[Evaluation of the association of a serum marker and second trimester ultrasonography for the screening of trisomy 21 in women of less than 38 years. Prospective study of 5,163 patients]

OBJECTIVES

Use of serum markers alone for trisomy 21 screening programs leads to a high rate of amniocentesis. Adding a second parameter (ultrasonography during the second trimester) might reduce this rate yet retain satisfactory sensitivity. This work was conducted to evaluate the pertinence of associating serum hCG level between 16 and 17 weeks gestation and morphological ultrasonography between 18 ans 20 weeks gestation.

METHOD

A prospective study was conducted in 5,163 pregnant women aged over 38 years. A morphological ultrasonography was performed in all patients whose hCG level > 1/150 indicated a risk. An amniocentesis was proposed if an anomaly was detected at ultrasonography.

RESULTS

Serum hCG was above the risk threshold retained in 11.9% of the patients and among these patients at least one anomaly was detected at ultrasonography in 12%. An amniocentesis was performed in 1.4% of all patients. The positive predictive value of the screening test was 20%.

CONCLUSION

Combining a serum marker and ultrasonography during the second trimester allows a reduction in the rate of amniocentesis compared with screening with serum markers alone. Sensitivity for detecting trisomy 21 remains satisfactory.

Radiosterilization dosimetry of vitamins: an ESR study

PURPOSE

As an alternative to heat and gas exposure sterilization, ionizing radiation is gaining interest as a sterilization process for medicinal products. Detection and dosimetry of pharmaceutical radiosterilization is a growing concern for numerous government regulatory agencies world-wide.

MATERIALS AND METHODS

Equations to describe the ESR curves versus the dose and storage time were developed using mathematical procedures. For this investigation six vitamins (riboflavin, biotin, thiamine mononitrate, thiamine hydrochloride, folic acid and pyridoxine) were chosen as models.

RESULTS

The yield of free radicals is in the range 1.7 10(18)-7.3 10(19) radicals mol(-1) (G values from 0.0003 to 0.025 mol J(-1)). Apart from qualitative detection, ESR spectrometry can be used for dose estimation; when an exponential function is applied to the variation of peak-to-peak amplitude on dose, the function correlates well with the data. Tests were carried out to investigate whether storage has an effect on the concentration of free radicals. In order to estimate the time limit of detection, decay curves were modelled using a bi-exponential function. From this, the time limit from the irradiation (25 kGy) for identification of irradiated vitamins by ESR was evaluated. In the commercial drug market, radicals should be detected for up to 2 years after irradiation; this probably will be the case for the vitamins studied, with the exception of folic acid and pyridoxine.

CONCLUSION

The detection method based on ESR dosimetry seems promising. ESR dosimetry requires only small samples, and minimal time and effort for sample preparation; the measurement is non-destructive.

Ionic and metabolic imbalance as potential factors of ischemia reperfusion injury

This study examined the influence of metabolic substrates on the effects of trimetazidine on functional and metabolic aspects of the ischemic reperfused heart. Isovolumic rat hearts were submitted to a 30-minute period of global mild ischemia (coronary flow decreased by an average of 70%) and then reperfused at constant preischemic coronary flow rate. Either glucose (11 mM) or glucose and palmitic acid (0.1 mM) were used as metabolic substrates. Trimetazidine (6 x 10(-7)M) markedly reduced the increase in diastolic pressure that occurred on reperfusion after the ischemic episode, whatever the exogenous substrate used. However, in those hearts that received fatty acid, the postischemic increase in diastolic pressure was abolished. Ischemia-induced increase in acyl carnitine levels-determined as indicators of fatty acid utilization by myocardial cells-was significantly decreased by trimetazidine in those hearts receiving fatty acid. Also, similar effects to those of trimetazidine on the postischemic increase in diastolic pressure and on tissue levels of acyl carnitine were obtained in the presence of dichloroacetate. Moreover, the presence of trimetazidine was associated with a reduction in the intracellular pH decrease during ischemia in those hearts receiving fatty acid. Combined with previous studies, these results suggest that an improved metabolic balance by trimetazidine may well consequently decrease the ionic imbalance after a transient period of ischemia.

