Metals and Organohalogen Contaminants in Bald Eagles (Haliaeetus leucocephalus) from Ontario, 1991-2008.

We examined the degree of exposure of lead (Pb), mercury (Hg), and several organohalogen contaminants and its potential impact on survival of bald eagles in Ontario from 1991 to 2008. Overall, results for 43 dead or dying bald eagles collected in the province indicate that 23% (10/43) of birds died of Pb poisoning and 9% (4/43) died of suspected Hg poisoning. Pb poisoning was diagnosed based on exceedances of toxicity thresholds in liver and kidney and supported by clinical observations, necropsy results, and histology findings when available. Evidence for Hg poisoning in eagles was limited; however, Hg concentrations exceeded the toxicity threshold in kidney. Pb concentrations ranged widely in liver and kidney. Total Hg concentrations were relatively higher in kidney compared with liver and were significantly correlated with selenium (Se) concentrations in both tissues. Concentrations of p,p'-DDE and sum PCBs in livers of 12 bald eagles collected from 2001 to 2004 were likely below concentrations associated with adverse effects. Hepatic concentrations of total polybrominated diphenyl ethers were generally higher in birds collected from southern Ontario compared with northern Ontario. Potential impacts of exposure to these flame retardants and others are not known. Elevated metal exposure appears to influence survivorship and may affect the recovery of bald eagles in the province, particularly in southern Ontario and along the Great Lakes where a disproportionate number of poisoned eagles were collected. Increased efforts are needed to identify sources of exposure and develop measures to reduce metal exposure in this top predator.

All-D peptides recognized by an anti-carbohydrate antibody identified from a positional scanning library.

Monoclonal antibodies recognize antigens with high affinity and specificity, but the structural basis for molecular mimicry remains unclear. It is often assumed that cross-reactive antigens share some structural similarity that is specifically recognized by a monoclonal antibody. Recent studies using combinatorial libraries, which are composed of millions of sequences, have examined antibody cross-reactivity in a manner entirely different from traditional epitope mapping approaches. Here, peptide libraries were screened against an anti-carbohydrate monoclonal antibody for the identification of peptide mimics. Positional scanning libraries composed of all-l or all-d hexapeptides were screened for inhibition of monoclonal antibody HGAC 39.G3 binding to an antigen displaying N-acetyl-d-glucosamine (GlcNAc) residues on a polyrhamnose backbone. Inhibitory activity by mixtures from the all-d hexapeptide library was greater than the activity from the all-l libraries. The most active d-amino acid residues defined in each of the six positions of the library were selected to prepare 27 different individual hexapeptides. The sequence Ac-yryygl-NH2 was specifically recognized by mAb HGAC 39.G3 with a relative affinity of 300 nM when measured in a competitive binding assay. The contributions to overall specificity of the residues of the all-d peptide (Ac-yryygl-NH2) in binding to mAb HGAC 39.G3 were examined with a series of truncation, l and d-amino acid substitution, and retro analogs. Dimeric forms of the all-d peptide were recognized with tenfold to 100-fold greater affinities relative to the monomer. The all-d peptide was found to inhibit mAb HGAC 39.G3 binding to an anti-idiotype antibody with approximately 1000-fold greater affinity than GlcNAc. As demonstrated here, the study of immune recognition using combinatorial chemistry may offer new insights into the molecular basis of cross-reactivity.

Transfer factor therapy for histoplasmosis in a patient with Hodgkin's disease.

A patient with recurrent chronic histoplasmosis was diagnosed also as having Hodgkin's disease. Studies of cell-mediated immunity (CMI) demonstrated no reaction to histoplasmin by skin test, lymphocyte transformation (LT), or leukocyte inhibition factor (LIF) assay. Clinical and immunologic studies were performed during treatment with 19 doses of dialyzable transfer factor (TF) prepared from a normal donor with strong CMI against histoplasmin. Transfer of CMI to the patient was demonstrated by all three tests. All tests reverted to nonreactive during the period of observation. Repeated doses of dialyzable TF were followed by reconversion of skin tests. The LIF assay was most reactive. Reactivation of histoplasmosis occurred during antimetabolic therapy for Hodgkin's disease; however, the lesions cleared rapidly when TF was added to amphotericin B. Amphotericin B was administered at a dosage of 25 mg three times each week during the entire study.

