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A Tazi

Publications and source records attributed to A Tazi.

At least 19 recordsLinked to original sources
PubMed2006

Characterisation of dendritic cell subsets in lung cancer micro-environments.

The aim of the current study was to seek evidence for a correlation between mediators present in lung cancer micro-environments and subsets of dendritic cells (DCs) infiltrating these tumours. Immunohistochemistry and recently available antibodies were used to define the phenotype of DCs present in surgical biopsies from 12 patients with lung carcinomas, and the local expression of chemokines potentially involved in the recruitment of these cells was evaluated, both at mRNA and protein levels. Real-time PCR was used to analyse the expression of mRNA coding for cytokines known to influence the maturation of DCs in vitro. Different subsets of myeloid DCs were present in lung cancers, but no plasmocytoid DCs were identified. Both Langerhans cells and CD1a+/Langerin cells were interspersed among tumour cells, in numbers that were correlated to the amounts of CC chemokine ligand 20 produced in these tumours. In most specimens, DC-specific intercellular adhesion molecule-grabbing nonintegrin-positive DCs were also present at the periphery of the tumour beds. No DC-lysosomal associated membrane protein-positive DCs were identified and CD83+ DCs were rarely present in the tumour stroma. All tumours expressed interleukin (IL)-10, transforming growth factor-beta and vascular endothelial growth factor, whereas IL-12 was virtually absent. Thus, various types of dendritic cells infiltrate lung carcinomas and display an immature phenotype, presumably because of the inhibitory cytokine micro-environment.

Adenocarcinoma↗
PubMed2006

[Evaluation of the iliac crest as anatomic landmark for spinal anaesthesia in pregnant women].

OBJECTIVE: Estimate the relevance of the Tuffier line, which connects both iliac crests, in analyzing the location of the puncture point for spinal anaesthesia for pregnant women. STUDY DESIGN: Prospective. PATIENTS AND METHODS: The age, weight, height, body mass index (BMI) and uterine height, (HU) of 121 patients admitted in the delivery room in July 2005, were recorded. The intersection point of the Tuffier line with the rachis was recorded in seating and sleeping positions. The corresponding vertebral level was verified by counting spiny apophyses from C7. RESULTS: The Tuffier line crossed the spine at the expected level for 29.7% of the patients. The intersection point was below the expected in 6.6% of the cases and above in 63.7% of the cases. Only the weight and the BMI were significantly connected with stronger probability of error (p=0.001). CONCLUSION: The error level with this method is important and comparable to error level in the series published in patients who are not pregnant woman. The main risk is the spinal injury, since the level of ending of the spinal cord is variable. It seems safe to use another method of location, especially with patients experiencing excessive weight.

Adult↗
PubMed2006

Adult pulmonary Langerhans' cell histiocytosis.

Adult pulmonary Langerhans' cell histiocytosis is a rare disorder of unknown aetiology that occurs predominantly in young smokers, with an incidence peak at 20-40 yrs of age. In adults, pulmonary involvement with Langerhans' cell histiocytosis usually occurs as a single-system disease and is characterised by focal Langerhans' cell granulomas infiltrating and destroying distal bronchioles. High-resolution computed tomography (HRCT) of the chest is essential to the diagnosis, typically showing a combination of nodules, cavitated nodules, and thick- and thin-walled cysts. A high macrophage count in bronchoalveolar lavage (BAL) fluid is a common but nonspecific finding that merely reflects exposure to tobacco smoke. BAL is useful for eliminating infections and the other infiltrating lung disorders that can be seen in young adults. Langerhans' cells can be identified in BAL fluid, but, in contrast to what was initially hoped, this test shows a very low sensitivity and is rarely useful in the diagnosis of the disease. The definite diagnosis of pulmonary Langerhans' cell histiocytosis requires identification of Langerhans' cell granulomas, which is usually achieved by surgical lung biopsy at a site selected by chest HRCT. In practice, however, lung biopsy is performed on a case-by-case basis. No effective treatment is available to date, and improved understanding of the mechanisms involved in the pathogenesis of pulmonary Langerhans' cell histiocytosis is urgently needed, and should help in the development of specific therapeutic strategies for patients with this orphan disease.

Adult↗
PubMed2004

A new clinical score for disease activity in Langerhans cell histiocytosis.

