Informing Patient-Centered Care Through Stakeholder Engagement and Highly Stratified Quantitative Benefit-Harm Assessments.

OBJECTIVES: In a previous project aimed at informing patient-centered care for people with multiple chronic conditions, we performed highly stratified quantitative benefit-harm assessments for 2 top priority questions. In this current work, our goal was to describe the process and approaches we developed and to qualitatively glean important elements from it that address patient-centered care. METHODS: We engaged patients, caregivers, clinicians, and guideline developers as stakeholder representatives throughout the process of the quantitative benefit-harm assessment and investigated whether the benefit-harm balance differed based on patient preferences and characteristics (stratification). We refined strategies to select the most applicable, valid, and precise evidence. RESULTS: Two processes were important when assessing the balance of benefits and harms of interventions: (1) engaging stakeholders and (2) stratification by patient preferences and characteristics. Engaging patients and caregivers through focus groups, preference surveys, and as co-investigators provided value in prioritizing research questions, identifying relevant clinical outcomes, and clarifying the relative importance of these outcomes. Our strategies to select evidence for stratified benefit-harm assessments considered consistency across outcomes and subgroups. By quantitatively estimating the range in the benefit-harm balance resulting from true variation in preferences, we clarified whether the benefit-harm balance is preference sensitive. CONCLUSIONS: Our approaches for engaging patients and caregivers at all phases of the stratified quantitative benefit-harm assessments were feasible and revealed how sensitive the benefit-harm balance is to patient characteristics and individual preferences. Accordingly, this sensitivity can suggest to guideline developers when to tailor recommendations for specific patient subgroups or when to explicitly leave decision making to individual patients and their providers.

Outcome preferences of older people with multiple chronic conditions and hypertension: a cross-sectional survey using best-worst scaling.

BACKGROUND: Older people with hypertension and multiple chronic conditions (MCC) receive complex treatments and face challenging trade-offs. Patients' preferences for different health outcomes can impact multiple treatment decisions. Since evidence about outcome preferences is especially scarce among people with MCC our aim was to elicit preferences of people with MCC for outcomes related to hypertension, and to determine how these outcomes should be weighed when benefits and harms are assessed for patient-centered clinical practice guidelines and health economic assessments. METHODS: We sent a best-worst scaling preference survey to a random sample identified from a primary care network of Kaiser Permanente (Colorado, USA). The sample included individuals age 60 or greater with hypertension and at least two other chronic conditions. We assessed average ranking of patient-important outcomes using conditional logit regression (stroke, heart attack, heart failure, dialysis, cognitive impairment, chronic kidney disease, acute kidney injury, fainting, injurious falls, low blood pressure with dizziness, treatment burden) and studied variation across individuals. RESULTS: Of 450 invited participants, 217 (48%) completed the survey, and we excluded 10 respondents who had more than two missing choices, resulting in a final sample of 207 respondents. Participants ranked stroke as the most worrisome outcome and treatment burden as the least worrisome outcome (conditional logit parameters: 3.19 (standard error 0.09) for stroke, 0 for treatment burden). None of the outcomes were always chosen as the most or least worrisome by more than 25% of respondents, indicating that all outcomes were somewhat worrisome to respondents. Predefined subgroup analyses according to age, self-reported life-expectancy, degree of comorbidity, number of medications and antihypertensive treatment did not reveal meaningful differences. CONCLUSIONS: Although some outcomes were more worrisome to patients than others, our results indicate that none of the outcomes should be disregarded for clinical practice guidelines and health economic assessments.

Balance of benefits and harms of different blood pressure targets in people with multiple chronic conditions: a quantitative benefit-harm assessment.

