ESTUDO ANATOMOPATOLÓGICO DE ALEVINOS DE JUNDIÁ INFECTADOS EXPERIMENTALMENTE POR Ichthyophtirius multifiliis E SUBMETIDOS A TRATAMENTOS CONVENCIONAIS

The white spot disease is caused by Ichthyophthirius multifiliis (ich), a ciliated parasite characterized by its relatively large size, compared to other protozoans. Ich, one of the most devastating parasites affecting jundia culture, may destroy entire populations within a few hours. This study evaluated the histological effect of ich infection under some conventional treatments on jundia fingerlings. Fifteen fish (3-6 cm) were placed in 21 aquaria (10 L) for 5 days. The following treatments were used: C1: non infected control; C2: infected control; F: formalin (0.2 ml/L); M: malachite green (0.1ml/L); and S: NaCl 1% (10g/L). The treatments were used as 3 baths of 1 h between intervals of 48 h. Total mortality of F fish occurred within 48 h, showing that formalin was toxic to jundia under concentration recommended for parasite treatment of most tropical fish species. The lowest mortality rate (33%) was observed for S fish. The histological evaluation showed that ich caused hyperemia and hyperplasia of gill cells surrounding the parasite. At 96 h, trophozoites were observed with the help of microscope (40x) under the skin of C1 fish. Ich was not visible to the naked eye on C1 fish at the beginning of the experimental period. Tomites, a young stage of ich, burrowed into the skin of jundia, penetrated the subepithelial layer and caused damage. Upper layers of skin were sloughed off within 96 h from fish of all treatments, except S fish. Ich irritates fish tissues, mainly the gill cells, and causes high mortality rate within a very short period of time. Additionally, the employed therapeutic treatments cause adverse changes to different levels of severity, mainly on the gill tissue.A doença dos pontos brancos é causada pelo parasita ciliado Ichthyophthirius multifiliis caracterizado pelo seu tamanho relativamente grande quando comparado a outros protozoários. O ictio é responsável pelas maiores perdas observadas na criação do jundiá, podendo destruir toda a população de um viveiro em poucas horas. O presente estudo avaliou e descreveu as alterações patológicas macro e microscópicas causadas pelo ictio em alevinos de jundiá submetidos a tratamentos terapêuticos convencionais. Quinze peixes (3-6 cm) foram estocados em 21 aquários (10 L) e submetidos por cinco dias aos seguintes tratamentos: C1: controle não infectados; C2: controle infectados; F: formalina comercial (0,2ml/l); M: verde malaquita (0,1ml/l); e S: cloreto de sódio 1% (10g/l). Foram realizados três banhos com duração de uma hora e intervalos de 48 horas. Mortalidade total foi observada nos exemplares expostos a formalina por 48 horas, mostrando que alevinos de jundiá são sensíveis a esse produto na concentração recomendada para a maioria das espécies tropicais. A menor taxa de mortalidade (33%) foi registrada para os peixes submetidos ao sal. As análises histológicas denunciaram a presença de hiperemia e hiperplasia nas células do epitélio branquial próximas ao parasita. No grupo C1 foi registrada a presença de trofozoítos nos peixes coletados em 96 horas, sendo que os parasitas não foram observados naqueles peixes, a olho nu, no início do experimento. Tomitos, a forma jovem do parasita, alojaram-se na pele com localização subepidermal e causando lesões. Foi verificada irritação causada pelo ictio em diferentes níveis e em todos os tratamentos, principalmente nas células do epitélio branquial. Próximo ao final do período experimental foi observada esfoliação da pele de peixes de todos os tratamentos, exceto nos peixes submetidos ao sal comum. A infecção pelo ictio ocorre de forma muito rápida e intensa, causando alterações anatomopatológicas severas no tecido branquial e altas taxas de mortalidade em curto período de tempo. Adicionalmente, os tratamentos terapêuticos empregados causam reações adversas no jundiá em graus variados de severidade, principalmente no tecido branquial

Use of porcine intestinal submucous conserved in neomycin sulphate in esophagus graft in dog

It has been verified the effectiveness of the porcine intestinal submucous as an alternative to replace three centimeters of cervical esophagus in dog and the use of neomycin sulphate as a way for the conservation of this biological membrane. In these studies sixteen adult animals were used, four animals being evaluated for seven days, four for fifteen days, four for thirty days and the remaining four were observed for forty-five days after the surgery. The postoperative evaluation consists of clinical and laboratory examinations, and at the end of the post-operation followup period they were euthanized and underwent necropsy, the grafted area was harvested for a histopathological exam. This research made it possible to conclude that the use of a biological membrane, replacing part of the canine cervical esophagus is an executable method as it allows a quick epithelial proliferation. The area of graft at the 30 days after the surgery period showed, to be not functionally effective in the studied proportions (substitution of three centimeters of cervical esophagus) displaying in all the operated animals, stenosis and consequently chokes, hypoxia, lack of nutrition and cachexia. The authors consider that the esophagus follows being a surgical challenge.Verificou-se a eficácia da submucosa intestinal porcina como alternativa para substituir três centímetros de esôfago cervical em cão, e o uso de sulfato de neomicina como meio de conservação desta membrana biológica. Nestes estudos foram utilizados dezesseis cães adultos, sendo quatro avaliados durante sete dias, quatro durante 15 dias, quatro durante 30 dias e os restantes avaliados durante 45 dias de período pós-operatório. A avaliação pós-operatória constitui-se de exames clínicos e laboratoriais, e ao final do período de acompanhamento, foram submetidos à eutanásia para exame de necropsia e colheita da área enxertada para avaliação histopatológica. Este trabalho possibilitou concluir que o emprego desta membrana biológica na forma como foi conservada, permite a substituição de parte de esôfago cervical canino, proporcionando rápida e completa proliferação epitelial. A área de enxertia aos 30 dias do período pós-operatório mostrou-se ineficaz sob o ponto de vista funcional, nas medidas estudadas (substituição de três centímetros de esôfago cervical), pois ocorreram em todos os animais operados, estenoses e conseqüentemente engasgos, hiporexia, desnutrição e caquexia. Os autores consideram que o esôfago continua sendo um desafio cirúrgico

