Polyphenols-Enrichment of Vienna Sausages Using Microcapsules Containing Acidic Aqueous Extract of Boletus edulis Mushrooms

Polyphenols are ubiquitous by-products in many plant foods. Their intake has been linked to health benefits like the reduced incidence of cardiovascular disease, diabetes, and cancer. These bioactive compounds can be successfully extracted from Boletus edulis mushrooms with acidic water. However, such extract could influence the sensory or textural properties of the product to be enriched; this inconvenience can be avoided by microencapsulating it using spray drying. In this study, the Vienna sausages were reformulated by replacing 2% of the cured meat with microcapsules containing an acidic aqueous extract of Boletus edulis mushrooms and by replacing ice flakes, an ingredient that represents 22.9% of the manufacturing recipe, with ice cubes from the same extract aiming to obtain a polyphenol enriched product. The results showed a higher content of polyphenols in sausages with extract (VSe; 568.92 μg/g) and microcapsules (VSm; 523.03 μg/g) than in the control ones (455.41 μg/g), with significant differences for 2,4-dihydroxybenzoic acid, protocatechuic acid, and 1-O-galloyl-β-D-glucose. However, because of the oxidative stress caused to the microcapsules by the extract's spray drying, VSm had the highest oxidation state. PV and TBARS levels varied with storage time in all formulations, but given the short period tested, they were well below the allowed/recommended limit. The extract, as such, negatively affected the appearance, odor, and taste of Vienna sausages. The microcapsules, instead, determined an increase in their acceptance rate among consumers; they also prevented moisture loss and color changes during storage. In conclusion, microcapsules are more suitable for use as a polyphenol enrichment ingredient in Vienna sausages than the extract.

Determination of Coenzyme Q10 Content in Food By-Products and Waste by High-Performance Liquid Chromatography Coupled with Diode Array Detection

Coenzyme Q10 (CoQ10) is a vitamin-like compound found naturally in plant- and animal-derived materials. This study aimed to determine the level of CoQ10 in some food by-products (oil press cakes) and waste (fish meat and chicken hearts) to recover this compound for further use as a dietary supplement. The analytical method involved ultrasonic extraction using 2-propanol, followed by high-performance liquid chromatography with diode array detection (HPLC-DAD). The HPLC-DAD method was validated in terms of linearity and measuring range, limits of detection (LOD) and quantification (LOQ), trueness, and precision. As a result, the calibration curve of CoQ10 was linear over the concentration range of 1-200 µg/mL, with an LOD of 22 µg/mL and an LOQ of 0.65 µg/mL. The CoQ10 content varied from not detected in the hempseed press cake and the fish meat to 84.80 µg/g in the pumpkin press cake and 383.25 µg/g in the lyophilized chicken hearts; very good recovery rates and relative standard deviations (RSDs) were obtained for the pumpkin press cake (100.9-116.0% with RSDs between 0.05-0.2%) and the chicken hearts (99.3-106.9% CH with RSDs between 0.5-0.7%), showing the analytical method's trueness and precision and thus its accuracy. In conclusion, a simple and reliable method for determining CoQ10 levels has been developed here.

Impact of Lavender Flower Powder as a Flavoring Ingredient on Volatile Composition and Quality Characteristics of Gouda-Type Cheese during Ripening

This study aimed to formulate a Gouda-type cheese from cow's milk, flavored with lavender flower powder (0.5 g/L matured milk), ripened for 30 days at 14 °C and 85% relative humidity. Physicochemical, microbiological, and textural characteristics, as well as the volatile composition of the control (CC-cheese without lavender) and lavender cheese (LC), were assessed at 10-day intervals of ripening. Consumers' perception, acceptance, and purchase intention were only evaluated for ripened cheeses. Moisture and carbohydrate contents, the pH, cohesiveness, indexes of springiness and chewiness decreased during ripening in both CC and LC; however, protein, ash, and sodium chloride contents, titratable acidity, hardness, lactobacilli, streptococci, and volatiles increased. Fat and fat in dry matter contents, respectively, the energy value did not vary with ripening time in LC and increased in CC; gumminess decreased in CC and did not change in LC. Lavender flower powder significantly affected the cheese's microbiological and sensory characteristics and volatile composition but did not considerably impact physicochemical and textural ones. Populations of lactobacilli and streptococci were substantially higher in LC compared to CC. The volatile profile of LC was dominated by terpene and terpenoids, and that of CC by haloalkanes. Sensory scores were slightly lower for LC than CC, even if it did not considerably affect consumers' acceptance and purchase intention.

Biological Activity of Picrorhiza kurroa: A Source of Potential Antimicrobial Compounds against Yersinia enterocolitica

Yersiniosis, caused by Yersinia enterocolitica, is the third most rampant zoonotic disease in Europe; the pathogen shows high antibiotic resistance. Herbs have multiple anti-microbial components that reduce microorganism resistance. Therefore, an extract of Picrorhiza kurroa (P. kurroa) was evaluated for potential antimicrobial activity. We report that the ethanolic extract of P. kurroa showed effective antimicrobial activity (zone of inhibition: 29.8 mm, Minimum inhibitory concentration (MIC): 2.45 mg/mL, minimum bactericidal concentration (MBC): 2.4 mg/mL) against Yersinia enterocolitica. Potential bioactive compounds from P. kurroa were identified using LC-MS, namely, cerberidol, annonidine A, benzyl formate, picroside-1, and furcatoside A. P. kurroa showed effective antimicrobial potential in skim milk at different pH, acidity, and water activity levels. P. kurroa affected the physiology of Yersinia enterocolitica and reduced the number of live cells. Yersinia enterocolitica, when incubated with P. kurroa extract, showed lower toxin production. Picroside-1 was isolated and showed higher antimicrobial potential in comparison to the standard antibiotic. Picroside-1 lysed the Yersinia enterocolitica cells, as observed under scanning electron microscopy. Docking revealed that picroside-1 (ligand) showed both hydrophilic and hydrophobic interactions with the dihydrofolate reductase (DHFR) protein of Yersinia enterocolitica and that DHFR is a possible drug target. The high activity and natural origin of Picroside-1 justify its potential as a possible drug candidate for Yersinia enterocolitica.

