Acute splenic sequestration in a cohort of children with sickle cell anemia

OBJECTIVE

To analyze acute splenic sequestration (ASS) in children with sickle cell anemia diagnosed through a newborn screening program in the state of Minas Gerais, Brazil, and followed up at the hematology center in the city of Belo Horizonte, Minas Gerais, Brazil.

METHODS

Retrospective cohort of 255 children with sickle cell anemia (Hb SS/Sbeta(0)) born between January 01, 2000, and December 31, 2004, and followed up until December 31, 2006. Data were abstracted from the patients' medical records.

RESULTS

A total of 89 patients had 173 episodes of ASS (10.2 first episodes per 100 patient-years); 75% of the first episodes occurred before 2 years of age. The estimated probability of occurrence of the first episode of ASS during the study period was 40%. Recurrence rate reached 57.3%. After the first episode, splenectomy was indicated in only 12.4% of the cases; after the second, in 60.4% of the cases. After the third episode, 41.7% of the patients remained under clinical observation. The median time between indication for splenectomy and the actual surgical procedure was 2 months. During the intervening period, 37.2% of the children suffered a new episode of ASS and one child died. Case-fatality rate was 1.1% for the first episode and 7.8% for the subsequent episodes. Among a total of 255 children, 19 died: 36.8% due to infections and 26.3% after ASS.

CONCLUSIONS

ASS is relatively common in sickle cell anemia, mainly in the first 2 years of life; relapse occurs in more than half of the cases. Conservative management instead of immediate splenectomy was the method of choice. Although the case-fatality rate was low, ASS was the second most common cause of death. These results disclose some fragilities of the health system in the state of Minas Gerais and the need for better professional education to approach ASS crises.

Prognostic significance of WT1 gene expression in pediatric acute myeloid leukemia

BACKGROUND

The Wilms Tumor gene (WT1) encodes a transcription factor involved in kidney development and malignancy. WT1 expression in a subpopulation of early CD34+ cells has suggested its involvement in hematopoiesis. WT1 is aberrantly expressed in leukemias. High expression of WT1 at diagnosis has been associated with unfavorable prognosis in adult acute myeloid leukemia (AML). The prognostic relevance of WT1 expression in pediatric AML was evaluated in only one study, including 47 patients, which showed that very low levels of WT1 at presentation were associated with an excellent outcome. To test the validity of these findings we measured levels of WT1 in 41 newly diagnosed pediatric AML of the non-M3 FAB subtype.

PROCEDURE

Patients were treated according to an AML-BFM 83-based protocol in a single institution. Mononucleated cells obtained from presentation BM aspirates were cryopreserved and later thawed and used for total RNA extraction and cDNA synthesis. The quantitative assessment of WT1 transcripts was made by real-time PCR (RQ-PCR). WT1 transcripts values were normalized with respect to the number of ABL transcripts.

RESULTS

WT1 levels were significantly higher in patients bearing favorable chromosome abnormalities, t(8;21) and inv(16) (P = 0.002). Higher levels of WT1 expression were unexpectedly associated with a higher probability of overall survival by Cox regression analysis (P = 0.002). Multivariate regression analysis could not discriminate between the effects of WT1 and cytogenetics on survival.

CONCLUSIONS

Higher WT1 expression was associated with favorable cytogenetics subtypes and accordingly with better outcome in children with AML in this study.

