Search for agents causing atypical pneumonia in HIV-positive patients by inhibitor-controlled PCR assays

Pneumonia is one of the most frequent complications in acquired immunodeficiency syndrome-patients with Pneumocystis carinii as the leading cause. The true prevalence of atypical agents such as Chlamydia pneumoniae, C. trachomatis, Legionella pneumophila and Mycoplasma pneumoniae in this population of patients is unknown as the currently used method for diagnosing these agents is measurement of antibody levels. However, this method is of limited value in human immunodeficiency virus (HIV)-positive patients who may have a compromised antibody response. To evaluate the prevalence of Chlamydia spp., Legionella spp. and M. pneumoniae in HIV-infected patients with pulmonary disease, this retrospective study has applied inhibitor-controlled polymerase chain reaction analyses on 103 bronchoalveolar lavage (BAL) fluids representing 103 episodes of pneumonia in 83 HIV-positive patients. L. pneumophila was detected in 1% of the BAL fluids and M. pneumoniae was found as a coexisting pathogen in 2% of the samples. Chlamydia spp. could not be detected in any of the BAL fluids. By culture and staining methods 106 other microorganisms were detected with P. carinii and Streptococcus pneumoniae as the most frequently occurring. Pneumonia due to Chlamydia pneumoniae, Legionella pneumophila or Mycoplasma pneumoniae seems to be rare in Danish human immunodeficiency virus-infected patients, but might be considered as a possible cause in cases of treatment failure.

Prevalence of positive urinary dipstick analysis (leucocyte esterase, nitrite, haemoglobin, or glucose) in a population of 3645 adult subjects--consequence for measurement of urinary albumin excretion rate

OBJECTIVES

To assess prevalence of positive urinary dipstick analysis for leucocyte esterase, nitrite, haemoglobin, or glucose in the general population and measure the urinary albumin excretion rate (UAER) in subjects with or without a positive dipstick analysis.

DESIGN

A cross-sectional study of 3645 subjects.

SETTING

An unselected urban population study.

MAIN OUTCOME MEASURES

Prevalence data of positive dipstick analyses and UAER values.

RESULTS

Prevalence data of a positive dipstick analysis were 12%, 4%, 3% and 6%, respectively, for leucocyte esterase, nitrite, haemoglobin, and glucose. Subjects with any positive dipstick analysis had significantly higher UAER than subjects with a negative analysis: 4.9 (4.4-5.3) (geometric mean (95% confidence interval)) vs 3.0 (2.9-3.1) mg 24 h(-1) (p < 0.001).

CONCLUSIONS

Prevalence data of positive urinary dipstick analyses in a large population based study are provided. Subjects with any positive finding had higher UAER than controls. Exclusion of subjects with a positive finding is recommended in studies of UAER as a cardiovascular risk factor in non-diabetic subjects.

Detection of Ureaplasma urealyticum by PCR and biovar determination by liquid hybridization

An assay which combines the direct detection of Ureaplasma urealyticum with biovar determination was developed and applied to 618 urogenital specimens. U. urealyticum was detected by inhibitor-controlled PCR. A 429-bp fragment of the urease gene was amplified. The amplicons were labelled with digoxigenin during PCR. Biovar determination was performed by liquid hybridization with biotin-labelled biovar-specific probes, and the hybrids were detected with peroxidase-conjugated sheep anti-digoxigenin immunoglobulin G Fab fragments. Results of PCR and culture for 453 urogenital specimens from women and 105 urethral specimens from men could be compared. Among the specimens from women, 63% were PCR positive as well as culture positive, 0.9% were positive only by PCR, and 4% were positive only by culture. Among the specimens from men, 15% were PCR positive as well as culture positive, 1% were positive only by PCR, and 9% were positive only by culture. By using culture as the reference method, the PCR had a sensitivity of 94% and a specificity of 98% when applied to specimens from women and a sensitivity of 64% and a specificity of 99% when applied to specimens from men. Overall, 80% of the PCR-positive specimens contained biovar 1,13.5% contained biovar 2, and 6.5% contained both biovars.

Urinary albumin excretion in hospitalized patients with acute myocardial infarction. Prevalence of microalbuminuria and correlation to left ventricle wall thickness

Microalbuminuria, a subclinical rise in the urinary albumin excretion, is a risk indicator of atherosclerotic cardiovascular disease. The aim of this study was to measure the urinary albumin excretion in patients with acute myocardial infarction, and to correlate this with known atherosclerotic risk factors. One-hundred-and-twenty-six patients and 56 healthy controls matched for age and sex were studied. The albumin/creatinine concentration ratio in morning urine specimens was calculated as an index of the albumin excretion. Microalbuminuria was defined as a urinary albumin/creatinine concentration ratio above 1 mg/mmol. Urinary albumin excretion (0.88 [95% confidence interval 0.69-1.11] versus 0.51 [0.40-0.63] mg/mmol; p = 0.001) and frequency of microalbuminuria (33 [95% confidence interval 25-41] versus 16 [9-23]%; p = 0.03) were higher in patients than controls. This difference was independent of blood pressure, body weight, smoking, diabetes mellitus, renal disease, and thrombolytic treatment. There was a positive correlation between urinary albumin excretion and thickness of the left ventricle wall (R = 0.28; p = 0.001) which was independent of blood pressure. Follow-up examination of the patients will reveal whether microalbuminuria increases the risk for recurrence of acute myocardial infarction.

Ambulatory blood pressure and urinary albumin excretion in clinically healthy subjects

A slightly elevated urinary albumin excretion rate (UAER) is a predictor of atherosclerotic cardiovascular disease. The mechanism is unknown, but moderate office blood pressure elevation has been demonstrated as part of a clustering of known atherosclerotic risk factors in subjects with elevated UAER. Because 24-hour ambulatory blood pressure is a superior predictor of hypertensive target organ involvement, we aimed to investigate blood pressure profile in clinically healthy subjects with elevated UAER. Ambulatory blood pressure monitoring was performed with a portable recorder in 27 subjects with an elevated UAER (>6.6 microg/min, overnight urine collection) and 46 normoalbuminuric control subjects. Mean+/-SD systolic and diastolic ambulatory blood pressures (24-hour) were significantly higher in subjects with elevated UAER than in normoalbuminuric controls (134+/-12 versus 128+/-11 mm Hg and 78+/-7 versus 75+/-6 mm Hg, P<0.05), as were systolic and diastolic blood pressure loads [median (range): 42% (6 to 94%) versus 23% (1 to 89%) and 20% (0 to 68%) versus 6% (0 to 62%), P<0.05]. The circadian variation of blood pressure was normal in subjects with elevated UAER. However, the increased urinary loss of albumin could not be solely related to the higher blood pressure. In conclusion, apparently healthy subjects with elevated UAER had slightly but significantly higher 24-hour systolic and diastolic blood pressure levels in addition to increased blood pressure loads but normal circadian variation. The demonstrated differences in blood pressure may offer a partial explanation for the association between elevated urinary albumin excretion and atherosclerotic cardiovascular risk.

