Hepatoprotective effects of a chemically-characterized extract from artichoke (Cynara scolymus L.) against AFB1-induced toxicity in rats.

This study was conducted to investigate the protective potential of a pharmaceutically formulated capsule of artichoke leaf powder (ArLP) against aflatoxin B1 (AFB1)-induced hepatotoxicity in male albino rats. In the 42-day experiment, rats were divided into five equal groups: (i) control, treated with sterile water, (ii) treated with 4% DMSO as AFB1 vehicle, (iii) ArLP of 100 mg kg-1 bw, (iv) AFB1 of 72 µg kg-1 bw, and (v) AFB1 plus ArLP. Exposure of rats to AFB1 resulted in hepatotoxicity as manifested by the intensification of oxidative stress, production of free radicals and significant increase in the activity levels of liver function enzymes relative to the control. Significant reductions in both the enzymatic and non-enzymatic antioxidant markers as well as histopathological abnormalities in liver tissues were also observed. Notably, the combined administration of ArLP with AFB1 clearly reduced AFB1-mediated adverse effects leading to the normalization of most of these parameters back to control levels. These findings clearly highlight the potential benefits of artichoke dietary supplements as a safe and natural solution in counteracting the adverse hepatotoxic effects conferred by AFB1 exposure. Further research is warranted to fully dissect the biochemical and molecular mechanism of action of the observed artichoke-mediated hepatoprotection.

Factors affecting outcomes of embryo transfer in dromedary camels: A retrospective study.

The present study aimed to use a comprehensive approach for evaluating 12 factors related to embryo quality (shape, size and transparency), donors (age, ET type, number of recovered embryos and day of uterine flushing), recipients (age), males (age and individual variations) and environment (season and year) which could affect the outcome of ET in terms of pregnancy (PR) and pregnancy losses in dromedary camels. During three breeding seasons, 116 donor females were mated repeatedly at 12- to 14-day intervals by fertile male camels (n = 33) without stimulation of the ovaries (WSPO). Superovulation (SPO ET) regimen was applied for each donor female twice or thrice per season. In the occasions of applying superovulation regimen, donor females having an ovulatory follicle were mated instead of GnRH administration and superovulation regimen was applied 4 days post-mating (MIX ET). The uteri of all donor females were flushed at Day 8 or 9 post-mating, and a total of 2,095 embryos were recovered and transferred individually to 924 recipient females. Pregnancy diagnoses were conducted at Day 10 after ET (Days 18-19 of gestation) by using progesterone assay and by transrectal ultrasonography (TRU) at Days 30 and 60 of gestation. By using logistic regression analysis, transparency of embryos and age of recipient females had significant effects on PR at Days 18-19 (p < .01), 30 (p < .01) and 60 (p < .01; p < .05, respectively) of gestation. The shape of embryos had significant effects on the PR at Days 30 (p < .05) and 60 (p < .01) of gestation. Type of ET and the breeding season (year) had significant (p < .05) effects on the PR at Day 30, while day of flushing had the same effect on PR at Day 60. Regarding the pregnancy losses, transparency and shape of the embryo, type of ET, breeding season had significant (p < .05) effect on the late embryonic mortalities (LEM) and shape and season of year had significant (p < .01 and p < .05, respectively) effect on LEM/early foetal mortalities (EFM). Regarding male individual factor, there was a tendency for a significant (p = .055) effect of male camels on the PR at Days 18-19 and rate of LEM. In conclusion, transferring a spherical, transparent or a large-sized embryo (>750 µm) into recipient females ageing between 8 and 11 y could greatly improve the PR from Days 18 to 60 of gestation. Also, embryo recovered from donor females with Mix ET type or embryos sired by certain male camel or at Day 8 post-mating of the donor could improve the 2-month PR. In addition, transferring a transparent or spherical-shaped embryo or embryos recovered from donor females with SPO or Mix ET could reduce the pregnancy losses during the first 2 months of pregnancy.

Effect of the interval from GnRH administration after ovarian super-stimulation on the recovered oocytes, and effect of the transferred cloned blastocysts on the pregnancy rate and pregnancy loss in dromedary camel.

