Effects of enzymatically hydrolyzed yeast supplementation on blood attributes, antioxidant status and gene expression of cytokines in vaccinated dairy cows

This study was done to assess the effects of hydrolyzed yeast on blood cells counts, antioxidant status and gene expression of pro-inflammatory and anti-inflammatory cytokines of vaccinated dairy cows. Twenty Holstein lactating dairy cows were randomly divided into four groups received basal diet without (control) and with 10, 20 and 30 g/d/head of hydrolyzed yeast. Cows were vaccinated against foot and mouth disease virus at day 10 and blood samples were taken 10 days after. Cows received hydrolyzed yeast at doses of 20 and 30 g/d/head had the lowest and those in the control group had the highest malondialdehyde concentration. Cows received hydrolyzed yeast at dose of 20 g/d/head had the highest lymphocyte and the lowest neutrophil/lymphocyte ratio. IL-1β and TNF-α downregulated and INF-γ up-regulated in cows received different doses of hydrolyzed yeast. The lowest expression of IL-1β and TNF-α and the highest expression of INF-γ was for cows received hydrolyzed yeast at dose of 20 g/d/head. The highest titers against foot and mouth disease virus were for cows received hydrolyzed yeast at dose of 20 g/d/head and the lowest titer was for the control group. Supplementation of 20 g/d/head hydrolyzed yeast recommended in vaccinated cows.

Effect of live yeast supplementation on energy partitioning and ruminal fermentation characteristics of steers fed a grower-type diet in heat-stress conditions

The objective of this trial was to determine the influence of live yeast supplementation (LY), environmental condition (ENV), and their interaction (TRT) on energy partitioning, nitrogen metabolism, and ruminal fermentation dynamics of steers receiving a grower-type diet. The effects of LY and ENV were investigated using a 2 × 2 crossover design that spanned five periods. Eight Angus-crossbred steers were randomly split into pairs and housed in four outdoor pens outfitted with an individualized feeding system. Animals were limit-fed a grower diet (DIET) at 1.2% shrunk body weight (SBW) with no live yeast supplementation (NOY) or a grower diet top-dressed with 10 g LY/d for 14 d (1.2 × 1012 CFU/d). On days 13 and 14, animals were subjected to one of two ENV conditions, thermoneutral (TN; 18.4 ± 1.1 °C, 57.6 ± 2.8% relative humidity [RH]) or heat stress (HS; 33.8 ± 0.6 °C, 55.7 ± 2.7% RH), in two side-by-side, single-stall open-circuit, indirect respiration calorimetry chambers. Data were analyzed using a random coefficients model. Carryover effects were examined and removed from the model if not significant. Gross (GE), digestible, metabolizable, heat, and retained energies were not influenced by DIET, ENV, or TRT (P ≥ 0.202). Gaseous energy, as a percentage of GE, tended to increase during HS (P = 0.097). The only carryover effect in the study was for oxygen consumption (P = 0.031), which could be attributed to the tendency of NOY (P = 0.068) to have greater oxygen consumption. DIET, ENV, or TRT (P ≥ 0.154) had no effects on total animal methane or carbon dioxide emissions. Similarly, DIET, ENV, or TRT (P ≥ 0.157) did not affect ruminal pH, redox, protozoa enumeration, ruminal ammonia concentrations, and acetate-to-propionate ratio. Propionate concentrations were the greatest in animals in TN conditions receiving LY (P = 0.034) compared to the other TRT. This effect is mirrored by TN-LY tending to have greater acetate concentrations (P = 0.076) and total VFA concentrations (P = 0.065). Butyrate concentrations tended to be greater for animals fed LY (P = 0.09). There was a tendency for LY to have elevated numbers of Fusobacterium necrophorum (P = 0.053). Although this study lacked effects of LY on energy partitioning, nitrogen metabolism, and some ruminal parameters during HS, further research should be completed to understand if LY is a plausible mitigation technique to enhance beef animals' performance in tropical and sub-tropical regions of the world.

Evaluation of a Yeast Hydrolysate from a Novel Strain of Saccharomyces cerevisiae for Mycotoxin Mitigation using In Vitro and In Vivo Models

Mycotoxicoses in animals are caused by exposure to mycotoxin-contaminated feeds. Disease risk is managed using dietary adsorbing agents which reduce oral bioavailability. The objective of this work was to evaluate the efficacy of three selected yeast products as mycotoxin binders using in vitro and in vivo models. Their capacity to adsorb deoxynivalenol (DON), zearalenone (ZEA), and ochratoxin A (OTA) was evaluated using an in vitro model designed to simulate the pH conditions during gastric passage in a monogastric animal. Results showed that only one product, an enzymatic yeast hydrolysate (YHY) of a novel strain Saccharomyces cerevisiae, adsorbed about 45% of DON in solution. Next, we determined the effect of YHY on oral absorption of a DON, ZEA, and OTA mixture using a toxicokinetic model in swine. Toxicokinetic modeling of the plasma concentration-time profiles of DON, OTA, and zearalenone-glucuronide (ZEA-GlcA) showed that YHY tended to reduce the maximal plasma concentration of OTA by 17%. YHY did not reduce oral bioavailability of OTA, DON, and ZEA-GlcA. Within the context of this experiment, and despite some positive indications from both the in vitro and in vivo models employed, we conclude that the YHY prototype was not an effective agent for multiple mycotoxin adsorption.

Fish Oil, Se Yeast, and Micronutrient-Enriched Nutrition as Adjuvant Treatment during Target Therapy in a Murine Model of Lung Cancer

Despite the effectiveness of primary treatment modalities for cancer, the side effects of treatments, medication resistance, and the deterioration of cachexia after disease progression lead to poor prognosis. A supportive treatment modality to overcome these limitations would be considered a major breakthrough. Here, we used two different target drugs to demonstrate whether a nutraceutical formula (fish oil, Se yeast, and micronutrient-enriched nutrition; NuF) can interfere with cancer cachexia and improve drug efficacy. After Lewis lung cancer (LLC) tumor injection, the C57BL/6 mice were orally administered targeted therapy drugs Iressa and Sutent alone or combined with NuF for 27 days. Sutent administration effectively inhibited tumor size but increased the number of lung metastases in the long term. Sutent combined with NuF had no significant difference in tumor weight and metastasis compare with Sutent alone. However, NuF slightly attenuated metastases number in lung may via mesenchymal marker N-cadherin suppression. NuF otherwise increased epithelial-like marker E-cadherin expression and induce NO-mediated intrinsic apoptotic pathway in tumor cells, thereby strengthening the ability of the targeted therapy drug Iressa for inhibiting tumor progression. Our results demonstrate that NuF can promote the anticancer effect of lung cancer to targeted therapy, especially in Iressa, by inhibiting HIF-1α and epithelial-mesenchymal transition (EMT) and inducing the apoptosis of lung cancer cells. Furthermore, NuF attenuates cancer-related cachectic symptoms by inhibiting systemic oxidative stress.

