Parental experiences of their infant's hospitalization for cardiac surgery.

BACKGROUND: Parents are increasingly recognized as important partners in children's health care. Despite their involvement in care, parental experiences of their child's hospitalization have received little research attention. In this study we explored parents' perceptions of what they found difficult, what they would like to be different and what they found to be helpful during their infant's hospitalization and surgery for the treatment of congenital heart disease. METHODS: Structured interviews were conducted with 154 parents (91 mothers, 63 fathers) whose infant underwent cardiac surgery (at <3 months of age) 1 month post discharge from hospital. Thematic and frequency analyses were performed. RESULTS: Parents reported a range of difficulties from dealing with their baby's unfolding illness, surgery and recovery to the structural and systemic issues associated with the broader context of their experiences. In an effort to be near their baby, parents struggled to obtain the necessities for daily living at the hospital and negotiate transitions between their hospital and home lives throughout the admission. Domains parents identified for change included the availability of facilities and resources and the quantity and quality of information and emotional support. Parents reported relationships with hospital staff as the most common source of support during this challenging time. CONCLUSIONS: Opportunities to improve parents' experiences when their infant is in hospital exist at an organizational level as well as at the clinical level. The significance of parents' relationship with hospital staff indicates the potential for each professional to impact on families' experiences on a daily basis. The range of challenges indicates the scope and need for allied health services.

Trace elements in some human milk samples by radiochemical neutron activation analysis.

Some trace element contents of samples of human milk, mainly colostrum and transitional milk, collected in the Ljubljana area of Yugoslavia, are reported. Analyses of As, Cd, Co, Cu, Hg, I, Mn, Sb, Se, Sn, V and Zn were performed by radiochemical neutron activation analysis, and the results are discussed briefly in the light of literature values.

Contamination as a limiting parameter in trace analysis.

The relative importance of the main parameters determining systematic errors due to contamination in trace analysis is evaluated, with respect to the laboratory environment, tools, containers and reagents. Variability in the composition and quality of materials as well as of the relevant analytical data makes the treatment of the subject only semi-quantitative but the evidence suggests that control over contamination primarily depends on good laboratory practice. Among the appproaches applicable to trace concentrations, activation analysis gives results that are least affected by contamination. In other techniques, varying blanks and the need for their control make accurate analysis at the trace level demanding in terms of time and engagement; reliable data in routine determinations at levels much below 1 mg/kg can only be expected from specialized and experienced laboratories.

Amperometric determination of cyanide by use of a flow-through electrode.

A new approach to cyanide determination based on the measurement of the diffusion current arising from the oxidation of silver to dicyanoargentate(I) is described. Parameters defining the effect of the electrode geometry and the hydrodynamic characteristics of the system on the response of the electrode have been evaluated so that the performance can be optimized. Response is fast and linear for levels from one microgram to several grams per litre of solution. By use of the flow injection principle and a manifold arrangement, absolute amounts of less than one nanogram of cyanide can be determined precisely in volumes as small as 10 mul and at a rate exceeding 100 samples per hour. The method is easily adapted to automated routine analytical control and continuous monitoring of industrial processes depending on the use of cyanide, such as galvanizing plants and certain organic synthetic industries, and also to control of effluents.

The intestinal phase hormone.

The existence of a stimulatory intestinal phase of gastric acid secretion has been suspected, but largely ignored, for many years. Recently, however, it has become clear that the intestinal phase plays an important role in acid production during digestion. The intestinal phase is of additional interest in relation to the profound gastric acid hypersecretion associated with portacaval shunt (PCS). Substantial evidence indicates that PCS-related gastric hypersecretion is due to unmasking of the intestinal phase by hepatic bypass of a humoral stimulant in portal blood that is normally degraded to a considerable extent by the liver. Studies in our laboratory during the past 12 years have provided strong physiologic evidence for humoral mediation of both the intestinal phase of gastric secretion and of PCS-related hypersecretion by a hormone that arises in the small intestine, particularly in the jejunum. Furthermore, our studies have demonstrated that this intestinal phase hormone (IPH) exists in humans as well as in dogs, rats, and pigs. Additionally, recent work by a number of investigators, as well as by our group, has provided convincing evidence that IPH is different from any of the known gastric stimulatory hormones. With these physiologic observations as a background, we have used a classical method for extracting acidic peptides to prepare a hog intestinal mucosa extract (HIME) that has all of the known physiologic properties of an IPH. Specifically, HIME contains a potent stimulant of gastric acid secretion that acts according to a linear dose-response relationship; that is not gastrin in any of its immunoassayable forms; that significantly augments the maximal acid secretory responses to pentagastrin, gastrin, CCK, and histamine; and that is substantially degraded by the liver, in contrast to gastrin and CCK. Efforts at isolating the gastric stimulatory substance in HIME suggest that it is a peptide of low molecular weight. Work directed at isolating IPH in pure form and identifying it is in progress.

