L-asparagine depletion and L-asparaginase activity in children with acute lymphoblastic leukemia receiving i.m. or i.v. Erwinia C. or E. coli L-asparaginase as first exposure

PURPOSE

The present study was aimed at investigating L-asparaginase (L-ASE) activity (in plasma) and L-asparagine (L-ASN) depletion (in plasma and CSF) in children with newly diagnosed acute lymphoblastic leukemia (ALL) exposed for the first time to different L-ASE products.

PATIENTS AND METHODS

During the induction treatment of the AIEOP ALL 95 study, 62 patients were treated with either Erwinase (n = 15), or E. coli medac (n = 47) L-ASE products, given either i.m. or i.v., at the standard dosage of 10,000 IU/m2, q 3 days x 8 (first exposure).

RESULTS

Plasma and CSF L-ASN trough levels were undetectable in all cases, including those with L-ASE trough activity < 50 mU/ml. L-ASE trough activity during the administration of medac was however significantly higher when compared with that of Erwinase.

CONCLUSIONS

L-ASN depletion after a first exposure to standard doses of Erwinase or medac is obtained in virtually all patients. No differences are seen between the I.M. or I.V. administration routes but the medac product is associated with a significantly higher enzyme activity in respect of Erwinase. L-ASN levels may be undetectable also in patients with L-ASE trough activity levels < 50 mU/ml, challenging the current opinion that an activity level of 100 mU/ml is needed to obtain L-ASN depletion.

Symptomatic and asymptomatic amoebiasis in two heterosexual couples

Four cases of amoebiasis are described: two symptomatic with intestinal and hepatic involvement and two asymptomatic, diagnosed in two, heterosexual, Italian couples. Infection was probably acquired first by the men, via an indirect faccal-oral route, and then transmitted to their partners in the same way. The two amoebic strains isolated, from the woman of one couple and the man of the other, were characterized by electrophoresis as zymodemes II alpha- and XIX of Entamoeba histolytica. These four cases emphasise once more the role of cyst-passers in the spread of infection and the importance of biochemical identification of the amoebic isolates, enabling more specific treatment.

Exercise-induced paroxysmal atrioventricular block during nuclear perfusion stress testing: evidence for transient ischemia of the conduction system

BACKGROUND

Whether tachycardia-dependent paroxysmal AV block, an uncommon complication of exercise stress testing in patients with infranodal conduction disturbances, can result from acute ischemia of the conduction system is still speculative, and is based on post-hoc evidence of right coronary artery disease and abolition of block after coronary angioplasty.

METHODS AND RESULTS

In two patients, from a database of 3000 undergoing nuclear exercise stress testing, transient paroxysmal AV block developed 1-4 minutes after the injection of the radionuclide agent. Nuclear perfusion imaging demonstrated stress-induced ischemia of the posteroseptal segments, which corresponds to the anatomical region of the His bundle, and perfusion recovery in the images obtained at rest. Angiography disclosed critical narrowing of the right coronary artery in both cases.

CONCLUSION

Nuclear myocardial perfusion imaging provides noninvasive evidence that transient ischemia of the posteroseptal segment, anatomically corresponding to the His bundle, can result in paroxysmal AV block in patients with severe right coronary artery and chronic infranodal conduction disturbances. The demonstration of the underlying pathophysiological mechanism is useful for selecting the most effective treatment strategy.

Enumeration of CD34+ hematopoietic progenitor cells for clinical transplantation: comparison of three different methods

