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Biomedical subjects

R Nielsen

Publications and source records attributed to R Nielsen.

At least 91 records · Page 5Linked to original sources
PubMed1993

Antibodies against Actinobacillus pleuropneumoniae serotype 2 in mucosal secretions and sera of infected pigs as demonstrated by an enzyme-linked immunosorbent assay.

Mucosal and serum antibodies against Actinobacillus pleuropneumoniae serotype 2 were demonstrable in an ELISA which used whole bacterial cells as antigen. Following experimental infection of pigs with A pleuropneumoniae serotype 2, specific antibodies against the bacteria were demonstrated in saliva and fluid obtained by bronchoalveolar lavage. There was a good correlation between the IgA antibody titre in this fluid and serum. As a result of natural infection, IgA antibodies were also demonstrable in the saliva at an early stage of infection when no serum antibodies were detectable. Later in the infection, when antibodies were present in the serum, salivary IgA antibodies were undetectable. The data suggest that the mucosal IgA antibody response arises before the systemic response. Measuring mucosal antibodies in saliva or nasal or bronchoalveolar fluid might therefore open the possibility of identifying pigs infected with A pleuropneumoniae at an early stage of infection.

Actinobacillus Infections↗
PubMed1993

Protective immunity following immunisation of pigs with aerosol of Actinobacillus pleuropneumoniae serotype 2.

To introduce antigen to the respiratory mucosa, killed Actinobacillus pleuropneumoniae with quil A as adjuvant was administered to pigs as an aerosol. Immunisation by this aerosol induced a marked IgA response in the bronchoalveolar and nasal fluids, and in the serum. Following challenge with live bacteria two weeks after the last exposure to the aerosol, the immunised pigs were protected from the severe pleuropneumonia which developed in non-immunised pigs. The immunised pigs had lower antibody titres in the mucosal fluids and serum after exposure to the challenge. The immune response after experimental infection of non-immunised animals was a weak IgA antibody response in the bronchoalveolar and nasal fluids, whereas the systemic immune response after challenge included both IgA and IgG antibodies.

Actinobacillus Infections↗
PubMed1993

Blocking enzyme-linked immunosorbent assay for detection of antibodies against Actinobacillus pleuropneumoniae serotype 8.

A blocking enzyme-linked immunosorbent assay (ELISA) for detection of antibodies against Actinobacillus pleuropneumoniae serotype 8 is described. The test is based upon a competitive reaction between the serum to be tested and a polyclonal rabbit antiserum prepared against serotype 8 and absorbed with whole cells of serotypes 3 and 6. The blocking ELISA proved able to distinguish animals infected with serotype 8 from those infected with any other serotype of A. pleuropneumoniae including the antigenically closely related serotypes 3 and 6. Positive results were not observed with field sera from serotype 6 infected herds or from herds known to be free from A. pleuropneumoniae infection.

Actinobacillus Infections↗
PubMed1993

Pathogenicity and immunity studies of Haemophilus parasuis serotypes.

After intranasal inoculation of SPF pigs with the 7 reference strains of Haemophilus parasuis only the reference strains of serotypes 1 and 5 proved to be pathogenic and were able to produce the lesions characteristic of Glässer's disease. Even though the reference strains of serotypes 2, 3, 4, 6 and 7 proved to be apathogenic, intranasal inoculation resulted in the development of circulating antibodies as demonstrated by the complement fixation test. This serological response suggests an antigenic relationship between serotypes 1 and 3 different from the relationship seen among serotypes 2, 4, 5, 6 and 7. Pigs given an aerosol with the apathogenic serotypes 2, 3, 4 and 7, respectively, resisted challenge with a virulent Danish strain of serotype 5. These results indicate that the 7 serotypes also have antigenic determinants in common and that these determinants elicit cross-protecting immunity on the respiratory mucosa.

Animals↗
PubMed1992

Papaverine reduces the sodium permeability of the apical membrane and the potassium permeability of the basolateral membrane in isolated frog skin.

