Prophylactic ephedrine attenuates the hemodynamic response to propofol in elderly female patients

In this study, we compared the effect of prophylactic administration of ephedrine against the hypotensive effect of propofol in elderly female patients scheduled for minor gynecological procedures. Ninety patients aged 60 yr or older were randomly allocated to one of three groups of 30 patients each to receive either normal saline, ephedrine 0.1 mg/kg, or ephedrine 0.2 mg/kg i.v. 1 min before the induction of anesthesia. Anesthesia was induced and maintained with propofol and fentanyl. Hemodynamic variables were measured before and 2, 5, 10, 15, 30, and 60 min after induction. The decrease in blood pressure and heart rate (HR) was significantly less in each of the ephedrine groups (P < 0.001). Furthermore, the decrease was less in the large-dose group compared with the small-dose group (P < 0.05). Twelve patients in the control group experienced a decrease in systolic blood pressure to < 80 mmHg, compared with only one patient in the ephedrine groups (P < 0.001). In conclusion, the prophylactic injection of ephedrine significantly attenuated, but did not completely abolish, the decrease in blood pressure associated with induction of anesthesia with fentanyl and propofol. Ephedrine 0.2 mg/kg was slightly more effective than ephedrine 0.1 mg/kg.

IMPLICATIONS

The prophylactic effect of ephedrine to counteract the hypotensive effect of propofol induction of anesthesia was investigated in three groups of elderly female patients given 0.1 or 0.2 mg of ephedrine or placebo before induction. Both ephedrine doses markedly attenuated, but neither of them abolished, the decrease in blood pressure.

Calibration of Abbott AxSYM Ferritin kit using the WHO Human Liver Ferritin International Standard 80/602

A commercial ferritin kit (Abbott AxSYM Ferritin) was calibrated using the WHO Human Liver Ferritin International Standard 80/602. The reconstituted WHO freeze-dried standard was diluted to obtain six concentration levels ranging from 10-840 micrograms/l. In the analysis of the data, logarithmic transformation of the results was performed in order to stabilize the variance. The AxSYM kit yielded slightly higher values than the WHO Ferritin Standard (p < 0.05). The relation between the AxSYM kit and the WHO Ferritin Standard (untransformed values) was described by a proportionality: FerritinAxSYM = 1.057 x FerritinWHO. WHO Ferritin Standard values of 12 and 15 micrograms/l (used as cut-off values for absent or small body iron reserves) yielded calculated AxSYM values of 12.7 and 15.9 micrograms/l. A WHO Ferritin Standard value of 30 micrograms/l (used threshold value for the presence of stainable bone marrow haemosiderin iron) yielded a calculated AxSYM value of 31.7 micrograms/l.

Smoking related to 24-h ambulatory blood pressure and heart rate: a study in 352 normotensive Danish subjects

This study shows the association between smoking and both office and ambulatory blood pressure. By means of stratification, a uniform number of subjects of both sexes and spanning 6 decades (aged 20 to 79 years) were recruited randomly from the local community register. A total of 352 subjects participated, including 161 smokers. Smokers (both sexes and all age groups summed), as compared with nonsmokers had statistically significant lower office blood pressure as follows (mean systolic +/- SED/mean diastolic +/- SED): (systolic and diastolic, -6.8 +/- 2.1/-3.9 +/- 1.3); day ambulatory blood pressure (diastolic, /-2.8 +/- 1.0); and night ambulatory blood pressure (systolic and diastolic, -4.2 +/- 1.8/-3.9 +/- 1.1). The intraperson variability of the day ambulatory blood pressure (as measured every 15 min) was identical for the smokers and the nonsmokers. Smokers were found to have a diminished "white coat" effect; this diminished white coat effect has not previously been described. The major white coat effect was seen in the older nonsmokers, whereas the diminished white coat effect was most pronounced in the older male smokers and in the younger female smokers. Smokers seem to have a diminished white coat effect, as well as a lower ambulatory blood pressure throughout the day (diastolic) and at night (systolic and diastolic). The similar intraperson variability found in the smokers' and nonsmokers' blood pressure further speaks for a consistently lower blood pressure in smokers as compared with nonsmokers.

[Round-the-clock blood pressure measurements in 352 persons--a reference material]

The aim of this study was to establish reference values for 24-hour ambulatory blood pressure in a Danish population stratified for gender and age in the decades from 20 to 79 years of age. A sample of 352 persons, 179 men and 173 women randomly selected from the local community register, age 20-79 years underwent 24-h ambulatory blood pressure monitoring. For men age < 50 daytime ambulatory blood pressure (median) was 125/79 mmHg and night time was 106/65 mmHg, for women the respective pressures were 113/77 mmHg and 97/64 mmHg. For men age > or = 50 daytime ambulatory blood pressure was 133/83 mmHg and night time was 124/86 mmHg, for women the respective pressures were 122/83 mmHg and 105/65 mmHg. Presently, we can only relate cardiovascular risk to clinic blood pressure. Therefore we have calculated corresponding ambulatory blood pressure values to WHO's upper limit 160/90 mmHg for normal blood pressure in the clinic and found 154/87 mmHg for daytime and 134/74 mmHg at night. For a clinic pressure of 95 mmHg the corresponding daytime value was 91 mmHg, for 100 mmHg it was 95 mmHg.

Comparison of ribotyping and genome fingerprinting of Pseudomonas aeruginosa isolates from cystic fibrosis patients

Forty Pseudomonas aeruginosa strains, previously characterized by pulsed-field gel electrophoresis, were ribotyped with EcoRI, BamHI, ClaI, and PvuII. Ribotyping with PvuII proved to be as discriminatory as pulsed-field gel electrophoresis with XbaI or DraI while EcoRI and BamHI were not. ClaI contributed further ribotypes, some of which might be due to a transposable element.

