Mycoplasma pneumoniae and Chlamydia pneumoniae in calcified nodules of aortic stenotic valves

Aortic Valve Stenosis (AVS) has been explained as an atherosclerotic process of the valve as they often exhibit inflammatory changes with infiltration of macrophages, T lymphocytes and lipid infiltration. The present study investigated whether the bacteria Chlamydia pneumoniae (CP) and Mycoplasma pneumoniae (MP), detected previously in atherosclerotic plaques, are also present in AVS. Ten valves surgically removed from patients with AVS were analyzed by immunohistochemistry, in situ hybridization, and electron microscopy. The mean and standard deviation of the percentage areas occupied by CP antigens and MP - DNA were respectively 6.21 +/- 5.41 and 2.27 +/- 2.06 in calcified foci; 2.8 +/- 3.33 and 1.78+/- 3.63 in surrounding fibrotic areas, and 0.21 +/- 0.17 and 0.12 +/- 0.13 in less injured parts of the valve. There was higher amount of CP and MP in the calcified foci and in the surrounded fibrosis than in more preserved valvular regions. In conclusion, the fact that there were greater amounts of CP and MP in calcification foci of AVS favors the hypothesis that AS is not an inevitable degenerative process due to aging, but rather that it may be a response to the presence of these bacteria, similarly to the morphology detected in atherosclerosis damage.

Histoplasmosis presenting with multiple pulmonary nodules. A case mimicking radiological features of pulmonary metastasis

We present a case of histoplasmosis with multiple pulmonary nodules in a patient with a history of melanoma. This case closely simulated malignancy, including the presence of feeding vessel sign, which occurs in pulmonary metastasis. We emphasize the need to be aware of this infection in areas where histoplasmosis is endemic.

MULTIPLE PULMONARY NODULES CAUSED BY Corynebacterium striatum IN AN IMMUNOCOMPETENT PATIENT

Nondiphtherial corynebacteria are ubiquitous in nature and commonly colonize the skin and mucous membranes of humans, however they rarely account for clinical infection. We present the first reported case of multiple pulmonary nodules caused by Corynebacterium striatum. The infection occurred in a 72-year-old immunocompetent female, and the diagnosis was obtained by Gram's stain and culture of lung biopsy. C. striatumshould be recognized as a potential pathogen in both immunocompromised and normal hosts in the appropriate circumstances.

Macrofilaricidal effects of chloroquine on adult Onchocerca volvulus by local infiltration of palpable onchocercal nodules

The macrofilaricidal effects of local infiltration of high concentrations of chloroquine into the capsule of onchocercal nodules on adult worms of Onchocerca volvulus was determined. Six weeks post infiltration, histological examination of single nodules showed all adult worms to be dead. With nodule conglomerates, there was localized action of chloroquine only on the adult worms in the infiltrated nodule, with no diffusion of the drug to adjacent nodules. Chloroquine infiltration of young, recently formed nodules to reduce the adult worm load of infected individuals may be an alternative method to costly nodulectomy.

Multiple lymphoid nodules in bone marrow biopsy in immunocompetent patient with cytomegalovirus infection: an immunohistochemical analysis

In Brazil, a high prevalence of cytomegalovirus (CMV) infection has been documented. In immunocompetent adults CMV infection is usually asymptomatic and therefore morphologic and immunophenotypic bone marrow changes have rarely been described. The authors report the case of a previously healthy patient who developed fever of undetermined origin. The diagnosis of acute CMV infection was based on serological testing. A computed tomographic scan showed mediastinal lymphadenopathy. A bone marrow biopsy revealed a hypercellular haematopoiesis with eosinophilia and large mixed T- and B-cell lymphoid aggregates. In spite of bcl-2 positivity, their reactive nature was demonstrated. Polymerase chain reaction (PCR) and immunohistochemistry were unable to detect CMV-DNA in paraffin-embedded bone marrow sections. Much like in other systemic disorders, the lymphoid nodules in this case seemed to be caused by immunological mechanisms, possibly due to cytokines released in response to the systemic infectious process.

Testicular schistosomiasis as differential diagnosis for testicular nodules: a case report

AbstractDespite its infrequent occurrence, testicular schistosomiasis forming pseudo-tumors can be considered in the differential diagnosis of testicular tumors, especially in areas where the parasitic disease is endemic. In this report, we present a case of testicular schistosomiasis caused by Schistosoma mansoni and mimicking a testicular neoplasm. We describe the patterns of a testicular nodule on ultrasonography and magnetic resonance images in a 46-year-old man. The nodule was removed after a pre-operative diagnosis of a non-malignant lesion. Histology demonstrated granulomas with epithelioid macrophages and eosinophils around S. mansoni eggs within a fibrous tissue that formed a nodular structure.

