In vitro and in situ activation of the complement system by the fungus Lacazia loboi

Since there are no studies evaluating the participation of the complement system (CS) in Jorge Lobo's disease and its activity on the fungus Lacazia loboi, we carried out the present investigation. Fungal cells with a viability index of 48% were obtained from the footpads of BALB/c mice and incubated with a pool of inactivated serum from patients with the mycosis or with sterile saline for 30 min at 37 ºC. Next, the tubes were incubated for 2 h with a pool of noninactivated AB+ serum, inactivated serum, serum diluted in EGTA-MgCl2, and serum diluted in EDTA. The viability of L. loboi was evaluated and the fungal suspension was cytocentrifuged. The slides were submitted to immunofluorescence staining using human anti-C3 antibody. The results revealed that 98% of the fungi activated the CS by the alternative pathway and no significant difference in L. loboi viability was observed after CS activation. In parallel, frozen histological sections from 11 patients were analyzed regarding the presence of C3 and IgG by immunofluorescence staining. C3 and IgG deposits were observed in the fungal wall of 100% and 91% of the lesions evaluated, respectively. The results suggest that the CS and immunoglobulins may contribute to the defense mechanisms of the host against L. loboi.

Anatomic study of the dorsal arterial system of the hand

Historically, the dorsal arterial system of the hand received less attention than the palmar system. The studies concerning dorsal arterial anatomy present some controversies regarding the origin and presence of the dorsal metacarpal artery branches. Knowledge of the anatomy of dorsal metacarpal arteries is especially applied in the surgical planning for flaps taken from the dorsum of the hand. The purpose of this study is to analyze the arterial anatomy of the dorsum of the hand, compare our observations with those of previous studies from the literature, and therefore to define parameters for surgical planning for flaps supplied by the dorsal metacarpal arteries. METHOD: Twenty-six dissections were performed at the dorsum of the right hand of 26 cadavers by making a distal-based U-shaped incision. After catheterization of the radial artery at the wrist level, a plastic dye solution with low viscosity and quick solidification was injected to allow adequate exposure of even small vessels. The radial artery and its branches, the dorsal arterial arch, the dorsal metacarpal arteries, the distal and proximal communicating branches of the palmar system, and the distal cutaneous branches were carefully dissected and identified. RESULTS: The distal cutaneous branches originating from the dorsal metacarpal arteries were observed in all cases; these were located an average of 1.2 cm proximal from the metacarpophalangeal joint. The first dorsal metacarpal artery presented in 3 different patterns regarding its course: fascial, subfascial, and mixed. The branching pattern of the radial artery at the first intermetacarpal space was its division into 3 branches. We observed the presence of the dorsal arterial arch arising from the radial artery in 100% of the cases. The distance between the dorsal arterial arch and the branching point of the radial artery was an average of 2 cm. The first and second dorsal metacarpal arteries were visualized in all cases. The third and fourth dorsal metacarpal arteries were visualized in 96.2% and 92.3% of cases, respectively. There was proximal and distal communication between the dorsal arterial arch and the palmar system through the communicating branches contributing to the dorsal metacarpal artery formation. CONCLUSION: At the dorsum of the hand there is a rich arterial net that anastomoses with the palmar arterial system. This anatomical characteristic allows the utilization of the dorsal aspect of the hand as potential donor site for cutaneous flaps.

Adsorción física sobre sólidos: aspectos termodinámicos

A thermodynamic formalism based on the Gibbs Dividing Surface (GDS) for the description of a solid-fluid interface is presented, so that the adsorption layer is understand as a phase and the adsorption process as the transference of components between a 3-dimensional phase and a 2-dimensional one. Using a state equation derived from the Henry's Law, we shall show how the Langmuir isotherm is deduced from de Gibbs isotherm. The GDS is useful also for understanding the release of heat by a system as the adsorption occurs.

