Cellular Exudate Research Articles

Pathogenicity of Mycoplasma hyopneumoniae strain in Naturally Infected Slaughtered Pigs in Nigeria: Immunohistochemical and Ultrastructural Studies

Enzootic pneumonia caused by Mycoplasma hyopneumoniae (MHYO) remains a serious concern to swine industry in many countries including Nigeria. MHYO strains isolated from different countries and geographical locations are known to vary in pathogenicity in pigs. There is paucity of information on the pathogenicity of MHYO strain affecting pigs in Nigeria. This study investigated the pathogenicity of MHYO strain in naturally infected slaughtered pigs in Nigeria using immunohistochemistry and electron microscopy. Two hundred and sixty four lungs were randomly collected from abattoirs at Abeokuta, Ibadan and Lagos, Southwest Nigeria. A sub‐sample of 104 pneumonic lungs was selected, processed for routine histopathological examination and immunohistochemistry, while 3 lung tissues were selected for ultrastructural studies. The most significant microscopic changes were suppurative broncho‐interstitial pneumonia associated with varying degrees of lymphoid hyperplasia of the bronchus‐associated lymphoid tissue (BALT) and thickening of alveolar septa due to cellular infiltration. Immunohistochemically, MHYO antigens were detected in 86/104 (82.7%) lungs. Bronchial and bronchiolar epithelial cells typically exhibited a granular brown reaction on the surface, in the BALT and luminal cellular exudates of MHYO‐infected lung tissues. Transmission electron microscopy revealed numerous Mycoplasmas in the lumina of respiratory tract, in between degenerated cilia, while a few Mycoplasmas were located within the alveoli. It is concluded that the MHYO strain detected in this study is pathogenic to pigs and capable of inducing pneumonic lesions, and therefore implicated in the pathogenesis. This is the first investigative study on pathogenicity of MYHO strain in slaughtered pigs in Nigeria.Support or Funding InformationSupport from the Federal University of Agriculture, AbeokutaThis abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.

Heavy metal stress and responses in plants

Heavy metals such as Fe, Mn, Cu, Ni, Co, Cd, Zn, Hg and arsenic are for long being accumulated in soils through industrial waste and sewage disposal. Although some of these metals are essential micronutrients responsible for many regular processes in plants, their excess, however, can have detrimental effects and can directly influence the plant growth, metabolism, physiology and senescence. Plants have different mechanisms to fight stress, and they are responsible to maintain homeostasis of essential metals required by plants. These mechanisms also focus on prevention of plants exposure to heavy metals present in the soil or providing tolerance to the plant by detoxifying the metals. Other mechanisms are specific and are initiated when the respective stress is encountered. The first line of defense provided by a plant is to reduce the uptake of metals when stimulated with toxicity of heavy metals and includes the help offered by cellular and root exudates that restricts metals from entering the cell. Many plants have exclusive mechanisms for individual metal ions and are involved in sequestering these ions in compartments avoiding their exposure to sensitive components of the cells. As a second line of defense, other mechanisms for detoxification of these metals are introduced that chelates, transports, sequesters and detoxifies these metal ions in the plant’s vacuole. During the time of metal toxicity, oxidative stress is pronounced in the cells and production of stress-related proteins and hormones, antioxidants, signaling molecules including heat-shock proteins synthesis is initiated.

From manual periodontal probing to digital 3-D imaging to endoscopic capillaroscopy: Recent advances in periodontal disease diagnosis.

Deepened periodontal pockets exert a significant pathological burden on the host and its immune system, particularly in a patient with generalized moderate to severe periodontitis. This burden is extensive and longitudinal, occurring over decades of disease development. Considerable diagnostic and prognostic successes in this regard have come from efforts to measure the depths of the pockets and their contents, including level of inflammatory mediators, cellular exudates and microbes; however, the current standard of care for measuring these pockets, periodontal probing, is an analog technology in a digital age. Measurements obtained by probing are variable, operator dependent and influenced by site-specific factors. Despite these limitations, manual probing is still the standard of care for periodontal diagnostics globally. However, it is becoming increasingly clear that this technology needs to be updated to be compatible with the digital technologies currently being used to image other orofacial structures, such as maxillary sinuses, alveolar bone, nerve foramina and endodontic canals in 3 dimensions. This review aims to summarize the existing technology, as well as new imaging strategies that could be utilized for accurate evaluation of periodontal pocket dimensions.

Microbially mediated aluminosilicate formation in acidic anaerobic environments: A cell-scale chemical perspective.

