Supplemental ß-carotene I: effect on plasma vitamin A, growth, performance, and carcass characteristics of feedlot cattle.

To evaluate the effects of ß-carotene (ßC) on performance and carcass characteristics, 112 crossbred calves were allotted to 4 treatments consisting of retinyl palmitate (RP) supplemented at 2200IU/kg, and synthetic ß-carotene supplemented at 1 (SßC1X), 5 (SßC5X), or 10 (SßC10X) times RP. Compared to RP, SßC1X did not impact performance (P≥0.25) or plasma concentrations of retinoids or carotenoids (P≥0.26). Increasing dietary ßC increased (P≤0.04) plasma concentrations of RP and all of the isomers of ßC, but did not affect weight, gain, or gain:feed (P≥0.24). Marbling and fat thickness did not differ between RP and SßC1X or because of amount of ßC (P≥0.35). Lightness (L*) of LM decreased with increasing concentration of SßC (linear; P=0.01). Yellowness (b*) increased (P=0.04) and redness (a*) tended to increase (P=0.09) in subcutaneous fat as SßC amount increased (quadratic).

Effect of decreasing dietary cation anion difference on feedlot performance, carcass characteristics, and beef tenderness.

The manipulation of acid-base balance has been extensively investigated as a means of manipulating Ca homeostasis and managing milk fever in dairy cows. A low dietary cation anion difference (DCAD) increases urinary Ca, blood-ionized Ca, and responsiveness to Ca-homeostatic hormones. Very little attention has been focused on the possibility of using a low dietary DCAD to increase muscle Ca availability, calpain activity, and meat tenderness of beef cattle. Thus, 90 Angus × Simmental crossbred steers were allotted by weight (590.1 ± 2.4 kg) and breed composition (% Simmental) to 3 treatments (6 pens/treatment, 5 steers/pen) to evaluate the effects of DCAD on beef tenderness. Treatments were initiated 2 wk before slaughter and consisted of 3 DCAD (mEq/100 g) treatments: -16, 0, and +16. Basal diets (DM basis) were 62 to 64% corn, 6 to 9% soybean meal, and 20% corn silage, and were formulated to contain similar concentrations of protein, energy (NEm; NEg), and minerals, with the exception of sodium and chlorine. A commercial chloride ion supplement (PASTURChlor, West Central, Ralston, IA) was added to diets to decrease DCAD and sodium bicarbonate was added to diets to increase DCAD. Performance before initiation of the study did not differ among treatments (P > 0.22). Urine pH did not differ at the initiation of the study (P > 0.57), but did increase at a decreasing rate on d 7 (6.37, 7.69, 8.13) and d 14 (5.68, 7.66, 8.03) of the study as DCAD increased from -16 to 0 to +16, respectively (quadratic, P < 0.02). Gain and gain:feed responded quadratically to DCAD (P < 0.01), increasing from -16 to 0 DCAD and decreasing from 0 to +16 DCAD. Hot carcass weight, dressing percent, fat thickness, LM area, yield grade, marbling score, quality grade distribution, 48 h muscle pH, and Ca content of muscle did not differ among treatments (P > 0.16). In addition, DCAD did not affect Warner-Bratzler shear force among treatments after 7 and 21 d of aging (P > 0.23). Although urine pH was decreased by feeding a -16 DCAD diet, Ca influx into the LM and beef tenderness were not affected by altering the DCAD in finishing beef cattle diets.

Supplemental vitamin D3 and zilpaterol hydrochloride. I. Effect on performance, carcass traits, tenderness, and vitamin D metabolites of feedlot steers.

