Family study of epilepsy in first degree relatives: data from the Italian Episcreen Study

OBJECTIVE

To evaluate the family history of epilepsy in first degree relatives of probands with epilepsy.

METHODS

A sample of 10787 patients with epilepsy with complete information about first degree relatives (parents, siblings and offspring) was selected from the database of the Episcreen Project, the largest Italian observational study on epilepsy. Family history was assessed by: (1) prevalence estimates of epilepsy among proband's relatives, (2) modified cumulative risks (MCR), adjusted using proband's age as censoring time in life tables, (3) standardised morbidity ratios (SMR), using a sub-group of symptomatic epilepsies as control group.

RESULTS

Patients (9.1%) had a family history of epilepsy. The overall prevalence of epilepsy among first degree relatives was 2.6%. Idiopathic generalised epilepsies had the highest prevalence (5.3%). Cryptogenetic epilepsies had a lower prevalence (2.1%) than idiopathic epilepsies, but higher then symptomatic epilepsies (1.5%), both in generalised and focal forms (3.8% vs. 2.0% and 1.8% vs. 1.3%). A similar tendency was detected using MCR and SMR, with the higher values of risks/ratios for idiopathic and generalised epilepsies. Probands with idiopathic generalised epilepsies were highly concordant with respect to their relatives' type of epilepsy. Considering other strata factors, risks were higher in proband's epilepsies with an onset less then 14 years of age, while sex played no definite role in differentiating the family history.

CONCLUSIONS

The Episcreen model permits a variety of stratification factors to measure family risk, including age at onset, epilepsy localisation and aetiology with a large sample of more than 10,000 probands and 1065/40,544 relatives affected and classified.

The Italian multicentre study on noninvasive ventilation in chronic obstructive pulmonary disease patients

Chronic obstructive pulmonary disease (COPD) patients with chronic ventilatory failure (CVF) are more likely to develop exacerbations, which are an important determinant of health-related quality of life (HRQL). Long-term noninvasive positive-pressure ventilation (NPPV) has been proposed in addition to long-term oxygen therapy (LTOT) to treat CVF but little information is available on its effects on HRQL and resource consumption. Therefore, the current authors undertook a 2-yr multicentric, prospective, randomised, controlled trial to assess the effect of NPPV+ LTOT on: 1) severity of hypercapnia; 2) use of healthcare resources, and 3) HRQL, in comparison with LTOT alone. One hundred and twenty-two stable hypercapnic COPD patients on LTOT for > or = 6 months were consecutively enrolled. After inclusion and 1-month run-in, 90 patients were randomly assigned to NPPV+LTOT (n=43) or to LTOT alone (n=47). Arterial blood gases, hospital and intensive care unit (ICU) admissions, total hospital and ICU length of stay and HRQL were primary outcome measures; survival and drop-out rates, symptoms (dyspnoea and sleep quality) and exercise tolerance were secondary outcome measures. Follow-up was performed at 3-month intervals up to 2 yrs. Lung function, inspiratory muscle function, exercise tolerance and sleep quality score did not change over time in either group. By contrast the carbon dioxide tension in arterial blood on usual oxygen, resting dyspnoea and HRQL, as assessed by the Maugeri Foundation Respiratory Failure Questionnaire, changed differently over time in the two groups in favour of NPPV+LTOT. Hospital admissions were not different between groups during the follow-up. Nevertheless, overall hospital admissions showed a different trend to change in the NPPV+LTOT (decreasing by 45%) as compared with the LTOT group (increasing by 27%) when comparing the follow-up with the follow-back periods. ICU stay decreased over time by 75% and 20% in the NPPV+LTOT and LTOT groups, respectively. Survival was similar. Compared with long-term oxygen therapy alone, the addition of noninvasive positive-pressure ventilation to long-term oxygen therapy in stable chronic obstructive pulmonary disease patients with chronic ventilatory failure: 1) slightly decreased the trend to carbon dioxide retention in patients receiving oxygen at home and 2) improved dyspnoea and health-related quality of life. The results of this study show some significant benefits with the use of nocturnal, home noninvasive positive-pressure ventilation in patients with chronic ventilatory failure due to advanced chronic obstructive pulmonary disease patients. Further work is required to evaluate the effect of noninvasive positive-pressure ventilation on reducing the frequency and severity of chronic obstructive pulmonary disease exacerbation.

Aims and methods. LUTS suggestive of BPH

OBJECTIVE

Few epidemiological studies are available on Italian patients with lower urinary tract symptoms and their QoL. QUIBUS (QUality of life Investigated in BPH patients with Urinary Symptoms) is an observational longitudinal study aimed at evaluating symptoms and QoL in a large sample of Italian patients and investigating their correlation with demographic, social and clinical characteristics of BPH.

PATIENTS AND METHODS

Patients with lower urinary tract symptoms and prostate enlargement suggestive of BPH (both old and new diagnosis) were enrolled between November 1998 and May 1999 in 31 Italian centers of urology. This longitudinal investigation consists of an enrollment visit, in which demographic, social and clinical aspects are recorded as baseline data, and a follow-up visit after 1 year of treatment freely assigned by the investigators. Symptoms and QoL are assessed by means of IPSS, ICS-BPH (at both visits) and SF-36 (only at the follow-up visit) questionnaires.

RESULTS

1,033 patients were enrolled. The follow-up visit is still under evaluation. In this series of papers the baseline results are presented and discussed in terms of (i) medical management, (ii) life-style, (iii) symptoms, bothersomeness and QoL, (iv) sexual function of a large and representative sample of Italian patients and (v) uroflowmetry.

