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1.  Contemporary Rates of Severe Hypoglycaemia in Youth with Type 1 Diabetes: Variability by Insulin Regimen 
To determine incidence rates of severe hypoglycaemia and compare incidence rates by insulin regimen in a diverse sample of youth with type 1 diabetes from two sites.
In this observational study, 255 youth (51% female) aged 9–15 years receiving varied insulin regimens provided data prospectively for a median of 1.2 years. Reported episodes of severe hypoglycaemia, defined as episodes requiring help from another person for oral treatment or episodes resulting in seizure/coma, and current insulin regimens were collected systematically. Incidence rates were calculated and compared according to insulin regimen in bivariate and multivariate analyses.
At first encounter, participants had a median age of 12.2 years (range 9.0–15.0), median diabetes duration of 4.4 years (range 1.0–13.0) and mean A1C of 67±12 mmol/mol (8.3±1.1%). The incidence rate was 37.6/100-patient-years for all severe hypoglycaemia and 9.6/100-patient-years for seizure/coma. The incidence rate for severe hypoglycaemia was 31.8/100-patient-years on continuous subcutaneous insulin infusion (CSII), 34.4/100-patient-years on basal-bolus injections (B-B) and 46.1/100-patient-years on NPH (NPH vs. CSII: p=.04). The incidence rate for seizure/coma was 4.5/100-patient-years on CSII, 11.1/100-patient-years on B-B, and 14.4/100-patient-years on NPH (NPH vs. CSII: p=.004). In the multivariate analysis, the rate of seizure/coma was significantly higher for those on NPH vs. CSII (rate ratio 2.9, p=.03).
Rates of severe hypoglycaemia in youth with type 1 diabetes remain high. CSII was associated with lower rates of all severe hypoglycaemia and seizure/coma in comparison to NPH.
PMCID: PMC3597100  PMID: 22417321
Hypoglycaemia; type 1 diabetes; paediatrics; insulin therapy
2.  Comparison of longitudinal point-of-care and high-performance liquid chromatography HbA1c measurements in a multi-centre trial 
Point-of-care HbA1c is routine in clinical practice. Comparison of point-of-care HbA1c against laboratory measurements across sites and over time is warranted.
One hundred and twenty-one young persons with Type 1 diabetes from four centres provided 450 paired samples collected over 10 months for point-of-care HbA1c and central laboratory-based high-performance liquid chromatography (HPLC) HbA1c determinations. Change in HbA1c over time was assessed by difference from initial to final HbA1c and by growth modelling with annualized slope calculation. Change in HbA1c was categorized as improved (decrease of ≥ 0.5% or negative slope), no change (± 0.4% of initial HbA1c or slope = 0) or worsened (increase of ≥ 0.5% or positive slope).
The 450 paired samples (median of four pairs/patient) were highly correlated (r = 0.97, P < 0.0001), as were time-specific and site-specific pairs (r = 0.94 to 0.98, P < 0.0001). Initial-to-final point-of-care HbA1c and HPLC HbA1c changes were 0.3 ± 1.1% (range −2.7 to 4.1) and 0.4 ± 1.2% (–3.9 to 4.5), respectively, with 21% of patients (n = 26) discordant for change categories. ΔHbA1c by point-of-care HbA1c vs. HPLC HbA1c differed across the HbA1c range and by ≥ 0.5% absolute difference in ΔHbA1c in 14 (54%) of the 26 patients discordant for HbA1c change categories. Mean annual HbA1c slope was 0.4 ± 1.5% (−5.4 to 4.8) for point-of-care HbA1c and 0.4 ± 1.6% (−6.9 to 5.2) for HPLC HbA1c, with 18% (n = 22 pairs) discordant for change categories.
Assessment of absolute HbA1c change may not be different for point-of-care HbA1c compared with HPLC HbA1c; however, misclassification of patients by discrete cut-off values may occur with point-of-care HbA1c compared with HPLC HbA1c determinations.
PMCID: PMC3220776  PMID: 21824185
children; HbA1c; point-of-care; Type 1 diabetes
3.  Re-examining a measure of diabetes-related burden in parents of young people with Type 1 diabetes: the Problem Areas in Diabetes Survey – Parent Revised version (PAID-PR) 
In a pediatric patients, the burden of diabetes lies within the family. In the current era of intensive insulin therapy, perceived parental burden may affect the family’s efforts at effective diabetes management. The aims of this study were to re-examine and revise a measure of perceived parental burden associated with caring for a child with diabetes in the current era.
