Use Of Microscopic Methods Research Articles

Molecular and Serological Survey for Toxoplasmosis in Cats from an urban populations in Egypt

Cats were the key species in the epidemiology of Toxoplasma gondii infection, even if the proportion of subjects excreting oocysts is low. Two hundred and forty cats; 84 stray cats and 156 household cats brought to the Animal Reproductive Research Institute(ARRI) laboratory from different Governorates in Egypt in the period from January 2017 to July 2018. All cats were examined for oocysts of T. gondii in fecal samples and T. gondii antibodies in serum samples. In our study, the results of microscopic examination revealed that (35.71%) of T. gondii oocysts of cats in different governorates. The rate of this infection was (45.71%) in stray cats; highest positivity revealed in Menoufia Governorate (46.67%) and the lowest rate represented in Red sea Governorate(42.86%). On the other side, the lowest positive rate of fecal samples was (25.71%) in household cats; highest positivity in Menoufia Governorate (30%) and lowest rate in Red sea (12.5%). On site Toxoplasma Rapid test; IgM were (34%) the seropositivity infection 35% in stray cats and 33.33% in household cats, indicating a recent infection. IgG were 54% the seropositivity 55% in stray cats and 53.33% in household cats respectively. Results suggest that the use of microscopical methods plus PCR in feces may be the best of choice for diagnosis of feline toxoplasmosis, as it can be expected to improve the value of diagnosis procedures determining if cats are currently shedding oocysts. Detection of T. gondii using serological methods and facilitates diagnosis by On Site Rapid Test protecting citizens against the T. gondii infection from infected cats. Finally, we concluded that a key to effective management of toxoplasmosis is prompt and accurate diagnosis of disease. Stray cats probably the major source of T. gondii infection. The prevalence rate of toxoplasmosis in cats is high and this can be considered a potential danger to public health and animals due to high contamination of the environment by oocysts. Some control measures are suggested based on these findings.

Determining the occurrence of the Uncinaria stenocephala and Ancylostoma caninum nematode invasion in dogs in Poland, with special emphasis on the Lublin region

Apart from roundworms, Ancylostomatidae nematodes are presently the most frequently observed nematodes in dogs in Poland, with two species described so far: Uncinaria stenocephala and Ancylostoma caninum. The study aimed to determine the hookworm species found in dogs in Poland, with special emphasis on the Lublin region. The study material consisted of fecal samples collected from 500 dogs from the area of the Lublin voivodeship. With the use of microscope methods, parasite eggs were found in 56.4% of the samples, dominated by the Ancyclostomidae nematode (26.8%). The isolated hookworm eggs were subject to morphometric measurements, giving a mean length of 77.60 μm and width of 44.25 μm (±SD ±6.01 and ±4.54 respectively) within the range 67-91 × 36-56 μm. The hookworm larvae that hatched from the samples were subject to molecular analysis (72 samples) and all were identified as U. stenocephala. In the area of the Lublin voivodeship U. stenocephala is the dominant hookworm species in dogs.

Female sporogenesis in the native Antarctic grass Deschampsia antarctica Desv.

Abstract The development of megasporocytes and the functional megaspore formation in Deschampsia antarctica were analyzed with the use of microscopic methods. A single archesporial cell was formed directly under the epidermis in the micropylar region of the ovule without producing a parietal cell. In successive stages of development, the meiocyte was transformed into a megaspore tetrad after meiosis. Most megaspores were arranged in a linear fashion, but some tetrads were T-shaped. Only one of the 60 analyzed ovules contained a cell in the direct proximity of the megasporocyte, which could be an aposporous initial. Most of the evaluated D. antarctica ovules featured monosporic embryo sacs of the Polygonum type. Approximately 30% of ovules contained numerous megaspores that were enlarged. The megaspores were located at chalazal and micropylar poles, and some ovules featured two megaspores – terminal and medial – in the chalazal region, or even three megaspores at the chalazal pole. In those cases, the micropylar megaspore was significantly smaller than the remaining megaspores, and it did not have the characteristic features of functional megaspores. Meiocytes and megaspores of D. antarctica contained polysaccharides that were detectable by PAS-reaction and aniline blue staining. Starch granules and cell walls of megasporocytes, megaspores and nucellar cells were PAS-positive. Fluorescent callose deposits were identified in the micropylar end of the megasporocytes. During meiosis and after its completion, thick callose deposits were also visible in the periclinal walls and in a small amount in the anticlinal walls of megaspores forming linear and T-shaped tetrads. Callose deposits fluorescence was not observed in the walls of the nucellar cells.

