Contemporary pollen and seed dispersal in natural populations of Bertholletia excelsa (Bonpl.).

Due to the nutritional content and commercial value of its seeds, Bertholletia excelsa is one of the most important species exploited in the Amazon region. The species is hermaphroditic, insect pollinated, and its seeds are dispersed by barochory and animals. Because the fruit set is dependent on natural pollinator activity, gene flow plays a key role in fruit production. However, to date, there have been no studies on pollen and seed flow in natural populations of B. excelsa. Herein, we used microsatellite loci and parentage analysis to investigate the spatial genetic structure (SGS), realized pollen and seed dispersal, and effective pollen dispersal for two B. excelsa populations in the Brazilian Amazon forest. Two plots were established in natural forests from which adults, juveniles, and seeds were sampled. Realized and effective pollen flow was greater than realized seed flow. The distance of realized pollen dispersal ranged from 36 to 2060 m, and the distance of realized seed dispersal ranged from 30 to 1742 m. Both pollen and seeds showed a dispersal pattern of isolation by distance, indicating a high frequency of mating among near-neighbor trees and seed dispersal near to mother trees. Both populations present SGS up to 175 m, which can be explained by isolation by distance pollen and seed dispersal patterns. Our results suggested that fragmentation of these forest populations may result in a significant decrease in gene flow, due to the isolation by distance pollen and seed dispersal patterns.

The effect of live feeds bathed with the red seaweed Asparagopsis armata on the survival, growth and physiology status of Sparus aurata larvae.

Larval rearing is affected by a wide range of microorganisms that thrive in larviculture systems. Some seaweed species have metabolites capable of reducing the bacterial load. However, no studies have yet tested whether including seaweed metabolites on larval rearing systems has any effects on the larvae development. This work assessed the development of Sparus aurata larvae fed preys treated with an Asparagopsis armata product. Live prey, Brachionus spp. and Artemia sp., were immersed in a solution containing 0.5% of a commercial extract of A. armata (Ysaline 100, YSA) for 30 min, before being fed to seabream larvae (n = 4 each). In the control, the live feed was immersed in clear water. Larval parameters such as growth, survival, digestive capacity (structural-histology and functional-enzymatic activity), stress level (cortisol content), non-specific immune response (lysozyme activity), anti-bacterial activity (disc-diffusion assay) and microbiota quantification (fish larvae gut and rearing water) were monitored. Fish larvae digestive capacity, stress level and non-specific immune response were not affected by the use of YSA. The number of Vibrionaceae was significantly reduced both in water and larval gut when using YSA. Growth was enhanced for YSA treatment, but higher mortality was also observed, especially until 10 days after hatching (DAH). The mortality peak observed at 8 DAH for both treatments, but higher for YSA, indicates larval higher susceptibility at this development stage, suggesting that lower concentrations of YSA should be used until 10 DAH. The application of YSA after 10 DAH onwards promotes a safer rearing environment.

Titres of class-specific antibodies against Shigella and Salmonella lipopolysaccharide antigens in colostrum and breast milk of Costa Rican, Swedish and Vietnamese mothers.

Enzyme immunoassays (EIA) were used to estimate titres of class-specific antibodies against purified and chemically defined phenol-water-extracted lipopolysaccharide (LPS) antigens of Salmonella serogroup B (BO), Shigella dysenteriae type I, Plesiomonas shigelloides (the same O-antigen as Shigella sonnei) and Shigella flexneri Y. Titres in colostrum and breast milk of Swedish, Vietnamese and Costa Rican mothers from various socioeconomic conditions were compared. The antibodies were mainly of the IgA isotype. IgM antibodies were also present, but only very low concentrations of IgG were found. In Costa Rican mothers, the IgA antibody titres were significantly higher (P less than 0.05) in women of low and middle socioeconomical conditions than were those in mothers of high socioeconomical level. The low titres in the last group were comparable to those found in Swedish mothers. The IgA antibody titres found in Vietnamese mothers were similar to those of Costa Rican mothers from the low and middle socioeconomic conditions, being highest against S. flexneri Y LPS. The IgM antibody titres were also highest in Vietnamese mothers, immediately followed by the Costa Rican mothers of low socioeconomic conditions. The low IgM titres in the Costa Rican women of high socioeconomic level were comparable to those seen in Swedish mothers. The results suggest that, in Costa Rica and Vietnam, S. flexneri is the most prevalent Shigella sp. causing infection and that Salmonella serogroup B infections are rare in all three countries. The results also show that the antibody repertoire in colostrum and breast milk varies. Furthermore, in addition to the prevalence of a specific micro-organism in a determined geographical area, such differences may be associated mainly with exposure to certain pathogens in particular socioeconomic conditions.

