Acute Pancreatitis Secondary to Severe Hypertriglyceridaemia in a Patient with Type 1a Glycogen Storage Disease: Emergent Use of Plasmapheresis.

Acute pancreatitis is a well-recognised complication of hypertriglyceridaemia. High serum triglycerides may develop in the autosomal recessive disorder glycogen storage disease (GSD). Plasmapheresis has been effective in reducing triglyceride levels in pancreatitis secondary to other conditions but not previously described in GSD. We describe a 16-year-old male with type 1a GSD who presented with severe abdominal pain, tachycardia and tachypnoea. Abdominal computed tomography (CT) demonstrated acute pancreatitis. Serum triglycerides were 91.8 mM. Despite intravenous fluids and morphine sulphate, he remained seriously ill, and plasmapheresis was therefore started. After daily plasma exchange for 6 days, triglyceride levels dropped to 5 mM. This was associated with a rapid resolution of pancreatitis. Plasmapheresis is effective in rapidly reducing hypertriglyceridaemia from numerous causes, including glycogen storage disease, and may facilitate recovery from acute pancreatitis.

Quantitative proteome profiling of respiratory virus-infected lung epithelial cells.

Respiratory virus infections are among the primary causes of morbidity and mortality in humans. Influenza virus, respiratory syncytial virus (RSV), parainfluenza (PIV) and human metapneumovirus (hMPV) are major causes of respiratory illness in humans. Especially young children and the elderly are susceptible to infections with these viruses. In this study we aim to gain detailed insight into the molecular pathogenesis of respiratory virus infections by studying the protein expression profiles of infected lung epithelial cells. A549 cells were exposed to a set of respiratory viruses [RSV, hMPV, PIV and Measles virus (MV)] using both live and UV-inactivated virus preparations. Cells were harvested at different time points after infection and processed for proteomics analysis by 2-dimensional difference gel electrophoresis. Samples derived from infected cells were compared to mock-infected cells to identify proteins that are differentially expressed due to infection. We show that RSV, hMPV, PIV3, and MV induced similar core host responses and that mainly proteins involved in defense against ER stress and apoptosis were affected which points towards an induction of apoptosis upon infection. By 2-D DIGE analyses we have gathered information on the induction of apoptosis by respiratory viruses in A549 cells.

Thirst perception and arginine vasopressin production in a kindred with an activating mutation of the type 2 vasopressin receptor: the pathophysiology of nephrogenic syndrome of inappropriate antidiuresis.

BACKGROUND: Activating mutations of the vasopressin receptor gene on the X chromosome cause the nephrogenic syndrome of inappropriate antidiuresis (NSIAD). We describe a male child who presented with persistent hyponatraemia and whose mother was also found to be hyponatraemic. She had learnt to avoid excess fluid consumption because of associated malaise. Both individuals had a subnormal ability to excrete a water load with mother also demonstrating a heightened sense of thirst at low serum osmolalities. RESULTS: Mother and child were found to have the previously characterised activating mutation (p.Arg137Cys) of the arginine vasopressin receptor type 2 gene (AVPR2), but had measurable levels of AVP when hyponatraemic. CONCLUSIONS: We conclude that female carriers of activating mutations of the vasopressin receptor are susceptible to hyponatraemia and therefore need to be provided with advice regarding fluid intake. An altered thirst perception may increase susceptibility to hyponatraemia. We confirm that the presence of measurable amounts of AVP in patients with hyponatraemia does not exclude the diagnosis of NSIAD.

Do systemic symptoms predict the risk of kidney scarring after urinary tract infection?

BACKGROUND AND AIMS: In the NICE guideline on childhood urinary tract infection (UTI), it is assumed that the presence or severity of systemic symptoms, especially fever, predicts for renal scarring, and different management is recommended accordingly. We aimed to test this hypothesis by retrospective case note analysis. DESIGN AND SUBJECTS: Notes of children aged under 5 years referred with a first UTI who were assessed for scarring were reviewed. MAIN OUTCOME CRITERIA: Ability to predict for single or multiple scarring from age, sex, fever, vomiting or anorexia or malaise, or need for hospitalisation, within the age bands used by NICE. RESULTS: There were 51 (65% girls) scarred and 140 (69% girls) unscarred children. Fever, systemic symptoms and hospitalisation were all commoner among younger children (<6 months vs 6 months-3 years vs >3 years; fever 0.67 vs 0.38 vs 0.38; systemic symptoms 0.78 vs 0.62 vs 0.43; hospitalisation 0.67 vs 0.29 vs 0.19; p<0.001 for all). Having vomiting, anorexia or malaise at presentation correlated weakly with single or multiple renal scarring (R(2) = 0.03; p = 0.02), but sex, age, fever or hospitalisation did not (p>0.5 for all). Sensitivity and specificity data, and plots of proportionate reduction of uncertainty showed that none of these variables was useful for predicting any scarring in children aged <3 years and that they were only weakly predictive in older children. CONCLUSIONS: Clinical signs at presentation in childhood UTI cannot be used to predict for mild or multiple scarring, and should not be used to guide management. NICE's recommendation to do so is not justified.

