Diet score is associated with plasma homocysteine in a healthy institutionalised elderly population

BACKGROUND AND AIM

Total plasma homocysteine (tHcy) is an independent risk factor for cardiovascular diseases. Among other dietary and non-dietary factors, B vitamins, such as folate, riboflavin and cobalamin, are primary determinants of tHcy in the general population. However, research has concentrated on the relationship of these nutrients with tHcy, and little is known about overall eating patterns and tHcy.

METHODS AND RESULTS

In this study, we analysed whether a diet score based on the consumption of folate-, riboflavin- and cobalamin-rich food groups was associated with tHcy in a sample of 140 institutionalised elderly subjects (59 men and 81 women aged 60-80 years) from Northern Spain. The food groups identified as the major contributors to the intake of the three vitamins were vegetables, fruit, fish, meat and milk and dairy products. The mean tHcy level was 13.3+/-5.1 micromol/L (range: 3.9-30.7 micromol/L). None of the food groups predicted tHcy levels individually, but the overall diet score was inversely associated with tHcy in a multiple linear regression analysis. High tHcy levels (>16 micromol/L) were almost twice as prevalent in the groups scoring less than 7 than in those scoring 7 or more (37.5 vs 19.6%, p=0.021).

CONCLUSIONS

These data suggest that a dietary pattern characterised by high intakes of B vitamin-rich foods is associated with a lower tHcy concentration and a reduced percentage of high tHcy levels in elderly subjects. They also support the use of dietary pattern approaches to evaluate the relationships between diet and health outcomes that go beyond single nutrient analyses.

Expression of CCAAT/enhancer-binding protein-beta (C/EBPβ) and CHOP in the murine growth plate

Our aim was to evaluate the expression of transcription factors CCAAT/enhancer-binding protein-beta (C/EBPβ) and C/EBP-homologous protein (CHOP) in the growth plate. Proximal tibial epiphyseal growth plates from ten 15-day-old Wistar rats were used. Additionally, anti-proliferating cell nuclear antigen (PCNA), anti-5-bromo-2’-deoxyuridine (BrdU) immunostaining, terminal transferase dUTP nick end-labelling (TUNEL) and nucleolar organiser region-associated proteins (AgNOR) techniques were peformed. The histological morphology of the growth plate from C/EBPβknock-out mice was also analysed.

The normal growth plate showed that C/EBPβ and CHOP factors are expressed both in the germinative/ upper proliferative and in the lower proliferative zones. Furthermore, BdrU+ and PCNA+ cells were present exclusively in the germinative and proliferative zones, while TUNEL+ and AgNOR+ cells were seen in all three zones of the growth plate. Acellular areas, hypocellularity, the increase in cell death and anomalies in the architecture of the cell columns were observed in the growth plates of C/EBPβ (−/ −) knockout mice.

We suggest that C/EBPβ and CHOP transcription factors may be key modulators participating in the chondrocyte differentiation process in the growth plate.

Psoriasis vulgaris and psoriatic arthritis share a 100 kb susceptibility region telomeric to HLA-C

OBJECTIVE

To map the locus for susceptibility to psoriasis in patients with psoriatic arthritis.

METHODS

Seventy-four patients with psoriatic arthritis and 95 patients with psoriasis vulgaris were included in this study. Polymorphic genes and microsatellite markers centromeric (C1_2_5) and telomeric (C1_4_4, OTF3, HCR and the corneodesmosin gene) to HLA-C were studied in an association analysis. Typing was also performed on a control population of 104 matched donors.

RESULTS

The allele Cw*0602 was associated both with psoriasis [49 vs 21%, Pc<0.0003; odds ratio (OR)=3.6, aetiological factor (AF)=0.72] and with psoriatic arthritis (62 vs 21%, Pc<0.000001; OR=6.1, AF=0.83). In psoriatic patients a susceptibility region telomeric to HLA-C that includes C1_4_4 (56 vs 22%, Pc<0.0002; OR=4.39, AF=0.77), OTF3 (85 vs 60%, Pc<0.0002; OR=3.7, AF=0.73) and HCR (63 vs 26%, Pc<0.00001; OR=3.8, AF=0.74) was observed. In psoriatic arthritis patients the susceptibility region was delimited by HLA-C and C1_4_4 (384 allele, 56 vs 22%, Pc<0.0002; OR=4.37, AF=0.77).