Effect of Erythrina velutina and Erythrina mulungu in rats submitted to animal models of anxiety and depression

Erythrina velutina (EV) and Erythrina mulungu (EM), popularly used in Brazil as tranquilizing agents, were studied. The effects of acute and chronic oral treatment with a water:alcohol extract of EV (7:3, plant grounded stem bark; acute = 100, 200, 400 mg/kg; chronic = 50, 100, 200 mg/kg) were evaluated in rats (N = 11-12) submitted to the elevated T-maze (for avoidance and escape measurements) model of anxiety. This model was selected for its presumed capacity to elicit specific subtypes of anxiety disorders recognized in clinical practice: avoidance has been related to generalized anxiety and escape to panic. Additionally, animals were treated with the same doses of EV and EM (water:alcohol 7:3, inflorescence extract) and submitted to the forced swim test for the evaluation of antidepressant activity (N = 7-10). Both treatment regimens with EV impaired elevated T-maze avoidance latencies, without altering escape, in a way similar to the reference drug diazepam (avoidance 1, mean +/- SEM, acute study: 131.1 +/- 45.5 (control), 9.0 +/- 3.3 (diazepam), 12.7 +/- 2.9 (200 mg/kg), 28.8 +/- 15.3 (400 mg/kg); chronic study: 131.7 +/- 46.9 (control), 35.8 +/- 29.7 (diazepam), 24.4 +/- 10.4 (50 mg/kg), 29.7 +/- 11.5 (200 mg/kg)). Neither EV nor EM altered measurements performed in the forced swim test, in contrast to the reference drug imipramine that significantly decreased immobility time after chronic treatment. These results were not due to motor alterations since no significant effects were detected in an open field. These observations suggest that EV exerts anxiolytic-like effects on a specific subset of defensive behaviors which have been associated with generalized anxiety disorder.

Clinical course of autoimmune hemolytic anemia: an observational study

OBJECTIVE

Autoimmune hemolytic anemia is characterized by the production of autoantibodies against erythrocyte membrane antigens. This study was carried out to identify the clinical, immunological and outcome characteristics of autoimmune hemolytic anemia patients treated at the (HC-UFMG) Pediatric Hematology Unit and the Hemocentro de Belo Horizonte.

METHODS

We evaluated 17 patients younger than 15 years old admitted from 1988 to 2003 were evaluated. Autoimmune hemolytic anemia diagnosis was based on the presence of acquired hemolysis and confirmed by positive direct Coombs polyspecific test results. Clinical, laboratory, and outcome data were obtained from patient records.

RESULTS

The median age at diagnosis was 10.5 months. The direct Coombs polyspecific test was positive in 13 and negative in four patients. Monospecific testing was performed for 14 patients. The most frequent red cell autoantibody was IgG (five patients), followed by IgM in two. Thirteen patients had severe anemia and needed blood transfusions. Underlying diseases were identified in four patients: systemic lupus erythematosus, Hodgkin's lymphoma, autoimmune hepatitis and Langerhans cell histiocytosis. The remaining patients were classified as having primary disease. The median follow-up period was 11 months (5 to 23 months). Three children died, two after splenectomy and one with complications of the underlying disease.

CONCLUSION

Autoimmune hemolytic anemia is rare in children and adolescents. Although patients usually respond to corticosteroids and/or immunoglobulin, fatal cases can occur. Prognosis is worse in patients with chronic underlying diseases.

The inactivation of the basolateral nucleus of the rat amygdala has an anxiolytic effect in the elevated T-maze and light/dark transition tests

Pharmacological evidence indicates that the basolateral nucleus of the amygdala (BLA) is involved in the mediation of inhibitory avoidance but not of escape behavior in the elevated T-maze test. These defensive responses have been associated with generalized anxiety disorder (GAD) and panic disorder, respectively. In the present study, we determined whether the BLA plays a differential role in the control of inhibitory avoidance and escape responses in the elevated T-maze. Male Wistar rats (250-280 g, N = 9-10 in each treatment group) were pre-exposed to one of the open arms of the maze for 30 min and 24 h later tested in the model after inactivation of the BLA by a local injection of the GABA A receptor agonist muscimol (8 nmol in 0.2 microL). It has been shown that a prior forced exposure to one of the open arms of the maze, by shortening latencies to withdrawal from the open arm during the test, improves the escape task as a behavioral index of panic. The effects of muscimol in the elevated T-maze were compared to those caused by this GABA agonist in the avoidance reaction generated in the light/dark transition test. This defensive behavior has also been associated with GAD. In the elevated T-maze, intra-BLA injection of muscimol impaired inhibitory avoidance (control: 187.70 +/- 14.90 s, muscimol: 37.10 +/- 2.63 s), indicating an anxiolytic effect, without interfering with escape performance. The drug also showed an anxiolytic effect in the light/dark transition test as indicated by the increase in the time spent in the lighted compartment (control: 23.50 +/- 2.45 s, muscimol: 47.30 +/- 4.48 s). The present findings point to involvement of the BLA in the modulation of defensive responses that have been associated with GAD.

