Dishing out mini-brains: Current progress and future prospects in brain organoid research

AbstractThe ability to model human brain development in vitro represents an important step in our study of developmental processes and neurological disorders. Protocols that utilize human embryonic and induced pluripotent stem cells can now generate organoids which faithfully recapitulate, on a cell-biological and gene expression level, the early period of human embryonic and fetal brain development. In combination with novel gene editing tools, such as CRISPR, these methods represent an unprecedented model system in the field of mammalian neural development. In this review, we focus on the similarities of current organoid methods to in vivo brain development, discuss their limitations and potential improvements, and explore the future venues of brain organoid research

Dijagnostička vrijednost širokopojasne timpanometrije u pacijenata oboljelih od otoskleroze [Diagnostic value of wideband tympanometry in patients with otosclerosis]

INTRODUCTION: Wideband tympanometry is a new technique for assessing middle ear transfer function in which probe tone of 226 Hz is replaced by a probe “click” that covers the 226 to 8000 Hz range. It is still not clear if otosclerosis could be diagnosed based on wideband tympanometry findings. ----- METHODS: Longitudinal prospective study included 50 patients with surgically confirmed otosclerosis and 50 normal hearing persons. ----- RESULTS: Significant differences between EA in otosclerosis and EA in the control group were found at frequency range 343 Hz-3268 Hz with EA lower in otosclerosis and at frequency range 4238 Hz -7550 Hz with EA higher in otosclerosis than in control group. ROC analysis showed that the best sensitivity and specificity in differentiating otosclerosis from healthy subjects was obtained by observing the average EA at frequency range > 500Hz ≤ 1000Hz. There was no correlation between EA and postoperative hearing improvement. ----- CONCLUSIONS: The results of our study suggest that wideband timpanometry may be useful in the diagnosis of otosclerosis, but it can not replace pure tone audiometry in assessing the degree of hearing impairment and the expected postoperative improvement

Pronađe 40. Mersenov prost broj!

Prilog prikazuje potragu za velikim prostim brojevima. Govori se o GIMPS projektu..

Donald Ervin Knuth

Prikaz oca informatičkih znanosti i TeX-a

Hearing loss in young boy caused by cerebellar stroke- case report

Sudden sensorineural hearing loss (SSHL) and vertigo in children are relatively uncommon. The assessment of acute vertigo in childhood is often challenging. Fortunately, a central cause is rare. The incidence of ischemic strokes in children is given as six cases in 1 000 000 children per year. The aim of this report is to present a rare case of vertigo and hearing loss in young patient developed after cerebellar ischemia. A 15-yearold boy presented in emergency ENT department with symptoms of dizziness, right sided hearing loss and tinnitus. Two days prior to the visit, he participated in a wrestling training, after which he started to feel nauseous, developed dizziness without rotatory component and mild hearing loss in right ear. Few hours after that he vomited two times and noticed that his hearing worsened. History of ear inflammation or recent viral infection in upper airway was negative. Audiometry exam showed right sided sensorineural hearing loss, with thresholds from 15 to 70 dB. Upon examination he was given oral corticosteroid therapy. MRI showed three areas of restricted diffusion in right cerebellar hemisphere, consistent with ischemic lesions. He was then referred to neuropediatric department for additional diagnosis and treatment. On follow-up at 6 months, audiometric testing showed stationary findings without worsening of hearing threshold levels. The literature contains numerous models of the pathogenesis of SSHL, with childhood SSHL having certain peculiarities. In practical terms, the multifactorial nature of SSHL is important in the choice of diagnostic methods and treatment methods. Early recognition of central causes which could lead to severe health consequences is extremely important

