Diagnostic efficacy of activated partial thromboplastin time waveform and procalcitonin analysis in pediatric meningococcal sepsis.

OBJECTIVE: A biphasic activated partial thromboplastin time waveform predicts sepsis and disseminated intravascular coagulation in adults. This has not been previously investigated in children. Our aim is to ascertain whether there are changes in the activated partial thromboplastin time waveform in children with meningococcal disease and to compare its diagnostic use with procalcitonin. SETTING: Alder Hey Children's National Health Service Foundation Trust, Liverpool, UK. PATIENTS: Thirty-six children admitted to the hospital for the treatment of suspected meningococcal disease had activated partial thromboplastin time waveform and procalcitonin analysis performed at admission. The light transmittance level at 18 secs was used to quantitate the waveform. Severity of disease was assessed using the Glasgow Meningococcal Septicaemia Prognostic Score, Pediatric Risk of Mortality III score, and the Pediatric Logistic Organ Dysfunction score. MEASUREMENTS AND MAIN RESULTS: Twenty-four children had proven meningococcal disease, 12 had a presumed viral illness, and 20 control subjects were recruited. Transmittance level at 18 secs was lower in children with meningococcal disease and those with a viral illness (p < .0001) and control subjects (p < .0005). Sensitivity and specificity was 0.91 and 0.96 for transmittance level at 18 secs and 0.92 and 1 for procalcitonin in identifying meningococcal disease. There was a significant difference in procalcitonin between children with meningococcal disease and those with a viral illness and control subjects (p < .0005). A negative correlation was found between transmittance level at 18 secs and length of hospital stay (p < .0001), C-reactive protein (p < .0001), procalcitonin (p < .0001), Glasgow Meningococcal Septicaemia Prognostic Score (p < .01), Pediatric Risk of Mortality III score (p < .0001), and Pediatric Logistic Organ Dysfunction score score (p < .0001). CONCLUSION: The activated partial thromboplastin time waveform is abnormal in children with meningococcal disease and may be a useful adjunct in the diagnosis and management of sepsis in children.

Central venous catheter infection with Bacillus pumilus in an immunocompetent child: a case report.

BACKGROUND: Bacillus organisms are common laboratory contaminants. The majority of Bacillus bacteraemias are transient and not clinically significant. Clinically significant infection due to Bacillus species is rare and mostly due to Bacillus cereus infections in immuno-compromised hosts. CASE PRESENTATION: We report a case of central venous catheter infection with Bacillus pumilus in an immunocompetent child with tufting enteropathy on long-term parenteral nutrition (PN). There were three episodes of central venous catheter infection with Bacillus pumilus in three months. Despite adequate and appropriate use of intravenous antibiotics, the infection failed to clear resulting in the need for removal of the catheter for complete cure. CONCLUSION: Bacillus species can cause clinically significant central venous catheter infection, even in an immunocompetent host. Despite adequate antibiotic treatment, the central venous catheter may need removal for complete cure.

Ceramide-induced killing of normal and malignant human lymphocytes is by a non-apoptotic mechanism.

Synthetic ceramides induce apoptotic death of Jurkat and HL60 leukaemia cell lines. By contrast we show here that ceramide induces non-apoptotic killing of malignant cells from patients with B-chronic lymphocytic leukaemia (B-CLL) and of normal B lymphocytes. The protein phosphatase inhibitor okadaic acid readily induces apoptosis of B-CLL cells, indicating that this death pathway is fully functional in these cells. The ability of ceramide to activate the apoptotic protease caspase 3 in HL60 cells but not in B-CLL cells, as well as the lack of correlation of ceramide-mediated killing of different B-CLL isolates with expression of the apoptosis-regulating proteins bcl-2 and bax reinforce the conclusion that ceramide killing of B-CLL cells is by a non-apoptotic mechanism. Fludarabine treatment or gamma-irradiation of B-CLL cells resulted in ceramide elevation and in killing by both apoptotic and non-apoptotic mechanisms, suggesting that a ceramide-triggered non-apoptotic mechanism may play a role in the killing of these cells. Therefore, the results here show that ceramide can induce either apoptotic or non-apoptotic death, depending on the cellular context. The inability of synthetic dihydroceramide to kill B-CLL cells or normal B lymphocytes suggests that non-apoptotic killing by ceramide is via interaction with a specific, but unidentified, cellular target.

