NGF prevents the changes induced by monocular deprivation during the critical period in rats

Photic evoked responses were recorded from the striate cortex of Long-Evans hooded intact, monocular visual deprivation (MD) and MD treated with NGF rats. The averaged visual evoked responses (AVER) were obtained from both hemispheres and provided comparison after binocular photic stimuli between the contralateral and the ipsilateral striate cortex with relation to the MD eye. One month of monocular visual deprivation at the critical period of development resulted in marked reduction of the amplitudes of AVER components as compared to the control recordings (P < 0.001). These changes of the AVER could be prevented by NGF infusion to lateral ventricle at the dosage of 2.0–2.4 μg/day for four weeks during the monocular deprivation. In conclusion, the change of AVER amplitudes induced by monocular visual deprivation during the critical period of development can be prevented by NGF infusion to lateral ventricle.     

2000—2022年人工智能应用于食管癌领域全球研究的可视化分析

背景 随着近20余年人工智能（AI）在食管癌领域应用研究的骤增,出现了许多关于该研究的系统、荟萃分析等,但其仅针对AI在该领域应用的单一方面的总结研究,研究人员难以全面了解领域最新发展与研究热点。目的 通过文献计量分析总结AI在食管癌领域的应用,阐明AI在食管癌领域相关研究的进展、热点和新兴趋势。方法检索Web of Science Core Collection(WoSCC)的Science Citation Index Expanded(SCI-E)数据库收录的AI应用于食管癌领域的所有英文文献,检索时间2000-01-01至2022-04-06。应用Microsoft Excel 2019、CiteSpace(5.8R3-64bit)和VOSviewer(1.6.18)对文献进行发文量、国家、作者、机构、共被引和关键词分析。结果 2000—2022年共检索到AI应用于食管癌领域的文献918篇,共计引用文献总量23 490篇。发文趋势：2000—2016年为迟缓期,发文量从6篇增至40篇;2017—2022年为快速增长期,发文量从62篇突增至216篇。60个国家、118家机构、5 ...     

Senile plaques,amyloid β-protein,and acetylcholinesterase fibres: laminar distributions in Alzheimer's disease striate cortex

Summary The laminar distributions of senile plaques and amyloid -protein (AP) within the striate cortex of patients with Alzheimer's disease (AD) were studied with enhanced Bielschowsky (roughly equivalent to the Campbell technique) and immunohistochemical methods. The laminar distribution of acetylcholinesterase (AChE) fibres within the striate cortex of both AD patients and control patients was studied with an enzyme histochemical method. Quantification of Bielschowsky-stained plaque numbers along intersect lines drawn parallel to laminar boundaries revealed a significant aggregation of plaques at the interface of layers IVc and V. Lines drawn through layer VI intersected significantly fewer plaques than lines through other laminae. Immunoperoxidase staining for AP revealed a similar distribution fo senile plaques, and additional, prominent, diffuse deposits of AP within layers I and IVc. AChE fibres were markedly depleted in the striate cortex of AD cases. In control cases, AChE fibres were, like AP immunoreactivity, concentrated within layers I and IVc. The results indicate that enhanced silver methods may not reveal the complete distribution of AP. The codistribution of AP-immunoreactive diffuse amyloid deposits and AChE fibres to the same cortical laminae is consistent with the possibility that these deposits may be formed from degenerating cholinergic elements. The formation of a line of senile plaques at the interface of two cortical laminae within the striate cortex, in an anatomically analogous situation to a similar line of plaques within the dentate gyrus, suggests that formation of well-defined plaques may be accelerated by the interaction of specific neuronal systems.Supported by a Fellowship from the British Columbia Health Care Research Foundation to TGB. This work is part of the PhD. dissertation of Dr. Beach (University of British Columbia, 1991)     

Visual cortex ablation and thresholds for successively presented stimuli in rhesus monkeys: II. Hue

Summary Rhesus monkeys were trained to discriminate successively presented hues. The smallest difference they could reliably detect was determined before and after either inferotemporal ablation, or a lesion intended to remove as much as possible of prestriate area V4 (Zeki, 1973).As a group, the animals with lesions of V4 showed good but not perfect retention of their preoperative performance, and their thresholds were unaltered. The inferotemporal group showed no retention of the simplest successive task, red versus green, but after relearning their thresholds too were unaltered. It appears that animals without inferotemporal cortex can form precise internal representations of hues, and that the basis of the inferotemporal learning impairment may depend upon the nature of the stimuli to be discriminated.     

