Skin donations after suicide by acute poisoning.

The demand for skin tissue allografts to treat burns and other types of injuries increases each year to the extent that categories of donors formerly deemed "unsuitable", such as victims of suicide by polytrauma or poisoning, are now considered. Patients who died by ingestion of/exposure to toxic substances can be accepted as tissue donors after assessment of graft safety to rule out any risks of transferring toxic substances to the recipient. A cadaveric skin donation was obtained from a 57-year-old woman who died from intoxication after ingesting colchicine tablets (0.2 mg/kg). To determine the safety of cadaveric skin allografts, high-performance liquid chromatography-mass spectrometry (LC-MS/MS) was used to identify and quantify colchicine in procured skin. Results revealed that colchicine concentrations were lower than the instrument limit of detection (LOD) of 0.5 ng/mg both in epidermis and dermis. Cell viability assessed through the MTT ([3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide]) test was within standard limits. Thanks to accurate tests performed, which are routinely applied also in clinical diagnostics and forensic toxicology, it was possible to ascertain the safety and suitability of skin tissue for donation.

[Determination of absence of drug dependence: procedures to follow and role of the surveillance body]. / Accertamento di assenza di tossicodipendenza: le procedure da adottare ed il ruolo dell'organo di vigilanza.

The assessment of presence or absence of substance addiction in subjects working in activities potentially harmful for themselves or others, is indeed an important issue and a compulsory activity. Nevertheless, according to Italian laws (outlined in the agreement on the ascertainment of the absence of drug addiction, executed in the session of October 30th 2007), only occupational company doctors are in charge of such a duty. This professional figure should instead be mainly aimed to protect worker's health. Furthermore, private workers, even in settings or jobs at risk (e.g. bus drivers) are automatically excluded from such a verification. In this case, third parties (e.g. bus passengers) are protected by the law only when the worker is employed in a company. The new procedures, recently promulgated by central and regional governments, increase the burden of occupational company doctors, and introduce restrictions for workers of particular activities, in the case of a positive laboratory result for prohibited substances.

Differential effects of amphotericin B and liposomal amphotericin B on inflammatory cells in vitro.

OBJECTIVE AND DESIGN: To understand whether the pseudo-allergic reactions to amphotericin B (AmB) administration are due to AmB or to the solubilizing vehicles, a study was designed to evaluate the effects of AmB, liposomal AmB, (L-AmB), AmB-deoxycholate micellar complex (AmB-DC) and deoxycholate (DC) on the responses of rat serosal mast cells (RSMC) and of human basophils (HB), in vitro. MATERIALS AND METHODS: Serosal mast cells were obtained by density gradient centrifugations from male Wistar albino rats. Partially purified HB were obtained from healthy donors. The cells were exposed to AmB, L-AmB, AmB-DC and DC. Histamine release was measured fluorometrically, and the release of lactic dehydrogenase (LDH) was measured spectrophotometrically. HB activation was evaluated cytofluorimetrically by CD63 expression. RESULTS: AmB and L-AmB did not evoke histamine or LDH release from either RSMC or HB. CD63 expression was not induced in HB challenged with AmB and L-AMB. On the other hand, AmB-DC and DC produced a cytotoxic histamine release from both RSMC and HB, and a sustained increase of CD63 expression on HB. CONCLUSIONS: Only AmB-DC was able to induce the release of inflammatory mediators from RSMC and HB. Conceivably, the cytotoxic effect is accounted for by the micellar complexes with DC, which has been confirmed as a powerful histamine releaser, and held responsible for the pseudo-allergic reactions after AmB-DC administration. The data lend support to a better safety profile of L-AmB.

Modulation of the immunological response of guinea pig mast cells by carbon monoxide.

