Treatment discontinuation following low-dose TKIs in 248 chronic myeloid leukemia patients: Updated results from a campus CML real-life study

TKIs long-term treatment in CML may lead to persistent adverse events (AEs) that can promote relevant morbidity and mortality. Consequently, TKIs dose reduction is often used to prevent AEs. However, data on its impact on successful treatment-free remission (TFR) are quite scarce. We conducted a retrospective study on the outcome of CML subjects who discontinued low-dose TKIs from 54 Italian hematology centers participating in the Campus CML network. Overall, 1.785 of 5.108 (35.0%) regularly followed CML patients were treated with low-dose TKIs, more frequently due to relevant comorbidities or AEs (1.288, 72.2%). TFR was attempted in 248 (13.9%) subjects, all but three while in deep molecular response (DMR). After a median follow-up of 24.9 months, 172 (69.4%) patients were still in TFR. TFR outcome was not influenced by gender, Sokal/ELTS risk scores, prior interferon, number and last type of TKI used prior to treatment cessation, DMR degree, reason for dose reduction or median TKIs duration. Conversely, TFR probability was significantly better in the absence of resistance to any prior TKI. In addition, patients with a longer DMR duration before TKI discontinuation (i.e., >6.8 years) and those with an e14a2 BCR::ABL1 transcript type showed a trend towards prolonged TFR. It should also be emphasized that only 30.6% of our cases suffered from molecular relapse, less than reported during full-dose TKI treatment. The use of low-dose TKIs does not appear to affect the likelihood of achieving a DMR and thus trying a treatment withdrawal, but might even promote the TFR rate.

Radio-induced esophageal motility disorders: An unrecognized diagnosis

PURPOSE

Esophageal motility disorders (EMD) after cervical or thoracic radiation therapy (RT) may represent a late impairment and appear under-diagnosed. This study aimed to assess the prevalence of EMD, diagnosed by high-resolution esophageal manometry (HREM) after cervical or thoracic RT. In this retrospective, single-centre study, all patients whom received cervical or thoracic RT and underwent HREM were eligible.

MATERIAL AND METHODS

Oncologic data were collected: site of neoplasia, type of cancer, oncologic management (surgery and chemotherapy). EMD were classified according to the new Chicago Classification.

RESULTS

Twenty patients (14 females), of mean age 62.33±11.14 years were included. Breast cancer was the most represented indication for RT (40%). Other cancers were lung tumor, head and neck tumors and Hogdkin's lymphoma. Dysphagia was the most frequent symptom justifying HREM (70%). Patients received a mean of 51±19.27 Gy, 70% of them (14/20) had radiation therapy concomitantly with chemotherapy. The delay between last radiation therapy session and HERM was 10.68±12.42 years. Twelve (60%) patients had an abnormal pattern at on HERM. Among them, 3 patients (15%) presented with a major motility disorder. The most frequent motility disorder was ineffective esophageal motility in 8 (40%) patients, 1 (5%) patient presented with type II achalasia.

CONCLUSION

EMD should be suspected in patients with a history of cervical or thoracic RT in case of upper GI symptoms with normal endoscopy. In these particular patients, a manometric diagnosis that can explain their symptoms is of particular importance to limit anxiety linked to unexplained troubles.

International benchmarking for health policy evaluation: the French National Health Strategy

Background

International benchmarking is a valued source of inspiration and learning for policy-makers to develop successful public health policies. Through comparison, the external coherence of one policy can be measured and its objectives redesigned. The French national health strategy (SNS) 2018-2022 comprises the French health policy framework focusing on four priority areas. The aim of this study was to conduct international benchmarking of current national health strategies to explore the external coherence of the SNS and evaluation methods.

Methods

A scoping review was conducted through available governmental and public health agencies' websites to survey national/federal health strategies in select high-income countries.

Strategical approaches, governance and policy duration were compared with four health priorities of the French SNS: prevention, social/territorial inequalities, quality of care, innovation. A descriptive analysis of these strategies' evaluation methods, including relevant indicators, was executed.

Results

Out of 18 countries selected, 11 have a current strategy akin to the four priorities of the French SNS, with a timeline stipulated to implement the policy. The strategies of Australia and Switzerland, out of nine countries with strategies covering these areas, bear the closest resemblance to the French SNS. Evaluation methods varied largely across countries.

Conclusions

The majority of countries contain a health strategy with a longer duration compared to the French SNS, irrespective of governance. Similar priorities were found for countries with a national health strategy, with other countries developing at least prevention plans. Most countries provided only partial evaluation methods or overall health target indicators, to be taken into account for the development of the French SNS evaluation plan

Key messages

International benchmarking is essential to identify best practices in health policy design. As a result, future French health strategies may benefit from a longer duration of implementation. If great efforts were put in place in France to build a strategy evaluation plan, other countries focused mostly on implementation reports or monitoring national health targets through indicators.

