Investigation on the possibility of spontaneous cure of mice infected with different strains of Trypanosoma cruzi

Seventy Swiss mice chronically infected with different strains of Trypanosoma cruzi, with persistently negative parasitemia on routine blood examination were parasitologically investigated to find out whether spontaneous cure occurred. Duration of infection varied from 90 to 250 days in the initial phase of this investigation. Parasitological tests consisted of daily direct blood examination performed during at least 25 days, followed by xenodiagnosis and subinoculation of blood into newborn mice. Mice that persisted negative were treated with Cyclophosphamide with one dose of 250 mg/kg of body weight and then investigated by direct blood examination, xenodiagnosis and subinoculation. A second dose of 250 mg/kg b. w. was given to the persistently negative mice. With one single exception, all mice showed positive parasitological tests in the different stages of the present investigation and we conclude that spontaneous cure did not occur in this group, which is representative of the chronic infection with different strains of T cruzi.

Spontaneous morphogenetic juvenilization observed in laboratory populations of vector species of Chagas disease (Triatominae)

Reported are observations on spontaneous occurring morphogenetic juvenilization in laboratory populations of vector species of Chagas disease. Two general effects have been observed: arrested development and uncoordinated development. These are manifested by supernumerary nymphs (6th stage), intermediate nymphal-adult stages, badly deformed adults developed from 5th instar nymphs, uncoordinated development manifested by grotesque forms of adults, supernumerary adults unable to complete metamorphosis and complete supernumerary adults produced by 6th stage nymphs. The reoccurrence of insects with identical grades of juvenilization in the population is an indication that this is a genetic trait that might be inherited. The factors responsible for morphogenetic juvenilization cannot be transmitted through the juvenilized insects because they are sterile, than they were transmitted through normal insects probably as a recessive or a group recessive factors. The spontaneous morphogenetic juvenilization observed in laboratory populations has a striking similarity to juvenilizing effects induced by application of juvenile hormone analogues, described in the literature and also obtained in our laboratory in a study to be published. Thus it is suggested that both; the altered phenotypes occurring in wild populations and their "phenocopies" induced by the application of juvenile hormone analogues are products of gene controlled identical reactions.

Does a spontaneous cure for chagas' disease exist?

Six Costa Rican Chagas' disease patients, with wellknown acute phase history and no specific treatment were examined in several occasions during 39, 24, 32, 16 and 14 years, respectively, from the onset. Nome of the patients presented heart abnormalities as revealed by the conventional EKG and ergometry, exceptfor one of them with an incomplete block of the right bundle branch. Also, no alterations of the oesophagus motility was detected manometrically except for another patient who presented a slight hypersensivity reaction to a pharmacological test (Mecholyl). Three out of six patients became serologically negative in 1981, remaining as such until 1986. Besides the conventional serology, the search of protective ("lytic") antibodies was also performed in 1985 and 1986, being completely negative in one of the "cured" patients and dubious in the other two. The hypothesis that these three patients had as spontaneous cure, based on the clinical, serological and parasitologica l findings is discussed.

Spontaneous regional heading of extensive skin lesions in diffuse cutaneous leishmaniasis (DCL)

The authors report a case of diffuse cutaneous leishmaniasis, with longstanding evolution and presenting with diffuse infiltrated lesions rich in amastigotes in the absence of mucosal involvement. In situ characterization with monoclonal antibodies revealed Leishmania amazonensis. Large regional lesions have presented spontaneous healing without specific therapy. Considering that DCL presents with a defect in the cellular immune response, thisfact demonstrate that this patient may develop a regional cellular immune response enough to destroy the parasites and to produce clearing of some lesions.

New evidence of spontaneous cure in human Chagas' disease

A new case of spontaneous cure of human Chagas' disease is described in Uruguay. An 87-year-old man who had a typical acute phase of Trypanosoma cruzi infection in 1947 and never received specific treatment against the disease, when examined in 1998 revealed several completely negative parasitological and serological tests, including traditional serology, PCR and flow cytometry. As a whole, such findings fulfill the current criteria to define the cure of Chagas' disease. Clinical data suggest the possibility of a benign evolution of Chagas' disease in this case, but the basic findings (slight cardiac and esophageal impairment) could also be due to the advanced age of the patient.

Further evidence of spontaneous cure in human Chagas disease

An acute case of Chagas disease was studied in 1944, with clinical and laboratory follow-up until 2007, in Bambuí, Minas Gerais, Brazil. A five-year-old girl living in a rural hut that was highly infested with Triatoma infestans presented a febrile clinical condition compatible with the acute form of trypanosomiasis. She presented a positive thick blood smear, but never again showed serological and/or parasitological evidence of Trypanosoma cruzi infection, on several occasions. This patient never received any specific treatment and, to this day, she remains completely asymptomatic, with normal findings from clinical, electrocardiographic, X-ray and echocardiographic examinations.

