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Biomedical subjects

E Sievers

Publications and source records attributed to E Sievers.

33 records · Page 2Linked to original sources

Cerebrospinal fluid concentrations of leukotriene B4 in bacterial meningitis.

We investigated whether leukotriene B4 (LTB4), a granulocyte inflammatory mediator, is detectable in cerebrospinal fluid using a high performance liquid chromatographic method. In non-pleocytotic cerebrospinal fluid (n = 5) and in cerebrospinal fluid from children with aseptic meningitis (n = 8), LTB4 concentrations were below the detection limit (< 0.2 ng ml-1). In the range 0-20 ng ml-1, the recovery rate of LTB4 that had been added to non-pleocytotic cerebrospinal fluid was > 90%. In cerebrospinal fluid with a polymorphonuclear leucocyte (PMN) count higher than 1,000/ml, LTB4 was detectable in six out of seven specimens with a concentration of 0.35-3.3 ng ml-1. LTB4 concentration was significantly correlated with PMN number. These results, together with observations in animal models, are discussed with regard to a pathophysiological role of LTB4 in bacterial meningitis.

Child↗

Pancreatic contrast enhancement with Mn-bis pyridoxal ethylene diamine diacetic acid and the influence of a hormonal stimulation of the pancreas in pigs.

RATIONALE AND OBJECTIVES: Pancreatic and hepatic contrast enhancement after different modes of administration of Mn-bis pyridoxal ethylene diamine diacetic acid (Mn-DPDP) and the influence of the hormones secretin and cholecystokinin on the uptake of this new contrast agent were studied by using magnetic resonance (MR) imaging and atomic absorption spectroscopy (AAS) examinations carried out on 13 young domestic pigs. METHODS: Mn-DPDP was administered either as bolus injection or 30-min infusion. The course of contrast enhancement was noted. MR imaging was carried out with or without pancreatic stimulation. The Mn content in pancreatic and hepatic tissue was analyzed by using AAS. RESULTS: Mn-DPDP caused a significant increase (66 +/- 40.1%) in pancreatic signal intensity, an increase in hepatic signal intensity (78 +/- 23.0%), and a significantly higher Mn content on tissue samples of both organs. The results showed a wide individual range. With infusion of Mn-DPDP, pancreatic enhancement was slower, with a peak at 82 +/- 34 min compared with 54 +/- 51 min following bolus injection. The Mn content of both hepatic and pancreatic tissue determined by AAS seemed to be higher after infusion. An incomplete washout of Mn after 24 hr was demonstrated. Hormonal stimulation of the pancreas further increased pancreatic signal intensity but did not influence hepatic contrast enhancement. CONCLUSION: Infusion is the method of choice for administering Mn-DPDP because it causes an increase in hepatic signal intensity but does not change pancreatic enhancement. Although pancreatic hormonal stimulation intensifies enhancement, the increase is not statistically significant, and this practice will not contribute to day-to-day clinical practice.

Animals↗

Amplification of a Y-chromosomal DNA sequence by the polymerase chain reaction for documentation of residual recipient cells in small samples from bone marrow, peripheral blood and cerebrospinal fluid after bone marrow transplantation.

The long arm of the human Y-chromosome contains about 800 to 5000 copies of the tandemly repeated DNA sequence DYZ1. A major part of the repeating unit (pHY10) has been cloned and sequenced. Primers were designed to match a part of this repeat sequence for the amplification of a 154 bp fragment spanning the EcoRI restriction site of the unit. Typical dilution experiments showed that this polymerase chain reaction (PCR) method allows the detection of 5 to 10 male cells among 100,000 female cells, or in 500 microL of cerebrospinal fluid containing only one cell per microL. In addition, the quality of the DNA used for the amplification reaction is less critical, thus allowing analysis of long-term stored samples such as bone marrow smears or dried blood stains spotted onto filter paper, which might contain partially degraded DNA. We applied this technique to detect residual host cells in the clinical setting of human sex-mismatched bone marrow transplantation (BMT). Fourteen patients, receiving transplantations because of leukemias could be supervised so far. Throughout the whole period of monitoring (days +14 until +911 post BMT; median: 160 days), residual host cells were detected in all but three patients. Persistence of host cells in the early phase post-BMT was mostly transient and probably due to long-term surviving host T-lymphocytes. Reappearance of host cells several months after BMT is highly suspicious of relapse from the underlying malignancy. Due to its high sensitivity, PCR is a valuable tool in monitoring the switch from recipient to donor cell population.(ABSTRACT TRUNCATED AT 250 WORDS)

Base Sequence↗

Faecal excretion in infants.

