First-trimester screening in pregnancies conceived by assisted reproductive technology: significance of gestational dating by oocyte retrieval or sonographic measurement of crown-rump length

OBJECTIVES

To evaluate, in pregnancies conceived by assisted reproductive technology, whether determination of gestational age (GA) by date of oocyte aspiration (DOA) or crown-rump length (CRL) at first-trimester screening influences the distribution of serum and sonographic markers or the performance of first-trimester screening for chromosomal abnormalities.

METHODS

GA was calculated using either DOA or CRL at blood sampling and nuchal translucency thickness (NT) measurement in 729 singleton pregnancies conceived by in-vitro fertilization (IVF) or intracytoplasmic sperm injection (ICSI). Weight-corrected log multiples of the median (MoM) marker distributions specific for IVF pregnancy were established using multiple log regression and compared for DOA- and CRL-based GA calculation.

RESULTS

GA determined by CRL was significantly larger, albeit slightly, than was GA determined by DOA, with a mean difference of 1.50 (SD, 2.4) days (P < 0.001). Log MoM distributions of free beta-human chorionic gonadotropin and NT showed that GA dating by CRL resulted in significantly higher, albeit slightly, mean log MoM values compared with DOA dating. The reverse was the case for mean log MoM pregnancy-associated plasma protein-A. The SDs were similar for CRL and DOA dating. According to Monte Carlo simulation, the use of DOA or CRL for GA dating did not appreciably influence the performance of first-trimester screening.

CONCLUSIONS

DOA and CRL are practically equivalent when calculating GA for first-trimester screening. The correct method of GA dating for other purposes (e.g. estimated time of delivery) in IVF/ICSI pregnancies is still unresolved.

Idiopathic restrictive cardiomyopathy in children is caused by mutations in cardiac sarcomere protein genes

BACKGROUND

Restrictive cardiomyopathy (RCM) is rare in childhood, but has a grave prognosis. The cause of disease in most cases is unknown.

OBJECTIVE

To determine the prevalence of sarcomere protein gene mutations in children with idiopathic RCM.

METHODS

Twelve patients (9 female, mean age 5.1 years) with idiopathic RCM referred between 1991 and August 2006 underwent detailed clinical and genetic evaluation. Nine had received cardiac transplants at the time of the study. The entire coding sequences of the genes encoding eight cardiac sarcomere proteins and desmin were screened for mutations. Familial evaluation was performed on first-degree relatives.

RESULTS

Four patients (33%) had a family history of cardiomyopathy: RCM (n = 2); dilated cardiomyopathy (n = 1) and left ventricular non-compaction (n = 1). Sarcomere protein gene mutations were identified in four patients (33%): 2 in the cardiac troponin I gene (TNNI3) and 1 each in the troponin T (TNNT2) and alpha-cardiac actin (ACTC) genes. Two were de novo mutations and 3 were new mutations. All mutations occurred in functionally important and conserved regions of the genes.

CONCLUSIONS

Sarcomere protein gene mutations are an important cause of idiopathic RCM in childhood. We describe the first mutation in ACTC in familial RCM. The identification of RCM in a child should prompt consideration of sarcomere protein disease as a possible cause and warrants clinical evaluation of the family.

Pregnancy-associated plasma protein A in a large cohort of Type 1 diabetic patients with and without diabetic nephropathy-a prospective follow--up study

AIM

Pregnancy-associated plasma protein A (PAPP-A) has been implicated in the aetiology of acute coronary syndromes and carotid and peripheral artherosclerosis. Diabetic nephropathy is characterized by increased cardiovascular risk. We investigated the prognostic value of PAPP-A in a large cohort of Type 1 diabetic patients.

METHODS

In a prospective observational follow-up study, 197 Type 1 diabetic patients with diabetic nephropathy and a matched group of 178 patients with normoalbuminuria were followed for 10.1 (0-10.3) years. PAPP-A was determined at baseline.