Electron spin resonance detection of radiosterilization of pharmaceuticals: application to four nitrofurans

The detection and dosimetry of radiosterilization of pharmaceuticals is a growing concern to numerous government regulatory agencies worldwide. In the absence of suitable detection methods, attention was focused on electron spin resonance (ESR) spectrometry. This paper reports experimental data on ESR dosimetry of irradiated nitrofurans (nitrofurantoin, nifuroxazide, nifurzide and nifurtoinol). Whereas the ESR spectrum of a non-irradiated sample shows no signal, a signal, that is dependent on the irradiation dose is observed with irradiated samples. The number of free radicals was calculated by comparing the second integral from radiosterilized samples and a Bruker strong pitch reference; the values were in the range 1.1 x 10(18)-1.5 x 10(19) radicals mol-1 (G = 0.003-0.03). In addition to qualitative detection, ESR spectrometry can be used for dose determination. When a bi-exponential function is applied to the variation of the peak-to-peak amplitude versus dose, the function correlates well with the data. However, an exponential function, easier to use than a bi-exponential function, will probably be sufficient for dose determination by retrospective dosimetry. Decay of radicals upon storage was modelled using a bi-exponential function. From this, the time limit from the irradiation (25 kGy) for identification of irradiated nitrofurans by ESR can be evaluated. With regard to the commercial aspects of drugs, radicals should be detected up to 2 years after irradiation. The kinetic decrease makes discrimination between irradiated and non-irradiated nitrofurans possible even after storage for up to 2 years, except for nifurtoinol.

ESR spectroscopy applied to the study of pharmaceuticals radiosterilization: cefoperazone

As an alternative to heat and gas exposure sterilization, ionizing radiation is gaining interest as a sterilization process for medicinal products. Nevertheless, essentially for economic profits, an unauthorized and uncontrolled use of radiation process may be expected. In this context, it is necessary to find methods distinguishing between irradiated and unirradiated pharmaceuticals and, in the absence of suitable detection methods, our attention was focused on ESR spectrometry. In this paper, we examine the potential of ESR as an analytical tool in cefoperazone radiosterilization; this cephalosporin is a potential candidate for radiation treatment due to its thermosensitivity. While the ESR spectra of unirradiated sample present no intensity, a signal, dependent of the irradiation dose, is found exclusively in irradiated samples. The number of free radicals (2 x 10(17) radicals per g at 25 kGy) was estimated by comparison of the second integral from radiosterilized samples and DPPH. From this, the G-value could be estimated to 0.3. Limit of detection and limit of quantification are 0.5 kGy and 1 kGy, respectively. Aside from qualitative detection, ESR can be used for dose estimation. The dose-ESR response curves can be simulated by bi-exponential or power functions and the linear function can't be used for simulation even for low doses. Decay of radicals upon storage were simulated using bi-exponential function. The limit of detection of free radicals after irradiation at 25 kGy is 140 days.

Radiation-induced effects on cefotaxime: ESR study

As an alternative to heat and gas exposure sterilization, ionizing radiation is gaining interest as sterilization process for medicinal products. Detection and dosimetry of pharmaceuticals radiosterilization is a growing concern to numerous government regulatory agencies worldwide. In this context, it is necessary to find methods distinguishing between irradiated and nonirradiated pharmaceuticals. In the absence of suitable detection methods, our attention was focused on electron spin resonance (ESR) spectrometry. A third generation cephalosporin, cefotaxime, was chosen as model; this antibiotic is a potential candidate for radiation treatment due to its thermosensitivity. While the ESR spectra of a nonirradiated sample presents no signal, a signal, dependent of the irradiation dose, is found in irradiated samples. The number of free radicals was estimated by comparing the second integral from radiosterilized samples and a diphenyl-picrylhydrazyl reference. Estimation of the number of free radicals gives 1.9 x 10(20) radicals mol(-1) at 20 kGy. From this result, the G-value (number of radicals (100eV)(-1)) could be estimated to 0.3. Aside from qualitative detection, ESR spectrometry can be used for dose estimation. When quadratic, exponential or bi-exponential functions are applied to the variation of peak to peak amplitude vs. dose, these functions correlate well with the data. However, it is important to notice that linear function correlates well with the data for doses lower than 20 kGy. Since the radiation dose selected must be always based upon the bioburden of the products and the degree of sterility required (EN 552 and ISO 11137) 25kGy could no longer be accepted as a "routine dose" for sterilizing a pharmaceutical. Doses from 6kGy (ISO 11137) could be investigated and linear regression would appear to be the least expensive route to follow. The free radicals concentration appeared to not decrease during the 57 days of storage; the number generated during the irradiation allows the detection of radiosterilized cefotaxime up to two years after irradiation.

