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M Pickel

Publications and source records attributed to M Pickel.

15 recordsLinked to original sources
PubMed2000

DNA vaccination prevents and/or delays carcinoma development of papillomavirus-induced skin papillomas on rabbits.

Malignant progression is a life-threatening consequence of human papillomavirus-associated lesions. In this study, we tested the efficacy of papillomavirus early-gene-based vaccines for prevention of carcinoma development of papillomavirus-induced skin papillomas on rabbits. Rabbit skin papillomas were initiated by infection with cottontail rabbit papillomavirus (CRPV). The papillomas were allowed to grow for 3 months without any treatment intervention. Rabbits were then immunized by gene gun-mediated intracutaneous administration of four DNA plasmids encoding CRPV E1, E2, E6, and E7 genes, respectively. All eight control rabbits receiving vector alone developed invasive carcinoma within 8 to 13 months. In contrast, only two of eight vaccinated rabbits developed carcinoma at 12 and 15 months, respectively. Papilloma growth was suppressed in the majority of vaccinated rabbits but not completely eradicated. These results indicate that gene gun-mediated immunization with papillomavirus early genes may be a promising strategy for prevention of malignant progression of human papillomavirus-associated lesions in humans.

Animals↗
PubMed1998

Different utilization of neutral lipids by Malassezia furfur and Malassezia sympodialis.

In recent years, the genus Malassezia has been expanded based on molecular data; in addition to M. furfur and M. pachydermatis, five new species (M. sympodialis, M. globosa, M. obtusa, M. restricta, M. slooffiae) have been described. Apart from their lipid dependence, little is known about the metabolism and nutritional requirements of these new species. Defined inocula of Malassezia reference strains were cultured on selective agar for pathogenic fungi which was overlaid with olive oil. Samples of the olive oil overlay were taken at regular intervals and the lipid fractions were analysed by high performance thin layer chromatography. Depending on the time of incubation and the number of cells, M. sympodialis and the other recently described species produced a significant increase in free fatty acids. In addition, a band of an apolar substance was identified as a mixture of fatty acid ethyl esters. While showing growth, strains of M. furfur produced only small amounts of ethyl esters and free fatty acids. The growth kinetics of M. furfur and M. sympodialis were also different: for M. sympodialis, a clear lag phase was observed, possibly indicating the necessity of extracellular hydrolysis of the triglycerides. The significance of the synthesis of ethyl esters could not be clarified. For routine differentiation, this metabolic difference is only of limited usefulness because slight contamination of M. furfur strains with other lipophilic Malassezia species may lead to misinterpretation due to the high metabolic activity. These metabolic differences might be important in the pathogenesis of Malassezia infections.

Agar↗
PubMed1997

Differentiation of Malassezia species: selectivity of cremophor EL, castor oil and ricinoleic acid for M. furfur.

In recent years, the genus Malassezia has been reclassified based on molecular data. In addition to M. furfur, M. pachydermatis and M. sympodialis, four new species, M. globosa, M. obtusa, M. restricta and M. slooffiiae, have been described. However, apart from their lipid dependence, little is known about the metabolism and nutritional requirements of all the seven species. Further to recent studies, 10 hydrophilic emulsifiers (HLB > 10) were examined in an agar diffusion test to determine their growth-promoting effect on reference strains of the different Malassezia species. Polyethylene glycol (PEG) 7 glyceryl monoalcanoate (Cetiol HE). PEG-glyceryl stearate (Tagat S2) and macrogol-50 stearate (Myrj 53) were metabolized by all strains, while PEG-35 castor oil (Cremophor EL) was metabolized only by M. furfur. The latter observation is due to a different metabolism of castor oil and its main component, ricinoleic acid (12-hydroxy oleic acid), which may also give an insight into the pathogenesis of diseases that are associated with Malassezia spp. As hydroxy fatty acids are important in maintaining the epidermal structure and function, their metabolism specifically by M. furfur might clarify some clinical aspects of pityriasis versicolor. Apart from this speculation, use of Cremophor EL, with splitting of esculin as an additional key character, improves the distinction of the species M. furfur, M. slooffiae and M. sympodialis.

Castor Oil↗
PubMed1997

Polidocanol sensitivity--a possible tool in the differentiation of Malassezia spp.

