P12.08.A Uncovering the glioblastoma tumor-microenvironment by high-end multiplexing with imaging mass cytometry

Background

Glioblastoma is one of the most aggressive cancers, and hypoxia plays an essential role in its tumor- microenvironment. Tumor-associated microglia and macrophages (TAMs) have been reported to constitute up to 30 % of the cells, a fraction that is even higher in hypoxic areas. Single-cell mRNA sequencing of glioblastoma tumors has revealed vast heterogeneity, but the spatial aspects are not entirely defined yet. The aim of this study was to uncover differences between the hypoxic and normoxic tumor-microenvironment of human glioblastoma by high-end multiplexing with imaging mass cytometry.

Material and Methods

A tissue microarray (TMA) with normoxic and hypoxic areas from 4 IDH-wildtype glioblastomas was prepared based on the hypoxia marker hypoxia-inducing factor 1 alpha (HIF1 alpha). The TMA was stained with 18 metal-tagged antibodies covering TAMs, lymphocytes, immune checkpoints, vessels, tumor cells and proliferation. The Hyperion-CYTOF technology was used to ablate the samples and the images were analyzed by MCD viewer, Visiopharm software, and customized R scripts.

Results

Single-cell analysis of 160 fields covering around 45,000 cells in the glioblastoma microenvironment revealed multiple cellular phenotypes. It was revealed that proliferating TAMs (IBA1+, Ki67+) were more frequent in hypoxia, whereas proliferating vessels (CD34+, Ki67+) were more frequent in normoxia. Additionally, proliferating stem-like tumor cells (OLIG-2+, Ki67+) were more frequent in normoxia regions.

Conclusion

Our study revealed multiple cellular phenotypes in the glioblastoma microenvironment. The TAMs, endothelial and tumor cell phenotypes revealed may play a critical role in glioblastoma biology however this needs to be elucidated in future studies.

Two subsets of human marginal zone B cells resolved by global analysis of lymphoid tissues and blood

B cells generate antibodies that are essential for immune protection, but their subgroups are poorly defined. Here, we perform undirected deep profiling of B cells in matched human lymphoid tissues from deceased transplant organ donors and blood. In addition to identifying unanticipated features of tissue-based B cell differentiation, we resolve two subsets of marginal zone B (MZB) cells differing in cell surface and transcriptomic profiles, clonal relationships to other subsets, enrichment of genes in the NOTCH pathway, distribution bias within splenic marginal zone microenvironment, and immunoglobulin repertoire diversity and hypermutation frequency. Each subset is present in spleen, gut-associated lymphoid tissue, mesenteric lymph nodes, and blood. MZB cells and the lineage from which they are derived are depleted in lupus nephritis. Here, we show that this depletion is of only one MZB subset. The other remains unchanged as a proportion of total B cells compared with health. Thus, it is important to factor MZB cell heterogeneity into studies of human B cell responses and pathology.

Disrupted Peyer's Patch Microanatomy in COVID-19 Including Germinal Centre Atrophy Independent of Local Virus

Confirmed SARS-coronavirus-2 infection with gastrointestinal symptoms and changes in microbiota associated with coronavirus disease 2019 (COVID-19) severity have been previously reported, but the disease impact on the architecture and cellularity of ileal Peyer's patches (PP) remains unknown. Here we analysed post-mortem tissues from throughout the gastrointestinal (GI) tract of patients who died with COVID-19. When virus was detected by PCR in the GI tract, immunohistochemistry identified virus in epithelium and lamina propria macrophages, but not in lymphoid tissues. Immunohistochemistry and imaging mass cytometry (IMC) analysis of ileal PP revealed depletion of germinal centres (GC), disruption of B cell/T cell zonation and decreased potential B and T cell interaction and lower nuclear density in COVID-19 patients. This occurred independent of the local viral levels. The changes in PP demonstrate that the ability to mount an intestinal immune response is compromised in severe COVID-19, which could contribute to observed dysbiosis.

Immunogenomics of Colorectal Cancer Response to Checkpoint Blockade: Analysis of the KEYNOTE 177 Trial and Validation Cohorts

BACKGROUND & AIMS

Colorectal cancer (CRC) shows variable response to immune checkpoint blockade, which can only partially be explained by high tumor mutational burden (TMB). We conducted an integrated study of the cancer tissue and associated tumor microenvironment (TME) from patients treated with pembrolizumab (KEYNOTE 177 clinical trial) or nivolumab to dissect the cellular and molecular determinants of response to anti- programmed cell death 1 (PD1) immunotherapy.

METHODS

We selected multiple regions per tumor showing variable T-cell infiltration for a total of 738 regions from 29 patients, divided into discovery and validation cohorts. We performed multiregional whole-exome and RNA sequencing of the tumor cells and integrated these with T-cell receptor sequencing, high-dimensional imaging mass cytometry, detection of programmed death-ligand 1 (PDL1) interaction in situ, multiplexed immunofluorescence, and computational spatial analysis of the TME.

RESULTS

In hypermutated CRCs, response to anti-PD1 immunotherapy was not associated with TMB but with high clonality of immunogenic mutations, clonally expanded T cells, low activation of Wnt signaling, deregulation of the interferon gamma pathway, and active immune escape mechanisms. Responsive hypermutated CRCs were also rich in cytotoxic and proliferating PD1+CD8 T cells interacting with PDL1+ antigen-presenting macrophages.