1910名初中新生慢性鼻-鼻窦炎与鼻中隔偏曲的相关性分析

目的　了解初中新生慢性鼻-鼻窦炎发病与鼻中隔偏曲的相关性。 方法　分层随机抽取郑州市1910名12~15岁初中新生，采取问卷调查及专科体检的形式，根据量表、体检结果，了解鼻中隔偏曲和慢性鼻-鼻窦炎患病情况，分析两者相关性。 结果　抽样初中新生慢性鼻-鼻窦炎的患病率为6.2%（119/1910）；慢性鼻-鼻窦炎患病群体与非患病群体中，轻、中度鼻中隔偏曲的发生率分别为27.7%（33/119）和31.2%（559/1791），两者差异无统计学意义（χ2=0.632，P>0.05）；重度鼻中隔偏曲的发生率分别为13.4%（16/119）和8.0%（144/1791），两者差异有统计学意义（χ2=4.248，P<0.05）。 结论　初中新生慢性鼻-鼻窦炎发病与重度鼻中隔偏曲具有相关性。     

Retinal projections to the lateral posterior-pulvinar complex in intact and early visual cortex lesioned cats

In intact cats, it is generally considered that the lateral posterior-pulvinar complex (LP-pulvinar) does not receive direct retinal terminals, with the exception of the retino-recipient zone known as the geniculate wing. There is, however, some evidence that early lesions of the visual cortex can occasionally induce the formation of novel retinal projections to the LP nucleus. Given the importance of knowing the connectivity pattern of the LP-pulvinar complex in intact and lesioned animals, we used the B fragment of cholera toxin, a sensitive anterograde tracer, to reinvestigate the retinal projections to the LP-pulvinar in normal cats and in cats with early unilateral lesions of the visual cortex (areas 17 and 18). Immunohistochemical localization of the toxin was performed to show the distribution and morphology of retinofugal terminals. A direct bilateral but predominantly contralateral retinal projection reached the caudal portion of LPl and LPm in the form of patches located mainly along its dorsomedial surface and many scattered terminals. The distribution of retinal projections to LP-pulvinar in intact and operated cats did not differ. Contrary to what had been previously reported, we found no evidence for lesion-induced sprouting of retinal axons in these higher-order thalamic nuclei. Retinal input to the LP-pulvinar might modulate visual responses driven by primary visual cortex or superior colliculus.     

Subchondroplasty in the treatment of bone Marrow lesion in early Knee Osteoarthritis: A systematic review of clinical and radiological outcomes

BackgroundKnee osteoarthritis (KOA) is increasingly prevalent in North American society. The significant societal burden it represents makes it essential to promote and target new treatments in earlier phases of the disease. Among others, subchondroplasty is a newly documented technique using calcium phosphate injection targeting the osteochondral lesions preceding KOA, also known as Bone Marrow Lesions (BMLs). This article aimed to review the existing literature on clinical and radiological outcomes of subchondroplasty in the treatment of BMLs in KOA.MethodA systematic review was performed using PubMed, Embase, Medline and Cochrane Database of Systematic Reviews. Studies on calcium phosphate injections into BMLs for KOA and its clinical and radiological outcomes were screened and reviewed by independent evaluators.ResultsAfter screening, ten articles were included, totaling 540 patients. Follow-up ranged from 6 months to 7 years. Overall, the procedure showed significant functional and quality of life improvement, as well as pain relief, as shown by Patients-Reported Outcomes Measures (PROMs). There were very few complications reported, the most important being leakage of calcium phosphate outside the targeted site. Conversion rate to total knee arthroplasty (TKA) ranged from 14 % to 30 % at 2 years post-procedure. Long term radiological outcomes have been poorly documented.ConclusionsSubchondroplasty is a promising avenue for the treatment of KOA. However, quality evidence is still required before any real conclusions and practical management guidelines can be drawn. Prospective, randomized studies with a control group and a rigorous assessment of long-term clinical and radiological outcomes are recommended.     

Recovery of function in cat visual cortex following prolonged deprivation

Summary Evidence that there is a critical period during which response characteristics of neurons in visual cortex of the cat may be influenced has been provided in several studies, which suggest that the period of influence is restricted to the first few months of life. Using a somewhat different experimental procedure, we have obtained evidence that cortical units retain plasticity long after the end of this period has passed. In our procedure prolonged visual deprivation was followed by exposure in a normal visual environment. The animals were maintained throughout the first year of life either in total darkness or in an enclosure illuminated intermittently by a strobe light. Following the period of deprivation, electrophysiologic recordings were taken from some of these animals. The remaining cats were permitted 6–12 months in a normally-illuminated environment prior to recording. Cats of the same age reared from birth in a normally lit environment were also recorded.Cortical neurons in cats deprived of any normal visual experience rarely show orientation selective responses. In animals allowed subsequent normal visual experience about one-half of the units studied exhibited this property. This level of response specificity is intermediate between that of normally-reared and recently-deprived animals. While most cortical units in normally-reared cats exhibit direction selectivity, this property is rarely observed in the recovery cats. A number of unit types which are rarely observed in either normal or totally deprived animals were encountered in cats that had normal exposure following prolonged deprivation. A convergent strabismus was observed, in contrast with the divergent strabismus often shown by cats immediately following prolonged visual deprivation. This shows that ocular alignment as well as cortical unit properties can remain plastic in the adult.Supported by NRC Grant No. A9939 and M.R.C. Grant No. MA5201 (to M.C.) and Grants from NIH and the Sloan Foundation (to A.H.).     