Miconazole therapy for fungal meningitis.

Eight patients with fungal meningitis (5 with the coccidioidal type, 2 with cryptococcal, and 1 with histoplasmosis) were treated with intravenous (IV) and intrathecal (IT) miconazole after previous therapy with amphotericin B proved unsuccessful. Miconazole was well tolerated with both IV and IT administration. The CSF concentration of miconazole one hour after an IV infusion of 800 mg was 0.1 to 0.3 microgram/ml. When 20 mg of miconazole was administered intrathecally via lumbar injection in patients with coccidioidal meningitis, 6.5, 2.4, 0.77, and 0.24 microgram/ml, respectively, was found in the CSF at the cisternal level at 12, 24, 48, and 72 hours, respectively. Miconazole is apparently an effective fungistatic drug of low toxicity and is a potentially useful agent in the treatment of systemic mycoses and fungal meningitis, in particular.

Re-establishment of neurochemical coding of preganglionic neurons innervating transplanted targets.

We investigated the effect on neurochemical phenotype of changing the targets innervated by sympathetic preganglionic neurons. In neonatal rats, the adrenal gland was transplanted into the neck, to replace the postganglionic neurons of the superior cervical ganglion. Transplanted adrenal glands survived, and contained noradrenergic and adrenergic chromaffin cells, and adrenal ganglion cells. Retrograde tracing from the transplants showed that they were innervated by preganglionic neurons that would normally have supplied postganglionic neurons of the superior cervical ganglion. The neurochemical phenotypes of preganglionic axons innervating transplanted chromaffin cells were compared with those innervating the normal adrenal medulla or superior cervical ganglion neurons. As in the normal adrenal gland, preganglionic nerve fibres apposing transplanted chromaffin cells were cholinergic. The peptide and calcium-binding protein content of preganglionic fibres was similar in normal and transplanted adrenal glands. In both cases, cholinergic fibres immunoreactive for enkephalin targeted adrenergic chromaffin cells, whilst cholinergic fibres with co-localised calretinin-immunoreactivity innervated noradrenergic chromaffin cells and adrenal ganglion cells. In contrast to the innervation of normal adrenal glands, these axons lacked immunoreactivity to nitric oxide synthase. In a set of control experiments, the superior cervical ganglion was subjected to preganglionic denervation in rat pups the same age as those that received adrenal transplants, and the ganglion was allowed to be re-innervated over the same time course as the adrenal transplants were studied. When the superior cervical ganglion was re-innervated by preganglionic nerve fibres, we observed that all aspects of chemical coding were restored, including cholinergic markers, nitric oxide synthase, enkephalin, calcitonin gene-related peptide and calcium binding proteins in predicted combinations, although the density of nerve fibres was always lower in re-innervated ganglia. These data show that the neurochemical phenotypes expressed by preganglionic neurons re-innervating adrenal chromaffin cells are selective and similar to those seen in the normal adrenal gland. Two explanations are advanced: either that contact of preganglionic axons with novel target cells has induced a switch in their neurochemical phenotypes, or that there has been target-selective reinnervation by pre-existing fibres of appropriate phenotype. Regardless of which of these alternatives is correct, the restoration of normal preganglionic codes to the superior cervical ganglion following denervation supports the idea that the target tissue influences the neurochemistry of innervating preganglionic neurons.

Commentary on the 1993 American Thoracic Society guidelines for the treatment of community-acquired pneumonia.

