Does anesthesia duration or number of cases per patient predict safety events?

BACKGROUND: The need for dental rehabilitation under general anesthesia is increasing, with varying needs between patients. Mortality has been found to be a rare event in these patients; however other perioperative events can and do occur. Previous studies have established increased incidence of perioperative events with younger, sicker children, and longer anesthetics, however, no studies to date have evaluated if the incidence of perioperative events is more closely associated with one long anesthetic or multiple anesthetics per patient. AIMS: To evaluate the association of perioperative events related to single anesthetic duration or number of anesthetics per patient for dental rehabilitation. METHODS: After Children's Wisconsin Human Research Protection Program determined this quality activity did not meet the definition of human subjects research, we performed an epidemiologic observational evaluation by extracting all dental related cases (dental alone or with oral surgeon vs. dental with other specialties) with an associated general anesthesia encounter from Children's Wisconsin electronic data warehouse from June 1, 2015 to December 31, 2021. These cases occurred at a free-standing children's hospital or associated pediatric-only ambulatory surgery center. The risk of perioperative safety events was analyzed for previously identified risk groups such as American Society of Anesthesiologists Physical Status (ASA-PS), patient age, anesthesia case time with the addition of number of dental cases per patient. RESULTS: In this study, 8468 procedures were performed on 8082 patients. Of this cohort, 7765 patients underwent one procedure for dental care while 317 patients underwent a total of 703 dental-related procedures, ranging from two to five procedures per patient. Multivariable logistic regression identified increased risk of perioperative events in patients with ASA-PS 3 (n = 1459, rate 1.78%, p value .001, OR 5.7, CI 2.1-15.5) and ASA-PS 4 (n = 86, rate 5.8%, p < .001, OR 17.2, CI 4.4-67.3), anesthesia duration (p < .001, OR 1.46, CI 1.21-1.76), but no increased risk with number of anesthetics per patient (p value .54, OR 0.81, CI 0.4-1.61). CONCLUSIONS: Limiting dental care under general anesthesia to multiple short cases may decrease the risk of perioperative events when compared to completing all treatment in one long operative session.

Crop production in the USA is frequently limited by a lack of pollinators.

Most of the world's crops depend on pollinators, so declines in both managed and wild bees raise concerns about food security. However, the degree to which insect pollination is actually limiting current crop production is poorly understood, as is the role of wild species (as opposed to managed honeybees) in pollinating crops, particularly in intensive production areas. We established a nationwide study to assess the extent of pollinator limitation in seven crops at 131 locations situated across major crop-producing areas of the USA. We found that five out of seven crops showed evidence of pollinator limitation. Wild bees and honeybees provided comparable amounts of pollination for most crops, even in agriculturally intensive regions. We estimated the nationwide annual production value of wild pollinators to the seven crops we studied at over $1.5 billion; the value of wild bee pollination of all pollinator-dependent crops would be much greater. Our findings show that pollinator declines could translate directly into decreased yields or production for most of the crops studied, and that wild species contribute substantially to pollination of most study crops in major crop-producing regions.

ORE identifies extreme expression effects enriched for rare variants.

MOTIVATION: Non-coding rare variants (RVs) may contribute to Mendelian disorders but have been challenging to study due to small sample sizes, genetic heterogeneity and uncertainty about relevant non-coding features. Previous studies identified RVs associated with expression outliers, but varying outlier definitions were employed and no comprehensive open-source software was developed. RESULTS: We developed Outlier-RV Enrichment (ORE) to identify biologically-meaningful non-coding RVs. We implemented ORE combining whole-genome sequencing and cardiac RNAseq from congenital heart defect patients from the Pediatric Cardiac Genomics Consortium and deceased adults from Genotype-Tissue Expression. Use of rank-based outliers maximized sensitivity while a most extreme outlier approach maximized specificity. Rarer variants had stronger associations, suggesting they are under negative selective pressure and providing a basis for investigating their contribution to Mendelian disorders. AVAILABILITY AND IMPLEMENTATION: ORE, source code, and documentation are available at https://pypi.python.org/pypi/ore under the MIT license. SUPPLEMENTARY INFORMATION: Supplementary data are available at Bioinformatics online.

