Targeted localized use of therapeutic antibodies: a review of non-systemic,topical and oral applications

Therapeutic antibodies provide important tools in the “medicine chest” of today’s clinician for the treatment of a range of disorders. Typically monoclonal or polyclonal antibodies are administered in large doses, either directly or indirectly into the circulation, via a systemic route which is well suited for disseminated ailments. Diseases confined within a specific localized tissue, however, may be treated more effectively and at reduced cost by a delivery system which targets directly the affected area. To explore the advantages of the local administration of antibodies, we reviewed current alternative, non-systemic delivery approaches which are in clinical use, being trialed or developed. These less conventional approaches comprise: (a) local injections, (b) topical and (c) peroral administration routes. Local delivery includes intra-ocular injections into the vitreal humor (i.e. Ranibizumab for age-related macular degeneration), subconjunctival injections (e.g. Bevacizumab for corneal neovascularization), intra-articular joint injections (i.e. anti-TNF alpha antibody for persistent inflammatory monoarthritis) and intratumoral or peritumoral injections (e.g. Ipilimumab for cancer). A range of other strategies, such as the local use of antibacterial antibodies, are also presented. Local injections of antibodies utilize doses which range from 1/10th to 1/100th of the required systemic dose therefore reducing both side-effects and treatment costs. In addition, any therapeutic antibody escaping from the local site of disease into the systemic circulation is immediately diluted within the large blood volume, further lowering the potential for unwanted effects. Needle-free topical application routes become an option when the condition is restricted locally to an external surface. The topical route may potentially be utilized in the form of eye drops for infections or corneal neovascularization or be applied to diseased skin for psoriasis, dermatitis, pyoderma gangrenosum, antibiotic resistant bacterial infections or ulcerated wounds. Diseases confined to the gastrointestinal tract can be targeted directly by applying antibody via the injection-free peroral route. The gastrointestinal tract is unusual in that its natural immuno-tolerant nature ensures the long-term safety of repeatedly ingesting heterologous antiserum or antibody materials. Without the stringent regulatory, purity and clean room requirements of manufacturing parenteral (injectable) antibodies, production costs are minimal, with the potential for more direct low-cost targeting of gastrointestinal diseases, especially with those caused by problematic antibiotic resistant or toxigenic bacteria (e.g. Clostridium difficile, Helicobacter pylori), viruses (e.g. rotavirus, norovirus) or inflammatory bowel disease (e.g. ulcerative colitis, Crohn’s disease). Use of the oral route has previously been hindered by excessive antibody digestion within the gastrointestinal tract; however, this limitation may be overcome by intelligently applying one or more strategies (i.e. decoy proteins, masking therapeutic antibody cleavage sites, pH modulation, enzyme inhibition or encapsulation). These aspects are additionally discussed in this review and novel insights also provided. With the development of new applications via local injections, topical and peroral routes, it is envisaged that an extended range of ailments will increasingly fall within the clinical scope of therapeutic antibodies further expanding this market.     

Extracellular vesicles concentration is a promising and important parameter for industrial bioprocess monitoring

Extracellular vesicles (EVs) are membrane vesicles that are produced by cells to be released into their microenvironment. In this study, we present the EV concentration as a new factor for optimization of industrial bioprocess control. The release of EVs depends on many cell properties, including cell activation and stress status, and cell death. Therefore, the EV concentration might provide a readout for identification of the cell state and the conditions during a bioprocess. Our data show that the EV concentration increased during the bioprocess, which indicated deteriorating conditions in the bioreactor. This increase in EV concentration in the fermentation broth was the consequence of two different processes: cell activation, and cell death. However, the release of EVs from activated living cells had a much weaker impact on EV concentration in the bioreactor than those released during cell death. EVs and cells in the bioprocess environment were quantified by flow cytometry. The most accurate data were obtained directly from unprocessed samples, making the monitoring of the EV concentration a rapid, easy, and cheap method. These EV concentrations reflect the conditions in the bioreactor and provide new information regarding the state of the bioprocess. Therefore, we suggest EV concentration as a new and important parameter for the monitoring of industrial bioprocesses.     

Exploring mild enzymatic sustainable routes for the synthesis of bio‐degradable aromatic‐aliphatic oligoesters

The application of Candida antarctica lipase B in enzyme‐catalyzed synthesis of aromatic‐aliphatic oligoesters is here reported. The aim of the present study is to systematically investigate the most favorable conditions for the enzyme catalyzed synthesis of aromatic‐aliphatic oligomers using commercially available monomers. Reaction conditions and enzyme selectivity for polymerization of various commercially available monomers were considered using different inactivated/activated aromatic monomers combined with linear polyols ranging from C₂ to C₁₂. The effect of various reaction solvents in enzymatic polymerization was assessed and toluene allowed to achieve the highest conversions for the reaction of dimethyl isophthalate with 1,4‐butanediol and with 1,10‐decanediol (88 and 87% monomer conversion respectively). M_w as high as 1512 Da was obtained from the reaction of dimethyl isophthalate with 1,10‐decanediol. The obtained oligomers have potential applications as raw materials in personal and home care formulations, for the production of aliphatic‐aromatic block co‐polymers or can be further functionalized with various moieties for a subsequent photo‐ or radical polymerization.     

