Factors Behind the Higher COVID-19 Risk in Diabetes: A Critical Review

Diabetes mellitus (DM) and coronavirus disease 2019 (COVID-19) are public health issues worldwide, and their comorbidities trigger the progress to severe disease and even death in such patients. Globally, DM has affected an estimated 9.3% adults, and as of April 18, 2021, the World Health Organization (WHO) has confirmed 141,727,940 COVID-19 confirmed cases. The virus is spread via droplets, aerosols, and direct touch with others. Numerous predictive factors have been linked to COVID-19 severity, including impaired immune response and increased inflammatory response, among others. Angiotensin receptor blockers and angiotensin converting enzyme 2 have also been identified as playing a boosting role in both susceptibility and severity to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Specifically, in DM patients, both their control and management during this pandemic is herculean as the restriction periods have markedly hampered the maintenance of means to control glycemia, hypertension, and neuroendocrine and kidney diseases. In addition, as a result of the underlyin cardio-metabolic and immunological disorders, DM patients are at a higher risk of developing the severe form of COVID-19 despite other comorbidities, such as hypertension, also potentially boosting the development of higher COVID-19 severity. However, even in non-DM patients, SARS-CoV-2 may also cause transient hyperglycemia through induction of insulin resistance and/or pancreatic ß-cell injury. Therefore, a strict glucose monitoring of DM patients with COVID-19 is mandatory to prevent life-threatening complications.NC-M acknowledges the Portuguese Foundation for Science and Technology under the Horizon 2020 Program (PTDC/PSI-GER/28076/2017)

Fertility disturbances of dimethylacetamide and glycerol in rooster sperm diluents Discrimination among effects produced pre and post freezing-thawing process

With avian sperm cryopreservation protocols, the most widely used cryoprotectants (CPAs) are the glycerol (GLY; in gradual freezing: in-straw freezing method), and the dimethylacetamide (DMA; in pellets by plunging into liquid nitrogen: in-pellet rapid freezing method). Use of both methods results in a small portion of thawed live sperm with lesser fertilizing ability compared with the semen samples immediately after collection. This study was conducted to assess the pre-freezing damage occurring to the sperm due to the interaction with the cryoprotectants (CPAs) GLY (8%) and DMA (5%), as well as the post-freezing damage resulting from both freezing methods Data for each treatment, in fresh and frozen-thawed samples, were compared for sperm motility, fertilizing capacity and sperm-egg penetration holes/germinal disc (SP holes/GD). Hens (n = 50) were artificially inseminated (10 hens/treatment) six times with 3 day intervals between inseminations. The treatment of fresh sperm with DMA led to a reduction (P < 0.05) in the count of SP holes/GD (21.4) and the fertility rate (66.7%). The addition and elimination of GLY in fresh samples resulted in a lesser (P < 0.05) number of SP holes/GD (11.8) and the fertility rate (i.e., 50.0%). The number of SP-holes/GD was least in frozen-thawed samples using both DMA and GLY (14.2 and 9.2, respectively). The fertility rate when using semen frozen with DMA in-pellets was greater (P < 0.05) than with use of semen that had been frozen using GLY in straws (46.4% compared with 31.3%). The reduction in fertility compared with the control when semen was cryopreserved using GLY was 64.1%; the GLY addition and elimination was responsible for two thirds of this reduction. The reduction in fertility when using semen cryo-preserved with DMA was 46.7%; half of the reduction was attributed to the treatment with DMA. In conclusion, the mechanical damage attributed to the process for reducing GLY concentrations was more harmful to sperm fertilizing capacity than the toxicity of DMA and freeze/thaw process. For both freezing methods, the amount of sperm cryo-damage was similar, when the damage attributed to the CPA addition and elimination process was excluded

Influence of Mushroom Polysaccharide, Nano-Copper, Copper Loaded Chitosan, and Lysozyme on Intestinal Barrier and Immunity of LPS-mediated Yellow-Feathered Chickens

This study investigated the influence of dietary supplementation with some antibiotic alternatives on growth performance, intestinal barrier, and immunity of lipopolysaccharide (LPS) challenged chicks. Wenshi females, aged 4 days, were allocated randomly into eight groups, each with six replicates of 20 birds (n = 120/treatment), which received a basal diet supplemented with 0 (control), 0 (LPS), 200 mg/kg aureomycin, 50 mg/kg mushroom polysaccharide, 100 mg/kg mushroom polysaccharide, 500 mg/kg nano-copper, 300 mg/kg copper loaded chitosan, and 500 mg/kg lysozyme for 21 days. On day 18 and 20, the control birds were injected with 0.5 mL saline solution, the other treatments were injected with 0.5 mL saline containing 500 &micro;g LPS/kg body weight (BW). The results indicated that LPS treatment reduced the BW, average daily gain (ADG), and daily feed intake (ADFI) than the controls (p &lt; 0.05), and the antibiotic and the tested alternatives could not retrieve the normal BW, ADG, and ADFI. The tested additives reduced several negative effects of LPS; they reduced diamine oxidase activity and inflammatory mediators in plasma, jejunal mucosa, spleen and thymus, increased content of immunoglobulin in plasma and jejunal mucosa, and decreased gene expression of inducible nitric oxide synthase and Cyclooxygenase 2 in jejunal mucosa

Optimization of Dietary Zinc Requirement for Broiler Breeder Hens of Chinese Yellow-Feathered Chicken