OBJECTIVE: Recent studies suggest that a systolic blood pressure (SBP) target of 120 mm Hg is appropriate for people with hypertension, but this is debated particularly in people with multiple chronic conditions (MCC). We aimed to quantitatively determine whether benefits of a lower SBP target justify increased risks of harm in people with MCC, considering patient-valued outcomes and their relative importance. DESIGN: Highly stratified quantitative benefit-harm assessment based on various input data identified as the most valid and applicable from a systematic review of evidence and based on weights from a patient preference survey. SETTING: Outpatient care. PARTICIPANTS: Hypertensive patients, grouped by age, gender, prior history of stroke, chronic heart failure, chronic kidney disease and type 2 diabetes mellitus. INTERVENTIONS: SBP target of 120 versus 140 mm Hg for patients without history of stroke. PRIMARY AND SECONDARY OUTCOME MEASURES: Probability that the benefits of a SBP target of 120 mm Hg outweigh the harms compared with 140 mm Hg over 5 years (primary) with thresholds >0.6 (120 mm Hg better), <0.4 (140 mm Hg better) and 0.4 to 0.6 (unclear), number of prevented clinical events (secondary), calculated with the Gail/National Cancer Institute approach. RESULTS: Considering individual patient preferences had a substantial impact on the benefit-harm balance. With average preferences, 120 mm Hg was the better target compared with 140 mm Hg for many subgroups of patients without prior stroke, especially in patients over 75. For women below 65 with chronic kidney disease and without diabetes and prior stroke, 140 mm Hg was better. The analyses did not include mild adverse effects, and apply only to patients who tolerate antihypertensive treatment. CONCLUSIONS: For most patients, a lower SBP target was beneficial, but this depended also on individual preferences, implying individual decision-making is important. Our modelling allows for individualised treatment targets based on patient preferences, age, gender and co-morbidities.

A benefit-harm analysis of adding basal insulin vs. sulfonylurea to metformin to manage type II diabetes mellitus in people with multiple chronic conditions.

OBJECTIVES: The benefits and harms of diabetes treatments need to be carefully weighed in people with type II diabetes mellitus (DM) and multiple chronic conditions (MCCs). Our objective was to quantitatively assess the benefits and harms of the addition of basal insulin (insulin) vs. sulfonylurea (SU) to metformin in people with DM and MCCs. STUDY DESIGN AND SETTING: Data inputs into the benefit-harms analysis included (1) baseline risks of patient-centered outcomes (death, myocardial infarction, stroke, severe hypoglycemia, diarrhea, nausea) from cohorts and trials; (2) treatment effects for the addition of insulin vs. SU from a network meta-analysis; and (3) patient preference survey for outcome weights. Statistical analysis calculated the probability that adding insulin has greater benefits than harms, when compared with an SU, overall and by prespecified subgroups. RESULTS: Including the six outcomes, the probability of net benefit for insulin compared with SU was similar, across subgroups by age and diabetes duration (probability range, using conditional logit weights: 0.44-0.56). Adding patient preferences for treatment burden associated with insulin injections shifted the probability to favor SU over insulin (probability range, using conditional logit weights: 0.01-0.12). CONCLUSION: In people with DM and MCCs, we demonstrated incomplete evidence to conclude if basal insulin or SU should be added in people with DM and MCCs on metformin alone. The benefit-harm balance was sensitive to treatment preferences, that is., perceived treatment burden, indicating the importance of shared-decision making in caring for people with MCCs who are at high risk for experiencing harms associated with diabetes management.

Engaging Stakeholders to Inform Clinical Practice Guidelines That Address Multiple Chronic Conditions.

BACKGROUND: Having more than one chronic condition is common and is associated with greater health care utilization, higher medication burden and complexity of treatment. However, clinical practice guidelines (CPGs) do not routinely address the balance between harms and benefits of treatments for people with multiple chronic conditions (MCCs). OBJECTIVE: To partner with the Kaiser Permanente Integrated Cardiovascular Health (ICVH) program to engage multiple stakeholders in a mixed-methods approach in order to: 1) identify two high-priority clinical questions related to MCCs, and 2) understand patients' and family caregivers' perceptions of meaningful outcomes to inform benefit/harm assessments for these two high-priority questions. These clinical questions and outcomes will be used to inform CPG recommendations for people with MCCs. DESIGN AND PARTICIPANTS: The ICVH program provided 130 topics rank-ordered by the potential for finding evidence that would change clinical recommendations regarding the topic. We used a modified Delphi method to identify and reword topics into questions relevant to people with MCCs. We used two sets of focus groups (n = 27) to elicit patient and caregiver perspectives on two important research questions and relevant patient-important outcomes on benefit/harm balance for people with MCCs. KEY RESULTS: Co-investigators, patients and caregivers identified "optimal blood pressure goals" and "diabetes medication management" as important clinical topics for CPGs related to people with MCCs. Stakeholders identified a list of relevant outcomes to be addressed in future CPG development including 1) physical function and energy, 2) emotional health and well-being, 3) avoidance of treatment burden, side effects and risks, 4) interaction with providers and health care system, and 5) prevention of adverse long-term health outcomes. CONCLUSIONS: Through the application of a mixed-methods process, we identified the questions regarding optimal blood pressure goals and diabetes medication management, along with related patient-centered outcomes, to inform novel evidence syntheses for those with MCCs. This study provides the lessons learned and a generalizable process for CPG developers to engage patient and caregivers in priority-setting for the translation of evidence into future CPGs. Ultimately, engaging patient and stakeholders around MCCs could improve the relevance of CPGs for the care of people with MCCs.

