To provide a comprehensive review of the incidence, risk factors, and management of early complications after deep anterior lamellar keratoplasty (DALK), Descemet stripping automated keratoplasty (DSAEK), and Descemet membrane endothelial keratoplasty (DMEK).A literature review of complications, that can occur from the time of the transplant up to 1 month after the transplant procedure, was conducted. Case reports and case series were included in the review.Complications in the earliest postoperative days following anterior and posterior lamellar keratoplasty have shown to affect graft survival. These complications include, but are not limited to, double anterior chamber, sclerokeratitis endothelial graft detachment, acute glaucoma, fluid misdirection syndrome, donor-transmitted and recurrent infection, and Uretts-Zavalia syndrome.It is essential for surgeons and clinicians to not only be aware of these complications but also know how to manage them to minimize their impact on long-term transplant survival and visual outcomes. Over the last two decades, significant advances have been made in corneal transplantation techniques. Surgical management of corneal disorders has evolved from the replacement of full thickness cornea to replacing only the diseased corneal stroma or endothelium , 2. ThisComparing the possible complications after PK with those after lamellar keratoplasty, some of the complications related to sutures, such as ametropia, and late wound dehiscence, are obviated only in EK and not in ALK. However, lamellar keratoplasties are not free from complications which could affect graft survival. These complications occur in the earliest weeks post-transplant and in most cases are evident at the first postoperative clinic examination. The diagnosis and successful management of these early complications is crucial for long-term lamellar graft survival . In thisOR DALK OR EK OR DMEK OR DSAEK.” Articles, including case reports and case series, up to June 2022 were included. Postoperative complications which can manifest up to 4 weeks post-transplant were included.A single investigator (DR) used the MEDLINE database (via PubMed) to search for and identify articles for inclusion in this review. Keywords used were “Complication” AND “ALK Complications were divided into anterior lamellar keratoplasty complications , endothelial keratoplasty complications , and anterior lamellar keratoplasty and endothelial keratoplasty complications . Table Double anterior chamber describes the separation of host Descemet membrane (DM) from the donor stroma. It occurs in about 10% of cases after ALK, with no difference accordingly to surgeon grade, and it has been found that 0.4% are converted to PK , 8, 9.It most frequently occurs following central , rather than midperipheral (within 4–6 mm from the center), Descemet membrane perforation. It is either apparent during surgery or not, with subsequent continuous flow of aqueous between both sides of the Descemet Membrane, and after a type 2 bubble .Intraoperative complications are not the only causes of double chamber, as it may occur in cases of mismatch between donor-recipient curvature and presence of host risk factors, such as pseudophakia, and stromal corneal scarring in either eyes with or without keratoconus , 11.When considering if there are differences in double chamber formation risk following manual, pneumatic, or viscoelastic dissection, comparative studies are lacking, whereas there is evidence to suggest that femtosecond-assisted deep anterior lamellar keratoplasty (DALK) is associated with a lower risk of intraoperative Descemet membrane perforation and double chamber formation, compared to manual dissection .If micro perforation occurs during surgery, it is not advisable to perform a Descemet-On DALK, which consists of transplanting a full thickness donor graft with intact DM and endothelium, because the double chamber may persist if the endothelium has not been removed from the donor , 14.Postoperative management depends on the area of detachment. Small, peripheral areas of detachment that do not extend can be observed without intervention as most naturally resolve in a few days or cause no visual symptoms in the long term. However, in most cases, the area of detachment is large, central, or symptomatic and in these cases air or gas tamponade is recommended, with a high chance of reattachment after just one rebubbling . In case6), or perfluoropropane (C3F8) should be combined with either pupil dilation or peripheral iridotomy (PI) and intravenous mannitol 20% to prevent pupil block glaucoma [The aim of injecting air or gas tamponade is to drain the fluid at graft-host junction possibly sealing the micro perforation. Intracameral injection of air, sulfur hexafluoride  reformation, it has been demonstrated that the average loss of endothelial cells is greater than 20% , while iBesides PK or EK , other rAdditionally, the use of an amniotic membrane (AM) patch has been reported to seal the DM rupture . This prAnother option may be injecting an air bubble in the anterior chamber and then draining it out using a spatula as an iris repositor thorough a partial thickness corneal tunnel , 24.Apart from the cases previously mentioned above, three cases of spontaneous resolution of double anterior chamber in 6–8 weeks previously unresponsive to multiple attempts of rebubbling have been reported. Interestingly, they were managed by the “wait and see” , 26 apprAlong with traumatic DM tear, a case of spontaneous DM tear has been reported in the literature, with no subsequent DMD, 4 weeks following an uncomplicated big-bubble DALK . PossiblClinically, the patient presented with circumscribed eccentric stromal oedema, and the management was conservative, with only topical use of steroid eye drops, with a partial resolution of oedema after 3 months. DMD did not occur in the follow-up time .Post-keratoplasty atopic sclerokeratitis is a strong inflammatory reaction that simulates a graft rejection . It is aSigns are severe diffuse inflammation of the sclera, loosening of the sutures Fig. , and perRisk factors are active and not well-controlled atopic diseases , blepharitis, and corneal neovascularization –32.The management requires a rapid surgical approach, made by removal of the loose sutures and re-suturing with interrupted sutures if previously running sutures were used, as sclerokeratits tends to be unresponsive to topical corticosteroid therapy alone –32. AfteThe efficacy of adding the cyclosporine to the systemic therapy is based on its ability to better inhibit interleukin-5 (IL-5), compared to corticosteroids . Higher However, prophylactic use of systemic cyclosporine in patients at risk is not recommended in view of possible systemic adverse events  , 34.Based on the presence or not of contact area between the donor tissue and the recipient bed, the detachment can be defined as partial (or incomplete) or total (complete) where the graft floats free in the anterior chamber .The incidence of graft detachment differs according to the type of EK. It has been found to be higher in cases of DMEK compared to DSAEK , 35.Reported rates of graft dislocation post-DSAEK vary widely from 0 to 42%, whereas in cases of DMEK, partial graft detachment has a reported incidence of 4–95% and a rebubbling rate of 2.4–82% (mean incidence 28.8%), while total graft detachment has an incidence of about 0.73–7% .Risk factors associated with higher risk of postoperative graft detachment in cases of endothelial keratoplasty are graft preparation, learning curve, bullous keratopathy, graft size, age (younger recipient and older donor), previous PK and EK, presence of glaucoma surgery (both glaucoma drainage device and filtrating surgery), hypotony, abnormal anterior segment anatomy , and incomplete descemethorexis –49.The use of pre-loaded grafts, both in DSAEK and DMEK, is now an option , 51. NonConsidering the lens status of the host, aphakia and anterior chamber intraocular lens are risk factors for graft detachment in cases of DMEK , 57, but6 20% is associated with lower rate of graft detachment compared with 100% air [Focusing instead on whether or not the type of AC tamponade may influence the graft detachment, in DMEK, SF100% air , 59.Detachment post-DSAEK is diagnosed by slit lamp examination, usually clearly indicated by separation of the graft from the posterior recipient stroma Fig.  but in sIdentification and quantification of graft detachment is critically important post-DSAEK and DMEK as a decision must be made on the necessity for repeat bubble injection for graft repositioning and attachment , 70.In cases of DSAEK graft detachment, rebubbling should not be delayed, because even in cases of partial detachment, the risks are high that the area of the detachment will extend to the full graft. Only in cases of far-peripheral detachment rebubbling may not be an immediate choice, and a wait-and-see approach can be adopted.6 and C3F8) [In rebubbling, air or gas is injected into the anterior chamber posterior to the graft through a peripheral needle entry site and the graft positioned as during the initial surgical procedure. Use of a narrow gauge (27G or 30G) needle and relatively long intrastromal needle track reduces the problem of air reflux. This can be done at the slit lamp or on the operating table. Drainage of the pre-descemetic fluid via an external stab incision or internal aspiration with a needle may accompany the procedure for better reattachment. A longer period posturing supine usually allows secure attachment of the graft. Repositioning the DSAEK grafts by filling the anterior chamber with air is effective in managing dislocations, and some authors advocate the use of high-density gases for the repositioning of the graft  –73. To dThe management of graft detachment post-DMEK differs from DSAEK. The most common graft detachment following DMEK is a partial one, with a reported incidence of 4–95% and a rebubbling rate of 2.4–82% (mean incidence 28.8%), while total graft detachment has an incidence of about 0.73–7% , 74–78.Various classifications of DMEK graft