Utilization of anonymization techniques to create an external control arm for clinical trial data

BACKGROUND

Subject-level real-world data (RWD) collected during daily healthcare practices are increasingly used in medical research to assess questions that cannot be addressed in the context of a randomized controlled trial (RCT). A novel application of RWD arises from the need to create external control arms (ECAs) for single-arm RCTs. In the analysis of ECAs against RCT data, there is an evident need to manage and analyze RCT data and RWD in the same technical environment. In the Nordic countries, legal requirements may require that the original subject-level data be anonymized, i.e., modified so that the risk to identify any individual is minimal. The aim of this study was to conduct initial exploration on how well pseudonymized and anonymized RWD perform in the creation of an ECA for an RCT.

METHODS

This was a hybrid observational cohort study using clinical data from the control arm of the completed randomized phase II clinical trial (PACIFIC-AF) and RWD cohort from Finnish healthcare data sources. The initial pseudonymized RWD were anonymized within the (k, ε)-anonymity framework (a model for protecting individuals against identification). Propensity score matching and weighting methods were applied to the anonymized and pseudonymized RWD, to balance potential confounders against the RCT data. Descriptive statistics for the potential confounders and overall survival analyses were conducted prior to and after matching and weighting, using both the pseudonymized and anonymized RWD sets.

RESULTS

Anonymization affected the baseline characteristics of potential confounders only marginally. The greatest difference was in the prevalence of chronic obstructive pulmonary disease (4.6% vs. 5.4% in the pseudonymized compared to the anonymized data, respectively). Moreover, the overall survival changed in anonymization by only 8% (95% CI 4-22%). Both the pseudonymized and anonymized RWD were able to produce matched ECAs for the RCT data. Anonymization after matching impacted overall survival analysis by 22% (95% CI -21-87%).

CONCLUSIONS

Anonymization may be a viable technique for cases where flexible data transfer and sharing are required. As anonymization necessarily affects some aspects of the original data, further research and careful consideration of anonymization strategies are needed.

Abstract 2378: Responses of AML patients to tailored drug regimens: monitoring cancer subclones by ultra-deep resequencing

As part of our individualized systems medicine (ISM) program, personalized treatment options are provided to clinicians based on in-depth genomic and molecular profiling as well as ex vivo drug sensitivity and resistance testing (DSRT) of leukemia patients (Pemovska et al. Cancer Discovery, 2013). In chemorefractory AML patients (n = 17), the ISM strategy has resulted in up to 35% response rate when individually selected targeted drugs have been applied in patient treatment. The responses achieved have, however, been transient and patients have typically relapsed quickly. Here, we aimed to understand the molecular basis of such treatment failures by quantitating the kinetics of individual cancer subclones before, during and after targeted treatments, as well as at the time of relapse and disease progression. Longitudinal serial samples from 13 AML patients were studied at multiple steps during leukemia progression and drug response. Clonal evolution of leukemic subclones was studied by both exome sequencing to get genome-wide overviews of disease progression, as well as by ultra-deep (>10,000x) amplicon resequencing with unique molecular identifiers to identify rare clones carrying specific cancer-relevant mutations.

Nine of the 13 patients (69%) had multiple clones by exome sequencing and displayed branching evolution. In five patients who received treatment with targeted inhibitors we observed a significant differential therapeutic response of the individual AML subclones during therapy. In some cases, this could be directly attributed to the molecular mechanisms of drug response and resistance, such as the loss of NF1 in a subclone leading to cytarabine resistance or the loss of the FLT3-positive subclone in a patient responding to sunitinib treatment. Despite a prominent drug response at the level of the subclone carrying the driver mutations, in all these patients a new subclone emerged that led to progression of the disease. In three of the patients, the dominant clone appearing at relapse was already detected as a minor subclone in the diagnostic sample by amplicon resequencing. Amplicon sequencing enabled us to detect these minor subclones (down to 0,5% frequency) that were missed by exome sequencing. The results suggest that relapses in AML may arise because the drug-resistant subclone exists already before the onset of therapy.

Overall, it is necessary to quantify tumor evolution and drug responses at the level of cancer subclones. Ultra-deep resequencing can be used to monitor drug responses at the subclone level, even at very low frequencies. This could facilitate early detection of small subclones with important prognostic implications, as well as the design of intelligent combinations of targeted drugs that could block such subclones.

Citation Format: Poojitha N Ojamies, Mika Kontro, Henrik Edgren, Pekka Ellonen, Sonja Lagstrom, Henrikki Almusa, Timo Miettinen, Samuli Eldfors, David Tamborero, Krister Wennerberg, Caroline Heckman, Kimmo Porkka, Maija Wolf, Olli Kallioniemi. Responses of AML patients to tailored drug regimens: monitoring cancer subclones by ultra-deep resequencing. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 2378.

