Serologic assays for influenza surveillance, diagnosis and vaccine evaluation.

Serological techniques play a critical role in various aspects of influenza surveillance, vaccine development and evaluation, and sometimes in diagnosis, particularly for novel influenza virus infections of humans. Because individuals are repeatedly exposed to antigenically and genetically diverse influenza viruses over a lifetime, the gold standard for detection of a recent influenza virus infection or response to current vaccination is the demonstration of a seroconversion, a fourfold or greater rise in antibody titer relative to a baseline sample, to a circulating influenza strain or vaccine component. The hemagglutination-inhibition assay remains the most widely used assay to detect strain-specific serum antibodies to influenza. The hemagglutination-inhibition assay is also used to monitor antigenic changes among influenza viruses which are constantly evolving; such antigenic data is essential for consideration of changes in influenza vaccine composition. The use of the hemagglutinin-specific microneutralization assay has increased, in part, owing to its sensitivity for detection of human antibodies to novel influenza viruses of animal origin. Neutralization assays using replication-incompetent pseudotyped particles may be advantageous in some laboratory settings for detection of antibodies to influenza viruses with heightened biocontainment requirements. The use of standardized protocols and antibody standards are important steps to improve reproducibility and interlaboratory comparability of results of serologic assays for influenza viruses.

Hemagglutinins in vegetative tissues of Bengal gram.

Hemagglutinating activity was identified in the roots and vegetative tissues of Bengal gram using rabbit erythrocytes. The activity in the roots appears to be similar to that of the seeds in respect to their sugar inhibition property. Seed and root extracts were found to have fetuin inhibitory agglutinating activity, whereas cotyledons showed different sugar specificity. However, 7-day cotyledons and roots from 3 and 7-day plants were also found to have galactose and N-acetyl-D-galactosamine inhibitory activity. Protein profile in different tissues during their developmental stages was analyzed by SDS-PAGE. A major band at 66 kDa was common to all tissues at different stages of their development except 3-day cotyledons where 2 major bands at 22 kDa and 74 kDa were observed. Two prominent bands at 74 kDa and 86 kDa were found along with 60 kDa protein in 3-day old roots whereas a major band at 33 kDa was found in 15-day old roots. Total protein content and specific activity of hemagglutinin were measured. Increase in specific activity with lower protein content was observed in cotyledons of 15-day old plant. Specific activity was eight times higher in the roots and four times more in leaf tissues of 7-day old plants in comparison to 15-day old plants. Stems also showed a significant increase of specific activity (p = 0.013) in 7-day old plants without any significant alteration in the protein content.

Immunostimulant activity of dry fruits and plant materials used in indian traditional medical system for mothers after child birth and invalids.

Products of certain plants given to mothers after child birth or to invalids were studied for immunostimulant activity using the macrophage migration index (MMI) as a parameter of macrophage activation and cell-mediated immunity and haemagglutinating antibody (HA) titres and plaque-forming cell (PFC) counts as parameters of humoral immunity. Feeding of Prunus amygdalus (Almond(1)) and Buchanania lanzan (Chirronji(1)) significantly stimulated both CMI and humoral immunity in BALB/c mice as evidenced by the enhancement of MMI, HA titres, and PFC counts. Euryale ferox (Tel makhana(1)), Phoenix dactylifera (Chhohara(1)) and Zingiber officinale (Sonth(1)), however, stimulated humoral immunity to a greater extent than CMI. The observation provides scientific basis for feeding the products of above plants to mothers after child birth and to invalids with a relatively poor immune status.

Impact of microwave heating on hemagglutinins, trypsin inhibitors and protein quality of selected legume seeds.

