A comparison of teleost rodlet cells with apicomplexan cells.

Rodlet cells are unique pear-shaped cells found primarily in the epithelium of the teleost fishes. The rodlet cell was first identified by Thèlohan in 1892 who named it Rhabdospora thelohani as it was believed to be a protozoan parasite of the phylum Apicomplexa. The rodlet cell as parasite paradigm persisted for several decades afterwards but has since faded in the last 20 years or so. The rodlet cell is now generally believed to be an immune cell, functioning as an early responder to parasite intrusion. This short review makes a detailed comparison of apicomplexan structure and behavior with that of the rodlet cell to further strengthen the argument against a parasitic nature for the fish cell. It is then proposed that apical microvilli of the rodlet cell serve as a mechanical trigger for rodlet discharge as possible defense against larger ectoparasites.

Differential mucins secretion by intestinal mucous cells of Chelon ramada in response to an enteric helminth Neoechinorhynchus agilis (Acanthocephala).

Intestinal mucous cells produce and secrete mucins which hydrate, lubricate and protect the intestinal epithelium from mechanical injuries due to the transition of digesta or action of pathogens. Intestinal mucous cells are considered elements of the innate immune system as they secrete lectins, toxins, immunoglobulins, and anti-microbial peptides. Acid mucins can surround and eliminate many pathogenic microorganisms. We performed a quantitative analysis of the density and mucus composition of different intestinal mucous cell types from mullet (Chelon ramada) that were infected solely with Neoechinorhynchus agilis. Most N. agilis were encountered in the middle region of the intestine. Mucous cell types were identified with Alcian Blue (pH2.5) and Periodic acid-Schiff (PAS) histochemistry, and by staining with a panel of seven lectins. Mucus enriched for high viscosity acid mucins was accumulated near points of worm attachment. Parasites were surrounded by an adherent mucus layer or blanket. Ultrastructural examination showed intestinal mucous cells typically possessed an elongated, basally positioned nucleus and numerous electron dense and lucent vesicles in the cytoplasm. The results show both an increase in mucus production and changes in mucin composition in infected mullet in comparison with uninfected conspecifics.

Perfluorooctanoic Acid Exposure Assessment on Common Carp Liver through Image and Ultrastructural Investigation.

Perfluorooctanoic acid (PFOA) poses particular concern as an emerging pollutant in both surface and ground waters. Fish, as a natural inhabitant of these waters and being highly representative of vertebrates, represents an ideal animal model to assess the toxic effects of PFOA. Hereby, liver microscopic texture was comparatively evaluated in individuals of common carp subchronically exposed to PFOA using grayscale differential box counting, a fractal analysis method. Furthermore, liver cytoplasmic glycogen areas and ultrastructure were also evaluated and compared to the image analysis findings. Redundancy Analysis was performed to assess, in summary, how much the variation of fractal dimension and lacunarity was explained by the concentration of PFOA in liver, the mass of liver and the number of proliferating cell nuclear antigen (PCNA)-immunoreactive nuclei. Treatment group ordination was better determined by fractal dimension than lacunarity. Interestingly, a significant complexity increase was associated with the modification of liver microscopic texture due to PFOA exposure. This complexity increase was related to "cloudy swelling", possibly representing a primarily adaptive strategy against PFOA challenge, rather than a slight, reversible form of degeneration as traditionally proposed. The occurrence of endoplasmic reticulum stress, unfolded protein reaction and hormetic response was proposed and discussed.

Case Report: Kryptonite-A Rare Case of Left-Sided Bilothorax in a Sickle Cell Patient.

