Identification of vaccine candidates against serogroup B meningococcus by whole-genome sequencing

Neisseria meningitidis is a major cause of bacterial septicemia and meningitis. Sequence variation of surface-exposed proteins and cross-reactivity of the serogroup B capsular polysaccharide with human tissues have hampered efforts to develop a successful vaccine. To overcome these obstacles, the entire genome sequence of a virulent serogroup B strain (MC58) was used to identify vaccine candidates. A total of 350 candidate antigens were expressed in Escherichia coli, purified, and used to immunize mice. The sera allowed the identification of proteins that are surface exposed, that are conserved in sequence across a range of strains, and that induce a bactericidal antibody response, a property known to correlate with vaccine efficacy in humans.

Large-scale discovery of novel genetic causes of developmental disorders

Despite three decades of successful, predominantly phenotype-driven discovery of the genetic causes of monogenic disorders, up to half of children with severe developmental disorders of probable genetic origin remain without a genetic diagnosis. Particularly challenging are those disorders rare enough to have eluded recognition as a discrete clinical entity, those with highly variable clinical manifestations, and those that are difficult to distinguish from other, very similar, disorders. Here we demonstrate the power of using an unbiased genotype-driven approach to identify subsets of patients with similar disorders. By studying 1,133 children with severe, undiagnosed developmental disorders, and their parents, using a combination of exome sequencing and array-based detection of chromosomal rearrangements, we discovered 12 novel genes associated with developmental disorders. These newly implicated genes increase by 10% (from 28% to 31%) the proportion of children that could be diagnosed. Clustering of missense mutations in six of these newly implicated genes suggests that normal development is being perturbed by an activating or dominant-negative mechanism. Our findings demonstrate the value of adopting a comprehensive strategy, both genome-wide and nationwide, to elucidate the underlying causes of rare genetic disorders.

Complete genome sequence of Neisseria meningitidis serogroup B strain MC58

The 2,272,351-base pair genome of Neisseria meningitidis strain MC58 (serogroup B), a causative agent of meningitis and septicemia, contains 2158 predicted coding regions, 1158 (53.7%) of which were assigned a biological role. Three major islands of horizontal DNA transfer were identified; two of these contain genes encoding proteins involved in pathogenicity, and the third island contains coding sequences only for hypothetical proteins. Insights into the commensal and virulence behavior of N. meningitidis can be gleaned from the genome, in which sequences for structural proteins of the pilus are clustered and several coding regions unique to serogroup B capsular polysaccharide synthesis can be identified. Finally, N. meningitidis contains more genes that undergo phase variation than any pathogen studied to date, a mechanism that controls their expression and contributes to the evasion of the host immune system.

Autoxidation of polyunsaturated fatty acids: II. A suggested mechanism for the formation of TBA-reactive materials from prostaglandin-like endoperoxides

The nature and mechanism of formation of the thiobarbituric acid (TBA)-reaction material produced in the autoxidation of polyunsaturated fatty acids (PUFA) or their esters has been studied. On the basis of chemical studies and spectroscopic evidence, it is concluded that the TBA test detects malonaldehyde which arises at least in part from the acid-catalyzed or thermal decomposition or endoperoxides (2,3-dioxanorbornane compounds). These endoperosides have structures related to those of the endoperoxides produced in the biosynthetic sequence leading to prostaglandins. A mechanism is proposed in which these endoperoxides are formed in a free radical cyclization process operating in competition with hydroperoxide formation during the autoxidation of PUFA or their esters containing three or more double bonds. When 20:3 or 20:4 PUFA undergo autoxidation, some of the natural, physiologically active prostaglandins would be produced, although in very low yield, along with many other stereo- and positional isomers. Thus, it is possible that some of the complex symptoms of lipid peroxidation in vivo could be due to nonenzymatically produced prostaglandins or their steroisomers.

