically applied arachidonic acid (AA) and tetradecanoylphorbol acetate (TPA) in the mouse. AA or TPA-induced ear edema, increases in vascular permeability, eicosanoid levels, neutrophil and mononuclear influx were determined in both phlogogen-treated and contralateral vehicle-treated ear of each mouse and were compared with vehicle-treated ears from control mice. Edema and vascular permeability increases appeared only in AA- or TPA-applied ears. Moreover, in contralateral ears from AA-treated mice an increase in 6-keto-PGF1 alpha and LTB4 was found. Only LTB4 increased in the contralateral ear after TPA. Contralateral ears from AA- or TPA-treated mice also showed a significant increase in MPO levels. The increased levels of 6-keto-PGF1 alpha but not those of LTB4 in contralateral ears were reduced by indomethacin applied simultaneously with the phlogogen. AA also increased plasma and serum levels of LTB4, but not those of 6-keto-PGF1 alpha. In contrast, TPA increased plasma and serum levels of 6-keto-PGF1 alpha and LTB4. The results show that both AA and TPA applied topically exert systemic effects.

Effect of topically applied cyclooxygenase-2-selective inhibitors on arachidonic acid- and tetradecanoylphorbol acetate-induced dermal inflammation in the mouse.

The topical effects of cyclooxygenase-2 (COX-2)-selective inhibitors, flosulide (CGP 28238), L-745,337 and SC-57,666 were examined in AA- and TPA-induced ear dermal inflammation in the mouse. The doses that caused 50% inhibition in AA edema (ED50) were 2.4, 0.45 and 0.35 mg/ear for flosulide, L-745,337 and SC-57,666, respectively. The respective ED50s in TPA-edema were 1, 0.45 and 0.14. Indomethacin and zileuton showed higher activity than the COX-2-selective inhibitors in both models. Flosulide and L-745,337 inhibited the AA-induced increase in 6-keto-PGF1 alpha, while SC-57,666 was inactive, 80% inhibition was seen with indomethacin while zileuton had no effect. COX-2-selective inhibitors and indomethacin had no effect on LTB4 levels, while zileuton produced a 50% inhibition. The TPA-induced increase in 6-keto-PGF1 alpha was greatly inhibited by all COX-2 inhibitors while LTB4 was potentiated by both flosulide and L-745,337. Indomethacin inhibited 6-keto-PGF1 alpha and zileuton reduced 6-keto-PGF alpha and strongly reduced LTB4. The neutrophil influx induced by AA was lower than that of TPA. Myeloperoxidase (MPO) levels were lowered by flosulide and L-745,337 but not by SC-57,666. TPA-induced MPO increase was decreased by all COX-2 inhibitors. Indomethacin and zileuton had similar effect on AA and TPA-induced increase in MPO. The results indicate that COX-2-selective inhibitors showed lower topical anti-inflammatory activity than indomethacin or zileuton.

Effect of topically applied cyclosporin A on arachidonic acid (AA)- and tetradecanoylphorbol acetate (TPA)-induced dermal inflammation in mouse ear.

Topical cyclosporin A (CsA) was compared with dexamethasone, indomethacin and phenidone in edema, increases in vascular permeability, eicosanoids and cell-influx induced by arachidonic acid (AA) and tetradecanoylphorbol acetate (TPA) in mouse ears. CsA ED(50) on AA-edema (7.7 micrograms/ear) was similar to dexamethasone and lower than indomethacin and phenidone. CsA ED(50) in TPA edema (21 micrograms/ear) was higher than dexamethasone and lower than indomethacin or phenidone. All drugs equally reduce the AA-induced increase in vascular permeability, but CsA and dexamethasone had more activity on TPA. AA-increase in vascular 6-keto-PGF1 alpha was reduced by dexamethasone, indomethacin and phenidone but not by CsA; only phenidone reduced LTB4. TPA-increase in 6-keto-PGF1 alpha was reduced by CsA and indomethacin while CsA, dexamethasone and phenidone decreased LTB4. CsA, indomethacin and phenidone, but not dexamethasone, suppressed AA-neutrophil influx. In TPA-ears all drugs produced similar reduction in neutrophil influx. CsA was shown to be a good topical anti-inflammatory drug.