Herbimycin A accelerates the induction of apoptosis following etoposide treatment or gamma-irradiation of bcr/abl-positive leukaemia cells.

Philadelphia chromosome (Ph)-positive leukaemia cells express the chimeric bcr/abl oncoprotein, whose deregulated protein tyrosine kinase (PTK) activity antagonizes the induction of apoptosis by DNA damaging agents. Treatment of Ph-positive K562, TOM 1 and KCL-22 cells with etoposide for 2d induced cytosolic vacuolation, but not nuclear condensation or DNA fragmentation. The bcr/abl kinase-selective inhibitor herbimycin A increased the induction of nuclear apoptosis by etoposide or gamma-radiation. The concentration of herbimycin required to synergize with etoposide was similar to that required to decrease the level of tyrosine phosphorylated proteins or of the protein tyrosine kinase activity of anti-abl immune complexes in K562 cells. The ability of herbimycin A to sensitize K562, TOM 1 or KCL-22 cells to apoptosis induction correlated with its ability to decrease the cellular content of phosphotyrosyl proteins in these Philadelphia-positive lines. Enhancement of nuclear apoptosis by herbimycin was not attributable to downregulation of the bcl-2 or bcl-XL anti-apoptotic proteins. In contrast, herbimycin protected Philadelphia-negative HL60 cells from apoptosis induction by etoposide and did not affect killing of NC37 and CEM cells. The data suggest that the induction of apoptosis is blocked in cells expressing the bcr/abl oncoprotein and that herbimycin A increases induction of programmed cell death following DNA damage. Selective PTK inhibitors may therefore be of value in securing the genetic death of Ph-positive leukaemia cells.

Kinking of RNA helices by bulged bases, and the structure of the human immunodeficiency virus transactivator response element.

We have used gel electrophoresis to show that the pyrimidine bulge of the HIV-1 TAR sequence causes a local bending of the helical axis. The TAR bulge caused a retardation in electrophoretic mobility in polyacrylamide gels. When this was placed adjacent to an additional bulged sequence in a linear RNA fragment, the mobility of the molecule varied sinusoidally with the spacing between the two bulges. Electrophoretic mobilities suggested that the TAR sequence context of the pyrimidine bulge causes a greater degree of axial kinking than in an equivalent randomly chosen sequence. Experiments in which an A5 bulge was progressively opposed by adenine bases inserted in the opposite strand showed that even a single opposed adenine markedly reduced electrophoretic mobility, i.e. axial bending, and two adenine bases reduced the mobility virtually to that of a normal duplex. We suggest that the pronounced kinking resulting from an unopposed bulge provides a particularly recognizable feature in RNA, and that this is the basis of the interaction between the HIV Tat protein and the TAR sequence.

Co-ordinated downregulation of bcl-2 and bax expression during granulocytic and macrophage-like differentiation of the HL60 promyelocytic leukaemia cell line.

The bcl-2 protein suppresses apoptosis and the bax protein opposes the cytoprotective effect of bcl-2. A decrease in bcl-2 levels has been implicated in the induction of apoptosis during the terminal differentiation of HL60 myeloid leukaemia cells. We show here that bax protein also declined with a time course similar to the downregulation of bcl-2 following treatment of HL60 with phorbol myristate acetate (PMA), dimethyl sulphoxide (DMSO) or retinoic acid (RA). Decreased bcl-2 protein expression in induced cells was associated with down-regulation of its mRNA. By contrast, the decrease in bax occurred by a post-transcriptional mechanism. Co-ordinate downregulation of bcl-2 and bax proteins may fine-tune the induction of apoptosis during cellular differentiation.