Comparison of solution-based exome capture methods for next generation sequencing

Background

Techniques enabling targeted re-sequencing of the protein coding sequences of the human genome on next generation sequencing instruments are of great interest. We conducted a systematic comparison of the solution-based exome capture kits provided by Agilent and Roche NimbleGen. A control DNA sample was captured with all four capture methods and prepared for Illumina GAII sequencing. Sequence data from additional samples prepared with the same protocols were also used in the comparison.

Results

We developed a bioinformatics pipeline for quality control, short read alignment, variant identification and annotation of the sequence data. In our analysis, a larger percentage of the high quality reads from the NimbleGen captures than from the Agilent captures aligned to the capture target regions. High GC content of the target sequence was associated with poor capture success in all exome enrichment methods. Comparison of mean allele balances for heterozygous variants indicated a tendency to have more reference bases than variant bases in the heterozygous variant positions within the target regions in all methods. There was virtually no difference in the genotype concordance compared to genotypes derived from SNP arrays. A minimum of 11× coverage was required to make a heterozygote genotype call with 99% accuracy when compared to common SNPs on genome-wide association arrays.

Conclusions

Libraries captured with NimbleGen kits aligned more accurately to the target regions. The updated NimbleGen kit most efficiently covered the exome with a minimum coverage of 20×, yet none of the kits captured all the Consensus Coding Sequence annotated exons.

Whiplash injuries in Finland--the possibility of some sociodemographic and psychosocial factors to predict the outcome after one year

PURPOSE

The aim of our study was to evaluate if there was any relation between the change experienced in the condition of health or the length of the reported sick leaves after one year of whiplash injury and different sociodemographic and psychosocial factors.

METHOD

Our study design is a prospective 1-year-follow-up study. The material was collected in the year 1998 from neck injuries that had been caused by traffic accidents. The insurance companies sent a notice of the accident with medical certificate to the research team. After this we sent questionnaires to the injured and after one year of the accident a new inquiry was done. One hundred and eighty-two persons returned the 1-year-follow-up questionnaire which formed the material of this study.

RESULTS

The persons who had the lowest basic education and people over 60 years of age had more health problems after one year of the accident. The other sociodemographic and psychosocial factors had only limited prognostic value when we evaluated the experienced change of health one year after the whiplash injury. Only 71 persons reported that they had been on sick leave because of the whiplash injury and of them only 21 reported sick leave over 1 month.

CONCLUSIONS

Several sociodemographic and psychosocial factors can have relation to the deterioration of health experienced after whiplash injury but in this prospective study they proved to have only limited prognostic value in the long term symptoms with the exception of the education.

Age and origin of major Smith-Lemli-Opitz syndrome (SLOS) mutations in European populations

BACKGROUND

Smith-Lemli-Opitz syndrome (SLOS) (MIM 270 400) is an autosomal recessive multiple congenital anomalies/mental retardation syndrome caused by mutations in the Delta7-sterol reductase (DHCR7, E.C.1.3.1.21) gene. The prevalence of SLOS has been estimated to range between 1:15000 and 1:60000 in populations of European origin.

METHODS AND RESULTS

We have analysed the frequency, origin, and age of DHCR7 mutations in European populations. In 263 SLOS patients 10 common alleles (c.964-1G>C, p.Trp151X, p.Thr93Met, p.Val326Leu, p.Arg352Trp, p.Arg404Cys, p.Phe302Leu, p.Leu157Pro, p.Gly410Ser, p.Arg445Gln) were found to constitute approximately 80% of disease-causing mutations. As reported before, the mutational spectra differed significantly between populations, and frequency peaks of common mutations were observed in North-West (c.964-1G>C), North-East (p.Trp151X, p.Val326Leu) and Southern Europe (p.Thr93Met). SLOS was virtually absent from Finland. The analysis of nearly 8000 alleles from 10 different European populations confirmed a geographical distribution of DHCR7 mutations as reported in previous studies. The common Null mutations in Northern Europe (combined ca. 1:70) occurred at a much higher frequency than expected from the reported prevalence of SLOS. In contrast the most common mutation in Mediterranean SLOS patients (p.Thr93Met) had a low population frequency. Haplotypes were constructed for SLOS chromosomes, and for wild-type chromosomes of African and European origins using eight cSNPs in the DHCR7 gene. The DHCR7 orthologue was sequenced in eight chimpanzees (Pan troglodytes) and three microsatellites were analysed in 50 of the SLOS families in order to estimate the age of the three major SLOS-causing mutations.

CONCLUSIONS

The results indicate a time of first appearance of c.964-1G>C and p.Trp151X some 3000 years ago in North-West and North-East Europe, respectively. The p.Thr93Met mutations on the J haplotype has probably first arisen approximately 6000 years ago in the Eastern Mediterranean. Together, it appears that a combination of founder effects, recurrent mutations, and drift have shaped the present frequency distribution of DHCR7 mutations in Europe.

