Is sensitization to furry animals an independent allergic phenotype in nonoccupationally exposed individuals?

BACKGROUND

Patients sensitized to common pets (cat, dog) frequently display an immunoglobulin (Ig) E-mediated response to allergens from other animals.

OBJECTIVE

To evaluate whether individuals sensitized to common pets might be at higher risk of developing allergic sensitization to other mammalian allergens.

METHODS

The study population comprised 900 consecutive patients (300 individuals sensitized to different allergens including those of cat and dog [group AL, 300 sensitized to allergens other than those derived from cat and dog [group B], and 300 nonsensitized individuals [group C, controls]). All patients underwent a physical examination, an interview (clinical history, pet ownership, possible exposure data), and skin prick test (SPT) with a standard panel of allergens including cat, dog, horse, rabbit, rat, mouse, guinea pig, hamster, and cow.

RESULTS

A significant difference in allergic sensitization to mammalian allergens was observed in groupA compared with group B (respectively, 244 vs. 17). No sensitization was found in group C.

CONCLUSION

Since sensitization to pet allergens increases the risk of developing allergy to other furry animals, we suggest performing SPTs with several mammalian allergens to identify allergic sensitization and thus prevent future exposure in individuals who are highly sensitized and environmentally exposed to common pets.

The risk of bronchospasm in asthmatics undergoing general anaesthesia and/or intravascular administration of radiographic contrast media. physiopatology and clinical/functional evaluation

It is well known that patients suffering from bronchial asthma undergoing to surgical procedures requiring general anaesthesia (GA) or the administration of water soluble radiographic contrast media (RCM) experience a risk of potentially severe bronchospasm. Nevertheless, little attention has been devoted on the possible preventive measures to reduce the occurrence of this potentially life-threatening event. It has been shown that the most important risk factor for bronchospasm during GA induction and/or the use of RCM is represented by a high degree of bronchial hyperreactivity with airway instability not adequately controlled by long-term anti-inflammatory treatment. The aim of this review is to underline the need for an accurate clinical and functional evaluation of asthmatics (especially those with a relevant degree of asthma severity) undergoing GA or administration of RCM. Guidelines shared by pulmonologists, allergologists, anesthesiologists and radiologists should be produced in the future for a better evaluation and management of these patients. General practitioner plays an important role in managing asthmatic patients in "Real Life". It is likely that "Real Life"--optimally controlled asthmatics could undergo GA/RCM with lower risks especially in emergency conditions when it is not possible to perform any preoperative evaluation.

Severe respiratory syndrome induced by allergic mono-sensitization to European hamster (Cricetus cricetus) in a older woman

Although the increase in the rate of hamster ownership, no report of allergic sensitization to common hamster (Cricetus cricetus)-derived allergens as a consequence of domestic exposure has been published in Italy. A 64-year-old woman was referred to our Allergy Centre for the recent onset of conjunctival and severe respiratory symptoms (rhinitis, cough, wheezing and dyspnea). About three months ago she had purchased a common hamster as home pet. Another hamster had lived at patient's home for about four months nine years ago. The results of SPT revealed allergic sensitization to Cricetus cricetus dander only (wheal 6x7 mm, positive control 7x7 mm). Total IgE were 59.3 kU/L. Specific IgE only to Cricetus cricetus epithelia (2.10 kUA/L), were also detected. Spirometry revealed a moderate degree of bronchial obstruction. Some important considerations can be drawn from our report: a) few months of hamster ownership are probably sufficient to induce an allergic sensitization and clinical symptoms, b) older age of sensitization in comparison to other studies, c) rapid remission of clinical symptoms after the removal of hamster d) skin prick tests and/or evaluation of specific IgE for hamster allergens should be performed in all potentially susceptible individuals.

Rabbit allergens: a significant risk for allergic sensitization in subjects without occupational exposure

BACKGROUND

Although rabbits are becoming popular as pets, data about the characteristics of allergic sensitization to rabbit allergens in patients without professional exposure are scarce.

AIMS OF THE STUDY

To determine the characteristics of allergic sensitization to pet rabbits, and the role of direct and indirect exposure to rabbits and rabbit allergens in non-professionally exposed patients.

METHODS

From among 1124 consecutive outpatients, we selected all subjects with an immediate skin reaction to rabbit dander. A clinical history including a careful evaluation of the modality of rabbit exposure, the results of skin-prick tests (SPTs) and total/specific IgE antibodies were recorded. The prevalence of rabbit ownership in the Naples area was also calculated.