Incidence of erectile dysfunction in Italian men with diabetes

PURPOSE

We determined the incidence of erectile dysfunction in Italian men with diabetes.

MATERIALS AND METHODS

We estimated the incidence of erectile dysfunction, defined as failure to achieve and maintain erection sufficient for satisfactory sexual performance, after 2.8 years of followup in 1,010 men enrolled for a prevalence study of erectile dysfunction in diabetes.

RESULTS

Of the 1,010 men 192 (19%) complained of erectile dysfunction. The crude incidence rate of erectile dysfunction was 68 cases per 1,000 person-years (95% confidence interval 59 to 77). The incidence of erectile dysfunction increased with increasing age (10-fold higher for ages 70 to 79 than for 19 to 29 years), duration of diabetes (1.6-fold higher a history of 11 years or greater than for less than 5) and deteriorating metabolic control (1.7-fold higher for hemoglobin A1c greater than 9% than less than 7.5%). Moreover, it was higher in type 2 than in type 1 diabetes (74 versus 45 cases per 1,000 person-years). The relative risk was 1.75, 2.02, 1.97, 1.16, 1.86, 3.79 and 1.52 for associated obliterative arterial disease of the lower legs, ischemic heart disease, renal disease, autonomic neuropathy, sensitive and motor neuropathy, diabetic foot and retinal disease, respectively. Of the characteristics at study enrollment patient age, duration of diabetes, renal disease and hypertension were multivariate predictors of the erectile dysfunction 2.8 years later.

CONCLUSIONS

The incidence of erectile dysfunction in Italian men with diabetes at a mean followup of 2.8 years was 68 cases per 1,000 person-years, more than 2-fold that in the Massachusetts Male Aging Study of the general population. The knowledge of this incidence should promote specific preventive and therapeutic interventions for erectile dysfunction in men with diabetes.

Effects of simulated microgravity on metabolic activities related to DNA damage and repair in lymphoblastoid cells

We adopted a simple experimental framework to follow the dependence of structural aberrations and the modifications in selected metabolic processes correlated with the exposure of cells to microgravity. Alterations to the cellular metabolism induced by exposure to microgravity are evidentiated in the modification of PARP activity (strongly dependent to the presence of DNA damages and to the altered gene expression), in the modification of the repair ability and in the cell's energy homeostasis (NAD and ATP). Cells are exposed continuously to microgravity in a Random Positioning Machine (RPM) in complete medium for 48 hours. At the end of this period a part of these cells are immediately analysed for the parameters reported above and the remaining were furtherly incubated in standard laboratory conditions to document eventual defects during the phases of the recovery process. A part of cells, just after exposure to microgravity, were also subjected to treatment with a strong damaging agent, KBrO3, and these cells were subsequently analyzed. This final treatment was meant to amplify the eventual deficiencies experienced by microgravity-exposed cells in the DNA repair process also in dependence with the alterated metabolic conditions resulting after the exposure to microgravity.

The predictive value of attributes of pain to classify rheumatoid arthritis

Out of 2300 patients with rheumatic diseases 1627 were analysed to develop a classification of rheumatoid arthritis based on clinical attributes of pain. Of these, 641 patients had the disease and 986 were controls with other rheumatic conditions. For traditional format classification, six of eight variables were selected: pain at a fixed joint; symmetrical pain; continuous pain; pain mainly present at night or in the morning; pain following joint pressure; and pain decreased by load/movement. The occurrence of four or more of these features was associated with a 72.1% sensitivity and a 79.1% specificity. A classification tree constructed on four features that showed the greatest diagnostic power (symmetrical pain, pain mainly present at night or in the morning, pain at joint pressure, continuous pain), was associated with a 75.8% sensitivity and a 77.0% specificity.

Reliability of a questionnaire for evaluating the understanding of asthma

The present study was designed to evaluate the repeatability of a questionnaire developed to assess the understanding that asthma patients have of their disease and, on the basis of its variability, estimate the sample size necessary for determining the efficacy of a future structured program on asthma knowledge. The repeatability of the Asthma Questionnaire (AQ) was evaluated by asking 89 patients to complete it twice within a period of 7-10 days without the subject being exposed to any programme on asthma knowledge between the two administrations. The AQ was demonstrated to have good content and face validity. Results showed that neither age nor sex had a significant influence on total scores, and that the degree of reliability was adequate (R = 0.769). The mean percentage of correct answers was observed to be approximately 70% in both sessions, suggesting a consistent area for possible improvement which could be targeted by means of an appropriately structured programme on asthma knowledge. For comparative purposes before and after the programme, or for measuring its efficacy, the AQ should be recommended. In conclusion the Asthma Questionnaire could provide a useful tool for the general practitioner, chest physician and other health professionals, to assess what the patient really does understand or does not, concerning asthma management, and hence be the starting point for a well-tailored educational intervention.

Partial characterization of SUVi, a new mammalian gene induced by UV-C and expressed during the S phase of the cell cycle

By using a lacZ-based gene-trap approach, we identified a mammalian gene induced by UV-C in a Chinese hamster ovary cell clone (Menichini P et al. [1997]: Nucleic Acids Res 25:4803-4807). The activity of the encoded protein fused to a bacterial beta-galactosidase was followed through the hydrolysis of different beta-galactosidase substrates. In this study we describe how the expression of this gene is modulated during the cell cycle and in response to UV-irradiation. We show that the beta-galactosidase activity was virtually undetectable in quiescent cells (G[0]), started to increase when cells progressed in G(1), and reached a maximum in mid-S phase, indicating a possible role of the endogenous protein during DNA synthesis. Following UV-irradiation, besides a delay of the progression through the S phase, a twofold increase of the reporter protein activity in all phases of the cell cycle was observed. The partial sequence analysis showed that this gene, here named SUVi (for S phase UV-inducible), contains a domain that is highly conserved among different helicases. Together, these data suggest that the SUVi gene could be involved in DNA synthesis, a process that takes place both in the S phase and in the processing of UV-induced damage.

