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C Kunz

Publications and source records attributed to C Kunz.

At least 37 records · Page 2Linked to original sources
PubMed2001

The phenomenon of treatment failures in Human African Trypanosomiasis.

Treatment of Human African Trypanosomiasis (HAT or sleeping sickness) relies on a few drugs which are old, toxic and expensive. The most important drug for the treatment of second stage infection is melarsoprol. During the last 50 years treatment failures with melarsoprol were not a major problem in Trypanosoma brucei gambiense patients. Commonly a relapse rate of 5-8% was reported, but in recent years it has increased dramatically in some important foci of T. b. gambiense sleeping sickness. Treatment failures for T. b. rhodesiense are much less of a problem apart from some reports between 1960 and 1985 of refractoriness in T. b. rhodesiense patients in East Africa. Analysis of those isolates revealed that their in vitro sensitivity to melarsoprol was one-tenth that of sensitive isolates, and complete failure to cure the infection in the acute mouse model with melarsoprol levels comparable with those in human patients. There was very little indication of resistance in T. b. gambiense isolates from Côte d'Ivoire and NW Uganda. The in vitro melarsoprol sensitivities for populations from relapsing and from curable patients were in the same range. Melarsoprol concentrations in the plasma and cerebrospinal fluid of patients 24 h after treatment did not show any difference between patients who relapsed and those who could be cured. The reason for relapses in the recent T. b. gambiense epidemics are not known. Other parasite-related factors might be involved, e.g. affinity to extravascular sites other than the CNS which are less accessible to the drug. In conclusion, a combination of factors rather than a single one may be responsible for the phenomenon of melarsoprol treatment failures in T. b. gambiense patients.

Africa, Eastern↗
PubMed2000

Endotoxin-reduced milk oligosaccharide fractions suitable for cell biological studies.

Endotoxins (ET) are able to activate leukocytes and other cell types and thus affect cell adhesion studies with regard to biological functions of human milk oligosaccharides (HMO). In our HMO preparations we detected ET in concentrations of 1.1 to 32.7 ng/mg. However, as we found in previous tests, an ET concentration of less than 100 pg/ml was necessary in order to avoid effects on the expression of CD11b and CD62L on human neutrophil granulocytes. Therefore, we used affinity chromatography with a detoxifying gel (polymixin B) which reduces the ET concentration of 414.9 +/- 121.5 (mean +/- SEM) and 47.9 +/- 5.9 pg/mg for the acidic and the neutral HMO, respectively. As only about 50 - 100 microg HMO per ml test solution are usually used in biological assays, the residual ET concentration does not interfere with cellular functions. We conclude that despite structural similarities between ET as lipopolysaccharides and complex HMO, a one step purification of HMO preparations was sufficient to get HMO material that can be used in cell culture systems.

Chromatography, Affinity↗
PubMed2000

Immunomodulatory effects of breast milk oligosaccharides.

Breast milk oligosaccharides are excreted in urine in amounts that suggest that they may exist in the circulation at levels compatible with a physiological function. Some oligosaccharides have structural similarity to cellular adhesion molecules and may influence adhesion of cells in breast fed infants. In this study, breast milk oligosaccharides were purified and incubated in assays of cell adhesion. They were found to inhibit neutrophil adhesion to stimulated vascular endothelial cells in a dose dependent fashion. In contrast they enhanced platelet-neutrophil complex formation. These results indicate that breast milk oligosaccharides may play a physiological role in modulating cellular adhesion in vivo.

Absorption↗
PubMed2000

Expression of glucose transporters in lactating human mammary gland epithelial cells.

BACKGROUND: Human milk contains 60-80 g/l lactose and and oligosaccharides. To synthesize this large amount of carbohydrates, the lactating mammary gland has a high demand for precursor molecules. such as glucose and galactose. AIM OF THE STUDY: In the present study we investigated the molecular basis for the uptake of glucose and galactose into the human mammary gland. METHODS: Using RT-PCR, Southern and Western blotting we analyzed the expression of SGLT1 (sodium glucose cotransporter 1) und GLUT1 (sodium independent glucose transporter) in epithelial cells isolated from fresh human milk. RESULTS: Southern blot analysis of the amplicions revealed the expression of SGLT1 mRNA but not of GLUT1 mRNA in milk epithelial cells. Using Western blotting, SGLT1 protein was identified in human milk cells. CONCLUSIONS. Our findings indicate that 1) the cell fraction isolated from fresh human milk is a suitable model for investigating gene expression in the human mammary gland and 2) lactating human mammary gland epithelial cells are supplied with monosaccharides mainly via SGLT1.

