The camp analogue, dbcAMP can stimulate rabbit reproductive functions: I. Effect on ovarian folliculogenesis, ovulation and embryo production

The aim of our study was to examine the influence of administration of N6,2’-dibutyryladenosine 3’5’-cyclic monophosphate (dbcAMP), a cAMP agonist, on ovarian folliculogenesis and atresia, as well as on reproductive efficiency in rabbits, whose ovarian cycle and ovulation was induced by gonadotropins. Ovarian cycle and ovulation of control rabbits were induced by 20 IU/kg PMSG followed by 35 IU/kg hCG administration. Experimental animals received PMSG and hCG together with dbcAMP (at 5, 25 or 50 μg/animal). After ovulation and insemination, the animals were sacrificed. Ovaries were weighted, histological sections of ovaries were prepared, and the presence of ovulated and not ovulated follicles and different stages of atresia was evaluated by light microscopy. The eggs were flushed from the oviducts after insemination and cultured up to blastocyst cell stage. Numbers of ovarian Corpora lutea, ovulated oocytes and oocyte-derived zygotes and embryos reaching hatched blastocyst stage were determined. Administration of dbcAMP (at doses 25 or 50 μg/animal, but not at 5 μg/animal) was able to increase the proportion of follicles with cystic and luteinization-related atresia. Furthermore, dbcAMP (50 μg/animal, but not lower doses) increased the ovarian mass, number of Corpora lutea, number of harvested oocytes, zygotes and embryos at blastocyst stage derived from these zygotes after culture. These data demonstrate that dbcAMP can stimulate rabbit ovarian follicle atresia, ovulation, oocyte, zygote and embryo yield and development. Furthermore, they confirm in the involvement of cyclic nucleotide-dependent intracellular mechanisms in the control of rabbit reproductive functions and potential practical usefulness of dbcAMP in improving animal reproduction and fertility

Comparison of semen characteristics and histological structure of the testis from transgenic and non-transgenic rabbits

[EN] The aim of this study was to compare semen characteristics including sperm quantity, quality, and abnormalities, as well as histological structure of the testis of three-year old transgenic (human clotting factor, hFVIII, gene) and nontransgenic rabbits. For the experiment, 10 transgenic rabbits of F2 and F3 generations and 10 randomly selected non-transgenic males of the same breed and age were used as controls. All males were housed in individual cages, under a the same environmental conditions: photoperiod (14L:10D), temperature (18-20°C), and humidity (65-70%). Semen samples, collected once a week for 20 wk from each control and transgenic male, were analyzed by computer assited semen analysis within a few minutes following natural ejaculation into an artificial vagina. Concentration of spermatozoa was higher in the transgenic than in the non-transgenic group (P<0.001; 316.6±148.8 and 126.7±64.4¿106/ mL, respectively). Significant differences (P<0.1) between transgenic and non-transgenic males were observed also in spermatozoa motility (63.08 vs. 32.60%). Significantly higher (P<0.05) relative volume (8.08±2.89%) and diameter of testicular lumen (36.89±23.11 ¿m) were found in the transgenic animals compared to control animals (16.69±4.70%, 53.89±25.42 ¿m). Our results show that spermatozoa parameters and histological structure of the testis can be used for the characterization of male reproductive traits of older transgenic rabbits.This work was supported by the grant No: 2003 SP51/028 09 00/028 09 03 coordinated by the Slovak Academy of Science and by the grant of Ministry of Agriculture Slovak Republic (RÚVV 07-012). All experiments were approved according to ethical permission No. SK P 28004. We are grateful to Dr. Shoubadeep Roychoudhury for the English correction.Lukac, N.; Massanyi, P.; Flesarova, S.; Danko, J.; Makarevich, A.; Chrenek, P. (2009). Comparison of semen characteristics and histological structure of the testis from transgenic and non-transgenic rabbits. World Rabbit Science. 17(4):221-226. https://doi.org/10.4995/wrs.2009.64722122617

Druse-Induced Morphology Evolution in Retinal Pigment Epithelium

The retinal pigment epithelium (RPE) is a key site of pathogenesis for many retina diseases. The formation of drusen in the retina is characteristic of retinal degeneration. We investigate morphological changes in the RPE in the presence of soft drusen using an integrated experimental and modeling approach. We collect RPE flat mount images from donated human eyes and develop 1) statistical tools to quantify the images and 2) a cell-based model to simulate the morphology evolution. We compare three different mechanisms of RPE repair evolution, cell apoptosis, cell fusion, and expansion, and Simulations of our RPE morphogenesis model quantitatively reproduce deformations of human RPE morphology due to drusen, suggesting that a purse-string mechanism is sufficient to explain how RPE heals cell loss caused by drusen-damage. We found that drusen beneath tissue promote cell death in a number that far exceeds the cell numbers covering the drusen. Tissue deformations are studied using area distributions, Voronoi domains and a texture tensor.Fil: Mazzitello, Karina Irma. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de Mar del Plata; ArgentinaFil: Zhang, Qing. University of Emory; Estados UnidosFil: Chrenek, M. A.. University of Emory; Estados UnidosFil: Family, F.. University of Emory; Estados UnidosFil: Grossniklaus, H. E.. University of Emory; Estados UnidosFil: Nickerson, J. M.. University of Emory; Estados UnidosFil: Jiang, Y.. Georgia State University; Estados Unido