The effect of papaverine, an inhibitor of the phosphodiesterase responsible for breakdown of cAMP, on the transepithelial sodium transport across the isolated frog skin was investigated. Serosal addition of papaverine caused initially an increase in the short-circuit current (SCC), a doubling of the cellular cAMP content and a depolarization of the intracellular potential under SCC conditions (Vscc). The initial increase in the SCC was followed by a pronounced decrease both in the SCC and in the natriferic action of antidiuretic hormone (ADH), but papaverine had no inhibitory effect on the ability of ADH to increase the cellular cAMP content. As SCC declines, no hyperpolarization was observed. The I/V relationship across the apical membrane during the inhibitory phase, revealed that papaverine reduces the sodium permeability of the apical membrane (PNaa) as well as intracellular sodium concentration. These observations and the previously noted effect of papaverine on Vscc indicates that papaverine must have an effect on the cellular Cl or K permeability. The basolateral Na,K,2Cl cotransporter was blocked with bumetanide, which should bring the cellular chloride in equilibrium. Bumetanide had no effect on basal SCC and Vscc. When papaverine was added to skins preincubated with bumetanide, the effect of papaverine on SCC and Vscc was unchanged. Therefore, the depolarization of Vscc, observed during the papaverine-induced inhibition of the SCC, must be due to a reduction in the cellular K permeability. In conclusion, it is suggested that papaverine reduces the sodium permeability of the apical membrane and the potassium permeability of the basolateral membrane of the frog skin epithelium.

Animals↗
PubMed1992

Localized temperatures and water vapour pressures within clothing during alternate exercise/rest in the cold.

The purpose of this study was to determine the variation of localized skin temperatures, clothing surface temperatures and water vapour pressures within a clothing system when worn during alternating work/rest cycles in a cold environment. A two-layer prototype clothing system comprising underwear and a uniform was studied on eight subjects (Ta = Tr = 5 degrees C; Tdp = -3.5 degrees C; va = 0.32 m s-1; Itot = 0.24 m2 K W-1). The 2 h experiment comprised a twice-repeated bout of 40 min cycle exercise (W = 56 W m-2; M = 313 W m-2) followed by 20 min of rest (M = 62 W m-2). Esophageal, skin, clothing, and ambient temperatures, as well as dew-point temperatures near the skin, in the clothing and in the environment were monitored. In addition, evaporation of sweat and sweat accumulated in the clothing were determined. The temperatures and water vapour pressures in all clothing layers varied significantly with the human thermoregulatory responses (skin temperature, sweating) to alternating work/rest cycles. Different courses of localized corresponding temperatures and water vapour pressures indicated that various forms of heat transport and heat exchange in the skin-clothing-environment system are of significance in different body areas.

Adult↗
PubMed1992

Clonal analysis of the Actinobacillus pleuropneumoniae population in a geographically restricted area by multilocus enzyme electrophoresis.

The genetic diversity among 250 isolates of Actinobacillus pleuropneumoniae from lungs of pigs with pleuropneumonia and from tonsils of apparently healthy pigs at slaughter was estimated by multilocus enzyme electrophoresis. The Danish strains were derived from both specific-pathogen-free and conventional herds. Sixty-six percent of the isolates belonged to three electrophoretic types (ETs) of a total of 37 ETs detected. While five biotype 2 isolates constituted a separate ET closely related to biotype 1 isolates, the type strain of the species (Shope 4074) belonged to its own ET, with a genetic distance of 0.30 from its nearest neighbor. Isolates of serotypes traditionally considered to have less pathogenic potential (serotypes 6, 10, and 12) from herds with acute outbreaks of pleuropneumonia belonged to the same ETs as isolates from apparently healthy pigs, suggesting that factors such as cross immunity and management may lead to divergent clinical results. Isolates from four herds harboring more than one serotype showed distinct profiles between the serotypes, indicating no or only limited chromosomal recombination among clones. Isolates from tonsils belonged to the same ET as isolates from lungs. The same ET was isolated from widely different parts of the world. Evidence from this study indicates that multilocus enzyme electrophoresis may be a valuable tool for the epidemiological analysis of A. pleuropneumoniae.

Actinobacillus pleuropneumoniae↗
PubMed1991

Thermoregulatory and subjective responses of clothed men in the cold during continuous and intermittent exercise.

