False-positive screening results in the Finnish prostate cancer screening trial

BACKGROUND

There is evidence that prostate cancer (PC) screening with prostate-specific antigen (PSA) serum test decreases PC mortality, but screening has adverse effects, such as a high false-positive (FP) rate. We investigated the proportion of FPs in a population-based randomised screening trial in Finland.

METHODS

Finland is the largest centre in the European Randomized Study of Screening for Prostate Cancer. We have completed three screening rounds with a 4-year screening interval (mean follow-up time 9.2 years) using a PSA cutoff level of 4.0 ng ml(-1); in addition, men with PSA 3.0-3.9 and a positive auxiliary test were referred. An FP result was defined as a positive screening result without cancer in biopsy within 1 year from the screening test.

RESULTS

The proportion of FP screening results varied from 3.3 to 12.1% per round. Of the screened men, 12.5% had at least one FP during three rounds. The risk of next-round PC following an FP result was 12.3-19.7 vs 1.4-3.7% following a screen-negative result (depending on the screening round), risk ratio 3.6-9.9. More than half of the men with one FP result had another one at a subsequent screen. Men with an FP result were 1.5 to 2.0 times more likely to not participate in subsequent rounds compared with men with a normal screening result (21.6-29.6 vs 14.0-16.7%).

CONCLUSION

An FP result is a common adverse effect of PC screening and affects at least every eighth man screened repeatedly, even when using a relatively high cutoff level. False-positive men constitute a special group that receives unnecessary interventions but may harbour missed cancers. New strategies are needed for risk stratification in PC screening to minimise the proportion of FP men.

Aurothiomalate and hydroxychloroquine inhibit nitric oxide production in chondrocytes and in human osteoarthritic cartilage

OBJECTIVES

Nitric oxide (NO) is a destructive mediator produced by activated chondrocytes. The aim of the present study was to investigate the effect of disease-modifying anti-rheumatic drugs (DMARDs) on interleukin-1beta (IL-1beta)-induced NO production in chondrocyte cultures, and in human osteoarthritic cartilage.

RESULTS

Aurothiomalate, hydroxychloroquine, methotrexate and leflunomide inhibited IL-1beta-induced inducible NO synthase (iNOS) expression and NO production in immortalized H4 chondrocytes, while penicillamine and sulfasalazine had no effect. This can be explained by the fact that the four effective DMARDs also suppressed IL-1beta-induced activation of nuclear factor kappa B (NF-kappaB), which is a crucial transcription factor for iNOS. Aurothiomalate and hydroxychloroquine also inhibited IL-1beta-induced NO production in OA cartilage whereas methotrexate and leflunomide had no effect.

CONCLUSION

Aurothiomalate and hydroxychloroquine suppressed IL-1beta-induced NO production in chondrocyte cultures and in OA cartilage. The results suggest an additional anti-inflammatory mechanism for aurothiomalate and hydroxychloroquine and indicates their possible therapeutic value in the treatment of osteoarthritis (OA).

Biogenesis of the Semliki Forest virus RNA replication complex

The nonstructural (ns) proteins nsP1 to -4, the components of Semliki Forest virus (SFV) RNA polymerase, were localized in infected cells by confocal microscopy using double labeling with specific antisera against the individual ns proteins. All ns proteins were associated with large cytoplasmic vacuoles (CPV), the inner surfaces of which were covered by small invaginations, or spherules, typical of alphavirus infection. All ns proteins were localized by immuno-electron microscopy (EM) to the limiting membranes of CPV and to the spherules, together with newly labeled viral RNA. Along with earlier observations by EM-autoradiography (P. M. Grimley, I. K. Berezesky, and R. M. Friedman, J. Virol. 2:326-338, 1968), these results suggest that individual spherules represent template-associated RNA polymerase complexes. Immunoprecipitation of radiolabeled ns proteins showed that each antiserum precipitated the other three ns proteins, implying that they functioned as a complex. Double labeling with organelle-specific and anti-ns-protein antisera showed that CPV were derivatives of late endosomes and lysosomes. Indeed, CPV frequently contained endocytosed bovine serum albumin-coated gold particles, introduced into the medium at different times after infection. With time, increasing numbers of spherules were also observed on the cell surfaces; they were occasionally released into the medium, probably by secretory lysosomes. We suggest that the spherules arise by primary assembly of the RNA replication complexes at the plasma membrane, guided there by nsP1, which has affinity to lipids specific for the cytoplasmic leaflet of the plasma membrane. Endosomal recycling and fusion of CPV with the plasma membrane can circulate spherules between the plasma membrane and the endosomal-lysosomal compartment.