detachment based on OCT appearances have been proposed –81. The Fortunately, most post-DMEK detachments are non-progressive, and intervention is not required. The impact on the postoperative management of a given detachment depends on its size and location. However, numerous case reports on spontaneous resolution of corneal oedema, either by spontaneous reattachment of graft Descemet membrane –88 or miInstead, detachments > 1/3rd of the graft surface area, scrolled in configuration, located in the center or involving the visual axis should be managed by repeat air/gas injection to reattach the graft. The rebubbling procedure should not be delayed, in order to hasten visual rehabilitation and to prevent the wrinkling, fibrosis, and shrinkage of graft Descemet membrane, which results in poor visual outcome .3F8 except in cases of superior DMD, reporting successful management [There are various techniques for management of graft detachment. Sharma et al. use intracameral injection of 14% Cnagement .6 as a tamponade is associated with 58% less rebubbling procedures compared with air [3F8 is a better option as a tamponade in cases of previous failure observed with air- or SF6-assisted rebubbling attempts [As mentioned before, the use of 20% SFwith air . Howeverattempts .Regarding the toxicity of tamponade agents, animal studies indicate a similar endothelial toxicity profile for all three gases . The oveAlternatively, if rebubbling is not performed, corneal clearance usually occurs but over a longer time period  and only 50% of these eyes reach a visual acuity of 20/40 –63, 89. Effect of rebubbling on graft endothelial cell density (ECD) has been evaluated. In cases of single rebubbling versus no rebubbling, no differences in ECD are reported, while in cases of more than one rebubbling, a higher rate of endothelial cell loss is reported –101.Re-transplantation is feasible, but may be considered as a last resort, since it is expensive, laborious, and risks further complications.Injection technique varies between surgeons; it is usually performed at the slit lamp using a 27–30G needle or Fogla air injection cannula, mounted on a 3-ml syringe, through a new paracentesis to create an air-tight seal afterwards. The paracentesis can be made by a 20–23G side port blade and acts also as a valve allowing better control over intraocular pressure and percentage anterior chamber air fill. Attention should be paid in cases of DMEK rebubbling on a previous PK, as it has been reported in literature that it may causes wound dehiscence at the graft-host junction .The site of paracentesis can be in the inferior temporal quadrant or in a site where Descemet membrane is still attached , 103. OCInstead, a complete detachment post-DMEK Fig.  is more This technique requires staining of the graft in the anterior chamber with trypan blue, making a 20-gauge paracentesis and immediately injecting air to avoid the staining of the host stroma. Subsequently, the stained DMEK graft is tapped to open it, and then attached to the host stroma injecting an air bubble.The combined yield from AS-OCT at 1 h and 1 week post-operation has proven informative to predict if a detachment is likely to be transient or lasting . At 1 weIn cases of intraoperative attachment of grafts in an inverted position , there are two pathognomonic signs: (1) an extremity of the graft free-floating with posteriorly curled edges, visualized using AS-OCT Fig. ; and (2)DSAEK and DMEK share the risk of postoperative acute glaucoma due to pupil block caused by the air or gas bubble in the anterior chamber Fig.  or angleHowever, in a series of 40 eyes (24 DMEK and 16 DMEK rebubbled) treated with DMEK, all of them had increased IOP after surgery, despite the presence of inferior (PI) in all. Of these, 3 eyes (DMEK without rebubbling) had intraocular pressure (IOP) > 30 mmHg at 2 h after surgery with no pupillary block. None of the rebubbled eyes had IOP > 30 mmHg at 2 h. Overall, the IOP started to lower 3 h after surgery and IOP was normal in all patients at 1 week .This opens up an interesting question of whether or not the early postoperative IOP ≥ 30 mmHg may affect the DMEK outcome pertaining to postoperative best-corrected visual acuity, central corneal thickness, and graft endothelial cell density. Temporary IOP elevation post-op did not seem to affect functional and morphological outcomes as reported by another retrospective analysis of 20 eyes from 172 patients with raised IOP in the first three postoperative days .However, the acute pressure elevation can lead to vision loss due to glaucomatous optic neuropathy. The incidence of pupillary block glaucoma is between 0.1 and 9.5% , 110. UsIn some cases of acute glaucoma, the attack can be reversed by pupil dilation, topical apraclonidine, systemic acetazolamide and supine positioning for 1–2 h, or evacuation of some air and replacement with saline . If the A possible (rare) consequence of acute glaucoma due to pupillary block following endothelial keratoplasty is the Urrets-Zavalia syndrome that will be discussed in a dedicated paragraph.Although rare, another condition should be ruled out in cases of high IOP after surgery and fluid misdirection syndrome (FMS). To date, cases of FMS following endothelial transplant, both DSAEK and DMEK, are still limited to a case series of 11 eyes, but it is a condition which surgeons and clinicians should be aware of .The main risk factor for FMS is small hyperopic eyes  with a shallow anterior chamber (mean anterior chamber depth in the case series 2.4 mm). Previous cataract surgery does not prevent FMS after endothelial keratoplasty .Clinical findings of FMS are shallowing of anterior chamber despite the presence of PI, IOP > 21 mmHg, and lack of presence of any possible cause of angle closure. The management of acute FMS, with onset immediately after surgery, requires a pars plana decompression. Instead in cases of chronic FMS, which can occur days or months after surgery, and is characterized by a progressive shallowing of the anterior chamber, a step-by-step approach is recommended, starting with topical hypentise eyedrops and ciclopegic agents, and then, YAG laser iridotomy with anterior hyaloidotomy and posterior capsulotomy. In case of no resolution, total pars plana vitrectomy combined with zonulectomy, iridectomy, and capsulectomy is recommended .Microbial keratitis is a serious complication of any type of keratoplasty and is usually associated with a poor visual prognosis because of the difficulty of successful treatment without residual scarring.The reported incidence of infectious keratitis following ALK is 1% , 113; hoHowever, at present, there are limited studies documenting infectious keratitis after endothelial or anterior lamellar keratoplasty to adequately assess the outcomes , 116.Following anterior or posterior lamellar keratoplasty, the features are white or creamy deposits at the interface between the host-donor Fig. .Fig. 8CaCandida is the most common reported pathogen and fungal etiology is suggested by an interval of 1–3 weeks post-transplant –128. MorIn cases of de novo infection, the eye bank in which the donor cornea is processed must be informed and any available microbiology information on contamination of the donor scleral rim or culture media must be obtained. Indeed, according to the literature, up to 2.1% of corneal donor tissue is positive for fungal rim cultures, which may cause, if transplanted, a clinical infection in the host in about 5.6–13.5% cases –132.Subsequently, pathogens isolated from eye bank samples are likely to correlate with in vivo infection in the recipient eye and provide a rational basis for therapeutic decisions until definitive information is available on isolates from the transplanted eye. All the available diagnostic methods  must be used to confirm infection, isolate the pathogen, and inform the choice of anti-microbial agents.Considering instead the risk of transmission of COVID-19 virus transmission from donor corneal tissues, a review from Saltz et al. reported no evidence of viable virus and no cases of transmission of SARS‑CoV‑2 .Reports on the efficacy of antimicrobial treatment in infectious keratitis after keratoplasty range from 43 to 74% . Fungal When the indication for lamellar graft is microbial keratitis in which a medical cure has not been achieved, the surgeon needs to be aware of the high risk of recurrence of infection after surgery. The identification of the pathogen (confirmed before surgery or using the excised tissue) will influence the postoperative treatment. If a microbiological diagnosis has not been obtained prior to surgery, it is mandatory to examine the excised corneal tissue by culture and other available methods. Until a confirmed microbiology diagnosis is available, antimicrobial therapy should be guided by pre-transplant clinical features and local epidemiology.Uretts-Zavalia syndrome (UZS), also known as Castroviejo syndrome, is described as the appearance of a fixed and dilated pupil following intraocular surgery .Initially reported following PK , it has Clinically, patients report pain in the hours following surgery. The usual finding at the first postoperative examination is a fixed dilated pupil, not reactive to light or accommodation and iris atrophy. Between 30 and 60% of patients with this complication will recover some form of pupil reactivity within 1 to 18 weeks, with some patients regaining normal pupil size. The prognosis depends on the severity of the iris ischemia/atrophy, and patients with marked atrophy of both the anterior and posterior layers of the iris will have long-term photophobia due to irreversible mydriasis and chronic low-grade iritis. Reports on treatment in the literature are anecdotal. In cases where there is iris-host cornea touch, separation using a cyclodialysis spatula has been suggested. In cases of elevated IOP due to blood or viscoelastic in the anterior chamber, a washout is recommended, which can be done using several techniques. The easiest is to perform two clear corneal incisions at 180° apart. Through one incision, BSS is irrigated, while the opposite incision is depressed to evacuate the blood. In cases of unsuccessful irrigation using BSS, or presence of large blood clots, irrigation and aspiration or anterior vitrectomy may be required . An ante