In recent years, the genus Malassezia was reclassified based on molecular data; in addition to M. furfur, M. pachydermatis and M. sympodialis, four new species (M. globosa, M. obtusa, M. restricta, M. slooffiae) were described. Primary keys for routine identification have recently been presented. Polidocanol was shown to have specific inhibitory effects against Malassezia spp. In an agar diffusion test, type strains of all Malassezia species were incubated with polidocanol concentrations between 0.01% and 10%. M. furfur strains were most resistant, with minimal inhibitory concentrations (MIC) ranging from 7.5% to 10%. Inhibitory concentrations of the other strains were lower by at least one factor of ten. Most sensitive were strains of M. pachydermatis (0.05%). In a further test, polidocanol-containing olive oil was used to determine the sensitivity of Malassezia furfur and M. sympodialis. Again, the inhibitory concentrations for strains of M. sympodialis were one tenth of those found for M. furfur. In addition to its antifungal effects, polidocanol might therefore be a useful tool in differentiating Malassezia species.

Agar↗
PubMed1996

Ultrastructure of pre- and postcolostral enterocytes of the newborn calf.

Ten calves were used to elucidate the ultrastructure of enterocytes before and 24 h after colostral intake. Tissue samples were obtained from duodenum, jejunum (5 locations) and ileum. Protein A-gold technique was applied to immunoelectron-microscopically demonstrate colostral IgA. The prominent feature of the precolostral enterocytes are intracytoplasmic vacuoles. The frequency of vacuoles increases from cranial jejunum to ileum and from the villi bases to the tips. The appearance of absorptive vacuoles after colostral administration correlates with the incidence of precolostral empty vacuoles. Bovine IgA was detected in absorptive vacuoles and within the intestinal lumen of postcolostral calves. In addition to a diffuse IgA labelling of most vacuoles, a few corresponding enterocytic vacuoles labelled inhomogenously or negatively. This study demonstrates morphologically that the main site of colostral absorption is the middle-to-caudal region of the small intestine. Immunoelectron microscopy of IgA labelling provides indications of a selective IgA absorption in addition to pinocytosis.

Animals↗
PubMed1994

An immunoelectron microscopic investigation of colostral IgG absorption across the intestine of newborn calves.

The protein A-gold was used to examine the transport of colostral IgG from the lumen of the gut to the circulation in four newborn calves and one 24-hour-old calf. The absorptive enterocytes of the duodenum, jejunum and ileum were investigated five to 60 minutes after administering colostrum, and 24 hours after birth. In the newborn calves, an intracellular micropinocytotic transport of IgG molecules was dominant throughout the entire small intestine. The amount transported increased from the duodenum to the ileum. In addition, evidence of a selective, receptor-mediated transport of IgG during the first few hours of life was provided by the presence of bovine clathrin at the microvillous membrane of the duodenal and jejunal enterocytes, indicating the existence of specialised vesicles for transport, the so-called 'coated' vesicles. No sign of paracellular transport was detected. Intestinal closure was interpreted as a multifactorial event comprising the replacement of the fetal intestinal epithelial cells by more mature populations, the initial cessation of transport at the basal and lateral cell membrane of the absorptive enterocytes, and an increase in intracellular proteolytic activity by lysosomes.

Animals↗
PubMed1990

[Uterine perforation following an experiment in the correction of a uterine torsion in the 5th month of pregnancy. Illustrated report].

In this case report a perforation of the uterus in a German Black Pied cow after correction of the uterine torsion in the 5th month of gestation is described. Because of the hopeless prognosis, the cow was slaughtered. An additional finding was a metaplastic keratinization of the chorionic epithelium in the form of a plaque. The reason and pathogenic meaning of this metaplasia is not known. In the discussion, therapy of the uterine torsion in such an early state of gestation is critically considered.

Animals↗
PubMed1989

Investigations on the influence of copper succinate on the production of superoxide anion radicals by bovine small intestinal mucosa cells.

The effect of an experimental ischemia lasting for 45 minutes and a subsequent period of reperfusion of equal length on the activity of xanthine oxidase (XO) and microsomal NADPH-cytochrome P450 reductase (NADPH-CR) were investigated in the small intestinal mucosa of male neonatal calves of the breed German "Schwarzbunte". The activity of the NADPH-CR was determined by chemiluminescence. The activity of XO decreased during ischemia, but rose to values above the control level following reperfusion. 5 mg of Cu2(succinate)2 (CuSu) administered either intraarterially or intraluminally during reperfusion prevented the rise in XO. Formation of malondialdehyde decreased in the presence of CuSu. The NADPH-CR likewise showed subnormal activity values during ischemia, but also remained at a low level during reperfusion. The activity of this enzyme was further lowered by local intraarterial or intraluminal administration of 5 mg of CuSu and by 120 mg of CuSu administered intravenously during the reperfusion. These results are discussed with regard to the superoxide anion radical induced tissue lesions observed during reperfusion.