Evaluation of antioxidant capacity and immunomodulatory effects of yeast hydrolysates for hepatocytes of blunt snout bream (Megalobrama amblycephala)

An in-vitro study was carried out to examine the effects of yeast hydrolysate (YH) on antioxidant capacity and innate immunity of blunt snout bream (Megalobrama amblycephala) hepatocytes. Fish primary hepatocytes were seeded at a density of 3 × 10⁵ cells mL^-1 in 6-well tissue culture plates and treated with two different media including: 1) DMEM/F12 medium (control), and 2) YH medium [DMEM/F12 + 0.1 g L^-1 YH]. After incubation for 24 h, the culture medium and primary hepatocytes were collected for subsequent analyses. The results showed no significant (P > 0.05) effect of YH on aspartate aminotransferase (AST), alanine aminotransferase (ALT) and lactate dehydrogenase (LDH) activities and urea nitrogen (UN) concentration in the conditioned medium. However, significantly (P < 0.05) higher ALT and AST activities were found in YH treated hepatocytes compared to control. Moreover, YH supplementation led to significant enhancement of superoxide dismutase (SOD), catalase (CAT), alternative complement pathway (ACH50) and glutathione peroxidase (GPX) activities and reduction of malondialdehyde (MDA) concentration in the conditioned medium. Furthermore, YH application upregulated the expression of SOD, CAT and NOX2 genes and downregulated mRNA levels of Keap1, Nrf2 and Bach1 in hepatocytes. Also, markedly higher lysozyme activity and albumin concentration were found in the conditioned medium of YH group compared to the control. Additionally, expression of immune-related genes such as antimicrobial peptides 1 (Leap 1) and Leap 2 were significantly upregulated by YH application. Down-regulated expression of NADPH oxidase-2 (NOX2), Kelch-like-ECH-associated protein 1 (Keap1), NF-E2-related factor 2 (Nrf2) and BTB and CNC homolog 1 (Bach1) were observed in YH treated hepatocytes. To conclude, YH supplementation improved antioxidant capacity and innate immunity of blunt snout bream hepatocytes.

Fecal bacterial community of finishing beef steers fed ruminally protected and non-protected active dried yeast

Our previous study suggested that supplementation of high-grain diets with ruminally protected and non-protected active dried yeast (ADY) may potentially reduce manure pathogen excretion by feedlot cattle. We hypothesized that feeding ruminally protected ADY might change the fecal bacterial community of finishing cattle. The objective of this study was to investigate the effects of feeding ruminally protected and non-protected ADY to finishing beef steers on their fecal bacterial community. Fresh fecal samples were collected on day 56 from 50 steers fed one of five treatments: 1) control (no monensin, tylosin, or ADY), 2) antibiotics (ANT, 330 mg monensin + 110 mg tylosin·steer-1d-1), 3) ADY (1.5 g·steer-1d-1), 4) encapsulated ADY (EDY; 3 g·steer-1d-1), and 5) a mixture of ADY and EDY (MDY; 1.5 g ADY + 3 g EDY·steer-1d-1). Bacterial DNA was extracted from fecal samples and sequenced using a MiSeq high-throughput sequencing platform. A total number of 2,128,772 high-quality V4 16S rRNA sequences from 50 fecal samples were analyzed, and 1,424 operational taxonomic units (OTU) were detected based on 97% nucleotide sequence identity among reads, with 769 OTU shared across the five treatments. Alpha diversity indices, including species observed, Chao estimate, abundance-based coverage estimator, Shannon, Simpson, and coverage, did not differ among treatments, and principal coordinate analysis revealed a high similarity among treatments without independent distribution. Bacteroidetes and Firmicutes were dominant phyla in the fecal bacterial community for all treatments, with a tendency (P < 0.10) for greater relative abundance of Bacteroidetes but lesser Firmicutes with ANT, EDY, and MDY compared with control steers. Prevotella was the dominant genus in all treatments and steers supplemented with ANT, EDY, and MDY had greater (P < 0.05) relative abundance of Prevotella than control steers, but lesser (P < 0.03) relative abundance of Oscillospira. No differences between ADY and control were observed for the aforementioned variables. Fecal starch contents were not different among treatments, but the relative abundance of Bacteroidetes, as well as Prevotella at genera level, tended (P < 0.06) to be positively correlated to fecal starch content. We conclude that supplementing ruminally protected or non-protected ADY or ANT had no effect on diversity and richness of fecal bacteria of finishing beef cattle, whereas feeding protected ADY or ANT to finishing beef steers altered the dominant fecal bacteria at phylum and genus levels. Therefore, supplementation of ruminally protected ADY may potentially improve intestinal health by stimulating the relative abundance of Prevotella.

Effects of Selenium-Enriched Yeast Improved Aflatoxin B1-Induced Changes in Growth Performance, Antioxidation Capacity, IL-2 and IFN-γ Contents, and Gene Expression in Mice

Sixty Kunming mice were randomly assigned into three groups. Mice in a control group were fed a basal diet, while mice in AFB1 group and AFB1-Se group were fed the basal diet supplemented with 250 μg/kg AFB1 or the basal diet supplemented with 250 μg/kg AFB1 and 0.2 mg/kg selenium as selenium-enriched yeast, respectively. On day 30 of the experiment, growth performance, glutathione peroxidase (GSH-Px) activities, total antioxidant capacity (T-AOC) levels, and malondialdehyde (MDA) contents in liver, interleukin-2 (IL-2), and interferon-γ (IFN-γ) contents in serum, and cytochrome P3a11 (Cyp3a11), IL-2, IFN-γ, and GSH-Px1 mRNA levels in liver were determined. The results showed that final weights, weight gains, T-AOC levels, GSH-Px1, and IFN-γ mRNA levels in AFB1-Se group and control group were higher or significantly higher than those in AFB1 group (P < 0.05 or P < 0.01), respectively. Body length gains in AFB1 group were lower than those in the control group (P < 0.05), while there was no significant difference between the AFB1-Se and control groups (P > 0.05). IL-2 contents and liver IL-2 mRNA levels in AFB1-Se group were significantly higher than those in the AFB1 group and control group (P < 0.01), and IL-2 contents in the control group were also significantly higher than those in the AFB1 group (P < 0.01). IFN-γ contents in AFB1-Se group and AFB1 group were significantly higher than those in control group (P < 0.01), while IFN-γ contents in AFB1-Se group were significantly lower than those in AFB1 group (P < 0.01). Cyp3a11 mRNA levels in AFB1-Se group and AFB1 group were significantly higher than those in the control group (P < 0.01). The results indicated that selenium-enriched yeast could partly reduce the toxicity induced by AFB1 in mice, including improving growth performance, antioxidation capacity, IL-2 and IFN-γ contents, and enhancing IL-2, IFN-γ, and GSH-Px1 mRNA levels.

