A comparative analysis of FISH, RT-PCR, and cytogenetics for the diagnosis of bcr-abl-positive leukemias

Philadelphia (Ph) chromosome-positive leukemias, with the bcr-abl gene translocation, have a dismal prognosis. The identification of Ph-positive patients is vitally important because only aggressive therapeutic approaches, such as allogeneic bone marrow transplantation, may result in long-term disease-free survival. Routine diagnostic methods, such as Southern blot analysis and cytogenetics, may lead to false-negative results. Reverse transcriptase-polymerase chain reaction (RT-PCR) analysis is considered the most sensitive tool for the detection of the bcr-abl translocation, and it is widely used alone or in combination with karyotyping or Southern blot analysis to identify Ph-positive cases. In this study, we used fluorescence in situ hybridization (FISH) with BCR and ABL double-color probes for detecting Ph-positive leukemias. The FISH results were compared with the results of cytogenetic and RT-PCR analyses in 75 patients with leukemia or other myeloproliferative syndromes (chronic myeloid leukemia, 30; acute lymphoblastic leukemia, 24; acute myelogenous leukemia, 6; essential (hemorrhagic) thrombocythemia, 12; chronic myelomonocytic leukemia, 2; and polycythemia vera, 1). FISH analysis proved to be simple, extremely reliable and sensitive; bcr-abl fusion detection was successful in the presence of all types of molecular junctions i.e., (b2a2, b3a2, and e1a2). Furthermore, a Ph-positive case that proved fusion negative by RT-PCR was identified as positive by FISH. The sensitivity of RT-PCR and FISH related to Ph-positive cases were 97% and 100%, respectively. Regarding specificity, in 4 (5%) of 75 patients, RT-PCR provided false-positive results. Cross-contamination was identified because a new specimen was harvested and reanalyzed when FISH, cytogenetics, and RT-PCR results were contradictory. We believe FISH is an optimal diagnostic method to detect bcr-abl translocation that can be used alone or to validate the results of RT-PCR analysis.

Axonal transport blockade in the neonatal rat optic nerve induces limited retinal ganglion cell death

Optic nerve section in the newborn rat results in a rapid apoptotic degeneration of most axotomized retinal ganglion cells (RGCs). This massive process of neuronal death has been ascribed mainly to the interruption of a trophic factor supply from target structures rather than to the axonal damage per se. To distinguish between these two possibilities, we induced a reversible axonal transport blockade in the developing optic nerve by topical application of a local anesthetic (lidocaine). Light and electron microscopy showed no alterations in the fine structure of treated optic nerves. Retinae of treated and control rats were stained with cresyl violet and examined at different times after surgery. We found that axonal transport blockade induced only a limited number of pyknotic RGCs. Degeneration of these cells was completely prevented by inhibiting protein synthesis during lidocaine application. We conclude that the rapid degeneration of RGCs after axotomy can be ascribed only partly to the loss of retrogradely transported trophic factors.

Transplant of polymer-encapsulated cells genetically engineered to release nerve growth factor allows a normal functional development of the visual cortex in dark-reared rats

Visual experience is necessary for the normal development of the visual system. Dark-reared mammals show abnormal vision when reintroduced into a normal environment. The absence of visual experience during the critical period results in reduced and/or inappropriate neural responses in visual cortical neurons. The change in electrical activity induced by dark rearing is probably reflected by the modulation of specific unknown molecules. Neurotrophins are present in the developing visual cortex and their production depends on visually driven electrical activity. Recent findings support the possibility that an important link between electrical activity in the visual pathway and correct development of visual properties is represented by neurotrophins. We advance the hypothesis that the visual abnormalities present in dark-reared animals could be due to a decreased production of a neurotrophin secondary to the lack of visual stimulation. We report that some properties of visual cortical response such as receptive field size, orientation selectivity, adaptation to repeated stimulation, response latency and visual acuity are virtually normal in dark-reared rats transplanted with polymer-encapsulated baby hamster kidney cells genetically engineered to release nerve growth factor.