Data on normal defaecation patterns in relation to diet during the first months of infancy are very limited. We therefore investigated in a prospective study faecal weight and gastro-intestinal passage time of breast fed (n = 12) and formula fed (n = 14) male infants. These were studied in 72 h collecting periods at the age of 17, 35, 57, 87 and 113 (+/- 4) days. Breast fed infants had a significantly lower daily dry faecal weight than formula fed infants in all periods investigated (median at the age of 113 days: 0.28 (0.17-0.75) g/kg and 0.81 (0.22-1.2) g/kg, respectively). Breast fed infants showed a large variation of gastro-intestinal passage time (6.79 h [range: 1.79-13.38 h] at the age of 17 days, 21.84 h [range: 5.41-75 h] at the age of 113 days). Comparable values of formula red infants were 13.75 h (range: 7.13-35.25 h) and 17.42 h (range: 5.38-36.5 h). Despite the efforts of approximation of infant formula to breast milk, differences of defaecation patterns in relation to diet are still relevant at this age and have to be considered in clinical practice.

Breast Feeding↗

Antibody-dependent cellular cytotoxicity and neutralizing activity in sera of HIV-1-infected mothers and their children.

The prognostic and protective role of antibodies mediating cellular cytotoxicity (ADCC) and neutralization was evaluated in sera of HIV-1-infected mothers and their consecutively followed children. The presence and titres of ADCC mediating and/or neutralizing antibodies in maternal sera did not predict HIV-1 infection in their respective children. No significant difference in the sera from the children was seen when comparing the presence of neutralizing antibodies between the uninfected and infected children. Stratification of the infected group according to clinical status revealed differences. Only one of 24 AIDS patients had a high neutralizing titre against IIIB. Four patients had a very low titre and the remaining had no detectable neutralizing antibodies at all. In contrast, 10/17 infected non-AIDS children had neutralizing antibodies. Similarly, no significant difference was seen when comparing the presence of ADCC-mediating antibodies between the uninfected and the infected group of children. However, a significantly higher frequency of ADCC was seen in the seropositive non-AIDS children compared with the AIDS children. This study clearly shows that the presence of antibodies mediating ADCC and neutralization in infected children, 0-2 years old, is associated with a better clinical status and delayed disease progression.

Acquired Immunodeficiency Syndrome↗

Urinary excretion of epidermal growth factor and transforming growth factor-alpha in breast-fed and formula-fed infants.

Urinary epidermal growth factor (EGF) and transforming growth factor-alpha (TGF-alpha) concentrations were determined by radioimmunoassay in a longitudinal study analyzing 348 24-h urine specimens of 32 infants (16 breast-fed, 16 formula-fed) during the first 16 weeks of life. EGF excretion showed a statistically significant increase from 6.0 +/- 2.5 to 14.1 +/- 4.9 micrograms/g creatinine (mean +/- 1 SD) during the investigation period. TGF-alpha levels were fairly constant throughout this period. Comparing breast-fed infants, with more than 100-fold higher ingestion of EGF and TGF-alpha, with formula-fed infants, no significant differences in urinary EGF and TGF-alpha excretion were observed. These results do not rule out a systemic effect of EGF and TGF-alpha after intestinal absorption in breast-fed infants. The results suggest, however, that urinary EGF and TGF-alpha originate mainly from sources other than intestinal absorption.

Bottle Feeding↗

Longitudinal zinc balances in breast-fed and formula-fed infants.