Supplementation with live yeast increases rate and extent of in vitro fermentation of nondigested feed ingredients by fecal microbiota

Two studies were conducted to investigate the effect of live yeast (LY) on the in vitro fermentation characteristics of wheat, barley, corn, soybean meal (SBM), canola meal, and distillers dried grains with solubles (DDGS). In Study 1, LY yeast was added directly to in vitro fermentations inoculated with feces from lactating sows, whereas as in study 2, feces collected from lactating sows fed LY as a daily supplement was used. Selected feedstuffs were digested and the residue added to separate replicated (n = 3) fermentation reactions. Study 1 was conducted in two blocks, whereas study 2 was conducted using feces collected after a period of 3 (Exp. 1) or 4 wk (Exp. 2) of LY supplementation. Accumulated gas produced over 72 h was modeled for each substrate and the kinetics parameters compared between LY and control groups. The molar ratio of the volatile fatty acids (VFAs) produced in vitro were also compared at 12 and 72 h of incubation. In study 1, in vitro addition of yeast increased (P < 0.001) the rate of gas production (Rmax). However, a yeast × substrate effect (P < 0.05) observed for total gas accumulated (A), time to half asymptote (B), and time required to reach maximum rate of fermentation (Tmax) suggested that yeast-mediated increases in extent and rate of fermentation varied by substrate. Greater total gas production was observed only for corn and SBM, associated with greater B and Tmax. Supplementation with LY appeared to increase A and Rmax although with variation between experiments and substrates. In Exp. 1, LY decreased (P < 0.05) B and Tmax. However, a yeast × substrate effect (P < 0.05) was observed for only A (for wheat, barley, corn, and corn DDGS) and Rmax (wheat, barley, corn, and wheat DDGS). In Exp. 2, LY increased (P < 0.0001) A and decreased B. However, an interaction (P < 0.05) with substrates was observed for Rmax (except SBM) and Tmax. With exception of the DDGS samples, LY supplementation increased (P < 0.05) VFA production at 12 and 72 h of incubation. Yeast increased (P < 0.05) the molar ratios of acetic acid and branch-chain fatty acids at 12 h of incubation; however, this response was more variable by substrate at 72 h. In conclusion, LY supplementation increased the rate and extent of in vitro fermentation of a variety of substrates prepared from common feedstuffs. Greater effects were observed when LY was fed to sows than added directly in vitro, suggesting effects on fermentation were not mediated directly.

Selenium-Rich Yeast Protects Against Aluminum-Induced Renal Inflammation and Ionic Disturbances

The aim of this study was to evaluate the protective effects of SeY (selenium-rich yeast) against Al (aluminum)-induced inflammation and ionic imbalances. Male Kunming mice were treated with Al (10 mg/kg) and/or SeY (0.1 mg/kg) by oral gavage for 28 days. The degree of inflammation was assessed by mRNA expression of inflammatory biomarkers. Ionic disorders were assessed by determining the Na⁺, K⁺, and Ca²⁺ content, as well as the alteration in ATP-modifying enzymes (ATPases), including Na⁺K⁺-ATPase, Ca²⁺-ATPase, Mg²⁺-ATPase, Ca²⁺Mg²⁺-ATPase, and the mRNA levels of ATPase's subunits in kidney. It was observed here that SeY exhibited a significant protective effect on the kidney against the Al-induced upregulation of pro-inflammatory and downregulation of anti-inflammatory cytokines. Furthermore, a significant effect of Al on the Na⁺, K⁺, Ca²⁺, and Mg²⁺ levels in kidney was observed, and Al was observed to decrease the activities of Na⁺K⁺-ATPase, Mg²⁺-ATPase, and Ca²⁺Mg²⁺-ATPase. The mRNA expression of the Na⁺K⁺-ATPase subunits and Ca²⁺-ATPase subunits was regulated significantly by Al. Notably, SeY modulated the Al-induced alterations of ion concentrations, ATPase activity, and mRNA expression of their subunits. These results suggest that SeY prevents renal toxicity caused by Al via regulation of inflammatory responses, ATPase activities, and transcription of their subunits.

Immobilizing yeast β-glucan on zinc-layered hydroxide nanoparticle improves innate immune response in fish leukocytes

Nanoparticle-based delivery technologies have played a central role in a wide variety of applications, including cell therapy, gene transformation, and cellular delivery of molecular dyes. This work synthesized via ionic exchange a nanoparticle consisting of zinc-layered hydroxychloride coupled with yeast β-glucan (ZG), whose cellular immune response was evaluated using fish spleen leukocytes. Leukocytes from the marine Pacific red snapper (Lutjanus peru) were stimulated with zinc-layered hydroxychloride (ZHC) coupled with yeast β-glucan (GLU) and challenged with live Vibrio parahaemolyticus after 24 h. Structural characterization of this yeast glucan by proton nuclear magnetic resonance (NMR) indicated structures containing (1-6)-branched (1-3)-β-D-glucan. The ZHC and ZG were characterized with X-ray diffraction, infrared spectroscopy, scanning electron microscopy and thermogravimetric analysis. The results of the immunological study showed that ZHC, GLU or ZG were safe for leukocytes because cell viability was higher than 80% compared with DMSO or V. parahaemolyticus exposure. The ZG or GLU treatments enhanced nitric oxide production, superoxide dismutase, catalase and peroxidase activities. Induction of anti- and pro-inflammatory cytokine (IL-1β, IL-6, IL-8, IL-10, IL-12 and IL-17) genes was more pronounced in ZG or GLU treatments compared to the other groups. Based on the results, ZHC nanoparticles can be used as a delivery carrier of yeast β-glucan for enhancing immunity in fish and have great potential application in the aquaculture industry.

Effects of dietary yeast culture on growth performance, immune response and disease resistance of gibel carp (Carassius auratus gibelio CAS Ⅲ)

A 50-day feeding trial was carried out to evaluate the partial replacement of fishmeal by yeast culture (YC) on growth performance, immune response and resistance against Aeromonas hydrophila in gibel carp CAS Ⅲ (Carassius auratus gibelio). Four isonitrogenous and isoenergetic practical diets including a basal diet (the control diet containing 10% fish meal, D0) and three yeast culture diets (substituting 20%, 40%, 60% of the fishmeal in the basal diet, D20, D40 and D60, respectively) were formulated. Each diet was randomly allocated to quadruplicate fish groups (average initial body weight: 28.70 ± 0.03 g) reared in a recirculating system. After the growth trial, bacterial challenge test was conducted. The results showed that no noteworthy variations in feed intake, growth performance and morphology indices were found among groups (P > 0.05). YC Supplemented diet exerted little significant influence on plasma parameters including triglyceride, glucose, creatinine, total protein and urea nitrogen compared with the control group (P > 0.05). No obvious variations were found in activities of plasma lysozyme, IgM, MPO and SOD before challenge test among dietary treatments (P > 0.05), whereas considerable higher value of the foresaid indicators was discovered in D40 after bacteria challenge (P < 0.05). Transcriptional levels of Toll like receptor 2 (TLR2), myeloid differentiation factor 88 (MyD88), Toll/IL-1 receptor domain-containing adaptor protein (TIRAP) and interleukin-1β (IL-1β) in spleen after challenge were significantly up-regulated in D40 compared with D0 (P < 0.05). Cumulative survival rate in D40 and D60 were significantly higher than those in D0 and D20 (P < 0.05). Taken together, yeast culture could be a suitable fishmeal alternative in diets of gibel carp and dietary inclusion of 4 g YC per 100 g diet enhanced the immunity and disease resistance of gibel carp partly via TLR2 pathway.