The present study was conducted to evaluate the number and maturity of the recovered oocytes after two intervals of in-vivo maturation. In addition to evaluating the effect of the developmental stage, as well as the number of cloned transferred blastocysts on the pregnancy rate and early pregnancy loss (EPL) in dromedary camel. The donor animals (n = 52) were super-stimulated using a single injection of 3000 IU of eCG followed by GnRH administration for oocyte maturation. Cumulus oocyte complexes (COCs) were collected by transvaginal ultrasound-guided aspiration (OPU) either 24-26 h or 18-20 h after GnRH administration. A fewer number of COCs with a lower percentage of oocyte maturity was observed at 24-26 h in comparison to 18-20 h. The effect of the cloned blastocysts' transferred number and developmental stage on the pregnancy rate and EPL was investigated. The total pregnancy rates at 10 days post-ET, 1 and 2 months were 21.9, 12.4, and 8.6%, respectively. Transfer of two or 3-4 embryos per surrogate was accompanied with a higher pregnancy rate at 1 and 2 months than a single embryo transfer. Rates of EPL were 43.5 and 60.1% at 1 and 2 months of pregnancy, respectively. The transfer of two embryos per surrogate was associated with a lower rate of EPL than ET of a single embryo at 1 and 2 months of pregnancy. Also, the ET of 3-4 embryos per surrogate showed a higher rate of EPL than the ET of two embryos at 2 months of pregnancy. ET of hatching (HG) blastocysts showed higher pregnancy rates and fewer EPL than ET of unhatched (UH) or fully hatched (HD) cloned blastocysts at 1 and 2 months of pregnancy. In conclusion, a high number of in-vivo matured oocytes can be recovered by ultrasound-guided transvaginal OPU from super-stimulated females using 3000 IU eCG and an interval of 18-20 h after GnRH administration. The transfer of two hatching cloned blastocytes per surrogate increases the pregnancy rate and decreases EPL in dromedary camels.

R0 of COVID-19 and its impact on vaccination coverage: compared with previous outbreaks.

Background: Vaccination has been known to reduce morbidity and mortality of infectious diseases since the emergence of the 1st vaccine in the 18th century. That's why global efforts are directed toward finding a vaccine for COVID-19 in order to eliminate its threat.The current pandemic of COVID-19 has changed the world affecting all fields significantly as a result of the preventive measures including locking down, social distancing, obligatory mask wearing, stopping flights, etc. The medical field is clearly the most significantly affected starting from altering most of the research efforts toward the new virus passing through the inadequate number of physicians as well as unavailable intensive care unit (ICU) beds. In order to break the restricted preventive measures, we need to minimize the newly infected cases which can be achieved by reaching adequate herd immunity. Moreover, calculating the basic reproduction number (R0) of COVID-19 is crucial to estimate the herd immunity threshold (Ic).Methods: In this review, we searched PubMed for studies that mentioned the R0 of COVID_19, SARS, and MERS as well as measles, Zika and dengue virus to calculate the herd immunity threshold and the minimal vaccination coverage.Results: The value of R0 could vary for the same disease and consequently the herd immunity threshold as well as the vaccination coverage. The R0 of COVID-19 ranged widely through various articles from 1.4 to 6.68. As a result, the herd immunity threshold would range from 28.57% to 85.03%. However, the vaccination coverage depends also on the effectiveness of the vaccine which is still unknown.Conclusion: The calculations of vaccination coverage include many variables such as the R0 of the disease, Ic that depends on that value as well as sensitivity and specificity of the vaccine itself.

Preservation of dromedary camel embryos at 4 °C for up to 5 days: Factors affecting the pregnancy and pregnancy loss rates.

The aims of the present study were to evaluate the effect of cooling of the dromedary camel embryos on the pregnancy and pregnancy loss rates, and to investigate the factors which might affect the outcomes of the transfer of cooled embryos. After the donors (n = 56) had been super-ovulated and mated, they were flushed at Day 8 or 9 post-mating. Of 487 collected embryos, 110 were refrigerated at 4°C for up to 5 days in holding medium (HM), flushing medium supplemented with 10% fetal calf serum (FM + FCS) or TCM199 supplemented with 50% FCS and HEPES (TCM + FCS + HEPES). Both fresh (n = 377) and cooled embryos were transferred individually into synchronized recipients. Pregnancy diagnoses were carried out at Days 18-19, 30 and 60 post-mating of the donors. Transferring of fresh embryos into the recipients resulted in significantly higher pregnancy rates at Days 18-19 (53.1% vs. 38.2%, P < 0.01), Day 30 (46.4% vs. 31.8%, P < 0.01) and Day 60 (42.4% vs. 26.4%, P < 0.005) compared with those of cooled embryos, respectively. Pregnancy rates after transferring cooled embryos progressively decreased with the prolongation of the storage period. A significant difference in the pregnancy rate (56% vs. 13%, respectively, P < 0.05) was recorded only at Days 18-19 between cooled embryos held for one day and those held for 5 days. The pregnancy rates at Days 18-19, Day 30 and Day 60 were non-significantly higher when TCM + HEPES and FCS medium used for cooling of embryos compared to those of FM + FCS or HM medium. Cooling of spherical embryos resulted in significantly higher pregnancy rates at Days 30 (45.6% vs. 17.0%, respectively, P < 0.005) and 60 (42.1 vs. 9.4%, respectively, P < 0.005) and a significantly lower pregnancy loss rate (11.1% vs. 66.6%, respectively, P < 0.005) compared to those resulting from cooling of folded embryos. Neither the size of embryo nor the day of flushing had a significant effect on the pregnancy and pregnancy loss rates after the transfer of cooled embryos. In conclusion, pregnancy could be obtained after the transfer of camel embryos refrigerated for up to 5 days. In addition, higher pregnancy rates could be obtained if only spherical embryos are selected for cooling.