Morphometric analysis of the phrenic nerve in male and female Wistar-Kyoto (WKY) and spontaneously hypertensive rats (SHR)

Ventilatory differences between rat strains and genders have been described but the morphology of the phrenic nerve has not been investigated in spontaneously hypertensive (SHR) and normotensive Wistar-Kyoto (WKY) rats. A descriptive and morphometric study of the phrenic nerves of male (N = 8) and female (N = 9) SHR, and male (N = 5) and female (N = 6) WKY is presented. After arterial pressure and heart rate recordings, the phrenic nerves of 20-week-old animals were prepared for epoxy resin embedding and light microscopy. Morphometric analysis performed with the aid of computer software that took into consideration the fascicle area and diameter, as well as myelinated fiber profile and Schwann cell nucleus number per area. Phrenic nerves were generally larger in males than in females on both strains but larger in WKY compared to SHR for both genders. Myelinated fiber numbers (male SHR = 228 ± 13; female SHR = 258 ± 4; male WKY = 382 ± 23; female WKY = 442 ± 11 for proximal right segments) and density (N/mm²; male SHR = 7048 ± 537; female SHR = 10355 ± 359; male WKY = 9457 ± 1437; female WKY = 14351 ± 1448) for proximal right segments) were significantly larger in females of both groups and remarkably larger in WKY than SHR for both genders. Strain and gender differences in phrenic nerve myelinated fiber number are described for the first time in this experimental model of hypertension, indicating the need for thorough functional studies of this nerve in male and female SHR.

In vitro study on thiabendazole action on viability of Ascaris lumbricoides (Lineu, 1758) eggs

The in vitro activity of thiabendazole on Ascaris lumbricoides eggs, which were recovered from uteri of worm excreted after chemotherapeutic treatment, was studied. Four concentrations of the drug were used: 1 - 2.5 - 5 - and 10 ppm during 24, 48 and 72 hours of exposure. Subsequently, the eggs were centrifuged, washed three times and H(2)SO(4)0.1N was added. The eggs were maintained in an incubator for 20 days at 28 degrees C. Finally, the percentage of embryonated eggs was determined under a lightmicroscope at a 100X magnification. After 48 and 72 hours of thiabendazole exposure, at a concentration of 10ppm, the drug showed complete inhibition of egg embryonation.

Foi estudada, in vitro, a ação do tiabendazol, contra ovos de Ascaris lumbricoides , retirados de úteros de vermes eliminados após tratamento. Foram utilizadas quatro concentrações da droga: 1 ¾ 2,5 - 5 e 10 ppm em três diferentes períodos de tempo: 24, 48 e 72 horas. Decorridos estes tempos a suspensão com os ovos foi centrifugada, lavada por três vezes com água destilada, adicionada de solução de H2SO4, 0,1N e mantida em estufa a 28°C por 20 dias. Em seguida, os ovos foram levados ao microscópio óptico, no aumento de 100X, para observação do percentual de embrionamento. Na concentração de 10ppm, nos tempos de 48 e 72 horas de exposição à droga, verificou-se completa inibição do embrionamento dos ovos.

Investigacao sobre a passagem transplacentaria de microfilarias de Wuchereria bancrofti em recem-nascidos de maes microfilaremicas / Investigation on transplacental passage of Wuchereria bancrofti microfilariae in newborns of microfilaremic mothers

A ocorrencia de microfilarias circulantes de Wuchereria bancrofti foi pesquisada em 304 gestantes da Unidade Mista Prof. Barros Lima e do Hospital das Clinicas da Universidade Federal de Pernambuco pelo Centro de Pesquisas Aggeu Magalhaes. A microfilaremia materna foi investigada pela filtracao de sangue venoso, sendo encontrados 13 casos positivos (4,2 por cento). A pesquisa de microfilarias no sangue do cordao umbilical de suas criancas foi negativa (6/13), assim como no sangue periferico destas ate 72 horas pos-parto e com 6 meses de vida. As amostras de leite coletadas destas maes tambem nao apresentaram microfilarias. Os autores sugerem que a ocorrencia de lesoes placentarias seja um possivel fator envolvido na passagem transplacentaria de microfilarias, e que a exposicao in utero a microfilarias e/ou antigeno filarial possam influenciar a resposta a uma infeccao filarial adquirida posteriormente, sendo importante o acompanhamento clinico e laboratorial de criancas expostas previamente a antigenos filariais em periodos precoces do desenvolvimento humano.