Characterization of Anthocyanins and Their Antioxidant Activities in Indian Rose Varieties (Rosa × hybrida) Using HPLC

The present study was designed to explore the anthocyanin profile and antioxidant activities in Indian rose varieties (Rosa × hybrida). Among fifty varieties, Ashwini recorded the highest total phenolic content (427.59 ± 3.47 mg GAE/100 g) along with the highest FRAP (397.15 ± 0.82 µmol trolox/g) and DPPH free radical scavenging activity (93.47 ± 0.19%) on a fresh weight basis. A significant positive correlation was observed between total anthocyanin content, total phenolic content, and antioxidant activities. Four distinct clusters were formed according to total anthocyanins, total phenols, and antioxidant activities; white- and yellow-colored varieties were most distant from red ones. Principal component analysis revealed that variable total anthocyanin content contributed to the maximum variation among the fifty rose varieties studied. Highly anthocyanin-rich rose varieties were characterized by high-performance liquid chromatography coupled with a photodiode array detector (HPLC-PAD), which identified two major components of anthocyanins, i.e., cyanidin 3,5-di-O-glucoside and pelargonidin 3,5-di-O-glucoside. Cyanidin 3,5-di-O-glucoside was the predominant anthocyanin in red- and pink-colored varieties, whereas pelargonidin 3,5-di-O-glucoside was the major one in the orange variety. The maximum cyanidin 3,5-di-O-glucoside content was recorded in variety Ashwini (497.79 mg/100 g), whereas the maximum pelargonidin 3,5-di-O-glucoside content was recorded in Suryakiran (185.43 mg/100 g). It is suggested that the rose varieties with high anthocyanin content and antioxidant activity can be exploited as a potential source of nutraceuticals in the food industry.

Effect of Single and Dual Modifications on Properties of Lotus Rhizome Starch Modified by Microwave and γ-Irradiation: A Comparative Study

A comparative study between two novel starch modification technologies, i.e., microwave (MI) and γ-irradiation (IR), is of important significance for their applications. The objective of this work is to compare the changes in lotus rhizome starch (LRS) subjected to single modifications by MI (thermal treatment) and IR (non-thermal treatment), and dual modification by changing the treatment sequence, i.e., microwave followed by irradiation (MI-IR) and irradiation followed by microwave (IR-MI). The amylose content of native and modified LRS varied from 14.68 to 18.94%, the highest and lowest values found for native and MI-LRS, respectively. IR-treated LRS showed the lowest swelling power (4.13 g/g) but highest solubility (86.9%) among native and modified LRS. An increase in light transmittance value suggested a lower retrogradation rate for dual-modified starches, making them more suitable for food application at refrigeration and frozen temperatures. Dual-modified LRS showed the development of fissures and dents on the surface of granules as well as the reduction in peak intensities of OH and CH2 groups in FTIR spectra. Combined modifications (MI and IR) reduced values of pasting parameters and gelatinization properties compared to native and microwaved LRS and showed improved stability to shear thinning during cooking and thermal processing. The sequence of modification also affected the rheological properties; the G′ and G″ of MI-IR LRS were lower (357.41 Pa and 50.16 Pa, respectively) than the IR-MI sample (511.96 Pa and 70.09 Pa, respectively), giving it a soft gel texture. Nevertheless, dual modification of LRS by combining MI and IR made more significant changes in starch characteristics than single modifications.

An Update Regarding the Bioactive Compound of Cereal By-Products: Health Benefits and Potential Applications

Cereal processing generates around 12.9% of all food waste globally. Wheat bran, wheat germ, rice bran, rice germ, corn germ, corn bran, barley bran, and brewery spent grain are just a few examples of wastes that may be exploited to recover bioactive compounds. As a result, a long-term strategy for developing novel food products and ingredients is encouraged. High-value compounds like proteins, essential amino acids, essential fatty acids, ferulic acid, and other phenols, tocopherols, or β-glucans are found in cereal by-products. This review aims to provide a critical and comprehensive overview of current knowledge regarding the bioactive compounds recovered from cereal by-products, emphasizing their functional values and potential human health benefits.

Apricot Kernel: Bioactivity, Characterization, Applications, and Health Attributes

Apricot kernel, a by-product of apricot fruit, is a rich source of proteins, vitamins, and carbohydrates. Moreover, it can be used for medicinal purposes and the formation of food ingredients. Several techniques have been adopted for the extraction of bioactive compounds from the apricot kernel such as solvent extraction, ultra-sonication, enzyme-assisted, microwave-assisted, and aqueous extraction. Apricot kernels may help to fight against various diseases such as cancer and cancer immunotherapy, as well as reduce blood pressure. Additionally, the kernel is famous due to its diverse industrial applications in various industries and fields of research such as thermal energy storage, the cosmetic industry, the pharmaceutical industry, and the food industry. Especially in the food industry, the apricot kernel can be used in the preparation of low-fat biscuits, cookies, cakes, and the fabrication of antimicrobial films. Therefore, in this review article, the bioactivity of the apricot kernel is discussed along with its chemical or nutritional composition, characterizations, and applications.