The yeast p53 functional assay: a new tool for molecular epidemiology. Hopes and facts

The assumption of molecular epidemiology that carcinogens leave fingerprints has suggested that analysis of the frequency, type, and site of mutations in genes frequently altered in carcinogenesis may provide clues to the identification of the factors contributing to carcinogenesis. In this mini-review, we revise the development, and validation of the yeast-based p53 functional assay as a new tool for molecular epidemiology. We show that this assay has some very interesting virtues but also has some drawbacks. The yeast functional assay can be used to determine highly specific mutation fingerprints in the human p53 cDNA sequence. Discrimination is possible when comparing mutation spectra induced by sufficiently different mutagens. However, we also reported that the same carcinogen may induce distinguishable mutation spectra due to known influencing factors.

Chromosomal aberrations evaluated by CGH, FISH and GTG-banding in a case of AIDS-related Burkitt's lymphoma

BACKGROUND AND OBJECTIVE

We have previously reported on a complex chromosome rearrangement [der(17)] in a B-cell line, BRG A, established from an AIDS patient with Burkitt's lymphoma (BL). The aim of the present study was the definition of der(17) composition and the identification of complete or partial chromosome gains and losses in two cell clones (BRG A and BRG M) derived from this patient.

DESIGN AND METHODS

We applied comparative genome hybridization (CGH) to detect the DNA misrepresentations in the genome of the two cell clones. Findings from CGH and banding analysis could then direct the choice of probes for chromosome painting experiments to elucidate der(17) composition.

RESULTS

CGH analysis identified gains of chromosomes 1q, 7q, 12q, 13q, 15q, 17p, 20p,q and losses of chromosomes 3p and 5q in BRG A and gain of chromosome 1q and loss in chromosome 6q in BRG M. Some of the detected alterations had already been described in lymphomas, while others appeared to be new. The combination of these techniques allowed a precise definition of der(17), composed by translocated regions from chromosomes 12 and 15.

INTERPRETATION AND CONCLUSIONS

We demonstrated CGH to be a powerful tool in the identification of recurrent chromosome aberrations in an AIDS-related BL and in ascertaining the origin of marker chromosomes. We were also able to identify a different pattern of aberrations and assess an independent sequence of events leading to the 1p gain in the two subclones.

p53 mutations experimentally induced by 8-methoxypsoralen plus UVA (PUVA) differ from those found in human skin cancers in PUVA-treated patients

8-Methoxypsoralen (8-MOP) plus UVA irradiation (PUVA therapy) has been used for the treatment of psoriasis. PUVA therapy has been associated with an increased risk of developing skin squamous cell carcinoma (SCC). In order to determine the PUVA-induced p53 mutation spectrum, a yeast expression vector harbouring a human wild-type p53 cDNA was incubated with 8-MOP, and UVA irradiated in vitro. PUVA-damaged and undamaged DNA was transfected into a yeast strain containing the ADE2 gene regulated by a p53-responsive promoter. An 8-MOP concentration-dependent decrease in survival and increase in mutant frequency were observed. At a fixed 8-MOP concentration, survival decreased and mutant frequency increased as UVA irradiation increased. Eleven mutant clones contained 11 mutations: 10 were single base pair substitutions, the remaining one being a complex mutation. All eight T:A-targeted mutations were at 5'-TpA sites, hallmark mutations of PUVA mutagenesis. Through a rigorous statistical test, the PUVA-induced p53 mutation spectrum appears to differ significantly (P < 0.0002) from that observed in SCC in PUVA-treated patients. The present work demonstrates that a specific PUVA-induced mutational fingerprint could be obtained and recognized on human p53 cDNA. This result may suggest that PUVA therapy can be a risk factor for the development of SCC in psoriasis patients through a mechanism not involving the induction of p53 mutations.

Cost-of-illness of epilepsy in Italy. Data from a multicentre observational study (Episcreen)

OBJECTIVE

To investigate the impact of epilepsy in Italy on healthcare resources, producing an average cost per patient per year of follow-up.

DESIGN AND SETTING

The Episcreen Project is a multicentre longitudinal Italian observational study; its methodology, organisational network and case report form have been reported in detail elsewhere. Using a subset of patients with epilepsy from this project, we conducted a retrospective cost-of-illness analysis based on clinical records. The analysis was performed from the societal (community) perspective, including both direct and indirect costs. Hospital admissions, day-hospital visits, specialist visits, instrumental examinations, drugs and productivity losses because of visits and hospitalisation were analysed. Each cost variable was valued in 1996 Italian liras (L) using published national tariffs (except for drugs for which published prices were used). A sensitivity analysis was conducted on indirect costs to test the robustness of the assumption that 1 working day lost for each day hospital visit would produce a change of 0.3% in the weight of indirect costs.

PATIENTS AND PARTICIPANTS

Patients analysed in this study were registered in the Episcreen database as at 21 November 1996. They were diagnosed with epilepsy at the last visit, had at least 1 follow-up visit (i.e. at least 1 visit after the enrolment visit), and had at least 12 months of follow-up.

