Use of Dorset egg medium for maintenance and transport of Neisseria meningitidis and Haemophilus influenzae type b.
Studies of bacterial meningitis are hampered by the inability to maintain the viability of etiological agents during transport to reference laboratories. The long-term survival rate of 20 isolates of Neisseria meningitidis and Haemophilus influenzae type b (Hib) on Dorset egg medium, supplemented Columbia agar base medium, chocolate agar, and Amies medium was compared with that on 70% GC agar (chocolate) transport medium. N. meningitidis isolates were also inoculated onto 5% horse blood agar, and Hib was inoculated onto Haemophilus test medium. All of the N. meningitidis isolates remained viable on Dorset egg medium for 21 days; viability on the other media was poor after only 7 days. Recovery rates of Hib isolates were similar on Dorset egg and Haemophilus test media (100% after 21 days) and significantly better than on the other media. Dorset egg medium is inexpensive and easy to make and may be invaluable for studies of bacterial meningitis in developing countries. (+info)
Teas and other beverages suppress D-galactosamine-induced liver injury in rats.
We compared the effects of various types of beverages (teas, coffee, and cocoa) on D-galactosamine-induced liver injury by measuring plasma alanine aminotransferase (ALT) and aspartate aminotransferase (AST) activities in 7-wk-old male Wistar rats. The effects of five fractions extracted with different organic solvents from green tea, different types of dietary fibers, and some short chain fatty acids were also investigated. All of the beverages tested significantly suppressed D-galactosamine-induced enhancement of plasma enzyme activities when powdered beverages were added to the diet (30 g/kg) and fed to rats for 2 wk. Plasma ALT activities were 1155 +/- 82 [micromol/(min.L), control], 289 +/- 61 (green tea), 626 +/- 60 (roasted green tea), 471 +/- 84 (puerh tea), 676 +/- 69 (oolon tea), 423 +/- 76 (black tea), 829 +/- 53 (coffee), and 885 +/- 89 (cocoa). The profile of AST activities was similar. The caffeine-containing fraction from green tea had no significant effect, whereas the other four fractions, including the soluble fiber fraction, significantly suppressed liver injury. In addition to tea fibers, many other types of dietary fiber (hemicellulose, chitin, chitosan, alginate, pectin, guar gum, glucomannan, and inulin, but not cellulose) had liver injury-preventive effects when added to the diet (30 g/kg), suggesting that liver injury-prevention may be one of the general effects of dietary fibers. Of three short-chain fatty acids tested (acetate, propionate, and butyrate), only acetate prevented liver injury when added to the diet (15 g/kg), supporting the possibility that the liver injury-preventive effect of dietary fibers may be mediated at least in part by certain organic acids. These results suggest that several beverages possess preventive effects on certain types of liver injury, such as that induced by D-galactosamine, and that different constituents of high and low molecular weights contribute to the liver injury-preventive effects of green tea. (+info)
Protection against peroxynitrite by cocoa polyphenol oligomers.
Flavonoids, natural plant constituents, protect against peroxynitrite and can thereby play a role in defense against this mediator of inflammation. Procyanidin oligomers of different size (monomer through nonamer), isolated from the seeds of Theobroma cacao, were examined for their ability to protect against peroxynitrite-dependent oxidation of dihydrorhodamine 123 and nitration of tyrosine. By molarity, oligomers were more effective than the monomeric epicatechin; the tetramer was particularly efficient at protecting against oxidation and nitration reactions. These results suggest that epicatechin oligomers found in cocoa powder and chocolate may be a potent dietary source for defense against peroxynitrite. (+info)
A comparison of blood agar supplemented with NAD with plain blood agar and chocolated blood agar in the isolation of Streptococcus pneumoniae and Haemophilus influenzae from sputum. Bacterial Methods Evaluation Group.
Streptococcus pneumoniae grows well and generally exhibits typical morphology on Columbia blood agar, whereas Haemophilus influenzae requires a more complex medium to meet its growth requirements - usually chocolated blood agar - on which S. pneumoniae is less easily recognisable. Therefore, a single medium that produces typical morphology of S. pneumoniae and facilitates the growth of H. influenzae would have considerable potential advantages. It has been claimed that blood agar supplemented with nicotinamide adenine dinucleotide (NAD) is such a medium. However, despite its routine use in several large diagnostic laboratories its performance has never been properly evaluated. In the present study, 1724 sputum samples were examined in four laboratories. The isolation rates of H. influenzae and S. pneumoniae on NAD-supplemented blood agar (SBA) were compared with those on a two-plate combination of plain blood (BA) and chocolated blood agar (CBA). The two-plate combination performed significantly better for both organisms; isolation rates for H. influenzae were increased from 8.16% on SBA to 11.07% on BA plus CBA and for S. pneumoniae from 4.18% to 4.68%. Isolation rates were also compared after incubation for 24 and 48 h. With the two-plate combination, isolation rates for H. influenzae and S. pneumoniae were increased by 0.98% and 0.16%, respectively, and for SBA by 0.57% and 0.32% after 48 h. However, despite this increase, SBA still performed less well than the two-plate combination. (+info)
An olfactory discrimination procedure for mice.