Failure to detect Chlamydia pneumoniae in calcific and degenerative arteriosclerotic aortic valves excised during open heart surgery

Chlamydia pneumoniae has been associated with atherosclerosis, although no causal association has been established. Employing culture and polymerase chain reaction in aortic valves with calcific and degenerative arteriosclerotic changes from 23 non-consecutive patients undergoing aortic valve replacement, C. pneumoniae was not detected in any of the valves. 19/22 patients had serological evidence of past infection with C. pneumoniae. Our findings do not provide supportive evidence for the hypothesis that C. pneumoniae is associated with calcific or degenerative arteriosclerotic aortic heart valve disease.

Diagnostic use of PCR for detection of Pneumocystis carinii in oral wash samples

There is a need to develop noninvasive methods for the diagnosis of Pneumocystis carinii pneumonia in patients unable to undergo bronchoscopy or induction sputum. Oral wash specimens are easily obtained, and P. carinii nucleic acid can be amplified and demonstrated by PCR. In routine clinical use, easy sample processing and single-round PCR are needed to ensure rapid analysis and to reduce the risk of contamination. We developed a single-round Touchdown PCR (TD-PCR) protocol with the ability to detect PCR inhibition in the specimen. The TD-PCR was evaluated in a routine diagnostic laboratory and was compared to a previously described PCR protocol (mitochondrial RNA) run in a research laboratory. Both PCR methods amplified a sequence of the mitochondrial rRNA gene of P. carinii. Paired bronchoalveolar lavage (BAL) and oral wash specimens from 76 consecutive human immunodeficiency virus type 1-infected persons undergoing a diagnostic bronchoscopy were included. The TD-PCR procedure was quicker than the mitochondrial PCR procedure (<24 versus 48 h) and, compared to microscopy, had sensitivity, specificity, and positive and negative predictive values of 89, 94, 93, and 91%, respectively, for oral wash specimens and 100, 91, 90, and 100%, respectively, for BAL specimens. Our results suggest that oral wash specimens are a potential noninvasive method to obtain a diagnostic specimen during P. carinii pneumonia infection and that it can be applied in a routine diagnostic laboratory.

An outbreak of Pontiac fever among children following use of a whirlpool

We investigated an outbreak of fever, most likely due to a contaminated whirlpool, among nine adults and six children residing in a summerhouse. The outbreak was characterized by a high attack rate, short incubation periods, influenza-like symptoms, and rapid recoveries, all features typical of Pontiac fever. However, the children had less-characteristic symptoms than the adults, and they did not have any sequelae. Findings on the children's chest radiographs were unremarkable, and none of the children had leukocytosis. Evidence of Legionella pneumophila infection was found in six cases: in one case by isolation of L. pneumophila serogroup 1 and detection of legionellae by PCR, and in five cases by seroconversion to the clinical isolate. Six additional cases had presumptive evidence of legionella infection, with seroconversion to Legionella micdadei antigen; a PCR assay was also positive for legionellae for one of these cases. In contrast, two adult nonusers of the whirlpool had no symptoms and no serological evidence of infection. Serological testing and cultures for other pathogens, as well as cultures of all environmental samples, were negative. This investigation demonstrates the differences between adults and children with respect to the clinical picture of Pontiac fever; furthermore, it shows that culture and PCR assay of tracheal aspirates for legionellae can be performed in a hospital setting for rapid diagnosis, although the sensitivities of these methods are low.

Diagnosis of Mycoplasma pneumoniae infection in autopsy and open-lung biopsy tissues by nested PCR

A nested PCR specific for the Mycoplasma pneumoniae P1 gene was used to diagnose mycoplasma infection in two cohort patients with severe pneumonia within 24 h of tissue receipt. A postmortem diagnosis of M. pneumoniae infection was obtained for the first patient, who died without the collection of appropriate paired samples for serodiagnosis. An open-lung biopsy obtained from the second patient allowed a quick, definitive diagnosis and proper selection of therapy.

Chlamydia pneumoniae in children with otitis media

In this study the polymerase chain reaction was used to test for the presence of Chlamydia pneumoniae DNA in 118 middle-ear aspirates from 20 children with acute otitis media (AOM) and 53 children with otitis media with effusion (OME). C. pneumoniae was detected in 8 samples obtained from 5 children with OME and, together with Streptococcus pneumoniae, in a sample from 1 child with AOM. The mean age of these five children (6.6 +/- 1.4 years) was significantly higher than that of the 48 children with OME in whom C. pneumoniae could not be detected (4.3 +/- 1.9 years). The presence of C. pneumoniae in 9.4% of the examined children with OME suggests that C. pneumoniae might be a significant supplementary factor in the etiology of this common children's disease.

Microalbuminuria and its relation to cardiovascular disease and risk factors. A population-based study of 1254 hypertensive individuals

Microalbuminuria has been proposed as a potential atherosclerotic risk factor in hypertensive individuals. The aim of this cross-sectional population study was to analyse whether microalbuminuria is related to a higher prevalence of cardiovascular disease, and a more atherogenic risk profile, and reversely related to the use of antihypertensive drugs. In a major health screening at the State University Hospital in Copenhagen, including urinary albumin excretion, glomerular filtration rate, blood pressure (BP), electrocardiogram, body mass index, plasma lipoproteins, fibrinogen, and albumin, and information regarding a history of acute myocardial infarction, smoking, and antihypertensive drugs, 1254 participants without diabetes mellitus or renal/urinary tract disease had arterial hypertension. Age range was 30-70 years. Microalbuminuria (nocturnal urinary albumin excretion >15 microg/min) occurred in 5%, and cardiovascular disease (previous acute myocardial infarction or electrocardiographic Q-waves) also in 5% of the study population. Microalbuminuric hypertensive subjects were characterized by higher age and systolic BP, and a male predominance, as compared to normoalbuminuric hypertensive subjects. The frequency of cardiovascular disease was similar in the two groups. In contrast, when analysed as a continuous variable, a one unit increase in the logarithmically transformed urinary albumin excretion significantly increased the likelihood of cardiovascular disease (odds ratio [95% confidence interval] 1.32 (1.02-1.70); P < 0.05), and this relation was independent of age, sex, and conventional atherosclerotic risk factors. Participants who were effectively treated with antihypertensive drugs did not have a lower urinary albumin excretion than insufficiently treated or untreated participants. It is concluded that slightly elevated albumin excretion in the urine is not only a pressure-dependent functional phenomenon in the glomerular vessel walls, but associated with permanent atherosclerotic abnormalities in the entire vascular system.

