Effects of tumors on the daily mitotic activity of mouse pars intermedia

We have investigated the effects of EA21a and EA34 mammary carcinomas on daily PI cell proliferation in mice. Animals were divided into groups grafted with either EA34 or EA21a carcinomas (and a non-grafted control group). They were all injected intraperitoneally with 2 microg colchicine per g of body weight 4 h before sacrifice and the number of mitoses per 1000 nuclei was calculated. The mitotic index (MI) of pars-intermedia epithelial cells in control animals showed significant temporal variations. However, the MI from mice grafted with EA34 or EA21a carcinomas showed no such variation. There was no difference between the daily MIs of controls and tumor grafted groups. The absence of a 24 h mitotic activity curve in both EA21a and EA34 tumor-bearing animals demonstrates a lower level of synchronization of cells entering mitosis.     

Effects of soy oil on murine salivary tumorigenesis

Dietary fat influences dimethylbenzanthracene (DMBA)-induced tumorigenesis of several organs, including the salivary glands. There is not enough evidence to suggest that soy oil could also affect growth of salivary tumors. The main purpose of this work therefore was to study the effects of dietary soy oil on macroscopic parameters of chemically induced murine salivary gland tumors. Eighty BALB/c male mice were assigned to four groups: soy oil (SO), corn oil (CO, control), fish oil (FO) and olein (O). Two weeks later, tumors were induced by 9,10-dimethyl-1,2-benzanthracene (DMBA). At the 13th post-injection week, the animals were sacrificed. In vivo tumor diameter, gland volume (total resected mass), tumor volume (microscopically measured), tumor remission and tumor histopathology were analyzed. The initial in vivo tumor diameter, gland and tumor volume were significantly greater in soy oil than in fish oil group. 26.7% of animals on the soy oil diet showed tumor remission. Sarcomas were more often found in the SO group, carcinomas in FO and the mixed-type tumors both in SO and CO groups. This study shows that the soy oil treatment resulted in larger tumors, some of which later became undetectable. It is necessary to further investigate these divergent results.     

Cataract surgery and postoperative complications in diabetic patients

Diabetes mellitus influences the function and morphology of the eye lens. The cataract is the second most common complication of diabetes mellitus on the eye. A hundred patients with cataract were examined in the prospective study. The patients were divided into two groups. The first group consisted of 50 patients with cataract who had not suffered from a system or local disease. The second group consisted of 50 patients with cataract and diabetes mellitus that had lasted for at least five years. In both groups the patients underwent identical cataract extra capsular extraction with intraocular PMMA (polymethylmethacrylate) lens implantation in camera posterior. The objective of this study was to compare the two groups of patients in order to find out the most common intraoperative or postoperative complications in diabetics. The most common postoperative complications in patients suffering from diabetes were inflammatory reactions and bleeding: postoperative keratopathy, uveitis anterior serous and uveitis anterior fibrinous with posterior sinechia and opacity of the posterior lens capsule as results. Postoperative visual acuity was worse in the patients in group II on the seventh day and six months after operation. It was diabetic retinopathy and its progression that caused deterioration of visual acuity. Diabetic retinopathy and its progression, as well as maculopathy were found only in patients who were not treated with photocoagulation before the operation.     

Sequence similarity-based proteomics in insects: characterization of the larvae venom of the Brazilian moth Cerodirphia speciosa

Using a combination of tandem mass spectrometric sequencing and sequence similarity searches, we characterized the larvae venom of the moth Cerodirphia speciosa, which belongs to the Saturniidae family of the Lepidoptera order. Despite the paucity of available database sequence resources, the approach enabled us to identify 48 out of 58 attempted spots on its two-dimensional gel electrophoresis map, which represented 37 unique proteins, whereas it was only possible to identify 13 proteins by conventional non-error tolerant database searching methods. The majority of cross-species hits were made to proteins from the phylogenetically related Lepidoptera organism, the silk worm Bombyx mori. The protein composition of the venom suggested that envenoming by C. speciosa toxins might proceed through the contact with its hemolymph, similarly to another toxic Lepidoptera organism, Lonomia obliqua.     