Pharmacokinetics of deramciclane and N-desmethylderamciclane after single and repeated oral doses in healthy volunteers

OBJECTIVE

To study the pharmacokinetics and accumulation of deramciclane and its metabolite N-desmethylderamciclane after 60 mg twice daily doses for 4 weeks.

METHODS

Sixteen healthy male subjects, age range of 20-29 years, participated in this randomized, double-blind, parallel-group, placebo-controlled study. Ten subjects first received a single 60 mg dose of deramciclane followed by 60 mg deramciclane b.i.d. between days 4 and 31. Six subjects received matching placebo in a similar manner. Pharmacokinetics of deramciclane and N-desmethylderamciclane were determined on days 1, 10, 17, 24 and 31. Plasma prolactin concentrations were measured before drug administration and 4 hours after on the same days. Safety was monitored using repeat laboratory determinations and ECG recordings.

RESULTS

The mean (SD) AUC(0-infinity) of deramciclane was 1,251 (385) ng x h/ml after the first dose. The AUC(tau) calculated for the dosing interval was significantly higher at week 1 (p = 0.048) than the AUC(0-infinity) after the first dose but thereafter there was no further accumulation of deramciclane. The mean accumulation indices at weeks 1, 2, 3 and 4 varied between 2.3 and 2.7 with no tendency to increase over time. The mean apparent elimination half-life of deramciclane was 24.9 (3.5) hours after the first dose and 29.3 (9.3) hours after 4-week repeated dosing; this difference was not statistically significant. The accumulation index of N-desmethylderamciclane increased from week 1 to week 2 but remained stable thereafter. The treatment was well tolerated. Plasma prolactin levels were not influenced by deramciclane administration.

CONCLUSIONS

Deramciclane administration, 60 mg twice daily for 4 weeks to healthy male volunteers, is well tolerated, and there is no evidence of continuous accumulation of the drug during maintenance treatment. Deramciclane at a dose of 60 mg b.i.d. does not antagonize dopamine receptors to a significant degree.

Segmental duplications flank the multiple sclerosis locus on chromosome 17q

Large chromosomal rearrangements, duplications, and inversions are relatively common in mammalian genomes. Here we report interesting features of DNA strands flanking a Multiple Sclerosis (MS) susceptibility locus on Chromosome 17q24. During the positional cloning process of this 3-Mb locus, several markers showed a radiation hybrid clone retention rate above the average (1.8-fold), suggestive for the existence of duplicated sequences in this region. FISH studies demonstrated multiple signals with three of the tested regional BACs, and 24 BACs out of 187 showed evidence for duplication in shotgun sequence comparisons of the 17q22-q24 region. Specifically, the MS haplotype region proved to be flanked by palindromic sequence stretches and by long segmental intrachromosomal duplications in which highly homologous DNA sequences (>96% identity) are present at both ends of the haplotype. Moreover, the 3-Mb DNA segment, flanked by the duplications, is inverted in the mouse genome when compared with the orientation in human and chimp. The segmental duplication architecture surrounding the MS locus raises the possibility that a nonallelic homologous recombination between duplications could affect the biological activity of the regional genes, perhaps even contributing to the genetic background of MS.

Robust denoising of electrophoresis and mass spectrometry signals with minimum description length principle

The need for high-throughput assays in molecular biology places increasing requirements on the applied signal processing and modelling methods. In order to be able to extract useful information from the measurements, the removal of undesirable signal characteristics such as random noise is required. This can be done in a quite elegant and efficient way by the minimum description length (MDL) principle, which treats and separates 'noise' from the useful information as that part in the data that cannot be compressed. In its current form the MDL denoising method assumes the Gaussian noise model but does not require any ad hoc parameter settings. It provides a basis for high-speed automated processing systems without requiring continual user interventions to validate the results as in the conventional signal processing methods. Our analysis of the denoising problem in mass spectrometry, capillary electrophoresis genotyping, and sequencing signals suggests that the MDL denoising method produces robust and intuitively appealing results sometimes even in situations where competing approaches perform poorly.

Whiplash injuries in Finland: the situation 3 years later

The aim of this study was to define the influence of whiplash injuries on the perceived condition of health 3 years after injury. We evaluated remaining symptoms and the use of health services. Insurance companies provided reports and medical certificates from traffic accidents in Finland in 1998, for those injured who had agreed to take part in the study. Participants in the 1-year follow-up study answered a self-report questionnaire. Three years after the whiplash-causing accident, 11.8% of participants reported that injury symptoms had caused their health to deteriorate significantly as compared with before the accident. Neck pain was the most common single symptom, reported by 14.6% of respondents. The severity of the initial symptoms according to the WAD classification is reflected in the subject's self-perception of health after 3 years. A remarkable 10-17% of respondents still used health services regularly because of the symptoms. Although some of the injured had improved in the long term, some reported that their health condition was worse after 3 years than at the 1-year follow-up. The percentage of respondents reporting a significant health deterioration remains unchanged 3 years after the whiplash injury. These findings illuminate the importance of early recognition of risk factors for long-term disability and the primary treatment and rehabilitation procedures.