Cytokine storms are considered a driving factor in coronavirus disease 2019 (COVID-19) severity. However, the triggering and resolution of this cytokine production, as well as the link between this phenomenon and infected cells, are still poorly understood. In this study, a cross-species scRNA-seq analysis showed that cytokine-producing macrophages together with pneumocytes were found to be the main contributors of viral transcripts in both Syrian hamsters and African green monkeys. Whatever the cell type, viral read-bearing cells show an apoptotic phenotype. A comparison of SARS-CoV-2 entry receptor candidates showed that Fc receptors are better correlated with infected cells than ACE2, NRP1, or AXL. Although both species show similar interferon responses, differences in adaptive immunity were highlighted. Lastly, Fc receptor and cytokine upregulation in M1 macrophages was found to correlate with a comprehensive interferon response. Based on these results, we propose a model in which lung macrophages play a central role in COVID-19 severity through antibody-dependent enhancement. This novel emerging betacoronavirus has a high human-to-human transmission capacity and is able to infect other mammals such as rodents, carnivores, and nonhuman primates . Despitein vitro  and the angiotensin-converting enzyme 2 (ACE2), the N-terminal domain (NTD) and the S1/S2 polybasic site emerge as key determinants in host-virus interaction. Indeed, analysis of dominant epitopes targeted by neutralizing antibodies allowed the identification of a so-called super site at the tip of the NTD , 6. Thisin vitro , its Cenin vitro , 15, ACEin vitro .Although, in the lungs, SARS-CoV-2 was thought to mainly infect type 2 pneumocytes through ACE2/RBM interactions, evidence of infection of bronchial ciliated cells , alveolain vitro. In a selected convalescent individual with highly neutralizing serum IgGs, Zhou et al.  and anti-spike antibodies . This lau et al.  demonstrIn lung alveoli, resident alveolar macrophages (rAM) are considered the primary line of defense, known to self-renew and able to recruit monocyte-derived macrophages in response to depletion . Althougin vivo molecular interactions between pathogens and their hosts. Although this technique has been successfully applied to COVID-19 patients (Mesocricetus auratus) is a well-recognized model mimicking lung lesions similar to hospitalized humans, mounting a neutralizing antibody response against SARS-CoV-2, and replicating age-dependent symptomatology (Chlorocebus aethiops) are a commonly used model for studies of respiratory viruses, including coronaviruses (Single-cell RNA sequencing (scRNA-seq) emerges as a powerful tool to shed light on the complexity of patients –41, the patients . The Syrmatology –47. At aaviruses –50.In this work, previously published scRNA-seq , 43 were22.1Dimensionality reduction of cross-species integrated AGM and hamster scRNA-seq, followed by apoptotic cell characterization using univariate UMAP, allowed identification of the main expected lung cell types  or (−)gRNA, were first highlighted on the cross-species UMAP plots (To better assess the contribution of each cell type to (+) and (−)gRNA reads, percentages of positive cells as well as mean and total numbers of viral read counts of each genomic strand in each cell type and in each experimental modality were plotted and statistically assessed (Considering (+)gRNA (When it comes to (−)gRNA-positive cells gRNA, only (+)gRNA, or no viral reads was compared for each cell type. To this end, the mean expression of genes and the total number of expressed genes were assessed (p < 0.0001). While (−)gRNA and (+)gRNA-bearing cells were not significantly different from each other. However, when it comes to mean expression levels, (−)gRNA-positive cells showed a significantly lower number of expressed genes than (+) gRNA-positive cells (p = 0.0001). Globally, four-way linear models considering as explanatory variables: species, time points, cell types, and scRNA-seq runs, showed that viral read-bearing cells had systematically lower transcriptomic expression both in terms of mean expression levels and number of expressed genes than their viral read-negative counterparts  gRNA-positive cells was compared. Considering the possibility of antibody-dependent infection, the Fc receptor FcγR4, which was found to be significantly associated with M1 macrophages and upregulated from 2 dpi in hamsters, was also added to the analysis together with its AGM ortholog FcγR3a , and type II interferon, that is, interferon-gamma (IFN-γ), were already and clearly activated at this first disease time point. Among the upregulated interferon-stimulated genes (ISGs): GTPases , guanylate-binding proteins , 2′-5′ oligoadenylate synthetases , interferon-induced proteins with tetratricopeptide repeats , interferon-induced proteins , interferon-stimulated gene 15 (ISG15), interferon regulatory factors , interferon-induced transmembrane protein 3 (IFITM3), SP100, RSAD2, poly(ADP-ribose) polymerase family members , tripartite motif (TRIM) family proteins , Bst2, and intracellular RNA-sensors (Rig1/DDX58 and PKR/EIF2AK2) were found upregulated at 2 dpi.In AGM, where mock samples were not present in the experiment, comparison between live and irradiated virus inoculum at 3 dpi using pseudobulk RNA-seq allowed to highlight types I and II interferon responses similar to the ones observed at 2 dpi in Syrian hamsters , types I and II interferon responses further increase significantly  monocyte and macrophages chemoattractants: Ccl2, Ccl3, Ccl4, Ccl5, Ccl7, Ccl8, Ccl12, and Cxcl2-like , together with three nonclassical MHCI (ncMHCI) related alpha chains: D-37, Saoe, and Q10, were significantly overexpressed at 2 dpi in hamsters. Interestingly, the expression of the putative cognate receptor Nkg2d was found to follow the same pattern of expression as IFN-γ in hamster NK cells. Likewise, the activating receptor Nkp46/Ncr1 peaked in NK at 5 dpi. Furthermore, the expression of T-box transcription factor 21 (Tbx21/T-bet), known as a master regulator of type 1 immunity commonly mounted against viral infection, was also found to be overexpressed in NK cells and peaking at 5 dpi  and new transcript variants of MHCI already overexpressed at 2 dpi, six MHCII transcripts: E-S beta chain-like, E-U alpha chain, A-U alpha chain, M beta 1, M alpha chain, A beta chain, and gamma chain/Cd74, were also found to be significantly upregulated. The cell type distribution of these genes shows that these MHCI transcripts were mainly overexpressed in AT2 and macrophages , which is responsible for somatic hypermutation (SHM) and class switch recombination (CSR), and POU domain class 2-associating factor 1 (Pou2af1), the transcription factor regulating immunoglobulin expression , 53.p < 0.0001) and between 3 and 5 dpi (p < 0.0001). Furthermore, in hamster Aicda-positive cells, the secreted form of IgM was found to be significantly overexpressed compared to its Aicda− counterparts in the same myeloid cell types (p < 0.0001)  FcγR better correlated with infected cells than the known SARS-CoV-2 entry receptors ACE2, NRP1, and AXL in both species; (2) viral read-bearing cells show dying cells/apoptotic phenotype, whatever the cell type; (3) B-cell activation was detected from the earliest time points of infection; (4) antibody isotypes overexpressed during and after infection are known to bind FcγR, the latter being upregulated in viral read-bearing macrophages; (5) type 2 interferon response was observed in both species together with the induction of FcγR; and (6) the recent experimental demonstration that SARS-CoV-2 infects macrophages, we propose a model in which COVID-19 severity increases through a positive feedback loop involving (1) interferon polarized, pro-inflammatory cytokine-producing M1 macrophages cross-presenting viral peptides on MHCI upon antibody-dependent infection and (2) chemoattracted and proliferating NK and T cells producing IFN-γ upon MHCI ligation.In this model, depicted in Although this study provides a consistent and comprehensive explanation of how severe COVID might develop in humans, it does not replicate all cases observed in COVID patients in whom additional diseases, genetic disorders, and secondary infections may occur. We believe, though, that the rodent/primate scRNA-seq integration provided in this manuscript opens important perspectives regarding human health and veterinary medicine as it provides evidence that single-cell transcriptomes from distant species can be aggregated to form relevant cell type clusters and used to compare results collected from different hosts.4via a combination of intranasal (0.5 ml per nostril), intratracheal (4 ml), oral (1 ml), and ocular (0.25 ml per eye) administration of a 4 × 105 TCID50/ml (3 × 108 genome copies/ml) virus dilution in sterile modified Eagle’s medium (MEM). As a control, two animals  were inoculated via the same routes with the same dose and volume of inoculum but with noninfectious γ-irradiated SARS-CoV-2. Syrian hamster modalities consisted of three samples of each of the following modalities: mock and 2, 3, 5, and 14 days post-infection with live viruses. Hamsters at 10–12 weeks of age were intranasally infected with 1 × 105 pfu SARS-CoV-2 by applying 60 μl MEM with 1 × 105 pfu SARS-CoV-2 or plain cell culture medium for mock-infected animals. All animal experiments were approved by the respective animal care committees. Raw data were processed with Salmon-Alevin 1.4.0 . Apoptotic cells were thus reassigned according to univariate UMAP cell typing (see above).The following cell types were found: resident alveolar macrophages (Marco+), monocytes (Ccr2+), nonclassical/patrolling monocytes (Cx3cr1+) , myeloidDifferentially expressed genes in hamsters were identified using the following RNA-seq datasets: SRR13151598, SRR13151599, SRR13151600, SRR13151604, SRR13151605, SRR13151606, SRR13151610, SRR13151611, SRR13151612, SRR13151616, SRR13151617, SRR13151618, SRR13151621, SRR13151622, and SRR13151623. For AGM and for some analyses referred to in the text for hamsters, the scRNA-seq mentioned previously was used as pseudobulk RNA-seq. After reading pseudoalignment on respective reference transcriptomes using Salmon, differentially expressed genes and gene ontology enrichments were performed in R using the Edger  and clushttps://www.ncbi.nlm.nih.gov/nuccore/OQ624913; https://www.ncbi.nlm.nih.gov/nuccore/OQ624914; https://www.ncbi.nlm.nih.gov/nuccore/OQ624915; https://www.ncbi.nlm.nih.gov/nuccore/OQ624916; https://www.ncbi.nlm.nih.gov/nuccore/OQ624917; https://www.ncbi.nlm.nih.gov/nuccore/OQ624918; https://www.ncbi.nlm.nih.gov/nuccore/OQ624919; https://www.ncbi.nlm.nih.gov/nuccore/OQ624920; https://www.ncbi.nlm.nih.gov/nuccore/OQ624921; https://www.ncbi.nlm.nih.gov/nuccore/OQ624922; https://www.ncbi.nlm.nih.gov/nuccore/OQ62492; https://www.ncbi.nlm.nih.gov/nuccore/OQ624924; https://www.ncbi.nlm.nih.gov/nuccore/OQ624925; https://www.ncbi.nlm.nih.gov/nuccore/OQ624926; https://www.ncbi.nlm.nih.gov/nuccore/OQ624927; https://www.ncbi.nlm.nih.gov/nuccore/OQ624928; https://www.ncbi.nlm.nih.gov/nuccore/OQ624929; https://www.ncbi.nlm.nih.gov/nuccore/OQ624930; https://www.ncbi.nlm.nih.gov/nuccore/OQ624931; https://www.ncbi.nlm.nih.gov/nuccore/OQ624932; https://www.ncbi.nlm.nih.gov/nuccore/OQ624937; https://www.ncbi.nlm.nih.gov/nuccore/OQ624938; https://www.ncbi.nlm.nih.gov/nuccore/OQ624939; https://www.ncbi.nlm.nih.gov/nuccore/OQ624940; https://www.ncbi.nlm.nih.gov/nuccore/OQ624941; https://www.ncbi.nlm.nih.gov/nuccore/OQ624942; https://www.ncbi.nlm.nih.gov/nuccore/OQ624943; https://www.ncbi.nlm.nih.gov/nuccore/OQ624944; https://www.ncbi.nlm.nih.gov/nuccore/OQ624945; https://www.ncbi.nlm.nih.gov/nuccore/OQ624946; https://www.ncbi.nlm.nih.gov/nuccore/OQ624947; https://www.ncbi.nlm.nih.gov/nuccore/OQ624948; https://www.ncbi.nlm.nih.gov/nuccore/OQ624949; https://www.ncbi.nlm.nih.gov/nuccore/OQ624950; https://www.ncbi.nlm.nih.gov/nuccore/OQ624951; https://www.ncbi.nlm.nih.gov/nuccore/OQ624952; https://www.ncbi.nlm.nih.gov/nuccore/OQ624953; https://www.ncbi.nlm.nih.gov/nuccore/OQ624954.The datasets presented in this study can be found in online repositories. The names of the repository/repositories and accession number(s) can be found below: Ethical review and approval was not required for the animal study because this work used data from previous studies.Conceptualization, methodology, investigation, formal analysis, and writing—original draft preparation: TO. Formal analysis, writing—review and editing, funding acquisition, and project administration: DD. Conceptualization and supervision: JB. All authors contributed to the article and approved the submitted version.


Cystinosis, a rare lysosomal storage disease caused by mutations in the CTNS gene, is characterized by cystine crystallization and accumulation within multiple tissues, including kidney and brain. Its impact on neural function appears mild relative to its effects on other organs during early disease, but since therapeutic advances have led to substantially increased life expectancy, neurological implications are of increasing interest, necessitating deeper understanding of the impact of cystinosis on neurocognitive function. Behavioral difficulties have been reported in cystinosis in the visual domain. Very little is known, however, about how the brains of people living with cystinosis process visual information. This is especially interesting given that cystine accumulation in the cornea and posterior ocular structures is a hallmark of cystinosis.Here, high-density scalp electrophysiology was recorded to visual stimuli (during a Go/No-Go task) to investigate early visual processing in individuals with cystinosis, compared to age-matched controls. Analyses focused on early stages of cortical visual processing.The groups differed in their initial cortical response, with individuals with cystinosis exhibiting a significantly larger visual evoked potential (VEP) in the 130–150 ms time window. The groups also differed in the associations between neural responses and verbal abilities: While controls with higher IQ scores presented larger neural responses, that relationship was not observed in cystinosis.The enlarged VEP in cystinosis could be the result of cortical hyperexcitability and/or differences in attentional engagement and explain, at least partially, the visual and visual-spatial difficulties described in this population. Cystinosis is an autosomal recessive disorder caused by bi-allelic mutations in the 17p13.2-located CTNS gene  with an To reduce this gap in knowledge, our research team has focused on characterizing the impact of cystinosis on brain and cognitive function. Though abnormally high levels of cystine have been observed in different brain regions , cystinoHere, we expand this investigation to the visual sensory domain. Interestingly, visual-perceptual indices are often significantly lower than verbal indices in individuals with cystinosis . This paHere, we use high-density EEG to investigate basic visual processing in a group of individuals with cystinosis and compare them to a group of age-matched controls. The analyses focus on the visual evoked potential (VEP) component P1. P1 is an early VEP peaking around 100 ms following stimulus onset and has been associated with multiple generators in both dorsal and ventral visual streams . AdditioConsidering the behavioral difficulties reported in visual-related processing in cystinosis and the tendency for cystine accumulation in the retina, we hypothesized that individuals with cystinosis would show different early sensory-perceptual brain responses to visually presented stimuli, reflected in amplitude differences in the P1 component of the VEP. Identifying the processing stages that are impaired and contribute to visual and visual-spatial processing differences in cystinosis will be important in the development of impactful strategies that address visual processing difficulties and identify sensitive biomarkers of treatment efficacy on brain function.Thirty-eight individuals diagnosed with cystinosis  and 45 age-matched controls  were recruited. Individuals with cystinosis were recruited via social media and through contact with family organizations. Due to the rareness of cystinosis, most participants, all of whom lived within the United States, traveled from out-of-state to participate. Furthermore, the controls were recruited via flyers in the neighborhoods surrounding the lab and through a lab-maintained participant database. Developmental and/or educational difficulties or delays, neurological problems, and a severe mental illness diagnosis were exclusionary criteria for controls. Current neurological problems were exclusionary criteria for individuals living with cystinosis. To assess visual acuity, a Snellen chart was used. All participants had normal or corrected to normal vision. Nevertheless, all participants were asked at the start of the electrophysiological experimental session if they could see the stimuli and their different components without difficulty. One individual with cystinosis was excluded from the final sample due to illness on the scheduled day of testing. All individuals, and their legal guardian if under 18 years old, signed a consent form. Participants were monetarily compensated for their time. This study and all the associated procedures were approved by the Albert Einstein College of Medicine Institutional Review Board. All aspects of the research conformed to the tenets of the Declaration of Helsinki.Participation consisted of two visits, which involved completion of a cognitive function battery and EEG recordings. The cognitive function battery included the assessment of verbal and non-verbal intelligence  and executive functioning components  were presented in a pseudorandom sequence. Participants were instructed to press the left mouse button with the right index finger upon each stimulus presentation, as quickly and as accurately as possible, unless the stimulus was a repetition of the immediately preceding stimulus, in which case they should withhold their response . Stimuli, subtended 8.6° horizontally by 6.5° vertically, were presented centrally for 600 ms at an average rate of 1 per second . Three 12-minute blocks were run. Each block consisted of 540 trials, for a total of 1620 per participant. Here, we focus exclusively on hit trials, that is, trials that included a correct button press after stimulus presentation (only hits preceded by another hit were included), to ensure a good signal-to-noise ratio and to avoid overlap of processes related to inhibiting a response .tm, The Netherlands; 10–20 montage) and preprocessed using the EEGLAB toolbox (version 2021.0) (https://github.com/DouweHorsthuis)   for MATLrsthuis) . Preprocp-values (from t-tests and Spearman correlations) were submitted to Holm-Bonferroni corrections for multiple comparisons  by inspecting the timing and topography of the major voltage fluctuations in the grand averages. Mean amplitude data were used for both between-groups statistics and Spearman correlations. All parisons , using tage in R . Mixed-e package  in R .The averaged VEPs for P1 per channel and by group can be seen in rs=−.73, p = .01). As can be seen in rs=.40, p = .04), such correlation was not significant in cystinosis. P1 did not correlate significantly with non-verbal IQ, for either the control or the cystinosis group.Despite ample evidence for atypical visual processing in cystinosis in the neuropsychological literature  and clinIncreased early sensory-evoked potentials may reflect increased excitability in sensory cortices . An incrAlthough we think it unlikely, one cannot rule out the possibility that group differences in P1 amplitude, alternatively, reflect different levels of attentional engagement. Selective attention, most often in the context of visuo-spatial attention designs, has been shown to significantly modulate P1 amplitude . Such moP1 has been