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At least 73 records · Page 4Linked to original sources
PubMed1989

Integration of ovulation rate, potential embryonic viability and uterine capacity into a model of litter size in swine.

A mathematical model of litter size in swine was developed from ovulation rate, potential embryonic viability and uterine capacity. The model assumed that ovulation rate was reduced to potentially viable embryos by factors innate to the ovum and embryo. Potentially viable embryos then could be further reduced to uterine capacity, the maximum number of fetuses that a female can carry to term. Consequently, litter size can be no greater than either ovulation rate or uterine capacity. Means and variances of ovulation rate and potential embryonic viability used in the model were based on experimental results. The mean and variance of uterine capacity were varied until the simulated mean and variance of litter size were equal to experimental results. Simulated results of relationships among ovulation rate, embryo survival and litter size were similar to observed experimental relationships. Heritabilities of simulated litter size and embryo survival were similar to literature values when the heritability of ovulation rate was set at .25 and the heritability of uterine capacity was set at either .15 or .20. Litter size was simulated for 25 combinations of average ovulation rate and uterine capacity to develop equations relating mean ovulation rate and uterine capacity to litter size, embryo survival and correlations among them. Results suggest that changing either ovulation rate or uterine capacity independently will not result in large changes in litter size. Consequently, the model suggests that a single gene, hormonal manipulation or nutritional change will not result in large increases in litter size and that combinations of factors will be needed to increase litter size.

Algorithms↗
PubMed1992

Nutritional and pathophysiologic effects of clinically apparent and subclinical infections of Ostertagia ostertagi in calves.

Nutritional and physiologic effects of clinically apparent and subclinical Ostertagia ostertagi infections were studied in 3 groups of 5 calves each. Group-1 calves were inoculated with 100,000 Ostertagia ostertagi third-stage larvae (L3)/calf/wk for 14 weeks. Group-2 calves were inoculated with 10,000 L3/calf/wk for 14 weeks, and group-3 calves were no inoculated. Calves in group 1 had decreased dry matter intake and feed utilization from 4 weeks after initial inoculation. Group-2 calves had no changes in dry matter intake, but had decreased feed utilization at 12 and 14 weeks. Calves with clinically apparent infections (group 1) lost a mean weight of 11.8 kg, whereas calves with suclinical infections (group 2) lost a mean of 46.6 kg, and control calves lost a mean of 60.7 kg. Calves with O ostertagi infections (group 1 and 2) also had decreased carcass quality at slaughtering, which was reflected in decreased dressing weights and increased water-holding capacity of the rib-eye muscle. Calves in groups 1 and 2 also had lower carcass yield and rib-eye muscle weight, and group-1 calves had decreased protein content. Results of hematologic, pathologic, parasitologic, and clinical examinations mirrored nutritional changes.

Animal Nutritional Physiological Phenomena↗
PubMed1991

Maternal nutritional status and milk volume. Is there a cause-effect relationship?

Studies on human lactation were examined in order to gather some answers about questions concerning the effect of maternal food intake, size, fatness and economic status on milk production. Up to date, evidence in the literature is insufficient to permit definitive answers, but a general conclusion can be drawn: milk volume varies little among mothers with largely variable energy intakes, sizes and economic status. There is a great need for more controlled studies focusing on the relationship between maternal energy balance and milk output. Although many studies have separately addressed the nutritional changes in mothers throughout lactation (1-8) and milk consumption by infants (9-17), very few have correlated maternal nutritional conditions and the volume of milk consumed. This report will consider investigations published from 1975 and on, combining data on maternal nutritional status and milk production in the same individual. The rationale is that around 1975 more accurate and standardized methodology began to be used in related studies. Milk output is estimated by the summary of the differences of body weights of infants obtained before and after each milking episode during 24 hours. Before 1975 the balances used for such a purpose had very poor precision, and this interfered seriously on the inter and intra-personal variability of the measurements. Electronic scales made available after that year gave enough reliability to the procedure. This report is comprised of studies from birth to four months postpartum, when energy supplementation is less common, and quantitatively less important. Nutritional status of the mothers will be analyzed on the basis of four categorizing variables: social and economic status, anthropometry, food intake and body composition.