Through the use of scanning transmission electron microscopy (STEM) combined with other complementary techniques (SEM, cryo-TEM, HRTEM, and EELS), we have studied the interaction of microorganisms inhabiting deep anoxic waters of acidic pit lakes with dissolved aluminum, silica, sulfate, and ferrous iron. These elements were close to saturation (Al, SiO2 ) or present at very high concentrations (0.12m Fe(II), 0.12-0.22m SO42- ) in the studied systems. The anaerobic conditions of these environments allowed investigation of geomicrobial interactions that are difficult to see in oxidized, Fe(III)-rich environments. Detailed chemical maps and through-cell line scans suggest both extra- and intracellular accumulation of Al, Si, S, and Fe(II) in rod-like cells and other structures (e.g., spherical particles and bacteriomorphs) of probable microbial origin. The bacterial rods showed external nanometric coatings of adsorbed Fe(II) and Al on the cell surface and cell interiors with significant presence of Al, Si, and S. These microbial cells coexist with spherical particles showing similar configuration (Fe(II) external coatings and [Al, Si, S]-rich cores). The Al:Si and Al:S ratios and the good Al-Si correlation in the cell interiors suggest the concurrent formation of two amorphous phases, namely a proto-aluminosilicate with imogolite-like composition and proto-hydrobasaluminite. In both cases, the mineralization appears to comprise two stages: a first stage of aluminosilicate and Al-hydroxysulfate precipitation within the cell or around cellular exudates, and a second stage of SO42- and Fe(II) adsorption on surface sites existing on the mineral phases in the case of (SO42- ) or on presumed organic molecules [in the case of Fe(II)]. These microbially related solids could have been formed by permineralization and mineral replacement of senescent microbial cells. However, these features could also denote biomineralization by active bacterial cells as a detoxification mechanism, a possibility which should be further explored. We discuss the significance of the observed Al/microbe and Si/microbe interactions and the implications for clay mineral formation at low pH.

Controls over δ44/40Ca and Sr/Ca variations in coccoliths: New perspectives from laboratory cultures and cellular models

Coccoliths comprise a major fraction of the global carbonate sink. Therefore, changes in coccolithophores' Ca isotopic fractionation could affect seawater Ca isotopic composition, affecting interpretations of the global Ca cycle and related changes in seawater chemistry and climate. Despite this, a quantitative interpretation of coccolith Ca isotopic fractionation and a clear understanding of the mechanisms driving it are not yet available. Here, we address this gap in knowledge by developing a simple model (CaSri–Co) to track coccolith Ca isotopic fractionation during cellular Ca uptake and allocation to calcification. We then apply it to published and new δ44/40Ca and Sr/Ca data of cultured coccolithophores of the species Emiliania huxleyi and Gephyrocapsa oceanica. We identify changes in calcification rates, Ca retention efficiency and solvation–desolvation rates as major drivers of the Ca isotopic fractionation and Sr/Ca variations observed in cultures. Higher calcification rates, higher Ca retention efficiencies and lower solvation–desolvation rates increase both coccolith Ca isotopic fractionation and Sr/Ca. Coccolith Ca isotopic fractionation is most sensitive to changes in solvation–desolvation rates. Changes in Ca retention efficiency may be a major driver of coccolith Sr/Ca variations in cultures. We suggest that substantial changes in the water structure strength caused by past changes in temperature could have induced significant changes in coccolithophores' Ca isotopic fractionation, potentially having some influence on seawater Ca isotopic composition. We also suggest a potential effect on Ca isotopic fractionation via modification of the solvation environment through cellular exudates, a hypothesis that remains to be tested.

The effect of immobilization induced stress on the lung of the adult male albino rat and the possible protective role of melatonin: A light, electron microscopic and immunohistochemical study

