Clonidine and glucagon stimulation for testing growth hormone secretion in children and adolescents: can we make it with fewer samples?

BACKGROUND: Our aim was to retrospectively evaluate the possibility to reduce the number of GH analyses during clonidine and glucagon tests without compromising accuracy. SUBJECTS AND METHODS: Two hundred and forty-five tests were performed in a total of 188 children and adolescents with a mean age of 9.93 ± 2.88 yr in a single center during the last 5 yr. RESULTS: Ninety-one out of 158 (57.59%) clonidine tests and 47/87 (54.02%) glucagon tests had at least one sample >10 µg/l (negative). For clonidine tests, not measuring GH at 30 min would have resulted in only one negative test missed (0.63% false positive result), whereas not measuring GH both at 0 and 30 min would have increased the false positive percentage to 2.53%. Ending clonidine tests at 90 min would have resulted in 7 negative tests missed (4.43% false positive results). For glucagon tests, more than half of the tests peaked at 120 min (56.32%). Skipping sampling at 0, 60 and 180 min provided a false positive rate of 5.75%. CONCLUSIONS: For clonidine tests we can omit blood sampling at time points 0 and 30 min without significantly compromising accuracy.

Ethylmalonic encephalopathy: clinical and biochemical observations.

Ethylmalonic encephalopathy (EE) is a rare, recently defined inborn error of metabolism which affects the brain, gastrointestinal system and peripheral blood vessels and is characterized by a unique constellation of clinical and biochemical features. A 7-month-old male, who presented with psychomotor retardation, chronic diarrhea and relapsing petechiae is described with the objective of highlighting the biochemical and neuroradiological features of this disorder as well as the effect of high-dose riboflavin therapy. Urinary organic acid analysis revealed markedly increased excretion of ethylmalonic acid, isobutyrylglycine, 2-methylbutyrylglycine and isovalerylglycine. Acylcarnitine analysis in dried blood spots showed increased butyrylcarnitine. Short-chain acyl-CoA dehydrogenase (SCAD) activity in muscle was normal as were mitochondrial OXPHOS enzyme activities in cultured skin fibroblasts. In skeletal muscle the catalytic activity of complex II was decreased. Brain MRI revealed bilateral and symmetrical atrophy in the fronto-temporal areas, massive enlargement of the subarachnoid spaces and hyperdensities on T (2) sequences of the basal ganglia. Mutation analysis of the ETHE1 gene demonstrated homozygosity for the Arg163Gly mutation, confirming the diagnosis of EE at a molecular level. On repeat MRI, a significant deterioration was seen, correlating well with the clinical deterioration of the patient.

A pseudo-outbreak of human A/H5N1 infections in Greece and its public health implications.

The recent wide geographic spread of the highly pathogenic avian influenza A/H5N1 virus has important public health implications. Several wild migratory birds were confirmed to be infected with avian influenza A/H5N1 in Greece in February and March 2006. The aim of this paper is to report data from potential H5N1 human cases that presented to local hospitals during this period with a respiratory infection and expressing concern about exposure to avian influenza. A case-control investigation was conducted that included case identification with the use of a structured definition, review of epidemiological and clinical characteristics and molecular testing for avian influenza A/H5N1. The setting was the entire country of Greece during February and March 2006. The main outcomes were rates of possible cases (meeting both a clinical and an epidemiological criterion) and clinical or epidemiological characteristics differentiating them from potential cases that met either one of the criteria of a possible case, but not both. Twenty six potential patients (81% of whom met a clinical criterion, and 39% of whom met an epidemiological criterion) presented and most (85%) were admitted in local hospitals during the period of interest. The majority of cases (85%) were observed in northern Greece where most of the confirmed A/H5N1 avian cases were documented. Five of the 26 evaluated patients met the definition of a possible case. These clustered within the early period of confirmed A/H5N1 cases in wild migratory birds (P=0.05). Molecular testing was negative for all possible cases. Application of a revised case definition constructed according to newer European Union guidance resulted in the exclusion of two possible cases. Several potential A/H5N1 human cases were recently identified in Greece. Both the timing of identification and the geographical location of potential cases suggest an increased awareness on the part of the general public, as well as poor interpretation of the case definition by the clinicians.

Craniofacial osteotomies to facilitate resection of large tumours of the anterior skull base.

Large tumours of the anterior cranial fossa can be a major challenge to the neurosurgeon or the maxillofacial surgeon. However, skull base approaches facilitate their resection. We describe our experience with the extended subfrontal approach in treating tumours of the anterior cranial base. This approach was performed on 29 patients with large tumours of the anterior skull base. The final outcome in all 29 patients was favourable in terms of total resection of the tumour with minimal subsequent neurological deficit. Two patients developed transient oedema of the frontal lobes without persistent neurological sequelae. Another patient developed a postoperative cerebrospinal fluid fistula that was successfully repaired. The patients were followed for a period ranging from 6 to 28 months. There was no recurrence. The operative technique is described. En bloc removal of the roofs of the orbits and part of the anterior cranial fossa permits wide exposure of the lesion with minimal brain retraction. Reconstruction of the anterior cranial base should be meticulous to avoid cerebrospinal fluid leaks and subsequent meningitis. Loss of smell is a sequel to this approach. The possible risks and some important technical details are highlighted.