Markers of sexually transmitted diseases in seminal fluid of male clients of female sex workers

OBJECTIVES

To screen for certain STD markers in a group of male clients of female sex workers.

METHOD

Condoms with seminal fluid were collected at 10 "massage parlours" in Copenhagen. The seminal fluid samples were examined for HIV antibodies, markers of hepatitis B virus (HBV), Chlamydia trachomatis, and Mycoplasma genitalium.

RESULTS

All samples (n = 332) were negative for HIV antibodies. Out of 327 samples examined for HBV markers 32 (9.8%) were positive for HBV core antibodies, one of which was also positive for HBV antigen. C trachomatis could be demonstrated in six out of 122 (4.9%) samples and M genitalium in one out of 122 samples.

CONCLUSIONS

The finding of a C trachomatis prevalence of 4.9% is considerable higher than expected in men with a presumed age of 35-55 years. The demonstration of a prevalence of HBV markers of 9.8% indicates that these clients have an increased risk of HBV infection, a finding that further consolidates the recommendation of HBV vaccination of sex workers. As shown in this study, STD transmission in commercial sex may also have the client as the source.

A seroepidemiological study of Mycoplasma pneumoniae infections in Denmark over the 50-year period 1946-1995

The epidemiological pattern of Mycoplasma pneumoniae infections in Denmark over the 50-year period 1946-1995 is described. The study is based on blood specimens received at the central laboratory at Statens Serum Institut for titration of cold agglutinins (CA), initially for the diagnosis of CA positive primary atypical pneumonia, and during the 1960s of M. pneumoniae infection; in addition, specimens from the last 38 years were tested for antibodies specific to M. pneumoniae. By retrospective analysis of the test results compiled over the years it was found that intervals of regular periodicity have been interrupted by an era of changes in the pattern. Attention is paid to the significance of CA for this study, and the possible background of the epidemiological pattern is described.

[Microalbuminuria as predictor of atherosclerotic cardiovascular disease in IDDM]

The aim of this follow-up study was to assess whether slightly elevated urinary albumin excretion, i.e., microalbuminuria, precedes development of atherosclerotic vascular disease in IDDM. Out of 259 IDDM-patients 30 developed vascular disease during 2,457 person-years. Microalbuminuria was significantly predictive of vascular disease (hazard ratio (95% confidence interval) 1.06 (1.02-1.18) per 5 mg/24 hours increase in urinary albumin excretion; p = 0.002). The predictive effect was independent of age, sex, blood pressure, tobacco smoking, serum concentrations of total-cholesterol, HDL-cholesterol, sialic acid, and von Willebrand factor, and of haemoglobin A1c, insulin dose, diabetes duration, and diabetic nephropathy (hazard ratio (95% confidence interval) 1.04 (1.01-1.08) per 5 mg/24 hours increase in urinary albumin excretion; p = 0.03). It is concluded that slightly elevated urinary albumin excretion is an independent predictor of atherosclerotic vascular disease in insulin-dependent diabetes mellitus.

Surgical infections with Mycoplasma: a brief review

Mycoplasma hominis and Ureaplasma urealyticum are common inhabitants of the human genital tract. Evidence for an aetiological role in pyelonephritis, pelvic inflammatory disease, post-abortion and post-partum fever has been presented. There are sporadic reports of Mycoplasma causing serious extragenital infection such as septicemia, septic arthritis, neonatal meningitis and encephalitis. We review 38 cases of surgical infections with Mycoplasma.

Urinary albumin excretion and history of acute myocardial infarction in a cross-sectional population study of 2,613 individuals

BACKGROUND

Preliminary studies have suggested that microalbuminuria--a slightly increased urinary excretion of albumin--is a risk factor for atherosclerosis. The aim of this study was to examine whether an association exists between urinary excretion of albumin and a history of acute myocardial infarction, in a major population sample.

METHODS

The study was performed as a part of the 3rd Copenhagen City Heart Study, Denmark, 1992-1994, and included 2,613 participants aged 30-70 years, and without diabetes mellitus, renal or urinary tract disease or haematuria. The study programme included measurement of urinary albumin excretion rate, acquisition of information regarding previous acute myocardial infarction (verified by the Danish Hospital Register) and tobacco and alcohol consumption, 12-lead resting electrocardiogram, and measurement of blood pressure, body mass index, waist:hip ratio, plasma concentrations of total cholesterol, HDL cholesterol and fibrinogen, serum albumin concentration and glomerular filtration rate.

RESULTS

Among the participants, 3.6% presented with a history of acute myocardial infarction. There was a positive association between urinary albumin excretion rate (logarithmically transformed) and acute myocardial infarction (odds ratio 1.35, 95% confidence interval 1.08 to 1.70, n = 2, 613; P = 0.01), which was independent of age, sex conventional atherosclerotic risk factors, and glomerular filtration rate. The odds ratio for acute myocardial infarction associated with microalbuminuria (urinary albumin excretion rate exceeding the upper decile in the entire study population) was 2.06 (95% confidence interval 1.20 to 3.55, n = 2,613; P = 0.009).

CONCLUSION

There exists a positive and independent association between urinary excretion of albumin and a history of acute myocardial infarction. Follow-up analyses should determine the time sequence of this association.

Detecting microalbuminuria by urinary albumin/creatinine concentration ratio

BACKGROUND

Microalbuminuria, i.e. a subclinical increase of the albumin excretion rate in urine, may be a novel atherosclerotic risk factor. This study aimed to test whether microalbuminuria can be identified by measurement of urinary albumin concentration or urinary albumin/creatinine concentration ratio, instead of the usual measurement of the albumin excretion rate in a timed urine collection.

METHODS

All 2579 subjects analysed were screened in a population based epidemiological study. Participants with diabetes mellitus, renal disease, haematuria, or urinary tract infection were not included. Urinary albumin (Ualb) and creatinine (Ucreat) concentrations were measured in an overnight collected sample by enzyme-linked immunosorbent and colorimetric assays, respectively. Urinary albumin excretion rate (UAER) and urinary albumin/creatinine concentration ratio (Ualb/Ucreat) were calculated.

RESULTS

The correlation between Ualb and UAER was 0.72 (n = 2579, P < 0.001), and the correlation between Ualb/Ucreat and UAER was 0.81 (n = 2579, P < 0.001). In the detection of microalbuminuria, the nosographic sensitivity and specificity, and the diagnostic specificity were 58%, 97%, and 66% for Ualb, and 73%, 97%, and 73% for Ualb/Ucreat, respectively.