RESULTS

The average cost per patient per year was L2,726,116 ($US1767). The average cost per patient was higher for children than for adults [L3,629,997 ($US2353) and L2,362,134 ($US1531), respectively), and for newly diagnosed patients for whom the first diagnosis of epilepsy was addressed at the first Episcreen visit [adults: old referrals L1,304,353 ($US845), new referrals L6,901,374 ($US4473); children: old referrals L2,810,504 ($US1822), new referrals L7,814,400 ($US5065)]. Direct costs represented 87.6% of total costs. The major cost driver was hospitalisation (63.7%), followed by drugs (10.5%), day-hospital visits (4.1%), out-patient visits (3.85%), other tests (3.1%) and electroencephalographs (2.3%). Indirect costs (lost productivity) represented 12.4% of total costs. Sensitivity analysis showed that the results are sensitive to the value attributed to lost productivity.

CONCLUSIONS

The cost of managing a patient with epilepsy in Italy is influenced by age, syndrome and modality of referral to the centre for epilepsy.

5-methylcytosine at HpaII sites in p53 is not hypermutable after UVC irradiation

Using a yeast based p53 functional assay we previously demonstrated that the UVC-induced p53 mutation spectrum appears to be indistinguishable from the one observed in Non Melanoma Skin Cancer (NMSC). However, position 742 (codon 248, CpG site) represented the major hot spot in NMSC but was not found mutated in the yeast system. In order to determine whether UVC-induced mutagenic events may be facilitated at methylated cytosine (5mC), a yeast expression vector harbouring a human wild-type p53 cDNA (pLS76) was methylated in vitro by HpaII methylase. Methylation induced 98% protection to HpaII endonuclease. Unmethylated and methylated pLS76 vectors were then UVC irradiated (lambda(max): 254 nm) and transfected into a yeast strain containing the ADE2 gene regulated by a p53-responsive promoter. The results revealed that: (i) 5mC at HpaII sites did not cause any difference in the UVC-induced survival and/or mutagenicity; (ii) none of the 20 mutants derived from methylated pLS76 showed p53 mutations targeted at HpaII sites; (iii) the UVC-induced p53 mutation spectra derived from methylated and unmethylated pLS76 were indistinguishable not only when classes of mutations and hot spots were concerned, but also when compared through a rigorous statistical test to estimate their relatedness (P = 0.85); (iv) the presence of 5mC did not increase the formation of photo-lesions at codon 248, as determined by using a stop polymerase assay. Although based on a limited number of mutants, these results suggest that the mere presence of 5mC at position 742 does not cause a dramatic increase of its mutability after UVC irradiation. We propose that position 742 is a hot spot in NMSC either because of mutagenic events at 5mC caused by other UV components of solarlight and/or because not all the NMSC are directly correlated with UV mutagenesis but may have a "spontaneous" origin.

Anthropometry fails in classifying bone mineral status in postmenopausal women

This study tested two hypotheses: (1) that simple anthropometric parameters can be used to identify patients at risk of decreased bone mineral content and (2) that an inverse relationship exists between waist:hip ratio (WHR) and bone mineral density (BMD). Bone mineral content (BMC) and BMD were evaluated by dual-energy X-ray absorptiometry in 1873 free-living women. Of these, 1819 (97%) were post-menopausal. One thousand and thirteen women (54%) had normal BMD, 705 (38%) osteopenia and 155 (8%) osteoporosis. Body weight (Wt), body mass index and arm muscle and fat areas were significantly lower in osteoporotics than osteopenics (p < 0.0001) and in these latter than controls (p < 0.0001). However, values of WHR were similar in all groups (p = ns). Body weight was the anthropometric parameter better correlated with BMC (rho = 0.650, p < 0.0001) and only Wt and age were identified as significant predictors of bone mineral status (normal-BMD/osteopenic/osteoporotic) at polytomous logistic regression (p = 0.0001 for each). However, Wt could not be employed as an indicator of bone mineral status at the individual level because of high variations in BMC for the same level of Wt. Under- (< 5th percentile) and normal-Wt (5th-95th percentile) women had the same frequency of osteopenia (39%) while it was lower in over-Wt (> 95th) women (13%). The frequency of osteoporosis was higher in under- than normal-Wt women (37 vs 7%) and none of the over-Wt women had osteoporosis. This study shows that: (1) simple anthropometric measurements cannot be used to select subjects at risk of decreased BMC and, (2) BMD does not vary with WHR.

N-(2-chloroethyl)-N-nitrosourea tethered to lexitropsin induces minor groove lesions at the p53 cDNA that are more cytotoxic than mutagenic

