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Biomedical subjects

E Holst

Publications and source records attributed to E Holst.

At least 73 records · Page 4Linked to original sources
PubMed1985

Propyl ether. I. Interaction with the sensory irritant receptor.

The sensory irritating response of propyl ether, measured as a decrease in respiratory rate in mice, faded within one minute. The threshold was 620 p.p.m., calculated from the concentration-response curve, which had a low slope. The sensory irritating level depressing the respiratory rate to 50 per cent (RD-50 = 89,000 p.p.m.) could not be reached with saturated vapour at 20 degrees. The thermodynamic activity corresponding to the RD-50 was about 0.6, a rather high value. The low slope and high thermodynamic activity may be explained by steric hindrance of the oxygen atom and thereby decreasing the receptor-activating capacity and/or the stability of the active receptor conformation. A specific effect beyond the receptor offers another explanation.

1-Propanol↗
PubMed1985

Propyl ether. II. Pulmonary irritation and anaesthesia.

After cessation of the sensory irritation response, described in part one (Nielsen et al. 1985), a mixed response due to pulmonary irritation and anaesthesia appeared, resulting a decrease in respiratory rate and tidal volume. The corresponding thresholds were 1490 p.p.m. and 1280 p.p.m., respectively, obtained from the last half hour of a four hours exposure period. As the decrease in respiratory rate and tidal volume was found to be correlated, the per cent decrease in respiratory minute volume could be approximated from the square of the respiratory frequency. A threshold limit value (TLV) about 100 p.p.m. based on pulmonary irritation and anaesthesia was proposed. No impurities in the technical grade ether influenced the responses.

Anesthesia↗
PubMed1985

Standardized intraabdominal abscess formation with generalized sepsis: pathophysiology in the rat.

Gelatine capsules containing Escherichia coli and Bacteroides fragilis in a standardized mixture with rat colonic content and barium sulfate were implanted intraabdominally into rats. Capsules of 0.75 g gave approximately 50% mortality whereas 0.35 and 1.10 g caused no or 100% mortality, respectively. In subsequent experiments, using the 0.75 g capsule, all animals became ill with signs of tachypnea, piloerection, low physical activity and hypersecretion of saliva 6-8 h after the implantation. The animals reduced their water and food intake substantially and the body weight decreased. A significant reduction in blood pressure, glucose and leukocyte and platelet counts was found 12 h after challenge. Blood cultures obtained at 12, 24, 48 and 60 h all grew E. coli but none B. fragilis. Succumbed animals revealed diffuse peritonitis with growth of E. coli and B. fragilis at autopsy, whereas surviving animals showed abscess formation at investigation on day 8 after challenge. It was concluded that the model closely resembled intraabdominal abscess formation with sepsis in man.

Abdomen↗
PubMed1984

Sensory irritation and pulmonary irritation by airborne allyl acetate, allyl alcohol, and allyl ether compared to acrolein.

The propene derivatives, allyl acetate, allyl alcohol, allyl ether, and acrolein were investigated for their property as sensory irritant in Ssc:CF-1 mice. The concentration of the chemicals necessary to depress the respiratory rate by 50% ( RD50 ) due to sensory irritation of the upper respiratory tract were 2.9, 3.9, 5.0 and 2.9 p.p.m., respectively. The potency of these propene derivatives varied very little for their concentration in air, in p.p.m., to depress the respiratory rate by 50%. However, when the potency is expressed in terms of thermodynamic activity acrolein was found to be 10 times more potent than the other propene derivates. This may be explained either by a higher reactivity of the carbon-carbon double bond or the involvement of the aldehyde group in a secondary chemical binding. No secondary chemical binding can be invoked for allyl acetate, allyl alcohol or allyl ether. In general, the chemical structure CH2 = CH-CH-O may be suspected to allow a molecule to act as a strong sensory irritant. The TLV's were predicted from the relation: TLV approximately equal to 0.03 X RD50 and were found to be 0.1, 0.1, 0.15, and 0.1 for allyl acetate, allyl alcohol, allyl ether, and acrolein, respectively. No pulmonary irritation was found at the concentration causing a 50% decrease in respiratory rate.

1-Propanol↗
PubMed1984

Vaginal colonization with Gardnerella vaginalis and anaerobic curved rods.

