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Chen Beard posted an update 6 months ago
Demodex folliculorum and brevis are commensal mites that live in low densities in human pilosebaceous follicles as part of the normal adult microbiota, but that give rise to demodicosis and, possibly, rosacea, when they proliferate excessively. This proliferation is favored by various factors, including age, marked immunosuppression, sebaceous gland hyperplasia, and hypervascularization-related factors. To study possible factors influencing mite proliferation, we explored the effects of different variables on Demodex densities (Dd) in a retrospective study of two groups of subjects selected on the basis of their clinical diagnosis Demodex+, consisting of subjects with demodicosis or with centro-facial papulopustules suggesting rosacea (n = 844, mean Dd 263.5 ± 8.9 D/cm2 ), and Demodex-, consisting of subjects with other facial dermatoses or healthy facial skin (n = 200, mean Dd 2.3 ± 0.4 D/cm2 ). Demodex densities were measured using two consecutive standardized skin surface biopsies (SSSB1 and round.
Women are more vulnerable to Alzheimer’s disease (AD) than men. We investigated (i) whether and at what age the AD hallmarks, that is, β-amyloid (Aβ) and hyperphosphorylated Tau (p-Tau) show sex differences; and (ii) whether such sex differences may occur in cognitively intact elderly individuals.
We first analysed the entire post-mortem brain collection of all non-demented ‘controls’ and AD donors from our Brain Bank (245 men and 403 women), for the presence of sex differences in AD hallmarks. Second, we quantitatively studied possible sex differences in Aβ, Aβ42 and p-Tau in the entorhinal cortex of well-matched female (n=31) and male (n=21) clinically cognitively intact elderly individuals.
Women had significantly higher Braak stages for tangles and amyloid scores than men, after 80years. In the cognitively intact elderly, women showed higher levels of p-Tau, but not Aβ or Aβ42, in the entorhinal cortex than men, and a significant interaction of sex with age was found only for p-Tau but not Aβ or Aβ42.
Enhanced p-Tau in the entorhinal cortex may play a major role in the vulnerability to AD in women.
Enhanced p-Tau in the entorhinal cortex may play a major role in the vulnerability to AD in women.Meniscus allograft transplantations (MATs) represent established surgical procedures with proven outcomes. Yet, storage as frozen specimens and limited cellular repopulation may impair graft viability. This proof-of-concept study tests the feasibility of injecting allogeneic mesenchymal stromal/stem cells (MSCs) in meniscus allograft tissue. We investigated the injectable cell quantity, survival rate, migration, and proliferation ability of MSCs up to 28 days of incubation. In this controlled laboratory study, seven fresh-frozen human allografts were injected with human allogeneic MSCs. Cells were labeled and histological characteristics were microscopically imaged up to 28 days. Mock-injected menisci were included as negative controls in each experiment. Selleck Box5 Toluidine blue staining demonstrated that a 100-µl volume can be injected while retracting and rotating the inserted needle. Immediately after injection, labeled MSCs were distributed throughout the injection channel and eventually migrated into the surrounding tissues. Histological assessment revealed that MSCs cluster in disc-like shapes, parallel to the intrinsic lamination of the meniscus and around the vascular network. Quantification showed that more than 60% of cells were present in horizontally injected grafts and more than 30% were observed in vertically injected samples. On Day 14, cells adopted a spindle-shaped morphology and exhibited proliferative and migratory behaviors. On Day 28, live/dead ratio assessment revealed an approximately 80% cell survival. The study demonstrated the feasibility of injecting doses of MSCs (>0.1 million) in meniscus allograft tissue with active cell proliferation, migration, and robust cell survival.
To assess the burden of transactive response DNA-binding protein of 43kDa (TDP-43) inclusions in a unique cohort of old-age patients with genetic frontotemporal lobar degeneration (gFTLD-TDP) and compare these patients with sporadic old-age individuals with TDP-43, either in the presence of Alzheimer’s disease (AD-TDP) or in isolation (pure-TDP).
The brain bank at Mayo Clinic-Jacksonville was searched for cases ≥75years old at death with TDP-43 extending into middle frontal cortex. Cases were split into the following groups (1) gFTLD-TDP (n=15) with progranulin (GRN)/C9ORF72 mutations; (2) AD-TDP (n=10)-cases with median Braak neurofibrillary tangle (NFT) stage VI, Thal phase V; (3) pure-TDP (n=10)-cases with median Braak NFT stage I, Thal phase I. Clinical data were abstracted; TDP-43 burden was calculated using digital pathology.
Amnestic Alzheimer’s dementia was the clinical diagnosis in ≥50% patients in each group. The distribution of TDP-43 burden in gFTLD-TDP and AD-TDP, but not pure-TDP, was limbic-predominant targeting CA1 and subiculum. Patients with gFTLD-TDP had higher burden in entorhinal cortex compared to AD-TDP. TDP-43 burden in middle frontal cortex did not differ between the three groups.
In old age it is challenging to clinically and pathologically differentiate gFTLD-TDP from AD-TDP and pure-TDP-43 based on burden. Like AD-TDP, old age gFTLD-TDP have a limbic predominant TDP-43 distribution. The finding that amnestic Alzheimer’s dementia was the most common clinical diagnosis regardless of group suggests that TDP-43 directly and indirectly targets limbic regions.
In old age it is challenging to clinically and pathologically differentiate gFTLD-TDP from AD-TDP and pure-TDP-43 based on burden. Like AD-TDP, old age gFTLD-TDP have a limbic predominant TDP-43 distribution. The finding that amnestic Alzheimer’s dementia was the most common clinical diagnosis regardless of group suggests that TDP-43 directly and indirectly targets limbic regions.CRISPR (clustered regularly interspaced short palindromic repeat)-based genetic screens offer unbiased and powerful tools for systematic and specific evaluation of phenotypes associated with specific target genes. CRISPR screens have been utilized heavily in vitro to identify functional coding and noncoding genes in a large number of cell types, including glioblastoma (GB), though no prior study has described the evaluation of CRISPR screening in GB in vivo. Here, we describe a protocol for targeting and transcriptionally repressing GB-specific long noncoding RNAs (lncRNAs) by CRISPR interference (CRISPRi) system in vivo, with tumor growth in the mouse cerebral cortex. Given the target-specific parameters of each individual screen, we list general steps involved in transducing guide RNA libraries into GB tumor lines, maintaining sufficient coverage, as well as cortically injecting and subsequently isolating transduced screen tumor cell populations for analysis. Finally, in order to demonstrate the use of this technique to discern an essential lncRNA, HOTAIR, from a nonessential lncRNA, we injected a 11 (HOTAIRcontrol nonessential lncRNA knockdown) mixture of fluorescently tagged U87 GB cells into the cortex of eight mice, evaluating selective depletion of HOTAIR-tagged cells at 2 weeks of growth.