Left Atrial Appendage Ligation Using the AtriClip Device: Single-Center Study of Device Safety and Efficacy

OBJECTIVE

Left atrial appendage (LAA) occlusion at the time of cardiac surgery in patients with atrial fibrillation has been shown to reduce the incidence of postoperative embolic stroke. However, the optimal method for LAA occlusion is not universally accepted. We sought to examine the safety and effectiveness of LAA occlusion with the AtriClip epicardial occlusion device.

METHODS

Cardiac surgical patients with atrial fibrillation who underwent LAA AtriClip placement were evaluated prospectively. Clip placement and clinical outcomes were examined after 1 year of follow-up with transesophageal echocardiography (TEE). The presence of a 10 mm or greater residual pouch, presence of flow into the LAA, or device-related thrombus (DRT) were considered failures.

RESULTS

Ninety-seven patients were analyzed. The mean CHA₂DS₂-VASc score was 2.4 ± 1.4. The postoperative follow-up period ranged from 366 to 1,693 days (mean 685 days or 1.87 years). Seventy-four AtriClips were placed with video-assisted thoracic surgery, whereas 23 were placed via sternotomy or thoracotomy. Successful closure was found in 96% (93 of 97) of patients at follow-up. Failure occurred in 4 patients. No clip migration or DRT was seen on 3-dimensional imaging. Of all 97 patients, 76 (78%) were on presurgical oral anticoagulation, whereas 5 (5.1%) were on postprocedure oral anticoagulation. There were no postoperative thromboembolic events at the time of the study TEE.

CONCLUSIONS

The AtriClip epicardial surgical occlusion device can provide an excellent rate of successful closure of the LAA during surgical ablation procedures without DRT.

How Long Before a Second Defoliation of Actively Growing Grass Plants in the Desert Grassland?

In the Desert Grassland, second and subsequent defoliations on perennial grasses during the active growing season can have substantial impacts on grass recovery and reproduction following herbivory. Land managers implement tactics to avoid multiple defoliations on plants by way of rotational grazing, reduced stocking rates, and/or reduced time spent within a given pasture. We explored frequency and rate of defoliation by cattle on perennial bunchgrasses within an 11-day grazing period in three pastures including distance to water (300 and 600 m) and plant height to determine their influence on animal diet selection. Results indicate that 32% of all marked plants were defoliated by cattle and only 5% of defoliated plants were defoliated a second time by day 10 of the grazing period. Defoliation patterns in the studied pastures did not differ between two distances from water, or in relation to plant height. However, at the second defoliation cattle grazed plants that were shorter than at the first defoliation suggesting a selection for high quality re-growth over larger forage on offer. The results of this study show that a 10-day grazing period during the growing season of the Desert Grassland is an effective strategy to avoid second defoliations on individual perennial grass plants while maintaining sufficient forage for use during the dormant winter grazing season.

Dust Sources in the Salton Sea Basin: A Clear Case of an Anthropogenically Impacted Dust Budget

The Salton Sea Basin in California suffers from poor air quality, and an expanding dry lakebed (playa) presents a new potential dust source. In 2017-18, depositing dust was collected approximately monthly at five sites in the Salton Sea Basin and analyzed for total elemental and soluble anion content. These data were analyzed with Positive Matrix Factorization (PMF). The PMF method resolved seven dust sources with distinct compositional markers: Playa (Mg, SO₄^2-, Na, Ca, Sr), Colorado Alluvium (U, Ca), Local Alluvium (Al, Fe, Ti), Agricultural Burning (K, PO₄^3-), Sea Spray (Na, Cl^-, Se), Anthropogenic Trace Metals (Sb, As, Zn, Cd, Pb, Na), and Anthropogenic Copper (Cu). All sources except Local Alluvium are influenced or caused by current or historic anthropogenic activities. PMF attributed 55 to 80% of the measured dust flux to these six sources. The dust fluxes at the site where the playa source was dominant (89 g m^-2 yr^-1) were less than, but approaching the scale of, those observed at Owens Lake playas in the late 20th century. Playa emissions in the Salton Sea region were most intense during the late spring to early summer and contain high concentrations of evaporite mineral tracers, particularly Mg, Ca, and SO₄^2-.

Identifying areas for improvement in paediatric trauma care in NSW Australia using a clinical, system and human factors peer-review tool

BACKGROUND

There is known variability in the quality of care delivered to injured children. Identifying where care improvement can be made is critical. This study aimed to review paediatric trauma cases across the most populous Australian State to identify factors contributing to clinical incidents.

METHODS

Medical records from three New South Wales Paediatric Trauma Centres were reviewed for children <16 years requiring intensive care; with an injury severity score of ≥9, or who died following injury between July 2015 and September 2016. Records were peer-reviewed by nurse surveyors who identified cases that might not meet the expected standard of care or where the child died following the injury. A multidisciplinary panel conducted the peer-review using a major trauma peer-review tool. Records were reviewed independently, then discussed to establish consensus.

RESULTS

A total 535 records were reviewed and 41 cases were peer-reviewed. The median (IQR) age was 7 (2-12) years, the median ISS was 25 (IQR 16-30). The peer-review identified a combination of clinical (85%), systems (51%) and communication (12%) problems that contributed to difficulties in care delivery. In 85% of records, staff actions were identified to contribute to events; with medical task failure the most frequently identified cause (89%).

CONCLUSION

The peer-review of paediatric trauma cases assisted in the identification of contributing factors to clinical incidents in trauma care resulting in 26 recommendations for change. The prioritisation and implementation of these recommendations, alongside a uniform State-wide trauma case review process with consistent criteria (definitions), performance indicators, monitoring and reporting would facilitate improvement in health service delivery to children sustaining severe injury.

Oxidative Stress and Cardiovascular Risk in Type 1 Diabetes Mellitus: Insights From the DCCT/EDIC Study

Background

Hyperglycemia leading to increased oxidative stress is implicated in the increased risk for the development of macrovascular and microvascular complications in patients with type 1 diabetes mellitus.