Implementation of an Analytical Method for Spectrophotometric Evaluation of Total Phenolic Content in Essential Oils

Over the past decade, there has been growing interest in polyphenols’ research since these compounds, as antioxidants, have several health benefits, such as preventing neurodegenerative diseases, inflammation, cancer, cardiovascular diseases, and type 2 diabetes. This study implements an analytical method to assess the total phenolic content (TPC) in essential oils using Folin–Ciocalteu’s phenol reagent and quantifies the individual phenolic compounds by liquid chromatography. Thus, the research design and methodology included: (1) extraction of essential oil from dried thyme leaves by hydrodistillation; (2) spectrophotometric measurement of TPC by Folin–Ciocalteu method; and (3) identification and quantification of individual phenolic compounds by high-performance liquid chromatography-diode array detection/electrospray ionization mass spectrometry (HPLC-DAD-ESI-MS). Results revealed a TPC of 22.62 ± 0.482 mg GAE/100 µL and a polyphenolic profile characterized by phenolic acids (52.1%), flavonoids (16.1%), and other polyphenols (31.8%). Thymol, salvianolic acid A, and rosmarinic acid were the major compounds of thyme essential oil. The proposed analytical procedure has an acceptable level of repeatability, reproducibility, linearity, LOD (limit of detection), and LOQ (limit of quantification).

Bioactives from Mushroom: Health Attributes and Food Industry Applications

It is well-known that the utilization of mushrooms as therapeutic agents is not new. Over the past years, they have been used by local individuals as food, as well as medicines, throughout the world. Nowadays, mushrooms are excessively used in the medicine, pharmacy, food, and fermentation fields as well. Wild mushrooms are of particular interest, especially Trametes versicolor (commonly known as turkey mushrooms) due to their various uses in the food and pharmaceutical industries. They represent not only a huge storehouse of vitamins, minerals, and dietary fiber, but they are also an important source of bioactive polysaccharides. They are widely used in traditional oriental therapies. The fruiting bodies are used in the preparation of health tonics and tea. The present review is necessary to explore more about this mushroom-like classical taxonomy, morphology, nutritional value, bioactivity, various health attributes, mechanism of bioactive components against various diseases, and food applications. The influence of processing processes on the nutritional properties and bioactivity of the fungus is discussed. Potential bioactive components promising health attributes of Trametes versicolor are extensively described. Additionally, several in vivo and in vitro studies have demonstrated the beneficial effects of polysaccharopeptides (PSP) and Polysaccharide-K (PSK) on the aspects related to immune function and inflammation, also presenting an anticancerous effect. Moreover, PSP and PSK were successfully described to decrease several life-threatening diseases. The potential food applications of Trametes versicolor were detailed to signify the effective utilization of the mushroom in functional food formulation.

Reintegration of Brewers Spent Grains in the Food Chain: Nutritional, Functional and Sensorial Aspects

Nowadays, the pandemic situation has encouraged the idea of sustainable healthy foods leading to new trends in food consumption. Brewers spent grain (BSG) represents a potential functional food rich in fiber, protein, lipids, mineral and phenols that needs to be further exploited. In this vein, five different BSG types were collected from local breweries and valorized in cookies manufacturing. Thus, proximate composition (protein, minerals, lipids, ash, crude fiber and carbohydrates) was analyzed using AACC (American Association of Cereal Chemists) methods, DPPH (2,2-Diphenyl-1-picrylhydrazyl), and Folin Ciocalteu methods were used to determined antioxidant activity and total phenols, while minerals and aroma volatile compounds were performed using inductively coupled plasma optical emission spectrometry (ICP-OES) and ITEX/GC-MS (in tube extraction gas chromatography-mass spectrometry) respectively. Color and physical characteristics, together with sensorial analysis, were also evaluated. The results highlighted a significant difference between BSG samples, mainly from the total phenols, antioxidant activity and aroma volatile compounds point of view. BSG volatiles compounds from the aldehydes group such as 2-methyl-propanal, 3-methyl-butanal and 2-methyl-butanal were identified also in the final baked goods, leading to a pleasant and appreciated consumers' taste and aroma. Furthermore, cookies sensorial analysis emphasized that the sample manufactured with BSG from light and dark malt mixture was more appreciated by consumers, attaining the highest hedonic scores.

Formulation and Characterization of Antimicrobial Edible Films Based on Whey Protein Isolate and Tarragon Essential Oil

The effects of heat treatment and the addition of tarragon essential oil on physical and mechanical properties of films prepared with 5% whey protein isolate (WPI) and 5% glycerol were investigated in this study. Heat treatment of the film-forming solution caused increases in thickness, moisture content, swelling degree, water vapor permeability (WVP), b*-value, ΔE*-value, transmittance values in the 200-300-nm region, transparency, and puncture resistance of the film, but decreases in water solubility, L*-value, a*-value, transmittance values in the 350-800-nm region, and puncture deformation. When incorporated with tarragon essential oil, heat-treated films have the potential to be used as antimicrobial food packaging. The addition of tarragon essential oil in film-forming solution caused increases in moisture content, solubility in water, WVP, a*-value, b*-value, ΔE*-value, and transparency of the film; decreases in transmittance values in the range of 600-800 nm; and variations in swelling degree, L*-value, transmittance values in the range of 300-550 nm, puncture resistance, and puncture deformation. Nevertheless, different tendencies were noticed in UNT (untreated) and HT (heat-treated) films with regards to transparency, light transmittance, puncture resistance, and puncture deformation. Based on these findings, HT films show improved physical and mechanical properties and, therefore, are more suitable for food-packaging applications.