Many different N-chloroethyl-N-nitrosourea (CENU) derivatives have been synthesized in an attempt to minimize carcinogenic activity while favoring antineoplastic activity. CENU derivatives linked to the dipeptide lexitropsin (lex) showed significant changes in groove- and sequence-selective DNA alkylation inducing thermolabile N3-alkyladenines (N3-Alkyl-As) at lex equilibrium binding sites. CENU-lex sequence specificity for DNA alkylation was determined using 32P-end-labeled restriction fragments of the p53 cDNA. The adducted sites were converted into single-strand breaks by sequential heating at neutral pH and exposure to piperidine. To establish the mutagenic and lethal properties of CENU-lex-specific lesions, a yeast expression vector harboring a human wild-type p53 cDNA was treated in vitro with CENU-lex and transfected into a yeast strain containing the ADE2 gene regulated by a p53-responsive promoter. p53 mutants were isolated from independent ade- transformants. The results revealed that: (a) CENU-lex preferentially induces N3-Alkyl-A at specific lex equilibrium binding sites, the formations of which are strongly inhibited by distamycin; (b) reactivity toward Gs is still present, albeit to a lesser extent when compared to N-(2-chloroethyl)-N-cyclohexyl-N-nitrosourea and to CENU; (c) 91% of the 49 CENU-lex p53 mutations (45 of 49) were bp substitutions, 29 of which were GC-->AT transitions, mainly at 5' purine G sites; (d) all AT-targeted mutations but one were AT-->TA transversions; (e) the distribution of the CENU-lex mutations along the p53 cDNA was not random, with position 273 (codon 91), where only GC-->AT transitions were observed, being a real (n = 3, P < 0.0002) CENU-lex mutation hot spot; and (f) a shift in DNA alkylation sites between lesion spectra induced by CENU-lex and N-(2-chloroethyl-N-cyclohexyl-N-nitrosourea was associated with an increased lethality and a decreased mutagenicity, whereas no dramatic change in mutational specificity was observed. Hence, it is tempting to conclude that, in this experimental system, N3-Alkyl-A is more lethal than mutagenic, whereas O6-alkylguanine is a common premutational lesion formed at non-lex binding sites. These results suggest that CENU derivatives with virtually absolute specificity for A residues would make targeting of lethal, nonmutagenic lesions at A+T-rich regions possible, and this may represent a new strategy for the development of new chemotherapeutic agents with a higher therapeutic index.

The monoethylglycinexylidide test for grading of liver cirrhosis

BACKGROUND

Monoethylglycinexylidide (MEGX) formation following lignocaine injection has recently been proposed as a simple dynamic liver function test based on a single measurement of its serum concentration.

AIM

To determine the optimal sampling time for MEGX determination.

METHODS

A modelling analysis of lignocaine and MEGX kinetics was performed in seven normals and in four patients with compensated liver cirrhosis; a similar study was performed in 74 cirrhotic patients, divided into two groups according to disease severity (Pugh score).

RESULTS

Only the MEGX fractional formation rate (kf) and formation delay (tau) were significantly altered in cirrhotic patients compared to normals: kf = 0.15 +/- 0.03 vs. 0.32 +/- 0.10 min-1 (mean +/- s.d.); tau = 7.7 +/- 2.0 vs. 3.9 +/- 2.9 min-1. A good correlation was found between kf and late (r = 0.82) but not early (r = 0.63) serum MEGX formation, suggesting that late measurements for the clinical MEGX test are preferred. In the second part of our investigation, by discriminant analysis of MEGX test data for 74 cirrhotic patients, the late MEGX concentrations gave the best discrimination between the two classes. In particular, the 60 min MEGX concentration showed the best diagnostic accuracy (81%), sensitivity (75%) and specificity (84%). The association of this with other MEGX parameters, either singly or derived from the whole curve measurements, did not improve the performance of the method.

CONCLUSION

The MEGX test, based on a single determination 60 min after lignocaine injection, may be regarded as a simple and sensitive quantitative liver function test.

A gene trap approach to isolate mammalian genes involved in the cellular response to genotoxic stress

Treatment of cells with DNA damaging agents leads to induction of a variety of genes involved in different cellular processes. We have applied a lacZ-based gene trap strategy to search for new mammalian genes induced by genotoxic stress. A population of 32 x 10(3) neo r clones stably transfected with a gene trap vector was obtained, stained with fluorescein di-beta-d-galactopyranoside and analyzed by flow activated cell sorting and replica plating. This strategy allowed isolation of 30 neo r 'putative inducible' cell lines expressing lacZ only after a DNA damaging treatment. For three clones the site of integration and the degree of inducibility after UV treatment were determined by Southern blot and beta-galactosidase measurement respectively. One cell line (clone VI) showed a single integration site and a reproducible 3-fold induction of beta-galactosidase activity following UV irradiation. Fused transcripts were isolated from induced cells and a portion of the trapped gene was amplified by rapid amplification of cDNA ends. Sequence analysis and comparison with available gene and protein databanks revealed that the gene was novel.

Kinetics of radiation- and cytochrome c-induced modifications in liposomes analysed by FT-Raman spectroscopy

Fourier transform Raman spectroscopy on artificial lipid membranes was used to study radiation-induced peroxidation processes as a function of time after radiation exposure. The time dependent intensity changes of the Raman lines of various C=C bondings were compared to results obtained by measuring conjugated dienes and by the thiobarbituric acid test for malondialdehydes. The results show that mainly the cis C=C bonds of the lipid chains are involved and, therefore, indicate that gamma-radiation induces conformational changes in the lipid chain while the mobility of the lipid chains is reduced. New Raman bands can be assigned to aldehyde products induced at the end of the peroxidation process. The immediate decrease of the =CH vibration lines was directly correlated with the formation of conjugated C=C double bonds suggesting that these vibration lines are in contrast to the C=C lines solely Raman active, when isolated C=C bonds are present. Cytochrome c (ox.) incorporated into the bilayer of the artificial membranes induced autooxidation processes not influenced by gamma-radiation. It was observed that cytochrome c (ox.)-induced changes of the relative intensity of the C=C bonds differ from those induced by gamma-radiation. These results of cytochrome c together with the inhibitory effects of the antioxidant alpha-tocopherol suggest that the radical species involved in the cytochrome c induced process might be different from the free radicals involved in the gamma-radiation-induced process.

