Combined imipenem/cilastatin and tobramycin therapy of multiresistant Pseudomonas aeruginosa in cystic fibrosis

Ten patients with cystic fibrosis (CF) and chronic broncho-pulmonary Pseudomonas aeruginosa infection were given imipenem/cilastatin (100 mg/kg/day) in combination with tobramycin (15 mg/kg/day). Forced vital capacity and forced expiratory volume in the first second improved significantly in nine out of ten patients, and most of the patients improved clinically. P. aeruginosa was not eradicated in any patient and resistance against imipenem developed in all patients during treatment. A concomitant increase in MIC of piperacillin and ceftazidime occurred during treatment. In-vitro bactericidal synergy of imipenem and tobramycin was noted in 57% of pretreatment isolates. Seven patients complained of adverse reactions, mainly gastrointestinal, and treatment of three patients was discontinued after 5, 8, and 12 days of therapy, because of rash or nausea and vomiting. The side effects were considered to be due to imipenem/cilastatin. Because of the rapid development of imipenem resistance despite combination therapy, the high proportion of side effects, and the risk of induction of beta-lactam resistance, imipenem/cilastatin cannot be recommended for routine treatment of CF-patients with P. aeruginosa infection.

The quantitative estimation of diphtheria and tetanus toxoids. 1. The flocculation test and the Lf-unit

Considerable confusion exist in the quantitative estimation of diphtheria and tetanus toxoids. The present paper is the first in a series of papers comparing various quantitative methods. It describes the flocculation test, gives a mathematical model for the three-dimensional reaction surface, and suggests different designs which facilitate the unbiased calculation of the end-point.

Experimental infection with Streptococcus pneumoniae in mice: correlation of in vitro activity and pharmacokinetic parameters with in vivo effect for 14 cephalosporins

A mouse model using intraperitoneal inoculation of Streptococcus pneumoniae type 3 was used to compare in vitro and in vivo effects of 14 cephalosporins, selected to encompass a wide range of minimal inhibitory concentrations (MICs) against the organism. Antibiotics were subcutaneously administered as single doses 1 hr after inoculation of pneumococci, and the effect was measured as the 50% effective dose (ED50). The correlation between log ED50 and log MIC was highly significant (r = .87, P less than .001). Pharmacokinetic properties of the cephalosporins were estimated after a fixed dose of 5 mg per mouse (167 mg/kg) for all drugs. The only correlation that was significant was between log ED50 and the time the serum concentration remained above the MIC for each drug (r = -.90, P less than .001). Ceftriaxone was the most-effective cephalosporin in vivo because of a combination of high in vitro activity and prolonged serum elimination half-life.

Relationship between penicillinase production and the in-vitro activity of methicillin, oxacillin, cloxacillin, dicloxacillin, flucloxacillin, and cephalothin against strains of Staphylococcus aureus of different phage patterns and penicillinase activity

A total of 157 strains of Staphylococcus aureus of different phage patterns and penicillinase production were investigated for their susceptibility to methicillin, oxacillin, cloxacillin, dicloxacillin, flucloxacillin and cephalothin by an agar dilution method. Only strains of the 52, 52A, 80, 81 complex had significantly higher IC-50 values than the rest of the strains. No correlation was found between penicillinase production and the IC-50 values. Penicillinase susceptibility divided the antibiotics into two groups: one including methicillin, oxacillin and cephalothin, and the other included dicloxacillin, cloxacillin and flucloxacillin. Nineteen strains of S. aureus which existed in both a penicillinase producing and a penicillinase non-producing form were examined for susceptibility to the six antibiotics. The difference between penicillinase positive and penicillinase negative variants was especially marked for flucloxacillin and cephalothin. Methicillin induction prior to susceptibility testing had only a minor influence on the results. Investigation of the stability of methicillin and the four isoxazolyl penicillins against penicillinase production by 37 strains of S. aureus showed methicillin to be the most stable antibiotic. This was followed by dicloxacillin, cloxacillin, flucloxacillin, and oxacillin in that order. The order of stability was identical and independent of phage pattern and quantitative penicillinase production.

An evaluation of the polyacrylamide gel electrophoresis fractionation method for the production of Mycobacterium tuberculosis skin test preparations. II. Comparative skin testing on guinea-pigs

As part of a cooperative inter-laboratory WHO supported project for the fractionation of Mycobacterium tuberculosis skin test preparations, four fractions (designated 15, 7, 4.75 and 3.5%) were evaluated by comparative skin tests on sensitized guinea-pigs. The 7% fraction was the most potent in both homologously and heterologously sensitized animals, and the 4.75% and 3.5% gel fractions showed the lowest activity. Significant levels of cross-reactivity in guinea-pigs immunized with M. bovis BCG, M. kansasii, M. avium and M. intracellulare were demonstrated for all fractions examined, thus reflecting the antigenic relationships among these mycobacteria. These four fractions may qualify as starting material for further studies aiming at a reduction of skin test cross-reactivity.