Background: Stress is known as one of the most important reasons of many diseases. Immobilization is one of the most common performed stresses on animals. immobilization stress may induce the formation of reactive oxygen species and can lead to suppression of immune system. Melatonin as an antioxidant, has an important role in the immune function. The lung has a large surface that is constantly in contact with air oxygen and pollutants. It is one of the organs commonly affected by reactive oxygen species generation which induces oxidative damage. It is a site of major reactive oxygen species production.Aim of work: The present study aimed to investigate the effect of immobilization induced stress on the lung in the adult male albino rat and the possible protective role of melatonin.Material and Methods: 45 adult male albino rats weighing 200–250 g were used in this study. The rats were randomly divided into three equal groups (15 rats each). Group (I): the rats kept undisturbed and served as non-stress control group. They were sacrificed at the end of the experiment. Group (II): the rats subjected to stress and placed on a wooden plate with their trunks wrapped in a confining harness for 90 min 5 days/week for 6 weeks. The animal was able to move its limbs and head but not its trunk. Group (III): the rats were exposed to stress as previously described and concurrently injected melatonin intraperitoneally in a dose of 10 mg/kg/day at 4:00 pm. All animals were sacrificed by decapitation under anaesthesia at the same time, then lungs dissected out. The specimens of each group were randomly divided into three subgroups; the first was processed for the light microscopic study (H & E), the second for the transmission electron microscopic study and the third for the immunohistochemical study (Caspase-3 and iNOS). Morphometric studies and statistical analysis were performed.Results: The light microscopic and ultrastructural examination of the rat lungs after immobilization showed severe alveolar damage in the form of collapsed alveolar saccule and alveoli, markedly thickened interalveolar septa encroaching on alveoli, heavy inflammatory cellular infiltration and exudation. Pneumocyte type I showed indentation of its nuclear membrane, presence of chromatin clumps inside the nucleus and swollen mitochondria with disrupted cristae. Melatonin treated group revealed an evident reduction of all alveolar changes with nearly normal structure of the alveolar ducts, alveolar saccules and alveoli. Immunohistochemically stained lung sections for caspase-3 and iNOS after immobilization showed an intense brownish immune reactions. Melatonin treated group revealed a noticeable reduction in the immune reactions.Conclusion: Immobilization stress has a damaging effect on the histological structure of the lung and a concomitant treatment with an antioxidant (melatonin) effectively protected the lung tissue.

Importance of allochthonous and autochthonous dissolved organic matter in Fe(II) oxidation: A case study in Shizugawa Bay watershed, Japan

Ferrous iron (Fe[II]) oxidation by dissolved oxygen was investigated in the Shizugawa Bay watershed with particular attention given to the effect of dissolved organic matter (DOM) properties on Fe(II) oxidation. To cover a wide spectrum of DOM composition, water samples were collected from various water sources including freshwater (e.g., river water and wastewater effluent) and coastal seawater. Measurement of nanomolar Fe(II) oxidation by using luminol chemiluminescence under dark, air-saturated conditions at 25 °C indicated that spatio-temporal variation of the second-order rate constant (6.7–74.5 M−1 s−1) was partially explained by the variation of the sample pH (7.5–8.6). However, at comparable pH values, the oxidation rates for freshwater were generally greater than those for coastal seawater. The substantial decline in oxidation rate constant after the removal of humic-type (allochthonous) DOM suggested that this hydrophobic DOM is a key factor that accelerates the Fe(II) oxidation in the freshwater samples. Observed lower oxidation rates for coastal seawater compared with freshwater and organic ligand-free seawater were likely associated with microbially derived autochthonous DOM, and the variation of Fe(II) oxidation at a fixed pH was best described by fluorescence index that represents the proportion of autochthonous and allochthonous DOM in natural waters. Consistently, Fe(II) oxidation was found to be slower in the presence of cellular exudates from phytoplankton. The present study highlighted the significant effect of DOM composition on the Fe(II) oxidation in inland and coastal waters.

Cell surface acid-base properties of the cyanobacterium Synechococcus: Influences of nitrogen source, growth phase and N:P ratios

The distribution of many trace metals in the oceans is controlled by biological uptake. Recently, Liu et al. (2015) demonstrated the propensity for a marine cyanobacterium to adsorb cadmium from seawater, suggesting that cell surface reactivity might also play an important role in the cycling of metals in the oceans. However, it remains unclear how variations in cyanobacterial growth rates and nutrient supply might affect the chemical properties of their cellular surfaces. In this study we used potentiometric titrations and Fourier Transform Infrared (FT-IR) spectrometry to profile the key metabolic changes and surface chemical responses of a Synechococcus strain, PCC 7002, during different growth regimes. This included testing various nitrogen (N) to phosphorous (P) ratios (both nitrogen and phosphorous dependent), nitrogen sources (nitrate, ammonium and urea) and growth stages (exponential, stationary, and death phase). FT-IR spectroscopy showed that varying the growth substrates on which Synechococcus cells were cultured resulted in differences in either the type or abundance of cellular exudates produced or a change in the cell wall components. Potentiometric titration data were modeled using three distinct proton binding sites, with resulting pKa values for cells of the various growth conditions in the ranges of 4.96–5.51 (pKa1), 6.67–7.42 (pKa2) and 8.13–9.95 (pKa3). According to previous spectroscopic studies, these pKa ranges are consistent with carboxyl, phosphoryl, and amine groups, respectively. Comparisons between the titration data (for the cell surface) and FT-IR spectra (for the average cellular changes) generally indicate (1) that the nitrogen source is a greater determinant of ligand concentration than growth phase, and (2) that phosphorus limitation has a greater impact on Synechococcus cellular and extracellular properties than does nitrogen limitation. Taken together, these techniques indicate that nutritional quality during cell growth can noticeably influence the expression of cell surface ligands and their measurable densities. Given that cell surface charge ultimately affects metal adsorption, our results suggest that the cycling of metals by Synechococcus cells in the oceans may vary regionally.