localized to sources in the dorsal extrastriate cortex, specifically to areas V3, V3a, and adjacent middle occipital gyrus and in the ventral extrastriate cortex, specifically area V4 in the fusiform gyrus  and it iThe increased amplitude VEP in cystinosis appears to be especially localized to the occipital and lateral parietal-occipital channels. While the current analyses focused on the channels in which response was maximal for both groups, those channels also represented the largest differences between the groups. As one can appreciate in Figure S1 , differences between the groups are reduced in lateral parietal-occipital channels and absent in mid-line parietal-occipital and across parietal channels. Future studies directed at defining the underlying neural sources explaining these differences are justified.Correlational analyses revealed that neural indices of visual sensory processing correlated with age in a similar fashion across groups. In the general population, VEPs attenuate in amplitude through at least late adolescence . Here, P1 attenuation was replicated in our control sample and was also observed in the cystinosis group. The groups differed, however, in the correlations between P1 and verbal IQ. While controls with higher IQ scores showed larger P1s, a significant relationship between P1 and verbal IQ was not present in the cystinosis group. P1 did not correlate significantly with non-verbal IQ, for either the control or the cystinosis group.Lastly, a brief detailing of findings relating to general cognitive function in cystinosis is merited. Neurocognitive assessments showed lower verbal and non-verbal IQs in individuals with cystinosis, when compared to their control peers. We and others had previously reported lower IQ scores in this population  and, as This study is not without limitations. First, our groups were not matched in terms of IQ, with the cystinosis group presenting significantly lower scores than the control group. Although there is no evidence of the association between early VEPs and IQ, such differences could have impacted the results. Second, variables related to current health status  and compliance with treatment, which has been linked to better clinical outcomes , were noTo conclude, here we present evidence of early visual processing differences in cystinosis which could contribute, at least partially, to both photosensitivity and to the behavioral visual-spatial difficulties described in this population. More work is needed to describe how very early visual processing differences might contribute to the cognitive profile associated with cystinosis. A better understanding of such associations could contribute to the identification of sensitive biomarkers of treatment efficacy on brain function. The current findings should motivate future studies utilizing paradigms tapping into higher- and lower-order visual processes and investigating visual processing and pathways in more depth, for instance, by employing tasks distinguishing between ventral and dorsal streams and magnocellular and parvocellular pathways. However, in so doing we believe it is important for future EEG research with this population to take sensitivity to light into consideration when designing visual experiments. Furthermore, these findings and their implications in classroom and professional settings utilizing digital media and screens should be further explored.


The impact of the perioperative estimated glomerular filtration rate (eGFR) on graft survival in kidney transplant recipients is yet to be evaluated. In this study, we developed prediction models for the ideal perioperative eGFRs in recipients.We evaluated the impact of perioperative predicted ideal and actual eGFRs on graft survival by including 1,174 consecutive adult patients who underwent living-donor kidney transplantation (LDKT) between January 2008 and December 2020. Prediction models for the ideal perioperative eGFR were developed for 676 recipients who were randomly assigned to the training and validation sets (ratio: 7:3). The prediction models for the ideal best eGFR within 3 weeks and those at 1, 2, and 3 weeks after LDKT in 474 recipients were developed using 10-fold validation and stepwise multiple regression model analyzes. The developed prediction models were validated in 202 recipients. Finally, the impact of perioperative predicted ideal eGFRs/actual eGFRs on graft survival was investigated using Fine–Gray regression analysis.The correlation coefficients of the predicted ideal best eGFR within 3 weeks and the predicted ideal eGFRs at 1, 2, and 3 weeks after LDKT were 0.651, 0.600, 0.598, and 0.617, respectively. Multivariate analyzes for graft loss demonstrated significant differences in the predicted ideal best eGFR/actual best eGFR within 3 weeks and the predicted ideal eGFRs/actual eGFRs at 1, 2, and 3 weeks after LDKT.The predicted ideal best eGFR/actual best eGFR within 3 weeks and the predicted ideal eGFRs/actual eGFRs at 1, 2, and 3 weeks after LDKT were independent prognostic factors for graft loss. Therefore, the perioperative predicted ideal eGFR/actual eGFR may be useful for predicting graft survival after adult LDKT. Specifically, donor and recipient characteristics, including donor age, recipient sex, and donor estimated glomerular filtration rate (eGFR), graft pathological features, and anti-human leukocyte antigen (HLA) donor-specific antibodies (DSAs) affect postoperative graft function . Postope2.2.1.This single-center retrospective cohort study was approved by the Nagoya Daini Red Cross Hospital’s Institutional Review Board  and was conducted following the principles of the Declaration of Helsinki. The study included 1,174 consecutive adult patients who underwent LDKT between January 2008 and December 2020. First, the impacts of the actual best eGFR within 3 weeks after LDKT and actual eGFRs at 1, 2, and 3 weeks and at 1, 3, 6, and 12 months after LDKT on graft survival were investigated in 1174 recipients. Second, prediction models were developed for the ideal best eGFR within 3 weeks and ideal eGFRs at 1, 2, and 3 weeks after LDKT. We developed prediction models based on 676 ideal recipients selected from 1,174 recipients. Finally, the impact of the predicted ideal best eGFR/actual best eGFR within 3 weeks and the predicted ideal eGFRs/actual eGFRs at 1, 2, and 3 weeks after LDKT on graft survival was investigated in 1174 recipients. This study was reported following the Strengthening the Reporting of Observational Studies in Epidemiology (STROBE) guidelines.2.2.This study included all consecutive recipients who underwent LDKT at our hospital between January 2008 and December 2020. The recipients were followed up until August 2021. Additionally, we excluded recipients with an immunosuppressive regimen using iscalimab in clinical trials (two recipients) . All don2.3.Living donors were selected according to the guidelines for living kidney donors in Japan . The lat2.4.LDKTs were performed following the Istanbul Declaration. The recipients stayed at the hospital for 3 weeks after LDKT. After discharge, postoperative recipient assessments were performed fortnightly for the first 3 months and subsequently monthly at our hospital and local hospitals. Protocol biopsies were performed at 1 h after reperfusion as a baseline, and at 1 month after KT.Data on donor and recipient characteristics and operative outcomes, actual eGFR after LDKT, graft survival, and recipient mortality were collected. These data were used to analyze the impact of the actual best eGFR within 3 weeks after LDKT as well as actual eGFRs at 1, 2, and 3 weeks and at 1, 3, 6, and 12 months after LDKT on graft survival. Additionally, to develop the prediction models for the ideal best eGFR within 3 weeks and ideal eGFRs at 1, 2, and 3 weeks after LDKT, data on donor and recipient characteristics and operative outcomes; perioperative adverse events; best eGFR within 3 weeks after LDKT; and actual eGFRs at 1, 2, and 3 weeks after LDKT were collected and analyzed. Furthermore, prediction models were developed for recipients with ideal graft conditions within 1 month after LDKT. Recipients who received grafts from donors with intraoperative adverse events; those who received transplanted grafts with arterial reconstruction or ligation of the thin upper pole artery; and those who experienced perioperative adverse events, conversion of the immunosuppressive regimen, recurrence of nephritis, calcineurin inhibitor toxicity, and rejection within 1 month were excluded from the development of the prediction models for ideal eGFRs within 3 weeks. The detailed reasons for excluding 498 recipients from the development of the prediction models are presented in 2.5.For the ABO-compatible KT, basiliximab, steroids, calcineurin inhibitors , and an antimetabolite or mammalian target of rapamycin inhibitor  were administered for induction and maintenance therapy. Desensitization was performed using rituximab or splenectomy, double-filtration plasmapheresis, and plasmapheresis for the ABO-incompatible KT. Basiliximab, steroids, and calcineurin inhibitors , and mycophenolate mofetil were administered for induction and maintenance therapy. Regarding the preformed-DSA KT, desensitization was performed using rituximab, double-filtration plasmapheresis, plasmapheresis, or intravenous immunoglobulin administration. Furthermore, basiliximab, steroids, calcineurin inhibitors , and mycophenolate mofetil were administered for induction and maintenance therapy.2.6.Statistical analyzes of donor and recipient characteristics were performed using the Kruskal–Wallis test and the chi-square or Fisher’s exact test for continuous and categorical variables, respectively. An estimation equation model was constructed to predict the eGFR. The independent variables used in the estimation equation were initially tested for collinearity in advance, and factors with collinearity were excluded to prevent overfitting the model. Subsequently, estimation equations were constructed on the training set and confirmed using the validation set. The patients were randomly categorized