Identification of the familial cylindromatosis tumour-suppressor gene

Familial cylindromatosis is an autosomal dominant genetic predisposition to multiple tumours of the skin appendages. The susceptibility gene (CYLD) has previously been localized to chromosome 16q and has the genetic attributes of a tumour-suppressor gene (recessive oncogene). Here we have identified CYLD by detecting germline mutations in 21 cylindromatosis families and somatic mutations in 1 sporadic and 5 familial cylindromas. All mutations predict truncation or absence of the encoded protein. CYLD encodes three cytoskeletal-associated-protein-glycine-conserved (CAP-GLY) domains, which are found in proteins that coordinate the attachment of organelles to microtubules. CYLD also has sequence homology to the catalytic domain of ubiquitin carboxy-terminal hydrolases (UCH).

Mutations in the gamma(2) subunit of AMP-activated protein kinase cause familial hypertrophic cardiomyopathy: evidence for the central role of energy compromise in disease pathogenesis

Familial hypertrophic cardiomyopathy (HCM) has been widely studied as a genetic model of cardiac hypertrophy and sudden cardiac death. HCM has been defined as a disease of the cardiac sarcomere, but mutations in the known contractile protein disease genes are not found in up to one-third of cases. Further, no consistent changes in contractile properties are shared by these mutant proteins, implying that an abnormality of force generation may not be the underlying mechanism of disease. Instead, all of the sarcomeric mutations appear to result in inefficient use of ATP, suggesting that an inability to maintain normal ATP levels may be the central abnormality. To test this hypothesis we have examined candidate genes involved in energy homeostasis in the heart. We now describe mutations in PRKAG2, encoding the gamma(2) subunit of AMP-activated protein kinase (AMPK), in two families with severe HCM and aberrant conduction from atria to ventricles in some affected individuals (pre-excitation or Wolff-Parkinson-White syndrome). The mutations, one missense and one in-frame single codon insertion, occur in highly conserved regions. Because AMPK provides a central sensing mechanism that protects cells from exhaustion of ATP supplies, we propose that these data substantiate energy compromise as a unifying pathogenic mechanism in all forms of HCM. This conclusion should radically redirect thinking about this disorder and also, by establishing energy depletion as a cause of myocardial dysfunction, should be relevant to the acquired forms of heart muscle disease that HCM models.

Intrapartum asphyxia: a rare cause of cerebral palsy

Data on all children with spastic cerebral palsy (N = 183) and on a matched group of control children (N = 549) born in Western Australia between 1975 and 1980 were compared to investigate the relationship between birth asphyxia and spastic cerebral palsy. Information on perinatal events for both the children with cerebral palsy and the control subjects was collected by means of epidemiologic methods to reduce bias. An association between clinically observed perinatal signs of birth asphyxia and spastic cerebral palsy was found (relative risk 2.84; 95% confidence interval 1.85 to 4.37). The population-attributable risk proportion was 14.1%. The likelihood of birth asphyxia's causing perinatal brain damage was assessed by two independent observers using defined criteria. It was estimated that in only about 8% (15/183) of all the children with spastic cerebral palsy was intrapartum asphyxia the possible cause of their brain damage. The contribution of intrapartum events and obstetric mismanagement to overall cerebral palsy rates is probably less than was previously thought.

Intrauterine growth and spastic cerebral palsy. I. Association with birth weight for gestational age

Birth weight, gestational age at delivery, and other factors were collected for 171 white children with spastic cerebral palsy. Their birth weights were compared with the birth weight distribution expected for a population of the same race, gestation, sex, maternal height, and parity, born in the same geographic area, and during the same time period. Birth weights of children with spastic cerebral palsy tended to be significantly lower than the median birth weight of their comparison population. Analysis stratified by gestation at delivery suggested that if the reduced birth weight were causally associated with the spastic cerebral palsy, 22% of cases were attributable to being below the 10th percentile of the comparison population birth weight distribution. The risk of spastic cerebral palsy associated with poor intrauterine growth was dependent on gestation at delivery; poorly grown infants delivered between 34 and 37 weeks' gestation were at highest risk. Some probable pathways by which growth retardation could result in brain damage (intrapartum hypoxia, hypoglycemia, and hypothermia) were investigated. Only intrapartum hypoxia may have played a causal role but probably accounted for less than 2% of all cases. These data suggest that spastic cerebral palsy is associated with poor intrauterine growth in infants of more than 33 weeks' gestation, but no important causal mechanism has yet been identified.

