Temporal and structural sensitivities of major biomarkers for detecting neuropathology after traumatic brain injury in the mouse

Traumatic brain injury (TBI) is a leading cause of morbidity and mortality, especially in teenagers to young adults. In recent decades, different biomarkers and/or staining protocols have been employed to evaluate the post-injury development of pathological structures, but they have produced many contradictory findings. Since correctly identifying the underlying neuroanatomical changes is critical to advancing TBI research, we compared three commonly used markers for their ability to detect TBI pathological structures: Fluoro-Jade C, the rabbit monoclonal antibody Y188 against amyloid precursor protein and the NeuroSilver kit were used to stain adjacent slices from naïve or injured mouse brains harvested at different time points from 30 min to 3 months after lateral fluid percussion injury. Although not all pathological structures were stained by all markers at all time points, we found damaged neurons and deformed dendrites in gray matter, punctate and perivascular structures in white matter, and axonal blebs and Wallerian degeneration in both gray and white matter. The present study demonstrates the temporal and structural sensitivities of the three biomarkers: each marker is highly effective for a set of pathological structures, each of which in turn emerges at a particular time point. Furthermore, the different biomarkers showed different abilities at detecting identical types of pathological structures. In contrast to previous studies that have used a single biomarker at a single time range, the present report strongly recommends that a combination of different biomarkers should be adopted and different time points need to be checked when assessing neuropathology after TBI.

Modification of Grocott's staining procedure with heat treatment and oxidation by periodic acid for mucormycosis in tissue: a method to detect Mucor spp

The sensitivity of the Grocott-modified Gomori's methenamine-silver nitrate technique for the detection of fungi is sometimes low, especially for Mucor spp. We modified the Grocott technique by replacing chromic acid with periodic acid in the oxidation step. The use of periodic acid instead of chromic acid enhanced the detectability of Mucor spp. in histopathological sections. Other parameters should be assessed with a high number of cases under different conditions. We propose our protocol as one of the options in practice, especially in cases suspected of Mucor spp. infection.

Structure and Methylation of 35S rDNA in Allopolyploids Anemone multifida (2n = 4x = 32, BBDD) and Anemone baldensis (2n = 6x = 48, AABBDD) and Their Parental Species Show Evidence of Nucleolar Dominance

Transcriptional silencing of 35S rDNA loci inherited from one parental species is occurring relatively frequently in allopolyploids. However, molecular mechanisms by which it is selected for transcriptional silencing remain unclear. We applied NGS, silver staining and bisulfite sequencing to study the structure, expression and methylation landscape of 35S rDNA in two allopolyploids of common origin, allotetraploid Anemone multifida (2n = 4x = 32, genome composition BBDD) and allohexaploid A. baldensis (2n = 6x = 48, AABBDD), and their genome donors, A. sylvestris (2n = 16, AA), A. cylindrica (2n = 16, BB) and A. parviflora (2n = 16, DD). The size of the recovered 35S rDNA units varied from 10,489 bp in A. cylindrica to 12,084 bp in A. sylvestris. Anemone showed an organization typical of most ribosomal 35S rDNA composed of NTS, ETS, rRNA genes, TTS and TIS with structural features of plant IGS sequences and all functional elements needed for rRNA gene activity. The NTS was more variable than the ETS and consisted of SRs which are highly variable among Anemone. Five to six CpG-rich islands were found within the ETS. CpG island located adjacent to the transcription initiation site (TIS) was highly variable regarding the sequence size and methylation level and exhibited in most of the species lower levels of methylation than CpG islands located adjacent to the 18S rRNA gene. Our results uncover hypomethylation of A. sylvestris- and A. parviflora-derived 35S rDNA units in allopolyploids A. multifida and A. baldensis. Hypomethylation of A. parviflora-derived 35S rDNA was more prominent in A. baldensis than in A. multifida. We showed that A. baldensis underwent coupled A. sylvestris-derived 35S rDNA array expansion and A. parviflora-derived 35S rDNA copy number decrease that was accompanied by lower methylation level of A. sylvestris-derived 35S rDNA units in comparison to A. parviflora-derived 35S rDNA units. These observations suggest that in A. baldensis nucleolar dominance is directed toward A. sylvestris-derived chromosomes. This work broadens our current knowledge of the 35S rDNA organization in Anemone and provides evidence of the progenitor-specific 35S rDNA methylation in nucleolar dominance.