CONCLUSIONS

Comparing the susceptibility regions associated with the two diseases, an overlapping interval of 100 kb between HLA-C and OTF3, which might contain the psoriasis gene, can be defined.

Chronic administration of losartan reverses cardiovascular changes in hypertensive fructose-fed rats

The cluster of risk factors including hyperinsulinemia, insulin resistance, hypertriglyceridemia and hypertension has been called syndrome X. Several evidences link the insulin resistance syndrome with endothelial dysfunction. Since the participation of the renin-angiotensin system (RAS) in this pathology is still unclear, the present study examined the effect of chronic administration of an angiotensin AT1 receptor antagonist, losartan (L), on endothelial nitric oxide synthase (eNOS) activity in aortic endothelium and cardiac tissue, and on the proliferation of primary cultured aortic smooth muscle cells (SMC), obtained from fructose-fed rats (FFR), an experimental model of syndrome X Male Wistar rats were used: Control, FFR and FFR+L (n = 8 in each group). After 8 weeks, tissue samples were obtained and 10% fetal calf serum (FCS) proliferative effect was examined in SMC by 3H-thymidine incorporation and cell counting. The eNOS activity was estimated in aortic endothelial lining and cardiac homogenates by conversion of 3H-arginine into 3H-citrulline. FFR aortic SMC showed a significantly increased 10% FCS-induced 3H-thymidine incorporation and cell number compared to controls. FFR aortic and cardiac eNOS activities were significantly decreased. Chronic treatment with L decreased systolic blood pressure,reverted cardiac hypertrophy, abolished the increased SMC proliferation and restoredeNOS activity. These data confirm that changes in SMC proliferation and endothelial dysfunction at different levels of the cardiovascular system are involved in syndrome "X", and that AT1 receptor blocking can revert those changes, suggesting an important role of the RAS, possibly mediated by AT2 receptors and kinins, in the physiopathological mechanisms of this model.

Adhesion of probiotic lactobacilli to chick intestinal mucus

In the present work, interactions between three Lactobacillus strains (Lactobacillus fermentum CRL1015, Lactobacillus animalis CRL1014, and Lactobacillus fermentum CRL1016) and chicken small intestinal mucus were determined. Three lactobacilli isolated from chicken and selected by their potentially probiotic properties were able to grow in mucus preparations. Three peaks from gel filtration chromatography of intestinal mucus were obtained. The adhesion to three mucus fractions (I, II, and III), especially fraction III, was higher (P < 0.01) in L. fermentum CRL1015 than L. animalis CRL1014. Pretreatment of this fraction with proteases and metaperiodate showed lower (P < 0.01) adhesion values than that of the control, suggesting that a glycoprotein from the mucus acts as a receptor for L. fermentum CRL1015. Highest adhesion values were obtained at pH 7 and 42 °C, and neither the removal of divalent cations with ethylenediaminetetraacetic acid (EDTA) nor the addition of calcium produced significant variation from the adhesion values of the control (P > 0.01). This adhesion was only inhibited by N-acetyl-glucosamine. Salmonella pullorum and Salmonella gallinarum showed high (P < 0.01) values of adhesion to chick intestinal mucus. The results obtained from assays of the inhibition of adherence of Salmonella spp. to mucus, immobilized in polystyrene tissue culture wells, indicated that the pathogen adhesion was not reduced by lactobacilli (P > 0.05) or their spent culture supernatants (P > 0.05), suggesting that these strains did not interfere with the binding sites for Salmonella spp. adhesion to the small intestinal mucus.Key words: mucus, adhesion, Lactobacillus, probiotic, chicken.

Cloning and characterization of human complement component C7 promoter

To study the transcriptional regulation of the human complement component C7, a 1 kb promoter fragment was cloned and the transcription start site was determined. C7 is expressed by the hepatoma-derived cell line Hep-3B, but not by Hep-G2. Transfection of these cell lines with different C7 promoter-luciferase constructs demonstrated that 1 kb of the 5'-flanking region contains the necessary elements for driving C7 transcription in a tissue-specific manner and showed that the sequence between -29/+102 retained the majority of C7 promoter activity in Hep-3B. Electrophoretic mobility shift assays suggested that the binding of the C/EBPalpha transcription factor to a C/EBP sequence located at +42 is essential for C7 expression. To investigate whether the absence of C/EBPalpha expression in Hep-G2 cells is responsible for the lack of C7 transcription, Hep-G2 cells were transfected with a C/EBPalpha expression vector. C/EBPalpha transactivated the C7 luciferase reported gene and restored the C7 expression in Hep-G2 cells.