Hyaluronidase decreases neutrophils infiltration to the inflammatory site.

To evaluate the in vivo anti-inflammatory potential of bovine hyaluronidase (HYAL) using two different models of acute inflammation. Air pouches were produced in the dorsal subcutaneous of mice and injected with phosphate saline solution or HYAL. The antiinflammatory action of HYAL was evaluated in carrageenan (Cg)-inflamed air pouches. After 4 and 24h the cellular influx, protein exudation, cytokines and lipid mediators were evaluated. The action of HYAL on the rolling and adhesion of leukocytes was investigated in the LPS-stimulated mesenteric microcirculation by intravital microscopic. Treatment with HYAL reduced the cellular influx and protein exudation in non-inflamed and inflamed air pouches. HYAL treatment of Cg-inflamed air pouch reduced the production of tumor necrosis factor-alpha (TNF-α), interleukin-8 (IL-8), leukotriene B4 (LTB4) and LTC4, whereas prostaglandins E2 (PGE2) and D2 (PGD2) concentrations were unchanged. Histological analyses showed that HYAL administration diminished cell infiltration in the air-pouch lining. In LPS-stimulated mesenteric microcirculation, HYAL usage decreased rolling and adhesion of leukocytes, but did not affect the blood vessels diameters. The results demonstrate that HYAL inhibited cellular recruitment, edema formation and pro-inflammatory mediators production, resulting in decreased adherence of leukocytes to blood vessels and tissue infiltration. Our data suggest that HYAL may be considered an effective candidate to ameliorate acute inflammation.

Urinary uroplakin expression in cyclophosphamide-induced rat cystitis model.

Cyclophosphamide (CYP) induces urothelial injury and causes excretion of cellular exudates at 24 h, followed by rapid restoration at 72 h. We investigated the role of urinary uroplakin II (UPII) levels in a CYP-induced cystitis model. For the purpose of this study, 10 controls and 26 CYP-injected female Sprague Dawley rats were killed at 24 h and 72 h postinjection. The vesical weight, severity of hematuria, and expression of UPII in the urinary bladder and urine were measured. CYP decreased the level of vesical UPII messenger RNA at 24 h, followed by rapid recovery at 72 h. Contrary to the negligible levels of urinary UPII and hematuria in controls, CYP treatment abruptly increased the excretion of urinary UPII at 24 h. The excretion had subsided at 72 h. Similarly, severe hematuria was observed at 24 h, with improvement at 72 h. However, some rats still exhibited hematuria at 72 h. CYP caused increase in vesical weight. The vesical weight at 24 h after CYP injection was negatively correlated with the vesical UPII level. Rats with significant hematuria demonstrated higher urinary UPII levels than those with insignificant hematuria. Vesical UPII could be an important barrier for early CYP-related injury, while the levels of urinary UPII may be associated with the severity of hematuria during dynamic periods in the urothelium.

Pathological investigation of bovine lungs in naturally acquiredPasteurella multocidainfection by immunohistlogical technique