Immunoglobulin (Ig)M antibodies to proteinase 3 in granulomatosis with polyangiitis and microscopic polyangiitis.

Anti-neutrophil cytoplasmic antibodies (ANCA) appear to play an important role in the pathogenesis of ANCA-associated vasculitis (AAV). However, ANCA alone are not sufficient to generate disease, and some evidence suggests that infectious triggers may serve as inciting events for AAV disease activity. Antibodies of the immunoglobulin (Ig)M isotype often serve as markers of recent infection, and IgM ANCA have been identified previously in patients with AAV, although the frequency and clinical relevance of IgM ANCA is not well established. We sought to characterize IgM ANCA more clearly by creating a novel enzyme-linked immunosorbent assay (ELISA) for IgM antibodies to proteinase 3 [IgM proteinase 3 (PR3)-ANCA], which we applied to two large, clinically well-characterized trial cohorts of patients with granulomatosis with polyangiitis and microscopic polyangiitis. In the first cohort, IgM PR3-ANCA occurred with a frequency of 15·0%, and were associated with a higher degree of disease severity and a trend towards a higher rate of alveolar haemorrhage (29·6 versus 15·7%, P = 0·10). Analysis of follow-up samples in this cohort showed that the presence of IgM PR3-ANCA was transient, but could recur. In the second cohort, IgM PR3-ANCA occurred with a frequency of 41·1%, and were also associated with a higher degree of disease severity. A higher rate of alveolar haemorrhage was observed among those with IgM PR3-ANCA (45·3 versus 15·8%; P < 0·001). The association of transient IgM PR3-ANCA with an acute respiratory manifestation of AAV suggests a possible link between an infectious trigger and AAV disease activity.

Establishing the Feasibility of Face Transplantation in Granulomatosis With Polyangiitis.

Granulomatosis with polyangiitis (GPA; formerly Wegener's granulomatosis) is a rare vasculitis that commonly starts in the craniofacial region. We report a case that was masked by prior facial trauma and associated with pyoderma gangrenosum (PG). Disease progression and aggressive debridements led to severe facial tissue loss. The decision to perform a face transplant was controversial because of the risk of disease relapse on the facial allograft. We reviewed renal transplant outcomes in GPA for possible relevance. A PubMed search retrieved 29 studies. Patient and graft survival, relapse, morbidity, mortality, rejection and immunosuppression were assessed. Ten-year patient survival and graft survival were 84.4% and 72.6%, respectively. GPA relapse occurred in 31.5%, and upper airway/ocular relapse occurred in 17.8% (resolved in 76.9%). Mortality was 12.3%. Acute and chronic rejection rates were 14.9% and 6.8%, respectively. Traditional posttransplant immunosuppression was effective. Our review suggests that GPA renal transplant outcomes are comparable to general renal transplant cohorts. Furthermore, transplanted GPA patients exhibit lower disease relapse secondary to lifelong immunosuppression. This supported our decision to perform a face transplant in this patient, which has been successful up to the present time (1-year posttransplantation). Untreated GPA and PG are potential causes of worse surgical outcomes in the craniofacial region.

Comparability of patients with ANCA-associated vasculitis enrolled in clinical trials or in observational cohorts.

