Impaired macrophage responses may contribute to exacerbation of blood-stage Plasmodium chabaudi chabaudi malaria in interleukin-12-deficient mice.

Aiming to clarify the role of endogenous interleukin-12 (IL-12) in protective immunity against blood stages of Plasmodium chabaudi chabaudi (AS), we evaluated the course of infection in IL-12p40 gene knockout (IL-12p40KO) and wild-type (WT) C57BL/6 mice, focusing (1) on the ability of T cells to develop adequate type 1 responses and (2) on the potentiality of macrophages to respond to parasites, interferon-gamma (IFN-gamma), or both. We observed that IL-12p40KO mice develop significantly higher parasitemias during the acute infection, although mice from both groups clear the parasites within a month and similarly eliminate a secondary challenge. Thus, fully protective immunity to P. c. chabaudi can be generated in the absence of IL-12. However, this cytokine may promote parasite control during the early phase of infection. The increased acute parasitemia of IL-12p40KO mice was associated with both impaired IFN-gamma and nitric oxide (NO) response by spleen cells. Because stimulation with recombinant IFN-gamma (rIFN-gamma) failed to improve the NO response in IL-12p40KO macrophages, we investigated whether these cells have an intrinsic defect. Analysis of peritoneal macrophages revealed that IL-12p40KO cells produce higher levels of transforming growth factor-beta1 (TGF-beta1) compared with WT cells and respond to infected erythrocytes or rIFN-gamma by releasing little NO. Moreover, IL-12p40KO macrophages had a severely impaired ability to internalize opsonized infected erythrocytes, suggesting that the low effector profile assumed by these cells may compromise antibody-mediated immunity. Taken together, our results support the idea that the absence of IL-12p40 not only affects IFN-gamma production but also has deep consequences in macrophage effector functions that may contribute to exacerbation of the early phase of P. c. chabaudi malaria.     

Solitary fibrous tumour of the thyroid: Clinicopathological,immunohistochemical and ultrastructural study of three cases

We describe three cases of solitary fibrous tumour (SFT) arising from thyroid stroma. Grossly, the tumours were clearly delimited but only partly encapsulated. The following histomorphological growth patterns were observed: bundles of cells in storiform configuration; non-structured bundles; prevalence of fibrous matrix; highly cellular, non-structured; prevalence of loose, non-structured extracellular substance; cellular proliferation and vascular spaces in a haemangiopericytic configuration and a lipomatous component. Immunohistochemical investigation demonstrated intense, diffuse vimentin positivity and focal, less intense actin positivity in all three cases. At electron microscopy we observed a primitive cell of mesenchymal type, with cytoplasm poor in organelles and rich in filaments; this cell sometimes presented differentiation characteristics. SFT is at present the most correct term for the lesions presented here despite some morphological characteristics which differ from cases reported in the literature.     

Sensitive and viable identification of antigen-specific CD8+ T cells by a flow cytometric assay for degranulation

Flow cytometric detection of antigen-specific CD8+ T cells has previously been limited to MHC-class I tetramer staining or intracellular cytokine production, neither of which measure the cytolytic potential of these cells. Here we present a novel technique to enumerate antigen-specific CD8+ T cells using a marker expressed on the cell surface following activation induced degranulation, a necessary precursor of cytolysis. This assay measures the exposure of CD107a and b, present in the membrane of cytotoxic granules, onto the cell surface as a result of degranulation. Acquisition of cell surface CD107a and b is associated with loss of intracellular perforin and is inhibited by colchicine, indicating that exposure of CD107a and b to the cell surface is dependent on degranulation. CD107a and b are expressed on the cell surface of CD8+ T cells following activation with cognate peptide, concordant with production of intracellular IFNgamma. Finally, CD107-expressing CD8+ T cells are shown to mediate cytolytic activity in an antigen-specific manner. Measurement of CD107a and b expression can also be combined with MHC-class I tetramer labeling and intracellular cytokine staining to provide a more complete assessment of the functionality of CD8+T cells expressing cognate T cell receptors (TCR).     

Immunohistochemical localization of laminin, collagen IV and fibronectin in dysplasias and neoplasms of the cervix uteri

The distribution of intrinsic components (Laminin and Type IV Collagen) and extrinsic component (Fibronectin) of the Basement Membrane (BM) has been studied in normal uterine cervix (16 cases), in cervical dysplasia (14 cases) and in invasive carcinoma (45 cases). We found that BM staining for Laminin and Type IV collagen is linear and continuous underlying normal and dysplastic epithelium (CIN 1-CIN 2), it shows minor breaks in continuity and alterations of linearity in situ carcinomas (CIN 3), and it disappears in microinvasive areas. In well differentiated invasive carcinomas only focal disruptions of BM around neoplastic nests is noted; in contrast, in moderately and poorly differentiated neoplasias, is found a progressive reduction and loss of staining for Laminin and Type IV Collagen. The results of this study suggest that the distribution patterns of BM intrinsic components are in relation to the histological grade of cervical neoplasias and their invasion ability. On the contrary Fibronectin doesn't show any distribution pattern related to the grade of cervical neoplasias, its immunostaining increased with the rise of both connective tissue stroma production and of vascularity.     

Kinematic and dynamic analysis of running under conditions of variable gravity

A new training system was designed and realised by the engineer G. Scuderi: a centrifugal track for runners. The principal advantage of this track is to increase the forces on athlete during the run with an effect very similar to that of an "artificial gravity", so the athlete can develop more muscle power. A multibody numerical model of a runner was developed to analyse the behaviour of the athlete on the centrifugal track. The multibody model was calibrated by experimental analysis; in fact, the joint angles were measured by a digital image processing system and introduced as input in the numerical simulation. The numerical results obtained are the values of many kinematic and dynamic variables, in particular the ground reaction force and the moments in the hip, knee, and ankle joints. A comparison between the normal running and that on the centrifugal track was carried out, demonstrating the validity of training on the latter. The results of the numerical simulation confirm that the power developed during running on the track, and the corresponding work performed by the joints, is considerably greater than that found during normal running.     