Three different methods for determination of CD34+ cells in G-CSF-mobilized peripheral blood were compared. The methods were: the Milan/Mulhouse protocol, the ISHAGE guidelines for CD34+ cells enumeration and our own protocol. The procedure we have adopted is essentially a Milan/Mulhouse protocol-derived methodology combined with a multiparametric approach using the PAINT-A-GATE software analysis program. The samples were collected from 70 patients affected by acute leukemia, non-Hodgkin's lymphoma, Hodgkin's lymphoma, myeloma and breast cancer who were scheduled to receive autologous PBSC transplantation. PBSC collection was performed following mobilization with subcutaneous G-CSF at 5-10 microg/kg/day. A minimum target of 2 x 10(6)/kg CD34+ cells was considered an acceptable harvest to ensure a safe transplant. On average, three aphereses per patient were performed and a total of 204 apheresis samples were analyzed. Regression analysis of the percentage and absolute number of CD34+ cells, as calculated with each method, achieved an excellent correlation in spite of methodological differences. In fact, both CD34+dim and CD34+CD45- events were included in our gating strategy. In the setting of a triple staining associating CD34, CD38 and CD45, we identified a variable fraction of CD34+CD38+CD45- cells which would be otherwise undetected due to its CD45 negativity. To this end, we used a new technology referred to as laser-scanning cytometry (LSC) which allowed the isolation and morphological identification of CD34+CD45- cells. By comparing CD34+CD45+ and CD34+CD45- cells, we found that they share a common morphology, thus confirming the hypothesis that the latter are to be considered for CD34+ cell calculation. The median number of CD34+ cells/kg, as calculated by the three methods, was: 4.79 x 10(6)/kg (range 1-570) for the Milan/Mulhouse protocol, 3.9 x 10(6)/kg (range 0.8-498) for the ISHAGE one, and 5.17 x 10(6)/kg (range 2-599) for our protocol. The median time to ANC and PLT engraftment was 11 (range 9-24) and 20 (range 10-70) days, respectively. Our protocol achieved the best correlation between CD34+ cells/kg and time to ANC/PLT recovery according to the Spearman's rank test (r = -40 and P < 0. 015 for ANC, r= -46 and P = 0.005 for PLT). We conclude that (1) CD45 does not appear the ideal partner of HPCA-2 for determination of hematopoietic progenitors in mobilized peripheral blood; and (2) for clinical application, a single staining with 8G12 appears simple, reliable and feasible when rigorous procedures for sample preparation and acquisition are followed and an adequate software for multiparametric analysis is available.

Scintigraphic imaging and absorption of a 5-aminosalicylic acid enema in patients with ileorectal anastomosis

Ileorectal anastomosis (IRA) is a possible surgical treatment for hyperacute and drug-unresponsive forms of ulcerative colitis (UC). UC relapses in the rectal remnant usually are prevented by chronic administration of 5-aminosalicylic acid (5-ASA) in topical formulations. The relationships between intestinal absorption and pattern of luminal spread of 5-ASA enemas are still unknown in patients with IRA. We correlated the absorption of a 5-ASA enema with its spread in the distal bowel of patients with IRA as assessed by 99mTc radioenema imaging.

METHODS

Eight patients with UC in remission and previous IRA received a therapeutic 50-mL 5-ASA enema labeled with 99mTc-sulfer colloid. Absorbed 5-ASA and its major metabolite, acetyl 5-ASA, were measured in plasma, and dynamic images of radiolabeled enema were obtained for 6 h. The retrograde ileal spread (RIS) was determined and expressed as percentage of total enema radioactivity. Plasma levels of 5-ASA and acetyl 5-ASA were measured in six healthy volunteers after administration of the same enema volume with no radiolabeling.

RESULTS

The mean 5-ASA plasma level was 0.70 microg/mL (range 0.37-0.95 microg/mL) in patients and 0.96 microg/mL (range 0.78-1.16 microg/mL) in healthy volunteers (P = not significant), and the mean acetyl 5-ASA plasma levels were 0.89 microg/mL (range 0.44-1.19 microg/mL) and 0.84 microg/mL (range 0.51-1.02 microg/mL), respectively (P = not significant). Radioenema imaging allows RIS assessment of patients with IRA. The mean value was 8.5% (range 2%-19.3%) of administered radioactivity, which correlated significantly with the total absorption of 5-ASA in the IRA group (P = 0.033, linear correlation test). Rectal wall contractions recognized by dynamic radioenema imaging were defined as a common cause of RIS episodes.

CONCLUSION

In IRA patients, 5-ASA plasma levels were similar to those in healthy volunteers after administration in enema. Only part of a 50-mL 5-ASA enema reaches the ileum, and radiolabeled imaging shows the degree and number of these RIS episodes. The absorption of 5-ASA can increase in patients compared with healthy volunteers, in the presence of either occasional but significant ileal spread associated with postural factors and abdominal wall contraction or multiple moderate episodes of radioenema backdiffusion related to rectal wall motility.