RESULTS

In patients with diabetic nephropathy, plasma PAPP-A was elevated 3.6 (0.4-51.1) mIU/l [median (range)] vs. 2.1 (0.4-46.6) mIU/l in normoalbuminuric patients, P < 0.0001. For acute coronary syndromes, a PAPP-A threshold of 10 mIU/l has been suggested. Thirty-seven patients were above the threshold and of these 13 patients (35%) died, compared with 60 of 338 patients (18%) below the threshold; log rank test P = 0.007. PAPP-A significantly predicted mortality after adjustment for presence of nephropathy; hazard ratio for dying when PAPP-A was above the threshold 2.1 (95% CI 1.13-3.9); P = 0.019. After adjusting for traditional risk factors, the results were attenuated. When only patients with nephropathy were analysed, PAPP-A was significantly predictive of all-cause mortality [P = 0.008; 2.43 (1.26-4.67)] in unadjusted analysis. After adjustment, the predictive value of PAPP-A for all-cause mortality was attenuated (P = 0.064).

CONCLUSION

We find PAPP-A to be associated with increased mortality in Type 1 diabetic patients with nephropathy in unadjusted analysis. After adjustment for traditional risk factors, the prognostic value of PAPP-A was no longer significant.

Mannan-binding lectin is a determinant of survival in infective endocarditis

Mannan-binding lectin (MBL) is a collectin plasma protein activating the lectin pathway of the complement system, enhancing opsonophagocytosis and modulating the cytokine response to inflammation. Deficiency of MBL, caused by structural mutations or promoter polymorphisms in the MBL2 gene, has been associated with increased susceptibility to infection and autoimmune disease. Thus, as infective endocarditis remains a severe disease requiring intensive and long-term treatment with antibiotics, we examined whether there was an association between MBL and clinical outcome in 39 well-characterized patients with infective endocarditis. Five patients (13%) had MBL concentrations < 100 microg/l and were considered MBL-deficient. This proportion was similar to that in a healthy control group of blood donors. Mortality 3 months after diagnosis was 20% in patients with MBL-deficiency and 9% in patients with normal MBL. The 5-year mortality was 80% and 25%, respectively. MBL-deficiency was on univariate survival statistics associated with significantly higher mortality on follow-up (P=0 x 03). In conclusion, this is the first report of an association between MBL-deficiency and survival in infective endocarditis. The present observation is important, as replacement therapy in MBL-deficient patients is possible. For certain high-risk subgroups, it opens new perspectives for improvement of treatment and outcome in infective endocarditis.

Expression and prognostic significance of Tetranectin in invasive and non-invasive bladder cancer

Tetranectin (TN) is a plasminogen kringle-4 binding protein that can be detected in the plasma and the extracellular matrix. In malignancies, TN is thought to enhance proteolytic processes enabling tumor cells to invade and metastasize. So far, TN expression has not been described in transitional cell bladder cancer (TCC), and there is no information on the prognostic significance of its in situ expression. TN expression was studied in 99 TCC patients diagnosed between 1994 and 1997. Immunohistochemistry was performed on a tissue microarray using a monoclonal antibody against TN (clone 11F1). Within the mean follow-up period of 60 months, pTa and pT2-4 TCC patients with stainable TN in the tumor stroma had a significant shorter recurrence-free survival and higher risk of recurrence compared to those without stainable TN (p = 0.0002 for both). TN expression in the tumor cells did not influence recurrence-free survival. In conclusion, TN is expressed in a subgroup of bladder cancer patients with a higher risk of recurrence who may take benefit from a closer follow-up.

The association between apolipoprotein E and multiple sclerosis

The article is a complete literature study that investigates the association between apolipoprotein E (Apo E) and multiple sclerosis (MS). Apo E is an important factor in transport, uptake, and redistribution of cholesterol, which is significant to remodelling and repair of nerve tissue. Apo E is involved in neurodegenerative diseases and the most well known association is between Apo epsilon4 and Alzheimer's disease. Only one study found that homozygosity for Apo epsilon4 does cause an increased risk of developing MS. No results indicate that heterozygosity for Apo epsilon4 causes a greater risk of developing MS. No association between the Apo epsilon4 allele and MS subgroups, age of onset, and gender has been found. The association between Apo epsilon4 and relapse rate is contradictory. Most results confirm the hypothesis about an association between the Apo epsilon4 allele and increased disease progression. Two longitudinal studies found an association between Apo epsilon4 and increased disease progression. Half of the cross-sectional studies found the same association. Four of seven published studies examining the association between Apo epsilon4 and increased disease progression using magnetic resonance imaging (MRI) found a significant association. Apo epsilon4 appears to be a predisposing factor to a faster disease progression in MS.

