471 Assessing the Accuracy and Bias of Digital Symptom Checkers with Myocardial Infarction Patients

Aim

The accuracy and safety of symptom checkers in diagnosing and triaging patients is of concern; especially those with life-threatening conditions. The study's aims were to: 1. assess the accuracy of symptom checkers in diagnosing and triaging myocardial infarctions (MI) and, 2. determine whether differences in gender or presentation type exist.

Method

This prospective diagnostic accuracy study assessed 8 symptom checkers using 100 MI patients of various presentations: typical or atypical. The ability of a symptom checker in providing MI as the first diagnosis (D1) and the first 3 (D3) diagnoses were diagnostic accuracy measures. Triage advice was deemed correct if the symptom checker recommended seeking emergency treatment.

Results

Symptom checkers correctly diagnosed 48.0±31.4% of cases with MI first. D3 accuracy was 72.6±20.2%. Mean triage accuracy was 82.6±12.6%.

24.0±16.2% of atypical cases had a correct primary diagnosis. D3 accuracy for atypical MI was 43.8±20.6%, significantly lower than that of typical MI (p<0.01). Atypical case triage accuracy was 52.7±20.0%, significantly lower than typical cases (84.2±14.7%, p<0.01).

10.0% of the atypical female cases were diagnosed correctly with MI as the first diagnosis. Female atypical cases had significantly lower accuracy than typical female cases for all accuracy measures (p<0.01).

Conclusions

Symptom checkers generally provide low accuracy for diagnosing MI. Approximately 20% of cases were under-triaged. Results varied between symptom checkers: patients who presented with atypical symptoms tended to be under-diagnosed and under-triaged, especially those who were female. This demonstrated potential gender bias and therefore raises questions regarding symptom checker regulation and safety.

Neutrophilic inflammation promotes SARS-CoV-2 infectivity and augments the inflammatory responses in airway epithelial cells

In response to viral infection, neutrophils release inflammatory mediators as part of the innate immune response, contributing to pathogen clearance through virus internalization and killing. Pre-existing co- morbidities correlating to incidence of severe COVID-19 are associated with chronic airway neutrophilia. Furthermore, examination of COVID-19 explanted lung tissue revealed a series of epithelial pathologies associated with the infiltration and activation of neutrophils, indicating neutrophil activity in response to SARS- CoV-2 infection. To determine the impact of neutrophil-epithelial interactions on the infectivity and inflammatory responses to SARS-CoV-2 infection, we developed a co-culture model of airway neutrophilia. SARS-CoV-2 infection of the airway epithelium alone does not result in a notable pro-inflammatory response from the epithelium. The addition of neutrophils induces the release of proinflammatory cytokines and stimulates a significantly augmented pro-inflammatory response subsequent SARS-CoV-2 infection. The resulting inflammatory response is polarized with differential release from the apical and basolateral side of the epithelium. Additionally, the integrity of the epithelial barrier is impaired with notable epithelial damage and infection of basal stem cells. This study reveals a key role for neutrophil-epithelial interactions in determining inflammation and infectivity in response to SARS-CoV-2 infection.

30 Novel Technique of Gastrojejunostomy Tube Insertion to Control Retracted Proximal Stoma

Introduction

Extensive small bowel resection for ischaemia can require formation of a proximal jejunostomy. Depending on length of remaining jejunum, a major potential complication is stoma retraction with resultant peritonitis, intra-abdominal sepsis and enterocutaneous fistula formation.

We describe a case using a novel technique of inserting a retrograde gastrojejunostomy tube to gain control of an acutely retracted stoma in a 61-year-old patient who developed an enterocutaneous fistula shortly after major resection due to ischaemia.

Method

Under fluoroscopic guidance, the retracted proximal limb of the jejunostomy was cannulated antegradely by guide wire. A gastro-jejunostomy tube was inserted retrograde over the guide wire and the tip placed within the stomach. The proximal tube fenestrations were sited within the duodenum and the balloon was inflated to limit enteric content spilling into the peritoneal cavity.

Conclusions

This technique enabled drainage of gastroduodenal fluid, minimised spillage into the peritoneal cavity, reduced fistula output and controlled sepsis. This allowed time for nutritional optimisation, better glycaemic control, and endovascular revascularisation in preparation for restoration of intestinal continuity at an appropriate time.