ACC/AHA Special Report: Clinical Practice Guideline Implementation Strategies: A Summary of Systematic Reviews by the NHLBI Implementation Science Work Group: A Report of the American College of Cardiology/American Heart Association Task Force on Clinical Practice Guidelines.

BACKGROUND: In 2008, the National Heart, Lung, and Blood Institute convened an Implementation Science Work Group to assess evidence-based strategies for effectively implementing clinical practice guidelines. This was part of a larger effort to update existing clinical practice guidelines on cholesterol, blood pressure, and overweight/obesity. OBJECTIVES: Review evidence from the published implementation science literature and identify effective or promising strategies to enhance the adoption and implementation of clinical practice guidelines. METHODS: This systematic review was conducted on 4 critical questions, each focusing on the adoption and effectiveness of 4 intervention strategies: (1) reminders, (2) educational outreach visits, (3) audit and feedback, and (4) provider incentives. A scoping review of the Rx for Change database of systematic reviews was used to identify promising guideline implementation interventions aimed at providers. Inclusion and exclusion criteria were developed a priori for each question, and the published literature was initially searched up to 2012, and then updated with a supplemental search to 2015. Two independent reviewers screened the returned citations to identify relevant reviews and rated the quality of each included review. RESULTS: Audit and feedback and educational outreach visits were generally effective in improving both process of care (15 of 21 reviews and 12 of 13 reviews, respectively) and clinical outcomes (7 of 12 reviews and 3 of 5 reviews, respectively). Provider incentives showed mixed effectiveness for improving both process of care (3 of 4 reviews) and clinical outcomes (3 reviews equally distributed between generally effective, mixed, and generally ineffective). Reminders showed mixed effectiveness for improving process of care outcomes (27 reviews with 11 mixed and 3 generally ineffective results) and were generally ineffective for clinical outcomes (18 reviews with 6 mixed and 9 generally ineffective results). Educational outreach visits (2 of 2 reviews), reminders (3 of 4 reviews), and provider incentives (1 of 1 review) were generally effective for cost reduction. Educational outreach visits (1 of 1 review) and provider incentives (1 of 1 review) were also generally effective for cost-effectiveness outcomes. Barriers to clinician adoption or adherence to guidelines included time constraints (8 reviews/overviews); limited staffing resources (2 overviews); timing (5 reviews/overviews); clinician skepticism (5 reviews/overviews); clinician knowledge of guidelines (4 reviews/overviews); and higher age of the clinician (1 overview). Facilitating factors included guideline characteristics such as format, resources, and end-user involvement (6 reviews/overviews); involving stakeholders (5 reviews/overviews); leadership support (5 reviews/overviews); scope of implementation (5 reviews/overviews); organizational culture such as multidisciplinary teams and low-baseline adherence (9 reviews/overviews); and electronic guidelines systems (3 reviews). CONCLUSION: The strategies of audit and feedback and educational outreach visits were generally effective in improving both process of care and clinical outcomes. Reminders and provider incentives showed mixed effectiveness, or were generally ineffective. No general conclusion could be reached about cost effectiveness, because of limitations in the evidence. Important gaps exist in the evidence on effectiveness of implementation interventions, especially regarding clinical outcomes, cost effectiveness and contextual issues affecting successful implementation.

