The regulation of exosome function in the CNS: implications for neurodegeneration

Exosomes are nanovesicles that have been shown to regulate neuronal development and regeneration, and modulate synaptic function

Ovarian remnant syndrome after laparoscopic ovariectomy in a cat

The first case of accidental implantation of ovarian tissue at the port site after laparoscopic ovariectomy in a cat was described. A 2-year-old, spayed female, domestic cat showed recurrent behavioral oestrus signs (vocalization, increased playfulness, and lordosis) four months after laparoscopic ovariectomy. Abdominal ultrasound revealed bilateral endometrial hyperplasia and an inhomogeneous mass attached to the abdominal wall at the port site of previous laparoscopic ovariectomy. Ovarian remnant syndrome was supposed. Diagnostic laparoscopy confirmed the presence of a mass that was 2 cm in diameter and macroscopically similar to ovarian tissue. Laparoscopy was converted to laparotomy to remove the abnormal tissue and the uterus. Histopathological findings showed follicles of various maturation stages in the mass, and confirmed endometrial hyperplasia. Histology underscored that ovarian remnant tissue resumed function. No clinical signs consistent with ovarian remnant syndrome were reported six months after removal of the abnormal tissue. In conclusion, removal of the ovaries through the laparoscopic port site may cause fortuitous ovarian tissue implantation at the abdominal wall in the cat

Evaluation of the Iatrogenic Sciatic Nerve Injury following Double Pelvic Osteotomy Performed with Piezoelectric Cutting Tool in Dogs

(1) Background: The double pelvic osteotomy (DPO) is a prophylactic surgical procedure associated with 0.4% incidence of sciatic nerve injury. The piezoelectric cutting tool is a surgical device able to involve only mineralized tissue avoiding neurovascular tissue and other soft tissue. This study aimed to evaluate the sciatic nerve injury observed in dogs underwent iliac osteotomy performed using the piezoelectric cutting tool. (2) Methods: Dogs underwent DPO performed with piezoelectric cutting tool were included. Neurological assessment was performed 6 and 24 h after surgery and then repeated 12 days, 4 and 8 weeks after surgery. Temporary and or permanent sciatic nerve injury were recorded. (3) Results: 84 DPOs performed in fifty dogs were included. No temporary/permanent neurological disease associated with iatrogenic damage of the sciatic nerve were observed. (4) Conclusions: The iliac osteotomy performed with piezoelectric cutting tool was not associated to iatrogenic sciatic nerve injury

Cortical microstructural changes predict tau accumulation and episodic memory decline in older adults harboring amyloid

Non-invasive diffusion-weighted imaging (DWI) to assess brain microstructural changes via cortical mean diffusivity (cMD) has been shown to be cross-sectionally associated with tau in cognitively normal older adults, suggesting that it might be an early marker of neuronal injury. Here, we investigated how regional cortical microstructural changes measured by cMD are related to the longitudinal accumulation of regional tau as well as to episodic memory decline in cognitively normal individuals harboring amyloid pathology. 122 cognitively normal participants from the Harvard Aging Brain Study underwent DWI, T1w-MRI, amyloid and tau PET imaging, and Logical Memory Delayed Recall (LMDR) assessments. We assessed whether the interaction of baseline amyloid status and cMD (in entorhinal and inferior-temporal cortices) was associated with longitudinal regional tau accumulation and with longitudinal LMDR using separate linear mixed-effects models. We find a significant interaction effect of the amyloid status and baseline cMD in predicting longitudinal tau in the entorhinal cortex (p = 0.044) but not the inferior temporal lobe, such that greater baseline cMD values predicts the accumulation of entorhinal tau in amyloid-positive participants. Moreover, we find a significant interaction effect of the amyloid status and baseline cMD in the entorhinal cortex (but not inferior temporal cMD) in predicting longitudinal LMDR (p < 0.001), such that baseline entorhinal cMD predicts the episodic memory decline in amyloid-positive participants. The combination of amyloidosis and elevated cMD in the entorhinal cortex may help identify individuals at short-term risk of tau accumulation and Alzheimer's Disease-related episodic memory decline, suggesting utility in clinical trials

A role for heparan sulfate proteoglycans in Plasmodium falciparum sporozoite invasion of anopheline mosquito salivary glands