This method offered a useful alternative to surgery, in a patient for whom emergency re-exploration of the abdomen would carry significant risk of morbidity or mortality.

Diffuse Alveolar Hemorrhage and Pulmonary Vasculitides: Histopathologic Findings

Vasculitides are a heterogeneous group of disorders in which inflammation of blood vessel walls is present at least some time during the course of the disease. Vasculitides can affect any caliber or type of vessel in many anatomic sites; however, the disease can alter more than just vasculature. Given the diversity of vasculitides, in 2012, a revised classification system was proposed to categorize vasculitides by the type of vessel involved including size, function, and structural attributes. In the lung, vasculitis impacts both the pulmonary vessels and parenchyma. Extrapulmonary involvement, particularly with concomitant kidney involvement, is a frequent occurrence. Pulmonary vasculitides often present with hemoptysis, pathologically manifested as diffuse alveolar hemorrhage (DAH) with or without capillaritis and can be life threatening when diffuse throughout the lungs. Etiologies for DAH include both primary and secondary vasculitides, along with collagen-vascular diseases, infection, and drug toxicity. Therefore, diagnosing the specific vasculitic etiology often relies on comprehensive assessment of all clinical, laboratory/serological, imaging, and histopathologic features that may be present. The most common primary pulmonary vasculitides often affect small vessels and are associated with circulating antineutrophilic cytoplasmic antibodies (ANCAs). In the 2012 classification, these include granulomatosis with polyangiitis (formerly Wegener granulomatosis), eosinophilic granulomatosis with polyangiitis (formerly Churg–Strauss' syndrome), and microscopic polyangiitis. Other less frequent vasculitides that are non-ANCA associated or affect medium- to large-sized vessels can have pulmonary involvement. These entities are usually associated with extrapulmonary disease and include polyarteritis nodosa, Takayasu's arteritis, Behçet's disease, and antibasement membrane antibody disease (formerly Goodpasture's syndrome). Although all vasculitides have vessel wall inflammation at some phase in the disease process, their histopathologic findings are as diverse as the group of diseases themselves. The characteristic histologic findings of the pulmonary vasculitides will be reviewed here.

Chronic Lung Allograft Dysfunction: Evolving Concepts and Therapies

Lung transplantation has become an established therapeutic option for a variety of end-stage lung diseases. Technical advances in graft procurement, implantation, perioperative care, immunosuppression, and posttransplant medical management have led to significant improvements in 1-year survival, but outcomes after the first year have improved minimally over the last two decades. The main limitation to better long-term survival after lung transplantation is chronic lung allograft dysfunction (CLAD). CLAD also impairs quality of life and increases the costs of medical care. Our understanding of CLAD manifestations, risk factors, and mechanisms is rapidly evolving. Recognition of different CLAD phenotypes (e.g., bronchiolitis obliterans syndrome and restrictive allograft syndrome) and the unique pathogenic mechanisms will be important for developing novel therapies. In addition to alloimmune-mediated rejection, we now recognize the importance of alloimmune-independent mechanisms of injury to the allograft. CLAD is the consequence of dysregulated repair of allograft injury. Unfortunately, currently available therapies for CLAD are usually not effective. However, the advances in knowledge, reviewed in this manuscript, should lead to novel strategies for CLAD prevention and treatment, as well as improvement in long-term outcomes after lung transplantation. We provide an overview of the evolving terminology related to CLAD, its varying clinical phenotypes and their diagnosis, natural history, pathogenesis, and potential treatments.

Giant cell aortitis leading to Stanford type B and type A aortic dissection

This report provides a rare histological example and the appropriate management of spontaneous aortic dissection secondary to giant cell arteritis.