Methods and Results

A random subcohort of 349 participants was selected from the DCCT / EDIC (Diabetes Control and Complications Trial/Epidemiology of Diabetes Interventions and Complications) cohort. This included 320 controls and 29 cardiovascular disease cases that were augmented with 98 additional known cases to yield a case cohort of 447 participants (320 controls, 127 cases). Biosamples from DCCT baseline, year 1, and closeout of DCCT , and 1 to 2 years post‐ DCCT ( EDIC years 1 and 2) were measured for markers of oxidative stress, including plasma myeloperoxidase, paraoxonase activity, urinary F 2α isoprostanes, and its metabolite, 2,3 dinor‐8 iso prostaglandin F 2α . Following adjustment for glycated hemoblobin and weighting the observations inversely proportional to the sampling selection probabilities, higher paraoxonase activity, reflective of antioxidant activity, and 2,3 dinor‐8 iso prostaglandin F 2α , an oxidative marker, were significantly associated with lower risk of cardiovascular disease (−4.5% risk for 10% higher paraoxonase, P <0.003; −5.3% risk for 10% higher 2,3 dinor‐8 iso prostaglandin F 2α , P =0.0092). In contrast, the oxidative markers myeloperoxidase and F 2α isoprostanes were not significantly associated with cardiovascular disease after adjustment for glycated hemoblobin. There were no significant differences between DCCT intensive and conventional treatment groups in the change in all biomarkers across time segments.

Conclusions

Heightened antioxidant activity (rather than diminished oxidative stress markers) is associated with lower cardiovascular disease risk in type 1 diabetes mellitus, but these biomarkers did not change over time with intensification of glycemic control.

Clinical Trial Registration

URL : https://www.clinicaltrials.gov . Unique identifiers: NCT 00360815 and NCT 00360893.

Effects of maternal diabetes and fetal sex on human placenta mitochondrial biogenesis

Abnormal placental function in maternal diabetes affects fetal health and can predispose offspring to metabolic diseases in later life. There are fetal sex-specific differences in placenta structure and gene expression, which may affect placental responses to maternal diabetes. The present study examined the effects of maternal diabetes on indices of mitochondrial biogenesis in placentae from male and female offspring. Mitochondrial DNA (mtDNA) copy number and expression of key regulators of mitochondrial biogenesis were assessed in placentae from 19 diabetic and 23 non-diabetic women. The abundance of peroxisome proliferator-activated receptor-γ coactivator-1α (PGC-1α) and mitochondria transcription factor A (TFAM) were lower in female placentae compared to males, but not mtDNA content. In male offspring, maternal diabetes was associated with decreased placental PGC-1α and TFAM, and mitochondrial DNA (mtDNA) content. Male placental TFAM levels were highly correlated with PGC-1α and mtDNA content. However, despite decreased PGC-1α, concomitant changes in TFAM and mtDNA content by diabetes were not observed in females. In addition, TFAM abundance in female placentae was not correlated with PGC-1α or mtDNA content. In summary, placental PGC-1α/TFAM/mitochondrial biogenesis pathway is affected by maternal diabetes and offspring sex. Decreased PGC-1α in response to maternal diabetes plausibly contributes to impaired mitochondrial biogenesis in placentae of male offspring, which may affect long-term health and explain some of enhanced risk of future metabolic diseases in males.

Methane seep carbonates yield clumped isotope signatures out of equilibrium with formation temperatures

Methane cold seep systems typically exhibit extensive buildups of authigenic carbonate minerals, resulting from local increases in alkalinity driven by methane oxidation. Here, we demonstrate that modern seep authigenic carbonates exhibit anomalously low clumped isotope values (Δ₄₇), as much as ∼0.2‰ lower than expected values. In modern seeps, this range of disequilibrium translates into apparent temperatures that are always warmer than ambient temperatures, by up to 50 °C. We examine various mechanisms that may induce disequilibrium behaviour in modern seep carbonates, and suggest that the observed values result from several factors including kinetic isotopic effects during methane oxidation, mixing of inorganic carbon pools, pH effects and rapid precipitation. Ancient seep carbonates studied here also exhibit potential disequilibrium signals. Ultimately, these findings indicate the predominance of disequilibrium clumped isotope behaviour in modern cold seep carbonates that must be considered when characterizing environmental conditions in both modern and ancient cold seep settings.

The geochemistry of methane cold seep carbonates is often used to reconstruct environmental conditions. Loyd et al. find disequilibrium clumped isotope compositions in modern seep carbonates that suggest temperatures up to 50°C too high, raising doubt on seep carbonate temperature reconstructions.

Abstract OT3-02-03: An observational study of dose dense chemotherapy with lipegfilgrastim support in early breast cancer

Background: The combination of the anthracycline, doxorubicin with cyclophosphamide (AC) is a widely used chemotherapy regimen in early stage breast cancer. Studies have shown that dose dense chemotherapy (incorporating AC) improved both disease-free survival and overall survival compared to once every 3 week treatment with daily subcutaneous G-CSF support. An important advance in the use of dose dense chemotherapy regimens was the development of pegylated forms of G-CSF, which offered the convenience of a single subcutaneous injection, rather than multiple daily injections. Lipegfilgrastim is a pegylated long-acting covalent conjugate of filgrastim (G-CSF). In a pivotal randomised phase III study in breast cancer lipegfilgrastim was shown to be non-inferior to pegfilgrastim. Although lipegfilgrastim is licensed in Europe and can facilitate every 2 week (dose dense) scheduling of chemotherapy there are a lack of prospective data about its efficacy in this setting. In this prospective, non-interventional, study we are investigating the incidence of treatment-related neutropaenia following four cycles of dose dense AC with lipegfilgrastim support.