Blotting, Southern↗
PubMed2000

[New possibilities for reconstructing extensive jaw defects with prefabricated microvascular fibula transplants and ITI implants].

The reconstruction of extensive jaw defects is frequently only possible with microvascular bone flaps. Here we are presenting an operative technique using prefabricated fibular flaps and osseointegrated implants. In a first operation, the fibula is prepared with implants, split skin graft, and a nonresorbable membrane. The jaw defect is reconstructed 6 weeks later and can be treated directly with a prosthesis thanks to osseointegrated implants. The technique is described with reference to 5 patients already operated according to this technique and the initial findings are evaluated.

Adult↗
PubMed2000

Human milk oligosaccharides are minimally digested in vitro.

In examining the functional aspects of human milk oligosaccharides (HMO), it is not known whether they are digested during the passage through the infant's gastrointestinal tract. HMO were prepared from individual milk samples (n = 6) and separated into neutral and acidic compounds by chromatography. These oligosaccharide fractions were studied for their digestibility by human salivary amylase, porcine pancreatic amylase and brush border membrane vesicles (BBMV) isolated from porcine small intestine; we also examined the effect of low pH on these structures. The characterization of HMO and their digestion products was performed by high-pH anion-exchange chromatography with pulsed amperometric detection (HPAEC-PAD) as well as TLC. It was shown that neither salivary amylase nor pancreatic amylase cleaved HMO. Only after a 2-h incubation with BBMV were slight modifications of the HMO observed. HPAEC-PAD analysis revealed two new components within the neutral oligosaccharide fractions; these were characterized by mass spectrometric analysis as lacto-N:-triose and galactose. Only lacto-N:-triose was present within digestion assays of oligosaccharides, which did not contain fucosyl or N:-acetylneuraminic acid residues. These results suggest that <5% of the HMO are digested in the intestinal tract. Hence, HMO may play a role as prebiotics or as factors influencing the local immune system of the intestine in breast-fed infants.

Amylases↗
PubMed2000

Manipulation of callus after linear distraction: a "lifeboat" or an alternative to multivectorial distraction osteogenesis of the mandible?

Despite impressive results, distraction osteogenesis of the mandible is still compromised by difficulties with vector control. Because of the action of the masticatory muscles, the gonion angle has the tendency to open, resulting in an open bite. We report two patients, aged 10 and 12 years, who developed a severe open bite during mandibular distraction. As a salvage procedure, manual shaping of the soft regenerate was done immediately after distraction. Uneventful bony consolidation was observed, which resulted in anatomically shaped gonion angles. The fact that a regenerate created by distraction osteogenesis can be molded to virtually any shape offers interesting perspectives for the correction of complex mandibular deformities.

Bony Callus↗
PubMed2000

Oligosaccharides in human milk: structural, functional, and metabolic aspects.

Research on human milk oligosaccharides (HMOs) has received much attention in recent years. However, it started about a century ago with the observation that oligosaccharides might be growth factors for a so-called bifidus flora in breast-fed infants and extends to the recent finding of cell adhesion molecules in human milk. The latter are involved in inflammatory events recognizing carbohydrate sequences that also can be found in human milk. The similarities between epithelial cell surface carbohydrates and oligosaccharides in human milk strengthen the idea that specific interactions of those oligosaccharides with pathogenic microorganisms do occur preventing the attachment of microbes to epithelial cells. HMOs may act as soluble receptors for different pathogens, thus increasing the resistance of breast-fed infants. However, we need to know more about the metabolism of oligosaccharides in the gastrointestinal tract. How far are oligosaccharides degraded by intestinal enzymes and does oligosaccharide processing (e.g. degradation, synthesis, and elongation of core structures) occur in intestinal epithelial cells? Further research on HMOs is certainly needed to increase our knowledge of infant nutrition as it is affected by complex oligosaccharides.