24-h ambulatory blood pressure in 352 normal Danish subjects, related to age and gender

The study was conducted to determine age and sex stratified normal values for 24-h ambulatory blood pressure. A sample of 352 healthy subjects (all white) were randomly selected from the community register and stratified by sex and age groups in decades from 20 to 79 years of age. Persons with a history of hypertension, cerebral apoplexy, diabetes, myocardial or renal disease, and who were taking blood pressure-influencing medication were excluded. Ambulatory blood pressure was recorded over 24 h, with measurements taken every 15 min from 07:00 to 22:59, and every 30 min from 23:00 to 6:59. Systolic blood pressure increased only slightly with age and was significantly higher in men than in women. The diastolic blood pressure increased only slightly with age in both sexes until the 50 to 59 years age group and declined thereafter. The diastolic blood pressure was not different for the two sexes. Both systolic and diastolic blood pressure were approximately 15% lower during the night regardless of age or sex. Ambulatory blood pressure during the daytime was on an average of 5 mm Hg lower than office blood pressure, but the mean difference between the two measurements increased with age. The variability of the difference also increased with age.

IN CONCLUSION

Normal values for ambulatory blood pressure are presented in a randomly selected age- and gender-stratified population. Differences between office blood pressure and ambulatory blood pressure increased with age suggesting that the previously observed higher blood pressure seen in the elderly partly might be explained by a greater impact of white coat hypertension in older people.

Palpable lymph nodes of the neck in Swedish schoolchildren

We studied 3592 Swedish schoolchildren, 8 or 9 years old, examined for palpable submandibular, cervical and supraclavicular lymph nodes. All children were skin tested with 2 TU PPD RT23 and with 0.1 microgram of Mycobacterium avium sensitin or 0.1 microgram of M. scrofulaceum sensitin. A total of 991 children had palpable lymph nodes in any of the three locations. Among them, 811 had lymph nodes in one location, 162 in two locations and 18 in three. In 312 children, the lymph nodes were > or = 5 mm in size in any location. The most common location was submandibular. Boys had a significantly higher prevalence of palpable lymph nodes than girls. There was also seasonal variation. Children infected by atypical mycobacteria (sensitin reaction > or = 6 mm) did not have a higher prevalence of palpable lymph nodes than those not infected.

Comparative skin testing with PPD tuberculin, Mycobacterium avium and M. scrofulaceum sensitin in schoolchildren in Saudi Arabia

SETTING

Jizan region, Saudi Arabia.

OBJECTIVE

To test methodology for studies of tuberculin sensitivity and effectiveness of BCG vaccination programme.

DESIGN

School children (n = 315) aged 6-12 years simultaneously tested intradermally with PPD tuberculin RT23, 2TU and 0.1 microgram Mycobacterium avium or M. scrofulaceum sensitin. Presence of BCG scar as evidence of previous BCG vaccination. Cervical lymph nodes palpated.

RESULTS

BCG coverage was 75%. The prevalences of positive reactions (induration > or = 6 mm) were higher among children with than without scar. Prevalences of positive reactions to PPD and M. scrofulaceum sensitin were higher among girls than boys. In children with scar, the mean size of positive reactions to PPD was larger among girls than boys, and the prevalence of positive reactions was smaller in this group among children with than without palpable cervical lymph nodes. The sizes of reactions both to M. avium and to M. scrofulaceum sensitin were correlated to the size of the tuberculin reactions. Previous admission to hospital was reported less often by children with than without scar.

CONCLUSIONS

The technique applied and training of staff was satisfactory. In further studies, however, we will apply three simultaneous tests to each person.

Calibration of the Amersham Ferritin RIA kit using the WHO human liver ferritin international standard 80/602

A commercial ferritin kit (Amersham Ferritin RIA (A)) was calibrated using the WHO human liver ferritin international standard 80/602 (W). The reconstituted WHO freeze-dried standard was diluted to obtain five concentration levels ranging from 10-800 micrograms/l. Logarithmic transformation of the values was performed in order to stabilize the variance, yielding the regression equation: logA = 0.0235 + 1.0022 logW. The slope of the regression line (being very close to, and not significantly different from, one) was set to one, and the relation between the untransformed values then became a proportionality: A = 1.067 x W. A WHO standard ferritin value of 15 micrograms/l (often used as cut-off value for absent iron reserves) and of 30 mu/l (often used as threshold value for the presence of stainable marrow haemosiderin iron) yielded calculated Amersham Ferritin RIA values of 16.0 micrograms/l and 32.0 micrograms/l.

Sensitivity to sensitins and tuberculin in Swedish children. Part 5: A study of school children in an inland rural area

SETTING

Since 1986 we have tested approximately 7000 non-BCG-vaccinated Swedish children with tuberculin and with Mycobacterium avium or M. scrofulaceum sensitin. In Göteborg, an urban coastal area, 25% of 8-9-year-old school children reacted to M. avium sensitin and 32% of M. scrofulaceum sensitin using a 6 mm cut-off.

OBJECTIVE

To evaluate if geographical factors have an influence on the prevalence of children reacting to tuberculin and sensitins.

DESIGN

2000 schoolchildren of the same age as those in Göteborg but living in an inland rural area were Mantoux-tested in a similar way (simultaneously on separate arms with PPD RT23 and either of the two sensitins).

RESULTS

15% reacted to PPD RT23, 9.7% to M. avium and 13.9% to M. scrofulaceum sensitin. None of the children with a PPD RT23 reaction > = 6 mm showed signs of tuberculosis or had any known exposure. A reaction to PPD RT23 was usually combined with a still larger sensitin reaction.

CONCLUSION

There was a considerable geographic difference in sensitin reactivity, low in an inland rural area compared to a coastal urban area. Children reacting to PPD RT23 had probably not been infected by M. tuberculosis but more likely by atypical mycobacteria. The reactions should be interpreted as cross-reactions.

Statistical pitfalls in the comparison between two commercial serum ferritin kits, Pharmacia and Amersham

Two commercial ferritin kits, Phadebas Ferritin PRIST (kit B) and Ferritin RIA Amersham (kit A) were compared in order to "translate" ferritin values from one kit to the other. Ferritin levels in 222 sera were determined with both kits in the concentration range 5-838 micrograms/l. Regression analysis disclosed a parabolic regression between the logarithmically transformed results obtained with the two kits. Measured kit B values of 10, 12, 15, 30 and 300 micrograms/l corresponded to calculated kit A values of 15, 17, 20, 34 and 321 micrograms/l, respectively. In kit A, storage of sera for two years at -25 degrees C in combination with freeze-thawing three times produced a minor fall (p < 0.0001) in ferritin levels with a median percent decline of 16%.