Classification of the long-QT syndrome based on discriminant analysis of T-wave morphology

The long QT syndrome (LQTS) is a genetic disorder, typically characterized by a prolonged QT interval in the ECG due to abnormal cardiac repolarization. LQTS may lead to syncopal episodes and sudden cardiac death. Various parameters based on T-wave morphology, as well as the QT interval itself have been shown to be useful discriminators, but no single ECG parameter has been sufficient to solve the diagnostic problem. In this study we present a method for discrimination among persons with a normal genotype and those with mutations in the KCNQ1 (KvLQT1 or LQT1) and KCNH2 (HERG or LQT2) genes on the basis of parameters describing T-wave morphology in terms of duration, asymmetry, flatness and amplitude. Discriminant analyses based on 4 or 5 parameters both resulted in perfect discrimination in a learning set of 36 subjects. In both cases cross-validation of the resulting classifiers showed no misclassifications either.

High-efficiency multiplex capillary electrophoresis single strand conformation polymorphism (multi-CE-SSCP) mutation screening of SCN5A: a rapid genetic approach to cardiac arrhythmia

Mutations in the SCN5A gene coding for the alpha-subunit of the cardiac Na(+) ion channel cause long QT syndrome, Brugada syndrome, idiopathic ventricular fibrillation, sick sinus node syndrome, progressive conduction disease, dilated cardiomyopathy and atrial standstill. These diseases exhibit variable expressivity, and identification of gene carriers is clinically important, particularly in sudden infant and adult death syndromes. The SCN5A gene comprises 28 exons distributed over 100 kbp of genomic sequence at chromosome 3p21. Disease-causing mutations are private and scattered over the DNA sequence, making it difficult to screen for specific mutations. We developed a multiplex capillary-electrophoresis single-strand conformation polymorphism (Multi-CE-SSCP) mutation screening protocol on the ABI 3100 platform and applied it to 10 previously slab-gel SSCP identified mutations and SNPs and used it to identify one novel deletion. The method is highly efficient, with a turnover of 23 patients per 24 h and a false positive rate of 0.5% of the analyzed amplicons. Each variant has a particular elution pattern, and all 20 carriers of the H558R polymorphism out of 57 persons were correctly identified. We suggest that the method could become part of routine work-up of patients with suspicious syncope and of members of families with sudden unexplained death.

Apo E in multiple sclerosis and optic neuritis: the apo E-epsilon4 allele is associated with progression of multiple sclerosis

OBJECTIVE

To investigate the association between apolipoprotein E (Apo E) genotype in multiple sclerosis (MS) and acute monosymptomatic optic neuritis (ON) in a genetically homogeneous population with a high frequency of the Apo epsilon4 allele.

BACKGROUND

The association between heterozygosity of Apo epsilon4 and the development of MS is thoroughly investigated, while the association between homozygosity of Apo epsilon4 and the development of MS is insufficiently studied. The association between Apo E genotype and disease progression remains controversial.

METHODS

475 patients were included, 385 with MS and 90 with ON, consecutively seen in the MS clinic in the County of Copenhagen. Clinical data were obtained from medical records and degree of disability was determined prospectively using the Kurtzke expanded disability status scale (EDSS). Blood samples were used for Apo E genotyping. Disease progression was evaluated by the progression index (PI = EDSS/disease duration). Apo E genotype distribution was compared with 361 healthy controls.

RESULTS

The Apo epsilon genotype distribution in the MS and ON groups was similar to the controls. The rate of disease progression in the group of MS patients with a disease duration of 10 years or less was significantly faster in the Apo epsilon4 positive group (heterozygosity and homozygosity for Apo epsilon4) (PI = 1.41) compared to the Apo epsilon4 negative group (PI =0.92) (P =0.009). Observing the MS subgroups, we found that the group of patients with RRMS had a faster rate of disease progression in the Apo epsilon4 positive group (PI =1.12) compared to the Apo epsilon4 negative group (P =0.77) (P =0.024).

CONCLUSIONS

Apo E genotypes do not influence the development of MS and ON. The Apo epsilon4 allele seems to predispose carriers with MS to a faster progression of disease.