[Solitary rectal polyp and endoscopic polypectomy in a pediatric population: 3 years' experience]. / Pólipo rectal solitario y polipectomía endoscópica en una población pediátrica: experiencia de 3 años.

During defecation, rectal polyps represent one most frequent causes of bleeding in infancy. The advent of endoscopic polypectomy has resulted very useful in their treatment. From January 1987 to March 1990, 113 children with rectal bleeding were evaluated; 22 of them had solitary rectal polyp, between 5 to 15 cm from anal margin at rectoscopy. 6 patients were excluded because they had autoamputation of the polyp, 16 patients, 9 girls and 6 boys between 2 and 11 years of age were studied with blood tests, series stools, contrast study with barium, colonoscopy with polypectomy and polyp histology investigation. 14 patients had chronic anemia, 10 had parasitic in stools. The barium enema identified rectal polyps in 14 patients (87.5%), colonoscopy and polypectomy was performed in every children. Juvenile histologic type predominated (82%). It is demonstrated that chronic anemia can follow rectal bleeding by polyps in children. Parasitic infections such as tricocephalous in conjunction with solid feces, may have a traumatic effect and produce chronic inflammation. Double contrast X-rays of the colon is useful to identify polyps. Non complications were observed during or after polypectomy. It is demonstrated that endoscopic polypectomy in children is a simple, safety and effective method.

Protection, energy and nutrients.

PIP: The advantages of breastfeeding are briefly summarized and some strategies for promoting breastfeeding, based on the results of recently conducted studies on Costa Rica and the Philippines, are described. Advantages of breastfeeding include 1) the presence of elements in human milk which provide protection against infectious diseases and other substances which make it difficult for bacteria to survive; 2) the electrolyte composition of breast milk makes it unnecessay to provide infants with water, thereby reducing the risks associated with drinking contaminated water; and 3) the biochemical composition of human milk which reduces the risk of aminoacid imbalance and facilitates the absorption of irom, zinc and other elements. Breastfeeding also encourages closer contact between the mother and the infant and facilitates the bonding process. In addition, breastfeeding is economically less costly than bottle feeding. Despite these advantages there is a trend toward bottle feeding in developing countries. Only traditional rural societies, eg, Bangladesh, Peru, and zaire, at present carry on universal breastfeeding. Studies in the Philippines and in Costa Rica demonstrate that this trend can be countered by interventions such as such rooming-in in maternity hospitals and by providing effective follow-up support for breastfeeding mother after they leave the hospital. In a large maternity unit in a Costa Rica hospital these intervention techniques proved highly successful. Before the intervention in 1977, 20% of the infants were never breastfed, and 66% of all infants were artificially feed at 3 months of age. After intervention, 95% of the infants were successfully breastfeeding during their hospital stay, and at follow-up 3 months later, 80% of the infants were still being breastfed. In another hospital study in Costa Rica preterm and high risk babies were feed from a colostrum pool and the incidence rates for diarrheal illness, sepsis, acute respiratory infection, and meningitis greately declined.^ieng

Sociocultural factors in the control and prevention of parasitic diseases.

Control and prevention of parasitic disease depends on an adequate knowledge of interactions among factors such as human behavior, the environment, and the life cycles of parasites. Sociocultural factors in large part determine transmission and persistence of parasites. The main determinants are poverty, low educational level, deficiencies in home technologies, high demographic density, and ruralism. Selected interventions designed to improve any of these situations may fail if they are applied in an isolated manner. The holistic implementation of interventions has proved successful in the control and prevention of parasitic infections in several parts of the word. The implementation of several kinds of interventions simultaneously, that is, a holistic approach, combined with an awareness of a society's infrastructure, can produce favorable results. For such an awareness--when it provokes action--can improve the overall quality of life.

Child malnutrition and deprivation--observations in Guatemala and Costa Rica.

