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Biomedical subjects

W Heine

Publications and source records attributed to W Heine.

At least 37 records · Page 2Linked to original sources
PubMed1992

[Phosphate concentration. Does reduction in infant formula feeding modify the micro-ecology of the intestine?].

The potential influence of phosphates in formulas on intestinal microflora was studied in 25 infants, aged 8 days to 12 weeks. The babies were either fed an infant formula with the usual phosphate concentration (n = 10) or an infant formula with reduced phosphate and protein concentrations (n = 7). The microbiological findings were compared with those obtained from breastfed infants (n = 8). Low-phosphate concentrations did not correlate with a predominance of bifidobacteria or suppression of putrefactive bacteria in the feces. The fecal excretion of phosphates and fat was found to be significantly lower with mother's milk compared to formulas both rich and poor in phosphate. Protein synthesis and breakdown rates, as well as the net protein gain, did not have a significant correlation with protein intake.

Bifidobacterium↗
PubMed1992

Host-microflora correlations in infant nutrition.

The intestinal microflora represents an enormous cell mass and has a high metabolic capacity. The symbiotic efficacy of these microbes in humans is still a matter of discussion. Of particular interest, from a biogenetic point of view, are potential symbiotic relations between the bifidobacterial microflora and the breast-fed infant. Our group has conducted studies related to this topic; they were aimed at determining the dimension of microbial assimilation by the host. Our studies with 15N-labeled bifidobacteria have shown that the bifidobacterial microflora is capable of upgrading nonessential nitrogen such as urea nitrogen for the synthesis of microbial protein. Oral single pulse labelings with 15N-labeled bifidobacteria were absorbed to approximately 90% and retained in the infant's protein pool to approximately 70%. These findings demonstrate the high intensity of the substrate flow from the microflora to the host. This might become important under conditions of marginal food protein intake or during periods of accelerated growth.

Animals↗
PubMed1991

Symbiotic interactions between colonic microflora and protein metabolism in infants.

The utilization of 15N nitrogen from 15N-labelled bifidobacteria for whole body protein synthesis was studied in 4 infants by oral single-pulse labellings and in 3 other infants, who had colostomies, by colonic pulse labellings. The bifidobacteria were harvested from a modified Petuely culture medium containing 15N ammonium chloride and 15N cystine as the only sources of nitrogen. The tracer dose chosen for the balance studies was 3 mg 15N/kg. 15N concentrations in urine and feces collected over 48 hours after the pulse labellings were determined by emission spectrometry. Oral administration of 15N-labelled bifidobacteria resulted in absorption of approximately 90% renal excretion of 15%, and fecal excretion of 12% of the tracer dose, respectively. Retention in the protein pool averaged 73%. After colonic single pulse labelling with 15N-labelled bifidobacteria, the corresponding values were 85.5%, 2.2%, 14.5% and 83.0%, respectively. Absorption and incorporation of the heavy nitrogen into body proteins were directly demonstrated by increased 15N atom percent excess values within the trichloroacetic acid (TCA) supernatants and the proteins of the plasma, 0.25 and 0.04 atom%, respectively, at 24 hours after oral pulse labellings. One half of the total 15N excreted in urine consisted of urea and approximately 8% was eliminated as ammonia.

Bifidobacterium↗
PubMed1991

[Carbohydrates in parenteral nutrition solutions in pediatrics--a critical evaluation].

Application of carbohydrates in pediatric infusion therapy has recently been limited to glucose and xylitol. Fructose and sorbitol, which formerly had been used widely as energy sources in parenteral nutrition, have meanwhile been banned in order to prevent fatal complications in patients with undiscovered hereditary disturbances in fructose metabolism. The aim of this review is to focus the attention on potential side effects and limitations of glucose administration in pediatric infusion therapy. With special regard to total parenteral nutrition in preterm infants, sufficient glucose conversion to N-acetylneuraminic acid and other carbohydrate building blocks of glycoproteins and gangliosides is to be placed in question. This might have consequences for normal brain development and can be considered a challenge for future research work in this field.

Blood Glucose↗
PubMed1990

[Fecal sIgS and lysozyme excretion in breast feeding and formula feeding].