RESULTS

Among 753 SPT-positive patients, 20 (2.65%) were sensitized to rabbit dander (5 patients were mono-sensitized). Fifteen patients reported direct rabbit contact (7 were rabbit owners and 8 had occasional contact outside the home); 3 patients had indirect exposure through contact with rabbit owners and 2 patients denied any direct or indirect exposure. Rabbit mono-sensitized owners of pet rabbits had persistent (moderate-severe) symptoms. The prevalence of rabbit ownership is 1.56%.

CONCLUSIONS

In susceptible not professionally exposed individuals, direct rabbit contact and, in some cases, indirect or no apparent exposure, may induce allergic sensitization to rabbit allergens. A progressive increase in rabbit sensitization (also by indirect exposure) may be expected as a consequence of the increase in rabbit ownership.

O-Alkylation of a lignite humic acid by phase-transfer catalysis

A mild phase-transfer catalytic reaction has been conducted to O-alkylate the acidic functions of a lignite humic acid (HA), using tetrabutylammonium hydroxide as the phase-transfer catalyst. The HA acidic functional groups were made to react, in tetrahydrofuran, by nucleophilic substitution with several alkyl halides-methyl iodide, and ethyl, propyl, and butyl, and benzyl bromide. The occurrence of the O-alkylation reaction was assessed by elemental analysis and 1H NMR, CPMAS 13C NMR, and FTIR spectroscopy. Bonding of alkyl groups increased the carbon and hydrogen content and the H/C ratios of all the humic reaction products. Increased nitrogen in the reaction products suggested incomplete removal of the phase-transfer catalyst after purification of the alkylated HA. 1H NMR and CPMAS 13C NMR spectra of alkylated products provided evidence of the successful occurrence of the alkylation reactions. Infrared spectra confirmed the NMR results, revealing the characteristic absorption of newly formed alkyl and aryl ethers and esters in the alkylated products and C-H stretching in the aromatic ring of the benzylated derivative. These findings indicate that humic matter can be successfully alkylated with several different alkylating groups by catalysed phase-transfer reaction. This O-alkylation reaction has the advantage of being mild, versatile, and high-yielding compared with traditional methylation reactions applied to HA. The possibility of introducing different alkyl groups into the HA by a mild phase-transfer reaction may become useful by enabling improved fractionation of humic supramolecular associations and further understanding of the molecular nature of humic substances.

Systemic reactions from skin testing: literature review

The skin prick test (SPT) is the most appropriate diagnostic approach to identify IgE sensitization to aeroallergens, foods, hymenoptera venom and some pharmacological compounds. SPT is considered a safe diagnostic approach, but several fatal or near-fatal reactions have been described. Based on the literature, the occurrence of systemic reactions with inhalant allergens has diminished over the last thirty years, whereas fresh food, hymenoptera venom and antibiotic SPT still carry some risk. In general, the risk of systemic reactions is lower with SPT than with intradermal testing. Some patients (history of previous anaphylactic reactions, small children, pregnant women, uncontrolled asthma, high degree of reactivity) should be considered at higher risk of systemic/anaphylactic reactions. Based on the literature, the risk of fatality due to SPT is extremely remote, and severe/anaphylactic reactions are rare. Nevertheless, this risk cannot be completely excluded, especially in highly susceptible subjects. Physicians who perform SPT should be aware of this and apply simple precautional rules.

Direct and prolonged exposure to dogs does not influence the degree of skin prick test positivity to dog allergen

BACKGROUND

The relationship between pet ownership and the risk of developing allergic sensitization to pet allergens is still controversial. We assessed the possible effect of direct exposure to dog allergen on skin reactivity in dog-sensitized patients.

METHODS

We studied, in a case-control trial, 116 adults sensitized to dog allergens (55 with a dog at home for at least 10 years and 61 without it). The degree of response was assessed by skin prick test, performed in quadruplicate with three concentrations of allergenic extract: A (1:20 w/v), B (1:200 w/v) and C (1:2000 w/v). The mean diameter of each wheal was assessed using a visilog image analysis software.

RESULTS

No significant difference between the two groups in the wheal diameters induced by the three concentrations of dog allergen could be demonstrated.

CONCLUSION

The results of this study suggest that direct dog exposure in adults with respiratory allergy is not associated with greater cutaneous response to dog allergens, as compared to non exposed subjects.