European Society of Coloproctology consensus on the surgical management of intestinal failure in adults

Intestinal failure (IF) is a debilitating condition of inadequate nutrition due to an anatomical and/or physiological deficit of the intestine. Surgical management of patients with acute and chronic IF requires expertise to deal with technical challenges and make correct decisions. Dedicated IF units have expertise in patient selection, operative risk assessment and multidisciplinary support such as nutritional input and interventional radiology, which dramatically improve the morbidity and mortality of this complex condition and can beneficially affect the continuing dependence on parenteral nutritional support. Currently there is little guidance to bridge the gap between general surgeons and specialist IF surgeons. Fifteen European experts took part in a consensus process to develop guidance to support surgeons in the management of patients with IF. Based on a systematic literature review, statements were prepared for a modified Delphi process. The evidence for each statement was graded using Oxford Centre for Evidence-Based Medicine Levels of Evidence. The current paper contains the statements reflecting the position and practice of leading European experts in IF encompassing the general definition of IF surgery and organization of an IF unit, strategies to prevent IF, management of acute IF, management of wound, fistula and stoma, rehabilitation, intestinal and abdominal reconstruction, criteria for referral to a specialist unit and intestinal transplantation.

Banff 2013 meeting report: inclusion of c4d-negative antibody-mediated rejection and antibody-associated arterial lesions

The 12th Banff Conference on Allograft Pathology was held in Comandatuba, Brazil, from August 19-23, 2013, and was preceded by a 2-day Latin American Symposium on Transplant Immunobiology and Immunopathology. The meeting was highlighted by the presentation of the findings of several working groups formed at the 2009 and 2011 Banff meetings to: (1) establish consensus criteria for diagnosing antibody-mediated rejection (ABMR) in the presence and absence of detectable C4d deposition; (2) develop consensus definitions and thresholds for glomerulitis (g score) and chronic glomerulopathy (cg score), associated with improved inter-observer agreement and correlation with clinical, molecular and serological data; (3) determine whether isolated lesions of intimal arteritis ("isolated v") represent acute rejection similar to intimal arteritis in the presence of tubulointerstitial inflammation; (4) compare different methodologies for evaluating interstitial fibrosis and for performing/evaluating implantation biopsies of renal allografts with regard to reproducibility and prediction of subsequent graft function; and (5) define clinically and prognostically significant morphologic criteria for subclassifying polyoma virus nephropathy. The key outcome of the 2013 conference is defining criteria for diagnosis of C4d-negative ABMR and respective modification of the Banff classification. In addition, three new Banff Working Groups were initiated.

Splenic laceration with a twist: a lesson learnt from gastric volvulus

Acute gastric volvulus is an uncommon entity that requires prompt diagnosis and management to prevent potential life threatening complications. We present a rare case of splenic laceration secondary to acute gastric volvulus.

Death from metastatic donor-derived ovarian cancer in a male kidney transplant recipient

Posttransplant malignancy developing in an allograft is an uncommon complication of organ transplantation. The tumor may represent malignant transformation of donor or recipient cells that were previously normal, metastatic malignancy of recipient origin or malignancy transmitted from organ donor to recipient. Establishing the origin of the malignancy is critical to treatment algorithms. It is generally believed allograft removal and immunosuppression withdrawal will lead to resolution of transmitted malignancies in cases where the renal allograft is the origin. We report a male patient who developed metastatic ovarian malignancy secondary to donor transmission.

Phosphorylated S6 ribosomal protein: a novel biomarker of antibody-mediated rejection in heart allografts

We tested the hypothesis that phosphorylation of S6 ribosomal protein (S6RP), a downstream target of the PI3K/Akt/mTOR pathway, is a biomarker of antibody-mediated rejection (AMR) in heart allografts. Primary cultures of human aortic and microvascular endothelial cells (EC) were treated with anti-HLA class I and class II antibodies (Ab) and cell lysates were studied for phosphorylation of S6 ribosmal protein at Serine235/236 (p-S6RP). Treatment of cultured EC with anti-class I and class II Ab stimulated S6RP phosphorylation. Immunohistochemical techniques were used to detect the level of p-S6RP in endomyocardial biopsies (n = 131) from 46 heart transplant recipients and the results were correlated with histopathological diagnosis of rejection, C4d staining, production of posttransplant anti-HLA Ab and clinical outcome. Increased phosphorylation of S6RP in endomyocardial biopsies was significantly associated with the diagnosis of AMR (p < 0.0001). No significant association between acute cellular rejection (ACR) and p-S6RP was observed. C4d staining was positively associated with both AMR and p-S6RP. Posttransplant anti-HLA class II Ab production was also significantly associated with a positive p-S6RP status in cardiac biopsies. These results indicate that p-S6RP is a useful biomarker for the diagnosis of AMR.