The aim of the study was to determine Pasteurella multocida antigen using immunohistochemistry staining of formalin fixed paraffin embedded tissue in pneumonic lung of bovine in naturally acquired infection. Further, the attempts were to describe the different pathological processes in causation of disease in the involved lungs. For this purpose 87 cattle and buffaloes diagnosed at necropsy with pneumonic lesions categorized according to distribution of lesion grossly and on the basis of cellular infiltration and exudation on microscopically were assessed. The macroscopic finding in 87 lungs, in which pneumonic lesions distributed mainly were in right cranial (35.63%) and in combination of right, left cranial and ventral (24.13%) lobes. Pneumonic lesions were microscopically classified as fibrinous bronchopneumonia (25.28%), catarrhal purulent bronchopneumonia (18.39%), purulent necrotic bronchopneumonia (14.94%), interstitial bronchopneumonia (12.64%), interstitial pneumonia (7.24%), necrotic fibrinous purulent pneumonia (8.04%) and alveolar haemorrhages (3.44%). Immunohistochemical staining against Pasteurella multocida antigen detected in 27 (31.03%) cases and high IHC scoring based on distribution and intensity of antigen were recorded in fibrinous broncho pneumonia and fibrino necrotic purulent pneumonia. The variations of bronchopneumonic lesion recorded in the present cases may possibly a varying susceptibility of individual and or complication of other bacterial and viral infection singly or concomitantly. Thus the present study provides a descriptive pathological process involved with Pasteurella multocida infection supported with detailed IHC scoring in cross sectional natural cases of infection in bovine that can be useful to assess comparative pathological process in relation to other causative agents of pneumonia in bovine.

Establishment of spiroplasma-infected hemocytes as an in vitro laboratory culture model of Chinese mitten crab Eriocheir sinensis

Spiroplasma is a novel pathogen of commercially exploited crustaceans. To more full clarify its pathogenic mechanism at the molecular level in vitro, a spiroplasma-infected hemocytes model was developed as described here, using a modified method of hemocytes culture from the Chinese mitten crab Eriocheir sinensis. It has been standardized by employing L-15 growth medium supplemented with 15% fetal bovine serum along with 0.15% glucose, 0.75% NaCl, antibiotics (100Uml−1 penicillin, 100Uml−1 streptomycin) and a suitable pH of 7.20–7.40, incubated at 28°C without the requirement for 5% carbon dioxide. Cytopathic effects of Spiroplasma eriocheiris in the cultures, including cell debris and cellular exudates, were observed as early as 36h post-inoculation. The green fluorescent dye Alex-488 was used as an immunoflourescence marker of S. eriocheiris to study its adhesion to, and infection of, the host cell. At about 24-h post-inoculation, a large number of spiroplasmas were observed infecting the host hemocytes cells, which became slug-like and widely distributed in the culture. Intracellular inclusion bodies containing spiroplasmas, and a large number of free spiroplasmas released from the ruptured cells, were observed using transmission electron microscopy. All the results show that S. eriocheiris can invade E. sinensis hemocytes in vitro, and this can provide a significant step forward toward further study of the relationship between the novel pathogen spiroplasma and its hosts in laboratory experimental studies.

Trichodesmium-derived dissolved organic matter is a source of nitrogen capable of supporting the growth of toxic red tide Karenia brevis

Dissolved organic nitrogen (DON) produced by the nitrogen-fixer Trichodesmium sp. has the potential to serve as a nitrogen source for the red tide dinoflagellate Karenia brevis. Dis- solved organic matter (DOM) from laboratory cultures of Trichodesmium sp. was isolated, concen- trated and then supplied as a nutrient source to K. brevis cells collected from the Gulf of Mexico. K. brevis abundance increased immediately after Trichodesmium sp. cellular exudate (TCE) addition, allowing the population to double within the first 24 h. There was rapid and complete utilization of the TCE DON as well as ~89% of the TCE dissolved organic phosphorus (DOP). Additionally, ter- minal restriction fragment length polymorphism (TRFLP) was used to assess the bacterial commu- nity response to the addition of TCE . The number of bacterial operational taxonomic units (OTUs) initially increased after the TCE DOM addition, but decreased as K. brevis reached its maximum abundance. Electrospray ionization mass spectrometry (ESI-MS) and Fourier transform ion cy- clotron resonance mass spectrometry (FT-ICR MS) were used to chemically characterize the DOM. Approximately 25% of compounds disappeared within the first 24 h, corresponding to the greatest increase in K. brevis abundance. Using FT-ICR MS, 391 DON and 219 DOP potentially bioavailable compounds were characterized. The bioavailable DON compounds were highly re- duced and 44% had molar ratios indicative of lipid or protein-like compounds. The changes in DON concentration and compound composition show that Tricho desmium sp. provides a sufficient source of nitrogen to directly or indirectly support K. brevis blooms.

