Reacciones cutáneas a tratamientos farmacológicos y cosméticos / Cutaneous reactions to pharmacologic and cosmetic treatments

En la actualidad, una de las causas más frecuentes de biopsia en la patología cutánea no tumoral son las reacciones cutáneas a fármacos o cosméticos. Además, la continua aparición de nuevos tratamientos farmacológicos y cosméticos obliga a estar preparado para reconocer sus posibles efectos adversos en la piel. Éstos pueden manifestarse en forma de prácticamente todas los patrones histopatológicos e incluso desencadenando la aparición de una dermatosis en individuos propensos a ésta. El diagnóstico de las toxicodermias se basa, como en la gran mayoría de enfermedades dermatológicas, en la correlación clínico-patológica. No obstante, existen unos hallazgos microscópicos que nos pueden sugerir esta posibilidad diagnóstica como por ejemplo la eosinofilia, la disqueratosis y la asociación de patrones histopatológicos inhabituales o aparentemente incongruentes

At the present time, one of the leading causes of biopsy among non-tumoral dermatological diseases is skin reaction to cosmetics or drugs. Due to the continuous advent of new pharmacological treatments and the appearance of novel cosmetic procedures, pathologists must be prepared to recognize their cutaneous adverse reactions. These reactions can adopt practically every histopathological pattern and even trigger the appearance of a dermatosis in a predisposed individual. As in most other dermatological diseases, the diagnosis of cutaneous adverse drug reactions is based on clinico-pathological correlation. Nevertheless, there are some histopathological clues that can suggest this diagnosis such as the presence of eosinophilia and/or dyskeratosis and the combination of unusual and apparently incongruent histopathological patterns

Reacciones cutáneas a tratamientos farmacológicos y cosméticos / Cutaneous reactions to pharmacologic and cosmetic treatments

En la actualidad, una de las causas más frecuentes de biopsia en la patología cutánea no tumoral son las reacciones cutáneas a fármacos o cosméticos. Además, la continua aparición de nuevos tratamientos farmacológicos y cosméticos obliga a estar preparado para reconocer sus posibles efectos adversos en la piel. Éstos pueden manifestarse en forma de prácticamente todas los patrones histopatológicos e incluso desencadenando la aparición de una dermatosis en individuos propensos a ésta. El diagnóstico de las toxicodermias se basa, como en la gran mayoría de enfermedades dermatológicas, en la correlación clínico-patológica. No obstante, existen unos hallazgos microscópicos que nos pueden sugerir esta posibilidad diagnóstica como por ejemplo la eosinofilia, la disqueratosis y la asociación de patrones histopatológicos inhabituales o aparentemente incongruentes

At the present time, one of the leading causes of biopsy among non-tumoral dermatological diseases is skin reaction to cosmetics or drugs. Due to the continuous advent of new pharmacological treatments and the appearance of novel cosmetic procedures, pathologists must be prepared to recognize their cutaneous adverse reactions. These reactions can adopt practically every histopathological pattern and even trigger the appearance of a dermatosis in a predisposed individual. As in most other dermatological diseases, the diagnosis of cutaneous adverse drug reactions is based on clinico-pathological correlation. Nevertheless, there are some histopathological clues that can suggest this diagnosis such as the presence of eosinophilia and/or dyskeratosis and the combination of unusual and apparently incongruent histopathological patterns

Proteome analysis of brown spider venom: identification of loxnecrogin isoforms in Loxosceles gaucho venom.

Brown spiders of the Loxosceles genus are distributed worldwide. In Brazil, eight species are found in Southern states, where the envenomation by Loxosceles venom (loxoscelism) is a health problem. The mechanism of the dermonecrotic action of Loxosceles venom is not totally understood. Two isoforms of dermonecrotic toxins (loxnecrogins) from L. gaucho venom have been previously purified, and showed sequence similarities to sphingomyelinase. Herein we employed a proteomic approach to obtain a global view of the venom proteome, with a particular interest in the loxnecrogin isoforms' pattern. Proteomic two-dimensional gel electrophoresis maps for L. gaucho, L. intermedia, and L. laeta venoms showed a major protein region (30-35 kDa, pI 3-10), where at least eight loxnecrogin isoforms could be separated and identified. Their characterization used a combined approach composed of Edman chemical sequencing, matrix-assisted laser desorption/ionization-time of flight mass spectrometry, and electrospray ionization-quadropole-time of flight tandem mass spectrometry leading to the identification of sphingomyelinases D. The venom was also pre-fractionated by gel filtration on a Superose 12 fast protein liqiud chromatography column, followed by capillary liquid chromatography-mass spectrometry. Eleven possible loxnecrogin isoforms around 30-32 kDa were detected. The identification of dermonecrotic toxin isoforms in L. gaucho venom is an important step towards understanding the physiopathology of the envenomation, leading to improvements in the immunotherapy of loxoscelism.