ACC/AHA Special Report: Clinical Practice Guideline Implementation Strategies: A Summary of Systematic Reviews by the NHLBI Implementation Science Work Group: A Report of the American College of Cardiology/American Heart Association Task Force on Clinical Practice Guidelines.

BACKGROUND: In 2008, the National Heart, Lung, and Blood Institute convened an Implementation Science Work Group to assess evidence-based strategies for effectively implementing clinical practice guidelines. This was part of a larger effort to update existing clinical practice guidelines on cholesterol, blood pressure, and overweight/obesity. OBJECTIVES: Review evidence from the published implementation science literature and identify effective or promising strategies to enhance the adoption and implementation of clinical practice guidelines. METHODS: This systematic review was conducted on 4 critical questions, each focusing on the adoption and effectiveness of 4 intervention strategies: (1) reminders, (2) educational outreach visits, (3) audit and feedback, and (4) provider incentives. A scoping review of the Rx for Change database of systematic reviews was used to identify promising guideline implementation interventions aimed at providers. Inclusion and exclusion criteria were developed a priori for each question, and the published literature was initially searched up to 2012, and then updated with a supplemental search to 2015. Two independent reviewers screened the returned citations to identify relevant reviews and rated the quality of each included review. RESULTS: Audit and feedback and educational outreach visits were generally effective in improving both process of care (15 of 21 reviews and 12 of 13 reviews, respectively) and clinical outcomes (7 of 12 reviews and 3 of 5 reviews, respectively). Provider incentives showed mixed effectiveness for improving both process of care (3 of 4 reviews) and clinical outcomes (3 reviews equally distributed between generally effective, mixed, and generally ineffective). Reminders showed mixed effectiveness for improving process of care outcomes (27 reviews with 11 mixed and 3 generally ineffective results) and were generally ineffective for clinical outcomes (18 reviews with 6 mixed and 9 generally ineffective results). Educational outreach visits (2 of 2 reviews), reminders (3 of 4 reviews), and provider incentives (1 of 1 review) were generally effective for cost reduction. Educational outreach visits (1 of 1 review) and provider incentives (1 of 1 review) were also generally effective for cost-effectiveness outcomes. Barriers to clinician adoption or adherence to guidelines included time constraints (8 reviews/overviews); limited staffing resources (2 overviews); timing (5 reviews/overviews); clinician skepticism (5 reviews/overviews); clinician knowledge of guidelines (4 reviews/overviews); and higher age of the clinician (1 overview). Facilitating factors included guideline characteristics such as format, resources, and end-user involvement (6 reviews/overviews); involving stakeholders (5 reviews/overviews); leadership support (5 reviews/overviews); scope of implementation (5 reviews/overviews); organizational culture such as multidisciplinary teams and low-baseline adherence (9 reviews/overviews); and electronic guidelines systems (3 reviews). CONCLUSION: The strategies of audit and feedback and educational outreach visits were generally effective in improving both process of care and clinical outcomes. Reminders and provider incentives showed mixed effectiveness, or were generally ineffective. No general conclusion could be reached about cost effectiveness, because of limitations in the evidence. Important gaps exist in the evidence on effectiveness of implementation interventions, especially regarding clinical outcomes, cost effectiveness and contextual issues affecting successful implementation.

An improved ultra performance liquid chromatography-tandem mass spectrometry method for the determination of alloisoleucine and branched chain amino acids in dried blood samples.

BACKGROUND: Branched chain amino acid (BCAA) analysis is needed for the diagnosis and management of patients with maple syrup urine disease (MSUD). We report an improved ultra performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) method for the determination of BCAAs and Allo-Ile in dried blood spot (DBS) samples. METHODS: BCAAs were extracted from a 3 mm blood spot into methanol/water containing stable isotope internal standards. Eluents were dried and reconstituted in the mobile phase. Gradient elution was performed on an Acquity™ BEH C(18) (100 × 2.1 mm, 1.7 µm) column. BCAAs were detected and quantified in the multiple reaction monitoring mode in a five-minute analysis. RESULTS: The assay was calibrated to give best possible alignment with plasma results. Retrospective analysis of newborn DBSs from six classic MSUD patients showed elevated alloisoleucine (Allo-Ile) in all cases. Two of four patients with mild disease had normal values; the other two had significant elevations in Allo-Ile. CONCLUSIONS: Analysis of BCAA in DBS by UPLC-MS/MS is a useful second tier newborn screening test to identify classical MSUD and for monitoring of remote patients.

