New Features to Look at Natural Phenomena

Proceeding of the 3rd International Conference on Fractional Systems and Signals, at Ghent, Belgium

Effect of sialic acid loss on dendritic cell maturation

Sialic acids are key structural determinants and contribute to the functionality of a number of immune cell receptors. Previously, we demonstrated that differentiation of human dendritic cells (DCs) is accompanied by an increased expression of sialylated cell surface structures, putatively through the activity of the ST3Gal.I and ST6Gal.I sialyltransferases. Furthermore, DC endocytosis was reduced upon removal of the cell surface sialic acid residues by neuraminidase. In the present work, we evaluate the contribution of the sialic acid modifications in DC maturation. We demonstrate that neuraminidase-treated human DCs have increased expression of major histocompatibility complex (MHC) and costimulatory molecules, increased gene expression of specific cytokines and induce a higher proliferative response of T lymphocytes. Together, the data suggest that clearance of cell surface sialic acids contributes to the development of a T helper type 1 proinflammatory response. This postulate is supported by mouse models, where elevated MHC class II and increased maturation of specific DC subsets were observed in DCs harvested from ST3Gal.I(-/-) and ST6Gal.I(-/-) mice. Moreover, important qualitative differences, particularly in the extent of reduced endocytosis and in the peripheral distribution of DC subsets, existed between the ST3Gal.I(-/-) and ST6Gal.I(-/-) strains. Together, the data strongly suggest not only a role of cell surface sialic acid modifications in maturation and functionality of DCs, but also that the sialic acid linkages created by different sialyltransferases are functionally distinct. Consequently, with particular relevance to DC-based therapies, cell surface sialylation, mediated by individual sialyltransferases, can influence the immunogenicity of DCs upon antigen loading.

Cryptococcus gattii fungemia: report of a case with lung and brain lesions mimicking radiological features of malignancy

A 64-year-old apparently immunocompetent white man developed lung and brain lesions of disseminated cryptococcosis. The radiologic features mimicked those of lung cancer metastatic to the central nervous system. C. gattii was recovered from cultures of bronchoalveolar lavage fluid, brain biopsy, and blood. The same fungus was recovered from pulmonary and brain specimens at autopsy. Serum and cerebrospinal fluid cryptococcal antigen tests were diagnostic in our case and should be included in the diagnostic evaluation of unexplained pulmonary and cerebral lesions. A literature search showed few reports of fungemia by this species of Cryptococcus, contrasting to C. neoformans.

Epidemiologic features of HIV infection in three municipalities of inner Rio de Janeiro State, Brazil

In Brazil relatively little attention is being paid to the study of the features of the spread of the AIDS epidemic towards small cities and rural areas. We report a descriptive study on the epidemiological features of HIV infection among 208 adult patients seen between July 1999 and May 2006 in the municipal HIV/AIDS Programs of three cities of inner Rio de Janeiro State: Saquarema, Santo Antonio de Pádua and Miracema. A portrait of a heterosexual epidemic emerged, with an overall male to female ratio of 1.1. More than 90% were residents of the studied cities, demonstrating a local demand for HIV-related assistance and the importance of municipal HIV/AIDS Programs. Past or current use of snorted cocaine was reported by a quarter of the patients. Older age and male gender were independent predictors of having a diagnosis of AIDS at presentation. The latter is in accordance with a more recent wave of epidemic spread towards female gender. A low frequency of male circumcision, an important determinant of heterosexual HIV transmission, was recorded. Almost 60% of the patients first presented in advanced stages of HIV infection, suggesting the existence of a large pool of undiagnosed cases in the community.

Clinical and epidemiological features of 123 cases of cryptococcosis in Mato Grosso do Sul, Brazil

To identify the clinical and epidemiological profile of cryptococcosis diagnosed at the University Hospital of the Federal University of Mato Grosso do Sul, Brazil, medical records of 123 patients admitted from January 1995 to December 2005 were analyzed. One hundred and four cases (84.5%) had HIV infection, six (4.9%) had other predisposing conditions and 13 (10.6%) were immunocompetent. Male patients predominated (68.3%) and their age ranged from 19 to 69 years (mean: 35.9). Most patients (73.2%) were born and lived lifelong in the state of Mato Grosso do Sul. Involvement of the central nervous system occurred in 103 patients (83.7%) and headache and vomiting were the most frequent symptoms. In 77 cases it was possible to identify the Cryptococcus species: 69 (89.6%) C. neoformans and eight (10.4%) C. gattii. Amphotericin B was the drug of choice for treatment (106/123), followed by fluconazole in 60% of cases. The overall lethality rate was 49.6%, being 51% among the HIV infected patients and 41.2% among the non-HIV infected (p > 0.05). Although cryptococcosis exhibited in our region a similar behavior to that described in the literature, the detection of an important rate of immunocompetent individuals and five C. gattii cryptococcosis in HIV-infected patients is noteworthy.