Habituation and adaptation of the vestibuloocular reflex: a model of differential control by the vestibulocerebellum

Summary We habituated the dominant time constant of the horizontal vestibuloocular reflex (VOR) of rhesus and cynomolgus monkeys by repeated testing with steps of velocity about a vertical axis and adapted the gain of the VOR by altering visual input with magnifying and reducing lenses. After baseline values were established, the nodulus and ventral uvula of the vestibulocerebellum were ablated in two monkeys, and the effects of nodulouvulectomy and flocculectomy on VOR gain adaptation and habituation were compared. The VOR time constant decreased with repeated testing, rapidly at first and more slowly thereafter. The gain of the VOR was unaffected. Massed trials were more effective than distributed trials in producing habituation. Regardless of the schedule of testing, the VOR time constant never fell below the time constant of the semicircular canals (5 s). This finding indicates that only the slow component of the vestibular response, the component produced by velocity storage, was habituated. In agreement with this, the time constant of optokinetic after-nystagmus (OKAN) was habituated concurrently with the VOR. Average values for VOR habituation were obtained on a per session basis for six animals. The VOR gain was adapted by natural head movements in partially habituated monkeys while they wore ×2.2 magnifying or ×0.5 reducing lenses. Adaptation occurred rapidly and reached about ±30%, similar to values obtained using forced rotation. VOR gain adaptation did not cause additional habituation of the time constant. When the VOR gain was reduced in animals with a long VOR time constant, there were overshoots in eye velocity that peaked at about 6–8 s after the onset or end of constant-velocity rotation. These overshoots occurred at times when the velocity storage integrator would have been maximally activated by semicircular canal input. Since the activity generated in the canals is not altered by visual adaptation, this finding indicates that the gain element that controls rapid changes in eye velocity in the VOR is separate from that which couples afferent input to velocity storage. Nodulouvulectomy caused a prompt and permanent loss of habituation, returning VOR time constants to initial values. VOR gain adaptation, which is lost after flocculectomy, was unaffected by nodulouvulectomy. Flocculectomy did not alter habituation of the VOR or of OKAN. Using a simplified model of the VOR, the decrease in the duration of vestibular nystagmus due to habituation was related to a decrement in the dominant time constant of the velocity storage integrator (1/h ₀). Nodulouvulectomy, which reversed habituation, would be effected by decreasing h ₀, thereby increasing the VOR time constant. Small values of h ₀ would cause velocity storage to approach an ideal integrative process, leading the system to become unstable. By controlling the VOR time constant through habituation, the nodulus and uvula can stabilize the slow component of the VOR. VOR gain adaptation was related to a modification of the direct vestibular path gain g ₁, without altering the coupling to velocity storage g ₀ or its time constant (1/h ₀). The mismatched direct- and indirect-pathway gains simulated the overshoots in the dynamic response to a step in velocity, that were observed experimentally. We conclude that independent distributed elements in the VOR modify its dynamic response, under control of separate parts of the vestibulocerebellum.     

Physical work capacity and effect of endurance training in visually handicapped boys and young male adults

Summary The purpose of the present study was to evaluate the relationship between several physical fitness parameters and eyesight divided into 3 grades in visually handicapped boys and young male adults, and to investigate the effect of mild exercise training on physical and psychic symptoms as well as cardiorespiratory fitness. Four subjects were totally blind (TB), 6 were semi-blind (SB) and 27 had amblyopia (AM). Physical fitness tests consisted of maximal oxygen uptake (V _{O 2max}), maximal pedalling speed and power, maximal stepping rate, and isometric knee extention strength. Compared with AM and SB groups, the TB group was inferior in all physical fitness parameters. Especially,V _{O 2max} in TB (26 ml · kg^–1 · min^–1) was about 56% of that in agematched Japanese sighted subjects and was significantly low compared with the AM and SB groups. Both muscle strength and maximal pedalling power corresponded to about 50% that of the age-matched sighted group. Six SB and 4 TB students (¯x=17.7 years) were trained for 6 weeks on a bicycle ergometer at an intensity of 50%V _{O 2max}. Training was undertaken for 3 days per week and maintained for 60 min per session. After training, physical and psychic symptoms determined by the Cornell Medical Index improved significantly. These results indicate that low physical work capacity in visually handicapped boys and young male adults is due to the lack of physical activity, and that mild endurance training is effective in improving physical and psychic symptoms as well as cardiorespiratory fitness.