Effectiveness of a Sugar-Yeast Monitor and a Chemical Lure for Detecting Bed Bugs

Effective bed bug (Cimex lectularius L.) monitors have been actively sought in the past few years to help detect bed bugs and measure the effectiveness of treatments. Most of the available active monitors are either expensive or ineffective. We designed a simple and affordable active bed bug monitor that uses sugar-yeast fermentation and an experimental chemical lure to detect bed bugs. The sugar-yeast mixture released carbon dioxide at a similar rate (average 405.1 ml/min) as dry ice (average 397.0 ml/min) during the first 8 h after activation. In naturally infested apartments, the sugar-yeast monitor containing an experimental chemical lure (nonanal, L-lactic acid, 1-octen-3-ol, and spearmint oil) was equally effective as the dry ice monitor containing the same lure in trapping bed bugs. Placing one sugar-yeast monitor per apartment for 1-d was equally effective as 11-d placement of 6-18 Climbup insect interceptors (a commonly used bed bug monitor) under furniture legs for trapping bed bugs. When carbon dioxide was present, pair-wise comparisons showed the experimental lure increased trap catch by 7.2 times. This sugar-yeast monitor with a chemical lure is an affordable and effective tool for monitoring bed bugs. This monitor is especially useful for monitoring bed bugs where a human host is not present.

Response of lactating cows to live yeast supplementation during summer

Dairy cows experiencing heat stress have reduced intake and increased reliance on glucose, making feeding strategies capable of improving diet digestibility plausible for improving postrumen nutrient flow and performance. The effect of yeast on digestion and performance of lactating cows during the warm summer months of southeastern Brazil was evaluated. Cows were individually fed in tie stalls and temperature-humidity index was above 68 during 75.6% of the experiment. Twenty-eight Holstein cows (207±87 d in milk) received a standard diet for 14 d and then a treatment for 70 d, in a covariate-adjusted, randomized block design with repeated measures over time. Treatments were yeast (Saccharomyces cerevisiae) or control. Yeast was top dressed to the diet in the morning, equivalent to 25×10(10) cfu of live cells and 5×10(10) cfu of dead cells. The diet contained corn silage (37.7%), Tifton silage (7.1%), raw soybeans (4.1%), soybean meal (16.5%), finely ground corn (20.7%), and citrus pulp (11.9%). Yeast increased milk (26.7 vs. 25.4 kg/d) and solids yield (3.06 vs. 2.92 kg/d), especially lactose. Response in milk yield was consistent over time and started at d 5. The daily intake of digestible OM, total-tract digestibility of nutrients, urinary allantoin excretion, chewing pattern throughout the day, and dry matter intake did not respond to yeast. A trend was observed for increased plasma glucose with yeast (62.9 vs. 57.3mg/dL), lowered respiratory frequency (48 vs. 56 breaths/min), and increased plasma niacin content (1.31 vs. 1.22 µg/mL), though cows had similar rectal temperature. Ruminal lactate and butyrate as proportions of ruminal organic acids were reduced by yeast, but no effects on other organic acids, ruminal pH, or protozoa content were detected. Plasma urea N over 24h was increased by yeast. On d 72 to 74, citrus pulp was abruptly replaced with finely ground corn to induce acidosis. The increased load of starch increased dry matter intake between 0700 and 1300 h, jugular blood partial pressure of CO2, HCO3-, and base excess, and decreased blood pH for both treatments. The yeast treatment had a higher blood pH compared with the control, 7.34, and 7.31, respectively. Yeast supplementation improved lactation performance of dairy cows under heat stress. Improvement in lactation performance apparently involved the regulation of body homeothermia, rather than improved digestibility.

Effects of methionine chelate- or yeast proteinate-based supplement of copper, iron, manganese and zinc on broiler growth performance, their distribution in the tibia and excretion into the environment

A straight-run flock of 1-day-old Cobb 400 chicks (n = 432) was distributed into four treatment groups (9 replicate pens in each group, 12 birds in a pen) for a 38-day feeding trial evaluating the effects of a methionine chelate (Met-TM)- or a yeast proteinate (Yeast-TM)-based supplement of copper (Cu), iron (Fe), manganese (Mn) and zinc (Zn) on growth performance, bone criteria and some metabolic indices in commercial broiler chickens. The diets were either not supplemented with any trace elements at all (negative control, NC) or supplemented with an inorganic (sulphate) trace element premix (inorganic TM (ITM), 1 g/kg feed), the Met-TM (1 g/kg feed) and the Yeast-TM (0.5 g/kg feed). Body weight, feed conversion ratio and dressed meat yield at 38 days were better in the Yeast-TM-supplemented group as compared with the NC, ITM and Met-TM groups (p < 0.01). The birds supplemented with Met-TM and Yeast-TM consumed less feed than the NC and ITM-supplemented group (p < 0.001). Supplementation of trace elements irrespective of source increased the total ash content in the tibia (p < 0.001). However, concentration of Cu was lower in the Met-TM and Yeast-TM groups compared with the NC and the ITM groups (p < 0.05) although that of Fe, Mn and Zn was not affected at all by the dietary treatments. Total protein concentration in serum increased when either Met-TM or Yeast-TM was supplemented (p < 0.05) to the birds. Serum alkaline phosphatase activity, however, increased when the trace elements from either inorganic or organic sources were supplemented (p < 0.05). Compared with the ITM-supplemented group, excretion of Cu, Fe, Mn and Zn was lower in the birds supplemented with Met-TM or Yeast-TM, especially in the latter group (p < 0.05). The present experiment revealed that supplementation of broilers with methionine chelates or yeast proteinate forms of Cu, Fe, Mn and Zn improved body weight and feed conversion ratio (FCR) and markedly reduced excretion of the said trace elements. The study revealed that it may be possible to improve broiler performance and reduce excretion of critical trace elements into the environment by complete replacement of inorganic trace minerals from their dietary regime and replacing the same with methionine chelate or yeast proteinate forms.

Chromium, selenium, and zinc multimineral enriched yeast supplementation ameliorates diabetes symptom in streptozocin-induced mice

Chromium, selenium, and zinc malnutrition has been implicated in the pathogenesis of diabetic mellitus. This study aims to investigate the effects of novel multiminerals-enriched yeast (MMEY) which are minerals supplementation containing elevated levels of chromium, selenium, and zinc simultaneously in a diabetic animal model. Streptozocin-induced diabetic male Balb/c mice (n = 80) were randomly divided into diabetes control group and three treatment groups. They were administrated oral gavages with low, medium, or high doses of MMEY, respectively. Meanwhile, healthy male Balb/c mice (n = 40) of the same body weight were randomly assigned into normal control group and high dose of MMEY control group. After 8 weeks duration of treatment, the animals were sacrificed by cervical dislocation. Serum glucose concentrations, lipid profiles, oxidative/antioxidant, and immunity status were determined. No significant adverse effects were observed in the high-dose MMEY control group. Treatment of the diabetic mice with medium- or high-dose MMEY significantly decreased serum glucose, triglyceride, total cholesterol, and malondialdehyde and increased high-density lipoprotein cholesterol, glutathione, and the activities of superoxide dismutase and glutathione peroxidase. In addition, MMEY ameliorated the pathological damage of the pancreatic islets, elevated the thymus or spleen coefficient, and increased the expressions of interleukin-2 and -4 in spleen lymphocytes compared with unsupplemented diabetic mice. In conclusion, these results indicate that supplemental MMEY inhibits hyperglycemia, abates oxidative stress, modulates disorders of lipid metabolism, and reduces the impairment of immune function in diabetic mice; especially notable are the protective effects of medium doses of MMEY on the islet cells of diabetic mice.

