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Background: The report details a case of diffuse unilateral subacute neuroretinitis (DUSN) wherein a subretinal parasite was visualized and subsequently destroyed with laser photocoagulation., Methods: Full historical and serologic investigations were carried out. A literature search to determine all possible causes of DUSN was also completed., Results: Serologic results supported Baylisascaris procyonis as the cause of infection, but imaging of the worm before destruction did not support this organism as the etiologic agent. On the basis of morphologic evaluation of still imaging and videoimaging, patient exposure information, and known causes of DUSN, the infection was likely due to Alaria species, providing further evidence of a trematode cause., Conclusions: The report adds to the literature that trematodes should be recognized as a possible cause of ocular larva migrans. Although laser therapy is appropriate and effective for both nematode and trematode infections of the eye, in the case of adjunctive medical therapy, identification of the parasite group is essential.

A 36-year-old man with advanced AIDS presented with skin lesions, fever and weight loss. Physical examination revealed skin lesions suggestive of bacillary angiomatosis. Diagnostic imaging identified bone lesions, soft tissue masses and a single hepatic lesion. His clinical presentation was most consistent with Bartonella quintana; however, his risk for infection with B quintana was limited to a remote, brief period of homelessness. In contrast, his frequent contact with cats presented substantial potential exposure to Bartonella henselae.Diagnosing a Bartonella infection presents challenges. The detection of bacteremia is hindered by slow growth in BACTEC media (BD Diagnostic Systems, Canada). In the present case, recovery of the organism required blind subcultures after at least eight days of incubation. Speciation by 16s ribosomal RNA analysis confirmed B quintana as the pathogen.Because the patient presented with skin lesions, the diagnosis was straightforward; however, skin lesions are nondiagnostic in some cases. Microbiological confirmation of the diagnosis rests on sufficient clinical suspicion to apply labour-intensive laboratory protocols.

We report 2 clinically characteristic and serologically positive cases of Ross River virus infection in Canadian tourists who visited Fiji in late 2003 and early 2004. This report suggests that Ross River virus is once again circulating in Fiji, where it apparently disappeared after causing an epidemic in 1979 to 1980.

Purpose: Obtaining informed consent is an essential skill in internal medicine (IM). The authors' informal observations and formal testing revealed deficiencies in residents' informed consent skills. This study evaluated how residents acquire informed consent skills and how informed consent skills are addressed in Canadian IM residency programs., Method: A questionnaire was delivered to all 16 IM program directors in Canada, asking how informed consent is taught and assessed. At the University of Saskatchewan IM residency program, residents were assessed through an objective structured clinical examination station, written examination, and a self-assessment questionnaire., Results: No consistent approach to teaching or evaluating informed consent skills exists within Canadian IM programs. Program directors and residents identified informal mentoring by residents as an important learning modality. Although residents performed well in discussing procedural indications and techniques, discussing risks was inadequate. Residents focused on general and minor risks but avoided discussing serious risks and had difficulty discussing the frequency of complications. Residents lacked a structured approach to assessing capacity and often assessed only comprehension. Residents were unfamiliar with concepts such as material risk, implied consent, and therapeutic privilege., Conclusion: Explicit training in informed consent skills is urgently needed. Informal mentoring must be recognized as an important training method for informed consent and supported by appropriate teaching and evaluation strategies to ensure that resident-instructors do so effectively.

Malaria continues to be an increasing health concern in many endemic areas where it remains a major contributor to childhood morbidity and mortality. Chemoprophylaxis and treatment are increasingly compromised by drug resistance. Vaccination for malaria is not yet available outside clinical trials. In clinical trials bed nets have been shown to be effective in reducing malarial morbidity and mortality. Their efficacy outside of the clinical trial setting has been less well documented. We describe our experience with the introduction of bed nets in a remote rural Zambian village and document the effect on malarial parasitaemia, spleen rates and haemoglobin. Children were evaluated at the end of the rainy seasons in April 1998 and April 1999. Insecticide impregnated nets were made available for purchase to the village in July 1998. Rates of parasitaemia and anaemia were significantly reduced.

A 58-year-old woman presented with progressive midforehead swelling and erythema with frontal headache. Investigations revealed erosion of the anterior wall of the frontal sinus with subgaleal abscess formation, establishing a diagnosis of Pott's puffy tumour. Pasteurella multocida was isolated in pure growth from an aspirate of the abscess. P multocida is a rare cause of sinusitis. It is isolated from the respiratory tract of asymptomatic individuals and, more commonly, patients with chronic respiratory conditions. Although a cause of osteomyelitis associated with animal bites or scratches, P multocida has not previously been implicated as a cause of frontal osteomyelitis or Pott's puffy tumour. A review of reported cases of Pott's puffy tumour, including clinical presentation, microbiology, treatment and outcome, is provided.

Three cases of plague, all with pneumonic involvement, occurred in a small village in northwestern Zambia. Initial recognition of the diagnosis was delayed, but the outbreak was terminated by rapid intervention with insecticides and with the use of chemoprophylaxis for individuals with high-risk exposures to case-patients.

