torpedo Dotaz Zobrazit nápovědu
Úvod: Torpédo makulopatia je vzácna, vrodená ložisková lézia sietnice. Klinický obraz je typický unilaterálnou, ohraničenou, oválnou, hypopigmentovou léziou v inferotemporálnej časti makuly. Vo väčšine prípadov sa lézia nachádza pozdĺž horizontálneho rafé, má tvar torpéda a nazálny okraj smeruje do foveoly. Diagnóza je stanovená na základe jej charakteristického tvaru, lokalizácie a nálezu na optickej koherentnej tomografii (OCT). Etiológia a patogenéza vzniku torpédo makulopatie je nejasná, ale predpokladá sa, že ide o vrodený defekt retinálneho pigmentového epitelu (RPE). Cieľom publikácie je poukázať na túto diagnózu a odprezentovať nález torpédo makulopatie u dospelej pacientky. Kazuistika: 30-ročná pacientka sa dostavila na rutinné očné vyšetrenie. Vyšetrenie očného pozadia pravého oka odhalilo inferotemporálne od fovey oválnu hypopigmentovú léziu veľkosti 1 priemeru disku, na ktorú nadväzovalo satelitné ložisko v rovnakej osi smerujúcej do foveoly. Na základe OCT, OCT angiografie, fundusautofluorescencie, odberu anamnézy, typického tvaru a lokality lézie bola pacientke diagnostikovaná torpédo makulopatia na pravom oku. Záver: Vo všeobecnosti je torpédo makulopatia asymptomatická, vrodená, benígna lézia sietnice. Väčšinou je náhodne diagnostikovaná pri vyšetrení očného pozadia. Ide o stabilný nález s minimálnym rizikom poškodenia zrakových funkcií, ktorý nevyžaduje žiadnu liečbu. Napriek tomu sa vzhľadom na malé riziko vzniku choroidálnej neovaskulárnej membrány odporúča sledovanie pacientov raz ročne. Na túto diagnózu je nutné myslieť pri náleze unilaterálneho hypopigmentového ložiska inferotemporálne od fovey a v rámci diferenciálnej diagnostiky ho odlíšiť od chorioretinálnej atrofie, jazvy, kolobómu, viteliformnej dystrofie, či iných lézií RPE.
Aim: Torpedo maculopathy is an incidental, congenital retinal lesion. The typical clinical finding is a unilateral, symmetric, oval, hypopigmented lesion in the inferotemporal macula. In most cases, the lesion is along the horizontal raphe, is torpedo-shaped, and the nasal edge is directed into the foveola. The diagnosis is determined on the basis of its characteristic shape, localization and findings on optical coherence tomography (OCT). The etiology and pathogenesis of torpedo maculopathy is unclear, but it is believed to be a congenital defect of the retinal pigment epithelium (RPE). The aim of this publication is highlight this diagnosis and to present an incidental finding of torpedo maculopathy in an adult patient. Case report: A 30-year-old female patient reported for a routine eye examination. Fundus examination of the right eye revealed an oval hypopigmented lesion with a size of 1 disk diameter inferotemporally from the fovea, which was followed by a satellite lesion in the same axis directed into the foveola. Based on OCT, OCT angiography, fundus autofluorescence, and the typical shape and location of the lesion, the patient was diagnosed with torpedo maculopathy in the right eye. Conclusion: In general, torpedo maculopathy is an asymptomatic, congenital, benign retinal lesion, which is mostly diagnosed accidentally during a routine fundus examination. TM is non-progressive retinal finding with a minimal risk of deterioration of visual functions, which does not require any treatment. Nevertheless, due to the rare risk of a choroidal neovascular membrane, it is recommended to examine patients once a year. It is necessary to consider this diagnosis when a unilateral hypopigmented lesion is found inferotemporally from the fovea, and to distinguish it from chorioretinal atrophy, scar, vitelliform dystrophy, or other RPE lesions as part of the differential diagnosis.