Inhibin A is a maternal serum marker for Down's syndrome early in the first trimester

Inhibin A is a maternal serum marker for fetal Down's syndrome (DS) in the second trimester. We examined whether inhibin A could be used early in the first trimester. Maternal serum concentrations of inhibin A were determined in 81 controls and 27 cases of fetal trisomy 21 in gestational week 5-11. The log MoM (Multiple of the Median of normal pregnancies) inhibin A concentration in DS pregnancies increased with gestational age (p = 0.001) from a mean log MoM (standard deviation) of -0.1754 (0.3712) (n = 11) in week 7-8 to a mean log MoM (standard deviation) of 0.1842 (0.2145) (n = 12) in week 9-11. This corresponded to an increase in inhibin median MoM from 0.67 to 1.53. When inhibin A was used together with pregnancy-associated plasma protein-A, free beta-human chorionic gonadotrophin and nuchal translucency as DS markers, the estimated detection rates were 81.4 and 82.6% in weeks 7-8 and 9-11, respectively, for false-positive rates of 0.9 and 1.0%. The performance of the latter combination early in the first trimester is nearly as good as that of integrated first- and second-trimester screening, with the further advantage that the risk can be reported to the pregnant woman in first trimester.

Improved first-trimester Down syndrome screening performance by lowering the false-positive rate: a prospective study of 9941 low-risk women

OBJECTIVE

To determine the performance of screening for Down syndrome (DS) and other major chromosomal abnormalities using nuchal translucency (NT), free beta-human chorionic gonadotropin (beta-hCG) and pregnancy-associated plasma protein-A (PAPP-A) in a prospective study of a non-selected population.

METHODS

Of 9941 women with an early ultrasound examination, NT was measured in 8622 singleton pregnancies with a gestational age between 10 + 3 and 13 + 6 weeks. beta-hCG and PAPP-A were analyzed in 6441 cases. Detection rates (DR) and false-positive rates (FPR) for the NT screening, the double test (beta-hCG and PAPP-A) and the combined test (NT and the double test) were calculated using a 1 : 250 cut-off.

RESULTS

NT could be measured in 97.5% of cases. The DR for DS with NT screening alone was 75% with a FPR of only 1.8%. The double test detected 73% and the combined test 91%, for FPRs of 8.8% and 2.1%, respectively. We detected 80% of fetuses with other major chromosomal abnormalities with a combination of NT screening and other ultrasound findings. Low beta-hCG and PAPP-A values (below 0.4 MoM) were observed in 0.5% of the women including all cases of triploidy and trisomy 18 and 13.

CONCLUSIONS

The performance of a screening strategy for DS using a combination of NT and the double test was superior to that using either NT or the double test alone due to a very low FPR and a higher DR.

Aberrant tetranectin expression in human breast carcinomas as a predictor of survival

AIMS

Tetranectin (TN), a plasminogen kringle 4 binding protein, is thought to play a prominent role in the regulation of proteolytic processes via binding to plasminogen. The aim of this study was to evaluate the expression of TN in human breast cancer and adjacent normal breast tissue and to determine the impact of this expression on survival.

METHODS

A retrospective analysis was performed on 189 patients with breast cancer, with a median follow up time of 10.6 years. The expression of TN was assessed in tumour tissue and adjacent normal breast tissue by immunohistochemistry, and the prognostic relevance of its expression in tumour cells was evaluated.

RESULTS

TN was highly expressed in connective tissue fibres surrounding normal breast epithelium, but not in normal epithelial cells. High expression of TN in tumour cells was found in 131 (69%) of the tumour samples. By western blot analysis, no significant difference in the amount and molecular weight of TN was seen between tumour tissue and normal tissue. Strong TN immunoreactivity in tumour tissue was predictive of poor disease free and tumour specific overall survival. By multivariate analysis, high TN expression in cancer cells was an independent prognostic factor for disease free and tumour specific overall survival.

CONCLUSIONS

Our results demonstrate differential TN expression in normal and malignant breast tissue and a prognostic impact of TN protein expression in breast carcinoma tissue. These data suggest a possible role of TN in invasiveness and the metastatic spread of human breast cancer.