A microgranular variant of acute promyelocytic leukemia with atypical morpho-cytochemical features and an early myeloid immunophenotype

This report describes a unique case of acute promyelocytic leukemia (APL) showing elusive morphologic features, an atypical pattern of cytochemical reactions, and a previously unreported immunophenotype consistent with a very early myeloid form: CD13 (+), CD33 (+), CD9 (+), CD2 (+), HLA-DR (-), CD34 (+), CD117 (+), and TdT (+). The diagnosis of AML M3 variant was made only after genotypic analyses revealed the PML/RAR alpha rearrangement associated with the typical (15;17) (q22;q21) translocation. This example of 'asynchronous differentiation' emphasizes the need for a multiparameter approach to the diagnosis of acute leukemia.

Temporal aspects of contrast visual evoked potentials in the pigmented rat: effect of dark rearing

Cortical visual evoked potentials (VEPs) in response to gratings temporally modulated in counterphase were recorded in normal and dark-reared pigmented rats. Temporal modulation was either sinusoidal (0.25-15 Hz, steady state condition) or abrupt (0.5 Hz, transient condition). In normals, the amplitude spectrum of contrast VEPs has two peaks (at about 0.5 and 4 Hz) and a high temporal frequency cut-off of the order of 11 Hz. The VEP phase lags with temporal frequency, showing two different linear slopes for separate frequency ranges (0.25-1 Hz and 1-7 Hz) centred on the peaks of the curve. The different slopes correspond to apparent latencies of 500 and 136 msec, respectively. Dark rearing reduced the cut-off frequency by about 3 Hz and increased apparent latencies by about 42 msec in the low temporal frequency range and 30 msec in the high temporal frequency range. The latency of the first peak of transient VEPs was increased by about 47 msec. Results indicate that the frequency response of rat contrast VEPs is qualitatively similar to that of other mammals (including human), albeit shifted to a lower range of temporal frequencies. Dark rearing significantly alters the VEP temporal characteristics, suggesting that visual experience is necessary for their correct development.

Minimally differentiated acute myeloid leukemia (AML-M0): comparison of 25 cases with other French-American-British subtypes

We compared the immunophenotypic and karyotypic features of 25 cases of minimally differentiated acute myeloid leukemia (AML-M0) with those of 247 cases comprising all AML French-American-British (FAB) classification. Myeloperoxidase (MPO) was detectable with a specific monoclonal antibody in all cases of AML-M0, whereas CD13 and CD33 were both negative in 4 of the 25 cases. Thus, anti-MPO reliably detects minimal myeloid differentiation in AML-M0. CD34 and terminal deoxynucleotidyl transferase (TdT) were more frequently expressed in AML-M0 (96% and 68% of the cases, respectively) than in the other FAB subsets (P < .001 for both). By contrast, GP-170 and CD7 were less frequently expressed in AML-M0 than in FAB classes such as M1, M4, and M5 (P = .02 and .003, respectively). A total of 80% of AML-M0 cases carried lymphoid markers (including TdT), and 48% showed a coordinate positivity for two or more of them. CD2, CD5, CD10, and CD19 were expressed in a similar fashion among the different FAB groups, whereas CD4 expression was significantly more frequent in AML-M0, AML-M4, and AML-M5 (P = .014). AML-M0 was characterized by a more frequent occurrence of complex karyotypes. In addition, approximately 20% of cases had TdT positivity, complex karyotypes, and anomalies of chromosome 5 and/or 7, a pattern not observed in the other FAB subsets. Finally, 80% of anomalies of chromosome 5 and/or 7 in AML-M0 were comprised within complex karyotypes, whereas only 13% of the remaining FAB cases carried this feature. In summary, AML-M0 frequently expresses immunophenotypic and karyotypic aspects that are likely to identify a "stem cell" pattern.

Transplant of Schwann cells allows normal development of the visual cortex of dark-reared rats

Visual experience is necessary for the correct development of the visual cortex. Dark-rearing from birth affects normal maturation of the functional properties of mammalian visual cortex: cortical cells show rapid habituation to repeated stimulation, decreased orientation selectivity, and enlarged receptive fields. Spatial resolution and response latency are also impaired. Recent experiments have demonstrated that visual deprivation reduces the expression of neurotrophins in the visual cortex. We formulated the hypothesis that visual experience drives the maturation of functional properties of the visual cortex by regulating cortical levels of neurotrophins. If this hypothesis is correct, exogenous supply of neurotrophins during dark-rearing from birth should prevent, or at least ameliorate, the effects of a lack of visual experience. Since Schwann cells are efficient biological minipumps of neurotrophic factors, we transplanted 1.0 or 1.5 x 10(6) Schwann cells or infused vehicle solution as a control into the lateral ventricles of 13 day old rats reared in total darkness from birth until the end of the critical period (postnatal day 45). Single-cell responses and visual-evoked potentials were recorded from the binocular zone of the primary visual cortex of each group. We found that in Schwann cell-transplanted animals all parameters tested were significantly improved upon those of dark-reared control rats and were in the range of normal adult values. Thus, Schwann cell transplant contributed to the normal development of visual response properties in the visual cortex, compensating for a complete absence of visual experience.

