Gamma and X-ray irradiation as a phytosanitary treatment against various stages of Planococcus lilacinus (Hemiptera: Pseudococcidae)

The cacao mealybug, Planococcus lilacinus Cock, is an important quarantine pest. Infested commodity should be subject to appropriate phytosanitary treatment, while irradiation is recommended for the cacao mealybug. Radio-tolerance comparison tests were conducted on the crawler, nymphs, and adult females of P. lilacinus at the X-ray radiation doses of 40, 80, and 120 Gy, respectively. The results showed that irradiation had a strong effect on preventing of development and reproduction; the adult female stage was identified as the most tolerant. During the following dose–response tests, among young and late females X-ray-irradiation (20–100 Gy), the late females were most tolerant when preventing F₁ generation 2nd instars emergence was used as the evaluation criterion. Minimum absorbed dose and its 95 % fiducial limits to provide probit 9 efficacy at 95 % confidence level (100 % mortality/inhibition in an estimated population of 93,616 individuals) were 131.5 Gy (122.5, 142.6 Gy) and 144.4 Gy (132.7, 159.4 Gy), estimating from the probit analysis on dose-mortality data of 1–30 and 1–10-day-old neonates laid by late females, respectively. In the large-scale confirmatory tests, a total of estimating 97,384 late females of P. lilacinus rearing on the pumpkins fruits were irradiated with gamma-ray at the target dose of 135 or 145 Gy (measured doses 126.1–163.0 Gy), which resulted in no F₁ generation 2nd nymphs developing during a 6-week post-treatment period. The treatment efficacy calculated is 99.9969 % at the 95 % confidence level. Therefore, a minimum absorbed dose of 163.0 Gy is recommended for phytosanitary treatment of P. lilacinus in infested commodity.     

Novel quinazolin-4-one derivatives as potentiating agents of doxorubicin cytotoxicity

We report the design, synthesis and biological evaluation of 17 novel 8-aryl-2-morpholino-3,4-dihydroquinazoline derivatives based on the standard model of DNA-PK and PI3K inhibitors. Novel compounds are sub-divided into two series where the second series of five derivatives was designed to have a better solubility profile over the first one. A combination of in vitro and in silico techniques suggested a plausible synergistic effect with doxorubicin of the most potent compound 14d on cell proliferation via DNA-PK and poly(ADP-ribose) polymerase-1 (PARP-1) inhibition, while alone having a negligible effect on cell proliferation.     

Discovery of pyrazolopyrimidine derivatives as potent BTK inhibitors with effective anticancer activity in MCL

Bruton’s tyrosine kinase (BTK) is a key regulator of B-cell receptor (BCR) signaling pathway and takes effect in the regulation of B-cell activation, survival, proliferation and differentiation. It has been proved that BTK is commonly overexpressed in mantle cell lymphoma (MCL), which makes it a focus of targeted therapy for MCL. Our studies yielded a novel series of pyrazolopyrimidine derivatives capable of potent inhibition of BTK. Notably, 12a showed higher selectivity against BTK and exhibited robust antiproliferative effects in both mantle cell lymphoma cell lines and primary patient tumor cells. Low micromolar doses of 12a induced strong cell apoptosis in Jeko-1 and Z138 cells.     

Recent advancement in the discovery and development of COX-2 inhibitors: Insight into biological activities and SAR studies (2008–2019)

Cyclooxygenase-2 is a very important physiological enzyme playing key roles in various biological functions especially in the mechanism of pain and inflammation, among other roles, making it a molecule of high interest to the pharmaceutical community as a target. COX 2 enzyme is induced only during inflammatory processes or cancer and reflects no role in the guarding stomach lining. Thus, selective COX-2 inhibition can significantly reduce the adverse effects including GI tract damage and hepatotoxic effects of traditional NSAIDs like aspirin, ibuprofen, etc. Recent developments on COX-2 inhibitors is primarily focused on improving the selectivity index of the drug towards COX-2 along with enhancing the potency of the drug by modifying the scaffolds of Coxibs currently in the market like Celecoxib, Indomethacin, Oxaprozin, etc. We have reported the progress on new COX-2 inhibitors in the last decade (2008–2019) focussing on five heterocyclic rings- Pyrazole, Indole, Oxazole, Pyridine and Pyrrole. The addition of various moieties to these core rings and their structure-activity relationship along with their molecular modelling data have been explored in the article. This review aims to aid medicinal chemists in the design and discovery of better COX-2 inhibitors constructed on these five heterocyclic pharmacophores.     