Angus × Simmental steers (n = 210; initial BW 314 ± 11 kg) were separated into heavy and light BW blocks and allotted evenly by BW to 6 treatments (3 heavy and 2 light pens per treatment) to determine the effect of supplemental vitamin D3: 0 IU (no D), 250,000 IU for 165 d (long-term D), or 5 × 10(6) IU for 10 d (short-term D) on performance, carcass traits, vitamin D metabolites, and meat tenderness in steers fed either 0 (NZ) or 8.38 mg/kg zilpaterol hydrochloride (ZH) daily for 21 d. Placebo or ZH was added to the diet 24 d, and short-term D was added 13 d before slaughter. Vitamin D3, ZH, and placebo were all removed from the diet 3 d before slaughter. Steers fed ZH tended to have improved overall G:F compared with steers not fed ZH (P < 0.09). Overall performance was not affected by long-term D, with or without ZH (P = 0.11) compared with no D, with or without ZH. Short-term D decreased final BW, ADG, and G:F (P = 0.04) compared with no D, when ZH was not fed. Zilpaterol hydrochloride increased HCW, dressing percentage, and LM area (P < 0.01); and decreased fat thickness, yield grade, and marbling (P < 0.03). Carcass traits were not impacted by long-term D without ZH (P > 0.13), but long-term D with ZH decreased percentage KPH (P < 0.02). Compared with no D, short-term D tended to decrease HCW (P < 0.07), decreased fat thickness (P < 0.01), and tended to increase dressing percentage (P < 0.10) when ZH was not fed, yet did not impact carcass traits when ZH was fed (P < 0.13). Feeding ZH tended to decrease (P < 0.09) LM 1,25-dihydroxyvitamin D3 [1,25(OH)2D3]. The long-term D treatment increased LM vitamin D3 and 25-hydroxyvitamin D3 (25OHD3) 18- and 5-fold, respectively, when ZH was not fed (P < 0.04) and increased LM 25OHD3 by 4-fold when ZH was fed (P < 0.01). Short-term D increased LM vitamin D3 and 25OHD3 by 52- and 9-fold, respectively, when ZH was not fed (P < 0.01), and by 24- and 9-fold, respectively, when ZH was fed (P < 0.01). Also, short-term D increased LM 1,25(OH)2D3 by 2-fold (P < 0.04) when ZH was fed. Warner-Bratzler shear force (WBSF) was greater for ZH steaks than non-ZH steaks at 7, 14, and 21 d postmortem aging (P < 0.01). Vitamin D did not reduce WBSF (P = 0.18). When ZH was fed, long-term D tended to increase WBSF in steaks aged 21 d (P = 0.06). In conclusion, ZH improved carcass leanness and decreased tenderness, and vitamin D feeding increased vitamin D3 metabolites in LM, but did not improve tenderness in steers fed ZH.

Supplemental vitamin D3 and zilpaterol hydrochloride. II. Effect on calcium concentration, muscle fiber type, and calpain gene expression of feedlot steers.

Two hundred and ten Angus × Simmental steers (initial BW 314 ± 11 kg) were separated into heavy and light BW blocks and allotted evenly by BW to 6 treatments (3 heavy and 2 light pens per treatment) to determine the effect of supplemental vitamin D3: 0 IU (no D), 250,000 IU for 165 d (long-term D), or 5 × 10(6) IU for 10 d (short-term D) on plasma and muscle calcium concentrations and gene expression in steers fed either 0 (NZ) or 8.38 mg/kg (ZH) zilpaterol hydrochloride (ZH) daily for 21 d. Placebo or ZH was added to the diet 24 d, and short-term D was added 13 d before slaughter. Treatments were removed from all diets 3 d before slaughter. Plasma total calcium (Ca(2+)) was determined at study initiation, start of ZH and short-term D feedings, and at vitamin D3 and ZH withdrawal. Both plasma total and ionic Ca(2+) were determined when animals were sent to harvest. Longissimus muscle total and ionic Ca(2+) were determined in meat aged 7 and 4 d postmortem, respectively. When ZH was fed, long-term D decreased plasma total Ca(2+) at slaughter (P < 0.04). Short-term D increased (P < 0.01) plasma total and ionic Ca(2+) at slaughter regardless of ZH inclusion in the diet. Long- and short-term D, with or without ZH, did not affect (P > 0.28) LM total Ca(2+); however, both long- and short-term D increased LM ionic Ca(2+) when ZH was not fed (P < 0.01). Long-term D reduced LM ionic Ca(2+) when ZH was fed (P < 0.02). Neither long- nor short-term D affected PPARα or δ gene expression (P = 0.19) whether or not ZH was fed. Expression of MYH1 and 2A (P < 0.05) but not 2X (P = 0.21) was decreased in steers fed ZH. Long-term D had no effect on MYH2A expression (P = 0.21). Short-term D increased MYH2A expression when ZH was not fed (P < 0.03). Calpain mRNA tended to be lower in steers fed ZH (P = 0.09), but was not affected by long- or short-term D regardless of whether or not ZH was fed (P = 0.39). Expression of calpastatin did not differ with vitamin D supplementation (P = 0.35). In conclusion, ZH decreased oxidative myosin expression, and when combined with long-term D, ZH decreased LM ionic Ca(2+). Moreover, vitamin D3 supplementation did not increase calpain mRNA. These results help explain why vitamin D3 does not improve tenderness in steers fed ZH.

