Probing Flat Band Physics in Spin Ice Systems via Polarized Neutron Scattering.

In this Letter, we illustrate how polarized neutron scattering can be used to isolate the spin-spin correlations of modes forming flat bands in a frustrated magnetic system hosting a classical spin liquid phase. In particular, we explain why the nearest-neighbor spin ice model, whose interaction matrix has two flat bands, produces a dispersionless (i.e., "flat") response in the non-spin-flip (NSF) polarized neutron scattering channel and demonstrate that NSF scattering is a highly sensitive probe of correlations induced by weak perturbations that lift the flat band degeneracy. We use this to explain the experimentally measured dispersive (i.e., nonflat) NSF channel of the dipolar spin ice compound Ho_{2}Ti_{2}O_{7}.

The performance of routine computed tomography for the detection of colorectal cancer.

INTRODUCTION: Although colonoscopy and computed tomography (CT) colonography in expert hands are the most sensitive investigations for colorectal cancer, some patients may not tolerate the necessary bowel preparation and insufflation of gas into the colon. We assessed the performance of unprepared contrast CT for the detection of colorectal cancer. METHODS: A retrospective review was undertaken of all patients who had contrast CT of the abdomen and pelvis and then went on to have colonoscopy at our institutions between 2007 and 2010. RESULTS: Overall, 96 patients were identified as having had CT prior to colonoscopy. The sensitivity of CT in detecting colorectal cancer was 100% (95% confidence interval [CI]: 19.8-100%) and the specificity was 95.7% (95% CI: 88.8-98.6%). The positive predictive value was 33.3% (95% CI: 6.0-75.9%) and the negative predictive value was 100% (95% CI: 94.8-100%). CONCLUSIONS: Non-targeted CT that is negative for colorectal malignancy is usually reassuring but the decision for further investigations should be made on a case-by-case basis, taking into account of the likelihood of underlying colorectal malignancy and the underlying co-morbidities of the patient. However, video colonoscopy is usually necessary to assess positive CT findings.

Regulation of gene expression by the NSP1 and NSP3 non-structural proteins of rotavirus.

The role of the rotavirus non-structural proteins NSP1 and NSP3 in regulating cellular and viral mRNA translation has been investigated by examining the effect of added recombinant NSP3 on protein translation in a T7-based in vitro coupled transcription-translation system. Addition of purified NSP3 to assays primed solely with cellular mRNA was found to have no effect on the translation efficiency of the mRNA. However, as expected, the addition of viral mRNA to such assays competitively inhibited the synthesis of cellular protein, and interestingly, this inhibition was enhanced by the addition of NSP3. Treatment of NSP3 with antisera raised against the purified protein abrogated its function, but only when used prior to mixing the protein with viral mRNA. Addition of partially purified NSP1 to the coupled system was able to alleviate the enhancement of the inhibition of cellular mRNA translation caused by NSP3. The role of NSP1 in this process appears to be to modulate the impact of the NSP3-based inhibition of cellular translation by binding to the 5' end of viral mRNAs.

Cocaine increases endoplasmic reticulum stress protein expression in striatal neurons.

Cocaine administration upregulates the levels of extracellular glutamate and dopamine in the striatum. Activation of the receptors alters calcium homeostasis in striatal neurons leading to the expression of the endoplasmic reticulum (ER) stress proteins. It was therefore hypothesized that cocaine upregulates the expression of the ER stress proteins, immunoglobulin heavy chain binding protein (BiP), Ire1alpha and perk via glutamate and dopamine receptor activation. A novel glutamate microbiosensor and Western immunoblot analyses were mainly performed to test the hypothesis in the rat dorsal striatum. The results showed that i.p. injection of repeated cocaine (20 mg/kg) for nine consecutive days significantly increased extracellular glutamate levels while acute cocaine injection did not. However, the immunoreactivities (IR) of the ER stress proteins in the dorsal striatum were significantly increased by either acute or repeated cocaine injections as compared with saline controls. Intrastriatal injection (i.s.) of the selective group I metabotropic glutamate receptor (mGluR) antagonist N-phenyl-7-(hydroxyimino)cyclopropa[b]chromen-1a-carboxamide (PHCCC; 25 nmol) or the mGluR5 subtype antagonist 2-methyl-6-(phenylethynyl)pyridine hydrochloride (MPEP; 2 and 25 nmol) significantly decreased repeated cocaine-induced increases in the IR of the ER stress proteins in the injected dorsal striatum. Similarly, the selective D1 antagonist (R)-(+)-7-chloro-8-hydroxy-3-methyl-1-phenyl-2,3,4,5-tetrahydro-1H-3-benzazepine hydrochloride (SCH23390; 0.1 mg/kg, i.p.) or the N-methyl-d-aspartate antagonist dizocilpine/(5S,10R)-(+)-5-methyl-10,11-dihydro-5H-ibenzo[a,d]cyclohepten-5,10-imine maleate (MK801; 2 nmol, i.s.) decreased acute or repeated cocaine-induced the IR of the ER stress proteins in the dorsal striatum. These data suggest that cocaine upregulates expression of the ER stress proteins in striatal neurons via a mechanism involving activation of glutamate and dopamine receptors.