Adipose tissue triglyceride turnover, de novo lipogenesis, and cell proliferation in humans measured with 2H2O

The turnover of adipose tissue components (lipids and cells) and the pathways of adipose lipid deposition have been difficult to measure in humans. We apply here a (2)H(2)O long-term labeling technique for concurrent measurement of adipose-triglyceride (TG) turnover, cell (DNA) proliferation, and de novo lipogenesis (DNL). Healthy subjects drank (2)H(2)O (70 ml/day) for 5-9 wk. Subcutaneous adipose tissue aspirates were taken (gluteal, thigh, and flank depots). Deuterium incorporation into TG glycerol (representing all-source TG synthesis), TG palmitate (representing DNL, by mass isotopomer distribution analysis), and DNA (representing cell proliferation) was measured by gas chromatography-mass spectrometry. Subjects tolerated the protocol well, and body (2)H(2)O enrichments were stable. Mean TG-glycerol fractional synthesis was 0.12 (i.e., 12%) with a range of 0.03-0.32 after 5 wk and 0.20 (range 0.08-0.49) after 9 wk (TG half-life 200-270 days). Label decay measurements 5-8 mo after discontinuing (2)H(2)O gave similar turnover estimates. Net lipolysis (TG turnover) was 50-60 g/day. DNL contribution to adipose-TG was 0.04 after 9 wk, representing approximately 20% of newly deposited TG. Cell proliferation was 0.10-0.17 after 9 wk (half-life 240-425 days). In summary, long-term (2)H(2)O administration to human subjects allows measurement of the dynamics of adipose tissue components. Turnover of all elements is slow, and DNL contributes approximately 20% of new TG.

CD4 T cell activation and disease activity at onset of multiple sclerosis

We studied CD4 T cell activation in patients with clinically isolated syndromes (CIS) suggesting an initial attack of multiple sclerosis. The percentage of blood CD26+ CD4 T cells was increased in these patients, and correlated with magnetic resonance imaging disease activity and clinical disease severity. In contrast, the percentage of CD25+ CD4 T cells in cerebrospinal fluid correlated negatively with the cerebrospinal fluid concentration of myelin basic protein and the presence of IgG oligoclonal bands. These results suggest that distinct systemic and intrathecal T cell activation states correlate with disease activity and risk of subsequently developing MS in CIS patients.

Biochemical markers for brain damage after carbon monoxide poisoning

BACKGROUND

Carbon monoxide poisoning is associated with high mortality and a substantial risk for brain damage in survivors. Evidence for acute brain dysfunction may be obtained by measuring concentrations of suitable biochemical markers. We hypothesized that increased serum concentrations of Neuron-specific enolase (NSE) and S-100beta protein could be detected after carbon monoxide poisoning and that the concentration would correlate with the severity of intoxication.

METHODS

Prospective non-interventional study in the university hospital. We included 20 patients admitted for hyperbaric treatment due to carbon monoxide poisoning. Serum levels of NSE and S-100beta protein were measured in all patients on admission and after 12, 24, 36 and 48 h. As a control group, we included 20 patients who underwent elective hyperbaric treatment.

RESULTS

Serum concentrations of NSE and S-100beta protein were not significantly different from the controls, with median values at admission being 10.6 vs. 9.7 microg l(-1) and 0.15 vs. 0.13 microg l(-1), respectively (P = 0.82 and P = 0.38). The concentrations did not change significantly during the sampling period. We were unable to show any significant relation to level of consciousness.

CONCLUSION

Blood concentrations of NSE and S-100beta protein were not significantly increased after carbon monoxide poisoning and do not seem to be related to a history of unconsciousness.

Human Plasma-Derived Mannose-Binding Lectin: A Phase I Safety and Pharmacokinetic Study