Efficacy of botulinum toxin in chronic anal fissure

BACKGROUND

Chronic anal fissures (CAF) are caused by anal sphincter hypertonia leading to an ischaemic ulcer. By inducing temporary sphincter relaxation, botulinum toxin (Botox) injection has been shown to heal CAF in approximately 73-96% of cases in clinical trials.

AIM

This study looks at the efficacy of Botox clinical practice.

METHODS

The medical charts were reviewed of all patients with CAF treated with Botox (30iu injected into the sphincter complex in three 10iu aliquots) in the Ulster Hospital, Dundonald, Northern Ireland between March 1999 and November 2001.

RESULTS

Fifty-one charts were identified. Four patients failed to attend for review and were excluded from the study. Of the remaining 47 patients, 37 (78.7%) were healed following Botox injection. 10 out of 37 (27.0%) developed a recurrent CAF after a median time of 16.0 months (IQR 3.8-20 months). Eight of these patients opted for repeat Botox injection, which was successful in 7 (87.5%) cases. No adverse effects were reported.

CONCLUSION

Botox injection for the treatment of CAF is as effective in clinical practice as reported in clinical trials from specialist centres.

Risk of silicosis in cohorts of Chinese tin and tungsten miners and pottery workers (II): Workplace-specific silica particle surface composition

BACKGROUND

It is hypothesized that surface occlusion by alumino-silicate affects the toxic activity of silica particles in respirable dust. In conjunction with an epidemiological investigation of silicosis disease risk in Chinese tin and tungsten mine and pottery workplaces, we analyzed respirable silica dusts using a multiple-voltage scanning electron microscopy-energy dispersive X-ray spectroscopy (MVSEM-EDS).

METHODS

Forty-seven samples of respirable sized dust were collected on filters from 13 worksites and were analyzed by MVSEM-EDS using high (20 keV) and low (5 keV) electron beam accelerating voltages. Changes in the silicon-to-aluminum X-ray line intensity ratio between the two voltages are compared particle-by-particle with the 90th percentile value of the same measurements for a ground glass homogeneous control sample. This provides an index that distinguishes a silica particle that is homogeneously aluminum-contaminated from a clay-coated silica particle.

RESULTS

The average sample percentages of respirable-sized silica particles alumino-silicate occlusion were: 45% for potteries, 18% for tin mines, and 13% for tungsten mines. The difference between the pottery and the metal mine worksites accounted for one third of an overall chi-square statistic for differences in change in measured silicon fraction between the samples.

CONCLUSION

The companion epidemiological study found lower silicosis risk per unit cumulative respirable silica dust exposure for pottery workers compared to metal miners. Using these surface analysis results resolves differences in risk when exposure is normalized to cumulative respirable surface-available silica dust.

Bleeding gastric varices--a rare complication of ovarian cancer

Splenic venous hypertension (or 'left-sided portal hypertension') is a rare underlying cause of gastro-oesophageal varices. Ovarian carcinoma recurring beyond 10 years, following primary treatment with no interval disease, is also a rare occurrence. We report an unusual case of bleeding gastric varices secondary to splenic venous obstruction as a result of metastatic ovarian carcinoma. This occurred 21 years following surgery and adjuvant chemotherapy for primary ovarian carcinoma. To our knowledge, until now, there have been no reported cases of splenic venous hypertension due to ovarian carcinoma. This case report illustrates the successful emergency management of this condition by splenectomy, with complete resolution of varices confirmed endoscopically at 6 weeks. It is followed by a brief discussion regarding varices due to splenic venous hypertension.

