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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.

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 μg 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 L =0.12±0.008), whereas C L of protein F-immunized rats (n=12, C L =0.17±0.006) was similar to that of noninfected control rats (n=5, C L =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.

Evidence for infection with the spirochete, Borrelia burgdorferi, was sought in Ixodes cookei and in groundhogs (Marmota monax) in southern Ontario, Canada, and ticks fed on experimentally inoculated hosts were examined for the spirochete. Borrelia burgdorferi was not detected by immunofluorescent examination of 110 larval, nymphal or adult I. cookei collected from the environment, or taken from humans and other animals. Three groundhogs inoculated with B. burgdorferi developed titers of 1:20 to 1:80 by the indirect immunofluorescent antibody test, but B. burgdorferi was not isolated from the spleens, kidneys, or urinary bladders of these animals. One of 30 wild groundhogs had an antibody titer of 1:20 to B. burgdorferi. Three (5%) of 59 I. cookei larvae fed on B. burgdorferi-infected hamsters became infected, in comparison with 23 (28%) of 82 I. dammini larvae fed on the same hosts. Borrelia burgdorferi was present in 5%, 16% and 4% of molted I. cookei nymphs fed on infected hamsters, rats or a groundhog, respectively; prevalences of infection in I. dammini fed on the same hosts were significantly (P0.05) higher (45%, 36%, and 23%, respectively), as was the intensity of infection. A naive groundhog on which I. cookei nymphs from an infected cohort fed did not become infected with B. burgdorferi, but it is uncertain whether an infected tick engorged on the experimental host. Ixodes cookei seems to be an inefficient vector of B. burgdorferi, and is unlikely to be significant in nature. Groundhogs are potential wildlife reservoirs of B. burgdorferi, based on their capacity to transmit infection to I. dammini.

Fish-eating birds can be exposed to levels of dietary methylmercury (MeHg) known or suspected to adversely affect normal behavior and reproduction, but little is known regarding Hg's subtle effects on the avian brain. In the current study, we explored relationships among Hg, Se, and neurochemical receptors and enzymes in two fish-eating birds--common loons (Gavia immer) and bald eagles (Haliaeetus leucocephalus). In liver, both species demonstrated a wide range of total Hg (THg) concentrations, substantial demethylation of MeHg, and a co-accumulation of Hg and Se. In liver, there were molar excesses of Se over Hg up to about 50-60 microg/g THg, above which there was an approximate 1:1 molar ratio of Hg:Se in both species. However, in brain, bald eagles displayed a greater apparent ability to demethylate MeHg than common loons. There were molar excesses of Se over Hg in brains of bald eagles across the full range of THg concentrations, whereas common loons often had extreme molar excesses of Hg in their brains, with a higher proportion of THg remaining as MeHg compared with eagles. There were significant positive correlations between brain THg and muscarinic cholinergic receptor concentrations in both species studied; whereas significant negative correlations were observed between N-methyl-D-aspartic acid (NMDA) receptor levels and brain Hg concentration. There were no significant correlations between brain Se and neurochemical receptors or enzymes (cholinesterase and monoamine oxidase) in either species. Our findings suggest that there are significant differences between common loons and bald eagles with respect to cerebral metabolism and toxicodynamics of MeHg and Se. These interspecies differences may influence relative susceptibility to MeHg toxicity; however, neurochemical responses to Hg in both species were similar.

To further understand the source of the epidemic of salmonellosis in some species of birds using bird feeders in southern Ontario in the winter of 1997-1998, 124 bird feeder stations were examined for their state of hygiene and for Salmonella on 5 occasions during the winter of 1999 in a city of 100,000 people in southwestern Ontario. No Salmonella were isolated from feed contaminated with feces recovered from the feeders. Squirrel-proof feeders were significantly less contaminated with feces than were other feeder types (hopper, platform, silo), which did not differ significantly in their hygiene scores. Contamination of squirrel-proof feeders increased significantly through the course of the study, but other feeder types showed no significant change. Hygiene was poorer if feeders were maintained equally by both male and female household members, particularly as they grew older, but no age or gender effect was observed if only one person was largely responsible for maintaining the feeders. We concluded that winter bird feeder stations in a southern Ontario city were not contaminated with Salmonella but that bird feeder stations could be designed better to reduce fecal contamination of feed.