Case for Diagnosis

Blastic plasmacytoid dendritic cell tumor is a rare, highly aggressive systemic neoplasm for which effective therapies have not yet been established. We describe a 73-year-old man with multiple nodules and patches emerging on the trunk and limbs. Lesional skin biopsy revealed a plasmacytoid dendritic cell tumor with dense dermal infiltrate of tumor cells with blastoid features. No apparent systemic involvement was identified in the initial stage. The patient was treated with prednisone daily, with notorious improvement of the skin lesions, although no complete remission was obtained. During the six-month follow-up period, no disease progression was documented, but fatal systemic progression occurred after that period of time.

Infection and immune-mediated meningococcal-associated arthritis: combination features in the same patient

We present a case of a 16-year-old male patient with sudden-onset, rash, arthritis and meningitis by Neisseria meningitidis one week after an acute upper respiratory infection. On the 10th day of treatment followed by neurological and arthritis clinical improvement, he presented once again a tender and swollen left knee with a moderate effusion, and active and passive range of motion was severely limited secondary to pain, and when he was submitted to surgical drainage and synovial fluid analysis he showed inflammatory characteristics. A non-steroidal anti-inflammatory drug was taken for five days with complete improvement of symptoms. The case is notable for its combination of features of septic and immune-mediated arthritis, which has rarely been reported in the same patient.

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.

Transplant Glomerulopathy: Clinico-Pathologic Features

Transplant glomerulopathy is a sign of chronic kidney allograft damage. It has a distinct morphology and is associated with poor allograft survival. We aimed to assess the prevalence and clinic-pathologic features of transplant glomerulopathy, as well as determine the functional and histological implications of its severity. We performed a single-centre retrospective observational study during an eight-year period. Kidney allograft biopsies were diagnosed and scored according to the Banff classification, coupled with immunofluorescence studies. The epidemiology, clinical presentation, outcomes (patient and graft survival) and anti-HLA alloantibodies were evaluated. Transplant glomerulopathy was diagnosed in 60 kidney transplant biopsies performed for clinical reasons in 49 patients with ABO compatible renal transplant and a negative T-cell complement dependent cytotoxicity crossmatch at transplantation. The estimated prevalence of transplant glomerulopathy was 7.4% and its cumulative prevalence increased over time. C4d staining in peritubular capillaries (27.6%) was lower than the frequency of anti-HLA antibodies (72.5%), the majority against both classes I and II. Transplant glomerulopathy was associated with both acute (mainly glomerulitis and peritubular capillaritis) and chronic histologic abnormalities. At diagnosis, 30% had mild, 23.3% moderate and 46.7% severe transplant glomerulopathy. The severity of transplant glomerulopathy was associated with the severity of interstitial fibrosis. Other histological features, as well as clinical manifestations and graft survival, were unrelated to transplant glomerulopathy severity.

Blastic Plasmacytoid Dendritic Cell Neoplasm

Blastic plasmacytoid dendritic cell neoplasm is a rare and aggressive hematodermic neoplasia with frequent cutaneous involvement and leukemic dissemination. We report the case of a 76-year-old man with a 2 month history of violaceous nodules and a tumor with stony consistency, located on the head, and mandibular, cervical and supraclavicular lymphadenopathies. Multiple thoracic and abdominal adenopathies were identified on computerized tomography. Flow cytometry analysis of the skin, lymph node and bone marrow biopsies demonstrated the presence of plasmocytoid dendritic cell neoplastic precursor cells (CD4+, CD45+, CD56+ and CD123+ phenotype). After initial clinical and laboratorial complete remission with chemotherapy, the patient died due to relapse of the disease associated with the appearance of a cervical mass with medullary compromise.

PREVALENCE OF DRUG RESISTANCE AND VIRULENCE FEATURES IN Salmonella spp. ISOLATED FROM FOODS ASSOCIATED OR NOT WITH SALMONELLOSIS IN BRAZIL

Salmonella is the most common etiological agent of cases and outbreaks of foodborne diarrheal illnesses. The emergence and spread of Salmonella spp., which has become multi-drug resistant and potentially more pathogenic, have increased the concern with this pathogen. In this study, 237 Salmonella spp., associated or not with foodborne salmonellosis in Brazil, belonging mainly to serotype Enteritidis, were tested for antimicrobial susceptibility and the presence of the virulence genes spvC, invA, sefA and pefA. Of the isolates, 46.8% were sensitive to all antimicrobials and 51.9% were resistant to at least one antimicrobial agent. Resistance to more than one antimicrobial agent was observed in 10.5% of the strains. The highest rates of resistance were observed for streptomycin (35.9%) and nalidixic acid (16.9%). No strain was resistant to cefoxitin, cephalothin, cefotaxime, amikacin, ciprofloxacin and imipenem. The invA gene was detected in all strains. Genes spvC and pefA were found in 48.1% and 44.3% of strains, respectively. The gene sefA was detected in 31.6% of the strains and only among S. Enteritidis. Resistance and virulence determinants were detected in Salmonella strains belonging to several serotypes. The high rates of antibiotic-resistance in strains isolated from poultry products demonstrate the potential risk associated with the consumption of these products and the need to ensure good food hygiene practices from farm to table to reduce the spread of pathogens relevant to public health.