Clinical pattern of pain in rheumatoid arthritis

OBJECTIVE

To evaluate whether rheumatoid arthritis (RA) is associated with a characteristic clinical pattern of pain which may be useful as a criterion to differentiate RA from other rheumatic diseases.

METHODS

2300 patients from the ReumaLink data bank project with definite rheumatic diseases were studied. Of these 907 patients (39.5%) fulfilled the ARA/ACR revised criteria for RA, while 1393 had rheumatic diseases other than RA. The following diagnostic attributes of pain were considered: localization, symmetry, continuity, modulation, relationship with time and with loads/movements, tenderness.

RESULTS

After a descriptive analysis, some pain characteristics were selected individually and others were combined. Only 8 variables were considered for a predictive analysis. Univariate analysis showed that symmetric pain is the most potent discriminating item, with 82.2% sensitivity, 69.2% specificity, a 61% positive predictive value and a 83.3% negative predictive value. A higher probability of RA was present in patients with symmetric pain than in those with asymmetric pain (odds ratio = 7.8). A multivariate analysis performed on 1627 patients showed that a specific clinical pattern of pain (symmetrical pain, pain following joint pressure, mainly present at night or in the morning, continuous) could predict RA patients with a 68.9% likelihood. The lack of these symptoms excluded RA with 92% probability.

CONCLUSION

The clinical pattern of pain defined by us can predict RA with a 70% probability. This value reaches 86% when the variables "pain in a fixed joint" and "pain decreased by load/movements" are added. These results indicate that determining the clinical pattern of pain is a useful screening tool for suspected RA, in particular early in the disease course.

Primary sclerosing cholangitis: clinical presentation, natural history and prognostic variables: an Italian multicentre study. The Italian PSC Study Group

OBJECTIVE

Because large-scale reports of PSC in the Mediterranean area we are still lacking, in this study we evaluated by Kaplan-Meyer analysis the natural history of primary sclerosing cholangitis (PSC) in Italy and by means of other statistical methods we identified the variables most useful in predicting survival of such patients.

DESIGN

Retrospective multicentre study of unselected patients with PSC. Several variables involving sex, age, associated diseases, clinical features, laboratory, cholangiographic and histological findings at presentation and clinical outcome at data recording were collected by means of a detailed questionnaire.

SETTING

16 Italian university and regional hospitals all over the country, thus giving a geographically representative population.

PATIENTS

A total of 117 PSC patients (73 men and 44 women); median age 35 years.

METHODS

Survival analysis was performed by the Kaplan-Meyer method; the prognostic influence on survival of collected data was evaluated by univariate chi(2) analysis with Wilcoxon and log-rank tests. The same prognostic variables were also evaluated by multivariate analysis (Cox model), using a stepwise regression procedure. All statistical analyses were performed using the SAS statistical software.

RESULTS

At presentation 70% of patients were symptomatic; symptoms did not relate to liver histology. Both intra- and extrahepatic bile duct lesions were detected in 46% of patients at cholangiography. Inflammatory bowel disease was found in 54% of symptomatic patients, ulcerative colitis was 36% of total. Clinical outcome (91/117): 15 underwent liver transplantation or died from liver disease (cholangiocarcinoma). Survival at 10 years was 74%. Features of poor prognosis were cholesterol, aspartate aminotransferase (AST), haemoglobin and albumin.

CONCLUSION

PSC in Italy mainly follows a benign course and among clinical features recorded at presentation, serum cholesterol, AST, haemoglobin and albumin may provide some objective criteria to assess disease severity.

Analysis of the DNA content distribution of micronuclei using flow sorting and fluorescent in situ hybridization with a centromeric DNA probe

The DNA content distributions of micronuclei induced in mouse 3T3 cells by ionizing radiation and chemicals was measured by flow cytometry. For a quantitative understanding of these distributions, micronuclei with increasing DNA contents were sorted and analysed for the presence of centromeric signals using fluorescent in situ hybridization (FISH) with a mouse centromeric gamma satellite probe. Radiation-induced micronuclei were found to be produced mainly by chromosome fragments, whereas micronuclei induced by the tear gas chlorobenzylidene malonitrile (CS) were found to be produced mainly by whole chromatids. In contrast, micronuclei induced by vinblastine (VBL) were, according to the shape of their DNA content distributions, produced mainly by whole chromosomes and by combinations of two or more whole chromosomes. With increasing DNA content, micronuclei induced by ionizing radiation also contained one or more whole chromosomes, whereas micronuclei induced by CS or VBL were found to contain several whole chromatids or chromosomes respectively. Computerized random breakage of chromosomes and random combination of chromosome fragments, whole chromatids and whole chromosomes were used according to the FISH results to simulate the measured DNA content distributions of micronuclei. A good agreement was obtained between measured and simulated distributions of micronuclei as well as between results of the measured frequency of micronuclei showing centromeric signals as a function of their DNA content and those predicted by the simulations. These results demonstrate the usefulness of flow cytometry and sorting combined with the FISH technique and computer simulations for producing a more detailed analysis of mechanisms of micronucleus induction.