Catheter-related Staphylococcus aureus infections

Among 3394 patients with Staphylococcus aureus bacteraemia from the years 1986-89, 88 patients were found whose intravenous catheter and blood grew organisms of the same phage type. Strains of phage type 95 were more frequent among the patients with confirmed catheter-related bacteraemia than among other bacteraemia cases. Strains with particular phage-type patterns occurring with increasing frequency in Denmark during recent years also occurred with significantly higher frequencies among the confirmed catheter-related bacteraemias. No major differences in antibiotic resistance were observed. Patients with catheter-related bacteraemia had, in spite of a higher frequency of underlying diseases, a lower mortality compared with other bacteraemia patients, and endocarditis occurred less frequently (2% vs. 6%). Among 201 S. aureus isolates from catheters in 1988 only strains of group I occurred with increased frequency. The possible role of catheters as selection pressure on the S. aureus population is discussed.

Rabies vaccine standardization: International Collaborative Study for the Characterization of the fifth International Standard for Rabies Vaccine

A collaborative study was carried out to establish a replacement for the International Standard for Rabies Vaccine, the stocks of which are exhausted. Three rabies vaccines for human use derived from different rabies virus strains and prepared on different cell culture substrates were compared with the International Standard for Rabies Vaccine using in vivo and in vitro assay methods in a collaborative study involving 14 participants. The proposed fifth International Standard (PISRAV) which was derived from the same virus strain as the present international standard preparation, the Pitman Moore (PM) strain, was found to be approximately twice as potent relative to the International Standard in immunogenicity assays as in antigenicity assays. On the other hand another vaccine, derived from the LEP strain, was considerably more potent in antigenicity assays than in immunogenicity assays. The glycoprotein of the proposed replacement standard measured in antigenicity assays appeared to be stable at +37 degrees C for 245 days, whereas the immunogenicity of the proposed replacement vaccine was sensitive to this heat treatment and the vaccine lost 66% of its immunogenic potency. The results of this study indicate that the NIH protection test should continue to form the primary basis for potency assay of rabies vaccine as glycoprotein content does not appear to correlate with immunogenic potency for different types of vaccine. The vaccine coded PISRAV has been established as the fifth International Standard for Rabies Vaccine and a potency of 16 International Units of Rabies Vaccine (based on the immunogenicity assays) assigned to the contents of each ampoule. Each ampoule has also been assigned a unitage of 10 IU of PM Rabies Virus Glycoprotein and 135 IU of PM Rabies Virus Ribonucleoprotein.

Relation between enzyme-linked immunosorbent assay and radioimmunoassay for detection of antibodies to the capsular polysaccharide of Haemophilus influenzae type b

The measurement of antibodies to the capsular polysaccharide (PRP) of Haemophilus influenzae type b (Hib) is important because vaccines inducing such antibodies are now available. We developed and evaluated an enzyme-linked immunosorbent assay (ELISA) for detection of these antibodies based on direct coating of the plates with tyraminated PRP. The assay fulfilled the requirements for parallel line assays; it was sensitive, specific, and reproducible with a coefficient of variation between days of 19%. Results from the ELISA were compared with results from radioimmunoassay and a correlation coefficient of 0.93 was found. Results obtained by the two methods were proportional and the relation was independent of the antibody level. The relation between them was also unaffected by the contribution of different antibody isotypes, indicating that these were measured to the same extent by both methods. ELISA employing direct coating of the plates with tyraminated PRP represents a useful alternative for detection of antibodies when studying immunogenicity of Hib vaccines.

Enzymuria in neonates receiving continuous intravenous infusion of gentamicin

Urinary excretion of the tubular enzymes NAG and AAP was investigated during gentamicin treatment of 105 newborn infants. The values found for NAG and AAP show a significant positive correlation. The urinary excretion of NAG was on the average 92% higher during gentamicin treatment as compared with non-treatment periods in the same newborn infant (33 infants). The same tendency applied to AAP. Newborn infants receiving continuous intravenous infusion of gentamicin were not found to be at greater risk of nephrotoxicity than those receiving intermittent gentamicin treatment, using NAG and AAP as an index of nephrotoxicity. The changes in NAg and AAP within treatment periods were studied. During gentamicin treatment an insignificant average increase in the urinary excretion of NAG occurred, whereas a significant decrease was found during non-treatment periods. A significant negative correlation was found between urinary excretion of NAG and birth weight/gestational age. The long-term effect of the higher excretion of NAG and AAP in newborn and adult patients during aminoglycoside treatment is unknown.

The cell mediated and humoral immune response to vaccination with acellular and whole cell pertussis vaccine in adult humans

The cell mediated immune response (CMI) against pertussis antigens following vaccination with the traditional Danish whole cell pertussis vaccine (WC-P) and the Japanese acellular pertussis vaccine (A-PV) JNIH-3 was studied in four adult human volunteers. Vaccination with the A-PV induced an in vitro proliferative response of peripheral blood lymphocytes to pertussis toxin (PT) subunits S2-S4, S3-S4 and S5 and the filamentous hemagglutinin (FHA), and a better serological response to native PT, detoxified PT (dPT) and FHA than the WC-PV. The induced CMI and serological response were followed over a period of 17 weeks, and were not seen to decline during this period. Further, an in vitro proliferative response to Bordetella pertussis agglutinogen 2 and 3 were demonstrated using lymphocytes from recently and not-so-recently pertussis-vaccinated adults.

MPB 64 possesses 'tuberculosis-complex'-specific B- and T-cell epitopes

We have developed monoclonal antibodies (MoAb) reactive with a protein from Mycobacterium tuberculosis of apparent molecular mass 24 kDa. This protein was shown to be identical with MPB 64 (Harboe et al.,) MoAb bound to four different epitopes of which two were restricted to the 'tuberculosis complex' and two were also found in mycobacteria not belonging to the 'tuberculosis complex'. The cross-reactive MoAb demonstrate that MPB 64 is present in more mycobacterial species than previously assumed. MPB 64 was shown to induce strong delayed type hypersensitivity (Dth) reactions in outbred guinea pigs immunized with M. tuberculosis and M. bovis bacille Calmette-Guérin (BCG). No reaction was observed in animals immunized with mycobacteria not belonging to the 'tuberculosis complex'. The Dth-inducing capacity of MPB64 was compared with that of another 24 kDa protein purified from M. tuberculosis and of the previously described 38 kDa protein. The Dth responses to these three antigens were further analysed in four inbred guinea pig strains. A genetic restriction of the ability of the animals to respond to MPB 64 as well as to the 38 kDa protein was observed.

