Severe transient hyperinsulinaemic hypoglycaemia: two neonates without predisposing factors and a review of the literature

We report on transient hyperinsulinism (HI), presenting as severe congenital HI, in two neonates born without intrauterine growth restriction, maternal diabetes, perinatal asphyxia or Rhesus/platelet isoimmunisation. The neonates developed early (<6 h of life), symptomatic, non-ketotic hypoglycaemia (0-0.66 mmol/l), associated with elevated insulin levels (40-200 mU/l), and required high glucose infusion rates (22-24 mg/kg per min) to maintain normoglycaemia. However, both babies were diazoxide-sensitive and did not require glucose infusions beyond 2 weeks of life. Neither neonate had elevated serum ammonia levels or evidence of a metabolic disorder.

CONCLUSION

Transient hyperinsulinism can occur in newborns delivered uneventfully without significant perinatal complications. The unusual sensitivity to medical treatment in these cases of neonatal-onset hyperinsulinaemic hypoglycaemia underscores the importance of careful medical management of severe congenital hyperinsulinism. Careful consideration of the indication and if necessary, timing and extent of pancreatectomy is required, while maintaining euglycaemia to protect the developing brain.

Secondary myelodysplastic syndrome and leukemia following 131I-metaiodobenzylguanidine therapy for relapsed neuroblastoma

PURPOSE

To describe three patients with secondary leukemia after treatment with 131I-metaiodobenzylguanidine (MIBG) for neuroblastoma.

METHODS

Of 95 children with refractory neuroblastoma treated with 131I-MIBG at UCSF, 3 have been identified with secondary myelodysplasia/leukemia. The case records and bone marrow results were reviewed, along with a review of the literature.

RESULTS

Three patients developed secondary myelodysplasia/leukemia, at 7, 11, and 12 months following 131I-MIBG therapy. Cytogenetic abnormalities included -7q/-5, -7/+2q37, -11 and +12. Three additional cases were found in literature review of 509 reported patients treated with 131I-MIBG for neuroblastoma.

CONCLUSIONS

Therapy with 131I-MIBG may contribute to the risk of secondary leukemia in patients who have received intensive chemotherapy, thought the risk of this complication is far lower than the risk of disease progression. Further monitoring for this complication is indicated.

Lympho-hemopoietic malignancies in India

Available information on lympho-hemopoietic malignancies in India is presented. The incidence of most cancers, including multiple myeloma, lymphomas, and leukemias, is lower compared to that in the West; chronic myelogenous leukemia, however, is higher and the incidence of non-Hodgkin's lymphoma (NHL) is rising. Most cancers occur at a younger age. Higher frequencies of mixed-cellularity Hodgkin's disease, diffuse large-cell NHL and T cell acute lymphoblastic leukemia are noted. Most patients present in advanced stages and have poorer prognostic factors. Treatment results are comparable if stagewise distribution and poor prognostic factors are taken into account.

Randomized study comparing 4'-epi-doxorubicin (epirubicin) versus doxorubicin as a part of induction treatment in adult acute lymphoblastic leukemia

Doxorubicin or daunorubicin are routinely used to induce remission in acute lymphoblastic leukemia (ALL). Efficacy of epirubicin (an analog of doxorubicin), however, has not been adequately evaluated in ALL management. This randomized study was undertaken to compare the relative efficacy of epirubicin vs. doxorubicin as part of induction chemotherapy in adult ALL. Between January 1990 and June 1998, 79 previously untreated adult ALL patients (age 11-55 years, median 20 years) were randomized to receive either doxorubicin (Group A, n = 39) or epirubicin (Group B, n = 40) as a part of induction therapy. Vincristine and prednisolone were common in each group. The induction treatment was followed by identical consolidation and maintenance therapy. The two groups were compared as regards pretherapy clinical and laboratory parameters, dose intensity of therapy, therapeutic efficacy, myelotoxicity, and survival. Epirubicin was as effective as doxorubicin in terms of complete remission rate (80% vs. 78.3%; P = 0.87) and relapse rate (57.1% vs. 51.7%; P = 0.68). Five-year overall survival (30% vs. 30%, P = 0.98) and disease-free survival (40% vs. 39%, P = 0.92) at median follow-up of 68 months was also similar in the two groups. The incidence of Grade 4 myelotoxicity was comparable in the two groups. Patients 20 years of age or less had better CR rates (90% vs. 65%; P = 0.011) and median overall survival (39 vs. 11 months; P = 0.008) compared to those who were older. From this study epirubicin appears as effective as doxorubicin as part of induction therapy for adult ALL. However, the results need to be validated on the basis of immunophenotype and cytogenetic prognostic characterization.

Severe congenital lead poisoning in a preterm infant due to a herbal remedy

A preterm infant born to a woman with chronic lead poisoning was found to have the highest blood lead level recorded for a surviving neonate. Parenteral calcium disodium edetate, but not oral succimer, was effective in reducing the infant's lead burden in the neonatal period. An exposure assessment revealed the mother's long-term ingestion of lead-contaminated herbal tablets as the source.