Early and natural embryonic death in Lagostomus maximus: Association with the uterine glands,vasculature, and musculature

The uterus is an organ with great plasticity due to the morphological and physiological changes it experiences during the estrous cycle and pregnancy. In mammals, pregnancy requires diverse sex hormones, growth factors and cytokines, among others, for promoting uterine remodeling to favor implantation, placentation, and embryo/fetus survival and growth. The hystricognathi rodent Lagostomus maximus (plains viscacha) has a high rate of embryonic resorption. The cranial and middle implants are reabsorbed 25–35 days after intercourse while the caudal embryos continue with their development until two precocial offspring are born. So far, no uterine studies of non-pregnant L. maximus females were performed to determine the possible existence of variations in the organ that could be related to the differential survival of the implants. We used ultrasonography, as well as morphological, morphometric, histochemical, lectinhistochemical, and immunohistochemical methods to study differences in the uterine glands (area), vasculature (area), and musculature (thickness) along the uterine horns in non-pregnant females. Along the uterus, all these structures were in more advanced developmental condition in the caudal region as compared to more anterior positions. These regional variations could be decisive in explaining the reason why only caudal implantations come to term. In contrast, no differences in the in the luminal and glandular epithelial cells, nor in the degree of cell proliferation and apoptosis, and hormonal receptor staining were found. These parameters could be related to implantation along the uterine horns, but not to the differential survival of the implants.     

The h-Current in Periglomerular Dopaminergic Neurons of the Mouse Olfactory Bulb

The properties of the hyperpolarization-activated cation current (I_h) were investigated in rat periglomerular dopaminergic neurons using patch-clamp recordings in thin slices. A reliable identification of single dopaminergic neurons was made possible by use of a transgenic line of mice expressing eGFP under the tyrosine hydroxylase promoter. At 37 °C and minimizing the disturbance of the intracellular milieu with perforated patches, this current shows a midpoint of activation around −82.7 mV, with a significant level of opening already at rest, thereby giving a substantial contribution to the resting potential, and ultimately playing a relevant function in the control of the cell excitability. The blockage of I_h has a profound influence on the spontaneous firing of these neurons, which result as strongly depressed. However the effect is not due to a direct role of the current in the pacemaker process, but to the I_h influence on the resting membrane potential. I_h kinetics is sensitive to the intracellular levels of cAMP, whose increase promotes a shift of the activation curve towards more positive potentials. The direct application of DA and 5-HT neurotransmitters, physiologically released onto bulbar dopaminergic neurons and known to act on metabotropic receptors coupled to the cAMP pathway, do not modifythe I_h amplitude. On the contrary, noradrenaline almost halves the I_h amplitude. Our data indicate that the HCN channels do not participate directly to the pacemaker activity of periglomerular dopaminergic neurons, but influence their resting membrane potential by controlling the excitability profile of these cells, and possibly affecting the processing of sensory information taking place at the entry of the bulbar circuitry.     

Effect of the endosymbiotic pea crab Calyptraeotheres garthi on the metabolic rate and oxidative status of the slipper limpet Crepidula cachimilla

Parasites may induce metabolic changes and imbalances in the redox status of hosts. This study tested the effect of parasites on the O₂ consumption rate (O₂‐CR) of hosts, and explored the link between O₂‐CR and oxidative stress in parasitized hosts. We used the symbiotic pea crab Calyptraeotheres garthi and its slipper limpet host Crepidula cachimilla as models. The O₂‐CR of long‐term (3 months) infested limpets was 2.5 times greater than that of long‐term uninfested limpets. Also, the O₂‐CR of limpets stripped of crabs 24 h before measurements was intermediate between that of long‐term infested and uninfested limpets. These results indicate a parasitic relationship between C. garthi and Cr. cachimilla, and suggest that the effect of the parasite on the metabolic rate of limpets is reversible. Lastly, the activity of two antioxidant enzymes (CAT and GST) as well as lipid peroxidation did not vary between infested and uninfested limpets. Thus, increased O₂‐CR is not necessarily coupled with oxidative stress in pea crab‐parasitized slipper limpets.     

Updated checklist of the mosquitoes (Diptera: Culicidae) of Croatia

Improvement of morphological and molecular identification methods allows the detection of new species of mosquitoes. The mosquito fauna of Croatia currently includes 52 species, belonging to eight genera, including Anopheles (12 species), Aedes (24 species), Coquillettidia (one species), Culex (seven species), Culiseta (six species), Orthopodomyia (one species), and Uranotaenia (one species). This is an updated checklist, which includes five new species found in Croatian mosquito fauna. Two of these are invasive mosquito species, Aedes albopictus (Skuse, 1895) and Aedes japonicus (Theobald 1901), which are spreading across Europe and Croatia. The other three species, Culex laticinctus (Edwards 1913), Culex torrentium (Martini 1925), and Anopheles daciae (Linton, Nicolescu & Harbach 2004) are autochthonous species which haven't been recorded so far. Since there are several more invasive species spreading across Europe, we assume that this is not the final list.