Glutaric aciduria type I: outcome following detection by newborn screening.

Glutaric aciduria type I (GA I), a cerebral organic acidaemia with the potential for severe neurological consequences, can now be detected by tandem mass spectrometry newborn screening. Early detection with implementation of careful management strategies appears to lessen the likelihood of neurological damage. We assessed the outcome in all 10 GA I patients detected in New South Wales during the last decade. Three patients were detected clinically and 7 by newborn screening. Diagnosis was confirmed by detection of significantly elevated urinary 3-hydroxybutyrate and glutarate in urine, isolated elevation of glutarylcarnitine in plasma, typical clinical and MRI findings in several, and mutation analysis or enzyme analysis on cultured skin fibroblasts in 4 cases. The birth frequency was 1:90,000. Following diagnosis, treatment was initiated in all children with oral carnitine (100 mg/kg per day) and a low-protein diet supplemented with a lysine-free, low-tryptophan amino acid formula. Disability was assessed in fields of motor, cognitive and speech development and scored according to Kyllerman. Clinically diagnosed patients were all symptomatic, with severity scores (out of 9) of 3, 5 and 9. Six of seven patients detected by newborn screening are asymptomatic, 4 being aged 2-6 years. One patient had a severe decompensation at 7 months, despite full management advice and treatment, and later died. Our data support previous findings that early diagnosis reduces neurological complications, but show that even with early diagnosis and careful management severe complications may ensue in some.

Non-ketotic hyperglycinemia is usually not detectable by tandem mass spectrometry newborn screening.

Diagnosis of Non-Ketotic Hyperglycinemia by MSMS newborn screening might benefit patients with post-neonatal presentation. We screened 733,527 babies over eight years, and nine babies were subsequently diagnosed with NKHG. Two had newborn glycine levels above our cut-off and presented within 72 h. The remaining patients could not have been diagnosed by newborn screening without an unacceptably high recall rate. We conclude that babies with NKHG are not usually identifiable by current newborn screening strategies.

Newborn screening may fail to identify intermediate forms of maple syrup urine disease.

The New South Wales state-wide newborn screening programme has offered comprehensive screening for inborn errors of metabolism, including MSUD, using electrospray tandem mass spectrometry since 1998. Over this period, a number of patients with classic MSUD have been identified with subsequent good neurological outcome. We describe two patients with an intermediate form of MSUD who presented later in childhood. Retrospective review of their newborn screening results demonstrates that the diagnosis could not have been made by current newborn screening. Their neurological outcome is much less satisfactory. Despite the usefulness of expanded newborn screening programmes in detecting severe neonatal presentations of inborn errors of metabolism, partial enzyme deficiencies may not be detected. Metabolic diseases still need to be considered in appropriate clinical situations later in life.

Pseudo-glutarylcarnitinaemia in medium-chain acyl-CoA dehydrogenase deficiency detected by tandem mass spectrometry newborn screening.

As well as characteristic increases in C(8) carnitine, dried blood spot samples from 11 newborns with medium-chain acyl-CoA dehydrogenase deficiency detected by tandem mass spectrometry screening using butyl esters showed apparent increases in glutarylcarnitine (m / z 388 signals). In four of the newborns in which it was measured, apparent increases in malonylcarnitine (m / z 360) were also detected. It was shown that the apparent increases were caused by interfering acylcarnitines, putatively identified as hydroxyoctanoylcarnitine and hydroxydecanoylcarnitine, respectively, using alternative derivatives for tandem mass spectrometry. Levels of the two abnormal carnitines correlated with C(8) carnitine levels and normalized with repeat testing in 10 cases. These results indicated that the abnormal carnitines were significantly elevated only during periods of increased fatty acid catabolism, as may occur in the immediate postnatal period.

Evaluation of newborn screening for medium chain acyl-CoA dehydrogenase deficiency in 275 000 babies.