into two groups in a 7:3 ratio, of whom 474 and 202 were assigned to the training and validation sets, respectively .A linear regression prediction model was constructed using the eGFR as the dependent variable of the training set to establish an equation for estimating the eGFR. Subsequently, a stepwise method with 10-fold validation was used to limit the variables to be included in the model, and the estimation accuracy was evaluated. The R and R-squared values were used to estimate the accuracy. Finally, the constructed estimation equations were evaluated for their accuracy on the validation set.p-value <0.05 in the univariate logistic regression analysis were used in the multivariate logistic regression analysis. Statistical significance was set at 0.05 (two-sided). All analyzes were performed using the Statistical Package for the Social Sciences  and R version 4.0.3 .A Fine–Gray competing risk regression model was used to determine the prognostic factors for graft loss. The proportional hazard assumption was confirmed using a log–log plot for the Fine–Gray competing risk regression model. No interaction effects between the variables were found in the models using the interaction items. Covariates with a 3.3.1.Overall, 1,176 adult LDKTs were performed at our hospital during this study, of which two LDKTs were excluded, and the remaining 1,174 recipients were included. The 1,174 recipients were followed up between January 2008 and August 2021  and were included in the final analysis.3.2.3.2.1.p = 0.002); donation to first-degree relative recipients (p = 0.001); preoperative comorbidities ≥1  (p = 0.015); preoperative systolic blood pressure (p = 0.003); preoperative diastolic blood pressure (p = 0.023); preoperative hemoglobin A1c level (p = 0.039); preoperative BMI (p = 0.027); preoperative urine albumin/creatine ratio (p = 0.014); and baseline biopsy findings at 1 h after transplantation  (p = 0.048) ; cause of end-stage renal disease (p = 0.019); follow-up period (p < 0.001); transplantation from first-degree relative donors (p = 0.001); preoperative flow cytometry B cell crossmatch positivity (p = 0.010); dialysis vintage (p < 0.001); HLA-AB mismatch (p = 0.010); calcineurin inhibitor administration at KT (p < 0.001); calcineurin inhibitor administration at the best eGFR within 3 weeks after KT (p < 0.001); calcineurin inhibitor administration at 1, 2, and 3 weeks after KT ; mycophenolate mofetil, mizoribine, or everolimus administration at transplantation (p = 0.049); actual best eGFR within 3 weeks (p = 0.039); actual eGFRs at 1 and 2 weeks and 3, 6, and 12 months ; recurrence of nephritis (p = 0.013); de novo DSA (p < 0.001); rejection (p = 0.007); and recipient death (p < 0.001).Regarding the recipient characteristics, significant differences were observed in recipient age (3.2.2.p = 0.020) and operation methods (p < 0.001). In the recipient operation, significant differences were observed in cold ischemia time (p < 0.001), delayed graft function (p < 0.001), and occurrence of arterial thrombosis (p = 0.001), lymphocele (p < 0.001), incisional hernia (p = 0.007), and severe pneumonia (p = 0.001).The operative outcomes of the donors and recipients are presented in 3.2.3.Graft loss was identified in 73 recipients . Death with functioning grafts was observed in 42 recipients .3.2.4.p = 0.032); preformed DSA (p = 0.013); preoperative desensitization ; actual eGFR at 6 months after LDKT (p = 0.003); actual eGFR at 12 months after LDKT (p < 0.001); and donor age (p = 0.048). p = 0.015, hazard ratio [HR]: 0.946, 95% confidence interval [CI]: 0.904–0.989, p < 0.001; HR: 0.937, 95% CI: 0.907–0.967).The results of the univariate Fine–Gray competing risk regression model for graft loss are presented in 3.2.5.Details of the recipients who met the inclusion and exclusion criteria for developing prediction models are presented in p = 0.042) and preoperative flow cytometry T cell crossmatch (p = 0.033). The donor and recipient characteristics and operative outcomes for the training and validation sets are presented in 3.2.6.p = 0.032); preformed DSA (p = 0.013); preoperative desensitization (p = 0.028); predicted ideal best eGFR/actual best eGFR within 3 weeks after LDKT (p < 0.001); predicted ideal eGFRs/actual eGFRs at 1, 2, and 3 weeks after LDKT ; and donor age (p = 0.048). p < 0.001, HR: 1.496, 95% CI: 1.225–1.826; p = 0.006, HR: 1.309, 95% CI: 1.079–1.588; p = 0.002, HR: 1.323, 95% CI: 1.105–1.584; and p < 0.001, HR: 1.452, 95% CI: 1.240–1.699, respectively). In The results of the univariate Fine–Gray competing risk regression model for graft loss are presented in 4.This study suggests that the actual eGFRs at 6 and 12 months after LDKT could be an independent risk factor for graft loss, although the actual eGFR within 3 months after LDKT does not seem to be a risk factor. However, the predicted ideal best eGFR/actual best eGFR within 3 weeks after LDKT and the predicted ideal eGFRs/actual eGFRs at 1, 2, and 3 weeks after LDKT might be independent prognostic factors for graft loss.de novo DSA, rejection, graft loss, and death with functioning graft rates during the median observation period of 77.0 months were 11.0, 3.3, 6.2, and 3.6%, respectively. Interestingly, these results are similar to those of previous reports from other countries  recipients and donors, the race composition differed from those reported previously, and the BMI values of the recipients and donors were lower than those reported in previous works from different countries . In Japaountries . In thisountries , 35. ThiThe eGFR at 1 year after KT could be a prognostic factor for graft loss , 10–17. Notably, the prediction models for ideal eGFRs at 1, 2, and 3 weeks after LDKT and the ideal best eGFR within 3 weeks were developed using 10-fold cross-validation and stepwise multiple regression model analysis. Ideal KTs were selected by excluding problematic donors and recipients during the perioperative period. Finally, data from 676 recipients were used to develop prediction models for ideal eGFRs during this period. This study is novel because no studies to date have investigated prediction models for ideal eGFRs during the perioperative period. During the development of the prediction models, the trough levels of tacrolimus and extended-release tacrolimus were separately presented, as they were found to be significantly different when the same dose was administered in a previous study .P-values in the multivariate Fine–Gray competing model analysis for graft loss, adjusted for male recipient, preformed DSA, preoperative desensitization, and donor age, decreased as the time after KT passed. This may imply that the widening disparities of the actual eGFR after KT between the graft loss and non-graft loss groups did not contribute to graft loss prediction until 6 months after KT. However, it may be useful to reveal the predictor for graft loss earlier and implement measures based on the results. Therefore, the predicted ideal eGFR/actual eGFR was successfully developed to make the eGFRs at 1, 2, and 3 weeks more useful predictors for graft loss. This finding enabled the detection of slightly widening disparities of eGFR after KT between the graft loss and non-graft loss groups, which could not be detected using the actual eGFR after KT.Overfitting of the model was prevented using 10-fold cross-validation , 44. TheMany factors might prevent recipients from obtaining an ideal eGFR during the perioperative period, including rejection, delayed graft function, and operative complications , 46, 47.Furthermore, considering the recent advancements in artificial intelligence technology, the development of tools for predicting eGFR after KT using data from large-scale multicenter studies is expected. Therefore, this study’s results, which suggest the potential utility of a predictive tool for the ideal eGFR rather than relying solely on the actual eGFR, can lead to the advancement of innovative studies in the field of KT.The retrospective design of the study and the fact that it was conducted in a single institution to examine the impact of predicted eGFRs on graft survival were limitations of this work. Therefore, a prospective multicenter randomized study focusing on the effects of predicted ideal eGFRs/actual eGFRs on graft survival should be conducted to verify the results and elucidate the causes of failure to obtain ideal eGFRs.In conclusion, the predicted ideal eGFRs/actual eGFRs at 1, 2, and 3 weeks after LDKT and the predicted ideal best eGFR/actual best eGFR within 3 weeks may forecast graft survival after adult LDKT. Therefore, obtaining an ideal perioperative eGFR is crucial for improving long-term graft survival.The raw data supporting the conclusions of this article will be made available by the authors, without undue reservation.The studies involving humans were approved by Nagoya Daini Red Cross Hospital’s Institutional Review Board . The studies were conducted in accordance with the local legislation and institutional requirements. Written informed consent for participation was not required from the participants or the participants’ legal guardians/next of kin in accordance with the national legislation and institutional requirements.TH designed and acquired the data, interpreted the results, and drafted the manuscript. YH, MO, YM, AT, and TK acquired the data. KF, NG, TI, and SN interpreted the results. KU and YW approved the final version of the manuscript. All authors contributed to the article and approved the submitted version.The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.All claims expressed in this article are solely those of the authors and do not necessarily represent those of their affiliated organizations, or those of the publisher, the editors and the reviewers. Any product that may be evaluated in this article, or claim that may be made by its manufacturer, is not guaranteed or endorsed by the publisher.https://www.frontiersin.org/articles/10.3389/fmed.2023.1187777/full#supplementary-materialThe Supplementary material for this article can be found online at: Click here for additional data file.