Immunohistochemical localization of renin-containing cells in two elasmobranch species

Renin immunoreactivity was localized at the light and electron microscopic level in two elasmobranch fish species, the Atlantic stingray, Dasyatis sabina, and river ray, Potamotrygon humerosa. At the light microscopic level, the peroxidase-anti-peroxidase method showed a positive immunoreactivity in modified smooth muscle cells in kidney afferent arterioles as well as in arterioles of several organs: rectal gland, inter-renal gland, conus arteriosus, and gill. Electron microscopic renin-positive immunogold localization was confined to the contents of membrane bound granules in the modified smooth muscle cells of these arterioles. The presence of renin-containing granules in the modified smooth muscle, "granular cells," of the renal glomerular afferent arteriole of these two stingray species adds support to earlier studies which showed the structural components of a complete juxtaglomerular apparatus and some of the biochemical and molecular components of a renin-angiotensin system (RAS) as found in teleost fish, reptiles, birds, and mammals. A notable result, however, was the renin-positive immunoreaction in the arteriolar wall of all other organs studied here. The presence of this "diffuse renin system" in the connective tissue of various organs suggests that in these two stingray species in addition to local organ-specific functions, the RAS may act as a systemic mechanism to regulate blood pressure and blood flow in the body.

Cell junctions of the glomerular epithelium in a very early vertebrate (Myxine glutinosa)

The glomerular epithelial cells of the Atlantic hagfish (Myxine glutinosa) lack a slit diaphragm which is replaced by filaments. The epithelial cells show numerous occluding junctions (maculae and fasciae occludentes), septate desmosome-like junctions and desmosomes. The present findings are compared with available data on developing and mature glomerular epithelial cells of mammals.

Meta-analysis of mould and dampness exposure on asthma and allergy in eight European birth cohorts: an ENRIECO initiative

BACKGROUND

Several cross-sectional studies during the past 10 years have observed an increased risk of allergic outcomes for children living in damp or mouldy environments.

OBJECTIVE

The objective of this study was to investigate whether reported mould or dampness exposure in early life is associated with the development of allergic disorders in children from eight European birth cohorts.

METHODS

We analysed data from 31 742 children from eight ongoing European birth cohorts. Exposure to mould and allergic health outcomes were assessed by parental questionnaires at different time points. Meta-analyses with fixed- and random-effect models were applied. The number of the studies included in each analysis varied based on the outcome data available for each cohort.

RESULTS

Exposure to visible mould and/or dampness during first 2 years of life was associated with an increased risk of developing asthma: there was a significant association with early asthma symptoms in meta-analyses of four cohorts [0-2 years: adjusted odds ratios (aOR), 1.39 (95% CI, 1.05-1.84)] and with asthma later in childhood in six cohorts [6-8 years: aOR, 1.09 (95% CI, 0.90-1.32) and 3-10 years: aOR, 1.10 (95% CI, 0.90-1.34)]. A statistically significant association was observed in six cohorts with symptoms of allergic rhinitis at school age [6-8 years: aOR, 1.12 (1.02-1.23)] and at any time point between 3 and 10 years [aOR, 1.18 (1.09-1.28)].

CONCLUSION

These findings suggest that a mouldy home environment in early life is associated with an increased risk of asthma particularly in young children and allergic rhinitis symptoms in school-age children.

Partial deletions of long arm of chromosome 6: biologic and clinical implications in adult acute lymphoblastic leukemia

Within 285 adult acute lymphoblastic leukemias (ALL) included in the multicenter GIMEMA 0496 trial and prospectively studied by conventional cytogenetics, 18 cases (6%) with long arm deletion of chromosome 6 (6q) were identified. These cases were divided into: (i) del(6q) only (n = 6); (ii) del(6q) plus other numerical and/or structural abnormalities (n = 8); (iii) del(6q) and other 'specific' translocations (n = 4). The biologic and clinical features of the patients carrying this anomaly, as well as their outcome, were compared with those of 267 patients without del(6q). A T cell phenotype was more frequently associated with del(6q) cases in general (P = 0.001) and particularly with cases presenting del(6q) as the isolated abnormality (P = 0.0027). No significant difference with respect to multidrug resistance (MDR)/P glycoprotein expression was observed between the two groups of patients (21% vs 28% of MDR-positive cases, respectively). A BCR-ABL fusion transcript was less frequently detected in cases with del(6q) (11%) compared with those without the anomaly (29%). p15 and p16 deletions were identified by Southern blot analysis in 21% of cases with del(6q) and in 26% of cases without del(6q). In this latter group, a T cell phenotype was less frequently associated with p15 and/or p16 deletion than in the group carrying del(6q) (36% vs 100% of cases, P = 0.011). Overall, patients with ALL and del(6q) had a high complete remission (CR) rate (83%); however, they had a lower 18 month event-free survival (31% vs 41%) and a higher relapse rate (70% vs 37%, P = 0.02) compared with patients without del(6q). To date, this is the largest series of adult ALL cases reported with del(6q) homogeneously treated, which have also been prospectively studied for MDR expression and for the detection of known fusion genes. This anomaly, as an isolated change, identifies a subset of cases with hyperleukocytosis (median WBC count 52 x 10(9)/l) and a strict correlation with a T cell phenotype. Overall, del(6q) seems to be associated with an unfavorable clinical outcome, although this finding will need to be confirmed by extended FISH analysis.

Apoptosis induction in vivo and fate of apoptotic material in the colon of the guinea pig

Short-chain fatty acids (SCFA) in particular butyrate are regarded as an energy source acting in beneficial, protective manner on the colonic mucosa. Previous investigations showed that the colonic mucosa bathed in Ussing chamber with a solution lacking butyrate induced massive apoptosis of epithelial cells. The apoptotic material (bodies and cells) was shed at the mucosa surface. In the present study we aimed to investigate the effects caused in vivo on the colonic mucosa by the absence of butyrate. For this purpose the colon of guinea pigs was perfused in situ with solutions either containing or lacking butyrate. The results show that within 2h of perfusion without butyrate a large amount of epithelial cells underwent apoptosis as in the in vitro experiments. However, apoptotic material instead to be extruded at the epithelial surface accumulates into the intercellular spaces from which it becomes removed by an unusual high number of macrophages. These, engorged with phagocytozed material, lie assembled in a layer below the epithelium. Similar alterations have not been observed after perfusion in the presence of butyrate. The results suggest that this SCFA may protect the colonic mucosa in that it prevents apoptosis. The alterations occurring during 2h of its absence allow to assume that a protracted butyrate deprivation may lead to a breakdown of the integrity of the mucosa thus influencing differently the activity of the macrophages.