ELISA for the routine determination of antitoxic immunity to tetanus

Serum samples from 727 persons with different vaccination histories were assessed for tetanus antitoxin content in an enzyme linked immunosorbent assay (ELISA) and tested for tetanus toxin neutralization activity in mice in order to compare the results obtained by the two methods. Neutralizing antibody activities in sera from individuals previously completely vaccinated correlated well with results obtained by ELISA and the accuracy increased with increasing antitoxin concentration in serum. This correlation was observed in sera from persons vaccinated recently as well as in sera from persons vaccinated many years ago. In sera from persons with an incomplete vaccination history ELISA was found to be an unreliable tool for the prediction of in vivo results. Many of these sera had antitoxin levels by ELISA far above the in vivo values, probably due to the presence of non specific or low avidity antitoxin which is detected in ELISA. The lowest ELISA value reliably predictive of protective antibody activity in serum irrespective of vaccination history was found to be 0.16 IU/ml. It was concluded that ELISA is useful for larger population studies as an initial test, but sera with an antitoxin content below 0.16 IU/ml should also be assessed in a neutralization system.

A new method for exact measurements of visual acuity. Determination of threshold curves for the resolving power of the eye by computerized curve fitting

The paper presents a new test method for investigations of threshold curves for the resolving power of the eye and for exact measurements of visual acuity. This method measures static visual acuity within confidence limits of 9% compared to the acuity steps in Snellen notation of 33% to 50%. Furthermore, the method introduces the slope of the threshold curve as a parameter of suggested importance in the judgement of visual capability. The test mathematic is based on a method described by Finney (1952) for calculations on dose-response curves. To calculate the results and the test statistics an iterative curve fitting programme was designed to be run on a micro-computer. By connecting the presentation system and the response panel to the same computer the test could be performed almost automatically. The new test method was used to study visual acuity measured by projected ortotypes compared to acuity when measured by printed ortotypes. Tests using projected ortotypes were found to equal traditional acuity measurements, but the test results stressed the need for perfect and adjusted optics when projecting systems are used in visual acuity test.

Comparison in sensitized and unsensitized guinea-pigs of tuberculin PPDs RT 23 and PPD-M by skin tests and lymphocyte stimulation tests. Effect of immunization time

The biological activities of tuberculin PPD RT 23 and the International Standard for Purified Protein Derivative of Mammalian Tuberculin (PPD-M) were compared in sensitized and unsensitized guinea-pigs by skin tests and lymphocyte stimulation (LS) tests. Estimates of relative potency (RP) from skin test results were dependent on the dose level, on the immunogen used, and, in guinea-pigs immunized with killed tubercle bacilli in oil, also on the immunization time. Relative potency estimates from LS results were dependent on the source of the lymphocytes and were different from estimates obtained from skin tests. Lymphocyte stimulation dose-response curves for the tuberculins were qualitatively different. In contrast to RT 23, PPD-M gave rise to non-specific skin reaction in unsensitized guinea-pigs. Both tuberculins were mitogenic to lymph node lymphocytes isolated from unsensitized guinea-pigs, PPD-M being the more mitogenic of the two tuberculins. The present results confirm that qualitatively different tuberculins cannot be unambiguously calibrated in identical terms and thus emphasize that the uncritical use of (international) standards should be avoided in tuberculin calibration.

The susceptibility of Plasmodium falciparum to sulfadoxine and pyrimethamine: correlation of in vivo and in vitro results

In 1982, 2 of 14 Plasmodium falciparum infections acquired in East Africa and diagnosed in Copenhagen were resistant to treatment with sulfadoxine plus pyrimethamine (Fansidar), while in 1983, 6 of 18 were so. The in vivo tests were supplemented by determinations of drug concentrations in serum, and 4 isolates from in vivo-sensitive cases and 6 from in vivo-resistant cases were selected for in vivo tests. These were performed in ordinary RPMI 1640 medium and in a medium with physiological p-aminobenzoic acid and folic acid concentrations. Pharmacokinetic aberrations were found to be of possible importance in only 2 of the in vivo-resistant cases. In vitro susceptibility to sulfadoxine was found to be uniformly low in all isolates. Testing with a combination of sulfadoxine and pyrimethamine in the medium with physiological concentrations of cofactors probably reflects the in vivo situation most accurately, but in all but 1 of the isolates studied in vitro the in vivo susceptibility to Fansidar would be predicted by in vitro susceptibility to pyrimethamine in either medium. The concentration of p-aminobenzoic acid in serum, quantitated by high performance liquid chromatography, was found to be subject to wide variation, and this may have implications for in vitro testing.