Methods: The primary end point of this prospective, single arm study is to determine the incidence of treatment-related neutropaenia, defined as an absolute neutrophil count (ANC) of &lt;1.0 x 109/L, following four cycles of dose dense AC with lipegfilgrastim support. The secondary end points are to (1) determine the incidence of febrile neutropaenia, defined as temperature &gt; 38°C and ANC &lt;1.0 x 109/L, during 4 cycles of dose dense AC with lipegfilgrastim and (2) examine the incidence of treatment-related neutropaenia during subsequent intravenous chemotherapy post completion of AC. Eligibility criteria include, patients with stage I-III breast cancer, planned treatment with dose dense AC in the adjuvant or neoadjuvant setting, age ≥ 18 years, Eastern Cooperative Oncology Group (ECOG) Performance Status 0-1 and adequate bone marrow function. Patients with prior exposure to chemotherapy and/or G-CSF, who are pregnant, have a cardiac or other concurrent illness, which at the investigator's discretion contraindicates the use of AC will be excluded. We will enrol 40 consecutive patients who are planned to undergo dose dense AC. Based on previous clinical trials, we expect that the incidence of treatment-related neutropaenia will be &lt;12%. However, it is likely that the current study will more closely resemble real-world practice and a higher incidence of treatment-related neutropaenia may be observed. This study has been approved by the Instituational Review Board and 9 patients have been consented to date. (registered with clinicaltrials.gov).

Citation Format: Lyons T, Mallet V, Collins D, Malone E, Milewski M, Egan K, Hennessy B, Grogan L, Breathnach O, Morris P. An observational study of dose dense chemotherapy with lipegfilgrastim support in early breast cancer. [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr OT3-02-03.

Lower resting energy expenditure and fat oxidation in Native American and Hispanic infants born to mothers with diabetes

OBJECTIVE

To determine whether exposure to diabetes in utero affects resting energy expenditure (REE) and fuel oxidation in infants.

STUDY DESIGN

At 35 ± 5 days after birth, body composition and REE were measured in full-term offspring of Native American and Hispanic women with either well-controlled diabetes (13 girls, 11 boys) or normal healthy pregnancies (18 girls, 17 boys).

RESULTS

Control of dysglycemia during gestation in the women with diabetes mellitus met current clinical standards, shown by average glycated hemoglobin (5.9 ± 0.2%; 40.6 ± 2.3 mmol/mol). Infant body mass (offspring of women with diabetes: 4.78 ± 0.13, control offspring: 4.56 ± 0.08 kg) and body fatness (offspring of women with diabetes: 25.2 ± 0.6, control offspring: 24.2 ± 0.5 %) did not differ between groups. REE, adjusted for lean body mass, was 14% lower in offspring of women with diabetes (41.7 ± 2.3 kJ/h) than control offspring (48.6 ± 2.0, P = .025). Fat oxidation was 26% lower in offspring of women with diabetes (0.54 ± 0.05 g/h) than control offspring (0.76 ± 0.04, P < .01) but carbohydrate oxidation did not differ. Thus, fat oxidation accounted for a lower fraction of REE in the offspring of women with diabetes (49 ± 4%) than control offspring (60 ± 3%, P = .022). Mothers with diabetes were older and had higher prepregnancy body mass index than control mothers.

CONCLUSIONS

Well-controlled maternal diabetes did not significantly affect body mass or composition of offspring at 1-month old. However, infants with mothers with diabetes had reduced REE and fat oxidation, which could contribute to adiposity and future disease risk. Further studies are needed to assess the impact differences in age and higher prepregnancy body mass index.

Vismodegib in the treatment of advanced BCC

Basal-cell carcinoma (BCC) is the most commonly diagnosed malignancy, comprising over 80 per thousand of non-melanoma skin cancers. Surgical excision is adequate treatment for most BCC's. Options are however limited for the minority of patients presenting with locally advanced inoperable or metastatic BCC. The Hedgehog signalling pathway is a critical driver in the pathogenesis of both sporadic and hereditary BCC. On 31st January 2012, based on a phase II clinical trial the US Food and Drug Administration approved Vismodegib (Erivedge, Roche) a first-in-class, small-molecule oral Hedgehog-inhibitor for the treatment of locally advanced inoperable and metastatic BCC. We present our experience treating the first Irish patient with this agent.

Oxidative and endoplasmic reticulum stresses mediate apoptosis induced by modified LDL in human retinal Müller cells

PURPOSE

We previously showed that extravasated, modified LDL is implicated in pericyte loss in diabetic retinopathy (DR). Here, we investigate whether modified LDL induces apoptosis in retinal Müller glial cells.

METHODS

Cultured human retinal Müller cells (MIO-M1) were treated with highly oxidized glycated LDL (HOG-LDL, 200 mg protein/L) or native LDL (N-LDL, 200 mg protein/L) for up to 24 hours with or without pretreatment with N-acetyl-cysteine (NAC, a blocker of oxidative stress) and 4-phenylbutyrate (4-PBA, a blocker of endoplasmic reticulum [ER] stress). Effects of HOG-LDL on cell viability, apoptosis, oxidative stress, and ER stress were assessed by cell viability, TUNEL, and Western blot assays. In separate experiments, Müller cells were treated with 7-ketocholesterol (7-KC, 5-20 μM) or 4-hydroxynonenal (4-HNE, 5-40 μM) for up to 24 hours. The same markers were measured.

RESULTS

HOG-LDL induced apoptosis (decreased cell viability, increased TUNEL staining, increased expression of cleaved PARP, cleaved caspase-3, and BAX; decreased Bcl-2), oxidative stress (increased NOX4 and antioxidant enzymes, catalase, and superoxide dismutase 2), and ER stress (increased phospho-eIF2α, KDEL, ATF6, and CHOP). Pretreatment with NAC or 4-PBA partially attenuated apoptosis. In addition. NAC attenuated activation of ER stress. Similar to HOG-LDL, 7KC, and 4HNE also induced apoptosis, oxidative stress, and ER stress.