Effects of palmitoylation of replicase protein nsP1 on alphavirus infection

The membrane-associated alphavirus RNA replication complex contains four virus-encoded subunits, the nonstructural proteins nsP1 to nsP4. Semliki Forest virus (SFV) nsP1 is hydrophobically modified by palmitoylation of cysteines 418 to 420. Here we show that Sindbis virus nsP1 is also palmitoylated on the same site (cysteine 420). When mutations preventing nsP1 palmitoylation were introduced into the genomes of these two alphaviruses, the mutant viruses remained viable and replicated to high titers, although their growth was slightly delayed. The subcellular distribution of palmitoylation-defective nsP1 was altered in the mutant: it no longer localized to filopodial extensions, and a fraction of it was soluble. The ultrastructure of the alphavirus replication sites appeared normal, and the localization of the other nonstructural proteins was unaltered in the mutants. In both wild-type- and mutant-virus-infected cells, SFV nsP3 and nsP4 could be extracted from membranes only by alkaline solutions whereas the nsP2-membrane association was looser. Thus, the membrane binding properties of the alphavirus RNA replication complex were not determined by the palmitoylation of nsP1. The nsP1 palmitoylation-defective alphaviruses produced normal plaques in several cell types, but failed to give rise to plaques in HeLa cells, although they induced normal apoptosis of these cells. The SFV mutant was apathogenic in mice: it caused blood viremia, but no infectious virus was detected in the brain.

Intracellular distribution of rubella virus nonstructural protein P150

Antiserum prepared against an amino-terminal fragment of rubella virus (RUB) nonstructural polyprotein was used to study RUB-infected Vero cells. Replicase protein P150 was associated with vesicles and vacuoles of endolysosomal origin and later with large, convoluted, tubular membrane structures. Newly incorporated bromouridine was associated with the same structures and specifically with small membrane invaginations, spherules, indicating that these structures may be the sites of viral RNA synthesis.

Alphavirus replicase protein NSP1 induces filopodia and rearrangement of actin filaments

Expression of the NSP1 protein of Semliki Forest virus and Sindbis virus in cultured cells induced filopodia-like extensions containing NSP1 but not F actin. The actin stress fibers disappeared, whereas vimentin, keratin, and tubulin networks remained intact. The effects of NSP1 were dependent on its palmitoylation but not on its enzymatic activities and were also observed in virus-infected cells.

Monoclonal antibodies specific for Semliki Forest virus replicase protein nsP2

A panel of monoclonal antibodies (MAbs) was raised against Semliki Forest virus (SFV) nonstructural protein nsP2, which is a protease, an NTPase, a putative RNA helicase, and a regulator of the synthesis of the subgenomic 26S mRNA encoding the structural proteins. nsP2, used for immunization, was expressed as a histidine fusion protein in Escherichia coli and purified by metal affinity chromatography. Dot-blot assay, using a membrane fraction from SFV-infected cells as antigen, gave 33 positive clones. Of these, 30 MAbs recognized nsP2 in Western immunoblotting, and 25 showed positive indirect immunofluorescence (IFAT) in SFV-infected cells; 15 MAbs stained the cytoplasmic vacuoles (CPVI), which are the sites of viral RNA synthesis in alphavirus-infected cells. MAb 3B5 recognized only CPVIs, as shown by double immunofluorescence staining with polyclonal anti-nsP3 antiserum. Most of the MAbs (20/33) recognized the nuclear form of nsP2, which may be associated with SFV neurovirulence. Immunoprecipitation with MAbs revealed that the SFV nonstructural proteins are associated with each other. None of the MAbs recognized Sindbis virus nsP2 in immunoblotting, indicating that they were directed to non-conserved sequences specific for SFV. Interestingly, these epitopes were located mostly within the N-terminal half of nsP2. Unexpectedly, the anti-nsP2 MAb 1E9 cross-reacted strongly with a host protein of 78 kDa from uninfected human, murine, avian and insect cells. This protein was identified as the immunoglobulin binding protein, BiP, by 2-D gel mapping and reaction with anti-BiP antiserum.