Effect of the Addition of Vancomycin on the Performance of an Automated Nonradioactive System for Detection of Mycobacteria

 A recently developed automated, nonradioactive system for the detection of mycobacteria (MB/BacT; Organon Teknika, Belgium) has provided good results, but the contamination rate was found to be higher than that obtained with the radiometric Bactec 460 system (Becton Dickinson, USA). In the present study, the effects of adding vancomycin (1 μg/ml) to the antibiotic mixture of the nonradioactive system were evaluated, and the performance of the system with versus without vancomycin was compared. Three hundred sputum samples were tested, using the radiometric system as the reference method. Mycobacteria were isolated from 47 (15.7%) samples. The nonradioactive system with and without vancomycin detected 42 and 43 strains, respectively; the time to detection was 1 day shorter with the medium without vancomycin (15.7 days vs. 14.3 days). The radiometric system detected 42 strains of mycobacteria in a mean detection time of 13.6 days. Contamination rates with the nonradioactive system were 6.7% in the medium without vancomycin and 2.7% in the medium with vancomycin. The latter figure was approximately the same as the contamination rate found with the radiometric system (2.3%). Our data suggest that the addition of vancomycin considerably reduces the number of contaminants in the MB/BacT medium without affecting the performance of the system.     

Modulation of the constitutive or cytokine-induced bronchial epithelial cell functions in vitro by fluticasone propionate

When exposed to proinflammatory mediators, human bronchial epithelial cells (HBECs) upregulate the 'constitutive' adhesion molecule expression and cytokine/chemokine release. We tested whether and to what extent the inhibitory effect of fluticasone propionate on HBECs could involve the 'constitutive' and 'cytokine-induced' proinflammatory functions. Stimulation of the HBECs with interleukin (IL)-4 plus tumour necrosis factor (TNF)-alpha was more effective in upregulating intercellular adhesion molecule (ICAM)-1 ( approximately 2.2-fold increase) than vascular adhesion molecule (VCAM)-1 ( approximately 1.6-fold increase) expression (P<0.05) and in increasing the release of 'regulated on activation normal T cell expressed' (RANTES, 5.7-fold increase) than of IL-8 (3.5-fold increase) and granulocyte macrophage-colony stimulating factor (GM-CSF, 2.8-fold increase), (P<0.01). Fluticasone propionate, at the two concentrations tested (10 and 100 nM), was more effective in inhibiting the 'IL-4 plus TNF-alpha-induced' ICAM-1 expression than VCAM-1 expression (P<0.05) and in downregulating RANTES than IL-8 or GM-CSF secretion (P<0.05). The degree of inhibition demonstrated by fluticasone propionate appeared to be related to the degree of cell activation. In addition, for both adhesion molecules, the effect of fluticasone propionate at both concentrations tested appeared to be related to a complete inhibition of 'IL-4 plus TNF-alpha-induced' expression with no involvement of the 'constitutive' expression. Slightly different results were observed for cytokine/chemokine release. Indeed, evaluating RANTES, a complete inhibition of the 'IL-4 plus TNF-alpha-induced' release with a partial inhibition also of the 'constitutive' release at both concentrations of the drug tested was found, whereas for GM-CSF and IL-8, only a partial inhibition of the 'IL-4 plus TNF-alpha-induced' release in the presence of fluticasone propionate 10 and 100 nM. Thus, HBECs can constitutively or upon activation express adhesion molecules and secrete proinflammatory proteins at various levels and the different ability of fluticasone propionate to modulate the HBEC functions appears to be mostly related to the different inhibition of the various 'IL-4 plus TNF-alpha-induced' responses.     

Changes in bone turnover during tibolone treatment

OBJECTIVES: An open study was carried out to evaluate changes in bone remodeling markers such as N-telopeptide (NTx), tartrate-resistant acid phosphatase (TRAP), total alkaline phosphatase (TAP), and bone alkaline phosphatase (BAP) during a 1-year continuous tibolone treatment in postmenopausal women. MATERIAL AND METHODS: Thirty-six postmenopausal women were recruited for receiving tibolone 2.5 mg per day for 1 year. Densitometry and determination of biochemical markers of bone metabolism in serum and urine were performed at 1, 3, 6, and 12 months. RESULTS: Comparing baseline with 12 month's values, BAP and all resorption markers decreased significantly. NTx began to decrease since the initiation of the treatment (baseline: 74.4 +/- 5.3; 1 month: 57.5 +/- 4.2; 12 months: 36.6 +/- 2.8). BAP increased at the first month (baseline: 37.3 +/- 2.1; 1 month: 42.6 +/- 3.0) but diminished in the following months (12 months: 23.1 +/- 1.5). TAP started to decrease significantly only after 6 months of treatment (baseline: 37.3 +/- 2.1; 12 months: 31.4 +/- 2.3) and TRAP after 3 months (baseline: 9.8 +/- 0.4; 6 months: 9.1 +/- 0.5; 12 months: 8.2 +/- 0.4). Normal bone mineral density at distal and ultradistal forearm was maintained during the 1-year treatment (baseline: 0.42 +/- 0.01; 12 months: 0.42 +/- 0.01 and baseline: 0.33 +/- 0.01; 12 months: 0.33 +/- 0.01, respectively). CONCLUSION: The use of tibolone 2.5 mg per day diminished progressively and significantly bone resorption and formation markers during 1-year treatment period.