Bioactive Compounds and Volatile Profiles of Five Transylvanian Wild Edible Mushrooms

This study aimed to determine the chemical composition, fatty acids, volatile profile and phenolic compounds profiles from five wild edible mushrooms (Agaricus bisporus, Pleurotus ostreatus, Cantharellus cibarius, Boletus edulis, Lactarius piperatus) from Romania. The results indicated that the dried fruiting bodies of selected mushrooms were rich in proteins (36.24 g/100 g dw-Boletus edulis) and carbohydrates (62.45 g/100 g dw-Lactarius piperatus). 4-Hydroxybenzoic acid and cinnamic acid, were the main phenolic compound present in all selected species. Additionally, the fatty acid pattern included polyunsaturated acids in more than 60% of all fatty acids followed by monounsaturated fatty acids (30%). For the studied mushroom samples, the main volatile compounds identified by the gas chromatography-mass spectrometry were hexanal, benzaldehyde and dodecanoic acid. According to the obtained results, the fruiting bodies of selected Romanian mushrooms are a rich source of bioactive molecules indicating that they may be further exploited as functional ingredients in the composition of innovative food products.

Chemometric Comparison and Classification of Some Essential Oils Extracted from Plants Belonging to Apiaceae and Lamiaceae Families Based on Their Chemical Composition and Biological Activities

This study is focused on the comparison and classification of parsley, lovage, basil, and thyme essential oils (EOs) based on their chemical composition, total phenolic content, antioxidant and antibacterial activities by using appropriate chemometric methods: Principal component analysis (PCA) and hierarchical cluster analysis (HCA). The results showed that parsley, lovage, and thyme EOs are rich in monoterpene hydrocarbons, but basil EO is rich in oxygenated monoterpenes and phenylpropanoids, and that both PCA and HCA separated essential oils into two main groups of which one contains two sub-groups. β-Phellandrene was the major component identified in parsley and lovage EOs, estragole was the major component in basil EO, and p-cymene was the major component in thyme EO. Thyme EO showed the highest level of total phenolics, the highest antioxidant capacity, and exhibited the stronger antibacterial activity, results that were emphasized by both chemometric methods used. Among tested essential oils, the one of parsley was distinguished by a low total TPC, weak antioxidant activity, and weak antibacterial activity against S. enteritidis (ATCC 13076); lovage EO by low TPC, weak antioxidant activity, but moderate antibacterial activity; and basil EO by low TPC, moderate antioxidant activity, and weak antibacterial activity against L. monocytogenes (ATCC 19114).

Inhibition of MT1-MMP activity using functional antibody fragments selected against its hemopexin domain

The membrane associated MMP, MT1-MMP, is a critical pericellular protease involved in tumour cell invasion and angiogenesis and is highly up-regulated in numerous human cancers. It therefore represents an exciting new therapeutic cancer-specific target. We have generated recombinant human scFv antibodies against the non-catalytic, hemopexin domain of MT1-MMP that modulate its interactions with collagen. One of these is an effective inhibitor of the invasive capacity of cancer cells and of angiogenesis in model systems. This demonstrates that targeting sites outside the catalytic domain presents a potential novel approach to proteinase inhibition that could have applications in cancer therapeutics.

Cytokeratin 7 and 20 staining for the diagnosis of lung and colorectal adenocarcinoma

The origin of metastatic adenocarcinoma lesions can sometimes be difficult to diagnose. The objectives of our study were to establish the cytokeratin staining pattern of primary and metastatic lung and colorectal adenocarcinomas, and to determine if this helps to identify the site of origin of metastatic lesions. We reviewed a total of 102 tissue samples from patients in our tumour registry, with either primary or metastatic lung or colorectal adenocarcinoma. Tissue sections were stained for cytokeratin 7 and 20 and read as positive or negative for staining. Clinical and radiologic information was reviewed from computerised charts. The cytokeratin 7+/cytokeratin 20- pattern characterised 96% (29 out of 30) of primary and 95% (21 out of 22) of metastatic lung adenocarcinomas. All the primary (26), and 88% (21 out of 24) of metastatic colorectal adenocarcinomas stained cytokeratin 7-/cytokeratin 20+. Samples from a variety of metastatic sites were evaluated for cytokeratin 7 and 20 staining. Out of the 102 samples, in 95% (97 out of 102) of the cases, the cytokeratin 7 and cytokeratin 20 staining pattern characterised and differentiated between lung and colorectal adenocarcinoma. Primary and metastatic lung adenocarcinomas show a cytokeratin 7+/cytokeratin 20- staining pattern, while colorectal adenocarcinomas stain cytokeratin 7-/cytokeratin 20+. Cytokeratin staining is helpful in the diagnostic differentiation of metastatic lesions from these two common primaries, and assists in determining the site of origin of metastatic lesions.