CONCLUSIONS

Our study clarified the limits of TMB as a predictor of response of CRC to anti-PD1 immunotherapy. It identified a population of antigen-presenting macrophages interacting with CD8 T cells that consistently segregate with response. We therefore concluded that anti-PD1 agents release the PD1-PDL1 interaction between CD8 T cells and macrophages to promote cytotoxic antitumor activity.

Sentiment Analysis of Journal Articles and News Articles Pertaining to CTE

Purpose

Past research has called for balance in the media when reporting on chronic traumatic encephalopathy (CTE) in order to avoid harmful bias on the readers. The call to do no harm in reporting is based on concerns that the media’s representation of CTE has moved far beyond what researchers studying the disease are able to prove. This study aimed to use positive and negative word sentiments to directly compare journal articles with corresponding news articles in order to evaluate these concerns.

Methods

Research articles (n=7) directly associated with CTE that were heavily covered in the media, as well as associated media articles (n=7) from reputable news sites that covered only the associated article, were selected for the sample. The “AFINN” sentiment analysis dictionary rates the emotional valence of each word with an integer between minus three (negative) and plus three (positive). Words not recognized by the dictionary or with a zero weight were omitted from the analyses.

Results

The entire word list from journal articles weighted equally produced a mean sentiment of -1.001, while news articles using the same scale produce a mean of -0.746. However, when the means were weighted against word count, the mean sentiment score for journal articles was -0.135 and for news article -0.137. A paired t-test analysis of the weighted group of articles yielded no significant difference between the two groups before (p= 0.72) and after (p=0.69) the word count weighted analysis.

Conclusion

Despite recent calls for a less biased reporting of CTE in the mainstream media, this analysis indicates equal sentimental weighting between peer-reviewed journal articles and news reports on CTE, which each approached a value of zero (true neutrality).

Spatiotemporal segregation of human marginal zone and memory B cell populations in lymphoid tissue

Human memory B cells and marginal zone (MZ) B cells share common features such as the expression of CD27 and somatic mutations in their IGHV and BCL6 genes, but the relationship between them is controversial. Here, we show phenotypic progression within lymphoid tissues as MZ B cells emerge from the mature naïve B cell pool via a precursor CD27-CD45RBMEM55+ population distant from memory cells. By imaging mass cytometry, we find that MZ B cells and memory B cells occupy different microanatomical niches in organised gut lymphoid tissues. Both populations disseminate widely between distant lymphoid tissues and blood, and both diversify their IGHV repertoire in gut germinal centres (GC), but nevertheless remain largely clonally separate. MZ B cells are therefore not developmentally contiguous with or analogous to classical memory B cells despite their shared ability to transit through GC, where somatic mutations are acquired.

Phase II study of calcitriol-enhanced docetaxel in patients with previously untreated metastatic or locally advanced pancreatic cancer

PURPOSE

To determine the safety and efficacy of weekly high-dose oral calcitriol and docetaxel, given to patients with non-resectable, incurable pancreatic cancer.

PATIENTS AND METHODS

Twenty-five patients were enrolled onto this phase II study. Patients were treated with oral calcitriol 0.5 microg/kg on day 1, followed by docetaxel 36 mg/m(2) IV on day 2, administered weekly for three consecutive weeks, followed by 1 week without treatment. Patients followed a low-calcium diet and increased their hydration. The primary end-point of the trial was time-to-progression.

RESULTS

Three of 25 patients attained a partial response (12%, 95% CI 3 to 31) and seven (28%) achieved stable disease. Median time-to-progression was 15 weeks, and median overall survival was 24 weeks. Toxicities observed (hyperglycemia, fatigue) were mostly attributable to the docetaxel or its pre-treatment.

CONCLUSIONS

This regimen of high-dose calcitriol with docetaxel may have activity in incurable pancreatic cancer, with a modest increase in TTP when compared to historical findings using single-agent docetaxel. However, results do not appear superior to those seen with gemcitabine, with or without erlotinib.

A phase II trial of high-dose calcitriol and docetaxel in patients with untreated, incurable pancreatic adenocarcinoma

15099

Background: Taxanes have activity in patients with advanced pancreatic adenocarcinoma. In preclinical studies, calcitriol, the active form of vitamin D, potentiates docetaxel-induced cell death in pancreatic and prostatic cancer cell lines. Clinically, single institution and randomized prostate cancer trials using weekly high-dose calcitriol with docetaxel have demonstrated high PSA response rates (J Clin Oncol 2003, 2007). Herein we report results from a phase II study of the identical regimen in patients with incurable pancreatic adenocarcinoma. Methods: Patients with a histologic diagnosis of locally advanced or metastatic pancreatic adenocarcinoma, Zubrod PS 0–2, and adequate organ function were eligible. Previous non-docetaxel adjuvant chemotherapy and radiation were permissible. Patients received calcitriol 0.5 mcg/kg orally day 1, followed by docetaxel 36 mg/m2 on day 2. Therapy was given weekly for 3 weeks, followed by a 1 week break, and patients were treated until progression. The primary endpoint was time-to-progression (TTP). Results: 24 patients with metastatic and 1 with locally advanced (25 total) were enrolled, treated and are evaluable for efficacy and toxicity. Median age and PS were 60 (range 30 to 79) and 1, respectively. 68% were males, and all were white. Three patients are alive and 22 have died. The median number of cycles was 1 (range 0 to 12). 3 patients (12%, 95% CI 3 to 31) achieved a partial response, and 7 (28%) stable disease for at least 7 weeks. Median TTP and median overall survival were 2.2 and 5 months respectively. Potentially treatment-related common grade 3/4 toxicities included: thrombosis -12%, abnormal LFTs-16%, nausea-8%, fatigue-16%, infection-12%, neutropenia/leucopenia-16%, effusion-8%, abnormal electrolytes-24%, and infusion reaction-4%. Conclusions: The combination of docetaxel and high-dose calcitriol has activity in pts with advanced pancreatic cancer, but the regimen offers no apparent advantage over historical results achieved with standard gemcitabine.