A geographically diverse population of young people (N = 376) with Type 1 diabetes and their parents included participants in the Juvenile Diabetes Research Foundation continuous glucose monitoring study and patients from the Joslin Diabetes Center. Participants provided data on demographics, diabetes management, diabetes-specific family conflict, and quality of life at baseline and after 6 months of follow-up.
Young people were 12.9 ± 2.7 years old with diabetes duration of 6.3 ± 3.5 years. Mean HbA1C was 8.0 ± 1.2%(64 mmol/mol), 58% received insulin pump therapy, and young people monitored blood glucose 5.2 ± 2.3 times/day. Factor analysis yielded two factors, ‘Immediate Burden’ and ’Theoretical Burden’. The Problem Areas in Diabetes Survey – Parent Revised version (PAID-PR) demonstrated excellent internal consistency (Cronbach’s α = 0.87; factor 1 α = 0.78; factor 2 α = 0.83). Greater parental burden was associated with more frequent blood glucose monitoring, higher HbA1C levels, greater diabetes-specific family conflict, and lower quality of life. Test-retest analysis was acceptable (r = 0.62).
The PAID-PR demonstrated excellent internal consistency, good test-retest reliability, and associations with diabetes-specific family conflict and quality of life. This brief measure may have both clinical and research utility in the management of young people with Type 1 diabetes.
PMCID: PMC3510480  PMID: 21883443
adolescence; Type 1 diabetes
4.  Validation of an abbreviated adherence measure for young people with Type 1 diabetes 
Diabetic Medicine  2011;28(9):1113-1117.
Adherence to diabetes-related tasks is an important construct. The Diabetes Self-Management Profile is a validated, semi-structured interview assessing adherence in paediatric patients with Type 1 diabetes. We created and validated a brief questionnaire version of the Diabetes Self-Management Profile called the Diabetes Self-Management Questionnaire.
Young people with Type 1 diabetes, ages 9–15 years (n = 338) and their parents provided data from chart review, interview and questionnaires.
Diabetes Self-Management Questionnaire scores correlated significantly with Diabetes Self-Management Profile scores, HbA1c, blood glucose monitoring frequency and other measures associated with adherence and/or glycaemic control (P ≤ 0.01 for all). Young people and parent scores were correlated (r = 0.55, P < 0.0001). The Diabetes Self-Management Questionnaire demonstrated modest internal consistency (Cronbach’s α = 0.59), adequate for a brief measure of multidimensional adherence. In addition, factor analysis confirmed one factor.
This brief adherence questionnaire demonstrated construct validity in young people 9–15 years old and their parents and may have utility in clinical and research settings.
PMCID: PMC3300068  PMID: 21843307
adherence; paediatrics; Type 1 diabetes
5.  Dynamics of range margins for metapopulations under climate change 
We link spatially explicit climate change predictions to a dynamic metapopulation model. Predictions of species' responses to climate change, incorporating metapopulation dynamics and elements of dispersal, allow us to explore the range margin dynamics for two lagomorphs of conservation concern. Although the lagomorphs have very different distribution patterns, shifts at the edge of the range were more pronounced than shifts in the overall metapopulation. For Romerolagus diazi (volcano rabbit), the lower elevation range limit shifted upslope by approximately 700 m. This reduced the area occupied by the metapopulation, as the mountain peak currently lacks suitable vegetation. For Lepus timidus (European mountain hare), we modelled the British metapopulation. Increasing the dispersive estimate caused the metapopulation to shift faster on the northern range margin (leading edge). By contrast, it caused the metapopulation to respond to climate change slower, rather than faster, on the southern range margin (trailing edge). The differential responses of the leading and trailing range margins and the relative sensitivity of range limits to climate change compared with that of the metapopulation centroid have important implications for where conservation monitoring should be targeted. Our study demonstrates the importance and possibility of moving from simple bioclimatic envelope models to second-generation models that incorporate both dynamic climate change and metapopulation dynamics.
PMCID: PMC2677226  PMID: 19324811
range limits; global warming; extinction risk; population dynamics; elevation; latitude
6.  Combined acetaminophen and ibuprofen for pain relief after oral surgery in adults: a randomized controlled trial 
Acetaminophen is often used with a non-steriodal anti-inflammatory drug for acute pain. Hitherto, these drugs have had to be given separately, typically at different time intervals. Maxigesic® tablets combine acetaminophen and ibuprofen in clinically appropriate doses to simplify administration and dosage regimen. We compared this combination with each of the constituent drugs for the relief of pain after extraction of third molar teeth.