Fecal antibody levels as a noninvasive method for measuring immunity to gastrointestinal nematodes in ecological studies

Among‐individual variation in antibody‐associated immunity to gastrointestinal nematode parasites (GIN) is known be associated with life‐history traits and vital rates in wild vertebrate systems. To date, measurement of levels of antibodies against GIN antigens in natural populations has exclusively been based on invasive blood sampling techniques. Previous work in laboratory rodents and ruminant livestock suggests that antibody measures from feces may provide a viable noninvasive approach. We measured total and anti‐GIN antibodies of different isotypes (immunoglobulin (Ig) G, IgA and IgE) from paired samples of plasma and feces from free‐living Soay sheep of different ages and sexes. We tested the correlations among these measures as well as their associations with body mass and Strongyle nematode fecal egg counts (FEC). Significant positive correlations were present among plasma and fecal anti‐GIN antibody levels for IgG and IgA. Generally, correlations between total antibody levels in plasma and feces were weaker and not significant. No significant relationships were found between any antibody measures and body mass; however, fecal anti‐GIN antibody levels were significantly negatively correlated with FEC. Our data clearly demonstrate the feasibility of measuring anti‐GIN antibodies from fecal samples collected in natural populations. Although associations of fecal antibody levels with their plasma counterparts and FEC were relatively weak, the presence of significant correlations in the predicted direction in a relatively small and heterogeneous sample suggests fecal antibody measures could be a useful, noninvasive addition to current eco‐immunological studies.     

不同培养模式下魏氏真眼点藻生长和产油特性的研究

为了解魏氏真眼点藻(Eustigmatos vischeri Hibberd)的生物学特性,探究"批量法"、"两步法"、"补料法"和"添加碳酸氢盐"4种不同培养模式对魏氏真眼点藻生长和油脂积累的影响,本文分别采用不同初始浓度的硝酸钠供应、更换培养基、分次少量补加硝酸钠及添加低浓度Na HCO3或NH4HCO3等方法培养魏氏真眼点藻。结果显示,"批量"培养下,硝酸钠浓度为3.0 mmol/L时藻细胞生物量达到8.41 g/L,油脂最高可达到65.16%,油脂产率为0.30 g·L-1·d-1。"两步法"和"补料法"培养对藻细胞油脂积累没有显著影响,而通过"添加碳酸氢盐"培养对该藻细胞生长和油脂积累的效果最显著,其中Na NO3+NH4HCO3组生物量达到11.56 g/L,油脂最高达60.92%,与相同氮浓度"批量"培养相比,生物质浓度提高了1.0 g/L,总脂含量提高了10%,大大提高了该藻的总脂产率(达到0.39 g·L-1·d-1)。因此,魏氏真眼点藻是一株高产油藻株,当添加低浓度碳酸氢铵时最有利于促进该藻生物质浓度和总脂含量的提高,这是一种最佳的培养模式,具有潜在的开发和利用价值。     

Evaluation of soil respiration and soil CO2 concentration in a lowland moist forest in Panama

Soil gas exchange was investigated in a lowland moist forest in Panama. Soil water table level and soil redox potentials indicate that the soils are not waterlogged. Substantial microspatial variation exists for soil respiration and soil CO₂ concentration. During the rainy season, soil CO₂ at 40 cm below the surface accumulates to 2.3%–4.6% and is correlated with rainfall during the previous two weeks. Temporal changes in soil CO₂ are rapid, large and share similar trends between sampling points. Possible effects of soil CO₂ changes on plant growth or phenology are discussed.     

Effects of soil applied herbicides on leaf nitrate reductase and crude protein in the leaf and seed of two cowpea cultivars

A glass-house study was conducted to determine the effects of four commonly used herbicides (pendimethalin, metobromuron, metolachlor and prometryne) applied pre-emergence at rates of 0, 0.125, 0.625 and 1.25 kg ha^–1, on leaf nitrate concentration (NO₃–C), nitrate reductase activity (NRA), leaf crude protein and seed protein in two cowpea cultivars, 60 day (60D) and Ife brown (IB).Control and treated plants of both cultivars showed separate peaks for NO₃–C and NRA, 49 days after planting (DAP) and 35 DAP for 60D and IB respectively. Herbicide treatment generally enhanced NO₃–C but tended to decrease NRA in both cultivars. Howver, metobromuron at 0.625 kg ha^–1 increased NRA throughout the growth period with an optimum increase of 52.5%, over the control, at 35 DAP. Pendimethalin increased NO₃–C NRA and leaf protein but did not influence seed protein appreciably. In contrast metobromuron increased NO₃–C, decreased NRA, but increased seed protein by 29.6% over the control at 0.125 kg ha^–1 in 60D. Metolachlor and prometryne were most inhibitory to seed protein development. In addition, metolachlor reversed the interdependence of NO₃–C and NRA.     