Effect of increasing distillers grains inclusion on performance and carcass characteristics of early-weaned steers.

Dried distillers grains with solubles (DDGS) contain elevated concentrations of CP, oil, and S, which can negatively impact performance and carcass characteristics in steers weaned at 205 d of age. Early weaned (EW) cattle, however, consume less DM and require increased CP. Furthermore, the energy required to dispose of excess N may actually decrease excessive fat accumulation, which can occur in EW cattle. Thus, we hypothesized that feeding diets with increased concentrations of DDGS to EW steers for the first 99 d would decrease fat thickness and increase harvest weights, and would not inhibit performance or marbling deposition. To test this hypothesis, 90 Angus × Simmental steers (199.7 ± 12.2 kg) were weaned at 134 d of age (EW) and allotted to 3 high concentrate diets (20% corn silage) containing either 0%, 30%, or 60% DDGS (15.7%, 15.8% and 21.7% CP, respectively). Dietary treatments were fed for 99 d, after which steers were placed on a common diet containing no DDGS (12.9% CP) until harvest at a common weight of 599 kg. Concentration of dietary DDGS did not affect ADG, DMI, or G:F during the growing phase (P > 0.41), did not produce any carryover effects on ADG, DMI, or G:F during the finishing phase (P > 0.26), and resulted in similar overall performance (P > 0.52). Dressing percentage (P < 0.05), HCW (P = 0.06), fat thickness (P = 0.10), and % KPH (P = 0.08) responded quadratically to early DDGS supplementation, increasing from 0 to 30% DDGS inclusion and decreasing from 30 to 60% DDGS inclusion, respectively. Marbling score was not affected (P > 0.46) by DDGS inclusion, but there was a tendency (P = 0.08) for the ratio of subcutaneous (SC) to intramuscular (IM) fat to be altered by DDGS inclusion. The ratio of IM to SC fat decreased from 0 to 30% DDGS inclusion and increased from 30 to 60% DDGS inclusion. These data suggest that inclusion of increased concentrations of dietary DDGS early in the feedlot phase does not negatively impact growth and performance of EW cattle, but does partition energy from carcass to noncarcass components. However, increased concentrations of DDGS did not negatively impact IM fat deposition. Utilization of energy for disposal of excess N may be responsible for changes in carcass weight and SC fat deposition.

Biologically active bisbenzylisoquinoline alkaloids from the root bark of Epinetrum villosum.

Methanol and water extracts of the root of Epinetrum villosum (Exell) Troupin (Menispermaceae) were found to exhibit antimicrobial and antiplasmodial activities. Investigation of the active methanol fraction led to the isolation of four bisbenzylisoquinoline alkaloids, i.e., cycleanine, cycleanine N-oxide, isochondodendrine and cocsoline. Structures were established by spectroscopic methods. Cocsoline displayed antibacterial and antifungal activities (MIC values of 1000-15.62 and 31.25 microg/ml, respectively). Isochondodendrine was found to have the most potent antiplasmodial activity (IC50 = 0.10 microg/ml), whereas the IC50 on HCT-116 human colon carcinoma cells was 17.5 microg/ml (selectivity index 175). Cycleanine acted against HIV-2 (EC50=1.83 microg/ml) but was at least 10-fold less active against HIV-1. Cycleanine N-oxide showed no activity towards all tested microorganisms.