Epithelial cell turnover--extracellular matrix relationship in the small intestine of human adults

In the human small intestine, proliferation, migration, differentiation and death of epithelial cells take place in separated compartments along the crypt-villus axis. It has been shown in different cell systems that these basic biological activities are influenced by extracellular matrix proteins. To investigate possible relationships in the epithelium of the human adult small intestine we examined immunohistochemically the distribution of type IV collagen, laminin, fibronectin and tenascin, and compared the sites of their expression with the various cell activities. Epithelial cell proliferation and cell death have been detected by an antibody against Ki-67 and the TUNEL-assay, respectively. The results show that Ki-67 staining is restricted to the crypts and TUNEL-positive cells are only present in the upper villus region. Type IV collagen is uniformly present in the epithelial basement membrane along the crypt-villus axis providing a scaffold for other components of the extracellular matrix. Laminin appears to be associated with epithelial cell differentiation, since it is strongly expressed in the villus basement membrane but only weakly underneath the crypt epithelium. Although fibronectin displays a staining pattern similar to that of laminin, it might rather be responsible for cell adhesion. Strong indications have been found that tenascin could be related to epithelial cell death since it was particularly expressed at the villus tip, where the cells undergo apoptosis.

Characterization of two novel cell lines, DERL-2 (CD56+/CD3+/Tcry5+) and DERL-7 (CD56+/CD3-/TCRgammadelta-), derived from a single patient with CD56+ non-Hodgkin's lymphoma

Two novel IL2-dependent cell lines, DERL-2 and DERL-7, were established from a patient with hepatosplenic gammadelta T cell lymphoma. This patient presented, at diagnosis, two discrete populations of CD56+ cells, one TCRgammadelta+, the second lacking T cell-restricted antigens. The cell lines derived displayed features corresponding to the two cellular components of the disease: DERL-2 was CD56+/CD3+/TcRgammadelta+ while DERL-7 was CD56+/CD3-/TcRgammadelta-. Along with CD56, the two cell lines shared the expression of CD7, CD2, CD158b and CD117. Karyotype analysis showed that both cell lines were near-diploid, with iso-7q and loss of one chromosome 10. In addition, DERL-2 showed 5q+ in all metaphases analyzed, while DERL-7 revealed loss of one chromosome 4. Genotypically, both cell lines shared the same STR pattern at nine loci and demonstrated an identical rearranged pattern of the T cell receptor genes beta, gamma and delta, with respect to the original tumor cells. These data indicated that both cell lines and the original neoplastic populations were T cell-derived and arose from a common ancestor. Among a large panel of cytokines tested, only SCF was able to substitute IL2 in supporting cell proliferation. Moreover, SCF and IL2 acted synergistically, dramatically enhancing cell growth. These cell lines may represent a model to further analyze the overlap area between T and NK cell malignancies, and may provide new information about the synergistic action of IL2 and SCF on normal and neoplastic T/NK cells.

Where's the leadership for quality measurement?

With performance measurement in gridlock, purchasers look to disease intervention to improve medical care. Consumers, meanwhile, are left with member surveys and sketchy info on providers.

Re-evaluation of epoxy resin sections for light and electron microscopic immunostaining

Epoxy resins provide optimal tissue morphology at both the light and the electron microscopic level and therefore enable correlative studies on semithin and thin sections from the same tissue block. Here we report on an approach to retain these advantages for immunolabeling studies by adapting and combining well-known techniques, i.e., surface etching with sodium ethoxide and heat-mediated antigen retrieval. We propose a simple procedure for immunostaining semithin and thin epoxy resin sections. To check its applicability, well characterized, commercially available antibodies (against E-cadherin, alpha-catenin, and beta-catenin) were used on sections of human small intestine. By light microscopy, the immunostaining efficiency was compared on cryo-, paraffin, and epoxy semithin sections processed in parallel. The most detailed results were obtained on semithin sections, where the labeling precisely delineated the lateral plasma membrane of the enterocytes. At the electron microscopic level the procedure did not damage the structures and allowed an efficient, reproducible immunogold labeling extending homogeneously over exceptionally wide tissue areas. The three antibodies specifically labeled the zonula adherens of the junctional complex between epithelial cells and, in agreement with light microscopic observations, the lateral plasma membrane.