Anthropometry↗
PubMed1976

Changes in the adrenergic control and the rate of lipolysis of isolated human adipose tissue during fasting and after re-feeding.

The influence of changes in nutritional state on lipid mobilization has been investigated, using subcutaneous fat portions removed from 8 obese patients submitted to fasting for one week. The maximal rise in the tissue level of cyclic AMP (cAMP) and the rate of glycerol release were determined when adipose tissue was exposed to noradrenaline (6 X 10(-6) mol/1), isopropylnoradrenaline (6 X 10 (-6) mol/1) or none of the agents (basal medium). Fasting resulted in significant increases in the tissue level of cAMP and the rate of lipolysis in adipose tissue unexposed to lipolytic agents. Noradrenaline decreased the level of cAMP, in contrast to isopropylnoradrenaline, and significantly inhibited the rate of lipolysis during fasting. These noradrenaline effects were abolished by the simultaneous presence of phentolamine (13 mmol/1) in the incubation medium. Re-feeding with Meritene for one day resulted in a diminished rate of basal lipolysis, whereas the cAMP level was unaffected. The response of the cAMP accumulation to isopropylnoradrenaline was further augmented by re-feeding. Noradrenaline produced a significant rise in the level of cAMP and significantly stimulated the rate of glycerol production. It is concluded that the nutritional changes are of significance for the adrenergic regulation of lipolysis as indicated by the response of cAMP to the catecholamines. In pharmacological terms, fasting for one week resulted in increased alpha-as well as beta-adrenergic responsiveness. Increased basal lipolysis during fasting may be related to an increased level of cAMP or a direct activation of lipase.

Adipose Tissue↗
PubMed1991

[Hypercholesterolemia and hypertension--equivalent risk factors?].

Official recommendations for handling of hypercholesterolaemia are based on the comprehensive knowledge of serum cholesterol values in the healthy population as knowledge of blood pressure is desirable. To question this premise, both observational and interventional trials concerning the two risk factors are compared. Apparent similarities are produced by the fact that in hypertension trials control persons often are treated in the condition of normal care, whereas in lipid trials they are not. Early hypertension studies confirm beyond any doubt that the profit of hypotensive drugs is much higher than that of any cholesterol-lowering measure. The difference is most striking in the high-risk groups, comparing the treatment benefit in malignant hypertension with the hitherto poor results in familial hypercholesterolaemia. The author suggests a thorough analysis of all screening tests and interventional recommendations in medicine, aiming to allocate only a limited proportion of the normal population to regular medical supervision. There hypercholesterolaemia will have its modest place. Instead of intensified screening and drug treatment of healthy individuals, general advice for nutritional changes seems more reasonable.

Adult↗
PubMedDate not supplied

[Artificial nutrition in bone marrow transplantation].

The issue of nutritional support in oncologic patients is reviewed. Special reference is made in relation to patients undergoing bone marrow transplant and their possible digestive tract and nutritional changes induced by the different therapies available in these situations. Nutritional evaluation and caloric and nitrogen requirement calculations have been proposed. Likewise, several possibilities have been considered regarding the route of administration, timing and quality of the nutriments to be administered, both to adult and pediatric patients.

Adult↗
PubMed1990

Biological variation in serum lipid concentrations.