The possibility to use simple validated questionnaires to predict long-term health problems after whiplash injury

STUDY DESIGN

A prospective follow-up study.

OBJECTIVES

To evaluate the relation of the state of health before the accident and the significance of the symptoms reported soon after the injury to the situation 3 years after the injury. To evaluate the possibility of using simple validated questionnaires to predict long-term health problems after the injury.

SUMMARY OF BACKGROUND DATA

A whiplash injury is generally benign in its natural course. However, some of the patients have diverse and prolonged symptoms. Although several prognostic factors have been suggested for the poor recovery, in most cases the factors leading to prolonged disability remain unclear.

METHODS

In collaboration with traffic insurance companies, we gathered information of neck injuries that occurred in traffic accidents in Finland in 1998. After the insurance company received a notification of a neck injury and consent from the injured party to participate in the study, they sent the information to the research team. The first inquiry was sent to the patients as soon as possible. One- and three-year follow-up questionnaires were posted to those who responded to the first inquiry. A total of 144 persons returned the 3-year follow-up questionnaires and form the material of this study. RESULTS A poor state of health or frequent neck pain or headache before the accident did not have any significant relation to the poor outcome 3 years after the accident. The extent of neck pain and lower back pain reported soon after the accident was significantly associated to a poor outcome in the follow-up. The Neck Disability Index questionnaire was significantly related to the poor outcome after 3 years.

CONCLUSIONS

The subjective experience of a notably decreased level of activity because of the neck pain when supplemented by the enhanced score of Neck Disability Index questionnaire predicts well poor outcome in long-term follow-up and can be used as a tool to identify persons who are at risk to suffer long-term health problems after whiplash injury.

Whiplash injuries in Finland: a prospective 1-year follow-up study

OBJECTIVES

The aim of the study was to define how many whiplash injuries occur in Finland in traffic accidents and the degree of severity of these injuries using the whiplash-associated disorders (WAD) classification presented by the Quebec Task Force, and to define possible long-term health effects caused by whiplash injury as well as the duration of whiplash-associated sick-leaves.

METHODS

This was a prospective one-year-follow-up study. Fourteen insurance companies paving compensations for traffic accidents in Finland sent the accident reports and medical certificates of all neck injuries attributable to traffic accidents to the research team. The material was collected from neck injuries that had occurred in traffic accidents during the year 1998.

RESULTS

The majority of those suffering a whiplash injury were women. On the basis of the WAD classification, most whiplash injuries were mild, belonging to grades WAD I and II. At one year from the accident nearly 10% considered that their health had been impaired significantly as a result of their neck injury. Over 10% of those questioned had been on sick-leave for over a month but only 1.5% had been on sick-leave associated with the injury for more than 6 months. The most common symptom after one year was neck pain or neck pain combined with headache and symptoms in the upper extremities. No major changes related to the seasons of the year were found.

CONCLUSIONS

The number of reported neck injuries in proportion to all traffic accidents involving physical injuries is small, even in proportion to rear-end collisions. In a considerable proportion of collision patients, whiplash injury does result in significant impairment which can last as long as a year after the accident. The WAD classification predicts the duration of work disability and the long-term health damage caused by the injury. Since the appearance of symptoms and the individual need for rehabilitation due to impaired functional capacity do not depend solely on the tissue damage and biomechanical forces involved in the collision, in the future it will be important to determine which factors are responsible for the differences in coping after a collision.

Follow-up study of patients randomized in the Scandinavian simvastatin survival study (4S) of cholesterol lowering

