Immunotherapy for hepatocellular carcinoma:Current and future

Hepatocellular carcinoma(HCC)arises on the background of chronic liver disease.Despite the development of effective anti-viral therapeutics HCC is continuing to rise,in part driven by the epidemic of non-alcoholic fatty liver disease.Many patients present with advanced disease out with the criteria for transplant,resection or even locoregional therapy.Currently available therapeutics for HCC are effective in a small minority of individuals.However,there has been a major global interest in immunotherapies for cancer and although HCC has lagged behind other cancers,great opportunities now exist for treating HCC with newer and more sophisticated agents.Whilst checkpoint inhibitors are at the forefront of this revolution,other therapeutics such as inhibitory cytokine blockade,oncolytic viruses,adoptive cellular therapies and vaccines are emerging.Broadly these may be categorized as either boosting existing immune response or stimulating de novo immune response.Although some of these agents have shown promising results as monotherapy in early phase trials it may well be that their future role will be as combination therapy,either in combination with one another or in combination with treatment modalities such as locoregional therapy.Together these agents are likely to generate new and exciting opportunities for treating HCC,which are summarized in this review.

indocyanine green-based fluorescence imaging in visceral and hepatobiliary and pancreatic surgery:State of the art and future directions

In recent years, the use of fluorescence-guided surgery(FGS) to treat benign and malignant visceral, hepatobiliary and pancreatic neoplasms has significantly increased. FGS relies on the fluorescence signal emitted by injected substances(fluorophores) after being illuminated by ad hoc laser sources to help guide the surgical procedure and provide the surgeon with real-time visualization of the fluorescent structures of interest that would be otherwise invisible. This review surveys and discusses the most common and emerging clinical applications of indocyanine green(ICG)-based fluorescence in visceral, hepatobiliary and pancreatic surgery. The analysis, findings, and discussion presented here rely on the authors' significant experience with this technique in their medical institutions, an up-to-date review of the most relevant articles published on this topic between 2014 and 2018, and lengthy discussions with key opinion leaders in the field during recent conferences and congresses. For each application, the benefits and limitations of this technique, as well as applicable future directions, are described. The imaging of fluorescence emitted by ICG is a simple, fast,relatively inexpensive, and harmless tool with numerous different applications in surgery for both neoplasms and benign pathologies of the visceral and hepatobiliary systems. The ever-increasing availability of visual systems that can utilize this tool will transform some of these applications into the standard of care in the near future. Further studies are needed to evaluate the strengths and weaknesses of each application of ICG-based fluorescence imaging in abdominal surgery.

Adenomyomatosis of the gallbladder in childhood: A systematic review of the literature and an additional case report

AIM: To investigate the diagnostic and therapeutic assessment in children with adenomyomatosis of the gallbladder(AMG).METHODS: AMG is a degenerative disease characterized by a proliferation of the mucosal epithelium which deeply invaginates and extends into the thickened muscular layer of the gallbladder, causing intramural diverticula. Although AMG is found in up to 5% of cholecystectomy specimens in adult populations, this condition in childhood is extremely uncommon. Authors provide a detailed systematic review of the pediatric literature according to PRISMA guidelines, focusing on diagnostic and therapeutic assessment. An additional case of AMG is also presented. RESULTS:Five studies were finally enclosed, encompassing 5 children with AMG. Analysis was extended to our additional 11-year-old patient, who presented diffuse AMG and pancreatic acinar metaplasia of the gallbladder mucosa and was successfully managed with laparoscopic cholecystectomy. Mean age at presentation was 7.2 years. Unspecific abdominal pain was the commonest symptom. Abdominal ultrasound was performed on all patients, with a diagnostic accuracy of 100%. Five patients underwent cholecystectomy, and at follow-up were asymptomatic. In the remaining patient, completely asymptomatic at diagnosis, a conservative approach with monthly monitoring via ultrasonography was undertaken. CONCLUSION: Considering the remote but possible degeneration leading to cancer and the feasibility of laparoscopic cholecystectomy even in small children, evidence suggests that elective laparoscopic cholecystectomy represent the treatment of choice. Preoperative evaluation of the extrahepatic biliary tree anatomy with cholangio-MRI is strongly recommended.