The sensitivity and specificity of culture, acridine orange stain, and Gram stain were determined using needle aspiration (NA) material obtained from 82 rats with acute Pseudomonas aeruginosa pneumonia and 18 control rats. Lungs were then processed for either bacterial quantitation or histopathologic examination. NA culture proved to be the most sensitive and specific (55 and 100%, respectively). Sensitivity of acridine orange stain was 40%, whereas Gram stain was only 29%. The specificity of each stain was at least 94%. Lung bacterial concentrations influenced the sensitivities of all three techniques, with better sensitivity found in NA samples obtained from lung with bacterial concentration of at least 10(4) colony-forming units (cfu) of P. aeruginosa. Acridine orange and Gram stain results were similar except in NA samples from lung with bacterial concentration of less than 10(4) cfu in which acridine orange stain was more sensitive. The presence of stains identifying bacteria collected from animals with sterile NA culture was found in a small but significant number of samples, suggesting the presence of nonviable though stainable organisms. Use of all three techniques (culture, acridine orange stain, and Gram stain) increased sensitivity to approximately 70% with minimal decrease of specificity.

Guidelines for the treatment of blastomycosis are presented; these guidelines are the consensus opinion of an expert panel representing the National Institute of Allergy and Infectious Diseases Mycoses Study Group and the Infectious Diseases Society of America. The clinical spectrum of blastomycosis is varied, including asymptomatic infection, acute or chronic pneumonia, and extrapulmonary disease. Most patients with blastomycosis will require therapy. Spontaneous cures may occur in some immunocompetent individuals with acute pulmonary blastomycosis. Thus, in a case of disease limited to the lungs, cure may have occurred before the diagnosis is made and without treatment; such a patient should be followed up closely for evidence of disease progression or dissemination. In contrast, all patients who are immunocompromised, have progressive pulmonary disease, or have extrapulmonary disease must be treated. Treatment options include amphotericin B, ketoconazole, itraconazole, and fluconazole. Amphotericin B is the treatment of choice for patients who are immunocompromised, have life-threatening or central nervous system (CNS) disease, or for whom azole treatment has failed. In addition, amphotericin B is the only drug approved for treating blastomycosis in pregnant women. The azoles are an equally effective and less toxic alternative to amphotericin B for treating immunocompetent patients with mild to moderate pulmonary or extrapulmonary disease, excluding CNS disease. Although there are no comparative trials, itraconazole appears more efficacious than either ketoconazole or fluconazole. Thus, itraconazole is the initial treatment of choice for nonlife-threatening non-CNS blastomycosis.

The incidence of conjoined twins is rare, occurring in one in 50-80,000 live births. The rarity of the occurrence presents quite a management challenge. The first case in New Zealand of successfully separated thoraco-omphalagus twins, presenting top-to-tail, is described.

Nosocomial or hospital-acquired pneumonia occurs frequently, despite preventative measures and advances in diagnostic procedures and treatment of this severe infection. This article will highlight the recent literature with emphasis on significant publications and advances in the area of pneumonia pathogenesis, microbiology, diagnosis, and response to antimicrobial therapy.

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.

Community-acquired pneumonia (CAP) remains a major cause of morbidity and mortality in the United States. The ideal of a simple diagnostic evaluation yielding a specific etiologic diagnosis allowing directed antimicrobial therapy remains elusive. Empiric therapy is justified as initial management, as the specific bacteriological etiology of most cases of CAP is usually unknown, and delaying therapy while attempting to find a diagnosis may be injurious to the patient. Guidelines have been developed to assist in the recognition and evaluation of CAP based on age and underlying medical illness as predictors of outcome. While these criteria are by no means perfect and cannot be applied to every individual, they offer a rational approach to the initial management of the patient.