Assessment of tolerance of willows to saline soils through electrical impedance measurements

One-year-old potted clone plants of four willow species (Salix matsudana × alba, S. babylonica, S. psammophila and S. cheilophila) were cultivated and irrigated with saline solutions of different concentrations, while their electrical impedance spectroscopy (EIS) parameters and other physical parameters were monitored. The results indicate i) that under salt stress, height and basal diameter of all species are inhibited, and ii) that relative conductivity of cellular exudates increases while intracellular resistance (ri) and extracelluar resistance (re) drop. Both ri and re were positively correlated with height growth and basal diameter while they were significantly and negatively correlated with electric conductivity. The concentration of Na+ in the shoots of willows was negatively correlated with both ri and re, whereas the concentration of K+ in the shoots was positively correlated with both ri and re. Hence, electrical impedance spectroscopy is a reliable tool for evaluating the capacity of willow species for tolerance to saline soils, with ri as the most accurate parameter.

Invited Commentary

Plastic bronchitis after Fontan completion is a known but difficult complication to treat. The onset usually denotes a failing Fontan, although Griffiths and colleagues [1Griffiths E.R. Kaza A.K. Wyler von Ballmoos M.C. et al.Evaluating failing Fontans for heart transplantation: predictors of death.Ann Thorac Surg. 2009; 88: 558-564Abstract Full Text Full Text PDF PubMed Scopus (141) Google Scholar] had shown the occurrence of plastic bronchitis in the group of Fontan with preserved ventricular function as opposed to those who have failed ventricular pump. There is also a close relation to other exudative complications, such as protein-losing enteropathy, and denotes a failing protoplasm not tolerating this Fontan connection resulting in exudative lesions [2Siulvilairat S. Cabalka A.K. Cetta F. Grogan M. Hagler D.J. O'Leary P.W. Protein-losing enteropathy after the Fontan operation: associations and predictors of clinical outcome.Congent Heart Dis. 2008; 3: 262-268Crossref PubMed Scopus (40) Google Scholar]. Grutter and colleagues [3Grutter G. Di Carlo D. Gandolfo F. et al.Plastic bronchitis after extracardiac Fontan operation.Ann Thorac Surg. 2012; 94: 860-864Abstract Full Text Full Text PDF PubMed Scopus (31) Google Scholar] presented their experience with plastic bronchitis in four patients. Although the group is small, all of them went through almost a similar course of events with chylothorax and requirement of coil embolization for collaterals, and all of them had preserved ventricular function. They had attempted various medical measures to treat the intractable plastic bronchitis with success in two of them, with both waiting to have transplantation. The other two died because of either the condition itself or complications in the process of managing it. I congratulate the authors for an excellent commentary on this condition, covering various pathogenetic mechanism and treatment options available. As mentioned in the article, casts of plastic bronchitis can be of two types, and acellular casts are common in failing Fontan patients. It is rare to see cellular elements unless there is associated bronchial anomaly, although all patients in this study group had mixed casts and two of them had bronchopulmonary disease in the form of malacia or obstructive airway disease. Whether this could have helped in the resolution of cast formation on medical management is difficult to ascertain, but one has to be careful in interpreting these, as quite often patients with extensive cast formation would also have significant impact on pulmonary function resulting in cellular exudates. Attempts have been made to clear the casts by instrumentation with mixed results. Intractable casts in the airway is difficult to manage, and authors have rightly sequenced various medical management including aerosols, pulmonary vasodilators, and tissue plasminogen activators [4Nayar S. Parmar R. Kulkarni S. Cherian K.M. Treatment of plastic bronchitis.Ann Thorac Surg. 2007; 83: 1884-1886Abstract Full Text Full Text PDF PubMed Scopus (14) Google Scholar]. Fenestration of Fontan circulation has a definitive role in reducing the incidence of exudative lesions but its efficacy in reducing the cast formation after its onset is a matter of debate. Role of transplantation after the onset of plastic bronchitis offers again mixed results in terms of resolution of further cast formation [5Gamba A. Merlo M. Fiocchi R. et al.Heart transplantation in patients with previous Fontan operations.J Thorac Cardiovasc Surg. 2004; 127: 555-562Abstract Full Text Full Text PDF PubMed Scopus (103) Google Scholar], although one would expect otherwise. Plastic Bronchitis After Extracardiac Fontan OperationThe Annals of Thoracic SurgeryVol. 94Issue 3PreviewWe discuss 4 cases of plastic bronchitis (PB) after Fontan procedure observed at our Institution, with the aim to identify an effective treatment and possible factors favoring the onset of PB. Plastic bronchitis is an uncommon disease characterized by recurrent formation of large pale bronchial casts obstructing the tracheobronchial tree. The treatment includes inhaled or systemic steroids, aerosolized mucolytics, bronchoscopic lavage, direct bronchoscopic extraction and, in few reports, aerosolized fibrinolytic and pulmonary vasodilators. Full-Text PDF