The visual response of retinal ganglion cells is not altered by optic nerve transection in transgenic mice overexpressing Bcl-2

Attempts to rescue retinal ganglion cells from retrograde degeneration have had limited success, and the residual function of surviving neurons is not known. Recently, it has been found that axotomized retinal ganglion cells die by apoptotic mechanisms. We have used adult transgenic mice overexpressing the Bcl-2 protein, a powerful inhibitor of apoptosis, as a model for preventing injury-induced cell death in vivo. Several months after axotomy, the majority of retinal ganglion cells survived and exhibited normal visual responses. In control wild-type mice, the vast majority of axotomized retinal ganglion cells degenerated, and the physiological responses were abolished. These results suggest that strategies aimed at increasing Bcl-2 expression, or mimicking its function, might effectively counteract trauma-induced cell death in the central nervous system. Neuronal survival is a necessary condition in the challenge for promoting regeneration and eventually restoring neuronal function.

Continuous low-dose subcutaneous desferrioxamine (DFO) to prevent allergic manifestations in patients with iron overload

In some patients compliance to subcutaneous desferrioxamine therapy is reduced because of allergic symptoms. Effective drug desensitization consists of bringing patients to tolerate the same mode of administration. We evaluated three thalassemic patients with severe allergies to desferrioxamine. Each patient received weekly three prefilled infusors with desferrioxamine 4 g/48 m1/48 h for s.c. therapy. Follow-up was performed for 12 consecutive weeks. During follow-up no allergic events were noted. The s-ferritin levels decreased from 2583 micrograms/l +/- 485 to 1916 micrograms/l +/- 275 (mean decrease 25.8%, p = 0.038). Compliance to the infusional system was excellent. Our results show that continuous infusion of desferrioxamine using a new infusional delivery system is effective in preventing allergic reactions and in reducing iron overload.

FISH analysis for CML monitoring?

Conventional cytogenetics is considered the gold standard for evaluating CML during interferon (IFN) treatment. Drawbacks to this approach are the small number of metaphases available during IFN therapy and the impossibility of scoring interphase cells. We applied, besides cytogenetics, double-color FISH (dc-FISH) detection of BCR-ABL gene fusion to monitor 20 CML patients on IFN. dc-FISH easily detected 200 cells per specimen, while with cytogenetic examination a mean of 16.1 mitoses per sample were scored. Though the correlation of dc-FISH and cytogenetic data was good (r = 0.77, p < 0.001), the discrepancy between the two methods as regards the proportion of leukemic cells in the marrow was often important dc-FISH detected a relevant proportion of BCR-ABL+ cells in three patients classified as complete cytogenetic responders and showed that, after 9-12 months of IFN treatment, a significant reduction of BCR-ABL+ cells was present in all the 20 patients tested. This might suggest that all CML patients are potentially responsive to IFN. Though more data are required, we think that dc-FISH is more informative than cytogenetic analysis for CML monitoring. Notably because of the simplicity of the procedure, this method could be easily standardized among different laboratories, thus permitting cross-comparison in therapeutic trials.

Long-term survival of retinal ganglion cells following optic nerve section in adult bcl-2 transgenic mice

The bcl-2 gene codes for a protein that acts as a powerful inhibitor of active cell death. Since the transection of the optic nerve in adult mammalians starts a massive process of degeneration in retinal ganglion cells, we investigated whether the overexpression of bcl-2 in adult transgenic mice can protect the axotomized ganglion cells. We performed intracranial optic nerve transection on both wild type and transgenic adult mice, and we tested cell survival 2 or 3.5 months after axotomy. The percentage of surviving ganglion cells after optic nerve section was computed by combining the counts of the optic nerve fibres in intact nerves with the cell density measures of the ganglion cell layer of axotomized retinae. From these data we found that in transgenic mice approximately 65% of ganglion cells survived 3.5 months after axotomy. In contrast, 2 months after surgery, < 10% of ganglion cells were left in wild type retinae. We have also examined the morphology and fine structure of the proximal stump of the sectioned optic nerves by light and electron microscopy. In the transgenic mice a very large number of axons survived after surgery and they still exhibited fairly normal morphology and ultrastructure. On the other hand the wild type transected nerves had only a few visible axons that displayed clear signs of degeneration. We conclude that the overexpression of Bcl-2 protein in central neurons is a very effective strategy to ensure long-term survival in axotomized cells.