Electrospray ionization mass spectrometry of terrestrial humic substances and their size fractions

Electrospray ionization mass spectrometry (ESI-MS) was used to evaluate the average molecular mass of terrestrial humic substances, such as humic (HA) and fulvic (FA) acids from a soil, and humic acid from a lignite (NDL). Their ESI mass spectra, by direct infusion, gave average molecular masses comparable to those previously obtained for aquatic humic materials. The soil HA and FA were further separated in size-fractions by preparative high performance size exclusion chromatography (HPSEC) and analyzed with ESI-MS by both direct infusion and a further on-line analytical HPSEC. Unexpectedly, their average molecular mass was only slightly less than for the bulk sample and, despite different nominal molecular size, did not substantially vary among size-fractions. The values increased significantly (up to around 1200 Da) after on-line analytical HPSEC for the HA bulk sample, at both pH 8 and 4, and for the HA size-fractions when pH was reduced from 8 to 4. It was noticed that HA size-fractions at pH 8 were separated by on-line HPSEC in further peaks showing average masses which progressively increased with elution volume. Furthermore, when the HA and NDL bulk samples were sequentially ultracentrifuged at increasing rotational speed, their supernatants showed mass values which were larger than bulk samples and increased with rotational speed. These variations in mass values indicate that the electrospray ionization is dependent on the composition of the humic molecular mixtures and increases when their heterogeneity is progressively reduced. It is suggested that the dominance of hydrophobic compounds in humic supramolecular associations may inhibit the electrospray ionization of hydrophilic components. Our results show that ESI-MS is reasonably applicable to humic substances only after an extensive reduction of their chemical complexity.

Potential availability of heavy metals to phytoextraction from contaminated soils induced by exogenous humic substances

Effective phytoremediation of soils contaminated by heavy metals depends on their availability to plant uptake that, in turn, may be influenced by either the existing soil humus or an exogenous humic matter. We amended an organic and a mineral soil with an exogenous humic acid (HA) in order to enhance the soil organic carbon (SOC) content by 1% and 2%. The treated soils were further enriched with heavy metals (Cu, Pb, Cd, Zn, Ni) to a concentration of 0, 10, 20, and 40 microg/g for each metal and allowed to age at room temperature for 1 and 2 months. After each period, they were extracted for readily soluble and exchangeable (2.5% acetic acid), plant-available (DTPA, Diethylentriaminepentaacetic acid), and occluded (1 N HNO(3)) metal species. Addition of HA generally reduced the extractability of the soluble and exchangeable forms of metals. This effect was directly related to the amount of added HA and increased with ageing time. Conversely, the potentially plant-available metals extracted with DTPA were generally larger with increasing additions of exogenous HA solutions. This was attributed to the formation of metal-humic complexes, which ensured a temporary bioavailability of metals and prevented their rapid transformation into insoluble species. Extractions with 1 N HNO(3) further indicated that the added metals were present in complexes with HA. The observed effects appeared to also depend on the amount of native SOC and its structural changes with ageing. The results suggest that soil amendments with exogenous humic matter may accelerate the phytoremediation of heavy metals from contaminated soil, while concomitantly prevent their environmental mobility.

Asthma treatment must be always tailored to the individual patient

Several studies have shown that there are notable benefits in adding a long acting beta 2-agonist to an inhaled corticosteroid. Particularly, long acting beta 2-agonists allow to reduce the amount of steroid that is required to induce a specific response and, consequently, its possible side effects. Currently the pharmaceutical market promotes, and physicians tend in any case to privilege, the use of fixed combinations for the treatment of the asthmatic patient and this also in the first phases of the illness. Nevertheless, for the majority of patients with mild to moderate asthma, it seems more reasonable to optimize the dose of the inhaled steroid before considering the addition of a long-acting beta 2-agonist, and use this latter on an 'as needed' basis if its pharmacodynamic characteristics allow it. Use of combinations is the more reasonable therapeutic choice for patients with a more severe pathological picture, who, despite the optimized dosage of the inhaled glucocorticoid, also require a long acting beta 2-agonist. After having verified the stability of the clinical control, it is possible to continue with the combined therapy provided, however, that this allows the treatment of the patient with the lowest dose of corticosteroid able to prevent, as far as is possible, exacerbations. Asthma exacerbations are less frequent with this therapy, but when they appear it is necessary to be immediately able to increase and, sometimes, also maximize the dosage of corticosteroid without being forced to double, or even triple, the dose of the long acting beta 2-agonist unless there is a real need--and which probably, rather, would induce unwanted side effects.