Fixed bimonthly aflibercept in nave and switched neovascular age-related macular degeneration patients:one year outcomes

AIM: To determine real life clinical outcomes in poorly responsive and treatment-nave neovascular age-related macular degeneration(nv AMD) patients using bimonthly fixed dosing aflibercept regimen.METHODS: This was a retrospective study of 165 eyes with nv AMD started on aflibercept at Southampton Eye Unit between June 2013 and June 2014. Patients were either switched from pro re nata(PRN) ranibizumab/bevacizumab due to poor response(107 eyes), or treatment- nave( 58 eyes). Patients initially received 3-monthly intravitreal aflibercept injections followed by 2-monthly fixed doses. Clinic visits were scheduled at month 0, 4, 10 and 12. Mean change in best-corrected visual acuity(BCVA) and central retinal thickness(CRT)from baseline were assessed using the Wilcoxon signedrank test. The proportion of patients maintaining BCVA(<15 letters loss) at 12 mo was also evaluated.RESULTS: Mean BCVA change at month 12 was +3.29 and +4.67 letters in the switched and nave aflibercept groups respectively(P <0.01). BCVA was maintained in 95.3% of switched and 96.6% of nave patients. CRT at month 12 showed a decrease of -6.16 μm in the switched group and -35.36 μm in the nave group(P <0.01).Patients previously treated with ranibizumab/bevacizumab had on average received 7.4 ranibizumab/bevacizumab injections over 12.6 mo, attending 10 clinic visits. The fixed dosing aflibercept regimen required an average of 7.1 injections(nave group), 7.5 injections(switched group) and 4 clinic visits per year.CONCLUSION: Fixed bimonthly aflibercept is effective in both treatment-nave and poorly responsive nv AMD patients. Adopting a fixed dosing regimen can reduce patient burden without compromising on outcomes.

Longitudinal analysis of inflammation and microbiota dynamics in a model of mild chronic dextran sulfate sodium-induced colitis in mice

AIM:To characterize longitudinally the inflammation and the gut microbiota dynamics in a mouse model of dextran sulfate sodium(DSS)-induced colitis.METHODS:In animal models,the most common method used to trigger colitis is based on the oral administration of the sulfated polysaccharides DSS.The murine DSS colitis model has been widely adopted to induce severe acute,chronic or semi-chronic colitis,and has been validated as an important model for the translation of mice data to human inflammatory bowel disease(IBD).However,it is now clear that models characterized by mild intestinal damage are more accurate for studying the effects of therapeutic agents.For this reason,we have developed a murine model of mild colitis to study longitudinally the inflammation and microbiota dynamics during the intestinal repair processes,and to obtain data suitable to support the recovery of gut microbiota-host homeostasis.RESULTS:All plasma cytokines evaluated,except IL-17,began to increase(P<0.05),after 7 d of DSS administration.IL-17 only began to increase 4 d after DSS withdrawal.IL-1βand IL-17 continue to increase during the recovery phase,even when clinical signs of colitis had disappeared.IL-6,IL-10 and IFN-γreached their maxima 4 d after DSS withdrawal and decreased during the late recovery phase.TNFαreached a peak(a three-fold increase,P<0.05),after which it slightly decreased,only to increase again close to the end of the recovery phase.DSS administration induced profound and rapid changes in the mice gut microbiota.After 3 d of DSS administration,we observed a major reduction in Bacteroidetes/Prevotella and a corresponding increase in Bacillaceae,with respect to control mice.In particular,Bacteroidetes/Prevotella decreased from a relative abundance of 59.42%-33.05%,while Bacillaceae showed a concomitant increase from 2.77%to 10.52%.Gut microbiota rapidly shifted toward a healthy profile during the recovery phase and returned normal 4 d after DSS withdrawal.Cyclooxygenase 2 expression started to increase 4 d after DSS withdrawal(P<0.05),when dysbiosis had recovered,and continued to increase during the recovery phase.Taken together,these data indicated that a chronic phase of intestinal inflammation,characterized by the absence of dysbiosis,could be obtained in mice using a single DSS cycle.CONCLUSION:Dysbiosis contributes to the local and systemic inflammation that occurs in the DSS model of colitis;however,chronic bowel inflammation is maintained even after recovery from dysbiosis.