Acute methylprednisolone administration induces a transient alteration of glucose tolerance and pyruvate dehydrogenase in humans

BACKGROUND

Glucocorticoid administration induces alteration of glucose tolerance, and impairment of glucose oxidation may contribute to glucocorticoid-induced derangement of glucose metabolism. We investigated glucose tolerance following methylprednisolone administration in humans. In the same model, we evaluated pyruvate dehydrogenase (PDH), the rate limiting enzyme of glucose oxidation, in peripheral blood mononuclear cells.

MATERIALS AND METHODS

Methylprednisolone (2 x 40 mg, iv, one dose every 12 h) was administered to six healthy volunteers. Glucose tolerance was evaluated through an oral glucose tolerance test (oGTT, 75 g glucose) at least a week before and after drug administration (2 and 24 h post-drug). To assess modifications of lipid metabolism circulating free fatty acids (FFA) and glycerol were measured, during fasting and oGTT. The active form of PDH (PDHa) was evaluated in peripheral blood mononuclear cells, both as ex vivo activity and as in vitro response to insulin (30 pmol l-1).

RESULTS

Methylprednisolone induced an alteration of glucose tolerance 2 h after its administration. Such alteration was completely reversed at 24 h. Alteration of glucose tolerance was accompanied by decreased ex vivo PDHa activity. PDH responsiveness to insulin in vitro was also impaired. Circulating FFA were unmodified, but decreased glycerol levels suggested a slight inhibition of lipolysis.

CONCLUSIONS

Acute methylprednisolone administration in humans induced a transient decrease of glucose tolerance 2 h after drug administration, accompanied by hyperinsulinaemia, inhibition of ex vivo PDH activity and its response to insulin in vitro. These alterations were completely abolished at 24 h, suggesting that methylprednisolone can be safely administered acutely. Furthermore, methylprednisolone induced only minor modifications of circulating FFA and glycerol, indicating minimal impact on lipid metabolism.

Femoral catheters: safety and efficacy in peripheral blood stem cell collection

Central venous access is necessary in patients candidate for peripheral blood stem cell (PBSC) collection. We report our experience with a dual lumen femoral catheter (Gamcath, 11 french), initially designed for hemodialysis. We studied 147 patients and performed 488 collections after mobilization with either G-CSF alone or chemotherapy + G-CSF, when the white blood cell count exceeded 1 x 10(9)/L, or when a measurable population of CD34+ cells (20/microL) was detected in peripheral blood. All patients received systemic anticoagulation with a low weight heparin and ultrasound examination was performed after the removal of the catheter. Seven patients developed thrombosis (4.7%), ten experienced hematomas at the site of catheter placement (6.8%) despite prophylactic platelet transfusions, while only one patient (0.6%) had a catheter-related infection. In conclusion, the short-term use of large bore femoral catheters in setting up PBSC collection seems to be associated with minimal risk of infection and low thrombotic incidence.

[Quality of data or quality of care? Comparison of diverse standarization methods by clinical severity, based on the discharge form, in the analysis of hospital mortality]