Fuzzy rule-based system for evaluation of uncertainty transaction in cassava chain

A fuzzy ruled-based system was developed in this study and resulted in an index indicating the level of uncertainty related to commercial transactions between cassava growers and their dealers. The fuzzy system was developed based on Transaction Cost Economics approach. The fuzzy system was developed from input variables regarding information sharing between grower and dealer on “Demand/purchase Forecasting”, “Production Forecasting” and “Production Innovation”. The output variable is the level of uncertainty regarding the transaction between seller and buyer agent, which may serve as a system for detecting inefficiencies. Evidences from 27 cassava growers registered in the Regional Development Offices of Tupa and Assis, São Paulo, Brazil, and 48 of their dealers supported the development of the system. The mathematical model indicated that 55% of the growers present a Very High level of uncertainty, 33% present Medium or High. The others present Low or Very Low level of uncertainty. From the model, simulations of external interferences can be implemented in order to improve the degree of uncertainty and, thus, lower transaction costs.

Echocardiographic Abnormalities and Antiphospholipid Antibodies in Patients with Systemic Lupus Erythematosus

OBJECTIVE: Lupus anticoagulant and anticardiolipin antibodies (aCL) have been associated with thrombosis, recurrent abortion, and thrombocytopenia in patients with systemic lupus erythematosus (SLE), but their relationship with cardiac disease is less clear. The purpose of this study was to evaluate the association between antiphospholipid antibodies (aPL) and echocardiographic abnormalities in patients with SLE. METHODS: A total of 70 consecutive patients and 42 control subjects underwent M-mode, 2-dimensional and Doppler echocardiography and tests for lupus anticoagulant, aCL IgG, IgM, and IgA. Lupus anticoagulant was assayed with the dilute Russell viper venom time, and aCL IgG, IgM, and IgA were measured by an enzyme-linked immunosorbent assay (ELISA). RESULTS: Lupus anticoagulant showed a prevalence of 10%. As a whole, aCL had a prevalence of 44.3% and aPL had a prevalence of 50%. Patients with echocardiographic abnormalities had a prevalence of 54.3% and showed a trend towards an association with aCL IgG (P=0.06). The presence of pulmonary hypertension (PH) was significantly associated with aCL IgG (p=0.02). CONCLUSION: aCL IgG was significantly associated with PH and showed a strong trend towards an association with echocardiographic abnormalities taken together. These findings suggest a role for aCL IgG in the development of lupus cardiovascular disease.

Lipid peroxidation and total radical-trapping potential of the lungs of rats submitted to chronic and sub-chronic stress

Exposure to stress induces a cluster of physiological and behavioral changes in an effort to maintain the homeostasis of the organism. Long-term exposure to stress, however, has detrimental effects on several cell functions such as the impairment of antioxidant defenses leading to oxidative damage. Oxidative stress is a central feature of many diseases. The lungs are particularly susceptible to lesions by free radicals and pulmonary antioxidant defenses are extensively distributed and include both enzymatic and non-enzymatic systems. The aim of the present study was to determine lipid peroxidation and total radical-trapping potential (TRAP) changes in lungs of rats submitted to different models of chronic stress. Adult male Wistar rats weighing 180-230 g were submitted to different stressors (variable stress, N = 7) or repeated restraint stress for 15 (N = 10) or 40 days (N = 6) and compared to control groups (N = 10 each). Lipid peroxidation levels were assessed by thiobarbituric acid reactive substances (TBARS), and TRAP was measured by the decrease in luminescence using the 2-2'-azo-bis(2-amidinopropane)-luminol system. Chronic variable stress induced a 51% increase in oxidative stress in lungs (control group: 0.037 ± 0.002; variable stress: 0.056 ± 0.007, P < 0.01). No difference in TBARS was observed after chronic restraint stress, but a significant 57% increase in TRAP was presented by the group repeatedly restrained for 15 days (control group: 2.48 ± 0.42; stressed: 3.65 ± 0.16, P < 0.05). We conclude that different stressors induce different effects on the oxidative status of the organism.