Whole-organism 3D quantitative characterization of zebrafish melanin by silver deposition micro-CT

We previously described X-ray histotomography, a high-resolution, non-destructive form of X-ray microtomography (micro-CT) imaging customized for three-dimensional (3D), digital histology, allowing quantitative, volumetric tissue and organismal phenotyping (Ding et al., 2019). Here, we have combined micro-CT with a novel application of ionic silver staining to characterize melanin distribution in whole zebrafish larvae. The resulting images enabled whole-body, computational analyses of regional melanin content and morphology. Normalized micro-CT reconstructions of silver-stained fish consistently reproduced pigment patterns seen by light microscopy, and further allowed direct quantitative comparisons of melanin content across wild-type and mutant samples, including subtle phenotypes not previously noticed. Silver staining of melanin for micro-CT provides proof-of-principle for whole-body, 3D computational phenomic analysis of a specific cell type at cellular resolution, with potential applications in other model organisms and melanocytic neoplasms. Advances such as this in whole-organism, high-resolution phenotyping provide superior context for studying the phenotypic effects of genetic, disease, and environmental variables.

Lynnia grapsolytica n. gen, n. sp. (Ciliophora: Apostomatida: Colliniidae), a Deadly Blood Parasite of Crabs with a Novel Pseudocytopharynx

We describe a new genus and species of blood-dwelling apostome ciliate, Lynnia grapsolytica n. gen., n. sp. (Apostomatida: Colliniidae). A distinct kinety "hook" pattern on the tomite's posterior ventral face, coupled with its marine habitat and use of a decapod host, readily distinguishes this ciliate from all known colliniids. We detected the parasite in ~12% of Pachygrapsus crassipes (Brachyura: Grapsidae) crabs in a California estuary and confirmed its presence at a Baja California rocky intertidal site. As existing methods failed to adequately stain this ciliate, we developed a new miniaturized silver carbonate impregnation staining method that produced excellent somatic and nuclear stains in all five observed cell types. A possibly unique trait is the active invagination of the tropho-tomont's anterior to form a temporary "pseudocytopharynx," likely used for feeding. Histological examination revealed that the ciliate invaded and damaged skeletal muscle, the heart, connective tissues, and gonads. Survivorship analysis indicated that infected crabs experienced 2.6 times greater daily mortality than uninfected crabs. Laboratory and field experimental infection attempts failed, suggesting a complex life cycle with outside-host development. Phylogenetic analysis at the 18S and COI loci confirmed the ciliate's placement in the Colliniidae. We emend the diagnosis of Family Colliniidae.

Quantitative Neurotoxicology: An Assessment of the Neurotoxic Profile of Kainic Acid in Sprague Dawley Rats

This study consisted of a qualitative and quantitative assessment of neuropathological changes in kainic acid (KA)-treated adult male rats. Rats were administered a single 10 mg/kg intraperitoneal injection of KA or the same volume of saline and sacrificed 24 or 48 hours posttreatment. Brains were collected, sectioned coronally (∼ 81 slices), and stained with amino cupric silver to reveal degenerative changes. For qualitative assessment of neural degeneration, sectioned material was evaluated by a board-certified pathologist, and the level of degeneration was graded based upon a 4-point scale. For measurement of quantitative neural degeneration in response to KA treatment, the HALO digital image analysis software tool was used. Quantitative measurements of specific regions within the brain were obtained from silver-stained tissue sections with quantitation based on stain color and optical density. This quantitative evaluation method identified degeneration primarily in the cerebral cortex, septal nuclei, amygdala, olfactory bulb, hippocampus, thalamus, and hypothalamus. The KA-produced neuronal degeneration in the cortex was primarily in the piriform, insular, rhinal, and cingulate areas. In the hippocampus, the dentate gyrus was found to be the most affected area. Our findings indicate global neurotoxicity due to KA treatment. Certain brain structures exhibited more degeneration than others, reflecting differential sensitivity or vulnerability of neurons to KA.