Comparison of inhibitory effects of oxygen radicals and calf serum protein on surfactant activity

The effects of the reactive oxygen species (ROS) superoxide anion (O2*-) and hydroxyl radical (*OH) on the surface tension lowering properties of bovine lipid extract surfactant (BLES) were compared to the effects of calf serum protein (CSP) in a captive bubble surfactometer (CBS). O2*- was generated from xanthine/xanthine oxidase (X/XO), and *OH was generated by the Fenton reaction. ROS were demonstrated by electron spin resonance (ESR) using 5,5-dimethyl-1-pyrroline-N-oxide (DMPO) as the spin trap. Lipid peroxidation was measured using the thiobarbituric acid method. *OH had broad inhibitory effects on surface tension parameters, including adsorption, minimum surface tension, percentage film area change and film compressibility. O2*- showed inhibitory effects on adsorption, film area change and film compressibility but had no significant effect on minimum surface tension. Both O2*- and *OH treatment were associated with a large 'squeezeout' plateau around 20-25 mN/m in the surface tension-area relation, indicating poor film organization during the compression phase. At the concentrations used, ROS were associated with lipid peroxidation of BLES, which also demonstrated radical scavenging properties. Calf serum protein produced inhibitory effects on adsorption, minimum surface tension and percentage film area change that were quantitatively similar to those produced by *OH. The effects on film compression were significantly greater and qualitatively different from those seen with either O2*- or *OH. We conclude that the inhibition of BLES surface activity by ROS and inhibitory proteins can be distinguished in the captive bubble surfactometer and, particularly, by changes in the film compressibility modulus.

A workingperson's guide to deconvolution in light microscopy

Thefluorescence microscope is routinely used to study cellular structure in many biomedical research laboratories and is increasingly used as a quantitative assay system for cellular dynamics. One of the major causes of image degradation in the fluorescence microscope is blurring. Deconvolution algorithms use a model of the microscope imaging process to either subtract or reassign out-of-focus blur. A variety of algorithms are now commercially available, each with its own characteristic advantages and disadvantages. In this article, we review the imaging process in the fluorescence microscope and then discuss how the various deconvolution methods work. Finally, we provide a summary of practical tips for using deconvolution and discuss imaging artifacts and how to minimize them.

The effect of tubing length, gas flow, and number of heaters on maximum gas temperature for aerosol circuits used for cold water near-drowning or hypothermia

BACKGROUND

Clinicians who treat patients suffering from cold water near-drowning or hypothermia routinely warm inspire gases greater than body temperature in accordance with care guidelines promulgated by the various organizations. However, humidifiers are designed to prevent heating gases beyond 41 C (assuming the use of a standard six foot aerosol circuit) in order to meet International Standards Organization regulations (ISO). Clinicians must modify equipment in order to deliver care. There are several factors, which can effect the highest temperature that a particular circuit will achieve. Among the factors that are considered most important for maximum circuit are tubing length, gas flow, and the number of heaters (heat source).

METHODS

The maximum temperature that a circuit could achieve was measured after varying tubing lengths (1.5 feet, 3 feet, and 6 feet), gas flow (opening or closing a venturi receiving a fixed flow rate of 10 L/min), and the size of the heat source (one or two heated humidifiers in aerosol circuit). A total of ten runs were made in each of the possible twelve combinations.

RESULTS

Univariate statistics showed significant differences for Venturi open/close (p = .0001) and the number of heaters (p = .0001) but not the tubing length (p = 0.19). However, the multivariate analysis revealed significance for tubing length, number of heaters, and venturi open/closed (p = .01).

CONCLUSION

All factors (tubing length, number of heaters, and tubing length) were important determinants of maximum gas temperature. The effect of tubing length can be overwhelmed by higher gas flows.

The effects of medical group practice organizational factors on physicians' use of resources

Few studies have systematically examined the influence of physician, patient, and practice characteristics on physician-directed use of resources within the overall environment of medical group practices and none have included the practice culture in the analysis. This study analyzes the effects of the structure and culture of medical group practices on the amount of resources used to manage uncomplicated hypertension episodes of care for enrollees in a Minneapolis/St. Paul HMO during 1990. Three findings emerged from this study: (1) resource use for a well-defined episode of care varies much more than one would expect in this highly competitive managed care environment; (2) the culture of the group practice appears to be more important than organizational structure in determining resource use for the treatment of hypertension; and (3) together the culture and structural variables only explain 8 percent of the variance in resource use. The study indicated that medical group practice organizations have less influence on physicians' practice styles than expected. The group practices studied are all located in a highly competitive managed care environment and these conditions should be causing them to create more standardized practice styles among their physicians. However, wide variations in individual physician practice styles account for most of the differences observed. Either much of the unexplained variance in resource use for this episode of care results from unobserved patient and illness characteristics, or managed healthcare is not yet causing medical group practices in Minnesota to challenge physicians' individualistic practice styles.

