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PubMed1996

Internal doses to Ukrainian populations using Dnieper River water.

The dynamics of internal doses from 137CS and 90Sr as a consequence of the use of Dnieper River water were calculated. Local peculiarities of municipal tap, irrigation, and fish consumption in the Ukraine were considered. The dynamics of 90Sr accumulation in human bone as a result of the use of Dnieper water is simulated. The dose predictions are based on de facto data and the stochastic forecast of radionuclide concentrations in Dnieper reservoirs. A large array of statistical data on the age-structures of exposed populations, food consumption rate, agricultural production, fish contamination, and site-specific parameters were used. Exposures are estimated for 12 regions of the Dnieper basin and the Crimea Republic. The maximal individual annual committed effective doses are 1.7 X 10(-5) and 2.7 X 10(-5) Sv from 90Sr and 137Cs, respectively, due to the use of water in 1986 by members of the population in the Kievska region. Commercial fishermen on the Kievska reservoir, who consumed 360 kg y(-1) of fish in 1986, received 4.7 X 10(-4) and 5 X 10(-3) Sv from 90Sr and 137Cs, respectively. The contributions to the collective (over 70 y) effective dose of irrigation, municipal tap water, and fish consumption for members of the general public, respectively, are 18%, 43%, 39% in the Kievska region; 8%, 25%, 67% in the Poltavska region; 50% 50%, 0% (no Dnieper fish consumed) in the Crimea Republic. The predicted contribution of 90Sr to collective dose resulting from the use of water is 80%. The collective dose to the population of the Dnieper regions (32.5 million people) is 3,000 person-Sv, due to the use of water.

Cesium Radioisotopes↗
PubMed1998

How much and what classes of carbohydrate reach the colon.

On current estimates it is likely that about 30 g carbohydrate per day enters the colon. It is probable that our estimates of starch and its degradation products entering the colon, true resistant starch, in a physiological sense, are too low. With total starch intakes of the order of 150 g one might expect a contribution of the order of, for example, 15 g assuming a digestion/absorption efficiency of 90%. However, the digestion of starch and the hydrolysis of the disaccharides and malto-oligosaccharides in the brush border of the small intestine are extremely efficient, so that the overall efficiency of digestion/absorption will be very dependent on the physical structure and properties of foods. More detailed analyses of the oligosaccharides in foods, especially cereals, may lead to revised estimates. Estimates of the amounts of carbohydrates required to support the bacterial mass produced should also be examined more closely. It is also questionable whether estimates of breath hydrogen production on a typical diet are indicative of the current estimates of carbohydrate substrate required for the production of bacterial mass.

Animals↗
PubMed2006

Marine and freshwater cyanophages in a Laurentian Great Lake: evidence from infectivity assays and molecular analyses of g20 genes.

While it is well established that viruses play an important role in the structure of marine microbial food webs, few studies have directly addressed their role in large lake systems. As part of an ongoing study of the microbial ecology of Lake Erie, we have examined the distribution and diversity of viruses in this system. One surprising result has been the pervasive distribution of cyanophages that infect the marine cyanobacterial isolate Synechococcus sp. strain WH7803. Viruses that lytically infect this cyanobacterium were identified throughout the western basin of Lake Erie, as well as in locations within the central and eastern basins. Analyses of the gene encoding the g20 viral capsid assembly protein (a conservative phylogenetic marker for the cyanophage) indicate that these viruses, as well as amplicons from natural populations and the ballast of commercial ships, are related to marine cyanophages but in some cases form a unique clade, leaving questions concerning the native hosts of these viruses. The results suggest that cyanophages may be as important in freshwater systems as they are known to be in marine systems.

Bacteriophages↗
PubMed1979

Patterns of cell division, DNA base compositions, and fine structures of some radiation-resistant vegetative bacteria found in food.

Representative highly radiation-resistant Moraxella-Acinetobacter (M-A), Pseudomonas radiora, Micrococcus radiodurans, and Micrococcus radiophilus exhibited a wide variety of division systems and cell wall characteristics. However, the most resistant M-A possessed unusually thick cell walls, indicating a possible role of the cell wall in radiation resistance in the M-A. Thick septation was present in most of the bacteria studied, but was absent in P. radiora, thus excluding this as a necessity for high resistance. Reliable determination of the number of division planes of the M-A for use as a taxonomic criterion was achieved by the direct observation of dividing cells. The highly resistant M-A were found to divide in multiple planes and had base compositions of 54.0 to 57.5%, unlike typical Moraxella and/or Acinetobacter species. The taxonomic position of most highly resistant bacteria remains unclear.

Bacteria↗
PubMed1992

Dietary intake and nutritional status in patients with systemic sclerosis.