CONCLUSIONS

It is concluded that measurement of the albumin/creatinine concentration ratio is a specific and quite sensitive alternative to measurement of the urinary albumin excretion rate in timed collections, when screening for microalbuminuria.

High rate of nasopharyngeal carriage of potential pathogens among children in Greenland: results of a clinical survey of middle-ear disease

Nasopharyngeal and middle-ear colonization with bacteria and viruses, including Mycoplasma pneumoniae and chlamydiae, was investigated in a survey of 54 children with acute otitis media (AOM) and 201 control children without AOM in Greenland. In total, 98% with AOM and 91% without AOM carried potentially pathogenic bacteria in the nasopharynx. Two or more potentially pathogenic species were carried by 78% with AOM and 57% without AOM. Haemophilus influenzae was found in 92% and 77%, respectively, but only Streptococcus pneumoniae was found significantly more often in the nasopharynx of children with AOM than in age-matched controls (P < .03). The two species were found in 22 of 24 ear-discharge specimens. Nine children (three with AOM) had chlamydiae in the nasopharynx, and seven of them reported rhinitis. Enteroviruses or rhinoviruses were detected in 23 nasopharyngeal specimens from 39 children with AOM, in 13 such specimens from 39 children without AOM (P = .040), and in 4 of 14 ear-discharge specimens. The potentially pathogenic load in the nasopharynx was massive, suggesting an association with the high prevalence of otitis media among children in Greenland.

Raised serum sialic acid concentration precedes onset of microalbuminuria in IDDM. A 10-year follow-up study

OBJECTIVE

Elevated concentrations of serum sialic acid, a potent cardiovascular risk factor in the general population, have been found in patients with IDDM and microalbuminuria. We investigated whether a coincidence exists between the increase of sialic acid concentrations and albuminuria in the transition from normoalbuminuria to microalbuminuria. Furthermore, the predictability of increased sialic acid as well as von Willebrand factor (vWF) and total and HDL cholesterol concentrations in development of persistent microalbuminuria in IDDM was investigated.

RESEARCH DESIGN AND METHODS

This 10-year prospective study was carried out in a cohort of 209 IDDM patients with normoalbuminuria at baseline.

RESULTS

Of the cohort, 198 patients completed the follow-up period and 27 developed persistent microalbuminuria (urinary albumin excretion rate [UAER] > or = 30 mg/24 h). A coincident increase of UAER and serum sialic acid concentration was seen before persistent microalbuminuria was diagnosed. Elevation of serum sialic acid concentrations in those who later developed microalbuminuria occurred 3 years before the diagnosis of persistent microalbuminuria. Baseline serum sialic acid concentrations were significantly higher in the group of patients who later developed microalbuminuria than in the group who remained normoalbuminuric (2.02 +/- 0.41 vs. 1.85 +/- 0.31 mmol/l [means +/- SD], P < 0.05). Baseline serum sialic acid concentration correlated significantly with HbA1c, UAER, blood pressure, total cholesterol, HDL cholesterol, and vWF and was significantly predictive for development of microalbuminuria (hazards ratio [95% CI], 3.1 [1.2-8.1]; P = 0.02) after adjustments for sex, duration of diabetes, smoking, blood pressure, vWF, total cholesterol, and HDL cholesterol. Adjustment for the effects of HbA1c and UAER, however, canceled out the predictive effect of serum sialic acid.

CONCLUSIONS

UAER and serum sialic acid concentration increase coincidentally before the onset of persistent microalbuminuria. An increased serum sialic acid concentration is predictive for the onset of microalbuminuria independent of age, sex, diabetes duration, smoking, blood pressure, vWF, and total HDL cholesterol.

Cohort study of predictive value of urinary albumin excretion for atherosclerotic vascular disease in patients with insulin dependent diabetes

OBJECTIVE

To examine whether slightly elevated urinary albumin excretion precedes development of atherosclerotic vascular disease in patients with insulin dependent diabetes independently of conventional atherogenic risk factors and of diabetic nephropathy.

DESIGN

Cohort study with 11 year follow up.

SETTING

Diabetes centre in Denmark.

SUBJECTS

259 patients aged 19-51 with insulin dependent diabetes of 6-34 years' duration and without atherosclerotic vascular disease or diabetic nephropathy at baseline.

MAIN OUTCOME MEASURES

Baseline variables: urinary albumin excretion, blood pressure, smoking habits, and serum concentrations of total cholesterol, high density lipoprotein cholesterol, sialic acid, and von Willebrand factor.

END POINT

atherosclerotic vascular disease assessed by death certificates, mailed questionnaires, and hospital records.

RESULTS

Thirty patients developed atherosclerotic vascular disease during follow up of 2457 person year. Elevated urinary albumin excretion was significantly predictive of atherosclerotic vascular disease (hazard ratio 1.06 (95% confidence interval 1.02 to 1.18) per 5 mg increase in 24 hour urinary albumin excretion, P = 0.002). Predictive effect was independent of age; sex; blood pressure; smoking; serum concentrations of total cholesterol, high density lipoprotein cholesterol, sialic acid, and von Willebrand factor; level of haemoglobin A(lc); insulin dose, duration of diabetes, and diabetic nephropathy (hazard ratio 1.04 (1.01 to 1.08) per 5 mg increase

Raised serum sialic acid concentration in NIDDM patients with and without diabetic nephropathy

OBJECTIVE

Raised serum sialic acid concentration is a strong predictor of cardiovascular mortality in the general white population. A progressive increase in cardiovascular morbidity and mortality takes place in relation to increasing albuminuria in NIDDM patients. Therefore, we investigated the potential association between serum sialic acid and micro- and macroangiopathy in NIDDM patients.

RESEARCH DESIGN AND METHODS

We studied a prevalence cohort of all white NIDDM patients < 76 years of age attending a diabetic clinic during 1 year. Of the patients, 319 had normoalbuminuria, 148 had microalbuminuria, and 75 had macroalbuminuria (diabetic nephropathy was in 47 of 75 patients); 66 nondiabetic age- and sex-matched subjects acted as a control group. Blood samples were taken for measurements of sialic acid, lipids, creatinine, and HbA1C. Retinopathy was assessed by funduscopy. The prevalence of cardiovascular disease was based on Minnesota-coded electrocardiograms and the World Health Organization cardiovascular questionnaire.

RESULTS

A progressive raise in serum sialic acid was demonstrated with an increasing urinary albumin excretion rate: [median (range)] 2.02 (1.55-2.63); 2.42 (1.47-6.48); 2.67 (1.57-5.86), and 2.95 (1.52-7.86) mmol/l in nondiabetic subjects, NIDDM patients with normoalbuminuria, microalbuminuria, and diabetic nephropathy, respectively (P < 0.05 or less for differences between groups). Multiple linear regression analysis showed that serum cholesterol concentration, serum HDL cholesterol concentration, BMI, albuminuria, smoking, and cardiovascular disease correlate independently with logarithmic (10) serum sialic acid concentration.

