Immunomodulation of tahneeq method in IL-12 and CD8+ T-Lymphocyte,an in-vivo study in neonatal rats

Stimulation of the neonatal immune system is quite important for the proliferation and differentiation of antigen-presenting cells (APCs) and T cells. Tahneeq is a traditional method to manually rub the palatal mucosa of newborn babies with premasticated Ajwa palm dates. The present study was to investigate the tahneeq effects on IL-12 expression of dendritic cells (DCs) and blood T lymphocytes expressing CD8⁺ in neonatal Wistar rats. The number of 90 healthy neonatal Wistar rats have randomly divided into three groups: control group received breastmilk only, treatment group (T1) receiving breast milk + mild-scratched intensity of tahneeq, and T2 group received breastmilk + strong-scratched intensity of tahneeq on the palatal and gingival mucosa immediately after birth.  Seven neonatal Wistar rats in all groups were then sacrificed in three hours after birth and days 1, 5, 7, 13, and 30 treatment. IL-12 expression in the palatal and gingival mucosa was determined using immunohistochemical staining, and blood CD8⁺ T-lymphocytes were quantified using a flow cytometer. One way ANOVA was used to analyze the percentage of IL-12 and CD8⁺ T-lymphocytes among neonatal Wistar rat groups.  The T1 and T2 newborn rat groups had significantly higher IL-12 expression than the control group (p<0.001). The increased IL-12 expression in T2 groups significantly increased (p<0.001) compared to the IL-12 expression in the T1 and control groups. The percentage of  CD8⁺ T lymphocytes in all neonatal rat groups increased on three hours after birth and day 30 treatment but remained constant on days 5 and 7 treatment and decreased on day 13 treatment. At 5, 13, and 30^th days treatment,  the percentage of CD8⁺ T lymphocytes in T1 and T2 neonatal rat groups was significantly higher (p<0.05) than that in the control group. In conclusion, the impact on systemic CD8⁺ T cells did not influence by the depth of the scratch. Both mild and strong tahneeq increased the systemic CD8⁺ T-lymphocytes in neonatal Wistar rats. The roles of anti-inflammatory cytokines and Treg cells should be further investigated to unravel those different results for the development of mucosal immunity in neonates.     

Museum egg collections as stores of long-term phenological data

Museum collections hold large amounts of data on collecting dates and localities of eggs collected over the past 150 years. Egg collections hold the longest available time series for a wide range of bird species on a large spatial scale. Using data for two British species I investigate whether egg collection data can be used in phenological research. A method is presented allowing laying dates to be estimated from collecting dates. Problems and biases in the data are highlighted. Both the dipper and song thrush have started laying earlier over the past 150 years. The advance in laying is significantly correlated with mean March temperature. Received: 25 October 2000 / Revised: 14 May 2001 / Accepted: 16 May 2001     

DNA reassociation kinetics and hybridization in different angiosperms

Reassociation kinetics ofDaucus carota andPetroselinum crispum (Apiaceae), andDatura innoxia (Solanaceae) are presented. Hybridization of³H-labelled DNA of two carrot cultivars indicate strong qualitative homologies of DNA sequences; nevertheless, certain quantitative differences in some Cotregions seem to exist. However, homologous sequences ofDaucus DNA with DNA ofDatura, and, suprisingly, even with DNA ofPetroselinum are very restricted: between 8% in the repeated regions and ca. 7–9% in the unique regions.     

不同灌溉量夏玉米叶绿素含量的高光谱特征及其反演

植物叶绿素含量直接影响其光合作用，并与植物的光谱特征密切相关。以夏玉米为研究对象，采用人工控水方法研究了夏玉米七叶期不同灌溉量下冠层叶绿素含量特征及其与光谱特征之间的关系。结果表明：灌溉量越少，夏玉米叶片叶绿素含量越低，冠层光谱反射率越高，绿峰位置"红移"，而红边位置"蓝移"。叶绿素含量与光谱特征参数、植被光谱指数之间存在极显著相关关系，据此建立了冠层叶绿素含量高光谱估算模型，且基于植被指数模型较基于单一光谱特征参数模型模拟效果更好。研究结果可为夏玉米叶绿素含量的快速无损测定以及夏玉米干旱监测提供依据。     

Preparation and Evaluation of Differently Sulfonated Styrene–Divinylbenzene Cross-linked Copolymer Cationic Exchange Resins as Novel Carriers for Drug Delivery