Oesophageal dysmotility and abnormalities of intestinal function are important manifestations in systemic sclerosis and may have a significant effect on nutrient absorption and nutritional status. In this study 30 patients with systemic sclerosis with symptoms from the gastrointestinal tract were compared with matched healthy control subjects with respect to nutrient intake (four day record), anthropometric measurements, and biochemical nutritional status. The intake of energy (8.1 and 8.4 MJ/day) and its distribution among nutrients did not differ between patients and control subjects, but the lower intake of dietary fibre among patients with systemic sclerosis suggests that they avoided food with a coarse structure, such as coarse bread. The intake of vegetables and fruit also tended to be lower among patients with systemic sclerosis. Half of the patients had a subnormal arm muscle circumference, and two patients also had a subnormal triceps skinfold thickness, indicating severe malnutrition. The concentration of ascorbic acid, alpha-tocopherol, carotene, selenium, and also the proportion of linoleic acid (18:2) in serum phosphatidylcholine was lower in patients than in control subjects.

Adult↗
PubMed1980

Food capture and ingestion in the large heliozoan, Echinosphaerium nucleofilum.

Using its microtubule-containing axopodia, a heliozoan Echinosphaerium nucleofilum feeds on various kinds of protozoans and small metazoans. The present study revealed that food capture and ingestion were carried out in 2 different ways or by a combination of them. The first one was by the rapid contraction of axopodia, by which the food organism was conveyed directly toward the body surface. After such a contraction, many of the microtubules which had been present inside the axopodia degraded and were replaced by C-shaped microtubules. Bundles of tubular bodies were also detected alongside the axonemal microtubules, especially following the use of glutaraldehyde fixative containing ruthenium red. The second method was by means of axopodial flow, by which a food organism attached to an axopodium was conveyed to the body surface along the axopodial surface without accompanying axopodial degradation or contraction. Subsequently the food organism was surrounded by several small pseudopodia to form a food vacuole; many filamentous structures (5-10 nm in diameter) were observed inside the pseudopodia. During the ingestion process many cytoplasmic extensions, including rosary-like filaments, were observed to protrude from the contracted axopodia and the cell body. Mottled dense granules were observed to be discharged from the axopodial surface just when the prey was captured.

Cytoplasmic Granules↗
PubMed2001

"You ate all that!?": caretaker-child interaction during children's assisted dietary recall interviews.

Young children's dietary recalls generally are conducted with a guardian present, but how this contributes to data accuracy is unclear. Furthermore, some assumptions underlying the preference for guardian presence may be unfounded. To investigate the range of guardian-child interactions within the diet recall setting, we examined transcriptions of guardian-assisted recalls conducted with 34 children aged 7-11 whose households were enrolled with the San Diego site of the Olestra Post-Marketing Surveillance Study (OPMSS). Although guardians did add to the breadth of data collected, children were quite knowledgeable about their diets. Moreover, they sometimes rejected guardian suggestions, and guardians generally could not provide assistance when children requested it. Guardian-child negotiations reflected cultural understandings regarding children, caretaking, and guardian-child power structures as well as food, and sometimes interviewers had to make very subjective data classification decisions. Suggestions for improving dietary recall methods are provided. Findings are relevant for other research methods involving children.

Adult↗
PubMed2003

Novel bilirubin-based PVC calcium sensors.

Poly(vinyl chloride) membrane sensors for Ca(II) ions were constructed based on bilirubin (1,3,6,7-tetramethyl-4,5-dicarboxyethy-2,8-divinyl-[b-13]-dihydrobilenone) as a neutral carrier in the presence of various plasticizers (o-nitrophenyloctyl ether, dioctyl phethalate and dibutyl sebacate), which were used as solvent mediators to incorporate the carrier into the membranes. The role of plasticizers as a medium of complexation was demonstrated. The influences of an anionic excluder, the pH and foreign ions were investigated. The selectivity coefficients were measured by a separate solution method. Among the plasticizers used, o-nitrophenyloctyl ether gave the best selectivity in the presence of large concentrations of alkali and alkaline earth's metal ions. Using sensor number I, a linear calibration graph with a good Nernstian slope of 29.5 +/- 0.8 mV was obtained for Ca(II) concentrations of 5 x 10(-7)-10(-2) mol l(-1) with a detection limit of 3 x 10(-7) mol l(-1) (12 ppb). The sensor can be used for more than 3 months with good reproducibility and a fast response time of 10 s. The developed sensor has been successfully applied to the analysis of some pharmaceutical formulations, baby-food products and human plasma. Moreover, it can be used as an indicator sensor in the potentiometric titration of Ca(II) with EDTA.

Bilirubin↗
PubMed1998

Glycated cholecystokinin-8 has an enhanced satiating activity and is protected against enzymatic degradation.