OBJECTIVES: To analyse the differences between patients with granulomatosis with polyangiitis (GPA) or microscopic polyangiitis (MPA) entered into randomised clinical trials (RCTs) and those followed in large observational cohorts. METHODS: The main characteristics and outcomes of patients with generalised and/or severe GPA or MPA with a five-factor score ≥ 1 enrolled in the French Vasculitis Study Group (FVSG) or the US-Canadian-based Vasculitis Clinical Research Consortium cohorts were compared to those enrolled in one of 2 FVSG clinical RCTs (WEG91, WEGENT) or 3 European Vasculitis Society clinical trials (CYCLOPS, CYCAZAREM, IMPROVE). RESULTS: 657 patients (65.3% with GPA) in RCTs were compared to 437 in cohorts (90.6% with GPA). RCT patients were older at diagnosis than the cohort patients (56.6 ± 13.9 vs. 46.8 ± 17.3 years), had higher Birmingham vasculitis activity score (19.5 ± 9.1 vs. 16.9 ± 7.4), and more frequent kidney disease (84.0% vs. 54.9%) but fewer ear, nose, and throat symptoms (56.8% vs. 72.2%). At 56 months post-diagnosis, mortality and relapse rates, adjusted for age and renal function, were higher for patients with GPA in RCTs vs. cohorts (10.7% vs. 2.5% [p=0.001] and 22.5% vs. 15.6% [p=0.03], respectively) but similar for patients with MPA (6.2% vs. 6.6% [p=0.92] and 16.6% vs. 10.1% [p=0.39], respectively). CONCLUSIONS: Patients with GPA or MPA in RCTs and those in observational cohorts show important differences that should be remembered when interpreting results based on these study populations.

Clinical outcomes of remission induction therapy for severe antineutrophil cytoplasmic antibody-associated vasculitis.

OBJECTIVE: To evaluate the reasons that complete remission is not achieved or maintained with original treatment in some patients with antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV) treated with rituximab (RTX) or with cyclophosphamide/azathioprine (CYC/AZA). METHODS: The Rituximab in AAV trial was a randomized, double-blind, placebo-controlled trial comparing the rate of remission induction among patients treated with RTX (n = 99) and patients treated with CYC followed by AZA (n = 98). Glucocorticoids were tapered over a period of 5 months. The primary outcome measure was lack of disease activity without glucocorticoid treatment at 6 months. To determine the most important reason for failure to achieve the primary outcome, 7 hierarchical categories of reasons were defined retrospectively (uncontrolled disease, adverse event leading to therapy discontinuation, severe flare, limited flare, Birmingham Vasculitis Activity Score for Wegener's Granulomatosis >0, prednisone treatment at any dosage, and other). RESULTS: Although remission (lack of disease activity) was achieved in 170 of the 197 patients (86%) in the first 6 months, the primary outcome measure was not achieved in 42%. There were 3 deaths. Twenty-four percent of the patients failed to achieve the primary end point due to active disease: 10 (5%) experienced uncontrolled disease in the first month and 37 (19%) experienced flares after initial improvement. In the majority of such patients, treatment with blinded crossover or according to best medical judgment led to disease control. Ninety-one percent of patients who had uncontrolled disease or experienced a severe flare had proteinase 3 (PR3)-ANCA. When patients with uncontrolled disease were excluded from analysis, those who were PR3-ANCA positive were found to experience fewer flares when treated with RTX compared to CYC/AZA (8 of 59 [14%] versus 20 of 62 [32%]; P = 0.02). Neither ANCA titers nor B cell counts predicted disease flare. CONCLUSION: Current treatment regimens are largely successful in controlling AAV, but in approximately one-fourth of patients, active disease persists or recurs in the first 6 months despite treatment. PR3-ANCA positivity is a risk factor for recurrence or persistence of severe disease. ANCA titers and B cell detectability are poor predictors of both disease relapse and disease quiescence in the first 6 months.

Lymphoedema following treatment for head and neck cancer: impact on patients, and beliefs of health professionals.