Bilothorax is a rare cause of an exudative pleural effusion. The diagnosis is confirmed by a pleural fluid to serum bilirubin ratio of greater than 1. Typically, bilothorax presents as a right-sided effusion due to its proximity to the liver and biliary system. Herein, we present a case of isolated left-sided bilothorax in a 43-year-old female admitted with sickle cell crisis. Only one other case of isolated spontaneous left-sided bilothorax has been described in the literature. A thoracentesis performed on admission demonstrated greenish fluid and bilothorax was suspected, with a pleural fluid to serum bilirubin ratio greater than 1 confirming the diagnosis. A magnetic resonance cholangiopancreatography (MRCP) showed an abnormal 90-degree acute angulation in the mid-to-distal common bile duct with proximal common bile duct and intrahepatic bile ducts dilation. This was further confirmed with an endoscopic retrograde cholangiopancreatography (ERCP), which did not reveal any extravasation of contrast into the left pleural space. Ultimately, despite the use of various modalities, no definitive cause of bilothorax was identified. Postthoracentesis imaging revealed evidence of fibrothorax, a direct and permanent complication of bilothorax. The presence of an isolated left-sided bilothorax, along with the lack of a confirmed etiology, makes this case unique.

Description of epithelial granular cell in catshark spiral intestine: Immunohistochemistry and ultrastructure.

We evaluated the histology of the spiral intestine of the blackmouth catshark (Galeus melastomus), a small shark distributed in the eastern Atlantic and Mediterranean Sea basin. Entire digestive tracts of 10 G. melastomus were studied using histochemical, immunohistochemical, and ultrastructural methods. Our studies identified a unique, large granular cell type in the intestinal epithelium. Transmission electron microscopy showed that the epithelial granular cell type made intimate contact, by means of junctional complexes, with adjacent epithelial and mucous cells. Several histochemical staining methods showed that the cytoplasmic granules were strongly eosinophilic. Immunostaining of intestinal sections revealed immunoreactivity of the granular cell to tumor necrosis factor-α (TNF-α) antibody. However, no reactivity to inducible-nitric oxide synthase (i-NOS), interleukin-6 (IL-6), interleukin IL-1ß, lysozyme, serotonin 5-HT antibodies was detected.

Actin Microridges.

Microridges are highly distinctive "fingerprint"-patterned structures situated on the outer surface of superficial layer cells of the epithelium. An F-actin-based cytoskeleton is the underlying core structural component of microridges. The basis for much of what is known about microridges has been provided by in vivo and in vitro fish epithelial systems. Nonetheless the microridge literature is quite small, especially when compared with other actin-based cellular structures such as those involved in cell motility. A PubMed search of the terms "Microridges" yields 261 citations from the mid-1970s to the writing of this review. "Microplicae," an alternative name for microridges, and "Actin Microridges" search terms give 204 and 8 references, respectively, in the same time period. By comparison a search of "Lamellipodia" over the same time period yields over 6,400 citations for this important motility structure while a search of the associated "filopodia" results in close to 7,300 articles. Despite the near-ubiquity of microridges in epithelia across species the study of these structures has clearly been neglected. In-depth analysis of microridge molecular composition is very limited while their function remains unclear. This review draws upon information derived from studies of fish as well as mammalian species to provide a more comprehensive view of these structures. The wide-spread distribution of these structures between species and various tissues indicate the microridges have important and common functions in healthy organisms. Conversely, disease conditions may show alterations in microridge structure and function and thus warrant further investigation. Anat Rec, 301:2037-2050, 2018. © 2018 Wiley Periodicals, Inc.

Pigmented macrophages and related aggregates in the spleen of european sea bass dosed with heavy metals: Ultrastructure and explorative morphometric analysis.

The ultrastructure and morphometrics of pigmented macrophages (PMs) were assessed in the spleen of European sea bass experimentally dosed with Cd and Hg. PMs occurred either as solitary cells or as variably structured aggregations, defined as macrophage aggregates (MAs). Light microscopy revealed a high degree of morphological heterogeneity amongst MAs of all experimental groups. At the ultrastructural level, MAs showed a heterogeneous pigment content that was not influenced by the treatment. Cytoplasm rarefaction/vacuolation and euchromatic nuclei, were observed in PMs of dosed fish. Undosed and Cd-dosed samples differ significantly with regard to the following morphometric features: the Minor axis of the best fitting ellipse, Aspect Ratio, and Roundness. In Cd-dosed fish, MAs showed reduced size and complexity. Lacunarity showed significant differences between undosed and both Cd and Hg-dosed samples. These results suggest that heavy metals, and especially Cd, may influence the dynamics of PM aggregation/disaggregation. Variability in splenic MAs was observed both by light and electron microscopy. However, only the morphometric techniques adequately and objectively described the phenomenon, allowing a quantitative/statistical comparison of morphology among experimental groups. These morphometric analyses could be usefully applied in toxicological and ecotoxicological, as well as morpho-functional studies.