No significant financial relationships to disclose.

Transport measurements across a tunable potential barrier in graphene

The peculiar nature of electron scattering in graphene is among many exciting theoretical predictions for the physical properties of this material. To investigate electron scattering properties in a graphene plane, we have created a gate-tunable potential barrier within a single-layer graphene sheet. We report measurements of electrical transport across this structure as the tunable barrier potential is swept through a range of heights. When the barrier is sufficiently strong to form a bipolar junction (n-p-n or p-n-p) within the graphene sheet, the resistance across the barrier sharply increases. We compare these results to predictions for both diffusive and ballistic transport, as the barrier rises on a length scale comparable to the mean free path. Finally, we show how a magnetic field modifies transport across the barrier.

The effects of a 12-week group exercise programme on physiological and psychological variables and function in overweight women

OBJECTIVES

The aim of this study was to investigate the effect of a 12-week functional exercise programme on overweight women.

METHODS

Twenty-six subjects (n=13 exercisers, n=13 controls) aged (mean+/-SD) 63 (+/-4) years completed the study. The exercise sessions were carried out twice each week for 12 weeks. The variables measured were body mass, body mass index, skin-fold thickness, resting blood pressure, total blood cholesterol, chair rise, timed 'up and go' test, 20-m walk,lifting a 1- and a 2-kg bag on to a shelf, stair walking, 'sit and reach' flexibility test, Life Satisfaction Index and Physical Self-perception Profile for Older Adults. The exercise sessions consisted of 40-min sessions during which the subjects performed aerobic and strength exercises.

RESULTS

Paired analyses showed that body mass, body mass index, blood pressure (systolic and diastolic values), 'up and go' time, time to complete a 20-m walk, time to lift a 1- and a 2-kg bag with both the right and left arms onto a shelf, and stair climbing-total time and ascent time-decreased significantly in the exercise group. Also, the exercise group improved their Life Satisfaction Index score significantly compared with the control group.

CONCLUSIONS

The results indicate that a functional exercise programme has the potential to improve performance in a number of physiological variables and functional activities in overweight women. The exercise programme enhanced life satisfaction.

The Living with Cancer Education Programme. I. Development of an Australian education and support programme for cancer patients and their family and friends

After a diagnosis of cancer, patients and their families and friends experience a significant need for information about the illness, treatment and prognosis, as well as support. Structured education and support group-based programmes play a major role in meeting these needs. Following a needs assessment in 1985, the Anti-Cancer Council of Victoria (ACCV), Australia, initiated development of the Living With Cancer Education Programme (LWCEP), a structured 8-week group programme providing education and support for people with cancer and their families and friends. This paper provides an historical overview of the LWCEP, as well as an outline of the programme aims, structure, content and delivery. Recent developments and future directions are also discussed. These include adaptation of the programme for individuals with advanced or recurrent cancer, modification of the programme structure and revision of the evaluation methodology.

The Living with Cancer Education Programme. II. Evaluation of an Australian education and support programme for cancer patients and their family and friends

A diagnosis of cancer can have major adverse physical, psychosocial and economic consequences for both the individual diagnosed with cancer and their family and friends. The provision of adequate information and support to individuals affected by cancer plays a key role in facilitating better adjustment and coping. Psychoeducational group programmes are an effective way of meeting this need. This paper reports on the results of an evaluation of an Australian education and support programme for individuals with cancer and their family and friends - the Living with Cancer Education Programme (LWCEP). Data are presented based on the evaluation of 152 programmes involving 1460 participants conducted between 1994 and 2000. Participant responses related to changes in self, general coping abilities and satisfaction with the programme are reported. Results showed high satisfaction with the programme and significant improvement in coping abilities, knowledge and communication and relationships with significant others and health professionals among both groups of participants. These findings highlight several important issues for professionals involved in the psychosocial care of cancer patients and their family and friends.

A comparison of physiological responses and rating of perceived exertion in two modes of aerobic exercise in men and women over 50 years of age

OBJECTIVES

To compare the physiological responses and ratings of perceived exertion to aerobic dance and walking sessions completed at a self selected pace.

METHODS

Six women and six men with a sample mean (SD) age of 68 (7) years completed aerobic dance and walking sessions in random order. A treadmill test was performed by each subject from which peak oxygen uptake (.VO(2)) and maximum heart rates (HRmax) were determined. During the aerobic dance and walking sessions, heart rate and .VO(2) were measured continuously throughout. Rate of perceived exertion (RPE) was measured every three minutes throughout the session.