Year-long weight loss treatment for obese patients with type II diabetes: does including an intermittent very-low-calorie diet improve outcome?

PURPOSE

To evaluate a year-long behavioral weight control program, used with and without an intermittent very-low-calorie diet (VLCD) in the treatment of type II diabetes mellitus.

PATIENTS AND METHODS

Subjects (n = 93) were randomly assigned to 50-week treatment programs that used either a balanced low-calorie diet (LCD) of 1,000 to 1,000 kilocalories (kcal) per day throughout or included 2 12-week periods of a VLCD of 400 to 500 kcal per day alternating with the balanced LCD. Weight, glycemic control, blood pressure, and lipids were assessed at baseline, at the end of the year-long treatment, and at 2-year follow-up.

RESULTS

Subjects in the VLCD program lost significantly more weight than did LCD subjects at the end of the 50-week program (14.2 kg versus 10.5 kg; P = 0.057) and remained off diabetes medication longer (P < 0.05). These benefits of the VLCD were due primarily to the first 12 weeks of the diet; the second diet maintained, but did not increase, these effects. Subjects in both groups experienced marked improvements in glycemic control and cardiovascular risk factors over the year-long program, but attendance declined in the latter weeks of treatment and weight was regained. There was also marked recidivism in both groups in the year following treatment.

CONCLUSIONS

The intermittent VLCD improved weight loss and glycemic control, but these effects were quite modest and do not appear to justify the clinical use of an intermittent VLCD. Moreover, lengthening treatment to a full year did not prevent relapse. Thus, further research is needed to develop a successful approach to long-term weight control.

What constitutes cerebral palsy?

Cerebral palsy (CP) is a term of convenience applied to a group of motor disorders of central origin defined by clinical description. It is not a diagnosis in that its application infers nothing about pathology, aetiology, or prognosis. It is an umbrella term covering a wide range of cerebral disorders which result in childhood motor impairment. The precise inclusion criteria vary with the objectives for using the term. For meaningful comparison of rates of CP, as performed by and between CP registers, it is important that the rates should be generated using the same criteria. As generally understood there must be motor impairment, and this impairment must stem from a malfunction of the brain (rather than spinal cord or muscles). Furthermore, the brain malfunction must be non-progressive and it must be manifest early in life. For the purposes of comparisons of rates across time even when the condition meets all the above criteria, it must not historically have been excluded from the category of CP. This paper addresses the problem of standardizing the inclusion criteria for selecting people included on CP registers with particular reference to this last criterion.

Young children's use of functional information to categorize artifacts: three factors that matter

Three experiments addressed factors that might influence whether or not young children take into account function, as opposed to overall appearance or shape, when they extend the names of novel artifacts. Experiment 1 showed that 4-year-olds more often extend a name on the basis of a demonstrated function when that function provides a plausible causal account of perceptible object structure. Experiment 2 showed that they more often extend a name by function when they respond slowly, and hence thoughtfully. Experiment 3 demonstrated that they are more likely to take function into account when they extend names than when they judge similarities. Comparisons of lexical and non-lexical conditions in younger children failed to show any differences. Overall, the findings suggest that by 4 years of age, children may learn names as labels for novel artifact kinds rather than perceptual classes, and that the processes by which they categorize may be mindful and reflective, as in adults.