Traditional populations consisting of small tribal groups living in close contact with nature may be virtually free from endemic malnutrition owing to the relative absence of infectious diseases. Transition toward modern ways of life and population growth, leading to crowding and underdevelopment, favours endemic malnutrition due to the interaction of malnutrition and infection. Although important features of the traditional culture--breast-feeding, protective child rearing--may remain intact, they are not enough, and such populations exhibit high rates of infectious disease, malnutrition and premature death. In modern industrialized societies, malnutrition often appears related to child abuse and neglect. Organic and metabolic forms are observed but social pathology appears to be the main determinant of most malnutrition observed. Prevention and control of malnutrition requires improvement of the environment and interventions applied in a holistic manner. Emphasis should be given to education and maternal technology, and to promotion of mother-infant interactions, breast-feeding, adequate weaning procedures and detection of factors that may lead to child deprivation and abuse. Improvement is feasible for most developing nations if social forces become conscious of the needed changes, but positive elements of traditinal culture should be preserved.

PIP: Traditional populations made up of small tribal groups living in close contact with nature may be virtually free from endemic malnutrition because of the relative absence of infectious diseases. Transition toward modern ways of life and population growth, resulting in crowding and underdevelopment, favors endemic malnutrition because of the interaction of malnutrition and infection. Attention is directed to 2 societies, the Guaymi aborigines who live in Villa Palacios in Costa Rica and who have satisfactory nutrition and the Maya Cakchiquel Indians who live in the Guatemalan highlands and who are experiencing malnutrition. The Guaymi live in dwellings scattered in the forests and jungles bordering Panama. The women deliver the babies at home in the traditional way, and breastfeeding is customary. These circumstances seem to ensure an adequate level of nutrition and health disturbed only by occasional epidemics of infectious diseases following the arrival of visitors or travel outside the village. Weaning was not studied in detail, but the healthy condition and stocky build of mothers would indicate that an infant's supply of human milk is adequate in the 1st year of life. Weaning begins after 6 months with the introduction of poorly prepared traditional foods. The diet is monotonous and, by Western standards and international dietary recommendations, poor in quality and quantity. The prevalence of stunting of infants was doubled in the 2nd year of life, but wastage (deficit in weight for height greater than 20%) was not observed, a situation contrasting with other Indian populations such as the Cakchiquels of Guatemala. Better nutrition and health may result from adequate child rearing practices in an environment relatively free of stress, especially infection, even in the absence of abundant and well balanced diets. The genesis of protein energy malnutrition (PEM) was observed during a study of infants from birth until school age in Santa Maria Cauque, a Maya Cakchiquel Indian village located in the Guatemalan highlands. This traditional village is in slow transition toward modern ways of life and resembles many other crowded and poor communities of Latin America. The dominant features of the village are socioeconomic underdevelopment, preservation of traditional ways of child birth and child rearing, and subsistence on traditional agriculture. Infection, particularly enteric, stands out as a primary determinant of PEM. The origin of PEM in societies in transition is frequently different from that described for traditional communities. Characteristics such as early mother infant attachment and breastfeeding have been disturbed by obstetric practices and artificial feeding, and there is a pronounced increase in social pathology, i.e., stress and anxiety, alcohol and drug consumption, family disruption, and aggression. In societies in transition intervention must recognize the origin and nature of the problem and holistic measures must be adopted.

S-IgA cholera toxin and rotavirus antibody in human colostrum.

S-IgA antibodies against cholera toxin and rotavirus were assayed in 43 colostral samples by means of an enzyme-linked immunosorbent assay (ELISA). All specimens contained specific S-IgA antibodies against both antigens. Significant antibody titres to the antigens were demonstrated in almost all colostral samples.

Epidemiology of human rotavirus Types 1 and 2 as studied by enzyme-linked immunosorbent assay.

To determine the relative importance of two known serotypes of human rotavirus, we developed an enzyme-linked immunosorbent assay to differentiate serotype-specific rotavirus antigen and antibody. Using this technic, we studied the epidemiology of the two serotypes in acute gastroenteritis. Seventy-seven per cent of 414 rotavirus isolates were Type 2, and the remainder were Type 1. The serotype distribution was similar in specimens from children in Washington, D.C., and other parts of the world. Sero-epidemiologic studies revealed that most children living in the Washington, D.C., area acquired antibody to both types by the age of two years. An analysis of children who were reinfected indicated that sequential infections usually involved different serotypes and that illness caused by one serotype did not provide resistance to illness caused by the other serotype. These results suggest that, to be completely effective, a vaccine must provide resistance to both serotypes.