RESULTS

The sample means (SD) for %peak .VO(2) were 67 (17)% for the aerobic dance sessions and 52 (10)% for the walking sessions, and the %HRmax sample means (SD) were 74 (12)% for the aerobic dance sessions and 60(8)% for walking sessions. The sample mean (SD) RPE for the aerobic dance sessions was 11(2), and for the walking sessions it was 10(2).

CONCLUSIONS

%peak .VO(2), %HRmax, and RPE were significantly higher for aerobic dance than for walking. However, both the aerobic dance and walking sessions were of adequate intensity to improve aerobic fitness in most subjects. Further investigation into the relation between RPE and %peak .VO(2) in a field setting over representative exercise time periods would be useful.

Diet, evolution and aging--the pathophysiologic effects of the post-agricultural inversion of the potassium-to-sodium and base-to-chloride ratios in the human diet

Theoretically, we humans should be better adapted physiologically to the diet our ancestors were exposed to during millions of years of hominid evolution than to the diet we have been eating since the agricultural revolution a mere 10,000 years ago, and since industrialization only 200 years ago. Among the many health problems resulting from this mismatch between our genetically determined nutritional requirements and our current diet, some might be a consequence in part of the deficiency of potassium alkali salts (K-base), which are amply present in the plant foods that our ancestors ate in abundance, and the exchange of those salts for sodium chloride (NaCl), which has been incorporated copiously into the contemporary diet, which at the same time is meager in K-base-rich plant foods. Deficiency of K-base in the diet increases the net systemic acid load imposed by the diet. We know that clinically-recognized chronic metabolic acidosis has deleterious effects on the body, including growth retardation in children, decreased muscle and bone mass in adults, and kidney stone formation, and that correction of acidosis can ameliorate those conditions. Is it possible that a lifetime of eating diets that deliver evolutionarily superphysiologic loads of acid to the body contribute to the decrease in bone and muscle mass, and growth hormone secretion, which occur normally with age? That is, are contemporary humans suffering from the consequences of chronic, diet-induced low-grade systemic metabolic acidosis? Our group has shown that contemporary net acid-producing diets do indeed characteristically produce a low-grade systemic metabolic acidosis in otherwise healthy adult subjects, and that the degree of acidosis increases with age, in relation to the normally occurring age-related decline in renal functional capacity. We also found that neutralization of the diet net acid load with dietary supplements of potassium bicarbonate (KHCO3) improved calcium and phosphorus balances, reduced bone resorption rates, improved nitrogen balance, and mitigated the normally occurring age-related decline in growth hormone secretion--all without restricting dietary NaCl. Moreover, we found that co-administration of an alkalinizing salt of potassium (potassium citrate) with NaCl prevented NaCl from increasing urinary calcium excretion and bone resorption, as occurred with NaCl administration alone. Earlier studies estimated dietary acid load from the amount of animal protein in the diet, inasmuch as protein metabolism yields sulfuric acid as an end-product. In cross-cultural epidemiologic studies, Abelow found that hip fracture incidence in older women correlated with animal protein intake, and they suggested a causal relation to the acid load from protein. Those studies did not consider the effect of potential sources of base in the diet. We considered that estimating the net acid load of the diet (i. e., acid minus base) would require considering also the intake of plant foods, many of which are rich sources of K-base, or more precisely base precursors, substances like organic anions that the body metabolizes to bicarbonate. In following up the findings of Abelow et al., we found that plant food intake tended to be protective against hip fracture, and that hip fracture incidence among countries correlated inversely with the ratio of plant-to-animal food intake. These findings were confirmed in a more homogeneous population of white elderly women residents of the U.S. These findings support affirmative answers to the questions we asked above. Can we provide dietary guidelines for controlling dietary net acid loads to minimize or eliminate diet-induced and age-amplified chronic low-grade metabolic acidosis and its pathophysiological sequelae. We discuss the use of algorithms to predict the diet net acid and provide nutritionists and clinicians with relatively simple and reliable methods for determining and controlling the net acid load of the diet. A more difficult question is what level of acidosis is acceptable. We argue that any level of acidosis may be unacceptable from an evolutionarily perspective, and indeed, that a low-grade metabolic alkalosis may be the optimal acid-base state for humans.

Interim results of the study of particulates and health in Atlanta (SOPHIA)