Inefficacy of piracetam in the prevention of painful crises in children and adolescents with sickle cell disease

Analgesia and hydration remain the only safe treatment for painful crises of sickle cell disease; hydroxyurea is effective, but the toxicity is still a problem. Piracetam is a nootropic drug that has reportedly been effective and non-toxic in sickle cell patients, but most studies were not placebo-controlled and included a small number of patients. The present study evaluated the drug in a double-blind crossed placebo-controlled clinical trial in 73 children and adolescents suffering from moderate to severe painful crises for 13 months. Information regarding frequency and severity of pain was acquired through monthly clinical evaluation, visits and house calls, and 4,300 weekly questionnaires filled out by the patients in their domiciles. A monthly pain score was calculated for each patient. Pain was the most frequent adverse manifestation of the disease stressing its significant bio-psycho-social impact. Although nearly all patients and relatives reported a better clinical course throughout the whole study, the drug was ineffective in the prevention of painful crises. This placebo effect may be ascribed to an unplanned and unsystematic 'cognitive-behavioural' management of the children. The pain score in the second semester of the study - both in the experimental and in the control groups - was significantly smaller than that in the first semester. In conclusion, piracetam was found to be ineffective in the prevention of painful crises; a powerful placebo effect due to adequate patient care was demonstrated.

[Evaluation of compliance through specific interviews: a prospective study of 73 children with acute lymphoblastic leukemia]

OBJECTIVE

To evaluate compliance in children with acute lymphoblastic leukemia.

METHOD

Compliance was assessed through specific interviews.

RESULTS

A total of 73 patients who had concluded the maintenance phase of chemotherapy were enrolled on the study. Eighty-one percent of the interviews were conducted with the patients' mothers; 92% of the families stated that medical instructions had been understood well. Interviews indicated that 27% of the patients did not receive their medication twice or more during the maintenance phase, without medical direction for this. These children were considered non-compliant. Sixteen percent of the children failed to receive their medication three times or more. The main reason for non-compliance was forgetfulness. In ten cases the reported dosage of drugs was not that which was prescribed. No significant associations of non-compliance with parents' schooling level, number of family members or per capita family income were detected. The 8.5-year estimated probability of event free survival was 72.4% (95% CI: 59.2-82.3). The event free survival curves for non-compliant children were not statistically different from those for the compliant group.

CONCLUSIONS

Results suggest that comprehensive approaches to the problem of non-compliance are urgently needed.

Risk factors for alloimmunization by patients with sickle cell disease

Blood transfusion in patients with sickle cell disease (SCD) is limited by the development of alloantibodies to erythrocytes. In the present study, the frequency and risk factors for alloimmunization were determined. Transfusion records and medical charts of 828 SCD patients who had been transfused and followed at the Belo Horizonte Blood Center, Belo Horizonte, MG, Brazil, were retrospectively reviewed. Alloimmunization frequency was 9.9% (95% CI: 7.9 to 11.9%) and 125 alloantibodies were detected, 79% of which belonged to the Rhesus and Kell systems. Female patients developed alloimmunization more frequently (P = 0.03). The median age of the alloimmunized group was 23.3 years, compared to 14.6 years for the non-alloimmunized group (P < 0.0001). Multivariate analyses were applied to the data for 608 hemoglobin (Hb) SS or SC patients whose number of transfusions was recorded accurately. Number of transfusions (P = 0.00006), older age (P = 0.056) and Hb SC (P = 0.02) showed independent statistical associations with alloimmunization. Hb SC patients older than 14 years faced a 2.8-fold higher (95% CI: 1.3 to 6.0) risk of alloimmunization than Hb SS patients. Female Hb SC patients had the highest risk of developing alloantibodies. In patients younger than 14 years, only the number of transfusions was significant. We conclude that an increased risk of alloimmunization was associated with older patients with Hb SC, specially females, even after adjustments were made for the number of transfusions received, the most significant variable.