CONCLUSIONS

Our study revealed a progressive raise in serum sialic acid with increasing urinary albumin excretion rate in NIDDM patients. Furthermore, several modifiable cardiovascular risk factors were associated with serum sialic acid.

Isolation of Mycoplasma genitalium strains from the male urethra

Mycoplasma genitalium is a human mycoplasma species which, on the basis of detection by PCR, has been incriminated as a cause of nongonococcal urethritis. Previously, only two strains from the urogenital tract and five strains from extragenital sites have been isolated. We have developed a method for the isolation of this fastidious microbe. M. genitalium from PCR-positive urethral specimens was initially propagated in Vero cell cultures grown in serum-free medium supplemented with Ultroser HY serum substitute. Growth was monitored by PCR. The M. genitalium strains grown in cell cultures could subsequently be subcultured in modified Friis's FF broth medium. Several passages in broth medium were required before growth on agar medium was attained. A total of 11 urethral specimens positive for M. genitalium by PCR from male patients with urethritis were investigated. Six strains were adapted to growth in broth medium, and four of these strains were cloned. Three specimens were overgrown by other mycoplasmas during propagation in the cell cultures. In only two PCR-positive specimens was propagation of M. genitalium unsuccessful. The use of cell culture combined with PCR monitoring of mycoplasmal growth may prove to be more widely applicable for the isolation of other fastidious mollicutes.

Insulin sensitivity in clinically healthy individuals with microalbuminuria

In epidemiologic studies microalbuminuria is associated with increased atherosclerotic risk profile, morbidity, and mortality. In order to examine whether such association could be explained by impaired insulin sensitivity, 23 clinically healthy subjects with microalbuminuria (urinary albumin excretion rate (UAER) of 6.6 to 150 micrograms/min) and 24 age- and sex-matched controls with normoalbuminuria (UAER < or = 6.6 micrograms/min) underwent a 3 h hyperinsulinaemic euglycaemic clamp investigation using an intravenous insulin infusion rate on 2 mU/(kg body weight x min). Insulin sensitivity (whole body glucose disposal) was similar in the two groups ((mean (95% C.I.)) 351 (321-381) vs. 364 (339-388) mg/(m2 x min); P = 0.51). Among urinary albumin excretion rate, blood pressure, serum lipid concentrations, body mass index waist-hip ratio, fasting concentrations of serum insulin and blood glucose, tobacco and alcohol consumption, physical activity, and age and sex, fasting serum insulin concentration was the only variable independently associated with insulin sensitivity (r = -0.55; P = 0.0001). It is concluded that microalbuminuria is not associated with impaired insulin sensitivity in clinically healthy individuals. The effect of microalbuminuria as predictor of atherosclerotic vascular disease may be mediated through other factors.

Characterization of repetitive DNA in the Mycoplasma genitalium genome: possible role in the generation of antigenic variation

We have characterized a family of repetitive DNA elements with homology to the MgPa cellular adhesion operon of Mycoplasma genitalium, a bacterium that has the smallest known genome of any free-living organism. One element, 2272 bp in length and flanked by DNA with no homology to MgPa, was completely sequenced. At least four others were partially sequenced. The complete element is a composite of six regions. Five of these regions show sequence similarity with nonadjacent segments of genes of the MgPa operon. The sixth region, located near the center of the element, is an A+T-rich sequence that has only been found in this repeat family. Open reading frames are present within the five individual regions showing sequence homology to MgPa and the adjacent open reading frame 3 (ORF3) gene. However, termination codons are found between adjacent regions of homology to the MgPa operon and in the A+T-rich sequence. Thus, these repetitive elements do not appear to be directly expressible protein coding sequences. The sequence of one region from five different repetitive elements was compared with the homologous region of the MgPa gene from the type strain G37 and four newly isolated M. genitalium strains. Recombination between repetitive elements of strain G37 and the MgPa operon can explain the majority of polymorphisms within our partial sequences of the MgPa genes of the new isolates. Therefore, we propose that the repetitive elements of M. genitalium provide a reservoir of sequence that contributes to antigenic variation in proteins of the MgPa cellular adhesion operon.

Interface mechanics and histomorphometric analysis of hydroxyapatite-coated and porous glass-ceramic implants in canine bone

A canine study was performed to make a histological and biomechanical evaluation of the interface between bone and two different bioceramic implants. A newly developed glass-ceramic formed by P2O5, CaO, SiO2, and Al2O3, giving a crystal phase composed of CaP2O6-AlPO4-SiP2O7, was compared to hydroxyapatite (HA) coated Ti-6Al-4V implants. A total of 24 implants were inserted into the femoral condyle of 15 adult female golden retriever dogs weighing 20-25 kg. There was a 12 week follow-up. Implants were examined by mechanical testing, histology, histomorphometry, microradiograpic methods, and EDAX analysis. The ultimate shear strength for the HA-coated implants was significantly higher than in the glass-ceramic group. When these values were related to the histomorphometric measurements, the difference could be explained by the tissue-to-implant contact. The glass-ceramic showed direct contact only with nonmineralized, osteoid bone. The HA-coated implants, however, were integrated into the bone. The study indicated that porous glass-ceramic containing AlPO4 causes local osteomalacia and might not be suitable for clinical purposes.

Renal and systemic transvascular albumin leakage in severe atherosclerosis

Microalbuminuria was recently proposed as a novel atherogenic risk factor. The pathophysiological link between microalbuminuria and atherosclerosis may be mediated through an increased generalized transvascular leakage of albumin. To investigate this hypothesis, urinary albumin excretion and clearance and systemic transvascular albumin leakage (TERalb) were measured in 23 patients with severe clinical atherosclerosis and 25 healthy controls. In addition, renal clearances of three other endogenous plasma proteins (IgG, IgG4, and beta 2-microglobulin) and of creatinine were measured. Measurements of urine and serum proteins were done by enzyme-linked immunosorbent assays. TERalb was measured by the fractional disappearance rate of 125I-albumin from the total intravascular compartment in 1 hour after intravenous injection. Glomerular filtration rate was estimated as creatinine clearance. Urinary albumin excretion (geometric means [95% confidence intervals], 10.5 [6.1 to 18.3] versus 5.7 [4.7 to 6.9] micrograms/min; P < .05), fractional urinary albumin clearance (2.8 [1.6 to 4.8] x 10(-6) versus 1.3 [1.0 to 1.6] x 10(-6); P < .05), and TERalb (6.0 [5.5 to 6.5] versus 5.1 [4.5 to 5.8] %/h; P < .05) were higher in patients than in control subjects. Glomerular charge selectivity (ratio of IgG clearance to IgG4 clearance) was lower in patients than in control subjects (1.5 [1.1 to 2.0] versus 2.3 [2.0 to 2.6]; P < .05). These alterations were independent of blood pressure, glomerular filtration rate, tubular function, and smoking status. It is concluded that atherosclerotic vascular disease is associated with renal and systemic transvascular leakiness for albumin. Theoretically, such leakiness may in addition allow for an increased lipid insudation into the large vessel wall, thereby linking microalbuminuria to atherogenesis.(ABSTRACT TRUNCATED AT 250 WORDS)