Sensitivity to sensitins and tuberculin in Swedish children. III. Sequential versus simultaneous skin testing

The aim of this study was to determine whether simultaneous and sequential skin testing with tuberculin and sensitins give consistent results. A total of 475 8- or 9-year-old schoolchildren were skin tested sequentially, at an interval of 3 days, with PPD tuberculin and with either Mycobacterium scrofulaceum or M. avium sensitin. The results were compared with those of 470 simultaneously tested children chosen from the same living area. There were no statistically significant differences between the frequencies of the reactions of sequentially and simultaneously tested children. When the sequential testing procedure was employed, 3.1% reacted to tuberculin, 19% to M. avium sensitin and 30% to M. scrofulaceum sensitin, taking a 6 mm cut-off. The corresponding figures for the simultaneously tested children were 4.7, 21 and 36%, respectively. Thus, there was no indication that the simultaneous testing procedure in itself influenced the results, neither was there any sign of a booster effect when testing in sequence with an interval of 3 days in non-BCG-vaccinated children.

Ten and a half years seroepidemiology of Mycoplasma pneumoniae infection in Denmark

The study was based on a computerized card index of 9161 patients who had at least one positive blood specimen in the Mycoplasma pneumoniae complement fixation test. A total of 12,562 specimens from these patients had been sent to Statens Seruminstitut from hospitals and general practitioners during a 10.5-year period. The period encompassed a previously described endemic period in a 30-year study of the epidemiological pattern of M. pneumoniae infection in Denmark. The serological data presented support the hypothesis advanced here that a more than sixfold increase of children in day care might have contributed to a change in the epidemiological pattern. The correlation between age and level of specific antibodies, as well as persistence of seropositivity, were also investigated.

Changing pattern of bone and joint infections due to Staphylococcus aureus: study of cases of bacteremia in Denmark, 1959-1988

Of the 15,170 cases of bacteremia due to Staphylococcus aureus that occurred in Denmark between 1959 and 1988, we review 525 cases of acute hematogenous osteomyelitis and 185 cases of septic arthritis that developed subsequent to the bacteremia and 134 cases of contiguous osteomyelitis in which the bacteremia developed secondarily. The pattern of acute infections of bones and joints has changed over the three decades studied. The frequency of secondary bone or joint infections due to S. aureus bacteremia has changed, as have the phage-type pattern and antibiotic resistance of the infective strains. The prevalence of hospital-acquired cases has increased and the age distribution of patients has changed, as is reflected in an increasing number of older patients. The localization of hematogenous osteomyelitis has shifted, and the vertebral column is now the most common site of infection. The rate of chronic cases of osteomyelitis that occur following acute hematogenous osteomyelitis has been reduced from 34% to 6%. The mortality associated with S. aureus bacteremic infections of bones or joints is low compared to that associated with other cases of S. aureus bacteremia.

The epidemiology of Neisseria gonorrhoeae isolates in Dakar, Sénégal 1982-1986: antimicrobial resistance, auxotypes and plasmid profiles

A total of 460 Neisseria gonorrhoeae isolates from patients seen at three clinics in Dakar, Sénégal, 1982-1986, have been investigated. In this period a significant change in antimicrobial susceptibility was observed: the percentage of strains susceptible to penicillin (MIC less than or equal to 0.08 micrograms/ml) fell from 61 to 18 (p less than 0.0001) and the percentage of resistant strains (MIC greater than or equal to 1.2 micrograms/ml) increased from 18 to 46. Among penicillin-resistant strains the proportion of penicillinase-producing strains (PPNG) was fairly constant (range 35-55%). The determination of susceptibility to anti-microbial agents performed locally allowed detection of approximately all PPNG strains whereas the increase in the occurrence of strains with chromosomally determined resistance was not revealed. The study comprised 70 PPNG strains of which 19% (13/70) carried the 7.4 kb Asian plasmid and 81% (57/70) the 5.3 kb African plasmid. None of these strains possessed the 38 kb conjugative plasmid, whereas it was found in 4.5% of the 376 non-PPNG strains available for plasmid analysis; 92% (410/446) of all strains had the small 4.2 kb plasmid and 5.4% (24/446) did not contain any plasmid. Overall, auxotype zero and proline-requiring strains were predominant, accounting for 53% (244/460) and 28% (131/460), respectively. In general, PPNG strains carrying the 5.3 kb plasmid were auxotype zero (49/57 = 86%) and those carrying the 7.4 kb plasmid were proline-requiring (9/13 = 69%).

T-cell proliferative response to antigens secreted by Mycobacterium tuberculosis

An infection model of human tuberculosis was established with C57BL/6J mice. The lymphocyte proliferative responses to antigens from Mycobacterium tuberculosis were investigated during the course of infection and compared with results obtained with a group of mice immunized with large amounts of killed bacteria. The two groups responded similarly to a number of mycobacterial antigens, but marked differences in responses against secreted antigens were found; only infected mice responded vigorously to these. The responding lymphocyte subpopulation was made up of L3T4+ T lymphocytes under restriction of the Ia molecule.

Proliferative response to seven affinity purified mycobacterial antigens in eight strains of inbred mice

This study compares the T-cell-stimulating ability of different mycobacterial antigens. The responses to crude culture filtrates and seven affinity-purified antigens were investigated in eight strains of inbred mice. Large differences in the stimulating abilities of the antigens were observed, and four antigens were found to give a powerful T-cell stimulation. Some antigens divided the strains into high and low responders, while a 17-kDa antigen was found to be exceedingly T-cell stimulatory in mice of all tested haplotypes. The responses of the eight strains were analyzed by comparing the response patterns of the strains. Using a statistical model based on antigen ranking, five strains were found to have a similar response pattern; three strains were found to differ. These results demonstrate the significance of the choice of mouse strain in studies of mycobacterial immunology and, furthermore, indicate that when research is conducted to develop new mycobacterial vaccines, it is important to include panels of antigens.