Likelihood-based experimental design for estimation of ED50

In selecting the best dosage choice for the estimation of ED50, it is natural to try to minimize the length of the confidence intervals. In this presentation, the dose allocation that minimizes the length of the likelihood-based confidence intervals is presented and compared with alternative allocations that have been proposed based on the length of different types of confidence intervals, such as those based on the asymptotic variance or on Fieller's Theorem. Effective strategies to deal with the parameter dependence of these allocations are explored. A series of experiments to evaluate the effect of small doses per fraction on the radiation tolerance of the rat cervical spinal cord provide the motivation and an illustration for the proposed procedures.     

Adaptive response and split-dose effect of radiation on the survival of mice

Although the importance of radiation-induced adaptive response has been recognized in human health, risk assessment and clinical application, the phenomenon has not been understood well in terms of survival of animals. To examine this aspect Swiss albino mice were irradiated with different doses (2–10 Gy) at 0015 Gy/s dose rate and observed on a regular basis for 30 days. Since almost 50% lethality was seen with 8 Gy, it was selected as the challenging dose for further studies. Irradiation of mice with conditioning doses (0.25 or 0.5 Gy) and subsequent exposure to 8 Gy caused significant increase in the survival of mice compared to irradiated control. The splitting of challenging dose did not influence the efficiency of conditioning doses (0.25 Gy and 0.5 Gy) to induce an adaptive response. However conditioning doses given in fractions (0.25 Gy + 0.25 Gy) or (0.5 Gy + 0.5 Gy) were able to modulate the response of challenging dose of 8 Gy. These results clearly showed the occurrence of adaptive response in terms of survival of animals. The conditioning dose given in small fractions seemed to be more effective. The findings have been discussed from a mechanistic point of view. The possible biological implications, potential medical benefits, uncertainties and controversies related to adaptive response have also been addressed     

A new dose-finding design for bivariate outcomes

For some drugs, toxicity events lead to early termination of treatment before a therapeutic response is observed. That is, there are three possible outcomes: toxicity (therapeutic response unknown), therapeutic response without toxicity, and no response with no toxicity. The optimal dose is the dose that maximizes the probability of the joint event, response, and no toxicity. The optimal safe dose is the dose, from among the doses with toxicity rate less than the maximum tolerable level, that maximizes the probability of response and no toxicity. We present a new sequential design to maximize the number of subjects assigned in the neighborhood of the optimal safe dose in a dose-finding trial with two outcomes.     

IRM-2近交系小鼠对电离辐射抗性的研究

目的观察IRM-2小鼠对电离辐射的耐受性.方法分析测定了IRM-2小鼠对137Csγ射线的LD50及经4.0Gy137Csγ射线照射后不同时间外周血白细胞、骨髓有核细胞总数、骨髓细胞DNA含量和脾结节的变化,并与亲代小鼠ICR和615进行了比较.结果用不同剂量的137Csγ射线照射后,IRM-2小鼠对γ射线的LD50比ICR和615小鼠分别高1.73～1.57Gy和1.44Gy;外周血白细胞数和骨髓有核细胞总数、骨髓细胞DNA含量下降的幅度小且恢复得快;CFU-S的增加也较ICR和615小鼠明显.结论IRM-2小鼠比一般的纯系和杂交品系小鼠具有更强的辐射抗性.     

Multigene DNA prime-boost vaccines for SHIV89.6P

We assessed four prime-boost vaccine regimens with a Gene Gun component for SHIV89.6P in Macaca nemestrina. A dosing experiment using beta-galactosidase plasmid showed that 30 or 45 shots per dose elicited higher titer antibody than smaller doses. For SHIV89.6P, we administered a six-plasmid vaccine capable of producing non-infectious virions in vivo in combination with either vaccinia recombinants or inactivated virus. DNA prime/vaccinia boost, or the reverse, elicited strong immune responses. The SHIV89.6P challenge virus was grown in M. nemestrina peripheral blood mononuclear cells and titered in vivo intrarectally. As has been observed for SHIV89.6P in M. mulatta, the infected M. nemestrina experienced rapid and severe loss of circulating CD4+ T cells. Vaccinated macaques were challenged three weeks after the last boost. DNA prime/vaccina boost or vaccina prime/DNA boost protected 11/12 animals from acute CD4+ T cell depletion and disease, while other regimens were not effective.