Cytokeratin 7 and 20 staining for the diagnosis of lung and colorectal adenocarcinoma

The origin of metastatic adenocarcinoma lesions can sometimes be difficult to diagnose. The objectives of our study were to establish the cytokeratin staining pattern of primary and metastatic lung and colorectal adenocarcinomas, and to determine if this helps to identify the site of origin of metastatic lesions. We reviewed a total of 102 tissue samples from patients in our tumour registry, with either primary or metastatic lung or colorectal adenocarcinoma. Tissue sections were stained for cytokeratin 7 and 20 and read as positive or negative for staining. Clinical and radiologic information was reviewed from computerised charts. The cytokeratin 7+/cytokeratin 20- pattern characterised 96% (29 out of 30) of primary and 95% (21 out of 22) of metastatic lung adenocarcinomas. All the primary (26), and 88% (21 out of 24) of metastatic colorectal adenocarcinomas stained cytokeratin 7-/cytokeratin 20+. Samples from a variety of metastatic sites were evaluated for cytokeratin 7 and 20 staining. Out of the 102 samples, in 95% (97 out of 102) of the cases, the cytokeratin 7 and cytokeratin 20 staining pattern characterised and differentiated between lung and colorectal adenocarcinoma. Primary and metastatic lung adenocarcinomas show a cytokeratin 7+/cytokeratin 20- staining pattern, while colorectal adenocarcinomas stain cytokeratin 7-/cytokeratin 20+. Cytokeratin staining is helpful in the diagnostic differentiation of metastatic lesions from these two common primaries, and assists in determining the site of origin of metastatic lesions.

Pretargeting of bacterial endocarditis in rats with streptavidin and 111In-labeled biotin

A radioimaging approach for the detection of endocarditis has been investigated using two-step pretargeting with streptavidin and radiolabeled biotin.

METHODS

Hemodynamic alterations within the rat heart were induced by placing an in-dwelling catheter into the left ventricle through the aortic valves. The animals were subsequently infected with Staphylococcus aureus through a tail vein. After an incubation period, rats were first injected with streptavidin and, 2 h later, with 111In-labeled ethylene-diaminetetraacetic acid-biotin. Whole-body gamma camera images were taken 4-5 h postinjection of the radiolabeled biotin. Control animals consisted of catheterized but uninfected, infected but uncatheterized and normal untreated rats. As a further control, the labeled biotin was administered to a study animal without the preadministration of streptavidin.

RESULTS

Histology showed typical endocarditic changes in the hearts of study animals with massive deposition of gram-positive cocci. Catheterized but uninfected animals showed alterations corresponding to nonbacterial thrombotic endocarditis. Macroautoradiography showed accumulation of radiolabel in the endocarditic vegetations of study animals. Whole-body gamma camera images showed important cardiac uptake in 7 of 8 catheterized and infected animals and in 3 of 6 catheterized but uninfected animals. Normal rats and those infected but not catheterized showed negative results by histology, autoradiography and imaging. The percent uptake of the injected dose in the heart was 0.20 (SD = 0.13) in catheterized and infected animals, 0.12 (SD = 0.10) in catheterized but uninfected animals, 0.10 (SD = 0.04) in infected but uncatheterized animals and 0.04 (SD = 0.01) in normal control animals.

CONCLUSION

The two-step pretargeting approach using streptavidin and 111In-labeled biotin was used successfully to detect S. aureus-induced bacterial endocarditis in rats.

Effect of endogenous biotin on the applications of streptavidin and biotin in mice

The use of streptavidin-conjugated antibody to pretarget tumors in animals and patients, prior to administration of radiolabeled biotin, has provided encouraging results, in part because of the high affinity of biotin for streptavidin and the rapid whole-body clearance of biotin. However, binding of endogenous biotin to streptavidin may interfere with the clinical potential of this approach. This report evaluates the effect of endogenous biotin on an antibody-streptavidin conjugate in a mouse tumor model. Tumored nude mice were depleted of endogenous biotin by sequential intraperitoneal injections of streptavidin. The assay of serum biotin levels indicated less than 0.5 ng of biotin per mL of serum in treated mice versus 4 ng per mL in untreated animals. Flow cytometric analysis was used on single-cell suspensions of tumor from animals receiving streptavidin-conjugated IgG to detect the presence of the antibody on the cell membrane (with fluoroisothiocyanate-conjugated goat anti-mouse antibody), and to detect biotin binding sites on streptavidin (with biotin-phycoerythrin). Both treated and untreated mice demonstrated the presence of antibody on tumor cells through 48 h postadministration, but only in treated animals were biotin binding sites observed. These results in the mouse model suggest that the small concentration of streptavidin delivered to a tumor via a specific antibody may be saturated with endogenous biotin and therefore not able to be targeted subsequently with radiolabeled biotin.

Imaging osteomyelitis with streptavidin and indium-111-labeled biotin

Animal studies of infection imaging by a two-step protocol have shown that important improvements in target to nontarget ratios are possible. In this protocol, unlabeled streptavidin is administered and allowed sufficient time to accumulate in the lesion, probably by nonspecific processes, and to clear elsewhere. Thereafter, 111Inbiotin is administered. A fraction of the labeled biotin may be retained in the lesion because of biotin's high affinity for streptavidin while most of the activity is cleared through the kidneys.

METHODS

Radioscintigraphy with unlabeled streptavidin followed with 111Inlabeled biotin was performed in 15 patients with chronic osteomyelitis. As controls, each patients received either 111In-labeled biotin without the preadministration of streptavidin or 111In-labeled nonspecific IgG.

RESULTS

Regions of focal uptake were identified in all patients receiving streptavidin followed by radiolabeled biotin as early as 10 min postadministration of radioactivity, and retention of label was evident through 24 hr. Coincident regions of abnormal accumulation were apparent with 111In-IgG, but only in delayed images. Moreover, with 111In-biotin alone, without the preadministration of streptavidin, focal accumulations were detected in areas similar to that identified with the two-step protocol. Although, these observations were only in the earliest images.

CONCLUSION

The results of this preliminary clinical investigation suggest that a two-step protocol with unlabeled streptavidin and radiolabeled biotin may be an alternative for the detection of infection.