The Scandinavian Simvastatin Survival Study (4S) and other randomized clinical trials have demonstrated that cholesterol-lowering treatment with statins improves prognosis in patients with coronary atherosclerosis compared with placebo. The effect of therapy with statins beyond the typical 5 to 6 years' duration of the trials, in particular regarding the risk of cancer, has not been investigated. This study examines the long-term effects of simvastatin for up to 8 years on cause-specific mortality in patients with coronary heart disease (CHD). We performed an observational, government registry-based study of mortality in the groups originally randomized to simvastatin or placebo in the 4S over an additional 2-year follow-up period, so that the median total follow-up period was 7.4 years (range 6.9 to 8.3 in surviving patients). Randomization took place at outpatient clinics at 94 clinical centers in Denmark, Finland, Iceland, Norway, and Sweden from 1988 to 1989. Of 4,444 patients with CHD, 2,223 and 2,221 were randomized to treatment with placebo or simvastatin therapy, respectively. Patients received treatment with simvastatin, starting at 20 mg/day, with titration to 40 mg/day at 12 or 24 weeks if total cholesterol was >5.2 mmol/L (200 mg/dl), or placebo. After the double-blind period, most patients in both treatment groups received simvastatin as open-label prescription. Of the 1,967 patients originally treated with placebo and surviving the double-blind period, 97 (4.9%) died during the following 2 years. In the group randomized to simvastatin the corresponding number was 74 of the 2, 039 survivors (3.6%). Adding these deaths to those occurring during the original trial, the total was 353 (15.9%) and 256 (11.5%) deaths in the groups originally randomized to placebo and simvastatin, respectively. The relative risk was 0.70 (95% confidence interval 0. 60 to 0.82, p = 0.00002). The total number of cancer deaths was 68 (3.1%) in the placebo group and 52 (2.3%) in the simvastatin group (relative risk 0.73, 95% confidence interval 0.51 to 0.05, p = 0. 087), and the numbers of noncardiovascular and other deaths were similar in both groups. We therefore conclude that treatment with simvastatin for up to 8 years in patients with CHD is safe and yields continued survival benefit.

Lipoprotein changes and reduction in the incidence of major coronary heart disease events in the Scandinavian Simvastatin Survival Study (4S)

BACKGROUND

The Scandinavian Simvastatin Survival Study (4S) randomized 4444 patients with coronary heart disease (CHD) and serum cholesterol 5.5 to 8.0 mmol/L (213 to 310 mg/dL) with triglycerides < or =2.5 mmol/L (220 mg/dL) to simvastatin 20 to 40 mg or placebo once daily. Over the median follow-up period of 5.4 years, one or more major coronary events (MCEs) occurred in 622 (28%) of the 2223 patients in the placebo group and 431 (19%) of the 2221 patients in the simvastatin group (34% risk reduction, P<.00001). Simvastatin produced substantial changes in several lipoprotein components, which we have attempted to relate to the beneficial effects observed.

METHODS AND RESULTS

The Cox proportional hazards model was used to assess the relationship between lipid values (baseline, year 1, and percent change from baseline at year 1) and MCEs. The reduction in MCEs within the simvastatin group was highly correlated with on-treatment levels and changes from baseline in total and LDL cholesterol, apolipoprotein B, and less so with HDL cholesterol, but there was no clear relationship with triglycerides. We estimate that each additional 1% reduction in LDL cholesterol reduces MCE risk by 1.7% (95% CI, 1.0% to 2.4%; P<.00001).

CONCLUSIONS

These analyses suggest that the beneficial effect of simvastatin in individual patients in 4S was determined mainly by the magnitude of the change in LDL cholesterol, and they are consistent with current guidelines that emphasize aggressive reduction of this lipid in CHD patients.

Safety and tolerability of cholesterol lowering with simvastatin during 5 years in the Scandinavian Simvastatin Survival Study

BACKGROUND

Long-term safety is an important consideration in the selection and use of drugs, such as lipid-lowering agents, that are prescribed to reduce the risk of clinical events during long periods.

METHODS

The Scandinavian Simvastatin Survival Study was designed to evaluate the effects of cholesterol lowering with simvastatin on mortality and morbidity in patients with coronary heart disease. The 4444 patients aged 35 to 70 years (mean, 58.9 years) with angina pectoris or previous myocardial infarction and serum cholesterol levels of 5.5 to 8.0 mmol/L (213-310 mg/dL) receiving a lipid-lowering diet were randomly assigned to take double-blind treatment with simvastatin, 20 to 40 mg once daily, or placebo. In addition to previously reported end-point events, detailed clinical and laboratory safety data were collected during a median follow-up period of 5.4 years (range in survivors, 4.9-6.2 years).

RESULTS

The only clearly drug-related serious adverse event during the 5.4-year median follow-up period was a single reversible case of myopathy. The frequencies of persistent elevations of hepatic aminotransferase levels above 3 times the upper limit of normal and of nonviral hepatitis in the simvastatin and placebo treatment groups were not significantly different. Examination of the lens showed no between-group differences, and no previously unrecognized adverse effects of the drug were observed. There were no significant between-group differences in adverse events in any body system. In particular, the frequency of adverse events related to the central nervous system was similar in both groups.

CONCLUSION

The safety profile of simvastatin, 20 to 40 mg daily, over 5 years was excellent.

Cholesterol lowering and the use of healthcare resources. Results of the Scandinavian Simvastatin Survival Study

BACKGROUND

Advances in the treatment of cardiovascular disease have increased costs; annual cardiovascular healthcare expenditure in the United States currently exceeds $100 billion. Physicians and third-party payers need to assess the economic impact of treatments that reduce cardiovascular morbidity and mortality.