Cycloabyssinone, a new cycloterpene from Harrisonia abyssinica.

A new cycloterpene, 4beta,14-dimethyl-9,19-cyclo-5alpha,9beta-ergost-24(28)-en-3-one (cycloabyssinone) (1), and a known terpene, 3-friedelanone, were isolated from stem bark of Harrisonia abyssinica and identified by spectroscopic methods.

Steroids from Harrisonia abyssinica.

In addition to the known sterols and ketosteroids beta-sitosterol (24 alpha-ethylcholest-5-en-3 beta-ol), stigmasterol (24 alpha-ethylcholesta-5,22-dien-3 beta-ol), campesterol (24 alpha-methylcholest-5-en-3 beta-ol), beta-sitostenone (stigmast-4-en-3-one, 24 alpha-ethylcholest-4-en-3-one), stigmastenone (stigmasta-4,22-dien-3-one, 24 alpha-ethylcholesta-4,22-dien-3-one), campestenone (24 alpha-methylcholest-4-en-3-one), and stigmasta-3,5-dien-7-one (24 alpha-ethylcholesta-3,5-dien-7-one), the new steroids stigmasta-3,5,22-trien-7-one (24 alpha-ethylcholesta-3,5,22-trien-7-one), and campesta-3,5-dien-7-one (24 alpha-methylcholesta-3,5-dien-7-one) were isolated from the stem bark of Harrisonia abyssinica and identified by NMR and mass spectrometry.

New acylated triterpenoid saponins from Maesa lanceolata.

Ten new acylated triterpenoid saponins were isolated from the leaves of Maesa lanceolata. For their structure elucidation extensive use was made of homo- and heteronuclear 2D NMR techniques such as COSY, NOESY, HSQC and HMBC. All saponins identified contained the same tetraglycosidic side chain, but the triterpenoid moiety showed a variable esterification pattern. Monoester, diester and triester derivatives were present. Maesasaponin I was a 21-monoester derivative, i.e. ¿3 beta-O-[alpha-L-rhamnopyranosyl-(1-->2)-beta-D-galactopyranosyl- (1-->3)]-[beta-D-galactopyranosyl-(1-->2)]-beta-D-glucuronopyranosyl+ ++¿-21 beta-angeloyloxy-13 beta, 28-oxidoolean-16 alpha, 22 alpha, 28 alpha-triol. Maesasaponins III, IV3, V3 and VI2 had an additional acetyl, propanoyl, n-butanoyl and angeloyl substituent, respectively, in position 22. Maesasaponins II, IV2, V2, VI3 and VII1 were characterised as the 16-acetyl derivatives of maesasaponins I, III, IV3, V3 and VI2, respectively. Structures of saponins previously reported in M. lanceolata had to be revised.

Complement-inhibiting cucurbitacin glycosides from Picria fel-terrae.

Four cucurbitacin glycosides were isolated from Picriafel-terrae and identified by MS and NMR spectroscopy as picfeltarraenin IA (1), picfeltarraenin IB (2), picfeltarraenin IV (4), and a new compound picfeltarraenin VI (3) (picfeltarraegenin I 3-O-beta-D-xylopyranoside). All four compounds acted as inhibitors on both the classical and alternative pathways of the complement system, with compound 3 exhibiting the highest inhibitory activity (IC50 29 +/- 2 microM and 21 +/- 1 microM, respectively). Compounds 1-4 showed no antiviral, antibacterial, or antifungal activities. Picfeltarraenin IA and IB were tested in an in vitro human tumor cell line panel, but displayed no cytotoxic activity.

Complement-modulating properties of a kaempferol 7-O-rhamnosylsophoroside from the leaves of Morinda morindoides.

A kaempferol 7-O-rhamnosylsophoroside isolated from the leaves of Morinda morindoides showed dose-dependent complement-modulating properties towards both the classical (inhibiting effect) and alternative (activating effect) pathways of the complement system. Its structure was elucidated by chemical and spectroscopic methods as kaempferol 7-O-[alpha-L-rhamnopyranosyl-(1-->6)]-[beta-D-glucopyranosyl-(1-->2)]-be ta-D-glucopyranoside, a new natural product which was named morindaoside.