Purification and characterization of loxnecrogin, a dermonecrotic toxin from Loxosceles gaucho brown spider venom.

The most common manifestation of Loxosceles spider envenoming is a dermonecrotic lesion at the bite site. Dermonecrotic toxins from Loxosceles gaucho venom were purified and characterized by mass spectrometry (capillary liquid chromatography followed by mass spectrometry detection). Two components were purified: a major one of 31,444 Da, called loxnecrogin A, and a minor one of 31,626 Da, called loxnecrogin B, being probably two isoforms of the toxin. The N-terminal sequence of loxnecrogin A showed similarity with N termini of other sphingomyelinolytic dermonecrotic toxins isolated from venoms of different Loxosceles species. The internal sequences did not present any statistically significant hits in sequence databases searches. However, loxnecrogin A partial sequence showed high similarity to regions of L. intermedia LiD1 recombinant protein sequence, recently described in the literature but not yet deposited in databanks.

A synthesis of the phenolic lipid, 3-[(Z)-pentadec-8-enyl] catechol, (15:1)-urushiol.

A synthesis of (15:1)-urushiol, urushiol monoene, 3-[(Z)-pentadec-8-enyl] catechol, 1,2-dihydroxy-3-[(Z)-pentadec-8-enyl] benzene, one of the toxic principles of Rhus toxicodendron and of Rhus vernicifera is described. 6-Chlorohexan-1-ol protected at the OH group with ethyl vinyl ether reacted with 2,3-dimethoxybenzaldehyde in the presence of lithium to give, after removal of the protective group with methanolic 4-toluenesulphonic acid, 1-(2,3-dimethoxyphenyl) heptane-1,7-diol. Catalytic hydrogenolysis in ethanol with palladium-carbon selectively afforded 7-(2,3-dimethoxyphenyl)heptane-1-ol accompanied by a small proportion of the 7-(3-methoxyphenyl)heptane-1-diol, formed by demethoxylation. Reaction of the dimethoxy compound with boron tribromide resulted in both bromination and demethylation to give 7-(2,3-dihydroxyphenyl) heptylbromide. This bromide in tetrahydrofuran (THF) containing hexamethylphosphoric triamide reacted with excess lithium oct-1-yne to give 3-(pentadec-8-enyl)catechol which, by catalytic hydrogenation in ethyl acetate containing quinoline, selectively formed the required cis product, 3-[(Z)-pentadec-8-enyl]catechol which was identical chromatographically and spectroscopically with urushiol monoene separated from the natural product.

Staphylococcal scalded skin syndrome in a healthy adult.

We report a case of staphylococcal scalded skin syndrome (SSSS) in a 65-year-old healthy woman. Fever, purulent conjunctivitis, and exfoliation of the skin in the gluteal region were noted. A scarlatiniform rash was observed on the body, and this erythema was followed by generalized desquamation. Staphylococcus aureus was isolated from her eye discharge, posterior nasopharynx, and the erosive surface of the skin. All the investigated strains produced exfoliative toxin B, but none produced toxic shock toxin-1 (TSST-1) or enterotoxin. The patient was treated with antibiotics and fluid supplementation, resulting in subsidence. This case is thought to have been caused by an abortive form of SSSS or a scarlatiniform variant, which is very rare in healthy adults.

Isolation of dermatoxin from frog skin, an antibacterial peptide encoded by a novel member of the dermaseptin genes family.