Bifidobacterium↗
PubMed1999

Distinct ethylene- and tissue-specific regulation of beta-1,3-glucanases and chitinases during pea seed germination.

The expression of beta-1,3-glucanase (betaGlu) and chitinase (Chn) was investigated in the testa, cotyledons, and embryonic axis of germinating Pisum sativum L. cv. 'Espresso generoso' seeds. High concentrations of betaGlu and Chn activity were found in the embryonic axis. Treatment with ethylene alone or in combination with the inhibitor of ethylene action 2,5-norbornadiene showed that an early, 4-fold induction of betaGlu activity in the embryonic axis during the first 20 h after the start of imbibition is ethylene-independent. This initial increase was followed by a later 4-fold ethylene-dependent induction in the embryonic axis starting at 50 h, which is after the onset of ethylene evolution and after completion of radicle emergence. The betaGlu activity in cotyledons increased gradually throughout germination and was ethylene-independent. In contrast, the ethylene-independent Chn activity increased slightly after the onset of radical emergence in the embryonic axis and remained at a constant low level in cotyledons. Immunoinactivation assays and immunoblot analyses suggest that early betaGlu activity in the embryonic axis is due to a 54-kDa antigen, whereas late induction is due to a 34.5-kDa antigen, which is likely to be the ethylene-inducible class I betaGlu G2 described for immature pea pods. Increases in Chn in the embryonic axis were correlated with a 26-kDa antigen, whereas amounts of the additional 32- and 20-kDa antigens remained roughly constant. Thus, ethylene-dependent and ethylene-independent pathways regulate betaGlu and Chn during pea seed germination. The pattern of regulation differs from that of leaves and immature pods, and from that described for germinating tobacco seeds. The functional significance of this regulation and its underlying mechanisms are discussed.

Journal Article↗
PubMed1999

[Early diagnosis of familial adenomatous polyposis based on multiple osteomas of the facial skull].

We describe a 21-year-old patient hospitalised because of a dislocated mandibular fracture and accidentally found to have multiple osteomas of the skull. A subsequent gastroenterological examination revealed the presence of multiple polyps in the large intestine, typical of familial adenomatous polyposis. A disease causing germline mutation in the adenomatous polyposis coli gene was identified by molecular genetic analysis. Although extracolonic features such as multiple osteomas, multiple epidermal cysts and desmoids are frequently found, most cases without a family history of familial adenomatous polyposis or colorectal cancer are only diagnosed because of colonic disease manifestations with colorectal cancer already present. This case report strikingly illustrates that in the absence of a family history the presence of extracolonic features allows presymptomatic diagnosis in familial adenomatous polyposis patients before colorectal cancer has developed.

Adenomatous Polyposis Coli↗
PubMed1999

Nephropathia epidemica and Puumala virus in Austria.

To study the epidemiology of hantavirus infections in Austria, 1215 humans and 596 rodents of different species were tested for the presence of antibodies against Puumala and Hantaan virus. Direct virus identification by polymerase chain reaction in lung tissue of serologically positive rodents was performed to verify antibody results and to determine the genetic identity of viral RNA by phylogenetic analysis of a part of the hantavirus M segment. For 32 of the 37 cases of nephropathia epidemica diagnosed in Austria, the location where transmission took place could be traced to specific areas in the Austrian federal states of Carinthia and Styria. The overall seroprevalence in humans was 1.2% and ranged from 0.02% in Villach, Carinthia, to 0.8% in Korneuburg, Lower Austria, and 1.8% in Wolfsberg, Carinthia. Virus RNA could be amplified from three Clethrionomys glareolus voles collected in Klippitztörl, Carinthia, and from one collected in Ernstbrunn, Lower Austria. The sequences were all identified as Puumala virus by phylogenetic analysis and were found to be most closely related to the western European Puumala viruses from Germany and France. No evidence of the existence of Hantaan-like infections and viruses in Austria was found.