Adults (more than 16 yr) having one or more wisdom teeth removed under general or local anaesthesia were instructed to take two tablets before operation, then two tablets every 6 h for up to 48 h of: (i) a combination of acetaminophen 500 mg and ibuprofen 150 mg per tablet (Maxigesic®); (ii) acetaminophen 500 mg per tablet alone; or (iii) ibuprofen 150 mg per tablet alone. The primary outcome measure was the area under the curve (AUC) of the 100 mm visual analogue scale pain measurements taken for up to 48 h after surgery, divided by time, at rest and on activity. Pharmacokinetic data were collected in a subset of patients.
The mean (sem) time-corrected AUC on rest and activity, respectively, were: combination group 22.3 (3.2) and 28.4 (3.4); acetaminophen group 33.0 (3.1) and 40.4 (3.3); and ibuprofen group 34.8 (3.2) and 40.2 (3.4); P<0.01 for each of the four comparisons of combination vs constituent drug. There was no pharmacokinetic interaction between acetaminophen and ibuprofen administered together.
Maxigesic® tablets provide superior pain relief after oral surgery to acetaminophen or ibuprofen alone.
PMCID: PMC2791549  PMID: 20007794
anaesthesia, dental; analgesia, postoperative; analgesics non-opioid, acetaminophen; analgesics non-opioid, ibuprofen; non-steroidal anti-inflammatory drugs
7.  Morphine pharmacokinetics and pharmacodynamics in preterm and term neonates: secondary results from the NEOPAIN trial 
BJA: British Journal of Anaesthesia  2008;101(5):680-689.
Relationships between plasma morphine concentrations and neonatal responses to endotracheal tube (ETT) suctioning are unknown in preterm neonates.
Ventilated preterm neonates (n=898) from 16 centres were randomly assigned to placebo (n=449) or morphine (n=449). After an i.v. loading dose (100 µg kg−1), morphine infusions [23–26 weeks postmenstrual age (PMA) 10 µg kg−1 h−1; 27–29 weeks 20 µg kg−1 h−1; and 30–32 weeks 30 µg kg−1 h−1] were established for a maximum of 14 days. Open-label morphine (20–100 µg kg−1) was given for pain or agitation. Morphine assay and neonatal response to ETT suctioning was measured at 20–28 and 70–76 h after starting the drug infusion and at 10–14 h after discontinuation of the study drug. The concentration–effect response was investigated using non-linear mixed effects models.
A total of 5119 data points (1598 measured morphine concentrations and 3521 effect measures) were available from 875 neonates for analysis. Clearance was 50% that of the mature value at 54.2 weeks PMA (CLmat50) and increased from 2.05 litre h−1 70 kg−1 at 24 weeks PMA to 6.04 litre h−1 70 kg−1 at 32 weeks PMA. The volume of distribution in preterm neonates was 190 litre 70 kg−1 (CV 51%) and did not change with age. There was no relationship between morphine concentrations (range 0–440 µg litre−1) and heart rate changes associated with ETT suctioning or with the Premature Infant Pain Profile.
A sigmoid curve describing maturation of morphine clearance is moved to the right in preterm neonates and volume of distribution is increased compared with term neonates. Morphine does not alter the neonatal response to ETT suctioning.
PMCID: PMC2733178  PMID: 18723857
anaesthesia, paediatric; anaesthetic–analgesic regimens; analgesics opioid, morphine; model, pharmacodynamic; model, pharmacokinetic
8.  Cerebrospinal Fluid Compartmental Pharmacokinetics of Amikacin in Neonates▿  
To describe and investigate the covariate effects of cerebrospinal fluid (CSF) amikacin pharmacokinetics in neonates, CSF samples were prospectively collected from neonates in whom amikacin had been initiated before a diagnostic lumbar puncture was performed. CSF analysis (amikacin concentration, white blood count [WBC], glucose content, and protein concentration) and amikacin therapeutic drug monitoring results (peak and trough concentrations) in serum were recorded. Correlations (Spearman rank) between the CSF amikacin concentration and the CSF WBC and glucose and protein concentration were investigated. There were 44 CSF amikacin concentrations and 83 serum samples available from 43 neonates (mean postmenstrual age, 36 weeks [range, 26 to 41 weeks]; mean weight, 2.43 kg [range, 0.87 to 3.86 kg]). The median time interval between initiation of amikacin administration and CSF sampling was 25 h (range, 2.5 to 93.7 h). The median amikacin concentration in the CSF was 1.08 mg/liter (range, 0.34 to 2.65 mg/liter), and the mean trough and peak amikacin concentrations in serum were 3.8 ± 2.5 mg/liter and 35.7 ± 5.9 mg/liter, respectively. A correlation between CSF amikacin and CSF protein contents (P < 0.01, r = 0.41, 95% confidence interval = 0.13 to 0.63) but not between CSF WBC and CSF glucose was documented. A two-compartment (central and CSF) linear disposition model was used to estimate population pharmacokinetics. The half time for equilibration (Teq) between serum and CSF compartments was used as a measure of blood-brain barrier permeability. The Teq was 7.58 h (coefficient of variation [CV] = 49.1%) with a partition coefficient of 0.103 (CV = 26.4%). There was no relationship between the Teq and CSF WBC, CSF glucose content, or CSF protein content.