Classification of circulating hemocytes from the red swamp crayfish Procambarus clarkii and their susceptibility to the novel pathogen Spiroplasma eriocheiris in vitro

Hemocytes from the red swap crayfish Procambarus clarkii were classified into three subpopulations: hyalinocytes (H), semigranulocytes (SG) and granulocytes (G) by morphologic observation and flow cytometry (FCM). The primary hemocyte culture was then established for studies on the in vitro propagation of Spiroplasma eriocheiris isolated from naturally infected P. clarkii. Grace's insect medium supplemented with 15% fetal bovine serum (FBS), along with 100Uml−1 penicillin, 100μgml−1 streptomycin, with a final pH of 7.2–7.4, incubated at 28°C, supported the best survival in primary cultures. However, the granulocytes dehisced rapidly in culture medium, potentially impacting the survival of the other cell types. A two-step density gradient centrifugation with Percoll was developed to separate the hemocytes. When cultured separately, hyalinocytes and semigranulocytes maintained higher viability (>75%) after 16days of incubation compared with granulocytes, which degraded over 2–6days. After a challenge with S. eriocheiris, cytopathic effects (CPE) of the cultured hemocytes were observed as early as 48h post-inoculation, and as the infection progressed, CPE became more apparent, with cell debris and cellular exudates in inoculated cultures. Cell lysis was noticeable within 60h after challenging. A quantitative real-time RT-PCR was conducted to detect the immune responses during the challenging process at 2h, 4h, 8h, 10h, 24h, 48h and 60h, respectively. Clear time-dependent expression patterns of the peroxinectin gene (referred as Pcpxin), recently isolated from the crayfish hemocytes, and heat shock protein 70 (HSP70) gene were observed after S. eriocheiris challenge. The results above should be helpful in promoting research with S. eriocheiris, including elucidation of pathogenesis, host pathogen interaction and the defense mechanisms, and ultimately lead to prevention of this crustacean disease.

Permissive and Protective Factors Associated With Presence, Level, and Longitudinal Pattern of Cervicovaginal HIV Shedding

Cervicovaginal HIV level (CV-VL) influences HIV transmission. Plasma viral load (PVL) correlates with CV-VL, but discordance is frequent. We evaluated how PVL, behavioral, immunological, and local factors/conditions individually and collectively correlate with CV-VL. CV-VL was measured in the cervicovaginal lavage fluid (CVL) of 481 HIV-infected women over 976 person-visits in a longitudinal cohort study. We correlated identified factors with CV-VL at individual person-visits and detectable/undetectable PVL strata by univariate and multivariate linear regression and with shedding pattern (never, intermittent, persistent ≥3 shedding visits) in 136 women with ≥3 visits by ordinal logistic regression. Of 959 person-visits, 450 (46.9%) with available PVL were discordant, 435 (45.3%) had detectable PVL with undetectable CV-VL, and 15 (1.6%) had undetectable PVL with detectable CV-VL. Lower CV-VL correlated with highly active antiretroviral therapy (HAART) usage (P = 0.01). Higher CV-VL correlated with higher PVL (P < 0.001), inflammation-associated cellular changes (P = 0.03), cervical ectopy (P = 0.009), exudate (P = 0.005), and trichomoniasis (P = 0.03). In multivariate analysis of the PVL-detectable stratum, increased CV-VL correlated with the same factors and friability (P = 0.05), while with undetectable PVL, decreased CV-VL correlated with HAART use (P = 0.04). In longitudinal analysis, never (40.4%) and intermittent (44.9%) shedding were most frequent. Higher frequency shedders were more likely to have higher initial PVL [odds ratio (OR) = 2.47/log10 increase], herpes simplex virus type 2 seropositivity (OR = 3.21), and alcohol use (OR = 2.20). Although PVL correlates strongly with CV-VL, discordance is frequent. When PVL is detectable, cervicovaginal inflammatory conditions correlate with increased shedding. However, genital shedding is sporadic and not reliably predicted by associated factors. HAART, by reducing PVL, is the most reliable means of reducing cervicovaginal shedding.