Death of PC12 cells and hippocampal neurons induced by adenoviral-mediated FAD human amyloid precursor protein gene expression

We used adenoviral-mediated gene transfer of human amyloid precursor proteins (h-APPs) to evaluate the role of various h-APPs in causing neuronal cell death. We were able to infect PC12 cells with very high efficiency because approximately 90% of the cells were cytochemically positive for beta-galactosidase activity when an adenoviral vector containing LacZ cDNA was used to infect cells. Cells infected with adenovirus containing h-APP cDNA showed high-level transcription and expression of h-APP as measured by reverse transcriptase-polymerase chain reaction and Western immunoblot analyses, respectively. Intracellular and extracellular levels of h-APP were elevated approximately 17-and 24-fold in cultures infected with recombinant adenovirus containing wild-type mutant and 13- and 17-fold with V642F mutant. No elevation in h-APP was seen in cultures infected with antisense h-APP or null adenovirus. H-APP levels were maximal 3 days after infection. Overexpression of V642F mutant h-APP in PC12 cells and hippocampal neurons resulted in about a twofold increase in death compared with overexpression of wild-type h-APP. These results demonstrate the usefulness of recombinant adenoviral mediated gene transfer in cell culture studies and suggest that overexpression of a familial Alzheimer's disease mutant APP may be toxic to neuronal cells.

Beta-amyloid augments platelet aggregation: reduced activity of familial angiopathy-associated mutants

The beta-amyloid (A beta) peptide is present both in serum and in platelets, however it is unclear whether A beta plays a role in platelet function. We have now investigated the effects of soluble A beta on platelet function and have found that low levels (0.1-1 nM) of soluble A beta augment ADP-dependent platelet aggregation and translocation of focal adhesion kinase to the platelet cytoskeleton. Addition of A beta to gel-filtered platelets along with concentrations of adenosine diphosphate (ADP) producing submaximal aggregation responses increased the aggregation response by over 2-fold depending on the ADP:A beta ratios. The structure activity requirements for A beta activity showed intriguing constraints. Only full length A beta has significant activity. Truncated A beta peptides, such as A beta(1-16) or A beta(25-35), or reverse A beta(40-1) all show little or no activity. We also examined the activity of mutant A beta peptides, corresponding with the APP(692A-G) and APP(693E-Q) (at A beta21 and A beta22, respectively) which are found in familial Alzheimer's disease and hereditary cerebral hemorrhagic amyloidosis, Dutch type (HCHWA-D), and found that these peptides showed little or no activity. These results suggest that A beta interacts with platelets in a highly specific manner and may play a role in regulating platelet function.

Evaluation of a bicycle skills training program for young children: a randomized controlled trial

OBJECTIVE

To evaluate the effectiveness of a skills training program in improving safe cycling behavior, knowledge, and attitudes in young children.

METHODS

Grade 4 children from six elementary schools in East York (a borough of Metropolitan Toronto) participated. The intervention--playground based instruction on bicycle handling skills by certified instructors--was randomly allocated to three schools. Altogether 141 children participated: 73 in the intervention group and 68 in the control group, with follow up evaluations available on 117 (83%). The primary outcome was safe cycling behavior (straight line riding, coming to a complete stop, and shoulder checking before a left turn). A self report questionnaire collected data on knowledge and attitudes. Baseline assessments were made in June, with follow up evaluations in September, 1995.

RESULTS

The prevalence of safe cycling behaviors at follow up in the intervention and control groups respectively, were: straight line riding (90% v 88%; p = 0.782), coming to a complete stop (90% v 76%; p = 0.225), and shoulder checking (0% v 2%; p = 1.000). Over time (from baseline to follow up) children in both groups were more likely to maintain straight line riding, less likely to ride on the sidewalk, and less likely to consider that a car had more right to the road.

CONCLUSIONS

This brief skills training program was not effective in improving safe cycling behavior, knowledge, or attitudes among grade 4 children.

The use of exhaled carbon monoxide for the diagnosis of carbon monoxide poisoning. A case report

INTRODUCTION

Carbon monoxide (CO) poisoning is difficult to confirm in small rural hospitals that lack easy access to a cooximeter. A small hand held device can be used to assess exhaled CO (ECO) in parts per million. This device is often used in smoking cessation clinics to confirm that a person has abstained from smoking.