Selected legume seeds (dry and soaked) including faba beans, peas, chickpeas, soybeans, lentils and common beans containing 8 and 25% moisture, respectively, were subjected to microwave heating, and to a conventional cooking method to determine the heating effect on toxic compounds and protein quality. Trypsin inhibitors, hemagglutinins and available lysine were analyzed, and laboratory rats were used to determine digestibility and protein efficiency ratio (PER). Results indicated that microwaving destroyed trypsin inhibitors to a similar degree to that observed in beans cooked using the conventional method without affecting PER for raw seeds with low antinutrients content (faba beans, peas, chickpeas and lentils). Microwave-heated soaked soybeans had a higher amount of destroyed trypsin inhibitors, along with a higher PER, compared with microwave-heated dry soybeans. Microwave heating of common beans failed to destroy hemagglutinins and trypsin inhibitors, and consequently their digestibility and PER values were poor. Finally it was concluded that microwave heating constitutes an adequate method for destroying hemagglutinins and trypsin inhibitors without affecting protein quality of most legume seeds, except for common beans that despite of this process retained the antinutritional substances.

Composition and functional properties of protein isolates obtained from commercial legumes grown in northern Spain.

Pea (Pisum sativum), faba bean (Vicia faba) and soybean (Glycine max) seeds were characterized, and protein isolates were prepared following an isoelectric point precipitation procedure. Soybean seeds showed the highest protein content (36.7%) and carbohydrate was the major constituent in the pea (59.4%) and the faba bean seeds (52.1%). Protein contents were higher than 80% in all the protein isolates. The amino acid contents in the protein isolates were, in general, higher than those in their own starting seeds. The antinutritional factor contents were reduced after the protein isolate preparation. The highest reductions achieved for tannins were 95% in the faba bean protein isolate, and for phytates (45%) and trypsin inhibitor activity (46%) in the pea protein isolate. Haemagglutinating activity was not detected in any of the protein isolates. Minimum solubility values were observed at a pH range between 4.0 and 6.0, and maximal solubilities were obtained at basic pH values. The faba bean protein isolate showed the highest water and oil absorption capacities, and the best gelling properties. The soybean protein isolate had the best foam expansion capacity. Thus, the protein isolates had an improvement in some of the characteristics compared to their original seeds with lower contents in tannins, phytates and haemagglutinating activity, but had weak functional properties.

Protein quality of raw and autoclaved cowpeas: comparison between some insect resistant and susceptible varieties.

A comparative study was conducted with four improved cowpea (2 pod bug resistant and 2 susceptible) varieties to assess the effect of autoclaving at 105 degrees C under 15 psi for 30 min on their protein quality, as measured by the levels of some antinutritional factors and performance of rats fed the different cowpea diets. Also, the relationships between antinutrients in the cowpeas and protein quality indicators were examined. Results showed that autoclaving completely eliminated trypsin inhibitor, hemagglutinin and HCN, whereas it reduced significantly (p < 0.01) the levels of phytic and tannic acids in the cowpeas. In both raw and autoclaved forms, the insect susceptible cowpeas were better (p < 0.05) utilized than their resistant counterparts, a condition which was attributable to lower levels of antinutrients in the susceptible varieties. In the raw cowpeas, trypsin inhibitor, hemagglutinin and HCN were significant variables affecting cowpea protein utilization, while in autoclaved samples, tannic and phytic acids were important though nonsignificant (p > 0.05) factors. It was concluded that autoclaving at the above temperature and time improved the protein quality of the insect susceptible more than the insect resistant cowpea varieties.

Effects of processing and in vitro proteolytic digestion on soybean and yambean hemagglutinins.

Some conventional processing methods were applied on yambean and soybean seeds and flour samples. They include soaking fermentation, cooking whole seeds in the presence and absence of trona, autoclaving and dry heat treatment of flour samples. Hemagglutinating activity was assayed for after processing treatments. The hemagglutinating proteins from these seeds were classified based on their solubility properties. Effects of the presence of 0.01% concentration of trypsin, pepsin and proteases on agglutination of human red blood cells were also evaluated. Most processing methods, particularly cooking whole seeds for 1-2 h, soaking and fermentation, reduced hemagglutinating activity on cow red blood cells. Size reduction accompanied by heat treatment was effective in eliminating hemagglutination. Both the albumin and globulin fractions of the soybean showed hemagglutinating activity but only the albumin fraction of the yambean had agglutinating properties. Proteolytic action of proteases was more effective in reduction of hemagglutinating activity than that of trypsin and pepsin.