Effects of dietary yeast autolysate (Saccharomyces cerevisiae) on performance, egg traits, egg cholesterol content, egg yolk fatty acid composition and humoral immune response of laying hens

BACKGROUND

The objective of this study was to determine the effects of dietary yeast autolysate on performance, egg traits, egg cholesterol content, egg yolk fatty acid composition, lipid oxidation of egg yolk, some blood parameters and humoral immune response of laying hens during a 16 week period. A total of 225 Hyline Brown laying hens, 22 weeks of age, were allocated equally to one control group and four treatment groups. Yeast autolysate (Saccharomyces cerevisiae, InteWall) was used at levels of 1, 2, 3 and 4 g kg(-1) in the diets of the first, second, third and fourth treatment groups respectively.

RESULTS

Dietary treatments did not significantly affect body weight, feed intake and egg traits. Yeast autolysate supplementation increased egg production (P < 0.001) and egg weight (P < 0.001) and improved feed efficiency (P < 0.05). Yeast autolysate at levels of 2, 3 and 4 g kg(-1) decreased egg yolk cholesterol level as mg g(-1) yolk (P < 0.01) and blood serum levels of cholesterol and triglyceride (P < 0.05) and increased antibody titres to sheep red blood cells (P < 0.01). Total saturated fatty acids and the ratio of saturated/unsaturated fatty acids increased (P < 0.01) and total monounsaturated fatty acids (P < 0.001) decreased with yeast autolysate supplementation.

CONCLUSION

Dietary yeast autolysate at levels of 2, 3 and 4 g kg(-1) had beneficial effects on performance, egg cholesterol content and humoral immune response. It is concluded that 2 g kg(-1) yeast autolysate will be enough to have beneficial effects in laying hens.

[Using dietary supplement containing dietary fiber, fermented wine yeasts, vitamins and minerals, under the influence of dust-gas mixture. The experiments on laboratory animals]

In chronic experiment in rats pro for show, what of food biologically active "Rekitsen-RD", promotes increase of efficiency of mechanisms of detoxication, antioxidant activity and immune protection of an organism.

[Development of new sinbiotic product with high contents bifidobacteria]

The article informs about influence of gum arabic, baker's yeast extract, solids-non-fat and mixture of gum arabic and insoluble wheat fibres (Equacia) on the amount of bifidobacteria in the milk.

Influence of chromium-enriched yeast on blood glucose and insulin variables, blood lipids, and markers of oxidative stress in subjects with type 2 diabetes mellitus

The aim of this study was to determine the effect of chromium (Cr)- enriched yeast on blood glucose and insulin variables, blood lipids, and blood markers of oxidative stress in persons with type 2 diabetes mellitus (median duration: 3.0 yr). Thirty-six subjects (9 men, 27 women; mean age: 61.3 yr; mean body mass index: 34.33 kg/m2) were supplemented with 400 microg Cr/d as Cr-enriched yeast (n = 19) or placebo (n = 17) for 12 wk in a randomized, double-blind study. The most interesting results were obtained by comparison of the change in the placebo group to the change in the Cr group. The Cr group showed a significantly greater increase in serum Cr compared to the placebo group (p < 0.05). Supplementation with Cr-enriched yeast was associated with a significant decrease in fasting serum glucose compared to placebo (p < 0.01). Blood markers of oxidative stress glutathione peroxidase activity and levels of reduced glutathione were essentially unchanged in the Cr group after 12 wk, but decreased significantly in the placebo group (p < 0.05, p < 0.01, respectively). Serum HbA1c and glycated protein (fructosamine) were essentially unchanged in the Cr group, whereas HbA1c tended to increase in the placebo group (from 6.94% to 7.11%). Fasting serum insulin decreased in both groups, with a greater tendency in the Cr group (-16.5% vs -9.5%). These data suggest that supplementation of well-controlled type 2 diabetics with Cr-enriched yeast is safe and can result in improvements in blood glucose variables and oxidative stress.

Production of interleukin-1 activity of Kupffer cells from mice treated with the acidic mannan fraction of baker's yeast

We investigated the production of interleukin-1 (IL-1) activity by Kupffer cells (KC) from mice treated with a neutral mannan fraction (WNM) or an acidic mannan fraction (WAM025) from baker's yeast (Saccharomyces cerevisiae) in vivo and in vitro. The mice administered WAM025 showed an increase in the number of KC and the IL-1 production compared with mice administered WNM. In an in vitro stimulation assay using KC from a normal mouse, it was also found that WAM025 displayed an increase in IL-1 production. Diisopropyl fluorophosphate completely inhibited the production of IL-1 by KC from the mice administered WAM025.

Mode of action of plasmolysed yeast on lymphocytes under microgravity stress

A newly developed device to simulate microgravity for space biological investigations under laboratory conditions allowed us to apply a reproducible environmental stress on immunologically active cells. Cell proliferation, soluble IL-2 receptor in the culture supernatant, lymphocyte surface activation markers like CD25 (IL-2R), CD69 and HLA-Dr were the endpoints measured. Untreated donor lymphocyte reactions under microgravity were compared to the same cells treated with an immunomodulator from herbal plasmolysed yeast (Bio-Strath Food Supplement). The main finding is the enhancement of the proliferation inhibition under microgravitational stress by the herbal plasmolysed yeast.

[A growth supplement for "fastidious germs"]

A growth supplement for "fastidious germs" was produced at the Laboratory of Acute Respiratory Infections of "Pedro Kourí" Institute of Tropical Medicine. This supplement was studied by computerized optic spectrophotometry, and chemical composition was determined. The efficacy of this supplement for the culture of Haemophilus influenzae type b, was evidenced using 100 strains, and it was proven that it can be used in concentrations raging from 1 to 10%.

The effect of dietary active dry yeast supplement on performance of sows during gestation-lactation and their pigs

Thirty crossbred sows and their pigs were evaluated through two parities to determine any reproductive or growth performance effects of an active dry yeast supplement added to corn-soybean meal diets. Sow reproductive performance from d 93 of gestation through d 21 of lactation and sow milk composition were evaluated. Pig growth performance was measured from birth to 28 d after weaning. Active dry yeast was added at 0, 1, or .2% of the sow gestation diet, 0, .15, or .3% of the sow lactation diet, 0, .2, or .4% of the pig prestarter diet, 1 wk before and 1 wk after weaning, and 0, .125, or .25% during the last 3 wk in the nursery. The yeast source consisted of a concentrate of live yeast cells of the Saccharomyces cerevisiae strain containing more than 15 x 10(9) live cells/g. Sow body weight at d 93 of gestation, at farrowing, and at d 21 of lactation did not differ (P > .10) among treatment groups. Milk from sows fed active dry yeast contained higher amounts of total solids (P < .05), crude protein (P < .10), and gamma globulin (P < .06) than milk from sows fed the control diet. Sow feed intake during lactation was not affected (P > .10) by treatment, nor were there differences in litter size at birth, litter birth weight, or litter weight at d 21 after farrowing. Active dry yeast supplementation to the sow and pig diets resulted in improved postweaning pig daily gain (P < .05) and gain-to-feed ratio (P < .05) but did not affect (P > .10) feed intake. Based on these data, active dry yeast supplement during late gestation, lactation, and before and after weaning does not alter litter weight at birth or weaning but does increase gamma globulin content of sow's milk and improves postweaning rate and efficiency of weight gain of pigs.