New England Journal of Medicine (NEJM) Journal Watch is a prominent example of this format [3], but despite its wide adoption, little research has examined the effectiveness of this model as an educational tool.Staying apprised of the scientific literature can be a challenge for health science researchers and clinical practitioners alike . Journal surveillance is a popular modality for disseminating curated topic-specific health science research in a scheduled newsletter. The We conducted a pilot study examining the impact of journal surveillance as an educational tool within the University of California San Diego’s (UCSD) Division of Infectious Diseases. Modeled after the NEJM Journal Watch, we created an internal monthly newsletter summarizing the latest research in the field of infectious diseases (ID). We then surveyed readers to evaluate the content covered in article summaries, the barriers and facilitators to learning from the newsletter, and the impact on self-reported clinical knowledge and practice.Across 10 monthly editions we summarized 45 articles covering a diverse array of content topics published in high impact journals . Thirty-two (71.1%) summaries included an infographic or visual abstract. Eighteen ID division members completed the survey evaluation of the monthly newsletter; most were fellow physicians or early career faculty . Thirteen respondents (71.1%) had read 4 or more editions. Most (94.4%) viewed ID Journal Watch favorably, citing the ability to remain up to date with literature and to improve clinical care after reading the newsletter . Eleven (61.1%) reported that their main barrier to engaging with the newsletter was a lack of time. Infographics were viewed favorably by a majority (66.7%) as a learning tool, supporting previous findings that visual media can decrease cognitive load when interpreting new information [4].Figure 1Article topics and journals surveyed from 45 article summariesFigure 2Demographics of survey respondents, n = 18 (%)Figure 3Self-reported benefits of engaging with ID Journal Watch, n = 18Journal surveillance is a valuable learning tool particularly for trainees and early career faculty. The format allows for rapid acquisition of knowledge that is relevant to clinical care. Visual media should remain a key component of journal surveillance due to its ability to facilitate comprehension.All Authors: No reported disclosures


Objective: Compare biomechanical properties of femurs implanted with either BioMedtrix™ biological fixation with interlocking lateral bolt (BFX®+lb) or cemented (CFX®) stems when subjected to 4-point bending or axial torsional forces.Study Design: Twelve pairs of normal medium to large cadaveric canine femora were implanted with a BFX + lb (n = 12) and a CFX (n = 12) stem–one in the right and one in the left femora of the pair. Pre- and post-operative radiographs were made. Femora were tested to failure in either 4-point bending (n = 6 pairs) or axial torsion (n = 6 pairs), and stiffness, load or torque at failure, linear or angular displacement, and fracture configuration were noted.Results: Implant position was acceptable in all included femora, but CFX stems were placed in less anteversion than BFX + lb stems in the 4-point bending group (median (range) 5.8 (−1.9–16.3) vs. 15.9 (8.4–27.9) anteversion, respectively (p = 0.04)). CFX implanted femora were more stiff than BFX + lb implanted femora in axial torsion (median (range) 2,387  vs. 1,192  N*mm/o, respectively (p = 0.03)). One of each stem type, from different pairs, did not fail in axial torsion. There was no difference in stiffness or load to failure in 4-point bending, or in fracture configuration for either test, between implant groups.Conclusion: Increased stiffness of CFX implanted femurs under axial torsional forces may not be clinically relevant as both groups withstood expected in vivo forces. Based on this acute post-operative model using isolated forces, BFX + lb stems may be a suitable replacement for CFX stems in femurs with normal morphology (stovepipe and champagne flute morphology were not tested). Canine hip dysplasia (CHD) is a common orthopedic condition in dogs . There aOriginally, THR was performed by cementing implants into prepared cavities in the femur and acetabulum . A major®, BioMedtrix™ ) and cementless ) total hip replacement implant systems are available  fail at higher loads and 2) have higher stiffness than the BFX + lb implanted femurs in both 4-point bending and axial torsional testing. We also hypothesized that 3) 4-point bending would induce a fracture at the distal aspect of the stem regardless of stem type, and 4) axial torsional loads would induce a spiral fracture that would originate from the osteotomy in CFX implanted femurs and from the bolt hole in BFX + lb implanted femurs.This study was approved by the University of Florida Institutional Animal Care and Use Committee. Dogs were euthanized for reasons unrelated to the study and donated to research purposes. Paired femora were harvested from adult medium to large dogs with normal to mildly dysplastic coxofemoral joints, and soft tissues were removed. Pairs were excluded if orthopedic disease beyond coxofemoral laxity or mild osteophytosis of the femoral head and/or acetabulum was present in the hip joint; no pairs were included with moderate to severe osteophytosis or moderate to severe femoral neck thickening/shortening. Orthogonal radiographs were made and radiographic skeletal maturity and bone health was confirmed–any pairs with open physes or bony lesions such as trauma or neoplasia were excluded. Stem size was estimated by calibrating the cranial-caudal radiograph and overlaying the BFX stem acetate templates of increasing sizes; the stem size that allowed a 1–2 mm gap between the stem and the cortex at the level of the porous-smooth junction and distally, with the shoulder of the stem at the level of the proximal 1/3 of the greater trochanter was chosen . Only fea was mixed under vacuumb, a cement plug was inserted, a cement gun was used to deliver cement from distal to proximal with manual pressurization, and the stem  was guided into the femoral canal by hand and secured manually until the cement was set. Post-operative orthogonal radiographs were made and the femora were wrapped in saline (0.9% NaCl) soaked gauze and stored at −5°C until preparation for mechanical testing. The femora were thawed at room temperature overnight, then three screws  were placed in the distal metaphysis of each femur, which were left protruding to serve as anchors in the potting materialc. Femora were potted at the distal end using uniform square cardboard molds such that the long axis of the femur was perpendicular to the bottom of the mold . The proximal end was not potted. Potted femora were stored at 10 °C and mechanical testing was performed the following day to ensure that the potting material was fully set. A minimum of 2 days passed between stem implantation and biomechanical testing.After pre-operative radiographs, femora were wrapped in saline (0.9% NaCl) soaked gauze and stored at −5°C until implantation. Femora were thawed to room temperature overnight, then femoral canals were prepared and stems implanted as previously described . For eacvice versa for a valgus stem position . Femoral length was measured from the proximal-most aspect of the greater trochanter to the distal-most aspect of the lateral condyle on the cranial-caudal radiographic projection. Femoral CFI was calculated as the ratio between canal width at the lesser trochanter and at the narrowest point of the isthmus and any femurs with CFI less than 1.8 (stovepipe morphology) or greater than 2.5 (champagne flute morphology) were excluded. Representative post-operative radiographs are shown in position . A craniped stem . Prosthed The MTS machine is equipped with an axial-torsional load cell and axial force and torque were measured with an axial torsional load transducer with 15 kN axial, 150 Nm torsional load limits. Each construct was tested to failure. A high-definition digital video camerae was used to record fracture propagation, including the location of initiation of the fracture when possible. The cranial surface of the bone was facing the camera for 4-point bending tests and the lateral surface of the bone was facing the camera for torsional testing.Custom fixtures were created for each test, for use in a servo-hydraulic materials testing (MTS) machine. The 4-point bending fixture was manufactured from 6061 T6 aluminum . The basThe torsion fixture was designed based on previous studies using a machined aluminum block that stabilized the femoral head and neck and prevented slipping of the prosthesis during testing . Pozzi  The boneFractures were categorized by examination immediately after testing, palpation of stem motion, and review of the testing video in slow motion. Post-testing photographs were obtained of the cranial, medial, caudal, and lateral bone surfaces. Fractures were categorized based on the Vancouver Classification . Brady For 4-point bending, stiffness was calculated based on the first 100 N of the linear portion of the load/displacement curve (a standardized portion of the curve prior to elastic deformation). Load (N) and displacement (mm) at failure were defined as the load and linear displacement at which the fracture was first initiated and was associated with a sudden decrease in load. Stiffness and load at failure were subjectively compared between grades of cement mantles in CFX implanted femora.For axial torsion, stiffness was calculated based on the first 5000 N*mm of the linear portion of the load/displacement curve (a standardized portion of the curve prior to elastic deformation). Torque (N*mm) and angular displacement (o) failure were defined as the torque and displacement at which fracture was first initiated and was associated with a sudden decrease in torque. Stiffness and torque at failure were subjectively compared between grades of cement mantles in CFX implanted femora.p ≤ 0.05 was considered statistically significant.Non-parametric tests were used to avoid assumption of normality in statistical calculations, due to small sample size. Femoral morphology, stiffness, load