Sensitivity to sensitins and tuberculin in Swedish children. I. A study of schoolchildren in an urban area

Non-BCG-vaccinated schoolchildren (8 or 9 years of age) were simultaneously tested on separate arms with 2 IU PPD RT23 and 0.1 microgram Mycobacterium avium sensitin RS10 or 0.1 microgram Mycobacterium scrofulaceum sensitin RS95. None of the 2819 analysed children had any known exposure to tuberculosis. A total of 3.4% reacted with an induration greater than or equal to 6 mm to PPD RT23. Half the number of children were tested with M. avium sensitin and 25.4% reacted while the remaining were tested with M. scrofulaceum sensitin and 32.4% reacted when the cut-off was 6 mm. For about 90% of the children the sensitin reaction was larger than or equal to the tuberculin (PPD RT23) reaction. Correlation analyses showed that moderate and high PPD RT23 values were combined with still higher sensitin values, indicating that the tuberculin reactions were mainly cross-reactions due to the antigenic similarity between tuberculin and sensitins. The presence of birds, dogs and cats in the homes was combined with an increased frequency of children reacting to the sensitins used. The children with reactions to PPD RT23 greater than or equal to 6 mm were examined and chest X-rays were performed. None of them showed any signs or symptoms of mycobacterial disease. In non-BCG-vaccinated Swedish schoolchildren without clinical signs of tuberculosis and without known contact with a contagious tuberculous person, indurations less than 12 to 14 mm on tuberculin testing are probably caused by atypical mycobacteria. In such cases sensitin tests should be performed to verify the suspicion.

Sensitivity to sensitins and tuberculin in Swedish children. II. A study of preschool children

Non-BCG-vaccinated preschool children (4 or 5 years of age) were simultaneously tested on separate arms with a 2 IU PPD RT23 and 0.1 microgram Mycobacterium avium sensitin RS10 or 0.1 microgram Mycobacterium scrofulaceum sensitin RS95. None of the 762 children had any known exposure to tuberculosis. A total of 8.8% reacted with an induration (greater than or equal to 3 mm to PPD RT23 while 2% reacted with greater than or equal to 6 mm. Half the children were tested with M. avium sensitin: 18.9 and 7.8% reacted when 3 and 6 mm cut-off points, respectively, were taken. The remaining children were tested with M. scrofulaceum sensitin: 18.4 and 6.3%, respectively, reacted. In a previous study of schoolchildren aged 8 or 9 years, reactions to sensitins were considerably more frequent. Thus, sensitisation by atypical mycobacteria seems to increase from the preschool to the early school age. This finding probably reflects a continuous exposure of the children to atypical mycobacteria from various sources. The preschool children with a reaction to PPD RT23 greater than or equal to 6 mm were examined and chest X-rays were performed. All children were healthy but one child had enlarged lymph nodes in the mediastinum and abdomen. It cannot be excluded that these pathological findings were caused by atypical mycobacteria.

A subdivision of strains of Staphylococcus aureus in the 94,96 complex by means of experimental phages

In order to facilitate epidemiological investigations a subdivision of Staphylococcus aureus strains belonging to the 94,96 complex by means of two experimental phages, 16 and 47A, was performed. These phages were selected from the nine experimental phages initially examined because they gave the greatest discrimination. On the basis of reactions with these two phages, 2199 isolates which reacted with phages 94 and 96, and 773 isolates which reacted with phage 96 alone, were each subdivided into two major and two minor groups. Strains with different phage patterns were in a few cases (2/64) isolated from the same deep body site in a patient, and lysogenisation experiments suggested that differences in phage patterns were determined by the presence of prophages. Strains with the phage patterns 94/96 and 96 were found to be unevenly distributed throughout Denmark. This regional distribution suggested that particular strains might predominate in some areas. The extended phage patterns with the experimental phages did not give any retrospectively useful epidemiological information. It is proposed that in future phages 16 and 47A be used for specific investigations into the sources and relatedness of strains involved in small incidents.

[Treatment of gonorrhea at the Venereal Disease Clinic in Copenhagen in 1985. A study of the efficacy of standardized treatment compared with the sensitivity of Gonococcus to penicillin in vitro]

In 1985, a total of 1,140 patients (907 men and 503 women) were treated for gonorrhoea at the Copenhagen County Outpatients Clinic at Rudolph Berghs Hospital. Failure of the standard treatment regimen (pivampicillin plus probenecid; patients stating penicillin allergy received a Sulfotrim-regimen) occurred in 79 (5.6%). A significant association between the in vitro susceptibility to penicillin and the efficacy of the standard treatment regimen was found; among 1,139 patients with uncomplicated urogenital gonorrhoea caused by penicillin susceptible gonococci, the failure rate was low (0.4-1.9%); the failure rate was high in patients infected with penicillin resistant gonococci. Continued surveillance of the in vitro antimicrobial susceptibility of gonococci is recommended as a basis for the choice of standard treatment regimen.

Importance of blood volume cultured in the detection of bacteremia

The influence of the volume of blood cultured on the rate of detection of bacteremia was evaluated in a routine 12-tube blood culture system using 1693 samples from 1502 patients. Blood samples were drawn simultaneously into two transport tubes. The blood volume cultured was the only varying parameter. Generally, 17% more cultures with clinically significant microorganisms (both Enterobacteriaceae and gram-positive cocci) were found when blood from two instead of one tube was used (in most cases comparing 13-16 ml of blood with 6.5-8 ml). Of the most prevalent species, the maximum average extra yield was observed for Staphylococcus aureus (26%) followed by Escherichia coli (16%) and Streptococcus pneumoniae (12%). In adults most cases of bacteremia are low-grade. The grade of bacteremia in our patient population was on average as low as 0.25 CFU/ml blood. Therefore, all patients suspected of having bacteremia should have the benefit of a sufficient volume of blood cultured. Since the volume of blood cultured seems to be the single most important factor in the detection of bacteremia, it is imperative that the volume is the same in comparative studies of different blood culture systems.