Primary hemocyte culture of the freshwater prawn Macrobrachium rosenbergii and its susceptibility to the novel pathogen spiroplasma strain MR-1008

Primary culture of hemocyte from the giant freshwater prawn, Macrobrachium rosenbergii, was established for studies on the in vitro propagation of the novel nature pathogen spiroplasma MR-1008. In this context, a modified method of hemocyte culture from this crustacean has been standardized by employing Leibovitz-15(L-15) growth medium supplemented with 15% Fetal Bovine Serum (FBS) along with 0.1% glucose, 0.5% NaCl and antibiotics (100Uml−1 penicillin, 100Uml−1 streptomycin,1μgml−1 amphotericin b) and a suitable pH of 7.20–7.40. In this medium, the hemocytes can be subcultured twice, including significant cell proliferation and viability of up to 12days. Susceptibility of the hemocytes was investigated by challenging with spiroplasma MR-1008. Cytopathic effects (CPE) were observed as early as 48h post-inoculation; and as the infection progressed, CPE became more apparent, with cell debris and cellular exudates present in inoculated cultures. Cell lysis was noticeable within 60h after infection. A quantitative real-time RT-PCR was conducted to detect the immune related gene expression during the infection process at 2, 4, 12, 24, 48, and 60h, respectively. The expression levels of lipopolysaccharide and β-1,3-glucan-binding protein (LGBP), prophenoloxidase (proPO), α-2-macroglobulin (α2M) and copper/zinc SOD (Cu/Zn-SOD) genes in hemocytes of M. rosenbergii demonstrated that these immune genes were induced by challenge with spiroplasma MR-1008. The primary hemocyte culture can be used to investigate the interaction between host and pathogen in vitro, promote enhanced understanding of spiroplasma MR-1008, and ultimately lead to prevention this crustacean disease.

Phytoplankton Composition and Environmental Conditions of the Mucilage Event in the Sea of Marmara

The composition and abundance of phytoplankton and the corresponding environmental conditions were investigated during a mucilage event (October 2007-February 2008) in the Sea of Marmara. The mucilage producers Gonyaulax fragilis, Skeletonema costatum, and Cylindrotheca closterium were identified as abundant species. Thallassiosira rotula was also identified in large numbers. The maximum number of G. fragilis was observed at 83,600 cells L^{-1} in November 2007 during the first sampling occasion on the surface layer of İzmit Bay, and T. rotula was the most abundant diatom species, with 131,040 cells L^{-1} in the same period. G. fragilis was recorded at 96,250 cells L^{-1} in the dense mucilage-containing water samples collected from Değirmendere (İzmit Bay) in January 2008, and C. closterium was the dominant (161,250 cells L^{-1}) diatom species in the same sample. Species diversity values (H'_{log2}) increased from November to February, displaying maximum values of 2.5-3.5 in February at almost all stations (depths of 0.5 and 10 m), caused by the balanced increase of diatom species and their individual numbers in the total phytoplankton abundance. The surface layer waters of İzmit Bay exhibited severely low nitrogen to phosphorus ratio (N:P) values (0.1-14.4) compared to the Redfield ratio (16), which could be supported by the fact that the limiting nutrient for the Sea of Marmara is nitrogen. Even though there is a lack of data from before the mucilage period, the data obtained during the lifespan of the event indicated that a mixture of several phytoplankton species might have played a key role in the mucilage formation. The high organic carbon content of the mucilage (24% org-C) and the surrounding waters support the possibility that the event could have been related to organically rich cellular exudates of phytoplankton.

Microbial reduction of ferrous arsenate: Biogeochemical implications for arsenic mobilization

In reduced aqueous environments, the presence of As in solution is a function of both biotic and abiotic mechanisms. Recent studies have demonstrated a significant release of As(III) through the microbial reduction of dissolved and mineral-bound As(V), which raises health concerns when the greater comparative mobility and toxicity of As(III) is considered. These release mechanisms do not operate in isolation but occur in concert with a number of removal processes, including secondary mineralization and sorption to other natural substrates. Thermodynamic and applied experimental studies have shown that ferrous arsenates, such as symplesite [Fe(II){sub 3}(As(V)O{sub 4}){sub 2} {center_dot} 8H{sub 2}O], may provide a significant sink for Fe(II) and As(V). In this study, the stability of a representative ferrous arsenate phase in the presence of the arsenate-reducing bacterium Shewanella sp. strain ANA-3 is examined. The reduction of ferrous arsenate by ANA-3 results in the release of aqueous As(III) and, subsequently, the progressive nucleation of a biogenic ferrous arsenite phase proximal to the microbial cells. The valence states of secondary solid-phase products were verified using X-ray absorption spectroscopy (XAS). Electron microscopy reveals that nucleation occurs on cellular exudates which may imply a role of extracellular reduction through c-type cytochromes as investigated in recentmore » literature. These observations provide new insights into the reduction mechanisms of ANA-3 and the biogeochemical cycling of As(III) in natural systems.« less