Evaluating congenital spine deformities for intraspinal anomalies with magnetic resonance imaging

SUMMARY

The incidence of intraspinal abnormalities associated with congenital spinal anomalies as detected by magnetic resonance imaging (MRI) is becoming better defined. In this study, 41 nonrandomized children with congenital spinal deformities (excluding myelomeningocele) who underwent complete MR evaluation were reviewed. Of the 41 congenital spinal deformities, 37 demonstrated congenital scoliosis, with failure of formation in 19, failure of segmentation in 4, and mixed defects in 14. The remaining four deformities were cases of congenital kyphosis. Thirteen patients with congenital spine anomalies were noted to have intraspinal abnormalities identified by MRI: tethered cord in 12 patients, syringomyelia in 3 patients, and diastematomyelia in 5 patients. Of the 12 patients with tethered cord, 2 patients had neurologic deficits. Urorectal anomaly was one of the most common associated findings (15%). Considering an incidence of intraspinal anomalies of 31% and as clinical manifestations may not be initially detectable, MRI is recommended in patients with congenital spinal deformity as part of the initial evaluation even in the absence of clinical findings.

Determinants of outcome after intensified therapy of childhood lymphoblastic leukaemia: results from Medical Research Council United Kingdom acute lymphoblastic leukaemia XI protocol

The single most important prognostic determinant in childhood acute lymphoblastic leukaemia (ALL) is effective therapy and changes in therapy may influence the significance of other risk factors. The effect of intensified therapy on the importance of currently recognized phenotypic and genotypic determinants of outcome was assessed in 2090 children enrolled on the Medical Research Council United Kingdom acute lymphoblastic leukaemia XI (MRC UKALL XI) protocol. Treatment allocation was not determined by risk factors. Multivariate analysis confirmed the dominant influence on prognosis of age, sex and presenting white cell count (WCC). After allowing for these features, blast karyotype, d 8 marrow blast percentage and remission status at the end of induction therapy were the only remaining significant predictors of outcome. Organomegaly, haemoglobin concentration, French--American--British type, body mass index, presence of central nervous system disease at diagnosis, immunophenotype and presence of TEL/AML1 fusion gene (examined in a subset of 659 patients) either had no significant effect on outcome or were significant only in univariate analysis. Among karyotype abnormalities with an independent influence on prognosis, high hyperdiploidy (> 50 chromosomes) was shown to be favourable, whereas near haploidy (23--29 chromosomes), presence of the Philadelphia chromosome, t(4;11) and abnormalities affecting the short arm of chromosome 9 [abn (9p)] were adverse risk factors. Early responders to therapy, determined by residual marrow infiltration after 8 d of induction therapy, had a good outcome, while the small proportion of patients who did not achieve a complete remission by the end of induction therapy had a poor outcome. A third block of late intensification was shown to improve event-free survival by 8% at 5 years. The effect of these risk factors was not significantly different between those randomized to the third intensification block and those not randomized to a third block.

DNase protection analysis of retrovirus integrase at the viral DNA ends for full-site integration in vitro

Retrovirus intasomes purified from virus-infected cells contain the linear viral DNA genome and integrase (IN). Intasomes are capable of integrating the DNA termini in a concerted fashion into exogenous target DNA (full site), mimicking integration in vivo. Molecular insights into the organization of avian myeloblastosis virus IN at the viral DNA ends were gained by reconstituting nucleoprotein complexes possessing intasome characteristics. Assembly of IN-4.5-kbp donor complexes capable of efficient full-site integration appears cooperative and is dependent on time, temperature, and protein concentration. DNase I footprint analysis of assembled IN-donor complexes capable of full-site integration shows that wild-type U3 and other donors containing gain-of-function attachment site sequences are specifically protected by IN at low concentrations (<20 nM) with a defined outer boundary mapping ~20 nucleotides from the ends. A donor containing mutations in the attachment site simultaneously eliminated full-site integration and DNase I protection by IN. Coupling of wild-type U5 ends with wild-type U3 ends for full-site integration shows binding by IN at low concentrations probably occurs only at the very terminal nucleotides (<10 bp) on U5. The results suggest that assembly requires a defined number of avian IN subunits at each viral DNA end. Among several possibilities, IN may bind asymmetrically to the U3 and U5 ends for full-site integration in vitro.