- MeSH
- dospělí MeSH
- lidé MeSH
- nemoci retiny * diagnóza terapie MeSH
- optická koherentní tomografie metody MeSH
- retina patologie MeSH
- retinální pigmentový epitel patologie MeSH
- výsledek terapie MeSH
- Check Tag
- dospělí MeSH
- lidé MeSH
- ženské pohlaví MeSH
- Publikační typ
- kazuistiky MeSH
Chloromyxum leydigi Mingazzini, 1890, the type species of Chloromyxum Mingazzini, 1890, is redescribed based on material found in the gall bladder of the cartilaginous fish Torpedo marmorata Risso collected from the Portuguese Atlantic coast and its sporogonic development is described. Plasmodia and mature spores were floating free in the bile. Plasmodia are polysporic and highly polymorphic in shape and organization. Mature spores are spherical to subspherical with a pointed anterior end, measuring 12.3 +/- 0.5 microm in length and 9.0 +/- 0.5 microm in width. The spore wall is composed of two asymmetric shell valves, each bearing 4-5 elevated surface ridges. A bundle of 40-50 tapering caudal filaments extends from the basal portion of the shell valves. Four pyriform equal-sized polar capsules, measuring about 5.3 x 3.2 microm, are observed at the same level in the anterior pole of the spores, each containing a polar filament coiled in 8-9 (rarely 10) turns. Spore morphology, tissue tropism, host species and sequences of the SSU rRNA gene supported species identification. Since its discovery, this species has been dubiously reported from several cartilaginous hosts, namely due to the poor description of its features.
- MeSH
- Myxozoa klasifikace ultrastruktura MeSH
- nemoci ryb parazitologie MeSH
- nemoci žlučníku parazitologie veterinární MeSH
- parazitární nemoci u zvířat parazitologie MeSH
- Torpedo * MeSH
- žlučník parazitologie MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
RNase J1 is the major 5'-to-3' bacterial exoribonuclease. We demonstrate that in its absence, RNA polymerases (RNAPs) are redistributed on DNA, with increased RNAP occupancy on some genes without a parallel increase in transcriptional output. This suggests that some of these RNAPs represent stalled, non-transcribing complexes. We show that RNase J1 is able to resolve these stalled RNAP complexes by a "torpedo" mechanism, whereby RNase J1 degrades the nascent RNA and causes the transcription complex to disassemble upon collision with RNAP. A heterologous enzyme, yeast Xrn1 (5'-to-3' exonuclease), is less efficient than RNase J1 in resolving stalled Bacillus subtilis RNAP, suggesting that the effect is RNase-specific. Our results thus reveal a novel general principle, whereby an RNase can participate in genome-wide surveillance of stalled RNAP complexes, preventing potentially deleterious transcription-replication collisions.
- MeSH
- Bacillus subtilis enzymologie genetika MeSH
- bakteriální proteiny metabolismus MeSH
- bakteriální RNA genetika metabolismus MeSH
- DNA řízené RNA-polymerasy metabolismus MeSH
- exoribonukleasy metabolismus MeSH
- genetická transkripce MeSH
- messenger RNA genetika metabolismus MeSH
- regulace genové exprese u bakterií MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
During the first step of gene expression, RNA polymerase (RNAP) engages DNA to transcribe RNA, forming highly stable complexes. These complexes need to be dissociated at the end of transcription units or when RNAP stalls during elongation and becomes an obstacle ('sitting duck') to further transcription or replication. In this review, we first outline the mechanisms involved in these processes. Then, we explore in detail the torpedo mechanism whereby a 5'-3' RNA exonuclease (torpedo) latches itself onto the 5' end of RNA protruding from RNAP, degrades it and upon contact with RNAP, induces dissociation of the complex. This mechanism, originally described in Eukaryotes and executed by Xrn-type 5'-3' exonucleases, was recently found in Bacteria and Archaea, mediated by β-CASP family exonucleases. We discuss the mechanistic aspects of this process across the three kingdoms of life and conclude that 5'-3' exoribonucleases (β-CASP and Xrn families) involved in the ancient torpedo mechanism have emerged at least twice during evolution.
- MeSH
- Archaea genetika MeSH
- Bacteria genetika MeSH
- DNA řízené RNA-polymerasy metabolismus MeSH
- DNA metabolismus MeSH
- Eukaryota genetika MeSH
- exoribonukleasy metabolismus MeSH
- genetická transkripce MeSH
- vazba proteinů MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- přehledy MeSH