On the vanadium and tin contents of diet and human blood.

The vanadium and tin contents of total diet samples collected in five Italian towns are given, and discussed in relation to literature data, their status as essential elements and their levels in human blood. Tin in blood was found to be below 2 ng ml-1 in a group of 14 subjects, and barely detectable even after oral consumption of 60 mg of tin.

Vanadium in foods and in human body fluids and tissues.

Using neutron activation analysis, vanadium was analysed in a range of foods, human body fluids and tissues. On the basis of these results and those of other workers, it was concluded that daily dietary intake amounts to some tens of micrograms. Analysis of body fluids (including milk, blood and excreta) and organs and tissues provided an estimate for the total body pool of vanadium in man of about 100 microgram. Vanadium was not detectable in blood and urine at the level of 0.3 ng/g, while low levels were found in muscle, fat, bone, teeth and other tissues. The relationship between dietary intake to pulmonary absorption is discussed in relation to the occurrence of vanadium in man-made air particulates. The very low levels found in milks and eggs suggest minimal vanadium requirements in growth. The findings are discussed in the light of previous results and also in relation to the possible essentiality of vanadium.

Criteria for selection of patients for emergency portacaval shunt.

A computer program analysis of the effect on survival of 74 preoperative factors was performed as part of a prosepctive study of the emergency portacaval shunt in 146 unselected patients with bleeding esophageal varices due to alcoholic cirrhosis. Only ascites, a serum glutamic oxalacetic transaminase level of 100 units or more, and a requirement for 5,000 ml or more of blood transfusion were associated with a statistically significant decrease in survival. However, none of these factors are contraindications to operation because their presence permits a survival rate of 37 to 40%. The only contraindication to emergency portacaval shunt is the combined presence of ascites, jaundice, encephalopathy, and severe muscle wasting, a constellation that was incompatible with survival beyond one year.

Amperometric study of some effects in the precipitation of lead and barium chromates.

Amperometric titration has been applied to study parameters determining the extent of mutual co-precipitation of lead and barium in the formation of their chromates. The anomalous behaviour of dichromate due to repulsion at the dropping mercury electrode, which severely affects the precision of the measurements, has been eliminated by addition of tetrabutylammonium hydroxide. By this modification the amperometric end-point detection has been extended to higher concentrations of the reagent and a wider pH range of the medium as required for this study. Shifts in the distribution of chromium species, slow evolution of the precipitate and, in the case of lead, its varying composition, all depend on pH and ionic strength. They have been identified as limiting factors in the amperometric titration of lead and barium and optimum conditions found for their determination. The applicability of the technique to practical analysis is limited, but in the absence of ions which precipitate at the required pH, it permits precise and accurate titration of lead in the presence of barium at pH 2-3 and of their sum at pH 5-6.

Determination of traces of indium, manganese, arsenic and antimony in zinc by neutron-activation analysis.

Destructive activation determination of the trace elements indium, manganese, arsenic and antimony in different samples of pure zinc metal by solvent extraction techniques is described. Determination of indium and manganese is based on the quantitative co-precipitation of both elements with lanthanum hydroxide, followed by their extraction with sodium diethyldithiocarbamate in the presence of potassium cyanide and their subsequent separation by selective stripping. The quantitative determination of arsenic and antimony is based on the extraction of their iodides from sulphuric acid solution with toluene.

Trace element concentrations in higher fungi.