Systems biology applications to study mechanisms of human immunodeficiency virus latency and reactivation

Eradication of human immunodeficiency virus(HIV) in infected individuals is currently not possible because of the presence of the persistent cellular reservoir of latent infection. The identification of HIV latency biomarkers and a better understanding of the molecular mechanisms contributing to regulation of HIV expression might provide essential tools to eliminate these latently infected cells. This review aims at summarizing gene expression profiling and systems biology applications to studies of HIV latency and eradication. Studies comparing gene expression in latently infected and uninfected cells identify candidate latency biomarkers and novel mechanisms of latency control. Studies that profiled gene expression changes induced by existing latency reversing agents(LRAs) highlight uniting themes driving HIV reactivation and novel mechanisms that contribute to regulation of HIV expression by different LRAs. Among the reviewed gene expression studies, the common approaches included identification of differentially expressed genes and gene functional category assessment. Integration of transcriptomic data with other biological data types is presently scarce, and the field would benefit from increased adoption of these methods in future studies. In addition, designing prospective studies that use the same methods of data acquisition and statistical analyses will facilitate a more reliableidentification of latency biomarkers using different model systems and the comparison of the effects of different LRAs on host factors with a role in HIV reactivation. The results from such studies would have the potential to significantly impact the process by which candidate drugs are selected and combined for future evaluations and advancement to clinical trials.

Impaired lysosomes in the retinal pigment epithelium play a central role in the degeneration of the neuroretina

Lysosomes are highly dynamic, single membranebound compartments that are critical for maintaining cellular homeostasis. These organelles, which appear to vary between 200 nm–1 μm in diameter, originate from the maturation of endocytic vesicles and via the enrichment of newly synthesized lysosomal proteins in the trans-Golgi network.

The complexities underlying age-related macular degeneration： could amyloid beta play an important role？

e-related macular degeneration （AMD） causes irreversible loss of central vision for which there is no effective treatment. Incipient pathology is thought to occur in the retina for many years before AMD manifests from midlife onwards to affect a large proportion of the elderly. Although genetic as well as non-genetic/environmental risks are recognized, its complex aetiology makes it difficult to identify susceptibility, or indeed what type of AMD develops or how quickly it progresses in different individuals. Here we summarize the literature describing how the Alzheimer＇s-linked amyloid beta （Aβ） group of misfolding proteins accumulate in the retina. The discovery of this key driver of Alzheimer＇s disease in the senescent retina was unexpected and surprising, enabling an altogether different perspective of AMD. We argue that Aβ fundamentally differs from other substances which accumulate in the ageing retina, and discuss our latest findings from a mouse model in which physiological amounts of Aβ were subretinally-injected to recapitulate salient features of early AMD within a short period. Our discoveries as well as those of others suggest the pattern of Aβ accumulation and pathology in donor aged/AMD tissues are closely reproduced in mice, including late-stage AMD phenotypes, which makes them highly attractive to study dynamic aspects of Aβ-mediated retinopathy. Furthermore, we discuss our findings revealing how Aβ behaves at single-cell resolution, and consider the long-term implications for neuroretinal function. We propose Aβ as a key element in switching to a diseased retinal phenotype, which is now being used as a biomarker for latestage AMD.