Significant advances in our understanding of the pathogenesis and microbiology of intraabdominal sepsis have been made over the past 15 years. There has also been progress in various aspects of diagnosis and treatment of these infections. Computed tomography and ultrasonography have simplified the diagnosis of an intraabdominal abscess, and percutaneous drainage of abscesses has become an acceptable alternative to surgery. Novel surgical approaches have been tried, but their true role is not yet defined. A broader selection of less-toxic antimicrobial agents is now available as treatment for intraabdominal infection. The role of superinfecting pathogens is more clearly defined. Patients who would have died of this infection in a previous era now survive because of an array of supportive therapies.

Fluoroquinolones are active against Plasmodium falciparum in vitro. In a prospective, randomized, comparative trial, norfloxacin, 400 mg twice a day for 3 days, was compared with a standard course of chloroquine in semiimmune adults with symptomatic falciparum malaria in northwestern Zambia, where chloroquine resistance is uncommon. Patients were followed for 28 days. The trial was terminated after 38 patients were studied because chloroquine was markedly more effective, curing all 18 patients (100%) compared with only 8 (40%) of 20 who received norfloxacin (P less than .001). Of the 12 norfloxacin failures, 6 had clearing of trophozoites but recurrence during the study period (RI), 4 had incomplete clearance of trophozoites with later recurrence (RII), and 2 had no improvement (RIII). The mean parasite clearance time was significantly shorter with chloroquine (30.4 vs. 52.7 h; P = .02). The mean defervescence time was also shorter with chloroquine (16.9 vs. 24.5 h; not significant). In contrast to its inferior efficacy, norfloxacin caused fewer adverse effects than did chloroquine (33% vs. 0; P less than .001).

The accuracy of tracer methods for estimating free fatty acid (FFA) rate of appearance (Ra), either under steady-state conditions or under non-steady-state conditions, has not been previously investigated. In the present study, endogenous lipolysis (traced with 14C palmitate) was suppressed in six mongrel dogs with a high-carbohydrate meal 10 h before the experiment, together with infusions of glucose, propranolol, and nicotinic acid during the experimental period. Both steady-state and non-steady-state equations were used to determine oleate Ra ([3H]oleate) before, during, and after a stepwise infusion of an oleic acid emulsion. Palmitate Ra did not change during the experiment. Steady-state equations gave the best estimates of oleate inflow approximately 93% of the known oleate infusion rate overall, while errors in tracer estimates of inflow were obtained when non-steady-state equations were used. The metabolic clearance rate of oleate was inversely related to plasma concentration (P less than 0.01). In conclusion, accurate estimates of FFA inflow were obtained when steady-state equations were used, even under conditions of abrupt and recent changes in Ra. Non-steady-state equations, in contrast, may provide erroneous estimates of inflow. The decrease in metabolic clearance rate during exogenous infusion of oleate suggests that FFA transport may follow second-order kinetics.

JH imple and reliable method for the determination of ketone body turnover in vivo using a primed, continuous infusion of [3,4-13C2]acetoacetate is described. Mole percent enrichment of beta-[13C2]hydroxybutyrate and [13C2]acetoacetate is determined by gas chromatography/mass spectrometry using electron-impact ionization and selected ion monitoring. Ketone body flux data are provided from preliminary dog experiments. The method is readily applicable to the study of ketone body metabolism in both laboratory animals and humans.

"Total ketone body specific activity" has been widely used in studies of ketone body metabolism to circumvent so-called "isotope disequilibrium" between the two major ketone body pools, acetoacetate and beta-hydroxybutyrate. Recently, this approach has been criticized on theoretical grounds. In the present studies, [13C]acetoacetate and beta-[14C]hydroxybutyrate were simultaneously infused in nine mongrel dogs before and during an infusion of either unlabeled sodium acetoacetate or unlabeled sodium beta-hydroxybutyrate. Ketone body turnover was determined using total ketone body specific activity, total ketone body moles % enrichment, and an open two-pool model, both before and during the exogenous infusion of unlabeled ketone bodies. Basal ketone body turnover rates were significantly higher using [13C]acetoacetate than with either beta-[14C]hydroxybutyrate alone or the dual-isotope model (3.6 +/- 0.5 vs. 2.2 +/- 0.2 and 2.7 +/- 0.2 mumol X kg-1 X min-1, respectively, P less than 0.05). During exogenous infusion of unlabeled sodium acetoacetate, the dual-isotope model provided the best estimate of ketone body inflow, whereas 14C specific activity underestimated the known rate of acetoacetate infusion by 55% (P less than 0.02). During sodium beta-hydroxybutyrate infusion, [13C]-acetoacetate overestimated ketone body inflow by 55% (P = NS), while better results were obtained with 14C beta-hydroxybutyrate alone and the two-pool model. Ketone body interconversion as estimated by the dual-isotope technique increased markedly during exogenous ketone body infusion. In conclusion, significant errors in estimation of ketone body inflow were made using single-isotope techniques, whereas a dual-isotope model provided reasonably accurate estimates of ketone body inflow during infusion of exogenous acetoacetate and beta-hydroxybutyrate.(ABSTRACT TRUNCATED AT 250 WORDS)