Comparative study of the chemical composition of wild and cultivated beans (Phaseolus vulgaris).

Five wild Phaseolus vulgaris beans were compared with five cultivated Phaseolus vulgaris beans in proximate composition, total (true) protein, amino acid composition, and toxic and antinutritional factors. The wild beans contained more protein (25.5% vs. 21.7%), ash (5.15 vs. 4.15%), crude fiber (7.08% vs. 5.04%) compared to cultivated beans while the former contained less fat (0.56 vs. 0.89%) and carbohydrates (61.64 vs. 68.05%). Sulfur amino acids were found to be limiting in both groups of bean as expected; however, the cultivated beans had a higher content of the limiting amino acids. Therefore, the cultivated beans showed a better amino acid profile than the wild beans. Toxic factors were not found in either type of bean; the determinations included saponins, alkaloids, and cyanogenic glycosides. The antinutritional factors investigated were hemagglutinins (lectins) and trypsin inhibitors. The wild beans presented a higher content of trypsin inhibitors (28 TUI per mg) and lectins (9.6) than the cultivated beans did (21 TUI per mg and 7 respectively). From the chemical point of view, domestication seems to be positive; however, the better protein nutritive quality of the cultivated beans should be further confirmed by biological assays.

Effect of thermal treatments on the chemical and biological value of irradiated and non-irradiated cowpea bean (Vigna unguiculata L. Walp) flour.

Chemical and nutritional characteristics of irradiated and nonirradiated cowpea bean at 0.2 kGy submitted to several thermal treatments were studied. The cowpea bean flours irradiated at 0.2 kGy were superior to those non-irradiated concerning digestibility and the flours submitted to microwave oven were superior to those cooked under low pressure, autoclaved or even raw from the nutritional point of view. As to the presence of anti-nutritional factors, the results showed that the variety of cowpea bean under research presented neither trypsin inhibitor nor haemagglutinin activity, however, regarding tannin, a 0.006% content was found and considered negligible.

A high alpha-linolenate diet suppresses antigen-induced immunoglobulin E response and anaphylactic shock in mice.

Mice were fed for 2 mo diets having ratios of alpha-linolenate [18:3 (n-3)] to linoleate [18:2(n-6)] of < 0.01, 0.36, 1.0 and 3.9. Proportions of safflower seed oil and perilla seed oil were adjusted to obtain these ratios. The dietary alpha-linolenate to linoleate balance was reflected in the proportion of (n-3) and (n-6) highly unsaturated fatty acids with 20- and 22-carbon chains in spleen phospholipids, but the ratio did not affect the proportion of T lymphocyte subsets expressing CD4 and CD8 antigens in splenic leukocytes. The immunoglobulin (Ig) G and IgM responses against sheep red blood cells when estimated as plaque-forming cells present in spleen, were not affected significantly by the diets. However, the serum hemagglutinin titer was slightly but significantly higher in the high alpha-linolenate diet group [18:3(n-3)/18:2(n-6) = 3.9] than in the dietary group with 18:3(n-3) to 18:2(n-6) ratios of 0.36 and < 0.01. In contrast, the IgE antibody response against egg albumin, as well as the mortality from anaphylactic shock induced by a second challenge with antigen, was significantly lower in the high alpha-linolenate diet group [18:3(n-3)/18:2(n-6) = 3.9] than in the high linoleate diet [18:3(n-3)/18:2(n-6) < 0.01] group. These results, together with the reported suppressive effects of a high alpha-linolenate diet on the formation of lipid-derived allergic mediators, support the hypothesis that raising the (n-3) to (n-6) ratios of diets would be effective in reducing the severity of immediate-type allergic hypersensitivity.