Reduced glomerular size- and charge-selectivity in clinically healthy individuals with microalbuminuria

The pathophysiologic mechanism behind microalbuminuria, a potential atherosclerotic risk factor, was explored by measuring fractional clearances of four endogenous plasma proteins of different size and electric charge (albumin, beta 2-microglobulin, immunoglobulin G, and immunoglobulin G4). Twenty-eight clinically healthy individuals with microalbuminuria, defined as a urinary albumin excretion of 6.6-150 micrograms min-1, and 60 matched control subjects were studied. Fractional immunoglobulin G clearance was higher (geometric means (95% confidence intervals)) 3.0 (2.3-3.9) x 10(-6), n = 28, vs. 2.1 (1.8-2.4) x 10(-6), n = 60; P = 0.02), whereas the ratio immunoglobulin G clearance/immunoglobulin G4 clearance was lower (geometric means (95% confidence intervals)) 1.8 (1.4-2.2), n = 28, vs. 2.3 (2.0-2.5), n = 60; P = 0.03) in microalbuminuric than in normoalbuminuric individuals. Fractional beta 2-microglobulin clearance was similar in the two groups. Since total IgG and the IgG4 subclass are of similar size and configuration but electrically neutral and negative, respectively; these findings indicate that microalbuminuria is associated with decreased size- and charge-selectivity of the glomerular vessel wall. Hypothetically, such alterations may reflect generalized vascular abnormalities linking microalbuminuria to atherogenesis.

Blood perfusion and remodelling activity in canine tibial diaphysis after filling with a new bone cement compared to bone wax and poly(methyl methacrylate) cement

Six dogs each had one tibia filled with standard poly(methyl methacrylate) (PMMA) bone cement and the contralateral tibia filled with a new methyl methacrylate-n-decyl methacrylate-isobornyl methacrylate (MMA-DMA-IBMA) bone cement (Boneloc) with lowered polymerization heat and monomer leakage. An additional six dogs each had one tibia filled with MMA-DMA-IBMA and the contralateral tibia filled with bone wax. There was a higher diaphyseal blood flow, measured with a microsphere technique, in the legs filled with MMA-DMA-IBMA than in those filled with PMMA. The wax-filled bones presented higher blood perfusion than those with MMA-DMA-IBMA. We found a tendency towards higher 99mtechnetium-labelled methylene diphosphonate (99mTcMDP) uptake, and autoradiograms revealed a tendency towards larger subperiosteal apposition and more blackening, both at the subperiosteal apposition and the cortex, in the bones filled with new bone cement in the first series, but in wax-filled bone in the second series. It is concluded that the new bone cement, compared to standard acrylic bone cement, seems to inhibit the vascular response and bone remodelling activity less, making earlier remodelling possible. However, the new bone cement still seems to inhibit bone blood perfusion compared to bone wax.

Microalbuminuria reflects a generalized transvascular albumin leakiness in clinically healthy subjects

1. In epidemiological studies microalbuminuria, i.e. slightly elevated urinary albumin excretion rate, predicts increased atherosclerotic vascular morbidity and mortality. This study aimed to test the hypothesis that microalbuminuria in clinically healthy subjects is associated with a systemic transvascular albumin leakiness. In animal experiments the outflux of albumin and lipids to the arterial wall are highly correlated, and both are elevated in atherosclerosis. 2. All participants were recruited at random from a population-based epidemiological study, where the upper decile of urinary albumin excretion rate was 6.6 micrograms/min. Twenty-seven patients with persistent microalbuminuria (urinary albumin excretion rate 6.6-150 micrograms/min), and 56 age- and sex-matched control subjects with persistent normoalbuminuria (UAER < or = 6.6 micrograms/min) were studied. 3. The systemic transvascular albumin leakage was measured as the fractional disappearance rate of 125I-labelled albumin from the total plasma compartment in 1 h after intravenous injection. 4. The fractional disappearance rate of albumin from the plasma compartment was higher in the microalbuminuric than in the normoalbuminuric group [5.8 (95% confidence interval 5.3-6.2; n = 27) versus 5.0 (4.6-5.5; n = 56)%/h, P < 0.05]. The positive correlation between urinary albumin excretion rate on continuous scale (logarithmically transformed) and the fractional disappearance rate of albumin from the plasma compartment [slope 0.4 (95% confidence interval 0.1-0.7; n = 83), r = 0.29, P < 0.005] was independent of age, sex, smoking status, blood pressure, body size, plasma volume, plasma albumin concentration and concentrations of blood glucose, serum insulin and serum lipids. 5. In conclusion, microalbuminuria is an independent marker of systemic transvascular albumin leakiness in clinically healthy subjects.(ABSTRACT TRUNCATED AT 250 WORDS)

Serum sialic acid concentration is elevated in IDDM especially in early diabetic nephropathy

OBJECTIVES

Elevated serum sialic acid concentration is a strong predictor of cardiovascular mortality in non-diabetic subjects. Because patients with insulin-dependent diabetes mellitus (IDDM) and albuminuria have a highly increased cardiovascular morbidity and mortality, we hypothesized that IDDM patients with albuminuria would have an increased concentration of serum sialic acid.

DESIGN

Cross-sectional study.

SETTING

Outpatient clinic at Steno Diabetes Centre, Gentofte, Denmark.

SUBJECTS

Twenty-six non-diabetic controls and 74 IDDM patients with normoalbuminuria (urinary albumin excretion [UAE] < 30 mg 24 h-1; n = 37), incipient nephropathy (UAE 30-300 mg 24 h-1; n = 20) and clinical nephropathy (UAE > 300 mg 24 h-1; n = 17), matched for sex, age and body mass index (BMI).

MAIN OUTCOME MEASURES

Serum sialic acid concentration, concurrent fasting blood glucose, glycated haemoglobin (HbA1c), serum creatinine, plasma fibrinogen and erythrocyte sedimentation rate.