Early treatment of community-acquired pneumonia (CAP) is associated with improved outcome. Since extensive diagnostic testing identifies an etiologic agent in only half of the cases and usually requires several hours or even days for results, CAP is most often initially treated empirically. In 1993, the American Thoracic Society (ATS) established guidelines to assist primary care physicians in antibiotic selection for the initial empiric treatment of CAP in immunocompetent adults. Since publication of the guidelines, the incidence of certain bacteria has been redefined, antimicrobial resistance patterns have changed, risk factors for stratifying need for hospitalization have been further defined, and newer antibiotics have been introduced. These changes necessitate a reevaluation of the 1993 ATS guidelines. This article proposes a modification of the ATS guidelines. This modification continues to classify patients into groups, based on specific risk factors, to which a limited number of likely pathogens are identified and for which antibiotic treatment regimens are developed. The modification differs from the original ATS guidelines because of the changes in risk factors. Patient groups are still broadly divided into outpatient and inpatient care, but earlier risk factors of age and coexisting illness have been refined. Risk factors suggested herein as considerations to guide treatment include the presence of cardiopulmonary disease, history of smoking, severity of illness, risk of drug-resistant Streptococcus pneumoniae and Pseudomonas aeruginosa, and need for ICU admission.

Acute miliary blastomycosis presenting as fluminating respiratory failure.

A patient with miliary blastomycosis had acute fulminating respiratory failure requiring prolonged external ventilatory support. Treatment consisted of antifungal chemotherapy with two drugs and administration of corticosteroids. Restrictive ventilatory impairment and exercise-induced hypoxemia persist at one year after completion of therapy.

Nosocomial pneumonia guidelines: an international perspective.

Hospital-acquired pneumonia is a serious illness with substantial morbidity and mortality. Management of this illness is challenging for the physician and a number of diverse issues must be considered when initiating therapy. Guidelines for the treatment of hospital-acquired pneumonia have been developed in Canada and the United States. A questionnaire sent to infectious disease physicians or clinical microbiologists in 29 countries showed that Australia, Sweden, and France had national guidelines in addition to Canada and the United States, while Hong Kong and France had single hospital-based guidelines. These guidelines are reviewed and some of the controversial issues relating to nosocomial pneumonia are discussed.

Pleural mesothelioma with calcified liver metastases.

This is the second published report of a patient with a malignant pleural mesothelioma who presented with roentgenographic findings of massive liver calcifications. Necropsy examination revealed the hepatic calcifications to be dystrophic calcification within necrotic foci of metastatic malignant mesothelioma.

Antinuclear antibodies in pleural fluid.

Systemic lupus erythematosus (SLE) frequently involves the pleura with resultant pleural effusion. Previous studies have reported that detection of antinuclear antibodies (ANA) in pleural fluid using animal tissue as substrate was a sensitive and specific method for distinguishing SLE pleural effusions from other etiologies. The HEp-2 ANA, which uses a human cell line as substrate, is now the preferred ANA test; however, to our knowledge, no studies on pleural fluid using this assay have been reported. To determine its sensitivity and specificity, when measured in pleural fluid, HEp-2 ANA levels were determined in pleural effusion samples associated with a variety of different etiologies, including SLE, malignancy, congestive heart failure, pneumonia, tuberculosis, and a miscellaneous group of diseases. Pleural fluid ANA results were positive in 14 of 82 samples. Six of the eight (75 percent) pleural fluid samples collected from patients with SLE were ANA positive, and all but one had high titers (> 1:160) with a homogenous staining pattern. The remaining two patients with SLE with negative pleural fluid ANA had recurrent pulmonary emboli and congestive heart failure, rather than lupus pleuritis. Eight of 74 patients (10.8 percent) without clinical evidence of SLE had a positive pleural fluid ANA, with the majority having a speckled pattern. High titers were noted in three. These results indicate that a negative or low titer ANA and a speckled staining pattern in pleural fluid from a patient suspected of lupus pleuritis suggest an alternative diagnosis. High pleural fluid titers (up to 1:640) were seen occasionally in patients with inflammatory pleural effusions in the absence of SLE.

