Comparison of benthic diatom community structures on natural and artificial substrates in marine lake (Adriatic Sea)

In this study, the diatoms of three alternative habitats (epilithon, epiphyton and artificial sub-strate) were compared to understand the differences in composition on artificial and natural sub-strates. For this purpose, the samples were collected weekly between 11th August and 2nd Septem-ber 2016 at a sampling site in a shallow marine lake, Mrtvo More (Dead Sea) on Lokrum Island near Dubrovnik (South Adriatic, Croatia). In addition to detailed light microscopic analysis, ultrastructural analysis of benthic diatoms from Lake Mrtvo More was performed for the first time using scanning electron microscopy (SEM). A total of 97 taxa were identified in 12 samples. Cocconeis scutellum Ehrenberg and Halamphora coffeiformis (C.Agardh) Levkov were the most frequent taxa in the samples. Shannon-Wiener diver-sity index (H’) values varied from 1.78 (in September on Padina sp.) to 4.52 (in August on glass). According to non-metric multidimensional scaling ordination, there were two groups: epilithon and artificial glass substrate as Group1 and macroalgae as Group2. The results of the analysis showed that the diatom communities developing on artificial sub-strates accurately correspond to the diatom community of a rock substrate and thus can be used as a representative alternative tool for studies of epilithic diatoms in further experiments.

Correlation of histopathology of trabecular meshwork with clinical features in primary congenital glaucoma

PurposeTo correlate histopathological changes of trabecular meshwork (TM) with clinical features in primary congenital glaucoma (PCG).MethodsThis was a prospective interventional study including 66 eyes of 39 PCG children aged ≤12 months at diagnosis. Corneal clarity, corneal diameter (CD), intraocular pressure (IOP) and cup disc ratio (C:D ratio) were assessed at baseline and at 1-year follow-up. The trabecular meshwork (TM) specimens obtained during primary combined trabeculectomy and trabeculotomy augmented with Mitomycin-C were evaluated on light microscopy to look for eosinophilic membrane (EM), status of trabecular beams and trabecular endothelial cells (TEC), presence of intervening spaces, TM thickness and TEC count which were then correlated with clinical features.ResultsAt 1-year follow-up, IOP reduced from 27.96±10.2 to 11.88±5.63 mm Hg, p<0.001, C:D ratio decreased from 0.65±0.34 to 0.49±0.06, p=0.036, and the bleb had a significant tendency to change from well formed (59–46) to flat type (3–6) or thin, cystic type (4–14) (p=0.014). Presence of EM on the cameral surface was associated with a lower baseline IOP. Fused trabecular beams were associated with higher baseline IOP. The TM was significantly thicker in eyes with IOP >20 mm Hg at presentation (1.86±0.7 mm vs 1.3±0.47 mm, p=0.0356). Eyes with IOP ≤14 mm Hg at final follow-up had lower TEC count than eyes with IOP >14 mm Hg (0.92±0.45 cells/mm2 vs 1.00±0.74 cells/mm2, p=0.0028).ConclusionA light microscopic analysis of surgical specimens may guide prognosis of PCG. However, larger studies are required to validate these results.

Additional study of the morphology of eggs and miracidia of Eurytrema coelomaticum (Trematoda)

The morphology of the eggs and miracidia of Eurytrema coelomaticum was analyzed. The eggshell presented different composition according to the maturation stage of the egg, as seen by distinct birefringence after polarized light microscopic analysis. Detailed morphology of the brownish eggs, measuring 44.97±3.83 (38.67 - 51.40) μm in length and 30.71±2.54 (25.79 -34.47) μm in width, and the different electrondensities of the inner, middle and outer layers of the eggs were determined using light (bright field and DIC) and electronic microscopy (scanning and transmission). The morphometry of the eggs is in accordance to those measures presented in previous studies. The miracidia were observed using light microscopy, inside and outside the egg. It was possible to observe the terebratorium at the anterior end of the body, the ciliated epidermal plates, placed according the formula E=2E1 + 2E2, and the interepidermal ridge, but eyespots were not observed. The excretory vesicle was laterally placed in the posterior middle of the body and the germ balls were observed. The miracidium inside the egg was observed by routine techniques, but the miracidium was not well preserved. Thus, the eggs were processed using high pressure-freeze substitution technique and reasonable preservation was achieved. The cilia covering the larval body, with a typical ciliary organization, the terebratorium with folds and the junction of the epidermal ciliated cell with the larval body were seen. For the first time detailed information on the eggs and miracidia of E. coelomaticum is given, which can be the basis for new studies.

Insight into behavior of epithelial cells of the feline conjunctiva in chronic conjunctivitis as a possible limitation in detection of Chlamydophila spp.

The aims of this work was documentation of the reactivity of feline conjunctival epithelial cells in chronic conjunctivitis and the investigation of a possible correlation of histological findings in conjunctiva with a limitation in detection of the pathogen. In this observational study, conjunctival swab samples collected from six cats suffering from chronic conjunctivitis were monitored for Chlamydophila spp. infection for one month, every ten days. Chlamydophilosis was diagnosed by conventional PCR, and confirmed by sequencing analysis. A lack of coherence with results in subsequent studies using PCR did not allow an accurate diagnosis. Additional bioptat samples of conjunctiva were collected for diagnostic purposes and stained in haematoxylin and eosin following the Giemsa method for light microscopic analysis. Additionally the samples were incubated for 15 min with IMAGENTM Chlamydia conjugate (IMAGENTM Chlamydia reagent kit, Dako, UK), allowing immunofluorescence detection of Chlamydophila spp. Within the epithelium an increased number of goblet cells, as well as general enlargement of the epithelium and a reduced number of normal epithelial cells, was observed. Only in areas of low epithelium could structures similar to the elementary bodies of Chlamydophila spp. be distinguished. The presented data document a possible limitation in molecular evidence for chlamydophila infection in some naturally infected cats, taking into account histological conditions in conjunctiva at the same time.