恶性疟原虫抗原表位的亚单位疫苗与DNA疫苗的联合免疫

构建了含有恶性疟原虫抗原基因 ( AWTE)的真核表达质粒 p CMV- AWTE,以及能在大肠杆菌中得到分泌性表达的原核表达质粒 p MC0 5 ,表达的蛋白 AWTE保持了疟原虫抗原的抗原性。将 p CMV- AWTE以及 AWTE两者混合各 1 0μg鼻腔免疫小鼠 ,一次后诱导机体产生了较高水平的体液免疫及细胞免疫     

Multifunctional liposomes for nasal delivery of the anti-Alzheimer drug tacrine hydrochloride

The purpose of this study was the development of multifunctional liposomes for nasal administration of tacrine hydrochloride. Liposomes were prepared using traditional excipients (cholesterol and phosphatidylcholine), partly enriched with α-tocopherol and/or Omega3 fatty acids. This approach was chosen in order to obtain at the same time two positive results: an enhanced drug permeation through nasal mucosa and a concomitant neuroprotective effect. Several liposome formulations were prepared using the Reverse Phase Evaporation technique followed by membrane filter extrusion. In particular, liposome capacity to enhance drug permeation was evaluated by means of membrane permeation and cellular uptake studies. Furthermore, liposome effect on neuronal viability and intracellular ROS production was evaluated as well as their cytoprotective effect against oxidative stress. All liposome formulations showed a mean diameter in the range of 175?nm to 219?nm with polydispersity index lower than 0.22, a lightly negative zeta potential and excellent encapsulation efficiency. Moreover, along with good mucoadhesive properties, multifunctional liposomes showed a markedly increase in tacrine permeability, which can be related to liposome fusion with cellular membrane, a hypothesis, which was also supported by cellular uptake studies. Finally, the addition of α-tocopherol without Omega3 fatty acids, was found to increase the neuroprotective activity and antioxidant properties of liposomes.     

Cryptococcus neoformans: A central nervous system isolate from an AIDS patient that is rhinotropic in a normal mouse model

A strain of Cryptococcus neoformans that was isolated from the cerebrospinal fluid of a human diagnosed as having acquired immunodeficiency syndrome (AIDS), and that produced cutaneous lesions in experimentally infected, normal mice is described. Although no unusual cutaneous manifestations were noted in the patient's records, this isolate of C. neoformans proved to be dermotropic when injected intravenously into CD-1 mice. The LD₅₀ at 28 days post infection ranged from 3.6–7.5×10⁵ cells per mouse, and in vitro growth rate studies demonstrated that this isolate grew well at 35 °C and at 37 °C, but did not grow at 40 °C and higher. This isolate was rhinotropic producing large granulomatous lesions in the nasal tissues. Other cutaneous tissues affected were the periocular tissues, ears, feet and tail, although the granulomas were nodular in structure and less necrotic than the nasal lesions. The brain, lungs, liver, kidneys and spleen also were culture positive for C. neoformans. Histopathologically, each affected tissue examined had large densities of yeast cells and a chronic, granulomatous host response. Animals surviving the infection appeared to develop a commensal-type relationship with the infective yeast. This is the first report of an isolate of C. neoformans from an AIDS patient that has caused cutaneous manifestations in an animal model. The model described in this report may be useful for elucidating pathogenic mechanisms of cryptococcosis, particularly cutaneous manifestations of the disease.     

Persistence of infection in mice inoculated intranasally with Cryptococcus neoformans

Cryptococcus neoformans was instilled intranasally into mice which were periodically sacrificed to determine the course of infection. Cryptococci persisted within the nasal passages throughout the 90 day study. Extranasal dissemination began 14–28 days after instillation and was still demonstrable 90 days post-exposure. Ten percent mortality was observed in mice receiving 10⁶ cryptococci, while no mortality was observed in mice exposed to 10³ or 10⁴ cryptococci. Our research suggests that nasal colonization with C. neoformans can precede pulmonary and systemic cryptococcosis by weeks or months.     

The influence of oxygen concentrations on denitrification in soil

Summary The influence of different O₂ concentrations on denitrification was studied in an agricultural soil. In both nitrate and nitrite amended soil, denitrification was not observed until the O₂ concentration decreased to 0.20 and 0.21 mol/ml, respectively. Denitrification was not observed in soil samples with O₂ concentrations above 0.28 mol/ml in the gas phase. These findings suggest that a completely anoxic environment is not required for denitrification to occur in soil.     

