Innate Immune Response and Inflammasome Activation During SARS-CoV-2 Infection

Inflammation - The novel coronavirus SARS-CoV-2, responsible for the COVID-19 outbreak, has become a pandemic threatening millions of lives worldwide. Recently, several vaccine candidates and drugs...     

µ1‐Opioid receptors in the dorsomedial and ventrolateral columns of the periaqueductal grey matter are critical for the enhancement of post‐ictal antinociception

Generalised tonic and tonic–clonic seizures are followed by significant increase in nociceptive thresholds in both laboratory animals and humans. The endogenous opioid peptides play a role in antinociceptive signalling, and the periaqueductal grey matter (PAG) is recruited to induce analgesia. Thus, the aim of this investigation was to evaluate the role of µ₁‐opioid receptors in the dorsomedial (dm) and ventrolateral (vl) columns of PAG in post‐ictal antinociception. Pentylenetetrazole (PTZ; 64 mg/kg), which is an ionotropic GABA‐mediated Cl^? influx antagonist, was intraperitoneally (IP) administered to induce tonic–clonic seizures in Wistar rats. The tail‐flick test was used to measure the nociceptive threshold. Microinjections of naltrexone (5.0 µg/0.2 µL), which is a non‐selective opioid receptor antagonist, in both dmPAG and vlPAG decreased the tonic–clonic seizure‐induced antinociception in seizing animals from 10 to 120 min after seizures. Furthermore, microinjections of the µ₁‐opioid receptor‐selective antagonist naloxonazine (5.0 µg/0.2 µL) into the dmPAG decreased post‐ictal antinociception immediately after convulsive reactions and from 10 to 90 min after seizures. However, vlPAG‐pretreatment with naloxonazine at the same concentration decreased the post‐ictal antinociception 30 min after the onset of tonic–clonic seizures and the nociceptive threshold returned to basal values 120 min after seizures. These findings indicate that µ₁‐opioid receptor‐signalling mechanisms in both dmPAG and vlPAG play a relevant role in the organisation of post‐ictal antinociception. In addition, µ₁‐opioid receptors in the dmPAG rather than in vlPAG seem to be more critically recruited during the antinociception induced by generalised tonic–clonic seizures.     

Ameliorative effects of rutin against cisplatin-induced reproductive toxicity in male rats

Background

Cisplatin (CP) or cis-diammine dichloroplatinum (II) is a platinum based standard antineoplastic drug which is used against variety of solid tumors and neoplasms. The present study aimed to evaluate the shielding effects of rutin against CP induced testicular toxicity in rats.

Methods

28 male rats were divided into four groups. First group was given saline orally while second group received intra-peritoneal (i.p) injection of cisplatin (7 mg/kg) on day first and received saline for next 13 days. Third group received i.p injection of cisplatin at day one and treated with rutin (75 mg/kg) orally for next 13 days. Fourth group was treated with rutin orally for 13 days. Animals were sacrificed on 14th day and reproductive organs were analyzed for various parameters.

Results

Cisplatin treatment resulted in a significant decrease in daily sperm production, decrease in head length and % DNA in head, reduction of epithelial cell height, tubular diameter, reduction of the number of spermatogonia, spermatocytes and spermatids, increase in the thiobarbituric acid reactive substances (TBARS) and oxidative stress in testicular tissues, and change of the intra-testicular testosterone concentrations. Rutin co-treatment resulted in reversing cisplatin effect on DNA damage, sperm count, histological and biochemical parameters.

Conclusion

These results indicated that rutin co-treatment could ameliorate cisplatin-induced reproductive toxicity in male rats.

     

Pronounced susceptibility to infection by Salmonella enterica serovar Typhimurium in mice chronically exposed to lead correlates with a shift to Th2-type immune responses

Persistent exposure to inorganic lead (Pb) is known to adversely affect the immune system. In the present study, we assessed the effect of chronic Pb exposure on susceptibility to infection by the facultative intracellular pathogen Salmonella enterica serovar Typhimurium. Mice were exposed to 10 mM Pb-acetate in drinking water for approximately 16 weeks, resulting in a significant level of Pb in the blood (106.2+/-8.9 microg/dl). Pb exposure rendered mice susceptible to Salmonella infection, manifested by increased bacterial burden in target organs and heightened mortality. Flow cytometric analysis of the splenic cellular composition in normal and Pb-exposed mice revealed no gross alteration in the ratios of B and T lymphocytes or myeloid cells. Similarly, the capacity of B and T cells to upregulate the expression of activation antigens in response to mitogenic or inflammatory stimuli was not hindered by Pb exposure. Analysis of the ability of ex vivo-cultured splenocytes to secrete cytokines demonstrated a marked reduction in IFN-gamma and IL-12p40 production associated with Pb exposure. In contrast, secretion of IL-4 by splenocytes of Pb-treated mice was 3- to 3.6-fold higher than in normal mice. The increased capacity to produce IL-4 correlated with a shift in the in vivo anti-Salmonella antibody response from the protective IgG2a isotype to the Th2-induced IgG1 isotype. We conclude that chronic exposure to high levels of Pb results in a state of immunodeficiency which is not due to an overt cytotoxic or immunosuppressive mechanism, but rather is largely caused by a shift in immune responsiveness to Th2-type reactions.     

Multiple eccrine poromas arising in chronic radiation dermatitis

A 70-year-old white man developed 7 eccrine poromas in an area of chronic radiation dermatitis of his right lower extremity over a period of 37 years. To our knowledge, multiple eccrine poromas unequivocally linked to chronic X-ray damage are hitherto unreported.