Individual variations in serum lipid concentrations resulting from laboratory error are often much less than those due to other factors. Thus the coefficient of variation for biological fluctuations in cholesterol is 5-10% and for triglyceride concentration 5-25%. Many of the causes of changing lipid levels are known. Sampling conditions (venous stasis, body position) contribute as does the handling of the blood sample before it reaches the laboratory, for example whether an anticoagulant is used and haemolysis, clearly meals have a major effect on serum triglycerides, but even when fasting there is probably also diurnal variation. Fluctuations in serum lipids occur during the menstrual cycle, cholesterol and triglycerides tending to be highest at midcycle and to decline towards menstruation. Pregnancy produces major increases in both cholesterol and triglyceride levels. There is a well established seasonal variation in cholesterol concentrations which are greatest in autumn and lowest in late spring and early summer. This may be partly due to nutritional changes, but similar findings in laboratory animals suggest that humoral factors may also be important. Age also influences serum lipids. It is frequently not appreciated that both cholesterol and triglycerides are at their lowest in adolescence. Rapid increases in cholesterol may occur in women around the menopause. Lipid concentrations may undergo considerable change during illness. The decrease in LDL and HDL cholesterol and apo B and tendency for increases in triglycerides during acute myocardial infarction are well known but similar alterations can also occur with angina or coronary artery bypass surgery. Other surgical operations and intercurrent illnesses, perhaps even common viral infections, may also influence lipids.(ABSTRACT TRUNCATED AT 250 WORDS)

Aging↗
PubMed1990

[Tryptophan metabolism during the perinatal period].

UNLABELLED: Tryptophan is considered to be an important indicator of nutritional changes during the perinatal period, from fetus to neonate. By means of high performance liquid chromatography (HPLC), we determined the concentrations of both free tryptophan (TRP) and its metabolite, kynurenine (KYN), in maternal venous plasma (M.V.) and umbilical arterial and venous plasma (U.A., U.V.) (n = 45) at the time of delivery. TRP and KYN concentrations were also measured in neonatal venous plasma (n = 11) for 3-5 days following delivery. RESULTS: 1) Day and night plasma TRP levels in non-pregnant women (n = 12), in pregnant women at term before labor (n = 12) and in delivering women (M.V.) (n = 45: day, n = 24: night, n = 21) were significantly different. 2) Both TRP and KYN concentrations were significantly higher in U.A. and U.V. than those in M.V., the concentration gradient being approximately 1:2, and a positive maternal-fetal relationship was observed (r = 0.586-0.944, p less than 0.01). 3) A positive relationship was observed between the venous-arterial gradient of umbilical cord tryptophan and the Kaup Index (r = 0.316, p less than 0.05). 4) In order to minimize individual variations, the ratios of TRP and KYN levels in newborn venous plasma to those in the umbilical arteries were calculated (n = 11). These ratios started to increase at 20-50 hours after delivery, which suggested that the first milk feeding may alter the metabolism of tryptophan in neonates.

Adult↗
PubMed1989

The value of ischaemic heart disease vital statistics since 1968.

Although individual cases of IHD (Ischaemic Heart Disease) are frequently misclassified, the overall reliability of IHD vital statistics in industrialized countries is better than claimed. Random classification errors produce a correct mean value, whereas systematic misclassifications produce an opposite change in one or more different causes of death, since total number of deaths is correct in the age group and countries under consideration. Therefore it is important to compare a certified cause of death to several others, including total mortality. The comparison of death rates should be done in many countries, over several years, for each sex and between sexes. Since the 8th revision (1968) the comparability between years has improved. The mean mortality rates over the available years, the slopes calculated over the years and the % change of IHD in men and in women were correlated with different causes of death in men and in women, totalling 111 comparisons. Some of these (cancer of the rectum, colon, prostate and breast, diabetes and stroke) are related with nutrition. In total 71 out of the 111 correlations were significant, 28 of which with p less than 0.001. Criteria have been defined for checking the reliability of the slopes of IHD mortality with time since 1968. The trends in IHD mortality were compared with observed changes in nutrition. These nutritional changes, especially those of saturated fat, are generally consistent with the observed rates or time trends of the diseases under consideration. In conclusion, although classification errors occur they are not of a level of magnitude that makes valid conclusions impossible.

Australia↗
PubMed1989

Measuring change in nutritional status: a comparison of different anthropometric indices and the sample sizes required.

