Insights Into Human Norovirus Cultivation in Human Intestinal Enteroids

Human noroviruses (HuNoVs) are a significant cause of epidemic and sporadic acute gastroenteritis worldwide. The lack of a reproducible culture system hindered the study of HuNoV replication and pathogenesis for almost a half-century. This barrier was overcome with our successful cultivation of multiple HuNoV strains in human intestinal enteroids (HIEs), which has significantly advanced HuNoV research. We optimized culture media conditions and generated genetically modified HIE cultures to enhance HuNoV replication in HIEs. Building upon these achievements, we now present new insights into this culture system, which involve testing different media, unique HIE lines, and additional virus strains. HuNoV infectivity was evaluated and compared in new HIE models, including HIEs generated from different intestinal segments of individual adult organ donors, HIEs from human intestinal organoids produced from directed differentiation of human embryonic stem cells that were then transplanted and matured in mice before making enteroids (H9tHIEs), genetically engineered (J4FUT2 knock-in [KI], J2STAT1 knockout [KO]) HIEs, as well as HIEs derived from a patient with common variable immunodeficiency (CVID) and from infants. Our findings reveal that small intestinal HIEs, but not colonoids, from adults, H9tHIEs, HIEs from a CVID patient, and HIEs from infants support HuNoV replication with segment and strain-specific differences in viral infection. J4FUT2-KI HIEs exhibit the highest susceptibility to HuNoV infection, allowing the cultivation of a broader range of genogroup I and II HuNoV strains than previously reported. Overall, these results contribute to a deeper understanding of HuNoVs and highlight the transformative potential of HIE cultures in HuNoV research. IMPORTANCE Human noroviruses (HuNoVs) cause global diarrheal illness and chronic infections in immunocompromised patients. This paper reports approaches for cultivating HuNoVs in secretor positive human intestinal enteroids (HIEs). HuNoV infectivity was compared in new HIE models, including ones from (i) different intestinal segments of single donors, (ii) human embryonic stem cell-derived organoids transplanted into mice, (iii) genetically modified lines, and (iv) a patient with common variable immunodeficiency disease. HIEs from small intestine, but not colon, support HuNoV replication with donor, segment, and strain-specific variations. Unexpectedly, HIEs from one donor are resistant to GII.3 infection. The genetically modified J4FUT2 knock-in (KI) HIEs enable cultivation of a broad range of GI and GII genotypes. New insights into strain-specific differences in HuNoV replication in HIEs support this platform for advancing understanding of HuNoV biology and developing potential therapeutics

Social Issues in Charles Dickens' Great Expectations

Charles Dickens' novels mirror his age. His purpose was to focus attention on the various evils of his time. Dickens has described in his novels the bitter issues of life, especially those of children. He has attacked the prevailing evils of his day as a satirist. He has thrown light on the dark haunts of vice, crime and suffering. He has lime lighted the poor state of education, the miserable condition of jails, injustice, bureaucracy, nepotism, laissez faire, acquisitive worldliness and many others evils. He is specially the novelist of the London life, and has described the disparity of life- the life of the slums and the life of the wealthy persons in whom the wealth of the nation is concentrated

Fibrin clot adhesion to root surface treated with tetracycline hydrochloride and ethylenediaminetetraacetic acid: A scanning electron microscopic study

Background: Connective tissue attachment following periodontal regenerative surgery is directly related to the attachment of fibrin clot on to the root surface during early wound healing events.The adhesion of fibrin clot to the root surface affected by periodontal disease depends on the biologic acceptance of the root surface which can be accomplished by various root conditioning procedures during periodontal therapy. The present in vitro study has been designed to evaluate and compare the degree of fibrin clot adhesion to root surfaces treated with root conditioning agents tetracycline hydrochloride and ethylenediaminetetraacetic acid (EDTA). Materials and Methods: A total of 30 dentin blocks are divided into three groups and treated with tetracycline hydrochloride, EDTA and phosphate buffered saline and a drop of blood is added to each dentin block. The dentin blocks are then prepared for scanning electron microscopic analysis and examined for the degree of fibrin network frmation and entrapped erythrocytes. Results: The degree of fibrin clot adhesion was highest with tetracycline hydrochloride group, then with control group and least with EDTA treated group. Conclusion: According to the results of the present study, root conditioning with tetracycline hydrochloride produces a biologically acceptable root surface with enhanced fibrin clot adhesion, which is a critical step in early wound healing process. EDTA gel appears less effective in producing a root surface necessary for the adhesion of fibrin clot. The control without any root conditioning procedure showed poor fibrin clot adhesion when compared to tetracycline treated group, but when compared to EDTA treated group the fibrin clot adhesion was slightly better

Expression of activated transcription factor nuclear factor-κB in periodontally diseased tissues

Background: Chronic periodontitis is an inflammatory disease found mainly in adults. Little is known about molecular level changes associated with host response in this condition. Nuclear factor-κB (NF-κB) is a transcription factor implicated in immune and inflammatory responses. NF-κB activation has also been reported to be associated with many chronic inflammatory diseases. The purpose of this paper was to compare the nuclear and cytoplasmic expression of NF-κB transcription factor (p50/p65) and cytoplasmic expression of IκB in periodontal tissues of periodontitis patients and controls. Methods: Twenty patients with chronic periodontitis and 20 healthy controls were included in the study. Gingival tissues taken during extraction were processed for immunohistochemical staining and evaluation. Results: Nuclear (activated) p50 was found in 90% of periodontal patient tissues compared to only 30% of healthy tissues. A more significant result was obtained with p65 (75% versus 5%). Intense cytoplasmic immunoreactivity was also observed in periodontitis tissues. IκB, the inhibitor of NF-κB, was expressed only in 5% of periodontally diseased tissues. Conclusion: Activation of NF-κB (p50/p65) is significant in periodontally diseased tissues, suggesting the potential of inhibitors of NF-κB in managing periodontitis

Breeding Alfalfa (Medicago sativa L.) Adapted to Subtropical Agroecosystems

Alfalfa is planted in more than 30 million hectares worldwide, but despite its popularity in temperate regions, it is not widely grown in subtropical agroecosystems. It is critical to improve alfalfa for such regions, considering current predictions of global warming and the increasing demands for animal-based products. In this study, we examined the diversity present in subtropical alfalfa germplasm and reported genetic parameters for forage production. An initial screening was performed from 2014 to 2016, evaluating 121 populations from different subtropical origins. Then, a breeding population was created by crossing selected plants, resulting in 145 full-sib and 36 half-sib families, which were planted in a row-column design with augmented representation of three controls (‘Bulldog805′, ‘FL99′ and ‘UF2015′). Dry matter yield (DMY), canopy height (AH), and percentage blooming (BLOOM) were measured across several harvests. Moderate narrow-sense heritability and high genetic correlations between consecutive harvests were estimated for all traits. The breeding line UF2015 produced higher DMY than FL99 and Bulldog805, and it could be a candidate cultivar release. Several families produced higher DMY than all checks, and they can be utilized to develop high yielding and adapted alfalfa cultivars for subtropical agroecosystems.</jats:p