[Coaching in the health setting: an approach to its viability]

OBJECTIVE

To analyse the contributions that the participants in a formative activity elaborated respect the viability of the coaching in the health environment.

METHOD

Qualitative study of the contributions of the 18 participants in the workshop upon applications of the coaching in the health environment carried out the month of March 2002 at the Institute of Health Studies (IHS).

RESULTS

The contributions deal with: a) the opportunities: help to healthcare professionals that become to exercise directive responsibilities and strategies to help for the cultural change, and b) the objections: resistance to change, utilization as punishment, results difficult to measure.

CONCLUSIONS

The methodology of the coaching is susceptible of being applied in persons that they should exercise a key paper in a health organization, above all in process of change.

Evaluation of morphology and microcirculation of the pancreas by ex vivo and in vivo reflectance confocal microscopy

BACKGROUND

Near-infrared reflectance confocal microscopy (CM) provides non-invasive real-time images of thin virtual horizontal tissue sections with high resolution and contrast.

AIM

Aim of the study was to characterize morphology, microcirculation and leukocyte-endothelial interaction (LEI) in normal pancreas by in vivo and ex vivo CM.

METHODS

For CM we used water immersion objective lenses of high numerical aperture and near-infrared wavelengths. Experimentally measured lateral optical resolution is 0.5-1 micron and the axial resolution is 3-5 microns. The maximum depth of resolution was 300-400 microns. For ex vivo imaging, freshly excised pancreatic tissue from rats was studied by reflectance CM and conventional histopathology. For in vivo CM, the pancreatic head was exteriorized on a specially constructed stage for imaging the microcirculation and LEI. Images were obtained in real time at rates of 30 frames/s and later analyzed off-line to evaluate LEI and functional capillary density (FCD).

RESULTS

CM allowed high resolution visualization of normal pancreas acinar cells, ducts, islets, capillaries and LEI in postcapillary venules. Histological images and optical sections from ex vivo CM can be correlated. Cellular morphology is better analyzed by conventional histology, but angioarchitecture and connective tissue structure are better evaluated by CM. FCD (265.7 +/- 16.6 cm-1) and LEI (rolling leukocytes 5.3 +/- 1.6/100 microns/sticking leukocytes 1.5 +/- 0.9/100 microns) were evaluated by in vivo CM in the normal pancreas.

CONCLUSIONS

CM findings in tissues ex vivo correlate with those of classical histology but add informative details of connective tissue structure and angioarchitecture. Potential future applications for in vivo CM include real-time analysis of microcirculation, leukocyte-endothelial interaction and angiostructure in inflammatory and malignant pancreatic diseases.

Endocannabinoids and basal ganglia functionality

In recent years, our knowledge on the cannabinoid pharmacology has shown a significant rise in terms of both quantity (more compounds and more targets) and quality (more selective compounds). This allows to consider cannabinoids and related compounds as a promising new line of research for therapeutic treatment of a variety of conditions, such as brain injury, chronic pain, glaucoma, asthma, cancer and AIDS-associated effects and other pathologies. Motor disorders are another promising field for the therapeutic application of cannabinoid-related compounds, since the control of movement is one of the more relevant physiological roles of the endocannabinoid transmission in the brain. There are two pathologies, Parkinson's disease and Huntington's chorea, which are particularly interesting from a clinical point of view due to the direct relationship of endocannabinoids and their receptors with neurons that degenerate in those disorders. However, other neurological pathologies, such as Alzheimer's disease or multiple sclerosis, which are not motor disorders in origin, but present a strong alteration in the control of movement, have also been a subject of interesting research for a cannabinoid therapy. This review will summarize our current knowledge on the role of these endogenous substances in the control of movement and, in particular, on the possible therapeutic usefulness of these compounds in the treatment of motor pathologies.