Animals↗
PubMed1999

Lactose-derived oligosaccharides in the milk of elephants: comparison with human milk.

Human milk is commonly considered to be unique when compared with the milk of other species with regard to its high content of complex fucosylated and sialylated lactose-derived oligosaccharides. We describe the application of high-pH anion-exchange chromatography with pulsed amperometric detection and TLC to characterize and quantitate neutral and sialylated lactose-derived oligosaccharides in milk from three Asian elephants and human milk. The lactose contents of elephant and human milks were 25-30 g/l and about 66 g/l respectively, whereas total oligosaccharide concentration was about three times higher in elephant milk and comprised up to 40% (10% in human milk) of the carbohydrate content. The ratio neutral: acidic components was different in the milk of the two species; in elephant milk, the N-acetylneuraminic acid-containing oligosaccharides made up almost half of the total amount v. 30% in human milk. Most oligosaccharides in elephant milk were more fucosylated and/or sialylated compared with human milk components. By mild acid hydrolysis, fucose and N-acetylneuraminic acid were cleaved off from complex components, and this resulted in increased amounts of fucose, galactose, N-acetylneuraminic acid, lactose and lacto-N-neo-tetraose. Unique to elephant milk are the high levels of 3'-galactosyllactose (up to 4 g/l) and lacto-N-neo-tetraose which are present in human milk only in trace amounts. Elephant and human milks have high levels and unique patterns of oligosaccharides which may reflect the relative importance of these components in neonatal host defence, in endothelial leucocyte interactions or in brain development.

Animals↗
PubMed1999

Inflammation markers and cytokines in breast milk of atopic and nonatopic women.

BACKGROUND: Breast milk is thought to contain its own complex immune system. Whether or not this is altered in allergic individuals is not yet known. METHODS: By ELISA techniques, inflammatory markers (MIP-1alpha, sICAM-1) and T(H)1 (interferon-gamma [IFN-gamma]), as well as T(H)2 cytokines (interleukin [IL]-4, IL-10), were investigated in serum and milk samples from nonallergic (n = 23) lactating women and those with respiratory allergies (n = 19) during the first week postpartum. RESULTS: IFN-gamma was not detected in either serum or milk. IL-10 was more often found to be above the detection limit in both milk and serum samples from allergic mothers. IL-4 was detected in almost all serum samples with a wide variation. In milk, IL-4 was found in about 20% of the samples. MIP-1alpha was not detected in the serum but was detected in the milk of 23% of the nonatopic and 53% of the allergic mothers. Soluble ICAM-1 was present in all samples. Surprisingly, serum levels of sICAM-1 in allergic mothers (271+/-97 ng/ml) were significantly lower (P<0.001) than in nonatopic subjects (375+/-86 ng/ml). Concentrations of sICAM-1 in milk were similar in both groups. CONCLUSIONS: The concentrations of proinflammatory markers and cytokines in breast milk did not differ significantly between allergic and nonatopic mothers. In some individuals, high levels of MIP-1alpha, IL-10, and sICAM-1 could be found. However, the significance of these components for the breastfed infant is still unclear.

Adult↗
PubMed1999

Secretion of 13C-labelled oligosaccharides into human milk and infant's urine after an oral [13C]galactose load.