at failure, and displacement at failure were compared between BFX + lb and CFX implanted paired femora using a related samples Wilcoxon signed rank test, and implant position was compared using a Wilcoxon signed rank test (SPSS). Twelve pairs of femora were distributed into testing groups for inclusion in the final data set: six pairs were tested in 4-point bending and six pairs were tested in torsion . FemoralThere was no difference in stiffness, force to ultimate failure, or displacement at ultimate failure between implant systems . Sample The fracture pattern was variable. In BFX + lb implanted femora, three were Vancouver class B1 , two were Vancouver class B2  and one was a Vancouver class C fracture. The fracture pattern for CFX implanted femora was more consistent: five were Vancouver class B1  and one was a Vancouver class B2 fracture .Femora implanted by CFX were stiffer in torsion compared to femora implanted by BFX + lb . There wThe fracture pattern was less variable in femora that failed in axial torsion (Five BFX + lb and five CFX implanted femurs). In BFX + lb implanted femora, two were Vancouver class B1 and three were Vancouver class B2 fractures. All were spiral fractures; two originated from the bolt hole and from the medial aspect of the osteotomy and three originated from just the medial aspect of the osteotomy with the bolt hole remaining intact. In CFX implanted femora, two were Vancouver class B1 and three were Vancouver class B2 fractures (loose at stem-cement interface). All were spiral fractures originating from the osteotomy.For CFX implanted femora, cement mantle varied from grade A to C with most having grade B cement mantle quality . When stThe BFX + lb stem was developed, in part, to replace the need for the use of the CFX femoral system in some situations such as a stovepipe femoral morphology . Direct in vivo situation where the cement mantle surrounding the CFX implant is at its strongest (the stem-cement interface has not yet started to loosen) but the press-fit BFX + lb implanted femur is at its weakest (the implant is not yet osteointegrated). Proper cementing technique will force the cement into the interdigitations of the cancellous bone  was similar to slightly higher than previously reported values for standard BFX stems   or Zuricous bone , and the grading . In addi walking . Alternain vivo forces that would be experienced by similarly sized dogs (even after resolution of weight bearing forces into bending and other forces). Therefore, we conclude that both BFX + lb and CFX implanted femora can withstand the lateral tensile and medial compressive forces experienced during walking, immediately after prosthesis implantation. Importantly, the bending test design used here did not include the proximal femur where the stem enters the bone and where the lateral bolt is incorporated into the construct and a different study design such as placing the bending force directly on the head of the implant may reveal entirely different conclusions.There was no difference between BFX + lb and CFX implanted femora when tested in 4-point bending. The median loads at ultimate failure were >4,000 N, and all constructs failed at >3,000 N. A prior study that implanted instrumented hip replacement prostheses and femoral cortical strain gauges into 25–35 kg dogs determined that the maximum net force on the femur was up to 1.65 times body weight during stance phase of the walking gait, which was roughly resolved into lateral tension, medial compression, and internal rotation . In the Fracture configuration was not different between BFX + lb and CFX treatment groups in the torsional test based on the Vancouver classification, however the fracture mechanism may be different between treatment groups. Fracture occurs in BFX implanted femurs under torsional loads because the stem has an oval-shaped cross-section. As torsional force is applied to the implant head, the BFX stem rotates within the medullary cavity and the diameter of the implant will eventually exceed that of the bone in the sagittal plane. With the addition of the lateral bolt to the BFX stem, the lateral bolt was noted to contact the cranial border of the hole in the lateral cortex, and the presence of the hole likely acts as a stress riser. In contrast, as the CFX stem rotated, the rotation was translated through the cement to the cortical bone and the cortical bone was noted to twist with the implant to some degree. Despite the potential differences in mechanism of fracture, the fracture configuration was again similar between treatment groups, although the fracture did originate from the bolt hole in two BFX + lb implanted femurs. Three CFX stems were loose after torsional testing; the instability was noted to be at the stem-cement interface rather than the cement-bone interface. Loosening in clinical cases of aseptic loosening also primarily occurs at the stem-cement interface , which iFracture configuration was also not different between BFX + lb and CFX treatment groups in the 4-point bending test. The 4-point bending test applies a uniform bending moment between the load (inside) rollers , which apost hoc analysis, at least seven paired failed samples would be needed to demonstrate a difference in torque at ultimate failure and we were unable to obtain additional paired samples to achieve this number. Additional clinically relevant tests could include axial loading through the head of the implant or a cyclic loading of walk, trot, gallop, or jumping forces to replicate daily activities–the acute load to failure test performed here does not replicate in vivo forces and therefore the results must be interpreted carefully. The 4-point bending test does not test the portion of the bone proximal or distal to the load (inside) rollers and therefore we were not able to draw conclusions about the effect of the presence of the lateral bolt and lateral bolt hole in the BFX + lb implanted femora. While both the 4-point bending and torsional tests were designed to apply a purely bending or torsional load, respectively, it is unlikely that we achieved this as the shape of the femur is not a straight column, each pair of bones is unique, each bone is a mirror image of the contralateral bone, and the potting and positioning technique was ultimately subjective despite every attempt at accuracy. There was a difference in version angle between implant groups tested in 4-point bending and there may be a type 2 statistical error preventing identification of a difference in version angle between groups tested in axial torsion. It is not clear exactly what effect this may have had on the results, though it should be noted that this is unlikely to have affected results for 4-point bending, and for axial torsion the femur was able to be loaded into the testing machine to accommodate for variations in version as the base attachment was able to rotate prior to clamping to the base of the machine. The BFX + lb and CFX stems are created using different metals  which have different biomechanical properties but because they are used interchangeably within the size ranges we reported this is not a limitation but rather a representation of the clinical situation. Importantly, the femurs in this study had CFIs between 1.81–2.24 , rather than stovepipe (CFI < 1.8) or other morphologies that would indicate that either a CFX or BFX + lb stem would be necessitated and therefore we cannot make conclusions regarding differences between these implant types in morphologies other than normal cadaveric femurs. Cadaver acquisition is increasingly challenging at our institution and during the entire collection period, no stovepipe femurs were obtained and we were unable to add paired femurs to increase sample size to meet a sample size that may have shown more statistical significance as implied by post-hoc analysis. It may be that a model to replicate stovepipe morphology and provide higher sample numbers, such as a 3D printed model, may prove to be relevant for studies such as this one. Lastly, these results can only be extrapolated to the immediately post-operative clinical scenario at most. For example, it is not known whether a BFX implant with reduced stiffness could be experiencing micromotion leading to loosening over time, and typically osteointegration will occur and strengthen BFX constructs and loosening will occur and weaken CFX constructs over time, as well as complex bone resorption and formation after either cemented or uncemented total hip replacement; all of these temporal variables will change the stiffness and failure parameters.This study has many limitations that must be considered. A type 2 statistical error may be present and a larger sample size may have revealed more significant differences between treatment groups, especially with regards to torque at ultimate failure in torsion as only five femurs failed in each implant group resulting in four comparable pairs. According to in vivo. While we suspect that both constructs should withstand in vivo forces despite the difference in stiffness, due to the differences between acute load to failure test and the cyclic loading experienced in vivo, we cannot definitively conclude whether this statistical difference is clinically relevant. Based on this study, the BFX + lb system is suspected to be interchangeable with the CFX system when applied to normal femora, although additional bending tests to incorporate the entire proximal femur and lateral bolt hole, axial compression tests, and torsional testing  could also be performed, both to failure and non-destructive cyclic testing, for further evidence. Additionally, further testing would need to be performed in order to ascertain whether this conclusion remains true and whether other differences are identified when these methods are applied to femurs with stovepipe morphology as this morphology is one of the morphologies where the BFX + lb stem is promoted for use but not yet proven to be safe.In conclusion, CFX implanted normal cadaveric femurs were shown to have higher stiffness than BFX + lb implanted normal cadaveric femurs when tested in torsion and both CFX and BFX + lb implanted femurs failed at loads higher than experienced