scholarly journals Intestinal spirochetosis: first cases reported in Brazil and the use of immunohistochemistry as an aid in histopathological diagnosis

1996 ◽  
Vol 38 (1) ◽  
pp. 45-53 ◽  
Author(s):  
T. de Brito ◽  
Marina P. Sandoval ◽  
Ana G. Silva ◽  
R. C. Saad ◽  
W. Colaiacovo
Keyword(s):  
Disease Transmission ◽  
Treponema Pallidum ◽  
Surface Epithelium ◽  
Histopathological Diagnosis ◽  
Intestinal Spirochetosis ◽  
A Cell ◽  
Colon And Rectum ◽  
First Time ◽  
Brachyspira Aalborgi ◽  
Routine Stains

Colonization of the colon and rectum by intestinal spirochetes is detected for the first time in Brazil in 4 of 282 (1.41%) patients who had undergone sigmoidoscopy and/or colonoscopy with a histopathological diagnosis of chronic non specific-colitis. This frequency is probably understimated, since surgically obtained specimens were not considered in the present study. Histopathological diagnosis was performed using routine stains like hematoxylin-eosin which showed the typical, of 3-µm thick hematoxyphilic fringe on the brush border of the surface epithelium, and by silver stains like the Warthin-Starry stain. Immunohistochemical procedures using two, polyclonal, primary antibodies, one against Treponema pallidum and the other against Leptospira interrogans serovar copenhageni serogroup Icterohaemorrhagiae cross-reacted with spirochetal antigen/s producing a marked contrast of the fringe over the colonic epithelium, preserving the spiral-shaped morphology of the parasite. In one case with marked diarrhea, immunohistochemistry detected spirochetal antigen/s within a cell in an intestinal crypt, thus demonstrating that the infection can be more widely disseminated than suspected using routine stains. Immunohistochemical procedures, thus, greatly facilitate the histological diagnosis of intestinal spirochetosis and may contribute to a better understanding of the pathogenesis of the disease. Transmission and scanning electron microscopy performed in one case showed that the spirochete closely resembled the species designated as Brachyspira aalborgi.

scholarly journals 716. A Case of Symptomatic Intestinal Spirochetosis

2020 ◽  
Vol 7 (Supplement_1) ◽  
pp. S409-S409
Author(s):  
Zhi En Chan ◽  
Jasmine Chung Shimin
Keyword(s):  
Venereal Disease ◽  
Lower Abdominal Pain ◽  
Colonic Polyps ◽  
Local Context ◽  
Brachyspira Pilosicoli ◽  
16S Rna ◽  
Intestinal Spirochetosis ◽  
Mucous Discharge ◽  
Treatable Condition ◽  
Brachyspira Aalborgi

Abstract Background Intestinal spirochetosis (IS) is a condition caused by Brachyspira aalborgi and Brachyspira Pilosicoli. Its clinical significance has long been a point of contention with some debating that these spirochetes are simply colonic commensals. It is a condition that is more prevalent in developing nations as well as patients with HIV and the homosexual population. The epidemiology and prevalence of IS has not been studied in the local context. Methods We reviewed a case of a 37-year-old man who presented with a two month history of persistent lower abdominal pain, hematochezia, and increase in mucous discharge per rectum. He is sexually active with multiple male partners, and was previously treated for gonorrhea, chlamydia, and syphilis. His basic laboratory investigations were unremarkable, Venereal Disease Research Laboratory (VDRL) antibody and human immunodeficiency virus (HIV) screen were both non-reactive. Computed tomography of the abdomen was unremarkable. Endoscopic evaluation revealed multiple discrete ulcers measuring 1-2mm seen only in the rectum. Random biopsies of the cecum, ascending colon, transverse colon and descending colon showed mild acute colitis with IS. There was also mild to moderate acute proctitis in the rectum with spirochetes seen. 16s RNA gene sequencing of the biopsy specimen were confirmatory for Brachyspira aalborgi. Investigation findings. A: Discrete Ulcers found in rectum, B: Hemotoxylin and Eosin stained specimen showing proctitis, C: False brush Border appearance D: Spirochetes on Warthin Starry stain Results The patient received a 10 day course of metronidazole with complete resolution of his symptoms. Conclusion This case demonstrates the existence of a treatable condition that can be diagnosed with current available investigations for patients with similar symptoms. Recognising at risk populations can also raise clinical suspicion for this condition. Some studies have found associations between IS with development of colonic polyps and also certain colorectal cancers. Further studies on this treatable condition and its disease burden in the local context should be further explored. Disclosures All Authors: No reported disclosures

scholarly journals Characterization of a Novel Fructosyltransferase from Lactobacillus reuteri That Synthesizes High-Molecular-Weight Inulin and Inulin Oligosaccharides