The duration of Borrelia burgdorferi infectivity in white-footed mice (Peromyscus leucopus) experimentally inoculated or infested with infected Ixodes scapularis nymphs was evaluated. Infectivity was assessed by infesting these mice with unfed I. scapularis larvae at 7, 21, 35 and 49 days post-inoculation (DPI) or post-infestation (PI). At 7 DPI, B. burgdorferi was transmitted from 18 of 24 syringe-inoculated mice and all three tick-infected mice to I. scapularis larvae which fed upon them. However, at 21, 35 and 49 DPI, significantly fewer mice were infective. Borrelia burgdorferi was isolated from tissues of 14 of 22 syringe-inoculated mice about 56 DPI, and from all three tick-infected mice. However, the level of agreement between xenodiagnosis and bacterial culture was no greater than would be expected by chance alone. We also determined if B. burgdorferi infectivity of mice varied in relation to periods of tick feeding in the field. White-footed mice were trapped during April, July and August 1993 from two habitats on Long Point peninsula (Ontario, Canada), where B. burgdorferi is endemic. Mice from each habitat were infested with laboratory-reared I. scapularis larvae. Ticks from each mouse were subsequently examined by immunofluorescent assay for B. burgdorferi infection and mice were cultured for B. burgdorferi. None of 3577 I. scapularis larvae fed on 62 mice captured within the cottonwood dune habitat were infected with B. burgdorferi, although it was isolated from six of these mice. Within the maple forest habitat, 0/24, 8/21 (38%) and 1/21 (5%) mice transmitted B. burgdorferi to I. scapularis larvae during April, July and August, respectively. Most mice from the maple forest with B. burgdorferi-positive tissues (14/21) were collected during July, although the level of agreement between xenodiagnosis and tissue culture was poor. Because B. burgdorferi infectivity in mice appears to be of short duration, overwintered I. scapularis larvae and nymphs may have to feed upon infected hosts at the same time of year in order for a cycle of B. burgdorferi infection to be maintained on Long Point. Infected I. scapularis nymphs, rather than persistently infected vertebrate hosts, likely serve as the overwintering "reservoir" for B. burgdorferi on Long Point.

During the 100 years since Blastomyces dermatitidis was discovered as a cause of human disease, diagnostic tests, methods of collection of specimens, and laboratory techniques have improved significantly. Radiographic advances and the introduction of the fiberoptic bronchoscopy have allowed for more reliable clinical diagnoses. More sensitive serologic techniques and DNA probes have significantly improved the sensitivity of laboratory diagnosis. At present, the most reliable serologic tests are the sandwich enzyme immunoassay (sensitivity 88%, specificity 100%) and the 120-kd antigen radioimmunoassay (sensitivity 85%, specificity 100%). When positive and negative predictive values are applied, the sandwich enzyme immunoassay appears to be the most accurate. At the present time, a negative serologic test cannot be used to exclude blastomycosis. Further advances in refining the B dermatitidis antigen(s) for use in the newer, more sensitive, and specific assay techniques may allow for a definitive serologic diagnosis in the future, avoiding the necessity for invasive tests.

Recent clinical data suggest that fluconazole at daily doses of 200 to 400 mg for at least 6 months is moderately effective therapy for non-life-threatening blastomycosis. To examine the usefulness of higher doses of fluconazole therapy for this disorder, we conducted a multicenter, randomized, open-label study to determine the efficacy and safety of two different daily doses of fluconazole (400 and 800 mg) in the treatment of non-life-threatening blastomycosis. Of 39 patients evaluable for efficacy analysis, 34 (87%) were successfully treated, including 89% and 85% of patients who received 400 and 800 mg, respectively. Five (83%) of six patients for whom prior antifungal therapy had failed were successfully treated. The mean duration of therapy was 8.9 months for successfully treated patients. Nineteen patients (48%) reported adverse events, although most were minor. We conclude that fluconazole at daily doses of 400 to 800 mg for at least 6 months is effective therapy for non-life-threatening blastomycosis.

The intrapulmonary pharmacokinetics of oral azithromycin were studied in 25 healthy volunteers, each of whom received an initial dose of 500 mg and then 250 mg once daily for four additional doses. Bronchoscopy, bronchoalveolar lavage, and venipuncture were performed 4, 28, 76, 124, 172, 244, 340, and 508 h after the first dose was administered. Azithromycin concentrations in epithelial lining fluid (ELF), alveolar macrophages, peripheral blood monocytes, and serum were measured by high-performance liquid chromatography. Azithromycin was extensively concentrated in cells and ELF. Drug concentrations in AMs (peak mean +/- standard deviation, 464 +/- 65 micrograms/ml) exceeded 80 micrograms/ml up to 508 h (21 days) following the first dose, while concentrations in PBMs (peak, 124 +/- 28 micrograms/ml) exceeded 20 micrograms/ml up to 340 h (14 days). Azithromycin concentrations in ELF peaked at 124 h (3.12 +/- 0.93 micrograms/ml) and were detectable up to 172 h (7 days), when they were 20 times the concurrent serum concentrations. Although the clinical significance of antibiotic concentrations in these compartments is nuclear, the sustained lung tissue penetration and extensive phagocytic accumulation demonstrated in this study support the proven efficacy of azithromycin administered on a 5-day dosage schedule in the treatment of extracellular or intracellular pulmonary infections.