[Chemical composition of 6 unconventional plants from Oaxaca State, Mexico, as potential resources for animal feed]. / Estudio de la composición química de 6 plantas no convencionales del Estado de Oaxaca, México, como recursos potenciales en la alimentación animal.

Characteristics and distribution of six plants are described. The chemical composition and in vitro digestibility of leaf and stem of Polymnia maculata, Trigonospermum annuum, Buddleia parviflora Kunt, Canna indica L, Gnaphalium oxyphyllum y Saurauia scabrida Hensl., selected for farmers information, were analysed as a potential resources in animal feeding. The results in dry matter: Crude protein (%): Go and Ss 10.9, Bp 16.7, Pm 11.7 and Ta 11.3. Cell wall (%): Go 54.1, Ss 52.3, Ci 54.4, Bp 68.3, Pm 27.8 and Ta 30.9. Lignin (%): Go and Ss 16.6, Ci 15.5, Bp 10.4, Pm 10.6 and Ta 13.3. IN vitro dry matter digestibility (%): Go 55.1, Ss 37.6, Ci 55.4, Bp 46.5, Pm 82.4 and Ta 81.4. Calcium and phosphorus (mg/100g) respectively: Go 1095 and 379, Ss 1132 and 387, Ci 600 and 421, Bp 800 and 855, Pm 1146 and 421 and Ta 905 and 480. Tannic acid (mg/100g): Go 1450, Ss 1480, Bp 575, Ci 518, Pm 3329 and Ta 2760. Trypsin inhibitor (UIT/g): Go 22264, Ss 29720, Bp 755, Ci 4228, Pm 931 and Ta 4412. Hemagglutinins were detected in Pm and Ta. Alkaloids were detected as scarce in Bp, Ci and Pm, moderate in Ta. Saponins and Cyanogenic glucosides were not detected. It is concluded that Pm and Ta could be considered as a forage for ruminants; Go, Bp and Ci as a complement; recommended the voluntary intake, in vivo digestibility and weight increase trials.

[Effects of traditional cooking on antinutritional factors of the black beans (Phaseolus vulgaris) of Costa Rica]. / Efectos de la cocción tradicional sobre los factores antinutricionales de los frijoles negros (Phaseolus vulgaris) de Costa Rica.

Trypsin inhibitors, alfa amylase inhibitors and hemagglutinins were determined in black beans (P. vulgaris) produced in Costa Rica. The effect of the traditional cooking on such antinutritional factors was also studied. The antinutritional factors were analyzed spectrophotometrically in the raw beans, as well as after several cooking periods of time. The results showed that alfa-amylase inhibitors were the most thermoresistant. After 30 min of cooking time there was a 33% of activity left from the initial activity of the raw beans. Approximately 80% of the antitryptic activity was destroyed at 9 min of cooking time. After 10 min of cooking time, only 1% of hemagglutinin activity was present.

The effect of the consumption of red kidney beans (Phaseolus vulgaris) on the growth of rats and the implications for human populations.

Raw Red Kidney beans (Phaseolus vulgaris) at a level as low as 1% of diet have been shown to cause death in rats in two weeks. Beans cooked at 100 degrees for 30 mins, and incorporated at a level as high as 20% of diet do not retard growth when tested against casein. However, when beans which have cooked at 70 degrees for 30 mins are incorporated growth retardation is almost as great as that which occurs when raw beans are fed. The small amount of lectin present in beans cooked at 70 degrees might be responsible for this effect.

Red kidney bean poisoning in the UK: an analysis of 50 suspected incidents between 1976 and 1989.

Between July 1976 and February 1989, 50 incidents of suspected red kidney bean poisoning were reported in the UK. Nine incidents in which nausea, vomiting and diarrhoea developed within 1-7 h of ingestion, were confirmed by the detection of haemagglutinin in the beans. The diagnosis was made on a further 23 incidents on the basis of symptoms, incubation time and the description of preparation of beans prior to consumption. The haemagglutinin (lectin), which occurs naturally in the red kidney bean, is inactivated by thorough cooking of well soaked beans. In many of the outbreaks reported the implicated beans were consumed raw or following an inadequate heat process.