CONCLUSIONS

Our data suggest that extravasated, modified lipoproteins may be implicated in apoptotic Müller cell death, acting at least partially via enhanced levels of oxidative and ER stresses. They support our main hypothesis that, in addition to hyperglycemia, extravasated and oxidized LDL is an important insult to the diabetic retina.

Self-reported psychological distress associated with steroid therapy for HIV

Anabolic androgenic steroid (AAS) replacement therapy is standard care for patients with low testosterone, including HIV-related conditions. These medications have been associated with development of aggressiveness, anxiety disorders, and depression, but only in short-term clinical trials. We conducted an anonymous street survey at a gay and lesbian community event and a survey in a clinic-based setting to study the wider prevalence of psychiatric side-effects associated with androgenic steroids. In the street-based survey, almost half of those prescribed AAS reported psychological side-effects, most commonly aggression (29%) followed by depression (21%). In the clinic survey of mostly HIV+ male patients, changes in sex drive were the most commonly reported effect of treatment while impulsive aggression, anxiety and depression were reported at levels similar to those in the street fair survey. These findings suggest that AAS therapy may be more frequently associated with distress than has been reported in the clinical literature.

Epidemiology of traumatic deaths: comprehensive population-based assessment

BACKGROUND

The epidemiology of traumatic deaths was periodically described during the development of the American trauma system between 1977 and 1995. Recognizing the impact of aging populations and the potential changes in injury mechanisms, the purpose of this work was to provide a comprehensive, prospective, population-based study of Australian trauma-related deaths and compare the results with those of landmark studies.

METHODS

All prehospitalization and in-hospital trauma deaths occurring in an inclusive trauma system at a single Level 1 trauma center [400 patients with an injury severity score (ISS) >15/year] underwent autopsy and were prospectively evaluated during 2005. High-energy (HE) and low-energy (LE) deaths were categorized based on the mechanism of the injury, time frame (prehospitalization, <48 hours, 2-7 days, >7 days), and cause [which was determined by an expert panel and included central nervous system-related (CNS), exsanguination, CNS + exsanguination, airway, multiple organ failure (MOF)]. Data are presented as a percent or the mean +/- SEM.

RESULTS

There were 175 deaths during the 12-month period. For the 103 HE fatalities (age 43 +/- 2 years, ISS 49 +/- 2, male 63%), the predominant mechanisms were motor vehicle related (72%), falls (4%), gunshots (8%), stabs (6%), and burns (5%). In all, 66% of the patients died during the prehospital phase, 27% died after <48 hours in hospital, 5% died after 3 to 7 days in hospital, and 2% died after >7 days. CNS (33%) and exsanguination (33%) were the most common causes of deaths, followed by CNS + exsanguination (17%) and airway compromise 8%; MOF occurred in only 3%. Six percent of the deaths were undetermined. All LE deaths (n = 72, age 83 +/- 1 years, ISS 14 +/- 1, male 45%) were due to low falls. All LE patients died in hospital (20% <48 hours, 32% after 3-7 days, 48% after 7 days). The causes of deaths were head injury (26%) and complications of skeletal injuries (74%).

CONCLUSIONS

The HE injury mechanisms, time frames, and causes in our study are different from those in the earlier, seminal reports. The classic trimodal death distribution is much more skewed to early death. Exsanguination became as frequent as lethal head injuries, but the incidence of fatal MOF is lower than reported earlier. LE trauma is responsible for 41% of the postinjury mortality, with distinct epidemiology. The LE group deserves more attention and further investigation.

Consequences of unlocking the cardiac myosin molecule in human myocarditis and cardiomyopathies

Myocarditis, often initiated by viral infection, may progress to autoimmune inflammatory heart disease, dilated cardiomyopathy and heart failure. Although cardiac myosin is a dominant autoantigen in animal models of myocarditis and is released from the heart during viral myocarditis, the characterization, role and significance of anti-cardiac myosin autoantibodies is poorly defined. In our study, we define the human cardiac myosin epitopes in human myocarditis and cardiomyopathies and establish a mechanism to explain how anti-cardiac myosin autoantibodies may contribute to heart disease. We show that autoantibodies to cardiac myosin in sera from myocarditis and dilated cardiomyopathies in humans targeted primarily epitopes in the S2 hinge region of cardiac myosin. In addition, anti-cardiac myosin antibodies in sera or purified IgG from myocarditis and cardiomyopathy targeted the beta-adrenergic receptor and induced antibody-mediated cAMP-dependent protein kinase A (PKA) cell signaling activity in heart cells. Antibody-mediated PKA activity in sera was abrogated by absorption with anti-human IgG. Antibody-mediated cell signaling of PKA was blocked by antigen-specific inhibition by human cardiac myosin or the beta-adrenergic receptor but not the alpha adrenergic receptor or bovine serum albumin. Propranolol, a beta blocker and inhibitor of the beta-adrenergic receptor pathway also blocked the antibody-mediated signaling of the beta-adrenergic receptor and PKA. The data suggest that IgG antibody against human cardiac myosin reacts with the beta-adrenergic receptor and triggers PKA signaling in heart cells. In summary, we have identified a new class of crossreactive autoantibodies against human cardiac myosin and the beta-adrenergic receptor in the heart. In addition, we have defined disease specific peptide epitopes in the human cardiac myosin rod S2 region in human myocarditis and cardiomyopathy as well as a mechanistic role of autoantibody in the pathogenesis of disease.

Increased serum pigment epithelium derived factor levels in Type 2 diabetes patients

Serum PEDF levels (mean (S.D.)) were increased in 96 Type 2 diabetic vs. 54 non-diabetic subjects; 5.3 (2.8) vs. 3.2 (2.0)mug/ml, p<0.001. In diabetes, PEDF correlated with BMI, serum creatinine and LDL-cholesterol, but not with other lipids, HbA1c or CRP. PEDF did not differ by drugs, complications, or gender.