Animals↗
PubMed1989

[Creatinine, urea and mineral levels during the first week of life in healthy premature calves and calves with a delayed asphyxia syndrome].

The physical condition of 44 calves delivered by caesarean section before term was monitored by clinical and repeated laboratory examinations (analysis of creatinine, urea, sodium, potassium, chloride, and inorganic phosphorus) during the first seven days of life. The newborns were divided into two groups based on the clinical observations during the first hour of life, the blood pH and the base deficit: Group 1: 30 calves without respiratory distress syndrome (vital, non asphyxial); they did not develop any diseases in the course of the experiment. Group 2: 14 calves with respiratory distress syndrome (asphyxial); 9 of these animals died in the course of the experiment. The analysis of the parameters creatinine, urea, sodium, potassium, chloride, and inorganic phosphorus did not reveal any disturbance in kidney function in vital or in asphyxial prematurely born calves. All findings corresponded to those in calves born at term. So these parameters are not very meaningful in relation to metabolic disorders in respiratory distress syndrome.

Animals↗
PubMed1989

[Comparison of arterial and venous blood gas and acid-base values in prematurely born healthy calves or calves with a late asphyxia].

The arterial and venous blood gas and acid-base values of 44 calves delivered by caesarean section before term were examined during the first seven days of life. The newborns were divided into two groups based on clinical observations during the first hour of life, the blood pH and the base deficit: Group 1: 30 calves without respiratory distress syndrome (vital, non-asphyxial); they did not develop any diseases in the course of the experiment. Group 2: 14 calves with respiratory distress syndrome (asphyxial); 9 of these animals died in the course of the experiment. The blood gas and acid-base parameters (blood pH, base deficit, pCO2, pO2) measured in venous blood of the calves without respiratory distress syndrome (group 1) were similar to those cited in the literature for calves delivered at term. Among the calves that had survived respiratory distress syndrome, significantly decreased blood pH and increased base deficit values were found in both venous and arterial blood even on the third day after birth. Differences in pCO2 and pO2 were, however, no longer statistically significant between the two groups after 24 hours of life. For blood pH, base deficit, and pCO2 significant correlations were consistently found between the values in venous blood and the corresponding values in arterial blood in vital (non-asphyxial) calves. Due to the considerably smaller number of animals significant correlations between these parameters were less frequent in asphyxial calves, although some of the correlation coefficients were higher than in the vital calves. Experimentally induced influences and animal variation made the corresponding pO2-values of venous and arterial blood in both test groups less unequivocal. The analysis of arterial blood gas and acid-base parameters was not more conclusive than the analysis of venous blood regarding diagnosis and prognosis of respiratory distress syndrome. The blood pH and base deficit seemed to be the most suitable parameters to evaluate the severeness of the disease.

Acid-Base Equilibrium↗
PubMed1989

[AST, GLDH, gamma-GT, total bilirubin and CK values during the first week of life in healthy premature calves or calves with a late asphyxia syndrome].

The physical condition of 44 calves delivered by caesarean section before term was monitored by clinical and repeated laboratory examinations (analysis of AST, GLDH, gamma-GT, CPK, total bilirubin) during the first seven days of life. The newborns were divided into two groups based on the clinical observations during the first hour of life, the blood pH and the base deficit: Group 1: 30 calves without respiratory distress syndrome (vital, non asphyxial); they did not develop any diseases in the course of the experiment. Group 2: 14 calves with respiratory distress syndrome (asphyxial; 9 of these animals died in the course of the experiment. No significant differences between the vital and asphyxial calves were found in respect to the enzymes AST, GLDH, gamma-GT, CK as well as total bilirubin values measured during the first week of life. These blood parameters were within the normal range for calves delivered at term. The results do not indicate any disorder in liver and muscle functions in prematurely born calves with or without respiratory distress syndrome.

Animals↗
PubMedDate not supplied

Caring for families: what we see is what they get.

Working with families of preterm infants challenges the ability of professionals to address several issues and to provide continuity of care. A clinical example is used to illustrate why important data fail to be assessed and communicated and how this compromises care.

Aftercare↗