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 p0.001). 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.

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.

The keynote address at the Congress of the SA Society of Psychiatrists in 1994 1 , was delivered by Professor J.L. Cummings, on Neuropsychiatry-the state of the science. He said that structural imaging with CT and MRI and functional imaging using PET and SPECT, have greatly increased our knowledge of which parts of the brain, are affected in the various forms of neuropsychiatric disorders. He went on to say that Schizophrenia is associated with increased brain ventricular size and specific atrophy of the frontal lobes... (in schizophrenia). We have also begun to realise the importance of the frontal lobes with the basal ganglia and the thalamus, and then project back to the frontal lobes... in neuropsychiatry we are largely talking about system syndromes, and are not looking for a schizophrenic centre or a depression centre. At the SA Congress of Biological Psychiatry in 1991, Andreassen 2 had presented an important description of monovular-discordant-for-schizophrenia twins' brain studies by PET (Positron Emission Tomography) which suggested a high probability that schizophrenia might be a developmental disorder resultant upon a toxic or viral prior disorder. We report upon three siblings in a family, from whose kitchen food stores multiple mycotoxins were isolated. 3

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 (p0.01) reduction in the number of severe pulmonary lesions as compared with bovine serum albumin-immunized rats. Lung compliance (CL) was significantly (p0.001) 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.

Pneumonia is a common and important infectious disease in all age groups but especially in the elderly. Mortality and morbidity are quite high when associated with certain risk factors such as comorbid medical conditions and clinical features that implicate more severe disease. In the absence of such features, patients can be treated quite safely out of the hospital, as long as followup and compliance issues are not a problem. Therapy should be directed toward gram-positive and gram-negative aerobic bacteria and, at times, be further expanded to cover atypical organisms such as Legionella sp. Appropriate antimicrobial agents are those that not only cover expected microorganisms but are compatible with each patient's existing medical regimen.

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.

Bacterial endotoxin has been shown to protect rats from lethal hyperoxia. The structure of endotoxin contains diphosphoryl lipid A (DPL) as the lipid backbone stripped of protein and polysaccharides. DPL is the component of the endotoxin molecule that has been demonstrated (in previous studies) to be responsible for the immunologic, mitogenic, pyrogenic, and lethal properties of endotoxin. Monophosphoryl lipid A (MPL) is a nonpyrogenic, nontoxic modification of the DPL molecule that retains its immunostimulatory and mitogenic properties. We hypothesized that DPL may be the actual active component of endotoxin that protects rats from lethal hyperoxia. We also hypothesized that the protection from hyperoxia that is afforded by the DPL component may be related to endogenous release of tumor necrosis factor alpha which should allow MPL to also be protective. To test these hypotheses, we performed a series of experiments in which rats were treated with endotoxin, DPL, MPL or vehicle and exposed to room air or hyperoxia. We found that DPL and endotoxin both protected rats from lethal hyperoxia, but MPL alone was not protective. Even though MPL was not protective, DPL and MPL both increased endogenous release of tumor necrosis factor alpha early after injection (peak DPL level, 3619 +/- 1500 pg/ml, peak MPL level, 4038 +/- 500 pg/ml). Protection in both the endotoxin- and DPL-treated animals was associated with increases in lung antioxidant enzyme activities. We concluded that DPL protect rats from hyperoxia but that MPL is not protective in spite of its immunostimulatory and mitogenic effects.

Pleural effusion may result from many disorders, some of them serious. Fortunately, this body fluid is easily accessible, and knowledge of its characteristics is an important tool in diagnosing the underlying disease. The authors describe radiographic and laboratory tests to use in determining the source of the problem.