Activation of protease calpain by oxidized and glycated LDL increases the degradation of endothelial nitric oxide synthase

Oxidation and glycation of low-density lipoprotein (LDL) promote vascular injury in diabetes; however, the mechanisms underlying this effect remain poorly defined. The present study was conducted to determine the effects of ‘heavily oxidized’ glycated LDL (HOG-LDL) on endothelial nitric oxide synthase (eNOS) function. Exposure of bovine aortic endothelial cells with HOG-LDL reduced eNOS protein levels in a concentration- and time-dependent manner, without altering eNOS mRNA levels. Reduced eNOS protein levels were accompanied by an increase in intracellular Ca²⁺, augmented production of reactive oxygen species (ROS) and induction of Ca²⁺-dependent calpain activity. Neither eNOS reduction nor any of these other effects were observed in cells exposed to native LDL. Reduction of intracellular Ca²⁺ levels abolished eNOS reduction by HOG-LDL, as did pharmacological or genetic through calcium channel blockers or calcium chelator BAPTA or inhibition of NAD(P)H oxidase (with apocynin) or inhibition of calpain (calpain 1-specific siRNA). Consistent with these results, HOG-LDL impaired acetylcholine-induced endothelium-dependent vasorelaxation of isolated mouse aortas, and pharmacological inhibition of calpain prevented this effect. HOG-LDL may impair endothelial function by inducing calpain-mediated eNOS degradation in a ROS- and Ca²⁺-dependent manner.

Parents' and service providers' perceptions of family-centred practice in a community-based, paediatric disability service in Australia

BACKGROUND

For children who have physical disabilities and their families, involvement with a variety of providers of rehabilitation services is the norm rather than the exception. Despite family-centred practice (FCP) being recognized as the 'best practice' model, families experience models of service provision that range from 'expert' to 'collaborative'. After adopting FCP at Novita Children's Services in South Australia, it was imperative to determine the effectiveness of the implementation of FCP. Aim To investigate parents' and staff's perceptions of FCP at Novita as part of ongoing quality assurance activity, and to identify any gaps in the services provided.

METHODS

The Measures of Processes of Care (MPOC) for parents/caregivers and service providers were utilized. A total of 189 families stratified by the three age groups of clients (<6, 6-12 and 13-18 years) and home location (metropolitan and rural) completed the MPOC-20 questionnaire. A total of 145 staff, allied health therapists, rehabilitation engineers, managers and other staff who have direct contact with clients and their families completed the MPOC - service providers (MPOC-SP) questionnaire.

RESULTS

Parents generally rated the family-centred behaviours of staff as positive. Respectful and supportive care received the highest rating, while providing general information received the lowest. There were significant differences in scores for all five scales of the MPOC between metropolitan and rural families and the age of the child. Service providers also generally rated their family-centred behaviours as positive. There were significant differences among the professions in areas of showing interpersonal sensitivity and providing general information.

CONCLUSIONS

The findings suggest that parents and service providers perceive FCP as positive at Novita, with some areas for improvement. The MPOC-20 and MPOC-SP can be used to measure FCP and to identify service delivery gaps, which warrant further exploration.

Immune complexes containing modified lipoproteins are related to the progression of internal carotid intima-media thickness in patients with type 1 diabetes

Modified lipoproteins induce autoimmune responses including the synthesis of autoantibodies with pro-inflammatory characteristics. Circulating modified lipoprotein autoantibodies combine with circulating antigens and form immune complexes (IC). We now report the results of a study investigating the role of circulating IC containing modified lipoproteins in the progression of carotid intima-media thickness (IMT) in patients enrolled in the Epidemiology of Diabetes Interventions and Complications (EDIC) Trial, a follow-up study of the Diabetes Control and Complications Trial (DCCT). This cohort includes 1229 patients with type 1 diabetes in whom B-mode ultrasonography of internal and common carotid arteries was performed in 1994-1996 and in 1998-2000. Conventional CHD risk factors, antibodies against modified forms of LDL and modified lipoprotein IC were determined in 1050 of these patients from blood collected in 1996-1998. Cholesterol and apolipoprotein B content of IC (surrogate markers of modified ApoB-rich lipoproteins) were significantly higher in patients who showed progression of the internal carotid IMT than in those showing no progression, regression or mild progression. Multivariate linear and logistic regression modeling using conventional and non-conventional risk factors showed that the cholesterol content of IC was a significant positive predictor of internal carotid IMT progression. In conclusion these data demonstrate that increased levels of modified ApoB-rich IC are associated with increased progression of internal carotid IMT in the DCCT/EDIC cohort of type 1 diabetes.

Poliovirus 5'-terminal cloverleaf RNA is required in cis for VPg uridylylation and the initiation of negative-strand RNA synthesis

Chimeric poliovirus RNAs, possessing the 5' nontranslated region (NTR) of hepatitis C virus in place of the 5' NTR of poliovirus, were used to examine the role of the poliovirus 5' NTR in viral replication. The chimeric viral RNAs were incubated in cell-free reaction mixtures capable of supporting the sequential translation and replication of poliovirus RNA. Using preinitiation RNA replication complexes formed in these reactions, we demonstrated that the 3' NTR of poliovirus RNA was insufficient, by itself, to recruit the viral replication proteins required for negative-strand RNA synthesis. The 5'-terminal cloverleaf of poliovirus RNA was required in cis to form functional preinitiation RNA replication complexes capable of uridylylating VPg and initiating the synthesis of negative-strand RNA. These results are consistent with a model in which the 5'-terminal cloverleaf and 3' NTRs of poliovirus RNA interact via temporally dynamic ribonucleoprotein complexes to coordinately mediate and regulate the sequential translation and replication of poliovirus RNA.