Intensity of vascular endothelial growth factor expression is associated with increased risk of recurrence and decreased disease-free survival in papillary thyroid cancer

BACKGROUND

Vascular endothelial growth factor (VEGF) induces proliferation of endothelial cells, stimulates angiogenesis, and increases vascular permeability. Increased VEGF expression has been associated with poor clinical outcomes in many malignancies. Several recent reports have documented over expression of VEGF in papillary thyroid cancer. We hypothesized that increased expression of VEGF would be associated with either an increased risk of recurrence or a decreased recurrence-free survival in papillary thyroid cancer.

METHODS

Immunohistochemistry was used to detect VEGF expression in archival paraffin-embedded surgical thyroid specimens from 96 subjects with papillary thyroid cancer.

RESULTS

VEGF expression was detected in 98% (94/96) of the samples, predominantly of slight-to-moderate intensity in the majority of malignant cells. However, the specific finding of a diffuse pattern of intense immunostaining for VEGF was detected significantly more often than less intense, patchy immunostaining patterns in subjects with distant metastasis at diagnosis (63% versus 15%, P =.005), local recurrence (58% versus 13%, P =.001), and distant recurrence (83% versus 14%, P =.001). Furthermore, this specific pattern of diffuse, intense VEGF expression was associated with a significantly shorter recurrence-free survival than other staining patterns (P =.007).

CONCLUSIONS

These data demonstrate that the immunohistochemical pattern of VEGF staining in the initial surgical specimen is strongly associated with the incidence of local and distant metastasis in papillary thyroid cancer.

Life expectancy among people with cerebral palsy in Western Australia

This report describes trends, predictors, and causes of mortality in persons with cerebral palsy (CP) using individuals identified by the Western Australian Cerebral Palsy Register and born between 1958 and 1994. Two thousand and fourteen people were identified (1154 males, 860 females), of whom 225 had died by 1 June 1997. Using date-of-death data, crude and standardized mortality rates were estimated and predictors of mortality sought using survival analysis stratified by decade of birth, description of impairments, and demographic and perinatal variables. For those born after 1967, the cause of death profile was examined over time. Mortality exceeded 1% per annum in the first 5 years and declined to age 15 years after which it remained steady at about 0.35% for the next 20 years. The strongest single predictor was intellectual disability, but all forms of disability contributed to decreased life expectancy. Half of those with IQ/DQ score <20 survived to adulthood, increasing to 76% with IQ/DQ score 20-34, and exceeding 92% for higher scores. Severe motor impairment primarily increased the risk of early mortality. Despite there being 72 persons aged from 25 to 41 years with severe motor impairment in our data set, none had died after the age of 25 years. Infants born after more than 32 weeks' gestation were at significantly higher risk of mortality than very preterm infants, accounted for by their higher rates of intellectual disability. No improvements in survival of persons with CP were seen over the study period despite advances in medical care, improved community awareness, and the increasing proportion of very preterm births among people with CP. This may be the result of improved neonatal care enabling the survival of infants with increasingly severe disabilities.

When can cerebral palsy be prevented? The generation of causal hypotheses by multivariate analysis of a case-control study

Causal hypotheses for spastic cerebral palsy were sought by comparing a population based sample of 183 cases with 549 matched controls. A time-ordered multivariate analysis was used to distinguish confounders and consequences of disease from possible causes, which could be single factors or sequences of factors. Eighteen factors were identified as having an association with spasticity that did not arise by confounding with other identified factors nor as a consequence of the disease. Nearly half the cases (48.6%) but only 14.4% of controls experienced one or more of these factors, but no one factor was experienced by > 11%, and most by < 5%, of cases. Those factors identified as occurring before labour commenced affected 35% of all cases. The proportion of cases experiencing identified factors and the distribution of those factors between epochs varied with gestation of delivery and with description and severity of impairment. The possible timing of causes in cases without identified factors and the role of preterm birth and poor intrauterine growth are discussed. We conclude that there were many pathways to spastic cerebral palsy many of which could not be identified. Each contributed only a small proportion and many may have been multifactorial. Intrapartum initiation of the aetiological pathway was relatively unimportant, being likely in about 9% of cases, but the majority of pathways commenced predelivery.