2002 ◽  
Vol 68 (9) ◽  
pp. 4390-4398 ◽  
Author(s):  
S. A. F. T. van Hijum ◽  
G. H. van Geel-Schutten ◽  
H. Rahaoui ◽  
M. J. E. C. van der Maarel ◽  
L. Dijkhuizen
Keyword(s):  
Molecular Weight ◽  
High Molecular Weight ◽  
Lactobacillus Reuteri ◽  
Bacterial Strains ◽  
Potential Health ◽  
Isolation And Characterization ◽  
A Cell ◽  
Encoding Gene ◽  
First Time

ABSTRACT Fructosyltransferase (FTF) enzymes produce fructose polymers (fructans) from sucrose. Here, we report the isolation and characterization of an FTF-encoding gene from Lactobacillus reuteri strain 121. A C-terminally truncated version of the ftf gene was successfully expressed in Escherichia coli. When incubated with sucrose, the purified recombinant FTF enzyme produced large amounts of fructo-oligosaccharides (FOS) with β-(2→1)-linked fructosyl units, plus a high-molecular-weight fructan polymer (>107) with β-(2→1) linkages (an inulin). FOS, but not inulin, was found in supernatants of L. reuteri strain 121 cultures grown on medium containing sucrose. Bacterial inulin production has been reported for only Streptococcus mutans strains. FOS production has been reported for a few bacterial strains. This paper reports the first-time isolation and molecular characterization of (i) a Lactobacillus ftf gene, (ii) an inulosucrase associated with a generally regarded as safe bacterium, (iii) an FTF enzyme synthesizing both a high molecular weight inulin and FOS, and (iv) an FTF protein containing a cell wall-anchoring LPXTG motif. The biological relevance and potential health benefits of an inulosucrase associated with an L. reuteri strain remain to be established.

scholarly journals Macrophage Autophagy and Oxidative Stress: An Ultrastructural and Immunoelectron Microscopical Study

2011 ◽  
Vol 2011 ◽  
pp. 1-8 ◽  
Author(s):  
Ida Perrotta ◽  
Valentina Carito ◽  
Emilio Russo ◽  
Sandro Tripepi ◽  
Saveria Aquila ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Cell Death ◽  
Programmed Cell Death ◽  
Defense Mechanisms ◽  
Ultrastructural Localization ◽  
Microscopical Study ◽  
Beclin 1 ◽  
Cell Organelles ◽  
A Cell ◽  
First Time

The word autophagy broadly refers to the cellular catabolic processes that lead to the removal of damaged cytosolic proteins or cell organelles through lysosomes. Although autophagy is often observed during programmed cell death, it may also serve as a cell survival mechanism. Accumulation of reactive oxygen species within tissues and cells induces various defense mechanisms or programmed cell death. It has been shown that, besides inducing apoptosis, oxidative stress can also induce autophagy. To date, however, the regulation of autophagy in response to oxidative stress remains largely elusive and poorly understood. Therefore, the present study was designed to examine the ratio between oxidative stress and autophagy in macrophages after oxidant exposure (AAPH) and to investigate the ultrastructural localization of beclin-1, a protein essential for autophagy, under basal and stressful conditions. Our data provide evidence that oxidative stress induces autophagy in macrophages. We demonstrate, for the first time by immunoelectron microscopy, the subcellular localization of beclin-1 in autophagic cells.

scholarly journals Selection and Characterization of Rupintrivir-Resistant Norwalk Virus Replicon Cells In Vitro