Influence of previous gold treatment and other patient variables on outcome of treatment with disease modifying anti-rheumatic drugs (DMARD) in patients with rheumatoid arthritis

Based on a 2-year controlled double-blind trial of levamisole, penicillamine, and azathioprine (L, P, and A), a computer aided search for predictive factors of outcome was instituted. Already at month 4 several indicators of synovitis activity were able to discriminate between patients staying in the trial for 24 months and patients whose treatment was discontinued before that time. Patients who had previously received gold therapy responded less favourably to L, P, and A than those who had not received gold. This reduction of response was more pronounced in gold resistant patients than in patients whose gold treatment had been discontinued for other reasons. The only phase protein (of several) with a predictive value was haptoglobin. If, after 4 months of treatment, haptoglobin did not normalize, this finding indicated a lack of response to treatment or a deterioration of synovitis activity during the following 4 months. The response to treatment was not influenced by HLA-types, sex, age, or clinical synovitis, disease duration, functional or anatomical aberrations at the start of treatment. The shape of the response curve as reflected by means of monthly measurements of serum-albumin and ESR was not related to disease duration, HLA-types, or previous gold treatment.

Imipenem/cilastatin treatment of multiresistant Pseudomonas aeruginosa lung infection in cystic fibrosis

Ten patients with cystic fibrosis and chronic broncho-pulmonary Pseudomonas aeruginosa infection received 45 mg imipenem/cilastatin per kg body weight/day, intravenously for two weeks. The treatment was safe with only minor side effects and clinical parameters improved considerably during therapy. In all patients resistance of Ps. aeruginosa to imipenem developed in the second week of treatment; in seven patients the therapy selected for a resistant strain and in three resistance developed in the original strain. The resistance persisted after cessation of treatment and thus the clinical usefulness of imipenem/cilastatin as monotherapy in CF-patients with Ps. aeruginosa seems to be limited.

A prospective study of lung disease caused by Mycobacterium avium/Mycobacterium intracellulare

This is a prospective study of 36 patients with lung infections caused by M. avium/M. intracellulare. The division of the patients into 2 prognostic groups ("good"/"others"), and the guidelines for their treatment are based on a previous report (3). The criteria for the division were co-existing lung disease and dyspnoea on admittance. The patients in group "good" were treated with isoniazid, rifampicin and ethambutol, in group "others" these were supplemented with one or more drugs. As in the previous study (3), the prognosis was far better for group "good" than for group "others". The patients in group "good" should be treated with isoniazid, rifampicin and ethambutol, unless the course of disease is unsatisfactory. The mortality was high in group "others" and half of the deaths were related to mycobacteriosis. Some patients became culture negative and others showed decreasing numbers of bacteria, but the value of the supplementary drugs could not be proven.

In vivo and in vitro boosting effects of tuberculin skin tests in guinea-pigs immunized with living BCG or with killed Mycobacterium tuberculosis

Eight weeks after the onset of immunization with living BCG vaccine or with heat-killed, dried Mycobacterium tuberculosis in paraffin oil (TB), guinea-pigs were skin tested with small doses of tuberculin PPD. Three weeks later the effect of these tests on skin reactions and on lymphocyte transformation (LT) responses of lymph node lymphocytes (LNL) or peripheral blood lymphocytes (PBL) was estimated by a comparison with non-tested groups. For both immunogens, the skin test after 8 weeks significantly enhanced skin reactions, particularly to low tuberculin doses. In the BCG-vaccinated guinea-pigs the LT responses of both cell types were significantly enhanced by the skin test after 8 weeks, whereas the LT responses from the TB-immunized guinea-pigs were not affected. Therefore, in the planning and interpretation of in vitro tests of cellular immunity, possible effects from previously applied skin tests should be taken into consideration.

Antigen specific in vitro activity of lymphocyte subpopulations from Mantoux positive and negative subjects assessed by lymphocyte proliferation assay

A micromethod for the lymphocyte proliferative assay and multifactorial analysis of stimulation indices classified according to subjects, lymphocyte combinations and antigens was used to elucidate deficient Mantoux (Mx) reactions in BCG-vaccinated subjects. It was possible to group each of the factors so that interactions between the two latter factors were not present within but only between groups. Comparisons between the subject groups showed a clear association between results of this in vitro test with PPD antigen and the Mx test carried out with 1 TU. The in vitro test had the advantage of being more sensitive and of not introducing the immune reactions occasionally seen with the Mx test. Thymus-processed lymphocytes were the cells responsible with functions both as effector and regulator cells, B lymphocytes had only regulatory properties.