Challenge of guinea pig mast cells with antigen under aerobic conditions induced the expected release of histamine and led to a significant increase in intracellular calcium ([Ca2+]i) and cyclic adenosine monophosphate (cAMP) levels. Prior exposure to CO decreased the immunological histamine release. This effect was accompanied by a decrease in the levels of [Ca2+]i and by an increase in the cyclic guanosine monophosphate (cGMP) levels. The exposure of mast cells to nitrogen (N2) did not modify the release of histamine. The CO-mediated inhibition of the immunological release of histamine was reversed by the soluble guanylate cyclase inhibitor (1 H-[1.2,4]oxadiazolo[4,3-a]quinoxalin-1-one, ODQ) and by oxyhaemoglobin (HbO2). Incubation of mast cells for 4 h with hemin, a heme oxygenase (HO) inducer, resulted in an increase in HO activity, measured as bilirubin production. Hemin abated the immunological release of histamine, in similar fashion to exogenous CO, and increased the cGMP levels. These effects were reversed by ODQ and HbO2. It is proposed that CO from an exogenous or endogenous source stimulates guanylyl cyclase and causes cGMP formation which then induces calcium to be sequestrated so that the [Ca2+]i concentration falls and histamine release is inhibited.

The role of histamine in platelet aggregation by physiological and immunological stimuli.

BACKGROUND: Platelets participate in allergic and inflammatory processes beside their role in haemostasis and thrombosis. This paper reports the level, the uptake, the metabolism and the release of histamine in human platelets. The effects of exogenous histamine, as well as the receptor and signal transduction of these effects, are also described. METHODS: Purified suspensions of platelets, prepared from healthy volunteers and from atopic patients, were exposed in vitro to physiological and immunological stimuli. Platelet aggregation was measured by the increase in light transmission; histamine content and release, as well as cytosolic free Ca2+ concentration, were measured fluorimetrically. Platelet histamine forming capacity, and the uptake of exogenous histamine, were measured with a radioisotopic method. RESULTS: Human platelets contain 72.5 +/- 9.6pmoles of histamine x 10(9) platelets, and their capacity to form histamine is 18.7 +/- 3.5pmoles h(-1)g(-1) protein, which is reduced by alpha-fluoromethylhistidine (10(-5) M) a selective inhibitor of the specific histidine decarboxylase. Human platelets take up the preformed amine by a calcium and energy-dependent process, and the uptake of histamine is reduced by mepyramine, an H1-receptor antagonist, and N,N-diethyl-2-[4-(phenylmethyl) phenoxyl] ethanamine (10(-6) M), a blocker of intracellular histamine receptors. Histamine is also metabolized by human platelets. The exposure of platelets to thrombin (10-60 mUml(-1)) produced a progressive aggregation, associated with histamine release. The same is observed in platelets isolated from atopic patients exposed to anti-IgE antibodies. Exogenous histamine dose-dependently potentiates the aggregation induced by physiological and immunological stimuli. In resting platelets cytosolic calcium level (207 +/- 4.2 nM/10(8) platelets) is increased by thrombin as well as by anti-IgE; this effect is potentiated by 10(-5) M histamine. CONCLUSIONS: The synergistic effect between histamine and other monoamines on platelet aggregation may explain some aspects of allergic vasculitis in which platelet aggregation is present.

Recombinant human erythropoietin and high flux haemodiafiltration.

Since 1982, 32 uraemic patients were treated in our institution by high flux haemodiafiltration (H-HDF) in order to shorten significantly the dialytic treatment session. H-HDF used a high surface area filter (1.4-1.9 m2) with high hydraulic permeability (polyacrylonitrile and polysulfone), at high blood flow (450 ml/min) and high rates of reinfusion of substitution fluid (22 l/session). In this way the dialytic session was shortened to 140 +/- 19 min, maintaining a good cardiovascular stability and high dialytic efficiency (Kt/V > 1.1). Human recombinant erythropoietin rHuEpo introduced in the therapy of this group in 1987 has resulted in an improvement of renal anaemia, but also a prolongation of the time of dialytic treatment due to a decrease in the efficiency of filters. During the period of the study, the treatment time increased from 140 +/- 19 min to 168 +/- 25 min with a concomitant increase of haematocrit and haemoglobin (from 24% to 36% and from 7.9 to 10.5 g/dl, respectively). H-HDF maintains a noticeable increase in dialytic efficacy with good cardiovascular stability, but the goal of a significant reduction in the time of treatment can no longer be obtained.