RESULTS

Normoalbuminuric patients had a higher serum sialic acid concentration (mmol L-1) than non-diabetic controls (1.83 +/- 0.24 vs. 1.67 +/- 0.26; P < 0.02). Serum sialic acid concentration was further increased in patients with incipient nephropathy (2.02 +/- 0.37; P < 0.03) and in patients with clinical nephropathy (2.13 +/- 0.33; P < 0.002) compared with normoalbuminuric IDDM patients. Serum sialic acid correlated strongly with plasma fibrinogen (r = 0.78; P < 0.0001) and erythrocyte sedimentation rate (r = 0.62; P < 0.0001). In a multiple regression analysis including UAE, retinopathy status, fasting blood glucose, HbA1c, mean blood pressure, serum creatinine, age, BMI, duration and smoking. UAE and fasting blood glucose were the independent variables which correlated significantly with serum sialic acid concentration (P < 0.0001 and P < 0.05, respectively).

CONCLUSION

Serum sialic acid is elevated in IDDM especially in albuminuric patients. Whether elevated serum sialic acid is predictive for early diabetic nephropathy and cardiovascular disease in IDDM has to be shown in the future.

Aspects of haemostatic function in healthy subjects with microalbuminuria--a potential atherosclerotic risk factor

Microalbuminuria, i.e., slightly elevated urinary albumin excretion rate (UAER), notifies increased risk for atherosclerotic disease and may reflect an early generalized vascular abnormality in healthy subjects. This study was designed in order to examine whether such abnormality is associated with a shift of the haemostatic balance in prothrombotic direction. The following haemostatic factors were measured in two representative groups of clinically healthy subjects, 28 with microalbuminuria (UAER of 6.6-150 micrograms/min) and 60 age- and sex-matched controls with normoalbuminuria (UAER < 6.6 micrograms/min): Coagulation factors: blood platelet count and mean volume, plasma Factor VII antigen concentration and coagulant activity, and plasma concentrations of prothrombin fragment 1 + 2, thrombin-antithrombin III complexes, fibrinogen, and fibrinopeptide A; fibrinolytic and endothelial factors: plasma concentrations of tissue plasminogen activator antigen and plasminogen activator inhibitor type 1 antigen; and endothelial factor: plasma von Willebrand factor antigen concentration. The fibrinolytic and endothelial factors were measured both before and after 10 minutes of venous occlusion of the arm. None of the haemostatic factors were significantly altered in the microalbuminuric group. Plasma fibrinogen concentration tended to be elevated but not statistically significant ((mean (95% C.I.) 7.8 (7.2-8.3) vs. 7.2 (6.9-7.5) mumol/l; p < 0.1). Neither did any of the haemostatic factors correlate with UAER in regression analyses. It is concluded that the haemostatic balance is unaltered in healthy subjects with microalbuminuria. It is unlikely that a prothrombotic state is present as an intermedial factor early in a causal chain between microalbuminuria and atherosclerotic vascular disease.

Nosocomial legionellosis in three heart-lung transplant patients: case reports and environmental observations

Organ transplant recipients are at high risk of contracting Legionnaires' disease in a hospital environment contaminated with legionellae. This study describes the first cases of culture-verified Legionella infections with an established link to potable hospital water in Denmark; three patients operated on at the Cardiopulmonary Transplant Unit, Rigshospitalet, Copenhagen, became infected with legionellae. Environmental and clinical isolates of Legionella pneumophila serogroups 1 and 6 were investigated by restriction enzyme analysis and ribotyping. An ice machine located in the kitchen of the intensive care unit was implicated as a source of infection in two of the three cases.

Atherosclerotic risk factors are increased in clinically healthy subjects with microalbuminuria

Increased morbidity and mortality from atherosclerotic vascular disease were observed in subjects with slightly elevated urinary albumin excretion rate (UAER), known as microalbuminuria. Therefore, the association between microalbuminuria and established atherogenic risk factors was studied in clinically healthy subjects. All healthy 40-65 year-old participants with microalbuminuria, examined within the first 21 months of The Copenhagen City Heart Study, were invited, and 28 were studied. An age- and sex-matched group of 60 randomly chosen subjects with normoalbuminuria served as control. Microalbuminuria was defined as a UAER of 6.6-150 micrograms/min, and normoalbuminuria as a UAER < or = 6.6 micrograms/min. In the microalbuminuric group, systolic and diastolic blood pressures were both elevated (mean (95% C.I.) 128 (123-134) vs. 119 (116-122) mmHg; P = 0.005, and 75 (71-78) vs. 69 (67-71) mmHg; P = 0.008, respectively), and serum apolipoprotein (apo) A-1 concentration was lower (1.30 (1.20-1.37) vs. 1.42 (1.36-1.47) milligrams; P = 0.02) in comparison with the normoalbuminuric group. Furthermore, serum HDL-cholesterol concentration tended to be lower, whereas body weight, body mass index and fasting serum insulin concentration were slightly elevated in the microalbuminuric group but not statistically significant. It is concluded that microalbuminuria in clinically healthy subjects is associated with increased levels of atherogenic risk factors. This may contribute to the increased vascular morbidity and mortality observed in these individuals.

Innovations in acrylic bone cement and application equipment

A new bone cement was developed with the purpose of reducing the adverse biological effects during cementation of implants. This bone cement is characterized by lower exotherm, low release of monomer, low residual content of monomer, and retained physical properties. The essential innovation was substitution of half of the methylmethacrylate (MMA) in the monomer with long chain, high molecular weight, less volatile, and less soluble methacrylates (n-decylmethacrylate, isobornyl-methacrylate), as well as alteration of the accelerator system to a mix of dihydroxypropyl-p-toluidine and N,N-dimethyl-p-toluidine. The powder contains butylmethacrylate-MMA copolymers. These measures lower the glass-transition temperature, and permit more complete mixing in an integrated package, mixing, and delivery system consisting of a vacuum packed, double chamber pouch. The porosity was reduced to about 2% and the largest voids measured 0.1 mm. The polymerization exotherm was reduced to 58 degrees C. The compressive strength was 82 MPa, the four-point bending strength 55 MPa, the flexural modulus 2.24 GPa, the tensile strength 32 MPa, and the shear strength 36 MPa. The fracture toughness was 0.89 MPa square root of cm. These mechanical properties together with the fatigue life were on level with manually mixed, conventional PMMA bone cements.