2018 ◽  
Vol 62 (5) ◽  
Author(s):  
Mitsutaka Kitano ◽  
Myra Hosmillo ◽  
Edward Emmott ◽  
Jia Lu ◽  
Ian Goodfellow
Keyword(s):  
Reverse Genetics ◽  
Resonance Energy Transfer ◽  
Resonance Energy ◽  
Murine Norovirus ◽  
Norwalk Virus ◽  
Irreversible Inhibitor ◽  
Antiviral Compounds ◽  
A Cell ◽  
First Time

ABSTRACT Human norovirus (HuNoV) is a major cause of nonbacterial gastroenteritis worldwide, yet despite its impact on society, vaccines and antivirals are currently lacking. A HuNoV replicon system has been widely applied to the evaluation of antiviral compounds and has thus accelerated the process of drug discovery against HuNoV infection. Rupintrivir, an irreversible inhibitor of the human rhinovirus 3C protease, has been reported to inhibit the replication of the Norwalk virus replicon via the inhibition of the norovirus protease. Here we report, for the first time, the generation of rupintrivir-resistant human Norwalk virus replicon cells in vitro . Sequence analysis revealed that these replicon cells contained amino acid substitutions of alanine 105 to valine (A105V) and isoleucine 109 to valine (I109V) in the viral protease NS6. The application of a cell-based fluorescence resonance energy transfer (FRET) assay for protease activity demonstrated that these substitutions were involved in the enhanced resistance to rupintrivir. Furthermore, we validated the effect of these mutations using reverse genetics in murine norovirus (MNV), demonstrating that a recombinant MNV strain with a single I109V substitution in the protease also showed reduced susceptibility to rupintrivir. In summary, using a combination of different approaches, we have demonstrated that, under the correct conditions, mutations in the norovirus protease that lead to the generation of resistant mutants can rapidly occur.

Light as a Life Tool

2020 ◽  
pp. 58-81
Author(s):  
John Parrington
Keyword(s):  
Fluorescent Protein ◽  
Green It ◽  
Live Animal ◽  
New Science ◽  
Gene Coding ◽  
A Cell ◽  
Electron Microscopes ◽  
First Time ◽  
Protein Channels ◽  
The Brain

Visual light, and radiation of other frequencies, are highly important for scientific research. The first light microscopes made it possible for the first time to see that organisms from plants to humans are composed of cells. Electron microscopes have allowed scientists to study the structural components of cells in great detail, and even determine the shapes of individual proteins. Many lifeforms also use light to attract a mate or prey, or deter an attacker. Following the identification of the gene coding for the fluorescent protein that makes certain jellyfish glow green it has become possible to use this to genetically label proteins in a living cell, or even a live animal. This means that now the location of proteins in a cell can be determined exactly. A major recent step forward in neuroscience came with the discovery of protein channels in algae that conduct ions in response to light. By creating transgenic mice that have these proteins in their brain neurons, it is now possible to modulate the activity of these neurons by shining light into the brain though microscopic fibre optic cables. This new science of optogenetics allows neurons to be switched on or off experimentally. The optogenetic approach has been used to uncover the neural circuits involved in memory, pain and pleasure. In the future this technique might be used to treat physical pain or depression in people. Controversially, it might be also be misused, to supress memories, or even create completely false ones in people’s heads.

Electrophysiological and Anatomical Characterization of PDF-Positive Clock Neurons in the Intact Adult Drosophila Brain

2006 ◽  
Vol 95 (6) ◽  
pp. 3955-3960 ◽  
Author(s):  
Demian Park ◽  
Leslie C. Griffith
Keyword(s):  
Biological Rhythms ◽  
Cell Group ◽  
Resting Membrane Potential ◽  
Electrophysiological Properties ◽  
Drosophila Brain ◽  
A Cell ◽  
Locomotor Rhythms ◽  
Firing Properties ◽  
First Time

Daily biological rhythms in both prokaryotes and eukaryotes are controlled by circadian clocks. In Drosophila, there is a good basic understanding of both the molecular and anatomical components of the clock. In this study we directly measure, for the first time, electrophysiological properties and anatomy of individual filled large lateral PDF-positive clock neurons, a cell group believed to be involved in synchronization of the clock in constant conditions. We find that the large PDF-positive neurons are morphologically homogeneous and that their resting membrane potential is modulated both by the clock and by light inputs. Expression of a leak channel, dORK-ΔC, which has been shown to disrupt circadian locomotor rhythms, hyperpolarizes these neurons, and blocks firing. These data imply that the firing properties of large PDF neurons are both regulated by and critical for clock function.

