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Biomedical subjects

C M Christensen

Publications and source records attributed to C M Christensen.

At least 55 records · Page 3Linked to original sources
PubMed1986

The influence of moderate reduction in dietary sodium on human salivary sodium concentration.

Twenty-four healthy subjects were placed for 12-13 weeks on diets that reduced average sodium intake from 145 to 74 m-equiv. Na+/day as determined by multiple 24-h urine collections before and during the diet. Whole-mouth resting and stimulated saliva was collected and analysed for flow rate and sodium concentration several times before and during the low-sodium period. Sodium restriction did not influence salivary flow rates but salivary sodium levels fell 25 per cent for resting and 17 per cent for stimulated saliva. Thus moderate reductions in sodium intake are accompanied by significantly lower salivary sodium levels.

Adult↗
PubMed1986

Preference of rats for food flavors and texture in nutritionally controlled semi-purified diets.

Preference for nutritionally controlled, semi-purified diets modified by the addition of potent food flavors was determined for Sprague Dawley rats using two-choice diet preference tests. Intake of each food cup was monitored after 1 hr and for each 24 hr period thereafter up to 5 days. Preference was also determined for the flavored diets prepared in three forms differing in texture: powdered, and pellets of two sizes. Rats easily detected minor amounts of the food flavors, and the tests provided a catalog of 12 preferred flavors. Exposure time to the diets altered preference for a minority of flavors; diets initially avoided in the first hour test were likely to become less aversive upon continued exposure. Whether or not a specific flavored diet was preferred, total food intake was not affected during the 5 day period monitored. Rats displayed strong preference for diets of a pelleted texture compared to the same diets in a powdered form.

Animals↗
PubMed1985

Effect of color on judgments of food aroma and flavour intensity in young and elderly adults.

The hypothesis was tested that subjects' judgments of food aroma and flavour strength will be increasingly influenced by food color as the chemosensory differences between foods become less apparent. Elderly (n = 24) and young (n = 22) adults were presented with pairs of food samples and instructed to indicate which sample had the more intense aroma or flavor. The chemosensory discriminations varied in difficulty, and the color of the food pairs was also manipulated so that either they were similarly colored, or the color strength differed so that it was either positively or inversely correlated with flavour strength. Overall, the results failed to support the hypothesis that color alters the perceived intensity of the food aroma or flavor. There was a weak trend toward a greater number of errors among sample pairs that varied in color, especially when color strength was inversely related to flavor strength. Elderly and young adult groups did not differ in chemosensory ability or in their responses to food color differences, although the elderly adults were significantly more certain of the accuracy of their chemosensory judgments.

Adult↗
PubMed1984

Effects of pharmacologic reductions in salivary flow on taste thresholds in man.

The effects of short-term salivary flow reductions on human taste thresholds were measured. Recognition and detection thresholds were obtained from 65 subjects during periods of both normal and reduced salivary flow. Decreased salivary flow was achieved by oral administration of either Elavil, Benadryl or atropine. Thresholds were measured for NaCl, citric acid, quinine sulphate and sucrose with a traditional series of aqueous solutions as well as with a series of dry taste stimuli using a filter-paper base. Whole mouth resting flow and stimulated salivary flow were measured before and after taste testing. The pharmacologic agents produced depressions in salivary flow ranging between 30 and 75 per cent of normal levels. The large decreases in flow produced no measurable changes in taste thresholds with the exception that an increased sensitivity to aqueous and dry citric acid stimuli consistently was observed following atropine administration. Changes in salivary bicarbonate levels, produced by atropine, may have mediated the observed shifts in oral sensitivity to citric acid.

Adolescent↗
PubMed1984

Anticipatory salivary flow to the sight of different foods.

Anticipatory salivary flow was measured to the sight of seven foods that varied in texture, composition and palatability. In one experiment, subjects consumed the test foods that were viewed. This group was tested both during conditions of hunger and satiation. In a second experiment, subjects were instructed that they would not consume the foods that were viewed. Salivary responses were not related to the anticipated palability of the test foods but rather appeared to be related to the physical and chemical properties of the foods. Pizza, chocolate cake and gelatin were rated as highly palatable, but significant salivary increases occurred only with pizza. Of all the test foods, the greatest salivary flow increases were observed to the sight of lemon slices and pizza, and both foods contain sour or pungent ingredients. Hunger state and the expectation of consuming the test foods did not systematically affect the pattern or magnitude of salivary responses.

Adolescent↗
PubMed1982

External parasites of dairy cattle.

Insects such as stable flies, house flies, horn flies, face flies, mosquitoes, horse flies, deer flies, cattle grubs, and lice as well as ticks and mites are the major external parasites of dairy animals in the United States. These pests cause obvious discomfort to livestock and economic effects of heavy populations usually are discerned easily. However, research efforts to date have failed to establish reproducible losses caused by specific ectoparasites. Research efforts involving a multidisciplinary systems approach are necessary to provide the data needed to develop total dairy management programs.

Animals↗
PubMed1979

Incidence of zearalenol (Fusarium mycotoxin) in animal feed.

Zearalenol, the reduction product of zearalenone produced by Fusarium roseum growing in cereals, was found for the first time naturally occurring in oats and corn. This metabolite is three to four times more active estrogenically than zearalenone.

Animal Feed↗
PubMed1977

The efficacy of chlordimeform for the control of the northern fowl mite, Ornithonyssus sylvarium (Canestrini and Fanzago) (Acarina, Dermanyssidae).

Chlordimeform applied as a 0.06% low pressure spray controlled the northern fowl mite (NFM) for at least 90 days. Tetrachlorvinphos applied as a 0.5% low pressure spray was equally effective. Chi square analysis of NFM population estimates indicated that NFM populations on the untreated control birds stayed essentially the same throughout the test, whereas, the NFM populations on both acaricide-treated groups were significantly lowered by the seventh day of the test (P less than .01). Chlordimeform seemed to work more slowly than tetrachlorvinphos in controlling NFM.

Amidines↗
PubMed1977

Effects on laying hens of feeding corn invaded by two species of Fusarium and pure T-2 mycotoxin.

Balanced rations containing 2.5 and 5.0% of corn invaded by Fusarium tricinctum, (with 8 and 16 p.p.m. of T-2 toxin) were fed to White Leghorm laying hens. The ration containing 5% of the fungus-invaded corn resulted in reduced feed intake and reduction in weight gain and in egg production. Rations containing 2.5 and 5.0% of corn invaded by F. roseum 'Gibbosum' (with 25 and 50 p.p.m., respectively, of monoacetoxyscirpenol) resulted in an abrupt decrease in feed intake to 10-20% of normal, subsequent loss in weight, and cessation of egg production. Purified T-2 toxin consumed at the rate of 16 p.p.m. in the ration resulted in loss of body weight and decreased egg production; lesser amounts of T-2 toxin resulted in lessened but still detectable injurious effects. Mouth lesions developed in the birds fed these rations, their severity being proportional to the amount of toxin present.

Animal Feed↗
PubMed1976

Natural occurrence of Fusarium toxins in feedstuff.

The mycotoxins diacetoxyscirpenol, deoxynivalenol, and zearalenone, produced by Fusarium roseum, were found naturally occuring in mixed feed samples. In all cases analyzed, deoxynivalenol occurred together with zearalenone. The natural occurrence of zearalenone in sesame seed is reported for the first time. Strains of F. roseum isolated in various parts of the world form feed implicated in animal mycotoxicosis produced monoacetoxyscirpenol, diacetoxyscirpenol, deoxynivalenol, and zearalenone.

Animal Feed↗