Cervicofacial lymphoedema is a recognised side-effect that may result following treatment for head and neck cancer. This study aimed to investigate the perspectives of affected patients and the beliefs that treating health professionals hold about head and neck lymphoedema. Ten patients with head and neck lymphoedema and 10 health professionals experienced in the treatment of head and neck cancer patients agreed to participate in semi-structured face to face interviews. Interviews were recorded, audio files were transcribed and coded and then analysed for themes. Themes of experiences of patients with head and neck lymphoedema and the beliefs of health professionals largely overlapped. Given its visible deformity, the main effect of lymphoedema in head and neck cancer patients was on appearance. In some cases this lead to negative psychosocial sequelae such as reduced self-esteem, and poor socialisation. Clinicians need to be aware of those patients more likely to experience lymphoedema following treatment for head and neck cancer, and how they are affected. Understanding how patients with facial lymphoedema are affected psychologically and physically, and the importance of prompt referral for lymphoedema treatment, might ultimately improve outcomes and ensure optimal management.

Health assessment of gasoline and fuel oxygenate vapors: developmental toxicity in mice.

CD-1 mice were exposed to baseline gasoline vapor condensate (BGVC) alone or to vapors of gasoline blended with methyl tertiary butyl ether (G/MTBE). Inhalation exposures were 6h/d on GD 5-17 at levels of 0, 2000, 10,000, and 20,000mg/m(3). Dams were evaluated for evidence of maternal toxicity, and fetuses were weighed, sexed, and evaluated for external, visceral, and skeletal anomalies. Exposure to 20,000mg/m(3) of BGVC produced slight reductions in maternal body weight/gain and decreased fetal body weight. G/MTBE exposure did not produce statistically significant maternal or developmental effects; however, two uncommon ventral wall closure defects occurred: gastroschisis (1 fetus at 10,000mg/m(3)) and ectopia cordis (1 fetus at 2000mg/m(3); 2 fetuses/1 litter at 10,000mg/m(3)). A second study (G/MTBE-2) evaluated similar exposure levels on GD 5-16 and an additional group exposed to 30,000mg/m(3) from GD 5-10. An increased incidence of cleft palate was observed at 30,000mg/m(3) G/MTBE. No ectopia cordis occurred in the replicate study, but a single observation of gastroschisis was observed at 30,000mg/m(3). The no observed adverse effect levels for maternal/developmental toxicity in the BGVC study were 10,000/2000mg/m(3), 20,000/20,000 for the G/MTBE study, and 10,000/20,000 for the G/MTBE-2 study.

Kidney transplant utilising donors after circulatory death: The first report from the African continent.

BACKGROUND: At Groote Schuur Hospital in Cape Town, South Africa, the number of deceased organ donors has declined over the past 2 decades, necessitating a more liberal approach to donor selection. In 2007, measures to expand the deceased kidney donor pool were implemented, including an HIV positive-to-positive transplant programme and the utilisation of extended-criteria donors as well as donors after circulatory death (DCDs). OBJECTIVES: To report on our institutional experience with DCD kidney transplants and to encourage this approach among other African centres to improve access to transplantation. METHODS: An observational cohort study of consecutive DCD kidney transplants at Groote Schuur Hospital over a 17-year period was performed. Primary endpoints were 1-, 2- and 5-year graft and patient survival. Secondary endpoints included the incidence of delayed graft function (DGF), 30-day morbidity, length of stay, and donor and recipient clinical characteristics. RESULTS: Fifteen DCD procurements were performed, with no kidneys discarded. Thirty kidney transplants were performed, with a median (interquartile range) cold ischaemic time of 11.5 (8 - 14) hours. The incidence of DGF was 60.0%, and 30-day morbidity (other than DGF) was 20.0%. Graft survival at 1, 2 and 5 years was 100%, 96.0% and 73.7%, respectively. Patient survival at 1, 2 and 5 years was 93.3%, 93.3% and 88.4%, respectively. CONCLUSION: Long-term graft and patient survival was comparable with the international literature. DCD may present a unique opportunity to expand deceased donation throughout Africa, particularly in areas affected by a lack of brain death legislation and religious or cultural objections to donation after brain death.

A missense mutation in type VII collagen in two affected siblings with recessive dystrophic epidermolysis bullosa.