Using discharge abstract data, we analysed hospital mortality comparing four different methods of risk adjustment. All patients discharged from the S. Giovanni Battista (Molinette) hospital in Turin (Italy) between January 1996 and June 1999 (n = 169,746) were classified with All Patient Refined--Diagnosis Related Groups (APR-DRG). A first analysis evaluated the time trend of hospital mortality by semester. A second analysis compared hospital mortality during the last 12 months among eight units of internal medicine (n = 5592). All comparisons were made through logistic regression models. As the quality of discharge abstracts increased during time and showed variation among units with similar patients, all comparisons were repeated using four models, characterised by increasing predictivity and sensitivity to quality of data. In addition to crude comparisons (A), the other models included as risk factors: B) age and emergency admission; C) same as 'B' plus expected mortality by APR-DRG; D) same as 'B' plus expected mortality by APR-DRG and risk of death subclass. If no risk factors were considered (A), hospital mortality showed an increasing trend, with an odds ratio (OR) of 1.02 by semester, with a 95% confidence interval (CI) between 1.01 and 1.03. The association was weakened when age and mode of admission were taken into account (B) and disappeared when the APR-DRG expected mortality was also considered (C) (OR = 1.00; CI = 0.98-1.01). Finally, if the comparisons were adjusted also for the expected mortality by APR-DRG and risk of death subclass (D) a reversed trend appeared (OR = 0.95; CI = 0.94-0.97). The comparison among the units of internal medicine gave discordant results according to the method used to adjust for confounders. The most striking variations were detected for those units with the best and the worst clinical data. The unit with the poorer clinical data (average number of diagnoses per patient = 2.9) showed a crude OR of 1.38 (CI = 0.99-1.93) and an adjusted OR (D) of 1.71 (CI = 1.10-2.66); the unit with the best quality of data (average number of diagnoses per patient = 4.4) changed the OR from 1.55 (CI = 1.06-2.26) (A) to 0.66 (CI = 0.37-1.17) (D). In conclusion, these results confirm the high sensitivity of the APR-DRG classification to the quality of data and, more in general, suggest to be prudent when using powerful instruments like this to assess quality of care, especially if the quality of data among the units compared is less than optimal or not homogeneous.

Multicentre magnetic resonance texture analysis trial using reticulated foam test objects

Texture analysis in magnetic resonance imaging has the ability to provide useful diagnostic information with respect to the discrimination of disease states of a single tissue or the separation of different tissues. However, for widespread use it is necessary to determine how texture measurements carried out in one center relate to those carried out in another. To this end, a multicentre trial has been performed where reticulated foam test objects have been scanned in six European centers according to a fixed protocol. It has been concluded that texture measurements are not transportable between centers. Principal component models calculated from the texture parameters collected in one center do not fit the data collected in another. Further trials are to investigate whether the reticulated foam test objects may be used to normalize tissue texture data collected in different centers.

Experimental respiratory cryptosporidiosis in immunosuppressed rats: a light and electron microscopy study

Cryptosporidium parvum is a coccidian protozoon that causes diarrhoeal enteritis in immunocompetent and immunocompromised humans and other mammals. Sometimes, chiefly in HIV-infected subjects, anatomical sites other than gastro-intestinal tract, such as the biliary and respiratory tree, are involved. We performed an experimental respiratory infection in immunosuppressed albino rats with a C. parvum human-derived isolate, to confirm the possibility of a primary infection at this site and to evaluate the protozoan damages by light and also by transmission electron microscopy (TEM). The animals were infected intratracheally with 1 x 10(6) C. parvum oocysts/ml and, from the 7th day post-infection, biological specimens of trachea, bronchi, lung and ileum were zoopsied. A sole cryptosporidial colonization of the respiratory tract, from the trachea to the median bronchi, without lung parenchyma infection, was observed. Moreover 13/33 (39.4%) rats also developed intestinal infection. TEM study of the respiratory tree specimens demonstrated that cryptosporidia infect either ciliated or goblet cells, and confirmed the role of microvilli in the parasite cell adhesion. The most relevant alterations involved the ciliated cells, with loss of cilia and nuclear and cytoplasmic damages.

Alteration of SREBP activation in liver of trisomy 21 fetuses

We previously reported that trisomy 21 (T21) fetuses have an intrinsic lipid metabolism abnormality resulting in higher serum cholesterol levels than their matched controls. In an attempt to clarify the biochemical basis of this derangement we analyzed the liver cholesterol levels and activation of the sterol regulatory element binding proteins SREBP-1 and SREBP-2. We report here for the first time that SREBP-1 and SREBP-2 are present in human fetal liver and their activation follows a different regulatory pattern. Moreover T21 fetuses show a peculiar pattern of SREBP activation which, at variance from control fetuses, involves sterol-independent maturation of SREBP-1. Multiple defects accompanied the lipid derangement in T21, resulting in high circulating and tissue cholesterol. This may serve as an early biochemical marker of an unknown, possibly genetically determined mechanism, whose consequence on lipid homeostasis during postnatal and adult life is still not understood.