Effect of Nickel Administration in vivo on the Testicular Structure in Male Mice

The aim of this study was to describe the effects of nickel (NiCl2) on murine testicular structure. Experimental animals were injected intraperitoneally with a single dose of 20 mg NiCl2 per kg of body mass (group A, n = 5) and 40 mg NiCl2 per kg b. m. (group B, n = 5). The group without injection (n = 5) was the control (C). Animals were killed 48 hours after administration of nickel. The body mass of animals, the mass of testes and the testes : body mass ratio were not significantly affected. In both experimental groups a significant (p p p < 0.05 - 0.001) after nickel administration. Evaluation of the lumen diameter in the seminiferous tubule showed a significant increase in both experimental groups. The data of the perimeter of seminiferous tubules corresponded with those of the seminiferous tubule diameter. TUNEL assay detected a higher frequency of localized apoptosis in the interstitium of nickel-administered animals compared to control group. Our findings clearly suggest a negative effect of nickel on the structure as well as on the function of the seminferous epithelium at the site of spermatozoa production

Effects of dietary supplementation of nickel and nickel-zinc on femoral bone structure in rabbits

<p>Abstract</p> <p>Background</p> <p>Nickel (Ni) and zinc (Zn) are trace elements present at low concentrations in agroecosystems. Nickel, however, may have toxic effects on living organisms and is often considered as a contaminant. This study reports the effect of peroral administrated Ni or a combination of Ni and Zn on femoral bone structure in rabbits.</p> <p>Methods</p> <p>One month-old female rabbits were divided into three groups of five animals each. Group 1 rabbits were fed a granular feed mixture with addition of 35 g NiCl₂per 100 kg of mixture for 90 days. In group 2, animals were fed a mixture containing 35 g NiCl₂and 30 g ZnCl₂per 100 kg of mixture. Group 3 without administration of additional Ni or Zn served as control. After the 90-day experimental period, femoral length, femoral weight and histological structure of the femur were analyzed and compared.</p> <p>Results</p> <p>The results did not indicate a statistically significant difference in either femoral length or weight between the two experimental groups and the control group. Also, differences in qualitative histological characteristics of the femora among rabbits from the three groups were absent, except for a fewer number of secondary osteons found in the animals of groups 1 and 2. However, values for vascular canal parameters of primary osteons were significantly lower in group 1 than in the control one. Peroral administration of a combination of Ni and Zn (group 2) led to a significant decreased size of the secondary osteons.</p> <p>Conclusions</p> <p>The study indicates that dietary supplementation of Ni (35 g NiCl₂per 100 kg of feed mixture) and Ni-Zn combination (35 g NiCl₂and 30 g ZnCl₂per 100 kg of the mixture) affects the microstructure of compact bone tissue in young rabbits.</p

Carcinoma Matrix Controls Resistance to Cisplatin through Talin Regulation of NF-kB

Extracellular matrix factors within the tumor microenvironment that control resistance to chemotherapeutics are poorly understood. This study focused on understanding matrix adhesion pathways that control the oral carcinoma response to cisplatin. Our studies revealed that adhesion of HN12 and JHU012 oral carcinomas to carcinoma matrix supported tumor cell proliferation in response to treatment with cisplatin. Proliferation in response to 30 µM cisplatin was not observed in HN12 cells adherent to other purified extracellular matrices such as Matrigel, collagen I, fibronectin or laminin I. Integrin β1 was important for adhesion to carcinoma matrix to trigger proliferation after treatment with cisplatin. Disruption of talin expression in HN12 cells adherent to carcinoma matrix increased cisplatin induced proliferation. Pharmacological inhibitors were used to determine signaling events required for talin deficiency to regulate cisplatin induced proliferation. Pharmacological inhibition of NF-kB reduced proliferation of talin-deficient HN12 cells treated with 30 µM cisplatin. Nuclear NF-kB activity was assayed in HN12 cells using a luciferase reporter of NF-kB transcriptional activity. Nuclear NF-kB activity was similar in HN12 cells adherent to carcinoma matrix and collagen I when treated with vehicle DMSO. Following treatment with 30 µM cisplatin, NF-kB activity is maintained in cells adherent to carcinoma matrix whereas NF-kB activity is reduced in collagen I adherent cells. Expression of talin was sufficient to trigger proliferation of HN12 cells adherent to collagen I following treatment with 1 and 30 µM cisplatin. Talin overexpression was sufficient to trigger NF-kB activity following treatment with cisplatin in carcinoma matrix adherent HN12 cells in a process disrupted by FAK siRNA. Thus, adhesions within the carcinoma matrix create a matrix environment in which exposure to cisplatin induces proliferation through the function of integrin β1, talin and FAK pathways that regulate NF-kB nuclear activity

A New Modification of Photometric Method

For the digital 1D-image processing we go out from the so-called photometric method. For the concrete applications of the introduced method its accuracy lowers, owing to that the form of an output video signal of linear CCD sensor is not smooth and not symmetrical. In some cases the output video signal of linear CCD sensor is devalued by the certain disperse of pixel sensitivity, respectively also that a measured object and its background are not uniform. Therefore we introduce a new modification of photometric method. The obtained results show, that introduced method gives a possibility to raise the measurement accuracy of the object dimension considerably

System for Digital 1D-Image Processing with 1024 Pixel CCD Sensor

The conception of system for digital 1D-images processing with digital CCD camera is presented. The system is created from these three basic parts: the digital CCD camera with linear image sensor CCD L133C, 8-bit interface and a personal computer. The scanning digital CCD camera generated a video signals, which are processed in the analog signal processor. The output signal is continually converted to 8-bit data words in A/D converter. This data words maybe transfer over a bus driver to the operation memory of personal computer, by setting one of the three work regimes of digital CCD camera. Some application possibilities and basic technical parameters of this system are given