Recurrence in node-negative advanced gastric cancer:Novel findings from an in-depth pathological analysis of prognostic factors from a multicentric series

AIM To analyze the clinicopathological characteristics of patients with both node-negative gastric carcinoma and diagnosis of recurrence during follow-up. METHODS We enrolled 41 patients treated with curative gastrectomy for p T2-4 a N0 gastric carcinoma between 1992 and 2010,who developed recurrence(Group 1). We retrospectively selected this group from the prospectively collected database of 4 centers belonging to the Italian Research Group for Gastric Cancer,and compared them with 437 p T2-4 a N0 patients without recurrence(Group 2). We analyzed lymphatic embolization,microvascular infiltration,perineural infiltration,and immunohistochemical determination of p53,Ki67,and HER2 in Group 1 and in a subgroup of Group 2(Group 2 bis) of 41 cases matched with Group 1 according to demographic and pathological characteristics. RESULTS T4 a stage and diffuse histotype were associated with recurrence in the group of p N0 patients. In-depth pathological analysis of two homogenous groups of p N0 patients,with and without recurrence during longterm follow-up(groups 1 and 2 bis),revealed two striking patterns: lymphatic embolization and perineural infiltration(two parameters that pathologists can easily report),and p53 and Ki67,represent significant factors for recurrence.CONCLUSION The reported pathological features should be considered predictive factors for recurrence and could be useful to stratify node-negative gastric cancer patients for adjuvant treatment and tailored follow-up.

Hepatic metastases from gastric cancer:A surgical perspective

Management of patients with hepatic metastases as the sole metastatic site at diagnosis of gastric cancer(synchronous setting) or detected during follow-up(metachronous) is controversial. The prevailing attitude in these cases is passive, leading to surgical palliation and, possibly, to chemotherapy. Authors focused this editorial in order to promote a more pragmatic attitude. They stress the importance of recognizing the good candidates to curative surgery of both gastric cancer and hepatic metastases(synchronous setting) or hepatic disease alone(metachronous disease) from those who will not benefit from surgical therapy. In fact, in adequately selected subgroup of patients surgery, especially if integrated in multimodal therapeutic strategies, may achieve unexpected 5-year survival rates, ranging from 10% to 40%. The critical revision of the literature suggests that some simple clinical criteria exist that may be effectively employed in patients selection. These are mainly related to the gastric cancer(factors T, N, G) and to the extent of hepatic involvement(factor H). Upon these criteria it is possible to adequately select about 50% of cases. In the remaining 50% of cases a critical discussion on a case-by-case basis is recommended, considering that among these patients some potential long-survivors exist, that survival is strictly influenced by the ablation of the tumor bulk and by multimodality treatments including chemotherapy and that in expert institutions this kind of surgery is performed with very low mortality and morbidity rates.

Microbial dysbiosis in spouses of ulcerative colitis patients: any clues to disease pathogenesis?

A number of alterations have been found within the gutmicrobial profile of patients with inflammatory bowel diseases when compared with the healthy population; however, it is unclear whether such dysbiosis is the cause or simply the consequence of the disease state. In ulcerative colitis, the environment seems to play a crucial role in disease etiology since monozygotic twins show a concordance rate of only 8%-10%-though it is unclear whether it does so by acting through the microbiome. In this study, the authors investigated the influence of cohabitation on the gut microbial community in healthy partners of ulcerative colitis patients-with the intent of clarifying some of these issues. As expected, ulcerative colitis patients had a significant dysbiosis and alterations in microbial metabolism. Interestingly, these abnormal fecal microbial communities were relatively similar amongst patients and their spouses. Thus, this study shows that the microbial profile might be partially transferred from ulcerative colitis patients to healthy individuals. Whether this finding impacts on disease development or has any implication for the role of the microbiome in inflammatory bowel disease etiology remains to be determined.

Platelet preparations in dentistry:How? Why? Where? When?