Studies on the development of tuberculin sensitivity in immunized guinea pigs with demonstration of a close relationship between results of skin tests and the lymphocyte transformation technique

The development of tuberculin sensitivity in groups of guinea pigs immunized with living BCG vaccine or with heat-killed Mycobacterium tuberculosis suspended in oil (TB) was measured by skin tests and lymphocyte transformation (LT) tests with tuberculin PPD. LT tests on lymphocytes from peripheral blood (PBL) and lymph nodes (LNL) and skin tests were carried out on different groups of guinea pigs for 1 year following immunization. Three ways of expressing the LT results were considered, i.e. as stimulation index, delta cpm and uncorrected cpm values. Since neither of the first two methods were equally applicable to all of the data, we decided to express the data as geometric means of cpm values for stimulated and control cultures, respectively. For both immunogens the sensitivity measured by PBL LT and skin tests showed a closely parallel development; LNL reactivity appeared earlier and remained at a higher level than PBL reactivity. Antibody levels in the guinea pigs were measured using a radioimmunoassay technique, were found to be dependent on the immunization period and not correlated to the cellular immunity.

Effect of 2-mercaptoethanol and mycostatin on guinea pig lymphocyte transformation: interpretation of results depends on the method of calculation

The stimulating effects of 2-mercaptoethanol (2-ME) reported in murine cell cultures were confirmed for guinea pig lymphocyte transformation (LT). 2-ME was mitogenic for peripheral blood lymphocytes (PBL) and lymph node lymphocytes (LNL) and enhanced PPD-induced LT. The effect on LNL was dependent on the magnitude of the response of non-2-ME treated cultures. The 2-ME effect on PPD-stimulated LNL was reversed when stimulation index (SI) replaced the delta cpm estimate. Mycostatin (MYC) inhibited the blastogenic response of PBL control cultures, whereas its effect on LNL control cultures varied. The interpretation of the effect of MYC on PPD-stimulated cultures was dependent on the use of the delta cpm or SI estimates. The interpretation of LT experiments is therefore highly dependent on whether delta cpm or SI is used for expression of results. Analysis of effects on control and stimulated cultures should precede the addition of 2-ME or MYC to cultures for LT.

Kinetics and dose calculations of ampicillin and gentamicin given as continuous intravenous infusion during parenteral nutrition in 88 newborn infants

Ampicillin and gentamicin were administered continuously intravenously to 88 newborn infants using individually calculated dosages. For infants with a mean value of plasma clearance of the antibiotics, it was calculated that the serum ampicillin and gentamicin concentrations would be between 35-55 and 3-5 micrograms/ml, respectively, using the dosages for intermittent treatment. These dosages are therefore recommended as fixed dosages for continuous intravenous infusion initiated by a bolus dosage. Serum gentamicin concentration should be assayed about three half-lives after start of infusion and the dosage adjusted for values outside 3-5 micrograms/ml.

Predicting recurrence in patients with breast cancer from cumulative laboratory results: a new technique for the application of time series analysis

We followed the cases of 26 consecutive postmenopausal patients operated on for primary breast cancer. Serum specimens were obtained each month for 1.5 years and stored at -80 degrees C until assayed for carcinoembryonic antigen (CEA) and other quantities. Ten patients developed recurrence, while 16 qualified as controls (no clinical recurrence for at least 1.7 years after the last venipuncture). Using the homeostatic autoregressive time series model, modified by us to be particularly sensitive to sustained deviations from the mean, we detected four recurrences by CEA without having any falsely positive alarms. Group-based reference limits and application of the unmodified homeostatic model were less effective (fewer detected and shorter lead time). Simulation studies, involving use of a mathematical model relating CEA concentration to tumor growth and using parameters estimated from patient data, verified this and indicated that at least five stable baseline values are needed to detect 100% of recurrences before they are detected by the group-based limit.

Predicting recurrence in patients with breast cancer from cumulative laboratory results: a new technique for the application of time series analysis

We followed the cases of 26 consecutive postmenopausal patients operated on for primary breast cancer. Serum specimens were obtained each month for 1.5 years and stored at -80 degrees C until assayed for carcinoembryonic antigen (CEA) and other quantities. Ten patients developed recurrence, while 16 qualified as controls (no clinical recurrence for at least 1.7 years after the last venipuncture). Using the homeostatic autoregressive time series model, modified by us to be particularly sensitive to sustained deviations from the mean, we detected four recurrences by CEA without having any falsely positive alarms. Group-based reference limits and application of the unmodified homeostatic model were less effective (fewer detected and shorter lead time). Simulation studies, involving use of a mathematical model relating CEA concentration to tumor growth and using parameters estimated from patient data, verified this and indicated that at least five stable baseline values are needed to detect 100% of recurrences before they are detected by the group-based limit.