Volumetric quantification of brain swelling after hypobaric hypoxia exposure

We applied a novel MR imaging technique to investigate the effect of acute mountain sickness on cerebral tissue water. Nine volunteers were exposed to hypobaric hypoxia corresponding to 4572 m altitude for 32 h. Such an exposure may cause acute mountain sickness. We imaged the brains of the volunteers before and at 32 h of hypobaric exposure with two different MRI techniques with subsequent data processing. (1) Brain volumes were calculated from 3D MRI data sets by applying a computerized brain segmentation algorithm. For this specific purpose a novel adaptive 3D segmentation program was used with an automatic correction algorithm for RF field inhomogeneity. (2) T(2) decay rates were analyzed in the white matter. The results demonstrated that a significant brain swelling of 36.2 +/- 19.6 ml (2.77 +/- 1.47%, n = 9, P < 0.001) developed after the 32-h hypobaric hypoxia exposure with a maximal observed volume increase of 5.8% (71.3 ml). These volume changes were significant only for the gray matter structures in contrast to the unremarkable changes seen in the white matter. The same study repeated 3 weeks later in 6 of 9 original subjects demonstrated that the brains recovered and returned approximately to the initially determined sea-level brain volume while hypobaric hypoxia exposure once again led to a significant new brain swelling (24.1 +/- 12.1 ml, 1.92 +/- 0.96%, n = 6, P < 0.005). On the contrary, the T(2) mapping technique did not reveal any significant effect of hypobaria on white matter. We present here a technique which is able to detect reversible brain volume changes as they may occur in patients with diffuse brain edema or increased cerebral blood volume, and which may represent a useful noninvasive tool for future evaluations of antiedematous drugs.

Proximal tibia--extensor mechanism composite allograft for revision TKA with chronic patellar tendon rupture

Rupture of the patellar tendon following TKA is fortunately an uncommon complication with an incidence of 0.2-4% (Abril et al. 1995). Numerous options have been reported for treating this complication, including primary suture into a bone trough (Abril et al. 1995), autogenous tendon transfer (Cadambi and Engh 1992), and use of an artificial ligament (Fujikawa et al. 1994). Allograft patellar tendon has also been utilized either retaining the host patella and using a bone-tendon-bone graft or excising the host patella and using a quadriceps tendon-patella-patellar tendon-tibial tubercle graft (Emerson et al. 1990, Emerson et al. 1994, Zanotti et al. 1995, Booth et al. 1999). All of these techniques require structural integrity of the proximal tibia in the area of the tibial tubercle in order to attach the repair or graft to restore continuity of the extensor mechanism. When there is massive osteolysis and bone loss involving the proximal tibia, the situation becomes more complex and the previously described techniques are not advisable. In such cases, function can be obtained with a composite allograft of proximal tibia-patellar tendon-patella-quadriceps tendon. We describe a technique for dealing with this difficult clinical situation.

Interaction of chemical defense clothing and high terrestrial altitudes on lift/carry and marksmanship performance

BACKGROUND

The increased metabolic energy requirement imposed by a chemical defense uniform (CDU) and the lower maximal aerobic capacity associated with increased altitude should produce greater demands on the cardiopulmonary system during the performance of a given work task at increasing altitudes. We hypothesized that: a) relative to sea level, the decrements in physical work performance caused by ascending to high terrestrial altitudes would be greater in a CDU compared with a standard fatigue uniform (U.S. Army, BDU); b) the aversive subjective reactions to the CDU would be accentuated with increasing altitude; and c) that staging at moderate altitude, to induce acclimatization, would restore work performance at higher altitudes to sea level norms.

METHODS

The physiological and subjective responses of 8 male soldiers to work (10-min lift-and-carry task and rifle marksmanship) were measured. Subjects wore the BDU and a CDU ensemble (U.S. Army, BDO) at sea level, intermediate (2743 m) and high (4,300 m) altitudes following rapid and staged (3 d at 1,830 m) ascents to the higher altitudes.

RESULTS

Lift/carry task performance tended to be lower (p = 0.076) in the CDU vs. the BDU at altitude. The cardiopulmonary responses to the lift/carry task increased at altitude and were greater in the CDU. The subjects' perception of their ability to perform the lift/carry task at altitude was adversely impacted more in the CDU than the BDU. Rapid ascent to intermediate altitude degraded marksmanship in both uniforms. Following staged ascent, lift/carry task and marksmanship performance was restored to sea level norms.

CONCLUSIONS

Personnel wearing CDU or equivalent protective clothing at intermediate to high terrestrial elevations should anticipate proportionally larger CDU-induced decrements of work performance and lower tolerance to working in a CDU than experienced near sea level. Staging at moderate altitude is an effective strategy for restoring work performance to sea level norms at higher altitudes.

Does ascorbate in the mesophyll cell walls form the first line of defence against ozone? Testing the concept using broad bean (Vicia faba L.)

Broad bean (Vicia faba L.) plants were exposed, in duplicate controlled environment chambers, to charcoal/Purafil-filtered air (CFA-grown plants) or to 75 nmol mol(-1) ozone (O(3)) for 7 h d(-1) (O(3)-grown plants) for 28 d, and then exposed to 150 nmol mol(-1) O(3 )for 8 h. The concentration of ascorbate (ASC) was determined in leaf extracellular washing fluid (apoplast) and in the residual leaf tissue (symplast) after 0, 4 and 8 h acute fumigation, and after a 16 h "recovery" period in CFA. Changes in stomatal conductance were measured in vivo in order to model pollutant uptake, while the light-saturated rate of CO(2) assimilation (A:(sat)) was recorded as an indicator of O(3)-induced intracellular damage. Measurements of A:(sat) revealed enhanced tolerance to 150 nmol mol(-1) O(3) in plants pre-exposed to the pollutant compared with equivalent plants grown in CFA, consistent with the observed reduction in pollutant uptake due to lower stomatal conductance. The concentration of ASC in the leaf apoplast (ASC(apo)) declined upon O(3)-treatment in both CFA- and O(3)-grown plants, consistent with the oxidation of ASC(apo) under O(3)-stress. Furthermore, the decline in ASC(apo) was reversible in O(3)-grown plants after a 16 h "recovery" period, but not in plants grown in CFA. No significant change in the level and/or redox state of ASC in the symplast (ASC(symp)) was observed in plants exposed to 150 nmol mol(-1) O(3), and there was no difference in the constitutive level of ASC(symp) between CFA- and O(3)-grown plants. Model calculations indicated that the reaction of O(3) with ASC(apo) in the leaves of Vicia faba is potentially sufficient to intercept a substantial proportion (30-40%) of the O(3)entering the plant under environmentally-relevant conditions. The potential role of apoplastic ASC in mediating the tolerance of leaves to O(3) is discussed.