Growth inhibition of intestinal bacteria and mutagenicity of 2-, 3-, 4-aminobiphenyls, benzidine, and biphenyl.

2-Aminobiphenyl (2-ABP), 3-aminobiphenyl (3-ABP) and 4-aminobiphenyl (4-ABP), but not benzidine (Bz) and biphenyl (Bp), were found to be inhibitory to the growth of human intestinal bacteria Bifidobacterium infantis ATCC 15697, B. bifidium ATCC 11863, Clostridium perfringens ATCC 13124, Escherichia coli ATCC 25922, E. coli ATCC 35218, Enterobacter cloacae ATCC 13047 and Salmonella typhimurium TA98, TA100, YG1041 at 10-200 microg/ml in culture broth. Bacteroides distasonis ATCC 8503, B. fragilis ATCC 25285, B. theataiotaomicron ATCC 29741, C. paraputrificum ATCC 26780, C. clostridiiforme ATCC 25537, Lactobacillus acidophilus ATCC 4356 and Enterococcus faecium ATCC 19434 were not inhibited by the above mentioned compounds in concentrations up to 200 microg/ml. The Ames Salmonella/microsome assay was employed to test the mutagenicity of the above-mentioned compounds using strains TA98 and TA100 in the presence and absence of Aroclor 1254-induced rat S9 mix. It was found that 4-ABP was mutagenic to both TA98 and TA100, and Bz was mutagenic to TA98 in the presence of rat S9 mix. 2-Aminobiphenyl, 3-ABP, and Bp were not mutagenic to both strains tested. 2-Aminobiphenyl and 3-ABP are chemical isomers of 4-ABP and are as strong as 4-ABP in inhibiting the growth of intestinal bacteria but not as mutagenic as 4-ABP. Evidence suggested that the mechanism of growth inhibition is not involved with the interaction of DNA that causes mutations, but rather on the electron transport system of these organisms.

Using base-specific Salmonella tester strains to characterize the types of mutation induced by benzidine and benzidine congeners after reductive metabolism.

Although benzidine (Bz), 4-aminobiphenyl (ABP), 3,3'-dichlorobenzidine HCl (DCBz), 3,3'-dimethylbenzidine (DMBz), 3,3'-dimethoxybenzidine (DMOBz) and the benzidine congener-based dye trypan blue (TB) produce primarily frameshift mutations in Salmonella typhimurium, the base-substitution strain TA100 also responds to these compounds when S9 is present. Performing DNA sequence analysis, other investigators have shown that ABP induces frameshift, base-pair and complex mutations. Also, it was found that an uninduced hamster liver S9 preparation with glucose-6-phosphate dehydrogenase, FMN, NADH and four times glucose 6-phosphate gave a stronger mutagenic response than the conventional plate incorporation with rat S9 activation mixture for all the compounds tested. Using the base-specific tester strains of S. typhimurium (TA7001-TA7006) with the above reductive metabolic activation system, we surveyed these compounds for the ability to produce specific base-pair substitutions after reductive metabolism. Bz was weakly mutagenic in TA7005 (0.04 revertants/microg). ABP was mutagenic in TA7002 (1.4 revertants/microg), TA7004 (0.6 revertants/microg), TA7005 (2.98 revertants/microg) and TA7006 (0.4 revertants/microg). DCBz was weakly mutagenic in TA7004 (0.01 revertants/microg). It was concluded that benzidine induced some CG->AT transversions in addition to frameshift mutations. ABP induced TA->AT, CG->AT, and CG->GC transversions as well as GC->AT transitions. DCBz induced only GC->AT transitions. Because DMBz, DMOBz and TB were not mutagenic in this base-substitution mutagen detection system, their mutagenic activity was attributed strictly to frameshift mechanisms.