Mannose-binding lectin (MBL) is an important component of innate immunity that can bind to certain sugar residues on the surface of many types of pathogenic micro-organisms. On binding, MBL generates opsonic activity mainly through activation of the complement system. Genetically determined MBL deficiency is very common and can be associated with increased susceptibility to a variety of infections, especially in children and immunosuppressed individuals. The potential benefits of MBL reconstitution therapy therefore need to be evaluated. We have carried out a phase I safety and pharmacokinetic study on 20 MBL-deficient healthy adult volunteers. The MBL was prepared from plasma of nonremunerated, voluntary Danish donors tested and found negative for hepatitis B surface antigen, antibodies to human immunodeficiency virus (HIV) and hepatitis C virus. Each volunteer received a total of 18 mg of MBL in three 6 mg doses given intravenously, once weekly over a period of 3 weeks. The volunteers were closely monitored at the University Hospital in Reykjavik for 8 h after each infusion and daily thereafter for 5 days after each infusion. No adverse clinical or laboratory changes were observed in any of the 20 participants, and frequent measurements did not reveal any signs of infusion-associated complement activation. No antibodies to MBL, HIV or hepatitis viruses were observed 24 weeks after the last infusion. Serum MBL levels increased up to normal levels (1200-4500 ng/ml) immediately after each infusion, but the half-life of the infused MBL was highly variable, ranging from 18 to 115 h (mean 69.6). It is concluded that infusion of purified MBL as prepared by Statens Serum Institut (SSI) is safe. However, adults have to be given at least 6 mg twice or thrice weekly for maintaining protective MBL levels assumed to be about 1000 ng/ml.

Screening for Down's syndrome in early and late first and second trimester using six maternal serum markers

The efficiency of six maternal serum markers for Down's syndrome (DS), alpha fetoprotein (AFP), human chorionic gonadotropin (hCG), free beta-hCG, pregnancy-associated plasma protein-A (PAPP-A), the proform of eosinophil major basic protein (ProMBP), pregnancy-specific-beta-1-glycoprotein (SP(1)), and combinations thereof, was examined. Discriminant analysis in 156 DS pregnancies and 546 controls defined three effective combinations of serum marker logMoMs (multiples of the median in control samples) in three gestational age windows, i.e. Index I (weeks 7-9) = 0.52 logMoM ProMBP + 0.28 logMoM PAPP-A - logMoM SP(1); Index II (weeks 10-12) = 1.94 logMoM free beta-hCG - logMoM SP(1), and Index III (weeks 15-19) = 0.78 logMoM free beta-hCG + 1.12 logMoM ProMBP - logMoM AFP. The estimated detection rates of indices and age for a false-positive rate (FPR) of 5% were 73% for Index I, 69% for Index II, and 60% for Index III. Including the ultrasound marker nuchal translucency, using a DS at term risk of 1 : 400 as cut-off, the detection rates of the indices increased to 86, 83, and 82% for FPRs of 4.3, 4.1, and 5.8%, respectively. The indices are promising markers for screening for DS.

Long QT syndrome patients may faint due to neurocardiogenic syncope

AIMS

Syncope in long QT syndrome (LQTS) is expected to be due to Torsades de Pointes ventricular tachycardia (TdP). Often these patients faint in situations with emotional stress. The aim of the present study was to evaluate whether neurocardiogenic syncope occurs in LQTS.

METHODS AND RESULTS

Ten untreated consecutive LQTS patients (age 11-72 years, median 37.5 years, five males and five females from five different families (one KvLQT1 mutation, two HERG mutations in three families and one without established genetic background)) were examined by a head-up tilt-table test (HUT). If syncope did not occur within 25 min, the patient received 0.25 mg nitroglycerine sublingually and the HUT was continued for 20 min. Nine out of 10 patients had a positive HUT. The syncope resulted from a combined vasodepressor and bradycardiac response. There were no cases of TdP. No syncope occurred in a 42-year-old asymptomatic male LQTS patient with a borderline prolonged QTc of 0.45 s and a HERG mutation. In 11 of 21 patients referred for syncope without LQTS a positive HUT was found (P < 0.10).

CONCLUSION

Syncope in LQTS can be of neurocardiogenic origin and is not necessarily due to TdP. The reason for neurocardiogenic syncope in LQTS is unknown, but involvement of the autonomic nervous system outside the heart is possible.

Reactive arthritis and serum levels of mannose binding lectin -- lack of association