Hearing loss in young boy caused by cerebellar stroke- case report

Sudden sensorineural hearing loss (SSHL) and vertigo in children are relatively uncommon. The assessment of acute vertigo in childhood is often challenging. Fortunately, a central cause is rare. The incidence of ischemic strokes in children is given as six cases in 1 000 000 children per year. The aim of this report is to present a rare case of vertigo and hearing loss in young patient developed after cerebellar ischemia. A 15-yearold boy presented in emergency ENT department with symptoms of dizziness, right sided hearing loss and tinnitus. Two days prior to the visit, he participated in a wrestling training, after which he started to feel nauseous, developed dizziness without rotatory component and mild hearing loss in right ear. Few hours after that he vomited two times and noticed that his hearing worsened. History of ear inflammation or recent viral infection in upper airway was negative. Audiometry exam showed right sided sensorineural hearing loss, with thresholds from 15 to 70 dB. Upon examination he was given oral corticosteroid therapy. MRI showed three areas of restricted diffusion in right cerebellar hemisphere, consistent with ischemic lesions. He was then referred to neuropediatric department for additional diagnosis and treatment. On follow-up at 6 months, audiometric testing showed stationary findings without worsening of hearing threshold levels. The literature contains numerous models of the pathogenesis of SSHL, with childhood SSHL having certain peculiarities. In practical terms, the multifactorial nature of SSHL is important in the choice of diagnostic methods and treatment methods. Early recognition of central causes which could lead to severe health consequences is extremely important

An Adaptive Threshold in Mammalian Neocortical Evolution

Expansion of the neocortex is a hallmark of human evolution. However, it remains an open question what adaptive mechanisms facilitated its expansion. Here we show, using gyrencephaly index (GI) and other physiological and life-history data for 102 mammalian species, that gyrencephaly is an ancestral mammalian trait. We provide evidence that the evolution of a highly folded neocortex, as observed in humans, requires the traversal of a threshold of 10^9 neurons, and that species above and below the threshold exhibit a bimodal distribution of physiological and life-history traits, establishing two phenotypic groups. We identify, using discrete mathematical models, proliferative divisions of progenitors in the basal compartment of the developing neocortex as evolutionarily necessary and sufficient for generating a fourteen-fold increase in daily prenatal neuron production and thus traversal of the neuronal threshold. We demonstrate that length of neurogenic period, rather than any novel progenitor-type, is sufficient to distinguish cortical neuron number between species within the same phenotypic group.Comment: Currently under review; 38 pages, 5 Figures, 13 Supplementary Figures, 2 Table

Granulomatozni poliangitis (Wegenerova granulomatoza) i zahvaćenost moždanih živaca

Uvod: Granulomatozni poliangitis (Wegenerova granulomatoza) je bolest koja uzrokuje nekrotizirajući vaskulitis srednjih i malih arterija i vena, te stvaranje nekrotizirajućih granuloma. Najčešće počinje kao lokalizirana granulomatozna upala sluznice gornjih ili donjih dišnih putova. Kasnije može napredovati u generalizirani oblik nekrotizirajućeg vaskulitisa. Uobičajeni simptomi bolesti su dugotrajni iscjedak iz nosa, hemoptiza, kašalj, hematoptoa, dispneja, groznica, slabost, gubitak apetita, bol, oticanje zglobova, upala oka ili uha, bol u prsima, srčani udar, ranice na koži, hipertenzija, uremija, anemija. Rjeđi simptomi granulomatoznog poliangitisa su simptomi oštećenja moždanih živaca: oslabljen njuh, izostanak njuha, gubitak vida, dvoslike, smanjeni pokreti očiju, bol lica i trnci, smanjen osjet lica, slabost žvačnih mišića, slabost mimične muskulature, šum, oslabljen sluh, asimetrično odizanje nepca, odsutnost refleksa povraćanja, nepokretiljvost glasnica, slabost sternokleidomastoidnog mišića, asimterična protruzija jezika, slabost jezika, atrofija jezika. U literaturi je opisano kako se ti simptomi javljaju u oko 5% bolesnika. Kao mogući mehanizam nastanka oštećenja smatra se širenje gramulomatozne upale iz okolnih stuktura na živce, granulomatozna upala u centralnom živčanom sustavu i vaskulitis žila koje opskrbljuju živce. Prikaz slučaja : Radi se o tridesetrogodišnjoj bolesnici koja boluje od Wegenerove granulomatoze unatrag dvije godine. Početni simptomi uključivali su iscjedak iz nosa, upale uha, tjestatste edeme nogu. U relapsu bolesti razvila je parezu povratnog živca s posljedično nepomičnom glasnicom i promuklim glasom, te parezu hipoglosusa s nemogučnošću micanja jezika u jednu stranu. Zaključak: Oštećenje funkcije moždanih živaca mogući su simptomi granulomatoznog poliangitisa. U literaturi su opisani rijetki slučajevi u kojima je oštećenje moždanog živca početni simptom bolesti, te smo ovim prikazom htjeli svratiti pozornost na mogućnost uključivanja granulomatoznog poliangitisa u diferencijalnoj dijagnostici kod bolesnika s parezom moždanih živaca nepoznatog uzroka