Dual Antiplatelet Therapy and the Severity Risk of Lower Intestinal Bleeding.

BACKGROUND: Dual antiplatelet (Plt) therapy with aspirin and clopidogrel is recommended for up to 1 year following acute coronary syndrome. Many of these cardiac patients are also on anithrombotic therapy like warfarin. Lower gastrointestinal bleeding (LGIB) is the main adverse event of this treatment. AIMS: The main purpose of this study was to analyze the relationship of dual anti-Plt therapy and the risk of LGIB. METHODS: Patients' electronic charts were reviewed to include a total of 19 variables, which included age, sex, ethnicity, daily use aspirin of any dose, daily use of clopidogrel, use of nonsteroidal anti-inflammatory drugs (NSAIDs) at least twice in the last week prior to admission and the daily use of anticoagulants (warfarin, heparin), and were obtained from history and physical examination reports, lab transcripts and procedural reports. SETTINGS/DESIGN: A retrospective cohort study of the records of 3436 patients admitted to our hospital from January 1, 2009, to December 31, 2011, was evaluated. All the patients included were admitted through the emergency department with complaints of or relating to LGIB. The primary outcome studied was severe LGIB as defined by the requirement of at least two units of packed red blood cells and/or a decrease in the hematocrit of 20% or more or recurrent bleeding after 24 h of clinical stability with additional transfusions required. Other outcomes included surgical intervention. STATISTICAL METHODS/ANALYSIS: Univariate analysis using t-test on continuous variables and Chi-square test on categorical variables were done before carrying out logistic regression analysis. Logistic regression analyses were conducted to measures of association between the variables and LGIB. Logistic regression analysis was not carried for surgical intervention and death because none of the variables was significant from univariate tests. RESULTS: A total of 511 patients were found to have true LGIB. Among these subjects, 61 were shown to be on dual or multiple antithrombotic therapies. Further exploration revealed that while the use of multiple blood thinning agents may, in fact, pose a significant risk to overall LGIB, it did not significantly increase the risk for severe bleeding as outlined above. CONCLUSION: The use of multiple blood thinning agents does not significantly increase the risk for severe LGIB.

Nematode infection in liver of the fish Gymnotus inaequilabiatus (Gymnotiformes: Gymnotidae) from the Pantanal Region in Brazil: pathobiology and inflammatory response.

BACKGROUND: A survey on endoparasitic helminths from freshwater fishes in the Pantanal Region (Mato Grosso do Sul, Brazil) revealed the occurrence of third-larval stage of the nematode Brevimulticaecum sp. (Heterocheilidae) in most organs of Gymnotus inaequilabiatus (Gymnotidae) also known by the local name tuvira. The aim of the present study was to examine Brevimulticaecum sp.-infected tuvira liver at the ultrastructural level and clarify the nature of granulomas and the cellular elements involved in the immune response to nematode larvae. METHODS: Thirty-eight adult specimens of tuvira from Porto Morrinho, were acquired in January and March 2016. Infected and uninfected liver tissues were fixed and prepared for histological and ultrastructure investigations. RESULTS: The prevalence of infection of tuvira liver by the nematode larvae was 95 %, with an intensity of infection ranging from 4 to 343 larvae (mean ± SD: 55.31 ± 73.94 larvae per liver). In livers with high numbers of nematode larvae, almost entire hepatic tissue was occupied by the parasites. Hepatocytes showed slight to mild degenerative changes and accumulation of pigments. Parasite larvae were surrounded by round to oval granulomas, the result of focal host tissue response to the infection. Each granuloma was typically formed by three concentric layers: an outer layer of fibrous connective tissue with thin elongated fibroblasts; a middle layer of mast cells entrapped in a thin fibroblast-connective mesh; and an inner layer of densely packed epithelioid cells, displaying numerous desmosomes between each other. Numerous macrophage aggregates occurred in the granulomas and in the parenchyma. CONCLUSIONS: Our results in tuvira showed that the larvae were efficiently sequestered within the granulomas, most of the inflammatory components were confined within the thickness of the granuloma, and the parenchyma was relatively free of immune cells and without fibrosis. Presumably this focal encapsulation of the parasites permits uninfected portions of liver to maintain its functions and allows the survival of the host.