Microbial etiology of acute pneumonia in hospitalized patients.

The purpose of this study was to determine the microbial etiology of pneumonia by using strict criteria among a group of hospitalized patients. Patients with acute community-acquired or hospital-acquired pneumonia were studied in a systematic and comprehensive manner for bacterial, viral, chlamydial, mycobacterial, and fungal pathogens. A total of 198 patients with 204 episodes of pneumonia were evaluated. Despite 100 percent follow-up of all surviving patients, a specific etiologic agent could be found in only 103 episodes. Among 154 episodes of community-acquired pneumonia, a diagnosis was made in 79; the most common pathogen was from the genus Legionella, followed by various Gram-negative enteric bacteria, Gram-positive cocci, influenza A virus, and Mycoplasma pneumoniae. The etiologic agent was found in 24 of the 50 patients with hospital-acquired pneumonia; no pathogen predominated. We conclude that even when elaborate diagnostic studies are done, including many invasive procedures, the etiology can be determined in only about half of the patients with acute pneumonia. The pathogens of pneumonia in this study are not markedly different between community-acquired and hospital-acquired infection.

Preservation of pulmonary function by an outer membrane protein F vaccine. A study in rats with chronic pulmonary infection caused by Pseudomonas aeruginosa.

This study investigated the ability of a protein F vaccine to reduce macroscopic evidence of lung damage and preserve pulmonary function in immunized animals in a rat model of chronic pulmonary infection caused by Pseudomonas aeruginosa. Other membrane protein F of P aeruginosa was purified by extraction from polyacrylamide gels of cell envelope proteins of the PAO1 immunotype 7 strain. Rats were immunized intramuscularly with either 25 micrograms of the purified protein F or bovine serum albumin on days 0 and 14 and then challenged on day 28 via intratracheal inoculation of agar beads containing cells of an immunotype 3 clinical isolate of P aeruginosa. Also, included was a noninfected control group which received only sterile agar beads. On day 35, the lungs were excised, pulmonary compliance measured, and the lungs examined macroscopically for the presence and severity of lesions. The protein F-immunized rats had a significant (p < 0.01) reduction in the number of severe pulmonary lesions as compared with bovine serum albumin-immunized rats. Lung compliance (CL) was significantly (p < 0.001) reduced in rats which were immunized with bovine serum albumin (n = 17, CL = 0.12 +/- 0.008), whereas CL of protein F-immunized rats (n = 12, CL = 0.17 +/- 0.006) was similar to that of noninfected control rats (n = 5, CL = 0.15 +/- 0.008). This study demonstrated that a protein F vaccine has the ability to decrease macroscopic lung lesions from infection and preserve pulmonary function in actively immunized rats upon subsequent challenge with P aeruginosa in this model of chronic lung infection.

Anion gap in turpentine-induced pleural effusions. Correlation with pH and protein level.

Since the pleural fluid proteins and lactate are unmeasured anions, the pleural fluid anion gap (Na+K-Cl-total CO2) should vary with the protein level and should be high in acidic effusions (which have high lactate levels). The anion gap is also convenient and inexpensive to measure, and less subject to artifact than the pH measurement. To test the hypothesis that the anion gap correlates with the pH, protein level, and other traditional pleural fluid measurements, we used a well-described model of turpentine-induced effusions in nine New Zealand white rabbits. Nonacidic exudative effusions were induced by an intrapleural injection of turpentine; acidic exudative effusions were induced by a second injection. Pleural fluid and blood were obtained just before (0 h) and 9, 24, 48, and 72 h after the second injection. We found the anion gap correlated with pH, the glucose, protein, and lactate dehydrogenase levels, pleural-fluid/plasma protein and lactate dehydrogenase ratios, and WBC count (all p < 0.001). The pH and protein ratio together accounted for 95% of all anion gap variation within individual subjects. We also found the influence of the PCO2 level on pH was not significant after taking into account the influence of the anion gap. These results suggest the anion gap may be useful in the clinical evaluation of pleural effusions and could potentially replace the pH measurement.