HS (heparan sulfate) has been shown to be an important mediator of Plasmodium sporozoite homing and invasion of the liver, but the role of this glycosaminoglycan in mosquito vector host–sporozoite interactions is unknown. We have biochemically characterized the function of AgOXT1 (Anopheles gambiae peptide-O-xylosyltransferase 1) and confirmed that AgOXT1 can modify peptides representing model HS and chondroitin sulfate proteoglycans in vitro. Moreover, we also demonstrated that the mosquito salivary gland basal lamina proteoglycans are modified by HS. We used RNA interference-mediated knockdown of HS biosynthesis in A. gambiae salivary glands to determine whether Plasmodium falciparum sporozoites that are released from mosquito midgut oocysts use salivary gland HS as a receptor for tissue invasion. Our results suggest that salivary gland basal lamina HS glycosaminoglycans only partially mediate midgut sporozoite invasion of this tissue, and that in the absence of HS, the presence of other surface co-receptors is sufficient to facilitate parasite entry

6-Sulphated Chondroitins Have a Positive Influence on Axonal Regeneration

Chondroitin sulphate proteoglycans (CSPGs) upregulated in the glial scar inhibit axon regeneration via their sulphated glycosaminoglycans (GAGs). Chondroitin 6-sulphotransferase-1 (C6ST-1) is upregulated after injury leading to an increase in 6-sulphated GAG. In this study, we ask if this increase in 6-sulphated GAG is responsible for the increased inhibition within the glial scar, or whether it represents a partial reversion to the permissive embryonic state dominated by 6-sulphated glycosaminoglycans (GAGs). Using C6ST-1 knockout mice (KO), we studied post-injury changes in chondroitin sulphotransferase (CSST) expression and the effect of chondroitin 6-sulphates on both central and peripheral axon regeneration. After CNS injury, wild-type animals (WT) showed an increase in mRNA for C6ST-1, C6ST-2 and C4ST-1, but KO did not upregulate any CSSTs. After PNS injury, while WT upregulated C6ST-1, KO showed an upregulation of C6ST-2. We examined regeneration of nigrostriatal axons, which demonstrate mild spontaneous axon regeneration in the WT. KO showed many fewer regenerating axons and more axonal retraction than WT. However, in the PNS, repair of the median and ulnar nerves led to similar and normal levels of axon regeneration in both WT and KO. Functional tests on plasticity after the repair also showed no evidence of enhanced plasticity in the KO. Our results suggest that the upregulation of 6-sulphated GAG after injury makes the extracellular matrix more permissive for axon regeneration, and that the balance of different CSs in the microenvironment around the lesion site is an important factor in determining the outcome of nervous system injury

Genetic variants and functional pathways associated with resilience to Alzheimer\u27s disease.

Approximately 30% of older adults exhibit the neuropathological features of Alzheimer\u27s disease without signs of cognitive impairment. Yet, little is known about the genetic factors that allow these potentially resilient individuals to remain cognitively unimpaired in the face of substantial neuropathology. We performed a large, genome-wide association study (GWAS) of two previously validated metrics of cognitive resilience quantified using a latent variable modelling approach and representing better-than-predicted cognitive performance for a given level of neuropathology. Data were harmonized across 5108 participants from a clinical trial of Alzheimer\u27s disease and three longitudinal cohort studies of cognitive ageing. All analyses were run across all participants and repeated restricting the sample to individuals with unimpaired cognition to identify variants at the earliest stages of disease. As expected, all resilience metrics were genetically correlated with cognitive performance and education attainment traits (P-values \u3c 2.5 × 10-20), and we observed novel correlations with neuropsychiatric conditions (P-values \u3c 7.9 × 10-4). Notably, neither resilience metric was genetically correlated with clinical Alzheimer\u27s disease (P-values \u3e 0.42) nor associated with APOE (P-values \u3e 0.13). In single variant analyses, we observed a genome-wide significant locus among participants with unimpaired cognition on chromosome 18 upstream of ATP8B1 (index single nucleotide polymorphism rs2571244, minor allele frequency = 0.08, P = 2.3 × 10-8). The top variant at this locus (rs2571244) was significantly associated with methylation in prefrontal cortex tissue at multiple CpG sites, including one just upstream of ATPB81 (cg19596477; P = 2 × 10-13). Overall, this comprehensive genetic analysis of resilience implicates a putative role of vascular risk, metabolism, and mental health in protection from the cognitive consequences of neuropathology, while also providing evidence for a novel resilience gene along the bile acid metabolism pathway. Furthermore, the genetic architecture of resilience appears to be distinct from that of clinical Alzheimer\u27s disease, suggesting that a shift in focus to molecular contributors to resilience may identify novel pathways for therapeutic targets

Sex differences in the genetic architecture of cognitive resilience to Alzheimer\u27s disease.