Thiopurine methyltransferase in acute lymphoblastic leukaemia: biochemical and molecular biological aspects.

Thiopurine S-methyltransferase (TPMT) is a cytosolic enzyme, catalysing S-methylation of aromatic and heterocyclic sulphhydryl compounds. TPMT activities and genotypes have been determined in patients with acute lymphoblastic leukaemia (ALL) and in control children. Median red blood cell (RBC) TPMT activity in ALL patients at diagnosis was significantly lower than in controls (median 11.5 pmol/10(7) RBC*hr; range 1.7-30.7; n = 191 vs. 14.6 pmol/10(7) RBC*hr; range 1.6-50.7; n = 140). This reduction of TPMT activity in ALL patients was not due to differences in the frequency of mutations in the TPMT gene. In concordance with other authors, we found a higher TPMT activity during maintenance treatment with 6-mercaptopurine (6MP) than at diagnosis and in controls. However, we observed that TPMT activity was already significantly increased after the induction therapy, before the patients received 6MP (median 17.5; range 3.9-40.3 pmol/10(7) RBC*hr; n = 139). In vitro experiments indicate that the early increase of TPMT activity during treatment may be explained by the use of antifolates, e.g., methotrexate and trimethoprim.

Real-time analysis of tyrosine hydroxylase gene expression: a sensitive and semiquantitative marker for minimal residual disease detection of neuroblastoma.

PURPOSE: The purpose of this study was to establish a sensitive and semiquantitative method for the detection of minimal residual disease of neuroblastoma, the most common solid tumor in childhood. EXPERIMENTAL DESIGN: Analysis was performed on a molecular level by reverse transcription-PCR using a new, real-time detection method. We measured two genes simultaneously, tyrosine hydroxylase (TH) as the target gene and glyceraldehyde-3-phosphate dehydrogenase as a reference gene, in blood and bone marrow samples at diagnosis and after follow-up from six patients with neuroblastoma, one patient with ganglioneuroma, and one patient with ganglioneuroblastoma. RESULTS: The sensitivity of the assay was 1:10(6) peripheral WBCs. Four patients with stage IV neuroblastoma and one patient with stage III neuroblastoma were scored positive. The other stage III patient and the other two patients with ganglioneuroma and ganglioneuroblastoma followed by acute lymphoblastic leukemia, respectively, were scored negative. Control bone marrow aspirates were also negative. The TH assay is more sensitive than immunohistochemical detection, and the results of the TH assay corresponded with the results of MYCN amplification. CONCLUSIONS: The described TH assay is specific, sensitive, and semiquantitative and can be used for the detection of neuroblastoma cell involvement in bone marrow and blood at diagnosis and during therapy. Furthermore, the TH assay is a possible prognostic marker for neuroblastoma.

Combination therapy in childhood leukaemia: in vitro studies of thiopurines and inhibitors of purine metabolism on apoptosis.

BACKGROUND: Methotrexate (MTX) followed by 6-mercaptopurine (6MP) is one of the best known combinations for the treatment of childhood acute lymphoblastic leukaemia. Tiazofurin (TF) and 6-thioguanine (TG) are also used as chemotherapy agents in the treatment of malignancies. We have examined the induction of apoptosis by combinations of these drugs to gain more insights into their efficacy in the treatment of malignancies. METHODS: The induction of apoptosis was examined in Molt-4, a human malignant acute lymphoblastic T-cell line. The cells were exposed to increasing drug concentrations at various exposure times. Annexin V/FITC and propidium iodide (PI) were used as markers for apoptosis and cell death. Annexin V/FITC positive and PI positive cells were detected by flow-cytometric analysis. RESULTS: Sequential 24-h exposure with MTX (0.005-0.02 micro mol) followed by 6MP (1-10 micro mol) and 24-h exposure with TF (5-20 micro mol) followed by TG (0.5-2 micro mol) showed a more than additive induction of apoptosis compared with single-drug exposure. Simultaneous administration of the drugs does not show an additive effect on apoptosis. CONCLUSIONS: The results of this study indicate that sequential administration of MTX before 6MP and of TF before TG may be essential for therapeutic success in the treatment of leukaemia.