A 32-residue peptide, named dermatoxin, has been extracted from the skin of a single specimen of the tree frog Phyllomedusa bicolor, and purified to homogeneity using a four-step protocol. Mass spectral analysis and sequencing of the purified peptide, as well as chemical synthesis and cDNA analysis were consistent with the structure: SLGSFLKGVGTTLASVGKVVSDQF GKLLQAGQ. This peptide proved to be bactericidal towards mollicutes (wall-less eubacteria) and Gram-positive eubacteria, and also, though to a lesser extent, towards Gram-negative eubacteria. Measurement of the bacterial membrane potential revealed that the plasma membrane is the primary target of dermatoxin. Observation of bacterial cells using reflected light fluorescence microscopy after DNA-staining was consistent with a mechanism of cell killing based upon the alteration of membrane permeability rather than membrane solubilization, very likely by forming ion-conducting channels through the plasma membrane. CD spectroscopy and secondary structure predictions indicated that dermatoxin assumes an amphipathic alpha-helical conformation in low polarity media which mimic the lipophilicity of the membrane of target microorganisms. PCR analysis coupled with cDNA cloning and sequencing revealed that dermatoxin is expressed in the skin, the intestine and the brain. Preprodermatoxin from the brain and the intestine have the same sequence as the skin preproform except for two amino-acid substitutions in the preproregion of the brain precursor. The dermatoxin precursor displayed the characteristic features of preprodermaseptins, a family of peptide precursors found in the skin of Phyllomedusa ssp. Precursors of this family have a common N-terminal preproregion followed by markedly different C-terminal domains that give rise to 19-34-residue peptide antibiotics named dermaseptins B and phylloxin, and to the D-amino-acid-containing opioid heptapeptides dermorphins and deltorphins. Because the structures and cidal mechanisms of dermatoxin, dermaseptins B and phylloxin are very different, dermatoxin extends the repertoire of structurally and functionally diverse peptides derived from the rapidly evolving C-terminal domains of precursors of the dermaseptins family.

Staphylococcus hyicus exfoliative toxin: purification and demonstration of antigenic diversity among toxins from virulent strains.

The exfoliative toxin produced by Staphylococcus hyicus strain 1289D-88 was purified as a single protein of approximately 30 kDa. Extracellular proteins of S. hyicus grown under small scale fermentation conditions were precipitated with ammonium sulfate. Separation of proteins was performed by hydrophobic interaction chromatography and successively anion exchange chromatography. The purified toxin was tested in a piglet skin assay. Weak epidermal lesions were macroscopically and microscopically similar to lesions caused by (NH4)2SO4-precipitated culture supernatant from the same strain. Addition of 0.5 mM CuSo4 to the purified toxin resulted in more intense skin alterations comparable to lesions caused by precipitated culture supernatant diluted 1:10. These results indicated that the activity of the exfoliative toxin was dependent on the presence of Cu2+. Polyclonal and monoclonal antibodies were prepared against the exfoliative toxin from strain 1289D-88. The in vivo activity of the exfoliative toxin could be neutralized by antibodies. It was shown that polyclonal as well as monoclonal antibodies only reacted with the toxin produced by two of nine well-defined virulent strains of S. hyicus. These results showed antigenic diversity among exfoliative toxins produced by different strains of S. hyicus.

Comparison of detection methods for trichothecenes produced by Fusarium sporotrichioides on fodder and grains at different air humidities.

Growth and toxin production of a highly toxic strain of Fusarium sporotrichioides Sherb were studied on oat and wheat grains and on straw under experimental conditions, in which relative humidity (RH) of air was regulated. The materials were incubated at three different RH levels at a range of 84-100%. F. sporotrichioides grew well on oat and wheat grains at RH 97-100% but grew less well at RH 84-88% and on straw. Toxin production was measured with three biological toxicity tests (cytotoxicity test, dermotoxicity test, and yeast cell toxicity test), with chemical analysis, and T-2 ELISA assay. Cytotoxicity and production of trichothecene mycotoxins were detected in all the samples incubated at all three RH levels. On oat and wheat grains, T-2 toxin, neosolaniol, and diacetoxyscirpenol were found, and on straw T-2 toxin, HT-2 toxin, neosolaniol, and T-2 tetraol were determined. In the T-2 ELISA assay, all material samples were found to contain T-2 toxin. The cytotoxicity test was the most sensitive method for detecting biological toxicity of samples inoculated with fungus. The T-2 ELISA assay and chemical analysis were about equally sensitive to detect T-2 toxin in samples.

[The isolation of the Vibrio cholerae dermotoxin and the characterization of its biological properties]. / Vydelenie dermotoksina Vibrio cholerae i kharakteristika ego biologicheskikh svoistv.

The dermonecrotic factor (dermotoxin) inducing skin necrosis in rabbits has been isolated from V. cholerae strain B-53-2-38 and partially purified. Dermotoxin has a molecular weight of about 110 kD and possesses pronounced cytotoxic and general toxic action, differing from that of enterotoxin. The introduction of this factor into the blood and peritoneum of laboratory animals causes their death.

[Isolation and certain properties of the dermonecrotic toxin from Pasteurella multocida]. / Vydelenie i nekotorye svoistva dermonekroticheskogo toksina Pasteurella multocida.