The aim of this article is to review the outcomes of platelet preparations in dentistry. A structured electronic search discovered 348 articles, which described the use of autologous platelet concentrates with a relevance to clinical dentistry. Among these articles, 220 articles investigated platelet rich plasma, 99 investigated platelet rich fibrin, 22 investigated plasma rich in growth factors and 7 investigated the use of concentrated growth factors. Several studies reported beneficial treament outcomes in terms of enhanced bone and soft tissue regeneration.

Long term follow-up of a family with GUCY2D dominant cone dystrophy

AIM: To describe long term follow-up in a family with GUCY2D dominant cone dystrophy. METHODS: Optical coherence tomography scans and fundus autofluorescence images were obtained. Flash and pattern electroretinograms(ERGs) and occipital pattern reversal visual evoked potentials were recorded. RESULTS: Two members of the same family(father and son) were identified to have the heterozygous R838 C mutation in the GUCY2D gene. The father presented at the age of 45 with bilateral bull’s eye maculopathy and temporal disc pallor. Over 13 y of serial follow up visits, the bull’s eye maculopathy progressed gradually into macular atrophy. Electrophysiological tests were significantly degraded suggesting poor macular function. Spectraldomain optical coherence tomography(SD-OCT) scans showed progressive loss and disruption of the ellipsoid layer at the foveal level. His son presented at the age of 16 with bilateral granular retinal pigment epithelial changes in both maculae. Electrophysiological testing was initially borderline normal but has gradually deteriorated to show reduced cone ERGs and macula function. SD-OCT demonstrated gradual macular thinning and atrophy bilaterally. Unlike his father, there was no disruption of the ellipsoid layer.CONCLUSION: Both family members exhibited gradual changes in their fundi, electrophysiological testing and multimodal imaging. Changes were milder than those observed in other mutations of the same gene.

Identification of host miRNAs that may limit human rhinovirus replication

AIM: To test whether the replication of human rhinovirus(HRV) is regulated by micro RNAs in human bronchial epithelial cells.METHODS: For the present study, the human cell line BEAS-2B(derived from normal human bronchial epithelial cells) was adopted. DICER knock-down, by si RNA transfection in BEAS-2B cells, was performed in order to inhibit micro RNA maturation globally. Alternatively, antisense oligonucleotides(anti-mi Rs) were transfectedto inhibit the activity of specific micro RNAs. Cells were infected with HRV-1B. Viral replication was assessed by measuring the genomic viral RNA by reverse transcription quantitative polymerase chain reaction(RT-q PCR). Association between micro RNA-induced-silencing-complex and viral RNA was detected by Ago2 co-immunoprecipitation followed by RT-q PCR. Targetscan v.6 was used to predict micro RNA target sites on several HRV strains.RESULTS: Here, we show that micro RNAs affect replication of HRV-1B. DICER knock-down significantly reduced the expression of mature micro RNAs in a bronchial epithelial cell line(BEAS-2B) and in turn, increased the synthesis of HRV-1B RNA. Additionally, HRV-1B RNA co-immunoprecipitated with argonaute 2 protein, an important effector for micro RNA activity suggesting that micro RNAs bind to viral RNA during infection. In order to identify specific micro RNAs involved in this interaction, we employed bioinformatics analysis, and selected a group of micro RNAs that have been reported to be under-expressed in asthmatic bronchial epithelial cells and were predicted to target different strains of rhinoviruses(HRV-1B,-16,-14,-27). Our results suggest that, out of this group of micro RNAs, mi R-128 and mi R-155 contribute to the innate defense against HRV-1B: transfection of specific anti-mi Rs increased viral replication, as anticipated in-silico.CONCLUSION: Taken together, our results suggest that pathological changes in micro RNA expression, as already reported for asthma or chronic obstructive pulmonary disease have the potential to affect Rhinovirus replication and therefore may play a role in virusinduced exacerbations.

