铁皮石斛试管苗快速繁殖的研究

兰科植物铁皮石斛(Dendrobium candidum Wall.ex Lind1.)的茎为常用名贵中药。多年来,主要依靠采收野生品种供药用和出口,致使野生资源枯竭,现已成为日益稀少的濒危植物。兰属种子和石斛属种子试管繁殖已积累不少资料,但是有关铁皮石斛种子试管繁殖的研究只有少量简单的报道,对其种子在试管繁殖过程中,所需外界条件的研究也不够     

Leishmaniasis in Portugal: enzyme polymorphism of Leishmania infantum based on the identification of 213 strains

This study reports isoenzyme polymorphism of Leishmania strains isolated in different regions of Portugal between 1982 and 2005. A total of 213 strains were obtained from cases of visceral and cutaneous leishmaniasis isolated from immunocompetent patients (adults and children) and immunocompromised adults, as well as from dogs and sandflies. Four zymodemes were identified: MON-1, MON-24, MON-29 and MON-80. Zymodeme MON-1 was identified in 96.7% of the strains, predominating in both immunocompetent and immunocompromised human patients, and it was the only zymodeme isolated from dogs. Isoenzyme diversity in HIV-infected patients was higher than in the immunocompetent group, in which all the strains from visceral leishmaniasis were MON-1. The domestic dog was confirmed as the reservoir host of zoonotic leishmaniasis in Portugal and Phlebotomus perniciosus and Phlebotomus ariasi as vectors. The overall low enzyme polymorphism observed in the Portuguese foci contrasts with the neighbouring foci in Spain.     

4α-phorbol 12,13-didecanoate activates cultured mouse dorsal root ganglia neurons independently of TRPV4

Background and Purpose

The Ca²⁺-permeable cation channel TRPV4 is activated by mechanical disturbance of the cell membrane and is implicated in mechanical hyperalgesia. Nerve growth factor (NGF) is increased during inflammation and causes mechanical hyperalgesia. 4α-phorbol 12,13-didecanoate (4αPDD) has been described as a selective TRPV4 agonist. We investigated NGF-induced hyperalgesia in TRPV4 wild-type (+/+) and knockout (–/–) mice, and the increases in [Ca²⁺]_i produced by 4αPDD in cultured mouse dorsal root ganglia neurons following exposure to NGF.

Experimental Approach

Withdrawal thresholds to heat, von Frey hairs and pressure were measured in mice before and after systemic administration of NGF. Changes in intracellular Ca²⁺ concentration were measured by ratiometric imaging with Fura-2 in cultured DRG and trigeminal ganglia (TG) neurons during perfusion of TRPV4 agonists.

Key Results

Administration of NGF caused a significant sensitization to heat and von Frey stimuli in TRPV4 +/+ and –/– mice, but only TRPV4 +/+ mice showed sensitization to noxious pressure. 4αPDD stimulated a dose-dependent increase in [Ca²⁺]_i in neurons from +/+ and –/– mice, with the proportion of responding neurons and magnitude of increase unaffected by the genotype. In contrast, the selective TRPV4 agonist GSK1016790A failed to stimulate an increase in intracellular Ca²⁺ in cultured neurons. Responses to 4αPDD were unaffected by pretreatment with NGF.

Conclusions and Implications

TRPV4 contributes to mechanosensation in vivo, but there is little evidence for functional TRPV4 in cultured DRG and TG neurons. We conclude that 4αPDD activates these neurons independently of TRPV4, so it is not appropriate to refer to 4αPDD as a selective TRPV4 agonist.     

The (in)visibility of psychological family violence in childhood and adolescence

Psychological family violence in childhood and adolescence is still poorly studied, due to difficulties in its definition and detection. This article aims to examine how psychological family violence reported by children and adolescents has been addressed in academic studies, using a literature review (LILACS, MEDLINE, SciELO, PubMed, CAPES Portal, PsycINFO, and SCOPUS databases). Among 51 epidemiological studies, 16 articles met the review's objectives; some of the articles reported a high prevalence of such violence. The study showed that the issue has been studied more in the international literature than in Brazil, which has significantly increased its visibility in the last decade but still faces difficulties involving definition, conceptualization, and operationalization. Eliminating the invisibility of psychological violence in the family could help promote prevention of such violence and protection of children and adolescents.     

Performance of immunoblotting in diagnosis of visceral Leishmaniasis in human immunodeficiency virus-Leishmania sp.-coinfected patients

This study evaluated the performance of immunoblotting with Leishmania infantum soluble antigens for the diagnosis of visceral leishmaniasis in human immunodeficiency virus (HIV)-infected and immunocompetent patients and assessed the humoral responses of patients coinfected with HIV and Leishmania. In this work, the results of the immunoblot analysis were compared to those of parasitological examination (Giemsa-stained smears and/or parasite isolation in Novy, Nicolle, and MacNeal medium from bone marrow) and indirect immunofluorescence and counterimmunoelectrophoresis techniques. Patients were considered to be infected if one or more of the comparison techniques gave a positive result. Immunoblotting was considered to be positive if at least one band was present. For 198 HIV-positive patients with a clinical suspicion of visceral leishmaniasis, immunoblot analysis had a sensitivity of 70.6%, a specificity of 73.2%, and an accuracy of 72.7%. For a separate group of 40 immunocompetent patients not infected with Leishmania, the immunoblot analysis was negative for all patients (100% specificity), and for a third group of 32 immunocompetent patients with confirmed visceral leishmaniasis, the immunoblot analysis was positive for all patients (100% sensitivity). Sera of coinfected patients recognized few bands and recognized bands at lower intensities compared with sera from immunocompetent patients. The most frequently detected band was 63 to 66 kDa (55.9%), with the difference being statistically significant compared to frequency of detection of the other bands. This study confirms that the humoral response in patients coinfected with HIV and Leishmania is much lower than that in immunocompetent patients and that the immunoblot method is a sensitive, noninvasive, and specific serological technique for the diagnosis of visceral leishmaniasis in immunocompromised patients.