Clinical and laboratory evaluation of compliance in acute lymphoblastic leukaemia

AIM

To evaluate compliance in children with acute lymphoblastic leukaemia (ALL).

METHODS

Compliance was assessed through specific interviews, annotations from medical charts, and erythrocytic determination of 6-mercaptopurine metabolites.

RESULTS

A total of 39 patients who had concluded maintenance phase of chemotherapy were included in the study. Mothers were responsible for delivering 6-MP in 87% of cases. Thirty five interviewees said that medical prescription was well understood and that the main reason for non-compliance was forgetfulness. Non-compliance was detected through interviews (33.3% of the cases), reports from medical charts (30.7%), and drug determination (16.6%); 53.8% of children were found to be non-compliant. Non-compliance was significantly associated with chronic undernourishment. Although not statistically significant, there was a trend for the group of non-compliant children to be associated with low per capita family income. No significant associations of non-compliance with age at diagnosis, gender, parents' schooling level, number of family members, power consumption, and medians of absolute leucocyte or neutrophil blood counts were detected. A short follow up period precluded valid analysis on outcome. In the non-compliant group (n = 21), seven children relapsed, contrasting with three relapses in the compliant group (n = 18).

CONCLUSIONS

Results suggest that non-compliance is one of the mechanisms which underlies the adverse influence of socioeconomic factors on the outcome of children with ALL. Additional studies are necessary to confirm this hypothesis. Comprehensive approaches to the problem of non-compliance are urgently needed.

An improved HPLC method for the quantitation of 6-mercaptopurine and its metabolites in red blood cells

A procedure is described for the rapid determination of the intra-erythrocyte concentration of 6-mercaptopurine (6-MP) and its metabolites, 6-thioguanine nucleotides (6-TGN) and 6-methylmercaptopurine (6-MMP). Erythrocytes (8 x 10(8) cells) in 350 microl Hanks solution containing 7.5 mg dithiothreitol were treated with 50 microl 70% perchloric acid. The precipitate was removed by centrifugation (13,000 g) and the supernatant hydrolyzed at 100 degrees C for 45 min. After cooling, 100 microl was analyzed directly by HPLC using a Radialpack Resolve C18 column eluted with methanol-water (7.5:92.5, v/v) containing 100 mM triethylamine. 6-TG, 6-MP and the hydrolysis product of 6-MMP, 4-amino-5-(methylthio)carbonyl imidazole, were monitored at 342, 322 and 303 nm using a Shimadzu SPD-M10A diode array UV detector. The analytes eluted at 5.3, 6.0 and 10.2 min, respectively. The calibration curves were linear (r(2) > 0.998), and the analytical recoveries were 73.2% for 6-TG, 119.1% for 6-MP and 97.4% for 6-MMP. The intra- and inter-assay variations were highest for 6-MP (9.6 and 14.3%, respectively). The lowest detectable concentrations were 3, 3 and 25 pmol/8 x 10(8) erythrocytes for 6-TG, 6-MP and 6-MMP, respectively. The quantification limits (coefficients of variation <15%) were 8, 10 and 70 pmol/8 x 10(8) erythrocytes for 6-TG, 6-MP and 6-MMP, respectively. The method was applied to the analysis of 183 samples from 36 children under chemotherapy for acute lymphoblastic leukemia. The concentrations of the metabolites in the red cells of the patients ranged from 0 to 1934 pmol/8 x 10(8) erythrocytes for 6-TGN, and from 0 to 105.8 and 0 to 45.9 nmol/8 x 10(8) erythrocytes for 6-MP and 6-MMP, respectively. The procedure gave results that were in agreement with those obtained with other methods designed to detect cases of non-compliance with treatment, including patient interviews and medical evaluation, among others, demonstrating its applicability to monitoring the treatment of leukemic children.