Investigations of directly labeling antibodies with rhenium-188

Methods for labeling antibodies with 99mTc cannot be used without modification for radiorhenium despite the similar chemistries, in part because of a lower redox potential of rhenium and therefore a greater tendency to reoxidize. We have investigated conditions for directly labeling B72.3 IgG with 188Re via both mercaptoethanol and stannous ion antibody reduction. The reduced 188Re was stabilized for transchelation as the glucoheptonate complex and transchelated in the presence of excess stannous ion. End points were low "non-specific" binding (i.e. labeling in the absence of antibody reduction) and increased stability to cysteine challenge. By both methods, labeling efficiencies after about 15 minutes averaged 58.77% with as little as 4% non-specific binding. Specific activities of 15 muCi/microgram was achieved after 1.5 hours. By investigating labeling condition, it was possible to improve the stability of the label on stannous ion reduced antibody such that the in vitro and in vivo properties of 188Re were largely independent of labeling method. For example, losses of 188Re due to oxidation (16%) and to cysteine (7%) during 37 degrees C serum incubations for 24 hours were identical for both methods. Furthermore, after the administration to normal mice, whole body clearance and the accumulations of 188Re at 2.5 and 24 hours in blood and in most organs were also independent of labeling method. In conclusion, two different direct labeling methods provided a 188Re-labeled antibody with identical stabilities and with in vivo properties not greatly different from that seen for the same antibody radiolabeled directly with 99mTc.

Comparative properties of a technetium-99m-labeled single-stranded natural DNA and a phosphorothioate derivative in vitro and in mice

Oligonucleotides, particularly single stranded, may ultimately be of considerable use as radiopharmaceuticals. We have compared a synthetic 22-base single-stranded phosphodiester DNA with its phosphorothioate analog after both were radiolabeled with 99mTc via the hydrazino nicotinamide chelator. Whole body clearance of the label in mice was much slower when introduced on the phosphorothioate (30% vs. 75% clearance at 6 hr) because of immediate and persistent accumulation in liver (47% vs. 2% injected dose/g at 4 hr). The label in both cases was present in urine primarily on low molecular weight catabolites. High-performance liquid chromatography analysis of 37 degrees C serum incubates showed serum protein binding of 99mTc in both cases (about 100% bound at 24 hr) but to different proteins. Different behavior with respect to protein binding was also observed in the analysis of liver and kidney homogenates: the phosphodiester label was almost quantitatively converted to lower molecular weight catabolites after only 15 min, whereas the phosphorothioate label was primarily on proteins. The rapid digestion of the phosphodiester by nucleases was not observed, probably because protein binding of the labeled oligonucleotides stabilized against degradation. Thus the phosphodiester DNA may be the preferred 99mTc-labeled oligonucleotide in certain circumstances to avoid the high and persistent liver uptake observed with the phosphorothioate DNA.

Technetium-99m labeling of DNA oligonucleotides

Single-stranded RNA and DNA oligonucleotides may be useful as radiopharmaceuticals for antisense and other in vivo applications if convenient methods for stably attaching radionuclides such as 99mTc can be developed.

METHODS

To radiolabel DNA with 99mTc, we have used the hydrazino nicotinamide (SHNH) moiety developed elsewhere. The diethylenetriaminepentacetic acid (DTPA) chelate was used to label DNA with 111In for comparison. Complementary 22-base, single-stranded oligonucleotides were obtained, each with a primary amine attached to either 3' or 5' end with a biotin moiety on the opposite end. The DNA was conjugated with SHNH by a N-hydroxysuccinimide derivative with DTPA by the cyclic anhydride.

RESULTS

Reversed-phase HPLC analysis showed that essentially complete conjugation was achieved in both cases. The purified SHNH-DNA was radiolabeled with 99mTc by transchelation from glucoheptonate at labeling efficiencies of up to 60% and DTPA-DNA with 111In acetate at up to 100% efficiency. After labeling, the ability of the DNAs to bind to streptavidin through the biotin moieties and to hybridize with their complementary DNA in saline was retained for both radiolabels as determined by size-exclusion HPLC analysis. HPLC radiochromatograms of serum incubates showed a shift to 99mTc, but not 111In, to a high molecular weight, strongly suggesting serum protein binding in the former case only. Low-molecular weight degradation products were seen with 111In, but not with 99mTc and may be related to the use of phosphodiester-linked oligonucleotides. As a further measure of label stability, the DNAS were bound to streptavidin-conjugated magnetic beads and incubated in fresh 37 degrees C human serum. Less than 4% of 99mTc and 14% of 111In was lost in 24 hr.

CONCLUSION

Amino-modified, single-stranded DNA can be stably radiolabeled with 99mTc by the SHNH moiety without loss of function.

Recombinant metallothionein-conjugated streptavidin labeled with 188Re and 99mTc

Consideration is now being given to the use of avidin (or streptavidin) and biotin for radiotherapy of tumor. Accordingly, the goal of this study was to radiolabel a mouse metallothionein-streptavidin fusion protein with 188Re and to compare its properties to those of the same fusion protein radiolabeled with 99mTc. A recombinant metallothionein-streptavidin fusion protein was radiolabeled by transchelation with 99mTc- and 188Re-glucoheptonate. Labeling efficiency, which was not optimized for either radionuclide, was approximately 60% for 99mTc and 20% for 188Re. Radiochemical purity was demonstrated by size exclusion HPLC both by nearly quantitative shifts of the 188Re label to higher molecular weight upon the addition of biotinylated antibody and by the absence of a shift with biotinsaturated 188Re-metallothionein-streptavidin. Stability of the labels in 37 degrees C serum was evaluated by comparing the HPLC radiochromatograms of serum samples both before and after the addition of biotinylated antibody. The 188Re label behaved like 99mTc in that the same peaks were evident, including one prominent peak due to labeled cysteine. Recoveries during HPLC analysis of serum samples showed that oxidation rates to perrhenate and pertechnetate were identical. However, instability to cysteine challenge was greater for 188Re; for example, the loss of label to cysteine after 24 h under one set of conditions was 41% for 188Re and 22% with 99mTc. Analysis by HPLC of liver and kidney homogenates from mice administered the labeled antibodies were qualitatively and, in large measure, quantitatively independent of label. Biodistributions at 5 h in normal mice were statistically identical between the two labels in blood and in most tissues. In conclusion, streptavidin may be radiolabeled with radiorhenium using recombinant mouse metallothionein as a bifunctional chelator, and under one set of labeling conditions at least, 188Re showed similar in vitro and in vivo behavior to that of 99mTc labeled to the same fusion protein.