Elemental quantitation of natural organic matter by CPMAS 13C NMR spectroscopy

Cross-polarized magic-angle-spinning NMR (CPMAS-NMR) techniques are assumed to be only semi-quantitative in the assessment of carbon distribution in humic substances or natural organic matter, due to a number of interferences such as spinning side bands (SSB) in spectra, paramagnetic species in samples, and low or remote protonation of aromatic carbons. Fast rotor spin rates or direct polarization NMR techniques are normally applied to improve quantitative signal detectability. Variable contact time pulse sequences were used here to obtain CPMAS-NMR spectra of organic compounds of known structure and different humic substances. Integration of spectral areas, previously subtracted of SSB, and relative stoichiometric factors were used for mathematical elaboration to calculate the elemental content in samples. These values did not significantly differ from those obtained by direct determination of elemental content with quantitative elemental analysis. Our results showed that the carbon observed CPMAS-NMR provides a quantitative representation of the whole carbon content in humic substances.

Deep venous thrombosis in patients undergoing salvage radical cystectomy

OBJECTIVE

The possible occurrence of venous thrombosis in tumor-bearing patients had already been reported by Trousseau in the past century. The blood clotting alterations in cancer-bearing patients can cause Deep Venous Thrombosis (DVT), especially in those patients with disseminated metastases. Anti-tumor chemotherapy can increase the risk of thrombosis. Herein we report our past experience on a sample of patients who underwent pelvic surgery to treat infiltrating bladder tumors.

METHODS

We have retrospectively analyzed the records of patients with infiltrating bladder tumors who underwent salvage radical cystectomy.

RESULTS

We observed the highest incidence of DVT (33.3%; 3 out of 9) in those patients with a higher risk due to anesthesia and an absolute need for extensive surgery. One of our patients died of pulmonary embolism.

CONCLUSION

The diagnosis of DVT and Pulmonary Embolism is not always easy to achieve and all possible tests must be performed whenever possible (e.g. clinical examination, hematological test, etc.).

Increased retention of polycyclic aromatic hydrocarbons in soils induced by soil treatment with humic substances

The analytical recovery of a mixture of polycyclic aromatic hydrocarbons (PAHs) was determined from a soil before and after oxidation with hydrogen peroxide, and subsequently treated with increasing amounts of an exogenous humic acid and subjected to different incubation periods. The release of PAHs from soil depended on the specific structure and physico-chemical properties of each PAH, and increased with additions of exogenous humic materials for both the oxidized and non-oxidized soil as well as with time of PAH permanence in soil. PAH recoveries were lower in the non-oxidized soil, thereby revealing the importance of native organic matter in increasing PAH retention in soils. This study shows that mobility of PAHs in soils can be controlled by soil conditioning with humic substances.

Combined effects of an oxidative enzyme and dissolved humic substances on 13C-labelled 2,4-D herbicide as revealed by high-resolution 13C NMR spectroscopy

Phenoxyalkanoic acids are a widely used class of herbicides. This work employed high-resolution 13C NMR to study the structural changes induced by humic substances and horseradish perodixase on 2,4-dichlorophenoxyacetic acid (2,4-D) 13C-labelled in the side chain. NMR spectra showed that humic substances chemically catalyze abiotic splitting of [13C]2,4-D into 2,4-dichlorophenol and [13C]acetic acid at pH 7 but not at pH 4.7. Peroxidase did not catalyze the oxidative degradation of [13C]2,4-D at any pH tested and inhibited the effect of humic substances. Catalytic degradation by humic substances was attributed to free-radical reactions enhanced by the stereochemical contribution of large conformational structures formed by heterogeneous humic molecules at neutral pH. Inhibition of 2,4-D degradation when humic substances were combined with peroxidase was explained by modification of both chemical and conformational humic structure due to peroxidase-promoted oxidative cross-coupling among humic molecules. Our findings show for the first time that the abiotic degradation of 2,4-D is catalyzed by dissolved humic substances at neutral pH.

Polymerization of humic substances by an enzyme-catalyzed oxidative coupling

A novel understanding of the structural features of humic substances supports the self-assembly supramolecular association of relatively small molecules rather than their polymeric nature. An increase in the conformational stability of humus may thus be achieved through promotion of intermolecular covalent bondings between heterogeneous humic molecules by an enzyme-catalyzed oxidative reaction. We present evidence from high performance size exclusion chromatography (HPSEC) and diffuse reflectance infrared spectrometry (DRIFT) that oxidation of a humic material catalyzed by horseradish peroxidase stabilizes the humic structure by the formation of aryl and alkyl ethers and permanently enhances its molecular size.