Radiation-induced structural modifications in dsDNA analysed by FT-Raman spectroscopy

Structural changes of double stranded DNA in aqueous solution induced by ionizing radiation were studied by Fourier-Transform-Raman spectroscopy. In addition to base damage, strand breaks, structural changes, i.e. unstacking of the bases, premelting effects and disordering of the B-form backbone could be observed. The amount of these different kinds of damage depended on the concentration of the DNA solution. Specifically, the following modifications were found depending on the gamma-ray dose and DNA concentration. (1) Intensity increase of the lines of dT (1240 cm-1) and dA (729, cm-1) indicating unstacking of these bases. (2) Intensity and frequency changes of the marker bands of all four bases indicating structural modifications. (3) Intensity decrease of the sugar marker lines showing change of the bonds in the deoxyribose and of bonds between the sugar moiety and the phosphodiester. (4) Intensity decrease of the lines of the phosphodiester groups (1094 and 790 cm-1) with simultaneous appearance of a difference peak at 1080 cm-1 and a new peak at 980 cm-1 suggesting the presence of strand breaks. (5) Intensity decrease of the B-form marker band (approximately 835 cm-1) and new lines at 876 cm-1), at approximately 660 cm-1 (C3'-endo/anti of dG) and at 1312 cm-1 (C3'endo/syn of dA) indicating decrease of the B-form conformation and the developing of partly new secondary forms of the DNA representing a helix-to-coil transition.

Flow cytometric analysis of micronuclei in the CD2+/- subpopulation of human lymphocytes enriched by magnetic separation

An improved flow cytometric method for the scoring of micronuclei in human lymphocytes irradiated in vitro is presented. Because, especially in cultivated human lymphocytes, unspecific DNA-containing debris from dying cells can influence the measured frequency of micronuclei, a preselection of CD2 + population was performed before preparation of the suspension of micronuclei and nuclei. Magnetic separation using anti-CD2 antibody-conjugated magnetic beads were used for this purpose. The results obtained by this improved flow cytometric technique were compared with results obtained by microscopic scoring using the CB technique. No correlation was found when the individual values in unirradiated controls were compared, due mainly to the presence of DNA-containing particles from fragmented cell nuclei and other unspecific debris. The averaged data from nine dose-effect curves simultaneously analysed by both techniques showed a linear-quadratic dose dependence with alpha and beta's that were similar for flow cytometry and for microscopic scoring. Only the constant term was higher for the flow cytometric results. A correlation between both techniques applied to individual data at doses > 0.2 Gy could also be demonstrated. It is concluded that a dose estimation of man exposed to low doses of ionizing radiation can at present not be improved by the flow cytometric technique.

Induction of kinetochore-containing micronuclei by exogenous O6-methylguanine requires conversion of the methylated base to a nucleotide

It has been reported that exogenous alkylated purines, such as O6-methylguanine (O6meG), induce aneuploidy in mammalian cells. It is shown here that the aneugenic effect of O6meG, evidenced by its ability to induce micronuclei in rodent cells, is dependent on its conversion to O6-methyl-guanosine-5'-monophosphate (O6me-5'-GMP) by hypoxanthine-guanine phosphoribosyl transferase (HPRT). This conclusion, in contrast with previous in vitro data showing that O6meG does not seem to be a substrate for HPRT, was based on the following observations: 1) O6meG did not induce micronuclei in HPRT-deficient Chinese hamster cells, but did induce micronuclei in HPRT-proficient cells, and in mouse cells partially or totally deficient in adenine phosphoribosyl transferase; 2) O6meG was not metabolized in HPRT-deficient cells, while in wild-type cells a number of metabolites were detected by high performance liquid chromatography (HPLC) analysis of cold acid extracts, one of them coeluting with O6me-5'-GMP used as a marker; 3) when de novo synthesis of purine nucleotides was inhibited by aminopterin, O6meG sustained the growth of HPRT-proficient, but not of HPRT-deficient, cells; and 4) when HPRT-deficient cells were treated with liposomes charged with O6me-5'-GMP, induction of micronuclei was shown. The finding that methylated guanine exerts its aneugenic action through methylated nucleotide(s) provides an important, though indirect, support to the hypothesis that alkylating agents may induce aneuploidy via nucleotide pool alkylation.

Flow cytometric analysis of bromodeoxyuridine-induced micronuclei

The effects of DNA substitution by the thymidine analogue 5-bromodeoxyuridine (BrdU) on cell cycle progression and micronucleus induction were studied in different mammalian cell cultures. Simultaneous flow cytometric measurements of DNA content and side scatter of nuclei in Chinese hamster embryo (CHE) cells revealed a concentration-dependent temporary block in the G2/M phase of the first cell cycle. NIH 3T3 cells and human amniotic fluid fibroblast-like cells, on the contrary, did not show any cell cycle disturbances in the presence of BrdU. Micronucleus frequency increased as soon as CHE cells started to divide and reached a plateau when all cells have divided. The height of this plateau was almost equal for 60 and 100 microM BrdU. This saturation of micronucleus induction was due to a saturation of BrdU incorporation into DNA already at a doses of 60 microM as shown by the BrdU/Hoechst quenching technique. Indirect immunofluorescent staining of kinetochores with CREST antibodies revealed that nearly all BrdU-induced micronuclei were kinetochore-negative suggesting the presence of acentric chromosome fragments in these micronuclei. DNA distributions of micronuclei measured by flow cytometry showed several peaks representing micronuclei which contain DNA fragments of defined sizes induced by non-random breakage of chromosomes 1 and X as verified by flow karyotyping and C-banding.