1. The effects of vagal stimulation and applied acetylcholine were compared on sinus venosus preparations of the toad, Bufo marinus, in which beating had been inhibited by adding the organic calcium antagonist nifedipine. 2. Bath-applied acetylcholine and vagal stimulation each caused membrane hyperpolarizations which were abolished by hyoscine. 3. Whereas the hyperpolarization that accompanied vagal stimulation was largely unaffected by barium ions, that produced by bath-applied acetylcholine was almost abolished. 4. Caesium ions also prevented the hyperpolarization produced by bath-applied acetylcholine but potentiated the responses to vagal stimulation. 5. The membrane resistance of arrested sinus venosus cells was found to be higher during vagal stimulation than in the absence of stimulation. In contrast when a similar hyperpolarization was produced by adding acetylcholine, the membrane resistance was found to be lower than in control solution. 6. The results are discussed in relation to the idea that neuronally released acetylcholine causes membrane hyperpolarization by suppressing inward current flow and applied acetylcholine acts to increase outward current flow.

The composition and antibiotic permeability barrier of the outer membrane of Serratia marcescens were assessed in cells grown in vivo and in vitro. Intraperitoneal diffusion chambers implanted in rats were used for the in vivo cultivation of bacteria. Outer membranes isolated from log-phase bacterial cells recovered from these chambers were compared with membranes isolated from cells grown in vitro. Analysis revealed that the suspected 41-kilodalton porin and the OmpA protein were recovered on sodium dodecyl sulfate-polyacrylamide gels in equal quantities. Several high-molecular-weight proteins, thought to be iron starvation induced, appeared in the diffusion chamber-grown cells. The outer membrane permeability barriers to cephaloridine were similar in in vivo- and in vitro-grown cells based on permeability coefficient calculations. The permeability coefficient of cephaloridine in S. marcescens cells (30.3 x 10(-5) to 38.9 x 10(-5) cm s-1) was greater than that obtained for an Escherichia coli strain expressing only porin OmpC but smaller than those obtained for the E. coli wild type and a strain expressing only porin OmpF. Functional characterization of the suspected porin was performed by using the planar lipid bilayer technology. The sodium dodecyl sulfate-0.4 M NaCl-soluble porin from both in vitro- and in vivo-grown cells showed an average single-channel conductance in 1 M KCl of 1.6. A partial amino acid sequence (19 residues) was obtained for the S. marcescens porin. The sequence showed a very high homology to the E. coli OmpC porin. These data identified the S. marcescens outer membrane 41-kilodalton protein as a porin by both functional and amino acid analyses. Also, the methodology used allowed for efficient growth and recovery of diffusion chamber-grown bacterial cells and permitted identification of specific in vivo-induced changes in bacterial cell membrane composition.

Interleukin-1 (IL-1), a modulatory protein with immune and inflammatory functions, is spontaneously released by tissue macrophages in lower concentrations compared with peripheral blood monocytes. Conversely, in idiopathic pulmonary fibrosis, sarcoidosis, and certain inflammatory diseases, increased amounts of IL-1 are released by alveolar macrophages (AM). We examined IL-1 production by AM from patients with adult respiratory distress syndrome (ARDS) and compared it with that in patients with severe pneumonia requiring assisted ventilation, patients with pneumonia requiring parenteral antibiotics, and healthy control subjects. In vitro, ARDS AM released significantly more total IL-1 and IL-1 beta than did ARDS AM in patients with pneumonia and in control subjects. Moreover, after stimulation of these cells with 10 micrograms/ml of lipopolysaccharide (LPS), ARDS AM significantly increased release of IL-1 and IL-1 beta. AM from patients with severe pneumonia also released greater amounts of both IL-1 and IL-1 beta as fresh explants and after LPS stimulation when compared with control subjects. Incubation of AM with 250 U/ml human interferon-gamma (gamma IFN) was associated with less IL-1 beta release. However, stimulating AM from patients with ARDS and severe pneumonia with gamma IFN plus LPS enhanced the release of IL-1 beta compared with that in patients with pneumonia and in control subjects. ARDS AM released significantly more IL-1 beta than did all of the other groups. These results demonstrate that AM from patients with ARDS are capable of releasing significantly greater amounts of IL-1, which may be related to the progression of acute lung injury.