OBJECTIVE: To evaluate newborn screening by tandem mass spectrometry for detection of medium chain acyl-CoA dehydrogenase (MCAD) deficiency, a fatty acid oxidation disorder with significant mortality in undiagnosed patients. DESIGN: The following were studied: (a) 13 clinically detected MCAD deficient subjects, most homozygous for the common A985G mutation, whose newborn screening sample was available; (b) 275 653 consecutive neonates undergoing routine newborn screening. Screened infants with blood octanoylcarnitine levels > or = 1 micromol/l were analysed for the A985G mutation, had analysis of plasma and repeat blood spot acylcarnitines and urinary organic acids, and had fibroblast fatty acid oxidation or acylcarnitine studies. RESULT: Twelve of the 13 patients later diagnosed clinically had newborn octanoylcarnitine levels > 2.3 micromol/l. Twenty three screened babies had initial octanoylcarnitine levels > or = 1 micromol/l. Eleven of 12 babies with persistent abnormalities had metabolite and/or enzyme studies indicating MCAD deficiency. Only four were homozygous for the A985G mutation, the remainder carrying one copy. CONCLUSIONS: Most patients with symptomatic MCAD deficiency could be detected by newborn screening. Infants actually detected had a lower frequency of A985G alleles than clinically diagnosed cases and may have a lower risk of becoming symptomatic.

Carnitine palmitoyltransferase I deficiency in neonate identified by dried blood spot free carnitine and acylcarnitine profile.

A neonate at risk for hepatic carnitine palmitoyltransferase I (L-CPT I) deficiency was investigated from birth. The free carnitine and acylcarnitine profile in dried whole blood filter paper samples collected at ages 1 and 4 days showed a markedly elevated concentration of free carnitine (141 and 142 micromol/L, respectively), normal concentrations of acetyl- and propionylcarnitine, with the near absence of all other species. The diagnosis was confirmed by in vitro fatty acid oxidation screening assays and enzyme assay in cultured skin fibroblasts. Retrospective study of the newborn whole blood sample of the index case showed a similar profile (free carnitine 181 micromol/L). The newborn population distribution of free carnitine (n = 143,981) showed that only three samples had free carnitine > 140 micromol/L (>99.9th centile), two were from L-CPT I-deficient neonates and one from a baby with sepsis. While there are other conditions that can cause elevated concentrations of free carnitine, an isolated elevation of free carnitine only in an apparently healthy term neonate warrants further investigation to exclude L-CPT I deficiency.

Carnitine transporter defect diagnosed by newborn screening with electrospray tandem mass spectrometry.

The carnitine transporter defect is a potentially fatal but treatable disorder. We used electrospray tandem mass spectrometry in the New South Wales (Australia) Newborn Screening Programme to measure free carnitine and acylcarnitine species in the newborn population. Free carnitine levels in dried blood samples from 149,000 neonates did not vary markedly between 2 and 8 days of age. Two of 4 babies subsequently diagnosed clinically with the carnitine transporter defect had a free carnitine level in the neonatal blood sample low enough to be detected by screening.

Pancreatic function and extended mutation analysis in DeltaF508 heterozygous infants with an elevated immunoreactive trypsinogen but normal sweat electrolyte levels.

BACKGROUND: Newborn screening for cystic fibrosis (CF) with immunoreactive trypsinogen (IRT) and DeltaF508 analysis followed by sweat testing misses some infants with CF and detects more DeltaF508 carriers than expected. Some of the apparent DeltaF508 carriers may be DeltaF508 compound heterozygotes with normal sweat electrolyte levels. METHODS: Infants identified by newborn screening with an elevated IRT level, one DeltaF508 allele, and a sweat chloride level <60 mmol/L underwent CF mutation analysis, pancreatic stimulation testing, and repeat IRT analysis followed by clinical review and repeat sweat test at 12 months. RESULTS: Over a 24-month period we identified 122 DeltaF508 heterozygotes and recruited 57; 4 had borderline sweat chloride levels (40 to 60 mmol/L), 5 (8.8%, 95% CI 1.4, 16.2) had a second CF mutation (R117H), and 11 (20%, 95% CI 10, 30) had the intron 8 5T allele. Three had clinical CF at 12 months (initial sweat chloride levels: 53, 51, and 32 mmol/L). Pancreatic electrolyte secretion in the subjects with a borderline sweat chloride level was similar to that in patients with known CF. CONCLUSION: The excess of DeltaF508 heterozygotes detected by IRT/DNA screening is associated with the presence of a second mutation or the 5T allele in some infants. Screened infants with borderline sweat chloride levels almost certainly have CF, but long-term follow-up of the infants with the genotype DeltaF508/R117H and DeltaF508/5T is required to determine their outcome. In the meantime, newborn screening should be confined to severe mutations associated with classic CF.