Approximately 30% of elderly adults are cognitively unimpaired at time of death despite the presence of Alzheimer\u27s disease neuropathology at autopsy. Studying individuals who are resilient to the cognitive consequences of Alzheimer\u27s disease neuropathology may uncover novel therapeutic targets to treat Alzheimer\u27s disease. It is well established that there are sex differences in response to Alzheimer\u27s disease pathology, and growing evidence suggests that genetic factors may contribute to these differences. Taken together, we sought to elucidate sex-specific genetic drivers of resilience. We extended our recent large scale genomic analysis of resilience in which we harmonized cognitive data across four cohorts of cognitive ageing, in vivo amyloid PET across two cohorts, and autopsy measures of amyloid neuritic plaque burden across two cohorts. These data were leveraged to build robust, continuous resilience phenotypes. With these phenotypes, we performed sex-stratified [n (males) = 2093, n (females) = 2931] and sex-interaction [n (both sexes) = 5024] genome-wide association studies (GWAS), gene and pathway-based tests, and genetic correlation analyses to clarify the variants, genes and molecular pathways that relate to resilience in a sex-specific manner. Estimated among cognitively normal individuals of both sexes, resilience was 20-25% heritable, and when estimated in either sex among cognitively normal individuals, resilience was 15-44% heritable. In our GWAS, we identified a female-specific locus on chromosome 10 [rs827389, β (females) = 0.08, P (females) = 5.76 × 10-09, β (males) = -0.01, P(males) = 0.70, β (interaction) = 0.09, P (interaction) = 1.01 × 10-04] in which the minor allele was associated with higher resilience scores among females. This locus is located within chromatin loops that interact with promoters of genes involved in RNA processing, including GATA3. Finally, our genetic correlation analyses revealed shared genetic architecture between resilience phenotypes and other complex traits, including a female-specific association with frontotemporal dementia and male-specific associations with heart rate variability traits. We also observed opposing associations between sexes for multiple sclerosis, such that more resilient females had a lower genetic susceptibility to multiple sclerosis, and more resilient males had a higher genetic susceptibility to multiple sclerosis. Overall, we identified sex differences in the genetic architecture of resilience, identified a female-specific resilience locus and highlighted numerous sex-specific molecular pathways that may underly resilience to Alzheimer\u27s disease pathology. This study illustrates the need to conduct sex-aware genomic analyses to identify novel targets that are unidentified in sex-agnostic models. Our findings support the theory that the most successful treatment for an individual with Alzheimer\u27s disease may be personalized based on their biological sex and genetic context

Time course of risk factors associated with mortality of 1260 critically ill patients with COVID-19 admitted to 24 Italian intensive care units