Okadaic acid-induced apoptosis of HL60 leukemia cells is preceded by destabilization of bcl-2 mRNA and downregulation of bcl-2 protein.

We have studied the actions of the protein phosphatase inhibitor okadaic acid (OA) on the expression of bcl-2 in HL60 human leukemia cells. OA induced downregulation of bcl-2 mRNA and protein prior to the induction of apoptosis. Downregulation of bcl-2 mRNA levels did not result from actions of OA on the bcl-2 upstream negative response element. Nuclear run-off analyses confirmed that OA did not affect bcl-2 gene transcription. However, OA caused a rapid increase in the rate of degradation of bcl-2 mRNA. Therefore, OA induces down-regulation of bcl-2 expression via destabilization of its transcript. The constitutive action of an OA-sensitive protein phosphatase may therefore maintain HL60 cell survival by blocking bcl-2 mRNA degradation.

Increasing microbiological confirmation and changing epidemiology of meningococcal disease on Merseyside, England.

OBJECTIVES: To determine, for the last 5 years in children on Merseyside with clinical meningococcal disease (MCD), the impact on diagnostic yield of newer bacteriologic methods; bacterial antigen detection (AD) and polymerase chain reaction (PCR). METHODS: Prospective data collection at Royal Liverpool Children's Hospital over two epochs: 1 September 1992 to 30 April 1994 (epoch A, n = 126) and 17 November 1997 to 15 September 1998 (epoch B, n = 85). RESULTS: Epoch A was compared with epoch B. Diagnosis was confirmed by detection of meningococci in 78 of 126 (61.9%) versus 64 of 85 (75.3%, P = 0.04), but with a significantly lower rate of positive blood and cerebrospinal fluid culture in the later epoch. The proportion of cases receiving penicillin pretreatment was unchanged at 32%, but the proportion undergoing lumbar puncture decreased significantly. Median ages were higher in epoch B: 1.7 years versus 2.49 years (P = 0.013, Mann-Whitney). There was a significant increase in the proportion of cases due to serogroup C (14/78 (18%) versus 30/64 (46.9%), P = 0.001). CONCLUSIONS: Culture detection of meningococci from children with MCD has reduced, as less lumbar punctures are done. However, improved diagnosis by PCR and AD has increased microbiological confirmation overall. Serogroup C disease and the median age of cases continue to rise.

Recognition, treatment and complications of meningococcal disease.

Meningococcal disease remains a major cause of death in young children. A decrease in mortality requires recognition and treatment of the disease at a number of stages in the illness. Life-threatening meningococcal disease usually presents as septicaemia rather than meningitis. The cardinal feature of meningococcal septicaemia is the purpuric rash. Many parents recognise the rash and seek medical advice because of it. When primary care physicians recognise the rash, the administration of parenteral penicillin may decrease mortality. However, antibacterials are not given promptly if there is no rash or if the disease presents in an atypical form. In hospital, antibacterial therapy with a third-generation cephalosporin should be given. Disease severity needs to be assessed by a valid method, such as the Glasgow Meningococcal Septicaemia Prognostic Score (GMSPS). This can identify those patients who need intensive care and/or might benefit from new therapies. The 2 life-threatening complications are septic shock and meningoencephalitis with raised intracranial pressure. Despite numerous case reports of success with potential new treatments, none has been proven safe and/or effective by controlled trials. Although it is tempting to focus on new treatments, the early recognition of severe meningococcal disease by parents, primary care physicians and junior hospital doctors is equally, if not more, important as a potential means of decreasing mortality.

Meningitis without a petechial rash in children in the Hib vaccine era.