Recessive dystrophic epidermolysis bullosa is a severe mutilating genodermatosis. Previous ultrastructural demonstrations of altered anchoring fibrils, and recent genetic linkage analyses have suggested that type VII collagen, the major component of anchoring fibrils, is a candidate gene. We have identified a homozygous methionine-to-lysine mutation in two affected siblings, while their unaffected mother and half-brother are heterozygous carriers. The mutation resides in a highly conserved region of the C-terminus of type VII collagen, strongly suggesting that it is the cause of the disease in this family.

Geographic remoteness from a multidisciplinary team is associated with an increased clinical staging of head and neck cancer: a Newcastle (Australia) study.

The purpose of this study was to investigate the relationship between a patient's residential distance from a tertiary referral regional multidisciplinary team (MDT) and the clinical staging of their head and neck cancer (HNC) at presentation. A retrospective cohort study was performed of all attendees with HNC who had undergone an MDT assessment. The period of study was January 2016 to January 2017. The primary predictor variable was the patient's residential distance from the MDT. Demographic and clinicopathological factors were recorded. The primary outcome variable was the clinical staging conferred by the MDT. Descriptive and ordinal logistical regression analyses were conducted to examine the data. There were 286 observations; 230 patients were male and 56 were female. The mean age of the cohort was 66.52 years. The average residential distance from the MDT was 68.16 km. Regression analysis, while not statistically significant, indicated that those living more than 100 km (range 102-592 km) from the MDT had a 1.49 times increased risk of being diagnosed with an advanced stage of cancer when compared to those living less than 100 km away. This study provides insights into the potential adverse effect geographic remoteness has on initial staging of HNC and the need for further strategies to serve this at-risk population.

What does the future hold for clinical studies in vasculitis?

The era prior to 1990 was a time of careful observation of disease presentation, course, outcomes and meticulous pathology studies. These mainly single-centre studies introduced new life-saving therapies for drugs still used effectively today. In the 1970-1980s, cyclophosphamide (CyP) added to glucocorticosteroids (GCS) was shown to be life-saving. The trade-off was often severe adverse events. Some forms of vasculitis were found not as ominous as thought initially. Some could be treated with safer drugs [e.g. methotrexate (MTX)]. However, whether mild or severe, patients were not cured. From 1990 to the present large collaborative networks have provided studies were not possible heretofore. Randomized controlled trials captured and manipulated vast amounts of data, banked biological specimens and shared these resources and intellectual capital, moving the field forward at an extraordinary pace. We now know that even for severe forms of granulomatosis and polyangiitis [granulomatosis with polyangiitis (GPA), Wegener's granulomatosus (WG)], microscopic polyangiitis (MPA) and Churg-Strauss syndrome (CSS), we do not need to use CyP for extended periods. We have learned recently that rituximab is as effective as CyP for severe WG and MPA. We should never again see the permanent toxicities born from years of chronic CyP use. However, short courses of CyP remain useful and can be life-saving. Step-down therapy from CyP is now a standard of care, perhaps to be replaced by rituximab in the future. If one accepts the premise that there are few cures at present for idiopathic large- and small-vessel vasculitis, we will serve our patients well if we can determine the most effective initial therapy that leads to a maintenance strategy for remission with least risk. Ultimately, we wish to identify causes of vasculitis so they can be used as a wedge to secure cures. Unmet needs and strategies are as follows: (1) to increase the numbers of vasculitis-trained physicians; (2) to define risk-benefit formulae for chronic maintenance therapy versus discontinuation of treatment after remission; (3) to define risk- and cost-benefit formulae for laboratory monitoring; (4) large-scale studies with longer follow-up that explore inhibition of interleukin-5 in CSS; (5) to explore the value of anti-interferon-γ for GCA, Takayasu's and other granulomatous vasculitides; and (6) identification of aetiological factors: cures will probably be linked to knowledge of the antigen driving the disease, plus vulnerabilities of the patient that prepare them to develop an illness phenotype. Improved outcomes using anti-inflammatory/immunosuppressive agents do not rule out infection as a driver for autoimmunity. Techniques that can facilitate pathogen discovery have never been more sophisticated.