Multivariate approach to gill pathology in European sea bass after experimental exposure to cadmium and terbuthylazine.

The combined use of guided quantitative expert analysis and of multivariate exploratory data analysis is reported as a robust, sensitive and sufficiently specific approach to study European sea bass gill secondary lamellar pathology after exposure to incremental doses of cadmium and terbuthylazine up to 48h. The following elementary pathological findings were considered: "epithelial lifting", "epithelial shrinkage", "epithelial swelling", "pillar cells coarctation", "pillar cells detachment", "channels fusion", "chloride cells swelling", and "chloride cells invasion". The relative spatial extension was determined according to exposure class and data were analyzed by means of canonical correspondence analysis (CCA), linear discriminant analysis (LDA) and canonical variates analysis (CVA). Histologically and ultrastructurally, cellular shrinkage/coarctation prevailed in cadmium exposed lamellae, whereas cellular swelling and epithelial lifting were predominant in terbuthylazine exposed lamellae compared to unexposed fish. Both CCA and CVA permit a good graphical data grouping according to exposure classes by means of the convex hull minimum polygons. This also reveals exposure dose and time gradients in CCA plot. Accordingly, epithelial swelling and epithelial shrinkage were comparatively associated to higher exposure time, whereas epithelial shrinkage and pillar cells coarctation were comparatively associated to higher exposure dose. LDA with only "epithelial shrinkage", "epithelial swelling" and "pillar cells coarctation" in the model classified correctly 87.5% of the cross-validated cases. A possible pathogenetic relationship between the discriminant elementary lesions and the toxic mode of action at the cellular level of both cadmium and terbuthylazine is also discussed.

Occurrence of immune cells in the intestinal wall of Squalius cephalus infected with Pomphorhynchus laevis.

A sub-population of 34 specimens of chub, Squalius cephalus, was sampled from the River Brenta (Northern Italy) and examined for ecto- and endo-parasites. Pomphorhynchus laevis (Acanthocephala) was the only enteric helminth encountered. Immunofluorescence and ultrastructural studies were conducted on the intestines of chub. Near the site of parasite's attachment, mucous cells, mast cells (MCs), neutrophils and rodlet cells (RCs) were found to co-occur within the intestinal epithelium. The numbers of mucous cells, MCs and neutrophils were significantly higher in infected fish (Mann-Whitney U test, p < 0.05). Dual immunofluorescence staining with the lectin Dolichos Biflorus Agglutinin (DBA) and the macrophage-specific MAC387 monoclonal antibody, with parallel transmission electron microscopy, revealed that epithelial MCs often made intimate contact with the mucous cells. Degranulation of a large number of MCs around the site of the acanthocephalan's attachment and in proximity to mucous cells was also documented. MCs and neutrophils were abundant in the submucosa. Immune cells of the intestinal epithelium have been described at the ultrastructural level and their possible functions and interactions are discussed.

Small Bowel Obstruction Mimicking Acute ST-Elevation Myocardial Infarction.

We present a case of a 42-year-old female who presented to our institution with a small bowel obstruction and had emergent surgical decompression. Thirteen days postoperatively, the patient became tachycardic and had worsening epigastric pain. Electrocardiogram showed significant ST-segment elevations in leads II, III, aVF, and V3-V6, suggesting the possibility of acute inferolateral myocardial infarction. Subsequent workup revealed the cause of the ST-elevations to be due to recurrent small bowel obstruction. Although intra-abdominal causes of ST-elevation have been reported, our case may be the first to be associated with small bowel obstruction.

Multiple gastrointestinal complications of crack cocaine abuse.