In the mammalian eye type VI collagen tetramers form three morphologically different aggregates

The organization of the aggregates occurring in the stroma: (1) of the murine and human cornea after incubation in an ATP acidic solution; (2) of surgically excised epiretinal membranes (ERM); and (3) of the trabecular meshwork of monkey eyes was investigated morphologically and immunocytochemically on thin section electron microscopy. Morphology. The aggregates in the cornea appeared as cross-banded fibrils. The bands were uniformly electron dense (single banded form); they were separated from each other by interbands consisting of a bundle of filaments emerging in cross section as small areas of randomly assembled dot-like structures. In the ERM, most of the aggregates stood out as heteromorphic cross-banded bodies showing dense bands with electron denser borders (double banded form) and interbands composed of longitudinally oriented, parallel sheets or laminae of amorphous material enclosing thin, similarly oriented filaments. These extended, thinner and double in number (since interlacing with similar components of the opposite sheet), into the pale central zone of the dense band. The aggregates of the trabecular meshwork were heteromorphic, had uniformly dense bands (single banded form as in the cornea), but their interbands displayed longitudinal sheets (as the ERM aggregates). Immunocytochemistry revealed type VI collagen in the three eye aggregates with gold particles preferentially localized at the interbands. The specificity of the antibodies used was tested by Western blot analysis of type VI collagen samples extracted from human placenta and on homogenates of human cornea. In conclusion, the results indicate that the tetramers of type VI collagen may aggregate differently into structures with distinct supramolecular arrangements. These are illustrated in schematic drawings.

Membrana limitans interna and epiretinal membrane lying on macular holes. Some morphological observations

The structure of the membrana limitans interna (MLI) in the region of the macula has been investigated by electron microscopy in (a) 2 enucleated human adult eyes and (b) 38 surgically removed samples associated with an epiretinal membrane (ERM). In the enucleated eye, the glia cells were vitrad bordered either by the lamina rara or, directly, by the lamina densa. Both extended into a coarse network whereby the lamina densa, through repeated branches and anastomoses, delimited large meshes, the lamina rara formed their contents. High magnification revealed that both meshes and contents of this network were composed by a further, finer network. It is suggested that strips and small openings of the finer network are homologous to the cords and intercordal spaces, respectively, which have been indicated as the common, basic structures of most of the basement membranes. The MLI excised with an ERM had the same structure. In some of the ERM associated with a macular hole, myofibroblasts prevailed among the cells. They showed indented nucleus, stress fibers abuting on the plasma membrane or in apparent continuity with bundles of extracellular filaments (microtendons), gap junctions. The cells lay on or were surrounded by a discontinuous basement membrane.

Rheological properties of mixtures of kappa-carrageenan from Hypnea musciformis and galactomannan from Cassia javanica

Mixed gels of kappa-carrageenan (kappa-car) from Hypnea musciformis and galactomannans (Gal) from Cassia javanica (CJ) and locust bean gum (LBG) were compared using dynamic viscoelastic measurements and compression tests. Mixed gels at 5 g/l of total polymer concentration in 0.1 M KCl showed a synergistic maximum in viscoelastic measurements for kappa-car/CJ and kappa-car/LBG at 2:1 and 4:1 ratios, respectively. The synergistic maximum obtained from compression tests carried out for mixed gels at 10 g/l of total polymer concentration in 0.25 M KCl was the same for both kappa-car/CJ and kappa-car/LBG gels. An enhancement in the storage modulus (G') and the loss modulus (G") was observed in the mechanical spectra for the mixtures in relation to kappa-car. The proportionally higher increase in G" compared with G', as indicated by the values of the loss tangent (tandelta), suggests that the Gal adhere non-specifically to the kappa-car network.

Intravenous versus oral initial load of propafenone for conversion of recent-onset atrial fibrillation in the emergency room: a randomized trial

BACKGROUND

Non-valvular paroxysmal atrial fibrillation is a common clinical condition associated with a high risk of thromboembolism and hemodynamic problems which increase with the duration of arrhythmia. Therefore, even if arrhythmia ceases spontaneously within 24 hours in about half of the patients, a higher early conversion rate is desirable. Propafenone either by intravenous or oral load has been shown effective in conversion to sinus rhythm.

METHODS

We consecutively randomized all emergency patients with non-valvular atrial fibrillation lasting no more than 48 hours to either intravenous or oral initial load of propafenone. They all received further oral doses if still on atrial fibrillation after the initial load. Exclusion criteria were: mean ventricular rate < 65 b/min, age > 75 years, recent acute myocardial infarction, overt heart failure, conduction defects, ventricular preexcitation, thyroid dysfunction, renal or hepatic insufficiency, pregnancy, current treatment with propafenone or other antiarrhythmic drugs, and intolerance to propafenone. Primary and secondary end-points were the conversion to sinus rhythm within 12 and 48 hours of randomization respectively.

RESULTS

Ninety-seven patients were randomized to intravenous (n = 49) or oral (n = 48) treatment. Overall, sinus rhythm restoration occurred in 83.3% of patients within 12 hours and in 98.9% at 24 hours. Recovery rate resulted significantly greater for intravenous treatment at 1 and 3 hours (p < 0.001 and p = 0.001, respectively). At 6, 12 and 24 hours no significant difference between the two groups was observed (p = 0.77, p = 0.81 and p = 0.99, respectively). No patient needed treatment suspension.

CONCLUSIONS

In patients with recent-onset non-valvular atrial fibrillation treated with propafenone within 48 hours, conversion to sinus rhythm occurred in more than 80% within 12 hours. Even if intravenous initial load appears to be slightly more rapid, the oral way is easier to administer and cheaper. The choice may depend on the specific organization of the single emergency room.

Coexistence of two distinct cell populations (CD56(+)TcRgammadelta(+) and CD56(+)TcRgammadelta(-)) in a case of aggressive CD56(+) lymphoma/leukemia

BACKGROUND AND OBJECTIVE

Large granular lymphocytes derive from two major lineages: one expressing the CD3 surface antigen (T-lymphocytes), and the other lacking this marker (NK-cells). Although developmental overlaps between natural killer cells and T-cells have been described, malignancies derived from these two cell types are considered as distinct lymphoid disorders.