Adenosine-1 active ligands: cirsimarin, a flavone glycoside from Microtea debilis.

Several plants collected through different approaches were screened on distinct receptors using ligand-binding studies as bioassay. Extracts of Microtea debilis showed high activity on adenosine A1 receptors. Bioassay-guided fractionation using ligand-binding studies resulted in the isolation of an adenosine A1 active ligand, cirsimarin (cirsimaritin 4'-O-glucoside). GTP did not influence the radioligand inhibition curve of cirsimarin, indicating that this compound is acting as an antagonist at the adenosine-A1 receptors. The use of this plant against "proteinuria" in traditional medicine in Suriname (South America) may be explained by the adenosine A1 antagonistic action of cirsimarin. A series of flavonoids was tested in the same assay, but they were less active. No structure-activity relationship could be observed.

In vitro biological activities of alkaloids from Cryptolepis sanguinolenta.

In our biological screening of higher plants, an aqueous and an 80% EtOH extract from the root bark of Cryptolepis sanguinolenta showed potent antibacterial, anticomplementary, and moderate antiviral activities, but no antifungal effect could be detected. Bioassay-guided fractionation of the 80% EtOH extract led to the isolation of three alkaloids: quindoline (1), hydroxycryptolepine (2), cryptolepine.HCl (3), and the corresponding base cryptolepine (4). All compounds strongly inhibited the growth of Gram-positive bacteria (MIC < or = 100 micrograms/ml) and showed a moderate (MIC = 125 or 250 micrograms/ml), a weak (MIC = 500 micrograms/ml), or no activity (MIC > 500 micrograms/ml) against selected Gram-negative bacteria. They also possessed a bactericidal effect depending on the bacterial strain. Compounds 1, 2 and 3 displayed a dose-dependent inhibitory effect on the classical pathway of the complement system while compounds 2 and 3 activated the alternative pathway, except for compound 1. Compound 3 was found to possess an antiherpetic activity. Compounds 1 and 4 showed no antiviral effect, but were quite cytotoxic in the antiviral test system down to a concentration of 1 microgram/ml.

Triterpenoid saponins from Maesa lanceolata.

Six new homologous triterpenoid saponins were isolated from the methanol extract of the leaves of Maesa lanceolata and characterized as 3 beta-O-[alpha-L-rhamnopyranosyl(1 --> 2)-beta-D-galactopyranosyl (1 --> 3)]-[beta-D-galactopyranosyl(1 --> 2)]-beta-D-glucuronopyranosides alpha-diol, 22 alpha-angeloyloxy-16 alpha-butanoyloxy-13 beta,28-oxydoolean-21 beta,28 alpha-diol, 16 alpha,22 alpha-diangeloyloxy-13 beta,28-oxydoolean-21 beta,-28 alpha-diol, 22 alpha-angeloyloxy-13 beta,28-oxydo-16 alpha-(2-methyl-butanoyloxy)-olean-21 beta,28 alpha-diol, 21 beta-acetoxy-22 alpha-angeloyloxy-13 beta,28-oxydo-16 alpha-propanoyloxyolean-28 alpha-ol, 21 beta-acetoxy-22 alpha-angeloyloxy-16 alpha-butanoyloxy-13 beta,28-oxydoolean-28 alpha-01. The structures were established on the basis of chemical and spectral evidence.

Antibacterial and molluscicidal phenolic acids from Spondias mombin.