Microalbuminuria: an important diagnostic tool

The concept of microalbuminuria is reviewed. Measuring the urinary albumin excretion rate and testing for microalbuminuria is well established in the control and treatment of patients with insulin-dependent diabetes mellitus. Microalbuminuria predicts nephropathy and early cardiovascular death. In the presence of microalbuminuria frequent examinations are warranted for early detection of retinopathy, blood-pressure rise, and for optimizing the glycemic control. In patients with non-insulin-dependent diabetes, the independent value of microalbuminuria as a cardiovascular risk factor is not yet clarified. The urinary albumin excretion rate should be measured at diagnosis, because the indications are that presence of microalbuminuria reinforces the urge to intervene against other well-documented cardiovascular risk factors (hypertension, dyslipidemia, tobacco, and obesity). In the nondiabetic population, there is accumulating evidence that an elevated urinary albumin excretion rate is associated with early cardiovascular morbidity and mortality. Large scale cross-sectional and prospective studies are needed in order to clarify further the role of microalbuminuria as an independent risk factor in the background population.

Intracellular location of Mycoplasma genitalium in cultured Vero cells as demonstrated by electron microscopy

The original two strains of Mycoplasma genitalium were isolated from the human urogenital tract. No other strains have been isolated from this site since then. We have recently succeeded in propagating a third strain from a urogenital specimen from a patient with urethritis in Vero cell cultures. By electron microscopy mycoplasmas were demonstrated intracellularly in about 10% of the examined Vero cells. Various stages of penetration into the cells could be observed. The flask-shaped organisms seemed to penetrate into the cells by the tip-end which included a rodlike structure. The intracellular location of normal mycoplasmas were in membrane-bound vacuoles very close to the nucleus, occasionally together with a few disintegrated organisms. In a few cells additional material was entangling the mycoplasmas in the cytoplasmic vacuoles. The potential for intracellular survival of M. genitalium may help the organism to evade the defence mechanisms of the human body. This trait may be considered a pathogenic property which supports the presumption that M. genitalium has clinical importance.

Effects of polymerization heat and monomers from acrylic cement on canine bone

We investigated the effects of polymerization heat and toxicity of polymethylmetacrylate bone cement in the canine tibial diaphysis. Heat was studied by filling the tibias with either bone cement or bone wax contained in a monomer tight membrane pouch. Toxicity was studied by filling both tibias with cement, with the control side contained in the membrane pouch. Bone blood perfusion was measured by microsphere technic, and bone remodeling by 99mTc-methylene diphosphonate uptake and by histologic technique. In bone exposed to the combination of polymerization heat and monomer, both perfusion and remodeling were impaired. We did not find any effects of polymerization heat alone. We conclude that hot toxic chemicals from bone cement during polymerization may inhibit bone blood perfusion and remodeling, whereas heat alone seems to be of minor importance for the regenerative processes in cemented diaphyseal bone.

[Microalbuminuria--a valuable diagnostic parameter]

The concept of microalbuminuria is reviewed. Measuring the urinary albumin excretion rate and testing for microalbuminuria is well established in the control and treatment of patients with insulin-dependent diabetes mellitus. Microalbuminuria predicts nephropathy and early cardiovascular death. In the presence of microalbuminuria, frequent examinations are warranted for early detection of retinopathy, hypertension and for optimizing the glycaemic control. In patients with non-insulin dependent diabetes, the independent value of microalbuminuria as a cardiovascular risk factor is not yet clarified. The urinary albumin excretion rate should be measured at diagnosis, because the indications are that presence of microalbuminuria reinforces the urge to intervene against other well-documented cardiovascular risk-factors (hypertension, dyslipidemia, tobacco and obesity). In the non-diabetic population there is accumulating evidence that an elevated urinary albumin excretion rate is associated with early cardiovascular morbidity and mortality. Large scale cross-sectional and prospective studies are needed in order to further clarify the role of microalbuminuria as an independent risk factor in the background population.

[Screening of microalbuminuria with the Micral-Test. A semi-quantitative urinary dipstick]

Microalbuminuria, defined as a urinary albumin excretion rate of 20-200 micrograms/min, predicts diabetic nephropathy and cardiovascular disease in diabetic patients. An increased urinary albumin excretion rate is probably also associated with cardiovascular disease in non-diabetic subjects. Thus, screening for microalbuminuria is of major importance. A semi-quantitative urinary dipstick method, Micral-Test, has been developed for this purpose. In a urine sample collected overnight from each of 1359 subjects the Micral-Test was evaluated with a quantitative ELISA-method as the standard. Sensitivity, specificity and diagnostic specificity in detecting microalbuminuria was 92, 58 and 12% respectively. The prevalence of microalbuminuria was 5.6%. In conclusion, the Micral-Test is highly sensitive in detecting microalbuminuria, but at the expense of a relatively high number of false positive tests.

Urinary albumin excretion in a population based sample of 1011 middle aged non-diabetic subjects. The Copenhagen City Heart Study Group

Increased urinary albumin excretion rate (UAER) especially in the range of 20-200 micrograms min-1, termed microalbuminuria, has been proposed as a risk marker and predictor for cardiovascular disease in non-diabetic subjects. Thus it would be of importance to describe the distribution of UAER in the non-diabetic population. Among 1011 30-70-year-old subjects without diabetes mellitus or urinary tract infection, who were invited to participate in a population based epidemiological study, the albumin concentration was measured in an overnight urine sample. The measurement was performed by an ELISA method. The UAER was calculated in units of micrograms min-1 as urinary albumin concentration x urine volume/urine collection time. The distribution of UAER was positively skewed with a median value of 2.3 micrograms min-1 and a 5-95 interpercentile range of 0-11.0 micrograms min-1. The UAER held constant with age, but males had higher UAER than females, 2.6 (0-13.5) micrograms min-1 vs 2.2 (0-8.3) micrograms min-1; p < 0.005. The prevalence of microalbuminuria, defined as an UAER in the range of 15-150 micrograms min-1 in an overnight urine sample, was 3% (95% C.I. interval: 1.9-4.0). These findings suggest, that the level of UAER which might notify increased cardiovascular risk, is lower than in patients with diabetes mellitus, if it is considered to be of any clinical relevance.

Risk factors for recurrent aseptic loosening of the femoral component after cemented revision

A series of 160 consecutive cemented first revisions, performed from 1977 through 1988 for aseptic loosening of a primary cemented femoral component, were studied using survivorship methods with the purpose of identifying risk factors for recurrent loosening of the femoral component. Risk of recurrent loosening depended on the length of the revision stem, with a significantly increased risk of loosening if the tip of the primary stem was overbridged by the revision stem with less than one width of the femoral shaft. Risk of recurrent loosening was also related to the extension of a cement mantle, exceeding more than 2 mm, around the revision stem measured on postrevision anteroposterior radiographs. Furthermore, low age and neutral position of the revision stem were identified as risk factors for recurrent loosening of the cemented revision femoral component. An improved fixation of the cemented revision femoral component for revisions performed after 1982 could be related to the use of longer revision stems and improved cementation.