Intestinal fibrovascular nodules caused by Schistosoma mansoni infection in Calomys callosus Rengger, 1830 (Rodentia: Cricetidae): a model of concomitant fibrosis and angiogenesis

Human schistosomiasis develops extensive and dense fibrosis in portal space, together with congested new blood vessels. This study demonstrates that Calomys callosus infected with Schistosoma mansoni also develops fibrovascular lesions, which are found in intestinal subserosa. Animals were percutaneously infected with 70 cercariae and necropsied at 42, 45, 55, 80, 90 and 160 days after infection. Intestinal sections were stained for brightfield, polarization microscopy, confocal laser scanning, transmission and scanning electron microscopies. Immunohistological analysis was also performed and some nodules were aseptically collected for cell culture. Numerous intestinal nodules, appearing from 55 up to 160 days after infection, were localized at the interface between external muscular layer and intestinal serosa, consisting of fibrovascular tissue forming a shell about central granuloma(s). Intranodular new vessels were derived from the vasculature of the external vascular layer and were positive for laminin, chondroitin-sulfate, smooth muscle alpha-actin and FVIII-RA. Fibroblastic cells and extracellular matrix components (collagens I, III and VI, fibronectin and tenascin) comprised the stroma. Intermixed with the fibroblasts and vessels there were variable number of eosinophils, macrophages and haemorrhagic foci. In conclusion, the nodules constitute an excellent and accessible model to study fibrogenesis and angiogenesis, dependent on S. mansoni eggs. The fibrogenic activity is fibroblastic and not myofibroblastic-dependent. The angiogenesis is so prominent that causes haemorrhagic ascites.

Diversity and nitrogen fixation efficiency of rhizobia isolated from nodules of Centrolobium paraense

The objective of this work was to isolate and characterize rhizobia from nodules of Centrolobium paraense and to evaluate their symbiotic efficiency. Soil samples collected from four sites of the Roraima Cerrado, Brazil, were used to cultivate C. paraense in order to obtain nodules. Isolates (178) were obtained from 334 nodules after cultivation on medium 79. Twenty-five isolates belonging to six morphological groups were authenticated using Vigna unguiculata and they were characterized by 16S rRNA. Isolates identified as Bradyrhizobium were further characterized using rpoB gene sequencing. A greenhouse experiment was carried out with C. paraense to test the 18 authenticated isolates. Approximately 90% of the isolates grew slowly in medium 79. The 16S rRNA analysis showed that 14 authenticated isolates belong to the genus Bradyrhizobium, and rpoB indicated they constitute different groups compared to previously described species. Only four of the 11 fast-growing isolates nodulated V. unguiculata, two of which belong to Rhizobium, and two to Pleomorphomonas, which was not previously reported as a nodulating genus. The Bradyrhizobium isolates ERR 326, ERR 399, and ERR 435 had the highest symbiotic efficiency on C. paraense and showed a contribution similar to the nitrogen treatment. Centrolobium paraense is able to nodulate with different rhizobium species, some of which have not yet been described.

Ultrasound-guided fine-needle aspiration of thyroid nodules: assessment of the ideal number of punctures

OBJECTIVE: To determine the number of punctures in fine-needle aspiration biopsies required for a safe cytological analysis of thyroid nodules. MATERIALS AND METHODS: Cross-sectional study with focus on diagnosis. The study population included 94 patients. RESULTS: The mean age of the patients participating in the study was 52 years (standard-deviation = 13.7) and 90.4% of them were women. Considering each puncture as an independent event, the first puncture has showed conclusive results in 78.7% of cases, the second, in 81.6%, and the third, in 71.8% of cases. With a view to the increasing chance of a conclusive diagnosis at each new puncture, two punctures have showed conclusive results in 89.5% of cases, and three punctures, in 90.6% of cases with at least one conclusive result. CONCLUSION: Two punctures in fine-needle aspiration biopsies of thyroid nodules have lead to diagnosis in 89.5% of cases in the study sample, suggesting that there is no need for multiple punctures to safely obtain the diagnosis of thyroid nodules.

Atlantic Forest succession over calcareous soil, Parque Estadual Turístico do Alto Ribeira - PETAR, SP

The forest succession after abandonment of slash-and-burn agriculture over calcareous soil in Brazilian Atlantic Forest was assessed. This is one of the world's most threatened Biome, with only 8% remaining. The study area is located over calcareous soil inside the Alto Ribeira Touristic State Park (PETAR), southeast Brazil. The phytossociological survey showed a successional pattern dominated by species of Leguminosae, especially Piptadenia gonoacantha (Mart.) J.F. Macbr. This species occurs in calcareous soils as a substitute of Tibouchina pulchra (Cham.) Cogn. (Melastomataceae) that is the most usual dominant tree species in early succession over acidic soil, which is the most common situation in this Biome. These results are important for a better understanding of Neotropical forest biodiversity and characterize a unique genetic bank in this highly endangered Biome. They are also decisive to support actions regarding rehabilitation of degraded lands and a potential tool for Neotropical forest sustainable management, both inside and around the conservation unit.