Interspecific variation in assimilation of 14CO2 into C4 acids by leaves of C3, C4 and C3−C4 intermediate Flaveria species near the CO2 compensation concentration

The assimilation of ¹⁴CO₂ into the C₄ acids malate and aspartate by leaves of C₃, C₄ and C₃–C₄ intermediate Flaveria species was investigated near the CO₂ compensation concentration ^* in order to determine the potential role of phosphoenolpyruvate (PEP) carboxylase (EC 4.1.1.31) in reducing photorespiration in the intermediates. Relative to air concentrations of CO₂, the proportion of CO₂ fixed by PEP carboxylase at ^* increased in all six C₃–C₄ intermediate species examined. However, F. floridana J.R. Johnston and F. ramosissima Klatt were shown to be markedly less responsive to reduced external CO₂, with only about a 1.6-fold enhancement of CO₂ assimilation by PEP carboxylase, as compared to a 3.0- to 3.7-fold increase for the other C₃–C₄ species examined, namely, F. linearis Lag., F. anomala B.L. Robinson, F. chloraefolia A. Gray and F. pubescens Rydb. The C₃ species F. pringlei Gandoger and F. cronquistii A.M. Powell exhibited a 1.5- and 2.9-fold increase in labeled malate and aspartate, respectively, at ^*. Assimilation of CO₂ by PEP carboxylase in the C₄ species F. trinervia (Spreng.) C. Mohr, F. australasica Hook., and the C₄-like species F. brownii A.M. Powell was relatively insensitive to subatmospheric levels of CO₂. The interspecific variation among the intermediate Flaverias may signify that F. floridana and F. ramosissima possess a more C₄-like compartmentation of PEP carboxylase and ribulose-1,5-bisphosphate carboxylase/oxygenase (EC 4.1.1.39) between the mesophyll and bundle-sheath cells. Chasing recently labeled malate and aspartate with ¹²CO₂ for 5 min at ^* resulted in an apparent turnover of 25% and 30% of the radiocarbon in these C₄ acids for F. ramosissima and F. floridana, respectively. No substantial turnover was detected for F. linearis, F. anomala, F. chloraefolia or F. pubescens. With the exception of F. floridana and F. ramosissima, it is unlikely that enhanced CO₂ fixation by PEP carboxylase at the CO₂ compensation concentration is a major mechanism for reducing photorespiration in the intermediate Flaveria species. Moreover, these findings support previous related ¹⁴CO₂-labeling studies at air-levels of CO₂ which indicated that F. floridana and F. ramosissima were more C₄-like intermediate species. This is further substantiated by the demonstration that F. floridana PEP carboxylase, like the enzyme in C₄ plants, undergoes a substantial activation (2.2-fold) upon illuminating dark-adapted green leaves. In contrast, light activation was not observed for the enzyme in F. linearis or F. chloraefolia.Abbreviations and symbols PEP phosphoenolpyruvate - Rubisco ribulose-1,5-bisphosphate carboxylase/oxygenase - CO₂ compensation concentration - ^* a subatmospheric level of CO₂ approximating Published as Paper No. 8832, Journal Series, Nebraska Agricultural Research Division     

The use of sieving during standard pollen pre-treatment of samples of fossil deposits to enhance the concentration of large pollen grains

Small pollen grains and fine particles of the organic matrix in samples of a coarse detritus mud and a blanket peal deposit were removed by sieving through 30μ polyester mesh after digestion with KOH and acetolysis during standard pollen pre-treatment. The technique enhanced the number of large pollen grains m the sample. There was also an increase in the range of taxa which produce huge grains. The method provided a means of estimating the ratio of any scarce large pollen grain to the total grain sum in samples prepared by standard methods of pre-treatment.     

Responses to internal nitrogen and phosphorus concentrations of two Taraxacum microspecies of contrasting mineral ecology: critical N and P concentrations of whole plants

Of the two Taraxacum microspecies used. Taraxacum sellandii Dahlst. usually occurs in grasslands with a high nutrient level; Taraxacum nordstedtii Dahlst. is generally restricted to undisturbed and mineral-poor habitats. Growth response curves for internal N and P were established, based on relative yield of (whole) plant tissue water and (whole plant) internal mineral concentration on a tissue water basis. Critical nutrient concentrations of N and P were determined from the response curves derived. For both macroelements, T. nordstedtii showed lower critical nutrient concentrations. The difference in critical N concentrations coincided with differences in internal NO₃^-₃ concentrations between the microspecies. Finally, we discuss the use of tissue water as a (whole) plant growth parameter and internal mineral concentration on tissue water basis as a parameter describing the mineral status.