Longitudinal zinc (Zn) balance studies were performed under domestic conditions in term breast-fed (n = 10), term formula-fed (n = 5; Zn concentration in the formula: 4 mg/l) and preterm formula-fed (n = 3) infants during the first 17 weeks of life. Samples of milk, urine and feces were analyzed by atomic absorption spectrometry. The median daily Zn intake in breast-fed infants decreased from 0.592 (0.457-0.829) mg Zn/kg body weight to 0.151 (0.095-0.304) mg Zn/kg body weight in the first 17 weeks of life; comparable values for bottle-fed term infants were 0.58 (0.511-0.701) and 0.674 (0.529-0.731) mg Zn/kg body weight. The median percent retention of Zn intake was 27 (-60 to 81.4)% in breast-fed infants and 21.5 (-42 to 64)% in formula-fed infants. In view of the urinary and fecal Zn losses measured, a daily intake of 0.3-0.5 mg Zn/kg body weight is considered to be sufficient to ensure a Zn retention equivalent to breast-fed infants. This requires a Zn concentration of 2-3 mg/l of Zn depending on milk volume intake.

Bottle Feeding↗

[Sodium and potassium metabolism in infancy].

BACKGROUND: Recommendations for the concentration of most nutrients in infant formulas are based on their concentration in human milk. Industry succeeded in adapting sodium and potassium content in infant formulas to concentration found in human milk. Whether this adaptation affects on infants' mineral balances was studied in breast-fed and artificially-fed infants. METHODS: Sodium and potassium balances were performed in 16 term male infants from their 3rd until their 17th week of life. The balances were performed at home and comprised up to five periods in intervals of three to four weeks. Each balance period consisted of subsequent three 24 h collections of milk, stool and urine samples. Ten infants were breast-fed, six received an adapted infant formula supplemented with copper, zinc and iron. RESULTS: The breast-fed infants got a mean intake of 1 mmol Na/kg b w x day and a mean intake of 1.8 mmol K/kg b w x day. Man retention was 0.4 mmol Na and 0.7 mmol K/kg b w x day. The formula-fed infants received 1.9 mmol Na/kg b w x day and 2.1 mmol K/kg b w x day. Na- and K-retention in this group was 0.5 and 0.6 mmol/kg b w x day respectively. Although sodium intake in the formula-fed infants was nearly twice as much as in the breast-fed infants the difference in sodium retention was only small (0.4 vs 0.5 mmol/kg b w x day). The formula-fed infants got more potassium than the breast-fed infants, but potassium retention was the same in both groups. CONCLUSIONS: With the adapted infant formula of this study the artificially fed infant was as well supplied with sodium and potassium as the breast-fed infant. A further reduction of the sodium concentration seems not to be useful.

Animals↗

Iron availability from an infant formula supplemented with bovine lactoferrin.

Iron balance studies were performed in 16 term infants from their 3rd until their 17th week of life. The balance studies were performed at home and comprised five periods with an interval of 3 to 4 weeks, each consisting of three 24-hour collections of milk and stool samples. Seven infants were fed an adapted infant formula supplemented with bovine lactoferrin (100 mg/100 ml) and nine received the same formula without lactoferrin. The lactoferrin supplemented group received 169 micrograms iron/kg b.w. x day and retained 63 micrograms/kg b.w. x day. The mean iron intake of infants fed with the adapted formula without supplementation of lactoferrin was 118 micrograms/kg b.w. x day. The retention of iron was 43 micrograms/kg b.w. x day. Mean percentage retention of iron in the supplemented group was 36%, in the non-supplemented group 28%.

Biological Availability↗

Trace element excess in PKU diets?

Knowledge of trace element requirements of infants with phenylketonuria (PKU) fed a semisynthetic diet is limited. Three infants with PKU detected early were studied longitudinally in classical balance studies for 72 h, under domestic conditions, at the ages of 2, 5, 8, 12 and 16 weeks. Iron, copper and manganese concentrations in the diet and faeces were determined by atomic absorption spectroscopy. The median concentrations in the diet (4.8 mg Fe/L, 1.7 mg Cu/L, 0.43 mg Mn/L) exceed those in human milk. This is mainly due to supplementation of the amino acid preparation used. The increased intake led to a significantly higher daily retention of Cu and Mn from the PKU-diet fed, with a median of 0.17 mg Cu/kg and 6.4 micrograms Mn/kg body weight; the median retention of Fe was 0.24 mg Fe/kg. Our results confirmed the doubts about the suitability of the present trace element supplementation in formula for infants with PKU during the first four months of life.

Body Burden↗

Urinary zinc excretion in infancy.