Hospital-acquired pneumonia: epidemiology, etiology, and treatment.

Despite improvements in diagnosis, treatment, and prevention, hospital-acquired pneumonia (HAP) remains the number one cause of nosocomial mortality. This article reviews the current knowledge regarding the incidence, epidemiology, and causes of HAP, with the appreciation that the available information is incomplete and that controversies are common, and thus the authors provide a rational approach to the initial management of HAP in immunocompetent adults. A discussion of therapy and what to do with patients who do not respond to the empiric therapy are included. The American Thoracic Society (ATS) statement on HAP has served as a foundation for this review but has been supplemented by newer literature that was not available when the ATS statement was developed.

Overview of community-acquired pneumonia. Prognosis and clinical features.

Despite the introduction of newer antibiotics, vaccinations, and better supportive care, CAP remains a common, frequently fatal disease. Age and coexisting illness influence which infectious agents are most likely to cause infection. Severity of illness and clinical features are influenced by various host factors and by the virulence of the infectious agent. Mortality and morbidity are reduced by the rapid institution of appropriate antimicrobial therapy. Because of the limitations of presently available diagnostic tests, many patients are begun on empiric regimens, and in up to half of these individuals, a cause is not identified. Although there are a number of potential pathogens, it is possible to identify likely pathogens based on easily identifiable clinical factors (age, presence of coexisting disease, severity of illness at presentation, and the need for hospitalization). Using this approach, CAP in immunocompetent adults may be divided into four categories. Once empiric therapy has been initiated, therapy should be continued for at least 72 hours unless clinical deterioration is noted. Within 4 days, fever and leukocytosis should return to baseline, but abnormal physical findings (i.e., crackles) require longer to resolve, especially with coexisting illness, and chest radiographic findings are the last to return to baseline and are especially delayed if the patient is bacteremic or has structural lung disease. Not all patients respond to initial empiric therapy. Reasons for this include antimicrobial resistance, the presence of nonbacterial pathogens (respiratory viruses), unusual bacterial pathogens, noninfectious causes that may mimic CAP, infectious complications (i.e., empyema), and pneumonia occurring in patients with unrecognized severe immunosuppression. Failure to improve after 72 hours and development of deterioration are indications for repeat diagnostic workup and consideration of alternative diagnoses. More invasive diagnostic tests are appropriate in severely ill patients and in those whose condition is deteriorating rapidly.

Therapy of nosocomial pneumonia.

HAP remains a major cause of morbidity and mortality among hospitalized patients. Although early appropriate therapy results in improved outcomes, the cause of HAP frequently is not known at the time antimicrobial therapy is initiated. Most cases of HAP result from microaspiration of oropharyngeal secretions previously colonized with pathogenic bacteria, and the spectrum of potential pathogens is broad. Taking several factors into account can narrow this spectrum, including severity of illness, length of stay before the onset of pneumonia, and presence of risk factors for specific pathogens. When therapy has been initiated, follow-up of microbial studies and careful monitoring of the patient's course is important. The clinical improvement, even when therapy is appropriate, frequently takes days; therapy should not be changed for the first 2 to 3 days unless frank deterioration is noted. Patients who fail to respond or experience clinical deterioration should be re-examined carefully, and thought should be given to the possibility of other noninfectious processes.

Nosocomial viral pneumonia in the intensive care unit.

The role viruses play in nosocomial ICU pneumonias is not well documented except for outbreaks of influenza and respiratory syncytial virus (RSV) infections. Clinically, viral pneumonias are difficult to differentiate from bacterial pneumonias, and most routine diagnostic tests are able to diagnose viral pathogens. Therefore, the incidence of viral pneumonias is almost certainly underestimated. The likelihood of a viral pneumonia is increased if the patient is not responding to antimicrobial agents, if pneumonia occurs during the winter months, or if there is evidence of viral outbreaks in the hospital or community. In the past few years, new diagnostic tests and a number of effective antiviral agents have been introduced; this makes the rapid diagnosis and treatment of viral pneumonia possible.