Substantial evidence supports an association of particulate matter (PM) with cardiorespiratory illnesses, but little is known regarding characteristics of PM that might contribute to this association and the mechanisms of action. The Atlanta superstation sponsored by the Electric Power Research Institute as part of the Aerosol Research and Inhalation Epidemiology Study (ARIES) study is monitoring chemical composition of ambient particles by size fraction, as well as a comprehensive suite of other pollutants, at a site in downtown Atlanta during the 25-month period, August 1, 1998-August 31, 2000. Our investigative team is making use of this unique resource in several morbidity studies, called the "Study of Particulates and Health in Atlanta (SOPHIA)". The study includes the following components: (1) a time series investigation of emergency department (ED) visits for the period during which the superstation is operating; (2) a time series investigation of ED visits during the 5 years prior to implementation of the superstation; and (3) a study of arrhythmic events in patients equipped with automatic implantable cardioverter defibrillators (AICDs) for the period January 1, 1993-August 31, 2000. Thirty-three of 39 Atlanta area EDs are participating in the ED studies, comprising over a million annual ED visits. In this paper, we present initial analyses of data from 18 of the 33 participating EDs. The preliminary data set includes 1,662,713 ED visits during the pre-superstation time period and 559,480 visits during the superstation time period. Visits for four case groupings--asthma, chronic obstructive pulmonary disease (COPD), dysrhythmia, and all cardiovascular diseases (CVDs) combined--have been assessed relative to daily air quality indices, controlling for long-term temporal trends and meteorologic variables, using general linear models, generalized estimating equations and generalized additive models. Single-pollutant models predicting case visitation rates using moving averages of 0-, 1-, and 2-day lagged air quality variables were run. For the pre-superstation period, PM10 (24-h), ozone (8-h), SO2 (1-h), NO2 (1-h) and CO (1-h) were studied. For the first 12 months of superstation operation, the following air quality variables of a priori interest were available: ozone (8-h), NO2 (1-h), SO2 (1-h), CO (1-h), and 24-h measurements of PM10, coarse PM (PM 2.5-10 microm), PM2.5, polar VOCs, 10-100 nm particulate count and surface area, and in the PM2.5 fraction: sulfates, acidity, water-soluble metals, organic matter (OM), and elemental carbon (EC). During the pre-superstation time period, statistically significant, positive associations were observed for adult asthma with ozone, and for COPD with ozone, NO2 and PM10. During the superstation time period, the following statistically significant, positive associations were observed: dysrhythmia with CO, coarse PM, and PM2.5 EC; and all CVDs with CO, PM2.5 EC and PM2.5 OM. While covariation of many of the air quality indices limits the informativeness of this analysis, the study provides one of the first assessments of PM components in relation to ED visits.

Mechanisms of selective neuronal cell death due to thiamine deficiency

Multiple mechanisms contribute to the selective brain lesions observed in WKS and experimental thiamine deficiency. Recent evidence of early microglial activation and increased free radical production suggest that oxidative stress processes play an important early role in the brain damage associated with thiamine deficiency.

Manganese deposition in basal ganglia structures results from both portal-systemic shunting and liver dysfunction

BACKGROUND & AIMS

Manganese (Mn) deposition could be responsible for the T(1)-weighted magnetic resonance signal hyperintensities observed in cirrhotic patients. These experiments were designed to assess the regional specificity of the Mn increases as well as their relationship to portal-systemic shunting or hepatobiliary dysfunction.

METHODS

Mn concentrations were measured in (1) brain samples from basal ganglia structures (pallidum, putamen, caudate nucleus) and cerebral cortical structures (frontal, occipital cortex) obtained at autopsy from 12 cirrhotic patients who died in hepatic coma and from 12 matched controls; and from (2) brain samples (caudate/putamen, globus pallidus, frontal cortex) from groups (n = 8) of rats either with end-to-side portacaval anastomosis, with biliary cirrhosis, or with fulminant hepatic failure as well as from sham-operated and normal rats.

RESULTS

Mn content was significantly increased in frontal cortex (by 38%), occipital cortex (by 55%), pallidum (by 186%), putamen (by 66%), and caudate (by 54%) of cirrhotic patients compared with controls. Brain Mn content did not correlate with patient age, etiology of cirrhosis, or history of chronic hepatic encephalopathy. In cirrhotic and portacaval-shunted rats, Mn content was increased in pallidum (by 27% and 57%, respectively) and in caudate/putamen (by 57% and 67%, respectively) compared with control groups. Mn concentration in pallidum was significantly higher in portacaval-shunted rats than in cirrhotic rats. No significant changes in brain Mn concentrations were observed in rats with acute liver failure.

CONCLUSIONS

These findings suggest that brain Mn deposition results both from portal-systemic shunting and from liver dysfunction.

Selective cervical spine radiography in blunt trauma: methodology of the National Emergency X-Radiography Utilization Study (NEXUS)

Fear of failure to identify cervical spine injury has led to extremely liberal use of radiography in patients with blunt trauma and remotely possible neck injury. A number of previous retrospective and small prospective studies have tried to address the question of whether any clinical criteria can identify patients, from among this group, at sufficiently low risk that cervical spine radiography is unnecessary. The National Emergency X-Radiography Utilization Study (NEXUS) is a very large, federally supported, multicenter, prospective study designed to define the sensitivity, for detecting significant cervical spine injury, of criteria previously shown to have high negative predictive value. Done at 23 different emergency departments across the United States and projected to enroll more than 20 times as many patients with cervical spine injury than any previous study, NEXUS should be able to answer definitively questions about the validity and reliability of clinical criteria used as a preliminary screen for cervical spine injury.

An integrated YAC map of the human X chromosome

The human X chromosome is associated with a large number of disease phenotypes, principally because of its unique mode of inheritance that tends to reveal all recessive disorders in males. With the longer term goal of identifying and characterizing most of these genes, we have adopted a chromosome-wide strategy to establish a YAC contig map. We have performed > 3250 inter Alu-PCR product hybridizations to identify overlaps between YAC clones. Positional information associated with many of these YAC clones has been derived from our Reference Library Database and a variety of other public sources. We have constructed a YAC contig map of the X chromosome covering 125 Mb of DNA in 25 contigs and containing 906 YAC clones. These contigs have been verified extensively by FISH and by gel and hybridization fingerprinting techniques. This independently derived map exceeds the coverage of recently reported X chromosome maps built as part of whole-genome YAC maps.