In view of the conflicting data on urinary Zn excretion in infancy we investigated the possible influence of contamination, collecting methods, nutrition (human milk versus formula) and longitudinal changes during the first 16 weeks of life. Methodical investigation showed that special attention is necessary to avoid contamination due to the use of Zn-containing baby creams in the genital region. The sampling device for collection should include the smallest area of skin possible and the use of Zn-containing baby creams has to be avoided both during the collection and at least 24 hours prior to urine collection. Previous fractional urine sampling of the collecting method to be evaluated proves that erroneously high values are not obtained at the beginning of collection. Midstream urinary samples reduce the possibility of contamination. Increased urinary excretion was shown in pre-term infants under theophylline or coffeine medication. The median daily urinary Zn excretion in healthy breast-fed term infants declined significantly from 0.063 (0.027-0.111) mg per kg body weight at the age of 2 weeks to 0.018 (0.004-0.059) mg per kg body weight at the age of 16 weeks. Comparable values for formula-fed term infants were 0.029 (0.025-0.063) mg per kg body weight initially and 0.025 (0.007-0.059) mg per kg body weight at the end of the study. These values can be used as reference values for the urinary Zn excretion of healthy infants.

Aging↗

Selenium balances in young infants fed on breast milk and adapted cow's milk formula.

Selenium intake, renal and fecal excretion, and retention were determined in 11 breast-fed term infants and in 9 term infants fed with an adapted cow's milk formula. In most cases three-day-balances were determined five times at the age of 2, 5, 8, 12, and 16 weeks. Analytical determination of selenium was by atomic absorption spectroscopy with a selenium hybrid system after wet ashing of samples. The mean breast milk concentrations of selenium show a significant decrease in the course of lactation from 31.0 micrograms/L in the first collecting period to 17.6 micrograms/L in the last one. The two formula milks contained 11.8 and 7.7 micrograms/L. Intake in the breast milk group was higher than in the formula group, whereas absolute renal and fecal excretion were essentially the same. This leads to a higher selenium retention in the breast-fed infants than in the formula-fed infants, where most of the balances are negative.

Adult↗

Longitudinal manganese and copper balances in young infants and preterm infants fed on breast-milk and adapted cow's milk formulas.

1. Mn and Cu intake and retention in twenty full-term infants and six preterm infants were studied on the basis of 72 h balances. The age of the infants was 2-16 weeks and the gestational age of the preterm infants (triplets) 34 and 36 weeks. Three nutrition schemes were pursued: breast-fed, formula-fed with unsupplemented adapted formula and formula-fed with trace element supplementation. 2. The mean Mn concentration of all breast-milk samples (n 2339) was 6.2 micrograms/l. The two formulas had similar Mn concentrations (77 and 99 micrograms/l) but had different Fe, Cu (121 and 619 micrograms/l), Zn and I contents. The mean Cu concentration in mother's milk was 833 micrograms/l. 3. The following mean daily Mn intakes and retentions (micrograms/kg) respectively were measured: breast-fed full-term 1.06 (SD 0.43) and 0.43 (SD 0.65), formula-fed full-term 14.2 (SD 3.1) and 2.8 (SD 4.8), formula-fed preterm 15.0 (SD 2.2) and 0.06 (SD 5.87). The results for Cu were 114.5 (SD 22.3) and 88.0 (SD 46.5) micrograms/kg in breast-fed, 19.8 (SD 4.2) and 4.6 (-11.5-9.6) in the unsupplemented formula-fed and 106.4 (SD 18.9) and 55.5 (SD 20.3) in the supplemented formula full-term infant group. No significant influence of the trace element contents of the formulas on the relative retention of Mn or Cu was found. 4. Young preterm infants, and to some degree young full-term infants, often had negative Mn balances caused by a high faecal excretion. The formulas with a Mn concentration below 100 micrograms/l gave a sufficient supply of Mn. Preterm infants fed on the unsupplemented formula had a marginal Cu supply and their first balances were negative (-3.8 (SD 1.8) micrograms/kg). 5. In accordance with the estimated safe and adequate daily dietary intakes (recommended dietary allowances), formula-fed infants receive much more Mn than breast-fed infants and their absolute retention is higher. 6. Cu from breast-milk had a significantly better biological availability than that from cow's milk formula. If retentions similar to those in breast-fed infants are intended, we conclude, therefore, that cow's milk formula should be fortified with Cu up to a level of at least 600 micrograms/l.

Animals↗