Albert Léon Charles Calmette (1863-1933) and the antituberculous BCG vaccination.

Albert Léon Charles Calmette was the first person to develop an anti-venom serum. His work revolutionized the treatment of snakebite in men and domestic animals. He is also well known for his development of the Bacillus Calmette-Guérin (BCG) vaccine for the prevention of tuberculosis. This article reviews the life experiences of this pioneer bioscientist, the current status of BCG in preventing tuberculosis, and the potential of BCG in immunotherapy for cancer.

Response of the ascorbate-peroxidase of Selenastrum capricornutum to copper and lead in stormwaters.

The green alga Selenastrum capricornutum expresses a unique ascorbate peroxidase, that responds to copper and lead. Attempts were made to test if this peroxidase could be used to monitor the levels of copper and lead in natural waters. When S. capricornutum was exposed to a stormwater sample, the specific activity of the peroxidase in the cell extract was commensurate with the combined copper and lead contents in the sample. The peroxidase responses were also correlated with the 96 hr biomass toxicity assay of S. capricornutum. However, unlike the biomass toxicity assay, the peroxidase activity was not affected by the anions in the samples. The use of this peroxidase can be used as a marker for testing heavy metal toxicity in the water.

Mutagenicity studies of benzidine and its analogs: structure-activity relationships.

The Ames Salmonella/microsome assay was employed to test the mutagenicity of benzidine and its analogs using strains TA98 and TA100 in the presence and absence of Aroclor 1254-induced rat S9 mix. 3,3'-Dichlorobenzidine-2HCl and 4,4'-dinitro-2-biphenylamine were directly mutagenic to TA98, while 4,4'-dinitro-2-biphenylamine was directly mutagenic to both TA98 and TA100 in the absence of S9 mix. 2-Aminobiphenyl, 3-aminobiphenyl, and 3,3'-5,5'-tetramethylbenzidine were not mutagenic in either strains in the presence or absence of S9. In the presence of S9 mix, 4-aminobiphenyl, benzidine, 3, 3'-dichlorobenzidine-2HCl, 3,3'-dimethoxybenzidine, 3,3'-4, 4'-tetraaminobiphenyl, o-tolidine, N, N-N', N'-tetramethylbenzidine, and 4,4'-dinitro-2-biphenylamine were mutagenic to TA98; 4-aminobiphenyl, 3,3'-dichlorobenzidine-2HCl, 3, 3'-dimethoxybenzidine, and 4,4'-dinitro-2-biphenylamine were mutagenic to TA100. Physicochemical parameters of these compounds including oxidation potentials, the energy difference between the lowest unoccupied molecular orbital and the highest occupied molecular orbital, ionization potentials, dipole moment, relative partition coefficient, and basicity did not correlate with their bacterial mutagenic activities.

Effects of dehulled adlay on the culture count of some microbiota and their metabolism in the gastrointestinal tract of rats.

Experiments were conducted to study the effect of a dietary supplement of dehulled adlay (Coix lachryma-jobi L. var. ma-yuen Stapf) on the culture counts of some important groups of intestinal bacteria and their metabolism in the gastrointestinal (GI) tract of Sprague-Dawley rats. Rats were divided into four groups, and each group was fed a diet containing different levels of dehulled adlay for 30 days as follows: 0% (control), 5%, 20%, and 40%. All animals fed with adlay had normal healthy intestinal walls and no pathogenic signs whatsoever. There were no significant differences in body weight gain or the cecal pH between different groups of rats. Both the 20% and 40% groups had lower culture counts of enterics in their feces than the 5% and control groups, whereas the culture counts of fecal lactic acid bacteria were higher in feces of rats fed with adlay than in the control group. Cecal total short-chain fatty acid (SCFA) content and fecal SCFA were significantly higher in the 20% and 40% groups than in the control and 5% groups. All the adlay-fed rats had a higher fecal butyric acid concentration than the control rats. It is concluded that adlay has a significant influence on the growth of intestinal bacteria, which may ultimately affect the physiology and other functions of GI tracts of rats.

Mutagenicity and antimutagenicity studies of tannic acid and its related compounds.