Human milk oligosaccharides seem to play an important role in the infant's defense against bacterial and viral infections of the gastrointestinal and the urogenital tract. In this study, we investigated the influence of dietary carbohydrates on the biosynthesis of lactose and oligosaccharides in the human mammary gland and their renal excretion by the human milk-fed infant. For this purpose, a lactating woman was given 27 g galactose (Gal) containing 2 g [13C] Gal (1-13C/99%) immediately after breakfast. In the following 36 h, milk (5-10 ml) was collected before each nursing. Infant's urine was collected over a period of 24 h. 13C-enrichment was measured in total milk, milk fat and protein, in the carbohydrate fraction as well as in urine by isotope ratio mass spectrometry (IRMS). Milk carbohydrates and deproteinized urine samples were fractionated by Sephadex G25 gel filtration and further analyzed by IRMS, high performance thin layer chromatography and and high pH anion exchange chromatography with pulsed amperometric detection (HPAEC-PAD). IRMS revealed that in milk a maximal delta 13CPDB was reached within 8 h after Gal intake which then rapidly declined in the following 8 h. The cumulative 13C-elimination over this first peak was 6.9% of the oral 13C-dose. The highest 13C-enrichment was detectable in the carbohydrate fraction, mainly in lactose and neutral oligosaccharides. Compared to the enrichment of human milk, the delta 13CPDB of infant's urine was delayed. In urine, the highest amount of 13C was found in the Sephadex G25 fractions which mainly contained lactose, fucosyl-lactose, lacto-N-tetraose (LNT), fucosyl-LNT and difucosyl-LNT. For further characterization, individual components were separated by HPAEC-PAD and subsequently analyzed by fast atom bombardment mass spectrometry and IRMS. The data show, that orally applied Gal is incorporated in milk, especially in lactose and neutral oligosaccharides. Obviously, some of these components were absorbed by the infant and then excreted with urine. There, oligosaccharides may serve as analogous receptors for bacterial or viral adhesion molecules, and, hence, may prevent urogenital infections in breastfed infants.

Administration, Oral↗
PubMed1999

S-fimbriae from Escherichia coli bind to soluble glycoproteins from human milk.

BACKGROUND: Escherichia coli (E. coli) strains, expressing S-fimbriae, belong to the most common gram-negative pathogens that cause sepsis and meningitis in neonates. The attachment of S-fimbriae to the cell surface is mediated by membrane glycoconjugates, which often carry N-acetylneuraminic acid. METHODS: Binding studies were performed with glycoproteins from the whey fraction of human milk to investigate whether they exert a potential inhibitory effect on bacterial adhesion. Whey glycoproteins were separated according to their molecular weight by fast protein liquid chromatography gel filtration. After sodium dodecyl sulfate-polyacrylamide gel electrophoresis, proteins were transferred to nitrocellulose membranes and incubated with isolated S-fimbriae from recombinant E. coli strain HB 101 (pANN 801-4). RESULTS: S-fimbriae recognized four whey proteins with a molecular mass of more than 200 kDa, 170 to 150 kDa, and 80 kDa. Their glycosylation pattern was investigated using the lectins Sambucus nigra, Maackia amurensis, Galanthus nivalis, and Arachis hypogaea. Thus the presence of N- and O-glycans in these proteins was confirmed. The preferential binding to N-acetylneuraminic acid containing glycoproteins was demonstrated by a complete abolishment of these reactions by incubation with acidic lactose-derived oligosaccharides. However, the cleavage of N-acetylneuraminic acid from glycoproteins by mild acid hydrolysis revealed a second binding site for S-fimbriae on milk proteins of a similar molecular weight range. Terminal galactose in human milk glycoconjugates were thought to react with S-fimbriae as well. CONCLUSION: These data further support the opinion that glycoproteins from human milk are potential receptor analogues for certain bacteria that may prevent microbial adhesion to the epithelial cell surface.

Animals↗
PubMed1999

Stochastic and nonstochastic post-transcriptional silencing of chitinase and beta-1,3-glucanase genes involves increased RNA turnover-possible role for ribosome-independent RNA degradation.

Stochastic and nonstochastic post-transcriptional gene silencing (PTGS) in Nicotiana sylvestris plants carrying tobacco class I chitinase (CHN) and beta-1,3-glucanase transgenes differs in incidence, stability, and pattern of expression. Measurements with inhibitors of RNA synthesis (cordycepin, actinomycin D, and alpha-amanitin) showed that both forms of PTGS are associated with increased sequence-specific degradation of transcripts, suggesting that increased RNA turnover may be a general feature of PTGS. The protein synthesis inhibitors cycloheximide and verrucarin A did not inhibit degradation of CHN RNA targeted for PTGS, confirming that PTGS-related RNA degradation does not depend on ongoing protein synthesis. Because verrucarin A, unlike cycloheximide, dissociates mRNA from ribosomes, our results also suggest that ribosome-associated RNA degradation pathways may not be involved in CHN PTGS.

Amanitins↗