Proteomic data show an increase in autoantibodies and alpha-fetoprotein and a decrease in apolipoprotein A-II with time in sera from senescence-accelerated mice

We evaluated changes in levels by comparing serum proteins in senescence-accelerated mouse-prone 8 (SAMP8) mice at 2, 6, 12, and 15 months of age (SAMP8-2 m, -6 m, -12 m, -15 m) to age-matched SAM-resistant 1 (SAMR1) mice. Mice were sacrificed, and blood was analyzed by 2-dimensional electrophoresis combined with mass spectrometry. Five protein spots were present in all SAMP8 serum samples, but only appeared in SAMR1 samples at 15 months of age except for spot 3, which also showed a slight expression in SAMR1-12 m sera. Two proteins decreased in the sera from SAMP8-2 m, -6 m, and -12 m mice, and divided into 2 spots each in SAMP8-15 m sera. Thus, the total number of altered spots in SAMP8 sera was 7; of these, 4 were identified as Ig kappa chain V region (M-T413), chain A of an activity suppressing Fab fragment to cytochrome P450 aromatase (32C2_A), alpha-fetoprotein, and apolipoprotein A-II. M-T413 is a monoclonal CD4 antibody, which inhibits T cell proliferation. We found that M-T413 RNA level was significantly enhanced in splenocytes from SAMP8-2 m mice. This agreed with serum M-T413 protein alterations and a strikingly lower blood CD4+ T cell count in SAMP8 mice when compared to the age-matched SAMR1 mice, with the latter negatively correlating with serum M-T413 protein volume. Age-related changes in serum proteins favored an increase in autoantibodies and alpha-fetoprotein and a decrease of apolipoprotein A-II, which occurred in SAMP8 mice at 2 months of age and onwards. These proteins may serve as candidate biomarkers for early aging.

Electrocatalytic oxidation of methanol by the [Ru3O(OAc)6(py)2(CH3OH)]3+cluster: improving the metal-ligand electron transfer by accessing the higher oxidation states of a multicentered system

The [Ru3O(Ac)6(py)2(CH3OH)]+ cluster provides an effective electrocatalytic species for the oxidation of methanol under mild conditions. This complex exhibits characteristic electrochemical waves at -1.02, 0.15 and 1.18 V, associated with the Ru3III,II,II/Ru3III,III,II/Ru 3III,III,III /Ru3IV,III,III successive redox couples, respectively. Above 1.7 V, formation of two RuIV centers enhances the 2-electron oxidation of the methanol ligand yielding formaldehyde, in agreement with the theoretical evolution of the HOMO levels as a function of the oxidation states. This work illustrates an important strategy to improve the efficiency of the oxidation catalysis, by using a multicentered redox catalyst and accessing its multiple higher oxidation states.

Multicellular spheroids of bone marrow stromal cells: a three-dimensional in vitro culture system for the study of hematopoietic cell migration

Cell fate decisions are governed by a complex interplay between cell-autonomous signals and stimuli from the surrounding tissue. In vivo cells are connected to their neighbors and to the extracellular matrix forming a complex three-dimensional (3-D) microenvironment that is not reproduced in conventional in vitro systems. A large body of evidence indicates that mechanical tension applied to the cytoskeleton controls cell proliferation, differentiation and migration, suggesting that 3-D in vitro culture systems that mimic the in vivo situation would reveal biological subtleties. In hematopoietic tissues, the microenvironment plays a crucial role in stem and progenitor cell survival, differentiation, proliferation, and migration. In adults, hematopoiesis takes place inside the bone marrow cavity where hematopoietic cells are intimately associated with a specialized three 3-D scaffold of stromal cell surfaces and extracellular matrix that comprise specific niches. The relationship between hematopoietic cells and their niches is highly dynamic. Under steady-state conditions, hematopoietic cells migrate within the marrow cavity and circulate in the bloodstream. The mechanisms underlying hematopoietic stem/progenitor cell homing and mobilization have been studied in animal models, since conventional two-dimensional (2-D) bone marrow cell cultures do not reproduce the complex 3-D environment. In this review, we will highlight some of the mechanisms controlling hematopoietic cell migration and 3-D culture systems.