DESIGN AND METHODS

We report the case of a 30-year old man affected by a lymphoma/leukemia syndrome presenting with hepatosplenic lymphoma which rapidly transformed into aggressive NK-leukemia. Extensive flow cytometry studies and molecular analysis were repeated during the course of the disease, and showed an unexpected changing pattern.

RESULTS

At diagnosis, flow cytometry analysis showed the co-existence of two cell populations, one CD56(+), CD3(+), TcRgd(+), and the other CD56(+), CD3(-) and TcRgd(-). Molecular analysis showed that the TcR genes had the same clonally rearranged pattern involving b, g and d genes in both populations. At disease relapse and during the terminal refractory phase, only CD3(-) cells were present.

INTERPRETATION AND CONCLUSIONS

This is an unusual case of CD56(+) aggressive lymphoma/leukemia characterized by the clonal expansion of two phenotypically different cell populations, variably balanced during the course of the disease. The presence of the same TcR genomic rearrangement suggests the origin from a common progenitor able to differentiate along both T- and NK-pathways.

Prolonged response to cyclosporin-A in hypoplastic refractory anemia and correlation with in vitro studies

BACKGROUND AND OBJECTIVE

Lymphocyte abnormalities in myelodysplastic syndromes (MDS) have been widely described, but the role of the immune system in the pathogenesis of these clonal disorders remains controversial. An active role of lymphocytes in suppressing normal hematopoiesis may be implicated in MDS with hypoplastic marrow. We have studied in vitro and in vivo activity of cyclosporin-A (CSA) on hematopoiesis in patients affected by hypoplastic MDS without blast excess.

DESIGN AND METHODS

Nine consecutive patients with hypoplastic refractory anemia (RA), followed up in our out-patient unit, were treated with CSA at daily doses of 1-3 mg/kg for at least three months. Low dose steroids or danazol were transiently added in 7/9 patients. Differences between pre- and post-treatment parameters were studied by the Student's t-test. In vitro effect of CSA on circulating hematopoietic progenitors was studied by the methylcellulose colony assay.

RESULTS

Before treatment, fewer circulating hematopoietic progenitors were found in all patients as compared to normal subjects. The number of CD34+ cells was about halved, while circulating erythroid and myeloid colony-forming cells (CFC) were reduced to one-fifth. After a mean period of 22 months of CSA treatment (median: 14.5 months), hemoglobin was significantly and persistently increased in two patients, platelets in one, platelets and hemoglobin in two. Two patients showed transient responses, one patient did not tolerate the treatment and one patient is close to a significant response. At in vitro CSA concentrations similar to those achieved in vivo after oral administration the drug significantly increased cell colony growth in hypoplastic RA. This test correctly predicted a positive clinical response to CSA in 3/5 cases and treatment failure in 4/4 cases.

INTERPRETATION AND CONCLUSIONS

About one half of hypoplastic RA patients benefited from CSA treatment. A larger study could verify whether in vitro culture of hematopoietic progenitors in the presence of CSA can predict the clinical response and whether this treatment could prolong patients' survival.

Solution properties of the galactomannans extracted from the seeds of Caesalpinia pulcherrima and Cassia javanica: comparison with locust bean gum

The galactomannans from the seeds of Caesalpinia pulcherrima and Cassia javanica were extracted from the milled seeds in water at room temperature. Both products, as well as a commercial sample of locust bean gum (LBG), were purified by precipitation in isopropyl alcohol. The intrinsic viscosity determined for LBG, [eta] = 15.2 dl/g, was slightly higher than those for the other two galactomannans. The dependence of the specific viscosity at zero shear rate on the coil overlap parameter, C[eta], revealed a similar behaviour for the three galactomannans. A master curve was obtained with a critical concentration, C*, at C*[eta] = 3.3. The slope of the curve in the concentrated regime is higher than the values in the range of 3.9-6.6, obtained for the generalized behaviour of several random coil polysaccharides. Dynamic experiments showed that, at the concentrations studied, the behaviour of the galactomannans was typical of systems with predominant entanglement networks in the region between the terminal and plateau zones of frequency response. The correlation between dynamic and steady shear properties (Cox Merz rule) was satisfactory for the three galactomannans.

BCR/ABL mRNA and the P210(BCR/ABL) protein are downmodulated by interferon-alpha in chronic myeloid leukemia patients

The BCR/ABL hybrid gene plays a central role in the pathogenesis of the chronic phase of chronic myeloid leukemia (CML). We used a very sensitive quantitative reverse transcriptase-polymerase chain reaction to investigate the levels of hybrid BCR/ABL mRNA in bone marrow cells of 20 patients with Philadelphia positive (Ph(+)) CML treated with interferon-alpha (IFN-alpha) as a single agent. Bone marrow samples were collected at diagnosis and at hematologic remission induced by IFN-alpha, or by hydroxyurea in case of resistance to IFN-alpha. The mean levels of BCR/ABL transcripts in bone marrow mononuclear cells of patients who showed a complete hematologic response to IFN-alpha were significantly reduced with respect to those at diagnosis (48 x 10(3) v 168 x 10(3); P <.001), whereas no difference was detected between the values at diagnosis and at hematologic remission in patients resistant to IFN-alpha. In cell culture experiments, IFN-alpha priming significantly reduced the levels of BCR/ABL hybrid transcripts in a dose-dependent manner in Ph+ bone marrow precursors obtained at diagnosis from patients who subsequently responded to IFN-alpha treatment (P < .005). No downmodulation was observed in bone marrow precursors from patients who subsequently proved to be IFN-resistant. These results indicate that downmodulation of BCR/ABL gene expression could be one of the mechanisms involved in the response of CML patients to IFN-alpha treatment.