Influence of endogenous biotin on the biodistribution of labelled biotin derivatives in mice

Previously, this laboratory reported that in mice pre-targeted with unlabelled streptavidin, the biodistribution of 111In administered on one biotin derivative (EB1) was superior to that of another derivative (DB2). In addition, a Scatchard analysis showed that the affinity constant of 111In-EB1 is lower by seven orders of magnitude from that of 111In-DB2. Therefore, this paper considers the role that endogenous biotin may play in these observations. Both 111In-labelled EB1 and DB2 were bound to streptavidin and incubated at 37 degrees C in mouse blood with increasing concentrations of d-biotin. As determined by Sephadex G-50 chromatography, only an 8-fold molar excess of d-biotin relative to labelled streptavidin was required to displace 90% of label in the case of EB1, whereas even a 20-fold molar excess provided no detectable displacement of DB2. That this displacement was also occurring in vivo was established in a mouse model bearing an infected thigh: increasing the serum biotin level (by intraperitoneal administration of d-biotin) had no effect on the biodistribution of 111In when administered on DB2; however, the target to non-target ratio decreased in the case of EB1. We have also observed that the biodistribution is no longer favourable when EB1 is administered radiolabelled with 99Tcm. When 111In was substituted with 99Tcm on EB1, chromatography of blood samples showed that similar displacement was occurring; however, in this case, the displaced label bound to serum proteins.(ABSTRACT TRUNCATED AT 250 WORDS)

Can a cysteine challenge assay predict the in vivo behavior of 99mTc-labeled antibodies?

Recent investigations have shown that transchelation to cysteine in a principal mode of in vivo instability of 99mTc-labeled antibodies. In this investigation, a cysteine challenge assay was used to measure the in vitro instability of 99mTc directly labeled to two IgG antibodies (B72.3 and C110) via two established direct labeling methods employing mercaptoethanol and stannous ion for antibody reduction and by a novel method using glutathione for this purpose. For both antibodies, the greatest instability to cysteine occurred with stannous ion reduction. The stability of glutathione-reduced B72.3 was indistinguishable from mercaptoethanol-reduced B72.3 whereas glutathione-reduced C110 showed stability roughly intermediate between that of the other reducing agents for this antibody. Results obtained in normal mice were in the direction predicted by the assay: for both antibodies, urinary clearance of 99mTc was fastest in mice receiving antibodies labeled via stannous ion reduction, presumably because of the increased transchelation of label to cysteine in vivo. Urinary clearance was slower and identical in mice receiving B72.3 labeled via glutathione or mercaptoethanol whereas clearance in the case of glutathione-reduced C110 was intermediate between that of the other two reducing agents. At both time points, higher radioactivity levels were observed in kidneys and lower levels in blood and most other tissues for both antibodies in the case of stannous ion reduction as expected for the label of greatest instability. In the B72.3 case, with only one exception, tissue and blood levels following administration of glutathione-reduced antibody were indistinguishable from that following administration of mercaptoethanol-reduced antibody. In the C110 case, significant differences in activity levels were observed in several tissues between glutathione- and mercaptoethanol-reduced antibodies. In conclusion, the relative in vivo behaviour of 99mTc when administered to mice while labeled to two IgG antibodies were successfully predicted based on the results of an in vitro cysteine challenge assay.

[Interleukin-6: friend or enemy? Latest findings on the clinical aspects of IL-6]

The authors summarize the recent findings obtained in the field of inflammatory cytokines with particular attention on interleukin-6 (IL-6). After a short review of the molecular biology and of the cellular effects of IL-6, the most important clinical relations of IL-6 in hepatic diseases, in non-specific inflammatory bowel diseases (Crohn's disease and ulcerative colitis) and in certain autoimmune diseases are provided. The simultaneous discussion of molecular and clinical data contribute to the understanding of pathomechanisms.

Investigations of ascorbate for direct labeling of antibodies with technetium-99m

Recently, a method for the direct labeling of antibodies with 99mTc was described in which sulfhydryls were reportedly generated by reduction of antibody disulfides with ascorbic acid. Thereafter, these proteins may be labeled at high efficiency with 99mTc following reduction of pertechnetate with dithionite. This investigation was initially conducted to evaluate the mechanism of the increased stability towards cysteine challenge reported for the label and subsequently to determine the role of ascorbate in the labeling process.

METHODS

It was possible to reproduce the reported high labeling efficiencies by increasing the dithionite concentration fivefold, presumably because of variabilities among lots of commercial sodium dithionite.