OBJECTIVE: To develop an objective tool for assessing disease activity in patients with Langerhans cell histiocytosis (LCH). METHOD: Scoring system was developed and applied to a database containing information on 612 patients. RESULTS: At diagnosis, the score distribution was highly asymmetrical: the score was between 0 and 2 in 74% of cases, 3-6 in 16%, 7-10 in 3%, and more than 10 in 6%. The 5-year mortality rates were 1, 4.4, and 43.4%, respectively, among patients with initial scores of 0-2, 3-6, and >6. Stability or an increase of the score at 6 weeks was highly predictive of death among patients with initial scores above 6, while score stability had no significant impact on vital outcome among patients with low or moderate scores at diagnosis. CONCLUSIONS: This LCH disease activity score provides an objective tool for assessing disease severity, both at diagnosis and during follow-up and treatment.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed2004

Prevention of diazepam withdrawal syndrome by nifedipine-behavioural and neurochemical studies.

Our studies aimed at investigating whether the dihydropyridine calcium antagonist, nifedipine, could prevent anxiogenic-like consequences of diazepam withdrawal in rats. Animals withdrawn from chronic diazepam (2 mg/kg/day i.p. for 2 weeks) drank significantly less water than did control rats in the unfamiliar arm of a Y maze. This anxiogenic-like effect could be prevented by acute administration of nifedipine (at 10 mg/kg i.p., but not at lower doses), which, on its own, did not change water intake in naive rats. Given chronically in combination with diazepam for the second half of a 2-week treatment with this drug, nifedipine (at the daily dose of 5 mg/kg i.p.) also suppressed the reduction of water intake normally observed on diazepam withdrawal. Biochemical measurements showed that acutely, as well as chronically, administered nifedipine increased 5-HT turnover in the hippocampus of diazepam-treated rats, thereby suggesting that the prevention of diazepam withdrawal-induced anxiogenic behaviour by the calcium antagonist might be underlain by serotoninergic mechanisms.

Animals↗
PubMed2004

Expression of apoptosis-regulatory proteins in lesions of pulmonary Langerhans cell histiocytosis.

AIMS: Pulmonary Langerhans cell histiocytosis (PLCH) is characterized by the presence of lesions containing numerous activated Langerhans cells (LCs). An uncontrolled immune response sustained by activated LCs seems to be involved in the pathogenesis of the disease. The aim of this study was to establish whether disruption of LC apoptosis related to the expression of the Bcl-2 family proteins is implicated in the maintenance of PLCH lesions. METHODS: Six patients with PLCH were evaluated by morphological and immunohistochemical techniques to explore the incidence of apoptosis in pathological LCs and to characterize the expression of Bcl-2-related proteins by these cells. RESULTS: Very few LCs present in PLCH lesions exhibited nuclear apoptotic changes or expressed cleaved caspase-3, whereas they all strongly expressed the anti-apoptotic molecule Bcl-x(L). Interestingly, pulmonary LCs present in intervening lung tissue not involved by the pathological process and known to be immature dendritic cells did not express Bcl-2 family proteins. CONCLUSIONS: These findings suggest that activated LCs present within PLCH lesions are poorly susceptible to apoptosis and, thus, are able to sustain the pathological process by causing continuous local stimulation of T cells. Functional studies are needed, however, to demonstrate that they are actually resistant to programmed cell death.

Adult↗
PubMed2003

Cytokine profiles in idiopathic pulmonary fibrosis suggest an important role for TGF-beta and IL-10.

Modulation of cytokine expression represents a potentially useful approach for the treatment of idiopathic pulmonary fibrosis (IPF). To identify potential targets for such intervention, semi-quantitative reverse transcriptase-polymerase chain reaction was used to compare the expression of messenger ribonucleic acids (mRNAs) coding for 17 cytokines in lung tissue obtained from patients with IPF at the time of diagnosis and control subjects. Some cytokines were also studied at the protein level by immunohistochemical techniques. mRNAs coding for all of the cytokines evaluated were detected in both control and fibrotic lung samples. Only transforming growth factor (TGF)-beta and interleukin (IL)-10 mRNAs were quantitatively increased in lung biopsies from patients with IPF compared with those of controls, results confirmed at the protein level by immunohistochemistry. Although mRNAs for platelet-derived growth factor (PDGF)-BB and keratinocyte growth factor (KGF) were expressed in similar amounts in lungs from patients with IPF and controls, localised accumulation of both factors was also observed in IPF. Hyperplastic alveolar epithelial cells were a prominent source of cytokines, where IL-10, PDGF-BB and KGF were present in increased amounts, although increased accumulation in fibroblasts, smooth-muscle cells and matrix components was also observed (PDGF-BB, TGF-beta). These results offer new insights into the cytokines produced in the lung in idiopathic pulmonary fibrosis and suggest that modulation of the production of transforming growth factor-beta and interleukin-10 may represent a potentially useful therapeutic strategy for this disabling disease.