[Acute myeloid leukemia in childhood: 15-year experience in a single institution]

OBJECTIVE

To investigate the survival of children with acute myeloid leukemia (AML) before and after the introduction of a Berlin-Frankfurt-Munich-83 based protocol. To analyze the prognostic impact of age, gender, nutritional status, initial white blood cell count and use of etoposide in the remission induction phase.

METHODS

This partly prospective/retrospective study comprised 83 children with AML diagnosed at Hospital das Clínicas, Universidade Federal de Minas Gerais, Brazil, between 1986 and 2000. Before 1991, 15 children were treated with 2-3 pulses of cytarabin plus daunomycin, followed by several consolidation/maintenance schemes. From January 1991 to November 1992 a pilot study (n = 15) was carried out to test etoposide toxicity in the induction phase. Etoposide was randomized from December 1992 to June 1999.

RESULTS

Median follow-up period was 5 years. Initial remission rates were 40 and 66% before or after the introduction of the German protocol, respectively (p = 0.11). Induction failure was largely due to death caused by infection and/or hemorrhage. The 5-year estimated probabilities of survival and of continuous complete remission were 31+/-5.4% and 49.7+/-7.4%, respectively. All 22 relapses involved the bone marrow. Age below 6 years at diagnosis was significantly associated with a poor prognosis. Sex, initial leukocyte count, and nutritional variables were not significant prognostic factors. The randomized addition of etoposide in the induction phase unexpectedly decreased the probability of complete remission at 5 years.

CONCLUSIONS

The introduction of a German-based protocol in 1991 significantly improved survival and duration of first remission. No plausible explanation for the unfavorable effect of etoposide was found.

Direct association of socio-economic status with T-cell acute lymphoblastic leukaemia in children

Lymphoblasts from 186 consecutive untreated children <18 years were analysed by flow cytometry in Brazil. Socio-economic status was defined by family income; undernourishment by height and weight for age standardised z scores below -1.28. The observed frequencies were precursor-B (pre-B) CD10 positive acute lymphoblastic leukaemia (ALL) (CD10+) 65%, pre-B CD10 negative (CD10-) 13%, and T-ALL 18%. The typical incidence peak at age 2-5 years was observed among the CD10 positive cases. Nutritional variables were not associated with immunophenotypes. Low monthly per capita income was associated with T-immunophenotype (P=0.024). In conclusion, a direct association between unfavourable socio-economic status and the T-phenotype indicates a potential role of socio-economic factors on the genesis of ALL in children, thus confirming indirect data of the international literature.

[Clinical and nutritional aspects of Gaucher disease: prospective study of 13 children at a single center]

OBJECTIVE

Gaucher disease is an autosomal recessive lysosomal storage disease, caused by mutation to the GBA gene (glucocerebrosidase gene) located on chromosome 1. The objective of the present study was to identify the clinical, nutritional, biochemical and genetic features of the patients with Gaucher disease treated at the Unit of Pediatric Hematology (Hospital das Clínicas-Universidade Federal de Minas Gerais).

METHODS

Thirteen patients were prospectively followed up. Gaucher disease was confirmed in all patients through the use of an enzyme assay test to measure glucocerebrosidase enzyme activity. Demographic and nutritional data, and biochemical findings obtained on admission, were studied. Genetic testing was performed in seven patients. The median age of follow-up was 5.3 years. Z scores for weight and height on admission and at the end of observation period were calculated. The standardized prevalence for malnutrition was calculated using the Mora method.