PMCID: PMC2415815  PMID: 18378715
9.  Morphogenetic expression of Bacteroides nodosus fimbriae in Pseudomonas aeruginosa. 
Journal of Bacteriology  1987;169(1):33-41.
Type 4 fimbriae are found in a range of pathogenic bacteria, including Bacteroides nodosus, Moraxella bovis, Neisseria gonorrhoeae, and Pseudomonas aeruginosa. The structural subunits of these fimbriae all contain a highly conserved hydrophobic amino-terminal sequence preceding a variable hydrophilic carboxy-terminal region. We show here that recombinant P. aeruginosa cells containing the B. nodosus fimbrial subunit gene under the control of a strong promoter (pL, from bacteriophage lambda) produced large amounts of fimbriae that were structurally and antigenically indistinguishable from those produced by B. nodosus. This was demonstrated by fimbrial isolation and purification, electrophoretic and Western transfer analyses, and immunogold labeling and electron microscopy. These results suggest that type 4 fimbriated bacteria use a common mechanism for fimbrial assembly and that the structural subunits are interchangeable, thereby providing a basis for the development of multivalent vaccines.
PMCID: PMC211730  PMID: 2878919
10.  Massive hemoptysis. 
Hemoptysis is usually a symptom of cardiopulmonary disease and is generally not in itself associated with death. A blood loss into the tracheobronchial tree of 600 ml in 24 hours or at a rate that poses a threat to life is referred to as massive hemoptysis. Hypervascularity within the bronchial circulation, usually associated with diffuse inflammatory disease of the lung, is common in patients with massive hemoptysis. Management should be directed at maintenance of oxygenation and localization of the source of bleeding. Temporizing maneuvers such as iced saline lavage, intravenous administration of vasopressin, endobronchial tamponade and bronchial artery embolization will often stabilize the patient in preparation for definitive surgery. Such a sequential plan of management may result in a 50% reduction in the rate of death from massive hemoptysis, which is otherwise 50% to 100%.
PMCID: PMC1491768  PMID: 3533242
11.  Western blot (immunoblot) analysis of the fimbrial antigens of Bacteroides nodosus. 
Journal of Bacteriology  1987;169(9):4018-4023.
The roles of the fimbrial subunit and the putative basal protein antigens in the serological classification of Bacteroides nodosus have been examined by Western blot (immunoblot)-antibody binding studies of fimbriae isolated from a wide range of strains representative of different serogroups and serotypes. Fimbrial subunits were recognized by antiserum against the homologous serogroup but not generally by heterologous antisera, whereas recognition of the basal antigen was independent of serological classification. Secondary cross-reaction patterns among fimbrial subunits indicated that some serogroups may be more closely related than others. Examples include serogroups C and G and serogroups D and H. Similar analyses of isolates classified within serotypes A1 and A2, with serotype-specific antisera, showed that this subdivision is also determined by the fimbrial subunit and that significant variation does occur even at this level. These studies suggest that the various serogroups and serotypes of B. nodosus comprise a series of overlapping sets of antigenically related strains.
PMCID: PMC213702  PMID: 2887544
12.  Variation in the structural subunit and basal protein antigens of Bacteroides nodosus fimbriae. 
Journal of Bacteriology  1986;166(2):453-460.