Intra- and inter-observer variation in histological criteria used in age at death determination based on femoral cortical bone

The microscopic method of age at death determination was introduced by Kerley in 1965. The method, which relies on the quantification of selected elements in cortical bone tissue, has been widely used, and several other researchers have modified or added to the method. Yet, very few studies have been carried out dealing with the intra- and inter-observer error. Furthermore, when such studies have been completed, the statistical tools for assessing variability have not been adequate. This study presents the results of applying simple quantitative statistics on several counts of microscopic elements as observed on photographic images of cortical bone, in order to assess intra- and inter-observer error. Overall, substantial error was present at the level of identifying and counting secondary osteons, osteon fragments and Haversian canals. Only secondary osteons can be reliably identified, precluding the use of osteon fragments and Haversian canals. The observers in this study included experienced and inexperienced users of the microscopic method, yet the variability was uniformly large for all observers, suggesting fundamental problems in definition and identification of the structural elements. Until more rigorous definitions of such elements have been agreed upon, the use of microscopical methods must be discouraged as a sole or uncontrolled method of evaluating age at death.

Intra- and inter-observer variation in histological criteria used in age at death determination based on femoral cortical bone

The microscopic method of age at death determination was introduced by Kerley in 1965. The method, which relies on the quantification of selected elements in cortical bone tissue, has been widely used, and several other researchers have modified or added to the method. Yet, very few studies have been carried out dealing with the intra- and inter-observer error. Furthermore, when such studies have been completed, the statistical tools for assessing variability have not been adequate. This study presents the results of applying simple quantitative statistics on several counts of microscopic elements as observed on photographic images of cortical bone, in order to assess intra- and inter-observer error. Overall, substantial error was present at the level of identifying and counting secondary osteons, osteon fragments and Haversian canals. Only secondary osteons can be reliably identified, precluding the use of osteon fragments and Haversian canals. The observers in this study included experienced and inexperienced users of the microscopic method, yet the variability was uniformly large for all observers, suggesting fundamental problems in definition and identification of the structural elements. Until more rigorous definitions of such elements have been agreed upon, the use of microscopical methods must be discouraged as a sole or uncontrolled method of evaluating age at death.

Use of microscopic methods for estimation of phase morphology in rubber/polyolefin blends

The etching efficiency of several solvents and oxidizing agents for analysis of phase morphology of two different blend systems has been examined. Whilst toluene etches PRP/EVA copolymers independently of blend composition, potassium permanganate (KMnO 4) has been found to be effective only for higher EVA concentrations. In NR/LDPE blends, although hot xylene effectively etches sulphur-cured compositions, for peroxide-cured systems where both the two phases are crosslinked, only a 2% KMnO 4 solution in mixed acid could yield good results. The effectiveness of the etching systems was documented by microscopic methods and the efficiency of selective etching agents was confirmed by estimating and comparing the volume fraction of the dispersed phase by a stereological method.

The refractive index and dry mass distribution of mammalian erythrocytes

SUMMARYQuantitative microscopical methods are now of outstanding importance in the diagnosis and assessment of mammalian red blood cells.After release from the erythropoetic organs, all red blood cells in the peripheral blood of mammals pass through the reticulocyte stage before becoming mature erythrocytes. Therefore, the determination of reticulocyte number is used as an index of erythropoetic activity in clinical hæmatology.The corpuscular solid concentration, the corpuscular dry weight, the osmotic resistance and the size of red blood cells can be determined by use of microscopical methods. For the determination of the corpuscular solid concentration of erythrocytes, cell refractometry by the use of phase‐contrast microscopy has proved to be a very sensitive and accurate method. The dry weight of single erythrocytes may likewise be obtained by the use of interference microscopy with relatively high accuracy. Both of these methods might also be of use in clinical hæmatology.In the experimental work described in this paper, both methods mentioned above are used to answer the question: whether and under what conditions the refractive index as a criterion of measurement of the solid concentration and the relative dry weight can be determined separately for reticulocytes and erythrocytes from the same blood sample by use of microscopical methods alone. The frequency distributions of refractive indices and relative dry weights determined on human reticulocytes and mature erythrocytes show significantly lower mean values for the reticulocyte generation in accordant with findings published by other authors and obtained by use of sometimes entirely different methods. The additional information gained by the determination of the frequency distribution of refractive index and dry weight of reticulocytes and mature erythrocytes separately in a blood sample and the necessity for simplifying and automating such methods for hæmatological diagnosis are discussed.