Resistance to dicloxacillin, methicillin and oxacillin in methicillin-susceptible and methicillin-resistant Staphylococcus aureus detected by dilution and diffusion methods

A total of 54 Staphylococcus aureus strains of varying methicillin resistance were investigated for their resistance to methicillin, oxacillin and dicloxacillin by different diffusion tests. Inhibition zones were measured around locally prepared paperdiscs with 10 micrograms methicillin, 5 and 10 micrograms oxacillin, 5 and 10 micrograms dicloxacillin, PDM paperdiscs with 10 micrograms methicillin or oxacillin and Neo-sensitabs tablets with methicillin or oxacillin. All diffusion tests were performed both with Mueller-Hinton agar and Danish Blood agar as well as at 37 degrees C and 30 degrees C and read after overnight incubation. Differences in zone diameter under different conditions were found to be independent of the susceptibility level of the strains. Seventeen of the strains were detected as methicillin-resistant (MRSA) by two methods including high inoculum and prolonged incubation at 30 degrees C. The minimum inhibitory concentration (MIC) of the 54 strains was determined by a plate dilution method at 30 degrees C and 37 degrees C. A 10 micrograms locally prepared methicillin disc detected all MRSA strains with no false reactions either at 37 degrees C or 30 degrees C on Mueller-Hinton agar. Investigations with oxacillin discs had to be performed at 30 degrees C or with a 5 microgram disc in order to detect correctly. PDM paperdiscs gave reactions identical to the corresponding locally prepared discs. Methicillin Neo-sensitabs detected all MRSA strains but also included a few susceptible strains among the resistant ones. Addition of blood increased the number of not-detected MRSA strains. All 17 MRSA strains were susceptible to dicloxacillin by the dilution method, and the disc diffusion test showed similar results. Dicloxacillin discs therefore did not detect the presence of MRSA strains. The implications of replacement of the methicillin/oxacillin disc by a dicloxacillin disc are discussed.

Potency assay of antibodies against rabies. A report on a collaborative study

The relative potencies of a number of rabies immunoglobulin preparations were estimated in an international collaborative study comprising eight laboratories in five countries. Two assay methods were used: a virus neutralization test in mice (MNT) and a virus neutralization test in cell culture (RFFIT). Differences between the results obtained by the two methods, which have been reported, could not be generally corroborated. The results indicate that in some laboratories the MNT cause difficulties and give results different from those obtained by RFFIT. In other laboratories such difficulties are not encountered. The results seem to indicate that the RFFIT is a more reliable method than the MNT.

Estimation of guinea pig antigen-specific and non-specific suppressor cell activity

A functional assay for the quantitative estimation of suppressor cell (SC) activity in guinea pigs has been developed. Cultures of antigen-stimulated peripheral blood lymphocytes (PBL) from sensitized guinea pigs develop SC activity. The suppression of proliferation can be demonstrated in antigen-stimulated autologous co-cultures of precultured and freshly isolated PBL. The extent of suppression is dependent on the preculture antigen concentration but not the preculture period and it consists, as demonstrated with PBL from doubly sensitized guinea pigs, of an antigen-specific and a non-specific component. The observed SC activities were not due to an alteration of the kinetics of the co-cultures. The estimates of suppression are highly dependent on corrections for the values of the control cultures. The present method may prove useful in immunological studies of mycobacterial infections in guinea pigs.

Coronary risk factors, development of myocardial infarction, and plasma oestrogens: a prospective case-control study in men

A number of studies have reported hyperoestrogenaemia in men surviving an acute myocardial infarction (AMI). This has led to speculations that hyperoestrogenaemia might be a coronary risk factor. It is not clear why plasma levels of oestrogens should be elevated in coronary heart disease. To ascertain whether hyperoestrogenaemia might be present before the onset of a myocardial infarction, we performed a prospective study in 252 men above the age of forty who within the following 5 years suffered an AMI and, as controls, 526 men matched for age and coronary risk factors and 329 randomly selected men. Mean plasma concentrations of oestradiol and oestrone did not differ significantly between the groups. This suggests that hyperoestrogenaemia is not a coronary risk factor and thus, if present after the AMI, is more likely develop concurrently with the myocardial infarction.

Scintimetric assessment of synovitis activity during treatment with disease modifying antirheumatic drugs

In a double blind trial of 36 patients with rheumatoid arthritis a new scintimetric method was applied to three comparable patient groups before and after eight months' treatment with levamisole, penicillamine, or azathioprine. Technetium-99m pyrophosphate scintigraphy of both hands was performed on a gammacamera with a computer attached, immediately after the administration of the tracer. The uptake ratio of each proximal interphalangeal (PIP) joint and the mid-half of the adjacent proximal phalanx was calculated from the activity counted for one minute. A scintimetric index was expressed as the sum of eight uptake ratios. This index was higher for each of the three patient groups before start of treatment than that for 10 age matched controls. After eight months of treatment the index, the number of PIP joints with clinical signs of synovitis, and the total circumference of the PIP joints decreased in the penicillamine and azathioprine groups. The scintimetric method reliably reflected local synovitis activity and its changes but, like grip strength and PIP circumference, was not a representative measure of the overall activity of the disease.

Changes in the epidemiological pattern of Mycoplasma pneumoniae infections in Denmark. A 30 years survey

A seroepidemiological survey has shown a remarkable shift in the previously reported regular cyclic pattern of Mycoplasma pneumoniae epidemics which culminated every 4.5 years during the period 1958-74. The last of four regular epidemics occurred in 1972. It was followed by 'premature' epidemics in 1975 and 1977/8 which inaugurated a change from an epidemic to an endemic pattern of the infection in Denmark. Over the following 9 years (1978-86) there has been an irregular but significant decrease in the annual number of seropositive samples with the usual high incidence during winter seasons. This endemic period terminated in the fourth trimester of 1987 with the development of a new epidemic. The hypothesis is advanced that a sixfold increase of children in day care may have influenced the change from an epidemic to an endemic situation which after 9 years led to a new epidemic of M. pneumoniae infection.