Examination of adhesive determinants in three species of Lactobacillus isolated from chicken

The microbial adhesion process includes passive forces; electrostatic interactions; hydrophobic, steric forces; lipoteichoic acids; and specific structures, such as external appendages (lectins) and (or) extracellular polymers. In a previous work, we showed that Lactobacillus animalis, L. fermentum, and L. fermentum ssp. cellobiosus had lectinlike proteic structures on their surfaces and high hydrophobicity values on the cell surface of L. fermentum ssp. cellobiosus. Here, we examined the presence of the bacterial forces or structures that could be involved in the interaction between bacteria and epithelial cells. Lactobacillus animalis and L. fermentum possessed a net negative surface charge, whereas L. fermentum ssp. cellobiosus showed similar affinity to both cationic and anionic exchange resins, aggregated in the presence of ammonium sulfate, and had high affinity (75.4%) to a hydrophobic matrix. Only L. animalis was shown to have ribitol teichoic acids in the cell wall. The amount of polysaccharides from cell walls varied between different strains, with L. fermentum ssp. cellobiosus having the highest concentration. Lectin extracts obtained from lactobacilli did not possess sugar residues, thereby demonstrating the proteic nature of the superficial surface structures of three strains. The lactic acid bacteria studied here showed different surface determinants, which could be involved in the interactions between these lactobacilli and intestinal epithelial cells.

Design, synthesis and biological evaluation of novel arachidonic acid derivatives as highly potent and selective endocannabinoid transporter inhibitors

In the present work, we have designed and synthesized a series of arachidonic acid derivatives of general structure I which have been characterized as highly potent and selective inhibitors of anandamide transporter (IC(50) = 24-0.8 microM, K(i) > 1000-5000 nM for CB(1) and CB(2) cannabinoid receptors and vanilloid VR(1) receptor). Among them, N-(3-furylmethyl)eicosa-5,8,11,14-tetraenamide deserves special attention as being the most potent endocannabinoid transporter inhibitor (IC(50) = 0.8 microM) described to date.

Relationship between soil copper content and copper content of selected crop plants in central Chile

A survey of copper levels in agricultural soils of central Chile revealed two soil clusters-one with a mean copper level of 162 mg/kg and one with a mean copper level of 751 mg/kg of soil. Samples of soils from both soil clusters were characterized on the basis of physicochemical characteristics, and copper extractability was compared by saturation and CaCl2 extraction as well as an acid-leaching procedure (TCLP). We also measured the copper content of various tissues of tomato (Lycopersicon esculentum) and onion (Allium cepa) crops growing on these soils. Other than copper levels, soils from the two clusters were quite similar, with slightly greater levels of molybdenum and cadmium in the high-copper soils. Within each cluster, extracted copper levels and total soil copper levels were not correlated. However, the three extraction procedures solubilized significantly more copper from the high-Cu soils. Mineralogical characterization of the soil particles and depth profiles of soil metal levels in a subsample of sites suggested that highly insoluble copper ore and mining wastes might account for the high copper levels. Neither total nor extractable copper levels allowed statistical prediction of the levels of copper in plant tissue. The edible tissues of both crops had the same mean copper content, regardless of the copper soil level. However, copper contents of stems and leaves were significantly higher for plants growing on the high-Cu soils. These results show that in these soils, high copper levels are associated with very insoluble copper species and thus low bioavailability of copper to crop plants.

[Pediatric lung resection. A case series and evaluation of postoperative lung function]

The most common causes of pulmonary lobectomy in children are congenital lung malformations (CLM) and bronchiectasias. Our aim was to present the causes and clinical course and lung function of lobectomized patients. Between 1990 and July 1999 27 lobectomies were performed on patients whose ages ranged from newborn to 14 years. Lobectomies were performed to correct CLM in 124 cases and for acquired pulmonary disease (APD) in 13. Among CLM cases, half (n = 7) had cystic adenomatoid malformation. Among the APD patients, 10 had bronchiectasias, with etiological confirmation in 6 cases (3 secondary to serious adenovirus infection). Mean hospital stay was 4.6 days among those who experienced no postoperative complications. Symptoms resolved after surgery for most symptomatic patients. Lung function tests could be carried out with 8 patients over 6 years old whose operations had taken place 7 to 78 months earlier (x = 35 months) and whose age at the time of surgery was a mean 7 years 6 months (range 60 to 144 months). Spirometry showed normal forced vital capacity for 7 of 8 patients (87 to 143% of theoretical value). Arterial oxygen saturation measured during and after a 6-minute walking test was normal for 7 of 8 patients. Chest films showed reduced lung volume on the affected side in 5 of 8 patients. In summary, lobectomy is a procedure with few complications. It requires a short hospital stay and has good postoperative prognosis. Function and x-ray studies show adequate lung growth and development, with normal lung function in those who could be so examined because they were old enough to cooperate.