Newborn screening with tandem mass spectrometry: 12 months' experience in NSW Australia.

Since 1998, the NSW Newborn Screening Program has used electrospray tandem mass spectrometry (MS/MS) to analyse samples from all babies born in NSW and the ACT (approximately 95000 per year) for selected amino acids and acylcarnitines. The software rules editor initially interprets all results where ratio of analyte to internal standard is modified by input from the external standard curves per analyte. The numerical results are then downloaded to the NSW Newborn Screening database, which provides automatic, analyte specific follow-up test cascade. We have analysed samples from 137 120 consecutive newborns received by the program, requested repeat samples from 122 babies, and found abnormal levels in 17 babies with phenylketonuria, 1 tetrahydrobiopterin deficiency, 3 hyperphenylalaninaemia, 1 maple syrup urine disease, 1 tyrosinaemia type II, 1 congenital lactic acidosis, 2 medium-chain acyl CoA dehydrogenase deficiency, 1 short-chain acyl CoA dehydrogenase deficiency, 1 beta-ketothiolase deficiency, 2 vitamin B12 deficient babies of vegan mothers and 1 glutaric aciduria type I. Using population data plus that obtained from retrospective samples with proven disorders we have established cut-off levels for each analyte tested. This coupled with the ability of the database to provide ratios of various analytes gives excellent screening specificity and sensitivity for the detection of at least 40 rare inborn errors of metabolism.

Cation binding to the integrin CD11b I domain and activation model assessment.

BACKGROUND: The integrin family of cell-surface receptors mediate cell adhesion through interactions with the extracellular matrix or other cell-surface receptors. The alpha chain of some integrin heterodimers includes an inserted 'I domain' of about 200 amino acids which binds divalent metal ions and is essential for integrin function. Lee et al. proposed that the I domain of the integrin CD11b adopts a unique 'active' conformation when bound to its counter receptor. In addition, they proposed that the lack of adhesion in the presence of Ca2+ ion reflected the stabilization of an 'inactive' I-domain conformation. We set out to independently determine the structure of the CD11 b I domain and to evaluate the structural effects of divalent ion binding to this protein. RESULTS: We have determined the X-ray structure of a new crystal form of the CD11 b I domain in the absence of added metal ions by multiple isomorphous replacement (MIR). Metal ions were easily introduced into this crystal form allowing the straight-forward assessment of the structural effects of divalent cation binding at the metal ion dependent adhesion site (MIDAS). The equilibrium binding constants for these ions were determined by titration calorimetry. The overall protein conformation and metal-ion coordination of the I domain is the same as that observed for all previously reported CD11 a I-domain structures and a CD11 b I-domain complex with Mn2+. These structures define a majority conformation. CONCLUSIONS: Addition of the cations Mg2+, Mn2+ and Cd2+ to the metal-free I domain does not induce conformational changes in the crystalline environment. Moreover, we find that Ca2+ binds poorly to the I domain which serves to explain its failure to support adhesion. We show that the active conformation proposed by Lee et al, is likely to be a construct artifact and we propose that the currently available data do not support a dramatic structural transition for the I domain during counter-receptor binding.

Biosynthesis of marcfortine A.

This report describes the results of a biosynthesis study of marcfortine A (MA). We report here that MA is derived from methionine, tryptophan, lysine and two isoprene units, the latter two being derived from acetic acid. From the 13C enrichment pattern of the pipecolic acid moeity we further conclude that this unit is derived from lysine via alpha-ketoglutarate. Therefore, we have accounted for the biogenesis of every carbon atom of MA and established the biosynthetic pathway for the pipecolic acid moiety of MA.