AlphaIFN-induced hematologic and cytogenetic remission in chronic eosinophilic leukemia with t(1;5)

Chronic eosinophilic leukemia (CEL) is a myeloproliferative disease characterized by excessive eosinophilic proliferation with clonal cytogenetic abnormalities. The most frequent cytogenetic abnormality is a break in the q 31-35 region of chromosome 5, where genes encoding for IL-3, IL-5 and GM-CSF (all cytokines involved in eosinophilopoiesis) are located. We report the case of a patient with CEL with t(1;5) (q23;q31), who obtained complete hematologic and major cytogenetic response after two years of alpha-interferon (alpha-IFN) therapy. Two other cases of complete response to alpha-IFN are reported in the literature. A trial with alpha-IFN could be considered as front line treatment in this rare disease.

Long-lasting decrease of marrow and circulating long-term culture initiating cells after allogeneic bone marrow transplant

We investigated bone marrow (BM) and circulating (PB) hematopoietic progenitor cells in 37 normal donors and in 25 patients 1 to 8 years after successful allogeneic bone marrow transplant. At the time of testing, transplanted patients had normal blood counts and bone marrow cellularity. By flow cytometry, BM CD34+ cells were found to be three- to four-fold decreased in transplanted patients compared to normal donors, while the number of PB CD34+ cells was the same as in normal donors. Using a methylcellulose colony assay, primary BM colony-forming cells (CFU-GM) were decreased 2.1-fold, whereas PB CFU-GM were only marginally decreased. In a long-term culture initiating cell (LTC-IC) assay, an eight-fold decrease of early progenitor cells was observed in the marrow of transplanted patients compared to normal donors, and a five-fold decrease was documented in peripheral blood. We found that the BM LTC-IC cell number correlated with concurrently determined BM CD34+ cells and committed progenitor cell number (measured as CFU-GM) and with PB LTC-IC number, but not with PB CFU-GM and CD34+ cells. We conclude that marrow and circulating early stem cell compartments, as measured by the LTC-IC assay, are greatly and permanently depressed following bone marrow transplant. The correlation between BM and PB LTC-IC indicates that the enumeration of circulating LTC-IC can be used as a measure of the stem cell compartment in the bone marrow after transplant. It seems that the deficiency of the most immature progenitor cells persists forever after successful bone marrow transplant; this means that a complete hematopoietic reconstitution can be sustained by a reduced stem cell pool.

Acute promyelocytic leukemia after treatment for non-Hodgkin's lymphoma with drugs targeting topoisomerase II

We report a patient who developed acute promyelocytic leukemia (APL) concomitantly with a second relapse of non-Hodgkin's lymphoma (NHL), intermediate grade, WF type E. At diagnosis and at first NHL relapse, the patient had received the same chemotherapy regimen, which included drugs targeting DNA topoisomerase II, i.e., etoposide (total dose 5,760 mg) and idarubicin (total dose 180 mg). Thirty-eight months after initial treatment, the patient showed pancytopenia associated with lymphoma recurrence. Bone marrow examination revealed the presence of atypical promyelocytes with Auer rods; cytogenetics showed t(15;17), and molecular analysis detected promyelocytic leukemia-retinoic acid receptor alpha rearrangement. APL reached complete remission after all trans retinoic acid therapy, whereas NHL did not respond to further chemotherapy. In the literature, five other patients developed APL after treatment for lymphoma, from a total of 59 patients developing sAPL after treatment for any type of neoplasia.

CD34+-enriched donor lymphocyte infusions in a case of pure red cell aplasia and late graft failure after major ABO-incompatible bone marrow transplantation

A variety of immunohematological complications may occur after ABO-incompatible BMT. We report a CML patient (blood group O) who received a BMT from an HLA-identical sibling (blood group AB). The transplant was followed by normal myeloid and megakaryocytic engraftment, but erythroblastopenia persisted for more than 200 days after BMT. By bone marrow culture studies, a complement-dependent serum inhibitor of hemopoiesis was detected, suggesting immunological inhibition of erythropoiesis. The patient was resistant to a number of treatments such as intravenous gamma-globulins, prednisolone and high-dose erythropoietin. Full engraftment with normal blood counts and marrow cellularity was achieved after two dose-escalating CD34+-enriched donor lymphocyte infusions (DLI). This experience suggests that CD34+-enriched DLI may be an effective treatment for patients with delayed engraftment or late graft failure due to major ABO-incompatibility.