Measurement of thiopurine S-methyltransferase activity in human blood samples based on high-performance liquid chromatography: reference values in erythrocytes from children.

BACKGROUND: Monitoring 6-thiopurine S-methyltransferase (TPMT; EC 2.1.1.67) activity is especially important when patients are treated with 6-thiopurine drugs, since severe bone marrow toxicity may be induced if patients have deficient TPMT activity. METHODS: We have developed a method based on high-performance liquid chromatography (HPLC) for the measurement of TPMT activity in various cell types: erythrocytes (RBC), human peripheral blood mononuclear cells (pMNC) and human malignant lymphoblasts (Molt-F4). The enzymatic activity is measured by the amount of 6-methylmercaptopurine formed, using 6-mercaptopurine (6MP) as substrate and S-adenosylmethionine as co-substrate. RESULTS: The K(m) values calculated for 6MP were 0.54 (RBC), 0.85 (pMNC) and 0.65 (Molt-F4 cells) mmol/L. The K(m) values for S-adenosylmethionine were 11.9 (RBC), 16.4 (pMNC) and 6.65 (Molt-F4 cells) micro mol/L. The assay variation was 8.2-17%. TPMT activity was determined in a control group of 103 children and young adults (44 female, 59 male). The values observed were (mean +/- standard deviation): female children and young adults, 15.1 +/- 4.8 pmol/10(7) cells per h (n = 44); male children and young adults, 15.8 +/- 6.4 pmol/10(7) cells per h (n = 59). No gender or age differences were found. CONCLUSION: The HPLC-based method enables the rapid screening of TPMT activities in large groups of patients treated with 6-thiopurines.

Selective renal embolisation for renovascular hypertension?

An 11 year old girl developed hypertensive encephalopathy and renal failure from reflux nephropathy. Resection of her shrunken left kidney did not control her hypertension. Two selective arterial embolisations of the scarred right lower pole produced only transient benefit, but a heminephrectomy gave good control. Embolisation may delay definitive treatment.

Oral health in children with renal disease.

Thirty-eight children (aged 2-16 years) attending a regional kidney unit had a full clinical and radiological dental examination. Twenty had previously undergone a renal transplant, 11 had chronic renal failure and 7 had other renal diseases. Periodontal disease was uncommon The presence of gingival hyperplasia (gum overgrowth), as recorded in 22 of the children, did not show any relationship with the use of immunosuppressant therapy. However, gingival overgrowth was so excessive in 2 patients that surgical removal was required. The prevalence of dental caries was low. Enamel defects were common, and of an unusual pattern, with a much higher prevalence of diffuse opacities and enamel hypoplasia than in the normal child population, 83% and 22%, respectively. This increased prevalence is probably due to disordered calcium and phosphate metabolism. The prevalence of these defects may reflect an early onset of renal disease, since there were a number of very young children in the programme. Dental and medical care should be closely integrated for children with renal disease to avoid the undesirable dental sequelae of, in particular, gingival overgrowth, carcinoma and enamel hypoplasia.

Does positive pressure ventilation increase arginine vasopressin in preterm neonates?

AIM: To examine the effect of intermittent positive pressure ventilation (IPPV) on plasma arginine vasopressin concentration (pAVP) in preterm neonates. METHODS: Thirty five neonates were classified, at the time of blood sampling, into three groups: unstable ventilated; stable ventilated; and stable non-ventilated. A modification of an extraction method for pAVP was developed for use in studies on very small babies, and sampling methods were compared. RESULTS: The pAVP (median, range) was similar in the ventilated (1.85 pmol/l, 0.5 to 3.4) and non-ventilated (2.0, 0.5 to 2.6) stable babies, but was significantly higher (5.7, 1.1 to 25) in the unstable group. There was an inverse correlation between systolic blood pressure and pAVP concentration. CONCLUSIONS: This study shows that in preterm neonates pAVP concentration is affected by the clinical condition and blood pressure, but not by treatment with IPPV.

Central-peripheral temperature difference, blood pressure, and arginine vasopressin in preterm neonates undergoing volume expansion.