METHODS AND RESULTS

The Scandinavian Simvastatin Survival Study is a randomized, double-blind, placebo-controlled trial in which simvastatin reduced the risk of death by 30% (P=.0003) over the median follow-up period of 5.4 years in patients with previous myocardial infarction or stable angina pectoris as a result of a 42% reduction in the risk of coronary deaths (P=.00001). In the present report, data prospectively collected from hospital admissions were analyzed to evaluate the impact of simvastatin on healthcare resource use and perform a cost-minimization analysis. In the placebo group (n=2223), there were 1905 hospitalizations (average duration, 7.9 days) for acute cardiovascular events or coronary revascularization procedures among 937 patients, whereas in the simvastatin group (n=2221), there were 1403 such hospitalizations (average duration, 7.1 days) among 720 patients (all differences, P<.0001). The corresponding number of hospital days was 15089 and 9951 in the two groups, respectively (34% reduction,P<.0001). In the United States, the resulting reduction in hospitalization costs over the 5.4 years of the trial would be $3872 per patient, reducing the effective cost of simvastatin by 88% to $0.28 per day.

CONCLUSIONS

In addition to reducing mortality and morbidity in coronary heart disease patients, simvastatin markedly reduces use of hospital services, thus offsetting most of its cost.

Ursodeoxycholic acid treatment lowers the serum level of antibodies against pyruvate dehydrogenase and influences their inhibitory capacity for the enzyme complex in patients with primary biliary cirrhosis

A two-year randomized, double-blind, placebo-controlled clinical trial used paired serum samples from 122 patients with primary biliary cirrhosis to compare the effect of ursodeoxycholic acid and colchicine on their immune parameters. IgG antibodies to pyruvate dehydrogenase, the major autoantigen in primary biliary cirrhosis, were determined by enzyme-linked immunosorbent assay and immunoblot; enzyme inhibition assay against pyruvate dehydrogenase was used to test the changes of the functional reactivity of the serum autoantibodies. Treatment with ursodeoxycholic acid decreased both the level of IgG antibodies to pyruvate dehydrogenase (P < 0.01) and the inihibitory titer of the sera for pyruvate dehydrogenase (P < 0.01). Treatment with colchicine or placebo showed no statistically significant changes in either the antibody levels or the inhibitory titers. Ursodeoxycholic acid thus alters the immune parameters of patients with primary biliary cirrhosis. The mechanism of these changes needs further investigation.

Duration of induction melting of cobalt-chromium alloy and its effect on resistance to deflection fatigue of cast denture clasps

This study determined the effect of various durations of induction melting of a cobalt-chromium alloy on resistance to deflection fatigue. Commercial cobalt-chromium alloy was melted by high-frequency induction for various lengths of time before it was cast into the shape of a denture clasp. The test method used was a constant-deflection fatigue test. The fatigue fracture surface of the clasp was examined with a scanning electron microscope, and the surface hardness (Vickers hardness) of the clasps was measured. In clasps with greater fatigue resistance scanning electron microscope photomicrographs revealed a coarse grain structure. The surface hardness of the alloy was least in the group with the lowest fatigue resistance and was higher in groups with greater fatigue resistance. This study suggests that, although some porosities are formed in the middle of the clasps after the alloy is overheated, the fatigue resistance of cobalt-chromium alloy denture clasps can be increased by lengthening the induction melting period of the alloy.

Serum placental protein 14 concentrations are similar in the first trimester pregnancies of women after pituitary down-regulation with a gonadotrophin-releasing hormone agonist and normal cycles with frozen embryo transfers

Previous studies suggest that, in pregnancies after in-vitro fertilization (IVF) and embryo transfer following pituitary down-regulation with a gonadotrophin-releasing hormone analogue (buserelin) and ovulation induction with human gonadotrophins, the serum placental protein 14 (PP14) concentration is lower than in normally conceived pregnancies. We studied serum PP14 concentrations in two groups of women: (i) in 17 infertile women whose pregnancy followed IVF and embryo transfer using buserelin (long protocol) and human menopausal gonadotrophin for ovulation induction; (ii) in 15 women whose pregnancy followed transfer of frozen-thawed embryos. Similar PP14 concentrations were found in both groups on days 9-10, 14-15 and 70-77 after human chorionic gonadotrophin administration (buserelin, IVF/embryo transfer) or spontaneous luteinizing hormone surge (frozen-thawed embryo transfer). Our results show that PP14 secretion is not compromised by pituitary down-regulation with buserelin in infertile women with functional ovaries.