TAL1 expression does not occur in the majority of T-ALL blasts

The TAL1 gene is disrupted by translocation or deletion (tal(d)) in up to 30% of T-cell acute lymphoblastic leukaemia (T-ALL), leading to aberrant transcriptional activation, as a SIL-TAL1 fused transcript in tal(d). It has been suggested that TAL1 transcription occurs in approximately 50% of a T-ALLs without apparent rearrangement. SIL-TAL1 was positive in 15/60 (25%) of T-ALL, whereas wild-type TAL1 transcripts were detected in all 13 SIL-TAL1 and in 19/43 (44%) T-ALL without SIL-TAL1. To investigate the cellular origin of TAL1 we exploited the fact that GATA1 and TAL1 are co-ordinately expressed in non-lymphoid haemopoietic cells, whereas only the latter is found in T-ALL. GATA1 was detected in 10/23 (43%) TAL1-negative T-ALLs but in 17/19 (89%) 'unexplained' TAL1-positive cases, suggesting a common non-lymphoid cellular origin. Immunocytochemical analysis with a TAL1-specific monoclonal antibody showed nuclear expression in the blasts of 10/34 (29%) cases, including 8/10 SIL-TAL1+ and two RT-PCR TAL1+, SIL-TAL1- cases. In the remaining cases TAL1 expression was restricted to a minor population (< 5%) of larger, strongly TAL1-positive cells which comprised erythroid cells, CD34+ CD3- precursors and an unidentified TAL1+ CD45- population which morphologically resembled monocytes/macrophages. We therefore suggest that appropriate diagnostic evaluation of T-ALL should include molecular detection of SIL-TAL1 transcripts and in situ immunocytochemical detection of TAL1 protein expression by leukaemic blasts. This approach will enable accurate analysis of the prognostic significance of TAL1 deregulation in T-ALL.

Antiapoptotic effect of ectopic TAL1/SCL expression in a human leukemic T-cell line

Aberrant expression of TAL1 occurs frequently in human T-cell acute lymphoblastic leukemia. The effect of TAL1 expression in the T-cell lymphoid precursor, however, remains unclear. In the current study, we have developed TAL1 stable transfectants in a human immature T-cell lymphoid cell line. Whereas no effect on proliferation, cell culture density, or cell cycle was detected, the transfectants were more resistant than the parental cell line to apoptosis induced by chemotherapeutic agents including etoposide, daunorubicin, doxorubicin, cytosine arabinoside, methotrexate and vincristine and also to apoptosis induced by Fas/CD95 cross-linking. This effect was independent of the cytostatic effects of the drugs. The basic domain-deleted transfectants did not demonstrate altered sensitivity, suggesting that DNA binding was necessary for resistance to apoptosis. The ability to alter the response to a wide range of cell death-inducing stimuli suggests that TAL1 acts at a late stage of the apoptotic cascade. These data therefore provide direct evidence of an antiapoptotic effect of ectopic TAL1 expression in response to cytotoxic agents, thus providing insight into its oncogenic function in T-cell acute lymphoblastic leukemia and a novel experimental model to further investigate the underlying mechanisms. These data also have potential practical significance for cytotoxic therapy of this disorder.

