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Biomedical subjects

R Nielsen

Publications and source records attributed to R Nielsen.

188 records · Page 11Linked to original sources
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Antibiotic prophylaxis in high risk biliary surgery: one dose of ceftriaxone compared with two doses of cefuroxime.

In a controlled trial 219 high risk patients undergoing biliary surgery were allocated at random by sealed envelopes to one of two treatment groups. Group I (n = 112) received a single dose ceftriaxone 1 g intravenously at the time of skin incision, and group II (n = 107) was given cefuroxime 1.5 g intravenously at the time of skin incision, followed by a second dose eight hours later. There were no significant differences between groups in age, sex, diagnosis, or operations carried out. There were three wound infections in group I (3%) and four in group II (4%) (p = 0.65). One patient in group I and two patients in group II developed intra-abdominal abscess and septicaemia (0.9% and 1.9%, respectively). Five patients developed pneumonia postoperatively in group I (5%) and six in group II (6%) (p = 0.65). There was no significant difference of the total number of postoperative infectious complications (wound infection, intraabdominal abscess, septicaemia, and pneumonia) between the groups (p = 0.42). A single dose of ceftriaxone given intravenously at skin incision was as effective as two doses of cefuroxime for the prophylaxis of wound infection in this high risk group of patients.

Abscess↗
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Haemophilus pleuropneumoniae (Actinobacillus pleuropneumoniae). Serotypes 8, 3 and 6. Serological response and cross immunity in pigs.

Immunity obtained by vaccination with Haemophilus pleuropneumoniae is type specific and protection will only be obtained against the serotype contained in the vaccine. Serotype 8 is closely related to serotypes 3 and 6 and the objective of the present study was therefore to examine if cross immunity between the three serotypes could be obtained at vaccination.

Animals↗
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Haemophilus pleuropneumoniae serotypes--cross protection experiments.

Pigs vaccinated with a killed 6-hour culture of Haemophilus pleuropneumoniae serotype 2 with Freund's incomplete adjuvant were not protected against challenge with serotypes 1, 5, 6 or 8. Equivalent results were obtained when pigs were vaccinated with serotypes 4 or 5 and challenged with serotype 2. In earlier studies of immunity induced by intranasal immunization with live H. pleuropneumoniae organisms, it was clearly shown that intranasal inoculation with one serotype of H. pleuropneumoniae would induce a strong immunity to both homologous and heterologous serotypes (Nielsen 1979). The present study has shown that cross immunity is not obtained with parenteral immunization. The results strongly suggest that the immune response of the pig to parenteral vaccination is different from the response seen after natural infection, and indicate that an important part of the defence mechanism against H. pleuropneumoniae infection is a local immune-barrier which is effective in preventing the bacterium from penetrating the mucosa. In earlier vaccination experiments 90 per cent of vaccinates were protected against homologous challenge (Nielsen 1976). In the present work a vaccine containing serotypes 1 through 6 was fully protective against serotypes 2 and 3 and also against serotype 8, which shares antigenic determinants with serotypes 3 and 6. These results indicate that the protection obtained by parenteral immunization is serotype-specific. Vaccines must therefore contain the serotypes existing in the swine population.

Animals↗
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Pleuropneumonia of swine caused by Haemophilus parahaemolyticus. Studies on the protection obtained by vaccination.

Sixty-six pigs were vaccinated with formaldehyde-killed 24-hour or 6-hour culture of H. parahaemolyticus with Freund's incomplete adjuvant (1:1 or 3:1) or 15 per cent Alhydrogel. The vaccine was injected subcutaneously when the pigs were 9 weeks old. A booster injection was given 2 weeks later. Two weeks after the booster injection the pigs were challenged by intranasal inoculation of 10(10) organisms. The efficacy of the vaccine was evaluated by clinical observations and autopsy findings. Vaccines with Alhydrogel adjuvant: With 24-hour culture 25 per cent of the pigs were protected. With 6-hour culture the protection reached 67 per cent. Vaccines with Freund's incomplete adjuvant: With 24-hour culture 67 per cent of the vaccinates were protected. With 6-hour culture 90 per cent were protected. It is concluded that a 6-hour culture of H. parahaemolyticus is superior to an older culture in immunizing power. Vaccine with Freund's incomplete adjuvant caused severe local reaction with persistent granuloma formation. For that reason it is questionable whether this vaccine will be accepted for field use. H. parahaemolyticus could be found in the respiratory tract, also of animals that were protected by vaccination. Further studies on the significance and duration of the carrier state in this infection are required.

Adjuvants, Immunologic↗
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Pleuropneumonia caused by Haemophilus parahaemolyticus. An attempt to control the disease at two progeny testing stations by serological blood testing followed by removal of the seropositive animals and their litter mates.

The complement fixation test was employed at two progeny testing stations in an attempt to avoid outbreaks of contagious pleuropneumonia, caused by Haemophilus parahaemolyticus. Pigs were isolated immediately after arrival at the testing stations and blood samples taken for serology. Test groups with seropositive animals were not admitted to the testing station. The sanitation scheme proved successful, in that acute outbreaks were avoided at both stations and the frequency of chronic pleuritis at slaughter fell from appr. 12 per cent to appr. 6 per cent (Station A) and from appr. 8 per cent to appr. 1 per cent (Station B). Accordingly, the complement fixation test may be of value in diagnosing subclinical infections and thus in the control of Haemophilus parahaemolyticus pleuropneumonia.

Animals↗