The procedure for isolation and purification of Pasteurella multocida serovariant D toxin has been described. It includes the three steps of protein precipitation from cultural filtrates by 70% ammonium sulfate, chromatography of the concentrated material on Ultragel AcA44 gel-filtration on Sephracryl S-200. The proposed technique permits one the 155-fold purification of the preparation with 32.6% yield estimated by biological activity. The obtained purified preparation is homogeneous in polyacrylamide gel electrophoresis. The immunological methods also confirm the homogeneity of the preparation. The minimal dermonecrotic dose for guinea pigs of the purified 120 kDa toxin is 78 ng and LD50 for mice is 280 ng. Pasteurella multocida toxin is found to be a thermolabile protein sensitive to trypsin, glutaraldehyde and formaldehyde treatments.

[Morphological changes caused by the dermonecrosis factor of the causative agents of cholera and various other intestinal infections]. / Morfologicheskie izmeneniia vyzvannye dermonekroticheskim faktorom vozbuditelei kholery i nekotorykh drugikh kishechnykh infektsii.

Intra- or subepithelial focal purulent inflammation with necrosis of exudating leucocytes during 1-2 days is developed in consequence of intradermal injection of the living cholera vibrios, cultured on membrane agar, or their supernatants. Sometimes coagulative necrosis of cover epithelium arises without preliminary purulent inflammation stage from the very beginning. Intradermal injection of living cholera vibrios leads to the development of coagulative necrotic foci in derma too. The vascular genesis of alterations mentioned above is supposed.

Dermonecrotic toxin and tracheal cytotoxin, putative virulence factors of Bordetella avium.

We examined Bordetella avium for virulence factors common to Bordetella pertussis, including pertussis toxin, filamentous hemagglutinin, adenylate cyclase, dermonecrotic toxin, and tracheal cytotoxin. B. avium produced a dermonecrotic toxin and a tracheal cytotoxin. The dermonecrotic toxin of B. avium is a 155,000-molecular-weight, heat-labile protein which was lethal for mice, guinea pigs, young chickens, and turkey poults and produced dermonecrosis when injected intradermally into guinea pigs, chickens, and turkey poults. High-pressure liquid chromatography of B. avium culture supernatant fluid revealed the presence of a tracheal cytotoxin chemically identical to that produced by B. pertussis. B. avium isolates were negative for B. pertussis-like filamentous hemagglutinin and pertussis toxin when assayed with antibody against B. pertussis filamentous hemagglutinin and pertussis toxin. Furthermore, B. avium failed to induce the clustered CHO cell morphology characteristic of pertussis toxin. Adenylate cyclase assays indicated that B. avium does not produce an extracytoplasmic adenylate cyclase, even after passage through embryonated turkey eggs. Since production of virulence proteins by B. pertussis is regulated by growth in media containing nicotinamide or MgSO4 or by growth at reduced temperatures, we determined the effect of these supplements and growth conditions on production of dermonecrotic toxin by B. avium. Production of dermonecrotic toxin in B. avium was not altered by growth in media containing 100 microM FeSO4 or 500 micrograms of nicotinamide per ml or by growth at 25 or 42 degrees C, but production was significantly decreased by growth in media containing 20 mM MgSO4 and slightly reduced by growth in media containing 500 micrograms of nicotinic acid per ml. These studies revealed that B. avium is similar to B. pertussis in that both species produce a dermonecrotic toxin and a tracheal cytotoxin and production of dermonecrotic toxin is regulated by nicotinamide and MgSO4. The presence of dermonecrotic toxin and tracheal cytotoxin in all Bordetella species indicates that these products may be important virulence factors in bordetellosis.

Intracellular locations of dermonecrotic toxins in Pasteurella multocida and in Bordetella bronchiseptica.

Location of dermonecrotic toxin (DNT) in the cells of Pasteurella multocida or Bordetella bronchiseptica was investigated. After cell lysis by various procedures, various fractions prepared from bacterial cells grown in liquid culture media were assayed for dermonecrotic activity by skin testing of guinea pigs. During the death phase of the growth tested for the 2 bacterial species, little cell-free DNT was detected in the culture supernatants. Throughout the log and stationary phases of the growth, DNT activity was cell associated, but was not seen in the culture supernatants, which indicated that DNT was not secreted by actively growing P multocida or B bronchiseptica cells. Little DNT was released by subjecting whole cells to osmotic shock, a common procedure that releases proteins from the periplasmic space of many gram-negative bacteria. After sonication and centrifugation of whole cells, a substantial amount of DNT was released; results were similar when spheroplasts were used instead of whole cells. Treatment of whole cells with trypsin did not decrease the DNT activity, but trypsin treatment of sonicated cells resulted in a significant decrease in the DNT activity (P less than 0.01). The results indicated an intracellular location of the DNT of P multocida or B bronchiseptica. The DNT of P multocida or of B bronchiseptica is probably located in the cytoplasmic space.