1. Intracellular recordings were made from pacemaker cells lying in the sino-atrial node of guinea-pigs. 2. Low-frequency vagal stimulation slowed the rate of generation of pacemaker action potentials; high-frequency stimulation stopped the generation of action potentials. 3. During vagal stimulation the rate of diastolic depolarization was reduced with the action potential otherwise unchanged: when the heart stopped the membrane potential of pacemaker cells settled to a value positive of the maximum diastolic potential. 4. In contrast, added acetylcholine caused membrane hyperpolarization and shortened the duration of action potentials. 5. The effects of both added acetylcholine and vagally released acetylcholine were abolished by hyoscine. 6. It is suggested that neurally released acetylcholine acts to change the balance between inward and outward current flow during diastole by modifying the properties of existing voltage-dependent channels. In contrast added acetylcholine appears to activate a different set of receptors which increase the potassium conductance of pacemaker cells.

The 899 offspring of Natal Indian diabetic couples are compared with the general Indian population. Diabetes was present in 25% of offspring aged 40– 49 as against 14.7% of the general population. The ratio of offspring diabetics to population diabetics diminished with age, suggesting that the genetic influence affects mainly age of onset of diabetes. “Old” and “young” diabetic couples had a similar proportion of diabetic children. Another similar comparison could be made between an inbred Tamil Indian family in Cape Town and the general population of Cape Hindus. More young diabetics were obese than old diabetics, in3 different racial groups and in both “clinic” and “survey” diabetics, whereas in the general population obesity is more common over age 40. Overweight may be a more important diabetes risk factor in young than in old people.

A study has been made of catecholamine stores that may be involved in cardiac regulation in the shark Heterodontus portusjacksoni. The anatomy of the anterior chromaffin bodies associated with the sympathetic chain is described. A fluoresent histochemical study shows that the chromaffin cells contain a monoamine, probably noradrenaline. The chromaffin cells have a fine structure comparable to that of chromaffin cells in other vertebrates. The heart is devoid of histochemically-demonstrable chromaffin cells or adrenergic nerve fibres, with the exception of a very sparse adrenergic innervation of the sinus venosus. It is argued that adrenergic control of the heart in Heterodontus might occur via amines released from the anterior chromaffin masses into the blood in the posterior cardinal sinus, which is then aspirated directly into the heart.

Cutaneous lesions as a manifestation of histoplasmosis, primarily a disease of the respiratory system, are rare and most commonly appear secondary to progressive dissemination. A patient with documented progressive, disseminated histoplasmosis, having been treated previously with amphotericin B, presented on a second occasion with cutaneous lesions as the chief complaint. Biopsy and cultures of these lesions were positive for Histoplasma capsulatum. A review of the English literature revealed only 7 reported cases of secondary skin histoplasmosis in the past 20 years. All patients, including the current one, either had diseases associated with depressed immunity or were receiving steroid therapy.

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.

Although bacterial infection is very common in patients with adult respiratory distress syndrome (ARDS), the effects of infection on the clinical course of ARDS are unknown. We have studied the effects of gram-negative bacillary infections in 21 baboons during periods of prolonged anesthesia and ventilatory support. Sixteen animals received oleic acid, 0.04 to 0.06 ml/kg intravenously; 7 developed no infections, 5 developed nosocomial pneumonias, and 4 inadvertently received intravascular infusions of Serratia marcescens. Five uninjured animals were studied; all developed pneumonia. In the absence of infection, oleic-acid-induced lung injury was mild and all animals were successfully weaned. Uninjured animals that developed pneumonia demonstrated only mild abnormalities of lung function, but 4 of 5 died of complications of their infections. Gram-negative bacillary infections superimposed upon oleic acid injury produced rapid and marked deterioration of lung function. Acquired infection, either of the lung itself or at remote sites, may markedly worsen lung function in the presence of a previous lung injury.

A rare association of female phenotype with the 47,XYY karyotype in a 14-year-old White girl is described. She was studied because of her short stature and proved to have gonadal dysgenesis. She showed no masculinization and there were no Turner stigmata. Her intelligence was normal, she was sociable and her outlook was feminine.

Gram-negative bacillary pneumonias represent a major problem in hospitalized patients. A major research interest has been towards the development of rapid and accurate diagnostic procedures for these infections. An ELISA procedure for the detection of lipid A in pulmonary lavage fluid has been developed. Using the quantitation of lipid A, an antigen common to all clinically important gram-negative bacilli, as a marker for gram-negative bacilli, the presence or absence of pneumonia caused by these organisms could be demonstrated in laboratory animals. Additionally, by quantitating the lipid A associated with the lavageable pulmonary cell population, a measure of bacterial lung clearance could be obtained.