Colonization priority among Staphylococcus aureus strains--correlation with phage-type

We have studied the distribution of phage-type patterns among strains of Staphylococcus aureus isolated from patients in a burns unit. From 51 patients the same phage-type was isolated from succeeding swabs during the observation period. In 20 patients new types were introduced, but the original strain remained. In 23 patients the first strain was replaced by one other strain, in eight patients two or more. Strains of type 95 seemed to have a high colonization priority, whereas strains of group III had a low one. In 1986 phage-typing was performed on two or more S. aureus strains from the same patient, in 4561 instances. Recurrence of strains of the same phage-type pattern was demonstrated in 70% of the patients when the first and the fourth sample were compared. The "newer epidemic" strains of phage-type 95 and of the 94,96 complex had the highest percentage of recurrence (more than 80%) when adjacent samples were compared, and 68-69% when the first and the fourth sample were compared. The good colonization capacity of these strains might be one of the explanations why they occur frequently today although they are resistant only to penicillin.

In-vitro activity and beta-lactamase stability of methicillin, isoxazolyl penicillins and cephalothin against coagulase-negative staphylococci

Forty-nine clinical strains of coagulase-negative staphylococci were investigated for susceptibility to methicillin, oxacillin, cloxacillin, dicloxacillin, flucloxacillin and cephalothin. The highest level of resistance was found to methicillin and the lowest to cephalothin. The resistance-level of the isoxazolyl penicillins showed a high degree of uniformity. However more strains were resistant to cloxacillin and oxacillin than to dicloxacillin and flucloxacillin. Only a weak correlation was found between beta-lactamase production, and resistance to the six antibiotics. Methicillin was the most stable. The inactivation of cephalothin differed from that of the other antibiotics.

Comparative analysis of two blood culture systems (Isolator and a 12-tube system) by cumulative differences in detection power at different times during incubation

A lysis-centrifugation blood culture system (Isolator) and a conventional system (4 tubes of nutrient broth, 4 tubes of semisolid agar, and 4 tubes of thioglycollate agar) were compared after different lengths of incubation by cumulative scoring of differences in detection power. After the first half day of incubation, the Isolator system was already significantly faster in detecting isolates of clinical significance (15 vs. 4, P = 0.02). Maximum difference in first or only detection system was seen after two days of incubation and was based on an overall superior detection of Staphylococcus aureus (11 vs. 0, P = 0.001), and an earlier detection of Enterobacteriaceae (30 vs. 13, P = 0.01) in the Isolator system. On the contrary, the detection of Streptococcus pneumoniae was significantly inferior in the Isolator system (0 vs. 10, P = 0.002). The earlier finding of clinically significant microorganisms in the Isolator system certainly contributes to good patient-care. A drawback of the Isolator system was the finding of clinically insignificant coagulase-negative staphylococci in 11%, compared with 1% in the conventional system. This led to a considerable waste of time and materials in the laboratory. The comparison of the two blood culture systems, based on statistical analysis of cumulative differences in detection power, expressed as the earliest or only findings, gives the optimal information, and is in our opinion the clinically most relevant comparison.

Susceptibility to diphtheria in populations vaccinated before and after elimination of indigenous diphtheria in Denmark. A comparative study of antitoxic immunity

The need for routine diphtheria revaccination is still controversial. Only single cases of diphtheria have been observed in Denmark since the mass vaccinations in the 1940s and the introduction of routine vaccination of infants in 1950, despite the fact that general revaccination has not been recommended. An investigation of antitoxin immunity in 1.188 probands 2-69 years of age, randomly or cluster selected, indicated that immunity in the Danish population is still above the limit generally believed to guard against diphtheria epidemics (around 70% being immune in a population). The highest frequency of susceptibility (46%) was found among females 30-39 years of age. Serum antitoxin concentrations in 529 subjects with documentation for complete primary vaccination 1-40 years previously corresponded to a continuous fall-off. Relative to time from vaccination, individuals born when diphtheria occurred frequently in Denmark had significantly higher antitoxin levels than those born later, and among children susceptibility had increased considerably as compared to observations in the 1950s. These phenomena were explained by the effect of natural immune stimulation previously. The present concept of relatively high frequencies of immune subjects also in other western countries may not be valid in the future, when the number of subjects born after the elimination of indigenous diphtheria increases. General revaccinations seem required to maintain herd immunity.

Production, assay and partial characterization of guinea pig interleukin 2

Optimum conditions for the production and assay of guinea pig interleukin-2 (IL-2) have been established. The mitogenic activities of serial dilutions of guinea pig IL-2 preparations were compared in cultures of guinea pig peripheral blood lymphocytes prestimulated for 7 days with phytohemagglutinin (PHA) used at 1 microgram/ml. Parallel log dose-log response curves were used for quantitative comparisons. Optimum IL-2 yields were obtained from cultures of lymph node lymphocytes stimulated for 20 h with Concanavalin A (ConA) at 5 micrograms/ml. Guinea pig T cell lines reactive to mycobacterial antigens were propagated for several months using our IL-2 preparations. The molecular weight of guinea pig IL-2 was estimated to be 30,000 using S-200 gel filtration. The species specificities of guinea pig, human, mouse and rat IL-2s were examined. It was shown that guinea pig T lymphocyte blasts were stimulated only weakly with human IL-2 and not at all with mouse and rat IL-2.

Biological activity in sensitized guinea pigs of MPB 70, a protein specific for some strains of Mycobacterium bovis BCG

MPB 70 is a protein found in large quantities in the culture filtrate (CF) of the Tokyo and some other strains of Mycobacterium bovis BCG, and it has a remarkable degree of specificity for these strains. We estimated the molecular weight of MPB 70 to 22,000 by sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE). SDS-PAGE and immunoblotting showed that MPB 70 was present in high quantities in CF from BCG Tokyo, that it could be also demonstrated in BCG Copenhagen, and that it was absent in CF from M. tuberculosis H37Rv. When the purified MPB 70 preparation used in the present study was run in SDS-PAGE, blotted and stained with a polyclonal rabbit or a monoclonal mouse anti-MPB 70 antibody, several bands in addition to the main 22 kDa band were seen, indicating a tendency of the MPB 70 molecules and/or fragments thereof to form very stable aggregates with themselves. The biological activity of MPB 70 was studied in groups of guinea pigs sensitized with live BCG of the Tokyo and Copenhagen strains. Guinea pigs from both groups developed reactivity to tuberculin PPD as assessed by skin tests and lymphocyte stimulation tests with peripheral blood or lymph node lymphocytes. In addition, a strong and persistent reactivity to MPB 70 was demonstrated in the BCG Tokyo group with both methods. Guinea pigs sensitized with the Copenhagen strain were only weakly reactive to MPB 70. Skin reactions in guinea pigs that had been repeatedly tested with MPB 70 and tuberculin were compared with reactions in animals tested only once. Reactions to MPB 70 in BCG Tokyo sensitized guinea pigs were suppressed by repeated tests, whereas tuberculin reactions were boosted by the interim tests. The levels of specific anti-MPB 70 antibodies were higher in BCG Tokyo- than in BCG Copenhagen-sensitized guinea pigs. MPB 70 has a high degree of specificity and is a strongly immunogenic protein, which may prove useful in studies of mycobacterial immunology.