Non-Hodgkin\u27s lymphoma of the frontal sinus. Case report and literature review

Primary frontal sinus Non-Hodgkin\u27s lymphoma (NHL) is an extremely rare condition with 20 cases published in the existing literature to date. We describe a 64-year-old patient who presented with right orbital pain, severe headache and diplopia. He was initially diagnosed with acute exacerbation of chronic rhinosinusitis and responded well to antibiotic treatment, but his symptoms returned. The diagnosis of frontal sinus NHL was made only after functional endoscopic frontal sinus surgery was performed in general anaesthesia. A tumor mass, which was filling the entire right frontal sinus, was completely removed and sent to histopathological examination. The patient was finally diagnosed with diffuse large B-cell lymphoma of the frontal sinus and referred to the haematology department for tumor staging and chemotherapy. This case emphasizes the importance of early clinical suspicion and diagnosis, which leads to early treatment and better prognosis

Granulomatozni poliangitis (Wegenerova granulomatoza) i zahvaćenost moždanih živaca

Uvod: Granulomatozni poliangitis (Wegenerova granulomatoza) je bolest koja uzrokuje nekrotizirajući vaskulitis srednjih i malih arterija i vena, te stvaranje nekrotizirajućih granuloma. Najčešće počinje kao lokalizirana granulomatozna upala sluznice gornjih ili donjih dišnih putova. Kasnije može napredovati u generalizirani oblik nekrotizirajućeg vaskulitisa. Uobičajeni simptomi bolesti su dugotrajni iscjedak iz nosa, hemoptiza, kašalj, hematoptoa, dispneja, groznica, slabost, gubitak apetita, bol, oticanje zglobova, upala oka ili uha, bol u prsima, srčani udar, ranice na koži, hipertenzija, uremija, anemija. Rjeđi simptomi granulomatoznog poliangitisa su simptomi oštećenja moždanih živaca: oslabljen njuh, izostanak njuha, gubitak vida, dvoslike, smanjeni pokreti očiju, bol lica i trnci, smanjen osjet lica, slabost žvačnih mišića, slabost mimične muskulature, šum, oslabljen sluh, asimetrično odizanje nepca, odsutnost refleksa povraćanja, nepokretiljvost glasnica, slabost sternokleidomastoidnog mišića, asimterična protruzija jezika, slabost jezika, atrofija jezika. U literaturi je opisano kako se ti simptomi javljaju u oko 5% bolesnika. Kao mogući mehanizam nastanka oštećenja smatra se širenje gramulomatozne upale iz okolnih stuktura na živce, granulomatozna upala u centralnom živčanom sustavu i vaskulitis žila koje opskrbljuju živce. Prikaz slučaja : Radi se o tridesetrogodišnjoj bolesnici koja boluje od Wegenerove granulomatoze unatrag dvije godine. Početni simptomi uključivali su iscjedak iz nosa, upale uha, tjestatste edeme nogu. U relapsu bolesti razvila je parezu povratnog živca s posljedično nepomičnom glasnicom i promuklim glasom, te parezu hipoglosusa s nemogučnošću micanja jezika u jednu stranu. Zaključak: Oštećenje funkcije moždanih živaca mogući su simptomi granulomatoznog poliangitisa. U literaturi su opisani rijetki slučajevi u kojima je oštećenje moždanog živca početni simptom bolesti, te smo ovim prikazom htjeli svratiti pozornost na mogućnost uključivanja granulomatoznog poliangitisa u diferencijalnoj dijagnostici kod bolesnika s parezom moždanih živaca nepoznatog uzroka