Protection of retinal ganglion cells from natural and axotomy-induced cell death in neonatal transgenic mice overexpressing bcl-2

Approximately half of the retinal ganglion cells (RGCs) present in the rodent retina at birth normally die during early development. Overexpression of the photo-oncogene bcl-2 recently has been shown to rescue some neuronal populations from natural cell death and from degeneration induced by axotomy of nerves within the peripheral nervous system. Here we study in vivo the role of the overexpression of bcl-2 in the natural cell death of RGCs and in the degenerative process induced in these cells by transection of the optic nerve. We find that in newborn bcl-2 transgenic mice, the number of RGCs undergoing natural cell death is considerably lower than in wild-type pups. Consistently, a vast majority (90%) of the ganglion cells found in the retina of neonatal transgenics are maintained in adulthood, whereas only 40% survive in wild-type mice. After transection of the optic nerve, the number of degenerating ganglion cells, determined by counting pyknotic nuclei or nuclei with fragmented DNA, is substantially reduced in transgenic mice. In wild-type animals, almost 50% of ganglion cells degenerate in the 24 hr after the lesion, whereas almost the entire ganglion cell population survives axotomy in transgenic mice. Therefore, overexpression of bcl-2 is effective in preventing degeneration of this neuronal population, raising the possibility that ganglion cells are dependent on the endogenous expression of bcl-2 for survival. The remarkable rescue capacity of bcl-2 overexpression in these neurons makes it an interesting model for studying natural cell death and responses to injury in the CNS.

The distribution of brain-derived neurotrophic factor and its receptor trkB in parvalbumin-containing neurons of the rat visual cortex

We analysed the distribution of brain-derived neurotrophic factor (BNDNF) and its receptor trkB in the adult rat visual cortex, paying particular attention to a GABAergic neuronal subpopulation - the parvalbumin-positive cells. We found expression of trkB in the cell body and apical dendrite of pyramidal neurons and in the cell body of non-pyramidal neurons. Double labelling experiments revealed extensive colocalization of parvalbumin and trkB immunoreactivity in non-pyramidal neurons. Interestingly, the trkB-positive pyramidal neurons appeared surrounded by parvalbumin-labelled boutons. The use of double immunohistochemistry and in situ hybridization histochemistry showed that parvalbumin-positive neurons express trkB mRNA. BDNF mRNA was found in several cells. Coexpression of BDNF mRNA and parvalbumin immunoreactivity was extremely rare. These data strongly suggest that BDNF synthesized by cortical neurons acts as a postsynaptically derived factor for parvalbumin-positive neurons in the adult rat visual cortex.

The action of neurotrophins in the development and plasticity of the visual cortex

Nerve growth factor (NGF) and the other members of the NGF gene family have been extensively characterized as neurotrophic factors. Recently a modulatory action of these neurotrophic factors on synapse efficacy has emerged. The developing visual system has provided a convenient model to test the role of neurotrophins on neural plasticity in vivo.

Minimally differentiated acute myeloid leukemia (AML-M0): a distinct clinico-biologic entity with poor prognosis