Prophylactic use of itraconazole for the prevention of invasive pulmonary aspergillosis in high risk neutropenic patients

Invasive pulmonary aspergillosis (IPA) is an increasing cause of morbidity and mortality in patients with hematologic malignancies. A major program of construction work close to our unit prompted us to evaluate the efficacy of itraconazole prophylaxis in preventing IPA in these patients. During September 1994 to December 1995, 77 patients undergoing 96 neutropenic episodes (mean duration, 19.3 days +/- 9.1) received itraconazole as antifungal prophylaxis. All patients were treated in laminar air flow rooms. Itraconazole was administered at a loading dose of 600mg/d, (day 1 to day 3) and 400mg/d on the following days, in 87 instances. In the remaining episodes, the daily dose was 200 or 400mg. Oral doses were adjusted to reach a plasma itraconazole level (PIL) above 1000ng/l. In cases of inadequate PIL or poor oral intake, IV AmphoB was started at a 20 mg daily dose. Five cases of IPA (proven n = 2, probable n = 3) were observed. This represents an incidence of 5.2% of the total number of episodes. One out of 67 (2%) treatment episodes with adequate PIL were associated with IPA as compared to 4 of 29 (14%) episodes with inadequate PIL, (p < 0.02). AmphoB was added in 28 cases because of low PIL (n = 25), and/or antibiotic-resistant fever persistent pulmonary infiltrate (n = 8). These results need to be interpreted with caution, because of the absence of randomization or a control group. The efficacy of Itraconazole in neutropenic patients with high risk IPA has to be confirmed on larger and prospective studies.

Acute respiratory failure caused by secondary alveolar proteinosis in a patient with acute myeloid leukemia: a case report

Pulmonary alvelolar proteinosis (PAP) is a rare cause of chronic respiratory failure due to progressive alveolar accumulation of a periodic acid-schiff (PAS) positive proteinaceous material. In some cases, the rapid accumulation of intra-alveolar material leads to acute respiratory failure (ARF). We report the causative role of secondary PAP in the case of a 26-year-old man with acute myeloid leukemia who developed fever, increased serum lactate dehydrogenase level and ARF, and required mechanical ventilation. The diagnosis of PAP was established by the examination of material obtained by bronchoalveolar lavage (BAL). Respiratory improvement occurred several days after the patient had recovered from neutropenia. This report underlines the importance of the early diagnosis of PAP as a potential cause of ARF in leukemic patients. Adequate stain on BAL fluid provides the diagnosis and avoids repeated invasive procedures and inappropriate treatments.

Backs to the future? Reflections on women, ageing and nursing

There is now a certain amount of evidence to support the contention that ageism is not only rife amongst the population at large, but also amongst many of those who care for older people in a professional capacity. Given that many of these professionals are women caring for other women -- and nursing is a prime example -- this should at the very least give us serious cause for concern. This paper explores the relationship between 'ageing women' and 'old women' from the point of view of personal and professional attitudes and practices. It examines the proposition that until we, as women, fully explore and understand our own attitudes towards ageing and old age, we cannot work in ways which are truly beneficial and empowering for the older women in our care. The purpose of the paper is threefold. First, it reviews what is a relatively limited body of literature and research on this topic. Second, it reports on the preliminary findings from an exploratory study examining the attitudes of female nurses to their own ageing. Finally, it reflects further on the issues raised and considers some of the ways in which we can begin to address and confront the challenges which being 'ageing women' and 'aged women' in late 20th century Britain presents.

Attitudes toward gun control and personality

In a sample of 65 undergraduates, a negative attitude toward guns was associated with lower scores on Psychoticism.