Effect of certain nutrients on the production of dextransucrase from Leuconostoc mesenteroides NRRL B-512F

The effects of certain nutrients on dextransucrase (sucrose: 1,6-alpha-d-glucan 6-alpha-d-glucosyltransferase EC 2.4.1.5) production from Leuconostoc mesenteroides NRRL B-512F were studied. An increase in concentration of sucrose to 4% in the enzyme production medium resulted in the increase of activity of dextransucrase. Higher enzyme yields were obtained at low yeast extract and high phosphate concentrations. The presence of peptone and beef extract in the medium in addition to 2% yeast extract resulted in an enhanced production of dextransucrase. The enzyme activity increased by 30% by both peptone and beef extract. Addition of Tween 80 to the medium enhanced the production of enzyme and the activity was increased by 25%. Magnesium ions stimulated the activity marginally. Sodium fluoride enhanced the activity of dextransucrase by 25%.

Immunological and trophical effects of Saccharomyces boulardii on the small intestine in healthy human volunteers

Saccharomyces boulardii (S.b.) is used for the prevention and treatment of diarrhea of different etiologies. We prospectively investigated the effects of S.b. on lymphocytes and duodenal mucosa. Before and after oral administration of S.b. for 3 weeks, circulating and intestinal lymphocytes were isolated and characterized by flow cytometry. Trophic effects on duodenal mucosa were investigated by morphometry and determination of brush border enzyme activity. Results were compared intraindividually before and after S.b. In intestinal lymphocytes no phenotypic changes were observed. CD4+ cells of the peripheral blood had a significantly increased expression of CD25 (p < 0.02). None of twelve volunteers had an increase in villous surface area (n.s.). Immunoglobulin A content in small intestine secretion was unaltered. An increase in brush border enzyme activity of lactase, alpha-glucosidase, and alkaline phosphatase was observed (p < 0.01). Our findings indicate that S.b. has a positive effect on the maturation of enterocytes and only a minor influence on lymphocytes.

The serine protease inhibitor diisopropylfluorophosphate inhibits neutrophil NADPH-oxidase activity induced by the calcium ionophore ionomycin and serum opsonised yeast particles

The effect on human neutrophil NADPH-oxidase activity of the serine protease inhibitor diisopropylfluorophosphate (DFP) was investigated. Pretreatment of neutrophils with the protease inhibitor did not affect the release of reactive oxygen species induced by fMLP. However, the intracellular production of reactive oxygen species induced by ionomycin and yeast particles was largely inhibited in DFP treated cells. Production of reactive oxygen species in subcellular fractions was not affected by the protease inhibitor, neither when the plasma membrane nor when the specific granules were used as source for the b cytochrome subunit of the oxidase. This shows that DFP does not affect the assembly of the oxidase or the activity of the assembled complex. We suggest that serine protease activity is of importance for the signal(s) induced by the Ca2+ ionophore and the yeast particles to reach the dormant NADPH oxidase present in the specific granules and phagolysosomes.

Effects of a colostrum substitute and of dietary brewer's yeast on the health and performance of dairy calves

We tested the effects of substituting a whey protein concentrate for dam's colostrum at first feeding and of 1% brewer's yeast in dry feed on calf health and performance. Eighty-four calves were assigned to four preweaning and eight postweaning treatments based on feeding either dam's colostrum or a whey protein concentrate at birth and either yeast or no yeast in the dry feed both before and after weaning. After the first feeding, all calves were fed colostrum through 4 d of age and an all milk protein milk replacer from d 5 to 46 of age. Daily feed intakes, health measurements, and weekly BW were recorded. Calves fed whey protein concentrate at birth had similar health parameters and greater feed efficiency than calves fed colostrum over the preweaning period. Addition of 1% brewer's yeast to the dry feed apparently reduced the incidence of fever and the number of associated antibiotic treatments during the preweaning period, but had no effects thereafter. Under the conditions of this study, whey protein concentrate was an effective substitute for dam's colostrum at first feeding, and 1% brewer's yeast fed in dry feed may reduce susceptibility to infection prior to weaning.

The influence of "selenium organicum" upon the hepatic function of carbon tetrachloride poisoned rats

The hepatoprotective action of the Romanian preparation Orgasel containing selenium (Se) 5.01 mg/100 g autolysated yeast powder, was tested on adult Wistar rats poisoned with carbon tetrachloride (CCl4). The hepatotoxic agent (a 20% CCl4 solution in oil) was administered i.p. in a single dose of 0.3 ml CCl4 solution/100 g body weight, and the preparation tested (autolysate of seleniated yeast) was administered by gavage in 4 doses (of 100 mg Se powder/100 g animal each) along 2 days. After 48 hrs the animals were sacrificed, then their blood and liver were collected. The treatment with Orgasel significantly reduced the organs, morphological changes (fat liver degeneration, splenomegaly, testicle degeneration) induced by CCl4 poisoning in the rat, an effect found also at the biological parameters levels studied in plasma and liver. In the plasma, the high lipid peroxide concentrations, the increased activity of alkaline phosphatases, and the reduced antioxidative activity generated by CCl4 have been statistically significant brought to the normal range after Orgasel administration. At the liver this treatment significantly decreased the lipid peroxides production, the total lipids and cholesterol concentrations, and statistically significant increased the enzymes activity (alkaline phosphatases, GPT). The results obtained after Orgasel administration proved that this preparation has a global beneficial action upon the organism in the poisoned rat, as well as a strong antioxidative effect, confirming once again the essential role of Se in maintaining cells' integrity.

Bovril and moclobemide: a novel therapeutic strategy for central autonomic failure

The consumption of tyramine-containing foods is contraindicated in patients on classic monoamine oxidase (MAO) inhibitors. We report successful therapeutic use of moclobemide (a MAO-A selective inhibitor) plus controlled amounts of Bovril (a tyramine-rich yeast-extract available as a food) in a patient with pure central autonomic failure who was rendered bed-bound by severe postural hypotension. Standing blood pressure is now at least 90/45 mm Hg. The selectivity of moclobemide allows about a tenth of ingested tyramine to reach nerve endings and thus the modest hypertensive effect of this combination re-established day-to-day function by restoring normotension.

Effect of hydromechanical forces on the production of filamentous haemagglutinin and pertussis toxin of Bordetella pertussis

The production of Bordetella pertussis extracytoplasmic filamentous haemagglutinin (FHA) and pertussis toxin (PT) in a bioreactor under stirring conditions was studied in order to investigate the effect of hydromechanical forces on yields of both antigens. It was shown that FHA loses its haemagglutinin activity when the power transmitted by the agitator and the aerator per unit volume increases, whereas PT production is not affected. The loss of FHA activity can be explained by the action of shear forces on the filamentous structure of this antigen.

Kinetics of drug action in disease states. XXXVIII: Effect of body temperature on the convulsant activity of pentylenetetrazol in rats

The purpose of this investigation was to determine the effect of body temperature on the pharmacodynamics (convulsant activity) of pentylenetetrazol (PTZ). Rats received an iv infusion of PTZ until the onset of maximal seizures, at which time samples of cerebrospinal fluid (CSF), brain, and blood (for serum) were obtained for subsequent determination of PTZ concentrations by HPLC. The PTZ infusion caused a decrease in body temperature of approximately 4 degrees C within 20 min and onset of seizures in approximately 40 min. Compared with animals whose temperature was maintained in the normal range by heating pads, the hypothermic rats required significantly larger doses and higher serum, brain, and CSF concentrations of PTZ to produce seizures. Other rats received an injection of brewer's yeast to produce fever. Then, PTZ was infused 6, 12, or 24 h later when body temperature was elevated by an average of 1.3, 1.1, or 0.4 degrees C, respectively. Compared with control rats, whose temperature was maintained in the normal range by heating pads, moderate hyperthermia had no significant effect on the dose and concentrations of PTZ required to produce maximum seizures. Pentylenetetrazol exemplifies a drug that can produce hypothermia which, in turn, reduces the sensitivity of rats to its pharmacologic action. Unlike the central nervous system (CNS) depressants phenobarbital and ethanol, whose pharmacologic activity in rats is enhanced at elevated body temperature, the activity of the CNS stimulant PTZ is apparently not altered by fever.