RESULTS

Despite success in labeling, it was not possible to confirm that antibody reduction followed the treatment with ascorbate. Using both Ellman's reagent and 2,2' dithiodipyridine as indicators, we were unable to detect sulfhydryls on one IgG antibody treated at ten times the suggested ascorbate-to-antibody molar ratio. It was estimated that the number of sulfhydryls generated could not have been more than 1% (dithiodipyridine) to 2% (Ellman's). Furthermore, radiolabeling efficiencies for two IgG antibodies and stabilities of the label to cysteine challenge were unchanged when the ascorbate was eliminated. The number of sulfhydryls generated by treatment of the antibody with dithionite at 1-2 times the concentration required for adequate labeling was about 1% (dithiodipyridine) to 5% (Ellman's).

CONCLUSION

For the conditions of this investigation and for the antibodies employed, ascorbate apparently played no more than a minor role at best in the labeling process. If antibody reduction occurred, this most likely was a result of residual dithionite presented to the protein along with the reduced 99mTc.

Directly and indirectly technetium-99m-labeled antibodies--a comparison of in vitro and animal in vivo properties

To investigate the in vivo and in vitro properties of 99mTc when labeled to antibodies via one direct and one indirect method, the B72.3 and C110 IgG antibodies were radiolabeled directly via stannous ion reduction and indirectly via the hydrazino nicotinamide chelator and compared in vitro and in vivo. Antibody avidity (but not immunoreactive fraction) appeared to be independent of labeling methods for both antibodies. Following stannous ion reduction, antibodies were fragmented by denaturing SDS PAGE although only slight evidence of fragmentation was found in vivo. The direct label was instable to transchelation to cysteine and glutathione in vitro and in vivo. Following intravenous administration, urinary excretion of activity was threefold greater for the direct label and was almost exclusively labeled cysteine and glutathione. Significant differences in the biodistribution of 99mTc were also observed: liver levels were lower, kidney levels were higher and clearance of label from blood and tissues was faster for the direct label. At Day 1, tumor accumulation was threefold lower for the direct label although most normal tissues were also lower. In conclusion, when labeled to two antibodies by one direct method, 99mTc is unstable towards transchelation relative to one indirect method. These relative instabilities greatly influenced the biodistributions in mice and may influence the quality of images obtained in patients.

Down-regulation of tumor necrosis factor alpha activity by acute ethanol treatment in human peripheral blood monocytes

As the most commonly used drug that can modulate both metabolic and immune pathways, ethanol is evaluated in this report as a regulator of tumor necrosis factor alpha (TNF alpha) production in human peripheral blood monocytes (M phi) in combination with a variety of stimuli. While acute ethanol treatment did not induce TNF alpha in M phi, it was a potent down-regulator of M phi TNF alpha production whether induced by the combination of interferon-gamma plus muramyl dipeptide (MDP) (P < 0.001), lipopolysaccharide (LPS) alone (P < 0.01), or interferon-gamma plus LPS. Down-regulation of M phi TNF alpha by ethanol was dose dependent and statistically significant in the biologically relevant, 25-150 mM, ethanol concentration range. We also demonstrate that these ethanol concentrations did not affect M phi viability. TNF alpha down-regulation by ethanol was most effective when ethanol was administered 4 hr prior to MDP stimulation; however, it was also effective--though to a lesser extent--if it was added at the time of MDP stimulation. Furthermore, ethanol also down-regulated TNF alpha production of the in vivo preactivated M phi of trauma patients, which produce hyperelevated levels of TNF alpha. We have previously shown that the majority of posttrauma elevated M phi TNF alpha is produced by the M phi subpopulation expressing high-affinity type I Fc gamma receptors (Fc gamma RI). When the Fc gamma RI cross-linking-stimulated M phi subpopulation was treated with acute ethanol, TNF alpha production was suppressed again both in in vivo preactivated M phi of trauma patients and in M phi of normal controls.(ABSTRACT TRUNCATED AT 250 WORDS)

Induction of transforming growth factor-beta and prostaglandin E2 production by ethanol in human monocytes

To test our hypothesis that monocytes (M phi) and their mediators are major contributors to ethanol-related immunodepression, the modulating capacity of acute ethanol treatment was assessed on the production of transforming growth factor-beta (TGF beta) and prostaglandin E2 (PGE2) by human peripheral blood M phi. We demonstrate that acute in vitro treatment of adherent M phi with either 50 or 150 mM ethanol induced a significant increase in the production of TGF beta (P < 0.045 and P < 0.001, respectively). Furthermore, M phi pretreatment with both 50 and 150 mM ethanol augmented TGF beta production in response to subsequent stimulation with the synthetic bacterial analog, muramyl dipeptide (MDP) (P < 0.05 and P < 0.001, respectively). Ethanol also increased TGF beta production in interferon gamma (IFN gamma-activated M phi in response to MDP stimulus (P < 0.05). M phi TGF beta levels, however, were always lower in IFN gamma-activated than in non-IFN gamma-activated M phi after the same stimulation with ethanol plus MDP, suggesting that M phi preactivation by IFN gamma can partially counteract the TGF beta inducing potential of ethanol. Similar to its TGF beta-inducing potential, ethanol (150 mM) had the capacity to induce PGE2 production in adherent human M phi (P < 0.045). However, ethanol failed to augment M phi PGE2 production induced by the PGE2 secretagogue, MDP. TGF beta induction by ethanol was unaffected by the presence of cyclooxygenase inhibitor, suggesting that ethanol-induced M phi TGF beta production does not require M phi PGE2 production. These results indicate that ethanol is a potent inducer for inhibitory M phi mediators, TGF beta and PGE2, and also has the capacity to augment M phi TGF beta production in response to subsequent stimulation. Thus, ethanol-induced elevation of M phi TGF beta and PGE2 production might contribute to decreased T cell proliferation and abnormal M phi functions after alcohol exposure, resulting in a depressed immune response.