L-glutamic acid-g-poly hydroxyethyl methacrylate nanoparticles: acute and sub-acute toxicity and biodistribution potential in mice

The aim of this safety study in mice was to determine in vivo toxicity and biodistribution potential of a single and multiple doses of L-glutamic acid-g-p(HEMA) polymeric nanoparticles as a drug delivery system. The single dose did not cause any lethal effect, and its acute oral LD₅₀ was >2.000 mg/kg body weight (bw). Multiple doses (25, 50, or 100 mg/kg bw) given over 28 days resulted in no significant differences in body and relative organ weights compared to control. These results are supported by biochemical and histological findings. Moreover, nanoparticle exposure did not result in statistically significant differences in micronucleus counts in bone marrow cells compared to control. Nanoparticle distribution was time-dependent, and they reached the organs and even bone marrow by hour 6, as established by ex vivo imaging with the IVIS^® spectrum imaging system. In conclusion, L-glutamic acid-g-p(HEMA) polymeric nanoparticles appear biocompatible and have a potential use as a drug delivery system.KEY WORDS: biocompatibility, blood biochemistry, genotoxicity, histology, in vivo toxicity, micronucleus test, polymers     

肿瘤内微生物群（组）相关研究进展

肿瘤内微生物群（组）已被证实广泛存在于各类肿瘤内，对肿瘤微环境的形成、调控肿瘤生长均发挥着重要作用，并直接影响药物干预肿瘤的疗效。随着新一代基因测序技术的广泛应用，针对肿瘤内微生物功能和分类的研究日益增温。诸多研究表明不同肿瘤内微生物种属分布不同，且不同种微生物所发挥的促/抑瘤机制不同。针对肿瘤内微生物的编辑技术亦取得了许多成果，有望成为检测与治疗肿瘤的新手段。本文旨在对近年来肿瘤内微生物群（组）相关研究进展加以综述，并展望其应用前景。     

Cytotoxic and Apoptotic Effects of Recombinant Subtilase Cytotoxin Variants of Shiga Toxin-Producing Escherichia coli

In this study, the cytotoxicity of the recently described subtilase variant SubAB_2-2 of Shiga toxin-producing Escherichia coli was determined and compared to the plasmid-encoded SubAB₁ and the chromosome-encoded SubAB_2-1 variant. The genes for the respective enzymatic active (A) subunits and binding (B) subunits of the subtilase toxins were amplified and cloned. The recombinant toxin subunits were expressed and purified. Their cytotoxicity on Vero cells was measured for the single A and B subunits, as well as for mixtures of both, to analyze whether hybrids with toxic activity can be identified. The results demonstrated that all three SubAB variants are toxic for Vero cells. However, the values for the 50% cytotoxic dose (CD₅₀) differ for the individual variants. Highest cytotoxicity was shown for SubAB₁. Moreover, hybrids of subunits from different subtilase toxins can be obtained which cause substantial cytotoxicity to Vero cells after mixing the A and B subunits prior to application to the cells, which is characteristic for binary toxins. Furthermore, higher concentrations of the enzymatic subunit SubA₁ exhibited cytotoxic effects in the absence of the respective B₁ subunit. A more detailed investigation in the human HeLa cell line revealed that SubA₁ alone induced apoptosis, while the B₁ subunit alone did not induce cell death.     

Early Benefit Assessments in Oncology in Germany: How Can a Clinically Relevant Endpoint Not Be Relevant to Patients?

After 4 years of early benefit assessment (EBA) in Germany, it is becoming evident that the Federal Joint Committee (FJC) frequently considers well-established clinical endpoints as not being relevant to patients. Focusing on assessments of oncology medicines, we analysed the FJC’s view on primary endpoints and compared it with the approach used by regulatory authorities. Mortality data were accepted by both stakeholders. Whereas regulatory authorities accepted primary morbidity endpoints such as progression-free survival and response rates, the FJC mostly excluded these from its assessments. Health-related quality of life (HRQoL) data have been poorly reflected in the approval process; for EBAs, those data have rarely impacted on benefit ratings. We argue that agreement between regulatory authorities and the FJC is required regarding primary study endpoints that are relevant to patients, and that clarification of acceptable endpoints by the FJC, especially in the morbidity domain, has to be provided. Moreover, in order to fully acknowledge the benefit of a new medicinal product, mortality, morbidity and HRQoL should be weighted differentially, according to the condition.     

Microbiological quality of non-sterile pharmaceutical products

In microbiological terms, pharmaceutical products can be divided into two groups: sterile and non-sterile. Non-sterile drugs must satisfy the appropriate microbiological purity criteria which are included in pharmacopoeial monographs. Pharmacopoeial studies are prepared specifically with a view to ensuring that the medicinal product is therapeutically effective and safe for the patient. The analysis comprised the results of microbiological purity tests performed before the products are marketed. Total of 1285 samples of non-sterile drugs manufactured by different pharmaceutical plants in Polish were taken into study. The microbiological quality of drugs was assessed in accordance with the criteria included in the European Pharmacopoeia (EP). An analysis of test results demonstrated that the percentage of non-compliant samples was 1.87%. The groups of drugs, which the most often did not satisfy EPs’ requirements, were drugs containing raw materials of natural origin (5.7%). The samples of studied drugs that did not meet the criteria contained in EP, exceed the maximum allowable microbiological count limits and contained microbes whose presence is prohibited. The most common non-compliance was the excessive levels of the maximum acceptable fungal count (n = 12) and the excessive the maximum acceptable aerobic microbial count (n = 10).     

Environmental and Pharmacological Modulation of Amphetamine-Induced 50-kHz Ultrasonic Vocalizations in Rats

Rats emit high-frequency 50-kHz ultrasonic vocalizations (USV) in appetitive situations like social interactions. Drugs of abuse are probably the most potent non-social elicitors of 50-kHz USV, possibly reflecting their euphorigenic properties. Psychostimulants induce the strongest elevation in 50-kHz USV emission, particularly amphetamine (AMPH), either when applied systemically or locally into the nucleus accumbens (Nacc). Emission of AMPH-induced 50-kHz USV depends on test context, such as the presence of conspecifics, and can be manipulated pharmacologically by targeting major neurotransmitter systems, including dopamine (DA), noradrenaline (NA), and serotonin (5-HT), but also protein kinase C (PKC) signaling. Several D₁ and D₂ receptor antagonists, as well as typical and atypical antipsychotics block the AMPH-induced elevation in 50-kHz USV. Inhibiting D₁ and D₂ receptors in the Nacc abolishes AMPH-induced 50-kHz USV, indicating a key role for this brain area. NA neurotransmission also regulates AMPH-induced 50-kHz USV emission given that α₁ receptor antagonists and α₂ receptor agonists exert attenuating effects. Supporting the involvement of the 5-HT system, AMPH-induced 50-kHz USV are attenuated by 5-HT_2C receptor activation, whereas 5-HT_2C receptor antagonism leads to the opposite effect. Finally, treatment with lithium, tamoxifen, and myricitrin was all found to result in a complete abolishment of the AMPH-induced increase in 50-kHz USV, suggesting the involvement of PKC signaling. Neurotransmitter systems involved in AMPH-induced 50-kHz USV emission only partially overlap with other AMPH-induced behaviors like hyperlocomotion. The validity of AMPH-induced 50-kHz USV as a preclinical model for neuropsychiatric disorders is discussed, particularly with relevance to altered drive and mood seen in bipolar disorder.