Female↗
PubMed2003

[Asthma and pregnancy].

Asthma is the most frequent respiratory disorder complicating pregnancy. Diagnosis and evaluation of severity of asthma are unchanged by the presence of pregnancy, but the course of asthma varies: asthma may improve, remain stable, or worsen. Conversely, chronically poor control is associated with pregnancy-induced hypertension, preeclampsia, as well as greater rates of cesarian section, preterm delivery, intrauterine growth retardation, low birth weight, and congenital malformation. Highly-motivated women with well-controlled asthma during pregnancy, can achieve pregnancy outcome as good as their non-asthmatic conterparts. Inhalation therapies remain the cornerstone of treatment; most appear to be safe in pregnancy.

Algorithms↗
PubMed2002

[Post-partum cerebral thrombophlebitis: three cases].

Post-partum cerebral thrombophlebitis is a rare accident (1/3000 to 1/10000 births). Symptoms vary and may be misleading. We report three cases of cerebral thrombophlebitis occurring during the pospartum period where diagnosis was based on clinical signs and imaging data (computed tomography and cerebral angiography). Heparin therapy led to good outcome in all three cases. Heparin therapy has been controversial for these patients but recent work has shown improvement in this severe conditions with very poor prognosis.

Adult↗
PubMed2001

Computed tomography of pulmonary sarcoid-like granulomas induced by complete Freund's adjuvant in rats.

Intravenous injection of complete Freund's adjuvant (CFA) in rats has been proposed as an experimental model for pulmonary sarcoidosis, but only some animals develop granulomas. Because the detection of the presence of granulomas and evaluation of the extent of the reaction has required histological evaluation, this model has been of limited use in following the evolution of the granulomatous process. The present study evaluated the ability of lung computed tomography (CT) scanning to identify in vivo pulmonary granulomas induced by CFA in rats. Wistar rats were injected with CFA to induce pulmonary sarcoid-like granulomas, and the presence and extent of pulmonary abnormalities, as detected by spiral CT and histopathological analysis, were compared. Spiral CT had a high sensitivity and specificity for the detection of sarcoid-like granulomas in rats injected with CFA. The extent of the pulmonary granulomatous reaction as assessed by the two techniques strongly correlated (r=0.93, p<0.01). In contrast, the mean density of lungs containing granulomas was not significantly different from that of lungs with no granulomatous reaction. Thus, lung computed tomography appears to be a valuable tool for the in vivo evaluation of the pulmonary granulomatous reaction induced by complete Freund's adjuvant in rats. With the help of computed tomography, this experimental model should be suitable for the sequential study of pulmonary sarcoid-like granulomas, particularly in response to various therapeutic strategies.

Adjuvants, Immunologic↗
PubMed2000

Is high-resolution computed tomography a reliable tool to predict the histopathological activity of pulmonary Langerhans cell histiocytosis?

High-resolution computed tomography (HRCT) has proved to be very useful in the diagnosis and follow-up of pulmonary Langerhans cell histiocytosis (PLCH), but the precise relationships between nodules and thin-wall cysts observed by HRCT, and granulomatous or cystic lesions present in lung tissue, remain to be established. The aim of this study was to compare quantitative data obtained by HRCT and those obtained by histopathological examination of corresponding lung tissue specimens in patients with biopsy-proven PLCH. The results demonstrated that the extent of nodular abnormalities was strongly correlated with the density of florid granulomatous lesions in lung tissue. A strong correlation was also found between the extent of cystic abnormalities and the density of cavitary lesions, but the latter included both still inflammatory cavitary granulomas and cicatricial fibrous cysts. Interestingly, small isolated florid granulomas were found in lung tissue from most patients with a predominant cystic CT scan pattern. Taken together, these results demonstrate that HRCT has to be considered with caution to evaluate the histopathological activity of PLCH. Patients presenting with predominant HRCT cystic abnormalities should benefit from a long-term follow-up. Because these patients are susceptible to developing severe respiratory insufficiency, they should also be considered for treatment as soon as an effective therapy for LCH is available.