Benefit of intensified treatment for all children with acute lymphoblastic leukaemia: results from MRC UKALL XI and MRC ALL97 randomised trials. UK Medical Research Council's Working Party on Childhood Leukaemia

Treatment of children with acute lymphoblastic leukaemia (ALL) aims to cure all patients with as little toxicity as possible and, if possible, to restrict further intensification of chemotherapy to patients with an increased risk of relapse. However in Medical Research Council (MRC) trial UKALL X two short myeloablative blocks of intensification therapy given at weeks 5 and 20 were of benefit to children in all risk groups. The successor trials, MRC UKALL XI and MRC ALL97, tested whether further intensification would continue to benefit all patients by randomising them to receive, or not, an extended third intensification block at week 35. After a median follow-up of 4 years (range 5 months to 8 years), 5 year projected event-free survival was superior at 68% for the 894 patients allocated a third intensification compared with 60% for the 887 patients who did not receive one (odds ratio 0.75, 95% CI 0.63-0.90, 2P = 0.002). This difference was almost entirely due to a reduced incidence of bone marrow relapses in the third intensification arm (140 of 891 in the third intensification arm vs. 171 of 883 in the no third intensification, 2P = 0.02). Subgroup analysis suggests benefit of the third intensification for all risk categories. Overall survival to date is no different in the two arms, indicating that a greater proportion of those not receiving a third intensification arm and subsequently relapsing can be salvaged. These results indicate that there is benefit of additional intensification for all risk subgroups of childhood ALL.

Radiofrequency ablation of atrial tachycardia originating from the triangle of Koch

Atrial tachycardia (AT) originating in the triangle of Koch is reported rarely and presents a potential risk of atrioventricular (AV) block during radiofrequency (RF) catheter ablation. Eight patients with AT in the triangle of Koch undergoing RF ablation are presented. There were five women and three men, ranging in age from 32 to 74 years. One patient had bicuspid aortic valve disease, and the other seven patients had no structural heart disease. At electrophysiological study, AT was inducible in all eight patients. In one patient, AV nodal re-entrant tachycardia was also inducible. The site of AT was located by recording the earliest atrial activation during AT and successful RF ablation. Fluoroscopy confirmed the corresponding site to the region of the triangle of Koch. The earliest atrial activation was 35+/-9 ms before the surface P wave, and was recorded at the apex of the triangle of Koch near the bundle of His in six patients and midway between the bundle of His and coronary sinus os in two patients. At the successful RF application site, His potential was not recorded in any patient. The mean AV ratio was 5:1 (range 1:1 to 12:1). RF ablation at the successful site resulted in accelerated junctional rhythm in four of the eight patients and successfully terminated AT in all eight patients, with first-degree AV block in one patient. In conclusion, AT from the triangle of Koch is a distinct entity and RF ablation can be successfully performed; however, a potential risk of AV block remains.

Comparison of efficacy of intravenous diltiazem and esmolol in terminating supraventricular tachycardia

OBJECTIVE

Paroxysmal supraventricular tachycardia (PSVT) can be effectively terminated by the intravenous administration of adenosine or verapamil. However adenosine is expensive and injectable verapamil currently is scarcely available. While intravenous diltiazem has been shown to be useful for terminating PSVT, the efficacy of esmolol in this regard has not been evaluated previously. Hence these latter two drugs were studied for their efficacy in terminating PSVT.

METHODS

A prospective, randomised, crossover study was undertaken in patients presenting with hemodynamically tolerated PSVT to the ICCU. While 50 patients had been planned for the trial, the study had to be prematurely terminated after 32 patients had been enrolled due to the marked superiority of diltiazem. Two sequential doses with a 5 minute interval of either drug were administered before crossover. Diltiazem was given in a dose of 0.25 mg/kg while the esmolol dose was 0.5 mg/kg.

RESULTS

Diltiazem terminated PSVT in all the 16 patients in whom it was given as the first drug. The 12 patients who did not respond to esmolol were also effectively treated with diltiazem. Thus totally 28/28 patients responded to diltiazem while only 4/16 patients responded to esmolol (p < 0.001). Of the 28 patients who responded to diltiazem, in 13 patients the second bolus of diltiazem worked after the first one had failed. No significant adverse effects were seen.

CONCLUSION

Intravenous diltiazem is highly effective and safe for terminating PSVT. When the first bolus is ineffective, the second bolus given after 5 minutes usually succeeds. Esmolol in the dose of 0.5 mg/kg has poor efficacy for terminating PSVT, even when 2 boluses are administered.

Central venous catheter-associated thrombosis in severe haemophilia

Significant subclavian vein thromboses associated with indwelling fully implanted (port-a-cath) devices are described in two boys with severe haemophilia A and factor VIII inhibitors. Investigations were prompted by prominent chest wall veins in one case, whereas the thrombosis was a chance finding in the other case during investigation of mechanical dislocation of the catheter tubing. Extensive collateral venous circulations were demonstrated by venography in both instances indicating that the thrombus had been present for some time. Possible contributing factors to the thromboses included desensitization therapy (both patients), high-dose FEIBA (in one patient) and use of lower doses of heparin for line flush than that recommended by some authors. Neither patient had a familial or non-familial predisposition to thrombosis.