The bioavailability of sIgA and lysozyme from human milk was investigated in a total of 41 infants by radial immunodiffusion and by the Micrococcus lysodeicticus method, respectively. In four different pools of human milk used for balance studies the sIgA concentrations ranged between 2,200 and 17,850 mg/l. The lysozyme concentration varied from 64.5 to 283.5 mg/l. On human milk feeding the excretion of sIgA in 19 infants was 3,200 (0-8,200) mg per litre and 9.7 (0-131) mg lysozyme per litre, respectively. Corresponding values on formula feeding in 22 infants were 1030 (0-6400) and 2.6 (0-9) mg/l. Fecal sIgA excretion was significantly higher on human milk than on formula feeding. Balances of sIgA and lysozyme intake and excretion as performed in 9 infants revealed a less than 1% fecal excretion of both the protective substances. In vitro digestion of raw human milk with pepsin at pH 2 and 3 resulted in a rapid disappearance of immunologically reactive sIgA within 30 minutes after starting the incubation, while no changes in sIgA content were detectable at pH 4. Lysozyme proved to be resistant against peptic digestion. Tryptic digestion at pH 8 did not result in a decrease of human milk sIgA within 120 minutes of incubation at 37 degrees C while under analogous conditions lysozyme concentration approached to 0. These results point at the full bioavailability of both sIgA and lysozyme from human milk. The differing resistance of these protective substances against pepsin and trypsin is apparently adapted to physiological particularities of the digestive tract in early infancy.

Bottle Feeding↗
PubMed1989

[15N tracer kinetics of the utilization of yeast nitrogen].

The utilization of nitrogen from 15N-labeled Saccharomyces cerevisiae cells was studied in 6 infants by means of oral pulse labeling, comparing native and heat-treated yeast cells. The 15N dose used was 3 mg/kg. The body weight of the subjects varied between 5500 and 9400 g. The yeast cells were harvested from a culture medium which contained 15N ammonium chloride as the only source of nitrogen. The 15N-enrichment of the cells amounted to 95 atom-%. In the course of 48 h following the administration of the native yeast cells, 11% of the tracer dose were renally excreted. The corresponding value after labeling with heat-treated yeast cells was 17.9%. The cumulative renal excretion of the tracer tended to be faster as compared with pulse labeling of the native yeast cells. A paired comparison with labeled native and heated yeast cells in 3 subjects did not reveal any differences in the retention rate of 15N. When untreated 15N yeast cells were administered, 13.2% of the tracer dose were excreted in the urine and 10% respectively in the faeces. The retention was 76.8%. After single pulse labeling with 3 mg 15N/kg from heat-treated yeast cells the corresponding values were 19.4%, 4.4% and 76.2%, respectively. The kinetic of the renal 15N excretion points at the partial absorption of the yeast nitrogen from the colon.

Feces↗
PubMed1989

[Decreasing the immunogenicity of milk proteins by desialinization].

The immunogenicity of a native whey protein-casein mixture (relation 60:40) was compared with an analogous mixture which had been subjected to Warren's hydrolysis procedure for splitting off sialic acid. The immunization was performed in 3 rabbits each, with a mean body weight of 4,200 g. After parenteral administration of an antigen dose corresponding to 2 mg protein for 6 times, 10 ml blood were withdrawn from each of the animals on day 80 of the immunization procedure. The serum of those rabbits which had been injected the native whey protein-casein mixture was shown to precipitate this antigen intensively as could be demonstrated by Mancini's test. The cross reaction with the sialic acid-free protein mixture was strongly diminished. Immunization with sialic acid-free whey protein-casein failed to produce worth-while antibody formation against this antigen. Only a moderate cross reaction with native whey protein-casein was detectable. These results may have potential consequences for the production of infant formulas and dietaries.

Animals↗
PubMed1989

[The bifidogenic effect of breast milk. Theories and facts].

Human milk has the unique capability to originate and maintain a predominance of bifidobacteria in the large bowel of infants. There is evidence, that besides other protective factors this special microbiologic effect may have beneficial influences on the resistance against enteral infections as well as on a symbiotic utilization of some milk components. This is the reason, why there have been many attempts in past to imitate the bifidogenic effect in infant formulas. The different theories formed for the classification of this principle focus on either the low buffer capacity of mother's milk, the mutarotation of lactose and the existence of antimicrobial and bifidus growth factors, respectively. The bifidogenic principle is, however, in all probability not related to only one of these factors. It can rather be considered a complex of interacting factors, of which rapid gastric emptying due to the relatively high concentration of free amino acids and peptides, missing bacterial colonization of the small bowel, absence of antigenic effects of the food protein and low enterocyte regeneration may play an additional role. These aspects can be looked upon as a challenge for further research on mother's milk composition and on the metabolic effects of its constituents in future.

Bifidobacterium↗
PubMed1989

[Determination of protein nitrogen utilization with (15N) yeast protein in short bowel syndrome].