The concentrations of ten trace elements, As. Br, Cd, Cu, Hg I, Mn, Se, Zn and V, have been determined in up to 27 species of higher fungi from several sites in Slovenia, Yugoslavia. Analyses were based on destructive neutron activation techniques. Data are presented and compared with the concentrations found in soils. Previously values were non-existent or scanty for these elements, so that the data represent typical levels for basidiomycetes. In addition to confirming high levels of mercury in many species, the survey also found that cadmium is accumulated to a surprising extent by most fungi, the average value being 5 ppm. Among other accumulations found was bromine by the genus Amanita, and selenium by the edible Boletus. Correlation analysis between all pairs of trace elements gave values for r of from 0.75 to 0.43 for 7 pairs (Cu and Hg, 0.75; Se and As, 0.69). As well as these features of biochemical interest, the values found and the pattern of accumulation suggest potential uses of fungi in environmental studies.

The occurrence of mercury in amphibia.

Studies have been made of the distribution of mercury and its occurrence as methylmercury in the organs of amphibia collected from different sites mainly in Slovenia, Yugoslavia, including the area around the mercury mine at Idrija. Liver accumulates the highest amounts of mercury, up to 2 ppm in apparent background areas, with values up to 0.5 ppm in muscle, where virtually all mercury is present in the methyl form. Results are reported for some other trace elements in liver. Amphibia may provide useful monitors of the occurrence and spread of mercury contamination.

Simultaneous neutron-activation determination of selenium and mercury in biological samples by volatilization.

A method is described for the determination of selenium together with mercury in biological samples by neutron-activation analysis based on quantitative volatilization of both elements. The technique originally developed for mercury, based on pyrolysis with filtration of undesirable impurities and selective trapping from the gas phase, is now extended to selenium. The radionuclides (197)Hg and (75)Se, from one sample, are trapped separately and counted in a well-type NaI(Tl) detector and gamma-spectrometer for maximum sensitivity. The method has been tested by comparative analyses and analyses of standard biological materials, and gives good results. It is simple and is especially effective in studies of the interaction of mercury and selenium in biological systems; a positive correlation for these elements was found for human tissues. On décrit une méthode pour le dosage du sélénium conjointement au mercure dans les échantillons biologiques par analyse par activation de neutrons basée sur la volatilisation quantitative des deux éléments. La techniqu initialement développée pour le mercure, basée sur la pyrolyse avec filtration des impuretés indésirables et captage sélectif de la phase gazeuse, est maintenant étendue au sélénium. Les radionuclides (197)Hg et (75)Se, d'un échantillon, sont captés séparément dans un détecteur NaI(Tl) du type puits et un spectromètre gamma pour la sensibilité maximale. La méthode a été essayée par des analyses comparatives et des analyses de produits biologiques étalons, et donne de bons résultats. Elle est simple et particulièrement efficace dans les études de l'interaction du mercure et du sélénium dans des systèmes biologiques; on a trouvé une corrélation positive pour ces éléments pour des tissus humains.

A new method for the isolation of methylmercury from biological tissues and its determination at the parts-per-milliard level by gas chromatography.

A new method has been developed for the isolation of methylmercury from biological tissue. It is based on the volatilization of methylmercury cyanide formed in the reaction of methylmercury in the tissue with hydrocyanic acid released in the interaction of potassium hexacyanoferrate(II) with sulphuric acid at elevated temperature. The methylmercury cyanide released is captured on cysteine paper in a microdiffusion cell. The isolated methylmercury is set free with hydrochloric acid, extracted into benzene and determined by gas chromatography. A special closed micro-extractor is used for the final extraction into benzene for samples containing the lowest levels of methylmercury. The method can be used for a wide range of samples and concentrations (including background levels). The simplicity of the method makes it suitable for routine application.

Activation analysis for mercury in biological samples at nanogram level.

A new method has been devised for determining mercury in samples of biological origin. It is based on complete ignition of the sample in a silica tube, trapping volatile interfering activities such as bromine or chlorine, and selectively adsorbing mercury on a strip of filter paper which has been previously impregnated with elemental selenium. This strip is later counted for quantitative evaluation. The versatility of the method has been demonstrated by the analysis of a wide range of samples such as water, cellulose, flour, fish solubles or animal blood samples with mercury contents between 1 and 200 ng g of sample.