Bovine digital dermatitis in Victoria, Australia

AIMS

The objectives of this study were to estimate the prevalence of digital dermatitis (DD) in Victoria, Australia, and to investigate which organisms are consistent with typical DD lesions. The prevalence and causative pathogens of DD are not clear yet in Australia and this paper is one of the first to explore these questions in this country.

METHODS

Examination and sampling of limbs was undertaken at three knackeries in Victoria, Australia. Limbs were classified as normal (N), active DD-lesion (A), dried or chronic DD-lesion (D) or suspected case of DD (S). A total of 823 cows were examined. Six skin biopsies were taken at each knackery, from which DNA was extracted for diversity profiling. Histochemical staining of samples was performed on eight of the skin biopsies.

RESULTS

DD was detected in 29.8% of all cows. The prevalence of DD was significantly higher in dairy cows (32.2%) than in beef cows (10.8%). The differential abundance of Treponema-species was significantly increased in dried lesions, compared with the normal skin biopsies. Actinobacteria, Proteobacteria, Firmicutes and Tenericutes were found to be significantly different in abundance in the DD lesions compared with normal skin biopsies. Silver staining of samples showed only mild inflammation and in two samples organisms with morphology consistent with Spirochaetes were detected.

CONCLUSIONS

The calculated prevalence indicates that DD is present in Victoria, Australia. The results of diversity profiling showed that the presence of Treponema-species was significantly different between the samples of DD lesions and normal skin.

Nucleolar organizer region banding in crossbred and non-descript pigs of India

Aim:

The objective of this experiment was to study the nucleolar organizer region (NOR)-banding pattern in Large White Yorkshire (LWY) crossbred and non-descript pigs and finding differences in the number of NORs between animals and between genetic groups.

Materials and Methods:

The experiment was carried out on 15 females, and 15 males of LWY crossbred and non-descript pigs to study NOR-banding pattern by employing ammoniacal silver staining technique.

Results:

A total of 63 and 65 number of good metaphases were prepared in LWY crossbred, and non-descript pigs and a total of 168 and 143 number of NORs were detected on the 8th and 10th chromosomes in both genetic groups, respectively. The mean number of NORs per metaphase was 2.67 and 2.20 in LWY crossbred and non-descript pigs, respectively. LWY crossbred pig had high mean number of silver-stained NORs (Ag-NORs) per metaphase compared to non-descript pig. In general, it was observed that the highest frequency of metaphases (%) examined had two number of NORs, while the lowest frequency (%) had four number of NORs. The number of NORs observed per metaphase on secondary constrictions of the 8th and 10th chromosome pair in both genetic groups ranged from 2 to 4. The Chi-square test of significance revealed that the observed frequencies do not differ significantly from the expected frequencies.

Conclusion:

The results confirmed differences across breeds in occurrence and number of NORs on chromosomes in pigs. The mean numbers of NORs present per metaphase vary between the animals indicating the existence of polymorphism for the number of NORs. A higher number of Ag-NORs were observed on chromosome pair 10 in both the genetic groups. It was concluded that NORs were more morphologically distinct and greater on chromosome pair 10 than on pair 8, which suggests a dominant role of chromosome 10 in the global production of ribosomal RNA.

Upstream Hedgehog signaling components are exported in exosomes of cervical cancer cell lines

AIM

To investigate export of Hedgehog pathway (Hh) proteins Patched1, Smoothened, Sonic hedgehog and Indian hedgehog in cervical cancer cell line (CaCx) exosomes.

METHODS

Exosomes were isolated and characterized by Western blotting, scanning electron microscopy and in a colorimetric assay. Nucleic acids (RNA, DNA) and protein content of exosomes were analyzed. Hh pathway proteins in exosomes were detected using Western blotting.

RESULTS

CaCx secrete bio-macromolecule (DNA, RNA and proteins) enriched exosomes. CaCx exosomes contained higher amount of RNA with respect to DNA. CaCx preferentially exported Hh proteins (Patched1, Smoothened,  Sonic hedgehog, Indian hedgehog) in their exosomes. Cellular uptake assay revealed rapid internalization of CaCx exosomes in human umbilical vein endothelial cells.

CONCLUSION

Our study showed that Hh proteins are exported in CaCx exosomes.