A fraction derived from brewer's yeast inhibits cholesterol synthesis by rat liver preparations in vitro

Brewer's yeast was grown on a defined medium containing tracer 51Cr with or without added chromium. The two batches of yeast contained 10 microgram/g (high-Cr) or 80 ng/g (low-Cr). Extracts were prepared and fractionated. A third batch of yeast (third batch) was grown with added Cr, and fractionated. Rats were reared on either rat cubes (normal diet) or on a low-Cr diet (low-Cr), or on rat cubes with added cholestyramine (cholestyramine diet). Preparations of rat liver, both cell-free and intact hepatocytes, incorporated acetate-carbon into fatty acids and cholesterol. These processes were inhibited by a yeast fraction containing small, neutral, water-soluble compounds. The degree of inhibition was the same whether the liver came from normal rats or rats fed on the low-Cr diet. Similarly the inhibitory effect was found with identical amounts of extracts from low- or high-Cr yeasts. Therefore, Cr compounds do not appear to account for the inhibitory effects of brewer's yeast. Use of other substrates indicated that the site of inhibition of sterol synthesis was apparently between acetyl-CoA and mevalonate. One inhibitory substance was isolated from yeast and was found to be nicotinamide riboside. This may have been produced from NAD(P) during the preparation of yeast extracts, and it may be produced from dietary yeast supplements during digestion in vivo. Nicotinamide riboside may be partly responsible for the reported effects of yeast supplements on plasma lipids in humans.

[The metabolic efficiency of baker's yeast in an atherogenic diet]

The effect of bakery compressed yeasts in the amounts of 6 and 12 g/100 g of the ration was studied in rats. It was revealed that 12 g of yeasts per 100 g of the atherogenic ration produced a hypocholesterolemic effect. A negative effect of this amount of the yeasts was manifest in the slow growth of the rats' body mass and in an increased ratio of the kidney/body mass. The yeasts amounts used did not protect the test animals from the kidney infiltration with lipids and cholesterol; 12 g of yeasts per 100 g of the ration promoted elevation of sialic acid content in the blood plasma. Morphologic changes were observed only in the aortal wall, they were characteristic of the prelipid stage of atherosclerosis and did not depend on the yeasts amount.

Development of improved media for axenic cultivation of Acanthamoeba culbertsoni, Singh and Das 1970

Several varieties of peptone supported growth of A. culbertsoni to different extents reaching a maximum cell density of 1-2 X 10(6)/ml. Proteose peptone and tryptone also yielded good growth when combined with thiamine and vitamin B12. A combination of proteose peptone with glucose, yeast extract and salts promoted excellent growth of A. culbertsoni with cell density reaching 1-2 X 10(7) cells/ml; tryptone and one of the indigenous peptones also yielded comparable growth when substituted for proteose peptone in this medium. Casamino acids also supported good growth of amoebae and requirement of yeast extract could be met by a combination of thiamine, vitamin B12 and biotin. Bacto peptone did not support good growth of this amoeba but supplementation of peptone with casamino acids or amino acid mixture improved the growth supporting capacity of the medium. Development of several media with or without glucose will aid in cultivation of A. culbertsoni, studies on its metabolism as well as screening of potential drugs.

[The effect of microbial protein from a hydrocarbon base (fermosin) with a defined fatty acid composition on fat metabolism and fat composition in slaughter animals. 2. The effect of "fermosin" on the composition of back fat in hogs]

Two tests have been undertaken to investigate the influence of feeding microbial biomasses to pigs. No alterations of the fat parameters characterizing the fat stability were observed. All the values obtained are in a normal range. Increases in heptadecenic acid were detected dependent on the content of microbial biomasses in the feed and its fat content. The alterations are mainly in a normal range or slightly beyond it. In nature odd-numbered fatty acids are ubiquitous. Uptake and storage suggest that the organism reacts to an increased offer of C17-fatty acids with an accelerated decomposition of these fatty acids or/and with inhibition of their endogenous synthesis. The results are discussed in comparison with those of literature.

[The effect of microbial protein, obtained on a hydrocarbon base (fermosin), with a defined fatty acid composition on fat metabolism and fat composition in slaughter animals. 1. The effect of fermosin on the composition of broiler depot fat]

A study has been undertaken to investigate the influence of fermosin on the depot-fat composition of broilers and the oxidative stability of these fats in parallel with test animals fed yeast conventional produced on carbohydrate base. The data obtained are discussed with reference to literature.

Comparison of whole blood selenium values and erythrocyte glutathione peroxidase activities of normal individuals on supplementation with selenate, selenite, L-selenomethionine, and high selenium yeast

The selenium levels and the glutathione peroxidase activity GSH-PX of whole blood and of erythrocytes, respectively, were determined in 139 normal Danes and related to sex and smoking habits. No differences were found in relation to sex apart from a higher GSH-PX activity of females when assayed with tertiary butyl hydroperoxide. Smokers showed significantly lower selenium values than non-smokers (p less than 0.05), but the two groups had identical GSH-PX activities. Individuals from the above-mentioned group were divided into four groups, receiving daily oral doses of 200 micrograms of selenium in the form of selenite, selenate, L-selenomethionine, and selenium as contained in yeast. Whole blood selenium values and the erythrocyte glutathione peroxidase activities were determined during three months of supplementation followed by a withdrawal period of four months. Both the inorganic selenium compounds and the organic derivatives gave rise to steady state levels of GSH-PX after one month of supplementation. However, the selenium levels in the groups receiving organic selenium showed a steady rise during the whole period, whereas those supplemented with inorganic selenium leveled off after a period of one to three months. The data for smokers and nonsmokers revealed identical results when organic selenium was supplemented. However, selenite gave rise to significantly higher selenium levels and GSH-PX activities in smokers than in non-smokers. Less significant (p less than 0.08) elevations of both parameters were also observed among the smokers in the selenate group. By taking both the selenium level and the GSH-PX activity into consideration, organic selenium (i.e., L-(+) selenomethionine) was judged to be more bioavailable than selenite and selenate.