Studies on mosquitoes (Diptera: Culicidae) and anthropic environment: 2 - Immature stages research at a rice irrigation system location in South-Eastern Brazil

A relation between a rice irrigation system and mosquito breeding was established in a study undertaken at the Ribeira Valley Experimental Station, from January through December 1992. Flooding favoured Anopheles (Nyssorhynchus) and Culex (Melanoconion) species, while empty paddies condition were propitious to Aedes scapularis and Culex (Culex) species. Compared with a more primitive area of the same region, several species showed high a degree of adaptation to the anthropic environment. Among them, Anopheles albitarsis, a potential malaria vector that breeds in the irrigation system, has shown immature stage production thirteen times higher than at the natural breeding sites. In addition, Ae. scapularis, An. oswaldoi, Cx. bastagarius, and Cx. chidesteri presented high levels of synanthropy.

Central nervous system virion detection in acute measles: histopathological, ultrastructural and pathogenetic aspects

Histopathological and ultrastructural studies of 23 patients who died with clinical diagnosis of measles were carried out. In 12 cases viral nucleocapsids were searched by electron microscopy and detected in 100% of the cases in the lungs and in 50% of the cases in the central nervous system. They were mostly intranuclear. Histopathological changes associated to neurological alterations and the detection of virion are discussed in relation to acute and delayed clinical manifestations.

Comparative analysis of two-dimensional electrophoresis maps (2-DE) of Helicobacter pylori from Brazilian patients with chronic gastritis and duodenal ulcer: a preliminary report

Helicobacter pylori is a bacterium recognized as the major cause of peptic ulcer and chronic gastritis. Recently, a proteome-based approach was developed to investigate pathogenic factors related to H. pylori. In this preliminary study, H. pylori strains were isolated from gastric biopsies of patients with chronic gastritis and duodenal ulcers. A partial proteomic analysis of H. pylori strains was performed by bacterial lyses and proteins were separated by two-dimensional gel electrophoresis (2-DE). A comparative analysis was performed to verify a differential protein expression between these two 2-DE maps. These data should be useful to clarify the role of different proteins related to bacterial pathogenesis. This study will be completed using a larger number of samples and protein identification of H. pylori by MALDI-TOF mass spectrometry.

Isolation of dengue 2 virus from a patient with central nervous system involvement (transverse myelitis)

A dengue fever case is described in a 58-year-old male patient with febrile illness and thrombocytopenia complicated by neurological involvement characterized by transverse myelitis followed by weakness of both legs and flaccid paralysis. Muscle strength was much diminished and bilateral areflexia was observed. Dengue 2 (DEN-2) virus was isolated and the patient sero-converted by hemagglutination-inhibition and IgM-ELISA tests. The RT-PCR test was positive to DEN-2 in acute phase serum and culture supernatant, but negative in the cerebrospinal fluid. After three weeks of hospitalization the patient was discharged. No other infectious agent was detected in the blood and cerebrospinal fluid samples. The patient had full recovery from paralysis six months after the onset of DEN-2 infection.

Performance of the Vitek 2 system software version 5.03 in the bacterial identification and antimicrobial susceptibility test: evaluation study of clinical and reference strains of Gram-positive cocci

Introduction. The genera Enterococcus, Staphylococcus and Streptococcus are recognized as important Gram-positive human pathogens. The aim of this study was to evaluate the performance of Vitek 2 in identifying Gram-positive cocci and their antimicrobial susceptibilities. Methods. One hundred four isolates were analyzed to determine the accuracy of the automated system for identifying the bacteria and their susceptibility to oxacillin and vancomycin. Results. The system correctly identified 77.9% and 97.1% of the isolates at the species and genus levels, respectively. Additionally, 81.8% of the Vitek 2 results agreed with the known antimicrobial susceptibility profiles. Conclusion. Vitek 2 correctly identified the commonly isolated strains; however, the limitations of the method may lead to ambiguous findings.