Aortic smooth muscle cell proliferation and endothelial nitric oxide synthase activity in fructose-fed rats

The aim of this study was to evaluate the proliferative behavior of vascular smooth muscle cells in primary culture (pC-SMC) and the endothelial nitric oxide synthase (eNOS) activity in the endothelial lining of the aorta of fructose-fed rats (FFR). This is an experimental model of syndrome X, a cluster of cardiovascular risk factors including hyperinsulinemia, insulin resistance, and hypertension that has been suggested to be of pathophysiologic importance for the development of atherosclerosis. Male Wistar rats were used: Control (n = 12) and FFR (n = 12). After receiving fructose in drinking water (10% w/v) during 8 weeks, biochemical parameters, systolic blood pressure (SBP) and relative heart weight (RHW) were determined. The proliferative effect of 10% fetal calf serum (FCS) was examined in aortic pC-SMC by [3H]thymidine incorporation and by cell counting. Ca2+/calmodulin-dependent NOS activity was estimated in aortic endothelial lining and in heart tissue homogenates by conversion of [3H]arginine into [3H]citrulline. Fructose-fed rats showed hyperinsulinemia (P = .0263), altered glucose tolerance test (P < .001), higher SBP (P < .0001), and RHW (P = .0145), compared to control rats. These animals also showed an increase of 10% FCS-induced [3H]thymidine incorporation (P < .0001) and cell number of aortic pC-SMC (P = .0049) and decreased eNOS activity in both aortic endothelium (P = .0147) and cardiac tissue (P < .0001). These data support the hypothesis that syndrome X is associated to changes in SMC proliferation and endothelial dysfunction, which could be involved in the onset or progression of the atherogenic process.

Confocal examination of nonmelanoma cancers in thick skin excisions to potentially guide mohs micrographic surgery without frozen histopathology

Precise removal of nonmelanoma cancers with minimum damage to the surrounding normal skin is guided by the histopathologic examination of each excision during Mohs micrographic surgery. The preparation of frozen histopathology sections typically requires 20-45 min per excision. Real-time confocal reflectance microscopy offers an imaging method potentially to avoid frozen histopathology and prepare noninvasive (optical) sections within 5 min. Skin excisions ( approximately 1 mm thick) from Mohs surgeries were washed with 5% acetic acid and imaged with a confocal cross-polarized microscope. The confocal images were compared with the corresponding histopathology. Acetic acid causes compaction of chromatin that increases light back-scatter and makes the nuclei bright and easily detectable. Crossed-polarization strongly enhances the contrast of the nuclei because the compacted chromatin depolarizes the illumination light whereas the surrounding cytoplasm and normal dermis does not. Fast low-resolution examination of cancer lobules in wide fields of view followed by high-resolution inspection of nuclear morphology in small fields of view is possible; this is similar to the procedure for examining histopathology sections. Both the Mohs surgeon and the patient will potentially save several hours per day in the operating room. Fast confocal reflectance microscopic examination of excisions (of any thickness) may improve the management of surgical pathology and guide microsurgery of any human tissue.

Safety and preliminary immunogenicity of the recombinant outer membrane protein P64k of Neisseria meningitidis in human volunteers

P64k is a meningococcal protein from Neisseria meningitidis that has been obtained by recombinant DNA technology. Recombinant P64k has been extensively characterized by physicochemical and immunological methods. Lately this protein has been found to act as a versatile immunological carrier for weak antigens in mice. In the present work, a Phase I clinical trial was carried out in healthy volunteers who received three inoculations of either placebo or recombinant P64k (20 or 50 microg). No severe adverse events occurred during the trial. Only mild adverse events in ten volunteers were observed. At 1 month after the third dose, 15 out of 18 volunteers (83.3%) who received the recombinant antigen had a P64k-specific antibody titre > or =1:100, as detected by ELISA. A fourth dose, given 9 months after the third one, elicited a potent booster immune response in P64k vaccinees. Accordingly, these P64k formulations were considered safe and immunogenic in healthy human volunteers.