This paper describes an olfactory discrimination procedure for mice that is inexpensively implemented and leads to rapid discrimination learning. Mice were first trained to dig in small containers of sand to retrieve bits of buried chocolate. For discrimination training, two containers were presented simultaneously for eight trials per session. One container held sand mixed with cinnamon, and the other held sand mixed with nutmeg. Both containers were baited with chocolate buried in the sand. One odor was designated S+, and mice were allowed to dig and retrieve the chocolate from this container. The other odor was S-, and both containers were removed immediately if subjects began to dig in an S- container. After meeting a two-session acquisition criterion, subjects were given a series of discrimination reversals. In Experiment 1, 12 Swiss-Webster mice (6 male and 6 female) acquired the olfactory discrimination in three to five sessions and completed 3 to 10 successive discrimination reversals within a 50-session testing limit. In Experiment 2, subjects were 14 Pah(enu2) mice, the mouse mutant for phenylketonuria; 7 were homozygotes in which the disorder was expressed (PKU), and 7 were heterozygotes with normal metabolism (non-PKU). Thirteen mice completed pretraining in four to seven sessions, acquisition required 3 to 12 sessions, and all mice completed at least three reversals. Learning rates were similar in PKU and non-PKU mice. We discuss issues related to implementation and several potentially useful procedural variations. (+info)
Cocoa inhibits platelet activation and function.
BACKGROUND: Epidemiologic studies have shown inverse associations between dietary polyphenols and mortality from coronary heart disease. However, the basis for this protective association is uncertain. Food polyphenols reportedly have antioxidant properties and decrease platelet function in vitro. OBJECTIVE: This study sought to evaluate whether consumption of a polyphenol-rich cocoa beverage modulates human platelet activation and primary hemostasis. DESIGN: Peripheral blood was obtained from 30 healthy subjects before and 2 and 6 h after ingestion of a cocoa beverage (n = 10), a caffeine-containing control beverage (n = 10), or water (n = 10). Platelet activation was measured in terms of expression of activation-dependent platelet antigens and platelet microparticle formation by using fluorescent-labeled monoclonal antibodies and flow cytometry. Primary platelet-related hemostasis was measured with a platelet function analyzer. RESULTS: Ex vivo epinephrine- or ADP-stimulated expression of the fibrinogen-binding conformation of glycoprotein IIb-IIIa was lower 2 and 6 h after consumption of cocoa than before consumption. Cocoa consumption also decreased ADP-stimulated P-selectin expression. In contrast, epinephrine-induced platelet glycoprotein IIb-IIIa expression increased after consumption of the caffeine-containing beverage but not after water consumption. Platelet microparticle formation decreased 2 and 6 h after cocoa consumption but increased after caffeine and water consumption. Primary hemostasis in response to epinephrine in vitro was inhibited 6 h after cocoa consumption. The caffeine-containing beverage inhibited ADP-induced primary hemostasis 2 and 6 h after consumption. CONCLUSIONS: Cocoa consumption suppressed ADP- or epinephrine-stimulated platelet activation and platelet microparticle formation. Cocoa consumption had an aspirin-like effect on primary hemostasis. (+info)
Food of the gods: cure for humanity? A cultural history of the medicinal and ritual use of chocolate.
The medicinal use of cacao, or chocolate, both as a primary remedy and as a vehicle to deliver other medicines, originated in the New World and diffused to Europe in the mid 1500s. These practices originated among the Olmec, Maya and Mexica (Aztec). The word cacao is derived from Olmec and the subsequent Mayan languages (kakaw); the chocolate-related term cacahuatl is Nahuatl (Aztec language), derived from Olmec/Mayan etymology. Early colonial era documents included instructions for the medicinal use of cacao. The Badianus Codex (1552) noted the use of cacao flowers to treat fatigue, whereas the Florentine Codex (1590) offered a prescription of cacao beans, maize and the herb tlacoxochitl (Calliandra anomala) to alleviate fever and panting of breath and to treat the faint of heart. Subsequent 16th to early 20th century manuscripts produced in Europe and New Spain revealed >100 medicinal uses for cacao/chocolate. Three consistent roles can be identified: 1) to treat emaciated patients to gain weight; 2) to stimulate nervous systems of apathetic, exhausted or feeble patients; and 3) to improve digestion and elimination where cacao/chocolate countered the effects of stagnant or weak stomachs, stimulated kidneys and improved bowel function. Additional medical complaints treated with chocolate/cacao have included anemia, poor appetite, mental fatigue, poor breast milk production, consumption/tuberculosis, fever, gout, kidney stones, reduced longevity and poor sexual appetite/low virility. Chocolate paste was a medium used to administer drugs and to counter the taste of bitter pharmacological additives. In addition to cacao beans, preparations of cacao bark, oil (cacao butter), leaves and flowers have been used to treat burns, bowel dysfunction, cuts and skin irritations. (+info)
Procyanidin content and variation in some commonly consumed foods.
Procyanidins are a subclass of flavonoids found in commonly consumed foods that have attracted increasing attention due to their potential health benefits. However, little is known regarding their dietary intake levels because detailed quantitative information on the procyanidin profiles present in many food products is lacking. Therefore, the procyanidin content of red wine, chocolate, cranberry juice and four varieties of apples has been determined. On average, chocolate and apples contained the largest procyanidin content per serving (164.7 and 147.1 mg, respectively) compared with red wine and cranberry juice (22.0 and 31.9 mg, respectively). However, the procyanidin content varied greatly between apple samples (12.3-252.4 mg/serving) with the highest amounts on average observed for the Red Delicious (207.7 mg/serving) and Granny Smith (183.3 mg/serving) varieties and the lowest amounts in the Golden Delicious (92.5 mg/serving) and McIntosh (105.0 mg/serving) varieties. The compositional data reported herein are important for the initial understanding of which foods contribute most to the dietary intake of procyanidins and may be used to compile a database necessary to infer epidemiological relationships to health and disease. (+info)