COVID-19 social-distancing measures altered the epidemiology of facial injury: a United Kingdom-Australia comparative study.

The purpose of this study was to undertake a retrospective cross-sectional analysis to compare the frequency and characteristics of facial injury presentations at a UK and an Australian tertiary referral hospital during the implementation of COVID-19 social-distancing measures. The primary predictor variables were a heterogeneous set of factors grouped into logical categories: demographics, injury mechanisms and site, and management. The primary outcome variable was the presentation of a hard or soft tissue facial injury. A descriptive statistical analysis was undertaken on the assembled data. The study found a clinical and statistically significant reduction in the frequency (absolute number) of facial injuries at each study site. In addition, a striking similarity common in both countries was an increase in the number of facial injuries due to falls and a reduction in facial injuries due to interpersonal violence. Conservative (non-operative) management of facial injury increased at both sites. The implementation of COVID-19 social-distancing public health measures, which aimed to limit community transmission of the coronavirus, had a secondary serendipitous effect of reducing the frequency of facial injury presentations and altering their epidemiological characteristics at both a UK and Australian tertiary referral hospital.

Proliferation and differentiation of hematopoietic stem cells in long-term cultures of adult hamster spleen.

We have found that in liquid cultures of spleen cells of adult Syrian hamsters of the F1D strain, the hematopoietic microenvironment is adequate to sustain proliferation of splenic stem cells for periods of greater than 4 mo, and permits granulocytic, monocytic, and megakaryocytic differentiation without secondary repopulation or addition of exogenous growth factors to the basic medium of RPMI 1640 plus 20% horse serum. Intimate topographical relations are established between spleen stromal cells and hematopoietic cell components of the culture is adherent "cell-producing" islets. Some of these islets are associated with multiple hematopoietic cell types such as myeloid, monocytic, and megakaryocytic cells. Other islets are associated with a single cell type such as megakaryocytes, which suggests a limited potential of some adherent stromal cells to direct the differentiation of precursor cells. Cultures of this type provide a simple and convenient model for investigation of the mechanisms controlling differentiation of hematopoietic stem cells, not only for granulocytic and monocytic cells, but for megakaryocytic cells as well.

Endothelins, peptides with potent vasoactive properties, are produced by human macrophages.

Endothelins are peptides, originally isolated from endothelial cells, with potent vasoactive and mitogenic properties. In this study, we demonstrate that human macrophages synthesize and secrete endothelins. Cultured human macrophages were found by immunocytochemistry to stain positively for endothelin 1 and endothelin 3. Their capability to produce and release these peptides was confirmed by a combination of reverse-phase high-performance liquid chromatography and radioimmunoassays, specific for endothelin 1 and 3, respectively. Immunoreactive peptides were identified both in cellular extracts and in macrophage-conditioned medium. The secretion of endothelin 1, but not of endothelin 3, from macrophages could be stimulated 6-10-fold by lipopolysaccharide or phorbol myristate acetate (PMA). Northern blot analysis of total macrophage RNA using an endothelin 1 cDNA probe revealed induction of endothelin mRNA in PMA-treated macrophages. Furthermore, immunoreactive endothelin 1 and 3 were found in U937 cells, a human promonocytic line, and in freshly isolated human monocytes. In contrast, no immunoreactive endothelin was detected in cell extracts from human neutrophils and lymphocytes. The expression of endothelins in tissue macrophages was demonstrated in paraffin sections of human lung using immunohistochemistry. In conclusion, the finding that human macrophages produce endothelins suggests an important role for these peptides in the microenvironment of tissue macrophages. Macrophage-derived endothelins may have an essential function in blood vessel physiology, and aberrant production may contribute to vessel pathology.

Complaints of neuropathic pain, noxious cervical plexus neuropathy and neck tightness are reported by patients who undergo neck dissection: an institutional study and narrative review.