The digestive and absorptive capacity for food protein was studied in 8 infants with short bowel syndrome by means of [15N] yeast protein as a tracer substance. The extent of resection ranged from total removal of the small bowel to partial closures of the large bowel by colostomies. The tracer substance was administered as single oral pulse labeling in a dosage of 5 mg 15N/kg. The fecal losses of 15N were extremely high in cases of total and subtotal resection of the small bowel as well as after operative removal of the Bauhins valve. In the entirety they ranged between 3 and 95% of the intake. The corresponding 15N-retention in the protein pool was in the range between 0.1 and 91.6%. Operative findings, nutritional state and passage time were of limited value for the prediction of food protein assimilation. Even residual lengths of 25 cm of the small bowel turned out to be compensated, which was shown in one of the infants by an absorption of 97% and a retention rate of 84%. The oral [15N] yeast protein loading can be considered a reliable test for the evaluation of protein nitrogen absorption and utilization in short bowel syndromes.

Dietary Proteins↗
PubMed1987

[15N-tracer kinetic studies on the utilization of urea in protein metabolism of infants].

The virtual importance of the urea circuit is not clear. After a 3 to 21 day application of 100 mg [15N]-urea/l in 15 infants a [15N]-excess value of 0.06 in serum protein could be proven. Taking as a basis a protein content of 11.4% of the body mass and a regular distribution of the [15N] within the body one can calculate a retention of the urea nitrogen in the protein pool of 40.4% of the intake. Taking in account an amount of 11.4% urea nitrogen from the total nitrogen in mother's milk then the amount of urea nitrogen from the net protein accumulation comes to 6.5 (3.1-11.8)%.

Blood Proteins↗
PubMed1987

[In vitro studies on microbial incorporation of nitrogen from [15N2] urea and [15N]ammonium chloride by human intestinal flora].

6 typical bacteria species of the human intestinal flora (E. coli, Klebsiella pneumoniae, Proteus vulgaris, Streptococcus faecalis, Bacteroides fragilis, Bifidobacterium sp.) were incubated in a liquid medium for 48 h with [15N2]-urea and [15N]-ammonium chloride. The rates of [15N]-incorporation were calculated. They depend reproducible on the species examined, on the kind of the offered NPN-substance and on the amount of NPN-substance in the medium. With [15N2]-urea the minimal rate of incorporation was 3.8% (E coli) and the maximal one 95.6% (Bifidobacterium sp.). With [15N]-ammonium chloride the corresponding figures were 31.0 (Proteus vulg.) and 98.0% (Bifidobacterium sp.). The findings are discussed with regard to a possible enteral detoxification in uremic patients by bacterial utilization and elimination of urea and ammonia.

Ammonium Chloride↗
PubMed1987

Evidence for colonic absorption of protein nitrogen in infants.

The absorption of protein nitrogen by the colon was assessed in 6 infants with colostomy by giving 15N yeast protein in a dosage of 5-20 mg 15N/kg (92.4 atom-% 15N). The absorption of 15N ranged between 87.1 and 98.1% of the administered dose, and the retention in the protein pool ranged between 79.0 and 94.2%. The incorporation of 15N in the plasma proteins was demonstrated by 15N excess values between 0.02 and 0.10 atom-%. The results suggest that the colon can assimilate proteins when insufficient absorption of protein nitrogen in the small intestine occurs. The breakdown of protein is thought to result from the action of colonic flora.

Colon↗
PubMed1987

15N tracer techniques for the differential diagnosis of dwarfism and prediction of growth hormone action in children.

[15N]Glycine in a single oral dose was used to study nitrogen turnover in 18 short children, aged 3-14 yr. On the basis of their serum GH responses to insulin-induced hypoglycemia, the patients were divided into 3 groups: complete GH deficiency (GHD; n = 5); partial GH deficiency (pGHD; n = 6), and children with constitutional growth delay and familial short stature (CGD/FSS; n = 7). The mean 48-h renal excretion of 15N by patients with GHD was 66.09 +/- 14.12% (+/- SD) of the tracer dose. This decreased to 27.64 +/- 5.33% after two injections of 10 IU/m2 GH (P less than 0.001). 15N excretion by patients with pGHD was 47.19 +/- 13.42%, and it decreased after GH injection to 22.69 +/- 4.58% (P less than 0.005). Patients with CGD/FSS had 15N excretion of 37.27 +/- 5.68%, and it did not change in response to GH. The mean protein synthesis rate in GHD patients was extremely low, and it increased after GH injection from 0.99 +/- 0.46 to 3.53 +/- 0.43 g/kg X day. In pGHD patients the protein synthesis rate increased from 2.62 +/- 0.84 to 4.50 +/- 1.09 g/kg X day. The CGD/FSS patients had no change in protein synthesis rate after GH. Our results suggest that studies of the metabolism of [15N]glycine might be of value in predicting responsiveness to GH therapy.

Adolescent↗