Effectiveness of confidential unit exclusion in screening blood donors of the regional blood bank in Londrina, Paraná State

BACKGROUND: For transfusion purposes, blood donors must be accepted both in clinical and serological evaluations and must not have excluded their own donation using the confidential unit exclusion. AIMS: The objective of this study was to verify whether blood donors who choose self exclusion are more likely to be positive in serological tests than donors who do not. METHODS: A cross-sectional analysis was carried out of 51,861 consecutive whole blood donations from January 2004 to December 2008 at a public blood bank in Londrina, Southern Brazil. RESULTS: Self exclusion was chosen in 1672 (3.2 percent) donations, most frequently by first-time blood donors (p-value < 0.0001), by blood donors from external collections (p-value < 0.0001), by men (p value < 0.0001) and by under 30-year-old donors (p-value < 0.0001). The frequency of positive serology was 5.3 percent in the group that chose self exclusion and 3.5 percent in the group that did not choose self exclusion (p-value < 0.0001). CONCLUSIONS: These results show that confidential unit exclusion used in this blood bank is effective and is inexpensive. However, the diagnostic power to detect blood-borne infections was low and resulted in the discard of a high number of blood bags without any direct or indirect serologic markers of pathogens. The use of confidential unit exclusion could be replaced with molecular tests to screen blood donors.

Effectiveness of confidential unit exclusion in screening blood donors of the regional blood bank in Londrina, Paraná State.

BACKGROUND: For transfusion purposes, blood donors must be accepted both in clinical and serological evaluations and must not have excluded their own donation using the confidential unit exclusion. AIM: The objective of this study was to verify whether blood donors who choose self exclusion are more likely to be positive in serological tests than donors who do not. METHODS: A cross-sectional analysis was carried out of 51,861 consecutive whole blood donations from January 2004 to December 2008 at a public blood bank in Londrina, Southern Brazil. RESULTS: Self exclusion was chosen in 1672 (3.2%) donations, most frequently by first-time blood donors (p-value < 0.0001), by blood donors from external collections (p-value < 0.0001), by men (p value < 0.0001) and by under 30-year-old donors (p-value < 0.0001). The frequency of positive serology was 5.3% in the group that chose self exclusion and 3.5% in the group that did not choose self exclusion (p-value < 0.0001). CONCLUSIONS: These results show that confidential unit exclusion used in this blood bank is effective and is inexpensive. However, the diagnostic power to detect blood-borne infections was low and resulted in the discard of a high number of blood bags without any direct or indirect serologic markers of pathogens. The use of confidential unit exclusion could be replaced with molecular tests to screen blood donors.

Allosteric interaction of the anticholinergic drug [N-(4-phenyl)-phenacyl-l-hyoscyamine] (Phenthonium) with nicotinic receptors of post-ganglionic sympathetic neurons of the rat vas deferens.

Phenthonium (Phen), a quaternary analog of hyoscyamine, is a blocker of muscarinic activity and an allosteric blocker of alpha(1)2betagammaepsilon nicotinic receptors. Specifically, Phenthonium increases the spontaneous release of acetylcholine at the motor endplate without depolarizing the muscle or inhibiting cholinesterase activity. This paper compares Phenthonium's effects on sympathetic transmission and on ganglionic nicotinic receptor activation. Neurotransmitter release and twitch of the rat vas deferens were induced either by electrical stimulation or by 1,1-dimethyl-4-phenylpiperazine (DMPP) activation of nicotinic receptors. Contractions independent of transmitter release were induced by noradrenaline and adenosine 5'-triphosphate (ATP). Phenthonium inhibited transmitter release and depressed twitch without changing the responsiveness to noradrenaline or ATP. Twitch depression did not occur after K(+)-channel blockade with 4-aminopyridine (4-AP) or charybdotoxin. DMPP had a similar effect, but high concentrations induced contraction of non-stimulated organs. Incubation of Phenthonium inhibited further DMPP twitch depression and non-competitively depressed the contractile responses elicited by DMPP. Furthermore, mecamylamine, but neither methyllycaconitine nor atropine, blocked the contraction elicited by DMPP. Phenthonium and DMPP are K(+)-channel openers that primarily inhibit sympathetic transmission. Contraction induced by DMPP was probably mediated by neuronal nicotinic receptor other than the alpha7 subtype. The blockade of DMPP contractile response was unrelated to Phenthonium's antimuscarinic or K(+)-channel opening activities. Since Phenthonium's quaternary chemical structure limits its membrane diffusion, the non-competitive inhibition of DMPP excitatory responses should be linked to allosteric interaction with neuronal nicotinic receptors that putatively qualify Phenthonium as a novel modulator of cholinergic synapses.

Measurement of cytotoxic activity in experimental cancer.

Several tumor cell systems have been developed for investigating the cytotoxic activity of different substances. The Ehrlich ascytic tumor (EAT) has been studied extensively and used to increase our comprehension of immunotherapy (Yamamoto and Naraparaju. Cancer Res 57:2187-2192, 1997). In this study, we evaluated the ability of an enzymatic method to assess cytotoxic tumor activity in vitro. To prepare cytotoxic cells, lymphoid cells isolated from the lymph nodes of C57BL/6 mice were activated with interleukin-2 (IL-2). The cytotoxic activity to EAT cells was assessed by an enzymatic test using lactate dehydrogenase (LDH), an enzyme widely distributed in mammalian tissues which, in the presence of NAD/NADH, converts lactate to pyruvate. IL-2 treatment of lymph node cells induced a greater percentage of lysis (75.47%) than effector cells that were not treated with IL-2 (42.38%). This suggests that IL-2 directly activates effector cells and not tumor cells. The results demonstrate that the LDH release-measurement method can be utilized to assay cytotoxic cell-mediated activity in which murine tumor cells act as the target. Levels of IL-2 appear to have a direct correlation to cellular immunity and treatment with these substances may strengthen immune function and decrease the pace of disease development.

A importância dos exames laboratoriais no monitoramento da doença de Graves e artrite reumatóide / The laboratorial tests and its importance in the clinical course of therapeutic monitoring in Graves' disease and rheumatoid arthritis

A auto-imunidade se manifesta quando ocorre uma falha nos mecanismos de auto-tolerância responsáveis pela discriminação entre o próprio e o não próprio, desencadeando uma resposta imune adaptativa específica contra os auto-antígenos. A doença de Graves (DG), uma doença auto-imune associada com atividade excessiva da tireóide, podendo vir associada a outras doenças auto-imunes endócrinas, como Diabetes mellitus tipo 1, e não endócrinas como Lupus Eritematoso Sistêmico (LES) ou Artrite Reumatóide (AR). As doenças auto-imunes são caracterizadas pela etiologia multifatorial, onde fatores genéticos, endócrinos, imunológicos, infecciosos, ambientais e emocionais contribuem para o desencadeamento e agravamento dos processos lesivos. Tem-se pesquisado cada vez mais a influência de fatores genéticos sobre o desenvolvimento de doenças auto-imunes e é neste contexto que se observa a forte associação do HLA-DR, tanto com DG como com AR. O presente trabalho tem como objetivo descrever as alterações laboratoriais observadas em uma paciente do sexo feminino, 22 anos, branca, com o diagnóstico das duas doenças auto-imunes de evolução crônica, a DG e AR, correlacionar os resultados laboratoriais com os sinais e sintomas clínicos apresentados e avaliar os exames laboratoriais realizados para o monitoramento clínico e terapêutico.