Dual effect of methylprednsolone pulses on apoptosis of peripheral leukocytes in patients with renal diseases

Methylprednisolone pulse therapy: An alternative management of severe COVID-19

We present two cases of severe COVID-19 that were rejected by medical institutions. The management of the disease was done at home with methylprednisolone (MP) pulse therapy for three days. This resulted in a favorable evolution and resolution of most symptoms. COVID-19 infection presents as asymptomatic disease, non-severe symptomatic disease, and severe respiratory inflammatory disease. The first two forms are dependent on viral response and a “cytokine storm” is responsible for the progression into severe disease. Glucocorticoids (GC) reduce inflammation by different mechanism depending of their concentration. Pulses lead to overall apoptosis of immune cells. Studies using pulse MP as treatment for SARS-CoV-1 showed clinical improvement and decreased incidence of ARDS compared with patients who received low dose steroid treatment. Inhibition of excessive inflammation through timely administration of GC in the early stage of inflammatory cytokine storm effectively prevents the occurrence of ARDS.

Involvement of NK Cells against Tumors and Parasites

Host resistance against pathogens depends on a complex interplay of innate and adaptive immune mechanisms. Acting as an early line of defence, the immune system includes activation of neutrophils, tissue macrophages, monocytes, dendritic cells, eosinophils and natural killer (NK) cells. NK cells are lymphoid cells that can be activated without previous stimulation and are therefore like macrophages in the first line of defence against tumor cells and a diverse range of pathogens. NK cells mediate significant activity and produce high levels of proinflammatory cytokines in response to infection. Their cytotoxicity production is induced principally by monocyte-, macrophage- and dendritic cell-derived cytokines, but their activation is also believed to be cytokine-mediated. Recognition of infection by NK cells is accomplished by numerous activating and inhibitory receptors on the NK cells’ surface that selectively trigger the cytolytic activity in a major histocompability complex-independent manner. NK cells have trypanocidal activity of fibroblast cells and mediate direct destruction of extracellular epimastigote and trypomastigote forms of T. cruzi and T. lewisi in vitro; moreover, they kill plasmodia-infected erythrocytes directly through cell-cell interaction. This review provides a more detailed analysis of how NK cells recognize and respond to parasites and how they mediate cytotoxicity against tumor cells. Also the unique role of NK cells in innate immunity to infection and the relationship between parasites and carcinogenesis are discussed.

In vitro stem cell cultures from human dental pulp and periodontal ligament: new prospects in dentistry

In spite of the vast knowledge of tooth development and of the various kinds of specialized bone/tooth-associated cells, the characteristics and properties of their precursor cell populations present in the postnatal organism are little known, as is their possible therapeutic use. Taken together dental pulp stem cells (DPSCs) and periodontal ligament stem cells (PDLSCs) possess stem-cell-like qualities, including self-renewal capability and multi-lineage differentiation. Regenerative medicine is based on stem cells, signals and scaffolds. Transplantation of those cells, which can be obtained from an easily accessible tissue resource and expanded in vitro, holds promise as a therapeutic approach for reconstruction of tissues and bone in vivo.