Changes in differently processed soya bean (Glycine max.) and lima bean (Phaseolus lunatus) with particular reference to their chemical composition and their mineral and some inherent anti-nutritional constituents.

The effects of 3 processing techniques: cooking, roasting and autoclaving on the proximate chemical composition, the mineral content and some inherent toxic factors of soya and lima beans were investigated. The processing techniques generally reduced the crude fibre levels and enhanced the extractable fat in the soya and lima beans. The coefficients of variability for crude fibre and ether extract due to the processing techniques of soya and lima beans were 20.9%, 16.0% and 22.3%, 38.1%, respectively. In parallel with decreased ash content in the cooked bean samples, there was a decrease in the K, Mg, Na and P levels relative to the raw bean and also relative to the other processing techniques. Mineral contents of the autoclaved bean samples were generally similar to those of the raw (unprocessed) samples. Under the processing conditions, roasting caused the highest reduction in thioglucoside content (59%) in soya bean while cooking caused the highest reduction in lima bean (78%). Trypsin inhibitor activity (TIA) ranged between 0.59 mg/g sample in the cooked soya bean and 11.6 mg/g sample in the raw bean while the corresponding values for lima bean ranged between 0.59 and 6.3 mg/g sample. Cooking and roasting caused over 90% reduction of TIA, while autoclaving caused 64-69% reduction in both bean samples. Under the assay conditions, haemagglutinating activity was not detected in the cooked and autoclaved soya and lima beans. The need to prevent both functional and nutritional damage to food proteins and other nutrients, resulting from excessive heating, was discussed.

Compositional evaluation of some cowpea varieties and some under-utilized edible legumes in Nigeria.

The nutritive potentials of some cowpea varieties such as Ife Brown, Ife Bimpe, IT84E-124, K59 and TVX716 and some under-utilized edible legumes grown in Nigeria such as pigeon pea (Cajanus cajan), lima bean (Phaseolus lunatus), lablab bean (Dolichos lablab), mucuna bean (Mucuna sp.) and Sphenostilis sternocarpa have been evaluated with respect to their proximate chemical composition, mineral content and some endogenous toxic constituents. The cowpea varieties contained on the average 22.5 g crude protein (CP), 2.60 g crude fibre (CF), 5.89 g either extract (EE) and 3.36 g ash/100 g DM while the under-utilized legumes contained 21.7, 6.10, 2.86, and 3.56 g/100 g DM for CP, CF, EE and ash respectively. Distinct varietal differences were observed for EE values as indicated by the coefficients of variation (CV) of 102% for cowpea and 60.8% for the under-utilized legumes. The CF content of the under-utilized legumes were generally higher than those of the cowpea varieties. Potassium was the most abundant mineral in both the cowpea varieties and the under-utilized legumes with mean values of 1.45 and 1.66% respectively, while P was the least abundant with 13.1 and 8.50 ppm, respectively. There were marked intra-varietal differences in the P content as shown by the high CV of 84.0 and 73.9% for the cowpea varieties and the other legumes. The cowpea varieties generally had higher levels of thioglucosides, trypsin inhibitor activity (TIA) and lower haemagglutinating activity (mean values of thioglucosides: 3.86%, of TIA: 13.9 mg/g protein and of haemagglutinating activity: 13.0 HU/mg N respectively), than the under-utilized legumes with mean respective values of 1.22%, 9.84 mg/g protein and 22.7 HU/mg N. The nutritional implications of these anti-nutritional components were discussed and some reasons adduced for the under-utilization of some of these legumes inspite of their apparent similarity in nutritional quality to the more commonly consumed grain legumes.

[Ability of amino acid components of proteins to stimulate the thymus-dependent immune response]. / Sposobnost' nekotorykh aminokislot, vkhodiashchikh v sostav belka, stimulirovat' timuszavisimyi immunnyi otvet.

