The involvement of autoimmunity against retinal antigens in determining disease severity in toxoplasmosis

PURPOSE: Ocular lesions are frequent in various individuals infected with Toxoplasma gondii. Disease intensity in ocular toxoplasmosis varies greatly between patients. Autoimmunity has been suggested as a possible component to retinal destruction. METHODS: Immunologic parameters in the response to retina antigens were evaluated in infected persons with and without ocular lesions and in non-infected controls. Subjects were divided into groups on the basis of titers of serum antibodies to T. gondii, presence and severity of ocular lesions, and clinical history. RESULTS: Peripheral blood mononuclear cells from patients with mild disease responded to one or more retinal antigens with a significantly higher frequency than patients without disease or with severe disease. Interestingly, the cytokines produced by the proliferating mononuclear cells did not follow any specific patterns, except for the fact that IL-4 and IL-5 were seldom detected. CONCLUSIONS: Our results suggest that although the presence of an immune response towards autoantigens is not protective against the development of ocular lesions by the T. gondii, it may protect against the development of severe disease.     

Scanning electron microscopy study of the egg of Haemagogus (Haemagogus) capricornii Lutz, 1904 (Diptera: Culicidae)

Morphological details are provided for the dorsal and ventral surfaces of both extremities and the micropylar area of eggs of Haemagogus (Haemagogus) capricornii Lutz, captured in the Biological Reserve of Tinguá, State of Rio de Janeiro, Brazil. The eggs were observed by scanning electron microscopy with a morphometrical analysis of the main structures. The outer chorionic cells on the ventral surface were extremely regular, such as those observed in Hg. equinus and Hg. janthinomys. The tubercles present differences in form, size, and distribution. Filaments to attach to the substrate were observed in this species.     

Dogs may be a reservoir host for Angiostrongylus costaricensis

Angiostrongylus costaricensis is a parasitic nematode of wild rodents. Several other vertebrate species including man may become infected by ingestion of the third stage larvae produced by the intermediate hosts, usually slugs from the family Veronicellidae. There is a report of the diagnosis of abdominal angiostrongyliasis in Canis familiaris with lesions resembling those found in human disease. As a preliminar evaluation of the adequacy of a canine model for pathogenetic studies, a dog was inoculated with 75 L3 of A. costaricensis. Infection was established and fist stage larvae were found in feces up to 88 days post infection, sometimes in very large numbers (9.5 x 10(4) L1/g). No clinical manifestations or significant lesions were detected. These are indications that dog may play a role as a reservoir host for A. costaricensis.     

The effect of long-term intermittent trimethoprim/sulfamethoxazole treatment on recurrences of toxoplasmic retinochoroiditis

PURPOSE: To determine the effect of long-term intermittent trimethoprim/sulfamethoxazole treatment on recurrences of toxoplasmic retinochoroiditis. DESIGN: Prospective randomized open-labeled interventional clinical trial. METHODS: A total of 124 patients with a history of recurrent toxoplasmic retinochoroiditis were randomized to treatment with one tablet of trimethoprim (160 mg)/sulfamethoxazole (800 mg) (Bactrim F; Roche Pharmaceuticals, Rio de Janeiro, Brazil) every 3 days (61 patients) or to observation without treatment (63 patients) and were followed monthly for up to 20 consecutive months for clinical signs of disease recurrence. A recurrence was defined as a new focus of necrotizing retinochoroiditis with active inflammation either adjacent to or remote from preexisting retinochoroidal scars. RESULTS: Recurrences developed in four (6.6%) treated patients and in 15 (23.8%) controls (P =.01). Treatment was discontinued prematurely in four patients because of mild drug reactions. CONCLUSION: Long-term intermittent treatment with trimethoprim/sulfamethoxazole can reduce the rate of recurrent toxoplasmic retinochoroiditis.     

Ocular and central nervous system paracoccidioidomycosis in a pregnant woman with acquired immunodeficiency syndrome

PURPOSE: To describe an atypical case of central nervous system and ocular paracoccidioidomycoses simulating ocular toxoplasmosis in a pregnant woman with acquired immunodeficiency syndrome (AIDS). DESIGN: Interventional case report. METHODS: Case report. RESULTS: A 25-year-old pregnant woman with AIDS, presented with a severe ocular inflammation in the right eye involving the choroid, retina, and the optic disk, which rapidly progressed to retinal detachment, iris neovascularization, and neovascular glaucoma. The left eye was normal. Magnetic resonance imaging (MRI) showed a focal hypodense contrast-enhanced ring lesion in the brain. Serum antibody titers were negative for Toxoplasma gondii, but the polymerase chain reaction was positive for the parasite in the vitreous sample. The patient responded partially to specific treatment for toxoplasmosis, and there was a small reduction in size of the brain lesion. She progressed to a blind painful eye, which was enucleated. Paracoccidioides brasiliensis was found in the histopathological studies of the eye and oropharynx. With the diagnosis of disseminated ocular paracoccidioidomycoses, the patient was treated with trimethoprim-sulfamethoxazole with a satisfactory outcome and reduction in size of the brain lesion. CONCLUSION: Although ocular infection with ocular paracoccidioidomycoses is rare, this diagnosis should be considered when investigating ocular inflammation in a patient with AIDS.     

Prosthetic valve fungal endocarditis due to histoplasmosis

Fungal endocarditis is associated with severe patient morbidity and mortality. Unfortunately, fungal endocarditis is difficult to diagnose because fungal pathogens are uncommonly isolated from routine blood cultures. Histopathological examination of surgically excised cardiac valves, peripheral emboli and systemic ulcers may be useful in identifying pathogens as etiological agents of culture-negative endocarditis. The authors describe a 63-year-old man who had culture-negative endocarditis. Multiple echocardiograms showed progression of the vegetations with valve stenosis despite treatment with multiple antimicrobials. He had multiple peripheral emboli before surgery. Disseminated histoplasmosis was diagnosed by bone marrow culture. Yeast organisms consistent with histoplasma were shown in the vegetations of his excised mitral valve prosthesis. The patient was treated with amphotericin and has been doing well in the two years since his surgery. The diagnosis and management of fungal endocarditis are emphasized.     

Real-time US versus CT determination of pubic arch interference for brachytherapy

PURPOSE: Part 1, to determine whether transrectal ultrasonography (US) enables accurate determination of pubic arch interference (PAI) for prostate brachytherapy (PBT); part 2, to compare the accuracy of transrectal US with that of computed tomography (CT) for PAI determination; and part 3, to determine the cost savings of PAI determination with transrectal US versus that with CT. MATERIALS AND METHODS: Part 1: The pubic arch was identified intraoperatively with transrectal US and compared with attempted needle passage (14 patients). Part 2: Planning CT with the patient supine was compared with planning transrectal US with patients in the dorsal lithotomy position (nine patients). Part 3: Cost savings were calculated for PAI determination with transrectal US versus that with CT (32 patients per group). RESULTS: Part 1: Transrectal US accurately showed the pubic arch relative to the prostate. Part 2: CT resulted in PAI overestimation by 11.8 mm. Part 3: Cost savings with transrectal US were $1,465 per patient. CONCLUSION: Transrectal US PAI determination is easily performed, intraoperatively useful, and accurate. CT can result in PAI overestimation. Reducing direct CT costs and the indirect costs of unnecessary hormonal therapy for false-positive PAI will reduce expense and improve patient care. Transrectal US should replace CT for PAI determination.