CASE SUMMARY

A 47-year-old white male became dizzy and had a near syncopal episode while working on his boat in the local marina. He was brought to the ER and was found to have an exhaled CO level of 180 ppm. The presence carboxyhemoglobin (HbCO) was confirmed later by an independent reference laboratory and the result was 26% HbCO.

DISCUSSION

The patient's exhaled CO level dropped slower than expected while breathing oxygen delivered by a non-rebreather mask. This could be due to inadequate compliance to oxygen therapy and a fiO2 somewhat less than 1.0. Another limitation of the technique is the calibration gas (50-ppm CO). This concentration may be too low to assess ER patients. Therefore a confirmatory ABG with cooximetry should be obtained if available. Clinicians are cautioned that there is no safe level of HbCO (6). There is a simple formula to convert ECO to HbCO. The use of exhaled CO monitoring may be a promising alternative that is relatively less expensive than cooximetry in the ER setting, but more research is clearly indicated.

Does it make sense to heat gases higher than body temperature for the treatment of cold water near-drowning or hypothermia? A point of view paper

There appears to be several areas of concern relating to the continued use of heating gases higher than body temperature for the treatment of cold water near-drowning. The use of heated gases as a primary means to rewarm a hypothermic patient does not seem to be any more effective than doing nothing at all. These low rewarming rates translate into some very long resuscitations. Even Dr. Nemiroff, who was a strong advocate of using heated humidified gases for treating cold water near-drowning, did not consider the use of warm inspired gases to be a primary rewarming technique. He referred to the use of heated humidified gases as a, "stabilization technique". However, does it make sense to use a technique that is several times slower than other methods of similar complexity? Does it make sense to use a protocol that may in fact lower a hypothermic patient's basal metabolic rate? There are some major patient safety issues raised by heating gases to high levels. However, there have not been many patients with documented airway damage. I have several hypothesis about why this is so. Few people seem to know how to significantly heat their patient's circuit. If they devise a system that gets to the therapeutic range they usually have second thoughts when the bag-valve-mask is too hot to hold, or the plastic wide bore tubing begins to melt, they will reduce the system temperature on that basis alone. Many of the hypothermic patients who are intubated simply do not have good survival rates, and so we may underestimate the degree of airway damage that occurs. Spontaneously breathing patients will tend to refuse to breathe hot gases which limits their potential for airway damage. However, is this a risk we need to run? Would it not make more sense to heat the inspired gases to close to body temperature and avoid the problem? I feel that the time has come for the Respiratory Therapy community to come together and work on this problem. The researchers have done their jobs in providing us with reasonable data on which to base a clinical decision. It would seem to me that if a Clinical Practice Guideline for cold water near-drowning or hypothermia were in place it might provide the other groups impetus for updating their guidelines. The bottom line is that patients deserve the best care that we know how to provide, and a clear set of guidelines is an essential first step.

An unusual case of laryngeal pseudotumour

A pseudotumour represents a lesion that masquerades as a malignant neoplasm. We present an unusual case where the appearance of a tumour was the result of chronic inflammation stimulated by the presence of food matter. This inflammatory reaction resulted in upper airway obstruction associated with a mass lesion and vocal fold palsy.

A comparison of multiplex and simplex families with Alzheimer's disease/senile dementia of Alzheimer type within a well defined population