The ability of protein amino acids to facilitate differentiation of mouse bone marrow cells into T lymphocytes in vitro and to stimulate primary immune response to sheep red blood cells in vivo was studied. Nine out of twenty amino acids (aspartic acid, asparagine, glutaminic acid, cysteine, serine, threonine, tryptophan, alanine and valine) were shown to possess immunologic activity, with the highest activity revealed in aspartic acid.

[Chemical composition and evaluation of the protein quality of beans in adult humans by the short-term nitrogen balance method]. / Composición química y evaluación de la calidad de la proteína del frijol en humanos adultos por el método de balance nitrogenado de corto tiempo]

Three varieties of common beans were chemically analyzed and their protein quality was evaluated in 12 human male adult subjects by the short-term nitrogen balance method. Chemical analyses were performed for both raw and cooked grains. Cooking reduced the trypsin inhibitors in 28 to 73%, hemagglutinins, 100%, tannins as acid tannic equivalents, 9 to 72%, and 55 to 75% as catequin equivalents, and alkali-soluble nitrogen in 65%. Red and black beans contained more residual trypsin inhibitors and tannins than white beans, while the latter contained more alkali-soluble nitrogen. Although cooked colored beans had more antinutritional factors that affect protein digestibility, their protein quality was similar to that of white beans. This could be explained by the fact that the amino acid composition and/or balance of red and black beans absorbed nitrogen is better than that of white beans, so that the final nutritional value will be determined by the sum of interactions between all factors. In this study, each of the three varieties presented at least one protein quality depressor in higher concentration than the other two varieties. Therefore, the overall differences found between treatments and residual effect, were small or non existent, while significant differences (p greater than 0.05) were found between subjects and nitrogen balance periods. A level of 0.65 g of bean protein/kg/day was not enough to maintain nitrogen balance in subjects fed a diet where beans were the only protein source. According to calculations, 0.9-1.0 g of bean protein/kg/day are necessary for nitrogen balance in male adults, and 1.2-1.3 g of protein bean would be the recommendation for a normal population.

Studies of the combined use of steroid and Shosaikoto, one of the Kampohozai (Chinese traditional medicine), on pituitary adrenocortical axis function and immune responses.

The combined effects of Shosaikoto, one of the Kampohozai (Chinese traditional medicine), and prednisolone were examined for suppressive actions on pituitary adrenocortical axis function and immune response induced by prednisolone using rats and mice. The administration of Shosaikoto, 1.2 g/kg p.o., for 45 d showed a tendency to increase adrenal weight. By the combined use of Shosaikoto, 0.12 and 1.2 g/kg p.o., and prednisolone, 0.016 g/kg p.o., for 45 d, the decrease of adrenal weight induced by the treatment with prednisolone was restored. The administration of Shosaikoto, 1.2 g/kg p.o., elevated the blood corticosterone level. In the case of combined use, Shosaikoto, 0.12 and 1.2 g/kg p.o., inhibited the decrease of blood corticosterone level induced by the treatment with prednisolone, 0.004 g/kg p.o., and Shosaikoto, 1.2 g/kg p.o., inhibited the decrease of blood corticosterone level induced by the treatment with prednisolone, 0.016 g/kg p.o. On the other hand, the administration of Shosaikoto, 1.2 g/kg p.o., for 7 d reduced the number of hemolytic plaque forming cells (HPFC) in spleen cells. But, Shosaikoto, 1.2 g/kg p.o., administered for 7 d inhibited the decrease of the number of HPFC induced by the treatment with prednisolone, 0.01 and 0.03 g/kg s.c., for 3 d. Furthermore, Shosaikoto, 1.2 g/kg p.o., restored the number of rosette forming cell (RFC) which decreased by prednisolone, 0.03 g/kg s.c. The decrease of 7S HA titer of the serum by the treatment with prednisolone, 0.01 g/kg s.c., was also inhibited by the combination with Shosaikoto, 1.2 g/kg p.o.