LEPROSY NEPHROPATHY: A REVIEW OF CLINICAL AND HISTOPATHOLOGICAL FEATURES

Leprosy is a chronic disease caused by Mycobacterium leprae, highly incapacitating, and with systemic involvement in some cases. Renal involvement has been reported in all forms of the disease, and it is more frequent in multibacillary forms. The clinical presentation is variable and is determined by the host immunologic system reaction to the bacilli. During the course of the disease there are the so called reactional states, in which the immune system reacts against the bacilli, exacerbating the clinical manifestations. Different renal lesions have been described in leprosy, including acute and chronic glomerulonephritis, interstitial nephritis, secondary amyloidosis and pyelonephritis. The exact mechanism that leads to glomerulonephritis in leprosy is not completely understood. Leprosy treatment includes rifampicin, dapsone and clofazimine. Prednisone and non-steroidal anti-inflammatory drugs may be used to control acute immunological episodes.

Neuropsychiatric Features of a Cohort of Patients with Systemic Lupus Erythematosus

In order to establish if neuropsychiatric systemic lupus erythematosus (NPSLE) can be identified by any characteristic other than those used to diagnose the neuropsychiatric (NP) disease itself, we retrospectively reviewed 98 systemic lupus erythematosus (SLE) patients followed over a mean period of 10 years. NPSLE was identified in 22 patients. Stroke and generalized seizures were the most frequent NP manifestations. The NPSLE and non-NPSLE groups were similar with regard to demographic characteristics, ACR criteria, serum autoantibodies, and frequency of hypertension and hypercholesterolemia. Of note, compared to the non-NPSLE group, NPSLE was associated with a higher frequency of smoking (78 versus 26%), organ damage (73 versus 34%), and cumulative mortality rate (14 versus 7%). The series of patients was further analysed according to the presence of antiphospholipid syndrome (APS). Significantly, the interval between the onset of NP disease and SLE diagnosis was shorter in the APS(-) (0.3 ± 1 years) than in the APS(+) (5 ± 7 years) groups. Recurrence and/or persistence of NP events were only documented in the APS(-) group. Overall cumulative mortality was highest in NPSLE and in APS(+) patients with inadequate anticoagulation control, identifying an aspect that requires improved vigilance and the development of novel therapeutic modalities.

Radiographic features of pulmonary tuberculosis in patients infected by HIV: is there an objective indicator of co-infection?

This study aimed to compare the radiographic characteristics of patients with pulmonary tuberculosis (TB) and human immunodeficiency virus (HIV) infection with those of HIV-negative patients. In all, 275 TB patients attending the outpatients clinics at the University Hospital/UFPE, were studied from January 1997 to March 1999. Thirty nine (14.2%) of them were HIV+, with a higher frequency of males in this group (p=0.044). Seventy-five percent of the HIV+ patients and 19% of the HIV- had a negative tuberculin test (PPD) (p < 0.001). The proportion of positive sputum smears in the two groups was similar. The radiological finding most strongly associated with co-infection was absence of cavitation (p < 0.001). It may therefore be concluded that the lack of cavitation in patients with pulmonary TB may be considered a useful indicator of the need to investigate HIV infection. This approach could contribute to increasing the effectiveness of local health services, by offering appropriate treatment to co-infected patients.

HTLV-I associated myelopathy in the northern region of Brazil (Belém-Pará): serological and clinical features of three cases

Three patients (males, black, ages 37, 40 and 57) attended a university clinic with a progressive paraparesis of obscure origin. One patient who referred disease duration of more than 16 years, showed diminished deep reflexes, bilateral Babinski's sign, diminished sensation of vibration, abnormal bladder function and back pain. The other two patients (with one and six years of disease duration) complained of weakness in one leg, increased deep reflexes and back pain. Babinski's sign and bladder disturbance were also present in the patient with six years of disease. Blood samples tested by an enzyme immune assay and a discriminatory Western blot were positive for HTLV-I. The familial analysis of one patient showed a possible pattern of sexual and vertical transmission of the virus. To the best of our knowledge, these are the first cases of a proven association between HTLV-I and TSP/HAM in Belem, Para, and emphasize the need to actively look for cases of neurological disease associated to the virus.