[Diarrhea outbreak and bacterial resistance to ampicillin in newborns]. / Brote de diarrea y resistencia bacteriana a la ampicilina en neonatos.

Twenty-eight healthy neonates from the San Juan de Dios Hospital were studied to determine the pattern of antibiotic resistance of indigenous intestinal bacteria. Sixty-eight per cent of infants had enterobacteriaceae resistant to several wide-spectrum antibiotics, including ampicillin; 28 per cent of the cultures had plasmid-mediated ampicillin resistance. In the course of the study, an outbreak of 10 acute cases of diarrhea occurred, not associated to any of the commonly known agents, including the rotaviruses. Enterobacteriaceae multiple resistant were isolated from all cases; ampicillin-resistant strains were found in all; those resistances were mediated by transmissible plasmids. Several sites of the Neonatology Ward were sampled and two yielded E. coli with resistance to 8 drugs transmissible in vitro. The outbreak was controlled after strict hygienic measures were established in the ward. A following sample showed a decrease in indigenous antibiotic-resistant strains, especially E. coli; however, plasmid mediated resistant Klebsiella was still isolated several months later. The need to regulate the use of antibiotics; to educate the medical personnel and the public in general and to modify the hospital norms and regulations are discussed in the paper.

The environment of the malnourished child.

The study of the relation of man to his environment in developing countries emphasizes the inevitable need for societies to recognize the true causes of infection, malnutrition, and poverty. The need is for improvement in the quality of human life in less developed nations, a recommendation easy to prescribe but difficult to accomplish. Although our pool of knowledge is incomplete, it is adequate to suggest ways to diminish infection, increase food production, utilize food more efficiently, improve education, and provide systems of justice to protect the classes most in need. The physical environment in tropical and subtropical regions, and the socioeconomic characteristics of the population inhabiting such regions, favor maintenance and transmission of a variety of viruses, bacteria, and parasites that make agricultural progress and social development difficult, and that contribute to poor fetal growth, nutrient wastage, and deficient postnatal physical growth, accounting for most of the childhood morbidity and mortality. In this regard, infections contribute indirectly to the overall food problem in a similar fashion as pests do in terms of food losses and spoilage. The overall effect could be comparable or greater than that resulting from an inadequate capacity to produce or to purchase the food needed. Thus, my objective has been to stress, within the whole environment, the importance of infection and the need to diminish it. Ways to control and prevent infection are readily known. They have to do with education of the population to improve personal and environmental hygiene. Economic investment is necessary to improve housing and water supply systems, waste disposal, and such preventive measures as immunization programs. Although such measures may appear expensive when first implemented, they have long-lasting effects and many require minimal expenditure once they are established. Large segments of the population stand to benefit, and other development interventions can then be introduced. However, these measures should not be implemented singly. They should be accompanied by community development, family planning, social legislation--in other words, the holistic approach to health and welfare. To do otherwise may aggravate the problem by stimulating demographic growth, perpetuating malnutrition and infection, and maintaining underdevelopment.

The uniqueness of human milk. Host resistance to infection.

PIP: Field observations are reported which support an assumption that human breast milk acts benefically through induced host resistance to infection. Though the mechanisms of this induced host resistance to infection are not clearly understood, this article suggests the following factors as important: specific antibodies to infectious agents, influences stimulating or inhibiting certain intestinal microorganisms, and nonspecific antimicrobial factors. Immunoglobulins are present in human milk, with IgA representing the most abundant; the role of complement and immunoglobulin in induction of resistance to infection is well-known. Since all immunoglobulins have antibody activity, it is conceivable that immunoglobulins provide the material for antibodies to various etiological agents; for example, serum IgA contains all types of antibodies; serum IgG has a wide variety of antibodies to viruses, rickettsiae, protozoa, H antigens of Salmonella, and bacterial antitoxins and incomplete Rh antibodies; and the IgM fraction contains antibodies to O antigens of Enterobacteriacae, Rh agglutinins, and syphilis reagins. Another aspect of human milk as an inducer of host resistance is the bifidus factor which promotes development of characteristic microflora; since the bifidobacteria metabolize a variety of sugars, producing large amounts of acetic and lactic acids and trace amounts of formic and succinic acids, these organisms affect pH and, hence, certain resistance factors. Other factors present in milk include lysozyme (muramidase), complement, interferon, and immune cells, all of which promote host resistance to infection.^ieng