Experimental pneumococcus infection in mice: comparative in vitro and in vivo effect of cefuroxime, cefotaxime and ceftriaxone

In a mouse model using intraperitoneal inoculation of Streptococcus pneumoniae type 3, the 50% effective dose, ED50, after single doses one hour post-inoculation was considerably lower for ceftriaxone (CRO) than for cefuroxime (CXM) and cefotaxime (CTX), in spite of the same minimal inhibitory concentration, MIC, of 0.02 mcg/ml against the pneumococcus for all 3 drugs. The bactericidal activity as measured by time-kill curves was similar for the 3 drugs, as was the post-antibiotic effect in vitro. Protein binding in mouse serum was considerably higher for CRO (87%) than for both CTX (35%) and CXM (15%), respectively. Of pharmacokinetic parameters investigated on doses equal to the ED50s, the time the serum antibiotic concentration remained above the MIC (delta T(MIC)) was the factor that varied the least among 3 drugs. Therefore, the superior in vivo effect for CRO is not due to higher intrinsic activity against the pathogen but to the long serum-elimination half-life resulting in an extended delta T(MIC), probably related to the high serum protein binding.

Acute phase proteins and clinical synovitis activity in patients with rheumatoid arthritis

A number of laboratory variables, including Hb., ESR and several phase proteins, fluctuated in concord with the clinical signs of synovitis activity in patients with rheumatoid arthritis during a controlled study of 3 disease-modifying anti-rheumatic drugs (DMARD). The correlation between laboratory variables and clinical synovitis was significant in a large patient population but the correlation coefficients were not of such magnitude that any of the laboratory variables reflected clinical synovitis activity in a reliable manner in the individual patients. In patients treated with azathioprine, the response of the Hb, (and consequently of the ESR), was reduced compared to patients given other DMARD. This phenomenon was caused by the bone marrow suppressing effect of azathioprine. However, the effect of azathioprine on the clinical synovitis activity did not differ from that of the 2 other drugs. Similar results were found by reviewing the literature about controlled trials of DMARD. In the present trial the clinical evaluation was performed under optimal conditions. In daily clinical practice the evaluations of the joints may be less than optimal since they may be performed by different rheumatologists with varying experience. Consequently, it may be difficult to do without the unreliable laboratory variables mentioned in the routine assessments of disease activity, unless the quality of routine evaluations of synovitis activity is improved considerably.

Evaluation of vaccination requirements to secure continuous antitoxin immunity to tetanus

To investigate minimal requirements for tetanus revaccination to secure continuous protection, recently recommended by WHO, 637 subjects with documented vaccination history were studied. Antitoxin concentration in serum relative to time corresponded to a steep decline in the first years after vaccination continuing exponentially. By multiple regression analyses duration of immunity after three-dose primary vaccination was calculated to be 5 years (upper 95% confidence limit of estimated risk of serum antitoxin concentration below 0.01 IU ml-1 still less than 0.1%). Serum antitoxin concentration relative to time after revaccination depended upon age at revaccination and interval from primary vaccination. When given in childhood 5 years after primary vaccination revaccination was calculated to offer protection for approximately equal to 21 years, but protection was considerably shorter when given to the elderly. Cross-sectional and longitudinal analyses were compared and statistical approaches were introduced which may be generally applicable for evaluation of vaccination programmes. It was concluded that a vaccination programme consisting of primary vaccination in infancy and one revaccination 5 years later will secure continuous protection to about the age of 25 years. This is considerably simpler than programmes recommended in many countries, in which risk of hyperimmunization is apparent.

Comparative in vitro activities of pefloxacin, ofloxacin, enoxacin and ciprofloxacin against 256 clinical isolates

The antibacterial activity of four new fluoroquinolone carboxylic acids, pefloxacin, ofloxacin, enoxacin and ciprofloxacin, against 256 clinical isolates was investigated by means of an agar dilution method. Generally, all quinolones tested had a high activity against Gram-negative bacteria. More than 90% of Enterobacteriaceae strains were inhibited by a quinolone concentration of 0.4 microgram/ml. Also strains usually resistant to conventional beta-lactam antibiotics, and sometimes to third-generation cephalosporins, like Enterobacter spp., Serratia spp, and Yersinia spp. were susceptible to the tested quinolones. Ciprofloxacin was 5 to 25-fold more potent on a weight basis against Enterobacteriaceae than the other quinolones. Neisseria meningitidis, Neisseria gonorrhoeae, and Haemophilus influenzae were extremely susceptible to the new quinolones. Ciprofloxacin was about 10 times more potent against Pseudomonas aeruginosa than the other quinolones, and was the only quinolone that was sufficiently active against all tested P. aeruginosa strains (MIC less than or equal to 0.4 microgram/ml). The activity against Gram-positive bacteria was considerably lower. All the quinolones investigated had an acceptable activity against many of the methicillin-sensitive and methicillin-resistant Staphylococcus aureus and coagulase-negative staphylococci. The majority of the Streptococcus spp. tested was quinolone-resistant, and was Listeria monocytogenes. Generally, it was evident that ciprofloxacin was more potent on a weight basis than the other quinolones, but this difference was counterbalanced by a higher achievable serum concentration for ofloxacin. Some of the investigated fluoroquinolones might constitute valid therapeutical alternatives to beta-lactam antibodies and aminoglycosides in the treatment of serious bacterial infections.