Tannic acid and its hydrolysed products such as ellagic acid, gallic acid and propyl gallate were tested for mutagenicities using Ames Salmonella tester strains TA98 and TA100. Also, the antimutagenic activities of these compounds against a number of direct mutagens including 2-nitrofluorene (2-NF), 4,4'-dinitro-2-biphenylamine, 1-nitropyrene, 1,3-dinitropyrene, 2-nitro-p-phenylenediamine, 3-nitro-o-phenylenediamine, 4-nitro-o-phenylenediamine were tested. None of these tannic acid compounds was mutagenic. They also failed to show antimutagenic activity towards the tested direct mutagens. However, tannic acid at non-growth inhibitory concentrations reduced the revertant numbers of TA98 in the presence of S9 mix when benzidine, 3,3'-4,4'-tetraminobiphenyl, 4-aminobiphenyl, and N,N-N', N'-tetramethylbenzidine were used as the mutagens. These results suggest that tannic acid, but not its hydrolytic products, affects the metabolic activation of these mutagens.

Viresin. A novel antibacterial protein from immune hemolymph of Heliothis virescens pupae.

Immune hemolymph was collected from fifth instar larvae and 1-day-old pupae of Heliothis virescens after injection of prepupae with live Enterobacter cloacae. Induction of antibacterial activity against Escherichia coli K12 D31 was 7.5 times greater in pupal than in larval immune hemolymph. Lysozyme activity of immune pupal hemolymph against Micrococcus lysodeikticus was 11 times greater when compared with lysozyme activity of immune larval hemolymph. Early pupal immune response with regard to antibacterial activity was much greater than larval immune response in H. virescens. Normal pupal hemolymph showed an increase in antibacterial activity and lysozyme that was induced during metamorphosis. Antibacterial protein was isolated together with lysozyme by gel filtration chromatography and then separated from lysozyme by sequential electrophoresis with a native acid gel and SDS gel. Molecular mass of antibacterial protein was estimated to be 12 kDa. The N-terminal amino acid sequence of 12-kDa protein was different from those of antibacterial molecules found in other insects and has not been identified before. A sample containing 12-kDa protein was negative for immunoblotting with anti-synthetic cecropin B antibody. We have named the novel 12-kDa antibacterial protein viresin. Viresin showed antibacterial activity against several Gram-negative bacteria including E. cloacae but not against Gram-positive bacteria.

Larval and pupal induction and N-terminal amino acid sequence of lysozyme from Heliothis virescens.

Fifth instar larvae and prepupae of Heliothis virescens (tobacco budworm) were injected with live Enterobacter cloacae and bled at different times after vaccination. Immune pupal hemolymph showed a 54 times increase in lysozyme activity when compared with normal larval hemolymph, and an 11 times increase of lysozyme activity when compared with immune larval hemolymph. Lysozyme activity of the normal pupal hemolymph increased as greatly as did lysozyme activity of the immune larval hemolymph after metamorphosis. The pupal immune response with regard to lysozyme was much greater than the larval immune response in H. virescens. Lysozyme was purified by heat treatment at 100 degrees C and a chromatography series that included reverse-phase HPLC. The molecular mass of H. virescens lysozyme was approximately 16 kDa by SDS-PAGE which is greater than other insect lysozymes and chicken lysozyme. Amino acid sequence of the N-terminus showed that H. virescens lysozyme is 82% homologous with lysozyme of Manduca sexta and Galleria mellonella. CNBr cleavage of H. virescens lysozyme produced 11 and 6 kDa peptide fragments indicating that one methionine was present, which was also supported by amino acid analysis. However, methionine was located at the carboxyl terminal side rather than the N-terminal side as judged by the N-terminal sequences of each peptide fragment. The residue 22 in most lepidopteran lysozymes is methionine, whereas H. virescens lysozyme had a leucine at residue 22. There was an amino acid deletion near the carboxyl terminal side of H. virescens lysozyme as also found in Trichoplusia ni.

Postoperative pain relief in primigravida caesarean section patients--combination of intrathecal morphine and epinephrine.