Inducibility of metallothionein mRNA expression and cadmium tolerance in larvae of a marine teleost, the turbot (Scophthalmus maximus)

An acute (48-hr) lethal toxicity study of turbot at various stages from hatch to juveniles showed that prior to first exogenous feeding, larvae of turbot were an order of magnitude more sensitive to cadmium toxicity than later developmental stages (LC50 of 0.18-0.23 ppm Cd versus 2-5 ppm Cd). To investigate the possible role of metallothionein (MT) in Cd tolerance, the concentrations of MT mRNA were determined in control and Cd-exposed animals using a plaice MT cDNA probe. MT mRNA was expressed throughout embryonic and early larval development at levels approximately twice those in juvenile turbot liver apart from the period around hatching, when there was a decreased level of expression. During endogenous feeding, despite larval drinking, MT mRNA levels did not appear to be inducible by exposure to Cd in the water within 3 days of hatching but were induced three- to fivefold after 48 hr exposure to waterborne Cd at all later stages of development. The results suggest that Cd tolerance is associated with metal induction of MT gene transcription and that the enhanced sensitivity of very early stage larvae is attributable to a deficiency in MT gene transcription.

Additive effects of glyburide and antidepressants in the forced swimming test: evidence for the involvement of potassium channel blockade

Evidence in the literature suggests that the modulatory effects of antidepressant drugs (ADS) on neuronal excitability, via the inhibition of K+ channels, may be the final common pathway of pharmacological action. Therefore, we tested the hypothesis that combining the ATP-sensitive K+ channel blocker glyburide with a variety of ADS would produce an additive effect and decrease the immobility time of mice in the forced swimming test (FST). Glyburide (GLY, IP, 30 and 50 mg/kg) and subactive doses of ADS were administered 45 and 30 min, respectively, prior to behavioral testing. Results showed that when combined with GLY, ADS whose main pharmacological effect is one of 5-HT uptake blockade (imipramine, amitriptyline, citalopram, paroxetine, fluoxetine, and fluvoxamine) were more effective in decreasing the amount of time mice were immobile, than when these drugs were administered alone. Some noradrenaline uptake inhibiting ADS (desipramine and viloxazine, but not maprotiline) were also significantly more effective in decreasing immobility time when combined with GLY than when administered alone. Pretreatment with GLY was found to have no effect on the dopamine uptake inhibitor bupropion, and out of the atypical ADS tested (trazodone, mianserine and iprindole), only coadministration with iprindole decreased the immobility time. Only the specific MAO-A inhibitor moclobemide was observed to have an antiimmobility effect when combined with GLY. Neither MAO-B specific (RO 16 6491) nor mixed MAO inhibitors (nialamide and pargyline) interacted with GLY to produce antiimmobility effects. These results corroborate and extend our previous report of the ADS enhancing effects of quinine in the same behavioral model, and suggest that the additive effects of quinine and GLY on ADS in FST are a result of K+ channel blockade.

Regulation of metallothionein in teleosts: induction of MTmRNA and protein by cadmium in hepatic and extrahepatic tissues of a marine flatfish, the turbot (Scophthalmus maximus)

Synthesis of the heavy metal-binding protein metallothionein (MT) was determined in the major organs of accumulation of Cd (liver, kidney and gills) of a marine flatfish, the turbot, after intraperitoneal (i.p.) administration of varying doses of Cd. Synthesis of MTmRNA and MT were linearly related to dose only at low Cd dosages (up to ca. 100 micrograms Cd/kg). Induction of MTmRNA was rapid, peaking 1-2 days after Cd administration in gills and kidneys, at 4 days in liver. In all three tissues, at low doses of Cd, MTmRNA levels declined with an apparent half life of 5-7 days and for a given dose of Cd, similar MTmRNA concentrations were attained. Induction of MT levels temporally followed that of MTmRNA. Steady state levels of MT were attained more quickly at a low dose of Cd. At acute Cd doses of > 200 micrograms Cd/kg, MT gene transcription and protein translation appeared to be progressively reduced, inferring that the rate of MT synthesis was limiting due to cytotoxicity of the high acute Cd dosage. In contrast to MTmRNA levels which were induced to similar levels in the three tissues, MT levels decreased in the order liver > kidneys > gills implying differences in translational processes.

Comparison of selection of preoperative laboratory tests: the computer vs the anaesthetist

HealthQuiz II (HQII) is a computerized history-taking device which can be used by patients before anaesthesia and surgery. HealthQuiz II provides a summary of symptoms, a modified ASA Classification, and a list of suggested laboratory tests. Developed at the University of Chicago, the device has not been evaluated in Canada. The purpose of this study was to compare preoperative evaluation and selection of laboratory tests by a group of Canadian anaesthetists using traditional methods versus using HealthQuiz II. Twenty-seven anaesthetists from three (Western) Canadian University teaching hospitals participated in the study. The subjects were male, aged between 30-50 yr, trained in Canada and practicing in Calgary, Edmonton and Vancouver. They were asked to self-evaluate and select laboratory tests and then to complete the HQII protocol, the day before a proposed mock operation. Results of this comparison showed that the ASA scores assigned by HQII were higher for 11 subjects and lower for two. Eight anaesthetists thought HQII asked questions which they omitted while five thought HQII overlooked items. Thirteen anaesthetists believed HQII would be a useful adjunct to their practice. Only ten anaesthetists requested any tests while HealthQuiz II suggested tests for 23 subjects, with an average of 1.9 tests/subject (anaesthetists) vs 5.4 tests/subject (HQII). The total cost of tests selected by anaesthetists was $272.15 in contrast with $1,513.20 for those suggested by HQII. We conclude that rationale for test selection may have contributed to the difference in number and costs of tests.