Fas-mediated modulation of Bcr/Abl in chronic myelogenous leukemia results in differential effects on apoptosis

Fas-R is expressed constitutively in CD34(+) cells of patients with chronic myelogenous leukemia (CML); Fas-R triggering results in decreased proliferation rate due to apoptosis of clonogenic cells. We have already shown that alpha-interferon (IFN-alpha) enhances Fas-R expression on CML progenitor cells, thus increasing their sensitivity to Fas-R agonists. Although it appears that IFN-alpha can prime CML cells for the effects of Fas, the response to IFN-alpha in vivo is not a constant feature in CML patients. We studied the mechanisms of Fas-mediated apoptosis in 11 patients suffering from CML in chronic phase and tried to see whether there was a correlation between in vitro inducibility of apoptosis in CD34(+) CML cells after Fas-R triggering and the clinical response to IFN-alpha. After priming with IFN-alpha, Fas triggering resulted in in vitro suppression of hematopoietic cell growth in seven of eight patients who had optimal hematologic response to IFN-alpha; in the same conditions, no inhibitory response to Fas-R agonist was observed in cells from three of three patients who proved to be poor responders to IFN-alpha. In responders to IFN-alpha, Fas-R agonist induced dose-dependent apoptosis of CD34(+) cells; this effect was associated with a decrease in the bcr/abl protein level. In cells derived from patients with a poor response to IFN-alpha, the rate of apoptosis in culture remained unchanged in the presence of Fas-R agonist and no bcr/abl downmodulation was observed. Finally, we measured bcr/abl mRNA by quantitative reverse-transcriptase polymerase chain reaction (RT-PCR) and found that decreased bcr/abl protein after Fas triggering was not associated with decreased amounts of specific mRNA, a finding which is consistent with a posttranscriptional regulation of the bcr/abl protein expression. It appears that Fas-mediated downmodulation of p210 bcr/abl restores susceptibility to apoptosis of CML cells; in addition, in vitro studies on CML cells may predict response to IFN-alpha treatment.

Splenectomy and risk of blast transformation in myelofibrosis with myeloid metaplasia. Italian Cooperative Study Group on Myeloid with Myeloid Metaplasia

An unexpectedly high incidence of blast transformation after splenectomy has been reported in patients with myelofibrosis with myeloid metaplasia. However, whether this was associated with spleen removal after adjustment for risk factors was not determined. We conducted a multicenter historical cohort study of patients with myelofibrosis with myeloid metaplasia diagnosed from January 1970 through January 1994. A total of 549 patients (325 men and 224 women from 22 to 92 years of age; median age, 63 years) were included in the final data set. The Cox's proportional-hazards model was used to identify factors associated with blast transformation and death. To further adjust for factors related to spleen removal assignment, a propensity score for splenectomy was estimated using recursive-partitioning analysis. Blast transformation developed in 78 patients (14.2%). Patients who underwent splenectomy developed more blast transformations than those who were not splenectomized (23 of 87 [26.4%] v 55 of 462 [11.9%]; P < .001). The cumulative incidence of blast transformation 12 years after diagnosis was 27.0% in nonsplenectomized patients and 55.0% in splenectomized ones (P = . 01). The risk factors independently predictive of blast transformation included prior splenectomy (relative risk = 2.61), platelet count less than 100 x 10(9)/L at diagnosis (relative risk = 2.45), and the presence of blasts in peripheral blood at diagnosis (relative risk = 2.31). The relative risk of blast transformation in splenectomized patients increased from 2.2 at 48 months from diagnosis to 14.3 at 12 years. Patients with the same propensity score for splenectomy showed a higher risk for blast transformation on the basis of having undergone splenectomy (P = .02). In conclusion, the risk of blast transformation is significantly increased in subjects who underwent splenectomy and appears to be independent of factors related to spleen removal assignment.

Diverse morphology of biliary atresia in an animal model

BACKGROUND/AIMS

Extrahepatic biliary atresia can be simulated in Balb/c-mice which have been infected with rotavirus. Irreversible occlusion of the common bile duct is the result of an inflammatory process of the whole biliary tract. The observations in this animal model are similar to extrahepatic biliary atresia in newborn children. The present study describes the wide range of morphological findings in mice and compares the results with several classifications of extrahepatic biliary atresia in children.

METHODS

Newborn Balb/c-mice were infected intraperitoneally with rhesus rotavirus; the pathological morphology of the extrahepatic bile ducts in 73 mice is described and illustrated by scanning electron microscopy.

RESULTS

The extension and localisation of atresia varied from short to interrupted or long-segment atresia, with or without prestenotic dilatation. The gallbladder was small and atretic, or appeared hydropic due to atresia of the common bile duct. The wide range of pathomorphological findings is the final stage of an inflammatory process. The morphological changes of the extrahepatic bile ducts do not fit any pattern, and no classification is evident.

CONCLUSIONS

Most types of extrahepatic biliary atresia in children can be mimicked in this animal model. Comparing these observations with different classifications of extrahepatic biliary atresia in children, it must be asked if any classification of the disease is justified, having regard only to pathomorphological findings in the extrahepatic biliary tract.