A study of bacteremias in Denmark from 1977-1978

The results of blood cultures from a large number of Danish hospitals examined at Statens Seruminstitut in 1977 and 1978 have been analysed. Out of a total of 17, 518 cultures in 1977 and 17,820 in 1978, 1,626 from 830 patients and 1,544 from 832 patients yielded growth of pathogenic microorganisms. Cases of bacteremia with Enterobacteriaceae constituted approximately 50% of cases both in 1977 and 1978. Polymicrobial bacteremia occurred in 8.1% of bacteremic cases in 1977 and 7.5% of those in 1978. The microorganisms isolated and their frequencies were surprisingly similar to those found in 1965 and 1971 in an earlier investigation from this department. No change in antibiotic susceptibility was observed between 1977 and 1978. Retesting of 50 E. coli strains from 1965, 1971 and 1978 for susceptibility towards ampicillin, cephalotin, streptomycin and tetracycline indicated that no significant changes had occurred, contrary to the results of the earlier investigation. This fact stresses the importance of exploring the possibility of unnoticed methodological changes having occurred in the sensitivity testing systems before any conclusions can be drawn concerning apparent differences in antibiotic susceptibilities.

Loss of Treponema pallidum during incubation in Nelson's survival medium with or without serum added

Treponema pallidum organisms suspended in equal parts of Nelson's survival medium alone and with addition of various sera were counted in 5 microliters samples before and after 18 hours' anaerobic incubation at 35 degrees C. Samples in which the treponemes were not Poisson-distributed were excluded from the study. A loss of greater than 30% occurred in 230 out of 391 samples. The disappearance of treponemes did not seem to be caused by treponemal agglutination during incubation. There was no adherence of treponemes to the formed elements remaining in the suspension. The loss was not dependent on the concentration of syphilitic serum, nor was it influenced by the presence of immobilizing antibody in the serum. Lack of rigorous anaerobiosis during the manipulations did not influence the treponemal loss. The loss was independent of the density of the treponemal suspensions which did not contain unheated guinea-pig serum (GPS). The relative frequency of the loss exceeding 30% was highest in suspensions containing unheated GPS. However, the extent of loss in individual samples was haphazardly distributed among suspensions of all the compositions examined. The loss of treponemes seems to depend on at least two factors: a) a factor which is eluted together with the treponemes from the syphilitic orchitis and b) the presence of active guinea-pig complement. It is conjectured that the complement is non-immunologically activated and acts through the alternative pathway.

Statistical evaluation of the lymphocyte proliferation assay with non-stimulated cultures

A micromethod for the lymphoproliferative assay has been evaluated statistically with non-stimulated human lymphocyte combinations. Different variance components were estimated by means of a hierarchical analysis of variance. Instead of using an arbitrary value for a significant difference between stimulated and non-stimulated cultures, the value can be calculated on the basis of the components of variance in the experimental design. The method disclosed systematic differences between the values of control cultures depending on the lymphocyte combinations and groups of persons examined, which underlines that every experiment should always contain non-stimulated cultures. Further, cell-cell cooperation and differences in spontaneous DNA synthesis within individual lymphocyte populations could be demonstrated.

In vitro comparison of gentamicin and netilmicin including a regression line for netilmicin

The results of two different in vitro investigations are presented: a comparison between gentamicin and netilmicin and a presentation of a regression line for netilmicin. The first investigation comprises 335 bacterial strains. The method used is a plate dilution technique and the susceptibility of the strains is given as IC50 values, i.e. 50% inhibiting concentrations. The conclusion of the study is that netilmicin offers no advantage over gentamicin. In the second investigation a regression line is presented giving the relation between IC50 values for netilmicin and the size of the inhibition zone, based upon 109 bacterial strains. For the disc diffusion method a 20-hour prediffusion technique is used. The disc content is 15 micrograms netilmicin base. The results are discussed and a grouping as to susceptibility is proposed based on the IC50 values found and the blood level obtained after scheduled dose of netilmicin.

Quantitative microbiological assay of thiomersal using agar diffusion from paper discs

A quantitative assay method for determination of thiomersal in biological products is described and evaluated. A microbiological method using agar diffusion from filter paper discs is used. The advantages of the method in terms of low cost and reliability for determining the actual antimicrobial activity in the preparation are discussed. The assay method is in routine use in the production control of vaccines at our Institute.