The progress of cognitive decline in multiple sclerosis. A controlled 3-year follow-up

The purpose of this study was to illustrate how cognitive functioning evolves over time in patients with multiple sclerosis. We followed the evolution of cognitive performances in two clinically and demographically similar multiple sclerosis groups, the 'cognitively preserved' (n = 20) and the 'cognitively mildly deteriorated' (n = 22), and in healthy controls (n = 34). We conducted the follow-up examination using the Mild Deterioration Battery, the Mini-Mental State Examination, and a set of additional neuropsychological measures after an interval of 3 years. The drop-out rate in our study was only 5%. The 'cognitively preserved' multiple sclerosis group showed substantial neuropsychological stability by performing as well as the controls both at baseline and at follow-up. By contrast, the initially 'cognitively mildly deteriorated' group demonstrated progressive cognitive decline on many neuropsychological tests. The intermediate-length screening battery, the Mild Deterioration Battery, was sensitive to this decline, whereas the briefer Mini-Mental State Examination was not. The progressive cognitive decline could not be predicted from other disease variables. The study demonstrated that intact cognitive functioning in multiple sclerosis may remain stable, whereas incipient cognitive decline seems to be widespread and progressive in nature. Thus, progressive cognitive deterioration should be considered as one of the characteristics of multiple sclerosis.

Language functions in incipient cognitive decline in multiple sclerosis

Although the mechanisms of cognitive impairment in multiple sclerosis (MS) have been extensively studied, evaluation of language functions has been given little attention. In the present study, we evaluated whether impairment of language functions is associated with cognitive decline in MS. We studied naming, reading, and writing performance of two carefully matched patient groups differing only with respect to cognitive status. In language tasks, the patients with incipient cognitive decline not only demonstrated performance slowness but also made more errors than the patients with preserved cognitive capacity and the healthy controls. The comprehensive naming error analysis revealed that the cognitively deteriorated patients produced error types not present in the other two study groups. Contrary to previous suggestions, the present study indicates that impaired language performances in MS are attributable to mild cognitive deterioration rather than to sensory or motor factors. Thus, assessment of language functions should be included in neuropsychological evaluations of MS patients.

Memory deficits and early cognitive deterioration in MS

INTRODUCTION

In the present study, the pattern of memory and learning deficits in two cognitively different, but clinically and demographically similar, multiple sclerosis (MS) groups was compared.

MATERIAL & METHODS

23 patients represented the cognitively preserved MS group and 22 patients the MS group with early cognitive decline. A control group of 35 healthy controls was also included. The cognitive status of the subjects was defined using the Mild Deterioration Battery (MDB). Furthermore, all subjects were given a set of memory and learning tests and were instructed to evaluate the frequency of their memory and learning difficulties. The Mini-Mental State Examination (MMSE) was also administered to all subjects.

RESULTS

The cognitively deteriorated patients, even those with normal MMSE performance, showed widespread memory and learning deficits, but adequate self-evaluation of their everyday memory and learning difficulties. The preserved group, in turn, performed similarly to the controls.

CONCLUSION

Widespread memory and learning deficits are associated with relatively mild cognitive decline in MS. These deficits were observable in the intermediate-length screening battery, the MDB, but not in the MMSE. The present study suggests that the accuracy of patients' own evaluations of their memory and other cognitive problems is superior to the results of very brief screening batteries, like the MMSE. Therefore, brief screening in neuropsychological assessment of MS patients is not recommendable.