Comparison of effects on sleep of lovastatin and pravastatin in hypercholesterolemia

The effects on sleep of lovastatin, a 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitor administered as a lipophilic lactone prodrug, and pravastatin, an inhibitor administered in its active, hydrophilic, open-acid form, were compared by polysomnographic sleep monitoring. Twenty-four men with primary hypercholesterolemia (low-density lipoprotein 4 to 7 mmol/liter) each received 2 of the following 3 treatments in a randomized, incomplete block, crossover design study: lovastatin (40 mg/day), pravastatin (40 mg/day), and placebo. Test drug was administered once daily for 4 weeks during each half of the crossover study. Subjective sleep assessments were obtained throughout each treatment period, and polysomnographic recordings were obtained at the end of the 4-week treatment periods. Treatment periods were separated by a 1-week washout. Lovastatin did not differ from placebo regarding any polysomnographic parameter except "number of entries to wake," for which it produced fewer entries (i.e., change was in the direction of improvement). Pravastatin did not differ from placebo regarding any polysomnographic measures, but was associated with worsening in relation to lovastatin in the following parameters: sleep efficiency, entries to wake, percent rapid eye movement sleep, wake time during sleep, and total wake time. For each of these 4 parameters, although neither drug showed marked differences from placebo, the mean change in the lovastatin group was in the direction of improved sleep, whereas the change in the pravastatin group was in the direction of disturbed sleep. Neither lovastatin nor pravastatin had any effect on subjective, qualitative sleep ratings.(ABSTRACT TRUNCATED AT 250 WORDS)

Pravastatin and gemfibrozil alone and in combination for the treatment of hypercholesterolemia

PURPOSE

To compare the efficacy and safety of pravastatin, gemfibrozil, combined therapy, and placebo in the treatment of hypercholesterolemia.

PATIENTS AND METHODS

At 5 centers in Sweden and 2 in Finland, 290 ambulatory patients were randomized to active treatment or placebo for 12 weeks following a single-blind placebo lead-in period. The study was double-blind and placebo-controlled. Patients has plasma total cholesterol levels of at least 6.0 mmol/L or in the 90th percentile by age and sex and triglycerides less than 4.0 mmol/L. Concentrations of lipids, lipoproteins, and apolipoproteins were measured, and clinical laboratory tests included liver function and creatine kinase determinations.

RESULTS

Pravastatin reduced total cholesterol (26.3% versus 15.2%, p < or = 0.01), low-density lipoprotein cholesterol (LDL-C) (33.5% versus 16.8%, p < or = 0.01), and apolipoprotein B (28.8% versus 15.3%, p < or = 0.01) more than gemfibrozil. Gemfibrozil reduced very-low-density lipoprotein cholesterol (VLDL-C) (49.1% versus 21.9%, p < or = 0.01) and triglycerides (42.2% versus 14.2%, p < or = 0.01) and increased high-density lipoprotein cholesterol (HDL-C) (15.2% versus 5.9%, p < or = 0.01) more than pravastatin. Pravastatin and gemfibrozil increased apolipoprotein A-I comparably (3.3% versus 5.0%, p = NS). The combination significantly (p < or = 0.01) reduced total cholesterol (29.0%), LDL-C (37.1%), VLDL-C (49.4%), and apolipoprotein B (31.6%), and increased HDL-C (16.8%). The combination reduced the total cholesterol/HDL-C (39.3%) and LDL-C/HDL-C (45.8%) ratios significantly (p < 0.01). Adverse events and clinical laboratory abnormalities were generally mild and transient in all groups, although creatine kinase tended to be higher with combination therapy. Study drugs were withdrawn from two patients with asymptomatic creatine kinase elevations. Severe myopathy was not observed; however, the presence of subclinical musculoskeletal effects cannot be excluded.

CONCLUSIONS

Co-administration of pravastatin and gemfibrozil combined the specific effects of the two drugs on lipoprotein concentrations and ratios. The incidence of side effects was low; severe myopathy did not occur. The combination may be useful in selected cases of combined hyperlipidemia; however, since myopathy at a low incidence or after long-term therapy cannot be excluded, the routine use of combination therapy is not advisable.

Hemorrhagic gastropathy in epidemic nephropathy

A patient with epidemic nephropathy (NE) and with gastrointestinal symptoms and hemorrhagic gastropathy prompted us to study further 10 consecutive patients with NE. Gastroscopy was carried out within 1 to 4 weeks after the beginning of the symptoms, and in every case a hemorrhagic gastropathy was observed. Hemorrhagic lesions were more marked, the shorter the elapsed time interval from the beginning of symptoms. Hemorrhagic changes were always more prominent in the proximal than in the distal part of the stomach. In 7 of 10 patients lesions were also observed in the duodenum. Colonoscopy was done in one patient and it showed similar spotty hemorrhages, suggesting that hemorrhagic lesions were not limited to the gastroduodenal mucosa only. Histological studies disclosed that the hemorrhagic lesions were associated with edema in the lamina propria, but without inflammatory changes. Follow-up gastroscopy in three patients 3 to 8 weeks later showed disappearance of hemorrhagic lesions in every patient. Thus, these results show for the first time that hemorrhagic gastropathy is a common finding in NE, and it may explain the abdominal symptoms and gastrointestinal bleeding in some of these patients. However, the mechanism of the hemorrhagic lesions needs further exploration.