Cocaine and its alkaloid free base "crack-cocaine" have long since been substances of abuse. Drug abuse of cocaine via oral, inhalation, intravenous, and intranasal intake has famously been associated with a number of medical complications. Intestinal ischemia and perforation remain the most common manifestations of cocaine associated gastrointestinal disease and have historically been associated with oral intake of cocaine. Here we find a rare case of two relatively uncommon gastrointestinal complications of hemorrhage and pancreatitis presenting within a single admission in a chronic crack cocaine abuser.

Strongyloidiasis: the cause of multiple gastrointestinal ulcers in an immunocompetent individual.

Strongyloidiasis is a common parasitic disease in tropical regions of the world. Infection with Strongyloides stercoralis usually remains asymptomatic with peripheral eosinophilia and uncontrolled growth. Consequently, immunocompromised individuals are at a higher risk of complications of this disease. We present a case of an immunocompetent patient whose complaint of acute abdominal pain was found to be due to gastric and duodenal ulcerations. Laboratory examination revealed significantly elevated absolute eosinophil count at 11,466/mm(3) (normal 0-700/mm(3)). The duodenal biopsy revealed parasitic ova and adult worms suggestive of Strongyloides stercoralis nematode with increased eosinophils in the tissue. We report the first case of multiple gastric and duodenal ulcerations due to Strongyloides stercoralis in an immunocompetent patient. We suggest that the elevated eosinophil count played a central role in the pathogenesis.

Iridium dihydroxybipyridine complexes show that ligand deprotonation dramatically speeds rates of catalytic water oxidation.

We report highly active iridium precatalysts, [Cp*Ir(N,N)Cl]Cl (1-4), for water oxidation that are supported by recently designed dihydroxybipyridine (dhbp) ligands. These ligands can readily be deprotonated in situ to alter the electronic properties at the metal; thus, these catalyst precursors have switchable properties that are pH-dependent. The pKa values in water of the iridium complexes are 4.6(1) and 4.4(2) with (N,N) = 6,6'-dhbp and 4,4'-dhbp, respectively, as measured by UV-vis spectroscopy. For homogeneous water oxidation catalysis, the sacrificial oxidant NaIO4 was found to be superior (relative to CAN) and allowed for catalysis to occur at higher pH values. With NaIO4 as the oxidant at pH 5.6, water oxidation occurred most rapidly with (N,N) = 4,4'-dhbp, and activity decreased in the order 4,4'-dhbp (3) > 6,6'-dhbp (2) ≫ 4,4'-dimethoxybipyridine (4) > bipy (1). Furthermore, initial rate studies at pH 3-6 showed that the rate enhancement with dhbp complexes at high pH is due to ligand deprotonation rather than the pH alone accelerating water oxidation. Thus, the protic groups in dhbp improve the catalytic activity by tuning the complexes' electronic properties upon deprotonation. Mechanistic studies show that the rate law is first-order in an iridium precatalyst, and dynamic light scattering studies indicate that catalysis appears to be homogeneous. It appears that a higher pH facilitates oxidation of precatalysts 2 and 3 and their [B(Ar(F))4](-) salt analogues 5 and 6. Both 2 and 5 were crystallographically characterized.

Radiofrequency ablation for the treatment of radiation proctitis: a case report and review of literature.

Radiation proctitis is a frequent complication of pelvic radiation for cancer. This condition can present acutely within several weeks of radiation, or chronically many months or years after radiation, leading to rectal bleeding and transfusion-dependent anemia. Various medical and endoscopic therapies have been described to treat this condition; however, some patients fail to respond to the current standard therapies. Here we present a case of refractory radiation proctitis, with suboptimal response to other therapies, treated successfully with a novel method, radiofrequency ablation.

Pleural Empyema due to Group D Salmonella.

Non-typhi Salmonella normally presents as a bacteremia, enterocolitis, and endovascular infection but rarely manifests as pleuropulmonary disease. We present a case of a 66-year-old female with underlying pulmonary pathology, secondary to an extensive smoking history, who presented with a left-sided pleural effusion. The causative agent was identified as being group D Salmonella. Decortication of the lung was performed and the patient was discharged on antibiotics with resolution of her symptoms. This case helps to support the inclusion of Salmonella group D as a possible etiological agent of infection in the differential causes of exudative pleural effusions.