RESULTS

The mean age at diagnosis was 5.8 years. The predominant clinical manifestations at diagnosis were hepatomegaly and splenomegaly, and all patients were classified as clinical type 1. Low platelet count and anemia were detected at diagnosis in eight and six children, respectively. The most frequent genetic mutation was N370S. One child died during follow-up due to septicemia, after splenectomy. The prevalence of malnutrition was 26% at admission and 48% at the end of the observation period.

CONCLUSION

The analysis of data demonstrates that N370S and clinical type 1 predominate in our Unit, characterizing the milder form of the disease. The irregular enzyme replacement therapy during the study period did not allow valid clinical conclusions on its efficacy.

Effect of acute treatment with a water-alcohol extract of Erythrina mulungu on anxiety-related responses in rats

We investigated the effect of acute oral treatment with a water-alcohol extract of the inflorescence of Erythrina mulungu (EM, Leguminosae-Papilionaceae) (100, 200 and 400 mg/kg) on rats submitted to different anxiety models: the elevated T-maze (for inhibitory avoidance and escape measurements), the light/dark transition, and the cat odor test. These models were selected for their presumed capacity to demonstrate specific subtypes of anxiety disorders as recognized in clinical practice. Treatment with 200 mg/kg EM impaired avoidance latencies (avoidance 1 - 200 mg/kg EM: 18 +/- 7 s, control group: 40 +/- 9 s; avoidance 2 - 200 mg/kg EM: 15 +/- 4 s, control group: 110.33 +/- 38 s) in a way similar to the reference drug diazepam (avoidance 1: 3 +/- 0.79 s; avoidance 2: 3 +/- 0.76 s), without altering escape. Additionally, the same treatments increased the number of transitions (200 mg/kg EM: 6.33 +/- 0.90, diazepam: 10 +/- 1.54, control group: 2.78 +/- 0.60) between the two compartments and the time spent in the lighted compartment in the light/dark transition model (200 mg/kg EM: 39 +/- 7 s; diazepam: 61 +/- 9 s; control group: 14 +/- 4 s). The dose of 400 mg/kg EM also increased this last measurement (38 +/- 8 s). These results were not due to motor alterations since no significant effects were detected in the number of crossings or rearings in the arena. Furthermore, neither EM nor diazepam altered the behavioral responses of rats to a cloth impregnated with cat odor. These observations suggest that EM exerts anxiolytic-like effects on a specific subset of defensive behaviors, particularly those that have been shown to be sensitive to low doses of benzodiazepines.

Serotonergic regulation of inhibitory avoidance and one-way escape in the rat elevated T-maze

It has been proposed that distinct 5-HT pathways modulate different types of anxiety. Activation of the ascending dorsal raphe (DR)-5-HT pathway, innervating the amygdala and frontal cortex, would facilitate learned defensive behaviors. On the other hand, activation of the DR-periventricular 5-HT pathway, which innervates the dorsal periaqueductal gray matter (DPAG), would inhibit innate flight or fight reactions. Dysfunction of these pathways has been suggested to relate to generalized anxiety disorder (GAD) and panic disorder (PD) in humans, respectively. The elevated T-maze has been developed to separate conditioned (inhibitory avoidance) from unconditioned (escape) defensive responses in the same rat. Pharmacological validation of this model has shown that the GAD-effective serotonergic anxiolytic buspirone or the putative anxiolytic ritanserin selectively impaired inhibitory avoidance while leaving one-way escape unchanged. Chronic injection of the 5-HT/noradrenaline reuptake inhibitor imipramine impaired inhibitory avoidance and prolonged escape, an effect that may be related to the therapeutic action of this drug on both GAD and PD. Like imipramine, intra-DPAG injection of the 5-HT(1A) agonist 8-OH-DPAT impaired both inhibitory avoidance and one-way escape. Intra-DPAG administration of the 5-HT(2A/2C) agonist DOI prolonged escape, without affecting inhibitory avoidance. The reversible inactivation of the DRN by muscimol impaired inhibitory avoidance, while facilitating escape from the open arm. Taken together, these results suggest that 5-HT exerts differential control on inhibitory avoidance and escape response in the elevated T-maze, mobilizing different types of 5-HT receptors in key structures implicated in fear/anxiety.