Normal-pressure hydrocephalus: evaluation with cerebrospinal fluid flow measurements at MR imaging.

PURPOSE: To evaluate magnetic resonance (MR) imaging-based quantitative phase-contrast cerebrospinal fluid (CSF) velocity imaging for prediction of successful shunting in patients with normal-pressure hydrocephalus (NPH). MATERIALS AND METHODS: Eighteen patients (mean age, 73 years) with NPH underwent routine MR imaging and CSF velocity MR imaging before ventriculoperitoneal (VP) shunting. The calculated CSF stroke volume and the aqueductal CSF flow void score were compared with the surgical results. RESULTS: All 12 patients with CSF stroke volumes greater than 42 microL responded favorably to CSF shunting. Of the six patients with stroke volumes of 42 microL or less, three improved with shunting while three did not. The relationship between CSF stroke volume greater than 42 microL and favorable response to VP shunting was statistically significant (P < .05). There was no statistically significant relationship between aqueductal CSF flow void score and responsiveness to shunting. CONCLUSION: CSF velocity MR imaging is useful in the selection of patients with NPH to undergo shunt formation.

Characterization of allergoids from ovalbumin in vitro and in vivo.

Several in vivo and in vitro methods for monitoring immunological properties of two allergoids obtained by formaldehyde treatment of ovalbumin (OA) were developed. The calculated molecular weight of allergoids was 80 kD (OA-F1) and 165 kD (OA-F2), respectively. The allergenic activity in vitro of allergoids in mast-cell histamine release assay was 1000 times lower than of OA. Both allergoids showed reduced ability to induce passive cutaneous anaphylaxis in the Sprague-Dawley rats or systemic anaphylaxis in Dunkin-Harley guinea-pigs. The ability of OA and allergoids to bind to the OA-specific IgE antibodies was measured in vivo by the inhibition of passive cutaneous anaphylaxis (PCA-inhibition). Allergoid binding to IgE was 51-66% lower than the native allergen. Moreover, the avidity of OA-specific IgG antibodies, measured by ELISA-inhibition, for allergoids and allergen was of the same order. Allergoids induced a different pattern of humoral immune response from that, induced by the native allergen. Thus, after immunization of BALB/c mouse, both allergoids induced a higher production of IgG and a lower production of IgE than OA, only OA-F2 induced a lower production of IgG1. The differences in the IgA response to the immunogens was not significant. Delayed hypersensitivity studies in the BALB/c mouse showed that allergoids were 5- to 12-times less effective in inducing a cell-mediated immune response than OA. The present study provides a battery of immunological methods for preclinical testing of modified allergens.

Effects of cyclosporine and dexamethasone on IgE antibody response in mice, and on passive cutaneous anaphylaxis in the rat.

The suppressive effects of cyclosporine A (CsA) and dexamethasone (Dxt) on antigen-specific IgE responses to ovalbumin (OA) were studied in BALB/c mice. The effects upon other isotypes were also analyzed. The antiovalbumin IgE response did not change when low doses of CsA [8 mg/kg intraperitoneally (i.p.)] were administered; IgA also remained unchanged, while IgG and IgG1 decreased significantly. At higher CsA doses (16 mg/kg i.p. or orally), a decrease was noted for all the ispotypes assayed. Dxt administered orally at 0.3 mg/kg selectively inhibited IgE and IgA but did not influence IgG or IgG1 levels. Delayed hypersensitivity reactions to OA were not modified by CsA, but were depressed by Dxt. Although CsA had not effect on passive cutaneous anaphylaxis in the rat, Dxt significantly reduced this reaction when it was administered 6 h before challenge. These results suggest that Dxt has more specific antiallergic activity than CsA.