AIMS: (1) To determine the causes of meningitis in children immunized with Hib vaccine, presenting without a non-blanching rash; (2) to review the use of dexamethasone in this group. METHOD: Retrospective review of all children with more then 10 white cells/mm(3) in their cerebrospinal fluid (CSF), admitted between January 1998 and August 2002. Children were excluded if they had a non-blanching rash on admission or if their discharge diagnosis was not meningitis. Local guidelines recommended dexamethasone to be given before antibiotics for children with meningitis and no rash. RESULTS: One hundred and eight children were identified. Causes of proven meningitis were: viral 41 (enterovirus 40), bacterial 22. CSF culture or PCR was the only diagnostic test in 31 children. Dexamethasone was given to 16 children. Length of admission was shorter in children with viral compared with bacterial meningitis (4 vs 8 days; P < 0.0001). SUMMARY: Viral meningitis is the commonest cause of meningitis without rash. Enteroviral PCR was the most useful test and needs to be widely available. Confirmation of enteroviral meningitis allowed early discharge. Few children were given dexamethasone, but only 5/108 may have benefited. CONCLUSIONS: The most common cause of meningitis without a rash in British children is enterovirus. The use of dexamethasone in children with meningitis without a rash should be reconsidered or, at least, individualised.

Clinical studies : an overview.

Disease caused by Neisseria meningitidis is a worldwide problem (1). Epi- demics of meningococcal disease regularly occur in the "meningitis belt" of sub-Saharan Africa and in Asia (2-5) and high or increasing levels of endemic meningococcal disease have been reported recently in the UK (6), New Zealand (7), Cuba (8), Brazil (9), Norway (10), and the Pacific Northwest of the United States (11). Meningococcal disease predominantly affects children and has a high mortality, which has remained unchanged for 30 years, despite advances in antibiotics and intensive care (12). Efforts have therefore been made to understand the pathophysiology of the disease and use this knowledge to improve treatment and develop novel therapies.

A survey of tuberculosis services in the UK.

AIM: To determine the provision of services for children with tuberculosis (TB) living in the UK. METHOD: A postal questionnaire was sent to the most appropriate paediatrician and adult physician in every acute hospital trust in the UK. Information was sought on inpatient and outpatient services for children with TB and for children in contact with TB. RESULTS: Responses were received from 323 individuals in 199 of the 205 trusts approached. The median number of children with TB seen per year at each trust was 1.5 (range 0-30). Inpatients were nearly all admitted to paediatric wards (197 (99%) trusts). In 141 trusts (71%) they were looked after solely by paediatricians or jointly by paediatricians and physicians (47 trusts, 24%). 132 (66%) trusts stated there was a named consultant for children with TB. Negative pressure isolation rooms were reported to be available for children in 42 trusts (21%). As outpatients, children with TB were seen in paediatric clinics in 163 (82%) trusts. Only 10 (5%) trusts had designated family TB clinics. Children in contact with TB were managed by paediatricians in 81 (38%) trusts, by physicians in 67 (34%) trusts and jointly in 51 (26%) trusts. 161 (81%) trusts had access to a TB nurse and directly observed therapy (DOTS) was available in 116 (58%) trusts. CONCLUSIONS: Many paediatricians see few children with TB, but most children with TB are looked after by general paediatricians alone. The survey supports national recommendations to develop family clinics and clinical service networks for children with TB, which may improve the care of these children.

Glycopeptide insensitive Staphylococcus aureus subdural empyema treated with linezolid and rifampicin.

A 4-year-old boy had surgical debulking of a cerebral astrocytoma followed by chemotherapy. He developed a subdural empyema with a teicoplanin and methicillin resistant Staphylococcus aureus. He was successfully treated with surgical drainage and 6 weeks of antibiotic therapy which included linezolid, rifampicin and metronidazole. Linezolid may be successful in treating other CNS infections caused by antibiotic resistant gram-positive organisms.

Prospective study of community needlestick injuries.

Fifty three children were referred following community needlestick injuries, August 1995 to September 2003. Twenty five attended for serology six months later. None were positive for HIV, or hepatitis B or C. Routine follow up after community needlestick injury is unnecessary. HIV post-exposure prophylaxis should only be considered in high risk children.