Alpha 2-adrenoceptor density in forebrain areas of Zucker rats: no effect of genetic obesity or antiglucocorticoid treatment

The density of alpha 2-adrenoceptors was determined in different forebrain regions of lean and obese Zucker rats by para-[125I]iodoclonidine ([125I]PIC) receptor autoradiography. No significant differences were observed between the Zucker phenotypes in the density of alpha 2-adrenoceptors in any brain areas examined. Four days treatment with the antiglucocorticoid mifepristone (RU 38486) did not affect [125I]PIC-binding. It is concluded that the hyperphagia and abnormal corticosterone secretion of genetically obese Zucker rats do not appear to be associated with changes in alpha 2-adrenoceptor density in brain.

Low prevalence of hepatitis C antibodies in chronic liver disease in Finland

High prevalence of hepatitis C antibodies (anti-HCV) have been found in the Middle- and Southern European countries in connection with chronic liver diseases. In a study of Finnish chronic liver disease patients no anti-HCV antibodies were found in 22 autoimmune chronic active hepatitis, in 5 chronic persistent hepatitis and in 38 alcoholic liver disease patients. 2/30 primary biliary cirrhosis patients were anti-HCV positive. As a comparison 3/9 patients with acute community acquired non-A non-B hepatitis and 28/48 i.v. drug addicts had anti-HCV antibodies. The results indicate that HCV infections in Finnish chronic hepatitis patients are rare.

Identification of a deletion in the LDL receptor gene. A Finnish type of mutation

A cDNA probe for the low density lipoprotein (LDL) receptor gene was used to screen DNA samples from 52 unrelated Finnish patients with the heterozygous form of familial hypercholesterolemia (FH) and 51 healthy controls. Southern blot analysis using the restriction enzyme PvuII revealed an abnormal 11 kb (kilo base-pair) restriction fragment in 16 (31%) of the patients but none of the controls. A more detailed restriction enzyme analysis of the DNA from patients revealed a mutation which apparently is due to an 8 kb deletion extending from intron 15 to exon 18 of the LDL receptor gene. Co-segregation of FH with the mutated gene was demonstrated in three families. These data are consistent with a 'founder gene effect' and support the assumption that recombinant DNA methods may have great impact on the diagnostics of FH in genetically homogeneous populations.

Correlation between serum levels of some cholesterol precursors and activity of HMG-CoA reductase in human liver

The possibility that the serum concentrations of various cholesterol precursors may reflect the activity of the hepatic HMG-CoA reductase was investigated in humans under different conditions. The serum levels of squalene, free and esterified lanosterol, (4 alpha, 4 beta, 14 alpha-trimethyl-5 alpha-cholest-8, 24-dien-3 beta-ol), two dimethylsterols (4 alpha, 4 beta-dimethyl-5 beta-cholest-8-en-3 beta-ol and 4 alpha, 4 beta-dimethyl-5 alpha-cholest-8, 24-dien-3 beta-ol), two methostenols (4 alpha-methyl-5 alpha-cholest-7-en-3 beta-ol and 4 alpha-methyl-5 alpha-cholest-8-en-3 beta-ol), two lathosterols (5 alpha-cholest-7-en-3 beta-ol and 5 alpha-cholest-8-en-3 beta-ol) and desmosterol (cholest-5, 24-dien-3 beta-ol) were measured in untreated patients (n = 7) and patients treated with cholestyramine (QuestranR, 8 g twice daily for 2-3 weeks, n = 5) or chenodeoxycholic acid (15 mg/kg body weight daily for 3-4 weeks, n = 8) prior to elective cholecystectomy. The activity of the hepatic microsomal HMG-CoA reductase was measured in liver biopsies taken in connection with the operation.(ABSTRACT TRUNCATED AT 250 WORDS)

Lack of correlation between serum dopamine-beta-hydroxylase activity and blood pressure in middle-aged men

The activity of serum dopamine-beta-hydroxylase (DBH) was measured in 1194 asymptomatic middle-aged men with diastolic blood pressure ranging from 75 to 125 mm Hg during the baseline examination of a multifactorial intervention program for primary prevention of coronary heart disease. No correlation was present between serum DBH activity and systolic (r = -0.01, NS) or diastolic (r = +0.02, NS) blood pressure. No significant differences in serum DBH activity was observed between individuals with blood pressure in the lower, middle or upper deciles. Serum DBH activity was similar in subjects with normal blood pressure, in individuals with widely fluctuating blood pressure and in patients with fixed hypertension. The results suggest that serum DBH activity cannot be used as an aid in the diagnosis of essential hypertension of middle-aged men.