Simulating ozone detoxification in the leaf apoplast through the direct reaction with ascorbate

This paper presents a mathematical model which enables the semi-quantification of ozone (O3) detoxification, based upon the direct reaction of the pollutant with ascorbate (ASC) located in the aqueous matrix associated with the cell wall (i.e. the apoplast). The model describes the uptake of ozone into the leaf and its direct reaction with ASC, taking into consideration the regeneration of dehydroascorbic acid in the cytosol, the rate of replenishment of cell wall ASC and the distribution of ASC between sub-cellular compartments based upon the permeability of biomembranes to the neutral species, ascorbic acid and the pH of various sub-cellular compartments. The importance of various physico-chemical characteristics (e.g. stomatal conductance, mesophyll cell wall thickness and tortuosity, chloroplast volume, apoplast pH, ASC:O3 reaction stoichiometry) in mediating the flux of ozone to the plasmalemma is analysed. Model simulations, supported by experimental observations, suggest that the ASC concentration in the leaf apoplast is high enough to scavenge a significant proportion of the O3 taken up into the leaf interior, under environmentally relevant conditions. However, there is considerable variation between taxa in the potential degree of protection afforded by apoplastic ASC, emphasizing the need for an improved understanding of the reaction chemistry of O3 in the cell wall.

The copper transport protein Atox1 promotes neuronal survival

Atox1, a copper transport protein, was recently identified as a copper-dependent suppressor of oxidative damage in yeast lacking superoxide dismutase. We have previously reported that Atox1 in the rat brain is primarily expressed in neurons, with the highest levels in distinct neuronal subtypes that are characterized by their high levels of metal, like copper, iron, and zinc. In this report, we have transfected the Atox1 gene into several neuronal cell lines to increase the endogenous level of Atox1 expression and have demonstrated that, under conditions of serum starvation and oxidative injury, the transfected neurons are significantly protected against this stress. This level of protection is comparable with the level of protection seen with copper/zinc superoxide dismutase and the anti-apoptotic gene bcl-2 that had been similarly transfected. Furthermore, neuronal cell lines transfected with a mutant Atox1 gene, where the copper binding domain has been modified to prevent metal binding, do not afford protection against serum starvation resulting in apoptosis. Therefore, Atox1 is a component of the cellular pathways used for protection against oxidative stress.

Impacts of ozone on the growth and yield of field-grown winter wheat

Seed of winter wheat (Triticum aestivum L. cv Riband) was sown on 29 August 1992 in eight field plots. Four plots were exposed to elevated ozone (O(3)) concentrations on 16 days between 29 August and 2 October 1992, for 6 h day(-1), and on 27 days between 29 March and 24 August 1993, for 7 h day(-1). Mean daily O(3) concentrations were approximately 30 and 80 nmol mol(-1) in ambient and fumigated plots, respectively. Plants were sampled on 5 November (1992), 14 January, 16 February, 1 April, 25 May, 23 June and 24 August (1993). No visible symptoms of O(3) damage or premature senescence were observed at any time over the course of the experiment. Exposure to elevated O(3) decreased the above ground biomass by reducing plant density and individual plant relative growth rate. However, there was no significant influence of the pollutant on the growth of the root relative to the shoot. Assessment of yield characteristics at the final harvest revealed an O(3)-induced decrease in the number of grains per ear, as a result of fewer grains per spikelet and an increase in the number of infertile florets per spikelet. No significant effects of the pollutant on the number of ears per plant, spikelets per ear, or 1000 grain weight were found. As a result of the combined effects on the number of grains per ear and the decrease in plant density and growth rate, O(3) exposure reduced grain and straw yields (tonnes ha(-1)) by 13 and 8%, respectively. However, no significant change in the partitioning of dry matter between the grain and the straw was observed in fumigated plots. The findings are discussed within the context of United Nation Economic Commission for Europe critical level guidelines for the protection of crop yields, in relation to their application to winter-sown crops.

Association of anti-Yo (type I) antibody with paraneoplastic cerebellar degeneration in the setting of transitional cell carcinoma of the bladder: detection of Yo antigen in tumor tissue and fall in antibody titers following tumor removal

Anti-Yo (type I) autoantibodies reactive with Purkinje cell cytoplasmic antigens of 34 and 62 kd are found in the serum and cerebrospinal fluid of patients with paraneoplastic cerebellar degeneration associated with cancer of the ovary, uterus, adnexa, or breast. Anti-Yo antibody response is rarely associated with other tumors. Here, we present a patient who developed paraneoplastic cerebellar degeneration and anti-Yo antibody response in association with transitional cell carcinoma of the bladder. The presence of anti-Yo antibodies was confirmed by immunofluorescence assay and by Western blot analysis against both Purkinje cell lysates and the CDR62 fusion protein. Yo antigen was demonstrated in sections of the patient's tumor. Antibody titers fell after tumor removal. Transitional cell carcinoma should be considered in patients presenting with subacute cerebellar degeneration and anti-Yo antibody response in whom ovarian, adnexal, uterine, or breast cancer cannot be detected.