The influence of preoperative donor factors on the performance of the isolated perfused human pancreas

The present study was undertaken to determine whether there exist specific donor factors which influence the performance of the isolated perfused human pancreas with respect to the sustained level of insulin secretion. Donor factors included age, serum glucose, hospital days, CMV status, RBC transfusion history, and smoking history. Following pancreas procurement, single-pass perfusion was performed in pancreata obtained from 35 cadaveric organ donors using a modified Krebs buffer. Aliquots were collected every 2 min and assayed for insulin concentration. Data was analyzed for 120 min for each pancreas. The mean initial insulin concentration was 2989 +/- 383 microU/ml and the insulin concentration at 120 min averaged 1467 +/- 338 microU/ml. The mean decay of insulin secretion over time was -13 +/- 3.2 microU/ml/min. Multiple regression analysis demonstrated that pancreata from donors who had a smoking history had a faster rate of decay of insulin secretion than pancreata from nonsmokers (P = 0.04). None of the other above mentioned donor factors significantly affected decay of insulin secretion. This analysis suggests that a history of smoking in organ donors results in a significantly faster rate of decay of insulin secretion when the pancreas is utilized for the laboratory model. We conclude that it is important to evaluate specific donor factors of cadaveric organ donors prior to the use of the human organs for experimental purposes.

Infection control for health care workers caring for critically injured patients: a national survey

Prevention of transmission of bloodborne pathogens to health care workers (HCWs) involved in resuscitation of critically injured patients presents special challenges. As a step toward creation of a standard, a telephone survey of the infection control practices in this setting of the 100 busiest EDs in the United States (US) was performed. Departmental staff who were knowledgeable about ED infection prevention protocols were questioned about general policy, barrier protection measures, sharps management, and educational programs directed to HCWs. Surveys were completed for 82 EDs. Of these, 56 (68%) either function as primary trauma care facilities for the local community, or are designated level 1 trauma centers by the American College of Surgeons. Specific infection control protocols for trauma resuscitation had been printed and posted by 18 EDs (22%), with the remaining 64 (78%) using the same universal precautions for care of the severely injured as for other patients. A specific policy relating to invasive procedures had been promulgated by 66 EDs (80%). Barrier protection was used by protocol or by custom for care of all critically injured patients by 43 EDs (52%). Impermeable gowns with sleeves were available in 63 EDs (77%). Eye or face protection included face shields by 74 EDs (90%), face masks by 76 EDs (93%), and goggles by 72 EDs (88%). Only 59 EDs (72%) reported that sharp containers were always within arm's reach of HCWs with material to discard. Specially adapted equipment included self-sheathing intravenous catheters (21, 26%) and needle/syringe combinations (16, 20%). Considerable variation exists in infection control practices in busy US EDs during resuscitation of critically injured patients.(ABSTRACT TRUNCATED AT 250 WORDS)

Survival outcome among 54 intubated pediatric bone marrow transplant patients

OBJECTIVES

To assess the outcome of children who required endotracheal intubation after bone marrow transplantation and to determine whether prognostic indicators that might assist decision-making regarding the institution of mechanical ventilation could be identified.

DESIGN

Retrospective chart review.

SETTING

Critical care, reverse isolation unit at a university hospital.

PATIENTS

Fifty-four pediatric bone marrow transplant recipients who required endotracheal intubation.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

The following variables were assessed for effect on survival: a) the presence of additional nonhematoporetic organ system failure; b) the duration of required ventilatory assistance; c) the etiology of respiratory failure; d) the presence of significant graft vs. host disease; and e) the underlying disease for which the transplant was done. Six of 54 intubated pediatric bone marrow transplant recipients were extubated and discharged from the hospital. No patient with a diagnosis of leukemia or with multiple organ system failure could be extubated or discharged from the hospital. The presence of pulmonary parenchymal disease indicated poor prognosis for survival.

CONCLUSIONS

The decision to intubate a pediatric bone marrow transplant patient remains a difficult one. In this population, multiple organ system failure and primary pulmonary parenchymal disease were associated with a high mortality rate. These factors should be taken into account before and throughout the course of mechanical ventilation in this patient population.

Legally speaking: when dentistry and government clash in court

This article focuses on ADA advocacy in the courts. As these cases illustrate, organized dentistry's relationship can be adversial when cooperation fails. But that doesn't mean there is no room for agreement.