Presence of brush cells in the mouse gallbladder

The brush cells (BC) are the second most frequent cellular component of the epithelium of the mouse gallbladder. They have a topographical distribution, being present in large numbers toward the neck and in the fundic regions of the organ and are scattered in the body. Serial section studies demonstrate that BC have a characteristic shape consisting of a narrow apical portion, bulky body and basal cytoplasmic projections. BC are located obliquely among the principal cells. Scanning electron microscopy demonstrates that the microvilli forming the prominent brush border, after which the cell was named, have a triangular arrangement. Due to their size and stiffness, the microvilli of BC have more similarity with stereocilia of sensory cells than with conventional microvilli. Furthermore freeze-fracture replicas demonstrate that, like stereocilia, the P face of the microvilli plasma membrane of BC is smoother than the E face but several intramembranous particles form small aggregates on the microvillus tip of both P and E faces. Numerous intramembranous particles are scattered on the lateral plasma membrane. An unusual, spatially organized cytoskeleton characterizes the apical cytoplasm of BC. The use of the appropriate fixative reveals that it consists of bundles of actin filaments originating from the axis of the apical microvilli and stretching continuously up to the supranuclear region of the cell. Microtubuli, also assembled in bundles, flank in alternating manner the actin filaments over their whole course. Due to the strong parallel arrangement of both cytoskeletal structures, the apical cytoplasm of the BC assumes a typical stiffness, observable in both thin sections and freeze-fracture replicas. A variable number of vesicles of different size are aligned between the bundles of actin filaments and microtubuli; their shape is highly influenced by the fixative used. Intraluminal injection of horseradish peroxidase demonstrates that these vesicles are not resorptive as they are not filled by the tracer. The BC possess a large number of lateral microvilli. These, whether single or in pairs, are rigid cytoplasmic protrusions that leave the lateral surface of the cell in all directions and penetrate deeply into the cytoplasm of the adjacent principal cells. The bundle of actin filaments emanating from each lateral microvillus extends at different angles into the cytoplasm. A conspicuous amount of bundles of 10 nm filaments is intertwined around the nucleus and extends toward the desmosomes of the lateral plasma membrane and into the basal cellular body. Arguments are considered in support of the view that interactions between the plasma membrane with its differentiations on the one hand and the cytoskeleton elements on the other hand, play a key role in the function of BC as a receptor (sensory) cell.

JURL-MK1 (c-kit(high)/CD30-/CD40-) and JURL-MK2 (c-kit(low)/CD30+/CD40+) cell lines: 'two-sided' model for investigating leukemic megakaryocytopoiesis

Two novel cell lines (JURL-MK1 and JURL-MK2) have been established from the peripheral blood of a patient in the blastic phase of chronic myelogenous leukemia. The cells grow in a single cell suspension with doubling times of 48 h (JURL-MK1) and 72 h (JURL-MK2). Cytogenetic analysis has shown that JURL-MK1 is hypodiploid whereas JURL-MK2 is near triploid and that both cell lines retain t(9;22). Moreover, JURL-MK1 and JURL-MK2 have a bcr/abl-fused gene with the same junction found in the patient's fresh cells, and both cell lines express the b3/a2 type of hybrid bcr/abl mRNA. The morphology and immunophenotype of these cell lines are reminiscent of megakaryoblasts. In both lines, a limited but consistent percentage of cells expresses gpIIbIIIa (CD41a), gpIIIa (CD61) and CD36, with no expression of gplb (CD42b), glycophorin A, hemoglobin and CD34. Both cell lines are clearly positive for CD33, CD43, CD45RO and CD63, while CD13, CD44, CD54, CD30 and CD40 are specific features of JURL-MK2. Among cytokine receptors, CD117/SCF-R is strongly displayed by a large fraction of JURL-MK1 cells but is hardly detectable on about 20% JURL-MK2 cells. Both cell lines are clearly positive for CD25/IL2R alpha, while a marked expression of CD116/GM-CSF-R and CDw123/IL3R alpha is restricted to JURL-MK2. Induction of cell differentiation in vitro has demonstrated that TPA is able to modulate the JURL-MK1 phenotype, causing an increased expression of platelet-associated antigens. The JURL-MK2 phenotype is easily modulated by both TPA and DMSO, which cause an increased expression of CD41a and CD117 accompanied by a decreased expression of CD30. Proliferation studies demonstrated that JURL-MK1 cell growth is enhanced by stem cell factor, while JURL-MK2 proliferation is unaffected by this cytokine. JURL-MK1 and JURL-MK2 are two novel cell lines with divergent biological features, representing a 'two-sided' model for investigating new aspects of megakaryocytopoiesis.

[Removal of the internal limiting membrane in macular holes. Clinical and morphological findings]

The recommended treatment for full-thickness macular holes is removal of the posterior hyaloid and sometimes the epiretinal membrane from the retina during vitrectomy in order to release the assumed intravitreous traction. We have employed a technique involving the additional removal of the membrana limitans interna (MLI) from the retina in the vicinity of the macular hole. We report on our clinical results and ultrastructural findings.

MATERIALS AND METHODS

Between December 1995 and July 1996, we performed vitrectomies on 39 eyes of 37 patients with full-thickness macular hole. After removal of the attached posterior hyaloid, a specially developed forceps was used to remove a circular area of the MLI approximately three to four disc diameters in size. At the conclusion of the operation, 20% C3F8 gas was injected and the patient instructed to stay in a prone position for 8 days.

RESULTS

Intraoperatively, "rhexis" of the MLI only rarely produced bleeding or recognizable retinal edema. Complete closure of the hole was observed postoperatively in 36 of the 39 eyes (92%). A visual improvement of at least two lines was achieved in 77% of eyes with successful closure. Pigment irregularities or edematous changes could not be detected either clinically or by fluorescein angiography in any of the 39 eyes. Electron microscopy was performed on 23 of the membranes. The salient feature was the MLI. Canals leading from the inner to the outer surface of the MLI contained Müller cell processes with clear signs of necrosis or degeneration. On the vitreous side, the MLI usually exhibited myofibroblasts.

CONCLUSIONS

The MLI was successfully removed in all 39 eyes with a full-thickness macular hole. This procedure led to very good anatomic and functional results. It remains for future studies to determine the pathogenic significance of the necrotic processes detected by electron microscopy in the MLI canals.