There exists a subgroup of patients who undergo neck dissection (ND) who postoperatively complain of either neuropathic pain, dysaesthesia and/or discomfort that is located within the dermatomal distribution of the cervical plexus. The purpose of our study was to determine the prevalence, characteristic, and demographics of these symptoms in our patient cohort. We undertook a retrospective randomised observational cohort study of 105 patients who had undergone ND. The primary predictor variable was the undertaking of a ND. The secondary outcome variable was the complaint of either neuropathic pain or a noxious neuropathy, at a minimum of twelve months after surgery. A recognised symptom questionnaire and a visual analogue score was employed for the purpose of the study. A descriptive and statistical analysis was applied to the assembled data. Twenty patients (19%) complained of either spontaneous (n=9) or evoked (n=11) neuropathic pain that occurred within the surgical site. In addition, 71 patients (68%) described an altered sensation in the dermatomal distribution of the great auricular or tranverse cervical nerves while 70 patients (67%) described the feeling of 'neck tightness'. There were no characteristics of the study cohort that underpinned these results. Neuropathic pain can occur following ND. This can cause distress to a small but defined group of patients. Despite its importance, we found a paucity of studies in the literature that have investigated neuropathic pain following ND. We believe this condition requires more research attention and clinical awareness.

Comparison of disease activity measures for anti-neutrophil cytoplasmic autoantibody (ANCA)-associated vasculitis.

AIM: Currently, several different instruments are used to measure disease activity and extent in clinical trials of anti-neutrophil cytoplasmic autoantibody (ANCA)-associated vasculitis, leading to division among investigative groups and difficulty comparing study results. An exercise comparing six different vasculitis instruments was performed. METHODS: A total of 10 experienced vasculitis investigators from 5 countries scored 20 cases in the literature of Wegener granulomatosis or microscopic polyangiitis using 6 disease assessment tools: the Birmingham Vasculitis Activity Score (BVAS), The BVAS for Wegener granulomatosis (BVAS/WG), BVAS 2003, a Physician Global Assessment (PGA), the Disease Extent Index (DEI) and the Five Factor Score (FFS). Five cases were rescored by all raters. RESULTS: Reliability of the measures was extremely high (intraclass correlations for the six measures all = 0.98). Within each instrument, there were no significant differences or outliers among the scores from the 10 investigators. Test/retest reliability was high for each measure: range = 0.77 to 0.95. The scores of the five acute activity measures correlated extremely well with one another. CONCLUSIONS: Currently available tools for measuring disease extent and activity in ANCA-associated vasculitis are highly correlated and reliable. These results provide investigators with confidence to compare different clinical trial data and helps form common ground as international research groups develop new, improved and universally accepted vasculitis disease assessment instruments.

Silver-Foil Psychrometer for Measuring Leaf Water Potential in situ.

The water potential of leaves in situ can be measured without temperature control with a miniature, single-junction psychrometer constructed from silver foil and attached to the leaf with a silver-impregnated, conductive coating. The temperature of the psychrometer has been found to stay within 0.025 degrees C of the temperature of a simulated leaf when the latter temperature was changing at a rate of 1 degrees C per minute. Leaf water potentials can be measured with a precision of +/- 1 bar, or better.

Atmospheric trace metals at remote northern and southern hemisphere sites: pollution or natural?

The chemical composition of atmospheric particles collected near sea level over the North Atlantic indicates that Al, Sc, Mn, Fe, Co, Cr, Na, Mg, Ca, K, and Sr are derived from either crustal weathering or the ocean. The elements V, Zn, Cu, Cd, Pb, Sb, and Se are present in concentrations higher than expected from these sources. Although the V is probably derived from pollution sources on the North American continent, a comparison of enrichment factors relative to average crustal material for the remainder of these elements over the North Atlantic with enrichment factors for similar samples collected at the geographic South Pole suggests that the anomalously high enrichment factors may be due to natural rather than anthropogenic sources. A vapor phase for these metals may be involved at their source.