Monoglycated cholecystokinin octapeptide (CCK-8) (glucitol-Asp1 adduct) modified at the NH2-terminus was prepared under hyperglycemic conditions, purified by high-performance liquid chromatography, and characterized by mass spectrometry (Mr 1228.4 Da) and peptide sequencing. CCK-8 (100 nmol/kg, i.p.) significantly (P < 0.001) reduced voluntary food intake of fasted mice for up to 30 min after its administration, compared with saline-administered controls. Glycated CCK-8 reduced food intake at 30-120 min (P < 0.01 to P < 0.001) and significantly reduced feeding compared with CCK-8 from 60 to 120 min (P < 0.01). In vitro plasma degradation studies indicated that glycated CCK-8 was resistant to the normal rapid enzymatic conversion to CCK fragments. This study demonstrated that CCK-8 is a potent short-term inhibitor of food intake, and that structural modification of this peptide by amino-terminal glycation leads to enhanced satiating activity, partially due to increased resistance to serum aminopeptidase degradation.

Amino Acid Sequence↗
PubMed1984

[Ultrastructural observation of Naegleria fowleri trophozoite in mouse brain and axenic culture]

Present study was undertaken to elucidate the changes of the ultrastructure of Naegleria fowleri trophozoite in brain tissue of mice and culture medium. Naegleria fowleri, 0359 strain, which used in this study was cultured in axenic liquid medium, CGVS medium. Each mouse was inoculated with 1 x 10(5) amoebas intranasally under secobarbital anesthesia, and sacrificed on 7th day after the infection. Comparative observation of the ultrastructure of the amoebas in axenic culture and experimentally infected mice brain was done with transmission electron microscope. The results are summarized as follows: 1. The amoebas in mouse brain tissue were round in outline, whereas those of amoebas from axenic culture showed irregular appearance. 2. Mitochondria in the amoebas from axenic culture was oval, round and cylindrical shape and darkly stained, whereas those of the amoebas from mouse brain tissue showed dumbbell shape together with above forms. The stain was not unique, but light and/or dark. 3. Rough endoplasmic reticulum of amoebas in brain tissue was tubular, but from culture it was vesicular or tubular in shape. 4. Empty vacuoles were demonstrated in amoebas from culture, while food vacuoles with myelinated structures were abundant in those from tissue, suggesting a strong phagocytic activity. 5. Mouse brain tissue infected were extensively destroyed, and polymorphonuclear leukocytes were infiltrated predominantly with inflammatory lesion. Amoebas were observed in the vicinity of the capillary.

Journal Article↗
PubMed1995

Plasmodium vivax: freeze-fracture studies on the ultrastructure of the sporozoites within the salivary gland of the mosquito Anopheles stephensi.

Freeze-fracturing has been used to study the ultrastructure of the sporozoites of the malarial parasite Plasmodium vivax within the salivary gland of the mosquito Anopheles stephensi. The architecture of the pellicular complex of the salivary gland sporozoites was essentially the same as that reported for the intraoocystic forms, but the outline of cross-fractured P. vivax sporozoites was more flattened and crescent shaped as opposed to the circular outline described for the intraoocystic sporozoites. The salivary gland sporozoites of P. vivax also exhibited apical rosettes and a cytosome connected to a food vacuole, two unique structures not previously reported for malarial sporozoites.

Animals↗
PubMed1998

[Plant defense-related proteins as latex allergens].

Immediate-type allergic reactions to latex products made from natural rubber are called latex allergy. One of the notable features of latex-allergic people is their cross-reactivity to various vegetable foods and pollen. The structurally similar proteins which most kinds of plants potentially induce must be responsible for these cross-reactions. However, the taxonomical dissimilarity among the causative plants has kept us from concrete explanations of such cross-reactive allergens. We have speculated that plant defense-related proteins are a possible cause of the latex allergy. The well-known serologic relationships and sequence similarities of these ubiquitous plant proteins can explain the cross-reactivity without difficulty. Rubber trees cultured in plantation farms are repeatedly tapped and treated with phytohormones. These stresses would result in the significant induction of defense-related proteins. Indeed, we were able to detect defense-related enzymes in latex extracts. Moreover, three hydrolytic enzymes (beta-1,3-glucanase, chitinase/lysozyme, and carboxylesterase) that are very likely to take a defensive role were specifically recognized by the IgE antibodies of latex-allergic people and atopic patients. These experimental results strongly support our hypothesis. Because of their conserved structures, defense-related proteins should form a family of plant pan-allergens.

Allergens↗
PubMed2004

Raw versus cooked vegetables and cancer risk.