Adult↗
PubMed2000

111In-pentetreotide scintigraphy in patients with Langerhans' cell histiocytosis.

UNLABELLED: Langerhans' cell histiocytosis is a granulomatous disease that may involve multiple organs and the prognosis of which is highly variable. Because the prognosis depends particularly on the number of tissues involved, the accurate identification of the organs involved by granulomatous lesions is of critical importance. We hypothesized that 111In-pentetreotide scintigraphy would be useful for evaluation of patients with Langerhans' cells histiocytosis. METHODS: Thirteen patients (38.3+/-10.4 y) with Langerhans' cell histiocytosis (8 patients with unifocal lung disease, 5 with multifocal disease) received intravenous 111In-pentetreotide (111-222 MBq), and planar images were obtained at 24 h after injection. Pulmonary uptake was quantified using a lung-to-background ratio (L/B) and compared with a population of 10 normal scintigrams. For the other sites, uptake of radioactivity in disease-related areas was visually assessed. RESULTS: Ten of 12 patients with lung involvement had increased lung uptake (UB, 2.23+/-0.49 versus 1.34+/-0.07; P < 0.001). In the patients with multifocal disease, increased 111In-pentetreotide uptake was found in disease-related areas such as the salivary glands, the skin, the soft tissues, and the bones. However, somatostatin receptor imaging was insensitive for detecting central nervous system and liver involvement and most skin lesions. CONCLUSION: 111In-pentetreotide imaging may be useful in Langerhans' cell histiocytosis. Further study will indicate whether 111In-pentetreotide is a relevant tracer in the management of histiocytosis.

Adult↗
PubMed1999

[T lymphocytes in sarcoidosis].

IMPORTANCE OF T-LYMPHOCYTES IN SARCOIDOSIS: Sarcoidosis is thought to result from an uncontrolled granulomatous immune response. T-lymphocytes are an essential component of this immune reaction. The recognition of specific antigens through receptors expressed on the cell membrane activates the T-cells, resulting in the expression of effector functions that ultimately control granuloma formation. T-cells participating in sarcoid reactions are readily accessible using bronchoalveolar lavage, and have been intensively studied. SPECIFICITY OF T-CELLS: Several groups have evaluated the diversity of T-cell receptors expressed by T-cells from patients with sarcoidosis. These studies have demonstrated that oligoclonal T-cell populations are present both in the lung and blood of these patients, findings that support the conclusion that antigen-induced immune responses play a role in the pathogenesis of sarcoidosis. The identification of the antigen(s) recognized by these cells remains an important goal, and may help identify etiologic agents. CYTOKINE PRODUCTION: Considerable progress has been made in characterizing the cytokines produced by T-lymphocytes and other cells participating in the granulomatous reaction. The modulation of the activity of these mediators represents a promising approach for the development of more specific therapeutic agents.

Adjuvants, Immunologic↗
PubMed1999

Evidence that Langerhans cells in adult pulmonary Langerhans cell histiocytosis are mature dendritic cells: importance of the cytokine microenvironment.

Because Langerhans cells (LC) in peripheral tissues are generally "immature" cells with poor lymphostimulatory activity, the contribution of immune responses initiated by LC to the pathogenesis of pulmonary LC histiocytosis (LCH) has been uncertain. In this study we demonstrate that LC accumulating in LCH granulomas are phenotypically similar to mature lymphostimulatory dendritic cells present in lymphoid organs. LC in LCH granulomas intensely expressed B7-1 and B7-2 molecules, whereas normal pulmonary LC and LC accumulating in other pathologic lung disorders did not express these costimulatory molecules. The presence of B7+ LC in LCH granulomas was associated with the expression in these lesions, but not at other sites in the lung, of a unique profile of cytokines (presence of GM-CSF, TNF-alpha, and IL-1beta and the absence of IL-10) that is known to promote the in vitro differentiation of LC into cells expressing a lymphostimulatory phenotype. Finally, LCH granulomas were the only site where CD154-positive T cells could be identified in close contact with LC intensely expressing CD40 Ags. Taken together, these results strongly support the idea that an abnormal immune response initiated by LC may participate in the pathogenesis of pulmonary LCH, and suggest that therapeutic strategies aimed at modifying the lymphostimulatory phenotype of LC may be useful in the treatment of this disorder.

Adult↗