A study was made on 150 clinically demented patients presenting at autopsy at Umeå University Hospital in Sweden. In 90 of the cases dementia was considered to be primary in nature and of these forty six per cent (41 cases), fulfilled both the clinical and histopathological criteria for the diagnosis of Alzheimer's disease/Senile dementia of Alzheimer type (AD/SDAT). The families of these 41 AD/SDAT cases were then studied, and a family history obtained through interviews with multiple family informants and from civil and medical records. Additional diseased family members suffering from progressive dementia (multiplex families) were observed in 12 probands out of 41 (29%). Multiplex families exhibited similar clinical and histopathological characteristics as simplex families containing a single affected individual. The secondary cases in the multiplex families exhibited similar demographic and clinical characteristics as the probands. 39% of the multiplex and 14% of the simplex cases had an early age of onset of the disease, that was under 65 years. The overall prevalence of progressive dementia disorders in the 41 families was 5.9%. The prevalence of a progressive dementia disorder was 11% in the multiplex families (14% for the early onset cases) and 3.5% in the simplex families (2% for the early onset cases). The prevalence of progressive dementia disorder for family members who had passed the mean age of the onset of the disease for their family, was 45% for multiplex and 18% for simplex families. Furthermore the incidence rate for dementia was significantly higher (p < 0.005) in multiplex families (5.5 per 1,000 person years) when compared to simplex families (2.5 per 1,000 person years). No differences could be seen in parental age at birth of the diseased when comparing the two sets of families. However in multiplex families the duration of the disease was significantly (p < 0.025) shorter, in subjects with parental age at birth over 35 years compared to those with a parental age under 35 years. The multiplex families contained significantly (p < 0.025) larger sibships; and showed a significantly lower age of onset for the disease (p < 0.001), and a significantly longer duration of disease (p < 0.05) compared to the simplex families. A significant intra familial correlation of age at disease onset was observed in both sets of the families.

Using the subcortically lesioned rat cortex to understand the physiological role of amyloid precursor protein

Alzheimer's disease pathology is characterized by the presence of neuritic plaques and neurofibrillary tangles and specific neurotransmitter deficits in the cortex and hippocampus. Advances in the understanding of Alzheimer's disease have been hampered by the absence of appropriate animal model systems. Most in vivo rodent models have turned to aged animals, animals with experimentally induced lesions of various neurotransmitter systems, animals with pharmacologically induced neurotransmitter perturbations, and mice made transgenic for genes related to amyloid precursor protein. These models have been useful for the investigation of some discrete aspects of Alzheimer's disease, including deficits in forebrain cholinergic activity and the resulting cognitive deficits. However, none of these models have led to the development of the principal neuropathological hallmarks of Alzheimer's disease, neuritic plaques and neurofibrillary tangles. Furthermore, the relationship, if any, between the reduction of neurotransmitter activity and the formation of neuritic plaques and neurofibrillary tangles is unknown. The subcortically lesioned rat model system which we have used approximates the cortical neurotransmitter and the cognitive deficits of Alzheimer's disease. We have recently found that these same subcortical neurotransmitter system lesions alter the expression of amyloid precursor protein, the precursor of beta amyloid peptide, which is the principal component of neuritic plaques. Loss of functional subcortical innervation by either permanent lesions or transient inhibition of cortical neurotransmitter (acetylcholine) release resulted in the induction of amyloid precursor protein in the cortex. The induction was rapid and persistent with the permanent lesions or reversible with the transient inhibition. Lesions cholinergic, serotonergic,and adrenergic neurotransmitter systems all resulted in the induction.(ABSTRACT TRUNCATED AT 250 WORDS)

The relationship between self-esteem and depression in obese children

It has been suggested that obese children have increased problems with self-esteem and depression when compared to the normal pediatric population. Fifty-one consecutive patients enrolled in a hospital based weight management program received the CDI and the PHSCS as part of their initial evaluation. There were 24 males and 27 females with ages ranging from 5-17 years and BMI (kg/m2) of 22-63 (mean 33.3). Results of the CDI were classified into three groups. Children with CDI scores greater than 13 were classified as depressed (n = 16). Scores between 9 and 12 were considered borderline depression (n = 11). Scores less than 9 were considered normal (n = 24). The children in the depressed and borderline groups were significantly different from the children in the normal group in their level of self-esteem. As depression increased, self-esteem decreased, indicating an inverse relationship between self-esteem and depression. Depressed and borderline depressed children were also more anxious (i.e., nervous, worried) and had more perceived behavior problems (increased frequency of punishment, difficulty obeying orders) than the normal group. They also had fewer interests in school and felt their physical appearance was not acceptable. The depressed group's scores were significantly lower on the happiness and popularity scales of the PHSCS than the normal group. Scores on the CDI did not correlate with age, race, sex, Tanner stage, socioeconomic status, or body mass index. In this study obese pediatric patients showed significant depression and lowered self-esteem.(ABSTRACT TRUNCATED AT 250 WORDS)