经鼻加温加湿高流量吸氧对重症肺炎伴呼吸衰竭患儿血气指标、肺功能及细胞因子水平的影响

摘要 目的：观察经鼻加温加湿高流量吸氧（HFNC）对重症肺炎伴呼吸衰竭患儿血气指标、肺功能及细胞因子水平的影响。方法：选取南京医科大学附属儿童医院2020年3月~2022年3月期间收治的86例重症肺炎伴呼吸衰竭患儿,按照随机数字表法分为经鼻持续气道正压通气（nCPAP）组和HFNC组,各为43例。对比两组临床相关指标、血气指标、肺功能及细胞因子水平,同时观察两组镇静剂使用、预后及并发症发生情况。结果：HFNC组的机械通气时间、咳嗽缓解时间、肺部啰音消失时间、入住儿童重症监护室（PICU）时间均短于nCPAP组（P<0.05）。两组患儿治疗后心率（HR）升高,呼吸频率（RR）下降,且HFNC组的变化大于nCPAP组（P<0.05）。两组患儿治疗后pH值、血氧分压（PO₂）、血氧饱和度（SpO₂）、氧合指数（OI）均升高,且HFNC组高于nCPAP组（P<0.05）。两组患儿治疗后用力肺活量（FVC）、1s用力呼气容积（FEV1）、用力呼气时最高呼气流速（PEF）升高,且HFNC组高于nCPAP组（P<0.05）。两组患儿治疗后降钙素原（PCT）、白细胞介素（IL-6）和肿瘤坏死因子（TNF-α）下降,且HFNC组低于nCPAP组（P<0.05）。HFNC组镇静剂使用、再住院例数均少于nCPAP组（P<0.05）。两组死亡例数、并发症发生率组间对比未见统计学差异（P>0.05）。结论：HFNC可有效缓解重症肺炎伴呼吸衰竭患儿的临床症状,改善血气指标、肺功能及细胞因子水平。     

Phage P22 helps phage MB78 to overcome blockage of DNA maturation in rifampicin-resistant host

Bacteriophage MB78, a virulent phage ofSalmonella typhimurium cannot grow in rifampicin-resistant mutant (rif-39) of the host having altered RNA polymerase. The temperate phage P22 which cannot multiply in presence of the virulent phage MB78 can, however, help MB78 to overcome replication inhibition in rif-39. The processing of concatemeric phage DNA to monomer is blocked in this nonpermissive host. Superinfection with P22 induces synthesis of at least five P22 specific polypeptides which help phage MB78 in the processing of the concatemeric DNA and maturation of phage particles.     

Particle deposition and sensory drive

The mutualism between chemical cues emitted into the air and variations in how primates respond to them using olfaction has demonstrated aspects of species‐specific adaptations. Building on this mutualism we can look at particle deposition as another means to understanding how various environments may have elicited biological changes that enable efficient communication. Research on particle movement and deposition within the nasal cavity is largely based on questions about health as it relates to drug delivery systems and overall olfactory function in modern humans. With increased access to 3D models and the use of computational fluid dynamic analysis, researchers have been able to simulate site‐specific deposition, to determine what particles are making it through the nasal cavity to the main olfactory epithelium, which ultimately leads to processing in the olfactory bulb. Here we discuss particle deposition research, sensory drive and their potential applications to evolutionary anthropology.     

Nasal Discs and the Vital Rates of Lesser Scaup

Nasal discs have been used to identify ducks in studies of survival and reproduction. To date, there has not been a comprehensive assessment of nasal-disc effects on the vital rates of wild ducks. We applied nasal discs to 603 juvenile and 784 adult lesser scaup (Aythya affinis) females from a population breeding in southwest Montana, USA, and released 1,399 juvenile and 71 adult females wearing only metal leg bands between June 2005 and September 2016. Using resighting, recapture, and hunter-recovery data collected from those individuals, we estimated survival and recovery probability with multistate capture-recapture models in Program MARK. We also assessed if recovery distance from our study site and pre-breeding and brood-rearing body condition were diminished for females wearing nasal discs. Model-averaged survival probabilities were 0.231 ± 0.035 (SE) for juveniles and 0.482 ± 0.019 for adults released with nasal discs. Survival was 1.8–3.4 times higher for females released with metal leg bands when compared to those released with nasal discs; survival of these juveniles was 0.433 ± 0.049 and 0.693 ± 0.039 for adults. We did not find evidence for recovery probability or recovery distance varying between females that wore nasal discs and those that did not. During the pre-breeding and brood-rearing seasons, we did not find females wearing nasal discs to be in lower body condition when compared to unmarked females. Our comprehensive assessment of nasal discs on wild lesser scaup suggests that survival probabilities estimated from nasal-marked study populations should be cautiously interpreted as minimum estimates. © 2021 The Wildlife Society.