Fecal lactoferrin accurately reflects mucosal inflammation in inflammatory bowel disease

BACKGROUND Studies have demonstrated a potential role for fecal biomarkers such as fecal calprotectin(FC)and fecal lactoferrin(FL)in monitoring inflammatory bowel diseases(IBD)-Crohn's disease(CD)and ulcerative colitis(UC).However,their correlation to endoscopic scores,disease severity and affected intestinal surface has not been extensively investigated.AIM To correlate FL,and for comparison white blood cell(WBC)and C-reactive protein(CRP),with endoscopic scores,disease extent and location in CD and UC.METHODS Retrospective analysis in 188 patients who had FL,CRP and WBC determined within 30 d of endoscopy.Disease location,disease extent(number of intestinal segments involved),disease severity(determined by endoscopic scores),timing of FL testing in relation to colonoscopy,as well as the use of effective fast acting medications(steroids and biologics)between colonoscopy and FL measurement,were recorded.RESULTS In 131 CD and 57 UC patients,both CRP and FL-but not WBC-distinguished disease severity(inactive,mild,moderate,severe).In patients receiving fastacting(steroids or biologics)treatment in between FL and colonoscopy,FL showed a higher correlation to endoscopic scores when tested before vs after the procedure(r=0.596,P<0.001,vs r=0.285,P=0.15 for the Simple Endoscopic Score for CD;and r=0.402,P=0.01 vs r=0.054 P=0.84 for Disease Activity Index).Finally,FL was significantly correlated with the diseased mucosal surface(colon-ileocolon>small bowel)and the number of inflamed colon segments.CONCLUSION FL and CRP separated disease severity categories with FL showing lower discriminating P-values.FL showed a close correlation with the involved mucosal surface and with disease extent and was more closely correlated to endoscopy when determined before the procedure–this indicating that inflammatory activity changes associated with therapy might be rapidly reflected by FL levels.FL can accurately and timely characterize intestinal inflammation in IBD.

Fulminant ulcerative colitis in a healthy pregnant woman

This case report concerns a 25-year-old patient with6-7 bloody stools/d, abdominal pain, tachycardia,and weight loss occurring during the third trimester of pregnancy. Severe ulcerative colitis complicated by toxic megacolon and gravidic sepsis was diagnosed by clinical evaluation, colonoscopy, and rectal biopsy that were performed safely without risk for the mother or baby. The patient underwent a cesarean section at28+6 wk gestation. The baby was transferred to the neonatal intensive care unit of our hospital and survived without complications. Fulminant colitis was managed conservatively by combined colonoscopic decompression and medical treatment. Although current European guidelines describe toxic megacolon as an indication for emergency surgery for both pregnant and non-pregnant women, thanks to careful monitoring, endoscopic decompression, and intensive medical therapy with nutritional support, we prevented the woman from having to undergo emergency pancolectomy. Our report seems to suggest that conservative management may be a helpful tool in preventing pancolectomy if the patient's condition improves quickly. Otherwise, surgery is mandatory.

Addicts with chronic hepatitis C:Difficult to reach,manage or treat?