Randomised controlled trial of oxytocin alone versus oxytocin and ergometrine in active management of third stage of labour

OBJECTIVE

To compare intramuscular oxytocin alone and intramuscular oxytocin with ergometrine (Syntometrine) for their effect in reducing the risk of postpartum haemorrhage when both are used as part of the active management of the third stage of labour.

DESIGN

Double blind, randomised controlled trial.

SETTING

Two metropolitan teaching hospitals in Perth, Western Australia.

SUBJECTS

All women who expected a vaginal birth during the period of the trial. Informed consent was obtained.

MAIN OUTCOME MEASURES

Postpartum haemorrhage, nausea, vomiting, and increased blood pressure.

RESULTS

3497 women were randomly allocated to receive oxytocin-ergometrine (n = 1730) or oxytocin (n = 1753). Rates of postpartum haemorrhage (> or = 500 ml or > or = 1000 ml) were similar in both arms (odds ratio 0.90 (0.82); 95% confidence interval 0.75 to 1.07 (0.59 to 1.14) at 500 ml (1000 ml) threshold). The use of oxytocin-ergometrine was associated with nausea, vomiting, and increased blood pressure.

CONCLUSIONS

There are few advantages but several disadvantages for the routine use of oxytoxinergometrine when prophylactic active management of the third stage of labour is practised. Further investigation of dose-response for oxytocin may be warranted.

Autoxidation of polyunsaturated fatty acids. Part I. Effect of ozone on the autoxidation of neat methyl linoleate and methyl linolenate

Neat samples of polyunsaturated fatty acids were exposed to ozone in air in a flow system, and the formation of peroxides, conjugated dienes and thiobarbituric acid (TBA)-reactive material was followed as a function of time. The effect of ozone is to shorten the induction period normally observed in autoxidation studies, but the ozone, at the concentrations used here (0-1.5 ppm), appears to have no effect on the rates of product formation after the induction period. During the induction period, increasing ozone concentrations give rise to substantially increased rates of peroxide (or materials which titrate like peroxide) formation, a slightly increased rate of conjugated diene formation, and no significant increase in the rate of production of TBA-reactive material. Vitamin E lengthens the induction period but appears to have no other effect. Some of these data are in conflict with earlier reports of Menzel et al.

Interobserver agreement in the classification of cerebral palsy

Interobserver variation in diagnosis is thought to be an important source of bias in studies of cerebral palsy. Kappa (kappa) statistics were used as a measure of interobserver diagnostic agreement for two case series of 20 children attending an institution for the motor handicapped. kappa increased threefold after standardisation of diagnostic terms. Sources of diagnostic variation are discussed and possibilities and benefits of its further reduction explored.

Why have we failed to reduce the frequency of cerebral palsy?

OBJECTIVE

To review the data on children with cerebral palsy in relation to quality of obstetric care.

DATA SOURCES AND STUDY SELECTION

In our Institute, a regular Medline print-out, certain key journals and Current Contents are perused to create an updated computerised file of publications on the epidemiological, aetiological and other aspects of cerebral palsy. For this study we reviewed data from the Western Australian Cerebral Palsy Register, more than 150 publications from which studies were chosen for sound methodology in countries with modern obstetric practices, and recent population data on cerebral palsy.

DATA EXTRACTION AND SYNTHESIS

Three major areas were studied to see: (i) if the prevalence of cerebral palsy has fallen with increasing use of obstetric and neonatal interventions aimed at reducing birth asphyxia; (ii) if there is any evidence that cerebral palsy is caused by birth asphyxia; and (iii) if there is any evidence that intrapartum fetal monitoring or caesarean section reduces the prevalence of cerebral palsy.

CONCLUSIONS

We concluded that: cerebral palsy proportions are not falling in spite of significant increases in obstetric and neonatal interventions aimed at reducing asphyxia; cerebral palsy proportions in low birthweight infants are rising in most developed countries, coincident with increases in the neonatal survival of low birthweight babies; few cases of cerebral palsy seem to be caused by birth asphyxia and those that are may not have been preventable by obstetric care; and parents will continue to sue if obstetricians keep promising perfection from obstetric care in the face of 2.0-2.5 cases of cerebral palsy per 1000 children born.