The fimbriae of Bacteroides nodosus play a major role in protective immunity against ovine footrot and are an important determinant in the serological classification system that divides field isolates into at least eight serogroups and 16 serotypes. Purified fimbriae contain two polypeptide antigens, the structural subunit of the fimbrial strand (molecular weight about 17,000) and a basal protein (molecular weight about 80,000), both of which exhibit structural variation. Fimbriae were prepared from all prototype strains, as well as from a number of other isolates representative of each of the B. nodosus serotypes, and analyzed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Substantial variation was observed in the electrophoretic mobility of the fimbrial subunits from the prototypes of each of the eight serogroups. With the exception of serogroup H, which is an unusual case, the apparent molecular weights of the fimbrial subunits ranged from about 16,500 in serogroup D to 19,000 in serogroup F (serotype 1); in serogroup A, B, C and E, the apparent molecular weights were clustered in the range of 17,000 to 17,500, whereas serogroup G was about 18,500. Serogroup H fimbriae appeared to consist of two smaller polypeptides, which in the prototype (H1) had apparent molecular weights of about 6,000 and 10,000 and which seem to have arisen as a consequence of an internal proteolytic nick in the original subunit. Electrophoretic variation in the fimbrial subunit was also observed between different serotypes, although with the exceptions of serogroups F and H, this was not as pronounced as between the serogroups. Examination of a number of isolates classified within the same serotypes showed that some variation, although minor, also occurred at this level. The basal antigen exhibited significant variation at all levels of the serotypic hierarchy in a manner apparently unrelated to the classification system. Among the range of isolates examined, the apparent molecular weight of this antigen varied from about 77,000 to 88,000.
PMCID: PMC214626  PMID: 2422154
13.  Cloning and expression in Escherichia coli of the gene encoding the structural subunit of Bacteroides nodosus fimbriae. 
Journal of Bacteriology  1984;160(2):748-754.
Bacteroides nodosus is the primary causative agent of ovine foot rot. Virulent isolates of this bacterium contain fimbriae which appear to play a major role in both infectivity and protective immunity. This paper presents the cloning and expression in Escherichia coli of the gene encoding the structural subunit of the fimbriae of B. nodosus. Total DNA was isolated from B. nodosus VCS 1001 (serogroup A), digested with HindIII, and inserted into the positive-selection vector pTR262. Recombinant E. coli clones were screened directly with anti-fimbrial antiserum by using a colony immunoassay. Several positive colonies were identified, each of which contained the same 5.5-kilobase HindIII insert. The prototype has been designated pBA101. Some clones also contained additional flanking sequences from the B. nodosus genome. Western transfer analyses verified that the positive clones were producing the B. nodosus fimbrial structural subunit, molecular weight ca. 17,500. The level of expression of the antigen in E. coli was comparable to that in B. nodosus itself and was unaffected by the insertion site or orientation of the cloned fragment, indicating that synthesis was being directed from an internal promoter. Restriction mapping and deletion analyses localized the fimbrial subunit gene to the vicinity of a PvuII site near the central region of the original HindIII insert. The expressed antigen was located in the membrane-cell wall fraction and may be exposed on the surface of the recombinant E. coli cells.
PMCID: PMC214800  PMID: 6150025
14.  Isolation and characterization of Bacteroides nodosus fimbriae: structural subunit and basal protein antigens. 
Journal of Bacteriology  1984;160(2):740-747.
We examined the isolation of fimbriae from Bacteroides nodosus. It was found that the best preparations were obtained from the supernatant of washed cells cultured on solid medium, from which fimbriae could be recovered in high yield and purity by a simple one-step procedure. Analysis of such preparations by sodium dodecyl sulfate gel electrophoresis showed that greater than 98% of the protein consisted of fimbrial structural subunits whose molecular weight was ca. 17,000. These preparations also usually exhibited minor contamination with a polypeptide of ca. 80,000 molecular weight, as well as trace amounts of lipopolysaccharide. Attempts to release additional fimbriae by the traditional means of subjecting the bacterial cells to physical stress, such as shearing or heating, resulted primarily in an increase in the level of contamination, without significant gain in the yield of fimbriae. Removal of the 80,000-dalton component could not be achieved by any of a variety of techniques normally used in fimbriae purification, including isoelectric precipitation, MgCl2 precipitation, and CsCl gradient ultracentrifugation, implying a direct physical association with the fimbrial strand. Electron micrographs of fractions containing this protein show cap-shaped structures attached to the ends of what appeared to be fimbrial stubs. These observations suggest that the 80,000-dalton polypeptide may actually constitute the basal attachment site which anchors the fimbria to the outer membrane, analogous to a similar protein recently described in enterotoxigenic strains of Escherichia coli. In B. nodosus, this 80,000-dalton protein is a major surface antigen, and like the fimbrial subunit, exhibited variation in electrophoretic mobility between serotypically different isolates.
PMCID: PMC214799  PMID: 6150024

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