scholarly journals Ultrastructural features of the uterus in the sexually immature ostrich (Struthio camelus) during periods of ovarian inactivity and activity

2007 ◽  
Vol 74 (3) ◽  
Author(s):  
M-C. Madekurozwa
Keyword(s):  
Secretory Granules ◽  
Columnar Epithelium ◽  
Surface Epithelium ◽  
Secretory Product ◽  
Ciliated Cells ◽  
Cell Type ◽  
Struthio Camelus ◽  
A Cell ◽  
Ciliated Epithelial Cells ◽  
Luminal Region

The ultrastructure of the surface epithelium and tubular glands of the uterus in the immature ostrich is described. In ostriches with inactive ovaries the uterus is lined by a non-ciliated simple columnar epithelium, with basally located heterochromatic nuclei. Scanning electron microscopy revealed that these non-ciliated cells have a dense microvillous cover. A simple columnar to pseudostratified columnar epithelium, comprised of non-ciliated and ciliated cells, lines the uterus in birds with active ovaries. The ciliated cells possess a wide luminal region, which contains a nucleus and various organelles. An accumulation of secretory granules was observed in the apical regions of the non-ciliated cells, as well as in a few ciliated cells. In addition to non-ciliated and ciliated cells, a cell type with rarefied cytoplasm was also identified. These cells appear to correspond to calcium secreting cells identified in other avian species. The results of this study indicate that, although uterine differentiation is present in immature ostriches with active ovaries, the production of secretory product appears to occur mainly in non-ciliated epithelial cells.

scholarly journals Functional Role of the PE Domain and Immunogenicity of the Mycobacterium tuberculosis Triacylglycerol Hydrolase LipY

2007 ◽  
Vol 76 (1) ◽  
pp. 127-140 ◽  
Author(s):  
Kanhu C. Mishra ◽  
Chantal de Chastellier ◽  
Yeddula Narayana ◽  
Pablo Bifani ◽  
Alistair K. Brown ◽  
...  
Keyword(s):  
Mycobacterium Tuberculosis ◽  
Humoral Response ◽  
Host Immune System ◽  
Functional Roles ◽  
Triacylglycerol Hydrolase ◽  
Immunodominant Antigen ◽  
Surface Localization ◽  
A Cell ◽  
First Time

ABSTRACT PE and PPE proteins appear to be important for virulence and immunopathogenicity in mycobacteria, yet the functions of the PE/PPE domains remain an enigma. To decipher the role of these domains, we have characterized the triacylglycerol (TAG) hydrolase LipY from Mycobacterium tuberculosis, which is the only known PE protein expressing an enzymatic activity. The overproduction of LipY in mycobacteria resulted in a significant reduction in the pool of TAGs, consistent with the lipase activity of this enzyme. Unexpectedly, this reduction was more pronounced in mycobacteria overexpressing LipY lacking the PE domain [LipY(ΔPE)], suggesting that the PE domain participates in the modulation of LipY activity. Interestingly, Mycobacterium marinum contains a protein homologous to LipY, termed LipYmar, in which the PE domain is substituted by a PPE domain. As for LipY, overexpression of LipYmar in Mycobacterium smegmatis significantly reduced the TAG pool, and this was further pronounced when the PPE domain of LipYmar was removed. Fractionation studies and Western blot analysis demonstrated that both LipY and LipY(ΔPE) were mainly present in the cell wall, indicating that the PE domain was not required for translocation to this site. Furthermore, electron microscopy immunolabeling of LipY(ΔPE) clearly showed a cell surface localization, thereby suggesting that the lipase may interact with the host immune system. Accordingly, a strong humoral response against LipY and LipY(ΔPE) was observed in tuberculosis patients. Together, our results suggest for the first time that both PE and PPE domains can share similar functional roles and that LipY represents a novel immunodominant antigen.

