Short Report: Translation of Analysis Results between Serum Ferritin Assays, Ferritin RIA Amersham™ and Abbott AxSYM™ Ferritin.

The serum ferritin assays, Ferritin RIA Amersham™ and Abbott AxSYM™ Ferritin were compared in order to translate values from one assay to the other. Serum ferritin was analysed with both assays in 102 samples. Logarithmic transformation of the results was performed in order to stabilize the variance. The relationship between the untransformed values was most exactly expressed by a proportionality: AxSYM Ferritin = 0.873 * RIA Ferritin. Due to this proportionality, the numerical difference between the assays increases with the ferritin concentration, although the percentage difference between the assays remains constant.

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

UNLABELLED: 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]. / 24 timers ambulant blodtryk hos 352 personer--et referencemateriale.

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.

UNLABELLED: 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.