This study aimed to establish the optimal dietary zinc requirement of Chinese yellow-feathered Lingnan broiler breeders. A total of 576 breeder hens aged 58 weeks were randomly assigned to six treatments, each with 6 replicates of 16 birds (n = 96/treatment). The hens were fed either a basal diet (22.81 mg/kg Zn) or the same basal diet supplemented with additional 24, 48, 72, 96, and 120 mg Zn/kg up to 65 weeks of age. Compared to the results of birds fed the basal diet (22.81 mg Zn/kg), the dietary supplementation with additional Zn (mg/kg) showed higher egg laying rate (at 48&ndash;120 mg), EM (at 96 mg/kg), yolk Zn content (at 24&ndash;120 mg/kg), fertility (at 48&ndash;120 mg/kg), hatchability (at 48&ndash;96 mg/kg), tibial breaking strength (at 24&ndash;48 mg/kg), tibial ash content (at 48 mg/kg), serum CuZnSOD activity (at 72 mg/kg) and T-AOC (at 48 mg/kg), and ovarian CuZnSOD and GSH-Px activities (at 96&ndash;120 mg/kg), and lower FCR (at 96 mg/kg). The regression model showed that the optimal supplemental Zn for maximal egg laying rate, yolk Zn content, fertility, and hatchability of Chinese yellow-feathered broiler breeders aged 58 to 65 weeks were 71.09, 92.34, 94.44 and 98.65 mg/kg diet, respectively

Effect of the interaction between cryoprotectant concentration and cryopreservation method on frozen/thawed chicken sperm variables

This work examines the effect of the interaction between different concentrations of two cryoprotectants - glycerol (GLY) and dimethylacetamide (DMA) - and two methods of cryopreservation - pellets produced by plunging into liquid nitrogen and gradual in-straw freezing - on frozen/thawed chicken sperm variables. Sperm was cryopreserved using (i) 6% DMA, following the in-straw and the pellet methods (ii) 11% GLY, following the in-straw and the pellet methods; and (iii) 8% GLY in the in-straw method and 3% DMA in the pellet method (i.e. reduced cryoprotectant concentrations). When 6% DMA was used as the cryoprotectant, no differences were seen between the in-straw and pellet methods in terms of frozen/thawed sperm variables or fertility (10.8% and 12.8%, respectively). The viability and motility variables of the frozen/thawed sperm produced using the in-straw method with 11% GLY were higher (p < 0.05) than those recorded for the sperm preserved using the same cryoprotectant and concentration in the pellet method. However, fertility was extremely low in both groups (2.1% and 4.2% for the in-straw and pellet methods, respectively). Finally, the use of 8% GLY in the in-straw method returned higher sperm viability, intact acrosome and motility values than the use of 3% DMA in the pellet method (p < 0.01). No differences were seen, however, in the fertility results obtained (28.8% and 25.0%, respectively). These results suggest that cryoprotectant concentrations can be reduced and still provide acceptable fertility rates. © 2014 Blackwell Verlag GmbH

Sperm-egg penetration assay assessment of the contraceptive effects of glycerol and egg yolk in rooster sperm diluents

Glycerol (GLY) and egg yolk (EY) are good cryoprotectants of avian and mammalian sperm, but in birds, they strongly inhibit the eventual fertilization of ova. Using the sperm penetration (SP-holes) assay and fertility trials, the present study investigates (1) thepossible mechanism by which this contraceptive effect occurs in chickens and (2) the maximum concentrations of GLY and EY tolerated by fresh rooster sperm. Seventy Black-Barred Andaluza hens (five per treatment) were inseminated four times (twice per week) with 0.1mL of fresh semen from roosters of the same breed diluted 11 (vv) with Lake and Ravie medium containing different concentrations of GLY or EY. No adverse effects on acrosome integrity, sperm motility, or viability were seen with any concentration of GLY or EY. The number of SP-holes on perivitelline layer samples taken from abovethe germinal disc became progressively lower at GLY concentrations of 1.5% or greater (P>0.05). No holes caused by sperms were seen in unfertilized eggs. The corresponding fertility results showed similar reductions when the GLY concentration was 1.5%or greater. No changes in the number of SP-holes were seen with increasing EY concentrations (0%-7.5%), nor were any differences in fertility observed, except for a reduction when 15% EY was used. The results therefore reveal that GLY affects the transit of sperms through the oviduct in their attempt to reach the infundibulum area, limiting their access to the ovum perivitelline layer. Egg yolk had no such effect, nor did it influence acrosome reaction capacity; its mechanism of contraceptive action therefore remains unknown. The maximum GLY and EY concentrations tolerated by the rooster sperm were 0.75% and 7.5%, respectively. © 2015 Elsevier Inc

Successful use of artificial insemination in the production of red-legged partridges (Alectoris rufa)

This paper reports the first successful artificial insemination (AI) of red-legged partridges (Alectoris rufa), the fertility rate achieved, and the length of time sperm cells can survive inside the oviduct (i.e.;the post-AI fertile period). Semen from 20 mature males was collected by massage and pooled for use in single intravaginal inseminations (20 μL of fresh, undiluted semen) of eight females (15 × 106 sperm/female). The latter’s eggs were then collected for 4 weeks, and the fertilizing capacity of the sperm used in the preceding AIs was determined by observing the development of the blastoderm. The duration of the post-AI fertile period was determined by subjecting fertilized eggs to the SP-holes assay. A second experiment was then performed to measure the percentage of viable embryos at 20 days of incubation (30 %) and hatchability (40 %). The mean fertility rate was 34.5 ± 11.7 % and the SP-holes value 17.3 ± 4.3. The mean duration of the post-AI fertile period was 3 weeks. In conclusion, the present work reports the first ever birth of partridge chicks following AI and shows that this procedure may be of use in the conservation of this species. © 2015, Springer-Verlag Berlin Heidelberg