Minimum variability in the need for care in geriatric institutions

Based on an account of the need for nursing care in the entire patient population in De Gamles By, Copenhagen, on January 15, 1967, and again on January 15, 1969, it is shown that the need for care varies considerably, despite a policy of admitting only independent persons. The consequences of this variability for the size of the nursing staff required are discussed, together with some aspects of admittance policy.

Some aspects concerning admittance to and accommodation in geriatric institutions housing persons with varying degrees of need for care

On the basis of an account of the mortality and changes in the need for care over a 2-year period among independent persons and patients requiring care in De Gamles By, Copenhagen, an assessment is made of the movements of patients and the need for care in a model of a geriatric institution. This model includes both purpose-built residential apartments for independent persons and places for dependent patients requiring nursing care. It is shown that the accommodation for the latter patients rapidly becomes occupied by the independent persons from the residential apartments who subsequently need nursing care. Thus, the places in the nursing section are blocked for the admittance of dependent persons living in the community outside. This situation arises when there are equal numbers of both types of accomodation. Where the number of residential apartments is greater than the number of places in the nursing section the care function must be transferred to the residential apartments, and this is regarded as impracticable.

Deoxyribonucleic acid hybridization between different species of mycobacteria

The homology percentages between DNA from M. smegmatis ATCC 607 and DNA from nine various species of mycobacteria have been determined. DNA-DNA hybridization was measured in a spectrophotometer. The technique, calculation of results and the uncertainty of the method are described.

Prognosis of survival in a geriatric population

With the aim of demonstrating prognostics as regards death in a geriatric population, the mortality among 1 486 patients (516 men and 970 women) in De Gamles By, Copenhagen, was observed over a 2-year period. The mortality curves for the groups examined were found to be rectilinear in logarithmic form and could therefore be described with sufficient certainty by one value, viz. the probability of death in any one year. The probability of death was just over 20% and was the same for both sexes. Of the parameters examined, particularly high mortality was found where there was urinary incontinence, severe mental abnormality, a great need for nursing, and poor physical mobility (especially inability to walk). On the other hand, there was no particular relationship with age. Where the degree of the handicapping factors was severe, there was generally greater mortality among the men than among the women, but this was not so in the less severe cases. The length of stay in the institution had no effect on the mortality. The results of the present study are in good agreement with previous findings reported from New York (7).

Minimum need for care in geriatric institutions

On the basis of a study from De Gamles By, Copenhagen, concerning the mortality and changes in the patients' need for nursing care over a 2-year period, calculation is made of the time-related changes in the care status, using a special model for homes for elderly persons. This model is based on a policy that only independent persons are received into such homes and that they remain there until they die. It is found that the need for care becomes stabilized after a period of 5-6 years and remains at a level corresponding to about 45% independent, 36% slightly dependent, and 17% heavily dependent patients (the "minimum need for care"). Using the model, a few examples are given to illustrate the changes which would arise in the need for care in De Gamles By if, on the basis of the primary care status on January 15, 1969, (A) only independent patients were admitted, and (B) the current admittance policy was continued.

Antibiotic policy and spread of Staphylococcus aureus strains in Danish hospitals, 1969-1974

In the period 1969-1974 a decreasing number of Danish hospital departments recorded epidemic occurrences of Staphylococcus aureus strains, and the local spread of strains was less extensive. Multiple-resistant strains of the 83 A complex were succeeded by type 94 strains, resistant to penicillin only. The level of methicillin resistance fell from 19 to 6%. 12% of methicillin resistant strains are now sensitive to streptomycin and/or tetracyclines; they do not represent a few clones, but belong to a wide spectrum of phage types. The changes follow a reduction in the consumption of streptomycin and tetracyclines not of methicillin or other penicillins. As a contrast to the general reduction of combined resistance to streptomycin and tetracyclines, the strains in dermatological departments, where tetracyclines are commonly used, maintain a high degree of resistance to tetracyclines alone.

Staphylococcus aureus strains isolated in Danish hospitals from January 1st, 1966, to December 31st, 1974

During the years 1966-1974, 167,297 strains isolated from 167,297 patients or staff members in Danish hospitals were registered at Staten Seruminstitu. All the strains were phage-typed and examined for production of a 'Tween'-80-splitting enzyme and resistance to mercuric chloride. 158,236 strains were examined for resistance to antibiotics. Since 1968, a steep decrease in the number of strains resistant to three or more antibiotics (multiple-resistant) and in strains of the 83A complex was noticed. In recent years an increase in strains belonging to phage-group I and in those referred to as miscellaneous and non-identified was registered. The increase in the non-typable strains might be explained by the shift of the concentration of the typing phages from 1000 X RTD to 100 X RTD. It is concluded that at least two factors may have contributed to the reduction of the multiple-resistant strains: an altered antibiotic policy, restricting the use of streptomycin and tetracyclines, and an improved hospital hygiene, diminishing the spread of identical strains within the various departments. However, it is emphasized that the consumption of methicillin is still increasing.