Glucocorticoid effects on Fos immunoreactivity and NADPH-diaphorase histochemical staining following spinal cord injury

Glucocorticoids (GC) provide neuroprotection and early recovery after spinal cord injury (SCI). While several mechanisms were proposed to account for these effects, limited information exists regarding GC actions in sensory areas of the spinal cord. Presently, we studied the time course of Fos expression, and reduced nicotinamide adenine dinucleotide phosphate-diaphorase (NADPH-d) histochemical staining to monitor neuronal responses to SCI with or without GC treatment. Rats with sham-operation or transection at the thoracic level (T7-T8) received vehicle or 5 mg/kg of the GC dexamethasone (DEX) at 5 min post-lesion and were sacrificed 2 or 4 h after surgery. Another group of SCI rats received vehicle or intensive DEX treatment (5 min, 6 h, 18 h and 46 h post-lesion) and were sacrificed 48 h after surgery. The number of NADPH-d positive neurons or Fos immunoreactive nuclei was studied by computer-assisted image analysis in superficial dorsal horn (Laminae I-III) and central canal area (Lamina X) below the lesion. While constitutive Fos immunoreactive nuclei were sparse in controls, SCI increased Fos expression at 2 and 4 h after injury. DEX treatment significantly enhanced the number of Fos positive nuclei in Laminae I-III by 4 h after transection, although the response was not maintained by intensive steroid treatment when tested at 48 h after SCI. NADPH-d positive neurons in Laminae I-III increased at 2 and 4 h after SCI while a delayed increased was found in central canal area (Lamina X). DEX treatment decreased NADPH-d positive neurons to sham-operated levels at all time points examined. Thus, while GC stimulation of Fos suggests activation of neurons involved in sympathetic outflow and/or pain, down-regulation of NADPH-d indicates attenuation of nociceptive outflow, considering the role of enzyme-derived nitric oxide in pain-related mechanisms. Differential hormonal effects on these molecules agree with their localization in different cell populations.

Genetic variability, molecular evolution, and geographic diversity of HLA-B27

HLA-B27 represents a family of 23 closely related alleles (B*2701-23) that differ at 24 amino acid positions. The pattern of polymorphisms of B27 was studied, with special reference to synonymous (Ks) and nonsynonymous (Ka) divergence among alleles. B27 alleles are characterized by the enhanced rate of nonsynonymous nucleotide substitution in the peptide-binding region (PBR). The percentage of substitutions between each of the B27 pairs ranges from 0.2%-3% in exons 2-3 to 1.8%-20.1% in the PBR. A phylogenetic analysis of all B27 alleles is described in order to identify subtypes with a common evolutionary history. These results, together with the phylogenetic trees obtained from the comparison between exons 2-3 and PBR indicate that polymorphism of B27 is selectively maintained. Most of the differences are clustered in the C/F pocket affecting the specific binding of antigenic peptides. Gene conversion and point mutation are the most important mechanisms responsible for B27 diversification. The interaction of selection, genetic drift, and recombination events is important for generating polymorphism at B27 alleles. We analyzed a large extended B27 positive population from different parts of the world. Our results indicate that B27 subtypes differ in their ethnic distribution, which may be the result of different genetic and geographical origins. Different factors such as genetic drift, bottleneck effect, and admixture among populations could contribute to the genetic constitution of B27. The striking correlation between the structural features of B27 and the ethnic distribution of these subtypes suggests a model of strong directional evolution, in which the subtypes could have arisen from B*2705.

Rapid allergen delivery with photomechanical waves for inducing allergic skin reactions in the hairless guinea pig animal model

BACKGROUND

Patch testing is the confirmatory procedure for allergic contact dermatitis. The test requires the application of chemicals under occlusion for approximately 48 hours to maximize penetration, although it can also produce irritation. Photomechanical waves (PW) have been shown to render the stratum corneum transiently permeable and facilitate the delivery of macromolecules into the epidermis. This alternative might reduce prolonged occlusion of the skin to minimize irritancy, while retaining the sensitivity of the test.

OBJECTIVE

PW was used to facilitate the delivery of an allergen into the skin in vivo.

METHODS

The allergic skin reaction using PW delivery was compared with 5-minute and 21-hour occlusion in a sensitized hairless albino guinea pig model. The pigs were sensitized by intradermal injection of (0.01%) dinitrochlorobenzene (DNCB) and topical administration (0.1%, 1 week later) of the hapten. One month later, testing for the allergic response was performed by the administration with PW of 10 microL of 0.1% DNCB.

RESULTS

Our results show that there was an allergic reaction for the 24 hour occlusion or PW delivery of the antigen. In contrast, no response was observed for the 5-minute occlusion with the antigen.

CONCLUSION

The rapid delivery of antigens with PW can improve the test for the diagnosis of contact dermatitis.