Prospective analysis of mental status progression in ethanol-intoxicated patients

Distinguishing patients with uncomplicated ethanol intoxication from intoxicated patients with other causes of mental status depression is a common clinical dilemma. The authors serially tested mental status in a group of ethanol-intoxicated patients to determine the interval over which mental status changes could be attributed to uncomplicated intoxication. Study patients were identified by (1) admission breath ethanol greater than or equal to 100 mg/dL; (2) ethanol-related impairment necessitating further observation or treatment; and (3) not critically ill or exhibiting focal neurologic signs. Mental status scores (sums of specific indices of alertness, orientation, and agitation) were determined initially, 1 hour after arrival, then every 2 hours. Causes of mental status depression other than acute intoxication were diagnosed in 16 patients, while another 18 failed to completely normalize mental status by the time of emergency department discharge or hospital admission. The remaining 71 with uncomplicated ethanol intoxication required (mean +/- SD) 3.2 +/- 3.6 hours to normalize mental status scores. A large proportion, however, took considerably longer to normalize mental status: 15 (21%) took 7 or more hours, and three (4%) took as long as 11 hours. Although patients with ethanol-associated depression of mental status lasting 3 hours after emergency department admission should be carefully evaluated for other causes of mental status abnormalities, the authors' observations indicate considerable individual variation in the duration of mental status depression caused by uncomplicated ethanol intoxication.

Effect of body locale and addition of epinephrine on the duration of action of a local anesthetic agent

STUDY OBJECTIVE

Little information exists relating body locale to the duration of action of local anesthetics. We tested the duration of action of a local anesthetic with and without epinephrine at different body locales.

PARTICIPANTS

Twenty healthy volunteers aged 27 to 48 years (mean, 32.0 years).

INTERVENTIONS

In the first of two experiments (L), 20 subjects had 1 mL buffered 1% lidocaine injected intradermally on the forehead, hand, forearm, and calf. In the second experiment (LE), ten subjects were injected at the same sites with lidocaine containing epinephrine.

METHODS

Subjects ranked anesthesia by reaction to pinprick from 0 (complete) to 20 (none) on a scale with testing done every 15 (L) or 30 (LE) minutes and continued until no anesthetic effect was present. Duration of effective and of any anesthesia were times until score of more than 5 and of more than 19, respectively. Mean duration of anesthesia was compared by analysis of variance (between body areas) and paired two-tailed t-test (L vs LE). Significance was taken as P less than or equal to .05.

RESULTS

Anesthesia was significantly briefer for the face than for all other body locales by both indexes of duration and for both plain lidocaine and lidocaine with epinephrine (P less than .001 to P less than .05). Anesthesia with epinephrine lasted significantly longer than with lidocaine alone at all body locales and for duration of both effective or any anesthesia (P = .0001 to P = .001). Based on 95% confidence interval limits, the duration of anesthesia at other body locales is predicted to be 1.3- to 3.2-fold that on the face. Confidence interval analysis indicated that addition of epinephrine to lidocaine increases the duration of anesthetic action by 1.3- to 13.0-fold that of lidocaine alone.

CONCLUSION

The duration of action of local anesthesia is considerably shorter for the face than for other body areas. Epinephrine significantly increases the duration of action of lidocaine at all body locales.

PVD: nurse--patient interventions

The intervention program described began with teaching patients in simple terms about PVD, associated risk factors, and why change is important. Teaching aids such as posters and booklets were used to supplement discussion. Positive reinforcement was emphasized. Phone calls, follow-up visits, encouragement and praise were frequent. Newsletters focusing on different aspects of the various risk factors were developed and mailed monthly. Patients were encouraged and helped to develop an individualized program of change based on discussions and practicality. They were encouraged to start slowly and increase gradually. Emphasis was placed on reinforcement, self-help, and praise for efforts. Patients were encouraged to keep a brief daily log of progress and thoughts. Regularly scheduled physical assessments provided a tool to assess change and provide tangible evidence of their ability to set a goal, follow through, and make life-style change.

Incidence of cocaine-associated rhabdomyolysis

STUDY HYPOTHESIS

Rhabdomyolysis is a common complication of cocaine use, and muscle symptoms fail to predict its development.

STUDY POPULATION

A prospective, convenience sample of patients presenting to the emergency department of a large inner-city hospital with complaints related to cocaine use were eligible for inclusion. Patients were excluded if they had other potential causes of elevated creatine kinase (CK) levels or rhabdomyolysis. A control group comprised patients who were not cocaine users and satisfied the exclusion criteria. Sixty-eight patients were studied.

METHODS

Initial evaluation included determination of the presence of muscle pain or swelling and total CK levels. Patients with a CK level of more than 800 U/L had additional tests, including a urine myoglobin, urine drug screen, and serum phosphorus. Rhabdomyolysis was defined by a serum CK level of more than 1,000 U/L (more than fivefold that of normal). CK levels were compared by two-tailed Student's t test. Muscle symptoms were compared with the development of rhabdomyolysis by Fisher's exact test.

RESULTS

The CK level in the cocaine group was 931 +/- 1,785 U/L (mean +/- 1 SD). The CK level in the control group was 242 +/- 168 U/L (P = .028). Of the cocaine users, 24% (eight of 34) had rhabdomyolysis; one developed multiorgan failure and died. No patient in the control group had a CK level of more than 1,000 U/L. Only one cocaine user who developed rhabdomyolysis had muscle symptoms. Three cocaine users had muscle symptoms but did not develop rhabdomyolysis. No patient in the control group had muscle symptoms or developed rhabdomyolysis. Muscle symptoms did not predict the CK level (P = .55).

CONCLUSION

This study revealed that 24% of the cocaine users had rhabdomyolysis. Many of the cases of rhabdomyolysis were not predictable from history or physical examination, making laboratory evaluation essential.