Epidemics of Mycoplasma pneumoniae infection in Denmark from 1958 to 1974

The study is a retrospective and prospective serological investigation of the incidence of Mycoplasma (M.) pneumoniae infection in Denmark during a 17-year period. By least square multiple regression analysis it was shown that four major outbreaks or epidemics had occurred which culminated at regular intervals of four and a half years. The study was based on cold agglutinin (CA) positive sera tested for antibodies to M. pneumoniae by an indirect immunofluorescence (IF) test, an indirect haemagglutination (IHA) test or a complement fixation (CF) test. By the criteria chosen for a positive test, the CF test was found to detect more cases than the IF or IHA tests. A shift during the study from the latter two tests to the CF test influenced the incidence, but not the periodicity of epidemics. The consequence of including only CA positive sera in the study was investigated.

Bacterial flora in relation to cataract extraction. IV. Postoperative inflammation. The role of conjunctival bacteria and certain surgical factors

In 499 patients operated on for cataract, the clinical postoperative signs of extraocular inflammation (conjunctival hyperaemia, chemosis, discharge and oedema of the lids), the number of infiltrates around the corneoscleral sutures, and the severity of intraocular inflammation in the anterior chamber (aqueous-flare) were assessed on the fourth postoperative day and correlated with the bacterial conjunctival flora examined both qualitatively and quantitatively on the same day. Patients with potential pathogens (Staphylococcus aureus, gram-negative bacilli and streptococci) on the conjunctiva following operation did not show any increased inflammatory reactions when compared with those without such pathogen. The quantity of bacteria, i.e. number of colonies, did not appear to play a role. The reasons are discussed. The clinical postoperative inflammatory signs were further correlated with the following factors: surgical complications, quality of suturing technique, use of alpha chymotrypsin, systemic disease, sex and age. A positive correlation was found between the severity of extraocular inflammation and retained lens material and hyphaema. Furthermore, extraocular reactions were more severe in males than in females. The incidence of infiltrates around corneoscleral sutures was found to vary with age, i.e. occurred more frequently in patients less than 60 years. No relationship was found between the severity of aqueous-flare and the above mentioned factors.

Decreased delayed hypersensitivity to tuberculin demonstrated in experimental leptospirosis in guinea pigs

Skin reactivity to tuberculin has been studied during the course of experimental leptospirosis in guinea pigs. A depression of the delayed hypersensitivity to tuberculin was demonstrated in the infected animals. The depression was most pronounced when icterus had developed. The depression was not correlated with the amount of infectious units administered or with the demonstration of live leptospirae in the peritoneal cavity. In the infected animals there was no correlation between the initial and the final skin tests which is in contrast to findings in the control group.

The incidence of Mycoplasma pneumoniae infections in Denmark over the past seventeen years: a review

The variations in the incidence of Mycoplasma pneumoniae infections in Denmark over a period of 17 years could be demonstrated in the central serological laboratory which serves the whole of the population. This observation was made possible for the first and major part of this study by testing cold agglutinin (CA) positive sera, which had been kept frozen sine 1958, for antibodies to M.pneumoniae. The second part of the study is based upon results from routine tests for CA and M.pneumoniae antibodies on all samples which we receive. A statistical analysis of the total material indicates that four epidemics of M.pneumoniae antibodies on all samples which we receive. A statistical analysis of the total material indicates that four epidemics of M.pneumoniae infection had taken place from January 1958 to December 1974 and that these epidemics occurred at regular four and a half year intervals. By a follow-up of the study a fifth epidemic was demonstrated during the first eight months of 1975 which broke the regular periodicity by appearing two years earlier than expected. The consequences of including only CA positive sera in this study was investigated. Antibodies to M.pneumoniae were measured by either an indirect immunofluorescence test, an indirect haemagglutination test or a complement fixation test. The observed difference in sensitivity of these tests is discussed in relationship to a possible influence on the overall incidence.