Cytosolic and Transmembrane Protein Extraction Methods of Breast and Ovarian Cancer Cells: A Comparative Study

Efficient extraction of proteins is a great challenge for numerous downstream proteomic analyses. During the protein extraction procedure, it is critical to maintain the conformational stability, integrity, as well as higher yield of the protein. To do so, 5-different lysis buffers of Tris and HEPES have been used as the primary buffering reagents with variable compositions at different concentrations and pH using human cancer cells. In this study, different protein lysates of human breast cancer cells T47D and MDA-MB-231 and ovarian cancer cell PA-1 were subjected to run SDS-PAGE for separation of proteins based on their molecular size, followed by Coomassie blue, silver staining, and immunoblot assays to compare the extraction yield of total cytoplasmic proteins, glyceraldehyde-3-phosphate dehydrogenase (GAPDH) and the integral membrane protein, integrin β-1. Our results revealed that Tris-based lysis buffer with 50 mM concentration, pH 7.5, is relatively the efficient and reliable protein extraction method for a wide range of MW subcellular markers, cytoplasmic GAPDH and transmembrane integrin β-1 proteins. We anticipate that this simple and cost-effective protein extraction protocol might be extremely useful across a broad range of subcellular proteins in different biologic samples.

Fluorogenic Ag+ -Tetrazolate Aggregation Enables Efficient Fluorescent Biological Silver Staining

Silver staining, which exploits the special bioaffinity and the chromogenic reduction of silver ions, is an indispensable visualization method in biology. It is a most popular method for in-gel protein detection. However, it is limited by run-to-run variability, background staining, inability for protein quantification, and limited compatibility with mass spectroscopic (MS) analysis; limitations that are largely attributed to the tricky chromogenic visualization. Herein, we reported a novel water-soluble fluorogenic Ag+ probe, the sensing mechanism of which is based on an aggregation-induced emission (AIE) process driven by tetrazolate-Ag+ interactions. The fluorogenic sensing can substitute the chromogenic reaction, leading to a new fluorescence silver staining method. This new staining method offers sensitive detection of total proteins in polyacrylamide gels with a broad linear dynamic range and robust operations that rival the silver nitrate stain and the best fluorescent stains.

Analysis of silver binding nucleolar organizer regions in exfoliative cytology smears of potentially malignant and malignant oral lesions

Nucleolar organizer regions are nucleolar components that contain proteins that are stained selectively by silver methods; they can be identified as black dots throughout the nucleolus and are known as silver binding nucleolar organizer regions (AgNOR). The number of AgNOR is related to the cell cycle and the proliferative activity of the cells. We investigated AgNOR using exfoliative cytology smears of potentially malignant oral lesions. Eighty individuals were divided into four equal groups: healthy controls, oral leukoplakia, oral submucous fibrosis and oral squamous cell carcinoma. The mean number of AgNOR in each study group gradually increased from control to oral leukoplakia to oral submucous fibrosis to oral squamous cell carcinoma. The proliferative index was increased in the oral premalignant and malignant patients compared to normal subjects. The mean AgNOR size gradually increased from control to oral leukoplakia to oral submucous fibrosis to oral squamous cell carcinoma. Spherical shaped AgNOR were most common in controls, whereas large, clustered and kidney shapes were most common in oral squamous cell carcinoma. Multiparameter analysis of AgNOR in oral exfoliative smears is a simple, sensitive and cost-effective method for differentiating premalignant from malignant lesions and can be used in conjunction with routine cytomorphological evaluation.

Estimation of argyrophilic nucleolar organizer regions in different grades of oral submucous fibrosis

Context:

Assessment of potential for malignant transformation of oral submucous fibrosis (OSF) through clinical or light microscopic examination of hematoxylin and eosin stained tissue sections is not totally satisfactory. The search is for such a tissue marker that will differentiate those cases of OSF, which carry a higher risk for malignant transformation. During the past few years, numerous workers have validated the usefulness of enumerating argyrophilic nucleolar organizer regions (AgNORs) in predicting the malignant potential of lesions. The present study was carried out to validate the diagnostic potential of this marker.

Objectives of the Study:

Quantitative and qualitative assessment of AgNORs in different grades of OSF and to compare the count of AgNORs in different grades of OSF and normal mucosa.