Thermoregulatory and thermal subjective responses were studied in ten male, clothed subjects during continuous (C) and intermittent (I) exercise at the same average level of oxygen consumption. The subjects performed both I and C twice, dressed in two different three-layer cold-protective clothing ensembles of two thermal insulation levels [total clothing insulation = 2.59 clo (L) and 3.20 clo (H)]. Experiments were carried out at an ambient temperature of -10 degrees C. Rectal temperatures increased similarly in both types of exercise. Mean skin temperature (Tsk) was lower in I compared to C with both levels of clothing insulation. Over the last 0.5 h of the experiment Tsk was approximately 1.3 degrees C lower in I than in C for clothing L. The skin evaporation rate was higher in clothing H than L but did not differ between I and C. Subjective ratings for thermal sensations of the whole body (BTS) and hands were close to neutral in I and around slightly warm in C. The BTS was lower in I than in C and was lower in L compared to H. It was concluded that, at equal average energy expenditure, thermal responses to intermittent and continuous exercise in the cold differ in clothed subjects, principally as a result of different patterns of heat exchange.

Adult↗
PubMed1991

Blocking enzyme-linked immunosorbent assay for detection of antibodies to Actinobacillus pleuropneumoniae serotype 2.

A blocking enzyme-linked immunosorbent assay (ELISA), based upon a polyclonal rabbit antiserum specific to Actinobacillus pleuropneumoniae serotype 2, was developed for the detection of antibodies to A. pleuropneumoniae serotype 2 in pigs. By testing sera from pigs experimentally infected with the 11 recognized serotypes of A. pleuropneumoniae, the assay was proven to be specific for A. pleuropneumoniae serotype 2. With field sera from herds infected with A. pleuropneumoniae serotype 2, the assay was found to be more sensitive than the complement fixation test. Positive results were not observed with field sera from herds known to be free from Actinobacillus infection or with sera from two herds infected with either A. pleuropneumoniae serotype 6 or 8. The high diagnostic sensitivity and specificity of the blocking ELISA will make it useful in field diagnostic work.

Actinobacillus↗
PubMed1991

Contaminated fistula following J-pouch ileoanal reservoir. Treatment with a collagen sponge containing gentamicin and metronidazole. Case report.

In a 55-year-old woman, a 1 x 5 cm fistula developed in the ileoanal anastomosis after restorative proctocolectomy with J-pouch ileoanal reservoir and temporary ileostomy for intractable ulcerative colitis. The fistula extended between the pouch and the sacral bone. Lasting closure was achieved by intrafistular placement of a collagen sponge containing gentamicin and soaked in metronidazole solution and pouch drainage through a transanal Foley catheter.

Anal Canal↗
PubMed1990

[Information to women applying for sterilization].

On the basis of a questionnaire investigation among the general practitioners in the County of Frederiksborg, the authors have compared the information given to women applying for sterilization with information in the available literature about the nature of the intervention, its sequelae and the risks involved. The authors found that under half of the practitioners gave informations about disturbances of menstruation, dyspareunia and altered sexual life. In the literature, it is stated that these occur in 10-60%, 3-11% and 4-48% of the women. Less than one third of the practitioners gave information about the risk of perforation of an organ or vessels, tearing of the ovarian tubes and postoperative pain. In the literature, it is stated that these occur in 0.1-2.5%, 0.28-9% and 24% of the women depending on the operative method used. The authors recommend revision of our knowledge on these subjects and alterations in the written information provided.

Denmark↗
PubMed1990

[Unwanted pregnancy after removal of the IUD].

Four cases of unwanted pregnancy occurring in the same cycle as removal of an IUD are presented. The duration of ovum transport from the Fallopian tube into the uterine cavity, survival of spermatozoa in the female genital tract and timing of ovulation, which may be delayed in women with IUDs are variables which influence the probability of pregnancy and should be taken into consideration when removing an IUD. Unless pregnancy is desired, it is recommended when possible not to remove an IUD after the ninth day of the menstrual cycle unless another contraceptive method has been initiated.

Adult↗
PubMed1990

[Lack of precision of measurements with neonatal thermometers].