Spondias mombin L. (Anacardiaceae), used in traditional medicine because of its antimicrobial properties, was found to contain a series of 6-alkenyl-salicylic acids. They were isolated from the ethanolic extract of leaves and stems of Spondias mombin by a combination of chromatographic methods. Their structure was determined by NMR and MS techniques as (17:3), (17:2) and (17:1) pelandjuaic acid [or 6-(8'Z,11'Z,14'Z-heptadecatrienyl)-salicylic acid, 6-(8'Z,11'Z-heptadecadienyl)-salicylic acid, and 6-(10'Z-heptadecenyl)-salicylic acid, respectively], 6-(12'Z-non-adecenyl)-salicylic acid, and 6-(15'Z-heneicosenyl)-salicylic acid, the two last compounds being new ones. These phenolic acids were shown to have a pronounced antibacterial effect against Bacillus cereus, Streptococcus pyogenes, and Mycobacterium fortuitum (minimal bactericidal concentration in a concentration range of 3-25 micrograms/ml), and a molluscicidal effect against the snail Biomphalaria glabrata, an intermediate host in the schistosome life cycle. Because of their high molluscicidal activity (LC90 down to 1-3 ppm), these long-chain salicylic acid derivatives may be important tools in the prevention of schistosomiasis.

Isolation of a dihydrobenzofuran lignan from South American dragon's blood (Croton spp.) as an inhibitor of cell proliferation.

Dragon's blood is a red viscous latex extracted from the cortex of various Croton spp. (Euphorbiaceae), most commonly Croton lechleri, Croton draconoides (or Croton palanostigma), and Croton erythrochilus. It is used in South American popular medicine for several purposes, including wound healing. Bioassay-guided fractionation of dragon's blood, using an in vitro test system for the stimulation of human umbilical vein endothelial cells, has resulted in the isolation of a dihydrobenzofuran lignan, 3',4-O-dimethylcedrusin or 4-O-methyldihydrodehydrodiconiferyl alcohol [2-(3',4'-dimethoxyphenyl)-3-hydroxymethyl-2,3-dihydro-7-methoxybenzo furan-5- propan-1-ol] [1] as the biologically active principle. A related compound, 4-O-methylcedrusin [2-(3',4'-dimethoxyphenyl)-3-hydroxymethyl-2,3-dihydro-7-hydroxybenzo furan-5- propan-1-ol] [2], and the alkaloid taspine [3], also isolated from dragon's blood, were not active in the same assay. A cell proliferation assay, measuring the incorporation of tritiated thymidine in endothelial cells, showed that compound 1 did not stimulate cell proliferation, but rather inhibited thymidine incorporation, while protecting cells against degradation in a starvation medium.

Mass spectral characterization of C-glycosidic flavonoids isolated from a medicinal plant (Passiflora incarnata).

The four major C-glycosidic flavonoids isolated from Passiflora incarnata were identified as schaftoside, isoschaftoside, isovetexin-2''-O-glucopyranoside and isoorientin-2''-O-glucopyranoside on the basis of mass spectral and 13C NMR data. The daughter ion spectra of [M + H]+ ions of schaftoside and isoschaftoside showed differences for the [M + H - 104]+ ions, which could be rationalized by hydrogen bonding effects. In the negative-ion mode, pronounced differences were found for the [M - H - 90]- and [M - H - 120]- ions, formed by prevalent fragmentation in the C-6-linked sugar moiety. With respect to isovitexin-2''-O-beta-glucopyranoside and isoorientin-2''-O-beta-glucopyranoside, the daughter ion spectra of both the [M + H]+ and [M - H]- ions provided evidence for a 1----2 linkage in the diglucosidic moiety. Support for C-6 glucosylation was obtained by recording the daughter ion spectra of [M - H - 162]- ions, which were in good agreement with that obtained for [M - H]- ions of isovitexin.

The use of midazolam and flumazenil in locoregional anaesthesia: an overview.

Midazolam is useful as an intravenous supplement to local anaesthesia techniques in producing sedation, amnesia and anxiolysis, and has about five times the sedative potency of diazepam. Considerable interpatient variability exists in dose requirements, especially in elderly patients. The combined effects of local anaesthetics and midazolam may contribute to enhanced haemodynamic effects and changes in the respiratory pattern, impairing ventilation and oxygenation. Flumazenil can be titrated in incremental doses to reverse the residual sedative effects of midazolam, without intrinsic haemodynamic or respiratory effects, but may not fully antagonise the decrease in chemoreceptor sensitivity nor the changes in breathing pattern induced by midazolam. Patients treated with epidural or spinal anaesthesia supplemented with midazolam should be monitored to avoid hypoxaemia risks even after the administration of flumazenil.