FAB proposals for the diagnosis of AML-M0 represent the formal recognition of a distinct entity which has been described over the past few years by several authors and called minimally differentiated acute myeloid leukemia. By definition, AML-M0 includes acute leukemias which do not fit morphological and cytochemical criteria for the diagnosis of AML, and for which myeloid lineage assignment can be made by immunological assay showing positivity for MPO, CD13, and CD33 and negativity for lymphoid markers. Involvement of an early myeloid progenitor in the leukemic process is a possible theory hypothesized to explain the existence of such a form. Validity of this assumption has been based on the observation that AML-M0 frequently bears "stem cell" markers such as CD34, HLA-DR, Tdt, CD7, and promiscuous IgH/TCR gene rearrangements, which are thought to occur in uncommitted cells. Finally, AML-M0 very frequently carries cytogenetic abnormalities common to MDS or secondary AML, such as -5/5q- or -7/7q- deletions and or complex karyotype. In our experience, AML-M0 is also very often associated with the MDR phenotype, which in turn has been found strictly linked to "stem cell" features, especially in MDS. These biological aspects, altogether, translate into a very unfavorable prognosis, confirming even from a clinical point of view that AML-M0 is a distinct entity. In conclusion, "stem cell" markers, MDR phenotype, complex chromosome lesions, frequent occurrence in elderly patients, and intrinsic chemoresistance characterize AML-M0 and indicate the need for tailored treatments, possibly involving the use of MDR modulators and/or differentiating agents.

Plasticity in the developing visual system

A long series of studies beginning with the pioneering experiments of Wiesel and Hubel [1] has shown that correct visual experience is crucial for the development of the visual system. Recent results suggest that neurotrophic factors of the nerve growth factor family might have a relevant role in mediating the effects of visual experience on the developing visual system.

TrkA, TrkB and p75 mRNA expression is developmentally regulated in the rat retina

We examined the cellular distribution of mRNAs coding for the neurotrophin receptors TrkA, TrkB and p75 in the rat retina during early postnatal development. At P0 (postnatal day 0), mRNAs coding for each of the three receptors were detected in the ganglion cell layer (GCL) and in the inner plexiform layer (IPL), the latter structure essentially containing retinal ganglion cell processes at this developmental stage. At P5, the innermost part of the inner nuclear layer (INL) also expressed TrkA, TrkB and p75 mRNAs. Finally, the GCL, IPL and the whole INL of P10 retinae were labeled by the three probes. The developmentally regulated expression of these receptors underlies a possible role for neurotrophins in the differentiation and survival of retinal cells.

[A rare cause of neurologic bladder: arteriovenous dural fistula with venous epidural drainage]

Spinal dural arteriovenous fistula (DAVF) with epidural drainage is infrequent: 22 cases of the 194 reported DAVF. In the case reviewed, DAVF is associated with a complete urinary retention and its somatic neurologic features are moderate. Such spinal arteriovenous fistula clinical picture is rare and occurs in only 4 to 5% cases. Urological diagnosis approach is interesting because of a patient presenting with a benign prostatic hypertrophy.

Monocular deprivation decreases the expression of messenger RNA for brain-derived neurotrophic factor in the rat visual cortex

We found that deprivation of pattern vision in one eye, that leaves luminance detection performance unaffected, is sufficient to reduce brain-derived neurotrophic factor (but not trkB) messenger RNA in the visual cortex of young and adult rats. Monocular deprivation by means of eyelids' suture was performed during or after the critical period and the cortical amount of brain-derived neurotrophic factor messenger RNA was analysed by in situ hybridization and RNAase protection after 15-30 days of deprivation. A reduction of brain-derived neurotrophic factor messenger RNA was observed in the visual cortex contralateral to the deprived eye in rats monocularly deprived during the critical period. The same reduction was also found in rats monocularly deprived after the end of the critical period, when anatomical or physiological signs of monocular deprivation are absent. The pharmacological blockade of retinal activity equally affected the expression of brain-derived neurotrophic factor messenger RNA in young and adults. Quantitative RNAase protection assays revealed that the cortical level of brain-derived neurotrophic factor messenger RNA was reduced to the same extent when intraocular injections of tetrodotoxin were performed within or after the critical period. A developmental study of brain-derived neurotrophic factor messenger RNA expression in rat visual cortex showed a marked increase around the time of natural eye-opening followed by a plateau from postnatal day 20 until adult age. Messenger RNA for the kinasic domain of brain-derived neurotrophic factor receptor (trkB) was found in the dorsal lateral geniculate nucleus and the visual cortex during development and in adults. Our results suggest that the reduction of brain-derived neurotrophic factor messenger RNA induced by monocular deprivation is related to the absence of pattern vision rather than to the competitive interactions that underlie the effects of monocular deprivation during the critical period.