Abnormal spontaneous interleukin 8 receptor expression: a brief report of two cases

Interleukin 8 (CXCL8) is an autocrine chemokine specific for the chemoattraction and activation of granulocytes, NKT cells and T lymphocytes. Patients with tuberculosis and latent Mycobacterium tuberculosis infection were assessed for the spontaneous expression of CXCR1 (CD128) and CXCR2 on lymphocytes and monocytes. Compared with ex vivo profiles, increased spontaneous CXCR2 expression and normal CXCR1 expression were found on lymphocytes in two out of 59 individuals. Monocytes showed normal ex vivo profiles for both receptors. After stimulation with purified protein derivative, the in vitro levels of CXCL8 were below the median levels of all patients with prior tuberculosis. Spontaneous CXCR2 modulation did not cause notable variation in the in vitro levels of CXCL8.

Parasitological stool sample exam by spontaneous sedimentation method using conical tubes: effectiveness, practice, and biosafety

INTRODUCTION: Spontaneous sedimentation is an important procedure for stool examination. A modification of this technique using conical tubes was performed and evaluated. METHODS: Fifty fecal samples were processed in sedimentation glass and in polypropylene conical tubes. Another 50 samples were used for quantitative evaluation of protozoan cysts. RESULTS: Although no significant differences occurred in the frequency of protozoa and helminths detected, significant differences in protozoan cyst counts did occur. CONCLUSIONS: The use of tube predicts a shorter path in the sedimentation of the sample, increases concentration of parasites for microscopy analysis, minimizes the risks of contamination, reduces the odor, and optimizes the workspace.

Spontaneous reporting of adverse events following pandemic influenza A (H1N1) immunization in a reference center in the State of Sao Paulo, Brazil

Introduction This paper describes adverse events (AEs) temporally associated to the pandemic influenza A (H1N1) vaccine observed in a reference center in São Paulo, Brazil, during a 2010 mass vaccination campaign. Methods A retrospective study involving persons who sought medical care for AEs following influenza vaccination. Data were retrieved from medical records, vaccine AE notification forms, and a computerized system for immunobiological registration. Results Sixty-six vaccinees sought medical care for AEs after immunization. The most frequent AEs were fever, headache, myalgia, and pain at the injection site. No serious AEs were reported. Conclusions Few vaccinees spontaneously reported AEs to influenza A (H1N1) vaccine at this center.

Recurrent spontaneous breast hematoma: report of a case and review of the literature

BACKGROUND: Breast hematomas are common after traumas, surgeries, or contusions. They are rarely spontaneous, but they can occur spontaneously in patients with hematologic disease or with coagulation disorders. MATERIAL AND METHODS: The authors report a clinical case of a 48-year-old female with a 27-year history of paroxysmal nocturnal hemoglobinuria who underwent mammography screening because of a painless palpable moveable node in the upper inner quadrant of the right breast. RESULTS: Mammography showed a partially defined heterogeneous node of 35 mm without microcalcifications in the upper inner quadrant of the right breast which, associated with the clinical features, seemed to be an hematoma. Further mammography and ultrasound after 45 days showed retrocession of the lesion, and another mammography obtained after 60 days was normal. Seventy-five days after the first episode, the patient complained of another node with a skin bruise in the upper outer quadrant of the same breast, which seemed to be a recurrent hematoma. Two months later the mammography obtained was normal. CONCLUSION: Breast hematoma must be thought of as a differential diagnosis for a breast node, regardless of previous trauma or hematologic disorders.

Spontaneous rupture of a right atrial angiosarcoma and cardiac tamponade

Primary cardiac angiosarcoma is a rare disease of difficult diagnosis and poor prognosis frequently associated with recurring hemopericardium. We report the case of a 30-year-old female with a right atrial angiosarcoma and spontaneous rupture to the pericardial cavity, who was diagnosed during an emergency exploratory thoracotomy, whose indication was cardiac tamponade. This is the 8th case reported in the literature. Clinical findings are discussed and a literature review is provided.

Morphological aspects of the myocarditis and myositis in Calomys callosus experimentally infected with Trypanosoma cruzi: fibrogenesis and spontaneous regression of fibrosis

Calomys callosus a wild rodent, is a natural host of Trypanosoma cruzi. Twelve C. callosus were infected with 10(5) trypomastigotes of the F strain (a myotropic strain) of T. cruzi. Parasitemia decreased on the 21 st day becoming negative around the 40th day of infection. All animals survived but had positive parasitological tests, until the end of the experiment. The infected animals developed severe inflammation in the myocardium and skeletal muscle. This process was pronounced from the 26 th to the 30th day and gradually subsided from the 50 th day becoming absent or residual on the 64 th day after infection. Collagen was identified by the picro Sirius red method. Fibrogenesis developed early, but regression of fibrosis occurred between the 50th and 64th day. Ultrastructural study disclosed a predominance of macrophages and fibroblasts in the inflammatory infiltrates, with small numbers of lymphocytes. Macrophages had active phagocytosis and showed points of contact with altered muscle cells. Different degrees of matrix expansion were present, with granular and fibrilar deposits and collagen bundles. These alterations subsided by the 64th days. Macrophages seem to be the main immune effector cell in the C. callosus model of infection with T. cruzi. The mechanisms involved in the rapid fibrogenesis and its regression deserve further investigation.