Clinical picture of community-acquired Chlamydia pneumoniae pneumonia requiring hospital treatment: a comparison between chlamydial and pneumococcal pneumonia

BACKGROUND

The importance of Chlamydia pneumoniae as a cause of pneumonia has remained controversial. The clinical picture of C pneumoniae and Streptococcus pneumoniae in patients admitted to hospital with community-acquired pneumonia was compared during a C pneumoniae epidemic in Finland.

METHODS

Group I consisted of 24 patients in whom serological testing and bacterial culture indicated an association with C pneumoniae only, group II comprised nine patients with both C pneumoniae and S pneumoniae, and group III consisted of 13 patients with S pneumoniae only.

RESULTS

The patients with C pneumoniae suffered from headache more frequently than the other patients (group I, 46%; group II, 11%; and group III, 15%) and had received antimicrobial treatment more often before admission to hospital (group I, 54%; groups II and III, 0%). The patients with C pneumoniae produced few good sputum samples and had suffered from respiratory symptoms longer than those with S pneumoniae (group I, 10 days; groups II and III, 4 days). C reactive protein values on admission were lowest in group I and highest in group II. The antimicrobial treatment provided in hospital covered C pneumoniae in 36% of cases in group I and 0% in group II, while S pneumoniae was covered in all patients. C pneumoniae and S pneumoniae together were associated with more severe disease and a longer stay in hospital.

CONCLUSIONS

Pneumonia caused by C pneumoniae was milder but clinically resembled that caused by S pneumoniae, and required hospital treatment even among young patients. Mixed infections were common and should be taken into account when planning antimicrobial treatment for community-acquired pneumonia. Further studies with more patients are needed to evaluate the severity of C pneumoniae pneumonia.

Continuous-monitoring blood culture screening system improves the detection of bacteremia in neutropenic patients

One reason for the underdiagnosis of bacteremia as an etiology of fever in neutropenic patients might lie in inefficient blood culture techniques. This possibility was investigated in a retrospective study by comparing the efficacies of a manual and an automated blood culture system used to detect bacteremia in such patients. All neutropenic fever episodes accompanying all 93 intensive chemotherapy cycles of 26 consecutive patients with acute myelogenous leukemia (AML) enrolled in Finnish Leukemia Group AML 86 trial and treated in Oulu University Hospital over 3 1/2 years were analyzed. The chemotherapy protocol and the supportive care of the patients remained the same during the whole period. In 1990-91 the blood cultures were made manually and in 1992-93 with an automated continuous-monitoring culture screening system. Evaluable febrile episodes numbered 53 during 1990-91 and 73 during 1992-93. There was a statistically significant increase (p < 0.05) of culture-positive episodes, from 21% to 40%, when the continuous-monitoring system was adopted. The new method proved to be better than the manual one in detecting bacteremia of neutropenic patients.

The etiology of community-acquired pneumonia among hospitalized patients during a Chlamydia pneumoniae epidemic in Finland

The etiology of community-acquired pneumonia during a Chlamydia pneumoniae epidemic was studied among 125 hospitalized patients. Etiologic investigations included blood and sputum cultures, pneumococcal antigen detection, and serologic investigations for common respiratory viruses and for Streptococcus pneumoniae, Haemophilus influenzae, Moraxella catarrhalis, Mycoplasma pneumococcal antigen detection, and serologic investigations for common and for Streptococcus pneumoniae, Haemophilus influenzae, Moraxella catarrhalis, Mycoplasma pneumoniae, and Chlamydia species. A specific microbial agent was identified in 110 patients (88%). Some 48% of the patients had mixed infections. S. pneumoniae was the most common pathogen (55%), followed by C. pneumoniae (43%). C. pneumoniae was found both as a single etiologic agent and as a mixed infection, most often with S. pneumoniae. In conclusion, S. pneumoniae is the most common cause of community-acquired pneumonia, even during a C. pneumoniae epidemic. The organism, alone or with other pathogens (especially S. pneumoniae), may cause community-acquired pneumonia that requires hospital treatment.