94noopenPurpose: To evaluate the daily values and trends over time of relevant clinical, ventilatory and laboratory parameters during the intensive care unit (ICU) stay and their association with outcome in critically ill patients with coronavirus disease 19 (COVID-19). Methods: In this retrospective–prospective multicentric study, we enrolled COVID-19 patients admitted to Italian ICUs from February 22 to May 31, 2020. Clinical data were daily recorded. The time course of 18 clinical parameters was evaluated by a polynomial maximum likelihood multilevel linear regression model, while a full joint modeling was fit to study the association with ICU outcome. Results: 1260 consecutive critically ill patients with COVID-19 admitted in 24 ICUs were enrolled. 78% were male with a median age of 63 [55–69] years. At ICU admission, the median ratio of arterial oxygen partial pressure to fractional inspired oxygen (PaO2/FiO2) was 122 [89–175] mmHg. 79% of patients underwent invasive mechanical ventilation. The overall mortality was 34%. Both the daily values and trends of respiratory system compliance, PaO2/FiO2, driving pressure, arterial carbon dioxide partial pressure, creatinine, C-reactive protein, ferritin, neutrophil, neutrophil–lymphocyte ratio, and platelets were associated with survival, while for lactate, pH, bilirubin, lymphocyte, and urea only the daily values were associated with survival. The trends of PaO2/FiO2, respiratory system compliance, driving pressure, creatinine, ferritin, and C-reactive protein showed a higher association with survival compared to the daily values. Conclusion: Daily values or trends over time of parameters associated with acute organ dysfunction, acid–base derangement, coagulation impairment, or systemic inflammation were associated with patient survival.openZanella A.; Florio G.; Antonelli M.; Bellani G.; Berselli A.; Bove T.; Cabrini L.; Carlesso E.; Castelli G.P.; Cecconi M.; Citerio G.; Coloretti I.; Corti D.; Dalla Corte F.; De Robertis E.; Foti G.; Fumagalli R.; Girardis M.; Giudici R.; Guiotto L.; Langer T.; Mirabella L.; Pasero D.; Protti A.; Ranieri M.V.; Rona R.; Scudeller L.; Severgnini P.; Spadaro S.; Stocchetti N.; Vigano M.; Pesenti A.; Grasselli G.; Aspesi M.; Baccanelli F.; Bassi F.; Bet A.; Biagioni E.; Biondo A.; Bonenti C.; Bottino N.; Brazzi L.; Buquicchio I.; Busani S.; Calini A.; Calligaro P.; Cantatore L.P.; Carelli S.; Carsetti A.; Cavallini S.; Cimicchi G.; Coppadoro A.; Dall'Ara L.; Di Gravio V.; Erba M.; Evasi G.; Facchini A.; Fanelli V.; Feliciotti G.; Fusarini C.F.; Ferraro G.; Gagliardi G.; Garberi R.; Gay H.; Giacche L.; Grieco D.; Guzzardella A.; Longhini F.; Manzan A.; Maraggia D.; Milani A.; Mischi A.; Montalto C.; Mormina S.; Noseda V.; Paleari C.; Pedeferri M.; Pezzi A.; Pizzilli G.; Pozzi M.; Properzi P.; Rauseo M.; Russotto V.; Saccarelli L.; Servillo G.; Spano S.; Tagliabue P.; Tonetti T.; Tullo L.; Vetrugno L.; Vivona L.; Volta C.A.; Zambelli V.; Zanoni A.Zanella, A.; Florio, G.; Antonelli, M.; Bellani, G.; Berselli, A.; Bove, T.; Cabrini, L.; Carlesso, E.; Castelli, G. P.; Cecconi, M.; Citerio, G.; Coloretti, I.; Corti, D.; Dalla Corte, F.; De Robertis, E.; Foti, G.; Fumagalli, R.; Girardis, M.; Giudici, R.; Guiotto, L.; Langer, T.; Mirabella, L.; Pasero, D.; Protti, A.; Ranieri, M. V.; Rona, R.; Scudeller, L.; Severgnini, P.; Spadaro, S.; Stocchetti, N.; Vigano, M.; Pesenti, A.; Grasselli, G.; Aspesi, M.; Baccanelli, F.; Bassi, F.; Bet, A.; Biagioni, E.; Biondo, A.; Bonenti, C.; Bottino, N.; Brazzi, L.; Buquicchio, I.; Busani, S.; Calini, A.; Calligaro, P.; Cantatore, L. P.; Carelli, S.; Carsetti, A.; Cavallini, S.; Cimicchi, G.; Coppadoro, A.; Dall'Ara, L.; Di Gravio, V.; Erba, M.; Evasi, G.; Facchini, A.; Fanelli, V.; Feliciotti, G.; Fusarini, C. F.; Ferraro, G.; Gagliardi, G.; Garberi, R.; Gay, H.; Giacche, L.; Grieco, D.; Guzzardella, A.; Longhini, F.; Manzan, A.; Maraggia, D.; Milani, A.; Mischi, A.; Montalto, C.; Mormina, S.; Noseda, V.; Paleari, C.; Pedeferri, M.; Pezzi, A.; Pizzilli, G.; Pozzi, M.; Properzi, P.; Rauseo, M.; Russotto, V.; Saccarelli, L.; Servillo, G.; Spano, S.; Tagliabue, P.; Tonetti, T.; Tullo, L.; Vetrugno, L.; Vivona, L.; Volta, C. A.; Zambelli, V.; Zanoni, A