Antenatal antecedents of moderate and severe cerebral palsy

Aetiological relationships between cerebral palsy, preterm birth, small-for-gestational-age (SGA) birth and selected feto-maternal factors were investigated in a case-control study of all moderate and severe cerebral palsy cases born in Western Australia between 1980 and 1986 (n = 215). Cases were individually matched to three controls of the same gender and plurality born in the same year. Two of the controls were matched to the index cases for gestational age, one of which was also matched for birthweight. Pre-eclampsia and urinary tract infections were not significantly associated with cerebral palsy. The significant association of antepartum haemorrhage with cerebral palsy was accounted for by its associations with preterm birth. Congenital malformations and non-cerebral palsy neurological disorder were significantly associated with cerebral palsy; these associations were only partially accounted for by adjusting for preterm birth and small-for-gestational-age birth. This study shows that some of the risk of cerebral palsy associated with the antenatal antecedents of some common feto-maternal factors is mediated through preterm birth, confirming the importance of interrelationships between antenatal antecedents in the aetiology of some cerebral palsy. Perinatal and post-neonatal causes now account for only around 20% of all cerebral palsy. Future reductions in cerebral palsy incidence may therefore depend on acquiring greater knowledge of inter-relationships between antenatal antecedents.

Effectiveness of five days of therapy with cefuroxime axetil suspension for treatment of acute otitis media

BACKGROUND

In recent years there has been considerable interest in reducing the duration of antibiotic treatment regimens in patients with common bacterial infections. We conducted two independent, investigator-blinded, multicenter, randomized clinical trials, one of which included microbiologic evaluation of middle ear fluid obtained by tympanocentesis, comparing the efficacy and safety of 5 or 10 days of treatment with cefuroxime axetil suspension (CAE) with that of 10 days of treatment with amoxicillin/clavulanate suspension (AMX/CL) in children with acute otitis media.

METHODS

A total of 719 pediatric patients from the ages of 3 months to 12 years were enrolled in the 2 studies. Patients received CAE for either 5 or 10 days at 30 mg/kg/day in 2 divided doses (n = 242 and 235, respectively) or AMX/CL for 10 days at 40 mg/kg/day in 3 divided doses (n = 242). Patients in the CAE (5 days) group received placebo on Days 6 through 10. In the study that included tympanocentesis, bacteriologic assessments were based on middle ear fluid cultures obtained pretreatment and, when possible, after treatment in patients with an unsatisfactory clinical outcome.

RESULTS

Organisms were isolated from the pretreatment middle ear fluid specimens of 177 of 244 (73%) patients undergoing tympanocentesis, with the primary pathogens being Streptococcus pneumoniae, Haemophilus influenzae and Moraxella catarrhalis (37, 35 and 12% of isolates, respectively). Pathogens were eradicated or presumed to be eradicated in 92% (24 of 26), 84% (32 of 38) and 95% (36 of 38) of bacteriologically evaluable patients treated with CAE for 5 or 10 days or with AMX/CL, respectively. A satisfactory clinical outcome (cure or improvement) occurred in 69% (101 of 147), 70% (121 of 173) and 74% (131 of 177) of clinically evaluable patients treated with CAE (5 days), CAE (10 days) or AMX/CL, respectively. Treatment with AMX/CL was associated with a significantly higher incidence of drug-related adverse events than was treatment with CAE for either 5 or 10 days (P < 0.001), primarily reflecting a higher incidence of drug-related gastrointestinal adverse events (34% vs. 17 and 12%, respectively; P < 0.001), particularly diarrhea.

CONCLUSIONS

Treatment with CAE given twice daily for 5 days is equivalent to treatment for 10 days either with the same regimen of CAE or with AMX/CL given three times daily in pediatric patients with acute otitis media.