Observation of hard scattering in photoproduction events with a large rapidity gap at HERA

Events with a large rapidity gap and total transverse energy greater than 5 GeV have been observed in quasi-real photoproduction at HERA with the ZEUS detector. The distribution of these events as a function of the $\gamma p$ centre of mass energy is consistent with diffractive scattering. For total transverse energies above 12 GeV, the hadronic final states show predominantly a two-jet structure with each jet having a transverse energy greater than 4 GeV. For the two-jet events, little energy flow is found outside the jets. This observation is consistent with the hard scattering of a quasi-real photon with a colourless object in the proton.Comment: 19 pages, latex, 4 figures appended as uuencoded fil

D* Production in Deep Inelastic Scattering at HERA

This paper presents measurements of D^{*\pm} production in deep inelastic scattering from collisions between 27.5 GeV positrons and 820 GeV protons. The data have been taken with the ZEUS detector at HERA. The decay channel $D^{*+}\to (D^0 \to K^- \pi^+) \pi^+$ (+ c.c.) has been used in the study. The $e^+p$ cross section for inclusive D^{*\pm} production with $5<Q^2<100 GeV^2$ and $y<0.7$ is 5.3 \pms 1.0 \pms 0.8 nb in the kinematic region {$1.3<p_T(D^{*\pm})<9.0$ GeV and $| \eta(D^{*\pm}) |<1.5$}. Differential cross sections as functions of p_T(D^{*\pm}), $\eta(D^{*\pm}), W$ and $Q^2$ are compared with next-to-leading order QCD calculations based on the photon-gluon fusion production mechanism. After an extrapolation of the cross section to the full kinematic region in p_T(D^{*\pm}) and $\eta$(D^{*\pm}), the charm contribution $F_2^{c\bar{c}}(x,Q^2)$ to the proton structure function is determined for Bjorken $x$ between 2 $\cdot$ 10$^{-4}$ and 5 $\cdot$ 10$^{-3}$.Comment: 17 pages including 4 figure

Observation of Scaling Violations in Scaled Momentum Distributions at HERA

Charged particle production has been measured in deep inelastic scattering (DIS) events over a large range of $x$ and $Q^2$ using the ZEUS detector. The evolution of the scaled momentum, $x_p$, with $Q^2,$ in the range 10 to 1280 $GeV^2$, has been investigated in the current fragmentation region of the Breit frame. The results show clear evidence, in a single experiment, for scaling violations in scaled momenta as a function of $Q^2$.Comment: 21 pages including 4 figures, to be published in Physics Letters B. Two references adde

Observation of Events with an Energetic Forward Neutron in Deep Inelastic Scattering at HERA

In deep inelastic neutral current scattering of positrons and protons at the center of mass energy of 300 GeV, we observe, with the ZEUS detector, events with a high energy neutron produced at very small scattering angles with respect to the proton direction. The events constitute a fixed fraction of the deep inelastic, neutral current event sample independent of Bjorken x and Q2 in the range 3 · 10-4 \u3c xBJ \u3c 6 · 10-3 and 10 \u3c Q2 \u3c 100 GeV2

Study of D*(2010)+- Production in ep Collisions at HERA

We report the first observation of charmed mesons with the ZEUS detector at HERA using the decay channel D*(+) --> (D-0 --> K(-)pi(+)) pi(+) (+ c.c.). Clear signals in the mass difference Delta M=M(D*)-M(D-0) as well as in the M(K pi) distribution at the D-0 mass are found. The ep cross section for inclusive D*(+/-) production with Q(2) c $($) over bar cX)=(0.45+/-0.11(-0.22)(+0.37)) mu b at root s=296 GeV and [W]=198 GeV. The average gamma p charm cross section sigma(gamma p --> c $($) over bar cX) is found to be (6.3+/-2.2(-3.0)(+6.3)) mu b at [W]=163 GeV and (16.9+/-5.2(-8.5)(+13.9)) mu b at [W]=243 GeV. The increase of the total charm photoproduction cross section by one order of magnitude with respect to low energy data experiments is well described by QCD NLO calculations using singular gluon distributions in the proton