The contribution of the ossific nucleus to the structural stiffness of the capital femoral epiphysis: a porcine model for DDH

The preosseous femoral head is thought to be vulnerable to compressive ischemic injury during the treatment of developmental dysplasia of the hip. The ossific nucleus has been proposed to increase the mechanical strength of the capital femoral epiphysis (CFE) and to decrease the risk of avascular necrosis. Sixty mixed-breed fetal and postgestational femoral head specimens were evaluated for structural stiffness in relation to the size of the ossific nucleus within the CFE. The structural stiffness of the CFE in the porcine model was found to increase exponentially with the size of the ossific nucleus. A finite-element model revealed that the presence of an ossific nucleus occupying 40% of the epiphyseal volume reduced the compressive strain in the region of the posterior-superior branch of the medial circumflex artery by an average of 54%. The results of this study support the hypothesis that the presence of the ossific nucleus may protect the CFE from compressive ischemic injury in the treatment of DDH.

P-glycoprotein and terminal transferase expression identify prognostic subsets within cytogenetic risk classes in acute myeloid leukemia

Clinical and biological features were assessed in 204 consecutive de novo adult acute myeloid leukemia (AML) patients who received intensive chemotherapy regimens. Multiparameter flow cytometric assays both of the multidrug resistance (MDR-1)-associated P-glycoprotein (PGP) using the UIC2 monoclonal antibody (MoAb), and of terminal transferase (TdT) were performed. Cytogenetic findings were obtained from 196 patients with high resolution banding. At onset, UIC2 and TdT positivities were detected in 58.5% and 24% of cases, respectively. There were strict correlations either between UIC2 negativity and FAB M3 or between TdT and FAB M0-M1 (P = 0.001 and < 0.0001, respectively). On the other hand, age was significantly associated with cytogenetic risk classes (P < 0.0001). CD34 positivity was highly correlated with TdT expression (P < 0.0001). Moreover, CD7 and CD11b were significantly represented in UIC2+ subset (P < 0.0001). Rhodamine 123 (Rh 123) efflux was significantly higher in 75 UIC2 positive patients compared to 65 UIC2 negative ones (P < 0.001). As regards to cytogenetics, TdT positivity was strongly related either to t(9;22) or single/associated anomalies of chromosome 7; on the other hand, most or all cases with t(8;21) or t(15;17) were UIC2 or TdT negative, respectively. The rate of first complete remission (CR) differed both between UIC2+ and UIC2- cases and between TdT+ and TdT- ones (40% versus 72%, P < 0.001; and 36% versus 61%, P = 0.001, respectively). The survival rates (Kaplan-Meier method) were significantly shorter either in UIC2+ or in TdT+ patients (P = 0.005 and = 0.011, respectively). UIC2 and TdT negative cases showed longer remission duration (P = 0.03 and = 0.22, respectively). The additional effect of UIC2 and TdT on prognosis allowed us to identify two subsets of patients, the first [UIC2- TdT-] at better and the second [UIC2+ TdT+] at worse clinical outcome compared to single UIC2 and TdT cases, concerning CR (P < 0.001), survival (P < 0.0001) and CR duration (P = 0.007). The combinations [UIC2+ TdT-] and [UIC2- TdT+] showed an intermediate clinical course. A strong difference was found between poor risk and intermediate/favorable risk cytogenetic classes with regard to CR rate (P < 0.0001), overall survival and CR duration (P < 0.001). Nevertheless, within the poor risk class, UIC2 positivity was able to identify patients at worst prognosis with regard to CR (P = 0.005), survival (P = 0.02) and CR duration (P = 0.015). On the other hand, UIC2 and TdT negativity allowed us to distinguish patients with longer survival (P = 0.012 and = 0.04, respectively) and CR duration (P = 0.04 and = 0.025, respectively) within the intermediate/favorable risk class. The independent prognostic value of UIC2, TdT and cytogenetic risk classes was confirmed in multivariate analysis. These results suggest that PGP and TdT expressions, together with cytogenetic findings, may represent a basic predictor of chemotherapeutic failure in AML.