Drug-resistant pathogens in community- and hospital-acquired pneumonia.

Antimicrobial resistance has been a problem since the early days of the antibiotic era, but in recent years, this resistance has increased in the hospital and is being recognized more in the community setting. Respiratory pathogens such as S. pneumoniae and H. influenzae, for example, have developed resistance to traditional antimicrobial therapy, often over a very short period of time. This increase in resistance patterns requires physicians to closely monitor antimicrobial resistance in their community and to appreciate that some antimicrobial resistance mechanisms may result in resistance for a complete class of antibiotics or different classes of antibiotics with similar mechanisms of action.

Distribution of the Lyme disease vector, Ixodes dammini (Acari: Ixodidae) and isolation of Borrelia burgdorferi in Ontario, Canada.

Ixodes dammini Spielman, Clifford, Piesman & Corwin was confirmed at Long Point, Lake Erie, Ontario, on small mammals and white-tailed deer and by dragging for ticks. Mean intensities of up to 16.2 larvae and 2.1 nymphs were found on Peromyscus leucopus (Rafinesque), with an overall prevalence of infestation up to 92%. Adult I. dammini (101.6 +/- 77.63) (mean +/- SD) were found on 8 white-tailed deer, Odocoileus virginianus (Zimmerman). The seasonal pattern of recovery of ticks from hosts and the environment resembled that described elsewhere. I. dammini was not found on 952 small mammals trapped at 25 other localities throughout Ontario, although other ticks (Derma-centor variabilis (Packard), Ixodes angustus Neumann, I. marxi Banks, I. muris Bishopp & Smith) were encountered sporadically. I. dammini is not widespread or common in Ontario other than at Long Point. Borrelia burgdorferi was isolated from 10 of 151 P. leucopus; from larval and nymphal I. dammini; and from nymphal and adult D. variabilis, all from Long Point. B. burgdorferi was not recovered from 116 small mammals from localities other than Long Point. Seropositive P. leucopus (indirect fluorescent antibody test titer > or = 1:20) were common (up to 30% prevalence in July 1988, n = 23) on Long Point. Where I. dammini was not found, the prevalence of seroreactors among Peromyscus was 0 (15 sites), < 12% (5 sites), and 29% (1 site); seroprevalence at 1:20 could not be calculated for a further 4 sites examined in 1987. Antibody to B. burgdorferi was also detected in other small mammals at some sites. Such antibody was interpreted as possibly cross-reacting or caused by direct transmission.

Comparison of the in vivo and in vitro nuclear magnetic resonance detection of trifluoromethyl penicillin V in rats.

Fluorine nuclear magnetic resonance (NMR) spectroscopy and magnetic resonance imaging were examined as noninvasive methods for characterizing antibiotic disposition and pharmacokinetics in vivo. For determination of their utility, a 19F surface coil was constructed and an m-(trifluoromethyl)-containing penicillin V analogue (LY242072; 1) was synthesized. Various concentrations of 1 were injected intravenously into anesthetized rats whose urethras were occluded. The animals were placed on the surface coil, which was tuned to 19F, and then into a 4.7-T, 33-cm bore instrument, in which in vivo measurements of 1 were made on urine excreted into the bladder. At sacrifice, the urine was collected, and antibiotic levels were determined in vitro by both HPLC and high-resolution NMR. The limit of detection of 1 by NMR was 0.7 mg/mL of urine. When compared with standard in vitro quantitative methods using current technology, quantitation by in vivo surface coil NMR is not precise. Magnetic resonance imaging was used to image the bladder at a 35-mm3 voxel resolution with datum collection times of approximately 1 h. The 19F surface coil was used successfully to spectroscopically locate xenobiotic fluorine in the rat thorax. 19F NMR may offer an opportunity for the noninvasive in vivo detection of the distribution of various classes of therapeutic compounds.