BCR-ABL and constitutively active erythropoietin receptor (cEpoR) activate distinct mechanisms for growth factor-independence and inhibition of apoptosis in Ba/F3 cell line

The interleukin-3 dependent murine Ba/F3 cell line has been widely used as an experimental model of cell transformation by BCR-ABL oncogenes as assessed by induction of growth-factor-independence and inhibition of apoptosis in vitro. The signaling pathways used by BCR-ABL oncogenes to exert these effects are unknown. To gain insights into this phenomenon, we have introduced the p190- and p210-encoding BCR-ABL oncogenes as well as the constitutively activated oncogenic murine erythropoietin receptor (cEpoR) into Ba/F3 and compared the behavior of individual clones in response to apoptotic stimuli. Both p210 and p190 BCR-ABL vectors induced IL-3-independent growth and the same result was obtained with the cEpo-R vector. Individual clones of Ba/F3 cells expressing BCR-ABL exhibited significant resistance to apoptosis induced by either etoposide, serum deprivation or growth-factor withdrawal. In contrast, Ba/F3 cells expressing the constitutively active cEpoR behaved like parental Ba/F3 cells undergoing apoptosis when similarly treated with etoposide or upon serum deprivation. Bc12 and Bax levels were similar in all BCR-ABL and cEpoR-transfected clones. However, in band-shift assays, nuclear extracts from growth-factor-independent Ba/F3 clones expressing cEpoR had no detectable STAT activity as opposed to the constitutive STAT activation detected in all Ba/F3 clones expressing p210 or p190 BCR-ABL. Our results indicate that although both constitutively activated cEpoR and BCR-ABL oncogenes induce growth-factor independence in Ba/F3 cells, only BCR-ABL is able to protect cells from etoposide and serum-deprivation-induced apoptosis and induce a strong constitutive activation of STAT factors, suggesting a role for these molecules in the anti-apoptotic activity of BCR-ABL.

Simultaneous SIL-TAL1 RT-PCR detection of all tal(d) deletions and identification of novel tal(d) variants

Site-specific deletions of the 5' part of the TAL1 gene (tal(d)) are among the most frequent non-random genetic abnormalities in T-cell acute lymphoblastic leukaemia (T-ALL). They are usually detected by PCR from DNA with several primer pairs or by Southern blot analysis. Since tal(d) lead to expression of a SIL-TAL1 fusion transcript, irrespective of the genomic breakpoint, we have used a single monoplex RT-PCR reaction to screen 55 T-ALL patients at diagnosis. SIL-TAL1 transcripts were demonstrated in 12 (22%) cases, including 7/27 (26%) children <15 years of age, 2/8 (25%) adolescents and 2/17 (12%) adults aged >20 years. SIL-TAL1 RT-PCR was preferrable to tal(d) DNA PCR since it allowed the simultaneous detection of tal(d), tal(d2) and two previously undescribed tal(d) variants. SIL-TAL1 RT-PCR screening should therefore increase the detection rate of tal(d) by approximately 15-20%, with an at least comparable sensitivity to tal(d) genomic PCR, and represents a more practical and economic alternative to multiple DNA PCRs or Southern blotting when incorporated into molecular screening for multiple transcripts at diagnosis.

Radiation effects on dopamine and norepinephrine

PURPOSE

Radiation sterilization is becoming increasingly popular for the sterilization of many pharmaceutical products. We have investigated the gamma radiation induced effects on dopamine and norepinephrine by ESR spectroscopy.

RESULTS AND DISCUSSION

Equations to describe the evolution of the ESR curves versus doses and time of storage are presented. Linear regression is, for dopamine hydrochloride, applicable for doses ranging from 10 to 25 kGy. Since the radiation dose selected must always be based upon the bioburden of the products and the degree of sterility required, doses in the range 10-25 kGy could be investigated and linear regression would appear to be the least expensive route to follow and gives good results. The comportment of noradrenaline bitartrate is more complex and the use of linear regression would appear more hazardous especially for low doses. For doses higher than 25 kGy, a more general equation is required. Power function using only 2 parameters could give good results but must be validated. Decay kinetics for radicals versus storage were considered. Non-homogeneous kinetics with time dependent rate constant and bi-exponential function appeared valid to reproduce the decay of radicals for, respectively, dopamine and norepinephrine.