Seventy Uebe's mercury neonatal thermometers were checked in a thermostatically-controlled water bath to detect possible errors in measurement. Sixteen out of 18 old neonatal thermometers showed gross errors of measurement with a maximal deviation of +5.31 degrees C. Out of 52 recently issued neonatal thermometers, only 27 (52%) fulfilled the requirements for correction of maximally 0.10 degree C established by the Danish Ministry of Health. The remaining 25 neonatal thermometers presented lesser errors with a maximal deviation of -0.30 degrees C. Employment of Uebe's mercury neonatal thermometer can thus only be recommended after meticulous testing of the thermometers prior to use and with continued regular control of the accuracy of temperature measurements.

Diagnostic Errors↗
PubMed1990

Thermoregulatory responses to intermittent exercise are influenced by knit structure of underwear.

The purpose of this study was to evaluate the role of knit structure in underwear on thermoregulatory responses. Underwear manufactured from 100% polypropylene fibres in five different knit structures (1-by-1 rib, fleece, fishnet, interlock, double-layer rib) was evaluated. All five underwear prototypes were tested as part of a prototype clothing system. Measured on a thermal manikin these clothing systems had total thermal resistances of 0.243, 0.268, 0.256, 0.248 and 0.250 m2.K.W-1, respectively (including a value for the thermal resistance of the ambient environment of 0.104 m2.K.W-1). Human testing was done on eight male subjects and took place at ambient temperature (Ta) = 5 degrees C, dew point temperature (Tdp) = -3.5 degrees C and air velocity (Va) = 0.32 m.s-1. The test comprised a repeated bout of 40-min cycle exercise (315 W.m-2; 52%, SD 4.9% maximal oxygen uptake) followed by 20 min of rest (62 W.m-2). The oxygen uptake, heart rate, oesophageal temperature, skin temperature, Ta, Tdp at the skin and in the ambient air, onset of sweating, evaporation rate, non-evaporated sweat accumulated in the clothing and total evaporative loss of mass were measured. Skin wettedness was calculated. The differences in knit structure of the underwear in the clothing systems resulted in significant differences in mean skin temperature, local and average skin wettedness, non-evaporated and evaporated sweat during the course of the intermittent exercise test. No differences were observed over this period in the core temperature measurements.

Adult↗
PubMed1990

Prostaglandin E2 enhances the sodium conductance of exocrine glands in isolated frog skin (Rana esculenta).

Prostaglandins are known to stimulate the active transepithelial Na+ uptake and the active secretion of Cl- from the glands of isolated frog skin. In the present work the effect of prostaglandin E2 (PGE2) on the glandular Na+ conductance was examined. In order to avoid interference from the Na+ uptake and the glandular Cl- secretion the experiments were carried out on skins where the Cl- secretion was inhibited (the skins were bathed in Cl- Ringer's solution in the presence of furosemide, or in NO3- Ringer's solution), and the active Na+ uptake was blocked by the addition of amiloride. Transepithelial current, water flow and ion fluxes were measured. A negative current was passed across the skins (the skins were clamped at -100 mV, basolateral solution was taken as reference). When PGE2 was added to the skins under these experimental conditions, the current became more negative; this was mainly due to an increase in the Na+ efflux. Together with the increase in Na+ efflux a significant increase of the water secretion was observed. The water secretion was coupled to the efflux of Na+, and when one Na+ was pulled from the basolateral to the apical solution via this pathway 230 molecules of water followed. From the data presented it is suggested that this pathway for Na+ is confined to the exocrine glands.

Amiloride↗
PubMed1990

Role of Ca2+ and prostaglandin in regulation of active Na+ transport in frog skin.

1. The role of prostaglandins and intracellular Ca2+ in regulation of active transepithelial sodium transport in frog skin were studied by examinations of effects of the calcium ionophore A23187 on short-circuit current (SCC) and intracellular voltage. 2. A23187 and arachidonic acid induced a marked increase in both SCC and prostaglandin E2 synthesis. 3. In indomethacin treated skins A23187 did not stimulate but on the contrary inhibited the basal SCC. 4. The A23187-induced increase in SCC was associated with a decrease in the fractional resistance of the apical membrane and a depolarization of the cells. 5. In skins pretreated with indomethacin, the A23187 induced inhibition of SCC coincided with a slight hyperpolarization of the cellular potential and an increase in fractional resistance of the apical membrane.

Animals↗