Diabetes research in South Carolina: past, present, and future

Medical investigators in South Carolina have been on the "cutting edge" of diabetes research for a number of decades. Despite this fact, our state ranks second in the nation in diabetes prevalence, and diabetes complications are more severe here than anywhere else. It is from the efforts of these investigators that our hope for a brighter future comes. Through a concerted effort toward prevention, improvements in care, and investigation of the pathophysiology of diabetes and its complications, researchers may reduce the substantial burden of diabetes in our state and throughout the world.

Transmission of two novel mutations in a pedigree with familial lecithin:cholesterol acyltransferase deficiency: structure-function relationships and studies in a compound heterozygous proband

Two novel mutations were identified in a compound heterozygous male with lecithin:cholesterol acyltransferase (LCAT) deficiency. Exon sequence determination of the LCAT gene of the proband revealed two novel heterozygous mutations in exons one (C110T) and six (C991T) that predict non-conservative amino acid substitutions (Thr13Met and Pro307Ser, respectively). To assess the distinct functional impact of the separate mutant alleles, studies were conducted in the proband's 3-generation pedigree. The compound heterozygous proband had negligible HDL and severely reduced apolipoprotein A-I, LCAT mass, LCAT activity, and cholesterol esterification rate (CER). The proband's mother and two sisters were heterozygous for the Pro307Ser mutation and had low HDL, markedly reduced LCAT activity and CER, and the propensity for significant reductions in LCAT protein mass. The proband's father and two daughters were heterozygous for the Thr13Met mutation and also displayed low HDL, reduced LCAT activity and CER, and more modest decrements in LCAT mass. Mean LCAT specific activity was severely impaired in the compound heterozygous proband and was reduced by 50% in individuals heterozygous for either mutation, compared to wild type family members. It is also shown that the two mutations impair both catalytic activity and expression of the circulating protein.

Safety and efficacy of early extubation of elderly coronary artery bypass surgery patients

OBJECTIVE

Early extubation and fast-track management protocols on younger, low-risk patients result in shorter hospital stays and decreased costs. The impact of such protocols on elderly patients undergoing coronary artery bypass graft (CABG) surgery is not presently known.

DESIGN

A matched retrospective cohort study.

SETTING

A university teaching hospital.

PARTICIPANTS

Six hundred ninety-eight consecutive patients undergoing isolated CABG between January 1995 and September 1996.

INTERVENTIONS

Three hundred seventy-seven patients underwent early extubation, defined as extubation within 8 hours of arrival in the intensive care unit. They were divided into groups of patients 70 years of age and younger (n = 263) and patients older than 70 years of age (n = 114).

RESULTS

The mean length of stay (LOS) for all patients extubated within 8 hours or less was 5.5 days versus 8.4 days for patients who underwent later extubation (p < 0.0001). The percentage of patients undergoing early extubation was greater for the younger cohort (59% v 48%; p < 0.003) compared with the older cohort of patients. Analysis of demographics showed the older patients to have a greater incidence of peripheral vascular disease, congestive heart failure, and prior strokes (p < 0.05). Although the intensive care unit LOS was similar, postoperative LOS was 5.3 +/- 1.8 days for the younger patients versus 6.1 +/- 2.6 days for the older patients (p = 0.001). The overall surgical mortality rate was 2.6% (18/698), and there were no deaths among patients undergoing early extubation. Reintubation rate was negligible in both groups of patients.

CONCLUSION

This study confirms the safety and efficacy of early extubation among elderly patients undergoing CABG. Elderly patients have more comorbid conditions, yet a significant number can be extubated early, with resultant shortened LOSs.

Diabetes management: current diagnostic criteria, drug therapies, and state legislation

The policies, standards, guidelines, and criteria that each member of the healthcare team uses to assist in the delivery of comprehensive healthcare are constantly being defined and redefined. This article has discussed many of those changes as they relate to diabetes management. The entire healthcare team must have a working knowledge of these changes so that they can continue to deliver the best possible care to patients with diabetes. Improvements in quality of life, decreases in mortality and morbidity, and subsequent declines in healthcare costs will benefit both individual patients and society. The profession of pharmacy has realized the need for additional education and training in managing the patient with diabetes. Many colleges of pharmacy, as well as companies in the pharmaceutical industry, are offering diabetes certification and diabetes disease management programs to pharmacists to enhance their ability to manage these patients (Lyons T, Gourley DR, unpublished data, 1997. Similar efforts in diabetes management have been made in other health professions as well, such as nursing.

Effects of erythrocyte infusion on VO2max at high altitude

This study investigated whether autologous erythrocyte infusion would ameliorate the decrement in maximal O2 uptake (VO2max) experienced by lowlanders when they ascend to high altitude. VO2max was measured in 16 men (treadmill running) at sea level (SL) and on the 1st (HA1) and 9th (HA9) days of high-altitude (4,300 m) residence. After VO2max was measured at SL, subjects were divided into two matched groups (n = 8). Twenty-four hours before ascent to high altitude, the experimental group received a 700-ml infusion of autologous erythrocytes and saline (42% hematocrit), whereas the control group received only saline. The VO2max of erythrocyte-infused [54 +/- 1 (SE) ml.kg-1.min-1] and control subjects (52 +/- 2 ml.kg-1.min-1) did not differ at SL before infusion. The decrement in VO2max on HA1 did not differ between groups, averaging 26% overall, despite higher (P < 0.01) arterial hematocrit, hemoglobin concentration, and arterial O2 content in the erythrocyte-infused subjects. By HA9, there were no longer any differences in hematocrit, hemoglobin concentration, or arterial O2 content between groups. No change in VO2max occurred between HA1 and HA9 for either group. Thus, despite increasing arterial O2-carrying capacity, autologous erythrocyte infusion did not ameliorate the decrement in VO2max at 4,300-m altitude.