CONCLUSIONS

It is worth noting that, at present, ESR is the only technique which proved to be suitable for identification and quantification purposes in irradiated pharmaceuticals. Moreover, other features such as sensitivity, precision, ease and non-destructive readout make ESR superior to other proposed analytical techniques.

ESR dosimetry of irradiated ascorbic acid

PURPOSE

As an alternative to heat and gas exposure sterilization, ionizing radiation is gaining interest as a sterilization process for medicinal products. The aim of this work was to develop equations to describe the ESR curves versus dose and storage time after gamma irradiation of ascorbic acid. Several ESR data sets previously acquired in this laboratory were adopted to check the performance of the models.

RESULTS

Limit of detection and limit of discrimination are respectively 0.5 kGy and 2 kGy for ascorbic acid. Linear regression is applicable for doses lower than 25 kGy. Since the radiation dose selected must always be based upon the bioburden of the products and the Degree of Sterility required (ANSI/AAMI/ISO 11137), doses in the range 5-25 kGy could be investigated and linear regression would appear to be the least expensive route to follow and gives good results. Quadratic fit, power function, exponential function and bi-exponential functions are of more general applicability to predict irradiation dose. Decay kinetics for radicals versus storage were considered. Nonhomogeneous kinetics with time-dependent rate (diffusion-controlled second-order reaction) and bi-exponential function appeared valid to reproduce the experimental data. Discrimination between irradiated and unirradiated ascorbic acid is possible after a storage of 800 days.

CONCLUSIONS

It is worth noting that, at present, ESR is the only technique which proves to be suitable for identification and quantification purposes in irradiated pharmaceuticals. Moreover, other features such as sensitivity, precision, ease and non-destructive readout make ESR superior to other proposed analytical techniques.

Cellular and molecular regulation of serotonin N-acetyltransferase activity in chicken retinal photoreceptors

Serotonin N-acetyltransferase (AA-NAT; arylalkylamine N-acetyltransferase; EC 2.3.1.87) is the penultimate enzyme in melatonin synthesis and large changes in the activity of this enzyme appear to regulate the rhythm in melatonin synthesis. Recent advances have made it possible to study the mRNA encoding chicken AA-NAT, which has only been detected in the retina and pineal gland. Within the retina, AA-NAT mRNA is expressed primarily in photoreceptors. The levels of chicken retinal AA-NAT mRNA and activity exhibit 24-hour rhythms with peaks at night. These rhythms appear to reflect circadian clock control of AA-NAT mRNA abundance and independent effects of light and darkness on both mRNA levels and enzyme activity. The effects of darkness and light may occur through alterations in cAMP-dependent protein phosphorylation, which increases AA-NAT activity in photoreceptor cell cultures. The cAMP-dependent increase of AA-NAT enzyme activity reflects, at least in part, increased mRNA levels and inhibition of enzyme inactivation by a posttranslational mechanism. This review discusses a hypothetical model for the cellular and molecular regulation of AA-NAT activity by circadian oscillators and light in chicken retinal photoreceptor cells.

Radiation sterilization of formoterol

PURPOSE

Radiation sterilization is becoming increasingly popular for the sterilization of many pharmaceutical products. We have investigated the gamma radiation induced effects on formoterol fumarate by HPLC and ESR spectroscopy.

RESULTS AND DISCUSSION

Numerical simulation of the evolution of the ESR signal versus dose was performed using linear regression, quadratic fit and power function. The shape of the dosimetric curve is linear in the range 5-30 kGy. Owing to the weak number of free radicals generated during the irradiation, the accuracy of measurements is low. For a dose of 25 kGy, discriminating irradiated from unirradiated samples is possible if the storage period is less than 250 days. The comparison between chromatographic profiles of irradiated and unirradiated samples showed minor differences.

CONCLUSIONS

From our preliminary results, radiosterilization of formoterol fumarate may be technically feasible. Estimation of the irradiation dose by ESR may be possible but, due to the weak number of free radicals generated during the irradiation, the accuracy of measurements appeared low.