Identification and fate of a marker chromosome in methotrexate-resistant V79,B7 cells by flow karyotyping and sorting, metaphase analysis and in situ hybridization

The chromosomes from a methotrexate (MTX)-resistant and its parental V79,B7 Chinese hamster cell line were analysed by the combined use of flow karyotyping and sorting, metaphase analysis and in situ hybridization with a probe for the dihydrofolate reductase (DHFR) gene responsible for methotrexate resistance. A marker chromosome with an elongated arm carrying the amplified DHFR gene was identified by in situ hybridization of metaphase cells of the methotrexate-resistant line. In the flow karyotype the marker chromosome was found as an additional peak with a higher DNA content compared with the largest chromosome of the sensitive line. This was additionally verified by G-banding of the chromosomes sorted from the marker peak. Several other chromosomal rearrangements not associated with the amplified gene could be identified in the methotrexate-resistant line by the combined use of flow karyotyping and metaphase analysis. The fate of the original marker chromosome was studied in cells growing several weeks in the absence of methotrexate, comparing flow karyotyping and metaphase analysis. The original marker chromosome was lost in about 50% of the cells after 5 weeks and in about 60% of the cells after 8 weeks; between 80 and 90% of the cells, however, contained marker chromosomes of various sizes. The MTX-resistance decreased in parallel during loss of the original marker chromosome. In conclusion, the study shows that the power of cytogenetic analysis is improved by the combined use of conventional cytogenetics, molecular cytogenetics and flow cytometry.

The analysis of 10 potential spindle poisons for their ability to induce CREST-positive micronuclei in human diploid fibroblasts

Ten compounds selected for use within a coordinated Commission of the European Communities programme on aneuploidy induction (cadmium chloride, chloral hydrate, colchicine, diazepam, econazole, hydroquinone, pyrimethamine, thiabendazole, thimerosal and vinblastine) were tested for their ability to induce CREST-positive micronuclei in cultured human diploid fibroblasts. Significant increases in CREST-positive micronuclei were produced by cadmium chloride, chloral hydrate, colchicine, diazepam and vinblastine. Thiabendazole produced a significant increase in the ratio of CREST-positive to CREST-negative micronuclei and was also classified as positive. Colchicine, diazepam and chloral hydrate were also tested in V79 Chinese hamster cells, where they all induced CREST-positive micronuclei.

Chromosome rearrangements associated with CAD gene amplification. Experiments with cell hybrids

Resistance to phosphonacetyl-L-aspartate (PALA) is caused by CAD gene amplification. The marker chromosome of a PALA-resistant cell line containing a homogeneously staining region with amplified CAD gene was introduced into PALA-sensitive Chinese hamster cells by microcell-mediated chromosome transfer. Two monochromosomal hybrids containing the marker chromosome in addition to the normal chromosome complement of sensitive cells and 1 tetraploid hybrid containing the complete genomes of donor (resistant) and recipient (sensitive) cells were studied in detail. It was shown that (i) the presence of the marker chromosome was both a necessary and a sufficient condition for the expression of the PALA-resistant phenotype; (ii) the marker chromosome underwent rearrangements in the monochromosomal hybrids, with preferential loss of non-amplified chromosomal regions, while it was not rearranged in the tetraploid hybrid; (iii) unlike the original PALA-resistant cells obtained after long-term selection in the presence of PALA, the PALA-resistant hybrids did not show chromosomal aberrations of other than the marker chromosome. This result indicates that chromosomal aberrations may be due to the selective procedure and is not an inherent property of cells containing amplified genes.

Induction of kinetochore positive and negative micronuclei in V79 cells by the alkylating agent diethylsulphate

The induction by diethylsulphate of micronuclei derived from acentric fragments or from whole chromosomes was studied in Chinese hamster V79 cells using autoantibodies from the serum of a scleroderma patient (CREST-syndrome) to detect centromere--kinetochore structures. Centromere-containing micronuclei appeared early after treatment and plateaued both earlier and at lower level than centromere-lacking micronuclei. The frequency of centromere-containing micronuclei was in good agreement with that of mitotic chromosome displacement, suggesting that a high proportion of displaced chromosomes were transmitted to the cytoplasm of one of the two daughter cells, where they gave rise to micronuclei. On the contrary, centromere-lacking micronuclei were more frequent than what could be expected from chromosome fragments observed in mitotic stages.

The induction of numerical chromosome aberrations in human lymphocyte cultures and V79 Chinese hamster cells by diethyl sulfate

Human lymphocyte cultures were treated with increasing concentrations of diethyl sulfate (DES) at different times after stimulation with phytohemagglutinin (0, 24 and 45 h) and were scored for numerical chromosomal aberrations at different culture times (52, 72 and 96 h). A total of 3500 metaphases were analyzed. A statistically significant (p less than 0.01) increase in hypodiploid and hyperdiploid metaphases was found throughout the tested dose range (0.1-3 mM DES); the increase in polyploid metaphases was statistically significant at 1 mM (p less than 0.05) and 3 mM (p less than 0.01) DES. In human lymphocytes treated in Go, DES also induced chromatid breaks as well as micronuclei. In V79 Chinese hamster cells, DES induced micronuclei and polyploidy.

New evidence for the presence of chromosomes in micronuclei of human and Chinese hamster cells

The aim of this work was to demonstrate the presence of intact chromosomes in micronuclei. Such evidence was based on the re-expression of metaphase chromosomes by micronuclei fused with whole cells. Three different experimental approaches were used; they differed only in the criteria used to discriminate between the chromosomes of micronuclear origin and those present in the cell to which micronuclei were fused. These methods involved the expression of: (a) human chromosomes in mouse cells, (b) radioactively labelled human chromosomes in unlabelled human lymphocytes and (c) Chinese hamster chromosomes in Chinese hamster cells with differentially stained chromosomes. With all methods, evidence for the presence of one or few chromosomes in micronuclei was obtained.