Materials and Methods:

AgNORs were investigated in tissue specimens from 90 patients diagnosed with different histopathological grades of OSF. AgNORs were identified in tissue specimens stained with silver nitrate, using light microscope. AgNORs were counted as small, large and total count to analyze them both quantitatively and qualitatively.

Statistical Analysis Used:

Results were subjected to statistical analysis for obtaining significance value (P value) by unpaired Student's t-test.

Results:

The mean total count of AgNORs was 2.464 ± 0.101, 4.358 ± 0.108, 3.704 ± 0.106 and 3.279 ± 0.161 in normal mucosa, Grades I, II and III of OSF, respectively. A qualitative difference was observed in the presentation of AgNORs in different grades of OSF. Mean value of small nucleolar organizer regions (NORs) decreased while the mean of large NORs increased as the grade of OSF increased.

Conclusions:

The study findings suggest that AgNORs are increased in OSF and they can serve as a reliable tool adjunct to histopathological diagnosis. Their ease of demonstration and high specificity to cellular proliferation make them the best available histopathological marker in the arsenal of an oral pathologist.

Digital image analysis of AgNORs in cervical smears of women with premalignant and malignant lesions of the uterine cervix

We performed a hospital-based, unmatched case-control study to investigate the association between progressive stages of cervical neoplasia and digital analysis of cell proliferation by silver stained nucleolus organizer region associated proteins (AgNORs). We measured cell proliferation levels in the cervical epithelial cells of 10 women with low grade squamous intraepithelial lesions (LG-SIL), eight with high grade squamous intraepithelial lesions (HG-SIL), 11 with cervical cancer (CC) and eight with no cervical lesions (controls) using the AgNORs technique. Cell proliferation was measured by digital image analysis (DIA). DIA revealed increased total areas of AgNORs in HG-SIL and CC compared to LG-SIL and control patients. AgNORs with a kidney or cluster shape exhibited greater areas than those with a spherical or long shape. We propose a cut-off of 118 pixels to differentiate benign (control and LG-SIL) from malignant (HG-SIL and CC) lesions. DIA of AgNORs is a simple and inexpensive method for studying proliferation. The increased total area of AgNORs in malignant lesions provides information regarding cell behavior and may be related to cervical carcinogenesis; however, further validation studies are required to establish its usefulness in cytological analysis.

Proliferating fibroblasts and HeLa cells co-cultured in vitro reciprocally influence growth patterns, protein expression, chromatin features and cell survival

AIM

to identify biological interactions between proliferating fibroblasts and HeLa cells in vitro.

MATERIALS AND METHODS

Fibroblasts were isolated from both normal and tumour human tissues. Coverslip co-cultures of HeLa and fibroblasts in various ratios with medium replacement every 48 h were studied using fixed cell staining with dyes such as Giemsa and silver staining, with immunochemistry for Ki-67 and E-cadherin, with dihydrofolate reductase (DHFR) enzyme reaction, as well as live cell staining for non-specific esterases and lipids. Other techniques included carmine cell labeling, autoradiography and apoptosis assessment.

RESULTS

Under conditions of feeding and cell: cell ratios allowing parallel growth of human fibroblasts and HeLa cells, co-cultured for up to 20 days, a series of phenomena occur consecutively: profound affinity between the two cell types and exchange of small molecules; encircling of the HeLa colonies by the fibroblasts and enhanced growth of both cell types at their contact areas; expression of carbonic anhydrase in both cell types and high expression of non-specific esterases and cytoplasmic argyrophilia in the surrounding fibroblasts; intense production and secretion of lipid droplets by the surrounding fibroblasts; development of a complex net of argyrophilic projections of the fibroblasts; E-cadherin expression in the HeLa cells; from the 10th day onwards, an increasing detachment of batches of HeLa cells at the peripheries of colonies and appearance of areas with many multi-nucleated and apoptotic HeLa cells, and small HeLa fragments; from the 17th day, appearance of fibroblasts blocked at the G2-M phase. Co-cultures at approximately 17-20 days display a cell-cell fight with foci of (a) sparse growth of both cell types, (b) overgrowth of the fibroblasts and (c) regrowth of HeLa in small colonies. These results indicate that during their interaction with HeLa cells in vitro, proliferating fibroblasts can be activated against HeLa. This type of activation is not observed if fibroblast proliferation is blocked by contact inhibition of growth at confluency, or by omitting replacement of the nutrient medium.