Reliability of isoelectrofocusing for the detection of Hb S, Hb C, and HB D in a pioneering population-based program of newborn screening in Brazil

Out of 128,326 newborns in the first 6-month period of a population-based screening program in Minas Gerais, Brazil, a second sample was obtained at the age of 6 months from 4,635 carriers of Hbs AS, AC, and AD which were detected by isoelectrofocusing. Discordance in results occurred in only 27 cases (0.6%): in seven there was a history of hemotransfusion; errors during pipetting or transcription of results occurred in seven cases; it was difficult to differenciate between Hbs S and D in eight patients; and the causes were not elucidated in five patients. The incidence of Hbs FS and FSC for the total population was 1:2,800 and 1:3,450, respectively. Isoelectrofocusing is a very reliable method for distinguishing AS, AC, or AD carriers from patients presenting with [corrected] variant hemoglobin and beta(+)-thalassemia combinations, and may be widely used in massive newborn screening programs.

Lack of association between N-ras gene mutations and clinical prognosis in Brazilian children with acute lymphoblastic leukemia

Point mutations in codons 12, 13 and 61 of the N-ras proto-oncogene have been detected in several human malignancies. We studied 170 patients with acute lymphoblastic leukemia (ALL), treated from 1988 to 1994 according to a protocol derived from BFM-83 studies, in order to evaluate the incidence and prognostic significance of mutations in this gene in childhood ALL. DNA was extracted from bone marrow smears at diagnosis and amplified by polymerase chain reaction (PCR). After screening with SSCP, PCR products were hybridized with allele specific probes and, in some cases, cloned in a pMOS Blue T vector and sequenced. Exon 2 was also studied in 101 children. Our results showed 4% of mutations in codons 12 and 13 and 2% in exon 2. Similar to a previous report, we identified 7% of mutations among children who were studied for both exons. A new mutation in codon 64 of the N-ras gene was detected in one patient. No significant clinical differences between patients with and without mutations were detected (sex, age, leukocyte counts at diagnosis, nutritional status, and risk factor according to the BFM protocol). Children with mutations in codons 12 and 13 showed significantly higher reactivity to PAS staining on blast cells than children with a wild type N-ras gene configuration. Comparison of overall- and recurrence-free survival did not show significant difference between groups with and without mutations. Our results suggest that mutations in the ras gene are infrequent in children with ALL at diagnosis and seem to be of low prognostic value.

The spectrum of mutations, including four novel ones, in the thiamine-responsive megaloblastic anemia gene SLC19A2 of eight families

Thiamine responsive megaloblastic anemia (TRMA) is an autosomal recessive disorder with a triad of symptoms: megaloblastic anemia, deafness, and non-type 1 diabetes mellitus. Occasionally, cardiac abnormalities and abnormalities of the optic nerve and retina occur as well. Patients with TRMA often respond to treatment with pharmacological doses of thiamine. Recently, mutations were found in patients with TRMA in a thiamine transporter gene (SLC19A2). We here describe the mutations found in eight additional families. We found four novel mutations and three that were previously described. Of the novel ones, one is a nonsense mutation in exon 1 (E65X), two are missense mutations in exon 2 (S142F, D93H), and another is a mutation in the splicing donor site at the 5' end of intron 4 (C1223+1G>A). We also summarize the state of knowledge on all mutations found to date in TRMA patients. SLC19A2 is the first thiamine transporter gene to be described in humans. Reviewing the location and effect of the disease causing mutations can shed light on the way the protein functions and suggest ways to continue its investigation.