The usefulness of different anthropometric indices to detect nutritional changes at the community level, ie, in a number of children considered as a group, was compared by using data from a longitudinal study from rural Bangladesh which followed up quarterly an average of 413 children aged 6-35 months from December 1984 to December 1987. Weight change, mid-upper arm circumference and weight-for-height responded most quickly to seasonal variations of the food situation. Height-for-age was more responsive to long-term variations. Although similar conclusions were reached when proportions of children below a cut-off point or mean indices were compared, the comparison of mean indices required a smaller sample size to detect changes. The difference in sample size needed ranged from 48 to 61 per cent. All indices varied significantly with age, which suggests that precise knowledge of age is essential for proper interpretation of nutritional surveillance data.

Aging↗
PubMedDate not supplied

[Correlation between pregnancy and dental caries].

The purpose of this review is to examine the correlation between pregnancy and dental caries. The epidemiologic results are few and controversial, leading to no certain conclusion. The possible causes of caries during pregnancy are: changes in saliva and mouth flora, vomiting, neglected oral hygiene and nutritional changes. The causes are extensively discussed, particularly the last two, which seem to be the basic ones, although the others cannot be rejected. The increased needs of dental care of the woman during pregnancy must be emphasized, as well as her special management during the dental treatment. Treating the pregnant patient is a task of a group of specialists which should include the dentist, too. A protocol for facing the pregnant's dental treatment needs is suggested.

Dental Caries↗
PubMed1985

[Biochemical and nutritional studies of germinated soybean seeds].

The purpose of this work was to determine the biochemical and nutritional changes of soybean seeds during germination. Soybean seeds were soaked for a period of eight hours and then germinated for 0, 1, 3 and 5 days. Part of them was subjected to an autoclave process. Then, both the raw and cooked seeds were dried, ground and analyzed. During the germination process an increase in the percentage content of protein and fiber in the seeds occurred; cooked seeds, in contrast, showed a slight decrease with respect to the former. Ether extract increased in percentage until the third day, and then decreased on the fifth. In the cooked seeds, higher values than in the raw seeds were obtained, due to the fact that when seeds were autoclaved, protein and carbohydrate losses occur. In regard to ash content, this diminished in percentage as germination advanced; the same happened to the free-protein extract. The raffinose and stachyose sugars, factors which cause flatulence, disappeared on the third germination day. As to nitrogen extraction, a greater percentage was obtained using distilled water as solvent, both for the raw and cooked seeds, than when using NaOH and NaCl. The trypsin inhibitors content increased on the first day of germination and then decreased. Ungerminated, autoclaved seeds, showed no trypsin inhibitors activity, whereas in the germinated cooked seeds, it increased slightly as germination days went by. Regarding protein efficiency ratio (PER), seeds with 0, 1 and 3 germination days presented no significant differences among them, the cooked seeds exhibiting higher values than the raw seeds. Apparent digestibility increased as the germination period advanced, having obtained better values when they were autoclaved. In the soybean milk acceptability test, no significant differences were observed between milk from ungerminated soybean seeds, and milk from the 3-day germinated seeds.

Animals↗
PubMed1978

Complications of jejunoileal bypass.

Jejunoileal bypass for morbid obesity is accompanied by excessive morbidity and significant mortality. Weight loss is achieved at the expense of major nutritional changes which in and of themselves produce complications. The operation should be considered investigational and be limited to those centers with special interest in the problem and where longterm follow-up and management can be carried out.

Adult↗
PubMed1992

Consistent improvement in the nutritional status of Colombian children between 1965 and 1989.

Three national anthropometric surveys carried out in Colombia in 1965-1966, 1977-1980, and 1986-1989 provide a reasonably standardized basis for comparing the nutritional status of infants and young children in those years. That comparison, presented here together with appropriate socioeconomic data, indicates marked reduction of malnutrition paralleling strong socioeconomic gains.

Adult↗
PubMed1988

The use of anthropometry to assess nutritional status.