CONCLUSION

The present observations show that: (a) interaction between proliferating fibroblasts and HeLa cells in vitro drastically influences each other's protein expression, growth pattern, chromatin features and survival; (b) these functions depend on the fibroblast/HeLa ratio, cell topology (cell-cell contact and the architectural pattern developed during co-culture) and frequent medium change, as prerequisites for fibroblast proliferation; (c) this co-culture model is useful in the study of the complex processes within the tumour microenvironment, as well as the in vitro reproduction and display of several phenomena conventionally seen in tumour cytological sections, such as desmoplasia, apoptosis, nuclear abnormalities; and (d) overgrown fibroblasts adhering to the boundaries of HeLa colonies produce and secrete lipid droplets.

Comparative cytogenetics of two endangered leuciscine fish, Squalius aradensis and S. torgalensis (Teleostei, Cyprinidae), from the Iberian Peninsula

In this study, the description of the karyotypes of the endangered chubs Squalius aradensis (Coelho, Bogutskaya, Rodrigues and Collares-Pereira, 1998) and Squalius torgalensis (Coelho, Bogutskaya, Rodrigues and Collares-Pereira, 1998) is presented by means of conventional (Giemsa-staining, Chromomycin A3 (CMA3)-fluorescence, Silver-impregnation (Ag-NORs)) and molecular (fluorescence in situ hybridization (FISH) with 18S rDNA probe) protocols. These endemic sister-species have an allopatric but adjacent distribution in the most southwestern part of the Iberian Peninsula. Diploid chromosome number was invariably 2n = 50 and karyotypes of both species were grossly similar, composed of metacentric and submetacentric elements with a reduced number of acrocentric pairs. Sequential staining using FISH with an 18S rDNA probe, CMA3 and Ag-NORs treatments revealed consistent positive signals located at the end of the short arms of a submetacentric chromosome pair, likely homologous in both species. While providing useful cytogenetic comparative data against other members of the genus Squalius Bonaparte, 1837, the work aimed to draw attention towards the conservation of two narrow-range and highly confined fish species.

Application of the comet assay in erythrocytes of Oreochromis niloticus (Pisces): A methodological comparison

The present study applied the comet assay to erythrocytes of Oreochromis niloticus with the aim of improving protocols to detect DNA damage in these cells, by using two distinct pHs (pH = 12.1 and pH > 13) and evaluating whether there is a correspondence between silver and ethidium bromide staining. Comets were visually examined and, the frequency of cells with and without damage was obtained, as well as the distribution of classes and scores. By using the Kruskal-Wallis test, our results revealed that pH 12.1 is more effective, although both pHs can be used. Our findings also suggest that silver staining can substitute ethidium bromide, an expensive and highly toxic stain that requires specific equipment for examination.

NORs and their transcription competence during the cell cycle

In human cells ribosomal genes are organized as clusters, NORs, situated on the short arms of acrocentric chromosomes. It was found that essential components of the RNA polymerase I transcription machinery, including UBF, can be detected on some NORs, termed "competent" NORs, during mitosis. The competent NORs are believed to be transcriptionally active during interphase. However, since individual NORs were not observed in the cell nucleus, their interphase status remains unclear. To address this problem, we detected the competent NORs by two commonly used methods, UBF immunofluorescence and silver staining, and combined them with FISH for visualization of rDNA and/or specific chromosomes. We found that the numbers of competent NORs on specific chromosomes were largely conserved in the subsequent cell cycles, with certain NOR-bearing homologues displaying a very stable pattern of competence. Importantly, those and only those NORs that were loaded with UBF incorporated bromo-uridine in metaphase after stimulation with roscovitine and in telophase, suggesting that competent and only competent NORs contain ribosomal genes transcriptionally active during interphase. Applying premature chromosome condensation with calyculin A, we visualized individual NORs in interphase cells, and found the same pattern of competence as observed in the mitotic chromosomes.