BACKGROUND: Uterine contraction is less severe in primigravida patients. Intrathecal coadministration of morphine and epinephrine may provide an easy way of postcaesarean pain control. METHODS: Twenty-eight primigravida patients who requested postcaesarean pain control were studied for the effectiveness of coadministration of intrathecal morphine and epinephrine. The solution for spinal anesthesia which contained 0.2 mg morphine, 0.1 mg epinephrine and 10 mg hyperbaric bupivacaine was injected intrathecally. Another 30 primigravida patients were collected randomly as control. In the control group, normal saline and 0.1 mg epinephrine were used with bupivacaine. Side effects from intrathecal morphine and the need of analgesia were recorded within 48 h. RESULTS: In the study group, 89.3% (25/28) of patients did not need further narcotics for pain relief during their hospitalization after caesarean section. 96.4% (27/28) of patients needed only one dose of 50 mg intramuscular meperidine (Demerol) or no narcotic at all for pain relief within 48 h. No respiratory depression occurred. In the control group, each patient received in the average 6-7 doses of 50 mg Demerol for pain control within 48 h. CONCLUSIONS: Our results showed that 0.2 mg morphine and 0.1 mg epinephrine in combination with 10 mg hyperbaric bupivacaine given intrathecally could provide a simple way of pain control in primigravida patients undergoing caesarean section.

Antimicrobial activity of tea as affected by the degree of fermentation and manufacturing season.

Bacillus subtilis, Escherichia coli, Proteus vulgaris, Pseudomonas fluorescens, Salmonella sp. and Staphylococcus aureus were used to test the antimicrobial activity of tea flush extract and extracts of various tea products. Among the six test organisms, P. fluorescens was the most sensitive to the extracts, while B. subtilis was the least sensitive. In general, antimicrobial activity decreased when the extents of tea fermentation increased. The antimicrobial activities of tea flush extract and extracts of tea products with different extents of fermentation varied with test organisms. Tea flush and Green tea, the unfermented tea, exerted the strongest antimicrobial activity followed by the partially fermented tea products such as Longjing, Tieh-Kuan-Ying, Paochung, and Oolong teas. On the other hand, Black tea, the completely fermented tea, showed the least antimicrobial activity. It was also noted that extracts of Oolong tea prepared in summer exhibited the strongest antimicrobial activity, followed by those prepared in spring, winter and fall.

Muscarinic activation causes biphasic inotropic response and decreases cellular Na+ activity in canine cardiac Purkinje fibers.

In this study, the effects of carbachol (CCh) on twitch tension, intracellular Na+ activity (aiNa), and action potential were simultaneously measured in canine cardiac Purkinje fibers in order to examine the regulation of inotropy through muscarinic receptors and its relation to aiNa. In fibers driven at 1 Hz, CCh (10 microM) initially and transiently decreased and then increased the twitch tension by 36 +/- 8%. The action potential showed a significant elevation of the plateau and a significant shortening of the duration at 90% repolarization (APD90), from 403 +/- 7 to 389 +/- 7 ms. The aiNa decreased from 7.4 +/- 0.4 to 6.7 +/- 0.3 mM (n = 23, p < 0.05). Atropine (1 microM) decreased the twitch tension by 21 +/- 6% (n = 7, p < 0.05) without significant effects on the action potential and aiNa, and inhibited the effects of CCh. Cs+ (20 mM) increased the plateau height and APD90, enhanced the twitch tension by 66 +/- 24%, but decreased aiNa from 7.3 +/- 0.3 to 6.3 +/- 0.4 mM (n = 6, p < 0.05). In the presence of 20 mM Cs+, some fibers generated slow responses. The addition of 10 microM CCh further increased the twitch tension and APD90, and decreased aiNa from 6.3 +/- 0.4 to 5.3 +/- 0.3 mM. Ouabain (0.3 microM) increased the twitch tension and aiNa, and inhibited the CCh-induced decrease of aiNa. In the presence of ouabain, 20 mM Cs+ depolarized the fiber and generated slow responses with a decreased aiNa. The addition of 10 microM CCh enhanced the slow action potential, and increased aiNa although there was a transient decrease during early exposure. These results suggest that activation of muscarinic receptors in canine Purkinje fibers results in an enhancement of the Na+-K+ pump activity and a biphasic inotropic response, probably via different receptor subtypes. The inhibitory effect, most likely through M2 receptors, is associated with the activation of K+ channels. The stimulatory effect, on the other hand, is probably due to the action on the M1 receptors, resulting in increases in Ca2+ currents.

Horace A. Barker (1907-) pioneer of anaerobic metabolism.