Ninety-four women colonized with anaerobic curved rods (CR) and/or Gardnerella vaginalis, were studied. Of these women, 34 were culture-positive for the long variant of CR. Eight of these latter women also harboured the short variant of these bacteria. In women colonized with CR, none had a predominance of lactobacilli in their vaginal flora, which was the case in 26 of the 60 women not harbouring CR. G. vaginalis was isolated from all 94 women. Mycoplasma hominis occurred significantly more often in women colonized with CR and G. vaginalis as compared with women not harbouring CR, but who were colonized with G. vaginalis (p less than 0.0005). The recovery rate of chlamydiae and gonococci was remarkably low, i.e. the organisms were isolated from one case each. Women colonized with CR complained of foul-smelling vaginal discharge significantly more often than women not found to harbour such organisms (p less than 0.001). In all women with CR, the number of leukocytes per high-power field of vaginal secretion exceeded that of 'clue cells'. Such cells were found in all patients with CR, but not in women with a lactobacilli-dominated flora, despite the fact that they all harboured G. vaginalis. Bacterial vaginosis might be due to a symbiotic infection with G. vaginalis and CR, possibly in conjunction with other anaerobes and/or M. hominis.

Adolescent↗
PubMed1984

The grivet monkey as a model for study of vaginitis. Challenge with anaerobic curved rods and Gardnerella vaginalis.

The grivet monkey was used as an experimental model for vaginitis. Gardnerella vaginalis was used for challenge in one monkey. G. vaginalis plus a long variant (LCR) of a hitherto unclassified anaerobic curved rod (CR) in another 2 monkeys, this LCR alone in 2, a short variant (SCR) of CR in 2, and G. vaginalis plus SCR in one monkey. All the bacterial strains had been isolated from human vaginal specimens. In the 2 monkeys exposed to G. vaginalis plus LCR, distinct signs of bacterial vaginosis characterized by a thin, grey and translucent discharge appeared after 5 days and were still present at the end of the 6-week observation period. LCR alone produced, if anything, a slight increase in the vaginal discharge after about 4-5 weeks. In the remaining monkeys there was no increase of vaginal secretion. The CR could still be isolated at the end of the observation period. LCR persisted for 9 months in one monkey, without having produced any obvious signs of vaginitis, which, however, did appear when the monkey was challenged with G. vaginalis too. G. vaginalis could be recovered up to 12 days after incubation in the monkeys also infected with CR, but at no time from the monkey challenged with G. vaginalis only. Bacteria of the G. vaginalis morphotype could be observed in Gram-stained vaginal smears collected throughout the observation period. Although having certain limitations, the model would seem to be of use for the study of bacterial vaginosis. Such a model in primates has not hitherto been available.

Animals↗
PubMed1984

Anaerobic curved rods in genital samples of women. Performance of different selective media, comparison of detection by microscopy and culture studies, and recovery from different sampling sites.

Anaerobic curved rods (CR) frequently occur in the vaginal flora of women with non-specific vaginitis, more recently referred to as bacterial vaginosis (BV). The reasons for difficulties in culturing CR include their anaerobic nature, slow rate of growth and presence in a highly mixed flora. The present study concerns the efficiency of three culture media--blood agar, a gonococcal medium, and Columbia agar--for recovery of CR. The possibility of improving selectivity by adding various antibiotics (e.g. nalidixic acid, colistin and tinidazole) to the media was also explored. The MICs for 157 CR strains and for 80 strains of anaerobic or facultatively anaerobic bacteria isolated from vaginal samples from women with BV were therefore determined. Columbia agar containing 1 micrograms/ml tinidazole in combination with either colistin (10 micrograms/ml) or nalidixic acid (15 micrograms/ml) proved the most efficient medium for recovery of CR. These antibiotic combinations effectively suppressed growth of Gardnerella vaginalis, anaerobic cocci and species of Bacteroides.--In 291 women, comparison was made of the detection of CR morphotype bacteria in methylene-blue-stained smears and the results of vaginal cultures for CR. A long variant (2-4 micron) was found in 42% by direct microscopy and 43% by culture. A short variant (approx 1 micron), which, with two exceptions, was always concomitant with the long variant, was demonstrable in only 3% of vaginal smears and in 14% of the cultures.--Vaginal samples were approximately four times more often culture-positive for CR than were cervical samples from the same women.

Bacteria, Anaerobic↗
PubMed1984

Recovery of anaerobic curved rods and Gardnerella vaginalis from the urethra of men, including male heterosexual consorts of female carriers.

Three hundred and nine men attending a clinic for sexually transmitted diseases were studied regarding urethral colonization with anaerobic curved rods (CR), Gardnerella vaginalis, Bacteroides ureolyticus, as well as for chlamydiae and gonococci. Ten (3.2%) of the men harboured CR. All strains of CR were of the short variant (approximately 1 micron long). Fourteen (4.5%) men were culture-positive for G. vaginalis and 58 (18.7%) for B. ureolyticus. Of the four men who were culture-positive for CR, but not for any other of the above-mentioned microbes, four had urethritis. From the 309 men, gonococci were isolated from 20 (6.4%) and chlamydiae from 96 (31.1%). Of the 10 men with CR, two concomitantly harboured Chlamydia trachomatis, four B. ureolyticus, and one G. vaginalis. The corresponding figures for those men with urethritis and who were colonized with G. vaginalis only were one of six, and for those carrying B. ureolyticus 14 of 37. None of 19 male consorts of the same number of women, harbouring the long variant (approximately 4 microns) of CR and G. vaginalis, were culture-positive for these two organisms.