scholarly journals First detection of a Vssc allele V1016G conferring a high level of insecticide resistance in Aedes albopictus collected from Europe (Italy) and Asia (Vietnam), 2016: a new emerging threat to controlling arboviral diseases

2019 ◽  
Vol 24 (5) ◽  
Author(s):  
Shinji Kasai ◽  
Beniamino Caputo ◽  
Takashi Tsunoda ◽  
Tran Chi Cuong ◽  
Yoshihide Maekawa ◽  
...  
Keyword(s):  
Insecticide Resistance ◽  
Aedes Albopictus ◽  
Disease Transmission ◽  
Pyrethroid Resistance ◽  
Virus Disease ◽  
Mosquito Species ◽  
Geographical Regions ◽  
Arboviral Diseases ◽  
High Level ◽  
First Time

Introduction Aedes albopictus (Skuse) is an important vector of arboviral diseases, including dengue, chikungunya and Zika virus disease. Monitoring insecticide resistance and mechanisms by which the mosquito develops resistance is crucial to minimise disease transmission. Aim To determine insecticide resistance status and mechanisms in Ae. albopictus from different geographical regions. Methods We sampled 33 populations of Ae. albopictus from Asia, Europe and South America, and tested these for susceptibility to permethrin, a pyrethroid insecticide. In resistant populations, the target site for pyrethroids, a voltage-sensitive sodium channel (Vssc) was genotyped. Three resistant sub-strains, each harbouring a resistance allele homozygously, were established and susceptibilities to three different pyrethroids (with and without a cytochrome P450 inhibitor) were assayed. Results Most populations of Ae. albopictus tested were highly susceptible to permethrin but a few from Italy and Vietnam (4/33), exhibited high-level resistance. Genotyping studies detected a knockdown resistance (kdr) allele V1016G in Vssc for the first time in Ae. albopictus. Two previously reported kdr alleles, F1534C and F1534S, were also detected. The bioassays indicated that the strain homozygous for the V1016G allele showed much greater levels of pyrethroid resistance than other strains harbouring F1534C or F1534S. Conclusion The V1016G allele was detected in both Asian and Italian Ae. albopictus populations, thus a spread of this allele beyond Italy in Europe cannot be ruled out. This study emphasises the necessity to frequently and regularly monitor the V1016G allele in Ae. albopictus, particularly where this mosquito species is the main vector of arboviruses.

scholarly journals Langerhans Cells Express IL-17A in the Epidermis of Chromoblastomycosis Lesions

2017 ◽  
Vol 2 (2) ◽  
pp. 1-8 ◽  
Author(s):  
Aline Alves de Lima Silva ◽  
Paulo Ricardo Criado ◽  
Ricardo Spina Nunes ◽  
Luciane Kanashiro-Galo ◽  
Maria Irma Seixas Duarte ◽  
...  
Keyword(s):  
Langerhans Cells ◽  
Subcutaneous Tissue ◽  
Innate Immune ◽  
Lesion Group ◽  
Control Group ◽  
Histopathological Diagnosis ◽  
Immunofluorescence Technique ◽  
Double Immunostaining ◽  
First Time

Chromoblastomycosis (CBM) is a chronic fungal infection that affects skin and subcutaneous tissue, and little is known about the immunological aspects of such lesions. We have previously described the high expression of IL-17 in this group. Understanding the innate immune response of patients with CBM would improve the knowledge of its immunopathogenesis and contribute to the most appropriate therapies. Nineteen biopsies of verrucous form were obtained from patients with clinical and histopathological diagnosis of CBM, without treatment. This was done with a double immunostaining with conventional immunohistochemistry and immunofluorescence technique as well as confocal microscopy to detect Langerin and IL-17 expression. All of the specimens that were analyzed showed expression of Langerin in the epidermis - the same as the control group. However, only the CBM group presented cells expressing CD207 in the dermis. Interestingly, the coexpression of IL-17 and Langerin was visualized along the epidermis and dermis in 100% of the lesion group. We demonstrated for the first time in situ coexpression of IL-17 and Langerin (CD207) in epidermal cells of patients with CBM and speculated on their role as IL-17-producing cells or whether they could be a new subpopulation of dendritic cells distinct from Langerhans cells.

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