Dr Horace A. Barker was born and raised in California. He obtained his Ph.D. in chemistry from the University of California, Berkeley in 1933, and became a faculty member at the same campus in 1936. He devoted his research to the study of bacterial metabolism. His contributions include the detailed studies of various aspects of metabolism such as synthesis and oxidation of fatty acids, fermentation of amino acids and purines, and carbohydrate transformations. He isolated and determined the structure and function of some enzymes and coenzymes from bacteria. He also specifically described many anaerobic metabolic pathways. Dr Barker retired in 1976.

Mechanism of inhibition of tannic acid and related compounds on the growth of intestinal bacteria.

Tannic acid, propyl gallate and methyl gallate, but not gallic acid, were found to be inhibitory to the growth of intestinal bacteria Bacteroides fragilis ATCC 25285, Clostridium clostridiiforme ATCC 25537, C. perfringens ATCC 13124, C. paraputrificum ATCC 25780, Escherichia coli ATCC 25922, Enterobacter cloacae ATCC 13047, Salmonella typhimurium TA98 and S. typhimurium YG1041 at 100-1000 microg/ml in culture broth. Neither Bifidobacterium infantis ATCC 15697 nor Lactobacillus acidophilus ATCC 4356 was inhibited by any of the above compounds up to 500 microg/ml. Tannic acid has a much greater relative binding efficiency to iron than propyl gallate, methyl gallate or gallic acid. The inhibitory effect of tannic acid to the growth of intestinal bacteria may be due to the strong iron binding capacity of tannic acid; whereas the effect of propyl gallate and methyl gallate probably occurs by a different mechanism. The growth of E. coli was restored by the addition of iron to the medium after the precipitate caused by tannic acid was removed. Neither B. infantis nor L. acidophilus require iron for growth. This probably contributes to their resistance to tannic acid. Because tannins are abundant in the human diet, tannins may affect the growth of some intestinal bacteria and thus may have an impact on human health.

Tannins and human health: a review.

Tannins (commonly referred to as tannic acid) are water-soluble polyphenols that are present in many plant foods. They have been reported to be responsible for decreases in feed intake, growth rate, feed efficiency, net metabolizable energy, and protein digestibility in experimental animals. Therefore, foods rich in tannins are considered to be of low nutritional value. However, recent findings indicate that the major effect of tannins was not due to their inhibition on food consumption or digestion but rather the decreased efficiency in converting the absorbed nutrients to new body substances. Incidences of certain cancers, such as esophageal cancer, have been reported to be related to consumption of tannins-rich foods such as betel nuts and herbal teas, suggesting that tannins might be carcinogenic. However, other reports indicated that the carcinogenic activity of tannins might be related to components associated with tannins rather than tannins themselves. Interestingly, many reports indicated negative association between tea consumption and incidences of cancers. Tea polyphenols and many tannin components were suggested to be anticarcinogenic. Many tannin molecules have also been shown to reduce the mutagenic activity of a number of mutagens. Many carcinogens and/or mutagens produce oxygen-free radicals for interaction with cellular macromolecules. The anticarcinogenic and antimutagenic potentials of tannins may be related to their antioxidative property, which is important in protecting cellular oxidative damage, including lipid peroxidation. The generation of superoxide radicals was reported to be inhibited by tannins and related compounds. The antimicrobial activities of tannins are well documented. The growth of many fungi, yeasts, bacteria, and viruses was inhibited by tannins. We have also found that tannic acid and propyl gallate, but not gallic acid, were inhibitory to foodborne bacteria, aquatic bacteria, and off-flavor-producing microorganisms. Their antimicrobial properties seemed to be associated with the hydrolysis of ester linkage between gallic acid and polyols hydrolyzed after ripening of many edible fruits. Tannins in these fruits thus serve as a natural defense mechanism against microbial infections. The antimicrobial property of tannic acid can also be used in food processing to increase the shelf-life of certain foods, such as catfish fillets. Tannins have also been reported to exert other physiological effects, such as to accelerate blood clotting, reduce blood pressure, decrease the serum lipid level, produce liver necrosis, and modulate immunoresponses. The dosage and kind of tannins are critical to these effects. The aim of this review is to summarize and analyze the vast and sometimes conflicting literature on tannins and to provide as accurately as possible the needed information for assessment of the overall effects of tannins on human health.