AIM: To examine the effect of intravascular volume expansion for the treatment of hypovolaemia in sick preterm neonates. METHODS: An intravenous infusion of 20 ml per kg of 4.5% albumin was given to 14 preterm neonates. The effects on systolic blood pressure, central peripheral temperature difference (c-pT), and plasma arginine vasopressin concentration (pAVP) were measured. RESULTS: Thirteen babies showed a rise in systolic blood pressure. The six babies with the highest initial values of pAVP and c-pT showed a fall in both of these after infusion. The babies with lower initial pAVP (below 4 pmol/l) showed either a rise (two) or no change (six) after albumin infusion. There was a significant correlation between c-pT and log pAVP before (r2 = 0.61; p < 0.05) and after infusion (r2 = 0.45; p < 0.05). CONCLUSIONS: Plasma AVP concentration is related to c-pT in unwell preterm newborns. This study suggests that clinical assessment of hypovolaemia in preterm newborns is poor and could be improved by using c-pT.

New renal scarring in children who at age 3 and 4 years had had normal scans with dimercaptosuccinic acid: follow up study.

OBJECTIVE: To determine up to what age children remain at risk of developing a new renal scar from a urinary tract infection. DESIGN: Follow up study. Families of children who had normal ultrasound scans and scanning with dimercaptosuccinic acid (DMSA) after referral with a urinary tract infection when aged 3 (209) or 4 (220) were invited to bring the children for repeat scans 2-11 years later. A history of infections since the original scan was obtained for children not having a repeat scan. SETTING: Teaching hospital. SUBJECTS: Children from three health districts in whom a normal scan had been obtained at age 3-4 years in 1985-1992 because of a urinary tract infection. MAIN OUTCOME MEASURE: Frequency of new renal scars in each age group. RESULTS: In each group, about 97% of children either had repeat scanning (over 80%) or were confidently believed by their general practitioner or parent not to have had another urinary infection. The rate of further infections since the original scan was similar in the 3 and 4 year old groups (48/176 (27%)) and 55/179 (31%)). Few children in either group known to have had further urinary infections did not have repeat scanning (3/209 (1.4%) and 4/220 (1.8%)). In the 3 year old group, 2.4% (5/209) had one or more new kidney scars at repeat scanning (one sided 95% confidence interval up to 5.0%), whereas none of the 4 year olds did (one sided 95% confidence interval up to 1.4%). The children who developed scars were all aged under 3.4 years when scanned originally. CONCLUSIONS: Children with a urinary tract infection but unscarred kidneys after the third birthday have about a 1 in 40 risk of developing a scar subsequently, but after the fourth birthday the risk is either very low or zero. Thus the need for urinary surveillance is much reduced in a large number of children.

Screening of newborn babies for familial ureteric reflux.

BACKGROUND: Vesicoureteric reflux (VUR) is not usually diagnosed until it is complicated by urinary infection. Prevention probably requires diagnosis in a newborn baby before urinary infection occurs because the peak incidence for infection is in early infancy. VUR is a familial disorder. We sought to find out whether an at-risk group of newborn babies could be identified on the basis of the parents' family history. METHODS: Over a 3-year period, pregnant women attending the antenatal clinics of three hospitals in the northeast of England were screened for evidence of urinary-tract disease in themselves or their families with a view to eliciting a history of VUR. When a woman, her partner, or a member of either family had a definite (by cystography records) or probable positive history, we recruited the mother to our study. Renal ultrasonography and cystography were done on the newborn babies soon after delivery, and a dimercaptosuccinic acid (DMSA) radioisotope scan at 3 months was done on those with VUR. FINDINGS: The estimated number of deliveries during the study period was 34,555; 20,891 women were screened; and 211 were recruited and delivered. The index cases were identified from a wide range of family relationships, though over half consisted of mothers and siblings, 19 babies had more than one index case and in 21 families there was one index for more than one baby or a link between families. Cystography was carried out on 186 newborn babies; 38 (20.4%) had VUR. The proportion of newborn babies with VUR among linked index families was 31%. Mothers and siblings amounted to 71% of the index cases for newborn babies with VUR. The difference between confirmed and assumed index cases in VUR prediction was not significant. The female/male sex ratio among index cases was more than 4, but among newborn babies with VUR it was 1.5. Renal ultrasound showed no correlation with VUR, and all DMSA scans but one were normal. No newborn baby developed complications resulting from cystography. INTERPRETATION: The screening of pregnant women for familial VUR is worthwhile because the frequency of VUR among the newborn babies of those with such a history is significantly higher than in the general population (frequency of VUR 1-2%), particularly if the family history involves more than one member, or more than one generation.