Cytogenetic analysis is non-informative for assessing the remission rate in chronic myeloid leukemia (CML) patients on interferon-alpha (IFN-alpha) therapy

Cytogenetic analysis is considered pivotal for assessing the remission rate in CML patients on IFN therapy. On the basis of general agreement, at least 25 metaphases should be analyzed in each case. The main limitations to this approach are: 1) the small number of analyzable metaphases generally found in cytogenetic preparations from IFN-alpha-treated patients; and 2) the inability of this technique for scoring interphase cells. We compared the results of cytogenetic analysis and double-color FISH detection of bcr/abl genes fusion in 13 CML patients on IFN-alpha therapy (marrow sampling for cytogenetic and FISH analysis was carried out after 12 months in all patients and repeated after 18 months of IFN therapy in patients 4, 6, and 8). In five specimens, 20 to 25 cells were evaluable for cytogenetic examination, in another five no analyzable metaphases were scored, and in the remaining six samples two to 14 cells could be analyzed. With FISH detection at least 100 cells were easily scored in each specimen (mean number, 175). Comparing the results carried out with the two methods in different samples it emerged that cytogenetic analysis led to improper conclusions as regards the rate of Ph positivity, even in those patients where 20-25 metaphases were analyzed. Although many more cases have to be studied to establish the role of FISH analysis in Ph-positive patients, we are of the opinion that cytogenetic analysis is unfit for easily and accurately assessing the actual quality of remission in IFN-treated subjects.

A developmentally regulated nerve growth factor-induced gene, VGF, is expressed in geniculocortical afferents during synaptogenesis

The expression of the nerve growth factor-inducible gene VGF has been examined by in situ hybridization. Western blot and immunohistochemical studies in the developing and adult rat central nervous system, with particular emphasis on the visual system. Both the messenger RNA and the protein are particularly abundant in the developing dorsal lateral geniculate nucleus, appearing, respectively, at embryonal day 16 and 18. After its onset at E16, VGF messenger RNA expression increases progressively in the dorsal lateral geniculate nucleus and remains high during the first two post-natal weeks; afterwards, it gradually decreases and, at the offset of the plasticity period, it reaches very low levels maintained in adulthood. A similar time course has been observed for VGF protein in the dorsal lateral geniculate nucleus area, by semi-quantitative Western blots. In addition to the presence of the protein in the geniculate neurons, a strong, transient immunoreactivity has been found at the embryonic cortical subplate at E18, reflecting the presence of the antigen in axonal terminals originating from thalamic neurons. Interestingly, we found that the blockade of afferent electrical activity by intraocular injection of tetrodotoxin strongly reduces the level of VGF messenger RNA in the dorsal lateral geniculate nucleus. Although the function of the VGF protein is not known, it had been previously proposed that VGF could be a precursor for neuropeptide/s. The spatiotemporal expression of VGF, together with the observation of a regulation by electrical activity, suggest that this protein may be relevant in the process of synaptogenesis and/or synaptic stabilization in the developing geniculocortical connections.

Nerve growth factor preserves behavioral visual acuity in monocularly deprived kittens

Recent electrophysiological and anatomical experiments in rats and cats have shown that treatment with the neurotrophic factor-nerve growth factor (NGF)-prevents the effects of monocular deprivation (MD) at the level of visual cortex and lateral geniculate nucleus. We tested whether NGF treatment was effective in preventing MD effects on visual behavior of monocularly deprived kittens. Behavioral visual acuity was measured in kittens that had been monocularly deprived and treated intraventricularly with NGF for 2 weeks during the critical postnatal period. The detrimental effects of MD on behavioral visual acuity were found to be largely prevented by NGF treatment.

[Organizational analysis of hospital work: identification of constraint elements and hypothesis of their relationship with nurses' wellbeing]

The paper reports the results of a research project on hospital work in which the analysis of organized work situations in different contexts was made using a method based on a valid organizational theory, with the objective of an ergonomic study on the relationships between organized work and well-being. From the analysis of these different situations, via the application of the Method of Organizational Congruencies, the greatest individual level of danger for well-being was constantly observed in nurses, not only as regards the traditional risks of exposure to physical or biological agents, but also the psychophysical aspecific discomfort related, particularly, both to imposition and to uncertainty in the coordination and control of technical actions and in the coordination and control of individuals. The use of an instrument of organizational analysis and the contribution of specific disciplinary approaches (the theory on stress by H. Selye and the theory on communication by G. Bateson), satisfied the needs of suggesting and understanding the relationships between organization choices and well-being of nurses, with the aim of reducing the conditions of danger for well-being related to organization choices.