Controlled evaluation of trypticase soy broth with and without gelatin and yeast extract in the detection of bacteremia and fungemia

The addition of gelatin to blood culture media has been suggested to prevent the inhibition of Neisseria meningitidis, Neisseria gonorrhoeae, Gardnerella vaginalis, and Peptostreptococcus anaerobius that is caused by sodium polyanetholsulfonate. To determine the effect of such supplementation on the overall yield of microorganisms, we compared the yield and speed of detection of clinically important microorganisms from 5422 paired 10-ml samples of blood cultured in Trypticase soy broth (TSB) containing 0.03% sodium polyanetholesulfonate (SPS) and TSB/SPS containing 1.2% gelatin and 1.0% yeast extract (mTSB). The atmosphere of incubation (open venting unit) and ratio of blood to broth (1:5) were the same for both samples. Only cultures with adequate blood sample (greater than or equal to 80% of stated volume) were compared statistically. Addition of gelatin and yeast extract resulted in inhibited growth of Enterobacteriaceae (p less than 0.001), Pseudomonas aeruginosa (p less than 0.01), fungi (p less than 0.05), and the overall set of microorganisms encountered (p less than 0.001). It delayed growth of Enterobacteriaceae (p less than 0.001) but reduced the time to recover staphylococci (p less than 0.02). Of 12 isolates of species usually inhibited by SPS, seven grew only with the addition of gelatin and yeast extract, none grew only without supplementation, and five grew in both media. Although gelatin and yeast extract may improve the yield of some specific bacteria, the routine use of these additives cannot be recommended for all blood culture media.

Development of a system for evaluating 5-lipoxygenase inhibitors using human whole blood

A reliable system for evaluating 5-lipoxygenase (5-LO) pathway inhibitors employing human whole blood stimulated by the calcium ionophore, A-23187, and yeast cell walls (YCW) is described. In developing this system, we have shown that leukotriene B4 (LTB4) and 5-hydroxyeicosatetraenoic acid (5-HETE) can be recovered quantitatively from whole blood, and can be measured with accuracy and a precision (standard deviation) of +/- 12%. Apparent differences in LTB4/5-HETE levels between donors can be minimized by normalizing the LTB4/5-HETE production to neutrophil number. Variability in LTB4/5-HETE production among different donors was reduced by increasing the ionophore concentration. The kinetics of ionophore stimulated product production display a 1-4 min lag which is dependent on ionophore concentration. The lag is removed by pretreatment of blood with 5 micrograms/ml cytochalasin B. Likewise, the kinetics of product formation after stimulation with yeast cell walls demonstrated a lag period, which could be shortened by prior opsonization of the YCW. The amount of LTB4 metabolism to 20-OH-LTB4 and 20-COOH-LTB4 in this system is approximately 20%. Phenidone, nordihydroguaiaretic acid, and nafazatrom, known inhibitors of the 5-LO pathway, display half-maximal inhibition points of 0.4, 1.5, and 9 micrograms/ml, respectively. In summary, we believe that this assay offers a guide for predicting systemic levels of drug needed to be achieved for effective inhibition of cellular LTB4/5-HETE synthesis/release in humans.

In vitro cytolysis of MM46 tumor cells by mouse phagocytes activated by acidic mannan fraction of bakers' yeast

An acidic mannan from bakers' yeast designated as WAM025 was investigated for its augmentative effect on cytolytic activity of phagocytes obtained from the peritoneal cavity of C3H/He strain mice, which had been administered i.p. with this acidic polysaccharide, 150 mg/kg/d, 5 and 10 times. The result of assay for the cytolytic effect of WAM025-activated phagocytes by measuring the amounts of 3H-uridine of the MM46 tumor cells indicated that a marked lysis of the target cells took place by a 24-h incubation with the activated phagocytes and that a decrease of this effect was observed by the additions of either phagocytic inhibitors or active oxygen scavengers. Because generation of active oxygens from the WAM025-activated phagocytes was also diminished by the additions of the same inhibitors and scavengers, it indicated that active oxygens participated in an important role in the cytolytic effect displayed by the WAM025-activated phagocytes.

Failure of brewer's yeast as a repellent to fleas on dogs

Active and inactive brewer's yeast, when given as a dietary supplement to dogs at the rate of 14 g/day, failed to repel or kill fleas. Twenty dogs in each of 3 groups were inoculated weekly for 7 weeks with 100 unfed cat fleas (Ctenocephalides felis). One group served as a control while one group received inactive and the other active yeast during the last 5 weeks of the trial. There were no significant differences in flea counts among the 3 groups during the first 4 weeks of yeast supplemental feedings. Total flea counts during the 5th week of yeast supplementation did not differ significantly from the counts on control dogs, although there was a significant difference between counts from dogs receiving active and those receiving inactive yeast.

Lipases production by Bacillus circulans under mesophilic and osmophilic conditions. Factors affecting lipases production

A facultative osmophilic bacterium able to produce lipases (isolated from bee honey) was identified as Bacillus circulans. Factors affecting lipases production by such isolate were studied. Dox's liquid medium supplied with 2 and/or 30% sucrose was used as a basal medium, under static culture condition, for such a purpose. Results have showed that the optimal sucrose concentration at which the isolate produced its maximal yield of lipases was 30% after an incubation period of 24 hours at 40 degrees C, and this was corresponding to an incubation period of 48 hours at 40 degrees C in presence of 2% sucrose. The optimal pH value was 7 in the first case while, 6.5 in the second. Furthermore production of extracellular lipases by such isolate was achieved in presence and absence of tributyrin as a carbon source instead of sucrose when supplied to Dox's liquid medium. Also the production of extracellular lipases by such isolate was not enhanced in presence of tributyrin as a supplement to Dox's liquid medium when supplied with 2 and/or 30% sucrose as carbon sources. This might suggest that the extracellular lipases of such isolate is constitutive in nature.

Effects of chromium and yeast supplements on carbohydrate and lipid metabolism in diabetic men

Diabetes mellitus has been shown to develop as a consequence of chromium (Cr) deficiency in experimental animals and in humans sustained by prolonged total parenteral nutrition. Prior limited trials in humans had indicated that Cr supplements, in either inorganic or organic form, may improve carbohydrate utilization. We report here a clinical double-blind, random crossover trial of inorganic Cr trichloride, a brewer's yeast that contained Cr as glucose tolerance factor (GTF), a brewer's yeast extract without GTF, and a placebo. Forty-three outpatient diabetic men received three of these supplements for 4 mo each. Subgroups included 21 ketosis-prone men; 7 ketosis-resistant, nonobese men; and 15 ketosis-resistant obese men. Chromium levels were followed pre- and posttreatment in hair, red blood cells, plasma, and urine. Response of carbohydrate metabolism to treatment was assessed in terms of change in insulin requirements, fasting plasma glucose, plasma cholesterol, and triglycerides, as well as change in plasma glucose, glucagon, and insulin or C-peptide levels in response to a standard meal. In some men, these parameters were also measured after i.v. tolbutamide. Both the inorganic and organic oral Cr supplements increased measurable body pools of Cr in hair and red blood cells by about 25%. However, fasting plasma glucose and lipids and the glucose response to either the standard meal or to tolbutamide were not significantly altered by any of the treatments. Despite this lack of effect on carbohydrate levels, the ketosis-resistant subgroups demonstrated a significant increase in postprandial insulin after treatment with the brewer's yeast that contained GTF.

Relationship of yeast-injection induced changes in brain met-enkephalin and analgesia

Subplantar injection of Brewer's yeast induces a hyperalgesia that is associated with an increase in the level of striatal Met-enkephalin (ME); there was no change in the hypothalamus of periaqueductal gray. To test the relationship between striatal ME and analgesia, naloxone (10, 3, 0.5 mg/kg, SC) or thiorphan (100 micrograms, ICV) were administered. Neither drug caused a potentiation or a reduction in the hypersensitivity. These data suggest that an increase in striatal does not result in altered pain sensitivity in this model.