The differently sulfonated styrene–divinylbenzene cross-linked copolymer cationic exchange resins were prepared by oil-in-water polymerization and varied degrees of sulfonation. Several characteristics of the obtained resins were evaluated, i.e., Fourier transform infrared spectra, the ion-exchange capacity, microscopic morphology, size, and swelling. The resin characteristics were altered in relation to the degree of sulfonation, proving that differently sulfonated resins could be prepared. The behavior of chlorpheniramine (CPM) loading and in vitro release in the USP simulated gastric (SGF) and intestinal fluids (SIF) of the obtained resins were also evaluated. The CPM loaded in the resinates (drug-loaded resins) increased with the increasing degree of sulfonic group and hence the drug binding site in the employed resins. The CPM release was lower from the resins with the higher degree of sulfonic group due to the increase in the diffusive path depth. The CPM release was obviously lower in SGF than SIF because CPM, a weak base drug, ionized to a greater extent in SGF and then preferred binding with rather than releasing from the resins. In conclusion, the differently sulfonated resins could be utilized as novel carriers for drug delivery.     

不同播期对紫花苜蓿生长性状及越冬性的影响研究

采用随机试验设计方法,在宁南旱作农业区进行了不同播期对紫花苜蓿出苗率、生长发育、越冬率和产草量影响的研究。结果表明,在宁南地区人工种植紫花苜蓿的出苗率与播期温度存在极显著正相关关系,而不同播期土壤耕层含水量变化率较小,且基本能满足苜蓿萌发与生长的需要;播期越早,根颈越粗,入土越深,但4月份前播种,出苗率低,群体小且易形成“小老苗”;7月份以后播种。由于生长期短,植株根颈细嫩,越冬率很低或完全冻死。综合不同播期出苗率、产草量和越冬率等因素,认为在宁南地区紫花苜蓿的适宜播种期应在4月30日～6月30日。     

日本血吸虫虫卵、童虫和雌雄成虫膜蛋白的双向电泳

血吸虫寄生生活复杂,中间宿主和终末宿主转换,有性繁殖和无性繁殖交替,由其感染引起的血吸虫病仍严重危害人畜健康(陈贤义等,2002).研究表明,血吸虫不仅能利用宿主的免疫信号分子伪装自己获得宿主的免疫兼容(Salzet et al.,2000),而且还在血吸虫中克隆到宿主信号分子的受体(Ahmed et al.,2001).     

光照、盐分和埋深对无芒隐子草和条叶车前种子萌发的影响

光照、盐分和埋深对无芒隐子草(Cleistogenes songorica)和条叶车前(Plantago lessingii)种子萌发的影响研究结果显示,无芒隐子草和条叶车前种子为萌发需光性种子。随着盐(NaCl)浓度的增加,2种植物种子的发芽率呈直线下降趋势(P<0.01),但以条叶车前下降较为缓慢。当盐分浓度为0.4 mol.L-1时,2种植物种子皆不能萌发。低浓度的盐分促进胚根的生长,高浓度则表现为抑制作用;盐分对胚芽的生长则一直起抑制作用。2种植物种子发芽率随埋深的增加而减小,当埋深>2 cm时不能萌发。     

Sowing seasons and drying methods during post-harvest influence the seed vigour of soybean (Glycine max (L.) Merr.)

Experiments were conducted to study the influence of sowing seasons and drying methods on the seed vigour of two spring soybean (Glycine max (L.) Merr.) cultivars. Two cultivars, ‘Huachun18’ and ‘Huachun 14’, were sown in three seasons viz., spring, summer and autumn and the harvested seeds were dried using three different methods. The results showed that soybean sown in spring had a higher number of branches per plant, pods per branch and seed weight, and consequently resulted in higher seed yields than that of soybean sown in autumn or summer seasons. Seeds sown in the autumn season had the lowest values of electrical conductivity during seed imbibitions, higher peroxidase (POD) activity in germinated seedlings and lower contamination by the seed-borne fungi on the MS medium, which indirectly improved the seed vigour, which was followed by summer sown seeds. Seeds sown during the spring season resulted in poor seed vigour. In addition, the effect of drying methods on the seed vigour was also clarified. Seeds that hung for four days before threshing and then air-dried had the poorest seed vigour which was determined by germination, electrical conductivity, POD activity and seed borne fungal growth. There was no difference in seed vigour between other methods, i.e. seeds threshed directly at harvest and then air-dried on a bamboo sifter or concrete floor. These results indicated that autumn sowing soybean and the drying method in which seeds were threshed directly at harvest and then air-dried on a bamboo sifter resulted in higher seed vigour.