Adolescent↗
PubMed1984

Subdivision of vaginal isolates of anaerobic curved bacteria based on genetic, morphologic, biochemical and gas-chromatographic/mass-spectrometric studies.

By DNA-DNA hybridization we could recognize two distinct groups of anaerobic curved rods (CR) that had been isolated from the vaginal content of women with bacterial vaginosis. On the basis of morphological studies these two groups correlated with one group of short, Gram-variable, curved rods (SCR) and another consisting of similar but somewhat longer rods (LCR). The SCR had up to four flagella per cell and the LCR up to eight. Among 79 biochemical tests, only tests for ONPG and arginine dehydrolase differentiated the two groups, SCR being positive and LCR negative. The gas chromatographic analysis of spent culture medium revealed that LCR, but not SCR, produced oxalacetic and oxalic acids. The groups were also differentiated by gas-chromatographic/mass-spectrometric patterns of certain cellular fatty aldehydes. Cell wall structure and presence of cytoplasmic inclusions did not distinguish SCR from LCR. On the basis of DNA-DNA hybridization values the SCR formed a more heterogeneous group than did LCR. Of all biochemical tests performed, only the production of alpha-galactosidase separated two strains of SCR that showed a low percentage of hybridization along with the rest of the SCR strains. Our study does not support a subdivision of SCR.

Aldehydes↗
PubMed1984

Gas chromatographic analysis of cellular fatty acids in anaerobic curved bacteria isolated from the vagina.

The fatty acid compositions of forty-five strains of anaerobic curved rods isolated from vaginal content were analysed by gas chromatography. Twenty-six of the strains were of a short Gram-variable type and 19 of a long Gram-negative type. The bacteria were subjected to alkaline saponification, after which the liberated fatty acids were methylated using boron trichloride-methanol. The samples were introduced onto a cross-linked (SE-54) fused silica capillary column. The major peaks in the chromatograms from all strains corresponded to C14:0, C16:0, C18:2, C18:1 and C18:0 fatty acids. Five additional components were seen, three of them identified by mass spectrometry as fatty aldehydes (saturated and unsaturated) of 16 to 18 carbon atoms, whereas the remaining two were not identified. The fatty aldehydes indicated the presence of plasmalogens in the bacterial strains studied. With two exceptions, all of the short rods were distinguishable from the long ones by the presence of one aldehyde and two unidentified compounds, all three eluting between C16:0 and C18:2.

Bacteria, Anaerobic↗
PubMed1984

Genetic relationships of short and long anaerobic curved rods isolated from the vagina.

DNA from anaerobic curved rods (CR) isolated from the human vagina were analysed regarding sequence homology and guanine + cytosine content. Of the strains of CR tested, ten belonged to the short (SCR) (approximately 1 micron) and eight to the long (LCR) (approximately 2-4 micron) CR type. A low level of homology (5-10%) was found between SCR and LCR. The LCR were a fairly homogeneous group of bacteria, with homologies ranging from 70 to 100%. The SCR fell into three DNA homology groups: one with 85%, and another with approximately 60% homology, while two strains belonging to the latter group hybridized with only 33%.

Bacteria, Anaerobic↗
PubMed1983

A study of operative treatment and bacteriological examination of persistent oro-antral fistulas.

A retrospective study of 35 patients with oro-antral fistulas of more than 2 weeks duration is presented. Treatment results by using the Rehrmann plastic procedure, as well as complications and sequelae are described. The results of bacteriological examination in 15 patients with maxillary sinusitis in association with oro-antral fistulas are presented. The bacteriological findings suggest that broad spectrum antibiotics in certain conditions should be administered in cases of persisting oro-antral fistulas associated with maxillary sinusitis. The results of the present study show that the Rehrmann-operation proves satisfactory even in treatment-resistent cases.

Adult↗
PubMed1983

Surgical management of 85 perforations to the maxillary sinus.

A study is presented of 85 cases of perforation to the maxillary sinus closed within 48 h after appearance. All cases were treated with the Rehrmann buccal flap procedure or primary suture. 1 patient developed an oro-antral fistula and sinusitis and a further 3 patients developed sinusitis postoperatively. A detailed presentation of the cases with complications is made. The relationship between a non-infectious sinus and the treatment results is discussed and the importance of antibiotic treatment in addition to surgical intervention is stressed.

Adolescent↗