This review of the medical literature from 1994 to 2003 summarizes the relationship between raw and cooked vegetables and cancer risk and examines whether they may affect cancer risk differently. Twenty-eight studies examined the relationship between raw and cooked vegetables and risk for various cancers. Twenty-one studies assessed raw, but not cooked, vegetables and cancer risk. The majority of these assessed risk of oral, pharyngeal, laryngeal, esophageal, lung, gastric, and colorectal cancers. Most showed that vegetables, raw or cooked, were inversely related to these cancers. However, more consistent results were found for oral, pharyngeal, laryngeal, esophageal, and gastric cancers. Nine of the 11 studies of raw and cooked vegetables showed statistically significant inverse relationships of these cancers with raw vegetables, but only 4 with cooked vegetables. The few studies of breast, lung, and colorectal cancers also suggested an inverse relationship with both raw and cooked vegetables, but these results were less consistent. In the two studies of prostate cancer, there was no association with either raw or cooked vegetables. One of two bladder cancer studies found an inverse relationship with cooked, but not raw, vegetables. Possible mechanisms by which cooking affects the relationship between vegetables and cancer risk include changes in availability of some nutrients, destruction of digestive enzymes, and alteration of the structure and digestibility of food. Both raw and cooked vegetable consumption are inversely related to epithelial cancers, particularly those of the upper gastrointestinal tract, and possibly breast cancer; however, these relationships may be stronger for raw vegetables than cooked vegetables.

Case-Control Studies↗
PubMed1991

[Dietary intake of a representative sample of the population of Val-de-Marne: I. Contribution of diet to energy supply].

Dietary intakes and its nutritional value were assessed during a nutritional survey performed in a population living in a district in the Paris area (Val-de-Marne). Data were obtained from 1108 subjects, aged 6 months to 97 years, randomly selected from the telephone directories of 12 of 47 towns and cities in the district. Dietary intake was evaluated in individual home interviews conducted by specialized dietitians, using the dietary history method. Age appears to be an important determining factor in variations in nutritional intake. Large differences exist between men and women for most types of food consumption. But the relative contribution of the main groups of food groups to the structure of energy intake is very similar in both sexes and virtually constant in the different age groups after the age of 6.

Adolescent↗
PubMed1990

[The ultrastructure of the parietal mucosal layer of the small intestine].

With light and electron microscopy structure and composition of the small intestine parietal mucous layer of rat, chicken, and man were studied. It has been shown that parietal layer is complicated and multicomponent system includes mucous glycoproteins, vesicular and membrane structures, epithelial cells fragments, food substrates particles and bacteria. It is assumed that subepithelial mucous layer components may be of significance in premembrane digestion and absorption.

Animals↗
PubMed1990

Chronobiology and agroecosystems.

Influences of seasonal changes on the circadian system were observed in studies of feeding activity in four species of ducks and of feeding and locomotor activity in two species of mammals kept in captivity in the natural LD cycle. Feeding and locomotor oscillators had different sensitivities to exogenous synchronizers. Changes from a circadian to an ultradian feeding rhythm occurred as a result of courtship and breeding behavior in two duck species. Different phases of feeding rhythms in ducks were shown to have important ecological consequences for establishing the species in appropriate time niches in agricultural wetlands. Detailed study of annual, seasonal and daily rhythms of feeding and locomotion measured simultaneously in captivity and in free-ranging animals is necessary to elucidate the structure and function of food chains and webs. Activity rhythms of both producers and consumers (predators and prey) during daily and annual cycles is of special concern. This contribution of chronobiology will further our understanding of the niche of selected species in agricultural ecosystems.

Activity Cycles↗
PubMed1990

[The interdependence of age on the utilization of proteins and intake of fats of various quality].

From an age of 30 days to 150 days, male rats were given ad libitum feed with a physiological content of nutrients (adequate to their age) and with different sources of fat: sunflower oil, pork lard, butter. The net protein ratio (NPR), body fat content, and the specific activity of phosphoenolpyruvate carboxykinase PEPCK were determined every 15 days. For all the three fat sources, NPR had the same high values in the intensive growth period (age 45 and 60 days: increased protein demand for building the organism); lower and the same again are the NPR values at an age of 75 to 105 days. From an age of 120 days to 150 days (the end of maturation), the long-continued intake of lard and butter had an adverse effect on the availability of protein for the animals, though their food had a physiological structure and an optimum proportion of the saccharide components. The result correlates with the growth of PEPCK activity, as indicated by exploitation of protein as substrate for gluconeogenesis, not for proteosynthesis. Pork lard and butter with a 3.5 - to 5-fold prevalence of saturated fatty acids, compared with sunflower oil, implies that short-chain fatty acids were provided as effectors of gluconeogenesis and that, under the conditions of physiological intake of nutrients, substrates were also provided for mitochondrial synthesis of fatty acids.(ABSTRACT TRUNCATED AT 250 WORDS)

Aging↗