Attention related performance in two cognitively different subgroups of patients with multiple sclerosis

To evaluate the underlying mechanisms of cognitive decline in multiple sclerosis, two clinically and demographically matched multiple sclerosis groups differing in cognitive status were assessed with attention related tasks. In addition to the attention tests recommended by the Cognitive Function Study Group of the American National Multiple Sclerosis Society, a test of sustained attention was used to evaluate the role of possible fatigue on cognitive performance. The cognitively mildly deteriorated group was slower than the cognitively preserved group and the controls on all tests of attention. The mildly deteriorated group did not, however, consistently differ from the other groups in the error scores of the attention tests. The preserved group exhibited slowness at the end of the visual vigilance test, but no deficits were found on the other attention related tests in this group. It is suggested that dissociable kinds of processing slowness are the origin of the deficits found on the attention tests in the two multiple sclerosis groups. Our preserved group exhibited signs of motor and fatigue related slowness, whereas the mildly deteriorated group also had extensive cognitive slowness. As sensitive indicators of cognitive slowness, attentional tests should be included in evaluation of the cognitive status of patients with multiple sclerosis.

Automatic and controlled information processing in multiple sclerosis

The purpose of this study was to evaluate the kind of slowing of information processing associated with multiple sclerosis and how this possible slowness is related to cognitive deterioration. We selected 45 patients with definitive multiple sclerosis diagnosis and 35 control subjects. Twenty-two patients had mild cognitive deterioration and 23 patients had preserved cognitive capacities, otherwise the groups were matched. Using computerized tests, we investigated three separate stages of information processing: automatic and controlled processing, and motor programming. The results indicate that patients with mild cognitive deterioration are slower than patients with preserved capacities or controls in every stage of processing measured in this study. Additionally, the preserved patients showed signs of mild slowing in automatic visual processing. These results show that, in multiple sclerosis patients, widespread information processing slowness is associated with multiple sclerosis-related cognitive deterioration. This study emphasizes the importance of studying subgroups rather than cognitively heterogeneous patient samples and, furthermore, the need to divide information processing into different stages is indicated.

Evaluation of serological methods in the diagnosis of Chlamydia pneumoniae pneumonia during an epidemic in Finland

A complement fixation (CF) test, a micro-immunofluorescence (micro-IF) test and an enzyme immunoassay (EIA) using Re-lipopolysaccharide as antigen were compared in the diagnosis of chlamydial infection in 136 mainly elderly patients hospitalized with community-acquired pneumonia during a Chlamydia pneumoniae epidemic in Finland in 1986-1987. Chlamydial pneumonia was diagnosed in 58 (42.6%) of the 136 pneumonia patients; 44 (75.9%) of them could be shown by micro-IF to be caused by Chlamydia pneumoniae, three by Chlamydia psittaci and four by Chlamydia spp. Only 5 (11.4%) of 44 patients with Chlamydia pneumoniae pneumonia were IgM-positive, indicating that the majority of cases were reinfections. In this population of mainly elderly patients the CF test was insensitive, being positive in only 6 (10.3%) of 58 cases of chlamydial pneumonia. The EIA detected 72.4% of cases and micro-IF 87.9% of cases (including infections with Chlamydia pneumoniae, Chlamydia psittaci and Chlamydia spp.). In the EIA 77% of positive cases were positive in serum samples taken a week apart, whereas the corresponding figure for micro-IF was 50%. In micro-IF the measurement of IgA antibody levels is recommended and IgM-positive sera should be retested after removal of IgG antibody to avoid false-positive findings due to presence of rheumatoid factor. The collection of a third serum sample, for instance one month after onset, is also recommended, since half of the patients showed a diagnostic response in the micro-IF only in the sera taken one month apart.

On the nature of naming difficulties in aphasia

An extensive naming battery was administered to ten patients representing classical aphasia syndromes. The battery included traditional performance measures and error scoring, phonological cuing, multiple-choice tasks tapping semantic and phonological knowledge, and word repetition tests. Differences in the patients' performance profiles were interpreted as reflecting lexical-phonological, phoneme assembly or multiple deficits. The results suggest that the hypothesized naming deficits have complex relationships to classical aphasia syndromes.