AIM:To assess the acceptance,safety and efficacy of care and treatment for chronic hepatitis C(CHC)in drug addicts.METHODS:We designed a multidisciplinary,phase IV prospective cohort study.All illicit drug users(IDUs)visited a Territorial Addiction Service(SerT)in the District of Brescia,and hepatitis C antibody(HCVAb)testing positive were offered as part of a standardised hepatologic visit in our Gastroenterology Unit.Patients with confirmed CHC and without medical contraindications were administered peginterferon alfa-2b 1.5μg/kg per week plus ribavirin(800-1400 mg/d)for 16-48wk.All IDUs were unselected because of ongoing addiction and read and signed an informed consent form.Virologic responses at weeks 4 and 12 of therapy,at the end of treatment and 24 wk after the end of treatment were the main measures of efficacy.Adherence was estimated according to the 80/80/80 criteria.RESULTS:From November 2007 to December 2009,162 HCVAb+IDUs were identified.Sixty-seven patients(41%of the initial cohort)completed the diagnostic procedure,and CHC was diagnosed in 54(33%of the total).Forty-nine patients were offered therapy,and 39agreed(80%of acceptance rate).The prevalent HCV genotype was type 1,and the HCV RNA baseline level was over 5.6 log/mL in 61%of cases.Five patients dropped out,two because of severe adverse events(SAEs)and three without medical need.Twenty-three and 14 patients achieved end of treatment responses(ETRs;59%)and sustained virologic responses(SVRs;36%),respectively.Thirty-one patients were fully compliant with the study protocol(80%adherence).The prevalence of host and viral characteristics negatively affecting the treatment response was high:age over40 years(54%),male gender(85%),overweight body type(36%),previous unsuccessful antiviral therapy(21%),HCV genotype and viral load(60%and 62%,respectively),earlier contact with HBV(40%)and steatosis and fibrosis(44%and 17%,respectively).In a univariate analysis,alcohol intake was associated with a non-response(P=0.0018,95%CI:0.0058-0.4565).CONCLUSION:Drug addicts with CHC can be successfully treated in a multidisciplinary setting using standard antiviral combination therapy,despite several"difficult to reach,manage and treat"characteristics.

Challenges in studying geographic atrophy(GA) age-related macular degeneration: the potential of a new mouse model with GA-like features

Loss of central vision critical to everyday activities such as reading,face-recognition and driving due to damage in the central retina (the macula) is the leading cause of irreversible blindness amongst adults in the developed world.This condition,termed age-related macular degeneration (AMD),is a complex,chronic degenerative disease driven by a combination of genetic and lifestyle risk factors.Early signs of retinal changes in people as young as 30–40 years have been reported,although these individuals appear to be asymptomatic.However,by the age of 65,the disease is present in ~3% of individuals,which increases dramatically to affect 1/3 of individuals by the eighth decade of life.Early to intermediate AMD is estimated to affect ~150 million individuals globally,with another 10 million individuals suffering from end-stage,sight-threatening forms.These terminal stages are broadly grouped into dry (geographic atrophy,GA) or wet (choroidal neovascular,CNV) AMD (Sarks et al.,1988;Bird et al.,2014),with similar frequencies reported in patients.Recent advances in identifying genetic risk factors,including our discoveries in this field,indicate an initial shared pathology before progressing to aforementioned late-stage phenotypes.Currently,GA patients have no effective treatment,which may in part be due to the lack of good in vivo models for GA studies.Here,we summarize our new findings that describe an altogether new mouse model with GA-like features which shows progressive outer retinal pathology (Ibbett et al.,2019) that can be used to gain novel insights into GA and potentially as a tool for drug development.

Serial block face scanning electron microscopy reveals novel organizational details of the retinal pigment epithelium

Advances in imaging have led to the development of several new types of microscopes such as serial block face scanning electron microscopy (SBF-SEM),lightsheet microscopy,as well as X-ray micro-computed tomography (micro-CT),which enables the study of samples in fundamentally different ways.

Endoscopic management of sigmoid volvulus in children

Sigmoid volvulus(SV)is extremely uncommon in children and is usually associated with a long-standing history of constipation or pseudo-obstruction.An early diagnosis and management are crucial in order to prevent the appearance of hemorrhagic infarction of the twisted loop,avoiding further complications such as necrosis,perforation and sepsis.In patients with no evidence of peritonitis or ischemic bowel,treatment starts with resuscitation and detorsion of the SV,accomplished by means of sigmoidoscopy and concomitant rectal tube placement.The bowel is then prepared and surgery is undertaken electively during the same hospitalization.We report a detailed review of the literature focusing on technical details,risks and benefits of endoscopic management of SV in childhood.