Bacterial flora in relation to cataract extraction. III. Postoperative flora

The conjunctival flora of 499 patients operated for cataract was studied on the 4th and 7th postoperative days and compared with the flora examined previously on admission to the hospital and at the time of surgery (Fahmy et al. 1975b, c). Antibiotics had been administered approximately 18 hours before operation, at the conclusion of surgery, and then on the 4th postoperative day after the cultures had been taken. After a significant fall in incidence, including all kinds of bacteria at the time of surgery (Fahmy et al. 1975c), Staphylococcus albus showed an increase in incidence on the 4th postoperative day to the level found on admission. Corynebacteria and gram-negative bacilli likewise showed increasing incidence but not to the level of admission. The incidence of Staphylococcus aureus and streptococci remained unchanged. On the 7th postoperative day, S. aureus showed a fall in incidence while other bacteria had largely the same incidence as that of the 4th postoperative day. The origin of S. aureus isolated postoperatively from the conjunctiva was studied, and showed that the great majority of strains were similar to those found on the patient's own conjunctiva preoperatively. In a few instances, S. aureus could be traced to the patient's own nose or to the noses of some of the nurses. The air of the wards, eye drops or ophthalmic ointments used in the treatment of the patients apparently did not play any role as a source of S. aureus infection. Cultures obtained on the 4th postoperative day showed only a minor relationship to the flora of the wound site observed at the conclusion of surgery.

Bacterial flora in relation to cataract extraction. II. Peroperative flora

The peroperative flora of 499 patients undergoing cataract extraction was studied with local bacterial cultures taken at the beginning and end of surgery and compared with the preoperative flora examined previously (Fahmy et al. 1975 b) on admission the day prior to surgery. The local application of a single dose of oxytetracycline - polymyxin B, approximately 18 hours before surgery, significantly reduced the incidence of bacteria at the time of surgery. However, 92% of the conjunctivas examined immediately before operation proved to harbour one or more kinds of microorganisms. Futhermore, 61% of the wound sites were found to be contaminated with bacteria at the conclusion of surgery. The reasons are discussed. The origin of Staphylococcus aureus isolated peroperatively from the conjunctiva and wound site was studied. The great majority of strains could be traced to the patient's own conjunctiva preoperatively. In a few cases S. aureus was traced to the patient's own nose, skin of face or to the surgeon's nose. The air of the wards and operating theatre as well as the hands and gloves of surgeons and assistant nurses apparently did not play any role as a source of S. aureus infection.

Bacterial flora in relation to cataract extraction. I. Material, methods and preoperative flora

The conjunctival flora of 499 patients was studied the day before cataract extraction, no antibiotics or chemotherapeutical agents had been used before admission. Staphylococcus albus was by far the most common micro-organism (95.4%), followed by corynebacteria (44%), Staphylococcus aureus (14.9%), gram-negative bacilli (7.8%) and pneumo-streptococci (4.4%). Corynebacteria was isolated more frequently in the presence of S. albus, while S. aureus and gram-negative bacilli were found more frequently in the absence of S. albus. No relationship could be demonstrated between the occurrence of pneumo-streptococci and S. albus. The flora of the nose and skin of the face were studied and compared with the conjunctival flora, and a similarity could be observed. Furthermore, strains of S. aureus isolated at the same time from the two or three regions, in most cases, showed the same bacterio-phage type complex. The conjunctival flora was further correlated with sex, age, season, and number of polymorphonuclear neutrophils recovered from the conjunctival fluid. The incidence of corynebacteria and gram-negative bacilli was found to be higher in males, while corynebacteria was the only organism to show seasonal variation, i.e. was isolated more frequently in the second and third quarters of the year. No correlation could be found between age or number of neutrophils.

Bacterial flora of the normal conjunctiva. II. Methods of obtaining cultures

The methods used for obtaining bacterial cultures from the normal conjunctiva were reviewed. A comparison was made between four methods; a) platinum loop, b)calcium alginate swab c) dry, and d) wet cotton wool swab, using agar (all methods) and serum-bouillon (methods b, c, d) as culture media. The comparisons were based on the isolation rate of Staphylococcus albus and corynebacteria. At the same time, four topical anaesthetics (benoxinate, tetracaine, proparacaine, cocaine) and one vital stain (tetrazolium - alcian blue mixture) instilled into the conjunctiva immediately before taking samples, were studied for their effects on the isolation rate of Staphylococcus albus and corynebacteria. For isolating Staphylococcus albus, method d was found to be superior to the others when the methods were used in the above mentioned order, and when agar was the only culture medium used. On the other hand, after instillation of the above mentioned eyedrops, causing the so-called "washing-out" effect (Fahmy et al. 1974), method a was found better than the others, providing the methods were used in the a-b-c-d order and when agar only was used. When considering the growth of Staphylococcus albus in serum boullion as well, methods b, c, and d were found equal in effect, but somewhat superior to a. Corynebacteria showed nearly the same isolation rate with all the methods before as well as after the instillation of eye drops.