The purpose was to evaluate the possible association of serum mannose binding lectin (s-MBL) levels on type of triggering microbe, duration of diarrhoea, incidence and course of reactive arthritis (ReA) caused by Salmonella, Yersinia and Campylobacter. Sixty patients with ReA of 1-228 months duration, 173 patients with ReA or uncomplicated enterocolitis caused by Campylobacter, 226 sera from patients with elevated antibody levels against Salmonella, Yersinia or Campylobacter, and 114 blood donors were tested for s-MBL using ELISA technique, both direct mannan binding assay and sandwich ELISA. s-MBL was compared with C-reactive protein (CRP) levels and with the ability of activating complement C4. Among the 114 donors 9% had s-MBL <50 microg/l, 16% had from 50-500 microg/l and 75% had >500 microg/l. The distribution of s-MBL levels in the three-patient groups did not differ significantly from the controls. There were no indications that low s-MBL was associated with prolonged duration of arthritis, diarrhoea or individual bacterial infections. The two MBL assays were comparable with respect to serum concentrations, indicating that the actual circulating MBL was also functionally active. s-MBL exhibited acute phase reactant behaviour and correlated to CRP level, but only in patients with s-MBL concentrations exceeding 1000 microg/l. MBL in 10 randomly selected ReA sera were tested for the ability to activate complement C4. The results did not differ from those of donor controls. This study demonstrates that the distributions of s-MBL levels in serum among patients with ReA are not different from donor controls. The course, outcome or triggering bacteria are not associated with a particular level of s-MBL.

Measurement in vivo of proliferation rates of slow turnover cells by 2H2O labeling of the deoxyribose moiety of DNA

We describe here a method for measuring DNA replication and, thus, cell proliferation in slow turnover cells that is suitable for use in humans. The technique is based on the incorporation of (2)H(2)O into the deoxyribose (dR) moiety of purine deoxyribonucleotides in dividing cells. For initial validation, rodents were administered 4% (2)H(2)O in drinking water. The proliferation rate of mammary epithelial cells in mice was 2.9% per day and increased 5-fold during pregnancy. Administration of estradiol pellets (0-200 microg) to ovariectomized rats increased mammary epithelial cell proliferation, according to a dose-response relationship up to the 100 microg dose. Similarly, proliferation of colon epithelial cells was stimulated in a dose-response manner by dietary cholic acid in rats. Bromodeoxyuridine labeling correlated with the (2)H(2)O results. Proliferation of slow turnover cells was then measured. Vascular smooth muscle cells isolated from mouse aorta divided with a half-life in the range of 270-400 days and die-away values after (2)H(2)O wash-out confirmed these slow turnover rates. The proliferation rate of an adipocyte-enriched fraction from mouse adipose tissue depots was 1-1.5% new cells per day, whereas obese ad libitum-fed obob mice exhibited markedly higher fractional and absolute proliferation rates. In humans, stable long-term (2)H(2)O enrichments in body water were achieved by daily (2)H(2)O intake, without toxicities. Labeled dR from fully turned-over blood cells (monocytes or granulocytes) exhibited a consistent amplification factor relative to body (2)H(2)O enrichment ( approximately 3.5-fold). The fraction of newly divided naive-phenotype T cells after 9 weeks of labeling with (2)H(2)O was 0.056 (CD4(+)) and 0.043 (CD8(+)) (replacement rate <0.1% per day). In summary, (2)H(2)O labeling of dR in DNA allows safe, convenient, reproducible, and inexpensive measurement of cell proliferation in humans and experimental animals and is well suited for slow turnover cells.

Presence of clone-specific markers at birth in children with acute lymphoblastic leukaemia

Recent studies have suggested that development of childhood acute lymphoblastic leukaemia may often be initiated in utero. To provide further evidence of an prenatal origin of childhood leukaemia, we conducted a molecular biological investigation of nine children with B-precursor acute lymphoblastic leukaemia carrying the chromosomal translocation t(12;21), the most common subtype of all childhood acute lymphoblastic leukaemia. Specifically, for each child we identified the non-constitutive chromosomal sequences made up by the t(12;21) fusion gene. From these, leukaemia clone-specific DNA primers were constructed and applied in nested polymerase chain reaction analyses of DNA extracted from the patients' Guthrie cards obtained at birth. Leukaemia clone-specific fusion gene regions were demonstrated in Guthrie card DNA of three patients, age 2 years 11 months, 3 years 4 months, and 5 years 8 months at leukaemia diagnosis. Our findings are consistent with previous observations, and thus provide further evidence that the development of t(12;21) B-precursor acute lymphoblastic leukaemia may be initiated in utero. Review of the current literature moreover indicates that age at leukaemia may be inversely correlated with the burden of cells with leukaemia clonal markers, i.e. leukaemia predisposed cells at birth, and that certain types of childhood acute lymphoblastic leukaemia develop as a multiple step process involving both pre- and postnatal genetic events.