[Hodgkińs disease in childhood: a sixteen year experience in a single institution]

OBJECTIVES: To report the experience in the treatment of Hodgkińs lymphoma in children at Hospital das Clínicas, UFMG, Brazil.METHODS: 31 children with Hodgkińs lymphoma were retrospectively followed up from 1983 to 1999. Fifteen children were treated according to HD-85, a protocol based on German-Austrian studies; the 16 remaining children were treated otherwise.RESULTS: The age at diagnosis varied from 3 to 15 years (median 9 years). There were 28 male patients. The follow-up period ranged from 2 months to 16 years (median 3 years and 7 months). Mixed cellularity was the predominant (61%) histological subtype; 58% had advanced disease (stages III or IV) at diagnosis. Staging abdominal surgery was necessary in 61%. No reduction in the frequency of staging surgeries was observed after starting standardized HD-85 protocol in 1994. Herpes simplex and zoster infections were the most common complications. The estimated probability of disease-free survival (DFS) was 55.6%-/+11.7% at 5 years. Overall survival probability was 96.5%-/+3.5%. No difference in DFS was apparent between children treated with HD-85 and those treated otherwise.CONCLUSIONS: The overall results in DFS are worse than those reported in the literature. The predominance of mixed cellularity subtype, and early age and advanced disease at diagnosis are commonly reported in developing countries and do not fully explain the observed results. A longer follow-up is necessary to evaluate the influence of treatment standardization on the outcome of these children.

Anxiolytic effect of intra-amygdala injection of midazolam and 8-hydroxy-2-(di-n-propylamino)tetralin in the elevated T-maze

The effects of intra-amygdala injection of midazolam (20 nmol) and 8-hydroxy-2-(di-n-propylamino)tetralin (8-OH-DPAT; 8 and 16 nmol) were investigated in rats submitted to the elevated T-maze, a new animal model of anxiety. This test allows the measurement, in the same rat, of conditioned and unconditioned fear/anxiety responses. Both drugs impaired inhibitory avoidance of the open arms of the T-maze (task representing conditioned fear), indicating an anxiolytic effect, but did not change escape performance from one of the open arms (representing unconditioned fear). The results further implicate gamma-aminobutyric acid (GABA)/benzodiazepine and serotonergic systems within the basolateral/lateral amygdala in the modulation of conditioned anxiety responses.

Low socioeconomic status is a strong independent predictor of relapse in childhood acute lymphoblastic leukemia

The results of the treatment of acute lymphoblastic leukemia (ALL) in children depend not only on the biologic diversity of the leukemia cell, the multi-drug treatment schedule and the individual variability of drug metabolism, but also on the socioeconomic and cultural background of the leukemic child. Social and cultural disparity is very marked in underdeveloped countries and has been increasing in industrialized nations. The prognostic influences of these factors are poorly documented and sometimes mistakenly attributed to differences in ethnic origin. We have investigated in Brazil the relative impact of malnutrition and socioeconomic status on the outcome of ALL, adjusting for the known influence of biologic factors. Children with ALL (n = 167) treated with a Berlin-Frankfurt-Munster-based protocol were studied prospectively. At a median follow-up of 1623 days, the estimated probability of disease-free survival was 43 +/- 4%. The main cause for interruption of remission was bone-marrow relapse. Socioeconomic indicators of poverty (poor housing conditions, low per capita income and energy consumption) were significantly associated with a greater risk of relapse in univariate analysis. They were consolidated in a single index, socioeconomic status (SES), defined by the product of monthly per capita income times mean familial daily energy consumption. Other unfavorable findings included age, z score for the height for age at diagnosis (HAZ) below-1.28 and the z score for weight for age below-1.28. After adjustment in Cox's multivariate model, only HAZ and poor SES remained as predictive factors for relapse. Poor prognosis for leukemic children of low SES is just another indicator of social inequality.