Anthropometry (the use of body measurements to assess nutritional status) is a practical and immediately applicable technique for assessing children's development patterns during the first years of life. An evaluation of their growth also provides useful insights into the nutrition and health situation of entire population groups. Anthropometric indicators are less accurate than clinical and biochemical techniques when it comes to assessing individual nutritional status. In many field situations where resources are severely limited, however, anthropometry can be used as a screening device to identify individuals at risk of undernutrition, followed by a more elaborate investigation using other techniques. Similarly, growth monitoring permits the detection of individuals with faltering growth, who can then be appropriately referred to specialized care. Thanks to the standardization that has taken place in recent years, changes in trends over time with respect to the nutritional situation can be evaluated in countries where national food and nutrition surveillance systems have been developed, or where nationally representative cross-sectional surveys have been conducted some years apart using identical, or nearly identical, methodologies. Although data that can be used to evaluate trends are limited, some insight can be gained into the nutritional situation and changes occurring over time in a number of countries. Prevalence figures for underweight (low weight-for-age) have been prepared using standard methods of data collection, analysis and presentation, for several countries in Africa, the Americas and Asia. As such, they fail to differentiate between wasting and stunting, or to evaluate differences between age groups. Also, they do not necessarily reflect trends in other countries in the same or other regions. Still, it is interesting, if not statistically significant, that there has been a general improvement in the nutritional status of preschool children. Intercountry trend comparisons are difficult for two main reasons. Firstly, the time between surveys is occasionally different and, secondly, despite efforts to standardize data analysis and presentation, different cut-off points have been used to calculate prevalence figures and estimate the extent of undernutrition. However, the use of identical cut-off points is not essential for making intercountry trend analyses since it is the general trends in growth deficit and nutritional status over time which are being evaluated.(ABSTRACT TRUNCATED AT 400 WORDS)

Adolescent↗
PubMed1977

Reducing the risk of cardiovascular disease: effects of a community-based campaign on knowledge and behavior.

In 1972 the Stanford Heart Disease Prevention Program launched a three-community field study. A multimedia campaign was conducted for two years in two California communities (Watsonville and Gilroy), in one of which (Watsonville) it was supplemented by an intensive-instruction program with high-risk subjects. A third community (Tracy) was used as a control. The campaigns were designed to increase participants' knowledge of the risk factors for cardiovascular disease, to change such risk-producing behavior as cigarette smoking, and to decrease the participants' dietary intake of calories, salt, sugar, saturated fat, and cholesterol. Results of a sample survey indicate that substantial gains in knowledge, in behavioral modification, and in the estimated risk of cardiovascular disease can be produced by both methods of intervention. The intensive-instruction program, when combined with the mass-medica campaign, emerged as the most effective for those participants who were initially evaluated to be at high risk. The results after two years of intervention are reported for effects on knowledge and behavioral change for the total participant samples and for the high-risk subsamples in each of the three communities.

Attitude to Health↗
PubMed1987

Infant mortality and childhood nutritional status among Afghan refugees in Pakistan.

In 1984 and again in 1985, systematic surveys were undertaken to evaluate infant mortality and childhood nutritional status among the Afghan refugee population in Pakistan. The entire Afghan refugee population under the administration of the United Nations High Commissioner for Refugees was sampled. Infant mortality rates were estimated to be 156 per 1000 for 1984 and 119 per 1000 for 1985. A decline was also suggested in neonatal mortality rates from 61 per 1000 for 1984 to 46 per 1000 for 1985. For neither infant nor neonatal mortality was the difference statistically significant. Improvements were seen in the percentage of children who died before their fifth birthday (22.5% in 1984 and 18.8% in 1985), in the percentage of children who were malnourished (3.5% in 1984 and 2.3% in 1985), and an increase in the percentage of children above the WHO/NCHS/CDC weight-for-height reference median (26% in 1984 and 35% in 1985). Diarrhoea was the most frequently reported cause of death for both years and was a particularly important cause of death among one-year-old children. In 1985, measles was related to 24% of the deaths and neonatal tetanus to 9% of the deaths, an increase from 8% for measles and 6% for tetanus in 1984.

Afghanistan↗