Guillain-Barré syndrome and tularemia pleuritis with high adenosine deaminase activity in pleural fluid

A 56-year-old man suffered from prolonged fever, sore throat and cough, followed by pleural effusion and reversible progressive ascending muscle weakness. The condition fulfilled the diagnostic criteria of Guillain-Barré syndrome. Tuberculosis was initially suspected because of lymphocyte predominance and high adenosine deaminase activity in the pleural fluid. Later, an agglutination titer of 10,240 to Francisella tularensis antigen was found and an infected hare exposure could be identified. Thus, the activity of adenosine deaminase may be high also in tularemia pleuritis.

Candida immunity in patients undergoing surgical treatment for heart valve disease

The appearance of Candida antigen (Latex agglutination method), Candida antibodies (indirect immunofluorescence) and positive fungal cultures as well as the lymphocyte transformation response to Candida antigen "in vitro" was studied in a series of 37 successive patients before and after heart valve replacement. The Candida antigen test was positive preoperatively in 11/36 (31%) and postoperatively in 14/36 (39%) of the patients and in 2/200 (1%) of the controls (blood donors). The differences in the frequencies of positive tests between the patient group and the control group are significant (p less than 0.001). The lymphocyte response to Oidiomycin (Candida albicans) preoperatively was greater than the mean control value in 6/11 (54.5%) of the patients showing a positive Candida antigen test, but only in 4/25 (16.0%) of the patients who were Candida antigen negative. The total number of lymphocytes and the number of ANAE positive (T) cells as well as the lymphocyte response to Oidiomycin (OID), tuberculoprotein (PPD) and phytohaemagglutinin (PHA) decreased markedly postoperatively. Candida antibody titres were positive (greater than or equal to 1:128) in 3/37 (8%) of the postoperative patients and in 2/84 (2.4%) of the controls. This difference is not significant. Positive Candida antibody titres were found postoperatively in 15/37 (41%) of the patients, which is a significantly higher frequency than that seen preoperatively (p less than 0.005). More positive fungal cultures from throat specimens (p less than 0.005) were found in the patient group before surgery than in the control group (hospital personnel). After surgery the number of positive fungal cultures in these cases decreased (p less than 0.001) due to the use of oral antifungal prophylaxis with nystatin tablets.(ABSTRACT TRUNCATED AT 250 WORDS)

Airborne transmission of tularemia in farmers

In a tularemia epidemic during 1982 in northern Finland, 53 patients showed no peripheral portal of entry for infection or associated lymphadenopathy. Respiratory symptoms were observed in 72% of the patients. 26/38 cases had abnormal chest films. Hilar adenopathy was the most common finding (36%). Four patients did not receive antibiotics; 43 received tetracyclines, 5 streptomycin and 1 cefuroxime and amoxycillin. All patients recovered. 50 patients acquired the infection during common farming activities, such as making fresh hay with a hay-cutter, handling dry hay, threshing, etc. Thus, airborne transmission may be an important source of infection in normal farming activities in endemic areas of tularemia.

Amenorrhea with low normal thyroid function and thyroxine treatment

The effect of thyroxine treatment in cases of functional amenorrhea accompanied by low normally thyroid function was studied. During six months of follow-up, regular or single menstrual cycles were restored in ten of the 17 patients with thyroxine treatment and in four of the 11 patients without thyroxine treatment. During thyroxine treatment, thyroxine and free thyroxine index levels were elevated and serum testosterone levels decreased, but no significant changes were observed in serum estradiol, prolactin, follicle-stimulating hormone or luteinizing hormone levels. In the thyroid-releasing hormone/luteinizing-releasing hormone test, the thyroid-stimulating hormone response was markedly suppressed, but there were no changes in follicle-stimulating hormone, luteinizing hormone or prolactin responses. In one patient with primary hypothyroidism, regular menstrual cycles were restored and serum prolactin and thyroid-stimulating hormone levels normalized during thyroxine treatment. Thyroxine treatment seems to have benefits in some amenorrheic patients with low normal thyroid function.